1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2017 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
21 /* Structure for caching DNSBL lookups */
23 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
42 static uschar cutthrough_response(char, uschar **, int);
46 /*************************************************
47 * Retrieve a callout cache record *
48 *************************************************/
50 /* If a record exists, check whether it has expired.
53 dbm_file an open hints file
55 type "address" or "domain"
56 positive_expire expire time for positive records
57 negative_expire expire time for negative records
59 Returns: the cache record if a non-expired one exists, else NULL
62 static dbdata_callout_cache *
63 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
64 int positive_expire, int negative_expire)
69 dbdata_callout_cache *cache_record;
71 cache_record = dbfn_read_with_length(dbm_file, key, &length);
73 if (cache_record == NULL)
75 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
79 /* We treat a record as "negative" if its result field is not positive, or if
80 it is a domain record and the postmaster field is negative. */
82 negative = cache_record->result != ccache_accept ||
83 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
84 expire = negative? negative_expire : positive_expire;
87 if (now - cache_record->time_stamp > expire)
89 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
93 /* If this is a non-reject domain record, check for the obsolete format version
94 that doesn't have the postmaster and random timestamps, by looking at the
95 length. If so, copy it to a new-style block, replicating the record's
96 timestamp. Then check the additional timestamps. (There's no point wasting
97 effort if connections are rejected.) */
99 if (type[0] == 'd' && cache_record->result != ccache_reject)
101 if (length == sizeof(dbdata_callout_cache_obs))
103 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
104 memcpy(new, cache_record, length);
105 new->postmaster_stamp = new->random_stamp = new->time_stamp;
109 if (now - cache_record->postmaster_stamp > expire)
110 cache_record->postmaster_result = ccache_unknown;
112 if (now - cache_record->random_stamp > expire)
113 cache_record->random_result = ccache_unknown;
116 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
122 /* Check the callout cache.
123 Options * pm_mailfrom may be modified by cache partial results.
125 Return: TRUE if result found
129 cached_callout_lookup(address_item * addr, uschar * address_key,
130 uschar * from_address, int * opt_ptr, uschar ** pm_ptr,
131 int * yield, uschar ** failure_ptr,
132 dbdata_callout_cache * new_domain_record, int * old_domain_res)
134 int options = *opt_ptr;
136 open_db *dbm_file = NULL;
138 /* Open the callout cache database, it it exists, for reading only at this
139 stage, unless caching has been disabled. */
141 if (options & vopt_callout_no_cache)
143 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
145 else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)))
147 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
151 /* If a cache database is available see if we can avoid the need to do an
152 actual callout by making use of previously-obtained data. */
154 dbdata_callout_cache_address * cache_address_record;
155 dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file,
156 addr->domain, US"domain",
157 callout_cache_domain_positive_expire, callout_cache_domain_negative_expire);
159 /* If an unexpired cache record was found for this domain, see if the callout
160 process can be short-circuited. */
164 /* In most cases, if an early command (up to and including MAIL FROM:<>)
165 was rejected, there is no point carrying on. The callout fails. However, if
166 we are doing a recipient verification with use_sender or use_postmaster
167 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
168 will be using a non-empty sender. We have to remember this situation so as
169 not to disturb the cached domain value if this whole verification succeeds
170 (we don't want it turning into "accept"). */
172 *old_domain_res = cache_record->result;
174 if ( cache_record->result == ccache_reject
175 || *from_address == 0 && cache_record->result == ccache_reject_mfnull)
177 setflag(addr, af_verify_nsfail);
179 debug_printf("callout cache: domain gave initial rejection, or "
180 "does not accept HELO or MAIL FROM:<>\n");
181 setflag(addr, af_verify_nsfail);
182 addr->user_message = US"(result of an earlier callout reused).";
184 *failure_ptr = US"mail";
185 dbfn_close(dbm_file);
189 /* If a previous check on a "random" local part was accepted, we assume
190 that the server does not do any checking on local parts. There is therefore
191 no point in doing the callout, because it will always be successful. If a
192 random check previously failed, arrange not to do it again, but preserve
193 the data in the new record. If a random check is required but hasn't been
194 done, skip the remaining cache processing. */
196 if (options & vopt_callout_random) switch(cache_record->random_result)
200 debug_printf("callout cache: domain accepts random addresses\n");
201 dbfn_close(dbm_file);
202 return TRUE; /* Default yield is OK */
206 debug_printf("callout cache: domain rejects random addresses\n");
207 *opt_ptr = options & ~vopt_callout_random;
208 new_domain_record->random_result = ccache_reject;
209 new_domain_record->random_stamp = cache_record->random_stamp;
214 debug_printf("callout cache: need to check random address handling "
215 "(not cached or cache expired)\n");
216 dbfn_close(dbm_file);
220 /* If a postmaster check is requested, but there was a previous failure,
221 there is again no point in carrying on. If a postmaster check is required,
222 but has not been done before, we are going to have to do a callout, so skip
223 remaining cache processing. */
227 if (cache_record->postmaster_result == ccache_reject)
229 setflag(addr, af_verify_pmfail);
231 debug_printf("callout cache: domain does not accept "
232 "RCPT TO:<postmaster@domain>\n");
234 *failure_ptr = US"postmaster";
235 setflag(addr, af_verify_pmfail);
236 addr->user_message = US"(result of earlier verification reused).";
237 dbfn_close(dbm_file);
240 if (cache_record->postmaster_result == ccache_unknown)
243 debug_printf("callout cache: need to check RCPT "
244 "TO:<postmaster@domain> (not cached or cache expired)\n");
245 dbfn_close(dbm_file);
249 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
250 postmaster check if the address itself has to be checked. Also ensure
251 that the value in the cache record is preserved (with its old timestamp).
254 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
255 "TO:<postmaster@domain>\n");
257 new_domain_record->postmaster_result = ccache_accept;
258 new_domain_record->postmaster_stamp = cache_record->postmaster_stamp;
262 /* We can't give a result based on information about the domain. See if there
263 is an unexpired cache record for this specific address (combined with the
264 sender address if we are doing a recipient callout with a non-empty sender).
267 if (!(cache_address_record = (dbdata_callout_cache_address *)
268 get_callout_cache_record(dbm_file, address_key, US"address",
269 callout_cache_positive_expire, callout_cache_negative_expire)))
271 dbfn_close(dbm_file);
275 if (cache_address_record->result == ccache_accept)
278 debug_printf("callout cache: address record is positive\n");
283 debug_printf("callout cache: address record is negative\n");
284 addr->user_message = US"Previous (cached) callout verification failure";
285 *failure_ptr = US"recipient";
289 /* Close the cache database while we actually do the callout for real. */
291 dbfn_close(dbm_file);
298 /* Write results to callout cache
301 cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain,
302 int done, dbdata_callout_cache_address * addr_rec, uschar * address_key)
305 open_db *dbm_file = NULL;
307 /* If we get here with done == TRUE, a successful callout happened, and yield
308 will be set OK or FAIL according to the response to the RCPT command.
309 Otherwise, we looped through the hosts but couldn't complete the business.
310 However, there may be domain-specific information to cache in both cases.
312 The value of the result field in the new_domain record is ccache_unknown if
313 there was an error before or with MAIL FROM:, and errno was not zero,
314 implying some kind of I/O error. We don't want to write the cache in that case.
315 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
317 if (dom_rec->result != ccache_unknown)
318 if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)))
320 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
324 (void)dbfn_write(dbm_file, domain, dom_rec,
325 (int)sizeof(dbdata_callout_cache));
326 HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
327 " result=%d postmaster=%d random=%d\n",
330 dom_rec->postmaster_result,
331 dom_rec->random_result);
334 /* If a definite result was obtained for the callout, cache it unless caching
337 if (done && addr_rec->result != ccache_unknown)
340 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
343 HDEBUG(D_verify) debug_printf("no callout cache available\n");
347 (void)dbfn_write(dbm_file, address_key, addr_rec,
348 (int)sizeof(dbdata_callout_cache_address));
349 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
350 addr_rec->result == ccache_accept ? "positive" : "negative",
355 if (dbm_file) dbfn_close(dbm_file);
359 /* Cutthrough-multi. If the existing cached cutthrough connection matches
360 the one we would make for a subsequent recipient, use it. Send the RCPT TO
361 and check the result, nonpipelined as it may be wanted immediately for
362 recipient-verification.
364 It seems simpler to deal with this case separately from the main callout loop.
365 We will need to remember it has sent, or not, so that rcpt-acl tail code
366 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
368 Return: TRUE for a definitive result for the recipient
371 cutthrough_multi(address_item * addr, host_item * host_list,
372 transport_feedback * tf, int * yield)
377 if (addr->transport == cutthrough.addr.transport)
378 for (host = host_list; host; host = host->next)
379 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
382 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
385 deliver_host = host->name;
386 deliver_host_address = host->address;
387 deliver_host_port = host->port;
388 deliver_domain = addr->domain;
389 transport_name = addr->transport->name;
391 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
393 if (!smtp_get_interface(tf->interface, host_af, addr, &interface,
395 !smtp_get_port(tf->port, addr, &port, US"callout"))
396 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
399 if ( ( interface == cutthrough.interface
401 && cutthrough.interface
402 && Ustrcmp(interface, cutthrough.interface) == 0
404 && port == cutthrough.host.port
407 uschar * resp = NULL;
409 /* Match! Send the RCPT TO, set done from the response */
411 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
412 transport_rcpt_address(addr,
413 addr->transport->rcpt_include_affixes)) >= 0 &&
414 cutthrough_response('2', &resp, CUTTHROUGH_DATA_TIMEOUT) == '2';
416 /* This would go horribly wrong if a callout fail was ignored by ACL.
417 We punt by abandoning cutthrough on a reject, like the
422 address_item * na = store_get(sizeof(address_item));
423 *na = cutthrough.addr;
424 cutthrough.addr = *addr;
425 cutthrough.addr.host_used = &cutthrough.host;
426 cutthrough.addr.next = na;
432 cancel_cutthrough_connection("recipient rejected");
433 if (!resp || errno == ETIMEDOUT)
435 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
440 Ustrcpy(resp, US"connection dropped");
443 string_sprintf("response to \"%s\" was: %s",
444 big_buffer, string_printing(resp));
447 string_sprintf("Callout verification failed:\n%s", resp);
449 /* Hard rejection ends the process */
451 if (resp[0] == '5') /* Address rejected */
459 break; /* host_list */
462 cancel_cutthrough_connection("incompatible connection");
467 /*************************************************
468 * Do callout verification for an address *
469 *************************************************/
471 /* This function is called from verify_address() when the address has routed to
472 a host list, and a callout has been requested. Callouts are expensive; that is
473 why a cache is used to improve the efficiency.
476 addr the address that's been routed
477 host_list the list of hosts to try
478 tf the transport feedback block
480 ifstring "interface" option from transport, or NULL
481 portstring "port" option from transport, or NULL
482 protocolstring "protocol" option from transport, or NULL
483 callout the per-command callout timeout
484 callout_overall the overall callout timeout (if < 0 use 4*callout)
485 callout_connect the callout connection timeout (if < 0 use callout)
486 options the verification options - these bits are used:
487 vopt_is_recipient => this is a recipient address
488 vopt_callout_no_cache => don't use callout cache
489 vopt_callout_fullpm => if postmaster check, do full one
490 vopt_callout_random => do the "random" thing
491 vopt_callout_recipsender => use real sender for recipient
492 vopt_callout_recippmaster => use postmaster for recipient
493 se_mailfrom MAIL FROM address for sender verify; NULL => ""
494 pm_mailfrom if non-NULL, do the postmaster check with this sender
496 Returns: OK/FAIL/DEFER
500 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
501 int callout, int callout_overall, int callout_connect, int options,
502 uschar *se_mailfrom, uschar *pm_mailfrom)
505 int old_domain_cache_result = ccache_accept;
508 uschar *from_address;
509 uschar *random_local_part = NULL;
510 const uschar *save_deliver_domain = deliver_domain;
511 uschar **failure_ptr = options & vopt_is_recipient
512 ? &recipient_verify_failure : &sender_verify_failure;
513 dbdata_callout_cache new_domain_record;
514 dbdata_callout_cache_address new_address_record;
515 time_t callout_start_time;
517 new_domain_record.result = ccache_unknown;
518 new_domain_record.postmaster_result = ccache_unknown;
519 new_domain_record.random_result = ccache_unknown;
521 memset(&new_address_record, 0, sizeof(new_address_record));
523 /* For a recipient callout, the key used for the address cache record must
524 include the sender address if we are using the real sender in the callout,
525 because that may influence the result of the callout. */
527 if (options & vopt_is_recipient)
528 if (options & vopt_callout_recipsender)
530 from_address = sender_address;
531 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
532 if (cutthrough.delivery) options |= vopt_callout_no_cache;
534 else if (options & vopt_callout_recippmaster)
536 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
537 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
538 qualify_domain_sender);
543 address_key = addr->address;
546 /* For a sender callout, we must adjust the key if the mailfrom address is not
551 from_address = se_mailfrom ? se_mailfrom : US"";
552 address_key = *from_address
553 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
556 if (cached_callout_lookup(addr, address_key, from_address,
557 &options, &pm_mailfrom, &yield, failure_ptr,
558 &new_domain_record, &old_domain_cache_result))
561 if (!addr->transport)
563 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
565 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
566 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
567 addr->transport->name, addr->transport->driver_name);
570 smtp_transport_options_block *ob =
571 (smtp_transport_options_block *)addr->transport->options_block;
574 /* The information wasn't available in the cache, so we have to do a real
575 callout and save the result in the cache for next time, unless no_cache is set,
576 or unless we have a previously cached negative random result. If we are to test
577 with a random local part, ensure that such a local part is available. If not,
578 log the fact, but carry on without randomising. */
580 if (options & vopt_callout_random && callout_random_local_part)
581 if (!(random_local_part = expand_string(callout_random_local_part)))
582 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
583 "callout_random_local_part: %s", expand_string_message);
585 /* Default the connect and overall callout timeouts if not set, and record the
586 time we are starting so that we can enforce it. */
588 if (callout_overall < 0) callout_overall = 4 * callout;
589 if (callout_connect < 0) callout_connect = callout;
590 callout_start_time = time(NULL);
592 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
593 output because a callout might take some time. When PIPELINING is active and
594 there are many recipients, the total time for doing lots of callouts can add up
595 and cause the client to time out. So in this case we forgo the PIPELINING
598 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
600 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
601 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
603 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
604 and we are holding a cutthrough conn open, we can just append the rcpt to
605 that conn for verification purposes (and later delivery also). Simplest
606 coding means skipping this whole loop and doing the append separately. */
608 /* Can we re-use an open cutthrough connection? */
609 if ( cutthrough.fd >= 0
610 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
611 == vopt_callout_recipsender
612 && !random_local_part
615 done = cutthrough_multi(addr, host_list, tf, &yield);
617 /* If we did not use a cached connection, make connections to the hosts
618 and do real callouts. The list of hosts is passed in as an argument. */
620 for (host = host_list; host && !done; host = host->next)
624 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
629 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
634 /* Check the overall callout timeout */
636 if (time(NULL) - callout_start_time >= callout_overall)
638 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
642 /* Set IPv4 or IPv6 */
644 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
646 /* Expand and interpret the interface and port strings. The latter will not
647 be used if there is a host-specific port (e.g. from a manualroute router).
648 This has to be delayed till now, because they may expand differently for
649 different hosts. If there's a failure, log it, but carry on with the
652 deliver_host = host->name;
653 deliver_host_address = host->address;
654 deliver_host_port = host->port;
655 deliver_domain = addr->domain;
656 transport_name = addr->transport->name;
658 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
660 || !smtp_get_port(tf->port, addr, &port, US"callout")
662 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
667 sx.host_af = host_af,
669 sx.interface = interface;
670 sx.helo_data = tf->helo_data;
671 sx.tblock = addr->transport;
674 tls_retry_connection:
675 /* Set the address state so that errors are recorded in it */
677 addr->transport_return = PENDING_DEFER;
678 ob->connect_timeout = callout_connect;
679 ob->command_timeout = callout;
681 /* Get the channel set up ready for a message (MAIL FROM being the next
682 SMTP command to send. If we tried TLS but it failed, try again without
685 if ( (yield = smtp_setup_conn(&sx, FALSE)) == DEFER
686 && addr->basic_errno == ERRNO_TLSFAILURE
687 && ob->tls_tempfail_tryclear
688 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
691 log_write(0, LOG_MAIN, "TLS session failure:"
692 " callout unencrypted to %s [%s] (not in hosts_require_tls)",
693 host->name, host->address);
694 addr->transport_return = PENDING_DEFER;
695 yield = smtp_setup_conn(&sx, TRUE);
699 errno = addr->basic_errno;
700 transport_name = NULL;
701 deliver_host = deliver_host_address = NULL;
702 deliver_domain = save_deliver_domain;
704 /* Failure to accept HELO is cached; this blocks the whole domain for all
705 senders. I/O errors and defer responses are not cached. */
707 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
709 setflag(addr, af_verify_nsfail);
710 new_domain_record.result = ccache_reject;
718 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
719 the AUTH info for logging */
721 addr->authenticator = client_authenticator;
722 addr->auth_id = client_authenticated_id;
724 sx.from_addr = from_address;
725 sx.first_addr = sx.sync_addr = addr;
726 sx.ok = FALSE; /*XXX these 3 last might not be needed for verify? */
728 sx.completed_addr = FALSE;
730 new_domain_record.result =
731 old_domain_cache_result == ccache_reject_mfnull
732 ? ccache_reject_mfnull : ccache_accept;
734 /* Do the random local part check first. Temporarily replace the recipient
735 with the "random" value */
737 if (random_local_part)
739 uschar * main_address = addr->address;
740 const uschar * rcpt_domain = addr->domain;
743 uschar * errstr = NULL;
744 if ( testflag(addr, af_utf8_downcvt)
745 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
749 addr->message = errstr;
750 errno = ERRNO_EXPANDFAIL;
751 setflag(addr, af_verify_nsfail);
753 rcpt_domain = US""; /*XXX errorhandling! */
757 /* This would be ok for 1st rcpt of a cutthrough (XXX do we have a count?) , but no way to
758 handle a subsequent because of the RSET. So refuse to support any. */
759 cancel_cutthrough_connection("random-recipient");
761 addr->address = string_sprintf("%s@%.1000s",
762 random_local_part, rcpt_domain);
765 /* If accepted, we aren't going to do any further tests below.
766 Otherwise, cache a real negative response, and get back to the right
767 state to send RCPT. Unless there's some problem such as a dropped
768 connection, we expect to succeed, because the commands succeeded above.
769 However, some servers drop the connection after responding to an
770 invalid recipient, so on (any) error we drop and remake the connection.
771 XXX We don't care about that for postmaster_full. Should we?
773 XXX could we add another flag to the context, and have the common
774 code emit the RSET too? Even pipelined after the RCPT...
775 Then the main-verify call could use it if there's to be a subsequent
777 The sync_responses() would need to be taught about it and we'd
778 need another return code filtering out to here.
781 /* Remember when we last did a random test */
782 new_domain_record.random_stamp = time(NULL);
784 if (smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0)
785 switch(addr->transport_return)
788 new_domain_record.random_result = ccache_accept;
791 new_domain_record.random_result = ccache_reject;
793 /* Between each check, issue RSET, because some servers accept only
794 one recipient after MAIL FROM:<>.
795 XXX We don't care about that for postmaster_full. Should we? */
798 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
799 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
804 debug_printf("problem after random/rset/mfrom; reopen conn\n");
805 random_local_part = NULL;
807 tls_close(FALSE, TRUE);
809 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
810 (void)close(sx.inblock.sock);
811 sx.inblock.sock = sx.outblock.sock = -1;
812 #ifndef DISABLE_EVENT
813 (void) event_raise(addr->transport->event_action,
814 US"tcp:close", NULL);
816 addr->address = main_address;
817 addr->transport_return = PENDING_DEFER;
818 sx.first_addr = sx.sync_addr = addr;
821 sx.completed_addr = FALSE;
822 goto tls_retry_connection;
825 /* Re-setup for main verify, or for the error message when failing */
826 addr->address = main_address;
827 addr->transport_return = PENDING_DEFER;
828 sx.first_addr = sx.sync_addr = addr;
831 sx.completed_addr = FALSE;
836 /* Main verify. If the host is accepting all local parts, as determined
837 by the "random" check, we don't need to waste time doing any further
843 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
845 case 0: switch(addr->transport_return) /* ok so far */
847 case PENDING_OK: done = TRUE;
848 new_address_record.result = ccache_accept;
850 case FAIL: done = TRUE;
852 *failure_ptr = US"recipient";
853 new_address_record.result = ccache_reject;
859 case -1: /* MAIL response error */
860 *failure_ptr = US"mail";
861 if (errno == 0 && sx.buffer[0] == '5')
863 setflag(addr, af_verify_nsfail);
864 if (from_address[0] == 0)
865 new_domain_record.result = ccache_reject_mfnull;
868 /* non-MAIL read i/o error */
869 /* non-MAIL response timeout */
870 /* internal error; channel still usable */
871 default: break; /* transmit failed */
875 addr->auth_sndr = client_authenticated_sender;
877 deliver_host = deliver_host_address = NULL;
878 deliver_domain = save_deliver_domain;
880 /* Do postmaster check if requested; if a full check is required, we
881 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
883 if (done && pm_mailfrom)
885 /* Could possibly shift before main verify, just above, and be ok
886 for cutthrough. But no way to handle a subsequent rcpt, so just
888 cancel_cutthrough_connection("postmaster verify");
889 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
891 done = smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0
892 && smtp_read_response(&sx.inblock, sx.buffer,
893 sizeof(sx.buffer), '2', callout);
897 uschar * main_address = addr->address;
899 /*XXX oops, affixes */
900 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
901 addr->transport_return = PENDING_DEFER;
903 sx.from_addr = pm_mailfrom;
904 sx.first_addr = sx.sync_addr = addr;
907 sx.completed_addr = FALSE;
909 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
910 && addr->transport_return == PENDING_OK
914 done = (options & vopt_callout_fullpm) != 0
915 && smtp_write_command(&sx.outblock, FALSE,
916 "RCPT TO:<postmaster>\r\n") >= 0
917 && smtp_read_response(&sx.inblock, sx.buffer,
918 sizeof(sx.buffer), '2', callout);
920 /* Sort out the cache record */
922 new_domain_record.postmaster_stamp = time(NULL);
925 new_domain_record.postmaster_result = ccache_accept;
926 else if (errno == 0 && sx.buffer[0] == '5')
928 *failure_ptr = US"postmaster";
929 setflag(addr, af_verify_pmfail);
930 new_domain_record.postmaster_result = ccache_reject;
933 addr->address = main_address;
936 /* For any failure of the main check, other than a negative response, we just
937 close the connection and carry on. We can identify a negative response by the
938 fact that errno is zero. For I/O errors it will be non-zero
940 Set up different error texts for logging and for sending back to the caller
941 as an SMTP response. Log in all cases, using a one-line format. For sender
942 callouts, give a full response to the caller, but for recipient callouts,
943 don't give the IP address because this may be an internal host whose identity
944 is not to be widely broadcast. */
950 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
951 sx.send_quit = FALSE;
957 extern int acl_where; /* src/acl.c */
959 addr->message = string_sprintf(
960 "response to \"EHLO\" did not include SMTPUTF8");
961 addr->user_message = acl_where == ACL_WHERE_RCPT
962 ? US"533 no support for internationalised mailbox name"
963 : US"550 mailbox unavailable";
970 sx.send_quit = FALSE;
974 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
976 /*XXX test here is ugly; seem to have a split of responsibility for
977 building this message. Need to reationalise. Where is it done
978 before here, and when not?
979 Not == 5xx resp to MAIL on main-verify
981 if (!addr->message) addr->message =
982 string_sprintf("response to \"%s\" was: %s",
983 big_buffer, string_printing(sx.buffer));
985 addr->user_message = options & vopt_is_recipient
986 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
987 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
988 host->address, big_buffer, sx.buffer);
990 /* Hard rejection ends the process */
992 if (sx.buffer[0] == '5') /* Address rejected */
1000 /* End the SMTP conversation and close the connection. */
1002 /* Cutthrough - on a successful connect and recipient-verify with
1003 use-sender and we are 1st rcpt and have no cutthrough conn so far
1004 here is where we want to leave the conn open */
1005 if ( cutthrough.delivery
1009 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1010 == vopt_callout_recipsender
1011 && !random_local_part
1013 && cutthrough.fd < 0
1017 HDEBUG(D_acl|D_v) debug_printf("holding verify callout open for cutthrough delivery\n");
1019 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1020 cutthrough.nrcpt = 1;
1021 cutthrough.interface = interface;
1022 cutthrough.host = *host;
1023 cutthrough.addr = *addr; /* Save the address_item for later logging */
1024 cutthrough.addr.next = NULL;
1025 cutthrough.addr.host_used = &cutthrough.host;
1027 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1029 ctblock.buffer = ctbuffer;
1030 ctblock.buffersize = sizeof(ctbuffer);
1031 ctblock.ptr = ctbuffer;
1032 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1033 ctblock.sock = cutthrough.fd;
1037 /* Ensure no cutthrough on multiple address verifies */
1038 if (options & vopt_callout_recipsender)
1039 cancel_cutthrough_connection("not usable for cutthrough");
1042 (void) smtp_write_command(&sx.outblock, FALSE, "QUIT\r\n");
1044 /* Wait a short time for response, and discard it */
1045 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1049 if (sx.inblock.sock >= 0)
1052 tls_close(FALSE, TRUE);
1054 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1055 (void)close(sx.inblock.sock);
1056 sx.inblock.sock = sx.outblock.sock = -1;
1057 #ifndef DISABLE_EVENT
1058 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1063 if (!done || yield != OK)
1064 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1066 } /* Loop through all hosts, while !done */
1069 /* If we get here with done == TRUE, a successful callout happened, and yield
1070 will be set OK or FAIL according to the response to the RCPT command.
1071 Otherwise, we looped through the hosts but couldn't complete the business.
1072 However, there may be domain-specific information to cache in both cases. */
1074 if (!(options & vopt_callout_no_cache))
1075 cache_callout_write(&new_domain_record, addr->domain,
1076 done, &new_address_record, address_key);
1078 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1079 temporary error. If there was only one host, and a response was received, leave
1080 it alone if supplying details. Otherwise, give a generic response. */
1084 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1085 options & vopt_is_recipient ? "recipient" : "sender");
1088 addr->message = host_list->next || !addr->message
1089 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1091 addr->user_message = smtp_return_error_details
1092 ? string_sprintf("%s for <%s>.\n"
1093 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1094 "they may be permanently unreachable from this server. In the latter case,\n%s",
1095 dullmsg, addr->address,
1096 options & vopt_is_recipient
1097 ? "the address will never be accepted."
1098 : "you need to change the address or create an MX record for its domain\n"
1099 "if it is supposed to be generally accessible from the Internet.\n"
1100 "Talk to your mail administrator for details.")
1103 /* Force a specific error code */
1105 addr->basic_errno = ERRNO_CALLOUTDEFER;
1108 /* Come here from within the cache-reading code on fast-track exit. */
1111 tls_modify_variables(&tls_in);
1117 /* Called after recipient-acl to get a cutthrough connection open when
1118 one was requested and a recipient-verify wasn't subsequently done.
1121 open_cutthrough_connection( address_item * addr )
1126 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1127 /* We must use a copy of the address for verification, because it might
1131 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1132 rcpt_count > 1 ? "more" : "start");
1133 rc = verify_address(&addr2, NULL,
1134 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1135 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1137 addr->message = addr2.message;
1138 addr->user_message = addr2.user_message;
1139 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1145 /* Send given number of bytes from the buffer */
1147 cutthrough_send(int n)
1149 if(cutthrough.fd < 0)
1154 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1156 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1159 transport_count += n;
1160 ctblock.ptr= ctblock.buffer;
1164 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1171 _cutthrough_puts(uschar * cp, int n)
1175 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1176 if(!cutthrough_send(ctblock.buffersize))
1179 *ctblock.ptr++ = *cp++;
1184 /* Buffered output of counted data block. Return boolean success */
1186 cutthrough_puts(uschar * cp, int n)
1188 if (cutthrough.fd < 0) return TRUE;
1189 if (_cutthrough_puts(cp, n)) return TRUE;
1190 cancel_cutthrough_connection("transmit failed");
1196 _cutthrough_flush_send(void)
1198 int n= ctblock.ptr-ctblock.buffer;
1201 if(!cutthrough_send(n))
1207 /* Send out any bufferred output. Return boolean success. */
1209 cutthrough_flush_send(void)
1211 if (_cutthrough_flush_send()) return TRUE;
1212 cancel_cutthrough_connection("transmit failed");
1218 cutthrough_put_nl(void)
1220 return cutthrough_puts(US"\r\n", 2);
1224 /* Get and check response from cutthrough target */
1226 cutthrough_response(char expect, uschar ** copy, int timeout)
1228 smtp_inblock inblock;
1229 uschar inbuffer[4096];
1230 uschar responsebuffer[4096];
1232 inblock.buffer = inbuffer;
1233 inblock.buffersize = sizeof(inbuffer);
1234 inblock.ptr = inbuffer;
1235 inblock.ptrend = inbuffer;
1236 inblock.sock = cutthrough.fd;
1237 /* this relies on (inblock.sock == tls_out.active) */
1238 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1239 cancel_cutthrough_connection("target timeout on read");
1244 *copy = cp = string_copy(responsebuffer);
1245 /* Trim the trailing end of line */
1246 cp += Ustrlen(responsebuffer);
1247 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1248 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1251 return responsebuffer[0];
1255 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1257 cutthrough_predata(void)
1259 if(cutthrough.fd < 0)
1262 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1263 cutthrough_puts(US"DATA\r\n", 6);
1264 cutthrough_flush_send();
1266 /* Assume nothing buffered. If it was it gets ignored. */
1267 return cutthrough_response('3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1271 /* fd and tctx args only to match write_chunk() */
1273 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1276 while(s && (s2 = Ustrchr(s, '\n')))
1278 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1286 /* Buffered send of headers. Return success boolean. */
1287 /* Expands newlines to wire format (CR,NL). */
1288 /* Also sends header-terminating blank line. */
1290 cutthrough_headers_send(void)
1294 if(cutthrough.fd < 0)
1297 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1298 but having a separate buffered-output function (for now)
1300 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1302 tctx.tblock = cutthrough.addr.transport;
1303 tctx.addr = &cutthrough.addr;
1304 tctx.check_string = US".";
1305 tctx.escape_string = US"..";
1306 tctx.options = topt_use_crlf;
1308 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1311 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1317 close_cutthrough_connection(const char * why)
1319 if(cutthrough.fd >= 0)
1321 /* We could be sending this after a bunch of data, but that is ok as
1322 the only way to cancel the transfer in dataphase is to drop the tcp
1323 conn before the final dot.
1325 ctblock.ptr = ctbuffer;
1326 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1327 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1328 _cutthrough_flush_send();
1330 /* Wait a short time for response, and discard it */
1331 cutthrough_response('2', NULL, 1);
1334 tls_close(FALSE, TRUE);
1336 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1337 (void)close(cutthrough.fd);
1339 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1341 ctblock.ptr = ctbuffer;
1345 cancel_cutthrough_connection(const char * why)
1347 close_cutthrough_connection(why);
1348 cutthrough.delivery = FALSE;
1354 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1355 Log an OK response as a transmission.
1356 Close the connection.
1357 Return smtp response-class digit.
1360 cutthrough_finaldot(void)
1363 address_item * addr;
1364 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1366 /* Assume data finshed with new-line */
1367 if( !cutthrough_puts(US".", 1)
1368 || !cutthrough_put_nl()
1369 || !cutthrough_flush_send()
1371 return cutthrough.addr.message;
1373 res = cutthrough_response('2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1374 for (addr = &cutthrough.addr; addr; addr = addr->next)
1376 addr->message = cutthrough.addr.message;
1380 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1381 close_cutthrough_connection("delivered");
1385 delivery_log(LOG_MAIN, addr, 0,
1386 US"tmp-reject from cutthrough after DATA:");
1390 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1391 US"rejected after DATA:");
1398 return cutthrough.addr.message;
1403 /*************************************************
1404 * Copy error to toplevel address *
1405 *************************************************/
1407 /* This function is used when a verify fails or defers, to ensure that the
1408 failure or defer information is in the original toplevel address. This applies
1409 when an address is redirected to a single new address, and the failure or
1410 deferral happens to the child address.
1413 vaddr the verify address item
1414 addr the final address item
1417 Returns: the value of YIELD
1421 copy_error(address_item *vaddr, address_item *addr, int yield)
1425 vaddr->message = addr->message;
1426 vaddr->user_message = addr->user_message;
1427 vaddr->basic_errno = addr->basic_errno;
1428 vaddr->more_errno = addr->more_errno;
1429 vaddr->prop.address_data = addr->prop.address_data;
1430 copyflag(vaddr, addr, af_pass_message);
1438 /**************************************************
1439 * printf that automatically handles TLS if needed *
1440 ***************************************************/
1442 /* This function is used by verify_address() as a substitute for all fprintf()
1443 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1444 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1445 that assumes that we always use the smtp_out FILE* when not using TLS or the
1446 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1447 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1451 f the candidate FILE* to write to
1452 format format string
1453 ... optional arguments
1459 static void PRINTF_FUNCTION(2,3)
1460 respond_printf(FILE *f, const char *format, ...)
1464 va_start(ap, format);
1465 if (smtp_out && (f == smtp_out))
1466 smtp_vprintf(format, ap);
1468 vfprintf(f, format, ap);
1474 /*************************************************
1475 * Verify an email address *
1476 *************************************************/
1478 /* This function is used both for verification (-bv and at other times) and
1479 address testing (-bt), which is indicated by address_test_mode being set.
1482 vaddr contains the address to verify; the next field in this block
1484 f if not NULL, write the result to this file
1485 options various option bits:
1486 vopt_fake_sender => this sender verify is not for the real
1487 sender (it was verify=sender=xxxx or an address from a
1488 header line) - rewriting must not change sender_address
1489 vopt_is_recipient => this is a recipient address, otherwise
1490 it's a sender address - this affects qualification and
1491 rewriting and messages from callouts
1492 vopt_qualify => qualify an unqualified address; else error
1493 vopt_expn => called from SMTP EXPN command
1494 vopt_success_on_redirect => when a new address is generated
1495 the verification instantly succeeds
1497 These ones are used by do_callout() -- the options variable
1500 vopt_callout_fullpm => if postmaster check, do full one
1501 vopt_callout_no_cache => don't use callout cache
1502 vopt_callout_random => do the "random" thing
1503 vopt_callout_recipsender => use real sender for recipient
1504 vopt_callout_recippmaster => use postmaster for recipient
1506 callout if > 0, specifies that callout is required, and gives timeout
1507 for individual commands
1508 callout_overall if > 0, gives overall timeout for the callout function;
1509 if < 0, a default is used (see do_callout())
1510 callout_connect the connection timeout for callouts
1511 se_mailfrom when callout is requested to verify a sender, use this
1512 in MAIL FROM; NULL => ""
1513 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1514 thing and use this as the sender address (may be "")
1516 routed if not NULL, set TRUE if routing succeeded, so we can
1517 distinguish between routing failed and callout failed
1519 Returns: OK address verified
1520 FAIL address failed to verify
1521 DEFER can't tell at present
1525 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1526 int callout_overall, int callout_connect, uschar *se_mailfrom,
1527 uschar *pm_mailfrom, BOOL *routed)
1530 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1531 BOOL expn = (options & vopt_expn) != 0;
1532 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1535 int verify_type = expn? v_expn :
1536 address_test_mode? v_none :
1537 options & vopt_is_recipient? v_recipient : v_sender;
1538 address_item *addr_list;
1539 address_item *addr_new = NULL;
1540 address_item *addr_remote = NULL;
1541 address_item *addr_local = NULL;
1542 address_item *addr_succeed = NULL;
1543 uschar **failure_ptr = options & vopt_is_recipient
1544 ? &recipient_verify_failure : &sender_verify_failure;
1545 uschar *ko_prefix, *cr;
1546 uschar *address = vaddr->address;
1547 uschar *save_sender;
1548 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1550 /* Clear, just in case */
1552 *failure_ptr = NULL;
1554 /* Set up a prefix and suffix for error message which allow us to use the same
1555 output statements both in EXPN mode (where an SMTP response is needed) and when
1556 debugging with an output file. */
1560 ko_prefix = US"553 ";
1563 else ko_prefix = cr = US"";
1565 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1567 if (parse_find_at(address) == NULL)
1569 if ((options & vopt_qualify) == 0)
1572 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1573 ko_prefix, address, cr);
1574 *failure_ptr = US"qualify";
1577 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1582 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1583 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1586 /* Rewrite and report on it. Clear the domain and local part caches - these
1587 may have been set by domains and local part tests during an ACL. */
1589 if (global_rewrite_rules != NULL)
1591 uschar *old = address;
1592 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1593 global_rewrite_rules, rewrite_existflags);
1596 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1597 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1598 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1602 /* If this is the real sender address, we must update sender_address at
1603 this point, because it may be referred to in the routers. */
1605 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1606 sender_address = address;
1608 /* If the address was rewritten to <> no verification can be done, and we have
1609 to return OK. This rewriting is permitted only for sender addresses; for other
1610 addresses, such rewriting fails. */
1612 if (address[0] == 0) return OK;
1614 /* Flip the legacy TLS-related variables over to the outbound set in case
1615 they're used in the context of a transport used by verification. Reset them
1616 at exit from this routine (so no returns allowed from here on). */
1618 tls_modify_variables(&tls_out);
1620 /* Save a copy of the sender address for re-instating if we change it to <>
1621 while verifying a sender address (a nice bit of self-reference there). */
1623 save_sender = sender_address;
1625 /* Observability variable for router/transport use */
1627 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1629 /* Update the address structure with the possibly qualified and rewritten
1630 address. Set it up as the starting address on the chain of new addresses. */
1632 vaddr->address = address;
1635 /* We need a loop, because an address can generate new addresses. We must also
1636 cope with generated pipes and files at the top level. (See also the code and
1637 comment in deliver.c.) However, it is usually the case that the router for
1638 user's .forward files has its verify flag turned off.
1640 If an address generates more than one child, the loop is used only when
1641 full_info is set, and this can only be set locally. Remote enquiries just get
1642 information about the top level address, not anything that it generated. */
1647 address_item *addr = addr_new;
1649 addr_new = addr->next;
1654 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1655 debug_printf("Considering %s\n", addr->address);
1658 /* Handle generated pipe, file or reply addresses. We don't get these
1659 when handling EXPN, as it does only one level of expansion. */
1661 if (testflag(addr, af_pfr))
1668 if (addr->address[0] == '>')
1670 allow = testflag(addr, af_allow_reply);
1671 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1675 allow = (addr->address[0] == '|')?
1676 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1677 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1680 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1681 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1682 "%s\n", addr->message);
1684 fprintf(f, "\n transport = %s\n", addr->transport->name);
1686 fprintf(f, " *** forbidden ***\n");
1691 /* Just in case some router parameter refers to it. */
1693 return_path = addr->prop.errors_address
1694 ? addr->prop.errors_address : sender_address;
1696 /* Split the address into domain and local part, handling the %-hack if
1697 necessary, and then route it. While routing a sender address, set
1698 $sender_address to <> because that is what it will be if we were trying to
1699 send a bounce to the sender. */
1701 if (routed) *routed = FALSE;
1702 if ((rc = deliver_split_address(addr)) == OK)
1704 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1705 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1706 &addr_succeed, verify_type);
1707 sender_address = save_sender; /* Put back the real sender */
1710 /* If routing an address succeeded, set the flag that remembers, for use when
1711 an ACL cached a sender verify (in case a callout fails). Then if routing set
1712 up a list of hosts or the transport has a host list, and the callout option
1713 is set, and we aren't in a host checking run, do the callout verification,
1714 and set another flag that notes that a callout happened. */
1718 if (routed) *routed = TRUE;
1721 transport_instance * tp;
1722 host_item * host_list = addr->host_list;
1724 /* Make up some data for use in the case where there is no remote
1727 transport_feedback tf = {
1728 NULL, /* interface (=> any) */
1729 US"smtp", /* port */
1730 US"smtp", /* protocol */
1732 US"$smtp_active_hostname", /* helo_data */
1733 FALSE, /* hosts_override */
1734 FALSE, /* hosts_randomize */
1735 FALSE, /* gethostbyname */
1736 TRUE, /* qualify_single */
1737 FALSE /* search_parents */
1740 /* If verification yielded a remote transport, we want to use that
1741 transport's options, so as to mimic what would happen if we were really
1742 sending a message to this address. */
1744 if ((tp = addr->transport) && !tp->info->local)
1746 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1748 /* If the transport has hosts and the router does not, or if the
1749 transport is configured to override the router's hosts, we must build a
1750 host list of the transport's hosts, and find the IP addresses */
1752 if (tf.hosts && (!host_list || tf.hosts_override))
1755 const uschar *save_deliver_domain = deliver_domain;
1756 uschar *save_deliver_localpart = deliver_localpart;
1758 host_list = NULL; /* Ignore the router's hosts */
1760 deliver_domain = addr->domain;
1761 deliver_localpart = addr->local_part;
1762 s = expand_string(tf.hosts);
1763 deliver_domain = save_deliver_domain;
1764 deliver_localpart = save_deliver_localpart;
1768 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1769 "\"%s\" in %s transport for callout: %s", tf.hosts,
1770 tp->name, expand_string_message);
1775 host_item *host, *nexthost;
1776 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1778 /* Just ignore failures to find a host address. If we don't manage
1779 to find any addresses, the callout will defer. Note that more than
1780 one address may be found for a single host, which will result in
1781 additional host items being inserted into the chain. Hence we must
1782 save the next host first. */
1784 flags = HOST_FIND_BY_A;
1785 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1786 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1788 for (host = host_list; host; host = nexthost)
1790 nexthost = host->next;
1791 if (tf.gethostbyname ||
1792 string_is_ip_address(host->name, NULL) != 0)
1793 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1796 dnssec_domains * dnssec_domains = NULL;
1797 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1799 smtp_transport_options_block * ob =
1800 (smtp_transport_options_block *) tp->options_block;
1801 dnssec_domains = &ob->dnssec;
1804 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1805 dnssec_domains, NULL, NULL);
1812 /* Can only do a callout if we have at least one host! If the callout
1813 fails, it will have set ${sender,recipient}_verify_failure. */
1817 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1818 if (host_checking && !host_checking_callout)
1821 debug_printf("... callout omitted by default when host testing\n"
1822 "(Use -bhc if you want the callouts to happen.)\n");
1827 deliver_set_expansions(addr);
1829 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1830 callout_connect, options, se_mailfrom, pm_mailfrom);
1835 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1836 "transport provided a host list\n");
1841 /* Otherwise, any failure is a routing failure */
1843 else *failure_ptr = US"route";
1845 /* A router may return REROUTED if it has set up a child address as a result
1846 of a change of domain name (typically from widening). In this case we always
1847 want to continue to verify the new child. */
1849 if (rc == REROUTED) continue;
1851 /* Handle hard failures */
1858 address_item *p = addr->parent;
1860 respond_printf(f, "%s%s %s", ko_prefix,
1861 full_info ? addr->address : address,
1862 address_test_mode ? "is undeliverable" : "failed to verify");
1863 if (!expn && admin_user)
1865 if (addr->basic_errno > 0)
1866 respond_printf(f, ": %s", strerror(addr->basic_errno));
1868 respond_printf(f, ": %s", addr->message);
1871 /* Show parents iff doing full info */
1873 if (full_info) while (p)
1875 respond_printf(f, "%s\n <-- %s", cr, p->address);
1878 respond_printf(f, "%s\n", cr);
1880 cancel_cutthrough_connection("routing hard fail");
1884 yield = copy_error(vaddr, addr, FAIL);
1892 else if (rc == DEFER)
1897 address_item *p = addr->parent;
1898 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1899 full_info? addr->address : address);
1900 if (!expn && admin_user)
1902 if (addr->basic_errno > 0)
1903 respond_printf(f, ": %s", strerror(addr->basic_errno));
1905 respond_printf(f, ": %s", addr->message);
1906 else if (addr->basic_errno <= 0)
1907 respond_printf(f, ": unknown error");
1910 /* Show parents iff doing full info */
1912 if (full_info) while (p)
1914 respond_printf(f, "%s\n <-- %s", cr, p->address);
1917 respond_printf(f, "%s\n", cr);
1919 cancel_cutthrough_connection("routing soft fail");
1923 yield = copy_error(vaddr, addr, DEFER);
1926 if (yield == OK) yield = DEFER;
1929 /* If we are handling EXPN, we do not want to continue to route beyond
1930 the top level (whose address is in "address"). */
1934 uschar *ok_prefix = US"250-";
1937 if (!addr_local && !addr_remote)
1938 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1940 respond_printf(f, "250 <%s>\r\n", address);
1944 address_item *addr2 = addr_new;
1945 addr_new = addr2->next;
1946 if (!addr_new) ok_prefix = US"250 ";
1947 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1953 /* Successful routing other than EXPN. */
1957 /* Handle successful routing when short info wanted. Otherwise continue for
1958 other (generated) addresses. Short info is the operational case. Full info
1959 can be requested only when debug_selector != 0 and a file is supplied.
1961 There is a conflict between the use of aliasing as an alternate email
1962 address, and as a sort of mailing list. If an alias turns the incoming
1963 address into just one address (e.g. J.Caesar->jc44) you may well want to
1964 carry on verifying the generated address to ensure it is valid when
1965 checking incoming mail. If aliasing generates multiple addresses, you
1966 probably don't want to do this. Exim therefore treats the generation of
1967 just a single new address as a special case, and continues on to verify the
1968 generated address. */
1970 if ( !full_info /* Stop if short info wanted AND */
1971 && ( ( !addr_new /* No new address OR */
1972 || addr_new->next /* More than one new address OR */
1973 || testflag(addr_new, af_pfr) /* New address is pfr */
1976 ( addr_new /* At least one new address AND */
1977 && success_on_redirect /* success_on_redirect is set */
1981 if (f) fprintf(f, "%s %s\n",
1982 address, address_test_mode ? "is deliverable" : "verified");
1984 /* If we have carried on to verify a child address, we want the value
1985 of $address_data to be that of the child */
1987 vaddr->prop.address_data = addr->prop.address_data;
1989 /* If stopped because more than one new address, cannot cutthrough */
1991 if (addr_new && addr_new->next)
1992 cancel_cutthrough_connection("multiple addresses from routing");
1998 } /* Loop for generated addresses */
2000 /* Display the full results of the successful routing, including any generated
2001 addresses. Control gets here only when full_info is set, which requires f not
2002 to be NULL, and this occurs only when a top-level verify is called with the
2003 debugging switch on.
2005 If there are no local and no remote addresses, and there were no pipes, files,
2006 or autoreplies, and there were no errors or deferments, the message is to be
2007 discarded, usually because of the use of :blackhole: in an alias file. */
2009 if (allok && !addr_local && !addr_remote)
2011 fprintf(f, "mail to %s is discarded\n", address);
2015 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2018 address_item *addr = addr_list;
2019 address_item *p = addr->parent;
2020 transport_instance * tp = addr->transport;
2022 addr_list = addr->next;
2024 fprintf(f, "%s", CS addr->address);
2025 #ifdef EXPERIMENTAL_SRS
2026 if(addr->prop.srs_sender)
2027 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2030 /* If the address is a duplicate, show something about it. */
2032 if (!testflag(addr, af_pfr))
2035 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2036 fprintf(f, " [duplicate, would not be delivered]");
2037 else tree_add_duplicate(addr->unique, addr);
2040 /* Now show its parents */
2042 for (p = addr->parent; p; p = p->parent)
2043 fprintf(f, "\n <-- %s", p->address);
2046 /* Show router, and transport */
2048 fprintf(f, "router = %s, transport = %s\n",
2049 addr->router->name, tp ? tp->name : US"unset");
2051 /* Show any hosts that are set up by a router unless the transport
2052 is going to override them; fiddle a bit to get a nice format. */
2054 if (addr->host_list && tp && !tp->overrides_hosts)
2059 for (h = addr->host_list; h; h = h->next)
2060 { /* get max lengths of host names, addrs */
2061 int len = Ustrlen(h->name);
2062 if (len > maxlen) maxlen = len;
2063 len = h->address ? Ustrlen(h->address) : 7;
2064 if (len > maxaddlen) maxaddlen = len;
2066 for (h = addr->host_list; h; h = h->next)
2068 fprintf(f, " host %-*s ", maxlen, h->name);
2071 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2072 else if (tp->info->local)
2073 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2075 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2077 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2078 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2079 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2080 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2086 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2087 the -bv or -bt case). */
2091 tls_modify_variables(&tls_in);
2099 /*************************************************
2100 * Check headers for syntax errors *
2101 *************************************************/
2103 /* This function checks those header lines that contain addresses, and verifies
2104 that all the addresses therein are syntactially correct.
2107 msgptr where to put an error message
2114 verify_check_headers(uschar **msgptr)
2120 for (h = header_list; h != NULL && yield == OK; h = h->next)
2122 if (h->type != htype_from &&
2123 h->type != htype_reply_to &&
2124 h->type != htype_sender &&
2125 h->type != htype_to &&
2126 h->type != htype_cc &&
2127 h->type != htype_bcc)
2130 colon = Ustrchr(h->text, ':');
2132 while (isspace(*s)) s++;
2134 /* Loop for multiple addresses in the header, enabling group syntax. Note
2135 that we have to reset this after the header has been scanned. */
2137 parse_allow_group = TRUE;
2141 uschar *ss = parse_find_address_end(s, FALSE);
2142 uschar *recipient, *errmess;
2143 int terminator = *ss;
2144 int start, end, domain;
2146 /* Temporarily terminate the string at this point, and extract the
2147 operative address within, allowing group syntax. */
2150 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2153 /* Permit an unqualified address only if the message is local, or if the
2154 sending host is configured to be permitted to send them. */
2156 if (recipient != NULL && domain == 0)
2158 if (h->type == htype_from || h->type == htype_sender)
2160 if (!allow_unqualified_sender) recipient = NULL;
2164 if (!allow_unqualified_recipient) recipient = NULL;
2166 if (recipient == NULL) errmess = US"unqualified address not permitted";
2169 /* It's an error if no address could be extracted, except for the special
2170 case of an empty address. */
2172 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2174 uschar *verb = US"is";
2179 /* Arrange not to include any white space at the end in the
2180 error message or the header name. */
2182 while (t > s && isspace(t[-1])) t--;
2183 while (tt > h->text && isspace(tt[-1])) tt--;
2185 /* Add the address that failed to the error message, since in a
2186 header with very many addresses it is sometimes hard to spot
2187 which one is at fault. However, limit the amount of address to
2188 quote - cases have been seen where, for example, a missing double
2189 quote in a humungous To: header creates an "address" that is longer
2190 than string_sprintf can handle. */
2199 /* deconst cast ok as we're passing a non-const to string_printing() */
2200 *msgptr = US string_printing(
2201 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2202 errmess, tt - h->text, h->text, verb, len, s));
2205 break; /* Out of address loop */
2208 /* Advance to the next address */
2210 s = ss + (terminator? 1:0);
2211 while (isspace(*s)) s++;
2212 } /* Next address */
2214 parse_allow_group = FALSE;
2215 parse_found_group = FALSE;
2216 } /* Next header unless yield has been set FALSE */
2222 /*************************************************
2223 * Check header names for 8-bit characters *
2224 *************************************************/
2226 /* This function checks for invalid characters in header names. See
2227 RFC 5322, 2.2. and RFC 6532, 3.
2230 msgptr where to put an error message
2237 verify_check_header_names_ascii(uschar **msgptr)
2242 for (h = header_list; h != NULL; h = h->next)
2244 colon = Ustrchr(h->text, ':');
2245 for(s = h->text; s < colon; s++)
2247 if ((*s < 33) || (*s > 126))
2249 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2250 colon - h->text, h->text);
2258 /*************************************************
2259 * Check for blind recipients *
2260 *************************************************/
2262 /* This function checks that every (envelope) recipient is mentioned in either
2263 the To: or Cc: header lines, thus detecting blind carbon copies.
2265 There are two ways of scanning that could be used: either scan the header lines
2266 and tick off the recipients, or scan the recipients and check the header lines.
2267 The original proposed patch did the former, but I have chosen to do the latter,
2268 because (a) it requires no memory and (b) will use fewer resources when there
2269 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2272 Returns: OK if there are no blind recipients
2273 FAIL if there is at least one blind recipient
2277 verify_check_notblind(void)
2280 for (i = 0; i < recipients_count; i++)
2284 uschar *address = recipients_list[i].address;
2286 for (h = header_list; !found && h != NULL; h = h->next)
2290 if (h->type != htype_to && h->type != htype_cc) continue;
2292 colon = Ustrchr(h->text, ':');
2294 while (isspace(*s)) s++;
2296 /* Loop for multiple addresses in the header, enabling group syntax. Note
2297 that we have to reset this after the header has been scanned. */
2299 parse_allow_group = TRUE;
2303 uschar *ss = parse_find_address_end(s, FALSE);
2304 uschar *recipient,*errmess;
2305 int terminator = *ss;
2306 int start, end, domain;
2308 /* Temporarily terminate the string at this point, and extract the
2309 operative address within, allowing group syntax. */
2312 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2315 /* If we found a valid recipient that has a domain, compare it with the
2316 envelope recipient. Local parts are compared case-sensitively, domains
2317 case-insensitively. By comparing from the start with length "domain", we
2318 include the "@" at the end, which ensures that we are comparing the whole
2319 local part of each address. */
2321 if (recipient != NULL && domain != 0)
2323 found = Ustrncmp(recipient, address, domain) == 0 &&
2324 strcmpic(recipient + domain, address + domain) == 0;
2328 /* Advance to the next address */
2330 s = ss + (terminator? 1:0);
2331 while (isspace(*s)) s++;
2332 } /* Next address */
2334 parse_allow_group = FALSE;
2335 parse_found_group = FALSE;
2336 } /* Next header (if found is false) */
2338 if (!found) return FAIL;
2339 } /* Next recipient */
2346 /*************************************************
2347 * Find if verified sender *
2348 *************************************************/
2350 /* Usually, just a single address is verified as the sender of the message.
2351 However, Exim can be made to verify other addresses as well (often related in
2352 some way), and this is useful in some environments. There may therefore be a
2353 chain of such addresses that have previously been tested. This function finds
2354 whether a given address is on the chain.
2356 Arguments: the address to be verified
2357 Returns: pointer to an address item, or NULL
2361 verify_checked_sender(uschar *sender)
2364 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2365 if (Ustrcmp(sender, addr->address) == 0) break;
2373 /*************************************************
2374 * Get valid header address *
2375 *************************************************/
2377 /* Scan the originator headers of the message, looking for an address that
2378 verifies successfully. RFC 822 says:
2380 o The "Sender" field mailbox should be sent notices of
2381 any problems in transport or delivery of the original
2382 messages. If there is no "Sender" field, then the
2383 "From" field mailbox should be used.
2385 o If the "Reply-To" field exists, then the reply should
2386 go to the addresses indicated in that field and not to
2387 the address(es) indicated in the "From" field.
2389 So we check a Sender field if there is one, else a Reply_to field, else a From
2390 field. As some strange messages may have more than one of these fields,
2391 especially if they are resent- fields, check all of them if there is more than
2395 user_msgptr points to where to put a user error message
2396 log_msgptr points to where to put a log error message
2397 callout timeout for callout check (passed to verify_address())
2398 callout_overall overall callout timeout (ditto)
2399 callout_connect connect callout timeout (ditto)
2400 se_mailfrom mailfrom for verify; NULL => ""
2401 pm_mailfrom sender for pm callout check (passed to verify_address())
2402 options callout options (passed to verify_address())
2403 verrno where to put the address basic_errno
2405 If log_msgptr is set to something without setting user_msgptr, the caller
2406 normally uses log_msgptr for both things.
2408 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2409 FAIL is given if no appropriate headers are found
2413 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2414 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2415 uschar *pm_mailfrom, int options, int *verrno)
2417 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2422 for (i = 0; i < 3 && !done; i++)
2425 for (h = header_list; h != NULL && !done; h = h->next)
2427 int terminator, new_ok;
2428 uschar *s, *ss, *endname;
2430 if (h->type != header_types[i]) continue;
2431 s = endname = Ustrchr(h->text, ':') + 1;
2433 /* Scan the addresses in the header, enabling group syntax. Note that we
2434 have to reset this after the header has been scanned. */
2436 parse_allow_group = TRUE;
2440 address_item *vaddr;
2442 while (isspace(*s) || *s == ',') s++;
2443 if (*s == 0) break; /* End of header */
2445 ss = parse_find_address_end(s, FALSE);
2447 /* The terminator is a comma or end of header, but there may be white
2448 space preceding it (including newline for the last address). Move back
2449 past any white space so we can check against any cached envelope sender
2450 address verifications. */
2452 while (isspace(ss[-1])) ss--;
2456 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2457 (int)(endname - h->text), h->text, s);
2459 /* See if we have already verified this address as an envelope sender,
2460 and if so, use the previous answer. */
2462 vaddr = verify_checked_sender(s);
2464 if (vaddr != NULL && /* Previously checked */
2465 (callout <= 0 || /* No callout needed; OR */
2466 vaddr->special_action > 256)) /* Callout was done */
2468 new_ok = vaddr->special_action & 255;
2469 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2470 *ss = terminator; /* Restore shortened string */
2473 /* Otherwise we run the verification now. We must restore the shortened
2474 string before running the verification, so the headers are correct, in
2475 case there is any rewriting. */
2479 int start, end, domain;
2480 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2485 /* If we found an empty address, just carry on with the next one, but
2486 kill the message. */
2488 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2495 /* If verification failed because of a syntax error, fail this
2496 function, and ensure that the failing address gets added to the error
2499 if (address == NULL)
2502 while (ss > s && isspace(ss[-1])) ss--;
2503 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2504 "scanning for sender: %s in \"%.*s\"",
2505 endname - h->text, h->text, *log_msgptr, ss - s, s);
2511 /* Else go ahead with the sender verification. But it isn't *the*
2512 sender of the message, so set vopt_fake_sender to stop sender_address
2513 being replaced after rewriting or qualification. */
2517 vaddr = deliver_make_addr(address, FALSE);
2518 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2519 callout, callout_overall, callout_connect, se_mailfrom,
2524 /* We now have the result, either newly found, or cached. If we are
2525 giving out error details, set a specific user error. This means that the
2526 last of these will be returned to the user if all three fail. We do not
2527 set a log message - the generic one below will be used. */
2531 *verrno = vaddr->basic_errno;
2532 if (smtp_return_error_details)
2534 *user_msgptr = string_sprintf("Rejected after DATA: "
2535 "could not verify \"%.*s\" header address\n%s: %s",
2536 endname - h->text, h->text, vaddr->address, vaddr->message);
2540 /* Success or defer */
2549 if (new_ok == DEFER) yield = DEFER;
2551 /* Move on to any more addresses in the header */
2554 } /* Next address */
2556 parse_allow_group = FALSE;
2557 parse_found_group = FALSE;
2558 } /* Next header, unless done */
2559 } /* Next header type unless done */
2561 if (yield == FAIL && *log_msgptr == NULL)
2562 *log_msgptr = US"there is no valid sender in any header line";
2564 if (yield == DEFER && *log_msgptr == NULL)
2565 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2573 /*************************************************
2574 * Get RFC 1413 identification *
2575 *************************************************/
2577 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2578 the timeout is set to zero, then the query is not done. There may also be lists
2579 of hosts and nets which are exempt. To guard against malefactors sending
2580 non-printing characters which could, for example, disrupt a message's headers,
2581 make sure the string consists of printing characters only.
2584 port the port to connect to; usually this is IDENT_PORT (113), but when
2585 running in the test harness with -bh a different value is used.
2589 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2593 verify_get_ident(int port)
2595 int sock, host_af, qlen;
2596 int received_sender_port, received_interface_port, n;
2598 uschar buffer[2048];
2600 /* Default is no ident. Check whether we want to do an ident check for this
2603 sender_ident = NULL;
2604 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2607 DEBUG(D_ident) debug_printf("doing ident callback\n");
2609 /* Set up a connection to the ident port of the remote host. Bind the local end
2610 to the incoming interface address. If the sender host address is an IPv6
2611 address, the incoming interface address will also be IPv6. */
2613 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2614 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2616 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2618 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2623 if (ip_connect(sock, host_af, sender_host_address, port,
2624 rfc1413_query_timeout, TRUE) < 0)
2626 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2627 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2628 sender_host_address);
2630 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2631 sender_host_address, strerror(errno));
2635 /* Construct and send the query. */
2637 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2638 qlen = Ustrlen(buffer);
2639 if (send(sock, buffer, qlen, 0) < 0)
2641 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2645 /* Read a response line. We put it into the rest of the buffer, using several
2646 recv() calls if necessary. */
2654 int size = sizeof(buffer) - (p - buffer);
2656 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2657 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2658 if (count <= 0) goto END_OFF; /* Read error or EOF */
2660 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2661 generous, and accept a plain \n terminator as well. The only illegal
2664 for (pp = p; pp < p + count; pp++)
2666 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2669 if (pp[-1] == '\r') pp--;
2671 goto GOT_DATA; /* Break out of both loops */
2675 /* Reached the end of the data without finding \n. Let the loop continue to
2676 read some more, if there is room. */
2683 /* We have received a line of data. Check it carefully. It must start with the
2684 same two port numbers that we sent, followed by data as defined by the RFC. For
2687 12345 , 25 : USERID : UNIX :root
2689 However, the amount of white space may be different to what we sent. In the
2690 "osname" field there may be several sub-fields, comma separated. The data we
2691 actually want to save follows the third colon. Some systems put leading spaces
2692 in it - we discard those. */
2694 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2695 &received_interface_port, &n) != 2 ||
2696 received_sender_port != sender_host_port ||
2697 received_interface_port != interface_port)
2700 p = buffer + qlen + n;
2701 while(isspace(*p)) p++;
2702 if (*p++ != ':') goto END_OFF;
2703 while(isspace(*p)) p++;
2704 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2706 while(isspace(*p)) p++;
2707 if (*p++ != ':') goto END_OFF;
2708 while (*p != 0 && *p != ':') p++;
2709 if (*p++ == 0) goto END_OFF;
2710 while(isspace(*p)) p++;
2711 if (*p == 0) goto END_OFF;
2713 /* The rest of the line is the data we want. We turn it into printing
2714 characters when we save it, so that it cannot mess up the format of any logging
2715 or Received: lines into which it gets inserted. We keep a maximum of 127
2716 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2718 sender_ident = US string_printing(string_copyn(p, 127));
2719 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2729 /*************************************************
2730 * Match host to a single host-list item *
2731 *************************************************/
2733 /* This function compares a host (name or address) against a single item
2734 from a host list. The host name gets looked up if it is needed and is not
2735 already known. The function is called from verify_check_this_host() via
2736 match_check_list(), which is why most of its arguments are in a single block.
2739 arg the argument block (see below)
2740 ss the host-list item
2741 valueptr where to pass back looked up data, or NULL
2742 error for error message when returning ERROR
2745 host_name (a) the host name, or
2746 (b) NULL, implying use sender_host_name and
2747 sender_host_aliases, looking them up if required, or
2748 (c) the empty string, meaning that only IP address matches
2750 host_address the host address
2751 host_ipv4 the IPv4 address taken from an IPv6 one
2755 DEFER lookup deferred
2756 ERROR (a) failed to find the host name or IP address, or
2757 (b) unknown lookup type specified, or
2758 (c) host name encountered when only IP addresses are
2763 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2765 check_host_block *cb = (check_host_block *)arg;
2768 BOOL iplookup = FALSE;
2769 BOOL isquery = FALSE;
2770 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2775 /* Optimize for the special case when the pattern is "*". */
2777 if (*ss == '*' && ss[1] == 0) return OK;
2779 /* If the pattern is empty, it matches only in the case when there is no host -
2780 this can occur in ACL checking for SMTP input using the -bs option. In this
2781 situation, the host address is the empty string. */
2783 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2784 if (*ss == 0) return FAIL;
2786 /* If the pattern is precisely "@" then match against the primary host name,
2787 provided that host name matching is permitted; if it's "@[]" match against the
2788 local host's IP addresses. */
2794 if (isiponly) return ERROR;
2795 ss = primary_hostname;
2797 else if (Ustrcmp(ss, "@[]") == 0)
2799 ip_address_item *ip;
2800 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2801 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2806 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2807 a (possibly masked) comparison with the current IP address. */
2809 if (string_is_ip_address(ss, &maskoffset) != 0)
2810 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2812 /* The pattern is not an IP address. A common error that people make is to omit
2813 one component of an IPv4 address, either by accident, or believing that, for
2814 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,
2815 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2816 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2817 ancient specification.) To aid in debugging these cases, we give a specific
2818 error if the pattern contains only digits and dots or contains a slash preceded
2819 only by digits and dots (a slash at the start indicates a file name and of
2820 course slashes may be present in lookups, but not preceded only by digits and
2823 for (t = ss; isdigit(*t) || *t == '.'; t++);
2824 if (*t == 0 || (*t == '/' && t != ss))
2826 *error = US"malformed IPv4 address or address mask";
2830 /* See if there is a semicolon in the pattern */
2832 semicolon = Ustrchr(ss, ';');
2834 /* If we are doing an IP address only match, then all lookups must be IP
2835 address lookups, even if there is no "net-". */
2839 iplookup = semicolon != NULL;
2842 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2843 a lookup on a masked IP network, in textual form. We obey this code even if we
2844 have already set iplookup, so as to skip over the "net-" prefix and to set the
2845 mask length. The net- stuff really only applies to single-key lookups where the
2846 key is implicit. For query-style lookups the key is specified in the query.
2847 From release 4.30, the use of net- for query style is no longer needed, but we
2848 retain it for backward compatibility. */
2850 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2853 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2854 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2855 iplookup = (*t++ == '-');
2859 /* Do the IP address lookup if that is indeed what we have */
2867 uschar *filename, *key, *result;
2870 /* Find the search type */
2872 search_type = search_findtype(t, semicolon - t);
2874 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2875 search_error_message);
2877 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2878 is no file name, and the "key" is just the query. For query-style with a file
2879 name, we have to fish the file off the start of the query. For a single-key
2880 lookup, the key is the current IP address, masked appropriately, and
2881 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2882 dot separators instead of colons, except when the lookup type is "iplsearch".
2885 if (mac_islookup(search_type, lookup_absfilequery))
2887 filename = semicolon + 1;
2889 while (*key != 0 && !isspace(*key)) key++;
2890 filename = string_copyn(filename, key - filename);
2891 while (isspace(*key)) key++;
2893 else if (mac_islookup(search_type, lookup_querystyle))
2896 key = semicolon + 1;
2898 else /* Single-key style */
2900 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2902 insize = host_aton(cb->host_address, incoming);
2903 host_mask(insize, incoming, mlen);
2904 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2906 filename = semicolon + 1;
2909 /* Now do the actual lookup; note that there is no search_close() because
2910 of the caching arrangements. */
2912 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2913 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2915 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2916 if (valueptr != NULL) *valueptr = result;
2917 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2920 /* The pattern is not an IP address or network reference of any kind. That is,
2921 it is a host name pattern. If this is an IP only match, there's an error in the
2926 *error = US"cannot match host name in match_ip list";
2930 /* Check the characters of the pattern to see if they comprise only letters,
2931 digits, full stops, and hyphens (the constituents of domain names). Allow
2932 underscores, as they are all too commonly found. Sigh. Also, if
2933 allow_utf8_domains is set, allow top-bit characters. */
2935 for (t = ss; *t != 0; t++)
2936 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2937 (!allow_utf8_domains || *t < 128)) break;
2939 /* If the pattern is a complete domain name, with no fancy characters, look up
2940 its IP address and match against that. Note that a multi-homed host will add
2941 items to the chain. */
2952 /* Using byname rather than bydns here means we cannot determine dnssec
2953 status. On the other hand it is unclear how that could be either
2954 propagated up or enforced. */
2956 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2957 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2960 for (hh = &h; hh != NULL; hh = hh->next)
2962 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2966 if (rc == HOST_FIND_AGAIN) return DEFER;
2967 *error = string_sprintf("failed to find IP address for %s", ss);
2971 /* Almost all subsequent comparisons require the host name, and can be done
2972 using the general string matching function. When this function is called for
2973 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2974 must use sender_host_name and its aliases, looking them up if necessary. */
2976 if (cb->host_name != NULL) /* Explicit host name given */
2977 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2980 /* Host name not given; in principle we need the sender host name and its
2981 aliases. However, for query-style lookups, we do not need the name if the
2982 query does not contain $sender_host_name. From release 4.23, a reference to
2983 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2986 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2988 const uschar *affix;
2989 int partial, affixlen, starflags, id;
2992 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2995 if (id < 0) /* Unknown lookup type */
2997 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2998 search_error_message, ss);
3001 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3006 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3009 case DEFER: return DEFER;
3010 default: return FAIL;
3014 /* Not a query-style lookup; must ensure the host name is present, and then we
3015 do a check on the name and all its aliases. */
3017 if (sender_host_name == NULL)
3019 HDEBUG(D_host_lookup)
3020 debug_printf("sender host name required, to match against %s\n", ss);
3021 if (host_lookup_failed || host_name_lookup() != OK)
3023 *error = string_sprintf("failed to find host name for %s",
3024 sender_host_address);;
3027 host_build_sender_fullhost();
3030 /* Match on the sender host name, using the general matching function */
3032 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3036 case DEFER: return DEFER;
3039 /* If there are aliases, try matching on them. */
3041 aliases = sender_host_aliases;
3042 while (*aliases != NULL)
3044 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3047 case DEFER: return DEFER;
3056 /*************************************************
3057 * Check a specific host matches a host list *
3058 *************************************************/
3060 /* This function is passed a host list containing items in a number of
3061 different formats and the identity of a host. Its job is to determine whether
3062 the given host is in the set of hosts defined by the list. The host name is
3063 passed as a pointer so that it can be looked up if needed and not already
3064 known. This is commonly the case when called from verify_check_host() to check
3065 an incoming connection. When called from elsewhere the host name should usually
3068 This function is now just a front end to match_check_list(), which runs common
3069 code for scanning a list. We pass it the check_host() function to perform a
3073 listptr pointer to the host list
3074 cache_bits pointer to cache for named lists, or NULL
3075 host_name the host name or NULL, implying use sender_host_name and
3076 sender_host_aliases, looking them up if required
3077 host_address the IP address
3078 valueptr if not NULL, data from a lookup is passed back here
3080 Returns: OK if the host is in the defined set
3081 FAIL if the host is not in the defined set,
3082 DEFER if a data lookup deferred (not a host lookup)
3084 If the host name was needed in order to make a comparison, and could not be
3085 determined from the IP address, the result is FAIL unless the item
3086 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3089 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3090 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3093 unsigned int *local_cache_bits = cache_bits;
3094 const uschar *save_host_address = deliver_host_address;
3095 check_host_block cb;
3096 cb.host_name = host_name;
3097 cb.host_address = host_address;
3099 if (valueptr != NULL) *valueptr = NULL;
3101 /* If the host address starts off ::ffff: it is an IPv6 address in
3102 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3105 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3106 host_address + 7 : host_address;
3108 /* During the running of the check, put the IP address into $host_address. In
3109 the case of calls from the smtp transport, it will already be there. However,
3110 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3111 the safe side, any existing setting is preserved, though as I write this
3112 (November 2004) I can't see any cases where it is actually needed. */
3114 deliver_host_address = host_address;
3115 rc = match_check_list(
3116 listptr, /* the list */
3117 0, /* separator character */
3118 &hostlist_anchor, /* anchor pointer */
3119 &local_cache_bits, /* cache pointer */
3120 check_host, /* function for testing */
3121 &cb, /* argument for function */
3122 MCL_HOST, /* type of check */
3123 (host_address == sender_host_address)?
3124 US"host" : host_address, /* text for debugging */
3125 valueptr); /* where to pass back data */
3126 deliver_host_address = save_host_address;
3133 /*************************************************
3134 * Check the given host item matches a list *
3135 *************************************************/
3137 verify_check_given_host(uschar **listptr, host_item *host)
3139 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3142 /*************************************************
3143 * Check the remote host matches a list *
3144 *************************************************/
3146 /* This is a front end to verify_check_this_host(), created because checking
3147 the remote host is a common occurrence. With luck, a good compiler will spot
3148 the tail recursion and optimize it. If there's no host address, this is
3149 command-line SMTP input - check against an empty string for the address.
3152 listptr pointer to the host list
3154 Returns: the yield of verify_check_this_host(),
3155 i.e. OK, FAIL, or DEFER
3159 verify_check_host(uschar **listptr)
3161 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3162 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3169 /*************************************************
3170 * Invert an IP address *
3171 *************************************************/
3173 /* Originally just used for DNS xBL lists, now also used for the
3174 reverse_ip expansion operator.
3177 buffer where to put the answer
3178 address the address to invert
3182 invert_address(uschar *buffer, uschar *address)
3185 uschar *bptr = buffer;
3187 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3188 to the IPv4 part only. */
3190 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3192 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3195 if (host_aton(address, bin) == 1)
3199 for (i = 0; i < 4; i++)
3201 sprintf(CS bptr, "%d.", x & 255);
3202 while (*bptr) bptr++;
3207 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3208 in any DNS black lists, and the format in which they will be looked up is
3209 unknown. This is just a guess. */
3215 for (j = 3; j >= 0; j--)
3218 for (i = 0; i < 8; i++)
3220 sprintf(CS bptr, "%x.", x & 15);
3221 while (*bptr) bptr++;
3228 /* Remove trailing period -- this is needed so that both arbitrary
3229 dnsbl keydomains and inverted addresses may be combined with the
3230 same format string, "%s.%s" */
3237 /*************************************************
3238 * Perform a single dnsbl lookup *
3239 *************************************************/
3241 /* This function is called from verify_check_dnsbl() below. It is also called
3242 recursively from within itself when domain and domain_txt are different
3243 pointers, in order to get the TXT record from the alternate domain.
3246 domain the outer dnsbl domain
3247 domain_txt alternate domain to lookup TXT record on success; when the
3248 same domain is to be used, domain_txt == domain (that is,
3249 the pointers must be identical, not just the text)
3250 keydomain the current keydomain (for debug message)
3251 prepend subdomain to lookup (like keydomain, but
3252 reversed if IP address)
3253 iplist the list of matching IP addresses, or NULL for "any"
3254 bitmask true if bitmask matching is wanted
3255 match_type condition for 'succeed' result
3256 0 => Any RR in iplist (=)
3257 1 => No RR in iplist (!=)
3258 2 => All RRs in iplist (==)
3259 3 => Some RRs not in iplist (!==)
3260 the two bits are defined as MT_NOT and MT_ALL
3261 defer_return what to return for a defer
3263 Returns: OK if lookup succeeded
3268 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3269 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3275 dnsbl_cache_block *cb;
3276 int old_pool = store_pool;
3277 uschar query[256]; /* DNS domain max length */
3279 /* Construct the specific query domainname */
3281 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3283 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3284 "(ignored): %s...", query);
3288 /* Look for this query in the cache. */
3290 if ( (t = tree_search(dnsbl_cache, query))
3291 && (cb = t->data.ptr)->expiry > time(NULL)
3294 /* Previous lookup was cached */
3297 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3300 /* If not cached from a previous lookup, we must do a DNS lookup, and
3301 cache the result in permanent memory. */
3307 store_pool = POOL_PERM;
3311 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3315 { /* Set up a tree entry to cache the lookup */
3316 t = store_get(sizeof(tree_node) + Ustrlen(query));
3317 Ustrcpy(t->name, query);
3318 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3319 (void)tree_insertnode(&dnsbl_cache, t);
3322 /* Do the DNS lookup . */
3324 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3325 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3326 cb->text_set = FALSE;
3330 /* If the lookup succeeded, cache the RHS address. The code allows for
3331 more than one address - this was for complete generality and the possible
3332 use of A6 records. However, A6 records have been reduced to experimental
3333 status (August 2001) and may die out. So they may never get used at all,
3334 let alone in dnsbl records. However, leave the code here, just in case.
3336 Quite apart from one A6 RR generating multiple addresses, there are DNS
3337 lists that return more than one A record, so we must handle multiple
3338 addresses generated in that way as well.
3340 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3341 or some suitably far-future time if none were found. */
3343 if (cb->rc == DNS_SUCCEED)
3346 dns_address **addrp = &(cb->rhs);
3347 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3349 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3351 if (rr->type == T_A)
3353 dns_address *da = dns_address_from_rr(&dnsa, rr);
3357 while (da->next != NULL) da = da->next;
3358 addrp = &(da->next);
3359 if (ttl > rr->ttl) ttl = rr->ttl;
3364 /* If we didn't find any A records, change the return code. This can
3365 happen when there is a CNAME record but there are no A records for what
3368 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3371 cb->expiry = time(NULL)+ttl;
3372 store_pool = old_pool;
3375 /* We now have the result of the DNS lookup, either newly done, or cached
3376 from a previous call. If the lookup succeeded, check against the address
3377 list if there is one. This may be a positive equality list (introduced by
3378 "="), a negative equality list (introduced by "!="), a positive bitmask
3379 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3381 if (cb->rc == DNS_SUCCEED)
3383 dns_address *da = NULL;
3384 uschar *addlist = cb->rhs->address;
3386 /* For A and AAAA records, there may be multiple addresses from multiple
3387 records. For A6 records (currently not expected to be used) there may be
3388 multiple addresses from a single record. */
3390 for (da = cb->rhs->next; da != NULL; da = da->next)
3391 addlist = string_sprintf("%s, %s", addlist, da->address);
3393 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3396 /* Address list check; this can be either for equality, or via a bitmask.
3397 In the latter case, all the bits must match. */
3401 for (da = cb->rhs; da != NULL; da = da->next)
3405 const uschar *ptr = iplist;
3408 /* Handle exact matching */
3412 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3414 if (Ustrcmp(CS da->address, ip) == 0) break;
3418 /* Handle bitmask matching */
3425 /* At present, all known DNS blocking lists use A records, with
3426 IPv4 addresses on the RHS encoding the information they return. I
3427 wonder if this will linger on as the last vestige of IPv4 when IPv6
3428 is ubiquitous? Anyway, for now we use paranoia code to completely
3429 ignore IPv6 addresses. The default mask is 0, which always matches.
3430 We change this only for IPv4 addresses in the list. */
3432 if (host_aton(da->address, address) == 1) mask = address[0];
3434 /* Scan the returned addresses, skipping any that are IPv6 */
3436 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3438 if (host_aton(ip, address) != 1) continue;
3439 if ((address[0] & mask) == address[0]) break;
3445 (a) An IP address in an any ('=') list matched, or
3446 (b) No IP address in an all ('==') list matched
3448 then we're done searching. */
3450 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3453 /* If da == NULL, either
3455 (a) No IP address in an any ('=') list matched, or
3456 (b) An IP address in an all ('==') list didn't match
3458 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3461 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3469 res = US"was no match";
3472 res = US"was an exclude match";
3475 res = US"was an IP address that did not match";
3478 res = US"were no IP addresses that did not match";
3481 debug_printf("=> but we are not accepting this block class because\n");
3482 debug_printf("=> there %s for %s%c%s\n",
3484 ((match_type & MT_ALL) == 0)? "" : "=",
3485 bitmask? '&' : '=', iplist);
3491 /* Either there was no IP list, or the record matched, implying that the
3492 domain is on the list. We now want to find a corresponding TXT record. If an
3493 alternate domain is specified for the TXT record, call this function
3494 recursively to look that up; this has the side effect of re-checking that
3495 there is indeed an A record at the alternate domain. */
3497 if (domain_txt != domain)
3498 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3499 FALSE, match_type, defer_return);
3501 /* If there is no alternate domain, look up a TXT record in the main domain
3502 if it has not previously been cached. */
3506 cb->text_set = TRUE;
3507 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3510 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3512 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3513 if (rr->type == T_TXT) break;
3516 int len = (rr->data)[0];
3517 if (len > 511) len = 127;
3518 store_pool = POOL_PERM;
3519 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3520 store_pool = old_pool;
3525 dnslist_value = addlist;
3526 dnslist_text = cb->text;
3530 /* There was a problem with the DNS lookup */
3532 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3534 log_write(L_dnslist_defer, LOG_MAIN,
3535 "DNS list lookup defer (probably timeout) for %s: %s", query,
3536 (defer_return == OK)? US"assumed in list" :
3537 (defer_return == FAIL)? US"assumed not in list" :
3538 US"returned DEFER");
3539 return defer_return;
3542 /* No entry was found in the DNS; continue for next domain */
3546 debug_printf("DNS lookup for %s failed\n", query);
3547 debug_printf("=> that means %s is not listed at %s\n",
3557 /*************************************************
3558 * Check host against DNS black lists *
3559 *************************************************/
3561 /* This function runs checks against a list of DNS black lists, until one
3562 matches. Each item on the list can be of the form
3564 domain=ip-address/key
3566 The domain is the right-most domain that is used for the query, for example,
3567 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3568 if the DNS lookup returns a matching IP address. Several addresses may be
3569 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3571 If no key is given, what is looked up in the domain is the inverted IP address
3572 of the current client host. If a key is given, it is used to construct the
3573 domain for the lookup. For example:
3575 dsn.rfc-ignorant.org/$sender_address_domain
3577 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3578 then we check for a TXT record for an error message, and if found, save its
3579 value in $dnslist_text. We also cache everything in a tree, to optimize
3582 The TXT record is normally looked up in the same domain as the A record, but
3583 when many lists are combined in a single DNS domain, this will not be a very
3584 specific message. It is possible to specify a different domain for looking up
3585 TXT records; this is given before the main domain, comma-separated. For
3588 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3589 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3591 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3593 Note: an address for testing RBL is 192.203.178.39
3594 Note: an address for testing DUL is 192.203.178.4
3595 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3599 listptr the domain/address/data list
3600 log_msgptr log message on error
3602 Returns: OK successful lookup (i.e. the address is on the list), or
3603 lookup deferred after +include_unknown
3604 FAIL name not found, or no data found for the given type, or
3605 lookup deferred after +exclude_unknown (default)
3606 DEFER lookup failure, if +defer_unknown was set
3610 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3613 int defer_return = FAIL;
3614 const uschar *list = *listptr;
3617 uschar buffer[1024];
3618 uschar revadd[128]; /* Long enough for IPv6 address */
3620 /* Indicate that the inverted IP address is not yet set up */
3624 /* In case this is the first time the DNS resolver is being used. */
3626 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3628 /* Loop through all the domains supplied, until something matches */
3630 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3633 BOOL bitmask = FALSE;
3640 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3642 /* Deal with special values that change the behaviour on defer */
3644 if (domain[0] == '+')
3646 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3647 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3648 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3650 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3655 /* See if there's explicit data to be looked up */
3657 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3659 /* See if there's a list of addresses supplied after the domain name. This is
3660 introduced by an = or a & character; if preceded by = we require all matches
3661 and if preceded by ! we invert the result. */
3663 if (!(iplist = Ustrchr(domain, '=')))
3666 iplist = Ustrchr(domain, '&');
3669 if (iplist) /* Found either = or & */
3671 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3673 match_type |= MT_NOT;
3677 *iplist++ = 0; /* Terminate domain, move on */
3679 /* If we found = (bitmask == FALSE), check for == or =& */
3681 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3683 bitmask = *iplist++ == '&';
3684 match_type |= MT_ALL;
3689 /* If there is a comma in the domain, it indicates that a second domain for
3690 looking up TXT records is provided, before the main domain. Otherwise we must
3691 set domain_txt == domain. */
3693 domain_txt = domain;
3694 comma = Ustrchr(domain, ',');
3701 /* Check that what we have left is a sensible domain name. There is no reason
3702 why these domains should in fact use the same syntax as hosts and email
3703 domains, but in practice they seem to. However, there is little point in
3704 actually causing an error here, because that would no doubt hold up incoming
3705 mail. Instead, I'll just log it. */
3707 for (s = domain; *s != 0; s++)
3709 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3711 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3712 "strange characters - is this right?", domain);
3717 /* Check the alternate domain if present */
3719 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3721 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3723 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3724 "strange characters - is this right?", domain_txt);
3729 /* If there is no key string, construct the query by adding the domain name
3730 onto the inverted host address, and perform a single DNS lookup. */
3734 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3736 *log_msgptr = string_sprintf
3737 ("cannot test auto-keyed dnslists condition in %s ACL",
3738 acl_wherenames[where]);
3741 if (sender_host_address == NULL) return FAIL; /* can never match */
3742 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3743 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3744 iplist, bitmask, match_type, defer_return);
3747 dnslist_domain = string_copy(domain_txt);
3748 dnslist_matched = string_copy(sender_host_address);
3749 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3750 sender_host_address, dnslist_domain);
3752 if (rc != FAIL) return rc; /* OK or DEFER */
3755 /* If there is a key string, it can be a list of domains or IP addresses to
3756 be concatenated with the main domain. */
3763 uschar keybuffer[256];
3764 uschar keyrevadd[128];
3766 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3767 sizeof(keybuffer))) != NULL)
3769 uschar *prepend = keydomain;
3771 if (string_is_ip_address(keydomain, NULL) != 0)
3773 invert_address(keyrevadd, keydomain);
3774 prepend = keyrevadd;
3777 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3778 bitmask, match_type, defer_return);
3782 dnslist_domain = string_copy(domain_txt);
3783 dnslist_matched = string_copy(keydomain);
3784 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3785 keydomain, dnslist_domain);
3789 /* If the lookup deferred, remember this fact. We keep trying the rest
3790 of the list to see if we get a useful result, and if we don't, we return
3791 DEFER at the end. */
3793 if (rc == DEFER) defer = TRUE;
3794 } /* continue with next keystring domain/address */
3796 if (defer) return DEFER;
3798 } /* continue with next dnsdb outer domain */
3805 /* End of verify.c */