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059ec3d9 PH |
1 | /* $Cambridge: exim/src/src/verify.c,v 1.1 2004/10/07 10:39:01 ph10 Exp $ */ |
2 | ||
3 | /************************************************* | |
4 | * Exim - an Internet mail transport agent * | |
5 | *************************************************/ | |
6 | ||
7 | /* Copyright (c) University of Cambridge 1995 - 2004 */ | |
8 | /* See the file NOTICE for conditions of use and distribution. */ | |
9 | ||
10 | /* Functions concerned with verifying things. The original code for callout | |
11 | caching was contributed by Kevin Fleming (but I hacked it around a bit). */ | |
12 | ||
13 | ||
14 | #include "exim.h" | |
15 | ||
16 | ||
17 | /* Structure for caching DNSBL lookups */ | |
18 | ||
19 | typedef struct dnsbl_cache_block { | |
20 | dns_address *rhs; | |
21 | uschar *text; | |
22 | int rc; | |
23 | BOOL text_set; | |
24 | } dnsbl_cache_block; | |
25 | ||
26 | ||
27 | /* Anchor for DNSBL cache */ | |
28 | ||
29 | static tree_node *dnsbl_cache = NULL; | |
30 | ||
31 | ||
32 | ||
33 | /************************************************* | |
34 | * Retrieve a callout cache record * | |
35 | *************************************************/ | |
36 | ||
37 | /* If a record exists, check whether it has expired. | |
38 | ||
39 | Arguments: | |
40 | dbm_file an open hints file | |
41 | key the record key | |
42 | type "address" or "domain" | |
43 | positive_expire expire time for positive records | |
44 | negative_expire expire time for negative records | |
45 | ||
46 | Returns: the cache record if a non-expired one exists, else NULL | |
47 | */ | |
48 | ||
49 | static dbdata_callout_cache * | |
50 | get_callout_cache_record(open_db *dbm_file, uschar *key, uschar *type, | |
51 | int positive_expire, int negative_expire) | |
52 | { | |
53 | BOOL negative; | |
54 | int length, expire; | |
55 | time_t now; | |
56 | dbdata_callout_cache *cache_record; | |
57 | ||
58 | cache_record = dbfn_read_with_length(dbm_file, key, &length); | |
59 | ||
60 | if (cache_record == NULL) | |
61 | { | |
62 | HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type); | |
63 | return NULL; | |
64 | } | |
65 | ||
66 | /* We treat a record as "negative" if its result field is not positive, or if | |
67 | it is a domain record and the postmaster field is negative. */ | |
68 | ||
69 | negative = cache_record->result != ccache_accept || | |
70 | (type[0] == 'd' && cache_record->postmaster_result == ccache_reject); | |
71 | expire = negative? negative_expire : positive_expire; | |
72 | now = time(NULL); | |
73 | ||
74 | if (now - cache_record->time_stamp > expire) | |
75 | { | |
76 | HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type); | |
77 | return NULL; | |
78 | } | |
79 | ||
80 | /* If this is a non-reject domain record, check for the obsolete format version | |
81 | that doesn't have the postmaster and random timestamps, by looking at the | |
82 | length. If so, copy it to a new-style block, replicating the record's | |
83 | timestamp. Then check the additional timestamps. (There's no point wasting | |
84 | effort if connections are rejected.) */ | |
85 | ||
86 | if (type[0] == 'd' && cache_record->result != ccache_reject) | |
87 | { | |
88 | if (length == sizeof(dbdata_callout_cache_obs)) | |
89 | { | |
90 | dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache)); | |
91 | memcpy(new, cache_record, length); | |
92 | new->postmaster_stamp = new->random_stamp = new->time_stamp; | |
93 | cache_record = new; | |
94 | } | |
95 | ||
96 | if (now - cache_record->postmaster_stamp > expire) | |
97 | cache_record->postmaster_result = ccache_unknown; | |
98 | ||
99 | if (now - cache_record->random_stamp > expire) | |
100 | cache_record->random_result = ccache_unknown; | |
101 | } | |
102 | ||
103 | HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type); | |
104 | return cache_record; | |
105 | } | |
106 | ||
107 | ||
108 | ||
109 | /************************************************* | |
110 | * Do callout verification for an address * | |
111 | *************************************************/ | |
112 | ||
113 | /* This function is called from verify_address() when the address has routed to | |
114 | a host list, and a callout has been requested. Callouts are expensive; that is | |
115 | why a cache is used to improve the efficiency. | |
116 | ||
117 | Arguments: | |
118 | addr the address that's been routed | |
119 | host_list the list of hosts to try | |
120 | tf the transport feedback block | |
121 | ||
122 | ifstring "interface" option from transport, or NULL | |
123 | portstring "port" option from transport, or NULL | |
124 | protocolstring "protocol" option from transport, or NULL | |
125 | callout the per-command callout timeout | |
126 | callout_overall the overall callout timeout (if < 0; use 4*callout) | |
127 | options the verification options - these bits are used: | |
128 | vopt_is_recipient => this is a recipient address | |
129 | vopt_callout_no_cache => don't use callout cache | |
130 | vopt_callout_random => do the "random" thing | |
131 | vopt_callout_recipsender => use real sender for recipient | |
132 | vopt_callout_recippmaster => use postmaster for recipient | |
133 | se_mailfrom MAIL FROM address for sender verify; NULL => "" | |
134 | pm_mailfrom if non-NULL, do the postmaster check with this sender | |
135 | ||
136 | Returns: OK/FAIL/DEFER | |
137 | */ | |
138 | ||
139 | static int | |
140 | do_callout(address_item *addr, host_item *host_list, transport_feedback *tf, | |
141 | int callout, int callout_overall, int options, uschar *se_mailfrom, | |
142 | uschar *pm_mailfrom) | |
143 | { | |
144 | BOOL is_recipient = (options & vopt_is_recipient) != 0; | |
145 | BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0; | |
146 | BOOL callout_random = (options & vopt_callout_random) != 0; | |
147 | ||
148 | int yield = OK; | |
149 | BOOL done = FALSE; | |
150 | uschar *address_key; | |
151 | uschar *from_address; | |
152 | uschar *random_local_part = NULL; | |
153 | open_db dbblock; | |
154 | open_db *dbm_file = NULL; | |
155 | dbdata_callout_cache new_domain_record; | |
156 | dbdata_callout_cache_address new_address_record; | |
157 | host_item *host; | |
158 | time_t callout_start_time; | |
159 | ||
160 | new_domain_record.result = ccache_unknown; | |
161 | new_domain_record.postmaster_result = ccache_unknown; | |
162 | new_domain_record.random_result = ccache_unknown; | |
163 | ||
164 | memset(&new_address_record, 0, sizeof(new_address_record)); | |
165 | ||
166 | /* For a recipient callout, the key used for the address cache record must | |
167 | include the sender address if we are using the real sender in the callout, | |
168 | because that may influence the result of the callout. */ | |
169 | ||
170 | address_key = addr->address; | |
171 | from_address = US""; | |
172 | ||
173 | if (is_recipient) | |
174 | { | |
175 | if ((options & vopt_callout_recipsender) != 0) | |
176 | { | |
177 | address_key = string_sprintf("%s/<%s>", addr->address, sender_address); | |
178 | from_address = sender_address; | |
179 | } | |
180 | else if ((options & vopt_callout_recippmaster) != 0) | |
181 | { | |
182 | address_key = string_sprintf("%s/<postmaster@%s>", addr->address, | |
183 | qualify_domain_sender); | |
184 | from_address = string_sprintf("postmaster@%s", qualify_domain_sender); | |
185 | } | |
186 | } | |
187 | ||
188 | /* For a sender callout, we must adjust the key if the mailfrom address is not | |
189 | empty. */ | |
190 | ||
191 | else | |
192 | { | |
193 | from_address = (se_mailfrom == NULL)? US"" : se_mailfrom; | |
194 | if (from_address[0] != 0) | |
195 | address_key = string_sprintf("%s/<%s>", addr->address, from_address); | |
196 | } | |
197 | ||
198 | /* Open the callout cache database, it it exists, for reading only at this | |
199 | stage, unless caching has been disabled. */ | |
200 | ||
201 | if (callout_no_cache) | |
202 | { | |
203 | HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n"); | |
204 | } | |
205 | else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL) | |
206 | { | |
207 | HDEBUG(D_verify) debug_printf("callout cache: not available\n"); | |
208 | } | |
209 | ||
210 | /* If a cache database is available see if we can avoid the need to do an | |
211 | actual callout by making use of previously-obtained data. */ | |
212 | ||
213 | if (dbm_file != NULL) | |
214 | { | |
215 | dbdata_callout_cache_address *cache_address_record; | |
216 | dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file, | |
217 | addr->domain, US"domain", | |
218 | callout_cache_domain_positive_expire, | |
219 | callout_cache_domain_negative_expire); | |
220 | ||
221 | /* If an unexpired cache record was found for this domain, see if the callout | |
222 | process can be short-circuited. */ | |
223 | ||
224 | if (cache_record != NULL) | |
225 | { | |
226 | /* If an early command (up to and including MAIL FROM:<>) was rejected, | |
227 | there is no point carrying on. The callout fails. */ | |
228 | ||
229 | if (cache_record->result == ccache_reject) | |
230 | { | |
231 | setflag(addr, af_verify_nsfail); | |
232 | HDEBUG(D_verify) | |
233 | debug_printf("callout cache: domain gave initial rejection, or " | |
234 | "does not accept HELO or MAIL FROM:<>\n"); | |
235 | setflag(addr, af_verify_nsfail); | |
236 | addr->user_message = US"(result of an earlier callout reused)."; | |
237 | yield = FAIL; | |
238 | goto END_CALLOUT; | |
239 | } | |
240 | ||
241 | /* If a previous check on a "random" local part was accepted, we assume | |
242 | that the server does not do any checking on local parts. There is therefore | |
243 | no point in doing the callout, because it will always be successful. If a | |
244 | random check previously failed, arrange not to do it again, but preserve | |
245 | the data in the new record. If a random check is required but hasn't been | |
246 | done, skip the remaining cache processing. */ | |
247 | ||
248 | if (callout_random) switch(cache_record->random_result) | |
249 | { | |
250 | case ccache_accept: | |
251 | HDEBUG(D_verify) | |
252 | debug_printf("callout cache: domain accepts random addresses\n"); | |
253 | goto END_CALLOUT; /* Default yield is OK */ | |
254 | ||
255 | case ccache_reject: | |
256 | HDEBUG(D_verify) | |
257 | debug_printf("callout cache: domain rejects random addresses\n"); | |
258 | callout_random = FALSE; | |
259 | new_domain_record.random_result = ccache_reject; | |
260 | new_domain_record.random_stamp = cache_record->random_stamp; | |
261 | break; | |
262 | ||
263 | default: | |
264 | HDEBUG(D_verify) | |
265 | debug_printf("callout cache: need to check random address handling " | |
266 | "(not cached or cache expired)\n"); | |
267 | goto END_CACHE; | |
268 | } | |
269 | ||
270 | /* If a postmaster check is requested, but there was a previous failure, | |
271 | there is again no point in carrying on. If a postmaster check is required, | |
272 | but has not been done before, we are going to have to do a callout, so skip | |
273 | remaining cache processing. */ | |
274 | ||
275 | if (pm_mailfrom != NULL) | |
276 | { | |
277 | if (cache_record->postmaster_result == ccache_reject) | |
278 | { | |
279 | setflag(addr, af_verify_pmfail); | |
280 | HDEBUG(D_verify) | |
281 | debug_printf("callout cache: domain does not accept " | |
282 | "RCPT TO:<postmaster@domain>\n"); | |
283 | yield = FAIL; | |
284 | setflag(addr, af_verify_pmfail); | |
285 | addr->user_message = US"(result of earlier verification reused)."; | |
286 | goto END_CALLOUT; | |
287 | } | |
288 | if (cache_record->postmaster_result == ccache_unknown) | |
289 | { | |
290 | HDEBUG(D_verify) | |
291 | debug_printf("callout cache: need to check RCPT " | |
292 | "TO:<postmaster@domain> (not cached or cache expired)\n"); | |
293 | goto END_CACHE; | |
294 | } | |
295 | ||
296 | /* If cache says OK, set pm_mailfrom NULL to prevent a redundant | |
297 | postmaster check if the address itself has to be checked. Also ensure | |
298 | that the value in the cache record is preserved (with its old timestamp). | |
299 | */ | |
300 | ||
301 | HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT " | |
302 | "TO:<postmaster@domain>\n"); | |
303 | pm_mailfrom = NULL; | |
304 | new_domain_record.postmaster_result = ccache_accept; | |
305 | new_domain_record.postmaster_stamp = cache_record->postmaster_stamp; | |
306 | } | |
307 | } | |
308 | ||
309 | /* We can't give a result based on information about the domain. See if there | |
310 | is an unexpired cache record for this specific address (combined with the | |
311 | sender address if we are doing a recipient callout with a non-empty sender). | |
312 | */ | |
313 | ||
314 | cache_address_record = (dbdata_callout_cache_address *) | |
315 | get_callout_cache_record(dbm_file, | |
316 | address_key, US"address", | |
317 | callout_cache_positive_expire, | |
318 | callout_cache_negative_expire); | |
319 | ||
320 | if (cache_address_record != NULL) | |
321 | { | |
322 | if (cache_address_record->result == ccache_accept) | |
323 | { | |
324 | HDEBUG(D_verify) | |
325 | debug_printf("callout cache: address record is positive\n"); | |
326 | } | |
327 | else | |
328 | { | |
329 | HDEBUG(D_verify) | |
330 | debug_printf("callout cache: address record is negative\n"); | |
331 | addr->user_message = US"Previous (cached) callout verification failure"; | |
332 | yield = FAIL; | |
333 | } | |
334 | goto END_CALLOUT; | |
335 | } | |
336 | ||
337 | /* Close the cache database while we actually do the callout for real. */ | |
338 | ||
339 | END_CACHE: | |
340 | dbfn_close(dbm_file); | |
341 | dbm_file = NULL; | |
342 | } | |
343 | ||
344 | /* The information wasn't available in the cache, so we have to do a real | |
345 | callout and save the result in the cache for next time, unless no_cache is set, | |
346 | or unless we have a previously cached negative random result. If we are to test | |
347 | with a random local part, ensure that such a local part is available. If not, | |
348 | log the fact, but carry on without randomming. */ | |
349 | ||
350 | if (callout_random && callout_random_local_part != NULL) | |
351 | { | |
352 | random_local_part = expand_string(callout_random_local_part); | |
353 | if (random_local_part == NULL) | |
354 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " | |
355 | "callout_random_local_part: %s", expand_string_message); | |
356 | } | |
357 | ||
358 | /* Default the overall callout timeout if not set, and record the time we are | |
359 | starting so that we can enforce it. */ | |
360 | ||
361 | if (callout_overall < 0) callout_overall = 4 * callout; | |
362 | callout_start_time = time(NULL); | |
363 | ||
364 | /* Now make connections to the hosts and do real callouts. The list of hosts | |
365 | is passed in as an argument. */ | |
366 | ||
367 | for (host = host_list; host != NULL && !done; host = host->next) | |
368 | { | |
369 | smtp_inblock inblock; | |
370 | smtp_outblock outblock; | |
371 | int host_af; | |
372 | int port = 25; | |
373 | uschar *helo = US"HELO"; | |
374 | uschar *interface = NULL; /* Outgoing interface to use; NULL => any */ | |
375 | uschar inbuffer[4096]; | |
376 | uschar outbuffer[1024]; | |
377 | uschar responsebuffer[4096]; | |
378 | ||
379 | clearflag(addr, af_verify_pmfail); /* postmaster callout flag */ | |
380 | clearflag(addr, af_verify_nsfail); /* null sender callout flag */ | |
381 | ||
382 | /* Skip this host if we don't have an IP address for it. */ | |
383 | ||
384 | if (host->address == NULL) | |
385 | { | |
386 | DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n", | |
387 | host->name); | |
388 | continue; | |
389 | } | |
390 | ||
391 | /* Check the overall callout timeout */ | |
392 | ||
393 | if (time(NULL) - callout_start_time >= callout_overall) | |
394 | { | |
395 | HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n"); | |
396 | break; | |
397 | } | |
398 | ||
399 | /* Set IPv4 or IPv6 */ | |
400 | ||
401 | host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6; | |
402 | ||
403 | /* Expand and interpret the interface and port strings. This has to | |
404 | be delayed till now, because they may expand differently for different | |
405 | hosts. If there's a failure, log it, but carry on with the defaults. */ | |
406 | ||
407 | deliver_host = host->name; | |
408 | deliver_host_address = host->address; | |
409 | if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface, | |
410 | US"callout") || | |
411 | !smtp_get_port(tf->port, addr, &port, US"callout")) | |
412 | log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address, | |
413 | addr->message); | |
414 | deliver_host = deliver_host_address = NULL; | |
415 | ||
416 | /* Set HELO string according to the protocol */ | |
417 | ||
418 | if (Ustrcmp(tf->protocol, "lmtp") == 0) helo = US"LHLO"; | |
419 | ||
420 | HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port); | |
421 | ||
422 | /* Set up the buffer for reading SMTP response packets. */ | |
423 | ||
424 | inblock.buffer = inbuffer; | |
425 | inblock.buffersize = sizeof(inbuffer); | |
426 | inblock.ptr = inbuffer; | |
427 | inblock.ptrend = inbuffer; | |
428 | ||
429 | /* Set up the buffer for holding SMTP commands while pipelining */ | |
430 | ||
431 | outblock.buffer = outbuffer; | |
432 | outblock.buffersize = sizeof(outbuffer); | |
433 | outblock.ptr = outbuffer; | |
434 | outblock.cmd_count = 0; | |
435 | outblock.authenticating = FALSE; | |
436 | ||
437 | /* Connect to the host; on failure, just loop for the next one, but we | |
438 | set the error for the last one. */ | |
439 | ||
440 | inblock.sock = outblock.sock = | |
441 | smtp_connect(host, host_af, port, interface, callout, TRUE); | |
442 | if (inblock.sock < 0) | |
443 | { | |
444 | addr->message = string_sprintf("could not connect to %s [%s]: %s", | |
445 | host->name, host->address, strerror(errno)); | |
446 | continue; | |
447 | } | |
448 | ||
449 | /* Wait for initial response, and then run the initial SMTP commands. The | |
450 | smtp_write_command() function leaves its command in big_buffer. This is | |
451 | used in error responses. Initialize it in case the connection is | |
452 | rejected. */ | |
453 | ||
454 | Ustrcpy(big_buffer, "initial connection"); | |
455 | ||
456 | done = | |
457 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
458 | '2', callout) && | |
459 | ||
460 | smtp_write_command(&outblock, FALSE, "%s %s\r\n", helo, | |
461 | smtp_active_hostname) >= 0 && | |
462 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
463 | '2', callout) && | |
464 | ||
465 | smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n", | |
466 | from_address) >= 0 && | |
467 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
468 | '2', callout); | |
469 | ||
470 | /* If the host gave an initial error, or does not accept HELO or MAIL | |
471 | FROM:<>, arrange to cache this information, but don't record anything for an | |
472 | I/O error or a defer. Do not cache rejections when a non-empty sender has | |
473 | been used, because that blocks the whole domain for all senders. */ | |
474 | ||
475 | if (!done) | |
476 | { | |
477 | if (errno == 0 && responsebuffer[0] == '5') | |
478 | { | |
479 | setflag(addr, af_verify_nsfail); | |
480 | if (from_address[0] == 0) new_domain_record.result = ccache_reject; | |
481 | } | |
482 | } | |
483 | ||
484 | /* Otherwise, proceed to check a "random" address (if required), then the | |
485 | given address, and the postmaster address (if required). Between each check, | |
486 | issue RSET, because some servers accept only one recipient after MAIL | |
487 | FROM:<>. */ | |
488 | ||
489 | else | |
490 | { | |
491 | new_domain_record.result = ccache_accept; | |
492 | ||
493 | /* Do the random local part check first */ | |
494 | ||
495 | if (random_local_part != NULL) | |
496 | { | |
497 | uschar randombuffer[1024]; | |
498 | BOOL random_ok = | |
499 | smtp_write_command(&outblock, FALSE, | |
500 | "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part, | |
501 | addr->domain) >= 0 && | |
502 | smtp_read_response(&inblock, randombuffer, | |
503 | sizeof(randombuffer), '2', callout); | |
504 | ||
505 | /* Remember when we last did a random test */ | |
506 | ||
507 | new_domain_record.random_stamp = time(NULL); | |
508 | ||
509 | /* If accepted, we aren't going to do any further tests below. */ | |
510 | ||
511 | if (random_ok) | |
512 | { | |
513 | new_domain_record.random_result = ccache_accept; | |
514 | } | |
515 | ||
516 | /* Otherwise, cache a real negative response, and get back to the right | |
517 | state to send RCPT. Unless there's some problem such as a dropped | |
518 | connection, we expect to succeed, because the commands succeeded above. */ | |
519 | ||
520 | else if (errno == 0) | |
521 | { | |
522 | if (randombuffer[0] == '5') | |
523 | new_domain_record.random_result = ccache_reject; | |
524 | ||
525 | done = | |
526 | smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 && | |
527 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
528 | '2', callout) && | |
529 | ||
530 | smtp_write_command(&outblock, FALSE, "MAIL FROM:<>\r\n") >= 0 && | |
531 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
532 | '2', callout); | |
533 | } | |
534 | else done = FALSE; /* Some timeout/connection problem */ | |
535 | } /* Random check */ | |
536 | ||
537 | /* If the host is accepting all local parts, as determined by the "random" | |
538 | check, we don't need to waste time doing any further checking. */ | |
539 | ||
540 | if (new_domain_record.random_result != ccache_accept && done) | |
541 | { | |
542 | done = | |
543 | smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n", | |
544 | addr->address) >= 0 && | |
545 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
546 | '2', callout); | |
547 | ||
548 | if (done) | |
549 | new_address_record.result = ccache_accept; | |
550 | else if (errno == 0 && responsebuffer[0] == '5') | |
551 | new_address_record.result = ccache_reject; | |
552 | ||
553 | /* Do postmaster check if requested */ | |
554 | ||
555 | if (done && pm_mailfrom != NULL) | |
556 | { | |
557 | done = | |
558 | smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 && | |
559 | smtp_read_response(&inblock, responsebuffer, | |
560 | sizeof(responsebuffer), '2', callout) && | |
561 | ||
562 | smtp_write_command(&outblock, FALSE, | |
563 | "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 && | |
564 | smtp_read_response(&inblock, responsebuffer, | |
565 | sizeof(responsebuffer), '2', callout) && | |
566 | ||
567 | smtp_write_command(&outblock, FALSE, | |
568 | "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 && | |
569 | smtp_read_response(&inblock, responsebuffer, | |
570 | sizeof(responsebuffer), '2', callout); | |
571 | ||
572 | new_domain_record.postmaster_stamp = time(NULL); | |
573 | ||
574 | if (done) | |
575 | new_domain_record.postmaster_result = ccache_accept; | |
576 | else if (errno == 0 && responsebuffer[0] == '5') | |
577 | { | |
578 | setflag(addr, af_verify_pmfail); | |
579 | new_domain_record.postmaster_result = ccache_reject; | |
580 | } | |
581 | } | |
582 | } /* Random not accepted */ | |
583 | } /* MAIL FROM:<> accepted */ | |
584 | ||
585 | /* For any failure of the main check, other than a negative response, we just | |
586 | close the connection and carry on. We can identify a negative response by the | |
587 | fact that errno is zero. For I/O errors it will be non-zero | |
588 | ||
589 | Set up different error texts for logging and for sending back to the caller | |
590 | as an SMTP response. Log in all cases, using a one-line format. For sender | |
591 | callouts, give a full response to the caller, but for recipient callouts, | |
592 | don't give the IP address because this may be an internal host whose identity | |
593 | is not to be widely broadcast. */ | |
594 | ||
595 | if (!done) | |
596 | { | |
597 | if (errno == ETIMEDOUT) | |
598 | { | |
599 | HDEBUG(D_verify) debug_printf("SMTP timeout\n"); | |
600 | } | |
601 | else if (errno == 0) | |
602 | { | |
603 | if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped"); | |
604 | ||
605 | addr->message = | |
606 | string_sprintf("response to \"%s\" from %s [%s] was: %s", | |
607 | big_buffer, host->name, host->address, | |
608 | string_printing(responsebuffer)); | |
609 | ||
610 | addr->user_message = is_recipient? | |
611 | string_sprintf("Callout verification failed:\n%s", responsebuffer) | |
612 | : | |
613 | string_sprintf("Called: %s\nSent: %s\nResponse: %s", | |
614 | host->address, big_buffer, responsebuffer); | |
615 | ||
616 | /* Hard rejection ends the process */ | |
617 | ||
618 | if (responsebuffer[0] == '5') /* Address rejected */ | |
619 | { | |
620 | yield = FAIL; | |
621 | done = TRUE; | |
622 | } | |
623 | } | |
624 | } | |
625 | ||
626 | /* End the SMTP conversation and close the connection. */ | |
627 | ||
628 | (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n"); | |
629 | close(inblock.sock); | |
630 | } /* Loop through all hosts, while !done */ | |
631 | ||
632 | /* If we get here with done == TRUE, a successful callout happened, and yield | |
633 | will be set OK or FAIL according to the response to the RCPT command. | |
634 | Otherwise, we looped through the hosts but couldn't complete the business. | |
635 | However, there may be domain-specific information to cache in both cases. | |
636 | ||
637 | The value of the result field in the new_domain record is ccache_unknown if | |
638 | there was an error before or with MAIL FROM:<>, and errno was not zero, | |
639 | implying some kind of I/O error. We don't want to write the cache in that case. | |
640 | Otherwise the value is ccache_accept or ccache_reject. */ | |
641 | ||
642 | if (!callout_no_cache && new_domain_record.result != ccache_unknown) | |
643 | { | |
644 | if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)) | |
645 | == NULL) | |
646 | { | |
647 | HDEBUG(D_verify) debug_printf("callout cache: not available\n"); | |
648 | } | |
649 | else | |
650 | { | |
651 | (void)dbfn_write(dbm_file, addr->domain, &new_domain_record, | |
652 | (int)sizeof(dbdata_callout_cache)); | |
653 | HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n" | |
654 | " result=%d postmaster=%d random=%d\n", | |
655 | new_domain_record.result, | |
656 | new_domain_record.postmaster_result, | |
657 | new_domain_record.random_result); | |
658 | } | |
659 | } | |
660 | ||
661 | /* If a definite result was obtained for the callout, cache it unless caching | |
662 | is disabled. */ | |
663 | ||
664 | if (done) | |
665 | { | |
666 | if (!callout_no_cache && new_address_record.result != ccache_unknown) | |
667 | { | |
668 | if (dbm_file == NULL) | |
669 | dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE); | |
670 | if (dbm_file == NULL) | |
671 | { | |
672 | HDEBUG(D_verify) debug_printf("no callout cache available\n"); | |
673 | } | |
674 | else | |
675 | { | |
676 | (void)dbfn_write(dbm_file, address_key, &new_address_record, | |
677 | (int)sizeof(dbdata_callout_cache_address)); | |
678 | HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n", | |
679 | (new_address_record.result == ccache_accept)? "positive" : "negative"); | |
680 | } | |
681 | } | |
682 | } /* done */ | |
683 | ||
684 | /* Failure to connect to any host, or any response other than 2xx or 5xx is a | |
685 | temporary error. If there was only one host, and a response was received, leave | |
686 | it alone if supplying details. Otherwise, give a generic response. */ | |
687 | ||
688 | else /* !done */ | |
689 | { | |
690 | uschar *dullmsg = string_sprintf("Could not complete %s verify callout", | |
691 | is_recipient? "recipient" : "sender"); | |
692 | yield = DEFER; | |
693 | ||
694 | if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg; | |
695 | ||
696 | addr->user_message = (!smtp_return_error_details)? dullmsg : | |
697 | string_sprintf("%s for <%s>.\n" | |
698 | "The mail server(s) for the domain may be temporarily unreachable, or\n" | |
699 | "they may be permanently unreachable from this server. In the latter case,\n%s", | |
700 | dullmsg, addr->address, | |
701 | is_recipient? | |
702 | "the address will never be accepted." | |
703 | : | |
704 | "you need to change the address or create an MX record for its domain\n" | |
705 | "if it is supposed to be generally accessible from the Internet.\n" | |
706 | "Talk to your mail administrator for details."); | |
707 | ||
708 | /* Force a specific error code */ | |
709 | ||
710 | addr->basic_errno = ERRNO_CALLOUTDEFER; | |
711 | } | |
712 | ||
713 | /* Come here from within the cache-reading code on fast-track exit. */ | |
714 | ||
715 | END_CALLOUT: | |
716 | if (dbm_file != NULL) dbfn_close(dbm_file); | |
717 | return yield; | |
718 | } | |
719 | ||
720 | ||
721 | ||
722 | /************************************************* | |
723 | * Copy error to toplevel address * | |
724 | *************************************************/ | |
725 | ||
726 | /* This function is used when a verify fails or defers, to ensure that the | |
727 | failure or defer information is in the original toplevel address. This applies | |
728 | when an address is redirected to a single new address, and the failure or | |
729 | deferral happens to the child address. | |
730 | ||
731 | Arguments: | |
732 | vaddr the verify address item | |
733 | addr the final address item | |
734 | yield FAIL or DEFER | |
735 | ||
736 | Returns: the value of YIELD | |
737 | */ | |
738 | ||
739 | static int | |
740 | copy_error(address_item *vaddr, address_item *addr, int yield) | |
741 | { | |
742 | if (addr != vaddr) | |
743 | { | |
744 | vaddr->message = addr->message; | |
745 | vaddr->user_message = addr->user_message; | |
746 | vaddr->basic_errno = addr->basic_errno; | |
747 | vaddr->more_errno = addr->more_errno; | |
748 | } | |
749 | return yield; | |
750 | } | |
751 | ||
752 | ||
753 | ||
754 | ||
755 | /************************************************* | |
756 | * Verify an email address * | |
757 | *************************************************/ | |
758 | ||
759 | /* This function is used both for verification (-bv and at other times) and | |
760 | address testing (-bt), which is indicated by address_test_mode being set. | |
761 | ||
762 | Arguments: | |
763 | vaddr contains the address to verify; the next field in this block | |
764 | must be NULL | |
765 | f if not NULL, write the result to this file | |
766 | options various option bits: | |
767 | vopt_fake_sender => this sender verify is not for the real | |
768 | sender (it was verify=sender=xxxx or an address from a | |
769 | header line) - rewriting must not change sender_address | |
770 | vopt_is_recipient => this is a recipient address, otherwise | |
771 | it's a sender address - this affects qualification and | |
772 | rewriting and messages from callouts | |
773 | vopt_qualify => qualify an unqualified address; else error | |
774 | vopt_expn => called from SMTP EXPN command | |
775 | ||
776 | These ones are used by do_callout() -- the options variable | |
777 | is passed to it. | |
778 | ||
779 | vopt_callout_no_cache => don't use callout cache | |
780 | vopt_callout_random => do the "random" thing | |
781 | vopt_callout_recipsender => use real sender for recipient | |
782 | vopt_callout_recippmaster => use postmaster for recipient | |
783 | ||
784 | callout if > 0, specifies that callout is required, and gives timeout | |
785 | for individual connections and commands | |
786 | callout_overall if > 0, gives overall timeout for the callout function; | |
787 | if < 0, a default is used (see do_callout()) | |
788 | se_mailfrom when callout is requested to verify a sender, use this | |
789 | in MAIL FROM; NULL => "" | |
790 | pm_mailfrom when callout is requested, if non-NULL, do the postmaster | |
791 | thing and use this as the sender address (may be "") | |
792 | ||
793 | routed if not NULL, set TRUE if routing succeeded, so we can | |
794 | distinguish between routing failed and callout failed | |
795 | ||
796 | Returns: OK address verified | |
797 | FAIL address failed to verify | |
798 | DEFER can't tell at present | |
799 | */ | |
800 | ||
801 | int | |
802 | verify_address(address_item *vaddr, FILE *f, int options, int callout, | |
803 | int callout_overall, uschar *se_mailfrom, uschar *pm_mailfrom, BOOL *routed) | |
804 | { | |
805 | BOOL allok = TRUE; | |
806 | BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0); | |
807 | BOOL is_recipient = (options & vopt_is_recipient) != 0; | |
808 | BOOL expn = (options & vopt_expn) != 0; | |
809 | ||
810 | int i; | |
811 | int yield = OK; | |
812 | int verify_type = expn? v_expn : | |
813 | address_test_mode? v_none : | |
814 | is_recipient? v_recipient : v_sender; | |
815 | address_item *addr_list; | |
816 | address_item *addr_new = NULL; | |
817 | address_item *addr_remote = NULL; | |
818 | address_item *addr_local = NULL; | |
819 | address_item *addr_succeed = NULL; | |
820 | uschar *ko_prefix, *cr; | |
821 | uschar *address = vaddr->address; | |
822 | uschar *save_sender; | |
823 | uschar null_sender[] = { 0 }; /* Ensure writeable memory */ | |
824 | ||
825 | /* Set up a prefix and suffix for error message which allow us to use the same | |
826 | output statements both in EXPN mode (where an SMTP response is needed) and when | |
827 | debugging with an output file. */ | |
828 | ||
829 | if (expn) | |
830 | { | |
831 | ko_prefix = US"553 "; | |
832 | cr = US"\r"; | |
833 | } | |
834 | else ko_prefix = cr = US""; | |
835 | ||
836 | /* Add qualify domain if permitted; otherwise an unqualified address fails. */ | |
837 | ||
838 | if (parse_find_at(address) == NULL) | |
839 | { | |
840 | if ((options & vopt_qualify) == 0) | |
841 | { | |
842 | if (f != NULL) | |
843 | fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address, | |
844 | cr); | |
845 | return FAIL; | |
846 | } | |
847 | address = rewrite_address_qualify(address, is_recipient); | |
848 | } | |
849 | ||
850 | DEBUG(D_verify) | |
851 | { | |
852 | debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); | |
853 | debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address); | |
854 | } | |
855 | ||
856 | /* Rewrite and report on it. Clear the domain and local part caches - these | |
857 | may have been set by domains and local part tests during an ACL. */ | |
858 | ||
859 | if (global_rewrite_rules != NULL) | |
860 | { | |
861 | uschar *old = address; | |
862 | address = rewrite_address(address, is_recipient, FALSE, | |
863 | global_rewrite_rules, rewrite_existflags); | |
864 | if (address != old) | |
865 | { | |
866 | for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0; | |
867 | for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0; | |
868 | if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address); | |
869 | } | |
870 | } | |
871 | ||
872 | /* If this is the real sender address, we must update sender_address at | |
873 | this point, because it may be referred to in the routers. */ | |
874 | ||
875 | if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0) | |
876 | sender_address = address; | |
877 | ||
878 | /* If the address was rewritten to <> no verification can be done, and we have | |
879 | to return OK. This rewriting is permitted only for sender addresses; for other | |
880 | addresses, such rewriting fails. */ | |
881 | ||
882 | if (address[0] == 0) return OK; | |
883 | ||
884 | /* Save a copy of the sender address for re-instating if we change it to <> | |
885 | while verifying a sender address (a nice bit of self-reference there). */ | |
886 | ||
887 | save_sender = sender_address; | |
888 | ||
889 | /* Update the address structure with the possibly qualified and rewritten | |
890 | address. Set it up as the starting address on the chain of new addresses. */ | |
891 | ||
892 | vaddr->address = address; | |
893 | addr_new = vaddr; | |
894 | ||
895 | /* We need a loop, because an address can generate new addresses. We must also | |
896 | cope with generated pipes and files at the top level. (See also the code and | |
897 | comment in deliver.c.) However, it is usually the case that the router for | |
898 | user's .forward files has its verify flag turned off. | |
899 | ||
900 | If an address generates more than one child, the loop is used only when | |
901 | full_info is set, and this can only be set locally. Remote enquiries just get | |
902 | information about the top level address, not anything that it generated. */ | |
903 | ||
904 | while (addr_new != NULL) | |
905 | { | |
906 | int rc; | |
907 | address_item *addr = addr_new; | |
908 | ||
909 | addr_new = addr->next; | |
910 | addr->next = NULL; | |
911 | ||
912 | DEBUG(D_verify) | |
913 | { | |
914 | debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); | |
915 | debug_printf("Considering %s\n", addr->address); | |
916 | } | |
917 | ||
918 | /* Handle generated pipe, file or reply addresses. We don't get these | |
919 | when handling EXPN, as it does only one level of expansion. */ | |
920 | ||
921 | if (testflag(addr, af_pfr)) | |
922 | { | |
923 | allok = FALSE; | |
924 | if (f != NULL) | |
925 | { | |
926 | BOOL allow; | |
927 | ||
928 | if (addr->address[0] == '>') | |
929 | { | |
930 | allow = testflag(addr, af_allow_reply); | |
931 | fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1); | |
932 | } | |
933 | else | |
934 | { | |
935 | allow = (addr->address[0] == '|')? | |
936 | testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file); | |
937 | fprintf(f, "%s -> %s", addr->parent->address, addr->address); | |
938 | } | |
939 | ||
940 | if (addr->basic_errno == ERRNO_BADTRANSPORT) | |
941 | fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n" | |
942 | "%s\n", addr->message); | |
943 | else if (allow) | |
944 | fprintf(f, "\n transport = %s\n", addr->transport->name); | |
945 | else | |
946 | fprintf(f, " *** forbidden ***\n"); | |
947 | } | |
948 | continue; | |
949 | } | |
950 | ||
951 | /* Just in case some router parameter refers to it. */ | |
952 | ||
953 | return_path = (addr->p.errors_address != NULL)? | |
954 | addr->p.errors_address : sender_address; | |
955 | ||
956 | /* Split the address into domain and local part, handling the %-hack if | |
957 | necessary, and then route it. While routing a sender address, set | |
958 | $sender_address to <> because that is what it will be if we were trying to | |
959 | send a bounce to the sender. */ | |
960 | ||
961 | if (routed != NULL) *routed = FALSE; | |
962 | if ((rc = deliver_split_address(addr)) == OK) | |
963 | { | |
964 | if (!is_recipient) sender_address = null_sender; | |
965 | rc = route_address(addr, &addr_local, &addr_remote, &addr_new, | |
966 | &addr_succeed, verify_type); | |
967 | sender_address = save_sender; /* Put back the real sender */ | |
968 | } | |
969 | ||
970 | /* If routing an address succeeded, set the flag that remembers, for use when | |
971 | an ACL cached a sender verify (in case a callout fails). Then if routing set | |
972 | up a list of hosts or the transport has a host list, and the callout option | |
973 | is set, and we aren't in a host checking run, do the callout verification, | |
974 | and set another flag that notes that a callout happened. */ | |
975 | ||
976 | if (rc == OK) | |
977 | { | |
978 | if (routed != NULL) *routed = TRUE; | |
979 | if (callout > 0) | |
980 | { | |
981 | host_item *host_list = addr->host_list; | |
982 | ||
983 | /* Default, if no remote transport, to NULL for the interface (=> any), | |
984 | "smtp" for the port, and "smtp" for the protocol. */ | |
985 | ||
986 | transport_feedback tf = { NULL, US"smtp", US"smtp", NULL, FALSE, FALSE }; | |
987 | ||
988 | /* If verification yielded a remote transport, we want to use that | |
989 | transport's options, so as to mimic what would happen if we were really | |
990 | sending a message to this address. */ | |
991 | ||
992 | if (addr->transport != NULL && !addr->transport->info->local) | |
993 | { | |
994 | (void)(addr->transport->setup)(addr->transport, addr, &tf, NULL); | |
995 | ||
996 | /* If the transport has hosts and the router does not, or if the | |
997 | transport is configured to override the router's hosts, we must build a | |
998 | host list of the transport's hosts, and find the IP addresses */ | |
999 | ||
1000 | if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override)) | |
1001 | { | |
1002 | uschar *s; | |
1003 | ||
1004 | host_list = NULL; /* Ignore the router's hosts */ | |
1005 | ||
1006 | deliver_domain = addr->domain; | |
1007 | deliver_localpart = addr->local_part; | |
1008 | s = expand_string(tf.hosts); | |
1009 | deliver_domain = deliver_localpart = NULL; | |
1010 | ||
1011 | if (s == NULL) | |
1012 | { | |
1013 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts " | |
1014 | "\"%s\" in %s transport for callout: %s", tf.hosts, | |
1015 | addr->transport->name, expand_string_message); | |
1016 | } | |
1017 | else | |
1018 | { | |
1019 | uschar *canonical_name; | |
1020 | host_item *host; | |
1021 | host_build_hostlist(&host_list, s, tf.hosts_randomize); | |
1022 | ||
1023 | /* Just ignore failures to find a host address. If we don't manage | |
1024 | to find any addresses, the callout will defer. */ | |
1025 | ||
1026 | for (host = host_list; host != NULL; host = host->next) | |
1027 | { | |
1028 | if (tf.gethostbyname || string_is_ip_address(host->name, NULL)) | |
1029 | (void)host_find_byname(host, NULL, &canonical_name, TRUE); | |
1030 | else | |
1031 | { | |
1032 | int flags = HOST_FIND_BY_A; | |
1033 | if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE; | |
1034 | if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS; | |
1035 | (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL, | |
1036 | &canonical_name, NULL); | |
1037 | } | |
1038 | } | |
1039 | } | |
1040 | } | |
1041 | } | |
1042 | ||
1043 | /* Can only do a callout if we have at least one host! */ | |
1044 | ||
1045 | if (host_list != NULL) | |
1046 | { | |
1047 | HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n"); | |
1048 | if (host_checking && !host_checking_callout) | |
1049 | { | |
1050 | HDEBUG(D_verify) | |
1051 | debug_printf("... callout omitted by default when host testing\n" | |
1052 | "(Use -bhc if you want the callouts to happen.)\n"); | |
1053 | } | |
1054 | else | |
1055 | { | |
1056 | rc = do_callout(addr, host_list, &tf, callout, callout_overall, | |
1057 | options, se_mailfrom, pm_mailfrom); | |
1058 | } | |
1059 | } | |
1060 | else | |
1061 | { | |
1062 | HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor " | |
1063 | "transport provided a host list\n"); | |
1064 | } | |
1065 | } | |
1066 | } | |
1067 | ||
1068 | /* A router may return REROUTED if it has set up a child address as a result | |
1069 | of a change of domain name (typically from widening). In this case we always | |
1070 | want to continue to verify the new child. */ | |
1071 | ||
1072 | if (rc == REROUTED) continue; | |
1073 | ||
1074 | /* Handle hard failures */ | |
1075 | ||
1076 | if (rc == FAIL) | |
1077 | { | |
1078 | allok = FALSE; | |
1079 | if (f != NULL) | |
1080 | { | |
1081 | fprintf(f, "%s%s %s", ko_prefix, address, | |
1082 | address_test_mode? "is undeliverable" : "failed to verify"); | |
1083 | if (!expn && admin_user) | |
1084 | { | |
1085 | if (addr->basic_errno > 0) | |
1086 | fprintf(f, ": %s", strerror(addr->basic_errno)); | |
1087 | if (addr->message != NULL) | |
1088 | fprintf(f, ":\n %s", addr->message); | |
1089 | } | |
1090 | fprintf(f, "%s\n", cr); | |
1091 | } | |
1092 | ||
1093 | if (!full_info) return copy_error(vaddr, addr, FAIL); | |
1094 | else yield = FAIL; | |
1095 | } | |
1096 | ||
1097 | /* Soft failure */ | |
1098 | ||
1099 | else if (rc == DEFER) | |
1100 | { | |
1101 | allok = FALSE; | |
1102 | if (f != NULL) | |
1103 | { | |
1104 | fprintf(f, "%s%s cannot be resolved at this time", ko_prefix, address); | |
1105 | if (!expn && admin_user) | |
1106 | { | |
1107 | if (addr->basic_errno > 0) | |
1108 | fprintf(f, ":\n %s", strerror(addr->basic_errno)); | |
1109 | if (addr->message != NULL) | |
1110 | fprintf(f, ":\n %s", addr->message); | |
1111 | else if (addr->basic_errno <= 0) | |
1112 | fprintf(f, ":\n unknown error"); | |
1113 | } | |
1114 | ||
1115 | fprintf(f, "%s\n", cr); | |
1116 | } | |
1117 | if (!full_info) return copy_error(vaddr, addr, DEFER); | |
1118 | else if (yield == OK) yield = DEFER; | |
1119 | } | |
1120 | ||
1121 | /* If we are handling EXPN, we do not want to continue to route beyond | |
1122 | the top level. */ | |
1123 | ||
1124 | else if (expn) | |
1125 | { | |
1126 | uschar *ok_prefix = US"250-"; | |
1127 | if (addr_new == NULL) | |
1128 | { | |
1129 | if (addr_local == NULL && addr_remote == NULL) | |
1130 | fprintf(f, "250 mail to <%s> is discarded\r\n", address); | |
1131 | else | |
1132 | fprintf(f, "250 <%s>\r\n", address); | |
1133 | } | |
1134 | else while (addr_new != NULL) | |
1135 | { | |
1136 | address_item *addr2 = addr_new; | |
1137 | addr_new = addr2->next; | |
1138 | if (addr_new == NULL) ok_prefix = US"250 "; | |
1139 | fprintf(f, "%s<%s>\r\n", ok_prefix, addr2->address); | |
1140 | } | |
1141 | return OK; | |
1142 | } | |
1143 | ||
1144 | /* Successful routing other than EXPN. */ | |
1145 | ||
1146 | else | |
1147 | { | |
1148 | /* Handle successful routing when short info wanted. Otherwise continue for | |
1149 | other (generated) addresses. Short info is the operational case. Full info | |
1150 | can be requested only when debug_selector != 0 and a file is supplied. | |
1151 | ||
1152 | There is a conflict between the use of aliasing as an alternate email | |
1153 | address, and as a sort of mailing list. If an alias turns the incoming | |
1154 | address into just one address (e.g. J.Caesar->jc44) you may well want to | |
1155 | carry on verifying the generated address to ensure it is valid when | |
1156 | checking incoming mail. If aliasing generates multiple addresses, you | |
1157 | probably don't want to do this. Exim therefore treats the generation of | |
1158 | just a single new address as a special case, and continues on to verify the | |
1159 | generated address. */ | |
1160 | ||
1161 | if (!full_info && /* Stop if short info wanted AND */ | |
1162 | (addr_new == NULL || /* No new address OR */ | |
1163 | addr_new->next != NULL || /* More than one new address OR */ | |
1164 | testflag(addr_new, af_pfr))) /* New address is pfr */ | |
1165 | { | |
1166 | if (f != NULL) fprintf(f, "%s %s\n", address, | |
1167 | address_test_mode? "is deliverable" : "verified"); | |
1168 | ||
1169 | /* If we have carried on to verify a child address, we want the value | |
1170 | of $address_data to be that of the child */ | |
1171 | ||
1172 | vaddr->p.address_data = addr->p.address_data; | |
1173 | return OK; | |
1174 | } | |
1175 | } | |
1176 | } /* Loop for generated addresses */ | |
1177 | ||
1178 | /* Display the full results of the successful routing, including any generated | |
1179 | addresses. Control gets here only when full_info is set, which requires f not | |
1180 | to be NULL, and this occurs only when a top-level verify is called with the | |
1181 | debugging switch on. | |
1182 | ||
1183 | If there are no local and no remote addresses, and there were no pipes, files, | |
1184 | or autoreplies, and there were no errors or deferments, the message is to be | |
1185 | discarded, usually because of the use of :blackhole: in an alias file. */ | |
1186 | ||
1187 | if (allok && addr_local == NULL && addr_remote == NULL) | |
1188 | fprintf(f, "mail to %s is discarded\n", address); | |
1189 | ||
1190 | else for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++) | |
1191 | { | |
1192 | while (addr_list != NULL) | |
1193 | { | |
1194 | address_item *addr = addr_list; | |
1195 | address_item *p = addr->parent; | |
1196 | addr_list = addr->next; | |
1197 | ||
1198 | fprintf(f, "%s", CS addr->address); | |
1199 | while (p != NULL) | |
1200 | { | |
1201 | fprintf(f, "\n <-- %s", p->address); | |
1202 | p = p->parent; | |
1203 | } | |
1204 | fprintf(f, "\n "); | |
1205 | ||
1206 | /* Show router, and transport */ | |
1207 | ||
1208 | fprintf(f, "router = %s, ", addr->router->name); | |
1209 | fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" : | |
1210 | addr->transport->name); | |
1211 | ||
1212 | /* Show any hosts that are set up by a router unless the transport | |
1213 | is going to override them; fiddle a bit to get a nice format. */ | |
1214 | ||
1215 | if (addr->host_list != NULL && addr->transport != NULL && | |
1216 | !addr->transport->overrides_hosts) | |
1217 | { | |
1218 | host_item *h; | |
1219 | int maxlen = 0; | |
1220 | int maxaddlen = 0; | |
1221 | for (h = addr->host_list; h != NULL; h = h->next) | |
1222 | { | |
1223 | int len = Ustrlen(h->name); | |
1224 | if (len > maxlen) maxlen = len; | |
1225 | len = (h->address != NULL)? Ustrlen(h->address) : 7; | |
1226 | if (len > maxaddlen) maxaddlen = len; | |
1227 | } | |
1228 | for (h = addr->host_list; h != NULL; h = h->next) | |
1229 | { | |
1230 | int len = Ustrlen(h->name); | |
1231 | fprintf(f, " host %s ", h->name); | |
1232 | while (len++ < maxlen) fprintf(f, " "); | |
1233 | if (h->address != NULL) | |
1234 | { | |
1235 | fprintf(f, "[%s] ", h->address); | |
1236 | len = Ustrlen(h->address); | |
1237 | } | |
1238 | else if (!addr->transport->info->local) /* Omit [unknown] for local */ | |
1239 | { | |
1240 | fprintf(f, "[unknown] "); | |
1241 | len = 7; | |
1242 | } | |
1243 | else len = -3; | |
1244 | while (len++ < maxaddlen) fprintf(f," "); | |
1245 | if (h->mx >= 0) fprintf(f, "MX=%d", h->mx); | |
1246 | if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port); | |
1247 | if (h->status == hstatus_unusable) fprintf(f, " ** unusable **"); | |
1248 | fprintf(f, "\n"); | |
1249 | } | |
1250 | } | |
1251 | } | |
1252 | } | |
1253 | ||
1254 | return yield; /* Will be DEFER or FAIL if any one address has */ | |
1255 | } | |
1256 | ||
1257 | ||
1258 | ||
1259 | ||
1260 | /************************************************* | |
1261 | * Check headers for syntax errors * | |
1262 | *************************************************/ | |
1263 | ||
1264 | /* This function checks those header lines that contain addresses, and verifies | |
1265 | that all the addresses therein are syntactially correct. | |
1266 | ||
1267 | Arguments: | |
1268 | msgptr where to put an error message | |
1269 | ||
1270 | Returns: OK | |
1271 | FAIL | |
1272 | */ | |
1273 | ||
1274 | int | |
1275 | verify_check_headers(uschar **msgptr) | |
1276 | { | |
1277 | header_line *h; | |
1278 | uschar *colon, *s; | |
1279 | ||
1280 | for (h = header_list; h != NULL; h = h->next) | |
1281 | { | |
1282 | if (h->type != htype_from && | |
1283 | h->type != htype_reply_to && | |
1284 | h->type != htype_sender && | |
1285 | h->type != htype_to && | |
1286 | h->type != htype_cc && | |
1287 | h->type != htype_bcc) | |
1288 | continue; | |
1289 | ||
1290 | colon = Ustrchr(h->text, ':'); | |
1291 | s = colon + 1; | |
1292 | while (isspace(*s)) s++; | |
1293 | ||
1294 | parse_allow_group = TRUE; /* Allow group syntax */ | |
1295 | ||
1296 | /* Loop for multiple addresses in the header */ | |
1297 | ||
1298 | while (*s != 0) | |
1299 | { | |
1300 | uschar *ss = parse_find_address_end(s, FALSE); | |
1301 | uschar *recipient, *errmess; | |
1302 | int terminator = *ss; | |
1303 | int start, end, domain; | |
1304 | ||
1305 | /* Temporarily terminate the string at this point, and extract the | |
1306 | operative address within. */ | |
1307 | ||
1308 | *ss = 0; | |
1309 | recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE); | |
1310 | *ss = terminator; | |
1311 | ||
1312 | /* Permit an unqualified address only if the message is local, or if the | |
1313 | sending host is configured to be permitted to send them. */ | |
1314 | ||
1315 | if (recipient != NULL && domain == 0) | |
1316 | { | |
1317 | if (h->type == htype_from || h->type == htype_sender) | |
1318 | { | |
1319 | if (!allow_unqualified_sender) recipient = NULL; | |
1320 | } | |
1321 | else | |
1322 | { | |
1323 | if (!allow_unqualified_recipient) recipient = NULL; | |
1324 | } | |
1325 | if (recipient == NULL) errmess = US"unqualified address not permitted"; | |
1326 | } | |
1327 | ||
1328 | /* It's an error if no address could be extracted, except for the special | |
1329 | case of an empty address. */ | |
1330 | ||
1331 | if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0) | |
1332 | { | |
1333 | uschar *verb = US"is"; | |
1334 | uschar *t = ss; | |
1335 | int len; | |
1336 | ||
1337 | /* Arrange not to include any white space at the end in the | |
1338 | error message. */ | |
1339 | ||
1340 | while (t > s && isspace(t[-1])) t--; | |
1341 | ||
1342 | /* Add the address which failed to the error message, since in a | |
1343 | header with very many addresses it is sometimes hard to spot | |
1344 | which one is at fault. However, limit the amount of address to | |
1345 | quote - cases have been seen where, for example, a missing double | |
1346 | quote in a humungous To: header creates an "address" that is longer | |
1347 | than string_sprintf can handle. */ | |
1348 | ||
1349 | len = t - s; | |
1350 | if (len > 1024) | |
1351 | { | |
1352 | len = 1024; | |
1353 | verb = US"begins"; | |
1354 | } | |
1355 | ||
1356 | *msgptr = string_printing( | |
1357 | string_sprintf("%s: failing address in \"%.*s\" header %s: %.*s", | |
1358 | errmess, colon - h->text, h->text, verb, len, s)); | |
1359 | ||
1360 | return FAIL; | |
1361 | } | |
1362 | ||
1363 | /* Advance to the next address */ | |
1364 | ||
1365 | s = ss + (terminator? 1:0); | |
1366 | while (isspace(*s)) s++; | |
1367 | } /* Next address */ | |
1368 | } /* Next header */ | |
1369 | ||
1370 | return OK; | |
1371 | } | |
1372 | ||
1373 | ||
1374 | ||
1375 | ||
1376 | /************************************************* | |
1377 | * Find if verified sender * | |
1378 | *************************************************/ | |
1379 | ||
1380 | /* Usually, just a single address is verified as the sender of the message. | |
1381 | However, Exim can be made to verify other addresses as well (often related in | |
1382 | some way), and this is useful in some environments. There may therefore be a | |
1383 | chain of such addresses that have previously been tested. This function finds | |
1384 | whether a given address is on the chain. | |
1385 | ||
1386 | Arguments: the address to be verified | |
1387 | Returns: pointer to an address item, or NULL | |
1388 | */ | |
1389 | ||
1390 | address_item * | |
1391 | verify_checked_sender(uschar *sender) | |
1392 | { | |
1393 | address_item *addr; | |
1394 | for (addr = sender_verified_list; addr != NULL; addr = addr->next) | |
1395 | if (Ustrcmp(sender, addr->address) == 0) break; | |
1396 | return addr; | |
1397 | } | |
1398 | ||
1399 | ||
1400 | ||
1401 | ||
1402 | ||
1403 | /************************************************* | |
1404 | * Get valid header address * | |
1405 | *************************************************/ | |
1406 | ||
1407 | /* Scan the originator headers of the message, looking for an address that | |
1408 | verifies successfully. RFC 822 says: | |
1409 | ||
1410 | o The "Sender" field mailbox should be sent notices of | |
1411 | any problems in transport or delivery of the original | |
1412 | messages. If there is no "Sender" field, then the | |
1413 | "From" field mailbox should be used. | |
1414 | ||
1415 | o If the "Reply-To" field exists, then the reply should | |
1416 | go to the addresses indicated in that field and not to | |
1417 | the address(es) indicated in the "From" field. | |
1418 | ||
1419 | So we check a Sender field if there is one, else a Reply_to field, else a From | |
1420 | field. As some strange messages may have more than one of these fields, | |
1421 | especially if they are resent- fields, check all of them if there is more than | |
1422 | one. | |
1423 | ||
1424 | Arguments: | |
1425 | user_msgptr points to where to put a user error message | |
1426 | log_msgptr points to where to put a log error message | |
1427 | callout timeout for callout check (passed to verify_address()) | |
1428 | callout_overall overall callout timeout (ditto) | |
1429 | se_mailfrom mailfrom for verify; NULL => "" | |
1430 | pm_mailfrom sender for pm callout check (passed to verify_address()) | |
1431 | options callout options (passed to verify_address()) | |
1432 | ||
1433 | If log_msgptr is set to something without setting user_msgptr, the caller | |
1434 | normally uses log_msgptr for both things. | |
1435 | ||
1436 | Returns: result of the verification attempt: OK, FAIL, or DEFER; | |
1437 | FAIL is given if no appropriate headers are found | |
1438 | */ | |
1439 | ||
1440 | int | |
1441 | verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr, | |
1442 | int callout, int callout_overall, uschar *se_mailfrom, uschar *pm_mailfrom, | |
1443 | int options) | |
1444 | { | |
1445 | static int header_types[] = { htype_sender, htype_reply_to, htype_from }; | |
1446 | int yield = FAIL; | |
1447 | int i; | |
1448 | ||
1449 | for (i = 0; i < 3; i++) | |
1450 | { | |
1451 | header_line *h; | |
1452 | for (h = header_list; h != NULL; h = h->next) | |
1453 | { | |
1454 | int terminator, new_ok; | |
1455 | uschar *s, *ss, *endname; | |
1456 | ||
1457 | if (h->type != header_types[i]) continue; | |
1458 | s = endname = Ustrchr(h->text, ':') + 1; | |
1459 | ||
1460 | while (*s != 0) | |
1461 | { | |
1462 | address_item *vaddr; | |
1463 | ||
1464 | while (isspace(*s) || *s == ',') s++; | |
1465 | if (*s == 0) break; /* End of header */ | |
1466 | ||
1467 | ss = parse_find_address_end(s, FALSE); | |
1468 | ||
1469 | /* The terminator is a comma or end of header, but there may be white | |
1470 | space preceding it (including newline for the last address). Move back | |
1471 | past any white space so we can check against any cached envelope sender | |
1472 | address verifications. */ | |
1473 | ||
1474 | while (isspace(ss[-1])) ss--; | |
1475 | terminator = *ss; | |
1476 | *ss = 0; | |
1477 | ||
1478 | HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n", | |
1479 | (int)(endname - h->text), h->text, s); | |
1480 | ||
1481 | /* See if we have already verified this address as an envelope sender, | |
1482 | and if so, use the previous answer. */ | |
1483 | ||
1484 | vaddr = verify_checked_sender(s); | |
1485 | ||
1486 | if (vaddr != NULL && /* Previously checked */ | |
1487 | (callout <= 0 || /* No callout needed; OR */ | |
1488 | vaddr->special_action > 256)) /* Callout was done */ | |
1489 | { | |
1490 | new_ok = vaddr->special_action & 255; | |
1491 | HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n"); | |
1492 | *ss = terminator; /* Restore shortened string */ | |
1493 | } | |
1494 | ||
1495 | /* Otherwise we run the verification now. We must restore the shortened | |
1496 | string before running the verification, so the headers are correct, in | |
1497 | case there is any rewriting. */ | |
1498 | ||
1499 | else | |
1500 | { | |
1501 | int start, end, domain; | |
1502 | uschar *address = parse_extract_address(s, log_msgptr, &start, | |
1503 | &end, &domain, FALSE); | |
1504 | ||
1505 | *ss = terminator; | |
1506 | ||
1507 | /* If verification failed because of a syntax error, fail this | |
1508 | function, and ensure that the failing address gets added to the error | |
1509 | message. */ | |
1510 | ||
1511 | if (address == NULL) | |
1512 | { | |
1513 | new_ok = FAIL; | |
1514 | if (*log_msgptr != NULL) | |
1515 | { | |
1516 | while (ss > s && isspace(ss[-1])) ss--; | |
1517 | *log_msgptr = string_sprintf("syntax error in '%.*s' header when " | |
1518 | "scanning for sender: %s in \"%.*s\"", | |
1519 | endname - h->text, h->text, *log_msgptr, ss - s, s); | |
1520 | return FAIL; | |
1521 | } | |
1522 | } | |
1523 | ||
1524 | /* Else go ahead with the sender verification. But is isn't *the* | |
1525 | sender of the message, so set vopt_fake_sender to stop sender_address | |
1526 | being replaced after rewriting or qualification. */ | |
1527 | ||
1528 | else | |
1529 | { | |
1530 | vaddr = deliver_make_addr(address, FALSE); | |
1531 | new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender, | |
1532 | callout, callout_overall, se_mailfrom, pm_mailfrom, NULL); | |
1533 | } | |
1534 | } | |
1535 | ||
1536 | /* We now have the result, either newly found, or cached. If we are | |
1537 | giving out error details, set a specific user error. This means that the | |
1538 | last of these will be returned to the user if all three fail. We do not | |
1539 | set a log message - the generic one below will be used. */ | |
1540 | ||
1541 | if (new_ok != OK && smtp_return_error_details) | |
1542 | { | |
1543 | *user_msgptr = string_sprintf("Rejected after DATA: " | |
1544 | "could not verify \"%.*s\" header address\n%s: %s", | |
1545 | endname - h->text, h->text, vaddr->address, vaddr->message); | |
1546 | } | |
1547 | ||
1548 | /* Success or defer */ | |
1549 | ||
1550 | if (new_ok == OK) return OK; | |
1551 | if (new_ok == DEFER) yield = DEFER; | |
1552 | ||
1553 | /* Move on to any more addresses in the header */ | |
1554 | ||
1555 | s = ss; | |
1556 | } | |
1557 | } | |
1558 | } | |
1559 | ||
1560 | if (yield == FAIL && *log_msgptr == NULL) | |
1561 | *log_msgptr = US"there is no valid sender in any header line"; | |
1562 | ||
1563 | if (yield == DEFER && *log_msgptr == NULL) | |
1564 | *log_msgptr = US"all attempts to verify a sender in a header line deferred"; | |
1565 | ||
1566 | return yield; | |
1567 | } | |
1568 | ||
1569 | ||
1570 | ||
1571 | ||
1572 | /************************************************* | |
1573 | * Get RFC 1413 identification * | |
1574 | *************************************************/ | |
1575 | ||
1576 | /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If | |
1577 | the timeout is set to zero, then the query is not done. There may also be lists | |
1578 | of hosts and nets which are exempt. To guard against malefactors sending | |
1579 | non-printing characters which could, for example, disrupt a message's headers, | |
1580 | make sure the string consists of printing characters only. | |
1581 | ||
1582 | Argument: | |
1583 | port the port to connect to; usually this is IDENT_PORT (113), but when | |
1584 | running in the test harness with -bh a different value is used. | |
1585 | ||
1586 | Returns: nothing | |
1587 | ||
1588 | Side effect: any received ident value is put in sender_ident (NULL otherwise) | |
1589 | */ | |
1590 | ||
1591 | void | |
1592 | verify_get_ident(int port) | |
1593 | { | |
1594 | int sock, host_af, qlen; | |
1595 | int received_sender_port, received_interface_port, n; | |
1596 | uschar *p; | |
1597 | uschar buffer[2048]; | |
1598 | ||
1599 | /* Default is no ident. Check whether we want to do an ident check for this | |
1600 | host. */ | |
1601 | ||
1602 | sender_ident = NULL; | |
1603 | if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK) | |
1604 | return; | |
1605 | ||
1606 | DEBUG(D_ident) debug_printf("doing ident callback\n"); | |
1607 | ||
1608 | /* Set up a connection to the ident port of the remote host. Bind the local end | |
1609 | to the incoming interface address. If the sender host address is an IPv6 | |
1610 | address, the incoming interface address will also be IPv6. */ | |
1611 | ||
1612 | host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6; | |
1613 | sock = ip_socket(SOCK_STREAM, host_af); | |
1614 | if (sock < 0) return; | |
1615 | ||
1616 | if (ip_bind(sock, host_af, interface_address, 0) < 0) | |
1617 | { | |
1618 | DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n", | |
1619 | strerror(errno)); | |
1620 | goto END_OFF; | |
1621 | } | |
1622 | ||
1623 | if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout) | |
1624 | < 0) | |
1625 | { | |
1626 | if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0) | |
1627 | { | |
1628 | log_write(0, LOG_MAIN, "ident connection to %s timed out", | |
1629 | sender_host_address); | |
1630 | } | |
1631 | else | |
1632 | { | |
1633 | DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n", | |
1634 | sender_host_address, strerror(errno)); | |
1635 | } | |
1636 | goto END_OFF; | |
1637 | } | |
1638 | ||
1639 | /* Construct and send the query. */ | |
1640 | ||
1641 | sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port); | |
1642 | qlen = Ustrlen(buffer); | |
1643 | if (send(sock, buffer, qlen, 0) < 0) | |
1644 | { | |
1645 | DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno)); | |
1646 | goto END_OFF; | |
1647 | } | |
1648 | ||
1649 | /* Read a response line. We put it into the rest of the buffer, using several | |
1650 | recv() calls if necessary. */ | |
1651 | ||
1652 | p = buffer + qlen; | |
1653 | ||
1654 | for (;;) | |
1655 | { | |
1656 | uschar *pp; | |
1657 | int count; | |
1658 | int size = sizeof(buffer) - (p - buffer); | |
1659 | ||
1660 | if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */ | |
1661 | count = ip_recv(sock, p, size, rfc1413_query_timeout); | |
1662 | if (count <= 0) goto END_OFF; /* Read error or EOF */ | |
1663 | ||
1664 | /* Scan what we just read, to see if we have reached the terminating \r\n. Be | |
1665 | generous, and accept a plain \n terminator as well. The only illegal | |
1666 | character is 0. */ | |
1667 | ||
1668 | for (pp = p; pp < p + count; pp++) | |
1669 | { | |
1670 | if (*pp == 0) goto END_OFF; /* Zero octet not allowed */ | |
1671 | if (*pp == '\n') | |
1672 | { | |
1673 | if (pp[-1] == '\r') pp--; | |
1674 | *pp = 0; | |
1675 | goto GOT_DATA; /* Break out of both loops */ | |
1676 | } | |
1677 | } | |
1678 | ||
1679 | /* Reached the end of the data without finding \n. Let the loop continue to | |
1680 | read some more, if there is room. */ | |
1681 | ||
1682 | p = pp; | |
1683 | } | |
1684 | ||
1685 | GOT_DATA: | |
1686 | ||
1687 | /* We have received a line of data. Check it carefully. It must start with the | |
1688 | same two port numbers that we sent, followed by data as defined by the RFC. For | |
1689 | example, | |
1690 | ||
1691 | 12345 , 25 : USERID : UNIX :root | |
1692 | ||
1693 | However, the amount of white space may be different to what we sent. In the | |
1694 | "osname" field there may be several sub-fields, comma separated. The data we | |
1695 | actually want to save follows the third colon. Some systems put leading spaces | |
1696 | in it - we discard those. */ | |
1697 | ||
1698 | if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port, | |
1699 | &received_interface_port, &n) != 2 || | |
1700 | received_sender_port != sender_host_port || | |
1701 | received_interface_port != interface_port) | |
1702 | goto END_OFF; | |
1703 | ||
1704 | p = buffer + qlen + n; | |
1705 | while(isspace(*p)) p++; | |
1706 | if (*p++ != ':') goto END_OFF; | |
1707 | while(isspace(*p)) p++; | |
1708 | if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF; | |
1709 | p += 6; | |
1710 | while(isspace(*p)) p++; | |
1711 | if (*p++ != ':') goto END_OFF; | |
1712 | while (*p != 0 && *p != ':') p++; | |
1713 | if (*p++ == 0) goto END_OFF; | |
1714 | while(isspace(*p)) p++; | |
1715 | if (*p == 0) goto END_OFF; | |
1716 | ||
1717 | /* The rest of the line is the data we want. We turn it into printing | |
1718 | characters when we save it, so that it cannot mess up the format of any logging | |
1719 | or Received: lines into which it gets inserted. We keep a maximum of 127 | |
1720 | characters. */ | |
1721 | ||
1722 | sender_ident = string_printing(string_copyn(p, 127)); | |
1723 | DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident); | |
1724 | ||
1725 | END_OFF: | |
1726 | close(sock); | |
1727 | return; | |
1728 | } | |
1729 | ||
1730 | ||
1731 | ||
1732 | ||
1733 | /************************************************* | |
1734 | * Match host to a single host-list item * | |
1735 | *************************************************/ | |
1736 | ||
1737 | /* This function compares a host (name or address) against a single item | |
1738 | from a host list. The host name gets looked up if it is needed and is not | |
1739 | already known. The function is called from verify_check_this_host() via | |
1740 | match_check_list(), which is why most of its arguments are in a single block. | |
1741 | ||
1742 | Arguments: | |
1743 | arg the argument block (see below) | |
1744 | ss the host-list item | |
1745 | valueptr where to pass back looked up data, or NULL | |
1746 | error for error message when returning ERROR | |
1747 | ||
1748 | The block contains: | |
1749 | host_name the host name or NULL, implying use sender_host_name and | |
1750 | sender_host_aliases, looking them up if required | |
1751 | host_address the host address | |
1752 | host_ipv4 the IPv4 address taken from an IPv6 one | |
1753 | ||
1754 | Returns: OK matched | |
1755 | FAIL did not match | |
1756 | DEFER lookup deferred | |
1757 | ERROR failed to find the host name or IP address | |
1758 | unknown lookup type specified | |
1759 | */ | |
1760 | ||
1761 | static int | |
1762 | check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error) | |
1763 | { | |
1764 | check_host_block *cb = (check_host_block *)arg; | |
1765 | int maskoffset; | |
1766 | BOOL isquery = FALSE; | |
1767 | uschar *semicolon, *t; | |
1768 | uschar **aliases; | |
1769 | ||
1770 | /* Optimize for the special case when the pattern is "*". */ | |
1771 | ||
1772 | if (*ss == '*' && ss[1] == 0) return OK; | |
1773 | ||
1774 | /* If the pattern is empty, it matches only in the case when there is no host - | |
1775 | this can occur in ACL checking for SMTP input using the -bs option. In this | |
1776 | situation, the host address is the empty string. */ | |
1777 | ||
1778 | if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL; | |
1779 | if (*ss == 0) return FAIL; | |
1780 | ||
1781 | /* If the pattern is precisely "@" then match against the primary host name; | |
1782 | if it's "@[]" match against the local host's IP addresses. */ | |
1783 | ||
1784 | if (*ss == '@') | |
1785 | { | |
1786 | if (ss[1] == 0) ss = primary_hostname; | |
1787 | else if (Ustrcmp(ss, "@[]") == 0) | |
1788 | { | |
1789 | ip_address_item *ip; | |
1790 | for (ip = host_find_interfaces(); ip != NULL; ip = ip->next) | |
1791 | if (Ustrcmp(ip->address, cb->host_address) == 0) return OK; | |
1792 | return FAIL; | |
1793 | } | |
1794 | } | |
1795 | ||
1796 | /* If the pattern is an IP address, optionally followed by a bitmask count, do | |
1797 | a (possibly masked) comparision with the current IP address. */ | |
1798 | ||
1799 | if (string_is_ip_address(ss, &maskoffset)) | |
1800 | return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL); | |
1801 | ||
1802 | /* If the item is of the form net[n]-lookup;<file|query> then it is a lookup on | |
1803 | a masked IP network, in textual form. The net- stuff really only applies to | |
1804 | single-key lookups where the key is implicit. For query-style lookups the key | |
1805 | is specified in the query. From release 4.30, the use of net- for query style | |
1806 | is no longer needed, but we retain it for backward compatibility. */ | |
1807 | ||
1808 | if (Ustrncmp(ss, "net", 3) == 0 && (semicolon = Ustrchr(ss, ';')) != NULL) | |
1809 | { | |
1810 | int mlen = 0; | |
1811 | for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0'; | |
1812 | if (*t++ == '-') | |
1813 | { | |
1814 | int insize; | |
1815 | int search_type; | |
1816 | int incoming[4]; | |
1817 | void *handle; | |
1818 | uschar *filename, *key, *result; | |
1819 | uschar buffer[64]; | |
1820 | ||
1821 | /* If no mask was supplied, set a negative value */ | |
1822 | ||
1823 | if (mlen == 0 && t == ss+4) mlen = -1; | |
1824 | ||
1825 | /* Find the search type */ | |
1826 | ||
1827 | search_type = search_findtype(t, semicolon - t); | |
1828 | ||
1829 | if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", | |
1830 | search_error_message); | |
1831 | ||
1832 | /* Adjust parameters for the type of lookup. For a query-style | |
1833 | lookup, there is no file name, and the "key" is just the query. For | |
1834 | a single-key lookup, the key is the current IP address, masked | |
1835 | appropriately, and reconverted to text form, with the mask appended. */ | |
1836 | ||
1837 | if (mac_islookup(search_type, lookup_querystyle)) | |
1838 | { | |
1839 | filename = NULL; | |
1840 | key = semicolon + 1; | |
1841 | } | |
1842 | else | |
1843 | { | |
1844 | insize = host_aton(cb->host_address, incoming); | |
1845 | host_mask(insize, incoming, mlen); | |
1846 | (void)host_nmtoa(insize, incoming, mlen, buffer); | |
1847 | key = buffer; | |
1848 | filename = semicolon + 1; | |
1849 | } | |
1850 | ||
1851 | /* Now do the actual lookup; note that there is no search_close() because | |
1852 | of the caching arrangements. */ | |
1853 | ||
1854 | handle = search_open(filename, search_type, 0, NULL, NULL); | |
1855 | if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", | |
1856 | search_error_message); | |
1857 | result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL); | |
1858 | if (valueptr != NULL) *valueptr = result; | |
1859 | return (result != NULL)? OK : search_find_defer? DEFER: FAIL; | |
1860 | } | |
1861 | } | |
1862 | ||
1863 | /* The pattern is not an IP address or network reference of any kind. That is, | |
1864 | it is a host name pattern. Check the characters of the pattern to see if they | |
1865 | comprise only letters, digits, full stops, and hyphens (the constituents of | |
1866 | domain names). Allow underscores, as they are all too commonly found. Sigh. | |
1867 | Also, if allow_utf8_domains is set, allow top-bit characters. */ | |
1868 | ||
1869 | for (t = ss; *t != 0; t++) | |
1870 | if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' && | |
1871 | (!allow_utf8_domains || *t < 128)) break; | |
1872 | ||
1873 | /* If the pattern is a complete domain name, with no fancy characters, look up | |
1874 | its IP address and match against that. Note that a multi-homed host will add | |
1875 | items to the chain. */ | |
1876 | ||
1877 | if (*t == 0) | |
1878 | { | |
1879 | int rc; | |
1880 | host_item h; | |
1881 | h.next = NULL; | |
1882 | h.name = ss; | |
1883 | h.address = NULL; | |
1884 | h.mx = MX_NONE; | |
1885 | rc = host_find_byname(&h, NULL, NULL, FALSE); | |
1886 | if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL) | |
1887 | { | |
1888 | host_item *hh; | |
1889 | for (hh = &h; hh != NULL; hh = hh->next) | |
1890 | { | |
1891 | if (Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)? | |
1892 | cb->host_ipv4 : cb->host_address) == 0) | |
1893 | return OK; | |
1894 | } | |
1895 | return FAIL; | |
1896 | } | |
1897 | if (rc == HOST_FIND_AGAIN) return DEFER; | |
1898 | *error = string_sprintf("failed to find IP address for %s", ss); | |
1899 | return ERROR; | |
1900 | } | |
1901 | ||
1902 | /* Almost all subsequent comparisons require the host name, and can be done | |
1903 | using the general string matching function. When this function is called for | |
1904 | outgoing hosts, the name is always given explicitly. If it is NULL, it means we | |
1905 | must use sender_host_name and its aliases, looking them up if necessary. */ | |
1906 | ||
1907 | if (cb->host_name != NULL) /* Explicit host name given */ | |
1908 | return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE, | |
1909 | valueptr); | |
1910 | ||
1911 | /* Host name not given; in principle we need the sender host name and its | |
1912 | aliases. However, for query-style lookups, we do not need the name if the | |
1913 | query does not contain $sender_host_name. From release 4.23, a reference to | |
1914 | $sender_host_name causes it to be looked up, so we don't need to do the lookup | |
1915 | on spec. */ | |
1916 | ||
1917 | if ((semicolon = Ustrchr(ss, ';')) != NULL) | |
1918 | { | |
1919 | uschar *affix; | |
1920 | int partial, affixlen, starflags, id; | |
1921 | ||
1922 | *semicolon = 0; | |
1923 | id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags); | |
1924 | *semicolon=';'; | |
1925 | ||
1926 | if (id < 0) /* Unknown lookup type */ | |
1927 | { | |
1928 | log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"", | |
1929 | search_error_message, ss); | |
1930 | return DEFER; | |
1931 | } | |
1932 | isquery = mac_islookup(id, lookup_querystyle); | |
1933 | } | |
1934 | ||
1935 | if (isquery) | |
1936 | { | |
1937 | switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr)) | |
1938 | { | |
1939 | case OK: return OK; | |
1940 | case DEFER: return DEFER; | |
1941 | default: return FAIL; | |
1942 | } | |
1943 | } | |
1944 | ||
1945 | /* Not a query-style lookup; must ensure the host name is present, and then we | |
1946 | do a check on the name and all its aliases. */ | |
1947 | ||
1948 | if (sender_host_name == NULL) | |
1949 | { | |
1950 | HDEBUG(D_host_lookup) | |
1951 | debug_printf("sender host name required, to match against %s\n", ss); | |
1952 | if (host_lookup_failed || host_name_lookup() != OK) | |
1953 | { | |
1954 | *error = string_sprintf("failed to find host name for %s", | |
1955 | sender_host_address);; | |
1956 | return ERROR; | |
1957 | } | |
1958 | host_build_sender_fullhost(); | |
1959 | } | |
1960 | ||
1961 | /* Match on the sender host name, using the general matching function */ | |
1962 | ||
1963 | switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE, | |
1964 | valueptr)) | |
1965 | { | |
1966 | case OK: return OK; | |
1967 | case DEFER: return DEFER; | |
1968 | } | |
1969 | ||
1970 | /* If there are aliases, try matching on them. */ | |
1971 | ||
1972 | aliases = sender_host_aliases; | |
1973 | while (*aliases != NULL) | |
1974 | { | |
1975 | switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr)) | |
1976 | { | |
1977 | case OK: return OK; | |
1978 | case DEFER: return DEFER; | |
1979 | } | |
1980 | } | |
1981 | return FAIL; | |
1982 | } | |
1983 | ||
1984 | ||
1985 | ||
1986 | ||
1987 | /************************************************* | |
1988 | * Check a specific host matches a host list * | |
1989 | *************************************************/ | |
1990 | ||
1991 | /* This function is passed a host list containing items in a number of | |
1992 | different formats and the identity of a host. Its job is to determine whether | |
1993 | the given host is in the set of hosts defined by the list. The host name is | |
1994 | passed as a pointer so that it can be looked up if needed and not already | |
1995 | known. This is commonly the case when called from verify_check_host() to check | |
1996 | an incoming connection. When called from elsewhere the host name should usually | |
1997 | be set. | |
1998 | ||
1999 | This function is now just a front end to match_check_list(), which runs common | |
2000 | code for scanning a list. We pass it the check_host() function to perform a | |
2001 | single test. | |
2002 | ||
2003 | Arguments: | |
2004 | listptr pointer to the host list | |
2005 | cache_bits pointer to cache for named lists, or NULL | |
2006 | host_name the host name or NULL, implying use sender_host_name and | |
2007 | sender_host_aliases, looking them up if required | |
2008 | host_address the IP address | |
2009 | valueptr if not NULL, data from a lookup is passed back here | |
2010 | ||
2011 | Returns: OK if the host is in the defined set | |
2012 | FAIL if the host is not in the defined set, | |
2013 | DEFER if a data lookup deferred (not a host lookup) | |
2014 | ||
2015 | If the host name was needed in order to make a comparison, and could not be | |
2016 | determined from the IP address, the result is FAIL unless the item | |
2017 | "+allow_unknown" was met earlier in the list, in which case OK is returned. */ | |
2018 | ||
2019 | int | |
2020 | verify_check_this_host(uschar **listptr, unsigned int *cache_bits, | |
2021 | uschar *host_name, uschar *host_address, uschar **valueptr) | |
2022 | { | |
2023 | unsigned int *local_cache_bits = cache_bits; | |
2024 | check_host_block cb; | |
2025 | cb.host_name = host_name; | |
2026 | cb.host_address = host_address; | |
2027 | ||
2028 | if (valueptr != NULL) *valueptr = NULL; | |
2029 | ||
2030 | /* If the host address starts off ::ffff: it is an IPv6 address in | |
2031 | IPv4-compatible mode. Find the IPv4 part for checking against IPv4 | |
2032 | addresses. */ | |
2033 | ||
2034 | cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)? | |
2035 | host_address + 7 : host_address; | |
2036 | ||
2037 | return match_check_list(listptr, 0, &hostlist_anchor, &local_cache_bits, | |
2038 | check_host, &cb, MCL_HOST, | |
2039 | (host_address == sender_host_address)? US"host" : host_address, valueptr); | |
2040 | } | |
2041 | ||
2042 | ||
2043 | ||
2044 | ||
2045 | /************************************************* | |
2046 | * Check the remote host matches a list * | |
2047 | *************************************************/ | |
2048 | ||
2049 | /* This is a front end to verify_check_this_host(), created because checking | |
2050 | the remote host is a common occurrence. With luck, a good compiler will spot | |
2051 | the tail recursion and optimize it. If there's no host address, this is | |
2052 | command-line SMTP input - check against an empty string for the address. | |
2053 | ||
2054 | Arguments: | |
2055 | listptr pointer to the host list | |
2056 | ||
2057 | Returns: the yield of verify_check_this_host(), | |
2058 | i.e. OK, FAIL, or DEFER | |
2059 | */ | |
2060 | ||
2061 | int | |
2062 | verify_check_host(uschar **listptr) | |
2063 | { | |
2064 | return verify_check_this_host(listptr, sender_host_cache, NULL, | |
2065 | (sender_host_address == NULL)? US"" : sender_host_address, NULL); | |
2066 | } | |
2067 | ||
2068 | ||
2069 | ||
2070 | ||
2071 | ||
2072 | /************************************************* | |
2073 | * Invert an IP address for a DNS black list * | |
2074 | *************************************************/ | |
2075 | ||
2076 | /* | |
2077 | Arguments: | |
2078 | buffer where to put the answer | |
2079 | address the address to invert | |
2080 | */ | |
2081 | ||
2082 | static void | |
2083 | invert_address(uschar *buffer, uschar *address) | |
2084 | { | |
2085 | int bin[4]; | |
2086 | uschar *bptr = buffer; | |
2087 | ||
2088 | /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer | |
2089 | to the IPv4 part only. */ | |
2090 | ||
2091 | if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7; | |
2092 | ||
2093 | /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is | |
2094 | always 1. */ | |
2095 | ||
2096 | if (host_aton(address, bin) == 1) | |
2097 | { | |
2098 | int i; | |
2099 | int x = bin[0]; | |
2100 | for (i = 0; i < 4; i++) | |
2101 | { | |
2102 | sprintf(CS bptr, "%d.", x & 255); | |
2103 | while (*bptr) bptr++; | |
2104 | x >>= 8; | |
2105 | } | |
2106 | } | |
2107 | ||
2108 | /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses | |
2109 | in any DNS black lists, and the format in which they will be looked up is | |
2110 | unknown. This is just a guess. */ | |
2111 | ||
2112 | #if HAVE_IPV6 | |
2113 | else | |
2114 | { | |
2115 | int i, j; | |
2116 | for (j = 3; j >= 0; j--) | |
2117 | { | |
2118 | int x = bin[j]; | |
2119 | for (i = 0; i < 8; i++) | |
2120 | { | |
2121 | sprintf(CS bptr, "%x.", x & 15); | |
2122 | while (*bptr) bptr++; | |
2123 | x >>= 4; | |
2124 | } | |
2125 | } | |
2126 | } | |
2127 | #endif | |
2128 | } | |
2129 | ||
2130 | ||
2131 | ||
2132 | /************************************************* | |
2133 | * Check host against DNS black lists * | |
2134 | *************************************************/ | |
2135 | ||
2136 | /* This function runs checks against a list of DNS black lists, until one | |
2137 | matches. Each item on the list can be of the form | |
2138 | ||
2139 | domain=ip-address/key | |
2140 | ||
2141 | The domain is the right-most domain that is used for the query, for example, | |
2142 | blackholes.mail-abuse.org. If the IP address is present, there is a match only | |
2143 | if the DNS lookup returns a matching IP address. Several addresses may be | |
2144 | given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2. | |
2145 | ||
2146 | If no key is given, what is looked up in the domain is the inverted IP address | |
2147 | of the current client host. If a key is given, it is used to construct the | |
2148 | domain for the lookup. For example, | |
2149 | ||
2150 | dsn.rfc-ignorant.org/$sender_address_domain | |
2151 | ||
2152 | After finding a match in the DNS, the domain is placed in $dnslist_domain, and | |
2153 | then we check for a TXT record for an error message, and if found, save its | |
2154 | value in $dnslist_text. We also cache everything in a tree, to optimize | |
2155 | multiple lookups. | |
2156 | ||
2157 | Note: an address for testing RBL is 192.203.178.39 | |
2158 | Note: an address for testing DUL is 192.203.178.4 | |
2159 | Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org | |
2160 | ||
2161 | Arguments: | |
2162 | listptr the domain/address/data list | |
2163 | ||
2164 | Returns: OK successful lookup (i.e. the address is on the list), or | |
2165 | lookup deferred after +include_unknown | |
2166 | FAIL name not found, or no data found for the given type, or | |
2167 | lookup deferred after +exclude_unknown (default) | |
2168 | DEFER lookup failure, if +defer_unknown was set | |
2169 | */ | |
2170 | ||
2171 | int | |
2172 | verify_check_dnsbl(uschar **listptr) | |
2173 | { | |
2174 | int sep = 0; | |
2175 | int defer_return = FAIL; | |
2176 | int old_pool = store_pool; | |
2177 | BOOL invert_result = FALSE; | |
2178 | uschar *list = *listptr; | |
2179 | uschar *domain; | |
2180 | uschar *s; | |
2181 | uschar buffer[1024]; | |
2182 | uschar query[256]; /* DNS domain max length */ | |
2183 | uschar revadd[128]; /* Long enough for IPv6 address */ | |
2184 | ||
2185 | /* Indicate that the inverted IP address is not yet set up */ | |
2186 | ||
2187 | revadd[0] = 0; | |
2188 | ||
2189 | /* Loop through all the domains supplied, until something matches */ | |
2190 | ||
2191 | while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) | |
2192 | { | |
2193 | BOOL frc; | |
2194 | BOOL bitmask = FALSE; | |
2195 | dns_answer dnsa; | |
2196 | dns_scan dnss; | |
2197 | uschar *iplist; | |
2198 | uschar *key; | |
2199 | tree_node *t; | |
2200 | dnsbl_cache_block *cb; | |
2201 | ||
2202 | HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain); | |
2203 | ||
2204 | /* Deal with special values that change the behaviour on defer */ | |
2205 | ||
2206 | if (domain[0] == '+') | |
2207 | { | |
2208 | if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK; | |
2209 | else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL; | |
2210 | else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER; | |
2211 | else | |
2212 | log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s", | |
2213 | domain); | |
2214 | continue; | |
2215 | } | |
2216 | ||
2217 | /* See if there's explicit data to be looked up */ | |
2218 | ||
2219 | key = Ustrchr(domain, '/'); | |
2220 | if (key != NULL) *key++ = 0; | |
2221 | ||
2222 | /* See if there's a list of addresses supplied after the domain name. This is | |
2223 | introduced by an = or a & character; if preceded by ! we invert the result. | |
2224 | */ | |
2225 | ||
2226 | iplist = Ustrchr(domain, '='); | |
2227 | if (iplist == NULL) | |
2228 | { | |
2229 | bitmask = TRUE; | |
2230 | iplist = Ustrchr(domain, '&'); | |
2231 | } | |
2232 | ||
2233 | if (iplist != NULL) | |
2234 | { | |
2235 | if (iplist > domain && iplist[-1] == '!') | |
2236 | { | |
2237 | invert_result = TRUE; | |
2238 | iplist[-1] = 0; | |
2239 | } | |
2240 | *iplist++ = 0; | |
2241 | } | |
2242 | ||
2243 | /* Check that what we have left is a sensible domain name. There is no reason | |
2244 | why these domains should in fact use the same syntax as hosts and email | |
2245 | domains, but in practice they seem to. However, there is little point in | |
2246 | actually causing an error here, because that would no doubt hold up incoming | |
2247 | mail. Instead, I'll just log it. */ | |
2248 | ||
2249 | for (s = domain; *s != 0; s++) | |
2250 | { | |
2251 | if (!isalnum(*s) && *s != '-' && *s != '.') | |
2252 | { | |
2253 | log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains " | |
2254 | "strange characters - is this right?", domain); | |
2255 | break; | |
2256 | } | |
2257 | } | |
2258 | ||
2259 | /* Construct the query by adding the domain onto either the sending host | |
2260 | address, or the given key string. */ | |
2261 | ||
2262 | if (key == NULL) | |
2263 | { | |
2264 | if (sender_host_address == NULL) return FAIL; /* can never match */ | |
2265 | if (revadd[0] == 0) invert_address(revadd, sender_host_address); | |
2266 | frc = string_format(query, sizeof(query), "%s%s", revadd, domain); | |
2267 | } | |
2268 | else | |
2269 | { | |
2270 | frc = string_format(query, sizeof(query), "%s.%s", key, domain); | |
2271 | } | |
2272 | ||
2273 | if (!frc) | |
2274 | { | |
2275 | log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long " | |
2276 | "(ignored): %s...", query); | |
2277 | continue; | |
2278 | } | |
2279 | ||
2280 | /* Look for this query in the cache. */ | |
2281 | ||
2282 | t = tree_search(dnsbl_cache, query); | |
2283 | ||
2284 | /* If not cached from a previous lookup, we must do a DNS lookup, and | |
2285 | cache the result in permanent memory. */ | |
2286 | ||
2287 | if (t == NULL) | |
2288 | { | |
2289 | store_pool = POOL_PERM; | |
2290 | ||
2291 | /* In case this is the first time the DNS resolver is being used. */ | |
2292 | ||
2293 | dns_init(FALSE, FALSE); | |
2294 | ||
2295 | /* Set up a tree entry to cache the lookup */ | |
2296 | ||
2297 | t = store_get(sizeof(tree_node) + Ustrlen(query)); | |
2298 | Ustrcpy(t->name, query); | |
2299 | t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block)); | |
2300 | (void)tree_insertnode(&dnsbl_cache, t); | |
2301 | ||
2302 | /* Do the DNS loopup . */ | |
2303 | ||
2304 | HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query); | |
2305 | cb->rc = dns_basic_lookup(&dnsa, query, T_A); | |
2306 | cb->text_set = FALSE; | |
2307 | cb->text = NULL; | |
2308 | cb->rhs = NULL; | |
2309 | ||
2310 | /* If the lookup succeeded, cache the RHS address. The code allows for | |
2311 | more than one address - this was for complete generality and the possible | |
2312 | use of A6 records. However, A6 records have been reduced to experimental | |
2313 | status (August 2001) and may die out. So they may never get used at all, | |
2314 | let alone in dnsbl records. However, leave the code here, just in case. | |
2315 | ||
2316 | Quite apart from one A6 RR generating multiple addresses, there are DNS | |
2317 | lists that return more than one A record, so we must handle multiple | |
2318 | addresses generated in that way as well. */ | |
2319 | ||
2320 | if (cb->rc == DNS_SUCCEED) | |
2321 | { | |
2322 | dns_record *rr; | |
2323 | dns_address **addrp = &(cb->rhs); | |
2324 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
2325 | rr != NULL; | |
2326 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2327 | { | |
2328 | if (rr->type == T_A) | |
2329 | { | |
2330 | dns_address *da = dns_address_from_rr(&dnsa, rr); | |
2331 | if (da != NULL) | |
2332 | { | |
2333 | *addrp = da; | |
2334 | while (da->next != NULL) da = da->next; | |
2335 | addrp = &(da->next); | |
2336 | } | |
2337 | } | |
2338 | } | |
2339 | ||
2340 | /* If we didn't find any A records, change the return code. This can | |
2341 | happen when there is a CNAME record but there are no A records for what | |
2342 | it points to. */ | |
2343 | ||
2344 | if (cb->rhs == NULL) cb->rc = DNS_NODATA; | |
2345 | } | |
2346 | ||
2347 | store_pool = old_pool; | |
2348 | } | |
2349 | ||
2350 | /* Previous lookup was cached */ | |
2351 | ||
2352 | else | |
2353 | { | |
2354 | HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n"); | |
2355 | cb = t->data.ptr; | |
2356 | } | |
2357 | ||
2358 | /* We now have the result of the DNS lookup, either newly done, or cached | |
2359 | from a previous call. If the lookup succeeded, check against the address | |
2360 | list if there is one. This may be a positive equality list (introduced by | |
2361 | "="), a negative equality list (introduced by "!="), a positive bitmask | |
2362 | list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/ | |
2363 | ||
2364 | if (cb->rc == DNS_SUCCEED) | |
2365 | { | |
2366 | dns_address *da = NULL; | |
2367 | uschar *addlist = cb->rhs->address; | |
2368 | ||
2369 | /* For A and AAAA records, there may be multiple addresses from multiple | |
2370 | records. For A6 records (currently not expected to be used) there may be | |
2371 | multiple addresses from a single record. */ | |
2372 | ||
2373 | for (da = cb->rhs->next; da != NULL; da = da->next) | |
2374 | addlist = string_sprintf("%s, %s", addlist, da->address); | |
2375 | ||
2376 | HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n", | |
2377 | query, addlist); | |
2378 | ||
2379 | /* Address list check; this can be either for equality, or via a bitmask. | |
2380 | In the latter case, all the bits must match. */ | |
2381 | ||
2382 | if (iplist != NULL) | |
2383 | { | |
2384 | int ipsep = ','; | |
2385 | uschar ip[46]; | |
2386 | uschar *ptr = iplist; | |
2387 | ||
2388 | while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL) | |
2389 | { | |
2390 | /* Handle exact matching */ | |
2391 | if (!bitmask) | |
2392 | { | |
2393 | for (da = cb->rhs; da != NULL; da = da->next) | |
2394 | { | |
2395 | if (Ustrcmp(CS da->address, ip) == 0) break; | |
2396 | } | |
2397 | } | |
2398 | /* Handle bitmask matching */ | |
2399 | else | |
2400 | { | |
2401 | int address[4]; | |
2402 | int mask = 0; | |
2403 | ||
2404 | /* At present, all known DNS blocking lists use A records, with | |
2405 | IPv4 addresses on the RHS encoding the information they return. I | |
2406 | wonder if this will linger on as the last vestige of IPv4 when IPv6 | |
2407 | is ubiquitous? Anyway, for now we use paranoia code to completely | |
2408 | ignore IPv6 addresses. The default mask is 0, which always matches. | |
2409 | We change this only for IPv4 addresses in the list. */ | |
2410 | ||
2411 | if (host_aton(ip, address) == 1) mask = address[0]; | |
2412 | ||
2413 | /* Scan the returned addresses, skipping any that are IPv6 */ | |
2414 | ||
2415 | for (da = cb->rhs; da != NULL; da = da->next) | |
2416 | { | |
2417 | if (host_aton(da->address, address) != 1) continue; | |
2418 | if ((address[0] & mask) == mask) break; | |
2419 | } | |
2420 | } | |
2421 | ||
2422 | /* Break out if a match has been found */ | |
2423 | ||
2424 | if (da != NULL) break; | |
2425 | } | |
2426 | ||
2427 | /* If either | |
2428 | ||
2429 | (a) No IP address in a positive list matched, or | |
2430 | (b) An IP address in a negative list did match | |
2431 | ||
2432 | then behave as if the DNSBL lookup had not succeeded, i.e. the host is | |
2433 | not on the list. */ | |
2434 | ||
2435 | if (invert_result != (da == NULL)) | |
2436 | { | |
2437 | HDEBUG(D_dnsbl) | |
2438 | { | |
2439 | debug_printf("=> but we are not accepting this block class because\n"); | |
2440 | debug_printf("=> there was %s match for %c%s\n", | |
2441 | invert_result? "an exclude":"no", bitmask? '&' : '=', iplist); | |
2442 | } | |
2443 | continue; /* With next DNSBL domain */ | |
2444 | } | |
2445 | } | |
2446 | ||
2447 | /* Either there was no IP list, or the record matched. Look up a TXT record | |
2448 | if it hasn't previously been done. */ | |
2449 | ||
2450 | if (!cb->text_set) | |
2451 | { | |
2452 | cb->text_set = TRUE; | |
2453 | if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED) | |
2454 | { | |
2455 | dns_record *rr; | |
2456 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
2457 | rr != NULL; | |
2458 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2459 | if (rr->type == T_TXT) break; | |
2460 | if (rr != NULL) | |
2461 | { | |
2462 | int len = (rr->data)[0]; | |
2463 | if (len > 511) len = 127; | |
2464 | store_pool = POOL_PERM; | |
2465 | cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1)); | |
2466 | store_pool = old_pool; | |
2467 | } | |
2468 | } | |
2469 | } | |
2470 | ||
2471 | HDEBUG(D_dnsbl) | |
2472 | { | |
2473 | debug_printf("=> that means %s is listed at %s\n", | |
2474 | (key == NULL)? sender_host_address : key, domain); | |
2475 | } | |
2476 | ||
2477 | dnslist_domain = string_copy(domain); | |
2478 | dnslist_value = addlist; | |
2479 | dnslist_text = cb->text; | |
2480 | return OK; | |
2481 | } | |
2482 | ||
2483 | /* There was a problem with the DNS lookup */ | |
2484 | ||
2485 | if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA) | |
2486 | { | |
2487 | log_write(L_dnslist_defer, LOG_MAIN, | |
2488 | "DNS list lookup defer (probably timeout) for %s: %s", query, | |
2489 | (defer_return == OK)? US"assumed in list" : | |
2490 | (defer_return == FAIL)? US"assumed not in list" : | |
2491 | US"returned DEFER"); | |
2492 | return defer_return; | |
2493 | } | |
2494 | ||
2495 | /* No entry was found in the DNS; continue for next domain */ | |
2496 | ||
2497 | HDEBUG(D_dnsbl) | |
2498 | { | |
2499 | debug_printf("DNS lookup for %s failed\n", query); | |
2500 | debug_printf("=> that means %s is not listed at %s\n", | |
2501 | (key == NULL)? sender_host_address : key, domain); | |
2502 | } | |
2503 | } /* Continue with next domain */ | |
2504 | ||
2505 | return FAIL; | |
2506 | } | |
2507 | ||
2508 | /* End of verify.c */ |