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5dd9625b | 1 | /* $Cambridge: exim/src/src/host.c,v 1.13 2005/08/22 15:28:20 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 | ||
2548ba04 PH |
43 | August 2005: Apparently this is also needed for AIX systems; USE_INET_NTOA_FIX |
44 | should now be set for them as well. | |
45 | ||
059ec3d9 PH |
46 | Arguments: sa an in_addr structure |
47 | Returns: pointer to static text string | |
48 | */ | |
49 | ||
50 | char * | |
51 | inet_ntoa(struct in_addr sa) | |
52 | { | |
53 | static uschar addr[20]; | |
54 | sprintf(addr, "%d.%d.%d.%d", | |
55 | (US &sa.s_addr)[0], | |
56 | (US &sa.s_addr)[1], | |
57 | (US &sa.s_addr)[2], | |
58 | (US &sa.s_addr)[3]); | |
59 | return addr; | |
60 | } | |
61 | #endif | |
62 | ||
63 | ||
64 | ||
65 | /************************************************* | |
66 | * Random number generator * | |
67 | *************************************************/ | |
68 | ||
69 | /* This is a simple pseudo-random number generator. It does not have to be | |
70 | very good for the uses to which it is put. When running the regression tests, | |
71 | start with a fixed seed. | |
72 | ||
73 | Arguments: | |
74 | limit: one more than the largest number required | |
75 | ||
76 | Returns: a pseudo-random number in the range 0 to limit-1 | |
77 | */ | |
78 | ||
79 | int | |
80 | random_number(int limit) | |
81 | { | |
82 | if (random_seed == 0) | |
83 | { | |
84 | if (running_in_test_harness) random_seed = 42; else | |
85 | { | |
86 | int p = (int)getpid(); | |
87 | random_seed = (int)time(NULL) ^ ((p << 16) | p); | |
88 | } | |
89 | } | |
90 | random_seed = 1103515245 * random_seed + 12345; | |
91 | return (unsigned int)(random_seed >> 16) % limit; | |
92 | } | |
93 | ||
94 | ||
95 | ||
d8ef3577 PH |
96 | /************************************************* |
97 | * Sort addresses when testing * | |
98 | *************************************************/ | |
99 | ||
100 | /* This function is called only when running in the test harness. It sorts a | |
101 | number of multihomed host IP addresses into the order, so as to get | |
102 | repeatability. This doesn't have to be efficient. But don't interchange IPv4 | |
103 | and IPv6 addresses! | |
104 | ||
105 | Arguments: | |
106 | host -> the first host item | |
107 | last -> the last host item | |
8e669ac1 | 108 | |
d8ef3577 | 109 | Returns: nothing |
8e669ac1 | 110 | */ |
d8ef3577 PH |
111 | |
112 | static void | |
113 | sort_addresses(host_item *host, host_item *last) | |
114 | { | |
115 | BOOL done = FALSE; | |
116 | while (!done) | |
117 | { | |
118 | host_item *h; | |
119 | done = TRUE; | |
120 | for (h = host; h != last; h = h->next) | |
121 | { | |
122 | if ((Ustrchr(h->address, ':') == NULL) != | |
123 | (Ustrchr(h->next->address, ':') == NULL)) | |
124 | continue; | |
125 | if (Ustrcmp(h->address, h->next->address) > 0) | |
126 | { | |
127 | uschar *temp = h->address; | |
128 | h->address = h->next->address; | |
129 | h->next->address = temp; | |
130 | done = FALSE; | |
131 | } | |
132 | } | |
133 | } | |
134 | } | |
135 | ||
136 | ||
137 | ||
059ec3d9 PH |
138 | /************************************************* |
139 | * Build chain of host items from list * | |
140 | *************************************************/ | |
141 | ||
142 | /* This function builds a chain of host items from a textual list of host | |
143 | names. It does not do any lookups. If randomize is true, the chain is build in | |
144 | a randomized order. There may be multiple groups of independently randomized | |
145 | hosts; they are delimited by a host name consisting of just "+". | |
146 | ||
147 | Arguments: | |
148 | anchor anchor for the chain | |
149 | list text list | |
150 | randomize TRUE for randomizing | |
151 | ||
152 | Returns: nothing | |
153 | */ | |
154 | ||
155 | void | |
156 | host_build_hostlist(host_item **anchor, uschar *list, BOOL randomize) | |
157 | { | |
158 | int sep = 0; | |
159 | int fake_mx = MX_NONE; /* This value is actually -1 */ | |
160 | uschar *name; | |
161 | uschar buffer[1024]; | |
162 | ||
163 | if (list == NULL) return; | |
164 | if (randomize) fake_mx--; /* Start at -2 for randomizing */ | |
165 | ||
166 | *anchor = NULL; | |
167 | ||
168 | while ((name = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) | |
169 | { | |
170 | host_item *h; | |
171 | ||
172 | if (name[0] == '+' && name[1] == 0) /* "+" delimits a randomized group */ | |
173 | { /* ignore if not randomizing */ | |
174 | if (randomize) fake_mx--; | |
175 | continue; | |
176 | } | |
177 | ||
178 | h = store_get(sizeof(host_item)); | |
179 | h->name = string_copy(name); | |
180 | h->address = NULL; | |
181 | h->port = PORT_NONE; | |
182 | h->mx = fake_mx; | |
183 | h->sort_key = randomize? (-fake_mx)*1000 + random_number(1000) : 0; | |
184 | h->status = hstatus_unknown; | |
185 | h->why = hwhy_unknown; | |
186 | h->last_try = 0; | |
187 | ||
188 | if (*anchor == NULL) | |
189 | { | |
190 | h->next = NULL; | |
191 | *anchor = h; | |
192 | } | |
193 | else | |
194 | { | |
195 | host_item *hh = *anchor; | |
196 | if (h->sort_key < hh->sort_key) | |
197 | { | |
198 | h->next = hh; | |
199 | *anchor = h; | |
200 | } | |
201 | else | |
202 | { | |
203 | while (hh->next != NULL && h->sort_key >= (hh->next)->sort_key) | |
204 | hh = hh->next; | |
205 | h->next = hh->next; | |
206 | hh->next = h; | |
207 | } | |
208 | } | |
209 | } | |
210 | } | |
211 | ||
212 | ||
213 | ||
214 | ||
215 | ||
216 | /************************************************* | |
217 | * Extract port from address string * | |
218 | *************************************************/ | |
219 | ||
220 | /* In the spool file, and in the -oMa and -oMi options, a host plus port is | |
221 | given as an IP address followed by a dot and a port number. This function | |
222 | decodes this. | |
223 | ||
224 | An alternative format for the -oMa and -oMi options is [ip address]:port which | |
225 | is what Exim 4 uses for output, because it seems to becoming commonly used, | |
226 | whereas the dot form confuses some programs/people. So we recognize that form | |
227 | too. | |
228 | ||
229 | Argument: | |
230 | address points to the string; if there is a port, the '.' in the string | |
231 | is overwritten with zero to terminate the address; if the string | |
232 | is in the [xxx]:ppp format, the address is shifted left and the | |
233 | brackets are removed | |
234 | ||
235 | Returns: 0 if there is no port, else the port number. If there's a syntax | |
236 | error, leave the incoming address alone, and return 0. | |
237 | */ | |
238 | ||
239 | int | |
7cd1141b | 240 | host_address_extract_port(uschar *address) |
059ec3d9 PH |
241 | { |
242 | int port = 0; | |
243 | uschar *endptr; | |
244 | ||
245 | /* Handle the "bracketed with colon on the end" format */ | |
246 | ||
247 | if (*address == '[') | |
248 | { | |
249 | uschar *rb = address + 1; | |
250 | while (*rb != 0 && *rb != ']') rb++; | |
251 | if (*rb++ == 0) return 0; /* Missing ]; leave invalid address */ | |
252 | if (*rb == ':') | |
253 | { | |
254 | port = Ustrtol(rb + 1, &endptr, 10); | |
255 | if (*endptr != 0) return 0; /* Invalid port; leave invalid address */ | |
256 | } | |
257 | else if (*rb != 0) return 0; /* Bad syntax; leave invalid address */ | |
258 | memmove(address, address + 1, rb - address - 2); | |
259 | rb[-2] = 0; | |
260 | } | |
261 | ||
262 | /* Handle the "dot on the end" format */ | |
263 | ||
264 | else | |
265 | { | |
266 | int skip = -3; /* Skip 3 dots in IPv4 addresses */ | |
267 | address--; | |
268 | while (*(++address) != 0) | |
269 | { | |
270 | int ch = *address; | |
271 | if (ch == ':') skip = 0; /* Skip 0 dots in IPv6 addresses */ | |
272 | else if (ch == '.' && skip++ >= 0) break; | |
273 | } | |
274 | if (*address == 0) return 0; | |
275 | port = Ustrtol(address + 1, &endptr, 10); | |
276 | if (*endptr != 0) return 0; /* Invalid port; leave invalid address */ | |
277 | *address = 0; | |
278 | } | |
279 | ||
280 | return port; | |
281 | } | |
282 | ||
283 | ||
7cd1141b PH |
284 | /************************************************* |
285 | * Get port from a host item's name * | |
286 | *************************************************/ | |
287 | ||
288 | /* This function is called when finding the IP address for a host that is in a | |
289 | list of hosts explicitly configured, such as in the manualroute router, or in a | |
290 | fallback hosts list. We see if there is a port specification at the end of the | |
291 | host name, and if so, remove it. A minimum length of 3 is required for the | |
292 | original name; nothing shorter is recognized as having a port. | |
293 | ||
294 | We test for a name ending with a sequence of digits; if preceded by colon we | |
295 | have a port if the character before the colon is ] and the name starts with [ | |
296 | or if there are no other colons in the name (i.e. it's not an IPv6 address). | |
297 | ||
298 | Arguments: pointer to the host item | |
299 | Returns: a port number or PORT_NONE | |
300 | */ | |
301 | ||
302 | int | |
303 | host_item_get_port(host_item *h) | |
304 | { | |
305 | uschar *p; | |
306 | int port, x; | |
307 | int len = Ustrlen(h->name); | |
308 | ||
309 | if (len < 3 || (p = h->name + len - 1, !isdigit(*p))) return PORT_NONE; | |
310 | ||
311 | /* Extract potential port number */ | |
312 | ||
313 | port = *p-- - '0'; | |
314 | x = 10; | |
315 | ||
316 | while (p > h->name + 1 && isdigit(*p)) | |
317 | { | |
318 | port += (*p-- - '0') * x; | |
319 | x *= 10; | |
320 | } | |
321 | ||
322 | /* The smallest value of p at this point is h->name + 1. */ | |
323 | ||
324 | if (*p != ':') return PORT_NONE; | |
325 | ||
326 | if (p[-1] == ']' && h->name[0] == '[') | |
327 | h->name = string_copyn(h->name + 1, p - h->name - 2); | |
328 | else if (Ustrchr(h->name, ':') == p) | |
329 | h->name = string_copyn(h->name, p - h->name); | |
330 | else return PORT_NONE; | |
331 | ||
332 | DEBUG(D_route|D_host_lookup) debug_printf("host=%s port=%d\n", h->name, port); | |
333 | return port; | |
334 | } | |
335 | ||
336 | ||
059ec3d9 PH |
337 | |
338 | #ifndef STAND_ALONE /* Omit when standalone testing */ | |
339 | ||
340 | /************************************************* | |
341 | * Build sender_fullhost and sender_rcvhost * | |
342 | *************************************************/ | |
343 | ||
344 | /* This function is called when sender_host_name and/or sender_helo_name | |
345 | have been set. Or might have been set - for a local message read off the spool | |
346 | they won't be. In that case, do nothing. Otherwise, set up the fullhost string | |
347 | as follows: | |
348 | ||
349 | (a) No sender_host_name or sender_helo_name: "[ip address]" | |
350 | (b) Just sender_host_name: "host_name [ip address]" | |
351 | (c) Just sender_helo_name: "(helo_name) [ip address]" | |
352 | (d) The two are identical: "host_name [ip address]" | |
353 | (e) The two are different: "host_name (helo_name) [ip address]" | |
354 | ||
355 | If log_incoming_port is set, the sending host's port number is added to the IP | |
356 | address. | |
357 | ||
358 | This function also builds sender_rcvhost for use in Received: lines, whose | |
359 | syntax is a bit different. This value also includes the RFC 1413 identity. | |
360 | There wouldn't be two different variables if I had got all this right in the | |
361 | first place. | |
362 | ||
363 | Because this data may survive over more than one incoming SMTP message, it has | |
364 | to be in permanent store. | |
365 | ||
366 | Arguments: none | |
367 | Returns: nothing | |
368 | */ | |
369 | ||
370 | void | |
371 | host_build_sender_fullhost(void) | |
372 | { | |
373 | uschar *address; | |
374 | int old_pool = store_pool; | |
375 | ||
376 | if (sender_host_address == NULL) return; | |
377 | ||
378 | store_pool = POOL_PERM; | |
379 | ||
380 | /* Set up address, with or without the port. After discussion, it seems that | |
381 | the only format that doesn't cause trouble is [aaaa]:pppp. However, we can't | |
382 | use this directly as the first item for Received: because it ain't an RFC 2822 | |
383 | domain. Sigh. */ | |
384 | ||
385 | address = string_sprintf("[%s]:%d", sender_host_address, sender_host_port); | |
386 | if ((log_extra_selector & LX_incoming_port) == 0 || sender_host_port <= 0) | |
387 | *(Ustrrchr(address, ':')) = 0; | |
388 | ||
389 | /* Host name is not verified */ | |
390 | ||
391 | if (sender_host_name == NULL) | |
392 | { | |
393 | uschar *portptr = Ustrstr(address, "]:"); | |
394 | int size = 0; | |
395 | int ptr = 0; | |
396 | int adlen; /* Sun compiler doesn't like ++ in initializers */ | |
397 | ||
398 | adlen = (portptr == NULL)? Ustrlen(address) : (++portptr - address); | |
399 | sender_fullhost = (sender_helo_name == NULL)? address : | |
400 | string_sprintf("(%s) %s", sender_helo_name, address); | |
401 | ||
402 | sender_rcvhost = string_cat(NULL, &size, &ptr, address, adlen); | |
403 | ||
404 | if (sender_ident != NULL || sender_helo_name != NULL || portptr != NULL) | |
405 | { | |
406 | int firstptr; | |
407 | sender_rcvhost = string_cat(sender_rcvhost, &size, &ptr, US" (", 2); | |
408 | firstptr = ptr; | |
409 | ||
410 | if (portptr != NULL) | |
411 | sender_rcvhost = string_append(sender_rcvhost, &size, &ptr, 2, US"port=", | |
412 | portptr + 1); | |
413 | ||
414 | if (sender_helo_name != NULL) | |
415 | sender_rcvhost = string_append(sender_rcvhost, &size, &ptr, 2, | |
416 | (firstptr == ptr)? US"helo=" : US" helo=", sender_helo_name); | |
417 | ||
418 | if (sender_ident != NULL) | |
419 | sender_rcvhost = string_append(sender_rcvhost, &size, &ptr, 2, | |
420 | (firstptr == ptr)? US"ident=" : US" ident=", sender_ident); | |
421 | ||
422 | sender_rcvhost = string_cat(sender_rcvhost, &size, &ptr, US")", 1); | |
423 | } | |
424 | ||
425 | sender_rcvhost[ptr] = 0; /* string_cat() always leaves room */ | |
426 | ||
427 | /* Release store, because string_cat allocated a minimum of 100 bytes that | |
428 | are rarely completely used. */ | |
429 | ||
430 | store_reset(sender_rcvhost + ptr + 1); | |
431 | } | |
432 | ||
433 | /* Host name is known and verified. */ | |
434 | ||
435 | else | |
436 | { | |
437 | int len; | |
5dd9625b PH |
438 | BOOL no_helo = FALSE; |
439 | ||
440 | /* Comparing a HELO name to a host name is easy */ | |
441 | ||
059ec3d9 | 442 | if (sender_helo_name == NULL || |
5dd9625b PH |
443 | strcmpic(sender_host_name, sender_helo_name) == 0) |
444 | no_helo = TRUE; | |
445 | ||
446 | /* If HELO/EHLO was followed by an IP literal, it's much more messy because | |
447 | of two features of IPv6. Firstly, there's the "IPv6:" prefix (Exim is liberal | |
448 | and doesn't require this, for historical reasons). Secondly, an IPv6 address | |
449 | may not be given in canonical form, so we have to canonicize it before | |
450 | comparing. As it happens, the code works for both IPv4 and IPv6. */ | |
451 | ||
452 | else if (sender_helo_name[0] == '[' && | |
453 | sender_helo_name[(len=Ustrlen(sender_helo_name))-1] == ']') | |
454 | { | |
455 | uschar *helo_ip; | |
456 | int offset = 1; | |
457 | ||
458 | if (strncmpic(sender_helo_name+1, US"IPv6:",5) == 0) offset += 5; | |
459 | helo_ip = string_copyn(sender_helo_name + offset, len - offset - 1); | |
460 | ||
461 | if (string_is_ip_address(helo_ip, NULL) != 0) | |
462 | { | |
463 | int x[4]; | |
464 | int size; | |
465 | size = host_aton(helo_ip, x); | |
466 | helo_ip = store_get(48); /* large enough for full IPv6 */ | |
467 | (void)host_nmtoa(size, x, -1, helo_ip, ':'); | |
468 | if (strcmpic(helo_ip, sender_host_address) == 0) no_helo = TRUE; | |
469 | } | |
470 | } | |
471 | ||
472 | if (no_helo) | |
059ec3d9 PH |
473 | { |
474 | sender_fullhost = string_sprintf("%s %s", sender_host_name, address); | |
475 | sender_rcvhost = (sender_ident == NULL)? | |
476 | string_sprintf("%s (%s)", sender_host_name, address) : | |
477 | string_sprintf("%s (%s ident=%s)", sender_host_name, address, | |
478 | sender_ident); | |
479 | } | |
480 | else | |
481 | { | |
482 | sender_fullhost = string_sprintf("%s (%s) %s", sender_host_name, | |
483 | sender_helo_name, address); | |
484 | sender_rcvhost = (sender_ident == NULL)? | |
485 | string_sprintf("%s (%s helo=%s)", sender_host_name, | |
486 | address, sender_helo_name) : | |
487 | string_sprintf("%s\n\t(%s helo=%s ident=%s)", sender_host_name, | |
488 | address, sender_helo_name, sender_ident); | |
489 | } | |
490 | } | |
491 | ||
492 | store_pool = old_pool; | |
493 | ||
494 | DEBUG(D_host_lookup) debug_printf("sender_fullhost = %s\n", sender_fullhost); | |
495 | DEBUG(D_host_lookup) debug_printf("sender_rcvhost = %s\n", sender_rcvhost); | |
496 | } | |
497 | ||
498 | ||
499 | ||
500 | /************************************************* | |
501 | * Build host+ident message * | |
502 | *************************************************/ | |
503 | ||
504 | /* Used when logging rejections and various ACL and SMTP incidents. The text | |
505 | return depends on whether sender_fullhost and sender_ident are set or not: | |
506 | ||
507 | no ident, no host => U=unknown | |
508 | no ident, host set => H=sender_fullhost | |
509 | ident set, no host => U=ident | |
510 | ident set, host set => H=sender_fullhost U=ident | |
511 | ||
512 | Arguments: | |
513 | useflag TRUE if first item to be flagged (H= or U=); if there are two | |
514 | items, the second is always flagged | |
515 | ||
516 | Returns: pointer to a string in big_buffer | |
517 | */ | |
518 | ||
519 | uschar * | |
520 | host_and_ident(BOOL useflag) | |
521 | { | |
522 | if (sender_fullhost == NULL) | |
523 | { | |
524 | (void)string_format(big_buffer, big_buffer_size, "%s%s", useflag? "U=" : "", | |
525 | (sender_ident == NULL)? US"unknown" : sender_ident); | |
526 | } | |
527 | else | |
528 | { | |
529 | uschar *flag = useflag? US"H=" : US""; | |
530 | uschar *iface = US""; | |
531 | if ((log_extra_selector & LX_incoming_interface) != 0 && | |
532 | interface_address != NULL) | |
533 | iface = string_sprintf(" I=[%s]:%d", interface_address, interface_port); | |
534 | if (sender_ident == NULL) | |
535 | (void)string_format(big_buffer, big_buffer_size, "%s%s%s", | |
536 | flag, sender_fullhost, iface); | |
537 | else | |
538 | (void)string_format(big_buffer, big_buffer_size, "%s%s%s U=%s", | |
539 | flag, sender_fullhost, iface, sender_ident); | |
540 | } | |
541 | return big_buffer; | |
542 | } | |
543 | ||
544 | #endif /* STAND_ALONE */ | |
545 | ||
546 | ||
547 | ||
548 | ||
549 | /************************************************* | |
550 | * Build list of local interfaces * | |
551 | *************************************************/ | |
552 | ||
553 | /* This function interprets the contents of the local_interfaces or | |
554 | extra_local_interfaces options, and creates an ip_address_item block for each | |
555 | item on the list. There is no special interpretation of any IP addresses; in | |
556 | particular, 0.0.0.0 and ::0 are returned without modification. If any address | |
557 | includes a port, it is set in the block. Otherwise the port value is set to | |
558 | zero. | |
559 | ||
560 | Arguments: | |
561 | list the list | |
562 | name the name of the option being expanded | |
563 | ||
564 | Returns: a chain of ip_address_items, each containing to a textual | |
565 | version of an IP address, and a port number (host order) or | |
566 | zero if no port was given with the address | |
567 | */ | |
568 | ||
569 | ip_address_item * | |
570 | host_build_ifacelist(uschar *list, uschar *name) | |
571 | { | |
572 | int sep = 0; | |
573 | uschar *s; | |
574 | uschar buffer[64]; | |
575 | ip_address_item *yield = NULL; | |
576 | ip_address_item *last = NULL; | |
577 | ip_address_item *next; | |
578 | ||
579 | while ((s = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) | |
580 | { | |
7cd1141b | 581 | int port = host_address_extract_port(s); /* Leaves just the IP address */ |
a5a28604 | 582 | if (string_is_ip_address(s, NULL) == 0) |
059ec3d9 PH |
583 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Malformed IP address \"%s\" in %s", |
584 | s, name); | |
585 | ||
586 | /* This use of strcpy() is OK because we have checked that s is a valid IP | |
587 | address above. The field in the ip_address_item is large enough to hold an | |
588 | IPv6 address. */ | |
589 | ||
590 | next = store_get(sizeof(ip_address_item)); | |
591 | next->next = NULL; | |
592 | Ustrcpy(next->address, s); | |
593 | next->port = port; | |
594 | next->v6_include_v4 = FALSE; | |
595 | ||
596 | if (yield == NULL) yield = last = next; else | |
597 | { | |
598 | last->next = next; | |
599 | last = next; | |
600 | } | |
601 | } | |
602 | ||
603 | return yield; | |
604 | } | |
605 | ||
606 | ||
607 | ||
608 | ||
609 | ||
610 | /************************************************* | |
611 | * Find addresses on local interfaces * | |
612 | *************************************************/ | |
613 | ||
614 | /* This function finds the addresses of local IP interfaces. These are used | |
615 | when testing for routing to the local host. As the function may be called more | |
616 | than once, the list is preserved in permanent store, pointed to by a static | |
617 | variable, to save doing the work more than once per process. | |
618 | ||
619 | The generic list of interfaces is obtained by calling host_build_ifacelist() | |
620 | for local_interfaces and extra_local_interfaces. This list scanned to remove | |
621 | duplicates (which may exist with different ports - not relevant here). If | |
622 | either of the wildcard IP addresses (0.0.0.0 and ::0) are encountered, they are | |
623 | replaced by the appropriate (IPv4 or IPv6) list of actual local interfaces, | |
624 | obtained from os_find_running_interfaces(). | |
625 | ||
626 | Arguments: none | |
627 | Returns: a chain of ip_address_items, each containing to a textual | |
628 | version of an IP address; the port numbers are not relevant | |
629 | */ | |
630 | ||
631 | ||
632 | /* First, a local subfunction to add an interface to a list in permanent store, | |
633 | but only if there isn't a previous copy of that address on the list. */ | |
634 | ||
635 | static ip_address_item * | |
636 | add_unique_interface(ip_address_item *list, ip_address_item *ipa) | |
637 | { | |
638 | ip_address_item *ipa2; | |
639 | for (ipa2 = list; ipa2 != NULL; ipa2 = ipa2->next) | |
640 | if (Ustrcmp(ipa2->address, ipa->address) == 0) return list; | |
641 | ipa2 = store_get_perm(sizeof(ip_address_item)); | |
642 | *ipa2 = *ipa; | |
643 | ipa2->next = list; | |
644 | return ipa2; | |
645 | } | |
646 | ||
647 | ||
648 | /* This is the globally visible function */ | |
649 | ||
650 | ip_address_item * | |
651 | host_find_interfaces(void) | |
652 | { | |
653 | ip_address_item *running_interfaces = NULL; | |
654 | ||
655 | if (local_interface_data == NULL) | |
656 | { | |
657 | void *reset_item = store_get(0); | |
658 | ip_address_item *dlist = host_build_ifacelist(local_interfaces, | |
659 | US"local_interfaces"); | |
660 | ip_address_item *xlist = host_build_ifacelist(extra_local_interfaces, | |
661 | US"extra_local_interfaces"); | |
662 | ip_address_item *ipa; | |
663 | ||
664 | if (dlist == NULL) dlist = xlist; else | |
665 | { | |
666 | for (ipa = dlist; ipa->next != NULL; ipa = ipa->next); | |
667 | ipa->next = xlist; | |
668 | } | |
669 | ||
670 | for (ipa = dlist; ipa != NULL; ipa = ipa->next) | |
671 | { | |
672 | if (Ustrcmp(ipa->address, "0.0.0.0") == 0 || | |
673 | Ustrcmp(ipa->address, "::0") == 0) | |
674 | { | |
675 | ip_address_item *ipa2; | |
676 | BOOL ipv6 = ipa->address[0] == ':'; | |
677 | if (running_interfaces == NULL) | |
678 | running_interfaces = os_find_running_interfaces(); | |
679 | for (ipa2 = running_interfaces; ipa2 != NULL; ipa2 = ipa2->next) | |
680 | { | |
681 | if ((Ustrchr(ipa2->address, ':') != NULL) == ipv6) | |
682 | local_interface_data = add_unique_interface(local_interface_data, | |
683 | ipa2); | |
684 | } | |
685 | } | |
686 | else | |
687 | { | |
688 | local_interface_data = add_unique_interface(local_interface_data, ipa); | |
689 | DEBUG(D_interface) | |
690 | { | |
691 | debug_printf("Configured local interface: address=%s", ipa->address); | |
692 | if (ipa->port != 0) debug_printf(" port=%d", ipa->port); | |
693 | debug_printf("\n"); | |
694 | } | |
695 | } | |
696 | } | |
697 | store_reset(reset_item); | |
698 | } | |
699 | ||
700 | return local_interface_data; | |
701 | } | |
702 | ||
703 | ||
704 | ||
705 | ||
706 | ||
707 | /************************************************* | |
708 | * Convert network IP address to text * | |
709 | *************************************************/ | |
710 | ||
711 | /* Given an IPv4 or IPv6 address in binary, convert it to a text | |
712 | string and return the result in a piece of new store. The address can | |
713 | either be given directly, or passed over in a sockaddr structure. Note | |
714 | that this isn't the converse of host_aton() because of byte ordering | |
715 | differences. See host_nmtoa() below. | |
716 | ||
717 | Arguments: | |
718 | type if < 0 then arg points to a sockaddr, else | |
719 | either AF_INET or AF_INET6 | |
720 | arg points to a sockaddr if type is < 0, or | |
721 | points to an IPv4 address (32 bits), or | |
722 | points to an IPv6 address (128 bits), | |
723 | in both cases, in network byte order | |
724 | buffer if NULL, the result is returned in gotten store; | |
725 | else points to a buffer to hold the answer | |
726 | portptr points to where to put the port number, if non NULL; only | |
727 | used when type < 0 | |
728 | ||
729 | Returns: pointer to character string | |
730 | */ | |
731 | ||
732 | uschar * | |
733 | host_ntoa(int type, const void *arg, uschar *buffer, int *portptr) | |
734 | { | |
735 | uschar *yield; | |
736 | ||
737 | /* The new world. It is annoying that we have to fish out the address from | |
738 | different places in the block, depending on what kind of address it is. It | |
739 | is also a pain that inet_ntop() returns a const uschar *, whereas the IPv4 | |
740 | function inet_ntoa() returns just uschar *, and some picky compilers insist | |
741 | on warning if one assigns a const uschar * to a uschar *. Hence the casts. */ | |
742 | ||
743 | #if HAVE_IPV6 | |
744 | uschar addr_buffer[46]; | |
745 | if (type < 0) | |
746 | { | |
747 | int family = ((struct sockaddr *)arg)->sa_family; | |
748 | if (family == AF_INET6) | |
749 | { | |
750 | struct sockaddr_in6 *sk = (struct sockaddr_in6 *)arg; | |
751 | yield = (uschar *)inet_ntop(family, &(sk->sin6_addr), CS addr_buffer, | |
752 | sizeof(addr_buffer)); | |
753 | if (portptr != NULL) *portptr = ntohs(sk->sin6_port); | |
754 | } | |
755 | else | |
756 | { | |
757 | struct sockaddr_in *sk = (struct sockaddr_in *)arg; | |
758 | yield = (uschar *)inet_ntop(family, &(sk->sin_addr), CS addr_buffer, | |
759 | sizeof(addr_buffer)); | |
760 | if (portptr != NULL) *portptr = ntohs(sk->sin_port); | |
761 | } | |
762 | } | |
763 | else | |
764 | { | |
765 | yield = (uschar *)inet_ntop(type, arg, CS addr_buffer, sizeof(addr_buffer)); | |
766 | } | |
767 | ||
768 | /* If the result is a mapped IPv4 address, show it in V4 format. */ | |
769 | ||
770 | if (Ustrncmp(yield, "::ffff:", 7) == 0) yield += 7; | |
771 | ||
772 | #else /* HAVE_IPV6 */ | |
773 | ||
774 | /* The old world */ | |
775 | ||
776 | if (type < 0) | |
777 | { | |
778 | yield = US inet_ntoa(((struct sockaddr_in *)arg)->sin_addr); | |
779 | if (portptr != NULL) *portptr = ntohs(((struct sockaddr_in *)arg)->sin_port); | |
780 | } | |
781 | else | |
782 | yield = US inet_ntoa(*((struct in_addr *)arg)); | |
783 | #endif | |
784 | ||
785 | /* If there is no buffer, put the string into some new store. */ | |
786 | ||
787 | if (buffer == NULL) return string_copy(yield); | |
788 | ||
789 | /* Callers of this function with a non-NULL buffer must ensure that it is | |
790 | large enough to hold an IPv6 address, namely, at least 46 bytes. That's what | |
791 | makes this use of strcpy() OK. */ | |
792 | ||
793 | Ustrcpy(buffer, yield); | |
794 | return buffer; | |
795 | } | |
796 | ||
797 | ||
798 | ||
799 | ||
800 | /************************************************* | |
801 | * Convert address text to binary * | |
802 | *************************************************/ | |
803 | ||
804 | /* Given the textual form of an IP address, convert it to binary in an | |
805 | array of ints. IPv4 addresses occupy one int; IPv6 addresses occupy 4 ints. | |
806 | The result has the first byte in the most significant byte of the first int. In | |
807 | other words, the result is not in network byte order, but in host byte order. | |
808 | As a result, this is not the converse of host_ntoa(), which expects network | |
809 | byte order. See host_nmtoa() below. | |
810 | ||
811 | Arguments: | |
812 | address points to the textual address, checked for syntax | |
813 | bin points to an array of 4 ints | |
814 | ||
815 | Returns: the number of ints used | |
816 | */ | |
817 | ||
818 | int | |
819 | host_aton(uschar *address, int *bin) | |
820 | { | |
821 | int x[4]; | |
822 | int v4offset = 0; | |
823 | ||
8e669ac1 | 824 | /* Handle IPv6 address, which may end with an IPv4 address. It may also end |
7e634d24 PH |
825 | with a "scope", introduced by a percent sign. This code is NOT enclosed in #if |
826 | HAVE_IPV6 in order that IPv6 addresses are recognized even if IPv6 is not | |
827 | supported. */ | |
059ec3d9 PH |
828 | |
829 | if (Ustrchr(address, ':') != NULL) | |
830 | { | |
831 | uschar *p = address; | |
832 | uschar *component[8]; | |
833 | BOOL ipv4_ends = FALSE; | |
834 | int ci = 0; | |
835 | int nulloffset = 0; | |
836 | int v6count = 8; | |
837 | int i; | |
838 | ||
839 | /* If the address starts with a colon, it will start with two colons. | |
840 | Just lose the first one, which will leave a null first component. */ | |
8e669ac1 | 841 | |
059ec3d9 PH |
842 | if (*p == ':') p++; |
843 | ||
8e669ac1 PH |
844 | /* Split the address into components separated by colons. The input address |
845 | is supposed to be checked for syntax. There was a case where this was | |
846 | overlooked; to guard against that happening again, check here and crash if | |
7e634d24 | 847 | there are too many components. */ |
059ec3d9 | 848 | |
7e634d24 | 849 | while (*p != 0 && *p != '%') |
059ec3d9 | 850 | { |
7e634d24 | 851 | int len = Ustrcspn(p, ":%"); |
059ec3d9 | 852 | if (len == 0) nulloffset = ci; |
8e669ac1 | 853 | if (ci > 7) log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
b975ba52 | 854 | "Internal error: invalid IPv6 address \"%s\" passed to host_aton()", |
8e669ac1 | 855 | address); |
059ec3d9 PH |
856 | component[ci++] = p; |
857 | p += len; | |
858 | if (*p == ':') p++; | |
859 | } | |
860 | ||
861 | /* If the final component contains a dot, it is a trailing v4 address. | |
862 | As the syntax is known to be checked, just set up for a trailing | |
863 | v4 address and restrict the v6 part to 6 components. */ | |
864 | ||
865 | if (Ustrchr(component[ci-1], '.') != NULL) | |
866 | { | |
867 | address = component[--ci]; | |
868 | ipv4_ends = TRUE; | |
869 | v4offset = 3; | |
870 | v6count = 6; | |
871 | } | |
872 | ||
873 | /* If there are fewer than 6 or 8 components, we have to insert some | |
874 | more empty ones in the middle. */ | |
875 | ||
876 | if (ci < v6count) | |
877 | { | |
878 | int insert_count = v6count - ci; | |
879 | for (i = v6count-1; i > nulloffset + insert_count; i--) | |
880 | component[i] = component[i - insert_count]; | |
881 | while (i > nulloffset) component[i--] = US""; | |
882 | } | |
883 | ||
884 | /* Now turn the components into binary in pairs and bung them | |
885 | into the vector of ints. */ | |
886 | ||
887 | for (i = 0; i < v6count; i += 2) | |
888 | bin[i/2] = (Ustrtol(component[i], NULL, 16) << 16) + | |
889 | Ustrtol(component[i+1], NULL, 16); | |
890 | ||
891 | /* If there was no terminating v4 component, we are done. */ | |
892 | ||
893 | if (!ipv4_ends) return 4; | |
894 | } | |
895 | ||
896 | /* Handle IPv4 address */ | |
897 | ||
ff790e47 | 898 | (void)sscanf(CS address, "%d.%d.%d.%d", x, x+1, x+2, x+3); |
059ec3d9 PH |
899 | bin[v4offset] = (x[0] << 24) + (x[1] << 16) + (x[2] << 8) + x[3]; |
900 | return v4offset+1; | |
901 | } | |
902 | ||
903 | ||
904 | /************************************************* | |
905 | * Apply mask to an IP address * | |
906 | *************************************************/ | |
907 | ||
908 | /* Mask an address held in 1 or 4 ints, with the ms bit in the ms bit of the | |
909 | first int, etc. | |
910 | ||
911 | Arguments: | |
912 | count the number of ints | |
913 | binary points to the ints to be masked | |
914 | mask the count of ms bits to leave, or -1 if no masking | |
915 | ||
916 | Returns: nothing | |
917 | */ | |
918 | ||
919 | void | |
920 | host_mask(int count, int *binary, int mask) | |
921 | { | |
922 | int i; | |
923 | if (mask < 0) mask = 99999; | |
924 | for (i = 0; i < count; i++) | |
925 | { | |
926 | int wordmask; | |
927 | if (mask == 0) wordmask = 0; | |
928 | else if (mask < 32) | |
929 | { | |
930 | wordmask = (-1) << (32 - mask); | |
931 | mask = 0; | |
932 | } | |
933 | else | |
934 | { | |
935 | wordmask = -1; | |
936 | mask -= 32; | |
937 | } | |
938 | binary[i] &= wordmask; | |
939 | } | |
940 | } | |
941 | ||
942 | ||
943 | ||
944 | ||
945 | /************************************************* | |
946 | * Convert masked IP address in ints to text * | |
947 | *************************************************/ | |
948 | ||
949 | /* We can't use host_ntoa() because it assumes the binary values are in network | |
950 | byte order, and these are the result of host_aton(), which puts them in ints in | |
951 | host byte order. Also, we really want IPv6 addresses to be in a canonical | |
6f0c9a4f PH |
952 | format, so we output them with no abbreviation. In a number of cases we can't |
953 | use the normal colon separator in them because it terminates keys in lsearch | |
8e669ac1 | 954 | files, so we want to use dot instead. There's an argument that specifies what |
6f0c9a4f | 955 | to use for IPv6 addresses. |
059ec3d9 PH |
956 | |
957 | Arguments: | |
958 | count 1 or 4 (number of ints) | |
959 | binary points to the ints | |
960 | mask mask value; if < 0 don't add to result | |
961 | buffer big enough to hold the result | |
8e669ac1 | 962 | sep component separator character for IPv6 addresses |
059ec3d9 PH |
963 | |
964 | Returns: the number of characters placed in buffer, not counting | |
965 | the final nul. | |
966 | */ | |
967 | ||
968 | int | |
6f0c9a4f | 969 | host_nmtoa(int count, int *binary, int mask, uschar *buffer, int sep) |
059ec3d9 PH |
970 | { |
971 | int i, j; | |
972 | uschar *tt = buffer; | |
973 | ||
974 | if (count == 1) | |
975 | { | |
976 | j = binary[0]; | |
977 | for (i = 24; i >= 0; i -= 8) | |
978 | { | |
979 | sprintf(CS tt, "%d.", (j >> i) & 255); | |
980 | while (*tt) tt++; | |
981 | } | |
982 | } | |
983 | else | |
984 | { | |
985 | for (i = 0; i < 4; i++) | |
986 | { | |
987 | j = binary[i]; | |
6f0c9a4f | 988 | sprintf(CS tt, "%04x%c%04x%c", (j >> 16) & 0xffff, sep, j & 0xffff, sep); |
059ec3d9 PH |
989 | while (*tt) tt++; |
990 | } | |
991 | } | |
992 | ||
6f0c9a4f | 993 | tt--; /* lose final separator */ |
059ec3d9 PH |
994 | |
995 | if (mask < 0) | |
996 | *tt = 0; | |
997 | else | |
998 | { | |
999 | sprintf(CS tt, "/%d", mask); | |
1000 | while (*tt) tt++; | |
1001 | } | |
1002 | ||
1003 | return tt - buffer; | |
1004 | } | |
1005 | ||
1006 | ||
1007 | ||
1008 | /************************************************* | |
1009 | * Check port for tls_on_connect * | |
1010 | *************************************************/ | |
1011 | ||
1012 | /* This function checks whether a given incoming port is configured for tls- | |
1013 | on-connect. It is called from the daemon and from inetd handling. If the global | |
1014 | option tls_on_connect is already set, all ports operate this way. Otherwise, we | |
1015 | check the tls_on_connect_ports option for a list of ports. | |
1016 | ||
1017 | Argument: a port number | |
1018 | Returns: TRUE or FALSE | |
1019 | */ | |
1020 | ||
1021 | BOOL | |
1022 | host_is_tls_on_connect_port(int port) | |
1023 | { | |
1024 | int sep = 0; | |
1025 | uschar buffer[32]; | |
1026 | uschar *list = tls_on_connect_ports; | |
1027 | uschar *s; | |
1028 | ||
1029 | if (tls_on_connect) return TRUE; | |
1030 | ||
1031 | while ((s = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL) | |
1032 | { | |
1033 | uschar *end; | |
1034 | int lport = Ustrtol(s, &end, 10); | |
1035 | if (*end != 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "tls_on_connect_ports " | |
1036 | "contains \"%s\", which is not a port number: exim abandoned", s); | |
1037 | if (lport == port) return TRUE; | |
1038 | } | |
1039 | ||
1040 | return FALSE; | |
1041 | } | |
1042 | ||
1043 | ||
1044 | ||
1045 | /************************************************* | |
1046 | * Check whether host is in a network * | |
1047 | *************************************************/ | |
1048 | ||
1049 | /* This function checks whether a given IP address matches a pattern that | |
1050 | represents either a single host, or a network (using CIDR notation). The caller | |
1051 | of this function must check the syntax of the arguments before calling it. | |
1052 | ||
1053 | Arguments: | |
1054 | host string representation of the ip-address to check | |
1055 | net string representation of the network, with optional CIDR mask | |
1056 | maskoffset offset to the / that introduces the mask in the key | |
1057 | zero if there is no mask | |
1058 | ||
1059 | Returns: | |
1060 | TRUE the host is inside the network | |
1061 | FALSE the host is NOT inside the network | |
1062 | */ | |
1063 | ||
1064 | BOOL | |
1065 | host_is_in_net(uschar *host, uschar *net, int maskoffset) | |
1066 | { | |
1067 | int i; | |
1068 | int address[4]; | |
1069 | int incoming[4]; | |
1070 | int mlen; | |
1071 | int size = host_aton(net, address); | |
1072 | int insize; | |
1073 | ||
1074 | /* No mask => all bits to be checked */ | |
1075 | ||
1076 | if (maskoffset == 0) mlen = 99999; /* Big number */ | |
1077 | else mlen = Uatoi(net + maskoffset + 1); | |
1078 | ||
1079 | /* Convert the incoming address to binary. */ | |
1080 | ||
1081 | insize = host_aton(host, incoming); | |
1082 | ||
1083 | /* Convert IPv4 addresses given in IPv6 compatible mode, which represent | |
1084 | connections from IPv4 hosts to IPv6 hosts, that is, addresses of the form | |
1085 | ::ffff:<v4address>, to IPv4 format. */ | |
1086 | ||
1087 | if (insize == 4 && incoming[0] == 0 && incoming[1] == 0 && | |
1088 | incoming[2] == 0xffff) | |
1089 | { | |
1090 | insize = 1; | |
1091 | incoming[0] = incoming[3]; | |
1092 | } | |
1093 | ||
1094 | /* No match if the sizes don't agree. */ | |
1095 | ||
1096 | if (insize != size) return FALSE; | |
1097 | ||
1098 | /* Else do the masked comparison. */ | |
1099 | ||
1100 | for (i = 0; i < size; i++) | |
1101 | { | |
1102 | int mask; | |
1103 | if (mlen == 0) mask = 0; | |
1104 | else if (mlen < 32) | |
1105 | { | |
1106 | mask = (-1) << (32 - mlen); | |
1107 | mlen = 0; | |
1108 | } | |
1109 | else | |
1110 | { | |
1111 | mask = -1; | |
1112 | mlen -= 32; | |
1113 | } | |
1114 | if ((incoming[i] & mask) != (address[i] & mask)) return FALSE; | |
1115 | } | |
1116 | ||
1117 | return TRUE; | |
1118 | } | |
1119 | ||
1120 | ||
1121 | ||
1122 | /************************************************* | |
1123 | * Scan host list for local hosts * | |
1124 | *************************************************/ | |
1125 | ||
1126 | /* Scan through a chain of addresses and check whether any of them is the | |
1127 | address of an interface on the local machine. If so, remove that address and | |
1128 | any previous ones with the same MX value, and all subsequent ones (which will | |
1129 | have greater or equal MX values) from the chain. Note: marking them as unusable | |
1130 | is NOT the right thing to do because it causes the hosts not to be used for | |
1131 | other domains, for which they may well be correct. | |
1132 | ||
1133 | The hosts may be part of a longer chain; we only process those between the | |
1134 | initial pointer and the "last" pointer. | |
1135 | ||
1136 | There is also a list of "pseudo-local" host names which are checked against the | |
1137 | host names. Any match causes that host item to be treated the same as one which | |
1138 | matches a local IP address. | |
1139 | ||
1140 | If the very first host is a local host, then all MX records had a precedence | |
1141 | greater than or equal to that of the local host. Either there's a problem in | |
1142 | the DNS, or an apparently remote name turned out to be an abbreviation for the | |
1143 | local host. Give a specific return code, and let the caller decide what to do. | |
1144 | Otherwise, give a success code if at least one host address has been found. | |
1145 | ||
1146 | Arguments: | |
1147 | host pointer to the first host in the chain | |
1148 | lastptr pointer to pointer to the last host in the chain (may be updated) | |
1149 | removed if not NULL, set TRUE if some local addresses were removed | |
1150 | from the list | |
1151 | ||
1152 | Returns: | |
1153 | HOST_FOUND if there is at least one host with an IP address on the chain | |
1154 | and an MX value less than any MX value associated with the | |
1155 | local host | |
1156 | HOST_FOUND_LOCAL if a local host is among the lowest-numbered MX hosts; when | |
1157 | the host addresses were obtained from A records or | |
1158 | gethostbyname(), the MX values are set to -1. | |
1159 | HOST_FIND_FAILED if no valid hosts with set IP addresses were found | |
1160 | */ | |
1161 | ||
1162 | int | |
1163 | host_scan_for_local_hosts(host_item *host, host_item **lastptr, BOOL *removed) | |
1164 | { | |
1165 | int yield = HOST_FIND_FAILED; | |
1166 | host_item *last = *lastptr; | |
1167 | host_item *prev = NULL; | |
1168 | host_item *h; | |
1169 | ||
1170 | if (removed != NULL) *removed = FALSE; | |
1171 | ||
1172 | if (local_interface_data == NULL) local_interface_data = host_find_interfaces(); | |
1173 | ||
1174 | for (h = host; h != last->next; h = h->next) | |
1175 | { | |
1176 | #ifndef STAND_ALONE | |
1177 | if (hosts_treat_as_local != NULL) | |
1178 | { | |
1179 | int rc; | |
1180 | uschar *save = deliver_domain; | |
1181 | deliver_domain = h->name; /* set $domain */ | |
1182 | rc = match_isinlist(string_copylc(h->name), &hosts_treat_as_local, 0, | |
1183 | &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL); | |
1184 | deliver_domain = save; | |
1185 | if (rc == OK) goto FOUND_LOCAL; | |
1186 | } | |
1187 | #endif | |
1188 | ||
1189 | /* It seems that on many operating systems, 0.0.0.0 is treated as a synonym | |
1190 | for 127.0.0.1 and refers to the local host. We therefore force it always to | |
1191 | be treated as local. */ | |
1192 | ||
1193 | if (h->address != NULL) | |
1194 | { | |
1195 | ip_address_item *ip; | |
1196 | if (Ustrcmp(h->address, "0.0.0.0") == 0) goto FOUND_LOCAL; | |
1197 | for (ip = local_interface_data; ip != NULL; ip = ip->next) | |
1198 | if (Ustrcmp(h->address, ip->address) == 0) goto FOUND_LOCAL; | |
1199 | yield = HOST_FOUND; /* At least one remote address has been found */ | |
1200 | } | |
1201 | ||
1202 | /* Update prev to point to the last host item before any that have | |
1203 | the same MX value as the one we have just considered. */ | |
1204 | ||
1205 | if (h->next == NULL || h->next->mx != h->mx) prev = h; | |
1206 | } | |
1207 | ||
1208 | return yield; /* No local hosts found: return HOST_FOUND or HOST_FIND_FAILED */ | |
1209 | ||
1210 | /* A host whose IP address matches a local IP address, or whose name matches | |
1211 | something in hosts_treat_as_local has been found. */ | |
1212 | ||
1213 | FOUND_LOCAL: | |
1214 | ||
1215 | if (prev == NULL) | |
1216 | { | |
1217 | HDEBUG(D_host_lookup) debug_printf((h->mx >= 0)? | |
1218 | "local host has lowest MX\n" : | |
1219 | "local host found for non-MX address\n"); | |
1220 | return HOST_FOUND_LOCAL; | |
1221 | } | |
1222 | ||
1223 | HDEBUG(D_host_lookup) | |
1224 | { | |
1225 | debug_printf("local host in host list - removed hosts:\n"); | |
1226 | for (h = prev->next; h != last->next; h = h->next) | |
1227 | debug_printf(" %s %s %d\n", h->name, h->address, h->mx); | |
1228 | } | |
1229 | ||
1230 | if (removed != NULL) *removed = TRUE; | |
1231 | prev->next = last->next; | |
1232 | *lastptr = prev; | |
1233 | return yield; | |
1234 | } | |
1235 | ||
1236 | ||
1237 | ||
1238 | ||
1239 | /************************************************* | |
1240 | * Remove duplicate IPs in host list * | |
1241 | *************************************************/ | |
1242 | ||
1243 | /* You would think that administrators could set up their DNS records so that | |
1244 | one ended up with a list of unique IP addresses after looking up A or MX | |
1245 | records, but apparently duplication is common. So we scan such lists and | |
1246 | remove the later duplicates. Note that we may get lists in which some host | |
1247 | addresses are not set. | |
1248 | ||
1249 | Arguments: | |
1250 | host pointer to the first host in the chain | |
1251 | lastptr pointer to pointer to the last host in the chain (may be updated) | |
1252 | ||
1253 | Returns: nothing | |
1254 | */ | |
1255 | ||
1256 | static void | |
1257 | host_remove_duplicates(host_item *host, host_item **lastptr) | |
1258 | { | |
1259 | while (host != *lastptr) | |
1260 | { | |
1261 | if (host->address != NULL) | |
1262 | { | |
1263 | host_item *h = host; | |
1264 | while (h != *lastptr) | |
1265 | { | |
1266 | if (h->next->address != NULL && | |
1267 | Ustrcmp(h->next->address, host->address) == 0) | |
1268 | { | |
1269 | DEBUG(D_host_lookup) debug_printf("duplicate IP address %s (MX=%d) " | |
1270 | "removed\n", host->address, h->next->mx); | |
1271 | if (h->next == *lastptr) *lastptr = h; | |
1272 | h->next = h->next->next; | |
1273 | } | |
1274 | else h = h->next; | |
1275 | } | |
1276 | } | |
1277 | /* If the last item was removed, host may have become == *lastptr */ | |
1278 | if (host != *lastptr) host = host->next; | |
1279 | } | |
1280 | } | |
1281 | ||
1282 | ||
1283 | ||
1284 | ||
1285 | /************************************************* | |
1286 | * Find sender host name by gethostbyaddr() * | |
1287 | *************************************************/ | |
1288 | ||
1289 | /* This used to be the only way it was done, but it turns out that not all | |
1290 | systems give aliases for calls to gethostbyaddr() - or one of the modern | |
1291 | equivalents like getipnodebyaddr(). Fortunately, multiple PTR records are rare, | |
1292 | but they can still exist. This function is now used only when a DNS lookup of | |
1293 | the IP address fails, in order to give access to /etc/hosts. | |
1294 | ||
1295 | Arguments: none | |
1296 | Returns: OK, DEFER, FAIL | |
1297 | */ | |
1298 | ||
1299 | static int | |
1300 | host_name_lookup_byaddr(void) | |
1301 | { | |
1302 | int len; | |
1303 | uschar *s, *t; | |
1304 | struct hostent *hosts; | |
1305 | struct in_addr addr; | |
1306 | ||
1307 | /* Lookup on IPv6 system */ | |
1308 | ||
1309 | #if HAVE_IPV6 | |
1310 | if (Ustrchr(sender_host_address, ':') != NULL) | |
1311 | { | |
1312 | struct in6_addr addr6; | |
1313 | if (inet_pton(AF_INET6, CS sender_host_address, &addr6) != 1) | |
1314 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an " | |
1315 | "IPv6 address", sender_host_address); | |
1316 | #if HAVE_GETIPNODEBYADDR | |
1317 | hosts = getipnodebyaddr(CS &addr6, sizeof(addr6), AF_INET6, &h_errno); | |
1318 | #else | |
1319 | hosts = gethostbyaddr(CS &addr6, sizeof(addr6), AF_INET6); | |
1320 | #endif | |
1321 | } | |
1322 | else | |
1323 | { | |
1324 | if (inet_pton(AF_INET, CS sender_host_address, &addr) != 1) | |
1325 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an " | |
1326 | "IPv4 address", sender_host_address); | |
1327 | #if HAVE_GETIPNODEBYADDR | |
1328 | hosts = getipnodebyaddr(CS &addr, sizeof(addr), AF_INET, &h_errno); | |
1329 | #else | |
1330 | hosts = gethostbyaddr(CS &addr, sizeof(addr), AF_INET); | |
1331 | #endif | |
1332 | } | |
1333 | ||
1334 | /* Do lookup on IPv4 system */ | |
1335 | ||
1336 | #else | |
1337 | addr.s_addr = (S_ADDR_TYPE)inet_addr(CS sender_host_address); | |
1338 | hosts = gethostbyaddr(CS(&addr), sizeof(addr), AF_INET); | |
1339 | #endif | |
1340 | ||
1341 | /* Failed to look up the host. */ | |
1342 | ||
1343 | if (hosts == NULL) | |
1344 | { | |
1345 | HDEBUG(D_host_lookup) debug_printf("IP address lookup failed: h_errno=%d\n", | |
1346 | h_errno); | |
1347 | return (h_errno == TRY_AGAIN || h_errno == NO_RECOVERY) ? DEFER : FAIL; | |
1348 | } | |
1349 | ||
1350 | /* It seems there are some records in the DNS that yield an empty name. We | |
1351 | treat this as non-existent. In some operating systems, this is returned as an | |
1352 | empty string; in others as a single dot. */ | |
1353 | ||
1354 | if (hosts->h_name[0] == 0 || hosts->h_name[0] == '.') | |
1355 | { | |
1356 | HDEBUG(D_host_lookup) debug_printf("IP address lookup yielded an empty name: " | |
1357 | "treated as non-existent host name\n"); | |
1358 | return FAIL; | |
1359 | } | |
1360 | ||
1361 | /* Copy and lowercase the name, which is in static storage in many systems. | |
1362 | Put it in permanent memory. */ | |
1363 | ||
1364 | s = (uschar *)hosts->h_name; | |
1365 | len = Ustrlen(s) + 1; | |
1366 | t = sender_host_name = store_get_perm(len); | |
1367 | while (*s != 0) *t++ = tolower(*s++); | |
1368 | *t = 0; | |
1369 | ||
1370 | /* If the host has aliases, build a copy of the alias list */ | |
1371 | ||
1372 | if (hosts->h_aliases != NULL) | |
1373 | { | |
1374 | int count = 1; | |
1375 | uschar **aliases, **ptr; | |
1376 | for (aliases = USS hosts->h_aliases; *aliases != NULL; aliases++) count++; | |
1377 | ptr = sender_host_aliases = store_get_perm(count * sizeof(uschar *)); | |
1378 | for (aliases = USS hosts->h_aliases; *aliases != NULL; aliases++) | |
1379 | { | |
1380 | uschar *s = *aliases; | |
1381 | int len = Ustrlen(s) + 1; | |
1382 | uschar *t = *ptr++ = store_get_perm(len); | |
1383 | while (*s != 0) *t++ = tolower(*s++); | |
1384 | *t = 0; | |
1385 | } | |
1386 | *ptr = NULL; | |
1387 | } | |
1388 | ||
1389 | return OK; | |
1390 | } | |
1391 | ||
1392 | ||
1393 | ||
1394 | /************************************************* | |
1395 | * Find host name for incoming call * | |
1396 | *************************************************/ | |
1397 | ||
1398 | /* Put the name in permanent store, pointed to by sender_host_name. We also set | |
1399 | up a list of alias names, pointed to by sender_host_alias. The list is | |
1400 | NULL-terminated. The incoming address is in sender_host_address, either in | |
1401 | dotted-quad form for IPv4 or in colon-separated form for IPv6. | |
1402 | ||
1403 | This function does a thorough check that the names it finds point back to the | |
1404 | incoming IP address. Any that do not are discarded. Note that this is relied on | |
1405 | by the ACL reverse_host_lookup check. | |
1406 | ||
1407 | On some systems, get{host,ipnode}byaddr() appears to do this internally, but | |
1408 | this it not universally true. Also, for release 4.30, this function was changed | |
1409 | to do a direct DNS lookup first, by default[1], because it turns out that that | |
1410 | is the only guaranteed way to find all the aliases on some systems. My | |
1411 | experiments indicate that Solaris gethostbyaddr() gives the aliases for but | |
1412 | Linux does not. | |
1413 | ||
1414 | [1] The actual order is controlled by the host_lookup_order option. | |
1415 | ||
1416 | Arguments: none | |
1417 | Returns: OK on success, the answer being placed in the global variable | |
1418 | sender_host_name, with any aliases in a list hung off | |
1419 | sender_host_aliases | |
1420 | FAIL if no host name can be found | |
1421 | DEFER if a temporary error was encountered | |
1422 | ||
1423 | The variable host_lookup_msg is set to an empty string on sucess, or to a | |
1424 | reason for the failure otherwise, in a form suitable for tagging onto an error | |
8e669ac1 | 1425 | message, and also host_lookup_failed is set TRUE if the lookup failed. If there |
b08b24c8 PH |
1426 | was a defer, host_lookup_deferred is set TRUE. |
1427 | ||
1428 | Any dynamically constructed string for host_lookup_msg must be in permanent | |
1429 | store, because it might be used for several incoming messages on the same SMTP | |
059ec3d9 PH |
1430 | connection. */ |
1431 | ||
1432 | int | |
1433 | host_name_lookup(void) | |
1434 | { | |
1435 | int old_pool, rc; | |
1436 | int sep = 0; | |
1437 | uschar *hname, *save_hostname; | |
1438 | uschar **aliases; | |
1439 | uschar buffer[256]; | |
1440 | uschar *ordername; | |
1441 | uschar *list = host_lookup_order; | |
1442 | dns_record *rr; | |
1443 | dns_answer dnsa; | |
1444 | dns_scan dnss; | |
1445 | ||
b08b24c8 PH |
1446 | host_lookup_deferred = host_lookup_failed = FALSE; |
1447 | ||
059ec3d9 PH |
1448 | HDEBUG(D_host_lookup) |
1449 | debug_printf("looking up host name for %s\n", sender_host_address); | |
1450 | ||
1451 | /* For testing the case when a lookup does not complete, we have a special | |
1452 | reserved IP address. */ | |
1453 | ||
1454 | if (running_in_test_harness && | |
1455 | Ustrcmp(sender_host_address, "99.99.99.99") == 0) | |
1456 | { | |
1457 | HDEBUG(D_host_lookup) | |
1458 | debug_printf("Test harness: host name lookup returns DEFER\n"); | |
8e669ac1 | 1459 | host_lookup_deferred = TRUE; |
059ec3d9 PH |
1460 | return DEFER; |
1461 | } | |
1462 | ||
1463 | /* Do lookups directly in the DNS or via gethostbyaddr() (or equivalent), in | |
1464 | the order specified by the host_lookup_order option. */ | |
1465 | ||
1466 | while ((ordername = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) | |
1467 | != NULL) | |
1468 | { | |
1469 | if (strcmpic(ordername, US"bydns") == 0) | |
1470 | { | |
1471 | dns_init(FALSE, FALSE); | |
1472 | dns_build_reverse(sender_host_address, buffer); | |
1473 | rc = dns_lookup(&dnsa, buffer, T_PTR, NULL); | |
1474 | ||
1475 | /* The first record we come across is used for the name; others are | |
1476 | considered to be aliases. We have to scan twice, in order to find out the | |
1477 | number of aliases. However, if all the names are empty, we will behave as | |
1478 | if failure. (PTR records that yield empty names have been encountered in | |
1479 | the DNS.) */ | |
1480 | ||
1481 | if (rc == DNS_SUCCEED) | |
1482 | { | |
1483 | uschar **aptr = NULL; | |
1484 | int ssize = 264; | |
1485 | int count = 0; | |
1486 | int old_pool = store_pool; | |
1487 | ||
1488 | store_pool = POOL_PERM; /* Save names in permanent storage */ | |
1489 | ||
1490 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
1491 | rr != NULL; | |
1492 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
1493 | { | |
1494 | if (rr->type == T_PTR) count++; | |
1495 | } | |
1496 | ||
1497 | /* Get store for the list of aliases. For compatibility with | |
1498 | gethostbyaddr, we make an empty list if there are none. */ | |
1499 | ||
1500 | aptr = sender_host_aliases = store_get(count * sizeof(uschar *)); | |
1501 | ||
1502 | /* Re-scan and extract the names */ | |
1503 | ||
1504 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
1505 | rr != NULL; | |
1506 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
1507 | { | |
1508 | uschar *s = NULL; | |
1509 | if (rr->type != T_PTR) continue; | |
1510 | s = store_get(ssize); | |
1511 | ||
1512 | /* If an overlong response was received, the data will have been | |
1513 | truncated and dn_expand may fail. */ | |
1514 | ||
1515 | if (dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, | |
1516 | (uschar *)(rr->data), (DN_EXPAND_ARG4_TYPE)(s), ssize) < 0) | |
1517 | { | |
1518 | log_write(0, LOG_MAIN, "host name alias list truncated for %s", | |
1519 | sender_host_address); | |
1520 | break; | |
1521 | } | |
1522 | ||
1523 | store_reset(s + Ustrlen(s) + 1); | |
1524 | if (s[0] == 0) | |
1525 | { | |
1526 | HDEBUG(D_host_lookup) debug_printf("IP address lookup yielded an " | |
1527 | "empty name: treated as non-existent host name\n"); | |
1528 | continue; | |
1529 | } | |
1530 | if (sender_host_name == NULL) sender_host_name = s; | |
1531 | else *aptr++ = s; | |
1532 | while (*s != 0) { *s = tolower(*s); s++; } | |
1533 | } | |
1534 | ||
1535 | *aptr = NULL; /* End of alias list */ | |
1536 | store_pool = old_pool; /* Reset store pool */ | |
1537 | ||
1538 | /* If we've found a names, break out of the "order" loop */ | |
1539 | ||
1540 | if (sender_host_name != NULL) break; | |
1541 | } | |
1542 | ||
1543 | /* If the DNS lookup deferred, we must also defer. */ | |
1544 | ||
1545 | if (rc == DNS_AGAIN) | |
1546 | { | |
1547 | HDEBUG(D_host_lookup) | |
1548 | debug_printf("IP address PTR lookup gave temporary error\n"); | |
8e669ac1 | 1549 | host_lookup_deferred = TRUE; |
059ec3d9 PH |
1550 | return DEFER; |
1551 | } | |
1552 | } | |
1553 | ||
1554 | /* Do a lookup using gethostbyaddr() - or equivalent */ | |
1555 | ||
1556 | else if (strcmpic(ordername, US"byaddr") == 0) | |
1557 | { | |
1558 | HDEBUG(D_host_lookup) | |
1559 | debug_printf("IP address lookup using gethostbyaddr()\n"); | |
059ec3d9 | 1560 | rc = host_name_lookup_byaddr(); |
8e669ac1 | 1561 | if (rc == DEFER) |
b08b24c8 | 1562 | { |
8e669ac1 | 1563 | host_lookup_deferred = TRUE; |
b08b24c8 | 1564 | return rc; /* Can't carry on */ |
8e669ac1 | 1565 | } |
059ec3d9 PH |
1566 | if (rc == OK) break; /* Found a name */ |
1567 | } | |
1568 | } /* Loop for bydns/byaddr scanning */ | |
1569 | ||
1570 | /* If we have failed to find a name, return FAIL and log when required. | |
1571 | NB host_lookup_msg must be in permanent store. */ | |
1572 | ||
1573 | if (sender_host_name == NULL) | |
1574 | { | |
1575 | if (host_checking || !log_testing_mode) | |
1576 | log_write(L_host_lookup_failed, LOG_MAIN, "no host name found for IP " | |
1577 | "address %s", sender_host_address); | |
1578 | host_lookup_msg = US" (failed to find host name from IP address)"; | |
b08b24c8 | 1579 | host_lookup_failed = TRUE; |
059ec3d9 PH |
1580 | return FAIL; |
1581 | } | |
1582 | ||
1583 | /* We have a host name. If we are running in the test harness, we want the host | |
1584 | name and its alias to appear always the same way round. There are only ever two | |
1585 | names in these tests. If one of them contains "alias", make sure it is second; | |
1586 | otherwise put them in alphabetical order. */ | |
1587 | ||
1588 | if (running_in_test_harness && *sender_host_aliases != NULL && | |
1589 | ( | |
1590 | Ustrstr(sender_host_name, "alias") != NULL || | |
1591 | ( | |
1592 | Ustrstr(*sender_host_aliases, "alias") == NULL && | |
1593 | Ustrcmp(sender_host_name, *sender_host_aliases) > 0 | |
1594 | ) | |
1595 | )) | |
1596 | { | |
1597 | uschar *temp = sender_host_name; | |
1598 | sender_host_name = *sender_host_aliases; | |
1599 | *sender_host_aliases = temp; | |
1600 | } | |
1601 | ||
1602 | /* Debug output what was found, after test harness swapping, for consistency */ | |
1603 | ||
1604 | HDEBUG(D_host_lookup) | |
1605 | { | |
1606 | uschar **aliases = sender_host_aliases; | |
1607 | debug_printf("IP address lookup yielded %s\n", sender_host_name); | |
1608 | while (*aliases != NULL) debug_printf(" alias %s\n", *aliases++); | |
1609 | } | |
1610 | ||
1611 | /* We need to verify that a forward lookup on the name we found does indeed | |
1612 | correspond to the address. This is for security: in principle a malefactor who | |
1613 | happened to own a reverse zone could set it to point to any names at all. | |
1614 | ||
1615 | This code was present in versions of Exim before 3.20. At that point I took it | |
1616 | out because I thought that gethostbyaddr() did the check anyway. It turns out | |
1617 | that this isn't always the case, so it's coming back in at 4.01. This version | |
1618 | is actually better, because it also checks aliases. | |
1619 | ||
1620 | The code was made more robust at release 4.21. Prior to that, it accepted all | |
1621 | the names if any of them had the correct IP address. Now the code checks all | |
1622 | the names, and accepts only those that have the correct IP address. */ | |
1623 | ||
1624 | save_hostname = sender_host_name; /* Save for error messages */ | |
1625 | aliases = sender_host_aliases; | |
1626 | for (hname = sender_host_name; hname != NULL; hname = *aliases++) | |
1627 | { | |
1628 | int rc; | |
1629 | BOOL ok = FALSE; | |
1630 | host_item h; | |
1631 | h.next = NULL; | |
1632 | h.name = hname; | |
1633 | h.mx = MX_NONE; | |
1634 | h.address = NULL; | |
1635 | ||
1636 | /* When called with the 5th argument FALSE, host_find_byname() won't return | |
1637 | HOST_FOUND_LOCAL. If the incoming address is an IPv4 address expressed in | |
1638 | IPv6 format, we must compare the IPv4 part to any IPv4 addresses. */ | |
1639 | ||
1640 | if ((rc = host_find_byname(&h, NULL, NULL, FALSE)) == HOST_FOUND) | |
1641 | { | |
1642 | host_item *hh; | |
1643 | uschar *address_ipv4 = (Ustrncmp(sender_host_address, "::ffff:", 7) == 0)? | |
1644 | sender_host_address + 7 : sender_host_address; | |
1645 | HDEBUG(D_host_lookup) debug_printf("checking addresses for %s\n", hname); | |
1646 | for (hh = &h; hh != NULL; hh = hh->next) | |
1647 | { | |
1648 | if ((Ustrcmp(hh->address, (Ustrchr(hh->address, ':') == NULL)? | |
1649 | address_ipv4 : sender_host_address)) == 0) | |
1650 | { | |
1651 | HDEBUG(D_host_lookup) debug_printf(" %s OK\n", hh->address); | |
1652 | ok = TRUE; | |
1653 | break; | |
1654 | } | |
1655 | else | |
1656 | { | |
1657 | HDEBUG(D_host_lookup) debug_printf(" %s\n", hh->address); | |
1658 | } | |
1659 | } | |
1660 | if (!ok) HDEBUG(D_host_lookup) | |
1661 | debug_printf("no IP address for %s matched %s\n", hname, | |
1662 | sender_host_address); | |
1663 | } | |
1664 | else if (rc == HOST_FIND_AGAIN) | |
1665 | { | |
1666 | HDEBUG(D_host_lookup) debug_printf("temporary error for host name lookup\n"); | |
8e669ac1 | 1667 | host_lookup_deferred = TRUE; |
059ec3d9 PH |
1668 | return DEFER; |
1669 | } | |
1670 | else | |
1671 | { | |
1672 | HDEBUG(D_host_lookup) debug_printf("no IP addresses found for %s\n", hname); | |
1673 | } | |
1674 | ||
1675 | /* If this name is no good, and it's the sender name, set it null pro tem; | |
1676 | if it's an alias, just remove it from the list. */ | |
1677 | ||
1678 | if (!ok) | |
1679 | { | |
1680 | if (hname == sender_host_name) sender_host_name = NULL; else | |
1681 | { | |
1682 | uschar **a; /* Don't amalgamate - some */ | |
1683 | a = --aliases; /* compilers grumble */ | |
1684 | while (*a != NULL) { *a = a[1]; a++; } | |
1685 | } | |
1686 | } | |
1687 | } | |
1688 | ||
1689 | /* If sender_host_name == NULL, it means we didn't like the name. Replace | |
1690 | it with the first alias, if there is one. */ | |
1691 | ||
1692 | if (sender_host_name == NULL && *sender_host_aliases != NULL) | |
1693 | sender_host_name = *sender_host_aliases++; | |
1694 | ||
1695 | /* If we now have a main name, all is well. */ | |
1696 | ||
1697 | if (sender_host_name != NULL) return OK; | |
1698 | ||
1699 | /* We have failed to find an address that matches. */ | |
1700 | ||
1701 | HDEBUG(D_host_lookup) | |
1702 | debug_printf("%s does not match any IP address for %s\n", | |
1703 | sender_host_address, save_hostname); | |
1704 | ||
1705 | /* This message must be in permanent store */ | |
1706 | ||
1707 | old_pool = store_pool; | |
1708 | store_pool = POOL_PERM; | |
1709 | host_lookup_msg = string_sprintf(" (%s does not match any IP address for %s)", | |
1710 | sender_host_address, save_hostname); | |
1711 | store_pool = old_pool; | |
059ec3d9 PH |
1712 | host_lookup_failed = TRUE; |
1713 | return FAIL; | |
1714 | } | |
1715 | ||
1716 | ||
1717 | ||
1718 | ||
1719 | /************************************************* | |
1720 | * Find IP address(es) for host by name * | |
1721 | *************************************************/ | |
1722 | ||
1723 | /* The input is a host_item structure with the name filled in and the address | |
1724 | field set to NULL. We use gethostbyname(). Of course, gethostbyname() may use | |
1725 | the DNS, but it doesn't do MX processing. If more than one address is given, | |
1726 | chain on additional host items, with other relevant fields copied. | |
1727 | ||
1728 | The second argument provides a host list (usually an IP list) of hosts to | |
1729 | ignore. This makes it possible to ignore IPv6 link-local addresses or loopback | |
1730 | addresses in unreasonable places. | |
1731 | ||
1732 | The lookup may result in a change of name. For compatibility with the dns | |
1733 | lookup, return this via fully_qualified_name as well as updating the host item. | |
1734 | The lookup may also yield more than one IP address, in which case chain on | |
1735 | subsequent host_item structures. | |
1736 | ||
1737 | Arguments: | |
1738 | host a host item with the name and MX filled in; | |
1739 | the address is to be filled in; | |
1740 | multiple IP addresses cause other host items to be | |
1741 | chained on. | |
1742 | ignore_target_hosts a list of hosts to ignore | |
1743 | fully_qualified_name if not NULL, set to point to host name for | |
1744 | compatibility with host_find_bydns | |
1745 | local_host_check TRUE if a check for the local host is wanted | |
1746 | ||
1747 | Returns: HOST_FIND_FAILED Failed to find the host or domain | |
1748 | HOST_FIND_AGAIN Try again later | |
1749 | HOST_FOUND Host found - data filled in | |
1750 | HOST_FOUND_LOCAL Host found and is the local host | |
1751 | */ | |
1752 | ||
1753 | int | |
1754 | host_find_byname(host_item *host, uschar *ignore_target_hosts, | |
1755 | uschar **fully_qualified_name, BOOL local_host_check) | |
1756 | { | |
1757 | int i, yield, times; | |
1758 | uschar **addrlist; | |
1759 | host_item *last = NULL; | |
1760 | BOOL temp_error = FALSE; | |
b08b24c8 PH |
1761 | #if HAVE_IPV6 |
1762 | int af; | |
1763 | #endif | |
1764 | ||
1765 | /* If we are in the test harness, a name ending in .test.again.dns always | |
1766 | forces a temporary error response. */ | |
1767 | ||
1768 | if (running_in_test_harness) | |
1769 | { | |
1770 | uschar *endname = host->name + Ustrlen(host->name); | |
1771 | if (Ustrcmp(endname - 14, "test.again.dns") == 0) | |
1772 | return HOST_FIND_AGAIN; | |
8e669ac1 | 1773 | } |
059ec3d9 PH |
1774 | |
1775 | /* In an IPv6 world, we need to scan for both kinds of address, so go round the | |
1776 | loop twice. Note that we have ensured that AF_INET6 is defined even in an IPv4 | |
1777 | world, which makes for slightly tidier code. However, if dns_ipv4_lookup | |
1778 | matches the domain, we also just do IPv4 lookups here (except when testing | |
1779 | standalone). */ | |
1780 | ||
1781 | #if HAVE_IPV6 | |
059ec3d9 PH |
1782 | #ifndef STAND_ALONE |
1783 | if (dns_ipv4_lookup != NULL && | |
1784 | match_isinlist(host->name, &dns_ipv4_lookup, 0, NULL, NULL, MCL_DOMAIN, | |
1785 | TRUE, NULL) == OK) | |
1786 | { af = AF_INET; times = 1; } | |
1787 | else | |
1788 | #endif /* STAND_ALONE */ | |
1789 | ||
1790 | { af = AF_INET6; times = 2; } | |
1791 | ||
1792 | /* No IPv6 support */ | |
1793 | ||
1794 | #else /* HAVE_IPV6 */ | |
1795 | times = 1; | |
1796 | #endif /* HAVE_IPV6 */ | |
1797 | ||
1798 | /* Initialize the flag that gets set for DNS syntax check errors, so that the | |
1799 | interface to this function can be similar to host_find_bydns. */ | |
1800 | ||
1801 | host_find_failed_syntax = FALSE; | |
1802 | ||
1803 | /* Loop to look up both kinds of address in an IPv6 world */ | |
1804 | ||
1805 | for (i = 1; i <= times; | |
1806 | #if HAVE_IPV6 | |
1807 | af = AF_INET, /* If 2 passes, IPv4 on the second */ | |
1808 | #endif | |
1809 | i++) | |
1810 | { | |
1811 | BOOL ipv4_addr; | |
1812 | int error_num; | |
1813 | struct hostent *hostdata; | |
1814 | ||
1815 | #if HAVE_IPV6 | |
1816 | #if HAVE_GETIPNODEBYNAME | |
1817 | hostdata = getipnodebyname(CS host->name, af, 0, &error_num); | |
1818 | #else | |
1819 | hostdata = gethostbyname2(CS host->name, af); | |
1820 | error_num = h_errno; | |
1821 | #endif | |
1822 | #else | |
1823 | hostdata = gethostbyname(CS host->name); | |
1824 | error_num = h_errno; | |
1825 | #endif | |
1826 | ||
1827 | if (hostdata == NULL) | |
1828 | { | |
1829 | uschar *error; | |
1830 | switch (error_num) | |
1831 | { | |
1832 | case HOST_NOT_FOUND: error = US"HOST_NOT_FOUND"; break; | |
1833 | case TRY_AGAIN: error = US"TRY_AGAIN"; break; | |
1834 | case NO_RECOVERY: error = US"NO_RECOVERY"; break; | |
1835 | case NO_DATA: error = US"NO_DATA"; break; | |
1836 | #if NO_DATA != NO_ADDRESS | |
1837 | case NO_ADDRESS: error = US"NO_ADDRESS"; break; | |
1838 | #endif | |
1839 | default: error = US"?"; break; | |
1840 | } | |
1841 | ||
1842 | DEBUG(D_host_lookup) debug_printf("%s returned %d (%s)\n", | |
1843 | #if HAVE_IPV6 | |
1844 | #if HAVE_GETIPNODEBYNAME | |
1845 | (af == AF_INET6)? "getipnodebyname(af=inet6)" : "getipnodebyname(af=inet)", | |
1846 | #else | |
1847 | (af == AF_INET6)? "gethostbyname2(af=inet6)" : "gethostbyname2(af=inet)", | |
1848 | #endif | |
1849 | #else | |
1850 | "gethostbyname", | |
1851 | #endif | |
1852 | error_num, error); | |
1853 | ||
1854 | if (error_num == TRY_AGAIN || error_num == NO_RECOVERY) temp_error = TRUE; | |
1855 | continue; | |
1856 | } | |
1857 | if ((hostdata->h_addr_list)[0] == NULL) continue; | |
1858 | ||
1859 | /* Replace the name with the fully qualified one if necessary, and fill in | |
1860 | the fully_qualified_name pointer. */ | |
1861 | ||
1862 | if (hostdata->h_name[0] != 0 && | |
1863 | Ustrcmp(host->name, hostdata->h_name) != 0) | |
1864 | host->name = string_copy_dnsdomain((uschar *)hostdata->h_name); | |
1865 | if (fully_qualified_name != NULL) *fully_qualified_name = host->name; | |
1866 | ||
1867 | /* Get the list of addresses. IPv4 and IPv6 addresses can be distinguished | |
1868 | by their different lengths. Scan the list, ignoring any that are to be | |
1869 | ignored, and build a chain from the rest. */ | |
1870 | ||
1871 | ipv4_addr = hostdata->h_length == sizeof(struct in_addr); | |
1872 | ||
1873 | for (addrlist = USS hostdata->h_addr_list; *addrlist != NULL; addrlist++) | |
1874 | { | |
1875 | uschar *text_address = | |
1876 | host_ntoa(ipv4_addr? AF_INET:AF_INET6, *addrlist, NULL, NULL); | |
1877 | ||
1878 | #ifndef STAND_ALONE | |
1879 | if (ignore_target_hosts != NULL && | |
1880 | verify_check_this_host(&ignore_target_hosts, NULL, host->name, | |
1881 | text_address, NULL) == OK) | |
1882 | { | |
1883 | DEBUG(D_host_lookup) | |
1884 | debug_printf("ignored host %s [%s]\n", host->name, text_address); | |
1885 | continue; | |
1886 | } | |
1887 | #endif | |
1888 | ||
1889 | /* If this is the first address, last == NULL and we put the data in the | |
1890 | original block. */ | |
1891 | ||
1892 | if (last == NULL) | |
1893 | { | |
1894 | host->address = text_address; | |
1895 | host->port = PORT_NONE; | |
1896 | host->status = hstatus_unknown; | |
1897 | host->why = hwhy_unknown; | |
1898 | last = host; | |
1899 | } | |
1900 | ||
1901 | /* Else add further host item blocks for any other addresses, keeping | |
1902 | the order. */ | |
1903 | ||
1904 | else | |
1905 | { | |
1906 | host_item *next = store_get(sizeof(host_item)); | |
1907 | next->name = host->name; | |
1908 | next->mx = host->mx; | |
1909 | next->address = text_address; | |
1910 | next->port = PORT_NONE; | |
1911 | next->status = hstatus_unknown; | |
1912 | next->why = hwhy_unknown; | |
1913 | next->last_try = 0; | |
1914 | next->next = last->next; | |
1915 | last->next = next; | |
1916 | last = next; | |
1917 | } | |
1918 | } | |
1919 | } | |
1920 | ||
1921 | /* If no hosts were found, the address field in the original host block will be | |
1922 | NULL. If temp_error is set, at least one of the lookups gave a temporary error, | |
1923 | so we pass that back. */ | |
1924 | ||
1925 | if (host->address == NULL) | |
1926 | { | |
1927 | uschar *msg = | |
1928 | #ifndef STAND_ALONE | |
1929 | (message_id[0] == 0 && smtp_in != NULL)? | |
1930 | string_sprintf("no IP address found for host %s (during %s)", host->name, | |
1931 | smtp_get_connection_info()) : | |
1932 | #endif | |
1933 | string_sprintf("no IP address found for host %s", host->name); | |
1934 | ||
1935 | HDEBUG(D_host_lookup) debug_printf("%s\n", msg); | |
1936 | if (temp_error) return HOST_FIND_AGAIN; | |
1937 | if (host_checking || !log_testing_mode) | |
1938 | log_write(L_host_lookup_failed, LOG_MAIN, "%s", msg); | |
1939 | return HOST_FIND_FAILED; | |
1940 | } | |
1941 | ||
1942 | /* Remove any duplicate IP addresses, then check to see if this is the local | |
1943 | host if required. */ | |
1944 | ||
1945 | host_remove_duplicates(host, &last); | |
1946 | yield = local_host_check? | |
1947 | host_scan_for_local_hosts(host, &last, NULL) : HOST_FOUND; | |
1948 | ||
1949 | /* When running in the test harness, sort into the order of addresses so as to | |
d8ef3577 | 1950 | get repeatability. */ |
059ec3d9 | 1951 | |
d8ef3577 | 1952 | if (running_in_test_harness) sort_addresses(host, last); |
059ec3d9 PH |
1953 | |
1954 | HDEBUG(D_host_lookup) | |
1955 | { | |
1956 | host_item *h; | |
1957 | if (fully_qualified_name != NULL) | |
1958 | debug_printf("fully qualified name = %s\n", *fully_qualified_name); | |
1959 | debug_printf("%s looked up these IP addresses:\n", | |
1960 | #if HAVE_IPV6 | |
1961 | #if HAVE_GETIPNODEBYNAME | |
1962 | "getipnodebyname" | |
1963 | #else | |
1964 | "gethostbyname2" | |
1965 | #endif | |
1966 | #else | |
1967 | "gethostbyname" | |
1968 | #endif | |
1969 | ); | |
1970 | for (h = host; h != last->next; h = h->next) | |
1971 | debug_printf(" name=%s address=%s\n", h->name, | |
1972 | (h->address == NULL)? US"<null>" : h->address); | |
1973 | } | |
1974 | ||
1975 | /* Return the found status. */ | |
1976 | ||
1977 | return yield; | |
1978 | } | |
1979 | ||
1980 | ||
1981 | ||
1982 | /************************************************* | |
1983 | * Fill in a host address from the DNS * | |
1984 | *************************************************/ | |
1985 | ||
1986 | /* Given a host item, with its name and mx fields set, and its address field | |
1987 | set to NULL, fill in its IP address from the DNS. If it is multi-homed, create | |
1988 | additional host items for the additional addresses, copying all the other | |
1989 | fields, and randomizing the order. | |
1990 | ||
1991 | On IPv6 systems, A6 records are sought first (but only if support for A6 is | |
1992 | configured - they may never become mainstream), then AAAA records are sought, | |
1993 | and finally A records are sought as well. | |
1994 | ||
1995 | The host name may be changed if the DNS returns a different name - e.g. fully | |
1996 | qualified or changed via CNAME. If fully_qualified_name is not NULL, dns_lookup | |
1997 | ensures that it points to the fully qualified name. However, this is the fully | |
1998 | qualified version of the original name; if a CNAME is involved, the actual | |
1999 | canonical host name may be different again, and so we get it directly from the | |
2000 | relevant RR. Note that we do NOT change the mx field of the host item in this | |
2001 | function as it may be called to set the addresses of hosts taken from MX | |
2002 | records. | |
2003 | ||
2004 | Arguments: | |
2005 | host points to the host item we're filling in | |
2006 | lastptr points to pointer to last host item in a chain of | |
2007 | host items (may be updated if host is last and gets | |
2008 | extended because multihomed) | |
2009 | ignore_target_hosts list of hosts to ignore | |
2010 | allow_ip if TRUE, recognize an IP address and return it | |
2011 | fully_qualified_name if not NULL, return fully qualified name here if | |
2012 | the contents are different (i.e. it must be preset | |
2013 | to something) | |
2014 | ||
2015 | Returns: HOST_FIND_FAILED couldn't find A record | |
2016 | HOST_FIND_AGAIN try again later | |
2017 | HOST_FOUND found AAAA and/or A record(s) | |
2018 | HOST_IGNORED found, but all IPs ignored | |
2019 | */ | |
2020 | ||
2021 | static int | |
2022 | set_address_from_dns(host_item *host, host_item **lastptr, | |
2023 | uschar *ignore_target_hosts, BOOL allow_ip, uschar **fully_qualified_name) | |
2024 | { | |
2025 | dns_record *rr; | |
2026 | host_item *thishostlast = NULL; /* Indicates not yet filled in anything */ | |
2027 | BOOL v6_find_again = FALSE; | |
2028 | int i; | |
2029 | ||
2030 | /* If allow_ip is set, a name which is an IP address returns that value | |
2031 | as its address. This is used for MX records when allow_mx_to_ip is set, for | |
2032 | those sites that feel they have to flaunt the RFC rules. */ | |
2033 | ||
2034 | if (allow_ip && string_is_ip_address(host->name, NULL) != 0) | |
2035 | { | |
2036 | #ifndef STAND_ALONE | |
2037 | if (ignore_target_hosts != NULL && | |
2038 | verify_check_this_host(&ignore_target_hosts, NULL, host->name, | |
2039 | host->name, NULL) == OK) | |
2040 | return HOST_IGNORED; | |
2041 | #endif | |
2042 | ||
2043 | host->address = host->name; | |
2044 | host->port = PORT_NONE; | |
2045 | return HOST_FOUND; | |
2046 | } | |
2047 | ||
2048 | /* On an IPv6 system, go round the loop up to three times, looking for A6 and | |
2049 | AAAA records the first two times. However, unless doing standalone testing, we | |
2050 | force an IPv4 lookup if the domain matches dns_ipv4_lookup is set. Since A6 | |
2051 | records look like being abandoned, support them only if explicitly configured | |
2052 | to do so. On an IPv4 system, go round the loop once only, looking only for A | |
2053 | records. */ | |
2054 | ||
2055 | #if HAVE_IPV6 | |
2056 | ||
2057 | #ifndef STAND_ALONE | |
2058 | if (dns_ipv4_lookup != NULL && | |
2059 | match_isinlist(host->name, &dns_ipv4_lookup, 0, NULL, NULL, MCL_DOMAIN, | |
2060 | TRUE, NULL) == OK) | |
2061 | i = 0; /* look up A records only */ | |
2062 | else | |
2063 | #endif /* STAND_ALONE */ | |
2064 | ||
2065 | #ifdef SUPPORT_A6 | |
2066 | i = 2; /* look up A6 and AAAA and A records */ | |
2067 | #else | |
2068 | i = 1; /* look up AAAA and A records */ | |
2069 | #endif /* SUPPORT_A6 */ | |
2070 | ||
2071 | /* The IPv4 world */ | |
2072 | ||
2073 | #else /* HAVE_IPV6 */ | |
2074 | i = 0; /* look up A records only */ | |
2075 | #endif /* HAVE_IPV6 */ | |
2076 | ||
2077 | for (; i >= 0; i--) | |
2078 | { | |
2079 | static int types[] = { T_A, T_AAAA, T_A6 }; | |
2080 | int type = types[i]; | |
2081 | int randoffset = (i == 0)? 500 : 0; /* Ensures v6 sorts before v4 */ | |
2082 | dns_answer dnsa; | |
2083 | dns_scan dnss; | |
2084 | ||
2085 | int rc = dns_lookup(&dnsa, host->name, type, fully_qualified_name); | |
2086 | ||
2087 | /* We want to return HOST_FIND_AGAIN if one of the A, A6, or AAAA lookups | |
2088 | fails or times out, but not if another one succeeds. (In the early | |
2089 | IPv6 days there are name servers that always fail on AAAA, but are happy | |
2090 | to give out an A record. We want to proceed with that A record.) */ | |
8e669ac1 | 2091 | |
059ec3d9 PH |
2092 | if (rc != DNS_SUCCEED) |
2093 | { | |
2094 | if (i == 0) /* Just tried for an A record, i.e. end of loop */ | |
2095 | { | |
2096 | if (host->address != NULL) return HOST_FOUND; /* A6 or AAAA was found */ | |
2097 | if (rc == DNS_AGAIN || rc == DNS_FAIL || v6_find_again) | |
2098 | return HOST_FIND_AGAIN; | |
2099 | return HOST_FIND_FAILED; /* DNS_NOMATCH or DNS_NODATA */ | |
2100 | } | |
2101 | ||
2102 | /* Tried for an A6 or AAAA record: remember if this was a temporary | |
2103 | error, and look for the next record type. */ | |
2104 | ||
2105 | if (rc != DNS_NOMATCH && rc != DNS_NODATA) v6_find_again = TRUE; | |
2106 | continue; | |
2107 | } | |
2108 | ||
2109 | /* Lookup succeeded: fill in the given host item with the first non-ignored | |
2110 | address found; create additional items for any others. A single A6 record | |
2111 | may generate more than one address. */ | |
2112 | ||
2113 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
2114 | rr != NULL; | |
2115 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2116 | { | |
2117 | if (rr->type == type) | |
2118 | { | |
2119 | /* dns_address *da = dns_address_from_rr(&dnsa, rr); */ | |
2120 | ||
2121 | dns_address *da; | |
2122 | da = dns_address_from_rr(&dnsa, rr); | |
2123 | ||
2124 | DEBUG(D_host_lookup) | |
2125 | { | |
2126 | if (da == NULL) | |
2127 | debug_printf("no addresses extracted from A6 RR for %s\n", | |
2128 | host->name); | |
2129 | } | |
2130 | ||
2131 | /* This loop runs only once for A and AAAA records, but may run | |
2132 | several times for an A6 record that generated multiple addresses. */ | |
2133 | ||
2134 | for (; da != NULL; da = da->next) | |
2135 | { | |
2136 | #ifndef STAND_ALONE | |
2137 | if (ignore_target_hosts != NULL && | |
2138 | verify_check_this_host(&ignore_target_hosts, NULL, | |
2139 | host->name, da->address, NULL) == OK) | |
2140 | { | |
2141 | DEBUG(D_host_lookup) | |
2142 | debug_printf("ignored host %s [%s]\n", host->name, da->address); | |
2143 | continue; | |
2144 | } | |
2145 | #endif | |
2146 | ||
2147 | /* If this is the first address, stick it in the given host block, | |
2148 | and change the name if the returned RR has a different name. */ | |
2149 | ||
2150 | if (thishostlast == NULL) | |
2151 | { | |
2152 | if (strcmpic(host->name, rr->name) != 0) | |
2153 | host->name = string_copy_dnsdomain(rr->name); | |
2154 | host->address = da->address; | |
2155 | host->port = PORT_NONE; | |
2156 | host->sort_key = host->mx * 1000 + random_number(500) + randoffset; | |
2157 | host->status = hstatus_unknown; | |
2158 | host->why = hwhy_unknown; | |
2159 | thishostlast = host; | |
2160 | } | |
2161 | ||
2162 | /* Not the first address. Check for, and ignore, duplicates. Then | |
2163 | insert in the chain at a random point. */ | |
2164 | ||
2165 | else | |
2166 | { | |
2167 | int new_sort_key; | |
2168 | host_item *next; | |
2169 | ||
2170 | /* End of our local chain is specified by "thishostlast". */ | |
2171 | ||
2172 | for (next = host;; next = next->next) | |
2173 | { | |
2174 | if (Ustrcmp(CS da->address, next->address) == 0) break; | |
2175 | if (next == thishostlast) { next = NULL; break; } | |
2176 | } | |
2177 | if (next != NULL) continue; /* With loop for next address */ | |
2178 | ||
2179 | /* Not a duplicate */ | |
2180 | ||
2181 | new_sort_key = host->mx * 1000 + random_number(500) + randoffset; | |
2182 | next = store_get(sizeof(host_item)); | |
2183 | ||
2184 | /* New address goes first: insert the new block after the first one | |
2185 | (so as not to disturb the original pointer) but put the new address | |
2186 | in the original block. */ | |
2187 | ||
2188 | if (new_sort_key < host->sort_key) | |
2189 | { | |
2190 | *next = *host; | |
2191 | host->next = next; | |
2192 | host->address = da->address; | |
2193 | host->port = PORT_NONE; | |
2194 | host->sort_key = new_sort_key; | |
2195 | if (thishostlast == host) thishostlast = next; /* Local last */ | |
2196 | if (*lastptr == host) *lastptr = next; /* Global last */ | |
2197 | } | |
2198 | ||
2199 | /* Otherwise scan down the addresses for this host to find the | |
2200 | one to insert after. */ | |
2201 | ||
2202 | else | |
2203 | { | |
2204 | host_item *h = host; | |
2205 | while (h != thishostlast) | |
2206 | { | |
2207 | if (new_sort_key < h->next->sort_key) break; | |
2208 | h = h->next; | |
2209 | } | |
2210 | *next = *h; | |
2211 | h->next = next; | |
2212 | next->address = da->address; | |
2213 | next->port = PORT_NONE; | |
2214 | next->sort_key = new_sort_key; | |
2215 | if (h == thishostlast) thishostlast = next; /* Local last */ | |
2216 | if (h == *lastptr) *lastptr = next; /* Global last */ | |
2217 | } | |
2218 | } | |
2219 | } | |
2220 | } | |
2221 | } | |
2222 | } | |
2223 | ||
2224 | /* Control gets here only if the third lookup (the A record) succeeded. | |
2225 | However, the address may not be filled in if it was ignored. */ | |
2226 | ||
2227 | return (host->address == NULL)? HOST_IGNORED : HOST_FOUND; | |
2228 | } | |
2229 | ||
2230 | ||
2231 | ||
2232 | ||
2233 | /************************************************* | |
2234 | * Find IP addresses and names for host via DNS * | |
2235 | *************************************************/ | |
2236 | ||
2237 | /* The input is a host_item structure with the name filled in and the address | |
2238 | field set to NULL. This may be in a chain of other host items. The lookup may | |
2239 | result in more than one IP address, in which case we must created new host | |
2240 | blocks for the additional addresses, and insert them into the chain. The | |
2241 | original name may not be fully qualified. Use the fully_qualified_name argument | |
2242 | to return the official name, as returned by the resolver. | |
2243 | ||
2244 | Arguments: | |
2245 | host point to initial host item | |
2246 | ignore_target_hosts a list of hosts to ignore | |
2247 | whichrrs flags indicating which RRs to look for: | |
2248 | HOST_FIND_BY_SRV => look for SRV | |
2249 | HOST_FIND_BY_MX => look for MX | |
2250 | HOST_FIND_BY_A => look for A or AAAA | |
2251 | also flags indicating how the lookup is done | |
2252 | HOST_FIND_QUALIFY_SINGLE ) passed to the | |
2253 | HOST_FIND_SEARCH_PARENTS ) resolver | |
2254 | srv_service when SRV used, the service name | |
2255 | srv_fail_domains DNS errors for these domains => assume nonexist | |
2256 | mx_fail_domains DNS errors for these domains => assume nonexist | |
2257 | fully_qualified_name if not NULL, return fully-qualified name | |
2258 | removed set TRUE if local host was removed from the list | |
2259 | ||
2260 | Returns: HOST_FIND_FAILED Failed to find the host or domain; | |
2261 | if there was a syntax error, | |
2262 | host_find_failed_syntax is set. | |
2263 | HOST_FIND_AGAIN Could not resolve at this time | |
2264 | HOST_FOUND Host found | |
2265 | HOST_FOUND_LOCAL The lowest MX record points to this | |
2266 | machine, if MX records were found, or | |
2267 | an A record that was found contains | |
2268 | an address of the local host | |
2269 | */ | |
2270 | ||
2271 | int | |
2272 | host_find_bydns(host_item *host, uschar *ignore_target_hosts, int whichrrs, | |
2273 | uschar *srv_service, uschar *srv_fail_domains, uschar *mx_fail_domains, | |
2274 | uschar **fully_qualified_name, BOOL *removed) | |
2275 | { | |
2276 | host_item *h, *last; | |
2277 | dns_record *rr; | |
2278 | int rc = DNS_FAIL; | |
2279 | int ind_type = 0; | |
2280 | int yield; | |
2281 | dns_answer dnsa; | |
2282 | dns_scan dnss; | |
2283 | ||
2284 | /* Set the default fully qualified name to the incoming name, initialize the | |
2285 | resolver if necessary, set up the relevant options, and initialize the flag | |
2286 | that gets set for DNS syntax check errors. */ | |
2287 | ||
2288 | if (fully_qualified_name != NULL) *fully_qualified_name = host->name; | |
2289 | dns_init((whichrrs & HOST_FIND_QUALIFY_SINGLE) != 0, | |
2290 | (whichrrs & HOST_FIND_SEARCH_PARENTS) != 0); | |
2291 | host_find_failed_syntax = FALSE; | |
2292 | ||
2293 | /* First, if requested, look for SRV records. The service name is given; we | |
2294 | assume TCP progocol. DNS domain names are constrained to a maximum of 256 | |
2295 | characters, so the code below should be safe. */ | |
2296 | ||
2297 | if ((whichrrs & HOST_FIND_BY_SRV) != 0) | |
2298 | { | |
2299 | uschar buffer[300]; | |
2300 | uschar *temp_fully_qualified_name = buffer; | |
2301 | int prefix_length; | |
2302 | ||
2303 | (void)sprintf(CS buffer, "_%s._tcp.%n%.256s", srv_service, &prefix_length, | |
2304 | host->name); | |
2305 | ind_type = T_SRV; | |
2306 | ||
2307 | /* Search for SRV records. If the fully qualified name is different to | |
2308 | the input name, pass back the new original domain, without the prepended | |
2309 | magic. */ | |
2310 | ||
2311 | rc = dns_lookup(&dnsa, buffer, ind_type, &temp_fully_qualified_name); | |
2312 | if (temp_fully_qualified_name != buffer && fully_qualified_name != NULL) | |
2313 | *fully_qualified_name = temp_fully_qualified_name + prefix_length; | |
2314 | ||
2315 | /* On DNS failures, we give the "try again" error unless the domain is | |
2316 | listed as one for which we continue. */ | |
2317 | ||
2318 | if (rc == DNS_FAIL || rc == DNS_AGAIN) | |
2319 | { | |
2320 | if (match_isinlist(host->name, &srv_fail_domains, 0, NULL, NULL, MCL_DOMAIN, | |
2321 | TRUE, NULL) != OK) | |
2322 | return HOST_FIND_AGAIN; | |
2323 | DEBUG(D_host_lookup) debug_printf("DNS_%s treated as DNS_NODATA " | |
2324 | "(domain in srv_fail_domains)\n", (rc == DNS_FAIL)? "FAIL":"AGAIN"); | |
2325 | } | |
2326 | } | |
2327 | ||
2328 | /* If we did not find any SRV records, search the DNS for MX records, if | |
2329 | requested to do so. If the result is DNS_NOMATCH, it means there is no such | |
2330 | domain, and there's no point in going on to look for address records with the | |
2331 | same domain. The result will be DNS_NODATA if the domain exists but has no MX | |
2332 | records. On DNS failures, we give the "try again" error unless the domain is | |
2333 | listed as one for which we continue. */ | |
2334 | ||
2335 | if (rc != DNS_SUCCEED && (whichrrs & HOST_FIND_BY_MX) != 0) | |
2336 | { | |
2337 | ind_type = T_MX; | |
2338 | rc = dns_lookup(&dnsa, host->name, ind_type, fully_qualified_name); | |
2339 | if (rc == DNS_NOMATCH) return HOST_FIND_FAILED; | |
2340 | if (rc == DNS_FAIL || rc == DNS_AGAIN) | |
2341 | { | |
2342 | if (match_isinlist(host->name, &mx_fail_domains, 0, NULL, NULL, MCL_DOMAIN, | |
2343 | TRUE, NULL) != OK) | |
2344 | return HOST_FIND_AGAIN; | |
2345 | DEBUG(D_host_lookup) debug_printf("DNS_%s treated as DNS_NODATA " | |
2346 | "(domain in mx_fail_domains)\n", (rc == DNS_FAIL)? "FAIL":"AGAIN"); | |
2347 | } | |
2348 | } | |
2349 | ||
2350 | /* If we haven't found anything yet, and we are requested to do so, try for an | |
2351 | A or AAAA record. If we find it (or them) check to see that it isn't the local | |
2352 | host. */ | |
2353 | ||
2354 | if (rc != DNS_SUCCEED) | |
2355 | { | |
2356 | if ((whichrrs & HOST_FIND_BY_A) == 0) | |
2357 | { | |
2358 | DEBUG(D_host_lookup) debug_printf("Address records are not being sought\n"); | |
2359 | return HOST_FIND_FAILED; | |
2360 | } | |
2361 | ||
2362 | last = host; /* End of local chainlet */ | |
2363 | host->mx = MX_NONE; | |
2364 | host->port = PORT_NONE; | |
2365 | rc = set_address_from_dns(host, &last, ignore_target_hosts, FALSE, | |
2366 | fully_qualified_name); | |
2367 | ||
2368 | /* If one or more address records have been found, check that none of them | |
2369 | are local. Since we know the host items all have their IP addresses | |
2370 | inserted, host_scan_for_local_hosts() can only return HOST_FOUND or | |
2371 | HOST_FOUND_LOCAL. We do not need to scan for duplicate IP addresses here, | |
2372 | because set_address_from_dns() removes them. */ | |
2373 | ||
2374 | if (rc == HOST_FOUND) | |
2375 | rc = host_scan_for_local_hosts(host, &last, removed); | |
2376 | else | |
2377 | if (rc == HOST_IGNORED) rc = HOST_FIND_FAILED; /* No special action */ | |
2378 | ||
d8ef3577 PH |
2379 | /* When running in the test harness, sort into the order of addresses so as |
2380 | to get repeatability. */ | |
8e669ac1 | 2381 | |
d8ef3577 PH |
2382 | if (running_in_test_harness) sort_addresses(host, last); |
2383 | ||
059ec3d9 PH |
2384 | DEBUG(D_host_lookup) |
2385 | { | |
2386 | host_item *h; | |
2387 | if (host->address != NULL) | |
2388 | { | |
2389 | if (fully_qualified_name != NULL) | |
2390 | debug_printf("fully qualified name = %s\n", *fully_qualified_name); | |
2391 | for (h = host; h != last->next; h = h->next) | |
2392 | debug_printf("%s %s mx=%d sort=%d %s\n", h->name, | |
2393 | (h->address == NULL)? US"<null>" : h->address, h->mx, h->sort_key, | |
2394 | (h->status >= hstatus_unusable)? US"*" : US""); | |
2395 | } | |
2396 | } | |
2397 | ||
2398 | return rc; | |
2399 | } | |
2400 | ||
2401 | /* We have found one or more MX or SRV records. Sort them according to | |
2402 | precedence. Put the data for the first one into the existing host block, and | |
2403 | insert new host_item blocks into the chain for the remainder. For equal | |
2404 | precedences one is supposed to randomize the order. To make this happen, the | |
2405 | sorting is actually done on the MX value * 1000 + a random number. This is put | |
2406 | into a host field called sort_key. | |
2407 | ||
2408 | In the case of hosts with both IPv6 and IPv4 addresses, we want to choose the | |
2409 | IPv6 address in preference. At this stage, we don't know what kind of address | |
2410 | the host has. We choose a random number < 500; if later we find an A record | |
2411 | first, we add 500 to the random number. Then for any other address records, we | |
2412 | use random numbers in the range 0-499 for AAAA records and 500-999 for A | |
2413 | records. | |
2414 | ||
2415 | At this point we remove any duplicates that point to the same host, retaining | |
2416 | only the one with the lowest precedence. We cannot yet check for precedence | |
2417 | greater than that of the local host, because that test cannot be properly done | |
2418 | until the addresses have been found - an MX record may point to a name for this | |
2419 | host which is not the primary hostname. */ | |
2420 | ||
2421 | last = NULL; /* Indicates that not even the first item is filled yet */ | |
2422 | ||
2423 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS); | |
2424 | rr != NULL; | |
2425 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2426 | { | |
2427 | int precedence; | |
2428 | int weight = 0; /* For SRV records */ | |
2429 | int port = PORT_NONE; /* For SRV records */ | |
2430 | uschar *s; /* MUST be unsigned for GETSHORT */ | |
2431 | uschar data[256]; | |
2432 | ||
2433 | if (rr->type != ind_type) continue; | |
2434 | s = rr->data; | |
2435 | GETSHORT(precedence, s); /* Pointer s is advanced */ | |
2436 | ||
2437 | /* For MX records, we use a random "weight" which causes multiple records of | |
2438 | the same precedence to sort randomly. */ | |
2439 | ||
2440 | if (ind_type == T_MX) | |
2441 | { | |
2442 | weight = random_number(500); | |
2443 | } | |
2444 | ||
2445 | /* SRV records are specified with a port and a weight. The weight is used | |
2446 | in a special algorithm. However, to start with, we just use it to order the | |
2447 | records of equal priority (precedence). */ | |
2448 | ||
2449 | else | |
2450 | { | |
2451 | GETSHORT(weight, s); | |
2452 | GETSHORT(port, s); | |
2453 | } | |
2454 | ||
2455 | /* Get the name of the host pointed to. */ | |
2456 | ||
2457 | (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, s, | |
2458 | (DN_EXPAND_ARG4_TYPE)data, sizeof(data)); | |
2459 | ||
2460 | /* Check that we haven't already got this host on the chain; if we have, | |
2461 | keep only the lower precedence. This situation shouldn't occur, but you | |
2462 | never know what junk might get into the DNS (and this case has been seen on | |
2463 | more than one occasion). */ | |
2464 | ||
2465 | if (last != NULL) /* This is not the first record */ | |
2466 | { | |
2467 | host_item *prev = NULL; | |
2468 | ||
2469 | for (h = host; h != last->next; prev = h, h = h->next) | |
2470 | { | |
2471 | if (strcmpic(h->name, data) == 0) | |
2472 | { | |
2473 | DEBUG(D_host_lookup) | |
2474 | debug_printf("discarded duplicate host %s (MX=%d)\n", data, | |
2475 | (precedence > h->mx)? precedence : h->mx); | |
2476 | if (precedence >= h->mx) goto NEXT_MX_RR; /* Skip greater precedence */ | |
2477 | if (h == host) /* Override first item */ | |
2478 | { | |
2479 | h->mx = precedence; | |
2480 | host->sort_key = precedence * 1000 + weight; | |
2481 | goto NEXT_MX_RR; | |
2482 | } | |
2483 | ||
2484 | /* Unwanted host item is not the first in the chain, so we can get | |
2485 | get rid of it by cutting it out. */ | |
2486 | ||
2487 | prev->next = h->next; | |
2488 | if (h == last) last = prev; | |
2489 | break; | |
2490 | } | |
2491 | } | |
2492 | } | |
2493 | ||
2494 | /* If this is the first MX or SRV record, put the data into the existing host | |
2495 | block. Otherwise, add a new block in the correct place; if it has to be | |
2496 | before the first block, copy the first block's data to a new second block. */ | |
2497 | ||
2498 | if (last == NULL) | |
2499 | { | |
2500 | host->name = string_copy_dnsdomain(data); | |
2501 | host->address = NULL; | |
2502 | host->port = port; | |
2503 | host->mx = precedence; | |
2504 | host->sort_key = precedence * 1000 + weight; | |
2505 | host->status = hstatus_unknown; | |
2506 | host->why = hwhy_unknown; | |
2507 | last = host; | |
2508 | } | |
2509 | ||
2510 | /* Make a new host item and seek the correct insertion place */ | |
2511 | ||
2512 | else | |
2513 | { | |
2514 | int sort_key = precedence * 1000 + weight; | |
2515 | host_item *next = store_get(sizeof(host_item)); | |
2516 | next->name = string_copy_dnsdomain(data); | |
2517 | next->address = NULL; | |
2518 | next->port = port; | |
2519 | next->mx = precedence; | |
2520 | next->sort_key = sort_key; | |
2521 | next->status = hstatus_unknown; | |
2522 | next->why = hwhy_unknown; | |
2523 | next->last_try = 0; | |
2524 | ||
2525 | /* Handle the case when we have to insert before the first item. */ | |
2526 | ||
2527 | if (sort_key < host->sort_key) | |
2528 | { | |
2529 | host_item htemp; | |
2530 | htemp = *host; | |
2531 | *host = *next; | |
2532 | *next = htemp; | |
2533 | host->next = next; | |
2534 | if (last == host) last = next; | |
2535 | } | |
2536 | ||
2537 | /* Else scan down the items we have inserted as part of this exercise; | |
2538 | don't go further. */ | |
2539 | ||
2540 | else | |
2541 | { | |
2542 | for (h = host; h != last; h = h->next) | |
2543 | { | |
2544 | if (sort_key < h->next->sort_key) | |
2545 | { | |
2546 | next->next = h->next; | |
2547 | h->next = next; | |
2548 | break; | |
2549 | } | |
2550 | } | |
2551 | ||
2552 | /* Join on after the last host item that's part of this | |
2553 | processing if we haven't stopped sooner. */ | |
2554 | ||
2555 | if (h == last) | |
2556 | { | |
2557 | next->next = last->next; | |
2558 | last->next = next; | |
2559 | last = next; | |
2560 | } | |
2561 | } | |
2562 | } | |
2563 | ||
2564 | NEXT_MX_RR: continue; | |
2565 | } | |
2566 | ||
2567 | /* If the list of hosts was obtained from SRV records, there are two things to | |
2568 | do. First, if there is only one host, and it's name is ".", it means there is | |
2569 | no SMTP service at this domain. Otherwise, we have to sort the hosts of equal | |
2570 | priority according to their weights, using an algorithm that is defined in RFC | |
2571 | 2782. The hosts are currently sorted by priority and weight. For each priority | |
2572 | group we have to pick off one host and put it first, and then repeat for any | |
2573 | remaining in the same priority group. */ | |
2574 | ||
2575 | if (ind_type == T_SRV) | |
2576 | { | |
2577 | host_item **pptr; | |
2578 | ||
2579 | if (host == last && host->name[0] == 0) | |
2580 | { | |
2581 | DEBUG(D_host_lookup) debug_printf("the single SRV record is \".\"\n"); | |
2582 | return HOST_FIND_FAILED; | |
2583 | } | |
2584 | ||
2585 | DEBUG(D_host_lookup) | |
2586 | { | |
2587 | debug_printf("original ordering of hosts from SRV records:\n"); | |
2588 | for (h = host; h != last->next; h = h->next) | |
2589 | debug_printf(" %s P=%d W=%d\n", h->name, h->mx, h->sort_key % 1000); | |
2590 | } | |
2591 | ||
2592 | for (pptr = &host, h = host; h != last; pptr = &(h->next), h = h->next) | |
2593 | { | |
2594 | int sum = 0; | |
2595 | host_item *hh; | |
2596 | ||
2597 | /* Find the last following host that has the same precedence. At the same | |
2598 | time, compute the sum of the weights and the running totals. These can be | |
2599 | stored in the sort_key field. */ | |
2600 | ||
2601 | for (hh = h; hh != last; hh = hh->next) | |
2602 | { | |
2603 | int weight = hh->sort_key % 1000; /* was precedence * 1000 + weight */ | |
2604 | sum += weight; | |
2605 | hh->sort_key = sum; | |
2606 | if (hh->mx != hh->next->mx) break; | |
2607 | } | |
2608 | ||
2609 | /* If there's more than one host at this precedence (priority), we need to | |
2610 | pick one to go first. */ | |
2611 | ||
2612 | if (hh != h) | |
2613 | { | |
2614 | host_item *hhh; | |
2615 | host_item **ppptr; | |
2616 | int randomizer = random_number(sum + 1); | |
2617 | ||
2618 | for (ppptr = pptr, hhh = h; | |
2619 | hhh != hh; | |
2620 | ppptr = &(hhh->next), hhh = hhh->next) | |
2621 | { | |
2622 | if (hhh->sort_key >= randomizer) break; | |
2623 | } | |
2624 | ||
2625 | /* hhh now points to the host that should go first; ppptr points to the | |
2626 | place that points to it. Unfortunately, if the start of the minilist is | |
2627 | the start of the entire list, we can't just swap the items over, because | |
2628 | we must not change the value of host, since it is passed in from outside. | |
2629 | One day, this could perhaps be changed. | |
2630 | ||
2631 | The special case is fudged by putting the new item *second* in the chain, | |
2632 | and then transferring the data between the first and second items. We | |
2633 | can't just swap the first and the chosen item, because that would mean | |
2634 | that an item with zero weight might no longer be first. */ | |
2635 | ||
2636 | if (hhh != h) | |
2637 | { | |
2638 | *ppptr = hhh->next; /* Cuts it out of the chain */ | |
2639 | ||
2640 | if (h == host) | |
2641 | { | |
2642 | host_item temp = *h; | |
2643 | *h = *hhh; | |
2644 | *hhh = temp; | |
2645 | hhh->next = temp.next; | |
2646 | h->next = hhh; | |
2647 | } | |
2648 | ||
2649 | else | |
2650 | { | |
2651 | hhh->next = h; /* The rest of the chain follows it */ | |
2652 | *pptr = hhh; /* It takes the place of h */ | |
2653 | h = hhh; /* It's now the start of this minilist */ | |
2654 | } | |
2655 | } | |
2656 | } | |
2657 | ||
2658 | /* A host has been chosen to be first at this priority and h now points | |
2659 | to this host. There may be others at the same priority, or others at a | |
2660 | different priority. Before we leave this host, we need to put back a sort | |
2661 | key of the traditional MX kind, in case this host is multihomed, because | |
2662 | the sort key is used for ordering the multiple IP addresses. We do not need | |
2663 | to ensure that these new sort keys actually reflect the order of the hosts, | |
2664 | however. */ | |
2665 | ||
2666 | h->sort_key = h->mx * 1000 + random_number(500); | |
2667 | } /* Move on to the next host */ | |
2668 | } | |
2669 | ||
2670 | /* Now we have to ensure addresses exist for all the hosts. We have ensured | |
2671 | above that the names in the host items are all unique. The addresses may have | |
2672 | been returned in the additional data section of the DNS query. Because it is | |
2673 | more expensive to scan the returned DNS records (because you have to expand the | |
2674 | names) we do a single scan over them, and multiple scans of the chain of host | |
2675 | items (which is typically only 3 or 4 long anyway.) Add extra host items for | |
2676 | multi-homed hosts. */ | |
2677 | ||
2678 | for (rr = dns_next_rr(&dnsa, &dnss, RESET_ADDITIONAL); | |
2679 | rr != NULL; | |
2680 | rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) | |
2681 | { | |
2682 | dns_address *da; | |
2683 | int status = hstatus_unknown; | |
2684 | int why = hwhy_unknown; | |
2685 | int randoffset; | |
2686 | ||
2687 | if (rr->type != T_A | |
2688 | #if HAVE_IPV6 | |
2689 | && rr->type != T_AAAA | |
2690 | #ifdef SUPPORT_A6 | |
2691 | && rr->type != T_A6 | |
2692 | #endif | |
2693 | #endif | |
2694 | ) continue; | |
2695 | ||
2696 | /* Find the first host that matches this record's name. If there isn't | |
2697 | one, move on to the next RR. */ | |
2698 | ||
2699 | for (h = host; h != last->next; h = h->next) | |
2700 | { if (strcmpic(h->name, rr->name) == 0) break; } | |
2701 | if (h == last->next) continue; | |
2702 | ||
2703 | /* For IPv4 addresses, add 500 to the random part of the sort key, to ensure | |
2704 | they sort after IPv6 addresses. */ | |
2705 | ||
2706 | randoffset = (rr->type == T_A)? 500 : 0; | |
2707 | ||
2708 | /* Get the list of textual addresses for this RR. There may be more than one | |
2709 | if it is an A6 RR. Then loop to handle multiple addresses from an A6 record. | |
2710 | If there are none, nothing will get done - the record is ignored. */ | |
2711 | ||
2712 | for (da = dns_address_from_rr(&dnsa, rr); da != NULL; da = da->next) | |
2713 | { | |
2714 | /* Set status for an ignorable host. */ | |
2715 | ||
2716 | #ifndef STAND_ALONE | |
2717 | if (ignore_target_hosts != NULL && | |
2718 | verify_check_this_host(&ignore_target_hosts, NULL, h->name, | |
2719 | da->address, NULL) == OK) | |
2720 | { | |
2721 | DEBUG(D_host_lookup) | |
2722 | debug_printf("ignored host %s [%s]\n", h->name, da->address); | |
2723 | status = hstatus_unusable; | |
2724 | why = hwhy_ignored; | |
2725 | } | |
2726 | #endif | |
2727 | ||
2728 | /* If the address is already set for this host, it may be that | |
2729 | we just have a duplicate DNS record. Alternatively, this may be | |
2730 | a multi-homed host. Search all items with the same host name | |
2731 | (they will all be together) and if this address is found, skip | |
2732 | to the next RR. */ | |
2733 | ||
2734 | if (h->address != NULL) | |
2735 | { | |
2736 | int new_sort_key; | |
2737 | host_item *thishostlast; | |
2738 | host_item *hh = h; | |
2739 | ||
2740 | do | |
2741 | { | |
2742 | if (hh->address != NULL && Ustrcmp(CS da->address, hh->address) == 0) | |
2743 | goto DNS_NEXT_RR; /* Need goto to escape from inner loop */ | |
2744 | thishostlast = hh; | |
2745 | hh = hh->next; | |
2746 | } | |
2747 | while (hh != last->next && strcmpic(hh->name, rr->name) == 0); | |
2748 | ||
2749 | /* We have a multi-homed host, since we have a new address for | |
2750 | an existing name. Create a copy of the current item, and give it | |
2751 | the new address. RRs can be in arbitrary order, but one is supposed | |
2752 | to randomize the addresses of multi-homed hosts, so compute a new | |
2753 | sorting key and do that. [Latest SMTP RFC says not to randomize multi- | |
2754 | homed hosts, but to rely on the resolver. I'm not happy about that - | |
2755 | caching in the resolver will not rotate as often as the name server | |
2756 | does.] */ | |
2757 | ||
2758 | new_sort_key = h->mx * 1000 + random_number(500) + randoffset; | |
2759 | hh = store_get(sizeof(host_item)); | |
2760 | ||
2761 | /* New address goes first: insert the new block after the first one | |
2762 | (so as not to disturb the original pointer) but put the new address | |
2763 | in the original block. */ | |
2764 | ||
2765 | if (new_sort_key < h->sort_key) | |
2766 | { | |
2767 | *hh = *h; /* Note: copies the port */ | |
2768 | h->next = hh; | |
2769 | h->address = da->address; | |
2770 | h->sort_key = new_sort_key; | |
2771 | h->status = status; | |
2772 | h->why = why; | |
2773 | } | |
2774 | ||
2775 | /* Otherwise scan down the addresses for this host to find the | |
2776 | one to insert after. */ | |
2777 | ||
2778 | else | |
2779 | { | |
2780 | while (h != thishostlast) | |
2781 | { | |
2782 | if (new_sort_key < h->next->sort_key) break; | |
2783 | h = h->next; | |
2784 | } | |
2785 | *hh = *h; /* Note: copies the port */ | |
2786 | h->next = hh; | |
2787 | hh->address = da->address; | |
2788 | hh->sort_key = new_sort_key; | |
2789 | hh->status = status; | |
2790 | hh->why = why; | |
2791 | } | |
2792 | ||
2793 | if (h == last) last = hh; /* Inserted after last */ | |
2794 | } | |
2795 | ||
2796 | /* The existing item doesn't have its address set yet, so just set it. | |
2797 | Ensure that an IPv4 address gets its sort key incremented in case an IPv6 | |
2798 | address is found later. */ | |
2799 | ||
2800 | else | |
2801 | { | |
2802 | h->address = da->address; /* Port should be set already */ | |
2803 | h->status = status; | |
2804 | h->why = why; | |
2805 | h->sort_key += randoffset; | |
2806 | } | |
2807 | } /* Loop for addresses extracted from one RR */ | |
2808 | ||
2809 | /* Carry on to the next RR. It would be nice to be able to be able to stop | |
2810 | when every host on the list has an address, but we can't be sure there won't | |
2811 | be an additional address for a multi-homed host further down the list, so | |
2812 | we have to continue to the end. */ | |
2813 | ||
2814 | DNS_NEXT_RR: continue; | |
2815 | } | |
2816 | ||
2817 | /* Set the default yield to failure */ | |
2818 | ||
2819 | yield = HOST_FIND_FAILED; | |
2820 | ||
2821 | /* If we haven't found all the addresses in the additional section, we | |
2822 | need to search for A or AAAA records explicitly. The names shouldn't point to | |
2823 | CNAMES, but we use the general lookup function that handles them, just | |
2824 | in case. If any lookup gives a soft error, change the default yield. | |
2825 | ||
2826 | For these DNS lookups, we must disable qualify_single and search_parents; | |
2827 | otherwise invalid host names obtained from MX or SRV records can cause trouble | |
2828 | if they happen to match something local. */ | |
2829 | ||
2830 | dns_init(FALSE, FALSE); | |
2831 | ||
2832 | for (h = host; h != last->next; h = h->next) | |
2833 | { | |
2834 | if (h->address != NULL || h->status == hstatus_unusable) continue; | |
2835 | rc = set_address_from_dns(h, &last, ignore_target_hosts, allow_mx_to_ip, NULL); | |
2836 | if (rc != HOST_FOUND) | |
2837 | { | |
2838 | h->status = hstatus_unusable; | |
2839 | if (rc == HOST_FIND_AGAIN) | |
2840 | { | |
2841 | yield = rc; | |
2842 | h->why = hwhy_deferred; | |
2843 | } | |
2844 | else | |
2845 | h->why = (rc == HOST_IGNORED)? hwhy_ignored : hwhy_failed; | |
2846 | } | |
2847 | } | |
2848 | ||
2849 | /* Scan the list for any hosts that are marked unusable because they have | |
2850 | been explicitly ignored, and remove them from the list, as if they did not | |
2851 | exist. If we end up with just a single, ignored host, flatten its fields as if | |
2852 | nothing was found. */ | |
2853 | ||
2854 | if (ignore_target_hosts != NULL) | |
2855 | { | |
2856 | host_item *prev = NULL; | |
2857 | for (h = host; h != last->next; h = h->next) | |
2858 | { | |
2859 | REDO: | |
2860 | if (h->why != hwhy_ignored) /* Non ignored host, just continue */ | |
2861 | prev = h; | |
2862 | else if (prev == NULL) /* First host is ignored */ | |
2863 | { | |
2864 | if (h != last) /* First is not last */ | |
2865 | { | |
2866 | if (h->next == last) last = h; /* Overwrite it with next */ | |
2867 | *h = *(h->next); /* and reprocess it. */ | |
2868 | goto REDO; /* C should have redo, like Perl */ | |
2869 | } | |
2870 | } | |
2871 | else /* Ignored host is not first - */ | |
2872 | { /* cut it out */ | |
2873 | prev->next = h->next; | |
2874 | if (h == last) last = prev; | |
2875 | } | |
2876 | } | |
2877 | ||
2878 | if (host->why == hwhy_ignored) host->address = NULL; | |
2879 | } | |
2880 | ||
2881 | /* There is still one complication in the case of IPv6. Although the code above | |
2882 | arranges that IPv6 addresses take precedence over IPv4 addresses for multihomed | |
2883 | hosts, it doesn't do this for addresses that apply to different hosts with the | |
2884 | same MX precedence, because the sorting on MX precedence happens first. So we | |
2885 | have to make another pass to check for this case. We ensure that, within a | |
2886 | single MX preference value, IPv6 addresses come first. This can separate the | |
2887 | addresses of a multihomed host, but that should not matter. */ | |
2888 | ||
2889 | #if HAVE_IPV6 | |
2890 | if (h != last) | |
2891 | { | |
2892 | for (h = host; h != last; h = h->next) | |
2893 | { | |
2894 | host_item temp; | |
2895 | host_item *next = h->next; | |
2896 | if (h->mx != next->mx || /* If next is different MX value */ | |
2897 | (h->sort_key % 1000) < 500 || /* OR this one is IPv6 */ | |
2898 | (next->sort_key % 1000) >= 500) /* OR next is IPv4 */ | |
2899 | continue; /* move on to next */ | |
2900 | temp = *h; | |
2901 | temp.next = next->next; | |
2902 | *h = *next; | |
2903 | h->next = next; | |
2904 | *next = temp; | |
2905 | } | |
2906 | } | |
2907 | #endif | |
2908 | ||
2909 | /* When running in the test harness, we want the hosts always to be in the same | |
2910 | order so that the debugging output is the same and can be compared. Having a | |
2911 | fixed set of "random" numbers doesn't actually achieve this, because the RRs | |
2912 | come back from the resolver in a random order, so the non-random random numbers | |
2913 | get used in a different order. We therefore have to sort the hosts that have | |
2914 | the same MX values. We chose do to this by their name and then by IP address. | |
2915 | The fact that the sort is slow matters not - this is testing only! */ | |
2916 | ||
2917 | if (running_in_test_harness) | |
2918 | { | |
2919 | BOOL done; | |
2920 | do | |
2921 | { | |
2922 | done = TRUE; | |
2923 | for (h = host; h != last; h = h->next) | |
2924 | { | |
2925 | int c = Ustrcmp(h->name, h->next->name); | |
2926 | if (c == 0) c = Ustrcmp(h->address, h->next->address); | |
2927 | if (h->mx == h->next->mx && c > 0) | |
2928 | { | |
2929 | host_item *next = h->next; | |
2930 | host_item temp = *h; | |
2931 | temp.next = next->next; | |
2932 | *h = *next; | |
2933 | h->next = next; | |
2934 | *next = temp; | |
2935 | done = FALSE; | |
2936 | } | |
2937 | } | |
2938 | } | |
2939 | while (!done); | |
2940 | } | |
2941 | ||
2942 | /* Remove any duplicate IP addresses and then scan the list of hosts for any | |
2943 | whose IP addresses are on the local host. If any are found, all hosts with the | |
2944 | same or higher MX values are removed. However, if the local host has the lowest | |
2945 | numbered MX, then HOST_FOUND_LOCAL is returned. Otherwise, if at least one host | |
2946 | with an IP address is on the list, HOST_FOUND is returned. Otherwise, | |
2947 | HOST_FIND_FAILED is returned, but in this case do not update the yield, as it | |
2948 | might have been set to HOST_FIND_AGAIN just above here. If not, it will already | |
2949 | be HOST_FIND_FAILED. */ | |
2950 | ||
2951 | host_remove_duplicates(host, &last); | |
2952 | rc = host_scan_for_local_hosts(host, &last, removed); | |
2953 | if (rc != HOST_FIND_FAILED) yield = rc; | |
2954 | ||
2955 | DEBUG(D_host_lookup) | |
2956 | { | |
2957 | if (fully_qualified_name != NULL) | |
2958 | debug_printf("fully qualified name = %s\n", *fully_qualified_name); | |
2959 | debug_printf("host_find_bydns yield = %s (%d); returned hosts:\n", | |
2960 | (yield == HOST_FOUND)? "HOST_FOUND" : | |
2961 | (yield == HOST_FOUND_LOCAL)? "HOST_FOUND_LOCAL" : | |
2962 | (yield == HOST_FIND_AGAIN)? "HOST_FIND_AGAIN" : | |
2963 | (yield == HOST_FIND_FAILED)? "HOST_FIND_FAILED" : "?", | |
2964 | yield); | |
2965 | for (h = host; h != last->next; h = h->next) | |
2966 | { | |
2967 | debug_printf(" %s %s MX=%d ", h->name, | |
2968 | (h->address == NULL)? US"<null>" : h->address, h->mx); | |
2969 | if (h->port != PORT_NONE) debug_printf("port=%d ", h->port); | |
2970 | if (h->status >= hstatus_unusable) debug_printf("*"); | |
2971 | debug_printf("\n"); | |
2972 | } | |
2973 | } | |
2974 | ||
2975 | return yield; | |
2976 | } | |
2977 | ||
2978 | ||
2979 | ||
2980 | ||
2981 | /************************************************* | |
2982 | ************************************************** | |
2983 | * Stand-alone test program * | |
2984 | ************************************************** | |
2985 | *************************************************/ | |
2986 | ||
2987 | #ifdef STAND_ALONE | |
2988 | ||
2989 | BOOL alldigits(uschar *buffer) | |
2990 | { | |
2991 | if (!isdigit(*buffer)) return FALSE; | |
2992 | if (*buffer == '0' && buffer[1] == 'x') | |
2993 | { | |
2994 | buffer++; | |
2995 | while (isxdigit(*(++buffer))); | |
2996 | } | |
2997 | else while (isdigit(*(++buffer))); | |
2998 | return (*buffer == 0); | |
2999 | } | |
3000 | ||
3001 | int main(int argc, char **cargv) | |
3002 | { | |
3003 | host_item h; | |
3004 | int whichrrs = HOST_FIND_BY_MX | HOST_FIND_BY_A; | |
3005 | BOOL byname = FALSE; | |
3006 | BOOL qualify_single = TRUE; | |
3007 | BOOL search_parents = FALSE; | |
3008 | uschar **argv = USS cargv; | |
3009 | uschar buffer[256]; | |
3010 | ||
3011 | primary_hostname = US""; | |
3012 | store_pool = POOL_MAIN; | |
3013 | debug_selector = D_host_lookup|D_interface; | |
3014 | debug_file = stdout; | |
3015 | debug_fd = fileno(debug_file); | |
3016 | ||
3017 | printf("Exim stand-alone host functions test\n"); | |
3018 | ||
3019 | host_find_interfaces(); | |
3020 | debug_selector = D_host_lookup | D_dns; | |
3021 | ||
3022 | if (argc > 1) primary_hostname = argv[1]; | |
3023 | ||
3024 | /* So that debug level changes can be done first */ | |
3025 | ||
3026 | dns_init(qualify_single, search_parents); | |
3027 | ||
3028 | printf("Testing host lookup\n"); | |
3029 | printf("> "); | |
3030 | while (Ufgets(buffer, 256, stdin) != NULL) | |
3031 | { | |
3032 | int rc; | |
3033 | int len = Ustrlen(buffer); | |
3034 | uschar *fully_qualified_name; | |
3035 | ||
3036 | while (len > 0 && isspace(buffer[len-1])) len--; | |
3037 | buffer[len] = 0; | |
3038 | ||
3039 | if (Ustrcmp(buffer, "q") == 0) break; | |
3040 | ||
3041 | if (Ustrcmp(buffer, "byname") == 0) byname = TRUE; | |
3042 | else if (Ustrcmp(buffer, "no_byname") == 0) byname = FALSE; | |
3043 | else if (Ustrcmp(buffer, "a_only") == 0) whichrrs = HOST_FIND_BY_A; | |
3044 | else if (Ustrcmp(buffer, "mx_only") == 0) whichrrs = HOST_FIND_BY_MX; | |
3045 | else if (Ustrcmp(buffer, "srv_only") == 0) whichrrs = HOST_FIND_BY_SRV; | |
3046 | else if (Ustrcmp(buffer, "srv+a") == 0) | |
3047 | whichrrs = HOST_FIND_BY_SRV | HOST_FIND_BY_A; | |
3048 | else if (Ustrcmp(buffer, "srv+mx") == 0) | |
3049 | whichrrs = HOST_FIND_BY_SRV | HOST_FIND_BY_MX; | |
3050 | else if (Ustrcmp(buffer, "srv+mx+a") == 0) | |
3051 | whichrrs = HOST_FIND_BY_SRV | HOST_FIND_BY_MX | HOST_FIND_BY_A; | |
3052 | else if (Ustrcmp(buffer, "qualify_single") == 0) qualify_single = TRUE; | |
3053 | else if (Ustrcmp(buffer, "no_qualify_single") == 0) qualify_single = FALSE; | |
3054 | else if (Ustrcmp(buffer, "search_parents") == 0) search_parents = TRUE; | |
3055 | else if (Ustrcmp(buffer, "no_search_parents") == 0) search_parents = FALSE; | |
3056 | else if (Ustrncmp(buffer, "retrans", 7) == 0) | |
3057 | { | |
ff790e47 | 3058 | (void)sscanf(CS(buffer+8), "%d", &dns_retrans); |
059ec3d9 PH |
3059 | _res.retrans = dns_retrans; |
3060 | } | |
3061 | else if (Ustrncmp(buffer, "retry", 5) == 0) | |
3062 | { | |
ff790e47 | 3063 | (void)sscanf(CS(buffer+6), "%d", &dns_retry); |
059ec3d9 PH |
3064 | _res.retry = dns_retry; |
3065 | } | |
3066 | else if (alldigits(buffer)) | |
3067 | { | |
3068 | debug_selector = Ustrtol(buffer, NULL, 0); | |
3069 | _res.options &= ~RES_DEBUG; | |
3070 | DEBUG(D_resolver) _res.options |= RES_DEBUG; | |
3071 | } | |
3072 | else | |
3073 | { | |
3074 | int flags = whichrrs; | |
3075 | ||
3076 | h.name = buffer; | |
3077 | h.next = NULL; | |
3078 | h.mx = MX_NONE; | |
3079 | h.port = PORT_NONE; | |
3080 | h.status = hstatus_unknown; | |
3081 | h.why = hwhy_unknown; | |
3082 | h.address = NULL; | |
3083 | ||
3084 | if (qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE; | |
3085 | if (search_parents) flags |= HOST_FIND_SEARCH_PARENTS; | |
3086 | ||
3087 | rc = byname? | |
3088 | host_find_byname(&h, NULL, &fully_qualified_name, TRUE) | |
3089 | : | |
3090 | host_find_bydns(&h, NULL, flags, US"smtp", NULL, NULL, | |
3091 | &fully_qualified_name, NULL); | |
3092 | ||
3093 | if (rc == HOST_FIND_FAILED) printf("Failed\n"); | |
3094 | else if (rc == HOST_FIND_AGAIN) printf("Again\n"); | |
3095 | else if (rc == HOST_FOUND_LOCAL) printf("Local\n"); | |
3096 | } | |
3097 | ||
3098 | printf("\n> "); | |
3099 | } | |
3100 | ||
3101 | printf("Testing host_aton\n"); | |
3102 | printf("> "); | |
3103 | while (Ufgets(buffer, 256, stdin) != NULL) | |
3104 | { | |
3105 | int i; | |
3106 | int x[4]; | |
3107 | int len = Ustrlen(buffer); | |
3108 | ||
3109 | while (len > 0 && isspace(buffer[len-1])) len--; | |
3110 | buffer[len] = 0; | |
3111 | ||
3112 | if (Ustrcmp(buffer, "q") == 0) break; | |
3113 | ||
3114 | len = host_aton(buffer, x); | |
3115 | printf("length = %d ", len); | |
3116 | for (i = 0; i < len; i++) | |
3117 | { | |
3118 | printf("%04x ", (x[i] >> 16) & 0xffff); | |
3119 | printf("%04x ", x[i] & 0xffff); | |
3120 | } | |
3121 | printf("\n> "); | |
3122 | } | |
3123 | ||
3124 | printf("\n"); | |
3125 | ||
3126 | printf("Testing host_name_lookup\n"); | |
3127 | printf("> "); | |
3128 | while (Ufgets(buffer, 256, stdin) != NULL) | |
3129 | { | |
3130 | int len = Ustrlen(buffer); | |
3131 | while (len > 0 && isspace(buffer[len-1])) len--; | |
3132 | buffer[len] = 0; | |
3133 | if (Ustrcmp(buffer, "q") == 0) break; | |
3134 | sender_host_address = buffer; | |
3135 | sender_host_name = NULL; | |
3136 | sender_host_aliases = NULL; | |
3137 | host_lookup_msg = US""; | |
3138 | host_lookup_failed = FALSE; | |
3139 | if (host_name_lookup() == FAIL) /* Debug causes printing */ | |
3140 | printf("Lookup failed:%s\n", host_lookup_msg); | |
3141 | printf("\n> "); | |
3142 | } | |
3143 | ||
3144 | printf("\n"); | |
3145 | ||
3146 | return 0; | |
3147 | } | |
3148 | #endif /* STAND_ALONE */ | |
3149 | ||
3150 | /* End of host.c */ |