Commit | Line | Data |
---|---|---|
8e669ac1 | 1 | /* $Cambridge: exim/src/src/host.c,v 1.9 2005/02/17 11:58:26 ph10 Exp $ */ |
059ec3d9 PH |
2 | |
3 | /************************************************* | |
4 | * Exim - an Internet mail transport agent * | |
5 | *************************************************/ | |
6 | ||
c988f1f4 | 7 | /* Copyright (c) University of Cambridge 1995 - 2005 */ |
059ec3d9 PH |
8 | /* See the file NOTICE for conditions of use and distribution. */ |
9 | ||
10 | /* Functions for finding hosts, either by gethostbyname(), gethostbyaddr(), or | |
11 | directly via the DNS. When IPv6 is supported, getipnodebyname() and | |
12 | getipnodebyaddr() may be used instead of gethostbyname() and gethostbyaddr(), | |
13 | if the newer functions are available. This module also contains various other | |
14 | functions concerned with hosts and addresses, and a random number function, | |
15 | used for randomizing hosts with equal MXs but available for use in other parts | |
16 | of Exim. */ | |
17 | ||
18 | ||
19 | #include "exim.h" | |
20 | ||
21 | ||
22 | /* Static variable for preserving the list of interface addresses in case it is | |
23 | used more than once. */ | |
24 | ||
25 | static ip_address_item *local_interface_data = NULL; | |
26 | ||
27 | ||
28 | #ifdef USE_INET_NTOA_FIX | |
29 | /************************************************* | |
30 | * Replacement for broken inet_ntoa() * | |
31 | *************************************************/ | |
32 | ||
33 | /* On IRIX systems, gcc uses a different structure passing convention to the | |
34 | native libraries. This causes inet_ntoa() to always yield 0.0.0.0 or | |
35 | 255.255.255.255. To get round this, we provide a private version of the | |
36 | function here. It is used only if USE_INET_NTOA_FIX is set, which should happen | |
37 | only when gcc is in use on an IRIX system. Code send to me by J.T. Breitner, | |
38 | with these comments: | |
39 | ||
40 | code by Stuart Levy | |
41 | as seen in comp.sys.sgi.admin | |
42 | ||
43 | Arguments: sa an in_addr structure | |
44 | Returns: pointer to static text string | |
45 | */ | |
46 | ||
47 | char * | |
48 | inet_ntoa(struct in_addr sa) | |
49 | { | |
50 | static uschar addr[20]; | |
51 | sprintf(addr, "%d.%d.%d.%d", | |
52 | (US &sa.s_addr)[0], | |
53 | (US &sa.s_addr)[1], | |
54 | (US &sa.s_addr)[2], | |
55 | (US &sa.s_addr)[3]); | |
56 | return addr; | |
57 | } | |
58 | #endif | |
59 | ||
60 | ||
61 | ||
62 | /************************************************* | |
63 | * Random number generator * | |
64 | *************************************************/ | |
65 | ||
66 | /* This is a simple pseudo-random number generator. It does not have to be | |
67 | very good for the uses to which it is put. When running the regression tests, | |
68 | start with a fixed seed. | |
69 | ||
70 | Arguments: | |
71 | limit: one more than the largest number required | |
72 | ||
73 | Returns: a pseudo-random number in the range 0 to limit-1 | |
74 | */ | |
75 | ||
76 | int | |
77 | random_number(int limit) | |
78 | { | |
79 | if (random_seed == 0) | |
80 | { | |
81 | if (running_in_test_harness) random_seed = 42; else | |
82 | { | |
83 | int p = (int)getpid(); | |
84 | random_seed = (int)time(NULL) ^ ((p << 16) | p); | |
85 | } | |
86 | } | |
87 | random_seed = 1103515245 * random_seed + 12345; | |
88 | return (unsigned int)(random_seed >> 16) % limit; | |
89 | } | |
90 | ||
91 | ||
92 | ||
d8ef3577 PH |
93 | /************************************************* |
94 | * Sort addresses when testing * | |
95 | *************************************************/ | |
96 | ||
97 | /* This function is called only when running in the test harness. It sorts a | |
98 | number of multihomed host IP addresses into the order, so as to get | |
99 | repeatability. This doesn't have to be efficient. But don't interchange IPv4 | |
100 | and IPv6 addresses! | |
101 | ||
102 | Arguments: | |
103 | host -> the first host item | |
104 | last -> the last host item | |
8e669ac1 | 105 | |
d8ef3577 | 106 | Returns: nothing |
8e669ac1 | 107 | */ |
d8ef3577 PH |
108 | |
109 | static void | |
110 | sort_addresses(host_item *host, host_item *last) | |
111 | { | |
112 | BOOL done = FALSE; | |
113 | while (!done) | |
114 | { | |
115 | host_item *h; | |
116 | done = TRUE; | |
117 | for (h = host; h != last; h = h->next) | |
118 | { | |
119 | if ((Ustrchr(h->address, ':') == NULL) != | |
120 | (Ustrchr(h->next->address, ':') == NULL)) | |
121 | continue; | |
122 | if (Ustrcmp(h->address, h->next->address) > 0) | |
123 | { | |
124 | uschar *temp = h->address; | |
125 | h->address = h->next->address; | |
126 | h->next->address = temp; | |
127 | done = FALSE; | |
128 | } | |
129 | } | |
130 | } | |
131 | } | |
132 | ||
133 | ||
134 | ||
059ec3d9 PH |
135 | /************************************************* |
136 | * Build chain of host items from list * | |
137 | *************************************************/ | |
138 | ||
139 | /* This function builds a chain of host items from a textual list of host | |
140 | names. It does not do any lookups. If randomize is true, the chain is build in | |
141 | a randomized order. There may be multiple groups of independently randomized | |
142 | hosts; they are delimited by a host name consisting of just "+". | |
143 | ||
144 | Arguments: | |
145 | anchor anchor for the chain | |
146 | list text list | |
147 | randomize TRUE for randomizing | |
148 | ||
149 | Returns: nothing | |
150 | */ | |
151 | ||
152 | void | |
153 | host_build_hostlist(host_item **anchor, uschar *list, BOOL randomize) | |
154 | { | |
155 | int sep = 0; | |
156 | int fake_mx = MX_NONE; /* This value is actually -1 */ | |
157 | uschar *name; | |
158 | uschar buffer[1024]; | |
159 | ||
160 | if (list == NULL) return; | |
161 | if (randomize) fake_mx--; /* Start at -2 for randomizing */ | |
162 | ||
163 | *anchor = NULL; | |
164 | ||
165 | while ((name = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) | |
166 | { | |
167 | host_item *h; | |
168 | ||
169 | if (name[0] == '+' && name[1] == 0) /* "+" delimits a randomized group */ | |
170 | { /* ignore if not randomizing */ | |
171 | if (randomize) fake_mx--; | |
172 | continue; | |
173 | } | |
174 | ||
175 | h = store_get(sizeof(host_item)); | |
176 | h->name = string_copy(name); | |
177 | h->address = NULL; | |
178 | h->port = PORT_NONE; | |
179 | h->mx = fake_mx; | |
180 | h->sort_key = randomize? (-fake_mx)*1000 + random_number(1000) : 0; | |
181 | h->status = hstatus_unknown; | |
182 | h->why = hwhy_unknown; | |
183 | h->last_try = 0; | |
184 | ||
185 | if (*anchor == NULL) | |
186 | { | |
187 | h->next = NULL; | |
188 | *anchor = h; | |
189 | } | |
190 | else | |
191 | { | |
192 | host_item *hh = *anchor; | |
193 | if (h->sort_key < hh->sort_key) | |
194 | { | |
195 | h->next = hh; | |
196 | *anchor = h; | |
197 | } | |
198 | else | |
199 | { | |
200 | while (hh->next != NULL && h->sort_key >= (hh->next)->sort_key) | |
201 | hh = hh->next; | |
202 | h->next = hh->next; | |
203 | hh->next = h; | |
204 | } | |
205 | } | |
206 | } | |
207 | } | |
208 | ||
209 | ||
210 | ||
211 | ||
212 | ||
213 | /************************************************* | |
214 | * Extract port from address string * | |
215 | *************************************************/ | |
216 | ||
217 | /* In the spool file, and in the -oMa and -oMi options, a host plus port is | |
218 | given as an IP address followed by a dot and a port number. This function | |
219 | decodes this. | |
220 | ||
221 | An alternative format for the -oMa and -oMi options is [ip address]:port which | |
222 | is what Exim 4 uses for output, because it seems to becoming commonly used, | |
223 | whereas the dot form confuses some programs/people. So we recognize that form | |
224 | too. | |
225 | ||
226 | Argument: | |
227 | address points to the string; if there is a port, the '.' in the string | |
228 | is overwritten with zero to terminate the address; if the string | |
229 | is in the [xxx]:ppp format, the address is shifted left and the | |
230 | brackets are removed | |
231 | ||
232 | Returns: 0 if there is no port, else the port number. If there's a syntax | |
233 | error, leave the incoming address alone, and return 0. | |
234 | */ | |
235 | ||
236 | int | |
237 | host_extract_port(uschar *address) | |
238 | { | |
239 | int port = 0; | |
240 | uschar *endptr; | |
241 | ||
242 | /* Handle the "bracketed with colon on the end" format */ | |
243 | ||
244 | if (*address == '[') | |
245 | { | |
246 | uschar *rb = address + 1; | |
247 | while (*rb != 0 && *rb != ']') rb++; | |
248 | if (*rb++ == 0) return 0; /* Missing ]; leave invalid address */ | |
249 | if (*rb == ':') | |
250 | { | |
251 | port = Ustrtol(rb + 1, &endptr, 10); | |
252 | if (*endptr != 0) return 0; /* Invalid port; leave invalid address */ | |
253 | } | |
254 | else if (*rb != 0) return 0; /* Bad syntax; leave invalid address */ | |
255 | memmove(address, address + 1, rb - address - 2); | |
256 | rb[-2] = 0; | |
257 | } | |
258 | ||
259 | /* Handle the "dot on the end" format */ | |
260 | ||
261 | else | |
262 | { | |
263 | int skip = -3; /* Skip 3 dots in IPv4 addresses */ | |
264 | address--; | |
265 | while (*(++address) != 0) | |
266 | { | |
267 | int ch = *address; | |
268 | if (ch == ':') skip = 0; /* Skip 0 dots in IPv6 addresses */ | |
269 | else if (ch == '.' && skip++ >= 0) break; | |
270 | } | |
271 | if (*address == 0) return 0; | |
272 | port = Ustrtol(address + 1, &endptr, 10); | |
273 | if (*endptr != 0) return 0; /* Invalid port; leave invalid address */ | |
274 | *address = 0; | |
275 | } | |
276 | ||
277 | return port; | |
278 | } | |
279 | ||
280 | ||
281 | ||
282 | #ifndef STAND_ALONE /* Omit when standalone testing */ | |
283 | ||
284 | /************************************************* | |
285 | * Build sender_fullhost and sender_rcvhost * | |
286 | *************************************************/ | |
287 | ||
288 | /* This function is called when sender_host_name and/or sender_helo_name | |
289 | have been set. Or might have been set - for a local message read off the spool | |
290 | they won't be. In that case, do nothing. Otherwise, set up the fullhost string | |
291 | as follows: | |
292 | ||
293 | (a) No sender_host_name or sender_helo_name: "[ip address]" | |
294 | (b) Just sender_host_name: "host_name [ip address]" | |
295 | (c) Just sender_helo_name: "(helo_name) [ip address]" | |
296 | (d) The two are identical: "host_name [ip address]" | |
297 | (e) The two are different: "host_name (helo_name) [ip address]" | |
298 | ||
299 | If log_incoming_port is set, the sending host's port number is added to the IP | |
300 | address. | |
301 | ||
302 | This function also builds sender_rcvhost for use in Received: lines, whose | |
303 | syntax is a bit different. This value also includes the RFC 1413 identity. | |
304 | There wouldn't be two different variables if I had got all this right in the | |
305 | first place. | |
306 | ||
307 | Because this data may survive over more than one incoming SMTP message, it has | |
308 | to be in permanent store. | |
309 | ||
310 | Arguments: none | |
311 | Returns: nothing | |
312 | */ | |
313 | ||
314 | void | |
315 | host_build_sender_fullhost(void) | |
316 | { | |
317 | uschar *address; | |
318 | int old_pool = store_pool; | |
319 | ||
320 | if (sender_host_address == NULL) return; | |
321 | ||
322 | store_pool = POOL_PERM; | |
323 | ||
324 | /* Set up address, with or without the port. After discussion, it seems that | |
325 | the only format that doesn't cause trouble is [aaaa]:pppp. However, we can't | |
326 | use this directly as the first item for Received: because it ain't an RFC 2822 | |
327 | domain. Sigh. */ | |
328 | ||
329 | address = string_sprintf("[%s]:%d", sender_host_address, sender_host_port); | |
330 | if ((log_extra_selector & LX_incoming_port) == 0 || sender_host_port <= 0) | |
331 | *(Ustrrchr(address, ':')) = 0; | |
332 | ||
333 | /* Host name is not verified */ | |
334 | ||
335 | if (sender_host_name == NULL) | |
336 | { | |
337 | uschar *portptr = Ustrstr(address, "]:"); | |
338 | int size = 0; | |
339 | int ptr = 0; | |
340 | int adlen; /* Sun compiler doesn't like ++ in initializers */ | |
341 | ||
342 | adlen = (portptr == NULL)? Ustrlen(address) : (++portptr - address); | |
343 | sender_fullhost = (sender_helo_name == NULL)? address : | |
344 | string_sprintf("(%s) %s", sender_helo_name, address); | |
345 | ||
346 | sender_rcvhost = string_cat(NULL, &size, &ptr, address, adlen); | |
347 | ||
348 | if (sender_ident != NULL || sender_helo_name != NULL || portptr != NULL) | |
349 | { | |
350 | int firstptr; | |
351 | sender_rcvhost = string_cat(sender_rcvhost, &size, &ptr, US" (", 2); | |
352 | firstptr = ptr; | |
353 | ||
354 | if (portptr != NULL) | |
355 | sender_rcvhost = string_append(sender_rcvhost, &size, &ptr, 2, US"port=", | |
356 | portptr + 1); | |
357 | ||
358 | if (sender_helo_name != NULL) | |
359 | sender_rcvhost = string_append(sender_rcvhost, &size, &ptr, 2, | |
360 | (firstptr == ptr)? US"helo=" : US" helo=", sender_helo_name); | |
361 | ||
362 | if (sender_ident != NULL) | |
363 | sender_rcvhost = string_append(sender_rcvhost, &size, &ptr, 2, | |
364 | (firstptr == ptr)? US"ident=" : US" ident=", sender_ident); | |
365 | ||
366 | sender_rcvhost = string_cat(sender_rcvhost, &size, &ptr, US")", 1); | |
367 | } | |
368 | ||
369 | sender_rcvhost[ptr] = 0; /* string_cat() always leaves room */ | |
370 | ||
371 | /* Release store, because string_cat allocated a minimum of 100 bytes that | |
372 | are rarely completely used. */ | |
373 | ||
374 | store_reset(sender_rcvhost + ptr + 1); | |
375 | } | |
376 | ||
377 | /* Host name is known and verified. */ | |
378 | ||
379 | else | |
380 | { | |
381 | int len; | |
382 | if (sender_helo_name == NULL || | |
383 | strcmpic(sender_host_name, sender_helo_name) == 0 || | |
384 | (sender_helo_name[0] == '[' && | |
385 | sender_helo_name[(len=Ustrlen(sender_helo_name))-1] == ']' && | |
386 | strncmpic(sender_helo_name+1, sender_host_address, len - 2) == 0)) | |
387 | { | |
388 | sender_fullhost = string_sprintf("%s %s", sender_host_name, address); | |
389 | sender_rcvhost = (sender_ident == NULL)? | |
390 | string_sprintf("%s (%s)", sender_host_name, address) : | |
391 | string_sprintf("%s (%s ident=%s)", sender_host_name, address, | |
392 | sender_ident); | |
393 | } | |
394 | else | |
395 | { | |
396 | sender_fullhost = string_sprintf("%s (%s) %s", sender_host_name, | |
397 | sender_helo_name, address); | |
398 | sender_rcvhost = (sender_ident == NULL)? | |
399 | string_sprintf("%s (%s helo=%s)", sender_host_name, | |
400 | address, sender_helo_name) : | |
401 | string_sprintf("%s\n\t(%s helo=%s ident=%s)", sender_host_name, | |
402 | address, sender_helo_name, sender_ident); | |
403 | } | |
404 | } | |
405 | ||
406 | store_pool = old_pool; | |
407 | ||
408 | DEBUG(D_host_lookup) debug_printf("sender_fullhost = %s\n", sender_fullhost); | |
409 | DEBUG(D_host_lookup) debug_printf("sender_rcvhost = %s\n", sender_rcvhost); | |
410 | } | |
411 | ||
412 | ||
413 | ||
414 | /************************************************* | |
415 | * Build host+ident message * | |
416 | *************************************************/ | |
417 | ||
418 | /* Used when logging rejections and various ACL and SMTP incidents. The text | |
419 | return depends on whether sender_fullhost and sender_ident are set or not: | |
420 | ||
421 | no ident, no host => U=unknown | |
422 | no ident, host set => H=sender_fullhost | |
423 | ident set, no host => U=ident | |
424 | ident set, host set => H=sender_fullhost U=ident | |
425 | ||
426 | Arguments: | |
427 | useflag TRUE if first item to be flagged (H= or U=); if there are two | |
428 | items, the second is always flagged | |
429 | ||
430 | Returns: pointer to a string in big_buffer | |
431 | */ | |
432 | ||
433 | uschar * | |
434 | host_and_ident(BOOL useflag) | |
435 | { | |
436 | if (sender_fullhost == NULL) | |
437 | { | |
438 | (void)string_format(big_buffer, big_buffer_size, "%s%s", useflag? "U=" : "", | |
439 | (sender_ident == NULL)? US"unknown" : sender_ident); | |
440 | } | |
441 | else | |
442 | { | |
443 | uschar *flag = useflag? US"H=" : US""; | |
444 | uschar *iface = US""; | |
445 | if ((log_extra_selector & LX_incoming_interface) != 0 && | |
446 | interface_address != NULL) | |
447 | iface = string_sprintf(" I=[%s]:%d", interface_address, interface_port); | |
448 | if (sender_ident == NULL) | |
449 | (void)string_format(big_buffer, big_buffer_size, "%s%s%s", | |
450 | flag, sender_fullhost, iface); | |
451 | else | |
452 | (void)string_format(big_buffer, big_buffer_size, "%s%s%s U=%s", | |
453 | flag, sender_fullhost, iface, sender_ident); | |
454 | } | |
455 | return big_buffer; | |
456 | } | |
457 | ||
458 | #endif /* STAND_ALONE */ | |
459 | ||
460 | ||
461 | ||
462 | ||
463 | /************************************************* | |
464 | * Build list of local interfaces * | |
465 | *************************************************/ | |
466 | ||
467 | /* This function interprets the contents of the local_interfaces or | |
468 | extra_local_interfaces options, and creates an ip_address_item block for each | |
469 | item on the list. There is no special interpretation of any IP addresses; in | |
470 | particular, 0.0.0.0 and ::0 are returned without modification. If any address | |
471 | includes a port, it is set in the block. Otherwise the port value is set to | |
472 | zero. | |
473 | ||
474 | Arguments: | |
475 | list the list | |
476 | name the name of the option being expanded | |
477 | ||
478 | Returns: a chain of ip_address_items, each containing to a textual | |
479 | version of an IP address, and a port number (host order) or | |
480 | zero if no port was given with the address | |
481 | */ | |
482 | ||
483 | ip_address_item * | |
484 | host_build_ifacelist(uschar *list, uschar *name) | |
485 | { | |
486 | int sep = 0; | |
487 | uschar *s; | |
488 | uschar buffer[64]; | |
489 | ip_address_item *yield = NULL; | |
490 | ip_address_item *last = NULL; | |
491 | ip_address_item *next; | |
492 | ||
493 | while ((s = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) | |
494 | { | |
495 | int port = host_extract_port(s); /* Leaves just the IP address */ | |
a5a28604 | 496 | if (string_is_ip_address(s, NULL) == 0) |
059ec3d9 PH |
497 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Malformed IP address \"%s\" in %s", |
498 | s, name); | |
499 | ||
500 | /* This use of strcpy() is OK because we have checked that s is a valid IP | |
501 | address above. The field in the ip_address_item is large enough to hold an | |
502 | IPv6 address. */ | |
503 | ||
504 | next = store_get(sizeof(ip_address_item)); | |
505 | next->next = NULL; | |
506 | Ustrcpy(next->address, s); | |
507 | next->port = port; | |
508 | next->v6_include_v4 = FALSE; | |
509 | ||
510 | if (yield == NULL) yield = last = next; else | |
511 | { | |
512 | last->next = next; | |
513 | last = next; | |
514 | } | |
515 | } | |
516 | ||
517 | return yield; | |
518 | } | |
519 | ||
520 | ||
521 | ||
522 | ||
523 | ||
524 | /************************************************* | |
525 | * Find addresses on local interfaces * | |
526 | *************************************************/ | |
527 | ||
528 | /* This function finds the addresses of local IP interfaces. These are used | |
529 | when testing for routing to the local host. As the function may be called more | |
530 | than once, the list is preserved in permanent store, pointed to by a static | |
531 | variable, to save doing the work more than once per process. | |
532 | ||
533 | The generic list of interfaces is obtained by calling host_build_ifacelist() | |
534 | for local_interfaces and extra_local_interfaces. This list scanned to remove | |
535 | duplicates (which may exist with different ports - not relevant here). If | |
536 | either of the wildcard IP addresses (0.0.0.0 and ::0) are encountered, they are | |
537 | replaced by the appropriate (IPv4 or IPv6) list of actual local interfaces, | |
538 | obtained from os_find_running_interfaces(). | |
539 | ||
540 | Arguments: none | |
541 | Returns: a chain of ip_address_items, each containing to a textual | |
542 | version of an IP address; the port numbers are not relevant | |
543 | */ | |
544 | ||
545 | ||
546 | /* First, a local subfunction to add an interface to a list in permanent store, | |
547 | but only if there isn't a previous copy of that address on the list. */ | |
548 | ||
549 | static ip_address_item * | |
550 | add_unique_interface(ip_address_item *list, ip_address_item *ipa) | |
551 | { | |
552 | ip_address_item *ipa2; | |
553 | for (ipa2 = list; ipa2 != NULL; ipa2 = ipa2->next) | |
554 | if (Ustrcmp(ipa2->address, ipa->address) == 0) return list; | |
555 | ipa2 = store_get_perm(sizeof(ip_address_item)); | |
556 | *ipa2 = *ipa; | |
557 | ipa2->next = list; | |
558 | return ipa2; | |
559 | } | |
560 | ||
561 | ||
562 | /* This is the globally visible function */ | |
563 | ||
564 | ip_address_item * | |
565 | host_find_interfaces(void) | |
566 | { | |
567 | ip_address_item *running_interfaces = NULL; | |
568 | ||
569 | if (local_interface_data == NULL) | |
570 | { | |
571 | void *reset_item = store_get(0); | |
572 | ip_address_item *dlist = host_build_ifacelist(local_interfaces, | |
573 | US"local_interfaces"); | |
574 | ip_address_item *xlist = host_build_ifacelist(extra_local_interfaces, | |
575 | US"extra_local_interfaces"); | |
576 | ip_address_item *ipa; | |
577 | ||
578 | if (dlist == NULL) dlist = xlist; else | |
579 | { | |
580 | for (ipa = dlist; ipa->next != NULL; ipa = ipa->next); | |
581 | ipa->next = xlist; | |
582 | } | |
583 | ||
584 | for (ipa = dlist; ipa != NULL; ipa = ipa->next) | |
585 | { | |
586 | if (Ustrcmp(ipa->address, "0.0.0.0") == 0 || | |
587 | Ustrcmp(ipa->address, "::0") == 0) | |
588 | { | |
589 | ip_address_item *ipa2; | |
590 | BOOL ipv6 = ipa->address[0] == ':'; | |
591 | if (running_interfaces == NULL) | |
592 | running_interfaces = os_find_running_interfaces(); | |
593 | for (ipa2 = running_interfaces; ipa2 != NULL; ipa2 = ipa2->next) | |
594 | { | |
595 | if ((Ustrchr(ipa2->address, ':') != NULL) == ipv6) | |
596 | local_interface_data = add_unique_interface(local_interface_data, | |
597 | ipa2); | |
598 | } | |
599 | } | |
600 | else | |
601 | { | |
602 | local_interface_data = add_unique_interface(local_interface_data, ipa); | |
603 | DEBUG(D_interface) | |
604 | { | |
605 | debug_printf("Configured local interface: address=%s", ipa->address); | |
606 | if (ipa->port != 0) debug_printf(" port=%d", ipa->port); | |
607 | debug_printf("\n"); | |
608 | } | |
609 | } | |
610 | } | |
611 | store_reset(reset_item); | |
612 | } | |
613 | ||
614 | return local_interface_data; | |
615 | } | |
616 | ||
617 | ||
618 | ||
619 | ||
620 | ||
621 | /************************************************* | |
622 | * Convert network IP address to text * | |
623 | *************************************************/ | |
624 | ||
625 | /* Given an IPv4 or IPv6 address in binary, convert it to a text | |
626 | string and return the result in a piece of new store. The address can | |
627 | either be given directly, or passed over in a sockaddr structure. Note | |
628 | that this isn't the converse of host_aton() because of byte ordering | |
629 | differences. See host_nmtoa() below. | |
630 | ||
631 | Arguments: | |
632 | type if < 0 then arg points to a sockaddr, else | |
633 | either AF_INET or AF_INET6 | |
634 | arg points to a sockaddr if type is < 0, or | |
635 | points to an IPv4 address (32 bits), or | |
636 | points to an IPv6 address (128 bits), | |
637 | in both cases, in network byte order | |
638 | buffer if NULL, the result is returned in gotten store; | |
639 | else points to a buffer to hold the answer | |
640 | portptr points to where to put the port number, if non NULL; only | |
641 | used when type < 0 | |
642 | ||
643 | Returns: pointer to character string | |
644 | */ | |
645 | ||
646 | uschar * | |
647 | host_ntoa(int type, const void *arg, uschar *buffer, int *portptr) | |
648 | { | |
649 | uschar *yield; | |
650 | ||
651 | /* The new world. It is annoying that we have to fish out the address from | |
652 | different places in the block, depending on what kind of address it is. It | |
653 | is also a pain that inet_ntop() returns a const uschar *, whereas the IPv4 | |
654 | function inet_ntoa() returns just uschar *, and some picky compilers insist | |
655 | on warning if one assigns a const uschar * to a uschar *. Hence the casts. */ | |
656 | ||
657 | #if HAVE_IPV6 | |
658 | uschar addr_buffer[46]; | |
659 | if (type < 0) | |
660 | { | |
661 | int family = ((struct sockaddr *)arg)->sa_family; | |
662 | if (family == AF_INET6) | |
663 | { | |
664 | struct sockaddr_in6 *sk = (struct sockaddr_in6 *)arg; | |
665 | yield = (uschar *)inet_ntop(family, &(sk->sin6_addr), CS addr_buffer, | |
666 | sizeof(addr_buffer)); | |
667 | if (portptr != NULL) *portptr = ntohs(sk->sin6_port); | |
668 | } | |
669 | else | |
670 | { | |
671 | struct sockaddr_in *sk = (struct sockaddr_in *)arg; | |
672 | yield = (uschar *)inet_ntop(family, &(sk->sin_addr), CS addr_buffer, | |
673 | sizeof(addr_buffer)); | |
674 | if (portptr != NULL) *portptr = ntohs(sk->sin_port); | |
675 | } | |
676 | } | |
677 | else | |
678 | { | |
679 | yield = (uschar *)inet_ntop(type, arg, CS addr_buffer, sizeof(addr_buffer)); | |
680 | } | |
681 | ||
682 | /* If the result is a mapped IPv4 address, show it in V4 format. */ | |
683 | ||
684 | if (Ustrncmp(yield, "::ffff:", 7) == 0) yield += 7; | |
685 | ||
686 | #else /* HAVE_IPV6 */ | |
687 | ||
688 | /* The old world */ | |
689 | ||
690 | if (type < 0) | |
691 | { | |
692 | yield = US inet_ntoa(((struct sockaddr_in *)arg)->sin_addr); | |
693 | if (portptr != NULL) *portptr = ntohs(((struct sockaddr_in *)arg)->sin_port); | |
694 | } | |
695 | else | |
696 | yield = US inet_ntoa(*((struct in_addr *)arg)); | |
697 | #endif | |
698 | ||
699 | /* If there is no buffer, put the string into some new store. */ | |
700 | ||
701 | if (buffer == NULL) return string_copy(yield); | |
702 | ||
703 | /* Callers of this function with a non-NULL buffer must ensure that it is | |
704 | large enough to hold an IPv6 address, namely, at least 46 bytes. That's what | |
705 | makes this use of strcpy() OK. */ | |
706 | ||
707 | Ustrcpy(buffer, yield); | |
708 | return buffer; | |
709 | } | |
710 | ||
711 | ||
712 | ||
713 | ||
714 | /************************************************* | |
715 | * Convert address text to binary * | |
716 | *************************************************/ | |
717 | ||
718 | /* Given the textual form of an IP address, convert it to binary in an | |
719 | array of ints. IPv4 addresses occupy one int; IPv6 addresses occupy 4 ints. | |
720 | The result has the first byte in the most significant byte of the first int. In | |
721 | other words, the result is not in network byte order, but in host byte order. | |
722 | As a result, this is not the converse of host_ntoa(), which expects network | |
723 | byte order. See host_nmtoa() below. | |
724 | ||
725 | Arguments: | |
726 | address points to the textual address, checked for syntax | |
727 | bin points to an array of 4 ints | |
728 | ||
729 | Returns: the number of ints used | |
730 | */ | |
731 | ||
732 | int | |
733 | host_aton(uschar *address, int *bin) | |
734 | { | |
735 | int x[4]; | |
736 | int v4offset = 0; | |
737 | ||
8e669ac1 | 738 | /* Handle IPv6 address, which may end with an IPv4 address. It may also end |
7e634d24 PH |
739 | with a "scope", introduced by a percent sign. This code is NOT enclosed in #if |
740 | HAVE_IPV6 in order that IPv6 addresses are recognized even if IPv6 is not | |
741 | supported. */ | |
059ec3d9 PH |
742 | |
743 | if (Ustrchr(address, ':') != NULL) | |
744 | { | |
745 | uschar *p = address; | |
746 | uschar *component[8]; | |
747 | BOOL ipv4_ends = FALSE; | |
748 | int ci = 0; | |
749 | int nulloffset = 0; | |
750 | int v6count = 8; | |
751 | int i; | |
752 | ||
753 | /* If the address starts with a colon, it will start with two colons. | |
754 | Just lose the first one, which will leave a null first component. */ | |
8e669ac1 | 755 | |
059ec3d9 PH |
756 | if (*p == ':') p++; |
757 | ||
8e669ac1 PH |
758 | /* Split the address into components separated by colons. The input address |
759 | is supposed to be checked for syntax. There was a case where this was | |
760 | overlooked; to guard against that happening again, check here and crash if | |
7e634d24 | 761 | there are too many components. */ |
059ec3d9 | 762 | |
7e634d24 | 763 | while (*p != 0 && *p != '%') |
059ec3d9 | 764 | { |
7e634d24 | 765 | int len = Ustrcspn(p, ":%"); |
059ec3d9 | 766 | if (len == 0) nulloffset = ci; |
8e669ac1 | 767 | if (ci > 7) log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
b975ba52 | 768 | "Internal error: invalid IPv6 address \"%s\" passed to host_aton()", |
8e669ac1 | 769 | address); |
059ec3d9 PH |
770 | component[ci++] = p; |
771 | p += len; | |
772 | if (*p == ':') p++; | |
773 | } | |
774 | ||
775 | /* If the final component contains a dot, it is a trailing v4 address. | |
776 | As the syntax is known to be checked, just set up for a trailing | |
777 | v4 address and restrict the v6 part to 6 components. */ | |
778 | ||
779 | if (Ustrchr(component[ci-1], '.') != NULL) | |
780 | { | |
781 | address = component[--ci]; | |
782 | ipv4_ends = TRUE; | |
783 | v4offset = 3; | |
784 | v6count = 6; | |
785 | } | |
786 | ||
787 | /* If there are fewer than 6 or 8 components, we have to insert some | |
788 | more empty ones in the middle. */ | |
789 | ||
790 | if (ci < v6count) | |
791 | { | |
792 | int insert_count = v6count - ci; | |
793 | for (i = v6count-1; i > nulloffset + insert_count; i--) | |
794 | component[i] = component[i - insert_count]; | |
795 | while (i > nulloffset) component[i--] = US""; | |
796 | } | |
797 | ||
798 | /* Now turn the components into binary in pairs and bung them | |
799 | into the vector of ints. */ | |
800 | ||
801 | for (i = 0; i < v6count; i += 2) | |
802 | bin[i/2] = (Ustrtol(component[i], NULL, 16) << 16) + | |
803 | Ustrtol(component[i+1], NULL, 16); | |
804 | ||
805 | /* If there was no terminating v4 component, we are done. */ | |
806 | ||
807 | if (!ipv4_ends) return 4; | |
808 | } | |
809 | ||
810 | /* Handle IPv4 address */ | |
811 | ||
812 | sscanf(CS address, "%d.%d.%d.%d", x, x+1, x+2, x+3); | |
813 | bin[v4offset] = (x[0] << 24) + (x[1] << 16) + (x[2] << 8) + x[3]; | |
814 | return v4offset+1; | |
815 | } | |
816 | ||
817 | ||
818 | /************************************************* | |
819 | * Apply mask to an IP address * | |
820 | *************************************************/ | |
821 | ||
822 | /* Mask an address held in 1 or 4 ints, with the ms bit in the ms bit of the | |
823 | first int, etc. | |
824 | ||
825 | Arguments: | |
826 | count the number of ints | |
827 | binary points to the ints to be masked | |
828 | mask the count of ms bits to leave, or -1 if no masking | |
829 | ||
830 | Returns: nothing | |
831 | */ | |
832 | ||
833 | void | |
834 | host_mask(int count, int *binary, int mask) | |
835 | { | |
836 | int i; | |
837 | if (mask < 0) mask = 99999; | |
838 | for (i = 0; i < count; i++) | |
839 | { | |
840 | int wordmask; | |
841 | if (mask == 0) wordmask = 0; | |
842 | else if (mask < 32) | |
843 | { | |
844 | wordmask = (-1) << (32 - mask); | |
845 | mask = 0; | |
846 | } | |
847 | else | |
848 | { | |
849 | wordmask = -1; | |
850 | mask -= 32; | |
851 | } | |
852 | binary[i] &= wordmask; | |
853 | } | |
854 | } | |
855 | ||
856 | ||
857 | ||
858 | ||
859 | /************************************************* | |
860 | * Convert masked IP address in ints to text * | |
861 | *************************************************/ | |
862 | ||
863 | /* We can't use host_ntoa() because it assumes the binary values are in network | |
864 | byte order, and these are the result of host_aton(), which puts them in ints in | |
865 | host byte order. Also, we really want IPv6 addresses to be in a canonical | |
6f0c9a4f PH |
866 | format, so we output them with no abbreviation. In a number of cases we can't |
867 | use the normal colon separator in them because it terminates keys in lsearch | |
8e669ac1 | 868 | files, so we want to use dot instead. There's an argument that specifies what |
6f0c9a4f | 869 | to use for IPv6 addresses. |
059ec3d9 PH |
870 | |
871 | Arguments: | |
872 | count 1 or 4 (number of ints) | |
873 | binary points to the ints | |
874 | mask mask value; if < 0 don't add to result | |
875 | buffer big enough to hold the result | |
8e669ac1 | 876 | sep component separator character for IPv6 addresses |
059ec3d9 PH |
877 | |
878 | Returns: the number of characters placed in buffer, not counting | |
879 | the final nul. | |
880 | */ | |
881 | ||
882 | int | |
6f0c9a4f | 883 | host_nmtoa(int count, int *binary, int mask, uschar *buffer, int sep) |
059ec3d9 PH |
884 | { |
885 | int i, j; | |
886 | uschar *tt = buffer; | |
887 | ||
888 | if (count == 1) | |
889 | { | |
890 | j = binary[0]; | |
891 | for (i = 24; i >= 0; i -= 8) | |
892 | { | |
893 | sprintf(CS tt, "%d.", (j >> i) & 255); | |
894 | while (*tt) tt++; | |
895 | } | |
896 | } | |
897 | else | |
898 | { | |
899 | for (i = 0; i < 4; i++) | |
900 | { | |
901 | j = binary[i]; | |
6f0c9a4f | 902 | sprintf(CS tt, "%04x%c%04x%c", (j >> 16) & 0xffff, sep, j & 0xffff, sep); |
059ec3d9 PH |
903 | while (*tt) tt++; |
904 | } | |
905 | } | |
906 | ||
6f0c9a4f | 907 | tt--; /* lose final separator */ |
059ec3d9 PH |
908 | |
909 | if (mask < 0) | |
910 | *tt = 0; | |
911 | else | |
912 | { | |
913 | sprintf(CS tt, "/%d", mask); | |
914 | while (*tt) tt++; | |
915 | } | |
916 | ||
917 | return tt - buffer; | |
918 | } | |
919 | ||
920 | ||
921 | ||
922 | /************************************************* | |
923 | * Check port for tls_on_connect * | |
924 | *************************************************/ | |
925 | ||
926 | /* This function checks whether a given incoming port is configured for tls- | |
927 | on-connect. It is called from the daemon and from inetd handling. If the global | |
928 | option tls_on_connect is already set, all ports operate this way. Otherwise, we | |
929 | check the tls_on_connect_ports option for a list of ports. | |
930 | ||
931 | Argument: a port number | |
932 | Returns: TRUE or FALSE | |
933 | */ | |
934 | ||
935 | BOOL | |
936 | host_is_tls_on_connect_port(int port) | |
937 | { | |
938 | int sep = 0; | |
939 | uschar buffer[32]; | |
940 | uschar *list = tls_on_connect_ports; | |
941 | uschar *s; | |
942 | ||
943 | if (tls_on_connect) return TRUE; | |
944 | ||
945 | while ((s = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) | |
946 | { | |
947 | uschar *end; | |
948 | int lport = Ustrtol(s, &end, 10); | |
949 | if (*end != 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "tls_on_connect_ports " | |
950 | "contains \"%s\", which is not a port number: exim abandoned", s); | |
951 | if (lport == port) return TRUE; | |
952 | } | |
953 | ||
954 | return FALSE; | |
955 | } | |
956 | ||
957 | ||
958 | ||
959 | /************************************************* | |
960 | * Check whether host is in a network * | |
961 | *************************************************/ | |
962 | ||
963 | /* This function checks whether a given IP address matches a pattern that | |
964 | represents either a single host, or a network (using CIDR notation). The caller | |
965 | of this function must check the syntax of the arguments before calling it. | |
966 | ||
967 | Arguments: | |
968 | host string representation of the ip-address to check | |
969 | net string representation of the network, with optional CIDR mask | |
970 | maskoffset offset to the / that introduces the mask in the key | |
971 | zero if there is no mask | |
972 | ||
973 | Returns: | |
974 | TRUE the host is inside the network | |
975 | FALSE the host is NOT inside the network | |
976 | */ | |
977 | ||
978 | BOOL | |
979 | host_is_in_net(uschar *host, uschar *net, int maskoffset) | |
980 | { | |
981 | int i; | |
982 | int address[4]; | |
983 | int incoming[4]; | |
984 | int mlen; | |
985 | int size = host_aton(net, address); | |
986 | int insize; | |
987 | ||
988 | /* No mask => all bits to be checked */ | |
989 | ||
990 | if (maskoffset == 0) mlen = 99999; /* Big number */ | |
991 | else mlen = Uatoi(net + maskoffset + 1); | |
992 | ||
993 | /* Convert the incoming address to binary. */ | |
994 | ||
995 | insize = host_aton(host, incoming); | |
996 | ||
997 | /* Convert IPv4 addresses given in IPv6 compatible mode, which represent | |
998 | connections from IPv4 hosts to IPv6 hosts, that is, addresses of the form | |
999 | ::ffff:<v4address>, to IPv4 format. */ | |
1000 | ||
1001 | if (insize == 4 && incoming[0] == 0 && incoming[1] == 0 && | |
1002 | incoming[2] == 0xffff) | |
1003 | { | |
1004 | insize = 1; | |
1005 | incoming[0] = incoming[3]; | |
1006 | } | |
1007 | ||
1008 | /* No match if the sizes don't agree. */ | |
1009 | ||
1010 | if (insize != size) return FALSE; | |
1011 | ||
1012 | /* Else do the masked comparison. */ | |
1013 | ||
1014 | for (i = 0; i < size; i++) | |
1015 | { | |
1016 | int mask; | |
1017 | if (mlen == 0) mask = 0; | |
1018 | else if (mlen < 32) | |
1019 | { | |
1020 | mask = (-1) << (32 - mlen); | |
1021 | mlen = 0; | |
1022 | } | |
1023 | else | |
1024 | { | |
1025 | mask = -1; | |
1026 | mlen -= 32; | |
1027 | } | |
1028 | if ((incoming[i] & mask) != (address[i] & mask)) return FALSE; | |
1029 | } | |
1030 | ||
1031 | return TRUE; | |
1032 | } | |
1033 | ||
1034 | ||
1035 | ||
1036 | /************************************************* | |
1037 | * Scan host list for local hosts * | |
1038 | *************************************************/ | |
1039 | ||
1040 | /* Scan through a chain of addresses and check whether any of them is the | |
1041 | address of an interface on the local machine. If so, remove that address and | |
1042 | any previous ones with the same MX value, and all subsequent ones (which will | |
1043 | have greater or equal MX values) from the chain. Note: marking them as unusable | |
1044 | is NOT the right thing to do because it causes the hosts not to be used for | |
1045 | other domains, for which they may well be correct. | |
1046 | ||
1047 | The hosts may be part of a longer chain; we only process those between the | |
1048 | initial pointer and the "last" pointer. | |
1049 | ||
1050 | There is also a list of "pseudo-local" host names which are checked against the | |
1051 | host names. Any match causes that host item to be treated the same as one which | |
1052 | matches a local IP address. | |
1053 | ||
1054 | If the very first host is a local host, then all MX records had a precedence | |
1055 | greater than or equal to that of the local host. Either there's a problem in | |
1056 | the DNS, or an apparently remote name turned out to be an abbreviation for the | |
1057 | local host. Give a specific return code, and let the caller decide what to do. | |
1058 | Otherwise, give a success code if at least one host address has been found. | |
1059 | ||
1060 | Arguments: | |
1061 | host pointer to the first host in the chain | |
1062 | lastptr pointer to pointer to the last host in the chain (may be updated) | |
1063 | removed if not NULL, set TRUE if some local addresses were removed | |
1064 | from the list | |
1065 | ||
1066 | Returns: | |
1067 | HOST_FOUND if there is at least one host with an IP address on the chain | |
1068 | and an MX value less than any MX value associated with the | |
1069 | local host | |
1070 | HOST_FOUND_LOCAL if a local host is among the lowest-numbered MX hosts; when | |
1071 | the host addresses were obtained from A records or | |
1072 | gethostbyname(), the MX values are set to -1. | |
1073 | HOST_FIND_FAILED if no valid hosts with set IP addresses were found | |
1074 | */ | |
1075 | ||
1076 | int | |
1077 | host_scan_for_local_hosts(host_item *host, host_item **lastptr, BOOL *removed) | |
1078 | { | |
1079 | int yield = HOST_FIND_FAILED; | |
1080 | host_item *last = *lastptr; | |
1081 | host_item *prev = NULL; | |
1082 | host_item *h; | |
1083 | ||
1084 | if (removed != NULL) *removed = FALSE; | |
1085 | ||
1086 | if (local_interface_data == NULL) local_interface_data = host_find_interfaces(); | |
1087 | ||
1088 | for (h = host; h != last->next; h = h->next) | |
1089 | { | |
1090 | #ifndef STAND_ALONE | |
1091 | if (hosts_treat_as_local != NULL) | |
1092 | { | |
1093 | int rc; | |
1094 | uschar *save = deliver_domain; | |
1095 | deliver_domain = h->name; /* set $domain */ | |
1096 | rc = match_isinlist(string_copylc(h->name), &hosts_treat_as_local, 0, | |
1097 | &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL); | |
1098 | deliver_domain = save; | |
1099 | if (rc == OK) goto FOUND_LOCAL; | |
1100 | } | |
1101 | #endif | |
1102 | ||
1103 | /* It seems that on many operating systems, 0.0.0.0 is treated as a synonym | |
1104 | for 127.0.0.1 and refers to the local host. We therefore force it always to | |
1105 | be treated as local. */ | |
1106 | ||
1107 | if (h->address != NULL) | |
1108 | { | |
1109 | ip_address_item *ip; | |
1110 | if (Ustrcmp(h->address, "0.0.0.0") == 0) goto FOUND_LOCAL; | |
1111 | for (ip = local_interface_data; ip != NULL; ip = ip->next) | |
1112 | if (Ustrcmp(h->address, ip->address) == 0) goto FOUND_LOCAL; | |
1113 | yield = HOST_FOUND; /* At least one remote address has been found */ | |
1114 | } | |
1115 | ||
1116 | /* Update prev to point to the last host item before any that have | |
1117 | the same MX value as the one we have just considered. */ | |
1118 | ||
1119 | if (h->next == NULL || h->next->mx != h->mx) prev = h; | |
1120 | } | |
1121 | ||
1122 | return yield; /* No local hosts found: return HOST_FOUND or HOST_FIND_FAILED */ | |
1123 | ||
1124 | /* A host whose IP address matches a local IP address, or whose name matches | |
1125 | something in hosts_treat_as_local has been found. */ | |
1126 | ||
1127 | FOUND_LOCAL: | |
1128 | ||
1129 | if (prev == NULL) | |
1130 | { | |
1131 | HDEBUG(D_host_lookup) debug_printf((h->mx >= 0)? | |
1132 | "local host has lowest MX\n" : | |
1133 | "local host found for non-MX address\n"); | |
1134 | return HOST_FOUND_LOCAL; | |
1135 | } | |
1136 | ||
1137 | HDEBUG(D_host_lookup) | |
1138 | { | |
1139 | debug_printf("local host in host list - removed hosts:\n"); | |
1140 | for (h = prev->next; h != last->next; h = h->next) | |
1141 | debug_printf(" %s %s %d\n", h->name, h->address, h->mx); | |
1142 | } | |
1143 | ||
1144 | if (removed != NULL) *removed = TRUE; | |
1145 | prev->next = last->next; | |
1146 | *lastptr = prev; | |
1147 | return yield; | |
1148 | } | |
1149 | ||
1150 | ||
1151 | ||
1152 | ||
1153 | /************************************************* | |
1154 | * Remove duplicate IPs in host list * | |
1155 | *************************************************/ | |
1156 | ||
1157 | /* You would think that administrators could set up their DNS records so that | |
1158 | one ended up with a list of unique IP addresses after looking up A or MX | |
1159 | records, but apparently duplication is common. So we scan such lists and | |
1160 | remove the later duplicates. Note that we may get lists in which some host | |
1161 | addresses are not set. | |
1162 | ||
1163 | Arguments: | |
1164 | host pointer to the first host in the chain | |
1165 | lastptr pointer to pointer to the last host in the chain (may be updated) | |
1166 | ||
1167 | Returns: nothing | |
1168 | */ | |
1169 | ||
1170 | static void | |
1171 | host_remove_duplicates(host_item *host, host_item **lastptr) | |
1172 | { | |
1173 | while (host != *lastptr) | |
1174 | { | |
1175 | if (host->address != NULL) | |
1176 | { | |
1177 | host_item *h = host; | |
1178 | while (h != *lastptr) | |
1179 | { | |
1180 | if (h->next->address != NULL && | |
1181 | Ustrcmp(h->next->address, host->address) == 0) | |
1182 | { | |
1183 | DEBUG(D_host_lookup) debug_printf("duplicate IP address %s (MX=%d) " | |
1184 | "removed\n", host->address, h->next->mx); | |
1185 | if (h->next == *lastptr) *lastptr = h; | |
1186 | h->next = h->next->next; | |
1187 | } | |
1188 | else h = h->next; | |
1189 | } | |
1190 | } | |
1191 | /* If the last item was removed, host may have become == *lastptr */ | |
1192 | if (host != *lastptr) host = host->next; | |
1193 | } | |
1194 | } | |
1195 | ||
1196 | ||
1197 | ||
1198 | ||
1199 | /************************************************* | |
1200 | * Find sender host name by gethostbyaddr() * | |
1201 | *************************************************/ | |
1202 | ||
1203 | /* This used to be the only way it was done, but it turns out that not all | |
1204 | systems give aliases for calls to gethostbyaddr() - or one of the modern | |
1205 | equivalents like getipnodebyaddr(). Fortunately, multiple PTR records are rare, | |
1206 | but they can still exist. This function is now used only when a DNS lookup of | |
1207 | the IP address fails, in order to give access to /etc/hosts. | |
1208 | ||
1209 | Arguments: none | |
1210 | Returns: OK, DEFER, FAIL | |
1211 | */ | |
1212 | ||
1213 | static int | |
1214 | host_name_lookup_byaddr(void) | |
1215 | { | |
1216 | int len; | |
1217 | uschar *s, *t; | |
1218 | struct hostent *hosts; | |
1219 | struct in_addr addr; | |
1220 | ||
1221 | /* Lookup on IPv6 system */ | |
1222 | ||
1223 | #if HAVE_IPV6 | |
1224 | if (Ustrchr(sender_host_address, ':') != NULL) | |
1225 | { | |
1226 | struct in6_addr addr6; | |
1227 | if (inet_pton(AF_INET6, CS sender_host_address, &addr6) != 1) | |
1228 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an " | |
1229 | "IPv6 address", sender_host_address); | |
1230 | #if HAVE_GETIPNODEBYADDR | |
1231 | hosts = getipnodebyaddr(CS &addr6, sizeof(addr6), AF_INET6, &h_errno); | |
1232 | #else | |
1233 | hosts = gethostbyaddr(CS &addr6, sizeof(addr6), AF_INET6); | |
1234 | #endif | |
1235 | } | |
1236 | else | |
1237 | { | |
1238 | if (inet_pton(AF_INET, CS sender_host_address, &addr) != 1) | |
1239 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an " | |
1240 | "IPv4 address", sender_host_address); | |
1241 | #if HAVE_GETIPNODEBYADDR | |
1242 | hosts = getipnodebyaddr(CS &addr, sizeof(addr), AF_INET, &h_errno); | |
1243 | #else | |
1244 | hosts = gethostbyaddr(CS &addr, sizeof(addr), AF_INET); | |
1245 | #endif | |
1246 | } | |
1247 | ||
1248 | /* Do lookup on IPv4 system */ | |
1249 | ||
1250 | #else | |
1251 | addr.s_addr = (S_ADDR_TYPE)inet_addr(CS sender_host_address); | |
1252 | hosts = gethostbyaddr(CS(&addr), sizeof(addr), AF_INET); | |
1253 | #endif | |
1254 | ||
1255 | /* Failed to look up the host. */ | |
1256 | ||
1257 | if (hosts == NULL) | |
1258 | { | |
1259 | HDEBUG(D_host_lookup) debug_printf("IP address lookup failed: h_errno=%d\n", | |
1260 | h_errno); | |
1261 | return (h_errno == TRY_AGAIN || h_errno == NO_RECOVERY) ? DEFER : FAIL; | |
1262 | } | |
1263 | ||
1264 | /* It seems there are some records in the DNS that yield an empty name. We | |
1265 | treat this as non-existent. In some operating systems, this is returned as an | |
1266 | empty string; in others as a single dot. */ | |
1267 | ||
1268 | if (hosts->h_name[0] == 0 || hosts->h_name[0] == '.') | |
1269 | { | |
1270 | HDEBUG(D_host_lookup) debug_printf("IP address lookup yielded an empty name: " | |
1271 | "treated as non-existent host name\n"); | |
1272 | return FAIL; | |
1273 | } | |
1274 | ||
1275 | /* Copy and lowercase the name, which is in static storage in many systems. | |
1276 | Put it in permanent memory. */ | |
1277 | ||
1278 | s = (uschar *)hosts->h_name; | |
1279 | len = Ustrlen(s) + 1; | |
1280 | t = sender_host_name = store_get_perm(len); | |
1281 | while (*s != 0) *t++ = tolower(*s++); | |
1282 | *t = 0; | |
1283 | ||
1284 | /* If the host has aliases, build a copy of the alias list */ | |
1285 | ||
1286 | if (hosts->h_aliases != NULL) | |
1287 | { | |
1288 | int count = 1; | |
1289 | uschar **aliases, **ptr; | |
1290 | for (aliases = USS hosts->h_aliases; *aliases != NULL; aliases++) count++; | |
1291 | ptr = sender_host_aliases = store_get_perm(count * sizeof(uschar *)); | |
1292 | for (aliases = USS hosts->h_aliases; *aliases != NULL; aliases++) | |
1293 | { | |
1294 | uschar *s = *aliases; | |
1295 | int len = Ustrlen(s) + 1; | |
1296 | uschar *t = *ptr++ = store_get_perm(len); | |
1297 | while (*s != 0) *t++ = tolower(*s++); | |
1298 | *t = 0; | |
1299 | } | |
1300 | *ptr = NULL; | |
1301 | } | |
1302 | ||
1303 | return OK; | |
1304 | } | |
1305 | ||
1306 | ||
1307 | ||
1308 | /************************************************* | |
1309 | * Find host name for incoming call * | |
1310 | *************************************************/ | |
1311 | ||
1312 | /* Put the name in permanent store, pointed to by sender_host_name. We also set | |
1313 | up a list of alias names, pointed to by sender_host_alias. The list is | |
1314 | NULL-terminated. The incoming address is in sender_host_address, either in | |
1315 | dotted-quad form for IPv4 or in colon-separated form for IPv6. | |
1316 | ||
1317 | This function does a thorough check that the names it finds point back to the | |
1318 | incoming IP address. Any that do not are discarded. Note that this is relied on | |
1319 | by the ACL reverse_host_lookup check. | |
1320 | ||
1321 | On some systems, get{host,ipnode}byaddr() appears to do this internally, but | |
1322 | this it not universally true. Also, for release 4.30, this function was changed | |
1323 | to do a direct DNS lookup first, by default[1], because it turns out that that | |
1324 | is the only guaranteed way to find all the aliases on some systems. My | |
1325 | experiments indicate that Solaris gethostbyaddr() gives the aliases for but | |
1326 | Linux does not. | |
1327 | ||
1328 | [1] The actual order is controlled by the host_lookup_order option. | |
1329 | ||
1330 | Arguments: none | |
1331 | Returns: OK on success, the answer being placed in the global variable | |
1332 | sender_host_name, with any aliases in a list hung off | |
1333 | sender_host_aliases | |
1334 | FAIL if no host name can be found | |
1335 | DEFER if a temporary error was encountered | |
1336 | ||
1337 | The variable host_lookup_msg is set to an empty string on sucess, or to a | |
1338 | reason for the failure otherwise, in a form suitable for tagging onto an error | |
8e669ac1 | 1339 | message, and also host_lookup_failed is set TRUE if the lookup failed. If there |
b08b24c8 PH |
1340 | was a defer, host_lookup_deferred is set TRUE. |
1341 | ||
1342 | Any dynamically constructed string for host_lookup_msg must be in permanent | |
1343 | store, because it might be used for several incoming messages on the same SMTP | |
059ec3d9 PH |
1344 | connection. */ |
1345 | ||
1346 | int | |
1347 | host_name_lookup(void) | |
1348 | { | |
1349 | int old_pool, rc; | |
1350 | int sep = 0; | |
1351 | uschar *hname, *save_hostname; | |
1352 | uschar **aliases; | |
1353 | uschar buffer[256]; | |
1354 | uschar *ordername; | |
1355 | uschar *list = host_lookup_order; | |
1356 | dns_record *rr; | |
1357 | dns_answer dnsa; | |
1358 | dns_scan dnss; | |
1359 | ||
b08b24c8 PH |
1360 | host_lookup_deferred = host_lookup_failed = FALSE; |
1361 | ||
059ec3d9 PH |
1362 | HDEBUG(D_host_lookup) |
1363 | debug_printf("looking up host name for %s\n", sender_host_address); | |
1364 | ||
1365 | /* For testing the case when a lookup does not complete, we have a special | |
1366 | reserved IP address. */ | |
1367 | ||
1368 | if (running_in_test_harness && | |
1369 | Ustrcmp(sender_host_address, "99.99.99.99") == 0) | |
1370 | { | |
1371 | HDEBUG(D_host_lookup) | |
1372 | debug_printf("Test harness: host name lookup returns DEFER\n"); | |
8e669ac1 | 1373 | host_lookup_deferred = TRUE; |
059ec3d9 PH |
1374 | return DEFER; |
1375 | } | |
1376 | ||
1377 | /* Do lookups directly in the DNS or via gethostbyaddr() (or equivalent), in | |
1378 | the order specified by the host_lookup_order option. */ | |
1379 | ||
1380 | while ((ordername = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) | |
1381 | != NULL) | |
1382 | { | |
1383 | if (strcmpic(ordername, US"bydns") == 0) | |
1384 | { | |
1385 | dns_init(FALSE, FALSE); | |
1386 | dns_build_reverse(sender_host_address, buffer); | |
1387 | rc = dns_lookup(&dnsa, buffer, T_PTR, NULL); | |
1388 | ||
1389 | /* The first record we come across is used for the name; others are | |
1390 | considered to be aliases. We have to scan twice, in order to find out the | |
1391 | number of aliases. However, if all the names are empty, we will behave as | |
1392 | if failure. (PTR records that yield empty names have been encountered in | |
1393 | the DNS.) */ | |
1394 | ||
1395 | if (rc == DNS_SUCCEED) | |
1396 | { | |
1397 | uschar **aptr = NULL; | |
1398 | int ssize = 264; | |
1399 | int count = 0; | |
1400 | int old_pool = store_pool; | |
1401 | ||
1402 | store_pool = POOL_PERM; /* Save names in permanent storage */ | |
1403 | ||
1404 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
1405 | rr != NULL; | |
1406 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
1407 | { | |
1408 | if (rr->type == T_PTR) count++; | |
1409 | } | |
1410 | ||
1411 | /* Get store for the list of aliases. For compatibility with | |
1412 | gethostbyaddr, we make an empty list if there are none. */ | |
1413 | ||
1414 | aptr = sender_host_aliases = store_get(count * sizeof(uschar *)); | |
1415 | ||
1416 | /* Re-scan and extract the names */ | |
1417 | ||
1418 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
1419 | rr != NULL; | |
1420 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
1421 | { | |
1422 | uschar *s = NULL; | |
1423 | if (rr->type != T_PTR) continue; | |
1424 | s = store_get(ssize); | |
1425 | ||
1426 | /* If an overlong response was received, the data will have been | |
1427 | truncated and dn_expand may fail. */ | |
1428 | ||
1429 | if (dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, | |
1430 | (uschar *)(rr->data), (DN_EXPAND_ARG4_TYPE)(s), ssize) < 0) | |
1431 | { | |
1432 | log_write(0, LOG_MAIN, "host name alias list truncated for %s", | |
1433 | sender_host_address); | |
1434 | break; | |
1435 | } | |
1436 | ||
1437 | store_reset(s + Ustrlen(s) + 1); | |
1438 | if (s[0] == 0) | |
1439 | { | |
1440 | HDEBUG(D_host_lookup) debug_printf("IP address lookup yielded an " | |
1441 | "empty name: treated as non-existent host name\n"); | |
1442 | continue; | |
1443 | } | |
1444 | if (sender_host_name == NULL) sender_host_name = s; | |
1445 | else *aptr++ = s; | |
1446 | while (*s != 0) { *s = tolower(*s); s++; } | |
1447 | } | |
1448 | ||
1449 | *aptr = NULL; /* End of alias list */ | |
1450 | store_pool = old_pool; /* Reset store pool */ | |
1451 | ||
1452 | /* If we've found a names, break out of the "order" loop */ | |
1453 | ||
1454 | if (sender_host_name != NULL) break; | |
1455 | } | |
1456 | ||
1457 | /* If the DNS lookup deferred, we must also defer. */ | |
1458 | ||
1459 | if (rc == DNS_AGAIN) | |
1460 | { | |
1461 | HDEBUG(D_host_lookup) | |
1462 | debug_printf("IP address PTR lookup gave temporary error\n"); | |
8e669ac1 | 1463 | host_lookup_deferred = TRUE; |
059ec3d9 PH |
1464 | return DEFER; |
1465 | } | |
1466 | } | |
1467 | ||
1468 | /* Do a lookup using gethostbyaddr() - or equivalent */ | |
1469 | ||
1470 | else if (strcmpic(ordername, US"byaddr") == 0) | |
1471 | { | |
1472 | HDEBUG(D_host_lookup) | |
1473 | debug_printf("IP address lookup using gethostbyaddr()\n"); | |
059ec3d9 | 1474 | rc = host_name_lookup_byaddr(); |
8e669ac1 | 1475 | if (rc == DEFER) |
b08b24c8 | 1476 | { |
8e669ac1 | 1477 | host_lookup_deferred = TRUE; |
b08b24c8 | 1478 | return rc; /* Can't carry on */ |
8e669ac1 | 1479 | } |
059ec3d9 PH |
1480 | if (rc == OK) break; /* Found a name */ |
1481 | } | |
1482 | } /* Loop for bydns/byaddr scanning */ | |
1483 | ||
1484 | /* If we have failed to find a name, return FAIL and log when required. | |
1485 | NB host_lookup_msg must be in permanent store. */ | |
1486 | ||
1487 | if (sender_host_name == NULL) | |
1488 | { | |
1489 | if (host_checking || !log_testing_mode) | |
1490 | log_write(L_host_lookup_failed, LOG_MAIN, "no host name found for IP " | |
1491 | "address %s", sender_host_address); | |
1492 | host_lookup_msg = US" (failed to find host name from IP address)"; | |
b08b24c8 | 1493 | host_lookup_failed = TRUE; |
059ec3d9 PH |
1494 | return FAIL; |
1495 | } | |
1496 | ||
1497 | /* We have a host name. If we are running in the test harness, we want the host | |
1498 | name and its alias to appear always the same way round. There are only ever two | |
1499 | names in these tests. If one of them contains "alias", make sure it is second; | |
1500 | otherwise put them in alphabetical order. */ | |
1501 | ||
1502 | if (running_in_test_harness && *sender_host_aliases != NULL && | |
1503 | ( | |
1504 | Ustrstr(sender_host_name, "alias") != NULL || | |
1505 | ( | |
1506 | Ustrstr(*sender_host_aliases, "alias") == NULL && | |
1507 | Ustrcmp(sender_host_name, *sender_host_aliases) > 0 | |
1508 | ) | |
1509 | )) | |
1510 | { | |
1511 | uschar *temp = sender_host_name; | |
1512 | sender_host_name = *sender_host_aliases; | |
1513 | *sender_host_aliases = temp; | |
1514 | } | |
1515 | ||
1516 | /* Debug output what was found, after test harness swapping, for consistency */ | |
1517 | ||
1518 | HDEBUG(D_host_lookup) | |
1519 | { | |
1520 | uschar **aliases = sender_host_aliases; | |
1521 | debug_printf("IP address lookup yielded %s\n", sender_host_name); | |
1522 | while (*aliases != NULL) debug_printf(" alias %s\n", *aliases++); | |
1523 | } | |
1524 | ||
1525 | /* We need to verify that a forward lookup on the name we found does indeed | |
1526 | correspond to the address. This is for security: in principle a malefactor who | |
1527 | happened to own a reverse zone could set it to point to any names at all. | |
1528 | ||
1529 | This code was present in versions of Exim before 3.20. At that point I took it | |
1530 | out because I thought that gethostbyaddr() did the check anyway. It turns out | |
1531 | that this isn't always the case, so it's coming back in at 4.01. This version | |
1532 | is actually better, because it also checks aliases. | |
1533 | ||
1534 | The code was made more robust at release 4.21. Prior to that, it accepted all | |
1535 | the names if any of them had the correct IP address. Now the code checks all | |
1536 | the names, and accepts only those that have the correct IP address. */ | |
1537 | ||
1538 | save_hostname = sender_host_name; /* Save for error messages */ | |
1539 | aliases = sender_host_aliases; | |
1540 | for (hname = sender_host_name; hname != NULL; hname = *aliases++) | |
1541 | { | |
1542 | int rc; | |
1543 | BOOL ok = FALSE; | |
1544 | host_item h; | |
1545 | h.next = NULL; | |
1546 | h.name = hname; | |
1547 | h.mx = MX_NONE; | |
1548 | h.address = NULL; | |
1549 | ||
1550 | /* When called with the 5th argument FALSE, host_find_byname() won't return | |
1551 | HOST_FOUND_LOCAL. If the incoming address is an IPv4 address expressed in | |
1552 | IPv6 format, we must compare the IPv4 part to any IPv4 addresses. */ | |
1553 | ||
1554 | if ((rc = host_find_byname(&h, NULL, NULL, FALSE)) == HOST_FOUND) | |
1555 | { | |
1556 | host_item *hh; | |
1557 | uschar *address_ipv4 = (Ustrncmp(sender_host_address, "::ffff:", 7) == 0)? | |
1558 | sender_host_address + 7 : sender_host_address; | |
1559 | HDEBUG(D_host_lookup) debug_printf("checking addresses for %s\n", hname); | |
1560 | for (hh = &h; hh != NULL; hh = hh->next) | |
1561 | { | |
1562 | if ((Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)? | |
1563 | address_ipv4 : sender_host_address)) == 0) | |
1564 | { | |
1565 | HDEBUG(D_host_lookup) debug_printf(" %s OK\n", hh->address); | |
1566 | ok = TRUE; | |
1567 | break; | |
1568 | } | |
1569 | else | |
1570 | { | |
1571 | HDEBUG(D_host_lookup) debug_printf(" %s\n", hh->address); | |
1572 | } | |
1573 | } | |
1574 | if (!ok) HDEBUG(D_host_lookup) | |
1575 | debug_printf("no IP address for %s matched %s\n", hname, | |
1576 | sender_host_address); | |
1577 | } | |
1578 | else if (rc == HOST_FIND_AGAIN) | |
1579 | { | |
1580 | HDEBUG(D_host_lookup) debug_printf("temporary error for host name lookup\n"); | |
8e669ac1 | 1581 | host_lookup_deferred = TRUE; |
059ec3d9 PH |
1582 | return DEFER; |
1583 | } | |
1584 | else | |
1585 | { | |
1586 | HDEBUG(D_host_lookup) debug_printf("no IP addresses found for %s\n", hname); | |
1587 | } | |
1588 | ||
1589 | /* If this name is no good, and it's the sender name, set it null pro tem; | |
1590 | if it's an alias, just remove it from the list. */ | |
1591 | ||
1592 | if (!ok) | |
1593 | { | |
1594 | if (hname == sender_host_name) sender_host_name = NULL; else | |
1595 | { | |
1596 | uschar **a; /* Don't amalgamate - some */ | |
1597 | a = --aliases; /* compilers grumble */ | |
1598 | while (*a != NULL) { *a = a[1]; a++; } | |
1599 | } | |
1600 | } | |
1601 | } | |
1602 | ||
1603 | /* If sender_host_name == NULL, it means we didn't like the name. Replace | |
1604 | it with the first alias, if there is one. */ | |
1605 | ||
1606 | if (sender_host_name == NULL && *sender_host_aliases != NULL) | |
1607 | sender_host_name = *sender_host_aliases++; | |
1608 | ||
1609 | /* If we now have a main name, all is well. */ | |
1610 | ||
1611 | if (sender_host_name != NULL) return OK; | |
1612 | ||
1613 | /* We have failed to find an address that matches. */ | |
1614 | ||
1615 | HDEBUG(D_host_lookup) | |
1616 | debug_printf("%s does not match any IP address for %s\n", | |
1617 | sender_host_address, save_hostname); | |
1618 | ||
1619 | /* This message must be in permanent store */ | |
1620 | ||
1621 | old_pool = store_pool; | |
1622 | store_pool = POOL_PERM; | |
1623 | host_lookup_msg = string_sprintf(" (%s does not match any IP address for %s)", | |
1624 | sender_host_address, save_hostname); | |
1625 | store_pool = old_pool; | |
059ec3d9 PH |
1626 | host_lookup_failed = TRUE; |
1627 | return FAIL; | |
1628 | } | |
1629 | ||
1630 | ||
1631 | ||
1632 | ||
1633 | /************************************************* | |
1634 | * Find IP address(es) for host by name * | |
1635 | *************************************************/ | |
1636 | ||
1637 | /* The input is a host_item structure with the name filled in and the address | |
1638 | field set to NULL. We use gethostbyname(). Of course, gethostbyname() may use | |
1639 | the DNS, but it doesn't do MX processing. If more than one address is given, | |
1640 | chain on additional host items, with other relevant fields copied. | |
1641 | ||
1642 | The second argument provides a host list (usually an IP list) of hosts to | |
1643 | ignore. This makes it possible to ignore IPv6 link-local addresses or loopback | |
1644 | addresses in unreasonable places. | |
1645 | ||
1646 | The lookup may result in a change of name. For compatibility with the dns | |
1647 | lookup, return this via fully_qualified_name as well as updating the host item. | |
1648 | The lookup may also yield more than one IP address, in which case chain on | |
1649 | subsequent host_item structures. | |
1650 | ||
1651 | Arguments: | |
1652 | host a host item with the name and MX filled in; | |
1653 | the address is to be filled in; | |
1654 | multiple IP addresses cause other host items to be | |
1655 | chained on. | |
1656 | ignore_target_hosts a list of hosts to ignore | |
1657 | fully_qualified_name if not NULL, set to point to host name for | |
1658 | compatibility with host_find_bydns | |
1659 | local_host_check TRUE if a check for the local host is wanted | |
1660 | ||
1661 | Returns: HOST_FIND_FAILED Failed to find the host or domain | |
1662 | HOST_FIND_AGAIN Try again later | |
1663 | HOST_FOUND Host found - data filled in | |
1664 | HOST_FOUND_LOCAL Host found and is the local host | |
1665 | */ | |
1666 | ||
1667 | int | |
1668 | host_find_byname(host_item *host, uschar *ignore_target_hosts, | |
1669 | uschar **fully_qualified_name, BOOL local_host_check) | |
1670 | { | |
1671 | int i, yield, times; | |
1672 | uschar **addrlist; | |
1673 | host_item *last = NULL; | |
1674 | BOOL temp_error = FALSE; | |
b08b24c8 PH |
1675 | #if HAVE_IPV6 |
1676 | int af; | |
1677 | #endif | |
1678 | ||
1679 | /* If we are in the test harness, a name ending in .test.again.dns always | |
1680 | forces a temporary error response. */ | |
1681 | ||
1682 | if (running_in_test_harness) | |
1683 | { | |
1684 | uschar *endname = host->name + Ustrlen(host->name); | |
1685 | if (Ustrcmp(endname - 14, "test.again.dns") == 0) | |
1686 | return HOST_FIND_AGAIN; | |
8e669ac1 | 1687 | } |
059ec3d9 PH |
1688 | |
1689 | /* In an IPv6 world, we need to scan for both kinds of address, so go round the | |
1690 | loop twice. Note that we have ensured that AF_INET6 is defined even in an IPv4 | |
1691 | world, which makes for slightly tidier code. However, if dns_ipv4_lookup | |
1692 | matches the domain, we also just do IPv4 lookups here (except when testing | |
1693 | standalone). */ | |
1694 | ||
1695 | #if HAVE_IPV6 | |
059ec3d9 PH |
1696 | #ifndef STAND_ALONE |
1697 | if (dns_ipv4_lookup != NULL && | |
1698 | match_isinlist(host->name, &dns_ipv4_lookup, 0, NULL, NULL, MCL_DOMAIN, | |
1699 | TRUE, NULL) == OK) | |
1700 | { af = AF_INET; times = 1; } | |
1701 | else | |
1702 | #endif /* STAND_ALONE */ | |
1703 | ||
1704 | { af = AF_INET6; times = 2; } | |
1705 | ||
1706 | /* No IPv6 support */ | |
1707 | ||
1708 | #else /* HAVE_IPV6 */ | |
1709 | times = 1; | |
1710 | #endif /* HAVE_IPV6 */ | |
1711 | ||
1712 | /* Initialize the flag that gets set for DNS syntax check errors, so that the | |
1713 | interface to this function can be similar to host_find_bydns. */ | |
1714 | ||
1715 | host_find_failed_syntax = FALSE; | |
1716 | ||
1717 | /* Loop to look up both kinds of address in an IPv6 world */ | |
1718 | ||
1719 | for (i = 1; i <= times; | |
1720 | #if HAVE_IPV6 | |
1721 | af = AF_INET, /* If 2 passes, IPv4 on the second */ | |
1722 | #endif | |
1723 | i++) | |
1724 | { | |
1725 | BOOL ipv4_addr; | |
1726 | int error_num; | |
1727 | struct hostent *hostdata; | |
1728 | ||
1729 | #if HAVE_IPV6 | |
1730 | #if HAVE_GETIPNODEBYNAME | |
1731 | hostdata = getipnodebyname(CS host->name, af, 0, &error_num); | |
1732 | #else | |
1733 | hostdata = gethostbyname2(CS host->name, af); | |
1734 | error_num = h_errno; | |
1735 | #endif | |
1736 | #else | |
1737 | hostdata = gethostbyname(CS host->name); | |
1738 | error_num = h_errno; | |
1739 | #endif | |
1740 | ||
1741 | if (hostdata == NULL) | |
1742 | { | |
1743 | uschar *error; | |
1744 | switch (error_num) | |
1745 | { | |
1746 | case HOST_NOT_FOUND: error = US"HOST_NOT_FOUND"; break; | |
1747 | case TRY_AGAIN: error = US"TRY_AGAIN"; break; | |
1748 | case NO_RECOVERY: error = US"NO_RECOVERY"; break; | |
1749 | case NO_DATA: error = US"NO_DATA"; break; | |
1750 | #if NO_DATA != NO_ADDRESS | |
1751 | case NO_ADDRESS: error = US"NO_ADDRESS"; break; | |
1752 | #endif | |
1753 | default: error = US"?"; break; | |
1754 | } | |
1755 | ||
1756 | DEBUG(D_host_lookup) debug_printf("%s returned %d (%s)\n", | |
1757 | #if HAVE_IPV6 | |
1758 | #if HAVE_GETIPNODEBYNAME | |
1759 | (af == AF_INET6)? "getipnodebyname(af=inet6)" : "getipnodebyname(af=inet)", | |
1760 | #else | |
1761 | (af == AF_INET6)? "gethostbyname2(af=inet6)" : "gethostbyname2(af=inet)", | |
1762 | #endif | |
1763 | #else | |
1764 | "gethostbyname", | |
1765 | #endif | |
1766 | error_num, error); | |
1767 | ||
1768 | if (error_num == TRY_AGAIN || error_num == NO_RECOVERY) temp_error = TRUE; | |
1769 | continue; | |
1770 | } | |
1771 | if ((hostdata->h_addr_list)[0] == NULL) continue; | |
1772 | ||
1773 | /* Replace the name with the fully qualified one if necessary, and fill in | |
1774 | the fully_qualified_name pointer. */ | |
1775 | ||
1776 | if (hostdata->h_name[0] != 0 && | |
1777 | Ustrcmp(host->name, hostdata->h_name) != 0) | |
1778 | host->name = string_copy_dnsdomain((uschar *)hostdata->h_name); | |
1779 | if (fully_qualified_name != NULL) *fully_qualified_name = host->name; | |
1780 | ||
1781 | /* Get the list of addresses. IPv4 and IPv6 addresses can be distinguished | |
1782 | by their different lengths. Scan the list, ignoring any that are to be | |
1783 | ignored, and build a chain from the rest. */ | |
1784 | ||
1785 | ipv4_addr = hostdata->h_length == sizeof(struct in_addr); | |
1786 | ||
1787 | for (addrlist = USS hostdata->h_addr_list; *addrlist != NULL; addrlist++) | |
1788 | { | |
1789 | uschar *text_address = | |
1790 | host_ntoa(ipv4_addr? AF_INET:AF_INET6, *addrlist, NULL, NULL); | |
1791 | ||
1792 | #ifndef STAND_ALONE | |
1793 | if (ignore_target_hosts != NULL && | |
1794 | verify_check_this_host(&ignore_target_hosts, NULL, host->name, | |
1795 | text_address, NULL) == OK) | |
1796 | { | |
1797 | DEBUG(D_host_lookup) | |
1798 | debug_printf("ignored host %s [%s]\n", host->name, text_address); | |
1799 | continue; | |
1800 | } | |
1801 | #endif | |
1802 | ||
1803 | /* If this is the first address, last == NULL and we put the data in the | |
1804 | original block. */ | |
1805 | ||
1806 | if (last == NULL) | |
1807 | { | |
1808 | host->address = text_address; | |
1809 | host->port = PORT_NONE; | |
1810 | host->status = hstatus_unknown; | |
1811 | host->why = hwhy_unknown; | |
1812 | last = host; | |
1813 | } | |
1814 | ||
1815 | /* Else add further host item blocks for any other addresses, keeping | |
1816 | the order. */ | |
1817 | ||
1818 | else | |
1819 | { | |
1820 | host_item *next = store_get(sizeof(host_item)); | |
1821 | next->name = host->name; | |
1822 | next->mx = host->mx; | |
1823 | next->address = text_address; | |
1824 | next->port = PORT_NONE; | |
1825 | next->status = hstatus_unknown; | |
1826 | next->why = hwhy_unknown; | |
1827 | next->last_try = 0; | |
1828 | next->next = last->next; | |
1829 | last->next = next; | |
1830 | last = next; | |
1831 | } | |
1832 | } | |
1833 | } | |
1834 | ||
1835 | /* If no hosts were found, the address field in the original host block will be | |
1836 | NULL. If temp_error is set, at least one of the lookups gave a temporary error, | |
1837 | so we pass that back. */ | |
1838 | ||
1839 | if (host->address == NULL) | |
1840 | { | |
1841 | uschar *msg = | |
1842 | #ifndef STAND_ALONE | |
1843 | (message_id[0] == 0 && smtp_in != NULL)? | |
1844 | string_sprintf("no IP address found for host %s (during %s)", host->name, | |
1845 | smtp_get_connection_info()) : | |
1846 | #endif | |
1847 | string_sprintf("no IP address found for host %s", host->name); | |
1848 | ||
1849 | HDEBUG(D_host_lookup) debug_printf("%s\n", msg); | |
1850 | if (temp_error) return HOST_FIND_AGAIN; | |
1851 | if (host_checking || !log_testing_mode) | |
1852 | log_write(L_host_lookup_failed, LOG_MAIN, "%s", msg); | |
1853 | return HOST_FIND_FAILED; | |
1854 | } | |
1855 | ||
1856 | /* Remove any duplicate IP addresses, then check to see if this is the local | |
1857 | host if required. */ | |
1858 | ||
1859 | host_remove_duplicates(host, &last); | |
1860 | yield = local_host_check? | |
1861 | host_scan_for_local_hosts(host, &last, NULL) : HOST_FOUND; | |
1862 | ||
1863 | /* When running in the test harness, sort into the order of addresses so as to | |
d8ef3577 | 1864 | get repeatability. */ |
059ec3d9 | 1865 | |
d8ef3577 | 1866 | if (running_in_test_harness) sort_addresses(host, last); |
059ec3d9 PH |
1867 | |
1868 | HDEBUG(D_host_lookup) | |
1869 | { | |
1870 | host_item *h; | |
1871 | if (fully_qualified_name != NULL) | |
1872 | debug_printf("fully qualified name = %s\n", *fully_qualified_name); | |
1873 | debug_printf("%s looked up these IP addresses:\n", | |
1874 | #if HAVE_IPV6 | |
1875 | #if HAVE_GETIPNODEBYNAME | |
1876 | "getipnodebyname" | |
1877 | #else | |
1878 | "gethostbyname2" | |
1879 | #endif | |
1880 | #else | |
1881 | "gethostbyname" | |
1882 | #endif | |
1883 | ); | |
1884 | for (h = host; h != last->next; h = h->next) | |
1885 | debug_printf(" name=%s address=%s\n", h->name, | |
1886 | (h->address == NULL)? US"<null>" : h->address); | |
1887 | } | |
1888 | ||
1889 | /* Return the found status. */ | |
1890 | ||
1891 | return yield; | |
1892 | } | |
1893 | ||
1894 | ||
1895 | ||
1896 | /************************************************* | |
1897 | * Fill in a host address from the DNS * | |
1898 | *************************************************/ | |
1899 | ||
1900 | /* Given a host item, with its name and mx fields set, and its address field | |
1901 | set to NULL, fill in its IP address from the DNS. If it is multi-homed, create | |
1902 | additional host items for the additional addresses, copying all the other | |
1903 | fields, and randomizing the order. | |
1904 | ||
1905 | On IPv6 systems, A6 records are sought first (but only if support for A6 is | |
1906 | configured - they may never become mainstream), then AAAA records are sought, | |
1907 | and finally A records are sought as well. | |
1908 | ||
1909 | The host name may be changed if the DNS returns a different name - e.g. fully | |
1910 | qualified or changed via CNAME. If fully_qualified_name is not NULL, dns_lookup | |
1911 | ensures that it points to the fully qualified name. However, this is the fully | |
1912 | qualified version of the original name; if a CNAME is involved, the actual | |
1913 | canonical host name may be different again, and so we get it directly from the | |
1914 | relevant RR. Note that we do NOT change the mx field of the host item in this | |
1915 | function as it may be called to set the addresses of hosts taken from MX | |
1916 | records. | |
1917 | ||
1918 | Arguments: | |
1919 | host points to the host item we're filling in | |
1920 | lastptr points to pointer to last host item in a chain of | |
1921 | host items (may be updated if host is last and gets | |
1922 | extended because multihomed) | |
1923 | ignore_target_hosts list of hosts to ignore | |
1924 | allow_ip if TRUE, recognize an IP address and return it | |
1925 | fully_qualified_name if not NULL, return fully qualified name here if | |
1926 | the contents are different (i.e. it must be preset | |
1927 | to something) | |
1928 | ||
1929 | Returns: HOST_FIND_FAILED couldn't find A record | |
1930 | HOST_FIND_AGAIN try again later | |
1931 | HOST_FOUND found AAAA and/or A record(s) | |
1932 | HOST_IGNORED found, but all IPs ignored | |
1933 | */ | |
1934 | ||
1935 | static int | |
1936 | set_address_from_dns(host_item *host, host_item **lastptr, | |
1937 | uschar *ignore_target_hosts, BOOL allow_ip, uschar **fully_qualified_name) | |
1938 | { | |
1939 | dns_record *rr; | |
1940 | host_item *thishostlast = NULL; /* Indicates not yet filled in anything */ | |
1941 | BOOL v6_find_again = FALSE; | |
1942 | int i; | |
1943 | ||
1944 | /* If allow_ip is set, a name which is an IP address returns that value | |
1945 | as its address. This is used for MX records when allow_mx_to_ip is set, for | |
1946 | those sites that feel they have to flaunt the RFC rules. */ | |
1947 | ||
1948 | if (allow_ip && string_is_ip_address(host->name, NULL) != 0) | |
1949 | { | |
1950 | #ifndef STAND_ALONE | |
1951 | if (ignore_target_hosts != NULL && | |
1952 | verify_check_this_host(&ignore_target_hosts, NULL, host->name, | |
1953 | host->name, NULL) == OK) | |
1954 | return HOST_IGNORED; | |
1955 | #endif | |
1956 | ||
1957 | host->address = host->name; | |
1958 | host->port = PORT_NONE; | |
1959 | return HOST_FOUND; | |
1960 | } | |
1961 | ||
1962 | /* On an IPv6 system, go round the loop up to three times, looking for A6 and | |
1963 | AAAA records the first two times. However, unless doing standalone testing, we | |
1964 | force an IPv4 lookup if the domain matches dns_ipv4_lookup is set. Since A6 | |
1965 | records look like being abandoned, support them only if explicitly configured | |
1966 | to do so. On an IPv4 system, go round the loop once only, looking only for A | |
1967 | records. */ | |
1968 | ||
1969 | #if HAVE_IPV6 | |
1970 | ||
1971 | #ifndef STAND_ALONE | |
1972 | if (dns_ipv4_lookup != NULL && | |
1973 | match_isinlist(host->name, &dns_ipv4_lookup, 0, NULL, NULL, MCL_DOMAIN, | |
1974 | TRUE, NULL) == OK) | |
1975 | i = 0; /* look up A records only */ | |
1976 | else | |
1977 | #endif /* STAND_ALONE */ | |
1978 | ||
1979 | #ifdef SUPPORT_A6 | |
1980 | i = 2; /* look up A6 and AAAA and A records */ | |
1981 | #else | |
1982 | i = 1; /* look up AAAA and A records */ | |
1983 | #endif /* SUPPORT_A6 */ | |
1984 | ||
1985 | /* The IPv4 world */ | |
1986 | ||
1987 | #else /* HAVE_IPV6 */ | |
1988 | i = 0; /* look up A records only */ | |
1989 | #endif /* HAVE_IPV6 */ | |
1990 | ||
1991 | for (; i >= 0; i--) | |
1992 | { | |
1993 | static int types[] = { T_A, T_AAAA, T_A6 }; | |
1994 | int type = types[i]; | |
1995 | int randoffset = (i == 0)? 500 : 0; /* Ensures v6 sorts before v4 */ | |
1996 | dns_answer dnsa; | |
1997 | dns_scan dnss; | |
1998 | ||
1999 | int rc = dns_lookup(&dnsa, host->name, type, fully_qualified_name); | |
2000 | ||
2001 | /* We want to return HOST_FIND_AGAIN if one of the A, A6, or AAAA lookups | |
2002 | fails or times out, but not if another one succeeds. (In the early | |
2003 | IPv6 days there are name servers that always fail on AAAA, but are happy | |
2004 | to give out an A record. We want to proceed with that A record.) */ | |
8e669ac1 | 2005 | |
059ec3d9 PH |
2006 | if (rc != DNS_SUCCEED) |
2007 | { | |
2008 | if (i == 0) /* Just tried for an A record, i.e. end of loop */ | |
2009 | { | |
2010 | if (host->address != NULL) return HOST_FOUND; /* A6 or AAAA was found */ | |
2011 | if (rc == DNS_AGAIN || rc == DNS_FAIL || v6_find_again) | |
2012 | return HOST_FIND_AGAIN; | |
2013 | return HOST_FIND_FAILED; /* DNS_NOMATCH or DNS_NODATA */ | |
2014 | } | |
2015 | ||
2016 | /* Tried for an A6 or AAAA record: remember if this was a temporary | |
2017 | error, and look for the next record type. */ | |
2018 | ||
2019 | if (rc != DNS_NOMATCH && rc != DNS_NODATA) v6_find_again = TRUE; | |
2020 | continue; | |
2021 | } | |
2022 | ||
2023 | /* Lookup succeeded: fill in the given host item with the first non-ignored | |
2024 | address found; create additional items for any others. A single A6 record | |
2025 | may generate more than one address. */ | |
2026 | ||
2027 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
2028 | rr != NULL; | |
2029 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2030 | { | |
2031 | if (rr->type == type) | |
2032 | { | |
2033 | /* dns_address *da = dns_address_from_rr(&dnsa, rr); */ | |
2034 | ||
2035 | dns_address *da; | |
2036 | da = dns_address_from_rr(&dnsa, rr); | |
2037 | ||
2038 | DEBUG(D_host_lookup) | |
2039 | { | |
2040 | if (da == NULL) | |
2041 | debug_printf("no addresses extracted from A6 RR for %s\n", | |
2042 | host->name); | |
2043 | } | |
2044 | ||
2045 | /* This loop runs only once for A and AAAA records, but may run | |
2046 | several times for an A6 record that generated multiple addresses. */ | |
2047 | ||
2048 | for (; da != NULL; da = da->next) | |
2049 | { | |
2050 | #ifndef STAND_ALONE | |
2051 | if (ignore_target_hosts != NULL && | |
2052 | verify_check_this_host(&ignore_target_hosts, NULL, | |
2053 | host->name, da->address, NULL) == OK) | |
2054 | { | |
2055 | DEBUG(D_host_lookup) | |
2056 | debug_printf("ignored host %s [%s]\n", host->name, da->address); | |
2057 | continue; | |
2058 | } | |
2059 | #endif | |
2060 | ||
2061 | /* If this is the first address, stick it in the given host block, | |
2062 | and change the name if the returned RR has a different name. */ | |
2063 | ||
2064 | if (thishostlast == NULL) | |
2065 | { | |
2066 | if (strcmpic(host->name, rr->name) != 0) | |
2067 | host->name = string_copy_dnsdomain(rr->name); | |
2068 | host->address = da->address; | |
2069 | host->port = PORT_NONE; | |
2070 | host->sort_key = host->mx * 1000 + random_number(500) + randoffset; | |
2071 | host->status = hstatus_unknown; | |
2072 | host->why = hwhy_unknown; | |
2073 | thishostlast = host; | |
2074 | } | |
2075 | ||
2076 | /* Not the first address. Check for, and ignore, duplicates. Then | |
2077 | insert in the chain at a random point. */ | |
2078 | ||
2079 | else | |
2080 | { | |
2081 | int new_sort_key; | |
2082 | host_item *next; | |
2083 | ||
2084 | /* End of our local chain is specified by "thishostlast". */ | |
2085 | ||
2086 | for (next = host;; next = next->next) | |
2087 | { | |
2088 | if (Ustrcmp(CS da->address, next->address) == 0) break; | |
2089 | if (next == thishostlast) { next = NULL; break; } | |
2090 | } | |
2091 | if (next != NULL) continue; /* With loop for next address */ | |
2092 | ||
2093 | /* Not a duplicate */ | |
2094 | ||
2095 | new_sort_key = host->mx * 1000 + random_number(500) + randoffset; | |
2096 | next = store_get(sizeof(host_item)); | |
2097 | ||
2098 | /* New address goes first: insert the new block after the first one | |
2099 | (so as not to disturb the original pointer) but put the new address | |
2100 | in the original block. */ | |
2101 | ||
2102 | if (new_sort_key < host->sort_key) | |
2103 | { | |
2104 | *next = *host; | |
2105 | host->next = next; | |
2106 | host->address = da->address; | |
2107 | host->port = PORT_NONE; | |
2108 | host->sort_key = new_sort_key; | |
2109 | if (thishostlast == host) thishostlast = next; /* Local last */ | |
2110 | if (*lastptr == host) *lastptr = next; /* Global last */ | |
2111 | } | |
2112 | ||
2113 | /* Otherwise scan down the addresses for this host to find the | |
2114 | one to insert after. */ | |
2115 | ||
2116 | else | |
2117 | { | |
2118 | host_item *h = host; | |
2119 | while (h != thishostlast) | |
2120 | { | |
2121 | if (new_sort_key < h->next->sort_key) break; | |
2122 | h = h->next; | |
2123 | } | |
2124 | *next = *h; | |
2125 | h->next = next; | |
2126 | next->address = da->address; | |
2127 | next->port = PORT_NONE; | |
2128 | next->sort_key = new_sort_key; | |
2129 | if (h == thishostlast) thishostlast = next; /* Local last */ | |
2130 | if (h == *lastptr) *lastptr = next; /* Global last */ | |
2131 | } | |
2132 | } | |
2133 | } | |
2134 | } | |
2135 | } | |
2136 | } | |
2137 | ||
2138 | /* Control gets here only if the third lookup (the A record) succeeded. | |
2139 | However, the address may not be filled in if it was ignored. */ | |
2140 | ||
2141 | return (host->address == NULL)? HOST_IGNORED : HOST_FOUND; | |
2142 | } | |
2143 | ||
2144 | ||
2145 | ||
2146 | ||
2147 | /************************************************* | |
2148 | * Find IP addresses and names for host via DNS * | |
2149 | *************************************************/ | |
2150 | ||
2151 | /* The input is a host_item structure with the name filled in and the address | |
2152 | field set to NULL. This may be in a chain of other host items. The lookup may | |
2153 | result in more than one IP address, in which case we must created new host | |
2154 | blocks for the additional addresses, and insert them into the chain. The | |
2155 | original name may not be fully qualified. Use the fully_qualified_name argument | |
2156 | to return the official name, as returned by the resolver. | |
2157 | ||
2158 | Arguments: | |
2159 | host point to initial host item | |
2160 | ignore_target_hosts a list of hosts to ignore | |
2161 | whichrrs flags indicating which RRs to look for: | |
2162 | HOST_FIND_BY_SRV => look for SRV | |
2163 | HOST_FIND_BY_MX => look for MX | |
2164 | HOST_FIND_BY_A => look for A or AAAA | |
2165 | also flags indicating how the lookup is done | |
2166 | HOST_FIND_QUALIFY_SINGLE ) passed to the | |
2167 | HOST_FIND_SEARCH_PARENTS ) resolver | |
2168 | srv_service when SRV used, the service name | |
2169 | srv_fail_domains DNS errors for these domains => assume nonexist | |
2170 | mx_fail_domains DNS errors for these domains => assume nonexist | |
2171 | fully_qualified_name if not NULL, return fully-qualified name | |
2172 | removed set TRUE if local host was removed from the list | |
2173 | ||
2174 | Returns: HOST_FIND_FAILED Failed to find the host or domain; | |
2175 | if there was a syntax error, | |
2176 | host_find_failed_syntax is set. | |
2177 | HOST_FIND_AGAIN Could not resolve at this time | |
2178 | HOST_FOUND Host found | |
2179 | HOST_FOUND_LOCAL The lowest MX record points to this | |
2180 | machine, if MX records were found, or | |
2181 | an A record that was found contains | |
2182 | an address of the local host | |
2183 | */ | |
2184 | ||
2185 | int | |
2186 | host_find_bydns(host_item *host, uschar *ignore_target_hosts, int whichrrs, | |
2187 | uschar *srv_service, uschar *srv_fail_domains, uschar *mx_fail_domains, | |
2188 | uschar **fully_qualified_name, BOOL *removed) | |
2189 | { | |
2190 | host_item *h, *last; | |
2191 | dns_record *rr; | |
2192 | int rc = DNS_FAIL; | |
2193 | int ind_type = 0; | |
2194 | int yield; | |
2195 | dns_answer dnsa; | |
2196 | dns_scan dnss; | |
2197 | ||
2198 | /* Set the default fully qualified name to the incoming name, initialize the | |
2199 | resolver if necessary, set up the relevant options, and initialize the flag | |
2200 | that gets set for DNS syntax check errors. */ | |
2201 | ||
2202 | if (fully_qualified_name != NULL) *fully_qualified_name = host->name; | |
2203 | dns_init((whichrrs & HOST_FIND_QUALIFY_SINGLE) != 0, | |
2204 | (whichrrs & HOST_FIND_SEARCH_PARENTS) != 0); | |
2205 | host_find_failed_syntax = FALSE; | |
2206 | ||
2207 | /* First, if requested, look for SRV records. The service name is given; we | |
2208 | assume TCP progocol. DNS domain names are constrained to a maximum of 256 | |
2209 | characters, so the code below should be safe. */ | |
2210 | ||
2211 | if ((whichrrs & HOST_FIND_BY_SRV) != 0) | |
2212 | { | |
2213 | uschar buffer[300]; | |
2214 | uschar *temp_fully_qualified_name = buffer; | |
2215 | int prefix_length; | |
2216 | ||
2217 | (void)sprintf(CS buffer, "_%s._tcp.%n%.256s", srv_service, &prefix_length, | |
2218 | host->name); | |
2219 | ind_type = T_SRV; | |
2220 | ||
2221 | /* Search for SRV records. If the fully qualified name is different to | |
2222 | the input name, pass back the new original domain, without the prepended | |
2223 | magic. */ | |
2224 | ||
2225 | rc = dns_lookup(&dnsa, buffer, ind_type, &temp_fully_qualified_name); | |
2226 | if (temp_fully_qualified_name != buffer && fully_qualified_name != NULL) | |
2227 | *fully_qualified_name = temp_fully_qualified_name + prefix_length; | |
2228 | ||
2229 | /* On DNS failures, we give the "try again" error unless the domain is | |
2230 | listed as one for which we continue. */ | |
2231 | ||
2232 | if (rc == DNS_FAIL || rc == DNS_AGAIN) | |
2233 | { | |
2234 | if (match_isinlist(host->name, &srv_fail_domains, 0, NULL, NULL, MCL_DOMAIN, | |
2235 | TRUE, NULL) != OK) | |
2236 | return HOST_FIND_AGAIN; | |
2237 | DEBUG(D_host_lookup) debug_printf("DNS_%s treated as DNS_NODATA " | |
2238 | "(domain in srv_fail_domains)\n", (rc == DNS_FAIL)? "FAIL":"AGAIN"); | |
2239 | } | |
2240 | } | |
2241 | ||
2242 | /* If we did not find any SRV records, search the DNS for MX records, if | |
2243 | requested to do so. If the result is DNS_NOMATCH, it means there is no such | |
2244 | domain, and there's no point in going on to look for address records with the | |
2245 | same domain. The result will be DNS_NODATA if the domain exists but has no MX | |
2246 | records. On DNS failures, we give the "try again" error unless the domain is | |
2247 | listed as one for which we continue. */ | |
2248 | ||
2249 | if (rc != DNS_SUCCEED && (whichrrs & HOST_FIND_BY_MX) != 0) | |
2250 | { | |
2251 | ind_type = T_MX; | |
2252 | rc = dns_lookup(&dnsa, host->name, ind_type, fully_qualified_name); | |
2253 | if (rc == DNS_NOMATCH) return HOST_FIND_FAILED; | |
2254 | if (rc == DNS_FAIL || rc == DNS_AGAIN) | |
2255 | { | |
2256 | if (match_isinlist(host->name, &mx_fail_domains, 0, NULL, NULL, MCL_DOMAIN, | |
2257 | TRUE, NULL) != OK) | |
2258 | return HOST_FIND_AGAIN; | |
2259 | DEBUG(D_host_lookup) debug_printf("DNS_%s treated as DNS_NODATA " | |
2260 | "(domain in mx_fail_domains)\n", (rc == DNS_FAIL)? "FAIL":"AGAIN"); | |
2261 | } | |
2262 | } | |
2263 | ||
2264 | /* If we haven't found anything yet, and we are requested to do so, try for an | |
2265 | A or AAAA record. If we find it (or them) check to see that it isn't the local | |
2266 | host. */ | |
2267 | ||
2268 | if (rc != DNS_SUCCEED) | |
2269 | { | |
2270 | if ((whichrrs & HOST_FIND_BY_A) == 0) | |
2271 | { | |
2272 | DEBUG(D_host_lookup) debug_printf("Address records are not being sought\n"); | |
2273 | return HOST_FIND_FAILED; | |
2274 | } | |
2275 | ||
2276 | last = host; /* End of local chainlet */ | |
2277 | host->mx = MX_NONE; | |
2278 | host->port = PORT_NONE; | |
2279 | rc = set_address_from_dns(host, &last, ignore_target_hosts, FALSE, | |
2280 | fully_qualified_name); | |
2281 | ||
2282 | /* If one or more address records have been found, check that none of them | |
2283 | are local. Since we know the host items all have their IP addresses | |
2284 | inserted, host_scan_for_local_hosts() can only return HOST_FOUND or | |
2285 | HOST_FOUND_LOCAL. We do not need to scan for duplicate IP addresses here, | |
2286 | because set_address_from_dns() removes them. */ | |
2287 | ||
2288 | if (rc == HOST_FOUND) | |
2289 | rc = host_scan_for_local_hosts(host, &last, removed); | |
2290 | else | |
2291 | if (rc == HOST_IGNORED) rc = HOST_FIND_FAILED; /* No special action */ | |
2292 | ||
d8ef3577 PH |
2293 | /* When running in the test harness, sort into the order of addresses so as |
2294 | to get repeatability. */ | |
8e669ac1 | 2295 | |
d8ef3577 PH |
2296 | if (running_in_test_harness) sort_addresses(host, last); |
2297 | ||
059ec3d9 PH |
2298 | DEBUG(D_host_lookup) |
2299 | { | |
2300 | host_item *h; | |
2301 | if (host->address != NULL) | |
2302 | { | |
2303 | if (fully_qualified_name != NULL) | |
2304 | debug_printf("fully qualified name = %s\n", *fully_qualified_name); | |
2305 | for (h = host; h != last->next; h = h->next) | |
2306 | debug_printf("%s %s mx=%d sort=%d %s\n", h->name, | |
2307 | (h->address == NULL)? US"<null>" : h->address, h->mx, h->sort_key, | |
2308 | (h->status >= hstatus_unusable)? US"*" : US""); | |
2309 | } | |
2310 | } | |
2311 | ||
2312 | return rc; | |
2313 | } | |
2314 | ||
2315 | /* We have found one or more MX or SRV records. Sort them according to | |
2316 | precedence. Put the data for the first one into the existing host block, and | |
2317 | insert new host_item blocks into the chain for the remainder. For equal | |
2318 | precedences one is supposed to randomize the order. To make this happen, the | |
2319 | sorting is actually done on the MX value * 1000 + a random number. This is put | |
2320 | into a host field called sort_key. | |
2321 | ||
2322 | In the case of hosts with both IPv6 and IPv4 addresses, we want to choose the | |
2323 | IPv6 address in preference. At this stage, we don't know what kind of address | |
2324 | the host has. We choose a random number < 500; if later we find an A record | |
2325 | first, we add 500 to the random number. Then for any other address records, we | |
2326 | use random numbers in the range 0-499 for AAAA records and 500-999 for A | |
2327 | records. | |
2328 | ||
2329 | At this point we remove any duplicates that point to the same host, retaining | |
2330 | only the one with the lowest precedence. We cannot yet check for precedence | |
2331 | greater than that of the local host, because that test cannot be properly done | |
2332 | until the addresses have been found - an MX record may point to a name for this | |
2333 | host which is not the primary hostname. */ | |
2334 | ||
2335 | last = NULL; /* Indicates that not even the first item is filled yet */ | |
2336 | ||
2337 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
2338 | rr != NULL; | |
2339 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2340 | { | |
2341 | int precedence; | |
2342 | int weight = 0; /* For SRV records */ | |
2343 | int port = PORT_NONE; /* For SRV records */ | |
2344 | uschar *s; /* MUST be unsigned for GETSHORT */ | |
2345 | uschar data[256]; | |
2346 | ||
2347 | if (rr->type != ind_type) continue; | |
2348 | s = rr->data; | |
2349 | GETSHORT(precedence, s); /* Pointer s is advanced */ | |
2350 | ||
2351 | /* For MX records, we use a random "weight" which causes multiple records of | |
2352 | the same precedence to sort randomly. */ | |
2353 | ||
2354 | if (ind_type == T_MX) | |
2355 | { | |
2356 | weight = random_number(500); | |
2357 | } | |
2358 | ||
2359 | /* SRV records are specified with a port and a weight. The weight is used | |
2360 | in a special algorithm. However, to start with, we just use it to order the | |
2361 | records of equal priority (precedence). */ | |
2362 | ||
2363 | else | |
2364 | { | |
2365 | GETSHORT(weight, s); | |
2366 | GETSHORT(port, s); | |
2367 | } | |
2368 | ||
2369 | /* Get the name of the host pointed to. */ | |
2370 | ||
2371 | (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, s, | |
2372 | (DN_EXPAND_ARG4_TYPE)data, sizeof(data)); | |
2373 | ||
2374 | /* Check that we haven't already got this host on the chain; if we have, | |
2375 | keep only the lower precedence. This situation shouldn't occur, but you | |
2376 | never know what junk might get into the DNS (and this case has been seen on | |
2377 | more than one occasion). */ | |
2378 | ||
2379 | if (last != NULL) /* This is not the first record */ | |
2380 | { | |
2381 | host_item *prev = NULL; | |
2382 | ||
2383 | for (h = host; h != last->next; prev = h, h = h->next) | |
2384 | { | |
2385 | if (strcmpic(h->name, data) == 0) | |
2386 | { | |
2387 | DEBUG(D_host_lookup) | |
2388 | debug_printf("discarded duplicate host %s (MX=%d)\n", data, | |
2389 | (precedence > h->mx)? precedence : h->mx); | |
2390 | if (precedence >= h->mx) goto NEXT_MX_RR; /* Skip greater precedence */ | |
2391 | if (h == host) /* Override first item */ | |
2392 | { | |
2393 | h->mx = precedence; | |
2394 | host->sort_key = precedence * 1000 + weight; | |
2395 | goto NEXT_MX_RR; | |
2396 | } | |
2397 | ||
2398 | /* Unwanted host item is not the first in the chain, so we can get | |
2399 | get rid of it by cutting it out. */ | |
2400 | ||
2401 | prev->next = h->next; | |
2402 | if (h == last) last = prev; | |
2403 | break; | |
2404 | } | |
2405 | } | |
2406 | } | |
2407 | ||
2408 | /* If this is the first MX or SRV record, put the data into the existing host | |
2409 | block. Otherwise, add a new block in the correct place; if it has to be | |
2410 | before the first block, copy the first block's data to a new second block. */ | |
2411 | ||
2412 | if (last == NULL) | |
2413 | { | |
2414 | host->name = string_copy_dnsdomain(data); | |
2415 | host->address = NULL; | |
2416 | host->port = port; | |
2417 | host->mx = precedence; | |
2418 | host->sort_key = precedence * 1000 + weight; | |
2419 | host->status = hstatus_unknown; | |
2420 | host->why = hwhy_unknown; | |
2421 | last = host; | |
2422 | } | |
2423 | ||
2424 | /* Make a new host item and seek the correct insertion place */ | |
2425 | ||
2426 | else | |
2427 | { | |
2428 | int sort_key = precedence * 1000 + weight; | |
2429 | host_item *next = store_get(sizeof(host_item)); | |
2430 | next->name = string_copy_dnsdomain(data); | |
2431 | next->address = NULL; | |
2432 | next->port = port; | |
2433 | next->mx = precedence; | |
2434 | next->sort_key = sort_key; | |
2435 | next->status = hstatus_unknown; | |
2436 | next->why = hwhy_unknown; | |
2437 | next->last_try = 0; | |
2438 | ||
2439 | /* Handle the case when we have to insert before the first item. */ | |
2440 | ||
2441 | if (sort_key < host->sort_key) | |
2442 | { | |
2443 | host_item htemp; | |
2444 | htemp = *host; | |
2445 | *host = *next; | |
2446 | *next = htemp; | |
2447 | host->next = next; | |
2448 | if (last == host) last = next; | |
2449 | } | |
2450 | ||
2451 | /* Else scan down the items we have inserted as part of this exercise; | |
2452 | don't go further. */ | |
2453 | ||
2454 | else | |
2455 | { | |
2456 | for (h = host; h != last; h = h->next) | |
2457 | { | |
2458 | if (sort_key < h->next->sort_key) | |
2459 | { | |
2460 | next->next = h->next; | |
2461 | h->next = next; | |
2462 | break; | |
2463 | } | |
2464 | } | |
2465 | ||
2466 | /* Join on after the last host item that's part of this | |
2467 | processing if we haven't stopped sooner. */ | |
2468 | ||
2469 | if (h == last) | |
2470 | { | |
2471 | next->next = last->next; | |
2472 | last->next = next; | |
2473 | last = next; | |
2474 | } | |
2475 | } | |
2476 | } | |
2477 | ||
2478 | NEXT_MX_RR: continue; | |
2479 | } | |
2480 | ||
2481 | /* If the list of hosts was obtained from SRV records, there are two things to | |
2482 | do. First, if there is only one host, and it's name is ".", it means there is | |
2483 | no SMTP service at this domain. Otherwise, we have to sort the hosts of equal | |
2484 | priority according to their weights, using an algorithm that is defined in RFC | |
2485 | 2782. The hosts are currently sorted by priority and weight. For each priority | |
2486 | group we have to pick off one host and put it first, and then repeat for any | |
2487 | remaining in the same priority group. */ | |
2488 | ||
2489 | if (ind_type == T_SRV) | |
2490 | { | |
2491 | host_item **pptr; | |
2492 | ||
2493 | if (host == last && host->name[0] == 0) | |
2494 | { | |
2495 | DEBUG(D_host_lookup) debug_printf("the single SRV record is \".\"\n"); | |
2496 | return HOST_FIND_FAILED; | |
2497 | } | |
2498 | ||
2499 | DEBUG(D_host_lookup) | |
2500 | { | |
2501 | debug_printf("original ordering of hosts from SRV records:\n"); | |
2502 | for (h = host; h != last->next; h = h->next) | |
2503 | debug_printf(" %s P=%d W=%d\n", h->name, h->mx, h->sort_key % 1000); | |
2504 | } | |
2505 | ||
2506 | for (pptr = &host, h = host; h != last; pptr = &(h->next), h = h->next) | |
2507 | { | |
2508 | int sum = 0; | |
2509 | host_item *hh; | |
2510 | ||
2511 | /* Find the last following host that has the same precedence. At the same | |
2512 | time, compute the sum of the weights and the running totals. These can be | |
2513 | stored in the sort_key field. */ | |
2514 | ||
2515 | for (hh = h; hh != last; hh = hh->next) | |
2516 | { | |
2517 | int weight = hh->sort_key % 1000; /* was precedence * 1000 + weight */ | |
2518 | sum += weight; | |
2519 | hh->sort_key = sum; | |
2520 | if (hh->mx != hh->next->mx) break; | |
2521 | } | |
2522 | ||
2523 | /* If there's more than one host at this precedence (priority), we need to | |
2524 | pick one to go first. */ | |
2525 | ||
2526 | if (hh != h) | |
2527 | { | |
2528 | host_item *hhh; | |
2529 | host_item **ppptr; | |
2530 | int randomizer = random_number(sum + 1); | |
2531 | ||
2532 | for (ppptr = pptr, hhh = h; | |
2533 | hhh != hh; | |
2534 | ppptr = &(hhh->next), hhh = hhh->next) | |
2535 | { | |
2536 | if (hhh->sort_key >= randomizer) break; | |
2537 | } | |
2538 | ||
2539 | /* hhh now points to the host that should go first; ppptr points to the | |
2540 | place that points to it. Unfortunately, if the start of the minilist is | |
2541 | the start of the entire list, we can't just swap the items over, because | |
2542 | we must not change the value of host, since it is passed in from outside. | |
2543 | One day, this could perhaps be changed. | |
2544 | ||
2545 | The special case is fudged by putting the new item *second* in the chain, | |
2546 | and then transferring the data between the first and second items. We | |
2547 | can't just swap the first and the chosen item, because that would mean | |
2548 | that an item with zero weight might no longer be first. */ | |
2549 | ||
2550 | if (hhh != h) | |
2551 | { | |
2552 | *ppptr = hhh->next; /* Cuts it out of the chain */ | |
2553 | ||
2554 | if (h == host) | |
2555 | { | |
2556 | host_item temp = *h; | |
2557 | *h = *hhh; | |
2558 | *hhh = temp; | |
2559 | hhh->next = temp.next; | |
2560 | h->next = hhh; | |
2561 | } | |
2562 | ||
2563 | else | |
2564 | { | |
2565 | hhh->next = h; /* The rest of the chain follows it */ | |
2566 | *pptr = hhh; /* It takes the place of h */ | |
2567 | h = hhh; /* It's now the start of this minilist */ | |
2568 | } | |
2569 | } | |
2570 | } | |
2571 | ||
2572 | /* A host has been chosen to be first at this priority and h now points | |
2573 | to this host. There may be others at the same priority, or others at a | |
2574 | different priority. Before we leave this host, we need to put back a sort | |
2575 | key of the traditional MX kind, in case this host is multihomed, because | |
2576 | the sort key is used for ordering the multiple IP addresses. We do not need | |
2577 | to ensure that these new sort keys actually reflect the order of the hosts, | |
2578 | however. */ | |
2579 | ||
2580 | h->sort_key = h->mx * 1000 + random_number(500); | |
2581 | } /* Move on to the next host */ | |
2582 | } | |
2583 | ||
2584 | /* Now we have to ensure addresses exist for all the hosts. We have ensured | |
2585 | above that the names in the host items are all unique. The addresses may have | |
2586 | been returned in the additional data section of the DNS query. Because it is | |
2587 | more expensive to scan the returned DNS records (because you have to expand the | |
2588 | names) we do a single scan over them, and multiple scans of the chain of host | |
2589 | items (which is typically only 3 or 4 long anyway.) Add extra host items for | |
2590 | multi-homed hosts. */ | |
2591 | ||
2592 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ADDITIONAL); | |
2593 | rr != NULL; | |
2594 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2595 | { | |
2596 | dns_address *da; | |
2597 | int status = hstatus_unknown; | |
2598 | int why = hwhy_unknown; | |
2599 | int randoffset; | |
2600 | ||
2601 | if (rr->type != T_A | |
2602 | #if HAVE_IPV6 | |
2603 | && rr->type != T_AAAA | |
2604 | #ifdef SUPPORT_A6 | |
2605 | && rr->type != T_A6 | |
2606 | #endif | |
2607 | #endif | |
2608 | ) continue; | |
2609 | ||
2610 | /* Find the first host that matches this record's name. If there isn't | |
2611 | one, move on to the next RR. */ | |
2612 | ||
2613 | for (h = host; h != last->next; h = h->next) | |
2614 | { if (strcmpic(h->name, rr->name) == 0) break; } | |
2615 | if (h == last->next) continue; | |
2616 | ||
2617 | /* For IPv4 addresses, add 500 to the random part of the sort key, to ensure | |
2618 | they sort after IPv6 addresses. */ | |
2619 | ||
2620 | randoffset = (rr->type == T_A)? 500 : 0; | |
2621 | ||
2622 | /* Get the list of textual addresses for this RR. There may be more than one | |
2623 | if it is an A6 RR. Then loop to handle multiple addresses from an A6 record. | |
2624 | If there are none, nothing will get done - the record is ignored. */ | |
2625 | ||
2626 | for (da = dns_address_from_rr(&dnsa, rr); da != NULL; da = da->next) | |
2627 | { | |
2628 | /* Set status for an ignorable host. */ | |
2629 | ||
2630 | #ifndef STAND_ALONE | |
2631 | if (ignore_target_hosts != NULL && | |
2632 | verify_check_this_host(&ignore_target_hosts, NULL, h->name, | |
2633 | da->address, NULL) == OK) | |
2634 | { | |
2635 | DEBUG(D_host_lookup) | |
2636 | debug_printf("ignored host %s [%s]\n", h->name, da->address); | |
2637 | status = hstatus_unusable; | |
2638 | why = hwhy_ignored; | |
2639 | } | |
2640 | #endif | |
2641 | ||
2642 | /* If the address is already set for this host, it may be that | |
2643 | we just have a duplicate DNS record. Alternatively, this may be | |
2644 | a multi-homed host. Search all items with the same host name | |
2645 | (they will all be together) and if this address is found, skip | |
2646 | to the next RR. */ | |
2647 | ||
2648 | if (h->address != NULL) | |
2649 | { | |
2650 | int new_sort_key; | |
2651 | host_item *thishostlast; | |
2652 | host_item *hh = h; | |
2653 | ||
2654 | do | |
2655 | { | |
2656 | if (hh->address != NULL && Ustrcmp(CS da->address, hh->address) == 0) | |
2657 | goto DNS_NEXT_RR; /* Need goto to escape from inner loop */ | |
2658 | thishostlast = hh; | |
2659 | hh = hh->next; | |
2660 | } | |
2661 | while (hh != last->next && strcmpic(hh->name, rr->name) == 0); | |
2662 | ||
2663 | /* We have a multi-homed host, since we have a new address for | |
2664 | an existing name. Create a copy of the current item, and give it | |
2665 | the new address. RRs can be in arbitrary order, but one is supposed | |
2666 | to randomize the addresses of multi-homed hosts, so compute a new | |
2667 | sorting key and do that. [Latest SMTP RFC says not to randomize multi- | |
2668 | homed hosts, but to rely on the resolver. I'm not happy about that - | |
2669 | caching in the resolver will not rotate as often as the name server | |
2670 | does.] */ | |
2671 | ||
2672 | new_sort_key = h->mx * 1000 + random_number(500) + randoffset; | |
2673 | hh = store_get(sizeof(host_item)); | |
2674 | ||
2675 | /* New address goes first: insert the new block after the first one | |
2676 | (so as not to disturb the original pointer) but put the new address | |
2677 | in the original block. */ | |
2678 | ||
2679 | if (new_sort_key < h->sort_key) | |
2680 | { | |
2681 | *hh = *h; /* Note: copies the port */ | |
2682 | h->next = hh; | |
2683 | h->address = da->address; | |
2684 | h->sort_key = new_sort_key; | |
2685 | h->status = status; | |
2686 | h->why = why; | |
2687 | } | |
2688 | ||
2689 | /* Otherwise scan down the addresses for this host to find the | |
2690 | one to insert after. */ | |
2691 | ||
2692 | else | |
2693 | { | |
2694 | while (h != thishostlast) | |
2695 | { | |
2696 | if (new_sort_key < h->next->sort_key) break; | |
2697 | h = h->next; | |
2698 | } | |
2699 | *hh = *h; /* Note: copies the port */ | |
2700 | h->next = hh; | |
2701 | hh->address = da->address; | |
2702 | hh->sort_key = new_sort_key; | |
2703 | hh->status = status; | |
2704 | hh->why = why; | |
2705 | } | |
2706 | ||
2707 | if (h == last) last = hh; /* Inserted after last */ | |
2708 | } | |
2709 | ||
2710 | /* The existing item doesn't have its address set yet, so just set it. | |
2711 | Ensure that an IPv4 address gets its sort key incremented in case an IPv6 | |
2712 | address is found later. */ | |
2713 | ||
2714 | else | |
2715 | { | |
2716 | h->address = da->address; /* Port should be set already */ | |
2717 | h->status = status; | |
2718 | h->why = why; | |
2719 | h->sort_key += randoffset; | |
2720 | } | |
2721 | } /* Loop for addresses extracted from one RR */ | |
2722 | ||
2723 | /* Carry on to the next RR. It would be nice to be able to be able to stop | |
2724 | when every host on the list has an address, but we can't be sure there won't | |
2725 | be an additional address for a multi-homed host further down the list, so | |
2726 | we have to continue to the end. */ | |
2727 | ||
2728 | DNS_NEXT_RR: continue; | |
2729 | } | |
2730 | ||
2731 | /* Set the default yield to failure */ | |
2732 | ||
2733 | yield = HOST_FIND_FAILED; | |
2734 | ||
2735 | /* If we haven't found all the addresses in the additional section, we | |
2736 | need to search for A or AAAA records explicitly. The names shouldn't point to | |
2737 | CNAMES, but we use the general lookup function that handles them, just | |
2738 | in case. If any lookup gives a soft error, change the default yield. | |
2739 | ||
2740 | For these DNS lookups, we must disable qualify_single and search_parents; | |
2741 | otherwise invalid host names obtained from MX or SRV records can cause trouble | |
2742 | if they happen to match something local. */ | |
2743 | ||
2744 | dns_init(FALSE, FALSE); | |
2745 | ||
2746 | for (h = host; h != last->next; h = h->next) | |
2747 | { | |
2748 | if (h->address != NULL || h->status == hstatus_unusable) continue; | |
2749 | rc = set_address_from_dns(h, &last, ignore_target_hosts, allow_mx_to_ip, NULL); | |
2750 | if (rc != HOST_FOUND) | |
2751 | { | |
2752 | h->status = hstatus_unusable; | |
2753 | if (rc == HOST_FIND_AGAIN) | |
2754 | { | |
2755 | yield = rc; | |
2756 | h->why = hwhy_deferred; | |
2757 | } | |
2758 | else | |
2759 | h->why = (rc == HOST_IGNORED)? hwhy_ignored : hwhy_failed; | |
2760 | } | |
2761 | } | |
2762 | ||
2763 | /* Scan the list for any hosts that are marked unusable because they have | |
2764 | been explicitly ignored, and remove them from the list, as if they did not | |
2765 | exist. If we end up with just a single, ignored host, flatten its fields as if | |
2766 | nothing was found. */ | |
2767 | ||
2768 | if (ignore_target_hosts != NULL) | |
2769 | { | |
2770 | host_item *prev = NULL; | |
2771 | for (h = host; h != last->next; h = h->next) | |
2772 | { | |
2773 | REDO: | |
2774 | if (h->why != hwhy_ignored) /* Non ignored host, just continue */ | |
2775 | prev = h; | |
2776 | else if (prev == NULL) /* First host is ignored */ | |
2777 | { | |
2778 | if (h != last) /* First is not last */ | |
2779 | { | |
2780 | if (h->next == last) last = h; /* Overwrite it with next */ | |
2781 | *h = *(h->next); /* and reprocess it. */ | |
2782 | goto REDO; /* C should have redo, like Perl */ | |
2783 | } | |
2784 | } | |
2785 | else /* Ignored host is not first - */ | |
2786 | { /* cut it out */ | |
2787 | prev->next = h->next; | |
2788 | if (h == last) last = prev; | |
2789 | } | |
2790 | } | |
2791 | ||
2792 | if (host->why == hwhy_ignored) host->address = NULL; | |
2793 | } | |
2794 | ||
2795 | /* There is still one complication in the case of IPv6. Although the code above | |
2796 | arranges that IPv6 addresses take precedence over IPv4 addresses for multihomed | |
2797 | hosts, it doesn't do this for addresses that apply to different hosts with the | |
2798 | same MX precedence, because the sorting on MX precedence happens first. So we | |
2799 | have to make another pass to check for this case. We ensure that, within a | |
2800 | single MX preference value, IPv6 addresses come first. This can separate the | |
2801 | addresses of a multihomed host, but that should not matter. */ | |
2802 | ||
2803 | #if HAVE_IPV6 | |
2804 | if (h != last) | |
2805 | { | |
2806 | for (h = host; h != last; h = h->next) | |
2807 | { | |
2808 | host_item temp; | |
2809 | host_item *next = h->next; | |
2810 | if (h->mx != next->mx || /* If next is different MX value */ | |
2811 | (h->sort_key % 1000) < 500 || /* OR this one is IPv6 */ | |
2812 | (next->sort_key % 1000) >= 500) /* OR next is IPv4 */ | |
2813 | continue; /* move on to next */ | |
2814 | temp = *h; | |
2815 | temp.next = next->next; | |
2816 | *h = *next; | |
2817 | h->next = next; | |
2818 | *next = temp; | |
2819 | } | |
2820 | } | |
2821 | #endif | |
2822 | ||
2823 | /* When running in the test harness, we want the hosts always to be in the same | |
2824 | order so that the debugging output is the same and can be compared. Having a | |
2825 | fixed set of "random" numbers doesn't actually achieve this, because the RRs | |
2826 | come back from the resolver in a random order, so the non-random random numbers | |
2827 | get used in a different order. We therefore have to sort the hosts that have | |
2828 | the same MX values. We chose do to this by their name and then by IP address. | |
2829 | The fact that the sort is slow matters not - this is testing only! */ | |
2830 | ||
2831 | if (running_in_test_harness) | |
2832 | { | |
2833 | BOOL done; | |
2834 | do | |
2835 | { | |
2836 | done = TRUE; | |
2837 | for (h = host; h != last; h = h->next) | |
2838 | { | |
2839 | int c = Ustrcmp(h->name, h->next->name); | |
2840 | if (c == 0) c = Ustrcmp(h->address, h->next->address); | |
2841 | if (h->mx == h->next->mx && c > 0) | |
2842 | { | |
2843 | host_item *next = h->next; | |
2844 | host_item temp = *h; | |
2845 | temp.next = next->next; | |
2846 | *h = *next; | |
2847 | h->next = next; | |
2848 | *next = temp; | |
2849 | done = FALSE; | |
2850 | } | |
2851 | } | |
2852 | } | |
2853 | while (!done); | |
2854 | } | |
2855 | ||
2856 | /* Remove any duplicate IP addresses and then scan the list of hosts for any | |
2857 | whose IP addresses are on the local host. If any are found, all hosts with the | |
2858 | same or higher MX values are removed. However, if the local host has the lowest | |
2859 | numbered MX, then HOST_FOUND_LOCAL is returned. Otherwise, if at least one host | |
2860 | with an IP address is on the list, HOST_FOUND is returned. Otherwise, | |
2861 | HOST_FIND_FAILED is returned, but in this case do not update the yield, as it | |
2862 | might have been set to HOST_FIND_AGAIN just above here. If not, it will already | |
2863 | be HOST_FIND_FAILED. */ | |
2864 | ||
2865 | host_remove_duplicates(host, &last); | |
2866 | rc = host_scan_for_local_hosts(host, &last, removed); | |
2867 | if (rc != HOST_FIND_FAILED) yield = rc; | |
2868 | ||
2869 | DEBUG(D_host_lookup) | |
2870 | { | |
2871 | if (fully_qualified_name != NULL) | |
2872 | debug_printf("fully qualified name = %s\n", *fully_qualified_name); | |
2873 | debug_printf("host_find_bydns yield = %s (%d); returned hosts:\n", | |
2874 | (yield == HOST_FOUND)? "HOST_FOUND" : | |
2875 | (yield == HOST_FOUND_LOCAL)? "HOST_FOUND_LOCAL" : | |
2876 | (yield == HOST_FIND_AGAIN)? "HOST_FIND_AGAIN" : | |
2877 | (yield == HOST_FIND_FAILED)? "HOST_FIND_FAILED" : "?", | |
2878 | yield); | |
2879 | for (h = host; h != last->next; h = h->next) | |
2880 | { | |
2881 | debug_printf(" %s %s MX=%d ", h->name, | |
2882 | (h->address == NULL)? US"<null>" : h->address, h->mx); | |
2883 | if (h->port != PORT_NONE) debug_printf("port=%d ", h->port); | |
2884 | if (h->status >= hstatus_unusable) debug_printf("*"); | |
2885 | debug_printf("\n"); | |
2886 | } | |
2887 | } | |
2888 | ||
2889 | return yield; | |
2890 | } | |
2891 | ||
2892 | ||
2893 | ||
2894 | ||
2895 | /************************************************* | |
2896 | ************************************************** | |
2897 | * Stand-alone test program * | |
2898 | ************************************************** | |
2899 | *************************************************/ | |
2900 | ||
2901 | #ifdef STAND_ALONE | |
2902 | ||
2903 | BOOL alldigits(uschar *buffer) | |
2904 | { | |
2905 | if (!isdigit(*buffer)) return FALSE; | |
2906 | if (*buffer == '0' && buffer[1] == 'x') | |
2907 | { | |
2908 | buffer++; | |
2909 | while (isxdigit(*(++buffer))); | |
2910 | } | |
2911 | else while (isdigit(*(++buffer))); | |
2912 | return (*buffer == 0); | |
2913 | } | |
2914 | ||
2915 | int main(int argc, char **cargv) | |
2916 | { | |
2917 | host_item h; | |
2918 | int whichrrs = HOST_FIND_BY_MX | HOST_FIND_BY_A; | |
2919 | BOOL byname = FALSE; | |
2920 | BOOL qualify_single = TRUE; | |
2921 | BOOL search_parents = FALSE; | |
2922 | uschar **argv = USS cargv; | |
2923 | uschar buffer[256]; | |
2924 | ||
2925 | primary_hostname = US""; | |
2926 | store_pool = POOL_MAIN; | |
2927 | debug_selector = D_host_lookup|D_interface; | |
2928 | debug_file = stdout; | |
2929 | debug_fd = fileno(debug_file); | |
2930 | ||
2931 | printf("Exim stand-alone host functions test\n"); | |
2932 | ||
2933 | host_find_interfaces(); | |
2934 | debug_selector = D_host_lookup | D_dns; | |
2935 | ||
2936 | if (argc > 1) primary_hostname = argv[1]; | |
2937 | ||
2938 | /* So that debug level changes can be done first */ | |
2939 | ||
2940 | dns_init(qualify_single, search_parents); | |
2941 | ||
2942 | printf("Testing host lookup\n"); | |
2943 | printf("> "); | |
2944 | while (Ufgets(buffer, 256, stdin) != NULL) | |
2945 | { | |
2946 | int rc; | |
2947 | int len = Ustrlen(buffer); | |
2948 | uschar *fully_qualified_name; | |
2949 | ||
2950 | while (len > 0 && isspace(buffer[len-1])) len--; | |
2951 | buffer[len] = 0; | |
2952 | ||
2953 | if (Ustrcmp(buffer, "q") == 0) break; | |
2954 | ||
2955 | if (Ustrcmp(buffer, "byname") == 0) byname = TRUE; | |
2956 | else if (Ustrcmp(buffer, "no_byname") == 0) byname = FALSE; | |
2957 | else if (Ustrcmp(buffer, "a_only") == 0) whichrrs = HOST_FIND_BY_A; | |
2958 | else if (Ustrcmp(buffer, "mx_only") == 0) whichrrs = HOST_FIND_BY_MX; | |
2959 | else if (Ustrcmp(buffer, "srv_only") == 0) whichrrs = HOST_FIND_BY_SRV; | |
2960 | else if (Ustrcmp(buffer, "srv+a") == 0) | |
2961 | whichrrs = HOST_FIND_BY_SRV | HOST_FIND_BY_A; | |
2962 | else if (Ustrcmp(buffer, "srv+mx") == 0) | |
2963 | whichrrs = HOST_FIND_BY_SRV | HOST_FIND_BY_MX; | |
2964 | else if (Ustrcmp(buffer, "srv+mx+a") == 0) | |
2965 | whichrrs = HOST_FIND_BY_SRV | HOST_FIND_BY_MX | HOST_FIND_BY_A; | |
2966 | else if (Ustrcmp(buffer, "qualify_single") == 0) qualify_single = TRUE; | |
2967 | else if (Ustrcmp(buffer, "no_qualify_single") == 0) qualify_single = FALSE; | |
2968 | else if (Ustrcmp(buffer, "search_parents") == 0) search_parents = TRUE; | |
2969 | else if (Ustrcmp(buffer, "no_search_parents") == 0) search_parents = FALSE; | |
2970 | else if (Ustrncmp(buffer, "retrans", 7) == 0) | |
2971 | { | |
2972 | sscanf(CS(buffer+8), "%d", &dns_retrans); | |
2973 | _res.retrans = dns_retrans; | |
2974 | } | |
2975 | else if (Ustrncmp(buffer, "retry", 5) == 0) | |
2976 | { | |
2977 | sscanf(CS(buffer+6), "%d", &dns_retry); | |
2978 | _res.retry = dns_retry; | |
2979 | } | |
2980 | else if (alldigits(buffer)) | |
2981 | { | |
2982 | debug_selector = Ustrtol(buffer, NULL, 0); | |
2983 | _res.options &= ~RES_DEBUG; | |
2984 | DEBUG(D_resolver) _res.options |= RES_DEBUG; | |
2985 | } | |
2986 | else | |
2987 | { | |
2988 | int flags = whichrrs; | |
2989 | ||
2990 | h.name = buffer; | |
2991 | h.next = NULL; | |
2992 | h.mx = MX_NONE; | |
2993 | h.port = PORT_NONE; | |
2994 | h.status = hstatus_unknown; | |
2995 | h.why = hwhy_unknown; | |
2996 | h.address = NULL; | |
2997 | ||
2998 | if (qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE; | |
2999 | if (search_parents) flags |= HOST_FIND_SEARCH_PARENTS; | |
3000 | ||
3001 | rc = byname? | |
3002 | host_find_byname(&h, NULL, &fully_qualified_name, TRUE) | |
3003 | : | |
3004 | host_find_bydns(&h, NULL, flags, US"smtp", NULL, NULL, | |
3005 | &fully_qualified_name, NULL); | |
3006 | ||
3007 | if (rc == HOST_FIND_FAILED) printf("Failed\n"); | |
3008 | else if (rc == HOST_FIND_AGAIN) printf("Again\n"); | |
3009 | else if (rc == HOST_FOUND_LOCAL) printf("Local\n"); | |
3010 | } | |
3011 | ||
3012 | printf("\n> "); | |
3013 | } | |
3014 | ||
3015 | printf("Testing host_aton\n"); | |
3016 | printf("> "); | |
3017 | while (Ufgets(buffer, 256, stdin) != NULL) | |
3018 | { | |
3019 | int i; | |
3020 | int x[4]; | |
3021 | int len = Ustrlen(buffer); | |
3022 | ||
3023 | while (len > 0 && isspace(buffer[len-1])) len--; | |
3024 | buffer[len] = 0; | |
3025 | ||
3026 | if (Ustrcmp(buffer, "q") == 0) break; | |
3027 | ||
3028 | len = host_aton(buffer, x); | |
3029 | printf("length = %d ", len); | |
3030 | for (i = 0; i < len; i++) | |
3031 | { | |
3032 | printf("%04x ", (x[i] >> 16) & 0xffff); | |
3033 | printf("%04x ", x[i] & 0xffff); | |
3034 | } | |
3035 | printf("\n> "); | |
3036 | } | |
3037 | ||
3038 | printf("\n"); | |
3039 | ||
3040 | printf("Testing host_name_lookup\n"); | |
3041 | printf("> "); | |
3042 | while (Ufgets(buffer, 256, stdin) != NULL) | |
3043 | { | |
3044 | int len = Ustrlen(buffer); | |
3045 | while (len > 0 && isspace(buffer[len-1])) len--; | |
3046 | buffer[len] = 0; | |
3047 | if (Ustrcmp(buffer, "q") == 0) break; | |
3048 | sender_host_address = buffer; | |
3049 | sender_host_name = NULL; | |
3050 | sender_host_aliases = NULL; | |
3051 | host_lookup_msg = US""; | |
3052 | host_lookup_failed = FALSE; | |
3053 | if (host_name_lookup() == FAIL) /* Debug causes printing */ | |
3054 | printf("Lookup failed:%s\n", host_lookup_msg); | |
3055 | printf("\n> "); | |
3056 | } | |
3057 | ||
3058 | printf("\n"); | |
3059 | ||
3060 | return 0; | |
3061 | } | |
3062 | #endif /* STAND_ALONE */ | |
3063 | ||
3064 | /* End of host.c */ |