d890f5fc60a96d54a4c1c948aec6c06754d75f2e
[exim.git] / src / src / verify.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
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 int yield = OK;
159 int old_domain_cache_result = ccache_accept;
160 BOOL done = FALSE;
161 uschar *address_key;
162 uschar *from_address;
163 uschar *random_local_part = NULL;
164 const uschar *save_deliver_domain = deliver_domain;
165 uschar **failure_ptr = options & vopt_is_recipient
166 ? &recipient_verify_failure : &sender_verify_failure;
167 open_db dbblock;
168 open_db *dbm_file = NULL;
169 dbdata_callout_cache new_domain_record;
170 dbdata_callout_cache_address new_address_record;
171 host_item *host;
172 time_t callout_start_time;
173 uschar peer_offered = 0;
174
175 new_domain_record.result = ccache_unknown;
176 new_domain_record.postmaster_result = ccache_unknown;
177 new_domain_record.random_result = ccache_unknown;
178
179 memset(&new_address_record, 0, sizeof(new_address_record));
180
181 /* For a recipient callout, the key used for the address cache record must
182 include the sender address if we are using the real sender in the callout,
183 because that may influence the result of the callout. */
184
185 address_key = addr->address;
186 from_address = US"";
187
188 if (options & vopt_is_recipient)
189 {
190 if (options & vopt_callout_recipsender)
191 {
192 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
193 from_address = sender_address;
194 if (cutthrough.delivery) options |= vopt_callout_no_cache;
195 }
196 else if (options & vopt_callout_recippmaster)
197 {
198 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
199 qualify_domain_sender);
200 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
201 }
202 }
203
204 /* For a sender callout, we must adjust the key if the mailfrom address is not
205 empty. */
206
207 else
208 {
209 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
210 if (from_address[0] != 0)
211 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
212 }
213
214 /* Open the callout cache database, it it exists, for reading only at this
215 stage, unless caching has been disabled. */
216
217 if (options & vopt_callout_no_cache)
218 {
219 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
220 }
221 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
222 {
223 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
224 }
225
226 /* If a cache database is available see if we can avoid the need to do an
227 actual callout by making use of previously-obtained data. */
228
229 if (dbm_file != NULL)
230 {
231 dbdata_callout_cache_address *cache_address_record;
232 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
233 addr->domain, US"domain",
234 callout_cache_domain_positive_expire,
235 callout_cache_domain_negative_expire);
236
237 /* If an unexpired cache record was found for this domain, see if the callout
238 process can be short-circuited. */
239
240 if (cache_record != NULL)
241 {
242 /* In most cases, if an early command (up to and including MAIL FROM:<>)
243 was rejected, there is no point carrying on. The callout fails. However, if
244 we are doing a recipient verification with use_sender or use_postmaster
245 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
246 will be using a non-empty sender. We have to remember this situation so as
247 not to disturb the cached domain value if this whole verification succeeds
248 (we don't want it turning into "accept"). */
249
250 old_domain_cache_result = cache_record->result;
251
252 if (cache_record->result == ccache_reject ||
253 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
254 {
255 setflag(addr, af_verify_nsfail);
256 HDEBUG(D_verify)
257 debug_printf("callout cache: domain gave initial rejection, or "
258 "does not accept HELO or MAIL FROM:<>\n");
259 setflag(addr, af_verify_nsfail);
260 addr->user_message = US"(result of an earlier callout reused).";
261 yield = FAIL;
262 *failure_ptr = US"mail";
263 goto END_CALLOUT;
264 }
265
266 /* If a previous check on a "random" local part was accepted, we assume
267 that the server does not do any checking on local parts. There is therefore
268 no point in doing the callout, because it will always be successful. If a
269 random check previously failed, arrange not to do it again, but preserve
270 the data in the new record. If a random check is required but hasn't been
271 done, skip the remaining cache processing. */
272
273 if (options & vopt_callout_random) switch(cache_record->random_result)
274 {
275 case ccache_accept:
276 HDEBUG(D_verify)
277 debug_printf("callout cache: domain accepts random addresses\n");
278 goto END_CALLOUT; /* Default yield is OK */
279
280 case ccache_reject:
281 HDEBUG(D_verify)
282 debug_printf("callout cache: domain rejects random addresses\n");
283 options &= ~vopt_callout_random;
284 new_domain_record.random_result = ccache_reject;
285 new_domain_record.random_stamp = cache_record->random_stamp;
286 break;
287
288 default:
289 HDEBUG(D_verify)
290 debug_printf("callout cache: need to check random address handling "
291 "(not cached or cache expired)\n");
292 goto END_CACHE;
293 }
294
295 /* If a postmaster check is requested, but there was a previous failure,
296 there is again no point in carrying on. If a postmaster check is required,
297 but has not been done before, we are going to have to do a callout, so skip
298 remaining cache processing. */
299
300 if (pm_mailfrom != NULL)
301 {
302 if (cache_record->postmaster_result == ccache_reject)
303 {
304 setflag(addr, af_verify_pmfail);
305 HDEBUG(D_verify)
306 debug_printf("callout cache: domain does not accept "
307 "RCPT TO:<postmaster@domain>\n");
308 yield = FAIL;
309 *failure_ptr = US"postmaster";
310 setflag(addr, af_verify_pmfail);
311 addr->user_message = US"(result of earlier verification reused).";
312 goto END_CALLOUT;
313 }
314 if (cache_record->postmaster_result == ccache_unknown)
315 {
316 HDEBUG(D_verify)
317 debug_printf("callout cache: need to check RCPT "
318 "TO:<postmaster@domain> (not cached or cache expired)\n");
319 goto END_CACHE;
320 }
321
322 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
323 postmaster check if the address itself has to be checked. Also ensure
324 that the value in the cache record is preserved (with its old timestamp).
325 */
326
327 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
328 "TO:<postmaster@domain>\n");
329 pm_mailfrom = NULL;
330 new_domain_record.postmaster_result = ccache_accept;
331 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
332 }
333 }
334
335 /* We can't give a result based on information about the domain. See if there
336 is an unexpired cache record for this specific address (combined with the
337 sender address if we are doing a recipient callout with a non-empty sender).
338 */
339
340 cache_address_record = (dbdata_callout_cache_address *)
341 get_callout_cache_record(dbm_file,
342 address_key, US"address",
343 callout_cache_positive_expire,
344 callout_cache_negative_expire);
345
346 if (cache_address_record != NULL)
347 {
348 if (cache_address_record->result == ccache_accept)
349 {
350 HDEBUG(D_verify)
351 debug_printf("callout cache: address record is positive\n");
352 }
353 else
354 {
355 HDEBUG(D_verify)
356 debug_printf("callout cache: address record is negative\n");
357 addr->user_message = US"Previous (cached) callout verification failure";
358 *failure_ptr = US"recipient";
359 yield = FAIL;
360 }
361 goto END_CALLOUT;
362 }
363
364 /* Close the cache database while we actually do the callout for real. */
365
366 END_CACHE:
367 dbfn_close(dbm_file);
368 dbm_file = NULL;
369 }
370
371 if (!addr->transport)
372 {
373 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
374 }
375 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
376 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
377 addr->transport->name, addr->transport->driver_name);
378 else
379 {
380 smtp_transport_options_block *ob =
381 (smtp_transport_options_block *)addr->transport->options_block;
382
383 /* The information wasn't available in the cache, so we have to do a real
384 callout and save the result in the cache for next time, unless no_cache is set,
385 or unless we have a previously cached negative random result. If we are to test
386 with a random local part, ensure that such a local part is available. If not,
387 log the fact, but carry on without randomming. */
388
389 if (options & vopt_callout_random && callout_random_local_part != NULL)
390 if (!(random_local_part = expand_string(callout_random_local_part)))
391 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
392 "callout_random_local_part: %s", expand_string_message);
393
394 /* Default the connect and overall callout timeouts if not set, and record the
395 time we are starting so that we can enforce it. */
396
397 if (callout_overall < 0) callout_overall = 4 * callout;
398 if (callout_connect < 0) callout_connect = callout;
399 callout_start_time = time(NULL);
400
401 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
402 output because a callout might take some time. When PIPELINING is active and
403 there are many recipients, the total time for doing lots of callouts can add up
404 and cause the client to time out. So in this case we forgo the PIPELINING
405 optimization. */
406
407 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
408
409 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
410 and we are holding a cutthrough conn open, we can just append the rcpt to
411 that conn for verification purposes (and later delivery also). Simplest
412 coding means skipping this whole loop and doing the append separately.
413
414 We will need to remember it has been appended so that rcpt-acl tail code
415 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
416 */
417
418 /* Can we re-use an open cutthrough connection? */
419 if ( cutthrough.fd >= 0
420 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
421 == vopt_callout_recipsender
422 && !random_local_part
423 && !pm_mailfrom
424 )
425 {
426 if (addr->transport == cutthrough.addr.transport)
427 for (host = host_list; host; host = host->next)
428 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
429 {
430 int host_af;
431 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
432 int port = 25;
433
434 deliver_host = host->name;
435 deliver_host_address = host->address;
436 deliver_host_port = host->port;
437 deliver_domain = addr->domain;
438 transport_name = addr->transport->name;
439
440 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
441
442 if (!smtp_get_interface(tf->interface, host_af, addr, &interface,
443 US"callout") ||
444 !smtp_get_port(tf->port, addr, &port, US"callout"))
445 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
446 addr->message);
447
448 if ( ( interface == cutthrough.interface
449 || ( interface
450 && cutthrough.interface
451 && Ustrcmp(interface, cutthrough.interface) == 0
452 ) )
453 && port == cutthrough.host.port
454 )
455 {
456 uschar * resp = NULL;
457
458 /* Match! Send the RCPT TO, append the addr, set done */
459 done =
460 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
461 transport_rcpt_address(addr,
462 (addr->transport == NULL)? FALSE :
463 addr->transport->rcpt_include_affixes)) >= 0 &&
464 cutthrough_response('2', &resp) == '2';
465
466 /* This would go horribly wrong if a callout fail was ignored by ACL.
467 We punt by abandoning cutthrough on a reject, like the
468 first-rcpt does. */
469
470 if (done)
471 {
472 address_item * na = store_get(sizeof(address_item));
473 *na = cutthrough.addr;
474 cutthrough.addr = *addr;
475 cutthrough.addr.host_used = &cutthrough.host;
476 cutthrough.addr.next = na;
477
478 cutthrough.nrcpt++;
479 }
480 else
481 {
482 cancel_cutthrough_connection("recipient rejected");
483 if (!resp || errno == ETIMEDOUT)
484 {
485 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
486 }
487 else if (errno == 0)
488 {
489 if (*resp == 0)
490 Ustrcpy(resp, US"connection dropped");
491
492 addr->message =
493 string_sprintf("response to \"%s\" from %s [%s] was: %s",
494 big_buffer, host->name, host->address,
495 string_printing(resp));
496
497 addr->user_message =
498 string_sprintf("Callout verification failed:\n%s", resp);
499
500 /* Hard rejection ends the process */
501
502 if (resp[0] == '5') /* Address rejected */
503 {
504 yield = FAIL;
505 done = TRUE;
506 }
507 }
508 }
509 }
510 break;
511 }
512 if (!done)
513 cancel_cutthrough_connection("incompatible connection");
514 }
515
516 /* Now make connections to the hosts and do real callouts. The list of hosts
517 is passed in as an argument. */
518
519 for (host = host_list; host != NULL && !done; host = host->next)
520 {
521 smtp_inblock inblock;
522 smtp_outblock outblock;
523 int host_af;
524 int port = 25;
525 BOOL send_quit = TRUE;
526 uschar *active_hostname = smtp_active_hostname;
527 BOOL lmtp;
528 BOOL smtps;
529 BOOL esmtp;
530 BOOL suppress_tls = FALSE;
531 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
532 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
533 BOOL dane = FALSE;
534 BOOL dane_required;
535 dns_answer tlsa_dnsa;
536 #endif
537 uschar inbuffer[4096];
538 uschar outbuffer[1024];
539 uschar responsebuffer[4096];
540 uschar * size_str;
541
542 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
543 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
544
545 /* Skip this host if we don't have an IP address for it. */
546
547 if (host->address == NULL)
548 {
549 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
550 host->name);
551 continue;
552 }
553
554 /* Check the overall callout timeout */
555
556 if (time(NULL) - callout_start_time >= callout_overall)
557 {
558 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
559 break;
560 }
561
562 /* Set IPv4 or IPv6 */
563
564 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
565
566 /* Expand and interpret the interface and port strings. The latter will not
567 be used if there is a host-specific port (e.g. from a manualroute router).
568 This has to be delayed till now, because they may expand differently for
569 different hosts. If there's a failure, log it, but carry on with the
570 defaults. */
571
572 deliver_host = host->name;
573 deliver_host_address = host->address;
574 deliver_host_port = host->port;
575 deliver_domain = addr->domain;
576 transport_name = addr->transport->name;
577
578 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
579 US"callout")
580 || !smtp_get_port(tf->port, addr, &port, US"callout")
581 )
582 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
583 addr->message);
584
585 /* Set HELO string according to the protocol */
586 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
587 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
588
589
590 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
591
592 /* Set up the buffer for reading SMTP response packets. */
593
594 inblock.buffer = inbuffer;
595 inblock.buffersize = sizeof(inbuffer);
596 inblock.ptr = inbuffer;
597 inblock.ptrend = inbuffer;
598
599 /* Set up the buffer for holding SMTP commands while pipelining */
600
601 outblock.buffer = outbuffer;
602 outblock.buffersize = sizeof(outbuffer);
603 outblock.ptr = outbuffer;
604 outblock.cmd_count = 0;
605 outblock.authenticating = FALSE;
606
607 /* Connect to the host; on failure, just loop for the next one, but we
608 set the error for the last one. Use the callout_connect timeout. */
609
610 tls_retry_connection:
611
612 /* Reset the parameters of a TLS session */
613 tls_out.cipher = tls_out.peerdn = tls_out.peercert = NULL;
614
615 inblock.sock = outblock.sock =
616 smtp_connect(host, host_af, port, interface, callout_connect,
617 addr->transport);
618 if (inblock.sock < 0)
619 {
620 addr->message = string_sprintf("could not connect to %s [%s]: %s",
621 host->name, host->address, strerror(errno));
622 transport_name = NULL;
623 deliver_host = deliver_host_address = NULL;
624 deliver_domain = save_deliver_domain;
625 continue;
626 }
627
628 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
629 {
630 int rc;
631
632 tls_out.dane_verified = FALSE;
633 tls_out.tlsa_usage = 0;
634
635 dane_required =
636 verify_check_given_host(&ob->hosts_require_dane, host) == OK;
637
638 if (host->dnssec == DS_YES)
639 {
640 if( dane_required
641 || verify_check_given_host(&ob->hosts_try_dane, host) == OK
642 )
643 {
644 if ((rc = tlsa_lookup(host, &tlsa_dnsa, dane_required)) != OK)
645 return rc;
646 dane = TRUE;
647 }
648 }
649 else if (dane_required)
650 {
651 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
652 return FAIL;
653 }
654
655 if (dane)
656 ob->tls_tempfail_tryclear = FALSE;
657 }
658 #endif /*DANE*/
659
660 /* Expand the helo_data string to find the host name to use. */
661
662 if (tf->helo_data != NULL)
663 {
664 uschar *s = expand_string(tf->helo_data);
665 if (s == NULL)
666 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
667 "helo_data value for callout: %s", addr->address,
668 expand_string_message);
669 else active_hostname = s;
670 }
671
672 /* Wait for initial response, and send HELO. The smtp_write_command()
673 function leaves its command in big_buffer. This is used in error responses.
674 Initialize it in case the connection is rejected. */
675
676 Ustrcpy(big_buffer, "initial connection");
677
678 /* Unless ssl-on-connect, wait for the initial greeting */
679 smtps_redo_greeting:
680
681 #ifdef SUPPORT_TLS
682 if (!smtps || (smtps && tls_out.active >= 0))
683 #endif
684 {
685 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
686 goto RESPONSE_FAILED;
687
688 #ifndef DISABLE_EVENT
689 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
690 : host->dnssec==DS_NO ? US"no" : NULL;
691 if (event_raise(addr->transport->event_action,
692 US"smtp:connect", responsebuffer))
693 {
694 lookup_dnssec_authenticated = NULL;
695 /* Logging? Debug? */
696 goto RESPONSE_FAILED;
697 }
698 lookup_dnssec_authenticated = NULL;
699 #endif
700 }
701
702 /* Not worth checking greeting line for ESMTP support */
703 if (!(esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK))
704 DEBUG(D_transport)
705 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
706
707 tls_redo_helo:
708
709 #ifdef SUPPORT_TLS
710 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
711 {
712 peer_offered &= ~PEER_OFFERED_TLS;
713 ob->tls_tempfail_tryclear = FALSE;
714 }
715 else /* all other cases */
716 #endif
717
718 { esmtp_retry:
719
720 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
721 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
722 goto SEND_FAILED;
723 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
724 {
725 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
726 {
727 done= FALSE;
728 goto RESPONSE_FAILED;
729 }
730 #ifdef SUPPORT_TLS
731 peer_offered &= ~PEER_OFFERED_TLS;
732 #endif
733 esmtp = FALSE;
734 goto esmtp_retry; /* fallback to HELO */
735 }
736
737 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
738
739 peer_offered = esmtp
740 ? ehlo_response(responsebuffer, sizeof(responsebuffer),
741 (!suppress_tls && tls_out.active < 0 ? PEER_OFFERED_TLS : 0)
742 | 0 /* no IGNQ */
743 | 0 /* no PRDR */
744 #ifdef SUPPORT_I18N
745 | (addr->prop.utf8_msg && !addr->prop.utf8_downcvt
746 ? PEER_OFFERED_UTF8 : 0)
747 #endif
748 | 0 /* no DSN */
749 | 0 /* no PIPE */
750
751 /* only care about SIZE if we have size from inbound */
752 | (message_size > 0 && ob->size_addition >= 0
753 ? PEER_OFFERED_SIZE : 0)
754 )
755 : 0;
756 }
757
758 size_str = peer_offered & PEER_OFFERED_SIZE
759 ? string_sprintf(" SIZE=%d", message_size + ob->size_addition) : US"";
760
761 #ifdef SUPPORT_TLS
762 smtp_peer_options |= peer_offered & PEER_OFFERED_TLS;
763 #endif
764
765 /* If TLS is available on this connection attempt to
766 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
767 send another EHLO - the server may give a different answer in secure mode. We
768 use a separate buffer for reading the response to STARTTLS so that if it is
769 negative, the original EHLO data is available for subsequent analysis, should
770 the client not be required to use TLS. If the response is bad, copy the buffer
771 for error analysis. */
772
773 #ifdef SUPPORT_TLS
774 if ( peer_offered & PEER_OFFERED_TLS
775 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK
776 && verify_check_given_host(&ob->hosts_verify_avoid_tls, host) != OK
777 )
778 {
779 uschar buffer2[4096];
780 if ( !smtps
781 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
782 goto SEND_FAILED;
783
784 /* If there is an I/O error, transmission of this message is deferred. If
785 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
786 false, we also defer. However, if there is a temporary rejection of STARTTLS
787 and tls_tempfail_tryclear is true, or if there is an outright rejection of
788 STARTTLS, we carry on. This means we will try to send the message in clear,
789 unless the host is in hosts_require_tls (tested below). */
790
791 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
792 ob->command_timeout))
793 {
794 if ( errno != 0
795 || buffer2[0] == 0
796 || buffer2[0] == '4' && !ob->tls_tempfail_tryclear
797 )
798 {
799 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
800 done= FALSE;
801 goto RESPONSE_FAILED;
802 }
803 }
804
805 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
806 else
807 {
808 int oldtimeout = ob->command_timeout;
809 int rc;
810
811 tls_negotiate:
812 ob->command_timeout = callout;
813 rc = tls_client_start(inblock.sock, host, addr, addr->transport
814 # ifdef EXPERIMENTAL_DANE
815 , dane ? &tlsa_dnsa : NULL
816 # endif
817 );
818 ob->command_timeout = oldtimeout;
819
820 /* TLS negotiation failed; give an error. Try in clear on a new
821 connection, if the options permit it for this host. */
822 if (rc != OK)
823 {
824 if (rc == DEFER)
825 {
826 (void)close(inblock.sock);
827 # ifndef DISABLE_EVENT
828 (void) event_raise(addr->transport->event_action,
829 US"tcp:close", NULL);
830 # endif
831 if ( ob->tls_tempfail_tryclear
832 && !smtps
833 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
834 )
835 {
836 log_write(0, LOG_MAIN, "TLS session failure:"
837 " delivering unencrypted to %s [%s] (not in hosts_require_tls)",
838 host->name, host->address);
839 suppress_tls = TRUE;
840 goto tls_retry_connection;
841 }
842 }
843
844 /*save_errno = ERRNO_TLSFAILURE;*/
845 /*message = US"failure while setting up TLS session";*/
846 send_quit = FALSE;
847 done= FALSE;
848 goto TLS_FAILED;
849 }
850
851 /* TLS session is set up. Copy info for logging. */
852 addr->cipher = tls_out.cipher;
853 addr->peerdn = tls_out.peerdn;
854
855 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
856 if (smtps)
857 goto smtps_redo_greeting;
858
859 /* For STARTTLS we need to redo EHLO */
860 goto tls_redo_helo;
861 }
862 }
863
864 /* If the host is required to use a secure channel, ensure that we have one. */
865 if (tls_out.active < 0)
866 if (
867 # ifdef EXPERIMENTAL_DANE
868 dane ||
869 # endif
870 verify_check_given_host(&ob->hosts_require_tls, host) == OK
871 )
872 {
873 /*save_errno = ERRNO_TLSREQUIRED;*/
874 log_write(0, LOG_MAIN,
875 "H=%s [%s]: a TLS session is required for this host, but %s",
876 host->name, host->address,
877 peer_offered & PEER_OFFERED_TLS
878 ? "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 /* For now, transport_filter by cutthrough-delivery is not supported */
889 /* Need proper integration with the proper transport mechanism. */
890 if (cutthrough.delivery)
891 {
892 #ifndef DISABLE_DKIM
893 uschar * s;
894 #endif
895 if (addr->transport->filter_command)
896 {
897 cutthrough.delivery = FALSE;
898 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
899 }
900 #ifndef DISABLE_DKIM
901 else if ((s = ob->dkim.dkim_domain) && (s = expand_string(s)) && *s)
902 {
903 cutthrough.delivery = FALSE;
904 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
905 }
906 #endif
907 }
908
909 SEND_FAILED:
910 RESPONSE_FAILED:
911 TLS_FAILED:
912 ;
913 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
914
915 /* Failure to accept HELO is cached; this blocks the whole domain for all
916 senders. I/O errors and defer responses are not cached. */
917
918 if (!done)
919 {
920 *failure_ptr = US"mail"; /* At or before MAIL */
921 if (errno == 0 && responsebuffer[0] == '5')
922 {
923 setflag(addr, af_verify_nsfail);
924 new_domain_record.result = ccache_reject;
925 }
926 }
927
928 #ifdef SUPPORT_I18N
929 else if ( addr->prop.utf8_msg
930 && !addr->prop.utf8_downcvt
931 && !(peer_offered & PEER_OFFERED_UTF8)
932 )
933 {
934 HDEBUG(D_acl|D_v) debug_printf("utf8 required but not offered\n");
935 errno = ERRNO_UTF8_FWD;
936 setflag(addr, af_verify_nsfail);
937 done = FALSE;
938 }
939 else if ( addr->prop.utf8_msg
940 && (addr->prop.utf8_downcvt || !(peer_offered & PEER_OFFERED_UTF8))
941 && (setflag(addr, af_utf8_downcvt),
942 from_address = string_address_utf8_to_alabel(from_address,
943 &addr->message),
944 addr->message
945 ) )
946 {
947 errno = ERRNO_EXPANDFAIL;
948 setflag(addr, af_verify_nsfail);
949 done = FALSE;
950 }
951 #endif
952
953 /* If we haven't authenticated, but are required to, give up. */
954 /* Try to AUTH */
955
956 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
957 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
958
959 /* Copy AUTH info for logging */
960 ( (addr->authenticator = client_authenticator),
961 (addr->auth_id = client_authenticated_id),
962
963 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
964 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
965 ) &&
966
967 ( (addr->auth_sndr = client_authenticated_sender),
968
969 /* Send the MAIL command */
970 (smtp_write_command(&outblock, FALSE,
971 #ifdef SUPPORT_I18N
972 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
973 ? "MAIL FROM:<%s>%s%s SMTPUTF8\r\n"
974 :
975 #endif
976 "MAIL FROM:<%s>%s%s\r\n",
977 from_address, responsebuffer, size_str) >= 0)
978 ) &&
979
980 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
981 '2', callout);
982
983 deliver_host = deliver_host_address = NULL;
984 deliver_domain = save_deliver_domain;
985
986 /* If the host does not accept MAIL FROM:<>, arrange to cache this
987 information, but again, don't record anything for an I/O error or a defer. Do
988 not cache rejections of MAIL when a non-empty sender has been used, because
989 that blocks the whole domain for all senders. */
990
991 if (!done)
992 {
993 *failure_ptr = US"mail"; /* At or before MAIL */
994 if (errno == 0 && responsebuffer[0] == '5')
995 {
996 setflag(addr, af_verify_nsfail);
997 if (from_address[0] == 0)
998 new_domain_record.result = ccache_reject_mfnull;
999 }
1000 }
1001
1002 /* Otherwise, proceed to check a "random" address (if required), then the
1003 given address, and the postmaster address (if required). Between each check,
1004 issue RSET, because some servers accept only one recipient after MAIL
1005 FROM:<>.
1006
1007 Before doing this, set the result in the domain cache record to "accept",
1008 unless its previous value was ccache_reject_mfnull. In that case, the domain
1009 rejects MAIL FROM:<> and we want to continue to remember that. When that is
1010 the case, we have got here only in the case of a recipient verification with
1011 a non-null sender. */
1012
1013 else
1014 {
1015 const uschar * rcpt_domain = addr->domain;
1016
1017 #ifdef SUPPORT_I18N
1018 uschar * errstr = NULL;
1019 if ( testflag(addr, af_utf8_downcvt)
1020 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
1021 &errstr), errstr)
1022 )
1023 {
1024 addr->message = errstr;
1025 errno = ERRNO_EXPANDFAIL;
1026 setflag(addr, af_verify_nsfail);
1027 done = FALSE;
1028 rcpt_domain = US""; /*XXX errorhandling! */
1029 }
1030 #endif
1031
1032 new_domain_record.result =
1033 (old_domain_cache_result == ccache_reject_mfnull)?
1034 ccache_reject_mfnull: ccache_accept;
1035
1036 /* Do the random local part check first */
1037
1038 if (random_local_part != NULL)
1039 {
1040 uschar randombuffer[1024];
1041 BOOL random_ok =
1042 smtp_write_command(&outblock, FALSE,
1043 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
1044 rcpt_domain) >= 0 &&
1045 smtp_read_response(&inblock, randombuffer,
1046 sizeof(randombuffer), '2', callout);
1047
1048 /* Remember when we last did a random test */
1049
1050 new_domain_record.random_stamp = time(NULL);
1051
1052 /* If accepted, we aren't going to do any further tests below. */
1053
1054 if (random_ok)
1055 new_domain_record.random_result = ccache_accept;
1056
1057 /* Otherwise, cache a real negative response, and get back to the right
1058 state to send RCPT. Unless there's some problem such as a dropped
1059 connection, we expect to succeed, because the commands succeeded above.
1060 However, some servers drop the connection after responding to an
1061 invalid recipient, so on (any) error we drop and remake the connection.
1062 */
1063
1064 else if (errno == 0)
1065 {
1066 /* This would be ok for 1st rcpt a cutthrough, but no way to
1067 handle a subsequent. So refuse to support any */
1068 cancel_cutthrough_connection("random-recipient");
1069
1070 if (randombuffer[0] == '5')
1071 new_domain_record.random_result = ccache_reject;
1072
1073 done =
1074 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1075 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1076 '2', callout) &&
1077
1078 smtp_write_command(&outblock, FALSE,
1079 #ifdef SUPPORT_I18N
1080 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
1081 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
1082 :
1083 #endif
1084 "MAIL FROM:<%s>\r\n",
1085 from_address) >= 0 &&
1086 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1087 '2', callout);
1088
1089 if (!done)
1090 {
1091 HDEBUG(D_acl|D_v)
1092 debug_printf("problem after random/rset/mfrom; reopen conn\n");
1093 random_local_part = NULL;
1094 #ifdef SUPPORT_TLS
1095 tls_close(FALSE, TRUE);
1096 #endif
1097 (void)close(inblock.sock);
1098 #ifndef DISABLE_EVENT
1099 (void) event_raise(addr->transport->event_action,
1100 US"tcp:close", NULL);
1101 #endif
1102 goto tls_retry_connection;
1103 }
1104 }
1105 else done = FALSE; /* Some timeout/connection problem */
1106 } /* Random check */
1107
1108 /* If the host is accepting all local parts, as determined by the "random"
1109 check, we don't need to waste time doing any further checking. */
1110
1111 if (new_domain_record.random_result != ccache_accept && done)
1112 {
1113 /* Get the rcpt_include_affixes flag from the transport if there is one,
1114 but assume FALSE if there is not. */
1115
1116 uschar * rcpt = transport_rcpt_address(addr,
1117 addr->transport ? addr->transport->rcpt_include_affixes : FALSE);
1118
1119 #ifdef SUPPORT_I18N
1120 /*XXX should the conversion be moved into transport_rcpt_address() ? */
1121 uschar * dummy_errstr = NULL;
1122 if ( testflag(addr, af_utf8_downcvt)
1123 && (rcpt = string_address_utf8_to_alabel(rcpt, &dummy_errstr),
1124 dummy_errstr
1125 ) )
1126 {
1127 errno = ERRNO_EXPANDFAIL;
1128 *failure_ptr = US"recipient";
1129 done = FALSE;
1130 }
1131 else
1132 #endif
1133
1134 done =
1135 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
1136 rcpt) >= 0 &&
1137 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1138 '2', callout);
1139
1140 if (done)
1141 new_address_record.result = ccache_accept;
1142 else if (errno == 0 && responsebuffer[0] == '5')
1143 {
1144 *failure_ptr = US"recipient";
1145 new_address_record.result = ccache_reject;
1146 }
1147
1148 /* Do postmaster check if requested; if a full check is required, we
1149 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
1150
1151 if (done && pm_mailfrom != NULL)
1152 {
1153 /* Could possibly shift before main verify, just above, and be ok
1154 for cutthrough. But no way to handle a subsequent rcpt, so just
1155 refuse any */
1156 cancel_cutthrough_connection("postmaster verify");
1157 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
1158
1159 done =
1160 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1161 smtp_read_response(&inblock, responsebuffer,
1162 sizeof(responsebuffer), '2', callout) &&
1163
1164 smtp_write_command(&outblock, FALSE,
1165 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
1166 smtp_read_response(&inblock, responsebuffer,
1167 sizeof(responsebuffer), '2', callout) &&
1168
1169 /* First try using the current domain */
1170
1171 ((
1172 smtp_write_command(&outblock, FALSE,
1173 "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 &&
1174 smtp_read_response(&inblock, responsebuffer,
1175 sizeof(responsebuffer), '2', callout)
1176 )
1177
1178 ||
1179
1180 /* If that doesn't work, and a full check is requested,
1181 try without the domain. */
1182
1183 (
1184 (options & vopt_callout_fullpm) != 0 &&
1185 smtp_write_command(&outblock, FALSE,
1186 "RCPT TO:<postmaster>\r\n") >= 0 &&
1187 smtp_read_response(&inblock, responsebuffer,
1188 sizeof(responsebuffer), '2', callout)
1189 ));
1190
1191 /* Sort out the cache record */
1192
1193 new_domain_record.postmaster_stamp = time(NULL);
1194
1195 if (done)
1196 new_domain_record.postmaster_result = ccache_accept;
1197 else if (errno == 0 && responsebuffer[0] == '5')
1198 {
1199 *failure_ptr = US"postmaster";
1200 setflag(addr, af_verify_pmfail);
1201 new_domain_record.postmaster_result = ccache_reject;
1202 }
1203 }
1204 } /* Random not accepted */
1205 } /* MAIL FROM: accepted */
1206
1207 /* For any failure of the main check, other than a negative response, we just
1208 close the connection and carry on. We can identify a negative response by the
1209 fact that errno is zero. For I/O errors it will be non-zero
1210
1211 Set up different error texts for logging and for sending back to the caller
1212 as an SMTP response. Log in all cases, using a one-line format. For sender
1213 callouts, give a full response to the caller, but for recipient callouts,
1214 don't give the IP address because this may be an internal host whose identity
1215 is not to be widely broadcast. */
1216
1217 if (!done)
1218 {
1219 if (errno == ETIMEDOUT)
1220 {
1221 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1222 send_quit = FALSE;
1223 }
1224 #ifdef SUPPORT_I18N
1225 else if (errno == ERRNO_UTF8_FWD)
1226 {
1227 extern int acl_where; /* src/acl.c */
1228 errno = 0;
1229 addr->message = string_sprintf(
1230 "response to \"%s\" from %s [%s] did not include SMTPUTF8",
1231 big_buffer, host->name, host->address);
1232 addr->user_message = acl_where == ACL_WHERE_RCPT
1233 ? US"533 mailbox name not allowed"
1234 : US"550 mailbox unavailable";
1235 yield = FAIL;
1236 done = TRUE;
1237 }
1238 #endif
1239 else if (errno == 0)
1240 {
1241 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1242
1243 addr->message =
1244 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1245 big_buffer, host->name, host->address,
1246 string_printing(responsebuffer));
1247
1248 addr->user_message = options & vopt_is_recipient
1249 ? string_sprintf("Callout verification failed:\n%s", responsebuffer)
1250 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1251 host->address, big_buffer, responsebuffer);
1252
1253 /* Hard rejection ends the process */
1254
1255 if (responsebuffer[0] == '5') /* Address rejected */
1256 {
1257 yield = FAIL;
1258 done = TRUE;
1259 }
1260 }
1261 }
1262
1263 /* End the SMTP conversation and close the connection. */
1264
1265 /* Cutthrough - on a successfull connect and recipient-verify with
1266 use-sender and we are 1st rcpt and have no cutthrough conn so far
1267 here is where we want to leave the conn open */
1268 if ( cutthrough.delivery
1269 && rcpt_count == 1
1270 && done
1271 && yield == OK
1272 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1273 == vopt_callout_recipsender
1274 && !random_local_part
1275 && !pm_mailfrom
1276 && cutthrough.fd < 0
1277 && !lmtp
1278 )
1279 {
1280 HDEBUG(D_acl|D_v) debug_printf("holding verify callout open for cutthrough delivery\n");
1281
1282 cutthrough.fd = outblock.sock; /* We assume no buffer in use in the outblock */
1283 cutthrough.nrcpt = 1;
1284 cutthrough.interface = interface;
1285 cutthrough.host = *host;
1286 cutthrough.addr = *addr; /* Save the address_item for later logging */
1287 cutthrough.addr.next = NULL;
1288 cutthrough.addr.host_used = &cutthrough.host;
1289 if (addr->parent)
1290 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1291 *addr->parent;
1292 ctblock.buffer = ctbuffer;
1293 ctblock.buffersize = sizeof(ctbuffer);
1294 ctblock.ptr = ctbuffer;
1295 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1296 ctblock.sock = cutthrough.fd;
1297 }
1298 else
1299 {
1300 /* Ensure no cutthrough on multiple address verifies */
1301 if (options & vopt_callout_recipsender)
1302 cancel_cutthrough_connection("multiple verify calls");
1303 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1304
1305 #ifdef SUPPORT_TLS
1306 tls_close(FALSE, TRUE);
1307 #endif
1308 (void)close(inblock.sock);
1309 #ifndef DISABLE_EVENT
1310 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1311 #endif
1312 }
1313
1314 } /* Loop through all hosts, while !done */
1315 }
1316
1317 /* If we get here with done == TRUE, a successful callout happened, and yield
1318 will be set OK or FAIL according to the response to the RCPT command.
1319 Otherwise, we looped through the hosts but couldn't complete the business.
1320 However, there may be domain-specific information to cache in both cases.
1321
1322 The value of the result field in the new_domain record is ccache_unknown if
1323 there was an error before or with MAIL FROM:, and errno was not zero,
1324 implying some kind of I/O error. We don't want to write the cache in that case.
1325 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1326
1327 if ( !(options & vopt_callout_no_cache)
1328 && new_domain_record.result != ccache_unknown)
1329 {
1330 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1331 == NULL)
1332 {
1333 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1334 }
1335 else
1336 {
1337 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1338 (int)sizeof(dbdata_callout_cache));
1339 HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
1340 " result=%d postmaster=%d random=%d\n",
1341 addr->domain,
1342 new_domain_record.result,
1343 new_domain_record.postmaster_result,
1344 new_domain_record.random_result);
1345 }
1346 }
1347
1348 /* If a definite result was obtained for the callout, cache it unless caching
1349 is disabled. */
1350
1351 if (done)
1352 {
1353 if ( !(options & vopt_callout_no_cache)
1354 && new_address_record.result != ccache_unknown)
1355 {
1356 if (dbm_file == NULL)
1357 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1358 if (dbm_file == NULL)
1359 {
1360 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1361 }
1362 else
1363 {
1364 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1365 (int)sizeof(dbdata_callout_cache_address));
1366 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
1367 new_address_record.result == ccache_accept ? "positive" : "negative",
1368 address_key);
1369 }
1370 }
1371 } /* done */
1372
1373 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1374 temporary error. If there was only one host, and a response was received, leave
1375 it alone if supplying details. Otherwise, give a generic response. */
1376
1377 else /* !done */
1378 {
1379 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1380 options & vopt_is_recipient ? "recipient" : "sender");
1381 yield = DEFER;
1382
1383 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1384
1385 addr->user_message = (!smtp_return_error_details)? dullmsg :
1386 string_sprintf("%s for <%s>.\n"
1387 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1388 "they may be permanently unreachable from this server. In the latter case,\n%s",
1389 dullmsg, addr->address,
1390 options & vopt_is_recipient
1391 ? "the address will never be accepted."
1392 : "you need to change the address or create an MX record for its domain\n"
1393 "if it is supposed to be generally accessible from the Internet.\n"
1394 "Talk to your mail administrator for details.");
1395
1396 /* Force a specific error code */
1397
1398 addr->basic_errno = ERRNO_CALLOUTDEFER;
1399 }
1400
1401 /* Come here from within the cache-reading code on fast-track exit. */
1402
1403 END_CALLOUT:
1404 if (dbm_file != NULL) dbfn_close(dbm_file);
1405 return yield;
1406 }
1407
1408
1409
1410 /* Called after recipient-acl to get a cutthrough connection open when
1411 one was requested and a recipient-verify wasn't subsequently done.
1412 */
1413 int
1414 open_cutthrough_connection( address_item * addr )
1415 {
1416 address_item addr2;
1417 int rc;
1418
1419 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1420 /* We must use a copy of the address for verification, because it might
1421 get rewritten. */
1422
1423 addr2 = *addr;
1424 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1425 rcpt_count > 1 ? "more" : "start");
1426 rc= verify_address(&addr2, NULL,
1427 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1428 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1429 NULL, NULL, NULL);
1430 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1431 return rc;
1432 }
1433
1434
1435
1436 /* Send given number of bytes from the buffer */
1437 static BOOL
1438 cutthrough_send(int n)
1439 {
1440 if(cutthrough.fd < 0)
1441 return TRUE;
1442
1443 if(
1444 #ifdef SUPPORT_TLS
1445 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1446 #endif
1447 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1448 )
1449 {
1450 transport_count += n;
1451 ctblock.ptr= ctblock.buffer;
1452 return TRUE;
1453 }
1454
1455 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1456 return FALSE;
1457 }
1458
1459
1460
1461 static BOOL
1462 _cutthrough_puts(uschar * cp, int n)
1463 {
1464 while(n--)
1465 {
1466 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1467 if(!cutthrough_send(ctblock.buffersize))
1468 return FALSE;
1469
1470 *ctblock.ptr++ = *cp++;
1471 }
1472 return TRUE;
1473 }
1474
1475 /* Buffered output of counted data block. Return boolean success */
1476 BOOL
1477 cutthrough_puts(uschar * cp, int n)
1478 {
1479 if (cutthrough.fd < 0) return TRUE;
1480 if (_cutthrough_puts(cp, n)) return TRUE;
1481 cancel_cutthrough_connection("transmit failed");
1482 return FALSE;
1483 }
1484
1485
1486 static BOOL
1487 _cutthrough_flush_send(void)
1488 {
1489 int n= ctblock.ptr-ctblock.buffer;
1490
1491 if(n>0)
1492 if(!cutthrough_send(n))
1493 return FALSE;
1494 return TRUE;
1495 }
1496
1497
1498 /* Send out any bufferred output. Return boolean success. */
1499 BOOL
1500 cutthrough_flush_send(void)
1501 {
1502 if (_cutthrough_flush_send()) return TRUE;
1503 cancel_cutthrough_connection("transmit failed");
1504 return FALSE;
1505 }
1506
1507
1508 BOOL
1509 cutthrough_put_nl(void)
1510 {
1511 return cutthrough_puts(US"\r\n", 2);
1512 }
1513
1514
1515 /* Get and check response from cutthrough target */
1516 static uschar
1517 cutthrough_response(char expect, uschar ** copy)
1518 {
1519 smtp_inblock inblock;
1520 uschar inbuffer[4096];
1521 uschar responsebuffer[4096];
1522
1523 inblock.buffer = inbuffer;
1524 inblock.buffersize = sizeof(inbuffer);
1525 inblock.ptr = inbuffer;
1526 inblock.ptrend = inbuffer;
1527 inblock.sock = cutthrough.fd;
1528 /* this relies on (inblock.sock == tls_out.active) */
1529 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1530 cancel_cutthrough_connection("target timeout on read");
1531
1532 if(copy != NULL)
1533 {
1534 uschar * cp;
1535 *copy = cp = string_copy(responsebuffer);
1536 /* Trim the trailing end of line */
1537 cp += Ustrlen(responsebuffer);
1538 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1539 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1540 }
1541
1542 return responsebuffer[0];
1543 }
1544
1545
1546 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1547 BOOL
1548 cutthrough_predata(void)
1549 {
1550 if(cutthrough.fd < 0)
1551 return FALSE;
1552
1553 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1554 cutthrough_puts(US"DATA\r\n", 6);
1555 cutthrough_flush_send();
1556
1557 /* Assume nothing buffered. If it was it gets ignored. */
1558 return cutthrough_response('3', NULL) == '3';
1559 }
1560
1561
1562 /* fd and tctx args only to match write_chunk() */
1563 static BOOL
1564 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1565 {
1566 uschar * s2;
1567 while(s && (s2 = Ustrchr(s, '\n')))
1568 {
1569 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1570 return FALSE;
1571 s = s2+1;
1572 }
1573 return TRUE;
1574 }
1575
1576
1577 /* Buffered send of headers. Return success boolean. */
1578 /* Expands newlines to wire format (CR,NL). */
1579 /* Also sends header-terminating blank line. */
1580 BOOL
1581 cutthrough_headers_send(void)
1582 {
1583 transport_ctx tctx;
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 tctx.tblock = cutthrough.addr.transport;
1594 tctx.addr = &cutthrough.addr;
1595 tctx.check_string = US".";
1596 tctx.escape_string = US"..";
1597 tctx.options = topt_use_crlf;
1598
1599 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1600 return FALSE;
1601
1602 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1603 return TRUE;
1604 }
1605
1606
1607 static void
1608 close_cutthrough_connection(const char * why)
1609 {
1610 if(cutthrough.fd >= 0)
1611 {
1612 /* We could be sending this after a bunch of data, but that is ok as
1613 the only way to cancel the transfer in dataphase is to drop the tcp
1614 conn before the final dot.
1615 */
1616 ctblock.ptr = ctbuffer;
1617 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1618 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1619 _cutthrough_flush_send();
1620 /* No wait for response */
1621
1622 #ifdef SUPPORT_TLS
1623 tls_close(FALSE, TRUE);
1624 #endif
1625 (void)close(cutthrough.fd);
1626 cutthrough.fd = -1;
1627 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1628 }
1629 ctblock.ptr = ctbuffer;
1630 }
1631
1632 void
1633 cancel_cutthrough_connection(const char * why)
1634 {
1635 close_cutthrough_connection(why);
1636 cutthrough.delivery = FALSE;
1637 }
1638
1639
1640
1641
1642 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1643 Log an OK response as a transmission.
1644 Close the connection.
1645 Return smtp response-class digit.
1646 */
1647 uschar *
1648 cutthrough_finaldot(void)
1649 {
1650 uschar res;
1651 address_item * addr;
1652 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1653
1654 /* Assume data finshed with new-line */
1655 if( !cutthrough_puts(US".", 1)
1656 || !cutthrough_put_nl()
1657 || !cutthrough_flush_send()
1658 )
1659 return cutthrough.addr.message;
1660
1661 res = cutthrough_response('2', &cutthrough.addr.message);
1662 for (addr = &cutthrough.addr; addr; addr = addr->next)
1663 {
1664 addr->message = cutthrough.addr.message;
1665 switch(res)
1666 {
1667 case '2':
1668 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1669 close_cutthrough_connection("delivered");
1670 break;
1671
1672 case '4':
1673 delivery_log(LOG_MAIN, addr, 0,
1674 US"tmp-reject from cutthrough after DATA:");
1675 break;
1676
1677 case '5':
1678 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1679 US"rejected after DATA:");
1680 break;
1681
1682 default:
1683 break;
1684 }
1685 }
1686 return cutthrough.addr.message;
1687 }
1688
1689
1690
1691 /*************************************************
1692 * Copy error to toplevel address *
1693 *************************************************/
1694
1695 /* This function is used when a verify fails or defers, to ensure that the
1696 failure or defer information is in the original toplevel address. This applies
1697 when an address is redirected to a single new address, and the failure or
1698 deferral happens to the child address.
1699
1700 Arguments:
1701 vaddr the verify address item
1702 addr the final address item
1703 yield FAIL or DEFER
1704
1705 Returns: the value of YIELD
1706 */
1707
1708 static int
1709 copy_error(address_item *vaddr, address_item *addr, int yield)
1710 {
1711 if (addr != vaddr)
1712 {
1713 vaddr->message = addr->message;
1714 vaddr->user_message = addr->user_message;
1715 vaddr->basic_errno = addr->basic_errno;
1716 vaddr->more_errno = addr->more_errno;
1717 vaddr->prop.address_data = addr->prop.address_data;
1718 copyflag(vaddr, addr, af_pass_message);
1719 }
1720 return yield;
1721 }
1722
1723
1724
1725
1726 /**************************************************
1727 * printf that automatically handles TLS if needed *
1728 ***************************************************/
1729
1730 /* This function is used by verify_address() as a substitute for all fprintf()
1731 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1732 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1733 that assumes that we always use the smtp_out FILE* when not using TLS or the
1734 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1735 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1736 fprintf().
1737
1738 Arguments:
1739 f the candidate FILE* to write to
1740 format format string
1741 ... optional arguments
1742
1743 Returns:
1744 nothing
1745 */
1746
1747 static void PRINTF_FUNCTION(2,3)
1748 respond_printf(FILE *f, const char *format, ...)
1749 {
1750 va_list ap;
1751
1752 va_start(ap, format);
1753 if (smtp_out && (f == smtp_out))
1754 smtp_vprintf(format, ap);
1755 else
1756 vfprintf(f, format, ap);
1757 va_end(ap);
1758 }
1759
1760
1761
1762 /*************************************************
1763 * Verify an email address *
1764 *************************************************/
1765
1766 /* This function is used both for verification (-bv and at other times) and
1767 address testing (-bt), which is indicated by address_test_mode being set.
1768
1769 Arguments:
1770 vaddr contains the address to verify; the next field in this block
1771 must be NULL
1772 f if not NULL, write the result to this file
1773 options various option bits:
1774 vopt_fake_sender => this sender verify is not for the real
1775 sender (it was verify=sender=xxxx or an address from a
1776 header line) - rewriting must not change sender_address
1777 vopt_is_recipient => this is a recipient address, otherwise
1778 it's a sender address - this affects qualification and
1779 rewriting and messages from callouts
1780 vopt_qualify => qualify an unqualified address; else error
1781 vopt_expn => called from SMTP EXPN command
1782 vopt_success_on_redirect => when a new address is generated
1783 the verification instantly succeeds
1784
1785 These ones are used by do_callout() -- the options variable
1786 is passed to it.
1787
1788 vopt_callout_fullpm => if postmaster check, do full one
1789 vopt_callout_no_cache => don't use callout cache
1790 vopt_callout_random => do the "random" thing
1791 vopt_callout_recipsender => use real sender for recipient
1792 vopt_callout_recippmaster => use postmaster for recipient
1793
1794 callout if > 0, specifies that callout is required, and gives timeout
1795 for individual commands
1796 callout_overall if > 0, gives overall timeout for the callout function;
1797 if < 0, a default is used (see do_callout())
1798 callout_connect the connection timeout for callouts
1799 se_mailfrom when callout is requested to verify a sender, use this
1800 in MAIL FROM; NULL => ""
1801 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1802 thing and use this as the sender address (may be "")
1803
1804 routed if not NULL, set TRUE if routing succeeded, so we can
1805 distinguish between routing failed and callout failed
1806
1807 Returns: OK address verified
1808 FAIL address failed to verify
1809 DEFER can't tell at present
1810 */
1811
1812 int
1813 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1814 int callout_overall, int callout_connect, uschar *se_mailfrom,
1815 uschar *pm_mailfrom, BOOL *routed)
1816 {
1817 BOOL allok = TRUE;
1818 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 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 options & vopt_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 = options & vopt_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, options & vopt_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, options & vopt_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 (so no returns allowed from here on). */
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 /* Observability variable for router/transport use */
1914
1915 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1916
1917 /* Update the address structure with the possibly qualified and rewritten
1918 address. Set it up as the starting address on the chain of new addresses. */
1919
1920 vaddr->address = address;
1921 addr_new = vaddr;
1922
1923 /* We need a loop, because an address can generate new addresses. We must also
1924 cope with generated pipes and files at the top level. (See also the code and
1925 comment in deliver.c.) However, it is usually the case that the router for
1926 user's .forward files has its verify flag turned off.
1927
1928 If an address generates more than one child, the loop is used only when
1929 full_info is set, and this can only be set locally. Remote enquiries just get
1930 information about the top level address, not anything that it generated. */
1931
1932 while (addr_new)
1933 {
1934 int rc;
1935 address_item *addr = addr_new;
1936
1937 addr_new = addr->next;
1938 addr->next = NULL;
1939
1940 DEBUG(D_verify)
1941 {
1942 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1943 debug_printf("Considering %s\n", addr->address);
1944 }
1945
1946 /* Handle generated pipe, file or reply addresses. We don't get these
1947 when handling EXPN, as it does only one level of expansion. */
1948
1949 if (testflag(addr, af_pfr))
1950 {
1951 allok = FALSE;
1952 if (f != NULL)
1953 {
1954 BOOL allow;
1955
1956 if (addr->address[0] == '>')
1957 {
1958 allow = testflag(addr, af_allow_reply);
1959 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1960 }
1961 else
1962 {
1963 allow = (addr->address[0] == '|')?
1964 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1965 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1966 }
1967
1968 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1969 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1970 "%s\n", addr->message);
1971 else if (allow)
1972 fprintf(f, "\n transport = %s\n", addr->transport->name);
1973 else
1974 fprintf(f, " *** forbidden ***\n");
1975 }
1976 continue;
1977 }
1978
1979 /* Just in case some router parameter refers to it. */
1980
1981 return_path = addr->prop.errors_address
1982 ? addr->prop.errors_address : sender_address;
1983
1984 /* Split the address into domain and local part, handling the %-hack if
1985 necessary, and then route it. While routing a sender address, set
1986 $sender_address to <> because that is what it will be if we were trying to
1987 send a bounce to the sender. */
1988
1989 if (routed) *routed = FALSE;
1990 if ((rc = deliver_split_address(addr)) == OK)
1991 {
1992 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1993 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1994 &addr_succeed, verify_type);
1995 sender_address = save_sender; /* Put back the real sender */
1996 }
1997
1998 /* If routing an address succeeded, set the flag that remembers, for use when
1999 an ACL cached a sender verify (in case a callout fails). Then if routing set
2000 up a list of hosts or the transport has a host list, and the callout option
2001 is set, and we aren't in a host checking run, do the callout verification,
2002 and set another flag that notes that a callout happened. */
2003
2004 if (rc == OK)
2005 {
2006 if (routed) *routed = TRUE;
2007 if (callout > 0)
2008 {
2009 transport_instance * tp;
2010 host_item * host_list = addr->host_list;
2011
2012 /* Make up some data for use in the case where there is no remote
2013 transport. */
2014
2015 transport_feedback tf = {
2016 NULL, /* interface (=> any) */
2017 US"smtp", /* port */
2018 US"smtp", /* protocol */
2019 NULL, /* hosts */
2020 US"$smtp_active_hostname", /* helo_data */
2021 FALSE, /* hosts_override */
2022 FALSE, /* hosts_randomize */
2023 FALSE, /* gethostbyname */
2024 TRUE, /* qualify_single */
2025 FALSE /* search_parents */
2026 };
2027
2028 /* If verification yielded a remote transport, we want to use that
2029 transport's options, so as to mimic what would happen if we were really
2030 sending a message to this address. */
2031
2032 if ((tp = addr->transport) && !tp->info->local)
2033 {
2034 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
2035
2036 /* If the transport has hosts and the router does not, or if the
2037 transport is configured to override the router's hosts, we must build a
2038 host list of the transport's hosts, and find the IP addresses */
2039
2040 if (tf.hosts && (!host_list || tf.hosts_override))
2041 {
2042 uschar *s;
2043 const uschar *save_deliver_domain = deliver_domain;
2044 uschar *save_deliver_localpart = deliver_localpart;
2045
2046 host_list = NULL; /* Ignore the router's hosts */
2047
2048 deliver_domain = addr->domain;
2049 deliver_localpart = addr->local_part;
2050 s = expand_string(tf.hosts);
2051 deliver_domain = save_deliver_domain;
2052 deliver_localpart = save_deliver_localpart;
2053
2054 if (!s)
2055 {
2056 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
2057 "\"%s\" in %s transport for callout: %s", tf.hosts,
2058 tp->name, expand_string_message);
2059 }
2060 else
2061 {
2062 int flags;
2063 host_item *host, *nexthost;
2064 host_build_hostlist(&host_list, s, tf.hosts_randomize);
2065
2066 /* Just ignore failures to find a host address. If we don't manage
2067 to find any addresses, the callout will defer. Note that more than
2068 one address may be found for a single host, which will result in
2069 additional host items being inserted into the chain. Hence we must
2070 save the next host first. */
2071
2072 flags = HOST_FIND_BY_A;
2073 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2074 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2075
2076 for (host = host_list; host; host = nexthost)
2077 {
2078 nexthost = host->next;
2079 if (tf.gethostbyname ||
2080 string_is_ip_address(host->name, NULL) != 0)
2081 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
2082 else
2083 {
2084 dnssec_domains * dnssec_domains = NULL;
2085 if (Ustrcmp(tp->driver_name, "smtp") == 0)
2086 {
2087 smtp_transport_options_block * ob =
2088 (smtp_transport_options_block *) tp->options_block;
2089 dnssec_domains = &ob->dnssec;
2090 }
2091
2092 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2093 dnssec_domains, NULL, NULL);
2094 }
2095 }
2096 }
2097 }
2098 }
2099
2100 /* Can only do a callout if we have at least one host! If the callout
2101 fails, it will have set ${sender,recipient}_verify_failure. */
2102
2103 if (host_list)
2104 {
2105 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
2106 if (host_checking && !host_checking_callout)
2107 {
2108 HDEBUG(D_verify)
2109 debug_printf("... callout omitted by default when host testing\n"
2110 "(Use -bhc if you want the callouts to happen.)\n");
2111 }
2112 else
2113 {
2114 #ifdef SUPPORT_TLS
2115 deliver_set_expansions(addr);
2116 #endif
2117 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
2118 callout_connect, options, se_mailfrom, pm_mailfrom);
2119 }
2120 }
2121 else
2122 {
2123 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
2124 "transport provided a host list\n");
2125 }
2126 }
2127 }
2128
2129 /* Otherwise, any failure is a routing failure */
2130
2131 else *failure_ptr = US"route";
2132
2133 /* A router may return REROUTED if it has set up a child address as a result
2134 of a change of domain name (typically from widening). In this case we always
2135 want to continue to verify the new child. */
2136
2137 if (rc == REROUTED) continue;
2138
2139 /* Handle hard failures */
2140
2141 if (rc == FAIL)
2142 {
2143 allok = FALSE;
2144 if (f)
2145 {
2146 address_item *p = addr->parent;
2147
2148 respond_printf(f, "%s%s %s", ko_prefix,
2149 full_info ? addr->address : address,
2150 address_test_mode ? "is undeliverable" : "failed to verify");
2151 if (!expn && admin_user)
2152 {
2153 if (addr->basic_errno > 0)
2154 respond_printf(f, ": %s", strerror(addr->basic_errno));
2155 if (addr->message)
2156 respond_printf(f, ": %s", addr->message);
2157 }
2158
2159 /* Show parents iff doing full info */
2160
2161 if (full_info) while (p)
2162 {
2163 respond_printf(f, "%s\n <-- %s", cr, p->address);
2164 p = p->parent;
2165 }
2166 respond_printf(f, "%s\n", cr);
2167 }
2168 cancel_cutthrough_connection("routing hard fail");
2169
2170 if (!full_info)
2171 {
2172 yield = copy_error(vaddr, addr, FAIL);
2173 goto out;
2174 }
2175 yield = FAIL;
2176 }
2177
2178 /* Soft failure */
2179
2180 else if (rc == DEFER)
2181 {
2182 allok = FALSE;
2183 if (f)
2184 {
2185 address_item *p = addr->parent;
2186 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
2187 full_info? addr->address : address);
2188 if (!expn && admin_user)
2189 {
2190 if (addr->basic_errno > 0)
2191 respond_printf(f, ": %s", strerror(addr->basic_errno));
2192 if (addr->message)
2193 respond_printf(f, ": %s", addr->message);
2194 else if (addr->basic_errno <= 0)
2195 respond_printf(f, ": unknown error");
2196 }
2197
2198 /* Show parents iff doing full info */
2199
2200 if (full_info) while (p)
2201 {
2202 respond_printf(f, "%s\n <-- %s", cr, p->address);
2203 p = p->parent;
2204 }
2205 respond_printf(f, "%s\n", cr);
2206 }
2207 cancel_cutthrough_connection("routing soft fail");
2208
2209 if (!full_info)
2210 {
2211 yield = copy_error(vaddr, addr, DEFER);
2212 goto out;
2213 }
2214 if (yield == OK) yield = DEFER;
2215 }
2216
2217 /* If we are handling EXPN, we do not want to continue to route beyond
2218 the top level (whose address is in "address"). */
2219
2220 else if (expn)
2221 {
2222 uschar *ok_prefix = US"250-";
2223
2224 if (!addr_new)
2225 if (!addr_local && !addr_remote)
2226 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2227 else
2228 respond_printf(f, "250 <%s>\r\n", address);
2229
2230 else do
2231 {
2232 address_item *addr2 = addr_new;
2233 addr_new = addr2->next;
2234 if (!addr_new) ok_prefix = US"250 ";
2235 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2236 } while (addr_new);
2237 yield = OK;
2238 goto out;
2239 }
2240
2241 /* Successful routing other than EXPN. */
2242
2243 else
2244 {
2245 /* Handle successful routing when short info wanted. Otherwise continue for
2246 other (generated) addresses. Short info is the operational case. Full info
2247 can be requested only when debug_selector != 0 and a file is supplied.
2248
2249 There is a conflict between the use of aliasing as an alternate email
2250 address, and as a sort of mailing list. If an alias turns the incoming
2251 address into just one address (e.g. J.Caesar->jc44) you may well want to
2252 carry on verifying the generated address to ensure it is valid when
2253 checking incoming mail. If aliasing generates multiple addresses, you
2254 probably don't want to do this. Exim therefore treats the generation of
2255 just a single new address as a special case, and continues on to verify the
2256 generated address. */
2257
2258 if ( !full_info /* Stop if short info wanted AND */
2259 && ( ( !addr_new /* No new address OR */
2260 || addr_new->next /* More than one new address OR */
2261 || testflag(addr_new, af_pfr) /* New address is pfr */
2262 )
2263 || /* OR */
2264 ( addr_new /* At least one new address AND */
2265 && success_on_redirect /* success_on_redirect is set */
2266 ) )
2267 )
2268 {
2269 if (f) fprintf(f, "%s %s\n",
2270 address, address_test_mode ? "is deliverable" : "verified");
2271
2272 /* If we have carried on to verify a child address, we want the value
2273 of $address_data to be that of the child */
2274
2275 vaddr->prop.address_data = addr->prop.address_data;
2276
2277 /* If stopped because more than one new address, cannot cutthrough */
2278
2279 if (addr_new && addr_new->next)
2280 cancel_cutthrough_connection("multiple addresses from routing");
2281
2282 yield = OK;
2283 goto out;
2284 }
2285 }
2286 } /* Loop for generated addresses */
2287
2288 /* Display the full results of the successful routing, including any generated
2289 addresses. Control gets here only when full_info is set, which requires f not
2290 to be NULL, and this occurs only when a top-level verify is called with the
2291 debugging switch on.
2292
2293 If there are no local and no remote addresses, and there were no pipes, files,
2294 or autoreplies, and there were no errors or deferments, the message is to be
2295 discarded, usually because of the use of :blackhole: in an alias file. */
2296
2297 if (allok && !addr_local && !addr_remote)
2298 {
2299 fprintf(f, "mail to %s is discarded\n", address);
2300 goto out;
2301 }
2302
2303 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2304 while (addr_list)
2305 {
2306 address_item *addr = addr_list;
2307 address_item *p = addr->parent;
2308 transport_instance * tp = addr->transport;
2309
2310 addr_list = addr->next;
2311
2312 fprintf(f, "%s", CS addr->address);
2313 #ifdef EXPERIMENTAL_SRS
2314 if(addr->prop.srs_sender)
2315 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2316 #endif
2317
2318 /* If the address is a duplicate, show something about it. */
2319
2320 if (!testflag(addr, af_pfr))
2321 {
2322 tree_node *tnode;
2323 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2324 fprintf(f, " [duplicate, would not be delivered]");
2325 else tree_add_duplicate(addr->unique, addr);
2326 }
2327
2328 /* Now show its parents */
2329
2330 for (p = addr->parent; p; p = p->parent)
2331 fprintf(f, "\n <-- %s", p->address);
2332 fprintf(f, "\n ");
2333
2334 /* Show router, and transport */
2335
2336 fprintf(f, "router = %s, transport = %s\n",
2337 addr->router->name, tp ? tp->name : US"unset");
2338
2339 /* Show any hosts that are set up by a router unless the transport
2340 is going to override them; fiddle a bit to get a nice format. */
2341
2342 if (addr->host_list && tp && !tp->overrides_hosts)
2343 {
2344 host_item *h;
2345 int maxlen = 0;
2346 int maxaddlen = 0;
2347 for (h = addr->host_list; h; h = h->next)
2348 { /* get max lengths of host names, addrs */
2349 int len = Ustrlen(h->name);
2350 if (len > maxlen) maxlen = len;
2351 len = h->address ? Ustrlen(h->address) : 7;
2352 if (len > maxaddlen) maxaddlen = len;
2353 }
2354 for (h = addr->host_list; h; h = h->next)
2355 {
2356 fprintf(f, " host %-*s ", maxlen, h->name);
2357
2358 if (h->address)
2359 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2360 else if (tp->info->local)
2361 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2362 else
2363 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2364
2365 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2366 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2367 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2368 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2369 fputc('\n', f);
2370 }
2371 }
2372 }
2373
2374 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2375 the -bv or -bt case). */
2376
2377 out:
2378 verify_mode = NULL;
2379 tls_modify_variables(&tls_in);
2380
2381 return yield;
2382 }
2383
2384
2385
2386
2387 /*************************************************
2388 * Check headers for syntax errors *
2389 *************************************************/
2390
2391 /* This function checks those header lines that contain addresses, and verifies
2392 that all the addresses therein are syntactially correct.
2393
2394 Arguments:
2395 msgptr where to put an error message
2396
2397 Returns: OK
2398 FAIL
2399 */
2400
2401 int
2402 verify_check_headers(uschar **msgptr)
2403 {
2404 header_line *h;
2405 uschar *colon, *s;
2406 int yield = OK;
2407
2408 for (h = header_list; h != NULL && yield == OK; h = h->next)
2409 {
2410 if (h->type != htype_from &&
2411 h->type != htype_reply_to &&
2412 h->type != htype_sender &&
2413 h->type != htype_to &&
2414 h->type != htype_cc &&
2415 h->type != htype_bcc)
2416 continue;
2417
2418 colon = Ustrchr(h->text, ':');
2419 s = colon + 1;
2420 while (isspace(*s)) s++;
2421
2422 /* Loop for multiple addresses in the header, enabling group syntax. Note
2423 that we have to reset this after the header has been scanned. */
2424
2425 parse_allow_group = TRUE;
2426
2427 while (*s != 0)
2428 {
2429 uschar *ss = parse_find_address_end(s, FALSE);
2430 uschar *recipient, *errmess;
2431 int terminator = *ss;
2432 int start, end, domain;
2433
2434 /* Temporarily terminate the string at this point, and extract the
2435 operative address within, allowing group syntax. */
2436
2437 *ss = 0;
2438 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2439 *ss = terminator;
2440
2441 /* Permit an unqualified address only if the message is local, or if the
2442 sending host is configured to be permitted to send them. */
2443
2444 if (recipient != NULL && domain == 0)
2445 {
2446 if (h->type == htype_from || h->type == htype_sender)
2447 {
2448 if (!allow_unqualified_sender) recipient = NULL;
2449 }
2450 else
2451 {
2452 if (!allow_unqualified_recipient) recipient = NULL;
2453 }
2454 if (recipient == NULL) errmess = US"unqualified address not permitted";
2455 }
2456
2457 /* It's an error if no address could be extracted, except for the special
2458 case of an empty address. */
2459
2460 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2461 {
2462 uschar *verb = US"is";
2463 uschar *t = ss;
2464 uschar *tt = colon;
2465 int len;
2466
2467 /* Arrange not to include any white space at the end in the
2468 error message or the header name. */
2469
2470 while (t > s && isspace(t[-1])) t--;
2471 while (tt > h->text && isspace(tt[-1])) tt--;
2472
2473 /* Add the address that failed to the error message, since in a
2474 header with very many addresses it is sometimes hard to spot
2475 which one is at fault. However, limit the amount of address to
2476 quote - cases have been seen where, for example, a missing double
2477 quote in a humungous To: header creates an "address" that is longer
2478 than string_sprintf can handle. */
2479
2480 len = t - s;
2481 if (len > 1024)
2482 {
2483 len = 1024;
2484 verb = US"begins";
2485 }
2486
2487 /* deconst cast ok as we're passing a non-const to string_printing() */
2488 *msgptr = US string_printing(
2489 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2490 errmess, tt - h->text, h->text, verb, len, s));
2491
2492 yield = FAIL;
2493 break; /* Out of address loop */
2494 }
2495
2496 /* Advance to the next address */
2497
2498 s = ss + (terminator? 1:0);
2499 while (isspace(*s)) s++;
2500 } /* Next address */
2501
2502 parse_allow_group = FALSE;
2503 parse_found_group = FALSE;
2504 } /* Next header unless yield has been set FALSE */
2505
2506 return yield;
2507 }
2508
2509
2510 /*************************************************
2511 * Check header names for 8-bit characters *
2512 *************************************************/
2513
2514 /* This function checks for invalid charcters in header names. See
2515 RFC 5322, 2.2. and RFC 6532, 3.
2516
2517 Arguments:
2518 msgptr where to put an error message
2519
2520 Returns: OK
2521 FAIL
2522 */
2523
2524 int
2525 verify_check_header_names_ascii(uschar **msgptr)
2526 {
2527 header_line *h;
2528 uschar *colon, *s;
2529
2530 for (h = header_list; h != NULL; h = h->next)
2531 {
2532 colon = Ustrchr(h->text, ':');
2533 for(s = h->text; s < colon; s++)
2534 {
2535 if ((*s < 33) || (*s > 126))
2536 {
2537 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2538 colon - h->text, h->text);
2539 return FAIL;
2540 }
2541 }
2542 }
2543 return OK;
2544 }
2545
2546 /*************************************************
2547 * Check for blind recipients *
2548 *************************************************/
2549
2550 /* This function checks that every (envelope) recipient is mentioned in either
2551 the To: or Cc: header lines, thus detecting blind carbon copies.
2552
2553 There are two ways of scanning that could be used: either scan the header lines
2554 and tick off the recipients, or scan the recipients and check the header lines.
2555 The original proposed patch did the former, but I have chosen to do the latter,
2556 because (a) it requires no memory and (b) will use fewer resources when there
2557 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2558
2559 Arguments: none
2560 Returns: OK if there are no blind recipients
2561 FAIL if there is at least one blind recipient
2562 */
2563
2564 int
2565 verify_check_notblind(void)
2566 {
2567 int i;
2568 for (i = 0; i < recipients_count; i++)
2569 {
2570 header_line *h;
2571 BOOL found = FALSE;
2572 uschar *address = recipients_list[i].address;
2573
2574 for (h = header_list; !found && h != NULL; h = h->next)
2575 {
2576 uschar *colon, *s;
2577
2578 if (h->type != htype_to && h->type != htype_cc) continue;
2579
2580 colon = Ustrchr(h->text, ':');
2581 s = colon + 1;
2582 while (isspace(*s)) s++;
2583
2584 /* Loop for multiple addresses in the header, enabling group syntax. Note
2585 that we have to reset this after the header has been scanned. */
2586
2587 parse_allow_group = TRUE;
2588
2589 while (*s != 0)
2590 {
2591 uschar *ss = parse_find_address_end(s, FALSE);
2592 uschar *recipient,*errmess;
2593 int terminator = *ss;
2594 int start, end, domain;
2595
2596 /* Temporarily terminate the string at this point, and extract the
2597 operative address within, allowing group syntax. */
2598
2599 *ss = 0;
2600 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2601 *ss = terminator;
2602
2603 /* If we found a valid recipient that has a domain, compare it with the
2604 envelope recipient. Local parts are compared case-sensitively, domains
2605 case-insensitively. By comparing from the start with length "domain", we
2606 include the "@" at the end, which ensures that we are comparing the whole
2607 local part of each address. */
2608
2609 if (recipient != NULL && domain != 0)
2610 {
2611 found = Ustrncmp(recipient, address, domain) == 0 &&
2612 strcmpic(recipient + domain, address + domain) == 0;
2613 if (found) break;
2614 }
2615
2616 /* Advance to the next address */
2617
2618 s = ss + (terminator? 1:0);
2619 while (isspace(*s)) s++;
2620 } /* Next address */
2621
2622 parse_allow_group = FALSE;
2623 parse_found_group = FALSE;
2624 } /* Next header (if found is false) */
2625
2626 if (!found) return FAIL;
2627 } /* Next recipient */
2628
2629 return OK;
2630 }
2631
2632
2633
2634 /*************************************************
2635 * Find if verified sender *
2636 *************************************************/
2637
2638 /* Usually, just a single address is verified as the sender of the message.
2639 However, Exim can be made to verify other addresses as well (often related in
2640 some way), and this is useful in some environments. There may therefore be a
2641 chain of such addresses that have previously been tested. This function finds
2642 whether a given address is on the chain.
2643
2644 Arguments: the address to be verified
2645 Returns: pointer to an address item, or NULL
2646 */
2647
2648 address_item *
2649 verify_checked_sender(uschar *sender)
2650 {
2651 address_item *addr;
2652 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2653 if (Ustrcmp(sender, addr->address) == 0) break;
2654 return addr;
2655 }
2656
2657
2658
2659
2660
2661 /*************************************************
2662 * Get valid header address *
2663 *************************************************/
2664
2665 /* Scan the originator headers of the message, looking for an address that
2666 verifies successfully. RFC 822 says:
2667
2668 o The "Sender" field mailbox should be sent notices of
2669 any problems in transport or delivery of the original
2670 messages. If there is no "Sender" field, then the
2671 "From" field mailbox should be used.
2672
2673 o If the "Reply-To" field exists, then the reply should
2674 go to the addresses indicated in that field and not to
2675 the address(es) indicated in the "From" field.
2676
2677 So we check a Sender field if there is one, else a Reply_to field, else a From
2678 field. As some strange messages may have more than one of these fields,
2679 especially if they are resent- fields, check all of them if there is more than
2680 one.
2681
2682 Arguments:
2683 user_msgptr points to where to put a user error message
2684 log_msgptr points to where to put a log error message
2685 callout timeout for callout check (passed to verify_address())
2686 callout_overall overall callout timeout (ditto)
2687 callout_connect connect callout timeout (ditto)
2688 se_mailfrom mailfrom for verify; NULL => ""
2689 pm_mailfrom sender for pm callout check (passed to verify_address())
2690 options callout options (passed to verify_address())
2691 verrno where to put the address basic_errno
2692
2693 If log_msgptr is set to something without setting user_msgptr, the caller
2694 normally uses log_msgptr for both things.
2695
2696 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2697 FAIL is given if no appropriate headers are found
2698 */
2699
2700 int
2701 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2702 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2703 uschar *pm_mailfrom, int options, int *verrno)
2704 {
2705 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2706 BOOL done = FALSE;
2707 int yield = FAIL;
2708 int i;
2709
2710 for (i = 0; i < 3 && !done; i++)
2711 {
2712 header_line *h;
2713 for (h = header_list; h != NULL && !done; h = h->next)
2714 {
2715 int terminator, new_ok;
2716 uschar *s, *ss, *endname;
2717
2718 if (h->type != header_types[i]) continue;
2719 s = endname = Ustrchr(h->text, ':') + 1;
2720
2721 /* Scan the addresses in the header, enabling group syntax. Note that we
2722 have to reset this after the header has been scanned. */
2723
2724 parse_allow_group = TRUE;
2725
2726 while (*s != 0)
2727 {
2728 address_item *vaddr;
2729
2730 while (isspace(*s) || *s == ',') s++;
2731 if (*s == 0) break; /* End of header */
2732
2733 ss = parse_find_address_end(s, FALSE);
2734
2735 /* The terminator is a comma or end of header, but there may be white
2736 space preceding it (including newline for the last address). Move back
2737 past any white space so we can check against any cached envelope sender
2738 address verifications. */
2739
2740 while (isspace(ss[-1])) ss--;
2741 terminator = *ss;
2742 *ss = 0;
2743
2744 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2745 (int)(endname - h->text), h->text, s);
2746
2747 /* See if we have already verified this address as an envelope sender,
2748 and if so, use the previous answer. */
2749
2750 vaddr = verify_checked_sender(s);
2751
2752 if (vaddr != NULL && /* Previously checked */
2753 (callout <= 0 || /* No callout needed; OR */
2754 vaddr->special_action > 256)) /* Callout was done */
2755 {
2756 new_ok = vaddr->special_action & 255;
2757 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2758 *ss = terminator; /* Restore shortened string */
2759 }
2760
2761 /* Otherwise we run the verification now. We must restore the shortened
2762 string before running the verification, so the headers are correct, in
2763 case there is any rewriting. */
2764
2765 else
2766 {
2767 int start, end, domain;
2768 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2769 &domain, FALSE);
2770
2771 *ss = terminator;
2772
2773 /* If we found an empty address, just carry on with the next one, but
2774 kill the message. */
2775
2776 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2777 {
2778 *log_msgptr = NULL;
2779 s = ss;
2780 continue;
2781 }
2782
2783 /* If verification failed because of a syntax error, fail this
2784 function, and ensure that the failing address gets added to the error
2785 message. */
2786
2787 if (address == NULL)
2788 {
2789 new_ok = FAIL;
2790 while (ss > s && isspace(ss[-1])) ss--;
2791 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2792 "scanning for sender: %s in \"%.*s\"",
2793 endname - h->text, h->text, *log_msgptr, ss - s, s);
2794 yield = FAIL;
2795 done = TRUE;
2796 break;
2797 }
2798
2799 /* Else go ahead with the sender verification. But it isn't *the*
2800 sender of the message, so set vopt_fake_sender to stop sender_address
2801 being replaced after rewriting or qualification. */
2802
2803 else
2804 {
2805 vaddr = deliver_make_addr(address, FALSE);
2806 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2807 callout, callout_overall, callout_connect, se_mailfrom,
2808 pm_mailfrom, NULL);
2809 }
2810 }
2811
2812 /* We now have the result, either newly found, or cached. If we are
2813 giving out error details, set a specific user error. This means that the
2814 last of these will be returned to the user if all three fail. We do not
2815 set a log message - the generic one below will be used. */
2816
2817 if (new_ok != OK)
2818 {
2819 *verrno = vaddr->basic_errno;
2820 if (smtp_return_error_details)
2821 {
2822 *user_msgptr = string_sprintf("Rejected after DATA: "
2823 "could not verify \"%.*s\" header address\n%s: %s",
2824 endname - h->text, h->text, vaddr->address, vaddr->message);
2825 }
2826 }
2827
2828 /* Success or defer */
2829
2830 if (new_ok == OK)
2831 {
2832 yield = OK;
2833 done = TRUE;
2834 break;
2835 }
2836
2837 if (new_ok == DEFER) yield = DEFER;
2838
2839 /* Move on to any more addresses in the header */
2840
2841 s = ss;
2842 } /* Next address */
2843
2844 parse_allow_group = FALSE;
2845 parse_found_group = FALSE;
2846 } /* Next header, unless done */
2847 } /* Next header type unless done */
2848
2849 if (yield == FAIL && *log_msgptr == NULL)
2850 *log_msgptr = US"there is no valid sender in any header line";
2851
2852 if (yield == DEFER && *log_msgptr == NULL)
2853 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2854
2855 return yield;
2856 }
2857
2858
2859
2860
2861 /*************************************************
2862 * Get RFC 1413 identification *
2863 *************************************************/
2864
2865 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2866 the timeout is set to zero, then the query is not done. There may also be lists
2867 of hosts and nets which are exempt. To guard against malefactors sending
2868 non-printing characters which could, for example, disrupt a message's headers,
2869 make sure the string consists of printing characters only.
2870
2871 Argument:
2872 port the port to connect to; usually this is IDENT_PORT (113), but when
2873 running in the test harness with -bh a different value is used.
2874
2875 Returns: nothing
2876
2877 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2878 */
2879
2880 void
2881 verify_get_ident(int port)
2882 {
2883 int sock, host_af, qlen;
2884 int received_sender_port, received_interface_port, n;
2885 uschar *p;
2886 uschar buffer[2048];
2887
2888 /* Default is no ident. Check whether we want to do an ident check for this
2889 host. */
2890
2891 sender_ident = NULL;
2892 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2893 return;
2894
2895 DEBUG(D_ident) debug_printf("doing ident callback\n");
2896
2897 /* Set up a connection to the ident port of the remote host. Bind the local end
2898 to the incoming interface address. If the sender host address is an IPv6
2899 address, the incoming interface address will also be IPv6. */
2900
2901 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2902 sock = ip_socket(SOCK_STREAM, host_af);
2903 if (sock < 0) return;
2904
2905 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2906 {
2907 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2908 strerror(errno));
2909 goto END_OFF;
2910 }
2911
2912 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2913 < 0)
2914 {
2915 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2916 {
2917 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2918 sender_host_address);
2919 }
2920 else
2921 {
2922 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2923 sender_host_address, strerror(errno));
2924 }
2925 goto END_OFF;
2926 }
2927
2928 /* Construct and send the query. */
2929
2930 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2931 qlen = Ustrlen(buffer);
2932 if (send(sock, buffer, qlen, 0) < 0)
2933 {
2934 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2935 goto END_OFF;
2936 }
2937
2938 /* Read a response line. We put it into the rest of the buffer, using several
2939 recv() calls if necessary. */
2940
2941 p = buffer + qlen;
2942
2943 for (;;)
2944 {
2945 uschar *pp;
2946 int count;
2947 int size = sizeof(buffer) - (p - buffer);
2948
2949 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2950 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2951 if (count <= 0) goto END_OFF; /* Read error or EOF */
2952
2953 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2954 generous, and accept a plain \n terminator as well. The only illegal
2955 character is 0. */
2956
2957 for (pp = p; pp < p + count; pp++)
2958 {
2959 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2960 if (*pp == '\n')
2961 {
2962 if (pp[-1] == '\r') pp--;
2963 *pp = 0;
2964 goto GOT_DATA; /* Break out of both loops */
2965 }
2966 }
2967
2968 /* Reached the end of the data without finding \n. Let the loop continue to
2969 read some more, if there is room. */
2970
2971 p = pp;
2972 }
2973
2974 GOT_DATA:
2975
2976 /* We have received a line of data. Check it carefully. It must start with the
2977 same two port numbers that we sent, followed by data as defined by the RFC. For
2978 example,
2979
2980 12345 , 25 : USERID : UNIX :root
2981
2982 However, the amount of white space may be different to what we sent. In the
2983 "osname" field there may be several sub-fields, comma separated. The data we
2984 actually want to save follows the third colon. Some systems put leading spaces
2985 in it - we discard those. */
2986
2987 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2988 &received_interface_port, &n) != 2 ||
2989 received_sender_port != sender_host_port ||
2990 received_interface_port != interface_port)
2991 goto END_OFF;
2992
2993 p = buffer + qlen + n;
2994 while(isspace(*p)) p++;
2995 if (*p++ != ':') goto END_OFF;
2996 while(isspace(*p)) p++;
2997 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2998 p += 6;
2999 while(isspace(*p)) p++;
3000 if (*p++ != ':') goto END_OFF;
3001 while (*p != 0 && *p != ':') p++;
3002 if (*p++ == 0) goto END_OFF;
3003 while(isspace(*p)) p++;
3004 if (*p == 0) goto END_OFF;
3005
3006 /* The rest of the line is the data we want. We turn it into printing
3007 characters when we save it, so that it cannot mess up the format of any logging
3008 or Received: lines into which it gets inserted. We keep a maximum of 127
3009 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
3010
3011 sender_ident = US string_printing(string_copyn(p, 127));
3012 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
3013
3014 END_OFF:
3015 (void)close(sock);
3016 return;
3017 }
3018
3019
3020
3021
3022 /*************************************************
3023 * Match host to a single host-list item *
3024 *************************************************/
3025
3026 /* This function compares a host (name or address) against a single item
3027 from a host list. The host name gets looked up if it is needed and is not
3028 already known. The function is called from verify_check_this_host() via
3029 match_check_list(), which is why most of its arguments are in a single block.
3030
3031 Arguments:
3032 arg the argument block (see below)
3033 ss the host-list item
3034 valueptr where to pass back looked up data, or NULL
3035 error for error message when returning ERROR
3036
3037 The block contains:
3038 host_name (a) the host name, or
3039 (b) NULL, implying use sender_host_name and
3040 sender_host_aliases, looking them up if required, or
3041 (c) the empty string, meaning that only IP address matches
3042 are permitted
3043 host_address the host address
3044 host_ipv4 the IPv4 address taken from an IPv6 one
3045
3046 Returns: OK matched
3047 FAIL did not match
3048 DEFER lookup deferred
3049 ERROR (a) failed to find the host name or IP address, or
3050 (b) unknown lookup type specified, or
3051 (c) host name encountered when only IP addresses are
3052 being matched
3053 */
3054
3055 int
3056 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
3057 {
3058 check_host_block *cb = (check_host_block *)arg;
3059 int mlen = -1;
3060 int maskoffset;
3061 BOOL iplookup = FALSE;
3062 BOOL isquery = FALSE;
3063 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
3064 const uschar *t;
3065 uschar *semicolon;
3066 uschar **aliases;
3067
3068 /* Optimize for the special case when the pattern is "*". */
3069
3070 if (*ss == '*' && ss[1] == 0) return OK;
3071
3072 /* If the pattern is empty, it matches only in the case when there is no host -
3073 this can occur in ACL checking for SMTP input using the -bs option. In this
3074 situation, the host address is the empty string. */
3075
3076 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
3077 if (*ss == 0) return FAIL;
3078
3079 /* If the pattern is precisely "@" then match against the primary host name,
3080 provided that host name matching is permitted; if it's "@[]" match against the
3081 local host's IP addresses. */
3082
3083 if (*ss == '@')
3084 {
3085 if (ss[1] == 0)
3086 {
3087 if (isiponly) return ERROR;
3088 ss = primary_hostname;
3089 }
3090 else if (Ustrcmp(ss, "@[]") == 0)
3091 {
3092 ip_address_item *ip;
3093 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
3094 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
3095 return FAIL;
3096 }
3097 }
3098
3099 /* If the pattern is an IP address, optionally followed by a bitmask count, do
3100 a (possibly masked) comparision with the current IP address. */
3101
3102 if (string_is_ip_address(ss, &maskoffset) != 0)
3103 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
3104
3105 /* The pattern is not an IP address. A common error that people make is to omit
3106 one component of an IPv4 address, either by accident, or believing that, for
3107 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,
3108 which it isn't. (Those applications that do accept 1.2.3 as an IP address
3109 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
3110 ancient specification.) To aid in debugging these cases, we give a specific
3111 error if the pattern contains only digits and dots or contains a slash preceded
3112 only by digits and dots (a slash at the start indicates a file name and of
3113 course slashes may be present in lookups, but not preceded only by digits and
3114 dots). */
3115
3116 for (t = ss; isdigit(*t) || *t == '.'; t++);
3117 if (*t == 0 || (*t == '/' && t != ss))
3118 {
3119 *error = US"malformed IPv4 address or address mask";
3120 return ERROR;
3121 }
3122
3123 /* See if there is a semicolon in the pattern */
3124
3125 semicolon = Ustrchr(ss, ';');
3126
3127 /* If we are doing an IP address only match, then all lookups must be IP
3128 address lookups, even if there is no "net-". */
3129
3130 if (isiponly)
3131 {
3132 iplookup = semicolon != NULL;
3133 }
3134
3135 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
3136 a lookup on a masked IP network, in textual form. We obey this code even if we
3137 have already set iplookup, so as to skip over the "net-" prefix and to set the
3138 mask length. The net- stuff really only applies to single-key lookups where the
3139 key is implicit. For query-style lookups the key is specified in the query.
3140 From release 4.30, the use of net- for query style is no longer needed, but we
3141 retain it for backward compatibility. */
3142
3143 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
3144 {
3145 mlen = 0;
3146 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
3147 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
3148 iplookup = (*t++ == '-');
3149 }
3150 else t = ss;
3151
3152 /* Do the IP address lookup if that is indeed what we have */
3153
3154 if (iplookup)
3155 {
3156 int insize;
3157 int search_type;
3158 int incoming[4];
3159 void *handle;
3160 uschar *filename, *key, *result;
3161 uschar buffer[64];
3162
3163 /* Find the search type */
3164
3165 search_type = search_findtype(t, semicolon - t);
3166
3167 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3168 search_error_message);
3169
3170 /* Adjust parameters for the type of lookup. For a query-style lookup, there
3171 is no file name, and the "key" is just the query. For query-style with a file
3172 name, we have to fish the file off the start of the query. For a single-key
3173 lookup, the key is the current IP address, masked appropriately, and
3174 reconverted to text form, with the mask appended. For IPv6 addresses, specify
3175 dot separators instead of colons, except when the lookup type is "iplsearch".
3176 */
3177
3178 if (mac_islookup(search_type, lookup_absfilequery))
3179 {
3180 filename = semicolon + 1;
3181 key = filename;
3182 while (*key != 0 && !isspace(*key)) key++;
3183 filename = string_copyn(filename, key - filename);
3184 while (isspace(*key)) key++;
3185 }
3186 else if (mac_islookup(search_type, lookup_querystyle))
3187 {
3188 filename = NULL;
3189 key = semicolon + 1;
3190 }
3191 else /* Single-key style */
3192 {
3193 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3194 ':' : '.';
3195 insize = host_aton(cb->host_address, incoming);
3196 host_mask(insize, incoming, mlen);
3197 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3198 key = buffer;
3199 filename = semicolon + 1;
3200 }
3201
3202 /* Now do the actual lookup; note that there is no search_close() because
3203 of the caching arrangements. */
3204
3205 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
3206 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
3207
3208 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3209 if (valueptr != NULL) *valueptr = result;
3210 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3211 }
3212
3213 /* The pattern is not an IP address or network reference of any kind. That is,
3214 it is a host name pattern. If this is an IP only match, there's an error in the
3215 host list. */
3216
3217 if (isiponly)
3218 {
3219 *error = US"cannot match host name in match_ip list";
3220 return ERROR;
3221 }
3222
3223 /* Check the characters of the pattern to see if they comprise only letters,
3224 digits, full stops, and hyphens (the constituents of domain names). Allow
3225 underscores, as they are all too commonly found. Sigh. Also, if
3226 allow_utf8_domains is set, allow top-bit characters. */
3227
3228 for (t = ss; *t != 0; t++)
3229 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3230 (!allow_utf8_domains || *t < 128)) break;
3231
3232 /* If the pattern is a complete domain name, with no fancy characters, look up
3233 its IP address and match against that. Note that a multi-homed host will add
3234 items to the chain. */
3235
3236 if (*t == 0)
3237 {
3238 int rc;
3239 host_item h;
3240 h.next = NULL;
3241 h.name = ss;
3242 h.address = NULL;
3243 h.mx = MX_NONE;
3244
3245 /* Using byname rather than bydns here means we cannot determine dnssec
3246 status. On the other hand it is unclear how that could be either
3247 propagated up or enforced. */
3248
3249 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3250 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3251 {
3252 host_item *hh;
3253 for (hh = &h; hh != NULL; hh = hh->next)
3254 {
3255 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3256 }
3257 return FAIL;
3258 }
3259 if (rc == HOST_FIND_AGAIN) return DEFER;
3260 *error = string_sprintf("failed to find IP address for %s", ss);
3261 return ERROR;
3262 }
3263
3264 /* Almost all subsequent comparisons require the host name, and can be done
3265 using the general string matching function. When this function is called for
3266 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3267 must use sender_host_name and its aliases, looking them up if necessary. */
3268
3269 if (cb->host_name != NULL) /* Explicit host name given */
3270 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3271 valueptr);
3272
3273 /* Host name not given; in principle we need the sender host name and its
3274 aliases. However, for query-style lookups, we do not need the name if the
3275 query does not contain $sender_host_name. From release 4.23, a reference to
3276 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3277 on spec. */
3278
3279 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3280 {
3281 const uschar *affix;
3282 int partial, affixlen, starflags, id;
3283
3284 *semicolon = 0;
3285 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3286 *semicolon=';';
3287
3288 if (id < 0) /* Unknown lookup type */
3289 {
3290 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3291 search_error_message, ss);
3292 return DEFER;
3293 }
3294 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3295 }
3296
3297 if (isquery)
3298 {
3299 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3300 {
3301 case OK: return OK;
3302 case DEFER: return DEFER;
3303 default: return FAIL;
3304 }
3305 }
3306
3307 /* Not a query-style lookup; must ensure the host name is present, and then we
3308 do a check on the name and all its aliases. */
3309
3310 if (sender_host_name == NULL)
3311 {
3312 HDEBUG(D_host_lookup)
3313 debug_printf("sender host name required, to match against %s\n", ss);
3314 if (host_lookup_failed || host_name_lookup() != OK)
3315 {
3316 *error = string_sprintf("failed to find host name for %s",
3317 sender_host_address);;
3318 return ERROR;
3319 }
3320 host_build_sender_fullhost();
3321 }
3322
3323 /* Match on the sender host name, using the general matching function */
3324
3325 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3326 valueptr))
3327 {
3328 case OK: return OK;
3329 case DEFER: return DEFER;
3330 }
3331
3332 /* If there are aliases, try matching on them. */
3333
3334 aliases = sender_host_aliases;
3335 while (*aliases != NULL)
3336 {
3337 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3338 {
3339 case OK: return OK;
3340 case DEFER: return DEFER;
3341 }
3342 }
3343 return FAIL;
3344 }
3345
3346
3347
3348
3349 /*************************************************
3350 * Check a specific host matches a host list *
3351 *************************************************/
3352
3353 /* This function is passed a host list containing items in a number of
3354 different formats and the identity of a host. Its job is to determine whether
3355 the given host is in the set of hosts defined by the list. The host name is
3356 passed as a pointer so that it can be looked up if needed and not already
3357 known. This is commonly the case when called from verify_check_host() to check
3358 an incoming connection. When called from elsewhere the host name should usually
3359 be set.
3360
3361 This function is now just a front end to match_check_list(), which runs common
3362 code for scanning a list. We pass it the check_host() function to perform a
3363 single test.
3364
3365 Arguments:
3366 listptr pointer to the host list
3367 cache_bits pointer to cache for named lists, or NULL
3368 host_name the host name or NULL, implying use sender_host_name and
3369 sender_host_aliases, looking them up if required
3370 host_address the IP address
3371 valueptr if not NULL, data from a lookup is passed back here
3372
3373 Returns: OK if the host is in the defined set
3374 FAIL if the host is not in the defined set,
3375 DEFER if a data lookup deferred (not a host lookup)
3376
3377 If the host name was needed in order to make a comparison, and could not be
3378 determined from the IP address, the result is FAIL unless the item
3379 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3380
3381 int
3382 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3383 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3384 {
3385 int rc;
3386 unsigned int *local_cache_bits = cache_bits;
3387 const uschar *save_host_address = deliver_host_address;
3388 check_host_block cb;
3389 cb.host_name = host_name;
3390 cb.host_address = host_address;
3391
3392 if (valueptr != NULL) *valueptr = NULL;
3393
3394 /* If the host address starts off ::ffff: it is an IPv6 address in
3395 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3396 addresses. */
3397
3398 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3399 host_address + 7 : host_address;
3400
3401 /* During the running of the check, put the IP address into $host_address. In
3402 the case of calls from the smtp transport, it will already be there. However,
3403 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3404 the safe side, any existing setting is preserved, though as I write this
3405 (November 2004) I can't see any cases where it is actually needed. */
3406
3407 deliver_host_address = host_address;
3408 rc = match_check_list(
3409 listptr, /* the list */
3410 0, /* separator character */
3411 &hostlist_anchor, /* anchor pointer */
3412 &local_cache_bits, /* cache pointer */
3413 check_host, /* function for testing */
3414 &cb, /* argument for function */
3415 MCL_HOST, /* type of check */
3416 (host_address == sender_host_address)?
3417 US"host" : host_address, /* text for debugging */
3418 valueptr); /* where to pass back data */
3419 deliver_host_address = save_host_address;
3420 return rc;
3421 }
3422
3423
3424
3425
3426 /*************************************************
3427 * Check the given host item matches a list *
3428 *************************************************/
3429 int
3430 verify_check_given_host(uschar **listptr, host_item *host)
3431 {
3432 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3433 }
3434
3435 /*************************************************
3436 * Check the remote host matches a list *
3437 *************************************************/
3438
3439 /* This is a front end to verify_check_this_host(), created because checking
3440 the remote host is a common occurrence. With luck, a good compiler will spot
3441 the tail recursion and optimize it. If there's no host address, this is
3442 command-line SMTP input - check against an empty string for the address.
3443
3444 Arguments:
3445 listptr pointer to the host list
3446
3447 Returns: the yield of verify_check_this_host(),
3448 i.e. OK, FAIL, or DEFER
3449 */
3450
3451 int
3452 verify_check_host(uschar **listptr)
3453 {
3454 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3455 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3456 }
3457
3458
3459
3460
3461
3462 /*************************************************
3463 * Invert an IP address *
3464 *************************************************/
3465
3466 /* Originally just used for DNS xBL lists, now also used for the
3467 reverse_ip expansion operator.
3468
3469 Arguments:
3470 buffer where to put the answer
3471 address the address to invert
3472 */
3473
3474 void
3475 invert_address(uschar *buffer, uschar *address)
3476 {
3477 int bin[4];
3478 uschar *bptr = buffer;
3479
3480 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3481 to the IPv4 part only. */
3482
3483 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3484
3485 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3486 always 1. */
3487
3488 if (host_aton(address, bin) == 1)
3489 {
3490 int i;
3491 int x = bin[0];
3492 for (i = 0; i < 4; i++)
3493 {
3494 sprintf(CS bptr, "%d.", x & 255);
3495 while (*bptr) bptr++;
3496 x >>= 8;
3497 }
3498 }
3499
3500 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3501 in any DNS black lists, and the format in which they will be looked up is
3502 unknown. This is just a guess. */
3503
3504 #if HAVE_IPV6
3505 else
3506 {
3507 int i, j;
3508 for (j = 3; j >= 0; j--)
3509 {
3510 int x = bin[j];
3511 for (i = 0; i < 8; i++)
3512 {
3513 sprintf(CS bptr, "%x.", x & 15);
3514 while (*bptr) bptr++;
3515 x >>= 4;
3516 }
3517 }
3518 }
3519 #endif
3520
3521 /* Remove trailing period -- this is needed so that both arbitrary
3522 dnsbl keydomains and inverted addresses may be combined with the
3523 same format string, "%s.%s" */
3524
3525 *(--bptr) = 0;
3526 }
3527
3528
3529
3530 /*************************************************
3531 * Perform a single dnsbl lookup *
3532 *************************************************/
3533
3534 /* This function is called from verify_check_dnsbl() below. It is also called
3535 recursively from within itself when domain and domain_txt are different
3536 pointers, in order to get the TXT record from the alternate domain.
3537
3538 Arguments:
3539 domain the outer dnsbl domain
3540 domain_txt alternate domain to lookup TXT record on success; when the
3541 same domain is to be used, domain_txt == domain (that is,
3542 the pointers must be identical, not just the text)
3543 keydomain the current keydomain (for debug message)
3544 prepend subdomain to lookup (like keydomain, but
3545 reversed if IP address)
3546 iplist the list of matching IP addresses, or NULL for "any"
3547 bitmask true if bitmask matching is wanted
3548 match_type condition for 'succeed' result
3549 0 => Any RR in iplist (=)
3550 1 => No RR in iplist (!=)
3551 2 => All RRs in iplist (==)
3552 3 => Some RRs not in iplist (!==)
3553 the two bits are defined as MT_NOT and MT_ALL
3554 defer_return what to return for a defer
3555
3556 Returns: OK if lookup succeeded
3557 FAIL if not
3558 */
3559
3560 static int
3561 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3562 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3563 int defer_return)
3564 {
3565 dns_answer dnsa;
3566 dns_scan dnss;
3567 tree_node *t;
3568 dnsbl_cache_block *cb;
3569 int old_pool = store_pool;
3570 uschar query[256]; /* DNS domain max length */
3571
3572 /* Construct the specific query domainname */
3573
3574 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3575 {
3576 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3577 "(ignored): %s...", query);
3578 return FAIL;
3579 }
3580
3581 /* Look for this query in the cache. */
3582
3583 if ( (t = tree_search(dnsbl_cache, query))
3584 && (cb = t->data.ptr)->expiry > time(NULL)
3585 )
3586
3587 /* Previous lookup was cached */
3588
3589 {
3590 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3591 }
3592
3593 /* If not cached from a previous lookup, we must do a DNS lookup, and
3594 cache the result in permanent memory. */
3595
3596 else
3597 {
3598 uint ttl = 3600;
3599
3600 store_pool = POOL_PERM;
3601
3602 if (t)
3603 {
3604 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3605 }
3606
3607 else
3608 { /* Set up a tree entry to cache the lookup */
3609 t = store_get(sizeof(tree_node) + Ustrlen(query));
3610 Ustrcpy(t->name, query);
3611 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3612 (void)tree_insertnode(&dnsbl_cache, t);
3613 }
3614
3615 /* Do the DNS loopup . */
3616
3617 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3618 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3619 cb->text_set = FALSE;
3620 cb->text = NULL;
3621 cb->rhs = NULL;
3622
3623 /* If the lookup succeeded, cache the RHS address. The code allows for
3624 more than one address - this was for complete generality and the possible
3625 use of A6 records. However, A6 records have been reduced to experimental
3626 status (August 2001) and may die out. So they may never get used at all,
3627 let alone in dnsbl records. However, leave the code here, just in case.
3628
3629 Quite apart from one A6 RR generating multiple addresses, there are DNS
3630 lists that return more than one A record, so we must handle multiple
3631 addresses generated in that way as well.
3632
3633 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3634 or some suitably far-future time if none were found. */
3635
3636 if (cb->rc == DNS_SUCCEED)
3637 {
3638 dns_record *rr;
3639 dns_address **addrp = &(cb->rhs);
3640 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3641 rr;
3642 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3643 {
3644 if (rr->type == T_A)
3645 {
3646 dns_address *da = dns_address_from_rr(&dnsa, rr);
3647 if (da)
3648 {
3649 *addrp = da;
3650 while (da->next != NULL) da = da->next;
3651 addrp = &(da->next);
3652 if (ttl > rr->ttl) ttl = rr->ttl;
3653 }
3654 }
3655 }
3656
3657 /* If we didn't find any A records, change the return code. This can
3658 happen when there is a CNAME record but there are no A records for what
3659 it points to. */
3660
3661 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3662 }
3663
3664 cb->expiry = time(NULL)+ttl;
3665 store_pool = old_pool;
3666 }
3667
3668 /* We now have the result of the DNS lookup, either newly done, or cached
3669 from a previous call. If the lookup succeeded, check against the address
3670 list if there is one. This may be a positive equality list (introduced by
3671 "="), a negative equality list (introduced by "!="), a positive bitmask
3672 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3673
3674 if (cb->rc == DNS_SUCCEED)
3675 {
3676 dns_address *da = NULL;
3677 uschar *addlist = cb->rhs->address;
3678
3679 /* For A and AAAA records, there may be multiple addresses from multiple
3680 records. For A6 records (currently not expected to be used) there may be
3681 multiple addresses from a single record. */
3682
3683 for (da = cb->rhs->next; da != NULL; da = da->next)
3684 addlist = string_sprintf("%s, %s", addlist, da->address);
3685
3686 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3687 query, addlist);
3688
3689 /* Address list check; this can be either for equality, or via a bitmask.
3690 In the latter case, all the bits must match. */
3691
3692 if (iplist != NULL)
3693 {
3694 for (da = cb->rhs; da != NULL; da = da->next)
3695 {
3696 int ipsep = ',';
3697 uschar ip[46];
3698 const uschar *ptr = iplist;
3699 uschar *res;
3700
3701 /* Handle exact matching */
3702
3703 if (!bitmask)
3704 {
3705 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3706 {
3707 if (Ustrcmp(CS da->address, ip) == 0) break;
3708 }
3709 }
3710
3711 /* Handle bitmask matching */
3712
3713 else
3714 {
3715 int address[4];
3716 int mask = 0;
3717
3718 /* At present, all known DNS blocking lists use A records, with
3719 IPv4 addresses on the RHS encoding the information they return. I
3720 wonder if this will linger on as the last vestige of IPv4 when IPv6
3721 is ubiquitous? Anyway, for now we use paranoia code to completely
3722 ignore IPv6 addresses. The default mask is 0, which always matches.
3723 We change this only for IPv4 addresses in the list. */
3724
3725 if (host_aton(da->address, address) == 1) mask = address[0];
3726
3727 /* Scan the returned addresses, skipping any that are IPv6 */
3728
3729 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3730 {
3731 if (host_aton(ip, address) != 1) continue;
3732 if ((address[0] & mask) == address[0]) break;
3733 }
3734 }
3735
3736 /* If either
3737
3738 (a) An IP address in an any ('=') list matched, or
3739 (b) No IP address in an all ('==') list matched
3740
3741 then we're done searching. */
3742
3743 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3744 }
3745
3746 /* If da == NULL, either
3747
3748 (a) No IP address in an any ('=') list matched, or
3749 (b) An IP address in an all ('==') list didn't match
3750
3751 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3752 the list. */
3753
3754 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3755 {
3756 HDEBUG(D_dnsbl)
3757 {
3758 uschar *res = NULL;
3759 switch(match_type)
3760 {
3761 case 0:
3762 res = US"was no match";
3763 break;
3764 case MT_NOT:
3765 res = US"was an exclude match";
3766 break;
3767 case MT_ALL:
3768 res = US"was an IP address that did not match";
3769 break;
3770 case MT_NOT|MT_ALL:
3771 res = US"were no IP addresses that did not match";
3772 break;
3773 }
3774 debug_printf("=> but we are not accepting this block class because\n");
3775 debug_printf("=> there %s for %s%c%s\n",
3776 res,
3777 ((match_type & MT_ALL) == 0)? "" : "=",
3778 bitmask? '&' : '=', iplist);
3779 }
3780 return FAIL;
3781 }
3782 }
3783
3784 /* Either there was no IP list, or the record matched, implying that the
3785 domain is on the list. We now want to find a corresponding TXT record. If an
3786 alternate domain is specified for the TXT record, call this function
3787 recursively to look that up; this has the side effect of re-checking that
3788 there is indeed an A record at the alternate domain. */
3789
3790 if (domain_txt != domain)
3791 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3792 FALSE, match_type, defer_return);
3793
3794 /* If there is no alternate domain, look up a TXT record in the main domain
3795 if it has not previously been cached. */
3796
3797 if (!cb->text_set)
3798 {
3799 cb->text_set = TRUE;
3800 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3801 {
3802 dns_record *rr;
3803 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3804 rr != NULL;
3805 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3806 if (rr->type == T_TXT) break;
3807 if (rr != NULL)
3808 {
3809 int len = (rr->data)[0];
3810 if (len > 511) len = 127;
3811 store_pool = POOL_PERM;
3812 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3813 store_pool = old_pool;
3814 }
3815 }
3816 }
3817
3818 dnslist_value = addlist;
3819 dnslist_text = cb->text;
3820 return OK;
3821 }
3822
3823 /* There was a problem with the DNS lookup */
3824
3825 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3826 {
3827 log_write(L_dnslist_defer, LOG_MAIN,
3828 "DNS list lookup defer (probably timeout) for %s: %s", query,
3829 (defer_return == OK)? US"assumed in list" :
3830 (defer_return == FAIL)? US"assumed not in list" :
3831 US"returned DEFER");
3832 return defer_return;
3833 }
3834
3835 /* No entry was found in the DNS; continue for next domain */
3836
3837 HDEBUG(D_dnsbl)
3838 {
3839 debug_printf("DNS lookup for %s failed\n", query);
3840 debug_printf("=> that means %s is not listed at %s\n",
3841 keydomain, domain);
3842 }
3843
3844 return FAIL;
3845 }
3846
3847
3848
3849
3850 /*************************************************
3851 * Check host against DNS black lists *
3852 *************************************************/
3853
3854 /* This function runs checks against a list of DNS black lists, until one
3855 matches. Each item on the list can be of the form
3856
3857 domain=ip-address/key
3858
3859 The domain is the right-most domain that is used for the query, for example,
3860 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3861 if the DNS lookup returns a matching IP address. Several addresses may be
3862 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3863
3864 If no key is given, what is looked up in the domain is the inverted IP address
3865 of the current client host. If a key is given, it is used to construct the
3866 domain for the lookup. For example:
3867
3868 dsn.rfc-ignorant.org/$sender_address_domain
3869
3870 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3871 then we check for a TXT record for an error message, and if found, save its
3872 value in $dnslist_text. We also cache everything in a tree, to optimize
3873 multiple lookups.
3874
3875 The TXT record is normally looked up in the same domain as the A record, but
3876 when many lists are combined in a single DNS domain, this will not be a very
3877 specific message. It is possible to specify a different domain for looking up
3878 TXT records; this is given before the main domain, comma-separated. For
3879 example:
3880
3881 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3882 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3883
3884 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3885
3886 Note: an address for testing RBL is 192.203.178.39
3887 Note: an address for testing DUL is 192.203.178.4
3888 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3889
3890 Arguments:
3891 where the acl type
3892 listptr the domain/address/data list
3893 log_msgptr log message on error
3894
3895 Returns: OK successful lookup (i.e. the address is on the list), or
3896 lookup deferred after +include_unknown
3897 FAIL name not found, or no data found for the given type, or
3898 lookup deferred after +exclude_unknown (default)
3899 DEFER lookup failure, if +defer_unknown was set
3900 */
3901
3902 int
3903 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3904 {
3905 int sep = 0;
3906 int defer_return = FAIL;
3907 const uschar *list = *listptr;
3908 uschar *domain;
3909 uschar *s;
3910 uschar buffer[1024];
3911 uschar revadd[128]; /* Long enough for IPv6 address */
3912
3913 /* Indicate that the inverted IP address is not yet set up */
3914
3915 revadd[0] = 0;
3916
3917 /* In case this is the first time the DNS resolver is being used. */
3918
3919 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3920
3921 /* Loop through all the domains supplied, until something matches */
3922
3923 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3924 {
3925 int rc;
3926 BOOL bitmask = FALSE;
3927 int match_type = 0;
3928 uschar *domain_txt;
3929 uschar *comma;
3930 uschar *iplist;
3931 uschar *key;
3932
3933 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3934
3935 /* Deal with special values that change the behaviour on defer */
3936
3937 if (domain[0] == '+')
3938 {
3939 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3940 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3941 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3942 else
3943 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3944 domain);
3945 continue;
3946 }
3947
3948 /* See if there's explicit data to be looked up */
3949
3950 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3951
3952 /* See if there's a list of addresses supplied after the domain name. This is
3953 introduced by an = or a & character; if preceded by = we require all matches
3954 and if preceded by ! we invert the result. */
3955
3956 if (!(iplist = Ustrchr(domain, '=')))
3957 {
3958 bitmask = TRUE;
3959 iplist = Ustrchr(domain, '&');
3960 }
3961
3962 if (iplist) /* Found either = or & */
3963 {
3964 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3965 {
3966 match_type |= MT_NOT;
3967 iplist[-1] = 0;
3968 }
3969
3970 *iplist++ = 0; /* Terminate domain, move on */
3971
3972 /* If we found = (bitmask == FALSE), check for == or =& */
3973
3974 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3975 {
3976 bitmask = *iplist++ == '&';
3977 match_type |= MT_ALL;
3978 }
3979 }
3980
3981
3982 /* If there is a comma in the domain, it indicates that a second domain for
3983 looking up TXT records is provided, before the main domain. Otherwise we must
3984 set domain_txt == domain. */
3985
3986 domain_txt = domain;
3987 comma = Ustrchr(domain, ',');
3988 if (comma != NULL)
3989 {
3990 *comma++ = 0;
3991 domain = comma;
3992 }
3993
3994 /* Check that what we have left is a sensible domain name. There is no reason
3995 why these domains should in fact use the same syntax as hosts and email
3996 domains, but in practice they seem to. However, there is little point in
3997 actually causing an error here, because that would no doubt hold up incoming
3998 mail. Instead, I'll just log it. */
3999
4000 for (s = domain; *s != 0; s++)
4001 {
4002 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
4003 {
4004 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
4005 "strange characters - is this right?", domain);
4006 break;
4007 }
4008 }
4009
4010 /* Check the alternate domain if present */
4011
4012 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
4013 {
4014 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
4015 {
4016 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
4017 "strange characters - is this right?", domain_txt);
4018 break;
4019 }
4020 }
4021
4022 /* If there is no key string, construct the query by adding the domain name
4023 onto the inverted host address, and perform a single DNS lookup. */
4024
4025 if (key == NULL)
4026 {
4027 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
4028 {
4029 *log_msgptr = string_sprintf
4030 ("cannot test auto-keyed dnslists condition in %s ACL",
4031 acl_wherenames[where]);
4032 return ERROR;
4033 }
4034 if (sender_host_address == NULL) return FAIL; /* can never match */
4035 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
4036 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
4037 iplist, bitmask, match_type, defer_return);
4038 if (rc == OK)
4039 {
4040 dnslist_domain = string_copy(domain_txt);
4041 dnslist_matched = string_copy(sender_host_address);
4042 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4043 sender_host_address, dnslist_domain);
4044 }
4045 if (rc != FAIL) return rc; /* OK or DEFER */
4046 }
4047
4048 /* If there is a key string, it can be a list of domains or IP addresses to
4049 be concatenated with the main domain. */
4050
4051 else
4052 {
4053 int keysep = 0;
4054 BOOL defer = FALSE;
4055 uschar *keydomain;
4056 uschar keybuffer[256];
4057 uschar keyrevadd[128