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1 /*
2  * Copyright (C) 2004-2011  Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (C) 2000-2002  Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and/or distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15  * PERFORMANCE OF THIS SOFTWARE.
16  */
17
18 /* $Id: request.c,v 1.87.148.2 2011-03-12 04:59:17 tbox Exp $ */
19
20 /*! \file */
21
22 #include <config.h>
23
24 #include <isc/magic.h>
25 #include <isc/mem.h>
26 #include <isc/task.h>
27 #include <isc/timer.h>
28 #include <isc/util.h>
29
30 #include <dns/acl.h>
31 #include <dns/compress.h>
32 #include <dns/dispatch.h>
33 #include <dns/events.h>
34 #include <dns/log.h>
35 #include <dns/message.h>
36 #include <dns/rdata.h>
37 #include <dns/rdatastruct.h>
38 #include <dns/request.h>
39 #include <dns/result.h>
40 #include <dns/tsig.h>
41
42 #define REQUESTMGR_MAGIC        ISC_MAGIC('R', 'q', 'u', 'M')
43 #define VALID_REQUESTMGR(mgr)   ISC_MAGIC_VALID(mgr, REQUESTMGR_MAGIC)
44
45 #define REQUEST_MAGIC           ISC_MAGIC('R', 'q', 'u', '!')
46 #define VALID_REQUEST(request)  ISC_MAGIC_VALID(request, REQUEST_MAGIC)
47
48 typedef ISC_LIST(dns_request_t) dns_requestlist_t;
49
50 #define DNS_REQUEST_NLOCKS 7
51
52 struct dns_requestmgr {
53         unsigned int                    magic;
54         isc_mutex_t                     lock;
55         isc_mem_t                      *mctx;
56
57         /* locked */
58         isc_int32_t                     eref;
59         isc_int32_t                     iref;
60         isc_timermgr_t                 *timermgr;
61         isc_socketmgr_t                *socketmgr;
62         isc_taskmgr_t                  *taskmgr;
63         dns_dispatchmgr_t              *dispatchmgr;
64         dns_dispatch_t                 *dispatchv4;
65         dns_dispatch_t                 *dispatchv6;
66         isc_boolean_t                   exiting;
67         isc_eventlist_t                 whenshutdown;
68         unsigned int                    hash;
69         isc_mutex_t                     locks[DNS_REQUEST_NLOCKS];
70         dns_requestlist_t               requests;
71 };
72
73 struct dns_request {
74         unsigned int                    magic;
75         unsigned int                    hash;
76         isc_mem_t                      *mctx;
77         isc_int32_t                     flags;
78         ISC_LINK(dns_request_t)         link;
79         isc_buffer_t                   *query;
80         isc_buffer_t                   *answer;
81         dns_requestevent_t             *event;
82         dns_dispatch_t                 *dispatch;
83         dns_dispentry_t                *dispentry;
84         isc_timer_t                    *timer;
85         dns_requestmgr_t               *requestmgr;
86         isc_buffer_t                   *tsig;
87         dns_tsigkey_t                  *tsigkey;
88         isc_event_t                     ctlevent;
89         isc_boolean_t                   canceling; /* ctlevent outstanding */
90         isc_sockaddr_t                  destaddr;
91         unsigned int                    udpcount;
92 };
93
94 #define DNS_REQUEST_F_CONNECTING 0x0001
95 #define DNS_REQUEST_F_SENDING 0x0002
96 #define DNS_REQUEST_F_CANCELED 0x0004   /*%< ctlevent received, or otherwise
97                                            synchronously canceled */
98 #define DNS_REQUEST_F_TIMEDOUT 0x0008   /*%< canceled due to a timeout */
99 #define DNS_REQUEST_F_TCP 0x0010        /*%< This request used TCP */
100 #define DNS_REQUEST_CANCELED(r) \
101         (((r)->flags & DNS_REQUEST_F_CANCELED) != 0)
102 #define DNS_REQUEST_CONNECTING(r) \
103         (((r)->flags & DNS_REQUEST_F_CONNECTING) != 0)
104 #define DNS_REQUEST_SENDING(r) \
105         (((r)->flags & DNS_REQUEST_F_SENDING) != 0)
106 #define DNS_REQUEST_TIMEDOUT(r) \
107         (((r)->flags & DNS_REQUEST_F_TIMEDOUT) != 0)
108
109
110 /***
111  *** Forward
112  ***/
113
114 static void mgr_destroy(dns_requestmgr_t *requestmgr);
115 static void mgr_shutdown(dns_requestmgr_t *requestmgr);
116 static unsigned int mgr_gethash(dns_requestmgr_t *requestmgr);
117 static void send_shutdown_events(dns_requestmgr_t *requestmgr);
118
119 static isc_result_t req_render(dns_message_t *message, isc_buffer_t **buffer,
120                                unsigned int options, isc_mem_t *mctx);
121 static void req_senddone(isc_task_t *task, isc_event_t *event);
122 static void req_response(isc_task_t *task, isc_event_t *event);
123 static void req_timeout(isc_task_t *task, isc_event_t *event);
124 static isc_socket_t * req_getsocket(dns_request_t *request);
125 static void req_connected(isc_task_t *task, isc_event_t *event);
126 static void req_sendevent(dns_request_t *request, isc_result_t result);
127 static void req_cancel(dns_request_t *request);
128 static void req_destroy(dns_request_t *request);
129 static void req_log(int level, const char *fmt, ...) ISC_FORMAT_PRINTF(2, 3);
130 static void do_cancel(isc_task_t *task, isc_event_t *event);
131
132 /***
133  *** Public
134  ***/
135
136 isc_result_t
137 dns_requestmgr_create(isc_mem_t *mctx,
138                       isc_timermgr_t *timermgr,
139                       isc_socketmgr_t *socketmgr,
140                       isc_taskmgr_t *taskmgr,
141                       dns_dispatchmgr_t *dispatchmgr,
142                       dns_dispatch_t *dispatchv4,
143                       dns_dispatch_t *dispatchv6,
144                       dns_requestmgr_t **requestmgrp)
145 {
146         dns_requestmgr_t *requestmgr;
147         isc_socket_t *socket;
148         isc_result_t result;
149         int i;
150         unsigned int dispattr;
151
152         req_log(ISC_LOG_DEBUG(3), "dns_requestmgr_create");
153
154         REQUIRE(requestmgrp != NULL && *requestmgrp == NULL);
155         REQUIRE(timermgr != NULL);
156         REQUIRE(socketmgr != NULL);
157         REQUIRE(taskmgr != NULL);
158         REQUIRE(dispatchmgr != NULL);
159         UNUSED(socket);
160         if (dispatchv4 != NULL) {
161                 dispattr = dns_dispatch_getattributes(dispatchv4);
162                 REQUIRE((dispattr & DNS_DISPATCHATTR_UDP) != 0);
163         }
164         if (dispatchv6 != NULL) {
165                 dispattr = dns_dispatch_getattributes(dispatchv6);
166                 REQUIRE((dispattr & DNS_DISPATCHATTR_UDP) != 0);
167         }
168
169         requestmgr = isc_mem_get(mctx, sizeof(*requestmgr));
170         if (requestmgr == NULL)
171                 return (ISC_R_NOMEMORY);
172
173         result = isc_mutex_init(&requestmgr->lock);
174         if (result != ISC_R_SUCCESS) {
175                 isc_mem_put(mctx, requestmgr, sizeof(*requestmgr));
176                 return (result);
177         }
178         for (i = 0; i < DNS_REQUEST_NLOCKS; i++) {
179                 result = isc_mutex_init(&requestmgr->locks[i]);
180                 if (result != ISC_R_SUCCESS) {
181                         while (--i >= 0)
182                                 DESTROYLOCK(&requestmgr->locks[i]);
183                         DESTROYLOCK(&requestmgr->lock);
184                         isc_mem_put(mctx, requestmgr, sizeof(*requestmgr));
185                         return (result);
186                 }
187         }
188         requestmgr->timermgr = timermgr;
189         requestmgr->socketmgr = socketmgr;
190         requestmgr->taskmgr = taskmgr;
191         requestmgr->dispatchmgr = dispatchmgr;
192         requestmgr->dispatchv4 = NULL;
193         if (dispatchv4 != NULL)
194                 dns_dispatch_attach(dispatchv4, &requestmgr->dispatchv4);
195         requestmgr->dispatchv6 = NULL;
196         if (dispatchv6 != NULL)
197                 dns_dispatch_attach(dispatchv6, &requestmgr->dispatchv6);
198         requestmgr->mctx = NULL;
199         isc_mem_attach(mctx, &requestmgr->mctx);
200         requestmgr->eref = 1;   /* implicit attach */
201         requestmgr->iref = 0;
202         ISC_LIST_INIT(requestmgr->whenshutdown);
203         ISC_LIST_INIT(requestmgr->requests);
204         requestmgr->exiting = ISC_FALSE;
205         requestmgr->hash = 0;
206         requestmgr->magic = REQUESTMGR_MAGIC;
207
208         req_log(ISC_LOG_DEBUG(3), "dns_requestmgr_create: %p", requestmgr);
209
210         *requestmgrp = requestmgr;
211         return (ISC_R_SUCCESS);
212 }
213
214 void
215 dns_requestmgr_whenshutdown(dns_requestmgr_t *requestmgr, isc_task_t *task,
216                             isc_event_t **eventp)
217 {
218         isc_task_t *clone;
219         isc_event_t *event;
220
221         req_log(ISC_LOG_DEBUG(3), "dns_requestmgr_whenshutdown");
222
223         REQUIRE(VALID_REQUESTMGR(requestmgr));
224         REQUIRE(eventp != NULL);
225
226         event = *eventp;
227         *eventp = NULL;
228
229         LOCK(&requestmgr->lock);
230
231         if (requestmgr->exiting) {
232                 /*
233                  * We're already shutdown.  Send the event.
234                  */
235                 event->ev_sender = requestmgr;
236                 isc_task_send(task, &event);
237         } else {
238                 clone = NULL;
239                 isc_task_attach(task, &clone);
240                 event->ev_sender = clone;
241                 ISC_LIST_APPEND(requestmgr->whenshutdown, event, ev_link);
242         }
243         UNLOCK(&requestmgr->lock);
244 }
245
246 void
247 dns_requestmgr_shutdown(dns_requestmgr_t *requestmgr) {
248
249         REQUIRE(VALID_REQUESTMGR(requestmgr));
250
251         req_log(ISC_LOG_DEBUG(3), "dns_requestmgr_shutdown: %p", requestmgr);
252
253         LOCK(&requestmgr->lock);
254         mgr_shutdown(requestmgr);
255         UNLOCK(&requestmgr->lock);
256 }
257
258 static void
259 mgr_shutdown(dns_requestmgr_t *requestmgr) {
260         dns_request_t *request;
261
262         /*
263          * Caller holds lock.
264          */
265         if (!requestmgr->exiting) {
266                 requestmgr->exiting = ISC_TRUE;
267                 for (request = ISC_LIST_HEAD(requestmgr->requests);
268                      request != NULL;
269                      request = ISC_LIST_NEXT(request, link)) {
270                         dns_request_cancel(request);
271                 }
272                 if (requestmgr->iref == 0) {
273                         INSIST(ISC_LIST_EMPTY(requestmgr->requests));
274                         send_shutdown_events(requestmgr);
275                 }
276         }
277 }
278
279 static void
280 requestmgr_attach(dns_requestmgr_t *source, dns_requestmgr_t **targetp) {
281
282         /*
283          * Locked by caller.
284          */
285
286         REQUIRE(VALID_REQUESTMGR(source));
287         REQUIRE(targetp != NULL && *targetp == NULL);
288
289         REQUIRE(!source->exiting);
290
291         source->iref++;
292         *targetp = source;
293
294         req_log(ISC_LOG_DEBUG(3), "requestmgr_attach: %p: eref %d iref %d",
295                 source, source->eref, source->iref);
296 }
297
298 static void
299 requestmgr_detach(dns_requestmgr_t **requestmgrp) {
300         dns_requestmgr_t *requestmgr;
301         isc_boolean_t need_destroy = ISC_FALSE;
302
303         REQUIRE(requestmgrp != NULL);
304         requestmgr = *requestmgrp;
305         REQUIRE(VALID_REQUESTMGR(requestmgr));
306
307         *requestmgrp = NULL;
308         LOCK(&requestmgr->lock);
309         INSIST(requestmgr->iref > 0);
310         requestmgr->iref--;
311
312         req_log(ISC_LOG_DEBUG(3), "requestmgr_detach: %p: eref %d iref %d",
313                 requestmgr, requestmgr->eref, requestmgr->iref);
314
315         if (requestmgr->iref == 0 && requestmgr->exiting) {
316                 INSIST(ISC_LIST_HEAD(requestmgr->requests) == NULL);
317                 send_shutdown_events(requestmgr);
318                 if (requestmgr->eref == 0)
319                         need_destroy = ISC_TRUE;
320         }
321         UNLOCK(&requestmgr->lock);
322
323         if (need_destroy)
324                 mgr_destroy(requestmgr);
325 }
326
327 void
328 dns_requestmgr_attach(dns_requestmgr_t *source, dns_requestmgr_t **targetp) {
329
330         REQUIRE(VALID_REQUESTMGR(source));
331         REQUIRE(targetp != NULL && *targetp == NULL);
332         REQUIRE(!source->exiting);
333
334         LOCK(&source->lock);
335         source->eref++;
336         *targetp = source;
337         UNLOCK(&source->lock);
338
339         req_log(ISC_LOG_DEBUG(3), "dns_requestmgr_attach: %p: eref %d iref %d",
340                 source, source->eref, source->iref);
341 }
342
343 void
344 dns_requestmgr_detach(dns_requestmgr_t **requestmgrp) {
345         dns_requestmgr_t *requestmgr;
346         isc_boolean_t need_destroy = ISC_FALSE;
347
348         REQUIRE(requestmgrp != NULL);
349         requestmgr = *requestmgrp;
350         REQUIRE(VALID_REQUESTMGR(requestmgr));
351
352         LOCK(&requestmgr->lock);
353         INSIST(requestmgr->eref > 0);
354         requestmgr->eref--;
355
356         req_log(ISC_LOG_DEBUG(3), "dns_requestmgr_detach: %p: eref %d iref %d",
357                 requestmgr, requestmgr->eref, requestmgr->iref);
358
359         if (requestmgr->eref == 0 && requestmgr->iref == 0) {
360                 INSIST(requestmgr->exiting &&
361                        ISC_LIST_HEAD(requestmgr->requests) == NULL);
362                 need_destroy = ISC_TRUE;
363         }
364         UNLOCK(&requestmgr->lock);
365
366         if (need_destroy)
367                 mgr_destroy(requestmgr);
368
369         *requestmgrp = NULL;
370 }
371
372 static void
373 send_shutdown_events(dns_requestmgr_t *requestmgr) {
374         isc_event_t *event, *next_event;
375         isc_task_t *etask;
376
377         req_log(ISC_LOG_DEBUG(3), "send_shutdown_events: %p", requestmgr);
378
379         /*
380          * Caller must be holding the manager lock.
381          */
382         for (event = ISC_LIST_HEAD(requestmgr->whenshutdown);
383              event != NULL;
384              event = next_event) {
385                 next_event = ISC_LIST_NEXT(event, ev_link);
386                 ISC_LIST_UNLINK(requestmgr->whenshutdown, event, ev_link);
387                 etask = event->ev_sender;
388                 event->ev_sender = requestmgr;
389                 isc_task_sendanddetach(&etask, &event);
390         }
391 }
392
393 static void
394 mgr_destroy(dns_requestmgr_t *requestmgr) {
395         int i;
396         isc_mem_t *mctx;
397
398         req_log(ISC_LOG_DEBUG(3), "mgr_destroy");
399
400         REQUIRE(requestmgr->eref == 0);
401         REQUIRE(requestmgr->iref == 0);
402
403         DESTROYLOCK(&requestmgr->lock);
404         for (i = 0; i < DNS_REQUEST_NLOCKS; i++)
405                 DESTROYLOCK(&requestmgr->locks[i]);
406         if (requestmgr->dispatchv4 != NULL)
407                 dns_dispatch_detach(&requestmgr->dispatchv4);
408         if (requestmgr->dispatchv6 != NULL)
409                 dns_dispatch_detach(&requestmgr->dispatchv6);
410         requestmgr->magic = 0;
411         mctx = requestmgr->mctx;
412         isc_mem_put(mctx, requestmgr, sizeof(*requestmgr));
413         isc_mem_detach(&mctx);
414 }
415
416 static unsigned int
417 mgr_gethash(dns_requestmgr_t *requestmgr) {
418         req_log(ISC_LOG_DEBUG(3), "mgr_gethash");
419         /*
420          * Locked by caller.
421          */
422         requestmgr->hash++;
423         return (requestmgr->hash % DNS_REQUEST_NLOCKS);
424 }
425
426 static inline isc_result_t
427 req_send(dns_request_t *request, isc_task_t *task, isc_sockaddr_t *address) {
428         isc_region_t r;
429         isc_socket_t *socket;
430         isc_result_t result;
431
432         req_log(ISC_LOG_DEBUG(3), "req_send: request %p", request);
433
434         REQUIRE(VALID_REQUEST(request));
435         socket = req_getsocket(request);
436         isc_buffer_usedregion(request->query, &r);
437         /*
438          * We could connect the socket when we are using an exclusive dispatch
439          * as we do in resolver.c, but we prefer implementation simplicity
440          * at this moment.
441          */
442         result = isc_socket_sendto(socket, &r, task, req_senddone,
443                                   request, address, NULL);
444         if (result == ISC_R_SUCCESS)
445                 request->flags |= DNS_REQUEST_F_SENDING;
446         return (result);
447 }
448
449 static isc_result_t
450 new_request(isc_mem_t *mctx, dns_request_t **requestp)
451 {
452         dns_request_t *request;
453
454         request = isc_mem_get(mctx, sizeof(*request));
455         if (request == NULL)
456                 return (ISC_R_NOMEMORY);
457
458         /*
459          * Zero structure.
460          */
461         request->magic = 0;
462         request->mctx = NULL;
463         request->flags = 0;
464         ISC_LINK_INIT(request, link);
465         request->query = NULL;
466         request->answer = NULL;
467         request->event = NULL;
468         request->dispatch = NULL;
469         request->dispentry = NULL;
470         request->timer = NULL;
471         request->requestmgr = NULL;
472         request->tsig = NULL;
473         request->tsigkey = NULL;
474         ISC_EVENT_INIT(&request->ctlevent, sizeof(request->ctlevent), 0, NULL,
475                        DNS_EVENT_REQUESTCONTROL, do_cancel, request, NULL,
476                        NULL, NULL);
477         request->canceling = ISC_FALSE;
478         request->udpcount = 0;
479
480         isc_mem_attach(mctx, &request->mctx);
481
482         request->magic = REQUEST_MAGIC;
483         *requestp = request;
484         return (ISC_R_SUCCESS);
485 }
486
487
488 static isc_boolean_t
489 isblackholed(dns_dispatchmgr_t *dispatchmgr, isc_sockaddr_t *destaddr) {
490         dns_acl_t *blackhole;
491         isc_netaddr_t netaddr;
492         int match;
493         isc_boolean_t drop = ISC_FALSE;
494         char netaddrstr[ISC_NETADDR_FORMATSIZE];
495
496         blackhole = dns_dispatchmgr_getblackhole(dispatchmgr);
497         if (blackhole != NULL) {
498                 isc_netaddr_fromsockaddr(&netaddr, destaddr);
499                 if (dns_acl_match(&netaddr, NULL, blackhole,
500                                   NULL, &match, NULL) == ISC_R_SUCCESS &&
501                     match > 0)
502                         drop = ISC_TRUE;
503         }
504         if (drop) {
505                 isc_netaddr_format(&netaddr, netaddrstr, sizeof(netaddrstr));
506                 req_log(ISC_LOG_DEBUG(10), "blackholed address %s", netaddrstr);
507         }
508         return (drop);
509 }
510
511 static isc_result_t
512 create_tcp_dispatch(dns_requestmgr_t *requestmgr, isc_sockaddr_t *srcaddr,
513                     isc_sockaddr_t *destaddr, dns_dispatch_t **dispatchp)
514 {
515         isc_result_t result;
516         isc_socket_t *socket = NULL;
517         isc_sockaddr_t src;
518         unsigned int attrs;
519         isc_sockaddr_t bind_any;
520
521         result = isc_socket_create(requestmgr->socketmgr,
522                                    isc_sockaddr_pf(destaddr),
523                                    isc_sockettype_tcp, &socket);
524         if (result != ISC_R_SUCCESS)
525                 return (result);
526 #ifndef BROKEN_TCP_BIND_BEFORE_CONNECT
527         if (srcaddr == NULL) {
528                 isc_sockaddr_anyofpf(&bind_any,
529                                      isc_sockaddr_pf(destaddr));
530                 result = isc_socket_bind(socket, &bind_any, 0);
531         } else {
532                 src = *srcaddr;
533                 isc_sockaddr_setport(&src, 0);
534                 result = isc_socket_bind(socket, &src, 0);
535         }
536         if (result != ISC_R_SUCCESS)
537                 goto cleanup;
538 #endif
539         attrs = 0;
540         attrs |= DNS_DISPATCHATTR_TCP;
541         attrs |= DNS_DISPATCHATTR_PRIVATE;
542         if (isc_sockaddr_pf(destaddr) == AF_INET)
543                 attrs |= DNS_DISPATCHATTR_IPV4;
544         else
545                 attrs |= DNS_DISPATCHATTR_IPV6;
546         attrs |= DNS_DISPATCHATTR_MAKEQUERY;
547         result = dns_dispatch_createtcp(requestmgr->dispatchmgr,
548                                         socket, requestmgr->taskmgr,
549                                         4096, 2, 1, 1, 3, attrs,
550                                         dispatchp);
551 cleanup:
552         isc_socket_detach(&socket);
553         return (result);
554 }
555
556 static isc_result_t
557 find_udp_dispatch(dns_requestmgr_t *requestmgr, isc_sockaddr_t *srcaddr,
558                   isc_sockaddr_t *destaddr, dns_dispatch_t **dispatchp)
559 {
560         dns_dispatch_t *disp = NULL;
561         unsigned int attrs, attrmask;
562
563         if (srcaddr == NULL) {
564                 switch (isc_sockaddr_pf(destaddr)) {
565                 case PF_INET:
566                         disp = requestmgr->dispatchv4;
567                         break;
568
569                 case PF_INET6:
570                         disp = requestmgr->dispatchv6;
571                         break;
572
573                 default:
574                         return (ISC_R_NOTIMPLEMENTED);
575                 }
576                 if (disp == NULL)
577                         return (ISC_R_FAMILYNOSUPPORT);
578                 dns_dispatch_attach(disp, dispatchp);
579                 return (ISC_R_SUCCESS);
580         }
581         attrs = 0;
582         attrs |= DNS_DISPATCHATTR_UDP;
583         switch (isc_sockaddr_pf(srcaddr)) {
584         case PF_INET:
585                 attrs |= DNS_DISPATCHATTR_IPV4;
586                 break;
587
588         case PF_INET6:
589                 attrs |= DNS_DISPATCHATTR_IPV6;
590                 break;
591
592         default:
593                 return (ISC_R_NOTIMPLEMENTED);
594         }
595         attrmask = 0;
596         attrmask |= DNS_DISPATCHATTR_UDP;
597         attrmask |= DNS_DISPATCHATTR_TCP;
598         attrmask |= DNS_DISPATCHATTR_IPV4;
599         attrmask |= DNS_DISPATCHATTR_IPV6;
600         return (dns_dispatch_getudp(requestmgr->dispatchmgr,
601                                     requestmgr->socketmgr,
602                                     requestmgr->taskmgr,
603                                     srcaddr, 4096,
604                                     1000, 32768, 16411, 16433,
605                                     attrs, attrmask,
606                                     dispatchp));
607 }
608
609 static isc_result_t
610 get_dispatch(isc_boolean_t tcp, dns_requestmgr_t *requestmgr,
611              isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
612              dns_dispatch_t **dispatchp)
613 {
614         isc_result_t result;
615         if (tcp)
616                 result = create_tcp_dispatch(requestmgr, srcaddr,
617                                              destaddr, dispatchp);
618         else
619                 result = find_udp_dispatch(requestmgr, srcaddr,
620                                            destaddr, dispatchp);
621         return (result);
622 }
623
624 static isc_result_t
625 set_timer(isc_timer_t *timer, unsigned int timeout, unsigned int udpresend) {
626         isc_time_t expires;
627         isc_interval_t interval;
628         isc_result_t result;
629         isc_timertype_t timertype;
630
631         isc_interval_set(&interval, timeout, 0);
632         result = isc_time_nowplusinterval(&expires, &interval);
633         isc_interval_set(&interval, udpresend, 0);
634
635         timertype = udpresend != 0 ? isc_timertype_limited : isc_timertype_once;
636         if (result == ISC_R_SUCCESS)
637                 result = isc_timer_reset(timer, timertype, &expires,
638                                          &interval, ISC_FALSE);
639         return (result);
640 }
641
642 isc_result_t
643 dns_request_createraw(dns_requestmgr_t *requestmgr, isc_buffer_t *msgbuf,
644                       isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
645                       unsigned int options, unsigned int timeout,
646                       isc_task_t *task, isc_taskaction_t action, void *arg,
647                       dns_request_t **requestp)
648 {
649         return(dns_request_createraw3(requestmgr, msgbuf, srcaddr, destaddr,
650                                       options, timeout, 0, 0, task, action,
651                                       arg, requestp));
652 }
653
654 isc_result_t
655 dns_request_createraw2(dns_requestmgr_t *requestmgr, isc_buffer_t *msgbuf,
656                        isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
657                        unsigned int options, unsigned int timeout,
658                        unsigned int udptimeout, isc_task_t *task,
659                        isc_taskaction_t action, void *arg,
660                        dns_request_t **requestp)
661 {
662         unsigned int udpretries = 0;
663
664         if (udptimeout != 0)
665                 udpretries = timeout / udptimeout;
666
667         return (dns_request_createraw3(requestmgr, msgbuf, srcaddr, destaddr,
668                                        options, timeout, udptimeout,
669                                        udpretries, task, action, arg,
670                                        requestp));
671 }
672
673 isc_result_t
674 dns_request_createraw3(dns_requestmgr_t *requestmgr, isc_buffer_t *msgbuf,
675                        isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
676                        unsigned int options, unsigned int timeout,
677                        unsigned int udptimeout, unsigned int udpretries,
678                        isc_task_t *task, isc_taskaction_t action, void *arg,
679                        dns_request_t **requestp)
680 {
681         dns_request_t *request = NULL;
682         isc_task_t *tclone = NULL;
683         isc_socket_t *socket = NULL;
684         isc_result_t result;
685         isc_mem_t *mctx;
686         dns_messageid_t id;
687         isc_boolean_t tcp = ISC_FALSE;
688         isc_region_t r;
689
690         REQUIRE(VALID_REQUESTMGR(requestmgr));
691         REQUIRE(msgbuf != NULL);
692         REQUIRE(destaddr != NULL);
693         REQUIRE(task != NULL);
694         REQUIRE(action != NULL);
695         REQUIRE(requestp != NULL && *requestp == NULL);
696         REQUIRE(timeout > 0);
697         if (srcaddr != NULL)
698                 REQUIRE(isc_sockaddr_pf(srcaddr) == isc_sockaddr_pf(destaddr));
699
700         mctx = requestmgr->mctx;
701
702         req_log(ISC_LOG_DEBUG(3), "dns_request_createraw");
703
704         if (isblackholed(requestmgr->dispatchmgr, destaddr))
705                 return (DNS_R_BLACKHOLED);
706
707         request = NULL;
708         result = new_request(mctx, &request);
709         if (result != ISC_R_SUCCESS)
710                 return (result);
711
712         if (udptimeout == 0 && udpretries != 0) {
713                 udptimeout = timeout / (udpretries + 1);
714                 if (udptimeout == 0)
715                         udptimeout = 1;
716         }
717         request->udpcount = udpretries;
718
719         /*
720          * Create timer now.  We will set it below once.
721          */
722         result = isc_timer_create(requestmgr->timermgr, isc_timertype_inactive,
723                                   NULL, NULL, task, req_timeout, request,
724                                   &request->timer);
725         if (result != ISC_R_SUCCESS)
726                 goto cleanup;
727
728         request->event = (dns_requestevent_t *)
729                 isc_event_allocate(mctx, task, DNS_EVENT_REQUESTDONE,
730                                    action, arg, sizeof(dns_requestevent_t));
731         if (request->event == NULL) {
732                 result = ISC_R_NOMEMORY;
733                 goto cleanup;
734         }
735         isc_task_attach(task, &tclone);
736         request->event->ev_sender = task;
737         request->event->request = request;
738         request->event->result = ISC_R_FAILURE;
739
740         isc_buffer_usedregion(msgbuf, &r);
741         if (r.length < DNS_MESSAGE_HEADERLEN || r.length > 65535) {
742                 result = DNS_R_FORMERR;
743                 goto cleanup;
744         }
745
746         if ((options & DNS_REQUESTOPT_TCP) != 0 || r.length > 512)
747                 tcp = ISC_TRUE;
748
749         result = get_dispatch(tcp, requestmgr, srcaddr, destaddr,
750                               &request->dispatch);
751         if (result != ISC_R_SUCCESS)
752                 goto cleanup;
753
754         result = dns_dispatch_addresponse2(request->dispatch, destaddr, task,
755                                            req_response, request, &id,
756                                            &request->dispentry,
757                                            requestmgr->socketmgr);
758         if (result != ISC_R_SUCCESS)
759                 goto cleanup;
760
761         socket = req_getsocket(request);
762         INSIST(socket != NULL);
763
764         result = isc_buffer_allocate(mctx, &request->query,
765                                      r.length + (tcp ? 2 : 0));
766         if (result != ISC_R_SUCCESS)
767                 goto cleanup;
768         if (tcp)
769                 isc_buffer_putuint16(request->query, (isc_uint16_t)r.length);
770         result = isc_buffer_copyregion(request->query, &r);
771         if (result != ISC_R_SUCCESS)
772                 goto cleanup;
773
774         /* Add message ID. */
775         isc_buffer_usedregion(request->query, &r);
776         if (tcp)
777                 isc_region_consume(&r, 2);
778         r.base[0] = (id>>8) & 0xff;
779         r.base[1] = id & 0xff;
780
781         LOCK(&requestmgr->lock);
782         if (requestmgr->exiting) {
783                 UNLOCK(&requestmgr->lock);
784                 result = ISC_R_SHUTTINGDOWN;
785                 goto cleanup;
786         }
787         requestmgr_attach(requestmgr, &request->requestmgr);
788         request->hash = mgr_gethash(requestmgr);
789         ISC_LIST_APPEND(requestmgr->requests, request, link);
790         UNLOCK(&requestmgr->lock);
791
792         result = set_timer(request->timer, timeout, tcp ? 0 : udptimeout);
793         if (result != ISC_R_SUCCESS)
794                 goto unlink;
795
796         request->destaddr = *destaddr;
797         if (tcp) {
798                 result = isc_socket_connect(socket, destaddr, task,
799                                             req_connected, request);
800                 if (result != ISC_R_SUCCESS)
801                         goto unlink;
802                 request->flags |= DNS_REQUEST_F_CONNECTING|DNS_REQUEST_F_TCP;
803         } else {
804                 result = req_send(request, task, destaddr);
805                 if (result != ISC_R_SUCCESS)
806                         goto unlink;
807         }
808
809         req_log(ISC_LOG_DEBUG(3), "dns_request_createraw: request %p",
810                 request);
811         *requestp = request;
812         return (ISC_R_SUCCESS);
813
814  unlink:
815         LOCK(&requestmgr->lock);
816         ISC_LIST_UNLINK(requestmgr->requests, request, link);
817         UNLOCK(&requestmgr->lock);
818
819  cleanup:
820         if (tclone != NULL)
821                 isc_task_detach(&tclone);
822         req_destroy(request);
823         req_log(ISC_LOG_DEBUG(3), "dns_request_createraw: failed %s",
824                 dns_result_totext(result));
825         return (result);
826 }
827
828 isc_result_t
829 dns_request_create(dns_requestmgr_t *requestmgr, dns_message_t *message,
830                    isc_sockaddr_t *address, unsigned int options,
831                    dns_tsigkey_t *key,
832                    unsigned int timeout, isc_task_t *task,
833                    isc_taskaction_t action, void *arg,
834                    dns_request_t **requestp)
835 {
836         return (dns_request_createvia3(requestmgr, message, NULL, address,
837                                        options, key, timeout, 0, 0, task,
838                                        action, arg, requestp));
839 }
840
841 isc_result_t
842 dns_request_createvia(dns_requestmgr_t *requestmgr, dns_message_t *message,
843                       isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
844                       unsigned int options, dns_tsigkey_t *key,
845                       unsigned int timeout, isc_task_t *task,
846                       isc_taskaction_t action, void *arg,
847                       dns_request_t **requestp)
848 {
849         return(dns_request_createvia3(requestmgr, message, srcaddr, destaddr,
850                                       options, key, timeout, 0, 0, task,
851                                       action, arg, requestp));
852 }
853
854 isc_result_t
855 dns_request_createvia2(dns_requestmgr_t *requestmgr, dns_message_t *message,
856                        isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
857                        unsigned int options, dns_tsigkey_t *key,
858                        unsigned int timeout, unsigned int udptimeout,
859                        isc_task_t *task, isc_taskaction_t action, void *arg,
860                        dns_request_t **requestp)
861 {
862         unsigned int udpretries = 0;
863
864         if (udptimeout != 0)
865                 udpretries = timeout / udptimeout;
866         return (dns_request_createvia3(requestmgr, message, srcaddr, destaddr,
867                                        options, key, timeout, udptimeout,
868                                        udpretries, task, action, arg,
869                                        requestp));
870 }
871
872 isc_result_t
873 dns_request_createvia3(dns_requestmgr_t *requestmgr, dns_message_t *message,
874                        isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
875                        unsigned int options, dns_tsigkey_t *key,
876                        unsigned int timeout, unsigned int udptimeout,
877                        unsigned int udpretries, isc_task_t *task,
878                        isc_taskaction_t action, void *arg,
879                        dns_request_t **requestp)
880 {
881         dns_request_t *request = NULL;
882         isc_task_t *tclone = NULL;
883         isc_socket_t *socket = NULL;
884         isc_result_t result;
885         isc_mem_t *mctx;
886         dns_messageid_t id;
887         isc_boolean_t tcp;
888         isc_boolean_t setkey = ISC_TRUE;
889
890         REQUIRE(VALID_REQUESTMGR(requestmgr));
891         REQUIRE(message != NULL);
892         REQUIRE(destaddr != NULL);
893         REQUIRE(task != NULL);
894         REQUIRE(action != NULL);
895         REQUIRE(requestp != NULL && *requestp == NULL);
896         REQUIRE(timeout > 0);
897         if (srcaddr != NULL)
898                 REQUIRE(isc_sockaddr_pf(srcaddr) == isc_sockaddr_pf(destaddr));
899
900         mctx = requestmgr->mctx;
901
902         req_log(ISC_LOG_DEBUG(3), "dns_request_createvia");
903
904         if (isblackholed(requestmgr->dispatchmgr, destaddr))
905                 return (DNS_R_BLACKHOLED);
906
907         request = NULL;
908         result = new_request(mctx, &request);
909         if (result != ISC_R_SUCCESS)
910                 return (result);
911
912         if (udptimeout == 0 && udpretries != 0) {
913                 udptimeout = timeout / (udpretries + 1);
914                 if (udptimeout == 0)
915                         udptimeout = 1;
916         }
917         request->udpcount = udpretries;
918
919         /*
920          * Create timer now.  We will set it below once.
921          */
922         result = isc_timer_create(requestmgr->timermgr, isc_timertype_inactive,
923                                   NULL, NULL, task, req_timeout, request,
924                                   &request->timer);
925         if (result != ISC_R_SUCCESS)
926                 goto cleanup;
927
928         request->event = (dns_requestevent_t *)
929                 isc_event_allocate(mctx, task, DNS_EVENT_REQUESTDONE,
930                                    action, arg, sizeof(dns_requestevent_t));
931         if (request->event == NULL) {
932                 result = ISC_R_NOMEMORY;
933                 goto cleanup;
934         }
935         isc_task_attach(task, &tclone);
936         request->event->ev_sender = task;
937         request->event->request = request;
938         request->event->result = ISC_R_FAILURE;
939         if (key != NULL)
940                 dns_tsigkey_attach(key, &request->tsigkey);
941
942  use_tcp:
943         tcp = ISC_TF((options & DNS_REQUESTOPT_TCP) != 0);
944         result = get_dispatch(tcp, requestmgr, srcaddr, destaddr,
945                               &request->dispatch);
946         if (result != ISC_R_SUCCESS)
947                 goto cleanup;
948
949         result = dns_dispatch_addresponse2(request->dispatch, destaddr, task,
950                                            req_response, request, &id,
951                                            &request->dispentry,
952                                            requestmgr->socketmgr);
953         if (result != ISC_R_SUCCESS)
954                 goto cleanup;
955         socket = req_getsocket(request);
956         INSIST(socket != NULL);
957
958         message->id = id;
959         if (setkey) {
960                 result = dns_message_settsigkey(message, request->tsigkey);
961                 if (result != ISC_R_SUCCESS)
962                         goto cleanup;
963         }
964         result = req_render(message, &request->query, options, mctx);
965         if (result == DNS_R_USETCP &&
966             (options & DNS_REQUESTOPT_TCP) == 0) {
967                 /*
968                  * Try again using TCP.
969                  */
970                 dns_message_renderreset(message);
971                 dns_dispatch_removeresponse(&request->dispentry, NULL);
972                 dns_dispatch_detach(&request->dispatch);
973                 socket = NULL;
974                 options |= DNS_REQUESTOPT_TCP;
975                 setkey = ISC_FALSE;
976                 goto use_tcp;
977         }
978         if (result != ISC_R_SUCCESS)
979                 goto cleanup;
980
981         result = dns_message_getquerytsig(message, mctx, &request->tsig);
982         if (result != ISC_R_SUCCESS)
983                 goto cleanup;
984
985         LOCK(&requestmgr->lock);
986         if (requestmgr->exiting) {
987                 UNLOCK(&requestmgr->lock);
988                 result = ISC_R_SHUTTINGDOWN;
989                 goto cleanup;
990         }
991         requestmgr_attach(requestmgr, &request->requestmgr);
992         request->hash = mgr_gethash(requestmgr);
993         ISC_LIST_APPEND(requestmgr->requests, request, link);
994         UNLOCK(&requestmgr->lock);
995
996         result = set_timer(request->timer, timeout, tcp ? 0 : udptimeout);
997         if (result != ISC_R_SUCCESS)
998                 goto unlink;
999
1000         request->destaddr = *destaddr;
1001         if (tcp) {
1002                 result = isc_socket_connect(socket, destaddr, task,
1003                                             req_connected, request);
1004                 if (result != ISC_R_SUCCESS)
1005                         goto unlink;
1006                 request->flags |= DNS_REQUEST_F_CONNECTING|DNS_REQUEST_F_TCP;
1007         } else {
1008                 result = req_send(request, task, destaddr);
1009                 if (result != ISC_R_SUCCESS)
1010                         goto unlink;
1011         }
1012
1013         req_log(ISC_LOG_DEBUG(3), "dns_request_createvia: request %p",
1014                 request);
1015         *requestp = request;
1016         return (ISC_R_SUCCESS);
1017
1018  unlink:
1019         LOCK(&requestmgr->lock);
1020         ISC_LIST_UNLINK(requestmgr->requests, request, link);
1021         UNLOCK(&requestmgr->lock);
1022
1023  cleanup:
1024         if (tclone != NULL)
1025                 isc_task_detach(&tclone);
1026         req_destroy(request);
1027         req_log(ISC_LOG_DEBUG(3), "dns_request_createvia: failed %s",
1028                 dns_result_totext(result));
1029         return (result);
1030 }
1031
1032 static isc_result_t
1033 req_render(dns_message_t *message, isc_buffer_t **bufferp,
1034            unsigned int options, isc_mem_t *mctx)
1035 {
1036         isc_buffer_t *buf1 = NULL;
1037         isc_buffer_t *buf2 = NULL;
1038         isc_result_t result;
1039         isc_region_t r;
1040         isc_boolean_t tcp = ISC_FALSE;
1041         dns_compress_t cctx;
1042         isc_boolean_t cleanup_cctx = ISC_FALSE;
1043
1044         REQUIRE(bufferp != NULL && *bufferp == NULL);
1045
1046         req_log(ISC_LOG_DEBUG(3), "request_render");
1047
1048         /*
1049          * Create buffer able to hold largest possible message.
1050          */
1051         result = isc_buffer_allocate(mctx, &buf1, 65535);
1052         if (result != ISC_R_SUCCESS)
1053                 return (result);
1054
1055         result = dns_compress_init(&cctx, -1, mctx);
1056         if (result != ISC_R_SUCCESS)
1057                 return (result);
1058         cleanup_cctx = ISC_TRUE;
1059
1060         if ((options & DNS_REQUESTOPT_CASE) != 0)
1061                 dns_compress_setsensitive(&cctx, ISC_TRUE);
1062
1063         /*
1064          * Render message.
1065          */
1066         result = dns_message_renderbegin(message, &cctx, buf1);
1067         if (result != ISC_R_SUCCESS)
1068                 goto cleanup;
1069         result = dns_message_rendersection(message, DNS_SECTION_QUESTION, 0);
1070         if (result != ISC_R_SUCCESS)
1071                 goto cleanup;
1072         result = dns_message_rendersection(message, DNS_SECTION_ANSWER, 0);
1073         if (result != ISC_R_SUCCESS)
1074                 goto cleanup;
1075         result = dns_message_rendersection(message, DNS_SECTION_AUTHORITY, 0);
1076         if (result != ISC_R_SUCCESS)
1077                 goto cleanup;
1078         result = dns_message_rendersection(message, DNS_SECTION_ADDITIONAL, 0);
1079         if (result != ISC_R_SUCCESS)
1080                 goto cleanup;
1081         result = dns_message_renderend(message);
1082         if (result != ISC_R_SUCCESS)
1083                 goto cleanup;
1084
1085         dns_compress_invalidate(&cctx);
1086         cleanup_cctx = ISC_FALSE;
1087
1088         /*
1089          * Copy rendered message to exact sized buffer.
1090          */
1091         isc_buffer_usedregion(buf1, &r);
1092         if ((options & DNS_REQUESTOPT_TCP) != 0) {
1093                 tcp = ISC_TRUE;
1094         } else if (r.length > 512) {
1095                 result = DNS_R_USETCP;
1096                 goto cleanup;
1097         }
1098         result = isc_buffer_allocate(mctx, &buf2, r.length + (tcp ? 2 : 0));
1099         if (result != ISC_R_SUCCESS)
1100                 goto cleanup;
1101         if (tcp)
1102                 isc_buffer_putuint16(buf2, (isc_uint16_t)r.length);
1103         result = isc_buffer_copyregion(buf2, &r);
1104         if (result != ISC_R_SUCCESS)
1105                 goto cleanup;
1106
1107         /*
1108          * Cleanup and return.
1109          */
1110         isc_buffer_free(&buf1);
1111         *bufferp = buf2;
1112         return (ISC_R_SUCCESS);
1113
1114  cleanup:
1115         dns_message_renderreset(message);
1116         if (buf1 != NULL)
1117                 isc_buffer_free(&buf1);
1118         if (buf2 != NULL)
1119                 isc_buffer_free(&buf2);
1120         if (cleanup_cctx)
1121                 dns_compress_invalidate(&cctx);
1122         return (result);
1123 }
1124
1125
1126 /*
1127  * If this request is no longer waiting for events,
1128  * send the completion event.  This will ultimately
1129  * cause the request to be destroyed.
1130  *
1131  * Requires:
1132  *      'request' is locked by the caller.
1133  */
1134 static void
1135 send_if_done(dns_request_t *request, isc_result_t result) {
1136         if (!DNS_REQUEST_CONNECTING(request) &&
1137             !DNS_REQUEST_SENDING(request) &&
1138             !request->canceling)
1139                 req_sendevent(request, result);
1140 }
1141
1142 /*
1143  * Handle the control event.
1144  */
1145 static void
1146 do_cancel(isc_task_t *task, isc_event_t *event) {
1147         dns_request_t *request = event->ev_arg;
1148         UNUSED(task);
1149         INSIST(event->ev_type == DNS_EVENT_REQUESTCONTROL);
1150         LOCK(&request->requestmgr->locks[request->hash]);
1151         request->canceling = ISC_FALSE;
1152         if (!DNS_REQUEST_CANCELED(request))
1153                 req_cancel(request);
1154         send_if_done(request, ISC_R_CANCELED);
1155         UNLOCK(&request->requestmgr->locks[request->hash]);
1156 }
1157
1158 void
1159 dns_request_cancel(dns_request_t *request) {
1160         REQUIRE(VALID_REQUEST(request));
1161
1162         req_log(ISC_LOG_DEBUG(3), "dns_request_cancel: request %p", request);
1163
1164         REQUIRE(VALID_REQUEST(request));
1165
1166         LOCK(&request->requestmgr->locks[request->hash]);
1167         if (!request->canceling && !DNS_REQUEST_CANCELED(request)) {
1168                 isc_event_t *ev =  &request->ctlevent;
1169                 isc_task_send(request->event->ev_sender, &ev);
1170                 request->canceling = ISC_TRUE;
1171         }
1172         UNLOCK(&request->requestmgr->locks[request->hash]);
1173 }
1174
1175 isc_result_t
1176 dns_request_getresponse(dns_request_t *request, dns_message_t *message,
1177                         unsigned int options)
1178 {
1179         isc_result_t result;
1180
1181         REQUIRE(VALID_REQUEST(request));
1182         REQUIRE(request->answer != NULL);
1183
1184         req_log(ISC_LOG_DEBUG(3), "dns_request_getresponse: request %p",
1185                 request);
1186
1187         result = dns_message_setquerytsig(message, request->tsig);
1188         if (result != ISC_R_SUCCESS)
1189                 return (result);
1190         result = dns_message_settsigkey(message, request->tsigkey);
1191         if (result != ISC_R_SUCCESS)
1192                 return (result);
1193         result = dns_message_parse(message, request->answer, options);
1194         if (result != ISC_R_SUCCESS)
1195                 return (result);
1196         if (request->tsigkey != NULL)
1197                 result = dns_tsig_verify(request->answer, message, NULL, NULL);
1198         return (result);
1199 }
1200
1201 isc_boolean_t
1202 dns_request_usedtcp(dns_request_t *request) {
1203         REQUIRE(VALID_REQUEST(request));
1204
1205         return (ISC_TF((request->flags & DNS_REQUEST_F_TCP) != 0));
1206 }
1207
1208 void
1209 dns_request_destroy(dns_request_t **requestp) {
1210         dns_request_t *request;
1211
1212         REQUIRE(requestp != NULL && VALID_REQUEST(*requestp));
1213
1214         request = *requestp;
1215
1216         req_log(ISC_LOG_DEBUG(3), "dns_request_destroy: request %p", request);
1217
1218         LOCK(&request->requestmgr->lock);
1219         LOCK(&request->requestmgr->locks[request->hash]);
1220         ISC_LIST_UNLINK(request->requestmgr->requests, request, link);
1221         INSIST(!DNS_REQUEST_CONNECTING(request));
1222         INSIST(!DNS_REQUEST_SENDING(request));
1223         UNLOCK(&request->requestmgr->locks[request->hash]);
1224         UNLOCK(&request->requestmgr->lock);
1225
1226         /*
1227          * These should have been cleaned up by req_cancel() before
1228          * the completion event was sent.
1229          */
1230         INSIST(!ISC_LINK_LINKED(request, link));
1231         INSIST(request->dispentry == NULL);
1232         INSIST(request->dispatch == NULL);
1233         INSIST(request->timer == NULL);
1234
1235         req_destroy(request);
1236
1237         *requestp = NULL;
1238 }
1239
1240 /***
1241  *** Private: request.
1242  ***/
1243
1244 static isc_socket_t *
1245 req_getsocket(dns_request_t *request) {
1246         unsigned int dispattr;
1247         isc_socket_t *socket;
1248
1249         dispattr = dns_dispatch_getattributes(request->dispatch);
1250         if ((dispattr & DNS_DISPATCHATTR_EXCLUSIVE) != 0) {
1251                 INSIST(request->dispentry != NULL);
1252                 socket = dns_dispatch_getentrysocket(request->dispentry);
1253         } else
1254                 socket = dns_dispatch_getsocket(request->dispatch);
1255
1256         return (socket);
1257 }
1258
1259 static void
1260 req_connected(isc_task_t *task, isc_event_t *event) {
1261         isc_socketevent_t *sevent = (isc_socketevent_t *)event;
1262         isc_result_t result;
1263         dns_request_t *request = event->ev_arg;
1264
1265         REQUIRE(event->ev_type == ISC_SOCKEVENT_CONNECT);
1266         REQUIRE(VALID_REQUEST(request));
1267         REQUIRE(DNS_REQUEST_CONNECTING(request));
1268
1269         req_log(ISC_LOG_DEBUG(3), "req_connected: request %p", request);
1270
1271         LOCK(&request->requestmgr->locks[request->hash]);
1272         request->flags &= ~DNS_REQUEST_F_CONNECTING;
1273
1274         if (DNS_REQUEST_CANCELED(request)) {
1275                 /*
1276                  * Send delayed event.
1277                  */
1278                 if (DNS_REQUEST_TIMEDOUT(request))
1279                         send_if_done(request, ISC_R_TIMEDOUT);
1280                 else
1281                         send_if_done(request, ISC_R_CANCELED);
1282         } else {
1283                 dns_dispatch_starttcp(request->dispatch);
1284                 result = sevent->result;
1285                 if (result == ISC_R_SUCCESS)
1286                         result = req_send(request, task, NULL);
1287
1288                 if (result != ISC_R_SUCCESS) {
1289                         req_cancel(request);
1290                         send_if_done(request, ISC_R_CANCELED);
1291                 }
1292         }
1293         UNLOCK(&request->requestmgr->locks[request->hash]);
1294         isc_event_free(&event);
1295 }
1296
1297 static void
1298 req_senddone(isc_task_t *task, isc_event_t *event) {
1299         isc_socketevent_t *sevent = (isc_socketevent_t *)event;
1300         dns_request_t *request = event->ev_arg;
1301
1302         REQUIRE(event->ev_type == ISC_SOCKEVENT_SENDDONE);
1303         REQUIRE(VALID_REQUEST(request));
1304         REQUIRE(DNS_REQUEST_SENDING(request));
1305
1306         req_log(ISC_LOG_DEBUG(3), "req_senddone: request %p", request);
1307
1308         UNUSED(task);
1309
1310         LOCK(&request->requestmgr->locks[request->hash]);
1311         request->flags &= ~DNS_REQUEST_F_SENDING;
1312
1313         if (DNS_REQUEST_CANCELED(request)) {
1314                 /*
1315                  * Send delayed event.
1316                  */
1317                 if (DNS_REQUEST_TIMEDOUT(request))
1318                         send_if_done(request, ISC_R_TIMEDOUT);
1319                 else
1320                         send_if_done(request, ISC_R_CANCELED);
1321         } else if (sevent->result != ISC_R_SUCCESS) {
1322                         req_cancel(request);
1323                         send_if_done(request, ISC_R_CANCELED);
1324         }
1325         UNLOCK(&request->requestmgr->locks[request->hash]);
1326
1327         isc_event_free(&event);
1328 }
1329
1330 static void
1331 req_response(isc_task_t *task, isc_event_t *event) {
1332         isc_result_t result;
1333         dns_request_t *request = event->ev_arg;
1334         dns_dispatchevent_t *devent = (dns_dispatchevent_t *)event;
1335         isc_region_t r;
1336
1337         REQUIRE(VALID_REQUEST(request));
1338         REQUIRE(event->ev_type == DNS_EVENT_DISPATCH);
1339
1340         UNUSED(task);
1341
1342         req_log(ISC_LOG_DEBUG(3), "req_response: request %p: %s", request,
1343                 dns_result_totext(devent->result));
1344
1345         LOCK(&request->requestmgr->locks[request->hash]);
1346         result = devent->result;
1347         if (result != ISC_R_SUCCESS)
1348                 goto done;
1349
1350         /*
1351          * Copy buffer to request.
1352          */
1353         isc_buffer_usedregion(&devent->buffer, &r);
1354         result = isc_buffer_allocate(request->mctx, &request->answer,
1355                                      r.length);
1356         if (result != ISC_R_SUCCESS)
1357                 goto done;
1358         result = isc_buffer_copyregion(request->answer, &r);
1359         if (result != ISC_R_SUCCESS)
1360                 isc_buffer_free(&request->answer);
1361  done:
1362         /*
1363          * Cleanup.
1364          */
1365         dns_dispatch_removeresponse(&request->dispentry, &devent);
1366         req_cancel(request);
1367         /*
1368          * Send completion event.
1369          */
1370         send_if_done(request, result);
1371         UNLOCK(&request->requestmgr->locks[request->hash]);
1372 }
1373
1374 static void
1375 req_timeout(isc_task_t *task, isc_event_t *event) {
1376         dns_request_t *request = event->ev_arg;
1377         isc_result_t result;
1378
1379         REQUIRE(VALID_REQUEST(request));
1380
1381         req_log(ISC_LOG_DEBUG(3), "req_timeout: request %p", request);
1382
1383         UNUSED(task);
1384         LOCK(&request->requestmgr->locks[request->hash]);
1385         if (event->ev_type == ISC_TIMEREVENT_TICK &&
1386             request->udpcount-- != 0) {
1387                 if (! DNS_REQUEST_SENDING(request)) {
1388                         result = req_send(request, task, &request->destaddr);
1389                         if (result != ISC_R_SUCCESS) {
1390                                 req_cancel(request);
1391                                 send_if_done(request, result);
1392                         }
1393                 }
1394         } else {
1395                 request->flags |= DNS_REQUEST_F_TIMEDOUT;
1396                 req_cancel(request);
1397                 send_if_done(request, ISC_R_TIMEDOUT);
1398         }
1399         UNLOCK(&request->requestmgr->locks[request->hash]);
1400         isc_event_free(&event);
1401 }
1402
1403 static void
1404 req_sendevent(dns_request_t *request, isc_result_t result) {
1405         isc_task_t *task;
1406
1407         REQUIRE(VALID_REQUEST(request));
1408
1409         req_log(ISC_LOG_DEBUG(3), "req_sendevent: request %p", request);
1410
1411         /*
1412          * Lock held by caller.
1413          */
1414         task = request->event->ev_sender;
1415         request->event->ev_sender = request;
1416         request->event->result = result;
1417         isc_task_sendanddetach(&task, (isc_event_t **)&request->event);
1418 }
1419
1420 static void
1421 req_destroy(dns_request_t *request) {
1422         isc_mem_t *mctx;
1423
1424         REQUIRE(VALID_REQUEST(request));
1425
1426         req_log(ISC_LOG_DEBUG(3), "req_destroy: request %p", request);
1427
1428         request->magic = 0;
1429         if (request->query != NULL)
1430                 isc_buffer_free(&request->query);
1431         if (request->answer != NULL)
1432                 isc_buffer_free(&request->answer);
1433         if (request->event != NULL)
1434                 isc_event_free((isc_event_t **)&request->event);
1435         if (request->dispentry != NULL)
1436                 dns_dispatch_removeresponse(&request->dispentry, NULL);
1437         if (request->dispatch != NULL)
1438                 dns_dispatch_detach(&request->dispatch);
1439         if (request->timer != NULL)
1440                 isc_timer_detach(&request->timer);
1441         if (request->tsig != NULL)
1442                 isc_buffer_free(&request->tsig);
1443         if (request->tsigkey != NULL)
1444                 dns_tsigkey_detach(&request->tsigkey);
1445         if (request->requestmgr != NULL)
1446                 requestmgr_detach(&request->requestmgr);
1447         mctx = request->mctx;
1448         isc_mem_put(mctx, request, sizeof(*request));
1449         isc_mem_detach(&mctx);
1450 }
1451
1452 /*
1453  * Stop the current request.  Must be called from the request's task.
1454  */
1455 static void
1456 req_cancel(dns_request_t *request) {
1457         isc_socket_t *socket;
1458         unsigned int dispattr;
1459
1460         REQUIRE(VALID_REQUEST(request));
1461
1462         req_log(ISC_LOG_DEBUG(3), "req_cancel: request %p", request);
1463
1464         /*
1465          * Lock held by caller.
1466          */
1467         request->flags |= DNS_REQUEST_F_CANCELED;
1468
1469         if (request->timer != NULL)
1470                 isc_timer_detach(&request->timer);
1471         dispattr = dns_dispatch_getattributes(request->dispatch);
1472         socket = NULL;
1473         if (DNS_REQUEST_CONNECTING(request) || DNS_REQUEST_SENDING(request)) {
1474                 if ((dispattr & DNS_DISPATCHATTR_EXCLUSIVE) != 0) {
1475                         if (request->dispentry != NULL) {
1476                                 socket = dns_dispatch_getentrysocket(
1477                                         request->dispentry);
1478                         }
1479                 } else
1480                         socket = dns_dispatch_getsocket(request->dispatch);
1481                 if (DNS_REQUEST_CONNECTING(request) && socket != NULL)
1482                         isc_socket_cancel(socket, NULL, ISC_SOCKCANCEL_CONNECT);
1483                 if (DNS_REQUEST_SENDING(request) && socket != NULL)
1484                         isc_socket_cancel(socket, NULL, ISC_SOCKCANCEL_SEND);
1485         }
1486         if (request->dispentry != NULL)
1487                 dns_dispatch_removeresponse(&request->dispentry, NULL);
1488         dns_dispatch_detach(&request->dispatch);
1489 }
1490
1491 static void
1492 req_log(int level, const char *fmt, ...) {
1493         va_list ap;
1494
1495         va_start(ap, fmt);
1496         isc_log_vwrite(dns_lctx, DNS_LOGCATEGORY_GENERAL,
1497                        DNS_LOGMODULE_REQUEST, level, fmt, ap);
1498         va_end(ap);
1499 }