Pay attention to local part prefixes and suffixes when doing callouts.
[exim.git] / src / src / verify.c
CommitLineData
c688b954 1/* $Cambridge: exim/src/src/verify.c,v 1.16 2005/04/06 16:26:42 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,
8e669ac1 142 int callout, int callout_overall, int callout_connect, int options,
4deaf07d 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;
8e669ac1 154uschar **failure_ptr = is_recipient?
2c7db3f5 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;
8e669ac1 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;
8e669ac1 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";
8e669ac1 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;
8e669ac1 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 {
8e669ac1 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",
c688b954
PH
553 transport_rcpt_address(addr,
554 addr->transport->rcpt_include_affixes)) >= 0 &&
059ec3d9
PH
555 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
556 '2', callout);
557
558 if (done)
559 new_address_record.result = ccache_accept;
560 else if (errno == 0 && responsebuffer[0] == '5')
2c7db3f5 561 {
8e669ac1 562 *failure_ptr = US"recipient";
059ec3d9 563 new_address_record.result = ccache_reject;
8e669ac1 564 }
059ec3d9
PH
565
566 /* Do postmaster check if requested */
567
568 if (done && pm_mailfrom != NULL)
569 {
570 done =
571 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
572 smtp_read_response(&inblock, responsebuffer,
573 sizeof(responsebuffer), '2', callout) &&
574
575 smtp_write_command(&outblock, FALSE,
576 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
577 smtp_read_response(&inblock, responsebuffer,
578 sizeof(responsebuffer), '2', callout) &&
579
580 smtp_write_command(&outblock, FALSE,
581 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
582 smtp_read_response(&inblock, responsebuffer,
583 sizeof(responsebuffer), '2', callout);
584
585 new_domain_record.postmaster_stamp = time(NULL);
586
587 if (done)
588 new_domain_record.postmaster_result = ccache_accept;
589 else if (errno == 0 && responsebuffer[0] == '5')
590 {
8e669ac1 591 *failure_ptr = US"postmaster";
059ec3d9
PH
592 setflag(addr, af_verify_pmfail);
593 new_domain_record.postmaster_result = ccache_reject;
594 }
595 }
596 } /* Random not accepted */
597 } /* MAIL FROM:<> accepted */
598
599 /* For any failure of the main check, other than a negative response, we just
600 close the connection and carry on. We can identify a negative response by the
601 fact that errno is zero. For I/O errors it will be non-zero
602
603 Set up different error texts for logging and for sending back to the caller
604 as an SMTP response. Log in all cases, using a one-line format. For sender
605 callouts, give a full response to the caller, but for recipient callouts,
606 don't give the IP address because this may be an internal host whose identity
607 is not to be widely broadcast. */
608
609 if (!done)
610 {
611 if (errno == ETIMEDOUT)
612 {
613 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
8e669ac1 614 send_quit = FALSE;
059ec3d9
PH
615 }
616 else if (errno == 0)
617 {
618 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
619
620 addr->message =
621 string_sprintf("response to \"%s\" from %s [%s] was: %s",
622 big_buffer, host->name, host->address,
623 string_printing(responsebuffer));
624
625 addr->user_message = is_recipient?
626 string_sprintf("Callout verification failed:\n%s", responsebuffer)
627 :
628 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
629 host->address, big_buffer, responsebuffer);
630
631 /* Hard rejection ends the process */
632
633 if (responsebuffer[0] == '5') /* Address rejected */
634 {
635 yield = FAIL;
636 done = TRUE;
637 }
638 }
639 }
640
641 /* End the SMTP conversation and close the connection. */
642
c9bdd01c 643 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
059ec3d9
PH
644 close(inblock.sock);
645 } /* Loop through all hosts, while !done */
646
647/* If we get here with done == TRUE, a successful callout happened, and yield
648will be set OK or FAIL according to the response to the RCPT command.
649Otherwise, we looped through the hosts but couldn't complete the business.
650However, there may be domain-specific information to cache in both cases.
651
652The value of the result field in the new_domain record is ccache_unknown if
653there was an error before or with MAIL FROM:<>, and errno was not zero,
654implying some kind of I/O error. We don't want to write the cache in that case.
655Otherwise the value is ccache_accept or ccache_reject. */
656
657if (!callout_no_cache && new_domain_record.result != ccache_unknown)
658 {
659 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
660 == NULL)
661 {
662 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
663 }
664 else
665 {
666 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
667 (int)sizeof(dbdata_callout_cache));
668 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
669 " result=%d postmaster=%d random=%d\n",
670 new_domain_record.result,
671 new_domain_record.postmaster_result,
672 new_domain_record.random_result);
673 }
674 }
675
676/* If a definite result was obtained for the callout, cache it unless caching
677is disabled. */
678
679if (done)
680 {
681 if (!callout_no_cache && new_address_record.result != ccache_unknown)
682 {
683 if (dbm_file == NULL)
684 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
685 if (dbm_file == NULL)
686 {
687 HDEBUG(D_verify) debug_printf("no callout cache available\n");
688 }
689 else
690 {
691 (void)dbfn_write(dbm_file, address_key, &new_address_record,
692 (int)sizeof(dbdata_callout_cache_address));
693 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
694 (new_address_record.result == ccache_accept)? "positive" : "negative");
695 }
696 }
697 } /* done */
698
699/* Failure to connect to any host, or any response other than 2xx or 5xx is a
700temporary error. If there was only one host, and a response was received, leave
701it alone if supplying details. Otherwise, give a generic response. */
702
703else /* !done */
704 {
705 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
706 is_recipient? "recipient" : "sender");
707 yield = DEFER;
708
709 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
710
711 addr->user_message = (!smtp_return_error_details)? dullmsg :
712 string_sprintf("%s for <%s>.\n"
713 "The mail server(s) for the domain may be temporarily unreachable, or\n"
714 "they may be permanently unreachable from this server. In the latter case,\n%s",
715 dullmsg, addr->address,
716 is_recipient?
717 "the address will never be accepted."
718 :
719 "you need to change the address or create an MX record for its domain\n"
720 "if it is supposed to be generally accessible from the Internet.\n"
721 "Talk to your mail administrator for details.");
722
723 /* Force a specific error code */
724
725 addr->basic_errno = ERRNO_CALLOUTDEFER;
726 }
727
728/* Come here from within the cache-reading code on fast-track exit. */
729
730END_CALLOUT:
731if (dbm_file != NULL) dbfn_close(dbm_file);
732return yield;
733}
734
735
736
737/*************************************************
738* Copy error to toplevel address *
739*************************************************/
740
741/* This function is used when a verify fails or defers, to ensure that the
742failure or defer information is in the original toplevel address. This applies
743when an address is redirected to a single new address, and the failure or
744deferral happens to the child address.
745
746Arguments:
747 vaddr the verify address item
748 addr the final address item
749 yield FAIL or DEFER
750
751Returns: the value of YIELD
752*/
753
754static int
755copy_error(address_item *vaddr, address_item *addr, int yield)
756{
757if (addr != vaddr)
758 {
759 vaddr->message = addr->message;
760 vaddr->user_message = addr->user_message;
761 vaddr->basic_errno = addr->basic_errno;
762 vaddr->more_errno = addr->more_errno;
763 }
764return yield;
765}
766
767
768
769
770/*************************************************
771* Verify an email address *
772*************************************************/
773
774/* This function is used both for verification (-bv and at other times) and
775address testing (-bt), which is indicated by address_test_mode being set.
776
777Arguments:
778 vaddr contains the address to verify; the next field in this block
779 must be NULL
780 f if not NULL, write the result to this file
781 options various option bits:
782 vopt_fake_sender => this sender verify is not for the real
783 sender (it was verify=sender=xxxx or an address from a
784 header line) - rewriting must not change sender_address
785 vopt_is_recipient => this is a recipient address, otherwise
786 it's a sender address - this affects qualification and
787 rewriting and messages from callouts
788 vopt_qualify => qualify an unqualified address; else error
789 vopt_expn => called from SMTP EXPN command
790
791 These ones are used by do_callout() -- the options variable
792 is passed to it.
793
794 vopt_callout_no_cache => don't use callout cache
795 vopt_callout_random => do the "random" thing
796 vopt_callout_recipsender => use real sender for recipient
797 vopt_callout_recippmaster => use postmaster for recipient
798
799 callout if > 0, specifies that callout is required, and gives timeout
4deaf07d 800 for individual commands
059ec3d9
PH
801 callout_overall if > 0, gives overall timeout for the callout function;
802 if < 0, a default is used (see do_callout())
8e669ac1 803 callout_connect the connection timeout for callouts
059ec3d9
PH
804 se_mailfrom when callout is requested to verify a sender, use this
805 in MAIL FROM; NULL => ""
806 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
807 thing and use this as the sender address (may be "")
808
809 routed if not NULL, set TRUE if routing succeeded, so we can
810 distinguish between routing failed and callout failed
811
812Returns: OK address verified
813 FAIL address failed to verify
814 DEFER can't tell at present
815*/
816
817int
818verify_address(address_item *vaddr, FILE *f, int options, int callout,
8e669ac1 819 int callout_overall, int callout_connect, uschar *se_mailfrom,
4deaf07d 820 uschar *pm_mailfrom, BOOL *routed)
059ec3d9
PH
821{
822BOOL allok = TRUE;
823BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
824BOOL is_recipient = (options & vopt_is_recipient) != 0;
825BOOL expn = (options & vopt_expn) != 0;
059ec3d9
PH
826int i;
827int yield = OK;
828int verify_type = expn? v_expn :
829 address_test_mode? v_none :
830 is_recipient? v_recipient : v_sender;
831address_item *addr_list;
832address_item *addr_new = NULL;
833address_item *addr_remote = NULL;
834address_item *addr_local = NULL;
835address_item *addr_succeed = NULL;
8e669ac1 836uschar **failure_ptr = is_recipient?
2c7db3f5 837 &recipient_verify_failure : &sender_verify_failure;
059ec3d9
PH
838uschar *ko_prefix, *cr;
839uschar *address = vaddr->address;
840uschar *save_sender;
841uschar null_sender[] = { 0 }; /* Ensure writeable memory */
842
2c7db3f5
PH
843/* Clear, just in case */
844
845*failure_ptr = NULL;
846
059ec3d9
PH
847/* Set up a prefix and suffix for error message which allow us to use the same
848output statements both in EXPN mode (where an SMTP response is needed) and when
849debugging with an output file. */
850
851if (expn)
852 {
853 ko_prefix = US"553 ";
854 cr = US"\r";
855 }
856else ko_prefix = cr = US"";
857
858/* Add qualify domain if permitted; otherwise an unqualified address fails. */
859
860if (parse_find_at(address) == NULL)
861 {
862 if ((options & vopt_qualify) == 0)
863 {
864 if (f != NULL)
865 fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address,
866 cr);
8e669ac1 867 *failure_ptr = US"qualify";
059ec3d9
PH
868 return FAIL;
869 }
870 address = rewrite_address_qualify(address, is_recipient);
871 }
872
873DEBUG(D_verify)
874 {
875 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
876 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
877 }
878
879/* Rewrite and report on it. Clear the domain and local part caches - these
880may have been set by domains and local part tests during an ACL. */
881
882if (global_rewrite_rules != NULL)
883 {
884 uschar *old = address;
885 address = rewrite_address(address, is_recipient, FALSE,
886 global_rewrite_rules, rewrite_existflags);
887 if (address != old)
888 {
889 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
890 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
891 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
892 }
893 }
894
895/* If this is the real sender address, we must update sender_address at
896this point, because it may be referred to in the routers. */
897
898if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
899 sender_address = address;
900
901/* If the address was rewritten to <> no verification can be done, and we have
902to return OK. This rewriting is permitted only for sender addresses; for other
903addresses, such rewriting fails. */
904
905if (address[0] == 0) return OK;
906
907/* Save a copy of the sender address for re-instating if we change it to <>
908while verifying a sender address (a nice bit of self-reference there). */
909
910save_sender = sender_address;
911
912/* Update the address structure with the possibly qualified and rewritten
913address. Set it up as the starting address on the chain of new addresses. */
914
915vaddr->address = address;
916addr_new = vaddr;
917
918/* We need a loop, because an address can generate new addresses. We must also
919cope with generated pipes and files at the top level. (See also the code and
920comment in deliver.c.) However, it is usually the case that the router for
921user's .forward files has its verify flag turned off.
922
923If an address generates more than one child, the loop is used only when
924full_info is set, and this can only be set locally. Remote enquiries just get
925information about the top level address, not anything that it generated. */
926
927while (addr_new != NULL)
928 {
929 int rc;
930 address_item *addr = addr_new;
931
932 addr_new = addr->next;
933 addr->next = NULL;
934
935 DEBUG(D_verify)
936 {
937 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
938 debug_printf("Considering %s\n", addr->address);
939 }
940
941 /* Handle generated pipe, file or reply addresses. We don't get these
942 when handling EXPN, as it does only one level of expansion. */
943
944 if (testflag(addr, af_pfr))
945 {
946 allok = FALSE;
947 if (f != NULL)
948 {
949 BOOL allow;
950
951 if (addr->address[0] == '>')
952 {
953 allow = testflag(addr, af_allow_reply);
954 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
955 }
956 else
957 {
958 allow = (addr->address[0] == '|')?
959 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
960 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
961 }
962
963 if (addr->basic_errno == ERRNO_BADTRANSPORT)
964 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
965 "%s\n", addr->message);
966 else if (allow)
967 fprintf(f, "\n transport = %s\n", addr->transport->name);
968 else
969 fprintf(f, " *** forbidden ***\n");
970 }
971 continue;
972 }
973
974 /* Just in case some router parameter refers to it. */
975
976 return_path = (addr->p.errors_address != NULL)?
977 addr->p.errors_address : sender_address;
978
979 /* Split the address into domain and local part, handling the %-hack if
980 necessary, and then route it. While routing a sender address, set
981 $sender_address to <> because that is what it will be if we were trying to
982 send a bounce to the sender. */
983
984 if (routed != NULL) *routed = FALSE;
985 if ((rc = deliver_split_address(addr)) == OK)
986 {
987 if (!is_recipient) sender_address = null_sender;
988 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
989 &addr_succeed, verify_type);
990 sender_address = save_sender; /* Put back the real sender */
991 }
992
993 /* If routing an address succeeded, set the flag that remembers, for use when
994 an ACL cached a sender verify (in case a callout fails). Then if routing set
995 up a list of hosts or the transport has a host list, and the callout option
996 is set, and we aren't in a host checking run, do the callout verification,
997 and set another flag that notes that a callout happened. */
998
999 if (rc == OK)
1000 {
1001 if (routed != NULL) *routed = TRUE;
1002 if (callout > 0)
1003 {
1004 host_item *host_list = addr->host_list;
1005
1006 /* Default, if no remote transport, to NULL for the interface (=> any),
1007 "smtp" for the port, and "smtp" for the protocol. */
1008
1009 transport_feedback tf = { NULL, US"smtp", US"smtp", NULL, FALSE, FALSE };
1010
1011 /* If verification yielded a remote transport, we want to use that
1012 transport's options, so as to mimic what would happen if we were really
1013 sending a message to this address. */
1014
1015 if (addr->transport != NULL && !addr->transport->info->local)
1016 {
1017 (void)(addr->transport->setup)(addr->transport, addr, &tf, NULL);
1018
1019 /* If the transport has hosts and the router does not, or if the
1020 transport is configured to override the router's hosts, we must build a
1021 host list of the transport's hosts, and find the IP addresses */
1022
1023 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1024 {
1025 uschar *s;
1026
1027 host_list = NULL; /* Ignore the router's hosts */
1028
1029 deliver_domain = addr->domain;
1030 deliver_localpart = addr->local_part;
1031 s = expand_string(tf.hosts);
1032 deliver_domain = deliver_localpart = NULL;
1033
1034 if (s == NULL)
1035 {
1036 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1037 "\"%s\" in %s transport for callout: %s", tf.hosts,
1038 addr->transport->name, expand_string_message);
1039 }
1040 else
1041 {
1042 uschar *canonical_name;
d8ef3577 1043 host_item *host, *nexthost;
059ec3d9
PH
1044 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1045
1046 /* Just ignore failures to find a host address. If we don't manage
8e669ac1
PH
1047 to find any addresses, the callout will defer. Note that more than
1048 one address may be found for a single host, which will result in
1049 additional host items being inserted into the chain. Hence we must
d8ef3577 1050 save the next host first. */
059ec3d9 1051
d8ef3577 1052 for (host = host_list; host != NULL; host = nexthost)
059ec3d9 1053 {
d8ef3577 1054 nexthost = host->next;
8e669ac1 1055 if (tf.gethostbyname ||
a5a28604 1056 string_is_ip_address(host->name, NULL) > 0)
059ec3d9
PH
1057 (void)host_find_byname(host, NULL, &canonical_name, TRUE);
1058 else
1059 {
1060 int flags = HOST_FIND_BY_A;
1061 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1062 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1063 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1064 &canonical_name, NULL);
1065 }
1066 }
1067 }
1068 }
1069 }
1070
8e669ac1 1071 /* Can only do a callout if we have at least one host! If the callout
2c7db3f5 1072 fails, it will have set ${sender,recipient}_verify_failure. */
059ec3d9
PH
1073
1074 if (host_list != NULL)
1075 {
1076 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1077 if (host_checking && !host_checking_callout)
1078 {
1079 HDEBUG(D_verify)
1080 debug_printf("... callout omitted by default when host testing\n"
1081 "(Use -bhc if you want the callouts to happen.)\n");
1082 }
1083 else
1084 {
1085 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
4deaf07d 1086 callout_connect, options, se_mailfrom, pm_mailfrom);
059ec3d9
PH
1087 }
1088 }
1089 else
1090 {
1091 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1092 "transport provided a host list\n");
1093 }
1094 }
1095 }
8e669ac1 1096
2c7db3f5 1097 /* Otherwise, any failure is a routing failure */
8e669ac1
PH
1098
1099 else *failure_ptr = US"route";
059ec3d9
PH
1100
1101 /* A router may return REROUTED if it has set up a child address as a result
1102 of a change of domain name (typically from widening). In this case we always
1103 want to continue to verify the new child. */
1104
1105 if (rc == REROUTED) continue;
8e669ac1 1106
059ec3d9
PH
1107 /* Handle hard failures */
1108
1109 if (rc == FAIL)
1110 {
1111 allok = FALSE;
1112 if (f != NULL)
1113 {
1114 fprintf(f, "%s%s %s", ko_prefix, address,
1115 address_test_mode? "is undeliverable" : "failed to verify");
1116 if (!expn && admin_user)
1117 {
1118 if (addr->basic_errno > 0)
1119 fprintf(f, ": %s", strerror(addr->basic_errno));
1120 if (addr->message != NULL)
1121 fprintf(f, ":\n %s", addr->message);
1122 }
1123 fprintf(f, "%s\n", cr);
1124 }
1125
1126 if (!full_info) return copy_error(vaddr, addr, FAIL);
1127 else yield = FAIL;
1128 }
1129
1130 /* Soft failure */
1131
1132 else if (rc == DEFER)
1133 {
1134 allok = FALSE;
1135 if (f != NULL)
1136 {
1137 fprintf(f, "%s%s cannot be resolved at this time", ko_prefix, address);
1138 if (!expn && admin_user)
1139 {
1140 if (addr->basic_errno > 0)
1141 fprintf(f, ":\n %s", strerror(addr->basic_errno));
1142 if (addr->message != NULL)
1143 fprintf(f, ":\n %s", addr->message);
1144 else if (addr->basic_errno <= 0)
1145 fprintf(f, ":\n unknown error");
1146 }
1147
1148 fprintf(f, "%s\n", cr);
1149 }
1150 if (!full_info) return copy_error(vaddr, addr, DEFER);
1151 else if (yield == OK) yield = DEFER;
1152 }
1153
1154 /* If we are handling EXPN, we do not want to continue to route beyond
1155 the top level. */
1156
1157 else if (expn)
1158 {
1159 uschar *ok_prefix = US"250-";
1160 if (addr_new == NULL)
1161 {
1162 if (addr_local == NULL && addr_remote == NULL)
1163 fprintf(f, "250 mail to <%s> is discarded\r\n", address);
1164 else
1165 fprintf(f, "250 <%s>\r\n", address);
1166 }
1167 else while (addr_new != NULL)
1168 {
1169 address_item *addr2 = addr_new;
1170 addr_new = addr2->next;
1171 if (addr_new == NULL) ok_prefix = US"250 ";
1172 fprintf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1173 }
1174 return OK;
1175 }
1176
1177 /* Successful routing other than EXPN. */
1178
1179 else
1180 {
1181 /* Handle successful routing when short info wanted. Otherwise continue for
1182 other (generated) addresses. Short info is the operational case. Full info
1183 can be requested only when debug_selector != 0 and a file is supplied.
1184
1185 There is a conflict between the use of aliasing as an alternate email
1186 address, and as a sort of mailing list. If an alias turns the incoming
1187 address into just one address (e.g. J.Caesar->jc44) you may well want to
1188 carry on verifying the generated address to ensure it is valid when
1189 checking incoming mail. If aliasing generates multiple addresses, you
1190 probably don't want to do this. Exim therefore treats the generation of
1191 just a single new address as a special case, and continues on to verify the
1192 generated address. */
1193
1194 if (!full_info && /* Stop if short info wanted AND */
1195 (addr_new == NULL || /* No new address OR */
1196 addr_new->next != NULL || /* More than one new address OR */
1197 testflag(addr_new, af_pfr))) /* New address is pfr */
1198 {
1199 if (f != NULL) fprintf(f, "%s %s\n", address,
1200 address_test_mode? "is deliverable" : "verified");
1201
1202 /* If we have carried on to verify a child address, we want the value
1203 of $address_data to be that of the child */
1204
1205 vaddr->p.address_data = addr->p.address_data;
1206 return OK;
1207 }
1208 }
1209 } /* Loop for generated addresses */
1210
1211/* Display the full results of the successful routing, including any generated
1212addresses. Control gets here only when full_info is set, which requires f not
1213to be NULL, and this occurs only when a top-level verify is called with the
1214debugging switch on.
1215
1216If there are no local and no remote addresses, and there were no pipes, files,
1217or autoreplies, and there were no errors or deferments, the message is to be
1218discarded, usually because of the use of :blackhole: in an alias file. */
1219
1220if (allok && addr_local == NULL && addr_remote == NULL)
1221 fprintf(f, "mail to %s is discarded\n", address);
1222
1223else for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1224 {
1225 while (addr_list != NULL)
1226 {
1227 address_item *addr = addr_list;
1228 address_item *p = addr->parent;
1229 addr_list = addr->next;
1230
1231 fprintf(f, "%s", CS addr->address);
1232 while (p != NULL)
1233 {
1234 fprintf(f, "\n <-- %s", p->address);
1235 p = p->parent;
1236 }
1237 fprintf(f, "\n ");
1238
1239 /* Show router, and transport */
1240
1241 fprintf(f, "router = %s, ", addr->router->name);
1242 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1243 addr->transport->name);
1244
1245 /* Show any hosts that are set up by a router unless the transport
1246 is going to override them; fiddle a bit to get a nice format. */
1247
1248 if (addr->host_list != NULL && addr->transport != NULL &&
1249 !addr->transport->overrides_hosts)
1250 {
1251 host_item *h;
1252 int maxlen = 0;
1253 int maxaddlen = 0;
1254 for (h = addr->host_list; h != NULL; h = h->next)
1255 {
1256 int len = Ustrlen(h->name);
1257 if (len > maxlen) maxlen = len;
1258 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1259 if (len > maxaddlen) maxaddlen = len;
1260 }
1261 for (h = addr->host_list; h != NULL; h = h->next)
1262 {
1263 int len = Ustrlen(h->name);
1264 fprintf(f, " host %s ", h->name);
1265 while (len++ < maxlen) fprintf(f, " ");
1266 if (h->address != NULL)
1267 {
1268 fprintf(f, "[%s] ", h->address);
1269 len = Ustrlen(h->address);
1270 }
1271 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1272 {
1273 fprintf(f, "[unknown] ");
1274 len = 7;
1275 }
1276 else len = -3;
1277 while (len++ < maxaddlen) fprintf(f," ");
1278 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1279 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1280 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1281 fprintf(f, "\n");
1282 }
1283 }
1284 }
1285 }
1286
8e669ac1 1287/* Will be DEFER or FAIL if any one address has, only for full_info (which is
2c7db3f5
PH
1288the -bv or -bt case). */
1289
8e669ac1 1290return yield;
059ec3d9
PH
1291}
1292
1293
1294
1295
1296/*************************************************
1297* Check headers for syntax errors *
1298*************************************************/
1299
1300/* This function checks those header lines that contain addresses, and verifies
1301that all the addresses therein are syntactially correct.
1302
1303Arguments:
1304 msgptr where to put an error message
1305
1306Returns: OK
1307 FAIL
1308*/
1309
1310int
1311verify_check_headers(uschar **msgptr)
1312{
1313header_line *h;
1314uschar *colon, *s;
1315
1316for (h = header_list; h != NULL; h = h->next)
1317 {
1318 if (h->type != htype_from &&
1319 h->type != htype_reply_to &&
1320 h->type != htype_sender &&
1321 h->type != htype_to &&
1322 h->type != htype_cc &&
1323 h->type != htype_bcc)
1324 continue;
1325
1326 colon = Ustrchr(h->text, ':');
1327 s = colon + 1;
1328 while (isspace(*s)) s++;
1329
1330 parse_allow_group = TRUE; /* Allow group syntax */
1331
1332 /* Loop for multiple addresses in the header */
1333
1334 while (*s != 0)
1335 {
1336 uschar *ss = parse_find_address_end(s, FALSE);
1337 uschar *recipient, *errmess;
1338 int terminator = *ss;
1339 int start, end, domain;
1340
1341 /* Temporarily terminate the string at this point, and extract the
1342 operative address within. */
1343
1344 *ss = 0;
1345 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
1346 *ss = terminator;
1347
1348 /* Permit an unqualified address only if the message is local, or if the
1349 sending host is configured to be permitted to send them. */
1350
1351 if (recipient != NULL && domain == 0)
1352 {
1353 if (h->type == htype_from || h->type == htype_sender)
1354 {
1355 if (!allow_unqualified_sender) recipient = NULL;
1356 }
1357 else
1358 {
1359 if (!allow_unqualified_recipient) recipient = NULL;
1360 }
1361 if (recipient == NULL) errmess = US"unqualified address not permitted";
1362 }
1363
1364 /* It's an error if no address could be extracted, except for the special
1365 case of an empty address. */
1366
1367 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
1368 {
1369 uschar *verb = US"is";
1370 uschar *t = ss;
1371 int len;
1372
1373 /* Arrange not to include any white space at the end in the
1374 error message. */
1375
1376 while (t > s && isspace(t[-1])) t--;
1377
1378 /* Add the address which failed to the error message, since in a
1379 header with very many addresses it is sometimes hard to spot
1380 which one is at fault. However, limit the amount of address to
1381 quote - cases have been seen where, for example, a missing double
1382 quote in a humungous To: header creates an "address" that is longer
1383 than string_sprintf can handle. */
1384
1385 len = t - s;
1386 if (len > 1024)
1387 {
1388 len = 1024;
1389 verb = US"begins";
1390 }
1391
1392 *msgptr = string_printing(
1393 string_sprintf("%s: failing address in \"%.*s\" header %s: %.*s",
1394 errmess, colon - h->text, h->text, verb, len, s));
1395
1396 return FAIL;
1397 }
1398
1399 /* Advance to the next address */
1400
1401 s = ss + (terminator? 1:0);
1402 while (isspace(*s)) s++;
1403 } /* Next address */
1404 } /* Next header */
1405
1406return OK;
1407}
1408
1409
1410
1411
1412/*************************************************
1413* Find if verified sender *
1414*************************************************/
1415
1416/* Usually, just a single address is verified as the sender of the message.
1417However, Exim can be made to verify other addresses as well (often related in
1418some way), and this is useful in some environments. There may therefore be a
1419chain of such addresses that have previously been tested. This function finds
1420whether a given address is on the chain.
1421
1422Arguments: the address to be verified
1423Returns: pointer to an address item, or NULL
1424*/
1425
1426address_item *
1427verify_checked_sender(uschar *sender)
1428{
1429address_item *addr;
1430for (addr = sender_verified_list; addr != NULL; addr = addr->next)
1431 if (Ustrcmp(sender, addr->address) == 0) break;
1432return addr;
1433}
1434
1435
1436
1437
1438
1439/*************************************************
1440* Get valid header address *
1441*************************************************/
1442
1443/* Scan the originator headers of the message, looking for an address that
1444verifies successfully. RFC 822 says:
1445
1446 o The "Sender" field mailbox should be sent notices of
1447 any problems in transport or delivery of the original
1448 messages. If there is no "Sender" field, then the
1449 "From" field mailbox should be used.
1450
1451 o If the "Reply-To" field exists, then the reply should
1452 go to the addresses indicated in that field and not to
1453 the address(es) indicated in the "From" field.
1454
1455So we check a Sender field if there is one, else a Reply_to field, else a From
1456field. As some strange messages may have more than one of these fields,
1457especially if they are resent- fields, check all of them if there is more than
1458one.
1459
1460Arguments:
1461 user_msgptr points to where to put a user error message
1462 log_msgptr points to where to put a log error message
1463 callout timeout for callout check (passed to verify_address())
1464 callout_overall overall callout timeout (ditto)
8e669ac1 1465 callout_connect connect callout timeout (ditto)
059ec3d9
PH
1466 se_mailfrom mailfrom for verify; NULL => ""
1467 pm_mailfrom sender for pm callout check (passed to verify_address())
1468 options callout options (passed to verify_address())
8e669ac1 1469 verrno where to put the address basic_errno
059ec3d9
PH
1470
1471If log_msgptr is set to something without setting user_msgptr, the caller
1472normally uses log_msgptr for both things.
1473
1474Returns: result of the verification attempt: OK, FAIL, or DEFER;
1475 FAIL is given if no appropriate headers are found
1476*/
1477
1478int
1479verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
8e669ac1 1480 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
fe5b5d0b 1481 uschar *pm_mailfrom, int options, int *verrno)
059ec3d9
PH
1482{
1483static int header_types[] = { htype_sender, htype_reply_to, htype_from };
1484int yield = FAIL;
1485int i;
1486
1487for (i = 0; i < 3; i++)
1488 {
1489 header_line *h;
1490 for (h = header_list; h != NULL; h = h->next)
1491 {
1492 int terminator, new_ok;
1493 uschar *s, *ss, *endname;
1494
1495 if (h->type != header_types[i]) continue;
1496 s = endname = Ustrchr(h->text, ':') + 1;
1497
1498 while (*s != 0)
1499 {
1500 address_item *vaddr;
1501
1502 while (isspace(*s) || *s == ',') s++;
1503 if (*s == 0) break; /* End of header */
1504
1505 ss = parse_find_address_end(s, FALSE);
1506
1507 /* The terminator is a comma or end of header, but there may be white
1508 space preceding it (including newline for the last address). Move back
1509 past any white space so we can check against any cached envelope sender
1510 address verifications. */
1511
1512 while (isspace(ss[-1])) ss--;
1513 terminator = *ss;
1514 *ss = 0;
1515
1516 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
1517 (int)(endname - h->text), h->text, s);
1518
1519 /* See if we have already verified this address as an envelope sender,
1520 and if so, use the previous answer. */
1521
1522 vaddr = verify_checked_sender(s);
1523
1524 if (vaddr != NULL && /* Previously checked */
1525 (callout <= 0 || /* No callout needed; OR */
1526 vaddr->special_action > 256)) /* Callout was done */
1527 {
1528 new_ok = vaddr->special_action & 255;
1529 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
1530 *ss = terminator; /* Restore shortened string */
1531 }
1532
1533 /* Otherwise we run the verification now. We must restore the shortened
1534 string before running the verification, so the headers are correct, in
1535 case there is any rewriting. */
1536
1537 else
1538 {
1539 int start, end, domain;
1540 uschar *address = parse_extract_address(s, log_msgptr, &start,
1541 &end, &domain, FALSE);
1542
1543 *ss = terminator;
1544
1545 /* If verification failed because of a syntax error, fail this
1546 function, and ensure that the failing address gets added to the error
1547 message. */
1548
1549 if (address == NULL)
1550 {
1551 new_ok = FAIL;
1552 if (*log_msgptr != NULL)
1553 {
1554 while (ss > s && isspace(ss[-1])) ss--;
1555 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
1556 "scanning for sender: %s in \"%.*s\"",
1557 endname - h->text, h->text, *log_msgptr, ss - s, s);
1558 return FAIL;
1559 }
1560 }
1561
2f6603e1 1562 /* Else go ahead with the sender verification. But it isn't *the*
059ec3d9
PH
1563 sender of the message, so set vopt_fake_sender to stop sender_address
1564 being replaced after rewriting or qualification. */
1565
1566 else
1567 {
1568 vaddr = deliver_make_addr(address, FALSE);
1569 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
8e669ac1 1570 callout, callout_overall, callout_connect, se_mailfrom,
4deaf07d 1571 pm_mailfrom, NULL);
059ec3d9
PH
1572 }
1573 }
1574
1575 /* We now have the result, either newly found, or cached. If we are
1576 giving out error details, set a specific user error. This means that the
1577 last of these will be returned to the user if all three fail. We do not
1578 set a log message - the generic one below will be used. */
1579
fe5b5d0b 1580 if (new_ok != OK)
059ec3d9 1581 {
8e669ac1 1582 *verrno = vaddr->basic_errno;
fe5b5d0b
PH
1583 if (smtp_return_error_details)
1584 {
1585 *user_msgptr = string_sprintf("Rejected after DATA: "
1586 "could not verify \"%.*s\" header address\n%s: %s",
1587 endname - h->text, h->text, vaddr->address, vaddr->message);
1588 }
8e669ac1 1589 }
059ec3d9
PH
1590
1591 /* Success or defer */
1592
1593 if (new_ok == OK) return OK;
1594 if (new_ok == DEFER) yield = DEFER;
1595
1596 /* Move on to any more addresses in the header */
1597
1598 s = ss;
1599 }
1600 }
1601 }
1602
1603if (yield == FAIL && *log_msgptr == NULL)
1604 *log_msgptr = US"there is no valid sender in any header line";
1605
1606if (yield == DEFER && *log_msgptr == NULL)
1607 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
1608
1609return yield;
1610}
1611
1612
1613
1614
1615/*************************************************
1616* Get RFC 1413 identification *
1617*************************************************/
1618
1619/* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
1620the timeout is set to zero, then the query is not done. There may also be lists
1621of hosts and nets which are exempt. To guard against malefactors sending
1622non-printing characters which could, for example, disrupt a message's headers,
1623make sure the string consists of printing characters only.
1624
1625Argument:
1626 port the port to connect to; usually this is IDENT_PORT (113), but when
1627 running in the test harness with -bh a different value is used.
1628
1629Returns: nothing
1630
1631Side effect: any received ident value is put in sender_ident (NULL otherwise)
1632*/
1633
1634void
1635verify_get_ident(int port)
1636{
1637int sock, host_af, qlen;
1638int received_sender_port, received_interface_port, n;
1639uschar *p;
1640uschar buffer[2048];
1641
1642/* Default is no ident. Check whether we want to do an ident check for this
1643host. */
1644
1645sender_ident = NULL;
1646if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
1647 return;
1648
1649DEBUG(D_ident) debug_printf("doing ident callback\n");
1650
1651/* Set up a connection to the ident port of the remote host. Bind the local end
1652to the incoming interface address. If the sender host address is an IPv6
1653address, the incoming interface address will also be IPv6. */
1654
1655host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
1656sock = ip_socket(SOCK_STREAM, host_af);
1657if (sock < 0) return;
1658
1659if (ip_bind(sock, host_af, interface_address, 0) < 0)
1660 {
1661 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
1662 strerror(errno));
1663 goto END_OFF;
1664 }
1665
1666if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
1667 < 0)
1668 {
1669 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
1670 {
1671 log_write(0, LOG_MAIN, "ident connection to %s timed out",
1672 sender_host_address);
1673 }
1674 else
1675 {
1676 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
1677 sender_host_address, strerror(errno));
1678 }
1679 goto END_OFF;
1680 }
1681
1682/* Construct and send the query. */
1683
1684sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
1685qlen = Ustrlen(buffer);
1686if (send(sock, buffer, qlen, 0) < 0)
1687 {
1688 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
1689 goto END_OFF;
1690 }
1691
1692/* Read a response line. We put it into the rest of the buffer, using several
1693recv() calls if necessary. */
1694
1695p = buffer + qlen;
1696
1697for (;;)
1698 {
1699 uschar *pp;
1700 int count;
1701 int size = sizeof(buffer) - (p - buffer);
1702
1703 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
1704 count = ip_recv(sock, p, size, rfc1413_query_timeout);
1705 if (count <= 0) goto END_OFF; /* Read error or EOF */
1706
1707 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
1708 generous, and accept a plain \n terminator as well. The only illegal
1709 character is 0. */
1710
1711 for (pp = p; pp < p + count; pp++)
1712 {
1713 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
1714 if (*pp == '\n')
1715 {
1716 if (pp[-1] == '\r') pp--;
1717 *pp = 0;
1718 goto GOT_DATA; /* Break out of both loops */
1719 }
1720 }
1721
1722 /* Reached the end of the data without finding \n. Let the loop continue to
1723 read some more, if there is room. */
1724
1725 p = pp;
1726 }
1727
1728GOT_DATA:
1729
1730/* We have received a line of data. Check it carefully. It must start with the
1731same two port numbers that we sent, followed by data as defined by the RFC. For
1732example,
1733
1734 12345 , 25 : USERID : UNIX :root
1735
1736However, the amount of white space may be different to what we sent. In the
1737"osname" field there may be several sub-fields, comma separated. The data we
1738actually want to save follows the third colon. Some systems put leading spaces
1739in it - we discard those. */
1740
1741if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
1742 &received_interface_port, &n) != 2 ||
1743 received_sender_port != sender_host_port ||
1744 received_interface_port != interface_port)
1745 goto END_OFF;
1746
1747p = buffer + qlen + n;
1748while(isspace(*p)) p++;
1749if (*p++ != ':') goto END_OFF;
1750while(isspace(*p)) p++;
1751if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
1752p += 6;
1753while(isspace(*p)) p++;
1754if (*p++ != ':') goto END_OFF;
1755while (*p != 0 && *p != ':') p++;
1756if (*p++ == 0) goto END_OFF;
1757while(isspace(*p)) p++;
1758if (*p == 0) goto END_OFF;
1759
1760/* The rest of the line is the data we want. We turn it into printing
1761characters when we save it, so that it cannot mess up the format of any logging
1762or Received: lines into which it gets inserted. We keep a maximum of 127
1763characters. */
1764
1765sender_ident = string_printing(string_copyn(p, 127));
1766DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
1767
1768END_OFF:
1769close(sock);
1770return;
1771}
1772
1773
1774
1775
1776/*************************************************
1777* Match host to a single host-list item *
1778*************************************************/
1779
1780/* This function compares a host (name or address) against a single item
1781from a host list. The host name gets looked up if it is needed and is not
1782already known. The function is called from verify_check_this_host() via
1783match_check_list(), which is why most of its arguments are in a single block.
1784
1785Arguments:
1786 arg the argument block (see below)
1787 ss the host-list item
1788 valueptr where to pass back looked up data, or NULL
1789 error for error message when returning ERROR
1790
1791The block contains:
1792 host_name the host name or NULL, implying use sender_host_name and
1793 sender_host_aliases, looking them up if required
1794 host_address the host address
1795 host_ipv4 the IPv4 address taken from an IPv6 one
1796
1797Returns: OK matched
1798 FAIL did not match
1799 DEFER lookup deferred
1800 ERROR failed to find the host name or IP address
1801 unknown lookup type specified
1802*/
1803
1804static int
1805check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
1806{
1807check_host_block *cb = (check_host_block *)arg;
1808int maskoffset;
1809BOOL isquery = FALSE;
1810uschar *semicolon, *t;
1811uschar **aliases;
1812
1813/* Optimize for the special case when the pattern is "*". */
1814
1815if (*ss == '*' && ss[1] == 0) return OK;
1816
1817/* If the pattern is empty, it matches only in the case when there is no host -
1818this can occur in ACL checking for SMTP input using the -bs option. In this
1819situation, the host address is the empty string. */
1820
1821if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
1822if (*ss == 0) return FAIL;
1823
1824/* If the pattern is precisely "@" then match against the primary host name;
1825if it's "@[]" match against the local host's IP addresses. */
1826
1827if (*ss == '@')
1828 {
1829 if (ss[1] == 0) ss = primary_hostname;
1830 else if (Ustrcmp(ss, "@[]") == 0)
1831 {
1832 ip_address_item *ip;
1833 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
1834 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
1835 return FAIL;
1836 }
1837 }
1838
1839/* If the pattern is an IP address, optionally followed by a bitmask count, do
1840a (possibly masked) comparision with the current IP address. */
1841
a5a28604 1842if (string_is_ip_address(ss, &maskoffset) > 0)
059ec3d9
PH
1843 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
1844
1845/* If the item is of the form net[n]-lookup;<file|query> then it is a lookup on
1846a masked IP network, in textual form. The net- stuff really only applies to
1847single-key lookups where the key is implicit. For query-style lookups the key
1848is specified in the query. From release 4.30, the use of net- for query style
1849is no longer needed, but we retain it for backward compatibility. */
1850
1851if (Ustrncmp(ss, "net", 3) == 0 && (semicolon = Ustrchr(ss, ';')) != NULL)
1852 {
1853 int mlen = 0;
1854 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
1855 if (*t++ == '-')
1856 {
1857 int insize;
1858 int search_type;
1859 int incoming[4];
1860 void *handle;
1861 uschar *filename, *key, *result;
1862 uschar buffer[64];
1863
1864 /* If no mask was supplied, set a negative value */
1865
1866 if (mlen == 0 && t == ss+4) mlen = -1;
1867
1868 /* Find the search type */
1869
1870 search_type = search_findtype(t, semicolon - t);
1871
1872 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1873 search_error_message);
1874
1875 /* Adjust parameters for the type of lookup. For a query-style
1876 lookup, there is no file name, and the "key" is just the query. For
1877 a single-key lookup, the key is the current IP address, masked
8e669ac1 1878 appropriately, and reconverted to text form, with the mask appended.
6f0c9a4f 1879 For IPv6 addresses, specify dot separators instead of colons. */
059ec3d9
PH
1880
1881 if (mac_islookup(search_type, lookup_querystyle))
1882 {
1883 filename = NULL;
1884 key = semicolon + 1;
1885 }
1886 else
1887 {
1888 insize = host_aton(cb->host_address, incoming);
1889 host_mask(insize, incoming, mlen);
6f0c9a4f 1890 (void)host_nmtoa(insize, incoming, mlen, buffer, '.');
059ec3d9
PH
1891 key = buffer;
1892 filename = semicolon + 1;
1893 }
1894
1895 /* Now do the actual lookup; note that there is no search_close() because
1896 of the caching arrangements. */
1897
1898 handle = search_open(filename, search_type, 0, NULL, NULL);
1899 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
1900 search_error_message);
1901 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
1902 if (valueptr != NULL) *valueptr = result;
1903 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
1904 }
1905 }
1906
1907/* The pattern is not an IP address or network reference of any kind. That is,
1908it is a host name pattern. Check the characters of the pattern to see if they
1909comprise only letters, digits, full stops, and hyphens (the constituents of
1910domain names). Allow underscores, as they are all too commonly found. Sigh.
1911Also, if allow_utf8_domains is set, allow top-bit characters. */
1912
1913for (t = ss; *t != 0; t++)
1914 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
1915 (!allow_utf8_domains || *t < 128)) break;
1916
1917/* If the pattern is a complete domain name, with no fancy characters, look up
1918its IP address and match against that. Note that a multi-homed host will add
1919items to the chain. */
1920
1921if (*t == 0)
1922 {
1923 int rc;
1924 host_item h;
1925 h.next = NULL;
1926 h.name = ss;
1927 h.address = NULL;
1928 h.mx = MX_NONE;
1929 rc = host_find_byname(&h, NULL, NULL, FALSE);
1930 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1931 {
1932 host_item *hh;
1933 for (hh = &h; hh != NULL; hh = hh->next)
1934 {
1935 if (Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)?
1936 cb->host_ipv4 : cb->host_address) == 0)
1937 return OK;
1938 }
1939 return FAIL;
1940 }
1941 if (rc == HOST_FIND_AGAIN) return DEFER;
1942 *error = string_sprintf("failed to find IP address for %s", ss);
1943 return ERROR;
1944 }
1945
1946/* Almost all subsequent comparisons require the host name, and can be done
1947using the general string matching function. When this function is called for
1948outgoing hosts, the name is always given explicitly. If it is NULL, it means we
1949must use sender_host_name and its aliases, looking them up if necessary. */
1950
1951if (cb->host_name != NULL) /* Explicit host name given */
1952 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
1953 valueptr);
1954
1955/* Host name not given; in principle we need the sender host name and its
1956aliases. However, for query-style lookups, we do not need the name if the
1957query does not contain $sender_host_name. From release 4.23, a reference to
1958$sender_host_name causes it to be looked up, so we don't need to do the lookup
1959on spec. */
1960
1961if ((semicolon = Ustrchr(ss, ';')) != NULL)
1962 {
1963 uschar *affix;
1964 int partial, affixlen, starflags, id;
1965
1966 *semicolon = 0;
1967 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
1968 *semicolon=';';
1969
1970 if (id < 0) /* Unknown lookup type */
1971 {
1972 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
1973 search_error_message, ss);
1974 return DEFER;
1975 }
1976 isquery = mac_islookup(id, lookup_querystyle);
1977 }
1978
1979if (isquery)
1980 {
1981 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
1982 {
1983 case OK: return OK;
1984 case DEFER: return DEFER;
1985 default: return FAIL;
1986 }
1987 }
1988
1989/* Not a query-style lookup; must ensure the host name is present, and then we
1990do a check on the name and all its aliases. */
1991
1992if (sender_host_name == NULL)
1993 {
1994 HDEBUG(D_host_lookup)
1995 debug_printf("sender host name required, to match against %s\n", ss);
1996 if (host_lookup_failed || host_name_lookup() != OK)
1997 {
1998 *error = string_sprintf("failed to find host name for %s",
1999 sender_host_address);;
2000 return ERROR;
2001 }
2002 host_build_sender_fullhost();
2003 }
2004
2005/* Match on the sender host name, using the general matching function */
2006
2007switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2008 valueptr))
2009 {
2010 case OK: return OK;
2011 case DEFER: return DEFER;
2012 }
2013
2014/* If there are aliases, try matching on them. */
2015
2016aliases = sender_host_aliases;
2017while (*aliases != NULL)
2018 {
2019 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2020 {
2021 case OK: return OK;
2022 case DEFER: return DEFER;
2023 }
2024 }
2025return FAIL;
2026}
2027
2028
2029
2030
2031/*************************************************
2032* Check a specific host matches a host list *
2033*************************************************/
2034
2035/* This function is passed a host list containing items in a number of
2036different formats and the identity of a host. Its job is to determine whether
2037the given host is in the set of hosts defined by the list. The host name is
2038passed as a pointer so that it can be looked up if needed and not already
2039known. This is commonly the case when called from verify_check_host() to check
2040an incoming connection. When called from elsewhere the host name should usually
2041be set.
2042
2043This function is now just a front end to match_check_list(), which runs common
2044code for scanning a list. We pass it the check_host() function to perform a
2045single test.
2046
2047Arguments:
2048 listptr pointer to the host list
2049 cache_bits pointer to cache for named lists, or NULL
2050 host_name the host name or NULL, implying use sender_host_name and
2051 sender_host_aliases, looking them up if required
2052 host_address the IP address
2053 valueptr if not NULL, data from a lookup is passed back here
2054
2055Returns: OK if the host is in the defined set
2056 FAIL if the host is not in the defined set,
2057 DEFER if a data lookup deferred (not a host lookup)
2058
2059If the host name was needed in order to make a comparison, and could not be
2060determined from the IP address, the result is FAIL unless the item
2061"+allow_unknown" was met earlier in the list, in which case OK is returned. */
2062
2063int
2064verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2065 uschar *host_name, uschar *host_address, uschar **valueptr)
2066{
d4eb88df 2067int rc;
059ec3d9 2068unsigned int *local_cache_bits = cache_bits;
d4eb88df 2069uschar *save_host_address = deliver_host_address;
059ec3d9
PH
2070check_host_block cb;
2071cb.host_name = host_name;
2072cb.host_address = host_address;
2073
2074if (valueptr != NULL) *valueptr = NULL;
2075
2076/* If the host address starts off ::ffff: it is an IPv6 address in
2077IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2078addresses. */
2079
2080cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2081 host_address + 7 : host_address;
2082
8e669ac1
PH
2083/* During the running of the check, put the IP address into $host_address. In
2084the case of calls from the smtp transport, it will already be there. However,
2085in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
d4eb88df
PH
2086the safe side, any existing setting is preserved, though as I write this
2087(November 2004) I can't see any cases where it is actually needed. */
2088
2089deliver_host_address = host_address;
2090rc = match_check_list(
2091 listptr, /* the list */
2092 0, /* separator character */
2093 &hostlist_anchor, /* anchor pointer */
2094 &local_cache_bits, /* cache pointer */
2095 check_host, /* function for testing */
2096 &cb, /* argument for function */
2097 MCL_HOST, /* type of check */
8e669ac1 2098 (host_address == sender_host_address)?
d4eb88df
PH
2099 US"host" : host_address, /* text for debugging */
2100 valueptr); /* where to pass back data */
2101deliver_host_address = save_host_address;
8e669ac1 2102return rc;
059ec3d9
PH
2103}
2104
2105
2106
2107
2108/*************************************************
2109* Check the remote host matches a list *
2110*************************************************/
2111
2112/* This is a front end to verify_check_this_host(), created because checking
2113the remote host is a common occurrence. With luck, a good compiler will spot
2114the tail recursion and optimize it. If there's no host address, this is
2115command-line SMTP input - check against an empty string for the address.
2116
2117Arguments:
2118 listptr pointer to the host list
2119
2120Returns: the yield of verify_check_this_host(),
2121 i.e. OK, FAIL, or DEFER
2122*/
2123
2124int
2125verify_check_host(uschar **listptr)
2126{
2127return verify_check_this_host(listptr, sender_host_cache, NULL,
2128 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
2129}
2130
2131
2132
2133
2134
2135/*************************************************
2136* Invert an IP address for a DNS black list *
2137*************************************************/
2138
2139/*
2140Arguments:
2141 buffer where to put the answer
2142 address the address to invert
2143*/
2144
2145static void
2146invert_address(uschar *buffer, uschar *address)
2147{
2148int bin[4];
2149uschar *bptr = buffer;
2150
2151/* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
2152to the IPv4 part only. */
2153
2154if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
2155
2156/* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
2157always 1. */
2158
2159if (host_aton(address, bin) == 1)
2160 {
2161 int i;
2162 int x = bin[0];
2163 for (i = 0; i < 4; i++)
2164 {
2165 sprintf(CS bptr, "%d.", x & 255);
2166 while (*bptr) bptr++;
2167 x >>= 8;
2168 }
2169 }
2170
2171/* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
2172in any DNS black lists, and the format in which they will be looked up is
2173unknown. This is just a guess. */
2174
2175#if HAVE_IPV6
2176else
2177 {
2178 int i, j;
2179 for (j = 3; j >= 0; j--)
2180 {
2181 int x = bin[j];
2182 for (i = 0; i < 8; i++)
2183 {
2184 sprintf(CS bptr, "%x.", x & 15);
2185 while (*bptr) bptr++;
2186 x >>= 4;
2187 }
2188 }
2189 }
2190#endif
2191}
2192
2193
2194
2195/*************************************************
0bcb2a0e
PH
2196* Perform a single dnsbl lookup *
2197*************************************************/
2198
2199/* This function is called from verify_check_dnsbl() below.
2200
2201Arguments:
2202 domain the outer dnsbl domain (for debug message)
8e669ac1 2203 keydomain the current keydomain (for debug message)
0bcb2a0e 2204 query the domain to be looked up
8e669ac1
PH
2205 iplist the list of matching IP addresses
2206 bitmask true if bitmask matching is wanted
2207 invert_result true if result to be inverted
2208 defer_return what to return for a defer
0bcb2a0e
PH
2209
2210Returns: OK if lookup succeeded
2211 FAIL if not
2212*/
2213
2214static int
8e669ac1 2215one_check_dnsbl(uschar *domain, uschar *keydomain, uschar *query,
0bcb2a0e 2216 uschar *iplist, BOOL bitmask, BOOL invert_result, int defer_return)
8e669ac1 2217{
0bcb2a0e
PH
2218dns_answer dnsa;
2219dns_scan dnss;
2220tree_node *t;
2221dnsbl_cache_block *cb;
2222int old_pool = store_pool;
2223
2224/* Look for this query in the cache. */
2225
2226t = tree_search(dnsbl_cache, query);
2227
2228/* If not cached from a previous lookup, we must do a DNS lookup, and
2229cache the result in permanent memory. */
2230
2231if (t == NULL)
2232 {
2233 store_pool = POOL_PERM;
2234
2235 /* Set up a tree entry to cache the lookup */
2236
2237 t = store_get(sizeof(tree_node) + Ustrlen(query));
2238 Ustrcpy(t->name, query);
2239 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
2240 (void)tree_insertnode(&dnsbl_cache, t);
2241
2242 /* Do the DNS loopup . */
2243
2244 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
2245 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
2246 cb->text_set = FALSE;
2247 cb->text = NULL;
2248 cb->rhs = NULL;
2249
2250 /* If the lookup succeeded, cache the RHS address. The code allows for
2251 more than one address - this was for complete generality and the possible
2252 use of A6 records. However, A6 records have been reduced to experimental
2253 status (August 2001) and may die out. So they may never get used at all,
2254 let alone in dnsbl records. However, leave the code here, just in case.
2255
2256 Quite apart from one A6 RR generating multiple addresses, there are DNS
2257 lists that return more than one A record, so we must handle multiple
2258 addresses generated in that way as well. */
2259
2260 if (cb->rc == DNS_SUCCEED)
2261 {
2262 dns_record *rr;
2263 dns_address **addrp = &(cb->rhs);
2264 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2265 rr != NULL;
2266 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2267 {
2268 if (rr->type == T_A)
2269 {
2270 dns_address *da = dns_address_from_rr(&dnsa, rr);
2271 if (da != NULL)
2272 {
2273 *addrp = da;
2274 while (da->next != NULL) da = da->next;
2275 addrp = &(da->next);
2276 }
2277 }
2278 }
2279
2280 /* If we didn't find any A records, change the return code. This can
2281 happen when there is a CNAME record but there are no A records for what
2282 it points to. */
2283
2284 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
2285 }
2286
2287 store_pool = old_pool;
2288 }
2289
2290/* Previous lookup was cached */
2291
2292else
2293 {
2294 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
2295 cb = t->data.ptr;
2296 }
2297
2298/* We now have the result of the DNS lookup, either newly done, or cached
2299from a previous call. If the lookup succeeded, check against the address
2300list if there is one. This may be a positive equality list (introduced by
2301"="), a negative equality list (introduced by "!="), a positive bitmask
2302list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
2303
2304if (cb->rc == DNS_SUCCEED)
2305 {
2306 dns_address *da = NULL;
2307 uschar *addlist = cb->rhs->address;
2308
2309 /* For A and AAAA records, there may be multiple addresses from multiple
2310 records. For A6 records (currently not expected to be used) there may be
2311 multiple addresses from a single record. */
2312
2313 for (da = cb->rhs->next; da != NULL; da = da->next)
2314 addlist = string_sprintf("%s, %s", addlist, da->address);
2315
2316 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
2317 query, addlist);
2318
2319 /* Address list check; this can be either for equality, or via a bitmask.
2320 In the latter case, all the bits must match. */
2321
2322 if (iplist != NULL)
2323 {
2324 int ipsep = ',';
2325 uschar ip[46];
2326 uschar *ptr = iplist;
2327
2328 while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL)
2329 {
2330 /* Handle exact matching */
2331 if (!bitmask)
2332 {
2333 for (da = cb->rhs; da != NULL; da = da->next)
2334 {
2335 if (Ustrcmp(CS da->address, ip) == 0) break;
2336 }
2337 }
2338 /* Handle bitmask matching */
2339 else
2340 {
2341 int address[4];
2342 int mask = 0;
2343
2344 /* At present, all known DNS blocking lists use A records, with
2345 IPv4 addresses on the RHS encoding the information they return. I
2346 wonder if this will linger on as the last vestige of IPv4 when IPv6
2347 is ubiquitous? Anyway, for now we use paranoia code to completely
2348 ignore IPv6 addresses. The default mask is 0, which always matches.
2349 We change this only for IPv4 addresses in the list. */
2350
2351 if (host_aton(ip, address) == 1) mask = address[0];
2352
2353 /* Scan the returned addresses, skipping any that are IPv6 */
2354
2355 for (da = cb->rhs; da != NULL; da = da->next)
2356 {
2357 if (host_aton(da->address, address) != 1) continue;
2358 if ((address[0] & mask) == mask) break;
2359 }
2360 }
2361
2362 /* Break out if a match has been found */
2363
2364 if (da != NULL) break;
2365 }
2366
2367 /* If either
2368
2369 (a) No IP address in a positive list matched, or
2370 (b) An IP address in a negative list did match
2371
2372 then behave as if the DNSBL lookup had not succeeded, i.e. the host is
2373 not on the list. */
2374
2375 if (invert_result != (da == NULL))
2376 {
2377 HDEBUG(D_dnsbl)
2378 {
2379 debug_printf("=> but we are not accepting this block class because\n");
2380 debug_printf("=> there was %s match for %c%s\n",
2381 invert_result? "an exclude":"no", bitmask? '&' : '=', iplist);
2382 }
8e669ac1 2383 return FAIL;
0bcb2a0e
PH
2384 }
2385 }
2386
2387 /* Either there was no IP list, or the record matched. Look up a TXT record
2388 if it hasn't previously been done. */
2389
2390 if (!cb->text_set)
2391 {
2392 cb->text_set = TRUE;
2393 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
2394 {
2395 dns_record *rr;
2396 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2397 rr != NULL;
2398 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2399 if (rr->type == T_TXT) break;
2400 if (rr != NULL)
2401 {
2402 int len = (rr->data)[0];
2403 if (len > 511) len = 127;
2404 store_pool = POOL_PERM;
2405 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
2406 store_pool = old_pool;
2407 }
2408 }
2409 }
2410
2411 dnslist_value = addlist;
2412 dnslist_text = cb->text;
2413 return OK;
2414 }
2415
2416/* There was a problem with the DNS lookup */
2417
2418if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
2419 {
2420 log_write(L_dnslist_defer, LOG_MAIN,
2421 "DNS list lookup defer (probably timeout) for %s: %s", query,
2422 (defer_return == OK)? US"assumed in list" :
2423 (defer_return == FAIL)? US"assumed not in list" :
2424 US"returned DEFER");
2425 return defer_return;
2426 }
2427
2428/* No entry was found in the DNS; continue for next domain */
2429
2430HDEBUG(D_dnsbl)
2431 {
2432 debug_printf("DNS lookup for %s failed\n", query);
2433 debug_printf("=> that means %s is not listed at %s\n",
2434 keydomain, domain);
2435 }
2436
2437return FAIL;
2438}
2439
2440
2441
2442
2443/*************************************************
059ec3d9
PH
2444* Check host against DNS black lists *
2445*************************************************/
2446
2447/* This function runs checks against a list of DNS black lists, until one
2448matches. Each item on the list can be of the form
2449
2450 domain=ip-address/key
2451
2452The domain is the right-most domain that is used for the query, for example,
2453blackholes.mail-abuse.org. If the IP address is present, there is a match only
2454if the DNS lookup returns a matching IP address. Several addresses may be
2455given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
2456
2457If no key is given, what is looked up in the domain is the inverted IP address
2458of the current client host. If a key is given, it is used to construct the
2459domain for the lookup. For example,
2460
2461 dsn.rfc-ignorant.org/$sender_address_domain
2462
2463After finding a match in the DNS, the domain is placed in $dnslist_domain, and
2464then we check for a TXT record for an error message, and if found, save its
2465value in $dnslist_text. We also cache everything in a tree, to optimize
2466multiple lookups.
2467
2468Note: an address for testing RBL is 192.203.178.39
2469Note: an address for testing DUL is 192.203.178.4
2470Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
2471
2472Arguments:
2473 listptr the domain/address/data list
2474
2475Returns: OK successful lookup (i.e. the address is on the list), or
2476 lookup deferred after +include_unknown
2477 FAIL name not found, or no data found for the given type, or
2478 lookup deferred after +exclude_unknown (default)
2479 DEFER lookup failure, if +defer_unknown was set
2480*/
2481
2482int
2483verify_check_dnsbl(uschar **listptr)
2484{
2485int sep = 0;
2486int defer_return = FAIL;
059ec3d9
PH
2487BOOL invert_result = FALSE;
2488uschar *list = *listptr;
2489uschar *domain;
2490uschar *s;
2491uschar buffer[1024];
2492uschar query[256]; /* DNS domain max length */
2493uschar revadd[128]; /* Long enough for IPv6 address */
2494
2495/* Indicate that the inverted IP address is not yet set up */
2496
2497revadd[0] = 0;
2498
0bcb2a0e
PH
2499/* In case this is the first time the DNS resolver is being used. */
2500
2501dns_init(FALSE, FALSE);
2502
059ec3d9
PH
2503/* Loop through all the domains supplied, until something matches */
2504
2505while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
2506 {
0bcb2a0e 2507 int rc;
059ec3d9
PH
2508 BOOL frc;
2509 BOOL bitmask = FALSE;
059ec3d9
PH
2510 uschar *iplist;
2511 uschar *key;
059ec3d9
PH
2512
2513 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
2514
2515 /* Deal with special values that change the behaviour on defer */
2516
2517 if (domain[0] == '+')
2518 {
2519 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
2520 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
2521 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
2522 else
2523 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
2524 domain);
2525 continue;
2526 }
2527
2528 /* See if there's explicit data to be looked up */
2529
2530 key = Ustrchr(domain, '/');
2531 if (key != NULL) *key++ = 0;
2532
2533 /* See if there's a list of addresses supplied after the domain name. This is
2534 introduced by an = or a & character; if preceded by ! we invert the result.
2535 */
2536
2537 iplist = Ustrchr(domain, '=');
2538 if (iplist == NULL)
2539 {
2540 bitmask = TRUE;
2541 iplist = Ustrchr(domain, '&');
2542 }
2543
2544 if (iplist != NULL)
2545 {
2546 if (iplist > domain && iplist[-1] == '!')
2547 {
2548 invert_result = TRUE;
2549 iplist[-1] = 0;
2550 }
2551 *iplist++ = 0;
2552 }
2553
2554 /* Check that what we have left is a sensible domain name. There is no reason
2555 why these domains should in fact use the same syntax as hosts and email
2556 domains, but in practice they seem to. However, there is little point in
2557 actually causing an error here, because that would no doubt hold up incoming
2558 mail. Instead, I'll just log it. */
2559
2560 for (s = domain; *s != 0; s++)
2561 {
2562 if (!isalnum(*s) && *s != '-' && *s != '.')
2563 {
2564 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
2565 "strange characters - is this right?", domain);
2566 break;
2567 }
2568 }
2569
8e669ac1 2570 /* If there is no key string, construct the query by adding the domain name
0bcb2a0e 2571 onto the inverted host address, and perform a single DNS lookup. */
8e669ac1 2572
059ec3d9
PH
2573 if (key == NULL)
2574 {
2575 if (sender_host_address == NULL) return FAIL; /* can never match */
2576 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
2577 frc = string_format(query, sizeof(query), "%s%s", revadd, domain);
8e669ac1 2578
0bcb2a0e 2579 if (!frc)
059ec3d9 2580 {
0bcb2a0e
PH
2581 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2582 "(ignored): %s...", query);
2583 continue;
059ec3d9 2584 }
8e669ac1
PH
2585
2586 rc = one_check_dnsbl(domain, sender_host_address, query, iplist, bitmask,
0bcb2a0e 2587 invert_result, defer_return);
8e669ac1 2588
0bcb2a0e
PH
2589 if (rc == OK)
2590 {
2591 dnslist_domain = string_copy(domain);
8e669ac1 2592 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
0bcb2a0e
PH
2593 sender_host_address, domain);
2594 }
8e669ac1 2595
0bcb2a0e 2596 if (rc != FAIL) return rc; /* OK or DEFER */
059ec3d9 2597 }
8e669ac1
PH
2598
2599 /* If there is a key string, it can be a list of domains or IP addresses to
0bcb2a0e 2600 be concatenated with the main domain. */
8e669ac1 2601
059ec3d9
PH
2602 else
2603 {
0bcb2a0e 2604 int keysep = 0;
8e669ac1
PH
2605 BOOL defer = FALSE;
2606 uschar *keydomain;
0bcb2a0e 2607 uschar keybuffer[256];
8e669ac1
PH
2608
2609 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
0bcb2a0e 2610 sizeof(keybuffer))) != NULL)
8e669ac1 2611 {
a5a28604 2612 if (string_is_ip_address(keydomain, NULL) > 0)
059ec3d9 2613 {
0bcb2a0e
PH
2614 uschar keyrevadd[128];
2615 invert_address(keyrevadd, keydomain);
8e669ac1 2616 frc = string_format(query, sizeof(query), "%s%s", keyrevadd, domain);
0bcb2a0e
PH
2617 }
2618 else
8e669ac1 2619 {
0bcb2a0e 2620 frc = string_format(query, sizeof(query), "%s.%s", keydomain, domain);
059ec3d9
PH
2621 }
2622
0bcb2a0e 2623 if (!frc)
059ec3d9 2624 {
0bcb2a0e
PH
2625 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2626 "(ignored): %s...", query);
2627 continue;
059ec3d9 2628 }
8e669ac1
PH
2629
2630 rc = one_check_dnsbl(domain, keydomain, query, iplist, bitmask,
0bcb2a0e 2631 invert_result, defer_return);
8e669ac1 2632
0bcb2a0e 2633 if (rc == OK)
059ec3d9 2634 {
0bcb2a0e 2635 dnslist_domain = string_copy(domain);
8e669ac1 2636 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
0bcb2a0e 2637 keydomain, domain);
8e669ac1 2638 return OK;
059ec3d9 2639 }
8e669ac1 2640
c38d6da9
PH
2641 /* If the lookup deferred, remember this fact. We keep trying the rest
2642 of the list to see if we get a useful result, and if we don't, we return
2643 DEFER at the end. */
059ec3d9 2644
c38d6da9 2645 if (rc == DEFER) defer = TRUE;
0bcb2a0e 2646 } /* continue with next keystring domain/address */
c38d6da9
PH
2647
2648 if (defer) return DEFER;
8e669ac1 2649 }
0bcb2a0e 2650 } /* continue with next dnsdb outer domain */
059ec3d9
PH
2651
2652return FAIL;
2653}
2654
2655/* End of verify.c */