TLS: move from SUPPORT_TLS to DISABLE_TLS macro for the build
[exim.git] / src / src / verify.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
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_context ctctx;
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(client_conn_ctx *, 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 if (!(cache_record = dbfn_read_with_length(dbm_file, key, &length)))
72 {
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
74 return NULL;
75 }
76
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
79
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
83 now = time(NULL);
84
85 if (now - cache_record->time_stamp > expire)
86 {
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
88 return NULL;
89 }
90
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
96
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
98 {
99 if (length == sizeof(dbdata_callout_cache_obs))
100 {
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
104 cache_record = new;
105 }
106
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
109
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
112 }
113
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
115 return cache_record;
116 }
117
118
119
120 /* Check the callout cache.
121 Options * pm_mailfrom may be modified by cache partial results.
122
123 Return: TRUE if result found
124 */
125
126 static BOOL
127 cached_callout_lookup(address_item * addr, uschar * address_key,
128 uschar * from_address, int * opt_ptr, uschar ** pm_ptr,
129 int * yield, uschar ** failure_ptr,
130 dbdata_callout_cache * new_domain_record, int * old_domain_res)
131 {
132 int options = *opt_ptr;
133 open_db dbblock;
134 open_db *dbm_file = NULL;
135
136 /* Open the callout cache database, it it exists, for reading only at this
137 stage, unless caching has been disabled. */
138
139 if (options & vopt_callout_no_cache)
140 {
141 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
142 }
143 else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE, TRUE)))
144 {
145 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
146 }
147 else
148 {
149 /* If a cache database is available see if we can avoid the need to do an
150 actual callout by making use of previously-obtained data. */
151
152 dbdata_callout_cache_address * cache_address_record;
153 dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file,
154 addr->domain, US"domain",
155 callout_cache_domain_positive_expire, callout_cache_domain_negative_expire);
156
157 /* If an unexpired cache record was found for this domain, see if the callout
158 process can be short-circuited. */
159
160 if (cache_record)
161 {
162 /* In most cases, if an early command (up to and including MAIL FROM:<>)
163 was rejected, there is no point carrying on. The callout fails. However, if
164 we are doing a recipient verification with use_sender or use_postmaster
165 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
166 will be using a non-empty sender. We have to remember this situation so as
167 not to disturb the cached domain value if this whole verification succeeds
168 (we don't want it turning into "accept"). */
169
170 *old_domain_res = cache_record->result;
171
172 if ( cache_record->result == ccache_reject
173 || *from_address == 0 && cache_record->result == ccache_reject_mfnull)
174 {
175 HDEBUG(D_verify)
176 debug_printf("callout cache: domain gave initial rejection, or "
177 "does not accept HELO or MAIL FROM:<>\n");
178 setflag(addr, af_verify_nsfail);
179 addr->user_message = US"(result of an earlier callout reused).";
180 *yield = FAIL;
181 *failure_ptr = US"mail";
182 dbfn_close(dbm_file);
183 return TRUE;
184 }
185
186 /* If a previous check on a "random" local part was accepted, we assume
187 that the server does not do any checking on local parts. There is therefore
188 no point in doing the callout, because it will always be successful. If a
189 random check previously failed, arrange not to do it again, but preserve
190 the data in the new record. If a random check is required but hasn't been
191 done, skip the remaining cache processing. */
192
193 if (options & vopt_callout_random) switch(cache_record->random_result)
194 {
195 case ccache_accept:
196 HDEBUG(D_verify)
197 debug_printf("callout cache: domain accepts random addresses\n");
198 *failure_ptr = US"random";
199 dbfn_close(dbm_file);
200 return TRUE; /* Default yield is OK */
201
202 case ccache_reject:
203 HDEBUG(D_verify)
204 debug_printf("callout cache: domain rejects random addresses\n");
205 *opt_ptr = options & ~vopt_callout_random;
206 new_domain_record->random_result = ccache_reject;
207 new_domain_record->random_stamp = cache_record->random_stamp;
208 break;
209
210 default:
211 HDEBUG(D_verify)
212 debug_printf("callout cache: need to check random address handling "
213 "(not cached or cache expired)\n");
214 dbfn_close(dbm_file);
215 return FALSE;
216 }
217
218 /* If a postmaster check is requested, but there was a previous failure,
219 there is again no point in carrying on. If a postmaster check is required,
220 but has not been done before, we are going to have to do a callout, so skip
221 remaining cache processing. */
222
223 if (*pm_ptr)
224 {
225 if (cache_record->postmaster_result == ccache_reject)
226 {
227 setflag(addr, af_verify_pmfail);
228 HDEBUG(D_verify)
229 debug_printf("callout cache: domain does not accept "
230 "RCPT TO:<postmaster@domain>\n");
231 *yield = FAIL;
232 *failure_ptr = US"postmaster";
233 setflag(addr, af_verify_pmfail);
234 addr->user_message = US"(result of earlier verification reused).";
235 dbfn_close(dbm_file);
236 return TRUE;
237 }
238 if (cache_record->postmaster_result == ccache_unknown)
239 {
240 HDEBUG(D_verify)
241 debug_printf("callout cache: need to check RCPT "
242 "TO:<postmaster@domain> (not cached or cache expired)\n");
243 dbfn_close(dbm_file);
244 return FALSE;
245 }
246
247 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
248 postmaster check if the address itself has to be checked. Also ensure
249 that the value in the cache record is preserved (with its old timestamp).
250 */
251
252 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
253 "TO:<postmaster@domain>\n");
254 *pm_ptr = NULL;
255 new_domain_record->postmaster_result = ccache_accept;
256 new_domain_record->postmaster_stamp = cache_record->postmaster_stamp;
257 }
258 }
259
260 /* We can't give a result based on information about the domain. See if there
261 is an unexpired cache record for this specific address (combined with the
262 sender address if we are doing a recipient callout with a non-empty sender).
263 */
264
265 if (!(cache_address_record = (dbdata_callout_cache_address *)
266 get_callout_cache_record(dbm_file, address_key, US"address",
267 callout_cache_positive_expire, callout_cache_negative_expire)))
268 {
269 dbfn_close(dbm_file);
270 return FALSE;
271 }
272
273 if (cache_address_record->result == ccache_accept)
274 {
275 HDEBUG(D_verify)
276 debug_printf("callout cache: address record is positive\n");
277 }
278 else
279 {
280 HDEBUG(D_verify)
281 debug_printf("callout cache: address record is negative\n");
282 addr->user_message = US"Previous (cached) callout verification failure";
283 *failure_ptr = US"recipient";
284 *yield = FAIL;
285 }
286
287 /* Close the cache database while we actually do the callout for real. */
288
289 dbfn_close(dbm_file);
290 return TRUE;
291 }
292 return FALSE;
293 }
294
295
296 /* Write results to callout cache
297 */
298 static void
299 cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain,
300 int done, dbdata_callout_cache_address * addr_rec, uschar * address_key)
301 {
302 open_db dbblock;
303 open_db *dbm_file = NULL;
304
305 /* If we get here with done == TRUE, a successful callout happened, and yield
306 will be set OK or FAIL according to the response to the RCPT command.
307 Otherwise, we looped through the hosts but couldn't complete the business.
308 However, there may be domain-specific information to cache in both cases.
309
310 The value of the result field in the new_domain record is ccache_unknown if
311 there was an error before or with MAIL FROM:, and errno was not zero,
312 implying some kind of I/O error. We don't want to write the cache in that case.
313 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
314
315 if (dom_rec->result != ccache_unknown)
316 if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE, TRUE)))
317 {
318 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
319 }
320 else
321 {
322 (void)dbfn_write(dbm_file, domain, dom_rec,
323 (int)sizeof(dbdata_callout_cache));
324 HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
325 " result=%d postmaster=%d random=%d\n",
326 domain,
327 dom_rec->result,
328 dom_rec->postmaster_result,
329 dom_rec->random_result);
330 }
331
332 /* If a definite result was obtained for the callout, cache it unless caching
333 is disabled. */
334
335 if (done && addr_rec->result != ccache_unknown)
336 {
337 if (!dbm_file)
338 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE, TRUE);
339 if (!dbm_file)
340 {
341 HDEBUG(D_verify) debug_printf("no callout cache available\n");
342 }
343 else
344 {
345 (void)dbfn_write(dbm_file, address_key, addr_rec,
346 (int)sizeof(dbdata_callout_cache_address));
347 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
348 addr_rec->result == ccache_accept ? "positive" : "negative",
349 address_key);
350 }
351 }
352
353 if (dbm_file) dbfn_close(dbm_file);
354 }
355
356
357 /* Cutthrough-multi. If the existing cached cutthrough connection matches
358 the one we would make for a subsequent recipient, use it. Send the RCPT TO
359 and check the result, nonpipelined as it may be wanted immediately for
360 recipient-verification.
361
362 It seems simpler to deal with this case separately from the main callout loop.
363 We will need to remember it has sent, or not, so that rcpt-acl tail code
364 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
365
366 Return: TRUE for a definitive result for the recipient
367 */
368 static int
369 cutthrough_multi(address_item * addr, host_item * host_list,
370 transport_feedback * tf, int * yield)
371 {
372 BOOL done = FALSE;
373
374 if (addr->transport == cutthrough.addr.transport)
375 for (host_item * host = host_list; host; host = host->next)
376 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
377 {
378 int host_af;
379 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
380 int port = 25;
381
382 deliver_host = host->name;
383 deliver_host_address = host->address;
384 deliver_host_port = host->port;
385 deliver_domain = addr->domain;
386 transport_name = addr->transport->name;
387
388 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
389
390 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
391 US"callout")
392 || !smtp_get_port(tf->port, addr, &port, US"callout")
393 )
394 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
395 addr->message);
396
397 smtp_port_for_connect(host, port);
398
399 if ( ( interface == cutthrough.interface
400 || ( interface
401 && cutthrough.interface
402 && Ustrcmp(interface, cutthrough.interface) == 0
403 ) )
404 && host->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(&ctctx, SCMD_FLUSH, "RCPT TO:<%.1000s>\r\n",
412 transport_rcpt_address(addr,
413 addr->transport->rcpt_include_affixes)) >= 0
414 && cutthrough_response(&cutthrough.cctx, '2', &resp,
415 CUTTHROUGH_DATA_TIMEOUT) == '2';
416
417 /* This would go horribly wrong if a callout fail was ignored by ACL.
418 We punt by abandoning cutthrough on a reject, like the
419 first-rcpt does. */
420
421 if (done)
422 {
423 address_item * na = store_get(sizeof(address_item));
424 *na = cutthrough.addr;
425 cutthrough.addr = *addr;
426 cutthrough.addr.host_used = &cutthrough.host;
427 cutthrough.addr.next = na;
428
429 cutthrough.nrcpt++;
430 }
431 else
432 {
433 cancel_cutthrough_connection(TRUE, US"recipient rejected");
434 if (!resp || errno == ETIMEDOUT)
435 {
436 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
437 }
438 else if (errno == 0)
439 {
440 if (*resp == 0)
441 Ustrcpy(resp, US"connection dropped");
442
443 addr->message =
444 string_sprintf("response to \"%s\" was: %s",
445 big_buffer, string_printing(resp));
446
447 addr->user_message =
448 string_sprintf("Callout verification failed:\n%s", resp);
449
450 /* Hard rejection ends the process */
451
452 if (resp[0] == '5') /* Address rejected */
453 {
454 *yield = FAIL;
455 done = TRUE;
456 }
457 }
458 }
459 }
460 break; /* host_list */
461 }
462 if (!done)
463 cancel_cutthrough_connection(TRUE, US"incompatible connection");
464 return done;
465 }
466
467
468 /*************************************************
469 * Do callout verification for an address *
470 *************************************************/
471
472 /* This function is called from verify_address() when the address has routed to
473 a host list, and a callout has been requested. Callouts are expensive; that is
474 why a cache is used to improve the efficiency.
475
476 Arguments:
477 addr the address that's been routed
478 host_list the list of hosts to try
479 tf the transport feedback block
480
481 ifstring "interface" option from transport, or NULL
482 portstring "port" option from transport, or NULL
483 protocolstring "protocol" option from transport, or NULL
484 callout the per-command callout timeout
485 callout_overall the overall callout timeout (if < 0 use 4*callout)
486 callout_connect the callout connection timeout (if < 0 use callout)
487 options the verification options - these bits are used:
488 vopt_is_recipient => this is a recipient address
489 vopt_callout_no_cache => don't use callout cache
490 vopt_callout_fullpm => if postmaster check, do full one
491 vopt_callout_random => do the "random" thing
492 vopt_callout_recipsender => use real sender for recipient
493 vopt_callout_recippmaster => use postmaster for recipient
494 vopt_callout_hold => lazy close connection
495 se_mailfrom MAIL FROM address for sender verify; NULL => ""
496 pm_mailfrom if non-NULL, do the postmaster check with this sender
497
498 Returns: OK/FAIL/DEFER
499 */
500
501 static int
502 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
503 int callout, int callout_overall, int callout_connect, int options,
504 uschar *se_mailfrom, uschar *pm_mailfrom)
505 {
506 int yield = OK;
507 int old_domain_cache_result = ccache_accept;
508 BOOL done = FALSE;
509 uschar *address_key;
510 uschar *from_address;
511 uschar *random_local_part = NULL;
512 const uschar *save_deliver_domain = deliver_domain;
513 uschar **failure_ptr = options & vopt_is_recipient
514 ? &recipient_verify_failure : &sender_verify_failure;
515 dbdata_callout_cache new_domain_record;
516 dbdata_callout_cache_address new_address_record;
517 time_t callout_start_time;
518
519 new_domain_record.result = ccache_unknown;
520 new_domain_record.postmaster_result = ccache_unknown;
521 new_domain_record.random_result = ccache_unknown;
522
523 memset(&new_address_record, 0, sizeof(new_address_record));
524
525 /* For a recipient callout, the key used for the address cache record must
526 include the sender address if we are using the real sender in the callout,
527 because that may influence the result of the callout. */
528
529 if (options & vopt_is_recipient)
530 if (options & vopt_callout_recipsender)
531 {
532 from_address = sender_address;
533 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
534 if (cutthrough.delivery) options |= vopt_callout_no_cache;
535 }
536 else if (options & vopt_callout_recippmaster)
537 {
538 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
539 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
540 qualify_domain_sender);
541 }
542 else
543 {
544 from_address = US"";
545 address_key = addr->address;
546 }
547
548 /* For a sender callout, we must adjust the key if the mailfrom address is not
549 empty. */
550
551 else
552 {
553 from_address = se_mailfrom ? se_mailfrom : US"";
554 address_key = *from_address
555 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
556 }
557
558 if (cached_callout_lookup(addr, address_key, from_address,
559 &options, &pm_mailfrom, &yield, failure_ptr,
560 &new_domain_record, &old_domain_cache_result))
561 {
562 cancel_cutthrough_connection(TRUE, US"cache-hit");
563 goto END_CALLOUT;
564 }
565
566 if (!addr->transport)
567 {
568 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
569 }
570 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
571 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
572 addr->transport->name, addr->transport->driver_name);
573 else
574 {
575 smtp_transport_options_block *ob =
576 (smtp_transport_options_block *)addr->transport->options_block;
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 && !f.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.cctx.sock >= 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_item * 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.conn_args.host = host;
671 sx.conn_args.host_af = host_af,
672 sx.port = port;
673 sx.conn_args.interface = interface;
674 sx.helo_data = tf->helo_data;
675 sx.conn_args.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 #ifndef DISABLE_TLS
691 if ( yield == DEFER
692 && addr->basic_errno == ERRNO_TLSFAILURE
693 && ob->tls_tempfail_tryclear
694 && verify_check_given_host(CUSS &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 random-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: /* random was accepted, unfortunately */
801 new_domain_record.random_result = ccache_accept;
802 yield = OK; /* Only usable verify result we can return */
803 done = TRUE;
804 *failure_ptr = US"random";
805 goto no_conn;
806 case FAIL: /* rejected: the preferred result */
807 new_domain_record.random_result = ccache_reject;
808 sx.avoid_option = 0;
809
810 /* Between each check, issue RSET, because some servers accept only
811 one recipient after MAIL FROM:<>.
812 XXX We don't care about that for postmaster_full. Should we? */
813
814 if ((done =
815 smtp_write_command(&sx, SCMD_FLUSH, "RSET\r\n") >= 0 &&
816 smtp_read_response(&sx, sx.buffer, sizeof(sx.buffer), '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 #ifndef DISABLE_TLS
823 tls_close(sx.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
824 #endif
825 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
826 (void)close(sx.cctx.sock);
827 sx.cctx.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 case DEFER: /* 4xx response to random */
840 break; /* Just to be clear. ccache_unknown, !done. */
841 }
842
843 /* Re-setup for main verify, or for the error message when failing */
844 addr->address = main_address;
845 addr->transport_return = PENDING_DEFER;
846 sx.first_addr = sx.sync_addr = addr;
847 sx.ok = FALSE;
848 sx.send_rset = TRUE;
849 sx.completed_addr = FALSE;
850 }
851 else
852 done = TRUE;
853
854 /* Main verify. For rcpt-verify use SIZE if we know it and we're not cacheing;
855 for sndr-verify never use it. */
856
857 if (done)
858 {
859 if (!(options & vopt_is_recipient && options & vopt_callout_no_cache))
860 sx.avoid_option = OPTION_SIZE;
861
862 done = FALSE;
863 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
864 {
865 case 0: switch(addr->transport_return) /* ok so far */
866 {
867 case PENDING_OK: done = TRUE;
868 new_address_record.result = ccache_accept;
869 break;
870 case FAIL: done = TRUE;
871 yield = FAIL;
872 *failure_ptr = US"recipient";
873 new_address_record.result = ccache_reject;
874 break;
875 default: break;
876 }
877 break;
878
879 case -1: /* MAIL response error */
880 *failure_ptr = US"mail";
881 if (errno == 0 && sx.buffer[0] == '5')
882 {
883 setflag(addr, af_verify_nsfail);
884 if (from_address[0] == 0)
885 new_domain_record.result = ccache_reject_mfnull;
886 }
887 break;
888 /* non-MAIL read i/o error */
889 /* non-MAIL response timeout */
890 /* internal error; channel still usable */
891 default: break; /* transmit failed */
892 }
893 }
894
895 addr->auth_sndr = client_authenticated_sender;
896
897 deliver_host = deliver_host_address = NULL;
898 deliver_domain = save_deliver_domain;
899
900 /* Do postmaster check if requested; if a full check is required, we
901 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
902
903 if (done && pm_mailfrom)
904 {
905 /* Could possibly shift before main verify, just above, and be ok
906 for cutthrough. But no way to handle a subsequent rcpt, so just
907 refuse any */
908 cancel_cutthrough_connection(TRUE, US"postmaster verify");
909 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
910
911 done = smtp_write_command(&sx, SCMD_FLUSH, "RSET\r\n") >= 0
912 && smtp_read_response(&sx, sx.buffer, sizeof(sx.buffer), '2', callout);
913
914 if (done)
915 {
916 uschar * main_address = addr->address;
917
918 /*XXX oops, affixes */
919 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
920 addr->transport_return = PENDING_DEFER;
921
922 sx.from_addr = pm_mailfrom;
923 sx.first_addr = sx.sync_addr = addr;
924 sx.ok = FALSE;
925 sx.send_rset = TRUE;
926 sx.completed_addr = FALSE;
927 sx.avoid_option = OPTION_SIZE;
928
929 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
930 && addr->transport_return == PENDING_OK
931 )
932 done = TRUE;
933 else
934 done = (options & vopt_callout_fullpm) != 0
935 && smtp_write_command(&sx, SCMD_FLUSH,
936 "RCPT TO:<postmaster>\r\n") >= 0
937 && smtp_read_response(&sx, sx.buffer,
938 sizeof(sx.buffer), '2', callout);
939
940 /* Sort out the cache record */
941
942 new_domain_record.postmaster_stamp = time(NULL);
943
944 if (done)
945 new_domain_record.postmaster_result = ccache_accept;
946 else if (errno == 0 && sx.buffer[0] == '5')
947 {
948 *failure_ptr = US"postmaster";
949 setflag(addr, af_verify_pmfail);
950 new_domain_record.postmaster_result = ccache_reject;
951 }
952
953 addr->address = main_address;
954 }
955 }
956 /* For any failure of the main check, other than a negative response, we just
957 close the connection and carry on. We can identify a negative response by the
958 fact that errno is zero. For I/O errors it will be non-zero
959
960 Set up different error texts for logging and for sending back to the caller
961 as an SMTP response. Log in all cases, using a one-line format. For sender
962 callouts, give a full response to the caller, but for recipient callouts,
963 don't give the IP address because this may be an internal host whose identity
964 is not to be widely broadcast. */
965
966 no_conn:
967 switch(errno)
968 {
969 case ETIMEDOUT:
970 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
971 sx.send_quit = FALSE;
972 break;
973
974 #ifdef SUPPORT_I18N
975 case ERRNO_UTF8_FWD:
976 {
977 extern int acl_where; /* src/acl.c */
978 errno = 0;
979 addr->message = string_sprintf(
980 "response to \"EHLO\" did not include SMTPUTF8");
981 addr->user_message = acl_where == ACL_WHERE_RCPT
982 ? US"533 no support for internationalised mailbox name"
983 : US"550 mailbox unavailable";
984 yield = FAIL;
985 done = TRUE;
986 }
987 break;
988 #endif
989 case ECONNREFUSED:
990 sx.send_quit = FALSE;
991 break;
992
993 case 0:
994 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
995
996 /*XXX test here is ugly; seem to have a split of responsibility for
997 building this message. Need to rationalise. Where is it done
998 before here, and when not?
999 Not == 5xx resp to MAIL on main-verify
1000 */
1001 if (!addr->message) addr->message =
1002 string_sprintf("response to \"%s\" was: %s",
1003 big_buffer, string_printing(sx.buffer));
1004
1005 addr->user_message = options & vopt_is_recipient
1006 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
1007 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1008 host->address, big_buffer, sx.buffer);
1009
1010 /* Hard rejection ends the process */
1011
1012 if (sx.buffer[0] == '5') /* Address rejected */
1013 {
1014 yield = FAIL;
1015 done = TRUE;
1016 }
1017 break;
1018 }
1019
1020 /* End the SMTP conversation and close the connection. */
1021
1022 /* Cutthrough - on a successful connect and recipient-verify with
1023 use-sender and we are 1st rcpt and have no cutthrough conn so far
1024 here is where we want to leave the conn open. Ditto for a lazy-close
1025 verify. */
1026
1027 if (cutthrough.delivery)
1028 {
1029 if (addr->transport->filter_command)
1030 {
1031 cutthrough.delivery= FALSE;
1032 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
1033 }
1034 #ifndef DISABLE_DKIM
1035 if (ob->dkim.dkim_domain)
1036 {
1037 cutthrough.delivery= FALSE;
1038 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
1039 }
1040 #endif
1041 #ifdef EXPERIMENTAL_ARC
1042 if (ob->arc_sign)
1043 {
1044 cutthrough.delivery= FALSE;
1045 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of ARC signing\n");
1046 }
1047 #endif
1048 }
1049
1050 if ( (cutthrough.delivery || options & vopt_callout_hold)
1051 && rcpt_count == 1
1052 && done
1053 && yield == OK
1054 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1055 == vopt_callout_recipsender
1056 && !random_local_part
1057 && !pm_mailfrom
1058 && cutthrough.cctx.sock < 0
1059 && !sx.lmtp
1060 )
1061 {
1062 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for %s\n",
1063 cutthrough.delivery
1064 ? "cutthrough delivery" : "potential further verifies and delivery");
1065
1066 cutthrough.callout_hold_only = !cutthrough.delivery;
1067 cutthrough.is_tls = tls_out.active.sock >= 0;
1068 /* We assume no buffer in use in the outblock */
1069 cutthrough.cctx = sx.cctx;
1070 cutthrough.nrcpt = 1;
1071 cutthrough.transport = addr->transport->name;
1072 cutthrough.interface = interface;
1073 cutthrough.snd_port = sending_port;
1074 cutthrough.peer_options = smtp_peer_options;
1075 cutthrough.host = *host;
1076 {
1077 int oldpool = store_pool;
1078 store_pool = POOL_PERM;
1079 cutthrough.snd_ip = string_copy(sending_ip_address);
1080 cutthrough.host.name = string_copy(host->name);
1081 cutthrough.host.address = string_copy(host->address);
1082 store_pool = oldpool;
1083 }
1084
1085 /* Save the address_item and parent chain for later logging */
1086 cutthrough.addr = *addr;
1087 cutthrough.addr.next = NULL;
1088 cutthrough.addr.host_used = &cutthrough.host;
1089 for (address_item * caddr = &cutthrough.addr, * parent = addr->parent;
1090 parent;
1091 caddr = caddr->parent, parent = parent->parent)
1092 *(caddr->parent = store_get(sizeof(address_item))) = *parent;
1093
1094 ctctx.outblock.buffer = ctbuffer;
1095 ctctx.outblock.buffersize = sizeof(ctbuffer);
1096 ctctx.outblock.ptr = ctbuffer;
1097 /* ctctx.outblock.cmd_count = 0; ctctx.outblock.authenticating = FALSE; */
1098 ctctx.outblock.cctx = &cutthrough.cctx;
1099 }
1100 else
1101 {
1102 /* Ensure no cutthrough on multiple verifies that were incompatible */
1103 if (options & vopt_callout_recipsender)
1104 cancel_cutthrough_connection(TRUE, US"not usable for cutthrough");
1105 if (sx.send_quit)
1106 if (smtp_write_command(&sx, SCMD_FLUSH, "QUIT\r\n") != -1)
1107 /* Wait a short time for response, and discard it */
1108 smtp_read_response(&sx, sx.buffer, sizeof(sx.buffer), '2', 1);
1109
1110 if (sx.cctx.sock >= 0)
1111 {
1112 #ifndef DISABLE_TLS
1113 if (sx.cctx.tls_ctx)
1114 {
1115 tls_close(sx.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
1116 sx.cctx.tls_ctx = NULL;
1117 }
1118 #endif
1119 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1120 (void)close(sx.cctx.sock);
1121 sx.cctx.sock = -1;
1122 #ifndef DISABLE_EVENT
1123 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1124 #endif
1125 }
1126 }
1127
1128 if (!done || yield != OK)
1129 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1130 addr->message);
1131 } /* Loop through all hosts, while !done */
1132 }
1133
1134 /* If we get here with done == TRUE, a successful callout happened, and yield
1135 will be set OK or FAIL according to the response to the RCPT command.
1136 Otherwise, we looped through the hosts but couldn't complete the business.
1137 However, there may be domain-specific information to cache in both cases. */
1138
1139 if (!(options & vopt_callout_no_cache))
1140 cache_callout_write(&new_domain_record, addr->domain,
1141 done, &new_address_record, address_key);
1142
1143 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1144 temporary error. If there was only one host, and a response was received, leave
1145 it alone if supplying details. Otherwise, give a generic response. */
1146
1147 if (!done)
1148 {
1149 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1150 options & vopt_is_recipient ? "recipient" : "sender");
1151 yield = DEFER;
1152
1153 addr->message = host_list->next || !addr->message
1154 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1155
1156 addr->user_message = smtp_return_error_details
1157 ? string_sprintf("%s for <%s>.\n"
1158 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1159 "they may be permanently unreachable from this server. In the latter case,\n%s",
1160 dullmsg, addr->address,
1161 options & vopt_is_recipient
1162 ? "the address will never be accepted."
1163 : "you need to change the address or create an MX record for its domain\n"
1164 "if it is supposed to be generally accessible from the Internet.\n"
1165 "Talk to your mail administrator for details.")
1166 : dullmsg;
1167
1168 /* Force a specific error code */
1169
1170 addr->basic_errno = ERRNO_CALLOUTDEFER;
1171 }
1172
1173 /* Come here from within the cache-reading code on fast-track exit. */
1174
1175 END_CALLOUT:
1176 tls_modify_variables(&tls_in);
1177 return yield;
1178 }
1179
1180
1181
1182 /* Called after recipient-acl to get a cutthrough connection open when
1183 one was requested and a recipient-verify wasn't subsequently done.
1184 */
1185 int
1186 open_cutthrough_connection(address_item * addr)
1187 {
1188 address_item addr2;
1189 int rc;
1190
1191 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1192 /* We must use a copy of the address for verification, because it might
1193 get rewritten. */
1194
1195 addr2 = *addr;
1196 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1197 rcpt_count > 1 ? "more" : "start");
1198 rc = verify_address(&addr2, NULL,
1199 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1200 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1201 NULL, NULL, NULL);
1202 addr->message = addr2.message;
1203 addr->user_message = addr2.user_message;
1204 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1205 return rc;
1206 }
1207
1208
1209
1210 /* Send given number of bytes from the buffer */
1211 static BOOL
1212 cutthrough_send(int n)
1213 {
1214 if(cutthrough.cctx.sock < 0)
1215 return TRUE;
1216
1217 if(
1218 #ifndef DISABLE_TLS
1219 cutthrough.is_tls
1220 ? tls_write(cutthrough.cctx.tls_ctx, ctctx.outblock.buffer, n, FALSE)
1221 :
1222 #endif
1223 send(cutthrough.cctx.sock, ctctx.outblock.buffer, n, 0) > 0
1224 )
1225 {
1226 transport_count += n;
1227 ctctx.outblock.ptr= ctctx.outblock.buffer;
1228 return TRUE;
1229 }
1230
1231 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1232 return FALSE;
1233 }
1234
1235
1236
1237 static BOOL
1238 _cutthrough_puts(uschar * cp, int n)
1239 {
1240 while(n--)
1241 {
1242 if(ctctx.outblock.ptr >= ctctx.outblock.buffer+ctctx.outblock.buffersize)
1243 if(!cutthrough_send(ctctx.outblock.buffersize))
1244 return FALSE;
1245
1246 *ctctx.outblock.ptr++ = *cp++;
1247 }
1248 return TRUE;
1249 }
1250
1251 /* Buffered output of counted data block. Return boolean success */
1252 static BOOL
1253 cutthrough_puts(uschar * cp, int n)
1254 {
1255 if (cutthrough.cctx.sock < 0) return TRUE;
1256 if (_cutthrough_puts(cp, n)) return TRUE;
1257 cancel_cutthrough_connection(TRUE, US"transmit failed");
1258 return FALSE;
1259 }
1260
1261 void
1262 cutthrough_data_puts(uschar * cp, int n)
1263 {
1264 if (cutthrough.delivery) (void) cutthrough_puts(cp, n);
1265 return;
1266 }
1267
1268
1269 static BOOL
1270 _cutthrough_flush_send(void)
1271 {
1272 int n = ctctx.outblock.ptr - ctctx.outblock.buffer;
1273
1274 if(n>0)
1275 if(!cutthrough_send(n))
1276 return FALSE;
1277 return TRUE;
1278 }
1279
1280
1281 /* Send out any bufferred output. Return boolean success. */
1282 BOOL
1283 cutthrough_flush_send(void)
1284 {
1285 if (_cutthrough_flush_send()) return TRUE;
1286 cancel_cutthrough_connection(TRUE, US"transmit failed");
1287 return FALSE;
1288 }
1289
1290
1291 static BOOL
1292 cutthrough_put_nl(void)
1293 {
1294 return cutthrough_puts(US"\r\n", 2);
1295 }
1296
1297
1298 void
1299 cutthrough_data_put_nl(void)
1300 {
1301 cutthrough_data_puts(US"\r\n", 2);
1302 }
1303
1304
1305 /* Get and check response from cutthrough target */
1306 static uschar
1307 cutthrough_response(client_conn_ctx * cctx, char expect, uschar ** copy, int timeout)
1308 {
1309 smtp_context sx = {0};
1310 uschar inbuffer[4096];
1311 uschar responsebuffer[4096];
1312
1313 sx.inblock.buffer = inbuffer;
1314 sx.inblock.buffersize = sizeof(inbuffer);
1315 sx.inblock.ptr = inbuffer;
1316 sx.inblock.ptrend = inbuffer;
1317 sx.inblock.cctx = cctx;
1318 if(!smtp_read_response(&sx, responsebuffer, sizeof(responsebuffer), expect, timeout))
1319 cancel_cutthrough_connection(TRUE, US"target timeout on read");
1320
1321 if(copy)
1322 {
1323 uschar * cp;
1324 *copy = cp = string_copy(responsebuffer);
1325 /* Trim the trailing end of line */
1326 cp += Ustrlen(responsebuffer);
1327 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1328 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1329 }
1330
1331 return responsebuffer[0];
1332 }
1333
1334
1335 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1336 BOOL
1337 cutthrough_predata(void)
1338 {
1339 if(cutthrough.cctx.sock < 0 || cutthrough.callout_hold_only)
1340 return FALSE;
1341
1342 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1343 cutthrough_puts(US"DATA\r\n", 6);
1344 cutthrough_flush_send();
1345
1346 /* Assume nothing buffered. If it was it gets ignored. */
1347 return cutthrough_response(&cutthrough.cctx, '3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1348 }
1349
1350
1351 /* tctx arg only to match write_chunk() */
1352 static BOOL
1353 cutthrough_write_chunk(transport_ctx * tctx, uschar * s, int len)
1354 {
1355 uschar * s2;
1356 while(s && (s2 = Ustrchr(s, '\n')))
1357 {
1358 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1359 return FALSE;
1360 s = s2+1;
1361 }
1362 return TRUE;
1363 }
1364
1365
1366 /* Buffered send of headers. Return success boolean. */
1367 /* Expands newlines to wire format (CR,NL). */
1368 /* Also sends header-terminating blank line. */
1369 BOOL
1370 cutthrough_headers_send(void)
1371 {
1372 transport_ctx tctx;
1373
1374 if(cutthrough.cctx.sock < 0 || cutthrough.callout_hold_only)
1375 return FALSE;
1376
1377 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1378 but having a separate buffered-output function (for now)
1379 */
1380 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1381
1382 tctx.u.fd = cutthrough.cctx.sock;
1383 tctx.tblock = cutthrough.addr.transport;
1384 tctx.addr = &cutthrough.addr;
1385 tctx.check_string = US".";
1386 tctx.escape_string = US"..";
1387 /*XXX check under spool_files_wireformat. Might be irrelevant */
1388 tctx.options = topt_use_crlf;
1389
1390 if (!transport_headers_send(&tctx, &cutthrough_write_chunk))
1391 return FALSE;
1392
1393 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1394 return TRUE;
1395 }
1396
1397
1398 static void
1399 close_cutthrough_connection(const uschar * why)
1400 {
1401 int fd = cutthrough.cctx.sock;
1402 if(fd >= 0)
1403 {
1404 /* We could be sending this after a bunch of data, but that is ok as
1405 the only way to cancel the transfer in dataphase is to drop the tcp
1406 conn before the final dot.
1407 */
1408 client_conn_ctx tmp_ctx = cutthrough.cctx;
1409 ctctx.outblock.ptr = ctbuffer;
1410 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1411 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1412 _cutthrough_flush_send();
1413 cutthrough.cctx.sock = -1; /* avoid recursion via read timeout */
1414 cutthrough.nrcpt = 0; /* permit re-cutthrough on subsequent message */
1415
1416 /* Wait a short time for response, and discard it */
1417 cutthrough_response(&tmp_ctx, '2', NULL, 1);
1418
1419 #ifndef DISABLE_TLS
1420 if (cutthrough.is_tls)
1421 {
1422 tls_close(cutthrough.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
1423 cutthrough.cctx.tls_ctx = NULL;
1424 cutthrough.is_tls = FALSE;
1425 }
1426 #endif
1427 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1428 (void)close(fd);
1429 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1430 }
1431 ctctx.outblock.ptr = ctbuffer;
1432 }
1433
1434 void
1435 cancel_cutthrough_connection(BOOL close_noncutthrough_verifies, const uschar * why)
1436 {
1437 if (cutthrough.delivery || close_noncutthrough_verifies)
1438 close_cutthrough_connection(why);
1439 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1440 }
1441
1442
1443 void
1444 release_cutthrough_connection(const uschar * why)
1445 {
1446 if (cutthrough.cctx.sock < 0) return;
1447 HDEBUG(D_acl) debug_printf_indent("release cutthrough conn: %s\n", why);
1448 cutthrough.cctx.sock = -1;
1449 cutthrough.cctx.tls_ctx = NULL;
1450 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1451 }
1452
1453
1454
1455
1456 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1457 Log an OK response as a transmission.
1458 Close the connection.
1459 Return smtp response-class digit.
1460 */
1461 uschar *
1462 cutthrough_finaldot(void)
1463 {
1464 uschar res;
1465 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1466
1467 /* Assume data finshed with new-line */
1468 if( !cutthrough_puts(US".", 1)
1469 || !cutthrough_put_nl()
1470 || !cutthrough_flush_send()
1471 )
1472 return cutthrough.addr.message;
1473
1474 res = cutthrough_response(&cutthrough.cctx, '2', &cutthrough.addr.message,
1475 CUTTHROUGH_DATA_TIMEOUT);
1476 for (address_item * addr = &cutthrough.addr; addr; addr = addr->next)
1477 {
1478 addr->message = cutthrough.addr.message;
1479 switch(res)
1480 {
1481 case '2':
1482 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1483 close_cutthrough_connection(US"delivered");
1484 break;
1485
1486 case '4':
1487 delivery_log(LOG_MAIN, addr, 0,
1488 US"tmp-reject from cutthrough after DATA:");
1489 break;
1490
1491 case '5':
1492 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1493 US"rejected after DATA:");
1494 break;
1495
1496 default:
1497 break;
1498 }
1499 }
1500 return cutthrough.addr.message;
1501 }
1502
1503
1504
1505 /*************************************************
1506 * Copy error to toplevel address *
1507 *************************************************/
1508
1509 /* This function is used when a verify fails or defers, to ensure that the
1510 failure or defer information is in the original toplevel address. This applies
1511 when an address is redirected to a single new address, and the failure or
1512 deferral happens to the child address.
1513
1514 Arguments:
1515 vaddr the verify address item
1516 addr the final address item
1517 yield FAIL or DEFER
1518
1519 Returns: the value of YIELD
1520 */
1521
1522 static int
1523 copy_error(address_item *vaddr, address_item *addr, int yield)
1524 {
1525 if (addr != vaddr)
1526 {
1527 vaddr->message = addr->message;
1528 vaddr->user_message = addr->user_message;
1529 vaddr->basic_errno = addr->basic_errno;
1530 vaddr->more_errno = addr->more_errno;
1531 vaddr->prop.address_data = addr->prop.address_data;
1532 copyflag(vaddr, addr, af_pass_message);
1533 }
1534 return yield;
1535 }
1536
1537
1538
1539
1540 /**************************************************
1541 * printf that automatically handles TLS if needed *
1542 ***************************************************/
1543
1544 /* This function is used by verify_address() as a substitute for all fprintf()
1545 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1546 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1547 that assumes that we always use the smtp_out FILE* when not using TLS or the
1548 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1549 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1550 fprintf().
1551
1552 Arguments:
1553 f the candidate FILE* to write to
1554 format format string
1555 ... optional arguments
1556
1557 Returns:
1558 nothing
1559 */
1560
1561 static void PRINTF_FUNCTION(2,3)
1562 respond_printf(FILE *f, const char *format, ...)
1563 {
1564 va_list ap;
1565
1566 va_start(ap, format);
1567 if (smtp_out && (f == smtp_out))
1568 smtp_vprintf(format, FALSE, ap);
1569 else
1570 vfprintf(f, format, ap);
1571 va_end(ap);
1572 }
1573
1574
1575
1576 /*************************************************
1577 * Verify an email address *
1578 *************************************************/
1579
1580 /* This function is used both for verification (-bv and at other times) and
1581 address testing (-bt), which is indicated by address_test_mode being set.
1582
1583 Arguments:
1584 vaddr contains the address to verify; the next field in this block
1585 must be NULL
1586 f if not NULL, write the result to this file
1587 options various option bits:
1588 vopt_fake_sender => this sender verify is not for the real
1589 sender (it was verify=sender=xxxx or an address from a
1590 header line) - rewriting must not change sender_address
1591 vopt_is_recipient => this is a recipient address, otherwise
1592 it's a sender address - this affects qualification and
1593 rewriting and messages from callouts
1594 vopt_qualify => qualify an unqualified address; else error
1595 vopt_expn => called from SMTP EXPN command
1596 vopt_success_on_redirect => when a new address is generated
1597 the verification instantly succeeds
1598
1599 These ones are used by do_callout() -- the options variable
1600 is passed to it.
1601
1602 vopt_callout_fullpm => if postmaster check, do full one
1603 vopt_callout_no_cache => don't use callout cache
1604 vopt_callout_random => do the "random" thing
1605 vopt_callout_recipsender => use real sender for recipient
1606 vopt_callout_recippmaster => use postmaster for recipient
1607
1608 callout if > 0, specifies that callout is required, and gives timeout
1609 for individual commands
1610 callout_overall if > 0, gives overall timeout for the callout function;
1611 if < 0, a default is used (see do_callout())
1612 callout_connect the connection timeout for callouts
1613 se_mailfrom when callout is requested to verify a sender, use this
1614 in MAIL FROM; NULL => ""
1615 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1616 thing and use this as the sender address (may be "")
1617
1618 routed if not NULL, set TRUE if routing succeeded, so we can
1619 distinguish between routing failed and callout failed
1620
1621 Returns: OK address verified
1622 FAIL address failed to verify
1623 DEFER can't tell at present
1624 */
1625
1626 int
1627 verify_address(address_item * vaddr, FILE * fp, int options, int callout,
1628 int callout_overall, int callout_connect, uschar * se_mailfrom,
1629 uschar *pm_mailfrom, BOOL *routed)
1630 {
1631 BOOL allok = TRUE;
1632 BOOL full_info = fp ? debug_selector != 0 : FALSE;
1633 BOOL expn = (options & vopt_expn) != 0;
1634 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1635 int i;
1636 int yield = OK;
1637 int verify_type = expn? v_expn :
1638 f.address_test_mode? v_none :
1639 options & vopt_is_recipient? v_recipient : v_sender;
1640 address_item *addr_list;
1641 address_item *addr_new = NULL;
1642 address_item *addr_remote = NULL;
1643 address_item *addr_local = NULL;
1644 address_item *addr_succeed = NULL;
1645 uschar **failure_ptr = options & vopt_is_recipient
1646 ? &recipient_verify_failure : &sender_verify_failure;
1647 uschar *ko_prefix, *cr;
1648 uschar *address = vaddr->address;
1649 uschar *save_sender;
1650 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1651
1652 /* Clear, just in case */
1653
1654 *failure_ptr = NULL;
1655
1656 /* Set up a prefix and suffix for error message which allow us to use the same
1657 output statements both in EXPN mode (where an SMTP response is needed) and when
1658 debugging with an output file. */
1659
1660 if (expn)
1661 {
1662 ko_prefix = US"553 ";
1663 cr = US"\r";
1664 }
1665 else ko_prefix = cr = US"";
1666
1667 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1668
1669 if (parse_find_at(address) == NULL)
1670 {
1671 if (!(options & vopt_qualify))
1672 {
1673 if (fp)
1674 respond_printf(fp, "%sA domain is required for \"%s\"%s\n",
1675 ko_prefix, address, cr);
1676 *failure_ptr = US"qualify";
1677 return FAIL;
1678 }
1679 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1680 }
1681
1682 DEBUG(D_verify)
1683 {
1684 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1685 debug_printf("%s %s\n", f.address_test_mode? "Testing" : "Verifying", address);
1686 }
1687
1688 /* Rewrite and report on it. Clear the domain and local part caches - these
1689 may have been set by domains and local part tests during an ACL. */
1690
1691 if (global_rewrite_rules)
1692 {
1693 uschar *old = address;
1694 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1695 global_rewrite_rules, rewrite_existflags);
1696 if (address != old)
1697 {
1698 for (int i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1699 for (int i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1700 if (fp && !expn) fprintf(fp, "Address rewritten as: %s\n", address);
1701 }
1702 }
1703
1704 /* If this is the real sender address, we must update sender_address at
1705 this point, because it may be referred to in the routers. */
1706
1707 if (!(options & (vopt_fake_sender|vopt_is_recipient)))
1708 sender_address = address;
1709
1710 /* If the address was rewritten to <> no verification can be done, and we have
1711 to return OK. This rewriting is permitted only for sender addresses; for other
1712 addresses, such rewriting fails. */
1713
1714 if (!address[0]) return OK;
1715
1716 /* Flip the legacy TLS-related variables over to the outbound set in case
1717 they're used in the context of a transport used by verification. Reset them
1718 at exit from this routine (so no returns allowed from here on). */
1719
1720 tls_modify_variables(&tls_out);
1721
1722 /* Save a copy of the sender address for re-instating if we change it to <>
1723 while verifying a sender address (a nice bit of self-reference there). */
1724
1725 save_sender = sender_address;
1726
1727 /* Observability variable for router/transport use */
1728
1729 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1730
1731 /* Update the address structure with the possibly qualified and rewritten
1732 address. Set it up as the starting address on the chain of new addresses. */
1733
1734 vaddr->address = address;
1735 addr_new = vaddr;
1736
1737 /* We need a loop, because an address can generate new addresses. We must also
1738 cope with generated pipes and files at the top level. (See also the code and
1739 comment in deliver.c.) However, it is usually the case that the router for
1740 user's .forward files has its verify flag turned off.
1741
1742 If an address generates more than one child, the loop is used only when
1743 full_info is set, and this can only be set locally. Remote enquiries just get
1744 information about the top level address, not anything that it generated. */
1745
1746 while (addr_new)
1747 {
1748 int rc;
1749 address_item *addr = addr_new;
1750
1751 addr_new = addr->next;
1752 addr->next = NULL;
1753
1754 DEBUG(D_verify)
1755 {
1756 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1757 debug_printf("Considering %s\n", addr->address);
1758 }
1759
1760 /* Handle generated pipe, file or reply addresses. We don't get these
1761 when handling EXPN, as it does only one level of expansion. */
1762
1763 if (testflag(addr, af_pfr))
1764 {
1765 allok = FALSE;
1766 if (fp)
1767 {
1768 BOOL allow;
1769
1770 if (addr->address[0] == '>')
1771 {
1772 allow = testflag(addr, af_allow_reply);
1773 fprintf(fp, "%s -> mail %s", addr->parent->address, addr->address + 1);
1774 }
1775 else
1776 {
1777 allow = addr->address[0] == '|'
1778 ? testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1779 fprintf(fp, "%s -> %s", addr->parent->address, addr->address);
1780 }
1781
1782 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1783 fprintf(fp, "\n*** Error in setting up pipe, file, or autoreply:\n"
1784 "%s\n", addr->message);
1785 else if (allow)
1786 fprintf(fp, "\n transport = %s\n", addr->transport->name);
1787 else
1788 fprintf(fp, " *** forbidden ***\n");
1789 }
1790 continue;
1791 }
1792
1793 /* Just in case some router parameter refers to it. */
1794
1795 return_path = addr->prop.errors_address
1796 ? addr->prop.errors_address : sender_address;
1797
1798 /* Split the address into domain and local part, handling the %-hack if
1799 necessary, and then route it. While routing a sender address, set
1800 $sender_address to <> because that is what it will be if we were trying to
1801 send a bounce to the sender. */
1802
1803 if (routed) *routed = FALSE;
1804 if ((rc = deliver_split_address(addr)) == OK)
1805 {
1806 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1807 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1808 &addr_succeed, verify_type);
1809 sender_address = save_sender; /* Put back the real sender */
1810 }
1811
1812 /* If routing an address succeeded, set the flag that remembers, for use when
1813 an ACL cached a sender verify (in case a callout fails). Then if routing set
1814 up a list of hosts or the transport has a host list, and the callout option
1815 is set, and we aren't in a host checking run, do the callout verification,
1816 and set another flag that notes that a callout happened. */
1817
1818 if (rc == OK)
1819 {
1820 if (routed) *routed = TRUE;
1821 if (callout > 0)
1822 {
1823 transport_instance * tp;
1824 host_item * host_list = addr->host_list;
1825
1826 /* Make up some data for use in the case where there is no remote
1827 transport. */
1828
1829 transport_feedback tf = {
1830 .interface = NULL, /* interface (=> any) */
1831 .port = US"smtp",
1832 .protocol = US"smtp",
1833 .hosts = NULL,
1834 .helo_data = US"$smtp_active_hostname",
1835 .hosts_override = FALSE,
1836 .hosts_randomize = FALSE,
1837 .gethostbyname = FALSE,
1838 .qualify_single = TRUE,
1839 .search_parents = FALSE
1840 };
1841
1842 /* If verification yielded a remote transport, we want to use that
1843 transport's options, so as to mimic what would happen if we were really
1844 sending a message to this address. */
1845
1846 if ((tp = addr->transport) && !tp->info->local)
1847 {
1848 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1849
1850 /* If the transport has hosts and the router does not, or if the
1851 transport is configured to override the router's hosts, we must build a
1852 host list of the transport's hosts, and find the IP addresses */
1853
1854 if (tf.hosts && (!host_list || tf.hosts_override))
1855 {
1856 uschar *s;
1857 const uschar *save_deliver_domain = deliver_domain;
1858 uschar *save_deliver_localpart = deliver_localpart;
1859
1860 host_list = NULL; /* Ignore the router's hosts */
1861
1862 deliver_domain = addr->domain;
1863 deliver_localpart = addr->local_part;
1864 s = expand_string(tf.hosts);
1865 deliver_domain = save_deliver_domain;
1866 deliver_localpart = save_deliver_localpart;
1867
1868 if (!s)
1869 {
1870 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1871 "\"%s\" in %s transport for callout: %s", tf.hosts,
1872 tp->name, expand_string_message);
1873 }
1874 else
1875 {
1876 int flags;
1877 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1878
1879 /* Just ignore failures to find a host address. If we don't manage
1880 to find any addresses, the callout will defer. Note that more than
1881 one address may be found for a single host, which will result in
1882 additional host items being inserted into the chain. Hence we must
1883 save the next host first. */
1884
1885 flags = HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
1886 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1887 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1888
1889 for (host_item * host = host_list, * nexthost; host; host = nexthost)
1890 {
1891 nexthost = host->next;
1892 if (tf.gethostbyname ||
1893 string_is_ip_address(host->name, NULL) != 0)
1894 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1895 else
1896 {
1897 const dnssec_domains * dsp = NULL;
1898 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1899 {
1900 smtp_transport_options_block * ob =
1901 (smtp_transport_options_block *) tp->options_block;
1902 dsp = &ob->dnssec;
1903 }
1904
1905 (void) host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1906 dsp, NULL, NULL);
1907 }
1908 }
1909 }
1910 }
1911 }
1912
1913 /* Can only do a callout if we have at least one host! If the callout
1914 fails, it will have set ${sender,recipient}_verify_failure. */
1915
1916 if (host_list)
1917 {
1918 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1919 if (host_checking && !f.host_checking_callout)
1920 {
1921 HDEBUG(D_verify)
1922 debug_printf("... callout omitted by default when host testing\n"
1923 "(Use -bhc if you want the callouts to happen.)\n");
1924 }
1925 else
1926 {
1927 #ifndef DISABLE_TLS
1928 deliver_set_expansions(addr);
1929 #endif
1930 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1931 callout_connect, options, se_mailfrom, pm_mailfrom);
1932 #ifndef DISABLE_TLS
1933 deliver_set_expansions(NULL);
1934 #endif
1935 }
1936 }
1937 else
1938 {
1939 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1940 "transport provided a host list, or transport is not smtp\n");
1941 }
1942 }
1943 }
1944
1945 /* Otherwise, any failure is a routing failure */
1946
1947 else *failure_ptr = US"route";
1948
1949 /* A router may return REROUTED if it has set up a child address as a result
1950 of a change of domain name (typically from widening). In this case we always
1951 want to continue to verify the new child. */
1952
1953 if (rc == REROUTED) continue;
1954
1955 /* Handle hard failures */
1956
1957 if (rc == FAIL)
1958 {
1959 allok = FALSE;
1960 if (fp)
1961 {
1962 address_item *p = addr->parent;
1963
1964 respond_printf(fp, "%s%s %s", ko_prefix,
1965 full_info ? addr->address : address,
1966 f.address_test_mode ? "is undeliverable" : "failed to verify");
1967 if (!expn && f.admin_user)
1968 {
1969 if (addr->basic_errno > 0)
1970 respond_printf(fp, ": %s", strerror(addr->basic_errno));
1971 if (addr->message)
1972 respond_printf(fp, ": %s", addr->message);
1973 }
1974
1975 /* Show parents iff doing full info */
1976
1977 if (full_info) while (p)
1978 {
1979 respond_printf(fp, "%s\n <-- %s", cr, p->address);
1980 p = p->parent;
1981 }
1982 respond_printf(fp, "%s\n", cr);
1983 }
1984 cancel_cutthrough_connection(TRUE, US"routing hard fail");
1985
1986 if (!full_info)
1987 {
1988 yield = copy_error(vaddr, addr, FAIL);
1989 goto out;
1990 }
1991 yield = FAIL;
1992 }
1993
1994 /* Soft failure */
1995
1996 else if (rc == DEFER)
1997 {
1998 allok = FALSE;
1999 if (fp)
2000 {
2001 address_item *p = addr->parent;
2002 respond_printf(fp, "%s%s cannot be resolved at this time", ko_prefix,
2003 full_info? addr->address : address);
2004 if (!expn && f.admin_user)
2005 {
2006 if (addr->basic_errno > 0)
2007 respond_printf(fp, ": %s", strerror(addr->basic_errno));
2008 if (addr->message)
2009 respond_printf(fp, ": %s", addr->message);
2010 else if (addr->basic_errno <= 0)
2011 respond_printf(fp, ": unknown error");
2012 }
2013
2014 /* Show parents iff doing full info */
2015
2016 if (full_info) while (p)
2017 {
2018 respond_printf(fp, "%s\n <-- %s", cr, p->address);
2019 p = p->parent;
2020 }
2021 respond_printf(fp, "%s\n", cr);
2022 }
2023 cancel_cutthrough_connection(TRUE, US"routing soft fail");
2024
2025 if (!full_info)
2026 {
2027 yield = copy_error(vaddr, addr, DEFER);
2028 goto out;
2029 }
2030 if (yield == OK) yield = DEFER;
2031 }
2032
2033 /* If we are handling EXPN, we do not want to continue to route beyond
2034 the top level (whose address is in "address"). */
2035
2036 else if (expn)
2037 {
2038 uschar *ok_prefix = US"250-";
2039
2040 if (!addr_new)
2041 if (!addr_local && !addr_remote)
2042 respond_printf(fp, "250 mail to <%s> is discarded\r\n", address);
2043 else
2044 respond_printf(fp, "250 <%s>\r\n", address);
2045
2046 else do
2047 {
2048 address_item *addr2 = addr_new;
2049 addr_new = addr2->next;
2050 if (!addr_new) ok_prefix = US"250 ";
2051 respond_printf(fp, "%s<%s>\r\n", ok_prefix, addr2->address);
2052 } while (addr_new);
2053 yield = OK;
2054 goto out;
2055 }
2056
2057 /* Successful routing other than EXPN. */
2058
2059 else
2060 {
2061 /* Handle successful routing when short info wanted. Otherwise continue for
2062 other (generated) addresses. Short info is the operational case. Full info
2063 can be requested only when debug_selector != 0 and a file is supplied.
2064
2065 There is a conflict between the use of aliasing as an alternate email
2066 address, and as a sort of mailing list. If an alias turns the incoming
2067 address into just one address (e.g. J.Caesar->jc44) you may well want to
2068 carry on verifying the generated address to ensure it is valid when
2069 checking incoming mail. If aliasing generates multiple addresses, you
2070 probably don't want to do this. Exim therefore treats the generation of
2071 just a single new address as a special case, and continues on to verify the
2072 generated address. */
2073
2074 if ( !full_info /* Stop if short info wanted AND */
2075 && ( ( !addr_new /* No new address OR */
2076 || addr_new->next /* More than one new address OR */
2077 || testflag(addr_new, af_pfr) /* New address is pfr */
2078 )
2079 || /* OR */
2080 ( addr_new /* At least one new address AND */
2081 && success_on_redirect /* success_on_redirect is set */
2082 ) )
2083 )
2084 {
2085 if (fp) fprintf(fp, "%s %s\n",
2086 address, f.address_test_mode ? "is deliverable" : "verified");
2087
2088 /* If we have carried on to verify a child address, we want the value
2089 of $address_data to be that of the child */
2090
2091 vaddr->prop.address_data = addr->prop.address_data;
2092
2093 /* If stopped because more than one new address, cannot cutthrough */
2094
2095 if (addr_new && addr_new->next)
2096 cancel_cutthrough_connection(TRUE, US"multiple addresses from routing");
2097
2098 yield = OK;
2099 goto out;
2100 }
2101 }
2102 } /* Loop for generated addresses */
2103
2104 /* Display the full results of the successful routing, including any generated
2105 addresses. Control gets here only when full_info is set, which requires fp not
2106 to be NULL, and this occurs only when a top-level verify is called with the
2107 debugging switch on.
2108
2109 If there are no local and no remote addresses, and there were no pipes, files,
2110 or autoreplies, and there were no errors or deferments, the message is to be
2111 discarded, usually because of the use of :blackhole: in an alias file. */
2112
2113 if (allok && !addr_local && !addr_remote)
2114 {
2115 fprintf(fp, "mail to %s is discarded\n", address);
2116 goto out;
2117 }
2118
2119 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2120 while (addr_list)
2121 {
2122 address_item *addr = addr_list;
2123 transport_instance * tp = addr->transport;
2124
2125 addr_list = addr->next;
2126
2127 fprintf(fp, "%s", CS addr->address);
2128 #ifdef EXPERIMENTAL_SRS
2129 if(addr->prop.srs_sender)
2130 fprintf(fp, " [srs = %s]", addr->prop.srs_sender);
2131 #endif
2132
2133 /* If the address is a duplicate, show something about it. */
2134
2135 if (!testflag(addr, af_pfr))
2136 {
2137 tree_node *tnode;
2138 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2139 fprintf(fp, " [duplicate, would not be delivered]");
2140 else tree_add_duplicate(addr->unique, addr);
2141 }
2142
2143 /* Now show its parents */
2144
2145 for (address_item * p = addr->parent; p; p = p->parent)
2146 fprintf(fp, "\n <-- %s", p->address);
2147 fprintf(fp, "\n ");
2148
2149 /* Show router, and transport */
2150
2151 fprintf(fp, "router = %s, transport = %s\n",
2152 addr->router->name, tp ? tp->name : US"unset");
2153
2154 /* Show any hosts that are set up by a router unless the transport
2155 is going to override them; fiddle a bit to get a nice format. */
2156
2157 if (addr->host_list && tp && !tp->overrides_hosts)
2158 {
2159 int maxlen = 0;
2160 int maxaddlen = 0;
2161 for (host_item * h = addr->host_list; h; h = h->next)
2162 { /* get max lengths of host names, addrs */
2163 int len = Ustrlen(h->name);
2164 if (len > maxlen) maxlen = len;
2165 len = h->address ? Ustrlen(h->address) : 7;
2166 if (len > maxaddlen) maxaddlen = len;
2167 }
2168 for (host_item * h = addr->host_list; h; h = h->next)
2169 {
2170 fprintf(fp, " host %-*s ", maxlen, h->name);
2171
2172 if (h->address)
2173 fprintf(fp, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2174 else if (tp->info->local)
2175 fprintf(fp, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2176 else
2177 fprintf(fp, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2178
2179 if (h->mx >= 0) fprintf(fp, " MX=%d", h->mx);
2180 if (h->port != PORT_NONE) fprintf(fp, " port=%d", h->port);
2181 if (f.running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", fp);
2182 if (h->status == hstatus_unusable) fputs(" ** unusable **", fp);
2183 fputc('\n', fp);
2184 }
2185 }
2186 }
2187
2188 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2189 the -bv or -bt case). */
2190
2191 out:
2192 verify_mode = NULL;
2193 tls_modify_variables(&tls_in);
2194
2195 return yield;
2196 }
2197
2198
2199
2200
2201 /*************************************************
2202 * Check headers for syntax errors *
2203 *************************************************/
2204
2205 /* This function checks those header lines that contain addresses, and verifies
2206 that all the addresses therein are 5322-syntactially correct.
2207
2208 Arguments:
2209 msgptr where to put an error message
2210
2211 Returns: OK
2212 FAIL
2213 */
2214
2215 int
2216 verify_check_headers(uschar **msgptr)
2217 {
2218 uschar *colon, *s;
2219 int yield = OK;
2220
2221 for (header_line * h = header_list; h && yield == OK; h = h->next)
2222 {
2223 if (h->type != htype_from &&
2224 h->type != htype_reply_to &&
2225 h->type != htype_sender &&
2226 h->type != htype_to &&
2227 h->type != htype_cc &&
2228 h->type != htype_bcc)
2229 continue;
2230
2231 colon = Ustrchr(h->text, ':');
2232 s = colon + 1;
2233 while (isspace(*s)) s++;
2234
2235 /* Loop for multiple addresses in the header, enabling group syntax. Note
2236 that we have to reset this after the header has been scanned. */
2237
2238 f.parse_allow_group = TRUE;
2239
2240 while (*s)
2241 {
2242 uschar *ss = parse_find_address_end(s, FALSE);
2243 uschar *recipient, *errmess;
2244 int terminator = *ss;
2245 int start, end, domain;
2246
2247 /* Temporarily terminate the string at this point, and extract the
2248 operative address within, allowing group syntax. */
2249
2250 *ss = 0;
2251 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2252 *ss = terminator;
2253
2254 /* Permit an unqualified address only if the message is local, or if the
2255 sending host is configured to be permitted to send them. */
2256
2257 if (recipient && !domain)
2258 {
2259 if (h->type == htype_from || h->type == htype_sender)
2260 {
2261 if (!f.allow_unqualified_sender) recipient = NULL;
2262 }
2263 else
2264 {
2265 if (!f.allow_unqualified_recipient) recipient = NULL;
2266 }
2267 if (recipient == NULL) errmess = US"unqualified address not permitted";
2268 }
2269
2270 /* It's an error if no address could be extracted, except for the special
2271 case of an empty address. */
2272
2273 if (!recipient && Ustrcmp(errmess, "empty address") != 0)
2274 {
2275 uschar *verb = US"is";
2276 uschar *t = ss;
2277 uschar *tt = colon;
2278 int len;
2279
2280 /* Arrange not to include any white space at the end in the
2281 error message or the header name. */
2282
2283 while (t > s && isspace(t[-1])) t--;
2284 while (tt > h->text && isspace(tt[-1])) tt--;
2285
2286 /* Add the address that failed to the error message, since in a
2287 header with very many addresses it is sometimes hard to spot
2288 which one is at fault. However, limit the amount of address to
2289 quote - cases have been seen where, for example, a missing double
2290 quote in a humungous To: header creates an "address" that is longer
2291 than string_sprintf can handle. */
2292
2293 len = t - s;
2294 if (len > 1024)
2295 {
2296 len = 1024;
2297 verb = US"begins";
2298 }
2299
2300 /* deconst cast ok as we're passing a non-const to string_printing() */
2301 *msgptr = US string_printing(
2302 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2303 errmess, (int)(tt - h->text), h->text, verb, len, s));
2304
2305 yield = FAIL;
2306 break; /* Out of address loop */
2307 }
2308
2309 /* Advance to the next address */
2310
2311 s = ss + (terminator ? 1 : 0);
2312 while (isspace(*s)) s++;
2313 } /* Next address */
2314
2315 f.parse_allow_group = FALSE;
2316 f.parse_found_group = FALSE;
2317 } /* Next header unless yield has been set FALSE */
2318
2319 return yield;
2320 }
2321
2322
2323 /*************************************************
2324 * Check header names for 8-bit characters *
2325 *************************************************/
2326
2327 /* This function checks for invalid characters in header names. See
2328 RFC 5322, 2.2. and RFC 6532, 3.
2329
2330 Arguments:
2331 msgptr where to put an error message
2332
2333 Returns: OK
2334 FAIL
2335 */
2336
2337 int
2338 verify_check_header_names_ascii(uschar **msgptr)
2339 {
2340 uschar *colon;
2341
2342 for (header_line * h = header_list; h; h = h->next)
2343 {
2344 colon = Ustrchr(h->text, ':');
2345 for(uschar * s = h->text; s < colon; s++)
2346 if ((*s < 33) || (*s > 126))
2347 {
2348 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2349 colon - h->text, h->text);
2350 return FAIL;
2351 }
2352 }
2353 return OK;
2354 }
2355
2356 /*************************************************
2357 * Check for blind recipients *
2358 *************************************************/
2359
2360 /* This function checks that every (envelope) recipient is mentioned in either
2361 the To: or Cc: header lines, thus detecting blind carbon copies.
2362
2363 There are two ways of scanning that could be used: either scan the header lines
2364 and tick off the recipients, or scan the recipients and check the header lines.
2365 The original proposed patch did the former, but I have chosen to do the latter,
2366 because (a) it requires no memory and (b) will use fewer resources when there
2367 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2368
2369 Arguments: case_sensitive true if case sensitive matching should be used
2370 Returns: OK if there are no blind recipients
2371 FAIL if there is at least one blind recipient
2372 */
2373
2374 int
2375 verify_check_notblind(BOOL case_sensitive)
2376 {
2377 for (int i = 0; i < recipients_count; i++)
2378 {
2379 BOOL found = FALSE;
2380 uschar *address = recipients_list[i].address;
2381
2382 for (header_line * h = header_list; !found && h; h = h->next)
2383 {
2384 uschar *colon, *s;
2385
2386 if (h->type != htype_to && h->type != htype_cc) continue;
2387
2388 colon = Ustrchr(h->text, ':');
2389 s = colon + 1;
2390 while (isspace(*s)) s++;
2391
2392 /* Loop for multiple addresses in the header, enabling group syntax. Note
2393 that we have to reset this after the header has been scanned. */
2394
2395 f.parse_allow_group = TRUE;
2396
2397 while (*s)
2398 {
2399 uschar * ss = parse_find_address_end(s, FALSE);
2400 uschar * recipient, * errmess;
2401 int terminator = *ss;
2402 int start, end, domain;
2403
2404 /* Temporarily terminate the string at this point, and extract the
2405 operative address within, allowing group syntax. */
2406
2407 *ss = 0;
2408 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2409 *ss = terminator;
2410
2411 /* If we found a valid recipient that has a domain, compare it with the
2412 envelope recipient. Local parts are compared with case-sensitivity
2413 according to the routine arg, domains case-insensitively.
2414 By comparing from the start with length "domain", we include the "@" at
2415 the end, which ensures that we are comparing the whole local part of each
2416 address. */
2417
2418 if (recipient && domain != 0)
2419 if ((found = (case_sensitive
2420 ? Ustrncmp(recipient, address, domain) == 0
2421 : strncmpic(recipient, address, domain) == 0)
2422 && strcmpic(recipient + domain, address + domain) == 0))
2423 break;
2424
2425 /* Advance to the next address */
2426
2427 s = ss + (terminator ? 1:0);
2428 while (isspace(*s)) s++;
2429 } /* Next address */
2430
2431 f.parse_allow_group = FALSE;
2432 f.parse_found_group = FALSE;
2433 } /* Next header (if found is false) */
2434
2435 if (!found) return FAIL;
2436 } /* Next recipient */
2437
2438 return OK;
2439 }
2440
2441
2442
2443 /*************************************************
2444 * Find if verified sender *
2445 *************************************************/
2446
2447 /* Usually, just a single address is verified as the sender of the message.
2448 However, Exim can be made to verify other addresses as well (often related in
2449 some way), and this is useful in some environments. There may therefore be a
2450 chain of such addresses that have previously been tested. This function finds
2451 whether a given address is on the chain.
2452
2453 Arguments: the address to be verified
2454 Returns: pointer to an address item, or NULL
2455 */
2456
2457 address_item *
2458 verify_checked_sender(uschar *sender)
2459 {
2460 for (address_item * addr = sender_verified_list; addr; addr = addr->next)
2461 if (Ustrcmp(sender, addr->address) == 0) return addr;
2462 return NULL;
2463 }
2464
2465
2466
2467
2468
2469 /*************************************************
2470 * Get valid header address *
2471 *************************************************/
2472
2473 /* Scan the originator headers of the message, looking for an address that
2474 verifies successfully. RFC 822 says:
2475
2476 o The "Sender" field mailbox should be sent notices of
2477 any problems in transport or delivery of the original
2478 messages. If there is no "Sender" field, then the
2479 "From" field mailbox should be used.
2480
2481 o If the "Reply-To" field exists, then the reply should
2482 go to the addresses indicated in that field and not to
2483 the address(es) indicated in the "From" field.
2484
2485 So we check a Sender field if there is one, else a Reply_to field, else a From
2486 field. As some strange messages may have more than one of these fields,
2487 especially if they are resent- fields, check all of them if there is more than
2488 one.
2489
2490 Arguments:
2491 user_msgptr points to where to put a user error message
2492 log_msgptr points to where to put a log error message
2493 callout timeout for callout check (passed to verify_address())
2494 callout_overall overall callout timeout (ditto)
2495 callout_connect connect callout timeout (ditto)
2496 se_mailfrom mailfrom for verify; NULL => ""
2497 pm_mailfrom sender for pm callout check (passed to verify_address())
2498 options callout options (passed to verify_address())
2499 verrno where to put the address basic_errno
2500
2501 If log_msgptr is set to something without setting user_msgptr, the caller
2502 normally uses log_msgptr for both things.
2503
2504 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2505 FAIL is given if no appropriate headers are found
2506 */
2507
2508 int
2509 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2510 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2511 uschar *pm_mailfrom, int options, int *verrno)
2512 {
2513 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2514 BOOL done = FALSE;
2515 int yield = FAIL;
2516
2517 for (int i = 0; i < 3 && !done; i++)
2518 for (header_line * h = header_list; h != NULL && !done; h = h->next)
2519 {
2520 int terminator, new_ok;
2521 uschar *s, *ss, *endname;
2522
2523 if (h->type != header_types[i]) continue;
2524 s = endname = Ustrchr(h->text, ':') + 1;
2525
2526 /* Scan the addresses in the header, enabling group syntax. Note that we
2527 have to reset this after the header has been scanned. */
2528
2529 f.parse_allow_group = TRUE;
2530
2531 while (*s != 0)
2532 {
2533 address_item *vaddr;
2534
2535 while (isspace(*s) || *s == ',') s++;
2536 if (*s == 0) break; /* End of header */
2537
2538 ss = parse_find_address_end(s, FALSE);
2539
2540 /* The terminator is a comma or end of header, but there may be white
2541 space preceding it (including newline for the last address). Move back
2542 past any white space so we can check against any cached envelope sender
2543 address verifications. */
2544
2545 while (isspace(ss[-1])) ss--;
2546 terminator = *ss;
2547 *ss = 0;
2548
2549 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2550 (int)(endname - h->text), h->text, s);
2551
2552 /* See if we have already verified this address as an envelope sender,
2553 and if so, use the previous answer. */
2554
2555 vaddr = verify_checked_sender(s);
2556
2557 if (vaddr != NULL && /* Previously checked */
2558 (callout <= 0 || /* No callout needed; OR */
2559 vaddr->special_action > 256)) /* Callout was done */
2560 {
2561 new_ok = vaddr->special_action & 255;
2562 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2563 *ss = terminator; /* Restore shortened string */
2564 }
2565
2566 /* Otherwise we run the verification now. We must restore the shortened
2567 string before running the verification, so the headers are correct, in
2568 case there is any rewriting. */
2569
2570 else
2571 {
2572 int start, end, domain;
2573 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2574 &domain, FALSE);
2575
2576 *ss = terminator;
2577
2578 /* If we found an empty address, just carry on with the next one, but
2579 kill the message. */
2580
2581 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2582 {
2583 *log_msgptr = NULL;
2584 s = ss;
2585 continue;
2586 }
2587
2588 /* If verification failed because of a syntax error, fail this
2589 function, and ensure that the failing address gets added to the error
2590 message. */
2591
2592 if (address == NULL)
2593 {
2594 new_ok = FAIL;
2595 while (ss > s && isspace(ss[-1])) ss--;
2596 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2597 "scanning for sender: %s in \"%.*s\"",
2598 (int)(endname - h->text), h->text, *log_msgptr, (int)(ss - s), s);
2599 yield = FAIL;
2600 done = TRUE;
2601 break;
2602 }
2603
2604 /* Else go ahead with the sender verification. But it isn't *the*
2605 sender of the message, so set vopt_fake_sender to stop sender_address
2606 being replaced after rewriting or qualification. */
2607
2608 else
2609 {
2610 vaddr = deliver_make_addr(address, FALSE);
2611 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2612 callout, callout_overall, callout_connect, se_mailfrom,
2613 pm_mailfrom, NULL);
2614 }
2615 }
2616
2617 /* We now have the result, either newly found, or cached. If we are
2618 giving out error details, set a specific user error. This means that the
2619 last of these will be returned to the user if all three fail. We do not
2620 set a log message - the generic one below will be used. */
2621
2622 if (new_ok != OK)
2623 {
2624 *verrno = vaddr->basic_errno;
2625 if (smtp_return_error_details)
2626 *user_msgptr = string_sprintf("Rejected after DATA: "
2627 "could not verify \"%.*s\" header address\n%s: %s",
2628 (int)(endname - h->text), h->text, vaddr->address, vaddr->message);
2629 }
2630
2631 /* Success or defer */
2632
2633 if (new_ok == OK)
2634 {
2635 yield = OK;
2636 done = TRUE;
2637 break;
2638 }
2639
2640 if (new_ok == DEFER) yield = DEFER;
2641
2642 /* Move on to any more addresses in the header */
2643
2644 s = ss;
2645 } /* Next address */
2646
2647 f.parse_allow_group = FALSE;
2648 f.parse_found_group = FALSE;
2649 } /* Next header, unless done */
2650 /* Next header type unless done */
2651
2652 if (yield == FAIL && *log_msgptr == NULL)
2653 *log_msgptr = US"there is no valid sender in any header line";
2654
2655 if (yield == DEFER && *log_msgptr == NULL)
2656 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2657
2658 return yield;
2659 }
2660
2661
2662
2663
2664 /*************************************************
2665 * Get RFC 1413 identification *
2666 *************************************************/
2667
2668 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2669 the timeout is set to zero, then the query is not done. There may also be lists
2670 of hosts and nets which are exempt. To guard against malefactors sending
2671 non-printing characters which could, for example, disrupt a message's headers,
2672 make sure the string consists of printing characters only.
2673
2674 Argument:
2675 port the port to connect to; usually this is IDENT_PORT (113), but when
2676 running in the test harness with -bh a different value is used.
2677
2678 Returns: nothing
2679
2680 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2681 */
2682
2683 void
2684 verify_get_ident(int port)
2685 {
2686 client_conn_ctx ident_conn_ctx = {0};
2687 int host_af, qlen;
2688 int received_sender_port, received_interface_port, n;
2689 uschar *p;
2690 blob early_data;
2691 uschar buffer[2048];
2692
2693 /* Default is no ident. Check whether we want to do an ident check for this
2694 host. */
2695
2696 sender_ident = NULL;
2697 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2698 return;
2699
2700 DEBUG(D_ident) debug_printf("doing ident callback\n");
2701
2702 /* Set up a connection to the ident port of the remote host. Bind the local end
2703 to the incoming interface address. If the sender host address is an IPv6
2704 address, the incoming interface address will also be IPv6. */
2705
2706 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2707 if ((ident_conn_ctx.sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2708
2709 if (ip_bind(ident_conn_ctx.sock, host_af, interface_address, 0) < 0)
2710 {
2711 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2712 strerror(errno));
2713 goto END_OFF;
2714 }
2715
2716 /* Construct and send the query. */
2717
2718 qlen = snprintf(CS buffer, sizeof(buffer), "%d , %d\r\n",
2719 sender_host_port, interface_port);
2720 early_data.data = buffer;
2721 early_data.len = qlen;
2722
2723 /*XXX we trust that the query is idempotent */
2724 if (ip_connect(ident_conn_ctx.sock, host_af, sender_host_address, port,
2725 rfc1413_query_timeout, &early_data) < 0)
2726 {
2727 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2728 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2729 sender_host_address);
2730 else
2731 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2732 sender_host_address, strerror(errno));
2733 goto END_OFF;
2734 }
2735
2736 /* Read a response line. We put it into the rest of the buffer, using several
2737 recv() calls if necessary. */
2738
2739 p = buffer + qlen;
2740
2741 for (;;)
2742 {
2743 uschar *pp;
2744 int count;
2745 int size = sizeof(buffer) - (p - buffer);
2746
2747 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2748 count = ip_recv(&ident_conn_ctx, p, size, rfc1413_query_timeout);
2749 if (count <= 0) goto END_OFF; /* Read error or EOF */
2750
2751 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2752 generous, and accept a plain \n terminator as well. The only illegal
2753 character is 0. */
2754
2755 for (pp = p; pp < p + count; pp++)
2756 {
2757 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2758 if (*pp == '\n')
2759 {
2760 if (pp[-1] == '\r') pp--;
2761 *pp = 0;
2762 goto GOT_DATA; /* Break out of both loops */
2763 }
2764 }
2765
2766 /* Reached the end of the data without finding \n. Let the loop continue to
2767 read some more, if there is room. */
2768
2769 p = pp;
2770 }
2771
2772 GOT_DATA:
2773
2774 /* We have received a line of data. Check it carefully. It must start with the
2775 same two port numbers that we sent, followed by data as defined by the RFC. For
2776 example,
2777
2778 12345 , 25 : USERID : UNIX :root
2779
2780 However, the amount of white space may be different to what we sent. In the
2781 "osname" field there may be several sub-fields, comma separated. The data we
2782 actually want to save follows the third colon. Some systems put leading spaces
2783 in it - we discard those. */
2784
2785 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2786 &received_interface_port, &n) != 2 ||
2787 received_sender_port != sender_host_port ||
2788 received_interface_port != interface_port)
2789 goto END_OFF;
2790
2791 p = buffer + qlen + n;
2792 while(isspace(*p)) p++;
2793 if (*p++ != ':') goto END_OFF;
2794 while(isspace(*p)) p++;
2795 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2796 p += 6;
2797 while(isspace(*p)) p++;
2798 if (*p++ != ':') goto END_OFF;
2799 while (*p != 0 && *p != ':') p++;
2800 if (*p++ == 0) goto END_OFF;
2801 while(isspace(*p)) p++;
2802 if (*p == 0) goto END_OFF;
2803
2804 /* The rest of the line is the data we want. We turn it into printing
2805 characters when we save it, so that it cannot mess up the format of any logging
2806 or Received: lines into which it gets inserted. We keep a maximum of 127
2807 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2808
2809 sender_ident = US string_printing(string_copyn(p, 127));
2810 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2811
2812 END_OFF:
2813 (void)close(ident_conn_ctx.sock);
2814 return;
2815 }
2816
2817
2818
2819
2820 /*************************************************
2821 * Match host to a single host-list item *
2822 *************************************************/
2823
2824 /* This function compares a host (name or address) against a single item
2825 from a host list. The host name gets looked up if it is needed and is not
2826 already known. The function is called from verify_check_this_host() via
2827 match_check_list(), which is why most of its arguments are in a single block.
2828
2829 Arguments:
2830 arg the argument block (see below)
2831 ss the host-list item
2832 valueptr where to pass back looked up data, or NULL
2833 error for error message when returning ERROR
2834
2835 The block contains:
2836 host_name (a) the host name, or
2837 (b) NULL, implying use sender_host_name and
2838 sender_host_aliases, looking them up if required, or
2839 (c) the empty string, meaning that only IP address matches
2840 are permitted
2841 host_address the host address
2842 host_ipv4 the IPv4 address taken from an IPv6 one
2843
2844 Returns: OK matched
2845 FAIL did not match
2846 DEFER lookup deferred
2847 ERROR (a) failed to find the host name or IP address, or
2848 (b) unknown lookup type specified, or
2849 (c) host name encountered when only IP addresses are
2850 being matched
2851 */
2852
2853 int
2854 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2855 {
2856 check_host_block *cb = (check_host_block *)arg;
2857 int mlen = -1;
2858 int maskoffset;
2859 BOOL iplookup = FALSE;
2860 BOOL isquery = FALSE;
2861 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2862 const uschar *t;
2863 uschar *semicolon;
2864 uschar **aliases;
2865
2866 /* Optimize for the special case when the pattern is "*". */
2867
2868 if (*ss == '*' && ss[1] == 0) return OK;
2869
2870 /* If the pattern is empty, it matches only in the case when there is no host -
2871 this can occur in ACL checking for SMTP input using the -bs option. In this
2872 situation, the host address is the empty string. */
2873
2874 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2875 if (*ss == 0) return FAIL;
2876
2877 /* If the pattern is precisely "@" then match against the primary host name,
2878 provided that host name matching is permitted; if it's "@[]" match against the
2879 local host's IP addresses. */
2880
2881 if (*ss == '@')
2882 {
2883 if (ss[1] == 0)
2884 {
2885 if (isiponly) return ERROR;
2886 ss = primary_hostname;
2887 }
2888 else if (Ustrcmp(ss, "@[]") == 0)
2889 {
2890 for (ip_address_item * ip = host_find_interfaces(); ip; ip = ip->next)
2891 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2892 return FAIL;
2893 }
2894 }
2895
2896 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2897 a (possibly masked) comparison with the current IP address. */
2898
2899 if (string_is_ip_address(ss, &maskoffset) != 0)
2900 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2901
2902 /* The pattern is not an IP address. A common error that people make is to omit
2903 one component of an IPv4 address, either by accident, or believing that, for
2904 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,
2905 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2906 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2907 ancient specification.) To aid in debugging these cases, we give a specific
2908 error if the pattern contains only digits and dots or contains a slash preceded
2909 only by digits and dots (a slash at the start indicates a file name and of
2910 course slashes may be present in lookups, but not preceded only by digits and
2911 dots). */
2912
2913 for (t = ss; isdigit(*t) || *t == '.'; ) t++;
2914 if (*t == 0 || (*t == '/' && t != ss))
2915 {
2916 *error = US"malformed IPv4 address or address mask";
2917 return ERROR;
2918 }
2919
2920 /* See if there is a semicolon in the pattern */
2921
2922 semicolon = Ustrchr(ss, ';');
2923
2924 /* If we are doing an IP address only match, then all lookups must be IP
2925 address lookups, even if there is no "net-". */
2926
2927 if (isiponly)
2928 {
2929 iplookup = semicolon != NULL;
2930 }
2931
2932 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2933 a lookup on a masked IP network, in textual form. We obey this code even if we
2934 have already set iplookup, so as to skip over the "net-" prefix and to set the
2935 mask length. The net- stuff really only applies to single-key lookups where the
2936 key is implicit. For query-style lookups the key is specified in the query.
2937 From release 4.30, the use of net- for query style is no longer needed, but we
2938 retain it for backward compatibility. */
2939
2940 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2941 {
2942 mlen = 0;
2943 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2944 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2945 iplookup = (*t++ == '-');
2946 }
2947 else
2948 t = ss;
2949
2950 /* Do the IP address lookup if that is indeed what we have */
2951
2952 if (iplookup)
2953 {
2954 int insize;
2955 int search_type;
2956 int incoming[4];
2957 void *handle;
2958 uschar *filename, *key, *result;
2959 uschar buffer[64];
2960
2961 /* Find the search type */
2962
2963 search_type = search_findtype(t, semicolon - t);
2964
2965 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2966 search_error_message);
2967
2968 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2969 is no file name, and the "key" is just the query. For query-style with a file
2970 name, we have to fish the file off the start of the query. For a single-key
2971 lookup, the key is the current IP address, masked appropriately, and
2972 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2973 dot separators instead of colons, except when the lookup type is "iplsearch".
2974 */
2975
2976 if (mac_islookup(search_type, lookup_absfilequery))
2977 {
2978 filename = semicolon + 1;
2979 key = filename;
2980 while (*key != 0 && !isspace(*key)) key++;
2981 filename = string_copyn(filename, key - filename);
2982 while (isspace(*key)) key++;
2983 }
2984 else if (mac_islookup(search_type, lookup_querystyle))
2985 {
2986 filename = NULL;
2987 key = semicolon + 1;
2988 }
2989 else /* Single-key style */
2990 {
2991 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2992 ':' : '.';
2993 insize = host_aton(cb->host_address, incoming);
2994 host_mask(insize, incoming, mlen);
2995 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2996 key = buffer;
2997 filename = semicolon + 1;
2998 }
2999
3000 /* Now do the actual lookup; note that there is no search_close() because
3001 of the caching arrangements. */
3002
3003 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
3004 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
3005
3006 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
3007 if (valueptr) *valueptr = result;
3008 return result ? OK : f.search_find_defer ? DEFER: FAIL;
3009 }
3010
3011 /* The pattern is not an IP address or network reference of any kind. That is,
3012 it is a host name pattern. If this is an IP only match, there's an error in the
3013 host list. */
3014
3015 if (isiponly)
3016 {
3017 *error = US"cannot match host name in match_ip list";
3018 return ERROR;
3019 }
3020
3021 /* Check the characters of the pattern to see if they comprise only letters,
3022 digits, full stops, and hyphens (the constituents of domain names). Allow
3023 underscores, as they are all too commonly found. Sigh. Also, if
3024 allow_utf8_domains is set, allow top-bit characters. */
3025
3026 for (t = ss; *t != 0; t++)
3027 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3028 (!allow_utf8_domains || *t < 128)) break;
3029
3030 /* If the pattern is a complete domain name, with no fancy characters, look up
3031 its IP address and match against that. Note that a multi-homed host will add
3032 items to the chain. */
3033
3034 if (*t == 0)
3035 {
3036 int rc;
3037 host_item h;
3038 h.next = NULL;
3039 h.name = ss;
3040 h.address = NULL;
3041 h.mx = MX_NONE;
3042
3043 /* Using byname rather than bydns here means we cannot determine dnssec
3044 status. On the other hand it is unclear how that could be either
3045 propagated up or enforced. */
3046
3047 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3048 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3049 {
3050 for (host_item * hh = &h; hh; hh = hh->next)
3051 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3052 return FAIL;
3053 }
3054 if (rc == HOST_FIND_AGAIN) return DEFER;
3055 *error = string_sprintf("failed to find IP address for %s", ss);
3056 return ERROR;
3057 }
3058
3059 /* Almost all subsequent comparisons require the host name, and can be done
3060 using the general string matching function. When this function is called for
3061 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3062 must use sender_host_name and its aliases, looking them up if necessary. */
3063
3064 if (cb->host_name != NULL) /* Explicit host name given */
3065 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3066 valueptr);
3067
3068 /* Host name not given; in principle we need the sender host name and its
3069 aliases. However, for query-style lookups, we do not need the name if the
3070 query does not contain $sender_host_name. From release 4.23, a reference to
3071 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3072 on spec. */
3073
3074 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3075 {
3076 const uschar *affix;
3077 int partial, affixlen, starflags, id;
3078
3079 *semicolon = 0;
3080 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3081 *semicolon=';';
3082
3083 if (id < 0) /* Unknown lookup type */
3084 {
3085 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3086 search_error_message, ss);
3087 return DEFER;
3088 }
3089 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3090 }
3091
3092 if (isquery)
3093 {
3094 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3095 {
3096 case OK: return OK;
3097 case DEFER: return DEFER;
3098 default: return FAIL;
3099 }
3100 }
3101
3102 /* Not a query-style lookup; must ensure the host name is present, and then we
3103 do a check on the name and all its aliases. */
3104
3105 if (!sender_host_name)
3106 {
3107 HDEBUG(D_host_lookup)
3108 debug_printf("sender host name required, to match against %s\n", ss);
3109 if (host_lookup_failed || host_name_lookup() != OK)
3110 {
3111 *error = string_sprintf("failed to find host name for %s",
3112 sender_host_address);;
3113 return ERROR;
3114 }
3115 host_build_sender_fullhost();
3116 }
3117
3118 /* Match on the sender host name, using the general matching function */
3119
3120 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE, valueptr))
3121 {
3122 case OK: return OK;
3123 case DEFER: return DEFER;
3124 }
3125
3126 /* If there are aliases, try matching on them. */
3127
3128 aliases = sender_host_aliases;
3129 while (*aliases)
3130 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3131 {
3132 case OK: return OK;
3133 case DEFER: return DEFER;
3134 }
3135 return FAIL;
3136 }
3137
3138
3139
3140
3141 /*************************************************
3142 * Check a specific host matches a host list *
3143 *************************************************/
3144
3145 /* This function is passed a host list containing items in a number of
3146 different formats and the identity of a host. Its job is to determine whether
3147 the given host is in the set of hosts defined by the list. The host name is
3148 passed as a pointer so that it can be looked up if needed and not already
3149 known. This is commonly the case when called from verify_check_host() to check
3150 an incoming connection. When called from elsewhere the host name should usually
3151 be set.
3152
3153 This function is now just a front end to match_check_list(), which runs common
3154 code for scanning a list. We pass it the check_host() function to perform a
3155 single test.
3156
3157 Arguments:
3158 listptr pointer to the host list
3159 cache_bits pointer to cache for named lists, or NULL
3160 host_name the host name or NULL, implying use sender_host_name and
3161 sender_host_aliases, looking them up if required
3162 host_address the IP address
3163 valueptr if not NULL, data from a lookup is passed back here
3164
3165 Returns: OK if the host is in the defined set
3166 FAIL if the host is not in the defined set,
3167 DEFER if a data lookup deferred (not a host lookup)
3168
3169 If the host name was needed in order to make a comparison, and could not be
3170 determined from the IP address, the result is FAIL unless the item
3171 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3172
3173 int
3174 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3175 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3176 {
3177 int rc;
3178 unsigned int *local_cache_bits = cache_bits;
3179 const uschar *save_host_address = deliver_host_address;
3180 check_host_block cb = { .host_name = host_name, .host_address = host_address };
3181
3182 if (valueptr) *valueptr = NULL;
3183
3184 /* If the host address starts off ::ffff: it is an IPv6 address in
3185 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3186 addresses. */
3187
3188 cb.host_ipv4 = Ustrncmp(host_address, "::ffff:", 7) == 0
3189 ? host_address + 7 : host_address;
3190
3191 /* During the running of the check, put the IP address into $host_address. In
3192 the case of calls from the smtp transport, it will already be there. However,
3193 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3194 the safe side, any existing setting is preserved, though as I write this
3195 (November 2004) I can't see any cases where it is actually needed. */
3196
3197 deliver_host_address = host_address;
3198 rc = match_check_list(
3199 listptr, /* the list */
3200 0, /* separator character */
3201 &hostlist_anchor, /* anchor pointer */
3202 &local_cache_bits, /* cache pointer */
3203 check_host, /* function for testing */
3204 &cb, /* argument for function */
3205 MCL_HOST, /* type of check */
3206 (host_address == sender_host_address)?
3207 US"host" : host_address, /* text for debugging */
3208 valueptr); /* where to pass back data */
3209 deliver_host_address = save_host_address;
3210 return rc;
3211 }
3212
3213
3214
3215
3216 /*************************************************
3217 * Check the given host item matches a list *
3218 *************************************************/
3219 int
3220 verify_check_given_host(const uschar **listptr, const host_item *host)
3221 {
3222 return verify_check_this_host(listptr, NULL, host->name, host->address, NULL);
3223 }
3224
3225 /*************************************************
3226 * Check the remote host matches a list *
3227 *************************************************/
3228
3229 /* This is a front end to verify_check_this_host(), created because checking
3230 the remote host is a common occurrence. With luck, a good compiler will spot
3231 the tail recursion and optimize it. If there's no host address, this is
3232 command-line SMTP input - check against an empty string for the address.
3233
3234 Arguments:
3235 listptr pointer to the host list
3236
3237 Returns: the yield of verify_check_this_host(),
3238 i.e. OK, FAIL, or DEFER
3239 */
3240
3241 int
3242 verify_check_host(uschar **listptr)
3243 {
3244 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3245 sender_host_address ? sender_host_address : US"", NULL);
3246 }
3247
3248
3249
3250
3251
3252 /*************************************************
3253 * Invert an IP address *
3254 *************************************************/
3255
3256 /* Originally just used for DNS xBL lists, now also used for the
3257 reverse_ip expansion operator.
3258
3259 Arguments:
3260 buffer where to put the answer
3261 address the address to invert
3262 */
3263
3264 void
3265 invert_address(uschar *buffer, uschar *address)
3266 {
3267 int bin[4];
3268 uschar *bptr = buffer;
3269
3270 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3271 to the IPv4 part only. */
3272
3273 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3274
3275 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3276 always 1. */
3277
3278 if (host_aton(address, bin) == 1)
3279 {
3280 int x = bin[0];
3281 for (int i = 0; i < 4; i++)
3282 {
3283 sprintf(CS bptr, "%d.", x & 255);
3284 while (*bptr) bptr++;
3285 x >>= 8;
3286 }
3287 }
3288
3289 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3290 in any DNS black lists, and the format in which they will be looked up is
3291 unknown. This is just a guess. */
3292
3293 #if HAVE_IPV6
3294 else
3295 for (int j = 3; j >= 0; j--)
3296 {
3297 int x = bin[j];
3298 for (int i = 0; i < 8; i++)
3299 {
3300 sprintf(CS bptr, "%x.", x & 15);
3301 while (*bptr) bptr++;
3302 x >>= 4;
3303 }
3304 }
3305 #endif
3306
3307 /* Remove trailing period -- this is needed so that both arbitrary
3308 dnsbl keydomains and inverted addresses may be combined with the
3309 same format string, "%s.%s" */
3310
3311 *(--bptr) = 0;
3312 }
3313
3314
3315
3316 /*************************************************
3317 * Perform a single dnsbl lookup *
3318 *************************************************/
3319
3320 /* This function is called from verify_check_dnsbl() below. It is also called
3321 recursively from within itself when domain and domain_txt are different
3322 pointers, in order to get the TXT record from the alternate domain.
3323
3324 Arguments:
3325 domain the outer dnsbl domain
3326 domain_txt alternate domain to lookup TXT record on success; when the
3327 same domain is to be used, domain_txt == domain (that is,
3328 the pointers must be identical, not just the text)
3329 keydomain the current keydomain (for debug message)
3330 prepend subdomain to lookup (like keydomain, but
3331 reversed if IP address)
3332 iplist the list of matching IP addresses, or NULL for "any"
3333 bitmask true if bitmask matching is wanted
3334 match_type condition for 'succeed' result
3335 0 => Any RR in iplist (=)
3336 1 => No RR in iplist (!=)
3337 2 => All RRs in iplist (==)
3338 3 => Some RRs not in iplist (!==)
3339 the two bits are defined as MT_NOT and MT_ALL
3340 defer_return what to return for a defer
3341
3342 Returns: OK if lookup succeeded
3343 FAIL if not
3344 */
3345
3346 static int
3347 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3348 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3349 int defer_return)
3350 {
3351 dns_answer dnsa;
3352 dns_scan dnss;
3353 tree_node *t;
3354 dnsbl_cache_block *cb;
3355 int old_pool = store_pool;
3356 uschar query[256]; /* DNS domain max length */
3357
3358 /* Construct the specific query domainname */
3359
3360 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3361 {
3362 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3363 "(ignored): %s...", query);
3364 return FAIL;
3365 }
3366
3367 /* Look for this query in the cache. */
3368
3369 if ( (t = tree_search(dnsbl_cache, query))
3370 && (cb = t->data.ptr)->expiry > time(NULL)
3371 )
3372
3373 /* Previous lookup was cached */
3374
3375 {
3376 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3377 }
3378
3379 /* If not cached from a previous lookup, we must do a DNS lookup, and
3380 cache the result in permanent memory. */
3381
3382 else
3383 {
3384 uint ttl = 3600;
3385
3386 store_pool = POOL_PERM;
3387
3388 if (t)
3389 {
3390 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3391 }
3392
3393 else
3394 { /* Set up a tree entry to cache the lookup */
3395 t = store_get(sizeof(tree_node) + Ustrlen(query));
3396 Ustrcpy(t->name, query);
3397 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3398 (void)tree_insertnode(&dnsbl_cache, t);
3399 }
3400
3401 /* Do the DNS lookup . */
3402
3403 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3404 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3405 cb->text_set = FALSE;
3406 cb->text = NULL;
3407 cb->rhs = NULL;
3408
3409 /* If the lookup succeeded, cache the RHS address. The code allows for
3410 more than one address - this was for complete generality and the possible
3411 use of A6 records. However, A6 records are no longer supported. Leave the code
3412 here, just in case.
3413
3414 Quite apart from one A6 RR generating multiple addresses, there are DNS
3415 lists that return more than one A record, so we must handle multiple
3416 addresses generated in that way as well.
3417
3418 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3419 or some suitably far-future time if none were found. */
3420
3421 if (cb->rc == DNS_SUCCEED)
3422 {
3423 dns_address ** addrp = &(cb->rhs);
3424 for (dns_record * rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); rr;
3425 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3426 if (rr->type == T_A)
3427 {
3428 dns_address *da = dns_address_from_rr(&dnsa, rr);
3429 if (da)
3430 {
3431 *addrp = da;
3432 while (da->next) da = da->next;
3433 addrp = &da->next;
3434 if (ttl > rr->ttl) ttl = rr->ttl;
3435 }