defer_ok was not working if used on a callout with verify=header_sender.
[exim.git] / src / src / verify.c
CommitLineData
fe5b5d0b 1/* $Cambridge: exim/src/src/verify.c,v 1.14 2005/01/27 10:26:14 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
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
136
137Returns: OK/FAIL/DEFER
138*/
139
140static int
141do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
4deaf07d
PH
142 int callout, int callout_overall, int callout_connect, int options,
143 uschar *se_mailfrom, uschar *pm_mailfrom)
059ec3d9
PH
144{
145BOOL is_recipient = (options & vopt_is_recipient) != 0;
146BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
147BOOL callout_random = (options & vopt_callout_random) != 0;
148
149int yield = OK;
150BOOL done = FALSE;
151uschar *address_key;
152uschar *from_address;
153uschar *random_local_part = NULL;
2c7db3f5
PH
154uschar **failure_ptr = is_recipient?
155 &recipient_verify_failure : &sender_verify_failure;
059ec3d9
PH
156open_db dbblock;
157open_db *dbm_file = NULL;
158dbdata_callout_cache new_domain_record;
159dbdata_callout_cache_address new_address_record;
160host_item *host;
161time_t callout_start_time;
162
163new_domain_record.result = ccache_unknown;
164new_domain_record.postmaster_result = ccache_unknown;
165new_domain_record.random_result = ccache_unknown;
166
167memset(&new_address_record, 0, sizeof(new_address_record));
168
169/* For a recipient callout, the key used for the address cache record must
170include the sender address if we are using the real sender in the callout,
171because that may influence the result of the callout. */
172
173address_key = addr->address;
174from_address = US"";
175
176if (is_recipient)
177 {
178 if ((options & vopt_callout_recipsender) != 0)
179 {
180 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
181 from_address = sender_address;
182 }
183 else if ((options & vopt_callout_recippmaster) != 0)
184 {
185 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
186 qualify_domain_sender);
187 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
188 }
189 }
190
191/* For a sender callout, we must adjust the key if the mailfrom address is not
192empty. */
193
194else
195 {
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);
199 }
200
201/* Open the callout cache database, it it exists, for reading only at this
202stage, unless caching has been disabled. */
203
204if (callout_no_cache)
205 {
206 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
207 }
208else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
209 {
210 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
211 }
212
213/* If a cache database is available see if we can avoid the need to do an
214actual callout by making use of previously-obtained data. */
215
216if (dbm_file != NULL)
217 {
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);
223
224 /* If an unexpired cache record was found for this domain, see if the callout
225 process can be short-circuited. */
226
227 if (cache_record != NULL)
228 {
229 /* If an early command (up to and including MAIL FROM:<>) was rejected,
230 there is no point carrying on. The callout fails. */
231
232 if (cache_record->result == ccache_reject)
233 {
234 setflag(addr, af_verify_nsfail);
235 HDEBUG(D_verify)
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).";
240 yield = FAIL;
2c7db3f5 241 *failure_ptr = US"mail";
059ec3d9
PH
242 goto END_CALLOUT;
243 }
244
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. */
251
252 if (callout_random) switch(cache_record->random_result)
253 {
254 case ccache_accept:
255 HDEBUG(D_verify)
256 debug_printf("callout cache: domain accepts random addresses\n");
257 goto END_CALLOUT; /* Default yield is OK */
258
259 case ccache_reject:
260 HDEBUG(D_verify)
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;
265 break;
266
267 default:
268 HDEBUG(D_verify)
269 debug_printf("callout cache: need to check random address handling "
270 "(not cached or cache expired)\n");
271 goto END_CACHE;
272 }
273
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. */
278
279 if (pm_mailfrom != NULL)
280 {
281 if (cache_record->postmaster_result == ccache_reject)
282 {
283 setflag(addr, af_verify_pmfail);
284 HDEBUG(D_verify)
285 debug_printf("callout cache: domain does not accept "
286 "RCPT TO:<postmaster@domain>\n");
287 yield = FAIL;
2c7db3f5 288 *failure_ptr = US"postmaster";
059ec3d9
PH
289 setflag(addr, af_verify_pmfail);
290 addr->user_message = US"(result of earlier verification reused).";
291 goto END_CALLOUT;
292 }
293 if (cache_record->postmaster_result == ccache_unknown)
294 {
295 HDEBUG(D_verify)
296 debug_printf("callout cache: need to check RCPT "
297 "TO:<postmaster@domain> (not cached or cache expired)\n");
298 goto END_CACHE;
299 }
300
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).
304 */
305
306 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
307 "TO:<postmaster@domain>\n");
308 pm_mailfrom = NULL;
309 new_domain_record.postmaster_result = ccache_accept;
310 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
311 }
312 }
313
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).
317 */
318
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);
324
325 if (cache_address_record != NULL)
326 {
327 if (cache_address_record->result == ccache_accept)
328 {
329 HDEBUG(D_verify)
330 debug_printf("callout cache: address record is positive\n");
331 }
332 else
333 {
334 HDEBUG(D_verify)
335 debug_printf("callout cache: address record is negative\n");
336 addr->user_message = US"Previous (cached) callout verification failure";
2c7db3f5 337 *failure_ptr = US"recipient";
059ec3d9
PH
338 yield = FAIL;
339 }
340 goto END_CALLOUT;
341 }
342
343 /* Close the cache database while we actually do the callout for real. */
344
345 END_CACHE:
346 dbfn_close(dbm_file);
347 dbm_file = NULL;
348 }
349
350/* The information wasn't available in the cache, so we have to do a real
351callout and save the result in the cache for next time, unless no_cache is set,
352or unless we have a previously cached negative random result. If we are to test
353with a random local part, ensure that such a local part is available. If not,
354log the fact, but carry on without randomming. */
355
356if (callout_random && callout_random_local_part != NULL)
357 {
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);
362 }
363
4deaf07d
PH
364/* Default the connect and overall callout timeouts if not set, and record the
365time we are starting so that we can enforce it. */
059ec3d9
PH
366
367if (callout_overall < 0) callout_overall = 4 * callout;
4deaf07d 368if (callout_connect < 0) callout_connect = callout;
059ec3d9
PH
369callout_start_time = time(NULL);
370
371/* Now make connections to the hosts and do real callouts. The list of hosts
372is passed in as an argument. */
373
374for (host = host_list; host != NULL && !done; host = host->next)
375 {
376 smtp_inblock inblock;
377 smtp_outblock outblock;
378 int host_af;
379 int port = 25;
c9bdd01c 380 BOOL send_quit = TRUE;
059ec3d9
PH
381 uschar *helo = US"HELO";
382 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
383 uschar inbuffer[4096];
384 uschar outbuffer[1024];
385 uschar responsebuffer[4096];
386
387 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
388 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
389
390 /* Skip this host if we don't have an IP address for it. */
391
392 if (host->address == NULL)
393 {
394 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
395 host->name);
396 continue;
397 }
398
399 /* Check the overall callout timeout */
400
401 if (time(NULL) - callout_start_time >= callout_overall)
402 {
403 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
404 break;
405 }
406
407 /* Set IPv4 or IPv6 */
408
409 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
410
411 /* Expand and interpret the interface and port strings. This has to
412 be delayed till now, because they may expand differently for different
413 hosts. If there's a failure, log it, but carry on with the defaults. */
414
415 deliver_host = host->name;
416 deliver_host_address = host->address;
417 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
418 US"callout") ||
419 !smtp_get_port(tf->port, addr, &port, US"callout"))
420 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
421 addr->message);
422 deliver_host = deliver_host_address = NULL;
423
424 /* Set HELO string according to the protocol */
425
426 if (Ustrcmp(tf->protocol, "lmtp") == 0) helo = US"LHLO";
427
428 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
429
430 /* Set up the buffer for reading SMTP response packets. */
431
432 inblock.buffer = inbuffer;
433 inblock.buffersize = sizeof(inbuffer);
434 inblock.ptr = inbuffer;
435 inblock.ptrend = inbuffer;
436
437 /* Set up the buffer for holding SMTP commands while pipelining */
438
439 outblock.buffer = outbuffer;
440 outblock.buffersize = sizeof(outbuffer);
441 outblock.ptr = outbuffer;
442 outblock.cmd_count = 0;
443 outblock.authenticating = FALSE;
444
445 /* Connect to the host; on failure, just loop for the next one, but we
4deaf07d 446 set the error for the last one. Use the callout_connect timeout. */
059ec3d9
PH
447
448 inblock.sock = outblock.sock =
4deaf07d 449 smtp_connect(host, host_af, port, interface, callout_connect, TRUE);
059ec3d9
PH
450 if (inblock.sock < 0)
451 {
452 addr->message = string_sprintf("could not connect to %s [%s]: %s",
453 host->name, host->address, strerror(errno));
454 continue;
455 }
456
457 /* Wait for initial response, and then run the initial SMTP commands. The
458 smtp_write_command() function leaves its command in big_buffer. This is
459 used in error responses. Initialize it in case the connection is
460 rejected. */
461
462 Ustrcpy(big_buffer, "initial connection");
463
464 done =
465 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
466 '2', callout) &&
467
468 smtp_write_command(&outblock, FALSE, "%s %s\r\n", helo,
469 smtp_active_hostname) >= 0 &&
470 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
471 '2', callout) &&
472
473 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
474 from_address) >= 0 &&
475 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
476 '2', callout);
477
478 /* If the host gave an initial error, or does not accept HELO or MAIL
479 FROM:<>, arrange to cache this information, but don't record anything for an
480 I/O error or a defer. Do not cache rejections when a non-empty sender has
481 been used, because that blocks the whole domain for all senders. */
482
483 if (!done)
484 {
2c7db3f5 485 *failure_ptr = US"mail";
059ec3d9
PH
486 if (errno == 0 && responsebuffer[0] == '5')
487 {
488 setflag(addr, af_verify_nsfail);
489 if (from_address[0] == 0) new_domain_record.result = ccache_reject;
490 }
491 }
492
493 /* Otherwise, proceed to check a "random" address (if required), then the
494 given address, and the postmaster address (if required). Between each check,
495 issue RSET, because some servers accept only one recipient after MAIL
496 FROM:<>. */
497
498 else
499 {
500 new_domain_record.result = ccache_accept;
501
502 /* Do the random local part check first */
503
504 if (random_local_part != NULL)
505 {
506 uschar randombuffer[1024];
507 BOOL random_ok =
508 smtp_write_command(&outblock, FALSE,
509 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
510 addr->domain) >= 0 &&
511 smtp_read_response(&inblock, randombuffer,
512 sizeof(randombuffer), '2', callout);
513
514 /* Remember when we last did a random test */
515
516 new_domain_record.random_stamp = time(NULL);
517
518 /* If accepted, we aren't going to do any further tests below. */
519
520 if (random_ok)
521 {
522 new_domain_record.random_result = ccache_accept;
523 }
524
525 /* Otherwise, cache a real negative response, and get back to the right
526 state to send RCPT. Unless there's some problem such as a dropped
527 connection, we expect to succeed, because the commands succeeded above. */
528
529 else if (errno == 0)
530 {
531 if (randombuffer[0] == '5')
532 new_domain_record.random_result = ccache_reject;
533
534 done =
535 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
536 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
537 '2', callout) &&
538
539 smtp_write_command(&outblock, FALSE, "MAIL FROM:<>\r\n") >= 0 &&
540 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
541 '2', callout);
542 }
543 else done = FALSE; /* Some timeout/connection problem */
544 } /* Random check */
545
546 /* If the host is accepting all local parts, as determined by the "random"
547 check, we don't need to waste time doing any further checking. */
548
549 if (new_domain_record.random_result != ccache_accept && done)
550 {
551 done =
552 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
553 addr->address) >= 0 &&
554 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
555 '2', callout);
556
557 if (done)
558 new_address_record.result = ccache_accept;
559 else if (errno == 0 && responsebuffer[0] == '5')
2c7db3f5
PH
560 {
561 *failure_ptr = US"recipient";
059ec3d9 562 new_address_record.result = ccache_reject;
2c7db3f5 563 }
059ec3d9
PH
564
565 /* Do postmaster check if requested */
566
567 if (done && pm_mailfrom != NULL)
568 {
569 done =
570 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
571 smtp_read_response(&inblock, responsebuffer,
572 sizeof(responsebuffer), '2', callout) &&
573
574 smtp_write_command(&outblock, FALSE,
575 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
576 smtp_read_response(&inblock, responsebuffer,
577 sizeof(responsebuffer), '2', callout) &&
578
579 smtp_write_command(&outblock, FALSE,
580 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
581 smtp_read_response(&inblock, responsebuffer,
582 sizeof(responsebuffer), '2', callout);
583
584 new_domain_record.postmaster_stamp = time(NULL);
585
586 if (done)
587 new_domain_record.postmaster_result = ccache_accept;
588 else if (errno == 0 && responsebuffer[0] == '5')
589 {
2c7db3f5 590 *failure_ptr = US"postmaster";
059ec3d9
PH
591 setflag(addr, af_verify_pmfail);
592 new_domain_record.postmaster_result = ccache_reject;
593 }
594 }
595 } /* Random not accepted */
596 } /* MAIL FROM:<> accepted */
597
598 /* For any failure of the main check, other than a negative response, we just
599 close the connection and carry on. We can identify a negative response by the
600 fact that errno is zero. For I/O errors it will be non-zero
601
602 Set up different error texts for logging and for sending back to the caller
603 as an SMTP response. Log in all cases, using a one-line format. For sender
604 callouts, give a full response to the caller, but for recipient callouts,
605 don't give the IP address because this may be an internal host whose identity
606 is not to be widely broadcast. */
607
608 if (!done)
609 {
610 if (errno == ETIMEDOUT)
611 {
612 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
c9bdd01c 613 send_quit = FALSE;
059ec3d9
PH
614 }
615 else if (errno == 0)
616 {
617 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
618
619 addr->message =
620 string_sprintf("response to \"%s\" from %s [%s] was: %s",
621 big_buffer, host->name, host->address,
622 string_printing(responsebuffer));
623
624 addr->user_message = is_recipient?
625 string_sprintf("Callout verification failed:\n%s", responsebuffer)
626 :
627 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
628 host->address, big_buffer, responsebuffer);
629
630 /* Hard rejection ends the process */
631
632 if (responsebuffer[0] == '5') /* Address rejected */
633 {
634 yield = FAIL;
635 done = TRUE;
636 }
637 }
638 }
639
640 /* End the SMTP conversation and close the connection. */
641
c9bdd01c 642 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
059ec3d9
PH
643 close(inblock.sock);
644 } /* Loop through all hosts, while !done */
645
646/* If we get here with done == TRUE, a successful callout happened, and yield
647will be set OK or FAIL according to the response to the RCPT command.
648Otherwise, we looped through the hosts but couldn't complete the business.
649However, there may be domain-specific information to cache in both cases.
650
651The value of the result field in the new_domain record is ccache_unknown if
652there was an error before or with MAIL FROM:<>, and errno was not zero,
653implying some kind of I/O error. We don't want to write the cache in that case.
654Otherwise the value is ccache_accept or ccache_reject. */
655
656if (!callout_no_cache && new_domain_record.result != ccache_unknown)
657 {
658 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
659 == NULL)
660 {
661 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
662 }
663 else
664 {
665 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
666 (int)sizeof(dbdata_callout_cache));
667 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
668 " result=%d postmaster=%d random=%d\n",
669 new_domain_record.result,
670 new_domain_record.postmaster_result,
671 new_domain_record.random_result);
672 }
673 }
674
675/* If a definite result was obtained for the callout, cache it unless caching
676is disabled. */
677
678if (done)
679 {
680 if (!callout_no_cache && new_address_record.result != ccache_unknown)
681 {
682 if (dbm_file == NULL)
683 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
684 if (dbm_file == NULL)
685 {
686 HDEBUG(D_verify) debug_printf("no callout cache available\n");
687 }
688 else
689 {
690 (void)dbfn_write(dbm_file, address_key, &new_address_record,
691 (int)sizeof(dbdata_callout_cache_address));
692 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
693 (new_address_record.result == ccache_accept)? "positive" : "negative");
694 }
695 }
696 } /* done */
697
698/* Failure to connect to any host, or any response other than 2xx or 5xx is a
699temporary error. If there was only one host, and a response was received, leave
700it alone if supplying details. Otherwise, give a generic response. */
701
702else /* !done */
703 {
704 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
705 is_recipient? "recipient" : "sender");
706 yield = DEFER;
707
708 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
709
710 addr->user_message = (!smtp_return_error_details)? dullmsg :
711 string_sprintf("%s for <%s>.\n"
712 "The mail server(s) for the domain may be temporarily unreachable, or\n"
713 "they may be permanently unreachable from this server. In the latter case,\n%s",
714 dullmsg, addr->address,
715 is_recipient?
716 "the address will never be accepted."
717 :
718 "you need to change the address or create an MX record for its domain\n"
719 "if it is supposed to be generally accessible from the Internet.\n"
720 "Talk to your mail administrator for details.");
721
722 /* Force a specific error code */
723
724 addr->basic_errno = ERRNO_CALLOUTDEFER;
725 }
726
727/* Come here from within the cache-reading code on fast-track exit. */
728
729END_CALLOUT:
730if (dbm_file != NULL) dbfn_close(dbm_file);
731return yield;
732}
733
734
735
736/*************************************************
737* Copy error to toplevel address *
738*************************************************/
739
740/* This function is used when a verify fails or defers, to ensure that the
741failure or defer information is in the original toplevel address. This applies
742when an address is redirected to a single new address, and the failure or
743deferral happens to the child address.
744
745Arguments:
746 vaddr the verify address item
747 addr the final address item
748 yield FAIL or DEFER
749
750Returns: the value of YIELD
751*/
752
753static int
754copy_error(address_item *vaddr, address_item *addr, int yield)
755{
756if (addr != vaddr)
757 {
758 vaddr->message = addr->message;
759 vaddr->user_message = addr->user_message;
760 vaddr->basic_errno = addr->basic_errno;
761 vaddr->more_errno = addr->more_errno;
762 }
763return yield;
764}
765
766
767
768
769/*************************************************
770* Verify an email address *
771*************************************************/
772
773/* This function is used both for verification (-bv and at other times) and
774address testing (-bt), which is indicated by address_test_mode being set.
775
776Arguments:
777 vaddr contains the address to verify; the next field in this block
778 must be NULL
779 f if not NULL, write the result to this file
780 options various option bits:
781 vopt_fake_sender => this sender verify is not for the real
782 sender (it was verify=sender=xxxx or an address from a
783 header line) - rewriting must not change sender_address
784 vopt_is_recipient => this is a recipient address, otherwise
785 it's a sender address - this affects qualification and
786 rewriting and messages from callouts
787 vopt_qualify => qualify an unqualified address; else error
788 vopt_expn => called from SMTP EXPN command
789
790 These ones are used by do_callout() -- the options variable
791 is passed to it.
792
793 vopt_callout_no_cache => don't use callout cache
794 vopt_callout_random => do the "random" thing
795 vopt_callout_recipsender => use real sender for recipient
796 vopt_callout_recippmaster => use postmaster for recipient
797
798 callout if > 0, specifies that callout is required, and gives timeout
4deaf07d 799 for individual commands
059ec3d9
PH
800 callout_overall if > 0, gives overall timeout for the callout function;
801 if < 0, a default is used (see do_callout())
4deaf07d 802 callout_connect the connection timeout for callouts
059ec3d9
PH
803 se_mailfrom when callout is requested to verify a sender, use this
804 in MAIL FROM; NULL => ""
805 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
806 thing and use this as the sender address (may be "")
807
808 routed if not NULL, set TRUE if routing succeeded, so we can
809 distinguish between routing failed and callout failed
810
811Returns: OK address verified
812 FAIL address failed to verify
813 DEFER can't tell at present
814*/
815
816int
817verify_address(address_item *vaddr, FILE *f, int options, int callout,
4deaf07d
PH
818 int callout_overall, int callout_connect, uschar *se_mailfrom,
819 uschar *pm_mailfrom, BOOL *routed)
059ec3d9
PH
820{
821BOOL allok = TRUE;
822BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
823BOOL is_recipient = (options & vopt_is_recipient) != 0;
824BOOL expn = (options & vopt_expn) != 0;
059ec3d9
PH
825int i;
826int yield = OK;
827int verify_type = expn? v_expn :
828 address_test_mode? v_none :
829 is_recipient? v_recipient : v_sender;
830address_item *addr_list;
831address_item *addr_new = NULL;
832address_item *addr_remote = NULL;
833address_item *addr_local = NULL;
834address_item *addr_succeed = NULL;
2c7db3f5
PH
835uschar **failure_ptr = is_recipient?
836 &recipient_verify_failure : &sender_verify_failure;
059ec3d9
PH
837uschar *ko_prefix, *cr;
838uschar *address = vaddr->address;
839uschar *save_sender;
840uschar null_sender[] = { 0 }; /* Ensure writeable memory */
841
2c7db3f5
PH
842/* Clear, just in case */
843
844*failure_ptr = NULL;
845
059ec3d9
PH
846/* Set up a prefix and suffix for error message which allow us to use the same
847output statements both in EXPN mode (where an SMTP response is needed) and when
848debugging with an output file. */
849
850if (expn)
851 {
852 ko_prefix = US"553 ";
853 cr = US"\r";
854 }
855else ko_prefix = cr = US"";
856
857/* Add qualify domain if permitted; otherwise an unqualified address fails. */
858
859if (parse_find_at(address) == NULL)
860 {
861 if ((options & vopt_qualify) == 0)
862 {
863 if (f != NULL)
864 fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address,
865 cr);
2c7db3f5 866 *failure_ptr = US"qualify";
059ec3d9
PH
867 return FAIL;
868 }
869 address = rewrite_address_qualify(address, is_recipient);
870 }
871
872DEBUG(D_verify)
873 {
874 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
875 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
876 }
877
878/* Rewrite and report on it. Clear the domain and local part caches - these
879may have been set by domains and local part tests during an ACL. */
880
881if (global_rewrite_rules != NULL)
882 {
883 uschar *old = address;
884 address = rewrite_address(address, is_recipient, FALSE,
885 global_rewrite_rules, rewrite_existflags);
886 if (address != old)
887 {
888 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
889 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
890 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
891 }
892 }
893
894/* If this is the real sender address, we must update sender_address at
895this point, because it may be referred to in the routers. */
896
897if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
898 sender_address = address;
899
900/* If the address was rewritten to <> no verification can be done, and we have
901to return OK. This rewriting is permitted only for sender addresses; for other
902addresses, such rewriting fails. */
903
904if (address[0] == 0) return OK;
905
906/* Save a copy of the sender address for re-instating if we change it to <>
907while verifying a sender address (a nice bit of self-reference there). */
908
909save_sender = sender_address;
910
911/* Update the address structure with the possibly qualified and rewritten
912address. Set it up as the starting address on the chain of new addresses. */
913
914vaddr->address = address;
915addr_new = vaddr;
916
917/* We need a loop, because an address can generate new addresses. We must also
918cope with generated pipes and files at the top level. (See also the code and
919comment in deliver.c.) However, it is usually the case that the router for
920user's .forward files has its verify flag turned off.
921
922If an address generates more than one child, the loop is used only when
923full_info is set, and this can only be set locally. Remote enquiries just get
924information about the top level address, not anything that it generated. */
925
926while (addr_new != NULL)
927 {
928 int rc;
929 address_item *addr = addr_new;
930
931 addr_new = addr->next;
932 addr->next = NULL;
933
934 DEBUG(D_verify)
935 {
936 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
937 debug_printf("Considering %s\n", addr->address);
938 }
939
940 /* Handle generated pipe, file or reply addresses. We don't get these
941 when handling EXPN, as it does only one level of expansion. */
942
943 if (testflag(addr, af_pfr))
944 {
945 allok = FALSE;
946 if (f != NULL)
947 {
948 BOOL allow;
949
950 if (addr->address[0] == '>')
951 {
952 allow = testflag(addr, af_allow_reply);
953 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
954 }
955 else
956 {
957 allow = (addr->address[0] == '|')?
958 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
959 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
960 }
961
962 if (addr->basic_errno == ERRNO_BADTRANSPORT)
963 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
964 "%s\n", addr->message);
965 else if (allow)
966 fprintf(f, "\n transport = %s\n", addr->transport->name);
967 else
968 fprintf(f, " *** forbidden ***\n");
969 }
970 continue;
971 }
972
973 /* Just in case some router parameter refers to it. */
974
975 return_path = (addr->p.errors_address != NULL)?
976 addr->p.errors_address : sender_address;
977
978 /* Split the address into domain and local part, handling the %-hack if
979 necessary, and then route it. While routing a sender address, set
980 $sender_address to <> because that is what it will be if we were trying to
981 send a bounce to the sender. */
982
983 if (routed != NULL) *routed = FALSE;
984 if ((rc = deliver_split_address(addr)) == OK)
985 {
986 if (!is_recipient) sender_address = null_sender;
987 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
988 &addr_succeed, verify_type);
989 sender_address = save_sender; /* Put back the real sender */
990 }
991
992 /* If routing an address succeeded, set the flag that remembers, for use when
993 an ACL cached a sender verify (in case a callout fails). Then if routing set
994 up a list of hosts or the transport has a host list, and the callout option
995 is set, and we aren't in a host checking run, do the callout verification,
996 and set another flag that notes that a callout happened. */
997
998 if (rc == OK)
999 {
1000 if (routed != NULL) *routed = TRUE;
1001 if (callout > 0)
1002 {
1003 host_item *host_list = addr->host_list;
1004
1005 /* Default, if no remote transport, to NULL for the interface (=> any),
1006 "smtp" for the port, and "smtp" for the protocol. */
1007
1008 transport_feedback tf = { NULL, US"smtp", US"smtp", NULL, FALSE, FALSE };
1009
1010 /* If verification yielded a remote transport, we want to use that
1011 transport's options, so as to mimic what would happen if we were really
1012 sending a message to this address. */
1013
1014 if (addr->transport != NULL && !addr->transport->info->local)
1015 {
1016 (void)(addr->transport->setup)(addr->transport, addr, &tf, NULL);
1017
1018 /* If the transport has hosts and the router does not, or if the
1019 transport is configured to override the router's hosts, we must build a
1020 host list of the transport's hosts, and find the IP addresses */
1021
1022 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1023 {
1024 uschar *s;
1025
1026 host_list = NULL; /* Ignore the router's hosts */
1027
1028 deliver_domain = addr->domain;
1029 deliver_localpart = addr->local_part;
1030 s = expand_string(tf.hosts);
1031 deliver_domain = deliver_localpart = NULL;
1032
1033 if (s == NULL)
1034 {
1035 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1036 "\"%s\" in %s transport for callout: %s", tf.hosts,
1037 addr->transport->name, expand_string_message);
1038 }
1039 else
1040 {
1041 uschar *canonical_name;
d8ef3577 1042 host_item *host, *nexthost;
059ec3d9
PH
1043 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1044
1045 /* Just ignore failures to find a host address. If we don't manage
d8ef3577
PH
1046 to find any addresses, the callout will defer. Note that more than
1047 one address may be found for a single host, which will result in
1048 additional host items being inserted into the chain. Hence we must
1049 save the next host first. */
059ec3d9 1050
d8ef3577 1051 for (host = host_list; host != NULL; host = nexthost)
059ec3d9 1052 {
d8ef3577 1053 nexthost = host->next;
a5a28604
PH
1054 if (tf.gethostbyname ||
1055 string_is_ip_address(host->name, NULL) > 0)
059ec3d9
PH
1056 (void)host_find_byname(host, NULL, &canonical_name, TRUE);
1057 else
1058 {
1059 int flags = HOST_FIND_BY_A;
1060 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1061 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1062 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1063 &canonical_name, NULL);
1064 }
1065 }
1066 }
1067 }
1068 }
1069
2c7db3f5
PH
1070 /* Can only do a callout if we have at least one host! If the callout
1071 fails, it will have set ${sender,recipient}_verify_failure. */
059ec3d9
PH
1072
1073 if (host_list != NULL)
1074 {
1075 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1076 if (host_checking && !host_checking_callout)
1077 {
1078 HDEBUG(D_verify)
1079 debug_printf("... callout omitted by default when host testing\n"
1080 "(Use -bhc if you want the callouts to happen.)\n");
1081 }
1082 else
1083 {
1084 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
4deaf07d 1085 callout_connect, options, se_mailfrom, pm_mailfrom);
059ec3d9
PH
1086 }
1087 }
1088 else
1089 {
1090 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1091 "transport provided a host list\n");
1092 }
1093 }
1094 }
2c7db3f5
PH
1095
1096 /* Otherwise, any failure is a routing failure */
1097
1098 else *failure_ptr = US"route";
059ec3d9
PH
1099
1100 /* A router may return REROUTED if it has set up a child address as a result
1101 of a change of domain name (typically from widening). In this case we always
1102 want to continue to verify the new child. */
1103
1104 if (rc == REROUTED) continue;
6729cf78 1105
059ec3d9
PH
1106 /* Handle hard failures */
1107
1108 if (rc == FAIL)
1109 {
1110 allok = FALSE;
1111 if (f != NULL)
1112 {
1113 fprintf(f, "%s%s %s", ko_prefix, address,
1114 address_test_mode? "is undeliverable" : "failed to verify");
1115 if (!expn && admin_user)
1116 {
1117 if (addr->basic_errno > 0)
1118 fprintf(f, ": %s", strerror(addr->basic_errno));
1119 if (addr->message != NULL)
1120 fprintf(f, ":\n %s", addr->message);
1121 }
1122 fprintf(f, "%s\n", cr);
1123 }
1124
1125 if (!full_info) return copy_error(vaddr, addr, FAIL);
1126 else yield = FAIL;
1127 }
1128
1129 /* Soft failure */
1130
1131 else if (rc == DEFER)
1132 {
1133 allok = FALSE;
1134 if (f != NULL)
1135 {
1136 fprintf(f, "%s%s cannot be resolved at this time", ko_prefix, address);
1137 if (!expn && admin_user)
1138 {
1139 if (addr->basic_errno > 0)
1140 fprintf(f, ":\n %s", strerror(addr->basic_errno));
1141 if (addr->message != NULL)
1142 fprintf(f, ":\n %s", addr->message);
1143 else if (addr->basic_errno <= 0)
1144 fprintf(f, ":\n unknown error");
1145 }
1146
1147 fprintf(f, "%s\n", cr);
1148 }
1149 if (!full_info) return copy_error(vaddr, addr, DEFER);
1150 else if (yield == OK) yield = DEFER;
1151 }
1152
1153 /* If we are handling EXPN, we do not want to continue to route beyond
1154 the top level. */
1155
1156 else if (expn)
1157 {
1158 uschar *ok_prefix = US"250-";
1159 if (addr_new == NULL)
1160 {
1161 if (addr_local == NULL && addr_remote == NULL)
1162 fprintf(f, "250 mail to <%s> is discarded\r\n", address);
1163 else
1164 fprintf(f, "250 <%s>\r\n", address);
1165 }
1166 else while (addr_new != NULL)
1167 {
1168 address_item *addr2 = addr_new;
1169 addr_new = addr2->next;
1170 if (addr_new == NULL) ok_prefix = US"250 ";
1171 fprintf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1172 }
1173 return OK;
1174 }
1175
1176 /* Successful routing other than EXPN. */
1177
1178 else
1179 {
1180 /* Handle successful routing when short info wanted. Otherwise continue for
1181 other (generated) addresses. Short info is the operational case. Full info
1182 can be requested only when debug_selector != 0 and a file is supplied.
1183
1184 There is a conflict between the use of aliasing as an alternate email
1185 address, and as a sort of mailing list. If an alias turns the incoming
1186 address into just one address (e.g. J.Caesar->jc44) you may well want to
1187 carry on verifying the generated address to ensure it is valid when
1188 checking incoming mail. If aliasing generates multiple addresses, you
1189 probably don't want to do this. Exim therefore treats the generation of
1190 just a single new address as a special case, and continues on to verify the
1191 generated address. */
1192
1193 if (!full_info && /* Stop if short info wanted AND */
1194 (addr_new == NULL || /* No new address OR */
1195 addr_new->next != NULL || /* More than one new address OR */
1196 testflag(addr_new, af_pfr))) /* New address is pfr */
1197 {
1198 if (f != NULL) fprintf(f, "%s %s\n", address,
1199 address_test_mode? "is deliverable" : "verified");
1200
1201 /* If we have carried on to verify a child address, we want the value
1202 of $address_data to be that of the child */
1203
1204 vaddr->p.address_data = addr->p.address_data;
1205 return OK;
1206 }
1207 }
1208 } /* Loop for generated addresses */
1209
1210/* Display the full results of the successful routing, including any generated
1211addresses. Control gets here only when full_info is set, which requires f not
1212to be NULL, and this occurs only when a top-level verify is called with the
1213debugging switch on.
1214
1215If there are no local and no remote addresses, and there were no pipes, files,
1216or autoreplies, and there were no errors or deferments, the message is to be
1217discarded, usually because of the use of :blackhole: in an alias file. */
1218
1219if (allok && addr_local == NULL && addr_remote == NULL)
1220 fprintf(f, "mail to %s is discarded\n", address);
1221
1222else for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1223 {
1224 while (addr_list != NULL)
1225 {
1226 address_item *addr = addr_list;
1227 address_item *p = addr->parent;
1228 addr_list = addr->next;
1229
1230 fprintf(f, "%s", CS addr->address);
1231 while (p != NULL)
1232 {
1233 fprintf(f, "\n <-- %s", p->address);
1234 p = p->parent;
1235 }
1236 fprintf(f, "\n ");
1237
1238 /* Show router, and transport */
1239
1240 fprintf(f, "router = %s, ", addr->router->name);
1241 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1242 addr->transport->name);
1243
1244 /* Show any hosts that are set up by a router unless the transport
1245 is going to override them; fiddle a bit to get a nice format. */
1246
1247 if (addr->host_list != NULL && addr->transport != NULL &&
1248 !addr->transport->overrides_hosts)
1249 {
1250 host_item *h;
1251 int maxlen = 0;
1252 int maxaddlen = 0;
1253 for (h = addr->host_list; h != NULL; h = h->next)
1254 {
1255 int len = Ustrlen(h->name);
1256 if (len > maxlen) maxlen = len;
1257 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1258 if (len > maxaddlen) maxaddlen = len;
1259 }
1260 for (h = addr->host_list; h != NULL; h = h->next)
1261 {
1262 int len = Ustrlen(h->name);
1263 fprintf(f, " host %s ", h->name);
1264 while (len++ < maxlen) fprintf(f, " ");
1265 if (h->address != NULL)
1266 {
1267 fprintf(f, "[%s] ", h->address);
1268 len = Ustrlen(h->address);
1269 }
1270 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1271 {
1272 fprintf(f, "[unknown] ");
1273 len = 7;
1274 }
1275 else len = -3;
1276 while (len++ < maxaddlen) fprintf(f," ");
1277 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1278 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1279 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1280 fprintf(f, "\n");
1281 }
1282 }
1283 }
1284 }
1285
2c7db3f5
PH
1286/* Will be DEFER or FAIL if any one address has, only for full_info (which is
1287the -bv or -bt case). */
1288
1289return yield;
059ec3d9
PH
1290}
1291
1292
1293
1294
1295/*************************************************
1296* Check headers for syntax errors *
1297*************************************************/
1298
1299/* This function checks those header lines that contain addresses, and verifies
1300that all the addresses therein are syntactially correct.
1301
1302Arguments:
1303 msgptr where to put an error message
1304
1305Returns: OK
1306 FAIL
1307*/
1308
1309int
1310verify_check_headers(uschar **msgptr)
1311{
1312header_line *h;
1313uschar *colon, *s;
1314
1315for (h = header_list; h != NULL; h = h->next)
1316 {
1317 if (h->type != htype_from &&
1318 h->type != htype_reply_to &&
1319 h->type != htype_sender &&
1320 h->type != htype_to &&
1321 h->type != htype_cc &&
1322 h->type != htype_bcc)
1323 continue;
1324
1325 colon = Ustrchr(h->text, ':');
1326 s = colon + 1;
1327 while (isspace(*s)) s++;
1328
1329 parse_allow_group = TRUE; /* Allow group syntax */
1330
1331 /* Loop for multiple addresses in the header */
1332
1333 while (*s != 0)
1334 {
1335 uschar *ss = parse_find_address_end(s, FALSE);
1336 uschar *recipient, *errmess;
1337 int terminator = *ss;
1338 int start, end, domain;
1339
1340 /* Temporarily terminate the string at this point, and extract the
1341 operative address within. */
1342
1343 *ss = 0;
1344 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
1345 *ss = terminator;
1346
1347 /* Permit an unqualified address only if the message is local, or if the
1348 sending host is configured to be permitted to send them. */
1349
1350 if (recipient != NULL && domain == 0)
1351 {
1352 if (h->type == htype_from || h->type == htype_sender)
1353 {
1354 if (!allow_unqualified_sender) recipient = NULL;
1355 }
1356 else
1357 {
1358 if (!allow_unqualified_recipient) recipient = NULL;
1359 }
1360 if (recipient == NULL) errmess = US"unqualified address not permitted";
1361 }
1362
1363 /* It's an error if no address could be extracted, except for the special
1364 case of an empty address. */
1365
1366 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
1367 {
1368 uschar *verb = US"is";
1369 uschar *t = ss;
1370 int len;
1371
1372 /* Arrange not to include any white space at the end in the
1373 error message. */
1374
1375 while (t > s && isspace(t[-1])) t--;
1376
1377 /* Add the address which failed to the error message, since in a
1378 header with very many addresses it is sometimes hard to spot
1379 which one is at fault. However, limit the amount of address to
1380 quote - cases have been seen where, for example, a missing double
1381 quote in a humungous To: header creates an "address" that is longer
1382 than string_sprintf can handle. */
1383
1384 len = t - s;
1385 if (len > 1024)
1386 {
1387 len = 1024;
1388 verb = US"begins";
1389 }
1390
1391 *msgptr = string_printing(
1392 string_sprintf("%s: failing address in \"%.*s\" header %s: %.*s",
1393 errmess, colon - h->text, h->text, verb, len, s));
1394
1395 return FAIL;
1396 }
1397
1398 /* Advance to the next address */
1399
1400 s = ss + (terminator? 1:0);
1401 while (isspace(*s)) s++;
1402 } /* Next address */
1403 } /* Next header */
1404
1405return OK;
1406}
1407
1408
1409
1410
1411/*************************************************
1412* Find if verified sender *
1413*************************************************/
1414
1415/* Usually, just a single address is verified as the sender of the message.
1416However, Exim can be made to verify other addresses as well (often related in
1417some way), and this is useful in some environments. There may therefore be a
1418chain of such addresses that have previously been tested. This function finds
1419whether a given address is on the chain.
1420
1421Arguments: the address to be verified
1422Returns: pointer to an address item, or NULL
1423*/
1424
1425address_item *
1426verify_checked_sender(uschar *sender)
1427{
1428address_item *addr;
1429for (addr = sender_verified_list; addr != NULL; addr = addr->next)
1430 if (Ustrcmp(sender, addr->address) == 0) break;
1431return addr;
1432}
1433
1434
1435
1436
1437
1438/*************************************************
1439* Get valid header address *
1440*************************************************/
1441
1442/* Scan the originator headers of the message, looking for an address that
1443verifies successfully. RFC 822 says:
1444
1445 o The "Sender" field mailbox should be sent notices of
1446 any problems in transport or delivery of the original
1447 messages. If there is no "Sender" field, then the
1448 "From" field mailbox should be used.
1449
1450 o If the "Reply-To" field exists, then the reply should
1451 go to the addresses indicated in that field and not to
1452 the address(es) indicated in the "From" field.
1453
1454So we check a Sender field if there is one, else a Reply_to field, else a From
1455field. As some strange messages may have more than one of these fields,
1456especially if they are resent- fields, check all of them if there is more than
1457one.
1458
1459Arguments:
1460 user_msgptr points to where to put a user error message
1461 log_msgptr points to where to put a log error message
1462 callout timeout for callout check (passed to verify_address())
1463 callout_overall overall callout timeout (ditto)
4deaf07d 1464 callout_connect connect callout timeout (ditto)
059ec3d9
PH
1465 se_mailfrom mailfrom for verify; NULL => ""
1466 pm_mailfrom sender for pm callout check (passed to verify_address())
1467 options callout options (passed to verify_address())
fe5b5d0b 1468 verrno where to put the address basic_errno
059ec3d9
PH
1469
1470If log_msgptr is set to something without setting user_msgptr, the caller
1471normally uses log_msgptr for both things.
1472
1473Returns: result of the verification attempt: OK, FAIL, or DEFER;
1474 FAIL is given if no appropriate headers are found
1475*/
1476
1477int
1478verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
4deaf07d 1479 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
fe5b5d0b 1480 uschar *pm_mailfrom, int options, int *verrno)
059ec3d9
PH
1481{
1482static int header_types[] = { htype_sender, htype_reply_to, htype_from };
1483int yield = FAIL;
1484int i;
1485
1486for (i = 0; i < 3; i++)
1487 {
1488 header_line *h;
1489 for (h = header_list; h != NULL; h = h->next)
1490 {
1491 int terminator, new_ok;
1492 uschar *s, *ss, *endname;
1493
1494 if (h->type != header_types[i]) continue;
1495 s = endname = Ustrchr(h->text, ':') + 1;
1496
1497 while (*s != 0)
1498 {
1499 address_item *vaddr;
1500
1501 while (isspace(*s) || *s == ',') s++;
1502 if (*s == 0) break; /* End of header */
1503
1504 ss = parse_find_address_end(s, FALSE);
1505
1506 /* The terminator is a comma or end of header, but there may be white
1507 space preceding it (including newline for the last address). Move back
1508 past any white space so we can check against any cached envelope sender
1509 address verifications. */
1510
1511 while (isspace(ss[-1])) ss--;
1512 terminator = *ss;
1513 *ss = 0;
1514
1515 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
1516 (int)(endname - h->text), h->text, s);
1517
1518 /* See if we have already verified this address as an envelope sender,
1519 and if so, use the previous answer. */
1520
1521 vaddr = verify_checked_sender(s);
1522
1523 if (vaddr != NULL && /* Previously checked */
1524 (callout <= 0 || /* No callout needed; OR */
1525 vaddr->special_action > 256)) /* Callout was done */
1526 {
1527 new_ok = vaddr->special_action & 255;
1528 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
1529 *ss = terminator; /* Restore shortened string */
1530 }
1531
1532 /* Otherwise we run the verification now. We must restore the shortened
1533 string before running the verification, so the headers are correct, in
1534 case there is any rewriting. */
1535
1536 else
1537 {
1538 int start, end, domain;
1539 uschar *address = parse_extract_address(s, log_msgptr, &start,
1540 &end, &domain, FALSE);
1541
1542 *ss = terminator;
1543
1544 /* If verification failed because of a syntax error, fail this
1545 function, and ensure that the failing address gets added to the error
1546 message. */
1547
1548 if (address == NULL)
1549 {
1550 new_ok = FAIL;
1551 if (*log_msgptr != NULL)
1552 {
1553 while (ss > s && isspace(ss[-1])) ss--;
1554 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
1555 "scanning for sender: %s in \"%.*s\"",
1556 endname - h->text, h->text, *log_msgptr, ss - s, s);
1557 return FAIL;
1558 }
1559 }
1560
2f6603e1 1561 /* Else go ahead with the sender verification. But it isn't *the*
059ec3d9
PH
1562 sender of the message, so set vopt_fake_sender to stop sender_address
1563 being replaced after rewriting or qualification. */
1564
1565 else
1566 {
1567 vaddr = deliver_make_addr(address, FALSE);
1568 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
4deaf07d
PH
1569 callout, callout_overall, callout_connect, se_mailfrom,
1570 pm_mailfrom, NULL);
059ec3d9
PH
1571 }
1572 }
1573
1574 /* We now have the result, either newly found, or cached. If we are
1575 giving out error details, set a specific user error. This means that the
1576 last of these will be returned to the user if all three fail. We do not
1577 set a log message - the generic one below will be used. */
1578
fe5b5d0b 1579 if (new_ok != OK)
059ec3d9 1580 {
fe5b5d0b
PH
1581 *verrno = vaddr->basic_errno;
1582 if (smtp_return_error_details)
1583 {
1584 *user_msgptr = string_sprintf("Rejected after DATA: "
1585 "could not verify \"%.*s\" header address\n%s: %s",
1586 endname - h->text, h->text, vaddr->address, vaddr->message);
1587 }
1588 }
059ec3d9
PH
1589
1590 /* Success or defer */
1591
1592 if (new_ok == OK) return OK;
1593 if (new_ok == DEFER) yield = DEFER;
1594
1595 /* Move on to any more addresses in the header */
1596
1597 s = ss;
1598 }
1599 }
1600 }
1601
1602if (yield == FAIL && *log_msgptr == NULL)
1603 *log_msgptr = US"there is no valid sender in any header line";
1604
1605if (yield == DEFER && *log_msgptr == NULL)
1606 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
1607
1608return yield;
1609}
1610
1611
1612
1613
1614/*************************************************
1615* Get RFC 1413 identification *
1616*************************************************/
1617
1618/* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
1619the timeout is set to zero, then the query is not done. There may also be lists
1620of hosts and nets which are exempt. To guard against malefactors sending
1621non-printing characters which could, for example, disrupt a message's headers,
1622make sure the string consists of printing characters only.
1623
1624Argument:
1625 port the port to connect to; usually this is IDENT_PORT (113), but when
1626 running in the test harness with -bh a different value is used.
1627
1628Returns: nothing
1629
1630Side effect: any received ident value is put in sender_ident (NULL otherwise)
1631*/
1632
1633void
1634verify_get_ident(int port)
1635{
1636int sock, host_af, qlen;
1637int received_sender_port, received_interface_port, n;
1638uschar *p;
1639uschar buffer[2048];
1640
1641/* Default is no ident. Check whether we want to do an ident check for this
1642host. */
1643
1644sender_ident = NULL;
1645if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
1646 return;
1647
1648DEBUG(D_ident) debug_printf("doing ident callback\n");
1649
1650/* Set up a connection to the ident port of the remote host. Bind the local end
1651to the incoming interface address. If the sender host address is an IPv6
1652address, the incoming interface address will also be IPv6. */
1653
1654host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
1655sock = ip_socket(SOCK_STREAM, host_af);
1656if (sock < 0) return;
1657
1658if (ip_bind(sock, host_af, interface_address, 0) < 0)
1659 {
1660 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
1661 strerror(errno));
1662 goto END_OFF;
1663 }
1664
1665if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
1666 < 0)
1667 {
1668 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
1669 {
1670 log_write(0, LOG_MAIN, "ident connection to %s timed out",
1671 sender_host_address);
1672 }
1673 else
1674 {
1675 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
1676 sender_host_address, strerror(errno));
1677 }
1678 goto END_OFF;
1679 }
1680
1681/* Construct and send the query. */
1682
1683sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
1684qlen = Ustrlen(buffer);
1685if (send(sock, buffer, qlen, 0) < 0)
1686 {
1687 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
1688 goto END_OFF;
1689 }
1690
1691/* Read a response line. We put it into the rest of the buffer, using several
1692recv() calls if necessary. */
1693
1694p = buffer + qlen;
1695
1696for (;;)
1697 {
1698 uschar *pp;
1699 int count;
1700 int size = sizeof(buffer) - (p - buffer);
1701
1702 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
1703 count = ip_recv(sock, p, size, rfc1413_query_timeout);
1704 if (count <= 0) goto END_OFF; /* Read error or EOF */
1705
1706 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
1707 generous, and accept a plain \n terminator as well. The only illegal
1708 character is 0. */
1709
1710 for (pp = p; pp < p + count; pp++)
1711 {
1712 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
1713 if (*pp == '\n')
1714 {
1715 if (pp[-1] == '\r') pp--;
1716 *pp = 0;
1717 goto GOT_DATA; /* Break out of both loops */
1718 }
1719 }
1720
1721 /* Reached the end of the data without finding \n. Let the loop continue to
1722 read some more, if there is room. */
1723
1724 p = pp;
1725 }
1726
1727GOT_DATA:
1728
1729/* We have received a line of data. Check it carefully. It must start with the
1730same two port numbers that we sent, followed by data as defined by the RFC. For
1731example,
1732
1733 12345 , 25 : USERID : UNIX :root
1734
1735However, the amount of white space may be different to what we sent. In the
1736"osname" field there may be several sub-fields, comma separated. The data we
1737actually want to save follows the third colon. Some systems put leading spaces
1738in it - we discard those. */
1739
1740if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
1741 &received_interface_port, &n) != 2 ||
1742 received_sender_port != sender_host_port ||
1743 received_interface_port != interface_port)
1744 goto END_OFF;
1745
1746p = buffer + qlen + n;
1747while(isspace(*p)) p++;
1748if (*p++ != ':') goto END_OFF;
1749while(isspace(*p)) p++;
1750if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
1751p += 6;
1752while(isspace(*p)) p++;
1753if (*p++ != ':') goto END_OFF;
1754while (*p != 0 && *p != ':') p++;
1755if (*p++ == 0) goto END_OFF;
1756while(isspace(*p)) p++;
1757if (*p == 0) goto END_OFF;
1758
1759/* The rest of the line is the data we want. We turn it into printing
1760characters when we save it, so that it cannot mess up the format of any logging
1761or Received: lines into which it gets inserted. We keep a maximum of 127
1762characters. */
1763
1764sender_ident = string_printing(string_copyn(p, 127));
1765DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
1766
1767END_OFF:
1768close(sock);
1769return;
1770}
1771
1772
1773
1774
1775/*************************************************
1776* Match host to a single host-list item *
1777*************************************************/
1778
1779/* This function compares a host (name or address) against a single item
1780from a host list. The host name gets looked up if it is needed and is not
1781already known. The function is called from verify_check_this_host() via
1782match_check_list(), which is why most of its arguments are in a single block.
1783
1784Arguments:
1785 arg the argument block (see below)
1786 ss the host-list item
1787 valueptr where to pass back looked up data, or NULL
1788 error for error message when returning ERROR
1789
1790The block contains:
1791 host_name the host name or NULL, implying use sender_host_name and
1792 sender_host_aliases, looking them up if required
1793 host_address the host address
1794 host_ipv4 the IPv4 address taken from an IPv6 one
1795
1796Returns: OK matched
1797 FAIL did not match
1798 DEFER lookup deferred
1799 ERROR failed to find the host name or IP address
1800 unknown lookup type specified
1801*/
1802
1803static int
1804check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
1805{
1806check_host_block *cb = (check_host_block *)arg;
1807int maskoffset;
1808BOOL isquery = FALSE;
1809uschar *semicolon, *t;
1810uschar **aliases;
1811
1812/* Optimize for the special case when the pattern is "*". */
1813
1814if (*ss == '*' && ss[1] == 0) return OK;
1815
1816/* If the pattern is empty, it matches only in the case when there is no host -
1817this can occur in ACL checking for SMTP input using the -bs option. In this
1818situation, the host address is the empty string. */
1819
1820if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
1821if (*ss == 0) return FAIL;
1822
1823/* If the pattern is precisely "@" then match against the primary host name;
1824if it's "@[]" match against the local host's IP addresses. */
1825
1826if (*ss == '@')
1827 {
1828 if (ss[1] == 0) ss = primary_hostname;
1829 else if (Ustrcmp(ss, "@[]") == 0)
1830 {
1831 ip_address_item *ip;
1832 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
1833 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
1834 return FAIL;
1835 }
1836 }
1837
1838/* If the pattern is an IP address, optionally followed by a bitmask count, do
1839a (possibly masked) comparision with the current IP address. */
1840
a5a28604 1841if (string_is_ip_address(ss, &maskoffset) > 0)
059ec3d9
PH
1842 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
1843
1844/* If the item is of the form net[n]-lookup;<file|query> then it is a lookup on
1845a masked IP network, in textual form. The net- stuff really only applies to
1846single-key lookups where the key is implicit. For query-style lookups the key
1847is specified in the query. From release 4.30, the use of net- for query style
1848is no longer needed, but we retain it for backward compatibility. */
1849
1850if (Ustrncmp(ss, "net", 3) == 0 && (semicolon = Ustrchr(ss, ';')) != NULL)
1851 {
1852 int mlen = 0;
1853 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
1854 if (*t++ == '-')
1855 {
1856 int insize;
1857 int search_type;
1858 int incoming[4];
1859 void *handle;
1860 uschar *filename, *key, *result;
1861 uschar buffer[64];
1862
1863 /* If no mask was supplied, set a negative value */
1864
1865 if (mlen == 0 && t == ss+4) mlen = -1;
1866
1867 /* Find the search type */
1868
1869 search_type = search_findtype(t, semicolon - t);
1870
1871 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1872 search_error_message);
1873
1874 /* Adjust parameters for the type of lookup. For a query-style
1875 lookup, there is no file name, and the "key" is just the query. For
1876 a single-key lookup, the key is the current IP address, masked
6f0c9a4f
PH
1877 appropriately, and reconverted to text form, with the mask appended.
1878 For IPv6 addresses, specify dot separators instead of colons. */
059ec3d9
PH
1879
1880 if (mac_islookup(search_type, lookup_querystyle))
1881 {
1882 filename = NULL;
1883 key = semicolon + 1;
1884 }
1885 else
1886 {
1887 insize = host_aton(cb->host_address, incoming);
1888 host_mask(insize, incoming, mlen);
6f0c9a4f 1889 (void)host_nmtoa(insize, incoming, mlen, buffer, '.');
059ec3d9
PH
1890 key = buffer;
1891 filename = semicolon + 1;
1892 }
1893
1894 /* Now do the actual lookup; note that there is no search_close() because
1895 of the caching arrangements. */
1896
1897 handle = search_open(filename, search_type, 0, NULL, NULL);
1898 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1899 search_error_message);
1900 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
1901 if (valueptr != NULL) *valueptr = result;
1902 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
1903 }
1904 }
1905
1906/* The pattern is not an IP address or network reference of any kind. That is,
1907it is a host name pattern. Check the characters of the pattern to see if they
1908comprise only letters, digits, full stops, and hyphens (the constituents of
1909domain names). Allow underscores, as they are all too commonly found. Sigh.
1910Also, if allow_utf8_domains is set, allow top-bit characters. */
1911
1912for (t = ss; *t != 0; t++)
1913 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
1914 (!allow_utf8_domains || *t < 128)) break;
1915
1916/* If the pattern is a complete domain name, with no fancy characters, look up
1917its IP address and match against that. Note that a multi-homed host will add
1918items to the chain. */
1919
1920if (*t == 0)
1921 {
1922 int rc;
1923 host_item h;
1924 h.next = NULL;
1925 h.name = ss;
1926 h.address = NULL;
1927 h.mx = MX_NONE;
1928 rc = host_find_byname(&h, NULL, NULL, FALSE);
1929 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1930 {
1931 host_item *hh;
1932 for (hh = &h; hh != NULL; hh = hh->next)
1933 {
1934 if (Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)?
1935 cb->host_ipv4 : cb->host_address) == 0)
1936 return OK;
1937 }
1938 return FAIL;
1939 }
1940 if (rc == HOST_FIND_AGAIN) return DEFER;
1941 *error = string_sprintf("failed to find IP address for %s", ss);
1942 return ERROR;
1943 }
1944
1945/* Almost all subsequent comparisons require the host name, and can be done
1946using the general string matching function. When this function is called for
1947outgoing hosts, the name is always given explicitly. If it is NULL, it means we
1948must use sender_host_name and its aliases, looking them up if necessary. */
1949
1950if (cb->host_name != NULL) /* Explicit host name given */
1951 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
1952 valueptr);
1953
1954/* Host name not given; in principle we need the sender host name and its
1955aliases. However, for query-style lookups, we do not need the name if the
1956query does not contain $sender_host_name. From release 4.23, a reference to
1957$sender_host_name causes it to be looked up, so we don't need to do the lookup
1958on spec. */
1959
1960if ((semicolon = Ustrchr(ss, ';')) != NULL)
1961 {
1962 uschar *affix;
1963 int partial, affixlen, starflags, id;
1964
1965 *semicolon = 0;
1966 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
1967 *semicolon=';';
1968
1969 if (id < 0) /* Unknown lookup type */
1970 {
1971 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
1972 search_error_message, ss);
1973 return DEFER;
1974 }
1975 isquery = mac_islookup(id, lookup_querystyle);
1976 }
1977
1978if (isquery)
1979 {
1980 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
1981 {
1982 case OK: return OK;
1983 case DEFER: return DEFER;
1984 default: return FAIL;
1985 }
1986 }
1987
1988/* Not a query-style lookup; must ensure the host name is present, and then we
1989do a check on the name and all its aliases. */
1990
1991if (sender_host_name == NULL)
1992 {
1993 HDEBUG(D_host_lookup)
1994 debug_printf("sender host name required, to match against %s\n", ss);
1995 if (host_lookup_failed || host_name_lookup() != OK)
1996 {
1997 *error = string_sprintf("failed to find host name for %s",
1998 sender_host_address);;
1999 return ERROR;
2000 }
2001 host_build_sender_fullhost();
2002 }
2003
2004/* Match on the sender host name, using the general matching function */
2005
2006switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2007 valueptr))
2008 {
2009 case OK: return OK;
2010 case DEFER: return DEFER;
2011 }
2012
2013/* If there are aliases, try matching on them. */
2014
2015aliases = sender_host_aliases;
2016while (*aliases != NULL)
2017 {
2018 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2019 {
2020 case OK: return OK;
2021 case DEFER: return DEFER;
2022 }
2023 }
2024return FAIL;
2025}
2026
2027
2028
2029
2030/*************************************************
2031* Check a specific host matches a host list *
2032*************************************************/
2033
2034/* This function is passed a host list containing items in a number of
2035different formats and the identity of a host. Its job is to determine whether
2036the given host is in the set of hosts defined by the list. The host name is
2037passed as a pointer so that it can be looked up if needed and not already
2038known. This is commonly the case when called from verify_check_host() to check
2039an incoming connection. When called from elsewhere the host name should usually
2040be set.
2041
2042This function is now just a front end to match_check_list(), which runs common
2043code for scanning a list. We pass it the check_host() function to perform a
2044single test.
2045
2046Arguments:
2047 listptr pointer to the host list
2048 cache_bits pointer to cache for named lists, or NULL
2049 host_name the host name or NULL, implying use sender_host_name and
2050 sender_host_aliases, looking them up if required
2051 host_address the IP address
2052 valueptr if not NULL, data from a lookup is passed back here
2053
2054Returns: OK if the host is in the defined set
2055 FAIL if the host is not in the defined set,
2056 DEFER if a data lookup deferred (not a host lookup)
2057
2058If the host name was needed in order to make a comparison, and could not be
2059determined from the IP address, the result is FAIL unless the item
2060"+allow_unknown" was met earlier in the list, in which case OK is returned. */
2061
2062int
2063verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2064 uschar *host_name, uschar *host_address, uschar **valueptr)
2065{
d4eb88df 2066int rc;
059ec3d9 2067unsigned int *local_cache_bits = cache_bits;
d4eb88df 2068uschar *save_host_address = deliver_host_address;
059ec3d9
PH
2069check_host_block cb;
2070cb.host_name = host_name;
2071cb.host_address = host_address;
2072
2073if (valueptr != NULL) *valueptr = NULL;
2074
2075/* If the host address starts off ::ffff: it is an IPv6 address in
2076IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2077addresses. */
2078
2079cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2080 host_address + 7 : host_address;
2081
d4eb88df
PH
2082/* During the running of the check, put the IP address into $host_address. In
2083the case of calls from the smtp transport, it will already be there. However,
2084in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
2085the safe side, any existing setting is preserved, though as I write this
2086(November 2004) I can't see any cases where it is actually needed. */
2087
2088deliver_host_address = host_address;
2089rc = match_check_list(
2090 listptr, /* the list */
2091 0, /* separator character */
2092 &hostlist_anchor, /* anchor pointer */
2093 &local_cache_bits, /* cache pointer */
2094 check_host, /* function for testing */
2095 &cb, /* argument for function */
2096 MCL_HOST, /* type of check */
2097 (host_address == sender_host_address)?
2098 US"host" : host_address, /* text for debugging */
2099 valueptr); /* where to pass back data */
2100deliver_host_address = save_host_address;
2101return rc;
059ec3d9
PH
2102}
2103
2104
2105
2106
2107/*************************************************
2108* Check the remote host matches a list *
2109*************************************************/
2110
2111/* This is a front end to verify_check_this_host(), created because checking
2112the remote host is a common occurrence. With luck, a good compiler will spot
2113the tail recursion and optimize it. If there's no host address, this is
2114command-line SMTP input - check against an empty string for the address.
2115
2116Arguments:
2117 listptr pointer to the host list
2118
2119Returns: the yield of verify_check_this_host(),
2120 i.e. OK, FAIL, or DEFER
2121*/
2122
2123int
2124verify_check_host(uschar **listptr)
2125{
2126return verify_check_this_host(listptr, sender_host_cache, NULL,
2127 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
2128}
2129
2130
2131
2132
2133
2134/*************************************************
2135* Invert an IP address for a DNS black list *
2136*************************************************/
2137
2138/*
2139Arguments:
2140 buffer where to put the answer
2141 address the address to invert
2142*/
2143
2144static void
2145invert_address(uschar *buffer, uschar *address)
2146{
2147int bin[4];
2148uschar *bptr = buffer;
2149
2150/* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
2151to the IPv4 part only. */
2152
2153if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
2154
2155/* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
2156always 1. */
2157
2158if (host_aton(address, bin) == 1)
2159 {
2160 int i;
2161 int x = bin[0];
2162 for (i = 0; i < 4; i++)
2163 {
2164 sprintf(CS bptr, "%d.", x & 255);
2165 while (*bptr) bptr++;
2166 x >>= 8;
2167 }
2168 }
2169
2170/* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
2171in any DNS black lists, and the format in which they will be looked up is
2172unknown. This is just a guess. */
2173
2174#if HAVE_IPV6
2175else
2176 {
2177 int i, j;
2178 for (j = 3; j >= 0; j--)
2179 {
2180 int x = bin[j];
2181 for (i = 0; i < 8; i++)
2182 {
2183 sprintf(CS bptr, "%x.", x & 15);
2184 while (*bptr) bptr++;
2185 x >>= 4;
2186 }
2187 }
2188 }
2189#endif
2190}
2191
2192
2193
2194/*************************************************
0bcb2a0e
PH
2195* Perform a single dnsbl lookup *
2196*************************************************/
2197
2198/* This function is called from verify_check_dnsbl() below.
2199
2200Arguments:
2201 domain the outer dnsbl domain (for debug message)
2202 keydomain the current keydomain (for debug message)
2203 query the domain to be looked up
2204 iplist the list of matching IP addresses
2205 bitmask true if bitmask matching is wanted
2206 invert_result true if result to be inverted
2207 defer_return what to return for a defer
2208
2209Returns: OK if lookup succeeded
2210 FAIL if not
2211*/
2212
2213static int
2214one_check_dnsbl(uschar *domain, uschar *keydomain, uschar *query,
2215 uschar *iplist, BOOL bitmask, BOOL invert_result, int defer_return)
2216{
2217dns_answer dnsa;
2218dns_scan dnss;
2219tree_node *t;
2220dnsbl_cache_block *cb;
2221int old_pool = store_pool;
2222
2223/* Look for this query in the cache. */
2224
2225t = tree_search(dnsbl_cache, query);
2226
2227/* If not cached from a previous lookup, we must do a DNS lookup, and
2228cache the result in permanent memory. */
2229
2230if (t == NULL)
2231 {
2232 store_pool = POOL_PERM;
2233
2234 /* Set up a tree entry to cache the lookup */
2235
2236 t = store_get(sizeof(tree_node) + Ustrlen(query));
2237 Ustrcpy(t->name, query);
2238 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
2239 (void)tree_insertnode(&dnsbl_cache, t);
2240
2241 /* Do the DNS loopup . */
2242
2243 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
2244 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
2245 cb->text_set = FALSE;
2246 cb->text = NULL;
2247 cb->rhs = NULL;
2248
2249 /* If the lookup succeeded, cache the RHS address. The code allows for
2250 more than one address - this was for complete generality and the possible
2251 use of A6 records. However, A6 records have been reduced to experimental
2252 status (August 2001) and may die out. So they may never get used at all,
2253 let alone in dnsbl records. However, leave the code here, just in case.
2254
2255 Quite apart from one A6 RR generating multiple addresses, there are DNS
2256 lists that return more than one A record, so we must handle multiple
2257 addresses generated in that way as well. */
2258
2259 if (cb->rc == DNS_SUCCEED)
2260 {
2261 dns_record *rr;
2262 dns_address **addrp = &(cb->rhs);
2263 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2264 rr != NULL;
2265 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2266 {
2267 if (rr->type == T_A)
2268 {
2269 dns_address *da = dns_address_from_rr(&dnsa, rr);
2270 if (da != NULL)
2271 {
2272 *addrp = da;
2273 while (da->next != NULL) da = da->next;
2274 addrp = &(da->next);
2275 }
2276 }
2277 }
2278
2279 /* If we didn't find any A records, change the return code. This can
2280 happen when there is a CNAME record but there are no A records for what
2281 it points to. */
2282
2283 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
2284 }
2285
2286 store_pool = old_pool;
2287 }
2288
2289/* Previous lookup was cached */
2290
2291else
2292 {
2293 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
2294 cb = t->data.ptr;
2295 }
2296
2297/* We now have the result of the DNS lookup, either newly done, or cached
2298from a previous call. If the lookup succeeded, check against the address
2299list if there is one. This may be a positive equality list (introduced by
2300"="), a negative equality list (introduced by "!="), a positive bitmask
2301list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
2302
2303if (cb->rc == DNS_SUCCEED)
2304 {
2305 dns_address *da = NULL;
2306 uschar *addlist = cb->rhs->address;
2307
2308 /* For A and AAAA records, there may be multiple addresses from multiple
2309 records. For A6 records (currently not expected to be used) there may be
2310 multiple addresses from a single record. */
2311
2312 for (da = cb->rhs->next; da != NULL; da = da->next)
2313 addlist = string_sprintf("%s, %s", addlist, da->address);
2314
2315 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
2316 query, addlist);
2317
2318 /* Address list check; this can be either for equality, or via a bitmask.
2319 In the latter case, all the bits must match. */
2320
2321 if (iplist != NULL)
2322 {
2323 int ipsep = ',';
2324 uschar ip[46];
2325 uschar *ptr = iplist;
2326
2327 while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL)
2328 {
2329 /* Handle exact matching */
2330 if (!bitmask)
2331 {
2332 for (da = cb->rhs; da != NULL; da = da->next)
2333 {
2334 if (Ustrcmp(CS da->address, ip) == 0) break;
2335 }
2336 }
2337 /* Handle bitmask matching */
2338 else
2339 {
2340 int address[4];
2341 int mask = 0;
2342
2343 /* At present, all known DNS blocking lists use A records, with
2344 IPv4 addresses on the RHS encoding the information they return. I
2345 wonder if this will linger on as the last vestige of IPv4 when IPv6
2346 is ubiquitous? Anyway, for now we use paranoia code to completely
2347 ignore IPv6 addresses. The default mask is 0, which always matches.
2348 We change this only for IPv4 addresses in the list. */
2349
2350 if (host_aton(ip, address) == 1) mask = address[0];
2351
2352 /* Scan the returned addresses, skipping any that are IPv6 */
2353
2354 for (da = cb->rhs; da != NULL; da = da->next)
2355 {
2356 if (host_aton(da->address, address) != 1) continue;
2357 if ((address[0] & mask) == mask) break;
2358 }
2359 }
2360
2361 /* Break out if a match has been found */
2362
2363 if (da != NULL) break;
2364 }
2365
2366 /* If either
2367
2368 (a) No IP address in a positive list matched, or
2369 (b) An IP address in a negative list did match
2370
2371 then behave as if the DNSBL lookup had not succeeded, i.e. the host is
2372 not on the list. */
2373
2374 if (invert_result != (da == NULL))
2375 {
2376 HDEBUG(D_dnsbl)
2377 {
2378 debug_printf("=> but we are not accepting this block class because\n");
2379 debug_printf("=> there was %s match for %c%s\n",
2380 invert_result? "an exclude":"no", bitmask? '&' : '=', iplist);
2381 }
2382 return FAIL;
2383 }
2384 }
2385
2386 /* Either there was no IP list, or the record matched. Look up a TXT record
2387 if it hasn't previously been done. */
2388
2389 if (!cb->text_set)
2390 {
2391 cb->text_set = TRUE;
2392 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
2393 {
2394 dns_record *rr;
2395 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2396 rr != NULL;
2397 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2398 if (rr->type == T_TXT) break;
2399 if (rr != NULL)
2400 {
2401 int len = (rr->data)[0];
2402 if (len > 511) len = 127;
2403 store_pool = POOL_PERM;
2404 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
2405 store_pool = old_pool;
2406 }
2407 }
2408 }
2409
2410 dnslist_value = addlist;
2411 dnslist_text = cb->text;
2412 return OK;
2413 }
2414
2415/* There was a problem with the DNS lookup */
2416
2417if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
2418 {
2419 log_write(L_dnslist_defer, LOG_MAIN,
2420 "DNS list lookup defer (probably timeout) for %s: %s", query,
2421 (defer_return == OK)? US"assumed in list" :
2422 (defer_return == FAIL)? US"assumed not in list" :
2423 US"returned DEFER");
2424 return defer_return;
2425 }
2426
2427/* No entry was found in the DNS; continue for next domain */
2428
2429HDEBUG(D_dnsbl)
2430 {
2431 debug_printf("DNS lookup for %s failed\n", query);
2432 debug_printf("=> that means %s is not listed at %s\n",
2433 keydomain, domain);
2434 }
2435
2436return FAIL;
2437}
2438
2439
2440
2441
2442/*************************************************
059ec3d9
PH
2443* Check host against DNS black lists *
2444*************************************************/
2445
2446/* This function runs checks against a list of DNS black lists, until one
2447matches. Each item on the list can be of the form
2448
2449 domain=ip-address/key
2450
2451The domain is the right-most domain that is used for the query, for example,
2452blackholes.mail-abuse.org. If the IP address is present, there is a match only
2453if the DNS lookup returns a matching IP address. Several addresses may be
2454given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
2455
2456If no key is given, what is looked up in the domain is the inverted IP address
2457of the current client host. If a key is given, it is used to construct the
2458domain for the lookup. For example,
2459
2460 dsn.rfc-ignorant.org/$sender_address_domain
2461
2462After finding a match in the DNS, the domain is placed in $dnslist_domain, and
2463then we check for a TXT record for an error message, and if found, save its
2464value in $dnslist_text. We also cache everything in a tree, to optimize
2465multiple lookups.
2466
2467Note: an address for testing RBL is 192.203.178.39
2468Note: an address for testing DUL is 192.203.178.4
2469Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
2470
2471Arguments:
2472 listptr the domain/address/data list
2473
2474Returns: OK successful lookup (i.e. the address is on the list), or
2475 lookup deferred after +include_unknown
2476 FAIL name not found, or no data found for the given type, or
2477 lookup deferred after +exclude_unknown (default)
2478 DEFER lookup failure, if +defer_unknown was set
2479*/
2480
2481int
2482verify_check_dnsbl(uschar **listptr)
2483{
2484int sep = 0;
2485int defer_return = FAIL;
059ec3d9
PH
2486BOOL invert_result = FALSE;
2487uschar *list = *listptr;
2488uschar *domain;
2489uschar *s;
2490uschar buffer[1024];
2491uschar query[256]; /* DNS domain max length */
2492uschar revadd[128]; /* Long enough for IPv6 address */
2493
2494/* Indicate that the inverted IP address is not yet set up */
2495
2496revadd[0] = 0;
2497
0bcb2a0e
PH
2498/* In case this is the first time the DNS resolver is being used. */
2499
2500dns_init(FALSE, FALSE);
2501
059ec3d9
PH
2502/* Loop through all the domains supplied, until something matches */
2503
2504while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
2505 {
0bcb2a0e 2506 int rc;
059ec3d9
PH
2507 BOOL frc;
2508 BOOL bitmask = FALSE;
059ec3d9
PH
2509 uschar *iplist;
2510 uschar *key;
059ec3d9
PH
2511
2512 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
2513
2514 /* Deal with special values that change the behaviour on defer */
2515
2516 if (domain[0] == '+')
2517 {
2518 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
2519 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
2520 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
2521 else
2522 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
2523 domain);
2524 continue;
2525 }
2526
2527 /* See if there's explicit data to be looked up */
2528
2529 key = Ustrchr(domain, '/');
2530 if (key != NULL) *key++ = 0;
2531
2532 /* See if there's a list of addresses supplied after the domain name. This is
2533 introduced by an = or a & character; if preceded by ! we invert the result.
2534 */
2535
2536 iplist = Ustrchr(domain, '=');
2537 if (iplist == NULL)
2538 {
2539 bitmask = TRUE;
2540 iplist = Ustrchr(domain, '&');
2541 }
2542
2543 if (iplist != NULL)
2544 {
2545 if (iplist > domain && iplist[-1] == '!')
2546 {
2547 invert_result = TRUE;
2548 iplist[-1] = 0;
2549 }
2550 *iplist++ = 0;
2551 }
2552
2553 /* Check that what we have left is a sensible domain name. There is no reason
2554 why these domains should in fact use the same syntax as hosts and email
2555 domains, but in practice they seem to. However, there is little point in
2556 actually causing an error here, because that would no doubt hold up incoming
2557 mail. Instead, I'll just log it. */
2558
2559 for (s = domain; *s != 0; s++)
2560 {
2561 if (!isalnum(*s) && *s != '-' && *s != '.')
2562 {
2563 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
2564 "strange characters - is this right?", domain);
2565 break;
2566 }
2567 }
2568
0bcb2a0e
PH
2569 /* If there is no key string, construct the query by adding the domain name
2570 onto the inverted host address, and perform a single DNS lookup. */
2571
059ec3d9
PH
2572 if (key == NULL)
2573 {
2574 if (sender_host_address == NULL) return FAIL; /* can never match */
2575 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
2576 frc = string_format(query, sizeof(query), "%s%s", revadd, domain);
0bcb2a0e
PH
2577
2578 if (!frc)
059ec3d9 2579 {
0bcb2a0e
PH
2580 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2581 "(ignored): %s...", query);
2582 continue;
059ec3d9 2583 }
0bcb2a0e
PH
2584
2585 rc = one_check_dnsbl(domain, sender_host_address, query, iplist, bitmask,
2586 invert_result, defer_return);
2587
2588 if (rc == OK)
2589 {
2590 dnslist_domain = string_copy(domain);
2591 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
2592 sender_host_address, domain);
2593 }
2594
2595 if (rc != FAIL) return rc; /* OK or DEFER */
059ec3d9 2596 }
0bcb2a0e
PH
2597
2598 /* If there is a key string, it can be a list of domains or IP addresses to
2599 be concatenated with the main domain. */
2600
059ec3d9
PH
2601 else
2602 {
0bcb2a0e 2603 int keysep = 0;
c38d6da9 2604 BOOL defer = FALSE;
0bcb2a0e
PH
2605 uschar *keydomain;
2606 uschar keybuffer[256];
2607
2608 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
2609 sizeof(keybuffer))) != NULL)
2610 {
a5a28604 2611 if (string_is_ip_address(keydomain, NULL) > 0)
059ec3d9 2612 {
0bcb2a0e
PH
2613 uschar keyrevadd[128];
2614 invert_address(keyrevadd, keydomain);
2615 frc = string_format(query, sizeof(query), "%s%s", keyrevadd, domain);
2616 }
2617 else
2618 {
2619 frc = string_format(query, sizeof(query), "%s.%s", keydomain, domain);
059ec3d9
PH
2620 }
2621
0bcb2a0e 2622 if (!frc)
059ec3d9 2623 {
0bcb2a0e
PH
2624 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2625 "(ignored): %s...", query);
2626 continue;
059ec3d9 2627 }
0bcb2a0e
PH
2628
2629 rc = one_check_dnsbl(domain, keydomain, query, iplist, bitmask,
2630 invert_result, defer_return);
2631
2632 if (rc == OK)
059ec3d9 2633 {
0bcb2a0e
PH
2634 dnslist_domain = string_copy(domain);
2635 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
2636 keydomain, domain);
c38d6da9 2637 return OK;
059ec3d9 2638 }
0bcb2a0e 2639
c38d6da9
PH
2640 /* If the lookup deferred, remember this fact. We keep trying the rest
2641 of the list to see if we get a useful result, and if we don't, we return
2642 DEFER at the end. */
059ec3d9 2643
c38d6da9 2644 if (rc == DEFER) defer = TRUE;
0bcb2a0e 2645 } /* continue with next keystring domain/address */
c38d6da9
PH
2646
2647 if (defer) return DEFER;
0bcb2a0e
PH
2648 }
2649 } /* continue with next dnsdb outer domain */
059ec3d9
PH
2650
2651return FAIL;
2652}
2653
2654/* End of verify.c */