1 /* $Cambridge: exim/src/src/verify.c,v 1.3 2004/11/05 16:53:28 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2004 */
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 uschar *helo = US"HELO";
381 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
382 uschar inbuffer[4096];
383 uschar outbuffer[1024];
384 uschar responsebuffer[4096];
386 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
387 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
389 /* Skip this host if we don't have an IP address for it. */
391 if (host->address == NULL)
393 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
398 /* Check the overall callout timeout */
400 if (time(NULL) - callout_start_time >= callout_overall)
402 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
406 /* Set IPv4 or IPv6 */
408 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
410 /* Expand and interpret the interface and port strings. This has to
411 be delayed till now, because they may expand differently for different
412 hosts. If there's a failure, log it, but carry on with the defaults. */
414 deliver_host = host->name;
415 deliver_host_address = host->address;
416 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
418 !smtp_get_port(tf->port, addr, &port, US"callout"))
419 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
421 deliver_host = deliver_host_address = NULL;
423 /* Set HELO string according to the protocol */
425 if (Ustrcmp(tf->protocol, "lmtp") == 0) helo = US"LHLO";
427 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
429 /* Set up the buffer for reading SMTP response packets. */
431 inblock.buffer = inbuffer;
432 inblock.buffersize = sizeof(inbuffer);
433 inblock.ptr = inbuffer;
434 inblock.ptrend = inbuffer;
436 /* Set up the buffer for holding SMTP commands while pipelining */
438 outblock.buffer = outbuffer;
439 outblock.buffersize = sizeof(outbuffer);
440 outblock.ptr = outbuffer;
441 outblock.cmd_count = 0;
442 outblock.authenticating = FALSE;
444 /* Connect to the host; on failure, just loop for the next one, but we
445 set the error for the last one. Use the callout_connect timeout. */
447 inblock.sock = outblock.sock =
448 smtp_connect(host, host_af, port, interface, callout_connect, TRUE);
449 if (inblock.sock < 0)
451 addr->message = string_sprintf("could not connect to %s [%s]: %s",
452 host->name, host->address, strerror(errno));
456 /* Wait for initial response, and then run the initial SMTP commands. The
457 smtp_write_command() function leaves its command in big_buffer. This is
458 used in error responses. Initialize it in case the connection is
461 Ustrcpy(big_buffer, "initial connection");
464 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
467 smtp_write_command(&outblock, FALSE, "%s %s\r\n", helo,
468 smtp_active_hostname) >= 0 &&
469 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
472 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
473 from_address) >= 0 &&
474 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
477 /* If the host gave an initial error, or does not accept HELO or MAIL
478 FROM:<>, arrange to cache this information, but don't record anything for an
479 I/O error or a defer. Do not cache rejections when a non-empty sender has
480 been used, because that blocks the whole domain for all senders. */
484 *failure_ptr = US"mail";
485 if (errno == 0 && responsebuffer[0] == '5')
487 setflag(addr, af_verify_nsfail);
488 if (from_address[0] == 0) new_domain_record.result = ccache_reject;
492 /* Otherwise, proceed to check a "random" address (if required), then the
493 given address, and the postmaster address (if required). Between each check,
494 issue RSET, because some servers accept only one recipient after MAIL
499 new_domain_record.result = ccache_accept;
501 /* Do the random local part check first */
503 if (random_local_part != NULL)
505 uschar randombuffer[1024];
507 smtp_write_command(&outblock, FALSE,
508 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
509 addr->domain) >= 0 &&
510 smtp_read_response(&inblock, randombuffer,
511 sizeof(randombuffer), '2', callout);
513 /* Remember when we last did a random test */
515 new_domain_record.random_stamp = time(NULL);
517 /* If accepted, we aren't going to do any further tests below. */
521 new_domain_record.random_result = ccache_accept;
524 /* Otherwise, cache a real negative response, and get back to the right
525 state to send RCPT. Unless there's some problem such as a dropped
526 connection, we expect to succeed, because the commands succeeded above. */
530 if (randombuffer[0] == '5')
531 new_domain_record.random_result = ccache_reject;
534 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
535 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
538 smtp_write_command(&outblock, FALSE, "MAIL FROM:<>\r\n") >= 0 &&
539 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
542 else done = FALSE; /* Some timeout/connection problem */
545 /* If the host is accepting all local parts, as determined by the "random"
546 check, we don't need to waste time doing any further checking. */
548 if (new_domain_record.random_result != ccache_accept && done)
551 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
552 addr->address) >= 0 &&
553 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
557 new_address_record.result = ccache_accept;
558 else if (errno == 0 && responsebuffer[0] == '5')
560 *failure_ptr = US"recipient";
561 new_address_record.result = ccache_reject;
564 /* Do postmaster check if requested */
566 if (done && pm_mailfrom != NULL)
569 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
570 smtp_read_response(&inblock, responsebuffer,
571 sizeof(responsebuffer), '2', callout) &&
573 smtp_write_command(&outblock, FALSE,
574 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
575 smtp_read_response(&inblock, responsebuffer,
576 sizeof(responsebuffer), '2', callout) &&
578 smtp_write_command(&outblock, FALSE,
579 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
580 smtp_read_response(&inblock, responsebuffer,
581 sizeof(responsebuffer), '2', callout);
583 new_domain_record.postmaster_stamp = time(NULL);
586 new_domain_record.postmaster_result = ccache_accept;
587 else if (errno == 0 && responsebuffer[0] == '5')
589 *failure_ptr = US"postmaster";
590 setflag(addr, af_verify_pmfail);
591 new_domain_record.postmaster_result = ccache_reject;
594 } /* Random not accepted */
595 } /* MAIL FROM:<> accepted */
597 /* For any failure of the main check, other than a negative response, we just
598 close the connection and carry on. We can identify a negative response by the
599 fact that errno is zero. For I/O errors it will be non-zero
601 Set up different error texts for logging and for sending back to the caller
602 as an SMTP response. Log in all cases, using a one-line format. For sender
603 callouts, give a full response to the caller, but for recipient callouts,
604 don't give the IP address because this may be an internal host whose identity
605 is not to be widely broadcast. */
609 if (errno == ETIMEDOUT)
611 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
615 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
618 string_sprintf("response to \"%s\" from %s [%s] was: %s",
619 big_buffer, host->name, host->address,
620 string_printing(responsebuffer));
622 addr->user_message = is_recipient?
623 string_sprintf("Callout verification failed:\n%s", responsebuffer)
625 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
626 host->address, big_buffer, responsebuffer);
628 /* Hard rejection ends the process */
630 if (responsebuffer[0] == '5') /* Address rejected */
638 /* End the SMTP conversation and close the connection. */
640 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
642 } /* Loop through all hosts, while !done */
644 /* If we get here with done == TRUE, a successful callout happened, and yield
645 will be set OK or FAIL according to the response to the RCPT command.
646 Otherwise, we looped through the hosts but couldn't complete the business.
647 However, there may be domain-specific information to cache in both cases.
649 The value of the result field in the new_domain record is ccache_unknown if
650 there was an error before or with MAIL FROM:<>, and errno was not zero,
651 implying some kind of I/O error. We don't want to write the cache in that case.
652 Otherwise the value is ccache_accept or ccache_reject. */
654 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
656 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
659 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
663 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
664 (int)sizeof(dbdata_callout_cache));
665 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
666 " result=%d postmaster=%d random=%d\n",
667 new_domain_record.result,
668 new_domain_record.postmaster_result,
669 new_domain_record.random_result);
673 /* If a definite result was obtained for the callout, cache it unless caching
678 if (!callout_no_cache && new_address_record.result != ccache_unknown)
680 if (dbm_file == NULL)
681 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
682 if (dbm_file == NULL)
684 HDEBUG(D_verify) debug_printf("no callout cache available\n");
688 (void)dbfn_write(dbm_file, address_key, &new_address_record,
689 (int)sizeof(dbdata_callout_cache_address));
690 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
691 (new_address_record.result == ccache_accept)? "positive" : "negative");
696 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
697 temporary error. If there was only one host, and a response was received, leave
698 it alone if supplying details. Otherwise, give a generic response. */
702 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
703 is_recipient? "recipient" : "sender");
706 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
708 addr->user_message = (!smtp_return_error_details)? dullmsg :
709 string_sprintf("%s for <%s>.\n"
710 "The mail server(s) for the domain may be temporarily unreachable, or\n"
711 "they may be permanently unreachable from this server. In the latter case,\n%s",
712 dullmsg, addr->address,
714 "the address will never be accepted."
716 "you need to change the address or create an MX record for its domain\n"
717 "if it is supposed to be generally accessible from the Internet.\n"
718 "Talk to your mail administrator for details.");
720 /* Force a specific error code */
722 addr->basic_errno = ERRNO_CALLOUTDEFER;
725 /* Come here from within the cache-reading code on fast-track exit. */
728 if (dbm_file != NULL) dbfn_close(dbm_file);
734 /*************************************************
735 * Copy error to toplevel address *
736 *************************************************/
738 /* This function is used when a verify fails or defers, to ensure that the
739 failure or defer information is in the original toplevel address. This applies
740 when an address is redirected to a single new address, and the failure or
741 deferral happens to the child address.
744 vaddr the verify address item
745 addr the final address item
748 Returns: the value of YIELD
752 copy_error(address_item *vaddr, address_item *addr, int yield)
756 vaddr->message = addr->message;
757 vaddr->user_message = addr->user_message;
758 vaddr->basic_errno = addr->basic_errno;
759 vaddr->more_errno = addr->more_errno;
767 /*************************************************
768 * Verify an email address *
769 *************************************************/
771 /* This function is used both for verification (-bv and at other times) and
772 address testing (-bt), which is indicated by address_test_mode being set.
775 vaddr contains the address to verify; the next field in this block
777 f if not NULL, write the result to this file
778 options various option bits:
779 vopt_fake_sender => this sender verify is not for the real
780 sender (it was verify=sender=xxxx or an address from a
781 header line) - rewriting must not change sender_address
782 vopt_is_recipient => this is a recipient address, otherwise
783 it's a sender address - this affects qualification and
784 rewriting and messages from callouts
785 vopt_qualify => qualify an unqualified address; else error
786 vopt_expn => called from SMTP EXPN command
788 These ones are used by do_callout() -- the options variable
791 vopt_callout_no_cache => don't use callout cache
792 vopt_callout_random => do the "random" thing
793 vopt_callout_recipsender => use real sender for recipient
794 vopt_callout_recippmaster => use postmaster for recipient
796 callout if > 0, specifies that callout is required, and gives timeout
797 for individual commands
798 callout_overall if > 0, gives overall timeout for the callout function;
799 if < 0, a default is used (see do_callout())
800 callout_connect the connection timeout for callouts
801 se_mailfrom when callout is requested to verify a sender, use this
802 in MAIL FROM; NULL => ""
803 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
804 thing and use this as the sender address (may be "")
806 routed if not NULL, set TRUE if routing succeeded, so we can
807 distinguish between routing failed and callout failed
809 Returns: OK address verified
810 FAIL address failed to verify
811 DEFER can't tell at present
815 verify_address(address_item *vaddr, FILE *f, int options, int callout,
816 int callout_overall, int callout_connect, uschar *se_mailfrom,
817 uschar *pm_mailfrom, BOOL *routed)
820 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
821 BOOL is_recipient = (options & vopt_is_recipient) != 0;
822 BOOL expn = (options & vopt_expn) != 0;
825 int verify_type = expn? v_expn :
826 address_test_mode? v_none :
827 is_recipient? v_recipient : v_sender;
828 address_item *addr_list;
829 address_item *addr_new = NULL;
830 address_item *addr_remote = NULL;
831 address_item *addr_local = NULL;
832 address_item *addr_succeed = NULL;
833 uschar **failure_ptr = is_recipient?
834 &recipient_verify_failure : &sender_verify_failure;
835 uschar *ko_prefix, *cr;
836 uschar *address = vaddr->address;
838 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
840 /* Clear, just in case */
844 /* Set up a prefix and suffix for error message which allow us to use the same
845 output statements both in EXPN mode (where an SMTP response is needed) and when
846 debugging with an output file. */
850 ko_prefix = US"553 ";
853 else ko_prefix = cr = US"";
855 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
857 if (parse_find_at(address) == NULL)
859 if ((options & vopt_qualify) == 0)
862 fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address,
864 *failure_ptr = US"qualify";
867 address = rewrite_address_qualify(address, is_recipient);
872 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
873 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
876 /* Rewrite and report on it. Clear the domain and local part caches - these
877 may have been set by domains and local part tests during an ACL. */
879 if (global_rewrite_rules != NULL)
881 uschar *old = address;
882 address = rewrite_address(address, is_recipient, FALSE,
883 global_rewrite_rules, rewrite_existflags);
886 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
887 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
888 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
892 /* If this is the real sender address, we must update sender_address at
893 this point, because it may be referred to in the routers. */
895 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
896 sender_address = address;
898 /* If the address was rewritten to <> no verification can be done, and we have
899 to return OK. This rewriting is permitted only for sender addresses; for other
900 addresses, such rewriting fails. */
902 if (address[0] == 0) return OK;
904 /* Save a copy of the sender address for re-instating if we change it to <>
905 while verifying a sender address (a nice bit of self-reference there). */
907 save_sender = sender_address;
909 /* Update the address structure with the possibly qualified and rewritten
910 address. Set it up as the starting address on the chain of new addresses. */
912 vaddr->address = address;
915 /* We need a loop, because an address can generate new addresses. We must also
916 cope with generated pipes and files at the top level. (See also the code and
917 comment in deliver.c.) However, it is usually the case that the router for
918 user's .forward files has its verify flag turned off.
920 If an address generates more than one child, the loop is used only when
921 full_info is set, and this can only be set locally. Remote enquiries just get
922 information about the top level address, not anything that it generated. */
924 while (addr_new != NULL)
927 address_item *addr = addr_new;
929 addr_new = addr->next;
934 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
935 debug_printf("Considering %s\n", addr->address);
938 /* Handle generated pipe, file or reply addresses. We don't get these
939 when handling EXPN, as it does only one level of expansion. */
941 if (testflag(addr, af_pfr))
948 if (addr->address[0] == '>')
950 allow = testflag(addr, af_allow_reply);
951 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
955 allow = (addr->address[0] == '|')?
956 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
957 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
960 if (addr->basic_errno == ERRNO_BADTRANSPORT)
961 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
962 "%s\n", addr->message);
964 fprintf(f, "\n transport = %s\n", addr->transport->name);
966 fprintf(f, " *** forbidden ***\n");
971 /* Just in case some router parameter refers to it. */
973 return_path = (addr->p.errors_address != NULL)?
974 addr->p.errors_address : sender_address;
976 /* Split the address into domain and local part, handling the %-hack if
977 necessary, and then route it. While routing a sender address, set
978 $sender_address to <> because that is what it will be if we were trying to
979 send a bounce to the sender. */
981 if (routed != NULL) *routed = FALSE;
982 if ((rc = deliver_split_address(addr)) == OK)
984 if (!is_recipient) sender_address = null_sender;
985 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
986 &addr_succeed, verify_type);
987 sender_address = save_sender; /* Put back the real sender */
990 /* If routing an address succeeded, set the flag that remembers, for use when
991 an ACL cached a sender verify (in case a callout fails). Then if routing set
992 up a list of hosts or the transport has a host list, and the callout option
993 is set, and we aren't in a host checking run, do the callout verification,
994 and set another flag that notes that a callout happened. */
998 if (routed != NULL) *routed = TRUE;
1001 host_item *host_list = addr->host_list;
1003 /* Default, if no remote transport, to NULL for the interface (=> any),
1004 "smtp" for the port, and "smtp" for the protocol. */
1006 transport_feedback tf = { NULL, US"smtp", US"smtp", NULL, FALSE, FALSE };
1008 /* If verification yielded a remote transport, we want to use that
1009 transport's options, so as to mimic what would happen if we were really
1010 sending a message to this address. */
1012 if (addr->transport != NULL && !addr->transport->info->local)
1014 (void)(addr->transport->setup)(addr->transport, addr, &tf, NULL);
1016 /* If the transport has hosts and the router does not, or if the
1017 transport is configured to override the router's hosts, we must build a
1018 host list of the transport's hosts, and find the IP addresses */
1020 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1024 host_list = NULL; /* Ignore the router's hosts */
1026 deliver_domain = addr->domain;
1027 deliver_localpart = addr->local_part;
1028 s = expand_string(tf.hosts);
1029 deliver_domain = deliver_localpart = NULL;
1033 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1034 "\"%s\" in %s transport for callout: %s", tf.hosts,
1035 addr->transport->name, expand_string_message);
1039 uschar *canonical_name;
1041 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1043 /* Just ignore failures to find a host address. If we don't manage
1044 to find any addresses, the callout will defer. */
1046 for (host = host_list; host != NULL; host = host->next)
1048 if (tf.gethostbyname || string_is_ip_address(host->name, NULL))
1049 (void)host_find_byname(host, NULL, &canonical_name, TRUE);
1052 int flags = HOST_FIND_BY_A;
1053 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1054 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1055 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1056 &canonical_name, NULL);
1063 /* Can only do a callout if we have at least one host! If the callout
1064 fails, it will have set ${sender,recipient}_verify_failure. */
1066 if (host_list != NULL)
1068 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1069 if (host_checking && !host_checking_callout)
1072 debug_printf("... callout omitted by default when host testing\n"
1073 "(Use -bhc if you want the callouts to happen.)\n");
1077 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1078 callout_connect, options, se_mailfrom, pm_mailfrom);
1083 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1084 "transport provided a host list\n");
1089 /* Otherwise, any failure is a routing failure */
1091 else *failure_ptr = US"route";
1093 /* A router may return REROUTED if it has set up a child address as a result
1094 of a change of domain name (typically from widening). In this case we always
1095 want to continue to verify the new child. */
1097 if (rc == REROUTED) continue;
1099 /* Handle hard failures */
1106 fprintf(f, "%s%s %s", ko_prefix, address,
1107 address_test_mode? "is undeliverable" : "failed to verify");
1108 if (!expn && admin_user)
1110 if (addr->basic_errno > 0)
1111 fprintf(f, ": %s", strerror(addr->basic_errno));
1112 if (addr->message != NULL)
1113 fprintf(f, ":\n %s", addr->message);
1115 fprintf(f, "%s\n", cr);
1118 if (!full_info) return copy_error(vaddr, addr, FAIL);
1124 else if (rc == DEFER)
1129 fprintf(f, "%s%s cannot be resolved at this time", ko_prefix, address);
1130 if (!expn && admin_user)
1132 if (addr->basic_errno > 0)
1133 fprintf(f, ":\n %s", strerror(addr->basic_errno));
1134 if (addr->message != NULL)
1135 fprintf(f, ":\n %s", addr->message);
1136 else if (addr->basic_errno <= 0)
1137 fprintf(f, ":\n unknown error");
1140 fprintf(f, "%s\n", cr);
1142 if (!full_info) return copy_error(vaddr, addr, DEFER);
1143 else if (yield == OK) yield = DEFER;
1146 /* If we are handling EXPN, we do not want to continue to route beyond
1151 uschar *ok_prefix = US"250-";
1152 if (addr_new == NULL)
1154 if (addr_local == NULL && addr_remote == NULL)
1155 fprintf(f, "250 mail to <%s> is discarded\r\n", address);
1157 fprintf(f, "250 <%s>\r\n", address);
1159 else while (addr_new != NULL)
1161 address_item *addr2 = addr_new;
1162 addr_new = addr2->next;
1163 if (addr_new == NULL) ok_prefix = US"250 ";
1164 fprintf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1169 /* Successful routing other than EXPN. */
1173 /* Handle successful routing when short info wanted. Otherwise continue for
1174 other (generated) addresses. Short info is the operational case. Full info
1175 can be requested only when debug_selector != 0 and a file is supplied.
1177 There is a conflict between the use of aliasing as an alternate email
1178 address, and as a sort of mailing list. If an alias turns the incoming
1179 address into just one address (e.g. J.Caesar->jc44) you may well want to
1180 carry on verifying the generated address to ensure it is valid when
1181 checking incoming mail. If aliasing generates multiple addresses, you
1182 probably don't want to do this. Exim therefore treats the generation of
1183 just a single new address as a special case, and continues on to verify the
1184 generated address. */
1186 if (!full_info && /* Stop if short info wanted AND */
1187 (addr_new == NULL || /* No new address OR */
1188 addr_new->next != NULL || /* More than one new address OR */
1189 testflag(addr_new, af_pfr))) /* New address is pfr */
1191 if (f != NULL) fprintf(f, "%s %s\n", address,
1192 address_test_mode? "is deliverable" : "verified");
1194 /* If we have carried on to verify a child address, we want the value
1195 of $address_data to be that of the child */
1197 vaddr->p.address_data = addr->p.address_data;
1201 } /* Loop for generated addresses */
1203 /* Display the full results of the successful routing, including any generated
1204 addresses. Control gets here only when full_info is set, which requires f not
1205 to be NULL, and this occurs only when a top-level verify is called with the
1206 debugging switch on.
1208 If there are no local and no remote addresses, and there were no pipes, files,
1209 or autoreplies, and there were no errors or deferments, the message is to be
1210 discarded, usually because of the use of :blackhole: in an alias file. */
1212 if (allok && addr_local == NULL && addr_remote == NULL)
1213 fprintf(f, "mail to %s is discarded\n", address);
1215 else for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1217 while (addr_list != NULL)
1219 address_item *addr = addr_list;
1220 address_item *p = addr->parent;
1221 addr_list = addr->next;
1223 fprintf(f, "%s", CS addr->address);
1226 fprintf(f, "\n <-- %s", p->address);
1231 /* Show router, and transport */
1233 fprintf(f, "router = %s, ", addr->router->name);
1234 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1235 addr->transport->name);
1237 /* Show any hosts that are set up by a router unless the transport
1238 is going to override them; fiddle a bit to get a nice format. */
1240 if (addr->host_list != NULL && addr->transport != NULL &&
1241 !addr->transport->overrides_hosts)
1246 for (h = addr->host_list; h != NULL; h = h->next)
1248 int len = Ustrlen(h->name);
1249 if (len > maxlen) maxlen = len;
1250 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1251 if (len > maxaddlen) maxaddlen = len;
1253 for (h = addr->host_list; h != NULL; h = h->next)
1255 int len = Ustrlen(h->name);
1256 fprintf(f, " host %s ", h->name);
1257 while (len++ < maxlen) fprintf(f, " ");
1258 if (h->address != NULL)
1260 fprintf(f, "[%s] ", h->address);
1261 len = Ustrlen(h->address);
1263 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1265 fprintf(f, "[unknown] ");
1269 while (len++ < maxaddlen) fprintf(f," ");
1270 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1271 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1272 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1279 /* Will be DEFER or FAIL if any one address has, only for full_info (which is
1280 the -bv or -bt case). */
1288 /*************************************************
1289 * Check headers for syntax errors *
1290 *************************************************/
1292 /* This function checks those header lines that contain addresses, and verifies
1293 that all the addresses therein are syntactially correct.
1296 msgptr where to put an error message
1303 verify_check_headers(uschar **msgptr)
1308 for (h = header_list; h != NULL; h = h->next)
1310 if (h->type != htype_from &&
1311 h->type != htype_reply_to &&
1312 h->type != htype_sender &&
1313 h->type != htype_to &&
1314 h->type != htype_cc &&
1315 h->type != htype_bcc)
1318 colon = Ustrchr(h->text, ':');
1320 while (isspace(*s)) s++;
1322 parse_allow_group = TRUE; /* Allow group syntax */
1324 /* Loop for multiple addresses in the header */
1328 uschar *ss = parse_find_address_end(s, FALSE);
1329 uschar *recipient, *errmess;
1330 int terminator = *ss;
1331 int start, end, domain;
1333 /* Temporarily terminate the string at this point, and extract the
1334 operative address within. */
1337 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
1340 /* Permit an unqualified address only if the message is local, or if the
1341 sending host is configured to be permitted to send them. */
1343 if (recipient != NULL && domain == 0)
1345 if (h->type == htype_from || h->type == htype_sender)
1347 if (!allow_unqualified_sender) recipient = NULL;
1351 if (!allow_unqualified_recipient) recipient = NULL;
1353 if (recipient == NULL) errmess = US"unqualified address not permitted";
1356 /* It's an error if no address could be extracted, except for the special
1357 case of an empty address. */
1359 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
1361 uschar *verb = US"is";
1365 /* Arrange not to include any white space at the end in the
1368 while (t > s && isspace(t[-1])) t--;
1370 /* Add the address which failed to the error message, since in a
1371 header with very many addresses it is sometimes hard to spot
1372 which one is at fault. However, limit the amount of address to
1373 quote - cases have been seen where, for example, a missing double
1374 quote in a humungous To: header creates an "address" that is longer
1375 than string_sprintf can handle. */
1384 *msgptr = string_printing(
1385 string_sprintf("%s: failing address in \"%.*s\" header %s: %.*s",
1386 errmess, colon - h->text, h->text, verb, len, s));
1391 /* Advance to the next address */
1393 s = ss + (terminator? 1:0);
1394 while (isspace(*s)) s++;
1395 } /* Next address */
1404 /*************************************************
1405 * Find if verified sender *
1406 *************************************************/
1408 /* Usually, just a single address is verified as the sender of the message.
1409 However, Exim can be made to verify other addresses as well (often related in
1410 some way), and this is useful in some environments. There may therefore be a
1411 chain of such addresses that have previously been tested. This function finds
1412 whether a given address is on the chain.
1414 Arguments: the address to be verified
1415 Returns: pointer to an address item, or NULL
1419 verify_checked_sender(uschar *sender)
1422 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
1423 if (Ustrcmp(sender, addr->address) == 0) break;
1431 /*************************************************
1432 * Get valid header address *
1433 *************************************************/
1435 /* Scan the originator headers of the message, looking for an address that
1436 verifies successfully. RFC 822 says:
1438 o The "Sender" field mailbox should be sent notices of
1439 any problems in transport or delivery of the original
1440 messages. If there is no "Sender" field, then the
1441 "From" field mailbox should be used.
1443 o If the "Reply-To" field exists, then the reply should
1444 go to the addresses indicated in that field and not to
1445 the address(es) indicated in the "From" field.
1447 So we check a Sender field if there is one, else a Reply_to field, else a From
1448 field. As some strange messages may have more than one of these fields,
1449 especially if they are resent- fields, check all of them if there is more than
1453 user_msgptr points to where to put a user error message
1454 log_msgptr points to where to put a log error message
1455 callout timeout for callout check (passed to verify_address())
1456 callout_overall overall callout timeout (ditto)
1457 callout_connect connect callout timeout (ditto)
1458 se_mailfrom mailfrom for verify; NULL => ""
1459 pm_mailfrom sender for pm callout check (passed to verify_address())
1460 options callout options (passed to verify_address())
1462 If log_msgptr is set to something without setting user_msgptr, the caller
1463 normally uses log_msgptr for both things.
1465 Returns: result of the verification attempt: OK, FAIL, or DEFER;
1466 FAIL is given if no appropriate headers are found
1470 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
1471 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
1472 uschar *pm_mailfrom, int options)
1474 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
1478 for (i = 0; i < 3; i++)
1481 for (h = header_list; h != NULL; h = h->next)
1483 int terminator, new_ok;
1484 uschar *s, *ss, *endname;
1486 if (h->type != header_types[i]) continue;
1487 s = endname = Ustrchr(h->text, ':') + 1;
1491 address_item *vaddr;
1493 while (isspace(*s) || *s == ',') s++;
1494 if (*s == 0) break; /* End of header */
1496 ss = parse_find_address_end(s, FALSE);
1498 /* The terminator is a comma or end of header, but there may be white
1499 space preceding it (including newline for the last address). Move back
1500 past any white space so we can check against any cached envelope sender
1501 address verifications. */
1503 while (isspace(ss[-1])) ss--;
1507 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
1508 (int)(endname - h->text), h->text, s);
1510 /* See if we have already verified this address as an envelope sender,
1511 and if so, use the previous answer. */
1513 vaddr = verify_checked_sender(s);
1515 if (vaddr != NULL && /* Previously checked */
1516 (callout <= 0 || /* No callout needed; OR */
1517 vaddr->special_action > 256)) /* Callout was done */
1519 new_ok = vaddr->special_action & 255;
1520 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
1521 *ss = terminator; /* Restore shortened string */
1524 /* Otherwise we run the verification now. We must restore the shortened
1525 string before running the verification, so the headers are correct, in
1526 case there is any rewriting. */
1530 int start, end, domain;
1531 uschar *address = parse_extract_address(s, log_msgptr, &start,
1532 &end, &domain, FALSE);
1536 /* If verification failed because of a syntax error, fail this
1537 function, and ensure that the failing address gets added to the error
1540 if (address == NULL)
1543 if (*log_msgptr != NULL)
1545 while (ss > s && isspace(ss[-1])) ss--;
1546 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
1547 "scanning for sender: %s in \"%.*s\"",
1548 endname - h->text, h->text, *log_msgptr, ss - s, s);
1553 /* Else go ahead with the sender verification. But is isn't *the*
1554 sender of the message, so set vopt_fake_sender to stop sender_address
1555 being replaced after rewriting or qualification. */
1559 vaddr = deliver_make_addr(address, FALSE);
1560 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
1561 callout, callout_overall, callout_connect, se_mailfrom,
1566 /* We now have the result, either newly found, or cached. If we are
1567 giving out error details, set a specific user error. This means that the
1568 last of these will be returned to the user if all three fail. We do not
1569 set a log message - the generic one below will be used. */
1571 if (new_ok != OK && smtp_return_error_details)
1573 *user_msgptr = string_sprintf("Rejected after DATA: "
1574 "could not verify \"%.*s\" header address\n%s: %s",
1575 endname - h->text, h->text, vaddr->address, vaddr->message);
1578 /* Success or defer */
1580 if (new_ok == OK) return OK;
1581 if (new_ok == DEFER) yield = DEFER;
1583 /* Move on to any more addresses in the header */
1590 if (yield == FAIL && *log_msgptr == NULL)
1591 *log_msgptr = US"there is no valid sender in any header line";
1593 if (yield == DEFER && *log_msgptr == NULL)
1594 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
1602 /*************************************************
1603 * Get RFC 1413 identification *
1604 *************************************************/
1606 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
1607 the timeout is set to zero, then the query is not done. There may also be lists
1608 of hosts and nets which are exempt. To guard against malefactors sending
1609 non-printing characters which could, for example, disrupt a message's headers,
1610 make sure the string consists of printing characters only.
1613 port the port to connect to; usually this is IDENT_PORT (113), but when
1614 running in the test harness with -bh a different value is used.
1618 Side effect: any received ident value is put in sender_ident (NULL otherwise)
1622 verify_get_ident(int port)
1624 int sock, host_af, qlen;
1625 int received_sender_port, received_interface_port, n;
1627 uschar buffer[2048];
1629 /* Default is no ident. Check whether we want to do an ident check for this
1632 sender_ident = NULL;
1633 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
1636 DEBUG(D_ident) debug_printf("doing ident callback\n");
1638 /* Set up a connection to the ident port of the remote host. Bind the local end
1639 to the incoming interface address. If the sender host address is an IPv6
1640 address, the incoming interface address will also be IPv6. */
1642 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
1643 sock = ip_socket(SOCK_STREAM, host_af);
1644 if (sock < 0) return;
1646 if (ip_bind(sock, host_af, interface_address, 0) < 0)
1648 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
1653 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
1656 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
1658 log_write(0, LOG_MAIN, "ident connection to %s timed out",
1659 sender_host_address);
1663 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
1664 sender_host_address, strerror(errno));
1669 /* Construct and send the query. */
1671 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
1672 qlen = Ustrlen(buffer);
1673 if (send(sock, buffer, qlen, 0) < 0)
1675 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
1679 /* Read a response line. We put it into the rest of the buffer, using several
1680 recv() calls if necessary. */
1688 int size = sizeof(buffer) - (p - buffer);
1690 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
1691 count = ip_recv(sock, p, size, rfc1413_query_timeout);
1692 if (count <= 0) goto END_OFF; /* Read error or EOF */
1694 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
1695 generous, and accept a plain \n terminator as well. The only illegal
1698 for (pp = p; pp < p + count; pp++)
1700 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
1703 if (pp[-1] == '\r') pp--;
1705 goto GOT_DATA; /* Break out of both loops */
1709 /* Reached the end of the data without finding \n. Let the loop continue to
1710 read some more, if there is room. */
1717 /* We have received a line of data. Check it carefully. It must start with the
1718 same two port numbers that we sent, followed by data as defined by the RFC. For
1721 12345 , 25 : USERID : UNIX :root
1723 However, the amount of white space may be different to what we sent. In the
1724 "osname" field there may be several sub-fields, comma separated. The data we
1725 actually want to save follows the third colon. Some systems put leading spaces
1726 in it - we discard those. */
1728 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
1729 &received_interface_port, &n) != 2 ||
1730 received_sender_port != sender_host_port ||
1731 received_interface_port != interface_port)
1734 p = buffer + qlen + n;
1735 while(isspace(*p)) p++;
1736 if (*p++ != ':') goto END_OFF;
1737 while(isspace(*p)) p++;
1738 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
1740 while(isspace(*p)) p++;
1741 if (*p++ != ':') goto END_OFF;
1742 while (*p != 0 && *p != ':') p++;
1743 if (*p++ == 0) goto END_OFF;
1744 while(isspace(*p)) p++;
1745 if (*p == 0) goto END_OFF;
1747 /* The rest of the line is the data we want. We turn it into printing
1748 characters when we save it, so that it cannot mess up the format of any logging
1749 or Received: lines into which it gets inserted. We keep a maximum of 127
1752 sender_ident = string_printing(string_copyn(p, 127));
1753 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
1763 /*************************************************
1764 * Match host to a single host-list item *
1765 *************************************************/
1767 /* This function compares a host (name or address) against a single item
1768 from a host list. The host name gets looked up if it is needed and is not
1769 already known. The function is called from verify_check_this_host() via
1770 match_check_list(), which is why most of its arguments are in a single block.
1773 arg the argument block (see below)
1774 ss the host-list item
1775 valueptr where to pass back looked up data, or NULL
1776 error for error message when returning ERROR
1779 host_name the host name or NULL, implying use sender_host_name and
1780 sender_host_aliases, looking them up if required
1781 host_address the host address
1782 host_ipv4 the IPv4 address taken from an IPv6 one
1786 DEFER lookup deferred
1787 ERROR failed to find the host name or IP address
1788 unknown lookup type specified
1792 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
1794 check_host_block *cb = (check_host_block *)arg;
1796 BOOL isquery = FALSE;
1797 uschar *semicolon, *t;
1800 /* Optimize for the special case when the pattern is "*". */
1802 if (*ss == '*' && ss[1] == 0) return OK;
1804 /* If the pattern is empty, it matches only in the case when there is no host -
1805 this can occur in ACL checking for SMTP input using the -bs option. In this
1806 situation, the host address is the empty string. */
1808 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
1809 if (*ss == 0) return FAIL;
1811 /* If the pattern is precisely "@" then match against the primary host name;
1812 if it's "@[]" match against the local host's IP addresses. */
1816 if (ss[1] == 0) ss = primary_hostname;
1817 else if (Ustrcmp(ss, "@[]") == 0)
1819 ip_address_item *ip;
1820 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
1821 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
1826 /* If the pattern is an IP address, optionally followed by a bitmask count, do
1827 a (possibly masked) comparision with the current IP address. */
1829 if (string_is_ip_address(ss, &maskoffset))
1830 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
1832 /* If the item is of the form net[n]-lookup;<file|query> then it is a lookup on
1833 a masked IP network, in textual form. The net- stuff really only applies to
1834 single-key lookups where the key is implicit. For query-style lookups the key
1835 is specified in the query. From release 4.30, the use of net- for query style
1836 is no longer needed, but we retain it for backward compatibility. */
1838 if (Ustrncmp(ss, "net", 3) == 0 && (semicolon = Ustrchr(ss, ';')) != NULL)
1841 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
1848 uschar *filename, *key, *result;
1851 /* If no mask was supplied, set a negative value */
1853 if (mlen == 0 && t == ss+4) mlen = -1;
1855 /* Find the search type */
1857 search_type = search_findtype(t, semicolon - t);
1859 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1860 search_error_message);
1862 /* Adjust parameters for the type of lookup. For a query-style
1863 lookup, there is no file name, and the "key" is just the query. For
1864 a single-key lookup, the key is the current IP address, masked
1865 appropriately, and reconverted to text form, with the mask appended. */
1867 if (mac_islookup(search_type, lookup_querystyle))
1870 key = semicolon + 1;
1874 insize = host_aton(cb->host_address, incoming);
1875 host_mask(insize, incoming, mlen);
1876 (void)host_nmtoa(insize, incoming, mlen, buffer);
1878 filename = semicolon + 1;
1881 /* Now do the actual lookup; note that there is no search_close() because
1882 of the caching arrangements. */
1884 handle = search_open(filename, search_type, 0, NULL, NULL);
1885 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1886 search_error_message);
1887 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
1888 if (valueptr != NULL) *valueptr = result;
1889 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
1893 /* The pattern is not an IP address or network reference of any kind. That is,
1894 it is a host name pattern. Check the characters of the pattern to see if they
1895 comprise only letters, digits, full stops, and hyphens (the constituents of
1896 domain names). Allow underscores, as they are all too commonly found. Sigh.
1897 Also, if allow_utf8_domains is set, allow top-bit characters. */
1899 for (t = ss; *t != 0; t++)
1900 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
1901 (!allow_utf8_domains || *t < 128)) break;
1903 /* If the pattern is a complete domain name, with no fancy characters, look up
1904 its IP address and match against that. Note that a multi-homed host will add
1905 items to the chain. */
1915 rc = host_find_byname(&h, NULL, NULL, FALSE);
1916 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1919 for (hh = &h; hh != NULL; hh = hh->next)
1921 if (Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)?
1922 cb->host_ipv4 : cb->host_address) == 0)
1927 if (rc == HOST_FIND_AGAIN) return DEFER;
1928 *error = string_sprintf("failed to find IP address for %s", ss);
1932 /* Almost all subsequent comparisons require the host name, and can be done
1933 using the general string matching function. When this function is called for
1934 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
1935 must use sender_host_name and its aliases, looking them up if necessary. */
1937 if (cb->host_name != NULL) /* Explicit host name given */
1938 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
1941 /* Host name not given; in principle we need the sender host name and its
1942 aliases. However, for query-style lookups, we do not need the name if the
1943 query does not contain $sender_host_name. From release 4.23, a reference to
1944 $sender_host_name causes it to be looked up, so we don't need to do the lookup
1947 if ((semicolon = Ustrchr(ss, ';')) != NULL)
1950 int partial, affixlen, starflags, id;
1953 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
1956 if (id < 0) /* Unknown lookup type */
1958 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
1959 search_error_message, ss);
1962 isquery = mac_islookup(id, lookup_querystyle);
1967 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
1970 case DEFER: return DEFER;
1971 default: return FAIL;
1975 /* Not a query-style lookup; must ensure the host name is present, and then we
1976 do a check on the name and all its aliases. */
1978 if (sender_host_name == NULL)
1980 HDEBUG(D_host_lookup)
1981 debug_printf("sender host name required, to match against %s\n", ss);
1982 if (host_lookup_failed || host_name_lookup() != OK)
1984 *error = string_sprintf("failed to find host name for %s",
1985 sender_host_address);;
1988 host_build_sender_fullhost();
1991 /* Match on the sender host name, using the general matching function */
1993 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
1997 case DEFER: return DEFER;
2000 /* If there are aliases, try matching on them. */
2002 aliases = sender_host_aliases;
2003 while (*aliases != NULL)
2005 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2008 case DEFER: return DEFER;
2017 /*************************************************
2018 * Check a specific host matches a host list *
2019 *************************************************/
2021 /* This function is passed a host list containing items in a number of
2022 different formats and the identity of a host. Its job is to determine whether
2023 the given host is in the set of hosts defined by the list. The host name is
2024 passed as a pointer so that it can be looked up if needed and not already
2025 known. This is commonly the case when called from verify_check_host() to check
2026 an incoming connection. When called from elsewhere the host name should usually
2029 This function is now just a front end to match_check_list(), which runs common
2030 code for scanning a list. We pass it the check_host() function to perform a
2034 listptr pointer to the host list
2035 cache_bits pointer to cache for named lists, or NULL
2036 host_name the host name or NULL, implying use sender_host_name and
2037 sender_host_aliases, looking them up if required
2038 host_address the IP address
2039 valueptr if not NULL, data from a lookup is passed back here
2041 Returns: OK if the host is in the defined set
2042 FAIL if the host is not in the defined set,
2043 DEFER if a data lookup deferred (not a host lookup)
2045 If the host name was needed in order to make a comparison, and could not be
2046 determined from the IP address, the result is FAIL unless the item
2047 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2050 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2051 uschar *host_name, uschar *host_address, uschar **valueptr)
2053 unsigned int *local_cache_bits = cache_bits;
2054 check_host_block cb;
2055 cb.host_name = host_name;
2056 cb.host_address = host_address;
2058 if (valueptr != NULL) *valueptr = NULL;
2060 /* If the host address starts off ::ffff: it is an IPv6 address in
2061 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2064 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2065 host_address + 7 : host_address;
2067 return match_check_list(listptr, 0, &hostlist_anchor, &local_cache_bits,
2068 check_host, &cb, MCL_HOST,
2069 (host_address == sender_host_address)? US"host" : host_address, valueptr);
2075 /*************************************************
2076 * Check the remote host matches a list *
2077 *************************************************/
2079 /* This is a front end to verify_check_this_host(), created because checking
2080 the remote host is a common occurrence. With luck, a good compiler will spot
2081 the tail recursion and optimize it. If there's no host address, this is
2082 command-line SMTP input - check against an empty string for the address.
2085 listptr pointer to the host list
2087 Returns: the yield of verify_check_this_host(),
2088 i.e. OK, FAIL, or DEFER
2092 verify_check_host(uschar **listptr)
2094 return verify_check_this_host(listptr, sender_host_cache, NULL,
2095 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
2102 /*************************************************
2103 * Invert an IP address for a DNS black list *
2104 *************************************************/
2108 buffer where to put the answer
2109 address the address to invert
2113 invert_address(uschar *buffer, uschar *address)
2116 uschar *bptr = buffer;
2118 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
2119 to the IPv4 part only. */
2121 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
2123 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
2126 if (host_aton(address, bin) == 1)
2130 for (i = 0; i < 4; i++)
2132 sprintf(CS bptr, "%d.", x & 255);
2133 while (*bptr) bptr++;
2138 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
2139 in any DNS black lists, and the format in which they will be looked up is
2140 unknown. This is just a guess. */
2146 for (j = 3; j >= 0; j--)
2149 for (i = 0; i < 8; i++)
2151 sprintf(CS bptr, "%x.", x & 15);
2152 while (*bptr) bptr++;
2162 /*************************************************
2163 * Check host against DNS black lists *
2164 *************************************************/
2166 /* This function runs checks against a list of DNS black lists, until one
2167 matches. Each item on the list can be of the form
2169 domain=ip-address/key
2171 The domain is the right-most domain that is used for the query, for example,
2172 blackholes.mail-abuse.org. If the IP address is present, there is a match only
2173 if the DNS lookup returns a matching IP address. Several addresses may be
2174 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
2176 If no key is given, what is looked up in the domain is the inverted IP address
2177 of the current client host. If a key is given, it is used to construct the
2178 domain for the lookup. For example,
2180 dsn.rfc-ignorant.org/$sender_address_domain
2182 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
2183 then we check for a TXT record for an error message, and if found, save its
2184 value in $dnslist_text. We also cache everything in a tree, to optimize
2187 Note: an address for testing RBL is 192.203.178.39
2188 Note: an address for testing DUL is 192.203.178.4
2189 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
2192 listptr the domain/address/data list
2194 Returns: OK successful lookup (i.e. the address is on the list), or
2195 lookup deferred after +include_unknown
2196 FAIL name not found, or no data found for the given type, or
2197 lookup deferred after +exclude_unknown (default)
2198 DEFER lookup failure, if +defer_unknown was set
2202 verify_check_dnsbl(uschar **listptr)
2205 int defer_return = FAIL;
2206 int old_pool = store_pool;
2207 BOOL invert_result = FALSE;
2208 uschar *list = *listptr;
2211 uschar buffer[1024];
2212 uschar query[256]; /* DNS domain max length */
2213 uschar revadd[128]; /* Long enough for IPv6 address */
2215 /* Indicate that the inverted IP address is not yet set up */
2219 /* Loop through all the domains supplied, until something matches */
2221 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
2224 BOOL bitmask = FALSE;
2230 dnsbl_cache_block *cb;
2232 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
2234 /* Deal with special values that change the behaviour on defer */
2236 if (domain[0] == '+')
2238 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
2239 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
2240 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
2242 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
2247 /* See if there's explicit data to be looked up */
2249 key = Ustrchr(domain, '/');
2250 if (key != NULL) *key++ = 0;
2252 /* See if there's a list of addresses supplied after the domain name. This is
2253 introduced by an = or a & character; if preceded by ! we invert the result.
2256 iplist = Ustrchr(domain, '=');
2260 iplist = Ustrchr(domain, '&');
2265 if (iplist > domain && iplist[-1] == '!')
2267 invert_result = TRUE;
2273 /* Check that what we have left is a sensible domain name. There is no reason
2274 why these domains should in fact use the same syntax as hosts and email
2275 domains, but in practice they seem to. However, there is little point in
2276 actually causing an error here, because that would no doubt hold up incoming
2277 mail. Instead, I'll just log it. */
2279 for (s = domain; *s != 0; s++)
2281 if (!isalnum(*s) && *s != '-' && *s != '.')
2283 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
2284 "strange characters - is this right?", domain);
2289 /* Construct the query by adding the domain onto either the sending host
2290 address, or the given key string. */
2294 if (sender_host_address == NULL) return FAIL; /* can never match */
2295 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
2296 frc = string_format(query, sizeof(query), "%s%s", revadd, domain);
2300 frc = string_format(query, sizeof(query), "%s.%s", key, domain);
2305 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2306 "(ignored): %s...", query);
2310 /* Look for this query in the cache. */
2312 t = tree_search(dnsbl_cache, query);
2314 /* If not cached from a previous lookup, we must do a DNS lookup, and
2315 cache the result in permanent memory. */
2319 store_pool = POOL_PERM;
2321 /* In case this is the first time the DNS resolver is being used. */
2323 dns_init(FALSE, FALSE);
2325 /* Set up a tree entry to cache the lookup */
2327 t = store_get(sizeof(tree_node) + Ustrlen(query));
2328 Ustrcpy(t->name, query);
2329 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
2330 (void)tree_insertnode(&dnsbl_cache, t);
2332 /* Do the DNS loopup . */
2334 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
2335 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
2336 cb->text_set = FALSE;
2340 /* If the lookup succeeded, cache the RHS address. The code allows for
2341 more than one address - this was for complete generality and the possible
2342 use of A6 records. However, A6 records have been reduced to experimental
2343 status (August 2001) and may die out. So they may never get used at all,
2344 let alone in dnsbl records. However, leave the code here, just in case.
2346 Quite apart from one A6 RR generating multiple addresses, there are DNS
2347 lists that return more than one A record, so we must handle multiple
2348 addresses generated in that way as well. */
2350 if (cb->rc == DNS_SUCCEED)
2353 dns_address **addrp = &(cb->rhs);
2354 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2356 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2358 if (rr->type == T_A)
2360 dns_address *da = dns_address_from_rr(&dnsa, rr);
2364 while (da->next != NULL) da = da->next;
2365 addrp = &(da->next);
2370 /* If we didn't find any A records, change the return code. This can
2371 happen when there is a CNAME record but there are no A records for what
2374 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
2377 store_pool = old_pool;
2380 /* Previous lookup was cached */
2384 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
2388 /* We now have the result of the DNS lookup, either newly done, or cached
2389 from a previous call. If the lookup succeeded, check against the address
2390 list if there is one. This may be a positive equality list (introduced by
2391 "="), a negative equality list (introduced by "!="), a positive bitmask
2392 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
2394 if (cb->rc == DNS_SUCCEED)
2396 dns_address *da = NULL;
2397 uschar *addlist = cb->rhs->address;
2399 /* For A and AAAA records, there may be multiple addresses from multiple
2400 records. For A6 records (currently not expected to be used) there may be
2401 multiple addresses from a single record. */
2403 for (da = cb->rhs->next; da != NULL; da = da->next)
2404 addlist = string_sprintf("%s, %s", addlist, da->address);
2406 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
2409 /* Address list check; this can be either for equality, or via a bitmask.
2410 In the latter case, all the bits must match. */
2416 uschar *ptr = iplist;
2418 while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL)
2420 /* Handle exact matching */
2423 for (da = cb->rhs; da != NULL; da = da->next)
2425 if (Ustrcmp(CS da->address, ip) == 0) break;
2428 /* Handle bitmask matching */
2434 /* At present, all known DNS blocking lists use A records, with
2435 IPv4 addresses on the RHS encoding the information they return. I
2436 wonder if this will linger on as the last vestige of IPv4 when IPv6
2437 is ubiquitous? Anyway, for now we use paranoia code to completely
2438 ignore IPv6 addresses. The default mask is 0, which always matches.
2439 We change this only for IPv4 addresses in the list. */
2441 if (host_aton(ip, address) == 1) mask = address[0];
2443 /* Scan the returned addresses, skipping any that are IPv6 */
2445 for (da = cb->rhs; da != NULL; da = da->next)
2447 if (host_aton(da->address, address) != 1) continue;
2448 if ((address[0] & mask) == mask) break;
2452 /* Break out if a match has been found */
2454 if (da != NULL) break;
2459 (a) No IP address in a positive list matched, or
2460 (b) An IP address in a negative list did match
2462 then behave as if the DNSBL lookup had not succeeded, i.e. the host is
2465 if (invert_result != (da == NULL))
2469 debug_printf("=> but we are not accepting this block class because\n");
2470 debug_printf("=> there was %s match for %c%s\n",
2471 invert_result? "an exclude":"no", bitmask? '&' : '=', iplist);
2473 continue; /* With next DNSBL domain */
2477 /* Either there was no IP list, or the record matched. Look up a TXT record
2478 if it hasn't previously been done. */
2482 cb->text_set = TRUE;
2483 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
2486 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2488 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2489 if (rr->type == T_TXT) break;
2492 int len = (rr->data)[0];
2493 if (len > 511) len = 127;
2494 store_pool = POOL_PERM;
2495 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
2496 store_pool = old_pool;
2503 debug_printf("=> that means %s is listed at %s\n",
2504 (key == NULL)? sender_host_address : key, domain);
2507 dnslist_domain = string_copy(domain);
2508 dnslist_value = addlist;
2509 dnslist_text = cb->text;
2513 /* There was a problem with the DNS lookup */
2515 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
2517 log_write(L_dnslist_defer, LOG_MAIN,
2518 "DNS list lookup defer (probably timeout) for %s: %s", query,
2519 (defer_return == OK)? US"assumed in list" :
2520 (defer_return == FAIL)? US"assumed not in list" :
2521 US"returned DEFER");
2522 return defer_return;
2525 /* No entry was found in the DNS; continue for next domain */
2529 debug_printf("DNS lookup for %s failed\n", query);
2530 debug_printf("=> that means %s is not listed at %s\n",
2531 (key == NULL)? sender_host_address : key, domain);
2533 } /* Continue with next domain */
2538 /* End of verify.c */