6c6e6d61862a79b0700981369221398e04bcbb07
[exim.git] / src / src / verify.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2015 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
10
11
12 #include "exim.h"
13 #include "transports/smtp.h"
14
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
19
20
21 /* Structure for caching DNSBL lookups */
22
23 typedef struct dnsbl_cache_block {
24 dns_address *rhs;
25 uschar *text;
26 int rc;
27 BOOL text_set;
28 } dnsbl_cache_block;
29
30
31 /* Anchor for DNSBL cache */
32
33 static tree_node *dnsbl_cache = NULL;
34
35
36 /* Bits for match_type in one_check_dnsbl() */
37
38 #define MT_NOT 1
39 #define MT_ALL 2
40
41 static uschar cutthrough_response(char, uschar **);
42
43
44 /*************************************************
45 * Retrieve a callout cache record *
46 *************************************************/
47
48 /* If a record exists, check whether it has expired.
49
50 Arguments:
51 dbm_file an open hints file
52 key the record key
53 type "address" or "domain"
54 positive_expire expire time for positive records
55 negative_expire expire time for negative records
56
57 Returns: the cache record if a non-expired one exists, else NULL
58 */
59
60 static dbdata_callout_cache *
61 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
62 int positive_expire, int negative_expire)
63 {
64 BOOL negative;
65 int length, expire;
66 time_t now;
67 dbdata_callout_cache *cache_record;
68
69 cache_record = dbfn_read_with_length(dbm_file, key, &length);
70
71 if (cache_record == NULL)
72 {
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
74 return NULL;
75 }
76
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
79
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
83 now = time(NULL);
84
85 if (now - cache_record->time_stamp > expire)
86 {
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
88 return NULL;
89 }
90
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
96
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
98 {
99 if (length == sizeof(dbdata_callout_cache_obs))
100 {
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
104 cache_record = new;
105 }
106
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
109
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
112 }
113
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
115 return cache_record;
116 }
117
118
119
120 /*************************************************
121 * Do callout verification for an address *
122 *************************************************/
123
124 /* This function is called from verify_address() when the address has routed to
125 a host list, and a callout has been requested. Callouts are expensive; that is
126 why a cache is used to improve the efficiency.
127
128 Arguments:
129 addr the address that's been routed
130 host_list the list of hosts to try
131 tf the transport feedback block
132
133 ifstring "interface" option from transport, or NULL
134 portstring "port" option from transport, or NULL
135 protocolstring "protocol" option from transport, or NULL
136 callout the per-command callout timeout
137 callout_overall the overall callout timeout (if < 0 use 4*callout)
138 callout_connect the callout connection timeout (if < 0 use callout)
139 options the verification options - these bits are used:
140 vopt_is_recipient => this is a recipient address
141 vopt_callout_no_cache => don't use callout cache
142 vopt_callout_fullpm => if postmaster check, do full one
143 vopt_callout_random => do the "random" thing
144 vopt_callout_recipsender => use real sender for recipient
145 vopt_callout_recippmaster => use postmaster for recipient
146 se_mailfrom MAIL FROM address for sender verify; NULL => ""
147 pm_mailfrom if non-NULL, do the postmaster check with this sender
148
149 Returns: OK/FAIL/DEFER
150 */
151
152 static int
153 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
154 int callout, int callout_overall, int callout_connect, int options,
155 uschar *se_mailfrom, uschar *pm_mailfrom)
156 {
157 BOOL is_recipient = (options & vopt_is_recipient) != 0;
158 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
159 BOOL callout_random = (options & vopt_callout_random) != 0;
160
161 int yield = OK;
162 int old_domain_cache_result = ccache_accept;
163 BOOL done = FALSE;
164 uschar *address_key;
165 uschar *from_address;
166 uschar *random_local_part = NULL;
167 const uschar *save_deliver_domain = deliver_domain;
168 uschar **failure_ptr = is_recipient?
169 &recipient_verify_failure : &sender_verify_failure;
170 open_db dbblock;
171 open_db *dbm_file = NULL;
172 dbdata_callout_cache new_domain_record;
173 dbdata_callout_cache_address new_address_record;
174 host_item *host;
175 time_t callout_start_time;
176 #ifdef EXPERIMENTAL_INTERNATIONAL
177 BOOL utf8_offered = FALSE;
178 #endif
179
180 new_domain_record.result = ccache_unknown;
181 new_domain_record.postmaster_result = ccache_unknown;
182 new_domain_record.random_result = ccache_unknown;
183
184 memset(&new_address_record, 0, sizeof(new_address_record));
185
186 /* For a recipient callout, the key used for the address cache record must
187 include the sender address if we are using the real sender in the callout,
188 because that may influence the result of the callout. */
189
190 address_key = addr->address;
191 from_address = US"";
192
193 if (is_recipient)
194 {
195 if (options & vopt_callout_recipsender)
196 {
197 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
198 from_address = sender_address;
199 }
200 else if (options & vopt_callout_recippmaster)
201 {
202 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
203 qualify_domain_sender);
204 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
205 }
206 }
207
208 /* For a sender callout, we must adjust the key if the mailfrom address is not
209 empty. */
210
211 else
212 {
213 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
214 if (from_address[0] != 0)
215 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
216 }
217
218 /* Open the callout cache database, it it exists, for reading only at this
219 stage, unless caching has been disabled. */
220
221 if (callout_no_cache)
222 {
223 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
224 }
225 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
226 {
227 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
228 }
229
230 /* If a cache database is available see if we can avoid the need to do an
231 actual callout by making use of previously-obtained data. */
232
233 if (dbm_file != NULL)
234 {
235 dbdata_callout_cache_address *cache_address_record;
236 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
237 addr->domain, US"domain",
238 callout_cache_domain_positive_expire,
239 callout_cache_domain_negative_expire);
240
241 /* If an unexpired cache record was found for this domain, see if the callout
242 process can be short-circuited. */
243
244 if (cache_record != NULL)
245 {
246 /* In most cases, if an early command (up to and including MAIL FROM:<>)
247 was rejected, there is no point carrying on. The callout fails. However, if
248 we are doing a recipient verification with use_sender or use_postmaster
249 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
250 will be using a non-empty sender. We have to remember this situation so as
251 not to disturb the cached domain value if this whole verification succeeds
252 (we don't want it turning into "accept"). */
253
254 old_domain_cache_result = cache_record->result;
255
256 if (cache_record->result == ccache_reject ||
257 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
258 {
259 setflag(addr, af_verify_nsfail);
260 HDEBUG(D_verify)
261 debug_printf("callout cache: domain gave initial rejection, or "
262 "does not accept HELO or MAIL FROM:<>\n");
263 setflag(addr, af_verify_nsfail);
264 addr->user_message = US"(result of an earlier callout reused).";
265 yield = FAIL;
266 *failure_ptr = US"mail";
267 goto END_CALLOUT;
268 }
269
270 /* If a previous check on a "random" local part was accepted, we assume
271 that the server does not do any checking on local parts. There is therefore
272 no point in doing the callout, because it will always be successful. If a
273 random check previously failed, arrange not to do it again, but preserve
274 the data in the new record. If a random check is required but hasn't been
275 done, skip the remaining cache processing. */
276
277 if (callout_random) switch(cache_record->random_result)
278 {
279 case ccache_accept:
280 HDEBUG(D_verify)
281 debug_printf("callout cache: domain accepts random addresses\n");
282 goto END_CALLOUT; /* Default yield is OK */
283
284 case ccache_reject:
285 HDEBUG(D_verify)
286 debug_printf("callout cache: domain rejects random addresses\n");
287 callout_random = FALSE;
288 new_domain_record.random_result = ccache_reject;
289 new_domain_record.random_stamp = cache_record->random_stamp;
290 break;
291
292 default:
293 HDEBUG(D_verify)
294 debug_printf("callout cache: need to check random address handling "
295 "(not cached or cache expired)\n");
296 goto END_CACHE;
297 }
298
299 /* If a postmaster check is requested, but there was a previous failure,
300 there is again no point in carrying on. If a postmaster check is required,
301 but has not been done before, we are going to have to do a callout, so skip
302 remaining cache processing. */
303
304 if (pm_mailfrom != NULL)
305 {
306 if (cache_record->postmaster_result == ccache_reject)
307 {
308 setflag(addr, af_verify_pmfail);
309 HDEBUG(D_verify)
310 debug_printf("callout cache: domain does not accept "
311 "RCPT TO:<postmaster@domain>\n");
312 yield = FAIL;
313 *failure_ptr = US"postmaster";
314 setflag(addr, af_verify_pmfail);
315 addr->user_message = US"(result of earlier verification reused).";
316 goto END_CALLOUT;
317 }
318 if (cache_record->postmaster_result == ccache_unknown)
319 {
320 HDEBUG(D_verify)
321 debug_printf("callout cache: need to check RCPT "
322 "TO:<postmaster@domain> (not cached or cache expired)\n");
323 goto END_CACHE;
324 }
325
326 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
327 postmaster check if the address itself has to be checked. Also ensure
328 that the value in the cache record is preserved (with its old timestamp).
329 */
330
331 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
332 "TO:<postmaster@domain>\n");
333 pm_mailfrom = NULL;
334 new_domain_record.postmaster_result = ccache_accept;
335 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
336 }
337 }
338
339 /* We can't give a result based on information about the domain. See if there
340 is an unexpired cache record for this specific address (combined with the
341 sender address if we are doing a recipient callout with a non-empty sender).
342 */
343
344 cache_address_record = (dbdata_callout_cache_address *)
345 get_callout_cache_record(dbm_file,
346 address_key, US"address",
347 callout_cache_positive_expire,
348 callout_cache_negative_expire);
349
350 if (cache_address_record != NULL)
351 {
352 if (cache_address_record->result == ccache_accept)
353 {
354 HDEBUG(D_verify)
355 debug_printf("callout cache: address record is positive\n");
356 }
357 else
358 {
359 HDEBUG(D_verify)
360 debug_printf("callout cache: address record is negative\n");
361 addr->user_message = US"Previous (cached) callout verification failure";
362 *failure_ptr = US"recipient";
363 yield = FAIL;
364 }
365 goto END_CALLOUT;
366 }
367
368 /* Close the cache database while we actually do the callout for real. */
369
370 END_CACHE:
371 dbfn_close(dbm_file);
372 dbm_file = NULL;
373 }
374
375 if (!addr->transport)
376 {
377 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
378 }
379 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
380 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
381 addr->transport->name, addr->transport->driver_name);
382 else
383 {
384 smtp_transport_options_block *ob =
385 (smtp_transport_options_block *)addr->transport->options_block;
386
387 /* The information wasn't available in the cache, so we have to do a real
388 callout and save the result in the cache for next time, unless no_cache is set,
389 or unless we have a previously cached negative random result. If we are to test
390 with a random local part, ensure that such a local part is available. If not,
391 log the fact, but carry on without randomming. */
392
393 if (callout_random && callout_random_local_part != NULL)
394 if (!(random_local_part = expand_string(callout_random_local_part)))
395 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
396 "callout_random_local_part: %s", expand_string_message);
397
398 /* Default the connect and overall callout timeouts if not set, and record the
399 time we are starting so that we can enforce it. */
400
401 if (callout_overall < 0) callout_overall = 4 * callout;
402 if (callout_connect < 0) callout_connect = callout;
403 callout_start_time = time(NULL);
404
405 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
406 output because a callout might take some time. When PIPELINING is active and
407 there are many recipients, the total time for doing lots of callouts can add up
408 and cause the client to time out. So in this case we forgo the PIPELINING
409 optimization. */
410
411 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
412
413 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
414 and we are holding a cutthrough conn open, we can just append the rcpt to
415 that conn for verification purposes (and later delivery also). Simplest
416 coding means skipping this whole loop and doing the append separately.
417
418 We will need to remember it has been appended so that rcpt-acl tail code
419 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
420 */
421
422 /* Can we re-use an open cutthrough connection? */
423 if ( cutthrough.fd >= 0
424 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
425 == vopt_callout_recipsender
426 && !random_local_part
427 && !pm_mailfrom
428 )
429 {
430 if (addr->transport == cutthrough.addr.transport)
431 for (host = host_list; host; host = host->next)
432 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
433 {
434 int host_af;
435 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
436 int port = 25;
437
438 deliver_host = host->name;
439 deliver_host_address = host->address;
440 deliver_host_port = host->port;
441 deliver_domain = addr->domain;
442 transport_name = addr->transport->name;
443
444 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
445
446 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
447 US"callout") ||
448 !smtp_get_port(tf->port, addr, &port, US"callout"))
449 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
450 addr->message);
451
452 if ( ( interface == cutthrough.interface
453 || ( interface
454 && cutthrough.interface
455 && Ustrcmp(interface, cutthrough.interface) == 0
456 ) )
457 && port == cutthrough.host.port
458 )
459 {
460 uschar * resp;
461
462 /* Match! Send the RCPT TO, append the addr, set done */
463 done =
464 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
465 transport_rcpt_address(addr,
466 (addr->transport == NULL)? FALSE :
467 addr->transport->rcpt_include_affixes)) >= 0 &&
468 cutthrough_response('2', &resp) == '2';
469
470 /* This would go horribly wrong if a callout fail was ignored by ACL.
471 We punt by abandoning cutthrough on a reject, like the
472 first-rcpt does. */
473
474 if (done)
475 {
476 address_item * na = store_get(sizeof(address_item));
477 *na = cutthrough.addr;
478 cutthrough.addr = *addr;
479 cutthrough.addr.host_used = &cutthrough.host;
480 cutthrough.addr.next = na;
481
482 cutthrough.nrcpt++;
483 }
484 else
485 {
486 cancel_cutthrough_connection("recipient rejected");
487 if (errno == ETIMEDOUT)
488 {
489 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
490 }
491 else if (errno == 0)
492 {
493 if (*resp == 0)
494 Ustrcpy(resp, US"connection dropped");
495
496 addr->message =
497 string_sprintf("response to \"%s\" from %s [%s] was: %s",
498 big_buffer, host->name, host->address,
499 string_printing(resp));
500
501 addr->user_message =
502 string_sprintf("Callout verification failed:\n%s", resp);
503
504 /* Hard rejection ends the process */
505
506 if (resp[0] == '5') /* Address rejected */
507 {
508 yield = FAIL;
509 done = TRUE;
510 }
511 }
512 }
513 }
514 break;
515 }
516 if (!done)
517 cancel_cutthrough_connection("incompatible connection");
518 }
519
520 /* Now make connections to the hosts and do real callouts. The list of hosts
521 is passed in as an argument. */
522
523 for (host = host_list; host != NULL && !done; host = host->next)
524 {
525 smtp_inblock inblock;
526 smtp_outblock outblock;
527 int host_af;
528 int port = 25;
529 BOOL send_quit = TRUE;
530 uschar *active_hostname = smtp_active_hostname;
531 BOOL lmtp;
532 BOOL smtps;
533 BOOL esmtp;
534 BOOL suppress_tls = FALSE;
535 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
536 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
537 BOOL dane = FALSE;
538 BOOL dane_required;
539 dns_answer tlsa_dnsa;
540 #endif
541 uschar inbuffer[4096];
542 uschar outbuffer[1024];
543 uschar responsebuffer[4096];
544
545 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
546 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
547
548 /* Skip this host if we don't have an IP address for it. */
549
550 if (host->address == NULL)
551 {
552 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
553 host->name);
554 continue;
555 }
556
557 /* Check the overall callout timeout */
558
559 if (time(NULL) - callout_start_time >= callout_overall)
560 {
561 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
562 break;
563 }
564
565 /* Set IPv4 or IPv6 */
566
567 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
568
569 /* Expand and interpret the interface and port strings. The latter will not
570 be used if there is a host-specific port (e.g. from a manualroute router).
571 This has to be delayed till now, because they may expand differently for
572 different hosts. If there's a failure, log it, but carry on with the
573 defaults. */
574
575 deliver_host = host->name;
576 deliver_host_address = host->address;
577 deliver_host_port = host->port;
578 deliver_domain = addr->domain;
579 transport_name = addr->transport->name;
580
581 if ( !smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
582 US"callout")
583 || !smtp_get_port(tf->port, addr, &port, US"callout")
584 )
585 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
586 addr->message);
587
588 /* Set HELO string according to the protocol */
589 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
590 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
591
592
593 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
594
595 /* Set up the buffer for reading SMTP response packets. */
596
597 inblock.buffer = inbuffer;
598 inblock.buffersize = sizeof(inbuffer);
599 inblock.ptr = inbuffer;
600 inblock.ptrend = inbuffer;
601
602 /* Set up the buffer for holding SMTP commands while pipelining */
603
604 outblock.buffer = outbuffer;
605 outblock.buffersize = sizeof(outbuffer);
606 outblock.ptr = outbuffer;
607 outblock.cmd_count = 0;
608 outblock.authenticating = FALSE;
609
610 /* Connect to the host; on failure, just loop for the next one, but we
611 set the error for the last one. Use the callout_connect timeout. */
612
613 tls_retry_connection:
614
615 /* Reset the parameters of a TLS session */
616 tls_out.cipher = tls_out.peerdn = tls_out.peercert = NULL;
617
618 inblock.sock = outblock.sock =
619 smtp_connect(host, host_af, port, interface, callout_connect,
620 addr->transport);
621 if (inblock.sock < 0)
622 {
623 addr->message = string_sprintf("could not connect to %s [%s]: %s",
624 host->name, host->address, strerror(errno));
625 transport_name = NULL;
626 deliver_host = deliver_host_address = NULL;
627 deliver_domain = save_deliver_domain;
628 continue;
629 }
630
631 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
632 {
633 int rc;
634
635 tls_out.dane_verified = FALSE;
636 tls_out.tlsa_usage = 0;
637
638 dane_required =
639 verify_check_given_host(&ob->hosts_require_dane, host) == OK;
640
641 if (host->dnssec == DS_YES)
642 {
643 if( ( dane_required
644 || verify_check_given_host(&ob->hosts_try_dane, host) == OK
645 )
646 && (rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK
647 )
648 return rc;
649 }
650 else if (dane_required)
651 {
652 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
653 return FAIL;
654 }
655
656 if (dane)
657 ob->tls_tempfail_tryclear = FALSE;
658 }
659 #endif /*DANE*/
660
661 /* Expand the helo_data string to find the host name to use. */
662
663 if (tf->helo_data != NULL)
664 {
665 uschar *s = expand_string(tf->helo_data);
666 if (s == NULL)
667 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
668 "helo_data value for callout: %s", addr->address,
669 expand_string_message);
670 else active_hostname = s;
671 }
672
673 /* Wait for initial response, and send HELO. The smtp_write_command()
674 function leaves its command in big_buffer. This is used in error responses.
675 Initialize it in case the connection is rejected. */
676
677 Ustrcpy(big_buffer, "initial connection");
678
679 /* Unless ssl-on-connect, wait for the initial greeting */
680 smtps_redo_greeting:
681
682 #ifdef SUPPORT_TLS
683 if (!smtps || (smtps && tls_out.active >= 0))
684 #endif
685 {
686 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
687 goto RESPONSE_FAILED;
688
689 #ifdef EXPERIMENTAL_EVENT
690 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
691 : host->dnssec==DS_NO ? US"no" : NULL;
692 if (event_raise(addr->transport->event_action,
693 US"smtp:connect", responsebuffer))
694 {
695 lookup_dnssec_authenticated = NULL;
696 /* Logging? Debug? */
697 goto RESPONSE_FAILED;
698 }
699 lookup_dnssec_authenticated = NULL;
700 #endif
701 }
702
703 /* Not worth checking greeting line for ESMTP support */
704 if (!(esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK))
705 DEBUG(D_transport)
706 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
707
708 tls_redo_helo:
709
710 #ifdef SUPPORT_TLS
711 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
712 {
713 tls_offered = TRUE;
714 ob->tls_tempfail_tryclear = FALSE;
715 }
716 else /* all other cases */
717 #endif
718
719 { esmtp_retry:
720
721 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
722 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
723 goto SEND_FAILED;
724 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
725 {
726 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
727 {
728 done= FALSE;
729 goto RESPONSE_FAILED;
730 }
731 #ifdef SUPPORT_TLS
732 tls_offered = FALSE;
733 #endif
734 esmtp = FALSE;
735 goto esmtp_retry; /* fallback to HELO */
736 }
737
738 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
739 #ifdef SUPPORT_TLS
740 if (esmtp && !suppress_tls && tls_out.active < 0)
741 {
742 if (regex_STARTTLS == NULL) regex_STARTTLS =
743 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
744
745 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
746 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
747 }
748 else
749 tls_offered = FALSE;
750 #endif
751 }
752
753 /* If TLS is available on this connection attempt to
754 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
755 send another EHLO - the server may give a different answer in secure mode. We
756 use a separate buffer for reading the response to STARTTLS so that if it is
757 negative, the original EHLO data is available for subsequent analysis, should
758 the client not be required to use TLS. If the response is bad, copy the buffer
759 for error analysis. */
760
761 #ifdef SUPPORT_TLS
762 if ( tls_offered
763 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK
764 && verify_check_given_host(&ob->hosts_verify_avoid_tls, host) != OK
765 )
766 {
767 uschar buffer2[4096];
768 if ( !smtps
769 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
770 goto SEND_FAILED;
771
772 /* If there is an I/O error, transmission of this message is deferred. If
773 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
774 false, we also defer. However, if there is a temporary rejection of STARTTLS
775 and tls_tempfail_tryclear is true, or if there is an outright rejection of
776 STARTTLS, we carry on. This means we will try to send the message in clear,
777 unless the host is in hosts_require_tls (tested below). */
778
779 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
780 ob->command_timeout))
781 {
782 if (errno != 0 || buffer2[0] == 0 ||
783 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
784 {
785 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
786 done= FALSE;
787 goto RESPONSE_FAILED;
788 }
789 }
790
791 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
792 else
793 {
794 int oldtimeout = ob->command_timeout;
795 int rc;
796
797 tls_negotiate:
798 ob->command_timeout = callout;
799 rc = tls_client_start(inblock.sock, host, addr, addr->transport
800 # ifdef EXPERIMENTAL_DANE
801 , dane ? &tlsa_dnsa : NULL
802 # endif
803 );
804 ob->command_timeout = oldtimeout;
805
806 /* TLS negotiation failed; give an error. Try in clear on a new
807 connection, if the options permit it for this host. */
808 if (rc != OK)
809 {
810 if (rc == DEFER)
811 {
812 (void)close(inblock.sock);
813 # ifdef EXPERIMENTAL_EVENT
814 (void) event_raise(addr->transport->event_action,
815 US"tcp:close", NULL);
816 # endif
817 # ifdef EXPERIMENTAL_DANE
818 if (dane)
819 {
820 if (!dane_required)
821 {
822 log_write(0, LOG_MAIN, "DANE attempt failed;"
823 " trying CA-root TLS to %s [%s] (not in hosts_require_dane)",
824 host->name, host->address);
825 dane = FALSE;
826 goto tls_negotiate;
827 }
828 }
829 else
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 tls_offered ? "an attempt to start TLS failed"
878 : "the server did not offer TLS support");
879 done= FALSE;
880 goto TLS_FAILED;
881 }
882
883 #endif /*SUPPORT_TLS*/
884
885 done = TRUE; /* so far so good; have response to HELO */
886
887 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
888
889 /* For now, transport_filter by cutthrough-delivery is not supported */
890 /* Need proper integration with the proper transport mechanism. */
891 if (cutthrough.delivery)
892 {
893 if (addr->transport->filter_command)
894 {
895 cutthrough.delivery = FALSE;
896 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
897 }
898 #ifndef DISABLE_DKIM
899 if (ob->dkim_domain)
900 {
901 cutthrough.delivery = FALSE;
902 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
903 }
904 #endif
905 }
906
907 SEND_FAILED:
908 RESPONSE_FAILED:
909 TLS_FAILED:
910 ;
911 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
912
913 /* Failure to accept HELO is cached; this blocks the whole domain for all
914 senders. I/O errors and defer responses are not cached. */
915
916 if (!done)
917 {
918 *failure_ptr = US"mail"; /* At or before MAIL */
919 if (errno == 0 && responsebuffer[0] == '5')
920 {
921 setflag(addr, af_verify_nsfail);
922 new_domain_record.result = ccache_reject;
923 }
924 }
925
926 #ifdef EXPERIMENTAL_INTERNATIONAL
927 else if ( addr->prop.utf8_msg
928 && !addr->prop.utf8_downcvt
929 && !( esmtp
930 && ( regex_UTF8
931 || ( (regex_UTF8 = regex_must_compile(
932 US"\\n250[\\s\\-]SMTPUTF8(\\s|\\n|$)", FALSE, TRUE)),
933 TRUE
934 ) )
935 && ( (utf8_offered = pcre_exec(regex_UTF8, NULL,
936 CS responsebuffer, Ustrlen(responsebuffer),
937 0, PCRE_EOPT, NULL, 0) >= 0)
938 || addr->prop.utf8_downcvt_maybe
939 ) ) )
940 {
941 HDEBUG(D_acl|D_v) debug_printf("utf8 required but not offered\n");
942 errno = ERRNO_UTF8_FWD;
943 setflag(addr, af_verify_nsfail);
944 done = FALSE;
945 }
946 else if ( addr->prop.utf8_msg
947 && (addr->prop.utf8_downcvt || !utf8_offered)
948 && (setflag(addr, af_utf8_downcvt),
949 from_address = string_address_utf8_to_alabel(from_address,
950 &addr->message),
951 addr->message
952 ) )
953 {
954 errno = ERRNO_EXPANDFAIL;
955 setflag(addr, af_verify_nsfail);
956 done = FALSE;
957 }
958 #endif
959
960 /* If we haven't authenticated, but are required to, give up. */
961 /* Try to AUTH */
962
963 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
964 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
965
966 /* Copy AUTH info for logging */
967 ( (addr->authenticator = client_authenticator),
968 (addr->auth_id = client_authenticated_id),
969
970 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
971 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
972 ) &&
973
974 ( (addr->auth_sndr = client_authenticated_sender),
975
976 /* Send the MAIL command */
977 (smtp_write_command(&outblock, FALSE,
978 #ifdef EXPERIMENTAL_INTERNATIONAL
979 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
980 ? "MAIL FROM:<%s>%s SMTPUTF8\r\n"
981 :
982 #endif
983 "MAIL FROM:<%s>%s\r\n",
984 from_address, responsebuffer) >= 0)
985 ) &&
986
987 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
988 '2', callout);
989
990 deliver_host = deliver_host_address = NULL;
991 deliver_domain = save_deliver_domain;
992
993 /* If the host does not accept MAIL FROM:<>, arrange to cache this
994 information, but again, don't record anything for an I/O error or a defer. Do
995 not cache rejections of MAIL when a non-empty sender has been used, because
996 that blocks the whole domain for all senders. */
997
998 if (!done)
999 {
1000 *failure_ptr = US"mail"; /* At or before MAIL */
1001 if (errno == 0 && responsebuffer[0] == '5')
1002 {
1003 setflag(addr, af_verify_nsfail);
1004 if (from_address[0] == 0)
1005 new_domain_record.result = ccache_reject_mfnull;
1006 }
1007 }
1008
1009 /* Otherwise, proceed to check a "random" address (if required), then the
1010 given address, and the postmaster address (if required). Between each check,
1011 issue RSET, because some servers accept only one recipient after MAIL
1012 FROM:<>.
1013
1014 Before doing this, set the result in the domain cache record to "accept",
1015 unless its previous value was ccache_reject_mfnull. In that case, the domain
1016 rejects MAIL FROM:<> and we want to continue to remember that. When that is
1017 the case, we have got here only in the case of a recipient verification with
1018 a non-null sender. */
1019
1020 else
1021 {
1022 const uschar * rcpt_domain = addr->domain;
1023
1024 #ifdef EXPERIMENTAL_INTERNATIONAL
1025 uschar * errstr = NULL;
1026 if ( testflag(addr, af_utf8_downcvt)
1027 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
1028 &errstr), errstr)
1029 )
1030 {
1031 addr->message = errstr;
1032 errno = ERRNO_EXPANDFAIL;
1033 setflag(addr, af_verify_nsfail);
1034 done = FALSE;
1035 rcpt_domain = US""; /*XXX errorhandling! */
1036 }
1037 #endif
1038
1039 new_domain_record.result =
1040 (old_domain_cache_result == ccache_reject_mfnull)?
1041 ccache_reject_mfnull: ccache_accept;
1042
1043 /* Do the random local part check first */
1044
1045 if (random_local_part != NULL)
1046 {
1047 uschar randombuffer[1024];
1048 BOOL random_ok =
1049 smtp_write_command(&outblock, FALSE,
1050 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
1051 rcpt_domain) >= 0 &&
1052 smtp_read_response(&inblock, randombuffer,
1053 sizeof(randombuffer), '2', callout);
1054
1055 /* Remember when we last did a random test */
1056
1057 new_domain_record.random_stamp = time(NULL);
1058
1059 /* If accepted, we aren't going to do any further tests below. */
1060
1061 if (random_ok)
1062 new_domain_record.random_result = ccache_accept;
1063
1064 /* Otherwise, cache a real negative response, and get back to the right
1065 state to send RCPT. Unless there's some problem such as a dropped
1066 connection, we expect to succeed, because the commands succeeded above.
1067 However, some servers drop the connection after responding to an
1068 invalid recipient, so on (any) error we drop and remake the connection.
1069 */
1070
1071 else if (errno == 0)
1072 {
1073 /* This would be ok for 1st rcpt a cutthrough, but no way to
1074 handle a subsequent. So refuse to support any */
1075 cancel_cutthrough_connection("random-recipient");
1076
1077 if (randombuffer[0] == '5')
1078 new_domain_record.random_result = ccache_reject;
1079
1080 done =
1081 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1082 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1083 '2', callout) &&
1084
1085 smtp_write_command(&outblock, FALSE,
1086 #ifdef EXPERIMENTAL_INTERNATIONAL
1087 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
1088 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
1089 :
1090 #endif
1091 "MAIL FROM:<%s>\r\n",
1092 from_address) >= 0 &&
1093 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1094 '2', callout);
1095
1096 if (!done)
1097 {
1098 HDEBUG(D_acl|D_v)
1099 debug_printf("problem after random/rset/mfrom; reopen conn\n");
1100 random_local_part = NULL;
1101 #ifdef SUPPORT_TLS
1102 tls_close(FALSE, TRUE);
1103 #endif
1104 (void)close(inblock.sock);
1105 #ifdef EXPERIMENTAL_EVENT
1106 (void) event_raise(addr->transport->event_action,
1107 US"tcp:close", NULL);
1108 #endif
1109 goto tls_retry_connection;
1110 }
1111 }
1112 else done = FALSE; /* Some timeout/connection problem */
1113 } /* Random check */
1114
1115 /* If the host is accepting all local parts, as determined by the "random"
1116 check, we don't need to waste time doing any further checking. */
1117
1118 if (new_domain_record.random_result != ccache_accept && done)
1119 {
1120 /* Get the rcpt_include_affixes flag from the transport if there is one,
1121 but assume FALSE if there is not. */
1122
1123 uschar * rcpt = transport_rcpt_address(addr,
1124 addr->transport ? addr->transport->rcpt_include_affixes : FALSE);
1125
1126 #ifdef EXPERIMENTAL_INTERNATIONAL
1127 /*XXX should the conversion be moved into transport_rcpt_address() ? */
1128 uschar * dummy_errstr = NULL;
1129 if ( testflag(addr, af_utf8_downcvt)
1130 && (rcpt = string_address_utf8_to_alabel(rcpt, &dummy_errstr),
1131 dummy_errstr
1132 ) )
1133 {
1134 errno = ERRNO_EXPANDFAIL;
1135 *failure_ptr = US"recipient";
1136 done = FALSE;
1137 }
1138 else
1139 #endif
1140
1141 done =
1142 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
1143 rcpt) >= 0 &&
1144 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1145 '2', callout);
1146
1147 if (done)
1148 new_address_record.result = ccache_accept;
1149 else if (errno == 0 && responsebuffer[0] == '5')
1150 {
1151 *failure_ptr = US"recipient";
1152 new_address_record.result = ccache_reject;
1153 }
1154
1155 /* Do postmaster check if requested; if a full check is required, we
1156 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
1157
1158 if (done && pm_mailfrom != NULL)
1159 {
1160 /* Could possibly shift before main verify, just above, and be ok
1161 for cutthrough. But no way to handle a subsequent rcpt, so just
1162 refuse any */
1163 cancel_cutthrough_connection("postmaster verify");
1164 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
1165
1166 done =
1167 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1168 smtp_read_response(&inblock, responsebuffer,
1169 sizeof(responsebuffer), '2', callout) &&
1170
1171 smtp_write_command(&outblock, FALSE,
1172 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
1173 smtp_read_response(&inblock, responsebuffer,
1174 sizeof(responsebuffer), '2', callout) &&
1175
1176 /* First try using the current domain */
1177
1178 ((
1179 smtp_write_command(&outblock, FALSE,
1180 "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 &&
1181 smtp_read_response(&inblock, responsebuffer,
1182 sizeof(responsebuffer), '2', callout)
1183 )
1184
1185 ||
1186
1187 /* If that doesn't work, and a full check is requested,
1188 try without the domain. */
1189
1190 (
1191 (options & vopt_callout_fullpm) != 0 &&
1192 smtp_write_command(&outblock, FALSE,
1193 "RCPT TO:<postmaster>\r\n") >= 0 &&
1194 smtp_read_response(&inblock, responsebuffer,
1195 sizeof(responsebuffer), '2', callout)
1196 ));
1197
1198 /* Sort out the cache record */
1199
1200 new_domain_record.postmaster_stamp = time(NULL);
1201
1202 if (done)
1203 new_domain_record.postmaster_result = ccache_accept;
1204 else if (errno == 0 && responsebuffer[0] == '5')
1205 {
1206 *failure_ptr = US"postmaster";
1207 setflag(addr, af_verify_pmfail);
1208 new_domain_record.postmaster_result = ccache_reject;
1209 }
1210 }
1211 } /* Random not accepted */
1212 } /* MAIL FROM: accepted */
1213
1214 /* For any failure of the main check, other than a negative response, we just
1215 close the connection and carry on. We can identify a negative response by the
1216 fact that errno is zero. For I/O errors it will be non-zero
1217
1218 Set up different error texts for logging and for sending back to the caller
1219 as an SMTP response. Log in all cases, using a one-line format. For sender
1220 callouts, give a full response to the caller, but for recipient callouts,
1221 don't give the IP address because this may be an internal host whose identity
1222 is not to be widely broadcast. */
1223
1224 if (!done)
1225 {
1226 if (errno == ETIMEDOUT)
1227 {
1228 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1229 send_quit = FALSE;
1230 }
1231 #ifdef EXPERIMENTAL_INTERNATIONAL
1232 else if (errno == ERRNO_UTF8_FWD)
1233 {
1234 extern int acl_where; /* src/acl.c */
1235 errno = 0;
1236 addr->message = string_sprintf(
1237 "response to \"%s\" from %s [%s] did not include SMTPUTF8",
1238 big_buffer, host->name, host->address);
1239 addr->user_message = acl_where == ACL_WHERE_RCPT
1240 ? US"533 mailbox name not allowed"
1241 : US"550 mailbox unavailable";
1242 yield = FAIL;
1243 done = TRUE;
1244 }
1245 #endif
1246 else if (errno == 0)
1247 {
1248 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1249
1250 addr->message =
1251 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1252 big_buffer, host->name, host->address,
1253 string_printing(responsebuffer));
1254
1255 addr->user_message = is_recipient?
1256 string_sprintf("Callout verification failed:\n%s", responsebuffer)
1257 :
1258 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1259 host->address, big_buffer, responsebuffer);
1260
1261 /* Hard rejection ends the process */
1262
1263 if (responsebuffer[0] == '5') /* Address rejected */
1264 {
1265 yield = FAIL;
1266 done = TRUE;
1267 }
1268 }
1269 }
1270
1271 /* End the SMTP conversation and close the connection. */
1272
1273 /* Cutthrough - on a successfull connect and recipient-verify with
1274 use-sender and we are 1st rcpt and have no cutthrough conn so far
1275 here is where we want to leave the conn open */
1276 if ( cutthrough.delivery
1277 && rcpt_count == 1
1278 && done
1279 && yield == OK
1280 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
1281 && !random_local_part
1282 && !pm_mailfrom
1283 && cutthrough.fd < 0
1284 && !lmtp
1285 )
1286 {
1287 cutthrough.fd = outblock.sock; /* We assume no buffer in use in the outblock */
1288 cutthrough.nrcpt = 1;
1289 cutthrough.interface = interface;
1290 cutthrough.host = *host;
1291 cutthrough.addr = *addr; /* Save the address_item for later logging */
1292 cutthrough.addr.next = NULL;
1293 cutthrough.addr.host_used = &cutthrough.host;
1294 if (addr->parent)
1295 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1296 *addr->parent;
1297 ctblock.buffer = ctbuffer;
1298 ctblock.buffersize = sizeof(ctbuffer);
1299 ctblock.ptr = ctbuffer;
1300 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1301 ctblock.sock = cutthrough.fd;
1302 }
1303 else
1304 {
1305 /* Ensure no cutthrough on multiple address verifies */
1306 if (options & vopt_callout_recipsender)
1307 cancel_cutthrough_connection("multiple verify calls");
1308 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1309
1310 #ifdef SUPPORT_TLS
1311 tls_close(FALSE, TRUE);
1312 #endif
1313 (void)close(inblock.sock);
1314 #ifdef EXPERIMENTAL_EVENT
1315 (void) event_raise(addr->transport->event_action,
1316 US"tcp:close", NULL);
1317 #endif
1318 }
1319
1320 } /* Loop through all hosts, while !done */
1321 }
1322
1323 /* If we get here with done == TRUE, a successful callout happened, and yield
1324 will be set OK or FAIL according to the response to the RCPT command.
1325 Otherwise, we looped through the hosts but couldn't complete the business.
1326 However, there may be domain-specific information to cache in both cases.
1327
1328 The value of the result field in the new_domain record is ccache_unknown if
1329 there was an error before or with MAIL FROM:, and errno was not zero,
1330 implying some kind of I/O error. We don't want to write the cache in that case.
1331 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1332
1333 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1334 {
1335 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1336 == NULL)
1337 {
1338 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1339 }
1340 else
1341 {
1342 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1343 (int)sizeof(dbdata_callout_cache));
1344 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1345 " result=%d postmaster=%d random=%d\n",
1346 new_domain_record.result,
1347 new_domain_record.postmaster_result,
1348 new_domain_record.random_result);
1349 }
1350 }
1351
1352 /* If a definite result was obtained for the callout, cache it unless caching
1353 is disabled. */
1354
1355 if (done)
1356 {
1357 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1358 {
1359 if (dbm_file == NULL)
1360 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1361 if (dbm_file == NULL)
1362 {
1363 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1364 }
1365 else
1366 {
1367 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1368 (int)sizeof(dbdata_callout_cache_address));
1369 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1370 (new_address_record.result == ccache_accept)? "positive" : "negative");
1371 }
1372 }
1373 } /* done */
1374
1375 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1376 temporary error. If there was only one host, and a response was received, leave
1377 it alone if supplying details. Otherwise, give a generic response. */
1378
1379 else /* !done */
1380 {
1381 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1382 is_recipient? "recipient" : "sender");
1383 yield = DEFER;
1384
1385 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1386
1387 addr->user_message = (!smtp_return_error_details)? dullmsg :
1388 string_sprintf("%s for <%s>.\n"
1389 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1390 "they may be permanently unreachable from this server. In the latter case,\n%s",
1391 dullmsg, addr->address,
1392 is_recipient?
1393 "the address will never be accepted."
1394 :
1395 "you need to change the address or create an MX record for its domain\n"
1396 "if it is supposed to be generally accessible from the Internet.\n"
1397 "Talk to your mail administrator for details.");
1398
1399 /* Force a specific error code */
1400
1401 addr->basic_errno = ERRNO_CALLOUTDEFER;
1402 }
1403
1404 /* Come here from within the cache-reading code on fast-track exit. */
1405
1406 END_CALLOUT:
1407 if (dbm_file != NULL) dbfn_close(dbm_file);
1408 return yield;
1409 }
1410
1411
1412
1413 /* Called after recipient-acl to get a cutthrough connection open when
1414 one was requested and a recipient-verify wasn't subsequently done.
1415 */
1416 void
1417 open_cutthrough_connection( address_item * addr )
1418 {
1419 address_item addr2;
1420
1421 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1422 /* We must use a copy of the address for verification, because it might
1423 get rewritten. */
1424
1425 addr2 = *addr;
1426 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1427 rcpt_count > 1 ? "more" : "start");
1428 (void) verify_address(&addr2, NULL,
1429 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1430 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1431 NULL, NULL, NULL);
1432 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1433 return;
1434 }
1435
1436
1437
1438 /* Send given number of bytes from the buffer */
1439 static BOOL
1440 cutthrough_send(int n)
1441 {
1442 if(cutthrough.fd < 0)
1443 return TRUE;
1444
1445 if(
1446 #ifdef SUPPORT_TLS
1447 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1448 #endif
1449 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1450 )
1451 {
1452 transport_count += n;
1453 ctblock.ptr= ctblock.buffer;
1454 return TRUE;
1455 }
1456
1457 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1458 return FALSE;
1459 }
1460
1461
1462
1463 static BOOL
1464 _cutthrough_puts(uschar * cp, int n)
1465 {
1466 while(n--)
1467 {
1468 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1469 if(!cutthrough_send(ctblock.buffersize))
1470 return FALSE;
1471
1472 *ctblock.ptr++ = *cp++;
1473 }
1474 return TRUE;
1475 }
1476
1477 /* Buffered output of counted data block. Return boolean success */
1478 BOOL
1479 cutthrough_puts(uschar * cp, int n)
1480 {
1481 if (cutthrough.fd < 0) return TRUE;
1482 if (_cutthrough_puts(cp, n)) return TRUE;
1483 cancel_cutthrough_connection("transmit failed");
1484 return FALSE;
1485 }
1486
1487
1488 static BOOL
1489 _cutthrough_flush_send(void)
1490 {
1491 int n= ctblock.ptr-ctblock.buffer;
1492
1493 if(n>0)
1494 if(!cutthrough_send(n))
1495 return FALSE;
1496 return TRUE;
1497 }
1498
1499
1500 /* Send out any bufferred output. Return boolean success. */
1501 BOOL
1502 cutthrough_flush_send(void)
1503 {
1504 if (_cutthrough_flush_send()) return TRUE;
1505 cancel_cutthrough_connection("transmit failed");
1506 return FALSE;
1507 }
1508
1509
1510 BOOL
1511 cutthrough_put_nl(void)
1512 {
1513 return cutthrough_puts(US"\r\n", 2);
1514 }
1515
1516
1517 /* Get and check response from cutthrough target */
1518 static uschar
1519 cutthrough_response(char expect, uschar ** copy)
1520 {
1521 smtp_inblock inblock;
1522 uschar inbuffer[4096];
1523 uschar responsebuffer[4096];
1524
1525 inblock.buffer = inbuffer;
1526 inblock.buffersize = sizeof(inbuffer);
1527 inblock.ptr = inbuffer;
1528 inblock.ptrend = inbuffer;
1529 inblock.sock = cutthrough.fd;
1530 /* this relies on (inblock.sock == tls_out.active) */
1531 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1532 cancel_cutthrough_connection("target timeout on read");
1533
1534 if(copy != NULL)
1535 {
1536 uschar * cp;
1537 *copy = cp = string_copy(responsebuffer);
1538 /* Trim the trailing end of line */
1539 cp += Ustrlen(responsebuffer);
1540 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1541 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1542 }
1543
1544 return responsebuffer[0];
1545 }
1546
1547
1548 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1549 BOOL
1550 cutthrough_predata(void)
1551 {
1552 if(cutthrough.fd < 0)
1553 return FALSE;
1554
1555 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1556 cutthrough_puts(US"DATA\r\n", 6);
1557 cutthrough_flush_send();
1558
1559 /* Assume nothing buffered. If it was it gets ignored. */
1560 return cutthrough_response('3', NULL) == '3';
1561 }
1562
1563
1564 /* fd and use_crlf args only to match write_chunk() */
1565 static BOOL
1566 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1567 {
1568 uschar * s2;
1569 while(s && (s2 = Ustrchr(s, '\n')))
1570 {
1571 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1572 return FALSE;
1573 s = s2+1;
1574 }
1575 return TRUE;
1576 }
1577
1578
1579 /* Buffered send of headers. Return success boolean. */
1580 /* Expands newlines to wire format (CR,NL). */
1581 /* Also sends header-terminating blank line. */
1582 BOOL
1583 cutthrough_headers_send(void)
1584 {
1585 if(cutthrough.fd < 0)
1586 return FALSE;
1587
1588 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1589 but having a separate buffered-output function (for now)
1590 */
1591 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1592
1593 if (!transport_headers_send(&cutthrough.addr, cutthrough.fd,
1594 cutthrough.addr.transport->add_headers,
1595 cutthrough.addr.transport->remove_headers,
1596 &cutthrough_write_chunk, TRUE,
1597 cutthrough.addr.transport->rewrite_rules,
1598 cutthrough.addr.transport->rewrite_existflags))
1599 return FALSE;
1600
1601 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1602 return TRUE;
1603 }
1604
1605
1606 static void
1607 close_cutthrough_connection(const char * why)
1608 {
1609 if(cutthrough.fd >= 0)
1610 {
1611 /* We could be sending this after a bunch of data, but that is ok as
1612 the only way to cancel the transfer in dataphase is to drop the tcp
1613 conn before the final dot.
1614 */
1615 ctblock.ptr = ctbuffer;
1616 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1617 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1618 _cutthrough_flush_send();
1619 /* No wait for response */
1620
1621 #ifdef SUPPORT_TLS
1622 tls_close(FALSE, TRUE);
1623 #endif
1624 (void)close(cutthrough.fd);
1625 cutthrough.fd = -1;
1626 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1627 }
1628 ctblock.ptr = ctbuffer;
1629 }
1630
1631 void
1632 cancel_cutthrough_connection(const char * why)
1633 {
1634 close_cutthrough_connection(why);
1635 cutthrough.delivery = FALSE;
1636 }
1637
1638
1639
1640
1641 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1642 Log an OK response as a transmission.
1643 Close the connection.
1644 Return smtp response-class digit.
1645 */
1646 uschar *
1647 cutthrough_finaldot(void)
1648 {
1649 uschar res;
1650 address_item * addr;
1651 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1652
1653 /* Assume data finshed with new-line */
1654 if( !cutthrough_puts(US".", 1)
1655 || !cutthrough_put_nl()
1656 || !cutthrough_flush_send()
1657 )
1658 return cutthrough.addr.message;
1659
1660 res = cutthrough_response('2', &cutthrough.addr.message);
1661 for (addr = &cutthrough.addr; addr; addr = addr->next)
1662 {
1663 addr->message = cutthrough.addr.message;
1664 switch(res)
1665 {
1666 case '2':
1667 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1668 close_cutthrough_connection("delivered");
1669 break;
1670
1671 case '4':
1672 delivery_log(LOG_MAIN, addr, 0,
1673 US"tmp-reject from cutthrough after DATA:");
1674 break;
1675
1676 case '5':
1677 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1678 US"rejected after DATA:");
1679 break;
1680
1681 default:
1682 break;
1683 }
1684 }
1685 return cutthrough.addr.message;
1686 }
1687
1688
1689
1690 /*************************************************
1691 * Copy error to toplevel address *
1692 *************************************************/
1693
1694 /* This function is used when a verify fails or defers, to ensure that the
1695 failure or defer information is in the original toplevel address. This applies
1696 when an address is redirected to a single new address, and the failure or
1697 deferral happens to the child address.
1698
1699 Arguments:
1700 vaddr the verify address item
1701 addr the final address item
1702 yield FAIL or DEFER
1703
1704 Returns: the value of YIELD
1705 */
1706
1707 static int
1708 copy_error(address_item *vaddr, address_item *addr, int yield)
1709 {
1710 if (addr != vaddr)
1711 {
1712 vaddr->message = addr->message;
1713 vaddr->user_message = addr->user_message;
1714 vaddr->basic_errno = addr->basic_errno;
1715 vaddr->more_errno = addr->more_errno;
1716 vaddr->prop.address_data = addr->prop.address_data;
1717 copyflag(vaddr, addr, af_pass_message);
1718 }
1719 return yield;
1720 }
1721
1722
1723
1724
1725 /**************************************************
1726 * printf that automatically handles TLS if needed *
1727 ***************************************************/
1728
1729 /* This function is used by verify_address() as a substitute for all fprintf()
1730 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1731 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1732 that assumes that we always use the smtp_out FILE* when not using TLS or the
1733 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1734 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1735 fprintf().
1736
1737 Arguments:
1738 f the candidate FILE* to write to
1739 format format string
1740 ... optional arguments
1741
1742 Returns:
1743 nothing
1744 */
1745
1746 static void PRINTF_FUNCTION(2,3)
1747 respond_printf(FILE *f, const char *format, ...)
1748 {
1749 va_list ap;
1750
1751 va_start(ap, format);
1752 if (smtp_out && (f == smtp_out))
1753 smtp_vprintf(format, ap);
1754 else
1755 vfprintf(f, format, ap);
1756 va_end(ap);
1757 }
1758
1759
1760
1761 /*************************************************
1762 * Verify an email address *
1763 *************************************************/
1764
1765 /* This function is used both for verification (-bv and at other times) and
1766 address testing (-bt), which is indicated by address_test_mode being set.
1767
1768 Arguments:
1769 vaddr contains the address to verify; the next field in this block
1770 must be NULL
1771 f if not NULL, write the result to this file
1772 options various option bits:
1773 vopt_fake_sender => this sender verify is not for the real
1774 sender (it was verify=sender=xxxx or an address from a
1775 header line) - rewriting must not change sender_address
1776 vopt_is_recipient => this is a recipient address, otherwise
1777 it's a sender address - this affects qualification and
1778 rewriting and messages from callouts
1779 vopt_qualify => qualify an unqualified address; else error
1780 vopt_expn => called from SMTP EXPN command
1781 vopt_success_on_redirect => when a new address is generated
1782 the verification instantly succeeds
1783
1784 These ones are used by do_callout() -- the options variable
1785 is passed to it.
1786
1787 vopt_callout_fullpm => if postmaster check, do full one
1788 vopt_callout_no_cache => don't use callout cache
1789 vopt_callout_random => do the "random" thing
1790 vopt_callout_recipsender => use real sender for recipient
1791 vopt_callout_recippmaster => use postmaster for recipient
1792
1793 callout if > 0, specifies that callout is required, and gives timeout
1794 for individual commands
1795 callout_overall if > 0, gives overall timeout for the callout function;
1796 if < 0, a default is used (see do_callout())
1797 callout_connect the connection timeout for callouts
1798 se_mailfrom when callout is requested to verify a sender, use this
1799 in MAIL FROM; NULL => ""
1800 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1801 thing and use this as the sender address (may be "")
1802
1803 routed if not NULL, set TRUE if routing succeeded, so we can
1804 distinguish between routing failed and callout failed
1805
1806 Returns: OK address verified
1807 FAIL address failed to verify
1808 DEFER can't tell at present
1809 */
1810
1811 int
1812 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1813 int callout_overall, int callout_connect, uschar *se_mailfrom,
1814 uschar *pm_mailfrom, BOOL *routed)
1815 {
1816 BOOL allok = TRUE;
1817 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1818 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1819 BOOL expn = (options & vopt_expn) != 0;
1820 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1821 int i;
1822 int yield = OK;
1823 int verify_type = expn? v_expn :
1824 address_test_mode? v_none :
1825 is_recipient? v_recipient : v_sender;
1826 address_item *addr_list;
1827 address_item *addr_new = NULL;
1828 address_item *addr_remote = NULL;
1829 address_item *addr_local = NULL;
1830 address_item *addr_succeed = NULL;
1831 uschar **failure_ptr = is_recipient?
1832 &recipient_verify_failure : &sender_verify_failure;
1833 uschar *ko_prefix, *cr;
1834 uschar *address = vaddr->address;
1835 uschar *save_sender;
1836 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1837
1838 /* Clear, just in case */
1839
1840 *failure_ptr = NULL;
1841
1842 /* Set up a prefix and suffix for error message which allow us to use the same
1843 output statements both in EXPN mode (where an SMTP response is needed) and when
1844 debugging with an output file. */
1845
1846 if (expn)
1847 {
1848 ko_prefix = US"553 ";
1849 cr = US"\r";
1850 }
1851 else ko_prefix = cr = US"";
1852
1853 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1854
1855 if (parse_find_at(address) == NULL)
1856 {
1857 if ((options & vopt_qualify) == 0)
1858 {
1859 if (f != NULL)
1860 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1861 ko_prefix, address, cr);
1862 *failure_ptr = US"qualify";
1863 return FAIL;
1864 }
1865 address = rewrite_address_qualify(address, is_recipient);
1866 }
1867
1868 DEBUG(D_verify)
1869 {
1870 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1871 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1872 }
1873
1874 /* Rewrite and report on it. Clear the domain and local part caches - these
1875 may have been set by domains and local part tests during an ACL. */
1876
1877 if (global_rewrite_rules != NULL)
1878 {
1879 uschar *old = address;
1880 address = rewrite_address(address, is_recipient, FALSE,
1881 global_rewrite_rules, rewrite_existflags);
1882 if (address != old)
1883 {
1884 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1885 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1886 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1887 }
1888 }
1889
1890 /* If this is the real sender address, we must update sender_address at
1891 this point, because it may be referred to in the routers. */
1892
1893 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1894 sender_address = address;
1895
1896 /* If the address was rewritten to <> no verification can be done, and we have
1897 to return OK. This rewriting is permitted only for sender addresses; for other
1898 addresses, such rewriting fails. */
1899
1900 if (address[0] == 0) return OK;
1901
1902 /* Flip the legacy TLS-related variables over to the outbound set in case
1903 they're used in the context of a transport used by verification. Reset them
1904 at exit from this routine. */
1905
1906 tls_modify_variables(&tls_out);
1907
1908 /* Save a copy of the sender address for re-instating if we change it to <>
1909 while verifying a sender address (a nice bit of self-reference there). */
1910
1911 save_sender = sender_address;
1912
1913 /* Update the address structure with the possibly qualified and rewritten
1914 address. Set it up as the starting address on the chain of new addresses. */
1915
1916 vaddr->address = address;
1917 addr_new = vaddr;
1918
1919 /* We need a loop, because an address can generate new addresses. We must also
1920 cope with generated pipes and files at the top level. (See also the code and
1921 comment in deliver.c.) However, it is usually the case that the router for
1922 user's .forward files has its verify flag turned off.
1923
1924 If an address generates more than one child, the loop is used only when
1925 full_info is set, and this can only be set locally. Remote enquiries just get
1926 information about the top level address, not anything that it generated. */
1927
1928 while (addr_new != NULL)
1929 {
1930 int rc;
1931 address_item *addr = addr_new;
1932
1933 addr_new = addr->next;
1934 addr->next = NULL;
1935
1936 DEBUG(D_verify)
1937 {
1938 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1939 debug_printf("Considering %s\n", addr->address);
1940 }
1941
1942 /* Handle generated pipe, file or reply addresses. We don't get these
1943 when handling EXPN, as it does only one level of expansion. */
1944
1945 if (testflag(addr, af_pfr))
1946 {
1947 allok = FALSE;
1948 if (f != NULL)
1949 {
1950 BOOL allow;
1951
1952 if (addr->address[0] == '>')
1953 {
1954 allow = testflag(addr, af_allow_reply);
1955 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1956 }
1957 else
1958 {
1959 allow = (addr->address[0] == '|')?
1960 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1961 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1962 }
1963
1964 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1965 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1966 "%s\n", addr->message);
1967 else if (allow)
1968 fprintf(f, "\n transport = %s\n", addr->transport->name);
1969 else
1970 fprintf(f, " *** forbidden ***\n");
1971 }
1972 continue;
1973 }
1974
1975 /* Just in case some router parameter refers to it. */
1976
1977 return_path = (addr->prop.errors_address != NULL)?
1978 addr->prop.errors_address : sender_address;
1979
1980 /* Split the address into domain and local part, handling the %-hack if
1981 necessary, and then route it. While routing a sender address, set
1982 $sender_address to <> because that is what it will be if we were trying to
1983 send a bounce to the sender. */
1984
1985 if (routed != NULL) *routed = FALSE;
1986 if ((rc = deliver_split_address(addr)) == OK)
1987 {
1988 if (!is_recipient) sender_address = null_sender;
1989 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1990 &addr_succeed, verify_type);
1991 sender_address = save_sender; /* Put back the real sender */
1992 }
1993
1994 /* If routing an address succeeded, set the flag that remembers, for use when
1995 an ACL cached a sender verify (in case a callout fails). Then if routing set
1996 up a list of hosts or the transport has a host list, and the callout option
1997 is set, and we aren't in a host checking run, do the callout verification,
1998 and set another flag that notes that a callout happened. */
1999
2000 if (rc == OK)
2001 {
2002 if (routed != NULL) *routed = TRUE;
2003 if (callout > 0)
2004 {
2005 host_item *host_list = addr->host_list;
2006
2007 /* Make up some data for use in the case where there is no remote
2008 transport. */
2009
2010 transport_feedback tf = {
2011 NULL, /* interface (=> any) */
2012 US"smtp", /* port */
2013 US"smtp", /* protocol */
2014 NULL, /* hosts */
2015 US"$smtp_active_hostname", /* helo_data */
2016 FALSE, /* hosts_override */
2017 FALSE, /* hosts_randomize */
2018 FALSE, /* gethostbyname */
2019 TRUE, /* qualify_single */
2020 FALSE /* search_parents */
2021 };
2022
2023 /* If verification yielded a remote transport, we want to use that
2024 transport's options, so as to mimic what would happen if we were really
2025 sending a message to this address. */
2026
2027 if (addr->transport != NULL && !addr->transport->info->local)
2028 {
2029 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
2030
2031 /* If the transport has hosts and the router does not, or if the
2032 transport is configured to override the router's hosts, we must build a
2033 host list of the transport's hosts, and find the IP addresses */
2034
2035 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
2036 {
2037 uschar *s;
2038 const uschar *save_deliver_domain = deliver_domain;
2039 uschar *save_deliver_localpart = deliver_localpart;
2040
2041 host_list = NULL; /* Ignore the router's hosts */
2042
2043 deliver_domain = addr->domain;
2044 deliver_localpart = addr->local_part;
2045 s = expand_string(tf.hosts);
2046 deliver_domain = save_deliver_domain;
2047 deliver_localpart = save_deliver_localpart;
2048
2049 if (s == NULL)
2050 {
2051 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
2052 "\"%s\" in %s transport for callout: %s", tf.hosts,
2053 addr->transport->name, expand_string_message);
2054 }
2055 else
2056 {
2057 int flags;
2058 host_item *host, *nexthost;
2059 host_build_hostlist(&host_list, s, tf.hosts_randomize);
2060
2061 /* Just ignore failures to find a host address. If we don't manage
2062 to find any addresses, the callout will defer. Note that more than
2063 one address may be found for a single host, which will result in
2064 additional host items being inserted into the chain. Hence we must
2065 save the next host first. */
2066
2067 flags = HOST_FIND_BY_A;
2068 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2069 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2070
2071 for (host = host_list; host != NULL; host = nexthost)
2072 {
2073 nexthost = host->next;
2074 if (tf.gethostbyname ||
2075 string_is_ip_address(host->name, NULL) != 0)
2076 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
2077 else
2078 {
2079 dnssec_domains * dnssec_domains = NULL;
2080 if (Ustrcmp(addr->transport->driver_name, "smtp") == 0)
2081 {
2082 smtp_transport_options_block * ob =
2083 (smtp_transport_options_block *)
2084 addr->transport->options_block;
2085 dnssec_domains = &ob->dnssec;
2086 }
2087
2088 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2089 dnssec_domains, NULL, NULL);
2090 }
2091 }
2092 }
2093 }
2094 }
2095
2096 /* Can only do a callout if we have at least one host! If the callout
2097 fails, it will have set ${sender,recipient}_verify_failure. */
2098
2099 if (host_list != NULL)
2100 {
2101 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
2102 if (host_checking && !host_checking_callout)
2103 {
2104 HDEBUG(D_verify)
2105 debug_printf("... callout omitted by default when host testing\n"
2106 "(Use -bhc if you want the callouts to happen.)\n");
2107 }
2108 else
2109 {
2110 #ifdef SUPPORT_TLS
2111 deliver_set_expansions(addr);
2112 #endif
2113 verify_mode = is_recipient ? US"R" : US"S";
2114 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
2115 callout_connect, options, se_mailfrom, pm_mailfrom);
2116 verify_mode = NULL;
2117 }
2118 }
2119 else
2120 {
2121 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
2122 "transport provided a host list\n");
2123 }
2124 }
2125 }
2126
2127 /* Otherwise, any failure is a routing failure */
2128
2129 else *failure_ptr = US"route";
2130
2131 /* A router may return REROUTED if it has set up a child address as a result
2132 of a change of domain name (typically from widening). In this case we always
2133 want to continue to verify the new child. */
2134
2135 if (rc == REROUTED) continue;
2136
2137 /* Handle hard failures */
2138
2139 if (rc == FAIL)
2140 {
2141 allok = FALSE;
2142 if (f != NULL)
2143 {
2144 address_item *p = addr->parent;
2145
2146 respond_printf(f, "%s%s %s", ko_prefix,
2147 full_info? addr->address : address,
2148 address_test_mode? "is undeliverable" : "failed to verify");
2149 if (!expn && admin_user)
2150 {
2151 if (addr->basic_errno > 0)
2152 respond_printf(f, ": %s", strerror(addr->basic_errno));
2153 if (addr->message != NULL)
2154 respond_printf(f, ": %s", addr->message);
2155 }
2156
2157 /* Show parents iff doing full info */
2158
2159 if (full_info) while (p != NULL)
2160 {
2161 respond_printf(f, "%s\n <-- %s", cr, p->address);
2162 p = p->parent;
2163 }
2164 respond_printf(f, "%s\n", cr);
2165 }
2166 cancel_cutthrough_connection("routing hard fail");
2167
2168 if (!full_info)
2169 {
2170 yield = copy_error(vaddr, addr, FAIL);
2171 goto out;
2172 }
2173 else yield = FAIL;
2174 }
2175
2176 /* Soft failure */
2177
2178 else if (rc == DEFER)
2179 {
2180 allok = FALSE;
2181 if (f != NULL)
2182 {
2183 address_item *p = addr->parent;
2184 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
2185 full_info? addr->address : address);
2186 if (!expn && admin_user)
2187 {
2188 if (addr->basic_errno > 0)
2189 respond_printf(f, ": %s", strerror(addr->basic_errno));
2190 if (addr->message != NULL)
2191 respond_printf(f, ": %s", addr->message);
2192 else if (addr->basic_errno <= 0)
2193 respond_printf(f, ": unknown error");
2194 }
2195
2196 /* Show parents iff doing full info */
2197
2198 if (full_info) while (p != NULL)
2199 {
2200 respond_printf(f, "%s\n <-- %s", cr, p->address);
2201 p = p->parent;
2202 }
2203 respond_printf(f, "%s\n", cr);
2204 }
2205 cancel_cutthrough_connection("routing soft fail");
2206
2207 if (!full_info)
2208 {
2209 yield = copy_error(vaddr, addr, DEFER);
2210 goto out;
2211 }
2212 else if (yield == OK) yield = DEFER;
2213 }
2214
2215 /* If we are handling EXPN, we do not want to continue to route beyond
2216 the top level (whose address is in "address"). */
2217
2218 else if (expn)
2219 {
2220 uschar *ok_prefix = US"250-";
2221 if (addr_new == NULL)
2222 {
2223 if (addr_local == NULL && addr_remote == NULL)
2224 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2225 else
2226 respond_printf(f, "250 <%s>\r\n", address);
2227 }
2228 else while (addr_new != NULL)
2229 {
2230 address_item *addr2 = addr_new;
2231 addr_new = addr2->next;
2232 if (addr_new == NULL) ok_prefix = US"250 ";
2233 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2234 }
2235 yield = OK;
2236 goto out;
2237 }
2238
2239 /* Successful routing other than EXPN. */
2240
2241 else
2242 {
2243 /* Handle successful routing when short info wanted. Otherwise continue for
2244 other (generated) addresses. Short info is the operational case. Full info
2245 can be requested only when debug_selector != 0 and a file is supplied.
2246
2247 There is a conflict between the use of aliasing as an alternate email
2248 address, and as a sort of mailing list. If an alias turns the incoming
2249 address into just one address (e.g. J.Caesar->jc44) you may well want to
2250 carry on verifying the generated address to ensure it is valid when
2251 checking incoming mail. If aliasing generates multiple addresses, you
2252 probably don't want to do this. Exim therefore treats the generation of
2253 just a single new address as a special case, and continues on to verify the
2254 generated address. */
2255
2256 if (!full_info && /* Stop if short info wanted AND */
2257 (((addr_new == NULL || /* No new address OR */
2258 addr_new->next != NULL || /* More than one new address OR */
2259 testflag(addr_new, af_pfr))) /* New address is pfr */
2260 || /* OR */
2261 (addr_new != NULL && /* At least one new address AND */
2262 success_on_redirect))) /* success_on_redirect is set */
2263 {
2264 if (f != NULL) fprintf(f, "%s %s\n", address,
2265 address_test_mode? "is deliverable" : "verified");
2266
2267 /* If we have carried on to verify a child address, we want the value
2268 of $address_data to be that of the child */
2269
2270 vaddr->prop.address_data = addr->prop.address_data;
2271 yield = OK;
2272 goto out;
2273 }
2274 }
2275 } /* Loop for generated addresses */
2276
2277 /* Display the full results of the successful routing, including any generated
2278 addresses. Control gets here only when full_info is set, which requires f not
2279 to be NULL, and this occurs only when a top-level verify is called with the
2280 debugging switch on.
2281
2282 If there are no local and no remote addresses, and there were no pipes, files,
2283 or autoreplies, and there were no errors or deferments, the message is to be
2284 discarded, usually because of the use of :blackhole: in an alias file. */
2285
2286 if (allok && addr_local == NULL && addr_remote == NULL)
2287 {
2288 fprintf(f, "mail to %s is discarded\n", address);
2289 goto out;
2290 }
2291
2292 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2293 {
2294 while (addr_list != NULL)
2295 {
2296 address_item *addr = addr_list;
2297 address_item *p = addr->parent;
2298 addr_list = addr->next;
2299
2300 fprintf(f, "%s", CS addr->address);
2301 #ifdef EXPERIMENTAL_SRS
2302 if(addr->prop.srs_sender)
2303 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2304 #endif
2305
2306 /* If the address is a duplicate, show something about it. */
2307
2308 if (!testflag(addr, af_pfr))
2309 {
2310 tree_node *tnode;
2311 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
2312 fprintf(f, " [duplicate, would not be delivered]");
2313 else tree_add_duplicate(addr->unique, addr);
2314 }
2315
2316 /* Now show its parents */
2317
2318 while (p != NULL)
2319 {
2320 fprintf(f, "\n <-- %s", p->address);
2321 p = p->parent;
2322 }
2323 fprintf(f, "\n ");
2324
2325 /* Show router, and transport */
2326
2327 fprintf(f, "router = %s, ", addr->router->name);
2328 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
2329 addr->transport->name);
2330
2331 /* Show any hosts that are set up by a router unless the transport
2332 is going to override them; fiddle a bit to get a nice format. */
2333
2334 if (addr->host_list != NULL && addr->transport != NULL &&
2335 !addr->transport->overrides_hosts)
2336 {
2337 host_item *h;
2338 int maxlen = 0;
2339 int maxaddlen = 0;
2340 for (h = addr->host_list; h != NULL; h = h->next)
2341 {
2342 int len = Ustrlen(h->name);
2343 if (len > maxlen) maxlen = len;
2344 len = (h->address != NULL)? Ustrlen(h->address) : 7;
2345 if (len > maxaddlen) maxaddlen = len;
2346 }
2347 for (h = addr->host_list; h != NULL; h = h->next)
2348 {
2349 int len = Ustrlen(h->name);
2350 fprintf(f, " host %s ", h->name);
2351 while (len++ < maxlen) fprintf(f, " ");
2352 if (h->address != NULL)
2353 {
2354 fprintf(f, "[%s] ", h->address);
2355 len = Ustrlen(h->address);
2356 }
2357 else if (!addr->transport->info->local) /* Omit [unknown] for local */
2358 {
2359 fprintf(f, "[unknown] ");
2360 len = 7;
2361 }
2362 else len = -3;
2363 while (len++ < maxaddlen) fprintf(f," ");
2364 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
2365 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2366 #ifndef DISABLE_DNSSEC
2367 fprintf(f, " ad=%s", h->dnssec==DS_YES ? "yes" : "no");
2368 #else
2369 fprintf(f, " ad=no");
2370 #endif
2371 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2372 fprintf(f, "\n");
2373 }
2374 }
2375 }
2376 }
2377
2378 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2379 the -bv or -bt case). */
2380
2381 out:
2382 tls_modify_variables(&tls_in);
2383
2384 return yield;
2385 }
2386
2387
2388
2389
2390 /*************************************************
2391 * Check headers for syntax errors *
2392 *************************************************/
2393
2394 /* This function checks those header lines that contain addresses, and verifies
2395 that all the addresses therein are syntactially correct.
2396
2397 Arguments:
2398 msgptr where to put an error message
2399
2400 Returns: OK
2401 FAIL
2402 */
2403
2404 int
2405 verify_check_headers(uschar **msgptr)
2406 {
2407 header_line *h;
2408 uschar *colon, *s;
2409 int yield = OK;
2410
2411 for (h = header_list; h != NULL && yield == OK; h = h->next)
2412 {
2413 if (h->type != htype_from &&
2414 h->type != htype_reply_to &&
2415 h->type != htype_sender &&
2416 h->type != htype_to &&
2417 h->type != htype_cc &&
2418 h->type != htype_bcc)
2419 continue;
2420
2421 colon = Ustrchr(h->text, ':');
2422 s = colon + 1;
2423 while (isspace(*s)) s++;
2424
2425 /* Loop for multiple addresses in the header, enabling group syntax. Note
2426 that we have to reset this after the header has been scanned. */
2427
2428 parse_allow_group = TRUE;
2429
2430 while (*s != 0)
2431 {
2432 uschar *ss = parse_find_address_end(s, FALSE);
2433 uschar *recipient, *errmess;
2434 int terminator = *ss;
2435 int start, end, domain;
2436
2437 /* Temporarily terminate the string at this point, and extract the
2438 operative address within, allowing group syntax. */
2439
2440 *ss = 0;
2441 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2442 *ss = terminator;
2443
2444 /* Permit an unqualified address only if the message is local, or if the
2445 sending host is configured to be permitted to send them. */
2446
2447 if (recipient != NULL && domain == 0)
2448 {
2449 if (h->type == htype_from || h->type == htype_sender)
2450 {
2451 if (!allow_unqualified_sender) recipient = NULL;
2452 }
2453 else
2454 {
2455 if (!allow_unqualified_recipient) recipient = NULL;
2456 }
2457 if (recipient == NULL) errmess = US"unqualified address not permitted";
2458 }
2459
2460 /* It's an error if no address could be extracted, except for the special
2461 case of an empty address. */
2462
2463 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2464 {
2465 uschar *verb = US"is";
2466 uschar *t = ss;
2467 uschar *tt = colon;
2468 int len;
2469
2470 /* Arrange not to include any white space at the end in the
2471 error message or the header name. */
2472
2473 while (t > s && isspace(t[-1])) t--;
2474 while (tt > h->text && isspace(tt[-1])) tt--;
2475
2476 /* Add the address that failed to the error message, since in a
2477 header with very many addresses it is sometimes hard to spot
2478 which one is at fault. However, limit the amount of address to
2479 quote - cases have been seen where, for example, a missing double
2480 quote in a humungous To: header creates an "address" that is longer
2481 than string_sprintf can handle. */
2482
2483 len = t - s;
2484 if (len > 1024)
2485 {
2486 len = 1024;
2487 verb = US"begins";
2488 }
2489
2490 /* deconst cast ok as we're passing a non-const to string_printing() */
2491 *msgptr = US string_printing(
2492 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2493 errmess, tt - h->text, h->text, verb, len, s));
2494
2495 yield = FAIL;
2496 break; /* Out of address loop */
2497 }
2498
2499 /* Advance to the next address */
2500
2501 s = ss + (terminator? 1:0);
2502 while (isspace(*s)) s++;
2503 } /* Next address */
2504
2505 parse_allow_group = FALSE;
2506 parse_found_group = FALSE;
2507 } /* Next header unless yield has been set FALSE */
2508
2509 return yield;
2510 }
2511
2512
2513 /*************************************************
2514 * Check header names for 8-bit characters *
2515 *************************************************/
2516
2517 /* This function checks for invalid charcters in header names. See
2518 RFC 5322, 2.2. and RFC 6532, 3.
2519
2520 Arguments:
2521 msgptr where to put an error message
2522
2523 Returns: OK
2524 FAIL
2525 */
2526
2527 int
2528 verify_check_header_names_ascii(uschar **msgptr)
2529 {
2530 header_line *h;
2531 uschar *colon, *s;
2532
2533 for (h = header_list; h != NULL; h = h->next)
2534 {
2535 colon = Ustrchr(h->text, ':');
2536 for(s = h->text; s < colon; s++)
2537 {
2538 if ((*s < 33) || (*s > 126))
2539 {
2540 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2541 colon - h->text, h->text);
2542 return FAIL;
2543 }
2544 }
2545 }
2546 return OK;
2547 }
2548
2549 /*************************************************
2550 * Check for blind recipients *
2551 *************************************************/
2552
2553 /* This function checks that every (envelope) recipient is mentioned in either
2554 the To: or Cc: header lines, thus detecting blind carbon copies.
2555
2556 There are two ways of scanning that could be used: either scan the header lines
2557 and tick off the recipients, or scan the recipients and check the header lines.
2558 The original proposed patch did the former, but I have chosen to do the latter,
2559 because (a) it requires no memory and (b) will use fewer resources when there
2560 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2561
2562 Arguments: none
2563 Returns: OK if there are no blind recipients
2564 FAIL if there is at least one blind recipient
2565 */
2566
2567 int
2568 verify_check_notblind(void)
2569 {
2570 int i;
2571 for (i = 0; i < recipients_count; i++)
2572 {
2573 header_line *h;
2574 BOOL found = FALSE;
2575 uschar *address = recipients_list[i].address;
2576
2577 for (h = header_list; !found && h != NULL; h = h->next)
2578 {
2579 uschar *colon, *s;
2580
2581 if (h->type != htype_to && h->type != htype_cc) continue;
2582
2583 colon = Ustrchr(h->text, ':');
2584 s = colon + 1;
2585 while (isspace(*s)) s++;
2586
2587 /* Loop for multiple addresses in the header, enabling group syntax. Note
2588 that we have to reset this after the header has been scanned. */
2589
2590 parse_allow_group = TRUE;
2591
2592 while (*s != 0)
2593 {
2594 uschar *ss = parse_find_address_end(s, FALSE);
2595 uschar *recipient,*errmess;
2596 int terminator = *ss;
2597 int start, end, domain;
2598
2599 /* Temporarily terminate the string at this point, and extract the
2600 operative address within, allowing group syntax. */
2601
2602 *ss = 0;
2603 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2604 *ss = terminator;
2605
2606 /* If we found a valid recipient that has a domain, compare it with the
2607 envelope recipient. Local parts are compared case-sensitively, domains
2608 case-insensitively. By comparing from the start with length "domain", we
2609 include the "@" at the end, which ensures that we are comparing the whole
2610 local part of each address. */
2611
2612 if (recipient != NULL && domain != 0)
2613 {
2614 found = Ustrncmp(recipient, address, domain) == 0 &&
2615 strcmpic(recipient + domain, address + domain) == 0;
2616 if (found) break;
2617 }
2618
2619 /* Advance to the next address */
2620
2621 s = ss + (terminator? 1:0);
2622 while (isspace(*s)) s++;
2623 } /* Next address */
2624
2625 parse_allow_group = FALSE;
2626 parse_found_group = FALSE;
2627 } /* Next header (if found is false) */
2628
2629 if (!found) return FAIL;
2630 } /* Next recipient */
2631
2632 return OK;
2633 }
2634
2635
2636
2637 /*************************************************
2638 * Find if verified sender *
2639 *************************************************/
2640
2641 /* Usually, just a single address is verified as the sender of the message.
2642 However, Exim can be made to verify other addresses as well (often related in
2643 some way), and this is useful in some environments. There may therefore be a
2644 chain of such addresses that have previously been tested. This function finds
2645 whether a given address is on the chain.
2646
2647 Arguments: the address to be verified
2648 Returns: pointer to an address item, or NULL
2649 */
2650
2651 address_item *
2652 verify_checked_sender(uschar *sender)
2653 {
2654 address_item *addr;
2655 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2656 if (Ustrcmp(sender, addr->address) == 0) break;
2657 return addr;
2658 }
2659
2660
2661
2662
2663
2664 /*************************************************
2665 * Get valid header address *
2666 *************************************************/
2667
2668 /* Scan the originator headers of the message, looking for an address that
2669 verifies successfully. RFC 822 says:
2670
2671 o The "Sender" field mailbox should be sent notices of
2672 any problems in transport or delivery of the original
2673 messages. If there is no "Sender" field, then the
2674 "From" field mailbox should be used.
2675
2676 o If the "Reply-To" field exists, then the reply should
2677 go to the addresses indicated in that field and not to
2678 the address(es) indicated in the "From" field.
2679
2680 So we check a Sender field if there is one, else a Reply_to field, else a From
2681 field. As some strange messages may have more than one of these fields,
2682 especially if they are resent- fields, check all of them if there is more than
2683 one.
2684
2685 Arguments:
2686 user_msgptr points to where to put a user error message
2687 log_msgptr points to where to put a log error message
2688 callout timeout for callout check (passed to verify_address())
2689 callout_overall overall callout timeout (ditto)
2690 callout_connect connect callout timeout (ditto)
2691 se_mailfrom mailfrom for verify; NULL => ""
2692 pm_mailfrom sender for pm callout check (passed to verify_address())
2693 options callout options (passed to verify_address())
2694 verrno where to put the address basic_errno
2695
2696 If log_msgptr is set to something without setting user_msgptr, the caller
2697 normally uses log_msgptr for both things.
2698
2699 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2700 FAIL is given if no appropriate headers are found
2701 */
2702
2703 int
2704 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2705 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2706 uschar *pm_mailfrom, int options, int *verrno)
2707 {
2708 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2709 BOOL done = FALSE;
2710 int yield = FAIL;
2711 int i;
2712
2713 for (i = 0; i < 3 && !done; i++)
2714 {
2715 header_line *h;
2716 for (h = header_list; h != NULL && !done; h = h->next)
2717 {
2718 int terminator, new_ok;
2719 uschar *s, *ss, *endname;
2720
2721 if (h->type != header_types[i]) continue;
2722 s = endname = Ustrchr(h->text, ':') + 1;
2723
2724 /* Scan the addresses in the header, enabling group syntax. Note that we
2725 have to reset this after the header has been scanned. */
2726
2727 parse_allow_group = TRUE;
2728
2729 while (*s != 0)
2730 {
2731 address_item *vaddr;
2732
2733 while (isspace(*s) || *s == ',') s++;
2734 if (*s == 0) break; /* End of header */
2735
2736 ss = parse_find_address_end(s, FALSE);
2737
2738 /* The terminator is a comma or end of header, but there may be white
2739 space preceding it (including newline for the last address). Move back
2740 past any white space so we can check against any cached envelope sender
2741 address verifications. */
2742
2743 while (isspace(ss[-1])) ss--;
2744 terminator = *ss;
2745 *ss = 0;
2746
2747 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2748 (int)(endname - h->text), h->text, s);
2749
2750 /* See if we have already verified this address as an envelope sender,
2751 and if so, use the previous answer. */
2752
2753 vaddr = verify_checked_sender(s);
2754
2755 if (vaddr != NULL && /* Previously checked */
2756 (callout <= 0 || /* No callout needed; OR */
2757 vaddr->special_action > 256)) /* Callout was done */
2758 {
2759 new_ok = vaddr->special_action & 255;
2760 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2761 *ss = terminator; /* Restore shortened string */
2762 }
2763
2764 /* Otherwise we run the verification now. We must restore the shortened
2765 string before running the verification, so the headers are correct, in
2766 case there is any rewriting. */
2767
2768 else
2769 {
2770 int start, end, domain;
2771 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2772 &domain, FALSE);
2773
2774 *ss = terminator;
2775
2776 /* If we found an empty address, just carry on with the next one, but
2777 kill the message. */
2778
2779 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2780 {
2781 *log_msgptr = NULL;
2782 s = ss;
2783 continue;
2784 }
2785
2786 /* If verification failed because of a syntax error, fail this
2787 function, and ensure that the failing address gets added to the error
2788 message. */
2789
2790 if (address == NULL)
2791 {
2792 new_ok = FAIL;
2793 while (ss > s && isspace(ss[-1])) ss--;
2794 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2795 "scanning for sender: %s in \"%.*s\"",
2796 endname - h->text, h->text, *log_msgptr, ss - s, s);
2797 yield = FAIL;
2798 done = TRUE;
2799 break;
2800 }
2801
2802 /* Else go ahead with the sender verification. But it isn't *the*
2803 sender of the message, so set vopt_fake_sender to stop sender_address
2804 being replaced after rewriting or qualification. */
2805
2806 else
2807 {
2808 vaddr = deliver_make_addr(address, FALSE);
2809 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2810 callout, callout_overall, callout_connect, se_mailfrom,
2811 pm_mailfrom, NULL);
2812 }
2813 }
2814
2815 /* We now have the result, either newly found, or cached. If we are
2816 giving out error details, set a specific user error. This means that the
2817 last of these will be returned to the user if all three fail. We do not
2818 set a log message - the generic one below will be used. */
2819
2820 if (new_ok != OK)
2821 {
2822 *verrno = vaddr->basic_errno;
2823 if (smtp_return_error_details)
2824 {
2825 *user_msgptr = string_sprintf("Rejected after DATA: "
2826 "could not verify \"%.*s\" header address\n%s: %s",
2827 endname - h->text, h->text, vaddr->address, vaddr->message);
2828 }
2829 }
2830
2831 /* Success or defer */
2832
2833 if (new_ok == OK)
2834 {
2835 yield = OK;
2836 done = TRUE;
2837 break;
2838 }
2839
2840 if (new_ok == DEFER) yield = DEFER;
2841
2842 /* Move on to any more addresses in the header */
2843
2844 s = ss;
2845 } /* Next address */
2846
2847 parse_allow_group = FALSE;
2848 parse_found_group = FALSE;
2849 } /* Next header, unless done */
2850 } /* Next header type unless done */
2851
2852 if (yield == FAIL && *log_msgptr == NULL)
2853 *log_msgptr = US"there is no valid sender in any header line";
2854
2855 if (yield == DEFER && *log_msgptr == NULL)
2856 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2857
2858 return yield;
2859 }
2860
2861
2862
2863
2864 /*************************************************
2865 * Get RFC 1413 identification *
2866 *************************************************/
2867
2868 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2869 the timeout is set to zero, then the query is not done. There may also be lists
2870 of hosts and nets which are exempt. To guard against malefactors sending
2871 non-printing characters which could, for example, disrupt a message's headers,
2872 make sure the string consists of printing characters only.
2873
2874 Argument:
2875 port the port to connect to; usually this is IDENT_PORT (113), but when
2876 running in the test harness with -bh a different value is used.
2877
2878 Returns: nothing
2879
2880 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2881 */
2882
2883 void
2884 verify_get_ident(int port)
2885 {
2886 int sock, host_af, qlen;
2887 int received_sender_port, received_interface_port, n;
2888 uschar *p;
2889 uschar buffer[2048];
2890
2891 /* Default is no ident. Check whether we want to do an ident check for this
2892 host. */
2893
2894 sender_ident = NULL;
2895 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2896 return;
2897
2898 DEBUG(D_ident) debug_printf("doing ident callback\n");
2899
2900 /* Set up a connection to the ident port of the remote host. Bind the local end
2901 to the incoming interface address. If the sender host address is an IPv6
2902 address, the incoming interface address will also be IPv6. */
2903
2904 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2905 sock = ip_socket(SOCK_STREAM, host_af);
2906 if (sock < 0) return;
2907
2908 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2909 {
2910 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2911 strerror(errno));
2912 goto END_OFF;
2913 }
2914
2915 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2916 < 0)
2917 {
2918 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2919 {
2920 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2921 sender_host_address);
2922 }
2923 else
2924 {
2925 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2926 sender_host_address, strerror(errno));
2927 }
2928 goto END_OFF;
2929 }
2930
2931 /* Construct and send the query. */
2932
2933 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2934 qlen = Ustrlen(buffer);
2935 if (send(sock, buffer, qlen, 0) < 0)
2936 {
2937 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2938 goto END_OFF;
2939 }
2940
2941 /* Read a response line. We put it into the rest of the buffer, using several
2942 recv() calls if necessary. */
2943
2944 p = buffer + qlen;
2945
2946 for (;;)
2947 {
2948 uschar *pp;
2949 int count;
2950 int size = sizeof(buffer) - (p - buffer);
2951
2952 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2953 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2954 if (count <= 0) goto END_OFF; /* Read error or EOF */
2955
2956 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2957 generous, and accept a plain \n terminator as well. The only illegal
2958 character is 0. */
2959
2960 for (pp = p; pp < p + count; pp++)
2961 {
2962 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2963 if (*pp == '\n')
2964 {
2965 if (pp[-1] == '\r') pp--;
2966 *pp = 0;
2967 goto GOT_DATA; /* Break out of both loops */
2968 }
2969 }
2970
2971 /* Reached the end of the data without finding \n. Let the loop continue to
2972 read some more, if there is room. */
2973
2974 p = pp;
2975 }
2976
2977 GOT_DATA:
2978
2979 /* We have received a line of data. Check it carefully. It must start with the
2980 same two port numbers that we sent, followed by data as defined by the RFC. For
2981 example,
2982
2983 12345 , 25 : USERID : UNIX :root
2984
2985 However, the amount of white space may be different to what we sent. In the
2986 "osname" field there may be several sub-fields, comma separated. The data we
2987 actually want to save follows the third colon. Some systems put leading spaces
2988 in it - we discard those. */
2989
2990 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2991 &received_interface_port, &n) != 2 ||
2992 received_sender_port != sender_host_port ||
2993 received_interface_port != interface_port)
2994 goto END_OFF;
2995
2996 p = buffer + qlen + n;
2997 while(isspace(*p)) p++;
2998 if (*p++ != ':') goto END_OFF;
2999 while(isspace(*p)) p++;
3000 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
3001 p += 6;
3002 while(isspace(*p)) p++;
3003 if (*p++ != ':') goto END_OFF;
3004 while (*p != 0 && *p != ':') p++;
3005 if (*p++ == 0) goto END_OFF;
3006 while(isspace(*p)) p++;
3007 if (*p == 0) goto END_OFF;
3008
3009 /* The rest of the line is the data we want. We turn it into printing
3010 characters when we save it, so that it cannot mess up the format of any logging
3011 or Received: lines into which it gets inserted. We keep a maximum of 127
3012 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
3013
3014 sender_ident = US string_printing(string_copyn(p, 127));
3015 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
3016
3017 END_OFF:
3018 (void)close(sock);
3019 return;
3020 }
3021
3022
3023
3024
3025 /*************************************************
3026 * Match host to a single host-list item *
3027 *************************************************/
3028
3029 /* This function compares a host (name or address) against a single item
3030 from a host list. The host name gets looked up if it is needed and is not
3031 already known. The function is called from verify_check_this_host() via
3032 match_check_list(), which is why most of its arguments are in a single block.
3033
3034 Arguments:
3035 arg the argument block (see below)
3036 ss the host-list item
3037 valueptr where to pass back looked up data, or NULL
3038 error for error message when returning ERROR
3039
3040 The block contains:
3041 host_name (a) the host name, or
3042 (b) NULL, implying use sender_host_name and
3043 sender_host_aliases, looking them up if required, or
3044 (c) the empty string, meaning that only IP address matches
3045 are permitted
3046 host_address the host address
3047 host_ipv4 the IPv4 address taken from an IPv6 one
3048
3049 Returns: OK matched
3050 FAIL did not match
3051 DEFER lookup deferred
3052 ERROR (a) failed to find the host name or IP address, or
3053 (b) unknown lookup type specified, or
3054 (c) host name encountered when only IP addresses are
3055 being matched
3056 */
3057
3058 int
3059 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
3060 {
3061 check_host_block *cb = (check_host_block *)arg;
3062 int mlen = -1;
3063 int maskoffset;
3064 BOOL iplookup = FALSE;
3065 BOOL isquery = FALSE;
3066 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
3067 const uschar *t;
3068 uschar *semicolon;
3069 uschar **aliases;
3070
3071 /* Optimize for the special case when the pattern is "*". */
3072
3073 if (*ss == '*' && ss[1] == 0) return OK;
3074
3075 /* If the pattern is empty, it matches only in the case when there is no host -
3076 this can occur in ACL checking for SMTP input using the -bs option. In this
3077 situation, the host address is the empty string. */
3078
3079 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
3080 if (*ss == 0) return FAIL;
3081
3082 /* If the pattern is precisely "@" then match against the primary host name,
3083 provided that host name matching is permitted; if it's "@[]" match against the
3084 local host's IP addresses. */
3085
3086 if (*ss == '@')
3087 {
3088 if (ss[1] == 0)
3089 {
3090 if (isiponly) return ERROR;
3091 ss = primary_hostname;
3092 }
3093 else if (Ustrcmp(ss, "@[]") == 0)
3094 {
3095 ip_address_item *ip;
3096 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
3097 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
3098 return FAIL;
3099 }
3100 }
3101
3102 /* If the pattern is an IP address, optionally followed by a bitmask count, do
3103 a (possibly masked) comparision with the current IP address. */
3104
3105 if (string_is_ip_address(ss, &maskoffset) != 0)
3106 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
3107
3108 /* The pattern is not an IP address. A common error that people make is to omit
3109 one component of an IPv4 address, either by accident, or believing that, for
3110 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,
3111 which it isn't. (Those applications that do accept 1.2.3 as an IP address
3112 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
3113 ancient specification.) To aid in debugging these cases, we give a specific
3114 error if the pattern contains only digits and dots or contains a slash preceded
3115 only by digits and dots (a slash at the start indicates a file name and of
3116 course slashes may be present in lookups, but not preceded only by digits and
3117 dots). */
3118
3119 for (t = ss; isdigit(*t) || *t == '.'; t++);
3120 if (*t == 0 || (*t == '/' && t != ss))
3121 {
3122 *error = US"malformed IPv4 address or address mask";
3123 return ERROR;
3124 }
3125
3126 /* See if there is a semicolon in the pattern */
3127
3128 semicolon = Ustrchr(ss, ';');
3129
3130 /* If we are doing an IP address only match, then all lookups must be IP
3131 address lookups, even if there is no "net-". */
3132
3133 if (isiponly)
3134 {
3135 iplookup = semicolon != NULL;
3136 }
3137
3138 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
3139 a lookup on a masked IP network, in textual form. We obey this code even if we
3140 have already set iplookup, so as to skip over the "net-" prefix and to set the
3141 mask length. The net- stuff really only applies to single-key lookups where the
3142 key is implicit. For query-style lookups the key is specified in the query.
3143 From release 4.30, the use of net- for query style is no longer needed, but we
3144 retain it for backward compatibility. */
3145
3146 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
3147 {
3148 mlen = 0;
3149 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
3150 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
3151 iplookup = (*t++ == '-');
3152 }
3153 else t = ss;
3154
3155 /* Do the IP address lookup if that is indeed what we have */
3156
3157 if (iplookup)
3158 {
3159 int insize;
3160 int search_type;
3161 int incoming[4];
3162 void *handle;
3163 uschar *filename, *key, *result;
3164 uschar buffer[64];
3165
3166 /* Find the search type */
3167
3168 search_type = search_findtype(t, semicolon - t);
3169
3170 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3171 search_error_message);
3172
3173 /* Adjust parameters for the type of lookup. For a query-style lookup, there
3174 is no file name, and the "key" is just the query. For query-style with a file
3175 name, we have to fish the file off the start of the query. For a single-key
3176 lookup, the key is the current IP address, masked appropriately, and
3177 reconverted to text form, with the mask appended. For IPv6 addresses, specify
3178 dot separators instead of colons, except when the lookup type is "iplsearch".
3179 */
3180
3181 if (mac_islookup(search_type, lookup_absfilequery))
3182 {
3183 filename = semicolon + 1;
3184 key = filename;
3185 while (*key != 0 && !isspace(*key)) key++;
3186 filename = string_copyn(filename, key - filename);
3187 while (isspace(*key)) key++;
3188 }
3189 else if (mac_islookup(search_type, lookup_querystyle))
3190 {
3191 filename = NULL;
3192 key = semicolon + 1;
3193 }
3194 else /* Single-key style */
3195 {
3196 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3197 ':' : '.';
3198 insize = host_aton(cb->host_address, incoming);
3199 host_mask(insize, incoming, mlen);
3200 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3201 key = buffer;
3202 filename = semicolon + 1;
3203 }
3204
3205 /* Now do the actual lookup; note that there is no search_close() because
3206 of the caching arrangements. */
3207
3208 handle = search_open(filename, search_type, 0, NULL, NULL);
3209 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3210 search_error_message);
3211 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3212 if (valueptr != NULL) *valueptr = result;
3213 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3214 }
3215
3216 /* The pattern is not an IP address or network reference of any kind. That is,
3217 it is a host name pattern. If this is an IP only match, there's an error in the
3218 host list. */
3219
3220 if (isiponly)
3221 {
3222 *error = US"cannot match host name in match_ip list";
3223 return ERROR;
3224 }
3225
3226 /* Check the characters of the pattern to see if they comprise only letters,
3227 digits, full stops, and hyphens (the constituents of domain names). Allow
3228 underscores, as they are all too commonly found. Sigh. Also, if
3229 allow_utf8_domains is set, allow top-bit characters. */
3230
3231 for (t = ss; *t != 0; t++)
3232 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3233 (!allow_utf8_domains || *t < 128)) break;
3234
3235 /* If the pattern is a complete domain name, with no fancy characters, look up
3236 its IP address and match against that. Note that a multi-homed host will add
3237 items to the chain. */
3238
3239 if (*t == 0)
3240 {
3241 int rc;
3242 host_item h;
3243 h.next = NULL;
3244 h.name = ss;
3245 h.address = NULL;
3246 h.mx = MX_NONE;
3247
3248 /* Using byname rather than bydns here means we cannot determine dnssec
3249 status. On the other hand it is unclear how that could be either
3250 propagated up or enforced. */
3251
3252 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3253 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3254 {
3255 host_item *hh;
3256 for (hh = &h; hh != NULL; hh = hh->next)
3257 {
3258 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3259 }
3260 return FAIL;
3261 }
3262 if (rc == HOST_FIND_AGAIN) return DEFER;
3263 *error = string_sprintf("failed to find IP address for %s", ss);
3264 return ERROR;
3265 }
3266
3267 /* Almost all subsequent comparisons require the host name, and can be done
3268 using the general string matching function. When this function is called for
3269 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3270 must use sender_host_name and its aliases, looking them up if necessary. */
3271
3272 if (cb->host_name != NULL) /* Explicit host name given */
3273 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3274 valueptr);
3275
3276 /* Host name not given; in principle we need the sender host name and its
3277 aliases. However, for query-style lookups, we do not need the name if the
3278 query does not contain $sender_host_name. From release 4.23, a reference to
3279 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3280 on spec. */
3281
3282 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3283 {
3284 const uschar *affix;
3285 int partial, affixlen, starflags, id;
3286
3287 *semicolon = 0;
3288 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3289 *semicolon=';';
3290
3291 if (id < 0) /* Unknown lookup type */
3292 {
3293 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3294 search_error_message, ss);
3295 return DEFER;
3296 }
3297 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3298 }
3299
3300 if (isquery)
3301 {
3302 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3303 {
3304 case OK: return OK;
3305 case DEFER: return DEFER;
3306 default: return FAIL;
3307 }
3308 }
3309
3310 /* Not a query-style lookup; must ensure the host name is present, and then we
3311 do a check on the name and all its aliases. */
3312
3313 if (sender_host_name == NULL)
3314 {
3315 HDEBUG(D_host_lookup)
3316 debug_printf("sender host name required, to match against %s\n", ss);
3317 if (host_lookup_failed || host_name_lookup() != OK)
3318 {
3319 *error = string_sprintf("failed to find host name for %s",
3320 sender_host_address);;
3321 return ERROR;
3322 }
3323 host_build_sender_fullhost();
3324 }
3325
3326 /* Match on the sender host name, using the general matching function */
3327
3328 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3329 valueptr))
3330 {
3331 case OK: return OK;
3332 case DEFER: return DEFER;
3333 }
3334
3335 /* If there are aliases, try matching on them. */
3336
3337 aliases = sender_host_aliases;
3338 while (*aliases != NULL)
3339 {
3340 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3341 {
3342 case OK: return OK;
3343 case DEFER: return DEFER;
3344 }
3345 }
3346 return FAIL;
3347 }
3348
3349
3350
3351
3352 /*************************************************
3353 * Check a specific host matches a host list *
3354 *************************************************/
3355
3356 /* This function is passed a host list containing items in a number of
3357 different formats and the identity of a host. Its job is to determine whether
3358 the given host is in the set of hosts defined by the list. The host name is
3359 passed as a pointer so that it can be looked up if needed and not already
3360 known. This is commonly the case when called from verify_check_host() to check
3361 an incoming connection. When called from elsewhere the host name should usually
3362 be set.
3363
3364 This function is now just a front end to match_check_list(), which runs common
3365 code for scanning a list. We pass it the check_host() function to perform a
3366 single test.
3367
3368 Arguments:
3369 listptr pointer to the host list
3370 cache_bits pointer to cache for named lists, or NULL
3371 host_name the host name or NULL, implying use sender_host_name and
3372 sender_host_aliases, looking them up if required
3373 host_address the IP address
3374 valueptr if not NULL, data from a lookup is passed back here
3375
3376 Returns: OK if the host is in the defined set
3377 FAIL if the host is not in the defined set,
3378 DEFER if a data lookup deferred (not a host lookup)
3379
3380 If the host name was needed in order to make a comparison, and could not be
3381 determined from the IP address, the result is FAIL unless the item
3382 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3383
3384 int
3385 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3386 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3387 {
3388 int rc;
3389 unsigned int *local_cache_bits = cache_bits;
3390 const uschar *save_host_address = deliver_host_address;
3391 check_host_block cb;
3392 cb.host_name = host_name;
3393 cb.host_address = host_address;
3394
3395 if (valueptr != NULL) *valueptr = NULL;
3396
3397 /* If the host address starts off ::ffff: it is an IPv6 address in
3398 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3399 addresses. */
3400
3401 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3402 host_address + 7 : host_address;
3403
3404 /* During the running of the check, put the IP address into $host_address. In
3405 the case of calls from the smtp transport, it will already be there. However,
3406 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3407 the safe side, any existing setting is preserved, though as I write this
3408 (November 2004) I can't see any cases where it is actually needed. */
3409
3410 deliver_host_address = host_address;
3411 rc = match_check_list(
3412 listptr, /* the list */
3413 0, /* separator character */
3414 &hostlist_anchor, /* anchor pointer */
3415 &local_cache_bits, /* cache pointer */
3416 check_host, /* function for testing */
3417 &cb, /* argument for function */
3418 MCL_HOST, /* type of check */
3419 (host_address == sender_host_address)?
3420 US"host" : host_address, /* text for debugging */
3421 valueptr); /* where to pass back data */
3422 deliver_host_address = save_host_address;
3423 return rc;
3424 }
3425
3426
3427
3428
3429 /*************************************************
3430 * Check the given host item matches a list *
3431 *************************************************/
3432 int
3433 verify_check_given_host(uschar **listptr, host_item *host)
3434 {
3435 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3436 }
3437
3438 /*************************************************
3439 * Check the remote host matches a list *
3440 *************************************************/
3441
3442 /* This is a front end to verify_check_this_host(), created because checking
3443 the remote host is a common occurrence. With luck, a good compiler will spot
3444 the tail recursion and optimize it. If there's no host address, this is
3445 command-line SMTP input - check against an empty string for the address.
3446
3447 Arguments:
3448 listptr pointer to the host list
3449
3450 Returns: the yield of verify_check_this_host(),
3451 i.e. OK, FAIL, or DEFER
3452 */
3453
3454 int
3455 verify_check_host(uschar **listptr)
3456 {
3457 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3458 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3459 }
3460
3461
3462
3463
3464
3465 /*************************************************
3466 * Invert an IP address *
3467 *************************************************/
3468
3469 /* Originally just used for DNS xBL lists, now also used for the
3470 reverse_ip expansion operator.
3471
3472 Arguments:
3473 buffer where to put the answer
3474 address the address to invert
3475 */
3476
3477 void
3478 invert_address(uschar *buffer, uschar *address)
3479 {
3480 int bin[4];
3481 uschar *bptr = buffer;
3482
3483 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3484 to the IPv4 part only. */
3485
3486 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3487
3488 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3489 always 1. */
3490
3491 if (host_aton(address, bin) == 1)
3492 {
3493 int i;
3494 int x = bin[0];
3495 for (i = 0; i < 4; i++)
3496 {
3497 sprintf(CS bptr, "%d.", x & 255);
3498 while (*bptr) bptr++;
3499 x >>= 8;
3500 }
3501 }
3502
3503 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3504 in any DNS black lists, and the format in which they will be looked up is
3505 unknown. This is just a guess. */
3506
3507 #if HAVE_IPV6
3508 else
3509 {
3510 int i, j;
3511 for (j = 3; j >= 0; j--)
3512 {
3513 int x = bin[j];
3514 for (i = 0; i < 8; i++)
3515 {
3516 sprintf(CS bptr, "%x.", x & 15);
3517 while (*bptr) bptr++;
3518 x >>= 4;
3519 }
3520 }
3521 }
3522 #endif
3523
3524 /* Remove trailing period -- this is needed so that both arbitrary
3525 dnsbl keydomains and inverted addresses may be combined with the
3526 same format string, "%s.%s" */
3527
3528 *(--bptr) = 0;
3529 }
3530
3531
3532
3533 /*************************************************
3534 * Perform a single dnsbl lookup *
3535 *************************************************/
3536
3537 /* This function is called from verify_check_dnsbl() below. It is also called
3538 recursively from within itself when domain and domain_txt are different
3539 pointers, in order to get the TXT record from the alternate domain.
3540
3541 Arguments:
3542 domain the outer dnsbl domain
3543 domain_txt alternate domain to lookup TXT record on success; when the
3544 same domain is to be used, domain_txt == domain (that is,
3545 the pointers must be identical, not just the text)
3546 keydomain the current keydomain (for debug message)
3547 prepend subdomain to lookup (like keydomain, but
3548 reversed if IP address)
3549 iplist the list of matching IP addresses, or NULL for "any"
3550 bitmask true if bitmask matching is wanted
3551 match_type condition for 'succeed' result
3552 0 => Any RR in iplist (=)
3553 1 => No RR in iplist (!=)
3554 2 => All RRs in iplist (==)
3555 3 => Some RRs not in iplist (!==)
3556 the two bits are defined as MT_NOT and MT_ALL
3557 defer_return what to return for a defer
3558
3559 Returns: OK if lookup succeeded
3560 FAIL if not
3561 */
3562
3563 static int
3564 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3565 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3566 int defer_return)
3567 {
3568 dns_answer dnsa;
3569 dns_scan dnss;
3570 tree_node *t;
3571 dnsbl_cache_block *cb;
3572 int old_pool = store_pool;
3573 uschar query[256]; /* DNS domain max length */
3574
3575 /* Construct the specific query domainname */
3576
3577 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3578 {
3579 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3580 "(ignored): %s...", query);
3581 return FAIL;
3582 }
3583
3584 /* Look for this query in the cache. */
3585
3586 t = tree_search(dnsbl_cache, query);
3587
3588 /* If not cached from a previous lookup, we must do a DNS lookup, and
3589 cache the result in permanent memory. */
3590
3591 if (t == NULL)
3592 {
3593 store_pool = POOL_PERM;
3594
3595 /* Set up a tree entry to cache the lookup */
3596
3597 t = store_get(sizeof(tree_node) + Ustrlen(query));
3598 Ustrcpy(t->name, query);
3599 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3600 (void)tree_insertnode(&dnsbl_cache, t);
3601
3602 /* Do the DNS loopup . */
3603
3604 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3605 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3606 cb->text_set = FALSE;
3607 cb->text = NULL;
3608 cb->rhs = NULL;
3609
3610 /* If the lookup succeeded, cache the RHS address. The code allows for
3611 more than one address - this was for complete generality and the possible
3612 use of A6 records. However, A6 records have been reduced to experimental
3613 status (August 2001) and may die out. So they may never get used at all,
3614 let alone in dnsbl records. However, leave the code here, just in case.
3615
3616 Quite apart from one A6 RR generating multiple addresses, there are DNS
3617 lists that return more than one A record, so we must handle multiple
3618 addresses generated in that way as well. */
3619
3620 if (cb->rc == DNS_SUCCEED)
3621 {
3622 dns_record *rr;
3623 dns_address **addrp = &(cb->rhs);
3624 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3625 rr;
3626 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3627 {
3628 if (rr->type == T_A)
3629 {
3630 dns_address *da = dns_address_from_rr(&dnsa, rr);
3631 if (da)
3632 {
3633 *addrp = da;
3634 while (da->next != NULL) da = da->next;
3635 addrp = &(da->next);
3636 }
3637 }
3638 }
3639
3640 /* If we didn't find any A records, change the return code. This can
3641 happen when there is a CNAME record but there are no A records for what
3642 it points to. */
3643
3644 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3645 }
3646
3647 store_pool = old_pool;
3648 }
3649
3650 /* Previous lookup was cached */
3651
3652 else
3653 {
3654 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3655 cb = t->data.ptr;
3656 }
3657
3658 /* We now have the result of the DNS lookup, either newly done, or cached
3659 from a previous call. If the lookup succeeded, check against the address
3660 list if there is one. This may be a positive equality list (introduced by
3661 "="), a negative equality list (introduced by "!="), a positive bitmask
3662 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3663
3664 if (cb->rc == DNS_SUCCEED)
3665 {
3666 dns_address *da = NULL;
3667 uschar *addlist = cb->rhs->address;
3668
3669 /* For A and AAAA records, there may be multiple addresses from multiple
3670 records. For A6 records (currently not expected to be used) there may be
3671 multiple addresses from a single record. */
3672
3673 for (da = cb->rhs->next; da != NULL; da = da->next)
3674 addlist = string_sprintf("%s, %s", addlist, da->address);
3675
3676 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3677 query, addlist);
3678
3679 /* Address list check; this can be either for equality, or via a bitmask.
3680 In the latter case, all the bits must match. */
3681
3682 if (iplist != NULL)
3683 {
3684 for (da = cb->rhs; da != NULL; da = da->next)
3685 {
3686 int ipsep = ',';
3687 uschar ip[46];
3688 const uschar *ptr = iplist;
3689 uschar *res;
3690
3691 /* Handle exact matching */
3692
3693 if (!bitmask)
3694 {
3695 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3696 {
3697 if (Ustrcmp(CS da->address, ip) == 0) break;
3698 }
3699 }
3700
3701 /* Handle bitmask matching */
3702
3703 else
3704 {
3705 int address[4];
3706 int mask = 0;
3707
3708 /* At present, all known DNS blocking lists use A records, with
3709 IPv4 addresses on the RHS encoding the information they return. I
3710 wonder if this will linger on as the last vestige of IPv4 when IPv6
3711 is ubiquitous? Anyway, for now we use paranoia code to completely
3712 ignore IPv6 addresses. The default mask is 0, which always matches.
3713 We change this only for IPv4 addresses in the list. */
3714
3715 if (host_aton(da->address, address) == 1) mask = address[0];
3716
3717 /* Scan the returned addresses, skipping any that are IPv6 */
3718
3719 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3720 {
3721 if (host_aton(ip, address) != 1) continue;
3722 if ((address[0] & mask) == address[0]) break;
3723 }
3724 }
3725
3726 /* If either
3727
3728 (a) An IP address in an any ('=') list matched, or
3729 (b) No IP address in an all ('==') list matched
3730
3731 then we're done searching. */
3732
3733 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3734 }
3735
3736 /* If da == NULL, either
3737
3738 (a) No IP address in an any ('=') list matched, or
3739 (b) An IP address in an all ('==') list didn't match
3740
3741 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3742 the list. */
3743
3744 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3745 {
3746 HDEBUG(D_dnsbl)
3747 {
3748 uschar *res = NULL;
3749 switch(match_type)
3750 {
3751 case 0:
3752 res = US"was no match";
3753 break;
3754 case MT_NOT:
3755 res = US"was an exclude match";
3756 break;
3757 case MT_ALL:
3758 res = US"was an IP address that did not match";
3759 break;
3760 case MT_NOT|MT_ALL:
3761 res = US"were no IP addresses that did not match";
3762 break;
3763 }
3764 debug_printf("=> but we are not accepting this block class because\n");
3765 debug_printf("=> there %s for %s%c%s\n",
3766 res,
3767 ((match_type & MT_ALL) == 0)? "" : "=",
3768 bitmask? '&' : '=', iplist);
3769 }
3770 return FAIL;
3771 }
3772 }
3773
3774 /* Either there was no IP list, or the record matched, implying that the
3775 domain is on the list. We now want to find a corresponding TXT record. If an
3776 alternate domain is specified for the TXT record, call this function
3777 recursively to look that up; this has the side effect of re-checking that
3778 there is indeed an A record at the alternate domain. */
3779
3780 if (domain_txt != domain)
3781 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3782 FALSE, match_type, defer_return);
3783
3784 /* If there is no alternate domain, look up a TXT record in the main domain
3785 if it has not previously been cached. */
3786
3787 if (!cb->text_set)
3788 {
3789 cb->text_set = TRUE;
3790 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3791 {
3792 dns_record *rr;
3793 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3794 rr != NULL;
3795 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3796 if (rr->type == T_TXT) break;
3797 if (rr != NULL)
3798 {
3799 int len = (rr->data)[0];
3800 if (len > 511) len = 127;
3801 store_pool = POOL_PERM;
3802 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3803 store_pool = old_pool;
3804 }
3805 }
3806 }
3807
3808 dnslist_value = addlist;
3809 dnslist_text = cb->text;
3810 return OK;
3811 }
3812
3813 /* There was a problem with the DNS lookup */
3814
3815 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3816 {
3817 log_write(L_dnslist_defer, LOG_MAIN,
3818 "DNS list lookup defer (probably timeout) for %s: %s", query,
3819 (defer_return == OK)? US"assumed in list" :
3820 (defer_return == FAIL)? US"assumed not in list" :
3821 US"returned DEFER");
3822 return defer_return;
3823 }
3824
3825 /* No entry was found in the DNS; continue for next domain */
3826
3827 HDEBUG(D_dnsbl)
3828 {
3829 debug_printf("DNS lookup for %s failed\n", query);
3830 debug_printf("=> that means %s is not listed at %s\n",
3831 keydomain, domain);
3832 }
3833
3834 return FAIL;
3835 }
3836
3837
3838
3839
3840 /*************************************************
3841 * Check host against DNS black lists *
3842 *************************************************/
3843
3844 /* This function runs checks against a list of DNS black lists, until one
3845 matches. Each item on the list can be of the form
3846
3847 domain=ip-address/key
3848
3849 The domain is the right-most domain that is used for the query, for example,
3850 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3851 if the DNS lookup returns a matching IP address. Several addresses may be
3852 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3853
3854 If no key is given, what is looked up in the domain is the inverted IP address
3855 of the current client host. If a key is given, it is used to construct the
3856 domain for the lookup. For example:
3857
3858 dsn.rfc-ignorant.org/$sender_address_domain
3859
3860 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3861 then we check for a TXT record for an error message, and if found, save its
3862 value in $dnslist_text. We also cache everything in a tree, to optimize
3863 multiple lookups.
3864
3865 The TXT record is normally looked up in the same domain as the A record, but
3866 when many lists are combined in a single DNS domain, this will not be a very
3867 specific message. It is possible to specify a different domain for looking up
3868 TXT records; this is given before the main domain, comma-separated. For
3869 example:
3870
3871 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3872 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3873
3874 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3875
3876 Note: an address for testing RBL is 192.203.178.39
3877 Note: an address for testing DUL is 192.203.178.4
3878 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3879
3880 Arguments:
3881 listptr the domain/address/data list
3882
3883 Returns: OK successful lookup (i.e. the address is on the list), or
3884 lookup deferred after +include_unknown
3885 FAIL name not found, or no data found for the given type, or
3886 lookup deferred after +exclude_unknown (default)
3887 DEFER lookup failure, if +defer_unknown was set
3888 */
3889
3890 int
3891 verify_check_dnsbl(const uschar **listptr)
3892 {
3893 int sep = 0;
3894 int defer_return = FAIL;
3895 const uschar *list = *listptr;
3896 uschar *domain;
3897 uschar *s;
3898 uschar buffer[1024];
3899 uschar revadd[128]; /* Long enough for IPv6 address */
3900
3901 /* Indicate that the inverted IP address is not yet set up */
3902
3903 revadd[0] = 0;
3904
3905 /* In case this is the first time the DNS resolver is being used. */
3906
3907 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3908
3909 /* Loop through all the domains supplied, until something matches */
3910
3911 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3912 {
3913 int rc;
3914 BOOL bitmask = FALSE;
3915 int match_type = 0;
3916 uschar *domain_txt;
3917 uschar *comma;
3918 uschar *iplist;
3919 uschar *key;
3920
3921 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3922
3923 /* Deal with special values that change the behaviour on defer */
3924
3925 if (domain[0] == '+')
3926 {
3927 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3928 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3929 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3930 else
3931 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3932 domain);
3933 continue;
3934 }
3935
3936 /* See if there's explicit data to be looked up */
3937
3938 key = Ustrchr(domain, '/');
3939 if (key != NULL) *key++ = 0;
3940
3941 /* See if there's a list of addresses supplied after the domain name. This is
3942 introduced by an = or a & character; if preceded by = we require all matches
3943 and if preceded by ! we invert the result. */
3944
3945 iplist = Ustrchr(domain, '=');
3946 if (iplist == NULL)
3947 {
3948 bitmask = TRUE;
3949 iplist = Ustrchr(domain, '&');
3950 }
3951
3952 if (iplist != NULL) /* Found either = or & */
3953 {
3954 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3955 {
3956 match_type |= MT_NOT;
3957 iplist[-1] = 0;
3958 }
3959
3960 *iplist++ = 0; /* Terminate domain, move on */
3961
3962 /* If we found = (bitmask == FALSE), check for == or =& */
3963
3964 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3965 {
3966 bitmask = *iplist++ == '&';
3967 match_type |= MT_ALL;
3968 }
3969 }
3970
3971 /* If there is a comma in the domain, it indicates that a second domain for
3972 looking up TXT records is provided, before the main domain. Otherwise we must
3973 set domain_txt == domain. */
3974
3975 domain_txt = domain;
3976 comma = Ustrchr(domain, ',');
3977 if (comma != NULL)
3978 {
3979 *comma++ = 0;
3980 domain = comma;
3981 }
3982
3983 /* Check that what we have left is a sensible domain name. There is no reason
3984 why these domains should in fact use the same syntax as hosts and email
3985 domains, but in practice they seem to. However, there is little point in
3986 actually causing an error here, because that would no doubt hold up incoming
3987 mail. Instead, I'll just log it. */
3988
3989 for (s = domain; *s != 0; s++)
3990 {
3991 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3992 {
3993 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3994 "strange characters - is this right?", domain);
3995 break;
3996 }
3997 }
3998
3999 /* Check the alternate domain if present */
4000
4001 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
4002 {
4003 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
4004 {
4005 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
4006 "strange characters - is this right?", domain_txt);
4007 break;
4008 }
4009 }
4010
4011 /* If there is no key string, construct the query by adding the domain name
4012 onto the inverted host address, and perform a single DNS lookup. */
4013
4014 if (key == NULL)
4015 {
4016 if (sender_host_address == NULL) return FAIL; /* can never match */
4017 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
4018 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
4019 iplist, bitmask, match_type, defer_return);
4020 if (rc == OK)
4021 {
4022 dnslist_domain = string_copy(domain_txt);
4023 dnslist_matched = string_copy(sender_host_address);
4024 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4025 sender_host_address, dnslist_domain);
4026 }
4027 if (rc != FAIL) return rc; /* OK or DEFER */
4028 }
4029
4030 /* If there is a key string, it can be a list of domains or IP addresses to
4031 be concatenated with the main domain. */
4032
4033 else
4034 {
4035 int keysep = 0;
4036 BOOL defer = FALSE;
4037 uschar *keydomain;
4038 uschar keybuffer[256];
4039 uschar keyrevadd[128];
4040
4041 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
4042 sizeof(keybuffer))) != NULL)
4043 {
4044 uschar *prepend = keydomain;
4045
4046 if (string_is_ip_address(keydomain, NULL) != 0)
4047 {
4048 invert_address(keyrevadd, keydomain);