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 address_item cutthrough_addr;
18 static smtp_outblock ctblock;
19 uschar ctbuffer[8192];
22 /* Structure for caching DNSBL lookups */
24 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
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, uschar *key, uschar *type,
62 int positive_expire, int negative_expire)
67 dbdata_callout_cache *cache_record;
69 cache_record = dbfn_read_with_length(dbm_file, key, &length);
71 if (cache_record == NULL)
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type);
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
85 if (now - cache_record->time_stamp > expire)
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type);
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
99 if (length == sizeof(dbdata_callout_cache_obs))
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type);
120 /*************************************************
121 * Do callout verification for an address *
122 *************************************************/
124 /* This function is called from verify_address() when the address has routed to
125 a host list, and a callout has been requested. Callouts are expensive; that is
126 why a cache is used to improve the efficiency.
129 addr the address that's been routed
130 host_list the list of hosts to try
131 tf the transport feedback block
133 ifstring "interface" option from transport, or NULL
134 portstring "port" option from transport, or NULL
135 protocolstring "protocol" option from transport, or NULL
136 callout the per-command callout timeout
137 callout_overall the overall callout timeout (if < 0 use 4*callout)
138 callout_connect the callout connection timeout (if < 0 use callout)
139 options the verification options - these bits are used:
140 vopt_is_recipient => this is a recipient address
141 vopt_callout_no_cache => don't use callout cache
142 vopt_callout_fullpm => if postmaster check, do full one
143 vopt_callout_random => do the "random" thing
144 vopt_callout_recipsender => use real sender for recipient
145 vopt_callout_recippmaster => use postmaster for recipient
146 se_mailfrom MAIL FROM address for sender verify; NULL => ""
147 pm_mailfrom if non-NULL, do the postmaster check with this sender
149 Returns: OK/FAIL/DEFER
153 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
154 int callout, int callout_overall, int callout_connect, int options,
155 uschar *se_mailfrom, uschar *pm_mailfrom)
157 BOOL is_recipient = (options & vopt_is_recipient) != 0;
158 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
159 BOOL callout_random = (options & vopt_callout_random) != 0;
162 int old_domain_cache_result = ccache_accept;
165 uschar *from_address;
166 uschar *random_local_part = NULL;
167 uschar *save_deliver_domain = deliver_domain;
168 uschar **failure_ptr = is_recipient?
169 &recipient_verify_failure : &sender_verify_failure;
171 open_db *dbm_file = NULL;
172 dbdata_callout_cache new_domain_record;
173 dbdata_callout_cache_address new_address_record;
175 time_t callout_start_time;
177 new_domain_record.result = ccache_unknown;
178 new_domain_record.postmaster_result = ccache_unknown;
179 new_domain_record.random_result = ccache_unknown;
181 memset(&new_address_record, 0, sizeof(new_address_record));
183 /* For a recipient callout, the key used for the address cache record must
184 include the sender address if we are using the real sender in the callout,
185 because that may influence the result of the callout. */
187 address_key = addr->address;
192 if ((options & vopt_callout_recipsender) != 0)
194 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
195 from_address = sender_address;
197 else if ((options & vopt_callout_recippmaster) != 0)
199 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
200 qualify_domain_sender);
201 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
205 /* For a sender callout, we must adjust the key if the mailfrom address is not
210 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
211 if (from_address[0] != 0)
212 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
215 /* Open the callout cache database, it it exists, for reading only at this
216 stage, unless caching has been disabled. */
218 if (callout_no_cache)
220 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
222 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
224 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
227 /* If a cache database is available see if we can avoid the need to do an
228 actual callout by making use of previously-obtained data. */
230 if (dbm_file != NULL)
232 dbdata_callout_cache_address *cache_address_record;
233 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
234 addr->domain, US"domain",
235 callout_cache_domain_positive_expire,
236 callout_cache_domain_negative_expire);
238 /* If an unexpired cache record was found for this domain, see if the callout
239 process can be short-circuited. */
241 if (cache_record != NULL)
243 /* In most cases, if an early command (up to and including MAIL FROM:<>)
244 was rejected, there is no point carrying on. The callout fails. However, if
245 we are doing a recipient verification with use_sender or use_postmaster
246 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
247 will be using a non-empty sender. We have to remember this situation so as
248 not to disturb the cached domain value if this whole verification succeeds
249 (we don't want it turning into "accept"). */
251 old_domain_cache_result = cache_record->result;
253 if (cache_record->result == ccache_reject ||
254 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
256 setflag(addr, af_verify_nsfail);
258 debug_printf("callout cache: domain gave initial rejection, or "
259 "does not accept HELO or MAIL FROM:<>\n");
260 setflag(addr, af_verify_nsfail);
261 addr->user_message = US"(result of an earlier callout reused).";
263 *failure_ptr = US"mail";
267 /* If a previous check on a "random" local part was accepted, we assume
268 that the server does not do any checking on local parts. There is therefore
269 no point in doing the callout, because it will always be successful. If a
270 random check previously failed, arrange not to do it again, but preserve
271 the data in the new record. If a random check is required but hasn't been
272 done, skip the remaining cache processing. */
274 if (callout_random) switch(cache_record->random_result)
278 debug_printf("callout cache: domain accepts random addresses\n");
279 goto END_CALLOUT; /* Default yield is OK */
283 debug_printf("callout cache: domain rejects random addresses\n");
284 callout_random = FALSE;
285 new_domain_record.random_result = ccache_reject;
286 new_domain_record.random_stamp = cache_record->random_stamp;
291 debug_printf("callout cache: need to check random address handling "
292 "(not cached or cache expired)\n");
296 /* If a postmaster check is requested, but there was a previous failure,
297 there is again no point in carrying on. If a postmaster check is required,
298 but has not been done before, we are going to have to do a callout, so skip
299 remaining cache processing. */
301 if (pm_mailfrom != NULL)
303 if (cache_record->postmaster_result == ccache_reject)
305 setflag(addr, af_verify_pmfail);
307 debug_printf("callout cache: domain does not accept "
308 "RCPT TO:<postmaster@domain>\n");
310 *failure_ptr = US"postmaster";
311 setflag(addr, af_verify_pmfail);
312 addr->user_message = US"(result of earlier verification reused).";
315 if (cache_record->postmaster_result == ccache_unknown)
318 debug_printf("callout cache: need to check RCPT "
319 "TO:<postmaster@domain> (not cached or cache expired)\n");
323 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
324 postmaster check if the address itself has to be checked. Also ensure
325 that the value in the cache record is preserved (with its old timestamp).
328 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
329 "TO:<postmaster@domain>\n");
331 new_domain_record.postmaster_result = ccache_accept;
332 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
336 /* We can't give a result based on information about the domain. See if there
337 is an unexpired cache record for this specific address (combined with the
338 sender address if we are doing a recipient callout with a non-empty sender).
341 cache_address_record = (dbdata_callout_cache_address *)
342 get_callout_cache_record(dbm_file,
343 address_key, US"address",
344 callout_cache_positive_expire,
345 callout_cache_negative_expire);
347 if (cache_address_record != NULL)
349 if (cache_address_record->result == ccache_accept)
352 debug_printf("callout cache: address record is positive\n");
357 debug_printf("callout cache: address record is negative\n");
358 addr->user_message = US"Previous (cached) callout verification failure";
359 *failure_ptr = US"recipient";
365 /* Close the cache database while we actually do the callout for real. */
368 dbfn_close(dbm_file);
372 if (!addr->transport)
374 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
376 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
377 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
378 addr->transport->name, addr->transport->driver_name);
381 smtp_transport_options_block *ob =
382 (smtp_transport_options_block *)addr->transport->options_block;
384 /* The information wasn't available in the cache, so we have to do a real
385 callout and save the result in the cache for next time, unless no_cache is set,
386 or unless we have a previously cached negative random result. If we are to test
387 with a random local part, ensure that such a local part is available. If not,
388 log the fact, but carry on without randomming. */
390 if (callout_random && callout_random_local_part != NULL)
392 random_local_part = expand_string(callout_random_local_part);
393 if (random_local_part == NULL)
394 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
395 "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 /* Now make connections to the hosts and do real callouts. The list of hosts
414 is passed in as an argument. */
416 for (host = host_list; host != NULL && !done; host = host->next)
418 smtp_inblock inblock;
419 smtp_outblock outblock;
422 BOOL send_quit = TRUE;
423 uschar *active_hostname = smtp_active_hostname;
427 BOOL suppress_tls = FALSE;
428 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
429 uschar inbuffer[4096];
430 uschar outbuffer[1024];
431 uschar responsebuffer[4096];
433 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
434 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
436 /* Skip this host if we don't have an IP address for it. */
438 if (host->address == NULL)
440 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
445 /* Check the overall callout timeout */
447 if (time(NULL) - callout_start_time >= callout_overall)
449 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
453 /* Set IPv4 or IPv6 */
455 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
457 /* Expand and interpret the interface and port strings. The latter will not
458 be used if there is a host-specific port (e.g. from a manualroute router).
459 This has to be delayed till now, because they may expand differently for
460 different hosts. If there's a failure, log it, but carry on with the
463 deliver_host = host->name;
464 deliver_host_address = host->address;
465 deliver_domain = addr->domain;
467 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
469 !smtp_get_port(tf->port, addr, &port, US"callout"))
470 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
473 /* Set HELO string according to the protocol */
474 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
475 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
478 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
480 /* Set up the buffer for reading SMTP response packets. */
482 inblock.buffer = inbuffer;
483 inblock.buffersize = sizeof(inbuffer);
484 inblock.ptr = inbuffer;
485 inblock.ptrend = inbuffer;
487 /* Set up the buffer for holding SMTP commands while pipelining */
489 outblock.buffer = outbuffer;
490 outblock.buffersize = sizeof(outbuffer);
491 outblock.ptr = outbuffer;
492 outblock.cmd_count = 0;
493 outblock.authenticating = FALSE;
495 /* Reset the parameters of a TLS session */
496 tls_out.cipher = tls_out.peerdn = NULL;
498 /* Connect to the host; on failure, just loop for the next one, but we
499 set the error for the last one. Use the callout_connect timeout. */
501 tls_retry_connection:
503 inblock.sock = outblock.sock =
504 smtp_connect(host, host_af, port, interface, callout_connect, TRUE, NULL);
505 /* reconsider DSCP here */
506 if (inblock.sock < 0)
508 addr->message = string_sprintf("could not connect to %s [%s]: %s",
509 host->name, host->address, strerror(errno));
510 deliver_host = deliver_host_address = NULL;
511 deliver_domain = save_deliver_domain;
515 /* Expand the helo_data string to find the host name to use. */
517 if (tf->helo_data != NULL)
519 uschar *s = expand_string(tf->helo_data);
521 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
522 "helo_data value for callout: %s", addr->address,
523 expand_string_message);
524 else active_hostname = s;
527 /* Wait for initial response, and send HELO. The smtp_write_command()
528 function leaves its command in big_buffer. This is used in error responses.
529 Initialize it in case the connection is rejected. */
531 Ustrcpy(big_buffer, "initial connection");
533 /* Unless ssl-on-connect, wait for the initial greeting */
537 if (!smtps || (smtps && tls_out.active >= 0))
539 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
540 goto RESPONSE_FAILED;
542 /* Not worth checking greeting line for ESMTP support */
543 if (!(esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
544 host->name, host->address, NULL) != OK))
546 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
551 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
554 ob->tls_tempfail_tryclear = FALSE;
556 else /* all other cases */
561 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
562 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
564 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
566 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
569 goto RESPONSE_FAILED;
575 goto esmtp_retry; /* fallback to HELO */
578 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
580 if (esmtp && !suppress_tls && tls_out.active < 0)
582 if (regex_STARTTLS == NULL) regex_STARTTLS =
583 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
585 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
586 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
593 /* If TLS is available on this connection attempt to
594 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
595 send another EHLO - the server may give a different answer in secure mode. We
596 use a separate buffer for reading the response to STARTTLS so that if it is
597 negative, the original EHLO data is available for subsequent analysis, should
598 the client not be required to use TLS. If the response is bad, copy the buffer
599 for error analysis. */
603 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
604 host->address, NULL) != OK &&
605 verify_check_this_host(&(ob->hosts_verify_avoid_tls), NULL, host->name,
606 host->address, NULL) != OK
609 uschar buffer2[4096];
611 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
614 /* If there is an I/O error, transmission of this message is deferred. If
615 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
616 false, we also defer. However, if there is a temporary rejection of STARTTLS
617 and tls_tempfail_tryclear is true, or if there is an outright rejection of
618 STARTTLS, we carry on. This means we will try to send the message in clear,
619 unless the host is in hosts_require_tls (tested below). */
621 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
622 ob->command_timeout))
624 if (errno != 0 || buffer2[0] == 0 ||
625 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
627 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
629 goto RESPONSE_FAILED;
633 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
636 int oldtimeout = ob->command_timeout;
639 ob->command_timeout = callout;
640 rc = tls_client_start(inblock.sock, host, addr, ob);
641 ob->command_timeout = oldtimeout;
643 /* TLS negotiation failed; give an error. Try in clear on a new connection,
644 if the options permit it for this host. */
647 if (rc == DEFER && ob->tls_tempfail_tryclear && !smtps &&
648 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
649 host->address, NULL) != OK)
651 (void)close(inblock.sock);
652 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
653 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
655 goto tls_retry_connection;
657 /*save_errno = ERRNO_TLSFAILURE;*/
658 /*message = US"failure while setting up TLS session";*/
664 /* TLS session is set up. Copy info for logging. */
665 addr->cipher = tls_out.cipher;
666 addr->peerdn = tls_out.peerdn;
668 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
670 goto smtps_redo_greeting;
672 /* For STARTTLS we need to redo EHLO */
677 /* If the host is required to use a secure channel, ensure that we have one. */
678 if (tls_out.active < 0)
679 if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
680 host->address, NULL) == OK)
682 /*save_errno = ERRNO_TLSREQUIRED;*/
683 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
684 host->name, host->address,
685 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
690 #endif /*SUPPORT_TLS*/
692 done = TRUE; /* so far so good; have response to HELO */
694 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
696 /* For now, transport_filter by cutthrough-delivery is not supported */
697 /* Need proper integration with the proper transport mechanism. */
698 if (cutthrough_delivery)
700 if (addr->transport->filter_command)
702 cutthrough_delivery= FALSE;
703 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
708 cutthrough_delivery= FALSE;
709 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
718 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
720 /* Failure to accept HELO is cached; this blocks the whole domain for all
721 senders. I/O errors and defer responses are not cached. */
725 *failure_ptr = US"mail"; /* At or before MAIL */
726 if (errno == 0 && responsebuffer[0] == '5')
728 setflag(addr, af_verify_nsfail);
729 new_domain_record.result = ccache_reject;
733 /* If we haven't authenticated, but are required to, give up. */
736 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
737 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
739 /* Copy AUTH info for logging */
740 ( (addr->authenticator = client_authenticator),
741 (addr->auth_id = client_authenticated_id),
743 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
744 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
747 ( (addr->auth_sndr = client_authenticated_sender),
749 /* Send the MAIL command */
750 (smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>%s\r\n",
751 from_address, responsebuffer) >= 0)
754 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
757 deliver_host = deliver_host_address = NULL;
758 deliver_domain = save_deliver_domain;
760 /* If the host does not accept MAIL FROM:<>, arrange to cache this
761 information, but again, don't record anything for an I/O error or a defer. Do
762 not cache rejections of MAIL when a non-empty sender has been used, because
763 that blocks the whole domain for all senders. */
767 *failure_ptr = US"mail"; /* At or before MAIL */
768 if (errno == 0 && responsebuffer[0] == '5')
770 setflag(addr, af_verify_nsfail);
771 if (from_address[0] == 0)
772 new_domain_record.result = ccache_reject_mfnull;
776 /* Otherwise, proceed to check a "random" address (if required), then the
777 given address, and the postmaster address (if required). Between each check,
778 issue RSET, because some servers accept only one recipient after MAIL
781 Before doing this, set the result in the domain cache record to "accept",
782 unless its previous value was ccache_reject_mfnull. In that case, the domain
783 rejects MAIL FROM:<> and we want to continue to remember that. When that is
784 the case, we have got here only in the case of a recipient verification with
785 a non-null sender. */
789 new_domain_record.result =
790 (old_domain_cache_result == ccache_reject_mfnull)?
791 ccache_reject_mfnull: ccache_accept;
793 /* Do the random local part check first */
795 if (random_local_part != NULL)
797 uschar randombuffer[1024];
799 smtp_write_command(&outblock, FALSE,
800 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
801 addr->domain) >= 0 &&
802 smtp_read_response(&inblock, randombuffer,
803 sizeof(randombuffer), '2', callout);
805 /* Remember when we last did a random test */
807 new_domain_record.random_stamp = time(NULL);
809 /* If accepted, we aren't going to do any further tests below. */
813 new_domain_record.random_result = ccache_accept;
816 /* Otherwise, cache a real negative response, and get back to the right
817 state to send RCPT. Unless there's some problem such as a dropped
818 connection, we expect to succeed, because the commands succeeded above. */
822 if (randombuffer[0] == '5')
823 new_domain_record.random_result = ccache_reject;
826 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
827 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
830 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
831 from_address) >= 0 &&
832 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
835 else done = FALSE; /* Some timeout/connection problem */
838 /* If the host is accepting all local parts, as determined by the "random"
839 check, we don't need to waste time doing any further checking. */
841 if (new_domain_record.random_result != ccache_accept && done)
843 /* Get the rcpt_include_affixes flag from the transport if there is one,
844 but assume FALSE if there is not. */
847 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
848 transport_rcpt_address(addr,
849 (addr->transport == NULL)? FALSE :
850 addr->transport->rcpt_include_affixes)) >= 0 &&
851 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
855 new_address_record.result = ccache_accept;
856 else if (errno == 0 && responsebuffer[0] == '5')
858 *failure_ptr = US"recipient";
859 new_address_record.result = ccache_reject;
862 /* Do postmaster check if requested; if a full check is required, we
863 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
865 if (done && pm_mailfrom != NULL)
867 /*XXX not suitable for cutthrough - sequencing problems */
868 cutthrough_delivery= FALSE;
869 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
872 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
873 smtp_read_response(&inblock, responsebuffer,
874 sizeof(responsebuffer), '2', callout) &&
876 smtp_write_command(&outblock, FALSE,
877 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
878 smtp_read_response(&inblock, responsebuffer,
879 sizeof(responsebuffer), '2', callout) &&
881 /* First try using the current domain */
884 smtp_write_command(&outblock, FALSE,
885 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
886 smtp_read_response(&inblock, responsebuffer,
887 sizeof(responsebuffer), '2', callout)
892 /* If that doesn't work, and a full check is requested,
893 try without the domain. */
896 (options & vopt_callout_fullpm) != 0 &&
897 smtp_write_command(&outblock, FALSE,
898 "RCPT TO:<postmaster>\r\n") >= 0 &&
899 smtp_read_response(&inblock, responsebuffer,
900 sizeof(responsebuffer), '2', callout)
903 /* Sort out the cache record */
905 new_domain_record.postmaster_stamp = time(NULL);
908 new_domain_record.postmaster_result = ccache_accept;
909 else if (errno == 0 && responsebuffer[0] == '5')
911 *failure_ptr = US"postmaster";
912 setflag(addr, af_verify_pmfail);
913 new_domain_record.postmaster_result = ccache_reject;
916 } /* Random not accepted */
917 } /* MAIL FROM: accepted */
919 /* For any failure of the main check, other than a negative response, we just
920 close the connection and carry on. We can identify a negative response by the
921 fact that errno is zero. For I/O errors it will be non-zero
923 Set up different error texts for logging and for sending back to the caller
924 as an SMTP response. Log in all cases, using a one-line format. For sender
925 callouts, give a full response to the caller, but for recipient callouts,
926 don't give the IP address because this may be an internal host whose identity
927 is not to be widely broadcast. */
931 if (errno == ETIMEDOUT)
933 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
938 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
941 string_sprintf("response to \"%s\" from %s [%s] was: %s",
942 big_buffer, host->name, host->address,
943 string_printing(responsebuffer));
945 addr->user_message = is_recipient?
946 string_sprintf("Callout verification failed:\n%s", responsebuffer)
948 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
949 host->address, big_buffer, responsebuffer);
951 /* Hard rejection ends the process */
953 if (responsebuffer[0] == '5') /* Address rejected */
961 /* End the SMTP conversation and close the connection. */
963 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
964 and we have no cutthrough conn so far
965 here is where we want to leave the conn open */
966 if ( cutthrough_delivery
969 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
970 && !random_local_part
975 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
976 cutthrough_addr = *addr; /* Save the address_item for later logging */
977 cutthrough_addr.next = NULL;
978 cutthrough_addr.host_used = store_get(sizeof(host_item));
979 cutthrough_addr.host_used->name = host->name;
980 cutthrough_addr.host_used->address = host->address;
981 cutthrough_addr.host_used->port = port;
983 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
984 ctblock.buffer = ctbuffer;
985 ctblock.buffersize = sizeof(ctbuffer);
986 ctblock.ptr = ctbuffer;
987 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
988 ctblock.sock = cutthrough_fd;
992 /* Ensure no cutthrough on multiple address verifies */
993 if (options & vopt_callout_recipsender)
994 cancel_cutthrough_connection("multiple verify calls");
995 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
998 tls_close(FALSE, TRUE);
1000 (void)close(inblock.sock);
1003 } /* Loop through all hosts, while !done */
1006 /* If we get here with done == TRUE, a successful callout happened, and yield
1007 will be set OK or FAIL according to the response to the RCPT command.
1008 Otherwise, we looped through the hosts but couldn't complete the business.
1009 However, there may be domain-specific information to cache in both cases.
1011 The value of the result field in the new_domain record is ccache_unknown if
1012 there was an error before or with MAIL FROM:, and errno was not zero,
1013 implying some kind of I/O error. We don't want to write the cache in that case.
1014 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1016 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1018 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1021 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1025 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1026 (int)sizeof(dbdata_callout_cache));
1027 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1028 " result=%d postmaster=%d random=%d\n",
1029 new_domain_record.result,
1030 new_domain_record.postmaster_result,
1031 new_domain_record.random_result);
1035 /* If a definite result was obtained for the callout, cache it unless caching
1040 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1042 if (dbm_file == NULL)
1043 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1044 if (dbm_file == NULL)
1046 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1050 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1051 (int)sizeof(dbdata_callout_cache_address));
1052 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1053 (new_address_record.result == ccache_accept)? "positive" : "negative");
1058 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1059 temporary error. If there was only one host, and a response was received, leave
1060 it alone if supplying details. Otherwise, give a generic response. */
1064 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1065 is_recipient? "recipient" : "sender");
1068 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1070 addr->user_message = (!smtp_return_error_details)? dullmsg :
1071 string_sprintf("%s for <%s>.\n"
1072 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1073 "they may be permanently unreachable from this server. In the latter case,\n%s",
1074 dullmsg, addr->address,
1076 "the address will never be accepted."
1078 "you need to change the address or create an MX record for its domain\n"
1079 "if it is supposed to be generally accessible from the Internet.\n"
1080 "Talk to your mail administrator for details.");
1082 /* Force a specific error code */
1084 addr->basic_errno = ERRNO_CALLOUTDEFER;
1087 /* Come here from within the cache-reading code on fast-track exit. */
1090 if (dbm_file != NULL) dbfn_close(dbm_file);
1096 /* Called after recipient-acl to get a cutthrough connection open when
1097 one was requested and a recipient-verify wasn't subsequently done.
1100 open_cutthrough_connection( address_item * addr )
1104 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1105 /* We must use a copy of the address for verification, because it might
1109 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1110 (void) verify_address(&addr2, NULL,
1111 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1112 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1114 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1120 /* Send given number of bytes from the buffer */
1122 cutthrough_send(int n)
1124 if(cutthrough_fd < 0)
1129 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1131 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1134 transport_count += n;
1135 ctblock.ptr= ctblock.buffer;
1139 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1146 _cutthrough_puts(uschar * cp, int n)
1150 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1151 if(!cutthrough_send(ctblock.buffersize))
1154 *ctblock.ptr++ = *cp++;
1159 /* Buffered output of counted data block. Return boolean success */
1161 cutthrough_puts(uschar * cp, int n)
1163 if (cutthrough_fd < 0) return TRUE;
1164 if (_cutthrough_puts(cp, n)) return TRUE;
1165 cancel_cutthrough_connection("transmit failed");
1171 _cutthrough_flush_send( void )
1173 int n= ctblock.ptr-ctblock.buffer;
1176 if(!cutthrough_send(n))
1182 /* Send out any bufferred output. Return boolean success. */
1184 cutthrough_flush_send( void )
1186 if (_cutthrough_flush_send()) return TRUE;
1187 cancel_cutthrough_connection("transmit failed");
1193 cutthrough_put_nl( void )
1195 return cutthrough_puts(US"\r\n", 2);
1199 /* Get and check response from cutthrough target */
1201 cutthrough_response(char expect, uschar ** copy)
1203 smtp_inblock inblock;
1204 uschar inbuffer[4096];
1205 uschar responsebuffer[4096];
1207 inblock.buffer = inbuffer;
1208 inblock.buffersize = sizeof(inbuffer);
1209 inblock.ptr = inbuffer;
1210 inblock.ptrend = inbuffer;
1211 inblock.sock = cutthrough_fd;
1212 /* this relies on (inblock.sock == tls_out.active) */
1213 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1214 cancel_cutthrough_connection("target timeout on read");
1219 *copy= cp= string_copy(responsebuffer);
1220 /* Trim the trailing end of line */
1221 cp += Ustrlen(responsebuffer);
1222 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1223 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1226 return responsebuffer[0];
1230 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1232 cutthrough_predata( void )
1234 if(cutthrough_fd < 0)
1237 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1238 cutthrough_puts(US"DATA\r\n", 6);
1239 cutthrough_flush_send();
1241 /* Assume nothing buffered. If it was it gets ignored. */
1242 return cutthrough_response('3', NULL) == '3';
1246 /* fd and use_crlf args only to match write_chunk() */
1248 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1251 while(s && (s2 = Ustrchr(s, '\n')))
1253 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1261 /* Buffered send of headers. Return success boolean. */
1262 /* Expands newlines to wire format (CR,NL). */
1263 /* Also sends header-terminating blank line. */
1265 cutthrough_headers_send( void )
1267 if(cutthrough_fd < 0)
1270 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1271 but having a separate buffered-output function (for now)
1273 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1275 if (!transport_headers_send(&cutthrough_addr, cutthrough_fd,
1276 cutthrough_addr.transport->add_headers, cutthrough_addr.transport->remove_headers,
1277 &cutthrough_write_chunk, TRUE,
1278 cutthrough_addr.transport->rewrite_rules, cutthrough_addr.transport->rewrite_existflags))
1281 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1287 close_cutthrough_connection( const char * why )
1289 if(cutthrough_fd >= 0)
1291 /* We could be sending this after a bunch of data, but that is ok as
1292 the only way to cancel the transfer in dataphase is to drop the tcp
1293 conn before the final dot.
1295 ctblock.ptr = ctbuffer;
1296 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1297 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1298 _cutthrough_flush_send();
1299 /* No wait for response */
1302 tls_close(FALSE, TRUE);
1304 (void)close(cutthrough_fd);
1306 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1308 ctblock.ptr = ctbuffer;
1312 cancel_cutthrough_connection( const char * why )
1314 close_cutthrough_connection(why);
1315 cutthrough_delivery= FALSE;
1321 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1322 Log an OK response as a transmission.
1323 Close the connection.
1324 Return smtp response-class digit.
1327 cutthrough_finaldot( void )
1329 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1331 /* Assume data finshed with new-line */
1332 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1333 return cutthrough_addr.message;
1335 switch(cutthrough_response('2', &cutthrough_addr.message))
1338 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1339 close_cutthrough_connection("delivered");
1343 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1347 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1353 return cutthrough_addr.message;
1358 /*************************************************
1359 * Copy error to toplevel address *
1360 *************************************************/
1362 /* This function is used when a verify fails or defers, to ensure that the
1363 failure or defer information is in the original toplevel address. This applies
1364 when an address is redirected to a single new address, and the failure or
1365 deferral happens to the child address.
1368 vaddr the verify address item
1369 addr the final address item
1372 Returns: the value of YIELD
1376 copy_error(address_item *vaddr, address_item *addr, int yield)
1380 vaddr->message = addr->message;
1381 vaddr->user_message = addr->user_message;
1382 vaddr->basic_errno = addr->basic_errno;
1383 vaddr->more_errno = addr->more_errno;
1384 vaddr->p.address_data = addr->p.address_data;
1385 copyflag(vaddr, addr, af_pass_message);
1393 /**************************************************
1394 * printf that automatically handles TLS if needed *
1395 ***************************************************/
1397 /* This function is used by verify_address() as a substitute for all fprintf()
1398 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1399 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1400 that assumes that we always use the smtp_out FILE* when not using TLS or the
1401 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1402 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1406 f the candidate FILE* to write to
1407 format format string
1408 ... optional arguments
1414 static void PRINTF_FUNCTION(2,3)
1415 respond_printf(FILE *f, const char *format, ...)
1419 va_start(ap, format);
1420 if (smtp_out && (f == smtp_out))
1421 smtp_vprintf(format, ap);
1423 vfprintf(f, format, ap);
1429 /*************************************************
1430 * Verify an email address *
1431 *************************************************/
1433 /* This function is used both for verification (-bv and at other times) and
1434 address testing (-bt), which is indicated by address_test_mode being set.
1437 vaddr contains the address to verify; the next field in this block
1439 f if not NULL, write the result to this file
1440 options various option bits:
1441 vopt_fake_sender => this sender verify is not for the real
1442 sender (it was verify=sender=xxxx or an address from a
1443 header line) - rewriting must not change sender_address
1444 vopt_is_recipient => this is a recipient address, otherwise
1445 it's a sender address - this affects qualification and
1446 rewriting and messages from callouts
1447 vopt_qualify => qualify an unqualified address; else error
1448 vopt_expn => called from SMTP EXPN command
1449 vopt_success_on_redirect => when a new address is generated
1450 the verification instantly succeeds
1452 These ones are used by do_callout() -- the options variable
1455 vopt_callout_fullpm => if postmaster check, do full one
1456 vopt_callout_no_cache => don't use callout cache
1457 vopt_callout_random => do the "random" thing
1458 vopt_callout_recipsender => use real sender for recipient
1459 vopt_callout_recippmaster => use postmaster for recipient
1461 callout if > 0, specifies that callout is required, and gives timeout
1462 for individual commands
1463 callout_overall if > 0, gives overall timeout for the callout function;
1464 if < 0, a default is used (see do_callout())
1465 callout_connect the connection timeout for callouts
1466 se_mailfrom when callout is requested to verify a sender, use this
1467 in MAIL FROM; NULL => ""
1468 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1469 thing and use this as the sender address (may be "")
1471 routed if not NULL, set TRUE if routing succeeded, so we can
1472 distinguish between routing failed and callout failed
1474 Returns: OK address verified
1475 FAIL address failed to verify
1476 DEFER can't tell at present
1480 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1481 int callout_overall, int callout_connect, uschar *se_mailfrom,
1482 uschar *pm_mailfrom, BOOL *routed)
1485 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1486 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1487 BOOL expn = (options & vopt_expn) != 0;
1488 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1491 int verify_type = expn? v_expn :
1492 address_test_mode? v_none :
1493 is_recipient? v_recipient : v_sender;
1494 address_item *addr_list;
1495 address_item *addr_new = NULL;
1496 address_item *addr_remote = NULL;
1497 address_item *addr_local = NULL;
1498 address_item *addr_succeed = NULL;
1499 uschar **failure_ptr = is_recipient?
1500 &recipient_verify_failure : &sender_verify_failure;
1501 uschar *ko_prefix, *cr;
1502 uschar *address = vaddr->address;
1503 uschar *save_sender;
1504 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1506 /* Clear, just in case */
1508 *failure_ptr = NULL;
1510 /* Set up a prefix and suffix for error message which allow us to use the same
1511 output statements both in EXPN mode (where an SMTP response is needed) and when
1512 debugging with an output file. */
1516 ko_prefix = US"553 ";
1519 else ko_prefix = cr = US"";
1521 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1523 if (parse_find_at(address) == NULL)
1525 if ((options & vopt_qualify) == 0)
1528 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1529 ko_prefix, address, cr);
1530 *failure_ptr = US"qualify";
1533 address = rewrite_address_qualify(address, is_recipient);
1538 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1539 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1542 /* Rewrite and report on it. Clear the domain and local part caches - these
1543 may have been set by domains and local part tests during an ACL. */
1545 if (global_rewrite_rules != NULL)
1547 uschar *old = address;
1548 address = rewrite_address(address, is_recipient, FALSE,
1549 global_rewrite_rules, rewrite_existflags);
1552 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1553 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1554 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1558 /* If this is the real sender address, we must update sender_address at
1559 this point, because it may be referred to in the routers. */
1561 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1562 sender_address = address;
1564 /* If the address was rewritten to <> no verification can be done, and we have
1565 to return OK. This rewriting is permitted only for sender addresses; for other
1566 addresses, such rewriting fails. */
1568 if (address[0] == 0) return OK;
1570 /* Flip the legacy TLS-related variables over to the outbound set in case
1571 they're used in the context of a transport used by verification. Reset them
1572 at exit from this routine. */
1574 tls_modify_variables(&tls_out);
1576 /* Save a copy of the sender address for re-instating if we change it to <>
1577 while verifying a sender address (a nice bit of self-reference there). */
1579 save_sender = sender_address;
1581 /* Update the address structure with the possibly qualified and rewritten
1582 address. Set it up as the starting address on the chain of new addresses. */
1584 vaddr->address = address;
1587 /* We need a loop, because an address can generate new addresses. We must also
1588 cope with generated pipes and files at the top level. (See also the code and
1589 comment in deliver.c.) However, it is usually the case that the router for
1590 user's .forward files has its verify flag turned off.
1592 If an address generates more than one child, the loop is used only when
1593 full_info is set, and this can only be set locally. Remote enquiries just get
1594 information about the top level address, not anything that it generated. */
1596 while (addr_new != NULL)
1599 address_item *addr = addr_new;
1601 addr_new = addr->next;
1606 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1607 debug_printf("Considering %s\n", addr->address);
1610 /* Handle generated pipe, file or reply addresses. We don't get these
1611 when handling EXPN, as it does only one level of expansion. */
1613 if (testflag(addr, af_pfr))
1620 if (addr->address[0] == '>')
1622 allow = testflag(addr, af_allow_reply);
1623 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1627 allow = (addr->address[0] == '|')?
1628 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1629 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1632 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1633 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1634 "%s\n", addr->message);
1636 fprintf(f, "\n transport = %s\n", addr->transport->name);
1638 fprintf(f, " *** forbidden ***\n");
1643 /* Just in case some router parameter refers to it. */
1645 return_path = (addr->p.errors_address != NULL)?
1646 addr->p.errors_address : sender_address;
1648 /* Split the address into domain and local part, handling the %-hack if
1649 necessary, and then route it. While routing a sender address, set
1650 $sender_address to <> because that is what it will be if we were trying to
1651 send a bounce to the sender. */
1653 if (routed != NULL) *routed = FALSE;
1654 if ((rc = deliver_split_address(addr)) == OK)
1656 if (!is_recipient) sender_address = null_sender;
1657 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1658 &addr_succeed, verify_type);
1659 sender_address = save_sender; /* Put back the real sender */
1662 /* If routing an address succeeded, set the flag that remembers, for use when
1663 an ACL cached a sender verify (in case a callout fails). Then if routing set
1664 up a list of hosts or the transport has a host list, and the callout option
1665 is set, and we aren't in a host checking run, do the callout verification,
1666 and set another flag that notes that a callout happened. */
1670 if (routed != NULL) *routed = TRUE;
1673 host_item *host_list = addr->host_list;
1675 /* Make up some data for use in the case where there is no remote
1678 transport_feedback tf = {
1679 NULL, /* interface (=> any) */
1680 US"smtp", /* port */
1681 US"smtp", /* protocol */
1683 US"$smtp_active_hostname", /* helo_data */
1684 FALSE, /* hosts_override */
1685 FALSE, /* hosts_randomize */
1686 FALSE, /* gethostbyname */
1687 TRUE, /* qualify_single */
1688 FALSE /* search_parents */
1691 /* If verification yielded a remote transport, we want to use that
1692 transport's options, so as to mimic what would happen if we were really
1693 sending a message to this address. */
1695 if (addr->transport != NULL && !addr->transport->info->local)
1697 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1699 /* If the transport has hosts and the router does not, or if the
1700 transport is configured to override the router's hosts, we must build a
1701 host list of the transport's hosts, and find the IP addresses */
1703 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1706 uschar *save_deliver_domain = deliver_domain;
1707 uschar *save_deliver_localpart = deliver_localpart;
1709 host_list = NULL; /* Ignore the router's hosts */
1711 deliver_domain = addr->domain;
1712 deliver_localpart = addr->local_part;
1713 s = expand_string(tf.hosts);
1714 deliver_domain = save_deliver_domain;
1715 deliver_localpart = save_deliver_localpart;
1719 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1720 "\"%s\" in %s transport for callout: %s", tf.hosts,
1721 addr->transport->name, expand_string_message);
1726 uschar *canonical_name;
1727 host_item *host, *nexthost;
1728 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1730 /* Just ignore failures to find a host address. If we don't manage
1731 to find any addresses, the callout will defer. Note that more than
1732 one address may be found for a single host, which will result in
1733 additional host items being inserted into the chain. Hence we must
1734 save the next host first. */
1736 flags = HOST_FIND_BY_A;
1737 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1738 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1740 for (host = host_list; host != NULL; host = nexthost)
1742 nexthost = host->next;
1743 if (tf.gethostbyname ||
1744 string_is_ip_address(host->name, NULL) != 0)
1745 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1748 uschar * d_request = NULL, * d_require = NULL;
1749 if (Ustrcmp(addr->transport->driver_name, "smtp") == 0)
1751 smtp_transport_options_block * ob =
1752 (smtp_transport_options_block *)
1753 addr->transport->options_block;
1754 d_request = ob->dnssec_request_domains;
1755 d_require = ob->dnssec_require_domains;
1758 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1759 d_request, d_require, &canonical_name, NULL);
1766 /* Can only do a callout if we have at least one host! If the callout
1767 fails, it will have set ${sender,recipient}_verify_failure. */
1769 if (host_list != NULL)
1771 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1772 if (host_checking && !host_checking_callout)
1775 debug_printf("... callout omitted by default when host testing\n"
1776 "(Use -bhc if you want the callouts to happen.)\n");
1781 deliver_set_expansions(addr);
1783 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1784 callout_connect, options, se_mailfrom, pm_mailfrom);
1789 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1790 "transport provided a host list\n");
1795 /* Otherwise, any failure is a routing failure */
1797 else *failure_ptr = US"route";
1799 /* A router may return REROUTED if it has set up a child address as a result
1800 of a change of domain name (typically from widening). In this case we always
1801 want to continue to verify the new child. */
1803 if (rc == REROUTED) continue;
1805 /* Handle hard failures */
1812 address_item *p = addr->parent;
1814 respond_printf(f, "%s%s %s", ko_prefix,
1815 full_info? addr->address : address,
1816 address_test_mode? "is undeliverable" : "failed to verify");
1817 if (!expn && admin_user)
1819 if (addr->basic_errno > 0)
1820 respond_printf(f, ": %s", strerror(addr->basic_errno));
1821 if (addr->message != NULL)
1822 respond_printf(f, ": %s", addr->message);
1825 /* Show parents iff doing full info */
1827 if (full_info) while (p != NULL)
1829 respond_printf(f, "%s\n <-- %s", cr, p->address);
1832 respond_printf(f, "%s\n", cr);
1834 cancel_cutthrough_connection("routing hard fail");
1838 yield = copy_error(vaddr, addr, FAIL);
1846 else if (rc == DEFER)
1851 address_item *p = addr->parent;
1852 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1853 full_info? addr->address : address);
1854 if (!expn && admin_user)
1856 if (addr->basic_errno > 0)
1857 respond_printf(f, ": %s", strerror(addr->basic_errno));
1858 if (addr->message != NULL)
1859 respond_printf(f, ": %s", addr->message);
1860 else if (addr->basic_errno <= 0)
1861 respond_printf(f, ": unknown error");
1864 /* Show parents iff doing full info */
1866 if (full_info) while (p != NULL)
1868 respond_printf(f, "%s\n <-- %s", cr, p->address);
1871 respond_printf(f, "%s\n", cr);
1873 cancel_cutthrough_connection("routing soft fail");
1877 yield = copy_error(vaddr, addr, DEFER);
1880 else if (yield == OK) yield = DEFER;
1883 /* If we are handling EXPN, we do not want to continue to route beyond
1884 the top level (whose address is in "address"). */
1888 uschar *ok_prefix = US"250-";
1889 if (addr_new == NULL)
1891 if (addr_local == NULL && addr_remote == NULL)
1892 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1894 respond_printf(f, "250 <%s>\r\n", address);
1896 else while (addr_new != NULL)
1898 address_item *addr2 = addr_new;
1899 addr_new = addr2->next;
1900 if (addr_new == NULL) ok_prefix = US"250 ";
1901 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1907 /* Successful routing other than EXPN. */
1911 /* Handle successful routing when short info wanted. Otherwise continue for
1912 other (generated) addresses. Short info is the operational case. Full info
1913 can be requested only when debug_selector != 0 and a file is supplied.
1915 There is a conflict between the use of aliasing as an alternate email
1916 address, and as a sort of mailing list. If an alias turns the incoming
1917 address into just one address (e.g. J.Caesar->jc44) you may well want to
1918 carry on verifying the generated address to ensure it is valid when
1919 checking incoming mail. If aliasing generates multiple addresses, you
1920 probably don't want to do this. Exim therefore treats the generation of
1921 just a single new address as a special case, and continues on to verify the
1922 generated address. */
1924 if (!full_info && /* Stop if short info wanted AND */
1925 (((addr_new == NULL || /* No new address OR */
1926 addr_new->next != NULL || /* More than one new address OR */
1927 testflag(addr_new, af_pfr))) /* New address is pfr */
1929 (addr_new != NULL && /* At least one new address AND */
1930 success_on_redirect))) /* success_on_redirect is set */
1932 if (f != NULL) fprintf(f, "%s %s\n", address,
1933 address_test_mode? "is deliverable" : "verified");
1935 /* If we have carried on to verify a child address, we want the value
1936 of $address_data to be that of the child */
1938 vaddr->p.address_data = addr->p.address_data;
1943 } /* Loop for generated addresses */
1945 /* Display the full results of the successful routing, including any generated
1946 addresses. Control gets here only when full_info is set, which requires f not
1947 to be NULL, and this occurs only when a top-level verify is called with the
1948 debugging switch on.
1950 If there are no local and no remote addresses, and there were no pipes, files,
1951 or autoreplies, and there were no errors or deferments, the message is to be
1952 discarded, usually because of the use of :blackhole: in an alias file. */
1954 if (allok && addr_local == NULL && addr_remote == NULL)
1956 fprintf(f, "mail to %s is discarded\n", address);
1960 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1962 while (addr_list != NULL)
1964 address_item *addr = addr_list;
1965 address_item *p = addr->parent;
1966 addr_list = addr->next;
1968 fprintf(f, "%s", CS addr->address);
1969 #ifdef EXPERIMENTAL_SRS
1970 if(addr->p.srs_sender)
1971 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1974 /* If the address is a duplicate, show something about it. */
1976 if (!testflag(addr, af_pfr))
1979 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1980 fprintf(f, " [duplicate, would not be delivered]");
1981 else tree_add_duplicate(addr->unique, addr);
1984 /* Now show its parents */
1988 fprintf(f, "\n <-- %s", p->address);
1993 /* Show router, and transport */
1995 fprintf(f, "router = %s, ", addr->router->name);
1996 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1997 addr->transport->name);
1999 /* Show any hosts that are set up by a router unless the transport
2000 is going to override them; fiddle a bit to get a nice format. */
2002 if (addr->host_list != NULL && addr->transport != NULL &&
2003 !addr->transport->overrides_hosts)
2008 for (h = addr->host_list; h != NULL; h = h->next)
2010 int len = Ustrlen(h->name);
2011 if (len > maxlen) maxlen = len;
2012 len = (h->address != NULL)? Ustrlen(h->address) : 7;
2013 if (len > maxaddlen) maxaddlen = len;
2015 for (h = addr->host_list; h != NULL; h = h->next)
2017 int len = Ustrlen(h->name);
2018 fprintf(f, " host %s ", h->name);
2019 while (len++ < maxlen) fprintf(f, " ");
2020 if (h->address != NULL)
2022 fprintf(f, "[%s] ", h->address);
2023 len = Ustrlen(h->address);
2025 else if (!addr->transport->info->local) /* Omit [unknown] for local */
2027 fprintf(f, "[unknown] ");
2031 while (len++ < maxaddlen) fprintf(f," ");
2032 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
2033 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2034 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2041 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2042 the -bv or -bt case). */
2045 tls_modify_variables(&tls_in);
2053 /*************************************************
2054 * Check headers for syntax errors *
2055 *************************************************/
2057 /* This function checks those header lines that contain addresses, and verifies
2058 that all the addresses therein are syntactially correct.
2061 msgptr where to put an error message
2068 verify_check_headers(uschar **msgptr)
2074 for (h = header_list; h != NULL && yield == OK; h = h->next)
2076 if (h->type != htype_from &&
2077 h->type != htype_reply_to &&
2078 h->type != htype_sender &&
2079 h->type != htype_to &&
2080 h->type != htype_cc &&
2081 h->type != htype_bcc)
2084 colon = Ustrchr(h->text, ':');
2086 while (isspace(*s)) s++;
2088 /* Loop for multiple addresses in the header, enabling group syntax. Note
2089 that we have to reset this after the header has been scanned. */
2091 parse_allow_group = TRUE;
2095 uschar *ss = parse_find_address_end(s, FALSE);
2096 uschar *recipient, *errmess;
2097 int terminator = *ss;
2098 int start, end, domain;
2100 /* Temporarily terminate the string at this point, and extract the
2101 operative address within, allowing group syntax. */
2104 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2107 /* Permit an unqualified address only if the message is local, or if the
2108 sending host is configured to be permitted to send them. */
2110 if (recipient != NULL && domain == 0)
2112 if (h->type == htype_from || h->type == htype_sender)
2114 if (!allow_unqualified_sender) recipient = NULL;
2118 if (!allow_unqualified_recipient) recipient = NULL;
2120 if (recipient == NULL) errmess = US"unqualified address not permitted";
2123 /* It's an error if no address could be extracted, except for the special
2124 case of an empty address. */
2126 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2128 uschar *verb = US"is";
2133 /* Arrange not to include any white space at the end in the
2134 error message or the header name. */
2136 while (t > s && isspace(t[-1])) t--;
2137 while (tt > h->text && isspace(tt[-1])) tt--;
2139 /* Add the address that failed to the error message, since in a
2140 header with very many addresses it is sometimes hard to spot
2141 which one is at fault. However, limit the amount of address to
2142 quote - cases have been seen where, for example, a missing double
2143 quote in a humungous To: header creates an "address" that is longer
2144 than string_sprintf can handle. */
2153 *msgptr = string_printing(
2154 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2155 errmess, tt - h->text, h->text, verb, len, s));
2158 break; /* Out of address loop */
2161 /* Advance to the next address */
2163 s = ss + (terminator? 1:0);
2164 while (isspace(*s)) s++;
2165 } /* Next address */
2167 parse_allow_group = FALSE;
2168 parse_found_group = FALSE;
2169 } /* Next header unless yield has been set FALSE */
2175 /*************************************************
2176 * Check header names for 8-bit characters *
2177 *************************************************/
2179 /* This function checks for invalid charcters in header names. See
2180 RFC 5322, 2.2. and RFC 6532, 3.
2183 msgptr where to put an error message
2190 verify_check_header_names_ascii(uschar **msgptr)
2195 for (h = header_list; h != NULL; h = h->next)
2197 colon = Ustrchr(h->text, ':');
2198 for(s = h->text; s < colon; s++)
2200 if ((*s < 33) || (*s > 126))
2202 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2203 colon - h->text, h->text);
2211 /*************************************************
2212 * Check for blind recipients *
2213 *************************************************/
2215 /* This function checks that every (envelope) recipient is mentioned in either
2216 the To: or Cc: header lines, thus detecting blind carbon copies.
2218 There are two ways of scanning that could be used: either scan the header lines
2219 and tick off the recipients, or scan the recipients and check the header lines.
2220 The original proposed patch did the former, but I have chosen to do the latter,
2221 because (a) it requires no memory and (b) will use fewer resources when there
2222 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2225 Returns: OK if there are no blind recipients
2226 FAIL if there is at least one blind recipient
2230 verify_check_notblind(void)
2233 for (i = 0; i < recipients_count; i++)
2237 uschar *address = recipients_list[i].address;
2239 for (h = header_list; !found && h != NULL; h = h->next)
2243 if (h->type != htype_to && h->type != htype_cc) continue;
2245 colon = Ustrchr(h->text, ':');
2247 while (isspace(*s)) s++;
2249 /* Loop for multiple addresses in the header, enabling group syntax. Note
2250 that we have to reset this after the header has been scanned. */
2252 parse_allow_group = TRUE;
2256 uschar *ss = parse_find_address_end(s, FALSE);
2257 uschar *recipient,*errmess;
2258 int terminator = *ss;
2259 int start, end, domain;
2261 /* Temporarily terminate the string at this point, and extract the
2262 operative address within, allowing group syntax. */
2265 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2268 /* If we found a valid recipient that has a domain, compare it with the
2269 envelope recipient. Local parts are compared case-sensitively, domains
2270 case-insensitively. By comparing from the start with length "domain", we
2271 include the "@" at the end, which ensures that we are comparing the whole
2272 local part of each address. */
2274 if (recipient != NULL && domain != 0)
2276 found = Ustrncmp(recipient, address, domain) == 0 &&
2277 strcmpic(recipient + domain, address + domain) == 0;
2281 /* Advance to the next address */
2283 s = ss + (terminator? 1:0);
2284 while (isspace(*s)) s++;
2285 } /* Next address */
2287 parse_allow_group = FALSE;
2288 parse_found_group = FALSE;
2289 } /* Next header (if found is false) */
2291 if (!found) return FAIL;
2292 } /* Next recipient */
2299 /*************************************************
2300 * Find if verified sender *
2301 *************************************************/
2303 /* Usually, just a single address is verified as the sender of the message.
2304 However, Exim can be made to verify other addresses as well (often related in
2305 some way), and this is useful in some environments. There may therefore be a
2306 chain of such addresses that have previously been tested. This function finds
2307 whether a given address is on the chain.
2309 Arguments: the address to be verified
2310 Returns: pointer to an address item, or NULL
2314 verify_checked_sender(uschar *sender)
2317 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2318 if (Ustrcmp(sender, addr->address) == 0) break;
2326 /*************************************************
2327 * Get valid header address *
2328 *************************************************/
2330 /* Scan the originator headers of the message, looking for an address that
2331 verifies successfully. RFC 822 says:
2333 o The "Sender" field mailbox should be sent notices of
2334 any problems in transport or delivery of the original
2335 messages. If there is no "Sender" field, then the
2336 "From" field mailbox should be used.
2338 o If the "Reply-To" field exists, then the reply should
2339 go to the addresses indicated in that field and not to
2340 the address(es) indicated in the "From" field.
2342 So we check a Sender field if there is one, else a Reply_to field, else a From
2343 field. As some strange messages may have more than one of these fields,
2344 especially if they are resent- fields, check all of them if there is more than
2348 user_msgptr points to where to put a user error message
2349 log_msgptr points to where to put a log error message
2350 callout timeout for callout check (passed to verify_address())
2351 callout_overall overall callout timeout (ditto)
2352 callout_connect connect callout timeout (ditto)
2353 se_mailfrom mailfrom for verify; NULL => ""
2354 pm_mailfrom sender for pm callout check (passed to verify_address())
2355 options callout options (passed to verify_address())
2356 verrno where to put the address basic_errno
2358 If log_msgptr is set to something without setting user_msgptr, the caller
2359 normally uses log_msgptr for both things.
2361 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2362 FAIL is given if no appropriate headers are found
2366 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2367 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2368 uschar *pm_mailfrom, int options, int *verrno)
2370 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2375 for (i = 0; i < 3 && !done; i++)
2378 for (h = header_list; h != NULL && !done; h = h->next)
2380 int terminator, new_ok;
2381 uschar *s, *ss, *endname;
2383 if (h->type != header_types[i]) continue;
2384 s = endname = Ustrchr(h->text, ':') + 1;
2386 /* Scan the addresses in the header, enabling group syntax. Note that we
2387 have to reset this after the header has been scanned. */
2389 parse_allow_group = TRUE;
2393 address_item *vaddr;
2395 while (isspace(*s) || *s == ',') s++;
2396 if (*s == 0) break; /* End of header */
2398 ss = parse_find_address_end(s, FALSE);
2400 /* The terminator is a comma or end of header, but there may be white
2401 space preceding it (including newline for the last address). Move back
2402 past any white space so we can check against any cached envelope sender
2403 address verifications. */
2405 while (isspace(ss[-1])) ss--;
2409 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2410 (int)(endname - h->text), h->text, s);
2412 /* See if we have already verified this address as an envelope sender,
2413 and if so, use the previous answer. */
2415 vaddr = verify_checked_sender(s);
2417 if (vaddr != NULL && /* Previously checked */
2418 (callout <= 0 || /* No callout needed; OR */
2419 vaddr->special_action > 256)) /* Callout was done */
2421 new_ok = vaddr->special_action & 255;
2422 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2423 *ss = terminator; /* Restore shortened string */
2426 /* Otherwise we run the verification now. We must restore the shortened
2427 string before running the verification, so the headers are correct, in
2428 case there is any rewriting. */
2432 int start, end, domain;
2433 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2438 /* If we found an empty address, just carry on with the next one, but
2439 kill the message. */
2441 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2448 /* If verification failed because of a syntax error, fail this
2449 function, and ensure that the failing address gets added to the error
2452 if (address == NULL)
2455 while (ss > s && isspace(ss[-1])) ss--;
2456 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2457 "scanning for sender: %s in \"%.*s\"",
2458 endname - h->text, h->text, *log_msgptr, ss - s, s);
2464 /* Else go ahead with the sender verification. But it isn't *the*
2465 sender of the message, so set vopt_fake_sender to stop sender_address
2466 being replaced after rewriting or qualification. */
2470 vaddr = deliver_make_addr(address, FALSE);
2471 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2472 callout, callout_overall, callout_connect, se_mailfrom,
2477 /* We now have the result, either newly found, or cached. If we are
2478 giving out error details, set a specific user error. This means that the
2479 last of these will be returned to the user if all three fail. We do not
2480 set a log message - the generic one below will be used. */
2484 *verrno = vaddr->basic_errno;
2485 if (smtp_return_error_details)
2487 *user_msgptr = string_sprintf("Rejected after DATA: "
2488 "could not verify \"%.*s\" header address\n%s: %s",
2489 endname - h->text, h->text, vaddr->address, vaddr->message);
2493 /* Success or defer */
2502 if (new_ok == DEFER) yield = DEFER;
2504 /* Move on to any more addresses in the header */
2507 } /* Next address */
2509 parse_allow_group = FALSE;
2510 parse_found_group = FALSE;
2511 } /* Next header, unless done */
2512 } /* Next header type unless done */
2514 if (yield == FAIL && *log_msgptr == NULL)
2515 *log_msgptr = US"there is no valid sender in any header line";
2517 if (yield == DEFER && *log_msgptr == NULL)
2518 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2526 /*************************************************
2527 * Get RFC 1413 identification *
2528 *************************************************/
2530 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2531 the timeout is set to zero, then the query is not done. There may also be lists
2532 of hosts and nets which are exempt. To guard against malefactors sending
2533 non-printing characters which could, for example, disrupt a message's headers,
2534 make sure the string consists of printing characters only.
2537 port the port to connect to; usually this is IDENT_PORT (113), but when
2538 running in the test harness with -bh a different value is used.
2542 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2546 verify_get_ident(int port)
2548 int sock, host_af, qlen;
2549 int received_sender_port, received_interface_port, n;
2551 uschar buffer[2048];
2553 /* Default is no ident. Check whether we want to do an ident check for this
2556 sender_ident = NULL;
2557 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2560 DEBUG(D_ident) debug_printf("doing ident callback\n");
2562 /* Set up a connection to the ident port of the remote host. Bind the local end
2563 to the incoming interface address. If the sender host address is an IPv6
2564 address, the incoming interface address will also be IPv6. */
2566 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2567 sock = ip_socket(SOCK_STREAM, host_af);
2568 if (sock < 0) return;
2570 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2572 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2577 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2580 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2582 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2583 sender_host_address);
2587 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2588 sender_host_address, strerror(errno));
2593 /* Construct and send the query. */
2595 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2596 qlen = Ustrlen(buffer);
2597 if (send(sock, buffer, qlen, 0) < 0)
2599 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2603 /* Read a response line. We put it into the rest of the buffer, using several
2604 recv() calls if necessary. */
2612 int size = sizeof(buffer) - (p - buffer);
2614 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2615 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2616 if (count <= 0) goto END_OFF; /* Read error or EOF */
2618 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2619 generous, and accept a plain \n terminator as well. The only illegal
2622 for (pp = p; pp < p + count; pp++)
2624 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2627 if (pp[-1] == '\r') pp--;
2629 goto GOT_DATA; /* Break out of both loops */
2633 /* Reached the end of the data without finding \n. Let the loop continue to
2634 read some more, if there is room. */
2641 /* We have received a line of data. Check it carefully. It must start with the
2642 same two port numbers that we sent, followed by data as defined by the RFC. For
2645 12345 , 25 : USERID : UNIX :root
2647 However, the amount of white space may be different to what we sent. In the
2648 "osname" field there may be several sub-fields, comma separated. The data we
2649 actually want to save follows the third colon. Some systems put leading spaces
2650 in it - we discard those. */
2652 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2653 &received_interface_port, &n) != 2 ||
2654 received_sender_port != sender_host_port ||
2655 received_interface_port != interface_port)
2658 p = buffer + qlen + n;
2659 while(isspace(*p)) p++;
2660 if (*p++ != ':') goto END_OFF;
2661 while(isspace(*p)) p++;
2662 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2664 while(isspace(*p)) p++;
2665 if (*p++ != ':') goto END_OFF;
2666 while (*p != 0 && *p != ':') p++;
2667 if (*p++ == 0) goto END_OFF;
2668 while(isspace(*p)) p++;
2669 if (*p == 0) goto END_OFF;
2671 /* The rest of the line is the data we want. We turn it into printing
2672 characters when we save it, so that it cannot mess up the format of any logging
2673 or Received: lines into which it gets inserted. We keep a maximum of 127
2676 sender_ident = string_printing(string_copyn(p, 127));
2677 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2687 /*************************************************
2688 * Match host to a single host-list item *
2689 *************************************************/
2691 /* This function compares a host (name or address) against a single item
2692 from a host list. The host name gets looked up if it is needed and is not
2693 already known. The function is called from verify_check_this_host() via
2694 match_check_list(), which is why most of its arguments are in a single block.
2697 arg the argument block (see below)
2698 ss the host-list item
2699 valueptr where to pass back looked up data, or NULL
2700 error for error message when returning ERROR
2703 host_name (a) the host name, or
2704 (b) NULL, implying use sender_host_name and
2705 sender_host_aliases, looking them up if required, or
2706 (c) the empty string, meaning that only IP address matches
2708 host_address the host address
2709 host_ipv4 the IPv4 address taken from an IPv6 one
2713 DEFER lookup deferred
2714 ERROR (a) failed to find the host name or IP address, or
2715 (b) unknown lookup type specified, or
2716 (c) host name encountered when only IP addresses are
2721 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2723 check_host_block *cb = (check_host_block *)arg;
2726 BOOL iplookup = FALSE;
2727 BOOL isquery = FALSE;
2728 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2733 /* Optimize for the special case when the pattern is "*". */
2735 if (*ss == '*' && ss[1] == 0) return OK;
2737 /* If the pattern is empty, it matches only in the case when there is no host -
2738 this can occur in ACL checking for SMTP input using the -bs option. In this
2739 situation, the host address is the empty string. */
2741 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2742 if (*ss == 0) return FAIL;
2744 /* If the pattern is precisely "@" then match against the primary host name,
2745 provided that host name matching is permitted; if it's "@[]" match against the
2746 local host's IP addresses. */
2752 if (isiponly) return ERROR;
2753 ss = primary_hostname;
2755 else if (Ustrcmp(ss, "@[]") == 0)
2757 ip_address_item *ip;
2758 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2759 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2764 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2765 a (possibly masked) comparision with the current IP address. */
2767 if (string_is_ip_address(ss, &maskoffset) != 0)
2768 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2770 /* The pattern is not an IP address. A common error that people make is to omit
2771 one component of an IPv4 address, either by accident, or believing that, for
2772 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,
2773 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2774 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2775 ancient specification.) To aid in debugging these cases, we give a specific
2776 error if the pattern contains only digits and dots or contains a slash preceded
2777 only by digits and dots (a slash at the start indicates a file name and of
2778 course slashes may be present in lookups, but not preceded only by digits and
2781 for (t = ss; isdigit(*t) || *t == '.'; t++);
2782 if (*t == 0 || (*t == '/' && t != ss))
2784 *error = US"malformed IPv4 address or address mask";
2788 /* See if there is a semicolon in the pattern */
2790 semicolon = Ustrchr(ss, ';');
2792 /* If we are doing an IP address only match, then all lookups must be IP
2793 address lookups, even if there is no "net-". */
2797 iplookup = semicolon != NULL;
2800 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2801 a lookup on a masked IP network, in textual form. We obey this code even if we
2802 have already set iplookup, so as to skip over the "net-" prefix and to set the
2803 mask length. The net- stuff really only applies to single-key lookups where the
2804 key is implicit. For query-style lookups the key is specified in the query.
2805 From release 4.30, the use of net- for query style is no longer needed, but we
2806 retain it for backward compatibility. */
2808 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2811 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2812 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2813 iplookup = (*t++ == '-');
2817 /* Do the IP address lookup if that is indeed what we have */
2825 uschar *filename, *key, *result;
2828 /* Find the search type */
2830 search_type = search_findtype(t, semicolon - t);
2832 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2833 search_error_message);
2835 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2836 is no file name, and the "key" is just the query. For query-style with a file
2837 name, we have to fish the file off the start of the query. For a single-key
2838 lookup, the key is the current IP address, masked appropriately, and
2839 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2840 dot separators instead of colons, except when the lookup type is "iplsearch".
2843 if (mac_islookup(search_type, lookup_absfilequery))
2845 filename = semicolon + 1;
2847 while (*key != 0 && !isspace(*key)) key++;
2848 filename = string_copyn(filename, key - filename);
2849 while (isspace(*key)) key++;
2851 else if (mac_islookup(search_type, lookup_querystyle))
2854 key = semicolon + 1;
2856 else /* Single-key style */
2858 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2860 insize = host_aton(cb->host_address, incoming);
2861 host_mask(insize, incoming, mlen);
2862 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2864 filename = semicolon + 1;
2867 /* Now do the actual lookup; note that there is no search_close() because
2868 of the caching arrangements. */
2870 handle = search_open(filename, search_type, 0, NULL, NULL);
2871 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2872 search_error_message);
2873 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2874 if (valueptr != NULL) *valueptr = result;
2875 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2878 /* The pattern is not an IP address or network reference of any kind. That is,
2879 it is a host name pattern. If this is an IP only match, there's an error in the
2884 *error = US"cannot match host name in match_ip list";
2888 /* Check the characters of the pattern to see if they comprise only letters,
2889 digits, full stops, and hyphens (the constituents of domain names). Allow
2890 underscores, as they are all too commonly found. Sigh. Also, if
2891 allow_utf8_domains is set, allow top-bit characters. */
2893 for (t = ss; *t != 0; t++)
2894 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2895 (!allow_utf8_domains || *t < 128)) break;
2897 /* If the pattern is a complete domain name, with no fancy characters, look up
2898 its IP address and match against that. Note that a multi-homed host will add
2899 items to the chain. */
2910 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2911 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2914 for (hh = &h; hh != NULL; hh = hh->next)
2916 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2920 if (rc == HOST_FIND_AGAIN) return DEFER;
2921 *error = string_sprintf("failed to find IP address for %s", ss);
2925 /* Almost all subsequent comparisons require the host name, and can be done
2926 using the general string matching function. When this function is called for
2927 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2928 must use sender_host_name and its aliases, looking them up if necessary. */
2930 if (cb->host_name != NULL) /* Explicit host name given */
2931 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2934 /* Host name not given; in principle we need the sender host name and its
2935 aliases. However, for query-style lookups, we do not need the name if the
2936 query does not contain $sender_host_name. From release 4.23, a reference to
2937 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2940 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2943 int partial, affixlen, starflags, id;
2946 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2949 if (id < 0) /* Unknown lookup type */
2951 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2952 search_error_message, ss);
2955 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2960 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2963 case DEFER: return DEFER;
2964 default: return FAIL;
2968 /* Not a query-style lookup; must ensure the host name is present, and then we
2969 do a check on the name and all its aliases. */
2971 if (sender_host_name == NULL)
2973 HDEBUG(D_host_lookup)
2974 debug_printf("sender host name required, to match against %s\n", ss);
2975 if (host_lookup_failed || host_name_lookup() != OK)
2977 *error = string_sprintf("failed to find host name for %s",
2978 sender_host_address);;
2981 host_build_sender_fullhost();
2984 /* Match on the sender host name, using the general matching function */
2986 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2990 case DEFER: return DEFER;
2993 /* If there are aliases, try matching on them. */
2995 aliases = sender_host_aliases;
2996 while (*aliases != NULL)
2998 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3001 case DEFER: return DEFER;
3010 /*************************************************
3011 * Check a specific host matches a host list *
3012 *************************************************/
3014 /* This function is passed a host list containing items in a number of
3015 different formats and the identity of a host. Its job is to determine whether
3016 the given host is in the set of hosts defined by the list. The host name is
3017 passed as a pointer so that it can be looked up if needed and not already
3018 known. This is commonly the case when called from verify_check_host() to check
3019 an incoming connection. When called from elsewhere the host name should usually
3022 This function is now just a front end to match_check_list(), which runs common
3023 code for scanning a list. We pass it the check_host() function to perform a
3027 listptr pointer to the host list
3028 cache_bits pointer to cache for named lists, or NULL
3029 host_name the host name or NULL, implying use sender_host_name and
3030 sender_host_aliases, looking them up if required
3031 host_address the IP address
3032 valueptr if not NULL, data from a lookup is passed back here
3034 Returns: OK if the host is in the defined set
3035 FAIL if the host is not in the defined set,
3036 DEFER if a data lookup deferred (not a host lookup)
3038 If the host name was needed in order to make a comparison, and could not be
3039 determined from the IP address, the result is FAIL unless the item
3040 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3043 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
3044 uschar *host_name, uschar *host_address, uschar **valueptr)
3047 unsigned int *local_cache_bits = cache_bits;
3048 uschar *save_host_address = deliver_host_address;
3049 check_host_block cb;
3050 cb.host_name = host_name;
3051 cb.host_address = host_address;
3053 if (valueptr != NULL) *valueptr = NULL;
3055 /* If the host address starts off ::ffff: it is an IPv6 address in
3056 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3059 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3060 host_address + 7 : host_address;
3062 /* During the running of the check, put the IP address into $host_address. In
3063 the case of calls from the smtp transport, it will already be there. However,
3064 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3065 the safe side, any existing setting is preserved, though as I write this
3066 (November 2004) I can't see any cases where it is actually needed. */
3068 deliver_host_address = host_address;
3069 rc = match_check_list(
3070 listptr, /* the list */
3071 0, /* separator character */
3072 &hostlist_anchor, /* anchor pointer */
3073 &local_cache_bits, /* cache pointer */
3074 check_host, /* function for testing */
3075 &cb, /* argument for function */
3076 MCL_HOST, /* type of check */
3077 (host_address == sender_host_address)?
3078 US"host" : host_address, /* text for debugging */
3079 valueptr); /* where to pass back data */
3080 deliver_host_address = save_host_address;
3087 /*************************************************
3088 * Check the remote host matches a list *
3089 *************************************************/
3091 /* This is a front end to verify_check_this_host(), created because checking
3092 the remote host is a common occurrence. With luck, a good compiler will spot
3093 the tail recursion and optimize it. If there's no host address, this is
3094 command-line SMTP input - check against an empty string for the address.
3097 listptr pointer to the host list
3099 Returns: the yield of verify_check_this_host(),
3100 i.e. OK, FAIL, or DEFER
3104 verify_check_host(uschar **listptr)
3106 return verify_check_this_host(listptr, sender_host_cache, NULL,
3107 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3114 /*************************************************
3115 * Invert an IP address *
3116 *************************************************/
3118 /* Originally just used for DNS xBL lists, now also used for the
3119 reverse_ip expansion operator.
3122 buffer where to put the answer
3123 address the address to invert
3127 invert_address(uschar *buffer, uschar *address)
3130 uschar *bptr = buffer;
3132 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3133 to the IPv4 part only. */
3135 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3137 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3140 if (host_aton(address, bin) == 1)
3144 for (i = 0; i < 4; i++)
3146 sprintf(CS bptr, "%d.", x & 255);
3147 while (*bptr) bptr++;
3152 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3153 in any DNS black lists, and the format in which they will be looked up is
3154 unknown. This is just a guess. */
3160 for (j = 3; j >= 0; j--)
3163 for (i = 0; i < 8; i++)
3165 sprintf(CS bptr, "%x.", x & 15);
3166 while (*bptr) bptr++;
3173 /* Remove trailing period -- this is needed so that both arbitrary
3174 dnsbl keydomains and inverted addresses may be combined with the
3175 same format string, "%s.%s" */
3182 /*************************************************
3183 * Perform a single dnsbl lookup *
3184 *************************************************/
3186 /* This function is called from verify_check_dnsbl() below. It is also called
3187 recursively from within itself when domain and domain_txt are different
3188 pointers, in order to get the TXT record from the alternate domain.
3191 domain the outer dnsbl domain
3192 domain_txt alternate domain to lookup TXT record on success; when the
3193 same domain is to be used, domain_txt == domain (that is,
3194 the pointers must be identical, not just the text)
3195 keydomain the current keydomain (for debug message)
3196 prepend subdomain to lookup (like keydomain, but
3197 reversed if IP address)
3198 iplist the list of matching IP addresses, or NULL for "any"
3199 bitmask true if bitmask matching is wanted
3200 match_type condition for 'succeed' result
3201 0 => Any RR in iplist (=)
3202 1 => No RR in iplist (!=)
3203 2 => All RRs in iplist (==)
3204 3 => Some RRs not in iplist (!==)
3205 the two bits are defined as MT_NOT and MT_ALL
3206 defer_return what to return for a defer
3208 Returns: OK if lookup succeeded
3213 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3214 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3220 dnsbl_cache_block *cb;
3221 int old_pool = store_pool;
3222 uschar query[256]; /* DNS domain max length */
3224 /* Construct the specific query domainname */
3226 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3228 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3229 "(ignored): %s...", query);
3233 /* Look for this query in the cache. */
3235 t = tree_search(dnsbl_cache, query);
3237 /* If not cached from a previous lookup, we must do a DNS lookup, and
3238 cache the result in permanent memory. */
3242 store_pool = POOL_PERM;
3244 /* Set up a tree entry to cache the lookup */
3246 t = store_get(sizeof(tree_node) + Ustrlen(query));
3247 Ustrcpy(t->name, query);
3248 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3249 (void)tree_insertnode(&dnsbl_cache, t);
3251 /* Do the DNS loopup . */
3253 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3254 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3255 cb->text_set = FALSE;
3259 /* If the lookup succeeded, cache the RHS address. The code allows for
3260 more than one address - this was for complete generality and the possible
3261 use of A6 records. However, A6 records have been reduced to experimental
3262 status (August 2001) and may die out. So they may never get used at all,
3263 let alone in dnsbl records. However, leave the code here, just in case.
3265 Quite apart from one A6 RR generating multiple addresses, there are DNS
3266 lists that return more than one A record, so we must handle multiple
3267 addresses generated in that way as well. */
3269 if (cb->rc == DNS_SUCCEED)
3272 dns_address **addrp = &(cb->rhs);
3273 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3275 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3277 if (rr->type == T_A)
3279 dns_address *da = dns_address_from_rr(&dnsa, rr);
3283 while (da->next != NULL) da = da->next;
3284 addrp = &(da->next);
3289 /* If we didn't find any A records, change the return code. This can
3290 happen when there is a CNAME record but there are no A records for what
3293 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3296 store_pool = old_pool;
3299 /* Previous lookup was cached */
3303 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3307 /* We now have the result of the DNS lookup, either newly done, or cached
3308 from a previous call. If the lookup succeeded, check against the address
3309 list if there is one. This may be a positive equality list (introduced by
3310 "="), a negative equality list (introduced by "!="), a positive bitmask
3311 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3313 if (cb->rc == DNS_SUCCEED)
3315 dns_address *da = NULL;
3316 uschar *addlist = cb->rhs->address;
3318 /* For A and AAAA records, there may be multiple addresses from multiple
3319 records. For A6 records (currently not expected to be used) there may be
3320 multiple addresses from a single record. */
3322 for (da = cb->rhs->next; da != NULL; da = da->next)
3323 addlist = string_sprintf("%s, %s", addlist, da->address);
3325 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3328 /* Address list check; this can be either for equality, or via a bitmask.
3329 In the latter case, all the bits must match. */
3333 for (da = cb->rhs; da != NULL; da = da->next)
3337 uschar *ptr = iplist;
3340 /* Handle exact matching */
3344 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3346 if (Ustrcmp(CS da->address, ip) == 0) break;
3350 /* Handle bitmask matching */
3357 /* At present, all known DNS blocking lists use A records, with
3358 IPv4 addresses on the RHS encoding the information they return. I
3359 wonder if this will linger on as the last vestige of IPv4 when IPv6
3360 is ubiquitous? Anyway, for now we use paranoia code to completely
3361 ignore IPv6 addresses. The default mask is 0, which always matches.
3362 We change this only for IPv4 addresses in the list. */
3364 if (host_aton(da->address, address) == 1) mask = address[0];
3366 /* Scan the returned addresses, skipping any that are IPv6 */
3368 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3370 if (host_aton(ip, address) != 1) continue;
3371 if ((address[0] & mask) == address[0]) break;
3377 (a) An IP address in an any ('=') list matched, or
3378 (b) No IP address in an all ('==') list matched
3380 then we're done searching. */
3382 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3385 /* If da == NULL, either
3387 (a) No IP address in an any ('=') list matched, or
3388 (b) An IP address in an all ('==') list didn't match
3390 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3393 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3401 res = US"was no match";
3404 res = US"was an exclude match";
3407 res = US"was an IP address that did not match";
3410 res = US"were no IP addresses that did not match";
3413 debug_printf("=> but we are not accepting this block class because\n");
3414 debug_printf("=> there %s for %s%c%s\n",
3416 ((match_type & MT_ALL) == 0)? "" : "=",
3417 bitmask? '&' : '=', iplist);
3423 /* Either there was no IP list, or the record matched, implying that the
3424 domain is on the list. We now want to find a corresponding TXT record. If an
3425 alternate domain is specified for the TXT record, call this function
3426 recursively to look that up; this has the side effect of re-checking that
3427 there is indeed an A record at the alternate domain. */
3429 if (domain_txt != domain)
3430 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3431 FALSE, match_type, defer_return);
3433 /* If there is no alternate domain, look up a TXT record in the main domain
3434 if it has not previously been cached. */
3438 cb->text_set = TRUE;
3439 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3442 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3444 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3445 if (rr->type == T_TXT) break;
3448 int len = (rr->data)[0];
3449 if (len > 511) len = 127;
3450 store_pool = POOL_PERM;
3451 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3452 store_pool = old_pool;
3457 dnslist_value = addlist;
3458 dnslist_text = cb->text;
3462 /* There was a problem with the DNS lookup */
3464 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3466 log_write(L_dnslist_defer, LOG_MAIN,
3467 "DNS list lookup defer (probably timeout) for %s: %s", query,
3468 (defer_return == OK)? US"assumed in list" :
3469 (defer_return == FAIL)? US"assumed not in list" :
3470 US"returned DEFER");
3471 return defer_return;
3474 /* No entry was found in the DNS; continue for next domain */
3478 debug_printf("DNS lookup for %s failed\n", query);
3479 debug_printf("=> that means %s is not listed at %s\n",
3489 /*************************************************
3490 * Check host against DNS black lists *
3491 *************************************************/
3493 /* This function runs checks against a list of DNS black lists, until one
3494 matches. Each item on the list can be of the form
3496 domain=ip-address/key
3498 The domain is the right-most domain that is used for the query, for example,
3499 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3500 if the DNS lookup returns a matching IP address. Several addresses may be
3501 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3503 If no key is given, what is looked up in the domain is the inverted IP address
3504 of the current client host. If a key is given, it is used to construct the
3505 domain for the lookup. For example:
3507 dsn.rfc-ignorant.org/$sender_address_domain
3509 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3510 then we check for a TXT record for an error message, and if found, save its
3511 value in $dnslist_text. We also cache everything in a tree, to optimize
3514 The TXT record is normally looked up in the same domain as the A record, but
3515 when many lists are combined in a single DNS domain, this will not be a very
3516 specific message. It is possible to specify a different domain for looking up
3517 TXT records; this is given before the main domain, comma-separated. For
3520 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3521 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3523 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3525 Note: an address for testing RBL is 192.203.178.39
3526 Note: an address for testing DUL is 192.203.178.4
3527 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3530 listptr the domain/address/data list
3532 Returns: OK successful lookup (i.e. the address is on the list), or
3533 lookup deferred after +include_unknown
3534 FAIL name not found, or no data found for the given type, or
3535 lookup deferred after +exclude_unknown (default)
3536 DEFER lookup failure, if +defer_unknown was set
3540 verify_check_dnsbl(uschar **listptr)
3543 int defer_return = FAIL;
3544 uschar *list = *listptr;
3547 uschar buffer[1024];
3548 uschar revadd[128]; /* Long enough for IPv6 address */
3550 /* Indicate that the inverted IP address is not yet set up */
3554 /* In case this is the first time the DNS resolver is being used. */
3556 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3558 /* Loop through all the domains supplied, until something matches */
3560 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3563 BOOL bitmask = FALSE;
3570 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3572 /* Deal with special values that change the behaviour on defer */
3574 if (domain[0] == '+')
3576 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3577 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3578 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3580 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3585 /* See if there's explicit data to be looked up */
3587 key = Ustrchr(domain, '/');
3588 if (key != NULL) *key++ = 0;
3590 /* See if there's a list of addresses supplied after the domain name. This is
3591 introduced by an = or a & character; if preceded by = we require all matches
3592 and if preceded by ! we invert the result. */
3594 iplist = Ustrchr(domain, '=');
3598 iplist = Ustrchr(domain, '&');
3601 if (iplist != NULL) /* Found either = or & */
3603 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3605 match_type |= MT_NOT;
3609 *iplist++ = 0; /* Terminate domain, move on */
3611 /* If we found = (bitmask == FALSE), check for == or =& */
3613 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3615 bitmask = *iplist++ == '&';
3616 match_type |= MT_ALL;
3620 /* If there is a comma in the domain, it indicates that a second domain for
3621 looking up TXT records is provided, before the main domain. Otherwise we must
3622 set domain_txt == domain. */
3624 domain_txt = domain;
3625 comma = Ustrchr(domain, ',');
3632 /* Check that what we have left is a sensible domain name. There is no reason
3633 why these domains should in fact use the same syntax as hosts and email
3634 domains, but in practice they seem to. However, there is little point in
3635 actually causing an error here, because that would no doubt hold up incoming
3636 mail. Instead, I'll just log it. */
3638 for (s = domain; *s != 0; s++)
3640 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3642 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3643 "strange characters - is this right?", domain);
3648 /* Check the alternate domain if present */
3650 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3652 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3654 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3655 "strange characters - is this right?", domain_txt);
3660 /* If there is no key string, construct the query by adding the domain name
3661 onto the inverted host address, and perform a single DNS lookup. */
3665 if (sender_host_address == NULL) return FAIL; /* can never match */
3666 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3667 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3668 iplist, bitmask, match_type, defer_return);
3671 dnslist_domain = string_copy(domain_txt);
3672 dnslist_matched = string_copy(sender_host_address);
3673 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3674 sender_host_address, dnslist_domain);
3676 if (rc != FAIL) return rc; /* OK or DEFER */
3679 /* If there is a key string, it can be a list of domains or IP addresses to
3680 be concatenated with the main domain. */
3687 uschar keybuffer[256];
3688 uschar keyrevadd[128];
3690 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3691 sizeof(keybuffer))) != NULL)
3693 uschar *prepend = keydomain;
3695 if (string_is_ip_address(keydomain, NULL) != 0)
3697 invert_address(keyrevadd, keydomain);
3698 prepend = keyrevadd;
3701 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3702 bitmask, match_type, defer_return);
3706 dnslist_domain = string_copy(domain_txt);
3707 dnslist_matched = string_copy(keydomain);
3708 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3709 keydomain, dnslist_domain);
3713 /* If the lookup deferred, remember this fact. We keep trying the rest
3714 of the list to see if we get a useful result, and if we don't, we return
3715 DEFER at the end. */
3717 if (rc == DEFER) defer = TRUE;
3718 } /* continue with next keystring domain/address */
3720 if (defer) return DEFER;
3722 } /* continue with next dnsdb outer domain */
3729 /* End of verify.c */