1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2014 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
21 /* Structure for caching DNSBL lookups */
23 typedef struct dnsbl_cache_block {
31 /* Anchor for DNSBL cache */
33 static tree_node *dnsbl_cache = NULL;
36 /* Bits for match_type in one_check_dnsbl() */
41 static uschar cutthrough_response(char, uschar **);
44 /*************************************************
45 * Retrieve a callout cache record *
46 *************************************************/
48 /* If a record exists, check whether it has expired.
51 dbm_file an open hints file
53 type "address" or "domain"
54 positive_expire expire time for positive records
55 negative_expire expire time for negative records
57 Returns: the cache record if a non-expired one exists, else NULL
60 static dbdata_callout_cache *
61 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
62 int positive_expire, int negative_expire)
67 dbdata_callout_cache *cache_record;
69 cache_record = dbfn_read_with_length(dbm_file, key, &length);
71 if (cache_record == NULL)
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
85 if (now - cache_record->time_stamp > expire)
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
99 if (length == sizeof(dbdata_callout_cache_obs))
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
120 /*************************************************
121 * Do callout verification for an address *
122 *************************************************/
124 /* This function is called from verify_address() when the address has routed to
125 a host list, and a callout has been requested. Callouts are expensive; that is
126 why a cache is used to improve the efficiency.
129 addr the address that's been routed
130 host_list the list of hosts to try
131 tf the transport feedback block
133 ifstring "interface" option from transport, or NULL
134 portstring "port" option from transport, or NULL
135 protocolstring "protocol" option from transport, or NULL
136 callout the per-command callout timeout
137 callout_overall the overall callout timeout (if < 0 use 4*callout)
138 callout_connect the callout connection timeout (if < 0 use callout)
139 options the verification options - these bits are used:
140 vopt_is_recipient => this is a recipient address
141 vopt_callout_no_cache => don't use callout cache
142 vopt_callout_fullpm => if postmaster check, do full one
143 vopt_callout_random => do the "random" thing
144 vopt_callout_recipsender => use real sender for recipient
145 vopt_callout_recippmaster => use postmaster for recipient
146 se_mailfrom MAIL FROM address for sender verify; NULL => ""
147 pm_mailfrom if non-NULL, do the postmaster check with this sender
149 Returns: OK/FAIL/DEFER
153 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
154 int callout, int callout_overall, int callout_connect, int options,
155 uschar *se_mailfrom, uschar *pm_mailfrom)
157 BOOL is_recipient = (options & vopt_is_recipient) != 0;
158 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
159 BOOL callout_random = (options & vopt_callout_random) != 0;
162 int old_domain_cache_result = ccache_accept;
165 uschar *from_address;
166 uschar *random_local_part = NULL;
167 const uschar *save_deliver_domain = deliver_domain;
168 uschar **failure_ptr = is_recipient?
169 &recipient_verify_failure : &sender_verify_failure;
171 open_db *dbm_file = NULL;
172 dbdata_callout_cache new_domain_record;
173 dbdata_callout_cache_address new_address_record;
175 time_t callout_start_time;
176 #ifdef EXPERIMENTAL_INTERNATIONAL
177 BOOL utf8_offered = FALSE;
180 new_domain_record.result = ccache_unknown;
181 new_domain_record.postmaster_result = ccache_unknown;
182 new_domain_record.random_result = ccache_unknown;
184 memset(&new_address_record, 0, sizeof(new_address_record));
186 /* For a recipient callout, the key used for the address cache record must
187 include the sender address if we are using the real sender in the callout,
188 because that may influence the result of the callout. */
190 address_key = addr->address;
195 if (options & vopt_callout_recipsender)
197 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
198 from_address = sender_address;
200 else if (options & vopt_callout_recippmaster)
202 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
203 qualify_domain_sender);
204 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
208 /* For a sender callout, we must adjust the key if the mailfrom address is not
213 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
214 if (from_address[0] != 0)
215 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
218 /* Open the callout cache database, it it exists, for reading only at this
219 stage, unless caching has been disabled. */
221 if (callout_no_cache)
223 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
225 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
227 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
230 /* If a cache database is available see if we can avoid the need to do an
231 actual callout by making use of previously-obtained data. */
233 if (dbm_file != NULL)
235 dbdata_callout_cache_address *cache_address_record;
236 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
237 addr->domain, US"domain",
238 callout_cache_domain_positive_expire,
239 callout_cache_domain_negative_expire);
241 /* If an unexpired cache record was found for this domain, see if the callout
242 process can be short-circuited. */
244 if (cache_record != NULL)
246 /* In most cases, if an early command (up to and including MAIL FROM:<>)
247 was rejected, there is no point carrying on. The callout fails. However, if
248 we are doing a recipient verification with use_sender or use_postmaster
249 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
250 will be using a non-empty sender. We have to remember this situation so as
251 not to disturb the cached domain value if this whole verification succeeds
252 (we don't want it turning into "accept"). */
254 old_domain_cache_result = cache_record->result;
256 if (cache_record->result == ccache_reject ||
257 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
259 setflag(addr, af_verify_nsfail);
261 debug_printf("callout cache: domain gave initial rejection, or "
262 "does not accept HELO or MAIL FROM:<>\n");
263 setflag(addr, af_verify_nsfail);
264 addr->user_message = US"(result of an earlier callout reused).";
266 *failure_ptr = US"mail";
270 /* If a previous check on a "random" local part was accepted, we assume
271 that the server does not do any checking on local parts. There is therefore
272 no point in doing the callout, because it will always be successful. If a
273 random check previously failed, arrange not to do it again, but preserve
274 the data in the new record. If a random check is required but hasn't been
275 done, skip the remaining cache processing. */
277 if (callout_random) switch(cache_record->random_result)
281 debug_printf("callout cache: domain accepts random addresses\n");
282 goto END_CALLOUT; /* Default yield is OK */
286 debug_printf("callout cache: domain rejects random addresses\n");
287 callout_random = FALSE;
288 new_domain_record.random_result = ccache_reject;
289 new_domain_record.random_stamp = cache_record->random_stamp;
294 debug_printf("callout cache: need to check random address handling "
295 "(not cached or cache expired)\n");
299 /* If a postmaster check is requested, but there was a previous failure,
300 there is again no point in carrying on. If a postmaster check is required,
301 but has not been done before, we are going to have to do a callout, so skip
302 remaining cache processing. */
304 if (pm_mailfrom != NULL)
306 if (cache_record->postmaster_result == ccache_reject)
308 setflag(addr, af_verify_pmfail);
310 debug_printf("callout cache: domain does not accept "
311 "RCPT TO:<postmaster@domain>\n");
313 *failure_ptr = US"postmaster";
314 setflag(addr, af_verify_pmfail);
315 addr->user_message = US"(result of earlier verification reused).";
318 if (cache_record->postmaster_result == ccache_unknown)
321 debug_printf("callout cache: need to check RCPT "
322 "TO:<postmaster@domain> (not cached or cache expired)\n");
326 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
327 postmaster check if the address itself has to be checked. Also ensure
328 that the value in the cache record is preserved (with its old timestamp).
331 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
332 "TO:<postmaster@domain>\n");
334 new_domain_record.postmaster_result = ccache_accept;
335 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
339 /* We can't give a result based on information about the domain. See if there
340 is an unexpired cache record for this specific address (combined with the
341 sender address if we are doing a recipient callout with a non-empty sender).
344 cache_address_record = (dbdata_callout_cache_address *)
345 get_callout_cache_record(dbm_file,
346 address_key, US"address",
347 callout_cache_positive_expire,
348 callout_cache_negative_expire);
350 if (cache_address_record != NULL)
352 if (cache_address_record->result == ccache_accept)
355 debug_printf("callout cache: address record is positive\n");
360 debug_printf("callout cache: address record is negative\n");
361 addr->user_message = US"Previous (cached) callout verification failure";
362 *failure_ptr = US"recipient";
368 /* Close the cache database while we actually do the callout for real. */
371 dbfn_close(dbm_file);
375 if (!addr->transport)
377 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
379 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
380 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
381 addr->transport->name, addr->transport->driver_name);
384 smtp_transport_options_block *ob =
385 (smtp_transport_options_block *)addr->transport->options_block;
387 /* The information wasn't available in the cache, so we have to do a real
388 callout and save the result in the cache for next time, unless no_cache is set,
389 or unless we have a previously cached negative random result. If we are to test
390 with a random local part, ensure that such a local part is available. If not,
391 log the fact, but carry on without randomming. */
393 if (callout_random && callout_random_local_part != NULL)
394 if (!(random_local_part = expand_string(callout_random_local_part)))
395 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
396 "callout_random_local_part: %s", expand_string_message);
398 /* Default the connect and overall callout timeouts if not set, and record the
399 time we are starting so that we can enforce it. */
401 if (callout_overall < 0) callout_overall = 4 * callout;
402 if (callout_connect < 0) callout_connect = callout;
403 callout_start_time = time(NULL);
405 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
406 output because a callout might take some time. When PIPELINING is active and
407 there are many recipients, the total time for doing lots of callouts can add up
408 and cause the client to time out. So in this case we forgo the PIPELINING
411 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
413 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
414 and we are holding a cutthrough conn open, we can just append the rcpt to
415 that conn for verification purposes (and later delivery also). Simplest
416 coding means skipping this whole loop and doing the append separately.
418 We will need to remember it has been appended so that rcpt-acl tail code
419 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
422 /* Can we re-use an open cutthrough connection? */
423 if ( cutthrough.fd >= 0
424 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
425 == vopt_callout_recipsender
426 && !random_local_part
430 if (addr->transport == cutthrough.addr.transport)
431 for (host = host_list; host; host = host->next)
432 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
435 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
438 deliver_host = host->name;
439 deliver_host_address = host->address;
440 deliver_host_port = host->port;
441 deliver_domain = addr->domain;
442 transport_name = addr->transport->name;
444 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
446 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
448 !smtp_get_port(tf->port, addr, &port, US"callout"))
449 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
452 if ( ( interface == cutthrough.interface
454 && cutthrough.interface
455 && Ustrcmp(interface, cutthrough.interface) == 0
457 && port == cutthrough.host.port
462 /* Match! Send the RCPT TO, append the addr, set done */
464 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
465 transport_rcpt_address(addr,
466 (addr->transport == NULL)? FALSE :
467 addr->transport->rcpt_include_affixes)) >= 0 &&
468 cutthrough_response('2', &resp) == '2';
470 /* This would go horribly wrong if a callout fail was ignored by ACL.
471 We punt by abandoning cutthrough on a reject, like the
476 address_item * na = store_get(sizeof(address_item));
477 *na = cutthrough.addr;
478 cutthrough.addr = *addr;
479 cutthrough.addr.host_used = &cutthrough.host;
480 cutthrough.addr.next = na;
486 cancel_cutthrough_connection("recipient rejected");
487 if (errno == ETIMEDOUT)
489 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
494 Ustrcpy(resp, US"connection dropped");
497 string_sprintf("response to \"%s\" from %s [%s] was: %s",
498 big_buffer, host->name, host->address,
499 string_printing(resp));
502 string_sprintf("Callout verification failed:\n%s", resp);
504 /* Hard rejection ends the process */
506 if (resp[0] == '5') /* Address rejected */
517 cancel_cutthrough_connection("incompatible connection");
520 /* Now make connections to the hosts and do real callouts. The list of hosts
521 is passed in as an argument. */
523 for (host = host_list; host != NULL && !done; host = host->next)
525 smtp_inblock inblock;
526 smtp_outblock outblock;
529 BOOL send_quit = TRUE;
530 uschar *active_hostname = smtp_active_hostname;
534 BOOL suppress_tls = FALSE;
535 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
536 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
539 dns_answer tlsa_dnsa;
541 uschar inbuffer[4096];
542 uschar outbuffer[1024];
543 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, NULL, &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 #ifdef EXPERIMENTAL_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 */
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;
735 goto esmtp_retry; /* fallback to HELO */
738 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
740 if (esmtp && !suppress_tls && tls_out.active < 0)
742 if (regex_STARTTLS == NULL) regex_STARTTLS =
743 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
745 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
746 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
753 /* If TLS is available on this connection attempt to
754 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
755 send another EHLO - the server may give a different answer in secure mode. We
756 use a separate buffer for reading the response to STARTTLS so that if it is
757 negative, the original EHLO data is available for subsequent analysis, should
758 the client not be required to use TLS. If the response is bad, copy the buffer
759 for error analysis. */
763 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK
764 && verify_check_given_host(&ob->hosts_verify_avoid_tls, host) != OK
767 uschar buffer2[4096];
769 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
772 /* If there is an I/O error, transmission of this message is deferred. If
773 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
774 false, we also defer. However, if there is a temporary rejection of STARTTLS
775 and tls_tempfail_tryclear is true, or if there is an outright rejection of
776 STARTTLS, we carry on. This means we will try to send the message in clear,
777 unless the host is in hosts_require_tls (tested below). */
779 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
780 ob->command_timeout))
782 if (errno != 0 || buffer2[0] == 0 ||
783 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
785 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
787 goto RESPONSE_FAILED;
791 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
794 int oldtimeout = ob->command_timeout;
798 ob->command_timeout = callout;
799 rc = tls_client_start(inblock.sock, host, addr, addr->transport
800 # ifdef EXPERIMENTAL_DANE
801 , dane ? &tlsa_dnsa : NULL
804 ob->command_timeout = oldtimeout;
806 /* TLS negotiation failed; give an error. Try in clear on a new
807 connection, if the options permit it for this host. */
812 (void)close(inblock.sock);
813 # ifdef EXPERIMENTAL_EVENT
814 (void) event_raise(addr->transport->event_action,
815 US"tcp:close", NULL);
817 # ifdef EXPERIMENTAL_DANE
822 log_write(0, LOG_MAIN, "DANE attempt failed;"
823 " trying CA-root TLS to %s [%s] (not in hosts_require_dane)",
824 host->name, host->address);
831 if ( ob->tls_tempfail_tryclear
833 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
836 log_write(0, LOG_MAIN, "TLS session failure:"
837 " delivering unencrypted to %s [%s] (not in hosts_require_tls)",
838 host->name, host->address);
840 goto tls_retry_connection;
844 /*save_errno = ERRNO_TLSFAILURE;*/
845 /*message = US"failure while setting up TLS session";*/
851 /* TLS session is set up. Copy info for logging. */
852 addr->cipher = tls_out.cipher;
853 addr->peerdn = tls_out.peerdn;
855 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
857 goto smtps_redo_greeting;
859 /* For STARTTLS we need to redo EHLO */
864 /* If the host is required to use a secure channel, ensure that we have one. */
865 if (tls_out.active < 0)
867 # ifdef EXPERIMENTAL_DANE
870 verify_check_given_host(&ob->hosts_require_tls, host) == OK
873 /*save_errno = ERRNO_TLSREQUIRED;*/
874 log_write(0, LOG_MAIN,
875 "H=%s [%s]: a TLS session is required for this host, but %s",
876 host->name, host->address,
877 tls_offered ? "an attempt to start TLS failed"
878 : "the server did not offer TLS support");
883 #endif /*SUPPORT_TLS*/
885 done = TRUE; /* so far so good; have response to HELO */
887 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
889 /* For now, transport_filter by cutthrough-delivery is not supported */
890 /* Need proper integration with the proper transport mechanism. */
891 if (cutthrough.delivery)
893 if (addr->transport->filter_command)
895 cutthrough.delivery = FALSE;
896 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
901 cutthrough.delivery = FALSE;
902 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
911 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
913 /* Failure to accept HELO is cached; this blocks the whole domain for all
914 senders. I/O errors and defer responses are not cached. */
918 *failure_ptr = US"mail"; /* At or before MAIL */
919 if (errno == 0 && responsebuffer[0] == '5')
921 setflag(addr, af_verify_nsfail);
922 new_domain_record.result = ccache_reject;
926 #ifdef EXPERIMENTAL_INTERNATIONAL
927 else if ( addr->prop.utf8_msg
928 && !addr->prop.utf8_downcvt
931 || ( (regex_UTF8 = regex_must_compile(
932 US"\\n250[\\s\\-]SMTPUTF8(\\s|\\n|$)", FALSE, TRUE)),
935 && ( (utf8_offered = pcre_exec(regex_UTF8, NULL,
936 CS responsebuffer, Ustrlen(responsebuffer),
937 0, PCRE_EOPT, NULL, 0) >= 0)
938 || addr->prop.utf8_downcvt_maybe
941 HDEBUG(D_acl|D_v) debug_printf("utf8 required but not offered\n");
942 errno = ERRNO_UTF8_FWD;
943 setflag(addr, af_verify_nsfail);
946 else if ( addr->prop.utf8_msg
947 && (addr->prop.utf8_downcvt || !utf8_offered)
948 && (setflag(addr, af_utf8_downcvt),
949 from_address = string_address_utf8_to_alabel(from_address,
954 errno = ERRNO_EXPANDFAIL;
955 setflag(addr, af_verify_nsfail);
960 /* If we haven't authenticated, but are required to, give up. */
963 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
964 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
966 /* Copy AUTH info for logging */
967 ( (addr->authenticator = client_authenticator),
968 (addr->auth_id = client_authenticated_id),
970 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
971 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
974 ( (addr->auth_sndr = client_authenticated_sender),
976 /* Send the MAIL command */
977 (smtp_write_command(&outblock, FALSE,
978 #ifdef EXPERIMENTAL_INTERNATIONAL
979 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
980 ? "MAIL FROM:<%s>%s SMTPUTF8\r\n"
983 "MAIL FROM:<%s>%s\r\n",
984 from_address, responsebuffer) >= 0)
987 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
990 deliver_host = deliver_host_address = NULL;
991 deliver_domain = save_deliver_domain;
993 /* If the host does not accept MAIL FROM:<>, arrange to cache this
994 information, but again, don't record anything for an I/O error or a defer. Do
995 not cache rejections of MAIL when a non-empty sender has been used, because
996 that blocks the whole domain for all senders. */
1000 *failure_ptr = US"mail"; /* At or before MAIL */
1001 if (errno == 0 && responsebuffer[0] == '5')
1003 setflag(addr, af_verify_nsfail);
1004 if (from_address[0] == 0)
1005 new_domain_record.result = ccache_reject_mfnull;
1009 /* Otherwise, proceed to check a "random" address (if required), then the
1010 given address, and the postmaster address (if required). Between each check,
1011 issue RSET, because some servers accept only one recipient after MAIL
1014 Before doing this, set the result in the domain cache record to "accept",
1015 unless its previous value was ccache_reject_mfnull. In that case, the domain
1016 rejects MAIL FROM:<> and we want to continue to remember that. When that is
1017 the case, we have got here only in the case of a recipient verification with
1018 a non-null sender. */
1022 const uschar * rcpt_domain = addr->domain;
1024 #ifdef EXPERIMENTAL_INTERNATIONAL
1025 uschar * errstr = NULL;
1026 if ( testflag(addr, af_utf8_downcvt)
1027 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
1031 addr->message = errstr;
1032 errno = ERRNO_EXPANDFAIL;
1033 setflag(addr, af_verify_nsfail);
1035 rcpt_domain = US""; /*XXX errorhandling! */
1039 new_domain_record.result =
1040 (old_domain_cache_result == ccache_reject_mfnull)?
1041 ccache_reject_mfnull: ccache_accept;
1043 /* Do the random local part check first */
1045 if (random_local_part != NULL)
1047 uschar randombuffer[1024];
1049 smtp_write_command(&outblock, FALSE,
1050 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
1051 rcpt_domain) >= 0 &&
1052 smtp_read_response(&inblock, randombuffer,
1053 sizeof(randombuffer), '2', callout);
1055 /* Remember when we last did a random test */
1057 new_domain_record.random_stamp = time(NULL);
1059 /* If accepted, we aren't going to do any further tests below. */
1062 new_domain_record.random_result = ccache_accept;
1064 /* Otherwise, cache a real negative response, and get back to the right
1065 state to send RCPT. Unless there's some problem such as a dropped
1066 connection, we expect to succeed, because the commands succeeded above.
1067 However, some servers drop the connection after responding to an
1068 invalid recipient, so on (any) error we drop and remake the connection.
1071 else if (errno == 0)
1073 /* This would be ok for 1st rcpt a cutthrough, but no way to
1074 handle a subsequent. So refuse to support any */
1075 cancel_cutthrough_connection("random-recipient");
1077 if (randombuffer[0] == '5')
1078 new_domain_record.random_result = ccache_reject;
1081 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1082 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1085 smtp_write_command(&outblock, FALSE,
1086 #ifdef EXPERIMENTAL_INTERNATIONAL
1087 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
1088 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
1091 "MAIL FROM:<%s>\r\n",
1092 from_address) >= 0 &&
1093 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1099 debug_printf("problem after random/rset/mfrom; reopen conn\n");
1100 random_local_part = NULL;
1102 tls_close(FALSE, TRUE);
1104 (void)close(inblock.sock);
1105 #ifdef EXPERIMENTAL_EVENT
1106 (void) event_raise(addr->transport->event_action,
1107 US"tcp:close", NULL);
1109 goto tls_retry_connection;
1112 else done = FALSE; /* Some timeout/connection problem */
1113 } /* Random check */
1115 /* If the host is accepting all local parts, as determined by the "random"
1116 check, we don't need to waste time doing any further checking. */
1118 if (new_domain_record.random_result != ccache_accept && done)
1120 /* Get the rcpt_include_affixes flag from the transport if there is one,
1121 but assume FALSE if there is not. */
1123 uschar * rcpt = transport_rcpt_address(addr,
1124 addr->transport ? addr->transport->rcpt_include_affixes : FALSE);
1126 #ifdef EXPERIMENTAL_INTERNATIONAL
1127 /*XXX should the conversion be moved into transport_rcpt_address() ? */
1128 uschar * dummy_errstr = NULL;
1129 if ( testflag(addr, af_utf8_downcvt)
1130 && (rcpt = string_address_utf8_to_alabel(rcpt, &dummy_errstr),
1134 errno = ERRNO_EXPANDFAIL;
1135 *failure_ptr = US"recipient";
1142 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
1144 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1148 new_address_record.result = ccache_accept;
1149 else if (errno == 0 && responsebuffer[0] == '5')
1151 *failure_ptr = US"recipient";
1152 new_address_record.result = ccache_reject;
1155 /* Do postmaster check if requested; if a full check is required, we
1156 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
1158 if (done && pm_mailfrom != NULL)
1160 /* Could possibly shift before main verify, just above, and be ok
1161 for cutthrough. But no way to handle a subsequent rcpt, so just
1163 cancel_cutthrough_connection("postmaster verify");
1164 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
1167 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1168 smtp_read_response(&inblock, responsebuffer,
1169 sizeof(responsebuffer), '2', callout) &&
1171 smtp_write_command(&outblock, FALSE,
1172 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
1173 smtp_read_response(&inblock, responsebuffer,
1174 sizeof(responsebuffer), '2', callout) &&
1176 /* First try using the current domain */
1179 smtp_write_command(&outblock, FALSE,
1180 "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 &&
1181 smtp_read_response(&inblock, responsebuffer,
1182 sizeof(responsebuffer), '2', callout)
1187 /* If that doesn't work, and a full check is requested,
1188 try without the domain. */
1191 (options & vopt_callout_fullpm) != 0 &&
1192 smtp_write_command(&outblock, FALSE,
1193 "RCPT TO:<postmaster>\r\n") >= 0 &&
1194 smtp_read_response(&inblock, responsebuffer,
1195 sizeof(responsebuffer), '2', callout)
1198 /* Sort out the cache record */
1200 new_domain_record.postmaster_stamp = time(NULL);
1203 new_domain_record.postmaster_result = ccache_accept;
1204 else if (errno == 0 && responsebuffer[0] == '5')
1206 *failure_ptr = US"postmaster";
1207 setflag(addr, af_verify_pmfail);
1208 new_domain_record.postmaster_result = ccache_reject;
1211 } /* Random not accepted */
1212 } /* MAIL FROM: accepted */
1214 /* For any failure of the main check, other than a negative response, we just
1215 close the connection and carry on. We can identify a negative response by the
1216 fact that errno is zero. For I/O errors it will be non-zero
1218 Set up different error texts for logging and for sending back to the caller
1219 as an SMTP response. Log in all cases, using a one-line format. For sender
1220 callouts, give a full response to the caller, but for recipient callouts,
1221 don't give the IP address because this may be an internal host whose identity
1222 is not to be widely broadcast. */
1226 if (errno == ETIMEDOUT)
1228 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1231 #ifdef EXPERIMENTAL_INTERNATIONAL
1232 else if (errno == ERRNO_UTF8_FWD)
1234 extern int acl_where; /* src/acl.c */
1236 addr->message = string_sprintf(
1237 "response to \"%s\" from %s [%s] did not include SMTPUTF8",
1238 big_buffer, host->name, host->address);
1239 addr->user_message = acl_where == ACL_WHERE_RCPT
1240 ? US"533 mailbox name not allowed"
1241 : US"550 mailbox unavailable";
1246 else if (errno == 0)
1248 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1251 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1252 big_buffer, host->name, host->address,
1253 string_printing(responsebuffer));
1255 addr->user_message = is_recipient?
1256 string_sprintf("Callout verification failed:\n%s", responsebuffer)
1258 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1259 host->address, big_buffer, responsebuffer);
1261 /* Hard rejection ends the process */
1263 if (responsebuffer[0] == '5') /* Address rejected */
1271 /* End the SMTP conversation and close the connection. */
1273 /* Cutthrough - on a successfull connect and recipient-verify with
1274 use-sender and we are 1st rcpt and have no cutthrough conn so far
1275 here is where we want to leave the conn open */
1276 if ( cutthrough.delivery
1280 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
1281 && !random_local_part
1283 && cutthrough.fd < 0
1287 cutthrough.fd = outblock.sock; /* We assume no buffer in use in the outblock */
1288 cutthrough.nrcpt = 1;
1289 cutthrough.interface = interface;
1290 cutthrough.host = *host;
1291 cutthrough.addr = *addr; /* Save the address_item for later logging */
1292 cutthrough.addr.next = NULL;
1293 cutthrough.addr.host_used = &cutthrough.host;
1295 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1297 ctblock.buffer = ctbuffer;
1298 ctblock.buffersize = sizeof(ctbuffer);
1299 ctblock.ptr = ctbuffer;
1300 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1301 ctblock.sock = cutthrough.fd;
1305 /* Ensure no cutthrough on multiple address verifies */
1306 if (options & vopt_callout_recipsender)
1307 cancel_cutthrough_connection("multiple verify calls");
1308 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1311 tls_close(FALSE, TRUE);
1313 (void)close(inblock.sock);
1314 #ifdef EXPERIMENTAL_EVENT
1315 (void) event_raise(addr->transport->event_action,
1316 US"tcp:close", NULL);
1320 } /* Loop through all hosts, while !done */
1323 /* If we get here with done == TRUE, a successful callout happened, and yield
1324 will be set OK or FAIL according to the response to the RCPT command.
1325 Otherwise, we looped through the hosts but couldn't complete the business.
1326 However, there may be domain-specific information to cache in both cases.
1328 The value of the result field in the new_domain record is ccache_unknown if
1329 there was an error before or with MAIL FROM:, and errno was not zero,
1330 implying some kind of I/O error. We don't want to write the cache in that case.
1331 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1333 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1335 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1338 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1342 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1343 (int)sizeof(dbdata_callout_cache));
1344 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1345 " result=%d postmaster=%d random=%d\n",
1346 new_domain_record.result,
1347 new_domain_record.postmaster_result,
1348 new_domain_record.random_result);
1352 /* If a definite result was obtained for the callout, cache it unless caching
1357 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1359 if (dbm_file == NULL)
1360 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1361 if (dbm_file == NULL)
1363 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1367 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1368 (int)sizeof(dbdata_callout_cache_address));
1369 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1370 (new_address_record.result == ccache_accept)? "positive" : "negative");
1375 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1376 temporary error. If there was only one host, and a response was received, leave
1377 it alone if supplying details. Otherwise, give a generic response. */
1381 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1382 is_recipient? "recipient" : "sender");
1385 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1387 addr->user_message = (!smtp_return_error_details)? dullmsg :
1388 string_sprintf("%s for <%s>.\n"
1389 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1390 "they may be permanently unreachable from this server. In the latter case,\n%s",
1391 dullmsg, addr->address,
1393 "the address will never be accepted."
1395 "you need to change the address or create an MX record for its domain\n"
1396 "if it is supposed to be generally accessible from the Internet.\n"
1397 "Talk to your mail administrator for details.");
1399 /* Force a specific error code */
1401 addr->basic_errno = ERRNO_CALLOUTDEFER;
1404 /* Come here from within the cache-reading code on fast-track exit. */
1407 if (dbm_file != NULL) dbfn_close(dbm_file);
1413 /* Called after recipient-acl to get a cutthrough connection open when
1414 one was requested and a recipient-verify wasn't subsequently done.
1417 open_cutthrough_connection( address_item * addr )
1421 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1422 /* We must use a copy of the address for verification, because it might
1426 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1427 rcpt_count > 1 ? "more" : "start");
1428 (void) verify_address(&addr2, NULL,
1429 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1430 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1432 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1438 /* Send given number of bytes from the buffer */
1440 cutthrough_send(int n)
1442 if(cutthrough.fd < 0)
1447 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1449 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1452 transport_count += n;
1453 ctblock.ptr= ctblock.buffer;
1457 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1464 _cutthrough_puts(uschar * cp, int n)
1468 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1469 if(!cutthrough_send(ctblock.buffersize))
1472 *ctblock.ptr++ = *cp++;
1477 /* Buffered output of counted data block. Return boolean success */
1479 cutthrough_puts(uschar * cp, int n)
1481 if (cutthrough.fd < 0) return TRUE;
1482 if (_cutthrough_puts(cp, n)) return TRUE;
1483 cancel_cutthrough_connection("transmit failed");
1489 _cutthrough_flush_send(void)
1491 int n= ctblock.ptr-ctblock.buffer;
1494 if(!cutthrough_send(n))
1500 /* Send out any bufferred output. Return boolean success. */
1502 cutthrough_flush_send(void)
1504 if (_cutthrough_flush_send()) return TRUE;
1505 cancel_cutthrough_connection("transmit failed");
1511 cutthrough_put_nl(void)
1513 return cutthrough_puts(US"\r\n", 2);
1517 /* Get and check response from cutthrough target */
1519 cutthrough_response(char expect, uschar ** copy)
1521 smtp_inblock inblock;
1522 uschar inbuffer[4096];
1523 uschar responsebuffer[4096];
1525 inblock.buffer = inbuffer;
1526 inblock.buffersize = sizeof(inbuffer);
1527 inblock.ptr = inbuffer;
1528 inblock.ptrend = inbuffer;
1529 inblock.sock = cutthrough.fd;
1530 /* this relies on (inblock.sock == tls_out.active) */
1531 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1532 cancel_cutthrough_connection("target timeout on read");
1537 *copy = cp = string_copy(responsebuffer);
1538 /* Trim the trailing end of line */
1539 cp += Ustrlen(responsebuffer);
1540 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1541 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1544 return responsebuffer[0];
1548 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1550 cutthrough_predata(void)
1552 if(cutthrough.fd < 0)
1555 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1556 cutthrough_puts(US"DATA\r\n", 6);
1557 cutthrough_flush_send();
1559 /* Assume nothing buffered. If it was it gets ignored. */
1560 return cutthrough_response('3', NULL) == '3';
1564 /* fd and use_crlf args only to match write_chunk() */
1566 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1569 while(s && (s2 = Ustrchr(s, '\n')))
1571 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1579 /* Buffered send of headers. Return success boolean. */
1580 /* Expands newlines to wire format (CR,NL). */
1581 /* Also sends header-terminating blank line. */
1583 cutthrough_headers_send(void)
1585 if(cutthrough.fd < 0)
1588 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1589 but having a separate buffered-output function (for now)
1591 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1593 if (!transport_headers_send(&cutthrough.addr, cutthrough.fd,
1594 cutthrough.addr.transport->add_headers,
1595 cutthrough.addr.transport->remove_headers,
1596 &cutthrough_write_chunk, TRUE,
1597 cutthrough.addr.transport->rewrite_rules,
1598 cutthrough.addr.transport->rewrite_existflags))
1601 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1607 close_cutthrough_connection(const char * why)
1609 if(cutthrough.fd >= 0)
1611 /* We could be sending this after a bunch of data, but that is ok as
1612 the only way to cancel the transfer in dataphase is to drop the tcp
1613 conn before the final dot.
1615 ctblock.ptr = ctbuffer;
1616 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1617 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1618 _cutthrough_flush_send();
1619 /* No wait for response */
1622 tls_close(FALSE, TRUE);
1624 (void)close(cutthrough.fd);
1626 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1628 ctblock.ptr = ctbuffer;
1632 cancel_cutthrough_connection(const char * why)
1634 close_cutthrough_connection(why);
1635 cutthrough.delivery = FALSE;
1641 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1642 Log an OK response as a transmission.
1643 Close the connection.
1644 Return smtp response-class digit.
1647 cutthrough_finaldot(void)
1650 address_item * addr;
1651 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1653 /* Assume data finshed with new-line */
1654 if( !cutthrough_puts(US".", 1)
1655 || !cutthrough_put_nl()
1656 || !cutthrough_flush_send()
1658 return cutthrough.addr.message;
1660 res = cutthrough_response('2', &cutthrough.addr.message);
1661 for (addr = &cutthrough.addr; addr; addr = addr->next)
1663 addr->message = cutthrough.addr.message;
1667 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1668 close_cutthrough_connection("delivered");
1672 delivery_log(LOG_MAIN, addr, 0,
1673 US"tmp-reject from cutthrough after DATA:");
1677 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1678 US"rejected after DATA:");
1685 return cutthrough.addr.message;
1690 /*************************************************
1691 * Copy error to toplevel address *
1692 *************************************************/
1694 /* This function is used when a verify fails or defers, to ensure that the
1695 failure or defer information is in the original toplevel address. This applies
1696 when an address is redirected to a single new address, and the failure or
1697 deferral happens to the child address.
1700 vaddr the verify address item
1701 addr the final address item
1704 Returns: the value of YIELD
1708 copy_error(address_item *vaddr, address_item *addr, int yield)
1712 vaddr->message = addr->message;
1713 vaddr->user_message = addr->user_message;
1714 vaddr->basic_errno = addr->basic_errno;
1715 vaddr->more_errno = addr->more_errno;
1716 vaddr->prop.address_data = addr->prop.address_data;
1717 copyflag(vaddr, addr, af_pass_message);
1725 /**************************************************
1726 * printf that automatically handles TLS if needed *
1727 ***************************************************/
1729 /* This function is used by verify_address() as a substitute for all fprintf()
1730 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1731 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1732 that assumes that we always use the smtp_out FILE* when not using TLS or the
1733 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1734 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1738 f the candidate FILE* to write to
1739 format format string
1740 ... optional arguments
1746 static void PRINTF_FUNCTION(2,3)
1747 respond_printf(FILE *f, const char *format, ...)
1751 va_start(ap, format);
1752 if (smtp_out && (f == smtp_out))
1753 smtp_vprintf(format, ap);
1755 vfprintf(f, format, ap);
1761 /*************************************************
1762 * Verify an email address *
1763 *************************************************/
1765 /* This function is used both for verification (-bv and at other times) and
1766 address testing (-bt), which is indicated by address_test_mode being set.
1769 vaddr contains the address to verify; the next field in this block
1771 f if not NULL, write the result to this file
1772 options various option bits:
1773 vopt_fake_sender => this sender verify is not for the real
1774 sender (it was verify=sender=xxxx or an address from a
1775 header line) - rewriting must not change sender_address
1776 vopt_is_recipient => this is a recipient address, otherwise
1777 it's a sender address - this affects qualification and
1778 rewriting and messages from callouts
1779 vopt_qualify => qualify an unqualified address; else error
1780 vopt_expn => called from SMTP EXPN command
1781 vopt_success_on_redirect => when a new address is generated
1782 the verification instantly succeeds
1784 These ones are used by do_callout() -- the options variable
1787 vopt_callout_fullpm => if postmaster check, do full one
1788 vopt_callout_no_cache => don't use callout cache
1789 vopt_callout_random => do the "random" thing
1790 vopt_callout_recipsender => use real sender for recipient
1791 vopt_callout_recippmaster => use postmaster for recipient
1793 callout if > 0, specifies that callout is required, and gives timeout
1794 for individual commands
1795 callout_overall if > 0, gives overall timeout for the callout function;
1796 if < 0, a default is used (see do_callout())
1797 callout_connect the connection timeout for callouts
1798 se_mailfrom when callout is requested to verify a sender, use this
1799 in MAIL FROM; NULL => ""
1800 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1801 thing and use this as the sender address (may be "")
1803 routed if not NULL, set TRUE if routing succeeded, so we can
1804 distinguish between routing failed and callout failed
1806 Returns: OK address verified
1807 FAIL address failed to verify
1808 DEFER can't tell at present
1812 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1813 int callout_overall, int callout_connect, uschar *se_mailfrom,
1814 uschar *pm_mailfrom, BOOL *routed)
1817 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1818 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1819 BOOL expn = (options & vopt_expn) != 0;
1820 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1823 int verify_type = expn? v_expn :
1824 address_test_mode? v_none :
1825 is_recipient? v_recipient : v_sender;
1826 address_item *addr_list;
1827 address_item *addr_new = NULL;
1828 address_item *addr_remote = NULL;
1829 address_item *addr_local = NULL;
1830 address_item *addr_succeed = NULL;
1831 uschar **failure_ptr = is_recipient?
1832 &recipient_verify_failure : &sender_verify_failure;
1833 uschar *ko_prefix, *cr;
1834 uschar *address = vaddr->address;
1835 uschar *save_sender;
1836 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1838 /* Clear, just in case */
1840 *failure_ptr = NULL;
1842 /* Set up a prefix and suffix for error message which allow us to use the same
1843 output statements both in EXPN mode (where an SMTP response is needed) and when
1844 debugging with an output file. */
1848 ko_prefix = US"553 ";
1851 else ko_prefix = cr = US"";
1853 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1855 if (parse_find_at(address) == NULL)
1857 if ((options & vopt_qualify) == 0)
1860 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1861 ko_prefix, address, cr);
1862 *failure_ptr = US"qualify";
1865 address = rewrite_address_qualify(address, is_recipient);
1870 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1871 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1874 /* Rewrite and report on it. Clear the domain and local part caches - these
1875 may have been set by domains and local part tests during an ACL. */
1877 if (global_rewrite_rules != NULL)
1879 uschar *old = address;
1880 address = rewrite_address(address, is_recipient, FALSE,
1881 global_rewrite_rules, rewrite_existflags);
1884 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1885 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1886 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1890 /* If this is the real sender address, we must update sender_address at
1891 this point, because it may be referred to in the routers. */
1893 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1894 sender_address = address;
1896 /* If the address was rewritten to <> no verification can be done, and we have
1897 to return OK. This rewriting is permitted only for sender addresses; for other
1898 addresses, such rewriting fails. */
1900 if (address[0] == 0) return OK;
1902 /* Flip the legacy TLS-related variables over to the outbound set in case
1903 they're used in the context of a transport used by verification. Reset them
1904 at exit from this routine. */
1906 tls_modify_variables(&tls_out);
1908 /* Save a copy of the sender address for re-instating if we change it to <>
1909 while verifying a sender address (a nice bit of self-reference there). */
1911 save_sender = sender_address;
1913 /* Update the address structure with the possibly qualified and rewritten
1914 address. Set it up as the starting address on the chain of new addresses. */
1916 vaddr->address = address;
1919 /* We need a loop, because an address can generate new addresses. We must also
1920 cope with generated pipes and files at the top level. (See also the code and
1921 comment in deliver.c.) However, it is usually the case that the router for
1922 user's .forward files has its verify flag turned off.
1924 If an address generates more than one child, the loop is used only when
1925 full_info is set, and this can only be set locally. Remote enquiries just get
1926 information about the top level address, not anything that it generated. */
1928 while (addr_new != NULL)
1931 address_item *addr = addr_new;
1933 addr_new = addr->next;
1938 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1939 debug_printf("Considering %s\n", addr->address);
1942 /* Handle generated pipe, file or reply addresses. We don't get these
1943 when handling EXPN, as it does only one level of expansion. */
1945 if (testflag(addr, af_pfr))
1952 if (addr->address[0] == '>')
1954 allow = testflag(addr, af_allow_reply);
1955 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1959 allow = (addr->address[0] == '|')?
1960 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1961 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1964 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1965 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1966 "%s\n", addr->message);
1968 fprintf(f, "\n transport = %s\n", addr->transport->name);
1970 fprintf(f, " *** forbidden ***\n");
1975 /* Just in case some router parameter refers to it. */
1977 return_path = (addr->prop.errors_address != NULL)?
1978 addr->prop.errors_address : sender_address;
1980 /* Split the address into domain and local part, handling the %-hack if
1981 necessary, and then route it. While routing a sender address, set
1982 $sender_address to <> because that is what it will be if we were trying to
1983 send a bounce to the sender. */
1985 if (routed != NULL) *routed = FALSE;
1986 if ((rc = deliver_split_address(addr)) == OK)
1988 if (!is_recipient) sender_address = null_sender;
1989 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1990 &addr_succeed, verify_type);
1991 sender_address = save_sender; /* Put back the real sender */
1994 /* If routing an address succeeded, set the flag that remembers, for use when
1995 an ACL cached a sender verify (in case a callout fails). Then if routing set
1996 up a list of hosts or the transport has a host list, and the callout option
1997 is set, and we aren't in a host checking run, do the callout verification,
1998 and set another flag that notes that a callout happened. */
2002 if (routed != NULL) *routed = TRUE;
2005 host_item *host_list = addr->host_list;
2007 /* Make up some data for use in the case where there is no remote
2010 transport_feedback tf = {
2011 NULL, /* interface (=> any) */
2012 US"smtp", /* port */
2013 US"smtp", /* protocol */
2015 US"$smtp_active_hostname", /* helo_data */
2016 FALSE, /* hosts_override */
2017 FALSE, /* hosts_randomize */
2018 FALSE, /* gethostbyname */
2019 TRUE, /* qualify_single */
2020 FALSE /* search_parents */
2023 /* If verification yielded a remote transport, we want to use that
2024 transport's options, so as to mimic what would happen if we were really
2025 sending a message to this address. */
2027 if (addr->transport != NULL && !addr->transport->info->local)
2029 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
2031 /* If the transport has hosts and the router does not, or if the
2032 transport is configured to override the router's hosts, we must build a
2033 host list of the transport's hosts, and find the IP addresses */
2035 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
2038 const uschar *save_deliver_domain = deliver_domain;
2039 uschar *save_deliver_localpart = deliver_localpart;
2041 host_list = NULL; /* Ignore the router's hosts */
2043 deliver_domain = addr->domain;
2044 deliver_localpart = addr->local_part;
2045 s = expand_string(tf.hosts);
2046 deliver_domain = save_deliver_domain;
2047 deliver_localpart = save_deliver_localpart;
2051 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
2052 "\"%s\" in %s transport for callout: %s", tf.hosts,
2053 addr->transport->name, expand_string_message);
2058 host_item *host, *nexthost;
2059 host_build_hostlist(&host_list, s, tf.hosts_randomize);
2061 /* Just ignore failures to find a host address. If we don't manage
2062 to find any addresses, the callout will defer. Note that more than
2063 one address may be found for a single host, which will result in
2064 additional host items being inserted into the chain. Hence we must
2065 save the next host first. */
2067 flags = HOST_FIND_BY_A;
2068 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2069 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2071 for (host = host_list; host != NULL; host = nexthost)
2073 nexthost = host->next;
2074 if (tf.gethostbyname ||
2075 string_is_ip_address(host->name, NULL) != 0)
2076 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
2079 uschar * d_request = NULL, * d_require = NULL;
2080 if (Ustrcmp(addr->transport->driver_name, "smtp") == 0)
2082 smtp_transport_options_block * ob =
2083 (smtp_transport_options_block *)
2084 addr->transport->options_block;
2085 d_request = ob->dnssec_request_domains;
2086 d_require = ob->dnssec_require_domains;
2089 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2090 d_request, d_require, NULL, NULL);
2097 /* Can only do a callout if we have at least one host! If the callout
2098 fails, it will have set ${sender,recipient}_verify_failure. */
2100 if (host_list != NULL)
2102 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
2103 if (host_checking && !host_checking_callout)
2106 debug_printf("... callout omitted by default when host testing\n"
2107 "(Use -bhc if you want the callouts to happen.)\n");
2112 deliver_set_expansions(addr);
2114 verify_mode = is_recipient ? US"R" : US"S";
2115 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
2116 callout_connect, options, se_mailfrom, pm_mailfrom);
2122 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
2123 "transport provided a host list\n");
2128 /* Otherwise, any failure is a routing failure */
2130 else *failure_ptr = US"route";
2132 /* A router may return REROUTED if it has set up a child address as a result
2133 of a change of domain name (typically from widening). In this case we always
2134 want to continue to verify the new child. */
2136 if (rc == REROUTED) continue;
2138 /* Handle hard failures */
2145 address_item *p = addr->parent;
2147 respond_printf(f, "%s%s %s", ko_prefix,
2148 full_info? addr->address : address,
2149 address_test_mode? "is undeliverable" : "failed to verify");
2150 if (!expn && admin_user)
2152 if (addr->basic_errno > 0)
2153 respond_printf(f, ": %s", strerror(addr->basic_errno));
2154 if (addr->message != NULL)
2155 respond_printf(f, ": %s", addr->message);
2158 /* Show parents iff doing full info */
2160 if (full_info) while (p != NULL)
2162 respond_printf(f, "%s\n <-- %s", cr, p->address);
2165 respond_printf(f, "%s\n", cr);
2167 cancel_cutthrough_connection("routing hard fail");
2171 yield = copy_error(vaddr, addr, FAIL);
2179 else if (rc == DEFER)
2184 address_item *p = addr->parent;
2185 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
2186 full_info? addr->address : address);
2187 if (!expn && admin_user)
2189 if (addr->basic_errno > 0)
2190 respond_printf(f, ": %s", strerror(addr->basic_errno));
2191 if (addr->message != NULL)
2192 respond_printf(f, ": %s", addr->message);
2193 else if (addr->basic_errno <= 0)
2194 respond_printf(f, ": unknown error");
2197 /* Show parents iff doing full info */
2199 if (full_info) while (p != NULL)
2201 respond_printf(f, "%s\n <-- %s", cr, p->address);
2204 respond_printf(f, "%s\n", cr);
2206 cancel_cutthrough_connection("routing soft fail");
2210 yield = copy_error(vaddr, addr, DEFER);
2213 else if (yield == OK) yield = DEFER;
2216 /* If we are handling EXPN, we do not want to continue to route beyond
2217 the top level (whose address is in "address"). */
2221 uschar *ok_prefix = US"250-";
2222 if (addr_new == NULL)
2224 if (addr_local == NULL && addr_remote == NULL)
2225 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2227 respond_printf(f, "250 <%s>\r\n", address);
2229 else while (addr_new != NULL)
2231 address_item *addr2 = addr_new;
2232 addr_new = addr2->next;
2233 if (addr_new == NULL) ok_prefix = US"250 ";
2234 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2240 /* Successful routing other than EXPN. */
2244 /* Handle successful routing when short info wanted. Otherwise continue for
2245 other (generated) addresses. Short info is the operational case. Full info
2246 can be requested only when debug_selector != 0 and a file is supplied.
2248 There is a conflict between the use of aliasing as an alternate email
2249 address, and as a sort of mailing list. If an alias turns the incoming
2250 address into just one address (e.g. J.Caesar->jc44) you may well want to
2251 carry on verifying the generated address to ensure it is valid when
2252 checking incoming mail. If aliasing generates multiple addresses, you
2253 probably don't want to do this. Exim therefore treats the generation of
2254 just a single new address as a special case, and continues on to verify the
2255 generated address. */
2257 if (!full_info && /* Stop if short info wanted AND */
2258 (((addr_new == NULL || /* No new address OR */
2259 addr_new->next != NULL || /* More than one new address OR */
2260 testflag(addr_new, af_pfr))) /* New address is pfr */
2262 (addr_new != NULL && /* At least one new address AND */
2263 success_on_redirect))) /* success_on_redirect is set */
2265 if (f != NULL) fprintf(f, "%s %s\n", address,
2266 address_test_mode? "is deliverable" : "verified");
2268 /* If we have carried on to verify a child address, we want the value
2269 of $address_data to be that of the child */
2271 vaddr->prop.address_data = addr->prop.address_data;
2276 } /* Loop for generated addresses */
2278 /* Display the full results of the successful routing, including any generated
2279 addresses. Control gets here only when full_info is set, which requires f not
2280 to be NULL, and this occurs only when a top-level verify is called with the
2281 debugging switch on.
2283 If there are no local and no remote addresses, and there were no pipes, files,
2284 or autoreplies, and there were no errors or deferments, the message is to be
2285 discarded, usually because of the use of :blackhole: in an alias file. */
2287 if (allok && addr_local == NULL && addr_remote == NULL)
2289 fprintf(f, "mail to %s is discarded\n", address);
2293 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2295 while (addr_list != NULL)
2297 address_item *addr = addr_list;
2298 address_item *p = addr->parent;
2299 addr_list = addr->next;
2301 fprintf(f, "%s", CS addr->address);
2302 #ifdef EXPERIMENTAL_SRS
2303 if(addr->prop.srs_sender)
2304 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2307 /* If the address is a duplicate, show something about it. */
2309 if (!testflag(addr, af_pfr))
2312 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
2313 fprintf(f, " [duplicate, would not be delivered]");
2314 else tree_add_duplicate(addr->unique, addr);
2317 /* Now show its parents */
2321 fprintf(f, "\n <-- %s", p->address);
2326 /* Show router, and transport */
2328 fprintf(f, "router = %s, ", addr->router->name);
2329 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
2330 addr->transport->name);
2332 /* Show any hosts that are set up by a router unless the transport
2333 is going to override them; fiddle a bit to get a nice format. */
2335 if (addr->host_list != NULL && addr->transport != NULL &&
2336 !addr->transport->overrides_hosts)
2341 for (h = addr->host_list; h != NULL; h = h->next)
2343 int len = Ustrlen(h->name);
2344 if (len > maxlen) maxlen = len;
2345 len = (h->address != NULL)? Ustrlen(h->address) : 7;
2346 if (len > maxaddlen) maxaddlen = len;
2348 for (h = addr->host_list; h != NULL; h = h->next)
2350 int len = Ustrlen(h->name);
2351 fprintf(f, " host %s ", h->name);
2352 while (len++ < maxlen) fprintf(f, " ");
2353 if (h->address != NULL)
2355 fprintf(f, "[%s] ", h->address);
2356 len = Ustrlen(h->address);
2358 else if (!addr->transport->info->local) /* Omit [unknown] for local */
2360 fprintf(f, "[unknown] ");
2364 while (len++ < maxaddlen) fprintf(f," ");
2365 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
2366 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2367 if (running_in_test_harness)
2368 #ifndef DISABLE_DNSSEC
2369 fprintf(f, " ad=%s", h->dnssec==DS_YES ? "yes" : "no");
2371 fprintf(f, " ad=no");
2373 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2380 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2381 the -bv or -bt case). */
2384 tls_modify_variables(&tls_in);
2392 /*************************************************
2393 * Check headers for syntax errors *
2394 *************************************************/
2396 /* This function checks those header lines that contain addresses, and verifies
2397 that all the addresses therein are syntactially correct.
2400 msgptr where to put an error message
2407 verify_check_headers(uschar **msgptr)
2413 for (h = header_list; h != NULL && yield == OK; h = h->next)
2415 if (h->type != htype_from &&
2416 h->type != htype_reply_to &&
2417 h->type != htype_sender &&
2418 h->type != htype_to &&
2419 h->type != htype_cc &&
2420 h->type != htype_bcc)
2423 colon = Ustrchr(h->text, ':');
2425 while (isspace(*s)) s++;
2427 /* Loop for multiple addresses in the header, enabling group syntax. Note
2428 that we have to reset this after the header has been scanned. */
2430 parse_allow_group = TRUE;
2434 uschar *ss = parse_find_address_end(s, FALSE);
2435 uschar *recipient, *errmess;
2436 int terminator = *ss;
2437 int start, end, domain;
2439 /* Temporarily terminate the string at this point, and extract the
2440 operative address within, allowing group syntax. */
2443 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2446 /* Permit an unqualified address only if the message is local, or if the
2447 sending host is configured to be permitted to send them. */
2449 if (recipient != NULL && domain == 0)
2451 if (h->type == htype_from || h->type == htype_sender)
2453 if (!allow_unqualified_sender) recipient = NULL;
2457 if (!allow_unqualified_recipient) recipient = NULL;
2459 if (recipient == NULL) errmess = US"unqualified address not permitted";
2462 /* It's an error if no address could be extracted, except for the special
2463 case of an empty address. */
2465 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2467 uschar *verb = US"is";
2472 /* Arrange not to include any white space at the end in the
2473 error message or the header name. */
2475 while (t > s && isspace(t[-1])) t--;
2476 while (tt > h->text && isspace(tt[-1])) tt--;
2478 /* Add the address that failed to the error message, since in a
2479 header with very many addresses it is sometimes hard to spot
2480 which one is at fault. However, limit the amount of address to
2481 quote - cases have been seen where, for example, a missing double
2482 quote in a humungous To: header creates an "address" that is longer
2483 than string_sprintf can handle. */
2492 /* deconst cast ok as we're passing a non-const to string_printing() */
2493 *msgptr = US string_printing(
2494 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2495 errmess, tt - h->text, h->text, verb, len, s));
2498 break; /* Out of address loop */
2501 /* Advance to the next address */
2503 s = ss + (terminator? 1:0);
2504 while (isspace(*s)) s++;
2505 } /* Next address */
2507 parse_allow_group = FALSE;
2508 parse_found_group = FALSE;
2509 } /* Next header unless yield has been set FALSE */
2515 /*************************************************
2516 * Check header names for 8-bit characters *
2517 *************************************************/
2519 /* This function checks for invalid charcters in header names. See
2520 RFC 5322, 2.2. and RFC 6532, 3.
2523 msgptr where to put an error message
2530 verify_check_header_names_ascii(uschar **msgptr)
2535 for (h = header_list; h != NULL; h = h->next)
2537 colon = Ustrchr(h->text, ':');
2538 for(s = h->text; s < colon; s++)
2540 if ((*s < 33) || (*s > 126))
2542 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2543 colon - h->text, h->text);
2551 /*************************************************
2552 * Check for blind recipients *
2553 *************************************************/
2555 /* This function checks that every (envelope) recipient is mentioned in either
2556 the To: or Cc: header lines, thus detecting blind carbon copies.
2558 There are two ways of scanning that could be used: either scan the header lines
2559 and tick off the recipients, or scan the recipients and check the header lines.
2560 The original proposed patch did the former, but I have chosen to do the latter,
2561 because (a) it requires no memory and (b) will use fewer resources when there
2562 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2565 Returns: OK if there are no blind recipients
2566 FAIL if there is at least one blind recipient
2570 verify_check_notblind(void)
2573 for (i = 0; i < recipients_count; i++)
2577 uschar *address = recipients_list[i].address;
2579 for (h = header_list; !found && h != NULL; h = h->next)
2583 if (h->type != htype_to && h->type != htype_cc) continue;
2585 colon = Ustrchr(h->text, ':');
2587 while (isspace(*s)) s++;
2589 /* Loop for multiple addresses in the header, enabling group syntax. Note
2590 that we have to reset this after the header has been scanned. */
2592 parse_allow_group = TRUE;
2596 uschar *ss = parse_find_address_end(s, FALSE);
2597 uschar *recipient,*errmess;
2598 int terminator = *ss;
2599 int start, end, domain;
2601 /* Temporarily terminate the string at this point, and extract the
2602 operative address within, allowing group syntax. */
2605 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2608 /* If we found a valid recipient that has a domain, compare it with the
2609 envelope recipient. Local parts are compared case-sensitively, domains
2610 case-insensitively. By comparing from the start with length "domain", we
2611 include the "@" at the end, which ensures that we are comparing the whole
2612 local part of each address. */
2614 if (recipient != NULL && domain != 0)
2616 found = Ustrncmp(recipient, address, domain) == 0 &&
2617 strcmpic(recipient + domain, address + domain) == 0;
2621 /* Advance to the next address */
2623 s = ss + (terminator? 1:0);
2624 while (isspace(*s)) s++;
2625 } /* Next address */
2627 parse_allow_group = FALSE;
2628 parse_found_group = FALSE;
2629 } /* Next header (if found is false) */
2631 if (!found) return FAIL;
2632 } /* Next recipient */
2639 /*************************************************
2640 * Find if verified sender *
2641 *************************************************/
2643 /* Usually, just a single address is verified as the sender of the message.
2644 However, Exim can be made to verify other addresses as well (often related in
2645 some way), and this is useful in some environments. There may therefore be a
2646 chain of such addresses that have previously been tested. This function finds
2647 whether a given address is on the chain.
2649 Arguments: the address to be verified
2650 Returns: pointer to an address item, or NULL
2654 verify_checked_sender(uschar *sender)
2657 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2658 if (Ustrcmp(sender, addr->address) == 0) break;
2666 /*************************************************
2667 * Get valid header address *
2668 *************************************************/
2670 /* Scan the originator headers of the message, looking for an address that
2671 verifies successfully. RFC 822 says:
2673 o The "Sender" field mailbox should be sent notices of
2674 any problems in transport or delivery of the original
2675 messages. If there is no "Sender" field, then the
2676 "From" field mailbox should be used.
2678 o If the "Reply-To" field exists, then the reply should
2679 go to the addresses indicated in that field and not to
2680 the address(es) indicated in the "From" field.
2682 So we check a Sender field if there is one, else a Reply_to field, else a From
2683 field. As some strange messages may have more than one of these fields,
2684 especially if they are resent- fields, check all of them if there is more than
2688 user_msgptr points to where to put a user error message
2689 log_msgptr points to where to put a log error message
2690 callout timeout for callout check (passed to verify_address())
2691 callout_overall overall callout timeout (ditto)
2692 callout_connect connect callout timeout (ditto)
2693 se_mailfrom mailfrom for verify; NULL => ""
2694 pm_mailfrom sender for pm callout check (passed to verify_address())
2695 options callout options (passed to verify_address())
2696 verrno where to put the address basic_errno
2698 If log_msgptr is set to something without setting user_msgptr, the caller
2699 normally uses log_msgptr for both things.
2701 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2702 FAIL is given if no appropriate headers are found
2706 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2707 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2708 uschar *pm_mailfrom, int options, int *verrno)
2710 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2715 for (i = 0; i < 3 && !done; i++)
2718 for (h = header_list; h != NULL && !done; h = h->next)
2720 int terminator, new_ok;
2721 uschar *s, *ss, *endname;
2723 if (h->type != header_types[i]) continue;
2724 s = endname = Ustrchr(h->text, ':') + 1;
2726 /* Scan the addresses in the header, enabling group syntax. Note that we
2727 have to reset this after the header has been scanned. */
2729 parse_allow_group = TRUE;
2733 address_item *vaddr;
2735 while (isspace(*s) || *s == ',') s++;
2736 if (*s == 0) break; /* End of header */
2738 ss = parse_find_address_end(s, FALSE);
2740 /* The terminator is a comma or end of header, but there may be white
2741 space preceding it (including newline for the last address). Move back
2742 past any white space so we can check against any cached envelope sender
2743 address verifications. */
2745 while (isspace(ss[-1])) ss--;
2749 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2750 (int)(endname - h->text), h->text, s);
2752 /* See if we have already verified this address as an envelope sender,
2753 and if so, use the previous answer. */
2755 vaddr = verify_checked_sender(s);
2757 if (vaddr != NULL && /* Previously checked */
2758 (callout <= 0 || /* No callout needed; OR */
2759 vaddr->special_action > 256)) /* Callout was done */
2761 new_ok = vaddr->special_action & 255;
2762 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2763 *ss = terminator; /* Restore shortened string */
2766 /* Otherwise we run the verification now. We must restore the shortened
2767 string before running the verification, so the headers are correct, in
2768 case there is any rewriting. */
2772 int start, end, domain;
2773 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2778 /* If we found an empty address, just carry on with the next one, but
2779 kill the message. */
2781 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2788 /* If verification failed because of a syntax error, fail this
2789 function, and ensure that the failing address gets added to the error
2792 if (address == NULL)
2795 while (ss > s && isspace(ss[-1])) ss--;
2796 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2797 "scanning for sender: %s in \"%.*s\"",
2798 endname - h->text, h->text, *log_msgptr, ss - s, s);
2804 /* Else go ahead with the sender verification. But it isn't *the*
2805 sender of the message, so set vopt_fake_sender to stop sender_address
2806 being replaced after rewriting or qualification. */
2810 vaddr = deliver_make_addr(address, FALSE);
2811 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2812 callout, callout_overall, callout_connect, se_mailfrom,
2817 /* We now have the result, either newly found, or cached. If we are
2818 giving out error details, set a specific user error. This means that the
2819 last of these will be returned to the user if all three fail. We do not
2820 set a log message - the generic one below will be used. */
2824 *verrno = vaddr->basic_errno;
2825 if (smtp_return_error_details)
2827 *user_msgptr = string_sprintf("Rejected after DATA: "
2828 "could not verify \"%.*s\" header address\n%s: %s",
2829 endname - h->text, h->text, vaddr->address, vaddr->message);
2833 /* Success or defer */
2842 if (new_ok == DEFER) yield = DEFER;
2844 /* Move on to any more addresses in the header */
2847 } /* Next address */
2849 parse_allow_group = FALSE;
2850 parse_found_group = FALSE;
2851 } /* Next header, unless done */
2852 } /* Next header type unless done */
2854 if (yield == FAIL && *log_msgptr == NULL)
2855 *log_msgptr = US"there is no valid sender in any header line";
2857 if (yield == DEFER && *log_msgptr == NULL)
2858 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2866 /*************************************************
2867 * Get RFC 1413 identification *
2868 *************************************************/
2870 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2871 the timeout is set to zero, then the query is not done. There may also be lists
2872 of hosts and nets which are exempt. To guard against malefactors sending
2873 non-printing characters which could, for example, disrupt a message's headers,
2874 make sure the string consists of printing characters only.
2877 port the port to connect to; usually this is IDENT_PORT (113), but when
2878 running in the test harness with -bh a different value is used.
2882 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2886 verify_get_ident(int port)
2888 int sock, host_af, qlen;
2889 int received_sender_port, received_interface_port, n;
2891 uschar buffer[2048];
2893 /* Default is no ident. Check whether we want to do an ident check for this
2896 sender_ident = NULL;
2897 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2900 DEBUG(D_ident) debug_printf("doing ident callback\n");
2902 /* Set up a connection to the ident port of the remote host. Bind the local end
2903 to the incoming interface address. If the sender host address is an IPv6
2904 address, the incoming interface address will also be IPv6. */
2906 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2907 sock = ip_socket(SOCK_STREAM, host_af);
2908 if (sock < 0) return;
2910 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2912 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2917 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2920 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2922 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2923 sender_host_address);
2927 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2928 sender_host_address, strerror(errno));
2933 /* Construct and send the query. */
2935 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2936 qlen = Ustrlen(buffer);
2937 if (send(sock, buffer, qlen, 0) < 0)
2939 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2943 /* Read a response line. We put it into the rest of the buffer, using several
2944 recv() calls if necessary. */
2952 int size = sizeof(buffer) - (p - buffer);
2954 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2955 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2956 if (count <= 0) goto END_OFF; /* Read error or EOF */
2958 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2959 generous, and accept a plain \n terminator as well. The only illegal
2962 for (pp = p; pp < p + count; pp++)
2964 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2967 if (pp[-1] == '\r') pp--;
2969 goto GOT_DATA; /* Break out of both loops */
2973 /* Reached the end of the data without finding \n. Let the loop continue to
2974 read some more, if there is room. */
2981 /* We have received a line of data. Check it carefully. It must start with the
2982 same two port numbers that we sent, followed by data as defined by the RFC. For
2985 12345 , 25 : USERID : UNIX :root
2987 However, the amount of white space may be different to what we sent. In the
2988 "osname" field there may be several sub-fields, comma separated. The data we
2989 actually want to save follows the third colon. Some systems put leading spaces
2990 in it - we discard those. */
2992 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2993 &received_interface_port, &n) != 2 ||
2994 received_sender_port != sender_host_port ||
2995 received_interface_port != interface_port)
2998 p = buffer + qlen + n;
2999 while(isspace(*p)) p++;
3000 if (*p++ != ':') goto END_OFF;
3001 while(isspace(*p)) p++;
3002 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
3004 while(isspace(*p)) p++;
3005 if (*p++ != ':') goto END_OFF;
3006 while (*p != 0 && *p != ':') p++;
3007 if (*p++ == 0) goto END_OFF;
3008 while(isspace(*p)) p++;
3009 if (*p == 0) goto END_OFF;
3011 /* The rest of the line is the data we want. We turn it into printing
3012 characters when we save it, so that it cannot mess up the format of any logging
3013 or Received: lines into which it gets inserted. We keep a maximum of 127
3014 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
3016 sender_ident = US string_printing(string_copyn(p, 127));
3017 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
3027 /*************************************************
3028 * Match host to a single host-list item *
3029 *************************************************/
3031 /* This function compares a host (name or address) against a single item
3032 from a host list. The host name gets looked up if it is needed and is not
3033 already known. The function is called from verify_check_this_host() via
3034 match_check_list(), which is why most of its arguments are in a single block.
3037 arg the argument block (see below)
3038 ss the host-list item
3039 valueptr where to pass back looked up data, or NULL
3040 error for error message when returning ERROR
3043 host_name (a) the host name, or
3044 (b) NULL, implying use sender_host_name and
3045 sender_host_aliases, looking them up if required, or
3046 (c) the empty string, meaning that only IP address matches
3048 host_address the host address
3049 host_ipv4 the IPv4 address taken from an IPv6 one
3053 DEFER lookup deferred
3054 ERROR (a) failed to find the host name or IP address, or
3055 (b) unknown lookup type specified, or
3056 (c) host name encountered when only IP addresses are
3061 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
3063 check_host_block *cb = (check_host_block *)arg;
3066 BOOL iplookup = FALSE;
3067 BOOL isquery = FALSE;
3068 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
3073 /* Optimize for the special case when the pattern is "*". */
3075 if (*ss == '*' && ss[1] == 0) return OK;
3077 /* If the pattern is empty, it matches only in the case when there is no host -
3078 this can occur in ACL checking for SMTP input using the -bs option. In this
3079 situation, the host address is the empty string. */
3081 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
3082 if (*ss == 0) return FAIL;
3084 /* If the pattern is precisely "@" then match against the primary host name,
3085 provided that host name matching is permitted; if it's "@[]" match against the
3086 local host's IP addresses. */
3092 if (isiponly) return ERROR;
3093 ss = primary_hostname;
3095 else if (Ustrcmp(ss, "@[]") == 0)
3097 ip_address_item *ip;
3098 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
3099 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
3104 /* If the pattern is an IP address, optionally followed by a bitmask count, do
3105 a (possibly masked) comparision with the current IP address. */
3107 if (string_is_ip_address(ss, &maskoffset) != 0)
3108 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
3110 /* The pattern is not an IP address. A common error that people make is to omit
3111 one component of an IPv4 address, either by accident, or believing that, for
3112 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,
3113 which it isn't. (Those applications that do accept 1.2.3 as an IP address
3114 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
3115 ancient specification.) To aid in debugging these cases, we give a specific
3116 error if the pattern contains only digits and dots or contains a slash preceded
3117 only by digits and dots (a slash at the start indicates a file name and of
3118 course slashes may be present in lookups, but not preceded only by digits and
3121 for (t = ss; isdigit(*t) || *t == '.'; t++);
3122 if (*t == 0 || (*t == '/' && t != ss))
3124 *error = US"malformed IPv4 address or address mask";
3128 /* See if there is a semicolon in the pattern */
3130 semicolon = Ustrchr(ss, ';');
3132 /* If we are doing an IP address only match, then all lookups must be IP
3133 address lookups, even if there is no "net-". */
3137 iplookup = semicolon != NULL;
3140 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
3141 a lookup on a masked IP network, in textual form. We obey this code even if we
3142 have already set iplookup, so as to skip over the "net-" prefix and to set the
3143 mask length. The net- stuff really only applies to single-key lookups where the
3144 key is implicit. For query-style lookups the key is specified in the query.
3145 From release 4.30, the use of net- for query style is no longer needed, but we
3146 retain it for backward compatibility. */
3148 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
3151 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
3152 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
3153 iplookup = (*t++ == '-');
3157 /* Do the IP address lookup if that is indeed what we have */
3165 uschar *filename, *key, *result;
3168 /* Find the search type */
3170 search_type = search_findtype(t, semicolon - t);
3172 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3173 search_error_message);
3175 /* Adjust parameters for the type of lookup. For a query-style lookup, there
3176 is no file name, and the "key" is just the query. For query-style with a file
3177 name, we have to fish the file off the start of the query. For a single-key
3178 lookup, the key is the current IP address, masked appropriately, and
3179 reconverted to text form, with the mask appended. For IPv6 addresses, specify
3180 dot separators instead of colons, except when the lookup type is "iplsearch".
3183 if (mac_islookup(search_type, lookup_absfilequery))
3185 filename = semicolon + 1;
3187 while (*key != 0 && !isspace(*key)) key++;
3188 filename = string_copyn(filename, key - filename);
3189 while (isspace(*key)) key++;
3191 else if (mac_islookup(search_type, lookup_querystyle))
3194 key = semicolon + 1;
3196 else /* Single-key style */
3198 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3200 insize = host_aton(cb->host_address, incoming);
3201 host_mask(insize, incoming, mlen);
3202 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3204 filename = semicolon + 1;
3207 /* Now do the actual lookup; note that there is no search_close() because
3208 of the caching arrangements. */
3210 handle = search_open(filename, search_type, 0, NULL, NULL);
3211 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3212 search_error_message);
3213 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3214 if (valueptr != NULL) *valueptr = result;
3215 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3218 /* The pattern is not an IP address or network reference of any kind. That is,
3219 it is a host name pattern. If this is an IP only match, there's an error in the
3224 *error = US"cannot match host name in match_ip list";
3228 /* Check the characters of the pattern to see if they comprise only letters,
3229 digits, full stops, and hyphens (the constituents of domain names). Allow
3230 underscores, as they are all too commonly found. Sigh. Also, if
3231 allow_utf8_domains is set, allow top-bit characters. */
3233 for (t = ss; *t != 0; t++)
3234 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3235 (!allow_utf8_domains || *t < 128)) break;
3237 /* If the pattern is a complete domain name, with no fancy characters, look up
3238 its IP address and match against that. Note that a multi-homed host will add
3239 items to the chain. */
3250 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3251 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3254 for (hh = &h; hh != NULL; hh = hh->next)
3256 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3260 if (rc == HOST_FIND_AGAIN) return DEFER;
3261 *error = string_sprintf("failed to find IP address for %s", ss);
3265 /* Almost all subsequent comparisons require the host name, and can be done
3266 using the general string matching function. When this function is called for
3267 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3268 must use sender_host_name and its aliases, looking them up if necessary. */
3270 if (cb->host_name != NULL) /* Explicit host name given */
3271 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3274 /* Host name not given; in principle we need the sender host name and its
3275 aliases. However, for query-style lookups, we do not need the name if the
3276 query does not contain $sender_host_name. From release 4.23, a reference to
3277 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3280 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3282 const uschar *affix;
3283 int partial, affixlen, starflags, id;
3286 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3289 if (id < 0) /* Unknown lookup type */
3291 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3292 search_error_message, ss);
3295 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3300 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3303 case DEFER: return DEFER;
3304 default: return FAIL;
3308 /* Not a query-style lookup; must ensure the host name is present, and then we
3309 do a check on the name and all its aliases. */
3311 if (sender_host_name == NULL)
3313 HDEBUG(D_host_lookup)
3314 debug_printf("sender host name required, to match against %s\n", ss);
3315 if (host_lookup_failed || host_name_lookup() != OK)
3317 *error = string_sprintf("failed to find host name for %s",
3318 sender_host_address);;
3321 host_build_sender_fullhost();
3324 /* Match on the sender host name, using the general matching function */
3326 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3330 case DEFER: return DEFER;
3333 /* If there are aliases, try matching on them. */
3335 aliases = sender_host_aliases;
3336 while (*aliases != NULL)
3338 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3341 case DEFER: return DEFER;
3350 /*************************************************
3351 * Check a specific host matches a host list *
3352 *************************************************/
3354 /* This function is passed a host list containing items in a number of
3355 different formats and the identity of a host. Its job is to determine whether
3356 the given host is in the set of hosts defined by the list. The host name is
3357 passed as a pointer so that it can be looked up if needed and not already
3358 known. This is commonly the case when called from verify_check_host() to check
3359 an incoming connection. When called from elsewhere the host name should usually
3362 This function is now just a front end to match_check_list(), which runs common
3363 code for scanning a list. We pass it the check_host() function to perform a
3367 listptr pointer to the host list
3368 cache_bits pointer to cache for named lists, or NULL
3369 host_name the host name or NULL, implying use sender_host_name and
3370 sender_host_aliases, looking them up if required
3371 host_address the IP address
3372 valueptr if not NULL, data from a lookup is passed back here
3374 Returns: OK if the host is in the defined set
3375 FAIL if the host is not in the defined set,
3376 DEFER if a data lookup deferred (not a host lookup)
3378 If the host name was needed in order to make a comparison, and could not be
3379 determined from the IP address, the result is FAIL unless the item
3380 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3383 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3384 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3387 unsigned int *local_cache_bits = cache_bits;
3388 const uschar *save_host_address = deliver_host_address;
3389 check_host_block cb;
3390 cb.host_name = host_name;
3391 cb.host_address = host_address;
3393 if (valueptr != NULL) *valueptr = NULL;
3395 /* If the host address starts off ::ffff: it is an IPv6 address in
3396 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3399 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3400 host_address + 7 : host_address;
3402 /* During the running of the check, put the IP address into $host_address. In
3403 the case of calls from the smtp transport, it will already be there. However,
3404 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3405 the safe side, any existing setting is preserved, though as I write this
3406 (November 2004) I can't see any cases where it is actually needed. */
3408 deliver_host_address = host_address;
3409 rc = match_check_list(
3410 listptr, /* the list */
3411 0, /* separator character */
3412 &hostlist_anchor, /* anchor pointer */
3413 &local_cache_bits, /* cache pointer */
3414 check_host, /* function for testing */
3415 &cb, /* argument for function */
3416 MCL_HOST, /* type of check */
3417 (host_address == sender_host_address)?
3418 US"host" : host_address, /* text for debugging */
3419 valueptr); /* where to pass back data */
3420 deliver_host_address = save_host_address;
3427 /*************************************************
3428 * Check the given host item matches a list *
3429 *************************************************/
3431 verify_check_given_host(uschar **listptr, host_item *host)
3433 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3436 /*************************************************
3437 * Check the remote host matches a list *
3438 *************************************************/
3440 /* This is a front end to verify_check_this_host(), created because checking
3441 the remote host is a common occurrence. With luck, a good compiler will spot
3442 the tail recursion and optimize it. If there's no host address, this is
3443 command-line SMTP input - check against an empty string for the address.
3446 listptr pointer to the host list
3448 Returns: the yield of verify_check_this_host(),
3449 i.e. OK, FAIL, or DEFER
3453 verify_check_host(uschar **listptr)
3455 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3456 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3463 /*************************************************
3464 * Invert an IP address *
3465 *************************************************/
3467 /* Originally just used for DNS xBL lists, now also used for the
3468 reverse_ip expansion operator.
3471 buffer where to put the answer
3472 address the address to invert
3476 invert_address(uschar *buffer, uschar *address)
3479 uschar *bptr = buffer;
3481 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3482 to the IPv4 part only. */
3484 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3486 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3489 if (host_aton(address, bin) == 1)
3493 for (i = 0; i < 4; i++)
3495 sprintf(CS bptr, "%d.", x & 255);
3496 while (*bptr) bptr++;
3501 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3502 in any DNS black lists, and the format in which they will be looked up is
3503 unknown. This is just a guess. */
3509 for (j = 3; j >= 0; j--)
3512 for (i = 0; i < 8; i++)
3514 sprintf(CS bptr, "%x.", x & 15);
3515 while (*bptr) bptr++;
3522 /* Remove trailing period -- this is needed so that both arbitrary
3523 dnsbl keydomains and inverted addresses may be combined with the
3524 same format string, "%s.%s" */
3531 /*************************************************
3532 * Perform a single dnsbl lookup *
3533 *************************************************/
3535 /* This function is called from verify_check_dnsbl() below. It is also called
3536 recursively from within itself when domain and domain_txt are different
3537 pointers, in order to get the TXT record from the alternate domain.
3540 domain the outer dnsbl domain
3541 domain_txt alternate domain to lookup TXT record on success; when the
3542 same domain is to be used, domain_txt == domain (that is,
3543 the pointers must be identical, not just the text)
3544 keydomain the current keydomain (for debug message)
3545 prepend subdomain to lookup (like keydomain, but
3546 reversed if IP address)
3547 iplist the list of matching IP addresses, or NULL for "any"
3548 bitmask true if bitmask matching is wanted
3549 match_type condition for 'succeed' result
3550 0 => Any RR in iplist (=)
3551 1 => No RR in iplist (!=)
3552 2 => All RRs in iplist (==)
3553 3 => Some RRs not in iplist (!==)
3554 the two bits are defined as MT_NOT and MT_ALL
3555 defer_return what to return for a defer
3557 Returns: OK if lookup succeeded
3562 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3563 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3569 dnsbl_cache_block *cb;
3570 int old_pool = store_pool;
3571 uschar query[256]; /* DNS domain max length */
3573 /* Construct the specific query domainname */
3575 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3577 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3578 "(ignored): %s...", query);
3582 /* Look for this query in the cache. */
3584 t = tree_search(dnsbl_cache, query);
3586 /* If not cached from a previous lookup, we must do a DNS lookup, and
3587 cache the result in permanent memory. */
3591 store_pool = POOL_PERM;
3593 /* Set up a tree entry to cache the lookup */
3595 t = store_get(sizeof(tree_node) + Ustrlen(query));
3596 Ustrcpy(t->name, query);
3597 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3598 (void)tree_insertnode(&dnsbl_cache, t);
3600 /* Do the DNS loopup . */
3602 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3603 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3604 cb->text_set = FALSE;
3608 /* If the lookup succeeded, cache the RHS address. The code allows for
3609 more than one address - this was for complete generality and the possible
3610 use of A6 records. However, A6 records have been reduced to experimental
3611 status (August 2001) and may die out. So they may never get used at all,
3612 let alone in dnsbl records. However, leave the code here, just in case.
3614 Quite apart from one A6 RR generating multiple addresses, there are DNS
3615 lists that return more than one A record, so we must handle multiple
3616 addresses generated in that way as well. */
3618 if (cb->rc == DNS_SUCCEED)
3621 dns_address **addrp = &(cb->rhs);
3622 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3624 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3626 if (rr->type == T_A)
3628 dns_address *da = dns_address_from_rr(&dnsa, rr);
3632 while (da->next != NULL) da = da->next;
3633 addrp = &(da->next);
3638 /* If we didn't find any A records, change the return code. This can
3639 happen when there is a CNAME record but there are no A records for what
3642 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3645 store_pool = old_pool;
3648 /* Previous lookup was cached */
3652 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3656 /* We now have the result of the DNS lookup, either newly done, or cached
3657 from a previous call. If the lookup succeeded, check against the address
3658 list if there is one. This may be a positive equality list (introduced by
3659 "="), a negative equality list (introduced by "!="), a positive bitmask
3660 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3662 if (cb->rc == DNS_SUCCEED)
3664 dns_address *da = NULL;
3665 uschar *addlist = cb->rhs->address;
3667 /* For A and AAAA records, there may be multiple addresses from multiple
3668 records. For A6 records (currently not expected to be used) there may be
3669 multiple addresses from a single record. */
3671 for (da = cb->rhs->next; da != NULL; da = da->next)
3672 addlist = string_sprintf("%s, %s", addlist, da->address);
3674 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3677 /* Address list check; this can be either for equality, or via a bitmask.
3678 In the latter case, all the bits must match. */
3682 for (da = cb->rhs; da != NULL; da = da->next)
3686 const uschar *ptr = iplist;
3689 /* Handle exact matching */
3693 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3695 if (Ustrcmp(CS da->address, ip) == 0) break;
3699 /* Handle bitmask matching */
3706 /* At present, all known DNS blocking lists use A records, with
3707 IPv4 addresses on the RHS encoding the information they return. I
3708 wonder if this will linger on as the last vestige of IPv4 when IPv6
3709 is ubiquitous? Anyway, for now we use paranoia code to completely
3710 ignore IPv6 addresses. The default mask is 0, which always matches.
3711 We change this only for IPv4 addresses in the list. */
3713 if (host_aton(da->address, address) == 1) mask = address[0];
3715 /* Scan the returned addresses, skipping any that are IPv6 */
3717 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3719 if (host_aton(ip, address) != 1) continue;
3720 if ((address[0] & mask) == address[0]) break;
3726 (a) An IP address in an any ('=') list matched, or
3727 (b) No IP address in an all ('==') list matched
3729 then we're done searching. */
3731 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3734 /* If da == NULL, either
3736 (a) No IP address in an any ('=') list matched, or
3737 (b) An IP address in an all ('==') list didn't match
3739 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3742 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3750 res = US"was no match";
3753 res = US"was an exclude match";
3756 res = US"was an IP address that did not match";
3759 res = US"were no IP addresses that did not match";
3762 debug_printf("=> but we are not accepting this block class because\n");
3763 debug_printf("=> there %s for %s%c%s\n",
3765 ((match_type & MT_ALL) == 0)? "" : "=",
3766 bitmask? '&' : '=', iplist);
3772 /* Either there was no IP list, or the record matched, implying that the
3773 domain is on the list. We now want to find a corresponding TXT record. If an
3774 alternate domain is specified for the TXT record, call this function
3775 recursively to look that up; this has the side effect of re-checking that
3776 there is indeed an A record at the alternate domain. */
3778 if (domain_txt != domain)
3779 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3780 FALSE, match_type, defer_return);
3782 /* If there is no alternate domain, look up a TXT record in the main domain
3783 if it has not previously been cached. */
3787 cb->text_set = TRUE;
3788 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3791 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3793 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3794 if (rr->type == T_TXT) break;
3797 int len = (rr->data)[0];
3798 if (len > 511) len = 127;
3799 store_pool = POOL_PERM;
3800 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3801 store_pool = old_pool;
3806 dnslist_value = addlist;
3807 dnslist_text = cb->text;
3811 /* There was a problem with the DNS lookup */
3813 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3815 log_write(L_dnslist_defer, LOG_MAIN,
3816 "DNS list lookup defer (probably timeout) for %s: %s", query,
3817 (defer_return == OK)? US"assumed in list" :
3818 (defer_return == FAIL)? US"assumed not in list" :
3819 US"returned DEFER");
3820 return defer_return;
3823 /* No entry was found in the DNS; continue for next domain */
3827 debug_printf("DNS lookup for %s failed\n", query);
3828 debug_printf("=> that means %s is not listed at %s\n",
3838 /*************************************************
3839 * Check host against DNS black lists *
3840 *************************************************/
3842 /* This function runs checks against a list of DNS black lists, until one
3843 matches. Each item on the list can be of the form
3845 domain=ip-address/key
3847 The domain is the right-most domain that is used for the query, for example,
3848 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3849 if the DNS lookup returns a matching IP address. Several addresses may be
3850 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3852 If no key is given, what is looked up in the domain is the inverted IP address
3853 of the current client host. If a key is given, it is used to construct the
3854 domain for the lookup. For example:
3856 dsn.rfc-ignorant.org/$sender_address_domain
3858 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3859 then we check for a TXT record for an error message, and if found, save its
3860 value in $dnslist_text. We also cache everything in a tree, to optimize
3863 The TXT record is normally looked up in the same domain as the A record, but
3864 when many lists are combined in a single DNS domain, this will not be a very
3865 specific message. It is possible to specify a different domain for looking up
3866 TXT records; this is given before the main domain, comma-separated. For
3869 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3870 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3872 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3874 Note: an address for testing RBL is 192.203.178.39
3875 Note: an address for testing DUL is 192.203.178.4
3876 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3879 listptr the domain/address/data list
3881 Returns: OK successful lookup (i.e. the address is on the list), or
3882 lookup deferred after +include_unknown
3883 FAIL name not found, or no data found for the given type, or
3884 lookup deferred after +exclude_unknown (default)
3885 DEFER lookup failure, if +defer_unknown was set
3889 verify_check_dnsbl(const uschar **listptr)
3892 int defer_return = FAIL;
3893 const uschar *list = *listptr;
3896 uschar buffer[1024];
3897 uschar revadd[128]; /* Long enough for IPv6 address */
3899 /* Indicate that the inverted IP address is not yet set up */
3903 /* In case this is the first time the DNS resolver is being used. */
3905 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3907 /* Loop through all the domains supplied, until something matches */
3909 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3912 BOOL bitmask = FALSE;
3919 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3921 /* Deal with special values that change the behaviour on defer */
3923 if (domain[0] == '+')
3925 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3926 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3927 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3929 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3934 /* See if there's explicit data to be looked up */
3936 key = Ustrchr(domain, '/');
3937 if (key != NULL) *key++ = 0;
3939 /* See if there's a list of addresses supplied after the domain name. This is
3940 introduced by an = or a & character; if preceded by = we require all matches
3941 and if preceded by ! we invert the result. */
3943 iplist = Ustrchr(domain, '=');
3947 iplist = Ustrchr(domain, '&');
3950 if (iplist != NULL) /* Found either = or & */
3952 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3954 match_type |= MT_NOT;
3958 *iplist++ = 0; /* Terminate domain, move on */
3960 /* If we found = (bitmask == FALSE), check for == or =& */
3962 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3964 bitmask = *iplist++ == '&';
3965 match_type |= MT_ALL;
3969 /* If there is a comma in the domain, it indicates that a second domain for
3970 looking up TXT records is provided, before the main domain. Otherwise we must
3971 set domain_txt == domain. */
3973 domain_txt = domain;
3974 comma = Ustrchr(domain, ',');
3981 /* Check that what we have left is a sensible domain name. There is no reason
3982 why these domains should in fact use the same syntax as hosts and email
3983 domains, but in practice they seem to. However, there is little point in
3984 actually causing an error here, because that would no doubt hold up incoming
3985 mail. Instead, I'll just log it. */
3987 for (s = domain; *s != 0; s++)
3989 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3991 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3992 "strange characters - is this right?", domain);
3997 /* Check the alternate domain if present */
3999 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
4001 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
4003 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
4004 "strange characters - is this right?", domain_txt);
4009 /* If there is no key string, construct the query by adding the domain name
4010 onto the inverted host address, and perform a single DNS lookup. */
4014 if (sender_host_address == NULL) return FAIL; /* can never match */
4015 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
4016 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
4017 iplist, bitmask, match_type, defer_return);
4020 dnslist_domain = string_copy(domain_txt);
4021 dnslist_matched = string_copy(sender_host_address);
4022 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4023 sender_host_address, dnslist_domain);
4025 if (rc != FAIL) return rc; /* OK or DEFER */
4028 /* If there is a key string, it can be a list of domains or IP addresses to
4029 be concatenated with the main domain. */
4036 uschar keybuffer[256];
4037 uschar keyrevadd[128];
4039 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
4040 sizeof(keybuffer))) != NULL)
4042 uschar *prepend = keydomain;
4044 if (string_is_ip_address(keydomain, NULL) != 0)
4046 invert_address(keyrevadd, keydomain);
4047 prepend = keyrevadd;
4050 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
4051 bitmask, match_type, defer_return);
4055 dnslist_domain = string_copy(domain_txt);
4056 dnslist_matched = string_copy(keydomain);
4057 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4058 keydomain, dnslist_domain);
4062 /* If the lookup deferred, remember this fact. We keep trying the rest
4063 of the list to see if we get a useful result, and if we don't, we return
4064 DEFER at the end. */
4066 if (rc == DEFER) defer = TRUE;
4067 } /* continue with next keystring domain/address */
4069 if (defer) return DEFER;
4071 } /* continue with next dnsdb outer domain */
4078 /* End of verify.c */