1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
21 /* Structure for caching DNSBL lookups */
23 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
42 static uschar cutthrough_response(char, uschar **);
45 /*************************************************
46 * Retrieve a callout cache record *
47 *************************************************/
49 /* If a record exists, check whether it has expired.
52 dbm_file an open hints file
54 type "address" or "domain"
55 positive_expire expire time for positive records
56 negative_expire expire time for negative records
58 Returns: the cache record if a non-expired one exists, else NULL
61 static dbdata_callout_cache *
62 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
63 int positive_expire, int negative_expire)
68 dbdata_callout_cache *cache_record;
70 cache_record = dbfn_read_with_length(dbm_file, key, &length);
72 if (cache_record == NULL)
74 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
78 /* We treat a record as "negative" if its result field is not positive, or if
79 it is a domain record and the postmaster field is negative. */
81 negative = cache_record->result != ccache_accept ||
82 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
83 expire = negative? negative_expire : positive_expire;
86 if (now - cache_record->time_stamp > expire)
88 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
92 /* If this is a non-reject domain record, check for the obsolete format version
93 that doesn't have the postmaster and random timestamps, by looking at the
94 length. If so, copy it to a new-style block, replicating the record's
95 timestamp. Then check the additional timestamps. (There's no point wasting
96 effort if connections are rejected.) */
98 if (type[0] == 'd' && cache_record->result != ccache_reject)
100 if (length == sizeof(dbdata_callout_cache_obs))
102 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
103 memcpy(new, cache_record, length);
104 new->postmaster_stamp = new->random_stamp = new->time_stamp;
108 if (now - cache_record->postmaster_stamp > expire)
109 cache_record->postmaster_result = ccache_unknown;
111 if (now - cache_record->random_stamp > expire)
112 cache_record->random_result = ccache_unknown;
115 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
121 /*************************************************
122 * Do callout verification for an address *
123 *************************************************/
125 /* This function is called from verify_address() when the address has routed to
126 a host list, and a callout has been requested. Callouts are expensive; that is
127 why a cache is used to improve the efficiency.
130 addr the address that's been routed
131 host_list the list of hosts to try
132 tf the transport feedback block
134 ifstring "interface" option from transport, or NULL
135 portstring "port" option from transport, or NULL
136 protocolstring "protocol" option from transport, or NULL
137 callout the per-command callout timeout
138 callout_overall the overall callout timeout (if < 0 use 4*callout)
139 callout_connect the callout connection timeout (if < 0 use callout)
140 options the verification options - these bits are used:
141 vopt_is_recipient => this is a recipient address
142 vopt_callout_no_cache => don't use callout cache
143 vopt_callout_fullpm => if postmaster check, do full one
144 vopt_callout_random => do the "random" thing
145 vopt_callout_recipsender => use real sender for recipient
146 vopt_callout_recippmaster => use postmaster for recipient
147 se_mailfrom MAIL FROM address for sender verify; NULL => ""
148 pm_mailfrom if non-NULL, do the postmaster check with this sender
150 Returns: OK/FAIL/DEFER
154 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
155 int callout, int callout_overall, int callout_connect, int options,
156 uschar *se_mailfrom, uschar *pm_mailfrom)
158 BOOL is_recipient = (options & vopt_is_recipient) != 0;
159 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
160 BOOL callout_random = (options & vopt_callout_random) != 0;
163 int old_domain_cache_result = ccache_accept;
166 uschar *from_address;
167 uschar *random_local_part = NULL;
168 const uschar *save_deliver_domain = deliver_domain;
169 uschar **failure_ptr = is_recipient?
170 &recipient_verify_failure : &sender_verify_failure;
172 open_db *dbm_file = NULL;
173 dbdata_callout_cache new_domain_record;
174 dbdata_callout_cache_address new_address_record;
176 time_t callout_start_time;
177 uschar peer_offered = 0;
179 new_domain_record.result = ccache_unknown;
180 new_domain_record.postmaster_result = ccache_unknown;
181 new_domain_record.random_result = ccache_unknown;
183 memset(&new_address_record, 0, sizeof(new_address_record));
185 /* For a recipient callout, the key used for the address cache record must
186 include the sender address if we are using the real sender in the callout,
187 because that may influence the result of the callout. */
189 address_key = addr->address;
194 if (options & vopt_callout_recipsender)
196 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
197 from_address = sender_address;
199 else if (options & vopt_callout_recippmaster)
201 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
202 qualify_domain_sender);
203 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
207 /* For a sender callout, we must adjust the key if the mailfrom address is not
212 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
213 if (from_address[0] != 0)
214 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
217 /* Open the callout cache database, it it exists, for reading only at this
218 stage, unless caching has been disabled. */
220 if (callout_no_cache)
222 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
224 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
226 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
229 /* If a cache database is available see if we can avoid the need to do an
230 actual callout by making use of previously-obtained data. */
232 if (dbm_file != NULL)
234 dbdata_callout_cache_address *cache_address_record;
235 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
236 addr->domain, US"domain",
237 callout_cache_domain_positive_expire,
238 callout_cache_domain_negative_expire);
240 /* If an unexpired cache record was found for this domain, see if the callout
241 process can be short-circuited. */
243 if (cache_record != NULL)
245 /* In most cases, if an early command (up to and including MAIL FROM:<>)
246 was rejected, there is no point carrying on. The callout fails. However, if
247 we are doing a recipient verification with use_sender or use_postmaster
248 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
249 will be using a non-empty sender. We have to remember this situation so as
250 not to disturb the cached domain value if this whole verification succeeds
251 (we don't want it turning into "accept"). */
253 old_domain_cache_result = cache_record->result;
255 if (cache_record->result == ccache_reject ||
256 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
258 setflag(addr, af_verify_nsfail);
260 debug_printf("callout cache: domain gave initial rejection, or "
261 "does not accept HELO or MAIL FROM:<>\n");
262 setflag(addr, af_verify_nsfail);
263 addr->user_message = US"(result of an earlier callout reused).";
265 *failure_ptr = US"mail";
269 /* If a previous check on a "random" local part was accepted, we assume
270 that the server does not do any checking on local parts. There is therefore
271 no point in doing the callout, because it will always be successful. If a
272 random check previously failed, arrange not to do it again, but preserve
273 the data in the new record. If a random check is required but hasn't been
274 done, skip the remaining cache processing. */
276 if (callout_random) switch(cache_record->random_result)
280 debug_printf("callout cache: domain accepts random addresses\n");
281 goto END_CALLOUT; /* Default yield is OK */
285 debug_printf("callout cache: domain rejects random addresses\n");
286 callout_random = FALSE;
287 new_domain_record.random_result = ccache_reject;
288 new_domain_record.random_stamp = cache_record->random_stamp;
293 debug_printf("callout cache: need to check random address handling "
294 "(not cached or cache expired)\n");
298 /* If a postmaster check is requested, but there was a previous failure,
299 there is again no point in carrying on. If a postmaster check is required,
300 but has not been done before, we are going to have to do a callout, so skip
301 remaining cache processing. */
303 if (pm_mailfrom != NULL)
305 if (cache_record->postmaster_result == ccache_reject)
307 setflag(addr, af_verify_pmfail);
309 debug_printf("callout cache: domain does not accept "
310 "RCPT TO:<postmaster@domain>\n");
312 *failure_ptr = US"postmaster";
313 setflag(addr, af_verify_pmfail);
314 addr->user_message = US"(result of earlier verification reused).";
317 if (cache_record->postmaster_result == ccache_unknown)
320 debug_printf("callout cache: need to check RCPT "
321 "TO:<postmaster@domain> (not cached or cache expired)\n");
325 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
326 postmaster check if the address itself has to be checked. Also ensure
327 that the value in the cache record is preserved (with its old timestamp).
330 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
331 "TO:<postmaster@domain>\n");
333 new_domain_record.postmaster_result = ccache_accept;
334 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
338 /* We can't give a result based on information about the domain. See if there
339 is an unexpired cache record for this specific address (combined with the
340 sender address if we are doing a recipient callout with a non-empty sender).
343 cache_address_record = (dbdata_callout_cache_address *)
344 get_callout_cache_record(dbm_file,
345 address_key, US"address",
346 callout_cache_positive_expire,
347 callout_cache_negative_expire);
349 if (cache_address_record != NULL)
351 if (cache_address_record->result == ccache_accept)
354 debug_printf("callout cache: address record is positive\n");
359 debug_printf("callout cache: address record is negative\n");
360 addr->user_message = US"Previous (cached) callout verification failure";
361 *failure_ptr = US"recipient";
367 /* Close the cache database while we actually do the callout for real. */
370 dbfn_close(dbm_file);
374 if (!addr->transport)
376 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
378 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
379 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
380 addr->transport->name, addr->transport->driver_name);
383 smtp_transport_options_block *ob =
384 (smtp_transport_options_block *)addr->transport->options_block;
386 /* The information wasn't available in the cache, so we have to do a real
387 callout and save the result in the cache for next time, unless no_cache is set,
388 or unless we have a previously cached negative random result. If we are to test
389 with a random local part, ensure that such a local part is available. If not,
390 log the fact, but carry on without randomming. */
392 if (callout_random && callout_random_local_part != NULL)
393 if (!(random_local_part = expand_string(callout_random_local_part)))
394 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
395 "callout_random_local_part: %s", expand_string_message);
397 /* Default the connect and overall callout timeouts if not set, and record the
398 time we are starting so that we can enforce it. */
400 if (callout_overall < 0) callout_overall = 4 * callout;
401 if (callout_connect < 0) callout_connect = callout;
402 callout_start_time = time(NULL);
404 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
405 output because a callout might take some time. When PIPELINING is active and
406 there are many recipients, the total time for doing lots of callouts can add up
407 and cause the client to time out. So in this case we forgo the PIPELINING
410 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
412 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
413 and we are holding a cutthrough conn open, we can just append the rcpt to
414 that conn for verification purposes (and later delivery also). Simplest
415 coding means skipping this whole loop and doing the append separately.
417 We will need to remember it has been appended so that rcpt-acl tail code
418 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
421 /* Can we re-use an open cutthrough connection? */
422 if ( cutthrough.fd >= 0
423 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
424 == vopt_callout_recipsender
425 && !random_local_part
429 if (addr->transport == cutthrough.addr.transport)
430 for (host = host_list; host; host = host->next)
431 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
434 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
437 deliver_host = host->name;
438 deliver_host_address = host->address;
439 deliver_host_port = host->port;
440 deliver_domain = addr->domain;
441 transport_name = addr->transport->name;
443 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
445 if (!smtp_get_interface(tf->interface, host_af, addr, &interface,
447 !smtp_get_port(tf->port, addr, &port, US"callout"))
448 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
451 if ( ( interface == cutthrough.interface
453 && cutthrough.interface
454 && Ustrcmp(interface, cutthrough.interface) == 0
456 && port == cutthrough.host.port
459 uschar * resp = NULL;
461 /* Match! Send the RCPT TO, append the addr, set done */
463 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
464 transport_rcpt_address(addr,
465 (addr->transport == NULL)? FALSE :
466 addr->transport->rcpt_include_affixes)) >= 0 &&
467 cutthrough_response('2', &resp) == '2';
469 /* This would go horribly wrong if a callout fail was ignored by ACL.
470 We punt by abandoning cutthrough on a reject, like the
475 address_item * na = store_get(sizeof(address_item));
476 *na = cutthrough.addr;
477 cutthrough.addr = *addr;
478 cutthrough.addr.host_used = &cutthrough.host;
479 cutthrough.addr.next = na;
485 cancel_cutthrough_connection("recipient rejected");
486 if (!resp || errno == ETIMEDOUT)
488 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
493 Ustrcpy(resp, US"connection dropped");
496 string_sprintf("response to \"%s\" from %s [%s] was: %s",
497 big_buffer, host->name, host->address,
498 string_printing(resp));
501 string_sprintf("Callout verification failed:\n%s", resp);
503 /* Hard rejection ends the process */
505 if (resp[0] == '5') /* Address rejected */
516 cancel_cutthrough_connection("incompatible connection");
519 /* Now make connections to the hosts and do real callouts. The list of hosts
520 is passed in as an argument. */
522 for (host = host_list; host != NULL && !done; host = host->next)
524 smtp_inblock inblock;
525 smtp_outblock outblock;
528 BOOL send_quit = TRUE;
529 uschar *active_hostname = smtp_active_hostname;
533 BOOL suppress_tls = FALSE;
534 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
535 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
538 dns_answer tlsa_dnsa;
540 uschar inbuffer[4096];
541 uschar outbuffer[1024];
542 uschar responsebuffer[4096];
545 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
546 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
548 /* Skip this host if we don't have an IP address for it. */
550 if (host->address == NULL)
552 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
557 /* Check the overall callout timeout */
559 if (time(NULL) - callout_start_time >= callout_overall)
561 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
565 /* Set IPv4 or IPv6 */
567 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
569 /* Expand and interpret the interface and port strings. The latter will not
570 be used if there is a host-specific port (e.g. from a manualroute router).
571 This has to be delayed till now, because they may expand differently for
572 different hosts. If there's a failure, log it, but carry on with the
575 deliver_host = host->name;
576 deliver_host_address = host->address;
577 deliver_host_port = host->port;
578 deliver_domain = addr->domain;
579 transport_name = addr->transport->name;
581 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
583 || !smtp_get_port(tf->port, addr, &port, US"callout")
585 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
588 /* Set HELO string according to the protocol */
589 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
590 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
593 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
595 /* Set up the buffer for reading SMTP response packets. */
597 inblock.buffer = inbuffer;
598 inblock.buffersize = sizeof(inbuffer);
599 inblock.ptr = inbuffer;
600 inblock.ptrend = inbuffer;
602 /* Set up the buffer for holding SMTP commands while pipelining */
604 outblock.buffer = outbuffer;
605 outblock.buffersize = sizeof(outbuffer);
606 outblock.ptr = outbuffer;
607 outblock.cmd_count = 0;
608 outblock.authenticating = FALSE;
610 /* Connect to the host; on failure, just loop for the next one, but we
611 set the error for the last one. Use the callout_connect timeout. */
613 tls_retry_connection:
615 /* Reset the parameters of a TLS session */
616 tls_out.cipher = tls_out.peerdn = tls_out.peercert = NULL;
618 inblock.sock = outblock.sock =
619 smtp_connect(host, host_af, port, interface, callout_connect,
621 if (inblock.sock < 0)
623 addr->message = string_sprintf("could not connect to %s [%s]: %s",
624 host->name, host->address, strerror(errno));
625 transport_name = NULL;
626 deliver_host = deliver_host_address = NULL;
627 deliver_domain = save_deliver_domain;
631 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
635 tls_out.dane_verified = FALSE;
636 tls_out.tlsa_usage = 0;
639 verify_check_given_host(&ob->hosts_require_dane, host) == OK;
641 if (host->dnssec == DS_YES)
644 || verify_check_given_host(&ob->hosts_try_dane, host) == OK
647 if ((rc = tlsa_lookup(host, &tlsa_dnsa, dane_required)) != OK)
652 else if (dane_required)
654 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
659 ob->tls_tempfail_tryclear = FALSE;
663 /* Expand the helo_data string to find the host name to use. */
665 if (tf->helo_data != NULL)
667 uschar *s = expand_string(tf->helo_data);
669 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
670 "helo_data value for callout: %s", addr->address,
671 expand_string_message);
672 else active_hostname = s;
675 /* Wait for initial response, and send HELO. The smtp_write_command()
676 function leaves its command in big_buffer. This is used in error responses.
677 Initialize it in case the connection is rejected. */
679 Ustrcpy(big_buffer, "initial connection");
681 /* Unless ssl-on-connect, wait for the initial greeting */
685 if (!smtps || (smtps && tls_out.active >= 0))
688 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
689 goto RESPONSE_FAILED;
691 #ifndef DISABLE_EVENT
692 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
693 : host->dnssec==DS_NO ? US"no" : NULL;
694 if (event_raise(addr->transport->event_action,
695 US"smtp:connect", responsebuffer))
697 lookup_dnssec_authenticated = NULL;
698 /* Logging? Debug? */
699 goto RESPONSE_FAILED;
701 lookup_dnssec_authenticated = NULL;
705 /* Not worth checking greeting line for ESMTP support */
706 if (!(esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK))
708 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
713 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
715 peer_offered &= ~PEER_OFFERED_TLS;
716 ob->tls_tempfail_tryclear = FALSE;
718 else /* all other cases */
723 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
724 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
726 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
728 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
731 goto RESPONSE_FAILED;
734 peer_offered &= ~PEER_OFFERED_TLS;
737 goto esmtp_retry; /* fallback to HELO */
740 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
743 ? ehlo_response(responsebuffer, sizeof(responsebuffer),
744 (!suppress_tls && tls_out.active < 0 ? PEER_OFFERED_TLS : 0)
748 | (addr->prop.utf8_msg && !addr->prop.utf8_downcvt
749 ? PEER_OFFERED_UTF8 : 0)
754 /* only care about SIZE if we have size from inbound */
755 | (message_size > 0 && ob->size_addition >= 0
756 ? PEER_OFFERED_SIZE : 0)
761 size_str = peer_offered & PEER_OFFERED_SIZE
762 ? string_sprintf(" SIZE=%d", message_size + ob->size_addition) : US"";
765 tls_offered = !!(peer_offered & PEER_OFFERED_TLS);
768 /* If TLS is available on this connection attempt to
769 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
770 send another EHLO - the server may give a different answer in secure mode. We
771 use a separate buffer for reading the response to STARTTLS so that if it is
772 negative, the original EHLO data is available for subsequent analysis, should
773 the client not be required to use TLS. If the response is bad, copy the buffer
774 for error analysis. */
777 if ( peer_offered & PEER_OFFERED_TLS
778 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK
779 && verify_check_given_host(&ob->hosts_verify_avoid_tls, host) != OK
782 uschar buffer2[4096];
784 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
787 /* If there is an I/O error, transmission of this message is deferred. If
788 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
789 false, we also defer. However, if there is a temporary rejection of STARTTLS
790 and tls_tempfail_tryclear is true, or if there is an outright rejection of
791 STARTTLS, we carry on. This means we will try to send the message in clear,
792 unless the host is in hosts_require_tls (tested below). */
794 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
795 ob->command_timeout))
799 || buffer2[0] == '4' && !ob->tls_tempfail_tryclear
802 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
804 goto RESPONSE_FAILED;
808 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
811 int oldtimeout = ob->command_timeout;
815 ob->command_timeout = callout;
816 rc = tls_client_start(inblock.sock, host, addr, addr->transport
817 # ifdef EXPERIMENTAL_DANE
818 , dane ? &tlsa_dnsa : NULL
821 ob->command_timeout = oldtimeout;
823 /* TLS negotiation failed; give an error. Try in clear on a new
824 connection, if the options permit it for this host. */
829 (void)close(inblock.sock);
830 # ifndef DISABLE_EVENT
831 (void) event_raise(addr->transport->event_action,
832 US"tcp:close", NULL);
834 if ( ob->tls_tempfail_tryclear
836 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
839 log_write(0, LOG_MAIN, "TLS session failure:"
840 " delivering unencrypted to %s [%s] (not in hosts_require_tls)",
841 host->name, host->address);
843 goto tls_retry_connection;
847 /*save_errno = ERRNO_TLSFAILURE;*/
848 /*message = US"failure while setting up TLS session";*/
854 /* TLS session is set up. Copy info for logging. */
855 addr->cipher = tls_out.cipher;
856 addr->peerdn = tls_out.peerdn;
858 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
860 goto smtps_redo_greeting;
862 /* For STARTTLS we need to redo EHLO */
867 /* If the host is required to use a secure channel, ensure that we have one. */
868 if (tls_out.active < 0)
870 # ifdef EXPERIMENTAL_DANE
873 verify_check_given_host(&ob->hosts_require_tls, host) == OK
876 /*save_errno = ERRNO_TLSREQUIRED;*/
877 log_write(0, LOG_MAIN,
878 "H=%s [%s]: a TLS session is required for this host, but %s",
879 host->name, host->address,
880 peer_offered & PEER_OFFERED_TLS
881 ? "an attempt to start TLS failed"
882 : "the server did not offer TLS support");
887 #endif /*SUPPORT_TLS*/
889 done = TRUE; /* so far so good; have response to HELO */
891 /* For now, transport_filter by cutthrough-delivery is not supported */
892 /* Need proper integration with the proper transport mechanism. */
893 if (cutthrough.delivery)
895 if (addr->transport->filter_command)
897 cutthrough.delivery = FALSE;
898 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
903 cutthrough.delivery = FALSE;
904 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
913 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
915 /* Failure to accept HELO is cached; this blocks the whole domain for all
916 senders. I/O errors and defer responses are not cached. */
920 *failure_ptr = US"mail"; /* At or before MAIL */
921 if (errno == 0 && responsebuffer[0] == '5')
923 setflag(addr, af_verify_nsfail);
924 new_domain_record.result = ccache_reject;
929 else if ( addr->prop.utf8_msg
930 && !addr->prop.utf8_downcvt
931 && !(peer_offered & PEER_OFFERED_UTF8)
934 HDEBUG(D_acl|D_v) debug_printf("utf8 required but not offered\n");
935 errno = ERRNO_UTF8_FWD;
936 setflag(addr, af_verify_nsfail);
939 else if ( addr->prop.utf8_msg
940 && (addr->prop.utf8_downcvt || !(peer_offered & PEER_OFFERED_UTF8))
941 && (setflag(addr, af_utf8_downcvt),
942 from_address = string_address_utf8_to_alabel(from_address,
947 errno = ERRNO_EXPANDFAIL;
948 setflag(addr, af_verify_nsfail);
953 /* If we haven't authenticated, but are required to, give up. */
956 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
957 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
959 /* Copy AUTH info for logging */
960 ( (addr->authenticator = client_authenticator),
961 (addr->auth_id = client_authenticated_id),
963 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
964 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
967 ( (addr->auth_sndr = client_authenticated_sender),
969 /* Send the MAIL command */
970 (smtp_write_command(&outblock, FALSE,
972 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
973 ? "MAIL FROM:<%s>%s%s SMTPUTF8\r\n"
976 "MAIL FROM:<%s>%s%s\r\n",
977 from_address, responsebuffer, size_str) >= 0)
980 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
983 deliver_host = deliver_host_address = NULL;
984 deliver_domain = save_deliver_domain;
986 /* If the host does not accept MAIL FROM:<>, arrange to cache this
987 information, but again, don't record anything for an I/O error or a defer. Do
988 not cache rejections of MAIL when a non-empty sender has been used, because
989 that blocks the whole domain for all senders. */
993 *failure_ptr = US"mail"; /* At or before MAIL */
994 if (errno == 0 && responsebuffer[0] == '5')
996 setflag(addr, af_verify_nsfail);
997 if (from_address[0] == 0)
998 new_domain_record.result = ccache_reject_mfnull;
1002 /* Otherwise, proceed to check a "random" address (if required), then the
1003 given address, and the postmaster address (if required). Between each check,
1004 issue RSET, because some servers accept only one recipient after MAIL
1007 Before doing this, set the result in the domain cache record to "accept",
1008 unless its previous value was ccache_reject_mfnull. In that case, the domain
1009 rejects MAIL FROM:<> and we want to continue to remember that. When that is
1010 the case, we have got here only in the case of a recipient verification with
1011 a non-null sender. */
1015 const uschar * rcpt_domain = addr->domain;
1018 uschar * errstr = NULL;
1019 if ( testflag(addr, af_utf8_downcvt)
1020 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
1024 addr->message = errstr;
1025 errno = ERRNO_EXPANDFAIL;
1026 setflag(addr, af_verify_nsfail);
1028 rcpt_domain = US""; /*XXX errorhandling! */
1032 new_domain_record.result =
1033 (old_domain_cache_result == ccache_reject_mfnull)?
1034 ccache_reject_mfnull: ccache_accept;
1036 /* Do the random local part check first */
1038 if (random_local_part != NULL)
1040 uschar randombuffer[1024];
1042 smtp_write_command(&outblock, FALSE,
1043 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
1044 rcpt_domain) >= 0 &&
1045 smtp_read_response(&inblock, randombuffer,
1046 sizeof(randombuffer), '2', callout);
1048 /* Remember when we last did a random test */
1050 new_domain_record.random_stamp = time(NULL);
1052 /* If accepted, we aren't going to do any further tests below. */
1055 new_domain_record.random_result = ccache_accept;
1057 /* Otherwise, cache a real negative response, and get back to the right
1058 state to send RCPT. Unless there's some problem such as a dropped
1059 connection, we expect to succeed, because the commands succeeded above.
1060 However, some servers drop the connection after responding to an
1061 invalid recipient, so on (any) error we drop and remake the connection.
1064 else if (errno == 0)
1066 /* This would be ok for 1st rcpt a cutthrough, but no way to
1067 handle a subsequent. So refuse to support any */
1068 cancel_cutthrough_connection("random-recipient");
1070 if (randombuffer[0] == '5')
1071 new_domain_record.random_result = ccache_reject;
1074 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1075 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1078 smtp_write_command(&outblock, FALSE,
1080 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
1081 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
1084 "MAIL FROM:<%s>\r\n",
1085 from_address) >= 0 &&
1086 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1092 debug_printf("problem after random/rset/mfrom; reopen conn\n");
1093 random_local_part = NULL;
1095 tls_close(FALSE, TRUE);
1097 (void)close(inblock.sock);
1098 #ifndef DISABLE_EVENT
1099 (void) event_raise(addr->transport->event_action,
1100 US"tcp:close", NULL);
1102 goto tls_retry_connection;
1105 else done = FALSE; /* Some timeout/connection problem */
1106 } /* Random check */
1108 /* If the host is accepting all local parts, as determined by the "random"
1109 check, we don't need to waste time doing any further checking. */
1111 if (new_domain_record.random_result != ccache_accept && done)
1113 /* Get the rcpt_include_affixes flag from the transport if there is one,
1114 but assume FALSE if there is not. */
1116 uschar * rcpt = transport_rcpt_address(addr,
1117 addr->transport ? addr->transport->rcpt_include_affixes : FALSE);
1120 /*XXX should the conversion be moved into transport_rcpt_address() ? */
1121 uschar * dummy_errstr = NULL;
1122 if ( testflag(addr, af_utf8_downcvt)
1123 && (rcpt = string_address_utf8_to_alabel(rcpt, &dummy_errstr),
1127 errno = ERRNO_EXPANDFAIL;
1128 *failure_ptr = US"recipient";
1135 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
1137 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1141 new_address_record.result = ccache_accept;
1142 else if (errno == 0 && responsebuffer[0] == '5')
1144 *failure_ptr = US"recipient";
1145 new_address_record.result = ccache_reject;
1148 /* Do postmaster check if requested; if a full check is required, we
1149 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
1151 if (done && pm_mailfrom != NULL)
1153 /* Could possibly shift before main verify, just above, and be ok
1154 for cutthrough. But no way to handle a subsequent rcpt, so just
1156 cancel_cutthrough_connection("postmaster verify");
1157 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
1160 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1161 smtp_read_response(&inblock, responsebuffer,
1162 sizeof(responsebuffer), '2', callout) &&
1164 smtp_write_command(&outblock, FALSE,
1165 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
1166 smtp_read_response(&inblock, responsebuffer,
1167 sizeof(responsebuffer), '2', callout) &&
1169 /* First try using the current domain */
1172 smtp_write_command(&outblock, FALSE,
1173 "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 &&
1174 smtp_read_response(&inblock, responsebuffer,
1175 sizeof(responsebuffer), '2', callout)
1180 /* If that doesn't work, and a full check is requested,
1181 try without the domain. */
1184 (options & vopt_callout_fullpm) != 0 &&
1185 smtp_write_command(&outblock, FALSE,
1186 "RCPT TO:<postmaster>\r\n") >= 0 &&
1187 smtp_read_response(&inblock, responsebuffer,
1188 sizeof(responsebuffer), '2', callout)
1191 /* Sort out the cache record */
1193 new_domain_record.postmaster_stamp = time(NULL);
1196 new_domain_record.postmaster_result = ccache_accept;
1197 else if (errno == 0 && responsebuffer[0] == '5')
1199 *failure_ptr = US"postmaster";
1200 setflag(addr, af_verify_pmfail);
1201 new_domain_record.postmaster_result = ccache_reject;
1204 } /* Random not accepted */
1205 } /* MAIL FROM: accepted */
1207 /* For any failure of the main check, other than a negative response, we just
1208 close the connection and carry on. We can identify a negative response by the
1209 fact that errno is zero. For I/O errors it will be non-zero
1211 Set up different error texts for logging and for sending back to the caller
1212 as an SMTP response. Log in all cases, using a one-line format. For sender
1213 callouts, give a full response to the caller, but for recipient callouts,
1214 don't give the IP address because this may be an internal host whose identity
1215 is not to be widely broadcast. */
1219 if (errno == ETIMEDOUT)
1221 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1225 else if (errno == ERRNO_UTF8_FWD)
1227 extern int acl_where; /* src/acl.c */
1229 addr->message = string_sprintf(
1230 "response to \"%s\" from %s [%s] did not include SMTPUTF8",
1231 big_buffer, host->name, host->address);
1232 addr->user_message = acl_where == ACL_WHERE_RCPT
1233 ? US"533 mailbox name not allowed"
1234 : US"550 mailbox unavailable";
1239 else if (errno == 0)
1241 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1244 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1245 big_buffer, host->name, host->address,
1246 string_printing(responsebuffer));
1248 addr->user_message = is_recipient?
1249 string_sprintf("Callout verification failed:\n%s", responsebuffer)
1251 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1252 host->address, big_buffer, responsebuffer);
1254 /* Hard rejection ends the process */
1256 if (responsebuffer[0] == '5') /* Address rejected */
1264 /* End the SMTP conversation and close the connection. */
1266 /* Cutthrough - on a successfull connect and recipient-verify with
1267 use-sender and we are 1st rcpt and have no cutthrough conn so far
1268 here is where we want to leave the conn open */
1269 if ( cutthrough.delivery
1273 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
1274 && !random_local_part
1276 && cutthrough.fd < 0
1280 cutthrough.fd = outblock.sock; /* We assume no buffer in use in the outblock */
1281 cutthrough.nrcpt = 1;
1282 cutthrough.interface = interface;
1283 cutthrough.host = *host;
1284 cutthrough.addr = *addr; /* Save the address_item for later logging */
1285 cutthrough.addr.next = NULL;
1286 cutthrough.addr.host_used = &cutthrough.host;
1288 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1290 ctblock.buffer = ctbuffer;
1291 ctblock.buffersize = sizeof(ctbuffer);
1292 ctblock.ptr = ctbuffer;
1293 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1294 ctblock.sock = cutthrough.fd;
1298 /* Ensure no cutthrough on multiple address verifies */
1299 if (options & vopt_callout_recipsender)
1300 cancel_cutthrough_connection("multiple verify calls");
1301 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1304 tls_close(FALSE, TRUE);
1306 (void)close(inblock.sock);
1307 #ifndef DISABLE_EVENT
1308 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1312 } /* Loop through all hosts, while !done */
1315 /* If we get here with done == TRUE, a successful callout happened, and yield
1316 will be set OK or FAIL according to the response to the RCPT command.
1317 Otherwise, we looped through the hosts but couldn't complete the business.
1318 However, there may be domain-specific information to cache in both cases.
1320 The value of the result field in the new_domain record is ccache_unknown if
1321 there was an error before or with MAIL FROM:, and errno was not zero,
1322 implying some kind of I/O error. We don't want to write the cache in that case.
1323 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1325 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1327 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1330 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1334 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1335 (int)sizeof(dbdata_callout_cache));
1336 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1337 " result=%d postmaster=%d random=%d\n",
1338 new_domain_record.result,
1339 new_domain_record.postmaster_result,
1340 new_domain_record.random_result);
1344 /* If a definite result was obtained for the callout, cache it unless caching
1349 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1351 if (dbm_file == NULL)
1352 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1353 if (dbm_file == NULL)
1355 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1359 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1360 (int)sizeof(dbdata_callout_cache_address));
1361 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1362 (new_address_record.result == ccache_accept)? "positive" : "negative");
1367 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1368 temporary error. If there was only one host, and a response was received, leave
1369 it alone if supplying details. Otherwise, give a generic response. */
1373 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1374 is_recipient? "recipient" : "sender");
1377 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1379 addr->user_message = (!smtp_return_error_details)? dullmsg :
1380 string_sprintf("%s for <%s>.\n"
1381 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1382 "they may be permanently unreachable from this server. In the latter case,\n%s",
1383 dullmsg, addr->address,
1385 "the address will never be accepted."
1387 "you need to change the address or create an MX record for its domain\n"
1388 "if it is supposed to be generally accessible from the Internet.\n"
1389 "Talk to your mail administrator for details.");
1391 /* Force a specific error code */
1393 addr->basic_errno = ERRNO_CALLOUTDEFER;
1396 /* Come here from within the cache-reading code on fast-track exit. */
1399 if (dbm_file != NULL) dbfn_close(dbm_file);
1405 /* Called after recipient-acl to get a cutthrough connection open when
1406 one was requested and a recipient-verify wasn't subsequently done.
1409 open_cutthrough_connection( address_item * addr )
1414 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1415 /* We must use a copy of the address for verification, because it might
1419 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1420 rcpt_count > 1 ? "more" : "start");
1421 rc= verify_address(&addr2, NULL,
1422 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1423 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1425 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1431 /* Send given number of bytes from the buffer */
1433 cutthrough_send(int n)
1435 if(cutthrough.fd < 0)
1440 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1442 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1445 transport_count += n;
1446 ctblock.ptr= ctblock.buffer;
1450 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1457 _cutthrough_puts(uschar * cp, int n)
1461 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1462 if(!cutthrough_send(ctblock.buffersize))
1465 *ctblock.ptr++ = *cp++;
1470 /* Buffered output of counted data block. Return boolean success */
1472 cutthrough_puts(uschar * cp, int n)
1474 if (cutthrough.fd < 0) return TRUE;
1475 if (_cutthrough_puts(cp, n)) return TRUE;
1476 cancel_cutthrough_connection("transmit failed");
1482 _cutthrough_flush_send(void)
1484 int n= ctblock.ptr-ctblock.buffer;
1487 if(!cutthrough_send(n))
1493 /* Send out any bufferred output. Return boolean success. */
1495 cutthrough_flush_send(void)
1497 if (_cutthrough_flush_send()) return TRUE;
1498 cancel_cutthrough_connection("transmit failed");
1504 cutthrough_put_nl(void)
1506 return cutthrough_puts(US"\r\n", 2);
1510 /* Get and check response from cutthrough target */
1512 cutthrough_response(char expect, uschar ** copy)
1514 smtp_inblock inblock;
1515 uschar inbuffer[4096];
1516 uschar responsebuffer[4096];
1518 inblock.buffer = inbuffer;
1519 inblock.buffersize = sizeof(inbuffer);
1520 inblock.ptr = inbuffer;
1521 inblock.ptrend = inbuffer;
1522 inblock.sock = cutthrough.fd;
1523 /* this relies on (inblock.sock == tls_out.active) */
1524 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1525 cancel_cutthrough_connection("target timeout on read");
1530 *copy = cp = string_copy(responsebuffer);
1531 /* Trim the trailing end of line */
1532 cp += Ustrlen(responsebuffer);
1533 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1534 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1537 return responsebuffer[0];
1541 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1543 cutthrough_predata(void)
1545 if(cutthrough.fd < 0)
1548 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1549 cutthrough_puts(US"DATA\r\n", 6);
1550 cutthrough_flush_send();
1552 /* Assume nothing buffered. If it was it gets ignored. */
1553 return cutthrough_response('3', NULL) == '3';
1557 /* fd and use_crlf args only to match write_chunk() */
1559 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1562 while(s && (s2 = Ustrchr(s, '\n')))
1564 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1572 /* Buffered send of headers. Return success boolean. */
1573 /* Expands newlines to wire format (CR,NL). */
1574 /* Also sends header-terminating blank line. */
1576 cutthrough_headers_send(void)
1578 if(cutthrough.fd < 0)
1581 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1582 but having a separate buffered-output function (for now)
1584 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1586 if (!transport_headers_send(&cutthrough.addr, cutthrough.fd,
1587 cutthrough.addr.transport->add_headers,
1588 cutthrough.addr.transport->remove_headers,
1589 &cutthrough_write_chunk, TRUE,
1590 cutthrough.addr.transport->rewrite_rules,
1591 cutthrough.addr.transport->rewrite_existflags))
1594 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1600 close_cutthrough_connection(const char * why)
1602 if(cutthrough.fd >= 0)
1604 /* We could be sending this after a bunch of data, but that is ok as
1605 the only way to cancel the transfer in dataphase is to drop the tcp
1606 conn before the final dot.
1608 ctblock.ptr = ctbuffer;
1609 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1610 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1611 _cutthrough_flush_send();
1612 /* No wait for response */
1615 tls_close(FALSE, TRUE);
1617 (void)close(cutthrough.fd);
1619 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1621 ctblock.ptr = ctbuffer;
1625 cancel_cutthrough_connection(const char * why)
1627 close_cutthrough_connection(why);
1628 cutthrough.delivery = FALSE;
1634 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1635 Log an OK response as a transmission.
1636 Close the connection.
1637 Return smtp response-class digit.
1640 cutthrough_finaldot(void)
1643 address_item * addr;
1644 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1646 /* Assume data finshed with new-line */
1647 if( !cutthrough_puts(US".", 1)
1648 || !cutthrough_put_nl()
1649 || !cutthrough_flush_send()
1651 return cutthrough.addr.message;
1653 res = cutthrough_response('2', &cutthrough.addr.message);
1654 for (addr = &cutthrough.addr; addr; addr = addr->next)
1656 addr->message = cutthrough.addr.message;
1660 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1661 close_cutthrough_connection("delivered");
1665 delivery_log(LOG_MAIN, addr, 0,
1666 US"tmp-reject from cutthrough after DATA:");
1670 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1671 US"rejected after DATA:");
1678 return cutthrough.addr.message;
1683 /*************************************************
1684 * Copy error to toplevel address *
1685 *************************************************/
1687 /* This function is used when a verify fails or defers, to ensure that the
1688 failure or defer information is in the original toplevel address. This applies
1689 when an address is redirected to a single new address, and the failure or
1690 deferral happens to the child address.
1693 vaddr the verify address item
1694 addr the final address item
1697 Returns: the value of YIELD
1701 copy_error(address_item *vaddr, address_item *addr, int yield)
1705 vaddr->message = addr->message;
1706 vaddr->user_message = addr->user_message;
1707 vaddr->basic_errno = addr->basic_errno;
1708 vaddr->more_errno = addr->more_errno;
1709 vaddr->prop.address_data = addr->prop.address_data;
1710 copyflag(vaddr, addr, af_pass_message);
1718 /**************************************************
1719 * printf that automatically handles TLS if needed *
1720 ***************************************************/
1722 /* This function is used by verify_address() as a substitute for all fprintf()
1723 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1724 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1725 that assumes that we always use the smtp_out FILE* when not using TLS or the
1726 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1727 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1731 f the candidate FILE* to write to
1732 format format string
1733 ... optional arguments
1739 static void PRINTF_FUNCTION(2,3)
1740 respond_printf(FILE *f, const char *format, ...)
1744 va_start(ap, format);
1745 if (smtp_out && (f == smtp_out))
1746 smtp_vprintf(format, ap);
1748 vfprintf(f, format, ap);
1754 /*************************************************
1755 * Verify an email address *
1756 *************************************************/
1758 /* This function is used both for verification (-bv and at other times) and
1759 address testing (-bt), which is indicated by address_test_mode being set.
1762 vaddr contains the address to verify; the next field in this block
1764 f if not NULL, write the result to this file
1765 options various option bits:
1766 vopt_fake_sender => this sender verify is not for the real
1767 sender (it was verify=sender=xxxx or an address from a
1768 header line) - rewriting must not change sender_address
1769 vopt_is_recipient => this is a recipient address, otherwise
1770 it's a sender address - this affects qualification and
1771 rewriting and messages from callouts
1772 vopt_qualify => qualify an unqualified address; else error
1773 vopt_expn => called from SMTP EXPN command
1774 vopt_success_on_redirect => when a new address is generated
1775 the verification instantly succeeds
1777 These ones are used by do_callout() -- the options variable
1780 vopt_callout_fullpm => if postmaster check, do full one
1781 vopt_callout_no_cache => don't use callout cache
1782 vopt_callout_random => do the "random" thing
1783 vopt_callout_recipsender => use real sender for recipient
1784 vopt_callout_recippmaster => use postmaster for recipient
1786 callout if > 0, specifies that callout is required, and gives timeout
1787 for individual commands
1788 callout_overall if > 0, gives overall timeout for the callout function;
1789 if < 0, a default is used (see do_callout())
1790 callout_connect the connection timeout for callouts
1791 se_mailfrom when callout is requested to verify a sender, use this
1792 in MAIL FROM; NULL => ""
1793 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1794 thing and use this as the sender address (may be "")
1796 routed if not NULL, set TRUE if routing succeeded, so we can
1797 distinguish between routing failed and callout failed
1799 Returns: OK address verified
1800 FAIL address failed to verify
1801 DEFER can't tell at present
1805 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1806 int callout_overall, int callout_connect, uschar *se_mailfrom,
1807 uschar *pm_mailfrom, BOOL *routed)
1810 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1811 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1812 BOOL expn = (options & vopt_expn) != 0;
1813 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1816 int verify_type = expn? v_expn :
1817 address_test_mode? v_none :
1818 is_recipient? v_recipient : v_sender;
1819 address_item *addr_list;
1820 address_item *addr_new = NULL;
1821 address_item *addr_remote = NULL;
1822 address_item *addr_local = NULL;
1823 address_item *addr_succeed = NULL;
1824 uschar **failure_ptr = is_recipient?
1825 &recipient_verify_failure : &sender_verify_failure;
1826 uschar *ko_prefix, *cr;
1827 uschar *address = vaddr->address;
1828 uschar *save_sender;
1829 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1831 /* Clear, just in case */
1833 *failure_ptr = NULL;
1835 /* Set up a prefix and suffix for error message which allow us to use the same
1836 output statements both in EXPN mode (where an SMTP response is needed) and when
1837 debugging with an output file. */
1841 ko_prefix = US"553 ";
1844 else ko_prefix = cr = US"";
1846 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1848 if (parse_find_at(address) == NULL)
1850 if ((options & vopt_qualify) == 0)
1853 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1854 ko_prefix, address, cr);
1855 *failure_ptr = US"qualify";
1858 address = rewrite_address_qualify(address, is_recipient);
1863 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1864 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1867 /* Rewrite and report on it. Clear the domain and local part caches - these
1868 may have been set by domains and local part tests during an ACL. */
1870 if (global_rewrite_rules != NULL)
1872 uschar *old = address;
1873 address = rewrite_address(address, is_recipient, FALSE,
1874 global_rewrite_rules, rewrite_existflags);
1877 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1878 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1879 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1883 /* If this is the real sender address, we must update sender_address at
1884 this point, because it may be referred to in the routers. */
1886 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1887 sender_address = address;
1889 /* If the address was rewritten to <> no verification can be done, and we have
1890 to return OK. This rewriting is permitted only for sender addresses; for other
1891 addresses, such rewriting fails. */
1893 if (address[0] == 0) return OK;
1895 /* Flip the legacy TLS-related variables over to the outbound set in case
1896 they're used in the context of a transport used by verification. Reset them
1897 at exit from this routine. */
1899 tls_modify_variables(&tls_out);
1901 /* Save a copy of the sender address for re-instating if we change it to <>
1902 while verifying a sender address (a nice bit of self-reference there). */
1904 save_sender = sender_address;
1906 /* Update the address structure with the possibly qualified and rewritten
1907 address. Set it up as the starting address on the chain of new addresses. */
1909 vaddr->address = address;
1912 /* We need a loop, because an address can generate new addresses. We must also
1913 cope with generated pipes and files at the top level. (See also the code and
1914 comment in deliver.c.) However, it is usually the case that the router for
1915 user's .forward files has its verify flag turned off.
1917 If an address generates more than one child, the loop is used only when
1918 full_info is set, and this can only be set locally. Remote enquiries just get
1919 information about the top level address, not anything that it generated. */
1921 while (addr_new != NULL)
1924 address_item *addr = addr_new;
1926 addr_new = addr->next;
1931 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1932 debug_printf("Considering %s\n", addr->address);
1935 /* Handle generated pipe, file or reply addresses. We don't get these
1936 when handling EXPN, as it does only one level of expansion. */
1938 if (testflag(addr, af_pfr))
1945 if (addr->address[0] == '>')
1947 allow = testflag(addr, af_allow_reply);
1948 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1952 allow = (addr->address[0] == '|')?
1953 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1954 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1957 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1958 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1959 "%s\n", addr->message);
1961 fprintf(f, "\n transport = %s\n", addr->transport->name);
1963 fprintf(f, " *** forbidden ***\n");
1968 /* Just in case some router parameter refers to it. */
1970 return_path = (addr->prop.errors_address != NULL)?
1971 addr->prop.errors_address : sender_address;
1973 /* Split the address into domain and local part, handling the %-hack if
1974 necessary, and then route it. While routing a sender address, set
1975 $sender_address to <> because that is what it will be if we were trying to
1976 send a bounce to the sender. */
1978 if (routed != NULL) *routed = FALSE;
1979 if ((rc = deliver_split_address(addr)) == OK)
1981 if (!is_recipient) sender_address = null_sender;
1982 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1983 &addr_succeed, verify_type);
1984 sender_address = save_sender; /* Put back the real sender */
1987 /* If routing an address succeeded, set the flag that remembers, for use when
1988 an ACL cached a sender verify (in case a callout fails). Then if routing set
1989 up a list of hosts or the transport has a host list, and the callout option
1990 is set, and we aren't in a host checking run, do the callout verification,
1991 and set another flag that notes that a callout happened. */
1995 if (routed != NULL) *routed = TRUE;
1998 host_item *host_list = addr->host_list;
1999 transport_instance * tp;
2001 /* Make up some data for use in the case where there is no remote
2004 transport_feedback tf = {
2005 NULL, /* interface (=> any) */
2006 US"smtp", /* port */
2007 US"smtp", /* protocol */
2009 US"$smtp_active_hostname", /* helo_data */
2010 FALSE, /* hosts_override */
2011 FALSE, /* hosts_randomize */
2012 FALSE, /* gethostbyname */
2013 TRUE, /* qualify_single */
2014 FALSE /* search_parents */
2017 /* If verification yielded a remote transport, we want to use that
2018 transport's options, so as to mimic what would happen if we were really
2019 sending a message to this address. */
2021 if ((tp = addr->transport) && !tp->info->local)
2023 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
2025 /* If the transport has hosts and the router does not, or if the
2026 transport is configured to override the router's hosts, we must build a
2027 host list of the transport's hosts, and find the IP addresses */
2029 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
2032 const uschar *save_deliver_domain = deliver_domain;
2033 uschar *save_deliver_localpart = deliver_localpart;
2035 host_list = NULL; /* Ignore the router's hosts */
2037 deliver_domain = addr->domain;
2038 deliver_localpart = addr->local_part;
2039 s = expand_string(tf.hosts);
2040 deliver_domain = save_deliver_domain;
2041 deliver_localpart = save_deliver_localpart;
2045 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
2046 "\"%s\" in %s transport for callout: %s", tf.hosts,
2047 tp->name, expand_string_message);
2052 host_item *host, *nexthost;
2053 host_build_hostlist(&host_list, s, tf.hosts_randomize);
2055 /* Just ignore failures to find a host address. If we don't manage
2056 to find any addresses, the callout will defer. Note that more than
2057 one address may be found for a single host, which will result in
2058 additional host items being inserted into the chain. Hence we must
2059 save the next host first. */
2061 flags = HOST_FIND_BY_A;
2062 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2063 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2065 for (host = host_list; host != NULL; host = nexthost)
2067 nexthost = host->next;
2068 if (tf.gethostbyname ||
2069 string_is_ip_address(host->name, NULL) != 0)
2070 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
2073 dnssec_domains * dnssec_domains = NULL;
2074 if (Ustrcmp(tp->driver_name, "smtp") == 0)
2076 smtp_transport_options_block * ob =
2077 (smtp_transport_options_block *) tp->options_block;
2078 dnssec_domains = &ob->dnssec;
2081 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2082 dnssec_domains, NULL, NULL);
2089 /* Can only do a callout if we have at least one host! If the callout
2090 fails, it will have set ${sender,recipient}_verify_failure. */
2092 if (host_list != NULL)
2094 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
2095 if (host_checking && !host_checking_callout)
2098 debug_printf("... callout omitted by default when host testing\n"
2099 "(Use -bhc if you want the callouts to happen.)\n");
2104 deliver_set_expansions(addr);
2106 verify_mode = is_recipient ? US"R" : US"S";
2107 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
2108 callout_connect, options, se_mailfrom, pm_mailfrom);
2114 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
2115 "transport provided a host list\n");
2120 /* Otherwise, any failure is a routing failure */
2122 else *failure_ptr = US"route";
2124 /* A router may return REROUTED if it has set up a child address as a result
2125 of a change of domain name (typically from widening). In this case we always
2126 want to continue to verify the new child. */
2128 if (rc == REROUTED) continue;
2130 /* Handle hard failures */
2137 address_item *p = addr->parent;
2139 respond_printf(f, "%s%s %s", ko_prefix,
2140 full_info? addr->address : address,
2141 address_test_mode? "is undeliverable" : "failed to verify");
2142 if (!expn && admin_user)
2144 if (addr->basic_errno > 0)
2145 respond_printf(f, ": %s", strerror(addr->basic_errno));
2146 if (addr->message != NULL)
2147 respond_printf(f, ": %s", addr->message);
2150 /* Show parents iff doing full info */
2152 if (full_info) while (p != NULL)
2154 respond_printf(f, "%s\n <-- %s", cr, p->address);
2157 respond_printf(f, "%s\n", cr);
2159 cancel_cutthrough_connection("routing hard fail");
2163 yield = copy_error(vaddr, addr, FAIL);
2171 else if (rc == DEFER)
2176 address_item *p = addr->parent;
2177 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
2178 full_info? addr->address : address);
2179 if (!expn && admin_user)
2181 if (addr->basic_errno > 0)
2182 respond_printf(f, ": %s", strerror(addr->basic_errno));
2183 if (addr->message != NULL)
2184 respond_printf(f, ": %s", addr->message);
2185 else if (addr->basic_errno <= 0)
2186 respond_printf(f, ": unknown error");
2189 /* Show parents iff doing full info */
2191 if (full_info) while (p != NULL)
2193 respond_printf(f, "%s\n <-- %s", cr, p->address);
2196 respond_printf(f, "%s\n", cr);
2198 cancel_cutthrough_connection("routing soft fail");
2202 yield = copy_error(vaddr, addr, DEFER);
2205 else if (yield == OK) yield = DEFER;
2208 /* If we are handling EXPN, we do not want to continue to route beyond
2209 the top level (whose address is in "address"). */
2213 uschar *ok_prefix = US"250-";
2214 if (addr_new == NULL)
2216 if (addr_local == NULL && addr_remote == NULL)
2217 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2219 respond_printf(f, "250 <%s>\r\n", address);
2221 else while (addr_new != NULL)
2223 address_item *addr2 = addr_new;
2224 addr_new = addr2->next;
2225 if (addr_new == NULL) ok_prefix = US"250 ";
2226 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2232 /* Successful routing other than EXPN. */
2236 /* Handle successful routing when short info wanted. Otherwise continue for
2237 other (generated) addresses. Short info is the operational case. Full info
2238 can be requested only when debug_selector != 0 and a file is supplied.
2240 There is a conflict between the use of aliasing as an alternate email
2241 address, and as a sort of mailing list. If an alias turns the incoming
2242 address into just one address (e.g. J.Caesar->jc44) you may well want to
2243 carry on verifying the generated address to ensure it is valid when
2244 checking incoming mail. If aliasing generates multiple addresses, you
2245 probably don't want to do this. Exim therefore treats the generation of
2246 just a single new address as a special case, and continues on to verify the
2247 generated address. */
2249 if (!full_info && /* Stop if short info wanted AND */
2250 (((addr_new == NULL || /* No new address OR */
2251 addr_new->next != NULL || /* More than one new address OR */
2252 testflag(addr_new, af_pfr))) /* New address is pfr */
2254 (addr_new != NULL && /* At least one new address AND */
2255 success_on_redirect))) /* success_on_redirect is set */
2257 if (f != NULL) fprintf(f, "%s %s\n", address,
2258 address_test_mode? "is deliverable" : "verified");
2260 /* If we have carried on to verify a child address, we want the value
2261 of $address_data to be that of the child */
2263 vaddr->prop.address_data = addr->prop.address_data;
2268 } /* Loop for generated addresses */
2270 /* Display the full results of the successful routing, including any generated
2271 addresses. Control gets here only when full_info is set, which requires f not
2272 to be NULL, and this occurs only when a top-level verify is called with the
2273 debugging switch on.
2275 If there are no local and no remote addresses, and there were no pipes, files,
2276 or autoreplies, and there were no errors or deferments, the message is to be
2277 discarded, usually because of the use of :blackhole: in an alias file. */
2279 if (allok && addr_local == NULL && addr_remote == NULL)
2281 fprintf(f, "mail to %s is discarded\n", address);
2285 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2288 address_item *addr = addr_list;
2289 address_item *p = addr->parent;
2290 transport_instance * tp = addr->transport;
2292 addr_list = addr->next;
2294 fprintf(f, "%s", CS addr->address);
2295 #ifdef EXPERIMENTAL_SRS
2296 if(addr->prop.srs_sender)
2297 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2300 /* If the address is a duplicate, show something about it. */
2302 if (!testflag(addr, af_pfr))
2305 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2306 fprintf(f, " [duplicate, would not be delivered]");
2307 else tree_add_duplicate(addr->unique, addr);
2310 /* Now show its parents */
2312 for (p = addr->parent; p; p = p->parent)
2313 fprintf(f, "\n <-- %s", p->address);
2316 /* Show router, and transport */
2318 fprintf(f, "router = %s, transport = %s\n",
2319 addr->router->name, tp ? tp->name : US"unset");
2321 /* Show any hosts that are set up by a router unless the transport
2322 is going to override them; fiddle a bit to get a nice format. */
2324 if (addr->host_list && tp && !tp->overrides_hosts)
2329 for (h = addr->host_list; h; h = h->next)
2330 { /* get max lengths of host names, addrs */
2331 int len = Ustrlen(h->name);
2332 if (len > maxlen) maxlen = len;
2333 len = h->address ? Ustrlen(h->address) : 7;
2334 if (len > maxaddlen) maxaddlen = len;
2336 for (h = addr->host_list; h; h = h->next)
2338 fprintf(f, " host %-*s ", maxlen, h->name);
2341 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2342 else if (tp->info->local)
2343 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2345 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2347 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2348 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2349 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2350 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2356 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2357 the -bv or -bt case). */
2360 tls_modify_variables(&tls_in);
2368 /*************************************************
2369 * Check headers for syntax errors *
2370 *************************************************/
2372 /* This function checks those header lines that contain addresses, and verifies
2373 that all the addresses therein are syntactially correct.
2376 msgptr where to put an error message
2383 verify_check_headers(uschar **msgptr)
2389 for (h = header_list; h != NULL && yield == OK; h = h->next)
2391 if (h->type != htype_from &&
2392 h->type != htype_reply_to &&
2393 h->type != htype_sender &&
2394 h->type != htype_to &&
2395 h->type != htype_cc &&
2396 h->type != htype_bcc)
2399 colon = Ustrchr(h->text, ':');
2401 while (isspace(*s)) s++;
2403 /* Loop for multiple addresses in the header, enabling group syntax. Note
2404 that we have to reset this after the header has been scanned. */
2406 parse_allow_group = TRUE;
2410 uschar *ss = parse_find_address_end(s, FALSE);
2411 uschar *recipient, *errmess;
2412 int terminator = *ss;
2413 int start, end, domain;
2415 /* Temporarily terminate the string at this point, and extract the
2416 operative address within, allowing group syntax. */
2419 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2422 /* Permit an unqualified address only if the message is local, or if the
2423 sending host is configured to be permitted to send them. */
2425 if (recipient != NULL && domain == 0)
2427 if (h->type == htype_from || h->type == htype_sender)
2429 if (!allow_unqualified_sender) recipient = NULL;
2433 if (!allow_unqualified_recipient) recipient = NULL;
2435 if (recipient == NULL) errmess = US"unqualified address not permitted";
2438 /* It's an error if no address could be extracted, except for the special
2439 case of an empty address. */
2441 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2443 uschar *verb = US"is";
2448 /* Arrange not to include any white space at the end in the
2449 error message or the header name. */
2451 while (t > s && isspace(t[-1])) t--;
2452 while (tt > h->text && isspace(tt[-1])) tt--;
2454 /* Add the address that failed to the error message, since in a
2455 header with very many addresses it is sometimes hard to spot
2456 which one is at fault. However, limit the amount of address to
2457 quote - cases have been seen where, for example, a missing double
2458 quote in a humungous To: header creates an "address" that is longer
2459 than string_sprintf can handle. */
2468 /* deconst cast ok as we're passing a non-const to string_printing() */
2469 *msgptr = US string_printing(
2470 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2471 errmess, tt - h->text, h->text, verb, len, s));
2474 break; /* Out of address loop */
2477 /* Advance to the next address */
2479 s = ss + (terminator? 1:0);
2480 while (isspace(*s)) s++;
2481 } /* Next address */
2483 parse_allow_group = FALSE;
2484 parse_found_group = FALSE;
2485 } /* Next header unless yield has been set FALSE */
2491 /*************************************************
2492 * Check header names for 8-bit characters *
2493 *************************************************/
2495 /* This function checks for invalid charcters in header names. See
2496 RFC 5322, 2.2. and RFC 6532, 3.
2499 msgptr where to put an error message
2506 verify_check_header_names_ascii(uschar **msgptr)
2511 for (h = header_list; h != NULL; h = h->next)
2513 colon = Ustrchr(h->text, ':');
2514 for(s = h->text; s < colon; s++)
2516 if ((*s < 33) || (*s > 126))
2518 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2519 colon - h->text, h->text);
2527 /*************************************************
2528 * Check for blind recipients *
2529 *************************************************/
2531 /* This function checks that every (envelope) recipient is mentioned in either
2532 the To: or Cc: header lines, thus detecting blind carbon copies.
2534 There are two ways of scanning that could be used: either scan the header lines
2535 and tick off the recipients, or scan the recipients and check the header lines.
2536 The original proposed patch did the former, but I have chosen to do the latter,
2537 because (a) it requires no memory and (b) will use fewer resources when there
2538 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2541 Returns: OK if there are no blind recipients
2542 FAIL if there is at least one blind recipient
2546 verify_check_notblind(void)
2549 for (i = 0; i < recipients_count; i++)
2553 uschar *address = recipients_list[i].address;
2555 for (h = header_list; !found && h != NULL; h = h->next)
2559 if (h->type != htype_to && h->type != htype_cc) continue;
2561 colon = Ustrchr(h->text, ':');
2563 while (isspace(*s)) s++;
2565 /* Loop for multiple addresses in the header, enabling group syntax. Note
2566 that we have to reset this after the header has been scanned. */
2568 parse_allow_group = TRUE;
2572 uschar *ss = parse_find_address_end(s, FALSE);
2573 uschar *recipient,*errmess;
2574 int terminator = *ss;
2575 int start, end, domain;
2577 /* Temporarily terminate the string at this point, and extract the
2578 operative address within, allowing group syntax. */
2581 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2584 /* If we found a valid recipient that has a domain, compare it with the
2585 envelope recipient. Local parts are compared case-sensitively, domains
2586 case-insensitively. By comparing from the start with length "domain", we
2587 include the "@" at the end, which ensures that we are comparing the whole
2588 local part of each address. */
2590 if (recipient != NULL && domain != 0)
2592 found = Ustrncmp(recipient, address, domain) == 0 &&
2593 strcmpic(recipient + domain, address + domain) == 0;
2597 /* Advance to the next address */
2599 s = ss + (terminator? 1:0);
2600 while (isspace(*s)) s++;
2601 } /* Next address */
2603 parse_allow_group = FALSE;
2604 parse_found_group = FALSE;
2605 } /* Next header (if found is false) */
2607 if (!found) return FAIL;
2608 } /* Next recipient */
2615 /*************************************************
2616 * Find if verified sender *
2617 *************************************************/
2619 /* Usually, just a single address is verified as the sender of the message.
2620 However, Exim can be made to verify other addresses as well (often related in
2621 some way), and this is useful in some environments. There may therefore be a
2622 chain of such addresses that have previously been tested. This function finds
2623 whether a given address is on the chain.
2625 Arguments: the address to be verified
2626 Returns: pointer to an address item, or NULL
2630 verify_checked_sender(uschar *sender)
2633 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2634 if (Ustrcmp(sender, addr->address) == 0) break;
2642 /*************************************************
2643 * Get valid header address *
2644 *************************************************/
2646 /* Scan the originator headers of the message, looking for an address that
2647 verifies successfully. RFC 822 says:
2649 o The "Sender" field mailbox should be sent notices of
2650 any problems in transport or delivery of the original
2651 messages. If there is no "Sender" field, then the
2652 "From" field mailbox should be used.
2654 o If the "Reply-To" field exists, then the reply should
2655 go to the addresses indicated in that field and not to
2656 the address(es) indicated in the "From" field.
2658 So we check a Sender field if there is one, else a Reply_to field, else a From
2659 field. As some strange messages may have more than one of these fields,
2660 especially if they are resent- fields, check all of them if there is more than
2664 user_msgptr points to where to put a user error message
2665 log_msgptr points to where to put a log error message
2666 callout timeout for callout check (passed to verify_address())
2667 callout_overall overall callout timeout (ditto)
2668 callout_connect connect callout timeout (ditto)
2669 se_mailfrom mailfrom for verify; NULL => ""
2670 pm_mailfrom sender for pm callout check (passed to verify_address())
2671 options callout options (passed to verify_address())
2672 verrno where to put the address basic_errno
2674 If log_msgptr is set to something without setting user_msgptr, the caller
2675 normally uses log_msgptr for both things.
2677 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2678 FAIL is given if no appropriate headers are found
2682 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2683 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2684 uschar *pm_mailfrom, int options, int *verrno)
2686 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2691 for (i = 0; i < 3 && !done; i++)
2694 for (h = header_list; h != NULL && !done; h = h->next)
2696 int terminator, new_ok;
2697 uschar *s, *ss, *endname;
2699 if (h->type != header_types[i]) continue;
2700 s = endname = Ustrchr(h->text, ':') + 1;
2702 /* Scan the addresses in the header, enabling group syntax. Note that we
2703 have to reset this after the header has been scanned. */
2705 parse_allow_group = TRUE;
2709 address_item *vaddr;
2711 while (isspace(*s) || *s == ',') s++;
2712 if (*s == 0) break; /* End of header */
2714 ss = parse_find_address_end(s, FALSE);
2716 /* The terminator is a comma or end of header, but there may be white
2717 space preceding it (including newline for the last address). Move back
2718 past any white space so we can check against any cached envelope sender
2719 address verifications. */
2721 while (isspace(ss[-1])) ss--;
2725 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2726 (int)(endname - h->text), h->text, s);
2728 /* See if we have already verified this address as an envelope sender,
2729 and if so, use the previous answer. */
2731 vaddr = verify_checked_sender(s);
2733 if (vaddr != NULL && /* Previously checked */
2734 (callout <= 0 || /* No callout needed; OR */
2735 vaddr->special_action > 256)) /* Callout was done */
2737 new_ok = vaddr->special_action & 255;
2738 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2739 *ss = terminator; /* Restore shortened string */
2742 /* Otherwise we run the verification now. We must restore the shortened
2743 string before running the verification, so the headers are correct, in
2744 case there is any rewriting. */
2748 int start, end, domain;
2749 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2754 /* If we found an empty address, just carry on with the next one, but
2755 kill the message. */
2757 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2764 /* If verification failed because of a syntax error, fail this
2765 function, and ensure that the failing address gets added to the error
2768 if (address == NULL)
2771 while (ss > s && isspace(ss[-1])) ss--;
2772 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2773 "scanning for sender: %s in \"%.*s\"",
2774 endname - h->text, h->text, *log_msgptr, ss - s, s);
2780 /* Else go ahead with the sender verification. But it isn't *the*
2781 sender of the message, so set vopt_fake_sender to stop sender_address
2782 being replaced after rewriting or qualification. */
2786 vaddr = deliver_make_addr(address, FALSE);
2787 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2788 callout, callout_overall, callout_connect, se_mailfrom,
2793 /* We now have the result, either newly found, or cached. If we are
2794 giving out error details, set a specific user error. This means that the
2795 last of these will be returned to the user if all three fail. We do not
2796 set a log message - the generic one below will be used. */
2800 *verrno = vaddr->basic_errno;
2801 if (smtp_return_error_details)
2803 *user_msgptr = string_sprintf("Rejected after DATA: "
2804 "could not verify \"%.*s\" header address\n%s: %s",
2805 endname - h->text, h->text, vaddr->address, vaddr->message);
2809 /* Success or defer */
2818 if (new_ok == DEFER) yield = DEFER;
2820 /* Move on to any more addresses in the header */
2823 } /* Next address */
2825 parse_allow_group = FALSE;
2826 parse_found_group = FALSE;
2827 } /* Next header, unless done */
2828 } /* Next header type unless done */
2830 if (yield == FAIL && *log_msgptr == NULL)
2831 *log_msgptr = US"there is no valid sender in any header line";
2833 if (yield == DEFER && *log_msgptr == NULL)
2834 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2842 /*************************************************
2843 * Get RFC 1413 identification *
2844 *************************************************/
2846 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2847 the timeout is set to zero, then the query is not done. There may also be lists
2848 of hosts and nets which are exempt. To guard against malefactors sending
2849 non-printing characters which could, for example, disrupt a message's headers,
2850 make sure the string consists of printing characters only.
2853 port the port to connect to; usually this is IDENT_PORT (113), but when
2854 running in the test harness with -bh a different value is used.
2858 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2862 verify_get_ident(int port)
2864 int sock, host_af, qlen;
2865 int received_sender_port, received_interface_port, n;
2867 uschar buffer[2048];
2869 /* Default is no ident. Check whether we want to do an ident check for this
2872 sender_ident = NULL;
2873 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2876 DEBUG(D_ident) debug_printf("doing ident callback\n");
2878 /* Set up a connection to the ident port of the remote host. Bind the local end
2879 to the incoming interface address. If the sender host address is an IPv6
2880 address, the incoming interface address will also be IPv6. */
2882 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2883 sock = ip_socket(SOCK_STREAM, host_af);
2884 if (sock < 0) return;
2886 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2888 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2893 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2896 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2898 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2899 sender_host_address);
2903 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2904 sender_host_address, strerror(errno));
2909 /* Construct and send the query. */
2911 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2912 qlen = Ustrlen(buffer);
2913 if (send(sock, buffer, qlen, 0) < 0)
2915 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2919 /* Read a response line. We put it into the rest of the buffer, using several
2920 recv() calls if necessary. */
2928 int size = sizeof(buffer) - (p - buffer);
2930 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2931 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2932 if (count <= 0) goto END_OFF; /* Read error or EOF */
2934 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2935 generous, and accept a plain \n terminator as well. The only illegal
2938 for (pp = p; pp < p + count; pp++)
2940 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2943 if (pp[-1] == '\r') pp--;
2945 goto GOT_DATA; /* Break out of both loops */
2949 /* Reached the end of the data without finding \n. Let the loop continue to
2950 read some more, if there is room. */
2957 /* We have received a line of data. Check it carefully. It must start with the
2958 same two port numbers that we sent, followed by data as defined by the RFC. For
2961 12345 , 25 : USERID : UNIX :root
2963 However, the amount of white space may be different to what we sent. In the
2964 "osname" field there may be several sub-fields, comma separated. The data we
2965 actually want to save follows the third colon. Some systems put leading spaces
2966 in it - we discard those. */
2968 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2969 &received_interface_port, &n) != 2 ||
2970 received_sender_port != sender_host_port ||
2971 received_interface_port != interface_port)
2974 p = buffer + qlen + n;
2975 while(isspace(*p)) p++;
2976 if (*p++ != ':') goto END_OFF;
2977 while(isspace(*p)) p++;
2978 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2980 while(isspace(*p)) p++;
2981 if (*p++ != ':') goto END_OFF;
2982 while (*p != 0 && *p != ':') p++;
2983 if (*p++ == 0) goto END_OFF;
2984 while(isspace(*p)) p++;
2985 if (*p == 0) goto END_OFF;
2987 /* The rest of the line is the data we want. We turn it into printing
2988 characters when we save it, so that it cannot mess up the format of any logging
2989 or Received: lines into which it gets inserted. We keep a maximum of 127
2990 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2992 sender_ident = US string_printing(string_copyn(p, 127));
2993 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
3003 /*************************************************
3004 * Match host to a single host-list item *
3005 *************************************************/
3007 /* This function compares a host (name or address) against a single item
3008 from a host list. The host name gets looked up if it is needed and is not
3009 already known. The function is called from verify_check_this_host() via
3010 match_check_list(), which is why most of its arguments are in a single block.
3013 arg the argument block (see below)
3014 ss the host-list item
3015 valueptr where to pass back looked up data, or NULL
3016 error for error message when returning ERROR
3019 host_name (a) the host name, or
3020 (b) NULL, implying use sender_host_name and
3021 sender_host_aliases, looking them up if required, or
3022 (c) the empty string, meaning that only IP address matches
3024 host_address the host address
3025 host_ipv4 the IPv4 address taken from an IPv6 one
3029 DEFER lookup deferred
3030 ERROR (a) failed to find the host name or IP address, or
3031 (b) unknown lookup type specified, or
3032 (c) host name encountered when only IP addresses are
3037 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
3039 check_host_block *cb = (check_host_block *)arg;
3042 BOOL iplookup = FALSE;
3043 BOOL isquery = FALSE;
3044 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
3049 /* Optimize for the special case when the pattern is "*". */
3051 if (*ss == '*' && ss[1] == 0) return OK;
3053 /* If the pattern is empty, it matches only in the case when there is no host -
3054 this can occur in ACL checking for SMTP input using the -bs option. In this
3055 situation, the host address is the empty string. */
3057 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
3058 if (*ss == 0) return FAIL;
3060 /* If the pattern is precisely "@" then match against the primary host name,
3061 provided that host name matching is permitted; if it's "@[]" match against the
3062 local host's IP addresses. */
3068 if (isiponly) return ERROR;
3069 ss = primary_hostname;
3071 else if (Ustrcmp(ss, "@[]") == 0)
3073 ip_address_item *ip;
3074 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
3075 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
3080 /* If the pattern is an IP address, optionally followed by a bitmask count, do
3081 a (possibly masked) comparision with the current IP address. */
3083 if (string_is_ip_address(ss, &maskoffset) != 0)
3084 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
3086 /* The pattern is not an IP address. A common error that people make is to omit
3087 one component of an IPv4 address, either by accident, or believing that, for
3088 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,
3089 which it isn't. (Those applications that do accept 1.2.3 as an IP address
3090 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
3091 ancient specification.) To aid in debugging these cases, we give a specific
3092 error if the pattern contains only digits and dots or contains a slash preceded
3093 only by digits and dots (a slash at the start indicates a file name and of
3094 course slashes may be present in lookups, but not preceded only by digits and
3097 for (t = ss; isdigit(*t) || *t == '.'; t++);
3098 if (*t == 0 || (*t == '/' && t != ss))
3100 *error = US"malformed IPv4 address or address mask";
3104 /* See if there is a semicolon in the pattern */
3106 semicolon = Ustrchr(ss, ';');
3108 /* If we are doing an IP address only match, then all lookups must be IP
3109 address lookups, even if there is no "net-". */
3113 iplookup = semicolon != NULL;
3116 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
3117 a lookup on a masked IP network, in textual form. We obey this code even if we
3118 have already set iplookup, so as to skip over the "net-" prefix and to set the
3119 mask length. The net- stuff really only applies to single-key lookups where the
3120 key is implicit. For query-style lookups the key is specified in the query.
3121 From release 4.30, the use of net- for query style is no longer needed, but we
3122 retain it for backward compatibility. */
3124 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
3127 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
3128 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
3129 iplookup = (*t++ == '-');
3133 /* Do the IP address lookup if that is indeed what we have */
3141 uschar *filename, *key, *result;
3144 /* Find the search type */
3146 search_type = search_findtype(t, semicolon - t);
3148 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3149 search_error_message);
3151 /* Adjust parameters for the type of lookup. For a query-style lookup, there
3152 is no file name, and the "key" is just the query. For query-style with a file
3153 name, we have to fish the file off the start of the query. For a single-key
3154 lookup, the key is the current IP address, masked appropriately, and
3155 reconverted to text form, with the mask appended. For IPv6 addresses, specify
3156 dot separators instead of colons, except when the lookup type is "iplsearch".
3159 if (mac_islookup(search_type, lookup_absfilequery))
3161 filename = semicolon + 1;
3163 while (*key != 0 && !isspace(*key)) key++;
3164 filename = string_copyn(filename, key - filename);
3165 while (isspace(*key)) key++;
3167 else if (mac_islookup(search_type, lookup_querystyle))
3170 key = semicolon + 1;
3172 else /* Single-key style */
3174 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3176 insize = host_aton(cb->host_address, incoming);
3177 host_mask(insize, incoming, mlen);
3178 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3180 filename = semicolon + 1;
3183 /* Now do the actual lookup; note that there is no search_close() because
3184 of the caching arrangements. */
3186 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
3187 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
3189 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3190 if (valueptr != NULL) *valueptr = result;
3191 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3194 /* The pattern is not an IP address or network reference of any kind. That is,
3195 it is a host name pattern. If this is an IP only match, there's an error in the
3200 *error = US"cannot match host name in match_ip list";
3204 /* Check the characters of the pattern to see if they comprise only letters,
3205 digits, full stops, and hyphens (the constituents of domain names). Allow
3206 underscores, as they are all too commonly found. Sigh. Also, if
3207 allow_utf8_domains is set, allow top-bit characters. */
3209 for (t = ss; *t != 0; t++)
3210 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3211 (!allow_utf8_domains || *t < 128)) break;
3213 /* If the pattern is a complete domain name, with no fancy characters, look up
3214 its IP address and match against that. Note that a multi-homed host will add
3215 items to the chain. */
3226 /* Using byname rather than bydns here means we cannot determine dnssec
3227 status. On the other hand it is unclear how that could be either
3228 propagated up or enforced. */
3230 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3231 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3234 for (hh = &h; hh != NULL; hh = hh->next)
3236 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3240 if (rc == HOST_FIND_AGAIN) return DEFER;
3241 *error = string_sprintf("failed to find IP address for %s", ss);
3245 /* Almost all subsequent comparisons require the host name, and can be done
3246 using the general string matching function. When this function is called for
3247 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3248 must use sender_host_name and its aliases, looking them up if necessary. */
3250 if (cb->host_name != NULL) /* Explicit host name given */
3251 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3254 /* Host name not given; in principle we need the sender host name and its
3255 aliases. However, for query-style lookups, we do not need the name if the
3256 query does not contain $sender_host_name. From release 4.23, a reference to
3257 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3260 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3262 const uschar *affix;
3263 int partial, affixlen, starflags, id;
3266 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3269 if (id < 0) /* Unknown lookup type */
3271 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3272 search_error_message, ss);
3275 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3280 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3283 case DEFER: return DEFER;
3284 default: return FAIL;
3288 /* Not a query-style lookup; must ensure the host name is present, and then we
3289 do a check on the name and all its aliases. */
3291 if (sender_host_name == NULL)
3293 HDEBUG(D_host_lookup)
3294 debug_printf("sender host name required, to match against %s\n", ss);
3295 if (host_lookup_failed || host_name_lookup() != OK)
3297 *error = string_sprintf("failed to find host name for %s",
3298 sender_host_address);;
3301 host_build_sender_fullhost();
3304 /* Match on the sender host name, using the general matching function */
3306 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3310 case DEFER: return DEFER;
3313 /* If there are aliases, try matching on them. */
3315 aliases = sender_host_aliases;
3316 while (*aliases != NULL)
3318 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3321 case DEFER: return DEFER;
3330 /*************************************************
3331 * Check a specific host matches a host list *
3332 *************************************************/
3334 /* This function is passed a host list containing items in a number of
3335 different formats and the identity of a host. Its job is to determine whether
3336 the given host is in the set of hosts defined by the list. The host name is
3337 passed as a pointer so that it can be looked up if needed and not already
3338 known. This is commonly the case when called from verify_check_host() to check
3339 an incoming connection. When called from elsewhere the host name should usually
3342 This function is now just a front end to match_check_list(), which runs common
3343 code for scanning a list. We pass it the check_host() function to perform a
3347 listptr pointer to the host list
3348 cache_bits pointer to cache for named lists, or NULL
3349 host_name the host name or NULL, implying use sender_host_name and
3350 sender_host_aliases, looking them up if required
3351 host_address the IP address
3352 valueptr if not NULL, data from a lookup is passed back here
3354 Returns: OK if the host is in the defined set
3355 FAIL if the host is not in the defined set,
3356 DEFER if a data lookup deferred (not a host lookup)
3358 If the host name was needed in order to make a comparison, and could not be
3359 determined from the IP address, the result is FAIL unless the item
3360 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3363 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3364 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3367 unsigned int *local_cache_bits = cache_bits;
3368 const uschar *save_host_address = deliver_host_address;
3369 check_host_block cb;
3370 cb.host_name = host_name;
3371 cb.host_address = host_address;
3373 if (valueptr != NULL) *valueptr = NULL;
3375 /* If the host address starts off ::ffff: it is an IPv6 address in
3376 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3379 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3380 host_address + 7 : host_address;
3382 /* During the running of the check, put the IP address into $host_address. In
3383 the case of calls from the smtp transport, it will already be there. However,
3384 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3385 the safe side, any existing setting is preserved, though as I write this
3386 (November 2004) I can't see any cases where it is actually needed. */
3388 deliver_host_address = host_address;
3389 rc = match_check_list(
3390 listptr, /* the list */
3391 0, /* separator character */
3392 &hostlist_anchor, /* anchor pointer */
3393 &local_cache_bits, /* cache pointer */
3394 check_host, /* function for testing */
3395 &cb, /* argument for function */
3396 MCL_HOST, /* type of check */
3397 (host_address == sender_host_address)?
3398 US"host" : host_address, /* text for debugging */
3399 valueptr); /* where to pass back data */
3400 deliver_host_address = save_host_address;
3407 /*************************************************
3408 * Check the given host item matches a list *
3409 *************************************************/
3411 verify_check_given_host(uschar **listptr, host_item *host)
3413 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3416 /*************************************************
3417 * Check the remote host matches a list *
3418 *************************************************/
3420 /* This is a front end to verify_check_this_host(), created because checking
3421 the remote host is a common occurrence. With luck, a good compiler will spot
3422 the tail recursion and optimize it. If there's no host address, this is
3423 command-line SMTP input - check against an empty string for the address.
3426 listptr pointer to the host list
3428 Returns: the yield of verify_check_this_host(),
3429 i.e. OK, FAIL, or DEFER
3433 verify_check_host(uschar **listptr)
3435 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3436 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3443 /*************************************************
3444 * Invert an IP address *
3445 *************************************************/
3447 /* Originally just used for DNS xBL lists, now also used for the
3448 reverse_ip expansion operator.
3451 buffer where to put the answer
3452 address the address to invert
3456 invert_address(uschar *buffer, uschar *address)
3459 uschar *bptr = buffer;
3461 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3462 to the IPv4 part only. */
3464 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3466 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3469 if (host_aton(address, bin) == 1)
3473 for (i = 0; i < 4; i++)
3475 sprintf(CS bptr, "%d.", x & 255);
3476 while (*bptr) bptr++;
3481 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3482 in any DNS black lists, and the format in which they will be looked up is
3483 unknown. This is just a guess. */
3489 for (j = 3; j >= 0; j--)
3492 for (i = 0; i < 8; i++)
3494 sprintf(CS bptr, "%x.", x & 15);
3495 while (*bptr) bptr++;
3502 /* Remove trailing period -- this is needed so that both arbitrary
3503 dnsbl keydomains and inverted addresses may be combined with the
3504 same format string, "%s.%s" */
3511 /*************************************************
3512 * Perform a single dnsbl lookup *
3513 *************************************************/
3515 /* This function is called from verify_check_dnsbl() below. It is also called
3516 recursively from within itself when domain and domain_txt are different
3517 pointers, in order to get the TXT record from the alternate domain.
3520 domain the outer dnsbl domain
3521 domain_txt alternate domain to lookup TXT record on success; when the
3522 same domain is to be used, domain_txt == domain (that is,
3523 the pointers must be identical, not just the text)
3524 keydomain the current keydomain (for debug message)
3525 prepend subdomain to lookup (like keydomain, but
3526 reversed if IP address)
3527 iplist the list of matching IP addresses, or NULL for "any"
3528 bitmask true if bitmask matching is wanted
3529 match_type condition for 'succeed' result
3530 0 => Any RR in iplist (=)
3531 1 => No RR in iplist (!=)
3532 2 => All RRs in iplist (==)
3533 3 => Some RRs not in iplist (!==)
3534 the two bits are defined as MT_NOT and MT_ALL
3535 defer_return what to return for a defer
3537 Returns: OK if lookup succeeded
3542 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3543 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3549 dnsbl_cache_block *cb;
3550 int old_pool = store_pool;
3551 uschar query[256]; /* DNS domain max length */
3553 /* Construct the specific query domainname */
3555 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3557 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3558 "(ignored): %s...", query);
3562 /* Look for this query in the cache. */
3564 if ( (t = tree_search(dnsbl_cache, query))
3565 && (cb = t->data.ptr)->expiry > time(NULL)
3568 /* Previous lookup was cached */
3571 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3574 /* If not cached from a previous lookup, we must do a DNS lookup, and
3575 cache the result in permanent memory. */
3581 store_pool = POOL_PERM;
3585 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3589 { /* Set up a tree entry to cache the lookup */
3590 t = store_get(sizeof(tree_node) + Ustrlen(query));
3591 Ustrcpy(t->name, query);
3592 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3593 (void)tree_insertnode(&dnsbl_cache, t);
3596 /* Do the DNS loopup . */
3598 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3599 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3600 cb->text_set = FALSE;
3604 /* If the lookup succeeded, cache the RHS address. The code allows for
3605 more than one address - this was for complete generality and the possible
3606 use of A6 records. However, A6 records have been reduced to experimental
3607 status (August 2001) and may die out. So they may never get used at all,
3608 let alone in dnsbl records. However, leave the code here, just in case.
3610 Quite apart from one A6 RR generating multiple addresses, there are DNS
3611 lists that return more than one A record, so we must handle multiple
3612 addresses generated in that way as well.
3614 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3615 or some suitably far-future time if none were found. */
3617 if (cb->rc == DNS_SUCCEED)
3620 dns_address **addrp = &(cb->rhs);
3621 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3623 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3625 if (rr->type == T_A)
3627 dns_address *da = dns_address_from_rr(&dnsa, rr);
3631 while (da->next != NULL) da = da->next;
3632 addrp = &(da->next);
3633 if (ttl > rr->ttl) ttl = rr->ttl;
3638 /* If we didn't find any A records, change the return code. This can
3639 happen when there is a CNAME record but there are no A records for what
3642 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3645 cb->expiry = time(NULL)+ttl;
3646 store_pool = old_pool;
3649 /* We now have the result of the DNS lookup, either newly done, or cached
3650 from a previous call. If the lookup succeeded, check against the address
3651 list if there is one. This may be a positive equality list (introduced by
3652 "="), a negative equality list (introduced by "!="), a positive bitmask
3653 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3655 if (cb->rc == DNS_SUCCEED)
3657 dns_address *da = NULL;
3658 uschar *addlist = cb->rhs->address;
3660 /* For A and AAAA records, there may be multiple addresses from multiple
3661 records. For A6 records (currently not expected to be used) there may be
3662 multiple addresses from a single record. */
3664 for (da = cb->rhs->next; da != NULL; da = da->next)
3665 addlist = string_sprintf("%s, %s", addlist, da->address);
3667 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3670 /* Address list check; this can be either for equality, or via a bitmask.
3671 In the latter case, all the bits must match. */
3675 for (da = cb->rhs; da != NULL; da = da->next)
3679 const uschar *ptr = iplist;
3682 /* Handle exact matching */
3686 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3688 if (Ustrcmp(CS da->address, ip) == 0) break;
3692 /* Handle bitmask matching */
3699 /* At present, all known DNS blocking lists use A records, with
3700 IPv4 addresses on the RHS encoding the information they return. I
3701 wonder if this will linger on as the last vestige of IPv4 when IPv6
3702 is ubiquitous? Anyway, for now we use paranoia code to completely
3703 ignore IPv6 addresses. The default mask is 0, which always matches.
3704 We change this only for IPv4 addresses in the list. */
3706 if (host_aton(da->address, address) == 1) mask = address[0];
3708 /* Scan the returned addresses, skipping any that are IPv6 */
3710 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3712 if (host_aton(ip, address) != 1) continue;
3713 if ((address[0] & mask) == address[0]) break;
3719 (a) An IP address in an any ('=') list matched, or
3720 (b) No IP address in an all ('==') list matched
3722 then we're done searching. */
3724 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3727 /* If da == NULL, either
3729 (a) No IP address in an any ('=') list matched, or
3730 (b) An IP address in an all ('==') list didn't match
3732 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3735 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3743 res = US"was no match";
3746 res = US"was an exclude match";
3749 res = US"was an IP address that did not match";
3752 res = US"were no IP addresses that did not match";
3755 debug_printf("=> but we are not accepting this block class because\n");
3756 debug_printf("=> there %s for %s%c%s\n",
3758 ((match_type & MT_ALL) == 0)? "" : "=",
3759 bitmask? '&' : '=', iplist);
3765 /* Either there was no IP list, or the record matched, implying that the
3766 domain is on the list. We now want to find a corresponding TXT record. If an
3767 alternate domain is specified for the TXT record, call this function
3768 recursively to look that up; this has the side effect of re-checking that
3769 there is indeed an A record at the alternate domain. */
3771 if (domain_txt != domain)
3772 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3773 FALSE, match_type, defer_return);
3775 /* If there is no alternate domain, look up a TXT record in the main domain
3776 if it has not previously been cached. */
3780 cb->text_set = TRUE;
3781 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3784 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3786 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3787 if (rr->type == T_TXT) break;
3790 int len = (rr->data)[0];
3791 if (len > 511) len = 127;
3792 store_pool = POOL_PERM;
3793 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3794 store_pool = old_pool;
3799 dnslist_value = addlist;
3800 dnslist_text = cb->text;
3804 /* There was a problem with the DNS lookup */
3806 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3808 log_write(L_dnslist_defer, LOG_MAIN,
3809 "DNS list lookup defer (probably timeout) for %s: %s", query,
3810 (defer_return == OK)? US"assumed in list" :
3811 (defer_return == FAIL)? US"assumed not in list" :
3812 US"returned DEFER");
3813 return defer_return;
3816 /* No entry was found in the DNS; continue for next domain */
3820 debug_printf("DNS lookup for %s failed\n", query);
3821 debug_printf("=> that means %s is not listed at %s\n",
3831 /*************************************************
3832 * Check host against DNS black lists *
3833 *************************************************/
3835 /* This function runs checks against a list of DNS black lists, until one
3836 matches. Each item on the list can be of the form
3838 domain=ip-address/key
3840 The domain is the right-most domain that is used for the query, for example,
3841 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3842 if the DNS lookup returns a matching IP address. Several addresses may be
3843 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3845 If no key is given, what is looked up in the domain is the inverted IP address
3846 of the current client host. If a key is given, it is used to construct the
3847 domain for the lookup. For example:
3849 dsn.rfc-ignorant.org/$sender_address_domain
3851 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3852 then we check for a TXT record for an error message, and if found, save its
3853 value in $dnslist_text. We also cache everything in a tree, to optimize
3856 The TXT record is normally looked up in the same domain as the A record, but
3857 when many lists are combined in a single DNS domain, this will not be a very
3858 specific message. It is possible to specify a different domain for looking up
3859 TXT records; this is given before the main domain, comma-separated. For
3862 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3863 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3865 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3867 Note: an address for testing RBL is 192.203.178.39
3868 Note: an address for testing DUL is 192.203.178.4
3869 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3873 listptr the domain/address/data list
3874 log_msgptr log message on error
3876 Returns: OK successful lookup (i.e. the address is on the list), or
3877 lookup deferred after +include_unknown
3878 FAIL name not found, or no data found for the given type, or
3879 lookup deferred after +exclude_unknown (default)
3880 DEFER lookup failure, if +defer_unknown was set
3884 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3887 int defer_return = FAIL;
3888 const uschar *list = *listptr;
3891 uschar buffer[1024];
3892 uschar revadd[128]; /* Long enough for IPv6 address */
3894 /* Indicate that the inverted IP address is not yet set up */
3898 /* In case this is the first time the DNS resolver is being used. */
3900 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3902 /* Loop through all the domains supplied, until something matches */
3904 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3907 BOOL bitmask = FALSE;
3914 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3916 /* Deal with special values that change the behaviour on defer */
3918 if (domain[0] == '+')
3920 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3921 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3922 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3924 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3929 /* See if there's explicit data to be looked up */
3931 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3933 /* See if there's a list of addresses supplied after the domain name. This is
3934 introduced by an = or a & character; if preceded by = we require all matches
3935 and if preceded by ! we invert the result. */
3937 if (!(iplist = Ustrchr(domain, '=')))
3940 iplist = Ustrchr(domain, '&');
3943 if (iplist) /* Found either = or & */
3945 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3947 match_type |= MT_NOT;
3951 *iplist++ = 0; /* Terminate domain, move on */
3953 /* If we found = (bitmask == FALSE), check for == or =& */
3955 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3957 bitmask = *iplist++ == '&';
3958 match_type |= MT_ALL;
3963 /* If there is a comma in the domain, it indicates that a second domain for
3964 looking up TXT records is provided, before the main domain. Otherwise we must
3965 set domain_txt == domain. */
3967 domain_txt = domain;
3968 comma = Ustrchr(domain, ',');
3975 /* Check that what we have left is a sensible domain name. There is no reason
3976 why these domains should in fact use the same syntax as hosts and email
3977 domains, but in practice they seem to. However, there is little point in
3978 actually causing an error here, because that would no doubt hold up incoming
3979 mail. Instead, I'll just log it. */
3981 for (s = domain; *s != 0; s++)
3983 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3985 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3986 "strange characters - is this right?", domain);
3991 /* Check the alternate domain if present */
3993 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3995 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3997 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3998 "strange characters - is this right?", domain_txt);
4003 /* If there is no key string, construct the query by adding the domain name
4004 onto the inverted host address, and perform a single DNS lookup. */
4008 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
4010 *log_msgptr = string_sprintf
4011 ("cannot test auto-keyed dnslists condition in %s ACL",
4012 acl_wherenames[where]);
4015 if (sender_host_address == NULL) return FAIL; /* can never match */
4016 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
4017 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
4018 iplist, bitmask, match_type, defer_return);
4021 dnslist_domain = string_copy(domain_txt);
4022 dnslist_matched = string_copy(sender_host_address);
4023 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4024 sender_host_address, dnslist_domain);
4026 if (rc != FAIL) return rc; /* OK or DEFER */
4029 /* If there is a key string, it can be a list of domains or IP addresses to
4030 be concatenated with the main domain. */
4037 uschar keybuffer[256];
4038 uschar keyrevadd[128];
4040 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
4041 sizeof(keybuffer))) != NULL)
4043 uschar *prepend = keydomain;
4045 if (string_is_ip_address(keydomain, NULL) != 0)
4047 invert_address(keyrevadd, keydomain);
4048 prepend = keyrevadd;
4051 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
4052 bitmask, match_type, defer_return);
4056 dnslist_domain = string_copy(domain_txt);
4057 dnslist_matched = string_copy(keydomain);
4058 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4059 keydomain, dnslist_domain);
4063 /* If the lookup deferred, remember this fact. We keep trying the rest
4064 of the list to see if we get a useful result, and if we don't, we return
4065 DEFER at the end. */
4067 if (rc == DEFER) defer = TRUE;
4068 } /* continue with next keystring domain/address */
4070 if (defer) return DEFER;
4072 } /* continue with next dnsdb outer domain */
4079 /* End of verify.c */