1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
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);
764 if (smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0)
765 switch(addr->transport_return)
768 new_domain_record.random_result = ccache_accept;
771 new_domain_record.random_result = ccache_reject;
773 /* Between each check, issue RSET, because some servers accept only
774 one recipient after MAIL FROM:<>. */
777 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
778 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
783 debug_printf("problem after random/rset/mfrom; reopen conn\n");
784 random_local_part = NULL;
786 tls_close(FALSE, TRUE);
788 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
789 (void)close(sx.inblock.sock);
790 sx.inblock.sock = sx.outblock.sock = -1;
791 #ifndef DISABLE_EVENT
792 (void) event_raise(addr->transport->event_action,
793 US"tcp:close", NULL);
795 goto tls_retry_connection;
798 /* If accepted, we aren't going to do any further tests below.
799 Otherwise, cache a real negative response, and get back to the right
800 state to send RCPT. Unless there's some problem such as a dropped
801 connection, we expect to succeed, because the commands succeeded above.
802 However, some servers drop the connection after responding to an
803 invalid recipient, so on (any) error we drop and remake the connection.
805 XXX could we add another flag to the context, and have the common
806 code emit the RSET too? Even pipelined after the RCPT...
807 Then the main-verify call could use it if there's to be a subsequent
809 The sync_responses() would need to be taught about it and we'd
810 need another return code filtering out to here.
812 Remember when we last did a random test
815 new_domain_record.random_stamp = time(NULL);
817 /* Re-setup for main verify, or for the error message when failing */
818 addr->address = main_address;
819 addr->transport_return = PENDING_DEFER;
820 sx.first_addr = sx.sync_addr = addr;
823 sx.completed_addr = FALSE;
828 /* Main verify. If the host is accepting all local parts, as determined
829 by the "random" check, we don't need to waste time doing any further
835 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
837 case 0: switch(addr->transport_return) /* ok so far */
839 case PENDING_OK: done = TRUE;
840 new_address_record.result = ccache_accept;
842 case FAIL: done = TRUE;
844 *failure_ptr = US"recipient";
845 new_address_record.result = ccache_reject;
851 case -1: /* MAIL response error */
852 *failure_ptr = US"mail";
853 if (errno == 0 && sx.buffer[0] == '5')
855 setflag(addr, af_verify_nsfail);
856 if (from_address[0] == 0)
857 new_domain_record.result = ccache_reject_mfnull;
860 /* non-MAIL read i/o error */
861 /* non-MAIL response timeout */
862 /* internal error; channel still usable */
863 default: break; /* transmit failed */
867 addr->auth_sndr = client_authenticated_sender;
869 deliver_host = deliver_host_address = NULL;
870 deliver_domain = save_deliver_domain;
872 /* Do postmaster check if requested; if a full check is required, we
873 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
875 if (done && pm_mailfrom)
877 /* Could possibly shift before main verify, just above, and be ok
878 for cutthrough. But no way to handle a subsequent rcpt, so just
880 cancel_cutthrough_connection("postmaster verify");
881 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
883 done = smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0
884 && smtp_read_response(&sx.inblock, sx.buffer,
885 sizeof(sx.buffer), '2', callout);
889 uschar * main_address = addr->address;
891 /*XXX oops, affixes */
892 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
893 addr->transport_return = PENDING_DEFER;
895 sx.from_addr = pm_mailfrom;
896 sx.first_addr = sx.sync_addr = addr;
899 sx.completed_addr = FALSE;
901 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
902 && addr->transport_return == PENDING_OK
906 done = (options & vopt_callout_fullpm) != 0
907 && smtp_write_command(&sx.outblock, FALSE,
908 "RCPT TO:<postmaster>\r\n") >= 0
909 && smtp_read_response(&sx.inblock, sx.buffer,
910 sizeof(sx.buffer), '2', callout);
912 /* Sort out the cache record */
914 new_domain_record.postmaster_stamp = time(NULL);
917 new_domain_record.postmaster_result = ccache_accept;
918 else if (errno == 0 && sx.buffer[0] == '5')
920 *failure_ptr = US"postmaster";
921 setflag(addr, af_verify_pmfail);
922 new_domain_record.postmaster_result = ccache_reject;
925 addr->address = main_address;
928 /* For any failure of the main check, other than a negative response, we just
929 close the connection and carry on. We can identify a negative response by the
930 fact that errno is zero. For I/O errors it will be non-zero
932 Set up different error texts for logging and for sending back to the caller
933 as an SMTP response. Log in all cases, using a one-line format. For sender
934 callouts, give a full response to the caller, but for recipient callouts,
935 don't give the IP address because this may be an internal host whose identity
936 is not to be widely broadcast. */
942 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
943 sx.send_quit = FALSE;
949 extern int acl_where; /* src/acl.c */
951 addr->message = string_sprintf(
952 "response to \"EHLO\" did not include SMTPUTF8");
953 addr->user_message = acl_where == ACL_WHERE_RCPT
954 ? US"533 no support for internationalised mailbox name"
955 : US"550 mailbox unavailable";
962 sx.send_quit = FALSE;
966 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
968 /*XXX test here is ugly; seem to have a split of responsibility for
969 building this message. Need to reationalise. Where is it done
970 before here, and when not?
971 Not == 5xx resp to MAIL on main-verify
973 if (!addr->message) addr->message =
974 string_sprintf("response to \"%s\" was: %s",
975 big_buffer, string_printing(sx.buffer));
977 addr->user_message = options & vopt_is_recipient
978 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
979 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
980 host->address, big_buffer, sx.buffer);
982 /* Hard rejection ends the process */
984 if (sx.buffer[0] == '5') /* Address rejected */
992 /* End the SMTP conversation and close the connection. */
994 /* Cutthrough - on a successful connect and recipient-verify with
995 use-sender and we are 1st rcpt and have no cutthrough conn so far
996 here is where we want to leave the conn open */
997 if ( cutthrough.delivery
1001 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1002 == vopt_callout_recipsender
1003 && !random_local_part
1005 && cutthrough.fd < 0
1009 HDEBUG(D_acl|D_v) debug_printf("holding verify callout open for cutthrough delivery\n");
1011 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1012 cutthrough.nrcpt = 1;
1013 cutthrough.interface = interface;
1014 cutthrough.host = *host;
1015 cutthrough.addr = *addr; /* Save the address_item for later logging */
1016 cutthrough.addr.next = NULL;
1017 cutthrough.addr.host_used = &cutthrough.host;
1019 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1021 ctblock.buffer = ctbuffer;
1022 ctblock.buffersize = sizeof(ctbuffer);
1023 ctblock.ptr = ctbuffer;
1024 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1025 ctblock.sock = cutthrough.fd;
1029 /* Ensure no cutthrough on multiple address verifies */
1030 if (options & vopt_callout_recipsender)
1031 cancel_cutthrough_connection("not usable for cutthrough");
1034 (void) smtp_write_command(&sx.outblock, FALSE, "QUIT\r\n");
1036 /* Wait a short time for response, and discard it */
1037 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1041 if (sx.inblock.sock >= 0)
1044 tls_close(FALSE, TRUE);
1046 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1047 (void)close(sx.inblock.sock);
1048 sx.inblock.sock = sx.outblock.sock = -1;
1049 #ifndef DISABLE_EVENT
1050 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1055 if (!done || yield != OK)
1056 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1058 } /* Loop through all hosts, while !done */
1061 /* If we get here with done == TRUE, a successful callout happened, and yield
1062 will be set OK or FAIL according to the response to the RCPT command.
1063 Otherwise, we looped through the hosts but couldn't complete the business.
1064 However, there may be domain-specific information to cache in both cases. */
1066 if (!(options & vopt_callout_no_cache))
1067 cache_callout_write(&new_domain_record, addr->domain,
1068 done, &new_address_record, address_key);
1070 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1071 temporary error. If there was only one host, and a response was received, leave
1072 it alone if supplying details. Otherwise, give a generic response. */
1076 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1077 options & vopt_is_recipient ? "recipient" : "sender");
1080 addr->message = host_list->next || !addr->message
1081 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1083 addr->user_message = smtp_return_error_details
1084 ? string_sprintf("%s for <%s>.\n"
1085 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1086 "they may be permanently unreachable from this server. In the latter case,\n%s",
1087 dullmsg, addr->address,
1088 options & vopt_is_recipient
1089 ? "the address will never be accepted."
1090 : "you need to change the address or create an MX record for its domain\n"
1091 "if it is supposed to be generally accessible from the Internet.\n"
1092 "Talk to your mail administrator for details.")
1095 /* Force a specific error code */
1097 addr->basic_errno = ERRNO_CALLOUTDEFER;
1100 /* Come here from within the cache-reading code on fast-track exit. */
1103 tls_modify_variables(&tls_in);
1109 /* Called after recipient-acl to get a cutthrough connection open when
1110 one was requested and a recipient-verify wasn't subsequently done.
1113 open_cutthrough_connection( address_item * addr )
1118 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1119 /* We must use a copy of the address for verification, because it might
1123 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1124 rcpt_count > 1 ? "more" : "start");
1125 rc = verify_address(&addr2, NULL,
1126 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1127 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1129 addr->message = addr2.message;
1130 addr->user_message = addr2.user_message;
1131 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1137 /* Send given number of bytes from the buffer */
1139 cutthrough_send(int n)
1141 if(cutthrough.fd < 0)
1146 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1148 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1151 transport_count += n;
1152 ctblock.ptr= ctblock.buffer;
1156 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1163 _cutthrough_puts(uschar * cp, int n)
1167 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1168 if(!cutthrough_send(ctblock.buffersize))
1171 *ctblock.ptr++ = *cp++;
1176 /* Buffered output of counted data block. Return boolean success */
1178 cutthrough_puts(uschar * cp, int n)
1180 if (cutthrough.fd < 0) return TRUE;
1181 if (_cutthrough_puts(cp, n)) return TRUE;
1182 cancel_cutthrough_connection("transmit failed");
1188 _cutthrough_flush_send(void)
1190 int n= ctblock.ptr-ctblock.buffer;
1193 if(!cutthrough_send(n))
1199 /* Send out any bufferred output. Return boolean success. */
1201 cutthrough_flush_send(void)
1203 if (_cutthrough_flush_send()) return TRUE;
1204 cancel_cutthrough_connection("transmit failed");
1210 cutthrough_put_nl(void)
1212 return cutthrough_puts(US"\r\n", 2);
1216 /* Get and check response from cutthrough target */
1218 cutthrough_response(char expect, uschar ** copy, int timeout)
1220 smtp_inblock inblock;
1221 uschar inbuffer[4096];
1222 uschar responsebuffer[4096];
1224 inblock.buffer = inbuffer;
1225 inblock.buffersize = sizeof(inbuffer);
1226 inblock.ptr = inbuffer;
1227 inblock.ptrend = inbuffer;
1228 inblock.sock = cutthrough.fd;
1229 /* this relies on (inblock.sock == tls_out.active) */
1230 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1231 cancel_cutthrough_connection("target timeout on read");
1236 *copy = cp = string_copy(responsebuffer);
1237 /* Trim the trailing end of line */
1238 cp += Ustrlen(responsebuffer);
1239 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1240 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1243 return responsebuffer[0];
1247 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1249 cutthrough_predata(void)
1251 if(cutthrough.fd < 0)
1254 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1255 cutthrough_puts(US"DATA\r\n", 6);
1256 cutthrough_flush_send();
1258 /* Assume nothing buffered. If it was it gets ignored. */
1259 return cutthrough_response('3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1263 /* fd and tctx args only to match write_chunk() */
1265 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1268 while(s && (s2 = Ustrchr(s, '\n')))
1270 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1278 /* Buffered send of headers. Return success boolean. */
1279 /* Expands newlines to wire format (CR,NL). */
1280 /* Also sends header-terminating blank line. */
1282 cutthrough_headers_send(void)
1286 if(cutthrough.fd < 0)
1289 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1290 but having a separate buffered-output function (for now)
1292 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1294 tctx.tblock = cutthrough.addr.transport;
1295 tctx.addr = &cutthrough.addr;
1296 tctx.check_string = US".";
1297 tctx.escape_string = US"..";
1298 tctx.options = topt_use_crlf;
1300 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1303 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1309 close_cutthrough_connection(const char * why)
1311 if(cutthrough.fd >= 0)
1313 /* We could be sending this after a bunch of data, but that is ok as
1314 the only way to cancel the transfer in dataphase is to drop the tcp
1315 conn before the final dot.
1317 ctblock.ptr = ctbuffer;
1318 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1319 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1320 _cutthrough_flush_send();
1322 /* Wait a short time for response, and discard it */
1323 cutthrough_response('2', NULL, 1);
1326 tls_close(FALSE, TRUE);
1328 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1329 (void)close(cutthrough.fd);
1331 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1333 ctblock.ptr = ctbuffer;
1337 cancel_cutthrough_connection(const char * why)
1339 close_cutthrough_connection(why);
1340 cutthrough.delivery = FALSE;
1346 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1347 Log an OK response as a transmission.
1348 Close the connection.
1349 Return smtp response-class digit.
1352 cutthrough_finaldot(void)
1355 address_item * addr;
1356 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1358 /* Assume data finshed with new-line */
1359 if( !cutthrough_puts(US".", 1)
1360 || !cutthrough_put_nl()
1361 || !cutthrough_flush_send()
1363 return cutthrough.addr.message;
1365 res = cutthrough_response('2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1366 for (addr = &cutthrough.addr; addr; addr = addr->next)
1368 addr->message = cutthrough.addr.message;
1372 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1373 close_cutthrough_connection("delivered");
1377 delivery_log(LOG_MAIN, addr, 0,
1378 US"tmp-reject from cutthrough after DATA:");
1382 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1383 US"rejected after DATA:");
1390 return cutthrough.addr.message;
1395 /*************************************************
1396 * Copy error to toplevel address *
1397 *************************************************/
1399 /* This function is used when a verify fails or defers, to ensure that the
1400 failure or defer information is in the original toplevel address. This applies
1401 when an address is redirected to a single new address, and the failure or
1402 deferral happens to the child address.
1405 vaddr the verify address item
1406 addr the final address item
1409 Returns: the value of YIELD
1413 copy_error(address_item *vaddr, address_item *addr, int yield)
1417 vaddr->message = addr->message;
1418 vaddr->user_message = addr->user_message;
1419 vaddr->basic_errno = addr->basic_errno;
1420 vaddr->more_errno = addr->more_errno;
1421 vaddr->prop.address_data = addr->prop.address_data;
1422 copyflag(vaddr, addr, af_pass_message);
1430 /**************************************************
1431 * printf that automatically handles TLS if needed *
1432 ***************************************************/
1434 /* This function is used by verify_address() as a substitute for all fprintf()
1435 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1436 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1437 that assumes that we always use the smtp_out FILE* when not using TLS or the
1438 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1439 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1443 f the candidate FILE* to write to
1444 format format string
1445 ... optional arguments
1451 static void PRINTF_FUNCTION(2,3)
1452 respond_printf(FILE *f, const char *format, ...)
1456 va_start(ap, format);
1457 if (smtp_out && (f == smtp_out))
1458 smtp_vprintf(format, ap);
1460 vfprintf(f, format, ap);
1466 /*************************************************
1467 * Verify an email address *
1468 *************************************************/
1470 /* This function is used both for verification (-bv and at other times) and
1471 address testing (-bt), which is indicated by address_test_mode being set.
1474 vaddr contains the address to verify; the next field in this block
1476 f if not NULL, write the result to this file
1477 options various option bits:
1478 vopt_fake_sender => this sender verify is not for the real
1479 sender (it was verify=sender=xxxx or an address from a
1480 header line) - rewriting must not change sender_address
1481 vopt_is_recipient => this is a recipient address, otherwise
1482 it's a sender address - this affects qualification and
1483 rewriting and messages from callouts
1484 vopt_qualify => qualify an unqualified address; else error
1485 vopt_expn => called from SMTP EXPN command
1486 vopt_success_on_redirect => when a new address is generated
1487 the verification instantly succeeds
1489 These ones are used by do_callout() -- the options variable
1492 vopt_callout_fullpm => if postmaster check, do full one
1493 vopt_callout_no_cache => don't use callout cache
1494 vopt_callout_random => do the "random" thing
1495 vopt_callout_recipsender => use real sender for recipient
1496 vopt_callout_recippmaster => use postmaster for recipient
1498 callout if > 0, specifies that callout is required, and gives timeout
1499 for individual commands
1500 callout_overall if > 0, gives overall timeout for the callout function;
1501 if < 0, a default is used (see do_callout())
1502 callout_connect the connection timeout for callouts
1503 se_mailfrom when callout is requested to verify a sender, use this
1504 in MAIL FROM; NULL => ""
1505 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1506 thing and use this as the sender address (may be "")
1508 routed if not NULL, set TRUE if routing succeeded, so we can
1509 distinguish between routing failed and callout failed
1511 Returns: OK address verified
1512 FAIL address failed to verify
1513 DEFER can't tell at present
1517 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1518 int callout_overall, int callout_connect, uschar *se_mailfrom,
1519 uschar *pm_mailfrom, BOOL *routed)
1522 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1523 BOOL expn = (options & vopt_expn) != 0;
1524 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1527 int verify_type = expn? v_expn :
1528 address_test_mode? v_none :
1529 options & vopt_is_recipient? v_recipient : v_sender;
1530 address_item *addr_list;
1531 address_item *addr_new = NULL;
1532 address_item *addr_remote = NULL;
1533 address_item *addr_local = NULL;
1534 address_item *addr_succeed = NULL;
1535 uschar **failure_ptr = options & vopt_is_recipient
1536 ? &recipient_verify_failure : &sender_verify_failure;
1537 uschar *ko_prefix, *cr;
1538 uschar *address = vaddr->address;
1539 uschar *save_sender;
1540 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1542 /* Clear, just in case */
1544 *failure_ptr = NULL;
1546 /* Set up a prefix and suffix for error message which allow us to use the same
1547 output statements both in EXPN mode (where an SMTP response is needed) and when
1548 debugging with an output file. */
1552 ko_prefix = US"553 ";
1555 else ko_prefix = cr = US"";
1557 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1559 if (parse_find_at(address) == NULL)
1561 if ((options & vopt_qualify) == 0)
1564 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1565 ko_prefix, address, cr);
1566 *failure_ptr = US"qualify";
1569 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1574 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1575 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1578 /* Rewrite and report on it. Clear the domain and local part caches - these
1579 may have been set by domains and local part tests during an ACL. */
1581 if (global_rewrite_rules != NULL)
1583 uschar *old = address;
1584 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1585 global_rewrite_rules, rewrite_existflags);
1588 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1589 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1590 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1594 /* If this is the real sender address, we must update sender_address at
1595 this point, because it may be referred to in the routers. */
1597 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1598 sender_address = address;
1600 /* If the address was rewritten to <> no verification can be done, and we have
1601 to return OK. This rewriting is permitted only for sender addresses; for other
1602 addresses, such rewriting fails. */
1604 if (address[0] == 0) return OK;
1606 /* Flip the legacy TLS-related variables over to the outbound set in case
1607 they're used in the context of a transport used by verification. Reset them
1608 at exit from this routine (so no returns allowed from here on). */
1610 tls_modify_variables(&tls_out);
1612 /* Save a copy of the sender address for re-instating if we change it to <>
1613 while verifying a sender address (a nice bit of self-reference there). */
1615 save_sender = sender_address;
1617 /* Observability variable for router/transport use */
1619 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1621 /* Update the address structure with the possibly qualified and rewritten
1622 address. Set it up as the starting address on the chain of new addresses. */
1624 vaddr->address = address;
1627 /* We need a loop, because an address can generate new addresses. We must also
1628 cope with generated pipes and files at the top level. (See also the code and
1629 comment in deliver.c.) However, it is usually the case that the router for
1630 user's .forward files has its verify flag turned off.
1632 If an address generates more than one child, the loop is used only when
1633 full_info is set, and this can only be set locally. Remote enquiries just get
1634 information about the top level address, not anything that it generated. */
1639 address_item *addr = addr_new;
1641 addr_new = addr->next;
1646 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1647 debug_printf("Considering %s\n", addr->address);
1650 /* Handle generated pipe, file or reply addresses. We don't get these
1651 when handling EXPN, as it does only one level of expansion. */
1653 if (testflag(addr, af_pfr))
1660 if (addr->address[0] == '>')
1662 allow = testflag(addr, af_allow_reply);
1663 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1667 allow = (addr->address[0] == '|')?
1668 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1669 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1672 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1673 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1674 "%s\n", addr->message);
1676 fprintf(f, "\n transport = %s\n", addr->transport->name);
1678 fprintf(f, " *** forbidden ***\n");
1683 /* Just in case some router parameter refers to it. */
1685 return_path = addr->prop.errors_address
1686 ? addr->prop.errors_address : sender_address;
1688 /* Split the address into domain and local part, handling the %-hack if
1689 necessary, and then route it. While routing a sender address, set
1690 $sender_address to <> because that is what it will be if we were trying to
1691 send a bounce to the sender. */
1693 if (routed) *routed = FALSE;
1694 if ((rc = deliver_split_address(addr)) == OK)
1696 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1697 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1698 &addr_succeed, verify_type);
1699 sender_address = save_sender; /* Put back the real sender */
1702 /* If routing an address succeeded, set the flag that remembers, for use when
1703 an ACL cached a sender verify (in case a callout fails). Then if routing set
1704 up a list of hosts or the transport has a host list, and the callout option
1705 is set, and we aren't in a host checking run, do the callout verification,
1706 and set another flag that notes that a callout happened. */
1710 if (routed) *routed = TRUE;
1713 transport_instance * tp;
1714 host_item * host_list = addr->host_list;
1716 /* Make up some data for use in the case where there is no remote
1719 transport_feedback tf = {
1720 NULL, /* interface (=> any) */
1721 US"smtp", /* port */
1722 US"smtp", /* protocol */
1724 US"$smtp_active_hostname", /* helo_data */
1725 FALSE, /* hosts_override */
1726 FALSE, /* hosts_randomize */
1727 FALSE, /* gethostbyname */
1728 TRUE, /* qualify_single */
1729 FALSE /* search_parents */
1732 /* If verification yielded a remote transport, we want to use that
1733 transport's options, so as to mimic what would happen if we were really
1734 sending a message to this address. */
1736 if ((tp = addr->transport) && !tp->info->local)
1738 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1740 /* If the transport has hosts and the router does not, or if the
1741 transport is configured to override the router's hosts, we must build a
1742 host list of the transport's hosts, and find the IP addresses */
1744 if (tf.hosts && (!host_list || tf.hosts_override))
1747 const uschar *save_deliver_domain = deliver_domain;
1748 uschar *save_deliver_localpart = deliver_localpart;
1750 host_list = NULL; /* Ignore the router's hosts */
1752 deliver_domain = addr->domain;
1753 deliver_localpart = addr->local_part;
1754 s = expand_string(tf.hosts);
1755 deliver_domain = save_deliver_domain;
1756 deliver_localpart = save_deliver_localpart;
1760 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1761 "\"%s\" in %s transport for callout: %s", tf.hosts,
1762 tp->name, expand_string_message);
1767 host_item *host, *nexthost;
1768 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1770 /* Just ignore failures to find a host address. If we don't manage
1771 to find any addresses, the callout will defer. Note that more than
1772 one address may be found for a single host, which will result in
1773 additional host items being inserted into the chain. Hence we must
1774 save the next host first. */
1776 flags = HOST_FIND_BY_A;
1777 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1778 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1780 for (host = host_list; host; host = nexthost)
1782 nexthost = host->next;
1783 if (tf.gethostbyname ||
1784 string_is_ip_address(host->name, NULL) != 0)
1785 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1788 dnssec_domains * dnssec_domains = NULL;
1789 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1791 smtp_transport_options_block * ob =
1792 (smtp_transport_options_block *) tp->options_block;
1793 dnssec_domains = &ob->dnssec;
1796 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1797 dnssec_domains, NULL, NULL);
1804 /* Can only do a callout if we have at least one host! If the callout
1805 fails, it will have set ${sender,recipient}_verify_failure. */
1809 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1810 if (host_checking && !host_checking_callout)
1813 debug_printf("... callout omitted by default when host testing\n"
1814 "(Use -bhc if you want the callouts to happen.)\n");
1819 deliver_set_expansions(addr);
1821 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1822 callout_connect, options, se_mailfrom, pm_mailfrom);
1827 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1828 "transport provided a host list\n");
1833 /* Otherwise, any failure is a routing failure */
1835 else *failure_ptr = US"route";
1837 /* A router may return REROUTED if it has set up a child address as a result
1838 of a change of domain name (typically from widening). In this case we always
1839 want to continue to verify the new child. */
1841 if (rc == REROUTED) continue;
1843 /* Handle hard failures */
1850 address_item *p = addr->parent;
1852 respond_printf(f, "%s%s %s", ko_prefix,
1853 full_info ? addr->address : address,
1854 address_test_mode ? "is undeliverable" : "failed to verify");
1855 if (!expn && admin_user)
1857 if (addr->basic_errno > 0)
1858 respond_printf(f, ": %s", strerror(addr->basic_errno));
1860 respond_printf(f, ": %s", addr->message);
1863 /* Show parents iff doing full info */
1865 if (full_info) while (p)
1867 respond_printf(f, "%s\n <-- %s", cr, p->address);
1870 respond_printf(f, "%s\n", cr);
1872 cancel_cutthrough_connection("routing hard fail");
1876 yield = copy_error(vaddr, addr, FAIL);
1884 else if (rc == DEFER)
1889 address_item *p = addr->parent;
1890 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1891 full_info? addr->address : address);
1892 if (!expn && admin_user)
1894 if (addr->basic_errno > 0)
1895 respond_printf(f, ": %s", strerror(addr->basic_errno));
1897 respond_printf(f, ": %s", addr->message);
1898 else if (addr->basic_errno <= 0)
1899 respond_printf(f, ": unknown error");
1902 /* Show parents iff doing full info */
1904 if (full_info) while (p)
1906 respond_printf(f, "%s\n <-- %s", cr, p->address);
1909 respond_printf(f, "%s\n", cr);
1911 cancel_cutthrough_connection("routing soft fail");
1915 yield = copy_error(vaddr, addr, DEFER);
1918 if (yield == OK) yield = DEFER;
1921 /* If we are handling EXPN, we do not want to continue to route beyond
1922 the top level (whose address is in "address"). */
1926 uschar *ok_prefix = US"250-";
1929 if (!addr_local && !addr_remote)
1930 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1932 respond_printf(f, "250 <%s>\r\n", address);
1936 address_item *addr2 = addr_new;
1937 addr_new = addr2->next;
1938 if (!addr_new) ok_prefix = US"250 ";
1939 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1945 /* Successful routing other than EXPN. */
1949 /* Handle successful routing when short info wanted. Otherwise continue for
1950 other (generated) addresses. Short info is the operational case. Full info
1951 can be requested only when debug_selector != 0 and a file is supplied.
1953 There is a conflict between the use of aliasing as an alternate email
1954 address, and as a sort of mailing list. If an alias turns the incoming
1955 address into just one address (e.g. J.Caesar->jc44) you may well want to
1956 carry on verifying the generated address to ensure it is valid when
1957 checking incoming mail. If aliasing generates multiple addresses, you
1958 probably don't want to do this. Exim therefore treats the generation of
1959 just a single new address as a special case, and continues on to verify the
1960 generated address. */
1962 if ( !full_info /* Stop if short info wanted AND */
1963 && ( ( !addr_new /* No new address OR */
1964 || addr_new->next /* More than one new address OR */
1965 || testflag(addr_new, af_pfr) /* New address is pfr */
1968 ( addr_new /* At least one new address AND */
1969 && success_on_redirect /* success_on_redirect is set */
1973 if (f) fprintf(f, "%s %s\n",
1974 address, address_test_mode ? "is deliverable" : "verified");
1976 /* If we have carried on to verify a child address, we want the value
1977 of $address_data to be that of the child */
1979 vaddr->prop.address_data = addr->prop.address_data;
1981 /* If stopped because more than one new address, cannot cutthrough */
1983 if (addr_new && addr_new->next)
1984 cancel_cutthrough_connection("multiple addresses from routing");
1990 } /* Loop for generated addresses */
1992 /* Display the full results of the successful routing, including any generated
1993 addresses. Control gets here only when full_info is set, which requires f not
1994 to be NULL, and this occurs only when a top-level verify is called with the
1995 debugging switch on.
1997 If there are no local and no remote addresses, and there were no pipes, files,
1998 or autoreplies, and there were no errors or deferments, the message is to be
1999 discarded, usually because of the use of :blackhole: in an alias file. */
2001 if (allok && !addr_local && !addr_remote)
2003 fprintf(f, "mail to %s is discarded\n", address);
2007 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2010 address_item *addr = addr_list;
2011 address_item *p = addr->parent;
2012 transport_instance * tp = addr->transport;
2014 addr_list = addr->next;
2016 fprintf(f, "%s", CS addr->address);
2017 #ifdef EXPERIMENTAL_SRS
2018 if(addr->prop.srs_sender)
2019 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2022 /* If the address is a duplicate, show something about it. */
2024 if (!testflag(addr, af_pfr))
2027 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2028 fprintf(f, " [duplicate, would not be delivered]");
2029 else tree_add_duplicate(addr->unique, addr);
2032 /* Now show its parents */
2034 for (p = addr->parent; p; p = p->parent)
2035 fprintf(f, "\n <-- %s", p->address);
2038 /* Show router, and transport */
2040 fprintf(f, "router = %s, transport = %s\n",
2041 addr->router->name, tp ? tp->name : US"unset");
2043 /* Show any hosts that are set up by a router unless the transport
2044 is going to override them; fiddle a bit to get a nice format. */
2046 if (addr->host_list && tp && !tp->overrides_hosts)
2051 for (h = addr->host_list; h; h = h->next)
2052 { /* get max lengths of host names, addrs */
2053 int len = Ustrlen(h->name);
2054 if (len > maxlen) maxlen = len;
2055 len = h->address ? Ustrlen(h->address) : 7;
2056 if (len > maxaddlen) maxaddlen = len;
2058 for (h = addr->host_list; h; h = h->next)
2060 fprintf(f, " host %-*s ", maxlen, h->name);
2063 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2064 else if (tp->info->local)
2065 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2067 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2069 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2070 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2071 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2072 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2078 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2079 the -bv or -bt case). */
2083 tls_modify_variables(&tls_in);
2091 /*************************************************
2092 * Check headers for syntax errors *
2093 *************************************************/
2095 /* This function checks those header lines that contain addresses, and verifies
2096 that all the addresses therein are syntactially correct.
2099 msgptr where to put an error message
2106 verify_check_headers(uschar **msgptr)
2112 for (h = header_list; h != NULL && yield == OK; h = h->next)
2114 if (h->type != htype_from &&
2115 h->type != htype_reply_to &&
2116 h->type != htype_sender &&
2117 h->type != htype_to &&
2118 h->type != htype_cc &&
2119 h->type != htype_bcc)
2122 colon = Ustrchr(h->text, ':');
2124 while (isspace(*s)) s++;
2126 /* Loop for multiple addresses in the header, enabling group syntax. Note
2127 that we have to reset this after the header has been scanned. */
2129 parse_allow_group = TRUE;
2133 uschar *ss = parse_find_address_end(s, FALSE);
2134 uschar *recipient, *errmess;
2135 int terminator = *ss;
2136 int start, end, domain;
2138 /* Temporarily terminate the string at this point, and extract the
2139 operative address within, allowing group syntax. */
2142 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2145 /* Permit an unqualified address only if the message is local, or if the
2146 sending host is configured to be permitted to send them. */
2148 if (recipient != NULL && domain == 0)
2150 if (h->type == htype_from || h->type == htype_sender)
2152 if (!allow_unqualified_sender) recipient = NULL;
2156 if (!allow_unqualified_recipient) recipient = NULL;
2158 if (recipient == NULL) errmess = US"unqualified address not permitted";
2161 /* It's an error if no address could be extracted, except for the special
2162 case of an empty address. */
2164 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2166 uschar *verb = US"is";
2171 /* Arrange not to include any white space at the end in the
2172 error message or the header name. */
2174 while (t > s && isspace(t[-1])) t--;
2175 while (tt > h->text && isspace(tt[-1])) tt--;
2177 /* Add the address that failed to the error message, since in a
2178 header with very many addresses it is sometimes hard to spot
2179 which one is at fault. However, limit the amount of address to
2180 quote - cases have been seen where, for example, a missing double
2181 quote in a humungous To: header creates an "address" that is longer
2182 than string_sprintf can handle. */
2191 /* deconst cast ok as we're passing a non-const to string_printing() */
2192 *msgptr = US string_printing(
2193 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2194 errmess, tt - h->text, h->text, verb, len, s));
2197 break; /* Out of address loop */
2200 /* Advance to the next address */
2202 s = ss + (terminator? 1:0);
2203 while (isspace(*s)) s++;
2204 } /* Next address */
2206 parse_allow_group = FALSE;
2207 parse_found_group = FALSE;
2208 } /* Next header unless yield has been set FALSE */
2214 /*************************************************
2215 * Check header names for 8-bit characters *
2216 *************************************************/
2218 /* This function checks for invalid characters in header names. See
2219 RFC 5322, 2.2. and RFC 6532, 3.
2222 msgptr where to put an error message
2229 verify_check_header_names_ascii(uschar **msgptr)
2234 for (h = header_list; h != NULL; h = h->next)
2236 colon = Ustrchr(h->text, ':');
2237 for(s = h->text; s < colon; s++)
2239 if ((*s < 33) || (*s > 126))
2241 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2242 colon - h->text, h->text);
2250 /*************************************************
2251 * Check for blind recipients *
2252 *************************************************/
2254 /* This function checks that every (envelope) recipient is mentioned in either
2255 the To: or Cc: header lines, thus detecting blind carbon copies.
2257 There are two ways of scanning that could be used: either scan the header lines
2258 and tick off the recipients, or scan the recipients and check the header lines.
2259 The original proposed patch did the former, but I have chosen to do the latter,
2260 because (a) it requires no memory and (b) will use fewer resources when there
2261 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2264 Returns: OK if there are no blind recipients
2265 FAIL if there is at least one blind recipient
2269 verify_check_notblind(void)
2272 for (i = 0; i < recipients_count; i++)
2276 uschar *address = recipients_list[i].address;
2278 for (h = header_list; !found && h != NULL; h = h->next)
2282 if (h->type != htype_to && h->type != htype_cc) continue;
2284 colon = Ustrchr(h->text, ':');
2286 while (isspace(*s)) s++;
2288 /* Loop for multiple addresses in the header, enabling group syntax. Note
2289 that we have to reset this after the header has been scanned. */
2291 parse_allow_group = TRUE;
2295 uschar *ss = parse_find_address_end(s, FALSE);
2296 uschar *recipient,*errmess;
2297 int terminator = *ss;
2298 int start, end, domain;
2300 /* Temporarily terminate the string at this point, and extract the
2301 operative address within, allowing group syntax. */
2304 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2307 /* If we found a valid recipient that has a domain, compare it with the
2308 envelope recipient. Local parts are compared case-sensitively, domains
2309 case-insensitively. By comparing from the start with length "domain", we
2310 include the "@" at the end, which ensures that we are comparing the whole
2311 local part of each address. */
2313 if (recipient != NULL && domain != 0)
2315 found = Ustrncmp(recipient, address, domain) == 0 &&
2316 strcmpic(recipient + domain, address + domain) == 0;
2320 /* Advance to the next address */
2322 s = ss + (terminator? 1:0);
2323 while (isspace(*s)) s++;
2324 } /* Next address */
2326 parse_allow_group = FALSE;
2327 parse_found_group = FALSE;
2328 } /* Next header (if found is false) */
2330 if (!found) return FAIL;
2331 } /* Next recipient */
2338 /*************************************************
2339 * Find if verified sender *
2340 *************************************************/
2342 /* Usually, just a single address is verified as the sender of the message.
2343 However, Exim can be made to verify other addresses as well (often related in
2344 some way), and this is useful in some environments. There may therefore be a
2345 chain of such addresses that have previously been tested. This function finds
2346 whether a given address is on the chain.
2348 Arguments: the address to be verified
2349 Returns: pointer to an address item, or NULL
2353 verify_checked_sender(uschar *sender)
2356 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2357 if (Ustrcmp(sender, addr->address) == 0) break;
2365 /*************************************************
2366 * Get valid header address *
2367 *************************************************/
2369 /* Scan the originator headers of the message, looking for an address that
2370 verifies successfully. RFC 822 says:
2372 o The "Sender" field mailbox should be sent notices of
2373 any problems in transport or delivery of the original
2374 messages. If there is no "Sender" field, then the
2375 "From" field mailbox should be used.
2377 o If the "Reply-To" field exists, then the reply should
2378 go to the addresses indicated in that field and not to
2379 the address(es) indicated in the "From" field.
2381 So we check a Sender field if there is one, else a Reply_to field, else a From
2382 field. As some strange messages may have more than one of these fields,
2383 especially if they are resent- fields, check all of them if there is more than
2387 user_msgptr points to where to put a user error message
2388 log_msgptr points to where to put a log error message
2389 callout timeout for callout check (passed to verify_address())
2390 callout_overall overall callout timeout (ditto)
2391 callout_connect connect callout timeout (ditto)
2392 se_mailfrom mailfrom for verify; NULL => ""
2393 pm_mailfrom sender for pm callout check (passed to verify_address())
2394 options callout options (passed to verify_address())
2395 verrno where to put the address basic_errno
2397 If log_msgptr is set to something without setting user_msgptr, the caller
2398 normally uses log_msgptr for both things.
2400 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2401 FAIL is given if no appropriate headers are found
2405 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2406 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2407 uschar *pm_mailfrom, int options, int *verrno)
2409 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2414 for (i = 0; i < 3 && !done; i++)
2417 for (h = header_list; h != NULL && !done; h = h->next)
2419 int terminator, new_ok;
2420 uschar *s, *ss, *endname;
2422 if (h->type != header_types[i]) continue;
2423 s = endname = Ustrchr(h->text, ':') + 1;
2425 /* Scan the addresses in the header, enabling group syntax. Note that we
2426 have to reset this after the header has been scanned. */
2428 parse_allow_group = TRUE;
2432 address_item *vaddr;
2434 while (isspace(*s) || *s == ',') s++;
2435 if (*s == 0) break; /* End of header */
2437 ss = parse_find_address_end(s, FALSE);
2439 /* The terminator is a comma or end of header, but there may be white
2440 space preceding it (including newline for the last address). Move back
2441 past any white space so we can check against any cached envelope sender
2442 address verifications. */
2444 while (isspace(ss[-1])) ss--;
2448 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2449 (int)(endname - h->text), h->text, s);
2451 /* See if we have already verified this address as an envelope sender,
2452 and if so, use the previous answer. */
2454 vaddr = verify_checked_sender(s);
2456 if (vaddr != NULL && /* Previously checked */
2457 (callout <= 0 || /* No callout needed; OR */
2458 vaddr->special_action > 256)) /* Callout was done */
2460 new_ok = vaddr->special_action & 255;
2461 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2462 *ss = terminator; /* Restore shortened string */
2465 /* Otherwise we run the verification now. We must restore the shortened
2466 string before running the verification, so the headers are correct, in
2467 case there is any rewriting. */
2471 int start, end, domain;
2472 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2477 /* If we found an empty address, just carry on with the next one, but
2478 kill the message. */
2480 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2487 /* If verification failed because of a syntax error, fail this
2488 function, and ensure that the failing address gets added to the error
2491 if (address == NULL)
2494 while (ss > s && isspace(ss[-1])) ss--;
2495 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2496 "scanning for sender: %s in \"%.*s\"",
2497 endname - h->text, h->text, *log_msgptr, ss - s, s);
2503 /* Else go ahead with the sender verification. But it isn't *the*
2504 sender of the message, so set vopt_fake_sender to stop sender_address
2505 being replaced after rewriting or qualification. */
2509 vaddr = deliver_make_addr(address, FALSE);
2510 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2511 callout, callout_overall, callout_connect, se_mailfrom,
2516 /* We now have the result, either newly found, or cached. If we are
2517 giving out error details, set a specific user error. This means that the
2518 last of these will be returned to the user if all three fail. We do not
2519 set a log message - the generic one below will be used. */
2523 *verrno = vaddr->basic_errno;
2524 if (smtp_return_error_details)
2526 *user_msgptr = string_sprintf("Rejected after DATA: "
2527 "could not verify \"%.*s\" header address\n%s: %s",
2528 endname - h->text, h->text, vaddr->address, vaddr->message);
2532 /* Success or defer */
2541 if (new_ok == DEFER) yield = DEFER;
2543 /* Move on to any more addresses in the header */
2546 } /* Next address */
2548 parse_allow_group = FALSE;
2549 parse_found_group = FALSE;
2550 } /* Next header, unless done */
2551 } /* Next header type unless done */
2553 if (yield == FAIL && *log_msgptr == NULL)
2554 *log_msgptr = US"there is no valid sender in any header line";
2556 if (yield == DEFER && *log_msgptr == NULL)
2557 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2565 /*************************************************
2566 * Get RFC 1413 identification *
2567 *************************************************/
2569 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2570 the timeout is set to zero, then the query is not done. There may also be lists
2571 of hosts and nets which are exempt. To guard against malefactors sending
2572 non-printing characters which could, for example, disrupt a message's headers,
2573 make sure the string consists of printing characters only.
2576 port the port to connect to; usually this is IDENT_PORT (113), but when
2577 running in the test harness with -bh a different value is used.
2581 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2585 verify_get_ident(int port)
2587 int sock, host_af, qlen;
2588 int received_sender_port, received_interface_port, n;
2590 uschar buffer[2048];
2592 /* Default is no ident. Check whether we want to do an ident check for this
2595 sender_ident = NULL;
2596 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2599 DEBUG(D_ident) debug_printf("doing ident callback\n");
2601 /* Set up a connection to the ident port of the remote host. Bind the local end
2602 to the incoming interface address. If the sender host address is an IPv6
2603 address, the incoming interface address will also be IPv6. */
2605 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2606 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2608 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2610 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2615 if (ip_connect(sock, host_af, sender_host_address, port,
2616 rfc1413_query_timeout, TRUE) < 0)
2618 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2619 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2620 sender_host_address);
2622 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2623 sender_host_address, strerror(errno));
2627 /* Construct and send the query. */
2629 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2630 qlen = Ustrlen(buffer);
2631 if (send(sock, buffer, qlen, 0) < 0)
2633 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2637 /* Read a response line. We put it into the rest of the buffer, using several
2638 recv() calls if necessary. */
2646 int size = sizeof(buffer) - (p - buffer);
2648 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2649 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2650 if (count <= 0) goto END_OFF; /* Read error or EOF */
2652 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2653 generous, and accept a plain \n terminator as well. The only illegal
2656 for (pp = p; pp < p + count; pp++)
2658 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2661 if (pp[-1] == '\r') pp--;
2663 goto GOT_DATA; /* Break out of both loops */
2667 /* Reached the end of the data without finding \n. Let the loop continue to
2668 read some more, if there is room. */
2675 /* We have received a line of data. Check it carefully. It must start with the
2676 same two port numbers that we sent, followed by data as defined by the RFC. For
2679 12345 , 25 : USERID : UNIX :root
2681 However, the amount of white space may be different to what we sent. In the
2682 "osname" field there may be several sub-fields, comma separated. The data we
2683 actually want to save follows the third colon. Some systems put leading spaces
2684 in it - we discard those. */
2686 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2687 &received_interface_port, &n) != 2 ||
2688 received_sender_port != sender_host_port ||
2689 received_interface_port != interface_port)
2692 p = buffer + qlen + n;
2693 while(isspace(*p)) p++;
2694 if (*p++ != ':') goto END_OFF;
2695 while(isspace(*p)) p++;
2696 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2698 while(isspace(*p)) p++;
2699 if (*p++ != ':') goto END_OFF;
2700 while (*p != 0 && *p != ':') p++;
2701 if (*p++ == 0) goto END_OFF;
2702 while(isspace(*p)) p++;
2703 if (*p == 0) goto END_OFF;
2705 /* The rest of the line is the data we want. We turn it into printing
2706 characters when we save it, so that it cannot mess up the format of any logging
2707 or Received: lines into which it gets inserted. We keep a maximum of 127
2708 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2710 sender_ident = US string_printing(string_copyn(p, 127));
2711 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2721 /*************************************************
2722 * Match host to a single host-list item *
2723 *************************************************/
2725 /* This function compares a host (name or address) against a single item
2726 from a host list. The host name gets looked up if it is needed and is not
2727 already known. The function is called from verify_check_this_host() via
2728 match_check_list(), which is why most of its arguments are in a single block.
2731 arg the argument block (see below)
2732 ss the host-list item
2733 valueptr where to pass back looked up data, or NULL
2734 error for error message when returning ERROR
2737 host_name (a) the host name, or
2738 (b) NULL, implying use sender_host_name and
2739 sender_host_aliases, looking them up if required, or
2740 (c) the empty string, meaning that only IP address matches
2742 host_address the host address
2743 host_ipv4 the IPv4 address taken from an IPv6 one
2747 DEFER lookup deferred
2748 ERROR (a) failed to find the host name or IP address, or
2749 (b) unknown lookup type specified, or
2750 (c) host name encountered when only IP addresses are
2755 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2757 check_host_block *cb = (check_host_block *)arg;
2760 BOOL iplookup = FALSE;
2761 BOOL isquery = FALSE;
2762 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2767 /* Optimize for the special case when the pattern is "*". */
2769 if (*ss == '*' && ss[1] == 0) return OK;
2771 /* If the pattern is empty, it matches only in the case when there is no host -
2772 this can occur in ACL checking for SMTP input using the -bs option. In this
2773 situation, the host address is the empty string. */
2775 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2776 if (*ss == 0) return FAIL;
2778 /* If the pattern is precisely "@" then match against the primary host name,
2779 provided that host name matching is permitted; if it's "@[]" match against the
2780 local host's IP addresses. */
2786 if (isiponly) return ERROR;
2787 ss = primary_hostname;
2789 else if (Ustrcmp(ss, "@[]") == 0)
2791 ip_address_item *ip;
2792 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2793 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2798 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2799 a (possibly masked) comparison with the current IP address. */
2801 if (string_is_ip_address(ss, &maskoffset) != 0)
2802 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2804 /* The pattern is not an IP address. A common error that people make is to omit
2805 one component of an IPv4 address, either by accident, or believing that, for
2806 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,
2807 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2808 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2809 ancient specification.) To aid in debugging these cases, we give a specific
2810 error if the pattern contains only digits and dots or contains a slash preceded
2811 only by digits and dots (a slash at the start indicates a file name and of
2812 course slashes may be present in lookups, but not preceded only by digits and
2815 for (t = ss; isdigit(*t) || *t == '.'; t++);
2816 if (*t == 0 || (*t == '/' && t != ss))
2818 *error = US"malformed IPv4 address or address mask";
2822 /* See if there is a semicolon in the pattern */
2824 semicolon = Ustrchr(ss, ';');
2826 /* If we are doing an IP address only match, then all lookups must be IP
2827 address lookups, even if there is no "net-". */
2831 iplookup = semicolon != NULL;
2834 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2835 a lookup on a masked IP network, in textual form. We obey this code even if we
2836 have already set iplookup, so as to skip over the "net-" prefix and to set the
2837 mask length. The net- stuff really only applies to single-key lookups where the
2838 key is implicit. For query-style lookups the key is specified in the query.
2839 From release 4.30, the use of net- for query style is no longer needed, but we
2840 retain it for backward compatibility. */
2842 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2845 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2846 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2847 iplookup = (*t++ == '-');
2851 /* Do the IP address lookup if that is indeed what we have */
2859 uschar *filename, *key, *result;
2862 /* Find the search type */
2864 search_type = search_findtype(t, semicolon - t);
2866 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2867 search_error_message);
2869 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2870 is no file name, and the "key" is just the query. For query-style with a file
2871 name, we have to fish the file off the start of the query. For a single-key
2872 lookup, the key is the current IP address, masked appropriately, and
2873 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2874 dot separators instead of colons, except when the lookup type is "iplsearch".
2877 if (mac_islookup(search_type, lookup_absfilequery))
2879 filename = semicolon + 1;
2881 while (*key != 0 && !isspace(*key)) key++;
2882 filename = string_copyn(filename, key - filename);
2883 while (isspace(*key)) key++;
2885 else if (mac_islookup(search_type, lookup_querystyle))
2888 key = semicolon + 1;
2890 else /* Single-key style */
2892 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2894 insize = host_aton(cb->host_address, incoming);
2895 host_mask(insize, incoming, mlen);
2896 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2898 filename = semicolon + 1;
2901 /* Now do the actual lookup; note that there is no search_close() because
2902 of the caching arrangements. */
2904 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2905 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2907 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2908 if (valueptr != NULL) *valueptr = result;
2909 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2912 /* The pattern is not an IP address or network reference of any kind. That is,
2913 it is a host name pattern. If this is an IP only match, there's an error in the
2918 *error = US"cannot match host name in match_ip list";
2922 /* Check the characters of the pattern to see if they comprise only letters,
2923 digits, full stops, and hyphens (the constituents of domain names). Allow
2924 underscores, as they are all too commonly found. Sigh. Also, if
2925 allow_utf8_domains is set, allow top-bit characters. */
2927 for (t = ss; *t != 0; t++)
2928 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2929 (!allow_utf8_domains || *t < 128)) break;
2931 /* If the pattern is a complete domain name, with no fancy characters, look up
2932 its IP address and match against that. Note that a multi-homed host will add
2933 items to the chain. */
2944 /* Using byname rather than bydns here means we cannot determine dnssec
2945 status. On the other hand it is unclear how that could be either
2946 propagated up or enforced. */
2948 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2949 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2952 for (hh = &h; hh != NULL; hh = hh->next)
2954 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2958 if (rc == HOST_FIND_AGAIN) return DEFER;
2959 *error = string_sprintf("failed to find IP address for %s", ss);
2963 /* Almost all subsequent comparisons require the host name, and can be done
2964 using the general string matching function. When this function is called for
2965 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2966 must use sender_host_name and its aliases, looking them up if necessary. */
2968 if (cb->host_name != NULL) /* Explicit host name given */
2969 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2972 /* Host name not given; in principle we need the sender host name and its
2973 aliases. However, for query-style lookups, we do not need the name if the
2974 query does not contain $sender_host_name. From release 4.23, a reference to
2975 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2978 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2980 const uschar *affix;
2981 int partial, affixlen, starflags, id;
2984 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2987 if (id < 0) /* Unknown lookup type */
2989 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2990 search_error_message, ss);
2993 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2998 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3001 case DEFER: return DEFER;
3002 default: return FAIL;
3006 /* Not a query-style lookup; must ensure the host name is present, and then we
3007 do a check on the name and all its aliases. */
3009 if (sender_host_name == NULL)
3011 HDEBUG(D_host_lookup)
3012 debug_printf("sender host name required, to match against %s\n", ss);
3013 if (host_lookup_failed || host_name_lookup() != OK)
3015 *error = string_sprintf("failed to find host name for %s",
3016 sender_host_address);;
3019 host_build_sender_fullhost();
3022 /* Match on the sender host name, using the general matching function */
3024 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3028 case DEFER: return DEFER;
3031 /* If there are aliases, try matching on them. */
3033 aliases = sender_host_aliases;
3034 while (*aliases != NULL)
3036 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3039 case DEFER: return DEFER;
3048 /*************************************************
3049 * Check a specific host matches a host list *
3050 *************************************************/
3052 /* This function is passed a host list containing items in a number of
3053 different formats and the identity of a host. Its job is to determine whether
3054 the given host is in the set of hosts defined by the list. The host name is
3055 passed as a pointer so that it can be looked up if needed and not already
3056 known. This is commonly the case when called from verify_check_host() to check
3057 an incoming connection. When called from elsewhere the host name should usually
3060 This function is now just a front end to match_check_list(), which runs common
3061 code for scanning a list. We pass it the check_host() function to perform a
3065 listptr pointer to the host list
3066 cache_bits pointer to cache for named lists, or NULL
3067 host_name the host name or NULL, implying use sender_host_name and
3068 sender_host_aliases, looking them up if required
3069 host_address the IP address
3070 valueptr if not NULL, data from a lookup is passed back here
3072 Returns: OK if the host is in the defined set
3073 FAIL if the host is not in the defined set,
3074 DEFER if a data lookup deferred (not a host lookup)
3076 If the host name was needed in order to make a comparison, and could not be
3077 determined from the IP address, the result is FAIL unless the item
3078 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3081 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3082 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3085 unsigned int *local_cache_bits = cache_bits;
3086 const uschar *save_host_address = deliver_host_address;
3087 check_host_block cb;
3088 cb.host_name = host_name;
3089 cb.host_address = host_address;
3091 if (valueptr != NULL) *valueptr = NULL;
3093 /* If the host address starts off ::ffff: it is an IPv6 address in
3094 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3097 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3098 host_address + 7 : host_address;
3100 /* During the running of the check, put the IP address into $host_address. In
3101 the case of calls from the smtp transport, it will already be there. However,
3102 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3103 the safe side, any existing setting is preserved, though as I write this
3104 (November 2004) I can't see any cases where it is actually needed. */
3106 deliver_host_address = host_address;
3107 rc = match_check_list(
3108 listptr, /* the list */
3109 0, /* separator character */
3110 &hostlist_anchor, /* anchor pointer */
3111 &local_cache_bits, /* cache pointer */
3112 check_host, /* function for testing */
3113 &cb, /* argument for function */
3114 MCL_HOST, /* type of check */
3115 (host_address == sender_host_address)?
3116 US"host" : host_address, /* text for debugging */
3117 valueptr); /* where to pass back data */
3118 deliver_host_address = save_host_address;
3125 /*************************************************
3126 * Check the given host item matches a list *
3127 *************************************************/
3129 verify_check_given_host(uschar **listptr, host_item *host)
3131 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3134 /*************************************************
3135 * Check the remote host matches a list *
3136 *************************************************/
3138 /* This is a front end to verify_check_this_host(), created because checking
3139 the remote host is a common occurrence. With luck, a good compiler will spot
3140 the tail recursion and optimize it. If there's no host address, this is
3141 command-line SMTP input - check against an empty string for the address.
3144 listptr pointer to the host list
3146 Returns: the yield of verify_check_this_host(),
3147 i.e. OK, FAIL, or DEFER
3151 verify_check_host(uschar **listptr)
3153 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3154 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3161 /*************************************************
3162 * Invert an IP address *
3163 *************************************************/
3165 /* Originally just used for DNS xBL lists, now also used for the
3166 reverse_ip expansion operator.
3169 buffer where to put the answer
3170 address the address to invert
3174 invert_address(uschar *buffer, uschar *address)
3177 uschar *bptr = buffer;
3179 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3180 to the IPv4 part only. */
3182 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3184 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3187 if (host_aton(address, bin) == 1)
3191 for (i = 0; i < 4; i++)
3193 sprintf(CS bptr, "%d.", x & 255);
3194 while (*bptr) bptr++;
3199 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3200 in any DNS black lists, and the format in which they will be looked up is
3201 unknown. This is just a guess. */
3207 for (j = 3; j >= 0; j--)
3210 for (i = 0; i < 8; i++)
3212 sprintf(CS bptr, "%x.", x & 15);
3213 while (*bptr) bptr++;
3220 /* Remove trailing period -- this is needed so that both arbitrary
3221 dnsbl keydomains and inverted addresses may be combined with the
3222 same format string, "%s.%s" */
3229 /*************************************************
3230 * Perform a single dnsbl lookup *
3231 *************************************************/
3233 /* This function is called from verify_check_dnsbl() below. It is also called
3234 recursively from within itself when domain and domain_txt are different
3235 pointers, in order to get the TXT record from the alternate domain.
3238 domain the outer dnsbl domain
3239 domain_txt alternate domain to lookup TXT record on success; when the
3240 same domain is to be used, domain_txt == domain (that is,
3241 the pointers must be identical, not just the text)
3242 keydomain the current keydomain (for debug message)
3243 prepend subdomain to lookup (like keydomain, but
3244 reversed if IP address)
3245 iplist the list of matching IP addresses, or NULL for "any"
3246 bitmask true if bitmask matching is wanted
3247 match_type condition for 'succeed' result
3248 0 => Any RR in iplist (=)
3249 1 => No RR in iplist (!=)
3250 2 => All RRs in iplist (==)
3251 3 => Some RRs not in iplist (!==)
3252 the two bits are defined as MT_NOT and MT_ALL
3253 defer_return what to return for a defer
3255 Returns: OK if lookup succeeded
3260 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3261 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3267 dnsbl_cache_block *cb;
3268 int old_pool = store_pool;
3269 uschar query[256]; /* DNS domain max length */
3271 /* Construct the specific query domainname */
3273 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3275 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3276 "(ignored): %s...", query);
3280 /* Look for this query in the cache. */
3282 if ( (t = tree_search(dnsbl_cache, query))
3283 && (cb = t->data.ptr)->expiry > time(NULL)
3286 /* Previous lookup was cached */
3289 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3292 /* If not cached from a previous lookup, we must do a DNS lookup, and
3293 cache the result in permanent memory. */
3299 store_pool = POOL_PERM;
3303 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3307 { /* Set up a tree entry to cache the lookup */
3308 t = store_get(sizeof(tree_node) + Ustrlen(query));
3309 Ustrcpy(t->name, query);
3310 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3311 (void)tree_insertnode(&dnsbl_cache, t);
3314 /* Do the DNS lookup . */
3316 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3317 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3318 cb->text_set = FALSE;
3322 /* If the lookup succeeded, cache the RHS address. The code allows for
3323 more than one address - this was for complete generality and the possible
3324 use of A6 records. However, A6 records have been reduced to experimental
3325 status (August 2001) and may die out. So they may never get used at all,
3326 let alone in dnsbl records. However, leave the code here, just in case.
3328 Quite apart from one A6 RR generating multiple addresses, there are DNS
3329 lists that return more than one A record, so we must handle multiple
3330 addresses generated in that way as well.
3332 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3333 or some suitably far-future time if none were found. */
3335 if (cb->rc == DNS_SUCCEED)
3338 dns_address **addrp = &(cb->rhs);
3339 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3341 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3343 if (rr->type == T_A)
3345 dns_address *da = dns_address_from_rr(&dnsa, rr);
3349 while (da->next != NULL) da = da->next;
3350 addrp = &(da->next);
3351 if (ttl > rr->ttl) ttl = rr->ttl;
3356 /* If we didn't find any A records, change the return code. This can
3357 happen when there is a CNAME record but there are no A records for what
3360 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3363 cb->expiry = time(NULL)+ttl;
3364 store_pool = old_pool;
3367 /* We now have the result of the DNS lookup, either newly done, or cached
3368 from a previous call. If the lookup succeeded, check against the address
3369 list if there is one. This may be a positive equality list (introduced by
3370 "="), a negative equality list (introduced by "!="), a positive bitmask
3371 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3373 if (cb->rc == DNS_SUCCEED)
3375 dns_address *da = NULL;
3376 uschar *addlist = cb->rhs->address;
3378 /* For A and AAAA records, there may be multiple addresses from multiple
3379 records. For A6 records (currently not expected to be used) there may be
3380 multiple addresses from a single record. */
3382 for (da = cb->rhs->next; da != NULL; da = da->next)
3383 addlist = string_sprintf("%s, %s", addlist, da->address);
3385 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3388 /* Address list check; this can be either for equality, or via a bitmask.
3389 In the latter case, all the bits must match. */
3393 for (da = cb->rhs; da != NULL; da = da->next)
3397 const uschar *ptr = iplist;
3400 /* Handle exact matching */
3404 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3406 if (Ustrcmp(CS da->address, ip) == 0) break;
3410 /* Handle bitmask matching */
3417 /* At present, all known DNS blocking lists use A records, with
3418 IPv4 addresses on the RHS encoding the information they return. I
3419 wonder if this will linger on as the last vestige of IPv4 when IPv6
3420 is ubiquitous? Anyway, for now we use paranoia code to completely
3421 ignore IPv6 addresses. The default mask is 0, which always matches.
3422 We change this only for IPv4 addresses in the list. */
3424 if (host_aton(da->address, address) == 1) mask = address[0];
3426 /* Scan the returned addresses, skipping any that are IPv6 */
3428 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3430 if (host_aton(ip, address) != 1) continue;
3431 if ((address[0] & mask) == address[0]) break;
3437 (a) An IP address in an any ('=') list matched, or
3438 (b) No IP address in an all ('==') list matched
3440 then we're done searching. */
3442 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3445 /* If da == NULL, either
3447 (a) No IP address in an any ('=') list matched, or
3448 (b) An IP address in an all ('==') list didn't match
3450 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3453 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3461 res = US"was no match";
3464 res = US"was an exclude match";
3467 res = US"was an IP address that did not match";
3470 res = US"were no IP addresses that did not match";
3473 debug_printf("=> but we are not accepting this block class because\n");
3474 debug_printf("=> there %s for %s%c%s\n",
3476 ((match_type & MT_ALL) == 0)? "" : "=",
3477 bitmask? '&' : '=', iplist);
3483 /* Either there was no IP list, or the record matched, implying that the
3484 domain is on the list. We now want to find a corresponding TXT record. If an
3485 alternate domain is specified for the TXT record, call this function
3486 recursively to look that up; this has the side effect of re-checking that
3487 there is indeed an A record at the alternate domain. */
3489 if (domain_txt != domain)
3490 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3491 FALSE, match_type, defer_return);
3493 /* If there is no alternate domain, look up a TXT record in the main domain
3494 if it has not previously been cached. */
3498 cb->text_set = TRUE;
3499 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3502 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3504 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3505 if (rr->type == T_TXT) break;
3508 int len = (rr->data)[0];
3509 if (len > 511) len = 127;
3510 store_pool = POOL_PERM;
3511 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3512 store_pool = old_pool;
3517 dnslist_value = addlist;
3518 dnslist_text = cb->text;
3522 /* There was a problem with the DNS lookup */
3524 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3526 log_write(L_dnslist_defer, LOG_MAIN,
3527 "DNS list lookup defer (probably timeout) for %s: %s", query,
3528 (defer_return == OK)? US"assumed in list" :
3529 (defer_return == FAIL)? US"assumed not in list" :
3530 US"returned DEFER");
3531 return defer_return;
3534 /* No entry was found in the DNS; continue for next domain */
3538 debug_printf("DNS lookup for %s failed\n", query);
3539 debug_printf("=> that means %s is not listed at %s\n",
3549 /*************************************************
3550 * Check host against DNS black lists *
3551 *************************************************/
3553 /* This function runs checks against a list of DNS black lists, until one
3554 matches. Each item on the list can be of the form
3556 domain=ip-address/key
3558 The domain is the right-most domain that is used for the query, for example,
3559 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3560 if the DNS lookup returns a matching IP address. Several addresses may be
3561 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3563 If no key is given, what is looked up in the domain is the inverted IP address
3564 of the current client host. If a key is given, it is used to construct the
3565 domain for the lookup. For example:
3567 dsn.rfc-ignorant.org/$sender_address_domain
3569 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3570 then we check for a TXT record for an error message, and if found, save its
3571 value in $dnslist_text. We also cache everything in a tree, to optimize
3574 The TXT record is normally looked up in the same domain as the A record, but
3575 when many lists are combined in a single DNS domain, this will not be a very
3576 specific message. It is possible to specify a different domain for looking up
3577 TXT records; this is given before the main domain, comma-separated. For
3580 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3581 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3583 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3585 Note: an address for testing RBL is 192.203.178.39
3586 Note: an address for testing DUL is 192.203.178.4
3587 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3591 listptr the domain/address/data list
3592 log_msgptr log message on error
3594 Returns: OK successful lookup (i.e. the address is on the list), or
3595 lookup deferred after +include_unknown
3596 FAIL name not found, or no data found for the given type, or
3597 lookup deferred after +exclude_unknown (default)
3598 DEFER lookup failure, if +defer_unknown was set
3602 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3605 int defer_return = FAIL;
3606 const uschar *list = *listptr;
3609 uschar buffer[1024];
3610 uschar revadd[128]; /* Long enough for IPv6 address */
3612 /* Indicate that the inverted IP address is not yet set up */
3616 /* In case this is the first time the DNS resolver is being used. */
3618 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3620 /* Loop through all the domains supplied, until something matches */
3622 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3625 BOOL bitmask = FALSE;
3632 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3634 /* Deal with special values that change the behaviour on defer */
3636 if (domain[0] == '+')
3638 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3639 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3640 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3642 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3647 /* See if there's explicit data to be looked up */
3649 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3651 /* See if there's a list of addresses supplied after the domain name. This is
3652 introduced by an = or a & character; if preceded by = we require all matches
3653 and if preceded by ! we invert the result. */
3655 if (!(iplist = Ustrchr(domain, '=')))
3658 iplist = Ustrchr(domain, '&');
3661 if (iplist) /* Found either = or & */
3663 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3665 match_type |= MT_NOT;
3669 *iplist++ = 0; /* Terminate domain, move on */
3671 /* If we found = (bitmask == FALSE), check for == or =& */
3673 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3675 bitmask = *iplist++ == '&';
3676 match_type |= MT_ALL;
3681 /* If there is a comma in the domain, it indicates that a second domain for
3682 looking up TXT records is provided, before the main domain. Otherwise we must
3683 set domain_txt == domain. */
3685 domain_txt = domain;
3686 comma = Ustrchr(domain, ',');
3693 /* Check that what we have left is a sensible domain name. There is no reason
3694 why these domains should in fact use the same syntax as hosts and email
3695 domains, but in practice they seem to. However, there is little point in
3696 actually causing an error here, because that would no doubt hold up incoming
3697 mail. Instead, I'll just log it. */
3699 for (s = domain; *s != 0; s++)
3701 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3703 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3704 "strange characters - is this right?", domain);
3709 /* Check the alternate domain if present */
3711 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3713 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3715 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3716 "strange characters - is this right?", domain_txt);
3721 /* If there is no key string, construct the query by adding the domain name
3722 onto the inverted host address, and perform a single DNS lookup. */
3726 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3728 *log_msgptr = string_sprintf
3729 ("cannot test auto-keyed dnslists condition in %s ACL",
3730 acl_wherenames[where]);
3733 if (sender_host_address == NULL) return FAIL; /* can never match */
3734 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3735 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3736 iplist, bitmask, match_type, defer_return);
3739 dnslist_domain = string_copy(domain_txt);
3740 dnslist_matched = string_copy(sender_host_address);
3741 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3742 sender_host_address, dnslist_domain);
3744 if (rc != FAIL) return rc; /* OK or DEFER */
3747 /* If there is a key string, it can be a list of domains or IP addresses to
3748 be concatenated with the main domain. */
3755 uschar keybuffer[256];
3756 uschar keyrevadd[128];
3758 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3759 sizeof(keybuffer))) != NULL)
3761 uschar *prepend = keydomain;
3763 if (string_is_ip_address(keydomain, NULL) != 0)
3765 invert_address(keyrevadd, keydomain);
3766 prepend = keyrevadd;
3769 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3770 bitmask, match_type, defer_return);
3774 dnslist_domain = string_copy(domain_txt);
3775 dnslist_matched = string_copy(keydomain);
3776 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3777 keydomain, dnslist_domain);
3781 /* If the lookup deferred, remember this fact. We keep trying the rest
3782 of the list to see if we get a useful result, and if we don't, we return
3783 DEFER at the end. */
3785 if (rc == DEFER) defer = TRUE;
3786 } /* continue with next keystring domain/address */
3788 if (defer) return DEFER;
3790 } /* continue with next dnsdb outer domain */
3797 /* End of verify.c */