6c71d7feb2427fedafb4545cfd51c0f10cd49b46
[exim.git] / src / src / verify.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2017 */
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(int, char, uschar **, int);
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 /* Check the callout cache.
123 Options * pm_mailfrom may be modified by cache partial results.
124
125 Return: TRUE if result found
126 */
127
128 static BOOL
129 cached_callout_lookup(address_item * addr, uschar * address_key,
130 uschar * from_address, int * opt_ptr, uschar ** pm_ptr,
131 int * yield, uschar ** failure_ptr,
132 dbdata_callout_cache * new_domain_record, int * old_domain_res)
133 {
134 int options = *opt_ptr;
135 open_db dbblock;
136 open_db *dbm_file = NULL;
137
138 /* Open the callout cache database, it it exists, for reading only at this
139 stage, unless caching has been disabled. */
140
141 if (options & vopt_callout_no_cache)
142 {
143 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
144 }
145 else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)))
146 {
147 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
148 }
149 else
150 {
151 /* If a cache database is available see if we can avoid the need to do an
152 actual callout by making use of previously-obtained data. */
153
154 dbdata_callout_cache_address * cache_address_record;
155 dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file,
156 addr->domain, US"domain",
157 callout_cache_domain_positive_expire, callout_cache_domain_negative_expire);
158
159 /* If an unexpired cache record was found for this domain, see if the callout
160 process can be short-circuited. */
161
162 if (cache_record)
163 {
164 /* In most cases, if an early command (up to and including MAIL FROM:<>)
165 was rejected, there is no point carrying on. The callout fails. However, if
166 we are doing a recipient verification with use_sender or use_postmaster
167 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
168 will be using a non-empty sender. We have to remember this situation so as
169 not to disturb the cached domain value if this whole verification succeeds
170 (we don't want it turning into "accept"). */
171
172 *old_domain_res = cache_record->result;
173
174 if ( cache_record->result == ccache_reject
175 || *from_address == 0 && cache_record->result == ccache_reject_mfnull)
176 {
177 setflag(addr, af_verify_nsfail);
178 HDEBUG(D_verify)
179 debug_printf("callout cache: domain gave initial rejection, or "
180 "does not accept HELO or MAIL FROM:<>\n");
181 setflag(addr, af_verify_nsfail);
182 addr->user_message = US"(result of an earlier callout reused).";
183 *yield = FAIL;
184 *failure_ptr = US"mail";
185 dbfn_close(dbm_file);
186 return TRUE;
187 }
188
189 /* If a previous check on a "random" local part was accepted, we assume
190 that the server does not do any checking on local parts. There is therefore
191 no point in doing the callout, because it will always be successful. If a
192 random check previously failed, arrange not to do it again, but preserve
193 the data in the new record. If a random check is required but hasn't been
194 done, skip the remaining cache processing. */
195
196 if (options & vopt_callout_random) switch(cache_record->random_result)
197 {
198 case ccache_accept:
199 HDEBUG(D_verify)
200 debug_printf("callout cache: domain accepts random addresses\n");
201 dbfn_close(dbm_file);
202 return TRUE; /* Default yield is OK */
203
204 case ccache_reject:
205 HDEBUG(D_verify)
206 debug_printf("callout cache: domain rejects random addresses\n");
207 *opt_ptr = options & ~vopt_callout_random;
208 new_domain_record->random_result = ccache_reject;
209 new_domain_record->random_stamp = cache_record->random_stamp;
210 break;
211
212 default:
213 HDEBUG(D_verify)
214 debug_printf("callout cache: need to check random address handling "
215 "(not cached or cache expired)\n");
216 dbfn_close(dbm_file);
217 return FALSE;
218 }
219
220 /* If a postmaster check is requested, but there was a previous failure,
221 there is again no point in carrying on. If a postmaster check is required,
222 but has not been done before, we are going to have to do a callout, so skip
223 remaining cache processing. */
224
225 if (*pm_ptr)
226 {
227 if (cache_record->postmaster_result == ccache_reject)
228 {
229 setflag(addr, af_verify_pmfail);
230 HDEBUG(D_verify)
231 debug_printf("callout cache: domain does not accept "
232 "RCPT TO:<postmaster@domain>\n");
233 *yield = FAIL;
234 *failure_ptr = US"postmaster";
235 setflag(addr, af_verify_pmfail);
236 addr->user_message = US"(result of earlier verification reused).";
237 dbfn_close(dbm_file);
238 return TRUE;
239 }
240 if (cache_record->postmaster_result == ccache_unknown)
241 {
242 HDEBUG(D_verify)
243 debug_printf("callout cache: need to check RCPT "
244 "TO:<postmaster@domain> (not cached or cache expired)\n");
245 dbfn_close(dbm_file);
246 return FALSE;
247 }
248
249 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
250 postmaster check if the address itself has to be checked. Also ensure
251 that the value in the cache record is preserved (with its old timestamp).
252 */
253
254 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
255 "TO:<postmaster@domain>\n");
256 *pm_ptr = NULL;
257 new_domain_record->postmaster_result = ccache_accept;
258 new_domain_record->postmaster_stamp = cache_record->postmaster_stamp;
259 }
260 }
261
262 /* We can't give a result based on information about the domain. See if there
263 is an unexpired cache record for this specific address (combined with the
264 sender address if we are doing a recipient callout with a non-empty sender).
265 */
266
267 if (!(cache_address_record = (dbdata_callout_cache_address *)
268 get_callout_cache_record(dbm_file, address_key, US"address",
269 callout_cache_positive_expire, callout_cache_negative_expire)))
270 {
271 dbfn_close(dbm_file);
272 return FALSE;
273 }
274
275 if (cache_address_record->result == ccache_accept)
276 {
277 HDEBUG(D_verify)
278 debug_printf("callout cache: address record is positive\n");
279 }
280 else
281 {
282 HDEBUG(D_verify)
283 debug_printf("callout cache: address record is negative\n");
284 addr->user_message = US"Previous (cached) callout verification failure";
285 *failure_ptr = US"recipient";
286 *yield = FAIL;
287 }
288
289 /* Close the cache database while we actually do the callout for real. */
290
291 dbfn_close(dbm_file);
292 return TRUE;
293 }
294 return FALSE;
295 }
296
297
298 /* Write results to callout cache
299 */
300 static void
301 cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain,
302 int done, dbdata_callout_cache_address * addr_rec, uschar * address_key)
303 {
304 open_db dbblock;
305 open_db *dbm_file = NULL;
306
307 /* If we get here with done == TRUE, a successful callout happened, and yield
308 will be set OK or FAIL according to the response to the RCPT command.
309 Otherwise, we looped through the hosts but couldn't complete the business.
310 However, there may be domain-specific information to cache in both cases.
311
312 The value of the result field in the new_domain record is ccache_unknown if
313 there was an error before or with MAIL FROM:, and errno was not zero,
314 implying some kind of I/O error. We don't want to write the cache in that case.
315 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
316
317 if (dom_rec->result != ccache_unknown)
318 if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)))
319 {
320 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
321 }
322 else
323 {
324 (void)dbfn_write(dbm_file, domain, dom_rec,
325 (int)sizeof(dbdata_callout_cache));
326 HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
327 " result=%d postmaster=%d random=%d\n",
328 domain,
329 dom_rec->result,
330 dom_rec->postmaster_result,
331 dom_rec->random_result);
332 }
333
334 /* If a definite result was obtained for the callout, cache it unless caching
335 is disabled. */
336
337 if (done && addr_rec->result != ccache_unknown)
338 {
339 if (!dbm_file)
340 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
341 if (!dbm_file)
342 {
343 HDEBUG(D_verify) debug_printf("no callout cache available\n");
344 }
345 else
346 {
347 (void)dbfn_write(dbm_file, address_key, addr_rec,
348 (int)sizeof(dbdata_callout_cache_address));
349 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
350 addr_rec->result == ccache_accept ? "positive" : "negative",
351 address_key);
352 }
353 }
354
355 if (dbm_file) dbfn_close(dbm_file);
356 }
357
358
359 /* Cutthrough-multi. If the existing cached cutthrough connection matches
360 the one we would make for a subsequent recipient, use it. Send the RCPT TO
361 and check the result, nonpipelined as it may be wanted immediately for
362 recipient-verification.
363
364 It seems simpler to deal with this case separately from the main callout loop.
365 We will need to remember it has sent, or not, so that rcpt-acl tail code
366 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
367
368 Return: TRUE for a definitive result for the recipient
369 */
370 static int
371 cutthrough_multi(address_item * addr, host_item * host_list,
372 transport_feedback * tf, int * yield)
373 {
374 BOOL done = FALSE;
375 host_item * host;
376
377 if (addr->transport == cutthrough.addr.transport)
378 for (host = host_list; host; host = host->next)
379 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
380 {
381 int host_af;
382 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
383 int port = 25;
384
385 deliver_host = host->name;
386 deliver_host_address = host->address;
387 deliver_host_port = host->port;
388 deliver_domain = addr->domain;
389 transport_name = addr->transport->name;
390
391 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
392
393 if (!smtp_get_interface(tf->interface, host_af, addr, &interface,
394 US"callout") ||
395 !smtp_get_port(tf->port, addr, &port, US"callout"))
396 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
397 addr->message);
398
399 if ( ( interface == cutthrough.interface
400 || ( interface
401 && cutthrough.interface
402 && Ustrcmp(interface, cutthrough.interface) == 0
403 ) )
404 && port == cutthrough.host.port
405 )
406 {
407 uschar * resp = NULL;
408
409 /* Match! Send the RCPT TO, set done from the response */
410 done =
411 smtp_write_command(&ctblock, SCMD_FLUSH, "RCPT TO:<%.1000s>\r\n",
412 transport_rcpt_address(addr,
413 addr->transport->rcpt_include_affixes)) >= 0 &&
414 cutthrough_response(cutthrough.fd, '2', &resp, CUTTHROUGH_DATA_TIMEOUT) == '2';
415
416 /* This would go horribly wrong if a callout fail was ignored by ACL.
417 We punt by abandoning cutthrough on a reject, like the
418 first-rcpt does. */
419
420 if (done)
421 {
422 address_item * na = store_get(sizeof(address_item));
423 *na = cutthrough.addr;
424 cutthrough.addr = *addr;
425 cutthrough.addr.host_used = &cutthrough.host;
426 cutthrough.addr.next = na;
427
428 cutthrough.nrcpt++;
429 }
430 else
431 {
432 cancel_cutthrough_connection(TRUE, US"recipient rejected");
433 if (!resp || errno == ETIMEDOUT)
434 {
435 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
436 }
437 else if (errno == 0)
438 {
439 if (*resp == 0)
440 Ustrcpy(resp, US"connection dropped");
441
442 addr->message =
443 string_sprintf("response to \"%s\" was: %s",
444 big_buffer, string_printing(resp));
445
446 addr->user_message =
447 string_sprintf("Callout verification failed:\n%s", resp);
448
449 /* Hard rejection ends the process */
450
451 if (resp[0] == '5') /* Address rejected */
452 {
453 *yield = FAIL;
454 done = TRUE;
455 }
456 }
457 }
458 }
459 break; /* host_list */
460 }
461 if (!done)
462 cancel_cutthrough_connection(TRUE, US"incompatible connection");
463 return done;
464 }
465
466
467 /*************************************************
468 * Do callout verification for an address *
469 *************************************************/
470
471 /* This function is called from verify_address() when the address has routed to
472 a host list, and a callout has been requested. Callouts are expensive; that is
473 why a cache is used to improve the efficiency.
474
475 Arguments:
476 addr the address that's been routed
477 host_list the list of hosts to try
478 tf the transport feedback block
479
480 ifstring "interface" option from transport, or NULL
481 portstring "port" option from transport, or NULL
482 protocolstring "protocol" option from transport, or NULL
483 callout the per-command callout timeout
484 callout_overall the overall callout timeout (if < 0 use 4*callout)
485 callout_connect the callout connection timeout (if < 0 use callout)
486 options the verification options - these bits are used:
487 vopt_is_recipient => this is a recipient address
488 vopt_callout_no_cache => don't use callout cache
489 vopt_callout_fullpm => if postmaster check, do full one
490 vopt_callout_random => do the "random" thing
491 vopt_callout_recipsender => use real sender for recipient
492 vopt_callout_recippmaster => use postmaster for recipient
493 vopt_callout_hold => lazy close connection
494 se_mailfrom MAIL FROM address for sender verify; NULL => ""
495 pm_mailfrom if non-NULL, do the postmaster check with this sender
496
497 Returns: OK/FAIL/DEFER
498 */
499
500 static int
501 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
502 int callout, int callout_overall, int callout_connect, int options,
503 uschar *se_mailfrom, uschar *pm_mailfrom)
504 {
505 int yield = OK;
506 int old_domain_cache_result = ccache_accept;
507 BOOL done = FALSE;
508 uschar *address_key;
509 uschar *from_address;
510 uschar *random_local_part = NULL;
511 const uschar *save_deliver_domain = deliver_domain;
512 uschar **failure_ptr = options & vopt_is_recipient
513 ? &recipient_verify_failure : &sender_verify_failure;
514 dbdata_callout_cache new_domain_record;
515 dbdata_callout_cache_address new_address_record;
516 time_t callout_start_time;
517
518 new_domain_record.result = ccache_unknown;
519 new_domain_record.postmaster_result = ccache_unknown;
520 new_domain_record.random_result = ccache_unknown;
521
522 memset(&new_address_record, 0, sizeof(new_address_record));
523
524 /* For a recipient callout, the key used for the address cache record must
525 include the sender address if we are using the real sender in the callout,
526 because that may influence the result of the callout. */
527
528 if (options & vopt_is_recipient)
529 if (options & vopt_callout_recipsender)
530 {
531 from_address = sender_address;
532 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
533 if (cutthrough.delivery) options |= vopt_callout_no_cache;
534 }
535 else if (options & vopt_callout_recippmaster)
536 {
537 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
538 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
539 qualify_domain_sender);
540 }
541 else
542 {
543 from_address = US"";
544 address_key = addr->address;
545 }
546
547 /* For a sender callout, we must adjust the key if the mailfrom address is not
548 empty. */
549
550 else
551 {
552 from_address = se_mailfrom ? se_mailfrom : US"";
553 address_key = *from_address
554 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
555 }
556
557 if (cached_callout_lookup(addr, address_key, from_address,
558 &options, &pm_mailfrom, &yield, failure_ptr,
559 &new_domain_record, &old_domain_cache_result))
560 {
561 cancel_cutthrough_connection(TRUE, US"cache-hit");
562 goto END_CALLOUT;
563 }
564
565 if (!addr->transport)
566 {
567 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
568 }
569 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
570 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
571 addr->transport->name, addr->transport->driver_name);
572 else
573 {
574 smtp_transport_options_block *ob =
575 (smtp_transport_options_block *)addr->transport->options_block;
576 host_item * host;
577
578 /* The information wasn't available in the cache, so we have to do a real
579 callout and save the result in the cache for next time, unless no_cache is set,
580 or unless we have a previously cached negative random result. If we are to test
581 with a random local part, ensure that such a local part is available. If not,
582 log the fact, but carry on without randomising. */
583
584 if (options & vopt_callout_random && callout_random_local_part)
585 if (!(random_local_part = expand_string(callout_random_local_part)))
586 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
587 "callout_random_local_part: %s", expand_string_message);
588
589 /* Default the connect and overall callout timeouts if not set, and record the
590 time we are starting so that we can enforce it. */
591
592 if (callout_overall < 0) callout_overall = 4 * callout;
593 if (callout_connect < 0) callout_connect = callout;
594 callout_start_time = time(NULL);
595
596 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
597 output because a callout might take some time. When PIPELINING is active and
598 there are many recipients, the total time for doing lots of callouts can add up
599 and cause the client to time out. So in this case we forgo the PIPELINING
600 optimization. */
601
602 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
603
604 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
605 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
606
607 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
608 and we are holding a cutthrough conn open, we can just append the rcpt to
609 that conn for verification purposes (and later delivery also). Simplest
610 coding means skipping this whole loop and doing the append separately. */
611
612 /* Can we re-use an open cutthrough connection? */
613 if ( cutthrough.fd >= 0
614 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
615 == vopt_callout_recipsender
616 && !random_local_part
617 && !pm_mailfrom
618 )
619 done = cutthrough_multi(addr, host_list, tf, &yield);
620
621 /* If we did not use a cached connection, make connections to the hosts
622 and do real callouts. The list of hosts is passed in as an argument. */
623
624 for (host = host_list; host && !done; host = host->next)
625 {
626 int host_af;
627 int port = 25;
628 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
629 smtp_context sx;
630
631 if (!host->address)
632 {
633 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
634 host->name);
635 continue;
636 }
637
638 /* Check the overall callout timeout */
639
640 if (time(NULL) - callout_start_time >= callout_overall)
641 {
642 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
643 break;
644 }
645
646 /* Set IPv4 or IPv6 */
647
648 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
649
650 /* Expand and interpret the interface and port strings. The latter will not
651 be used if there is a host-specific port (e.g. from a manualroute router).
652 This has to be delayed till now, because they may expand differently for
653 different hosts. If there's a failure, log it, but carry on with the
654 defaults. */
655
656 deliver_host = host->name;
657 deliver_host_address = host->address;
658 deliver_host_port = host->port;
659 deliver_domain = addr->domain;
660 transport_name = addr->transport->name;
661
662 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
663 US"callout")
664 || !smtp_get_port(tf->port, addr, &port, US"callout")
665 )
666 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
667 addr->message);
668
669 sx.addrlist = addr;
670 sx.host = host;
671 sx.host_af = host_af,
672 sx.port = port;
673 sx.interface = interface;
674 sx.helo_data = tf->helo_data;
675 sx.tblock = addr->transport;
676 sx.verify = TRUE;
677
678 tls_retry_connection:
679 /* Set the address state so that errors are recorded in it */
680
681 addr->transport_return = PENDING_DEFER;
682 ob->connect_timeout = callout_connect;
683 ob->command_timeout = callout;
684
685 /* Get the channel set up ready for a message (MAIL FROM being the next
686 SMTP command to send. If we tried TLS but it failed, try again without
687 if permitted */
688
689 yield = smtp_setup_conn(&sx, FALSE);
690 #ifdef SUPPORT_TLS
691 if ( yield == DEFER
692 && addr->basic_errno == ERRNO_TLSFAILURE
693 && ob->tls_tempfail_tryclear
694 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
695 )
696 {
697 log_write(0, LOG_MAIN,
698 "%s: callout unencrypted to %s [%s] (not in hosts_require_tls)",
699 addr->message, host->name, host->address);
700 addr->transport_return = PENDING_DEFER;
701 yield = smtp_setup_conn(&sx, TRUE);
702 }
703 #endif
704 if (yield != OK)
705 {
706 errno = addr->basic_errno;
707 transport_name = NULL;
708 deliver_host = deliver_host_address = NULL;
709 deliver_domain = save_deliver_domain;
710
711 /* Failure to accept HELO is cached; this blocks the whole domain for all
712 senders. I/O errors and defer responses are not cached. */
713
714 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
715 {
716 setflag(addr, af_verify_nsfail);
717 new_domain_record.result = ccache_reject;
718 done = TRUE;
719 }
720 else
721 done = FALSE;
722 goto no_conn;
723 }
724
725 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
726 the AUTH info for logging */
727
728 addr->authenticator = client_authenticator;
729 addr->auth_id = client_authenticated_id;
730
731 sx.from_addr = from_address;
732 sx.first_addr = sx.sync_addr = addr;
733 sx.ok = FALSE; /*XXX these 3 last might not be needed for verify? */
734 sx.send_rset = TRUE;
735 sx.completed_addr = FALSE;
736
737 new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull
738 ? ccache_reject_mfnull : ccache_accept;
739
740 /* Do the random local part check first. Temporarily replace the recipient
741 with the "random" value */
742
743 if (random_local_part)
744 {
745 uschar * main_address = addr->address;
746 const uschar * rcpt_domain = addr->domain;
747
748 #ifdef SUPPORT_I18N
749 uschar * errstr = NULL;
750 if ( testflag(addr, af_utf8_downcvt)
751 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
752 &errstr), errstr)
753 )
754 {
755 addr->message = errstr;
756 errno = ERRNO_EXPANDFAIL;
757 setflag(addr, af_verify_nsfail);
758 done = FALSE;
759 rcpt_domain = US""; /*XXX errorhandling! */
760 }
761 #endif
762
763 /* This would be ok for 1st rcpt of a cutthrough (the case handled here;
764 subsequents are done in cutthrough_multi()), but no way to
765 handle a subsequent because of the RSET vaporising the MAIL FROM.
766 So refuse to support any. Most cutthrough use will not involve
767 random_local_part, so no loss. */
768 cancel_cutthrough_connection(TRUE, US"random-recipient");
769
770 addr->address = string_sprintf("%s@%.1000s",
771 random_local_part, rcpt_domain);
772 done = FALSE;
773
774 /* If accepted, we aren't going to do any further tests below.
775 Otherwise, cache a real negative response, and get back to the right
776 state to send RCPT. Unless there's some problem such as a dropped
777 connection, we expect to succeed, because the commands succeeded above.
778 However, some servers drop the connection after responding to an
779 invalid recipient, so on (any) error we drop and remake the connection.
780 XXX We don't care about that for postmaster_full. Should we?
781
782 XXX could we add another flag to the context, and have the common
783 code emit the RSET too? Even pipelined after the RCPT...
784 Then the main-verify call could use it if there's to be a subsequent
785 postmaster-verify.
786 The sync_responses() would need to be taught about it and we'd
787 need another return code filtering out to here.
788
789 Avoid using a SIZE option on the MAIL for all randon-rcpt checks.
790 */
791
792 sx.avoid_option = OPTION_SIZE;
793
794 /* Remember when we last did a random test */
795 new_domain_record.random_stamp = time(NULL);
796
797 if (smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0)
798 switch(addr->transport_return)
799 {
800 case PENDING_OK:
801 new_domain_record.random_result = ccache_accept;
802 yield = OK; /* Only usable result we can return */
803 done = TRUE;
804 goto no_conn;
805 case FAIL: /* the preferred result */
806 new_domain_record.random_result = ccache_reject;
807 sx.avoid_option = 0;
808
809 /* Between each check, issue RSET, because some servers accept only
810 one recipient after MAIL FROM:<>.
811 XXX We don't care about that for postmaster_full. Should we? */
812
813 if ((done =
814 smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0 &&
815 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
816 '2', callout)))
817 break;
818
819 HDEBUG(D_acl|D_v)
820 debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
821 random_local_part = NULL;
822 #ifdef SUPPORT_TLS
823 tls_close(FALSE, TRUE);
824 #endif
825 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
826 (void)close(sx.inblock.sock);
827 sx.inblock.sock = sx.outblock.sock = -1;
828 #ifndef DISABLE_EVENT
829 (void) event_raise(addr->transport->event_action,
830 US"tcp:close", NULL);
831 #endif
832 addr->address = main_address;
833 addr->transport_return = PENDING_DEFER;
834 sx.first_addr = sx.sync_addr = addr;
835 sx.ok = FALSE;
836 sx.send_rset = TRUE;
837 sx.completed_addr = FALSE;
838 goto tls_retry_connection;
839 }
840
841 /* Re-setup for main verify, or for the error message when failing */
842 addr->address = main_address;
843 addr->transport_return = PENDING_DEFER;
844 sx.first_addr = sx.sync_addr = addr;
845 sx.ok = FALSE;
846 sx.send_rset = TRUE;
847 sx.completed_addr = FALSE;
848 }
849 else
850 done = TRUE;
851
852 /* Main verify. For rcpt-verify use SIZE if we know it and we're not cacheing;
853 for sndr-verify never use it. */
854
855 if (done)
856 {
857 if (!(options & vopt_is_recipient && options & vopt_callout_no_cache))
858 sx.avoid_option = OPTION_SIZE;
859
860 done = FALSE;
861 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
862 {
863 case 0: switch(addr->transport_return) /* ok so far */
864 {
865 case PENDING_OK: done = TRUE;
866 new_address_record.result = ccache_accept;
867 break;
868 case FAIL: done = TRUE;
869 yield = FAIL;
870 *failure_ptr = US"recipient";
871 new_address_record.result = ccache_reject;
872 break;
873 default: break;
874 }
875 break;
876
877 case -1: /* MAIL response error */
878 *failure_ptr = US"mail";
879 if (errno == 0 && sx.buffer[0] == '5')
880 {
881 setflag(addr, af_verify_nsfail);
882 if (from_address[0] == 0)
883 new_domain_record.result = ccache_reject_mfnull;
884 }
885 break;
886 /* non-MAIL read i/o error */
887 /* non-MAIL response timeout */
888 /* internal error; channel still usable */
889 default: break; /* transmit failed */
890 }
891 }
892
893 addr->auth_sndr = client_authenticated_sender;
894
895 deliver_host = deliver_host_address = NULL;
896 deliver_domain = save_deliver_domain;
897
898 /* Do postmaster check if requested; if a full check is required, we
899 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
900
901 if (done && pm_mailfrom)
902 {
903 /* Could possibly shift before main verify, just above, and be ok
904 for cutthrough. But no way to handle a subsequent rcpt, so just
905 refuse any */
906 cancel_cutthrough_connection(TRUE, US"postmaster verify");
907 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
908
909 done = smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0
910 && smtp_read_response(&sx.inblock, sx.buffer,
911 sizeof(sx.buffer), '2', callout);
912
913 if (done)
914 {
915 uschar * main_address = addr->address;
916
917 /*XXX oops, affixes */
918 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
919 addr->transport_return = PENDING_DEFER;
920
921 sx.from_addr = pm_mailfrom;
922 sx.first_addr = sx.sync_addr = addr;
923 sx.ok = FALSE;
924 sx.send_rset = TRUE;
925 sx.completed_addr = FALSE;
926 sx.avoid_option = OPTION_SIZE;
927
928 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
929 && addr->transport_return == PENDING_OK
930 )
931 done = TRUE;
932 else
933 done = (options & vopt_callout_fullpm) != 0
934 && smtp_write_command(&sx.outblock, SCMD_FLUSH,
935 "RCPT TO:<postmaster>\r\n") >= 0
936 && smtp_read_response(&sx.inblock, sx.buffer,
937 sizeof(sx.buffer), '2', callout);
938
939 /* Sort out the cache record */
940
941 new_domain_record.postmaster_stamp = time(NULL);
942
943 if (done)
944 new_domain_record.postmaster_result = ccache_accept;
945 else if (errno == 0 && sx.buffer[0] == '5')
946 {
947 *failure_ptr = US"postmaster";
948 setflag(addr, af_verify_pmfail);
949 new_domain_record.postmaster_result = ccache_reject;
950 }
951
952 addr->address = main_address;
953 }
954 }
955 /* For any failure of the main check, other than a negative response, we just
956 close the connection and carry on. We can identify a negative response by the
957 fact that errno is zero. For I/O errors it will be non-zero
958
959 Set up different error texts for logging and for sending back to the caller
960 as an SMTP response. Log in all cases, using a one-line format. For sender
961 callouts, give a full response to the caller, but for recipient callouts,
962 don't give the IP address because this may be an internal host whose identity
963 is not to be widely broadcast. */
964
965 no_conn:
966 switch(errno)
967 {
968 case ETIMEDOUT:
969 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
970 sx.send_quit = FALSE;
971 break;
972
973 #ifdef SUPPORT_I18N
974 case ERRNO_UTF8_FWD:
975 {
976 extern int acl_where; /* src/acl.c */
977 errno = 0;
978 addr->message = string_sprintf(
979 "response to \"EHLO\" did not include SMTPUTF8");
980 addr->user_message = acl_where == ACL_WHERE_RCPT
981 ? US"533 no support for internationalised mailbox name"
982 : US"550 mailbox unavailable";
983 yield = FAIL;
984 done = TRUE;
985 }
986 break;
987 #endif
988 case ECONNREFUSED:
989 sx.send_quit = FALSE;
990 break;
991
992 case 0:
993 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
994
995 /*XXX test here is ugly; seem to have a split of responsibility for
996 building this message. Need to reationalise. Where is it done
997 before here, and when not?
998 Not == 5xx resp to MAIL on main-verify
999 */
1000 if (!addr->message) addr->message =
1001 string_sprintf("response to \"%s\" was: %s",
1002 big_buffer, string_printing(sx.buffer));
1003
1004 addr->user_message = options & vopt_is_recipient
1005 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
1006 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1007 host->address, big_buffer, sx.buffer);
1008
1009 /* Hard rejection ends the process */
1010
1011 if (sx.buffer[0] == '5') /* Address rejected */
1012 {
1013 yield = FAIL;
1014 done = TRUE;
1015 }
1016 break;
1017 }
1018
1019 /* End the SMTP conversation and close the connection. */
1020
1021 /* Cutthrough - on a successful connect and recipient-verify with
1022 use-sender and we are 1st rcpt and have no cutthrough conn so far
1023 here is where we want to leave the conn open. Ditto for a lazy-close
1024 verify. */
1025
1026 if ( (cutthrough.delivery || options & vopt_callout_hold)
1027 && rcpt_count == 1
1028 && done
1029 && yield == OK
1030 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1031 == vopt_callout_recipsender
1032 && !random_local_part
1033 && !pm_mailfrom
1034 && cutthrough.fd < 0
1035 && !sx.lmtp
1036 )
1037 {
1038 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for %s\n",
1039 cutthrough.delivery
1040 ? "cutthrough delivery" : "potential further verifies and delivery");
1041
1042 cutthrough.callout_hold_only = !cutthrough.delivery;
1043 cutthrough.is_tls = tls_out.active >= 0;
1044 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1045 cutthrough.nrcpt = 1;
1046 cutthrough.transport = addr->transport->name;
1047 cutthrough.interface = interface;
1048 cutthrough.snd_port = sending_port;
1049 cutthrough.peer_options = smtp_peer_options;
1050 cutthrough.host = *host;
1051 {
1052 int oldpool = store_pool;
1053 store_pool = POOL_PERM;
1054 cutthrough.snd_ip = string_copy(sending_ip_address);
1055 cutthrough.host.name = string_copy(host->name);
1056 cutthrough.host.address = string_copy(host->address);
1057 store_pool = oldpool;
1058 }
1059 cutthrough.addr = *addr; /* Save the address_item for later logging */
1060 cutthrough.addr.next = NULL;
1061 cutthrough.addr.host_used = &cutthrough.host;
1062 if (addr->parent)
1063 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1064 *addr->parent;
1065 ctblock.buffer = ctbuffer;
1066 ctblock.buffersize = sizeof(ctbuffer);
1067 ctblock.ptr = ctbuffer;
1068 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1069 ctblock.sock = cutthrough.fd;
1070 }
1071 else
1072 {
1073 /* Ensure no cutthrough on multiple verifies that were incompatible */
1074 if (options & vopt_callout_recipsender)
1075 cancel_cutthrough_connection(TRUE, US"not usable for cutthrough");
1076 if (sx.send_quit)
1077 {
1078 (void) smtp_write_command(&sx.outblock, SCMD_FLUSH, "QUIT\r\n");
1079
1080 /* Wait a short time for response, and discard it */
1081 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1082 '2', 1);
1083 }
1084
1085 if (sx.inblock.sock >= 0)
1086 {
1087 #ifdef SUPPORT_TLS
1088 tls_close(FALSE, TRUE);
1089 #endif
1090 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1091 (void)close(sx.inblock.sock);
1092 sx.inblock.sock = sx.outblock.sock = -1;
1093 #ifndef DISABLE_EVENT
1094 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1095 #endif
1096 }
1097 }
1098
1099 if (!done || yield != OK)
1100 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1101 addr->message);
1102 } /* Loop through all hosts, while !done */
1103 }
1104
1105 /* If we get here with done == TRUE, a successful callout happened, and yield
1106 will be set OK or FAIL according to the response to the RCPT command.
1107 Otherwise, we looped through the hosts but couldn't complete the business.
1108 However, there may be domain-specific information to cache in both cases. */
1109
1110 if (!(options & vopt_callout_no_cache))
1111 cache_callout_write(&new_domain_record, addr->domain,
1112 done, &new_address_record, address_key);
1113
1114 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1115 temporary error. If there was only one host, and a response was received, leave
1116 it alone if supplying details. Otherwise, give a generic response. */
1117
1118 if (!done)
1119 {
1120 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1121 options & vopt_is_recipient ? "recipient" : "sender");
1122 yield = DEFER;
1123
1124 addr->message = host_list->next || !addr->message
1125 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1126
1127 addr->user_message = smtp_return_error_details
1128 ? string_sprintf("%s for <%s>.\n"
1129 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1130 "they may be permanently unreachable from this server. In the latter case,\n%s",
1131 dullmsg, addr->address,
1132 options & vopt_is_recipient
1133 ? "the address will never be accepted."
1134 : "you need to change the address or create an MX record for its domain\n"
1135 "if it is supposed to be generally accessible from the Internet.\n"
1136 "Talk to your mail administrator for details.")
1137 : dullmsg;
1138
1139 /* Force a specific error code */
1140
1141 addr->basic_errno = ERRNO_CALLOUTDEFER;
1142 }
1143
1144 /* Come here from within the cache-reading code on fast-track exit. */
1145
1146 END_CALLOUT:
1147 tls_modify_variables(&tls_in);
1148 return yield;
1149 }
1150
1151
1152
1153 /* Called after recipient-acl to get a cutthrough connection open when
1154 one was requested and a recipient-verify wasn't subsequently done.
1155 */
1156 int
1157 open_cutthrough_connection( address_item * addr )
1158 {
1159 address_item addr2;
1160 int rc;
1161
1162 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1163 /* We must use a copy of the address for verification, because it might
1164 get rewritten. */
1165
1166 addr2 = *addr;
1167 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1168 rcpt_count > 1 ? "more" : "start");
1169 rc = verify_address(&addr2, NULL,
1170 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1171 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1172 NULL, NULL, NULL);
1173 addr->message = addr2.message;
1174 addr->user_message = addr2.user_message;
1175 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1176 return rc;
1177 }
1178
1179
1180
1181 /* Send given number of bytes from the buffer */
1182 static BOOL
1183 cutthrough_send(int n)
1184 {
1185 if(cutthrough.fd < 0)
1186 return TRUE;
1187
1188 if(
1189 #ifdef SUPPORT_TLS
1190 tls_out.active == cutthrough.fd ? tls_write(FALSE, ctblock.buffer, n, FALSE) :
1191 #endif
1192 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1193 )
1194 {
1195 transport_count += n;
1196 ctblock.ptr= ctblock.buffer;
1197 return TRUE;
1198 }
1199
1200 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1201 return FALSE;
1202 }
1203
1204
1205
1206 static BOOL
1207 _cutthrough_puts(uschar * cp, int n)
1208 {
1209 while(n--)
1210 {
1211 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1212 if(!cutthrough_send(ctblock.buffersize))
1213 return FALSE;
1214
1215 *ctblock.ptr++ = *cp++;
1216 }
1217 return TRUE;
1218 }
1219
1220 /* Buffered output of counted data block. Return boolean success */
1221 static BOOL
1222 cutthrough_puts(uschar * cp, int n)
1223 {
1224 if (cutthrough.fd < 0) return TRUE;
1225 if (_cutthrough_puts(cp, n)) return TRUE;
1226 cancel_cutthrough_connection(TRUE, US"transmit failed");
1227 return FALSE;
1228 }
1229
1230 void
1231 cutthrough_data_puts(uschar * cp, int n)
1232 {
1233 if (cutthrough.delivery) (void) cutthrough_puts(cp, n);
1234 return;
1235 }
1236
1237
1238 static BOOL
1239 _cutthrough_flush_send(void)
1240 {
1241 int n = ctblock.ptr - ctblock.buffer;
1242
1243 if(n>0)
1244 if(!cutthrough_send(n))
1245 return FALSE;
1246 return TRUE;
1247 }
1248
1249
1250 /* Send out any bufferred output. Return boolean success. */
1251 BOOL
1252 cutthrough_flush_send(void)
1253 {
1254 if (_cutthrough_flush_send()) return TRUE;
1255 cancel_cutthrough_connection(TRUE, US"transmit failed");
1256 return FALSE;
1257 }
1258
1259
1260 static BOOL
1261 cutthrough_put_nl(void)
1262 {
1263 return cutthrough_puts(US"\r\n", 2);
1264 }
1265
1266
1267 void
1268 cutthrough_data_put_nl(void)
1269 {
1270 cutthrough_data_puts(US"\r\n", 2);
1271 }
1272
1273
1274 /* Get and check response from cutthrough target */
1275 static uschar
1276 cutthrough_response(int fd, char expect, uschar ** copy, int timeout)
1277 {
1278 smtp_inblock inblock;
1279 uschar inbuffer[4096];
1280 uschar responsebuffer[4096];
1281
1282 inblock.buffer = inbuffer;
1283 inblock.buffersize = sizeof(inbuffer);
1284 inblock.ptr = inbuffer;
1285 inblock.ptrend = inbuffer;
1286 inblock.sock = fd;
1287 /* this relies on (inblock.sock == tls_out.active) */
1288 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1289 cancel_cutthrough_connection(TRUE, US"target timeout on read");
1290
1291 if(copy)
1292 {
1293 uschar * cp;
1294 *copy = cp = string_copy(responsebuffer);
1295 /* Trim the trailing end of line */
1296 cp += Ustrlen(responsebuffer);
1297 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1298 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1299 }
1300
1301 return responsebuffer[0];
1302 }
1303
1304
1305 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1306 BOOL
1307 cutthrough_predata(void)
1308 {
1309 if(cutthrough.fd < 0 || cutthrough.callout_hold_only)
1310 return FALSE;
1311
1312 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1313 cutthrough_puts(US"DATA\r\n", 6);
1314 cutthrough_flush_send();
1315
1316 /* Assume nothing buffered. If it was it gets ignored. */
1317 return cutthrough_response(cutthrough.fd, '3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1318 }
1319
1320
1321 /* tctx arg only to match write_chunk() */
1322 static BOOL
1323 cutthrough_write_chunk(transport_ctx * tctx, uschar * s, int len)
1324 {
1325 uschar * s2;
1326 while(s && (s2 = Ustrchr(s, '\n')))
1327 {
1328 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1329 return FALSE;
1330 s = s2+1;
1331 }
1332 return TRUE;
1333 }
1334
1335
1336 /* Buffered send of headers. Return success boolean. */
1337 /* Expands newlines to wire format (CR,NL). */
1338 /* Also sends header-terminating blank line. */
1339 BOOL
1340 cutthrough_headers_send(void)
1341 {
1342 transport_ctx tctx;
1343
1344 if(cutthrough.fd < 0 || cutthrough.callout_hold_only)
1345 return FALSE;
1346
1347 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1348 but having a separate buffered-output function (for now)
1349 */
1350 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1351
1352 tctx.u.fd = cutthrough.fd;
1353 tctx.tblock = cutthrough.addr.transport;
1354 tctx.addr = &cutthrough.addr;
1355 tctx.check_string = US".";
1356 tctx.escape_string = US"..";
1357 /*XXX check under spool_files_wireformat. Might be irrelevant */
1358 tctx.options = topt_use_crlf;
1359
1360 if (!transport_headers_send(&tctx, &cutthrough_write_chunk))
1361 return FALSE;
1362
1363 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1364 return TRUE;
1365 }
1366
1367
1368 static void
1369 close_cutthrough_connection(const uschar * why)
1370 {
1371 int fd = cutthrough.fd;
1372 if(fd >= 0)
1373 {
1374 /* We could be sending this after a bunch of data, but that is ok as
1375 the only way to cancel the transfer in dataphase is to drop the tcp
1376 conn before the final dot.
1377 */
1378 ctblock.ptr = ctbuffer;
1379 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1380 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1381 _cutthrough_flush_send();
1382 cutthrough.fd = -1; /* avoid recursion via read timeout */
1383
1384 /* Wait a short time for response, and discard it */
1385 cutthrough_response(fd, '2', NULL, 1);
1386
1387 #ifdef SUPPORT_TLS
1388 tls_close(FALSE, TRUE);
1389 #endif
1390 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1391 (void)close(fd);
1392 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1393 }
1394 ctblock.ptr = ctbuffer;
1395 }
1396
1397 void
1398 cancel_cutthrough_connection(BOOL close_noncutthrough_verifies, const uschar * why)
1399 {
1400 if (cutthrough.delivery || close_noncutthrough_verifies)
1401 close_cutthrough_connection(why);
1402 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1403 }
1404
1405
1406 void
1407 release_cutthrough_connection(const uschar * why)
1408 {
1409 if (cutthrough.fd < 0) return;
1410 HDEBUG(D_acl) debug_printf_indent("release cutthrough conn: %s\n", why);
1411 cutthrough.fd = -1;
1412 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1413 }
1414
1415
1416
1417
1418 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1419 Log an OK response as a transmission.
1420 Close the connection.
1421 Return smtp response-class digit.
1422 */
1423 uschar *
1424 cutthrough_finaldot(void)
1425 {
1426 uschar res;
1427 address_item * addr;
1428 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1429
1430 /* Assume data finshed with new-line */
1431 if( !cutthrough_puts(US".", 1)
1432 || !cutthrough_put_nl()
1433 || !cutthrough_flush_send()
1434 )
1435 return cutthrough.addr.message;
1436
1437 res = cutthrough_response(cutthrough.fd, '2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1438 for (addr = &cutthrough.addr; addr; addr = addr->next)
1439 {
1440 addr->message = cutthrough.addr.message;
1441 switch(res)
1442 {
1443 case '2':
1444 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1445 close_cutthrough_connection(US"delivered");
1446 break;
1447
1448 case '4':
1449 delivery_log(LOG_MAIN, addr, 0,
1450 US"tmp-reject from cutthrough after DATA:");
1451 break;
1452
1453 case '5':
1454 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1455 US"rejected after DATA:");
1456 break;
1457
1458 default:
1459 break;
1460 }
1461 }
1462 return cutthrough.addr.message;
1463 }
1464
1465
1466
1467 /*************************************************
1468 * Copy error to toplevel address *
1469 *************************************************/
1470
1471 /* This function is used when a verify fails or defers, to ensure that the
1472 failure or defer information is in the original toplevel address. This applies
1473 when an address is redirected to a single new address, and the failure or
1474 deferral happens to the child address.
1475
1476 Arguments:
1477 vaddr the verify address item
1478 addr the final address item
1479 yield FAIL or DEFER
1480
1481 Returns: the value of YIELD
1482 */
1483
1484 static int
1485 copy_error(address_item *vaddr, address_item *addr, int yield)
1486 {
1487 if (addr != vaddr)
1488 {
1489 vaddr->message = addr->message;
1490 vaddr->user_message = addr->user_message;
1491 vaddr->basic_errno = addr->basic_errno;
1492 vaddr->more_errno = addr->more_errno;
1493 vaddr->prop.address_data = addr->prop.address_data;
1494 copyflag(vaddr, addr, af_pass_message);
1495 }
1496 return yield;
1497 }
1498
1499
1500
1501
1502 /**************************************************
1503 * printf that automatically handles TLS if needed *
1504 ***************************************************/
1505
1506 /* This function is used by verify_address() as a substitute for all fprintf()
1507 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1508 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1509 that assumes that we always use the smtp_out FILE* when not using TLS or the
1510 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1511 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1512 fprintf().
1513
1514 Arguments:
1515 f the candidate FILE* to write to
1516 format format string
1517 ... optional arguments
1518
1519 Returns:
1520 nothing
1521 */
1522
1523 static void PRINTF_FUNCTION(2,3)
1524 respond_printf(FILE *f, const char *format, ...)
1525 {
1526 va_list ap;
1527
1528 va_start(ap, format);
1529 if (smtp_out && (f == smtp_out))
1530 smtp_vprintf(format, FALSE, ap);
1531 else
1532 vfprintf(f, format, ap);
1533 va_end(ap);
1534 }
1535
1536
1537
1538 /*************************************************
1539 * Verify an email address *
1540 *************************************************/
1541
1542 /* This function is used both for verification (-bv and at other times) and
1543 address testing (-bt), which is indicated by address_test_mode being set.
1544
1545 Arguments:
1546 vaddr contains the address to verify; the next field in this block
1547 must be NULL
1548 f if not NULL, write the result to this file
1549 options various option bits:
1550 vopt_fake_sender => this sender verify is not for the real
1551 sender (it was verify=sender=xxxx or an address from a
1552 header line) - rewriting must not change sender_address
1553 vopt_is_recipient => this is a recipient address, otherwise
1554 it's a sender address - this affects qualification and
1555 rewriting and messages from callouts
1556 vopt_qualify => qualify an unqualified address; else error
1557 vopt_expn => called from SMTP EXPN command
1558 vopt_success_on_redirect => when a new address is generated
1559 the verification instantly succeeds
1560
1561 These ones are used by do_callout() -- the options variable
1562 is passed to it.
1563
1564 vopt_callout_fullpm => if postmaster check, do full one
1565 vopt_callout_no_cache => don't use callout cache
1566 vopt_callout_random => do the "random" thing
1567 vopt_callout_recipsender => use real sender for recipient
1568 vopt_callout_recippmaster => use postmaster for recipient
1569
1570 callout if > 0, specifies that callout is required, and gives timeout
1571 for individual commands
1572 callout_overall if > 0, gives overall timeout for the callout function;
1573 if < 0, a default is used (see do_callout())
1574 callout_connect the connection timeout for callouts
1575 se_mailfrom when callout is requested to verify a sender, use this
1576 in MAIL FROM; NULL => ""
1577 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1578 thing and use this as the sender address (may be "")
1579
1580 routed if not NULL, set TRUE if routing succeeded, so we can
1581 distinguish between routing failed and callout failed
1582
1583 Returns: OK address verified
1584 FAIL address failed to verify
1585 DEFER can't tell at present
1586 */
1587
1588 int
1589 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1590 int callout_overall, int callout_connect, uschar *se_mailfrom,
1591 uschar *pm_mailfrom, BOOL *routed)
1592 {
1593 BOOL allok = TRUE;
1594 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1595 BOOL expn = (options & vopt_expn) != 0;
1596 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1597 int i;
1598 int yield = OK;
1599 int verify_type = expn? v_expn :
1600 address_test_mode? v_none :
1601 options & vopt_is_recipient? v_recipient : v_sender;
1602 address_item *addr_list;
1603 address_item *addr_new = NULL;
1604 address_item *addr_remote = NULL;
1605 address_item *addr_local = NULL;
1606 address_item *addr_succeed = NULL;
1607 uschar **failure_ptr = options & vopt_is_recipient
1608 ? &recipient_verify_failure : &sender_verify_failure;
1609 uschar *ko_prefix, *cr;
1610 uschar *address = vaddr->address;
1611 uschar *save_sender;
1612 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1613
1614 /* Clear, just in case */
1615
1616 *failure_ptr = NULL;
1617
1618 /* Set up a prefix and suffix for error message which allow us to use the same
1619 output statements both in EXPN mode (where an SMTP response is needed) and when
1620 debugging with an output file. */
1621
1622 if (expn)
1623 {
1624 ko_prefix = US"553 ";
1625 cr = US"\r";
1626 }
1627 else ko_prefix = cr = US"";
1628
1629 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1630
1631 if (parse_find_at(address) == NULL)
1632 {
1633 if ((options & vopt_qualify) == 0)
1634 {
1635 if (f != NULL)
1636 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1637 ko_prefix, address, cr);
1638 *failure_ptr = US"qualify";
1639 return FAIL;
1640 }
1641 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1642 }
1643
1644 DEBUG(D_verify)
1645 {
1646 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1647 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1648 }
1649
1650 /* Rewrite and report on it. Clear the domain and local part caches - these
1651 may have been set by domains and local part tests during an ACL. */
1652
1653 if (global_rewrite_rules != NULL)
1654 {
1655 uschar *old = address;
1656 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1657 global_rewrite_rules, rewrite_existflags);
1658 if (address != old)
1659 {
1660 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1661 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1662 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1663 }
1664 }
1665
1666 /* If this is the real sender address, we must update sender_address at
1667 this point, because it may be referred to in the routers. */
1668
1669 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1670 sender_address = address;
1671
1672 /* If the address was rewritten to <> no verification can be done, and we have
1673 to return OK. This rewriting is permitted only for sender addresses; for other
1674 addresses, such rewriting fails. */
1675
1676 if (address[0] == 0) return OK;
1677
1678 /* Flip the legacy TLS-related variables over to the outbound set in case
1679 they're used in the context of a transport used by verification. Reset them
1680 at exit from this routine (so no returns allowed from here on). */
1681
1682 tls_modify_variables(&tls_out);
1683
1684 /* Save a copy of the sender address for re-instating if we change it to <>
1685 while verifying a sender address (a nice bit of self-reference there). */
1686
1687 save_sender = sender_address;
1688
1689 /* Observability variable for router/transport use */
1690
1691 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1692
1693 /* Update the address structure with the possibly qualified and rewritten
1694 address. Set it up as the starting address on the chain of new addresses. */
1695
1696 vaddr->address = address;
1697 addr_new = vaddr;
1698
1699 /* We need a loop, because an address can generate new addresses. We must also
1700 cope with generated pipes and files at the top level. (See also the code and
1701 comment in deliver.c.) However, it is usually the case that the router for
1702 user's .forward files has its verify flag turned off.
1703
1704 If an address generates more than one child, the loop is used only when
1705 full_info is set, and this can only be set locally. Remote enquiries just get
1706 information about the top level address, not anything that it generated. */
1707
1708 while (addr_new)
1709 {
1710 int rc;
1711 address_item *addr = addr_new;
1712
1713 addr_new = addr->next;
1714 addr->next = NULL;
1715
1716 DEBUG(D_verify)
1717 {
1718 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1719 debug_printf("Considering %s\n", addr->address);
1720 }
1721
1722 /* Handle generated pipe, file or reply addresses. We don't get these
1723 when handling EXPN, as it does only one level of expansion. */
1724
1725 if (testflag(addr, af_pfr))
1726 {
1727 allok = FALSE;
1728 if (f != NULL)
1729 {
1730 BOOL allow;
1731
1732 if (addr->address[0] == '>')
1733 {
1734 allow = testflag(addr, af_allow_reply);
1735 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1736 }
1737 else
1738 {
1739 allow = (addr->address[0] == '|')?
1740 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1741 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1742 }
1743
1744 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1745 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1746 "%s\n", addr->message);
1747 else if (allow)
1748 fprintf(f, "\n transport = %s\n", addr->transport->name);
1749 else
1750 fprintf(f, " *** forbidden ***\n");
1751 }
1752 continue;
1753 }
1754
1755 /* Just in case some router parameter refers to it. */
1756
1757 return_path = addr->prop.errors_address
1758 ? addr->prop.errors_address : sender_address;
1759
1760 /* Split the address into domain and local part, handling the %-hack if
1761 necessary, and then route it. While routing a sender address, set
1762 $sender_address to <> because that is what it will be if we were trying to
1763 send a bounce to the sender. */
1764
1765 if (routed) *routed = FALSE;
1766 if ((rc = deliver_split_address(addr)) == OK)
1767 {
1768 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1769 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1770 &addr_succeed, verify_type);
1771 sender_address = save_sender; /* Put back the real sender */
1772 }
1773
1774 /* If routing an address succeeded, set the flag that remembers, for use when
1775 an ACL cached a sender verify (in case a callout fails). Then if routing set
1776 up a list of hosts or the transport has a host list, and the callout option
1777 is set, and we aren't in a host checking run, do the callout verification,
1778 and set another flag that notes that a callout happened. */
1779
1780 if (rc == OK)
1781 {
1782 if (routed) *routed = TRUE;
1783 if (callout > 0)
1784 {
1785 transport_instance * tp;
1786 host_item * host_list = addr->host_list;
1787
1788 /* Make up some data for use in the case where there is no remote
1789 transport. */
1790
1791 transport_feedback tf = {
1792 NULL, /* interface (=> any) */
1793 US"smtp", /* port */
1794 US"smtp", /* protocol */
1795 NULL, /* hosts */
1796 US"$smtp_active_hostname", /* helo_data */
1797 FALSE, /* hosts_override */
1798 FALSE, /* hosts_randomize */
1799 FALSE, /* gethostbyname */
1800 TRUE, /* qualify_single */
1801 FALSE /* search_parents */
1802 };
1803
1804 /* If verification yielded a remote transport, we want to use that
1805 transport's options, so as to mimic what would happen if we were really
1806 sending a message to this address. */
1807
1808 if ((tp = addr->transport) && !tp->info->local)
1809 {
1810 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1811
1812 /* If the transport has hosts and the router does not, or if the
1813 transport is configured to override the router's hosts, we must build a
1814 host list of the transport's hosts, and find the IP addresses */
1815
1816 if (tf.hosts && (!host_list || tf.hosts_override))
1817 {
1818 uschar *s;
1819 const uschar *save_deliver_domain = deliver_domain;
1820 uschar *save_deliver_localpart = deliver_localpart;
1821
1822 host_list = NULL; /* Ignore the router's hosts */
1823
1824 deliver_domain = addr->domain;
1825 deliver_localpart = addr->local_part;
1826 s = expand_string(tf.hosts);
1827 deliver_domain = save_deliver_domain;
1828 deliver_localpart = save_deliver_localpart;
1829
1830 if (!s)
1831 {
1832 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1833 "\"%s\" in %s transport for callout: %s", tf.hosts,
1834 tp->name, expand_string_message);
1835 }
1836 else
1837 {
1838 int flags;
1839 host_item *host, *nexthost;
1840 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1841
1842 /* Just ignore failures to find a host address. If we don't manage
1843 to find any addresses, the callout will defer. Note that more than
1844 one address may be found for a single host, which will result in
1845 additional host items being inserted into the chain. Hence we must
1846 save the next host first. */
1847
1848 flags = HOST_FIND_BY_A;
1849 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1850 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1851
1852 for (host = host_list; host; host = nexthost)
1853 {
1854 nexthost = host->next;
1855 if (tf.gethostbyname ||
1856 string_is_ip_address(host->name, NULL) != 0)
1857 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1858 else
1859 {
1860 dnssec_domains * dnssec_domains = NULL;
1861 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1862 {
1863 smtp_transport_options_block * ob =
1864 (smtp_transport_options_block *) tp->options_block;
1865 dnssec_domains = &ob->dnssec;
1866 }
1867
1868 (void) host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1869 dnssec_domains, NULL, NULL);
1870 }
1871 }
1872 }
1873 }
1874 }
1875
1876 /* Can only do a callout if we have at least one host! If the callout
1877 fails, it will have set ${sender,recipient}_verify_failure. */
1878
1879 if (host_list)
1880 {
1881 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1882 if (host_checking && !host_checking_callout)
1883 {
1884 HDEBUG(D_verify)
1885 debug_printf("... callout omitted by default when host testing\n"
1886 "(Use -bhc if you want the callouts to happen.)\n");
1887 }
1888 else
1889 {
1890 #ifdef SUPPORT_TLS
1891 deliver_set_expansions(addr);
1892 #endif
1893 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1894 callout_connect, options, se_mailfrom, pm_mailfrom);
1895 }
1896 }
1897 else
1898 {
1899 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1900 "transport provided a host list\n");
1901 }
1902 }
1903 }
1904
1905 /* Otherwise, any failure is a routing failure */
1906
1907 else *failure_ptr = US"route";
1908
1909 /* A router may return REROUTED if it has set up a child address as a result
1910 of a change of domain name (typically from widening). In this case we always
1911 want to continue to verify the new child. */
1912
1913 if (rc == REROUTED) continue;
1914
1915 /* Handle hard failures */
1916
1917 if (rc == FAIL)
1918 {
1919 allok = FALSE;
1920 if (f)
1921 {
1922 address_item *p = addr->parent;
1923
1924 respond_printf(f, "%s%s %s", ko_prefix,
1925 full_info ? addr->address : address,
1926 address_test_mode ? "is undeliverable" : "failed to verify");
1927 if (!expn && admin_user)
1928 {
1929 if (addr->basic_errno > 0)
1930 respond_printf(f, ": %s", strerror(addr->basic_errno));
1931 if (addr->message)
1932 respond_printf(f, ": %s", addr->message);
1933 }
1934
1935 /* Show parents iff doing full info */
1936
1937 if (full_info) while (p)
1938 {
1939 respond_printf(f, "%s\n <-- %s", cr, p->address);
1940 p = p->parent;
1941 }
1942 respond_printf(f, "%s\n", cr);
1943 }
1944 cancel_cutthrough_connection(TRUE, US"routing hard fail");
1945
1946 if (!full_info)
1947 {
1948 yield = copy_error(vaddr, addr, FAIL);
1949 goto out;
1950 }
1951 yield = FAIL;
1952 }
1953
1954 /* Soft failure */
1955
1956 else if (rc == DEFER)
1957 {
1958 allok = FALSE;
1959 if (f)
1960 {
1961 address_item *p = addr->parent;
1962 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1963 full_info? addr->address : address);
1964 if (!expn && admin_user)
1965 {
1966 if (addr->basic_errno > 0)
1967 respond_printf(f, ": %s", strerror(addr->basic_errno));
1968 if (addr->message)
1969 respond_printf(f, ": %s", addr->message);
1970 else if (addr->basic_errno <= 0)
1971 respond_printf(f, ": unknown error");
1972 }
1973
1974 /* Show parents iff doing full info */
1975
1976 if (full_info) while (p)
1977 {
1978 respond_printf(f, "%s\n <-- %s", cr, p->address);
1979 p = p->parent;
1980 }
1981 respond_printf(f, "%s\n", cr);
1982 }
1983 cancel_cutthrough_connection(TRUE, US"routing soft fail");
1984
1985 if (!full_info)
1986 {
1987 yield = copy_error(vaddr, addr, DEFER);
1988 goto out;
1989 }
1990 if (yield == OK) yield = DEFER;
1991 }
1992
1993 /* If we are handling EXPN, we do not want to continue to route beyond
1994 the top level (whose address is in "address"). */
1995
1996 else if (expn)
1997 {
1998 uschar *ok_prefix = US"250-";
1999
2000 if (!addr_new)
2001 if (!addr_local && !addr_remote)
2002 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
2003 else
2004 respond_printf(f, "250 <%s>\r\n", address);
2005
2006 else do
2007 {
2008 address_item *addr2 = addr_new;
2009 addr_new = addr2->next;
2010 if (!addr_new) ok_prefix = US"250 ";
2011 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2012 } while (addr_new);
2013 yield = OK;
2014 goto out;
2015 }
2016
2017 /* Successful routing other than EXPN. */
2018
2019 else
2020 {
2021 /* Handle successful routing when short info wanted. Otherwise continue for
2022 other (generated) addresses. Short info is the operational case. Full info
2023 can be requested only when debug_selector != 0 and a file is supplied.
2024
2025 There is a conflict between the use of aliasing as an alternate email
2026 address, and as a sort of mailing list. If an alias turns the incoming
2027 address into just one address (e.g. J.Caesar->jc44) you may well want to
2028 carry on verifying the generated address to ensure it is valid when
2029 checking incoming mail. If aliasing generates multiple addresses, you
2030 probably don't want to do this. Exim therefore treats the generation of
2031 just a single new address as a special case, and continues on to verify the
2032 generated address. */
2033
2034 if ( !full_info /* Stop if short info wanted AND */
2035 && ( ( !addr_new /* No new address OR */
2036 || addr_new->next /* More than one new address OR */
2037 || testflag(addr_new, af_pfr) /* New address is pfr */
2038 )
2039 || /* OR */
2040 ( addr_new /* At least one new address AND */
2041 && success_on_redirect /* success_on_redirect is set */
2042 ) )
2043 )
2044 {
2045 if (f) fprintf(f, "%s %s\n",
2046 address, address_test_mode ? "is deliverable" : "verified");
2047
2048 /* If we have carried on to verify a child address, we want the value
2049 of $address_data to be that of the child */
2050
2051 vaddr->prop.address_data = addr->prop.address_data;
2052
2053 /* If stopped because more than one new address, cannot cutthrough */
2054
2055 if (addr_new && addr_new->next)
2056 cancel_cutthrough_connection(TRUE, US"multiple addresses from routing");
2057
2058 yield = OK;
2059 goto out;
2060 }
2061 }
2062 } /* Loop for generated addresses */
2063
2064 /* Display the full results of the successful routing, including any generated
2065 addresses. Control gets here only when full_info is set, which requires f not
2066 to be NULL, and this occurs only when a top-level verify is called with the
2067 debugging switch on.
2068
2069 If there are no local and no remote addresses, and there were no pipes, files,
2070 or autoreplies, and there were no errors or deferments, the message is to be
2071 discarded, usually because of the use of :blackhole: in an alias file. */
2072
2073 if (allok && !addr_local && !addr_remote)
2074 {
2075 fprintf(f, "mail to %s is discarded\n", address);
2076 goto out;
2077 }
2078
2079 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2080 while (addr_list)
2081 {
2082 address_item *addr = addr_list;
2083 address_item *p = addr->parent;
2084 transport_instance * tp = addr->transport;
2085
2086 addr_list = addr->next;
2087
2088 fprintf(f, "%s", CS addr->address);
2089 #ifdef EXPERIMENTAL_SRS
2090 if(addr->prop.srs_sender)
2091 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2092 #endif
2093
2094 /* If the address is a duplicate, show something about it. */
2095
2096 if (!testflag(addr, af_pfr))
2097 {
2098 tree_node *tnode;
2099 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2100 fprintf(f, " [duplicate, would not be delivered]");
2101 else tree_add_duplicate(addr->unique, addr);
2102 }
2103
2104 /* Now show its parents */
2105
2106 for (p = addr->parent; p; p = p->parent)
2107 fprintf(f, "\n <-- %s", p->address);
2108 fprintf(f, "\n ");
2109
2110 /* Show router, and transport */
2111
2112 fprintf(f, "router = %s, transport = %s\n",
2113 addr->router->name, tp ? tp->name : US"unset");
2114
2115 /* Show any hosts that are set up by a router unless the transport
2116 is going to override them; fiddle a bit to get a nice format. */
2117
2118 if (addr->host_list && tp && !tp->overrides_hosts)
2119 {
2120 host_item *h;
2121 int maxlen = 0;
2122 int maxaddlen = 0;
2123 for (h = addr->host_list; h; h = h->next)
2124 { /* get max lengths of host names, addrs */
2125 int len = Ustrlen(h->name);
2126 if (len > maxlen) maxlen = len;
2127 len = h->address ? Ustrlen(h->address) : 7;
2128 if (len > maxaddlen) maxaddlen = len;
2129 }
2130 for (h = addr->host_list; h; h = h->next)
2131 {
2132 fprintf(f, " host %-*s ", maxlen, h->name);
2133
2134 if (h->address)
2135 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2136 else if (tp->info->local)
2137 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2138 else
2139 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2140
2141 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2142 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2143 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2144 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2145 fputc('\n', f);
2146 }
2147 }
2148 }
2149
2150 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2151 the -bv or -bt case). */
2152
2153 out:
2154 verify_mode = NULL;
2155 tls_modify_variables(&tls_in);
2156
2157 return yield;
2158 }
2159
2160
2161
2162
2163 /*************************************************
2164 * Check headers for syntax errors *
2165 *************************************************/
2166
2167 /* This function checks those header lines that contain addresses, and verifies
2168 that all the addresses therein are syntactially correct.
2169
2170 Arguments:
2171 msgptr where to put an error message
2172
2173 Returns: OK
2174 FAIL
2175 */
2176
2177 int
2178 verify_check_headers(uschar **msgptr)
2179 {
2180 header_line *h;
2181 uschar *colon, *s;
2182 int yield = OK;
2183
2184 for (h = header_list; h != NULL && yield == OK; h = h->next)
2185 {
2186 if (h->type != htype_from &&
2187 h->type != htype_reply_to &&
2188 h->type != htype_sender &&
2189 h->type != htype_to &&
2190 h->type != htype_cc &&
2191 h->type != htype_bcc)
2192 continue;
2193
2194 colon = Ustrchr(h->text, ':');
2195 s = colon + 1;
2196 while (isspace(*s)) s++;
2197
2198 /* Loop for multiple addresses in the header, enabling group syntax. Note
2199 that we have to reset this after the header has been scanned. */
2200
2201 parse_allow_group = TRUE;
2202
2203 while (*s != 0)
2204 {
2205 uschar *ss = parse_find_address_end(s, FALSE);
2206 uschar *recipient, *errmess;
2207 int terminator = *ss;
2208 int start, end, domain;
2209
2210 /* Temporarily terminate the string at this point, and extract the
2211 operative address within, allowing group syntax. */
2212
2213 *ss = 0;
2214 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2215 *ss = terminator;
2216
2217 /* Permit an unqualified address only if the message is local, or if the
2218 sending host is configured to be permitted to send them. */
2219
2220 if (recipient != NULL && domain == 0)
2221 {
2222 if (h->type == htype_from || h->type == htype_sender)
2223 {
2224 if (!allow_unqualified_sender) recipient = NULL;
2225 }
2226 else
2227 {
2228 if (!allow_unqualified_recipient) recipient = NULL;
2229 }
2230 if (recipient == NULL) errmess = US"unqualified address not permitted";
2231 }
2232
2233 /* It's an error if no address could be extracted, except for the special
2234 case of an empty address. */
2235
2236 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2237 {
2238 uschar *verb = US"is";
2239 uschar *t = ss;
2240 uschar *tt = colon;
2241 int len;
2242
2243 /* Arrange not to include any white space at the end in the
2244 error message or the header name. */
2245
2246 while (t > s && isspace(t[-1])) t--;
2247 while (tt > h->text && isspace(tt[-1])) tt--;
2248
2249 /* Add the address that failed to the error message, since in a
2250 header with very many addresses it is sometimes hard to spot
2251 which one is at fault. However, limit the amount of address to
2252 quote - cases have been seen where, for example, a missing double
2253 quote in a humungous To: header creates an "address" that is longer
2254 than string_sprintf can handle. */
2255
2256 len = t - s;
2257 if (len > 1024)
2258 {
2259 len = 1024;
2260 verb = US"begins";
2261 }
2262
2263 /* deconst cast ok as we're passing a non-const to string_printing() */
2264 *msgptr = US string_printing(
2265 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2266 errmess, tt - h->text, h->text, verb, len, s));
2267
2268 yield = FAIL;
2269 break; /* Out of address loop */
2270 }
2271
2272 /* Advance to the next address */
2273
2274 s = ss + (terminator? 1:0);
2275 while (isspace(*s)) s++;
2276 } /* Next address */
2277
2278 parse_allow_group = FALSE;
2279 parse_found_group = FALSE;
2280 } /* Next header unless yield has been set FALSE */
2281
2282 return yield;
2283 }
2284
2285
2286 /*************************************************
2287 * Check header names for 8-bit characters *
2288 *************************************************/
2289
2290 /* This function checks for invalid characters in header names. See
2291 RFC 5322, 2.2. and RFC 6532, 3.
2292
2293 Arguments:
2294 msgptr where to put an error message
2295
2296 Returns: OK
2297 FAIL
2298 */
2299
2300 int
2301 verify_check_header_names_ascii(uschar **msgptr)
2302 {
2303 header_line *h;
2304 uschar *colon, *s;
2305
2306 for (h = header_list; h; h = h->next)
2307 {
2308 colon = Ustrchr(h->text, ':');
2309 for(s = h->text; s < colon; s++)
2310 if ((*s < 33) || (*s > 126))
2311 {
2312 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2313 colon - h->text, h->text);
2314 return FAIL;
2315 }
2316 }
2317 return OK;
2318 }
2319
2320 /*************************************************
2321 * Check for blind recipients *
2322 *************************************************/
2323
2324 /* This function checks that every (envelope) recipient is mentioned in either
2325 the To: or Cc: header lines, thus detecting blind carbon copies.
2326
2327 There are two ways of scanning that could be used: either scan the header lines
2328 and tick off the recipients, or scan the recipients and check the header lines.
2329 The original proposed patch did the former, but I have chosen to do the latter,
2330 because (a) it requires no memory and (b) will use fewer resources when there
2331 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2332
2333 Arguments: none
2334 Returns: OK if there are no blind recipients
2335 FAIL if there is at least one blind recipient
2336 */
2337
2338 int
2339 verify_check_notblind(void)
2340 {
2341 int i;
2342 for (i = 0; i < recipients_count; i++)
2343 {
2344 header_line *h;
2345 BOOL found = FALSE;
2346 uschar *address = recipients_list[i].address;
2347
2348 for (h = header_list; !found && h != NULL; h = h->next)
2349 {
2350 uschar *colon, *s;
2351
2352 if (h->type != htype_to && h->type != htype_cc) continue;
2353
2354 colon = Ustrchr(h->text, ':');
2355 s = colon + 1;
2356 while (isspace(*s)) s++;
2357
2358 /* Loop for multiple addresses in the header, enabling group syntax. Note
2359 that we have to reset this after the header has been scanned. */
2360
2361 parse_allow_group = TRUE;
2362
2363 while (*s != 0)
2364 {
2365 uschar *ss = parse_find_address_end(s, FALSE);
2366 uschar *recipient,*errmess;
2367 int terminator = *ss;
2368 int start, end, domain;
2369
2370 /* Temporarily terminate the string at this point, and extract the
2371 operative address within, allowing group syntax. */
2372
2373 *ss = 0;
2374 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2375 *ss = terminator;
2376
2377 /* If we found a valid recipient that has a domain, compare it with the
2378 envelope recipient. Local parts are compared case-sensitively, domains
2379 case-insensitively. By comparing from the start with length "domain", we
2380 include the "@" at the end, which ensures that we are comparing the whole
2381 local part of each address. */
2382
2383 if (recipient != NULL && domain != 0)
2384 {
2385 found = Ustrncmp(recipient, address, domain) == 0 &&
2386 strcmpic(recipient + domain, address + domain) == 0;
2387 if (found) break;
2388 }
2389
2390 /* Advance to the next address */
2391
2392 s = ss + (terminator? 1:0);
2393 while (isspace(*s)) s++;
2394 } /* Next address */
2395
2396 parse_allow_group = FALSE;
2397 parse_found_group = FALSE;
2398 } /* Next header (if found is false) */
2399
2400 if (!found) return FAIL;
2401 } /* Next recipient */
2402
2403 return OK;
2404 }
2405
2406
2407
2408 /*************************************************
2409 * Find if verified sender *
2410 *************************************************/
2411
2412 /* Usually, just a single address is verified as the sender of the message.
2413 However, Exim can be made to verify other addresses as well (often related in
2414 some way), and this is useful in some environments. There may therefore be a
2415 chain of such addresses that have previously been tested. This function finds
2416 whether a given address is on the chain.
2417
2418 Arguments: the address to be verified
2419 Returns: pointer to an address item, or NULL
2420 */
2421
2422 address_item *
2423 verify_checked_sender(uschar *sender)
2424 {
2425 address_item *addr;
2426 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2427 if (Ustrcmp(sender, addr->address) == 0) break;
2428 return addr;
2429 }
2430
2431
2432
2433
2434
2435 /*************************************************
2436 * Get valid header address *
2437 *************************************************/
2438
2439 /* Scan the originator headers of the message, looking for an address that
2440 verifies successfully. RFC 822 says:
2441
2442 o The "Sender" field mailbox should be sent notices of
2443 any problems in transport or delivery of the original
2444 messages. If there is no "Sender" field, then the
2445 "From" field mailbox should be used.
2446
2447 o If the "Reply-To" field exists, then the reply should
2448 go to the addresses indicated in that field and not to
2449 the address(es) indicated in the "From" field.
2450
2451 So we check a Sender field if there is one, else a Reply_to field, else a From
2452 field. As some strange messages may have more than one of these fields,
2453 especially if they are resent- fields, check all of them if there is more than
2454 one.
2455
2456 Arguments:
2457 user_msgptr points to where to put a user error message
2458 log_msgptr points to where to put a log error message
2459 callout timeout for callout check (passed to verify_address())
2460 callout_overall overall callout timeout (ditto)
2461 callout_connect connect callout timeout (ditto)
2462 se_mailfrom mailfrom for verify; NULL => ""
2463 pm_mailfrom sender for pm callout check (passed to verify_address())
2464 options callout options (passed to verify_address())
2465 verrno where to put the address basic_errno
2466
2467 If log_msgptr is set to something without setting user_msgptr, the caller
2468 normally uses log_msgptr for both things.
2469
2470 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2471 FAIL is given if no appropriate headers are found
2472 */
2473
2474 int
2475 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2476 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2477 uschar *pm_mailfrom, int options, int *verrno)
2478 {
2479 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2480 BOOL done = FALSE;
2481 int yield = FAIL;
2482 int i;
2483
2484 for (i = 0; i < 3 && !done; i++)
2485 {
2486 header_line *h;
2487 for (h = header_list; h != NULL && !done; h = h->next)
2488 {
2489 int terminator, new_ok;
2490 uschar *s, *ss, *endname;
2491
2492 if (h->type != header_types[i]) continue;
2493 s = endname = Ustrchr(h->text, ':') + 1;
2494
2495 /* Scan the addresses in the header, enabling group syntax. Note that we
2496 have to reset this after the header has been scanned. */
2497
2498 parse_allow_group = TRUE;
2499
2500 while (*s != 0)
2501 {
2502 address_item *vaddr;
2503
2504 while (isspace(*s) || *s == ',') s++;
2505 if (*s == 0) break; /* End of header */
2506
2507 ss = parse_find_address_end(s, FALSE);
2508
2509 /* The terminator is a comma or end of header, but there may be white
2510 space preceding it (including newline for the last address). Move back
2511 past any white space so we can check against any cached envelope sender
2512 address verifications. */
2513
2514 while (isspace(ss[-1])) ss--;
2515 terminator = *ss;
2516 *ss = 0;
2517
2518 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2519 (int)(endname - h->text), h->text, s);
2520
2521 /* See if we have already verified this address as an envelope sender,
2522 and if so, use the previous answer. */
2523
2524 vaddr = verify_checked_sender(s);
2525
2526 if (vaddr != NULL && /* Previously checked */
2527 (callout <= 0 || /* No callout needed; OR */
2528 vaddr->special_action > 256)) /* Callout was done */
2529 {
2530 new_ok = vaddr->special_action & 255;
2531 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2532 *ss = terminator; /* Restore shortened string */
2533 }
2534
2535 /* Otherwise we run the verification now. We must restore the shortened
2536 string before running the verification, so the headers are correct, in
2537 case there is any rewriting. */
2538
2539 else
2540 {
2541 int start, end, domain;
2542 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2543 &domain, FALSE);
2544
2545 *ss = terminator;
2546
2547 /* If we found an empty address, just carry on with the next one, but
2548 kill the message. */
2549
2550 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2551 {
2552 *log_msgptr = NULL;
2553 s = ss;
2554 continue;
2555 }
2556
2557 /* If verification failed because of a syntax error, fail this
2558 function, and ensure that the failing address gets added to the error
2559 message. */
2560
2561 if (address == NULL)
2562 {
2563 new_ok = FAIL;
2564 while (ss > s && isspace(ss[-1])) ss--;
2565 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2566 "scanning for sender: %s in \"%.*s\"",
2567 endname - h->text, h->text, *log_msgptr, ss - s, s);
2568 yield = FAIL;
2569 done = TRUE;
2570 break;
2571 }
2572
2573 /* Else go ahead with the sender verification. But it isn't *the*
2574 sender of the message, so set vopt_fake_sender to stop sender_address
2575 being replaced after rewriting or qualification. */
2576
2577 else
2578 {
2579 vaddr = deliver_make_addr(address, FALSE);
2580 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2581 callout, callout_overall, callout_connect, se_mailfrom,
2582 pm_mailfrom, NULL);
2583 }
2584 }
2585
2586 /* We now have the result, either newly found, or cached. If we are
2587 giving out error details, set a specific user error. This means that the
2588 last of these will be returned to the user if all three fail. We do not
2589 set a log message - the generic one below will be used. */
2590
2591 if (new_ok != OK)
2592 {
2593 *verrno = vaddr->basic_errno;
2594 if (smtp_return_error_details)
2595 {
2596 *user_msgptr = string_sprintf("Rejected after DATA: "
2597 "could not verify \"%.*s\" header address\n%s: %s",
2598 endname - h->text, h->text, vaddr->address, vaddr->message);
2599 }
2600 }
2601
2602 /* Success or defer */
2603
2604 if (new_ok == OK)
2605 {
2606 yield = OK;
2607 done = TRUE;
2608 break;
2609 }
2610
2611 if (new_ok == DEFER) yield = DEFER;
2612
2613 /* Move on to any more addresses in the header */
2614
2615 s = ss;
2616 } /* Next address */
2617
2618 parse_allow_group = FALSE;
2619 parse_found_group = FALSE;
2620 } /* Next header, unless done */
2621 } /* Next header type unless done */
2622
2623 if (yield == FAIL && *log_msgptr == NULL)
2624 *log_msgptr = US"there is no valid sender in any header line";
2625
2626 if (yield == DEFER && *log_msgptr == NULL)
2627 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2628
2629 return yield;
2630 }
2631
2632
2633
2634
2635 /*************************************************
2636 * Get RFC 1413 identification *
2637 *************************************************/
2638
2639 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2640 the timeout is set to zero, then the query is not done. There may also be lists
2641 of hosts and nets which are exempt. To guard against malefactors sending
2642 non-printing characters which could, for example, disrupt a message's headers,
2643 make sure the string consists of printing characters only.
2644
2645 Argument:
2646 port the port to connect to; usually this is IDENT_PORT (113), but when
2647 running in the test harness with -bh a different value is used.
2648
2649 Returns: nothing
2650
2651 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2652 */
2653
2654 void
2655 verify_get_ident(int port)
2656 {
2657 int sock, host_af, qlen;
2658 int received_sender_port, received_interface_port, n;
2659 uschar *p;
2660 uschar buffer[2048];
2661
2662 /* Default is no ident. Check whether we want to do an ident check for this
2663 host. */
2664
2665 sender_ident = NULL;
2666 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2667 return;
2668
2669 DEBUG(D_ident) debug_printf("doing ident callback\n");
2670
2671 /* Set up a connection to the ident port of the remote host. Bind the local end
2672 to the incoming interface address. If the sender host address is an IPv6
2673 address, the incoming interface address will also be IPv6. */
2674
2675 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2676 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2677
2678 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2679 {
2680 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2681 strerror(errno));
2682 goto END_OFF;
2683 }
2684
2685 if (ip_connect(sock, host_af, sender_host_address, port,
2686 rfc1413_query_timeout, TRUE) < 0)
2687 {
2688 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2689 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2690 sender_host_address);
2691 else
2692 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2693 sender_host_address, strerror(errno));
2694 goto END_OFF;
2695 }
2696
2697 /* Construct and send the query. */
2698
2699 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2700 qlen = Ustrlen(buffer);
2701 if (send(sock, buffer, qlen, 0) < 0)
2702 {
2703 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2704 goto END_OFF;
2705 }
2706
2707 /* Read a response line. We put it into the rest of the buffer, using several
2708 recv() calls if necessary. */
2709
2710 p = buffer + qlen;
2711
2712 for (;;)
2713 {
2714 uschar *pp;
2715 int count;
2716 int size = sizeof(buffer) - (p - buffer);
2717
2718 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2719 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2720 if (count <= 0) goto END_OFF; /* Read error or EOF */
2721
2722 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2723 generous, and accept a plain \n terminator as well. The only illegal
2724 character is 0. */
2725
2726 for (pp = p; pp < p + count; pp++)
2727 {
2728 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2729 if (*pp == '\n')
2730 {
2731 if (pp[-1] == '\r') pp--;
2732 *pp = 0;
2733 goto GOT_DATA; /* Break out of both loops */
2734 }
2735 }
2736
2737 /* Reached the end of the data without finding \n. Let the loop continue to
2738 read some more, if there is room. */
2739
2740 p = pp;
2741 }
2742
2743 GOT_DATA:
2744
2745 /* We have received a line of data. Check it carefully. It must start with the
2746 same two port numbers that we sent, followed by data as defined by the RFC. For
2747 example,
2748
2749 12345 , 25 : USERID : UNIX :root
2750
2751 However, the amount of white space may be different to what we sent. In the
2752 "osname" field there may be several sub-fields, comma separated. The data we
2753 actually want to save follows the third colon. Some systems put leading spaces
2754 in it - we discard those. */
2755
2756 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2757 &received_interface_port, &n) != 2 ||
2758 received_sender_port != sender_host_port ||
2759 received_interface_port != interface_port)
2760 goto END_OFF;
2761
2762 p = buffer + qlen + n;
2763 while(isspace(*p)) p++;
2764 if (*p++ != ':') goto END_OFF;
2765 while(isspace(*p)) p++;
2766 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2767 p += 6;
2768 while(isspace(*p)) p++;
2769 if (*p++ != ':') goto END_OFF;
2770 while (*p != 0 && *p != ':') p++;
2771 if (*p++ == 0) goto END_OFF;
2772 while(isspace(*p)) p++;
2773 if (*p == 0) goto END_OFF;
2774
2775 /* The rest of the line is the data we want. We turn it into printing
2776 characters when we save it, so that it cannot mess up the format of any logging
2777 or Received: lines into which it gets inserted. We keep a maximum of 127
2778 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2779
2780 sender_ident = US string_printing(string_copyn(p, 127));
2781 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2782
2783 END_OFF:
2784 (void)close(sock);
2785 return;
2786 }
2787
2788
2789
2790
2791 /*************************************************
2792 * Match host to a single host-list item *
2793 *************************************************/
2794
2795 /* This function compares a host (name or address) against a single item
2796 from a host list. The host name gets looked up if it is needed and is not
2797 already known. The function is called from verify_check_this_host() via
2798 match_check_list(), which is why most of its arguments are in a single block.
2799
2800 Arguments:
2801 arg the argument block (see below)
2802 ss the host-list item
2803 valueptr where to pass back looked up data, or NULL
2804 error for error message when returning ERROR
2805
2806 The block contains:
2807 host_name (a) the host name, or
2808 (b) NULL, implying use sender_host_name and
2809 sender_host_aliases, looking them up if required, or
2810 (c) the empty string, meaning that only IP address matches
2811 are permitted
2812 host_address the host address
2813 host_ipv4 the IPv4 address taken from an IPv6 one
2814
2815 Returns: OK matched
2816 FAIL did not match
2817 DEFER lookup deferred
2818 ERROR (a) failed to find the host name or IP address, or
2819 (b) unknown lookup type specified, or
2820 (c) host name encountered when only IP addresses are
2821 being matched
2822 */
2823
2824 int
2825 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2826 {
2827 check_host_block *cb = (check_host_block *)arg;
2828 int mlen = -1;
2829 int maskoffset;
2830 BOOL iplookup = FALSE;
2831 BOOL isquery = FALSE;
2832 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2833 const uschar *t;
2834 uschar *semicolon;
2835 uschar **aliases;
2836
2837 /* Optimize for the special case when the pattern is "*". */
2838
2839 if (*ss == '*' && ss[1] == 0) return OK;
2840
2841 /* If the pattern is empty, it matches only in the case when there is no host -
2842 this can occur in ACL checking for SMTP input using the -bs option. In this
2843 situation, the host address is the empty string. */
2844
2845 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2846 if (*ss == 0) return FAIL;
2847
2848 /* If the pattern is precisely "@" then match against the primary host name,
2849 provided that host name matching is permitted; if it's "@[]" match against the
2850 local host's IP addresses. */
2851
2852 if (*ss == '@')
2853 {
2854 if (ss[1] == 0)
2855 {
2856 if (isiponly) return ERROR;
2857 ss = primary_hostname;
2858 }
2859 else if (Ustrcmp(ss, "@[]") == 0)
2860 {
2861 ip_address_item *ip;
2862 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2863 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2864 return FAIL;
2865 }
2866 }
2867
2868 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2869 a (possibly masked) comparison with the current IP address. */
2870
2871 if (string_is_ip_address(ss, &maskoffset) != 0)
2872 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2873
2874 /* The pattern is not an IP address. A common error that people make is to omit
2875 one component of an IPv4 address, either by accident, or believing that, for
2876 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,
2877 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2878 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2879 ancient specification.) To aid in debugging these cases, we give a specific
2880 error if the pattern contains only digits and dots or contains a slash preceded
2881 only by digits and dots (a slash at the start indicates a file name and of
2882 course slashes may be present in lookups, but not preceded only by digits and
2883 dots). */
2884
2885 for (t = ss; isdigit(*t) || *t == '.'; t++);
2886 if (*t == 0 || (*t == '/' && t != ss))
2887 {
2888 *error = US"malformed IPv4 address or address mask";
2889 return ERROR;
2890 }
2891
2892 /* See if there is a semicolon in the pattern */
2893
2894 semicolon = Ustrchr(ss, ';');
2895
2896 /* If we are doing an IP address only match, then all lookups must be IP
2897 address lookups, even if there is no "net-". */
2898
2899 if (isiponly)
2900 {
2901 iplookup = semicolon != NULL;
2902 }
2903
2904 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2905 a lookup on a masked IP network, in textual form. We obey this code even if we
2906 have already set iplookup, so as to skip over the "net-" prefix and to set the
2907 mask length. The net- stuff really only applies to single-key lookups where the
2908 key is implicit. For query-style lookups the key is specified in the query.
2909 From release 4.30, the use of net- for query style is no longer needed, but we
2910 retain it for backward compatibility. */
2911
2912 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2913 {
2914 mlen = 0;
2915 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2916 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2917 iplookup = (*t++ == '-');
2918 }
2919 else t = ss;
2920
2921 /* Do the IP address lookup if that is indeed what we have */
2922
2923 if (iplookup)
2924 {
2925 int insize;
2926 int search_type;
2927 int incoming[4];
2928 void *handle;
2929 uschar *filename, *key, *result;
2930 uschar buffer[64];
2931
2932 /* Find the search type */
2933
2934 search_type = search_findtype(t, semicolon - t);
2935
2936 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2937 search_error_message);
2938
2939 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2940 is no file name, and the "key" is just the query. For query-style with a file
2941 name, we have to fish the file off the start of the query. For a single-key
2942 lookup, the key is the current IP address, masked appropriately, and
2943 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2944 dot separators instead of colons, except when the lookup type is "iplsearch".
2945 */
2946
2947 if (mac_islookup(search_type, lookup_absfilequery))
2948 {
2949 filename = semicolon + 1;
2950 key = filename;
2951 while (*key != 0 && !isspace(*key)) key++;
2952 filename = string_copyn(filename, key - filename);
2953 while (isspace(*key)) key++;
2954 }
2955 else if (mac_islookup(search_type, lookup_querystyle))
2956 {
2957 filename = NULL;
2958 key = semicolon + 1;
2959 }
2960 else /* Single-key style */
2961 {
2962 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2963 ':' : '.';
2964 insize = host_aton(cb->host_address, incoming);
2965 host_mask(insize, incoming, mlen);
2966 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2967 key = buffer;
2968 filename = semicolon + 1;
2969 }
2970
2971 /* Now do the actual lookup; note that there is no search_close() because
2972 of the caching arrangements. */
2973
2974 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2975 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2976
2977 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2978 if (valueptr != NULL) *valueptr = result;
2979 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2980 }
2981
2982 /* The pattern is not an IP address or network reference of any kind. That is,
2983 it is a host name pattern. If this is an IP only match, there's an error in the
2984 host list. */
2985
2986 if (isiponly)
2987 {
2988 *error = US"cannot match host name in match_ip list";
2989 return ERROR;
2990 }
2991
2992 /* Check the characters of the pattern to see if they comprise only letters,
2993 digits, full stops, and hyphens (the constituents of domain names). Allow
2994 underscores, as they are all too commonly found. Sigh. Also, if
2995 allow_utf8_domains is set, allow top-bit characters. */
2996
2997 for (t = ss; *t != 0; t++)
2998 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2999 (!allow_utf8_domains || *t < 128)) break;
3000
3001 /* If the pattern is a complete domain name, with no fancy characters, look up
3002 its IP address and match against that. Note that a multi-homed host will add
3003 items to the chain. */
3004
3005 if (*t == 0)
3006 {
3007 int rc;
3008 host_item h;
3009 h.next = NULL;
3010 h.name = ss;
3011 h.address = NULL;
3012 h.mx = MX_NONE;
3013
3014 /* Using byname rather than bydns here means we cannot determine dnssec
3015 status. On the other hand it is unclear how that could be either
3016 propagated up or enforced. */
3017
3018 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3019 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3020 {
3021 host_item *hh;
3022 for (hh = &h; hh != NULL; hh = hh->next)
3023 {
3024 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3025 }
3026 return FAIL;
3027 }
3028 if (rc == HOST_FIND_AGAIN) return DEFER;
3029 *error = string_sprintf("failed to find IP address for %s", ss);
3030 return ERROR;
3031 }
3032
3033 /* Almost all subsequent comparisons require the host name, and can be done
3034 using the general string matching function. When this function is called for
3035 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3036 must use sender_host_name and its aliases, looking them up if necessary. */
3037
3038 if (cb->host_name != NULL) /* Explicit host name given */
3039 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3040 valueptr);
3041
3042 /* Host name not given; in principle we need the sender host name and its
3043 aliases. However, for query-style lookups, we do not need the name if the
3044 query does not contain $sender_host_name. From release 4.23, a reference to
3045 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3046 on spec. */
3047
3048 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3049 {
3050 const uschar *affix;
3051 int partial, affixlen, starflags, id;
3052
3053 *semicolon = 0;
3054 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3055 *semicolon=';';
3056
3057 if (id < 0) /* Unknown lookup type */
3058 {
3059 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3060 search_error_message, ss);
3061 return DEFER;
3062 }
3063 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3064 }
3065
3066 if (isquery)
3067 {
3068 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3069 {
3070 case OK: return OK;
3071 case DEFER: return DEFER;
3072 default: return FAIL;
3073 }
3074 }
3075
3076 /* Not a query-style lookup; must ensure the host name is present, and then we
3077 do a check on the name and all its aliases. */
3078
3079 if (sender_host_name == NULL)
3080 {
3081 HDEBUG(D_host_lookup)
3082 debug_printf("sender host name required, to match against %s\n", ss);
3083 if (host_lookup_failed || host_name_lookup() != OK)
3084 {
3085 *error = string_sprintf("failed to find host name for %s",
3086 sender_host_address);;
3087 return ERROR;
3088 }
3089 host_build_sender_fullhost();
3090 }
3091
3092 /* Match on the sender host name, using the general matching function */
3093
3094 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3095 valueptr))
3096 {
3097 case OK: return OK;
3098 case DEFER: return DEFER;
3099 }
3100
3101 /* If there are aliases, try matching on them. */
3102
3103 aliases = sender_host_aliases;
3104 while (*aliases != NULL)
3105 {
3106 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3107 {
3108 case OK: return OK;
3109 case DEFER: return DEFER;
3110 }
3111 }
3112 return FAIL;
3113 }
3114
3115
3116
3117
3118 /*************************************************
3119 * Check a specific host matches a host list *
3120 *************************************************/
3121
3122 /* This function is passed a host list containing items in a number of
3123 different formats and the identity of a host. Its job is to determine whether
3124 the given host is in the set of hosts defined by the list. The host name is
3125 passed as a pointer so that it can be looked up if needed and not already
3126 known. This is commonly the case when called from verify_check_host() to check
3127 an incoming connection. When called from elsewhere the host name should usually
3128 be set.
3129
3130 This function is now just a front end to match_check_list(), which runs common
3131 code for scanning a list. We pass it the check_host() function to perform a
3132 single test.
3133
3134 Arguments:
3135 listptr pointer to the host list
3136 cache_bits pointer to cache for named lists, or NULL
3137 host_name the host name or NULL, implying use sender_host_name and
3138 sender_host_aliases, looking them up if required
3139 host_address the IP address
3140 valueptr if not NULL, data from a lookup is passed back here
3141
3142 Returns: OK if the host is in the defined set
3143 FAIL if the host is not in the defined set,
3144 DEFER if a data lookup deferred (not a host lookup)
3145
3146 If the host name was needed in order to make a comparison, and could not be
3147 determined from the IP address, the result is FAIL unless the item
3148 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3149
3150 int
3151 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3152 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3153 {
3154 int rc;
3155 unsigned int *local_cache_bits = cache_bits;
3156 const uschar *save_host_address = deliver_host_address;
3157 check_host_block cb;
3158 cb.host_name = host_name;
3159 cb.host_address = host_address;
3160
3161 if (valueptr != NULL) *valueptr = NULL;
3162
3163 /* If the host address starts off ::ffff: it is an IPv6 address in
3164 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3165 addresses. */
3166
3167 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3168 host_address + 7 : host_address;
3169
3170 /* During the running of the check, put the IP address into $host_address. In
3171 the case of calls from the smtp transport, it will already be there. However,
3172 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3173 the safe side, any existing setting is preserved, though as I write this
3174 (November 2004) I can't see any cases where it is actually needed. */
3175
3176 deliver_host_address = host_address;
3177 rc = match_check_list(
3178 listptr, /* the list */
3179 0, /* separator character */
3180 &hostlist_anchor, /* anchor pointer */
3181 &local_cache_bits, /* cache pointer */
3182 check_host, /* function for testing */
3183 &cb, /* argument for function */
3184 MCL_HOST, /* type of check */
3185 (host_address == sender_host_address)?
3186 US"host" : host_address, /* text for debugging */
3187 valueptr); /* where to pass back data */
3188 deliver_host_address = save_host_address;
3189 return rc;
3190 }
3191
3192
3193
3194
3195 /*************************************************
3196 * Check the given host item matches a list *
3197 *************************************************/
3198 int
3199 verify_check_given_host(uschar **listptr, host_item *host)
3200 {
3201 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3202 }
3203
3204 /*************************************************
3205 * Check the remote host matches a list *
3206 *************************************************/
3207
3208 /* This is a front end to verify_check_this_host(), created because checking
3209 the remote host is a common occurrence. With luck, a good compiler will spot
3210 the tail recursion and optimize it. If there's no host address, this is
3211 command-line SMTP input - check against an empty string for the address.
3212
3213 Arguments:
3214 listptr pointer to the host list
3215
3216 Returns: the yield of verify_check_this_host(),
3217 i.e. OK, FAIL, or DEFER
3218 */
3219
3220 int
3221 verify_check_host(uschar **listptr)
3222 {
3223 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3224 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3225 }
3226
3227
3228
3229
3230
3231 /*************************************************
3232 * Invert an IP address *
3233 *************************************************/
3234
3235 /* Originally just used for DNS xBL lists, now also used for the
3236 reverse_ip expansion operator.
3237
3238 Arguments:
3239 buffer where to put the answer
3240 address the address to invert
3241 */
3242
3243 void
3244 invert_address(uschar *buffer, uschar *address)
3245 {
3246 int bin[4];
3247 uschar *bptr = buffer;
3248
3249 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3250 to the IPv4 part only. */
3251
3252 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3253
3254 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3255 always 1. */
3256
3257 if (host_aton(address, bin) == 1)
3258 {
3259 int i;
3260 int x = bin[0];
3261 for (i = 0; i < 4; i++)
3262 {
3263 sprintf(CS bptr, "%d.", x & 255);
3264 while (*bptr) bptr++;
3265 x >>= 8;
3266 }
3267 }
3268
3269 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3270 in any DNS black lists, and the format in which they will be looked up is
3271 unknown. This is just a guess. */
3272
3273 #if HAVE_IPV6
3274 else
3275 {
3276 int i, j;
3277 for (j = 3; j >= 0; j--)
3278 {
3279 int x = bin[j];
3280 for (i = 0; i < 8; i++)
3281 {
3282 sprintf(CS bptr, "%x.", x & 15);
3283 while (*bptr) bptr++;
3284 x >>= 4;
3285 }
3286 }
3287 }
3288 #endif
3289
3290 /* Remove trailing period -- this is needed so that both arbitrary
3291 dnsbl keydomains and inverted addresses may be combined with the
3292 same format string, "%s.%s" */
3293
3294 *(--bptr) = 0;
3295 }
3296
3297
3298
3299 /*************************************************
3300 * Perform a single dnsbl lookup *
3301 *************************************************/
3302
3303 /* This function is called from verify_check_dnsbl() below. It is also called
3304 recursively from within itself when domain and domain_txt are different
3305 pointers, in order to get the TXT record from the alternate domain.
3306
3307 Arguments:
3308 domain the outer dnsbl domain
3309 domain_txt alternate domain to lookup TXT record on success; when the
3310 same domain is to be used, domain_txt == domain (that is,
3311 the pointers must be identical, not just the text)
3312 keydomain the current keydomain (for debug message)
3313 prepend subdomain to lookup (like keydomain, but
3314 reversed if IP address)
3315 iplist the list of matching IP addresses, or NULL for "any"
3316 bitmask true if bitmask matching is wanted
3317 match_type condition for 'succeed' result
3318 0 => Any RR in iplist (=)
3319 1 => No RR in iplist (!=)
3320 2 => All RRs in iplist (==)
3321 3 => Some RRs not in iplist (!==)
3322 the two bits are defined as MT_NOT and MT_ALL
3323 defer_return what to return for a defer
3324
3325 Returns: OK if lookup succeeded
3326 FAIL if not
3327 */
3328
3329 static int
3330 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3331 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3332 int defer_return)
3333 {
3334 dns_answer dnsa;
3335 dns_scan dnss;
3336 tree_node *t;
3337 dnsbl_cache_block *cb;
3338 int old_pool = store_pool;
3339 uschar query[256]; /* DNS domain max length */
3340
3341 /* Construct the specific query domainname */
3342
3343 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3344 {
3345 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3346 "(ignored): %s...", query);
3347 return FAIL;
3348 }
3349
3350 /* Look for this query in the cache. */
3351
3352 if ( (t = tree_search(dnsbl_cache, query))
3353 && (cb = t->data.ptr)->expiry > time(NULL)
3354 )
3355
3356 /* Previous lookup was cached */
3357
3358 {
3359 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3360 }
3361
3362 /* If not cached from a previous lookup, we must do a DNS lookup, and
3363 cache the result in permanent memory. */
3364
3365 else
3366 {
3367 uint ttl = 3600;
3368
3369 store_pool = POOL_PERM;
3370
3371 if (t)
3372 {
3373 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3374 }
3375
3376 else
3377 { /* Set up a tree entry to cache the lookup */
3378 t = store_get(sizeof(tree_node) + Ustrlen(query));
3379 Ustrcpy(t->name, query);
3380 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3381 (void)tree_insertnode(&dnsbl_cache, t);
3382 }
3383
3384 /* Do the DNS lookup . */
3385
3386 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3387 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3388 cb->text_set = FALSE;
3389 cb->text = NULL;
3390 cb->rhs = NULL;
3391
3392 /* If the lookup succeeded, cache the RHS address. The code allows for
3393 more than one address - this was for complete generality and the possible
3394 use of A6 records. However, A6 records have been reduced to experimental
3395 status (August 2001) and may die out. So they may never get used at all,
3396 let alone in dnsbl records. However, leave the code here, just in case.
3397
3398 Quite apart from one A6 RR generating multiple addresses, there are DNS
3399 lists that return more than one A record, so we must handle multiple
3400 addresses generated in that way as well.
3401
3402 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3403 or some suitably far-future time if none were found. */
3404
3405 if (cb->rc == DNS_SUCCEED)
3406 {
3407 dns_record *rr;
3408 dns_address **addrp = &(cb->rhs);
3409 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3410 rr;
3411 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3412 {
3413 if (rr->type == T_A)
3414 {
3415 dns_address *da = dns_address_from_rr(&dnsa, rr);
3416 if (da)
3417 {
3418 *addrp = da;
3419 while (da->next != NULL) da = da->next;
3420 addrp = &(da->next);
3421 if (ttl > rr->ttl) ttl = rr->ttl;
3422 }
3423 }
3424 }
3425
3426 /* If we didn't find any A records, change the return code. This can
3427 happen when there is a CNAME record but there are no A records for what
3428 it points to. */
3429
3430 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3431 }
3432
3433 cb->expiry = time(NULL)+ttl;
3434 store_pool = old_pool;
3435 }
3436
3437 /* We now have the result of the DNS lookup, either newly done, or cached
3438 from a previous call. If the lookup succeeded, check against the address
3439 list if there is one. This may be a positive equality list (introduced by
3440 "="), a negative equality list (introduced by "!="), a positive bitmask
3441 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3442
3443 if (cb->rc == DNS_SUCCEED)
3444 {
3445 dns_address *da = NULL;
3446 uschar *addlist = cb->rhs->address;
3447
3448 /* For A and AAAA records, there may be multiple addresses from multiple
3449 records. For A6 records (currently not expected to be used) there may be
3450 multiple addresses from a single record. */
3451
3452 for (da = cb->rhs->next; da != NULL; da = da->next)
3453 addlist = string_sprintf("%s, %s", addlist, da->address);