1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2015 */
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
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 (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
646 && (rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK
650 else if (dane_required)
652 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
657 ob->tls_tempfail_tryclear = FALSE;
661 /* Expand the helo_data string to find the host name to use. */
663 if (tf->helo_data != NULL)
665 uschar *s = expand_string(tf->helo_data);
667 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
668 "helo_data value for callout: %s", addr->address,
669 expand_string_message);
670 else active_hostname = s;
673 /* Wait for initial response, and send HELO. The smtp_write_command()
674 function leaves its command in big_buffer. This is used in error responses.
675 Initialize it in case the connection is rejected. */
677 Ustrcpy(big_buffer, "initial connection");
679 /* Unless ssl-on-connect, wait for the initial greeting */
683 if (!smtps || (smtps && tls_out.active >= 0))
686 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
687 goto RESPONSE_FAILED;
689 #ifndef DISABLE_EVENT
690 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
691 : host->dnssec==DS_NO ? US"no" : NULL;
692 if (event_raise(addr->transport->event_action,
693 US"smtp:connect", responsebuffer))
695 lookup_dnssec_authenticated = NULL;
696 /* Logging? Debug? */
697 goto RESPONSE_FAILED;
699 lookup_dnssec_authenticated = NULL;
703 /* Not worth checking greeting line for ESMTP support */
704 if (!(esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK))
706 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
711 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
713 peer_offered &= ~PEER_OFFERED_TLS;
714 ob->tls_tempfail_tryclear = FALSE;
716 else /* all other cases */
721 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
722 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
724 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
726 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
729 goto RESPONSE_FAILED;
732 peer_offered &= ~PEER_OFFERED_TLS;
735 goto esmtp_retry; /* fallback to HELO */
738 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
741 ? ehlo_response(responsebuffer, sizeof(responsebuffer),
742 (!suppress_tls && tls_out.active < 0 ? PEER_OFFERED_TLS : 0)
746 | (addr->prop.utf8_msg && !addr->prop.utf8_downcvt
747 ? PEER_OFFERED_UTF8 : 0)
752 /* only care about SIZE if we have size from inbound */
753 | (message_size > 0 && ob->size_addition >= 0
754 ? PEER_OFFERED_SIZE : 0)
759 size_str = peer_offered & PEER_OFFERED_SIZE
760 ? string_sprintf(" SIZE=%d", message_size + ob->size_addition) : US"";
763 tls_offered = !!(peer_offered & PEER_OFFERED_TLS);
766 /* If TLS is available on this connection attempt to
767 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
768 send another EHLO - the server may give a different answer in secure mode. We
769 use a separate buffer for reading the response to STARTTLS so that if it is
770 negative, the original EHLO data is available for subsequent analysis, should
771 the client not be required to use TLS. If the response is bad, copy the buffer
772 for error analysis. */
775 if ( peer_offered & PEER_OFFERED_TLS
776 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK
777 && verify_check_given_host(&ob->hosts_verify_avoid_tls, host) != OK
780 uschar buffer2[4096];
782 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
785 /* If there is an I/O error, transmission of this message is deferred. If
786 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
787 false, we also defer. However, if there is a temporary rejection of STARTTLS
788 and tls_tempfail_tryclear is true, or if there is an outright rejection of
789 STARTTLS, we carry on. This means we will try to send the message in clear,
790 unless the host is in hosts_require_tls (tested below). */
792 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
793 ob->command_timeout))
795 if (errno != 0 || buffer2[0] == 0 ||
796 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
798 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
800 goto RESPONSE_FAILED;
804 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
807 int oldtimeout = ob->command_timeout;
811 ob->command_timeout = callout;
812 rc = tls_client_start(inblock.sock, host, addr, addr->transport
813 # ifdef EXPERIMENTAL_DANE
814 , dane ? &tlsa_dnsa : NULL
817 ob->command_timeout = oldtimeout;
819 /* TLS negotiation failed; give an error. Try in clear on a new
820 connection, if the options permit it for this host. */
825 (void)close(inblock.sock);
826 # ifndef DISABLE_EVENT
827 (void) event_raise(addr->transport->event_action,
828 US"tcp:close", NULL);
830 # ifdef EXPERIMENTAL_DANE
835 log_write(0, LOG_MAIN, "DANE attempt failed;"
836 " trying CA-root TLS to %s [%s] (not in hosts_require_dane)",
837 host->name, host->address);
844 if ( ob->tls_tempfail_tryclear
846 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
849 log_write(0, LOG_MAIN, "TLS session failure:"
850 " delivering unencrypted to %s [%s] (not in hosts_require_tls)",
851 host->name, host->address);
853 goto tls_retry_connection;
857 /*save_errno = ERRNO_TLSFAILURE;*/
858 /*message = US"failure while setting up TLS session";*/
864 /* TLS session is set up. Copy info for logging. */
865 addr->cipher = tls_out.cipher;
866 addr->peerdn = tls_out.peerdn;
868 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
870 goto smtps_redo_greeting;
872 /* For STARTTLS we need to redo EHLO */
877 /* If the host is required to use a secure channel, ensure that we have one. */
878 if (tls_out.active < 0)
880 # ifdef EXPERIMENTAL_DANE
883 verify_check_given_host(&ob->hosts_require_tls, host) == OK
886 /*save_errno = ERRNO_TLSREQUIRED;*/
887 log_write(0, LOG_MAIN,
888 "H=%s [%s]: a TLS session is required for this host, but %s",
889 host->name, host->address,
890 peer_offered & PEER_OFFERED_TLS
891 ? "an attempt to start TLS failed"
892 : "the server did not offer TLS support");
897 #endif /*SUPPORT_TLS*/
899 done = TRUE; /* so far so good; have response to HELO */
901 /* For now, transport_filter by cutthrough-delivery is not supported */
902 /* Need proper integration with the proper transport mechanism. */
903 if (cutthrough.delivery)
905 if (addr->transport->filter_command)
907 cutthrough.delivery = FALSE;
908 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
913 cutthrough.delivery = FALSE;
914 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
923 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
925 /* Failure to accept HELO is cached; this blocks the whole domain for all
926 senders. I/O errors and defer responses are not cached. */
930 *failure_ptr = US"mail"; /* At or before MAIL */
931 if (errno == 0 && responsebuffer[0] == '5')
933 setflag(addr, af_verify_nsfail);
934 new_domain_record.result = ccache_reject;
939 else if ( addr->prop.utf8_msg
940 && !addr->prop.utf8_downcvt
941 && !(peer_offered & PEER_OFFERED_UTF8)
944 HDEBUG(D_acl|D_v) debug_printf("utf8 required but not offered\n");
945 errno = ERRNO_UTF8_FWD;
946 setflag(addr, af_verify_nsfail);
949 else if ( addr->prop.utf8_msg
950 && (addr->prop.utf8_downcvt || !(peer_offered & PEER_OFFERED_UTF8))
951 && (setflag(addr, af_utf8_downcvt),
952 from_address = string_address_utf8_to_alabel(from_address,
957 errno = ERRNO_EXPANDFAIL;
958 setflag(addr, af_verify_nsfail);
963 /* If we haven't authenticated, but are required to, give up. */
966 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
967 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
969 /* Copy AUTH info for logging */
970 ( (addr->authenticator = client_authenticator),
971 (addr->auth_id = client_authenticated_id),
973 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
974 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
977 ( (addr->auth_sndr = client_authenticated_sender),
979 /* Send the MAIL command */
980 (smtp_write_command(&outblock, FALSE,
982 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
983 ? "MAIL FROM:<%s>%s%s SMTPUTF8\r\n"
986 "MAIL FROM:<%s>%s%s\r\n",
987 from_address, responsebuffer, size_str) >= 0)
990 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
993 deliver_host = deliver_host_address = NULL;
994 deliver_domain = save_deliver_domain;
996 /* If the host does not accept MAIL FROM:<>, arrange to cache this
997 information, but again, don't record anything for an I/O error or a defer. Do
998 not cache rejections of MAIL when a non-empty sender has been used, because
999 that blocks the whole domain for all senders. */
1003 *failure_ptr = US"mail"; /* At or before MAIL */
1004 if (errno == 0 && responsebuffer[0] == '5')
1006 setflag(addr, af_verify_nsfail);
1007 if (from_address[0] == 0)
1008 new_domain_record.result = ccache_reject_mfnull;
1012 /* Otherwise, proceed to check a "random" address (if required), then the
1013 given address, and the postmaster address (if required). Between each check,
1014 issue RSET, because some servers accept only one recipient after MAIL
1017 Before doing this, set the result in the domain cache record to "accept",
1018 unless its previous value was ccache_reject_mfnull. In that case, the domain
1019 rejects MAIL FROM:<> and we want to continue to remember that. When that is
1020 the case, we have got here only in the case of a recipient verification with
1021 a non-null sender. */
1025 const uschar * rcpt_domain = addr->domain;
1028 uschar * errstr = NULL;
1029 if ( testflag(addr, af_utf8_downcvt)
1030 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
1034 addr->message = errstr;
1035 errno = ERRNO_EXPANDFAIL;
1036 setflag(addr, af_verify_nsfail);
1038 rcpt_domain = US""; /*XXX errorhandling! */
1042 new_domain_record.result =
1043 (old_domain_cache_result == ccache_reject_mfnull)?
1044 ccache_reject_mfnull: ccache_accept;
1046 /* Do the random local part check first */
1048 if (random_local_part != NULL)
1050 uschar randombuffer[1024];
1052 smtp_write_command(&outblock, FALSE,
1053 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
1054 rcpt_domain) >= 0 &&
1055 smtp_read_response(&inblock, randombuffer,
1056 sizeof(randombuffer), '2', callout);
1058 /* Remember when we last did a random test */
1060 new_domain_record.random_stamp = time(NULL);
1062 /* If accepted, we aren't going to do any further tests below. */
1065 new_domain_record.random_result = ccache_accept;
1067 /* Otherwise, cache a real negative response, and get back to the right
1068 state to send RCPT. Unless there's some problem such as a dropped
1069 connection, we expect to succeed, because the commands succeeded above.
1070 However, some servers drop the connection after responding to an
1071 invalid recipient, so on (any) error we drop and remake the connection.
1074 else if (errno == 0)
1076 /* This would be ok for 1st rcpt a cutthrough, but no way to
1077 handle a subsequent. So refuse to support any */
1078 cancel_cutthrough_connection("random-recipient");
1080 if (randombuffer[0] == '5')
1081 new_domain_record.random_result = ccache_reject;
1084 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1085 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1088 smtp_write_command(&outblock, FALSE,
1090 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
1091 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
1094 "MAIL FROM:<%s>\r\n",
1095 from_address) >= 0 &&
1096 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1102 debug_printf("problem after random/rset/mfrom; reopen conn\n");
1103 random_local_part = NULL;
1105 tls_close(FALSE, TRUE);
1107 (void)close(inblock.sock);
1108 #ifndef DISABLE_EVENT
1109 (void) event_raise(addr->transport->event_action,
1110 US"tcp:close", NULL);
1112 goto tls_retry_connection;
1115 else done = FALSE; /* Some timeout/connection problem */
1116 } /* Random check */
1118 /* If the host is accepting all local parts, as determined by the "random"
1119 check, we don't need to waste time doing any further checking. */
1121 if (new_domain_record.random_result != ccache_accept && done)
1123 /* Get the rcpt_include_affixes flag from the transport if there is one,
1124 but assume FALSE if there is not. */
1126 uschar * rcpt = transport_rcpt_address(addr,
1127 addr->transport ? addr->transport->rcpt_include_affixes : FALSE);
1130 /*XXX should the conversion be moved into transport_rcpt_address() ? */
1131 uschar * dummy_errstr = NULL;
1132 if ( testflag(addr, af_utf8_downcvt)
1133 && (rcpt = string_address_utf8_to_alabel(rcpt, &dummy_errstr),
1137 errno = ERRNO_EXPANDFAIL;
1138 *failure_ptr = US"recipient";
1145 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
1147 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1151 new_address_record.result = ccache_accept;
1152 else if (errno == 0 && responsebuffer[0] == '5')
1154 *failure_ptr = US"recipient";
1155 new_address_record.result = ccache_reject;
1158 /* Do postmaster check if requested; if a full check is required, we
1159 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
1161 if (done && pm_mailfrom != NULL)
1163 /* Could possibly shift before main verify, just above, and be ok
1164 for cutthrough. But no way to handle a subsequent rcpt, so just
1166 cancel_cutthrough_connection("postmaster verify");
1167 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
1170 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1171 smtp_read_response(&inblock, responsebuffer,
1172 sizeof(responsebuffer), '2', callout) &&
1174 smtp_write_command(&outblock, FALSE,
1175 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
1176 smtp_read_response(&inblock, responsebuffer,
1177 sizeof(responsebuffer), '2', callout) &&
1179 /* First try using the current domain */
1182 smtp_write_command(&outblock, FALSE,
1183 "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 &&
1184 smtp_read_response(&inblock, responsebuffer,
1185 sizeof(responsebuffer), '2', callout)
1190 /* If that doesn't work, and a full check is requested,
1191 try without the domain. */
1194 (options & vopt_callout_fullpm) != 0 &&
1195 smtp_write_command(&outblock, FALSE,
1196 "RCPT TO:<postmaster>\r\n") >= 0 &&
1197 smtp_read_response(&inblock, responsebuffer,
1198 sizeof(responsebuffer), '2', callout)
1201 /* Sort out the cache record */
1203 new_domain_record.postmaster_stamp = time(NULL);
1206 new_domain_record.postmaster_result = ccache_accept;
1207 else if (errno == 0 && responsebuffer[0] == '5')
1209 *failure_ptr = US"postmaster";
1210 setflag(addr, af_verify_pmfail);
1211 new_domain_record.postmaster_result = ccache_reject;
1214 } /* Random not accepted */
1215 } /* MAIL FROM: accepted */
1217 /* For any failure of the main check, other than a negative response, we just
1218 close the connection and carry on. We can identify a negative response by the
1219 fact that errno is zero. For I/O errors it will be non-zero
1221 Set up different error texts for logging and for sending back to the caller
1222 as an SMTP response. Log in all cases, using a one-line format. For sender
1223 callouts, give a full response to the caller, but for recipient callouts,
1224 don't give the IP address because this may be an internal host whose identity
1225 is not to be widely broadcast. */
1229 if (errno == ETIMEDOUT)
1231 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1235 else if (errno == ERRNO_UTF8_FWD)
1237 extern int acl_where; /* src/acl.c */
1239 addr->message = string_sprintf(
1240 "response to \"%s\" from %s [%s] did not include SMTPUTF8",
1241 big_buffer, host->name, host->address);
1242 addr->user_message = acl_where == ACL_WHERE_RCPT
1243 ? US"533 mailbox name not allowed"
1244 : US"550 mailbox unavailable";
1249 else if (errno == 0)
1251 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1254 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1255 big_buffer, host->name, host->address,
1256 string_printing(responsebuffer));
1258 addr->user_message = is_recipient?
1259 string_sprintf("Callout verification failed:\n%s", responsebuffer)
1261 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1262 host->address, big_buffer, responsebuffer);
1264 /* Hard rejection ends the process */
1266 if (responsebuffer[0] == '5') /* Address rejected */
1274 /* End the SMTP conversation and close the connection. */
1276 /* Cutthrough - on a successfull connect and recipient-verify with
1277 use-sender and we are 1st rcpt and have no cutthrough conn so far
1278 here is where we want to leave the conn open */
1279 if ( cutthrough.delivery
1283 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
1284 && !random_local_part
1286 && cutthrough.fd < 0
1290 cutthrough.fd = outblock.sock; /* We assume no buffer in use in the outblock */
1291 cutthrough.nrcpt = 1;
1292 cutthrough.interface = interface;
1293 cutthrough.host = *host;
1294 cutthrough.addr = *addr; /* Save the address_item for later logging */
1295 cutthrough.addr.next = NULL;
1296 cutthrough.addr.host_used = &cutthrough.host;
1298 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1300 ctblock.buffer = ctbuffer;
1301 ctblock.buffersize = sizeof(ctbuffer);
1302 ctblock.ptr = ctbuffer;
1303 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1304 ctblock.sock = cutthrough.fd;
1308 /* Ensure no cutthrough on multiple address verifies */
1309 if (options & vopt_callout_recipsender)
1310 cancel_cutthrough_connection("multiple verify calls");
1311 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1314 tls_close(FALSE, TRUE);
1316 (void)close(inblock.sock);
1317 #ifndef DISABLE_EVENT
1318 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1322 } /* Loop through all hosts, while !done */
1325 /* If we get here with done == TRUE, a successful callout happened, and yield
1326 will be set OK or FAIL according to the response to the RCPT command.
1327 Otherwise, we looped through the hosts but couldn't complete the business.
1328 However, there may be domain-specific information to cache in both cases.
1330 The value of the result field in the new_domain record is ccache_unknown if
1331 there was an error before or with MAIL FROM:, and errno was not zero,
1332 implying some kind of I/O error. We don't want to write the cache in that case.
1333 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1335 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1337 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1340 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1344 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1345 (int)sizeof(dbdata_callout_cache));
1346 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1347 " result=%d postmaster=%d random=%d\n",
1348 new_domain_record.result,
1349 new_domain_record.postmaster_result,
1350 new_domain_record.random_result);
1354 /* If a definite result was obtained for the callout, cache it unless caching
1359 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1361 if (dbm_file == NULL)
1362 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1363 if (dbm_file == NULL)
1365 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1369 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1370 (int)sizeof(dbdata_callout_cache_address));
1371 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1372 (new_address_record.result == ccache_accept)? "positive" : "negative");
1377 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1378 temporary error. If there was only one host, and a response was received, leave
1379 it alone if supplying details. Otherwise, give a generic response. */
1383 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1384 is_recipient? "recipient" : "sender");
1387 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1389 addr->user_message = (!smtp_return_error_details)? dullmsg :
1390 string_sprintf("%s for <%s>.\n"
1391 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1392 "they may be permanently unreachable from this server. In the latter case,\n%s",
1393 dullmsg, addr->address,
1395 "the address will never be accepted."
1397 "you need to change the address or create an MX record for its domain\n"
1398 "if it is supposed to be generally accessible from the Internet.\n"
1399 "Talk to your mail administrator for details.");
1401 /* Force a specific error code */
1403 addr->basic_errno = ERRNO_CALLOUTDEFER;
1406 /* Come here from within the cache-reading code on fast-track exit. */
1409 if (dbm_file != NULL) dbfn_close(dbm_file);
1415 /* Called after recipient-acl to get a cutthrough connection open when
1416 one was requested and a recipient-verify wasn't subsequently done.
1419 open_cutthrough_connection( address_item * addr )
1423 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1424 /* We must use a copy of the address for verification, because it might
1428 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1429 rcpt_count > 1 ? "more" : "start");
1430 (void) verify_address(&addr2, NULL,
1431 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1432 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1434 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1440 /* Send given number of bytes from the buffer */
1442 cutthrough_send(int n)
1444 if(cutthrough.fd < 0)
1449 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1451 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1454 transport_count += n;
1455 ctblock.ptr= ctblock.buffer;
1459 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1466 _cutthrough_puts(uschar * cp, int n)
1470 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1471 if(!cutthrough_send(ctblock.buffersize))
1474 *ctblock.ptr++ = *cp++;
1479 /* Buffered output of counted data block. Return boolean success */
1481 cutthrough_puts(uschar * cp, int n)
1483 if (cutthrough.fd < 0) return TRUE;
1484 if (_cutthrough_puts(cp, n)) return TRUE;
1485 cancel_cutthrough_connection("transmit failed");
1491 _cutthrough_flush_send(void)
1493 int n= ctblock.ptr-ctblock.buffer;
1496 if(!cutthrough_send(n))
1502 /* Send out any bufferred output. Return boolean success. */
1504 cutthrough_flush_send(void)
1506 if (_cutthrough_flush_send()) return TRUE;
1507 cancel_cutthrough_connection("transmit failed");
1513 cutthrough_put_nl(void)
1515 return cutthrough_puts(US"\r\n", 2);
1519 /* Get and check response from cutthrough target */
1521 cutthrough_response(char expect, uschar ** copy)
1523 smtp_inblock inblock;
1524 uschar inbuffer[4096];
1525 uschar responsebuffer[4096];
1527 inblock.buffer = inbuffer;
1528 inblock.buffersize = sizeof(inbuffer);
1529 inblock.ptr = inbuffer;
1530 inblock.ptrend = inbuffer;
1531 inblock.sock = cutthrough.fd;
1532 /* this relies on (inblock.sock == tls_out.active) */
1533 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1534 cancel_cutthrough_connection("target timeout on read");
1539 *copy = cp = string_copy(responsebuffer);
1540 /* Trim the trailing end of line */
1541 cp += Ustrlen(responsebuffer);
1542 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1543 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1546 return responsebuffer[0];
1550 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1552 cutthrough_predata(void)
1554 if(cutthrough.fd < 0)
1557 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1558 cutthrough_puts(US"DATA\r\n", 6);
1559 cutthrough_flush_send();
1561 /* Assume nothing buffered. If it was it gets ignored. */
1562 return cutthrough_response('3', NULL) == '3';
1566 /* fd and use_crlf args only to match write_chunk() */
1568 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1571 while(s && (s2 = Ustrchr(s, '\n')))
1573 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1581 /* Buffered send of headers. Return success boolean. */
1582 /* Expands newlines to wire format (CR,NL). */
1583 /* Also sends header-terminating blank line. */
1585 cutthrough_headers_send(void)
1587 if(cutthrough.fd < 0)
1590 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1591 but having a separate buffered-output function (for now)
1593 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1595 if (!transport_headers_send(&cutthrough.addr, cutthrough.fd,
1596 cutthrough.addr.transport->add_headers,
1597 cutthrough.addr.transport->remove_headers,
1598 &cutthrough_write_chunk, TRUE,
1599 cutthrough.addr.transport->rewrite_rules,
1600 cutthrough.addr.transport->rewrite_existflags))
1603 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1609 close_cutthrough_connection(const char * why)
1611 if(cutthrough.fd >= 0)
1613 /* We could be sending this after a bunch of data, but that is ok as
1614 the only way to cancel the transfer in dataphase is to drop the tcp
1615 conn before the final dot.
1617 ctblock.ptr = ctbuffer;
1618 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1619 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1620 _cutthrough_flush_send();
1621 /* No wait for response */
1624 tls_close(FALSE, TRUE);
1626 (void)close(cutthrough.fd);
1628 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1630 ctblock.ptr = ctbuffer;
1634 cancel_cutthrough_connection(const char * why)
1636 close_cutthrough_connection(why);
1637 cutthrough.delivery = FALSE;
1643 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1644 Log an OK response as a transmission.
1645 Close the connection.
1646 Return smtp response-class digit.
1649 cutthrough_finaldot(void)
1652 address_item * addr;
1653 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1655 /* Assume data finshed with new-line */
1656 if( !cutthrough_puts(US".", 1)
1657 || !cutthrough_put_nl()
1658 || !cutthrough_flush_send()
1660 return cutthrough.addr.message;
1662 res = cutthrough_response('2', &cutthrough.addr.message);
1663 for (addr = &cutthrough.addr; addr; addr = addr->next)
1665 addr->message = cutthrough.addr.message;
1669 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1670 close_cutthrough_connection("delivered");
1674 delivery_log(LOG_MAIN, addr, 0,
1675 US"tmp-reject from cutthrough after DATA:");
1679 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1680 US"rejected after DATA:");
1687 return cutthrough.addr.message;
1692 /*************************************************
1693 * Copy error to toplevel address *
1694 *************************************************/
1696 /* This function is used when a verify fails or defers, to ensure that the
1697 failure or defer information is in the original toplevel address. This applies
1698 when an address is redirected to a single new address, and the failure or
1699 deferral happens to the child address.
1702 vaddr the verify address item
1703 addr the final address item
1706 Returns: the value of YIELD
1710 copy_error(address_item *vaddr, address_item *addr, int yield)
1714 vaddr->message = addr->message;
1715 vaddr->user_message = addr->user_message;
1716 vaddr->basic_errno = addr->basic_errno;
1717 vaddr->more_errno = addr->more_errno;
1718 vaddr->prop.address_data = addr->prop.address_data;
1719 copyflag(vaddr, addr, af_pass_message);
1727 /**************************************************
1728 * printf that automatically handles TLS if needed *
1729 ***************************************************/
1731 /* This function is used by verify_address() as a substitute for all fprintf()
1732 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1733 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1734 that assumes that we always use the smtp_out FILE* when not using TLS or the
1735 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1736 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1740 f the candidate FILE* to write to
1741 format format string
1742 ... optional arguments
1748 static void PRINTF_FUNCTION(2,3)
1749 respond_printf(FILE *f, const char *format, ...)
1753 va_start(ap, format);
1754 if (smtp_out && (f == smtp_out))
1755 smtp_vprintf(format, ap);
1757 vfprintf(f, format, ap);
1763 /*************************************************
1764 * Verify an email address *
1765 *************************************************/
1767 /* This function is used both for verification (-bv and at other times) and
1768 address testing (-bt), which is indicated by address_test_mode being set.
1771 vaddr contains the address to verify; the next field in this block
1773 f if not NULL, write the result to this file
1774 options various option bits:
1775 vopt_fake_sender => this sender verify is not for the real
1776 sender (it was verify=sender=xxxx or an address from a
1777 header line) - rewriting must not change sender_address
1778 vopt_is_recipient => this is a recipient address, otherwise
1779 it's a sender address - this affects qualification and
1780 rewriting and messages from callouts
1781 vopt_qualify => qualify an unqualified address; else error
1782 vopt_expn => called from SMTP EXPN command
1783 vopt_success_on_redirect => when a new address is generated
1784 the verification instantly succeeds
1786 These ones are used by do_callout() -- the options variable
1789 vopt_callout_fullpm => if postmaster check, do full one
1790 vopt_callout_no_cache => don't use callout cache
1791 vopt_callout_random => do the "random" thing
1792 vopt_callout_recipsender => use real sender for recipient
1793 vopt_callout_recippmaster => use postmaster for recipient
1795 callout if > 0, specifies that callout is required, and gives timeout
1796 for individual commands
1797 callout_overall if > 0, gives overall timeout for the callout function;
1798 if < 0, a default is used (see do_callout())
1799 callout_connect the connection timeout for callouts
1800 se_mailfrom when callout is requested to verify a sender, use this
1801 in MAIL FROM; NULL => ""
1802 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1803 thing and use this as the sender address (may be "")
1805 routed if not NULL, set TRUE if routing succeeded, so we can
1806 distinguish between routing failed and callout failed
1808 Returns: OK address verified
1809 FAIL address failed to verify
1810 DEFER can't tell at present
1814 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1815 int callout_overall, int callout_connect, uschar *se_mailfrom,
1816 uschar *pm_mailfrom, BOOL *routed)
1819 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1820 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1821 BOOL expn = (options & vopt_expn) != 0;
1822 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1825 int verify_type = expn? v_expn :
1826 address_test_mode? v_none :
1827 is_recipient? v_recipient : v_sender;
1828 address_item *addr_list;
1829 address_item *addr_new = NULL;
1830 address_item *addr_remote = NULL;
1831 address_item *addr_local = NULL;
1832 address_item *addr_succeed = NULL;
1833 uschar **failure_ptr = is_recipient?
1834 &recipient_verify_failure : &sender_verify_failure;
1835 uschar *ko_prefix, *cr;
1836 uschar *address = vaddr->address;
1837 uschar *save_sender;
1838 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1840 /* Clear, just in case */
1842 *failure_ptr = NULL;
1844 /* Set up a prefix and suffix for error message which allow us to use the same
1845 output statements both in EXPN mode (where an SMTP response is needed) and when
1846 debugging with an output file. */
1850 ko_prefix = US"553 ";
1853 else ko_prefix = cr = US"";
1855 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1857 if (parse_find_at(address) == NULL)
1859 if ((options & vopt_qualify) == 0)
1862 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1863 ko_prefix, address, cr);
1864 *failure_ptr = US"qualify";
1867 address = rewrite_address_qualify(address, is_recipient);
1872 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1873 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1876 /* Rewrite and report on it. Clear the domain and local part caches - these
1877 may have been set by domains and local part tests during an ACL. */
1879 if (global_rewrite_rules != NULL)
1881 uschar *old = address;
1882 address = rewrite_address(address, is_recipient, FALSE,
1883 global_rewrite_rules, rewrite_existflags);
1886 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1887 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1888 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1892 /* If this is the real sender address, we must update sender_address at
1893 this point, because it may be referred to in the routers. */
1895 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1896 sender_address = address;
1898 /* If the address was rewritten to <> no verification can be done, and we have
1899 to return OK. This rewriting is permitted only for sender addresses; for other
1900 addresses, such rewriting fails. */
1902 if (address[0] == 0) return OK;
1904 /* Flip the legacy TLS-related variables over to the outbound set in case
1905 they're used in the context of a transport used by verification. Reset them
1906 at exit from this routine. */
1908 tls_modify_variables(&tls_out);
1910 /* Save a copy of the sender address for re-instating if we change it to <>
1911 while verifying a sender address (a nice bit of self-reference there). */
1913 save_sender = sender_address;
1915 /* Update the address structure with the possibly qualified and rewritten
1916 address. Set it up as the starting address on the chain of new addresses. */
1918 vaddr->address = address;
1921 /* We need a loop, because an address can generate new addresses. We must also
1922 cope with generated pipes and files at the top level. (See also the code and
1923 comment in deliver.c.) However, it is usually the case that the router for
1924 user's .forward files has its verify flag turned off.
1926 If an address generates more than one child, the loop is used only when
1927 full_info is set, and this can only be set locally. Remote enquiries just get
1928 information about the top level address, not anything that it generated. */
1930 while (addr_new != NULL)
1933 address_item *addr = addr_new;
1935 addr_new = addr->next;
1940 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1941 debug_printf("Considering %s\n", addr->address);
1944 /* Handle generated pipe, file or reply addresses. We don't get these
1945 when handling EXPN, as it does only one level of expansion. */
1947 if (testflag(addr, af_pfr))
1954 if (addr->address[0] == '>')
1956 allow = testflag(addr, af_allow_reply);
1957 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1961 allow = (addr->address[0] == '|')?
1962 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1963 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1966 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1967 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1968 "%s\n", addr->message);
1970 fprintf(f, "\n transport = %s\n", addr->transport->name);
1972 fprintf(f, " *** forbidden ***\n");
1977 /* Just in case some router parameter refers to it. */
1979 return_path = (addr->prop.errors_address != NULL)?
1980 addr->prop.errors_address : sender_address;
1982 /* Split the address into domain and local part, handling the %-hack if
1983 necessary, and then route it. While routing a sender address, set
1984 $sender_address to <> because that is what it will be if we were trying to
1985 send a bounce to the sender. */
1987 if (routed != NULL) *routed = FALSE;
1988 if ((rc = deliver_split_address(addr)) == OK)
1990 if (!is_recipient) sender_address = null_sender;
1991 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1992 &addr_succeed, verify_type);
1993 sender_address = save_sender; /* Put back the real sender */
1996 /* If routing an address succeeded, set the flag that remembers, for use when
1997 an ACL cached a sender verify (in case a callout fails). Then if routing set
1998 up a list of hosts or the transport has a host list, and the callout option
1999 is set, and we aren't in a host checking run, do the callout verification,
2000 and set another flag that notes that a callout happened. */
2004 if (routed != NULL) *routed = TRUE;
2007 host_item *host_list = addr->host_list;
2008 transport_instance * tp;
2010 /* Make up some data for use in the case where there is no remote
2013 transport_feedback tf = {
2014 NULL, /* interface (=> any) */
2015 US"smtp", /* port */
2016 US"smtp", /* protocol */
2018 US"$smtp_active_hostname", /* helo_data */
2019 FALSE, /* hosts_override */
2020 FALSE, /* hosts_randomize */
2021 FALSE, /* gethostbyname */
2022 TRUE, /* qualify_single */
2023 FALSE /* search_parents */
2026 /* If verification yielded a remote transport, we want to use that
2027 transport's options, so as to mimic what would happen if we were really
2028 sending a message to this address. */
2030 if ((tp = addr->transport) && !tp->info->local)
2032 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
2034 /* If the transport has hosts and the router does not, or if the
2035 transport is configured to override the router's hosts, we must build a
2036 host list of the transport's hosts, and find the IP addresses */
2038 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
2041 const uschar *save_deliver_domain = deliver_domain;
2042 uschar *save_deliver_localpart = deliver_localpart;
2044 host_list = NULL; /* Ignore the router's hosts */
2046 deliver_domain = addr->domain;
2047 deliver_localpart = addr->local_part;
2048 s = expand_string(tf.hosts);
2049 deliver_domain = save_deliver_domain;
2050 deliver_localpart = save_deliver_localpart;
2054 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
2055 "\"%s\" in %s transport for callout: %s", tf.hosts,
2056 tp->name, expand_string_message);
2061 host_item *host, *nexthost;
2062 host_build_hostlist(&host_list, s, tf.hosts_randomize);
2064 /* Just ignore failures to find a host address. If we don't manage
2065 to find any addresses, the callout will defer. Note that more than
2066 one address may be found for a single host, which will result in
2067 additional host items being inserted into the chain. Hence we must
2068 save the next host first. */
2070 flags = HOST_FIND_BY_A;
2071 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2072 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2074 for (host = host_list; host != NULL; host = nexthost)
2076 nexthost = host->next;
2077 if (tf.gethostbyname ||
2078 string_is_ip_address(host->name, NULL) != 0)
2079 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
2082 dnssec_domains * dnssec_domains = NULL;
2083 if (Ustrcmp(tp->driver_name, "smtp") == 0)
2085 smtp_transport_options_block * ob =
2086 (smtp_transport_options_block *) tp->options_block;
2087 dnssec_domains = &ob->dnssec;
2090 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2091 dnssec_domains, NULL, NULL);
2098 /* Can only do a callout if we have at least one host! If the callout
2099 fails, it will have set ${sender,recipient}_verify_failure. */
2101 if (host_list != NULL)
2103 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
2104 if (host_checking && !host_checking_callout)
2107 debug_printf("... callout omitted by default when host testing\n"
2108 "(Use -bhc if you want the callouts to happen.)\n");
2113 deliver_set_expansions(addr);
2115 verify_mode = is_recipient ? US"R" : US"S";
2116 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
2117 callout_connect, options, se_mailfrom, pm_mailfrom);
2123 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
2124 "transport provided a host list\n");
2129 /* Otherwise, any failure is a routing failure */
2131 else *failure_ptr = US"route";
2133 /* A router may return REROUTED if it has set up a child address as a result
2134 of a change of domain name (typically from widening). In this case we always
2135 want to continue to verify the new child. */
2137 if (rc == REROUTED) continue;
2139 /* Handle hard failures */
2146 address_item *p = addr->parent;
2148 respond_printf(f, "%s%s %s", ko_prefix,
2149 full_info? addr->address : address,
2150 address_test_mode? "is undeliverable" : "failed to verify");
2151 if (!expn && admin_user)
2153 if (addr->basic_errno > 0)
2154 respond_printf(f, ": %s", strerror(addr->basic_errno));
2155 if (addr->message != NULL)
2156 respond_printf(f, ": %s", addr->message);
2159 /* Show parents iff doing full info */
2161 if (full_info) while (p != NULL)
2163 respond_printf(f, "%s\n <-- %s", cr, p->address);
2166 respond_printf(f, "%s\n", cr);
2168 cancel_cutthrough_connection("routing hard fail");
2172 yield = copy_error(vaddr, addr, FAIL);
2180 else if (rc == DEFER)
2185 address_item *p = addr->parent;
2186 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
2187 full_info? addr->address : address);
2188 if (!expn && admin_user)
2190 if (addr->basic_errno > 0)
2191 respond_printf(f, ": %s", strerror(addr->basic_errno));
2192 if (addr->message != NULL)
2193 respond_printf(f, ": %s", addr->message);
2194 else if (addr->basic_errno <= 0)
2195 respond_printf(f, ": unknown error");
2198 /* Show parents iff doing full info */
2200 if (full_info) while (p != NULL)
2202 respond_printf(f, "%s\n <-- %s", cr, p->address);
2205 respond_printf(f, "%s\n", cr);
2207 cancel_cutthrough_connection("routing soft fail");
2211 yield = copy_error(vaddr, addr, DEFER);
2214 else if (yield == OK) yield = DEFER;
2217 /* If we are handling EXPN, we do not want to continue to route beyond
2218 the top level (whose address is in "address"). */
2222 uschar *ok_prefix = US"250-";
2223 if (addr_new == NULL)
2225 if (addr_local == NULL && addr_remote == NULL)
2226 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2228 respond_printf(f, "250 <%s>\r\n", address);
2230 else while (addr_new != NULL)
2232 address_item *addr2 = addr_new;
2233 addr_new = addr2->next;
2234 if (addr_new == NULL) ok_prefix = US"250 ";
2235 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2241 /* Successful routing other than EXPN. */
2245 /* Handle successful routing when short info wanted. Otherwise continue for
2246 other (generated) addresses. Short info is the operational case. Full info
2247 can be requested only when debug_selector != 0 and a file is supplied.
2249 There is a conflict between the use of aliasing as an alternate email
2250 address, and as a sort of mailing list. If an alias turns the incoming
2251 address into just one address (e.g. J.Caesar->jc44) you may well want to
2252 carry on verifying the generated address to ensure it is valid when
2253 checking incoming mail. If aliasing generates multiple addresses, you
2254 probably don't want to do this. Exim therefore treats the generation of
2255 just a single new address as a special case, and continues on to verify the
2256 generated address. */
2258 if (!full_info && /* Stop if short info wanted AND */
2259 (((addr_new == NULL || /* No new address OR */
2260 addr_new->next != NULL || /* More than one new address OR */
2261 testflag(addr_new, af_pfr))) /* New address is pfr */
2263 (addr_new != NULL && /* At least one new address AND */
2264 success_on_redirect))) /* success_on_redirect is set */
2266 if (f != NULL) fprintf(f, "%s %s\n", address,
2267 address_test_mode? "is deliverable" : "verified");
2269 /* If we have carried on to verify a child address, we want the value
2270 of $address_data to be that of the child */
2272 vaddr->prop.address_data = addr->prop.address_data;
2277 } /* Loop for generated addresses */
2279 /* Display the full results of the successful routing, including any generated
2280 addresses. Control gets here only when full_info is set, which requires f not
2281 to be NULL, and this occurs only when a top-level verify is called with the
2282 debugging switch on.
2284 If there are no local and no remote addresses, and there were no pipes, files,
2285 or autoreplies, and there were no errors or deferments, the message is to be
2286 discarded, usually because of the use of :blackhole: in an alias file. */
2288 if (allok && addr_local == NULL && addr_remote == NULL)
2290 fprintf(f, "mail to %s is discarded\n", address);
2294 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2297 address_item *addr = addr_list;
2298 address_item *p = addr->parent;
2299 transport_instance * tp = addr->transport;
2301 addr_list = addr->next;
2303 fprintf(f, "%s", CS addr->address);
2304 #ifdef EXPERIMENTAL_SRS
2305 if(addr->prop.srs_sender)
2306 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2309 /* If the address is a duplicate, show something about it. */
2311 if (!testflag(addr, af_pfr))
2314 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2315 fprintf(f, " [duplicate, would not be delivered]");
2316 else tree_add_duplicate(addr->unique, addr);
2319 /* Now show its parents */
2321 for (p = addr->parent; p; p = p->parent)
2322 fprintf(f, "\n <-- %s", p->address);
2325 /* Show router, and transport */
2327 fprintf(f, "router = %s, transport = %s\n",
2328 addr->router->name, tp ? tp->name : US"unset");
2330 /* Show any hosts that are set up by a router unless the transport
2331 is going to override them; fiddle a bit to get a nice format. */
2333 if (addr->host_list && tp && !tp->overrides_hosts)
2338 for (h = addr->host_list; h; h = h->next)
2339 { /* get max lengths of host names, addrs */
2340 int len = Ustrlen(h->name);
2341 if (len > maxlen) maxlen = len;
2342 len = h->address ? Ustrlen(h->address) : 7;
2343 if (len > maxaddlen) maxaddlen = len;
2345 for (h = addr->host_list; h; h = h->next)
2347 fprintf(f, " host %-*s ", maxlen, h->name);
2350 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2351 else if (tp->info->local)
2352 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2354 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2356 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2357 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2358 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2359 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2365 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2366 the -bv or -bt case). */
2369 tls_modify_variables(&tls_in);
2377 /*************************************************
2378 * Check headers for syntax errors *
2379 *************************************************/
2381 /* This function checks those header lines that contain addresses, and verifies
2382 that all the addresses therein are syntactially correct.
2385 msgptr where to put an error message
2392 verify_check_headers(uschar **msgptr)
2398 for (h = header_list; h != NULL && yield == OK; h = h->next)
2400 if (h->type != htype_from &&
2401 h->type != htype_reply_to &&
2402 h->type != htype_sender &&
2403 h->type != htype_to &&
2404 h->type != htype_cc &&
2405 h->type != htype_bcc)
2408 colon = Ustrchr(h->text, ':');
2410 while (isspace(*s)) s++;
2412 /* Loop for multiple addresses in the header, enabling group syntax. Note
2413 that we have to reset this after the header has been scanned. */
2415 parse_allow_group = TRUE;
2419 uschar *ss = parse_find_address_end(s, FALSE);
2420 uschar *recipient, *errmess;
2421 int terminator = *ss;
2422 int start, end, domain;
2424 /* Temporarily terminate the string at this point, and extract the
2425 operative address within, allowing group syntax. */
2428 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2431 /* Permit an unqualified address only if the message is local, or if the
2432 sending host is configured to be permitted to send them. */
2434 if (recipient != NULL && domain == 0)
2436 if (h->type == htype_from || h->type == htype_sender)
2438 if (!allow_unqualified_sender) recipient = NULL;
2442 if (!allow_unqualified_recipient) recipient = NULL;
2444 if (recipient == NULL) errmess = US"unqualified address not permitted";
2447 /* It's an error if no address could be extracted, except for the special
2448 case of an empty address. */
2450 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2452 uschar *verb = US"is";
2457 /* Arrange not to include any white space at the end in the
2458 error message or the header name. */
2460 while (t > s && isspace(t[-1])) t--;
2461 while (tt > h->text && isspace(tt[-1])) tt--;
2463 /* Add the address that failed to the error message, since in a
2464 header with very many addresses it is sometimes hard to spot
2465 which one is at fault. However, limit the amount of address to
2466 quote - cases have been seen where, for example, a missing double
2467 quote in a humungous To: header creates an "address" that is longer
2468 than string_sprintf can handle. */
2477 /* deconst cast ok as we're passing a non-const to string_printing() */
2478 *msgptr = US string_printing(
2479 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2480 errmess, tt - h->text, h->text, verb, len, s));
2483 break; /* Out of address loop */
2486 /* Advance to the next address */
2488 s = ss + (terminator? 1:0);
2489 while (isspace(*s)) s++;
2490 } /* Next address */
2492 parse_allow_group = FALSE;
2493 parse_found_group = FALSE;
2494 } /* Next header unless yield has been set FALSE */
2500 /*************************************************
2501 * Check header names for 8-bit characters *
2502 *************************************************/
2504 /* This function checks for invalid charcters in header names. See
2505 RFC 5322, 2.2. and RFC 6532, 3.
2508 msgptr where to put an error message
2515 verify_check_header_names_ascii(uschar **msgptr)
2520 for (h = header_list; h != NULL; h = h->next)
2522 colon = Ustrchr(h->text, ':');
2523 for(s = h->text; s < colon; s++)
2525 if ((*s < 33) || (*s > 126))
2527 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2528 colon - h->text, h->text);
2536 /*************************************************
2537 * Check for blind recipients *
2538 *************************************************/
2540 /* This function checks that every (envelope) recipient is mentioned in either
2541 the To: or Cc: header lines, thus detecting blind carbon copies.
2543 There are two ways of scanning that could be used: either scan the header lines
2544 and tick off the recipients, or scan the recipients and check the header lines.
2545 The original proposed patch did the former, but I have chosen to do the latter,
2546 because (a) it requires no memory and (b) will use fewer resources when there
2547 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2550 Returns: OK if there are no blind recipients
2551 FAIL if there is at least one blind recipient
2555 verify_check_notblind(void)
2558 for (i = 0; i < recipients_count; i++)
2562 uschar *address = recipients_list[i].address;
2564 for (h = header_list; !found && h != NULL; h = h->next)
2568 if (h->type != htype_to && h->type != htype_cc) continue;
2570 colon = Ustrchr(h->text, ':');
2572 while (isspace(*s)) s++;
2574 /* Loop for multiple addresses in the header, enabling group syntax. Note
2575 that we have to reset this after the header has been scanned. */
2577 parse_allow_group = TRUE;
2581 uschar *ss = parse_find_address_end(s, FALSE);
2582 uschar *recipient,*errmess;
2583 int terminator = *ss;
2584 int start, end, domain;
2586 /* Temporarily terminate the string at this point, and extract the
2587 operative address within, allowing group syntax. */
2590 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2593 /* If we found a valid recipient that has a domain, compare it with the
2594 envelope recipient. Local parts are compared case-sensitively, domains
2595 case-insensitively. By comparing from the start with length "domain", we
2596 include the "@" at the end, which ensures that we are comparing the whole
2597 local part of each address. */
2599 if (recipient != NULL && domain != 0)
2601 found = Ustrncmp(recipient, address, domain) == 0 &&
2602 strcmpic(recipient + domain, address + domain) == 0;
2606 /* Advance to the next address */
2608 s = ss + (terminator? 1:0);
2609 while (isspace(*s)) s++;
2610 } /* Next address */
2612 parse_allow_group = FALSE;
2613 parse_found_group = FALSE;
2614 } /* Next header (if found is false) */
2616 if (!found) return FAIL;
2617 } /* Next recipient */
2624 /*************************************************
2625 * Find if verified sender *
2626 *************************************************/
2628 /* Usually, just a single address is verified as the sender of the message.
2629 However, Exim can be made to verify other addresses as well (often related in
2630 some way), and this is useful in some environments. There may therefore be a
2631 chain of such addresses that have previously been tested. This function finds
2632 whether a given address is on the chain.
2634 Arguments: the address to be verified
2635 Returns: pointer to an address item, or NULL
2639 verify_checked_sender(uschar *sender)
2642 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2643 if (Ustrcmp(sender, addr->address) == 0) break;
2651 /*************************************************
2652 * Get valid header address *
2653 *************************************************/
2655 /* Scan the originator headers of the message, looking for an address that
2656 verifies successfully. RFC 822 says:
2658 o The "Sender" field mailbox should be sent notices of
2659 any problems in transport or delivery of the original
2660 messages. If there is no "Sender" field, then the
2661 "From" field mailbox should be used.
2663 o If the "Reply-To" field exists, then the reply should
2664 go to the addresses indicated in that field and not to
2665 the address(es) indicated in the "From" field.
2667 So we check a Sender field if there is one, else a Reply_to field, else a From
2668 field. As some strange messages may have more than one of these fields,
2669 especially if they are resent- fields, check all of them if there is more than
2673 user_msgptr points to where to put a user error message
2674 log_msgptr points to where to put a log error message
2675 callout timeout for callout check (passed to verify_address())
2676 callout_overall overall callout timeout (ditto)
2677 callout_connect connect callout timeout (ditto)
2678 se_mailfrom mailfrom for verify; NULL => ""
2679 pm_mailfrom sender for pm callout check (passed to verify_address())
2680 options callout options (passed to verify_address())
2681 verrno where to put the address basic_errno
2683 If log_msgptr is set to something without setting user_msgptr, the caller
2684 normally uses log_msgptr for both things.
2686 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2687 FAIL is given if no appropriate headers are found
2691 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2692 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2693 uschar *pm_mailfrom, int options, int *verrno)
2695 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2700 for (i = 0; i < 3 && !done; i++)
2703 for (h = header_list; h != NULL && !done; h = h->next)
2705 int terminator, new_ok;
2706 uschar *s, *ss, *endname;
2708 if (h->type != header_types[i]) continue;
2709 s = endname = Ustrchr(h->text, ':') + 1;
2711 /* Scan the addresses in the header, enabling group syntax. Note that we
2712 have to reset this after the header has been scanned. */
2714 parse_allow_group = TRUE;
2718 address_item *vaddr;
2720 while (isspace(*s) || *s == ',') s++;
2721 if (*s == 0) break; /* End of header */
2723 ss = parse_find_address_end(s, FALSE);
2725 /* The terminator is a comma or end of header, but there may be white
2726 space preceding it (including newline for the last address). Move back
2727 past any white space so we can check against any cached envelope sender
2728 address verifications. */
2730 while (isspace(ss[-1])) ss--;
2734 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2735 (int)(endname - h->text), h->text, s);
2737 /* See if we have already verified this address as an envelope sender,
2738 and if so, use the previous answer. */
2740 vaddr = verify_checked_sender(s);
2742 if (vaddr != NULL && /* Previously checked */
2743 (callout <= 0 || /* No callout needed; OR */
2744 vaddr->special_action > 256)) /* Callout was done */
2746 new_ok = vaddr->special_action & 255;
2747 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2748 *ss = terminator; /* Restore shortened string */
2751 /* Otherwise we run the verification now. We must restore the shortened
2752 string before running the verification, so the headers are correct, in
2753 case there is any rewriting. */
2757 int start, end, domain;
2758 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2763 /* If we found an empty address, just carry on with the next one, but
2764 kill the message. */
2766 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2773 /* If verification failed because of a syntax error, fail this
2774 function, and ensure that the failing address gets added to the error
2777 if (address == NULL)
2780 while (ss > s && isspace(ss[-1])) ss--;
2781 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2782 "scanning for sender: %s in \"%.*s\"",
2783 endname - h->text, h->text, *log_msgptr, ss - s, s);
2789 /* Else go ahead with the sender verification. But it isn't *the*
2790 sender of the message, so set vopt_fake_sender to stop sender_address
2791 being replaced after rewriting or qualification. */
2795 vaddr = deliver_make_addr(address, FALSE);
2796 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2797 callout, callout_overall, callout_connect, se_mailfrom,
2802 /* We now have the result, either newly found, or cached. If we are
2803 giving out error details, set a specific user error. This means that the
2804 last of these will be returned to the user if all three fail. We do not
2805 set a log message - the generic one below will be used. */
2809 *verrno = vaddr->basic_errno;
2810 if (smtp_return_error_details)
2812 *user_msgptr = string_sprintf("Rejected after DATA: "
2813 "could not verify \"%.*s\" header address\n%s: %s",
2814 endname - h->text, h->text, vaddr->address, vaddr->message);
2818 /* Success or defer */
2827 if (new_ok == DEFER) yield = DEFER;
2829 /* Move on to any more addresses in the header */
2832 } /* Next address */
2834 parse_allow_group = FALSE;
2835 parse_found_group = FALSE;
2836 } /* Next header, unless done */
2837 } /* Next header type unless done */
2839 if (yield == FAIL && *log_msgptr == NULL)
2840 *log_msgptr = US"there is no valid sender in any header line";
2842 if (yield == DEFER && *log_msgptr == NULL)
2843 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2851 /*************************************************
2852 * Get RFC 1413 identification *
2853 *************************************************/
2855 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2856 the timeout is set to zero, then the query is not done. There may also be lists
2857 of hosts and nets which are exempt. To guard against malefactors sending
2858 non-printing characters which could, for example, disrupt a message's headers,
2859 make sure the string consists of printing characters only.
2862 port the port to connect to; usually this is IDENT_PORT (113), but when
2863 running in the test harness with -bh a different value is used.
2867 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2871 verify_get_ident(int port)
2873 int sock, host_af, qlen;
2874 int received_sender_port, received_interface_port, n;
2876 uschar buffer[2048];
2878 /* Default is no ident. Check whether we want to do an ident check for this
2881 sender_ident = NULL;
2882 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2885 DEBUG(D_ident) debug_printf("doing ident callback\n");
2887 /* Set up a connection to the ident port of the remote host. Bind the local end
2888 to the incoming interface address. If the sender host address is an IPv6
2889 address, the incoming interface address will also be IPv6. */
2891 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2892 sock = ip_socket(SOCK_STREAM, host_af);
2893 if (sock < 0) return;
2895 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2897 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2902 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2905 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2907 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2908 sender_host_address);
2912 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2913 sender_host_address, strerror(errno));
2918 /* Construct and send the query. */
2920 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2921 qlen = Ustrlen(buffer);
2922 if (send(sock, buffer, qlen, 0) < 0)
2924 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2928 /* Read a response line. We put it into the rest of the buffer, using several
2929 recv() calls if necessary. */
2937 int size = sizeof(buffer) - (p - buffer);
2939 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2940 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2941 if (count <= 0) goto END_OFF; /* Read error or EOF */
2943 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2944 generous, and accept a plain \n terminator as well. The only illegal
2947 for (pp = p; pp < p + count; pp++)
2949 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2952 if (pp[-1] == '\r') pp--;
2954 goto GOT_DATA; /* Break out of both loops */
2958 /* Reached the end of the data without finding \n. Let the loop continue to
2959 read some more, if there is room. */
2966 /* We have received a line of data. Check it carefully. It must start with the
2967 same two port numbers that we sent, followed by data as defined by the RFC. For
2970 12345 , 25 : USERID : UNIX :root
2972 However, the amount of white space may be different to what we sent. In the
2973 "osname" field there may be several sub-fields, comma separated. The data we
2974 actually want to save follows the third colon. Some systems put leading spaces
2975 in it - we discard those. */
2977 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2978 &received_interface_port, &n) != 2 ||
2979 received_sender_port != sender_host_port ||
2980 received_interface_port != interface_port)
2983 p = buffer + qlen + n;
2984 while(isspace(*p)) p++;
2985 if (*p++ != ':') goto END_OFF;
2986 while(isspace(*p)) p++;
2987 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2989 while(isspace(*p)) p++;
2990 if (*p++ != ':') goto END_OFF;
2991 while (*p != 0 && *p != ':') p++;
2992 if (*p++ == 0) goto END_OFF;
2993 while(isspace(*p)) p++;
2994 if (*p == 0) goto END_OFF;
2996 /* The rest of the line is the data we want. We turn it into printing
2997 characters when we save it, so that it cannot mess up the format of any logging
2998 or Received: lines into which it gets inserted. We keep a maximum of 127
2999 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
3001 sender_ident = US string_printing(string_copyn(p, 127));
3002 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
3012 /*************************************************
3013 * Match host to a single host-list item *
3014 *************************************************/
3016 /* This function compares a host (name or address) against a single item
3017 from a host list. The host name gets looked up if it is needed and is not
3018 already known. The function is called from verify_check_this_host() via
3019 match_check_list(), which is why most of its arguments are in a single block.
3022 arg the argument block (see below)
3023 ss the host-list item
3024 valueptr where to pass back looked up data, or NULL
3025 error for error message when returning ERROR
3028 host_name (a) the host name, or
3029 (b) NULL, implying use sender_host_name and
3030 sender_host_aliases, looking them up if required, or
3031 (c) the empty string, meaning that only IP address matches
3033 host_address the host address
3034 host_ipv4 the IPv4 address taken from an IPv6 one
3038 DEFER lookup deferred
3039 ERROR (a) failed to find the host name or IP address, or
3040 (b) unknown lookup type specified, or
3041 (c) host name encountered when only IP addresses are
3046 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
3048 check_host_block *cb = (check_host_block *)arg;
3051 BOOL iplookup = FALSE;
3052 BOOL isquery = FALSE;
3053 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
3058 /* Optimize for the special case when the pattern is "*". */
3060 if (*ss == '*' && ss[1] == 0) return OK;
3062 /* If the pattern is empty, it matches only in the case when there is no host -
3063 this can occur in ACL checking for SMTP input using the -bs option. In this
3064 situation, the host address is the empty string. */
3066 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
3067 if (*ss == 0) return FAIL;
3069 /* If the pattern is precisely "@" then match against the primary host name,
3070 provided that host name matching is permitted; if it's "@[]" match against the
3071 local host's IP addresses. */
3077 if (isiponly) return ERROR;
3078 ss = primary_hostname;
3080 else if (Ustrcmp(ss, "@[]") == 0)
3082 ip_address_item *ip;
3083 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
3084 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
3089 /* If the pattern is an IP address, optionally followed by a bitmask count, do
3090 a (possibly masked) comparision with the current IP address. */
3092 if (string_is_ip_address(ss, &maskoffset) != 0)
3093 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
3095 /* The pattern is not an IP address. A common error that people make is to omit
3096 one component of an IPv4 address, either by accident, or believing that, for
3097 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,
3098 which it isn't. (Those applications that do accept 1.2.3 as an IP address
3099 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
3100 ancient specification.) To aid in debugging these cases, we give a specific
3101 error if the pattern contains only digits and dots or contains a slash preceded
3102 only by digits and dots (a slash at the start indicates a file name and of
3103 course slashes may be present in lookups, but not preceded only by digits and
3106 for (t = ss; isdigit(*t) || *t == '.'; t++);
3107 if (*t == 0 || (*t == '/' && t != ss))
3109 *error = US"malformed IPv4 address or address mask";
3113 /* See if there is a semicolon in the pattern */
3115 semicolon = Ustrchr(ss, ';');
3117 /* If we are doing an IP address only match, then all lookups must be IP
3118 address lookups, even if there is no "net-". */
3122 iplookup = semicolon != NULL;
3125 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
3126 a lookup on a masked IP network, in textual form. We obey this code even if we
3127 have already set iplookup, so as to skip over the "net-" prefix and to set the
3128 mask length. The net- stuff really only applies to single-key lookups where the
3129 key is implicit. For query-style lookups the key is specified in the query.
3130 From release 4.30, the use of net- for query style is no longer needed, but we
3131 retain it for backward compatibility. */
3133 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
3136 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
3137 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
3138 iplookup = (*t++ == '-');
3142 /* Do the IP address lookup if that is indeed what we have */
3150 uschar *filename, *key, *result;
3153 /* Find the search type */
3155 search_type = search_findtype(t, semicolon - t);
3157 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3158 search_error_message);
3160 /* Adjust parameters for the type of lookup. For a query-style lookup, there
3161 is no file name, and the "key" is just the query. For query-style with a file
3162 name, we have to fish the file off the start of the query. For a single-key
3163 lookup, the key is the current IP address, masked appropriately, and
3164 reconverted to text form, with the mask appended. For IPv6 addresses, specify
3165 dot separators instead of colons, except when the lookup type is "iplsearch".
3168 if (mac_islookup(search_type, lookup_absfilequery))
3170 filename = semicolon + 1;
3172 while (*key != 0 && !isspace(*key)) key++;
3173 filename = string_copyn(filename, key - filename);
3174 while (isspace(*key)) key++;
3176 else if (mac_islookup(search_type, lookup_querystyle))
3179 key = semicolon + 1;
3181 else /* Single-key style */
3183 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3185 insize = host_aton(cb->host_address, incoming);
3186 host_mask(insize, incoming, mlen);
3187 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3189 filename = semicolon + 1;
3192 /* Now do the actual lookup; note that there is no search_close() because
3193 of the caching arrangements. */
3195 handle = search_open(filename, search_type, 0, NULL, NULL);
3196 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3197 search_error_message);
3198 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3199 if (valueptr != NULL) *valueptr = result;
3200 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3203 /* The pattern is not an IP address or network reference of any kind. That is,
3204 it is a host name pattern. If this is an IP only match, there's an error in the
3209 *error = US"cannot match host name in match_ip list";
3213 /* Check the characters of the pattern to see if they comprise only letters,
3214 digits, full stops, and hyphens (the constituents of domain names). Allow
3215 underscores, as they are all too commonly found. Sigh. Also, if
3216 allow_utf8_domains is set, allow top-bit characters. */
3218 for (t = ss; *t != 0; t++)
3219 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3220 (!allow_utf8_domains || *t < 128)) break;
3222 /* If the pattern is a complete domain name, with no fancy characters, look up
3223 its IP address and match against that. Note that a multi-homed host will add
3224 items to the chain. */
3235 /* Using byname rather than bydns here means we cannot determine dnssec
3236 status. On the other hand it is unclear how that could be either
3237 propagated up or enforced. */
3239 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3240 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3243 for (hh = &h; hh != NULL; hh = hh->next)
3245 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3249 if (rc == HOST_FIND_AGAIN) return DEFER;
3250 *error = string_sprintf("failed to find IP address for %s", ss);
3254 /* Almost all subsequent comparisons require the host name, and can be done
3255 using the general string matching function. When this function is called for
3256 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3257 must use sender_host_name and its aliases, looking them up if necessary. */
3259 if (cb->host_name != NULL) /* Explicit host name given */
3260 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3263 /* Host name not given; in principle we need the sender host name and its
3264 aliases. However, for query-style lookups, we do not need the name if the
3265 query does not contain $sender_host_name. From release 4.23, a reference to
3266 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3269 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3271 const uschar *affix;
3272 int partial, affixlen, starflags, id;
3275 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3278 if (id < 0) /* Unknown lookup type */
3280 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3281 search_error_message, ss);
3284 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3289 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3292 case DEFER: return DEFER;
3293 default: return FAIL;
3297 /* Not a query-style lookup; must ensure the host name is present, and then we
3298 do a check on the name and all its aliases. */
3300 if (sender_host_name == NULL)
3302 HDEBUG(D_host_lookup)
3303 debug_printf("sender host name required, to match against %s\n", ss);
3304 if (host_lookup_failed || host_name_lookup() != OK)
3306 *error = string_sprintf("failed to find host name for %s",
3307 sender_host_address);;
3310 host_build_sender_fullhost();
3313 /* Match on the sender host name, using the general matching function */
3315 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3319 case DEFER: return DEFER;
3322 /* If there are aliases, try matching on them. */
3324 aliases = sender_host_aliases;
3325 while (*aliases != NULL)
3327 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3330 case DEFER: return DEFER;
3339 /*************************************************
3340 * Check a specific host matches a host list *
3341 *************************************************/
3343 /* This function is passed a host list containing items in a number of
3344 different formats and the identity of a host. Its job is to determine whether
3345 the given host is in the set of hosts defined by the list. The host name is
3346 passed as a pointer so that it can be looked up if needed and not already
3347 known. This is commonly the case when called from verify_check_host() to check
3348 an incoming connection. When called from elsewhere the host name should usually
3351 This function is now just a front end to match_check_list(), which runs common
3352 code for scanning a list. We pass it the check_host() function to perform a
3356 listptr pointer to the host list
3357 cache_bits pointer to cache for named lists, or NULL
3358 host_name the host name or NULL, implying use sender_host_name and
3359 sender_host_aliases, looking them up if required
3360 host_address the IP address
3361 valueptr if not NULL, data from a lookup is passed back here
3363 Returns: OK if the host is in the defined set
3364 FAIL if the host is not in the defined set,
3365 DEFER if a data lookup deferred (not a host lookup)
3367 If the host name was needed in order to make a comparison, and could not be
3368 determined from the IP address, the result is FAIL unless the item
3369 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3372 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3373 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3376 unsigned int *local_cache_bits = cache_bits;
3377 const uschar *save_host_address = deliver_host_address;
3378 check_host_block cb;
3379 cb.host_name = host_name;
3380 cb.host_address = host_address;
3382 if (valueptr != NULL) *valueptr = NULL;
3384 /* If the host address starts off ::ffff: it is an IPv6 address in
3385 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3388 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3389 host_address + 7 : host_address;
3391 /* During the running of the check, put the IP address into $host_address. In
3392 the case of calls from the smtp transport, it will already be there. However,
3393 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3394 the safe side, any existing setting is preserved, though as I write this
3395 (November 2004) I can't see any cases where it is actually needed. */
3397 deliver_host_address = host_address;
3398 rc = match_check_list(
3399 listptr, /* the list */
3400 0, /* separator character */
3401 &hostlist_anchor, /* anchor pointer */
3402 &local_cache_bits, /* cache pointer */
3403 check_host, /* function for testing */
3404 &cb, /* argument for function */
3405 MCL_HOST, /* type of check */
3406 (host_address == sender_host_address)?
3407 US"host" : host_address, /* text for debugging */
3408 valueptr); /* where to pass back data */
3409 deliver_host_address = save_host_address;
3416 /*************************************************
3417 * Check the given host item matches a list *
3418 *************************************************/
3420 verify_check_given_host(uschar **listptr, host_item *host)
3422 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3425 /*************************************************
3426 * Check the remote host matches a list *
3427 *************************************************/
3429 /* This is a front end to verify_check_this_host(), created because checking
3430 the remote host is a common occurrence. With luck, a good compiler will spot
3431 the tail recursion and optimize it. If there's no host address, this is
3432 command-line SMTP input - check against an empty string for the address.
3435 listptr pointer to the host list
3437 Returns: the yield of verify_check_this_host(),
3438 i.e. OK, FAIL, or DEFER
3442 verify_check_host(uschar **listptr)
3444 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3445 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3452 /*************************************************
3453 * Invert an IP address *
3454 *************************************************/
3456 /* Originally just used for DNS xBL lists, now also used for the
3457 reverse_ip expansion operator.
3460 buffer where to put the answer
3461 address the address to invert
3465 invert_address(uschar *buffer, uschar *address)
3468 uschar *bptr = buffer;
3470 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3471 to the IPv4 part only. */
3473 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3475 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3478 if (host_aton(address, bin) == 1)
3482 for (i = 0; i < 4; i++)
3484 sprintf(CS bptr, "%d.", x & 255);
3485 while (*bptr) bptr++;
3490 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3491 in any DNS black lists, and the format in which they will be looked up is
3492 unknown. This is just a guess. */
3498 for (j = 3; j >= 0; j--)
3501 for (i = 0; i < 8; i++)
3503 sprintf(CS bptr, "%x.", x & 15);
3504 while (*bptr) bptr++;
3511 /* Remove trailing period -- this is needed so that both arbitrary
3512 dnsbl keydomains and inverted addresses may be combined with the
3513 same format string, "%s.%s" */
3520 /*************************************************
3521 * Perform a single dnsbl lookup *
3522 *************************************************/
3524 /* This function is called from verify_check_dnsbl() below. It is also called
3525 recursively from within itself when domain and domain_txt are different
3526 pointers, in order to get the TXT record from the alternate domain.
3529 domain the outer dnsbl domain
3530 domain_txt alternate domain to lookup TXT record on success; when the
3531 same domain is to be used, domain_txt == domain (that is,
3532 the pointers must be identical, not just the text)
3533 keydomain the current keydomain (for debug message)
3534 prepend subdomain to lookup (like keydomain, but
3535 reversed if IP address)
3536 iplist the list of matching IP addresses, or NULL for "any"
3537 bitmask true if bitmask matching is wanted
3538 match_type condition for 'succeed' result
3539 0 => Any RR in iplist (=)
3540 1 => No RR in iplist (!=)
3541 2 => All RRs in iplist (==)
3542 3 => Some RRs not in iplist (!==)
3543 the two bits are defined as MT_NOT and MT_ALL
3544 defer_return what to return for a defer
3546 Returns: OK if lookup succeeded
3551 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3552 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3558 dnsbl_cache_block *cb;
3559 int old_pool = store_pool;
3560 uschar query[256]; /* DNS domain max length */
3562 /* Construct the specific query domainname */
3564 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3566 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3567 "(ignored): %s...", query);
3571 /* Look for this query in the cache. */
3573 if ( (t = tree_search(dnsbl_cache, query))
3574 && (cb = t->data.ptr)->expiry > time(NULL)
3577 /* Previous lookup was cached */
3580 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3583 /* If not cached from a previous lookup, we must do a DNS lookup, and
3584 cache the result in permanent memory. */
3590 store_pool = POOL_PERM;
3594 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3598 { /* Set up a tree entry to cache the lookup */
3599 t = store_get(sizeof(tree_node) + Ustrlen(query));
3600 Ustrcpy(t->name, query);
3601 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3602 (void)tree_insertnode(&dnsbl_cache, t);
3605 /* Do the DNS loopup . */
3607 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3608 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3609 cb->text_set = FALSE;
3613 /* If the lookup succeeded, cache the RHS address. The code allows for
3614 more than one address - this was for complete generality and the possible
3615 use of A6 records. However, A6 records have been reduced to experimental
3616 status (August 2001) and may die out. So they may never get used at all,
3617 let alone in dnsbl records. However, leave the code here, just in case.
3619 Quite apart from one A6 RR generating multiple addresses, there are DNS
3620 lists that return more than one A record, so we must handle multiple
3621 addresses generated in that way as well.
3623 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3624 or some suitably far-future time if none were found. */
3626 if (cb->rc == DNS_SUCCEED)
3629 dns_address **addrp = &(cb->rhs);
3630 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3632 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3634 if (rr->type == T_A)
3636 dns_address *da = dns_address_from_rr(&dnsa, rr);
3640 while (da->next != NULL) da = da->next;
3641 addrp = &(da->next);
3642 if (ttl > rr->ttl) ttl = rr->ttl;
3647 /* If we didn't find any A records, change the return code. This can
3648 happen when there is a CNAME record but there are no A records for what
3651 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3654 cb->expiry = time(NULL)+ttl;
3655 store_pool = old_pool;
3658 /* We now have the result of the DNS lookup, either newly done, or cached
3659 from a previous call. If the lookup succeeded, check against the address
3660 list if there is one. This may be a positive equality list (introduced by
3661 "="), a negative equality list (introduced by "!="), a positive bitmask
3662 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3664 if (cb->rc == DNS_SUCCEED)
3666 dns_address *da = NULL;
3667 uschar *addlist = cb->rhs->address;
3669 /* For A and AAAA records, there may be multiple addresses from multiple
3670 records. For A6 records (currently not expected to be used) there may be
3671 multiple addresses from a single record. */
3673 for (da = cb->rhs->next; da != NULL; da = da->next)
3674 addlist = string_sprintf("%s, %s", addlist, da->address);
3676 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3679 /* Address list check; this can be either for equality, or via a bitmask.
3680 In the latter case, all the bits must match. */
3684 for (da = cb->rhs; da != NULL; da = da->next)
3688 const uschar *ptr = iplist;
3691 /* Handle exact matching */
3695 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3697 if (Ustrcmp(CS da->address, ip) == 0) break;
3701 /* Handle bitmask matching */
3708 /* At present, all known DNS blocking lists use A records, with
3709 IPv4 addresses on the RHS encoding the information they return. I
3710 wonder if this will linger on as the last vestige of IPv4 when IPv6
3711 is ubiquitous? Anyway, for now we use paranoia code to completely
3712 ignore IPv6 addresses. The default mask is 0, which always matches.
3713 We change this only for IPv4 addresses in the list. */
3715 if (host_aton(da->address, address) == 1) mask = address[0];
3717 /* Scan the returned addresses, skipping any that are IPv6 */
3719 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3721 if (host_aton(ip, address) != 1) continue;
3722 if ((address[0] & mask) == address[0]) break;
3728 (a) An IP address in an any ('=') list matched, or
3729 (b) No IP address in an all ('==') list matched
3731 then we're done searching. */
3733 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3736 /* If da == NULL, either
3738 (a) No IP address in an any ('=') list matched, or
3739 (b) An IP address in an all ('==') list didn't match
3741 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3744 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3752 res = US"was no match";
3755 res = US"was an exclude match";
3758 res = US"was an IP address that did not match";
3761 res = US"were no IP addresses that did not match";
3764 debug_printf("=> but we are not accepting this block class because\n");
3765 debug_printf("=> there %s for %s%c%s\n",
3767 ((match_type & MT_ALL) == 0)? "" : "=",
3768 bitmask? '&' : '=', iplist);
3774 /* Either there was no IP list, or the record matched, implying that the
3775 domain is on the list. We now want to find a corresponding TXT record. If an
3776 alternate domain is specified for the TXT record, call this function
3777 recursively to look that up; this has the side effect of re-checking that
3778 there is indeed an A record at the alternate domain. */
3780 if (domain_txt != domain)
3781 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3782 FALSE, match_type, defer_return);
3784 /* If there is no alternate domain, look up a TXT record in the main domain
3785 if it has not previously been cached. */
3789 cb->text_set = TRUE;
3790 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3793 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3795 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3796 if (rr->type == T_TXT) break;
3799 int len = (rr->data)[0];
3800 if (len > 511) len = 127;
3801 store_pool = POOL_PERM;
3802 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3803 store_pool = old_pool;
3808 dnslist_value = addlist;
3809 dnslist_text = cb->text;
3813 /* There was a problem with the DNS lookup */
3815 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3817 log_write(L_dnslist_defer, LOG_MAIN,
3818 "DNS list lookup defer (probably timeout) for %s: %s", query,
3819 (defer_return == OK)? US"assumed in list" :
3820 (defer_return == FAIL)? US"assumed not in list" :
3821 US"returned DEFER");
3822 return defer_return;
3825 /* No entry was found in the DNS; continue for next domain */
3829 debug_printf("DNS lookup for %s failed\n", query);
3830 debug_printf("=> that means %s is not listed at %s\n",
3840 /*************************************************
3841 * Check host against DNS black lists *
3842 *************************************************/
3844 /* This function runs checks against a list of DNS black lists, until one
3845 matches. Each item on the list can be of the form
3847 domain=ip-address/key
3849 The domain is the right-most domain that is used for the query, for example,
3850 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3851 if the DNS lookup returns a matching IP address. Several addresses may be
3852 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3854 If no key is given, what is looked up in the domain is the inverted IP address
3855 of the current client host. If a key is given, it is used to construct the
3856 domain for the lookup. For example:
3858 dsn.rfc-ignorant.org/$sender_address_domain
3860 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3861 then we check for a TXT record for an error message, and if found, save its
3862 value in $dnslist_text. We also cache everything in a tree, to optimize
3865 The TXT record is normally looked up in the same domain as the A record, but
3866 when many lists are combined in a single DNS domain, this will not be a very
3867 specific message. It is possible to specify a different domain for looking up
3868 TXT records; this is given before the main domain, comma-separated. For
3871 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3872 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3874 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3876 Note: an address for testing RBL is 192.203.178.39
3877 Note: an address for testing DUL is 192.203.178.4
3878 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3882 listptr the domain/address/data list
3883 log_msgptr log message on error
3885 Returns: OK successful lookup (i.e. the address is on the list), or
3886 lookup deferred after +include_unknown
3887 FAIL name not found, or no data found for the given type, or
3888 lookup deferred after +exclude_unknown (default)
3889 DEFER lookup failure, if +defer_unknown was set
3893 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3896 int defer_return = FAIL;
3897 const uschar *list = *listptr;
3900 uschar buffer[1024];
3901 uschar revadd[128]; /* Long enough for IPv6 address */
3903 /* Indicate that the inverted IP address is not yet set up */
3907 /* In case this is the first time the DNS resolver is being used. */
3909 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3911 /* Loop through all the domains supplied, until something matches */
3913 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3916 BOOL bitmask = FALSE;
3923 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3925 /* Deal with special values that change the behaviour on defer */
3927 if (domain[0] == '+')
3929 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3930 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3931 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3933 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3938 /* See if there's explicit data to be looked up */
3940 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3942 /* See if there's a list of addresses supplied after the domain name. This is
3943 introduced by an = or a & character; if preceded by = we require all matches
3944 and if preceded by ! we invert the result. */
3946 if (!(iplist = Ustrchr(domain, '=')))
3949 iplist = Ustrchr(domain, '&');
3952 if (iplist) /* Found either = or & */
3954 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3956 match_type |= MT_NOT;
3960 *iplist++ = 0; /* Terminate domain, move on */
3962 /* If we found = (bitmask == FALSE), check for == or =& */
3964 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3966 bitmask = *iplist++ == '&';
3967 match_type |= MT_ALL;
3972 /* If there is a comma in the domain, it indicates that a second domain for
3973 looking up TXT records is provided, before the main domain. Otherwise we must
3974 set domain_txt == domain. */
3976 domain_txt = domain;
3977 comma = Ustrchr(domain, ',');
3984 /* Check that what we have left is a sensible domain name. There is no reason
3985 why these domains should in fact use the same syntax as hosts and email
3986 domains, but in practice they seem to. However, there is little point in
3987 actually causing an error here, because that would no doubt hold up incoming
3988 mail. Instead, I'll just log it. */
3990 for (s = domain; *s != 0; s++)
3992 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3994 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3995 "strange characters - is this right?", domain);
4000 /* Check the alternate domain if present */
4002 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
4004 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
4006 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
4007 "strange characters - is this right?", domain_txt);
4012 /* If there is no key string, construct the query by adding the domain name
4013 onto the inverted host address, and perform a single DNS lookup. */
4017 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
4019 *log_msgptr = string_sprintf
4020 ("cannot test auto-keyed dnslists condition in %s ACL",
4021 acl_wherenames[where]);
4024 if (sender_host_address == NULL) return FAIL; /* can never match */
4025 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
4026 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
4027 iplist, bitmask, match_type, defer_return);
4030 dnslist_domain = string_copy(domain_txt);
4031 dnslist_matched = string_copy(sender_host_address);
4032 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4033 sender_host_address, dnslist_domain);
4035 if (rc != FAIL) return rc; /* OK or DEFER */
4038 /* If there is a key string, it can be a list of domains or IP addresses to
4039 be concatenated with the main domain. */
4046 uschar keybuffer[256];
4047 uschar keyrevadd[128];
4049 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
4050 sizeof(keybuffer))) != NULL)
4052 uschar *prepend = keydomain;
4054 if (string_is_ip_address(keydomain, NULL) != 0)
4056 invert_address(keyrevadd, keydomain);
4057 prepend = keyrevadd;
4060 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
4061 bitmask, match_type, defer_return);
4065 dnslist_domain = string_copy(domain_txt);
4066 dnslist_matched = string_copy(keydomain);
4067 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4068 keydomain, dnslist_domain);
4072 /* If the lookup deferred, remember this fact. We keep trying the rest
4073 of the list to see if we get a useful result, and if we don't, we return
4074 DEFER at the end. */
4076 if (rc == DEFER) defer = TRUE;
4077 } /* continue with next keystring domain/address */
4079 if (defer) return DEFER;
4081 } /* continue with next dnsdb outer domain */
4088 /* End of verify.c */