Implement daemon_startup_{retries,sleep} to control startup retrying.
[exim.git] / src / src / verify.c
CommitLineData
90e9ce59 1/* $Cambridge: exim/src/src/verify.c,v 1.19 2005/06/17 10:20:30 ph10 Exp $ */
059ec3d9
PH
2
3/*************************************************
4* Exim - an Internet mail transport agent *
5*************************************************/
6
c988f1f4 7/* Copyright (c) University of Cambridge 1995 - 2005 */
059ec3d9
PH
8/* See the file NOTICE for conditions of use and distribution. */
9
10/* Functions concerned with verifying things. The original code for callout
11caching was contributed by Kevin Fleming (but I hacked it around a bit). */
12
13
14#include "exim.h"
15
16
17/* Structure for caching DNSBL lookups */
18
19typedef struct dnsbl_cache_block {
20 dns_address *rhs;
21 uschar *text;
22 int rc;
23 BOOL text_set;
24} dnsbl_cache_block;
25
26
27/* Anchor for DNSBL cache */
28
29static tree_node *dnsbl_cache = NULL;
30
31
32
33/*************************************************
34* Retrieve a callout cache record *
35*************************************************/
36
37/* If a record exists, check whether it has expired.
38
39Arguments:
40 dbm_file an open hints file
41 key the record key
42 type "address" or "domain"
43 positive_expire expire time for positive records
44 negative_expire expire time for negative records
45
46Returns: the cache record if a non-expired one exists, else NULL
47*/
48
49static dbdata_callout_cache *
50get_callout_cache_record(open_db *dbm_file, uschar *key, uschar *type,
51 int positive_expire, int negative_expire)
52{
53BOOL negative;
54int length, expire;
55time_t now;
56dbdata_callout_cache *cache_record;
57
58cache_record = dbfn_read_with_length(dbm_file, key, &length);
59
60if (cache_record == NULL)
61 {
62 HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type);
63 return NULL;
64 }
65
66/* We treat a record as "negative" if its result field is not positive, or if
67it is a domain record and the postmaster field is negative. */
68
69negative = cache_record->result != ccache_accept ||
70 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
71expire = negative? negative_expire : positive_expire;
72now = time(NULL);
73
74if (now - cache_record->time_stamp > expire)
75 {
76 HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type);
77 return NULL;
78 }
79
80/* If this is a non-reject domain record, check for the obsolete format version
81that doesn't have the postmaster and random timestamps, by looking at the
82length. If so, copy it to a new-style block, replicating the record's
83timestamp. Then check the additional timestamps. (There's no point wasting
84effort if connections are rejected.) */
85
86if (type[0] == 'd' && cache_record->result != ccache_reject)
87 {
88 if (length == sizeof(dbdata_callout_cache_obs))
89 {
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;
93 cache_record = new;
94 }
95
96 if (now - cache_record->postmaster_stamp > expire)
97 cache_record->postmaster_result = ccache_unknown;
98
99 if (now - cache_record->random_stamp > expire)
100 cache_record->random_result = ccache_unknown;
101 }
102
103HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type);
104return cache_record;
105}
106
107
108
109/*************************************************
110* Do callout verification for an address *
111*************************************************/
112
113/* This function is called from verify_address() when the address has routed to
114a host list, and a callout has been requested. Callouts are expensive; that is
115why a cache is used to improve the efficiency.
116
117Arguments:
118 addr the address that's been routed
119 host_list the list of hosts to try
120 tf the transport feedback block
121
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
4deaf07d
PH
126 callout_overall the overall callout timeout (if < 0 use 4*callout)
127 callout_connect the callout connection timeout (if < 0 use callout)
059ec3d9
PH
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
2a4be8f9 131 vopt_callout_fullpm => if postmaster check, do full one
059ec3d9
PH
132 vopt_callout_random => do the "random" thing
133 vopt_callout_recipsender => use real sender for recipient
134 vopt_callout_recippmaster => use postmaster for recipient
135 se_mailfrom MAIL FROM address for sender verify; NULL => ""
136 pm_mailfrom if non-NULL, do the postmaster check with this sender
137
138Returns: OK/FAIL/DEFER
139*/
140
141static int
142do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
8e669ac1 143 int callout, int callout_overall, int callout_connect, int options,
4deaf07d 144 uschar *se_mailfrom, uschar *pm_mailfrom)
059ec3d9
PH
145{
146BOOL is_recipient = (options & vopt_is_recipient) != 0;
147BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
148BOOL callout_random = (options & vopt_callout_random) != 0;
149
150int yield = OK;
151BOOL done = FALSE;
152uschar *address_key;
153uschar *from_address;
154uschar *random_local_part = NULL;
8e669ac1 155uschar **failure_ptr = is_recipient?
2c7db3f5 156 &recipient_verify_failure : &sender_verify_failure;
059ec3d9
PH
157open_db dbblock;
158open_db *dbm_file = NULL;
159dbdata_callout_cache new_domain_record;
160dbdata_callout_cache_address new_address_record;
161host_item *host;
162time_t callout_start_time;
163
164new_domain_record.result = ccache_unknown;
165new_domain_record.postmaster_result = ccache_unknown;
166new_domain_record.random_result = ccache_unknown;
167
168memset(&new_address_record, 0, sizeof(new_address_record));
169
170/* For a recipient callout, the key used for the address cache record must
171include the sender address if we are using the real sender in the callout,
172because that may influence the result of the callout. */
173
174address_key = addr->address;
175from_address = US"";
176
177if (is_recipient)
178 {
179 if ((options & vopt_callout_recipsender) != 0)
180 {
181 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
182 from_address = sender_address;
183 }
184 else if ((options & vopt_callout_recippmaster) != 0)
185 {
186 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
187 qualify_domain_sender);
188 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
189 }
190 }
191
192/* For a sender callout, we must adjust the key if the mailfrom address is not
193empty. */
194
195else
196 {
197 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
198 if (from_address[0] != 0)
199 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
200 }
201
202/* Open the callout cache database, it it exists, for reading only at this
203stage, unless caching has been disabled. */
204
205if (callout_no_cache)
206 {
207 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
208 }
209else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
210 {
211 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
212 }
213
214/* If a cache database is available see if we can avoid the need to do an
215actual callout by making use of previously-obtained data. */
216
217if (dbm_file != NULL)
218 {
219 dbdata_callout_cache_address *cache_address_record;
220 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
221 addr->domain, US"domain",
222 callout_cache_domain_positive_expire,
223 callout_cache_domain_negative_expire);
224
225 /* If an unexpired cache record was found for this domain, see if the callout
226 process can be short-circuited. */
227
228 if (cache_record != NULL)
229 {
230 /* If an early command (up to and including MAIL FROM:<>) was rejected,
231 there is no point carrying on. The callout fails. */
232
233 if (cache_record->result == ccache_reject)
234 {
235 setflag(addr, af_verify_nsfail);
236 HDEBUG(D_verify)
237 debug_printf("callout cache: domain gave initial rejection, or "
238 "does not accept HELO or MAIL FROM:<>\n");
239 setflag(addr, af_verify_nsfail);
240 addr->user_message = US"(result of an earlier callout reused).";
241 yield = FAIL;
8e669ac1 242 *failure_ptr = US"mail";
059ec3d9
PH
243 goto END_CALLOUT;
244 }
245
246 /* If a previous check on a "random" local part was accepted, we assume
247 that the server does not do any checking on local parts. There is therefore
248 no point in doing the callout, because it will always be successful. If a
249 random check previously failed, arrange not to do it again, but preserve
250 the data in the new record. If a random check is required but hasn't been
251 done, skip the remaining cache processing. */
252
253 if (callout_random) switch(cache_record->random_result)
254 {
255 case ccache_accept:
256 HDEBUG(D_verify)
257 debug_printf("callout cache: domain accepts random addresses\n");
258 goto END_CALLOUT; /* Default yield is OK */
259
260 case ccache_reject:
261 HDEBUG(D_verify)
262 debug_printf("callout cache: domain rejects random addresses\n");
263 callout_random = FALSE;
264 new_domain_record.random_result = ccache_reject;
265 new_domain_record.random_stamp = cache_record->random_stamp;
266 break;
267
268 default:
269 HDEBUG(D_verify)
270 debug_printf("callout cache: need to check random address handling "
271 "(not cached or cache expired)\n");
272 goto END_CACHE;
273 }
274
275 /* If a postmaster check is requested, but there was a previous failure,
276 there is again no point in carrying on. If a postmaster check is required,
277 but has not been done before, we are going to have to do a callout, so skip
278 remaining cache processing. */
279
280 if (pm_mailfrom != NULL)
281 {
282 if (cache_record->postmaster_result == ccache_reject)
283 {
284 setflag(addr, af_verify_pmfail);
285 HDEBUG(D_verify)
286 debug_printf("callout cache: domain does not accept "
287 "RCPT TO:<postmaster@domain>\n");
288 yield = FAIL;
8e669ac1 289 *failure_ptr = US"postmaster";
059ec3d9
PH
290 setflag(addr, af_verify_pmfail);
291 addr->user_message = US"(result of earlier verification reused).";
292 goto END_CALLOUT;
293 }
294 if (cache_record->postmaster_result == ccache_unknown)
295 {
296 HDEBUG(D_verify)
297 debug_printf("callout cache: need to check RCPT "
298 "TO:<postmaster@domain> (not cached or cache expired)\n");
299 goto END_CACHE;
300 }
301
302 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
303 postmaster check if the address itself has to be checked. Also ensure
304 that the value in the cache record is preserved (with its old timestamp).
305 */
306
307 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
308 "TO:<postmaster@domain>\n");
309 pm_mailfrom = NULL;
310 new_domain_record.postmaster_result = ccache_accept;
311 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
312 }
313 }
314
315 /* We can't give a result based on information about the domain. See if there
316 is an unexpired cache record for this specific address (combined with the
317 sender address if we are doing a recipient callout with a non-empty sender).
318 */
319
320 cache_address_record = (dbdata_callout_cache_address *)
321 get_callout_cache_record(dbm_file,
322 address_key, US"address",
323 callout_cache_positive_expire,
324 callout_cache_negative_expire);
325
326 if (cache_address_record != NULL)
327 {
328 if (cache_address_record->result == ccache_accept)
329 {
330 HDEBUG(D_verify)
331 debug_printf("callout cache: address record is positive\n");
332 }
333 else
334 {
335 HDEBUG(D_verify)
336 debug_printf("callout cache: address record is negative\n");
337 addr->user_message = US"Previous (cached) callout verification failure";
8e669ac1 338 *failure_ptr = US"recipient";
059ec3d9
PH
339 yield = FAIL;
340 }
341 goto END_CALLOUT;
342 }
343
344 /* Close the cache database while we actually do the callout for real. */
345
346 END_CACHE:
347 dbfn_close(dbm_file);
348 dbm_file = NULL;
349 }
350
351/* The information wasn't available in the cache, so we have to do a real
352callout and save the result in the cache for next time, unless no_cache is set,
353or unless we have a previously cached negative random result. If we are to test
354with a random local part, ensure that such a local part is available. If not,
355log the fact, but carry on without randomming. */
356
357if (callout_random && callout_random_local_part != NULL)
358 {
359 random_local_part = expand_string(callout_random_local_part);
360 if (random_local_part == NULL)
361 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
362 "callout_random_local_part: %s", expand_string_message);
363 }
364
4deaf07d
PH
365/* Default the connect and overall callout timeouts if not set, and record the
366time we are starting so that we can enforce it. */
059ec3d9
PH
367
368if (callout_overall < 0) callout_overall = 4 * callout;
4deaf07d 369if (callout_connect < 0) callout_connect = callout;
059ec3d9
PH
370callout_start_time = time(NULL);
371
372/* Now make connections to the hosts and do real callouts. The list of hosts
373is passed in as an argument. */
374
375for (host = host_list; host != NULL && !done; host = host->next)
376 {
377 smtp_inblock inblock;
378 smtp_outblock outblock;
379 int host_af;
380 int port = 25;
8e669ac1 381 BOOL send_quit = TRUE;
059ec3d9
PH
382 uschar *helo = US"HELO";
383 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
384 uschar inbuffer[4096];
385 uschar outbuffer[1024];
386 uschar responsebuffer[4096];
387
388 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
389 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
390
391 /* Skip this host if we don't have an IP address for it. */
392
393 if (host->address == NULL)
394 {
395 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
396 host->name);
397 continue;
398 }
399
400 /* Check the overall callout timeout */
401
402 if (time(NULL) - callout_start_time >= callout_overall)
403 {
404 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
405 break;
406 }
407
408 /* Set IPv4 or IPv6 */
409
410 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
411
412 /* Expand and interpret the interface and port strings. This has to
413 be delayed till now, because they may expand differently for different
414 hosts. If there's a failure, log it, but carry on with the defaults. */
415
416 deliver_host = host->name;
417 deliver_host_address = host->address;
418 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
419 US"callout") ||
420 !smtp_get_port(tf->port, addr, &port, US"callout"))
421 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
422 addr->message);
423 deliver_host = deliver_host_address = NULL;
424
425 /* Set HELO string according to the protocol */
426
427 if (Ustrcmp(tf->protocol, "lmtp") == 0) helo = US"LHLO";
428
429 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
430
431 /* Set up the buffer for reading SMTP response packets. */
432
433 inblock.buffer = inbuffer;
434 inblock.buffersize = sizeof(inbuffer);
435 inblock.ptr = inbuffer;
436 inblock.ptrend = inbuffer;
437
438 /* Set up the buffer for holding SMTP commands while pipelining */
439
440 outblock.buffer = outbuffer;
441 outblock.buffersize = sizeof(outbuffer);
442 outblock.ptr = outbuffer;
443 outblock.cmd_count = 0;
444 outblock.authenticating = FALSE;
445
446 /* Connect to the host; on failure, just loop for the next one, but we
4deaf07d 447 set the error for the last one. Use the callout_connect timeout. */
059ec3d9
PH
448
449 inblock.sock = outblock.sock =
4deaf07d 450 smtp_connect(host, host_af, port, interface, callout_connect, TRUE);
059ec3d9
PH
451 if (inblock.sock < 0)
452 {
453 addr->message = string_sprintf("could not connect to %s [%s]: %s",
454 host->name, host->address, strerror(errno));
455 continue;
456 }
457
458 /* Wait for initial response, and then run the initial SMTP commands. The
459 smtp_write_command() function leaves its command in big_buffer. This is
460 used in error responses. Initialize it in case the connection is
461 rejected. */
462
463 Ustrcpy(big_buffer, "initial connection");
464
465 done =
466 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
467 '2', callout) &&
468
469 smtp_write_command(&outblock, FALSE, "%s %s\r\n", helo,
470 smtp_active_hostname) >= 0 &&
471 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
472 '2', callout) &&
473
474 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
475 from_address) >= 0 &&
476 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
477 '2', callout);
478
479 /* If the host gave an initial error, or does not accept HELO or MAIL
480 FROM:<>, arrange to cache this information, but don't record anything for an
481 I/O error or a defer. Do not cache rejections when a non-empty sender has
482 been used, because that blocks the whole domain for all senders. */
483
484 if (!done)
485 {
8e669ac1 486 *failure_ptr = US"mail";
059ec3d9
PH
487 if (errno == 0 && responsebuffer[0] == '5')
488 {
489 setflag(addr, af_verify_nsfail);
490 if (from_address[0] == 0) new_domain_record.result = ccache_reject;
491 }
492 }
493
494 /* Otherwise, proceed to check a "random" address (if required), then the
495 given address, and the postmaster address (if required). Between each check,
496 issue RSET, because some servers accept only one recipient after MAIL
497 FROM:<>. */
498
499 else
500 {
501 new_domain_record.result = ccache_accept;
502
503 /* Do the random local part check first */
504
505 if (random_local_part != NULL)
506 {
507 uschar randombuffer[1024];
508 BOOL random_ok =
509 smtp_write_command(&outblock, FALSE,
510 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
511 addr->domain) >= 0 &&
512 smtp_read_response(&inblock, randombuffer,
513 sizeof(randombuffer), '2', callout);
514
515 /* Remember when we last did a random test */
516
517 new_domain_record.random_stamp = time(NULL);
518
519 /* If accepted, we aren't going to do any further tests below. */
520
521 if (random_ok)
522 {
523 new_domain_record.random_result = ccache_accept;
524 }
525
526 /* Otherwise, cache a real negative response, and get back to the right
527 state to send RCPT. Unless there's some problem such as a dropped
528 connection, we expect to succeed, because the commands succeeded above. */
529
530 else if (errno == 0)
531 {
532 if (randombuffer[0] == '5')
533 new_domain_record.random_result = ccache_reject;
534
535 done =
536 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
537 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
538 '2', callout) &&
539
90e9ce59
PH
540 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
541 from_address) >= 0 &&
059ec3d9
PH
542 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
543 '2', callout);
544 }
545 else done = FALSE; /* Some timeout/connection problem */
546 } /* Random check */
547
548 /* If the host is accepting all local parts, as determined by the "random"
549 check, we don't need to waste time doing any further checking. */
550
551 if (new_domain_record.random_result != ccache_accept && done)
552 {
553 done =
554 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
c688b954
PH
555 transport_rcpt_address(addr,
556 addr->transport->rcpt_include_affixes)) >= 0 &&
059ec3d9
PH
557 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
558 '2', callout);
559
560 if (done)
561 new_address_record.result = ccache_accept;
562 else if (errno == 0 && responsebuffer[0] == '5')
2c7db3f5 563 {
8e669ac1 564 *failure_ptr = US"recipient";
059ec3d9 565 new_address_record.result = ccache_reject;
8e669ac1 566 }
059ec3d9 567
2a4be8f9
PH
568 /* Do postmaster check if requested; if a full check is required, we
569 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
059ec3d9
PH
570
571 if (done && pm_mailfrom != NULL)
572 {
573 done =
574 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
575 smtp_read_response(&inblock, responsebuffer,
576 sizeof(responsebuffer), '2', callout) &&
577
578 smtp_write_command(&outblock, FALSE,
579 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
580 smtp_read_response(&inblock, responsebuffer,
581 sizeof(responsebuffer), '2', callout) &&
582
2a4be8f9
PH
583 /* First try using the current domain */
584
585 ((
059ec3d9
PH
586 smtp_write_command(&outblock, FALSE,
587 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
588 smtp_read_response(&inblock, responsebuffer,
2a4be8f9
PH
589 sizeof(responsebuffer), '2', callout)
590 )
591
592 ||
593
594 /* If that doesn't work, and a full check is requested,
595 try without the domain. */
596
597 (
598 (options & vopt_callout_fullpm) != 0 &&
599 smtp_write_command(&outblock, FALSE,
600 "RCPT TO:<postmaster>\r\n") >= 0 &&
601 smtp_read_response(&inblock, responsebuffer,
602 sizeof(responsebuffer), '2', callout)
603 ));
604
605 /* Sort out the cache record */
059ec3d9
PH
606
607 new_domain_record.postmaster_stamp = time(NULL);
608
609 if (done)
610 new_domain_record.postmaster_result = ccache_accept;
611 else if (errno == 0 && responsebuffer[0] == '5')
612 {
8e669ac1 613 *failure_ptr = US"postmaster";
059ec3d9
PH
614 setflag(addr, af_verify_pmfail);
615 new_domain_record.postmaster_result = ccache_reject;
616 }
617 }
618 } /* Random not accepted */
90e9ce59 619 } /* MAIL FROM: accepted */
059ec3d9
PH
620
621 /* For any failure of the main check, other than a negative response, we just
622 close the connection and carry on. We can identify a negative response by the
623 fact that errno is zero. For I/O errors it will be non-zero
624
625 Set up different error texts for logging and for sending back to the caller
626 as an SMTP response. Log in all cases, using a one-line format. For sender
627 callouts, give a full response to the caller, but for recipient callouts,
628 don't give the IP address because this may be an internal host whose identity
629 is not to be widely broadcast. */
630
631 if (!done)
632 {
633 if (errno == ETIMEDOUT)
634 {
635 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
8e669ac1 636 send_quit = FALSE;
059ec3d9
PH
637 }
638 else if (errno == 0)
639 {
640 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
641
642 addr->message =
643 string_sprintf("response to \"%s\" from %s [%s] was: %s",
644 big_buffer, host->name, host->address,
645 string_printing(responsebuffer));
646
647 addr->user_message = is_recipient?
648 string_sprintf("Callout verification failed:\n%s", responsebuffer)
649 :
650 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
651 host->address, big_buffer, responsebuffer);
652
653 /* Hard rejection ends the process */
654
655 if (responsebuffer[0] == '5') /* Address rejected */
656 {
657 yield = FAIL;
658 done = TRUE;
659 }
660 }
661 }
662
663 /* End the SMTP conversation and close the connection. */
664
c9bdd01c 665 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
059ec3d9
PH
666 close(inblock.sock);
667 } /* Loop through all hosts, while !done */
668
669/* If we get here with done == TRUE, a successful callout happened, and yield
670will be set OK or FAIL according to the response to the RCPT command.
671Otherwise, we looped through the hosts but couldn't complete the business.
672However, there may be domain-specific information to cache in both cases.
673
674The value of the result field in the new_domain record is ccache_unknown if
90e9ce59 675there was an error before or with MAIL FROM:, and errno was not zero,
059ec3d9
PH
676implying some kind of I/O error. We don't want to write the cache in that case.
677Otherwise the value is ccache_accept or ccache_reject. */
678
679if (!callout_no_cache && new_domain_record.result != ccache_unknown)
680 {
681 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
682 == NULL)
683 {
684 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
685 }
686 else
687 {
688 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
689 (int)sizeof(dbdata_callout_cache));
690 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
691 " result=%d postmaster=%d random=%d\n",
692 new_domain_record.result,
693 new_domain_record.postmaster_result,
694 new_domain_record.random_result);
695 }
696 }
697
698/* If a definite result was obtained for the callout, cache it unless caching
699is disabled. */
700
701if (done)
702 {
703 if (!callout_no_cache && new_address_record.result != ccache_unknown)
704 {
705 if (dbm_file == NULL)
706 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
707 if (dbm_file == NULL)
708 {
709 HDEBUG(D_verify) debug_printf("no callout cache available\n");
710 }
711 else
712 {
713 (void)dbfn_write(dbm_file, address_key, &new_address_record,
714 (int)sizeof(dbdata_callout_cache_address));
715 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
716 (new_address_record.result == ccache_accept)? "positive" : "negative");
717 }
718 }
719 } /* done */
720
721/* Failure to connect to any host, or any response other than 2xx or 5xx is a
722temporary error. If there was only one host, and a response was received, leave
723it alone if supplying details. Otherwise, give a generic response. */
724
725else /* !done */
726 {
727 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
728 is_recipient? "recipient" : "sender");
729 yield = DEFER;
730
731 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
732
733 addr->user_message = (!smtp_return_error_details)? dullmsg :
734 string_sprintf("%s for <%s>.\n"
735 "The mail server(s) for the domain may be temporarily unreachable, or\n"
736 "they may be permanently unreachable from this server. In the latter case,\n%s",
737 dullmsg, addr->address,
738 is_recipient?
739 "the address will never be accepted."
740 :
741 "you need to change the address or create an MX record for its domain\n"
742 "if it is supposed to be generally accessible from the Internet.\n"
743 "Talk to your mail administrator for details.");
744
745 /* Force a specific error code */
746
747 addr->basic_errno = ERRNO_CALLOUTDEFER;
748 }
749
750/* Come here from within the cache-reading code on fast-track exit. */
751
752END_CALLOUT:
753if (dbm_file != NULL) dbfn_close(dbm_file);
754return yield;
755}
756
757
758
759/*************************************************
760* Copy error to toplevel address *
761*************************************************/
762
763/* This function is used when a verify fails or defers, to ensure that the
764failure or defer information is in the original toplevel address. This applies
765when an address is redirected to a single new address, and the failure or
766deferral happens to the child address.
767
768Arguments:
769 vaddr the verify address item
770 addr the final address item
771 yield FAIL or DEFER
772
773Returns: the value of YIELD
774*/
775
776static int
777copy_error(address_item *vaddr, address_item *addr, int yield)
778{
779if (addr != vaddr)
780 {
781 vaddr->message = addr->message;
782 vaddr->user_message = addr->user_message;
783 vaddr->basic_errno = addr->basic_errno;
784 vaddr->more_errno = addr->more_errno;
785 }
786return yield;
787}
788
789
790
791
792/*************************************************
793* Verify an email address *
794*************************************************/
795
796/* This function is used both for verification (-bv and at other times) and
797address testing (-bt), which is indicated by address_test_mode being set.
798
799Arguments:
800 vaddr contains the address to verify; the next field in this block
801 must be NULL
802 f if not NULL, write the result to this file
803 options various option bits:
804 vopt_fake_sender => this sender verify is not for the real
805 sender (it was verify=sender=xxxx or an address from a
806 header line) - rewriting must not change sender_address
807 vopt_is_recipient => this is a recipient address, otherwise
808 it's a sender address - this affects qualification and
809 rewriting and messages from callouts
810 vopt_qualify => qualify an unqualified address; else error
811 vopt_expn => called from SMTP EXPN command
812
813 These ones are used by do_callout() -- the options variable
814 is passed to it.
815
2a4be8f9 816 vopt_callout_fullpm => if postmaster check, do full one
059ec3d9
PH
817 vopt_callout_no_cache => don't use callout cache
818 vopt_callout_random => do the "random" thing
819 vopt_callout_recipsender => use real sender for recipient
820 vopt_callout_recippmaster => use postmaster for recipient
821
822 callout if > 0, specifies that callout is required, and gives timeout
4deaf07d 823 for individual commands
059ec3d9
PH
824 callout_overall if > 0, gives overall timeout for the callout function;
825 if < 0, a default is used (see do_callout())
8e669ac1 826 callout_connect the connection timeout for callouts
059ec3d9
PH
827 se_mailfrom when callout is requested to verify a sender, use this
828 in MAIL FROM; NULL => ""
829 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
830 thing and use this as the sender address (may be "")
831
832 routed if not NULL, set TRUE if routing succeeded, so we can
833 distinguish between routing failed and callout failed
834
835Returns: OK address verified
836 FAIL address failed to verify
837 DEFER can't tell at present
838*/
839
840int
841verify_address(address_item *vaddr, FILE *f, int options, int callout,
8e669ac1 842 int callout_overall, int callout_connect, uschar *se_mailfrom,
4deaf07d 843 uschar *pm_mailfrom, BOOL *routed)
059ec3d9
PH
844{
845BOOL allok = TRUE;
846BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
847BOOL is_recipient = (options & vopt_is_recipient) != 0;
848BOOL expn = (options & vopt_expn) != 0;
059ec3d9
PH
849int i;
850int yield = OK;
851int verify_type = expn? v_expn :
852 address_test_mode? v_none :
853 is_recipient? v_recipient : v_sender;
854address_item *addr_list;
855address_item *addr_new = NULL;
856address_item *addr_remote = NULL;
857address_item *addr_local = NULL;
858address_item *addr_succeed = NULL;
8e669ac1 859uschar **failure_ptr = is_recipient?
2c7db3f5 860 &recipient_verify_failure : &sender_verify_failure;
059ec3d9
PH
861uschar *ko_prefix, *cr;
862uschar *address = vaddr->address;
863uschar *save_sender;
864uschar null_sender[] = { 0 }; /* Ensure writeable memory */
865
2c7db3f5
PH
866/* Clear, just in case */
867
868*failure_ptr = NULL;
869
059ec3d9
PH
870/* Set up a prefix and suffix for error message which allow us to use the same
871output statements both in EXPN mode (where an SMTP response is needed) and when
872debugging with an output file. */
873
874if (expn)
875 {
876 ko_prefix = US"553 ";
877 cr = US"\r";
878 }
879else ko_prefix = cr = US"";
880
881/* Add qualify domain if permitted; otherwise an unqualified address fails. */
882
883if (parse_find_at(address) == NULL)
884 {
885 if ((options & vopt_qualify) == 0)
886 {
887 if (f != NULL)
888 fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address,
889 cr);
8e669ac1 890 *failure_ptr = US"qualify";
059ec3d9
PH
891 return FAIL;
892 }
893 address = rewrite_address_qualify(address, is_recipient);
894 }
895
896DEBUG(D_verify)
897 {
898 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
899 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
900 }
901
902/* Rewrite and report on it. Clear the domain and local part caches - these
903may have been set by domains and local part tests during an ACL. */
904
905if (global_rewrite_rules != NULL)
906 {
907 uschar *old = address;
908 address = rewrite_address(address, is_recipient, FALSE,
909 global_rewrite_rules, rewrite_existflags);
910 if (address != old)
911 {
912 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
913 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
914 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
915 }
916 }
917
918/* If this is the real sender address, we must update sender_address at
919this point, because it may be referred to in the routers. */
920
921if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
922 sender_address = address;
923
924/* If the address was rewritten to <> no verification can be done, and we have
925to return OK. This rewriting is permitted only for sender addresses; for other
926addresses, such rewriting fails. */
927
928if (address[0] == 0) return OK;
929
930/* Save a copy of the sender address for re-instating if we change it to <>
931while verifying a sender address (a nice bit of self-reference there). */
932
933save_sender = sender_address;
934
935/* Update the address structure with the possibly qualified and rewritten
936address. Set it up as the starting address on the chain of new addresses. */
937
938vaddr->address = address;
939addr_new = vaddr;
940
941/* We need a loop, because an address can generate new addresses. We must also
942cope with generated pipes and files at the top level. (See also the code and
943comment in deliver.c.) However, it is usually the case that the router for
944user's .forward files has its verify flag turned off.
945
946If an address generates more than one child, the loop is used only when
947full_info is set, and this can only be set locally. Remote enquiries just get
948information about the top level address, not anything that it generated. */
949
950while (addr_new != NULL)
951 {
952 int rc;
953 address_item *addr = addr_new;
954
955 addr_new = addr->next;
956 addr->next = NULL;
957
958 DEBUG(D_verify)
959 {
960 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
961 debug_printf("Considering %s\n", addr->address);
962 }
963
964 /* Handle generated pipe, file or reply addresses. We don't get these
965 when handling EXPN, as it does only one level of expansion. */
966
967 if (testflag(addr, af_pfr))
968 {
969 allok = FALSE;
970 if (f != NULL)
971 {
972 BOOL allow;
973
974 if (addr->address[0] == '>')
975 {
976 allow = testflag(addr, af_allow_reply);
977 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
978 }
979 else
980 {
981 allow = (addr->address[0] == '|')?
982 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
983 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
984 }
985
986 if (addr->basic_errno == ERRNO_BADTRANSPORT)
987 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
988 "%s\n", addr->message);
989 else if (allow)
990 fprintf(f, "\n transport = %s\n", addr->transport->name);
991 else
992 fprintf(f, " *** forbidden ***\n");
993 }
994 continue;
995 }
996
997 /* Just in case some router parameter refers to it. */
998
999 return_path = (addr->p.errors_address != NULL)?
1000 addr->p.errors_address : sender_address;
1001
1002 /* Split the address into domain and local part, handling the %-hack if
1003 necessary, and then route it. While routing a sender address, set
1004 $sender_address to <> because that is what it will be if we were trying to
1005 send a bounce to the sender. */
1006
1007 if (routed != NULL) *routed = FALSE;
1008 if ((rc = deliver_split_address(addr)) == OK)
1009 {
1010 if (!is_recipient) sender_address = null_sender;
1011 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1012 &addr_succeed, verify_type);
1013 sender_address = save_sender; /* Put back the real sender */
1014 }
1015
1016 /* If routing an address succeeded, set the flag that remembers, for use when
1017 an ACL cached a sender verify (in case a callout fails). Then if routing set
1018 up a list of hosts or the transport has a host list, and the callout option
1019 is set, and we aren't in a host checking run, do the callout verification,
1020 and set another flag that notes that a callout happened. */
1021
1022 if (rc == OK)
1023 {
1024 if (routed != NULL) *routed = TRUE;
1025 if (callout > 0)
1026 {
1027 host_item *host_list = addr->host_list;
1028
1029 /* Default, if no remote transport, to NULL for the interface (=> any),
1030 "smtp" for the port, and "smtp" for the protocol. */
1031
1032 transport_feedback tf = { NULL, US"smtp", US"smtp", NULL, FALSE, FALSE };
1033
1034 /* If verification yielded a remote transport, we want to use that
1035 transport's options, so as to mimic what would happen if we were really
1036 sending a message to this address. */
1037
1038 if (addr->transport != NULL && !addr->transport->info->local)
1039 {
1040 (void)(addr->transport->setup)(addr->transport, addr, &tf, NULL);
1041
1042 /* If the transport has hosts and the router does not, or if the
1043 transport is configured to override the router's hosts, we must build a
1044 host list of the transport's hosts, and find the IP addresses */
1045
1046 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1047 {
1048 uschar *s;
1049
1050 host_list = NULL; /* Ignore the router's hosts */
1051
1052 deliver_domain = addr->domain;
1053 deliver_localpart = addr->local_part;
1054 s = expand_string(tf.hosts);
1055 deliver_domain = deliver_localpart = NULL;
1056
1057 if (s == NULL)
1058 {
1059 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1060 "\"%s\" in %s transport for callout: %s", tf.hosts,
1061 addr->transport->name, expand_string_message);
1062 }
1063 else
1064 {
1065 uschar *canonical_name;
d8ef3577 1066 host_item *host, *nexthost;
059ec3d9
PH
1067 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1068
1069 /* Just ignore failures to find a host address. If we don't manage
8e669ac1
PH
1070 to find any addresses, the callout will defer. Note that more than
1071 one address may be found for a single host, which will result in
1072 additional host items being inserted into the chain. Hence we must
d8ef3577 1073 save the next host first. */
059ec3d9 1074
d8ef3577 1075 for (host = host_list; host != NULL; host = nexthost)
059ec3d9 1076 {
d8ef3577 1077 nexthost = host->next;
8e669ac1 1078 if (tf.gethostbyname ||
a5a28604 1079 string_is_ip_address(host->name, NULL) > 0)
059ec3d9
PH
1080 (void)host_find_byname(host, NULL, &canonical_name, TRUE);
1081 else
1082 {
1083 int flags = HOST_FIND_BY_A;
1084 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1085 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1086 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1087 &canonical_name, NULL);
1088 }
1089 }
1090 }
1091 }
1092 }
1093
8e669ac1 1094 /* Can only do a callout if we have at least one host! If the callout
2c7db3f5 1095 fails, it will have set ${sender,recipient}_verify_failure. */
059ec3d9
PH
1096
1097 if (host_list != NULL)
1098 {
1099 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1100 if (host_checking && !host_checking_callout)
1101 {
1102 HDEBUG(D_verify)
1103 debug_printf("... callout omitted by default when host testing\n"
1104 "(Use -bhc if you want the callouts to happen.)\n");
1105 }
1106 else
1107 {
1108 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
4deaf07d 1109 callout_connect, options, se_mailfrom, pm_mailfrom);
059ec3d9
PH
1110 }
1111 }
1112 else
1113 {
1114 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1115 "transport provided a host list\n");
1116 }
1117 }
1118 }
8e669ac1 1119
2c7db3f5 1120 /* Otherwise, any failure is a routing failure */
8e669ac1
PH
1121
1122 else *failure_ptr = US"route";
059ec3d9
PH
1123
1124 /* A router may return REROUTED if it has set up a child address as a result
1125 of a change of domain name (typically from widening). In this case we always
1126 want to continue to verify the new child. */
1127
1128 if (rc == REROUTED) continue;
8e669ac1 1129
059ec3d9
PH
1130 /* Handle hard failures */
1131
1132 if (rc == FAIL)
1133 {
1134 allok = FALSE;
1135 if (f != NULL)
1136 {
1137 fprintf(f, "%s%s %s", ko_prefix, address,
1138 address_test_mode? "is undeliverable" : "failed to verify");
1139 if (!expn && admin_user)
1140 {
1141 if (addr->basic_errno > 0)
1142 fprintf(f, ": %s", strerror(addr->basic_errno));
1143 if (addr->message != NULL)
1144 fprintf(f, ":\n %s", addr->message);
1145 }
1146 fprintf(f, "%s\n", cr);
1147 }
1148
1149 if (!full_info) return copy_error(vaddr, addr, FAIL);
1150 else yield = FAIL;
1151 }
1152
1153 /* Soft failure */
1154
1155 else if (rc == DEFER)
1156 {
1157 allok = FALSE;
1158 if (f != NULL)
1159 {
1160 fprintf(f, "%s%s cannot be resolved at this time", ko_prefix, address);
1161 if (!expn && admin_user)
1162 {
1163 if (addr->basic_errno > 0)
1164 fprintf(f, ":\n %s", strerror(addr->basic_errno));
1165 if (addr->message != NULL)
1166 fprintf(f, ":\n %s", addr->message);
1167 else if (addr->basic_errno <= 0)
1168 fprintf(f, ":\n unknown error");
1169 }
1170
1171 fprintf(f, "%s\n", cr);
1172 }
1173 if (!full_info) return copy_error(vaddr, addr, DEFER);
1174 else if (yield == OK) yield = DEFER;
1175 }
1176
1177 /* If we are handling EXPN, we do not want to continue to route beyond
1178 the top level. */
1179
1180 else if (expn)
1181 {
1182 uschar *ok_prefix = US"250-";
1183 if (addr_new == NULL)
1184 {
1185 if (addr_local == NULL && addr_remote == NULL)
1186 fprintf(f, "250 mail to <%s> is discarded\r\n", address);
1187 else
1188 fprintf(f, "250 <%s>\r\n", address);
1189 }
1190 else while (addr_new != NULL)
1191 {
1192 address_item *addr2 = addr_new;
1193 addr_new = addr2->next;
1194 if (addr_new == NULL) ok_prefix = US"250 ";
1195 fprintf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1196 }
1197 return OK;
1198 }
1199
1200 /* Successful routing other than EXPN. */
1201
1202 else
1203 {
1204 /* Handle successful routing when short info wanted. Otherwise continue for
1205 other (generated) addresses. Short info is the operational case. Full info
1206 can be requested only when debug_selector != 0 and a file is supplied.
1207
1208 There is a conflict between the use of aliasing as an alternate email
1209 address, and as a sort of mailing list. If an alias turns the incoming
1210 address into just one address (e.g. J.Caesar->jc44) you may well want to
1211 carry on verifying the generated address to ensure it is valid when
1212 checking incoming mail. If aliasing generates multiple addresses, you
1213 probably don't want to do this. Exim therefore treats the generation of
1214 just a single new address as a special case, and continues on to verify the
1215 generated address. */
1216
1217 if (!full_info && /* Stop if short info wanted AND */
1218 (addr_new == NULL || /* No new address OR */
1219 addr_new->next != NULL || /* More than one new address OR */
1220 testflag(addr_new, af_pfr))) /* New address is pfr */
1221 {
1222 if (f != NULL) fprintf(f, "%s %s\n", address,
1223 address_test_mode? "is deliverable" : "verified");
1224
1225 /* If we have carried on to verify a child address, we want the value
1226 of $address_data to be that of the child */
1227
1228 vaddr->p.address_data = addr->p.address_data;
1229 return OK;
1230 }
1231 }
1232 } /* Loop for generated addresses */
1233
1234/* Display the full results of the successful routing, including any generated
1235addresses. Control gets here only when full_info is set, which requires f not
1236to be NULL, and this occurs only when a top-level verify is called with the
1237debugging switch on.
1238
1239If there are no local and no remote addresses, and there were no pipes, files,
1240or autoreplies, and there were no errors or deferments, the message is to be
1241discarded, usually because of the use of :blackhole: in an alias file. */
1242
1243if (allok && addr_local == NULL && addr_remote == NULL)
1244 fprintf(f, "mail to %s is discarded\n", address);
1245
1246else for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1247 {
1248 while (addr_list != NULL)
1249 {
1250 address_item *addr = addr_list;
1251 address_item *p = addr->parent;
1252 addr_list = addr->next;
1253
1254 fprintf(f, "%s", CS addr->address);
384152a6
TK
1255#ifdef EXPERIMENTAL_SRS
1256 if(addr->p.srs_sender)
1257 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1258#endif
059ec3d9
PH
1259 while (p != NULL)
1260 {
1261 fprintf(f, "\n <-- %s", p->address);
1262 p = p->parent;
1263 }
1264 fprintf(f, "\n ");
1265
1266 /* Show router, and transport */
1267
1268 fprintf(f, "router = %s, ", addr->router->name);
1269 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1270 addr->transport->name);
1271
1272 /* Show any hosts that are set up by a router unless the transport
1273 is going to override them; fiddle a bit to get a nice format. */
1274
1275 if (addr->host_list != NULL && addr->transport != NULL &&
1276 !addr->transport->overrides_hosts)
1277 {
1278 host_item *h;
1279 int maxlen = 0;
1280 int maxaddlen = 0;
1281 for (h = addr->host_list; h != NULL; h = h->next)
1282 {
1283 int len = Ustrlen(h->name);
1284 if (len > maxlen) maxlen = len;
1285 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1286 if (len > maxaddlen) maxaddlen = len;
1287 }
1288 for (h = addr->host_list; h != NULL; h = h->next)
1289 {
1290 int len = Ustrlen(h->name);
1291 fprintf(f, " host %s ", h->name);
1292 while (len++ < maxlen) fprintf(f, " ");
1293 if (h->address != NULL)
1294 {
1295 fprintf(f, "[%s] ", h->address);
1296 len = Ustrlen(h->address);
1297 }
1298 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1299 {
1300 fprintf(f, "[unknown] ");
1301 len = 7;
1302 }
1303 else len = -3;
1304 while (len++ < maxaddlen) fprintf(f," ");
1305 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1306 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1307 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1308 fprintf(f, "\n");
1309 }
1310 }
1311 }
1312 }
1313
8e669ac1 1314/* Will be DEFER or FAIL if any one address has, only for full_info (which is
2c7db3f5
PH
1315the -bv or -bt case). */
1316
8e669ac1 1317return yield;
059ec3d9
PH
1318}
1319
1320
1321
1322
1323/*************************************************
1324* Check headers for syntax errors *
1325*************************************************/
1326
1327/* This function checks those header lines that contain addresses, and verifies
1328that all the addresses therein are syntactially correct.
1329
1330Arguments:
1331 msgptr where to put an error message
1332
1333Returns: OK
1334 FAIL
1335*/
1336
1337int
1338verify_check_headers(uschar **msgptr)
1339{
1340header_line *h;
1341uschar *colon, *s;
1342
1343for (h = header_list; h != NULL; h = h->next)
1344 {
1345 if (h->type != htype_from &&
1346 h->type != htype_reply_to &&
1347 h->type != htype_sender &&
1348 h->type != htype_to &&
1349 h->type != htype_cc &&
1350 h->type != htype_bcc)
1351 continue;
1352
1353 colon = Ustrchr(h->text, ':');
1354 s = colon + 1;
1355 while (isspace(*s)) s++;
1356
1357 parse_allow_group = TRUE; /* Allow group syntax */
1358
1359 /* Loop for multiple addresses in the header */
1360
1361 while (*s != 0)
1362 {
1363 uschar *ss = parse_find_address_end(s, FALSE);
1364 uschar *recipient, *errmess;
1365 int terminator = *ss;
1366 int start, end, domain;
1367
1368 /* Temporarily terminate the string at this point, and extract the
1369 operative address within. */
1370
1371 *ss = 0;
1372 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
1373 *ss = terminator;
1374
1375 /* Permit an unqualified address only if the message is local, or if the
1376 sending host is configured to be permitted to send them. */
1377
1378 if (recipient != NULL && domain == 0)
1379 {
1380 if (h->type == htype_from || h->type == htype_sender)
1381 {
1382 if (!allow_unqualified_sender) recipient = NULL;
1383 }
1384 else
1385 {
1386 if (!allow_unqualified_recipient) recipient = NULL;
1387 }
1388 if (recipient == NULL) errmess = US"unqualified address not permitted";
1389 }
1390
1391 /* It's an error if no address could be extracted, except for the special
1392 case of an empty address. */
1393
1394 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
1395 {
1396 uschar *verb = US"is";
1397 uschar *t = ss;
1398 int len;
1399
1400 /* Arrange not to include any white space at the end in the
1401 error message. */
1402
1403 while (t > s && isspace(t[-1])) t--;
1404
1405 /* Add the address which failed to the error message, since in a
1406 header with very many addresses it is sometimes hard to spot
1407 which one is at fault. However, limit the amount of address to
1408 quote - cases have been seen where, for example, a missing double
1409 quote in a humungous To: header creates an "address" that is longer
1410 than string_sprintf can handle. */
1411
1412 len = t - s;
1413 if (len > 1024)
1414 {
1415 len = 1024;
1416 verb = US"begins";
1417 }
1418
1419 *msgptr = string_printing(
1420 string_sprintf("%s: failing address in \"%.*s\" header %s: %.*s",
1421 errmess, colon - h->text, h->text, verb, len, s));
1422
1423 return FAIL;
1424 }
1425
1426 /* Advance to the next address */
1427
1428 s = ss + (terminator? 1:0);
1429 while (isspace(*s)) s++;
1430 } /* Next address */
1431 } /* Next header */
1432
1433return OK;
1434}
1435
1436
1437
1438
1439/*************************************************
1440* Find if verified sender *
1441*************************************************/
1442
1443/* Usually, just a single address is verified as the sender of the message.
1444However, Exim can be made to verify other addresses as well (often related in
1445some way), and this is useful in some environments. There may therefore be a
1446chain of such addresses that have previously been tested. This function finds
1447whether a given address is on the chain.
1448
1449Arguments: the address to be verified
1450Returns: pointer to an address item, or NULL
1451*/
1452
1453address_item *
1454verify_checked_sender(uschar *sender)
1455{
1456address_item *addr;
1457for (addr = sender_verified_list; addr != NULL; addr = addr->next)
1458 if (Ustrcmp(sender, addr->address) == 0) break;
1459return addr;
1460}
1461
1462
1463
1464
1465
1466/*************************************************
1467* Get valid header address *
1468*************************************************/
1469
1470/* Scan the originator headers of the message, looking for an address that
1471verifies successfully. RFC 822 says:
1472
1473 o The "Sender" field mailbox should be sent notices of
1474 any problems in transport or delivery of the original
1475 messages. If there is no "Sender" field, then the
1476 "From" field mailbox should be used.
1477
1478 o If the "Reply-To" field exists, then the reply should
1479 go to the addresses indicated in that field and not to
1480 the address(es) indicated in the "From" field.
1481
1482So we check a Sender field if there is one, else a Reply_to field, else a From
1483field. As some strange messages may have more than one of these fields,
1484especially if they are resent- fields, check all of them if there is more than
1485one.
1486
1487Arguments:
1488 user_msgptr points to where to put a user error message
1489 log_msgptr points to where to put a log error message
1490 callout timeout for callout check (passed to verify_address())
1491 callout_overall overall callout timeout (ditto)
8e669ac1 1492 callout_connect connect callout timeout (ditto)
059ec3d9
PH
1493 se_mailfrom mailfrom for verify; NULL => ""
1494 pm_mailfrom sender for pm callout check (passed to verify_address())
1495 options callout options (passed to verify_address())
8e669ac1 1496 verrno where to put the address basic_errno
059ec3d9
PH
1497
1498If log_msgptr is set to something without setting user_msgptr, the caller
1499normally uses log_msgptr for both things.
1500
1501Returns: result of the verification attempt: OK, FAIL, or DEFER;
1502 FAIL is given if no appropriate headers are found
1503*/
1504
1505int
1506verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
8e669ac1 1507 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
fe5b5d0b 1508 uschar *pm_mailfrom, int options, int *verrno)
059ec3d9
PH
1509{
1510static int header_types[] = { htype_sender, htype_reply_to, htype_from };
1511int yield = FAIL;
1512int i;
1513
1514for (i = 0; i < 3; i++)
1515 {
1516 header_line *h;
1517 for (h = header_list; h != NULL; h = h->next)
1518 {
1519 int terminator, new_ok;
1520 uschar *s, *ss, *endname;
1521
1522 if (h->type != header_types[i]) continue;
1523 s = endname = Ustrchr(h->text, ':') + 1;
1524
1525 while (*s != 0)
1526 {
1527 address_item *vaddr;
1528
1529 while (isspace(*s) || *s == ',') s++;
1530 if (*s == 0) break; /* End of header */
1531
1532 ss = parse_find_address_end(s, FALSE);
1533
1534 /* The terminator is a comma or end of header, but there may be white
1535 space preceding it (including newline for the last address). Move back
1536 past any white space so we can check against any cached envelope sender
1537 address verifications. */
1538
1539 while (isspace(ss[-1])) ss--;
1540 terminator = *ss;
1541 *ss = 0;
1542
1543 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
1544 (int)(endname - h->text), h->text, s);
1545
1546 /* See if we have already verified this address as an envelope sender,
1547 and if so, use the previous answer. */
1548
1549 vaddr = verify_checked_sender(s);
1550
1551 if (vaddr != NULL && /* Previously checked */
1552 (callout <= 0 || /* No callout needed; OR */
1553 vaddr->special_action > 256)) /* Callout was done */
1554 {
1555 new_ok = vaddr->special_action & 255;
1556 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
1557 *ss = terminator; /* Restore shortened string */
1558 }
1559
1560 /* Otherwise we run the verification now. We must restore the shortened
1561 string before running the verification, so the headers are correct, in
1562 case there is any rewriting. */
1563
1564 else
1565 {
1566 int start, end, domain;
1567 uschar *address = parse_extract_address(s, log_msgptr, &start,
1568 &end, &domain, FALSE);
1569
1570 *ss = terminator;
1571
1572 /* If verification failed because of a syntax error, fail this
1573 function, and ensure that the failing address gets added to the error
1574 message. */
1575
1576 if (address == NULL)
1577 {
1578 new_ok = FAIL;
1579 if (*log_msgptr != NULL)
1580 {
1581 while (ss > s && isspace(ss[-1])) ss--;
1582 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
1583 "scanning for sender: %s in \"%.*s\"",
1584 endname - h->text, h->text, *log_msgptr, ss - s, s);
1585 return FAIL;
1586 }
1587 }
1588
2f6603e1 1589 /* Else go ahead with the sender verification. But it isn't *the*
059ec3d9
PH
1590 sender of the message, so set vopt_fake_sender to stop sender_address
1591 being replaced after rewriting or qualification. */
1592
1593 else
1594 {
1595 vaddr = deliver_make_addr(address, FALSE);
1596 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
8e669ac1 1597 callout, callout_overall, callout_connect, se_mailfrom,
4deaf07d 1598 pm_mailfrom, NULL);
059ec3d9
PH
1599 }
1600 }
1601
1602 /* We now have the result, either newly found, or cached. If we are
1603 giving out error details, set a specific user error. This means that the
1604 last of these will be returned to the user if all three fail. We do not
1605 set a log message - the generic one below will be used. */
1606
fe5b5d0b 1607 if (new_ok != OK)
059ec3d9 1608 {
8e669ac1 1609 *verrno = vaddr->basic_errno;
fe5b5d0b
PH
1610 if (smtp_return_error_details)
1611 {
1612 *user_msgptr = string_sprintf("Rejected after DATA: "
1613 "could not verify \"%.*s\" header address\n%s: %s",
1614 endname - h->text, h->text, vaddr->address, vaddr->message);
1615 }
8e669ac1 1616 }
059ec3d9
PH
1617
1618 /* Success or defer */
1619
1620 if (new_ok == OK) return OK;
1621 if (new_ok == DEFER) yield = DEFER;
1622
1623 /* Move on to any more addresses in the header */
1624
1625 s = ss;
1626 }
1627 }
1628 }
1629
1630if (yield == FAIL && *log_msgptr == NULL)
1631 *log_msgptr = US"there is no valid sender in any header line";
1632
1633if (yield == DEFER && *log_msgptr == NULL)
1634 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
1635
1636return yield;
1637}
1638
1639
1640
1641
1642/*************************************************
1643* Get RFC 1413 identification *
1644*************************************************/
1645
1646/* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
1647the timeout is set to zero, then the query is not done. There may also be lists
1648of hosts and nets which are exempt. To guard against malefactors sending
1649non-printing characters which could, for example, disrupt a message's headers,
1650make sure the string consists of printing characters only.
1651
1652Argument:
1653 port the port to connect to; usually this is IDENT_PORT (113), but when
1654 running in the test harness with -bh a different value is used.
1655
1656Returns: nothing
1657
1658Side effect: any received ident value is put in sender_ident (NULL otherwise)
1659*/
1660
1661void
1662verify_get_ident(int port)
1663{
1664int sock, host_af, qlen;
1665int received_sender_port, received_interface_port, n;
1666uschar *p;
1667uschar buffer[2048];
1668
1669/* Default is no ident. Check whether we want to do an ident check for this
1670host. */
1671
1672sender_ident = NULL;
1673if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
1674 return;
1675
1676DEBUG(D_ident) debug_printf("doing ident callback\n");
1677
1678/* Set up a connection to the ident port of the remote host. Bind the local end
1679to the incoming interface address. If the sender host address is an IPv6
1680address, the incoming interface address will also be IPv6. */
1681
1682host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
1683sock = ip_socket(SOCK_STREAM, host_af);
1684if (sock < 0) return;
1685
1686if (ip_bind(sock, host_af, interface_address, 0) < 0)
1687 {
1688 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
1689 strerror(errno));
1690 goto END_OFF;
1691 }
1692
1693if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
1694 < 0)
1695 {
1696 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
1697 {
1698 log_write(0, LOG_MAIN, "ident connection to %s timed out",
1699 sender_host_address);
1700 }
1701 else
1702 {
1703 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
1704 sender_host_address, strerror(errno));
1705 }
1706 goto END_OFF;
1707 }
1708
1709/* Construct and send the query. */
1710
1711sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
1712qlen = Ustrlen(buffer);
1713if (send(sock, buffer, qlen, 0) < 0)
1714 {
1715 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
1716 goto END_OFF;
1717 }
1718
1719/* Read a response line. We put it into the rest of the buffer, using several
1720recv() calls if necessary. */
1721
1722p = buffer + qlen;
1723
1724for (;;)
1725 {
1726 uschar *pp;
1727 int count;
1728 int size = sizeof(buffer) - (p - buffer);
1729
1730 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
1731 count = ip_recv(sock, p, size, rfc1413_query_timeout);
1732 if (count <= 0) goto END_OFF; /* Read error or EOF */
1733
1734 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
1735 generous, and accept a plain \n terminator as well. The only illegal
1736 character is 0. */
1737
1738 for (pp = p; pp < p + count; pp++)
1739 {
1740 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
1741 if (*pp == '\n')
1742 {
1743 if (pp[-1] == '\r') pp--;
1744 *pp = 0;
1745 goto GOT_DATA; /* Break out of both loops */
1746 }
1747 }
1748
1749 /* Reached the end of the data without finding \n. Let the loop continue to
1750 read some more, if there is room. */
1751
1752 p = pp;
1753 }
1754
1755GOT_DATA:
1756
1757/* We have received a line of data. Check it carefully. It must start with the
1758same two port numbers that we sent, followed by data as defined by the RFC. For
1759example,
1760
1761 12345 , 25 : USERID : UNIX :root
1762
1763However, the amount of white space may be different to what we sent. In the
1764"osname" field there may be several sub-fields, comma separated. The data we
1765actually want to save follows the third colon. Some systems put leading spaces
1766in it - we discard those. */
1767
1768if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
1769 &received_interface_port, &n) != 2 ||
1770 received_sender_port != sender_host_port ||
1771 received_interface_port != interface_port)
1772 goto END_OFF;
1773
1774p = buffer + qlen + n;
1775while(isspace(*p)) p++;
1776if (*p++ != ':') goto END_OFF;
1777while(isspace(*p)) p++;
1778if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
1779p += 6;
1780while(isspace(*p)) p++;
1781if (*p++ != ':') goto END_OFF;
1782while (*p != 0 && *p != ':') p++;
1783if (*p++ == 0) goto END_OFF;
1784while(isspace(*p)) p++;
1785if (*p == 0) goto END_OFF;
1786
1787/* The rest of the line is the data we want. We turn it into printing
1788characters when we save it, so that it cannot mess up the format of any logging
1789or Received: lines into which it gets inserted. We keep a maximum of 127
1790characters. */
1791
1792sender_ident = string_printing(string_copyn(p, 127));
1793DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
1794
1795END_OFF:
1796close(sock);
1797return;
1798}
1799
1800
1801
1802
1803/*************************************************
1804* Match host to a single host-list item *
1805*************************************************/
1806
1807/* This function compares a host (name or address) against a single item
1808from a host list. The host name gets looked up if it is needed and is not
1809already known. The function is called from verify_check_this_host() via
1810match_check_list(), which is why most of its arguments are in a single block.
1811
1812Arguments:
1813 arg the argument block (see below)
1814 ss the host-list item
1815 valueptr where to pass back looked up data, or NULL
1816 error for error message when returning ERROR
1817
1818The block contains:
1819 host_name the host name or NULL, implying use sender_host_name and
1820 sender_host_aliases, looking them up if required
1821 host_address the host address
1822 host_ipv4 the IPv4 address taken from an IPv6 one
1823
1824Returns: OK matched
1825 FAIL did not match
1826 DEFER lookup deferred
1827 ERROR failed to find the host name or IP address
1828 unknown lookup type specified
1829*/
1830
1831static int
1832check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
1833{
1834check_host_block *cb = (check_host_block *)arg;
1835int maskoffset;
1836BOOL isquery = FALSE;
1837uschar *semicolon, *t;
1838uschar **aliases;
1839
1840/* Optimize for the special case when the pattern is "*". */
1841
1842if (*ss == '*' && ss[1] == 0) return OK;
1843
1844/* If the pattern is empty, it matches only in the case when there is no host -
1845this can occur in ACL checking for SMTP input using the -bs option. In this
1846situation, the host address is the empty string. */
1847
1848if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
1849if (*ss == 0) return FAIL;
1850
1851/* If the pattern is precisely "@" then match against the primary host name;
1852if it's "@[]" match against the local host's IP addresses. */
1853
1854if (*ss == '@')
1855 {
1856 if (ss[1] == 0) ss = primary_hostname;
1857 else if (Ustrcmp(ss, "@[]") == 0)
1858 {
1859 ip_address_item *ip;
1860 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
1861 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
1862 return FAIL;
1863 }
1864 }
1865
1866/* If the pattern is an IP address, optionally followed by a bitmask count, do
1867a (possibly masked) comparision with the current IP address. */
1868
a5a28604 1869if (string_is_ip_address(ss, &maskoffset) > 0)
059ec3d9
PH
1870 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
1871
1872/* If the item is of the form net[n]-lookup;<file|query> then it is a lookup on
1873a masked IP network, in textual form. The net- stuff really only applies to
1874single-key lookups where the key is implicit. For query-style lookups the key
1875is specified in the query. From release 4.30, the use of net- for query style
1876is no longer needed, but we retain it for backward compatibility. */
1877
1878if (Ustrncmp(ss, "net", 3) == 0 && (semicolon = Ustrchr(ss, ';')) != NULL)
1879 {
1880 int mlen = 0;
1881 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
1882 if (*t++ == '-')
1883 {
1884 int insize;
1885 int search_type;
1886 int incoming[4];
1887 void *handle;
1888 uschar *filename, *key, *result;
1889 uschar buffer[64];
1890
1891 /* If no mask was supplied, set a negative value */
1892
1893 if (mlen == 0 && t == ss+4) mlen = -1;
1894
1895 /* Find the search type */
1896
1897 search_type = search_findtype(t, semicolon - t);
1898
1899 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1900 search_error_message);
1901
1902 /* Adjust parameters for the type of lookup. For a query-style
1903 lookup, there is no file name, and the "key" is just the query. For
1904 a single-key lookup, the key is the current IP address, masked
8e669ac1 1905 appropriately, and reconverted to text form, with the mask appended.
6f0c9a4f 1906 For IPv6 addresses, specify dot separators instead of colons. */
059ec3d9
PH
1907
1908 if (mac_islookup(search_type, lookup_querystyle))
1909 {
1910 filename = NULL;
1911 key = semicolon + 1;
1912 }
1913 else
1914 {
1915 insize = host_aton(cb->host_address, incoming);
1916 host_mask(insize, incoming, mlen);
6f0c9a4f 1917 (void)host_nmtoa(insize, incoming, mlen, buffer, '.');
059ec3d9
PH
1918 key = buffer;
1919 filename = semicolon + 1;
1920 }
1921
1922 /* Now do the actual lookup; note that there is no search_close() because
1923 of the caching arrangements. */
1924
1925 handle = search_open(filename, search_type, 0, NULL, NULL);
1926 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1927 search_error_message);
1928 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
1929 if (valueptr != NULL) *valueptr = result;
1930 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
1931 }
1932 }
1933
1934/* The pattern is not an IP address or network reference of any kind. That is,
1935it is a host name pattern. Check the characters of the pattern to see if they
1936comprise only letters, digits, full stops, and hyphens (the constituents of
1937domain names). Allow underscores, as they are all too commonly found. Sigh.
1938Also, if allow_utf8_domains is set, allow top-bit characters. */
1939
1940for (t = ss; *t != 0; t++)
1941 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
1942 (!allow_utf8_domains || *t < 128)) break;
1943
1944/* If the pattern is a complete domain name, with no fancy characters, look up
1945its IP address and match against that. Note that a multi-homed host will add
1946items to the chain. */
1947
1948if (*t == 0)
1949 {
1950 int rc;
1951 host_item h;
1952 h.next = NULL;
1953 h.name = ss;
1954 h.address = NULL;
1955 h.mx = MX_NONE;
1956 rc = host_find_byname(&h, NULL, NULL, FALSE);
1957 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1958 {
1959 host_item *hh;
1960 for (hh = &h; hh != NULL; hh = hh->next)
1961 {
1962 if (Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)?
1963 cb->host_ipv4 : cb->host_address) == 0)
1964 return OK;
1965 }
1966 return FAIL;
1967 }
1968 if (rc == HOST_FIND_AGAIN) return DEFER;
1969 *error = string_sprintf("failed to find IP address for %s", ss);
1970 return ERROR;
1971 }
1972
1973/* Almost all subsequent comparisons require the host name, and can be done
1974using the general string matching function. When this function is called for
1975outgoing hosts, the name is always given explicitly. If it is NULL, it means we
1976must use sender_host_name and its aliases, looking them up if necessary. */
1977
1978if (cb->host_name != NULL) /* Explicit host name given */
1979 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
1980 valueptr);
1981
1982/* Host name not given; in principle we need the sender host name and its
1983aliases. However, for query-style lookups, we do not need the name if the
1984query does not contain $sender_host_name. From release 4.23, a reference to
1985$sender_host_name causes it to be looked up, so we don't need to do the lookup
1986on spec. */
1987
1988if ((semicolon = Ustrchr(ss, ';')) != NULL)
1989 {
1990 uschar *affix;
1991 int partial, affixlen, starflags, id;
1992
1993 *semicolon = 0;
1994 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
1995 *semicolon=';';
1996
1997 if (id < 0) /* Unknown lookup type */
1998 {
1999 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2000 search_error_message, ss);
2001 return DEFER;
2002 }
2003 isquery = mac_islookup(id, lookup_querystyle);
2004 }
2005
2006if (isquery)
2007 {
2008 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2009 {
2010 case OK: return OK;
2011 case DEFER: return DEFER;
2012 default: return FAIL;
2013 }
2014 }
2015
2016/* Not a query-style lookup; must ensure the host name is present, and then we
2017do a check on the name and all its aliases. */
2018
2019if (sender_host_name == NULL)
2020 {
2021 HDEBUG(D_host_lookup)
2022 debug_printf("sender host name required, to match against %s\n", ss);
2023 if (host_lookup_failed || host_name_lookup() != OK)
2024 {
2025 *error = string_sprintf("failed to find host name for %s",
2026 sender_host_address);;
2027 return ERROR;
2028 }
2029 host_build_sender_fullhost();
2030 }
2031
2032/* Match on the sender host name, using the general matching function */
2033
2034switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2035 valueptr))
2036 {
2037 case OK: return OK;
2038 case DEFER: return DEFER;
2039 }
2040
2041/* If there are aliases, try matching on them. */
2042
2043aliases = sender_host_aliases;
2044while (*aliases != NULL)
2045 {
2046 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2047 {
2048 case OK: return OK;
2049 case DEFER: return DEFER;
2050 }
2051 }
2052return FAIL;
2053}
2054
2055
2056
2057
2058/*************************************************
2059* Check a specific host matches a host list *
2060*************************************************/
2061
2062/* This function is passed a host list containing items in a number of
2063different formats and the identity of a host. Its job is to determine whether
2064the given host is in the set of hosts defined by the list. The host name is
2065passed as a pointer so that it can be looked up if needed and not already
2066known. This is commonly the case when called from verify_check_host() to check
2067an incoming connection. When called from elsewhere the host name should usually
2068be set.
2069
2070This function is now just a front end to match_check_list(), which runs common
2071code for scanning a list. We pass it the check_host() function to perform a
2072single test.
2073
2074Arguments:
2075 listptr pointer to the host list
2076 cache_bits pointer to cache for named lists, or NULL
2077 host_name the host name or NULL, implying use sender_host_name and
2078 sender_host_aliases, looking them up if required
2079 host_address the IP address
2080 valueptr if not NULL, data from a lookup is passed back here
2081
2082Returns: OK if the host is in the defined set
2083 FAIL if the host is not in the defined set,
2084 DEFER if a data lookup deferred (not a host lookup)
2085
2086If the host name was needed in order to make a comparison, and could not be
2087determined from the IP address, the result is FAIL unless the item
2088"+allow_unknown" was met earlier in the list, in which case OK is returned. */
2089
2090int
2091verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2092 uschar *host_name, uschar *host_address, uschar **valueptr)
2093{
d4eb88df 2094int rc;
059ec3d9 2095unsigned int *local_cache_bits = cache_bits;
d4eb88df 2096uschar *save_host_address = deliver_host_address;
059ec3d9
PH
2097check_host_block cb;
2098cb.host_name = host_name;
2099cb.host_address = host_address;
2100
2101if (valueptr != NULL) *valueptr = NULL;
2102
2103/* If the host address starts off ::ffff: it is an IPv6 address in
2104IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2105addresses. */
2106
2107cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2108 host_address + 7 : host_address;
2109
8e669ac1
PH
2110/* During the running of the check, put the IP address into $host_address. In
2111the case of calls from the smtp transport, it will already be there. However,
2112in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
d4eb88df
PH
2113the safe side, any existing setting is preserved, though as I write this
2114(November 2004) I can't see any cases where it is actually needed. */
2115
2116deliver_host_address = host_address;
2117rc = match_check_list(
2118 listptr, /* the list */
2119 0, /* separator character */
2120 &hostlist_anchor, /* anchor pointer */
2121 &local_cache_bits, /* cache pointer */
2122 check_host, /* function for testing */
2123 &cb, /* argument for function */
2124 MCL_HOST, /* type of check */
8e669ac1 2125 (host_address == sender_host_address)?
d4eb88df
PH
2126 US"host" : host_address, /* text for debugging */
2127 valueptr); /* where to pass back data */
2128deliver_host_address = save_host_address;
8e669ac1 2129return rc;
059ec3d9
PH
2130}
2131
2132
2133
2134
2135/*************************************************
2136* Check the remote host matches a list *
2137*************************************************/
2138
2139/* This is a front end to verify_check_this_host(), created because checking
2140the remote host is a common occurrence. With luck, a good compiler will spot
2141the tail recursion and optimize it. If there's no host address, this is
2142command-line SMTP input - check against an empty string for the address.
2143
2144Arguments:
2145 listptr pointer to the host list
2146
2147Returns: the yield of verify_check_this_host(),
2148 i.e. OK, FAIL, or DEFER
2149*/
2150
2151int
2152verify_check_host(uschar **listptr)
2153{
2154return verify_check_this_host(listptr, sender_host_cache, NULL,
2155 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
2156}
2157
2158
2159
2160
2161
2162/*************************************************
2163* Invert an IP address for a DNS black list *
2164*************************************************/
2165
2166/*
2167Arguments:
2168 buffer where to put the answer
2169 address the address to invert
2170*/
2171
2172static void
2173invert_address(uschar *buffer, uschar *address)
2174{
2175int bin[4];
2176uschar *bptr = buffer;
2177
2178/* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
2179to the IPv4 part only. */
2180
2181if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
2182
2183/* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
2184always 1. */
2185
2186if (host_aton(address, bin) == 1)
2187 {
2188 int i;
2189 int x = bin[0];
2190 for (i = 0; i < 4; i++)
2191 {
2192 sprintf(CS bptr, "%d.", x & 255);
2193 while (*bptr) bptr++;
2194 x >>= 8;
2195 }
2196 }
2197
2198/* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
2199in any DNS black lists, and the format in which they will be looked up is
2200unknown. This is just a guess. */
2201
2202#if HAVE_IPV6
2203else
2204 {
2205 int i, j;
2206 for (j = 3; j >= 0; j--)
2207 {
2208 int x = bin[j];
2209 for (i = 0; i < 8; i++)
2210 {
2211 sprintf(CS bptr, "%x.", x & 15);
2212 while (*bptr) bptr++;
2213 x >>= 4;
2214 }
2215 }
2216 }
2217#endif
2218}
2219
2220
2221
2222/*************************************************
0bcb2a0e
PH
2223* Perform a single dnsbl lookup *
2224*************************************************/
2225
2226/* This function is called from verify_check_dnsbl() below.
2227
2228Arguments:
2229 domain the outer dnsbl domain (for debug message)
8e669ac1 2230 keydomain the current keydomain (for debug message)
0bcb2a0e 2231 query the domain to be looked up
8e669ac1
PH
2232 iplist the list of matching IP addresses
2233 bitmask true if bitmask matching is wanted
2234 invert_result true if result to be inverted
2235 defer_return what to return for a defer
0bcb2a0e
PH
2236
2237Returns: OK if lookup succeeded
2238 FAIL if not
2239*/
2240
2241static int
8e669ac1 2242one_check_dnsbl(uschar *domain, uschar *keydomain, uschar *query,
0bcb2a0e 2243 uschar *iplist, BOOL bitmask, BOOL invert_result, int defer_return)
8e669ac1 2244{
0bcb2a0e
PH
2245dns_answer dnsa;
2246dns_scan dnss;
2247tree_node *t;
2248dnsbl_cache_block *cb;
2249int old_pool = store_pool;
2250
2251/* Look for this query in the cache. */
2252
2253t = tree_search(dnsbl_cache, query);
2254
2255/* If not cached from a previous lookup, we must do a DNS lookup, and
2256cache the result in permanent memory. */
2257
2258if (t == NULL)
2259 {
2260 store_pool = POOL_PERM;
2261
2262 /* Set up a tree entry to cache the lookup */
2263
2264 t = store_get(sizeof(tree_node) + Ustrlen(query));
2265 Ustrcpy(t->name, query);
2266 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
2267 (void)tree_insertnode(&dnsbl_cache, t);
2268
2269 /* Do the DNS loopup . */
2270
2271 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
2272 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
2273 cb->text_set = FALSE;
2274 cb->text = NULL;
2275 cb->rhs = NULL;
2276
2277 /* If the lookup succeeded, cache the RHS address. The code allows for
2278 more than one address - this was for complete generality and the possible
2279 use of A6 records. However, A6 records have been reduced to experimental
2280 status (August 2001) and may die out. So they may never get used at all,
2281 let alone in dnsbl records. However, leave the code here, just in case.
2282
2283 Quite apart from one A6 RR generating multiple addresses, there are DNS
2284 lists that return more than one A record, so we must handle multiple
2285 addresses generated in that way as well. */
2286
2287 if (cb->rc == DNS_SUCCEED)
2288 {
2289 dns_record *rr;
2290 dns_address **addrp = &(cb->rhs);
2291 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2292 rr != NULL;
2293 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2294 {
2295 if (rr->type == T_A)
2296 {
2297 dns_address *da = dns_address_from_rr(&dnsa, rr);
2298 if (da != NULL)
2299 {
2300 *addrp = da;
2301 while (da->next != NULL) da = da->next;
2302 addrp = &(da->next);
2303 }
2304 }
2305 }
2306
2307 /* If we didn't find any A records, change the return code. This can
2308 happen when there is a CNAME record but there are no A records for what
2309 it points to. */
2310
2311 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
2312 }
2313
2314 store_pool = old_pool;
2315 }
2316
2317/* Previous lookup was cached */
2318
2319else
2320 {
2321 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
2322 cb = t->data.ptr;
2323 }
2324
2325/* We now have the result of the DNS lookup, either newly done, or cached
2326from a previous call. If the lookup succeeded, check against the address
2327list if there is one. This may be a positive equality list (introduced by
2328"="), a negative equality list (introduced by "!="), a positive bitmask
2329list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
2330
2331if (cb->rc == DNS_SUCCEED)
2332 {
2333 dns_address *da = NULL;
2334 uschar *addlist = cb->rhs->address;
2335
2336 /* For A and AAAA records, there may be multiple addresses from multiple
2337 records. For A6 records (currently not expected to be used) there may be
2338 multiple addresses from a single record. */
2339
2340 for (da = cb->rhs->next; da != NULL; da = da->next)
2341 addlist = string_sprintf("%s, %s", addlist, da->address);
2342
2343 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
2344 query, addlist);
2345
2346 /* Address list check; this can be either for equality, or via a bitmask.
2347 In the latter case, all the bits must match. */
2348
2349 if (iplist != NULL)
2350 {
2351 int ipsep = ',';
2352 uschar ip[46];
2353 uschar *ptr = iplist;
2354
2355 while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL)
2356 {
2357 /* Handle exact matching */
2358 if (!bitmask)
2359 {
2360 for (da = cb->rhs; da != NULL; da = da->next)
2361 {
2362 if (Ustrcmp(CS da->address, ip) == 0) break;
2363 }
2364 }
2365 /* Handle bitmask matching */
2366 else
2367 {
2368 int address[4];
2369 int mask = 0;
2370
2371 /* At present, all known DNS blocking lists use A records, with
2372 IPv4 addresses on the RHS encoding the information they return. I
2373 wonder if this will linger on as the last vestige of IPv4 when IPv6
2374 is ubiquitous? Anyway, for now we use paranoia code to completely
2375 ignore IPv6 addresses. The default mask is 0, which always matches.
2376 We change this only for IPv4 addresses in the list. */
2377
2378 if (host_aton(ip, address) == 1) mask = address[0];
2379
2380 /* Scan the returned addresses, skipping any that are IPv6 */
2381
2382 for (da = cb->rhs; da != NULL; da = da->next)
2383 {
2384 if (host_aton(da->address, address) != 1) continue;
2385 if ((address[0] & mask) == mask) break;
2386 }
2387 }
2388
2389 /* Break out if a match has been found */
2390
2391 if (da != NULL) break;
2392 }
2393
2394 /* If either
2395
2396 (a) No IP address in a positive list matched, or
2397 (b) An IP address in a negative list did match
2398
2399 then behave as if the DNSBL lookup had not succeeded, i.e. the host is
2400 not on the list. */
2401
2402 if (invert_result != (da == NULL))
2403 {
2404 HDEBUG(D_dnsbl)
2405 {
2406 debug_printf("=> but we are not accepting this block class because\n");
2407 debug_printf("=> there was %s match for %c%s\n",
2408 invert_result? "an exclude":"no", bitmask? '&' : '=', iplist);
2409 }
8e669ac1 2410 return FAIL;
0bcb2a0e
PH
2411 }
2412 }
2413
2414 /* Either there was no IP list, or the record matched. Look up a TXT record
2415 if it hasn't previously been done. */
2416
2417 if (!cb->text_set)
2418 {
2419 cb->text_set = TRUE;
2420 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
2421 {
2422 dns_record *rr;
2423 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2424 rr != NULL;
2425 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2426 if (rr->type == T_TXT) break;
2427 if (rr != NULL)
2428 {
2429 int len = (rr->data)[0];
2430 if (len > 511) len = 127;
2431 store_pool = POOL_PERM;
2432 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
2433 store_pool = old_pool;
2434 }
2435 }
2436 }
2437
2438 dnslist_value = addlist;
2439 dnslist_text = cb->text;
2440 return OK;
2441 }
2442
2443/* There was a problem with the DNS lookup */
2444
2445if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
2446 {
2447 log_write(L_dnslist_defer, LOG_MAIN,
2448 "DNS list lookup defer (probably timeout) for %s: %s", query,
2449 (defer_return == OK)? US"assumed in list" :
2450 (defer_return == FAIL)? US"assumed not in list" :
2451 US"returned DEFER");
2452 return defer_return;
2453 }
2454
2455/* No entry was found in the DNS; continue for next domain */
2456
2457HDEBUG(D_dnsbl)
2458 {
2459 debug_printf("DNS lookup for %s failed\n", query);
2460 debug_printf("=> that means %s is not listed at %s\n",
2461 keydomain, domain);
2462 }
2463
2464return FAIL;
2465}
2466
2467
2468
2469
2470/*************************************************
059ec3d9
PH
2471* Check host against DNS black lists *
2472*************************************************/
2473
2474/* This function runs checks against a list of DNS black lists, until one
2475matches. Each item on the list can be of the form
2476
2477 domain=ip-address/key
2478
2479The domain is the right-most domain that is used for the query, for example,
2480blackholes.mail-abuse.org. If the IP address is present, there is a match only
2481if the DNS lookup returns a matching IP address. Several addresses may be
2482given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
2483
2484If no key is given, what is looked up in the domain is the inverted IP address
2485of the current client host. If a key is given, it is used to construct the
2486domain for the lookup. For example,
2487
2488 dsn.rfc-ignorant.org/$sender_address_domain
2489
2490After finding a match in the DNS, the domain is placed in $dnslist_domain, and
2491then we check for a TXT record for an error message, and if found, save its
2492value in $dnslist_text. We also cache everything in a tree, to optimize
2493multiple lookups.
2494
2495Note: an address for testing RBL is 192.203.178.39
2496Note: an address for testing DUL is 192.203.178.4
2497Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
2498
2499Arguments:
2500 listptr the domain/address/data list
2501
2502Returns: OK successful lookup (i.e. the address is on the list), or
2503 lookup deferred after +include_unknown
2504 FAIL name not found, or no data found for the given type, or
2505 lookup deferred after +exclude_unknown (default)
2506 DEFER lookup failure, if +defer_unknown was set
2507*/
2508
2509int
2510verify_check_dnsbl(uschar **listptr)
2511{
2512int sep = 0;
2513int defer_return = FAIL;
059ec3d9
PH
2514BOOL invert_result = FALSE;
2515uschar *list = *listptr;
2516uschar *domain;
2517uschar *s;
2518uschar buffer[1024];
2519uschar query[256]; /* DNS domain max length */
2520uschar revadd[128]; /* Long enough for IPv6 address */
2521
2522/* Indicate that the inverted IP address is not yet set up */
2523
2524revadd[0] = 0;
2525
0bcb2a0e
PH
2526/* In case this is the first time the DNS resolver is being used. */
2527
2528dns_init(FALSE, FALSE);
2529
059ec3d9
PH
2530/* Loop through all the domains supplied, until something matches */
2531
2532while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
2533 {
0bcb2a0e 2534 int rc;
059ec3d9
PH
2535 BOOL frc;
2536 BOOL bitmask = FALSE;
059ec3d9
PH
2537 uschar *iplist;
2538 uschar *key;
059ec3d9
PH
2539
2540 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
2541
2542 /* Deal with special values that change the behaviour on defer */
2543
2544 if (domain[0] == '+')
2545 {
2546 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
2547 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
2548 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
2549 else
2550 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
2551 domain);
2552 continue;
2553 }
2554
2555 /* See if there's explicit data to be looked up */
2556
2557 key = Ustrchr(domain, '/');
2558 if (key != NULL) *key++ = 0;
2559
2560 /* See if there's a list of addresses supplied after the domain name. This is
2561 introduced by an = or a & character; if preceded by ! we invert the result.
2562 */
2563
2564 iplist = Ustrchr(domain, '=');
2565 if (iplist == NULL)
2566 {
2567 bitmask = TRUE;
2568 iplist = Ustrchr(domain, '&');
2569 }
2570
2571 if (iplist != NULL)
2572 {
2573 if (iplist > domain && iplist[-1] == '!')
2574 {
2575 invert_result = TRUE;
2576 iplist[-1] = 0;
2577 }
2578 *iplist++ = 0;
2579 }
2580
2581 /* Check that what we have left is a sensible domain name. There is no reason
2582 why these domains should in fact use the same syntax as hosts and email
2583 domains, but in practice they seem to. However, there is little point in
2584 actually causing an error here, because that would no doubt hold up incoming
2585 mail. Instead, I'll just log it. */
2586
2587 for (s = domain; *s != 0; s++)
2588 {
2589 if (!isalnum(*s) && *s != '-' && *s != '.')
2590 {
2591 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
2592 "strange characters - is this right?", domain);
2593 break;
2594 }
2595 }
2596
8e669ac1 2597 /* If there is no key string, construct the query by adding the domain name
0bcb2a0e 2598 onto the inverted host address, and perform a single DNS lookup. */
8e669ac1 2599
059ec3d9
PH
2600 if (key == NULL)
2601 {
2602 if (sender_host_address == NULL) return FAIL; /* can never match */
2603 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
2604 frc = string_format(query, sizeof(query), "%s%s", revadd, domain);
8e669ac1 2605
0bcb2a0e 2606 if (!frc)
059ec3d9 2607 {
0bcb2a0e
PH
2608 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2609 "(ignored): %s...", query);
2610 continue;
059ec3d9 2611 }
8e669ac1
PH
2612
2613 rc = one_check_dnsbl(domain, sender_host_address, query, iplist, bitmask,
0bcb2a0e 2614 invert_result, defer_return);
8e669ac1 2615
0bcb2a0e
PH
2616 if (rc == OK)
2617 {
2618 dnslist_domain = string_copy(domain);
8e669ac1 2619 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
0bcb2a0e
PH
2620 sender_host_address, domain);
2621 }
8e669ac1 2622
0bcb2a0e 2623 if (rc != FAIL) return rc; /* OK or DEFER */
059ec3d9 2624 }
8e669ac1
PH
2625
2626 /* If there is a key string, it can be a list of domains or IP addresses to
0bcb2a0e 2627 be concatenated with the main domain. */
8e669ac1 2628
059ec3d9
PH
2629 else
2630 {
0bcb2a0e 2631 int keysep = 0;
8e669ac1
PH
2632 BOOL defer = FALSE;
2633 uschar *keydomain;
0bcb2a0e 2634 uschar keybuffer[256];
8e669ac1
PH
2635
2636 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
0bcb2a0e 2637 sizeof(keybuffer))) != NULL)
8e669ac1 2638 {
a5a28604 2639 if (string_is_ip_address(keydomain, NULL) > 0)
059ec3d9 2640 {
0bcb2a0e
PH
2641 uschar keyrevadd[128];
2642 invert_address(keyrevadd, keydomain);
8e669ac1 2643 frc = string_format(query, sizeof(query), "%s%s", keyrevadd, domain);
0bcb2a0e
PH
2644 }
2645 else
8e669ac1 2646 {
0bcb2a0e 2647 frc = string_format(query, sizeof(query), "%s.%s", keydomain, domain);
059ec3d9
PH
2648 }
2649
0bcb2a0e 2650 if (!frc)
059ec3d9 2651 {
0bcb2a0e
PH
2652 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2653 "(ignored): %s...", query);
2654 continue;
059ec3d9 2655 }
8e669ac1
PH
2656
2657 rc = one_check_dnsbl(domain, keydomain, query, iplist, bitmask,
0bcb2a0e 2658 invert_result, defer_return);
8e669ac1 2659
0bcb2a0e 2660 if (rc == OK)
059ec3d9 2661 {
0bcb2a0e 2662 dnslist_domain = string_copy(domain);
8e669ac1 2663 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
0bcb2a0e 2664 keydomain, domain);
8e669ac1 2665 return OK;
059ec3d9 2666 }
8e669ac1 2667
c38d6da9
PH
2668 /* If the lookup deferred, remember this fact. We keep trying the rest
2669 of the list to see if we get a useful result, and if we don't, we return
2670 DEFER at the end. */
059ec3d9 2671
c38d6da9 2672 if (rc == DEFER) defer = TRUE;
0bcb2a0e 2673 } /* continue with next keystring domain/address */
c38d6da9
PH
2674
2675 if (defer) return DEFER;
8e669ac1 2676 }
0bcb2a0e 2677 } /* continue with next dnsdb outer domain */
059ec3d9
PH
2678
2679return FAIL;
2680}
2681
2682/* End of verify.c */