b73f45a2451bd18bfbf5fde0c1f70ae5c431036a
[exim.git] / src / src / verify.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2015 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
10
11
12 #include "exim.h"
13 #include "transports/smtp.h"
14
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
19
20
21 /* Structure for caching DNSBL lookups */
22
23 typedef struct dnsbl_cache_block {
24 time_t expiry;
25 dns_address *rhs;
26 uschar *text;
27 int rc;
28 BOOL text_set;
29 } dnsbl_cache_block;
30
31
32 /* Anchor for DNSBL cache */
33
34 static tree_node *dnsbl_cache = NULL;
35
36
37 /* Bits for match_type in one_check_dnsbl() */
38
39 #define MT_NOT 1
40 #define MT_ALL 2
41
42 static uschar cutthrough_response(char, uschar **);
43
44
45 /*************************************************
46 * Retrieve a callout cache record *
47 *************************************************/
48
49 /* If a record exists, check whether it has expired.
50
51 Arguments:
52 dbm_file an open hints file
53 key the record key
54 type "address" or "domain"
55 positive_expire expire time for positive records
56 negative_expire expire time for negative records
57
58 Returns: the cache record if a non-expired one exists, else NULL
59 */
60
61 static dbdata_callout_cache *
62 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
63 int positive_expire, int negative_expire)
64 {
65 BOOL negative;
66 int length, expire;
67 time_t now;
68 dbdata_callout_cache *cache_record;
69
70 cache_record = dbfn_read_with_length(dbm_file, key, &length);
71
72 if (cache_record == NULL)
73 {
74 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
75 return NULL;
76 }
77
78 /* We treat a record as "negative" if its result field is not positive, or if
79 it is a domain record and the postmaster field is negative. */
80
81 negative = cache_record->result != ccache_accept ||
82 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
83 expire = negative? negative_expire : positive_expire;
84 now = time(NULL);
85
86 if (now - cache_record->time_stamp > expire)
87 {
88 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
89 return NULL;
90 }
91
92 /* If this is a non-reject domain record, check for the obsolete format version
93 that doesn't have the postmaster and random timestamps, by looking at the
94 length. If so, copy it to a new-style block, replicating the record's
95 timestamp. Then check the additional timestamps. (There's no point wasting
96 effort if connections are rejected.) */
97
98 if (type[0] == 'd' && cache_record->result != ccache_reject)
99 {
100 if (length == sizeof(dbdata_callout_cache_obs))
101 {
102 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
103 memcpy(new, cache_record, length);
104 new->postmaster_stamp = new->random_stamp = new->time_stamp;
105 cache_record = new;
106 }
107
108 if (now - cache_record->postmaster_stamp > expire)
109 cache_record->postmaster_result = ccache_unknown;
110
111 if (now - cache_record->random_stamp > expire)
112 cache_record->random_result = ccache_unknown;
113 }
114
115 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
116 return cache_record;
117 }
118
119
120
121 /*************************************************
122 * Do callout verification for an address *
123 *************************************************/
124
125 /* This function is called from verify_address() when the address has routed to
126 a host list, and a callout has been requested. Callouts are expensive; that is
127 why a cache is used to improve the efficiency.
128
129 Arguments:
130 addr the address that's been routed
131 host_list the list of hosts to try
132 tf the transport feedback block
133
134 ifstring "interface" option from transport, or NULL
135 portstring "port" option from transport, or NULL
136 protocolstring "protocol" option from transport, or NULL
137 callout the per-command callout timeout
138 callout_overall the overall callout timeout (if < 0 use 4*callout)
139 callout_connect the callout connection timeout (if < 0 use callout)
140 options the verification options - these bits are used:
141 vopt_is_recipient => this is a recipient address
142 vopt_callout_no_cache => don't use callout cache
143 vopt_callout_fullpm => if postmaster check, do full one
144 vopt_callout_random => do the "random" thing
145 vopt_callout_recipsender => use real sender for recipient
146 vopt_callout_recippmaster => use postmaster for recipient
147 se_mailfrom MAIL FROM address for sender verify; NULL => ""
148 pm_mailfrom if non-NULL, do the postmaster check with this sender
149
150 Returns: OK/FAIL/DEFER
151 */
152
153 static int
154 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
155 int callout, int callout_overall, int callout_connect, int options,
156 uschar *se_mailfrom, uschar *pm_mailfrom)
157 {
158 BOOL is_recipient = (options & vopt_is_recipient) != 0;
159 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
160 BOOL callout_random = (options & vopt_callout_random) != 0;
161
162 int yield = OK;
163 int old_domain_cache_result = ccache_accept;
164 BOOL done = FALSE;
165 uschar *address_key;
166 uschar *from_address;
167 uschar *random_local_part = NULL;
168 const uschar *save_deliver_domain = deliver_domain;
169 uschar **failure_ptr = is_recipient?
170 &recipient_verify_failure : &sender_verify_failure;
171 open_db dbblock;
172 open_db *dbm_file = NULL;
173 dbdata_callout_cache new_domain_record;
174 dbdata_callout_cache_address new_address_record;
175 host_item *host;
176 time_t callout_start_time;
177 #ifdef SUPPORT_I18N
178 BOOL utf8_offered = FALSE;
179 #endif
180
181 new_domain_record.result = ccache_unknown;
182 new_domain_record.postmaster_result = ccache_unknown;
183 new_domain_record.random_result = ccache_unknown;
184
185 memset(&new_address_record, 0, sizeof(new_address_record));
186
187 /* For a recipient callout, the key used for the address cache record must
188 include the sender address if we are using the real sender in the callout,
189 because that may influence the result of the callout. */
190
191 address_key = addr->address;
192 from_address = US"";
193
194 if (is_recipient)
195 {
196 if (options & vopt_callout_recipsender)
197 {
198 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
199 from_address = sender_address;
200 }
201 else if (options & vopt_callout_recippmaster)
202 {
203 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
204 qualify_domain_sender);
205 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
206 }
207 }
208
209 /* For a sender callout, we must adjust the key if the mailfrom address is not
210 empty. */
211
212 else
213 {
214 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
215 if (from_address[0] != 0)
216 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
217 }
218
219 /* Open the callout cache database, it it exists, for reading only at this
220 stage, unless caching has been disabled. */
221
222 if (callout_no_cache)
223 {
224 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
225 }
226 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
227 {
228 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
229 }
230
231 /* If a cache database is available see if we can avoid the need to do an
232 actual callout by making use of previously-obtained data. */
233
234 if (dbm_file != NULL)
235 {
236 dbdata_callout_cache_address *cache_address_record;
237 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
238 addr->domain, US"domain",
239 callout_cache_domain_positive_expire,
240 callout_cache_domain_negative_expire);
241
242 /* If an unexpired cache record was found for this domain, see if the callout
243 process can be short-circuited. */
244
245 if (cache_record != NULL)
246 {
247 /* In most cases, if an early command (up to and including MAIL FROM:<>)
248 was rejected, there is no point carrying on. The callout fails. However, if
249 we are doing a recipient verification with use_sender or use_postmaster
250 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
251 will be using a non-empty sender. We have to remember this situation so as
252 not to disturb the cached domain value if this whole verification succeeds
253 (we don't want it turning into "accept"). */
254
255 old_domain_cache_result = cache_record->result;
256
257 if (cache_record->result == ccache_reject ||
258 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
259 {
260 setflag(addr, af_verify_nsfail);
261 HDEBUG(D_verify)
262 debug_printf("callout cache: domain gave initial rejection, or "
263 "does not accept HELO or MAIL FROM:<>\n");
264 setflag(addr, af_verify_nsfail);
265 addr->user_message = US"(result of an earlier callout reused).";
266 yield = FAIL;
267 *failure_ptr = US"mail";
268 goto END_CALLOUT;
269 }
270
271 /* If a previous check on a "random" local part was accepted, we assume
272 that the server does not do any checking on local parts. There is therefore
273 no point in doing the callout, because it will always be successful. If a
274 random check previously failed, arrange not to do it again, but preserve
275 the data in the new record. If a random check is required but hasn't been
276 done, skip the remaining cache processing. */
277
278 if (callout_random) switch(cache_record->random_result)
279 {
280 case ccache_accept:
281 HDEBUG(D_verify)
282 debug_printf("callout cache: domain accepts random addresses\n");
283 goto END_CALLOUT; /* Default yield is OK */
284
285 case ccache_reject:
286 HDEBUG(D_verify)
287 debug_printf("callout cache: domain rejects random addresses\n");
288 callout_random = FALSE;
289 new_domain_record.random_result = ccache_reject;
290 new_domain_record.random_stamp = cache_record->random_stamp;
291 break;
292
293 default:
294 HDEBUG(D_verify)
295 debug_printf("callout cache: need to check random address handling "
296 "(not cached or cache expired)\n");
297 goto END_CACHE;
298 }
299
300 /* If a postmaster check is requested, but there was a previous failure,
301 there is again no point in carrying on. If a postmaster check is required,
302 but has not been done before, we are going to have to do a callout, so skip
303 remaining cache processing. */
304
305 if (pm_mailfrom != NULL)
306 {
307 if (cache_record->postmaster_result == ccache_reject)
308 {
309 setflag(addr, af_verify_pmfail);
310 HDEBUG(D_verify)
311 debug_printf("callout cache: domain does not accept "
312 "RCPT TO:<postmaster@domain>\n");
313 yield = FAIL;
314 *failure_ptr = US"postmaster";
315 setflag(addr, af_verify_pmfail);
316 addr->user_message = US"(result of earlier verification reused).";
317 goto END_CALLOUT;
318 }
319 if (cache_record->postmaster_result == ccache_unknown)
320 {
321 HDEBUG(D_verify)
322 debug_printf("callout cache: need to check RCPT "
323 "TO:<postmaster@domain> (not cached or cache expired)\n");
324 goto END_CACHE;
325 }
326
327 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
328 postmaster check if the address itself has to be checked. Also ensure
329 that the value in the cache record is preserved (with its old timestamp).
330 */
331
332 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
333 "TO:<postmaster@domain>\n");
334 pm_mailfrom = NULL;
335 new_domain_record.postmaster_result = ccache_accept;
336 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
337 }
338 }
339
340 /* We can't give a result based on information about the domain. See if there
341 is an unexpired cache record for this specific address (combined with the
342 sender address if we are doing a recipient callout with a non-empty sender).
343 */
344
345 cache_address_record = (dbdata_callout_cache_address *)
346 get_callout_cache_record(dbm_file,
347 address_key, US"address",
348 callout_cache_positive_expire,
349 callout_cache_negative_expire);
350
351 if (cache_address_record != NULL)
352 {
353 if (cache_address_record->result == ccache_accept)
354 {
355 HDEBUG(D_verify)
356 debug_printf("callout cache: address record is positive\n");
357 }
358 else
359 {
360 HDEBUG(D_verify)
361 debug_printf("callout cache: address record is negative\n");
362 addr->user_message = US"Previous (cached) callout verification failure";
363 *failure_ptr = US"recipient";
364 yield = FAIL;
365 }
366 goto END_CALLOUT;
367 }
368
369 /* Close the cache database while we actually do the callout for real. */
370
371 END_CACHE:
372 dbfn_close(dbm_file);
373 dbm_file = NULL;
374 }
375
376 if (!addr->transport)
377 {
378 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
379 }
380 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
381 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
382 addr->transport->name, addr->transport->driver_name);
383 else
384 {
385 smtp_transport_options_block *ob =
386 (smtp_transport_options_block *)addr->transport->options_block;
387
388 /* The information wasn't available in the cache, so we have to do a real
389 callout and save the result in the cache for next time, unless no_cache is set,
390 or unless we have a previously cached negative random result. If we are to test
391 with a random local part, ensure that such a local part is available. If not,
392 log the fact, but carry on without randomming. */
393
394 if (callout_random && callout_random_local_part != NULL)
395 if (!(random_local_part = expand_string(callout_random_local_part)))
396 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
397 "callout_random_local_part: %s", expand_string_message);
398
399 /* Default the connect and overall callout timeouts if not set, and record the
400 time we are starting so that we can enforce it. */
401
402 if (callout_overall < 0) callout_overall = 4 * callout;
403 if (callout_connect < 0) callout_connect = callout;
404 callout_start_time = time(NULL);
405
406 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
407 output because a callout might take some time. When PIPELINING is active and
408 there are many recipients, the total time for doing lots of callouts can add up
409 and cause the client to time out. So in this case we forgo the PIPELINING
410 optimization. */
411
412 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
413
414 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
415 and we are holding a cutthrough conn open, we can just append the rcpt to
416 that conn for verification purposes (and later delivery also). Simplest
417 coding means skipping this whole loop and doing the append separately.
418
419 We will need to remember it has been appended so that rcpt-acl tail code
420 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
421 */
422
423 /* Can we re-use an open cutthrough connection? */
424 if ( cutthrough.fd >= 0
425 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
426 == vopt_callout_recipsender
427 && !random_local_part
428 && !pm_mailfrom
429 )
430 {
431 if (addr->transport == cutthrough.addr.transport)
432 for (host = host_list; host; host = host->next)
433 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
434 {
435 int host_af;
436 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
437 int port = 25;
438
439 deliver_host = host->name;
440 deliver_host_address = host->address;
441 deliver_host_port = host->port;
442 deliver_domain = addr->domain;
443 transport_name = addr->transport->name;
444
445 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
446
447 if (!smtp_get_interface(tf->interface, host_af, addr, &interface,
448 US"callout") ||
449 !smtp_get_port(tf->port, addr, &port, US"callout"))
450 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
451 addr->message);
452
453 if ( ( interface == cutthrough.interface
454 || ( interface
455 && cutthrough.interface
456 && Ustrcmp(interface, cutthrough.interface) == 0
457 ) )
458 && port == cutthrough.host.port
459 )
460 {
461 uschar * resp;
462
463 /* Match! Send the RCPT TO, append the addr, set done */
464 done =
465 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
466 transport_rcpt_address(addr,
467 (addr->transport == NULL)? FALSE :
468 addr->transport->rcpt_include_affixes)) >= 0 &&
469 cutthrough_response('2', &resp) == '2';
470
471 /* This would go horribly wrong if a callout fail was ignored by ACL.
472 We punt by abandoning cutthrough on a reject, like the
473 first-rcpt does. */
474
475 if (done)
476 {
477 address_item * na = store_get(sizeof(address_item));
478 *na = cutthrough.addr;
479 cutthrough.addr = *addr;
480 cutthrough.addr.host_used = &cutthrough.host;
481 cutthrough.addr.next = na;
482
483 cutthrough.nrcpt++;
484 }
485 else
486 {
487 cancel_cutthrough_connection("recipient rejected");
488 if (errno == ETIMEDOUT)
489 {
490 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
491 }
492 else if (errno == 0)
493 {
494 if (*resp == 0)
495 Ustrcpy(resp, US"connection dropped");
496
497 addr->message =
498 string_sprintf("response to \"%s\" from %s [%s] was: %s",
499 big_buffer, host->name, host->address,
500 string_printing(resp));
501
502 addr->user_message =
503 string_sprintf("Callout verification failed:\n%s", resp);
504
505 /* Hard rejection ends the process */
506
507 if (resp[0] == '5') /* Address rejected */
508 {
509 yield = FAIL;
510 done = TRUE;
511 }
512 }
513 }
514 }
515 break;
516 }
517 if (!done)
518 cancel_cutthrough_connection("incompatible connection");
519 }
520
521 /* Now make connections to the hosts and do real callouts. The list of hosts
522 is passed in as an argument. */
523
524 for (host = host_list; host != NULL && !done; host = host->next)
525 {
526 smtp_inblock inblock;
527 smtp_outblock outblock;
528 int host_af;
529 int port = 25;
530 BOOL send_quit = TRUE;
531 uschar *active_hostname = smtp_active_hostname;
532 BOOL lmtp;
533 BOOL smtps;
534 BOOL esmtp;
535 BOOL suppress_tls = FALSE;
536 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
537 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
538 BOOL dane = FALSE;
539 BOOL dane_required;
540 dns_answer tlsa_dnsa;
541 #endif
542 uschar inbuffer[4096];
543 uschar outbuffer[1024];
544 uschar responsebuffer[4096];
545
546 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
547 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
548
549 /* Skip this host if we don't have an IP address for it. */
550
551 if (host->address == NULL)
552 {
553 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
554 host->name);
555 continue;
556 }
557
558 /* Check the overall callout timeout */
559
560 if (time(NULL) - callout_start_time >= callout_overall)
561 {
562 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
563 break;
564 }
565
566 /* Set IPv4 or IPv6 */
567
568 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
569
570 /* Expand and interpret the interface and port strings. The latter will not
571 be used if there is a host-specific port (e.g. from a manualroute router).
572 This has to be delayed till now, because they may expand differently for
573 different hosts. If there's a failure, log it, but carry on with the
574 defaults. */
575
576 deliver_host = host->name;
577 deliver_host_address = host->address;
578 deliver_host_port = host->port;
579 deliver_domain = addr->domain;
580 transport_name = addr->transport->name;
581
582 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
583 US"callout")
584 || !smtp_get_port(tf->port, addr, &port, US"callout")
585 )
586 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
587 addr->message);
588
589 /* Set HELO string according to the protocol */
590 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
591 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
592
593
594 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
595
596 /* Set up the buffer for reading SMTP response packets. */
597
598 inblock.buffer = inbuffer;
599 inblock.buffersize = sizeof(inbuffer);
600 inblock.ptr = inbuffer;
601 inblock.ptrend = inbuffer;
602
603 /* Set up the buffer for holding SMTP commands while pipelining */
604
605 outblock.buffer = outbuffer;
606 outblock.buffersize = sizeof(outbuffer);
607 outblock.ptr = outbuffer;
608 outblock.cmd_count = 0;
609 outblock.authenticating = FALSE;
610
611 /* Connect to the host; on failure, just loop for the next one, but we
612 set the error for the last one. Use the callout_connect timeout. */
613
614 tls_retry_connection:
615
616 /* Reset the parameters of a TLS session */
617 tls_out.cipher = tls_out.peerdn = tls_out.peercert = NULL;
618
619 inblock.sock = outblock.sock =
620 smtp_connect(host, host_af, port, interface, callout_connect,
621 addr->transport);
622 if (inblock.sock < 0)
623 {
624 addr->message = string_sprintf("could not connect to %s [%s]: %s",
625 host->name, host->address, strerror(errno));
626 transport_name = NULL;
627 deliver_host = deliver_host_address = NULL;
628 deliver_domain = save_deliver_domain;
629 continue;
630 }
631
632 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
633 {
634 int rc;
635
636 tls_out.dane_verified = FALSE;
637 tls_out.tlsa_usage = 0;
638
639 dane_required =
640 verify_check_given_host(&ob->hosts_require_dane, host) == OK;
641
642 if (host->dnssec == DS_YES)
643 {
644 if( ( dane_required
645 || verify_check_given_host(&ob->hosts_try_dane, host) == OK
646 )
647 && (rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK
648 )
649 return rc;
650 }
651 else if (dane_required)
652 {
653 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
654 return FAIL;
655 }
656
657 if (dane)
658 ob->tls_tempfail_tryclear = FALSE;
659 }
660 #endif /*DANE*/
661
662 /* Expand the helo_data string to find the host name to use. */
663
664 if (tf->helo_data != NULL)
665 {
666 uschar *s = expand_string(tf->helo_data);
667 if (s == NULL)
668 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
669 "helo_data value for callout: %s", addr->address,
670 expand_string_message);
671 else active_hostname = s;
672 }
673
674 /* Wait for initial response, and send HELO. The smtp_write_command()
675 function leaves its command in big_buffer. This is used in error responses.
676 Initialize it in case the connection is rejected. */
677
678 Ustrcpy(big_buffer, "initial connection");
679
680 /* Unless ssl-on-connect, wait for the initial greeting */
681 smtps_redo_greeting:
682
683 #ifdef SUPPORT_TLS
684 if (!smtps || (smtps && tls_out.active >= 0))
685 #endif
686 {
687 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
688 goto RESPONSE_FAILED;
689
690 #ifndef DISABLE_EVENT
691 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
692 : host->dnssec==DS_NO ? US"no" : NULL;
693 if (event_raise(addr->transport->event_action,
694 US"smtp:connect", responsebuffer))
695 {
696 lookup_dnssec_authenticated = NULL;
697 /* Logging? Debug? */
698 goto RESPONSE_FAILED;
699 }
700 lookup_dnssec_authenticated = NULL;
701 #endif
702 }
703
704 /* Not worth checking greeting line for ESMTP support */
705 if (!(esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK))
706 DEBUG(D_transport)
707 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
708
709 tls_redo_helo:
710
711 #ifdef SUPPORT_TLS
712 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
713 {
714 tls_offered = TRUE;
715 ob->tls_tempfail_tryclear = FALSE;
716 }
717 else /* all other cases */
718 #endif
719
720 { esmtp_retry:
721
722 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
723 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
724 goto SEND_FAILED;
725 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
726 {
727 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
728 {
729 done= FALSE;
730 goto RESPONSE_FAILED;
731 }
732 #ifdef SUPPORT_TLS
733 tls_offered = FALSE;
734 #endif
735 esmtp = FALSE;
736 goto esmtp_retry; /* fallback to HELO */
737 }
738
739 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
740 #ifdef SUPPORT_TLS
741 if (esmtp && !suppress_tls && tls_out.active < 0)
742 {
743 if (regex_STARTTLS == NULL) regex_STARTTLS =
744 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
745
746 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
747 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
748 }
749 else
750 tls_offered = FALSE;
751 #endif
752 }
753
754 /* If TLS is available on this connection attempt to
755 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
756 send another EHLO - the server may give a different answer in secure mode. We
757 use a separate buffer for reading the response to STARTTLS so that if it is
758 negative, the original EHLO data is available for subsequent analysis, should
759 the client not be required to use TLS. If the response is bad, copy the buffer
760 for error analysis. */
761
762 #ifdef SUPPORT_TLS
763 if ( tls_offered
764 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK
765 && verify_check_given_host(&ob->hosts_verify_avoid_tls, host) != OK
766 )
767 {
768 uschar buffer2[4096];
769 if ( !smtps
770 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
771 goto SEND_FAILED;
772
773 /* If there is an I/O error, transmission of this message is deferred. If
774 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
775 false, we also defer. However, if there is a temporary rejection of STARTTLS
776 and tls_tempfail_tryclear is true, or if there is an outright rejection of
777 STARTTLS, we carry on. This means we will try to send the message in clear,
778 unless the host is in hosts_require_tls (tested below). */
779
780 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
781 ob->command_timeout))
782 {
783 if (errno != 0 || buffer2[0] == 0 ||
784 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
785 {
786 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
787 done= FALSE;
788 goto RESPONSE_FAILED;
789 }
790 }
791
792 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
793 else
794 {
795 int oldtimeout = ob->command_timeout;
796 int rc;
797
798 tls_negotiate:
799 ob->command_timeout = callout;
800 rc = tls_client_start(inblock.sock, host, addr, addr->transport
801 # ifdef EXPERIMENTAL_DANE
802 , dane ? &tlsa_dnsa : NULL
803 # endif
804 );
805 ob->command_timeout = oldtimeout;
806
807 /* TLS negotiation failed; give an error. Try in clear on a new
808 connection, if the options permit it for this host. */
809 if (rc != OK)
810 {
811 if (rc == DEFER)
812 {
813 (void)close(inblock.sock);
814 # ifndef DISABLE_EVENT
815 (void) event_raise(addr->transport->event_action,
816 US"tcp:close", NULL);
817 # endif
818 # ifdef EXPERIMENTAL_DANE
819 if (dane)
820 {
821 if (!dane_required)
822 {
823 log_write(0, LOG_MAIN, "DANE attempt failed;"
824 " trying CA-root TLS to %s [%s] (not in hosts_require_dane)",
825 host->name, host->address);
826 dane = FALSE;
827 goto tls_negotiate;
828 }
829 }
830 else
831 # endif
832 if ( ob->tls_tempfail_tryclear
833 && !smtps
834 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
835 )
836 {
837 log_write(0, LOG_MAIN, "TLS session failure:"
838 " delivering unencrypted to %s [%s] (not in hosts_require_tls)",
839 host->name, host->address);
840 suppress_tls = TRUE;
841 goto tls_retry_connection;
842 }
843 }
844
845 /*save_errno = ERRNO_TLSFAILURE;*/
846 /*message = US"failure while setting up TLS session";*/
847 send_quit = FALSE;
848 done= FALSE;
849 goto TLS_FAILED;
850 }
851
852 /* TLS session is set up. Copy info for logging. */
853 addr->cipher = tls_out.cipher;
854 addr->peerdn = tls_out.peerdn;
855
856 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
857 if (smtps)
858 goto smtps_redo_greeting;
859
860 /* For STARTTLS we need to redo EHLO */
861 goto tls_redo_helo;
862 }
863 }
864
865 /* If the host is required to use a secure channel, ensure that we have one. */
866 if (tls_out.active < 0)
867 if (
868 # ifdef EXPERIMENTAL_DANE
869 dane ||
870 # endif
871 verify_check_given_host(&ob->hosts_require_tls, host) == OK
872 )
873 {
874 /*save_errno = ERRNO_TLSREQUIRED;*/
875 log_write(0, LOG_MAIN,
876 "H=%s [%s]: a TLS session is required for this host, but %s",
877 host->name, host->address,
878 tls_offered ? "an attempt to start TLS failed"
879 : "the server did not offer TLS support");
880 done= FALSE;
881 goto TLS_FAILED;
882 }
883
884 #endif /*SUPPORT_TLS*/
885
886 done = TRUE; /* so far so good; have response to HELO */
887
888 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
889
890 /* For now, transport_filter by cutthrough-delivery is not supported */
891 /* Need proper integration with the proper transport mechanism. */
892 if (cutthrough.delivery)
893 {
894 if (addr->transport->filter_command)
895 {
896 cutthrough.delivery = FALSE;
897 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
898 }
899 #ifndef DISABLE_DKIM
900 if (ob->dkim_domain)
901 {
902 cutthrough.delivery = FALSE;
903 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
904 }
905 #endif
906 }
907
908 SEND_FAILED:
909 RESPONSE_FAILED:
910 TLS_FAILED:
911 ;
912 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
913
914 /* Failure to accept HELO is cached; this blocks the whole domain for all
915 senders. I/O errors and defer responses are not cached. */
916
917 if (!done)
918 {
919 *failure_ptr = US"mail"; /* At or before MAIL */
920 if (errno == 0 && responsebuffer[0] == '5')
921 {
922 setflag(addr, af_verify_nsfail);
923 new_domain_record.result = ccache_reject;
924 }
925 }
926
927 #ifdef SUPPORT_I18N
928 else if ( addr->prop.utf8_msg
929 && !addr->prop.utf8_downcvt
930 && !( esmtp
931 && ( regex_UTF8
932 || ( (regex_UTF8 = regex_must_compile(
933 US"\\n250[\\s\\-]SMTPUTF8(\\s|\\n|$)", FALSE, TRUE)),
934 TRUE
935 ) )
936 && ( (utf8_offered = pcre_exec(regex_UTF8, NULL,
937 CS responsebuffer, Ustrlen(responsebuffer),
938 0, PCRE_EOPT, NULL, 0) >= 0)
939 || addr->prop.utf8_downcvt_maybe
940 ) ) )
941 {
942 HDEBUG(D_acl|D_v) debug_printf("utf8 required but not offered\n");
943 errno = ERRNO_UTF8_FWD;
944 setflag(addr, af_verify_nsfail);
945 done = FALSE;
946 }
947 else if ( addr->prop.utf8_msg
948 && (addr->prop.utf8_downcvt || !utf8_offered)
949 && (setflag(addr, af_utf8_downcvt),
950 from_address = string_address_utf8_to_alabel(from_address,
951 &addr->message),
952 addr->message
953 ) )
954 {
955 errno = ERRNO_EXPANDFAIL;
956 setflag(addr, af_verify_nsfail);
957 done = FALSE;
958 }
959 #endif
960
961 /* If we haven't authenticated, but are required to, give up. */
962 /* Try to AUTH */
963
964 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
965 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
966
967 /* Copy AUTH info for logging */
968 ( (addr->authenticator = client_authenticator),
969 (addr->auth_id = client_authenticated_id),
970
971 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
972 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
973 ) &&
974
975 ( (addr->auth_sndr = client_authenticated_sender),
976
977 /* Send the MAIL command */
978 (smtp_write_command(&outblock, FALSE,
979 #ifdef SUPPORT_I18N
980 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
981 ? "MAIL FROM:<%s>%s SMTPUTF8\r\n"
982 :
983 #endif
984 "MAIL FROM:<%s>%s\r\n",
985 from_address, responsebuffer) >= 0)
986 ) &&
987
988 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
989 '2', callout);
990
991 deliver_host = deliver_host_address = NULL;
992 deliver_domain = save_deliver_domain;
993
994 /* If the host does not accept MAIL FROM:<>, arrange to cache this
995 information, but again, don't record anything for an I/O error or a defer. Do
996 not cache rejections of MAIL when a non-empty sender has been used, because
997 that blocks the whole domain for all senders. */
998
999 if (!done)
1000 {
1001 *failure_ptr = US"mail"; /* At or before MAIL */
1002 if (errno == 0 && responsebuffer[0] == '5')
1003 {
1004 setflag(addr, af_verify_nsfail);
1005 if (from_address[0] == 0)
1006 new_domain_record.result = ccache_reject_mfnull;
1007 }
1008 }
1009
1010 /* Otherwise, proceed to check a "random" address (if required), then the
1011 given address, and the postmaster address (if required). Between each check,
1012 issue RSET, because some servers accept only one recipient after MAIL
1013 FROM:<>.
1014
1015 Before doing this, set the result in the domain cache record to "accept",
1016 unless its previous value was ccache_reject_mfnull. In that case, the domain
1017 rejects MAIL FROM:<> and we want to continue to remember that. When that is
1018 the case, we have got here only in the case of a recipient verification with
1019 a non-null sender. */
1020
1021 else
1022 {
1023 const uschar * rcpt_domain = addr->domain;
1024
1025 #ifdef SUPPORT_I18N
1026 uschar * errstr = NULL;
1027 if ( testflag(addr, af_utf8_downcvt)
1028 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
1029 &errstr), errstr)
1030 )
1031 {
1032 addr->message = errstr;
1033 errno = ERRNO_EXPANDFAIL;
1034 setflag(addr, af_verify_nsfail);
1035 done = FALSE;
1036 rcpt_domain = US""; /*XXX errorhandling! */
1037 }
1038 #endif
1039
1040 new_domain_record.result =
1041 (old_domain_cache_result == ccache_reject_mfnull)?
1042 ccache_reject_mfnull: ccache_accept;
1043
1044 /* Do the random local part check first */
1045
1046 if (random_local_part != NULL)
1047 {
1048 uschar randombuffer[1024];
1049 BOOL random_ok =
1050 smtp_write_command(&outblock, FALSE,
1051 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
1052 rcpt_domain) >= 0 &&
1053 smtp_read_response(&inblock, randombuffer,
1054 sizeof(randombuffer), '2', callout);
1055
1056 /* Remember when we last did a random test */
1057
1058 new_domain_record.random_stamp = time(NULL);
1059
1060 /* If accepted, we aren't going to do any further tests below. */
1061
1062 if (random_ok)
1063 new_domain_record.random_result = ccache_accept;
1064
1065 /* Otherwise, cache a real negative response, and get back to the right
1066 state to send RCPT. Unless there's some problem such as a dropped
1067 connection, we expect to succeed, because the commands succeeded above.
1068 However, some servers drop the connection after responding to an
1069 invalid recipient, so on (any) error we drop and remake the connection.
1070 */
1071
1072 else if (errno == 0)
1073 {
1074 /* This would be ok for 1st rcpt a cutthrough, but no way to
1075 handle a subsequent. So refuse to support any */
1076 cancel_cutthrough_connection("random-recipient");
1077
1078 if (randombuffer[0] == '5')
1079 new_domain_record.random_result = ccache_reject;
1080
1081 done =
1082 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1083 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1084 '2', callout) &&
1085
1086 smtp_write_command(&outblock, FALSE,
1087 #ifdef SUPPORT_I18N
1088 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
1089 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
1090 :
1091 #endif
1092 "MAIL FROM:<%s>\r\n",
1093 from_address) >= 0 &&
1094 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1095 '2', callout);
1096
1097 if (!done)
1098 {
1099 HDEBUG(D_acl|D_v)
1100 debug_printf("problem after random/rset/mfrom; reopen conn\n");
1101 random_local_part = NULL;
1102 #ifdef SUPPORT_TLS
1103 tls_close(FALSE, TRUE);
1104 #endif
1105 (void)close(inblock.sock);
1106 #ifndef DISABLE_EVENT
1107 (void) event_raise(addr->transport->event_action,
1108 US"tcp:close", NULL);
1109 #endif
1110 goto tls_retry_connection;
1111 }
1112 }
1113 else done = FALSE; /* Some timeout/connection problem */
1114 } /* Random check */
1115
1116 /* If the host is accepting all local parts, as determined by the "random"
1117 check, we don't need to waste time doing any further checking. */
1118
1119 if (new_domain_record.random_result != ccache_accept && done)
1120 {
1121 /* Get the rcpt_include_affixes flag from the transport if there is one,
1122 but assume FALSE if there is not. */
1123
1124 uschar * rcpt = transport_rcpt_address(addr,
1125 addr->transport ? addr->transport->rcpt_include_affixes : FALSE);
1126
1127 #ifdef SUPPORT_I18N
1128 /*XXX should the conversion be moved into transport_rcpt_address() ? */
1129 uschar * dummy_errstr = NULL;
1130 if ( testflag(addr, af_utf8_downcvt)
1131 && (rcpt = string_address_utf8_to_alabel(rcpt, &dummy_errstr),
1132 dummy_errstr
1133 ) )
1134 {
1135 errno = ERRNO_EXPANDFAIL;
1136 *failure_ptr = US"recipient";
1137 done = FALSE;
1138 }
1139 else
1140 #endif
1141
1142 done =
1143 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
1144 rcpt) >= 0 &&
1145 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1146 '2', callout);
1147
1148 if (done)
1149 new_address_record.result = ccache_accept;
1150 else if (errno == 0 && responsebuffer[0] == '5')
1151 {
1152 *failure_ptr = US"recipient";
1153 new_address_record.result = ccache_reject;
1154 }
1155
1156 /* Do postmaster check if requested; if a full check is required, we
1157 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
1158
1159 if (done && pm_mailfrom != NULL)
1160 {
1161 /* Could possibly shift before main verify, just above, and be ok
1162 for cutthrough. But no way to handle a subsequent rcpt, so just
1163 refuse any */
1164 cancel_cutthrough_connection("postmaster verify");
1165 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
1166
1167 done =
1168 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1169 smtp_read_response(&inblock, responsebuffer,
1170 sizeof(responsebuffer), '2', callout) &&
1171
1172 smtp_write_command(&outblock, FALSE,
1173 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
1174 smtp_read_response(&inblock, responsebuffer,
1175 sizeof(responsebuffer), '2', callout) &&
1176
1177 /* First try using the current domain */
1178
1179 ((
1180 smtp_write_command(&outblock, FALSE,
1181 "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 &&
1182 smtp_read_response(&inblock, responsebuffer,
1183 sizeof(responsebuffer), '2', callout)
1184 )
1185
1186 ||
1187
1188 /* If that doesn't work, and a full check is requested,
1189 try without the domain. */
1190
1191 (
1192 (options & vopt_callout_fullpm) != 0 &&
1193 smtp_write_command(&outblock, FALSE,
1194 "RCPT TO:<postmaster>\r\n") >= 0 &&
1195 smtp_read_response(&inblock, responsebuffer,
1196 sizeof(responsebuffer), '2', callout)
1197 ));
1198
1199 /* Sort out the cache record */
1200
1201 new_domain_record.postmaster_stamp = time(NULL);
1202
1203 if (done)
1204 new_domain_record.postmaster_result = ccache_accept;
1205 else if (errno == 0 && responsebuffer[0] == '5')
1206 {
1207 *failure_ptr = US"postmaster";
1208 setflag(addr, af_verify_pmfail);
1209 new_domain_record.postmaster_result = ccache_reject;
1210 }
1211 }
1212 } /* Random not accepted */
1213 } /* MAIL FROM: accepted */
1214
1215 /* For any failure of the main check, other than a negative response, we just
1216 close the connection and carry on. We can identify a negative response by the
1217 fact that errno is zero. For I/O errors it will be non-zero
1218
1219 Set up different error texts for logging and for sending back to the caller
1220 as an SMTP response. Log in all cases, using a one-line format. For sender
1221 callouts, give a full response to the caller, but for recipient callouts,
1222 don't give the IP address because this may be an internal host whose identity
1223 is not to be widely broadcast. */
1224
1225 if (!done)
1226 {
1227 if (errno == ETIMEDOUT)
1228 {
1229 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1230 send_quit = FALSE;
1231 }
1232 #ifdef SUPPORT_I18N
1233 else if (errno == ERRNO_UTF8_FWD)
1234 {
1235 extern int acl_where; /* src/acl.c */
1236 errno = 0;
1237 addr->message = string_sprintf(
1238 "response to \"%s\" from %s [%s] did not include SMTPUTF8",
1239 big_buffer, host->name, host->address);
1240 addr->user_message = acl_where == ACL_WHERE_RCPT
1241 ? US"533 mailbox name not allowed"
1242 : US"550 mailbox unavailable";
1243 yield = FAIL;
1244 done = TRUE;
1245 }
1246 #endif
1247 else if (errno == 0)
1248 {
1249 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1250
1251 addr->message =
1252 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1253 big_buffer, host->name, host->address,
1254 string_printing(responsebuffer));
1255
1256 addr->user_message = is_recipient?
1257 string_sprintf("Callout verification failed:\n%s", responsebuffer)
1258 :
1259 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1260 host->address, big_buffer, responsebuffer);
1261
1262 /* Hard rejection ends the process */
1263
1264 if (responsebuffer[0] == '5') /* Address rejected */
1265 {
1266 yield = FAIL;
1267 done = TRUE;
1268 }
1269 }
1270 }
1271
1272 /* End the SMTP conversation and close the connection. */
1273
1274 /* Cutthrough - on a successfull connect and recipient-verify with
1275 use-sender and we are 1st rcpt and have no cutthrough conn so far
1276 here is where we want to leave the conn open */
1277 if ( cutthrough.delivery
1278 && rcpt_count == 1
1279 && done
1280 && yield == OK
1281 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
1282 && !random_local_part
1283 && !pm_mailfrom
1284 && cutthrough.fd < 0
1285 && !lmtp
1286 )
1287 {
1288 cutthrough.fd = outblock.sock; /* We assume no buffer in use in the outblock */
1289 cutthrough.nrcpt = 1;
1290 cutthrough.interface = interface;
1291 cutthrough.host = *host;
1292 cutthrough.addr = *addr; /* Save the address_item for later logging */
1293 cutthrough.addr.next = NULL;
1294 cutthrough.addr.host_used = &cutthrough.host;
1295 if (addr->parent)
1296 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1297 *addr->parent;
1298 ctblock.buffer = ctbuffer;
1299 ctblock.buffersize = sizeof(ctbuffer);
1300 ctblock.ptr = ctbuffer;
1301 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1302 ctblock.sock = cutthrough.fd;
1303 }
1304 else
1305 {
1306 /* Ensure no cutthrough on multiple address verifies */
1307 if (options & vopt_callout_recipsender)
1308 cancel_cutthrough_connection("multiple verify calls");
1309 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1310
1311 #ifdef SUPPORT_TLS
1312 tls_close(FALSE, TRUE);
1313 #endif
1314 (void)close(inblock.sock);
1315 #ifndef DISABLE_EVENT
1316 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1317 #endif
1318 }
1319
1320 } /* Loop through all hosts, while !done */
1321 }
1322
1323 /* If we get here with done == TRUE, a successful callout happened, and yield
1324 will be set OK or FAIL according to the response to the RCPT command.
1325 Otherwise, we looped through the hosts but couldn't complete the business.
1326 However, there may be domain-specific information to cache in both cases.
1327
1328 The value of the result field in the new_domain record is ccache_unknown if
1329 there was an error before or with MAIL FROM:, and errno was not zero,
1330 implying some kind of I/O error. We don't want to write the cache in that case.
1331 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1332
1333 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1334 {
1335 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1336 == NULL)
1337 {
1338 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1339 }
1340 else
1341 {
1342 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1343 (int)sizeof(dbdata_callout_cache));
1344 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1345 " result=%d postmaster=%d random=%d\n",
1346 new_domain_record.result,
1347 new_domain_record.postmaster_result,
1348 new_domain_record.random_result);
1349 }
1350 }
1351
1352 /* If a definite result was obtained for the callout, cache it unless caching
1353 is disabled. */
1354
1355 if (done)
1356 {
1357 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1358 {
1359 if (dbm_file == NULL)
1360 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1361 if (dbm_file == NULL)
1362 {
1363 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1364 }
1365 else
1366 {
1367 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1368 (int)sizeof(dbdata_callout_cache_address));
1369 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1370 (new_address_record.result == ccache_accept)? "positive" : "negative");
1371 }
1372 }
1373 } /* done */
1374
1375 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1376 temporary error. If there was only one host, and a response was received, leave
1377 it alone if supplying details. Otherwise, give a generic response. */
1378
1379 else /* !done */
1380 {
1381 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1382 is_recipient? "recipient" : "sender");
1383 yield = DEFER;
1384
1385 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1386
1387 addr->user_message = (!smtp_return_error_details)? dullmsg :
1388 string_sprintf("%s for <%s>.\n"
1389 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1390 "they may be permanently unreachable from this server. In the latter case,\n%s",
1391 dullmsg, addr->address,
1392 is_recipient?
1393 "the address will never be accepted."
1394 :
1395 "you need to change the address or create an MX record for its domain\n"
1396 "if it is supposed to be generally accessible from the Internet.\n"
1397 "Talk to your mail administrator for details.");
1398
1399 /* Force a specific error code */
1400
1401 addr->basic_errno = ERRNO_CALLOUTDEFER;
1402 }
1403
1404 /* Come here from within the cache-reading code on fast-track exit. */
1405
1406 END_CALLOUT:
1407 if (dbm_file != NULL) dbfn_close(dbm_file);
1408 return yield;
1409 }
1410
1411
1412
1413 /* Called after recipient-acl to get a cutthrough connection open when
1414 one was requested and a recipient-verify wasn't subsequently done.
1415 */
1416 void
1417 open_cutthrough_connection( address_item * addr )
1418 {
1419 address_item addr2;
1420
1421 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1422 /* We must use a copy of the address for verification, because it might
1423 get rewritten. */
1424
1425 addr2 = *addr;
1426 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1427 rcpt_count > 1 ? "more" : "start");
1428 (void) verify_address(&addr2, NULL,
1429 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1430 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1431 NULL, NULL, NULL);
1432 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1433 return;
1434 }
1435
1436
1437
1438 /* Send given number of bytes from the buffer */
1439 static BOOL
1440 cutthrough_send(int n)
1441 {
1442 if(cutthrough.fd < 0)
1443 return TRUE;
1444
1445 if(
1446 #ifdef SUPPORT_TLS
1447 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1448 #endif
1449 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1450 )
1451 {
1452 transport_count += n;
1453 ctblock.ptr= ctblock.buffer;
1454 return TRUE;
1455 }
1456
1457 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1458 return FALSE;
1459 }
1460
1461
1462
1463 static BOOL
1464 _cutthrough_puts(uschar * cp, int n)
1465 {
1466 while(n--)
1467 {
1468 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1469 if(!cutthrough_send(ctblock.buffersize))
1470 return FALSE;
1471
1472 *ctblock.ptr++ = *cp++;
1473 }
1474 return TRUE;
1475 }
1476
1477 /* Buffered output of counted data block. Return boolean success */
1478 BOOL
1479 cutthrough_puts(uschar * cp, int n)
1480 {
1481 if (cutthrough.fd < 0) return TRUE;
1482 if (_cutthrough_puts(cp, n)) return TRUE;
1483 cancel_cutthrough_connection("transmit failed");
1484 return FALSE;
1485 }
1486
1487
1488 static BOOL
1489 _cutthrough_flush_send(void)
1490 {
1491 int n= ctblock.ptr-ctblock.buffer;
1492
1493 if(n>0)
1494 if(!cutthrough_send(n))
1495 return FALSE;
1496 return TRUE;
1497 }
1498
1499
1500 /* Send out any bufferred output. Return boolean success. */
1501 BOOL
1502 cutthrough_flush_send(void)
1503 {
1504 if (_cutthrough_flush_send()) return TRUE;
1505 cancel_cutthrough_connection("transmit failed");
1506 return FALSE;
1507 }
1508
1509
1510 BOOL
1511 cutthrough_put_nl(void)
1512 {
1513 return cutthrough_puts(US"\r\n", 2);
1514 }
1515
1516
1517 /* Get and check response from cutthrough target */
1518 static uschar
1519 cutthrough_response(char expect, uschar ** copy)
1520 {
1521 smtp_inblock inblock;
1522 uschar inbuffer[4096];
1523 uschar responsebuffer[4096];
1524
1525 inblock.buffer = inbuffer;
1526 inblock.buffersize = sizeof(inbuffer);
1527 inblock.ptr = inbuffer;
1528 inblock.ptrend = inbuffer;
1529 inblock.sock = cutthrough.fd;
1530 /* this relies on (inblock.sock == tls_out.active) */
1531 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1532 cancel_cutthrough_connection("target timeout on read");
1533
1534 if(copy != NULL)
1535 {
1536 uschar * cp;
1537 *copy = cp = string_copy(responsebuffer);
1538 /* Trim the trailing end of line */
1539 cp += Ustrlen(responsebuffer);
1540 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1541 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1542 }
1543
1544 return responsebuffer[0];
1545 }
1546
1547
1548 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1549 BOOL
1550 cutthrough_predata(void)
1551 {
1552 if(cutthrough.fd < 0)
1553 return FALSE;
1554
1555 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1556 cutthrough_puts(US"DATA\r\n", 6);
1557 cutthrough_flush_send();
1558
1559 /* Assume nothing buffered. If it was it gets ignored. */
1560 return cutthrough_response('3', NULL) == '3';
1561 }
1562
1563
1564 /* fd and use_crlf args only to match write_chunk() */
1565 static BOOL
1566 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1567 {
1568 uschar * s2;
1569 while(s && (s2 = Ustrchr(s, '\n')))
1570 {
1571 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1572 return FALSE;
1573 s = s2+1;
1574 }
1575 return TRUE;
1576 }
1577
1578
1579 /* Buffered send of headers. Return success boolean. */
1580 /* Expands newlines to wire format (CR,NL). */
1581 /* Also sends header-terminating blank line. */
1582 BOOL
1583 cutthrough_headers_send(void)
1584 {
1585 if(cutthrough.fd < 0)
1586 return FALSE;
1587
1588 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1589 but having a separate buffered-output function (for now)
1590 */
1591 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1592
1593 if (!transport_headers_send(&cutthrough.addr, cutthrough.fd,
1594 cutthrough.addr.transport->add_headers,
1595 cutthrough.addr.transport->remove_headers,
1596 &cutthrough_write_chunk, TRUE,
1597 cutthrough.addr.transport->rewrite_rules,
1598 cutthrough.addr.transport->rewrite_existflags))
1599 return FALSE;
1600
1601 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1602 return TRUE;
1603 }
1604
1605
1606 static void
1607 close_cutthrough_connection(const char * why)
1608 {
1609 if(cutthrough.fd >= 0)
1610 {
1611 /* We could be sending this after a bunch of data, but that is ok as
1612 the only way to cancel the transfer in dataphase is to drop the tcp
1613 conn before the final dot.
1614 */
1615 ctblock.ptr = ctbuffer;
1616 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1617 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1618 _cutthrough_flush_send();
1619 /* No wait for response */
1620
1621 #ifdef SUPPORT_TLS
1622 tls_close(FALSE, TRUE);
1623 #endif
1624 (void)close(cutthrough.fd);
1625 cutthrough.fd = -1;
1626 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1627 }
1628 ctblock.ptr = ctbuffer;
1629 }
1630
1631 void
1632 cancel_cutthrough_connection(const char * why)
1633 {
1634 close_cutthrough_connection(why);
1635 cutthrough.delivery = FALSE;
1636 }
1637
1638
1639
1640
1641 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1642 Log an OK response as a transmission.
1643 Close the connection.
1644 Return smtp response-class digit.
1645 */
1646 uschar *
1647 cutthrough_finaldot(void)
1648 {
1649 uschar res;
1650 address_item * addr;
1651 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1652
1653 /* Assume data finshed with new-line */
1654 if( !cutthrough_puts(US".", 1)
1655 || !cutthrough_put_nl()
1656 || !cutthrough_flush_send()
1657 )
1658 return cutthrough.addr.message;
1659
1660 res = cutthrough_response('2', &cutthrough.addr.message);
1661 for (addr = &cutthrough.addr; addr; addr = addr->next)
1662 {
1663 addr->message = cutthrough.addr.message;
1664 switch(res)
1665 {
1666 case '2':
1667 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1668 close_cutthrough_connection("delivered");
1669 break;
1670
1671 case '4':
1672 delivery_log(LOG_MAIN, addr, 0,
1673 US"tmp-reject from cutthrough after DATA:");
1674 break;
1675
1676 case '5':
1677 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1678 US"rejected after DATA:");
1679 break;
1680
1681 default:
1682 break;
1683 }
1684 }
1685 return cutthrough.addr.message;
1686 }
1687
1688
1689
1690 /*************************************************
1691 * Copy error to toplevel address *
1692 *************************************************/
1693
1694 /* This function is used when a verify fails or defers, to ensure that the
1695 failure or defer information is in the original toplevel address. This applies
1696 when an address is redirected to a single new address, and the failure or
1697 deferral happens to the child address.
1698
1699 Arguments:
1700 vaddr the verify address item
1701 addr the final address item
1702 yield FAIL or DEFER
1703
1704 Returns: the value of YIELD
1705 */
1706
1707 static int
1708 copy_error(address_item *vaddr, address_item *addr, int yield)
1709 {
1710 if (addr != vaddr)
1711 {
1712 vaddr->message = addr->message;
1713 vaddr->user_message = addr->user_message;
1714 vaddr->basic_errno = addr->basic_errno;
1715 vaddr->more_errno = addr->more_errno;
1716 vaddr->prop.address_data = addr->prop.address_data;
1717 copyflag(vaddr, addr, af_pass_message);
1718 }
1719 return yield;
1720 }
1721
1722
1723
1724
1725 /**************************************************
1726 * printf that automatically handles TLS if needed *
1727 ***************************************************/
1728
1729 /* This function is used by verify_address() as a substitute for all fprintf()
1730 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1731 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1732 that assumes that we always use the smtp_out FILE* when not using TLS or the
1733 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1734 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1735 fprintf().
1736
1737 Arguments:
1738 f the candidate FILE* to write to
1739 format format string
1740 ... optional arguments
1741
1742 Returns:
1743 nothing
1744 */
1745
1746 static void PRINTF_FUNCTION(2,3)
1747 respond_printf(FILE *f, const char *format, ...)
1748 {
1749 va_list ap;
1750
1751 va_start(ap, format);
1752 if (smtp_out && (f == smtp_out))
1753 smtp_vprintf(format, ap);
1754 else
1755 vfprintf(f, format, ap);
1756 va_end(ap);
1757 }
1758
1759
1760
1761 /*************************************************
1762 * Verify an email address *
1763 *************************************************/
1764
1765 /* This function is used both for verification (-bv and at other times) and
1766 address testing (-bt), which is indicated by address_test_mode being set.
1767
1768 Arguments:
1769 vaddr contains the address to verify; the next field in this block
1770 must be NULL
1771 f if not NULL, write the result to this file
1772 options various option bits:
1773 vopt_fake_sender => this sender verify is not for the real
1774 sender (it was verify=sender=xxxx or an address from a
1775 header line) - rewriting must not change sender_address
1776 vopt_is_recipient => this is a recipient address, otherwise
1777 it's a sender address - this affects qualification and
1778 rewriting and messages from callouts
1779 vopt_qualify => qualify an unqualified address; else error
1780 vopt_expn => called from SMTP EXPN command
1781 vopt_success_on_redirect => when a new address is generated
1782 the verification instantly succeeds
1783
1784 These ones are used by do_callout() -- the options variable
1785 is passed to it.
1786
1787 vopt_callout_fullpm => if postmaster check, do full one
1788 vopt_callout_no_cache => don't use callout cache
1789 vopt_callout_random => do the "random" thing
1790 vopt_callout_recipsender => use real sender for recipient
1791 vopt_callout_recippmaster => use postmaster for recipient
1792
1793 callout if > 0, specifies that callout is required, and gives timeout
1794 for individual commands
1795 callout_overall if > 0, gives overall timeout for the callout function;
1796 if < 0, a default is used (see do_callout())
1797 callout_connect the connection timeout for callouts
1798 se_mailfrom when callout is requested to verify a sender, use this
1799 in MAIL FROM; NULL => ""
1800 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1801 thing and use this as the sender address (may be "")
1802
1803 routed if not NULL, set TRUE if routing succeeded, so we can
1804 distinguish between routing failed and callout failed
1805
1806 Returns: OK address verified
1807 FAIL address failed to verify
1808 DEFER can't tell at present
1809 */
1810
1811 int
1812 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1813 int callout_overall, int callout_connect, uschar *se_mailfrom,
1814 uschar *pm_mailfrom, BOOL *routed)
1815 {
1816 BOOL allok = TRUE;
1817 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1818 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1819 BOOL expn = (options & vopt_expn) != 0;
1820 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1821 int i;
1822 int yield = OK;
1823 int verify_type = expn? v_expn :
1824 address_test_mode? v_none :
1825 is_recipient? v_recipient : v_sender;
1826 address_item *addr_list;
1827 address_item *addr_new = NULL;
1828 address_item *addr_remote = NULL;
1829 address_item *addr_local = NULL;
1830 address_item *addr_succeed = NULL;
1831 uschar **failure_ptr = is_recipient?
1832 &recipient_verify_failure : &sender_verify_failure;
1833 uschar *ko_prefix, *cr;
1834 uschar *address = vaddr->address;
1835 uschar *save_sender;
1836 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1837
1838 /* Clear, just in case */
1839
1840 *failure_ptr = NULL;
1841
1842 /* Set up a prefix and suffix for error message which allow us to use the same
1843 output statements both in EXPN mode (where an SMTP response is needed) and when
1844 debugging with an output file. */
1845
1846 if (expn)
1847 {
1848 ko_prefix = US"553 ";
1849 cr = US"\r";
1850 }
1851 else ko_prefix = cr = US"";
1852
1853 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1854
1855 if (parse_find_at(address) == NULL)
1856 {
1857 if ((options & vopt_qualify) == 0)
1858 {
1859 if (f != NULL)
1860 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1861 ko_prefix, address, cr);
1862 *failure_ptr = US"qualify";
1863 return FAIL;
1864 }
1865 address = rewrite_address_qualify(address, is_recipient);
1866 }
1867
1868 DEBUG(D_verify)
1869 {
1870 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1871 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1872 }
1873
1874 /* Rewrite and report on it. Clear the domain and local part caches - these
1875 may have been set by domains and local part tests during an ACL. */
1876
1877 if (global_rewrite_rules != NULL)
1878 {
1879 uschar *old = address;
1880 address = rewrite_address(address, is_recipient, FALSE,
1881 global_rewrite_rules, rewrite_existflags);
1882 if (address != old)
1883 {
1884 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1885 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1886 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1887 }
1888 }
1889
1890 /* If this is the real sender address, we must update sender_address at
1891 this point, because it may be referred to in the routers. */
1892
1893 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1894 sender_address = address;
1895
1896 /* If the address was rewritten to <> no verification can be done, and we have
1897 to return OK. This rewriting is permitted only for sender addresses; for other
1898 addresses, such rewriting fails. */
1899
1900 if (address[0] == 0) return OK;
1901
1902 /* Flip the legacy TLS-related variables over to the outbound set in case
1903 they're used in the context of a transport used by verification. Reset them
1904 at exit from this routine. */
1905
1906 tls_modify_variables(&tls_out);
1907
1908 /* Save a copy of the sender address for re-instating if we change it to <>
1909 while verifying a sender address (a nice bit of self-reference there). */
1910
1911 save_sender = sender_address;
1912
1913 /* Update the address structure with the possibly qualified and rewritten
1914 address. Set it up as the starting address on the chain of new addresses. */
1915
1916 vaddr->address = address;
1917 addr_new = vaddr;
1918
1919 /* We need a loop, because an address can generate new addresses. We must also
1920 cope with generated pipes and files at the top level. (See also the code and
1921 comment in deliver.c.) However, it is usually the case that the router for
1922 user's .forward files has its verify flag turned off.
1923
1924 If an address generates more than one child, the loop is used only when
1925 full_info is set, and this can only be set locally. Remote enquiries just get
1926 information about the top level address, not anything that it generated. */
1927
1928 while (addr_new != NULL)
1929 {
1930 int rc;
1931 address_item *addr = addr_new;
1932
1933 addr_new = addr->next;
1934 addr->next = NULL;
1935
1936 DEBUG(D_verify)
1937 {
1938 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1939 debug_printf("Considering %s\n", addr->address);
1940 }
1941
1942 /* Handle generated pipe, file or reply addresses. We don't get these
1943 when handling EXPN, as it does only one level of expansion. */
1944
1945 if (testflag(addr, af_pfr))
1946 {
1947 allok = FALSE;
1948 if (f != NULL)
1949 {
1950 BOOL allow;
1951
1952 if (addr->address[0] == '>')
1953 {
1954 allow = testflag(addr, af_allow_reply);
1955 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1956 }
1957 else
1958 {
1959 allow = (addr->address[0] == '|')?
1960 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1961 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1962 }
1963
1964 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1965 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1966 "%s\n", addr->message);
1967 else if (allow)
1968 fprintf(f, "\n transport = %s\n", addr->transport->name);
1969 else
1970 fprintf(f, " *** forbidden ***\n");
1971 }
1972 continue;
1973 }
1974
1975 /* Just in case some router parameter refers to it. */
1976
1977 return_path = (addr->prop.errors_address != NULL)?
1978 addr->prop.errors_address : sender_address;
1979
1980 /* Split the address into domain and local part, handling the %-hack if
1981 necessary, and then route it. While routing a sender address, set
1982 $sender_address to <> because that is what it will be if we were trying to
1983 send a bounce to the sender. */
1984
1985 if (routed != NULL) *routed = FALSE;
1986 if ((rc = deliver_split_address(addr)) == OK)
1987 {
1988 if (!is_recipient) sender_address = null_sender;
1989 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1990 &addr_succeed, verify_type);
1991 sender_address = save_sender; /* Put back the real sender */
1992 }
1993
1994 /* If routing an address succeeded, set the flag that remembers, for use when
1995 an ACL cached a sender verify (in case a callout fails). Then if routing set
1996 up a list of hosts or the transport has a host list, and the callout option
1997 is set, and we aren't in a host checking run, do the callout verification,
1998 and set another flag that notes that a callout happened. */
1999
2000 if (rc == OK)
2001 {
2002 if (routed != NULL) *routed = TRUE;
2003 if (callout > 0)
2004 {
2005 host_item *host_list = addr->host_list;
2006 transport_instance * tp;
2007
2008 /* Make up some data for use in the case where there is no remote
2009 transport. */
2010
2011 transport_feedback tf = {
2012 NULL, /* interface (=> any) */
2013 US"smtp", /* port */
2014 US"smtp", /* protocol */
2015 NULL, /* hosts */
2016 US"$smtp_active_hostname", /* helo_data */
2017 FALSE, /* hosts_override */
2018 FALSE, /* hosts_randomize */
2019 FALSE, /* gethostbyname */
2020 TRUE, /* qualify_single */
2021 FALSE /* search_parents */
2022 };
2023
2024 /* If verification yielded a remote transport, we want to use that
2025 transport's options, so as to mimic what would happen if we were really
2026 sending a message to this address. */
2027
2028 if ((tp = addr->transport) && !tp->info->local)
2029 {
2030 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
2031
2032 /* If the transport has hosts and the router does not, or if the
2033 transport is configured to override the router's hosts, we must build a
2034 host list of the transport's hosts, and find the IP addresses */
2035
2036 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
2037 {
2038 uschar *s;
2039 const uschar *save_deliver_domain = deliver_domain;
2040 uschar *save_deliver_localpart = deliver_localpart;
2041
2042 host_list = NULL; /* Ignore the router's hosts */
2043
2044 deliver_domain = addr->domain;
2045 deliver_localpart = addr->local_part;
2046 s = expand_string(tf.hosts);
2047 deliver_domain = save_deliver_domain;
2048 deliver_localpart = save_deliver_localpart;
2049
2050 if (s == NULL)
2051 {
2052 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
2053 "\"%s\" in %s transport for callout: %s", tf.hosts,
2054 tp->name, expand_string_message);
2055 }
2056 else
2057 {
2058 int flags;
2059 host_item *host, *nexthost;
2060 host_build_hostlist(&host_list, s, tf.hosts_randomize);
2061
2062 /* Just ignore failures to find a host address. If we don't manage
2063 to find any addresses, the callout will defer. Note that more than
2064 one address may be found for a single host, which will result in
2065 additional host items being inserted into the chain. Hence we must
2066 save the next host first. */
2067
2068 flags = HOST_FIND_BY_A;
2069 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2070 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2071
2072 for (host = host_list; host != NULL; host = nexthost)
2073 {
2074 nexthost = host->next;
2075 if (tf.gethostbyname ||
2076 string_is_ip_address(host->name, NULL) != 0)
2077 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
2078 else
2079 {
2080 dnssec_domains * dnssec_domains = NULL;
2081 if (Ustrcmp(tp->driver_name, "smtp") == 0)
2082 {
2083 smtp_transport_options_block * ob =
2084 (smtp_transport_options_block *) tp->options_block;
2085 dnssec_domains = &ob->dnssec;
2086 }
2087
2088 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2089 dnssec_domains, NULL, NULL);
2090 }
2091 }
2092 }
2093 }
2094 }
2095
2096 /* Can only do a callout if we have at least one host! If the callout
2097 fails, it will have set ${sender,recipient}_verify_failure. */
2098
2099 if (host_list != NULL)
2100 {
2101 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
2102 if (host_checking && !host_checking_callout)
2103 {
2104 HDEBUG(D_verify)
2105 debug_printf("... callout omitted by default when host testing\n"
2106 "(Use -bhc if you want the callouts to happen.)\n");
2107 }
2108 else
2109 {
2110 #ifdef SUPPORT_TLS
2111 deliver_set_expansions(addr);
2112 #endif
2113 verify_mode = is_recipient ? US"R" : US"S";
2114 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
2115 callout_connect, options, se_mailfrom, pm_mailfrom);
2116 verify_mode = NULL;
2117 }
2118 }
2119 else
2120 {
2121 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
2122 "transport provided a host list\n");
2123 }
2124 }
2125 }
2126
2127 /* Otherwise, any failure is a routing failure */
2128
2129 else *failure_ptr = US"route";
2130
2131 /* A router may return REROUTED if it has set up a child address as a result
2132 of a change of domain name (typically from widening). In this case we always
2133 want to continue to verify the new child. */
2134
2135 if (rc == REROUTED) continue;
2136
2137 /* Handle hard failures */
2138
2139 if (rc == FAIL)
2140 {
2141 allok = FALSE;
2142 if (f != NULL)
2143 {
2144 address_item *p = addr->parent;
2145
2146 respond_printf(f, "%s%s %s", ko_prefix,
2147 full_info? addr->address : address,
2148 address_test_mode? "is undeliverable" : "failed to verify");
2149 if (!expn && admin_user)
2150 {
2151 if (addr->basic_errno > 0)
2152 respond_printf(f, ": %s", strerror(addr->basic_errno));
2153 if (addr->message != NULL)
2154 respond_printf(f, ": %s", addr->message);
2155 }
2156
2157 /* Show parents iff doing full info */
2158
2159 if (full_info) while (p != NULL)
2160 {
2161 respond_printf(f, "%s\n <-- %s", cr, p->address);
2162 p = p->parent;
2163 }
2164 respond_printf(f, "%s\n", cr);
2165 }
2166 cancel_cutthrough_connection("routing hard fail");
2167
2168 if (!full_info)
2169 {
2170 yield = copy_error(vaddr, addr, FAIL);
2171 goto out;
2172 }
2173 else yield = FAIL;
2174 }
2175
2176 /* Soft failure */
2177
2178 else if (rc == DEFER)
2179 {
2180 allok = FALSE;
2181 if (f != NULL)
2182 {
2183 address_item *p = addr->parent;
2184 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
2185 full_info? addr->address : address);
2186 if (!expn && admin_user)
2187 {
2188 if (addr->basic_errno > 0)
2189 respond_printf(f, ": %s", strerror(addr->basic_errno));
2190 if (addr->message != NULL)
2191 respond_printf(f, ": %s", addr->message);
2192 else if (addr->basic_errno <= 0)
2193 respond_printf(f, ": unknown error");
2194 }
2195
2196 /* Show parents iff doing full info */
2197
2198 if (full_info) while (p != NULL)
2199 {
2200 respond_printf(f, "%s\n <-- %s", cr, p->address);
2201 p = p->parent;
2202 }
2203 respond_printf(f, "%s\n", cr);
2204 }
2205 cancel_cutthrough_connection("routing soft fail");
2206
2207 if (!full_info)
2208 {
2209 yield = copy_error(vaddr, addr, DEFER);
2210 goto out;
2211 }
2212 else if (yield == OK) yield = DEFER;
2213 }
2214
2215 /* If we are handling EXPN, we do not want to continue to route beyond
2216 the top level (whose address is in "address"). */
2217
2218 else if (expn)
2219 {
2220 uschar *ok_prefix = US"250-";
2221 if (addr_new == NULL)
2222 {
2223 if (addr_local == NULL && addr_remote == NULL)
2224 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2225 else
2226 respond_printf(f, "250 <%s>\r\n", address);
2227 }
2228 else while (addr_new != NULL)
2229 {
2230 address_item *addr2 = addr_new;
2231 addr_new = addr2->next;
2232 if (addr_new == NULL) ok_prefix = US"250 ";
2233 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2234 }
2235 yield = OK;
2236 goto out;
2237 }
2238
2239 /* Successful routing other than EXPN. */
2240
2241 else
2242 {
2243 /* Handle successful routing when short info wanted. Otherwise continue for
2244 other (generated) addresses. Short info is the operational case. Full info
2245 can be requested only when debug_selector != 0 and a file is supplied.
2246
2247 There is a conflict between the use of aliasing as an alternate email
2248 address, and as a sort of mailing list. If an alias turns the incoming
2249 address into just one address (e.g. J.Caesar->jc44) you may well want to
2250 carry on verifying the generated address to ensure it is valid when
2251 checking incoming mail. If aliasing generates multiple addresses, you
2252 probably don't want to do this. Exim therefore treats the generation of
2253 just a single new address as a special case, and continues on to verify the
2254 generated address. */
2255
2256 if (!full_info && /* Stop if short info wanted AND */
2257 (((addr_new == NULL || /* No new address OR */
2258 addr_new->next != NULL || /* More than one new address OR */
2259 testflag(addr_new, af_pfr))) /* New address is pfr */
2260 || /* OR */
2261 (addr_new != NULL && /* At least one new address AND */
2262 success_on_redirect))) /* success_on_redirect is set */
2263 {
2264 if (f != NULL) fprintf(f, "%s %s\n", address,
2265 address_test_mode? "is deliverable" : "verified");
2266
2267 /* If we have carried on to verify a child address, we want the value
2268 of $address_data to be that of the child */
2269
2270 vaddr->prop.address_data = addr->prop.address_data;
2271 yield = OK;
2272 goto out;
2273 }
2274 }
2275 } /* Loop for generated addresses */
2276
2277 /* Display the full results of the successful routing, including any generated
2278 addresses. Control gets here only when full_info is set, which requires f not
2279 to be NULL, and this occurs only when a top-level verify is called with the
2280 debugging switch on.
2281
2282 If there are no local and no remote addresses, and there were no pipes, files,
2283 or autoreplies, and there were no errors or deferments, the message is to be
2284 discarded, usually because of the use of :blackhole: in an alias file. */
2285
2286 if (allok && addr_local == NULL && addr_remote == NULL)
2287 {
2288 fprintf(f, "mail to %s is discarded\n", address);
2289 goto out;
2290 }
2291
2292 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2293 while (addr_list)
2294 {
2295 address_item *addr = addr_list;
2296 address_item *p = addr->parent;
2297 transport_instance * tp = addr->transport;
2298
2299 addr_list = addr->next;
2300
2301 fprintf(f, "%s", CS addr->address);
2302 #ifdef EXPERIMENTAL_SRS
2303 if(addr->prop.srs_sender)
2304 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2305 #endif
2306
2307 /* If the address is a duplicate, show something about it. */
2308
2309 if (!testflag(addr, af_pfr))
2310 {
2311 tree_node *tnode;
2312 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2313 fprintf(f, " [duplicate, would not be delivered]");
2314 else tree_add_duplicate(addr->unique, addr);
2315 }
2316
2317 /* Now show its parents */
2318
2319 for (p = addr->parent; p; p = p->parent)
2320 fprintf(f, "\n <-- %s", p->address);
2321 fprintf(f, "\n ");
2322
2323 /* Show router, and transport */
2324
2325 fprintf(f, "router = %s, transport = %s\n",
2326 addr->router->name, tp ? tp->name : US"unset");
2327
2328 /* Show any hosts that are set up by a router unless the transport
2329 is going to override them; fiddle a bit to get a nice format. */
2330
2331 if (addr->host_list && tp && !tp->overrides_hosts)
2332 {
2333 host_item *h;
2334 int maxlen = 0;
2335 int maxaddlen = 0;
2336 for (h = addr->host_list; h; h = h->next)
2337 { /* get max lengths of host names, addrs */
2338 int len = Ustrlen(h->name);
2339 if (len > maxlen) maxlen = len;
2340 len = h->address ? Ustrlen(h->address) : 7;
2341 if (len > maxaddlen) maxaddlen = len;
2342 }
2343 for (h = addr->host_list; h; h = h->next)
2344 {
2345 fprintf(f, " host %-*s ", maxlen, h->name);
2346
2347 if (h->address)
2348 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2349 else if (tp->info->local)
2350 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2351 else
2352 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2353
2354 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2355 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2356 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2357 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2358 fputc('\n', f);
2359 }
2360 }
2361 }
2362
2363 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2364 the -bv or -bt case). */
2365
2366 out:
2367 tls_modify_variables(&tls_in);
2368
2369 return yield;
2370 }
2371
2372
2373
2374
2375 /*************************************************
2376 * Check headers for syntax errors *
2377 *************************************************/
2378
2379 /* This function checks those header lines that contain addresses, and verifies
2380 that all the addresses therein are syntactially correct.
2381
2382 Arguments:
2383 msgptr where to put an error message
2384
2385 Returns: OK
2386 FAIL
2387 */
2388
2389 int
2390 verify_check_headers(uschar **msgptr)
2391 {
2392 header_line *h;
2393 uschar *colon, *s;
2394 int yield = OK;
2395
2396 for (h = header_list; h != NULL && yield == OK; h = h->next)
2397 {
2398 if (h->type != htype_from &&
2399 h->type != htype_reply_to &&
2400 h->type != htype_sender &&
2401 h->type != htype_to &&
2402 h->type != htype_cc &&
2403 h->type != htype_bcc)
2404 continue;
2405
2406 colon = Ustrchr(h->text, ':');
2407 s = colon + 1;
2408 while (isspace(*s)) s++;
2409
2410 /* Loop for multiple addresses in the header, enabling group syntax. Note
2411 that we have to reset this after the header has been scanned. */
2412
2413 parse_allow_group = TRUE;
2414
2415 while (*s != 0)
2416 {
2417 uschar *ss = parse_find_address_end(s, FALSE);
2418 uschar *recipient, *errmess;
2419 int terminator = *ss;
2420 int start, end, domain;
2421
2422 /* Temporarily terminate the string at this point, and extract the
2423 operative address within, allowing group syntax. */
2424
2425 *ss = 0;
2426 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2427 *ss = terminator;
2428
2429 /* Permit an unqualified address only if the message is local, or if the
2430 sending host is configured to be permitted to send them. */
2431
2432 if (recipient != NULL && domain == 0)
2433 {
2434 if (h->type == htype_from || h->type == htype_sender)
2435 {
2436 if (!allow_unqualified_sender) recipient = NULL;
2437 }
2438 else
2439 {
2440 if (!allow_unqualified_recipient) recipient = NULL;
2441 }
2442 if (recipient == NULL) errmess = US"unqualified address not permitted";
2443 }
2444
2445 /* It's an error if no address could be extracted, except for the special
2446 case of an empty address. */
2447
2448 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2449 {
2450 uschar *verb = US"is";
2451 uschar *t = ss;
2452 uschar *tt = colon;
2453 int len;
2454
2455 /* Arrange not to include any white space at the end in the
2456 error message or the header name. */
2457
2458 while (t > s && isspace(t[-1])) t--;
2459 while (tt > h->text && isspace(tt[-1])) tt--;
2460
2461 /* Add the address that failed to the error message, since in a
2462 header with very many addresses it is sometimes hard to spot
2463 which one is at fault. However, limit the amount of address to
2464 quote - cases have been seen where, for example, a missing double
2465 quote in a humungous To: header creates an "address" that is longer
2466 than string_sprintf can handle. */
2467
2468 len = t - s;
2469 if (len > 1024)
2470 {
2471 len = 1024;
2472 verb = US"begins";
2473 }
2474
2475 /* deconst cast ok as we're passing a non-const to string_printing() */
2476 *msgptr = US string_printing(
2477 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2478 errmess, tt - h->text, h->text, verb, len, s));
2479
2480 yield = FAIL;
2481 break; /* Out of address loop */
2482 }
2483
2484 /* Advance to the next address */
2485
2486 s = ss + (terminator? 1:0);
2487 while (isspace(*s)) s++;
2488 } /* Next address */
2489
2490 parse_allow_group = FALSE;
2491 parse_found_group = FALSE;
2492 } /* Next header unless yield has been set FALSE */
2493
2494 return yield;
2495 }
2496
2497
2498 /*************************************************
2499 * Check header names for 8-bit characters *
2500 *************************************************/
2501
2502 /* This function checks for invalid charcters in header names. See
2503 RFC 5322, 2.2. and RFC 6532, 3.
2504
2505 Arguments:
2506 msgptr where to put an error message
2507
2508 Returns: OK
2509 FAIL
2510 */
2511
2512 int
2513 verify_check_header_names_ascii(uschar **msgptr)
2514 {
2515 header_line *h;
2516 uschar *colon, *s;
2517
2518 for (h = header_list; h != NULL; h = h->next)
2519 {
2520 colon = Ustrchr(h->text, ':');
2521 for(s = h->text; s < colon; s++)
2522 {
2523 if ((*s < 33) || (*s > 126))
2524 {
2525 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2526 colon - h->text, h->text);
2527 return FAIL;
2528 }
2529 }
2530 }
2531 return OK;
2532 }
2533
2534 /*************************************************
2535 * Check for blind recipients *
2536 *************************************************/
2537
2538 /* This function checks that every (envelope) recipient is mentioned in either
2539 the To: or Cc: header lines, thus detecting blind carbon copies.
2540
2541 There are two ways of scanning that could be used: either scan the header lines
2542 and tick off the recipients, or scan the recipients and check the header lines.
2543 The original proposed patch did the former, but I have chosen to do the latter,
2544 because (a) it requires no memory and (b) will use fewer resources when there
2545 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2546
2547 Arguments: none
2548 Returns: OK if there are no blind recipients
2549 FAIL if there is at least one blind recipient
2550 */
2551
2552 int
2553 verify_check_notblind(void)
2554 {
2555 int i;
2556 for (i = 0; i < recipients_count; i++)
2557 {
2558 header_line *h;
2559 BOOL found = FALSE;
2560 uschar *address = recipients_list[i].address;
2561
2562 for (h = header_list; !found && h != NULL; h = h->next)
2563 {
2564 uschar *colon, *s;
2565
2566 if (h->type != htype_to && h->type != htype_cc) continue;
2567
2568 colon = Ustrchr(h->text, ':');
2569 s = colon + 1;
2570 while (isspace(*s)) s++;
2571
2572 /* Loop for multiple addresses in the header, enabling group syntax. Note
2573 that we have to reset this after the header has been scanned. */
2574
2575 parse_allow_group = TRUE;
2576
2577 while (*s != 0)
2578 {
2579 uschar *ss = parse_find_address_end(s, FALSE);
2580 uschar *recipient,*errmess;
2581 int terminator = *ss;
2582 int start, end, domain;
2583
2584 /* Temporarily terminate the string at this point, and extract the
2585 operative address within, allowing group syntax. */
2586
2587 *ss = 0;
2588 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2589 *ss = terminator;
2590
2591 /* If we found a valid recipient that has a domain, compare it with the
2592 envelope recipient. Local parts are compared case-sensitively, domains
2593 case-insensitively. By comparing from the start with length "domain", we
2594 include the "@" at the end, which ensures that we are comparing the whole
2595 local part of each address. */
2596
2597 if (recipient != NULL && domain != 0)
2598 {
2599 found = Ustrncmp(recipient, address, domain) == 0 &&
2600 strcmpic(recipient + domain, address + domain) == 0;
2601 if (found) break;
2602 }
2603
2604 /* Advance to the next address */
2605
2606 s = ss + (terminator? 1:0);
2607 while (isspace(*s)) s++;
2608 } /* Next address */
2609
2610 parse_allow_group = FALSE;
2611 parse_found_group = FALSE;
2612 } /* Next header (if found is false) */
2613
2614 if (!found) return FAIL;
2615 } /* Next recipient */
2616
2617 return OK;
2618 }
2619
2620
2621
2622 /*************************************************
2623 * Find if verified sender *
2624 *************************************************/
2625
2626 /* Usually, just a single address is verified as the sender of the message.
2627 However, Exim can be made to verify other addresses as well (often related in
2628 some way), and this is useful in some environments. There may therefore be a
2629 chain of such addresses that have previously been tested. This function finds
2630 whether a given address is on the chain.
2631
2632 Arguments: the address to be verified
2633 Returns: pointer to an address item, or NULL
2634 */
2635
2636 address_item *
2637 verify_checked_sender(uschar *sender)
2638 {
2639 address_item *addr;
2640 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2641 if (Ustrcmp(sender, addr->address) == 0) break;
2642 return addr;
2643 }
2644
2645
2646
2647
2648
2649 /*************************************************
2650 * Get valid header address *
2651 *************************************************/
2652
2653 /* Scan the originator headers of the message, looking for an address that
2654 verifies successfully. RFC 822 says:
2655
2656 o The "Sender" field mailbox should be sent notices of
2657 any problems in transport or delivery of the original
2658 messages. If there is no "Sender" field, then the
2659 "From" field mailbox should be used.
2660
2661 o If the "Reply-To" field exists, then the reply should
2662 go to the addresses indicated in that field and not to
2663 the address(es) indicated in the "From" field.
2664
2665 So we check a Sender field if there is one, else a Reply_to field, else a From
2666 field. As some strange messages may have more than one of these fields,
2667 especially if they are resent- fields, check all of them if there is more than
2668 one.
2669
2670 Arguments:
2671 user_msgptr points to where to put a user error message
2672 log_msgptr points to where to put a log error message
2673 callout timeout for callout check (passed to verify_address())
2674 callout_overall overall callout timeout (ditto)
2675 callout_connect connect callout timeout (ditto)
2676 se_mailfrom mailfrom for verify; NULL => ""
2677 pm_mailfrom sender for pm callout check (passed to verify_address())
2678 options callout options (passed to verify_address())
2679 verrno where to put the address basic_errno
2680
2681 If log_msgptr is set to something without setting user_msgptr, the caller
2682 normally uses log_msgptr for both things.
2683
2684 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2685 FAIL is given if no appropriate headers are found
2686 */
2687
2688 int
2689 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2690 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2691 uschar *pm_mailfrom, int options, int *verrno)
2692 {
2693 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2694 BOOL done = FALSE;
2695 int yield = FAIL;
2696 int i;
2697
2698 for (i = 0; i < 3 && !done; i++)
2699 {
2700 header_line *h;
2701 for (h = header_list; h != NULL && !done; h = h->next)
2702 {
2703 int terminator, new_ok;
2704 uschar *s, *ss, *endname;
2705
2706 if (h->type != header_types[i]) continue;
2707 s = endname = Ustrchr(h->text, ':') + 1;
2708
2709 /* Scan the addresses in the header, enabling group syntax. Note that we
2710 have to reset this after the header has been scanned. */
2711
2712 parse_allow_group = TRUE;
2713
2714 while (*s != 0)
2715 {
2716 address_item *vaddr;
2717
2718 while (isspace(*s) || *s == ',') s++;
2719 if (*s == 0) break; /* End of header */
2720
2721 ss = parse_find_address_end(s, FALSE);
2722
2723 /* The terminator is a comma or end of header, but there may be white
2724 space preceding it (including newline for the last address). Move back
2725 past any white space so we can check against any cached envelope sender
2726 address verifications. */
2727
2728 while (isspace(ss[-1])) ss--;
2729 terminator = *ss;
2730 *ss = 0;
2731
2732 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2733 (int)(endname - h->text), h->text, s);
2734
2735 /* See if we have already verified this address as an envelope sender,
2736 and if so, use the previous answer. */
2737
2738 vaddr = verify_checked_sender(s);
2739
2740 if (vaddr != NULL && /* Previously checked */
2741 (callout <= 0 || /* No callout needed; OR */
2742 vaddr->special_action > 256)) /* Callout was done */
2743 {
2744 new_ok = vaddr->special_action & 255;
2745 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2746 *ss = terminator; /* Restore shortened string */
2747 }
2748
2749 /* Otherwise we run the verification now. We must restore the shortened
2750 string before running the verification, so the headers are correct, in
2751 case there is any rewriting. */
2752
2753 else
2754 {
2755 int start, end, domain;
2756 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2757 &domain, FALSE);
2758
2759 *ss = terminator;
2760
2761 /* If we found an empty address, just carry on with the next one, but
2762 kill the message. */
2763
2764 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2765 {
2766 *log_msgptr = NULL;
2767 s = ss;
2768 continue;
2769 }
2770
2771 /* If verification failed because of a syntax error, fail this
2772 function, and ensure that the failing address gets added to the error
2773 message. */
2774
2775 if (address == NULL)
2776 {
2777 new_ok = FAIL;
2778 while (ss > s && isspace(ss[-1])) ss--;
2779 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2780 "scanning for sender: %s in \"%.*s\"",
2781 endname - h->text, h->text, *log_msgptr, ss - s, s);
2782 yield = FAIL;
2783 done = TRUE;
2784 break;
2785 }
2786
2787 /* Else go ahead with the sender verification. But it isn't *the*
2788 sender of the message, so set vopt_fake_sender to stop sender_address
2789 being replaced after rewriting or qualification. */
2790
2791 else
2792 {
2793 vaddr = deliver_make_addr(address, FALSE);
2794 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2795 callout, callout_overall, callout_connect, se_mailfrom,
2796 pm_mailfrom, NULL);
2797 }
2798 }
2799
2800 /* We now have the result, either newly found, or cached. If we are
2801 giving out error details, set a specific user error. This means that the
2802 last of these will be returned to the user if all three fail. We do not
2803 set a log message - the generic one below will be used. */
2804
2805 if (new_ok != OK)
2806 {
2807 *verrno = vaddr->basic_errno;
2808 if (smtp_return_error_details)
2809 {
2810 *user_msgptr = string_sprintf("Rejected after DATA: "
2811 "could not verify \"%.*s\" header address\n%s: %s",
2812 endname - h->text, h->text, vaddr->address, vaddr->message);
2813 }
2814 }
2815
2816 /* Success or defer */
2817
2818 if (new_ok == OK)
2819 {
2820 yield = OK;
2821 done = TRUE;
2822 break;
2823 }
2824
2825 if (new_ok == DEFER) yield = DEFER;
2826
2827 /* Move on to any more addresses in the header */
2828
2829 s = ss;
2830 } /* Next address */
2831
2832 parse_allow_group = FALSE;
2833 parse_found_group = FALSE;
2834 } /* Next header, unless done */
2835 } /* Next header type unless done */
2836
2837 if (yield == FAIL && *log_msgptr == NULL)
2838 *log_msgptr = US"there is no valid sender in any header line";
2839
2840 if (yield == DEFER && *log_msgptr == NULL)
2841 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2842
2843 return yield;
2844 }
2845
2846
2847
2848
2849 /*************************************************
2850 * Get RFC 1413 identification *
2851 *************************************************/
2852
2853 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2854 the timeout is set to zero, then the query is not done. There may also be lists
2855 of hosts and nets which are exempt. To guard against malefactors sending
2856 non-printing characters which could, for example, disrupt a message's headers,
2857 make sure the string consists of printing characters only.
2858
2859 Argument:
2860 port the port to connect to; usually this is IDENT_PORT (113), but when
2861 running in the test harness with -bh a different value is used.
2862
2863 Returns: nothing
2864
2865 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2866 */
2867
2868 void
2869 verify_get_ident(int port)
2870 {
2871 int sock, host_af, qlen;
2872 int received_sender_port, received_interface_port, n;
2873 uschar *p;
2874 uschar buffer[2048];
2875
2876 /* Default is no ident. Check whether we want to do an ident check for this
2877 host. */
2878
2879 sender_ident = NULL;
2880 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2881 return;
2882
2883 DEBUG(D_ident) debug_printf("doing ident callback\n");
2884
2885 /* Set up a connection to the ident port of the remote host. Bind the local end
2886 to the incoming interface address. If the sender host address is an IPv6
2887 address, the incoming interface address will also be IPv6. */
2888
2889 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2890 sock = ip_socket(SOCK_STREAM, host_af);
2891 if (sock < 0) return;
2892
2893 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2894 {
2895 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2896 strerror(errno));
2897 goto END_OFF;
2898 }
2899
2900 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2901 < 0)
2902 {
2903 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2904 {
2905 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2906 sender_host_address);
2907 }
2908 else
2909 {
2910 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2911 sender_host_address, strerror(errno));
2912 }
2913 goto END_OFF;
2914 }
2915
2916 /* Construct and send the query. */
2917
2918 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2919 qlen = Ustrlen(buffer);
2920 if (send(sock, buffer, qlen, 0) < 0)
2921 {
2922 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2923 goto END_OFF;
2924 }
2925
2926 /* Read a response line. We put it into the rest of the buffer, using several
2927 recv() calls if necessary. */
2928
2929 p = buffer + qlen;
2930
2931 for (;;)
2932 {
2933 uschar *pp;
2934 int count;
2935 int size = sizeof(buffer) - (p - buffer);
2936
2937 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2938 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2939 if (count <= 0) goto END_OFF; /* Read error or EOF */
2940
2941 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2942 generous, and accept a plain \n terminator as well. The only illegal
2943 character is 0. */
2944
2945 for (pp = p; pp < p + count; pp++)
2946 {
2947 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2948 if (*pp == '\n')
2949 {
2950 if (pp[-1] == '\r') pp--;
2951 *pp = 0;
2952 goto GOT_DATA; /* Break out of both loops */
2953 }
2954 }
2955
2956 /* Reached the end of the data without finding \n. Let the loop continue to
2957 read some more, if there is room. */
2958
2959 p = pp;
2960 }
2961
2962 GOT_DATA:
2963
2964 /* We have received a line of data. Check it carefully. It must start with the
2965 same two port numbers that we sent, followed by data as defined by the RFC. For
2966 example,
2967
2968 12345 , 25 : USERID : UNIX :root
2969
2970 However, the amount of white space may be different to what we sent. In the
2971 "osname" field there may be several sub-fields, comma separated. The data we
2972 actually want to save follows the third colon. Some systems put leading spaces
2973 in it - we discard those. */
2974
2975 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2976 &received_interface_port, &n) != 2 ||
2977 received_sender_port != sender_host_port ||
2978 received_interface_port != interface_port)
2979 goto END_OFF;
2980
2981 p = buffer + qlen + n;
2982 while(isspace(*p)) p++;
2983 if (*p++ != ':') goto END_OFF;
2984 while(isspace(*p)) p++;
2985 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2986 p += 6;
2987 while(isspace(*p)) p++;
2988 if (*p++ != ':') goto END_OFF;
2989 while (*p != 0 && *p != ':') p++;
2990 if (*p++ == 0) goto END_OFF;
2991 while(isspace(*p)) p++;
2992 if (*p == 0) goto END_OFF;
2993
2994 /* The rest of the line is the data we want. We turn it into printing
2995 characters when we save it, so that it cannot mess up the format of any logging
2996 or Received: lines into which it gets inserted. We keep a maximum of 127
2997 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2998
2999 sender_ident = US string_printing(string_copyn(p, 127));
3000 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
3001
3002 END_OFF:
3003 (void)close(sock);
3004 return;
3005 }
3006
3007
3008
3009
3010 /*************************************************
3011 * Match host to a single host-list item *
3012 *************************************************/
3013
3014 /* This function compares a host (name or address) against a single item
3015 from a host list. The host name gets looked up if it is needed and is not
3016 already known. The function is called from verify_check_this_host() via
3017 match_check_list(), which is why most of its arguments are in a single block.
3018
3019 Arguments:
3020 arg the argument block (see below)
3021 ss the host-list item
3022 valueptr where to pass back looked up data, or NULL
3023 error for error message when returning ERROR
3024
3025 The block contains:
3026 host_name (a) the host name, or
3027 (b) NULL, implying use sender_host_name and
3028 sender_host_aliases, looking them up if required, or
3029 (c) the empty string, meaning that only IP address matches
3030 are permitted
3031 host_address the host address
3032 host_ipv4 the IPv4 address taken from an IPv6 one
3033
3034 Returns: OK matched
3035 FAIL did not match
3036 DEFER lookup deferred
3037 ERROR (a) failed to find the host name or IP address, or
3038 (b) unknown lookup type specified, or
3039 (c) host name encountered when only IP addresses are
3040 being matched
3041 */
3042
3043 int
3044 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
3045 {
3046 check_host_block *cb = (check_host_block *)arg;
3047 int mlen = -1;
3048 int maskoffset;
3049 BOOL iplookup = FALSE;
3050 BOOL isquery = FALSE;
3051 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
3052 const uschar *t;
3053 uschar *semicolon;
3054 uschar **aliases;
3055
3056 /* Optimize for the special case when the pattern is "*". */
3057
3058 if (*ss == '*' && ss[1] == 0) return OK;
3059
3060 /* If the pattern is empty, it matches only in the case when there is no host -
3061 this can occur in ACL checking for SMTP input using the -bs option. In this
3062 situation, the host address is the empty string. */
3063
3064 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
3065 if (*ss == 0) return FAIL;
3066
3067 /* If the pattern is precisely "@" then match against the primary host name,
3068 provided that host name matching is permitted; if it's "@[]" match against the
3069 local host's IP addresses. */
3070
3071 if (*ss == '@')
3072 {
3073 if (ss[1] == 0)
3074 {
3075 if (isiponly) return ERROR;
3076 ss = primary_hostname;
3077 }
3078 else if (Ustrcmp(ss, "@[]") == 0)
3079 {
3080 ip_address_item *ip;
3081 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
3082 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
3083 return FAIL;
3084 }
3085 }
3086
3087 /* If the pattern is an IP address, optionally followed by a bitmask count, do
3088 a (possibly masked) comparision with the current IP address. */
3089
3090 if (string_is_ip_address(ss, &maskoffset) != 0)
3091 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
3092
3093 /* The pattern is not an IP address. A common error that people make is to omit
3094 one component of an IPv4 address, either by accident, or believing that, for
3095 example, 1.2.3/24 is the same as 1.2.3.0/24, or 1.2.3 is the same as 1.2.3.0,
3096 which it isn't. (Those applications that do accept 1.2.3 as an IP address
3097 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
3098 ancient specification.) To aid in debugging these cases, we give a specific
3099 error if the pattern contains only digits and dots or contains a slash preceded
3100 only by digits and dots (a slash at the start indicates a file name and of
3101 course slashes may be present in lookups, but not preceded only by digits and
3102 dots). */
3103
3104 for (t = ss; isdigit(*t) || *t == '.'; t++);
3105 if (*t == 0 || (*t == '/' && t != ss))
3106 {
3107 *error = US"malformed IPv4 address or address mask";
3108 return ERROR;
3109 }
3110
3111 /* See if there is a semicolon in the pattern */
3112
3113 semicolon = Ustrchr(ss, ';');
3114
3115 /* If we are doing an IP address only match, then all lookups must be IP
3116 address lookups, even if there is no "net-". */
3117
3118 if (isiponly)
3119 {
3120 iplookup = semicolon != NULL;
3121 }
3122
3123 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
3124 a lookup on a masked IP network, in textual form. We obey this code even if we
3125 have already set iplookup, so as to skip over the "net-" prefix and to set the
3126 mask length. The net- stuff really only applies to single-key lookups where the
3127 key is implicit. For query-style lookups the key is specified in the query.
3128 From release 4.30, the use of net- for query style is no longer needed, but we
3129 retain it for backward compatibility. */
3130
3131 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
3132 {
3133 mlen = 0;
3134 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
3135 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
3136 iplookup = (*t++ == '-');
3137 }
3138 else t = ss;
3139
3140 /* Do the IP address lookup if that is indeed what we have */
3141
3142 if (iplookup)
3143 {
3144 int insize;
3145 int search_type;
3146 int incoming[4];
3147 void *handle;
3148 uschar *filename, *key, *result;
3149 uschar buffer[64];
3150
3151 /* Find the search type */
3152
3153 search_type = search_findtype(t, semicolon - t);
3154
3155 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3156 search_error_message);
3157
3158 /* Adjust parameters for the type of lookup. For a query-style lookup, there
3159 is no file name, and the "key" is just the query. For query-style with a file
3160 name, we have to fish the file off the start of the query. For a single-key
3161 lookup, the key is the current IP address, masked appropriately, and
3162 reconverted to text form, with the mask appended. For IPv6 addresses, specify
3163 dot separators instead of colons, except when the lookup type is "iplsearch".
3164 */
3165
3166 if (mac_islookup(search_type, lookup_absfilequery))
3167 {
3168 filename = semicolon + 1;
3169 key = filename;
3170 while (*key != 0 && !isspace(*key)) key++;
3171 filename = string_copyn(filename, key - filename);
3172 while (isspace(*key)) key++;
3173 }
3174 else if (mac_islookup(search_type, lookup_querystyle))
3175 {
3176 filename = NULL;
3177 key = semicolon + 1;
3178 }
3179 else /* Single-key style */
3180 {
3181 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3182 ':' : '.';
3183 insize = host_aton(cb->host_address, incoming);
3184 host_mask(insize, incoming, mlen);
3185 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3186 key = buffer;
3187 filename = semicolon + 1;
3188 }
3189
3190 /* Now do the actual lookup; note that there is no search_close() because
3191 of the caching arrangements. */
3192
3193 handle = search_open(filename, search_type, 0, NULL, NULL);
3194 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3195 search_error_message);
3196 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3197 if (valueptr != NULL) *valueptr = result;
3198 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3199 }
3200
3201 /* The pattern is not an IP address or network reference of any kind. That is,
3202 it is a host name pattern. If this is an IP only match, there's an error in the
3203 host list. */
3204
3205 if (isiponly)
3206 {
3207 *error = US"cannot match host name in match_ip list";
3208 return ERROR;
3209 }
3210
3211 /* Check the characters of the pattern to see if they comprise only letters,
3212 digits, full stops, and hyphens (the constituents of domain names). Allow
3213 underscores, as they are all too commonly found. Sigh. Also, if
3214 allow_utf8_domains is set, allow top-bit characters. */
3215
3216 for (t = ss; *t != 0; t++)
3217 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3218 (!allow_utf8_domains || *t < 128)) break;
3219
3220 /* If the pattern is a complete domain name, with no fancy characters, look up
3221 its IP address and match against that. Note that a multi-homed host will add
3222 items to the chain. */
3223
3224 if (*t == 0)
3225 {
3226 int rc;
3227 host_item h;
3228 h.next = NULL;
3229 h.name = ss;
3230 h.address = NULL;
3231 h.mx = MX_NONE;
3232
3233 /* Using byname rather than bydns here means we cannot determine dnssec
3234 status. On the other hand it is unclear how that could be either
3235 propagated up or enforced. */
3236
3237 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3238 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3239 {
3240 host_item *hh;
3241 for (hh = &h; hh != NULL; hh = hh->next)
3242 {
3243 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3244 }
3245 return FAIL;
3246 }
3247 if (rc == HOST_FIND_AGAIN) return DEFER;
3248 *error = string_sprintf("failed to find IP address for %s", ss);
3249 return ERROR;
3250 }
3251
3252 /* Almost all subsequent comparisons require the host name, and can be done
3253 using the general string matching function. When this function is called for
3254 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3255 must use sender_host_name and its aliases, looking them up if necessary. */
3256
3257 if (cb->host_name != NULL) /* Explicit host name given */
3258 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3259 valueptr);
3260
3261 /* Host name not given; in principle we need the sender host name and its
3262 aliases. However, for query-style lookups, we do not need the name if the
3263 query does not contain $sender_host_name. From release 4.23, a reference to
3264 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3265 on spec. */
3266
3267 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3268 {
3269 const uschar *affix;
3270 int partial, affixlen, starflags, id;
3271
3272 *semicolon = 0;
3273 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3274 *semicolon=';';
3275
3276 if (id < 0) /* Unknown lookup type */
3277 {
3278 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3279 search_error_message, ss);
3280 return DEFER;
3281 }
3282 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3283 }
3284
3285 if (isquery)
3286 {
3287 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3288 {
3289 case OK: return OK;
3290 case DEFER: return DEFER;
3291 default: return FAIL;
3292 }
3293 }
3294
3295 /* Not a query-style lookup; must ensure the host name is present, and then we
3296 do a check on the name and all its aliases. */
3297
3298 if (sender_host_name == NULL)
3299 {
3300 HDEBUG(D_host_lookup)
3301 debug_printf("sender host name required, to match against %s\n", ss);
3302 if (host_lookup_failed || host_name_lookup() != OK)
3303 {
3304 *error = string_sprintf("failed to find host name for %s",
3305 sender_host_address);;
3306 return ERROR;
3307 }
3308 host_build_sender_fullhost();
3309 }
3310
3311 /* Match on the sender host name, using the general matching function */
3312
3313 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3314 valueptr))
3315 {
3316 case OK: return OK;
3317 case DEFER: return DEFER;
3318 }
3319
3320 /* If there are aliases, try matching on them. */
3321
3322 aliases = sender_host_aliases;
3323 while (*aliases != NULL)
3324 {
3325 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3326 {
3327 case OK: return OK;
3328 case DEFER: return DEFER;
3329 }
3330 }
3331 return FAIL;
3332 }
3333
3334
3335
3336
3337 /*************************************************
3338 * Check a specific host matches a host list *
3339 *************************************************/
3340
3341 /* This function is passed a host list containing items in a number of
3342 different formats and the identity of a host. Its job is to determine whether
3343 the given host is in the set of hosts defined by the list. The host name is
3344 passed as a pointer so that it can be looked up if needed and not already
3345 known. This is commonly the case when called from verify_check_host() to check
3346 an incoming connection. When called from elsewhere the host name should usually
3347 be set.
3348
3349 This function is now just a front end to match_check_list(), which runs common
3350 code for scanning a list. We pass it the check_host() function to perform a
3351 single test.
3352
3353 Arguments:
3354 listptr pointer to the host list
3355 cache_bits pointer to cache for named lists, or NULL
3356 host_name the host name or NULL, implying use sender_host_name and
3357 sender_host_aliases, looking them up if required
3358 host_address the IP address
3359 valueptr if not NULL, data from a lookup is passed back here
3360
3361 Returns: OK if the host is in the defined set
3362 FAIL if the host is not in the defined set,
3363 DEFER if a data lookup deferred (not a host lookup)
3364
3365 If the host name was needed in order to make a comparison, and could not be
3366 determined from the IP address, the result is FAIL unless the item
3367 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3368
3369 int
3370 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3371 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3372 {
3373 int rc;
3374 unsigned int *local_cache_bits = cache_bits;
3375 const uschar *save_host_address = deliver_host_address;
3376 check_host_block cb;
3377 cb.host_name = host_name;
3378 cb.host_address = host_address;
3379
3380 if (valueptr != NULL) *valueptr = NULL;
3381
3382 /* If the host address starts off ::ffff: it is an IPv6 address in
3383 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3384 addresses. */
3385
3386 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3387 host_address + 7 : host_address;
3388
3389 /* During the running of the check, put the IP address into $host_address. In
3390 the case of calls from the smtp transport, it will already be there. However,
3391 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3392 the safe side, any existing setting is preserved, though as I write this
3393 (November 2004) I can't see any cases where it is actually needed. */
3394
3395 deliver_host_address = host_address;
3396 rc = match_check_list(
3397 listptr, /* the list */
3398 0, /* separator character */
3399 &hostlist_anchor, /* anchor pointer */
3400 &local_cache_bits, /* cache pointer */
3401 check_host, /* function for testing */
3402 &cb, /* argument for function */
3403 MCL_HOST, /* type of check */
3404 (host_address == sender_host_address)?
3405 US"host" : host_address, /* text for debugging */
3406 valueptr); /* where to pass back data */
3407 deliver_host_address = save_host_address;
3408 return rc;
3409 }
3410
3411
3412
3413
3414 /*************************************************
3415 * Check the given host item matches a list *
3416 *************************************************/
3417 int
3418 verify_check_given_host(uschar **listptr, host_item *host)
3419 {
3420 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3421 }
3422
3423 /*************************************************
3424 * Check the remote host matches a list *
3425 *************************************************/
3426
3427 /* This is a front end to verify_check_this_host(), created because checking
3428 the remote host is a common occurrence. With luck, a good compiler will spot
3429 the tail recursion and optimize it. If there's no host address, this is
3430 command-line SMTP input - check against an empty string for the address.
3431
3432 Arguments:
3433 listptr pointer to the host list
3434
3435 Returns: the yield of verify_check_this_host(),
3436 i.e. OK, FAIL, or DEFER
3437 */
3438
3439 int
3440 verify_check_host(uschar **listptr)
3441 {
3442 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3443 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3444 }
3445
3446
3447
3448
3449
3450 /*************************************************
3451 * Invert an IP address *
3452 *************************************************/
3453
3454 /* Originally just used for DNS xBL lists, now also used for the
3455 reverse_ip expansion operator.
3456
3457 Arguments:
3458 buffer where to put the answer
3459 address the address to invert
3460 */
3461
3462 void
3463 invert_address(uschar *buffer, uschar *address)
3464 {
3465 int bin[4];
3466 uschar *bptr = buffer;
3467
3468 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3469 to the IPv4 part only. */
3470
3471 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3472
3473 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3474 always 1. */
3475
3476 if (host_aton(address, bin) == 1)
3477 {
3478 int i;
3479 int x = bin[0];
3480 for (i = 0; i < 4; i++)
3481 {
3482 sprintf(CS bptr, "%d.", x & 255);
3483 while (*bptr) bptr++;
3484 x >>= 8;
3485 }
3486 }
3487
3488 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3489 in any DNS black lists, and the format in which they will be looked up is
3490 unknown. This is just a guess. */
3491
3492 #if HAVE_IPV6
3493 else
3494 {
3495 int i, j;
3496 for (j = 3; j >= 0; j--)
3497 {
3498 int x = bin[j];
3499 for (i = 0; i < 8; i++)
3500 {
3501 sprintf(CS bptr, "%x.", x & 15);
3502 while (*bptr) bptr++;
3503 x >>= 4;
3504 }
3505 }
3506 }
3507 #endif
3508
3509 /* Remove trailing period -- this is needed so that both arbitrary
3510 dnsbl keydomains and inverted addresses may be combined with the
3511 same format string, "%s.%s" */
3512
3513 *(--bptr) = 0;
3514 }
3515
3516
3517
3518 /*************************************************
3519 * Perform a single dnsbl lookup *
3520 *************************************************/
3521
3522 /* This function is called from verify_check_dnsbl() below. It is also called
3523 recursively from within itself when domain and domain_txt are different
3524 pointers, in order to get the TXT record from the alternate domain.
3525
3526 Arguments:
3527 domain the outer dnsbl domain
3528 domain_txt alternate domain to lookup TXT record on success; when the
3529 same domain is to be used, domain_txt == domain (that is,
3530 the pointers must be identical, not just the text)
3531 keydomain the current keydomain (for debug message)
3532 prepend subdomain to lookup (like keydomain, but
3533 reversed if IP address)
3534 iplist the list of matching IP addresses, or NULL for "any"
3535 bitmask true if bitmask matching is wanted
3536 match_type condition for 'succeed' result
3537 0 => Any RR in iplist (=)
3538 1 => No RR in iplist (!=)
3539 2 => All RRs in iplist (==)
3540 3 => Some RRs not in iplist (!==)
3541 the two bits are defined as MT_NOT and MT_ALL
3542 defer_return what to return for a defer
3543
3544 Returns: OK if lookup succeeded
3545 FAIL if not
3546 */
3547
3548 static int
3549 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3550 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3551 int defer_return)
3552 {
3553 dns_answer dnsa;
3554 dns_scan dnss;
3555 tree_node *t;
3556 dnsbl_cache_block *cb;
3557 int old_pool = store_pool;
3558 uschar query[256]; /* DNS domain max length */
3559
3560 /* Construct the specific query domainname */
3561
3562 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3563 {
3564 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3565 "(ignored): %s...", query);
3566 return FAIL;
3567 }
3568
3569 /* Look for this query in the cache. */
3570
3571 if ( (t = tree_search(dnsbl_cache, query))
3572 && (cb = t->data.ptr)->expiry > time(NULL)
3573 )
3574
3575 /* Previous lookup was cached */
3576
3577 {
3578 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3579 }
3580
3581 /* If not cached from a previous lookup, we must do a DNS lookup, and
3582 cache the result in permanent memory. */
3583
3584 else
3585 {
3586 uint ttl = 3600;
3587
3588 store_pool = POOL_PERM;
3589
3590 if (t)
3591 {
3592 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3593 }
3594
3595 else
3596 { /* Set up a tree entry to cache the lookup */
3597 t = store_get(sizeof(tree_node) + Ustrlen(query));
3598 Ustrcpy(t->name, query);
3599 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3600 (void)tree_insertnode(&dnsbl_cache, t);
3601 }
3602
3603 /* Do the DNS loopup . */
3604
3605 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3606 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3607 cb->text_set = FALSE;
3608 cb->text = NULL;
3609 cb->rhs = NULL;
3610
3611 /* If the lookup succeeded, cache the RHS address. The code allows for
3612 more than one address - this was for complete generality and the possible
3613 use of A6 records. However, A6 records have been reduced to experimental
3614 status (August 2001) and may die out. So they may never get used at all,
3615 let alone in dnsbl records. However, leave the code here, just in case.
3616
3617 Quite apart from one A6 RR generating multiple addresses, there are DNS
3618 lists that return more than one A record, so we must handle multiple
3619 addresses generated in that way as well.
3620
3621 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3622 or some suitably far-future time if none were found. */
3623
3624 if (cb->rc == DNS_SUCCEED)
3625 {
3626 dns_record *rr;
3627 dns_address **addrp = &(cb->rhs);
3628 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3629 rr;
3630 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3631 {
3632 if (rr->type == T_A)
3633 {
3634 dns_address *da = dns_address_from_rr(&dnsa, rr);
3635 if (da)
3636 {
3637 *addrp = da;
3638 while (da->next != NULL) da = da->next;
3639 addrp = &(da->next);
3640 if (ttl > rr->ttl) ttl = rr->ttl;
3641 }
3642 }
3643 }
3644
3645 /* If we didn't find any A records, change the return code. This can
3646 happen when there is a CNAME record but there are no A records for what
3647 it points to. */
3648
3649 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3650 }
3651
3652 cb->expiry = time(NULL)+ttl;
3653 store_pool = old_pool;
3654 }
3655
3656 /* We now have the result of the DNS lookup, either newly done, or cached
3657 from a previous call. If the lookup succeeded, check against the address
3658 list if there is one. This may be a positive equality list (introduced by
3659 "="), a negative equality list (introduced by "!="), a positive bitmask
3660 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3661
3662 if (cb->rc == DNS_SUCCEED)
3663 {
3664 dns_address *da = NULL;
3665 uschar *addlist = cb->rhs->address;
3666
3667 /* For A and AAAA records, there may be multiple addresses from multiple
3668 records. For A6 records (currently not expected to be used) there may be
3669 multiple addresses from a single record. */
3670
3671 for (da = cb->rhs->next; da != NULL; da = da->next)
3672 addlist = string_sprintf("%s, %s", addlist, da->address);
3673
3674 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3675 query, addlist);
3676
3677 /* Address list check; this can be either for equality, or via a bitmask.
3678 In the latter case, all the bits must match. */
3679
3680 if (iplist != NULL)
3681 {
3682 for (da = cb->rhs; da != NULL; da = da->next)
3683 {
3684 int ipsep = ',';
3685 uschar ip[46];
3686 const uschar *ptr = iplist;
3687 uschar *res;
3688
3689 /* Handle exact matching */
3690
3691 if (!bitmask)
3692 {
3693 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3694 {
3695 if (Ustrcmp(CS da->address, ip) == 0) break;
3696 }
3697 }
3698
3699 /* Handle bitmask matching */
3700
3701 else
3702 {
3703 int address[4];
3704 int mask = 0;
3705
3706 /* At present, all known DNS blocking lists use A records, with
3707 IPv4 addresses on the RHS encoding the information they return. I
3708 wonder if this will linger on as the last vestige of IPv4 when IPv6
3709 is ubiquitous? Anyway, for now we use paranoia code to completely
3710 ignore IPv6 addresses. The default mask is 0, which always matches.
3711 We change this only for IPv4 addresses in the list. */
3712
3713 if (host_aton(da->address, address) == 1) mask = address[0];
3714
3715 /* Scan the returned addresses, skipping any that are IPv6 */
3716
3717 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3718 {
3719 if (host_aton(ip, address) != 1) continue;
3720 if ((address[0] & mask) == address[0]) break;
3721 }
3722 }
3723
3724 /* If either
3725
3726 (a) An IP address in an any ('=') list matched, or
3727 (b) No IP address in an all ('==') list matched
3728
3729 then we're done searching. */
3730
3731 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3732 }
3733
3734 /* If da == NULL, either
3735
3736 (a) No IP address in an any ('=') list matched, or
3737 (b) An IP address in an all ('==') list didn't match
3738
3739 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3740 the list. */
3741
3742 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3743 {
3744 HDEBUG(D_dnsbl)
3745 {
3746 uschar *res = NULL;
3747 switch(match_type)
3748 {
3749 case 0:
3750 res = US"was no match";
3751 break;
3752 case MT_NOT:
3753 res = US"was an exclude match";
3754 break;
3755 case MT_ALL:
3756 res = US"was an IP address that did not match";
3757 break;
3758 case MT_NOT|MT_ALL:
3759 res = US"were no IP addresses that did not match";
3760 break;
3761 }
3762 debug_printf("=> but we are not accepting this block class because\n");
3763 debug_printf("=> there %s for %s%c%s\n",
3764 res,
3765 ((match_type & MT_ALL) == 0)? "" : "=",
3766 bitmask? '&' : '=', iplist);
3767 }
3768 return FAIL;
3769 }
3770 }
3771
3772 /* Either there was no IP list, or the record matched, implying that the
3773 domain is on the list. We now want to find a corresponding TXT record. If an
3774 alternate domain is specified for the TXT record, call this function
3775 recursively to look that up; this has the side effect of re-checking that
3776 there is indeed an A record at the alternate domain. */
3777
3778 if (domain_txt != domain)
3779 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3780 FALSE, match_type, defer_return);
3781
3782 /* If there is no alternate domain, look up a TXT record in the main domain
3783 if it has not previously been cached. */
3784
3785 if (!cb->text_set)
3786 {
3787 cb->text_set = TRUE;
3788 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3789 {
3790 dns_record *rr;
3791 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3792 rr != NULL;
3793 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3794 if (rr->type == T_TXT) break;
3795 if (rr != NULL)
3796 {
3797 int len = (rr->data)[0];
3798 if (len > 511) len = 127;
3799 store_pool = POOL_PERM;
3800 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3801 store_pool = old_pool;
3802 }
3803 }
3804 }
3805
3806 dnslist_value = addlist;
3807 dnslist_text = cb->text;
3808 return OK;
3809 }
3810
3811 /* There was a problem with the DNS lookup */
3812
3813 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3814 {
3815 log_write(L_dnslist_defer, LOG_MAIN,
3816 "DNS list lookup defer (probably timeout) for %s: %s", query,
3817 (defer_return == OK)? US"assumed in list" :
3818 (defer_return == FAIL)? US"assumed not in list" :
3819 US"returned DEFER");
3820 return defer_return;
3821 }
3822
3823 /* No entry was found in the DNS; continue for next domain */
3824
3825 HDEBUG(D_dnsbl)
3826 {
3827 debug_printf("DNS lookup for %s failed\n", query);
3828 debug_printf("=> that means %s is not listed at %s\n",
3829 keydomain, domain);
3830 }
3831
3832 return FAIL;
3833 }
3834
3835
3836
3837
3838 /*************************************************
3839 * Check host against DNS black lists *
3840 *************************************************/
3841
3842 /* This function runs checks against a list of DNS black lists, until one
3843 matches. Each item on the list can be of the form
3844
3845 domain=ip-address/key
3846
3847 The domain is the right-most domain that is used for the query, for example,
3848 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3849 if the DNS lookup returns a matching IP address. Several addresses may be
3850 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3851
3852 If no key is given, what is looked up in the domain is the inverted IP address
3853 of the current client host. If a key is given, it is used to construct the
3854 domain for the lookup. For example:
3855
3856 dsn.rfc-ignorant.org/$sender_address_domain
3857
3858 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3859 then we check for a TXT record for an error message, and if found, save its
3860 value in $dnslist_text. We also cache everything in a tree, to optimize
3861 multiple lookups.
3862
3863 The TXT record is normally looked up in the same domain as the A record, but
3864 when many lists are combined in a single DNS domain, this will not be a very
3865 specific message. It is possible to specify a different domain for looking up
3866 TXT records; this is given before the main domain, comma-separated. For
3867 example:
3868
3869 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3870 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3871
3872 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3873
3874 Note: an address for testing RBL is 192.203.178.39
3875 Note: an address for testing DUL is 192.203.178.4
3876 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3877
3878 Arguments:
3879 listptr the domain/address/data list
3880
3881 Returns: OK successful lookup (i.e. the address is on the list), or
3882 lookup deferred after +include_unknown
3883 FAIL name not found, or no data found for the given type, or
3884 lookup deferred after +exclude_unknown (default)
3885 DEFER lookup failure, if +defer_unknown was set
3886 */
3887
3888 int
3889 verify_check_dnsbl(const uschar **listptr)
3890 {
3891 int sep = 0;
3892 int defer_return = FAIL;
3893 const uschar *list = *listptr;
3894 uschar *domain;
3895 uschar *s;
3896 uschar buffer[1024];
3897 uschar revadd[128]; /* Long enough for IPv6 address */
3898
3899 /* Indicate that the inverted IP address is not yet set up */
3900
3901 revadd[0] = 0;
3902
3903 /* In case this is the first time the DNS resolver is being used. */
3904
3905 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3906
3907 /* Loop through all the domains supplied, until something matches */
3908
3909 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3910 {
3911 int rc;
3912 BOOL bitmask = FALSE;
3913 int match_type = 0;
3914 uschar *domain_txt;
3915 uschar *comma;
3916 uschar *iplist;
3917 uschar *key;
3918
3919 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3920
3921 /* Deal with special values that change the behaviour on defer */
3922
3923 if (domain[0] == '+')
3924 {
3925 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3926 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3927 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3928 else
3929 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3930 domain);
3931 continue;
3932 }
3933
3934 /* See if there's explicit data to be looked up */
3935
3936 key = Ustrchr(domain, '/');
3937 if (key != NULL) *key++ = 0;
3938
3939 /* See if there's a list of addresses supplied after the domain name. This is
3940 introduced by an = or a & character; if preceded by = we require all matches
3941 and if preceded by ! we invert the result. */
3942
3943 iplist = Ustrchr(domain, '=');
3944 if (iplist == NULL)
3945 {
3946 bitmask = TRUE;
3947 iplist = Ustrchr(domain, '&');
3948 }
3949
3950 if (iplist != NULL) /* Found either = or & */
3951 {
3952 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3953 {
3954 match_type |= MT_NOT;
3955 iplist[-1] = 0;
3956 }
3957
3958 *iplist++ = 0; /* Terminate domain, move on */
3959
3960 /* If we found = (bitmask == FALSE), check for == or =& */
3961
3962 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3963 {
3964 bitmask = *iplist++ == '&';
3965 match_type |= MT_ALL;
3966 }
3967 }
3968
3969 /* If there is a comma in the domain, it indicates that a second domain for
3970 looking up TXT records is provided, before the main domain. Otherwise we must
3971 set domain_txt == domain. */
3972
3973 domain_txt = domain;
3974 comma = Ustrchr(domain, ',');
3975 if (comma != NULL)
3976 {
3977 *comma++ = 0;
3978 domain = comma;
3979 }
3980
3981 /* Check that what we have left is a sensible domain name. There is no reason
3982 why these domains should in fact use the same syntax as hosts and email
3983 domains, but in practice they seem to. However, there is little point in
3984 actually causing an error here, because that would no doubt hold up incoming
3985 mail. Instead, I'll just log it. */
3986
3987 for (s = domain; *s != 0; s++)
3988 {
3989 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3990 {
3991 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3992 "strange characters - is this right?", domain);
3993 break;
3994 }
3995 }
3996
3997 /* Check the alternate domain if present */
3998
3999 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
4000 {
4001 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
4002 {
4003 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
4004 "strange characters - is this right?", domain_txt);
4005 break;
4006 }
4007 }
4008
4009 /* If there is no key string, construct the query by adding the domain name
4010 onto the inverted host address, and perform a single DNS lookup. */
4011
4012 if (key == NULL)
4013 {
4014 if (sender_host_address == NULL) return FAIL; /* can never match */
4015 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
4016 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
4017 iplist, bitmask, match_type, defer_return);
4018 if (rc == OK)
4019 {
4020 dnslist_domain = string_copy(domain_txt);
4021 dnslist_matched = string_copy(sender_host_address);
4022 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4023 sender_host_address, dnslist_domain);
4024 }
4025 if (rc != FAIL) return rc; /* OK or DEFER */
4026 }
4027
4028 /* If there is a key string, it can be a list of domains or IP addresses to
4029 be concatenated with the main domain. */
4030
4031 else
4032 {
4033 int keysep = 0;
4034 BOOL defer = FALSE;
4035 uschar *keydomain;
4036 uschar keybuffer[256];
4037 uschar keyrevadd[128];
4038
4039 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
4040 sizeof(keybuffer))) != NULL)
4041 {
4042 uschar *prepend = keydomain;
4043
4044 if (string_is_ip_address(keydomain, NULL) != 0)
4045 {
4046 invert_address(keyrevadd, keydomain);
4047 prepend = keyrevadd;
4048 }
4049