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d4eb88df | 1 | /* $Cambridge: exim/src/src/verify.c,v 1.4 2004/11/11 11:40:36 ph10 Exp $ */ |
059ec3d9 PH |
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 | |
4deaf07d PH |
126 | callout_overall the overall callout timeout (if < 0 use 4*callout) |
127 | callout_connect the callout connection timeout (if < 0 use callout) | |
059ec3d9 PH |
128 | options the verification options - these bits are used: |
129 | vopt_is_recipient => this is a recipient address | |
130 | vopt_callout_no_cache => don't use callout cache | |
131 | vopt_callout_random => do the "random" thing | |
132 | vopt_callout_recipsender => use real sender for recipient | |
133 | vopt_callout_recippmaster => use postmaster for recipient | |
134 | se_mailfrom MAIL FROM address for sender verify; NULL => "" | |
135 | pm_mailfrom if non-NULL, do the postmaster check with this sender | |
136 | ||
137 | Returns: OK/FAIL/DEFER | |
138 | */ | |
139 | ||
140 | static int | |
141 | do_callout(address_item *addr, host_item *host_list, transport_feedback *tf, | |
4deaf07d PH |
142 | int callout, int callout_overall, int callout_connect, int options, |
143 | uschar *se_mailfrom, uschar *pm_mailfrom) | |
059ec3d9 PH |
144 | { |
145 | BOOL is_recipient = (options & vopt_is_recipient) != 0; | |
146 | BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0; | |
147 | BOOL callout_random = (options & vopt_callout_random) != 0; | |
148 | ||
149 | int yield = OK; | |
150 | BOOL done = FALSE; | |
151 | uschar *address_key; | |
152 | uschar *from_address; | |
153 | uschar *random_local_part = NULL; | |
2c7db3f5 PH |
154 | uschar **failure_ptr = is_recipient? |
155 | &recipient_verify_failure : &sender_verify_failure; | |
059ec3d9 PH |
156 | open_db dbblock; |
157 | open_db *dbm_file = NULL; | |
158 | dbdata_callout_cache new_domain_record; | |
159 | dbdata_callout_cache_address new_address_record; | |
160 | host_item *host; | |
161 | time_t callout_start_time; | |
162 | ||
163 | new_domain_record.result = ccache_unknown; | |
164 | new_domain_record.postmaster_result = ccache_unknown; | |
165 | new_domain_record.random_result = ccache_unknown; | |
166 | ||
167 | memset(&new_address_record, 0, sizeof(new_address_record)); | |
168 | ||
169 | /* For a recipient callout, the key used for the address cache record must | |
170 | include the sender address if we are using the real sender in the callout, | |
171 | because that may influence the result of the callout. */ | |
172 | ||
173 | address_key = addr->address; | |
174 | from_address = US""; | |
175 | ||
176 | if (is_recipient) | |
177 | { | |
178 | if ((options & vopt_callout_recipsender) != 0) | |
179 | { | |
180 | address_key = string_sprintf("%s/<%s>", addr->address, sender_address); | |
181 | from_address = sender_address; | |
182 | } | |
183 | else if ((options & vopt_callout_recippmaster) != 0) | |
184 | { | |
185 | address_key = string_sprintf("%s/<postmaster@%s>", addr->address, | |
186 | qualify_domain_sender); | |
187 | from_address = string_sprintf("postmaster@%s", qualify_domain_sender); | |
188 | } | |
189 | } | |
190 | ||
191 | /* For a sender callout, we must adjust the key if the mailfrom address is not | |
192 | empty. */ | |
193 | ||
194 | else | |
195 | { | |
196 | from_address = (se_mailfrom == NULL)? US"" : se_mailfrom; | |
197 | if (from_address[0] != 0) | |
198 | address_key = string_sprintf("%s/<%s>", addr->address, from_address); | |
199 | } | |
200 | ||
201 | /* Open the callout cache database, it it exists, for reading only at this | |
202 | stage, unless caching has been disabled. */ | |
203 | ||
204 | if (callout_no_cache) | |
205 | { | |
206 | HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n"); | |
207 | } | |
208 | else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL) | |
209 | { | |
210 | HDEBUG(D_verify) debug_printf("callout cache: not available\n"); | |
211 | } | |
212 | ||
213 | /* If a cache database is available see if we can avoid the need to do an | |
214 | actual callout by making use of previously-obtained data. */ | |
215 | ||
216 | if (dbm_file != NULL) | |
217 | { | |
218 | dbdata_callout_cache_address *cache_address_record; | |
219 | dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file, | |
220 | addr->domain, US"domain", | |
221 | callout_cache_domain_positive_expire, | |
222 | callout_cache_domain_negative_expire); | |
223 | ||
224 | /* If an unexpired cache record was found for this domain, see if the callout | |
225 | process can be short-circuited. */ | |
226 | ||
227 | if (cache_record != NULL) | |
228 | { | |
229 | /* If an early command (up to and including MAIL FROM:<>) was rejected, | |
230 | there is no point carrying on. The callout fails. */ | |
231 | ||
232 | if (cache_record->result == ccache_reject) | |
233 | { | |
234 | setflag(addr, af_verify_nsfail); | |
235 | HDEBUG(D_verify) | |
236 | debug_printf("callout cache: domain gave initial rejection, or " | |
237 | "does not accept HELO or MAIL FROM:<>\n"); | |
238 | setflag(addr, af_verify_nsfail); | |
239 | addr->user_message = US"(result of an earlier callout reused)."; | |
240 | yield = FAIL; | |
2c7db3f5 | 241 | *failure_ptr = US"mail"; |
059ec3d9 PH |
242 | goto END_CALLOUT; |
243 | } | |
244 | ||
245 | /* If a previous check on a "random" local part was accepted, we assume | |
246 | that the server does not do any checking on local parts. There is therefore | |
247 | no point in doing the callout, because it will always be successful. If a | |
248 | random check previously failed, arrange not to do it again, but preserve | |
249 | the data in the new record. If a random check is required but hasn't been | |
250 | done, skip the remaining cache processing. */ | |
251 | ||
252 | if (callout_random) switch(cache_record->random_result) | |
253 | { | |
254 | case ccache_accept: | |
255 | HDEBUG(D_verify) | |
256 | debug_printf("callout cache: domain accepts random addresses\n"); | |
257 | goto END_CALLOUT; /* Default yield is OK */ | |
258 | ||
259 | case ccache_reject: | |
260 | HDEBUG(D_verify) | |
261 | debug_printf("callout cache: domain rejects random addresses\n"); | |
262 | callout_random = FALSE; | |
263 | new_domain_record.random_result = ccache_reject; | |
264 | new_domain_record.random_stamp = cache_record->random_stamp; | |
265 | break; | |
266 | ||
267 | default: | |
268 | HDEBUG(D_verify) | |
269 | debug_printf("callout cache: need to check random address handling " | |
270 | "(not cached or cache expired)\n"); | |
271 | goto END_CACHE; | |
272 | } | |
273 | ||
274 | /* If a postmaster check is requested, but there was a previous failure, | |
275 | there is again no point in carrying on. If a postmaster check is required, | |
276 | but has not been done before, we are going to have to do a callout, so skip | |
277 | remaining cache processing. */ | |
278 | ||
279 | if (pm_mailfrom != NULL) | |
280 | { | |
281 | if (cache_record->postmaster_result == ccache_reject) | |
282 | { | |
283 | setflag(addr, af_verify_pmfail); | |
284 | HDEBUG(D_verify) | |
285 | debug_printf("callout cache: domain does not accept " | |
286 | "RCPT TO:<postmaster@domain>\n"); | |
287 | yield = FAIL; | |
2c7db3f5 | 288 | *failure_ptr = US"postmaster"; |
059ec3d9 PH |
289 | setflag(addr, af_verify_pmfail); |
290 | addr->user_message = US"(result of earlier verification reused)."; | |
291 | goto END_CALLOUT; | |
292 | } | |
293 | if (cache_record->postmaster_result == ccache_unknown) | |
294 | { | |
295 | HDEBUG(D_verify) | |
296 | debug_printf("callout cache: need to check RCPT " | |
297 | "TO:<postmaster@domain> (not cached or cache expired)\n"); | |
298 | goto END_CACHE; | |
299 | } | |
300 | ||
301 | /* If cache says OK, set pm_mailfrom NULL to prevent a redundant | |
302 | postmaster check if the address itself has to be checked. Also ensure | |
303 | that the value in the cache record is preserved (with its old timestamp). | |
304 | */ | |
305 | ||
306 | HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT " | |
307 | "TO:<postmaster@domain>\n"); | |
308 | pm_mailfrom = NULL; | |
309 | new_domain_record.postmaster_result = ccache_accept; | |
310 | new_domain_record.postmaster_stamp = cache_record->postmaster_stamp; | |
311 | } | |
312 | } | |
313 | ||
314 | /* We can't give a result based on information about the domain. See if there | |
315 | is an unexpired cache record for this specific address (combined with the | |
316 | sender address if we are doing a recipient callout with a non-empty sender). | |
317 | */ | |
318 | ||
319 | cache_address_record = (dbdata_callout_cache_address *) | |
320 | get_callout_cache_record(dbm_file, | |
321 | address_key, US"address", | |
322 | callout_cache_positive_expire, | |
323 | callout_cache_negative_expire); | |
324 | ||
325 | if (cache_address_record != NULL) | |
326 | { | |
327 | if (cache_address_record->result == ccache_accept) | |
328 | { | |
329 | HDEBUG(D_verify) | |
330 | debug_printf("callout cache: address record is positive\n"); | |
331 | } | |
332 | else | |
333 | { | |
334 | HDEBUG(D_verify) | |
335 | debug_printf("callout cache: address record is negative\n"); | |
336 | addr->user_message = US"Previous (cached) callout verification failure"; | |
2c7db3f5 | 337 | *failure_ptr = US"recipient"; |
059ec3d9 PH |
338 | yield = FAIL; |
339 | } | |
340 | goto END_CALLOUT; | |
341 | } | |
342 | ||
343 | /* Close the cache database while we actually do the callout for real. */ | |
344 | ||
345 | END_CACHE: | |
346 | dbfn_close(dbm_file); | |
347 | dbm_file = NULL; | |
348 | } | |
349 | ||
350 | /* The information wasn't available in the cache, so we have to do a real | |
351 | callout and save the result in the cache for next time, unless no_cache is set, | |
352 | or unless we have a previously cached negative random result. If we are to test | |
353 | with a random local part, ensure that such a local part is available. If not, | |
354 | log the fact, but carry on without randomming. */ | |
355 | ||
356 | if (callout_random && callout_random_local_part != NULL) | |
357 | { | |
358 | random_local_part = expand_string(callout_random_local_part); | |
359 | if (random_local_part == NULL) | |
360 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand " | |
361 | "callout_random_local_part: %s", expand_string_message); | |
362 | } | |
363 | ||
4deaf07d PH |
364 | /* Default the connect and overall callout timeouts if not set, and record the |
365 | time we are starting so that we can enforce it. */ | |
059ec3d9 PH |
366 | |
367 | if (callout_overall < 0) callout_overall = 4 * callout; | |
4deaf07d | 368 | if (callout_connect < 0) callout_connect = callout; |
059ec3d9 PH |
369 | callout_start_time = time(NULL); |
370 | ||
371 | /* Now make connections to the hosts and do real callouts. The list of hosts | |
372 | is passed in as an argument. */ | |
373 | ||
374 | for (host = host_list; host != NULL && !done; host = host->next) | |
375 | { | |
376 | smtp_inblock inblock; | |
377 | smtp_outblock outblock; | |
378 | int host_af; | |
379 | int port = 25; | |
380 | uschar *helo = US"HELO"; | |
381 | uschar *interface = NULL; /* Outgoing interface to use; NULL => any */ | |
382 | uschar inbuffer[4096]; | |
383 | uschar outbuffer[1024]; | |
384 | uschar responsebuffer[4096]; | |
385 | ||
386 | clearflag(addr, af_verify_pmfail); /* postmaster callout flag */ | |
387 | clearflag(addr, af_verify_nsfail); /* null sender callout flag */ | |
388 | ||
389 | /* Skip this host if we don't have an IP address for it. */ | |
390 | ||
391 | if (host->address == NULL) | |
392 | { | |
393 | DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n", | |
394 | host->name); | |
395 | continue; | |
396 | } | |
397 | ||
398 | /* Check the overall callout timeout */ | |
399 | ||
400 | if (time(NULL) - callout_start_time >= callout_overall) | |
401 | { | |
402 | HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n"); | |
403 | break; | |
404 | } | |
405 | ||
406 | /* Set IPv4 or IPv6 */ | |
407 | ||
408 | host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6; | |
409 | ||
410 | /* Expand and interpret the interface and port strings. This has to | |
411 | be delayed till now, because they may expand differently for different | |
412 | hosts. If there's a failure, log it, but carry on with the defaults. */ | |
413 | ||
414 | deliver_host = host->name; | |
415 | deliver_host_address = host->address; | |
416 | if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface, | |
417 | US"callout") || | |
418 | !smtp_get_port(tf->port, addr, &port, US"callout")) | |
419 | log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address, | |
420 | addr->message); | |
421 | deliver_host = deliver_host_address = NULL; | |
422 | ||
423 | /* Set HELO string according to the protocol */ | |
424 | ||
425 | if (Ustrcmp(tf->protocol, "lmtp") == 0) helo = US"LHLO"; | |
426 | ||
427 | HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port); | |
428 | ||
429 | /* Set up the buffer for reading SMTP response packets. */ | |
430 | ||
431 | inblock.buffer = inbuffer; | |
432 | inblock.buffersize = sizeof(inbuffer); | |
433 | inblock.ptr = inbuffer; | |
434 | inblock.ptrend = inbuffer; | |
435 | ||
436 | /* Set up the buffer for holding SMTP commands while pipelining */ | |
437 | ||
438 | outblock.buffer = outbuffer; | |
439 | outblock.buffersize = sizeof(outbuffer); | |
440 | outblock.ptr = outbuffer; | |
441 | outblock.cmd_count = 0; | |
442 | outblock.authenticating = FALSE; | |
443 | ||
444 | /* Connect to the host; on failure, just loop for the next one, but we | |
4deaf07d | 445 | set the error for the last one. Use the callout_connect timeout. */ |
059ec3d9 PH |
446 | |
447 | inblock.sock = outblock.sock = | |
4deaf07d | 448 | smtp_connect(host, host_af, port, interface, callout_connect, TRUE); |
059ec3d9 PH |
449 | if (inblock.sock < 0) |
450 | { | |
451 | addr->message = string_sprintf("could not connect to %s [%s]: %s", | |
452 | host->name, host->address, strerror(errno)); | |
453 | continue; | |
454 | } | |
455 | ||
456 | /* Wait for initial response, and then run the initial SMTP commands. The | |
457 | smtp_write_command() function leaves its command in big_buffer. This is | |
458 | used in error responses. Initialize it in case the connection is | |
459 | rejected. */ | |
460 | ||
461 | Ustrcpy(big_buffer, "initial connection"); | |
462 | ||
463 | done = | |
464 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
465 | '2', callout) && | |
466 | ||
467 | smtp_write_command(&outblock, FALSE, "%s %s\r\n", helo, | |
468 | smtp_active_hostname) >= 0 && | |
469 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
470 | '2', callout) && | |
471 | ||
472 | smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n", | |
473 | from_address) >= 0 && | |
474 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
475 | '2', callout); | |
476 | ||
477 | /* If the host gave an initial error, or does not accept HELO or MAIL | |
478 | FROM:<>, arrange to cache this information, but don't record anything for an | |
479 | I/O error or a defer. Do not cache rejections when a non-empty sender has | |
480 | been used, because that blocks the whole domain for all senders. */ | |
481 | ||
482 | if (!done) | |
483 | { | |
2c7db3f5 | 484 | *failure_ptr = US"mail"; |
059ec3d9 PH |
485 | if (errno == 0 && responsebuffer[0] == '5') |
486 | { | |
487 | setflag(addr, af_verify_nsfail); | |
488 | if (from_address[0] == 0) new_domain_record.result = ccache_reject; | |
489 | } | |
490 | } | |
491 | ||
492 | /* Otherwise, proceed to check a "random" address (if required), then the | |
493 | given address, and the postmaster address (if required). Between each check, | |
494 | issue RSET, because some servers accept only one recipient after MAIL | |
495 | FROM:<>. */ | |
496 | ||
497 | else | |
498 | { | |
499 | new_domain_record.result = ccache_accept; | |
500 | ||
501 | /* Do the random local part check first */ | |
502 | ||
503 | if (random_local_part != NULL) | |
504 | { | |
505 | uschar randombuffer[1024]; | |
506 | BOOL random_ok = | |
507 | smtp_write_command(&outblock, FALSE, | |
508 | "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part, | |
509 | addr->domain) >= 0 && | |
510 | smtp_read_response(&inblock, randombuffer, | |
511 | sizeof(randombuffer), '2', callout); | |
512 | ||
513 | /* Remember when we last did a random test */ | |
514 | ||
515 | new_domain_record.random_stamp = time(NULL); | |
516 | ||
517 | /* If accepted, we aren't going to do any further tests below. */ | |
518 | ||
519 | if (random_ok) | |
520 | { | |
521 | new_domain_record.random_result = ccache_accept; | |
522 | } | |
523 | ||
524 | /* Otherwise, cache a real negative response, and get back to the right | |
525 | state to send RCPT. Unless there's some problem such as a dropped | |
526 | connection, we expect to succeed, because the commands succeeded above. */ | |
527 | ||
528 | else if (errno == 0) | |
529 | { | |
530 | if (randombuffer[0] == '5') | |
531 | new_domain_record.random_result = ccache_reject; | |
532 | ||
533 | done = | |
534 | smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 && | |
535 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
536 | '2', callout) && | |
537 | ||
538 | smtp_write_command(&outblock, FALSE, "MAIL FROM:<>\r\n") >= 0 && | |
539 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
540 | '2', callout); | |
541 | } | |
542 | else done = FALSE; /* Some timeout/connection problem */ | |
543 | } /* Random check */ | |
544 | ||
545 | /* If the host is accepting all local parts, as determined by the "random" | |
546 | check, we don't need to waste time doing any further checking. */ | |
547 | ||
548 | if (new_domain_record.random_result != ccache_accept && done) | |
549 | { | |
550 | done = | |
551 | smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n", | |
552 | addr->address) >= 0 && | |
553 | smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), | |
554 | '2', callout); | |
555 | ||
556 | if (done) | |
557 | new_address_record.result = ccache_accept; | |
558 | else if (errno == 0 && responsebuffer[0] == '5') | |
2c7db3f5 PH |
559 | { |
560 | *failure_ptr = US"recipient"; | |
059ec3d9 | 561 | new_address_record.result = ccache_reject; |
2c7db3f5 | 562 | } |
059ec3d9 PH |
563 | |
564 | /* Do postmaster check if requested */ | |
565 | ||
566 | if (done && pm_mailfrom != NULL) | |
567 | { | |
568 | done = | |
569 | smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 && | |
570 | smtp_read_response(&inblock, responsebuffer, | |
571 | sizeof(responsebuffer), '2', callout) && | |
572 | ||
573 | smtp_write_command(&outblock, FALSE, | |
574 | "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 && | |
575 | smtp_read_response(&inblock, responsebuffer, | |
576 | sizeof(responsebuffer), '2', callout) && | |
577 | ||
578 | smtp_write_command(&outblock, FALSE, | |
579 | "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 && | |
580 | smtp_read_response(&inblock, responsebuffer, | |
581 | sizeof(responsebuffer), '2', callout); | |
582 | ||
583 | new_domain_record.postmaster_stamp = time(NULL); | |
584 | ||
585 | if (done) | |
586 | new_domain_record.postmaster_result = ccache_accept; | |
587 | else if (errno == 0 && responsebuffer[0] == '5') | |
588 | { | |
2c7db3f5 | 589 | *failure_ptr = US"postmaster"; |
059ec3d9 PH |
590 | setflag(addr, af_verify_pmfail); |
591 | new_domain_record.postmaster_result = ccache_reject; | |
592 | } | |
593 | } | |
594 | } /* Random not accepted */ | |
595 | } /* MAIL FROM:<> accepted */ | |
596 | ||
597 | /* For any failure of the main check, other than a negative response, we just | |
598 | close the connection and carry on. We can identify a negative response by the | |
599 | fact that errno is zero. For I/O errors it will be non-zero | |
600 | ||
601 | Set up different error texts for logging and for sending back to the caller | |
602 | as an SMTP response. Log in all cases, using a one-line format. For sender | |
603 | callouts, give a full response to the caller, but for recipient callouts, | |
604 | don't give the IP address because this may be an internal host whose identity | |
605 | is not to be widely broadcast. */ | |
606 | ||
607 | if (!done) | |
608 | { | |
609 | if (errno == ETIMEDOUT) | |
610 | { | |
611 | HDEBUG(D_verify) debug_printf("SMTP timeout\n"); | |
612 | } | |
613 | else if (errno == 0) | |
614 | { | |
615 | if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped"); | |
616 | ||
617 | addr->message = | |
618 | string_sprintf("response to \"%s\" from %s [%s] was: %s", | |
619 | big_buffer, host->name, host->address, | |
620 | string_printing(responsebuffer)); | |
621 | ||
622 | addr->user_message = is_recipient? | |
623 | string_sprintf("Callout verification failed:\n%s", responsebuffer) | |
624 | : | |
625 | string_sprintf("Called: %s\nSent: %s\nResponse: %s", | |
626 | host->address, big_buffer, responsebuffer); | |
627 | ||
628 | /* Hard rejection ends the process */ | |
629 | ||
630 | if (responsebuffer[0] == '5') /* Address rejected */ | |
631 | { | |
632 | yield = FAIL; | |
633 | done = TRUE; | |
634 | } | |
635 | } | |
636 | } | |
637 | ||
638 | /* End the SMTP conversation and close the connection. */ | |
639 | ||
640 | (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n"); | |
641 | close(inblock.sock); | |
642 | } /* Loop through all hosts, while !done */ | |
643 | ||
644 | /* If we get here with done == TRUE, a successful callout happened, and yield | |
645 | will be set OK or FAIL according to the response to the RCPT command. | |
646 | Otherwise, we looped through the hosts but couldn't complete the business. | |
647 | However, there may be domain-specific information to cache in both cases. | |
648 | ||
649 | The value of the result field in the new_domain record is ccache_unknown if | |
650 | there was an error before or with MAIL FROM:<>, and errno was not zero, | |
651 | implying some kind of I/O error. We don't want to write the cache in that case. | |
652 | Otherwise the value is ccache_accept or ccache_reject. */ | |
653 | ||
654 | if (!callout_no_cache && new_domain_record.result != ccache_unknown) | |
655 | { | |
656 | if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)) | |
657 | == NULL) | |
658 | { | |
659 | HDEBUG(D_verify) debug_printf("callout cache: not available\n"); | |
660 | } | |
661 | else | |
662 | { | |
663 | (void)dbfn_write(dbm_file, addr->domain, &new_domain_record, | |
664 | (int)sizeof(dbdata_callout_cache)); | |
665 | HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n" | |
666 | " result=%d postmaster=%d random=%d\n", | |
667 | new_domain_record.result, | |
668 | new_domain_record.postmaster_result, | |
669 | new_domain_record.random_result); | |
670 | } | |
671 | } | |
672 | ||
673 | /* If a definite result was obtained for the callout, cache it unless caching | |
674 | is disabled. */ | |
675 | ||
676 | if (done) | |
677 | { | |
678 | if (!callout_no_cache && new_address_record.result != ccache_unknown) | |
679 | { | |
680 | if (dbm_file == NULL) | |
681 | dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE); | |
682 | if (dbm_file == NULL) | |
683 | { | |
684 | HDEBUG(D_verify) debug_printf("no callout cache available\n"); | |
685 | } | |
686 | else | |
687 | { | |
688 | (void)dbfn_write(dbm_file, address_key, &new_address_record, | |
689 | (int)sizeof(dbdata_callout_cache_address)); | |
690 | HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n", | |
691 | (new_address_record.result == ccache_accept)? "positive" : "negative"); | |
692 | } | |
693 | } | |
694 | } /* done */ | |
695 | ||
696 | /* Failure to connect to any host, or any response other than 2xx or 5xx is a | |
697 | temporary error. If there was only one host, and a response was received, leave | |
698 | it alone if supplying details. Otherwise, give a generic response. */ | |
699 | ||
700 | else /* !done */ | |
701 | { | |
702 | uschar *dullmsg = string_sprintf("Could not complete %s verify callout", | |
703 | is_recipient? "recipient" : "sender"); | |
704 | yield = DEFER; | |
705 | ||
706 | if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg; | |
707 | ||
708 | addr->user_message = (!smtp_return_error_details)? dullmsg : | |
709 | string_sprintf("%s for <%s>.\n" | |
710 | "The mail server(s) for the domain may be temporarily unreachable, or\n" | |
711 | "they may be permanently unreachable from this server. In the latter case,\n%s", | |
712 | dullmsg, addr->address, | |
713 | is_recipient? | |
714 | "the address will never be accepted." | |
715 | : | |
716 | "you need to change the address or create an MX record for its domain\n" | |
717 | "if it is supposed to be generally accessible from the Internet.\n" | |
718 | "Talk to your mail administrator for details."); | |
719 | ||
720 | /* Force a specific error code */ | |
721 | ||
722 | addr->basic_errno = ERRNO_CALLOUTDEFER; | |
723 | } | |
724 | ||
725 | /* Come here from within the cache-reading code on fast-track exit. */ | |
726 | ||
727 | END_CALLOUT: | |
728 | if (dbm_file != NULL) dbfn_close(dbm_file); | |
729 | return yield; | |
730 | } | |
731 | ||
732 | ||
733 | ||
734 | /************************************************* | |
735 | * Copy error to toplevel address * | |
736 | *************************************************/ | |
737 | ||
738 | /* This function is used when a verify fails or defers, to ensure that the | |
739 | failure or defer information is in the original toplevel address. This applies | |
740 | when an address is redirected to a single new address, and the failure or | |
741 | deferral happens to the child address. | |
742 | ||
743 | Arguments: | |
744 | vaddr the verify address item | |
745 | addr the final address item | |
746 | yield FAIL or DEFER | |
747 | ||
748 | Returns: the value of YIELD | |
749 | */ | |
750 | ||
751 | static int | |
752 | copy_error(address_item *vaddr, address_item *addr, int yield) | |
753 | { | |
754 | if (addr != vaddr) | |
755 | { | |
756 | vaddr->message = addr->message; | |
757 | vaddr->user_message = addr->user_message; | |
758 | vaddr->basic_errno = addr->basic_errno; | |
759 | vaddr->more_errno = addr->more_errno; | |
760 | } | |
761 | return yield; | |
762 | } | |
763 | ||
764 | ||
765 | ||
766 | ||
767 | /************************************************* | |
768 | * Verify an email address * | |
769 | *************************************************/ | |
770 | ||
771 | /* This function is used both for verification (-bv and at other times) and | |
772 | address testing (-bt), which is indicated by address_test_mode being set. | |
773 | ||
774 | Arguments: | |
775 | vaddr contains the address to verify; the next field in this block | |
776 | must be NULL | |
777 | f if not NULL, write the result to this file | |
778 | options various option bits: | |
779 | vopt_fake_sender => this sender verify is not for the real | |
780 | sender (it was verify=sender=xxxx or an address from a | |
781 | header line) - rewriting must not change sender_address | |
782 | vopt_is_recipient => this is a recipient address, otherwise | |
783 | it's a sender address - this affects qualification and | |
784 | rewriting and messages from callouts | |
785 | vopt_qualify => qualify an unqualified address; else error | |
786 | vopt_expn => called from SMTP EXPN command | |
787 | ||
788 | These ones are used by do_callout() -- the options variable | |
789 | is passed to it. | |
790 | ||
791 | vopt_callout_no_cache => don't use callout cache | |
792 | vopt_callout_random => do the "random" thing | |
793 | vopt_callout_recipsender => use real sender for recipient | |
794 | vopt_callout_recippmaster => use postmaster for recipient | |
795 | ||
796 | callout if > 0, specifies that callout is required, and gives timeout | |
4deaf07d | 797 | for individual commands |
059ec3d9 PH |
798 | callout_overall if > 0, gives overall timeout for the callout function; |
799 | if < 0, a default is used (see do_callout()) | |
4deaf07d | 800 | callout_connect the connection timeout for callouts |
059ec3d9 PH |
801 | se_mailfrom when callout is requested to verify a sender, use this |
802 | in MAIL FROM; NULL => "" | |
803 | pm_mailfrom when callout is requested, if non-NULL, do the postmaster | |
804 | thing and use this as the sender address (may be "") | |
805 | ||
806 | routed if not NULL, set TRUE if routing succeeded, so we can | |
807 | distinguish between routing failed and callout failed | |
808 | ||
809 | Returns: OK address verified | |
810 | FAIL address failed to verify | |
811 | DEFER can't tell at present | |
812 | */ | |
813 | ||
814 | int | |
815 | verify_address(address_item *vaddr, FILE *f, int options, int callout, | |
4deaf07d PH |
816 | int callout_overall, int callout_connect, uschar *se_mailfrom, |
817 | uschar *pm_mailfrom, BOOL *routed) | |
059ec3d9 PH |
818 | { |
819 | BOOL allok = TRUE; | |
820 | BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0); | |
821 | BOOL is_recipient = (options & vopt_is_recipient) != 0; | |
822 | BOOL expn = (options & vopt_expn) != 0; | |
059ec3d9 PH |
823 | int i; |
824 | int yield = OK; | |
825 | int verify_type = expn? v_expn : | |
826 | address_test_mode? v_none : | |
827 | is_recipient? v_recipient : v_sender; | |
828 | address_item *addr_list; | |
829 | address_item *addr_new = NULL; | |
830 | address_item *addr_remote = NULL; | |
831 | address_item *addr_local = NULL; | |
832 | address_item *addr_succeed = NULL; | |
2c7db3f5 PH |
833 | uschar **failure_ptr = is_recipient? |
834 | &recipient_verify_failure : &sender_verify_failure; | |
059ec3d9 PH |
835 | uschar *ko_prefix, *cr; |
836 | uschar *address = vaddr->address; | |
837 | uschar *save_sender; | |
838 | uschar null_sender[] = { 0 }; /* Ensure writeable memory */ | |
839 | ||
2c7db3f5 PH |
840 | /* Clear, just in case */ |
841 | ||
842 | *failure_ptr = NULL; | |
843 | ||
059ec3d9 PH |
844 | /* Set up a prefix and suffix for error message which allow us to use the same |
845 | output statements both in EXPN mode (where an SMTP response is needed) and when | |
846 | debugging with an output file. */ | |
847 | ||
848 | if (expn) | |
849 | { | |
850 | ko_prefix = US"553 "; | |
851 | cr = US"\r"; | |
852 | } | |
853 | else ko_prefix = cr = US""; | |
854 | ||
855 | /* Add qualify domain if permitted; otherwise an unqualified address fails. */ | |
856 | ||
857 | if (parse_find_at(address) == NULL) | |
858 | { | |
859 | if ((options & vopt_qualify) == 0) | |
860 | { | |
861 | if (f != NULL) | |
862 | fprintf(f, "%sA domain is required for \"%s\"%s\n", ko_prefix, address, | |
863 | cr); | |
2c7db3f5 | 864 | *failure_ptr = US"qualify"; |
059ec3d9 PH |
865 | return FAIL; |
866 | } | |
867 | address = rewrite_address_qualify(address, is_recipient); | |
868 | } | |
869 | ||
870 | DEBUG(D_verify) | |
871 | { | |
872 | debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); | |
873 | debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address); | |
874 | } | |
875 | ||
876 | /* Rewrite and report on it. Clear the domain and local part caches - these | |
877 | may have been set by domains and local part tests during an ACL. */ | |
878 | ||
879 | if (global_rewrite_rules != NULL) | |
880 | { | |
881 | uschar *old = address; | |
882 | address = rewrite_address(address, is_recipient, FALSE, | |
883 | global_rewrite_rules, rewrite_existflags); | |
884 | if (address != old) | |
885 | { | |
886 | for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0; | |
887 | for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0; | |
888 | if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address); | |
889 | } | |
890 | } | |
891 | ||
892 | /* If this is the real sender address, we must update sender_address at | |
893 | this point, because it may be referred to in the routers. */ | |
894 | ||
895 | if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0) | |
896 | sender_address = address; | |
897 | ||
898 | /* If the address was rewritten to <> no verification can be done, and we have | |
899 | to return OK. This rewriting is permitted only for sender addresses; for other | |
900 | addresses, such rewriting fails. */ | |
901 | ||
902 | if (address[0] == 0) return OK; | |
903 | ||
904 | /* Save a copy of the sender address for re-instating if we change it to <> | |
905 | while verifying a sender address (a nice bit of self-reference there). */ | |
906 | ||
907 | save_sender = sender_address; | |
908 | ||
909 | /* Update the address structure with the possibly qualified and rewritten | |
910 | address. Set it up as the starting address on the chain of new addresses. */ | |
911 | ||
912 | vaddr->address = address; | |
913 | addr_new = vaddr; | |
914 | ||
915 | /* We need a loop, because an address can generate new addresses. We must also | |
916 | cope with generated pipes and files at the top level. (See also the code and | |
917 | comment in deliver.c.) However, it is usually the case that the router for | |
918 | user's .forward files has its verify flag turned off. | |
919 | ||
920 | If an address generates more than one child, the loop is used only when | |
921 | full_info is set, and this can only be set locally. Remote enquiries just get | |
922 | information about the top level address, not anything that it generated. */ | |
923 | ||
924 | while (addr_new != NULL) | |
925 | { | |
926 | int rc; | |
927 | address_item *addr = addr_new; | |
928 | ||
929 | addr_new = addr->next; | |
930 | addr->next = NULL; | |
931 | ||
932 | DEBUG(D_verify) | |
933 | { | |
934 | debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); | |
935 | debug_printf("Considering %s\n", addr->address); | |
936 | } | |
937 | ||
938 | /* Handle generated pipe, file or reply addresses. We don't get these | |
939 | when handling EXPN, as it does only one level of expansion. */ | |
940 | ||
941 | if (testflag(addr, af_pfr)) | |
942 | { | |
943 | allok = FALSE; | |
944 | if (f != NULL) | |
945 | { | |
946 | BOOL allow; | |
947 | ||
948 | if (addr->address[0] == '>') | |
949 | { | |
950 | allow = testflag(addr, af_allow_reply); | |
951 | fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1); | |
952 | } | |
953 | else | |
954 | { | |
955 | allow = (addr->address[0] == '|')? | |
956 | testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file); | |
957 | fprintf(f, "%s -> %s", addr->parent->address, addr->address); | |
958 | } | |
959 | ||
960 | if (addr->basic_errno == ERRNO_BADTRANSPORT) | |
961 | fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n" | |
962 | "%s\n", addr->message); | |
963 | else if (allow) | |
964 | fprintf(f, "\n transport = %s\n", addr->transport->name); | |
965 | else | |
966 | fprintf(f, " *** forbidden ***\n"); | |
967 | } | |
968 | continue; | |
969 | } | |
970 | ||
971 | /* Just in case some router parameter refers to it. */ | |
972 | ||
973 | return_path = (addr->p.errors_address != NULL)? | |
974 | addr->p.errors_address : sender_address; | |
975 | ||
976 | /* Split the address into domain and local part, handling the %-hack if | |
977 | necessary, and then route it. While routing a sender address, set | |
978 | $sender_address to <> because that is what it will be if we were trying to | |
979 | send a bounce to the sender. */ | |
980 | ||
981 | if (routed != NULL) *routed = FALSE; | |
982 | if ((rc = deliver_split_address(addr)) == OK) | |
983 | { | |
984 | if (!is_recipient) sender_address = null_sender; | |
985 | rc = route_address(addr, &addr_local, &addr_remote, &addr_new, | |
986 | &addr_succeed, verify_type); | |
987 | sender_address = save_sender; /* Put back the real sender */ | |
988 | } | |
989 | ||
990 | /* If routing an address succeeded, set the flag that remembers, for use when | |
991 | an ACL cached a sender verify (in case a callout fails). Then if routing set | |
992 | up a list of hosts or the transport has a host list, and the callout option | |
993 | is set, and we aren't in a host checking run, do the callout verification, | |
994 | and set another flag that notes that a callout happened. */ | |
995 | ||
996 | if (rc == OK) | |
997 | { | |
998 | if (routed != NULL) *routed = TRUE; | |
999 | if (callout > 0) | |
1000 | { | |
1001 | host_item *host_list = addr->host_list; | |
1002 | ||
1003 | /* Default, if no remote transport, to NULL for the interface (=> any), | |
1004 | "smtp" for the port, and "smtp" for the protocol. */ | |
1005 | ||
1006 | transport_feedback tf = { NULL, US"smtp", US"smtp", NULL, FALSE, FALSE }; | |
1007 | ||
1008 | /* If verification yielded a remote transport, we want to use that | |
1009 | transport's options, so as to mimic what would happen if we were really | |
1010 | sending a message to this address. */ | |
1011 | ||
1012 | if (addr->transport != NULL && !addr->transport->info->local) | |
1013 | { | |
1014 | (void)(addr->transport->setup)(addr->transport, addr, &tf, NULL); | |
1015 | ||
1016 | /* If the transport has hosts and the router does not, or if the | |
1017 | transport is configured to override the router's hosts, we must build a | |
1018 | host list of the transport's hosts, and find the IP addresses */ | |
1019 | ||
1020 | if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override)) | |
1021 | { | |
1022 | uschar *s; | |
1023 | ||
1024 | host_list = NULL; /* Ignore the router's hosts */ | |
1025 | ||
1026 | deliver_domain = addr->domain; | |
1027 | deliver_localpart = addr->local_part; | |
1028 | s = expand_string(tf.hosts); | |
1029 | deliver_domain = deliver_localpart = NULL; | |
1030 | ||
1031 | if (s == NULL) | |
1032 | { | |
1033 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts " | |
1034 | "\"%s\" in %s transport for callout: %s", tf.hosts, | |
1035 | addr->transport->name, expand_string_message); | |
1036 | } | |
1037 | else | |
1038 | { | |
1039 | uschar *canonical_name; | |
1040 | host_item *host; | |
1041 | host_build_hostlist(&host_list, s, tf.hosts_randomize); | |
1042 | ||
1043 | /* Just ignore failures to find a host address. If we don't manage | |
1044 | to find any addresses, the callout will defer. */ | |
1045 | ||
1046 | for (host = host_list; host != NULL; host = host->next) | |
1047 | { | |
1048 | if (tf.gethostbyname || string_is_ip_address(host->name, NULL)) | |
1049 | (void)host_find_byname(host, NULL, &canonical_name, TRUE); | |
1050 | else | |
1051 | { | |
1052 | int flags = HOST_FIND_BY_A; | |
1053 | if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE; | |
1054 | if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS; | |
1055 | (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL, | |
1056 | &canonical_name, NULL); | |
1057 | } | |
1058 | } | |
1059 | } | |
1060 | } | |
1061 | } | |
1062 | ||
2c7db3f5 PH |
1063 | /* Can only do a callout if we have at least one host! If the callout |
1064 | fails, it will have set ${sender,recipient}_verify_failure. */ | |
059ec3d9 PH |
1065 | |
1066 | if (host_list != NULL) | |
1067 | { | |
1068 | HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n"); | |
1069 | if (host_checking && !host_checking_callout) | |
1070 | { | |
1071 | HDEBUG(D_verify) | |
1072 | debug_printf("... callout omitted by default when host testing\n" | |
1073 | "(Use -bhc if you want the callouts to happen.)\n"); | |
1074 | } | |
1075 | else | |
1076 | { | |
1077 | rc = do_callout(addr, host_list, &tf, callout, callout_overall, | |
4deaf07d | 1078 | callout_connect, options, se_mailfrom, pm_mailfrom); |
059ec3d9 PH |
1079 | } |
1080 | } | |
1081 | else | |
1082 | { | |
1083 | HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor " | |
1084 | "transport provided a host list\n"); | |
1085 | } | |
1086 | } | |
1087 | } | |
2c7db3f5 PH |
1088 | |
1089 | /* Otherwise, any failure is a routing failure */ | |
1090 | ||
1091 | else *failure_ptr = US"route"; | |
059ec3d9 PH |
1092 | |
1093 | /* A router may return REROUTED if it has set up a child address as a result | |
1094 | of a change of domain name (typically from widening). In this case we always | |
1095 | want to continue to verify the new child. */ | |
1096 | ||
1097 | if (rc == REROUTED) continue; | |
1098 | ||
1099 | /* Handle hard failures */ | |
1100 | ||
1101 | if (rc == FAIL) | |
1102 | { | |
1103 | allok = FALSE; | |
1104 | if (f != NULL) | |
1105 | { | |
1106 | fprintf(f, "%s%s %s", ko_prefix, address, | |
1107 | address_test_mode? "is undeliverable" : "failed to verify"); | |
1108 | if (!expn && admin_user) | |
1109 | { | |
1110 | if (addr->basic_errno > 0) | |
1111 | fprintf(f, ": %s", strerror(addr->basic_errno)); | |
1112 | if (addr->message != NULL) | |
1113 | fprintf(f, ":\n %s", addr->message); | |
1114 | } | |
1115 | fprintf(f, "%s\n", cr); | |
1116 | } | |
1117 | ||
1118 | if (!full_info) return copy_error(vaddr, addr, FAIL); | |
1119 | else yield = FAIL; | |
1120 | } | |
1121 | ||
1122 | /* Soft failure */ | |
1123 | ||
1124 | else if (rc == DEFER) | |
1125 | { | |
1126 | allok = FALSE; | |
1127 | if (f != NULL) | |
1128 | { | |
1129 | fprintf(f, "%s%s cannot be resolved at this time", ko_prefix, address); | |
1130 | if (!expn && admin_user) | |
1131 | { | |
1132 | if (addr->basic_errno > 0) | |
1133 | fprintf(f, ":\n %s", strerror(addr->basic_errno)); | |
1134 | if (addr->message != NULL) | |
1135 | fprintf(f, ":\n %s", addr->message); | |
1136 | else if (addr->basic_errno <= 0) | |
1137 | fprintf(f, ":\n unknown error"); | |
1138 | } | |
1139 | ||
1140 | fprintf(f, "%s\n", cr); | |
1141 | } | |
1142 | if (!full_info) return copy_error(vaddr, addr, DEFER); | |
1143 | else if (yield == OK) yield = DEFER; | |
1144 | } | |
1145 | ||
1146 | /* If we are handling EXPN, we do not want to continue to route beyond | |
1147 | the top level. */ | |
1148 | ||
1149 | else if (expn) | |
1150 | { | |
1151 | uschar *ok_prefix = US"250-"; | |
1152 | if (addr_new == NULL) | |
1153 | { | |
1154 | if (addr_local == NULL && addr_remote == NULL) | |
1155 | fprintf(f, "250 mail to <%s> is discarded\r\n", address); | |
1156 | else | |
1157 | fprintf(f, "250 <%s>\r\n", address); | |
1158 | } | |
1159 | else while (addr_new != NULL) | |
1160 | { | |
1161 | address_item *addr2 = addr_new; | |
1162 | addr_new = addr2->next; | |
1163 | if (addr_new == NULL) ok_prefix = US"250 "; | |
1164 | fprintf(f, "%s<%s>\r\n", ok_prefix, addr2->address); | |
1165 | } | |
1166 | return OK; | |
1167 | } | |
1168 | ||
1169 | /* Successful routing other than EXPN. */ | |
1170 | ||
1171 | else | |
1172 | { | |
1173 | /* Handle successful routing when short info wanted. Otherwise continue for | |
1174 | other (generated) addresses. Short info is the operational case. Full info | |
1175 | can be requested only when debug_selector != 0 and a file is supplied. | |
1176 | ||
1177 | There is a conflict between the use of aliasing as an alternate email | |
1178 | address, and as a sort of mailing list. If an alias turns the incoming | |
1179 | address into just one address (e.g. J.Caesar->jc44) you may well want to | |
1180 | carry on verifying the generated address to ensure it is valid when | |
1181 | checking incoming mail. If aliasing generates multiple addresses, you | |
1182 | probably don't want to do this. Exim therefore treats the generation of | |
1183 | just a single new address as a special case, and continues on to verify the | |
1184 | generated address. */ | |
1185 | ||
1186 | if (!full_info && /* Stop if short info wanted AND */ | |
1187 | (addr_new == NULL || /* No new address OR */ | |
1188 | addr_new->next != NULL || /* More than one new address OR */ | |
1189 | testflag(addr_new, af_pfr))) /* New address is pfr */ | |
1190 | { | |
1191 | if (f != NULL) fprintf(f, "%s %s\n", address, | |
1192 | address_test_mode? "is deliverable" : "verified"); | |
1193 | ||
1194 | /* If we have carried on to verify a child address, we want the value | |
1195 | of $address_data to be that of the child */ | |
1196 | ||
1197 | vaddr->p.address_data = addr->p.address_data; | |
1198 | return OK; | |
1199 | } | |
1200 | } | |
1201 | } /* Loop for generated addresses */ | |
1202 | ||
1203 | /* Display the full results of the successful routing, including any generated | |
1204 | addresses. Control gets here only when full_info is set, which requires f not | |
1205 | to be NULL, and this occurs only when a top-level verify is called with the | |
1206 | debugging switch on. | |
1207 | ||
1208 | If there are no local and no remote addresses, and there were no pipes, files, | |
1209 | or autoreplies, and there were no errors or deferments, the message is to be | |
1210 | discarded, usually because of the use of :blackhole: in an alias file. */ | |
1211 | ||
1212 | if (allok && addr_local == NULL && addr_remote == NULL) | |
1213 | fprintf(f, "mail to %s is discarded\n", address); | |
1214 | ||
1215 | else for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++) | |
1216 | { | |
1217 | while (addr_list != NULL) | |
1218 | { | |
1219 | address_item *addr = addr_list; | |
1220 | address_item *p = addr->parent; | |
1221 | addr_list = addr->next; | |
1222 | ||
1223 | fprintf(f, "%s", CS addr->address); | |
1224 | while (p != NULL) | |
1225 | { | |
1226 | fprintf(f, "\n <-- %s", p->address); | |
1227 | p = p->parent; | |
1228 | } | |
1229 | fprintf(f, "\n "); | |
1230 | ||
1231 | /* Show router, and transport */ | |
1232 | ||
1233 | fprintf(f, "router = %s, ", addr->router->name); | |
1234 | fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" : | |
1235 | addr->transport->name); | |
1236 | ||
1237 | /* Show any hosts that are set up by a router unless the transport | |
1238 | is going to override them; fiddle a bit to get a nice format. */ | |
1239 | ||
1240 | if (addr->host_list != NULL && addr->transport != NULL && | |
1241 | !addr->transport->overrides_hosts) | |
1242 | { | |
1243 | host_item *h; | |
1244 | int maxlen = 0; | |
1245 | int maxaddlen = 0; | |
1246 | for (h = addr->host_list; h != NULL; h = h->next) | |
1247 | { | |
1248 | int len = Ustrlen(h->name); | |
1249 | if (len > maxlen) maxlen = len; | |
1250 | len = (h->address != NULL)? Ustrlen(h->address) : 7; | |
1251 | if (len > maxaddlen) maxaddlen = len; | |
1252 | } | |
1253 | for (h = addr->host_list; h != NULL; h = h->next) | |
1254 | { | |
1255 | int len = Ustrlen(h->name); | |
1256 | fprintf(f, " host %s ", h->name); | |
1257 | while (len++ < maxlen) fprintf(f, " "); | |
1258 | if (h->address != NULL) | |
1259 | { | |
1260 | fprintf(f, "[%s] ", h->address); | |
1261 | len = Ustrlen(h->address); | |
1262 | } | |
1263 | else if (!addr->transport->info->local) /* Omit [unknown] for local */ | |
1264 | { | |
1265 | fprintf(f, "[unknown] "); | |
1266 | len = 7; | |
1267 | } | |
1268 | else len = -3; | |
1269 | while (len++ < maxaddlen) fprintf(f," "); | |
1270 | if (h->mx >= 0) fprintf(f, "MX=%d", h->mx); | |
1271 | if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port); | |
1272 | if (h->status == hstatus_unusable) fprintf(f, " ** unusable **"); | |
1273 | fprintf(f, "\n"); | |
1274 | } | |
1275 | } | |
1276 | } | |
1277 | } | |
1278 | ||
2c7db3f5 PH |
1279 | /* Will be DEFER or FAIL if any one address has, only for full_info (which is |
1280 | the -bv or -bt case). */ | |
1281 | ||
1282 | return yield; | |
059ec3d9 PH |
1283 | } |
1284 | ||
1285 | ||
1286 | ||
1287 | ||
1288 | /************************************************* | |
1289 | * Check headers for syntax errors * | |
1290 | *************************************************/ | |
1291 | ||
1292 | /* This function checks those header lines that contain addresses, and verifies | |
1293 | that all the addresses therein are syntactially correct. | |
1294 | ||
1295 | Arguments: | |
1296 | msgptr where to put an error message | |
1297 | ||
1298 | Returns: OK | |
1299 | FAIL | |
1300 | */ | |
1301 | ||
1302 | int | |
1303 | verify_check_headers(uschar **msgptr) | |
1304 | { | |
1305 | header_line *h; | |
1306 | uschar *colon, *s; | |
1307 | ||
1308 | for (h = header_list; h != NULL; h = h->next) | |
1309 | { | |
1310 | if (h->type != htype_from && | |
1311 | h->type != htype_reply_to && | |
1312 | h->type != htype_sender && | |
1313 | h->type != htype_to && | |
1314 | h->type != htype_cc && | |
1315 | h->type != htype_bcc) | |
1316 | continue; | |
1317 | ||
1318 | colon = Ustrchr(h->text, ':'); | |
1319 | s = colon + 1; | |
1320 | while (isspace(*s)) s++; | |
1321 | ||
1322 | parse_allow_group = TRUE; /* Allow group syntax */ | |
1323 | ||
1324 | /* Loop for multiple addresses in the header */ | |
1325 | ||
1326 | while (*s != 0) | |
1327 | { | |
1328 | uschar *ss = parse_find_address_end(s, FALSE); | |
1329 | uschar *recipient, *errmess; | |
1330 | int terminator = *ss; | |
1331 | int start, end, domain; | |
1332 | ||
1333 | /* Temporarily terminate the string at this point, and extract the | |
1334 | operative address within. */ | |
1335 | ||
1336 | *ss = 0; | |
1337 | recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE); | |
1338 | *ss = terminator; | |
1339 | ||
1340 | /* Permit an unqualified address only if the message is local, or if the | |
1341 | sending host is configured to be permitted to send them. */ | |
1342 | ||
1343 | if (recipient != NULL && domain == 0) | |
1344 | { | |
1345 | if (h->type == htype_from || h->type == htype_sender) | |
1346 | { | |
1347 | if (!allow_unqualified_sender) recipient = NULL; | |
1348 | } | |
1349 | else | |
1350 | { | |
1351 | if (!allow_unqualified_recipient) recipient = NULL; | |
1352 | } | |
1353 | if (recipient == NULL) errmess = US"unqualified address not permitted"; | |
1354 | } | |
1355 | ||
1356 | /* It's an error if no address could be extracted, except for the special | |
1357 | case of an empty address. */ | |
1358 | ||
1359 | if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0) | |
1360 | { | |
1361 | uschar *verb = US"is"; | |
1362 | uschar *t = ss; | |
1363 | int len; | |
1364 | ||
1365 | /* Arrange not to include any white space at the end in the | |
1366 | error message. */ | |
1367 | ||
1368 | while (t > s && isspace(t[-1])) t--; | |
1369 | ||
1370 | /* Add the address which failed to the error message, since in a | |
1371 | header with very many addresses it is sometimes hard to spot | |
1372 | which one is at fault. However, limit the amount of address to | |
1373 | quote - cases have been seen where, for example, a missing double | |
1374 | quote in a humungous To: header creates an "address" that is longer | |
1375 | than string_sprintf can handle. */ | |
1376 | ||
1377 | len = t - s; | |
1378 | if (len > 1024) | |
1379 | { | |
1380 | len = 1024; | |
1381 | verb = US"begins"; | |
1382 | } | |
1383 | ||
1384 | *msgptr = string_printing( | |
1385 | string_sprintf("%s: failing address in \"%.*s\" header %s: %.*s", | |
1386 | errmess, colon - h->text, h->text, verb, len, s)); | |
1387 | ||
1388 | return FAIL; | |
1389 | } | |
1390 | ||
1391 | /* Advance to the next address */ | |
1392 | ||
1393 | s = ss + (terminator? 1:0); | |
1394 | while (isspace(*s)) s++; | |
1395 | } /* Next address */ | |
1396 | } /* Next header */ | |
1397 | ||
1398 | return OK; | |
1399 | } | |
1400 | ||
1401 | ||
1402 | ||
1403 | ||
1404 | /************************************************* | |
1405 | * Find if verified sender * | |
1406 | *************************************************/ | |
1407 | ||
1408 | /* Usually, just a single address is verified as the sender of the message. | |
1409 | However, Exim can be made to verify other addresses as well (often related in | |
1410 | some way), and this is useful in some environments. There may therefore be a | |
1411 | chain of such addresses that have previously been tested. This function finds | |
1412 | whether a given address is on the chain. | |
1413 | ||
1414 | Arguments: the address to be verified | |
1415 | Returns: pointer to an address item, or NULL | |
1416 | */ | |
1417 | ||
1418 | address_item * | |
1419 | verify_checked_sender(uschar *sender) | |
1420 | { | |
1421 | address_item *addr; | |
1422 | for (addr = sender_verified_list; addr != NULL; addr = addr->next) | |
1423 | if (Ustrcmp(sender, addr->address) == 0) break; | |
1424 | return addr; | |
1425 | } | |
1426 | ||
1427 | ||
1428 | ||
1429 | ||
1430 | ||
1431 | /************************************************* | |
1432 | * Get valid header address * | |
1433 | *************************************************/ | |
1434 | ||
1435 | /* Scan the originator headers of the message, looking for an address that | |
1436 | verifies successfully. RFC 822 says: | |
1437 | ||
1438 | o The "Sender" field mailbox should be sent notices of | |
1439 | any problems in transport or delivery of the original | |
1440 | messages. If there is no "Sender" field, then the | |
1441 | "From" field mailbox should be used. | |
1442 | ||
1443 | o If the "Reply-To" field exists, then the reply should | |
1444 | go to the addresses indicated in that field and not to | |
1445 | the address(es) indicated in the "From" field. | |
1446 | ||
1447 | So we check a Sender field if there is one, else a Reply_to field, else a From | |
1448 | field. As some strange messages may have more than one of these fields, | |
1449 | especially if they are resent- fields, check all of them if there is more than | |
1450 | one. | |
1451 | ||
1452 | Arguments: | |
1453 | user_msgptr points to where to put a user error message | |
1454 | log_msgptr points to where to put a log error message | |
1455 | callout timeout for callout check (passed to verify_address()) | |
1456 | callout_overall overall callout timeout (ditto) | |
4deaf07d | 1457 | callout_connect connect callout timeout (ditto) |
059ec3d9 PH |
1458 | se_mailfrom mailfrom for verify; NULL => "" |
1459 | pm_mailfrom sender for pm callout check (passed to verify_address()) | |
1460 | options callout options (passed to verify_address()) | |
1461 | ||
1462 | If log_msgptr is set to something without setting user_msgptr, the caller | |
1463 | normally uses log_msgptr for both things. | |
1464 | ||
1465 | Returns: result of the verification attempt: OK, FAIL, or DEFER; | |
1466 | FAIL is given if no appropriate headers are found | |
1467 | */ | |
1468 | ||
1469 | int | |
1470 | verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr, | |
4deaf07d PH |
1471 | int callout, int callout_overall, int callout_connect, uschar *se_mailfrom, |
1472 | uschar *pm_mailfrom, int options) | |
059ec3d9 PH |
1473 | { |
1474 | static int header_types[] = { htype_sender, htype_reply_to, htype_from }; | |
1475 | int yield = FAIL; | |
1476 | int i; | |
1477 | ||
1478 | for (i = 0; i < 3; i++) | |
1479 | { | |
1480 | header_line *h; | |
1481 | for (h = header_list; h != NULL; h = h->next) | |
1482 | { | |
1483 | int terminator, new_ok; | |
1484 | uschar *s, *ss, *endname; | |
1485 | ||
1486 | if (h->type != header_types[i]) continue; | |
1487 | s = endname = Ustrchr(h->text, ':') + 1; | |
1488 | ||
1489 | while (*s != 0) | |
1490 | { | |
1491 | address_item *vaddr; | |
1492 | ||
1493 | while (isspace(*s) || *s == ',') s++; | |
1494 | if (*s == 0) break; /* End of header */ | |
1495 | ||
1496 | ss = parse_find_address_end(s, FALSE); | |
1497 | ||
1498 | /* The terminator is a comma or end of header, but there may be white | |
1499 | space preceding it (including newline for the last address). Move back | |
1500 | past any white space so we can check against any cached envelope sender | |
1501 | address verifications. */ | |
1502 | ||
1503 | while (isspace(ss[-1])) ss--; | |
1504 | terminator = *ss; | |
1505 | *ss = 0; | |
1506 | ||
1507 | HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n", | |
1508 | (int)(endname - h->text), h->text, s); | |
1509 | ||
1510 | /* See if we have already verified this address as an envelope sender, | |
1511 | and if so, use the previous answer. */ | |
1512 | ||
1513 | vaddr = verify_checked_sender(s); | |
1514 | ||
1515 | if (vaddr != NULL && /* Previously checked */ | |
1516 | (callout <= 0 || /* No callout needed; OR */ | |
1517 | vaddr->special_action > 256)) /* Callout was done */ | |
1518 | { | |
1519 | new_ok = vaddr->special_action & 255; | |
1520 | HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n"); | |
1521 | *ss = terminator; /* Restore shortened string */ | |
1522 | } | |
1523 | ||
1524 | /* Otherwise we run the verification now. We must restore the shortened | |
1525 | string before running the verification, so the headers are correct, in | |
1526 | case there is any rewriting. */ | |
1527 | ||
1528 | else | |
1529 | { | |
1530 | int start, end, domain; | |
1531 | uschar *address = parse_extract_address(s, log_msgptr, &start, | |
1532 | &end, &domain, FALSE); | |
1533 | ||
1534 | *ss = terminator; | |
1535 | ||
1536 | /* If verification failed because of a syntax error, fail this | |
1537 | function, and ensure that the failing address gets added to the error | |
1538 | message. */ | |
1539 | ||
1540 | if (address == NULL) | |
1541 | { | |
1542 | new_ok = FAIL; | |
1543 | if (*log_msgptr != NULL) | |
1544 | { | |
1545 | while (ss > s && isspace(ss[-1])) ss--; | |
1546 | *log_msgptr = string_sprintf("syntax error in '%.*s' header when " | |
1547 | "scanning for sender: %s in \"%.*s\"", | |
1548 | endname - h->text, h->text, *log_msgptr, ss - s, s); | |
1549 | return FAIL; | |
1550 | } | |
1551 | } | |
1552 | ||
1553 | /* Else go ahead with the sender verification. But is isn't *the* | |
1554 | sender of the message, so set vopt_fake_sender to stop sender_address | |
1555 | being replaced after rewriting or qualification. */ | |
1556 | ||
1557 | else | |
1558 | { | |
1559 | vaddr = deliver_make_addr(address, FALSE); | |
1560 | new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender, | |
4deaf07d PH |
1561 | callout, callout_overall, callout_connect, se_mailfrom, |
1562 | pm_mailfrom, NULL); | |
059ec3d9 PH |
1563 | } |
1564 | } | |
1565 | ||
1566 | /* We now have the result, either newly found, or cached. If we are | |
1567 | giving out error details, set a specific user error. This means that the | |
1568 | last of these will be returned to the user if all three fail. We do not | |
1569 | set a log message - the generic one below will be used. */ | |
1570 | ||
1571 | if (new_ok != OK && smtp_return_error_details) | |
1572 | { | |
1573 | *user_msgptr = string_sprintf("Rejected after DATA: " | |
1574 | "could not verify \"%.*s\" header address\n%s: %s", | |
1575 | endname - h->text, h->text, vaddr->address, vaddr->message); | |
1576 | } | |
1577 | ||
1578 | /* Success or defer */ | |
1579 | ||
1580 | if (new_ok == OK) return OK; | |
1581 | if (new_ok == DEFER) yield = DEFER; | |
1582 | ||
1583 | /* Move on to any more addresses in the header */ | |
1584 | ||
1585 | s = ss; | |
1586 | } | |
1587 | } | |
1588 | } | |
1589 | ||
1590 | if (yield == FAIL && *log_msgptr == NULL) | |
1591 | *log_msgptr = US"there is no valid sender in any header line"; | |
1592 | ||
1593 | if (yield == DEFER && *log_msgptr == NULL) | |
1594 | *log_msgptr = US"all attempts to verify a sender in a header line deferred"; | |
1595 | ||
1596 | return yield; | |
1597 | } | |
1598 | ||
1599 | ||
1600 | ||
1601 | ||
1602 | /************************************************* | |
1603 | * Get RFC 1413 identification * | |
1604 | *************************************************/ | |
1605 | ||
1606 | /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If | |
1607 | the timeout is set to zero, then the query is not done. There may also be lists | |
1608 | of hosts and nets which are exempt. To guard against malefactors sending | |
1609 | non-printing characters which could, for example, disrupt a message's headers, | |
1610 | make sure the string consists of printing characters only. | |
1611 | ||
1612 | Argument: | |
1613 | port the port to connect to; usually this is IDENT_PORT (113), but when | |
1614 | running in the test harness with -bh a different value is used. | |
1615 | ||
1616 | Returns: nothing | |
1617 | ||
1618 | Side effect: any received ident value is put in sender_ident (NULL otherwise) | |
1619 | */ | |
1620 | ||
1621 | void | |
1622 | verify_get_ident(int port) | |
1623 | { | |
1624 | int sock, host_af, qlen; | |
1625 | int received_sender_port, received_interface_port, n; | |
1626 | uschar *p; | |
1627 | uschar buffer[2048]; | |
1628 | ||
1629 | /* Default is no ident. Check whether we want to do an ident check for this | |
1630 | host. */ | |
1631 | ||
1632 | sender_ident = NULL; | |
1633 | if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK) | |
1634 | return; | |
1635 | ||
1636 | DEBUG(D_ident) debug_printf("doing ident callback\n"); | |
1637 | ||
1638 | /* Set up a connection to the ident port of the remote host. Bind the local end | |
1639 | to the incoming interface address. If the sender host address is an IPv6 | |
1640 | address, the incoming interface address will also be IPv6. */ | |
1641 | ||
1642 | host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6; | |
1643 | sock = ip_socket(SOCK_STREAM, host_af); | |
1644 | if (sock < 0) return; | |
1645 | ||
1646 | if (ip_bind(sock, host_af, interface_address, 0) < 0) | |
1647 | { | |
1648 | DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n", | |
1649 | strerror(errno)); | |
1650 | goto END_OFF; | |
1651 | } | |
1652 | ||
1653 | if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout) | |
1654 | < 0) | |
1655 | { | |
1656 | if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0) | |
1657 | { | |
1658 | log_write(0, LOG_MAIN, "ident connection to %s timed out", | |
1659 | sender_host_address); | |
1660 | } | |
1661 | else | |
1662 | { | |
1663 | DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n", | |
1664 | sender_host_address, strerror(errno)); | |
1665 | } | |
1666 | goto END_OFF; | |
1667 | } | |
1668 | ||
1669 | /* Construct and send the query. */ | |
1670 | ||
1671 | sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port); | |
1672 | qlen = Ustrlen(buffer); | |
1673 | if (send(sock, buffer, qlen, 0) < 0) | |
1674 | { | |
1675 | DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno)); | |
1676 | goto END_OFF; | |
1677 | } | |
1678 | ||
1679 | /* Read a response line. We put it into the rest of the buffer, using several | |
1680 | recv() calls if necessary. */ | |
1681 | ||
1682 | p = buffer + qlen; | |
1683 | ||
1684 | for (;;) | |
1685 | { | |
1686 | uschar *pp; | |
1687 | int count; | |
1688 | int size = sizeof(buffer) - (p - buffer); | |
1689 | ||
1690 | if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */ | |
1691 | count = ip_recv(sock, p, size, rfc1413_query_timeout); | |
1692 | if (count <= 0) goto END_OFF; /* Read error or EOF */ | |
1693 | ||
1694 | /* Scan what we just read, to see if we have reached the terminating \r\n. Be | |
1695 | generous, and accept a plain \n terminator as well. The only illegal | |
1696 | character is 0. */ | |
1697 | ||
1698 | for (pp = p; pp < p + count; pp++) | |
1699 | { | |
1700 | if (*pp == 0) goto END_OFF; /* Zero octet not allowed */ | |
1701 | if (*pp == '\n') | |
1702 | { | |
1703 | if (pp[-1] == '\r') pp--; | |
1704 | *pp = 0; | |
1705 | goto GOT_DATA; /* Break out of both loops */ | |
1706 | } | |
1707 | } | |
1708 | ||
1709 | /* Reached the end of the data without finding \n. Let the loop continue to | |
1710 | read some more, if there is room. */ | |
1711 | ||
1712 | p = pp; | |
1713 | } | |
1714 | ||
1715 | GOT_DATA: | |
1716 | ||
1717 | /* We have received a line of data. Check it carefully. It must start with the | |
1718 | same two port numbers that we sent, followed by data as defined by the RFC. For | |
1719 | example, | |
1720 | ||
1721 | 12345 , 25 : USERID : UNIX :root | |
1722 | ||
1723 | However, the amount of white space may be different to what we sent. In the | |
1724 | "osname" field there may be several sub-fields, comma separated. The data we | |
1725 | actually want to save follows the third colon. Some systems put leading spaces | |
1726 | in it - we discard those. */ | |
1727 | ||
1728 | if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port, | |
1729 | &received_interface_port, &n) != 2 || | |
1730 | received_sender_port != sender_host_port || | |
1731 | received_interface_port != interface_port) | |
1732 | goto END_OFF; | |
1733 | ||
1734 | p = buffer + qlen + n; | |
1735 | while(isspace(*p)) p++; | |
1736 | if (*p++ != ':') goto END_OFF; | |
1737 | while(isspace(*p)) p++; | |
1738 | if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF; | |
1739 | p += 6; | |
1740 | while(isspace(*p)) p++; | |
1741 | if (*p++ != ':') goto END_OFF; | |
1742 | while (*p != 0 && *p != ':') p++; | |
1743 | if (*p++ == 0) goto END_OFF; | |
1744 | while(isspace(*p)) p++; | |
1745 | if (*p == 0) goto END_OFF; | |
1746 | ||
1747 | /* The rest of the line is the data we want. We turn it into printing | |
1748 | characters when we save it, so that it cannot mess up the format of any logging | |
1749 | or Received: lines into which it gets inserted. We keep a maximum of 127 | |
1750 | characters. */ | |
1751 | ||
1752 | sender_ident = string_printing(string_copyn(p, 127)); | |
1753 | DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident); | |
1754 | ||
1755 | END_OFF: | |
1756 | close(sock); | |
1757 | return; | |
1758 | } | |
1759 | ||
1760 | ||
1761 | ||
1762 | ||
1763 | /************************************************* | |
1764 | * Match host to a single host-list item * | |
1765 | *************************************************/ | |
1766 | ||
1767 | /* This function compares a host (name or address) against a single item | |
1768 | from a host list. The host name gets looked up if it is needed and is not | |
1769 | already known. The function is called from verify_check_this_host() via | |
1770 | match_check_list(), which is why most of its arguments are in a single block. | |
1771 | ||
1772 | Arguments: | |
1773 | arg the argument block (see below) | |
1774 | ss the host-list item | |
1775 | valueptr where to pass back looked up data, or NULL | |
1776 | error for error message when returning ERROR | |
1777 | ||
1778 | The block contains: | |
1779 | host_name the host name or NULL, implying use sender_host_name and | |
1780 | sender_host_aliases, looking them up if required | |
1781 | host_address the host address | |
1782 | host_ipv4 the IPv4 address taken from an IPv6 one | |
1783 | ||
1784 | Returns: OK matched | |
1785 | FAIL did not match | |
1786 | DEFER lookup deferred | |
1787 | ERROR failed to find the host name or IP address | |
1788 | unknown lookup type specified | |
1789 | */ | |
1790 | ||
1791 | static int | |
1792 | check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error) | |
1793 | { | |
1794 | check_host_block *cb = (check_host_block *)arg; | |
1795 | int maskoffset; | |
1796 | BOOL isquery = FALSE; | |
1797 | uschar *semicolon, *t; | |
1798 | uschar **aliases; | |
1799 | ||
1800 | /* Optimize for the special case when the pattern is "*". */ | |
1801 | ||
1802 | if (*ss == '*' && ss[1] == 0) return OK; | |
1803 | ||
1804 | /* If the pattern is empty, it matches only in the case when there is no host - | |
1805 | this can occur in ACL checking for SMTP input using the -bs option. In this | |
1806 | situation, the host address is the empty string. */ | |
1807 | ||
1808 | if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL; | |
1809 | if (*ss == 0) return FAIL; | |
1810 | ||
1811 | /* If the pattern is precisely "@" then match against the primary host name; | |
1812 | if it's "@[]" match against the local host's IP addresses. */ | |
1813 | ||
1814 | if (*ss == '@') | |
1815 | { | |
1816 | if (ss[1] == 0) ss = primary_hostname; | |
1817 | else if (Ustrcmp(ss, "@[]") == 0) | |
1818 | { | |
1819 | ip_address_item *ip; | |
1820 | for (ip = host_find_interfaces(); ip != NULL; ip = ip->next) | |
1821 | if (Ustrcmp(ip->address, cb->host_address) == 0) return OK; | |
1822 | return FAIL; | |
1823 | } | |
1824 | } | |
1825 | ||
1826 | /* If the pattern is an IP address, optionally followed by a bitmask count, do | |
1827 | a (possibly masked) comparision with the current IP address. */ | |
1828 | ||
1829 | if (string_is_ip_address(ss, &maskoffset)) | |
1830 | return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL); | |
1831 | ||
1832 | /* If the item is of the form net[n]-lookup;<file|query> then it is a lookup on | |
1833 | a masked IP network, in textual form. The net- stuff really only applies to | |
1834 | single-key lookups where the key is implicit. For query-style lookups the key | |
1835 | is specified in the query. From release 4.30, the use of net- for query style | |
1836 | is no longer needed, but we retain it for backward compatibility. */ | |
1837 | ||
1838 | if (Ustrncmp(ss, "net", 3) == 0 && (semicolon = Ustrchr(ss, ';')) != NULL) | |
1839 | { | |
1840 | int mlen = 0; | |
1841 | for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0'; | |
1842 | if (*t++ == '-') | |
1843 | { | |
1844 | int insize; | |
1845 | int search_type; | |
1846 | int incoming[4]; | |
1847 | void *handle; | |
1848 | uschar *filename, *key, *result; | |
1849 | uschar buffer[64]; | |
1850 | ||
1851 | /* If no mask was supplied, set a negative value */ | |
1852 | ||
1853 | if (mlen == 0 && t == ss+4) mlen = -1; | |
1854 | ||
1855 | /* Find the search type */ | |
1856 | ||
1857 | search_type = search_findtype(t, semicolon - t); | |
1858 | ||
1859 | if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", | |
1860 | search_error_message); | |
1861 | ||
1862 | /* Adjust parameters for the type of lookup. For a query-style | |
1863 | lookup, there is no file name, and the "key" is just the query. For | |
1864 | a single-key lookup, the key is the current IP address, masked | |
1865 | appropriately, and reconverted to text form, with the mask appended. */ | |
1866 | ||
1867 | if (mac_islookup(search_type, lookup_querystyle)) | |
1868 | { | |
1869 | filename = NULL; | |
1870 | key = semicolon + 1; | |
1871 | } | |
1872 | else | |
1873 | { | |
1874 | insize = host_aton(cb->host_address, incoming); | |
1875 | host_mask(insize, incoming, mlen); | |
1876 | (void)host_nmtoa(insize, incoming, mlen, buffer); | |
1877 | key = buffer; | |
1878 | filename = semicolon + 1; | |
1879 | } | |
1880 | ||
1881 | /* Now do the actual lookup; note that there is no search_close() because | |
1882 | of the caching arrangements. */ | |
1883 | ||
1884 | handle = search_open(filename, search_type, 0, NULL, NULL); | |
1885 | if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", | |
1886 | search_error_message); | |
1887 | result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL); | |
1888 | if (valueptr != NULL) *valueptr = result; | |
1889 | return (result != NULL)? OK : search_find_defer? DEFER: FAIL; | |
1890 | } | |
1891 | } | |
1892 | ||
1893 | /* The pattern is not an IP address or network reference of any kind. That is, | |
1894 | it is a host name pattern. Check the characters of the pattern to see if they | |
1895 | comprise only letters, digits, full stops, and hyphens (the constituents of | |
1896 | domain names). Allow underscores, as they are all too commonly found. Sigh. | |
1897 | Also, if allow_utf8_domains is set, allow top-bit characters. */ | |
1898 | ||
1899 | for (t = ss; *t != 0; t++) | |
1900 | if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' && | |
1901 | (!allow_utf8_domains || *t < 128)) break; | |
1902 | ||
1903 | /* If the pattern is a complete domain name, with no fancy characters, look up | |
1904 | its IP address and match against that. Note that a multi-homed host will add | |
1905 | items to the chain. */ | |
1906 | ||
1907 | if (*t == 0) | |
1908 | { | |
1909 | int rc; | |
1910 | host_item h; | |
1911 | h.next = NULL; | |
1912 | h.name = ss; | |
1913 | h.address = NULL; | |
1914 | h.mx = MX_NONE; | |
1915 | rc = host_find_byname(&h, NULL, NULL, FALSE); | |
1916 | if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL) | |
1917 | { | |
1918 | host_item *hh; | |
1919 | for (hh = &h; hh != NULL; hh = hh->next) | |
1920 | { | |
1921 | if (Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)? | |
1922 | cb->host_ipv4 : cb->host_address) == 0) | |
1923 | return OK; | |
1924 | } | |
1925 | return FAIL; | |
1926 | } | |
1927 | if (rc == HOST_FIND_AGAIN) return DEFER; | |
1928 | *error = string_sprintf("failed to find IP address for %s", ss); | |
1929 | return ERROR; | |
1930 | } | |
1931 | ||
1932 | /* Almost all subsequent comparisons require the host name, and can be done | |
1933 | using the general string matching function. When this function is called for | |
1934 | outgoing hosts, the name is always given explicitly. If it is NULL, it means we | |
1935 | must use sender_host_name and its aliases, looking them up if necessary. */ | |
1936 | ||
1937 | if (cb->host_name != NULL) /* Explicit host name given */ | |
1938 | return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE, | |
1939 | valueptr); | |
1940 | ||
1941 | /* Host name not given; in principle we need the sender host name and its | |
1942 | aliases. However, for query-style lookups, we do not need the name if the | |
1943 | query does not contain $sender_host_name. From release 4.23, a reference to | |
1944 | $sender_host_name causes it to be looked up, so we don't need to do the lookup | |
1945 | on spec. */ | |
1946 | ||
1947 | if ((semicolon = Ustrchr(ss, ';')) != NULL) | |
1948 | { | |
1949 | uschar *affix; | |
1950 | int partial, affixlen, starflags, id; | |
1951 | ||
1952 | *semicolon = 0; | |
1953 | id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags); | |
1954 | *semicolon=';'; | |
1955 | ||
1956 | if (id < 0) /* Unknown lookup type */ | |
1957 | { | |
1958 | log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"", | |
1959 | search_error_message, ss); | |
1960 | return DEFER; | |
1961 | } | |
1962 | isquery = mac_islookup(id, lookup_querystyle); | |
1963 | } | |
1964 | ||
1965 | if (isquery) | |
1966 | { | |
1967 | switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr)) | |
1968 | { | |
1969 | case OK: return OK; | |
1970 | case DEFER: return DEFER; | |
1971 | default: return FAIL; | |
1972 | } | |
1973 | } | |
1974 | ||
1975 | /* Not a query-style lookup; must ensure the host name is present, and then we | |
1976 | do a check on the name and all its aliases. */ | |
1977 | ||
1978 | if (sender_host_name == NULL) | |
1979 | { | |
1980 | HDEBUG(D_host_lookup) | |
1981 | debug_printf("sender host name required, to match against %s\n", ss); | |
1982 | if (host_lookup_failed || host_name_lookup() != OK) | |
1983 | { | |
1984 | *error = string_sprintf("failed to find host name for %s", | |
1985 | sender_host_address);; | |
1986 | return ERROR; | |
1987 | } | |
1988 | host_build_sender_fullhost(); | |
1989 | } | |
1990 | ||
1991 | /* Match on the sender host name, using the general matching function */ | |
1992 | ||
1993 | switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE, | |
1994 | valueptr)) | |
1995 | { | |
1996 | case OK: return OK; | |
1997 | case DEFER: return DEFER; | |
1998 | } | |
1999 | ||
2000 | /* If there are aliases, try matching on them. */ | |
2001 | ||
2002 | aliases = sender_host_aliases; | |
2003 | while (*aliases != NULL) | |
2004 | { | |
2005 | switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr)) | |
2006 | { | |
2007 | case OK: return OK; | |
2008 | case DEFER: return DEFER; | |
2009 | } | |
2010 | } | |
2011 | return FAIL; | |
2012 | } | |
2013 | ||
2014 | ||
2015 | ||
2016 | ||
2017 | /************************************************* | |
2018 | * Check a specific host matches a host list * | |
2019 | *************************************************/ | |
2020 | ||
2021 | /* This function is passed a host list containing items in a number of | |
2022 | different formats and the identity of a host. Its job is to determine whether | |
2023 | the given host is in the set of hosts defined by the list. The host name is | |
2024 | passed as a pointer so that it can be looked up if needed and not already | |
2025 | known. This is commonly the case when called from verify_check_host() to check | |
2026 | an incoming connection. When called from elsewhere the host name should usually | |
2027 | be set. | |
2028 | ||
2029 | This function is now just a front end to match_check_list(), which runs common | |
2030 | code for scanning a list. We pass it the check_host() function to perform a | |
2031 | single test. | |
2032 | ||
2033 | Arguments: | |
2034 | listptr pointer to the host list | |
2035 | cache_bits pointer to cache for named lists, or NULL | |
2036 | host_name the host name or NULL, implying use sender_host_name and | |
2037 | sender_host_aliases, looking them up if required | |
2038 | host_address the IP address | |
2039 | valueptr if not NULL, data from a lookup is passed back here | |
2040 | ||
2041 | Returns: OK if the host is in the defined set | |
2042 | FAIL if the host is not in the defined set, | |
2043 | DEFER if a data lookup deferred (not a host lookup) | |
2044 | ||
2045 | If the host name was needed in order to make a comparison, and could not be | |
2046 | determined from the IP address, the result is FAIL unless the item | |
2047 | "+allow_unknown" was met earlier in the list, in which case OK is returned. */ | |
2048 | ||
2049 | int | |
2050 | verify_check_this_host(uschar **listptr, unsigned int *cache_bits, | |
2051 | uschar *host_name, uschar *host_address, uschar **valueptr) | |
2052 | { | |
d4eb88df | 2053 | int rc; |
059ec3d9 | 2054 | unsigned int *local_cache_bits = cache_bits; |
d4eb88df | 2055 | uschar *save_host_address = deliver_host_address; |
059ec3d9 PH |
2056 | check_host_block cb; |
2057 | cb.host_name = host_name; | |
2058 | cb.host_address = host_address; | |
2059 | ||
2060 | if (valueptr != NULL) *valueptr = NULL; | |
2061 | ||
2062 | /* If the host address starts off ::ffff: it is an IPv6 address in | |
2063 | IPv4-compatible mode. Find the IPv4 part for checking against IPv4 | |
2064 | addresses. */ | |
2065 | ||
2066 | cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)? | |
2067 | host_address + 7 : host_address; | |
2068 | ||
d4eb88df PH |
2069 | /* During the running of the check, put the IP address into $host_address. In |
2070 | the case of calls from the smtp transport, it will already be there. However, | |
2071 | in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on | |
2072 | the safe side, any existing setting is preserved, though as I write this | |
2073 | (November 2004) I can't see any cases where it is actually needed. */ | |
2074 | ||
2075 | deliver_host_address = host_address; | |
2076 | rc = match_check_list( | |
2077 | listptr, /* the list */ | |
2078 | 0, /* separator character */ | |
2079 | &hostlist_anchor, /* anchor pointer */ | |
2080 | &local_cache_bits, /* cache pointer */ | |
2081 | check_host, /* function for testing */ | |
2082 | &cb, /* argument for function */ | |
2083 | MCL_HOST, /* type of check */ | |
2084 | (host_address == sender_host_address)? | |
2085 | US"host" : host_address, /* text for debugging */ | |
2086 | valueptr); /* where to pass back data */ | |
2087 | deliver_host_address = save_host_address; | |
2088 | return rc; | |
059ec3d9 PH |
2089 | } |
2090 | ||
2091 | ||
2092 | ||
2093 | ||
2094 | /************************************************* | |
2095 | * Check the remote host matches a list * | |
2096 | *************************************************/ | |
2097 | ||
2098 | /* This is a front end to verify_check_this_host(), created because checking | |
2099 | the remote host is a common occurrence. With luck, a good compiler will spot | |
2100 | the tail recursion and optimize it. If there's no host address, this is | |
2101 | command-line SMTP input - check against an empty string for the address. | |
2102 | ||
2103 | Arguments: | |
2104 | listptr pointer to the host list | |
2105 | ||
2106 | Returns: the yield of verify_check_this_host(), | |
2107 | i.e. OK, FAIL, or DEFER | |
2108 | */ | |
2109 | ||
2110 | int | |
2111 | verify_check_host(uschar **listptr) | |
2112 | { | |
2113 | return verify_check_this_host(listptr, sender_host_cache, NULL, | |
2114 | (sender_host_address == NULL)? US"" : sender_host_address, NULL); | |
2115 | } | |
2116 | ||
2117 | ||
2118 | ||
2119 | ||
2120 | ||
2121 | /************************************************* | |
2122 | * Invert an IP address for a DNS black list * | |
2123 | *************************************************/ | |
2124 | ||
2125 | /* | |
2126 | Arguments: | |
2127 | buffer where to put the answer | |
2128 | address the address to invert | |
2129 | */ | |
2130 | ||
2131 | static void | |
2132 | invert_address(uschar *buffer, uschar *address) | |
2133 | { | |
2134 | int bin[4]; | |
2135 | uschar *bptr = buffer; | |
2136 | ||
2137 | /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer | |
2138 | to the IPv4 part only. */ | |
2139 | ||
2140 | if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7; | |
2141 | ||
2142 | /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is | |
2143 | always 1. */ | |
2144 | ||
2145 | if (host_aton(address, bin) == 1) | |
2146 | { | |
2147 | int i; | |
2148 | int x = bin[0]; | |
2149 | for (i = 0; i < 4; i++) | |
2150 | { | |
2151 | sprintf(CS bptr, "%d.", x & 255); | |
2152 | while (*bptr) bptr++; | |
2153 | x >>= 8; | |
2154 | } | |
2155 | } | |
2156 | ||
2157 | /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses | |
2158 | in any DNS black lists, and the format in which they will be looked up is | |
2159 | unknown. This is just a guess. */ | |
2160 | ||
2161 | #if HAVE_IPV6 | |
2162 | else | |
2163 | { | |
2164 | int i, j; | |
2165 | for (j = 3; j >= 0; j--) | |
2166 | { | |
2167 | int x = bin[j]; | |
2168 | for (i = 0; i < 8; i++) | |
2169 | { | |
2170 | sprintf(CS bptr, "%x.", x & 15); | |
2171 | while (*bptr) bptr++; | |
2172 | x >>= 4; | |
2173 | } | |
2174 | } | |
2175 | } | |
2176 | #endif | |
2177 | } | |
2178 | ||
2179 | ||
2180 | ||
2181 | /************************************************* | |
2182 | * Check host against DNS black lists * | |
2183 | *************************************************/ | |
2184 | ||
2185 | /* This function runs checks against a list of DNS black lists, until one | |
2186 | matches. Each item on the list can be of the form | |
2187 | ||
2188 | domain=ip-address/key | |
2189 | ||
2190 | The domain is the right-most domain that is used for the query, for example, | |
2191 | blackholes.mail-abuse.org. If the IP address is present, there is a match only | |
2192 | if the DNS lookup returns a matching IP address. Several addresses may be | |
2193 | given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2. | |
2194 | ||
2195 | If no key is given, what is looked up in the domain is the inverted IP address | |
2196 | of the current client host. If a key is given, it is used to construct the | |
2197 | domain for the lookup. For example, | |
2198 | ||
2199 | dsn.rfc-ignorant.org/$sender_address_domain | |
2200 | ||
2201 | After finding a match in the DNS, the domain is placed in $dnslist_domain, and | |
2202 | then we check for a TXT record for an error message, and if found, save its | |
2203 | value in $dnslist_text. We also cache everything in a tree, to optimize | |
2204 | multiple lookups. | |
2205 | ||
2206 | Note: an address for testing RBL is 192.203.178.39 | |
2207 | Note: an address for testing DUL is 192.203.178.4 | |
2208 | Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org | |
2209 | ||
2210 | Arguments: | |
2211 | listptr the domain/address/data list | |
2212 | ||
2213 | Returns: OK successful lookup (i.e. the address is on the list), or | |
2214 | lookup deferred after +include_unknown | |
2215 | FAIL name not found, or no data found for the given type, or | |
2216 | lookup deferred after +exclude_unknown (default) | |
2217 | DEFER lookup failure, if +defer_unknown was set | |
2218 | */ | |
2219 | ||
2220 | int | |
2221 | verify_check_dnsbl(uschar **listptr) | |
2222 | { | |
2223 | int sep = 0; | |
2224 | int defer_return = FAIL; | |
2225 | int old_pool = store_pool; | |
2226 | BOOL invert_result = FALSE; | |
2227 | uschar *list = *listptr; | |
2228 | uschar *domain; | |
2229 | uschar *s; | |
2230 | uschar buffer[1024]; | |
2231 | uschar query[256]; /* DNS domain max length */ | |
2232 | uschar revadd[128]; /* Long enough for IPv6 address */ | |
2233 | ||
2234 | /* Indicate that the inverted IP address is not yet set up */ | |
2235 | ||
2236 | revadd[0] = 0; | |
2237 | ||
2238 | /* Loop through all the domains supplied, until something matches */ | |
2239 | ||
2240 | while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) | |
2241 | { | |
2242 | BOOL frc; | |
2243 | BOOL bitmask = FALSE; | |
2244 | dns_answer dnsa; | |
2245 | dns_scan dnss; | |
2246 | uschar *iplist; | |
2247 | uschar *key; | |
2248 | tree_node *t; | |
2249 | dnsbl_cache_block *cb; | |
2250 | ||
2251 | HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain); | |
2252 | ||
2253 | /* Deal with special values that change the behaviour on defer */ | |
2254 | ||
2255 | if (domain[0] == '+') | |
2256 | { | |
2257 | if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK; | |
2258 | else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL; | |
2259 | else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER; | |
2260 | else | |
2261 | log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s", | |
2262 | domain); | |
2263 | continue; | |
2264 | } | |
2265 | ||
2266 | /* See if there's explicit data to be looked up */ | |
2267 | ||
2268 | key = Ustrchr(domain, '/'); | |
2269 | if (key != NULL) *key++ = 0; | |
2270 | ||
2271 | /* See if there's a list of addresses supplied after the domain name. This is | |
2272 | introduced by an = or a & character; if preceded by ! we invert the result. | |
2273 | */ | |
2274 | ||
2275 | iplist = Ustrchr(domain, '='); | |
2276 | if (iplist == NULL) | |
2277 | { | |
2278 | bitmask = TRUE; | |
2279 | iplist = Ustrchr(domain, '&'); | |
2280 | } | |
2281 | ||
2282 | if (iplist != NULL) | |
2283 | { | |
2284 | if (iplist > domain && iplist[-1] == '!') | |
2285 | { | |
2286 | invert_result = TRUE; | |
2287 | iplist[-1] = 0; | |
2288 | } | |
2289 | *iplist++ = 0; | |
2290 | } | |
2291 | ||
2292 | /* Check that what we have left is a sensible domain name. There is no reason | |
2293 | why these domains should in fact use the same syntax as hosts and email | |
2294 | domains, but in practice they seem to. However, there is little point in | |
2295 | actually causing an error here, because that would no doubt hold up incoming | |
2296 | mail. Instead, I'll just log it. */ | |
2297 | ||
2298 | for (s = domain; *s != 0; s++) | |
2299 | { | |
2300 | if (!isalnum(*s) && *s != '-' && *s != '.') | |
2301 | { | |
2302 | log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains " | |
2303 | "strange characters - is this right?", domain); | |
2304 | break; | |
2305 | } | |
2306 | } | |
2307 | ||
2308 | /* Construct the query by adding the domain onto either the sending host | |
2309 | address, or the given key string. */ | |
2310 | ||
2311 | if (key == NULL) | |
2312 | { | |
2313 | if (sender_host_address == NULL) return FAIL; /* can never match */ | |
2314 | if (revadd[0] == 0) invert_address(revadd, sender_host_address); | |
2315 | frc = string_format(query, sizeof(query), "%s%s", revadd, domain); | |
2316 | } | |
2317 | else | |
2318 | { | |
2319 | frc = string_format(query, sizeof(query), "%s.%s", key, domain); | |
2320 | } | |
2321 | ||
2322 | if (!frc) | |
2323 | { | |
2324 | log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long " | |
2325 | "(ignored): %s...", query); | |
2326 | continue; | |
2327 | } | |
2328 | ||
2329 | /* Look for this query in the cache. */ | |
2330 | ||
2331 | t = tree_search(dnsbl_cache, query); | |
2332 | ||
2333 | /* If not cached from a previous lookup, we must do a DNS lookup, and | |
2334 | cache the result in permanent memory. */ | |
2335 | ||
2336 | if (t == NULL) | |
2337 | { | |
2338 | store_pool = POOL_PERM; | |
2339 | ||
2340 | /* In case this is the first time the DNS resolver is being used. */ | |
2341 | ||
2342 | dns_init(FALSE, FALSE); | |
2343 | ||
2344 | /* Set up a tree entry to cache the lookup */ | |
2345 | ||
2346 | t = store_get(sizeof(tree_node) + Ustrlen(query)); | |
2347 | Ustrcpy(t->name, query); | |
2348 | t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block)); | |
2349 | (void)tree_insertnode(&dnsbl_cache, t); | |
2350 | ||
2351 | /* Do the DNS loopup . */ | |
2352 | ||
2353 | HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query); | |
2354 | cb->rc = dns_basic_lookup(&dnsa, query, T_A); | |
2355 | cb->text_set = FALSE; | |
2356 | cb->text = NULL; | |
2357 | cb->rhs = NULL; | |
2358 | ||
2359 | /* If the lookup succeeded, cache the RHS address. The code allows for | |
2360 | more than one address - this was for complete generality and the possible | |
2361 | use of A6 records. However, A6 records have been reduced to experimental | |
2362 | status (August 2001) and may die out. So they may never get used at all, | |
2363 | let alone in dnsbl records. However, leave the code here, just in case. | |
2364 | ||
2365 | Quite apart from one A6 RR generating multiple addresses, there are DNS | |
2366 | lists that return more than one A record, so we must handle multiple | |
2367 | addresses generated in that way as well. */ | |
2368 | ||
2369 | if (cb->rc == DNS_SUCCEED) | |
2370 | { | |
2371 | dns_record *rr; | |
2372 | dns_address **addrp = &(cb->rhs); | |
2373 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
2374 | rr != NULL; | |
2375 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2376 | { | |
2377 | if (rr->type == T_A) | |
2378 | { | |
2379 | dns_address *da = dns_address_from_rr(&dnsa, rr); | |
2380 | if (da != NULL) | |
2381 | { | |
2382 | *addrp = da; | |
2383 | while (da->next != NULL) da = da->next; | |
2384 | addrp = &(da->next); | |
2385 | } | |
2386 | } | |
2387 | } | |
2388 | ||
2389 | /* If we didn't find any A records, change the return code. This can | |
2390 | happen when there is a CNAME record but there are no A records for what | |
2391 | it points to. */ | |
2392 | ||
2393 | if (cb->rhs == NULL) cb->rc = DNS_NODATA; | |
2394 | } | |
2395 | ||
2396 | store_pool = old_pool; | |
2397 | } | |
2398 | ||
2399 | /* Previous lookup was cached */ | |
2400 | ||
2401 | else | |
2402 | { | |
2403 | HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n"); | |
2404 | cb = t->data.ptr; | |
2405 | } | |
2406 | ||
2407 | /* We now have the result of the DNS lookup, either newly done, or cached | |
2408 | from a previous call. If the lookup succeeded, check against the address | |
2409 | list if there is one. This may be a positive equality list (introduced by | |
2410 | "="), a negative equality list (introduced by "!="), a positive bitmask | |
2411 | list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/ | |
2412 | ||
2413 | if (cb->rc == DNS_SUCCEED) | |
2414 | { | |
2415 | dns_address *da = NULL; | |
2416 | uschar *addlist = cb->rhs->address; | |
2417 | ||
2418 | /* For A and AAAA records, there may be multiple addresses from multiple | |
2419 | records. For A6 records (currently not expected to be used) there may be | |
2420 | multiple addresses from a single record. */ | |
2421 | ||
2422 | for (da = cb->rhs->next; da != NULL; da = da->next) | |
2423 | addlist = string_sprintf("%s, %s", addlist, da->address); | |
2424 | ||
2425 | HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n", | |
2426 | query, addlist); | |
2427 | ||
2428 | /* Address list check; this can be either for equality, or via a bitmask. | |
2429 | In the latter case, all the bits must match. */ | |
2430 | ||
2431 | if (iplist != NULL) | |
2432 | { | |
2433 | int ipsep = ','; | |
2434 | uschar ip[46]; | |
2435 | uschar *ptr = iplist; | |
2436 | ||
2437 | while (string_nextinlist(&ptr, &ipsep, ip, sizeof(ip)) != NULL) | |
2438 | { | |
2439 | /* Handle exact matching */ | |
2440 | if (!bitmask) | |
2441 | { | |
2442 | for (da = cb->rhs; da != NULL; da = da->next) | |
2443 | { | |
2444 | if (Ustrcmp(CS da->address, ip) == 0) break; | |
2445 | } | |
2446 | } | |
2447 | /* Handle bitmask matching */ | |
2448 | else | |
2449 | { | |
2450 | int address[4]; | |
2451 | int mask = 0; | |
2452 | ||
2453 | /* At present, all known DNS blocking lists use A records, with | |
2454 | IPv4 addresses on the RHS encoding the information they return. I | |
2455 | wonder if this will linger on as the last vestige of IPv4 when IPv6 | |
2456 | is ubiquitous? Anyway, for now we use paranoia code to completely | |
2457 | ignore IPv6 addresses. The default mask is 0, which always matches. | |
2458 | We change this only for IPv4 addresses in the list. */ | |
2459 | ||
2460 | if (host_aton(ip, address) == 1) mask = address[0]; | |
2461 | ||
2462 | /* Scan the returned addresses, skipping any that are IPv6 */ | |
2463 | ||
2464 | for (da = cb->rhs; da != NULL; da = da->next) | |
2465 | { | |
2466 | if (host_aton(da->address, address) != 1) continue; | |
2467 | if ((address[0] & mask) == mask) break; | |
2468 | } | |
2469 | } | |
2470 | ||
2471 | /* Break out if a match has been found */ | |
2472 | ||
2473 | if (da != NULL) break; | |
2474 | } | |
2475 | ||
2476 | /* If either | |
2477 | ||
2478 | (a) No IP address in a positive list matched, or | |
2479 | (b) An IP address in a negative list did match | |
2480 | ||
2481 | then behave as if the DNSBL lookup had not succeeded, i.e. the host is | |
2482 | not on the list. */ | |
2483 | ||
2484 | if (invert_result != (da == NULL)) | |
2485 | { | |
2486 | HDEBUG(D_dnsbl) | |
2487 | { | |
2488 | debug_printf("=> but we are not accepting this block class because\n"); | |
2489 | debug_printf("=> there was %s match for %c%s\n", | |
2490 | invert_result? "an exclude":"no", bitmask? '&' : '=', iplist); | |
2491 | } | |
2492 | continue; /* With next DNSBL domain */ | |
2493 | } | |
2494 | } | |
2495 | ||
2496 | /* Either there was no IP list, or the record matched. Look up a TXT record | |
2497 | if it hasn't previously been done. */ | |
2498 | ||
2499 | if (!cb->text_set) | |
2500 | { | |
2501 | cb->text_set = TRUE; | |
2502 | if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED) | |
2503 | { | |
2504 | dns_record *rr; | |
2505 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
2506 | rr != NULL; | |
2507 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2508 | if (rr->type == T_TXT) break; | |
2509 | if (rr != NULL) | |
2510 | { | |
2511 | int len = (rr->data)[0]; | |
2512 | if (len > 511) len = 127; | |
2513 | store_pool = POOL_PERM; | |
2514 | cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1)); | |
2515 | store_pool = old_pool; | |
2516 | } | |
2517 | } | |
2518 | } | |
2519 | ||
2520 | HDEBUG(D_dnsbl) | |
2521 | { | |
2522 | debug_printf("=> that means %s is listed at %s\n", | |
2523 | (key == NULL)? sender_host_address : key, domain); | |
2524 | } | |
2525 | ||
2526 | dnslist_domain = string_copy(domain); | |
2527 | dnslist_value = addlist; | |
2528 | dnslist_text = cb->text; | |
2529 | return OK; | |
2530 | } | |
2531 | ||
2532 | /* There was a problem with the DNS lookup */ | |
2533 | ||
2534 | if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA) | |
2535 | { | |
2536 | log_write(L_dnslist_defer, LOG_MAIN, | |
2537 | "DNS list lookup defer (probably timeout) for %s: %s", query, | |
2538 | (defer_return == OK)? US"assumed in list" : | |
2539 | (defer_return == FAIL)? US"assumed not in list" : | |
2540 | US"returned DEFER"); | |
2541 | return defer_return; | |
2542 | } | |
2543 | ||
2544 | /* No entry was found in the DNS; continue for next domain */ | |
2545 | ||
2546 | HDEBUG(D_dnsbl) | |
2547 | { | |
2548 | debug_printf("DNS lookup for %s failed\n", query); | |
2549 | debug_printf("=> that means %s is not listed at %s\n", | |
2550 | (key == NULL)? sender_host_address : key, domain); | |
2551 | } | |
2552 | } /* Continue with next domain */ | |
2553 | ||
2554 | return FAIL; | |
2555 | } | |
2556 | ||
2557 | /* End of verify.c */ |