/[svn]/ircd-hybrid-7.2/src/irc_res.c
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Contents of /ircd-hybrid-7.2/src/irc_res.c

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Revision 995 - (show annotations)
Fri Aug 21 10:11:14 2009 UTC (10 years, 5 months ago) by michael
File MIME type: text/x-chdr
File size: 23025 byte(s)
- remove add_local_domain

1 /*
2 * A rewrite of Darren Reeds original res.c As there is nothing
3 * left of Darrens original code, this is now licensed by the hybrid group.
4 * (Well, some of the function names are the same, and bits of the structs..)
5 * You can use it where it is useful, free even. Buy us a beer and stuff.
6 *
7 * The authors takes no responsibility for any damage or loss
8 * of property which results from the use of this software.
9 *
10 * $Id$
11 *
12 * July 1999 - Rewrote a bunch of stuff here. Change hostent builder code,
13 * added callbacks and reference counting of returned hostents.
14 * --Bleep (Thomas Helvey <tomh@inxpress.net>)
15 *
16 * This was all needlessly complicated for irc. Simplified. No more hostent
17 * All we really care about is the IP -> hostname mappings. Thats all.
18 *
19 * Apr 28, 2003 --cryogen and Dianora
20 */
21
22 #include "stdinc.h"
23 #include "tools.h"
24 #include "client.h"
25 #include "list.h"
26 #include "common.h"
27 #include "event.h"
28 #include "irc_string.h"
29 #include "sprintf_irc.h"
30 #include "ircd.h"
31 #include "numeric.h"
32 #include "restart.h"
33 #include "rng_mt.h"
34 #include "fdlist.h"
35 #include "fileio.h" /* for fbopen / fbclose / fbputs */
36 #include "s_bsd.h"
37 #include "s_log.h"
38 #include "send.h"
39 #include "memory.h"
40 #include "irc_res.h"
41 #include "irc_reslib.h"
42 #include "irc_getnameinfo.h"
43
44 #if (CHAR_BIT != 8)
45 #error this code needs to be able to address individual octets
46 #endif
47
48 static PF res_readreply;
49
50 #define MAXPACKET 1024 /* rfc sez 512 but we expand names so ... */
51 #define RES_MAXALIASES 35 /* maximum aliases allowed */
52 #define RES_MAXADDRS 35 /* maximum addresses allowed */
53 #define AR_TTL 600 /* TTL in seconds for dns cache entries */
54
55 /* RFC 1104/1105 wasn't very helpful about what these fields
56 * should be named, so for now, we'll just name them this way.
57 * we probably should look at what named calls them or something.
58 */
59 #define TYPE_SIZE (size_t)2
60 #define CLASS_SIZE (size_t)2
61 #define TTL_SIZE (size_t)4
62 #define RDLENGTH_SIZE (size_t)2
63 #define ANSWER_FIXED_SIZE (TYPE_SIZE + CLASS_SIZE + TTL_SIZE + RDLENGTH_SIZE)
64
65 typedef enum
66 {
67 REQ_IDLE, /* We're doing not much at all */
68 REQ_PTR, /* Looking up a PTR */
69 REQ_A, /* Looking up an A, possibly because AAAA failed */
70 #ifdef IPV6
71 REQ_AAAA, /* Looking up an AAAA */
72 #endif
73 REQ_CNAME /* We got a CNAME in response, we better get a real answer next */
74 } request_state;
75
76 struct reslist
77 {
78 dlink_node node;
79 int id;
80 int sent; /* number of requests sent */
81 request_state state; /* State the resolver machine is in */
82 time_t ttl;
83 char type;
84 char retries; /* retry counter */
85 char sends; /* number of sends (>1 means resent) */
86 char resend; /* send flag. 0 == dont resend */
87 time_t sentat;
88 time_t timeout;
89 struct irc_ssaddr addr;
90 char *name;
91 dns_callback_fnc callback;
92 void *callback_ctx;
93 };
94
95 static fde_t ResolverFileDescriptor;
96 static dlink_list request_list = { NULL, NULL, 0 };
97
98 static void rem_request(struct reslist *request);
99 static struct reslist *make_request(dns_callback_fnc callback, void *);
100 static void do_query_name(dns_callback_fnc callback, void *,
101 const char *, struct reslist *, int);
102 static void do_query_number(dns_callback_fnc callback, void *ctx,
103 const struct irc_ssaddr *,
104 struct reslist *request);
105 static void query_name(const char *name, int query_class, int query_type,
106 struct reslist *request);
107 static int send_res_msg(const char *buf, int len, int count);
108 static void resend_query(struct reslist *request);
109 static int proc_answer(struct reslist *request, HEADER *header, char *, char *);
110 static struct reslist *find_id(int id);
111
112
113 /*
114 * int
115 * res_ourserver(inp)
116 * looks up "inp" in irc_nsaddr_list[]
117 * returns:
118 * 0 : not found
119 * >0 : found
120 * author:
121 * paul vixie, 29may94
122 * revised for ircd, cryogen(stu) may03
123 */
124 static int
125 res_ourserver(const struct irc_ssaddr *inp)
126 {
127 #ifdef IPV6
128 const struct sockaddr_in6 *v6;
129 const struct sockaddr_in6 *v6in = (const struct sockaddr_in6 *)inp;
130 #endif
131 const struct sockaddr_in *v4;
132 const struct sockaddr_in *v4in = (const struct sockaddr_in *)inp;
133 int ns;
134
135 for (ns = 0; ns < irc_nscount; ns++)
136 {
137 const struct irc_ssaddr *srv = &irc_nsaddr_list[ns];
138 #ifdef IPV6
139 v6 = (const struct sockaddr_in6 *)srv;
140 #endif
141 v4 = (const struct sockaddr_in *)srv;
142
143 /* could probably just memcmp(srv, inp, srv.ss_len) here
144 * but we'll air on the side of caution - stu
145 *
146 */
147 switch (srv->ss.ss_family)
148 {
149 #ifdef IPV6
150 case AF_INET6:
151 if (srv->ss.ss_family == inp->ss.ss_family)
152 if (v6->sin6_port == v6in->sin6_port)
153 if ((memcmp(&v6->sin6_addr.s6_addr, &v6in->sin6_addr.s6_addr,
154 sizeof(struct in6_addr)) == 0) ||
155 (memcmp(&v6->sin6_addr.s6_addr, &in6addr_any,
156 sizeof(struct in6_addr)) == 0))
157 return(1);
158 break;
159 #endif
160 case AF_INET:
161 if (srv->ss.ss_family == inp->ss.ss_family)
162 if (v4->sin_port == v4in->sin_port)
163 if ((v4->sin_addr.s_addr == INADDR_ANY) ||
164 (v4->sin_addr.s_addr == v4in->sin_addr.s_addr))
165 return(1);
166 break;
167 default:
168 break;
169 }
170 }
171
172 return(0);
173 }
174
175 /*
176 * timeout_query_list - Remove queries from the list which have been
177 * there too long without being resolved.
178 */
179 static time_t
180 timeout_query_list(time_t now)
181 {
182 dlink_node *ptr;
183 dlink_node *next_ptr;
184 struct reslist *request;
185 time_t next_time = 0;
186 time_t timeout = 0;
187
188 DLINK_FOREACH_SAFE(ptr, next_ptr, request_list.head)
189 {
190 request = ptr->data;
191 timeout = request->sentat + request->timeout;
192
193 if (now >= timeout)
194 {
195 if (--request->retries <= 0)
196 {
197 (*request->callback)(request->callback_ctx, NULL, NULL);
198 rem_request(request);
199 continue;
200 }
201 else
202 {
203 request->sentat = now;
204 request->timeout += request->timeout;
205 resend_query(request);
206 }
207 }
208
209 if ((next_time == 0) || timeout < next_time)
210 {
211 next_time = timeout;
212 }
213 }
214
215 return((next_time > now) ? next_time : (now + AR_TTL));
216 }
217
218 /*
219 * timeout_resolver - check request list
220 */
221 static void
222 timeout_resolver(void *notused)
223 {
224 timeout_query_list(CurrentTime);
225 }
226
227 /*
228 * start_resolver - do everything we need to read the resolv.conf file
229 * and initialize the resolver file descriptor if needed
230 */
231 static void
232 start_resolver(void)
233 {
234 irc_res_init();
235
236 if (!ResolverFileDescriptor.flags.open)
237 {
238 if (comm_open(&ResolverFileDescriptor, irc_nsaddr_list[0].ss.ss_family,
239 SOCK_DGRAM, 0, "Resolver socket") == -1)
240 return;
241
242 /* At the moment, the resolver FD data is global .. */
243 comm_setselect(&ResolverFileDescriptor, COMM_SELECT_READ,
244 res_readreply, NULL, 0);
245 eventAdd("timeout_resolver", timeout_resolver, NULL, 1);
246 }
247 }
248
249 /*
250 * init_resolver - initialize resolver and resolver library
251 */
252 void
253 init_resolver(void)
254 {
255 memset(&ResolverFileDescriptor, 0, sizeof(fde_t));
256 start_resolver();
257 }
258
259 /*
260 * restart_resolver - reread resolv.conf, reopen socket
261 */
262 void
263 restart_resolver(void)
264 {
265 fd_close(&ResolverFileDescriptor);
266 eventDelete(timeout_resolver, NULL); /* -ddosen */
267 start_resolver();
268 }
269
270 /*
271 * rem_request - remove a request from the list.
272 * This must also free any memory that has been allocated for
273 * temporary storage of DNS results.
274 */
275 static void
276 rem_request(struct reslist *request)
277 {
278 dlinkDelete(&request->node, &request_list);
279 MyFree(request->name);
280 MyFree(request);
281 }
282
283 /*
284 * make_request - Create a DNS request record for the server.
285 */
286 static struct reslist *
287 make_request(dns_callback_fnc callback, void *ctx)
288 {
289 struct reslist *request;
290
291 request = (struct reslist *)MyMalloc(sizeof(struct reslist));
292
293 request->sentat = CurrentTime;
294 request->retries = 3;
295 request->resend = 1;
296 request->timeout = 4; /* start at 4 and exponential inc. */
297 request->state = REQ_IDLE;
298 request->callback = callback;
299 request->callback_ctx = ctx;
300
301 dlinkAdd(request, &request->node, &request_list);
302 return(request);
303 }
304
305 /*
306 * delete_resolver_queries - cleanup outstanding queries
307 * for which there no longer exist clients or conf lines.
308 */
309 void
310 delete_resolver_queries(const void *vptr)
311 {
312 dlink_node *ptr;
313 dlink_node *next_ptr;
314 struct reslist *request;
315
316 DLINK_FOREACH_SAFE(ptr, next_ptr, request_list.head)
317 {
318 if ((request = ptr->data) != NULL)
319 {
320 if (request->callback_ctx == vptr)
321 rem_request(request);
322 }
323 }
324 }
325
326 /*
327 * send_res_msg - sends msg to all nameservers found in the "_res" structure.
328 * This should reflect /etc/resolv.conf. We will get responses
329 * which arent needed but is easier than checking to see if nameserver
330 * isnt present. Returns number of messages successfully sent to
331 * nameservers or -1 if no successful sends.
332 */
333 static int
334 send_res_msg(const char *msg, int len, int rcount)
335 {
336 int i;
337 int sent = 0;
338 int max_queries = IRCD_MIN(irc_nscount, rcount);
339
340 /* RES_PRIMARY option is not implemented
341 * if (res.options & RES_PRIMARY || 0 == max_queries)
342 */
343 if (max_queries == 0)
344 max_queries = 1;
345
346 for (i = 0; i < max_queries; i++)
347 {
348 if (sendto(ResolverFileDescriptor.fd, msg, len, 0,
349 (struct sockaddr*)&(irc_nsaddr_list[i]),
350 irc_nsaddr_list[i].ss_len) == len)
351 ++sent;
352 }
353
354 return(sent);
355 }
356
357 /*
358 * find_id - find a dns request id (id is determined by dn_mkquery)
359 */
360 static struct reslist *
361 find_id(int id)
362 {
363 dlink_node *ptr;
364 struct reslist *request;
365
366 DLINK_FOREACH(ptr, request_list.head)
367 {
368 request = ptr->data;
369
370 if (request->id == id)
371 return(request);
372 }
373
374 return(NULL);
375 }
376
377 /*
378 * gethost_byname_type - get host address from name
379 *
380 */
381 void
382 gethost_byname_type(dns_callback_fnc callback, void *ctx, const char *name, int type)
383 {
384 assert(name != 0);
385 do_query_name(callback, ctx, name, NULL, type);
386 }
387
388 /*
389 * gethost_byname - wrapper for _type - send T_AAAA first if IPV6 supported
390 */
391 void
392 gethost_byname(dns_callback_fnc callback, void *ctx, const char *name)
393 {
394 #ifdef IPV6
395 gethost_byname_type(callback, ctx, name, T_AAAA);
396 #else
397 gethost_byname_type(callback, ctx, name, T_A);
398 #endif
399 }
400
401 /*
402 * gethost_byaddr - get host name from address
403 */
404 void
405 gethost_byaddr(dns_callback_fnc callback, void *ctx, const struct irc_ssaddr *addr)
406 {
407 do_query_number(callback, ctx, addr, NULL);
408 }
409
410 /*
411 * do_query_name - nameserver lookup name
412 */
413 static void
414 do_query_name(dns_callback_fnc callback, void *ctx, const char *name,
415 struct reslist *request, int type)
416 {
417 char host_name[HOSTLEN + 1];
418
419 strlcpy(host_name, name, sizeof(hostname));
420
421 if (request == NULL)
422 {
423 request = make_request(callback, ctx);
424 request->name = MyMalloc(strlen(host_name) + 1);
425 request->type = type;
426 strcpy(request->name, host_name);
427 #ifdef IPV6
428 if (type != T_A)
429 request->state = REQ_AAAA;
430 else
431 #endif
432 request->state = REQ_A;
433 }
434
435 request->type = type;
436 query_name(host_name, C_IN, type, request);
437 }
438
439 /*
440 * do_query_number - Use this to do reverse IP# lookups.
441 */
442 static void
443 do_query_number(dns_callback_fnc callback, void *ctx,
444 const struct irc_ssaddr *addr,
445 struct reslist *request)
446 {
447 char ipbuf[128];
448 const unsigned char *cp;
449
450 if (addr->ss.ss_family == AF_INET)
451 {
452 const struct sockaddr_in *v4 = (const struct sockaddr_in *)addr;
453 cp = (const unsigned char*)&v4->sin_addr.s_addr;
454
455 ircsprintf(ipbuf, "%u.%u.%u.%u.in-addr.arpa.",
456 (unsigned int)(cp[3]), (unsigned int)(cp[2]),
457 (unsigned int)(cp[1]), (unsigned int)(cp[0]));
458 }
459 #ifdef IPV6
460 else if (addr->ss.ss_family == AF_INET6)
461 {
462 const struct sockaddr_in6 *v6 = (const struct sockaddr_in6 *)addr;
463 cp = (const unsigned char *)&v6->sin6_addr.s6_addr;
464
465 sprintf(ipbuf, "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x."
466 "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.ip6.arpa.",
467 (unsigned int)(cp[15]&0xf), (unsigned int)(cp[15]>>4),
468 (unsigned int)(cp[14]&0xf), (unsigned int)(cp[14]>>4),
469 (unsigned int)(cp[13]&0xf), (unsigned int)(cp[13]>>4),
470 (unsigned int)(cp[12]&0xf), (unsigned int)(cp[12]>>4),
471 (unsigned int)(cp[11]&0xf), (unsigned int)(cp[11]>>4),
472 (unsigned int)(cp[10]&0xf), (unsigned int)(cp[10]>>4),
473 (unsigned int)(cp[9]&0xf), (unsigned int)(cp[9]>>4),
474 (unsigned int)(cp[8]&0xf), (unsigned int)(cp[8]>>4),
475 (unsigned int)(cp[7]&0xf), (unsigned int)(cp[7]>>4),
476 (unsigned int)(cp[6]&0xf), (unsigned int)(cp[6]>>4),
477 (unsigned int)(cp[5]&0xf), (unsigned int)(cp[5]>>4),
478 (unsigned int)(cp[4]&0xf), (unsigned int)(cp[4]>>4),
479 (unsigned int)(cp[3]&0xf), (unsigned int)(cp[3]>>4),
480 (unsigned int)(cp[2]&0xf), (unsigned int)(cp[2]>>4),
481 (unsigned int)(cp[1]&0xf), (unsigned int)(cp[1]>>4),
482 (unsigned int)(cp[0]&0xf), (unsigned int)(cp[0]>>4));
483 }
484 #endif
485 if (request == NULL)
486 {
487 request = make_request(callback, ctx);
488 request->type = T_PTR;
489 memcpy(&request->addr, addr, sizeof(struct irc_ssaddr));
490 request->name = MyMalloc(HOSTLEN + 1);
491 }
492
493 query_name(ipbuf, C_IN, T_PTR, request);
494 }
495
496 /*
497 * query_name - generate a query based on class, type and name.
498 */
499 static void
500 query_name(const char *name, int query_class, int type,
501 struct reslist *request)
502 {
503 char buf[MAXPACKET];
504 int request_len = 0;
505
506 memset(buf, 0, sizeof(buf));
507
508 if ((request_len = irc_res_mkquery(name, query_class, type,
509 (unsigned char *)buf, sizeof(buf))) > 0)
510 {
511 HEADER *header = (HEADER *)buf;
512
513 /*
514 * generate an unique id
515 * NOTE: we don't have to worry about converting this to and from
516 * network byte order, the nameserver does not interpret this value
517 * and returns it unchanged
518 */
519 do
520 header->id = (header->id + genrand_int32()) & 0xffff;
521 while (find_id(header->id));
522
523 request->id = header->id;
524 ++request->sends;
525
526 request->sent += send_res_msg(buf, request_len, request->sends);
527 }
528 }
529
530 static void
531 resend_query(struct reslist *request)
532 {
533 if (request->resend == 0)
534 return;
535
536 switch (request->type)
537 {
538 case T_PTR:
539 do_query_number(NULL, NULL, &request->addr, request);
540 break;
541 case T_A:
542 do_query_name(NULL, NULL, request->name, request, request->type);
543 break;
544 #ifdef IPV6
545 case T_AAAA:
546 /* didnt work, try A */
547 if (request->state == REQ_AAAA)
548 do_query_name(NULL, NULL, request->name, request, T_A);
549 #endif
550 default:
551 break;
552 }
553 }
554
555 /*
556 * proc_answer - process name server reply
557 */
558 static int
559 proc_answer(struct reslist *request, HEADER* header, char* buf, char* eob)
560 {
561 char hostbuf[HOSTLEN + 100]; /* working buffer */
562 unsigned char *current; /* current position in buf */
563 int query_class; /* answer class */
564 int type; /* answer type */
565 int n; /* temp count */
566 int rd_length;
567 struct sockaddr_in *v4; /* conversion */
568 #ifdef IPV6
569 struct sockaddr_in6 *v6;
570 #endif
571 current = (unsigned char *)buf + sizeof(HEADER);
572
573 for (; header->qdcount > 0; --header->qdcount)
574 {
575 if ((n = irc_dn_skipname(current, (unsigned char *)eob)) < 0)
576 break;
577
578 current += (size_t) n + QFIXEDSZ;
579 }
580
581 /*
582 * process each answer sent to us blech.
583 */
584 while (header->ancount > 0 && (char *)current < eob)
585 {
586 header->ancount--;
587
588 n = irc_dn_expand((unsigned char *)buf, (unsigned char *)eob, current,
589 hostbuf, sizeof(hostbuf));
590
591 if (n < 0)
592 {
593 /*
594 * broken message
595 */
596 return(0);
597 }
598 else if (n == 0)
599 {
600 /*
601 * no more answers left
602 */
603 return(0);
604 }
605
606 hostbuf[HOSTLEN] = '\0';
607
608 /* With Address arithmetic you have to be very anal
609 * this code was not working on alpha due to that
610 * (spotted by rodder/jailbird/dianora)
611 */
612 current += (size_t) n;
613
614 if (!(((char *)current + ANSWER_FIXED_SIZE) < eob))
615 break;
616
617 type = irc_ns_get16(current);
618 current += TYPE_SIZE;
619
620 query_class = irc_ns_get16(current);
621 current += CLASS_SIZE;
622
623 request->ttl = irc_ns_get32(current);
624 current += TTL_SIZE;
625
626 rd_length = irc_ns_get16(current);
627 current += RDLENGTH_SIZE;
628
629 /*
630 * Wait to set request->type until we verify this structure
631 */
632 switch (type)
633 {
634 case T_A:
635 if (request->type != T_A)
636 return(0);
637
638 /*
639 * check for invalid rd_length or too many addresses
640 */
641 if (rd_length != sizeof(struct in_addr))
642 return(0);
643 v4 = (struct sockaddr_in *)&request->addr;
644 request->addr.ss_len = sizeof(struct sockaddr_in);
645 v4->sin_family = AF_INET;
646 memcpy(&v4->sin_addr, current, sizeof(struct in_addr));
647 return(1);
648 break;
649 #ifdef IPV6
650 case T_AAAA:
651 if (request->type != T_AAAA)
652 return(0);
653 if (rd_length != sizeof(struct in6_addr))
654 return(0);
655 request->addr.ss_len = sizeof(struct sockaddr_in6);
656 v6 = (struct sockaddr_in6 *)&request->addr;
657 v6->sin6_family = AF_INET6;
658 memcpy(&v6->sin6_addr, current, sizeof(struct in6_addr));
659 return(1);
660 break;
661 #endif
662 case T_PTR:
663 if (request->type != T_PTR)
664 return(0);
665 n = irc_dn_expand((unsigned char *)buf, (unsigned char *)eob,
666 current, hostbuf, sizeof(hostbuf));
667 if (n < 0)
668 return(0); /* broken message */
669 else if (n == 0)
670 return(0); /* no more answers left */
671
672 strlcpy(request->name, hostbuf, HOSTLEN + 1);
673
674 return(1);
675 break;
676 case T_CNAME: /* first check we already havent started looking
677 into a cname */
678 if (request->type != T_PTR)
679 return(0);
680
681 if (request->state == REQ_CNAME)
682 {
683 n = irc_dn_expand((unsigned char *)buf, (unsigned char *)eob,
684 current, hostbuf, sizeof(hostbuf));
685
686 if (n < 0)
687 return(0);
688 return(1);
689 }
690
691 request->state = REQ_CNAME;
692 current += rd_length;
693 break;
694
695 default:
696 /* XXX I'd rather just throw away the entire bogus thing
697 * but its possible its just a broken nameserver with still
698 * valid answers. But lets do some rudimentary logging for now...
699 */
700 ilog(L_ERROR, "irc_res.c bogus type %d", type);
701 break;
702 }
703 }
704
705 return(1);
706 }
707
708 /*
709 * res_readreply - read a dns reply from the nameserver and process it.
710 */
711 static void
712 res_readreply(fde_t *fd, void *data)
713 {
714 char buf[sizeof(HEADER) + MAXPACKET]
715 /* Sparc and alpha need 16bit-alignment for accessing header->id
716 * (which is uint16_t). Because of the header = (HEADER*) buf;
717 * lateron, this is neeeded. --FaUl
718 */
719 #if defined(__sparc__) || defined(__alpha__)
720 __attribute__((aligned (16)))
721 #endif
722 ;
723 HEADER *header;
724 struct reslist *request = NULL;
725 int rc;
726 socklen_t len = sizeof(struct irc_ssaddr);
727 struct irc_ssaddr lsin;
728
729 rc = recvfrom(fd->fd, buf, sizeof(buf), 0, (struct sockaddr *)&lsin, &len);
730
731 /* Re-schedule a read *after* recvfrom, or we'll be registering
732 * interest where it'll instantly be ready for read :-) -- adrian
733 */
734 comm_setselect(fd, COMM_SELECT_READ, res_readreply, NULL, 0);
735
736 /* Better to cast the sizeof instead of rc */
737 if (rc <= (int)(sizeof(HEADER)))
738 return;
739
740 /*
741 * convert DNS reply reader from Network byte order to CPU byte order.
742 */
743 header = (HEADER *)buf;
744 header->ancount = ntohs(header->ancount);
745 header->qdcount = ntohs(header->qdcount);
746 header->nscount = ntohs(header->nscount);
747 header->arcount = ntohs(header->arcount);
748
749 /*
750 * check against possibly fake replies
751 */
752 if (!res_ourserver(&lsin))
753 return;
754
755 /*
756 * response for an id which we have already received an answer for
757 * just ignore this response.
758 */
759 if (!(request = find_id(header->id)))
760 return;
761
762 if ((header->rcode != NO_ERRORS) || (header->ancount == 0))
763 {
764 if (header->rcode == SERVFAIL || header->rcode == NXDOMAIN)
765 {
766 /*
767 * If a bad error was returned, stop here and don't
768 * send any more (no retries granted).
769 */
770 (*request->callback)(request->callback_ctx, NULL, NULL);
771 rem_request(request);
772 }
773 #ifdef IPV6
774 else
775 {
776 /*
777 * If we havent already tried this, and we're looking up AAAA, try A
778 * now
779 */
780 if (request->state == REQ_AAAA && request->type == T_AAAA)
781 {
782 request->timeout += 4;
783 resend_query(request);
784 }
785 }
786 #endif
787
788 return;
789 }
790
791 /*
792 * If this fails there was an error decoding the received packet,
793 * try it again and hope it works the next time.
794 */
795 if (proc_answer(request, header, buf, buf + rc))
796 {
797 if (request->type == T_PTR)
798 {
799 if (request->name == NULL)
800 {
801 /*
802 * got a PTR response with no name, something bogus is happening
803 * don't bother trying again, the client address doesn't resolve
804 */
805 (*request->callback)(request->callback_ctx, NULL, NULL);
806 rem_request(request);
807 return;
808 }
809
810 /*
811 * Lookup the 'authoritative' name that we were given for the
812 * ip#.
813 *
814 */
815 #ifdef IPV6
816 if (request->addr.ss.ss_family == AF_INET6)
817 gethost_byname_type(request->callback, request->callback_ctx, request->name, T_AAAA);
818 else
819 #endif
820 gethost_byname_type(request->callback, request->callback_ctx, request->name, T_A);
821 rem_request(request);
822 }
823 else
824 {
825 /*
826 * got a name and address response, client resolved
827 */
828 (*request->callback)(request->callback_ctx, &request->addr, request->name);
829 rem_request(request);
830 }
831 }
832 else if (!request->sent)
833 {
834 /* XXX - we got a response for a query we didn't send with a valid id?
835 * this should never happen, bail here and leave the client unresolved
836 */
837 assert(0);
838
839 /* XXX don't leak it */
840 rem_request(request);
841 }
842 }
843
844 void
845 report_dns_servers(struct Client *source_p)
846 {
847 int i;
848 char ipaddr[HOSTIPLEN + 1];
849
850 for (i = 0; i < irc_nscount; i++)
851 {
852 irc_getnameinfo((struct sockaddr *)&(irc_nsaddr_list[i]),
853 irc_nsaddr_list[i].ss_len, ipaddr,
854 sizeof(ipaddr), NULL, 0, NI_NUMERICHOST);
855 sendto_one(source_p, form_str(RPL_STATSALINE),
856 me.name, source_p->name, ipaddr);
857 }
858 }

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svn:eol-style native
svn:keywords Id Revision

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