aa7988cef4be4a8234b7339914fe20b3183500df
[exim.git] / src / src / verify.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
10
11
12 #include "exim.h"
13 #include "transports/smtp.h"
14
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
19
20
21 /* Structure for caching DNSBL lookups */
22
23 typedef struct dnsbl_cache_block {
24 time_t expiry;
25 dns_address *rhs;
26 uschar *text;
27 int rc;
28 BOOL text_set;
29 } dnsbl_cache_block;
30
31
32 /* Anchor for DNSBL cache */
33
34 static tree_node *dnsbl_cache = NULL;
35
36
37 /* Bits for match_type in one_check_dnsbl() */
38
39 #define MT_NOT 1
40 #define MT_ALL 2
41
42 static uschar cutthrough_response(char, uschar **);
43
44
45
46 /*************************************************
47 * Retrieve a callout cache record *
48 *************************************************/
49
50 /* If a record exists, check whether it has expired.
51
52 Arguments:
53 dbm_file an open hints file
54 key the record key
55 type "address" or "domain"
56 positive_expire expire time for positive records
57 negative_expire expire time for negative records
58
59 Returns: the cache record if a non-expired one exists, else NULL
60 */
61
62 static dbdata_callout_cache *
63 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
64 int positive_expire, int negative_expire)
65 {
66 BOOL negative;
67 int length, expire;
68 time_t now;
69 dbdata_callout_cache *cache_record;
70
71 cache_record = dbfn_read_with_length(dbm_file, key, &length);
72
73 if (cache_record == NULL)
74 {
75 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
76 return NULL;
77 }
78
79 /* We treat a record as "negative" if its result field is not positive, or if
80 it is a domain record and the postmaster field is negative. */
81
82 negative = cache_record->result != ccache_accept ||
83 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
84 expire = negative? negative_expire : positive_expire;
85 now = time(NULL);
86
87 if (now - cache_record->time_stamp > expire)
88 {
89 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
90 return NULL;
91 }
92
93 /* If this is a non-reject domain record, check for the obsolete format version
94 that doesn't have the postmaster and random timestamps, by looking at the
95 length. If so, copy it to a new-style block, replicating the record's
96 timestamp. Then check the additional timestamps. (There's no point wasting
97 effort if connections are rejected.) */
98
99 if (type[0] == 'd' && cache_record->result != ccache_reject)
100 {
101 if (length == sizeof(dbdata_callout_cache_obs))
102 {
103 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
104 memcpy(new, cache_record, length);
105 new->postmaster_stamp = new->random_stamp = new->time_stamp;
106 cache_record = new;
107 }
108
109 if (now - cache_record->postmaster_stamp > expire)
110 cache_record->postmaster_result = ccache_unknown;
111
112 if (now - cache_record->random_stamp > expire)
113 cache_record->random_result = ccache_unknown;
114 }
115
116 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
117 return cache_record;
118 }
119
120
121
122 /*************************************************
123 * Do callout verification for an address *
124 *************************************************/
125
126 /* This function is called from verify_address() when the address has routed to
127 a host list, and a callout has been requested. Callouts are expensive; that is
128 why a cache is used to improve the efficiency.
129
130 Arguments:
131 addr the address that's been routed
132 host_list the list of hosts to try
133 tf the transport feedback block
134
135 ifstring "interface" option from transport, or NULL
136 portstring "port" option from transport, or NULL
137 protocolstring "protocol" option from transport, or NULL
138 callout the per-command callout timeout
139 callout_overall the overall callout timeout (if < 0 use 4*callout)
140 callout_connect the callout connection timeout (if < 0 use callout)
141 options the verification options - these bits are used:
142 vopt_is_recipient => this is a recipient address
143 vopt_callout_no_cache => don't use callout cache
144 vopt_callout_fullpm => if postmaster check, do full one
145 vopt_callout_random => do the "random" thing
146 vopt_callout_recipsender => use real sender for recipient
147 vopt_callout_recippmaster => use postmaster for recipient
148 se_mailfrom MAIL FROM address for sender verify; NULL => ""
149 pm_mailfrom if non-NULL, do the postmaster check with this sender
150
151 Returns: OK/FAIL/DEFER
152 */
153
154 static int
155 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
156 int callout, int callout_overall, int callout_connect, int options,
157 uschar *se_mailfrom, uschar *pm_mailfrom)
158 {
159 int yield = OK;
160 int old_domain_cache_result = ccache_accept;
161 BOOL done = FALSE;
162 uschar *address_key;
163 uschar *from_address;
164 uschar *random_local_part = NULL;
165 const uschar *save_deliver_domain = deliver_domain;
166 uschar **failure_ptr = options & vopt_is_recipient
167 ? &recipient_verify_failure : &sender_verify_failure;
168 open_db dbblock;
169 open_db *dbm_file = NULL;
170 dbdata_callout_cache new_domain_record;
171 dbdata_callout_cache_address new_address_record;
172 host_item *host;
173 time_t callout_start_time;
174 uschar peer_offered = 0;
175
176 new_domain_record.result = ccache_unknown;
177 new_domain_record.postmaster_result = ccache_unknown;
178 new_domain_record.random_result = ccache_unknown;
179
180 memset(&new_address_record, 0, sizeof(new_address_record));
181
182 /* For a recipient callout, the key used for the address cache record must
183 include the sender address if we are using the real sender in the callout,
184 because that may influence the result of the callout. */
185
186 address_key = addr->address;
187 from_address = US"";
188
189 if (options & vopt_is_recipient)
190 {
191 if (options & vopt_callout_recipsender)
192 {
193 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
194 from_address = sender_address;
195 if (cutthrough.delivery) options |= vopt_callout_no_cache;
196 }
197 else if (options & vopt_callout_recippmaster)
198 {
199 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
200 qualify_domain_sender);
201 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
202 }
203 }
204
205 /* For a sender callout, we must adjust the key if the mailfrom address is not
206 empty. */
207
208 else
209 {
210 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
211 if (from_address[0] != 0)
212 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
213 }
214
215 /* Open the callout cache database, it it exists, for reading only at this
216 stage, unless caching has been disabled. */
217
218 if (options & vopt_callout_no_cache)
219 {
220 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
221 }
222 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
223 {
224 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
225 }
226
227 /* If a cache database is available see if we can avoid the need to do an
228 actual callout by making use of previously-obtained data. */
229
230 if (dbm_file)
231 {
232 dbdata_callout_cache_address *cache_address_record;
233 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
234 addr->domain, US"domain",
235 callout_cache_domain_positive_expire,
236 callout_cache_domain_negative_expire);
237
238 /* If an unexpired cache record was found for this domain, see if the callout
239 process can be short-circuited. */
240
241 if (cache_record)
242 {
243 /* In most cases, if an early command (up to and including MAIL FROM:<>)
244 was rejected, there is no point carrying on. The callout fails. However, if
245 we are doing a recipient verification with use_sender or use_postmaster
246 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
247 will be using a non-empty sender. We have to remember this situation so as
248 not to disturb the cached domain value if this whole verification succeeds
249 (we don't want it turning into "accept"). */
250
251 old_domain_cache_result = cache_record->result;
252
253 if (cache_record->result == ccache_reject ||
254 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
255 {
256 setflag(addr, af_verify_nsfail);
257 HDEBUG(D_verify)
258 debug_printf("callout cache: domain gave initial rejection, or "
259 "does not accept HELO or MAIL FROM:<>\n");
260 setflag(addr, af_verify_nsfail);
261 addr->user_message = US"(result of an earlier callout reused).";
262 yield = FAIL;
263 *failure_ptr = US"mail";
264 goto END_CALLOUT;
265 }
266
267 /* If a previous check on a "random" local part was accepted, we assume
268 that the server does not do any checking on local parts. There is therefore
269 no point in doing the callout, because it will always be successful. If a
270 random check previously failed, arrange not to do it again, but preserve
271 the data in the new record. If a random check is required but hasn't been
272 done, skip the remaining cache processing. */
273
274 if (options & vopt_callout_random) switch(cache_record->random_result)
275 {
276 case ccache_accept:
277 HDEBUG(D_verify)
278 debug_printf("callout cache: domain accepts random addresses\n");
279 goto END_CALLOUT; /* Default yield is OK */
280
281 case ccache_reject:
282 HDEBUG(D_verify)
283 debug_printf("callout cache: domain rejects random addresses\n");
284 options &= ~vopt_callout_random;
285 new_domain_record.random_result = ccache_reject;
286 new_domain_record.random_stamp = cache_record->random_stamp;
287 break;
288
289 default:
290 HDEBUG(D_verify)
291 debug_printf("callout cache: need to check random address handling "
292 "(not cached or cache expired)\n");
293 goto END_CACHE;
294 }
295
296 /* If a postmaster check is requested, but there was a previous failure,
297 there is again no point in carrying on. If a postmaster check is required,
298 but has not been done before, we are going to have to do a callout, so skip
299 remaining cache processing. */
300
301 if (pm_mailfrom)
302 {
303 if (cache_record->postmaster_result == ccache_reject)
304 {
305 setflag(addr, af_verify_pmfail);
306 HDEBUG(D_verify)
307 debug_printf("callout cache: domain does not accept "
308 "RCPT TO:<postmaster@domain>\n");
309 yield = FAIL;
310 *failure_ptr = US"postmaster";
311 setflag(addr, af_verify_pmfail);
312 addr->user_message = US"(result of earlier verification reused).";
313 goto END_CALLOUT;
314 }
315 if (cache_record->postmaster_result == ccache_unknown)
316 {
317 HDEBUG(D_verify)
318 debug_printf("callout cache: need to check RCPT "
319 "TO:<postmaster@domain> (not cached or cache expired)\n");
320 goto END_CACHE;
321 }
322
323 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
324 postmaster check if the address itself has to be checked. Also ensure
325 that the value in the cache record is preserved (with its old timestamp).
326 */
327
328 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
329 "TO:<postmaster@domain>\n");
330 pm_mailfrom = NULL;
331 new_domain_record.postmaster_result = ccache_accept;
332 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
333 }
334 }
335
336 /* We can't give a result based on information about the domain. See if there
337 is an unexpired cache record for this specific address (combined with the
338 sender address if we are doing a recipient callout with a non-empty sender).
339 */
340
341 cache_address_record = (dbdata_callout_cache_address *)
342 get_callout_cache_record(dbm_file,
343 address_key, US"address",
344 callout_cache_positive_expire,
345 callout_cache_negative_expire);
346
347 if (cache_address_record)
348 {
349 if (cache_address_record->result == ccache_accept)
350 {
351 HDEBUG(D_verify)
352 debug_printf("callout cache: address record is positive\n");
353 }
354 else
355 {
356 HDEBUG(D_verify)
357 debug_printf("callout cache: address record is negative\n");
358 addr->user_message = US"Previous (cached) callout verification failure";
359 *failure_ptr = US"recipient";
360 yield = FAIL;
361 }
362 goto END_CALLOUT;
363 }
364
365 /* Close the cache database while we actually do the callout for real. */
366
367 END_CACHE:
368 dbfn_close(dbm_file);
369 dbm_file = NULL;
370 }
371
372 if (!addr->transport)
373 {
374 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
375 }
376 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
377 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
378 addr->transport->name, addr->transport->driver_name);
379 else
380 {
381 smtp_transport_options_block *ob =
382 (smtp_transport_options_block *)addr->transport->options_block;
383
384 /* The information wasn't available in the cache, so we have to do a real
385 callout and save the result in the cache for next time, unless no_cache is set,
386 or unless we have a previously cached negative random result. If we are to test
387 with a random local part, ensure that such a local part is available. If not,
388 log the fact, but carry on without randomming. */
389
390 if (options & vopt_callout_random && callout_random_local_part != NULL)
391 if (!(random_local_part = expand_string(callout_random_local_part)))
392 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
393 "callout_random_local_part: %s", expand_string_message);
394
395 /* Default the connect and overall callout timeouts if not set, and record the
396 time we are starting so that we can enforce it. */
397
398 if (callout_overall < 0) callout_overall = 4 * callout;
399 if (callout_connect < 0) callout_connect = callout;
400 callout_start_time = time(NULL);
401
402 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
403 output because a callout might take some time. When PIPELINING is active and
404 there are many recipients, the total time for doing lots of callouts can add up
405 and cause the client to time out. So in this case we forgo the PIPELINING
406 optimization. */
407
408 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
409
410 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
411 and we are holding a cutthrough conn open, we can just append the rcpt to
412 that conn for verification purposes (and later delivery also). Simplest
413 coding means skipping this whole loop and doing the append separately.
414
415 We will need to remember it has been appended so that rcpt-acl tail code
416 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
417 */
418
419 /* Can we re-use an open cutthrough connection? */
420 if ( cutthrough.fd >= 0
421 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
422 == vopt_callout_recipsender
423 && !random_local_part
424 && !pm_mailfrom
425 )
426 {
427 if (addr->transport == cutthrough.addr.transport)
428 for (host = host_list; host; host = host->next)
429 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
430 {
431 int host_af;
432 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
433 int port = 25;
434
435 deliver_host = host->name;
436 deliver_host_address = host->address;
437 deliver_host_port = host->port;
438 deliver_domain = addr->domain;
439 transport_name = addr->transport->name;
440
441 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
442
443 if (!smtp_get_interface(tf->interface, host_af, addr, &interface,
444 US"callout") ||
445 !smtp_get_port(tf->port, addr, &port, US"callout"))
446 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
447 addr->message);
448
449 if ( ( interface == cutthrough.interface
450 || ( interface
451 && cutthrough.interface
452 && Ustrcmp(interface, cutthrough.interface) == 0
453 ) )
454 && port == cutthrough.host.port
455 )
456 {
457 uschar * resp = NULL;
458
459 /* Match! Send the RCPT TO, append the addr, set done */
460 done =
461 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
462 transport_rcpt_address(addr,
463 (addr->transport == NULL)? FALSE :
464 addr->transport->rcpt_include_affixes)) >= 0 &&
465 cutthrough_response('2', &resp) == '2';
466
467 /* This would go horribly wrong if a callout fail was ignored by ACL.
468 We punt by abandoning cutthrough on a reject, like the
469 first-rcpt does. */
470
471 if (done)
472 {
473 address_item * na = store_get(sizeof(address_item));
474 *na = cutthrough.addr;
475 cutthrough.addr = *addr;
476 cutthrough.addr.host_used = &cutthrough.host;
477 cutthrough.addr.next = na;
478
479 cutthrough.nrcpt++;
480 }
481 else
482 {
483 cancel_cutthrough_connection("recipient rejected");
484 if (!resp || errno == ETIMEDOUT)
485 {
486 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
487 }
488 else if (errno == 0)
489 {
490 if (*resp == 0)
491 Ustrcpy(resp, US"connection dropped");
492
493 addr->message =
494 string_sprintf("response to \"%s\" from %s [%s] was: %s",
495 big_buffer, host->name, host->address,
496 string_printing(resp));
497
498 addr->user_message =
499 string_sprintf("Callout verification failed:\n%s", resp);
500
501 /* Hard rejection ends the process */
502
503 if (resp[0] == '5') /* Address rejected */
504 {
505 yield = FAIL;
506 done = TRUE;
507 }
508 }
509 }
510 }
511 break;
512 }
513 if (!done)
514 cancel_cutthrough_connection("incompatible connection");
515 }
516
517 /* Now make connections to the hosts and do real callouts. The list of hosts
518 is passed in as an argument. */
519
520 for (host = host_list; host && !done; host = host->next)
521 {
522 smtp_inblock inblock;
523 smtp_outblock outblock;
524 int host_af;
525 int port = 25;
526 BOOL send_quit = TRUE;
527 uschar *active_hostname = smtp_active_hostname;
528 BOOL lmtp;
529 BOOL smtps;
530 BOOL esmtp;
531 BOOL suppress_tls = FALSE;
532 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
533 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
534 BOOL dane = FALSE;
535 BOOL dane_required;
536 dns_answer tlsa_dnsa;
537 #endif
538 uschar inbuffer[4096];
539 uschar outbuffer[1024];
540 uschar responsebuffer[4096];
541 uschar * size_str;
542
543 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
544 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
545
546 /* Skip this host if we don't have an IP address for it. */
547
548 if (!host->address)
549 {
550 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
551 host->name);
552 continue;
553 }
554
555 /* Check the overall callout timeout */
556
557 if (time(NULL) - callout_start_time >= callout_overall)
558 {
559 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
560 break;
561 }
562
563 /* Set IPv4 or IPv6 */
564
565 host_af = Ustrchr(host->address, ':') == NULL ? AF_INET : AF_INET6;
566
567 /* Expand and interpret the interface and port strings. The latter will not
568 be used if there is a host-specific port (e.g. from a manualroute router).
569 This has to be delayed till now, because they may expand differently for
570 different hosts. If there's a failure, log it, but carry on with the
571 defaults. */
572
573 deliver_host = host->name;
574 deliver_host_address = host->address;
575 deliver_host_port = host->port;
576 deliver_domain = addr->domain;
577 transport_name = addr->transport->name;
578
579 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
580 US"callout")
581 || !smtp_get_port(tf->port, addr, &port, US"callout")
582 )
583 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
584 addr->message);
585
586 /* Set HELO string according to the protocol */
587 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
588 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
589
590
591 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
592
593 /* Set up the buffer for reading SMTP response packets. */
594
595 inblock.buffer = inbuffer;
596 inblock.buffersize = sizeof(inbuffer);
597 inblock.ptr = inbuffer;
598 inblock.ptrend = inbuffer;
599
600 /* Set up the buffer for holding SMTP commands while pipelining */
601
602 outblock.buffer = outbuffer;
603 outblock.buffersize = sizeof(outbuffer);
604 outblock.ptr = outbuffer;
605 outblock.cmd_count = 0;
606 outblock.authenticating = FALSE;
607
608 /* Connect to the host; on failure, just loop for the next one, but we
609 set the error for the last one. Use the callout_connect timeout. */
610
611 tls_retry_connection:
612
613 /* Reset the parameters of a TLS session */
614 tls_out.cipher = tls_out.peerdn = tls_out.peercert = NULL;
615
616 inblock.sock = outblock.sock =
617 smtp_connect(host, host_af, port, interface, callout_connect,
618 addr->transport);
619 if (inblock.sock < 0)
620 {
621 HDEBUG(D_verify) debug_printf("connect: %s\n", strerror(errno));
622 addr->message = string_sprintf("could not connect to %s [%s]: %s",
623 host->name, host->address, strerror(errno));
624 transport_name = NULL;
625 deliver_host = deliver_host_address = NULL;
626 deliver_domain = save_deliver_domain;
627 continue;
628 }
629
630 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
631 {
632 int rc;
633
634 tls_out.dane_verified = FALSE;
635 tls_out.tlsa_usage = 0;
636
637 dane_required =
638 verify_check_given_host(&ob->hosts_require_dane, host) == OK;
639
640 if (host->dnssec == DS_YES)
641 {
642 if( dane_required
643 || verify_check_given_host(&ob->hosts_try_dane, host) == OK
644 )
645 {
646 if ((rc = tlsa_lookup(host, &tlsa_dnsa, dane_required)) != OK)
647 return rc;
648 dane = TRUE;
649 }
650 }
651 else if (dane_required)
652 {
653 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
654 return FAIL;
655 }
656
657 if (dane)
658 ob->tls_tempfail_tryclear = FALSE;
659 }
660 #endif /*DANE*/
661
662 /* Expand the helo_data string to find the host name to use. */
663
664 if (tf->helo_data)
665 {
666 uschar * s = expand_string(tf->helo_data);
667 if (!s)
668 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
669 "helo_data value for callout: %s", addr->address,
670 expand_string_message);
671 else active_hostname = s;
672 }
673
674 /* Wait for initial response, and send HELO. The smtp_write_command()
675 function leaves its command in big_buffer. This is used in error responses.
676 Initialize it in case the connection is rejected. */
677
678 Ustrcpy(big_buffer, "initial connection");
679
680 /* Unless ssl-on-connect, wait for the initial greeting */
681 smtps_redo_greeting:
682
683 #ifdef SUPPORT_TLS
684 if (!smtps || (smtps && tls_out.active >= 0))
685 #endif
686 {
687 #ifdef TCP_QUICKACK
688 (void) setsockopt(inblock.sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
689 #endif
690 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
691 goto RESPONSE_FAILED;
692
693 #ifndef DISABLE_EVENT
694 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
695 : host->dnssec==DS_NO ? US"no" : NULL;
696 if (event_raise(addr->transport->event_action,
697 US"smtp:connect", responsebuffer))
698 {
699 lookup_dnssec_authenticated = NULL;
700 /* Logging? Debug? */
701 goto RESPONSE_FAILED;
702 }
703 lookup_dnssec_authenticated = NULL;
704 #endif
705 }
706
707 /* Not worth checking greeting line for ESMTP support */
708 if (!(esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK))
709 DEBUG(D_transport)
710 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
711
712 tls_redo_helo:
713
714 #ifdef SUPPORT_TLS
715 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
716 {
717 peer_offered &= ~PEER_OFFERED_TLS;
718 ob->tls_tempfail_tryclear = FALSE;
719 }
720 else /* all other cases */
721 #endif
722
723 { esmtp_retry:
724
725 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
726 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
727 goto SEND_FAILED;
728 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
729 {
730 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
731 {
732 done= FALSE;
733 goto RESPONSE_FAILED;
734 }
735 #ifdef SUPPORT_TLS
736 peer_offered &= ~PEER_OFFERED_TLS;
737 #endif
738 esmtp = FALSE;
739 goto esmtp_retry; /* fallback to HELO */
740 }
741
742 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
743
744 peer_offered = esmtp
745 ? ehlo_response(responsebuffer, sizeof(responsebuffer),
746 (!suppress_tls && tls_out.active < 0 ? PEER_OFFERED_TLS : 0)
747 | 0 /* no IGNQ */
748 | 0 /* no PRDR */
749 #ifdef SUPPORT_I18N
750 | (addr->prop.utf8_msg && !addr->prop.utf8_downcvt
751 ? PEER_OFFERED_UTF8 : 0)
752 #endif
753 | 0 /* no DSN */
754 | 0 /* no PIPE */
755
756 /* only care about SIZE if we have size from inbound */
757 | (message_size > 0 && ob->size_addition >= 0
758 ? PEER_OFFERED_SIZE : 0)
759 )
760 : 0;
761 }
762
763 size_str = options & vopt_is_recipient && peer_offered & PEER_OFFERED_SIZE
764 ? string_sprintf(" SIZE=%d", message_size + ob->size_addition) : US"";
765
766 #ifdef SUPPORT_TLS
767 smtp_peer_options |= peer_offered & PEER_OFFERED_TLS;
768 #endif
769
770 /* If TLS is available on this connection attempt to
771 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
772 send another EHLO - the server may give a different answer in secure mode. We
773 use a separate buffer for reading the response to STARTTLS so that if it is
774 negative, the original EHLO data is available for subsequent analysis, should
775 the client not be required to use TLS. If the response is bad, copy the buffer
776 for error analysis. */
777
778 #ifdef SUPPORT_TLS
779 if ( peer_offered & PEER_OFFERED_TLS
780 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK
781 && verify_check_given_host(&ob->hosts_verify_avoid_tls, host) != OK
782 )
783 {
784 uschar buffer2[4096];
785 if ( !smtps
786 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
787 goto SEND_FAILED;
788
789 /* If there is an I/O error, transmission of this message is deferred. If
790 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
791 false, we also defer. However, if there is a temporary rejection of STARTTLS
792 and tls_tempfail_tryclear is true, or if there is an outright rejection of
793 STARTTLS, we carry on. This means we will try to send the message in clear,
794 unless the host is in hosts_require_tls (tested below). */
795
796 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
797 ob->command_timeout))
798 {
799 if ( errno != 0
800 || buffer2[0] == 0
801 || buffer2[0] == '4' && !ob->tls_tempfail_tryclear
802 )
803 {
804 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
805 done= FALSE;
806 goto RESPONSE_FAILED;
807 }
808 }
809
810 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
811 else
812 {
813 int oldtimeout = ob->command_timeout;
814 int rc;
815
816 ob->command_timeout = callout;
817 rc = tls_client_start(inblock.sock, host, addr, addr->transport
818 # ifdef EXPERIMENTAL_DANE
819 , dane ? &tlsa_dnsa : NULL
820 # endif
821 );
822 ob->command_timeout = oldtimeout;
823
824 /* TLS negotiation failed; give an error. Try in clear on a new
825 connection, if the options permit it for this host. */
826 if (rc != OK)
827 {
828 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
829 (void)close(inblock.sock);
830 # ifndef DISABLE_EVENT
831 (void) event_raise(addr->transport->event_action,
832 US"tcp:close", NULL);
833 # endif
834 if ( ob->tls_tempfail_tryclear
835 && !smtps
836 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
837 )
838 {
839 log_write(0, LOG_MAIN, "TLS session failure:"
840 " callout unencrypted to %s [%s] (not in hosts_require_tls)",
841 host->name, host->address);
842 suppress_tls = TRUE;
843 goto tls_retry_connection;
844 }
845
846 /*save_errno = ERRNO_TLSFAILURE;*/
847 /*message = US"failure while setting up TLS session";*/
848 send_quit = FALSE;
849 done= FALSE;
850 goto TLS_FAILED;
851 }
852
853 /* TLS session is set up. Copy info for logging. */
854 addr->cipher = tls_out.cipher;
855 addr->peerdn = tls_out.peerdn;
856
857 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
858 if (smtps)
859 goto smtps_redo_greeting;
860
861 /* For STARTTLS we need to redo EHLO */
862 goto tls_redo_helo;
863 }
864 }
865
866 /* If the host is required to use a secure channel, ensure that we have one. */
867 if (tls_out.active < 0)
868 if (
869 # ifdef EXPERIMENTAL_DANE
870 dane ||
871 # endif
872 verify_check_given_host(&ob->hosts_require_tls, host) == OK
873 )
874 {
875 /*save_errno = ERRNO_TLSREQUIRED;*/
876 log_write(0, LOG_MAIN,
877 "H=%s [%s]: a TLS session is required for this host, but %s",
878 host->name, host->address,
879 peer_offered & PEER_OFFERED_TLS
880 ? "an attempt to start TLS failed"
881 : "the server did not offer TLS support");
882 done= FALSE;
883 goto TLS_FAILED;
884 }
885
886 #endif /*SUPPORT_TLS*/
887
888 done = TRUE; /* so far so good; have response to HELO */
889
890 /* For now, transport_filter by cutthrough-delivery is not supported */
891 /* Need proper integration with the proper transport mechanism. */
892 if (cutthrough.delivery)
893 {
894 #ifndef DISABLE_DKIM
895 uschar * s;
896 #endif
897 if (addr->transport->filter_command)
898 {
899 cutthrough.delivery = FALSE;
900 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
901 }
902 #ifndef DISABLE_DKIM
903 else if ((s = ob->dkim.dkim_domain) && (s = expand_string(s)) && *s)
904 {
905 cutthrough.delivery = FALSE;
906 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
907 }
908 #endif
909 }
910
911 SEND_FAILED:
912 RESPONSE_FAILED:
913 TLS_FAILED:
914 ;
915 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
916
917 /* Failure to accept HELO is cached; this blocks the whole domain for all
918 senders. I/O errors and defer responses are not cached. */
919
920 if (!done)
921 {
922 *failure_ptr = US"mail"; /* At or before MAIL */
923 if (errno == 0 && responsebuffer[0] == '5')
924 {
925 setflag(addr, af_verify_nsfail);
926 new_domain_record.result = ccache_reject;
927 }
928 }
929
930 #ifdef SUPPORT_I18N
931 else if ( addr->prop.utf8_msg
932 && !addr->prop.utf8_downcvt
933 && !(peer_offered & PEER_OFFERED_UTF8)
934 )
935 {
936 HDEBUG(D_acl|D_v) debug_printf("utf8 required but not offered\n");
937 errno = ERRNO_UTF8_FWD;
938 setflag(addr, af_verify_nsfail);
939 done = FALSE;
940 }
941 else if ( addr->prop.utf8_msg
942 && (addr->prop.utf8_downcvt || !(peer_offered & PEER_OFFERED_UTF8))
943 && (setflag(addr, af_utf8_downcvt),
944 from_address = string_address_utf8_to_alabel(from_address,
945 &addr->message),
946 addr->message
947 ) )
948 {
949 errno = ERRNO_EXPANDFAIL;
950 setflag(addr, af_verify_nsfail);
951 done = FALSE;
952 }
953 #endif
954
955 /* If we haven't authenticated, but are required to, give up. */
956 /* Try to AUTH */
957
958 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
959 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
960
961 /* Copy AUTH info for logging */
962 ( (addr->authenticator = client_authenticator),
963 (addr->auth_id = client_authenticated_id),
964
965 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
966 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
967 ) &&
968
969 ( (addr->auth_sndr = client_authenticated_sender),
970
971 /* Send the MAIL command */
972 (smtp_write_command(&outblock, FALSE,
973 #ifdef SUPPORT_I18N
974 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
975 ? "MAIL FROM:<%s>%s%s SMTPUTF8\r\n"
976 :
977 #endif
978 "MAIL FROM:<%s>%s%s\r\n",
979 from_address, responsebuffer, size_str) >= 0)
980 ) &&
981
982 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
983 '2', callout);
984
985 deliver_host = deliver_host_address = NULL;
986 deliver_domain = save_deliver_domain;
987
988 /* If the host does not accept MAIL FROM:<>, arrange to cache this
989 information, but again, don't record anything for an I/O error or a defer. Do
990 not cache rejections of MAIL when a non-empty sender has been used, because
991 that blocks the whole domain for all senders. */
992
993 if (!done)
994 {
995 *failure_ptr = US"mail"; /* At or before MAIL */
996 if (errno == 0 && responsebuffer[0] == '5')
997 {
998 setflag(addr, af_verify_nsfail);
999 if (from_address[0] == 0)
1000 new_domain_record.result = ccache_reject_mfnull;
1001 }
1002 }
1003
1004 /* Otherwise, proceed to check a "random" address (if required), then the
1005 given address, and the postmaster address (if required). Between each check,
1006 issue RSET, because some servers accept only one recipient after MAIL
1007 FROM:<>.
1008
1009 Before doing this, set the result in the domain cache record to "accept",
1010 unless its previous value was ccache_reject_mfnull. In that case, the domain
1011 rejects MAIL FROM:<> and we want to continue to remember that. When that is
1012 the case, we have got here only in the case of a recipient verification with
1013 a non-null sender. */
1014
1015 else
1016 {
1017 const uschar * rcpt_domain = addr->domain;
1018
1019 #ifdef SUPPORT_I18N
1020 uschar * errstr = NULL;
1021 if ( testflag(addr, af_utf8_downcvt)
1022 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
1023 &errstr), errstr)
1024 )
1025 {
1026 addr->message = errstr;
1027 errno = ERRNO_EXPANDFAIL;
1028 setflag(addr, af_verify_nsfail);
1029 done = FALSE;
1030 rcpt_domain = US""; /*XXX errorhandling! */
1031 }
1032 #endif
1033
1034 new_domain_record.result =
1035 (old_domain_cache_result == ccache_reject_mfnull)?
1036 ccache_reject_mfnull: ccache_accept;
1037
1038 /* Do the random local part check first */
1039
1040 if (random_local_part != NULL)
1041 {
1042 uschar randombuffer[1024];
1043 BOOL random_ok =
1044 smtp_write_command(&outblock, FALSE,
1045 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
1046 rcpt_domain) >= 0 &&
1047 smtp_read_response(&inblock, randombuffer,
1048 sizeof(randombuffer), '2', callout);
1049
1050 /* Remember when we last did a random test */
1051
1052 new_domain_record.random_stamp = time(NULL);
1053
1054 /* If accepted, we aren't going to do any further tests below. */
1055
1056 if (random_ok)
1057 new_domain_record.random_result = ccache_accept;
1058
1059 /* Otherwise, cache a real negative response, and get back to the right
1060 state to send RCPT. Unless there's some problem such as a dropped
1061 connection, we expect to succeed, because the commands succeeded above.
1062 However, some servers drop the connection after responding to an
1063 invalid recipient, so on (any) error we drop and remake the connection.
1064 */
1065
1066 else if (errno == 0)
1067 {
1068 /* This would be ok for 1st rcpt a cutthrough, but no way to
1069 handle a subsequent. So refuse to support any */
1070 cancel_cutthrough_connection("random-recipient");
1071
1072 if (randombuffer[0] == '5')
1073 new_domain_record.random_result = ccache_reject;
1074
1075 done =
1076 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1077 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1078 '2', callout) &&
1079
1080 smtp_write_command(&outblock, FALSE,
1081 #ifdef SUPPORT_I18N
1082 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
1083 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
1084 :
1085 #endif
1086 "MAIL FROM:<%s>\r\n",
1087 from_address) >= 0 &&
1088 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1089 '2', callout);
1090
1091 if (!done)
1092 {
1093 HDEBUG(D_acl|D_v)
1094 debug_printf("problem after random/rset/mfrom; reopen conn\n");
1095 random_local_part = NULL;
1096 #ifdef SUPPORT_TLS
1097 tls_close(FALSE, TRUE);
1098 #endif
1099 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1100 (void)close(inblock.sock);
1101 #ifndef DISABLE_EVENT
1102 (void) event_raise(addr->transport->event_action,
1103 US"tcp:close", NULL);
1104 #endif
1105 goto tls_retry_connection;
1106 }
1107 }
1108 else done = FALSE; /* Some timeout/connection problem */
1109 } /* Random check */
1110
1111 /* If the host is accepting all local parts, as determined by the "random"
1112 check, we don't need to waste time doing any further checking. */
1113
1114 if (new_domain_record.random_result != ccache_accept && done)
1115 {
1116 /* Get the rcpt_include_affixes flag from the transport if there is one,
1117 but assume FALSE if there is not. */
1118
1119 uschar * rcpt = transport_rcpt_address(addr,
1120 addr->transport ? addr->transport->rcpt_include_affixes : FALSE);
1121
1122 #ifdef SUPPORT_I18N
1123 /*XXX should the conversion be moved into transport_rcpt_address() ? */
1124 uschar * dummy_errstr = NULL;
1125 if ( testflag(addr, af_utf8_downcvt)
1126 && (rcpt = string_address_utf8_to_alabel(rcpt, &dummy_errstr),
1127 dummy_errstr
1128 ) )
1129 {
1130 errno = ERRNO_EXPANDFAIL;
1131 *failure_ptr = US"recipient";
1132 done = FALSE;
1133 }
1134 else
1135 #endif
1136
1137 done =
1138 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
1139 rcpt) >= 0 &&
1140 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
1141 '2', callout);
1142
1143 if (done)
1144 new_address_record.result = ccache_accept;
1145 else if (errno == 0 && responsebuffer[0] == '5')
1146 {
1147 *failure_ptr = US"recipient";
1148 new_address_record.result = ccache_reject;
1149 }
1150
1151 /* Do postmaster check if requested; if a full check is required, we
1152 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
1153
1154 if (done && pm_mailfrom != NULL)
1155 {
1156 /* Could possibly shift before main verify, just above, and be ok
1157 for cutthrough. But no way to handle a subsequent rcpt, so just
1158 refuse any */
1159 cancel_cutthrough_connection("postmaster verify");
1160 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
1161
1162 done =
1163 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
1164 smtp_read_response(&inblock, responsebuffer,
1165 sizeof(responsebuffer), '2', callout) &&
1166
1167 smtp_write_command(&outblock, FALSE,
1168 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
1169 smtp_read_response(&inblock, responsebuffer,
1170 sizeof(responsebuffer), '2', callout) &&
1171
1172 /* First try using the current domain */
1173
1174 ((
1175 smtp_write_command(&outblock, FALSE,
1176 "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 &&
1177 smtp_read_response(&inblock, responsebuffer,
1178 sizeof(responsebuffer), '2', callout)
1179 )
1180
1181 ||
1182
1183 /* If that doesn't work, and a full check is requested,
1184 try without the domain. */
1185
1186 (
1187 (options & vopt_callout_fullpm) != 0 &&
1188 smtp_write_command(&outblock, FALSE,
1189 "RCPT TO:<postmaster>\r\n") >= 0 &&
1190 smtp_read_response(&inblock, responsebuffer,
1191 sizeof(responsebuffer), '2', callout)
1192 ));
1193
1194 /* Sort out the cache record */
1195
1196 new_domain_record.postmaster_stamp = time(NULL);
1197
1198 if (done)
1199 new_domain_record.postmaster_result = ccache_accept;
1200 else if (errno == 0 && responsebuffer[0] == '5')
1201 {
1202 *failure_ptr = US"postmaster";
1203 setflag(addr, af_verify_pmfail);
1204 new_domain_record.postmaster_result = ccache_reject;
1205 }
1206 }
1207 } /* Random not accepted */
1208 } /* MAIL FROM: accepted */
1209
1210 /* For any failure of the main check, other than a negative response, we just
1211 close the connection and carry on. We can identify a negative response by the
1212 fact that errno is zero. For I/O errors it will be non-zero
1213
1214 Set up different error texts for logging and for sending back to the caller
1215 as an SMTP response. Log in all cases, using a one-line format. For sender
1216 callouts, give a full response to the caller, but for recipient callouts,
1217 don't give the IP address because this may be an internal host whose identity
1218 is not to be widely broadcast. */
1219
1220 if (!done)
1221 {
1222 if (errno == ETIMEDOUT)
1223 {
1224 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1225 send_quit = FALSE;
1226 }
1227 #ifdef SUPPORT_I18N
1228 else if (errno == ERRNO_UTF8_FWD)
1229 {
1230 extern int acl_where; /* src/acl.c */
1231 errno = 0;
1232 addr->message = string_sprintf(
1233 "response to \"%s\" from %s [%s] did not include SMTPUTF8",
1234 big_buffer, host->name, host->address);
1235 addr->user_message = acl_where == ACL_WHERE_RCPT
1236 ? US"533 mailbox name not allowed"
1237 : US"550 mailbox unavailable";
1238 yield = FAIL;
1239 done = TRUE;
1240 }
1241 #endif
1242 else if (errno == 0)
1243 {
1244 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1245
1246 addr->message =
1247 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1248 big_buffer, host->name, host->address,
1249 string_printing(responsebuffer));
1250
1251 addr->user_message = options & vopt_is_recipient
1252 ? string_sprintf("Callout verification failed:\n%s", responsebuffer)
1253 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1254 host->address, big_buffer, responsebuffer);
1255
1256 /* Hard rejection ends the process */
1257
1258 if (responsebuffer[0] == '5') /* Address rejected */
1259 {
1260 yield = FAIL;
1261 done = TRUE;
1262 }
1263 }
1264 }
1265
1266 /* End the SMTP conversation and close the connection. */
1267
1268 /* Cutthrough - on a successfull connect and recipient-verify with
1269 use-sender and we are 1st rcpt and have no cutthrough conn so far
1270 here is where we want to leave the conn open */
1271 if ( cutthrough.delivery
1272 && rcpt_count == 1
1273 && done
1274 && yield == OK
1275 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1276 == vopt_callout_recipsender
1277 && !random_local_part
1278 && !pm_mailfrom
1279 && cutthrough.fd < 0
1280 && !lmtp
1281 )
1282 {
1283 HDEBUG(D_acl|D_v) debug_printf("holding verify callout open for cutthrough delivery\n");
1284
1285 cutthrough.fd = outblock.sock; /* We assume no buffer in use in the outblock */
1286 cutthrough.nrcpt = 1;
1287 cutthrough.interface = interface;
1288 cutthrough.host = *host;
1289 cutthrough.addr = *addr; /* Save the address_item for later logging */
1290 cutthrough.addr.next = NULL;
1291 cutthrough.addr.host_used = &cutthrough.host;
1292 if (addr->parent)
1293 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1294 *addr->parent;
1295 ctblock.buffer = ctbuffer;
1296 ctblock.buffersize = sizeof(ctbuffer);
1297 ctblock.ptr = ctbuffer;
1298 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1299 ctblock.sock = cutthrough.fd;
1300 }
1301 else
1302 {
1303 /* Ensure no cutthrough on multiple address verifies */
1304 if (options & vopt_callout_recipsender)
1305 cancel_cutthrough_connection("not usable for cutthrough");
1306 if (send_quit)
1307 (void) smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1308
1309 #ifdef SUPPORT_TLS
1310 tls_close(FALSE, TRUE);
1311 #endif
1312 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1313 (void)close(inblock.sock);
1314 #ifndef DISABLE_EVENT
1315 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1316 #endif
1317 }
1318
1319 } /* Loop through all hosts, while !done */
1320 }
1321
1322 /* If we get here with done == TRUE, a successful callout happened, and yield
1323 will be set OK or FAIL according to the response to the RCPT command.
1324 Otherwise, we looped through the hosts but couldn't complete the business.
1325 However, there may be domain-specific information to cache in both cases.
1326
1327 The value of the result field in the new_domain record is ccache_unknown if
1328 there was an error before or with MAIL FROM:, and errno was not zero,
1329 implying some kind of I/O error. We don't want to write the cache in that case.
1330 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1331
1332 if ( !(options & vopt_callout_no_cache)
1333 && 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 for %s:\n"
1345 " result=%d postmaster=%d random=%d\n",
1346 addr->domain,
1347 new_domain_record.result,
1348 new_domain_record.postmaster_result,
1349 new_domain_record.random_result);
1350 }
1351 }
1352
1353 /* If a definite result was obtained for the callout, cache it unless caching
1354 is disabled. */
1355
1356 if (done)
1357 {
1358 if ( !(options & vopt_callout_no_cache)
1359 && new_address_record.result != ccache_unknown)
1360 {
1361 if (!dbm_file)
1362 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1363 if (!dbm_file)
1364 {
1365 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1366 }
1367 else
1368 {
1369 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1370 (int)sizeof(dbdata_callout_cache_address));
1371 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
1372 new_address_record.result == ccache_accept ? "positive" : "negative",
1373 address_key);
1374 }
1375 }
1376 } /* done */
1377
1378 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1379 temporary error. If there was only one host, and a response was received, leave
1380 it alone if supplying details. Otherwise, give a generic response. */
1381
1382 else /* !done */
1383 {
1384 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1385 options & vopt_is_recipient ? "recipient" : "sender");
1386 yield = DEFER;
1387
1388 if (host_list->next || !addr->message)
1389 addr->message = dullmsg;
1390
1391 addr->user_message = smtp_return_error_details
1392 ? string_sprintf("%s for <%s>.\n"
1393 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1394 "they may be permanently unreachable from this server. In the latter case,\n%s",
1395 dullmsg, addr->address,
1396 options & vopt_is_recipient
1397 ? "the address will never be accepted."
1398 : "you need to change the address or create an MX record for its domain\n"
1399 "if it is supposed to be generally accessible from the Internet.\n"
1400 "Talk to your mail administrator for details.")
1401 : dullmsg;
1402
1403 /* Force a specific error code */
1404
1405 addr->basic_errno = ERRNO_CALLOUTDEFER;
1406 }
1407
1408 /* Come here from within the cache-reading code on fast-track exit. */
1409
1410 END_CALLOUT:
1411 if (dbm_file) dbfn_close(dbm_file);
1412 return yield;
1413 }
1414
1415
1416
1417 /* Called after recipient-acl to get a cutthrough connection open when
1418 one was requested and a recipient-verify wasn't subsequently done.
1419 */
1420 int
1421 open_cutthrough_connection( address_item * addr )
1422 {
1423 address_item addr2;
1424 int rc;
1425
1426 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1427 /* We must use a copy of the address for verification, because it might
1428 get rewritten. */
1429
1430 addr2 = *addr;
1431 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1432 rcpt_count > 1 ? "more" : "start");
1433 rc = verify_address(&addr2, NULL,
1434 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1435 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1436 NULL, NULL, NULL);
1437 addr->message = addr2.message;
1438 addr->user_message = addr2.user_message;
1439 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1440 return rc;
1441 }
1442
1443
1444
1445 /* Send given number of bytes from the buffer */
1446 static BOOL
1447 cutthrough_send(int n)
1448 {
1449 if(cutthrough.fd < 0)
1450 return TRUE;
1451
1452 if(
1453 #ifdef SUPPORT_TLS
1454 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1455 #endif
1456 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1457 )
1458 {
1459 transport_count += n;
1460 ctblock.ptr= ctblock.buffer;
1461 return TRUE;
1462 }
1463
1464 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1465 return FALSE;
1466 }
1467
1468
1469
1470 static BOOL
1471 _cutthrough_puts(uschar * cp, int n)
1472 {
1473 while(n--)
1474 {
1475 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1476 if(!cutthrough_send(ctblock.buffersize))
1477 return FALSE;
1478
1479 *ctblock.ptr++ = *cp++;
1480 }
1481 return TRUE;
1482 }
1483
1484 /* Buffered output of counted data block. Return boolean success */
1485 BOOL
1486 cutthrough_puts(uschar * cp, int n)
1487 {
1488 if (cutthrough.fd < 0) return TRUE;
1489 if (_cutthrough_puts(cp, n)) return TRUE;
1490 cancel_cutthrough_connection("transmit failed");
1491 return FALSE;
1492 }
1493
1494
1495 static BOOL
1496 _cutthrough_flush_send(void)
1497 {
1498 int n= ctblock.ptr-ctblock.buffer;
1499
1500 if(n>0)
1501 if(!cutthrough_send(n))
1502 return FALSE;
1503 return TRUE;
1504 }
1505
1506
1507 /* Send out any bufferred output. Return boolean success. */
1508 BOOL
1509 cutthrough_flush_send(void)
1510 {
1511 if (_cutthrough_flush_send()) return TRUE;
1512 cancel_cutthrough_connection("transmit failed");
1513 return FALSE;
1514 }
1515
1516
1517 BOOL
1518 cutthrough_put_nl(void)
1519 {
1520 return cutthrough_puts(US"\r\n", 2);
1521 }
1522
1523
1524 /* Get and check response from cutthrough target */
1525 static uschar
1526 cutthrough_response(char expect, uschar ** copy)
1527 {
1528 smtp_inblock inblock;
1529 uschar inbuffer[4096];
1530 uschar responsebuffer[4096];
1531
1532 inblock.buffer = inbuffer;
1533 inblock.buffersize = sizeof(inbuffer);
1534 inblock.ptr = inbuffer;
1535 inblock.ptrend = inbuffer;
1536 inblock.sock = cutthrough.fd;
1537 /* this relies on (inblock.sock == tls_out.active) */
1538 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1539 cancel_cutthrough_connection("target timeout on read");
1540
1541 if(copy != NULL)
1542 {
1543 uschar * cp;
1544 *copy = cp = string_copy(responsebuffer);
1545 /* Trim the trailing end of line */
1546 cp += Ustrlen(responsebuffer);
1547 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1548 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1549 }
1550
1551 return responsebuffer[0];
1552 }
1553
1554
1555 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1556 BOOL
1557 cutthrough_predata(void)
1558 {
1559 if(cutthrough.fd < 0)
1560 return FALSE;
1561
1562 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1563 cutthrough_puts(US"DATA\r\n", 6);
1564 cutthrough_flush_send();
1565
1566 /* Assume nothing buffered. If it was it gets ignored. */
1567 return cutthrough_response('3', NULL) == '3';
1568 }
1569
1570
1571 /* fd and tctx args only to match write_chunk() */
1572 static BOOL
1573 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1574 {
1575 uschar * s2;
1576 while(s && (s2 = Ustrchr(s, '\n')))
1577 {
1578 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1579 return FALSE;
1580 s = s2+1;
1581 }
1582 return TRUE;
1583 }
1584
1585
1586 /* Buffered send of headers. Return success boolean. */
1587 /* Expands newlines to wire format (CR,NL). */
1588 /* Also sends header-terminating blank line. */
1589 BOOL
1590 cutthrough_headers_send(void)
1591 {
1592 transport_ctx tctx;
1593
1594 if(cutthrough.fd < 0)
1595 return FALSE;
1596
1597 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1598 but having a separate buffered-output function (for now)
1599 */
1600 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1601
1602 tctx.tblock = cutthrough.addr.transport;
1603 tctx.addr = &cutthrough.addr;
1604 tctx.check_string = US".";
1605 tctx.escape_string = US"..";
1606 tctx.options = topt_use_crlf;
1607
1608 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1609 return FALSE;
1610
1611 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1612 return TRUE;
1613 }
1614
1615
1616 static void
1617 close_cutthrough_connection(const char * why)
1618 {
1619 if(cutthrough.fd >= 0)
1620 {
1621 /* We could be sending this after a bunch of data, but that is ok as
1622 the only way to cancel the transfer in dataphase is to drop the tcp
1623 conn before the final dot.
1624 */
1625 ctblock.ptr = ctbuffer;
1626 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1627 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1628 _cutthrough_flush_send();
1629 /* No wait for response */
1630
1631 #ifdef SUPPORT_TLS
1632 tls_close(FALSE, TRUE);
1633 #endif
1634 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1635 (void)close(cutthrough.fd);
1636 cutthrough.fd = -1;
1637 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1638 }
1639 ctblock.ptr = ctbuffer;
1640 }
1641
1642 void
1643 cancel_cutthrough_connection(const char * why)
1644 {
1645 close_cutthrough_connection(why);
1646 cutthrough.delivery = FALSE;
1647 }
1648
1649
1650
1651
1652 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1653 Log an OK response as a transmission.
1654 Close the connection.
1655 Return smtp response-class digit.
1656 */
1657 uschar *
1658 cutthrough_finaldot(void)
1659 {
1660 uschar res;
1661 address_item * addr;
1662 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1663
1664 /* Assume data finshed with new-line */
1665 if( !cutthrough_puts(US".", 1)
1666 || !cutthrough_put_nl()
1667 || !cutthrough_flush_send()
1668 )
1669 return cutthrough.addr.message;
1670
1671 res = cutthrough_response('2', &cutthrough.addr.message);
1672 for (addr = &cutthrough.addr; addr; addr = addr->next)
1673 {
1674 addr->message = cutthrough.addr.message;
1675 switch(res)
1676 {
1677 case '2':
1678 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1679 close_cutthrough_connection("delivered");
1680 break;
1681
1682 case '4':
1683 delivery_log(LOG_MAIN, addr, 0,
1684 US"tmp-reject from cutthrough after DATA:");
1685 break;
1686
1687 case '5':
1688 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1689 US"rejected after DATA:");
1690 break;
1691
1692 default:
1693 break;
1694 }
1695 }
1696 return cutthrough.addr.message;
1697 }
1698
1699
1700
1701 /*************************************************
1702 * Copy error to toplevel address *
1703 *************************************************/
1704
1705 /* This function is used when a verify fails or defers, to ensure that the
1706 failure or defer information is in the original toplevel address. This applies
1707 when an address is redirected to a single new address, and the failure or
1708 deferral happens to the child address.
1709
1710 Arguments:
1711 vaddr the verify address item
1712 addr the final address item
1713 yield FAIL or DEFER
1714
1715 Returns: the value of YIELD
1716 */
1717
1718 static int
1719 copy_error(address_item *vaddr, address_item *addr, int yield)
1720 {
1721 if (addr != vaddr)
1722 {
1723 vaddr->message = addr->message;
1724 vaddr->user_message = addr->user_message;
1725 vaddr->basic_errno = addr->basic_errno;
1726 vaddr->more_errno = addr->more_errno;
1727 vaddr->prop.address_data = addr->prop.address_data;
1728 copyflag(vaddr, addr, af_pass_message);
1729 }
1730 return yield;
1731 }
1732
1733
1734
1735
1736 /**************************************************
1737 * printf that automatically handles TLS if needed *
1738 ***************************************************/
1739
1740 /* This function is used by verify_address() as a substitute for all fprintf()
1741 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1742 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1743 that assumes that we always use the smtp_out FILE* when not using TLS or the
1744 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1745 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1746 fprintf().
1747
1748 Arguments:
1749 f the candidate FILE* to write to
1750 format format string
1751 ... optional arguments
1752
1753 Returns:
1754 nothing
1755 */
1756
1757 static void PRINTF_FUNCTION(2,3)
1758 respond_printf(FILE *f, const char *format, ...)
1759 {
1760 va_list ap;
1761
1762 va_start(ap, format);
1763 if (smtp_out && (f == smtp_out))
1764 smtp_vprintf(format, ap);
1765 else
1766 vfprintf(f, format, ap);
1767 va_end(ap);
1768 }
1769
1770
1771
1772 /*************************************************
1773 * Verify an email address *
1774 *************************************************/
1775
1776 /* This function is used both for verification (-bv and at other times) and
1777 address testing (-bt), which is indicated by address_test_mode being set.
1778
1779 Arguments:
1780 vaddr contains the address to verify; the next field in this block
1781 must be NULL
1782 f if not NULL, write the result to this file
1783 options various option bits:
1784 vopt_fake_sender => this sender verify is not for the real
1785 sender (it was verify=sender=xxxx or an address from a
1786 header line) - rewriting must not change sender_address
1787 vopt_is_recipient => this is a recipient address, otherwise
1788 it's a sender address - this affects qualification and
1789 rewriting and messages from callouts
1790 vopt_qualify => qualify an unqualified address; else error
1791 vopt_expn => called from SMTP EXPN command
1792 vopt_success_on_redirect => when a new address is generated
1793 the verification instantly succeeds
1794
1795 These ones are used by do_callout() -- the options variable
1796 is passed to it.
1797
1798 vopt_callout_fullpm => if postmaster check, do full one
1799 vopt_callout_no_cache => don't use callout cache
1800 vopt_callout_random => do the "random" thing
1801 vopt_callout_recipsender => use real sender for recipient
1802 vopt_callout_recippmaster => use postmaster for recipient
1803
1804 callout if > 0, specifies that callout is required, and gives timeout
1805 for individual commands
1806 callout_overall if > 0, gives overall timeout for the callout function;
1807 if < 0, a default is used (see do_callout())
1808 callout_connect the connection timeout for callouts
1809 se_mailfrom when callout is requested to verify a sender, use this
1810 in MAIL FROM; NULL => ""
1811 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1812 thing and use this as the sender address (may be "")
1813
1814 routed if not NULL, set TRUE if routing succeeded, so we can
1815 distinguish between routing failed and callout failed
1816
1817 Returns: OK address verified
1818 FAIL address failed to verify
1819 DEFER can't tell at present
1820 */
1821
1822 int
1823 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1824 int callout_overall, int callout_connect, uschar *se_mailfrom,
1825 uschar *pm_mailfrom, BOOL *routed)
1826 {
1827 BOOL allok = TRUE;
1828 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1829 BOOL expn = (options & vopt_expn) != 0;
1830 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1831 int i;
1832 int yield = OK;
1833 int verify_type = expn? v_expn :
1834 address_test_mode? v_none :
1835 options & vopt_is_recipient? v_recipient : v_sender;
1836 address_item *addr_list;
1837 address_item *addr_new = NULL;
1838 address_item *addr_remote = NULL;
1839 address_item *addr_local = NULL;
1840 address_item *addr_succeed = NULL;
1841 uschar **failure_ptr = options & vopt_is_recipient
1842 ? &recipient_verify_failure : &sender_verify_failure;
1843 uschar *ko_prefix, *cr;
1844 uschar *address = vaddr->address;
1845 uschar *save_sender;
1846 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1847
1848 /* Clear, just in case */
1849
1850 *failure_ptr = NULL;
1851
1852 /* Set up a prefix and suffix for error message which allow us to use the same
1853 output statements both in EXPN mode (where an SMTP response is needed) and when
1854 debugging with an output file. */
1855
1856 if (expn)
1857 {
1858 ko_prefix = US"553 ";
1859 cr = US"\r";
1860 }
1861 else ko_prefix = cr = US"";
1862
1863 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1864
1865 if (parse_find_at(address) == NULL)
1866 {
1867 if ((options & vopt_qualify) == 0)
1868 {
1869 if (f != NULL)
1870 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1871 ko_prefix, address, cr);
1872 *failure_ptr = US"qualify";
1873 return FAIL;
1874 }
1875 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1876 }
1877
1878 DEBUG(D_verify)
1879 {
1880 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1881 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1882 }
1883
1884 /* Rewrite and report on it. Clear the domain and local part caches - these
1885 may have been set by domains and local part tests during an ACL. */
1886
1887 if (global_rewrite_rules != NULL)
1888 {
1889 uschar *old = address;
1890 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1891 global_rewrite_rules, rewrite_existflags);
1892 if (address != old)
1893 {
1894 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1895 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1896 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1897 }
1898 }
1899
1900 /* If this is the real sender address, we must update sender_address at
1901 this point, because it may be referred to in the routers. */
1902
1903 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1904 sender_address = address;
1905
1906 /* If the address was rewritten to <> no verification can be done, and we have
1907 to return OK. This rewriting is permitted only for sender addresses; for other
1908 addresses, such rewriting fails. */
1909
1910 if (address[0] == 0) return OK;
1911
1912 /* Flip the legacy TLS-related variables over to the outbound set in case
1913 they're used in the context of a transport used by verification. Reset them
1914 at exit from this routine (so no returns allowed from here on). */
1915
1916 tls_modify_variables(&tls_out);
1917
1918 /* Save a copy of the sender address for re-instating if we change it to <>
1919 while verifying a sender address (a nice bit of self-reference there). */
1920
1921 save_sender = sender_address;
1922
1923 /* Observability variable for router/transport use */
1924
1925 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1926
1927 /* Update the address structure with the possibly qualified and rewritten
1928 address. Set it up as the starting address on the chain of new addresses. */
1929
1930 vaddr->address = address;
1931 addr_new = vaddr;
1932
1933 /* We need a loop, because an address can generate new addresses. We must also
1934 cope with generated pipes and files at the top level. (See also the code and
1935 comment in deliver.c.) However, it is usually the case that the router for
1936 user's .forward files has its verify flag turned off.
1937
1938 If an address generates more than one child, the loop is used only when
1939 full_info is set, and this can only be set locally. Remote enquiries just get
1940 information about the top level address, not anything that it generated. */
1941
1942 while (addr_new)
1943 {
1944 int rc;
1945 address_item *addr = addr_new;
1946
1947 addr_new = addr->next;
1948 addr->next = NULL;
1949
1950 DEBUG(D_verify)
1951 {
1952 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1953 debug_printf("Considering %s\n", addr->address);
1954 }
1955
1956 /* Handle generated pipe, file or reply addresses. We don't get these
1957 when handling EXPN, as it does only one level of expansion. */
1958
1959 if (testflag(addr, af_pfr))
1960 {
1961 allok = FALSE;
1962 if (f != NULL)
1963 {
1964 BOOL allow;
1965
1966 if (addr->address[0] == '>')
1967 {
1968 allow = testflag(addr, af_allow_reply);
1969 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1970 }
1971 else
1972 {
1973 allow = (addr->address[0] == '|')?
1974 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1975 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1976 }
1977
1978 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1979 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1980 "%s\n", addr->message);
1981 else if (allow)
1982 fprintf(f, "\n transport = %s\n", addr->transport->name);
1983 else
1984 fprintf(f, " *** forbidden ***\n");
1985 }
1986 continue;
1987 }
1988
1989 /* Just in case some router parameter refers to it. */
1990
1991 return_path = addr->prop.errors_address
1992 ? addr->prop.errors_address : sender_address;
1993
1994 /* Split the address into domain and local part, handling the %-hack if
1995 necessary, and then route it. While routing a sender address, set
1996 $sender_address to <> because that is what it will be if we were trying to
1997 send a bounce to the sender. */
1998
1999 if (routed) *routed = FALSE;
2000 if ((rc = deliver_split_address(addr)) == OK)
2001 {
2002 if (!(options & vopt_is_recipient)) sender_address = null_sender;
2003 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
2004 &addr_succeed, verify_type);
2005 sender_address = save_sender; /* Put back the real sender */
2006 }
2007
2008 /* If routing an address succeeded, set the flag that remembers, for use when
2009 an ACL cached a sender verify (in case a callout fails). Then if routing set
2010 up a list of hosts or the transport has a host list, and the callout option
2011 is set, and we aren't in a host checking run, do the callout verification,
2012 and set another flag that notes that a callout happened. */
2013
2014 if (rc == OK)
2015 {
2016 if (routed) *routed = TRUE;
2017 if (callout > 0)
2018 {
2019 transport_instance * tp;
2020 host_item * host_list = addr->host_list;
2021
2022 /* Make up some data for use in the case where there is no remote
2023 transport. */
2024
2025 transport_feedback tf = {
2026 NULL, /* interface (=> any) */
2027 US"smtp", /* port */
2028 US"smtp", /* protocol */
2029 NULL, /* hosts */
2030 US"$smtp_active_hostname", /* helo_data */
2031 FALSE, /* hosts_override */
2032 FALSE, /* hosts_randomize */
2033 FALSE, /* gethostbyname */
2034 TRUE, /* qualify_single */
2035 FALSE /* search_parents */
2036 };
2037
2038 /* If verification yielded a remote transport, we want to use that
2039 transport's options, so as to mimic what would happen if we were really
2040 sending a message to this address. */
2041
2042 if ((tp = addr->transport) && !tp->info->local)
2043 {
2044 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
2045
2046 /* If the transport has hosts and the router does not, or if the
2047 transport is configured to override the router's hosts, we must build a
2048 host list of the transport's hosts, and find the IP addresses */
2049
2050 if (tf.hosts && (!host_list || tf.hosts_override))
2051 {
2052 uschar *s;
2053 const uschar *save_deliver_domain = deliver_domain;
2054 uschar *save_deliver_localpart = deliver_localpart;
2055
2056 host_list = NULL; /* Ignore the router's hosts */
2057
2058 deliver_domain = addr->domain;
2059 deliver_localpart = addr->local_part;
2060 s = expand_string(tf.hosts);
2061 deliver_domain = save_deliver_domain;
2062 deliver_localpart = save_deliver_localpart;
2063
2064 if (!s)
2065 {
2066 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
2067 "\"%s\" in %s transport for callout: %s", tf.hosts,
2068 tp->name, expand_string_message);
2069 }
2070 else
2071 {
2072 int flags;
2073 host_item *host, *nexthost;
2074 host_build_hostlist(&host_list, s, tf.hosts_randomize);
2075
2076 /* Just ignore failures to find a host address. If we don't manage
2077 to find any addresses, the callout will defer. Note that more than
2078 one address may be found for a single host, which will result in
2079 additional host items being inserted into the chain. Hence we must
2080 save the next host first. */
2081
2082 flags = HOST_FIND_BY_A;
2083 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2084 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2085
2086 for (host = host_list; host; host = nexthost)
2087 {
2088 nexthost = host->next;
2089 if (tf.gethostbyname ||
2090 string_is_ip_address(host->name, NULL) != 0)
2091 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
2092 else
2093 {
2094 dnssec_domains * dnssec_domains = NULL;
2095 if (Ustrcmp(tp->driver_name, "smtp") == 0)
2096 {
2097 smtp_transport_options_block * ob =
2098 (smtp_transport_options_block *) tp->options_block;
2099 dnssec_domains = &ob->dnssec;
2100 }
2101
2102 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2103 dnssec_domains, NULL, NULL);
2104 }
2105 }
2106 }
2107 }
2108 }
2109
2110 /* Can only do a callout if we have at least one host! If the callout
2111 fails, it will have set ${sender,recipient}_verify_failure. */
2112
2113 if (host_list)
2114 {
2115 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
2116 if (host_checking && !host_checking_callout)
2117 {
2118 HDEBUG(D_verify)
2119 debug_printf("... callout omitted by default when host testing\n"
2120 "(Use -bhc if you want the callouts to happen.)\n");
2121 }
2122 else
2123 {
2124 #ifdef SUPPORT_TLS
2125 deliver_set_expansions(addr);
2126 #endif
2127 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
2128 callout_connect, options, se_mailfrom, pm_mailfrom);
2129 }
2130 }
2131 else
2132 {
2133 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
2134 "transport provided a host list\n");
2135 }
2136 }
2137 }
2138
2139 /* Otherwise, any failure is a routing failure */
2140
2141 else *failure_ptr = US"route";
2142
2143 /* A router may return REROUTED if it has set up a child address as a result
2144 of a change of domain name (typically from widening). In this case we always
2145 want to continue to verify the new child. */
2146
2147 if (rc == REROUTED) continue;
2148
2149 /* Handle hard failures */
2150
2151 if (rc == FAIL)
2152 {
2153 allok = FALSE;
2154 if (f)
2155 {
2156 address_item *p = addr->parent;
2157
2158 respond_printf(f, "%s%s %s", ko_prefix,
2159 full_info ? addr->address : address,
2160 address_test_mode ? "is undeliverable" : "failed to verify");
2161 if (!expn && admin_user)
2162 {
2163 if (addr->basic_errno > 0)
2164 respond_printf(f, ": %s", strerror(addr->basic_errno));
2165 if (addr->message)
2166 respond_printf(f, ": %s", addr->message);
2167 }
2168
2169 /* Show parents iff doing full info */
2170
2171 if (full_info) while (p)
2172 {
2173 respond_printf(f, "%s\n <-- %s", cr, p->address);
2174 p = p->parent;
2175 }
2176 respond_printf(f, "%s\n", cr);
2177 }
2178 cancel_cutthrough_connection("routing hard fail");
2179
2180 if (!full_info)
2181 {
2182 yield = copy_error(vaddr, addr, FAIL);
2183 goto out;
2184 }
2185 yield = FAIL;
2186 }
2187
2188 /* Soft failure */
2189
2190 else if (rc == DEFER)
2191 {
2192 allok = FALSE;
2193 if (f)
2194 {
2195 address_item *p = addr->parent;
2196 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
2197 full_info? addr->address : address);
2198 if (!expn && admin_user)
2199 {
2200 if (addr->basic_errno > 0)
2201 respond_printf(f, ": %s", strerror(addr->basic_errno));
2202 if (addr->message)
2203 respond_printf(f, ": %s", addr->message);
2204 else if (addr->basic_errno <= 0)
2205 respond_printf(f, ": unknown error");
2206 }
2207
2208 /* Show parents iff doing full info */
2209
2210 if (full_info) while (p)
2211 {
2212 respond_printf(f, "%s\n <-- %s", cr, p->address);
2213 p = p->parent;
2214 }
2215 respond_printf(f, "%s\n", cr);
2216 }
2217 cancel_cutthrough_connection("routing soft fail");
2218
2219 if (!full_info)
2220 {
2221 yield = copy_error(vaddr, addr, DEFER);
2222 goto out;
2223 }
2224 if (yield == OK) yield = DEFER;
2225 }
2226
2227 /* If we are handling EXPN, we do not want to continue to route beyond
2228 the top level (whose address is in "address"). */
2229
2230 else if (expn)
2231 {
2232 uschar *ok_prefix = US"250-";
2233
2234 if (!addr_new)
2235 if (!addr_local && !addr_remote)
2236 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2237 else
2238 respond_printf(f, "250 <%s>\r\n", address);
2239
2240 else do
2241 {
2242 address_item *addr2 = addr_new;
2243 addr_new = addr2->next;
2244 if (!addr_new) ok_prefix = US"250 ";
2245 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2246 } while (addr_new);
2247 yield = OK;
2248 goto out;
2249 }
2250
2251 /* Successful routing other than EXPN. */
2252
2253 else
2254 {
2255 /* Handle successful routing when short info wanted. Otherwise continue for
2256 other (generated) addresses. Short info is the operational case. Full info
2257 can be requested only when debug_selector != 0 and a file is supplied.
2258
2259 There is a conflict between the use of aliasing as an alternate email
2260 address, and as a sort of mailing list. If an alias turns the incoming
2261 address into just one address (e.g. J.Caesar->jc44) you may well want to
2262 carry on verifying the generated address to ensure it is valid when
2263 checking incoming mail. If aliasing generates multiple addresses, you
2264 probably don't want to do this. Exim therefore treats the generation of
2265 just a single new address as a special case, and continues on to verify the
2266 generated address. */
2267
2268 if ( !full_info /* Stop if short info wanted AND */
2269 && ( ( !addr_new /* No new address OR */
2270 || addr_new->next /* More than one new address OR */
2271 || testflag(addr_new, af_pfr) /* New address is pfr */
2272 )
2273 || /* OR */
2274 ( addr_new /* At least one new address AND */
2275 && success_on_redirect /* success_on_redirect is set */
2276 ) )
2277 )
2278 {
2279 if (f) fprintf(f, "%s %s\n",
2280 address, address_test_mode ? "is deliverable" : "verified");
2281
2282 /* If we have carried on to verify a child address, we want the value
2283 of $address_data to be that of the child */
2284
2285 vaddr->prop.address_data = addr->prop.address_data;
2286
2287 /* If stopped because more than one new address, cannot cutthrough */
2288
2289 if (addr_new && addr_new->next)
2290 cancel_cutthrough_connection("multiple addresses from routing");
2291
2292 yield = OK;
2293 goto out;
2294 }
2295 }
2296 } /* Loop for generated addresses */
2297
2298 /* Display the full results of the successful routing, including any generated
2299 addresses. Control gets here only when full_info is set, which requires f not
2300 to be NULL, and this occurs only when a top-level verify is called with the
2301 debugging switch on.
2302
2303 If there are no local and no remote addresses, and there were no pipes, files,
2304 or autoreplies, and there were no errors or deferments, the message is to be
2305 discarded, usually because of the use of :blackhole: in an alias file. */
2306
2307 if (allok && !addr_local && !addr_remote)
2308 {
2309 fprintf(f, "mail to %s is discarded\n", address);
2310 goto out;
2311 }
2312
2313 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2314 while (addr_list)
2315 {
2316 address_item *addr = addr_list;
2317 address_item *p = addr->parent;
2318 transport_instance * tp = addr->transport;
2319
2320 addr_list = addr->next;
2321
2322 fprintf(f, "%s", CS addr->address);
2323 #ifdef EXPERIMENTAL_SRS
2324 if(addr->prop.srs_sender)
2325 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2326 #endif
2327
2328 /* If the address is a duplicate, show something about it. */
2329
2330 if (!testflag(addr, af_pfr))
2331 {
2332 tree_node *tnode;
2333 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2334 fprintf(f, " [duplicate, would not be delivered]");
2335 else tree_add_duplicate(addr->unique, addr);
2336 }
2337
2338 /* Now show its parents */
2339
2340 for (p = addr->parent; p; p = p->parent)
2341 fprintf(f, "\n <-- %s", p->address);
2342 fprintf(f, "\n ");
2343
2344 /* Show router, and transport */
2345
2346 fprintf(f, "router = %s, transport = %s\n",
2347 addr->router->name, tp ? tp->name : US"unset");
2348
2349 /* Show any hosts that are set up by a router unless the transport
2350 is going to override them; fiddle a bit to get a nice format. */
2351
2352 if (addr->host_list && tp && !tp->overrides_hosts)
2353 {
2354 host_item *h;
2355 int maxlen = 0;
2356 int maxaddlen = 0;
2357 for (h = addr->host_list; h; h = h->next)
2358 { /* get max lengths of host names, addrs */
2359 int len = Ustrlen(h->name);
2360 if (len > maxlen) maxlen = len;
2361 len = h->address ? Ustrlen(h->address) : 7;
2362 if (len > maxaddlen) maxaddlen = len;
2363 }
2364 for (h = addr->host_list; h; h = h->next)
2365 {
2366 fprintf(f, " host %-*s ", maxlen, h->name);
2367
2368 if (h->address)
2369 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2370 else if (tp->info->local)
2371 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2372 else
2373 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2374
2375 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2376 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2377 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2378 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2379 fputc('\n', f);
2380 }
2381 }
2382 }
2383
2384 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2385 the -bv or -bt case). */
2386
2387 out:
2388 verify_mode = NULL;
2389 tls_modify_variables(&tls_in);
2390
2391 return yield;
2392 }
2393
2394
2395
2396
2397 /*************************************************
2398 * Check headers for syntax errors *
2399 *************************************************/
2400
2401 /* This function checks those header lines that contain addresses, and verifies
2402 that all the addresses therein are syntactially correct.
2403
2404 Arguments:
2405 msgptr where to put an error message
2406
2407 Returns: OK
2408 FAIL
2409 */
2410
2411 int
2412 verify_check_headers(uschar **msgptr)
2413 {
2414 header_line *h;
2415 uschar *colon, *s;
2416 int yield = OK;
2417
2418 for (h = header_list; h != NULL && yield == OK; h = h->next)
2419 {
2420 if (h->type != htype_from &&
2421 h->type != htype_reply_to &&
2422 h->type != htype_sender &&
2423 h->type != htype_to &&
2424 h->type != htype_cc &&
2425 h->type != htype_bcc)
2426 continue;
2427
2428 colon = Ustrchr(h->text, ':');
2429 s = colon + 1;
2430 while (isspace(*s)) s++;
2431
2432 /* Loop for multiple addresses in the header, enabling group syntax. Note
2433 that we have to reset this after the header has been scanned. */
2434
2435 parse_allow_group = TRUE;
2436
2437 while (*s != 0)
2438 {
2439 uschar *ss = parse_find_address_end(s, FALSE);
2440 uschar *recipient, *errmess;
2441 int terminator = *ss;
2442 int start, end, domain;
2443
2444 /* Temporarily terminate the string at this point, and extract the
2445 operative address within, allowing group syntax. */
2446
2447 *ss = 0;
2448 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2449 *ss = terminator;
2450
2451 /* Permit an unqualified address only if the message is local, or if the
2452 sending host is configured to be permitted to send them. */
2453
2454 if (recipient != NULL && domain == 0)
2455 {
2456 if (h->type == htype_from || h->type == htype_sender)
2457 {
2458 if (!allow_unqualified_sender) recipient = NULL;
2459 }
2460 else
2461 {
2462 if (!allow_unqualified_recipient) recipient = NULL;
2463 }
2464 if (recipient == NULL) errmess = US"unqualified address not permitted";
2465 }
2466
2467 /* It's an error if no address could be extracted, except for the special
2468 case of an empty address. */
2469
2470 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2471 {
2472 uschar *verb = US"is";
2473 uschar *t = ss;
2474 uschar *tt = colon;
2475 int len;
2476
2477 /* Arrange not to include any white space at the end in the
2478 error message or the header name. */
2479
2480 while (t > s && isspace(t[-1])) t--;
2481 while (tt > h->text && isspace(tt[-1])) tt--;
2482
2483 /* Add the address that failed to the error message, since in a
2484 header with very many addresses it is sometimes hard to spot
2485 which one is at fault. However, limit the amount of address to
2486 quote - cases have been seen where, for example, a missing double
2487 quote in a humungous To: header creates an "address" that is longer
2488 than string_sprintf can handle. */
2489
2490 len = t - s;
2491 if (len > 1024)
2492 {
2493 len = 1024;
2494 verb = US"begins";
2495 }
2496
2497 /* deconst cast ok as we're passing a non-const to string_printing() */
2498 *msgptr = US string_printing(
2499 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2500 errmess, tt - h->text, h->text, verb, len, s));
2501
2502 yield = FAIL;
2503 break; /* Out of address loop */
2504 }
2505
2506 /* Advance to the next address */
2507
2508 s = ss + (terminator? 1:0);
2509 while (isspace(*s)) s++;
2510 } /* Next address */
2511
2512 parse_allow_group = FALSE;
2513 parse_found_group = FALSE;
2514 } /* Next header unless yield has been set FALSE */
2515
2516 return yield;
2517 }
2518
2519
2520 /*************************************************
2521 * Check header names for 8-bit characters *
2522 *************************************************/
2523
2524 /* This function checks for invalid charcters in header names. See
2525 RFC 5322, 2.2. and RFC 6532, 3.
2526
2527 Arguments:
2528 msgptr where to put an error message
2529
2530 Returns: OK
2531 FAIL
2532 */
2533
2534 int
2535 verify_check_header_names_ascii(uschar **msgptr)
2536 {
2537 header_line *h;
2538 uschar *colon, *s;
2539
2540 for (h = header_list; h != NULL; h = h->next)
2541 {
2542 colon = Ustrchr(h->text, ':');
2543 for(s = h->text; s < colon; s++)
2544 {
2545 if ((*s < 33) || (*s > 126))
2546 {
2547 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2548 colon - h->text, h->text);
2549 return FAIL;
2550 }
2551 }
2552 }
2553 return OK;
2554 }
2555
2556 /*************************************************
2557 * Check for blind recipients *
2558 *************************************************/
2559
2560 /* This function checks that every (envelope) recipient is mentioned in either
2561 the To: or Cc: header lines, thus detecting blind carbon copies.
2562
2563 There are two ways of scanning that could be used: either scan the header lines
2564 and tick off the recipients, or scan the recipients and check the header lines.
2565 The original proposed patch did the former, but I have chosen to do the latter,
2566 because (a) it requires no memory and (b) will use fewer resources when there
2567 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2568
2569 Arguments: none
2570 Returns: OK if there are no blind recipients
2571 FAIL if there is at least one blind recipient
2572 */
2573
2574 int
2575 verify_check_notblind(void)
2576 {
2577 int i;
2578 for (i = 0; i < recipients_count; i++)
2579 {
2580 header_line *h;
2581 BOOL found = FALSE;
2582 uschar *address = recipients_list[i].address;
2583
2584 for (h = header_list; !found && h != NULL; h = h->next)
2585 {
2586 uschar *colon, *s;
2587
2588 if (h->type != htype_to && h->type != htype_cc) continue;
2589
2590 colon = Ustrchr(h->text, ':');
2591 s = colon + 1;
2592 while (isspace(*s)) s++;
2593
2594 /* Loop for multiple addresses in the header, enabling group syntax. Note
2595 that we have to reset this after the header has been scanned. */
2596
2597 parse_allow_group = TRUE;
2598
2599 while (*s != 0)
2600 {
2601 uschar *ss = parse_find_address_end(s, FALSE);
2602 uschar *recipient,*errmess;
2603 int terminator = *ss;
2604 int start, end, domain;
2605
2606 /* Temporarily terminate the string at this point, and extract the
2607 operative address within, allowing group syntax. */
2608
2609 *ss = 0;
2610 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2611 *ss = terminator;
2612
2613 /* If we found a valid recipient that has a domain, compare it with the
2614 envelope recipient. Local parts are compared case-sensitively, domains
2615 case-insensitively. By comparing from the start with length "domain", we
2616 include the "@" at the end, which ensures that we are comparing the whole
2617 local part of each address. */
2618
2619 if (recipient != NULL && domain != 0)
2620 {
2621 found = Ustrncmp(recipient, address, domain) == 0 &&
2622 strcmpic(recipient + domain, address + domain) == 0;
2623 if (found) break;
2624 }
2625
2626 /* Advance to the next address */
2627
2628 s = ss + (terminator? 1:0);
2629 while (isspace(*s)) s++;
2630 } /* Next address */
2631
2632 parse_allow_group = FALSE;
2633 parse_found_group = FALSE;
2634 } /* Next header (if found is false) */
2635
2636 if (!found) return FAIL;
2637 } /* Next recipient */
2638
2639 return OK;
2640 }
2641
2642
2643
2644 /*************************************************
2645 * Find if verified sender *
2646 *************************************************/
2647
2648 /* Usually, just a single address is verified as the sender of the message.
2649 However, Exim can be made to verify other addresses as well (often related in
2650 some way), and this is useful in some environments. There may therefore be a
2651 chain of such addresses that have previously been tested. This function finds
2652 whether a given address is on the chain.
2653
2654 Arguments: the address to be verified
2655 Returns: pointer to an address item, or NULL
2656 */
2657
2658 address_item *
2659 verify_checked_sender(uschar *sender)
2660 {
2661 address_item *addr;
2662 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2663 if (Ustrcmp(sender, addr->address) == 0) break;
2664 return addr;
2665 }
2666
2667
2668
2669
2670
2671 /*************************************************
2672 * Get valid header address *
2673 *************************************************/
2674
2675 /* Scan the originator headers of the message, looking for an address that
2676 verifies successfully. RFC 822 says:
2677
2678 o The "Sender" field mailbox should be sent notices of
2679 any problems in transport or delivery of the original
2680 messages. If there is no "Sender" field, then the
2681 "From" field mailbox should be used.
2682
2683 o If the "Reply-To" field exists, then the reply should
2684 go to the addresses indicated in that field and not to
2685 the address(es) indicated in the "From" field.
2686
2687 So we check a Sender field if there is one, else a Reply_to field, else a From
2688 field. As some strange messages may have more than one of these fields,
2689 especially if they are resent- fields, check all of them if there is more than
2690 one.
2691
2692 Arguments:
2693 user_msgptr points to where to put a user error message
2694 log_msgptr points to where to put a log error message
2695 callout timeout for callout check (passed to verify_address())
2696 callout_overall overall callout timeout (ditto)
2697 callout_connect connect callout timeout (ditto)
2698 se_mailfrom mailfrom for verify; NULL => ""
2699 pm_mailfrom sender for pm callout check (passed to verify_address())
2700 options callout options (passed to verify_address())
2701 verrno where to put the address basic_errno
2702
2703 If log_msgptr is set to something without setting user_msgptr, the caller
2704 normally uses log_msgptr for both things.
2705
2706 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2707 FAIL is given if no appropriate headers are found
2708 */
2709
2710 int
2711 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2712 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2713 uschar *pm_mailfrom, int options, int *verrno)
2714 {
2715 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2716 BOOL done = FALSE;
2717 int yield = FAIL;
2718 int i;
2719
2720 for (i = 0; i < 3 && !done; i++)
2721 {
2722 header_line *h;
2723 for (h = header_list; h != NULL && !done; h = h->next)
2724 {
2725 int terminator, new_ok;
2726 uschar *s, *ss, *endname;
2727
2728 if (h->type != header_types[i]) continue;
2729 s = endname = Ustrchr(h->text, ':') + 1;
2730
2731 /* Scan the addresses in the header, enabling group syntax. Note that we
2732 have to reset this after the header has been scanned. */
2733
2734 parse_allow_group = TRUE;
2735
2736 while (*s != 0)
2737 {
2738 address_item *vaddr;
2739
2740 while (isspace(*s) || *s == ',') s++;
2741 if (*s == 0) break; /* End of header */
2742
2743 ss = parse_find_address_end(s, FALSE);
2744
2745 /* The terminator is a comma or end of header, but there may be white
2746 space preceding it (including newline for the last address). Move back
2747 past any white space so we can check against any cached envelope sender
2748 address verifications. */
2749
2750 while (isspace(ss[-1])) ss--;
2751 terminator = *ss;
2752 *ss = 0;
2753
2754 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2755 (int)(endname - h->text), h->text, s);
2756
2757 /* See if we have already verified this address as an envelope sender,
2758 and if so, use the previous answer. */
2759
2760 vaddr = verify_checked_sender(s);
2761
2762 if (vaddr != NULL && /* Previously checked */
2763 (callout <= 0 || /* No callout needed; OR */
2764 vaddr->special_action > 256)) /* Callout was done */
2765 {
2766 new_ok = vaddr->special_action & 255;
2767 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2768 *ss = terminator; /* Restore shortened string */
2769 }
2770
2771 /* Otherwise we run the verification now. We must restore the shortened
2772 string before running the verification, so the headers are correct, in
2773 case there is any rewriting. */
2774
2775 else
2776 {
2777 int start, end, domain;
2778 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2779 &domain, FALSE);
2780
2781 *ss = terminator;
2782
2783 /* If we found an empty address, just carry on with the next one, but
2784 kill the message. */
2785
2786 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2787 {
2788 *log_msgptr = NULL;
2789 s = ss;
2790 continue;
2791 }
2792
2793 /* If verification failed because of a syntax error, fail this
2794 function, and ensure that the failing address gets added to the error
2795 message. */
2796
2797 if (address == NULL)
2798 {
2799 new_ok = FAIL;
2800 while (ss > s && isspace(ss[-1])) ss--;
2801 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2802 "scanning for sender: %s in \"%.*s\"",
2803 endname - h->text, h->text, *log_msgptr, ss - s, s);
2804 yield = FAIL;
2805 done = TRUE;
2806 break;
2807 }
2808
2809 /* Else go ahead with the sender verification. But it isn't *the*
2810 sender of the message, so set vopt_fake_sender to stop sender_address
2811 being replaced after rewriting or qualification. */
2812
2813 else
2814 {
2815 vaddr = deliver_make_addr(address, FALSE);
2816 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2817 callout, callout_overall, callout_connect, se_mailfrom,
2818 pm_mailfrom, NULL);
2819 }
2820 }
2821
2822 /* We now have the result, either newly found, or cached. If we are
2823 giving out error details, set a specific user error. This means that the
2824 last of these will be returned to the user if all three fail. We do not
2825 set a log message - the generic one below will be used. */
2826
2827 if (new_ok != OK)
2828 {
2829 *verrno = vaddr->basic_errno;
2830 if (smtp_return_error_details)
2831 {
2832 *user_msgptr = string_sprintf("Rejected after DATA: "
2833 "could not verify \"%.*s\" header address\n%s: %s",
2834 endname - h->text, h->text, vaddr->address, vaddr->message);
2835 }
2836 }
2837
2838 /* Success or defer */
2839
2840 if (new_ok == OK)
2841 {
2842 yield = OK;
2843 done = TRUE;
2844 break;
2845 }
2846
2847 if (new_ok == DEFER) yield = DEFER;
2848
2849 /* Move on to any more addresses in the header */
2850
2851 s = ss;
2852 } /* Next address */
2853
2854 parse_allow_group = FALSE;
2855 parse_found_group = FALSE;
2856 } /* Next header, unless done */
2857 } /* Next header type unless done */
2858
2859 if (yield == FAIL && *log_msgptr == NULL)
2860 *log_msgptr = US"there is no valid sender in any header line";
2861
2862 if (yield == DEFER && *log_msgptr == NULL)
2863 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2864
2865 return yield;
2866 }
2867
2868
2869
2870
2871 /*************************************************
2872 * Get RFC 1413 identification *
2873 *************************************************/
2874
2875 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2876 the timeout is set to zero, then the query is not done. There may also be lists
2877 of hosts and nets which are exempt. To guard against malefactors sending
2878 non-printing characters which could, for example, disrupt a message's headers,
2879 make sure the string consists of printing characters only.
2880
2881 Argument:
2882 port the port to connect to; usually this is IDENT_PORT (113), but when
2883 running in the test harness with -bh a different value is used.
2884
2885 Returns: nothing
2886
2887 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2888 */
2889
2890 void
2891 verify_get_ident(int port)
2892 {
2893 int sock, host_af, qlen;
2894 int received_sender_port, received_interface_port, n;
2895 uschar *p;
2896 uschar buffer[2048];
2897
2898 /* Default is no ident. Check whether we want to do an ident check for this
2899 host. */
2900
2901 sender_ident = NULL;
2902 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2903 return;
2904
2905 DEBUG(D_ident) debug_printf("doing ident callback\n");
2906
2907 /* Set up a connection to the ident port of the remote host. Bind the local end
2908 to the incoming interface address. If the sender host address is an IPv6
2909 address, the incoming interface address will also be IPv6. */
2910
2911 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2912 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2913
2914 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2915 {
2916 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2917 strerror(errno));
2918 goto END_OFF;
2919 }
2920
2921 if (ip_connect(sock, host_af, sender_host_address, port,
2922 rfc1413_query_timeout, TRUE) < 0)
2923 {
2924 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2925 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2926 sender_host_address);
2927 else
2928 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2929 sender_host_address, strerror(errno));
2930 goto END_OFF;
2931 }
2932
2933 /* Construct and send the query. */
2934
2935 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2936 qlen = Ustrlen(buffer);
2937 if (send(sock, buffer, qlen, 0) < 0)
2938 {
2939 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2940 goto END_OFF;
2941 }
2942
2943 /* Read a response line. We put it into the rest of the buffer, using several
2944 recv() calls if necessary. */
2945
2946 p = buffer + qlen;
2947
2948 for (;;)
2949 {
2950 uschar *pp;
2951 int count;
2952 int size = sizeof(buffer) - (p - buffer);
2953
2954 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2955 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2956 if (count <= 0) goto END_OFF; /* Read error or EOF */
2957
2958 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2959 generous, and accept a plain \n terminator as well. The only illegal
2960 character is 0. */
2961
2962 for (pp = p; pp < p + count; pp++)
2963 {
2964 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2965 if (*pp == '\n')
2966 {
2967 if (pp[-1] == '\r') pp--;
2968 *pp = 0;
2969 goto GOT_DATA; /* Break out of both loops */
2970 }
2971 }
2972
2973 /* Reached the end of the data without finding \n. Let the loop continue to
2974 read some more, if there is room. */
2975
2976 p = pp;
2977 }
2978
2979 GOT_DATA:
2980
2981 /* We have received a line of data. Check it carefully. It must start with the
2982 same two port numbers that we sent, followed by data as defined by the RFC. For
2983 example,
2984
2985 12345 , 25 : USERID : UNIX :root
2986
2987 However, the amount of white space may be different to what we sent. In the
2988 "osname" field there may be several sub-fields, comma separated. The data we
2989 actually want to save follows the third colon. Some systems put leading spaces
2990 in it - we discard those. */
2991
2992 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2993 &received_interface_port, &n) != 2 ||
2994 received_sender_port != sender_host_port ||
2995 received_interface_port != interface_port)
2996 goto END_OFF;
2997
2998 p = buffer + qlen + n;
2999 while(isspace(*p)) p++;
3000 if (*p++ != ':') goto END_OFF;
3001 while(isspace(*p)) p++;
3002 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
3003 p += 6;
3004 while(isspace(*p)) p++;
3005 if (*p++ != ':') goto END_OFF;
3006 while (*p != 0 && *p != ':') p++;
3007 if (*p++ == 0) goto END_OFF;
3008 while(isspace(*p)) p++;
3009 if (*p == 0) goto END_OFF;
3010
3011 /* The rest of the line is the data we want. We turn it into printing
3012 characters when we save it, so that it cannot mess up the format of any logging
3013 or Received: lines into which it gets inserted. We keep a maximum of 127
3014 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
3015
3016 sender_ident = US string_printing(string_copyn(p, 127));
3017 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
3018
3019 END_OFF:
3020 (void)close(sock);
3021 return;
3022 }
3023
3024
3025
3026
3027 /*************************************************
3028 * Match host to a single host-list item *
3029 *************************************************/
3030
3031 /* This function compares a host (name or address) against a single item
3032 from a host list. The host name gets looked up if it is needed and is not
3033 already known. The function is called from verify_check_this_host() via
3034 match_check_list(), which is why most of its arguments are in a single block.
3035
3036 Arguments:
3037 arg the argument block (see below)
3038 ss the host-list item
3039 valueptr where to pass back looked up data, or NULL
3040 error for error message when returning ERROR
3041
3042 The block contains:
3043 host_name (a) the host name, or
3044 (b) NULL, implying use sender_host_name and
3045 sender_host_aliases, looking them up if required, or
3046 (c) the empty string, meaning that only IP address matches
3047 are permitted
3048 host_address the host address
3049 host_ipv4 the IPv4 address taken from an IPv6 one
3050
3051 Returns: OK matched
3052 FAIL did not match
3053 DEFER lookup deferred
3054 ERROR (a) failed to find the host name or IP address, or
3055 (b) unknown lookup type specified, or
3056 (c) host name encountered when only IP addresses are
3057 being matched
3058 */
3059
3060 int
3061 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
3062 {
3063 check_host_block *cb = (check_host_block *)arg;
3064 int mlen = -1;
3065 int maskoffset;
3066 BOOL iplookup = FALSE;
3067 BOOL isquery = FALSE;
3068 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
3069 const uschar *t;
3070 uschar *semicolon;
3071 uschar **aliases;
3072
3073 /* Optimize for the special case when the pattern is "*". */
3074
3075 if (*ss == '*' && ss[1] == 0) return OK;
3076
3077 /* If the pattern is empty, it matches only in the case when there is no host -
3078 this can occur in ACL checking for SMTP input using the -bs option. In this
3079 situation, the host address is the empty string. */
3080
3081 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
3082 if (*ss == 0) return FAIL;
3083
3084 /* If the pattern is precisely "@" then match against the primary host name,
3085 provided that host name matching is permitted; if it's "@[]" match against the
3086 local host's IP addresses. */
3087
3088 if (*ss == '@')
3089 {
3090 if (ss[1] == 0)
3091 {
3092 if (isiponly) return ERROR;
3093 ss = primary_hostname;
3094 }
3095 else if (Ustrcmp(ss, "@[]") == 0)
3096 {
3097 ip_address_item *ip;
3098 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
3099 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
3100 return FAIL;
3101 }
3102 }
3103
3104 /* If the pattern is an IP address, optionally followed by a bitmask count, do
3105 a (possibly masked) comparision with the current IP address. */
3106
3107 if (string_is_ip_address(ss, &maskoffset) != 0)
3108 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
3109
3110 /* The pattern is not an IP address. A common error that people make is to omit
3111 one component of an IPv4 address, either by accident, or believing that, for
3112 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,
3113 which it isn't. (Those applications that do accept 1.2.3 as an IP address
3114 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
3115 ancient specification.) To aid in debugging these cases, we give a specific
3116 error if the pattern contains only digits and dots or contains a slash preceded
3117 only by digits and dots (a slash at the start indicates a file name and of
3118 course slashes may be present in lookups, but not preceded only by digits and
3119 dots). */
3120
3121 for (t = ss; isdigit(*t) || *t == '.'; t++);
3122 if (*t == 0 || (*t == '/' && t != ss))
3123 {
3124 *error = US"malformed IPv4 address or address mask";
3125 return ERROR;
3126 }
3127
3128 /* See if there is a semicolon in the pattern */
3129
3130 semicolon = Ustrchr(ss, ';');
3131
3132 /* If we are doing an IP address only match, then all lookups must be IP
3133 address lookups, even if there is no "net-". */
3134
3135 if (isiponly)
3136 {
3137 iplookup = semicolon != NULL;
3138 }
3139
3140 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
3141 a lookup on a masked IP network, in textual form. We obey this code even if we
3142 have already set iplookup, so as to skip over the "net-" prefix and to set the
3143 mask length. The net- stuff really only applies to single-key lookups where the
3144 key is implicit. For query-style lookups the key is specified in the query.
3145 From release 4.30, the use of net- for query style is no longer needed, but we
3146 retain it for backward compatibility. */
3147
3148 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
3149 {
3150 mlen = 0;
3151 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
3152 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
3153 iplookup = (*t++ == '-');
3154 }
3155 else t = ss;
3156
3157 /* Do the IP address lookup if that is indeed what we have */
3158
3159 if (iplookup)
3160 {
3161 int insize;
3162 int search_type;
3163 int incoming[4];
3164 void *handle;
3165 uschar *filename, *key, *result;
3166 uschar buffer[64];
3167
3168 /* Find the search type */
3169
3170 search_type = search_findtype(t, semicolon - t);
3171
3172 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3173 search_error_message);
3174
3175 /* Adjust parameters for the type of lookup. For a query-style lookup, there
3176 is no file name, and the "key" is just the query. For query-style with a file
3177 name, we have to fish the file off the start of the query. For a single-key
3178 lookup, the key is the current IP address, masked appropriately, and
3179 reconverted to text form, with the mask appended. For IPv6 addresses, specify
3180 dot separators instead of colons, except when the lookup type is "iplsearch".
3181 */
3182
3183 if (mac_islookup(search_type, lookup_absfilequery))
3184 {
3185 filename = semicolon + 1;
3186 key = filename;
3187 while (*key != 0 && !isspace(*key)) key++;
3188 filename = string_copyn(filename, key - filename);
3189 while (isspace(*key)) key++;
3190 }
3191 else if (mac_islookup(search_type, lookup_querystyle))
3192 {
3193 filename = NULL;
3194 key = semicolon + 1;
3195 }
3196 else /* Single-key style */
3197 {
3198 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3199 ':' : '.';
3200 insize = host_aton(cb->host_address, incoming);
3201 host_mask(insize, incoming, mlen);
3202 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3203 key = buffer;
3204 filename = semicolon + 1;
3205 }
3206
3207 /* Now do the actual lookup; note that there is no search_close() because
3208 of the caching arrangements. */
3209
3210 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
3211 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
3212
3213 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3214 if (valueptr != NULL) *valueptr = result;
3215 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
3216 }
3217
3218 /* The pattern is not an IP address or network reference of any kind. That is,
3219 it is a host name pattern. If this is an IP only match, there's an error in the
3220 host list. */
3221
3222 if (isiponly)
3223 {
3224 *error = US"cannot match host name in match_ip list";
3225 return ERROR;
3226 }
3227
3228 /* Check the characters of the pattern to see if they comprise only letters,
3229 digits, full stops, and hyphens (the constituents of domain names). Allow
3230 underscores, as they are all too commonly found. Sigh. Also, if
3231 allow_utf8_domains is set, allow top-bit characters. */
3232
3233 for (t = ss; *t != 0; t++)
3234 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3235 (!allow_utf8_domains || *t < 128)) break;
3236
3237 /* If the pattern is a complete domain name, with no fancy characters, look up
3238 its IP address and match against that. Note that a multi-homed host will add
3239 items to the chain. */
3240
3241 if (*t == 0)
3242 {
3243 int rc;
3244 host_item h;
3245 h.next = NULL;
3246 h.name = ss;
3247 h.address = NULL;
3248 h.mx = MX_NONE;
3249
3250 /* Using byname rather than bydns here means we cannot determine dnssec
3251 status. On the other hand it is unclear how that could be either
3252 propagated up or enforced. */
3253
3254 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3255 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3256 {
3257 host_item *hh;
3258 for (hh = &h; hh != NULL; hh = hh->next)
3259 {
3260 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3261 }
3262 return FAIL;
3263 }
3264 if (rc == HOST_FIND_AGAIN) return DEFER;
3265 *error = string_sprintf("failed to find IP address for %s", ss);
3266 return ERROR;
3267 }
3268
3269 /* Almost all subsequent comparisons require the host name, and can be done
3270 using the general string matching function. When this function is called for
3271 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3272 must use sender_host_name and its aliases, looking them up if necessary. */
3273
3274 if (cb->host_name != NULL) /* Explicit host name given */
3275 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3276 valueptr);
3277
3278 /* Host name not given; in principle we need the sender host name and its
3279 aliases. However, for query-style lookups, we do not need the name if the
3280 query does not contain $sender_host_name. From release 4.23, a reference to
3281 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3282 on spec. */
3283
3284 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3285 {
3286 const uschar *affix;
3287 int partial, affixlen, starflags, id;
3288
3289 *semicolon = 0;
3290 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3291 *semicolon=';';
3292
3293 if (id < 0) /* Unknown lookup type */
3294 {
3295 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3296 search_error_message, ss);
3297 return DEFER;
3298 }
3299 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3300 }
3301
3302 if (isquery)
3303 {
3304 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3305 {
3306 case OK: return OK;
3307 case DEFER: return DEFER;
3308 default: return FAIL;
3309 }
3310 }
3311
3312 /* Not a query-style lookup; must ensure the host name is present, and then we
3313 do a check on the name and all its aliases. */
3314
3315 if (sender_host_name == NULL)
3316 {
3317 HDEBUG(D_host_lookup)
3318 debug_printf("sender host name required, to match against %s\n", ss);
3319 if (host_lookup_failed || host_name_lookup() != OK)
3320 {
3321 *error = string_sprintf("failed to find host name for %s",
3322 sender_host_address);;
3323 return ERROR;
3324 }
3325 host_build_sender_fullhost();
3326 }
3327
3328 /* Match on the sender host name, using the general matching function */
3329
3330 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3331 valueptr))
3332 {
3333 case OK: return OK;
3334 case DEFER: return DEFER;
3335 }
3336
3337 /* If there are aliases, try matching on them. */
3338
3339 aliases = sender_host_aliases;
3340 while (*aliases != NULL)
3341 {
3342 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3343 {
3344 case OK: return OK;
3345 case DEFER: return DEFER;
3346 }
3347 }
3348 return FAIL;
3349 }
3350
3351
3352
3353
3354 /*************************************************
3355 * Check a specific host matches a host list *
3356 *************************************************/
3357
3358 /* This function is passed a host list containing items in a number of
3359 different formats and the identity of a host. Its job is to determine whether
3360 the given host is in the set of hosts defined by the list. The host name is
3361 passed as a pointer so that it can be looked up if needed and not already
3362 known. This is commonly the case when called from verify_check_host() to check
3363 an incoming connection. When called from elsewhere the host name should usually
3364 be set.
3365
3366 This function is now just a front end to match_check_list(), which runs common
3367 code for scanning a list. We pass it the check_host() function to perform a
3368 single test.
3369
3370 Arguments:
3371 listptr pointer to the host list
3372 cache_bits pointer to cache for named lists, or NULL
3373 host_name the host name or NULL, implying use sender_host_name and
3374 sender_host_aliases, looking them up if required
3375 host_address the IP address
3376 valueptr if not NULL, data from a lookup is passed back here
3377
3378 Returns: OK if the host is in the defined set
3379 FAIL if the host is not in the defined set,
3380 DEFER if a data lookup deferred (not a host lookup)
3381
3382 If the host name was needed in order to make a comparison, and could not be
3383 determined from the IP address, the result is FAIL unless the item
3384 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3385
3386 int
3387 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3388 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3389 {
3390 int rc;
3391 unsigned int *local_cache_bits = cache_bits;
3392 const uschar *save_host_address = deliver_host_address;
3393 check_host_block cb;
3394 cb.host_name = host_name;
3395 cb.host_address = host_address;
3396
3397 if (valueptr != NULL) *valueptr = NULL;
3398
3399 /* If the host address starts off ::ffff: it is an IPv6 address in
3400 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3401 addresses. */
3402
3403 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3404 host_address + 7 : host_address;
3405
3406 /* During the running of the check, put the IP address into $host_address. In
3407 the case of calls from the smtp transport, it will already be there. However,
3408 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3409 the safe side, any existing setting is preserved, though as I write this
3410 (November 2004) I can't see any cases where it is actually needed. */
3411
3412 deliver_host_address = host_address;
3413 rc = match_check_list(
3414 listptr, /* the list */
3415 0, /* separator character */
3416 &hostlist_anchor, /* anchor pointer */
3417 &local_cache_bits, /* cache pointer */
3418 check_host, /* function for testing */
3419 &cb, /* argument for function */
3420 MCL_HOST, /* type of check */
3421 (host_address == sender_host_address)?
3422 US"host" : host_address, /* text for debugging */
3423 valueptr); /* where to pass back data */
3424 deliver_host_address = save_host_address;
3425 return rc;
3426 }
3427
3428
3429
3430
3431 /*************************************************
3432 * Check the given host item matches a list *
3433 *************************************************/
3434 int
3435 verify_check_given_host(uschar **listptr, host_item *host)
3436 {
3437 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3438 }
3439
3440 /*************************************************
3441 * Check the remote host matches a list *
3442 *************************************************/
3443
3444 /* This is a front end to verify_check_this_host(), created because checking
3445 the remote host is a common occurrence. With luck, a good compiler will spot
3446 the tail recursion and optimize it. If there's no host address, this is
3447 command-line SMTP input - check against an empty string for the address.
3448
3449 Arguments:
3450 listptr pointer to the host list
3451
3452 Returns: the yield of verify_check_this_host(),
3453 i.e. OK, FAIL, or DEFER
3454 */
3455
3456 int
3457 verify_check_host(uschar **listptr)
3458 {
3459 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3460 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3461 }
3462
3463
3464
3465
3466
3467 /*************************************************
3468 * Invert an IP address *
3469 *************************************************/
3470
3471 /* Originally just used for DNS xBL lists, now also used for the
3472 reverse_ip expansion operator.
3473
3474 Arguments:
3475 buffer where to put the answer
3476 address the address to invert
3477 */
3478
3479 void
3480 invert_address(uschar *buffer, uschar *address)
3481 {
3482 int bin[4];
3483 uschar *bptr = buffer;
3484
3485 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3486 to the IPv4 part only. */
3487
3488 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3489
3490 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3491 always 1. */
3492
3493 if (host_aton(address, bin) == 1)
3494 {
3495 int i;
3496 int x = bin[0];
3497 for (i = 0; i < 4; i++)
3498 {
3499 sprintf(CS bptr, "%d.", x & 255);
3500 while (*bptr) bptr++;
3501 x >>= 8;
3502 }
3503 }
3504
3505 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3506 in any DNS black lists, and the format in which they will be looked up is
3507 unknown. This is just a guess. */
3508
3509 #if HAVE_IPV6
3510 else
3511 {
3512 int i, j;
3513 for (j = 3; j >= 0; j--)
3514 {
3515 int x = bin[j];
3516 for (i = 0; i < 8; i++)
3517 {
3518 sprintf(CS bptr, "%x.", x & 15);
3519 while (*bptr) bptr++;
3520 x >>= 4;
3521 }
3522 }
3523 }
3524 #endif
3525
3526 /* Remove trailing period -- this is needed so that both arbitrary
3527 dnsbl keydomains and inverted addresses may be combined with the
3528 same format string, "%s.%s" */
3529
3530 *(--bptr) = 0;
3531 }
3532
3533
3534
3535 /*************************************************
3536 * Perform a single dnsbl lookup *
3537 *************************************************/
3538
3539 /* This function is called from verify_check_dnsbl() below. It is also called
3540 recursively from within itself when domain and domain_txt are different
3541 pointers, in order to get the TXT record from the alternate domain.
3542
3543 Arguments:
3544 domain the outer dnsbl domain
3545 domain_txt alternate domain to lookup TXT record on success; when the
3546 same domain is to be used, domain_txt == domain (that is,
3547 the pointers must be identical, not just the text)
3548 keydomain the current keydomain (for debug message)
3549 prepend subdomain to lookup (like keydomain, but
3550 reversed if IP address)
3551 iplist the list of matching IP addresses, or NULL for "any"
3552 bitmask true if bitmask matching is wanted
3553 match_type condition for 'succeed' result
3554 0 => Any RR in iplist (=)
3555 1 => No RR in iplist (!=)
3556 2 => All RRs in iplist (==)
3557 3 => Some RRs not in iplist (!==)
3558 the two bits are defined as MT_NOT and MT_ALL
3559 defer_return what to return for a defer
3560
3561 Returns: OK if lookup succeeded
3562 FAIL if not
3563 */
3564
3565 static int
3566 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3567 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3568 int defer_return)
3569 {
3570 dns_answer dnsa;
3571 dns_scan dnss;
3572 tree_node *t;
3573 dnsbl_cache_block *cb;
3574 int old_pool = store_pool;
3575 uschar query[256]; /* DNS domain max length */
3576
3577 /* Construct the specific query domainname */
3578
3579 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3580 {
3581 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3582 "(ignored): %s...", query);
3583 return FAIL;
3584 }
3585
3586 /* Look for this query in the cache. */
3587
3588 if ( (t = tree_search(dnsbl_cache, query))
3589 && (cb = t->data.ptr)->expiry > time(NULL)
3590 )
3591
3592 /* Previous lookup was cached */
3593
3594 {
3595 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3596 }
3597
3598 /* If not cached from a previous lookup, we must do a DNS lookup, and
3599 cache the result in permanent memory. */
3600
3601 else
3602 {
3603 uint ttl = 3600;
3604
3605 store_pool = POOL_PERM;
3606
3607 if (t)
3608 {
3609 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3610 }
3611
3612 else
3613 { /* Set up a tree entry to cache the lookup */
3614 t = store_get(sizeof(tree_node) + Ustrlen(query));
3615 Ustrcpy(t->name, query);
3616 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3617 (void)tree_insertnode(&dnsbl_cache, t);
3618 }
3619
3620 /* Do the DNS loopup . */
3621
3622 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3623 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3624 cb->text_set = FALSE;
3625 cb->text = NULL;
3626 cb->rhs = NULL;
3627
3628 /* If the lookup succeeded, cache the RHS address. The code allows for
3629 more than one address - this was for complete generality and the possible
3630 use of A6 records. However, A6 records have been reduced to experimental
3631 status (August 2001) and may die out. So they may never get used at all,
3632 let alone in dnsbl records. However, leave the code here, just in case.
3633
3634 Quite apart from one A6 RR generating multiple addresses, there are DNS
3635 lists that return more than one A record, so we must handle multiple
3636 addresses generated in that way as well.
3637
3638 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3639 or some suitably far-future time if none were found. */
3640
3641 if (cb->rc == DNS_SUCCEED)
3642 {
3643 dns_record *rr;
3644 dns_address **addrp = &(cb->rhs);
3645 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3646 rr;
3647 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3648 {
3649 if (rr->type == T_A)
3650 {
3651 dns_address *da = dns_address_from_rr(&dnsa, rr);
3652 if (da)
3653 {
3654 *addrp = da;
3655 while (da->next != NULL) da = da->next;
3656 addrp = &(da->next);
3657 if (ttl > rr->ttl) ttl = rr->ttl;
3658 }
3659 }
3660 }
3661
3662 /* If we didn't find any A records, change the return code. This can
3663 happen when there is a CNAME record but there are no A records for what
3664 it points to. */
3665
3666 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3667 }
3668
3669 cb->expiry = time(NULL)+ttl;
3670 store_pool = old_pool;
3671 }
3672
3673 /* We now have the result of the DNS lookup, either newly done, or cached
3674 from a previous call. If the lookup succeeded, check against the address
3675 list if there is one. This may be a positive equality list (introduced by
3676 "="), a negative equality list (introduced by "!="), a positive bitmask
3677 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3678
3679 if (cb->rc == DNS_SUCCEED)
3680 {
3681 dns_address *da = NULL;
3682 uschar *addlist = cb->rhs->address;
3683
3684 /* For A and AAAA records, there may be multiple addresses from multiple
3685 records. For A6 records (currently not expected to be used) there may be
3686 multiple addresses from a single record. */
3687
3688 for (da = cb->rhs->next; da != NULL; da = da->next)
3689 addlist = string_sprintf("%s, %s", addlist, da->address);
3690
3691 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3692 query, addlist);
3693
3694 /* Address list check; this can be either for equality, or via a bitmask.
3695 In the latter case, all the bits must match. */
3696
3697 if (iplist != NULL)
3698 {
3699 for (da = cb->rhs; da != NULL; da = da->next)
3700 {
3701 int ipsep = ',';
3702 uschar ip[46];
3703 const uschar *ptr = iplist;
3704 uschar *res;
3705
3706 /* Handle exact matching */
3707
3708 if (!bitmask)
3709 {
3710 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3711 {
3712 if (Ustrcmp(CS da->address, ip) == 0) break;
3713 }
3714 }
3715
3716 /* Handle bitmask matching */
3717
3718 else
3719 {
3720 int address[4];
3721 int mask = 0;
3722
3723 /* At present, all known DNS blocking lists use A records, with
3724 IPv4 addresses on the RHS encoding the information they return. I
3725 wonder if this will linger on as the last vestige of IPv4 when IPv6
3726 is ubiquitous? Anyway, for now we use paranoia code to completely
3727 ignore IPv6 addresses. The default mask is 0, which always matches.
3728 We change this only for IPv4 addresses in the list. */
3729
3730 if (host_aton(da->address, address) == 1) mask = address[0];
3731
3732 /* Scan the returned addresses, skipping any that are IPv6 */
3733
3734 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3735 {
3736 if (host_aton(ip, address) != 1) continue;
3737 if ((address[0] & mask) == address[0]) break;
3738 }
3739 }
3740
3741 /* If either
3742
3743 (a) An IP address in an any ('=') list matched, or
3744 (b) No IP address in an all ('==') list matched
3745
3746 then we're done searching. */
3747
3748 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3749 }
3750
3751 /* If da == NULL, either
3752
3753 (a) No IP address in an any ('=') list matched, or
3754 (b) An IP address in an all ('==') list didn't match
3755
3756 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3757 the list. */
3758
3759 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3760 {
3761 HDEBUG(D_dnsbl)
3762 {
3763 uschar *res = NULL;
3764 switch(match_type)
3765 {
3766 case 0:
3767 res = US"was no match";
3768 break;
3769 case MT_NOT:
3770 res = US"was an exclude match";
3771 break;
3772 case MT_ALL:
3773 res = US"was an IP address that did not match";
3774 break;
3775 case MT_NOT|MT_ALL:
3776 res = US"were no IP addresses that did not match";
3777 break;
3778 }
3779 debug_printf("=> but we are not accepting this block class because\n");
3780 debug_printf("=> there %s for %s%c%s\n",
3781 res,
3782 ((match_type & MT_ALL) == 0)? "" : "=",
3783 bitmask? '&' : '=', iplist);
3784 }
3785 return FAIL;
3786 }
3787 }
3788
3789 /* Either there was no IP list, or the record matched, implying that the
3790 domain is on the list. We now want to find a corresponding TXT record. If an
3791 alternate domain is specified for the TXT record, call this function
3792 recursively to look that up; this has the side effect of re-checking that
3793 there is indeed an A record at the alternate domain. */
3794
3795 if (domain_txt != domain)
3796 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3797 FALSE, match_type, defer_return);
3798
3799 /* If there is no alternate domain, look up a TXT record in the main domain
3800 if it has not previously been cached. */
3801
3802 if (!cb->text_set)
3803 {
3804 cb->text_set = TRUE;
3805 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3806 {
3807 dns_record *rr;
3808 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3809 rr != NULL;
3810 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3811 if (rr->type == T_TXT) break;
3812 if (rr != NULL)
3813 {
3814 int len = (rr->data)[0];
3815 if (len > 511) len = 127;
3816 store_pool = POOL_PERM;
3817 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3818 store_pool = old_pool;
3819 }
3820 }
3821 }
3822
3823 dnslist_value = addlist;
3824 dnslist_text = cb->text;
3825 return OK;
3826 }
3827
3828 /* There was a problem with the DNS lookup */
3829
3830 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3831 {
3832 log_write(L_dnslist_defer, LOG_MAIN,
3833 "DNS list lookup defer (probably timeout) for %s: %s", query,
3834 (defer_return == OK)? US"assumed in list" :
3835 (defer_return == FAIL)? US"assumed not in list" :
3836 US"returned DEFER");
3837 return defer_return;
3838 }
3839
3840 /* No entry was found in the DNS; continue for next domain */
3841
3842 HDEBUG(D_dnsbl)
3843 {
3844 debug_printf("DNS lookup for %s failed\n", query);
3845 debug_printf("=> that means %s is not listed at %s\n",
3846 keydomain, domain);
3847 }
3848
3849 return FAIL;
3850 }
3851
3852
3853
3854
3855 /*************************************************
3856 * Check host against DNS black lists *
3857 *************************************************/
3858
3859 /* This function runs checks against a list of DNS black lists, until one
3860 matches. Each item on the list can be of the form
3861
3862 domain=ip-address/key
3863
3864 The domain is the right-most domain that is used for the query, for example,
3865 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3866 if the DNS lookup returns a matching IP address. Several addresses may be
3867 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3868
3869 If no key is given, what is looked up in the domain is the inverted IP address
3870 of the current client host. If a key is given, it is used to construct the
3871 domain for the lookup. For example:
3872
3873 dsn.rfc-ignorant.org/$sender_address_domain
3874
3875 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3876 then we check for a TXT record for an error message, and if found, save its
3877 value in $dnslist_text. We also cache everything in a tree, to optimize
3878 multiple lookups.
3879
3880 The TXT record is normally looked up in the same domain as the A record, but
3881 when many lists are combined in a single DNS domain, this will not be a very
3882 specific message. It is possible to specify a different domain for looking up
3883 TXT records; this is given before the main domain, comma-separated. For
3884 example:
3885
3886 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3887 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3888
3889 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3890
3891 Note: an address for testing RBL is 192.203.178.39
3892 Note: an address for testing DUL is 192.203.178.4
3893 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3894
3895 Arguments:
3896 where the acl type
3897 listptr the domain/address/data list
3898 log_msgptr log message on error
3899
3900 Returns: OK successful lookup (i.e. the address is on the list), or
3901 lookup deferred after +include_unknown
3902 FAIL name not found, or no data found for the given type, or
3903 lookup deferred after +exclude_unknown (default)
3904 DEFER lookup failure, if +defer_unknown was set
3905 */
3906
3907 int
3908 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3909 {
3910 int sep = 0;
3911 int defer_return = FAIL;
3912 const uschar *list = *listptr;
3913 uschar *domain;
3914 uschar *s;
3915 uschar buffer[1024];
3916 uschar revadd[128]; /* Long enough for IPv6 address */
3917
3918 /* Indicate that the inverted IP address is not yet set up */
3919
3920 revadd[0] = 0;
3921
3922 /* In case this is the first time the DNS resolver is being used. */
3923
3924 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3925
3926 /* Loop through all the domains supplied, until something matches */
3927
3928 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3929 {
3930 int rc;
3931 BOOL bitmask = FALSE;
3932 int match_type = 0;
3933 uschar *domain_txt;
3934 uschar *comma;
3935 uschar *iplist;
3936 uschar *key;
3937
3938 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3939
3940 /* Deal with special values that change the behaviour on defer */
3941
3942 if (domain[0] == '+')
3943 {
3944 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3945 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3946 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3947 else
3948 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3949 domain);
3950 continue;
3951 }
3952
3953 /* See if there's explicit data to be looked up */
3954
3955 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3956
3957 /* See if there's a list of addresses supplied after the domain name. This is
3958 introduced by an = or a & character; if preceded by = we require all matches
3959 and if preceded by ! we invert the result. */
3960
3961 if (!(iplist = Ustrchr(domain, '=')))
3962 {
3963 bitmask = TRUE;
3964 iplist = Ustrchr(domain, '&');
3965 }
3966
3967 if (iplist) /* Found either = or & */
3968 {
3969 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3970 {
3971 match_type |= MT_NOT;
3972 iplist[-1] = 0;
3973 }
3974
3975 *iplist++ = 0; /* Terminate domain, move on */
3976
3977 /* If we found = (bitmask == FALSE), check for == or =& */
3978
3979 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3980 {
3981 bitmask = *iplist++ == '&';
3982 match_type |= MT_ALL;
3983 }
3984 }
3985
3986
3987 /* If there is a comma in the domain, it indicates that a second domain for
3988 looking up TXT records is provided, before the main domain. Otherwise we must
3989 set domain_txt == domain. */
3990
3991 domain_txt = domain;
3992 comma = Ustrchr(domain, ',');
3993 if (comma != NULL)
3994 {
3995 *comma++ = 0;
3996 domain = comma;
3997 }
3998
3999 /* Check that what we have left is a sensible domain name. There is no reason
4000 why these domains should in fact use the same syntax as hosts and email
4001 domains, but in practice they seem to. However, there is little point in
4002 actually causing an error here, because that would no doubt hold up incoming
4003 mail. Instead, I'll just log it. */
4004
4005 for (s = domain; *s != 0; s++)
4006 {
4007 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
4008 {
4009 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
4010 "strange characters - is this right?", domain);
4011 break;
4012 }
4013 }
4014
4015 /* Check the alternate domain if present */
4016
4017 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
4018 {
4019 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
4020 {
4021 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
4022 "strange characters - is this right?", domain_txt);
4023 break;
4024 }
4025 }
4026
4027 /* If there is no key string, construct the query by adding the domain name
4028 onto the inverted host address, and perform a single DNS lookup. */
4029
4030 if (key == NULL)
4031 {
4032 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
4033 {
4034 *log_msgptr = string_sprintf
4035 ("cannot test auto-keyed dnslists condition in %s ACL",
4036 acl_wherenames[where]);
4037 return ERROR;
4038 }
4039 if (sender_host_address == NULL) return FAIL; /* can never match */
4040 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
4041 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
4042 iplist, bitmask, match_type, defer_return);
4043 if (rc == OK)
4044 {
4045 dnslist_domain = string_copy(domain_txt);
4046 dnslist_matched = string_copy(sender_host_address);
4047 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
4048 sender_host_address, dnslist_domain);
4049 }
4050 if (rc != FAIL