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(int, char, uschar **, int);
46 /*************************************************
47 * Retrieve a callout cache record *
48 *************************************************/
50 /* If a record exists, check whether it has expired.
53 dbm_file an open hints file
55 type "address" or "domain"
56 positive_expire expire time for positive records
57 negative_expire expire time for negative records
59 Returns: the cache record if a non-expired one exists, else NULL
62 static dbdata_callout_cache *
63 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
64 int positive_expire, int negative_expire)
69 dbdata_callout_cache *cache_record;
71 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 dbfn_close(dbm_file);
200 return TRUE; /* Default yield is OK */
204 debug_printf("callout cache: domain rejects random addresses\n");
205 *opt_ptr = options & ~vopt_callout_random;
206 new_domain_record->random_result = ccache_reject;
207 new_domain_record->random_stamp = cache_record->random_stamp;
212 debug_printf("callout cache: need to check random address handling "
213 "(not cached or cache expired)\n");
214 dbfn_close(dbm_file);
218 /* If a postmaster check is requested, but there was a previous failure,
219 there is again no point in carrying on. If a postmaster check is required,
220 but has not been done before, we are going to have to do a callout, so skip
221 remaining cache processing. */
225 if (cache_record->postmaster_result == ccache_reject)
227 setflag(addr, af_verify_pmfail);
229 debug_printf("callout cache: domain does not accept "
230 "RCPT TO:<postmaster@domain>\n");
232 *failure_ptr = US"postmaster";
233 setflag(addr, af_verify_pmfail);
234 addr->user_message = US"(result of earlier verification reused).";
235 dbfn_close(dbm_file);
238 if (cache_record->postmaster_result == ccache_unknown)
241 debug_printf("callout cache: need to check RCPT "
242 "TO:<postmaster@domain> (not cached or cache expired)\n");
243 dbfn_close(dbm_file);
247 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
248 postmaster check if the address itself has to be checked. Also ensure
249 that the value in the cache record is preserved (with its old timestamp).
252 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
253 "TO:<postmaster@domain>\n");
255 new_domain_record->postmaster_result = ccache_accept;
256 new_domain_record->postmaster_stamp = cache_record->postmaster_stamp;
260 /* We can't give a result based on information about the domain. See if there
261 is an unexpired cache record for this specific address (combined with the
262 sender address if we are doing a recipient callout with a non-empty sender).
265 if (!(cache_address_record = (dbdata_callout_cache_address *)
266 get_callout_cache_record(dbm_file, address_key, US"address",
267 callout_cache_positive_expire, callout_cache_negative_expire)))
269 dbfn_close(dbm_file);
273 if (cache_address_record->result == ccache_accept)
276 debug_printf("callout cache: address record is positive\n");
281 debug_printf("callout cache: address record is negative\n");
282 addr->user_message = US"Previous (cached) callout verification failure";
283 *failure_ptr = US"recipient";
287 /* Close the cache database while we actually do the callout for real. */
289 dbfn_close(dbm_file);
296 /* Write results to callout cache
299 cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain,
300 int done, dbdata_callout_cache_address * addr_rec, uschar * address_key)
303 open_db *dbm_file = NULL;
305 /* If we get here with done == TRUE, a successful callout happened, and yield
306 will be set OK or FAIL according to the response to the RCPT command.
307 Otherwise, we looped through the hosts but couldn't complete the business.
308 However, there may be domain-specific information to cache in both cases.
310 The value of the result field in the new_domain record is ccache_unknown if
311 there was an error before or with MAIL FROM:, and errno was not zero,
312 implying some kind of I/O error. We don't want to write the cache in that case.
313 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
315 if (dom_rec->result != ccache_unknown)
316 if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)))
318 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
322 (void)dbfn_write(dbm_file, domain, dom_rec,
323 (int)sizeof(dbdata_callout_cache));
324 HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
325 " result=%d postmaster=%d random=%d\n",
328 dom_rec->postmaster_result,
329 dom_rec->random_result);
332 /* If a definite result was obtained for the callout, cache it unless caching
335 if (done && addr_rec->result != ccache_unknown)
338 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
341 HDEBUG(D_verify) debug_printf("no callout cache available\n");
345 (void)dbfn_write(dbm_file, address_key, addr_rec,
346 (int)sizeof(dbdata_callout_cache_address));
347 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
348 addr_rec->result == ccache_accept ? "positive" : "negative",
353 if (dbm_file) dbfn_close(dbm_file);
357 /* Cutthrough-multi. If the existing cached cutthrough connection matches
358 the one we would make for a subsequent recipient, use it. Send the RCPT TO
359 and check the result, nonpipelined as it may be wanted immediately for
360 recipient-verification.
362 It seems simpler to deal with this case separately from the main callout loop.
363 We will need to remember it has sent, or not, so that rcpt-acl tail code
364 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
366 Return: TRUE for a definitive result for the recipient
369 cutthrough_multi(address_item * addr, host_item * host_list,
370 transport_feedback * tf, int * yield)
375 if (addr->transport == cutthrough.addr.transport)
376 for (host = host_list; host; host = host->next)
377 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
380 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
383 deliver_host = host->name;
384 deliver_host_address = host->address;
385 deliver_host_port = host->port;
386 deliver_domain = addr->domain;
387 transport_name = addr->transport->name;
389 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
391 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
393 || !smtp_get_port(tf->port, addr, &port, US"callout")
395 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
398 smtp_port_for_connect(host, port);
400 if ( ( interface == cutthrough.interface
402 && cutthrough.interface
403 && Ustrcmp(interface, cutthrough.interface) == 0
405 && host->port == cutthrough.host.port
408 uschar * resp = NULL;
410 /* Match! Send the RCPT TO, set done from the response */
412 smtp_write_command(&ctblock, SCMD_FLUSH, "RCPT TO:<%.1000s>\r\n",
413 transport_rcpt_address(addr,
414 addr->transport->rcpt_include_affixes)) >= 0 &&
415 cutthrough_response(cutthrough.fd, '2', &resp, CUTTHROUGH_DATA_TIMEOUT) == '2';
417 /* This would go horribly wrong if a callout fail was ignored by ACL.
418 We punt by abandoning cutthrough on a reject, like the
423 address_item * na = store_get(sizeof(address_item));
424 *na = cutthrough.addr;
425 cutthrough.addr = *addr;
426 cutthrough.addr.host_used = &cutthrough.host;
427 cutthrough.addr.next = na;
433 cancel_cutthrough_connection(TRUE, US"recipient rejected");
434 if (!resp || errno == ETIMEDOUT)
436 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
441 Ustrcpy(resp, US"connection dropped");
444 string_sprintf("response to \"%s\" was: %s",
445 big_buffer, string_printing(resp));
448 string_sprintf("Callout verification failed:\n%s", resp);
450 /* Hard rejection ends the process */
452 if (resp[0] == '5') /* Address rejected */
460 break; /* host_list */
463 cancel_cutthrough_connection(TRUE, US"incompatible connection");
468 /*************************************************
469 * Do callout verification for an address *
470 *************************************************/
472 /* This function is called from verify_address() when the address has routed to
473 a host list, and a callout has been requested. Callouts are expensive; that is
474 why a cache is used to improve the efficiency.
477 addr the address that's been routed
478 host_list the list of hosts to try
479 tf the transport feedback block
481 ifstring "interface" option from transport, or NULL
482 portstring "port" option from transport, or NULL
483 protocolstring "protocol" option from transport, or NULL
484 callout the per-command callout timeout
485 callout_overall the overall callout timeout (if < 0 use 4*callout)
486 callout_connect the callout connection timeout (if < 0 use callout)
487 options the verification options - these bits are used:
488 vopt_is_recipient => this is a recipient address
489 vopt_callout_no_cache => don't use callout cache
490 vopt_callout_fullpm => if postmaster check, do full one
491 vopt_callout_random => do the "random" thing
492 vopt_callout_recipsender => use real sender for recipient
493 vopt_callout_recippmaster => use postmaster for recipient
494 vopt_callout_hold => lazy close connection
495 se_mailfrom MAIL FROM address for sender verify; NULL => ""
496 pm_mailfrom if non-NULL, do the postmaster check with this sender
498 Returns: OK/FAIL/DEFER
502 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
503 int callout, int callout_overall, int callout_connect, int options,
504 uschar *se_mailfrom, uschar *pm_mailfrom)
507 int old_domain_cache_result = ccache_accept;
510 uschar *from_address;
511 uschar *random_local_part = NULL;
512 const uschar *save_deliver_domain = deliver_domain;
513 uschar **failure_ptr = options & vopt_is_recipient
514 ? &recipient_verify_failure : &sender_verify_failure;
515 dbdata_callout_cache new_domain_record;
516 dbdata_callout_cache_address new_address_record;
517 time_t callout_start_time;
519 new_domain_record.result = ccache_unknown;
520 new_domain_record.postmaster_result = ccache_unknown;
521 new_domain_record.random_result = ccache_unknown;
523 memset(&new_address_record, 0, sizeof(new_address_record));
525 /* For a recipient callout, the key used for the address cache record must
526 include the sender address if we are using the real sender in the callout,
527 because that may influence the result of the callout. */
529 if (options & vopt_is_recipient)
530 if (options & vopt_callout_recipsender)
532 from_address = sender_address;
533 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
534 if (cutthrough.delivery) options |= vopt_callout_no_cache;
536 else if (options & vopt_callout_recippmaster)
538 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
539 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
540 qualify_domain_sender);
545 address_key = addr->address;
548 /* For a sender callout, we must adjust the key if the mailfrom address is not
553 from_address = se_mailfrom ? se_mailfrom : US"";
554 address_key = *from_address
555 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
558 if (cached_callout_lookup(addr, address_key, from_address,
559 &options, &pm_mailfrom, &yield, failure_ptr,
560 &new_domain_record, &old_domain_cache_result))
562 cancel_cutthrough_connection(TRUE, US"cache-hit");
566 if (!addr->transport)
568 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
570 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
571 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
572 addr->transport->name, addr->transport->driver_name);
575 smtp_transport_options_block *ob =
576 (smtp_transport_options_block *)addr->transport->options_block;
579 /* The information wasn't available in the cache, so we have to do a real
580 callout and save the result in the cache for next time, unless no_cache is set,
581 or unless we have a previously cached negative random result. If we are to test
582 with a random local part, ensure that such a local part is available. If not,
583 log the fact, but carry on without randomising. */
585 if (options & vopt_callout_random && callout_random_local_part)
586 if (!(random_local_part = expand_string(callout_random_local_part)))
587 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
588 "callout_random_local_part: %s", expand_string_message);
590 /* Default the connect and overall callout timeouts if not set, and record the
591 time we are starting so that we can enforce it. */
593 if (callout_overall < 0) callout_overall = 4 * callout;
594 if (callout_connect < 0) callout_connect = callout;
595 callout_start_time = time(NULL);
597 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
598 output because a callout might take some time. When PIPELINING is active and
599 there are many recipients, the total time for doing lots of callouts can add up
600 and cause the client to time out. So in this case we forgo the PIPELINING
603 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
605 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
606 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
608 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
609 and we are holding a cutthrough conn open, we can just append the rcpt to
610 that conn for verification purposes (and later delivery also). Simplest
611 coding means skipping this whole loop and doing the append separately. */
613 /* Can we re-use an open cutthrough connection? */
614 if ( cutthrough.fd >= 0
615 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
616 == vopt_callout_recipsender
617 && !random_local_part
620 done = cutthrough_multi(addr, host_list, tf, &yield);
622 /* If we did not use a cached connection, make connections to the hosts
623 and do real callouts. The list of hosts is passed in as an argument. */
625 for (host = host_list; host && !done; host = host->next)
629 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
634 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
639 /* Check the overall callout timeout */
641 if (time(NULL) - callout_start_time >= callout_overall)
643 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
647 /* Set IPv4 or IPv6 */
649 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
651 /* Expand and interpret the interface and port strings. The latter will not
652 be used if there is a host-specific port (e.g. from a manualroute router).
653 This has to be delayed till now, because they may expand differently for
654 different hosts. If there's a failure, log it, but carry on with the
657 deliver_host = host->name;
658 deliver_host_address = host->address;
659 deliver_host_port = host->port;
660 deliver_domain = addr->domain;
661 transport_name = addr->transport->name;
663 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
665 || !smtp_get_port(tf->port, addr, &port, US"callout")
667 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
672 sx.host_af = host_af,
674 sx.interface = interface;
675 sx.helo_data = tf->helo_data;
676 sx.tblock = addr->transport;
679 tls_retry_connection:
680 /* Set the address state so that errors are recorded in it */
682 addr->transport_return = PENDING_DEFER;
683 ob->connect_timeout = callout_connect;
684 ob->command_timeout = callout;
686 /* Get the channel set up ready for a message (MAIL FROM being the next
687 SMTP command to send. If we tried TLS but it failed, try again without
690 yield = smtp_setup_conn(&sx, FALSE);
693 && addr->basic_errno == ERRNO_TLSFAILURE
694 && ob->tls_tempfail_tryclear
695 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
698 log_write(0, LOG_MAIN,
699 "%s: callout unencrypted to %s [%s] (not in hosts_require_tls)",
700 addr->message, host->name, host->address);
701 addr->transport_return = PENDING_DEFER;
702 yield = smtp_setup_conn(&sx, TRUE);
707 errno = addr->basic_errno;
708 transport_name = NULL;
709 deliver_host = deliver_host_address = NULL;
710 deliver_domain = save_deliver_domain;
712 /* Failure to accept HELO is cached; this blocks the whole domain for all
713 senders. I/O errors and defer responses are not cached. */
715 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
717 setflag(addr, af_verify_nsfail);
718 new_domain_record.result = ccache_reject;
726 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
727 the AUTH info for logging */
729 addr->authenticator = client_authenticator;
730 addr->auth_id = client_authenticated_id;
732 sx.from_addr = from_address;
733 sx.first_addr = sx.sync_addr = addr;
734 sx.ok = FALSE; /*XXX these 3 last might not be needed for verify? */
736 sx.completed_addr = FALSE;
738 new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull
739 ? ccache_reject_mfnull : ccache_accept;
741 /* Do the random local part check first. Temporarily replace the recipient
742 with the "random" value */
744 if (random_local_part)
746 uschar * main_address = addr->address;
747 const uschar * rcpt_domain = addr->domain;
750 uschar * errstr = NULL;
751 if ( testflag(addr, af_utf8_downcvt)
752 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
756 addr->message = errstr;
757 errno = ERRNO_EXPANDFAIL;
758 setflag(addr, af_verify_nsfail);
760 rcpt_domain = US""; /*XXX errorhandling! */
764 /* This would be ok for 1st rcpt of a cutthrough (the case handled here;
765 subsequents are done in cutthrough_multi()), but no way to
766 handle a subsequent because of the RSET vaporising the MAIL FROM.
767 So refuse to support any. Most cutthrough use will not involve
768 random_local_part, so no loss. */
769 cancel_cutthrough_connection(TRUE, US"random-recipient");
771 addr->address = string_sprintf("%s@%.1000s",
772 random_local_part, rcpt_domain);
775 /* If accepted, we aren't going to do any further tests below.
776 Otherwise, cache a real negative response, and get back to the right
777 state to send RCPT. Unless there's some problem such as a dropped
778 connection, we expect to succeed, because the commands succeeded above.
779 However, some servers drop the connection after responding to an
780 invalid recipient, so on (any) error we drop and remake the connection.
781 XXX We don't care about that for postmaster_full. Should we?
783 XXX could we add another flag to the context, and have the common
784 code emit the RSET too? Even pipelined after the RCPT...
785 Then the main-verify call could use it if there's to be a subsequent
787 The sync_responses() would need to be taught about it and we'd
788 need another return code filtering out to here.
790 Avoid using a SIZE option on the MAIL for all randon-rcpt checks.
793 sx.avoid_option = OPTION_SIZE;
795 /* Remember when we last did a random test */
796 new_domain_record.random_stamp = time(NULL);
798 if (smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0)
799 switch(addr->transport_return)
801 case PENDING_OK: /* random was accepted, unfortunately */
802 new_domain_record.random_result = ccache_accept;
803 yield = OK; /* Only usable verify result we can return */
806 case FAIL: /* rejected: the preferred result */
807 new_domain_record.random_result = ccache_reject;
810 /* Between each check, issue RSET, because some servers accept only
811 one recipient after MAIL FROM:<>.
812 XXX We don't care about that for postmaster_full. Should we? */
815 smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0 &&
816 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
821 debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
822 random_local_part = NULL;
824 tls_close(FALSE, TLS_SHUTDOWN_NOWAIT);
826 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
827 (void)close(sx.inblock.sock);
828 sx.inblock.sock = sx.outblock.sock = -1;
829 #ifndef DISABLE_EVENT
830 (void) event_raise(addr->transport->event_action,
831 US"tcp:close", NULL);
833 addr->address = main_address;
834 addr->transport_return = PENDING_DEFER;
835 sx.first_addr = sx.sync_addr = addr;
838 sx.completed_addr = FALSE;
839 goto tls_retry_connection;
840 case DEFER: /* 4xx response to random */
841 break; /* Just to be clear. ccache_unknown, !done. */
844 /* Re-setup for main verify, or for the error message when failing */
845 addr->address = main_address;
846 addr->transport_return = PENDING_DEFER;
847 sx.first_addr = sx.sync_addr = addr;
850 sx.completed_addr = FALSE;
855 /* Main verify. For rcpt-verify use SIZE if we know it and we're not cacheing;
856 for sndr-verify never use it. */
860 if (!(options & vopt_is_recipient && options & vopt_callout_no_cache))
861 sx.avoid_option = OPTION_SIZE;
864 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
866 case 0: switch(addr->transport_return) /* ok so far */
868 case PENDING_OK: done = TRUE;
869 new_address_record.result = ccache_accept;
871 case FAIL: done = TRUE;
873 *failure_ptr = US"recipient";
874 new_address_record.result = ccache_reject;
880 case -1: /* MAIL response error */
881 *failure_ptr = US"mail";
882 if (errno == 0 && sx.buffer[0] == '5')
884 setflag(addr, af_verify_nsfail);
885 if (from_address[0] == 0)
886 new_domain_record.result = ccache_reject_mfnull;
889 /* non-MAIL read i/o error */
890 /* non-MAIL response timeout */
891 /* internal error; channel still usable */
892 default: break; /* transmit failed */
896 addr->auth_sndr = client_authenticated_sender;
898 deliver_host = deliver_host_address = NULL;
899 deliver_domain = save_deliver_domain;
901 /* Do postmaster check if requested; if a full check is required, we
902 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
904 if (done && pm_mailfrom)
906 /* Could possibly shift before main verify, just above, and be ok
907 for cutthrough. But no way to handle a subsequent rcpt, so just
909 cancel_cutthrough_connection(TRUE, US"postmaster verify");
910 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
912 done = smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0
913 && smtp_read_response(&sx.inblock, sx.buffer,
914 sizeof(sx.buffer), '2', callout);
918 uschar * main_address = addr->address;
920 /*XXX oops, affixes */
921 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
922 addr->transport_return = PENDING_DEFER;
924 sx.from_addr = pm_mailfrom;
925 sx.first_addr = sx.sync_addr = addr;
928 sx.completed_addr = FALSE;
929 sx.avoid_option = OPTION_SIZE;
931 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
932 && addr->transport_return == PENDING_OK
936 done = (options & vopt_callout_fullpm) != 0
937 && smtp_write_command(&sx.outblock, SCMD_FLUSH,
938 "RCPT TO:<postmaster>\r\n") >= 0
939 && smtp_read_response(&sx.inblock, sx.buffer,
940 sizeof(sx.buffer), '2', callout);
942 /* Sort out the cache record */
944 new_domain_record.postmaster_stamp = time(NULL);
947 new_domain_record.postmaster_result = ccache_accept;
948 else if (errno == 0 && sx.buffer[0] == '5')
950 *failure_ptr = US"postmaster";
951 setflag(addr, af_verify_pmfail);
952 new_domain_record.postmaster_result = ccache_reject;
955 addr->address = main_address;
958 /* For any failure of the main check, other than a negative response, we just
959 close the connection and carry on. We can identify a negative response by the
960 fact that errno is zero. For I/O errors it will be non-zero
962 Set up different error texts for logging and for sending back to the caller
963 as an SMTP response. Log in all cases, using a one-line format. For sender
964 callouts, give a full response to the caller, but for recipient callouts,
965 don't give the IP address because this may be an internal host whose identity
966 is not to be widely broadcast. */
972 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
973 sx.send_quit = FALSE;
979 extern int acl_where; /* src/acl.c */
981 addr->message = string_sprintf(
982 "response to \"EHLO\" did not include SMTPUTF8");
983 addr->user_message = acl_where == ACL_WHERE_RCPT
984 ? US"533 no support for internationalised mailbox name"
985 : US"550 mailbox unavailable";
992 sx.send_quit = FALSE;
996 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
998 /*XXX test here is ugly; seem to have a split of responsibility for
999 building this message. Need to rationalise. Where is it done
1000 before here, and when not?
1001 Not == 5xx resp to MAIL on main-verify
1003 if (!addr->message) addr->message =
1004 string_sprintf("response to \"%s\" was: %s",
1005 big_buffer, string_printing(sx.buffer));
1007 addr->user_message = options & vopt_is_recipient
1008 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
1009 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1010 host->address, big_buffer, sx.buffer);
1012 /* Hard rejection ends the process */
1014 if (sx.buffer[0] == '5') /* Address rejected */
1022 /* End the SMTP conversation and close the connection. */
1024 /* Cutthrough - on a successful connect and recipient-verify with
1025 use-sender and we are 1st rcpt and have no cutthrough conn so far
1026 here is where we want to leave the conn open. Ditto for a lazy-close
1029 if (cutthrough.delivery)
1031 if (addr->transport->filter_command)
1033 cutthrough.delivery= FALSE;
1034 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
1036 #ifndef DISABLE_DKIM
1037 if (ob->dkim.dkim_domain)
1039 cutthrough.delivery= FALSE;
1040 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
1043 #ifdef EXPERIMENTAL_ARC
1046 cutthrough.delivery= FALSE;
1047 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of ARC signing\n");
1052 if ( (cutthrough.delivery || options & vopt_callout_hold)
1056 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1057 == vopt_callout_recipsender
1058 && !random_local_part
1060 && cutthrough.fd < 0
1064 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for %s\n",
1066 ? "cutthrough delivery" : "potential further verifies and delivery");
1068 cutthrough.callout_hold_only = !cutthrough.delivery;
1069 cutthrough.is_tls = tls_out.active >= 0;
1070 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1071 cutthrough.nrcpt = 1;
1072 cutthrough.transport = addr->transport->name;
1073 cutthrough.interface = interface;
1074 cutthrough.snd_port = sending_port;
1075 cutthrough.peer_options = smtp_peer_options;
1076 cutthrough.host = *host;
1078 int oldpool = store_pool;
1079 store_pool = POOL_PERM;
1080 cutthrough.snd_ip = string_copy(sending_ip_address);
1081 cutthrough.host.name = string_copy(host->name);
1082 cutthrough.host.address = string_copy(host->address);
1083 store_pool = oldpool;
1085 cutthrough.addr = *addr; /* Save the address_item for later logging */
1086 cutthrough.addr.next = NULL;
1087 cutthrough.addr.host_used = &cutthrough.host;
1089 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1091 ctblock.buffer = ctbuffer;
1092 ctblock.buffersize = sizeof(ctbuffer);
1093 ctblock.ptr = ctbuffer;
1094 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1095 ctblock.sock = cutthrough.fd;
1099 /* Ensure no cutthrough on multiple verifies that were incompatible */
1100 if (options & vopt_callout_recipsender)
1101 cancel_cutthrough_connection(TRUE, US"not usable for cutthrough");
1104 (void) smtp_write_command(&sx.outblock, SCMD_FLUSH, "QUIT\r\n");
1106 /* Wait a short time for response, and discard it */
1107 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1111 if (sx.inblock.sock >= 0)
1114 tls_close(FALSE, TLS_SHUTDOWN_NOWAIT);
1116 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1117 (void)close(sx.inblock.sock);
1118 sx.inblock.sock = sx.outblock.sock = -1;
1119 #ifndef DISABLE_EVENT
1120 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1125 if (!done || yield != OK)
1126 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1128 } /* Loop through all hosts, while !done */
1131 /* If we get here with done == TRUE, a successful callout happened, and yield
1132 will be set OK or FAIL according to the response to the RCPT command.
1133 Otherwise, we looped through the hosts but couldn't complete the business.
1134 However, there may be domain-specific information to cache in both cases. */
1136 if (!(options & vopt_callout_no_cache))
1137 cache_callout_write(&new_domain_record, addr->domain,
1138 done, &new_address_record, address_key);
1140 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1141 temporary error. If there was only one host, and a response was received, leave
1142 it alone if supplying details. Otherwise, give a generic response. */
1146 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1147 options & vopt_is_recipient ? "recipient" : "sender");
1150 addr->message = host_list->next || !addr->message
1151 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1153 addr->user_message = smtp_return_error_details
1154 ? string_sprintf("%s for <%s>.\n"
1155 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1156 "they may be permanently unreachable from this server. In the latter case,\n%s",
1157 dullmsg, addr->address,
1158 options & vopt_is_recipient
1159 ? "the address will never be accepted."
1160 : "you need to change the address or create an MX record for its domain\n"
1161 "if it is supposed to be generally accessible from the Internet.\n"
1162 "Talk to your mail administrator for details.")
1165 /* Force a specific error code */
1167 addr->basic_errno = ERRNO_CALLOUTDEFER;
1170 /* Come here from within the cache-reading code on fast-track exit. */
1173 tls_modify_variables(&tls_in);
1179 /* Called after recipient-acl to get a cutthrough connection open when
1180 one was requested and a recipient-verify wasn't subsequently done.
1183 open_cutthrough_connection( address_item * addr )
1188 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1189 /* We must use a copy of the address for verification, because it might
1193 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1194 rcpt_count > 1 ? "more" : "start");
1195 rc = verify_address(&addr2, NULL,
1196 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1197 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1199 addr->message = addr2.message;
1200 addr->user_message = addr2.user_message;
1201 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1207 /* Send given number of bytes from the buffer */
1209 cutthrough_send(int n)
1211 if(cutthrough.fd < 0)
1216 tls_out.active == cutthrough.fd ? tls_write(FALSE, ctblock.buffer, n, FALSE) :
1218 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1221 transport_count += n;
1222 ctblock.ptr= ctblock.buffer;
1226 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1233 _cutthrough_puts(uschar * cp, int n)
1237 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1238 if(!cutthrough_send(ctblock.buffersize))
1241 *ctblock.ptr++ = *cp++;
1246 /* Buffered output of counted data block. Return boolean success */
1248 cutthrough_puts(uschar * cp, int n)
1250 if (cutthrough.fd < 0) return TRUE;
1251 if (_cutthrough_puts(cp, n)) return TRUE;
1252 cancel_cutthrough_connection(TRUE, US"transmit failed");
1257 cutthrough_data_puts(uschar * cp, int n)
1259 if (cutthrough.delivery) (void) cutthrough_puts(cp, n);
1265 _cutthrough_flush_send(void)
1267 int n = ctblock.ptr - ctblock.buffer;
1270 if(!cutthrough_send(n))
1276 /* Send out any bufferred output. Return boolean success. */
1278 cutthrough_flush_send(void)
1280 if (_cutthrough_flush_send()) return TRUE;
1281 cancel_cutthrough_connection(TRUE, US"transmit failed");
1287 cutthrough_put_nl(void)
1289 return cutthrough_puts(US"\r\n", 2);
1294 cutthrough_data_put_nl(void)
1296 cutthrough_data_puts(US"\r\n", 2);
1300 /* Get and check response from cutthrough target */
1302 cutthrough_response(int fd, char expect, uschar ** copy, int timeout)
1304 smtp_inblock inblock;
1305 uschar inbuffer[4096];
1306 uschar responsebuffer[4096];
1308 inblock.buffer = inbuffer;
1309 inblock.buffersize = sizeof(inbuffer);
1310 inblock.ptr = inbuffer;
1311 inblock.ptrend = inbuffer;
1313 /* this relies on (inblock.sock == tls_out.active) */
1314 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1315 cancel_cutthrough_connection(TRUE, US"target timeout on read");
1320 *copy = cp = string_copy(responsebuffer);
1321 /* Trim the trailing end of line */
1322 cp += Ustrlen(responsebuffer);
1323 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1324 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1327 return responsebuffer[0];
1331 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1333 cutthrough_predata(void)
1335 if(cutthrough.fd < 0 || cutthrough.callout_hold_only)
1338 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1339 cutthrough_puts(US"DATA\r\n", 6);
1340 cutthrough_flush_send();
1342 /* Assume nothing buffered. If it was it gets ignored. */
1343 return cutthrough_response(cutthrough.fd, '3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1347 /* tctx arg only to match write_chunk() */
1349 cutthrough_write_chunk(transport_ctx * tctx, uschar * s, int len)
1352 while(s && (s2 = Ustrchr(s, '\n')))
1354 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1362 /* Buffered send of headers. Return success boolean. */
1363 /* Expands newlines to wire format (CR,NL). */
1364 /* Also sends header-terminating blank line. */
1366 cutthrough_headers_send(void)
1370 if(cutthrough.fd < 0 || cutthrough.callout_hold_only)
1373 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1374 but having a separate buffered-output function (for now)
1376 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1378 tctx.u.fd = cutthrough.fd;
1379 tctx.tblock = cutthrough.addr.transport;
1380 tctx.addr = &cutthrough.addr;
1381 tctx.check_string = US".";
1382 tctx.escape_string = US"..";
1383 /*XXX check under spool_files_wireformat. Might be irrelevant */
1384 tctx.options = topt_use_crlf;
1386 if (!transport_headers_send(&tctx, &cutthrough_write_chunk))
1389 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1395 close_cutthrough_connection(const uschar * why)
1397 int fd = cutthrough.fd;
1400 /* We could be sending this after a bunch of data, but that is ok as
1401 the only way to cancel the transfer in dataphase is to drop the tcp
1402 conn before the final dot.
1404 ctblock.ptr = ctbuffer;
1405 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1406 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1407 _cutthrough_flush_send();
1408 cutthrough.fd = -1; /* avoid recursion via read timeout */
1409 cutthrough.nrcpt = 0; /* permit re-cutthrough on subsequent message */
1411 /* Wait a short time for response, and discard it */
1412 cutthrough_response(fd, '2', NULL, 1);
1415 tls_close(FALSE, TLS_SHUTDOWN_NOWAIT);
1417 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1419 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1421 ctblock.ptr = ctbuffer;
1425 cancel_cutthrough_connection(BOOL close_noncutthrough_verifies, const uschar * why)
1427 if (cutthrough.delivery || close_noncutthrough_verifies)
1428 close_cutthrough_connection(why);
1429 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1434 release_cutthrough_connection(const uschar * why)
1436 if (cutthrough.fd < 0) return;
1437 HDEBUG(D_acl) debug_printf_indent("release cutthrough conn: %s\n", why);
1439 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1445 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1446 Log an OK response as a transmission.
1447 Close the connection.
1448 Return smtp response-class digit.
1451 cutthrough_finaldot(void)
1454 address_item * addr;
1455 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1457 /* Assume data finshed with new-line */
1458 if( !cutthrough_puts(US".", 1)
1459 || !cutthrough_put_nl()
1460 || !cutthrough_flush_send()
1462 return cutthrough.addr.message;
1464 res = cutthrough_response(cutthrough.fd, '2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1465 for (addr = &cutthrough.addr; addr; addr = addr->next)
1467 addr->message = cutthrough.addr.message;
1471 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1472 close_cutthrough_connection(US"delivered");
1476 delivery_log(LOG_MAIN, addr, 0,
1477 US"tmp-reject from cutthrough after DATA:");
1481 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1482 US"rejected after DATA:");
1489 return cutthrough.addr.message;
1494 /*************************************************
1495 * Copy error to toplevel address *
1496 *************************************************/
1498 /* This function is used when a verify fails or defers, to ensure that the
1499 failure or defer information is in the original toplevel address. This applies
1500 when an address is redirected to a single new address, and the failure or
1501 deferral happens to the child address.
1504 vaddr the verify address item
1505 addr the final address item
1508 Returns: the value of YIELD
1512 copy_error(address_item *vaddr, address_item *addr, int yield)
1516 vaddr->message = addr->message;
1517 vaddr->user_message = addr->user_message;
1518 vaddr->basic_errno = addr->basic_errno;
1519 vaddr->more_errno = addr->more_errno;
1520 vaddr->prop.address_data = addr->prop.address_data;
1521 copyflag(vaddr, addr, af_pass_message);
1529 /**************************************************
1530 * printf that automatically handles TLS if needed *
1531 ***************************************************/
1533 /* This function is used by verify_address() as a substitute for all fprintf()
1534 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1535 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1536 that assumes that we always use the smtp_out FILE* when not using TLS or the
1537 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1538 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1542 f the candidate FILE* to write to
1543 format format string
1544 ... optional arguments
1550 static void PRINTF_FUNCTION(2,3)
1551 respond_printf(FILE *f, const char *format, ...)
1555 va_start(ap, format);
1556 if (smtp_out && (f == smtp_out))
1557 smtp_vprintf(format, FALSE, ap);
1559 vfprintf(f, format, ap);
1565 /*************************************************
1566 * Verify an email address *
1567 *************************************************/
1569 /* This function is used both for verification (-bv and at other times) and
1570 address testing (-bt), which is indicated by address_test_mode being set.
1573 vaddr contains the address to verify; the next field in this block
1575 f if not NULL, write the result to this file
1576 options various option bits:
1577 vopt_fake_sender => this sender verify is not for the real
1578 sender (it was verify=sender=xxxx or an address from a
1579 header line) - rewriting must not change sender_address
1580 vopt_is_recipient => this is a recipient address, otherwise
1581 it's a sender address - this affects qualification and
1582 rewriting and messages from callouts
1583 vopt_qualify => qualify an unqualified address; else error
1584 vopt_expn => called from SMTP EXPN command
1585 vopt_success_on_redirect => when a new address is generated
1586 the verification instantly succeeds
1588 These ones are used by do_callout() -- the options variable
1591 vopt_callout_fullpm => if postmaster check, do full one
1592 vopt_callout_no_cache => don't use callout cache
1593 vopt_callout_random => do the "random" thing
1594 vopt_callout_recipsender => use real sender for recipient
1595 vopt_callout_recippmaster => use postmaster for recipient
1597 callout if > 0, specifies that callout is required, and gives timeout
1598 for individual commands
1599 callout_overall if > 0, gives overall timeout for the callout function;
1600 if < 0, a default is used (see do_callout())
1601 callout_connect the connection timeout for callouts
1602 se_mailfrom when callout is requested to verify a sender, use this
1603 in MAIL FROM; NULL => ""
1604 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1605 thing and use this as the sender address (may be "")
1607 routed if not NULL, set TRUE if routing succeeded, so we can
1608 distinguish between routing failed and callout failed
1610 Returns: OK address verified
1611 FAIL address failed to verify
1612 DEFER can't tell at present
1616 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1617 int callout_overall, int callout_connect, uschar *se_mailfrom,
1618 uschar *pm_mailfrom, BOOL *routed)
1621 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1622 BOOL expn = (options & vopt_expn) != 0;
1623 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1626 int verify_type = expn? v_expn :
1627 address_test_mode? v_none :
1628 options & vopt_is_recipient? v_recipient : v_sender;
1629 address_item *addr_list;
1630 address_item *addr_new = NULL;
1631 address_item *addr_remote = NULL;
1632 address_item *addr_local = NULL;
1633 address_item *addr_succeed = NULL;
1634 uschar **failure_ptr = options & vopt_is_recipient
1635 ? &recipient_verify_failure : &sender_verify_failure;
1636 uschar *ko_prefix, *cr;
1637 uschar *address = vaddr->address;
1638 uschar *save_sender;
1639 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1641 /* Clear, just in case */
1643 *failure_ptr = NULL;
1645 /* Set up a prefix and suffix for error message which allow us to use the same
1646 output statements both in EXPN mode (where an SMTP response is needed) and when
1647 debugging with an output file. */
1651 ko_prefix = US"553 ";
1654 else ko_prefix = cr = US"";
1656 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1658 if (parse_find_at(address) == NULL)
1660 if ((options & vopt_qualify) == 0)
1663 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1664 ko_prefix, address, cr);
1665 *failure_ptr = US"qualify";
1668 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1673 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1674 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1677 /* Rewrite and report on it. Clear the domain and local part caches - these
1678 may have been set by domains and local part tests during an ACL. */
1680 if (global_rewrite_rules != NULL)
1682 uschar *old = address;
1683 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1684 global_rewrite_rules, rewrite_existflags);
1687 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1688 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1689 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1693 /* If this is the real sender address, we must update sender_address at
1694 this point, because it may be referred to in the routers. */
1696 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1697 sender_address = address;
1699 /* If the address was rewritten to <> no verification can be done, and we have
1700 to return OK. This rewriting is permitted only for sender addresses; for other
1701 addresses, such rewriting fails. */
1703 if (address[0] == 0) return OK;
1705 /* Flip the legacy TLS-related variables over to the outbound set in case
1706 they're used in the context of a transport used by verification. Reset them
1707 at exit from this routine (so no returns allowed from here on). */
1709 tls_modify_variables(&tls_out);
1711 /* Save a copy of the sender address for re-instating if we change it to <>
1712 while verifying a sender address (a nice bit of self-reference there). */
1714 save_sender = sender_address;
1716 /* Observability variable for router/transport use */
1718 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1720 /* Update the address structure with the possibly qualified and rewritten
1721 address. Set it up as the starting address on the chain of new addresses. */
1723 vaddr->address = address;
1726 /* We need a loop, because an address can generate new addresses. We must also
1727 cope with generated pipes and files at the top level. (See also the code and
1728 comment in deliver.c.) However, it is usually the case that the router for
1729 user's .forward files has its verify flag turned off.
1731 If an address generates more than one child, the loop is used only when
1732 full_info is set, and this can only be set locally. Remote enquiries just get
1733 information about the top level address, not anything that it generated. */
1738 address_item *addr = addr_new;
1740 addr_new = addr->next;
1745 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1746 debug_printf("Considering %s\n", addr->address);
1749 /* Handle generated pipe, file or reply addresses. We don't get these
1750 when handling EXPN, as it does only one level of expansion. */
1752 if (testflag(addr, af_pfr))
1759 if (addr->address[0] == '>')
1761 allow = testflag(addr, af_allow_reply);
1762 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1766 allow = (addr->address[0] == '|')?
1767 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1768 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1771 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1772 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1773 "%s\n", addr->message);
1775 fprintf(f, "\n transport = %s\n", addr->transport->name);
1777 fprintf(f, " *** forbidden ***\n");
1782 /* Just in case some router parameter refers to it. */
1784 return_path = addr->prop.errors_address
1785 ? addr->prop.errors_address : sender_address;
1787 /* Split the address into domain and local part, handling the %-hack if
1788 necessary, and then route it. While routing a sender address, set
1789 $sender_address to <> because that is what it will be if we were trying to
1790 send a bounce to the sender. */
1792 if (routed) *routed = FALSE;
1793 if ((rc = deliver_split_address(addr)) == OK)
1795 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1796 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1797 &addr_succeed, verify_type);
1798 sender_address = save_sender; /* Put back the real sender */
1801 /* If routing an address succeeded, set the flag that remembers, for use when
1802 an ACL cached a sender verify (in case a callout fails). Then if routing set
1803 up a list of hosts or the transport has a host list, and the callout option
1804 is set, and we aren't in a host checking run, do the callout verification,
1805 and set another flag that notes that a callout happened. */
1809 if (routed) *routed = TRUE;
1812 transport_instance * tp;
1813 host_item * host_list = addr->host_list;
1815 /* Make up some data for use in the case where there is no remote
1818 transport_feedback tf = {
1819 .interface = NULL, /* interface (=> any) */
1821 .protocol = US"smtp",
1823 .helo_data = US"$smtp_active_hostname",
1824 .hosts_override = FALSE,
1825 .hosts_randomize = FALSE,
1826 .gethostbyname = FALSE,
1827 .qualify_single = TRUE,
1828 .search_parents = FALSE
1831 /* If verification yielded a remote transport, we want to use that
1832 transport's options, so as to mimic what would happen if we were really
1833 sending a message to this address. */
1835 if ((tp = addr->transport) && !tp->info->local)
1837 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1839 /* If the transport has hosts and the router does not, or if the
1840 transport is configured to override the router's hosts, we must build a
1841 host list of the transport's hosts, and find the IP addresses */
1843 if (tf.hosts && (!host_list || tf.hosts_override))
1846 const uschar *save_deliver_domain = deliver_domain;
1847 uschar *save_deliver_localpart = deliver_localpart;
1849 host_list = NULL; /* Ignore the router's hosts */
1851 deliver_domain = addr->domain;
1852 deliver_localpart = addr->local_part;
1853 s = expand_string(tf.hosts);
1854 deliver_domain = save_deliver_domain;
1855 deliver_localpart = save_deliver_localpart;
1859 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1860 "\"%s\" in %s transport for callout: %s", tf.hosts,
1861 tp->name, expand_string_message);
1866 host_item *host, *nexthost;
1867 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1869 /* Just ignore failures to find a host address. If we don't manage
1870 to find any addresses, the callout will defer. Note that more than
1871 one address may be found for a single host, which will result in
1872 additional host items being inserted into the chain. Hence we must
1873 save the next host first. */
1875 flags = HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
1876 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1877 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1879 for (host = host_list; host; host = nexthost)
1881 nexthost = host->next;
1882 if (tf.gethostbyname ||
1883 string_is_ip_address(host->name, NULL) != 0)
1884 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1887 dnssec_domains * dnssec_domains = NULL;
1888 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1890 smtp_transport_options_block * ob =
1891 (smtp_transport_options_block *) tp->options_block;
1892 dnssec_domains = &ob->dnssec;
1895 (void) host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1896 dnssec_domains, NULL, NULL);
1903 /* Can only do a callout if we have at least one host! If the callout
1904 fails, it will have set ${sender,recipient}_verify_failure. */
1908 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1909 if (host_checking && !host_checking_callout)
1912 debug_printf("... callout omitted by default when host testing\n"
1913 "(Use -bhc if you want the callouts to happen.)\n");
1918 deliver_set_expansions(addr);
1920 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1921 callout_connect, options, se_mailfrom, pm_mailfrom);
1926 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1927 "transport provided a host list\n");
1932 /* Otherwise, any failure is a routing failure */
1934 else *failure_ptr = US"route";
1936 /* A router may return REROUTED if it has set up a child address as a result
1937 of a change of domain name (typically from widening). In this case we always
1938 want to continue to verify the new child. */
1940 if (rc == REROUTED) continue;
1942 /* Handle hard failures */
1949 address_item *p = addr->parent;
1951 respond_printf(f, "%s%s %s", ko_prefix,
1952 full_info ? addr->address : address,
1953 address_test_mode ? "is undeliverable" : "failed to verify");
1954 if (!expn && admin_user)
1956 if (addr->basic_errno > 0)
1957 respond_printf(f, ": %s", strerror(addr->basic_errno));
1959 respond_printf(f, ": %s", addr->message);
1962 /* Show parents iff doing full info */
1964 if (full_info) while (p)
1966 respond_printf(f, "%s\n <-- %s", cr, p->address);
1969 respond_printf(f, "%s\n", cr);
1971 cancel_cutthrough_connection(TRUE, US"routing hard fail");
1975 yield = copy_error(vaddr, addr, FAIL);
1983 else if (rc == DEFER)
1988 address_item *p = addr->parent;
1989 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1990 full_info? addr->address : address);
1991 if (!expn && admin_user)
1993 if (addr->basic_errno > 0)
1994 respond_printf(f, ": %s", strerror(addr->basic_errno));
1996 respond_printf(f, ": %s", addr->message);
1997 else if (addr->basic_errno <= 0)
1998 respond_printf(f, ": unknown error");
2001 /* Show parents iff doing full info */
2003 if (full_info) while (p)
2005 respond_printf(f, "%s\n <-- %s", cr, p->address);
2008 respond_printf(f, "%s\n", cr);
2010 cancel_cutthrough_connection(TRUE, US"routing soft fail");
2014 yield = copy_error(vaddr, addr, DEFER);
2017 if (yield == OK) yield = DEFER;
2020 /* If we are handling EXPN, we do not want to continue to route beyond
2021 the top level (whose address is in "address"). */
2025 uschar *ok_prefix = US"250-";
2028 if (!addr_local && !addr_remote)
2029 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2031 respond_printf(f, "250 <%s>\r\n", address);
2035 address_item *addr2 = addr_new;
2036 addr_new = addr2->next;
2037 if (!addr_new) ok_prefix = US"250 ";
2038 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2044 /* Successful routing other than EXPN. */
2048 /* Handle successful routing when short info wanted. Otherwise continue for
2049 other (generated) addresses. Short info is the operational case. Full info
2050 can be requested only when debug_selector != 0 and a file is supplied.
2052 There is a conflict between the use of aliasing as an alternate email
2053 address, and as a sort of mailing list. If an alias turns the incoming
2054 address into just one address (e.g. J.Caesar->jc44) you may well want to
2055 carry on verifying the generated address to ensure it is valid when
2056 checking incoming mail. If aliasing generates multiple addresses, you
2057 probably don't want to do this. Exim therefore treats the generation of
2058 just a single new address as a special case, and continues on to verify the
2059 generated address. */
2061 if ( !full_info /* Stop if short info wanted AND */
2062 && ( ( !addr_new /* No new address OR */
2063 || addr_new->next /* More than one new address OR */
2064 || testflag(addr_new, af_pfr) /* New address is pfr */
2067 ( addr_new /* At least one new address AND */
2068 && success_on_redirect /* success_on_redirect is set */
2072 if (f) fprintf(f, "%s %s\n",
2073 address, address_test_mode ? "is deliverable" : "verified");
2075 /* If we have carried on to verify a child address, we want the value
2076 of $address_data to be that of the child */
2078 vaddr->prop.address_data = addr->prop.address_data;
2080 /* If stopped because more than one new address, cannot cutthrough */
2082 if (addr_new && addr_new->next)
2083 cancel_cutthrough_connection(TRUE, US"multiple addresses from routing");
2089 } /* Loop for generated addresses */
2091 /* Display the full results of the successful routing, including any generated
2092 addresses. Control gets here only when full_info is set, which requires f not
2093 to be NULL, and this occurs only when a top-level verify is called with the
2094 debugging switch on.
2096 If there are no local and no remote addresses, and there were no pipes, files,
2097 or autoreplies, and there were no errors or deferments, the message is to be
2098 discarded, usually because of the use of :blackhole: in an alias file. */
2100 if (allok && !addr_local && !addr_remote)
2102 fprintf(f, "mail to %s is discarded\n", address);
2106 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2109 address_item *addr = addr_list;
2110 address_item *p = addr->parent;
2111 transport_instance * tp = addr->transport;
2113 addr_list = addr->next;
2115 fprintf(f, "%s", CS addr->address);
2116 #ifdef EXPERIMENTAL_SRS
2117 if(addr->prop.srs_sender)
2118 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2121 /* If the address is a duplicate, show something about it. */
2123 if (!testflag(addr, af_pfr))
2126 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2127 fprintf(f, " [duplicate, would not be delivered]");
2128 else tree_add_duplicate(addr->unique, addr);
2131 /* Now show its parents */
2133 for (p = addr->parent; p; p = p->parent)
2134 fprintf(f, "\n <-- %s", p->address);
2137 /* Show router, and transport */
2139 fprintf(f, "router = %s, transport = %s\n",
2140 addr->router->name, tp ? tp->name : US"unset");
2142 /* Show any hosts that are set up by a router unless the transport
2143 is going to override them; fiddle a bit to get a nice format. */
2145 if (addr->host_list && tp && !tp->overrides_hosts)
2150 for (h = addr->host_list; h; h = h->next)
2151 { /* get max lengths of host names, addrs */
2152 int len = Ustrlen(h->name);
2153 if (len > maxlen) maxlen = len;
2154 len = h->address ? Ustrlen(h->address) : 7;
2155 if (len > maxaddlen) maxaddlen = len;
2157 for (h = addr->host_list; h; h = h->next)
2159 fprintf(f, " host %-*s ", maxlen, h->name);
2162 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2163 else if (tp->info->local)
2164 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2166 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2168 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2169 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2170 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2171 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2177 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2178 the -bv or -bt case). */
2182 tls_modify_variables(&tls_in);
2190 /*************************************************
2191 * Check headers for syntax errors *
2192 *************************************************/
2194 /* This function checks those header lines that contain addresses, and verifies
2195 that all the addresses therein are 5322-syntactially correct.
2198 msgptr where to put an error message
2205 verify_check_headers(uschar **msgptr)
2211 for (h = header_list; h && yield == OK; h = h->next)
2213 if (h->type != htype_from &&
2214 h->type != htype_reply_to &&
2215 h->type != htype_sender &&
2216 h->type != htype_to &&
2217 h->type != htype_cc &&
2218 h->type != htype_bcc)
2221 colon = Ustrchr(h->text, ':');
2223 while (isspace(*s)) s++;
2225 /* Loop for multiple addresses in the header, enabling group syntax. Note
2226 that we have to reset this after the header has been scanned. */
2228 parse_allow_group = TRUE;
2232 uschar *ss = parse_find_address_end(s, FALSE);
2233 uschar *recipient, *errmess;
2234 int terminator = *ss;
2235 int start, end, domain;
2237 /* Temporarily terminate the string at this point, and extract the
2238 operative address within, allowing group syntax. */
2241 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2244 /* Permit an unqualified address only if the message is local, or if the
2245 sending host is configured to be permitted to send them. */
2247 if (recipient && !domain)
2249 if (h->type == htype_from || h->type == htype_sender)
2251 if (!allow_unqualified_sender) recipient = NULL;
2255 if (!allow_unqualified_recipient) recipient = NULL;
2257 if (recipient == NULL) errmess = US"unqualified address not permitted";
2260 /* It's an error if no address could be extracted, except for the special
2261 case of an empty address. */
2263 if (!recipient && Ustrcmp(errmess, "empty address") != 0)
2265 uschar *verb = US"is";
2270 /* Arrange not to include any white space at the end in the
2271 error message or the header name. */
2273 while (t > s && isspace(t[-1])) t--;
2274 while (tt > h->text && isspace(tt[-1])) tt--;
2276 /* Add the address that failed to the error message, since in a
2277 header with very many addresses it is sometimes hard to spot
2278 which one is at fault. However, limit the amount of address to
2279 quote - cases have been seen where, for example, a missing double
2280 quote in a humungous To: header creates an "address" that is longer
2281 than string_sprintf can handle. */
2290 /* deconst cast ok as we're passing a non-const to string_printing() */
2291 *msgptr = US string_printing(
2292 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2293 errmess, (int)(tt - h->text), h->text, verb, len, s));
2296 break; /* Out of address loop */
2299 /* Advance to the next address */
2301 s = ss + (terminator ? 1 : 0);
2302 while (isspace(*s)) s++;
2303 } /* Next address */
2305 parse_allow_group = FALSE;
2306 parse_found_group = FALSE;
2307 } /* Next header unless yield has been set FALSE */
2313 /*************************************************
2314 * Check header names for 8-bit characters *
2315 *************************************************/
2317 /* This function checks for invalid characters in header names. See
2318 RFC 5322, 2.2. and RFC 6532, 3.
2321 msgptr where to put an error message
2328 verify_check_header_names_ascii(uschar **msgptr)
2333 for (h = header_list; h; h = h->next)
2335 colon = Ustrchr(h->text, ':');
2336 for(s = h->text; s < colon; s++)
2337 if ((*s < 33) || (*s > 126))
2339 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2340 colon - h->text, h->text);
2347 /*************************************************
2348 * Check for blind recipients *
2349 *************************************************/
2351 /* This function checks that every (envelope) recipient is mentioned in either
2352 the To: or Cc: header lines, thus detecting blind carbon copies.
2354 There are two ways of scanning that could be used: either scan the header lines
2355 and tick off the recipients, or scan the recipients and check the header lines.
2356 The original proposed patch did the former, but I have chosen to do the latter,
2357 because (a) it requires no memory and (b) will use fewer resources when there
2358 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2361 Returns: OK if there are no blind recipients
2362 FAIL if there is at least one blind recipient
2366 verify_check_notblind(void)
2369 for (i = 0; i < recipients_count; i++)
2373 uschar *address = recipients_list[i].address;
2375 for (h = header_list; !found && h != NULL; h = h->next)
2379 if (h->type != htype_to && h->type != htype_cc) continue;
2381 colon = Ustrchr(h->text, ':');
2383 while (isspace(*s)) s++;
2385 /* Loop for multiple addresses in the header, enabling group syntax. Note
2386 that we have to reset this after the header has been scanned. */
2388 parse_allow_group = TRUE;
2392 uschar *ss = parse_find_address_end(s, FALSE);
2393 uschar *recipient,*errmess;
2394 int terminator = *ss;
2395 int start, end, domain;
2397 /* Temporarily terminate the string at this point, and extract the
2398 operative address within, allowing group syntax. */
2401 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2404 /* If we found a valid recipient that has a domain, compare it with the
2405 envelope recipient. Local parts are compared case-sensitively, domains
2406 case-insensitively. By comparing from the start with length "domain", we
2407 include the "@" at the end, which ensures that we are comparing the whole
2408 local part of each address. */
2410 if (recipient != NULL && domain != 0)
2412 found = Ustrncmp(recipient, address, domain) == 0 &&
2413 strcmpic(recipient + domain, address + domain) == 0;
2417 /* Advance to the next address */
2419 s = ss + (terminator? 1:0);
2420 while (isspace(*s)) s++;
2421 } /* Next address */
2423 parse_allow_group = FALSE;
2424 parse_found_group = FALSE;
2425 } /* Next header (if found is false) */
2427 if (!found) return FAIL;
2428 } /* Next recipient */
2435 /*************************************************
2436 * Find if verified sender *
2437 *************************************************/
2439 /* Usually, just a single address is verified as the sender of the message.
2440 However, Exim can be made to verify other addresses as well (often related in
2441 some way), and this is useful in some environments. There may therefore be a
2442 chain of such addresses that have previously been tested. This function finds
2443 whether a given address is on the chain.
2445 Arguments: the address to be verified
2446 Returns: pointer to an address item, or NULL
2450 verify_checked_sender(uschar *sender)
2453 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2454 if (Ustrcmp(sender, addr->address) == 0) break;
2462 /*************************************************
2463 * Get valid header address *
2464 *************************************************/
2466 /* Scan the originator headers of the message, looking for an address that
2467 verifies successfully. RFC 822 says:
2469 o The "Sender" field mailbox should be sent notices of
2470 any problems in transport or delivery of the original
2471 messages. If there is no "Sender" field, then the
2472 "From" field mailbox should be used.
2474 o If the "Reply-To" field exists, then the reply should
2475 go to the addresses indicated in that field and not to
2476 the address(es) indicated in the "From" field.
2478 So we check a Sender field if there is one, else a Reply_to field, else a From
2479 field. As some strange messages may have more than one of these fields,
2480 especially if they are resent- fields, check all of them if there is more than
2484 user_msgptr points to where to put a user error message
2485 log_msgptr points to where to put a log error message
2486 callout timeout for callout check (passed to verify_address())
2487 callout_overall overall callout timeout (ditto)
2488 callout_connect connect callout timeout (ditto)
2489 se_mailfrom mailfrom for verify; NULL => ""
2490 pm_mailfrom sender for pm callout check (passed to verify_address())
2491 options callout options (passed to verify_address())
2492 verrno where to put the address basic_errno
2494 If log_msgptr is set to something without setting user_msgptr, the caller
2495 normally uses log_msgptr for both things.
2497 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2498 FAIL is given if no appropriate headers are found
2502 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2503 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2504 uschar *pm_mailfrom, int options, int *verrno)
2506 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2511 for (i = 0; i < 3 && !done; i++)
2514 for (h = header_list; h != NULL && !done; h = h->next)
2516 int terminator, new_ok;
2517 uschar *s, *ss, *endname;
2519 if (h->type != header_types[i]) continue;
2520 s = endname = Ustrchr(h->text, ':') + 1;
2522 /* Scan the addresses in the header, enabling group syntax. Note that we
2523 have to reset this after the header has been scanned. */
2525 parse_allow_group = TRUE;
2529 address_item *vaddr;
2531 while (isspace(*s) || *s == ',') s++;
2532 if (*s == 0) break; /* End of header */
2534 ss = parse_find_address_end(s, FALSE);
2536 /* The terminator is a comma or end of header, but there may be white
2537 space preceding it (including newline for the last address). Move back
2538 past any white space so we can check against any cached envelope sender
2539 address verifications. */
2541 while (isspace(ss[-1])) ss--;
2545 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2546 (int)(endname - h->text), h->text, s);
2548 /* See if we have already verified this address as an envelope sender,
2549 and if so, use the previous answer. */
2551 vaddr = verify_checked_sender(s);
2553 if (vaddr != NULL && /* Previously checked */
2554 (callout <= 0 || /* No callout needed; OR */
2555 vaddr->special_action > 256)) /* Callout was done */
2557 new_ok = vaddr->special_action & 255;
2558 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2559 *ss = terminator; /* Restore shortened string */
2562 /* Otherwise we run the verification now. We must restore the shortened
2563 string before running the verification, so the headers are correct, in
2564 case there is any rewriting. */
2568 int start, end, domain;
2569 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2574 /* If we found an empty address, just carry on with the next one, but
2575 kill the message. */
2577 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2584 /* If verification failed because of a syntax error, fail this
2585 function, and ensure that the failing address gets added to the error
2588 if (address == NULL)
2591 while (ss > s && isspace(ss[-1])) ss--;
2592 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2593 "scanning for sender: %s in \"%.*s\"",
2594 (int)(endname - h->text), h->text, *log_msgptr, (int)(ss - s), s);
2600 /* Else go ahead with the sender verification. But it isn't *the*
2601 sender of the message, so set vopt_fake_sender to stop sender_address
2602 being replaced after rewriting or qualification. */
2606 vaddr = deliver_make_addr(address, FALSE);
2607 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2608 callout, callout_overall, callout_connect, se_mailfrom,
2613 /* We now have the result, either newly found, or cached. If we are
2614 giving out error details, set a specific user error. This means that the
2615 last of these will be returned to the user if all three fail. We do not
2616 set a log message - the generic one below will be used. */
2620 *verrno = vaddr->basic_errno;
2621 if (smtp_return_error_details)
2622 *user_msgptr = string_sprintf("Rejected after DATA: "
2623 "could not verify \"%.*s\" header address\n%s: %s",
2624 (int)(endname - h->text), h->text, vaddr->address, vaddr->message);
2627 /* Success or defer */
2636 if (new_ok == DEFER) yield = DEFER;
2638 /* Move on to any more addresses in the header */
2641 } /* Next address */
2643 parse_allow_group = FALSE;
2644 parse_found_group = FALSE;
2645 } /* Next header, unless done */
2646 } /* Next header type unless done */
2648 if (yield == FAIL && *log_msgptr == NULL)
2649 *log_msgptr = US"there is no valid sender in any header line";
2651 if (yield == DEFER && *log_msgptr == NULL)
2652 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2660 /*************************************************
2661 * Get RFC 1413 identification *
2662 *************************************************/
2664 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2665 the timeout is set to zero, then the query is not done. There may also be lists
2666 of hosts and nets which are exempt. To guard against malefactors sending
2667 non-printing characters which could, for example, disrupt a message's headers,
2668 make sure the string consists of printing characters only.
2671 port the port to connect to; usually this is IDENT_PORT (113), but when
2672 running in the test harness with -bh a different value is used.
2676 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2680 verify_get_ident(int port)
2682 int sock, host_af, qlen;
2683 int received_sender_port, received_interface_port, n;
2686 uschar buffer[2048];
2688 /* Default is no ident. Check whether we want to do an ident check for this
2691 sender_ident = NULL;
2692 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2695 DEBUG(D_ident) debug_printf("doing ident callback\n");
2697 /* Set up a connection to the ident port of the remote host. Bind the local end
2698 to the incoming interface address. If the sender host address is an IPv6
2699 address, the incoming interface address will also be IPv6. */
2701 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2702 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2704 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2706 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2711 /* Construct and send the query. */
2713 qlen = snprintf(CS buffer, sizeof(buffer), "%d , %d\r\n",
2714 sender_host_port, interface_port);
2715 early_data.data = buffer;
2716 early_data.len = qlen;
2718 if (ip_connect(sock, host_af, sender_host_address, port,
2719 rfc1413_query_timeout, &early_data) < 0)
2721 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2722 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2723 sender_host_address);
2725 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2726 sender_host_address, strerror(errno));
2730 /* Read a response line. We put it into the rest of the buffer, using several
2731 recv() calls if necessary. */
2739 int size = sizeof(buffer) - (p - buffer);
2741 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2742 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2743 if (count <= 0) goto END_OFF; /* Read error or EOF */
2745 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2746 generous, and accept a plain \n terminator as well. The only illegal
2749 for (pp = p; pp < p + count; pp++)
2751 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2754 if (pp[-1] == '\r') pp--;
2756 goto GOT_DATA; /* Break out of both loops */
2760 /* Reached the end of the data without finding \n. Let the loop continue to
2761 read some more, if there is room. */
2768 /* We have received a line of data. Check it carefully. It must start with the
2769 same two port numbers that we sent, followed by data as defined by the RFC. For
2772 12345 , 25 : USERID : UNIX :root
2774 However, the amount of white space may be different to what we sent. In the
2775 "osname" field there may be several sub-fields, comma separated. The data we
2776 actually want to save follows the third colon. Some systems put leading spaces
2777 in it - we discard those. */
2779 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2780 &received_interface_port, &n) != 2 ||
2781 received_sender_port != sender_host_port ||
2782 received_interface_port != interface_port)
2785 p = buffer + qlen + n;
2786 while(isspace(*p)) p++;
2787 if (*p++ != ':') goto END_OFF;
2788 while(isspace(*p)) p++;
2789 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2791 while(isspace(*p)) p++;
2792 if (*p++ != ':') goto END_OFF;
2793 while (*p != 0 && *p != ':') p++;
2794 if (*p++ == 0) goto END_OFF;
2795 while(isspace(*p)) p++;
2796 if (*p == 0) goto END_OFF;
2798 /* The rest of the line is the data we want. We turn it into printing
2799 characters when we save it, so that it cannot mess up the format of any logging
2800 or Received: lines into which it gets inserted. We keep a maximum of 127
2801 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2803 sender_ident = US string_printing(string_copyn(p, 127));
2804 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2814 /*************************************************
2815 * Match host to a single host-list item *
2816 *************************************************/
2818 /* This function compares a host (name or address) against a single item
2819 from a host list. The host name gets looked up if it is needed and is not
2820 already known. The function is called from verify_check_this_host() via
2821 match_check_list(), which is why most of its arguments are in a single block.
2824 arg the argument block (see below)
2825 ss the host-list item
2826 valueptr where to pass back looked up data, or NULL
2827 error for error message when returning ERROR
2830 host_name (a) the host name, or
2831 (b) NULL, implying use sender_host_name and
2832 sender_host_aliases, looking them up if required, or
2833 (c) the empty string, meaning that only IP address matches
2835 host_address the host address
2836 host_ipv4 the IPv4 address taken from an IPv6 one
2840 DEFER lookup deferred
2841 ERROR (a) failed to find the host name or IP address, or
2842 (b) unknown lookup type specified, or
2843 (c) host name encountered when only IP addresses are
2848 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2850 check_host_block *cb = (check_host_block *)arg;
2853 BOOL iplookup = FALSE;
2854 BOOL isquery = FALSE;
2855 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2860 /* Optimize for the special case when the pattern is "*". */
2862 if (*ss == '*' && ss[1] == 0) return OK;
2864 /* If the pattern is empty, it matches only in the case when there is no host -
2865 this can occur in ACL checking for SMTP input using the -bs option. In this
2866 situation, the host address is the empty string. */
2868 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2869 if (*ss == 0) return FAIL;
2871 /* If the pattern is precisely "@" then match against the primary host name,
2872 provided that host name matching is permitted; if it's "@[]" match against the
2873 local host's IP addresses. */
2879 if (isiponly) return ERROR;
2880 ss = primary_hostname;
2882 else if (Ustrcmp(ss, "@[]") == 0)
2884 ip_address_item *ip;
2885 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2886 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2891 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2892 a (possibly masked) comparison with the current IP address. */
2894 if (string_is_ip_address(ss, &maskoffset) != 0)
2895 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2897 /* The pattern is not an IP address. A common error that people make is to omit
2898 one component of an IPv4 address, either by accident, or believing that, for
2899 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,
2900 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2901 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2902 ancient specification.) To aid in debugging these cases, we give a specific
2903 error if the pattern contains only digits and dots or contains a slash preceded
2904 only by digits and dots (a slash at the start indicates a file name and of
2905 course slashes may be present in lookups, but not preceded only by digits and
2908 for (t = ss; isdigit(*t) || *t == '.'; t++);
2909 if (*t == 0 || (*t == '/' && t != ss))
2911 *error = US"malformed IPv4 address or address mask";
2915 /* See if there is a semicolon in the pattern */
2917 semicolon = Ustrchr(ss, ';');
2919 /* If we are doing an IP address only match, then all lookups must be IP
2920 address lookups, even if there is no "net-". */
2924 iplookup = semicolon != NULL;
2927 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2928 a lookup on a masked IP network, in textual form. We obey this code even if we
2929 have already set iplookup, so as to skip over the "net-" prefix and to set the
2930 mask length. The net- stuff really only applies to single-key lookups where the
2931 key is implicit. For query-style lookups the key is specified in the query.
2932 From release 4.30, the use of net- for query style is no longer needed, but we
2933 retain it for backward compatibility. */
2935 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2938 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2939 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2940 iplookup = (*t++ == '-');
2944 /* Do the IP address lookup if that is indeed what we have */
2952 uschar *filename, *key, *result;
2955 /* Find the search type */
2957 search_type = search_findtype(t, semicolon - t);
2959 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2960 search_error_message);
2962 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2963 is no file name, and the "key" is just the query. For query-style with a file
2964 name, we have to fish the file off the start of the query. For a single-key
2965 lookup, the key is the current IP address, masked appropriately, and
2966 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2967 dot separators instead of colons, except when the lookup type is "iplsearch".
2970 if (mac_islookup(search_type, lookup_absfilequery))
2972 filename = semicolon + 1;
2974 while (*key != 0 && !isspace(*key)) key++;
2975 filename = string_copyn(filename, key - filename);
2976 while (isspace(*key)) key++;
2978 else if (mac_islookup(search_type, lookup_querystyle))
2981 key = semicolon + 1;
2983 else /* Single-key style */
2985 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2987 insize = host_aton(cb->host_address, incoming);
2988 host_mask(insize, incoming, mlen);
2989 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2991 filename = semicolon + 1;
2994 /* Now do the actual lookup; note that there is no search_close() because
2995 of the caching arrangements. */
2997 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2998 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
3000 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3001 if (valueptr != NULL) *valueptr = result;
3002 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3005 /* The pattern is not an IP address or network reference of any kind. That is,
3006 it is a host name pattern. If this is an IP only match, there's an error in the
3011 *error = US"cannot match host name in match_ip list";
3015 /* Check the characters of the pattern to see if they comprise only letters,
3016 digits, full stops, and hyphens (the constituents of domain names). Allow
3017 underscores, as they are all too commonly found. Sigh. Also, if
3018 allow_utf8_domains is set, allow top-bit characters. */
3020 for (t = ss; *t != 0; t++)
3021 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3022 (!allow_utf8_domains || *t < 128)) break;
3024 /* If the pattern is a complete domain name, with no fancy characters, look up
3025 its IP address and match against that. Note that a multi-homed host will add
3026 items to the chain. */
3037 /* Using byname rather than bydns here means we cannot determine dnssec
3038 status. On the other hand it is unclear how that could be either
3039 propagated up or enforced. */
3041 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3042 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3045 for (hh = &h; hh != NULL; hh = hh->next)
3047 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3051 if (rc == HOST_FIND_AGAIN) return DEFER;
3052 *error = string_sprintf("failed to find IP address for %s", ss);
3056 /* Almost all subsequent comparisons require the host name, and can be done
3057 using the general string matching function. When this function is called for
3058 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3059 must use sender_host_name and its aliases, looking them up if necessary. */
3061 if (cb->host_name != NULL) /* Explicit host name given */
3062 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3065 /* Host name not given; in principle we need the sender host name and its
3066 aliases. However, for query-style lookups, we do not need the name if the
3067 query does not contain $sender_host_name. From release 4.23, a reference to
3068 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3071 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3073 const uschar *affix;
3074 int partial, affixlen, starflags, id;
3077 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3080 if (id < 0) /* Unknown lookup type */
3082 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3083 search_error_message, ss);
3086 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3091 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3094 case DEFER: return DEFER;
3095 default: return FAIL;
3099 /* Not a query-style lookup; must ensure the host name is present, and then we
3100 do a check on the name and all its aliases. */
3102 if (!sender_host_name)
3104 HDEBUG(D_host_lookup)
3105 debug_printf("sender host name required, to match against %s\n", ss);
3106 if (host_lookup_failed || host_name_lookup() != OK)
3108 *error = string_sprintf("failed to find host name for %s",
3109 sender_host_address);;
3112 host_build_sender_fullhost();
3115 /* Match on the sender host name, using the general matching function */
3117 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE, valueptr))
3120 case DEFER: return DEFER;
3123 /* If there are aliases, try matching on them. */
3125 aliases = sender_host_aliases;
3127 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3130 case DEFER: return DEFER;
3138 /*************************************************
3139 * Check a specific host matches a host list *
3140 *************************************************/
3142 /* This function is passed a host list containing items in a number of
3143 different formats and the identity of a host. Its job is to determine whether
3144 the given host is in the set of hosts defined by the list. The host name is
3145 passed as a pointer so that it can be looked up if needed and not already
3146 known. This is commonly the case when called from verify_check_host() to check
3147 an incoming connection. When called from elsewhere the host name should usually
3150 This function is now just a front end to match_check_list(), which runs common
3151 code for scanning a list. We pass it the check_host() function to perform a
3155 listptr pointer to the host list
3156 cache_bits pointer to cache for named lists, or NULL
3157 host_name the host name or NULL, implying use sender_host_name and
3158 sender_host_aliases, looking them up if required
3159 host_address the IP address
3160 valueptr if not NULL, data from a lookup is passed back here
3162 Returns: OK if the host is in the defined set
3163 FAIL if the host is not in the defined set,
3164 DEFER if a data lookup deferred (not a host lookup)
3166 If the host name was needed in order to make a comparison, and could not be
3167 determined from the IP address, the result is FAIL unless the item
3168 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3171 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3172 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3175 unsigned int *local_cache_bits = cache_bits;
3176 const uschar *save_host_address = deliver_host_address;
3177 check_host_block cb = { .host_name = host_name, .host_address = host_address };
3179 if (valueptr) *valueptr = NULL;
3181 /* If the host address starts off ::ffff: it is an IPv6 address in
3182 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3185 cb.host_ipv4 = Ustrncmp(host_address, "::ffff:", 7) == 0
3186 ? host_address + 7 : host_address;
3188 /* During the running of the check, put the IP address into $host_address. In
3189 the case of calls from the smtp transport, it will already be there. However,
3190 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3191 the safe side, any existing setting is preserved, though as I write this
3192 (November 2004) I can't see any cases where it is actually needed. */
3194 deliver_host_address = host_address;
3195 rc = match_check_list(
3196 listptr, /* the list */
3197 0, /* separator character */
3198 &hostlist_anchor, /* anchor pointer */
3199 &local_cache_bits, /* cache pointer */
3200 check_host, /* function for testing */
3201 &cb, /* argument for function */
3202 MCL_HOST, /* type of check */
3203 (host_address == sender_host_address)?
3204 US"host" : host_address, /* text for debugging */
3205 valueptr); /* where to pass back data */
3206 deliver_host_address = save_host_address;
3213 /*************************************************
3214 * Check the given host item matches a list *
3215 *************************************************/
3217 verify_check_given_host(uschar **listptr, host_item *host)
3219 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3222 /*************************************************
3223 * Check the remote host matches a list *
3224 *************************************************/
3226 /* This is a front end to verify_check_this_host(), created because checking
3227 the remote host is a common occurrence. With luck, a good compiler will spot
3228 the tail recursion and optimize it. If there's no host address, this is
3229 command-line SMTP input - check against an empty string for the address.
3232 listptr pointer to the host list
3234 Returns: the yield of verify_check_this_host(),
3235 i.e. OK, FAIL, or DEFER
3239 verify_check_host(uschar **listptr)
3241 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3242 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3249 /*************************************************
3250 * Invert an IP address *
3251 *************************************************/
3253 /* Originally just used for DNS xBL lists, now also used for the
3254 reverse_ip expansion operator.
3257 buffer where to put the answer
3258 address the address to invert
3262 invert_address(uschar *buffer, uschar *address)
3265 uschar *bptr = buffer;
3267 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3268 to the IPv4 part only. */
3270 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3272 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3275 if (host_aton(address, bin) == 1)
3279 for (i = 0; i < 4; i++)
3281 sprintf(CS bptr, "%d.", x & 255);
3282 while (*bptr) bptr++;
3287 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3288 in any DNS black lists, and the format in which they will be looked up is
3289 unknown. This is just a guess. */
3295 for (j = 3; j >= 0; j--)
3298 for (i = 0; i < 8; i++)
3300 sprintf(CS bptr, "%x.", x & 15);
3301 while (*bptr) bptr++;
3308 /* Remove trailing period -- this is needed so that both arbitrary
3309 dnsbl keydomains and inverted addresses may be combined with the
3310 same format string, "%s.%s" */
3317 /*************************************************
3318 * Perform a single dnsbl lookup *
3319 *************************************************/
3321 /* This function is called from verify_check_dnsbl() below. It is also called
3322 recursively from within itself when domain and domain_txt are different
3323 pointers, in order to get the TXT record from the alternate domain.
3326 domain the outer dnsbl domain
3327 domain_txt alternate domain to lookup TXT record on success; when the
3328 same domain is to be used, domain_txt == domain (that is,
3329 the pointers must be identical, not just the text)
3330 keydomain the current keydomain (for debug message)
3331 prepend subdomain to lookup (like keydomain, but
3332 reversed if IP address)
3333 iplist the list of matching IP addresses, or NULL for "any"
3334 bitmask true if bitmask matching is wanted
3335 match_type condition for 'succeed' result
3336 0 => Any RR in iplist (=)
3337 1 => No RR in iplist (!=)
3338 2 => All RRs in iplist (==)
3339 3 => Some RRs not in iplist (!==)
3340 the two bits are defined as MT_NOT and MT_ALL
3341 defer_return what to return for a defer
3343 Returns: OK if lookup succeeded
3348 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3349 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3355 dnsbl_cache_block *cb;
3356 int old_pool = store_pool;
3357 uschar query[256]; /* DNS domain max length */
3359 /* Construct the specific query domainname */
3361 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3363 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3364 "(ignored): %s...", query);
3368 /* Look for this query in the cache. */
3370 if ( (t = tree_search(dnsbl_cache, query))
3371 && (cb = t->data.ptr)->expiry > time(NULL)
3374 /* Previous lookup was cached */
3377 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3380 /* If not cached from a previous lookup, we must do a DNS lookup, and
3381 cache the result in permanent memory. */
3387 store_pool = POOL_PERM;
3391 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3395 { /* Set up a tree entry to cache the lookup */
3396 t = store_get(sizeof(tree_node) + Ustrlen(query));
3397 Ustrcpy(t->name, query);
3398 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3399 (void)tree_insertnode(&dnsbl_cache, t);
3402 /* Do the DNS lookup . */
3404 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3405 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3406 cb->text_set = FALSE;
3410 /* If the lookup succeeded, cache the RHS address. The code allows for
3411 more than one address - this was for complete generality and the possible
3412 use of A6 records. However, A6 records have been reduced to experimental
3413 status (August 2001) and may die out. So they may never get used at all,
3414 let alone in dnsbl records. However, leave the code here, just in case.
3416 Quite apart from one A6 RR generating multiple addresses, there are DNS
3417 lists that return more than one A record, so we must handle multiple
3418 addresses generated in that way as well.
3420 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3421 or some suitably far-future time if none were found. */
3423 if (cb->rc == DNS_SUCCEED)
3426 dns_address **addrp = &(cb->rhs);
3427 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3429 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3430 if (rr->type == T_A)
3432 dns_address *da = dns_address_from_rr(&dnsa, rr);
3436 while (da->next) da = da->next;
3438 if (ttl > rr->ttl) ttl = rr->ttl;
3442 /* If we didn't find any A records, change the return code. This can
3443 happen when there is a CNAME record but there are no A records for what
3446 if (!cb->rhs) cb->rc = DNS_NODATA;
3449 cb->expiry = time(NULL)+ttl;
3450 store_pool = old_pool;
3453 /* We now have the result of the DNS lookup, either newly done, or cached
3454 from a previous call. If the lookup succeeded, check against the address
3455 list if there is one. This may be a positive equality list (introduced by
3456 "="), a negative equality list (introduced by "!="), a positive bitmask
3457 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3459 if (cb->rc == DNS_SUCCEED)
3461 dns_address *da = NULL;
3462 uschar *addlist = cb->rhs->address;
3464 /* For A and AAAA records, there may be multiple addresses from multiple
3465 records. For A6 records (currently not expected to be used) there may be
3466 multiple addresses from a single record. */
3468 for (da = cb->rhs->next; da; da = da->next)
3469 addlist = string_sprintf("%s, %s", addlist, da->address);
3471 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3474 /* Address list check; this can be either for equality, or via a bitmask.
3475 In the latter case, all the bits must match. */
3479 for (da = cb->rhs; da; da = da->next)
3483 const uschar *ptr = iplist;
3486 /* Handle exact matching */
3490 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))))
3491 if (Ustrcmp(CS da->address, ip) == 0)
3495 /* Handle bitmask matching */
3502 /* At present, all known DNS blocking lists use A records, with
3503 IPv4 addresses on the RHS encoding the information they return. I
3504 wonder if this will linger on as the last vestige of IPv4 when IPv6
3505 is ubiquitous? Anyway, for now we use paranoia code to completely
3506 ignore IPv6 addresses. The default mask is 0, which always matches.
3507 We change this only for IPv4 addresses in the list. */
3509 if (host_aton(da->address, address) == 1) mask = address[0];
3511 /* Scan the returned addresses, skipping any that are IPv6 */
3513 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))))
3515 if (host_aton(ip, address) != 1) continue;
3516 if ((address[0] & mask) == address[0]) break;
3522 (a) An IP address in an any ('=') list matched, or
3523 (b) No IP address in an all ('==') list matched
3525 then we're done searching. */
3527 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3530 /* If da == NULL, either
3532 (a) No IP address in an any ('=') list matched, or
3533 (b) An IP address in an all ('==') list didn't match
3535 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3538 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3546 res = US"was no match"; break;
3548 res = US"was an exclude match"; break;
3550 res = US"was an IP address that did not match"; break;
3552 res = US"were no IP addresses that did not match"; break;
3554 debug_printf("=> but we are not accepting this block class because\n");
3555 debug_printf("=> there %s for %s%c%s\n",
3557 ((match_type & MT_ALL) == 0)? "" : "=",
3558 bitmask? '&' : '=', iplist);
3564 /* Either there was no IP list, or the record matched, implying that the
3565 domain is on the list. We now want to find a corresponding TXT record. If an
3566 alternate domain is specified for the TXT record, call this function
3567 recursively to look that up; this has the side effect of re-checking that
3568 there is indeed an A record at the alternate domain. */
3570 if (domain_txt != domain)
3571 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3572 FALSE, match_type, defer_return);
3574 /* If there is no alternate domain, look up a TXT record in the main domain
3575 if it has not previously been cached. */
3579 cb->text_set = TRUE;
3580 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3583 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3585 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3586 if (rr->type == T_TXT) break;
3589 int len = (rr->data)[0];
3590 if (len > 511) len = 127;
3591 store_pool = POOL_PERM;
3592 cb->text = string_sprintf("%.*s", len, CUS (rr->data+1));
3593 store_pool = old_pool;
3598 dnslist_value = addlist;
3599 dnslist_text = cb->text;
3603 /* There was a problem with the DNS lookup */
3605 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3607 log_write(L_dnslist_defer, LOG_MAIN,
3608 "DNS list lookup defer (probably timeout) for %s: %s", query,
3609 (defer_return == OK)? US"assumed in list" :
3610 (defer_return == FAIL)? US"assumed not in list" :
3611 US"returned DEFER");
3612 return defer_return;
3615 /* No entry was found in the DNS; continue for next domain */
3619 debug_printf("DNS lookup for %s failed\n", query);
3620 debug_printf("=> that means %s is not listed at %s\n",
3630 /*************************************************
3631 * Check host against DNS black lists *
3632 *************************************************/
3634 /* This function runs checks against a list of DNS black lists, until one
3635 matches. Each item on the list can be of the form
3637 domain=ip-address/key
3639 The domain is the right-most domain that is used for the query, for example,
3640 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3641 if the DNS lookup returns a matching IP address. Several addresses may be
3642 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3644 If no key is given, what is looked up in the domain is the inverted IP address
3645 of the current client host. If a key is given, it is used to construct the
3646 domain for the lookup. For example:
3648 dsn.rfc-ignorant.org/$sender_address_domain
3650 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3651 then we check for a TXT record for an error message, and if found, save its
3652 value in $dnslist_text. We also cache everything in a tree, to optimize
3655 The TXT record is normally looked up in the same domain as the A record, but
3656 when many lists are combined in a single DNS domain, this will not be a very
3657 specific message. It is possible to specify a different domain for looking up
3658 TXT records; this is given before the main domain, comma-separated. For
3661 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3662 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3664 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3666 Note: an address for testing RBL is 192.203.178.39
3667 Note: an address for testing DUL is 192.203.178.4
3668 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3672 listptr the domain/address/data list
3673 log_msgptr log message on error
3675 Returns: OK successful lookup (i.e. the address is on the list), or
3676 lookup deferred after +include_unknown
3677 FAIL name not found, or no data found for the given type, or
3678 lookup deferred after +exclude_unknown (default)
3679 DEFER lookup failure, if +defer_unknown was set
3683 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3686 int defer_return = FAIL;
3687 const uschar *list = *listptr;
3690 uschar buffer[1024];
3691 uschar revadd[128]; /* Long enough for IPv6 address */
3693 /* Indicate that the inverted IP address is not yet set up */
3697 /* In case this is the first time the DNS resolver is being used. */
3699 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3701 /* Loop through all the domains supplied, until something matches */
3703 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3706 BOOL bitmask = FALSE;
3713 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3715 /* Deal with special values that change the behaviour on defer */
3717 if (domain[0] == '+')
3719 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3720 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3721 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3723 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3728 /* See if there's explicit data to be looked up */
3730 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3732 /* See if there's a list of addresses supplied after the domain name. This is
3733 introduced by an = or a & character; if preceded by = we require all matches
3734 and if preceded by ! we invert the result. */
3736 if (!(iplist = Ustrchr(domain, '=')))
3739 iplist = Ustrchr(domain, '&');
3742 if (iplist) /* Found either = or & */
3744 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3746 match_type |= MT_NOT;
3750 *iplist++ = 0; /* Terminate domain, move on */
3752 /* If we found = (bitmask == FALSE), check for == or =& */
3754 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3756 bitmask = *iplist++ == '&';
3757 match_type |= MT_ALL;
3762 /* If there is a comma in the domain, it indicates that a second domain for
3763 looking up TXT records is provided, before the main domain. Otherwise we must
3764 set domain_txt == domain. */
3766 domain_txt = domain;
3767 comma = Ustrchr(domain, ',');
3774 /* Check that what we have left is a sensible domain name. There is no reason
3775 why these domains should in fact use the same syntax as hosts and email
3776 domains, but in practice they seem to. However, there is little point in
3777 actually causing an error here, because that would no doubt hold up incoming
3778 mail. Instead, I'll just log it. */
3780 for (s = domain; *s != 0; s++)
3782 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3784 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3785 "strange characters - is this right?", domain);
3790 /* Check the alternate domain if present */
3792 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3794 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3796 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3797 "strange characters - is this right?", domain_txt);
3802 /* If there is no key string, construct the query by adding the domain name
3803 onto the inverted host address, and perform a single DNS lookup. */
3807 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3809 *log_msgptr = string_sprintf
3810 ("cannot test auto-keyed dnslists condition in %s ACL",
3811 acl_wherenames[where]);
3814 if (sender_host_address == NULL) return FAIL; /* can never match */
3815 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3816 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3817 iplist, bitmask, match_type, defer_return);
3820 dnslist_domain = string_copy(domain_txt);
3821 dnslist_matched = string_copy(sender_host_address);
3822 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3823 sender_host_address, dnslist_domain);
3825 if (rc != FAIL) return rc; /* OK or DEFER */
3828 /* If there is a key string, it can be a list of domains or IP addresses to
3829 be concatenated with the main domain. */
3836 uschar keybuffer[256];
3837 uschar keyrevadd[128];
3839 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3840 sizeof(keybuffer))) != NULL)
3842 uschar *prepend = keydomain;
3844 if (string_is_ip_address(keydomain, NULL) != 0)
3846 invert_address(keyrevadd, keydomain);
3847 prepend = keyrevadd;
3850 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3851 bitmask, match_type, defer_return);
3855 dnslist_domain = string_copy(domain_txt);
3856 dnslist_matched = string_copy(keydomain);
3857 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3858 keydomain, dnslist_domain);
3862 /* If the lookup deferred, remember this fact. We keep trying the rest
3863 of the list to see if we get a useful result, and if we don't, we return
3864 DEFER at the end. */
3866 if (rc == DEFER) defer = TRUE;
3867 } /* continue with next keystring domain/address */
3869 if (defer) return DEFER;
3871 } /* continue with next dnsdb outer domain */
3878 /* End of verify.c */