1 /* $Cambridge: exim/src/src/verify.c,v 1.16 2005/04/06 16:26:42 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2005 */
8 /* See the file NOTICE for conditions of use and distribution. */
10 /* Functions concerned with verifying things. The original code for callout
11 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
17 /* Structure for caching DNSBL lookups */
19 typedef struct dnsbl_cache_block {
27 /* Anchor for DNSBL cache */
29 static tree_node *dnsbl_cache = NULL;
33 /*************************************************
34 * Retrieve a callout cache record *
35 *************************************************/
37 /* If a record exists, check whether it has expired.
40 dbm_file an open hints file
42 type "address" or "domain"
43 positive_expire expire time for positive records
44 negative_expire expire time for negative records
46 Returns: the cache record if a non-expired one exists, else NULL
49 static dbdata_callout_cache *
50 get_callout_cache_record(open_db *dbm_file, uschar *key, uschar *type,
51 int positive_expire, int negative_expire)
56 dbdata_callout_cache *cache_record;
58 cache_record = dbfn_read_with_length(dbm_file, key, &length);
60 if (cache_record == NULL)
62 HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type);
66 /* We treat a record as "negative" if its result field is not positive, or if
67 it is a domain record and the postmaster field is negative. */
69 negative = cache_record->result != ccache_accept ||
70 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
71 expire = negative? negative_expire : positive_expire;
74 if (now - cache_record->time_stamp > expire)
76 HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type);
80 /* If this is a non-reject domain record, check for the obsolete format version
81 that doesn't have the postmaster and random timestamps, by looking at the
82 length. If so, copy it to a new-style block, replicating the record's
83 timestamp. Then check the additional timestamps. (There's no point wasting
84 effort if connections are rejected.) */
86 if (type[0] == 'd' && cache_record->result != ccache_reject)
88 if (length == sizeof(dbdata_callout_cache_obs))
90 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
91 memcpy(new, cache_record, length);
92 new->postmaster_stamp = new->random_stamp = new->time_stamp;
96 if (now - cache_record->postmaster_stamp > expire)
97 cache_record->postmaster_result = ccache_unknown;
99 if (now - cache_record->random_stamp > expire)
100 cache_record->random_result = ccache_unknown;
103 HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type);
109 /*************************************************
110 * Do callout verification for an address *
111 *************************************************/
113 /* This function is called from verify_address() when the address has routed to
114 a host list, and a callout has been requested. Callouts are expensive; that is
115 why a cache is used to improve the efficiency.
118 addr the address that's been routed
119 host_list the list of hosts to try
120 tf the transport feedback block
122 ifstring "interface" option from transport, or NULL
123 portstring "port" option from transport, or NULL
124 protocolstring "protocol" option from transport, or NULL
125 callout the per-command callout timeout
126 callout_overall the overall callout timeout (if < 0 use 4*callout)
127 callout_connect the callout connection timeout (if < 0 use callout)
128 options the verification options - these bits are used:
129 vopt_is_recipient => this is a recipient address
130 vopt_callout_no_cache => don't use callout cache
131 vopt_callout_random => do the "random" thing
132 vopt_callout_recipsender => use real sender for recipient
133 vopt_callout_recippmaster => use postmaster for recipient
134 se_mailfrom MAIL FROM address for sender verify; NULL => ""
135 pm_mailfrom if non-NULL, do the postmaster check with this sender
137 Returns: OK/FAIL/DEFER
141 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
142 int callout, int callout_overall, int callout_connect, int options,
143 uschar *se_mailfrom, uschar *pm_mailfrom)
145 BOOL is_recipient = (options & vopt_is_recipient) != 0;
146 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
147 BOOL callout_random = (options & vopt_callout_random) != 0;
152 uschar *from_address;
153 uschar *random_local_part = NULL;
154 uschar **failure_ptr = is_recipient?
155 &recipient_verify_failure : &sender_verify_failure;
157 open_db *dbm_file = NULL;
158 dbdata_callout_cache new_domain_record;
159 dbdata_callout_cache_address new_address_record;
161 time_t callout_start_time;
163 new_domain_record.result = ccache_unknown;
164 new_domain_record.postmaster_result = ccache_unknown;
165 new_domain_record.random_result = ccache_unknown;
167 memset(&new_address_record, 0, sizeof(new_address_record));
169 /* For a recipient callout, the key used for the address cache record must
170 include the sender address if we are using the real sender in the callout,
171 because that may influence the result of the callout. */
173 address_key = addr->address;
178 if ((options & vopt_callout_recipsender) != 0)
180 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
181 from_address = sender_address;
183 else if ((options & vopt_callout_recippmaster) != 0)
185 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
186 qualify_domain_sender);
187 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
191 /* For a sender callout, we must adjust the key if the mailfrom address is not
196 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
197 if (from_address[0] != 0)
198 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
201 /* Open the callout cache database, it it exists, for reading only at this
202 stage, unless caching has been disabled. */
204 if (callout_no_cache)
206 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
208 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
210 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
213 /* If a cache database is available see if we can avoid the need to do an
214 actual callout by making use of previously-obtained data. */
216 if (dbm_file != NULL)
218 dbdata_callout_cache_address *cache_address_record;
219 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
220 addr->domain, US"domain",
221 callout_cache_domain_positive_expire,
222 callout_cache_domain_negative_expire);
224 /* If an unexpired cache record was found for this domain, see if the callout
225 process can be short-circuited. */
227 if (cache_record != NULL)
229 /* If an early command (up to and including MAIL FROM:<>) was rejected,
230 there is no point carrying on. The callout fails. */
232 if (cache_record->result == ccache_reject)
234 setflag(addr, af_verify_nsfail);
236 debug_printf("callout cache: domain gave initial rejection, or "
237 "does not accept HELO or MAIL FROM:<>\n");
238 setflag(addr, af_verify_nsfail);
239 addr->user_message = US"(result of an earlier callout reused).";
241 *failure_ptr = US"mail";
245 /* If a previous check on a "random" local part was accepted, we assume
246 that the server does not do any checking on local parts. There is therefore
247 no point in doing the callout, because it will always be successful. If a
248 random check previously failed, arrange not to do it again, but preserve
249 the data in the new record. If a random check is required but hasn't been
250 done, skip the remaining cache processing. */
252 if (callout_random) switch(cache_record->random_result)
256 debug_printf("callout cache: domain accepts random addresses\n");
257 goto END_CALLOUT; /* Default yield is OK */
261 debug_printf("callout cache: domain rejects random addresses\n");
262 callout_random = FALSE;
263 new_domain_record.random_result = ccache_reject;
264 new_domain_record.random_stamp = cache_record->random_stamp;
269 debug_printf("callout cache: need to check random address handling "
270 "(not cached or cache expired)\n");
274 /* If a postmaster check is requested, but there was a previous failure,
275 there is again no point in carrying on. If a postmaster check is required,
276 but has not been done before, we are going to have to do a callout, so skip
277 remaining cache processing. */
279 if (pm_mailfrom != NULL)
281 if (cache_record->postmaster_result == ccache_reject)
283 setflag(addr, af_verify_pmfail);
285 debug_printf("callout cache: domain does not accept "
286 "RCPT TO:<postmaster@domain>\n");
288 *failure_ptr = US"postmaster";
289 setflag(addr, af_verify_pmfail);
290 addr->user_message = US"(result of earlier verification reused).";
293 if (cache_record->postmaster_result == ccache_unknown)
296 debug_printf("callout cache: need to check RCPT "
297 "TO:<postmaster@domain> (not cached or cache expired)\n");
301 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
302 postmaster check if the address itself has to be checked. Also ensure
303 that the value in the cache record is preserved (with its old timestamp).
306 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
307 "TO:<postmaster@domain>\n");
309 new_domain_record.postmaster_result = ccache_accept;
310 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
314 /* We can't give a result based on information about the domain. See if there
315 is an unexpired cache record for this specific address (combined with the
316 sender address if we are doing a recipient callout with a non-empty sender).
319 cache_address_record = (dbdata_callout_cache_address *)
320 get_callout_cache_record(dbm_file,
321 address_key, US"address",
322 callout_cache_positive_expire,
323 callout_cache_negative_expire);
325 if (cache_address_record != NULL)
327 if (cache_address_record->result == ccache_accept)
330 debug_printf("callout cache: address record is positive\n");
335 debug_printf("callout cache: address record is negative\n");
336 addr->user_message = US"Previous (cached) callout verification failure";
337 *failure_ptr = US"recipient";
343 /* Close the cache database while we actually do the callout for real. */
346 dbfn_close(dbm_file);
350 /* The information wasn't available in the cache, so we have to do a real
351 callout and save the result in the cache for next time, unless no_cache is set,
352 or unless we have a previously cached negative random result. If we are to test
353 with a random local part, ensure that such a local part is available. If not,
354 log the fact, but carry on without randomming. */
356 if (callout_random && callout_random_local_part != NULL)
358 random_local_part = expand_string(callout_random_local_part);
359 if (random_local_part == NULL)
360 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
361 "callout_random_local_part: %s", expand_string_message);
364 /* Default the connect and overall callout timeouts if not set, and record the
365 time we are starting so that we can enforce it. */
367 if (callout_overall < 0) callout_overall = 4 * callout;
368 if (callout_connect < 0) callout_connect = callout;
369 callout_start_time = time(NULL);
371 /* Now make connections to the hosts and do real callouts. The list of hosts
372 is passed in as an argument. */
374 for (host = host_list; host != NULL && !done; host = host->next)
376 smtp_inblock inblock;
377 smtp_outblock outblock;
380 BOOL send_quit = TRUE;
381 uschar *helo = US"HELO";
382 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
383 uschar inbuffer[4096];
384 uschar outbuffer[1024];
385 uschar responsebuffer[4096];
387 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
388 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
390 /* Skip this host if we don't have an IP address for it. */
392 if (host->address == NULL)
394 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
399 /* Check the overall callout timeout */
401 if (time(NULL) - callout_start_time >= callout_overall)
403 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
407 /* Set IPv4 or IPv6 */
409 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
411 /* Expand and interpret the interface and port strings. This has to
412 be delayed till now, because they may expand differently for different
413 hosts. If there's a failure, log it, but carry on with the defaults. */
415 deliver_host = host->name;
416 deliver_host_address = host->address;
417 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
419 !smtp_get_port(tf->port, addr, &port, US"callout"))
420 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
422 deliver_host = deliver_host_address = NULL;
424 /* Set HELO string according to the protocol */
426 if (Ustrcmp(tf->protocol, "lmtp") == 0) helo = US"LHLO";
428 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
430 /* Set up the buffer for reading SMTP response packets. */
432 inblock.buffer = inbuffer;
433 inblock.buffersize = sizeof(inbuffer);
434 inblock.ptr = inbuffer;
435 inblock.ptrend = inbuffer;
437 /* Set up the buffer for holding SMTP commands while pipelining */
439 outblock.buffer = outbuffer;
440 outblock.buffersize = sizeof(outbuffer);
441 outblock.ptr = outbuffer;
442 outblock.cmd_count = 0;
443 outblock.authenticating = FALSE;
445 /* Connect to the host; on failure, just loop for the next one, but we
446 set the error for the last one. Use the callout_connect timeout. */
448 inblock.sock = outblock.sock =
449 smtp_connect(host, host_af, port, interface, callout_connect, TRUE);
450 if (inblock.sock < 0)
452 addr->message = string_sprintf("could not connect to %s [%s]: %s",
453 host->name, host->address, strerror(errno));
457 /* Wait for initial response, and then run the initial SMTP commands. The
458 smtp_write_command() function leaves its command in big_buffer. This is
459 used in error responses. Initialize it in case the connection is
462 Ustrcpy(big_buffer, "initial connection");
465 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
468 smtp_write_command(&outblock, FALSE, "%s %s\r\n", helo,
469 smtp_active_hostname) >= 0 &&
470 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
473 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
474 from_address) >= 0 &&
475 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
478 /* If the host gave an initial error, or does not accept HELO or MAIL
479 FROM:<>, arrange to cache this information, but don't record anything for an
480 I/O error or a defer. Do not cache rejections when a non-empty sender has
481 been used, because that blocks the whole domain for all senders. */
485 *failure_ptr = US"mail";
486 if (errno == 0 && responsebuffer[0] == '5')
488 setflag(addr, af_verify_nsfail);
489 if (from_address[0] == 0) new_domain_record.result = ccache_reject;
493 /* Otherwise, proceed to check a "random" address (if required), then the
494 given address, and the postmaster address (if required). Between each check,
495 issue RSET, because some servers accept only one recipient after MAIL
500 new_domain_record.result = ccache_accept;
502 /* Do the random local part check first */
504 if (random_local_part != NULL)
506 uschar randombuffer[1024];
508 smtp_write_command(&outblock, FALSE,
509 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
510 addr->domain) >= 0 &&
511 smtp_read_response(&inblock, randombuffer,
512 sizeof(randombuffer), '2', callout);
514 /* Remember when we last did a random test */
516 new_domain_record.random_stamp = time(NULL);
518 /* If accepted, we aren't going to do any further tests below. */
522 new_domain_record.random_result = ccache_accept;
525 /* Otherwise, cache a real negative response, and get back to the right
526 state to send RCPT. Unless there's some problem such as a dropped
527 connection, we expect to succeed, because the commands succeeded above. */
531 if (randombuffer[0] == '5')
532 new_domain_record.random_result = ccache_reject;
535 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
536 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
539 smtp_write_command(&outblock, FALSE, "MAIL FROM:<>\r\n") >= 0 &&
540 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
543 else done = FALSE; /* Some timeout/connection problem */
546 /* If the host is accepting all local parts, as determined by the "random"
547 check, we don't need to waste time doing any further checking. */
549 if (new_domain_record.random_result != ccache_accept && done)
552 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
553 transport_rcpt_address(addr,
554 addr->transport->rcpt_include_affixes)) >= 0 &&
555 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
559 new_address_record.result = ccache_accept;
560 else if (errno == 0 && responsebuffer[0] == '5')
562 *failure_ptr = US"recipient";
563 new_address_record.result = ccache_reject;
566 /* Do postmaster check if requested */
568 if (done && pm_mailfrom != NULL)
571 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
572 smtp_read_response(&inblock, responsebuffer,
573 sizeof(responsebuffer), '2', callout) &&
575 smtp_write_command(&outblock, FALSE,
576 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
577 smtp_read_response(&inblock, responsebuffer,
578 sizeof(responsebuffer), '2', callout) &&
580 smtp_write_command(&outblock, FALSE,
581 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
582 smtp_read_response(&inblock, responsebuffer,
583 sizeof(responsebuffer), '2', callout);
585 new_domain_record.postmaster_stamp = time(NULL);
588 new_domain_record.postmaster_result = ccache_accept;
589 else if (errno == 0 && responsebuffer[0] == '5')
591 *failure_ptr = US"postmaster";
592 setflag(addr, af_verify_pmfail);
593 new_domain_record.postmaster_result = ccache_reject;
596 } /* Random not accepted */
597 } /* MAIL FROM:<> accepted */
599 /* For any failure of the main check, other than a negative response, we just
600 close the connection and carry on. We can identify a negative response by the
601 fact that errno is zero. For I/O errors it will be non-zero
603 Set up different error texts for logging and for sending back to the caller
604 as an SMTP response. Log in all cases, using a one-line format. For sender
605 callouts, give a full response to the caller, but for recipient callouts,
606 don't give the IP address because this may be an internal host whose identity
607 is not to be widely broadcast. */
611 if (errno == ETIMEDOUT)
613 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
618 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
621 string_sprintf("response to \"%s\" from %s [%s] was: %s",
622 big_buffer, host->name, host->address,
623 string_printing(responsebuffer));
625 addr->user_message = is_recipient?
626 string_sprintf("Callout verification failed:\n%s", responsebuffer)
628 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
629 host->address, big_buffer, responsebuffer);
631 /* Hard rejection ends the process */
633 if (responsebuffer[0] == '5') /* Address rejected */
641 /* End the SMTP conversation and close the connection. */
643 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
645 } /* Loop through all hosts, while !done */
647 /* If we get here with done == TRUE, a successful callout happened, and yield
648 will be set OK or FAIL according to the response to the RCPT command.
649 Otherwise, we looped through the hosts but couldn't complete the business.
650 However, there may be domain-specific information to cache in both cases.
652 The value of the result field in the new_domain record is ccache_unknown if
653 there was an error before or with MAIL FROM:<>, and errno was not zero,
654 implying some kind of I/O error. We don't want to write the cache in that case.
655 Otherwise the value is ccache_accept or ccache_reject. */
657 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
659 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
662 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
666 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
667 (int)sizeof(dbdata_callout_cache));
668 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
669 " result=%d postmaster=%d random=%d\n",
670 new_domain_record.result,
671 new_domain_record.postmaster_result,
672 new_domain_record.random_result);
676 /* If a definite result was obtained for the callout, cache it unless caching
681 if (!callout_no_cache && new_address_record.result != ccache_unknown)
683 if (dbm_file == NULL)
684 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
685 if (dbm_file == NULL)
687 HDEBUG(D_verify) debug_printf("no callout cache available\n");
691 (void)dbfn_write(dbm_file, address_key, &new_address_record,
692 (int)sizeof(dbdata_callout_cache_address));
693 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
694 (new_address_record.result == ccache_accept)? "positive" : "negative");
699 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
700 temporary error. If there was only one host, and a response was received, leave
701 it alone if supplying details. Otherwise, give a generic response. */
705 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
706 is_recipient? "recipient" : "sender");
709 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
711 addr->user_message = (!smtp_return_error_details)? dullmsg :
712 string_sprintf("%s for <%s>.\n"
713 "The mail server(s) for the domain may be temporarily unreachable, or\n"
714 "they may be permanently unreachable from this server. In the latter case,\n%s",
715 dullmsg, addr->address,
717 "the address will never be accepted."
719 "you need to change the address or create an MX record for its domain\n"
720 "if it is supposed to be generally accessible from the Internet.\n"
721 "Talk to your mail administrator for details.");
723 /* Force a specific error code */
725 addr->basic_errno = ERRNO_CALLOUTDEFER;
728 /* Come here from within the cache-reading code on fast-track exit. */
731 if (dbm_file != NULL) dbfn_close(dbm_file);
737 /*************************************************
738 * Copy error to toplevel address *
739 *************************************************/
741 /* This function is used when a verify fails or defers, to ensure that the
742 failure or defer information is in the original toplevel address. This applies
743 when an address is redirected to a single new address, and the failure or
744 deferral happens to the child address.
747 vaddr the verify address item
748 addr the final address item
751 Returns: the value of YIELD
755 copy_error(address_item *vaddr, address_item *addr, int yield)
759 vaddr->message = addr->message;
760 vaddr->user_message = addr->user_message;
761 vaddr->basic_errno = addr->basic_errno;
762 vaddr->more_errno = addr->more_errno;
770 /*************************************************
771 * Verify an email address *
772 *************************************************/
774 /* This function is used both for verification (-bv and at other times) and
775 address testing (-bt), which is indicated by address_test_mode being set.
778 vaddr contains the address to verify; the next field in this block
780 f if not NULL, write the result to this file
781 options various option bits:
782 vopt_fake_sender => this sender verify is not for the real
783 sender (it was verify=sender=xxxx or an address from a
784 header line) - rewriting must not change sender_address
785 vopt_is_recipient => this is a recipient address, otherwise
786 it's a sender address - this affects qualification and
787 rewriting and messages from callouts
788 vopt_qualify => qualify an unqualified address; else error
789 vopt_expn => called from SMTP EXPN command
791 These ones are used by do_callout() -- the options variable
794 vopt_callout_no_cache => don't use callout cache
795 vopt_callout_random => do the "random" thing
796 vopt_callout_recipsender => use real sender for recipient
797 vopt_callout_recippmaster => use postmaster for recipient
799 callout if > 0, specifies that callout is required, and gives timeout
800 for individual commands
801 callout_overall if > 0, gives overall timeout for the callout function;
802 if < 0, a default is used (see do_callout())
803 callout_connect the connection timeout for callouts
804 se_mailfrom when callout is requested to verify a sender, use this
805 in MAIL FROM; NULL => ""
806 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
807 thing and use this as the sender address (may be "")
809 routed if not NULL, set TRUE if routing succeeded, so we can
810 distinguish between routing failed and callout failed
812 Returns: OK address verified
813 FAIL address failed to verify
814 DEFER can't tell at present
818 verify_address(address_item *vaddr, FILE *f, int options, int callout,
819 int callout_overall, int callout_connect, uschar *se_mailfrom,
820 uschar *pm_mailfrom, BOOL *routed)
823 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
824 BOOL is_recipient = (options & vopt_is_recipient) != 0;
825 BOOL expn = (options & vopt_expn) != 0;
828 int verify_type = expn? v_expn :
829 address_test_mode? v_none :
830 is_recipient? v_recipient : v_sender;
831 address_item *addr_list;
832 address_item *addr_new = NULL;
833 address_item *addr_remote = NULL;
834 address_item *addr_local = NULL;
835 address_item *addr_succeed = NULL;
836 uschar **failure_ptr = is_recipient?
837 &recipient_verify_failure : &sender_verify_failure;
838 uschar *ko_prefix, *cr;
839 uschar *address = vaddr->address;
841 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
843 /* Clear, just in case */
847 /* Set up a prefix and suffix for error message which allow us to use the same
848 output statements both in EXPN mode (where an SMTP response is needed) and when
849 debugging with an output file. */
853 ko_prefix = US"553 ";
856 else ko_prefix = cr = US"";
858 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
860 if (parse_find_at(address) == NULL)
862 if ((options & vopt_qualify) == 0)
865 fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address,
867 *failure_ptr = US"qualify";
870 address = rewrite_address_qualify(address, is_recipient);
875 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
876 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
879 /* Rewrite and report on it. Clear the domain and local part caches - these
880 may have been set by domains and local part tests during an ACL. */
882 if (global_rewrite_rules != NULL)
884 uschar *old = address;
885 address = rewrite_address(address, is_recipient, FALSE,
886 global_rewrite_rules, rewrite_existflags);
889 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
890 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
891 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
895 /* If this is the real sender address, we must update sender_address at
896 this point, because it may be referred to in the routers. */
898 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
899 sender_address = address;
901 /* If the address was rewritten to <> no verification can be done, and we have
902 to return OK. This rewriting is permitted only for sender addresses; for other
903 addresses, such rewriting fails. */
905 if (address[0] == 0) return OK;
907 /* Save a copy of the sender address for re-instating if we change it to <>
908 while verifying a sender address (a nice bit of self-reference there). */
910 save_sender = sender_address;
912 /* Update the address structure with the possibly qualified and rewritten
913 address. Set it up as the starting address on the chain of new addresses. */
915 vaddr->address = address;
918 /* We need a loop, because an address can generate new addresses. We must also
919 cope with generated pipes and files at the top level. (See also the code and
920 comment in deliver.c.) However, it is usually the case that the router for
921 user's .forward files has its verify flag turned off.
923 If an address generates more than one child, the loop is used only when
924 full_info is set, and this can only be set locally. Remote enquiries just get
925 information about the top level address, not anything that it generated. */
927 while (addr_new != NULL)
930 address_item *addr = addr_new;
932 addr_new = addr->next;
937 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
938 debug_printf("Considering %s\n", addr->address);
941 /* Handle generated pipe, file or reply addresses. We don't get these
942 when handling EXPN, as it does only one level of expansion. */
944 if (testflag(addr, af_pfr))
951 if (addr->address[0] == '>')
953 allow = testflag(addr, af_allow_reply);
954 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
958 allow = (addr->address[0] == '|')?
959 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
960 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
963 if (addr->basic_errno == ERRNO_BADTRANSPORT)
964 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
965 "%s\n", addr->message);
967 fprintf(f, "\n transport = %s\n", addr->transport->name);
969 fprintf(f, " *** forbidden ***\n");
974 /* Just in case some router parameter refers to it. */
976 return_path = (addr->p.errors_address != NULL)?
977 addr->p.errors_address : sender_address;
979 /* Split the address into domain and local part, handling the %-hack if
980 necessary, and then route it. While routing a sender address, set
981 $sender_address to <> because that is what it will be if we were trying to
982 send a bounce to the sender. */
984 if (routed != NULL) *routed = FALSE;
985 if ((rc = deliver_split_address(addr)) == OK)
987 if (!is_recipient) sender_address = null_sender;
988 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
989 &addr_succeed, verify_type);
990 sender_address = save_sender; /* Put back the real sender */
993 /* If routing an address succeeded, set the flag that remembers, for use when
994 an ACL cached a sender verify (in case a callout fails). Then if routing set
995 up a list of hosts or the transport has a host list, and the callout option
996 is set, and we aren't in a host checking run, do the callout verification,
997 and set another flag that notes that a callout happened. */
1001 if (routed != NULL) *routed = TRUE;
1004 host_item *host_list = addr->host_list;
1006 /* Default, if no remote transport, to NULL for the interface (=> any),
1007 "smtp" for the port, and "smtp" for the protocol. */
1009 transport_feedback tf = { NULL, US"smtp", US"smtp", NULL, FALSE, FALSE };
1011 /* If verification yielded a remote transport, we want to use that
1012 transport's options, so as to mimic what would happen if we were really
1013 sending a message to this address. */
1015 if (addr->transport != NULL && !addr->transport->info->local)
1017 (void)(addr->transport->setup)(addr->transport, addr, &tf, NULL);
1019 /* If the transport has hosts and the router does not, or if the
1020 transport is configured to override the router's hosts, we must build a
1021 host list of the transport's hosts, and find the IP addresses */
1023 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1027 host_list = NULL; /* Ignore the router's hosts */
1029 deliver_domain = addr->domain;
1030 deliver_localpart = addr->local_part;
1031 s = expand_string(tf.hosts);
1032 deliver_domain = deliver_localpart = NULL;
1036 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1037 "\"%s\" in %s transport for callout: %s", tf.hosts,
1038 addr->transport->name, expand_string_message);
1042 uschar *canonical_name;
1043 host_item *host, *nexthost;
1044 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1046 /* Just ignore failures to find a host address. If we don't manage
1047 to find any addresses, the callout will defer. Note that more than
1048 one address may be found for a single host, which will result in
1049 additional host items being inserted into the chain. Hence we must
1050 save the next host first. */
1052 for (host = host_list; host != NULL; host = nexthost)
1054 nexthost = host->next;
1055 if (tf.gethostbyname ||
1056 string_is_ip_address(host->name, NULL) > 0)
1057 (void)host_find_byname(host, NULL, &canonical_name, TRUE);
1060 int flags = HOST_FIND_BY_A;
1061 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1062 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1063 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1064 &canonical_name, NULL);
1071 /* Can only do a callout if we have at least one host! If the callout
1072 fails, it will have set ${sender,recipient}_verify_failure. */
1074 if (host_list != NULL)
1076 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1077 if (host_checking && !host_checking_callout)
1080 debug_printf("... callout omitted by default when host testing\n"
1081 "(Use -bhc if you want the callouts to happen.)\n");
1085 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1086 callout_connect, options, se_mailfrom, pm_mailfrom);
1091 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1092 "transport provided a host list\n");
1097 /* Otherwise, any failure is a routing failure */
1099 else *failure_ptr = US"route";
1101 /* A router may return REROUTED if it has set up a child address as a result
1102 of a change of domain name (typically from widening). In this case we always
1103 want to continue to verify the new child. */
1105 if (rc == REROUTED) continue;
1107 /* Handle hard failures */
1114 fprintf(f, "%s%s %s", ko_prefix, address,
1115 address_test_mode? "is undeliverable" : "failed to verify");
1116 if (!expn && admin_user)
1118 if (addr->basic_errno > 0)
1119 fprintf(f, ": %s", strerror(addr->basic_errno));
1120 if (addr->message != NULL)
1121 fprintf(f, ":\n %s", addr->message);
1123 fprintf(f, "%s\n", cr);
1126 if (!full_info) return copy_error(vaddr, addr, FAIL);
1132 else if (rc == DEFER)
1137 fprintf(f, "%s%s cannot be resolved at this time", ko_prefix, address);
1138 if (!expn && admin_user)
1140 if (addr->basic_errno > 0)
1141 fprintf(f, ":\n %s", strerror(addr->basic_errno));
1142 if (addr->message != NULL)
1143 fprintf(f, ":\n %s", addr->message);
1144 else if (addr->basic_errno <= 0)
1145 fprintf(f, ":\n unknown error");
1148 fprintf(f, "%s\n", cr);
1150 if (!full_info) return copy_error(vaddr, addr, DEFER);
1151 else if (yield == OK) yield = DEFER;
1154 /* If we are handling EXPN, we do not want to continue to route beyond
1159 uschar *ok_prefix = US"250-";
1160 if (addr_new == NULL)
1162 if (addr_local == NULL && addr_remote == NULL)
1163 fprintf(f, "250 mail to <%s> is discarded\r\n", address);
1165 fprintf(f, "250 <%s>\r\n", address);
1167 else while (addr_new != NULL)
1169 address_item *addr2 = addr_new;
1170 addr_new = addr2->next;
1171 if (addr_new == NULL) ok_prefix = US"250 ";
1172 fprintf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1177 /* Successful routing other than EXPN. */
1181 /* Handle successful routing when short info wanted. Otherwise continue for
1182 other (generated) addresses. Short info is the operational case. Full info
1183 can be requested only when debug_selector != 0 and a file is supplied.
1185 There is a conflict between the use of aliasing as an alternate email
1186 address, and as a sort of mailing list. If an alias turns the incoming
1187 address into just one address (e.g. J.Caesar->jc44) you may well want to
1188 carry on verifying the generated address to ensure it is valid when
1189 checking incoming mail. If aliasing generates multiple addresses, you
1190 probably don't want to do this. Exim therefore treats the generation of
1191 just a single new address as a special case, and continues on to verify the
1192 generated address. */
1194 if (!full_info && /* Stop if short info wanted AND */
1195 (addr_new == NULL || /* No new address OR */
1196 addr_new->next != NULL || /* More than one new address OR */
1197 testflag(addr_new, af_pfr))) /* New address is pfr */
1199 if (f != NULL) fprintf(f, "%s %s\n", address,
1200 address_test_mode? "is deliverable" : "verified");
1202 /* If we have carried on to verify a child address, we want the value
1203 of $address_data to be that of the child */
1205 vaddr->p.address_data = addr->p.address_data;
1209 } /* Loop for generated addresses */
1211 /* Display the full results of the successful routing, including any generated
1212 addresses. Control gets here only when full_info is set, which requires f not
1213 to be NULL, and this occurs only when a top-level verify is called with the
1214 debugging switch on.
1216 If there are no local and no remote addresses, and there were no pipes, files,
1217 or autoreplies, and there were no errors or deferments, the message is to be
1218 discarded, usually because of the use of :blackhole: in an alias file. */
1220 if (allok && addr_local == NULL && addr_remote == NULL)
1221 fprintf(f, "mail to %s is discarded\n", address);
1223 else for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1225 while (addr_list != NULL)
1227 address_item *addr = addr_list;
1228 address_item *p = addr->parent;
1229 addr_list = addr->next;
1231 fprintf(f, "%s", CS addr->address);
1234 fprintf(f, "\n <-- %s", p->address);
1239 /* Show router, and transport */
1241 fprintf(f, "router = %s, ", addr->router->name);
1242 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1243 addr->transport->name);
1245 /* Show any hosts that are set up by a router unless the transport
1246 is going to override them; fiddle a bit to get a nice format. */
1248 if (addr->host_list != NULL && addr->transport != NULL &&
1249 !addr->transport->overrides_hosts)
1254 for (h = addr->host_list; h != NULL; h = h->next)
1256 int len = Ustrlen(h->name);
1257 if (len > maxlen) maxlen = len;
1258 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1259 if (len > maxaddlen) maxaddlen = len;
1261 for (h = addr->host_list; h != NULL; h = h->next)
1263 int len = Ustrlen(h->name);
1264 fprintf(f, " host %s ", h->name);
1265 while (len++ < maxlen) fprintf(f, " ");
1266 if (h->address != NULL)
1268 fprintf(f, "[%s] ", h->address);
1269 len = Ustrlen(h->address);
1271 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1273 fprintf(f, "[unknown] ");
1277 while (len++ < maxaddlen) fprintf(f," ");
1278 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1279 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1280 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1287 /* Will be DEFER or FAIL if any one address has, only for full_info (which is
1288 the -bv or -bt case). */
1296 /*************************************************
1297 * Check headers for syntax errors *
1298 *************************************************/
1300 /* This function checks those header lines that contain addresses, and verifies
1301 that all the addresses therein are syntactially correct.
1304 msgptr where to put an error message
1311 verify_check_headers(uschar **msgptr)
1316 for (h = header_list; h != NULL; h = h->next)
1318 if (h->type != htype_from &&
1319 h->type != htype_reply_to &&
1320 h->type != htype_sender &&
1321 h->type != htype_to &&
1322 h->type != htype_cc &&
1323 h->type != htype_bcc)
1326 colon = Ustrchr(h->text, ':');
1328 while (isspace(*s)) s++;
1330 parse_allow_group = TRUE; /* Allow group syntax */
1332 /* Loop for multiple addresses in the header */
1336 uschar *ss = parse_find_address_end(s, FALSE);
1337 uschar *recipient, *errmess;
1338 int terminator = *ss;
1339 int start, end, domain;
1341 /* Temporarily terminate the string at this point, and extract the
1342 operative address within. */
1345 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
1348 /* Permit an unqualified address only if the message is local, or if the
1349 sending host is configured to be permitted to send them. */
1351 if (recipient != NULL && domain == 0)
1353 if (h->type == htype_from || h->type == htype_sender)
1355 if (!allow_unqualified_sender) recipient = NULL;
1359 if (!allow_unqualified_recipient) recipient = NULL;
1361 if (recipient == NULL) errmess = US"unqualified address not permitted";
1364 /* It's an error if no address could be extracted, except for the special
1365 case of an empty address. */
1367 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
1369 uschar *verb = US"is";
1373 /* Arrange not to include any white space at the end in the
1376 while (t > s && isspace(t[-1])) t--;
1378 /* Add the address which failed to the error message, since in a
1379 header with very many addresses it is sometimes hard to spot
1380 which one is at fault. However, limit the amount of address to
1381 quote - cases have been seen where, for example, a missing double
1382 quote in a humungous To: header creates an "address" that is longer
1383 than string_sprintf can handle. */
1392 *msgptr = string_printing(
1393 string_sprintf("%s: failing address in \"%.*s\" header %s: %.*s",
1394 errmess, colon - h->text, h->text, verb, len, s));
1399 /* Advance to the next address */
1401 s = ss + (terminator? 1:0);
1402 while (isspace(*s)) s++;
1403 } /* Next address */
1412 /*************************************************
1413 * Find if verified sender *
1414 *************************************************/
1416 /* Usually, just a single address is verified as the sender of the message.
1417 However, Exim can be made to verify other addresses as well (often related in
1418 some way), and this is useful in some environments. There may therefore be a
1419 chain of such addresses that have previously been tested. This function finds
1420 whether a given address is on the chain.
1422 Arguments: the address to be verified
1423 Returns: pointer to an address item, or NULL
1427 verify_checked_sender(uschar *sender)
1430 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
1431 if (Ustrcmp(sender, addr->address) == 0) break;
1439 /*************************************************
1440 * Get valid header address *
1441 *************************************************/
1443 /* Scan the originator headers of the message, looking for an address that
1444 verifies successfully. RFC 822 says:
1446 o The "Sender" field mailbox should be sent notices of
1447 any problems in transport or delivery of the original
1448 messages. If there is no "Sender" field, then the
1449 "From" field mailbox should be used.
1451 o If the "Reply-To" field exists, then the reply should
1452 go to the addresses indicated in that field and not to
1453 the address(es) indicated in the "From" field.
1455 So we check a Sender field if there is one, else a Reply_to field, else a From
1456 field. As some strange messages may have more than one of these fields,
1457 especially if they are resent- fields, check all of them if there is more than
1461 user_msgptr points to where to put a user error message
1462 log_msgptr points to where to put a log error message
1463 callout timeout for callout check (passed to verify_address())
1464 callout_overall overall callout timeout (ditto)
1465 callout_connect connect callout timeout (ditto)
1466 se_mailfrom mailfrom for verify; NULL => ""
1467 pm_mailfrom sender for pm callout check (passed to verify_address())
1468 options callout options (passed to verify_address())
1469 verrno where to put the address basic_errno
1471 If log_msgptr is set to something without setting user_msgptr, the caller
1472 normally uses log_msgptr for both things.
1474 Returns: result of the verification attempt: OK, FAIL, or DEFER;
1475 FAIL is given if no appropriate headers are found
1479 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
1480 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
1481 uschar *pm_mailfrom, int options, int *verrno)
1483 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
1487 for (i = 0; i < 3; i++)
1490 for (h = header_list; h != NULL; h = h->next)
1492 int terminator, new_ok;
1493 uschar *s, *ss, *endname;
1495 if (h->type != header_types[i]) continue;
1496 s = endname = Ustrchr(h->text, ':') + 1;
1500 address_item *vaddr;
1502 while (isspace(*s) || *s == ',') s++;
1503 if (*s == 0) break; /* End of header */
1505 ss = parse_find_address_end(s, FALSE);
1507 /* The terminator is a comma or end of header, but there may be white
1508 space preceding it (including newline for the last address). Move back
1509 past any white space so we can check against any cached envelope sender
1510 address verifications. */
1512 while (isspace(ss[-1])) ss--;
1516 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
1517 (int)(endname - h->text), h->text, s);
1519 /* See if we have already verified this address as an envelope sender,
1520 and if so, use the previous answer. */
1522 vaddr = verify_checked_sender(s);
1524 if (vaddr != NULL && /* Previously checked */
1525 (callout <= 0 || /* No callout needed; OR */
1526 vaddr->special_action > 256)) /* Callout was done */
1528 new_ok = vaddr->special_action & 255;
1529 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
1530 *ss = terminator; /* Restore shortened string */
1533 /* Otherwise we run the verification now. We must restore the shortened
1534 string before running the verification, so the headers are correct, in
1535 case there is any rewriting. */
1539 int start, end, domain;
1540 uschar *address = parse_extract_address(s, log_msgptr, &start,
1541 &end, &domain, FALSE);
1545 /* If verification failed because of a syntax error, fail this
1546 function, and ensure that the failing address gets added to the error
1549 if (address == NULL)
1552 if (*log_msgptr != NULL)
1554 while (ss > s && isspace(ss[-1])) ss--;
1555 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
1556 "scanning for sender: %s in \"%.*s\"",
1557 endname - h->text, h->text, *log_msgptr, ss - s, s);
1562 /* Else go ahead with the sender verification. But it isn't *the*
1563 sender of the message, so set vopt_fake_sender to stop sender_address
1564 being replaced after rewriting or qualification. */
1568 vaddr = deliver_make_addr(address, FALSE);
1569 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
1570 callout, callout_overall, callout_connect, se_mailfrom,
1575 /* We now have the result, either newly found, or cached. If we are
1576 giving out error details, set a specific user error. This means that the
1577 last of these will be returned to the user if all three fail. We do not
1578 set a log message - the generic one below will be used. */
1582 *verrno = vaddr->basic_errno;
1583 if (smtp_return_error_details)
1585 *user_msgptr = string_sprintf("Rejected after DATA: "
1586 "could not verify \"%.*s\" header address\n%s: %s",
1587 endname - h->text, h->text, vaddr->address, vaddr->message);
1591 /* Success or defer */
1593 if (new_ok == OK) return OK;
1594 if (new_ok == DEFER) yield = DEFER;
1596 /* Move on to any more addresses in the header */
1603 if (yield == FAIL && *log_msgptr == NULL)
1604 *log_msgptr = US"there is no valid sender in any header line";
1606 if (yield == DEFER && *log_msgptr == NULL)
1607 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
1615 /*************************************************
1616 * Get RFC 1413 identification *
1617 *************************************************/
1619 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
1620 the timeout is set to zero, then the query is not done. There may also be lists
1621 of hosts and nets which are exempt. To guard against malefactors sending
1622 non-printing characters which could, for example, disrupt a message's headers,
1623 make sure the string consists of printing characters only.
1626 port the port to connect to; usually this is IDENT_PORT (113), but when
1627 running in the test harness with -bh a different value is used.
1631 Side effect: any received ident value is put in sender_ident (NULL otherwise)
1635 verify_get_ident(int port)
1637 int sock, host_af, qlen;
1638 int received_sender_port, received_interface_port, n;
1640 uschar buffer[2048];
1642 /* Default is no ident. Check whether we want to do an ident check for this
1645 sender_ident = NULL;
1646 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
1649 DEBUG(D_ident) debug_printf("doing ident callback\n");
1651 /* Set up a connection to the ident port of the remote host. Bind the local end
1652 to the incoming interface address. If the sender host address is an IPv6
1653 address, the incoming interface address will also be IPv6. */
1655 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
1656 sock = ip_socket(SOCK_STREAM, host_af);
1657 if (sock < 0) return;
1659 if (ip_bind(sock, host_af, interface_address, 0) < 0)
1661 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
1666 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
1669 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
1671 log_write(0, LOG_MAIN, "ident connection to %s timed out",
1672 sender_host_address);
1676 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
1677 sender_host_address, strerror(errno));
1682 /* Construct and send the query. */
1684 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
1685 qlen = Ustrlen(buffer);
1686 if (send(sock, buffer, qlen, 0) < 0)
1688 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
1692 /* Read a response line. We put it into the rest of the buffer, using several
1693 recv() calls if necessary. */
1701 int size = sizeof(buffer) - (p - buffer);
1703 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
1704 count = ip_recv(sock, p, size, rfc1413_query_timeout);
1705 if (count <= 0) goto END_OFF; /* Read error or EOF */
1707 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
1708 generous, and accept a plain \n terminator as well. The only illegal
1711 for (pp = p; pp < p + count; pp++)
1713 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
1716 if (pp[-1] == '\r') pp--;
1718 goto GOT_DATA; /* Break out of both loops */
1722 /* Reached the end of the data without finding \n. Let the loop continue to
1723 read some more, if there is room. */
1730 /* We have received a line of data. Check it carefully. It must start with the
1731 same two port numbers that we sent, followed by data as defined by the RFC. For
1734 12345 , 25 : USERID : UNIX :root
1736 However, the amount of white space may be different to what we sent. In the
1737 "osname" field there may be several sub-fields, comma separated. The data we
1738 actually want to save follows the third colon. Some systems put leading spaces
1739 in it - we discard those. */
1741 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
1742 &received_interface_port, &n) != 2 ||
1743 received_sender_port != sender_host_port ||
1744 received_interface_port != interface_port)
1747 p = buffer + qlen + n;
1748 while(isspace(*p)) p++;
1749 if (*p++ != ':') goto END_OFF;
1750 while(isspace(*p)) p++;
1751 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
1753 while(isspace(*p)) p++;
1754 if (*p++ != ':') goto END_OFF;
1755 while (*p != 0 && *p != ':') p++;
1756 if (*p++ == 0) goto END_OFF;
1757 while(isspace(*p)) p++;
1758 if (*p == 0) goto END_OFF;
1760 /* The rest of the line is the data we want. We turn it into printing
1761 characters when we save it, so that it cannot mess up the format of any logging
1762 or Received: lines into which it gets inserted. We keep a maximum of 127
1765 sender_ident = string_printing(string_copyn(p, 127));
1766 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
1776 /*************************************************
1777 * Match host to a single host-list item *
1778 *************************************************/
1780 /* This function compares a host (name or address) against a single item
1781 from a host list. The host name gets looked up if it is needed and is not
1782 already known. The function is called from verify_check_this_host() via
1783 match_check_list(), which is why most of its arguments are in a single block.
1786 arg the argument block (see below)
1787 ss the host-list item
1788 valueptr where to pass back looked up data, or NULL
1789 error for error message when returning ERROR
1792 host_name the host name or NULL, implying use sender_host_name and
1793 sender_host_aliases, looking them up if required
1794 host_address the host address
1795 host_ipv4 the IPv4 address taken from an IPv6 one
1799 DEFER lookup deferred
1800 ERROR failed to find the host name or IP address
1801 unknown lookup type specified
1805 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
1807 check_host_block *cb = (check_host_block *)arg;
1809 BOOL isquery = FALSE;
1810 uschar *semicolon, *t;
1813 /* Optimize for the special case when the pattern is "*". */
1815 if (*ss == '*' && ss[1] == 0) return OK;
1817 /* If the pattern is empty, it matches only in the case when there is no host -
1818 this can occur in ACL checking for SMTP input using the -bs option. In this
1819 situation, the host address is the empty string. */
1821 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
1822 if (*ss == 0) return FAIL;
1824 /* If the pattern is precisely "@" then match against the primary host name;
1825 if it's "@[]" match against the local host's IP addresses. */
1829 if (ss[1] == 0) ss = primary_hostname;
1830 else if (Ustrcmp(ss, "@[]") == 0)
1832 ip_address_item *ip;
1833 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
1834 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
1839 /* If the pattern is an IP address, optionally followed by a bitmask count, do
1840 a (possibly masked) comparision with the current IP address. */
1842 if (string_is_ip_address(ss, &maskoffset) > 0)
1843 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
1845 /* If the item is of the form net[n]-lookup;<file|query> then it is a lookup on
1846 a masked IP network, in textual form. The net- stuff really only applies to
1847 single-key lookups where the key is implicit. For query-style lookups the key
1848 is specified in the query. From release 4.30, the use of net- for query style
1849 is no longer needed, but we retain it for backward compatibility. */
1851 if (Ustrncmp(ss, "net", 3) == 0 && (semicolon = Ustrchr(ss, ';')) != NULL)
1854 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
1861 uschar *filename, *key, *result;
1864 /* If no mask was supplied, set a negative value */
1866 if (mlen == 0 && t == ss+4) mlen = -1;
1868 /* Find the search type */
1870 search_type = search_findtype(t, semicolon - t);
1872 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1873 search_error_message);
1875 /* Adjust parameters for the type of lookup. For a query-style
1876 lookup, there is no file name, and the "key" is just the query. For
1877 a single-key lookup, the key is the current IP address, masked
1878 appropriately, and reconverted to text form, with the mask appended.
1879 For IPv6 addresses, specify dot separators instead of colons. */
1881 if (mac_islookup(search_type, lookup_querystyle))
1884 key = semicolon + 1;
1888 insize = host_aton(cb->host_address, incoming);
1889 host_mask(insize, incoming, mlen);
1890 (void)host_nmtoa(insize, incoming, mlen, buffer, '.');
1892 filename = semicolon + 1;
1895 /* Now do the actual lookup; note that there is no search_close() because
1896 of the caching arrangements. */
1898 handle = search_open(filename, search_type, 0, NULL, NULL);
1899 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1900 search_error_message);
1901 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
1902 if (valueptr != NULL) *valueptr = result;
1903 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
1907 /* The pattern is not an IP address or network reference of any kind. That is,
1908 it is a host name pattern. Check the characters of the pattern to see if they
1909 comprise only letters, digits, full stops, and hyphens (the constituents of
1910 domain names). Allow underscores, as they are all too commonly found. Sigh.
1911 Also, if allow_utf8_domains is set, allow top-bit characters. */
1913 for (t = ss; *t != 0; t++)
1914 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
1915 (!allow_utf8_domains || *t < 128)) break;
1917 /* If the pattern is a complete domain name, with no fancy characters, look up
1918 its IP address and match against that. Note that a multi-homed host will add
1919 items to the chain. */
1929 rc = host_find_byname(&h, NULL, NULL, FALSE);
1930 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1933 for (hh = &h; hh != NULL; hh = hh->next)
1935 if (Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)?
1936 cb->host_ipv4 : cb->host_address) == 0)
1941 if (rc == HOST_FIND_AGAIN) return DEFER;
1942 *error = string_sprintf("failed to find IP address for %s", ss);
1946 /* Almost all subsequent comparisons require the host name, and can be done
1947 using the general string matching function. When this function is called for
1948 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
1949 must use sender_host_name and its aliases, looking them up if necessary. */
1951 if (cb->host_name != NULL) /* Explicit host name given */
1952 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
1955 /* Host name not given; in principle we need the sender host name and its
1956 aliases. However, for query-style lookups, we do not need the name if the
1957 query does not contain $sender_host_name. From release 4.23, a reference to
1958 $sender_host_name causes it to be looked up, so we don't need to do the lookup
1961 if ((semicolon = Ustrchr(ss, ';')) != NULL)
1964 int partial, affixlen, starflags, id;
1967 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
1970 if (id < 0) /* Unknown lookup type */
1972 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
1973 search_error_message, ss);
1976 isquery = mac_islookup(id, lookup_querystyle);
1981 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
1984 case DEFER: return DEFER;
1985 default: return FAIL;
1989 /* Not a query-style lookup; must ensure the host name is present, and then we
1990 do a check on the name and all its aliases. */
1992 if (sender_host_name == NULL)
1994 HDEBUG(D_host_lookup)
1995 debug_printf("sender host name required, to match against %s\n", ss);
1996 if (host_lookup_failed || host_name_lookup() != OK)
1998 *error = string_sprintf("failed to find host name for %s",
1999 sender_host_address);;
2002 host_build_sender_fullhost();
2005 /* Match on the sender host name, using the general matching function */
2007 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2011 case DEFER: return DEFER;
2014 /* If there are aliases, try matching on them. */
2016 aliases = sender_host_aliases;
2017 while (*aliases != NULL)
2019 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2022 case DEFER: return DEFER;
2031 /*************************************************
2032 * Check a specific host matches a host list *
2033 *************************************************/
2035 /* This function is passed a host list containing items in a number of
2036 different formats and the identity of a host. Its job is to determine whether
2037 the given host is in the set of hosts defined by the list. The host name is
2038 passed as a pointer so that it can be looked up if needed and not already
2039 known. This is commonly the case when called from verify_check_host() to check
2040 an incoming connection. When called from elsewhere the host name should usually
2043 This function is now just a front end to match_check_list(), which runs common
2044 code for scanning a list. We pass it the check_host() function to perform a
2048 listptr pointer to the host list
2049 cache_bits pointer to cache for named lists, or NULL
2050 host_name the host name or NULL, implying use sender_host_name and
2051 sender_host_aliases, looking them up if required
2052 host_address the IP address
2053 valueptr if not NULL, data from a lookup is passed back here
2055 Returns: OK if the host is in the defined set
2056 FAIL if the host is not in the defined set,
2057 DEFER if a data lookup deferred (not a host lookup)
2059 If the host name was needed in order to make a comparison, and could not be
2060 determined from the IP address, the result is FAIL unless the item
2061 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2064 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2065 uschar *host_name, uschar *host_address, uschar **valueptr)
2068 unsigned int *local_cache_bits = cache_bits;
2069 uschar *save_host_address = deliver_host_address;
2070 check_host_block cb;
2071 cb.host_name = host_name;
2072 cb.host_address = host_address;
2074 if (valueptr != NULL) *valueptr = NULL;
2076 /* If the host address starts off ::ffff: it is an IPv6 address in
2077 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2080 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2081 host_address + 7 : host_address;
2083 /* During the running of the check, put the IP address into $host_address. In
2084 the case of calls from the smtp transport, it will already be there. However,
2085 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
2086 the safe side, any existing setting is preserved, though as I write this
2087 (November 2004) I can't see any cases where it is actually needed. */
2089 deliver_host_address = host_address;
2090 rc = match_check_list(
2091 listptr, /* the list */
2092 0, /* separator character */
2093 &hostlist_anchor, /* anchor pointer */
2094 &local_cache_bits, /* cache pointer */
2095 check_host, /* function for testing */
2096 &cb, /* argument for function */
2097 MCL_HOST, /* type of check */
2098 (host_address == sender_host_address)?
2099 US"host" : host_address, /* text for debugging */
2100 valueptr); /* where to pass back data */
2101 deliver_host_address = save_host_address;
2108 /*************************************************
2109 * Check the remote host matches a list *
2110 *************************************************/
2112 /* This is a front end to verify_check_this_host(), created because checking
2113 the remote host is a common occurrence. With luck, a good compiler will spot
2114 the tail recursion and optimize it. If there's no host address, this is
2115 command-line SMTP input - check against an empty string for the address.
2118 listptr pointer to the host list
2120 Returns: the yield of verify_check_this_host(),
2121 i.e. OK, FAIL, or DEFER
2125 verify_check_host(uschar **listptr)
2127 return verify_check_this_host(listptr, sender_host_cache, NULL,
2128 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
2135 /*************************************************
2136 * Invert an IP address for a DNS black list *
2137 *************************************************/
2141 buffer where to put the answer
2142 address the address to invert
2146 invert_address(uschar *buffer, uschar *address)
2149 uschar *bptr = buffer;
2151 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
2152 to the IPv4 part only. */
2154 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
2156 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
2159 if (host_aton(address, bin) == 1)
2163 for (i = 0; i < 4; i++)
2165 sprintf(CS bptr, "%d.", x & 255);
2166 while (*bptr) bptr++;
2171 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
2172 in any DNS black lists, and the format in which they will be looked up is
2173 unknown. This is just a guess. */
2179 for (j = 3; j >= 0; j--)
2182 for (i = 0; i < 8; i++)
2184 sprintf(CS bptr, "%x.", x & 15);
2185 while (*bptr) bptr++;
2195 /*************************************************
2196 * Perform a single dnsbl lookup *
2197 *************************************************/
2199 /* This function is called from verify_check_dnsbl() below.
2202 domain the outer dnsbl domain (for debug message)
2203 keydomain the current keydomain (for debug message)
2204 query the domain to be looked up
2205 iplist the list of matching IP addresses
2206 bitmask true if bitmask matching is wanted
2207 invert_result true if result to be inverted
2208 defer_return what to return for a defer
2210 Returns: OK if lookup succeeded
2215 one_check_dnsbl(uschar *domain, uschar *keydomain, uschar *query,
2216 uschar *iplist, BOOL bitmask, BOOL invert_result, int defer_return)
2221 dnsbl_cache_block *cb;
2222 int old_pool = store_pool;
2224 /* Look for this query in the cache. */
2226 t = tree_search(dnsbl_cache, query);
2228 /* If not cached from a previous lookup, we must do a DNS lookup, and
2229 cache the result in permanent memory. */
2233 store_pool = POOL_PERM;
2235 /* Set up a tree entry to cache the lookup */
2237 t = store_get(sizeof(tree_node) + Ustrlen(query));
2238 Ustrcpy(t->name, query);
2239 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
2240 (void)tree_insertnode(&dnsbl_cache, t);
2242 /* Do the DNS loopup . */
2244 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
2245 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
2246 cb->text_set = FALSE;
2250 /* If the lookup succeeded, cache the RHS address. The code allows for
2251 more than one address - this was for complete generality and the possible
2252 use of A6 records. However, A6 records have been reduced to experimental
2253 status (August 2001) and may die out. So they may never get used at all,
2254 let alone in dnsbl records. However, leave the code here, just in case.
2256 Quite apart from one A6 RR generating multiple addresses, there are DNS
2257 lists that return more than one A record, so we must handle multiple
2258 addresses generated in that way as well. */
2260 if (cb->rc == DNS_SUCCEED)
2263 dns_address **addrp = &(cb->rhs);
2264 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2266 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2268 if (rr->type == T_A)
2270 dns_address *da = dns_address_from_rr(&dnsa, rr);
2274 while (da->next != NULL) da = da->next;
2275 addrp = &(da->next);
2280 /* If we didn't find any A records, change the return code. This can
2281 happen when there is a CNAME record but there are no A records for what
2284 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
2287 store_pool = old_pool;
2290 /* Previous lookup was cached */
2294 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
2298 /* We now have the result of the DNS lookup, either newly done, or cached
2299 from a previous call. If the lookup succeeded, check against the address
2300 list if there is one. This may be a positive equality list (introduced by
2301 "="), a negative equality list (introduced by "!="), a positive bitmask
2302 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
2304 if (cb->rc == DNS_SUCCEED)
2306 dns_address *da = NULL;
2307 uschar *addlist = cb->rhs->address;
2309 /* For A and AAAA records, there may be multiple addresses from multiple
2310 records. For A6 records (currently not expected to be used) there may be
2311 multiple addresses from a single record. */
2313 for (da = cb->rhs->next; da != NULL; da = da->next)
2314 addlist = string_sprintf("%s, %s", addlist, da->address);
2316 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
2319 /* Address list check; this can be either for equality, or via a bitmask.
2320 In the latter case, all the bits must match. */
2326 uschar *ptr = iplist;
2328 while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL)
2330 /* Handle exact matching */
2333 for (da = cb->rhs; da != NULL; da = da->next)
2335 if (Ustrcmp(CS da->address, ip) == 0) break;
2338 /* Handle bitmask matching */
2344 /* At present, all known DNS blocking lists use A records, with
2345 IPv4 addresses on the RHS encoding the information they return. I
2346 wonder if this will linger on as the last vestige of IPv4 when IPv6
2347 is ubiquitous? Anyway, for now we use paranoia code to completely
2348 ignore IPv6 addresses. The default mask is 0, which always matches.
2349 We change this only for IPv4 addresses in the list. */
2351 if (host_aton(ip, address) == 1) mask = address[0];
2353 /* Scan the returned addresses, skipping any that are IPv6 */
2355 for (da = cb->rhs; da != NULL; da = da->next)
2357 if (host_aton(da->address, address) != 1) continue;
2358 if ((address[0] & mask) == mask) break;
2362 /* Break out if a match has been found */
2364 if (da != NULL) break;
2369 (a) No IP address in a positive list matched, or
2370 (b) An IP address in a negative list did match
2372 then behave as if the DNSBL lookup had not succeeded, i.e. the host is
2375 if (invert_result != (da == NULL))
2379 debug_printf("=> but we are not accepting this block class because\n");
2380 debug_printf("=> there was %s match for %c%s\n",
2381 invert_result? "an exclude":"no", bitmask? '&' : '=', iplist);
2387 /* Either there was no IP list, or the record matched. Look up a TXT record
2388 if it hasn't previously been done. */
2392 cb->text_set = TRUE;
2393 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
2396 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2398 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2399 if (rr->type == T_TXT) break;
2402 int len = (rr->data)[0];
2403 if (len > 511) len = 127;
2404 store_pool = POOL_PERM;
2405 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
2406 store_pool = old_pool;
2411 dnslist_value = addlist;
2412 dnslist_text = cb->text;
2416 /* There was a problem with the DNS lookup */
2418 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
2420 log_write(L_dnslist_defer, LOG_MAIN,
2421 "DNS list lookup defer (probably timeout) for %s: %s", query,
2422 (defer_return == OK)? US"assumed in list" :
2423 (defer_return == FAIL)? US"assumed not in list" :
2424 US"returned DEFER");
2425 return defer_return;
2428 /* No entry was found in the DNS; continue for next domain */
2432 debug_printf("DNS lookup for %s failed\n", query);
2433 debug_printf("=> that means %s is not listed at %s\n",
2443 /*************************************************
2444 * Check host against DNS black lists *
2445 *************************************************/
2447 /* This function runs checks against a list of DNS black lists, until one
2448 matches. Each item on the list can be of the form
2450 domain=ip-address/key
2452 The domain is the right-most domain that is used for the query, for example,
2453 blackholes.mail-abuse.org. If the IP address is present, there is a match only
2454 if the DNS lookup returns a matching IP address. Several addresses may be
2455 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
2457 If no key is given, what is looked up in the domain is the inverted IP address
2458 of the current client host. If a key is given, it is used to construct the
2459 domain for the lookup. For example,
2461 dsn.rfc-ignorant.org/$sender_address_domain
2463 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
2464 then we check for a TXT record for an error message, and if found, save its
2465 value in $dnslist_text. We also cache everything in a tree, to optimize
2468 Note: an address for testing RBL is 192.203.178.39
2469 Note: an address for testing DUL is 192.203.178.4
2470 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
2473 listptr the domain/address/data list
2475 Returns: OK successful lookup (i.e. the address is on the list), or
2476 lookup deferred after +include_unknown
2477 FAIL name not found, or no data found for the given type, or
2478 lookup deferred after +exclude_unknown (default)
2479 DEFER lookup failure, if +defer_unknown was set
2483 verify_check_dnsbl(uschar **listptr)
2486 int defer_return = FAIL;
2487 BOOL invert_result = FALSE;
2488 uschar *list = *listptr;
2491 uschar buffer[1024];
2492 uschar query[256]; /* DNS domain max length */
2493 uschar revadd[128]; /* Long enough for IPv6 address */
2495 /* Indicate that the inverted IP address is not yet set up */
2499 /* In case this is the first time the DNS resolver is being used. */
2501 dns_init(FALSE, FALSE);
2503 /* Loop through all the domains supplied, until something matches */
2505 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
2509 BOOL bitmask = FALSE;
2513 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
2515 /* Deal with special values that change the behaviour on defer */
2517 if (domain[0] == '+')
2519 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
2520 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
2521 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
2523 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
2528 /* See if there's explicit data to be looked up */
2530 key = Ustrchr(domain, '/');
2531 if (key != NULL) *key++ = 0;
2533 /* See if there's a list of addresses supplied after the domain name. This is
2534 introduced by an = or a & character; if preceded by ! we invert the result.
2537 iplist = Ustrchr(domain, '=');
2541 iplist = Ustrchr(domain, '&');
2546 if (iplist > domain && iplist[-1] == '!')
2548 invert_result = TRUE;
2554 /* Check that what we have left is a sensible domain name. There is no reason
2555 why these domains should in fact use the same syntax as hosts and email
2556 domains, but in practice they seem to. However, there is little point in
2557 actually causing an error here, because that would no doubt hold up incoming
2558 mail. Instead, I'll just log it. */
2560 for (s = domain; *s != 0; s++)
2562 if (!isalnum(*s) && *s != '-' && *s != '.')
2564 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
2565 "strange characters - is this right?", domain);
2570 /* If there is no key string, construct the query by adding the domain name
2571 onto the inverted host address, and perform a single DNS lookup. */
2575 if (sender_host_address == NULL) return FAIL; /* can never match */
2576 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
2577 frc = string_format(query, sizeof(query), "%s%s", revadd, domain);
2581 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2582 "(ignored): %s...", query);
2586 rc = one_check_dnsbl(domain, sender_host_address, query, iplist, bitmask,
2587 invert_result, defer_return);
2591 dnslist_domain = string_copy(domain);
2592 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
2593 sender_host_address, domain);
2596 if (rc != FAIL) return rc; /* OK or DEFER */
2599 /* If there is a key string, it can be a list of domains or IP addresses to
2600 be concatenated with the main domain. */
2607 uschar keybuffer[256];
2609 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
2610 sizeof(keybuffer))) != NULL)
2612 if (string_is_ip_address(keydomain, NULL) > 0)
2614 uschar keyrevadd[128];
2615 invert_address(keyrevadd, keydomain);
2616 frc = string_format(query, sizeof(query), "%s%s", keyrevadd, domain);
2620 frc = string_format(query, sizeof(query), "%s.%s", keydomain, domain);
2625 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2626 "(ignored): %s...", query);
2630 rc = one_check_dnsbl(domain, keydomain, query, iplist, bitmask,
2631 invert_result, defer_return);
2635 dnslist_domain = string_copy(domain);
2636 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
2641 /* If the lookup deferred, remember this fact. We keep trying the rest
2642 of the list to see if we get a useful result, and if we don't, we return
2643 DEFER at the end. */
2645 if (rc == DEFER) defer = TRUE;
2646 } /* continue with next keystring domain/address */
2648 if (defer) return DEFER;
2650 } /* continue with next dnsdb outer domain */
2655 /* End of verify.c */