1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2014 */
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 {
31 /* Anchor for DNSBL cache */
33 static tree_node *dnsbl_cache = NULL;
36 /* Bits for match_type in one_check_dnsbl() */
41 static uschar cutthrough_response(char, uschar **);
44 /*************************************************
45 * Retrieve a callout cache record *
46 *************************************************/
48 /* If a record exists, check whether it has expired.
51 dbm_file an open hints file
53 type "address" or "domain"
54 positive_expire expire time for positive records
55 negative_expire expire time for negative records
57 Returns: the cache record if a non-expired one exists, else NULL
60 static dbdata_callout_cache *
61 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
62 int positive_expire, int negative_expire)
67 dbdata_callout_cache *cache_record;
69 cache_record = dbfn_read_with_length(dbm_file, key, &length);
71 if (cache_record == NULL)
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type);
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
85 if (now - cache_record->time_stamp > expire)
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type);
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
99 if (length == sizeof(dbdata_callout_cache_obs))
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type);
120 /*************************************************
121 * Do callout verification for an address *
122 *************************************************/
124 /* This function is called from verify_address() when the address has routed to
125 a host list, and a callout has been requested. Callouts are expensive; that is
126 why a cache is used to improve the efficiency.
129 addr the address that's been routed
130 host_list the list of hosts to try
131 tf the transport feedback block
133 ifstring "interface" option from transport, or NULL
134 portstring "port" option from transport, or NULL
135 protocolstring "protocol" option from transport, or NULL
136 callout the per-command callout timeout
137 callout_overall the overall callout timeout (if < 0 use 4*callout)
138 callout_connect the callout connection timeout (if < 0 use callout)
139 options the verification options - these bits are used:
140 vopt_is_recipient => this is a recipient address
141 vopt_callout_no_cache => don't use callout cache
142 vopt_callout_fullpm => if postmaster check, do full one
143 vopt_callout_random => do the "random" thing
144 vopt_callout_recipsender => use real sender for recipient
145 vopt_callout_recippmaster => use postmaster for recipient
146 se_mailfrom MAIL FROM address for sender verify; NULL => ""
147 pm_mailfrom if non-NULL, do the postmaster check with this sender
149 Returns: OK/FAIL/DEFER
153 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
154 int callout, int callout_overall, int callout_connect, int options,
155 uschar *se_mailfrom, uschar *pm_mailfrom)
157 BOOL is_recipient = (options & vopt_is_recipient) != 0;
158 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
159 BOOL callout_random = (options & vopt_callout_random) != 0;
162 int old_domain_cache_result = ccache_accept;
165 uschar *from_address;
166 uschar *random_local_part = NULL;
167 const uschar *save_deliver_domain = deliver_domain;
168 uschar **failure_ptr = is_recipient?
169 &recipient_verify_failure : &sender_verify_failure;
171 open_db *dbm_file = NULL;
172 dbdata_callout_cache new_domain_record;
173 dbdata_callout_cache_address new_address_record;
175 time_t callout_start_time;
177 new_domain_record.result = ccache_unknown;
178 new_domain_record.postmaster_result = ccache_unknown;
179 new_domain_record.random_result = ccache_unknown;
181 memset(&new_address_record, 0, sizeof(new_address_record));
183 /* For a recipient callout, the key used for the address cache record must
184 include the sender address if we are using the real sender in the callout,
185 because that may influence the result of the callout. */
187 address_key = addr->address;
192 if (options & vopt_callout_recipsender)
194 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
195 from_address = sender_address;
197 else if (options & vopt_callout_recippmaster)
199 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
200 qualify_domain_sender);
201 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
205 /* For a sender callout, we must adjust the key if the mailfrom address is not
210 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
211 if (from_address[0] != 0)
212 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
215 /* Open the callout cache database, it it exists, for reading only at this
216 stage, unless caching has been disabled. */
218 if (callout_no_cache)
220 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
222 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
224 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
227 /* If a cache database is available see if we can avoid the need to do an
228 actual callout by making use of previously-obtained data. */
230 if (dbm_file != NULL)
232 dbdata_callout_cache_address *cache_address_record;
233 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
234 addr->domain, US"domain",
235 callout_cache_domain_positive_expire,
236 callout_cache_domain_negative_expire);
238 /* If an unexpired cache record was found for this domain, see if the callout
239 process can be short-circuited. */
241 if (cache_record != NULL)
243 /* In most cases, if an early command (up to and including MAIL FROM:<>)
244 was rejected, there is no point carrying on. The callout fails. However, if
245 we are doing a recipient verification with use_sender or use_postmaster
246 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
247 will be using a non-empty sender. We have to remember this situation so as
248 not to disturb the cached domain value if this whole verification succeeds
249 (we don't want it turning into "accept"). */
251 old_domain_cache_result = cache_record->result;
253 if (cache_record->result == ccache_reject ||
254 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
256 setflag(addr, af_verify_nsfail);
258 debug_printf("callout cache: domain gave initial rejection, or "
259 "does not accept HELO or MAIL FROM:<>\n");
260 setflag(addr, af_verify_nsfail);
261 addr->user_message = US"(result of an earlier callout reused).";
263 *failure_ptr = US"mail";
267 /* If a previous check on a "random" local part was accepted, we assume
268 that the server does not do any checking on local parts. There is therefore
269 no point in doing the callout, because it will always be successful. If a
270 random check previously failed, arrange not to do it again, but preserve
271 the data in the new record. If a random check is required but hasn't been
272 done, skip the remaining cache processing. */
274 if (callout_random) switch(cache_record->random_result)
278 debug_printf("callout cache: domain accepts random addresses\n");
279 goto END_CALLOUT; /* Default yield is OK */
283 debug_printf("callout cache: domain rejects random addresses\n");
284 callout_random = FALSE;
285 new_domain_record.random_result = ccache_reject;
286 new_domain_record.random_stamp = cache_record->random_stamp;
291 debug_printf("callout cache: need to check random address handling "
292 "(not cached or cache expired)\n");
296 /* If a postmaster check is requested, but there was a previous failure,
297 there is again no point in carrying on. If a postmaster check is required,
298 but has not been done before, we are going to have to do a callout, so skip
299 remaining cache processing. */
301 if (pm_mailfrom != NULL)
303 if (cache_record->postmaster_result == ccache_reject)
305 setflag(addr, af_verify_pmfail);
307 debug_printf("callout cache: domain does not accept "
308 "RCPT TO:<postmaster@domain>\n");
310 *failure_ptr = US"postmaster";
311 setflag(addr, af_verify_pmfail);
312 addr->user_message = US"(result of earlier verification reused).";
315 if (cache_record->postmaster_result == ccache_unknown)
318 debug_printf("callout cache: need to check RCPT "
319 "TO:<postmaster@domain> (not cached or cache expired)\n");
323 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
324 postmaster check if the address itself has to be checked. Also ensure
325 that the value in the cache record is preserved (with its old timestamp).
328 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
329 "TO:<postmaster@domain>\n");
331 new_domain_record.postmaster_result = ccache_accept;
332 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
336 /* We can't give a result based on information about the domain. See if there
337 is an unexpired cache record for this specific address (combined with the
338 sender address if we are doing a recipient callout with a non-empty sender).
341 cache_address_record = (dbdata_callout_cache_address *)
342 get_callout_cache_record(dbm_file,
343 address_key, US"address",
344 callout_cache_positive_expire,
345 callout_cache_negative_expire);
347 if (cache_address_record != NULL)
349 if (cache_address_record->result == ccache_accept)
352 debug_printf("callout cache: address record is positive\n");
357 debug_printf("callout cache: address record is negative\n");
358 addr->user_message = US"Previous (cached) callout verification failure";
359 *failure_ptr = US"recipient";
365 /* Close the cache database while we actually do the callout for real. */
368 dbfn_close(dbm_file);
372 if (!addr->transport)
374 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
376 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
377 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
378 addr->transport->name, addr->transport->driver_name);
381 smtp_transport_options_block *ob =
382 (smtp_transport_options_block *)addr->transport->options_block;
384 /* The information wasn't available in the cache, so we have to do a real
385 callout and save the result in the cache for next time, unless no_cache is set,
386 or unless we have a previously cached negative random result. If we are to test
387 with a random local part, ensure that such a local part is available. If not,
388 log the fact, but carry on without randomming. */
390 if (callout_random && callout_random_local_part != NULL)
391 if (!(random_local_part = expand_string(callout_random_local_part)))
392 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
393 "callout_random_local_part: %s", expand_string_message);
395 /* Default the connect and overall callout timeouts if not set, and record the
396 time we are starting so that we can enforce it. */
398 if (callout_overall < 0) callout_overall = 4 * callout;
399 if (callout_connect < 0) callout_connect = callout;
400 callout_start_time = time(NULL);
402 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
403 output because a callout might take some time. When PIPELINING is active and
404 there are many recipients, the total time for doing lots of callouts can add up
405 and cause the client to time out. So in this case we forgo the PIPELINING
408 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
410 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
411 and we are holding a cutthrough conn open, we can just append the rcpt to
412 that conn for verification purposes (and later delivery also). Simplest
413 coding means skipping this whole loop and doing the append separately.
415 We will need to remember it has been appended so that rcpt-acl tail code
416 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
419 /* Can we re-use an open cutthrough connection? */
420 if ( cutthrough.fd >= 0
421 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
422 == vopt_callout_recipsender
423 && !random_local_part
427 if (addr->transport == cutthrough.addr.transport)
428 for (host = host_list; host; host = host->next)
429 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
432 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
435 deliver_host = host->name;
436 deliver_host_address = host->address;
437 deliver_host_port = host->port;
438 deliver_domain = addr->domain;
439 transport_name = addr->transport->name;
441 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
443 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
445 !smtp_get_port(tf->port, addr, &port, US"callout"))
446 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
449 if ( ( interface == cutthrough.interface
451 && cutthrough.interface
452 && Ustrcmp(interface, cutthrough.interface) == 0
454 && port == cutthrough.host.port
459 /* Match! Send the RCPT TO, append the addr, set done */
461 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
462 transport_rcpt_address(addr,
463 (addr->transport == NULL)? FALSE :
464 addr->transport->rcpt_include_affixes)) >= 0 &&
465 cutthrough_response('2', &resp) == '2';
467 /* This would go horribly wrong if a callout fail was ignored by ACL.
468 We punt by abandoning cutthrough on a reject, like the
473 address_item * na = store_get(sizeof(address_item));
474 *na = cutthrough.addr;
475 cutthrough.addr = *addr;
476 cutthrough.addr.host_used = &cutthrough.host;
477 cutthrough.addr.next = na;
483 cancel_cutthrough_connection("recipient rejected");
484 if (errno == ETIMEDOUT)
486 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
491 Ustrcpy(resp, US"connection dropped");
494 string_sprintf("response to \"%s\" from %s [%s] was: %s",
495 big_buffer, host->name, host->address,
496 string_printing(resp));
499 string_sprintf("Callout verification failed:\n%s", resp);
501 /* Hard rejection ends the process */
503 if (resp[0] == '5') /* Address rejected */
514 cancel_cutthrough_connection("incompatible connection");
517 /* Now make connections to the hosts and do real callouts. The list of hosts
518 is passed in as an argument. */
520 for (host = host_list; host != NULL && !done; host = host->next)
522 smtp_inblock inblock;
523 smtp_outblock outblock;
526 BOOL send_quit = TRUE;
527 uschar *active_hostname = smtp_active_hostname;
531 BOOL suppress_tls = FALSE;
532 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
533 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
536 dns_answer tlsa_dnsa;
538 uschar inbuffer[4096];
539 uschar outbuffer[1024];
540 uschar responsebuffer[4096];
542 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
543 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
545 /* Skip this host if we don't have an IP address for it. */
547 if (host->address == NULL)
549 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
554 /* Check the overall callout timeout */
556 if (time(NULL) - callout_start_time >= callout_overall)
558 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
562 /* Set IPv4 or IPv6 */
564 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
566 /* Expand and interpret the interface and port strings. The latter will not
567 be used if there is a host-specific port (e.g. from a manualroute router).
568 This has to be delayed till now, because they may expand differently for
569 different hosts. If there's a failure, log it, but carry on with the
572 deliver_host = host->name;
573 deliver_host_address = host->address;
574 deliver_host_port = host->port;
575 deliver_domain = addr->domain;
576 transport_name = addr->transport->name;
578 if ( !smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
580 || !smtp_get_port(tf->port, addr, &port, US"callout")
582 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
585 /* Set HELO string according to the protocol */
586 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
587 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
590 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
592 /* Set up the buffer for reading SMTP response packets. */
594 inblock.buffer = inbuffer;
595 inblock.buffersize = sizeof(inbuffer);
596 inblock.ptr = inbuffer;
597 inblock.ptrend = inbuffer;
599 /* Set up the buffer for holding SMTP commands while pipelining */
601 outblock.buffer = outbuffer;
602 outblock.buffersize = sizeof(outbuffer);
603 outblock.ptr = outbuffer;
604 outblock.cmd_count = 0;
605 outblock.authenticating = FALSE;
607 /* Connect to the host; on failure, just loop for the next one, but we
608 set the error for the last one. Use the callout_connect timeout. */
610 tls_retry_connection:
612 /* Reset the parameters of a TLS session */
613 tls_out.cipher = tls_out.peerdn = tls_out.peercert = NULL;
615 inblock.sock = outblock.sock =
616 smtp_connect(host, host_af, port, interface, callout_connect,
618 if (inblock.sock < 0)
620 addr->message = string_sprintf("could not connect to %s [%s]: %s",
621 host->name, host->address, strerror(errno));
622 transport_name = NULL;
623 deliver_host = deliver_host_address = NULL;
624 deliver_domain = save_deliver_domain;
628 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
632 tls_out.dane_verified = FALSE;
633 tls_out.tlsa_usage = 0;
636 verify_check_given_host(&ob->hosts_require_dane, host) == OK;
638 if (host->dnssec == DS_YES)
641 || verify_check_given_host(&ob->hosts_try_dane, host) == OK
643 && (rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK
647 else if (dane_required)
649 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
654 ob->tls_tempfail_tryclear = FALSE;
658 /* Expand the helo_data string to find the host name to use. */
660 if (tf->helo_data != NULL)
662 uschar *s = expand_string(tf->helo_data);
664 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
665 "helo_data value for callout: %s", addr->address,
666 expand_string_message);
667 else active_hostname = s;
670 /* Wait for initial response, and send HELO. The smtp_write_command()
671 function leaves its command in big_buffer. This is used in error responses.
672 Initialize it in case the connection is rejected. */
674 Ustrcpy(big_buffer, "initial connection");
676 /* Unless ssl-on-connect, wait for the initial greeting */
680 if (!smtps || (smtps && tls_out.active >= 0))
683 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
684 goto RESPONSE_FAILED;
686 #ifdef EXPERIMENTAL_EVENT
687 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
688 : host->dnssec==DS_NO ? US"no" : NULL;
689 if (event_raise(addr->transport->event_action,
690 US"smtp:connect", responsebuffer))
692 lookup_dnssec_authenticated = NULL;
693 /* Logging? Debug? */
694 goto RESPONSE_FAILED;
696 lookup_dnssec_authenticated = NULL;
700 /* Not worth checking greeting line for ESMTP support */
701 if (!(esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK))
703 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
708 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
711 ob->tls_tempfail_tryclear = FALSE;
713 else /* all other cases */
718 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
719 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
721 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
723 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
726 goto RESPONSE_FAILED;
732 goto esmtp_retry; /* fallback to HELO */
735 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
737 if (esmtp && !suppress_tls && tls_out.active < 0)
739 if (regex_STARTTLS == NULL) regex_STARTTLS =
740 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
742 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
743 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
750 /* If TLS is available on this connection attempt to
751 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
752 send another EHLO - the server may give a different answer in secure mode. We
753 use a separate buffer for reading the response to STARTTLS so that if it is
754 negative, the original EHLO data is available for subsequent analysis, should
755 the client not be required to use TLS. If the response is bad, copy the buffer
756 for error analysis. */
760 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK
761 && verify_check_given_host(&ob->hosts_verify_avoid_tls, host) != OK
764 uschar buffer2[4096];
766 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
769 /* If there is an I/O error, transmission of this message is deferred. If
770 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
771 false, we also defer. However, if there is a temporary rejection of STARTTLS
772 and tls_tempfail_tryclear is true, or if there is an outright rejection of
773 STARTTLS, we carry on. This means we will try to send the message in clear,
774 unless the host is in hosts_require_tls (tested below). */
776 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
777 ob->command_timeout))
779 if (errno != 0 || buffer2[0] == 0 ||
780 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
782 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
784 goto RESPONSE_FAILED;
788 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
791 int oldtimeout = ob->command_timeout;
795 ob->command_timeout = callout;
796 rc = tls_client_start(inblock.sock, host, addr, addr->transport
797 # ifdef EXPERIMENTAL_DANE
798 , dane ? &tlsa_dnsa : NULL
801 ob->command_timeout = oldtimeout;
803 /* TLS negotiation failed; give an error. Try in clear on a new
804 connection, if the options permit it for this host. */
809 (void)close(inblock.sock);
810 # ifdef EXPERIMENTAL_EVENT
811 (void) event_raise(addr->transport->event_action,
812 US"tcp:close", NULL);
814 # ifdef EXPERIMENTAL_DANE
819 log_write(0, LOG_MAIN, "DANE attempt failed;"
820 " trying CA-root TLS to %s [%s] (not in hosts_require_dane)",
821 host->name, host->address);
828 if ( ob->tls_tempfail_tryclear
830 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
833 log_write(0, LOG_MAIN, "TLS session failure:"
834 " delivering unencrypted to %s [%s] (not in hosts_require_tls)",
835 host->name, host->address);
837 goto tls_retry_connection;
841 /*save_errno = ERRNO_TLSFAILURE;*/
842 /*message = US"failure while setting up TLS session";*/
848 /* TLS session is set up. Copy info for logging. */
849 addr->cipher = tls_out.cipher;
850 addr->peerdn = tls_out.peerdn;
852 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
854 goto smtps_redo_greeting;
856 /* For STARTTLS we need to redo EHLO */
861 /* If the host is required to use a secure channel, ensure that we have one. */
862 if (tls_out.active < 0)
864 # ifdef EXPERIMENTAL_DANE
867 verify_check_given_host(&ob->hosts_require_tls, host) == OK
870 /*save_errno = ERRNO_TLSREQUIRED;*/
871 log_write(0, LOG_MAIN,
872 "H=%s [%s]: a TLS session is required for this host, but %s",
873 host->name, host->address,
874 tls_offered ? "an attempt to start TLS failed"
875 : "the server did not offer TLS support");
880 #endif /*SUPPORT_TLS*/
882 done = TRUE; /* so far so good; have response to HELO */
884 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
886 /* For now, transport_filter by cutthrough-delivery is not supported */
887 /* Need proper integration with the proper transport mechanism. */
888 if (cutthrough.delivery)
890 if (addr->transport->filter_command)
892 cutthrough.delivery = FALSE;
893 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
898 cutthrough.delivery = FALSE;
899 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
908 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
910 /* Failure to accept HELO is cached; this blocks the whole domain for all
911 senders. I/O errors and defer responses are not cached. */
915 *failure_ptr = US"mail"; /* At or before MAIL */
916 if (errno == 0 && responsebuffer[0] == '5')
918 setflag(addr, af_verify_nsfail);
919 new_domain_record.result = ccache_reject;
923 #ifdef EXPERIMENTAL_INTERNATIONAL
924 else if ( addr->p.utf8
927 || ( (regex_UTF8 = regex_must_compile(
928 US"\\n250[\\s\\-]SMTPUTF8(\\s|\\n|$)", FALSE, TRUE)),
931 && pcre_exec(regex_UTF8, NULL, CS responsebuffer,
932 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0
935 HDEBUG(D_acl|D_v) debug_printf("utf8 required but not offered\n");
936 errno = ERRNO_UTF8_FWD;
937 setflag(addr, af_verify_nsfail);
942 /* If we haven't authenticated, but are required to, give up. */
945 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
946 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
948 /* Copy AUTH info for logging */
949 ( (addr->authenticator = client_authenticator),
950 (addr->auth_id = client_authenticated_id),
952 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
953 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
956 ( (addr->auth_sndr = client_authenticated_sender),
958 /* Send the MAIL command */
959 (smtp_write_command(&outblock, FALSE,
960 #ifdef EXPERIMENTAL_INTERNATIONAL
962 ? "MAIL FROM:<%s>%s SMTPUTF8\r\n"
965 "MAIL FROM:<%s>%s\r\n",
966 from_address, responsebuffer) >= 0)
969 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
972 deliver_host = deliver_host_address = NULL;
973 deliver_domain = save_deliver_domain;
975 /* If the host does not accept MAIL FROM:<>, arrange to cache this
976 information, but again, don't record anything for an I/O error or a defer. Do
977 not cache rejections of MAIL when a non-empty sender has been used, because
978 that blocks the whole domain for all senders. */
982 *failure_ptr = US"mail"; /* At or before MAIL */
983 if (errno == 0 && responsebuffer[0] == '5')
985 setflag(addr, af_verify_nsfail);
986 if (from_address[0] == 0)
987 new_domain_record.result = ccache_reject_mfnull;
991 /* Otherwise, proceed to check a "random" address (if required), then the
992 given address, and the postmaster address (if required). Between each check,
993 issue RSET, because some servers accept only one recipient after MAIL
996 Before doing this, set the result in the domain cache record to "accept",
997 unless its previous value was ccache_reject_mfnull. In that case, the domain
998 rejects MAIL FROM:<> and we want to continue to remember that. When that is
999 the case, we have got here only in the case of a recipient verification with
1000 a non-null sender. */
1004 new_domain_record.result =
1005 (old_domain_cache_result == ccache_reject_mfnull)?
1006 ccache_reject_mfnull: ccache_accept;
1008 /* Do the random local part check first */
1010 if (random_local_part != NULL)
1012 uschar randombuffer[1024];
1014 smtp_write_command(&outblock, FALSE,
1015 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
1016 addr->domain) >= 0 &&
1017 smtp_read_response(&inblock, randombuffer,
1018 sizeof(randombuffer), '2', callout);
1020 /* Remember when we last did a random test */
1022 new_domain_record.random_stamp = time(NULL);
1024 /* If accepted, we aren't going to do any further tests below. */
1027 new_domain_record.random_result = ccache_accept;
1029 /* Otherwise, cache a real negative response, and get back to the right
1030 state to send RCPT. Unless there's some problem such as a dropped
1031 connection, we expect to succeed, because the commands succeeded above.
1032 However, some servers drop the connection after responding to an
1033 invalid recipient, so on (any) error we drop and remake the connection.
1036 else if (errno == 0)
1038 /* This would be ok for 1st rcpt a cutthrough, but no way to
1039 handle a subsequent. So refuse to support any */
1040 cancel_cutthrough_connection("random-recipient");
1042 if (randombuffer[0] == '5')
1043 new_domain_record.random_result = ccache_reject;
1046 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1047 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1050 smtp_write_command(&outblock, FALSE,
1051 #ifdef EXPERIMENTAL_INTERNATIONAL
1053 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
1056 "MAIL FROM:<%s>\r\n",
1057 from_address) >= 0 &&
1058 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1064 debug_printf("problem after random/rset/mfrom; reopen conn\n");
1065 random_local_part = NULL;
1067 tls_close(FALSE, TRUE);
1069 (void)close(inblock.sock);
1070 #ifdef EXPERIMENTAL_EVENT
1071 (void) event_raise(addr->transport->event_action,
1072 US"tcp:close", NULL);
1074 goto tls_retry_connection;
1077 else done = FALSE; /* Some timeout/connection problem */
1078 } /* Random check */
1080 /* If the host is accepting all local parts, as determined by the "random"
1081 check, we don't need to waste time doing any further checking. */
1083 if (new_domain_record.random_result != ccache_accept && done)
1085 /* Get the rcpt_include_affixes flag from the transport if there is one,
1086 but assume FALSE if there is not. */
1089 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
1090 transport_rcpt_address(addr,
1091 (addr->transport == NULL)? FALSE :
1092 addr->transport->rcpt_include_affixes)) >= 0 &&
1093 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1097 new_address_record.result = ccache_accept;
1098 else if (errno == 0 && responsebuffer[0] == '5')
1100 *failure_ptr = US"recipient";
1101 new_address_record.result = ccache_reject;
1104 /* Do postmaster check if requested; if a full check is required, we
1105 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
1107 if (done && pm_mailfrom != NULL)
1109 /* Could possibly shift before main verify, just above, and be ok
1110 for cutthrough. But no way to handle a subsequent rcpt, so just
1112 cancel_cutthrough_connection("postmaster verify");
1113 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
1116 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1117 smtp_read_response(&inblock, responsebuffer,
1118 sizeof(responsebuffer), '2', callout) &&
1120 smtp_write_command(&outblock, FALSE,
1121 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
1122 smtp_read_response(&inblock, responsebuffer,
1123 sizeof(responsebuffer), '2', callout) &&
1125 /* First try using the current domain */
1128 smtp_write_command(&outblock, FALSE,
1129 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
1130 smtp_read_response(&inblock, responsebuffer,
1131 sizeof(responsebuffer), '2', callout)
1136 /* If that doesn't work, and a full check is requested,
1137 try without the domain. */
1140 (options & vopt_callout_fullpm) != 0 &&
1141 smtp_write_command(&outblock, FALSE,
1142 "RCPT TO:<postmaster>\r\n") >= 0 &&
1143 smtp_read_response(&inblock, responsebuffer,
1144 sizeof(responsebuffer), '2', callout)
1147 /* Sort out the cache record */
1149 new_domain_record.postmaster_stamp = time(NULL);
1152 new_domain_record.postmaster_result = ccache_accept;
1153 else if (errno == 0 && responsebuffer[0] == '5')
1155 *failure_ptr = US"postmaster";
1156 setflag(addr, af_verify_pmfail);
1157 new_domain_record.postmaster_result = ccache_reject;
1160 } /* Random not accepted */
1161 } /* MAIL FROM: accepted */
1163 /* For any failure of the main check, other than a negative response, we just
1164 close the connection and carry on. We can identify a negative response by the
1165 fact that errno is zero. For I/O errors it will be non-zero
1167 Set up different error texts for logging and for sending back to the caller
1168 as an SMTP response. Log in all cases, using a one-line format. For sender
1169 callouts, give a full response to the caller, but for recipient callouts,
1170 don't give the IP address because this may be an internal host whose identity
1171 is not to be widely broadcast. */
1175 if (errno == ETIMEDOUT)
1177 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1180 #ifdef EXPERIMENTAL_INTERNATIONAL
1181 else if (errno == ERRNO_UTF8_FWD)
1183 extern int acl_where; /* src/acl.c */
1185 addr->message = string_sprintf(
1186 "response to \"%s\" from %s [%s] did not include SMTPUTF8",
1187 big_buffer, host->name, host->address);
1188 addr->user_message = acl_where == ACL_WHERE_RCPT
1189 ? US"533 mailbox name not allowed"
1190 : US"550 mailbox unavailable";
1195 else if (errno == 0)
1197 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1200 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1201 big_buffer, host->name, host->address,
1202 string_printing(responsebuffer));
1204 addr->user_message = is_recipient?
1205 string_sprintf("Callout verification failed:\n%s", responsebuffer)
1207 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1208 host->address, big_buffer, responsebuffer);
1210 /* Hard rejection ends the process */
1212 if (responsebuffer[0] == '5') /* Address rejected */
1220 /* End the SMTP conversation and close the connection. */
1222 /* Cutthrough - on a successfull connect and recipient-verify with
1223 use-sender and we are 1st rcpt and have no cutthrough conn so far
1224 here is where we want to leave the conn open */
1225 if ( cutthrough.delivery
1229 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
1230 && !random_local_part
1232 && cutthrough.fd < 0
1236 cutthrough.fd = outblock.sock; /* We assume no buffer in use in the outblock */
1237 cutthrough.nrcpt = 1;
1238 cutthrough.interface = interface;
1239 cutthrough.host = *host;
1240 cutthrough.addr = *addr; /* Save the address_item for later logging */
1241 cutthrough.addr.next = NULL;
1242 cutthrough.addr.host_used = &cutthrough.host;
1244 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1246 ctblock.buffer = ctbuffer;
1247 ctblock.buffersize = sizeof(ctbuffer);
1248 ctblock.ptr = ctbuffer;
1249 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1250 ctblock.sock = cutthrough.fd;
1254 /* Ensure no cutthrough on multiple address verifies */
1255 if (options & vopt_callout_recipsender)
1256 cancel_cutthrough_connection("multiple verify calls");
1257 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1260 tls_close(FALSE, TRUE);
1262 (void)close(inblock.sock);
1263 #ifdef EXPERIMENTAL_EVENT
1264 (void) event_raise(addr->transport->event_action,
1265 US"tcp:close", NULL);
1269 } /* Loop through all hosts, while !done */
1272 /* If we get here with done == TRUE, a successful callout happened, and yield
1273 will be set OK or FAIL according to the response to the RCPT command.
1274 Otherwise, we looped through the hosts but couldn't complete the business.
1275 However, there may be domain-specific information to cache in both cases.
1277 The value of the result field in the new_domain record is ccache_unknown if
1278 there was an error before or with MAIL FROM:, and errno was not zero,
1279 implying some kind of I/O error. We don't want to write the cache in that case.
1280 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1282 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1284 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1287 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1291 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1292 (int)sizeof(dbdata_callout_cache));
1293 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1294 " result=%d postmaster=%d random=%d\n",
1295 new_domain_record.result,
1296 new_domain_record.postmaster_result,
1297 new_domain_record.random_result);
1301 /* If a definite result was obtained for the callout, cache it unless caching
1306 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1308 if (dbm_file == NULL)
1309 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1310 if (dbm_file == NULL)
1312 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1316 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1317 (int)sizeof(dbdata_callout_cache_address));
1318 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1319 (new_address_record.result == ccache_accept)? "positive" : "negative");
1324 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1325 temporary error. If there was only one host, and a response was received, leave
1326 it alone if supplying details. Otherwise, give a generic response. */
1330 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1331 is_recipient? "recipient" : "sender");
1334 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1336 addr->user_message = (!smtp_return_error_details)? dullmsg :
1337 string_sprintf("%s for <%s>.\n"
1338 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1339 "they may be permanently unreachable from this server. In the latter case,\n%s",
1340 dullmsg, addr->address,
1342 "the address will never be accepted."
1344 "you need to change the address or create an MX record for its domain\n"
1345 "if it is supposed to be generally accessible from the Internet.\n"
1346 "Talk to your mail administrator for details.");
1348 /* Force a specific error code */
1350 addr->basic_errno = ERRNO_CALLOUTDEFER;
1353 /* Come here from within the cache-reading code on fast-track exit. */
1356 if (dbm_file != NULL) dbfn_close(dbm_file);
1362 /* Called after recipient-acl to get a cutthrough connection open when
1363 one was requested and a recipient-verify wasn't subsequently done.
1366 open_cutthrough_connection( address_item * addr )
1370 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1371 /* We must use a copy of the address for verification, because it might
1375 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1376 rcpt_count > 1 ? "more" : "start");
1377 (void) verify_address(&addr2, NULL,
1378 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1379 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1381 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1387 /* Send given number of bytes from the buffer */
1389 cutthrough_send(int n)
1391 if(cutthrough.fd < 0)
1396 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1398 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1401 transport_count += n;
1402 ctblock.ptr= ctblock.buffer;
1406 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1413 _cutthrough_puts(uschar * cp, int n)
1417 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1418 if(!cutthrough_send(ctblock.buffersize))
1421 *ctblock.ptr++ = *cp++;
1426 /* Buffered output of counted data block. Return boolean success */
1428 cutthrough_puts(uschar * cp, int n)
1430 if (cutthrough.fd < 0) return TRUE;
1431 if (_cutthrough_puts(cp, n)) return TRUE;
1432 cancel_cutthrough_connection("transmit failed");
1438 _cutthrough_flush_send(void)
1440 int n= ctblock.ptr-ctblock.buffer;
1443 if(!cutthrough_send(n))
1449 /* Send out any bufferred output. Return boolean success. */
1451 cutthrough_flush_send(void)
1453 if (_cutthrough_flush_send()) return TRUE;
1454 cancel_cutthrough_connection("transmit failed");
1460 cutthrough_put_nl(void)
1462 return cutthrough_puts(US"\r\n", 2);
1466 /* Get and check response from cutthrough target */
1468 cutthrough_response(char expect, uschar ** copy)
1470 smtp_inblock inblock;
1471 uschar inbuffer[4096];
1472 uschar responsebuffer[4096];
1474 inblock.buffer = inbuffer;
1475 inblock.buffersize = sizeof(inbuffer);
1476 inblock.ptr = inbuffer;
1477 inblock.ptrend = inbuffer;
1478 inblock.sock = cutthrough.fd;
1479 /* this relies on (inblock.sock == tls_out.active) */
1480 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1481 cancel_cutthrough_connection("target timeout on read");
1486 *copy = cp = string_copy(responsebuffer);
1487 /* Trim the trailing end of line */
1488 cp += Ustrlen(responsebuffer);
1489 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1490 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1493 return responsebuffer[0];
1497 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1499 cutthrough_predata(void)
1501 if(cutthrough.fd < 0)
1504 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1505 cutthrough_puts(US"DATA\r\n", 6);
1506 cutthrough_flush_send();
1508 /* Assume nothing buffered. If it was it gets ignored. */
1509 return cutthrough_response('3', NULL) == '3';
1513 /* fd and use_crlf args only to match write_chunk() */
1515 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1518 while(s && (s2 = Ustrchr(s, '\n')))
1520 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1528 /* Buffered send of headers. Return success boolean. */
1529 /* Expands newlines to wire format (CR,NL). */
1530 /* Also sends header-terminating blank line. */
1532 cutthrough_headers_send(void)
1534 if(cutthrough.fd < 0)
1537 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1538 but having a separate buffered-output function (for now)
1540 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1542 if (!transport_headers_send(&cutthrough.addr, cutthrough.fd,
1543 cutthrough.addr.transport->add_headers,
1544 cutthrough.addr.transport->remove_headers,
1545 &cutthrough_write_chunk, TRUE,
1546 cutthrough.addr.transport->rewrite_rules,
1547 cutthrough.addr.transport->rewrite_existflags))
1550 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1556 close_cutthrough_connection(const char * why)
1558 if(cutthrough.fd >= 0)
1560 /* We could be sending this after a bunch of data, but that is ok as
1561 the only way to cancel the transfer in dataphase is to drop the tcp
1562 conn before the final dot.
1564 ctblock.ptr = ctbuffer;
1565 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1566 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1567 _cutthrough_flush_send();
1568 /* No wait for response */
1571 tls_close(FALSE, TRUE);
1573 (void)close(cutthrough.fd);
1575 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1577 ctblock.ptr = ctbuffer;
1581 cancel_cutthrough_connection(const char * why)
1583 close_cutthrough_connection(why);
1584 cutthrough.delivery = FALSE;
1590 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1591 Log an OK response as a transmission.
1592 Close the connection.
1593 Return smtp response-class digit.
1596 cutthrough_finaldot(void)
1599 address_item * addr;
1600 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1602 /* Assume data finshed with new-line */
1603 if( !cutthrough_puts(US".", 1)
1604 || !cutthrough_put_nl()
1605 || !cutthrough_flush_send()
1607 return cutthrough.addr.message;
1609 res = cutthrough_response('2', &cutthrough.addr.message);
1610 for (addr = &cutthrough.addr; addr; addr = addr->next)
1612 addr->message = cutthrough.addr.message;
1616 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1617 close_cutthrough_connection("delivered");
1621 delivery_log(LOG_MAIN, addr, 0,
1622 US"tmp-reject from cutthrough after DATA:");
1626 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1627 US"rejected after DATA:");
1634 return cutthrough.addr.message;
1639 /*************************************************
1640 * Copy error to toplevel address *
1641 *************************************************/
1643 /* This function is used when a verify fails or defers, to ensure that the
1644 failure or defer information is in the original toplevel address. This applies
1645 when an address is redirected to a single new address, and the failure or
1646 deferral happens to the child address.
1649 vaddr the verify address item
1650 addr the final address item
1653 Returns: the value of YIELD
1657 copy_error(address_item *vaddr, address_item *addr, int yield)
1661 vaddr->message = addr->message;
1662 vaddr->user_message = addr->user_message;
1663 vaddr->basic_errno = addr->basic_errno;
1664 vaddr->more_errno = addr->more_errno;
1665 vaddr->p.address_data = addr->p.address_data;
1666 copyflag(vaddr, addr, af_pass_message);
1674 /**************************************************
1675 * printf that automatically handles TLS if needed *
1676 ***************************************************/
1678 /* This function is used by verify_address() as a substitute for all fprintf()
1679 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1680 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1681 that assumes that we always use the smtp_out FILE* when not using TLS or the
1682 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1683 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1687 f the candidate FILE* to write to
1688 format format string
1689 ... optional arguments
1695 static void PRINTF_FUNCTION(2,3)
1696 respond_printf(FILE *f, const char *format, ...)
1700 va_start(ap, format);
1701 if (smtp_out && (f == smtp_out))
1702 smtp_vprintf(format, ap);
1704 vfprintf(f, format, ap);
1710 /*************************************************
1711 * Verify an email address *
1712 *************************************************/
1714 /* This function is used both for verification (-bv and at other times) and
1715 address testing (-bt), which is indicated by address_test_mode being set.
1718 vaddr contains the address to verify; the next field in this block
1720 f if not NULL, write the result to this file
1721 options various option bits:
1722 vopt_fake_sender => this sender verify is not for the real
1723 sender (it was verify=sender=xxxx or an address from a
1724 header line) - rewriting must not change sender_address
1725 vopt_is_recipient => this is a recipient address, otherwise
1726 it's a sender address - this affects qualification and
1727 rewriting and messages from callouts
1728 vopt_qualify => qualify an unqualified address; else error
1729 vopt_expn => called from SMTP EXPN command
1730 vopt_success_on_redirect => when a new address is generated
1731 the verification instantly succeeds
1733 These ones are used by do_callout() -- the options variable
1736 vopt_callout_fullpm => if postmaster check, do full one
1737 vopt_callout_no_cache => don't use callout cache
1738 vopt_callout_random => do the "random" thing
1739 vopt_callout_recipsender => use real sender for recipient
1740 vopt_callout_recippmaster => use postmaster for recipient
1742 callout if > 0, specifies that callout is required, and gives timeout
1743 for individual commands
1744 callout_overall if > 0, gives overall timeout for the callout function;
1745 if < 0, a default is used (see do_callout())
1746 callout_connect the connection timeout for callouts
1747 se_mailfrom when callout is requested to verify a sender, use this
1748 in MAIL FROM; NULL => ""
1749 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1750 thing and use this as the sender address (may be "")
1752 routed if not NULL, set TRUE if routing succeeded, so we can
1753 distinguish between routing failed and callout failed
1755 Returns: OK address verified
1756 FAIL address failed to verify
1757 DEFER can't tell at present
1761 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1762 int callout_overall, int callout_connect, uschar *se_mailfrom,
1763 uschar *pm_mailfrom, BOOL *routed)
1766 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1767 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1768 BOOL expn = (options & vopt_expn) != 0;
1769 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1772 int verify_type = expn? v_expn :
1773 address_test_mode? v_none :
1774 is_recipient? v_recipient : v_sender;
1775 address_item *addr_list;
1776 address_item *addr_new = NULL;
1777 address_item *addr_remote = NULL;
1778 address_item *addr_local = NULL;
1779 address_item *addr_succeed = NULL;
1780 uschar **failure_ptr = is_recipient?
1781 &recipient_verify_failure : &sender_verify_failure;
1782 uschar *ko_prefix, *cr;
1783 uschar *address = vaddr->address;
1784 uschar *save_sender;
1785 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1787 /* Clear, just in case */
1789 *failure_ptr = NULL;
1791 /* Set up a prefix and suffix for error message which allow us to use the same
1792 output statements both in EXPN mode (where an SMTP response is needed) and when
1793 debugging with an output file. */
1797 ko_prefix = US"553 ";
1800 else ko_prefix = cr = US"";
1802 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1804 if (parse_find_at(address) == NULL)
1806 if ((options & vopt_qualify) == 0)
1809 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1810 ko_prefix, address, cr);
1811 *failure_ptr = US"qualify";
1814 address = rewrite_address_qualify(address, is_recipient);
1819 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1820 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1823 /* Rewrite and report on it. Clear the domain and local part caches - these
1824 may have been set by domains and local part tests during an ACL. */
1826 if (global_rewrite_rules != NULL)
1828 uschar *old = address;
1829 address = rewrite_address(address, is_recipient, FALSE,
1830 global_rewrite_rules, rewrite_existflags);
1833 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1834 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1835 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1839 /* If this is the real sender address, we must update sender_address at
1840 this point, because it may be referred to in the routers. */
1842 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1843 sender_address = address;
1845 /* If the address was rewritten to <> no verification can be done, and we have
1846 to return OK. This rewriting is permitted only for sender addresses; for other
1847 addresses, such rewriting fails. */
1849 if (address[0] == 0) return OK;
1851 /* Flip the legacy TLS-related variables over to the outbound set in case
1852 they're used in the context of a transport used by verification. Reset them
1853 at exit from this routine. */
1855 tls_modify_variables(&tls_out);
1857 /* Save a copy of the sender address for re-instating if we change it to <>
1858 while verifying a sender address (a nice bit of self-reference there). */
1860 save_sender = sender_address;
1862 /* Update the address structure with the possibly qualified and rewritten
1863 address. Set it up as the starting address on the chain of new addresses. */
1865 vaddr->address = address;
1868 /* We need a loop, because an address can generate new addresses. We must also
1869 cope with generated pipes and files at the top level. (See also the code and
1870 comment in deliver.c.) However, it is usually the case that the router for
1871 user's .forward files has its verify flag turned off.
1873 If an address generates more than one child, the loop is used only when
1874 full_info is set, and this can only be set locally. Remote enquiries just get
1875 information about the top level address, not anything that it generated. */
1877 while (addr_new != NULL)
1880 address_item *addr = addr_new;
1882 addr_new = addr->next;
1887 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1888 debug_printf("Considering %s\n", addr->address);
1891 /* Handle generated pipe, file or reply addresses. We don't get these
1892 when handling EXPN, as it does only one level of expansion. */
1894 if (testflag(addr, af_pfr))
1901 if (addr->address[0] == '>')
1903 allow = testflag(addr, af_allow_reply);
1904 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1908 allow = (addr->address[0] == '|')?
1909 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1910 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1913 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1914 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1915 "%s\n", addr->message);
1917 fprintf(f, "\n transport = %s\n", addr->transport->name);
1919 fprintf(f, " *** forbidden ***\n");
1924 /* Just in case some router parameter refers to it. */
1926 return_path = (addr->p.errors_address != NULL)?
1927 addr->p.errors_address : sender_address;
1929 /* Split the address into domain and local part, handling the %-hack if
1930 necessary, and then route it. While routing a sender address, set
1931 $sender_address to <> because that is what it will be if we were trying to
1932 send a bounce to the sender. */
1934 if (routed != NULL) *routed = FALSE;
1935 if ((rc = deliver_split_address(addr)) == OK)
1937 if (!is_recipient) sender_address = null_sender;
1938 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1939 &addr_succeed, verify_type);
1940 sender_address = save_sender; /* Put back the real sender */
1943 /* If routing an address succeeded, set the flag that remembers, for use when
1944 an ACL cached a sender verify (in case a callout fails). Then if routing set
1945 up a list of hosts or the transport has a host list, and the callout option
1946 is set, and we aren't in a host checking run, do the callout verification,
1947 and set another flag that notes that a callout happened. */
1951 if (routed != NULL) *routed = TRUE;
1954 host_item *host_list = addr->host_list;
1956 /* Make up some data for use in the case where there is no remote
1959 transport_feedback tf = {
1960 NULL, /* interface (=> any) */
1961 US"smtp", /* port */
1962 US"smtp", /* protocol */
1964 US"$smtp_active_hostname", /* helo_data */
1965 FALSE, /* hosts_override */
1966 FALSE, /* hosts_randomize */
1967 FALSE, /* gethostbyname */
1968 TRUE, /* qualify_single */
1969 FALSE /* search_parents */
1972 /* If verification yielded a remote transport, we want to use that
1973 transport's options, so as to mimic what would happen if we were really
1974 sending a message to this address. */
1976 if (addr->transport != NULL && !addr->transport->info->local)
1978 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1980 /* If the transport has hosts and the router does not, or if the
1981 transport is configured to override the router's hosts, we must build a
1982 host list of the transport's hosts, and find the IP addresses */
1984 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1987 const uschar *save_deliver_domain = deliver_domain;
1988 uschar *save_deliver_localpart = deliver_localpart;
1990 host_list = NULL; /* Ignore the router's hosts */
1992 deliver_domain = addr->domain;
1993 deliver_localpart = addr->local_part;
1994 s = expand_string(tf.hosts);
1995 deliver_domain = save_deliver_domain;
1996 deliver_localpart = save_deliver_localpart;
2000 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
2001 "\"%s\" in %s transport for callout: %s", tf.hosts,
2002 addr->transport->name, expand_string_message);
2007 host_item *host, *nexthost;
2008 host_build_hostlist(&host_list, s, tf.hosts_randomize);
2010 /* Just ignore failures to find a host address. If we don't manage
2011 to find any addresses, the callout will defer. Note that more than
2012 one address may be found for a single host, which will result in
2013 additional host items being inserted into the chain. Hence we must
2014 save the next host first. */
2016 flags = HOST_FIND_BY_A;
2017 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2018 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2020 for (host = host_list; host != NULL; host = nexthost)
2022 nexthost = host->next;
2023 if (tf.gethostbyname ||
2024 string_is_ip_address(host->name, NULL) != 0)
2025 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
2028 uschar * d_request = NULL, * d_require = NULL;
2029 if (Ustrcmp(addr->transport->driver_name, "smtp") == 0)
2031 smtp_transport_options_block * ob =
2032 (smtp_transport_options_block *)
2033 addr->transport->options_block;
2034 d_request = ob->dnssec_request_domains;
2035 d_require = ob->dnssec_require_domains;
2038 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2039 d_request, d_require, NULL, NULL);
2046 /* Can only do a callout if we have at least one host! If the callout
2047 fails, it will have set ${sender,recipient}_verify_failure. */
2049 if (host_list != NULL)
2051 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
2052 if (host_checking && !host_checking_callout)
2055 debug_printf("... callout omitted by default when host testing\n"
2056 "(Use -bhc if you want the callouts to happen.)\n");
2061 deliver_set_expansions(addr);
2063 verify_mode = is_recipient ? US"R" : US"S";
2064 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
2065 callout_connect, options, se_mailfrom, pm_mailfrom);
2071 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
2072 "transport provided a host list\n");
2077 /* Otherwise, any failure is a routing failure */
2079 else *failure_ptr = US"route";
2081 /* A router may return REROUTED if it has set up a child address as a result
2082 of a change of domain name (typically from widening). In this case we always
2083 want to continue to verify the new child. */
2085 if (rc == REROUTED) continue;
2087 /* Handle hard failures */
2094 address_item *p = addr->parent;
2096 respond_printf(f, "%s%s %s", ko_prefix,
2097 full_info? addr->address : address,
2098 address_test_mode? "is undeliverable" : "failed to verify");
2099 if (!expn && admin_user)
2101 if (addr->basic_errno > 0)
2102 respond_printf(f, ": %s", strerror(addr->basic_errno));
2103 if (addr->message != NULL)
2104 respond_printf(f, ": %s", addr->message);
2107 /* Show parents iff doing full info */
2109 if (full_info) while (p != NULL)
2111 respond_printf(f, "%s\n <-- %s", cr, p->address);
2114 respond_printf(f, "%s\n", cr);
2116 cancel_cutthrough_connection("routing hard fail");
2120 yield = copy_error(vaddr, addr, FAIL);
2128 else if (rc == DEFER)
2133 address_item *p = addr->parent;
2134 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
2135 full_info? addr->address : address);
2136 if (!expn && admin_user)
2138 if (addr->basic_errno > 0)
2139 respond_printf(f, ": %s", strerror(addr->basic_errno));
2140 if (addr->message != NULL)
2141 respond_printf(f, ": %s", addr->message);
2142 else if (addr->basic_errno <= 0)
2143 respond_printf(f, ": unknown error");
2146 /* Show parents iff doing full info */
2148 if (full_info) while (p != NULL)
2150 respond_printf(f, "%s\n <-- %s", cr, p->address);
2153 respond_printf(f, "%s\n", cr);
2155 cancel_cutthrough_connection("routing soft fail");
2159 yield = copy_error(vaddr, addr, DEFER);
2162 else if (yield == OK) yield = DEFER;
2165 /* If we are handling EXPN, we do not want to continue to route beyond
2166 the top level (whose address is in "address"). */
2170 uschar *ok_prefix = US"250-";
2171 if (addr_new == NULL)
2173 if (addr_local == NULL && addr_remote == NULL)
2174 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2176 respond_printf(f, "250 <%s>\r\n", address);
2178 else while (addr_new != NULL)
2180 address_item *addr2 = addr_new;
2181 addr_new = addr2->next;
2182 if (addr_new == NULL) ok_prefix = US"250 ";
2183 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2189 /* Successful routing other than EXPN. */
2193 /* Handle successful routing when short info wanted. Otherwise continue for
2194 other (generated) addresses. Short info is the operational case. Full info
2195 can be requested only when debug_selector != 0 and a file is supplied.
2197 There is a conflict between the use of aliasing as an alternate email
2198 address, and as a sort of mailing list. If an alias turns the incoming
2199 address into just one address (e.g. J.Caesar->jc44) you may well want to
2200 carry on verifying the generated address to ensure it is valid when
2201 checking incoming mail. If aliasing generates multiple addresses, you
2202 probably don't want to do this. Exim therefore treats the generation of
2203 just a single new address as a special case, and continues on to verify the
2204 generated address. */
2206 if (!full_info && /* Stop if short info wanted AND */
2207 (((addr_new == NULL || /* No new address OR */
2208 addr_new->next != NULL || /* More than one new address OR */
2209 testflag(addr_new, af_pfr))) /* New address is pfr */
2211 (addr_new != NULL && /* At least one new address AND */
2212 success_on_redirect))) /* success_on_redirect is set */
2214 if (f != NULL) fprintf(f, "%s %s\n", address,
2215 address_test_mode? "is deliverable" : "verified");
2217 /* If we have carried on to verify a child address, we want the value
2218 of $address_data to be that of the child */
2220 vaddr->p.address_data = addr->p.address_data;
2225 } /* Loop for generated addresses */
2227 /* Display the full results of the successful routing, including any generated
2228 addresses. Control gets here only when full_info is set, which requires f not
2229 to be NULL, and this occurs only when a top-level verify is called with the
2230 debugging switch on.
2232 If there are no local and no remote addresses, and there were no pipes, files,
2233 or autoreplies, and there were no errors or deferments, the message is to be
2234 discarded, usually because of the use of :blackhole: in an alias file. */
2236 if (allok && addr_local == NULL && addr_remote == NULL)
2238 fprintf(f, "mail to %s is discarded\n", address);
2242 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2244 while (addr_list != NULL)
2246 address_item *addr = addr_list;
2247 address_item *p = addr->parent;
2248 addr_list = addr->next;
2250 fprintf(f, "%s", CS addr->address);
2251 #ifdef EXPERIMENTAL_SRS
2252 if(addr->p.srs_sender)
2253 fprintf(f, " [srs = %s]", addr->p.srs_sender);
2256 /* If the address is a duplicate, show something about it. */
2258 if (!testflag(addr, af_pfr))
2261 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
2262 fprintf(f, " [duplicate, would not be delivered]");
2263 else tree_add_duplicate(addr->unique, addr);
2266 /* Now show its parents */
2270 fprintf(f, "\n <-- %s", p->address);
2275 /* Show router, and transport */
2277 fprintf(f, "router = %s, ", addr->router->name);
2278 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
2279 addr->transport->name);
2281 /* Show any hosts that are set up by a router unless the transport
2282 is going to override them; fiddle a bit to get a nice format. */
2284 if (addr->host_list != NULL && addr->transport != NULL &&
2285 !addr->transport->overrides_hosts)
2290 for (h = addr->host_list; h != NULL; h = h->next)
2292 int len = Ustrlen(h->name);
2293 if (len > maxlen) maxlen = len;
2294 len = (h->address != NULL)? Ustrlen(h->address) : 7;
2295 if (len > maxaddlen) maxaddlen = len;
2297 for (h = addr->host_list; h != NULL; h = h->next)
2299 int len = Ustrlen(h->name);
2300 fprintf(f, " host %s ", h->name);
2301 while (len++ < maxlen) fprintf(f, " ");
2302 if (h->address != NULL)
2304 fprintf(f, "[%s] ", h->address);
2305 len = Ustrlen(h->address);
2307 else if (!addr->transport->info->local) /* Omit [unknown] for local */
2309 fprintf(f, "[unknown] ");
2313 while (len++ < maxaddlen) fprintf(f," ");
2314 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
2315 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2316 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2323 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2324 the -bv or -bt case). */
2327 tls_modify_variables(&tls_in);
2335 /*************************************************
2336 * Check headers for syntax errors *
2337 *************************************************/
2339 /* This function checks those header lines that contain addresses, and verifies
2340 that all the addresses therein are syntactially correct.
2343 msgptr where to put an error message
2350 verify_check_headers(uschar **msgptr)
2356 for (h = header_list; h != NULL && yield == OK; h = h->next)
2358 if (h->type != htype_from &&
2359 h->type != htype_reply_to &&
2360 h->type != htype_sender &&
2361 h->type != htype_to &&
2362 h->type != htype_cc &&
2363 h->type != htype_bcc)
2366 colon = Ustrchr(h->text, ':');
2368 while (isspace(*s)) s++;
2370 /* Loop for multiple addresses in the header, enabling group syntax. Note
2371 that we have to reset this after the header has been scanned. */
2373 parse_allow_group = TRUE;
2377 uschar *ss = parse_find_address_end(s, FALSE);
2378 uschar *recipient, *errmess;
2379 int terminator = *ss;
2380 int start, end, domain;
2382 /* Temporarily terminate the string at this point, and extract the
2383 operative address within, allowing group syntax. */
2386 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2389 /* Permit an unqualified address only if the message is local, or if the
2390 sending host is configured to be permitted to send them. */
2392 if (recipient != NULL && domain == 0)
2394 if (h->type == htype_from || h->type == htype_sender)
2396 if (!allow_unqualified_sender) recipient = NULL;
2400 if (!allow_unqualified_recipient) recipient = NULL;
2402 if (recipient == NULL) errmess = US"unqualified address not permitted";
2405 /* It's an error if no address could be extracted, except for the special
2406 case of an empty address. */
2408 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2410 uschar *verb = US"is";
2415 /* Arrange not to include any white space at the end in the
2416 error message or the header name. */
2418 while (t > s && isspace(t[-1])) t--;
2419 while (tt > h->text && isspace(tt[-1])) tt--;
2421 /* Add the address that failed to the error message, since in a
2422 header with very many addresses it is sometimes hard to spot
2423 which one is at fault. However, limit the amount of address to
2424 quote - cases have been seen where, for example, a missing double
2425 quote in a humungous To: header creates an "address" that is longer
2426 than string_sprintf can handle. */
2435 /* deconst cast ok as we're passing a non-const to string_printing() */
2436 *msgptr = US string_printing(
2437 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2438 errmess, tt - h->text, h->text, verb, len, s));
2441 break; /* Out of address loop */
2444 /* Advance to the next address */
2446 s = ss + (terminator? 1:0);
2447 while (isspace(*s)) s++;
2448 } /* Next address */
2450 parse_allow_group = FALSE;
2451 parse_found_group = FALSE;
2452 } /* Next header unless yield has been set FALSE */
2458 /*************************************************
2459 * Check header names for 8-bit characters *
2460 *************************************************/
2462 /* This function checks for invalid charcters in header names. See
2463 RFC 5322, 2.2. and RFC 6532, 3.
2466 msgptr where to put an error message
2473 verify_check_header_names_ascii(uschar **msgptr)
2478 for (h = header_list; h != NULL; h = h->next)
2480 colon = Ustrchr(h->text, ':');
2481 for(s = h->text; s < colon; s++)
2483 if ((*s < 33) || (*s > 126))
2485 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2486 colon - h->text, h->text);
2494 /*************************************************
2495 * Check for blind recipients *
2496 *************************************************/
2498 /* This function checks that every (envelope) recipient is mentioned in either
2499 the To: or Cc: header lines, thus detecting blind carbon copies.
2501 There are two ways of scanning that could be used: either scan the header lines
2502 and tick off the recipients, or scan the recipients and check the header lines.
2503 The original proposed patch did the former, but I have chosen to do the latter,
2504 because (a) it requires no memory and (b) will use fewer resources when there
2505 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2508 Returns: OK if there are no blind recipients
2509 FAIL if there is at least one blind recipient
2513 verify_check_notblind(void)
2516 for (i = 0; i < recipients_count; i++)
2520 uschar *address = recipients_list[i].address;
2522 for (h = header_list; !found && h != NULL; h = h->next)
2526 if (h->type != htype_to && h->type != htype_cc) continue;
2528 colon = Ustrchr(h->text, ':');
2530 while (isspace(*s)) s++;
2532 /* Loop for multiple addresses in the header, enabling group syntax. Note
2533 that we have to reset this after the header has been scanned. */
2535 parse_allow_group = TRUE;
2539 uschar *ss = parse_find_address_end(s, FALSE);
2540 uschar *recipient,*errmess;
2541 int terminator = *ss;
2542 int start, end, domain;
2544 /* Temporarily terminate the string at this point, and extract the
2545 operative address within, allowing group syntax. */
2548 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2551 /* If we found a valid recipient that has a domain, compare it with the
2552 envelope recipient. Local parts are compared case-sensitively, domains
2553 case-insensitively. By comparing from the start with length "domain", we
2554 include the "@" at the end, which ensures that we are comparing the whole
2555 local part of each address. */
2557 if (recipient != NULL && domain != 0)
2559 found = Ustrncmp(recipient, address, domain) == 0 &&
2560 strcmpic(recipient + domain, address + domain) == 0;
2564 /* Advance to the next address */
2566 s = ss + (terminator? 1:0);
2567 while (isspace(*s)) s++;
2568 } /* Next address */
2570 parse_allow_group = FALSE;
2571 parse_found_group = FALSE;
2572 } /* Next header (if found is false) */
2574 if (!found) return FAIL;
2575 } /* Next recipient */
2582 /*************************************************
2583 * Find if verified sender *
2584 *************************************************/
2586 /* Usually, just a single address is verified as the sender of the message.
2587 However, Exim can be made to verify other addresses as well (often related in
2588 some way), and this is useful in some environments. There may therefore be a
2589 chain of such addresses that have previously been tested. This function finds
2590 whether a given address is on the chain.
2592 Arguments: the address to be verified
2593 Returns: pointer to an address item, or NULL
2597 verify_checked_sender(uschar *sender)
2600 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2601 if (Ustrcmp(sender, addr->address) == 0) break;
2609 /*************************************************
2610 * Get valid header address *
2611 *************************************************/
2613 /* Scan the originator headers of the message, looking for an address that
2614 verifies successfully. RFC 822 says:
2616 o The "Sender" field mailbox should be sent notices of
2617 any problems in transport or delivery of the original
2618 messages. If there is no "Sender" field, then the
2619 "From" field mailbox should be used.
2621 o If the "Reply-To" field exists, then the reply should
2622 go to the addresses indicated in that field and not to
2623 the address(es) indicated in the "From" field.
2625 So we check a Sender field if there is one, else a Reply_to field, else a From
2626 field. As some strange messages may have more than one of these fields,
2627 especially if they are resent- fields, check all of them if there is more than
2631 user_msgptr points to where to put a user error message
2632 log_msgptr points to where to put a log error message
2633 callout timeout for callout check (passed to verify_address())
2634 callout_overall overall callout timeout (ditto)
2635 callout_connect connect callout timeout (ditto)
2636 se_mailfrom mailfrom for verify; NULL => ""
2637 pm_mailfrom sender for pm callout check (passed to verify_address())
2638 options callout options (passed to verify_address())
2639 verrno where to put the address basic_errno
2641 If log_msgptr is set to something without setting user_msgptr, the caller
2642 normally uses log_msgptr for both things.
2644 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2645 FAIL is given if no appropriate headers are found
2649 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2650 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2651 uschar *pm_mailfrom, int options, int *verrno)
2653 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2658 for (i = 0; i < 3 && !done; i++)
2661 for (h = header_list; h != NULL && !done; h = h->next)
2663 int terminator, new_ok;
2664 uschar *s, *ss, *endname;
2666 if (h->type != header_types[i]) continue;
2667 s = endname = Ustrchr(h->text, ':') + 1;
2669 /* Scan the addresses in the header, enabling group syntax. Note that we
2670 have to reset this after the header has been scanned. */
2672 parse_allow_group = TRUE;
2676 address_item *vaddr;
2678 while (isspace(*s) || *s == ',') s++;
2679 if (*s == 0) break; /* End of header */
2681 ss = parse_find_address_end(s, FALSE);
2683 /* The terminator is a comma or end of header, but there may be white
2684 space preceding it (including newline for the last address). Move back
2685 past any white space so we can check against any cached envelope sender
2686 address verifications. */
2688 while (isspace(ss[-1])) ss--;
2692 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2693 (int)(endname - h->text), h->text, s);
2695 /* See if we have already verified this address as an envelope sender,
2696 and if so, use the previous answer. */
2698 vaddr = verify_checked_sender(s);
2700 if (vaddr != NULL && /* Previously checked */
2701 (callout <= 0 || /* No callout needed; OR */
2702 vaddr->special_action > 256)) /* Callout was done */
2704 new_ok = vaddr->special_action & 255;
2705 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2706 *ss = terminator; /* Restore shortened string */
2709 /* Otherwise we run the verification now. We must restore the shortened
2710 string before running the verification, so the headers are correct, in
2711 case there is any rewriting. */
2715 int start, end, domain;
2716 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2721 /* If we found an empty address, just carry on with the next one, but
2722 kill the message. */
2724 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2731 /* If verification failed because of a syntax error, fail this
2732 function, and ensure that the failing address gets added to the error
2735 if (address == NULL)
2738 while (ss > s && isspace(ss[-1])) ss--;
2739 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2740 "scanning for sender: %s in \"%.*s\"",
2741 endname - h->text, h->text, *log_msgptr, ss - s, s);
2747 /* Else go ahead with the sender verification. But it isn't *the*
2748 sender of the message, so set vopt_fake_sender to stop sender_address
2749 being replaced after rewriting or qualification. */
2753 vaddr = deliver_make_addr(address, FALSE);
2754 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2755 callout, callout_overall, callout_connect, se_mailfrom,
2760 /* We now have the result, either newly found, or cached. If we are
2761 giving out error details, set a specific user error. This means that the
2762 last of these will be returned to the user if all three fail. We do not
2763 set a log message - the generic one below will be used. */
2767 *verrno = vaddr->basic_errno;
2768 if (smtp_return_error_details)
2770 *user_msgptr = string_sprintf("Rejected after DATA: "
2771 "could not verify \"%.*s\" header address\n%s: %s",
2772 endname - h->text, h->text, vaddr->address, vaddr->message);
2776 /* Success or defer */
2785 if (new_ok == DEFER) yield = DEFER;
2787 /* Move on to any more addresses in the header */
2790 } /* Next address */
2792 parse_allow_group = FALSE;
2793 parse_found_group = FALSE;
2794 } /* Next header, unless done */
2795 } /* Next header type unless done */
2797 if (yield == FAIL && *log_msgptr == NULL)
2798 *log_msgptr = US"there is no valid sender in any header line";
2800 if (yield == DEFER && *log_msgptr == NULL)
2801 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2809 /*************************************************
2810 * Get RFC 1413 identification *
2811 *************************************************/
2813 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2814 the timeout is set to zero, then the query is not done. There may also be lists
2815 of hosts and nets which are exempt. To guard against malefactors sending
2816 non-printing characters which could, for example, disrupt a message's headers,
2817 make sure the string consists of printing characters only.
2820 port the port to connect to; usually this is IDENT_PORT (113), but when
2821 running in the test harness with -bh a different value is used.
2825 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2829 verify_get_ident(int port)
2831 int sock, host_af, qlen;
2832 int received_sender_port, received_interface_port, n;
2834 uschar buffer[2048];
2836 /* Default is no ident. Check whether we want to do an ident check for this
2839 sender_ident = NULL;
2840 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2843 DEBUG(D_ident) debug_printf("doing ident callback\n");
2845 /* Set up a connection to the ident port of the remote host. Bind the local end
2846 to the incoming interface address. If the sender host address is an IPv6
2847 address, the incoming interface address will also be IPv6. */
2849 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2850 sock = ip_socket(SOCK_STREAM, host_af);
2851 if (sock < 0) return;
2853 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2855 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2860 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2863 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2865 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2866 sender_host_address);
2870 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2871 sender_host_address, strerror(errno));
2876 /* Construct and send the query. */
2878 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2879 qlen = Ustrlen(buffer);
2880 if (send(sock, buffer, qlen, 0) < 0)
2882 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2886 /* Read a response line. We put it into the rest of the buffer, using several
2887 recv() calls if necessary. */
2895 int size = sizeof(buffer) - (p - buffer);
2897 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2898 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2899 if (count <= 0) goto END_OFF; /* Read error or EOF */
2901 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2902 generous, and accept a plain \n terminator as well. The only illegal
2905 for (pp = p; pp < p + count; pp++)
2907 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2910 if (pp[-1] == '\r') pp--;
2912 goto GOT_DATA; /* Break out of both loops */
2916 /* Reached the end of the data without finding \n. Let the loop continue to
2917 read some more, if there is room. */
2924 /* We have received a line of data. Check it carefully. It must start with the
2925 same two port numbers that we sent, followed by data as defined by the RFC. For
2928 12345 , 25 : USERID : UNIX :root
2930 However, the amount of white space may be different to what we sent. In the
2931 "osname" field there may be several sub-fields, comma separated. The data we
2932 actually want to save follows the third colon. Some systems put leading spaces
2933 in it - we discard those. */
2935 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2936 &received_interface_port, &n) != 2 ||
2937 received_sender_port != sender_host_port ||
2938 received_interface_port != interface_port)
2941 p = buffer + qlen + n;
2942 while(isspace(*p)) p++;
2943 if (*p++ != ':') goto END_OFF;
2944 while(isspace(*p)) p++;
2945 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2947 while(isspace(*p)) p++;
2948 if (*p++ != ':') goto END_OFF;
2949 while (*p != 0 && *p != ':') p++;
2950 if (*p++ == 0) goto END_OFF;
2951 while(isspace(*p)) p++;
2952 if (*p == 0) goto END_OFF;
2954 /* The rest of the line is the data we want. We turn it into printing
2955 characters when we save it, so that it cannot mess up the format of any logging
2956 or Received: lines into which it gets inserted. We keep a maximum of 127
2957 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2959 sender_ident = US string_printing(string_copyn(p, 127));
2960 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2970 /*************************************************
2971 * Match host to a single host-list item *
2972 *************************************************/
2974 /* This function compares a host (name or address) against a single item
2975 from a host list. The host name gets looked up if it is needed and is not
2976 already known. The function is called from verify_check_this_host() via
2977 match_check_list(), which is why most of its arguments are in a single block.
2980 arg the argument block (see below)
2981 ss the host-list item
2982 valueptr where to pass back looked up data, or NULL
2983 error for error message when returning ERROR
2986 host_name (a) the host name, or
2987 (b) NULL, implying use sender_host_name and
2988 sender_host_aliases, looking them up if required, or
2989 (c) the empty string, meaning that only IP address matches
2991 host_address the host address
2992 host_ipv4 the IPv4 address taken from an IPv6 one
2996 DEFER lookup deferred
2997 ERROR (a) failed to find the host name or IP address, or
2998 (b) unknown lookup type specified, or
2999 (c) host name encountered when only IP addresses are
3004 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
3006 check_host_block *cb = (check_host_block *)arg;
3009 BOOL iplookup = FALSE;
3010 BOOL isquery = FALSE;
3011 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
3016 /* Optimize for the special case when the pattern is "*". */
3018 if (*ss == '*' && ss[1] == 0) return OK;
3020 /* If the pattern is empty, it matches only in the case when there is no host -
3021 this can occur in ACL checking for SMTP input using the -bs option. In this
3022 situation, the host address is the empty string. */
3024 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
3025 if (*ss == 0) return FAIL;
3027 /* If the pattern is precisely "@" then match against the primary host name,
3028 provided that host name matching is permitted; if it's "@[]" match against the
3029 local host's IP addresses. */
3035 if (isiponly) return ERROR;
3036 ss = primary_hostname;
3038 else if (Ustrcmp(ss, "@[]") == 0)
3040 ip_address_item *ip;
3041 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
3042 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
3047 /* If the pattern is an IP address, optionally followed by a bitmask count, do
3048 a (possibly masked) comparision with the current IP address. */
3050 if (string_is_ip_address(ss, &maskoffset) != 0)
3051 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
3053 /* The pattern is not an IP address. A common error that people make is to omit
3054 one component of an IPv4 address, either by accident, or believing that, for
3055 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,
3056 which it isn't. (Those applications that do accept 1.2.3 as an IP address
3057 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
3058 ancient specification.) To aid in debugging these cases, we give a specific
3059 error if the pattern contains only digits and dots or contains a slash preceded
3060 only by digits and dots (a slash at the start indicates a file name and of
3061 course slashes may be present in lookups, but not preceded only by digits and
3064 for (t = ss; isdigit(*t) || *t == '.'; t++);
3065 if (*t == 0 || (*t == '/' && t != ss))
3067 *error = US"malformed IPv4 address or address mask";
3071 /* See if there is a semicolon in the pattern */
3073 semicolon = Ustrchr(ss, ';');
3075 /* If we are doing an IP address only match, then all lookups must be IP
3076 address lookups, even if there is no "net-". */
3080 iplookup = semicolon != NULL;
3083 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
3084 a lookup on a masked IP network, in textual form. We obey this code even if we
3085 have already set iplookup, so as to skip over the "net-" prefix and to set the
3086 mask length. The net- stuff really only applies to single-key lookups where the
3087 key is implicit. For query-style lookups the key is specified in the query.
3088 From release 4.30, the use of net- for query style is no longer needed, but we
3089 retain it for backward compatibility. */
3091 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
3094 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
3095 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
3096 iplookup = (*t++ == '-');
3100 /* Do the IP address lookup if that is indeed what we have */
3108 uschar *filename, *key, *result;
3111 /* Find the search type */
3113 search_type = search_findtype(t, semicolon - t);
3115 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3116 search_error_message);
3118 /* Adjust parameters for the type of lookup. For a query-style lookup, there
3119 is no file name, and the "key" is just the query. For query-style with a file
3120 name, we have to fish the file off the start of the query. For a single-key
3121 lookup, the key is the current IP address, masked appropriately, and
3122 reconverted to text form, with the mask appended. For IPv6 addresses, specify
3123 dot separators instead of colons, except when the lookup type is "iplsearch".
3126 if (mac_islookup(search_type, lookup_absfilequery))
3128 filename = semicolon + 1;
3130 while (*key != 0 && !isspace(*key)) key++;
3131 filename = string_copyn(filename, key - filename);
3132 while (isspace(*key)) key++;
3134 else if (mac_islookup(search_type, lookup_querystyle))
3137 key = semicolon + 1;
3139 else /* Single-key style */
3141 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3143 insize = host_aton(cb->host_address, incoming);
3144 host_mask(insize, incoming, mlen);
3145 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3147 filename = semicolon + 1;
3150 /* Now do the actual lookup; note that there is no search_close() because
3151 of the caching arrangements. */
3153 handle = search_open(filename, search_type, 0, NULL, NULL);
3154 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3155 search_error_message);
3156 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3157 if (valueptr != NULL) *valueptr = result;
3158 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3161 /* The pattern is not an IP address or network reference of any kind. That is,
3162 it is a host name pattern. If this is an IP only match, there's an error in the
3167 *error = US"cannot match host name in match_ip list";
3171 /* Check the characters of the pattern to see if they comprise only letters,
3172 digits, full stops, and hyphens (the constituents of domain names). Allow
3173 underscores, as they are all too commonly found. Sigh. Also, if
3174 allow_utf8_domains is set, allow top-bit characters. */
3176 for (t = ss; *t != 0; t++)
3177 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3178 (!allow_utf8_domains || *t < 128)) break;
3180 /* If the pattern is a complete domain name, with no fancy characters, look up
3181 its IP address and match against that. Note that a multi-homed host will add
3182 items to the chain. */
3193 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3194 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3197 for (hh = &h; hh != NULL; hh = hh->next)
3199 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3203 if (rc == HOST_FIND_AGAIN) return DEFER;
3204 *error = string_sprintf("failed to find IP address for %s", ss);
3208 /* Almost all subsequent comparisons require the host name, and can be done
3209 using the general string matching function. When this function is called for
3210 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3211 must use sender_host_name and its aliases, looking them up if necessary. */
3213 if (cb->host_name != NULL) /* Explicit host name given */
3214 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3217 /* Host name not given; in principle we need the sender host name and its
3218 aliases. However, for query-style lookups, we do not need the name if the
3219 query does not contain $sender_host_name. From release 4.23, a reference to
3220 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3223 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3225 const uschar *affix;
3226 int partial, affixlen, starflags, id;
3229 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3232 if (id < 0) /* Unknown lookup type */
3234 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3235 search_error_message, ss);
3238 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3243 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3246 case DEFER: return DEFER;
3247 default: return FAIL;
3251 /* Not a query-style lookup; must ensure the host name is present, and then we
3252 do a check on the name and all its aliases. */
3254 if (sender_host_name == NULL)
3256 HDEBUG(D_host_lookup)
3257 debug_printf("sender host name required, to match against %s\n", ss);
3258 if (host_lookup_failed || host_name_lookup() != OK)
3260 *error = string_sprintf("failed to find host name for %s",
3261 sender_host_address);;
3264 host_build_sender_fullhost();
3267 /* Match on the sender host name, using the general matching function */
3269 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3273 case DEFER: return DEFER;
3276 /* If there are aliases, try matching on them. */
3278 aliases = sender_host_aliases;
3279 while (*aliases != NULL)
3281 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3284 case DEFER: return DEFER;
3293 /*************************************************
3294 * Check a specific host matches a host list *
3295 *************************************************/
3297 /* This function is passed a host list containing items in a number of
3298 different formats and the identity of a host. Its job is to determine whether
3299 the given host is in the set of hosts defined by the list. The host name is
3300 passed as a pointer so that it can be looked up if needed and not already
3301 known. This is commonly the case when called from verify_check_host() to check
3302 an incoming connection. When called from elsewhere the host name should usually
3305 This function is now just a front end to match_check_list(), which runs common
3306 code for scanning a list. We pass it the check_host() function to perform a
3310 listptr pointer to the host list
3311 cache_bits pointer to cache for named lists, or NULL
3312 host_name the host name or NULL, implying use sender_host_name and
3313 sender_host_aliases, looking them up if required
3314 host_address the IP address
3315 valueptr if not NULL, data from a lookup is passed back here
3317 Returns: OK if the host is in the defined set
3318 FAIL if the host is not in the defined set,
3319 DEFER if a data lookup deferred (not a host lookup)
3321 If the host name was needed in order to make a comparison, and could not be
3322 determined from the IP address, the result is FAIL unless the item
3323 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3326 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3327 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3330 unsigned int *local_cache_bits = cache_bits;
3331 const uschar *save_host_address = deliver_host_address;
3332 check_host_block cb;
3333 cb.host_name = host_name;
3334 cb.host_address = host_address;
3336 if (valueptr != NULL) *valueptr = NULL;
3338 /* If the host address starts off ::ffff: it is an IPv6 address in
3339 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3342 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3343 host_address + 7 : host_address;
3345 /* During the running of the check, put the IP address into $host_address. In
3346 the case of calls from the smtp transport, it will already be there. However,
3347 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3348 the safe side, any existing setting is preserved, though as I write this
3349 (November 2004) I can't see any cases where it is actually needed. */
3351 deliver_host_address = host_address;
3352 rc = match_check_list(
3353 listptr, /* the list */
3354 0, /* separator character */
3355 &hostlist_anchor, /* anchor pointer */
3356 &local_cache_bits, /* cache pointer */
3357 check_host, /* function for testing */
3358 &cb, /* argument for function */
3359 MCL_HOST, /* type of check */
3360 (host_address == sender_host_address)?
3361 US"host" : host_address, /* text for debugging */
3362 valueptr); /* where to pass back data */
3363 deliver_host_address = save_host_address;
3370 /*************************************************
3371 * Check the given host item matches a list *
3372 *************************************************/
3374 verify_check_given_host(uschar **listptr, host_item *host)
3376 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3379 /*************************************************
3380 * Check the remote host matches a list *
3381 *************************************************/
3383 /* This is a front end to verify_check_this_host(), created because checking
3384 the remote host is a common occurrence. With luck, a good compiler will spot
3385 the tail recursion and optimize it. If there's no host address, this is
3386 command-line SMTP input - check against an empty string for the address.
3389 listptr pointer to the host list
3391 Returns: the yield of verify_check_this_host(),
3392 i.e. OK, FAIL, or DEFER
3396 verify_check_host(uschar **listptr)
3398 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3399 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3406 /*************************************************
3407 * Invert an IP address *
3408 *************************************************/
3410 /* Originally just used for DNS xBL lists, now also used for the
3411 reverse_ip expansion operator.
3414 buffer where to put the answer
3415 address the address to invert
3419 invert_address(uschar *buffer, uschar *address)
3422 uschar *bptr = buffer;
3424 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3425 to the IPv4 part only. */
3427 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3429 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3432 if (host_aton(address, bin) == 1)
3436 for (i = 0; i < 4; i++)
3438 sprintf(CS bptr, "%d.", x & 255);
3439 while (*bptr) bptr++;
3444 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3445 in any DNS black lists, and the format in which they will be looked up is
3446 unknown. This is just a guess. */
3452 for (j = 3; j >= 0; j--)
3455 for (i = 0; i < 8; i++)
3457 sprintf(CS bptr, "%x.", x & 15);
3458 while (*bptr) bptr++;
3465 /* Remove trailing period -- this is needed so that both arbitrary
3466 dnsbl keydomains and inverted addresses may be combined with the
3467 same format string, "%s.%s" */
3474 /*************************************************
3475 * Perform a single dnsbl lookup *
3476 *************************************************/
3478 /* This function is called from verify_check_dnsbl() below. It is also called
3479 recursively from within itself when domain and domain_txt are different
3480 pointers, in order to get the TXT record from the alternate domain.
3483 domain the outer dnsbl domain
3484 domain_txt alternate domain to lookup TXT record on success; when the
3485 same domain is to be used, domain_txt == domain (that is,
3486 the pointers must be identical, not just the text)
3487 keydomain the current keydomain (for debug message)
3488 prepend subdomain to lookup (like keydomain, but
3489 reversed if IP address)
3490 iplist the list of matching IP addresses, or NULL for "any"
3491 bitmask true if bitmask matching is wanted
3492 match_type condition for 'succeed' result
3493 0 => Any RR in iplist (=)
3494 1 => No RR in iplist (!=)
3495 2 => All RRs in iplist (==)
3496 3 => Some RRs not in iplist (!==)
3497 the two bits are defined as MT_NOT and MT_ALL
3498 defer_return what to return for a defer
3500 Returns: OK if lookup succeeded
3505 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3506 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3512 dnsbl_cache_block *cb;
3513 int old_pool = store_pool;
3514 uschar query[256]; /* DNS domain max length */
3516 /* Construct the specific query domainname */
3518 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3520 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3521 "(ignored): %s...", query);
3525 /* Look for this query in the cache. */
3527 t = tree_search(dnsbl_cache, query);
3529 /* If not cached from a previous lookup, we must do a DNS lookup, and
3530 cache the result in permanent memory. */
3534 store_pool = POOL_PERM;
3536 /* Set up a tree entry to cache the lookup */
3538 t = store_get(sizeof(tree_node) + Ustrlen(query));
3539 Ustrcpy(t->name, query);
3540 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3541 (void)tree_insertnode(&dnsbl_cache, t);
3543 /* Do the DNS loopup . */
3545 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3546 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3547 cb->text_set = FALSE;
3551 /* If the lookup succeeded, cache the RHS address. The code allows for
3552 more than one address - this was for complete generality and the possible
3553 use of A6 records. However, A6 records have been reduced to experimental
3554 status (August 2001) and may die out. So they may never get used at all,
3555 let alone in dnsbl records. However, leave the code here, just in case.
3557 Quite apart from one A6 RR generating multiple addresses, there are DNS
3558 lists that return more than one A record, so we must handle multiple
3559 addresses generated in that way as well. */
3561 if (cb->rc == DNS_SUCCEED)
3564 dns_address **addrp = &(cb->rhs);
3565 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3567 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3569 if (rr->type == T_A)
3571 dns_address *da = dns_address_from_rr(&dnsa, rr);
3575 while (da->next != NULL) da = da->next;
3576 addrp = &(da->next);
3581 /* If we didn't find any A records, change the return code. This can
3582 happen when there is a CNAME record but there are no A records for what
3585 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3588 store_pool = old_pool;
3591 /* Previous lookup was cached */
3595 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3599 /* We now have the result of the DNS lookup, either newly done, or cached
3600 from a previous call. If the lookup succeeded, check against the address
3601 list if there is one. This may be a positive equality list (introduced by
3602 "="), a negative equality list (introduced by "!="), a positive bitmask
3603 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3605 if (cb->rc == DNS_SUCCEED)
3607 dns_address *da = NULL;
3608 uschar *addlist = cb->rhs->address;
3610 /* For A and AAAA records, there may be multiple addresses from multiple
3611 records. For A6 records (currently not expected to be used) there may be
3612 multiple addresses from a single record. */
3614 for (da = cb->rhs->next; da != NULL; da = da->next)
3615 addlist = string_sprintf("%s, %s", addlist, da->address);
3617 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3620 /* Address list check; this can be either for equality, or via a bitmask.
3621 In the latter case, all the bits must match. */
3625 for (da = cb->rhs; da != NULL; da = da->next)
3629 const uschar *ptr = iplist;
3632 /* Handle exact matching */
3636 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3638 if (Ustrcmp(CS da->address, ip) == 0) break;
3642 /* Handle bitmask matching */
3649 /* At present, all known DNS blocking lists use A records, with
3650 IPv4 addresses on the RHS encoding the information they return. I
3651 wonder if this will linger on as the last vestige of IPv4 when IPv6
3652 is ubiquitous? Anyway, for now we use paranoia code to completely
3653 ignore IPv6 addresses. The default mask is 0, which always matches.
3654 We change this only for IPv4 addresses in the list. */
3656 if (host_aton(da->address, address) == 1) mask = address[0];
3658 /* Scan the returned addresses, skipping any that are IPv6 */
3660 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3662 if (host_aton(ip, address) != 1) continue;
3663 if ((address[0] & mask) == address[0]) break;
3669 (a) An IP address in an any ('=') list matched, or
3670 (b) No IP address in an all ('==') list matched
3672 then we're done searching. */
3674 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3677 /* If da == NULL, either
3679 (a) No IP address in an any ('=') list matched, or
3680 (b) An IP address in an all ('==') list didn't match
3682 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3685 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3693 res = US"was no match";
3696 res = US"was an exclude match";
3699 res = US"was an IP address that did not match";
3702 res = US"were no IP addresses that did not match";
3705 debug_printf("=> but we are not accepting this block class because\n");
3706 debug_printf("=> there %s for %s%c%s\n",
3708 ((match_type & MT_ALL) == 0)? "" : "=",
3709 bitmask? '&' : '=', iplist);
3715 /* Either there was no IP list, or the record matched, implying that the
3716 domain is on the list. We now want to find a corresponding TXT record. If an
3717 alternate domain is specified for the TXT record, call this function
3718 recursively to look that up; this has the side effect of re-checking that
3719 there is indeed an A record at the alternate domain. */
3721 if (domain_txt != domain)
3722 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3723 FALSE, match_type, defer_return);
3725 /* If there is no alternate domain, look up a TXT record in the main domain
3726 if it has not previously been cached. */
3730 cb->text_set = TRUE;
3731 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3734 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3736 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3737 if (rr->type == T_TXT) break;
3740 int len = (rr->data)[0];
3741 if (len > 511) len = 127;
3742 store_pool = POOL_PERM;
3743 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3744 store_pool = old_pool;
3749 dnslist_value = addlist;
3750 dnslist_text = cb->text;
3754 /* There was a problem with the DNS lookup */
3756 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3758 log_write(L_dnslist_defer, LOG_MAIN,
3759 "DNS list lookup defer (probably timeout) for %s: %s", query,
3760 (defer_return == OK)? US"assumed in list" :
3761 (defer_return == FAIL)? US"assumed not in list" :
3762 US"returned DEFER");
3763 return defer_return;
3766 /* No entry was found in the DNS; continue for next domain */
3770 debug_printf("DNS lookup for %s failed\n", query);
3771 debug_printf("=> that means %s is not listed at %s\n",
3781 /*************************************************
3782 * Check host against DNS black lists *
3783 *************************************************/
3785 /* This function runs checks against a list of DNS black lists, until one
3786 matches. Each item on the list can be of the form
3788 domain=ip-address/key
3790 The domain is the right-most domain that is used for the query, for example,
3791 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3792 if the DNS lookup returns a matching IP address. Several addresses may be
3793 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3795 If no key is given, what is looked up in the domain is the inverted IP address
3796 of the current client host. If a key is given, it is used to construct the
3797 domain for the lookup. For example:
3799 dsn.rfc-ignorant.org/$sender_address_domain
3801 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3802 then we check for a TXT record for an error message, and if found, save its
3803 value in $dnslist_text. We also cache everything in a tree, to optimize
3806 The TXT record is normally looked up in the same domain as the A record, but
3807 when many lists are combined in a single DNS domain, this will not be a very
3808 specific message. It is possible to specify a different domain for looking up
3809 TXT records; this is given before the main domain, comma-separated. For
3812 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3813 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3815 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3817 Note: an address for testing RBL is 192.203.178.39
3818 Note: an address for testing DUL is 192.203.178.4
3819 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3822 listptr the domain/address/data list
3824 Returns: OK successful lookup (i.e. the address is on the list), or
3825 lookup deferred after +include_unknown
3826 FAIL name not found, or no data found for the given type, or
3827 lookup deferred after +exclude_unknown (default)
3828 DEFER lookup failure, if +defer_unknown was set
3832 verify_check_dnsbl(const uschar **listptr)
3835 int defer_return = FAIL;
3836 const uschar *list = *listptr;
3839 uschar buffer[1024];
3840 uschar revadd[128]; /* Long enough for IPv6 address */
3842 /* Indicate that the inverted IP address is not yet set up */
3846 /* In case this is the first time the DNS resolver is being used. */
3848 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3850 /* Loop through all the domains supplied, until something matches */
3852 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3855 BOOL bitmask = FALSE;
3862 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3864 /* Deal with special values that change the behaviour on defer */
3866 if (domain[0] == '+')
3868 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3869 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3870 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3872 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3877 /* See if there's explicit data to be looked up */
3879 key = Ustrchr(domain, '/');
3880 if (key != NULL) *key++ = 0;
3882 /* See if there's a list of addresses supplied after the domain name. This is
3883 introduced by an = or a & character; if preceded by = we require all matches
3884 and if preceded by ! we invert the result. */
3886 iplist = Ustrchr(domain, '=');
3890 iplist = Ustrchr(domain, '&');
3893 if (iplist != NULL) /* Found either = or & */
3895 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3897 match_type |= MT_NOT;
3901 *iplist++ = 0; /* Terminate domain, move on */
3903 /* If we found = (bitmask == FALSE), check for == or =& */
3905 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3907 bitmask = *iplist++ == '&';
3908 match_type |= MT_ALL;
3912 /* If there is a comma in the domain, it indicates that a second domain for
3913 looking up TXT records is provided, before the main domain. Otherwise we must
3914 set domain_txt == domain. */
3916 domain_txt = domain;
3917 comma = Ustrchr(domain, ',');
3924 /* Check that what we have left is a sensible domain name. There is no reason
3925 why these domains should in fact use the same syntax as hosts and email
3926 domains, but in practice they seem to. However, there is little point in
3927 actually causing an error here, because that would no doubt hold up incoming
3928 mail. Instead, I'll just log it. */
3930 for (s = domain; *s != 0; s++)
3932 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3934 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3935 "strange characters - is this right?", domain);
3940 /* Check the alternate domain if present */
3942 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3944 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3946 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3947 "strange characters - is this right?", domain_txt);
3952 /* If there is no key string, construct the query by adding the domain name
3953 onto the inverted host address, and perform a single DNS lookup. */
3957 if (sender_host_address == NULL) return FAIL; /* can never match */
3958 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3959 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3960 iplist, bitmask, match_type, defer_return);
3963 dnslist_domain = string_copy(domain_txt);
3964 dnslist_matched = string_copy(sender_host_address);
3965 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3966 sender_host_address, dnslist_domain);
3968 if (rc != FAIL) return rc; /* OK or DEFER */
3971 /* If there is a key string, it can be a list of domains or IP addresses to
3972 be concatenated with the main domain. */
3979 uschar keybuffer[256];
3980 uschar keyrevadd[128];
3982 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3983 sizeof(keybuffer))) != NULL)
3985 uschar *prepend = keydomain;
3987 if (string_is_ip_address(keydomain, NULL) != 0)
3989 invert_address(keyrevadd, keydomain);
3990 prepend = keyrevadd;
3993 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3994 bitmask, match_type, defer_return);
3998 dnslist_domain = string_copy(domain_txt);
3999 dnslist_matched = string_copy(keydomain);
4000 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4001 keydomain, dnslist_domain);
4005 /* If the lookup deferred, remember this fact. We keep trying the rest
4006 of the list to see if we get a useful result, and if we don't, we return
4007 DEFER at the end. */
4009 if (rc == DEFER) defer = TRUE;
4010 } /* continue with next keystring domain/address */
4012 if (defer) return DEFER;
4014 } /* continue with next dnsdb outer domain */
4021 /* End of verify.c */