1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
21 /* Structure for caching DNSBL lookups */
23 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
42 static uschar cutthrough_response(client_conn_ctx *, char, uschar **, int);
46 /*************************************************
47 * Retrieve a callout cache record *
48 *************************************************/
50 /* If a record exists, check whether it has expired.
53 dbm_file an open hints file
55 type "address" or "domain"
56 positive_expire expire time for positive records
57 negative_expire expire time for negative records
59 Returns: the cache record if a non-expired one exists, else NULL
62 static dbdata_callout_cache *
63 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
64 int positive_expire, int negative_expire)
69 dbdata_callout_cache *cache_record;
71 if (!(cache_record = dbfn_read_with_length(dbm_file, key, &length)))
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
85 if (now - cache_record->time_stamp > expire)
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
99 if (length == sizeof(dbdata_callout_cache_obs))
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
120 /* Check the callout cache.
121 Options * pm_mailfrom may be modified by cache partial results.
123 Return: TRUE if result found
127 cached_callout_lookup(address_item * addr, uschar * address_key,
128 uschar * from_address, int * opt_ptr, uschar ** pm_ptr,
129 int * yield, uschar ** failure_ptr,
130 dbdata_callout_cache * new_domain_record, int * old_domain_res)
132 int options = *opt_ptr;
134 open_db *dbm_file = NULL;
136 /* Open the callout cache database, it it exists, for reading only at this
137 stage, unless caching has been disabled. */
139 if (options & vopt_callout_no_cache)
141 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
143 else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)))
145 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
149 /* If a cache database is available see if we can avoid the need to do an
150 actual callout by making use of previously-obtained data. */
152 dbdata_callout_cache_address * cache_address_record;
153 dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file,
154 addr->domain, US"domain",
155 callout_cache_domain_positive_expire, callout_cache_domain_negative_expire);
157 /* If an unexpired cache record was found for this domain, see if the callout
158 process can be short-circuited. */
162 /* In most cases, if an early command (up to and including MAIL FROM:<>)
163 was rejected, there is no point carrying on. The callout fails. However, if
164 we are doing a recipient verification with use_sender or use_postmaster
165 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
166 will be using a non-empty sender. We have to remember this situation so as
167 not to disturb the cached domain value if this whole verification succeeds
168 (we don't want it turning into "accept"). */
170 *old_domain_res = cache_record->result;
172 if ( cache_record->result == ccache_reject
173 || *from_address == 0 && cache_record->result == ccache_reject_mfnull)
175 setflag(addr, af_verify_nsfail);
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)))
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);
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)
376 if (addr->transport == cutthrough.addr.transport)
377 for (host = host_list; host; host = host->next)
378 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
381 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
384 deliver_host = host->name;
385 deliver_host_address = host->address;
386 deliver_host_port = host->port;
387 deliver_domain = addr->domain;
388 transport_name = addr->transport->name;
390 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
392 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
394 || !smtp_get_port(tf->port, addr, &port, US"callout")
396 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
399 smtp_port_for_connect(host, port);
401 if ( ( interface == cutthrough.interface
403 && cutthrough.interface
404 && Ustrcmp(interface, cutthrough.interface) == 0
406 && host->port == cutthrough.host.port
409 uschar * resp = NULL;
411 /* Match! Send the RCPT TO, set done from the response */
413 smtp_write_command(&ctblock, SCMD_FLUSH, "RCPT TO:<%.1000s>\r\n",
414 transport_rcpt_address(addr,
415 addr->transport->rcpt_include_affixes)) >= 0
416 && cutthrough_response(&cutthrough.cctx, '2', &resp,
417 CUTTHROUGH_DATA_TIMEOUT) == '2';
419 /* This would go horribly wrong if a callout fail was ignored by ACL.
420 We punt by abandoning cutthrough on a reject, like the
425 address_item * na = store_get(sizeof(address_item));
426 *na = cutthrough.addr;
427 cutthrough.addr = *addr;
428 cutthrough.addr.host_used = &cutthrough.host;
429 cutthrough.addr.next = na;
435 cancel_cutthrough_connection(TRUE, US"recipient rejected");
436 if (!resp || errno == ETIMEDOUT)
438 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
443 Ustrcpy(resp, US"connection dropped");
446 string_sprintf("response to \"%s\" was: %s",
447 big_buffer, string_printing(resp));
450 string_sprintf("Callout verification failed:\n%s", resp);
452 /* Hard rejection ends the process */
454 if (resp[0] == '5') /* Address rejected */
462 break; /* host_list */
465 cancel_cutthrough_connection(TRUE, US"incompatible connection");
470 /*************************************************
471 * Do callout verification for an address *
472 *************************************************/
474 /* This function is called from verify_address() when the address has routed to
475 a host list, and a callout has been requested. Callouts are expensive; that is
476 why a cache is used to improve the efficiency.
479 addr the address that's been routed
480 host_list the list of hosts to try
481 tf the transport feedback block
483 ifstring "interface" option from transport, or NULL
484 portstring "port" option from transport, or NULL
485 protocolstring "protocol" option from transport, or NULL
486 callout the per-command callout timeout
487 callout_overall the overall callout timeout (if < 0 use 4*callout)
488 callout_connect the callout connection timeout (if < 0 use callout)
489 options the verification options - these bits are used:
490 vopt_is_recipient => this is a recipient address
491 vopt_callout_no_cache => don't use callout cache
492 vopt_callout_fullpm => if postmaster check, do full one
493 vopt_callout_random => do the "random" thing
494 vopt_callout_recipsender => use real sender for recipient
495 vopt_callout_recippmaster => use postmaster for recipient
496 vopt_callout_hold => lazy close connection
497 se_mailfrom MAIL FROM address for sender verify; NULL => ""
498 pm_mailfrom if non-NULL, do the postmaster check with this sender
500 Returns: OK/FAIL/DEFER
504 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
505 int callout, int callout_overall, int callout_connect, int options,
506 uschar *se_mailfrom, uschar *pm_mailfrom)
509 int old_domain_cache_result = ccache_accept;
512 uschar *from_address;
513 uschar *random_local_part = NULL;
514 const uschar *save_deliver_domain = deliver_domain;
515 uschar **failure_ptr = options & vopt_is_recipient
516 ? &recipient_verify_failure : &sender_verify_failure;
517 dbdata_callout_cache new_domain_record;
518 dbdata_callout_cache_address new_address_record;
519 time_t callout_start_time;
521 new_domain_record.result = ccache_unknown;
522 new_domain_record.postmaster_result = ccache_unknown;
523 new_domain_record.random_result = ccache_unknown;
525 memset(&new_address_record, 0, sizeof(new_address_record));
527 /* For a recipient callout, the key used for the address cache record must
528 include the sender address if we are using the real sender in the callout,
529 because that may influence the result of the callout. */
531 if (options & vopt_is_recipient)
532 if (options & vopt_callout_recipsender)
534 from_address = sender_address;
535 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
536 if (cutthrough.delivery) options |= vopt_callout_no_cache;
538 else if (options & vopt_callout_recippmaster)
540 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
541 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
542 qualify_domain_sender);
547 address_key = addr->address;
550 /* For a sender callout, we must adjust the key if the mailfrom address is not
555 from_address = se_mailfrom ? se_mailfrom : US"";
556 address_key = *from_address
557 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
560 if (cached_callout_lookup(addr, address_key, from_address,
561 &options, &pm_mailfrom, &yield, failure_ptr,
562 &new_domain_record, &old_domain_cache_result))
564 cancel_cutthrough_connection(TRUE, US"cache-hit");
568 if (!addr->transport)
570 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
572 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
573 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
574 addr->transport->name, addr->transport->driver_name);
577 smtp_transport_options_block *ob =
578 (smtp_transport_options_block *)addr->transport->options_block;
581 /* The information wasn't available in the cache, so we have to do a real
582 callout and save the result in the cache for next time, unless no_cache is set,
583 or unless we have a previously cached negative random result. If we are to test
584 with a random local part, ensure that such a local part is available. If not,
585 log the fact, but carry on without randomising. */
587 if (options & vopt_callout_random && callout_random_local_part)
588 if (!(random_local_part = expand_string(callout_random_local_part)))
589 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
590 "callout_random_local_part: %s", expand_string_message);
592 /* Default the connect and overall callout timeouts if not set, and record the
593 time we are starting so that we can enforce it. */
595 if (callout_overall < 0) callout_overall = 4 * callout;
596 if (callout_connect < 0) callout_connect = callout;
597 callout_start_time = time(NULL);
599 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
600 output because a callout might take some time. When PIPELINING is active and
601 there are many recipients, the total time for doing lots of callouts can add up
602 and cause the client to time out. So in this case we forgo the PIPELINING
605 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
607 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
608 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
610 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
611 and we are holding a cutthrough conn open, we can just append the rcpt to
612 that conn for verification purposes (and later delivery also). Simplest
613 coding means skipping this whole loop and doing the append separately. */
615 /* Can we re-use an open cutthrough connection? */
616 if ( cutthrough.cctx.sock >= 0
617 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
618 == vopt_callout_recipsender
619 && !random_local_part
622 done = cutthrough_multi(addr, host_list, tf, &yield);
624 /* If we did not use a cached connection, make connections to the hosts
625 and do real callouts. The list of hosts is passed in as an argument. */
627 for (host = host_list; host && !done; host = host->next)
631 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
636 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
641 /* Check the overall callout timeout */
643 if (time(NULL) - callout_start_time >= callout_overall)
645 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
649 /* Set IPv4 or IPv6 */
651 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
653 /* Expand and interpret the interface and port strings. The latter will not
654 be used if there is a host-specific port (e.g. from a manualroute router).
655 This has to be delayed till now, because they may expand differently for
656 different hosts. If there's a failure, log it, but carry on with the
659 deliver_host = host->name;
660 deliver_host_address = host->address;
661 deliver_host_port = host->port;
662 deliver_domain = addr->domain;
663 transport_name = addr->transport->name;
665 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
667 || !smtp_get_port(tf->port, addr, &port, US"callout")
669 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
674 sx.host_af = host_af,
676 sx.interface = interface;
677 sx.helo_data = tf->helo_data;
678 sx.tblock = addr->transport;
681 tls_retry_connection:
682 /* Set the address state so that errors are recorded in it */
684 addr->transport_return = PENDING_DEFER;
685 ob->connect_timeout = callout_connect;
686 ob->command_timeout = callout;
688 /* Get the channel set up ready for a message (MAIL FROM being the next
689 SMTP command to send. If we tried TLS but it failed, try again without
692 yield = smtp_setup_conn(&sx, FALSE);
695 && addr->basic_errno == ERRNO_TLSFAILURE
696 && ob->tls_tempfail_tryclear
697 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
700 log_write(0, LOG_MAIN,
701 "%s: callout unencrypted to %s [%s] (not in hosts_require_tls)",
702 addr->message, host->name, host->address);
703 addr->transport_return = PENDING_DEFER;
704 yield = smtp_setup_conn(&sx, TRUE);
709 errno = addr->basic_errno;
710 transport_name = NULL;
711 deliver_host = deliver_host_address = NULL;
712 deliver_domain = save_deliver_domain;
714 /* Failure to accept HELO is cached; this blocks the whole domain for all
715 senders. I/O errors and defer responses are not cached. */
717 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
719 setflag(addr, af_verify_nsfail);
720 new_domain_record.result = ccache_reject;
728 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
729 the AUTH info for logging */
731 addr->authenticator = client_authenticator;
732 addr->auth_id = client_authenticated_id;
734 sx.from_addr = from_address;
735 sx.first_addr = sx.sync_addr = addr;
736 sx.ok = FALSE; /*XXX these 3 last might not be needed for verify? */
738 sx.completed_addr = FALSE;
740 new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull
741 ? ccache_reject_mfnull : ccache_accept;
743 /* Do the random local part check first. Temporarily replace the recipient
744 with the "random" value */
746 if (random_local_part)
748 uschar * main_address = addr->address;
749 const uschar * rcpt_domain = addr->domain;
752 uschar * errstr = NULL;
753 if ( testflag(addr, af_utf8_downcvt)
754 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
758 addr->message = errstr;
759 errno = ERRNO_EXPANDFAIL;
760 setflag(addr, af_verify_nsfail);
762 rcpt_domain = US""; /*XXX errorhandling! */
766 /* This would be ok for 1st rcpt of a cutthrough (the case handled here;
767 subsequents are done in cutthrough_multi()), but no way to
768 handle a subsequent because of the RSET vaporising the MAIL FROM.
769 So refuse to support any. Most cutthrough use will not involve
770 random_local_part, so no loss. */
771 cancel_cutthrough_connection(TRUE, US"random-recipient");
773 addr->address = string_sprintf("%s@%.1000s",
774 random_local_part, rcpt_domain);
777 /* If accepted, we aren't going to do any further tests below.
778 Otherwise, cache a real negative response, and get back to the right
779 state to send RCPT. Unless there's some problem such as a dropped
780 connection, we expect to succeed, because the commands succeeded above.
781 However, some servers drop the connection after responding to an
782 invalid recipient, so on (any) error we drop and remake the connection.
783 XXX We don't care about that for postmaster_full. Should we?
785 XXX could we add another flag to the context, and have the common
786 code emit the RSET too? Even pipelined after the RCPT...
787 Then the main-verify call could use it if there's to be a subsequent
789 The sync_responses() would need to be taught about it and we'd
790 need another return code filtering out to here.
792 Avoid using a SIZE option on the MAIL for all random-rcpt checks.
795 sx.avoid_option = OPTION_SIZE;
797 /* Remember when we last did a random test */
798 new_domain_record.random_stamp = time(NULL);
800 if (smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0)
801 switch(addr->transport_return)
803 case PENDING_OK: /* random was accepted, unfortunately */
804 new_domain_record.random_result = ccache_accept;
805 yield = OK; /* Only usable verify result we can return */
807 *failure_ptr = US"random";
809 case FAIL: /* rejected: the preferred result */
810 new_domain_record.random_result = ccache_reject;
813 /* Between each check, issue RSET, because some servers accept only
814 one recipient after MAIL FROM:<>.
815 XXX We don't care about that for postmaster_full. Should we? */
818 smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0 &&
819 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
824 debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
825 random_local_part = NULL;
827 tls_close(sx.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
829 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
830 (void)close(sx.cctx.sock);
832 #ifndef DISABLE_EVENT
833 (void) event_raise(addr->transport->event_action,
834 US"tcp:close", NULL);
836 addr->address = main_address;
837 addr->transport_return = PENDING_DEFER;
838 sx.first_addr = sx.sync_addr = addr;
841 sx.completed_addr = FALSE;
842 goto tls_retry_connection;
843 case DEFER: /* 4xx response to random */
844 break; /* Just to be clear. ccache_unknown, !done. */
847 /* Re-setup for main verify, or for the error message when failing */
848 addr->address = main_address;
849 addr->transport_return = PENDING_DEFER;
850 sx.first_addr = sx.sync_addr = addr;
853 sx.completed_addr = FALSE;
858 /* Main verify. For rcpt-verify use SIZE if we know it and we're not cacheing;
859 for sndr-verify never use it. */
863 if (!(options & vopt_is_recipient && options & vopt_callout_no_cache))
864 sx.avoid_option = OPTION_SIZE;
867 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
869 case 0: switch(addr->transport_return) /* ok so far */
871 case PENDING_OK: done = TRUE;
872 new_address_record.result = ccache_accept;
874 case FAIL: done = TRUE;
876 *failure_ptr = US"recipient";
877 new_address_record.result = ccache_reject;
883 case -1: /* MAIL response error */
884 *failure_ptr = US"mail";
885 if (errno == 0 && sx.buffer[0] == '5')
887 setflag(addr, af_verify_nsfail);
888 if (from_address[0] == 0)
889 new_domain_record.result = ccache_reject_mfnull;
892 /* non-MAIL read i/o error */
893 /* non-MAIL response timeout */
894 /* internal error; channel still usable */
895 default: break; /* transmit failed */
899 addr->auth_sndr = client_authenticated_sender;
901 deliver_host = deliver_host_address = NULL;
902 deliver_domain = save_deliver_domain;
904 /* Do postmaster check if requested; if a full check is required, we
905 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
907 if (done && pm_mailfrom)
909 /* Could possibly shift before main verify, just above, and be ok
910 for cutthrough. But no way to handle a subsequent rcpt, so just
912 cancel_cutthrough_connection(TRUE, US"postmaster verify");
913 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
915 done = smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0
916 && smtp_read_response(&sx.inblock, sx.buffer,
917 sizeof(sx.buffer), '2', callout);
921 uschar * main_address = addr->address;
923 /*XXX oops, affixes */
924 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
925 addr->transport_return = PENDING_DEFER;
927 sx.from_addr = pm_mailfrom;
928 sx.first_addr = sx.sync_addr = addr;
931 sx.completed_addr = FALSE;
932 sx.avoid_option = OPTION_SIZE;
934 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
935 && addr->transport_return == PENDING_OK
939 done = (options & vopt_callout_fullpm) != 0
940 && smtp_write_command(&sx.outblock, SCMD_FLUSH,
941 "RCPT TO:<postmaster>\r\n") >= 0
942 && smtp_read_response(&sx.inblock, sx.buffer,
943 sizeof(sx.buffer), '2', callout);
945 /* Sort out the cache record */
947 new_domain_record.postmaster_stamp = time(NULL);
950 new_domain_record.postmaster_result = ccache_accept;
951 else if (errno == 0 && sx.buffer[0] == '5')
953 *failure_ptr = US"postmaster";
954 setflag(addr, af_verify_pmfail);
955 new_domain_record.postmaster_result = ccache_reject;
958 addr->address = main_address;
961 /* For any failure of the main check, other than a negative response, we just
962 close the connection and carry on. We can identify a negative response by the
963 fact that errno is zero. For I/O errors it will be non-zero
965 Set up different error texts for logging and for sending back to the caller
966 as an SMTP response. Log in all cases, using a one-line format. For sender
967 callouts, give a full response to the caller, but for recipient callouts,
968 don't give the IP address because this may be an internal host whose identity
969 is not to be widely broadcast. */
975 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
976 sx.send_quit = FALSE;
982 extern int acl_where; /* src/acl.c */
984 addr->message = string_sprintf(
985 "response to \"EHLO\" did not include SMTPUTF8");
986 addr->user_message = acl_where == ACL_WHERE_RCPT
987 ? US"533 no support for internationalised mailbox name"
988 : US"550 mailbox unavailable";
995 sx.send_quit = FALSE;
999 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
1001 /*XXX test here is ugly; seem to have a split of responsibility for
1002 building this message. Need to rationalise. Where is it done
1003 before here, and when not?
1004 Not == 5xx resp to MAIL on main-verify
1006 if (!addr->message) addr->message =
1007 string_sprintf("response to \"%s\" was: %s",
1008 big_buffer, string_printing(sx.buffer));
1010 addr->user_message = options & vopt_is_recipient
1011 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
1012 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1013 host->address, big_buffer, sx.buffer);
1015 /* Hard rejection ends the process */
1017 if (sx.buffer[0] == '5') /* Address rejected */
1025 /* End the SMTP conversation and close the connection. */
1027 /* Cutthrough - on a successful connect and recipient-verify with
1028 use-sender and we are 1st rcpt and have no cutthrough conn so far
1029 here is where we want to leave the conn open. Ditto for a lazy-close
1032 if (cutthrough.delivery)
1034 if (addr->transport->filter_command)
1036 cutthrough.delivery= FALSE;
1037 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
1039 #ifndef DISABLE_DKIM
1040 if (ob->dkim.dkim_domain)
1042 cutthrough.delivery= FALSE;
1043 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
1046 #ifdef EXPERIMENTAL_ARC
1049 cutthrough.delivery= FALSE;
1050 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of ARC signing\n");
1055 if ( (cutthrough.delivery || options & vopt_callout_hold)
1059 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1060 == vopt_callout_recipsender
1061 && !random_local_part
1063 && cutthrough.cctx.sock < 0
1067 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for %s\n",
1069 ? "cutthrough delivery" : "potential further verifies and delivery");
1071 cutthrough.callout_hold_only = !cutthrough.delivery;
1072 cutthrough.is_tls = tls_out.active.sock >= 0;
1073 /* We assume no buffer in use in the outblock */
1074 cutthrough.cctx = sx.cctx;
1075 cutthrough.nrcpt = 1;
1076 cutthrough.transport = addr->transport->name;
1077 cutthrough.interface = interface;
1078 cutthrough.snd_port = sending_port;
1079 cutthrough.peer_options = smtp_peer_options;
1080 cutthrough.host = *host;
1082 int oldpool = store_pool;
1083 store_pool = POOL_PERM;
1084 cutthrough.snd_ip = string_copy(sending_ip_address);
1085 cutthrough.host.name = string_copy(host->name);
1086 cutthrough.host.address = string_copy(host->address);
1087 store_pool = oldpool;
1089 cutthrough.addr = *addr; /* Save the address_item for later logging */
1090 cutthrough.addr.next = NULL;
1091 cutthrough.addr.host_used = &cutthrough.host;
1093 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1095 ctblock.buffer = ctbuffer;
1096 ctblock.buffersize = sizeof(ctbuffer);
1097 ctblock.ptr = ctbuffer;
1098 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1099 ctblock.cctx = &cutthrough.cctx;
1103 /* Ensure no cutthrough on multiple verifies that were incompatible */
1104 if (options & vopt_callout_recipsender)
1105 cancel_cutthrough_connection(TRUE, US"not usable for cutthrough");
1108 (void) smtp_write_command(&sx.outblock, SCMD_FLUSH, "QUIT\r\n");
1110 /* Wait a short time for response, and discard it */
1111 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1115 if (sx.cctx.sock >= 0)
1118 if (sx.cctx.tls_ctx)
1120 tls_close(sx.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
1121 sx.cctx.tls_ctx = NULL;
1124 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1125 (void)close(sx.cctx.sock);
1127 #ifndef DISABLE_EVENT
1128 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1133 if (!done || yield != OK)
1134 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1136 } /* Loop through all hosts, while !done */
1139 /* If we get here with done == TRUE, a successful callout happened, and yield
1140 will be set OK or FAIL according to the response to the RCPT command.
1141 Otherwise, we looped through the hosts but couldn't complete the business.
1142 However, there may be domain-specific information to cache in both cases. */
1144 if (!(options & vopt_callout_no_cache))
1145 cache_callout_write(&new_domain_record, addr->domain,
1146 done, &new_address_record, address_key);
1148 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1149 temporary error. If there was only one host, and a response was received, leave
1150 it alone if supplying details. Otherwise, give a generic response. */
1154 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1155 options & vopt_is_recipient ? "recipient" : "sender");
1158 addr->message = host_list->next || !addr->message
1159 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1161 addr->user_message = smtp_return_error_details
1162 ? string_sprintf("%s for <%s>.\n"
1163 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1164 "they may be permanently unreachable from this server. In the latter case,\n%s",
1165 dullmsg, addr->address,
1166 options & vopt_is_recipient
1167 ? "the address will never be accepted."
1168 : "you need to change the address or create an MX record for its domain\n"
1169 "if it is supposed to be generally accessible from the Internet.\n"
1170 "Talk to your mail administrator for details.")
1173 /* Force a specific error code */
1175 addr->basic_errno = ERRNO_CALLOUTDEFER;
1178 /* Come here from within the cache-reading code on fast-track exit. */
1181 tls_modify_variables(&tls_in);
1187 /* Called after recipient-acl to get a cutthrough connection open when
1188 one was requested and a recipient-verify wasn't subsequently done.
1191 open_cutthrough_connection( address_item * addr )
1196 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1197 /* We must use a copy of the address for verification, because it might
1201 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1202 rcpt_count > 1 ? "more" : "start");
1203 rc = verify_address(&addr2, NULL,
1204 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1205 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1207 addr->message = addr2.message;
1208 addr->user_message = addr2.user_message;
1209 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1215 /* Send given number of bytes from the buffer */
1217 cutthrough_send(int n)
1219 if(cutthrough.cctx.sock < 0)
1225 ? tls_write(cutthrough.cctx.tls_ctx, ctblock.buffer, n, FALSE)
1228 send(cutthrough.cctx.sock, ctblock.buffer, n, 0) > 0
1231 transport_count += n;
1232 ctblock.ptr= ctblock.buffer;
1236 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1243 _cutthrough_puts(uschar * cp, int n)
1247 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1248 if(!cutthrough_send(ctblock.buffersize))
1251 *ctblock.ptr++ = *cp++;
1256 /* Buffered output of counted data block. Return boolean success */
1258 cutthrough_puts(uschar * cp, int n)
1260 if (cutthrough.cctx.sock < 0) return TRUE;
1261 if (_cutthrough_puts(cp, n)) return TRUE;
1262 cancel_cutthrough_connection(TRUE, US"transmit failed");
1267 cutthrough_data_puts(uschar * cp, int n)
1269 if (cutthrough.delivery) (void) cutthrough_puts(cp, n);
1275 _cutthrough_flush_send(void)
1277 int n = ctblock.ptr - ctblock.buffer;
1280 if(!cutthrough_send(n))
1286 /* Send out any bufferred output. Return boolean success. */
1288 cutthrough_flush_send(void)
1290 if (_cutthrough_flush_send()) return TRUE;
1291 cancel_cutthrough_connection(TRUE, US"transmit failed");
1297 cutthrough_put_nl(void)
1299 return cutthrough_puts(US"\r\n", 2);
1304 cutthrough_data_put_nl(void)
1306 cutthrough_data_puts(US"\r\n", 2);
1310 /* Get and check response from cutthrough target */
1312 cutthrough_response(client_conn_ctx * cctx, char expect, uschar ** copy, int timeout)
1314 smtp_inblock inblock;
1315 uschar inbuffer[4096];
1316 uschar responsebuffer[4096];
1318 inblock.buffer = inbuffer;
1319 inblock.buffersize = sizeof(inbuffer);
1320 inblock.ptr = inbuffer;
1321 inblock.ptrend = inbuffer;
1322 inblock.cctx = cctx;
1323 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1324 cancel_cutthrough_connection(TRUE, US"target timeout on read");
1329 *copy = cp = string_copy(responsebuffer);
1330 /* Trim the trailing end of line */
1331 cp += Ustrlen(responsebuffer);
1332 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1333 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1336 return responsebuffer[0];
1340 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1342 cutthrough_predata(void)
1344 if(cutthrough.cctx.sock < 0 || cutthrough.callout_hold_only)
1347 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1348 cutthrough_puts(US"DATA\r\n", 6);
1349 cutthrough_flush_send();
1351 /* Assume nothing buffered. If it was it gets ignored. */
1352 return cutthrough_response(&cutthrough.cctx, '3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1356 /* tctx arg only to match write_chunk() */
1358 cutthrough_write_chunk(transport_ctx * tctx, uschar * s, int len)
1361 while(s && (s2 = Ustrchr(s, '\n')))
1363 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1371 /* Buffered send of headers. Return success boolean. */
1372 /* Expands newlines to wire format (CR,NL). */
1373 /* Also sends header-terminating blank line. */
1375 cutthrough_headers_send(void)
1379 if(cutthrough.cctx.sock < 0 || cutthrough.callout_hold_only)
1382 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1383 but having a separate buffered-output function (for now)
1385 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1387 tctx.u.fd = cutthrough.cctx.sock;
1388 tctx.tblock = cutthrough.addr.transport;
1389 tctx.addr = &cutthrough.addr;
1390 tctx.check_string = US".";
1391 tctx.escape_string = US"..";
1392 /*XXX check under spool_files_wireformat. Might be irrelevant */
1393 tctx.options = topt_use_crlf;
1395 if (!transport_headers_send(&tctx, &cutthrough_write_chunk))
1398 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1404 close_cutthrough_connection(const uschar * why)
1406 int fd = cutthrough.cctx.sock;
1409 /* We could be sending this after a bunch of data, but that is ok as
1410 the only way to cancel the transfer in dataphase is to drop the tcp
1411 conn before the final dot.
1413 client_conn_ctx tmp_ctx = cutthrough.cctx;
1414 ctblock.ptr = ctbuffer;
1415 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1416 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1417 _cutthrough_flush_send();
1418 cutthrough.cctx.sock = -1; /* avoid recursion via read timeout */
1419 cutthrough.nrcpt = 0; /* permit re-cutthrough on subsequent message */
1421 /* Wait a short time for response, and discard it */
1422 cutthrough_response(&tmp_ctx, '2', NULL, 1);
1425 if (cutthrough.is_tls)
1427 tls_close(cutthrough.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
1428 cutthrough.cctx.tls_ctx = NULL;
1429 cutthrough.is_tls = FALSE;
1432 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1434 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1436 ctblock.ptr = ctbuffer;
1440 cancel_cutthrough_connection(BOOL close_noncutthrough_verifies, const uschar * why)
1442 if (cutthrough.delivery || close_noncutthrough_verifies)
1443 close_cutthrough_connection(why);
1444 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1449 release_cutthrough_connection(const uschar * why)
1451 if (cutthrough.cctx.sock < 0) return;
1452 HDEBUG(D_acl) debug_printf_indent("release cutthrough conn: %s\n", why);
1453 cutthrough.cctx.sock = -1;
1454 cutthrough.cctx.tls_ctx = NULL;
1455 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1461 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1462 Log an OK response as a transmission.
1463 Close the connection.
1464 Return smtp response-class digit.
1467 cutthrough_finaldot(void)
1470 address_item * addr;
1471 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1473 /* Assume data finshed with new-line */
1474 if( !cutthrough_puts(US".", 1)
1475 || !cutthrough_put_nl()
1476 || !cutthrough_flush_send()
1478 return cutthrough.addr.message;
1480 res = cutthrough_response(&cutthrough.cctx, '2', &cutthrough.addr.message,
1481 CUTTHROUGH_DATA_TIMEOUT);
1482 for (addr = &cutthrough.addr; addr; addr = addr->next)
1484 addr->message = cutthrough.addr.message;
1488 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1489 close_cutthrough_connection(US"delivered");
1493 delivery_log(LOG_MAIN, addr, 0,
1494 US"tmp-reject from cutthrough after DATA:");
1498 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1499 US"rejected after DATA:");
1506 return cutthrough.addr.message;
1511 /*************************************************
1512 * Copy error to toplevel address *
1513 *************************************************/
1515 /* This function is used when a verify fails or defers, to ensure that the
1516 failure or defer information is in the original toplevel address. This applies
1517 when an address is redirected to a single new address, and the failure or
1518 deferral happens to the child address.
1521 vaddr the verify address item
1522 addr the final address item
1525 Returns: the value of YIELD
1529 copy_error(address_item *vaddr, address_item *addr, int yield)
1533 vaddr->message = addr->message;
1534 vaddr->user_message = addr->user_message;
1535 vaddr->basic_errno = addr->basic_errno;
1536 vaddr->more_errno = addr->more_errno;
1537 vaddr->prop.address_data = addr->prop.address_data;
1538 copyflag(vaddr, addr, af_pass_message);
1546 /**************************************************
1547 * printf that automatically handles TLS if needed *
1548 ***************************************************/
1550 /* This function is used by verify_address() as a substitute for all fprintf()
1551 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1552 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1553 that assumes that we always use the smtp_out FILE* when not using TLS or the
1554 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1555 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1559 f the candidate FILE* to write to
1560 format format string
1561 ... optional arguments
1567 static void PRINTF_FUNCTION(2,3)
1568 respond_printf(FILE *f, const char *format, ...)
1572 va_start(ap, format);
1573 if (smtp_out && (f == smtp_out))
1574 smtp_vprintf(format, FALSE, ap);
1576 vfprintf(f, format, ap);
1582 /*************************************************
1583 * Verify an email address *
1584 *************************************************/
1586 /* This function is used both for verification (-bv and at other times) and
1587 address testing (-bt), which is indicated by address_test_mode being set.
1590 vaddr contains the address to verify; the next field in this block
1592 f if not NULL, write the result to this file
1593 options various option bits:
1594 vopt_fake_sender => this sender verify is not for the real
1595 sender (it was verify=sender=xxxx or an address from a
1596 header line) - rewriting must not change sender_address
1597 vopt_is_recipient => this is a recipient address, otherwise
1598 it's a sender address - this affects qualification and
1599 rewriting and messages from callouts
1600 vopt_qualify => qualify an unqualified address; else error
1601 vopt_expn => called from SMTP EXPN command
1602 vopt_success_on_redirect => when a new address is generated
1603 the verification instantly succeeds
1605 These ones are used by do_callout() -- the options variable
1608 vopt_callout_fullpm => if postmaster check, do full one
1609 vopt_callout_no_cache => don't use callout cache
1610 vopt_callout_random => do the "random" thing
1611 vopt_callout_recipsender => use real sender for recipient
1612 vopt_callout_recippmaster => use postmaster for recipient
1614 callout if > 0, specifies that callout is required, and gives timeout
1615 for individual commands
1616 callout_overall if > 0, gives overall timeout for the callout function;
1617 if < 0, a default is used (see do_callout())
1618 callout_connect the connection timeout for callouts
1619 se_mailfrom when callout is requested to verify a sender, use this
1620 in MAIL FROM; NULL => ""
1621 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1622 thing and use this as the sender address (may be "")
1624 routed if not NULL, set TRUE if routing succeeded, so we can
1625 distinguish between routing failed and callout failed
1627 Returns: OK address verified
1628 FAIL address failed to verify
1629 DEFER can't tell at present
1633 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1634 int callout_overall, int callout_connect, uschar *se_mailfrom,
1635 uschar *pm_mailfrom, BOOL *routed)
1638 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1639 BOOL expn = (options & vopt_expn) != 0;
1640 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1643 int verify_type = expn? v_expn :
1644 address_test_mode? v_none :
1645 options & vopt_is_recipient? v_recipient : v_sender;
1646 address_item *addr_list;
1647 address_item *addr_new = NULL;
1648 address_item *addr_remote = NULL;
1649 address_item *addr_local = NULL;
1650 address_item *addr_succeed = NULL;
1651 uschar **failure_ptr = options & vopt_is_recipient
1652 ? &recipient_verify_failure : &sender_verify_failure;
1653 uschar *ko_prefix, *cr;
1654 uschar *address = vaddr->address;
1655 uschar *save_sender;
1656 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1658 /* Clear, just in case */
1660 *failure_ptr = NULL;
1662 /* Set up a prefix and suffix for error message which allow us to use the same
1663 output statements both in EXPN mode (where an SMTP response is needed) and when
1664 debugging with an output file. */
1668 ko_prefix = US"553 ";
1671 else ko_prefix = cr = US"";
1673 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1675 if (parse_find_at(address) == NULL)
1677 if (!(options & vopt_qualify))
1680 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1681 ko_prefix, address, cr);
1682 *failure_ptr = US"qualify";
1685 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1690 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1691 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1694 /* Rewrite and report on it. Clear the domain and local part caches - these
1695 may have been set by domains and local part tests during an ACL. */
1697 if (global_rewrite_rules)
1699 uschar *old = address;
1700 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1701 global_rewrite_rules, rewrite_existflags);
1704 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1705 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1706 if (f && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1710 /* If this is the real sender address, we must update sender_address at
1711 this point, because it may be referred to in the routers. */
1713 if (!(options & (vopt_fake_sender|vopt_is_recipient)))
1714 sender_address = address;
1716 /* If the address was rewritten to <> no verification can be done, and we have
1717 to return OK. This rewriting is permitted only for sender addresses; for other
1718 addresses, such rewriting fails. */
1720 if (!address[0]) return OK;
1722 /* Flip the legacy TLS-related variables over to the outbound set in case
1723 they're used in the context of a transport used by verification. Reset them
1724 at exit from this routine (so no returns allowed from here on). */
1726 tls_modify_variables(&tls_out);
1728 /* Save a copy of the sender address for re-instating if we change it to <>
1729 while verifying a sender address (a nice bit of self-reference there). */
1731 save_sender = sender_address;
1733 /* Observability variable for router/transport use */
1735 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1737 /* Update the address structure with the possibly qualified and rewritten
1738 address. Set it up as the starting address on the chain of new addresses. */
1740 vaddr->address = address;
1743 /* We need a loop, because an address can generate new addresses. We must also
1744 cope with generated pipes and files at the top level. (See also the code and
1745 comment in deliver.c.) However, it is usually the case that the router for
1746 user's .forward files has its verify flag turned off.
1748 If an address generates more than one child, the loop is used only when
1749 full_info is set, and this can only be set locally. Remote enquiries just get
1750 information about the top level address, not anything that it generated. */
1755 address_item *addr = addr_new;
1757 addr_new = addr->next;
1762 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1763 debug_printf("Considering %s\n", addr->address);
1766 /* Handle generated pipe, file or reply addresses. We don't get these
1767 when handling EXPN, as it does only one level of expansion. */
1769 if (testflag(addr, af_pfr))
1776 if (addr->address[0] == '>')
1778 allow = testflag(addr, af_allow_reply);
1779 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1783 allow = addr->address[0] == '|'
1784 ? testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1785 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1788 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1789 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1790 "%s\n", addr->message);
1792 fprintf(f, "\n transport = %s\n", addr->transport->name);
1794 fprintf(f, " *** forbidden ***\n");
1799 /* Just in case some router parameter refers to it. */
1801 return_path = addr->prop.errors_address
1802 ? addr->prop.errors_address : sender_address;
1804 /* Split the address into domain and local part, handling the %-hack if
1805 necessary, and then route it. While routing a sender address, set
1806 $sender_address to <> because that is what it will be if we were trying to
1807 send a bounce to the sender. */
1809 if (routed) *routed = FALSE;
1810 if ((rc = deliver_split_address(addr)) == OK)
1812 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1813 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1814 &addr_succeed, verify_type);
1815 sender_address = save_sender; /* Put back the real sender */
1818 /* If routing an address succeeded, set the flag that remembers, for use when
1819 an ACL cached a sender verify (in case a callout fails). Then if routing set
1820 up a list of hosts or the transport has a host list, and the callout option
1821 is set, and we aren't in a host checking run, do the callout verification,
1822 and set another flag that notes that a callout happened. */
1826 if (routed) *routed = TRUE;
1829 transport_instance * tp;
1830 host_item * host_list = addr->host_list;
1832 /* Make up some data for use in the case where there is no remote
1835 transport_feedback tf = {
1836 .interface = NULL, /* interface (=> any) */
1838 .protocol = US"smtp",
1840 .helo_data = US"$smtp_active_hostname",
1841 .hosts_override = FALSE,
1842 .hosts_randomize = FALSE,
1843 .gethostbyname = FALSE,
1844 .qualify_single = TRUE,
1845 .search_parents = FALSE
1848 /* If verification yielded a remote transport, we want to use that
1849 transport's options, so as to mimic what would happen if we were really
1850 sending a message to this address. */
1852 if ((tp = addr->transport) && !tp->info->local)
1854 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1856 /* If the transport has hosts and the router does not, or if the
1857 transport is configured to override the router's hosts, we must build a
1858 host list of the transport's hosts, and find the IP addresses */
1860 if (tf.hosts && (!host_list || tf.hosts_override))
1863 const uschar *save_deliver_domain = deliver_domain;
1864 uschar *save_deliver_localpart = deliver_localpart;
1866 host_list = NULL; /* Ignore the router's hosts */
1868 deliver_domain = addr->domain;
1869 deliver_localpart = addr->local_part;
1870 s = expand_string(tf.hosts);
1871 deliver_domain = save_deliver_domain;
1872 deliver_localpart = save_deliver_localpart;
1876 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1877 "\"%s\" in %s transport for callout: %s", tf.hosts,
1878 tp->name, expand_string_message);
1883 host_item *host, *nexthost;
1884 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1886 /* Just ignore failures to find a host address. If we don't manage
1887 to find any addresses, the callout will defer. Note that more than
1888 one address may be found for a single host, which will result in
1889 additional host items being inserted into the chain. Hence we must
1890 save the next host first. */
1892 flags = HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
1893 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1894 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1896 for (host = host_list; host; host = nexthost)
1898 nexthost = host->next;
1899 if (tf.gethostbyname ||
1900 string_is_ip_address(host->name, NULL) != 0)
1901 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1904 dnssec_domains * dnssec_domains = NULL;
1905 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1907 smtp_transport_options_block * ob =
1908 (smtp_transport_options_block *) tp->options_block;
1909 dnssec_domains = &ob->dnssec;
1912 (void) host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1913 dnssec_domains, NULL, NULL);
1920 /* Can only do a callout if we have at least one host! If the callout
1921 fails, it will have set ${sender,recipient}_verify_failure. */
1925 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1926 if (host_checking && !host_checking_callout)
1929 debug_printf("... callout omitted by default when host testing\n"
1930 "(Use -bhc if you want the callouts to happen.)\n");
1935 deliver_set_expansions(addr);
1937 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1938 callout_connect, options, se_mailfrom, pm_mailfrom);
1943 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1944 "transport provided a host list, or transport is not smtp\n");
1949 /* Otherwise, any failure is a routing failure */
1951 else *failure_ptr = US"route";
1953 /* A router may return REROUTED if it has set up a child address as a result
1954 of a change of domain name (typically from widening). In this case we always
1955 want to continue to verify the new child. */
1957 if (rc == REROUTED) continue;
1959 /* Handle hard failures */
1966 address_item *p = addr->parent;
1968 respond_printf(f, "%s%s %s", ko_prefix,
1969 full_info ? addr->address : address,
1970 address_test_mode ? "is undeliverable" : "failed to verify");
1971 if (!expn && admin_user)
1973 if (addr->basic_errno > 0)
1974 respond_printf(f, ": %s", strerror(addr->basic_errno));
1976 respond_printf(f, ": %s", addr->message);
1979 /* Show parents iff doing full info */
1981 if (full_info) while (p)
1983 respond_printf(f, "%s\n <-- %s", cr, p->address);
1986 respond_printf(f, "%s\n", cr);
1988 cancel_cutthrough_connection(TRUE, US"routing hard fail");
1992 yield = copy_error(vaddr, addr, FAIL);
2000 else if (rc == DEFER)
2005 address_item *p = addr->parent;
2006 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
2007 full_info? addr->address : address);
2008 if (!expn && admin_user)
2010 if (addr->basic_errno > 0)
2011 respond_printf(f, ": %s", strerror(addr->basic_errno));
2013 respond_printf(f, ": %s", addr->message);
2014 else if (addr->basic_errno <= 0)
2015 respond_printf(f, ": unknown error");
2018 /* Show parents iff doing full info */
2020 if (full_info) while (p)
2022 respond_printf(f, "%s\n <-- %s", cr, p->address);
2025 respond_printf(f, "%s\n", cr);
2027 cancel_cutthrough_connection(TRUE, US"routing soft fail");
2031 yield = copy_error(vaddr, addr, DEFER);
2034 if (yield == OK) yield = DEFER;
2037 /* If we are handling EXPN, we do not want to continue to route beyond
2038 the top level (whose address is in "address"). */
2042 uschar *ok_prefix = US"250-";
2045 if (!addr_local && !addr_remote)
2046 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2048 respond_printf(f, "250 <%s>\r\n", address);
2052 address_item *addr2 = addr_new;
2053 addr_new = addr2->next;
2054 if (!addr_new) ok_prefix = US"250 ";
2055 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2061 /* Successful routing other than EXPN. */
2065 /* Handle successful routing when short info wanted. Otherwise continue for
2066 other (generated) addresses. Short info is the operational case. Full info
2067 can be requested only when debug_selector != 0 and a file is supplied.
2069 There is a conflict between the use of aliasing as an alternate email
2070 address, and as a sort of mailing list. If an alias turns the incoming
2071 address into just one address (e.g. J.Caesar->jc44) you may well want to
2072 carry on verifying the generated address to ensure it is valid when
2073 checking incoming mail. If aliasing generates multiple addresses, you
2074 probably don't want to do this. Exim therefore treats the generation of
2075 just a single new address as a special case, and continues on to verify the
2076 generated address. */
2078 if ( !full_info /* Stop if short info wanted AND */
2079 && ( ( !addr_new /* No new address OR */
2080 || addr_new->next /* More than one new address OR */
2081 || testflag(addr_new, af_pfr) /* New address is pfr */
2084 ( addr_new /* At least one new address AND */
2085 && success_on_redirect /* success_on_redirect is set */
2089 if (f) fprintf(f, "%s %s\n",
2090 address, address_test_mode ? "is deliverable" : "verified");
2092 /* If we have carried on to verify a child address, we want the value
2093 of $address_data to be that of the child */
2095 vaddr->prop.address_data = addr->prop.address_data;
2097 /* If stopped because more than one new address, cannot cutthrough */
2099 if (addr_new && addr_new->next)
2100 cancel_cutthrough_connection(TRUE, US"multiple addresses from routing");
2106 } /* Loop for generated addresses */
2108 /* Display the full results of the successful routing, including any generated
2109 addresses. Control gets here only when full_info is set, which requires f not
2110 to be NULL, and this occurs only when a top-level verify is called with the
2111 debugging switch on.
2113 If there are no local and no remote addresses, and there were no pipes, files,
2114 or autoreplies, and there were no errors or deferments, the message is to be
2115 discarded, usually because of the use of :blackhole: in an alias file. */
2117 if (allok && !addr_local && !addr_remote)
2119 fprintf(f, "mail to %s is discarded\n", address);
2123 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2126 address_item *addr = addr_list;
2127 address_item *p = addr->parent;
2128 transport_instance * tp = addr->transport;
2130 addr_list = addr->next;
2132 fprintf(f, "%s", CS addr->address);
2133 #ifdef EXPERIMENTAL_SRS
2134 if(addr->prop.srs_sender)
2135 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2138 /* If the address is a duplicate, show something about it. */
2140 if (!testflag(addr, af_pfr))
2143 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2144 fprintf(f, " [duplicate, would not be delivered]");
2145 else tree_add_duplicate(addr->unique, addr);
2148 /* Now show its parents */
2150 for (p = addr->parent; p; p = p->parent)
2151 fprintf(f, "\n <-- %s", p->address);
2154 /* Show router, and transport */
2156 fprintf(f, "router = %s, transport = %s\n",
2157 addr->router->name, tp ? tp->name : US"unset");
2159 /* Show any hosts that are set up by a router unless the transport
2160 is going to override them; fiddle a bit to get a nice format. */
2162 if (addr->host_list && tp && !tp->overrides_hosts)
2167 for (h = addr->host_list; h; h = h->next)
2168 { /* get max lengths of host names, addrs */
2169 int len = Ustrlen(h->name);
2170 if (len > maxlen) maxlen = len;
2171 len = h->address ? Ustrlen(h->address) : 7;
2172 if (len > maxaddlen) maxaddlen = len;
2174 for (h = addr->host_list; h; h = h->next)
2176 fprintf(f, " host %-*s ", maxlen, h->name);
2179 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2180 else if (tp->info->local)
2181 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2183 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2185 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2186 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2187 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2188 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2194 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2195 the -bv or -bt case). */
2199 tls_modify_variables(&tls_in);
2207 /*************************************************
2208 * Check headers for syntax errors *
2209 *************************************************/
2211 /* This function checks those header lines that contain addresses, and verifies
2212 that all the addresses therein are 5322-syntactially correct.
2215 msgptr where to put an error message
2222 verify_check_headers(uschar **msgptr)
2228 for (h = header_list; h && yield == OK; h = h->next)
2230 if (h->type != htype_from &&
2231 h->type != htype_reply_to &&
2232 h->type != htype_sender &&
2233 h->type != htype_to &&
2234 h->type != htype_cc &&
2235 h->type != htype_bcc)
2238 colon = Ustrchr(h->text, ':');
2240 while (isspace(*s)) s++;
2242 /* Loop for multiple addresses in the header, enabling group syntax. Note
2243 that we have to reset this after the header has been scanned. */
2245 parse_allow_group = TRUE;
2249 uschar *ss = parse_find_address_end(s, FALSE);
2250 uschar *recipient, *errmess;
2251 int terminator = *ss;
2252 int start, end, domain;
2254 /* Temporarily terminate the string at this point, and extract the
2255 operative address within, allowing group syntax. */
2258 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2261 /* Permit an unqualified address only if the message is local, or if the
2262 sending host is configured to be permitted to send them. */
2264 if (recipient && !domain)
2266 if (h->type == htype_from || h->type == htype_sender)
2268 if (!allow_unqualified_sender) recipient = NULL;
2272 if (!allow_unqualified_recipient) recipient = NULL;
2274 if (recipient == NULL) errmess = US"unqualified address not permitted";
2277 /* It's an error if no address could be extracted, except for the special
2278 case of an empty address. */
2280 if (!recipient && Ustrcmp(errmess, "empty address") != 0)
2282 uschar *verb = US"is";
2287 /* Arrange not to include any white space at the end in the
2288 error message or the header name. */
2290 while (t > s && isspace(t[-1])) t--;
2291 while (tt > h->text && isspace(tt[-1])) tt--;
2293 /* Add the address that failed to the error message, since in a
2294 header with very many addresses it is sometimes hard to spot
2295 which one is at fault. However, limit the amount of address to
2296 quote - cases have been seen where, for example, a missing double
2297 quote in a humungous To: header creates an "address" that is longer
2298 than string_sprintf can handle. */
2307 /* deconst cast ok as we're passing a non-const to string_printing() */
2308 *msgptr = US string_printing(
2309 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2310 errmess, (int)(tt - h->text), h->text, verb, len, s));
2313 break; /* Out of address loop */
2316 /* Advance to the next address */
2318 s = ss + (terminator ? 1 : 0);
2319 while (isspace(*s)) s++;
2320 } /* Next address */
2322 parse_allow_group = FALSE;
2323 parse_found_group = FALSE;
2324 } /* Next header unless yield has been set FALSE */
2330 /*************************************************
2331 * Check header names for 8-bit characters *
2332 *************************************************/
2334 /* This function checks for invalid characters in header names. See
2335 RFC 5322, 2.2. and RFC 6532, 3.
2338 msgptr where to put an error message
2345 verify_check_header_names_ascii(uschar **msgptr)
2350 for (h = header_list; h; h = h->next)
2352 colon = Ustrchr(h->text, ':');
2353 for(s = h->text; s < colon; s++)
2354 if ((*s < 33) || (*s > 126))
2356 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2357 colon - h->text, h->text);
2364 /*************************************************
2365 * Check for blind recipients *
2366 *************************************************/
2368 /* This function checks that every (envelope) recipient is mentioned in either
2369 the To: or Cc: header lines, thus detecting blind carbon copies.
2371 There are two ways of scanning that could be used: either scan the header lines
2372 and tick off the recipients, or scan the recipients and check the header lines.
2373 The original proposed patch did the former, but I have chosen to do the latter,
2374 because (a) it requires no memory and (b) will use fewer resources when there
2375 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2378 Returns: OK if there are no blind recipients
2379 FAIL if there is at least one blind recipient
2383 verify_check_notblind(void)
2386 for (i = 0; i < recipients_count; i++)
2390 uschar *address = recipients_list[i].address;
2392 for (h = header_list; !found && h != NULL; h = h->next)
2396 if (h->type != htype_to && h->type != htype_cc) continue;
2398 colon = Ustrchr(h->text, ':');
2400 while (isspace(*s)) s++;
2402 /* Loop for multiple addresses in the header, enabling group syntax. Note
2403 that we have to reset this after the header has been scanned. */
2405 parse_allow_group = TRUE;
2409 uschar *ss = parse_find_address_end(s, FALSE);
2410 uschar *recipient,*errmess;
2411 int terminator = *ss;
2412 int start, end, domain;
2414 /* Temporarily terminate the string at this point, and extract the
2415 operative address within, allowing group syntax. */
2418 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2421 /* If we found a valid recipient that has a domain, compare it with the
2422 envelope recipient. Local parts are compared case-sensitively, domains
2423 case-insensitively. By comparing from the start with length "domain", we
2424 include the "@" at the end, which ensures that we are comparing the whole
2425 local part of each address. */
2427 if (recipient != NULL && domain != 0)
2429 found = Ustrncmp(recipient, address, domain) == 0 &&
2430 strcmpic(recipient + domain, address + domain) == 0;
2434 /* Advance to the next address */
2436 s = ss + (terminator? 1:0);
2437 while (isspace(*s)) s++;
2438 } /* Next address */
2440 parse_allow_group = FALSE;
2441 parse_found_group = FALSE;
2442 } /* Next header (if found is false) */
2444 if (!found) return FAIL;
2445 } /* Next recipient */
2452 /*************************************************
2453 * Find if verified sender *
2454 *************************************************/
2456 /* Usually, just a single address is verified as the sender of the message.
2457 However, Exim can be made to verify other addresses as well (often related in
2458 some way), and this is useful in some environments. There may therefore be a
2459 chain of such addresses that have previously been tested. This function finds
2460 whether a given address is on the chain.
2462 Arguments: the address to be verified
2463 Returns: pointer to an address item, or NULL
2467 verify_checked_sender(uschar *sender)
2470 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2471 if (Ustrcmp(sender, addr->address) == 0) break;
2479 /*************************************************
2480 * Get valid header address *
2481 *************************************************/
2483 /* Scan the originator headers of the message, looking for an address that
2484 verifies successfully. RFC 822 says:
2486 o The "Sender" field mailbox should be sent notices of
2487 any problems in transport or delivery of the original
2488 messages. If there is no "Sender" field, then the
2489 "From" field mailbox should be used.
2491 o If the "Reply-To" field exists, then the reply should
2492 go to the addresses indicated in that field and not to
2493 the address(es) indicated in the "From" field.
2495 So we check a Sender field if there is one, else a Reply_to field, else a From
2496 field. As some strange messages may have more than one of these fields,
2497 especially if they are resent- fields, check all of them if there is more than
2501 user_msgptr points to where to put a user error message
2502 log_msgptr points to where to put a log error message
2503 callout timeout for callout check (passed to verify_address())
2504 callout_overall overall callout timeout (ditto)
2505 callout_connect connect callout timeout (ditto)
2506 se_mailfrom mailfrom for verify; NULL => ""
2507 pm_mailfrom sender for pm callout check (passed to verify_address())
2508 options callout options (passed to verify_address())
2509 verrno where to put the address basic_errno
2511 If log_msgptr is set to something without setting user_msgptr, the caller
2512 normally uses log_msgptr for both things.
2514 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2515 FAIL is given if no appropriate headers are found
2519 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2520 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2521 uschar *pm_mailfrom, int options, int *verrno)
2523 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2528 for (i = 0; i < 3 && !done; i++)
2531 for (h = header_list; h != NULL && !done; h = h->next)
2533 int terminator, new_ok;
2534 uschar *s, *ss, *endname;
2536 if (h->type != header_types[i]) continue;
2537 s = endname = Ustrchr(h->text, ':') + 1;
2539 /* Scan the addresses in the header, enabling group syntax. Note that we
2540 have to reset this after the header has been scanned. */
2542 parse_allow_group = TRUE;
2546 address_item *vaddr;
2548 while (isspace(*s) || *s == ',') s++;
2549 if (*s == 0) break; /* End of header */
2551 ss = parse_find_address_end(s, FALSE);
2553 /* The terminator is a comma or end of header, but there may be white
2554 space preceding it (including newline for the last address). Move back
2555 past any white space so we can check against any cached envelope sender
2556 address verifications. */
2558 while (isspace(ss[-1])) ss--;
2562 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2563 (int)(endname - h->text), h->text, s);
2565 /* See if we have already verified this address as an envelope sender,
2566 and if so, use the previous answer. */
2568 vaddr = verify_checked_sender(s);
2570 if (vaddr != NULL && /* Previously checked */
2571 (callout <= 0 || /* No callout needed; OR */
2572 vaddr->special_action > 256)) /* Callout was done */
2574 new_ok = vaddr->special_action & 255;
2575 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2576 *ss = terminator; /* Restore shortened string */
2579 /* Otherwise we run the verification now. We must restore the shortened
2580 string before running the verification, so the headers are correct, in
2581 case there is any rewriting. */
2585 int start, end, domain;
2586 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2591 /* If we found an empty address, just carry on with the next one, but
2592 kill the message. */
2594 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2601 /* If verification failed because of a syntax error, fail this
2602 function, and ensure that the failing address gets added to the error
2605 if (address == NULL)
2608 while (ss > s && isspace(ss[-1])) ss--;
2609 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2610 "scanning for sender: %s in \"%.*s\"",
2611 (int)(endname - h->text), h->text, *log_msgptr, (int)(ss - s), s);
2617 /* Else go ahead with the sender verification. But it isn't *the*
2618 sender of the message, so set vopt_fake_sender to stop sender_address
2619 being replaced after rewriting or qualification. */
2623 vaddr = deliver_make_addr(address, FALSE);
2624 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2625 callout, callout_overall, callout_connect, se_mailfrom,
2630 /* We now have the result, either newly found, or cached. If we are
2631 giving out error details, set a specific user error. This means that the
2632 last of these will be returned to the user if all three fail. We do not
2633 set a log message - the generic one below will be used. */
2637 *verrno = vaddr->basic_errno;
2638 if (smtp_return_error_details)
2639 *user_msgptr = string_sprintf("Rejected after DATA: "
2640 "could not verify \"%.*s\" header address\n%s: %s",
2641 (int)(endname - h->text), h->text, vaddr->address, vaddr->message);
2644 /* Success or defer */
2653 if (new_ok == DEFER) yield = DEFER;
2655 /* Move on to any more addresses in the header */
2658 } /* Next address */
2660 parse_allow_group = FALSE;
2661 parse_found_group = FALSE;
2662 } /* Next header, unless done */
2663 } /* Next header type unless done */
2665 if (yield == FAIL && *log_msgptr == NULL)
2666 *log_msgptr = US"there is no valid sender in any header line";
2668 if (yield == DEFER && *log_msgptr == NULL)
2669 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2677 /*************************************************
2678 * Get RFC 1413 identification *
2679 *************************************************/
2681 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2682 the timeout is set to zero, then the query is not done. There may also be lists
2683 of hosts and nets which are exempt. To guard against malefactors sending
2684 non-printing characters which could, for example, disrupt a message's headers,
2685 make sure the string consists of printing characters only.
2688 port the port to connect to; usually this is IDENT_PORT (113), but when
2689 running in the test harness with -bh a different value is used.
2693 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2697 verify_get_ident(int port)
2699 client_conn_ctx ident_conn_ctx = {0};
2701 int received_sender_port, received_interface_port, n;
2704 uschar buffer[2048];
2706 /* Default is no ident. Check whether we want to do an ident check for this
2709 sender_ident = NULL;
2710 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2713 DEBUG(D_ident) debug_printf("doing ident callback\n");
2715 /* Set up a connection to the ident port of the remote host. Bind the local end
2716 to the incoming interface address. If the sender host address is an IPv6
2717 address, the incoming interface address will also be IPv6. */
2719 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2720 if ((ident_conn_ctx.sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2722 if (ip_bind(ident_conn_ctx.sock, host_af, interface_address, 0) < 0)
2724 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2729 /* Construct and send the query. */
2731 qlen = snprintf(CS buffer, sizeof(buffer), "%d , %d\r\n",
2732 sender_host_port, interface_port);
2733 early_data.data = buffer;
2734 early_data.len = qlen;
2736 if (ip_connect(ident_conn_ctx.sock, host_af, sender_host_address, port,
2737 rfc1413_query_timeout, &early_data) < 0)
2739 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2740 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2741 sender_host_address);
2743 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2744 sender_host_address, strerror(errno));
2748 /* Read a response line. We put it into the rest of the buffer, using several
2749 recv() calls if necessary. */
2757 int size = sizeof(buffer) - (p - buffer);
2759 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2760 count = ip_recv(&ident_conn_ctx, p, size, rfc1413_query_timeout);
2761 if (count <= 0) goto END_OFF; /* Read error or EOF */
2763 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2764 generous, and accept a plain \n terminator as well. The only illegal
2767 for (pp = p; pp < p + count; pp++)
2769 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2772 if (pp[-1] == '\r') pp--;
2774 goto GOT_DATA; /* Break out of both loops */
2778 /* Reached the end of the data without finding \n. Let the loop continue to
2779 read some more, if there is room. */
2786 /* We have received a line of data. Check it carefully. It must start with the
2787 same two port numbers that we sent, followed by data as defined by the RFC. For
2790 12345 , 25 : USERID : UNIX :root
2792 However, the amount of white space may be different to what we sent. In the
2793 "osname" field there may be several sub-fields, comma separated. The data we
2794 actually want to save follows the third colon. Some systems put leading spaces
2795 in it - we discard those. */
2797 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2798 &received_interface_port, &n) != 2 ||
2799 received_sender_port != sender_host_port ||
2800 received_interface_port != interface_port)
2803 p = buffer + qlen + n;
2804 while(isspace(*p)) p++;
2805 if (*p++ != ':') goto END_OFF;
2806 while(isspace(*p)) p++;
2807 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2809 while(isspace(*p)) p++;
2810 if (*p++ != ':') goto END_OFF;
2811 while (*p != 0 && *p != ':') p++;
2812 if (*p++ == 0) goto END_OFF;
2813 while(isspace(*p)) p++;
2814 if (*p == 0) goto END_OFF;
2816 /* The rest of the line is the data we want. We turn it into printing
2817 characters when we save it, so that it cannot mess up the format of any logging
2818 or Received: lines into which it gets inserted. We keep a maximum of 127
2819 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2821 sender_ident = US string_printing(string_copyn(p, 127));
2822 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2825 (void)close(ident_conn_ctx.sock);
2832 /*************************************************
2833 * Match host to a single host-list item *
2834 *************************************************/
2836 /* This function compares a host (name or address) against a single item
2837 from a host list. The host name gets looked up if it is needed and is not
2838 already known. The function is called from verify_check_this_host() via
2839 match_check_list(), which is why most of its arguments are in a single block.
2842 arg the argument block (see below)
2843 ss the host-list item
2844 valueptr where to pass back looked up data, or NULL
2845 error for error message when returning ERROR
2848 host_name (a) the host name, or
2849 (b) NULL, implying use sender_host_name and
2850 sender_host_aliases, looking them up if required, or
2851 (c) the empty string, meaning that only IP address matches
2853 host_address the host address
2854 host_ipv4 the IPv4 address taken from an IPv6 one
2858 DEFER lookup deferred
2859 ERROR (a) failed to find the host name or IP address, or
2860 (b) unknown lookup type specified, or
2861 (c) host name encountered when only IP addresses are
2866 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2868 check_host_block *cb = (check_host_block *)arg;
2871 BOOL iplookup = FALSE;
2872 BOOL isquery = FALSE;
2873 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2878 /* Optimize for the special case when the pattern is "*". */
2880 if (*ss == '*' && ss[1] == 0) return OK;
2882 /* If the pattern is empty, it matches only in the case when there is no host -
2883 this can occur in ACL checking for SMTP input using the -bs option. In this
2884 situation, the host address is the empty string. */
2886 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2887 if (*ss == 0) return FAIL;
2889 /* If the pattern is precisely "@" then match against the primary host name,
2890 provided that host name matching is permitted; if it's "@[]" match against the
2891 local host's IP addresses. */
2897 if (isiponly) return ERROR;
2898 ss = primary_hostname;
2900 else if (Ustrcmp(ss, "@[]") == 0)
2902 ip_address_item *ip;
2903 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2904 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2909 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2910 a (possibly masked) comparison with the current IP address. */
2912 if (string_is_ip_address(ss, &maskoffset) != 0)
2913 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2915 /* The pattern is not an IP address. A common error that people make is to omit
2916 one component of an IPv4 address, either by accident, or believing that, for
2917 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,
2918 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2919 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2920 ancient specification.) To aid in debugging these cases, we give a specific
2921 error if the pattern contains only digits and dots or contains a slash preceded
2922 only by digits and dots (a slash at the start indicates a file name and of
2923 course slashes may be present in lookups, but not preceded only by digits and
2926 for (t = ss; isdigit(*t) || *t == '.'; t++);
2927 if (*t == 0 || (*t == '/' && t != ss))
2929 *error = US"malformed IPv4 address or address mask";
2933 /* See if there is a semicolon in the pattern */
2935 semicolon = Ustrchr(ss, ';');
2937 /* If we are doing an IP address only match, then all lookups must be IP
2938 address lookups, even if there is no "net-". */
2942 iplookup = semicolon != NULL;
2945 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2946 a lookup on a masked IP network, in textual form. We obey this code even if we
2947 have already set iplookup, so as to skip over the "net-" prefix and to set the
2948 mask length. The net- stuff really only applies to single-key lookups where the
2949 key is implicit. For query-style lookups the key is specified in the query.
2950 From release 4.30, the use of net- for query style is no longer needed, but we
2951 retain it for backward compatibility. */
2953 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2956 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2957 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2958 iplookup = (*t++ == '-');
2962 /* Do the IP address lookup if that is indeed what we have */
2970 uschar *filename, *key, *result;
2973 /* Find the search type */
2975 search_type = search_findtype(t, semicolon - t);
2977 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2978 search_error_message);
2980 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2981 is no file name, and the "key" is just the query. For query-style with a file
2982 name, we have to fish the file off the start of the query. For a single-key
2983 lookup, the key is the current IP address, masked appropriately, and
2984 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2985 dot separators instead of colons, except when the lookup type is "iplsearch".
2988 if (mac_islookup(search_type, lookup_absfilequery))
2990 filename = semicolon + 1;
2992 while (*key != 0 && !isspace(*key)) key++;
2993 filename = string_copyn(filename, key - filename);
2994 while (isspace(*key)) key++;
2996 else if (mac_islookup(search_type, lookup_querystyle))
2999 key = semicolon + 1;
3001 else /* Single-key style */
3003 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3005 insize = host_aton(cb->host_address, incoming);
3006 host_mask(insize, incoming, mlen);
3007 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3009 filename = semicolon + 1;
3012 /* Now do the actual lookup; note that there is no search_close() because
3013 of the caching arrangements. */
3015 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
3016 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
3018 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3019 if (valueptr != NULL) *valueptr = result;
3020 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3023 /* The pattern is not an IP address or network reference of any kind. That is,
3024 it is a host name pattern. If this is an IP only match, there's an error in the
3029 *error = US"cannot match host name in match_ip list";
3033 /* Check the characters of the pattern to see if they comprise only letters,
3034 digits, full stops, and hyphens (the constituents of domain names). Allow
3035 underscores, as they are all too commonly found. Sigh. Also, if
3036 allow_utf8_domains is set, allow top-bit characters. */
3038 for (t = ss; *t != 0; t++)
3039 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3040 (!allow_utf8_domains || *t < 128)) break;
3042 /* If the pattern is a complete domain name, with no fancy characters, look up
3043 its IP address and match against that. Note that a multi-homed host will add
3044 items to the chain. */
3055 /* Using byname rather than bydns here means we cannot determine dnssec
3056 status. On the other hand it is unclear how that could be either
3057 propagated up or enforced. */
3059 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3060 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3063 for (hh = &h; hh != NULL; hh = hh->next)
3065 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3069 if (rc == HOST_FIND_AGAIN) return DEFER;
3070 *error = string_sprintf("failed to find IP address for %s", ss);
3074 /* Almost all subsequent comparisons require the host name, and can be done
3075 using the general string matching function. When this function is called for
3076 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3077 must use sender_host_name and its aliases, looking them up if necessary. */
3079 if (cb->host_name != NULL) /* Explicit host name given */
3080 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3083 /* Host name not given; in principle we need the sender host name and its
3084 aliases. However, for query-style lookups, we do not need the name if the
3085 query does not contain $sender_host_name. From release 4.23, a reference to
3086 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3089 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3091 const uschar *affix;
3092 int partial, affixlen, starflags, id;
3095 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3098 if (id < 0) /* Unknown lookup type */
3100 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3101 search_error_message, ss);
3104 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3109 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3112 case DEFER: return DEFER;
3113 default: return FAIL;
3117 /* Not a query-style lookup; must ensure the host name is present, and then we
3118 do a check on the name and all its aliases. */
3120 if (!sender_host_name)
3122 HDEBUG(D_host_lookup)
3123 debug_printf("sender host name required, to match against %s\n", ss);
3124 if (host_lookup_failed || host_name_lookup() != OK)
3126 *error = string_sprintf("failed to find host name for %s",
3127 sender_host_address);;
3130 host_build_sender_fullhost();
3133 /* Match on the sender host name, using the general matching function */
3135 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE, valueptr))
3138 case DEFER: return DEFER;
3141 /* If there are aliases, try matching on them. */
3143 aliases = sender_host_aliases;
3145 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3148 case DEFER: return DEFER;
3156 /*************************************************
3157 * Check a specific host matches a host list *
3158 *************************************************/
3160 /* This function is passed a host list containing items in a number of
3161 different formats and the identity of a host. Its job is to determine whether
3162 the given host is in the set of hosts defined by the list. The host name is
3163 passed as a pointer so that it can be looked up if needed and not already
3164 known. This is commonly the case when called from verify_check_host() to check
3165 an incoming connection. When called from elsewhere the host name should usually
3168 This function is now just a front end to match_check_list(), which runs common
3169 code for scanning a list. We pass it the check_host() function to perform a
3173 listptr pointer to the host list
3174 cache_bits pointer to cache for named lists, or NULL
3175 host_name the host name or NULL, implying use sender_host_name and
3176 sender_host_aliases, looking them up if required
3177 host_address the IP address
3178 valueptr if not NULL, data from a lookup is passed back here
3180 Returns: OK if the host is in the defined set
3181 FAIL if the host is not in the defined set,
3182 DEFER if a data lookup deferred (not a host lookup)
3184 If the host name was needed in order to make a comparison, and could not be
3185 determined from the IP address, the result is FAIL unless the item
3186 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3189 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3190 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3193 unsigned int *local_cache_bits = cache_bits;
3194 const uschar *save_host_address = deliver_host_address;
3195 check_host_block cb = { .host_name = host_name, .host_address = host_address };
3197 if (valueptr) *valueptr = NULL;
3199 /* If the host address starts off ::ffff: it is an IPv6 address in
3200 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3203 cb.host_ipv4 = Ustrncmp(host_address, "::ffff:", 7) == 0
3204 ? host_address + 7 : host_address;
3206 /* During the running of the check, put the IP address into $host_address. In
3207 the case of calls from the smtp transport, it will already be there. However,
3208 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3209 the safe side, any existing setting is preserved, though as I write this
3210 (November 2004) I can't see any cases where it is actually needed. */
3212 deliver_host_address = host_address;
3213 rc = match_check_list(
3214 listptr, /* the list */
3215 0, /* separator character */
3216 &hostlist_anchor, /* anchor pointer */
3217 &local_cache_bits, /* cache pointer */
3218 check_host, /* function for testing */
3219 &cb, /* argument for function */
3220 MCL_HOST, /* type of check */
3221 (host_address == sender_host_address)?
3222 US"host" : host_address, /* text for debugging */
3223 valueptr); /* where to pass back data */
3224 deliver_host_address = save_host_address;
3231 /*************************************************
3232 * Check the given host item matches a list *
3233 *************************************************/
3235 verify_check_given_host(uschar **listptr, host_item *host)
3237 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3240 /*************************************************
3241 * Check the remote host matches a list *
3242 *************************************************/
3244 /* This is a front end to verify_check_this_host(), created because checking
3245 the remote host is a common occurrence. With luck, a good compiler will spot
3246 the tail recursion and optimize it. If there's no host address, this is
3247 command-line SMTP input - check against an empty string for the address.
3250 listptr pointer to the host list
3252 Returns: the yield of verify_check_this_host(),
3253 i.e. OK, FAIL, or DEFER
3257 verify_check_host(uschar **listptr)
3259 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3260 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3267 /*************************************************
3268 * Invert an IP address *
3269 *************************************************/
3271 /* Originally just used for DNS xBL lists, now also used for the
3272 reverse_ip expansion operator.
3275 buffer where to put the answer
3276 address the address to invert
3280 invert_address(uschar *buffer, uschar *address)
3283 uschar *bptr = buffer;
3285 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3286 to the IPv4 part only. */
3288 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3290 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3293 if (host_aton(address, bin) == 1)
3297 for (i = 0; i < 4; i++)
3299 sprintf(CS bptr, "%d.", x & 255);
3300 while (*bptr) bptr++;
3305 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3306 in any DNS black lists, and the format in which they will be looked up is
3307 unknown. This is just a guess. */
3313 for (j = 3; j >= 0; j--)
3316 for (i = 0; i < 8; i++)
3318 sprintf(CS bptr, "%x.", x & 15);
3319 while (*bptr) bptr++;
3326 /* Remove trailing period -- this is needed so that both arbitrary
3327 dnsbl keydomains and inverted addresses may be combined with the
3328 same format string, "%s.%s" */
3335 /*************************************************
3336 * Perform a single dnsbl lookup *
3337 *************************************************/
3339 /* This function is called from verify_check_dnsbl() below. It is also called
3340 recursively from within itself when domain and domain_txt are different
3341 pointers, in order to get the TXT record from the alternate domain.
3344 domain the outer dnsbl domain
3345 domain_txt alternate domain to lookup TXT record on success; when the
3346 same domain is to be used, domain_txt == domain (that is,
3347 the pointers must be identical, not just the text)
3348 keydomain the current keydomain (for debug message)
3349 prepend subdomain to lookup (like keydomain, but
3350 reversed if IP address)
3351 iplist the list of matching IP addresses, or NULL for "any"
3352 bitmask true if bitmask matching is wanted
3353 match_type condition for 'succeed' result
3354 0 => Any RR in iplist (=)
3355 1 => No RR in iplist (!=)
3356 2 => All RRs in iplist (==)
3357 3 => Some RRs not in iplist (!==)
3358 the two bits are defined as MT_NOT and MT_ALL
3359 defer_return what to return for a defer
3361 Returns: OK if lookup succeeded
3366 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3367 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3373 dnsbl_cache_block *cb;
3374 int old_pool = store_pool;
3375 uschar query[256]; /* DNS domain max length */
3377 /* Construct the specific query domainname */
3379 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3381 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3382 "(ignored): %s...", query);
3386 /* Look for this query in the cache. */
3388 if ( (t = tree_search(dnsbl_cache, query))
3389 && (cb = t->data.ptr)->expiry > time(NULL)
3392 /* Previous lookup was cached */
3395 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3398 /* If not cached from a previous lookup, we must do a DNS lookup, and
3399 cache the result in permanent memory. */
3405 store_pool = POOL_PERM;
3409 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3413 { /* Set up a tree entry to cache the lookup */
3414 t = store_get(sizeof(tree_node) + Ustrlen(query));
3415 Ustrcpy(t->name, query);
3416 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3417 (void)tree_insertnode(&dnsbl_cache, t);
3420 /* Do the DNS lookup . */
3422 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3423 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3424 cb->text_set = FALSE;
3428 /* If the lookup succeeded, cache the RHS address. The code allows for
3429 more than one address - this was for complete generality and the possible
3430 use of A6 records. However, A6 records are no longer supported. Leave the code
3433 Quite apart from one A6 RR generating multiple addresses, there are DNS
3434 lists that return more than one A record, so we must handle multiple
3435 addresses generated in that way as well.
3437 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3438 or some suitably far-future time if none were found. */
3440 if (cb->rc == DNS_SUCCEED)
3443 dns_address **addrp = &(cb->rhs);
3444 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3446 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3447 if (rr->type == T_A)
3449 dns_address *da = dns_address_from_rr(&dnsa, rr);
3453 while (da->next) da = da->next;
3455 if (ttl > rr->ttl) ttl = rr->ttl;
3459 /* If we didn't find any A records, change the return code. This can
3460 happen when there is a CNAME record but there are no A records for what
3463 if (!cb->rhs) cb->rc = DNS_NODATA;
3466 cb->expiry = time(NULL)+ttl;
3467 store_pool = old_pool;
3470 /* We now have the result of the DNS lookup, either newly done, or cached
3471 from a previous call. If the lookup succeeded, check against the address
3472 list if there is one. This may be a positive equality list (introduced by
3473 "="), a negative equality list (introduced by "!="), a positive bitmask
3474 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3476 if (cb->rc == DNS_SUCCEED)
3478 dns_address *da = NULL;
3479 uschar *addlist = cb->rhs->address;
3481 /* For A and AAAA records, there may be multiple addresses from multiple
3482 records. For A6 records (currently not expected to be used) there may be
3483 multiple addresses from a single record. */
3485 for (da = cb->rhs->next; da; da = da->next)
3486 addlist = string_sprintf("%s, %s", addlist, da->address);
3488 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3491 /* Address list check; this can be either for equality, or via a bitmask.
3492 In the latter case, all the bits must match. */
3496 for (da = cb->rhs; da; da = da->next)
3500 const uschar *ptr = iplist;
3503 /* Handle exact matching */
3507 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))))
3508 if (Ustrcmp(CS da->address, ip) == 0)
3512 /* Handle bitmask matching */
3519 /* At present, all known DNS blocking lists use A records, with
3520 IPv4 addresses on the RHS encoding the information they return. I
3521 wonder if this will linger on as the last vestige of IPv4 when IPv6
3522 is ubiquitous? Anyway, for now we use paranoia code to completely
3523 ignore IPv6 addresses. The default mask is 0, which always matches.
3524 We change this only for IPv4 addresses in the list. */
3526 if (host_aton(da->address, address) == 1) mask = address[0];
3528 /* Scan the returned addresses, skipping any that are IPv6 */
3530 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))))
3532 if (host_aton(ip, address) != 1) continue;
3533 if ((address[0] & mask) == address[0]) break;
3539 (a) An IP address in an any ('=') list matched, or
3540 (b) No IP address in an all ('==') list matched
3542 then we're done searching. */
3544 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3547 /* If da == NULL, either
3549 (a) No IP address in an any ('=') list matched, or
3550 (b) An IP address in an all ('==') list didn't match
3552 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3555 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3563 res = US"was no match"; break;
3565 res = US"was an exclude match"; break;
3567 res = US"was an IP address that did not match"; break;
3569 res = US"were no IP addresses that did not match"; break;
3571 debug_printf("=> but we are not accepting this block class because\n");
3572 debug_printf("=> there %s for %s%c%s\n",
3574 ((match_type & MT_ALL) == 0)? "" : "=",
3575 bitmask? '&' : '=', iplist);
3581 /* Either there was no IP list, or the record matched, implying that the
3582 domain is on the list. We now want to find a corresponding TXT record. If an
3583 alternate domain is specified for the TXT record, call this function
3584 recursively to look that up; this has the side effect of re-checking that
3585 there is indeed an A record at the alternate domain. */
3587 if (domain_txt != domain)
3588 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3589 FALSE, match_type, defer_return);
3591 /* If there is no alternate domain, look up a TXT record in the main domain
3592 if it has not previously been cached. */
3596 cb->text_set = TRUE;
3597 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3600 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3602 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3603 if (rr->type == T_TXT) break;
3606 int len = (rr->data)[0];
3607 if (len > 511) len = 127;
3608 store_pool = POOL_PERM;
3609 cb->text = string_sprintf("%.*s", len, CUS (rr->data+1));
3610 store_pool = old_pool;
3615 dnslist_value = addlist;
3616 dnslist_text = cb->text;
3620 /* There was a problem with the DNS lookup */
3622 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3624 log_write(L_dnslist_defer, LOG_MAIN,
3625 "DNS list lookup defer (probably timeout) for %s: %s", query,
3626 (defer_return == OK)? US"assumed in list" :
3627 (defer_return == FAIL)? US"assumed not in list" :
3628 US"returned DEFER");
3629 return defer_return;
3632 /* No entry was found in the DNS; continue for next domain */
3636 debug_printf("DNS lookup for %s failed\n", query);
3637 debug_printf("=> that means %s is not listed at %s\n",
3647 /*************************************************
3648 * Check host against DNS black lists *
3649 *************************************************/
3651 /* This function runs checks against a list of DNS black lists, until one
3652 matches. Each item on the list can be of the form
3654 domain=ip-address/key
3656 The domain is the right-most domain that is used for the query, for example,
3657 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3658 if the DNS lookup returns a matching IP address. Several addresses may be
3659 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3661 If no key is given, what is looked up in the domain is the inverted IP address
3662 of the current client host. If a key is given, it is used to construct the
3663 domain for the lookup. For example:
3665 dsn.rfc-ignorant.org/$sender_address_domain
3667 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3668 then we check for a TXT record for an error message, and if found, save its
3669 value in $dnslist_text. We also cache everything in a tree, to optimize
3672 The TXT record is normally looked up in the same domain as the A record, but
3673 when many lists are combined in a single DNS domain, this will not be a very
3674 specific message. It is possible to specify a different domain for looking up
3675 TXT records; this is given before the main domain, comma-separated. For
3678 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3679 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3681 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3683 Note: an address for testing RBL is 192.203.178.39
3684 Note: an address for testing DUL is 192.203.178.4
3685 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3689 listptr the domain/address/data list
3690 log_msgptr log message on error
3692 Returns: OK successful lookup (i.e. the address is on the list), or
3693 lookup deferred after +include_unknown
3694 FAIL name not found, or no data found for the given type, or
3695 lookup deferred after +exclude_unknown (default)
3696 DEFER lookup failure, if +defer_unknown was set
3700 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3703 int defer_return = FAIL;
3704 const uschar *list = *listptr;
3707 uschar buffer[1024];
3708 uschar revadd[128]; /* Long enough for IPv6 address */
3710 /* Indicate that the inverted IP address is not yet set up */
3714 /* In case this is the first time the DNS resolver is being used. */
3716 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3718 /* Loop through all the domains supplied, until something matches */
3720 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3723 BOOL bitmask = FALSE;
3730 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3732 /* Deal with special values that change the behaviour on defer */
3734 if (domain[0] == '+')
3736 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3737 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3738 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3740 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3745 /* See if there's explicit data to be looked up */
3747 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3749 /* See if there's a list of addresses supplied after the domain name. This is
3750 introduced by an = or a & character; if preceded by = we require all matches
3751 and if preceded by ! we invert the result. */
3753 if (!(iplist = Ustrchr(domain, '=')))
3756 iplist = Ustrchr(domain, '&');
3759 if (iplist) /* Found either = or & */
3761 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3763 match_type |= MT_NOT;
3767 *iplist++ = 0; /* Terminate domain, move on */
3769 /* If we found = (bitmask == FALSE), check for == or =& */
3771 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3773 bitmask = *iplist++ == '&';
3774 match_type |= MT_ALL;
3779 /* If there is a comma in the domain, it indicates that a second domain for
3780 looking up TXT records is provided, before the main domain. Otherwise we must
3781 set domain_txt == domain. */
3783 domain_txt = domain;
3784 comma = Ustrchr(domain, ',');
3791 /* Check that what we have left is a sensible domain name. There is no reason
3792 why these domains should in fact use the same syntax as hosts and email
3793 domains, but in practice they seem to. However, there is little point in
3794 actually causing an error here, because that would no doubt hold up incoming
3795 mail. Instead, I'll just log it. */
3797 for (s = domain; *s != 0; s++)
3799 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3801 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3802 "strange characters - is this right?", domain);
3807 /* Check the alternate domain if present */
3809 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3811 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3813 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3814 "strange characters - is this right?", domain_txt);
3819 /* If there is no key string, construct the query by adding the domain name
3820 onto the inverted host address, and perform a single DNS lookup. */
3824 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3826 *log_msgptr = string_sprintf
3827 ("cannot test auto-keyed dnslists condition in %s ACL",
3828 acl_wherenames[where]);
3831 if (sender_host_address == NULL) return FAIL; /* can never match */
3832 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3833 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3834 iplist, bitmask, match_type, defer_return);
3837 dnslist_domain = string_copy(domain_txt);
3838 dnslist_matched = string_copy(sender_host_address);
3839 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3840 sender_host_address, dnslist_domain);
3842 if (rc != FAIL) return rc; /* OK or DEFER */
3845 /* If there is a key string, it can be a list of domains or IP addresses to
3846 be concatenated with the main domain. */
3853 uschar keybuffer[256];
3854 uschar keyrevadd[128];
3856 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3857 sizeof(keybuffer))) != NULL)
3859 uschar *prepend = keydomain;
3861 if (string_is_ip_address(keydomain, NULL) != 0)
3863 invert_address(keyrevadd, keydomain);
3864 prepend = keyrevadd;
3867 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3868 bitmask, match_type, defer_return);
3872 dnslist_domain = string_copy(domain_txt);
3873 dnslist_matched = string_copy(keydomain);
3874 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3875 keydomain, dnslist_domain);
3879 /* If the lookup deferred, remember this fact. We keep trying the rest
3880 of the list to see if we get a useful result, and if we don't, we return
3881 DEFER at the end. */
3883 if (rc == DEFER) defer = TRUE;
3884 } /* continue with next keystring domain/address */
3886 if (defer) return DEFER;
3888 } /* continue with next dnsdb outer domain */
3895 /* End of verify.c */