contrib/bind9/bin/named/client.c

   1 /*
   2  * Copyright (C) 2004-2008  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2003  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: client.c,v 1.219.18.31 2008/05/22 23:46:03 tbox Exp $ */
  19
  20 #include <config.h>
  21
  22 #include <isc/formatcheck.h>
  23 #include <isc/mutex.h>
  24 #include <isc/once.h>
  25 #include <isc/platform.h>
  26 #include <isc/print.h>
  27 #include <isc/stdio.h>
  28 #include <isc/string.h>
  29 #include <isc/task.h>
  30 #include <isc/timer.h>
  31 #include <isc/util.h>
  32
  33 #include <dns/db.h>
  34 #include <dns/dispatch.h>
  35 #include <dns/events.h>
  36 #include <dns/message.h>
  37 #include <dns/peer.h>
  38 #include <dns/rcode.h>
  39 #include <dns/rdata.h>
  40 #include <dns/rdataclass.h>
  41 #include <dns/rdatalist.h>
  42 #include <dns/rdataset.h>
  43 #include <dns/resolver.h>
  44 #include <dns/tsig.h>
  45 #include <dns/view.h>
  46 #include <dns/zone.h>
  47
  48 #include <named/interfacemgr.h>
  49 #include <named/log.h>
  50 #include <named/notify.h>
  51 #include <named/server.h>
  52 #include <named/update.h>
  53
  54 /***
  55  *** Client
  56  ***/
  57
  58 /*! \file
  59  * Client Routines
  60  *
  61  * Important note!
  62  *
  63  * All client state changes, other than that from idle to listening, occur
  64  * as a result of events.  This guarantees serialization and avoids the
  65  * need for locking.
  66  *
  67  * If a routine is ever created that allows someone other than the client's
  68  * task to change the client, then the client will have to be locked.
  69  */
  70
  71 #define NS_CLIENT_TRACE
  72 #ifdef NS_CLIENT_TRACE
  73 #define CTRACE(m)       ns_client_log(client, \
  74                                       NS_LOGCATEGORY_CLIENT, \
  75                                       NS_LOGMODULE_CLIENT, \
  76                                       ISC_LOG_DEBUG(3), \
  77                                       "%s", (m))
  78 #define MTRACE(m)       isc_log_write(ns_g_lctx, \
  79                                       NS_LOGCATEGORY_GENERAL, \
  80                                       NS_LOGMODULE_CLIENT, \
  81                                       ISC_LOG_DEBUG(3), \
  82                                       "clientmgr @%p: %s", manager, (m))
  83 #else
  84 #define CTRACE(m)       ((void)(m))
  85 #define MTRACE(m)       ((void)(m))
  86 #endif
  87
  88 #define TCP_CLIENT(c)   (((c)->attributes & NS_CLIENTATTR_TCP) != 0)
  89
  90 #define TCP_BUFFER_SIZE                 (65535 + 2)
  91 #define SEND_BUFFER_SIZE                4096
  92 #define RECV_BUFFER_SIZE                4096
  93
  94 #ifdef ISC_PLATFORM_USETHREADS
  95 #define NMCTXS                          100
  96 /*%<
  97  * Number of 'mctx pools' for clients. (Should this be configurable?)
  98  * When enabling threads, we use a pool of memory contexts shared by
  99  * client objects, since concurrent access to a shared context would cause
 100  * heavy contentions.  The above constant is expected to be enough for
 101  * completely avoiding contentions among threads for an authoritative-only
 102  * server.
 103  */
 104 #else
 105 #define NMCTXS                          0
 106 /*%<
 107  * If named with built without thread, simply share manager's context.  Using
 108  * a separate context in this case would simply waste memory.
 109  */
 110 #endif
 111
 112 /*% nameserver client manager structure */
 113 struct ns_clientmgr {
 114         /* Unlocked. */
 115         unsigned int                    magic;
 116         isc_mem_t *                     mctx;
 117         isc_taskmgr_t *                 taskmgr;
 118         isc_timermgr_t *                timermgr;
 119         isc_mutex_t                     lock;
 120         /* Locked by lock. */
 121         isc_boolean_t                   exiting;
 122         client_list_t                   active;         /*%< Active clients */
 123         client_list_t                   recursing;      /*%< Recursing clients */
 124         client_list_t                   inactive;       /*%< To be recycled */
 125 #if NMCTXS > 0
 126         /*%< mctx pool for clients. */
 127         unsigned int                    nextmctx;
 128         isc_mem_t *                     mctxpool[NMCTXS];
 129 #endif
 130 };
 131
 132 #define MANAGER_MAGIC                   ISC_MAGIC('N', 'S', 'C', 'm')
 133 #define VALID_MANAGER(m)                ISC_MAGIC_VALID(m, MANAGER_MAGIC)
 134
 135 /*!
 136  * Client object states.  Ordering is significant: higher-numbered
 137  * states are generally "more active", meaning that the client can
 138  * have more dynamically allocated data, outstanding events, etc.
 139  * In the list below, any such properties listed for state N
 140  * also apply to any state > N.
 141  *
 142  * To force the client into a less active state, set client->newstate
 143  * to that state and call exit_check().  This will cause any
 144  * activities defined for higher-numbered states to be aborted.
 145  */
 146
 147 #define NS_CLIENTSTATE_FREED    0
 148 /*%<
 149  * The client object no longer exists.
 150  */
 151
 152 #define NS_CLIENTSTATE_INACTIVE 1
 153 /*%<
 154  * The client object exists and has a task and timer.
 155  * Its "query" struct and sendbuf are initialized.
 156  * It is on the client manager's list of inactive clients.
 157  * It has a message and OPT, both in the reset state.
 158  */
 159
 160 #define NS_CLIENTSTATE_READY    2
 161 /*%<
 162  * The client object is either a TCP or a UDP one, and
 163  * it is associated with a network interface.  It is on the
 164  * client manager's list of active clients.
 165  *
 166  * If it is a TCP client object, it has a TCP listener socket
 167  * and an outstanding TCP listen request.
 168  *
 169  * If it is a UDP client object, it has a UDP listener socket
 170  * and an outstanding UDP receive request.
 171  */
 172
 173 #define NS_CLIENTSTATE_READING  3
 174 /*%<
 175  * The client object is a TCP client object that has received
 176  * a connection.  It has a tcpsocket, tcpmsg, TCP quota, and an
 177  * outstanding TCP read request.  This state is not used for
 178  * UDP client objects.
 179  */
 180
 181 #define NS_CLIENTSTATE_WORKING  4
 182 /*%<
 183  * The client object has received a request and is working
 184  * on it.  It has a view, and it may have any of a non-reset OPT,
 185  * recursion quota, and an outstanding write request.
 186  */
 187
 188 #define NS_CLIENTSTATE_MAX      9
 189 /*%<
 190  * Sentinel value used to indicate "no state".  When client->newstate
 191  * has this value, we are not attempting to exit the current state.
 192  * Must be greater than any valid state.
 193  */
 194
 195 /*
 196  * Enable ns_client_dropport() by default.
 197  */
 198 #ifndef NS_CLIENT_DROPPORT
 199 #define NS_CLIENT_DROPPORT 1
 200 #endif
 201
 202 unsigned int ns_client_requests;
 203
 204 static void client_read(ns_client_t *client);
 205 static void client_accept(ns_client_t *client);
 206 static void client_udprecv(ns_client_t *client);
 207 static void clientmgr_destroy(ns_clientmgr_t *manager);
 208 static isc_boolean_t exit_check(ns_client_t *client);
 209 static void ns_client_endrequest(ns_client_t *client);
 210 static void ns_client_checkactive(ns_client_t *client);
 211 static void client_start(isc_task_t *task, isc_event_t *event);
 212 static void client_request(isc_task_t *task, isc_event_t *event);
 213 static void ns_client_dumpmessage(ns_client_t *client, const char *reason);
 214
 215 void
 216 ns_client_recursing(ns_client_t *client) {
 217         REQUIRE(NS_CLIENT_VALID(client));
 218
 219         LOCK(&client->manager->lock);
 220         ISC_LIST_UNLINK(*client->list, client, link);
 221         ISC_LIST_APPEND(client->manager->recursing, client, link);
 222         client->list = &client->manager->recursing;
 223         UNLOCK(&client->manager->lock);
 224 }
 225
 226 void
 227 ns_client_killoldestquery(ns_client_t *client) {
 228         ns_client_t *oldest;
 229         REQUIRE(NS_CLIENT_VALID(client));
 230
 231         LOCK(&client->manager->lock);
 232         oldest = ISC_LIST_HEAD(client->manager->recursing);
 233         if (oldest != NULL) {
 234                 ns_query_cancel(oldest);
 235                 ISC_LIST_UNLINK(*oldest->list, oldest, link);
 236                 ISC_LIST_APPEND(client->manager->active, oldest, link);
 237                 oldest->list = &client->manager->active;
 238         }
 239         UNLOCK(&client->manager->lock);
 240 }
 241
 242 void
 243 ns_client_settimeout(ns_client_t *client, unsigned int seconds) {
 244         isc_result_t result;
 245         isc_interval_t interval;
 246
 247         isc_interval_set(&interval, seconds, 0);
 248         result = isc_timer_reset(client->timer, isc_timertype_once, NULL,
 249                                  &interval, ISC_FALSE);
 250         client->timerset = ISC_TRUE;
 251         if (result != ISC_R_SUCCESS) {
 252                 ns_client_log(client, NS_LOGCATEGORY_CLIENT,
 253                               NS_LOGMODULE_CLIENT, ISC_LOG_ERROR,
 254                               "setting timeout: %s",
 255                               isc_result_totext(result));
 256                 /* Continue anyway. */
 257         }
 258 }
 259
 260 /*%
 261  * Check for a deactivation or shutdown request and take appropriate
 262  * action.  Returns ISC_TRUE if either is in progress; in this case
 263  * the caller must no longer use the client object as it may have been
 264  * freed.
 265  */
 266 static isc_boolean_t
 267 exit_check(ns_client_t *client) {
 268         ns_clientmgr_t *locked_manager = NULL;
 269         ns_clientmgr_t *destroy_manager = NULL;
 270
 271         REQUIRE(NS_CLIENT_VALID(client));
 272
 273         if (client->state <= client->newstate)
 274                 return (ISC_FALSE); /* Business as usual. */
 275
 276         INSIST(client->newstate < NS_CLIENTSTATE_WORKING);
 277
 278         /*
 279          * We need to detach from the view early when shutting down
 280          * the server to break the following vicious circle:
 281          *
 282          *  - The resolver will not shut down until the view refcount is zero
 283          *  - The view refcount does not go to zero until all clients detach
 284          *  - The client does not detach from the view until references is zero
 285          *  - references does not go to zero until the resolver has shut down
 286          *
 287          * Keep the view attached until any outstanding updates complete.
 288          */
 289         if (client->nupdates == 0 &&
 290             client->newstate == NS_CLIENTSTATE_FREED && client->view != NULL)
 291                 dns_view_detach(&client->view);
 292
 293         if (client->state == NS_CLIENTSTATE_WORKING) {
 294                 INSIST(client->newstate <= NS_CLIENTSTATE_READING);
 295                 /*
 296                  * Let the update processing complete.
 297                  */
 298                 if (client->nupdates > 0)
 299                         return (ISC_TRUE);
 300                 /*
 301                  * We are trying to abort request processing.
 302                  */
 303                 if (client->nsends > 0) {
 304                         isc_socket_t *socket;
 305                         if (TCP_CLIENT(client))
 306                                 socket = client->tcpsocket;
 307                         else
 308                                 socket = client->udpsocket;
 309                         isc_socket_cancel(socket, client->task,
 310                                           ISC_SOCKCANCEL_SEND);
 311                 }
 312
 313                 if (! (client->nsends == 0 && client->nrecvs == 0 &&
 314                        client->references == 0))
 315                 {
 316                         /*
 317                          * Still waiting for I/O cancel completion.
 318                          * or lingering references.
 319                          */
 320                         return (ISC_TRUE);
 321                 }
 322                 /*
 323                  * I/O cancel is complete.  Burn down all state
 324                  * related to the current request.  Ensure that
 325                  * the client is on the active list and not the
 326                  * recursing list.
 327                  */
 328                 LOCK(&client->manager->lock);
 329                 if (client->list == &client->manager->recursing) {
 330                         ISC_LIST_UNLINK(*client->list, client, link);
 331                         ISC_LIST_APPEND(client->manager->active, client, link);
 332                         client->list = &client->manager->active;
 333                 }
 334                 UNLOCK(&client->manager->lock);
 335                 ns_client_endrequest(client);
 336
 337                 client->state = NS_CLIENTSTATE_READING;
 338                 INSIST(client->recursionquota == NULL);
 339                 if (NS_CLIENTSTATE_READING == client->newstate) {
 340                         client_read(client);
 341                         client->newstate = NS_CLIENTSTATE_MAX;
 342                         return (ISC_TRUE); /* We're done. */
 343                 }
 344         }
 345
 346         if (client->state == NS_CLIENTSTATE_READING) {
 347                 /*
 348                  * We are trying to abort the current TCP connection,
 349                  * if any.
 350                  */
 351                 INSIST(client->recursionquota == NULL);
 352                 INSIST(client->newstate <= NS_CLIENTSTATE_READY);
 353                 if (client->nreads > 0)
 354                         dns_tcpmsg_cancelread(&client->tcpmsg);
 355                 if (! client->nreads == 0) {
 356                         /* Still waiting for read cancel completion. */
 357                         return (ISC_TRUE);
 358                 }
 359
 360                 if (client->tcpmsg_valid) {
 361                         dns_tcpmsg_invalidate(&client->tcpmsg);
 362                         client->tcpmsg_valid = ISC_FALSE;
 363                 }
 364                 if (client->tcpsocket != NULL) {
 365                         CTRACE("closetcp");
 366                         isc_socket_detach(&client->tcpsocket);
 367                 }
 368
 369                 if (client->tcpquota != NULL)
 370                         isc_quota_detach(&client->tcpquota);
 371
 372                 if (client->timerset) {
 373                         (void)isc_timer_reset(client->timer,
 374                                               isc_timertype_inactive,
 375                                               NULL, NULL, ISC_TRUE);
 376                         client->timerset = ISC_FALSE;
 377                 }
 378
 379                 client->peeraddr_valid = ISC_FALSE;
 380
 381                 client->state = NS_CLIENTSTATE_READY;
 382                 INSIST(client->recursionquota == NULL);
 383
 384                 /*
 385                  * Now the client is ready to accept a new TCP connection
 386                  * or UDP request, but we may have enough clients doing
 387                  * that already.  Check whether this client needs to remain
 388                  * active and force it to go inactive if not.
 389                  */
 390                 ns_client_checkactive(client);
 391
 392                 if (NS_CLIENTSTATE_READY == client->newstate) {
 393                         if (TCP_CLIENT(client)) {
 394                                 client_accept(client);
 395                         } else
 396                                 client_udprecv(client);
 397                         client->newstate = NS_CLIENTSTATE_MAX;
 398                         return (ISC_TRUE);
 399                 }
 400         }
 401
 402         if (client->state == NS_CLIENTSTATE_READY) {
 403                 INSIST(client->newstate <= NS_CLIENTSTATE_INACTIVE);
 404                 /*
 405                  * We are trying to enter the inactive state.
 406                  */
 407                 if (client->naccepts > 0)
 408                         isc_socket_cancel(client->tcplistener, client->task,
 409                                           ISC_SOCKCANCEL_ACCEPT);
 410
 411                 if (! (client->naccepts == 0)) {
 412                         /* Still waiting for accept cancel completion. */
 413                         return (ISC_TRUE);
 414                 }
 415                 /* Accept cancel is complete. */
 416
 417                 if (client->nrecvs > 0)
 418                         isc_socket_cancel(client->udpsocket, client->task,
 419                                           ISC_SOCKCANCEL_RECV);
 420                 if (! (client->nrecvs == 0)) {
 421                         /* Still waiting for recv cancel completion. */
 422                         return (ISC_TRUE);
 423                 }
 424                 /* Recv cancel is complete. */
 425
 426                 if (client->nctls > 0) {
 427                         /* Still waiting for control event to be delivered */
 428                         return (ISC_TRUE);
 429                 }
 430
 431                 /* Deactivate the client. */
 432                 if (client->interface)
 433                         ns_interface_detach(&client->interface);
 434
 435                 INSIST(client->naccepts == 0);
 436                 INSIST(client->recursionquota == NULL);
 437                 if (client->tcplistener != NULL)
 438                         isc_socket_detach(&client->tcplistener);
 439
 440                 if (client->udpsocket != NULL)
 441                         isc_socket_detach(&client->udpsocket);
 442
 443                 if (client->dispatch != NULL)
 444                         dns_dispatch_detach(&client->dispatch);
 445
 446                 client->attributes = 0;
 447                 client->mortal = ISC_FALSE;
 448
 449                 LOCK(&client->manager->lock);
 450                 /*
 451                  * Put the client on the inactive list.  If we are aiming for
 452                  * the "freed" state, it will be removed from the inactive
 453                  * list shortly, and we need to keep the manager locked until
 454                  * that has been done, lest the manager decide to reactivate
 455                  * the dying client inbetween.
 456                  */
 457                 locked_manager = client->manager;
 458                 ISC_LIST_UNLINK(*client->list, client, link);
 459                 ISC_LIST_APPEND(client->manager->inactive, client, link);
 460                 client->list = &client->manager->inactive;
 461                 client->state = NS_CLIENTSTATE_INACTIVE;
 462                 INSIST(client->recursionquota == NULL);
 463
 464                 if (client->state == client->newstate) {
 465                         client->newstate = NS_CLIENTSTATE_MAX;
 466                         goto unlock;
 467                 }
 468         }
 469
 470         if (client->state == NS_CLIENTSTATE_INACTIVE) {
 471                 INSIST(client->newstate == NS_CLIENTSTATE_FREED);
 472                 /*
 473                  * We are trying to free the client.
 474                  *
 475                  * When "shuttingdown" is true, either the task has received
 476                  * its shutdown event or no shutdown event has ever been
 477                  * set up.  Thus, we have no outstanding shutdown
 478                  * event at this point.
 479                  */
 480                 REQUIRE(client->state == NS_CLIENTSTATE_INACTIVE);
 481
 482                 INSIST(client->recursionquota == NULL);
 483
 484                 ns_query_free(client);
 485                 isc_mem_put(client->mctx, client->recvbuf, RECV_BUFFER_SIZE);
 486                 isc_event_free((isc_event_t **)&client->sendevent);
 487                 isc_event_free((isc_event_t **)&client->recvevent);
 488                 isc_timer_detach(&client->timer);
 489
 490                 if (client->tcpbuf != NULL)
 491                         isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE);
 492                 if (client->opt != NULL) {
 493                         INSIST(dns_rdataset_isassociated(client->opt));
 494                         dns_rdataset_disassociate(client->opt);
 495                         dns_message_puttemprdataset(client->message, &client->opt);
 496                 }
 497                 dns_message_destroy(&client->message);
 498                 if (client->manager != NULL) {
 499                         ns_clientmgr_t *manager = client->manager;
 500                         if (locked_manager == NULL) {
 501                                 LOCK(&manager->lock);
 502                                 locked_manager = manager;
 503                         }
 504                         ISC_LIST_UNLINK(*client->list, client, link);
 505                         client->list = NULL;
 506                         if (manager->exiting &&
 507                             ISC_LIST_EMPTY(manager->active) &&
 508                             ISC_LIST_EMPTY(manager->inactive) &&
 509                             ISC_LIST_EMPTY(manager->recursing))
 510                                 destroy_manager = manager;
 511                 }
 512                 /*
 513                  * Detaching the task must be done after unlinking from
 514                  * the manager's lists because the manager accesses
 515                  * client->task.
 516                  */
 517                 if (client->task != NULL)
 518                         isc_task_detach(&client->task);
 519
 520                 CTRACE("free");
 521                 client->magic = 0;
 522                 isc_mem_putanddetach(&client->mctx, client, sizeof(*client));
 523
 524                 goto unlock;
 525         }
 526
 527  unlock:
 528         if (locked_manager != NULL) {
 529                 UNLOCK(&locked_manager->lock);
 530                 locked_manager = NULL;
 531         }
 532
 533         /*
 534          * Only now is it safe to destroy the client manager (if needed),
 535          * because we have accessed its lock for the last time.
 536          */
 537         if (destroy_manager != NULL)
 538                 clientmgr_destroy(destroy_manager);
 539
 540         return (ISC_TRUE);
 541 }
 542
 543 /*%
 544  * The client's task has received the client's control event
 545  * as part of the startup process.
 546  */
 547 static void
 548 client_start(isc_task_t *task, isc_event_t *event) {
 549         ns_client_t *client = (ns_client_t *) event->ev_arg;
 550
 551         INSIST(task == client->task);
 552
 553         UNUSED(task);
 554
 555         INSIST(client->nctls == 1);
 556         client->nctls--;
 557
 558         if (exit_check(client))
 559                 return;
 560
 561         if (TCP_CLIENT(client)) {
 562                 client_accept(client);
 563         } else {
 564                 client_udprecv(client);
 565         }
 566 }
 567
 568
 569 /*%
 570  * The client's task has received a shutdown event.
 571  */
 572 static void
 573 client_shutdown(isc_task_t *task, isc_event_t *event) {
 574         ns_client_t *client;
 575
 576         REQUIRE(event != NULL);
 577         REQUIRE(event->ev_type == ISC_TASKEVENT_SHUTDOWN);
 578         client = event->ev_arg;
 579         REQUIRE(NS_CLIENT_VALID(client));
 580         REQUIRE(task == client->task);
 581
 582         UNUSED(task);
 583
 584         CTRACE("shutdown");
 585
 586         isc_event_free(&event);
 587
 588         if (client->shutdown != NULL) {
 589                 (client->shutdown)(client->shutdown_arg, ISC_R_SHUTTINGDOWN);
 590                 client->shutdown = NULL;
 591                 client->shutdown_arg = NULL;
 592         }
 593
 594         client->newstate = NS_CLIENTSTATE_FREED;
 595         (void)exit_check(client);
 596 }
 597
 598 static void
 599 ns_client_endrequest(ns_client_t *client) {
 600         INSIST(client->naccepts == 0);
 601         INSIST(client->nreads == 0);
 602         INSIST(client->nsends == 0);
 603         INSIST(client->nrecvs == 0);
 604         INSIST(client->nupdates == 0);
 605         INSIST(client->state == NS_CLIENTSTATE_WORKING);
 606
 607         CTRACE("endrequest");
 608
 609         if (client->next != NULL) {
 610                 (client->next)(client);
 611                 client->next = NULL;
 612         }
 613
 614         if (client->view != NULL)
 615                 dns_view_detach(&client->view);
 616         if (client->opt != NULL) {
 617                 INSIST(dns_rdataset_isassociated(client->opt));
 618                 dns_rdataset_disassociate(client->opt);
 619                 dns_message_puttemprdataset(client->message, &client->opt);
 620         }
 621
 622         client->udpsize = 512;
 623         client->extflags = 0;
 624         client->ednsversion = -1;
 625         dns_message_reset(client->message, DNS_MESSAGE_INTENTPARSE);
 626
 627         if (client->recursionquota != NULL)
 628                 isc_quota_detach(&client->recursionquota);
 629
 630         /*
 631          * Clear all client attributes that are specific to
 632          * the request; that's all except the TCP flag.
 633          */
 634         client->attributes &= NS_CLIENTATTR_TCP;
 635 }
 636
 637 static void
 638 ns_client_checkactive(ns_client_t *client) {
 639         if (client->mortal) {
 640                 /*
 641                  * This client object should normally go inactive
 642                  * at this point, but if we have fewer active client
 643                  * objects than  desired due to earlier quota exhaustion,
 644                  * keep it active to make up for the shortage.
 645                  */
 646                 isc_boolean_t need_another_client = ISC_FALSE;
 647                 if (TCP_CLIENT(client)) {
 648                         LOCK(&client->interface->lock);
 649                         if (client->interface->ntcpcurrent <
 650                             client->interface->ntcptarget)
 651                                 need_another_client = ISC_TRUE;
 652                         UNLOCK(&client->interface->lock);
 653                 } else {
 654                         /*
 655                          * The UDP client quota is enforced by making
 656                          * requests fail rather than by not listening
 657                          * for new ones.  Therefore, there is always a
 658                          * full set of UDP clients listening.
 659                          */
 660                 }
 661                 if (! need_another_client) {
 662                         /*
 663                          * We don't need this client object.  Recycle it.
 664                          */
 665                         if (client->newstate >= NS_CLIENTSTATE_INACTIVE)
 666                                 client->newstate = NS_CLIENTSTATE_INACTIVE;
 667                 }
 668         }
 669 }
 670
 671 void
 672 ns_client_next(ns_client_t *client, isc_result_t result) {
 673         int newstate;
 674
 675         REQUIRE(NS_CLIENT_VALID(client));
 676         REQUIRE(client->state == NS_CLIENTSTATE_WORKING ||
 677                 client->state == NS_CLIENTSTATE_READING);
 678
 679         CTRACE("next");
 680
 681         if (result != ISC_R_SUCCESS)
 682                 ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
 683                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
 684                               "request failed: %s", isc_result_totext(result));
 685
 686         /*
 687          * An error processing a TCP request may have left
 688          * the connection out of sync.  To be safe, we always
 689          * sever the connection when result != ISC_R_SUCCESS.
 690          */
 691         if (result == ISC_R_SUCCESS && TCP_CLIENT(client))
 692                 newstate = NS_CLIENTSTATE_READING;
 693         else
 694                 newstate = NS_CLIENTSTATE_READY;
 695
 696         if (client->newstate > newstate)
 697                 client->newstate = newstate;
 698         (void)exit_check(client);
 699 }
 700
 701
 702 static void
 703 client_senddone(isc_task_t *task, isc_event_t *event) {
 704         ns_client_t *client;
 705         isc_socketevent_t *sevent = (isc_socketevent_t *) event;
 706
 707         REQUIRE(sevent != NULL);
 708         REQUIRE(sevent->ev_type == ISC_SOCKEVENT_SENDDONE);
 709         client = sevent->ev_arg;
 710         REQUIRE(NS_CLIENT_VALID(client));
 711         REQUIRE(task == client->task);
 712         REQUIRE(sevent == client->sendevent);
 713
 714         UNUSED(task);
 715
 716         CTRACE("senddone");
 717
 718         if (sevent->result != ISC_R_SUCCESS)
 719                 ns_client_log(client, NS_LOGCATEGORY_CLIENT,
 720                               NS_LOGMODULE_CLIENT, ISC_LOG_WARNING,
 721                               "error sending response: %s",
 722                               isc_result_totext(sevent->result));
 723
 724         INSIST(client->nsends > 0);
 725         client->nsends--;
 726
 727         if (client->tcpbuf != NULL) {
 728                 INSIST(TCP_CLIENT(client));
 729                 isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE);
 730                 client->tcpbuf = NULL;
 731         }
 732
 733         if (exit_check(client))
 734                 return;
 735
 736         ns_client_next(client, ISC_R_SUCCESS);
 737 }
 738
 739 /*%
 740  * We only want to fail with ISC_R_NOSPACE when called from
 741  * ns_client_sendraw() and not when called from ns_client_send(),
 742  * tcpbuffer is NULL when called from ns_client_sendraw() and
 743  * length != 0.  tcpbuffer != NULL when called from ns_client_send()
 744  * and length == 0.
 745  */
 746
 747 static isc_result_t
 748 client_allocsendbuf(ns_client_t *client, isc_buffer_t *buffer,
 749                     isc_buffer_t *tcpbuffer, isc_uint32_t length,
 750                     unsigned char *sendbuf, unsigned char **datap)
 751 {
 752         unsigned char *data;
 753         isc_uint32_t bufsize;
 754         isc_result_t result;
 755
 756         INSIST(datap != NULL);
 757         INSIST((tcpbuffer == NULL && length != 0) ||
 758                (tcpbuffer != NULL && length == 0));
 759
 760         if (TCP_CLIENT(client)) {
 761                 INSIST(client->tcpbuf == NULL);
 762                 if (length + 2 > TCP_BUFFER_SIZE) {
 763                         result = ISC_R_NOSPACE;
 764                         goto done;
 765                 }
 766                 client->tcpbuf = isc_mem_get(client->mctx, TCP_BUFFER_SIZE);
 767                 if (client->tcpbuf == NULL) {
 768                         result = ISC_R_NOMEMORY;
 769                         goto done;
 770                 }
 771                 data = client->tcpbuf;
 772                 if (tcpbuffer != NULL) {
 773                         isc_buffer_init(tcpbuffer, data, TCP_BUFFER_SIZE);
 774                         isc_buffer_init(buffer, data + 2, TCP_BUFFER_SIZE - 2);
 775                 } else {
 776                         isc_buffer_init(buffer, data, TCP_BUFFER_SIZE);
 777                         INSIST(length <= 0xffff);
 778                         isc_buffer_putuint16(buffer, (isc_uint16_t)length);
 779                 }
 780         } else {
 781                 data = sendbuf;
 782                 if (client->udpsize < SEND_BUFFER_SIZE)
 783                         bufsize = client->udpsize;
 784                 else
 785                         bufsize = SEND_BUFFER_SIZE;
 786                 if (length > bufsize) {
 787                         result = ISC_R_NOSPACE;
 788                         goto done;
 789                 }
 790                 isc_buffer_init(buffer, data, bufsize);
 791         }
 792         *datap = data;
 793         result = ISC_R_SUCCESS;
 794
 795  done:
 796         return (result);
 797 }
 798
 799 static isc_result_t
 800 client_sendpkg(ns_client_t *client, isc_buffer_t *buffer) {
 801         struct in6_pktinfo *pktinfo;
 802         isc_result_t result;
 803         isc_region_t r;
 804         isc_sockaddr_t *address;
 805         isc_socket_t *socket;
 806         isc_netaddr_t netaddr;
 807         int match;
 808         unsigned int sockflags = ISC_SOCKFLAG_IMMEDIATE;
 809
 810         if (TCP_CLIENT(client)) {
 811                 socket = client->tcpsocket;
 812                 address = NULL;
 813         } else {
 814                 socket = client->udpsocket;
 815                 address = &client->peeraddr;
 816
 817                 isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
 818                 if (ns_g_server->blackholeacl != NULL &&
 819                     dns_acl_match(&netaddr, NULL,
 820                                   ns_g_server->blackholeacl,
 821                                   &ns_g_server->aclenv,
 822                                   &match, NULL) == ISC_R_SUCCESS &&
 823                     match > 0)
 824                         return (DNS_R_BLACKHOLED);
 825                 sockflags |= ISC_SOCKFLAG_NORETRY;
 826         }
 827
 828         if ((client->attributes & NS_CLIENTATTR_PKTINFO) != 0 &&
 829             (client->attributes & NS_CLIENTATTR_MULTICAST) == 0)
 830                 pktinfo = &client->pktinfo;
 831         else
 832                 pktinfo = NULL;
 833
 834         isc_buffer_usedregion(buffer, &r);
 835
 836         CTRACE("sendto");
 837
 838         result = isc_socket_sendto2(socket, &r, client->task,
 839                                     address, pktinfo,
 840                                     client->sendevent, sockflags);
 841         if (result == ISC_R_SUCCESS || result == ISC_R_INPROGRESS) {
 842                 client->nsends++;
 843                 if (result == ISC_R_SUCCESS)
 844                         client_senddone(client->task,
 845                                         (isc_event_t *)client->sendevent);
 846                 result = ISC_R_SUCCESS;
 847         }
 848         return (result);
 849 }
 850
 851 void
 852 ns_client_sendraw(ns_client_t *client, dns_message_t *message) {
 853         isc_result_t result;
 854         unsigned char *data;
 855         isc_buffer_t buffer;
 856         isc_region_t r;
 857         isc_region_t *mr;
 858         unsigned char sendbuf[SEND_BUFFER_SIZE];
 859
 860         REQUIRE(NS_CLIENT_VALID(client));
 861
 862         CTRACE("sendraw");
 863
 864         mr = dns_message_getrawmessage(message);
 865         if (mr == NULL) {
 866                 result = ISC_R_UNEXPECTEDEND;
 867                 goto done;
 868         }
 869
 870         result = client_allocsendbuf(client, &buffer, NULL, mr->length,
 871                                      sendbuf, &data);
 872         if (result != ISC_R_SUCCESS)
 873                 goto done;
 874
 875         /*
 876          * Copy message to buffer and fixup id.
 877          */
 878         isc_buffer_availableregion(&buffer, &r);
 879         result = isc_buffer_copyregion(&buffer, mr);
 880         if (result != ISC_R_SUCCESS)
 881                 goto done;
 882         r.base[0] = (client->message->id >> 8) & 0xff;
 883         r.base[1] = client->message->id & 0xff;
 884
 885         result = client_sendpkg(client, &buffer);
 886         if (result == ISC_R_SUCCESS)
 887                 return;
 888
 889  done:
 890         if (client->tcpbuf != NULL) {
 891                 isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE);
 892                 client->tcpbuf = NULL;
 893         }
 894         ns_client_next(client, result);
 895 }
 896
 897 void
 898 ns_client_send(ns_client_t *client) {
 899         isc_result_t result;
 900         unsigned char *data;
 901         isc_buffer_t buffer;
 902         isc_buffer_t tcpbuffer;
 903         isc_region_t r;
 904         dns_compress_t cctx;
 905         isc_boolean_t cleanup_cctx = ISC_FALSE;
 906         unsigned char sendbuf[SEND_BUFFER_SIZE];
 907         unsigned int dnssec_opts;
 908         unsigned int preferred_glue;
 909
 910         REQUIRE(NS_CLIENT_VALID(client));
 911
 912         CTRACE("send");
 913
 914         if ((client->attributes & NS_CLIENTATTR_RA) != 0)
 915                 client->message->flags |= DNS_MESSAGEFLAG_RA;
 916
 917         if ((client->attributes & NS_CLIENTATTR_WANTDNSSEC) != 0)
 918                 dnssec_opts = 0;
 919         else
 920                 dnssec_opts = DNS_MESSAGERENDER_OMITDNSSEC;
 921
 922         preferred_glue = 0;
 923         if (client->view != NULL) {
 924                 if (client->view->preferred_glue == dns_rdatatype_a)
 925                         preferred_glue = DNS_MESSAGERENDER_PREFER_A;
 926                 else if (client->view->preferred_glue == dns_rdatatype_aaaa)
 927                         preferred_glue = DNS_MESSAGERENDER_PREFER_AAAA;
 928         }
 929
 930         /*
 931          * XXXRTH  The following doesn't deal with TCP buffer resizing.
 932          */
 933         result = client_allocsendbuf(client, &buffer, &tcpbuffer, 0,
 934                                      sendbuf, &data);
 935         if (result != ISC_R_SUCCESS)
 936                 goto done;
 937
 938         result = dns_compress_init(&cctx, -1, client->mctx);
 939         if (result != ISC_R_SUCCESS)
 940                 goto done;
 941         cleanup_cctx = ISC_TRUE;
 942
 943         result = dns_message_renderbegin(client->message, &cctx, &buffer);
 944         if (result != ISC_R_SUCCESS)
 945                 goto done;
 946         if (client->opt != NULL) {
 947                 result = dns_message_setopt(client->message, client->opt);
 948                 /*
 949                  * XXXRTH dns_message_setopt() should probably do this...
 950                  */
 951                 client->opt = NULL;
 952                 if (result != ISC_R_SUCCESS)
 953                         goto done;
 954         }
 955         result = dns_message_rendersection(client->message,
 956                                            DNS_SECTION_QUESTION, 0);
 957         if (result == ISC_R_NOSPACE) {
 958                 client->message->flags |= DNS_MESSAGEFLAG_TC;
 959                 goto renderend;
 960         }
 961         if (result != ISC_R_SUCCESS)
 962                 goto done;
 963         result = dns_message_rendersection(client->message,
 964                                            DNS_SECTION_ANSWER,
 965                                            DNS_MESSAGERENDER_PARTIAL |
 966                                            dnssec_opts);
 967         if (result == ISC_R_NOSPACE) {
 968                 client->message->flags |= DNS_MESSAGEFLAG_TC;
 969                 goto renderend;
 970         }
 971         if (result != ISC_R_SUCCESS)
 972                 goto done;
 973         result = dns_message_rendersection(client->message,
 974                                            DNS_SECTION_AUTHORITY,
 975                                            DNS_MESSAGERENDER_PARTIAL |
 976                                            dnssec_opts);
 977         if (result == ISC_R_NOSPACE) {
 978                 client->message->flags |= DNS_MESSAGEFLAG_TC;
 979                 goto renderend;
 980         }
 981         if (result != ISC_R_SUCCESS)
 982                 goto done;
 983         result = dns_message_rendersection(client->message,
 984                                            DNS_SECTION_ADDITIONAL,
 985                                            preferred_glue | dnssec_opts);
 986         if (result != ISC_R_SUCCESS && result != ISC_R_NOSPACE)
 987                 goto done;
 988  renderend:
 989         result = dns_message_renderend(client->message);
 990
 991         if (result != ISC_R_SUCCESS)
 992                 goto done;
 993
 994         if (cleanup_cctx) {
 995                 dns_compress_invalidate(&cctx);
 996                 cleanup_cctx = ISC_FALSE;
 997         }
 998
 999         if (TCP_CLIENT(client)) {
1000                 isc_buffer_usedregion(&buffer, &r);
1001                 isc_buffer_putuint16(&tcpbuffer, (isc_uint16_t) r.length);
1002                 isc_buffer_add(&tcpbuffer, r.length);
1003                 result = client_sendpkg(client, &tcpbuffer);
1004         } else
1005                 result = client_sendpkg(client, &buffer);
1006         if (result == ISC_R_SUCCESS)
1007                 return;
1008
1009  done:
1010         if (client->tcpbuf != NULL) {
1011                 isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE);
1012                 client->tcpbuf = NULL;
1013         }
1014
1015         if (cleanup_cctx)
1016                 dns_compress_invalidate(&cctx);
1017
1018         ns_client_next(client, result);
1019 }
1020
1021 #if NS_CLIENT_DROPPORT
1022 #define DROPPORT_NO             0
1023 #define DROPPORT_REQUEST        1
1024 #define DROPPORT_RESPONSE       2
1025 /*%
1026  * ns_client_dropport determines if certain requests / responses
1027  * should be dropped based on the port number.
1028  *
1029  * Returns:
1030  * \li  0:      Don't drop.
1031  * \li  1:      Drop request.
1032  * \li  2:      Drop (error) response.
1033  */
1034 static int
1035 ns_client_dropport(in_port_t port) {
1036         switch (port) {
1037         case 7: /* echo */
1038         case 13: /* daytime */
1039         case 19: /* chargen */
1040         case 37: /* time */
1041                 return (DROPPORT_REQUEST);
1042         case 464: /* kpasswd */
1043                 return (DROPPORT_RESPONSE);
1044         }
1045         return (DROPPORT_NO);
1046 }
1047 #endif
1048
1049 void
1050 ns_client_error(ns_client_t *client, isc_result_t result) {
1051         dns_rcode_t rcode;
1052         dns_message_t *message;
1053
1054         REQUIRE(NS_CLIENT_VALID(client));
1055
1056         CTRACE("error");
1057
1058         message = client->message;
1059         rcode = dns_result_torcode(result);
1060
1061 #if NS_CLIENT_DROPPORT
1062         /*
1063          * Don't send FORMERR to ports on the drop port list.
1064          */
1065         if (rcode == dns_rcode_formerr &&
1066             ns_client_dropport(isc_sockaddr_getport(&client->peeraddr)) !=
1067             DROPPORT_NO) {
1068                 char buf[64];
1069                 isc_buffer_t b;
1070
1071                 isc_buffer_init(&b, buf, sizeof(buf) - 1);
1072                 if (dns_rcode_totext(rcode, &b) != ISC_R_SUCCESS)
1073                         isc_buffer_putstr(&b, "UNKNOWN RCODE");
1074                 ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
1075                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
1076                               "dropped error (%.*s) response: suspicious port",
1077                               (int)isc_buffer_usedlength(&b), buf);
1078                 ns_client_next(client, ISC_R_SUCCESS);
1079                 return;
1080         }
1081 #endif
1082
1083         /*
1084          * Message may be an in-progress reply that we had trouble
1085          * with, in which case QR will be set.  We need to clear QR before
1086          * calling dns_message_reply() to avoid triggering an assertion.
1087          */
1088         message->flags &= ~DNS_MESSAGEFLAG_QR;
1089         /*
1090          * AA and AD shouldn't be set.
1091          */
1092         message->flags &= ~(DNS_MESSAGEFLAG_AA | DNS_MESSAGEFLAG_AD);
1093         result = dns_message_reply(message, ISC_TRUE);
1094         if (result != ISC_R_SUCCESS) {
1095                 /*
1096                  * It could be that we've got a query with a good header,
1097                  * but a bad question section, so we try again with
1098                  * want_question_section set to ISC_FALSE.
1099                  */
1100                 result = dns_message_reply(message, ISC_FALSE);
1101                 if (result != ISC_R_SUCCESS) {
1102                         ns_client_next(client, result);
1103                         return;
1104                 }
1105         }
1106         message->rcode = rcode;
1107
1108         /*
1109          * FORMERR loop avoidance:  If we sent a FORMERR message
1110          * with the same ID to the same client less than two
1111          * seconds ago, assume that we are in an infinite error
1112          * packet dialog with a server for some protocol whose
1113          * error responses look enough like DNS queries to
1114          * elicit a FORMERR response.  Drop a packet to break
1115          * the loop.
1116          */
1117         if (rcode == dns_rcode_formerr) {
1118                 if (isc_sockaddr_equal(&client->peeraddr,
1119                                        &client->formerrcache.addr) &&
1120                     message->id == client->formerrcache.id &&
1121                     client->requesttime - client->formerrcache.time < 2) {
1122                         /* Drop packet. */
1123                         ns_client_log(client, NS_LOGCATEGORY_CLIENT,
1124                                       NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
1125                                       "possible error packet loop, "
1126                                       "FORMERR dropped");
1127                         ns_client_next(client, result);
1128                         return;
1129                 }
1130                 client->formerrcache.addr = client->peeraddr;
1131                 client->formerrcache.time = client->requesttime;
1132                 client->formerrcache.id = message->id;
1133         }
1134         ns_client_send(client);
1135 }
1136
1137 static inline isc_result_t
1138 client_addopt(ns_client_t *client) {
1139         dns_rdataset_t *rdataset;
1140         dns_rdatalist_t *rdatalist;
1141         dns_rdata_t *rdata;
1142         isc_result_t result;
1143         dns_view_t *view;
1144         dns_resolver_t *resolver;
1145         isc_uint16_t udpsize;
1146
1147         REQUIRE(client->opt == NULL);   /* XXXRTH free old. */
1148
1149         rdatalist = NULL;
1150         result = dns_message_gettemprdatalist(client->message, &rdatalist);
1151         if (result != ISC_R_SUCCESS)
1152                 return (result);
1153         rdata = NULL;
1154         result = dns_message_gettemprdata(client->message, &rdata);
1155         if (result != ISC_R_SUCCESS)
1156                 return (result);
1157         rdataset = NULL;
1158         result = dns_message_gettemprdataset(client->message, &rdataset);
1159         if (result != ISC_R_SUCCESS)
1160                 return (result);
1161         dns_rdataset_init(rdataset);
1162
1163         rdatalist->type = dns_rdatatype_opt;
1164         rdatalist->covers = 0;
1165
1166         /*
1167          * Set the maximum UDP buffer size.
1168          */
1169         view = client->view;
1170         resolver = (view != NULL) ? view->resolver : NULL;
1171         if (resolver != NULL)
1172                 udpsize = dns_resolver_getudpsize(resolver);
1173         else
1174                 udpsize = ns_g_udpsize;
1175         rdatalist->rdclass = udpsize;
1176
1177         /*
1178          * Set EXTENDED-RCODE, VERSION and Z to 0.
1179          */
1180         rdatalist->ttl = (client->extflags & DNS_MESSAGEEXTFLAG_REPLYPRESERVE);
1181
1182         /*
1183          * No EDNS options in the default case.
1184          */
1185         rdata->data = NULL;
1186         rdata->length = 0;
1187         rdata->rdclass = rdatalist->rdclass;
1188         rdata->type = rdatalist->type;
1189         rdata->flags = 0;
1190
1191         ISC_LIST_INIT(rdatalist->rdata);
1192         ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
1193         RUNTIME_CHECK(dns_rdatalist_tordataset(rdatalist, rdataset)
1194                       == ISC_R_SUCCESS);
1195
1196         client->opt = rdataset;
1197
1198         return (ISC_R_SUCCESS);
1199 }
1200
1201 static inline isc_boolean_t
1202 allowed(isc_netaddr_t *addr, dns_name_t *signer, dns_acl_t *acl) {
1203         int match;
1204         isc_result_t result;
1205
1206         if (acl == NULL)
1207                 return (ISC_TRUE);
1208         result = dns_acl_match(addr, signer, acl, &ns_g_server->aclenv,
1209                                &match, NULL);
1210         if (result == ISC_R_SUCCESS && match > 0)
1211                 return (ISC_TRUE);
1212         return (ISC_FALSE);
1213 }
1214
1215 /*
1216  * Callback to see if a non-recursive query coming from 'srcaddr' to
1217  * 'destaddr', with optional key 'mykey' for class 'rdclass' would be
1218  * delivered to 'myview'.
1219  *
1220  * We run this unlocked as both the view list and the interface list
1221  * are updated when the approprite task has exclusivity.
1222  */
1223 isc_boolean_t
1224 ns_client_isself(dns_view_t *myview, dns_tsigkey_t *mykey,
1225                  isc_sockaddr_t *srcaddr, isc_sockaddr_t *dstaddr,
1226                  dns_rdataclass_t rdclass, void *arg)
1227 {
1228         dns_view_t *view;
1229         dns_tsigkey_t *key = NULL;
1230         dns_name_t *tsig = NULL;
1231         isc_netaddr_t netsrc;
1232         isc_netaddr_t netdst;
1233
1234         UNUSED(arg);
1235
1236         if (!ns_interfacemgr_listeningon(ns_g_server->interfacemgr, dstaddr))
1237                 return (ISC_FALSE);
1238
1239         isc_netaddr_fromsockaddr(&netsrc, srcaddr);
1240         isc_netaddr_fromsockaddr(&netdst, dstaddr);
1241
1242         for (view = ISC_LIST_HEAD(ns_g_server->viewlist);
1243              view != NULL;
1244              view = ISC_LIST_NEXT(view, link)) {
1245
1246                 if (view->matchrecursiveonly)
1247                         continue;
1248
1249                 if (rdclass != view->rdclass)
1250                         continue;
1251
1252                 if (mykey != NULL) {
1253                         isc_boolean_t match;
1254                         isc_result_t result;
1255
1256                         tsig = &mykey->name;
1257                         result = dns_view_gettsig(view, tsig, &key);
1258                         if (result != ISC_R_SUCCESS)
1259                                 continue;
1260                         match = dst_key_compare(mykey->key, key->key);
1261                         dns_tsigkey_detach(&key);
1262                         if (!match)
1263                                 continue;
1264                 }
1265
1266                 if (allowed(&netsrc, tsig, view->matchclients) &&
1267                     allowed(&netdst, tsig, view->matchdestinations))
1268                         break;
1269         }
1270         return (ISC_TF(view == myview));
1271 }
1272
1273 /*
1274  * Handle an incoming request event from the socket (UDP case)
1275  * or tcpmsg (TCP case).
1276  */
1277 static void
1278 client_request(isc_task_t *task, isc_event_t *event) {
1279         ns_client_t *client;
1280         isc_socketevent_t *sevent;
1281         isc_result_t result;
1282         isc_result_t sigresult = ISC_R_SUCCESS;
1283         isc_buffer_t *buffer;
1284         isc_buffer_t tbuffer;
1285         dns_view_t *view;
1286         dns_rdataset_t *opt;
1287         isc_boolean_t ra;       /* Recursion available. */
1288         isc_netaddr_t netaddr;
1289         isc_netaddr_t destaddr;
1290         int match;
1291         dns_messageid_t id;
1292         unsigned int flags;
1293         isc_boolean_t notimp;
1294
1295         REQUIRE(event != NULL);
1296         client = event->ev_arg;
1297         REQUIRE(NS_CLIENT_VALID(client));
1298         REQUIRE(task == client->task);
1299
1300         INSIST(client->recursionquota == NULL);
1301
1302         INSIST(client->state ==
1303                TCP_CLIENT(client) ?
1304                NS_CLIENTSTATE_READING :
1305                NS_CLIENTSTATE_READY);
1306
1307         ns_client_requests++;
1308
1309         if (event->ev_type == ISC_SOCKEVENT_RECVDONE) {
1310                 INSIST(!TCP_CLIENT(client));
1311                 sevent = (isc_socketevent_t *)event;
1312                 REQUIRE(sevent == client->recvevent);
1313                 isc_buffer_init(&tbuffer, sevent->region.base, sevent->n);
1314                 isc_buffer_add(&tbuffer, sevent->n);
1315                 buffer = &tbuffer;
1316                 result = sevent->result;
1317                 if (result == ISC_R_SUCCESS) {
1318                         client->peeraddr = sevent->address;
1319                         client->peeraddr_valid = ISC_TRUE;
1320                 }
1321                 if ((sevent->attributes & ISC_SOCKEVENTATTR_PKTINFO) != 0) {
1322                         client->attributes |= NS_CLIENTATTR_PKTINFO;
1323                         client->pktinfo = sevent->pktinfo;
1324                 }
1325                 if ((sevent->attributes & ISC_SOCKEVENTATTR_MULTICAST) != 0)
1326                         client->attributes |= NS_CLIENTATTR_MULTICAST;
1327                 client->nrecvs--;
1328         } else {
1329                 INSIST(TCP_CLIENT(client));
1330                 REQUIRE(event->ev_type == DNS_EVENT_TCPMSG);
1331                 REQUIRE(event->ev_sender == &client->tcpmsg);
1332                 buffer = &client->tcpmsg.buffer;
1333                 result = client->tcpmsg.result;
1334                 INSIST(client->nreads == 1);
1335                 /*
1336                  * client->peeraddr was set when the connection was accepted.
1337                  */
1338                 client->nreads--;
1339         }
1340
1341         if (exit_check(client))
1342                 goto cleanup;
1343         client->state = client->newstate = NS_CLIENTSTATE_WORKING;
1344
1345         isc_task_getcurrenttime(task, &client->requesttime);
1346         client->now = client->requesttime;
1347
1348         if (result != ISC_R_SUCCESS) {
1349                 if (TCP_CLIENT(client)) {
1350                         ns_client_next(client, result);
1351                 } else {
1352                         if  (result != ISC_R_CANCELED)
1353                                 isc_log_write(ns_g_lctx, NS_LOGCATEGORY_CLIENT,
1354                                               NS_LOGMODULE_CLIENT,
1355                                               ISC_LOG_ERROR,
1356                                               "UDP client handler shutting "
1357                                               "down due to fatal receive "
1358                                               "error: %s",
1359                                               isc_result_totext(result));
1360                         isc_task_shutdown(client->task);
1361                 }
1362                 goto cleanup;
1363         }
1364
1365         isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
1366
1367 #if NS_CLIENT_DROPPORT
1368         if (ns_client_dropport(isc_sockaddr_getport(&client->peeraddr)) ==
1369             DROPPORT_REQUEST) {
1370                 ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
1371                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
1372                               "dropped request: suspicious port");
1373                 ns_client_next(client, ISC_R_SUCCESS);
1374                 goto cleanup;
1375         }
1376 #endif
1377
1378         ns_client_log(client, NS_LOGCATEGORY_CLIENT,
1379                       NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
1380                       "%s request",
1381                       TCP_CLIENT(client) ? "TCP" : "UDP");
1382
1383         /*
1384          * Check the blackhole ACL for UDP only, since TCP is done in
1385          * client_newconn.
1386          */
1387         if (!TCP_CLIENT(client)) {
1388
1389                 if (ns_g_server->blackholeacl != NULL &&
1390                     dns_acl_match(&netaddr, NULL, ns_g_server->blackholeacl,
1391                                   &ns_g_server->aclenv,
1392                                   &match, NULL) == ISC_R_SUCCESS &&
1393                     match > 0)
1394                 {
1395                         ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
1396                                       NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
1397                                       "blackholed UDP datagram");
1398                         ns_client_next(client, ISC_R_SUCCESS);
1399                         goto cleanup;
1400                 }
1401         }
1402
1403         /*
1404          * Silently drop multicast requests for the present.
1405          * XXXMPA look at when/if mDNS spec stabilizes.
1406          */
1407         if ((client->attributes & NS_CLIENTATTR_MULTICAST) != 0) {
1408                 ns_client_log(client, NS_LOGCATEGORY_CLIENT,
1409                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
1410                               "dropping multicast request");
1411                 ns_client_next(client, DNS_R_REFUSED);
1412                 goto cleanup;
1413         }
1414
1415         result = dns_message_peekheader(buffer, &id, &flags);
1416         if (result != ISC_R_SUCCESS) {
1417                 /*
1418                  * There isn't enough header to determine whether
1419                  * this was a request or a response.  Drop it.
1420                  */
1421                 ns_client_next(client, result);
1422                 goto cleanup;
1423         }
1424
1425         /*
1426          * The client object handles requests, not responses.
1427          * If this is a UDP response, forward it to the dispatcher.
1428          * If it's a TCP response, discard it here.
1429          */
1430         if ((flags & DNS_MESSAGEFLAG_QR) != 0) {
1431                 if (TCP_CLIENT(client)) {
1432                         CTRACE("unexpected response");
1433                         ns_client_next(client, DNS_R_FORMERR);
1434                         goto cleanup;
1435                 } else {
1436                         dns_dispatch_importrecv(client->dispatch, event);
1437                         ns_client_next(client, ISC_R_SUCCESS);
1438                         goto cleanup;
1439                 }
1440         }
1441
1442         /*
1443          * It's a request.  Parse it.
1444          */
1445         result = dns_message_parse(client->message, buffer, 0);
1446         if (result != ISC_R_SUCCESS) {
1447                 /*
1448                  * Parsing the request failed.  Send a response
1449                  * (typically FORMERR or SERVFAIL).
1450                  */
1451                 ns_client_error(client, result);
1452                 goto cleanup;
1453         }
1454
1455         switch (client->message->opcode) {
1456         case dns_opcode_query:
1457         case dns_opcode_update:
1458         case dns_opcode_notify:
1459                 notimp = ISC_FALSE;
1460                 break;
1461         case dns_opcode_iquery:
1462         default:
1463                 notimp = ISC_TRUE;
1464                 break;
1465         }
1466
1467         client->message->rcode = dns_rcode_noerror;
1468
1469         /* RFC1123 section 6.1.3.2 */
1470         if ((client->attributes & NS_CLIENTATTR_MULTICAST) != 0)
1471                 client->message->flags &= ~DNS_MESSAGEFLAG_RD;
1472
1473         /*
1474          * Deal with EDNS.
1475          */
1476         opt = dns_message_getopt(client->message);
1477         if (opt != NULL) {
1478                 /*
1479                  * Set the client's UDP buffer size.
1480                  */
1481                 client->udpsize = opt->rdclass;
1482
1483                 /*
1484                  * If the requested UDP buffer size is less than 512,
1485                  * ignore it and use 512.
1486                  */
1487                 if (client->udpsize < 512)
1488                         client->udpsize = 512;
1489
1490                 /*
1491                  * Get the flags out of the OPT record.
1492                  */
1493                 client->extflags = (isc_uint16_t)(opt->ttl & 0xFFFF);
1494
1495                 /*
1496                  * Do we understand this version of EDNS?
1497                  *
1498                  * XXXRTH need library support for this!
1499                  */
1500                 client->ednsversion = (opt->ttl & 0x00FF0000) >> 16;
1501                 if (client->ednsversion > 0) {
1502                         result = client_addopt(client);
1503                         if (result == ISC_R_SUCCESS)
1504                                 result = DNS_R_BADVERS;
1505                         ns_client_error(client, result);
1506                         goto cleanup;
1507                 }
1508                 /*
1509                  * Create an OPT for our reply.
1510                  */
1511                 result = client_addopt(client);
1512                 if (result != ISC_R_SUCCESS) {
1513                         ns_client_error(client, result);
1514                         goto cleanup;
1515                 }
1516         }
1517
1518         if (client->message->rdclass == 0) {
1519                 ns_client_log(client, NS_LOGCATEGORY_CLIENT,
1520                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
1521                               "message class could not be determined");
1522                 ns_client_dumpmessage(client,
1523                                       "message class could not be determined");
1524                 ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_FORMERR);
1525                 goto cleanup;
1526         }
1527
1528         /*
1529          * Determine the destination address.  If the receiving interface is
1530          * bound to a specific address, we simply use it regardless of the
1531          * address family.  All IPv4 queries should fall into this case.
1532          * Otherwise, if this is a TCP query, get the address from the
1533          * receiving socket (this needs a system call and can be heavy).
1534          * For IPv6 UDP queries, we get this from the pktinfo structure (if
1535          * supported).
1536          * If all the attempts fail (this can happen due to memory shortage,
1537          * etc), we regard this as an error for safety.
1538          */
1539         if ((client->interface->flags & NS_INTERFACEFLAG_ANYADDR) == 0)
1540                 isc_netaddr_fromsockaddr(&destaddr, &client->interface->addr);
1541         else {
1542                 result = ISC_R_FAILURE;
1543
1544                 if (TCP_CLIENT(client)) {
1545                         isc_sockaddr_t destsockaddr;
1546
1547                         result = isc_socket_getsockname(client->tcpsocket,
1548                                                         &destsockaddr);
1549                         if (result == ISC_R_SUCCESS)
1550                                 isc_netaddr_fromsockaddr(&destaddr,
1551                                                          &destsockaddr);
1552                 }
1553                 if (result != ISC_R_SUCCESS &&
1554                     client->interface->addr.type.sa.sa_family == AF_INET6 &&
1555                     (client->attributes & NS_CLIENTATTR_PKTINFO) != 0) {
1556                         isc_uint32_t zone = 0;
1557
1558                         /*
1559                          * XXXJT technically, we should convert the receiving
1560                          * interface ID to a proper scope zone ID.  However,
1561                          * due to the fact there is no standard API for this,
1562                          * we only handle link-local addresses and use the
1563                          * interface index as link ID.  Despite the assumption,
1564                          * it should cover most typical cases.
1565                          */
1566                         if (IN6_IS_ADDR_LINKLOCAL(&client->pktinfo.ipi6_addr))
1567                                 zone = (isc_uint32_t)client->pktinfo.ipi6_ifindex;
1568
1569                         isc_netaddr_fromin6(&destaddr,
1570                                             &client->pktinfo.ipi6_addr);
1571                         isc_netaddr_setzone(&destaddr, zone);
1572                         result = ISC_R_SUCCESS;
1573                 }
1574                 if (result != ISC_R_SUCCESS) {
1575                         UNEXPECTED_ERROR(__FILE__, __LINE__,
1576                                          "failed to get request's "
1577                                          "destination: %s",
1578                                          isc_result_totext(result));
1579                         ns_client_next(client, ISC_R_SUCCESS);
1580                         goto cleanup;
1581                 }
1582         }
1583
1584         /*
1585          * Find a view that matches the client's source address.
1586          */
1587         for (view = ISC_LIST_HEAD(ns_g_server->viewlist);
1588              view != NULL;
1589              view = ISC_LIST_NEXT(view, link)) {
1590                 if (client->message->rdclass == view->rdclass ||
1591                     client->message->rdclass == dns_rdataclass_any)
1592                 {
1593                         dns_name_t *tsig = NULL;
1594                         sigresult = dns_message_rechecksig(client->message,
1595                                                            view);
1596                         if (sigresult == ISC_R_SUCCESS)
1597                                 tsig = client->message->tsigname;
1598
1599                         if (allowed(&netaddr, tsig, view->matchclients) &&
1600                             allowed(&destaddr, tsig, view->matchdestinations) &&
1601                             !((client->message->flags & DNS_MESSAGEFLAG_RD)
1602                               == 0 && view->matchrecursiveonly))
1603                         {
1604                                 dns_view_attach(view, &client->view);
1605                                 break;
1606                         }
1607                 }
1608         }
1609
1610         if (view == NULL) {
1611                 char classname[DNS_RDATACLASS_FORMATSIZE];
1612
1613                 /*
1614                  * Do a dummy TSIG verification attempt so that the
1615                  * response will have a TSIG if the query did, as
1616                  * required by RFC2845.
1617                  */
1618                 isc_buffer_t b;
1619                 isc_region_t *r;
1620
1621                 dns_message_resetsig(client->message);
1622
1623                 r = dns_message_getrawmessage(client->message);
1624                 isc_buffer_init(&b, r->base, r->length);
1625                 isc_buffer_add(&b, r->length);
1626                 (void)dns_tsig_verify(&b, client->message, NULL, NULL);
1627
1628                 dns_rdataclass_format(client->message->rdclass, classname,
1629                                       sizeof(classname));
1630                 ns_client_log(client, NS_LOGCATEGORY_CLIENT,
1631                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
1632                               "no matching view in class '%s'", classname);
1633                 ns_client_dumpmessage(client, "no matching view in class");
1634                 ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_REFUSED);
1635                 goto cleanup;
1636         }
1637
1638         ns_client_log(client, NS_LOGCATEGORY_CLIENT,
1639                       NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(5),
1640                       "using view '%s'", view->name);
1641
1642         /*
1643          * Check for a signature.  We log bad signatures regardless of
1644          * whether they ultimately cause the request to be rejected or
1645          * not.  We do not log the lack of a signature unless we are
1646          * debugging.
1647          */
1648         client->signer = NULL;
1649         dns_name_init(&client->signername, NULL);
1650         result = dns_message_signer(client->message, &client->signername);
1651         if (result == ISC_R_SUCCESS) {
1652                 ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
1653                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
1654                               "request has valid signature");
1655                 client->signer = &client->signername;
1656         } else if (result == ISC_R_NOTFOUND) {
1657                 ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
1658                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
1659                               "request is not signed");
1660         } else if (result == DNS_R_NOIDENTITY) {
1661                 ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
1662                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
1663                               "request is signed by a nonauthoritative key");
1664         } else {
1665                 char tsigrcode[64];
1666                 isc_buffer_t b;
1667                 dns_name_t *name = NULL;
1668                 dns_rcode_t status;
1669                 isc_result_t tresult;
1670
1671                 /* There is a signature, but it is bad. */
1672                 if (dns_message_gettsig(client->message, &name) != NULL) {
1673                         char namebuf[DNS_NAME_FORMATSIZE];
1674                         dns_name_format(name, namebuf, sizeof(namebuf));
1675                         status = client->message->tsigstatus;
1676                         isc_buffer_init(&b, tsigrcode, sizeof(tsigrcode) - 1);
1677                         tresult = dns_tsigrcode_totext(status, &b);
1678                         INSIST(tresult == ISC_R_SUCCESS);
1679                         tsigrcode[isc_buffer_usedlength(&b)] = '\0';
1680                         ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
1681                                       NS_LOGMODULE_CLIENT, ISC_LOG_ERROR,
1682                                       "request has invalid signature: "
1683                                       "TSIG %s: %s (%s)", namebuf,
1684                                       isc_result_totext(result), tsigrcode);
1685                 } else {
1686                         status = client->message->sig0status;
1687                         isc_buffer_init(&b, tsigrcode, sizeof(tsigrcode) - 1);
1688                         tresult = dns_tsigrcode_totext(status, &b);
1689                         INSIST(tresult == ISC_R_SUCCESS);
1690                         tsigrcode[isc_buffer_usedlength(&b)] = '\0';
1691                         ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
1692                                       NS_LOGMODULE_CLIENT, ISC_LOG_ERROR,
1693                                       "request has invalid signature: %s (%s)",
1694                                       isc_result_totext(result), tsigrcode);
1695                 }
1696                 /*
1697                  * Accept update messages signed by unknown keys so that
1698                  * update forwarding works transparently through slaves
1699                  * that don't have all the same keys as the master.
1700                  */
1701                 if (!(client->message->tsigstatus == dns_tsigerror_badkey &&
1702                       client->message->opcode == dns_opcode_update)) {
1703                         ns_client_error(client, sigresult);
1704                         goto cleanup;
1705                 }
1706         }
1707
1708         /*
1709          * Decide whether recursive service is available to this client.
1710          * We do this here rather than in the query code so that we can
1711          * set the RA bit correctly on all kinds of responses, not just
1712          * responses to ordinary queries.  Note if you can't query the
1713          * cache there is no point in setting RA.
1714          */
1715         ra = ISC_FALSE;
1716         if (client->view->resolver != NULL &&
1717             client->view->recursion == ISC_TRUE &&
1718             ns_client_checkaclsilent(client, client->view->recursionacl,
1719                                      ISC_TRUE) == ISC_R_SUCCESS &&
1720             ns_client_checkaclsilent(client, client->view->queryacl,
1721                                      ISC_TRUE) == ISC_R_SUCCESS)
1722                 ra = ISC_TRUE;
1723
1724         if (ra == ISC_TRUE)
1725                 client->attributes |= NS_CLIENTATTR_RA;
1726
1727         ns_client_log(client, DNS_LOGCATEGORY_SECURITY, NS_LOGMODULE_CLIENT,
1728                       ISC_LOG_DEBUG(3), ra ? "recursion available" :
1729                                              "recursion not available");
1730
1731         /*
1732          * Adjust maximum UDP response size for this client.
1733          */
1734         if (client->udpsize > 512) {
1735                 dns_peer_t *peer = NULL;
1736                 isc_uint16_t udpsize = view->maxudp;
1737                 (void) dns_peerlist_peerbyaddr(view->peers, &netaddr, &peer);
1738                 if (peer != NULL)
1739                         dns_peer_getmaxudp(peer, &udpsize);
1740                 if (client->udpsize > udpsize)
1741                         client->udpsize = udpsize;
1742         }
1743
1744         /*
1745          * Dispatch the request.
1746          */
1747         switch (client->message->opcode) {
1748         case dns_opcode_query:
1749                 CTRACE("query");
1750                 ns_query_start(client);
1751                 break;
1752         case dns_opcode_update:
1753                 CTRACE("update");
1754                 ns_client_settimeout(client, 60);
1755                 ns_update_start(client, sigresult);
1756                 break;
1757         case dns_opcode_notify:
1758                 CTRACE("notify");
1759                 ns_client_settimeout(client, 60);
1760                 ns_notify_start(client);
1761                 break;
1762         case dns_opcode_iquery:
1763                 CTRACE("iquery");
1764                 ns_client_error(client, DNS_R_NOTIMP);
1765                 break;
1766         default:
1767                 CTRACE("unknown opcode");
1768                 ns_client_error(client, DNS_R_NOTIMP);
1769         }
1770
1771  cleanup:
1772         return;
1773 }
1774
1775 static void
1776 client_timeout(isc_task_t *task, isc_event_t *event) {
1777         ns_client_t *client;
1778
1779         REQUIRE(event != NULL);
1780         REQUIRE(event->ev_type == ISC_TIMEREVENT_LIFE ||
1781                 event->ev_type == ISC_TIMEREVENT_IDLE);
1782         client = event->ev_arg;
1783         REQUIRE(NS_CLIENT_VALID(client));
1784         REQUIRE(task == client->task);
1785         REQUIRE(client->timer != NULL);
1786
1787         UNUSED(task);
1788
1789         CTRACE("timeout");
1790
1791         isc_event_free(&event);
1792
1793         if (client->shutdown != NULL) {
1794                 (client->shutdown)(client->shutdown_arg, ISC_R_TIMEDOUT);
1795                 client->shutdown = NULL;
1796                 client->shutdown_arg = NULL;
1797         }
1798
1799         if (client->newstate > NS_CLIENTSTATE_READY)
1800                 client->newstate = NS_CLIENTSTATE_READY;
1801         (void)exit_check(client);
1802 }
1803
1804 static isc_result_t
1805 get_clientmctx(ns_clientmgr_t *manager, isc_mem_t **mctxp) {
1806         isc_mem_t *clientmctx;
1807 #if NMCTXS > 0
1808         isc_result_t result;
1809 #endif
1810
1811         /*
1812          * Caller must be holding the manager lock.
1813          */
1814 #if NMCTXS > 0
1815         INSIST(manager->nextmctx < NMCTXS);
1816         clientmctx = manager->mctxpool[manager->nextmctx];
1817         if (clientmctx == NULL) {
1818                 result = isc_mem_create(0, 0, &clientmctx);
1819                 if (result != ISC_R_SUCCESS)
1820                         return (result);
1821
1822                 manager->mctxpool[manager->nextmctx] = clientmctx;
1823         }
1824         manager->nextmctx++;
1825         if (manager->nextmctx == NMCTXS)
1826                 manager->nextmctx = 0;
1827 #else
1828         clientmctx = manager->mctx;
1829 #endif
1830
1831         isc_mem_attach(clientmctx, mctxp);
1832
1833         return (ISC_R_SUCCESS);
1834 }
1835
1836 static isc_result_t
1837 client_create(ns_clientmgr_t *manager, ns_client_t **clientp) {
1838         ns_client_t *client;
1839         isc_result_t result;
1840         isc_mem_t *mctx = NULL;
1841
1842         /*
1843          * Caller must be holding the manager lock.
1844          *
1845          * Note: creating a client does not add the client to the
1846          * manager's client list or set the client's manager pointer.
1847          * The caller is responsible for that.
1848          */
1849
1850         REQUIRE(clientp != NULL && *clientp == NULL);
1851
1852         result = get_clientmctx(manager, &mctx);
1853         if (result != ISC_R_SUCCESS)
1854                 return (result);
1855
1856         client = isc_mem_get(mctx, sizeof(*client));
1857         if (client == NULL) {
1858                 isc_mem_detach(&mctx);
1859                 return (ISC_R_NOMEMORY);
1860         }
1861         client->mctx = mctx;
1862
1863         client->task = NULL;
1864         result = isc_task_create(manager->taskmgr, 0, &client->task);
1865         if (result != ISC_R_SUCCESS)
1866                 goto cleanup_client;
1867         isc_task_setname(client->task, "client", client);
1868
1869         client->timer = NULL;
1870         result = isc_timer_create(manager->timermgr, isc_timertype_inactive,
1871                                   NULL, NULL, client->task, client_timeout,
1872                                   client, &client->timer);
1873         if (result != ISC_R_SUCCESS)
1874                 goto cleanup_task;
1875         client->timerset = ISC_FALSE;
1876
1877         client->message = NULL;
1878         result = dns_message_create(client->mctx, DNS_MESSAGE_INTENTPARSE,
1879                                     &client->message);
1880         if (result != ISC_R_SUCCESS)
1881                 goto cleanup_timer;
1882
1883         /* XXXRTH  Hardwired constants */
1884
1885         client->sendevent = (isc_socketevent_t *)
1886                             isc_event_allocate(client->mctx, client,
1887                                                ISC_SOCKEVENT_SENDDONE,
1888                                                client_senddone, client,
1889                                                sizeof(isc_socketevent_t));
1890         if (client->sendevent == NULL) {
1891                 result = ISC_R_NOMEMORY;
1892                 goto cleanup_message;
1893         }
1894
1895         client->recvbuf = isc_mem_get(client->mctx, RECV_BUFFER_SIZE);
1896         if  (client->recvbuf == NULL) {
1897                 result = ISC_R_NOMEMORY;
1898                 goto cleanup_sendevent;
1899         }
1900
1901         client->recvevent = (isc_socketevent_t *)
1902                             isc_event_allocate(client->mctx, client,
1903                                                ISC_SOCKEVENT_RECVDONE,
1904                                                client_request, client,
1905                                                sizeof(isc_socketevent_t));
1906         if (client->recvevent == NULL) {
1907                 result = ISC_R_NOMEMORY;
1908                 goto cleanup_recvbuf;
1909         }
1910
1911         client->magic = NS_CLIENT_MAGIC;
1912         client->manager = NULL;
1913         client->state = NS_CLIENTSTATE_INACTIVE;
1914         client->newstate = NS_CLIENTSTATE_MAX;
1915         client->naccepts = 0;
1916         client->nreads = 0;
1917         client->nsends = 0;
1918         client->nrecvs = 0;
1919         client->nupdates = 0;
1920         client->nctls = 0;
1921         client->references = 0;
1922         client->attributes = 0;
1923         client->view = NULL;
1924         client->dispatch = NULL;
1925         client->udpsocket = NULL;
1926         client->tcplistener = NULL;
1927         client->tcpsocket = NULL;
1928         client->tcpmsg_valid = ISC_FALSE;
1929         client->tcpbuf = NULL;
1930         client->opt = NULL;
1931         client->udpsize = 512;
1932         client->extflags = 0;
1933         client->ednsversion = -1;
1934         client->next = NULL;
1935         client->shutdown = NULL;
1936         client->shutdown_arg = NULL;
1937         dns_name_init(&client->signername, NULL);
1938         client->mortal = ISC_FALSE;
1939         client->tcpquota = NULL;
1940         client->recursionquota = NULL;
1941         client->interface = NULL;
1942         client->peeraddr_valid = ISC_FALSE;
1943         ISC_EVENT_INIT(&client->ctlevent, sizeof(client->ctlevent), 0, NULL,
1944                        NS_EVENT_CLIENTCONTROL, client_start, client, client,
1945                        NULL, NULL);
1946         /*
1947          * Initialize FORMERR cache to sentinel value that will not match
1948          * any actual FORMERR response.
1949          */
1950         isc_sockaddr_any(&client->formerrcache.addr);
1951         client->formerrcache.time = 0;
1952         client->formerrcache.id = 0;
1953         ISC_LINK_INIT(client, link);
1954         client->list = NULL;
1955
1956         /*
1957          * We call the init routines for the various kinds of client here,
1958          * after we have created an otherwise valid client, because some
1959          * of them call routines that REQUIRE(NS_CLIENT_VALID(client)).
1960          */
1961         result = ns_query_init(client);
1962         if (result != ISC_R_SUCCESS)
1963                 goto cleanup_recvevent;
1964
1965         result = isc_task_onshutdown(client->task, client_shutdown, client);
1966         if (result != ISC_R_SUCCESS)
1967                 goto cleanup_query;
1968
1969         CTRACE("create");
1970
1971         *clientp = client;
1972
1973         return (ISC_R_SUCCESS);
1974
1975  cleanup_query:
1976         ns_query_free(client);
1977
1978  cleanup_recvevent:
1979         isc_event_free((isc_event_t **)&client->recvevent);
1980
1981  cleanup_recvbuf:
1982         isc_mem_put(client->mctx, client->recvbuf, RECV_BUFFER_SIZE);
1983
1984  cleanup_sendevent:
1985         isc_event_free((isc_event_t **)&client->sendevent);
1986
1987         client->magic = 0;
1988
1989  cleanup_message:
1990         dns_message_destroy(&client->message);
1991
1992  cleanup_timer:
1993         isc_timer_detach(&client->timer);
1994
1995  cleanup_task:
1996         isc_task_detach(&client->task);
1997
1998  cleanup_client:
1999         isc_mem_putanddetach(&client->mctx, client, sizeof(*client));
2000
2001         return (result);
2002 }
2003
2004 static void
2005 client_read(ns_client_t *client) {
2006         isc_result_t result;
2007
2008         CTRACE("read");
2009
2010         result = dns_tcpmsg_readmessage(&client->tcpmsg, client->task,
2011                                         client_request, client);
2012         if (result != ISC_R_SUCCESS)
2013                 goto fail;
2014
2015         /*
2016          * Set a timeout to limit the amount of time we will wait
2017          * for a request on this TCP connection.
2018          */
2019         ns_client_settimeout(client, 30);
2020
2021         client->state = client->newstate = NS_CLIENTSTATE_READING;
2022         INSIST(client->nreads == 0);
2023         INSIST(client->recursionquota == NULL);
2024         client->nreads++;
2025
2026         return;
2027  fail:
2028         ns_client_next(client, result);
2029 }
2030
2031 static void
2032 client_newconn(isc_task_t *task, isc_event_t *event) {
2033         ns_client_t *client = event->ev_arg;
2034         isc_socket_newconnev_t *nevent = (isc_socket_newconnev_t *)event;
2035         isc_result_t result;
2036
2037         REQUIRE(event->ev_type == ISC_SOCKEVENT_NEWCONN);
2038         REQUIRE(NS_CLIENT_VALID(client));
2039         REQUIRE(client->task == task);
2040
2041         UNUSED(task);
2042
2043         INSIST(client->state == NS_CLIENTSTATE_READY);
2044
2045         INSIST(client->naccepts == 1);
2046         client->naccepts--;
2047
2048         LOCK(&client->interface->lock);
2049         INSIST(client->interface->ntcpcurrent > 0);
2050         client->interface->ntcpcurrent--;
2051         UNLOCK(&client->interface->lock);
2052
2053         /*
2054          * We must take ownership of the new socket before the exit
2055          * check to make sure it gets destroyed if we decide to exit.
2056          */
2057         if (nevent->result == ISC_R_SUCCESS) {
2058                 client->tcpsocket = nevent->newsocket;
2059                 client->state = NS_CLIENTSTATE_READING;
2060                 INSIST(client->recursionquota == NULL);
2061
2062                 (void)isc_socket_getpeername(client->tcpsocket,
2063                                              &client->peeraddr);
2064                 client->peeraddr_valid = ISC_TRUE;
2065                 ns_client_log(client, NS_LOGCATEGORY_CLIENT,
2066                            NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
2067                            "new TCP connection");
2068         } else {
2069                 /*
2070                  * XXXRTH  What should we do?  We're trying to accept but
2071                  *         it didn't work.  If we just give up, then TCP
2072                  *         service may eventually stop.
2073                  *
2074                  *         For now, we just go idle.
2075                  *
2076                  *         Going idle is probably the right thing if the
2077                  *         I/O was canceled.
2078                  */
2079                 ns_client_log(client, NS_LOGCATEGORY_CLIENT,
2080                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
2081                               "accept failed: %s",
2082                               isc_result_totext(nevent->result));
2083         }
2084
2085         if (exit_check(client))
2086                 goto freeevent;
2087
2088         if (nevent->result == ISC_R_SUCCESS) {
2089                 int match;
2090                 isc_netaddr_t netaddr;
2091
2092                 isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
2093
2094                 if (ns_g_server->blackholeacl != NULL &&
2095                     dns_acl_match(&netaddr, NULL,
2096                                   ns_g_server->blackholeacl,
2097                                   &ns_g_server->aclenv,
2098                                   &match, NULL) == ISC_R_SUCCESS &&
2099                     match > 0)
2100                 {
2101                         ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
2102                                       NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
2103                                       "blackholed connection attempt");
2104                         client->newstate = NS_CLIENTSTATE_READY;
2105                         (void)exit_check(client);
2106                         goto freeevent;
2107                 }
2108
2109                 INSIST(client->tcpmsg_valid == ISC_FALSE);
2110                 dns_tcpmsg_init(client->mctx, client->tcpsocket,
2111                                 &client->tcpmsg);
2112                 client->tcpmsg_valid = ISC_TRUE;
2113
2114                 /*
2115                  * Let a new client take our place immediately, before
2116                  * we wait for a request packet.  If we don't,
2117                  * telnetting to port 53 (once per CPU) will
2118                  * deny service to legititmate TCP clients.
2119                  */
2120                 result = isc_quota_attach(&ns_g_server->tcpquota,
2121                                           &client->tcpquota);
2122                 if (result == ISC_R_SUCCESS)
2123                         result = ns_client_replace(client);
2124                 if (result != ISC_R_SUCCESS) {
2125                         ns_client_log(client, NS_LOGCATEGORY_CLIENT,
2126                                       NS_LOGMODULE_CLIENT, ISC_LOG_WARNING,
2127                                       "no more TCP clients: %s",
2128                                       isc_result_totext(result));
2129                 }
2130
2131                 client_read(client);
2132         }
2133
2134  freeevent:
2135         isc_event_free(&event);
2136 }
2137
2138 static void
2139 client_accept(ns_client_t *client) {
2140         isc_result_t result;
2141
2142         CTRACE("accept");
2143
2144         result = isc_socket_accept(client->tcplistener, client->task,
2145                                    client_newconn, client);
2146         if (result != ISC_R_SUCCESS) {
2147                 UNEXPECTED_ERROR(__FILE__, __LINE__,
2148                                  "isc_socket_accept() failed: %s",
2149                                  isc_result_totext(result));
2150                 /*
2151                  * XXXRTH  What should we do?  We're trying to accept but
2152                  *         it didn't work.  If we just give up, then TCP
2153                  *         service may eventually stop.
2154                  *
2155                  *         For now, we just go idle.
2156                  */
2157                 return;
2158         }
2159         INSIST(client->naccepts == 0);
2160         client->naccepts++;
2161         LOCK(&client->interface->lock);
2162         client->interface->ntcpcurrent++;
2163         UNLOCK(&client->interface->lock);
2164 }
2165
2166 static void
2167 client_udprecv(ns_client_t *client) {
2168         isc_result_t result;
2169         isc_region_t r;
2170
2171         CTRACE("udprecv");
2172
2173         r.base = client->recvbuf;
2174         r.length = RECV_BUFFER_SIZE;
2175         result = isc_socket_recv2(client->udpsocket, &r, 1,
2176                                   client->task, client->recvevent, 0);
2177         if (result != ISC_R_SUCCESS) {
2178                 UNEXPECTED_ERROR(__FILE__, __LINE__,
2179                                  "isc_socket_recv2() failed: %s",
2180                                  isc_result_totext(result));
2181                 /*
2182                  * This cannot happen in the current implementation, since
2183                  * isc_socket_recv2() cannot fail if flags == 0.
2184                  *
2185                  * If this does fail, we just go idle.
2186                  */
2187                 return;
2188         }
2189         INSIST(client->nrecvs == 0);
2190         client->nrecvs++;
2191 }
2192
2193 void
2194 ns_client_attach(ns_client_t *source, ns_client_t **targetp) {
2195         REQUIRE(NS_CLIENT_VALID(source));
2196         REQUIRE(targetp != NULL && *targetp == NULL);
2197
2198         source->references++;
2199         ns_client_log(source, NS_LOGCATEGORY_CLIENT,
2200                       NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
2201                       "ns_client_attach: ref = %d", source->references);
2202         *targetp = source;
2203 }
2204
2205 void
2206 ns_client_detach(ns_client_t **clientp) {
2207         ns_client_t *client = *clientp;
2208
2209         client->references--;
2210         INSIST(client->references >= 0);
2211         *clientp = NULL;
2212         ns_client_log(client, NS_LOGCATEGORY_CLIENT,
2213                       NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
2214                       "ns_client_detach: ref = %d", client->references);
2215         (void)exit_check(client);
2216 }
2217
2218 isc_boolean_t
2219 ns_client_shuttingdown(ns_client_t *client) {
2220         return (ISC_TF(client->newstate == NS_CLIENTSTATE_FREED));
2221 }
2222
2223 isc_result_t
2224 ns_client_replace(ns_client_t *client) {
2225         isc_result_t result;
2226
2227         CTRACE("replace");
2228
2229         result = ns_clientmgr_createclients(client->manager,
2230                                             1, client->interface,
2231                                             (TCP_CLIENT(client) ?
2232                                              ISC_TRUE : ISC_FALSE));
2233         if (result != ISC_R_SUCCESS)
2234                 return (result);
2235
2236         /*
2237          * The responsibility for listening for new requests is hereby
2238          * transferred to the new client.  Therefore, the old client
2239          * should refrain from listening for any more requests.
2240          */
2241         client->mortal = ISC_TRUE;
2242
2243         return (ISC_R_SUCCESS);
2244 }
2245
2246 /***
2247  *** Client Manager
2248  ***/
2249
2250 static void
2251 clientmgr_destroy(ns_clientmgr_t *manager) {
2252 #if NMCTXS > 0
2253         int i;
2254 #endif
2255
2256         REQUIRE(ISC_LIST_EMPTY(manager->active));
2257         REQUIRE(ISC_LIST_EMPTY(manager->inactive));
2258         REQUIRE(ISC_LIST_EMPTY(manager->recursing));
2259
2260         MTRACE("clientmgr_destroy");
2261
2262 #if NMCTXS > 0
2263         for (i = 0; i < NMCTXS; i++) {
2264                 if (manager->mctxpool[i] != NULL)
2265                         isc_mem_detach(&manager->mctxpool[i]);
2266         }
2267 #endif
2268
2269         DESTROYLOCK(&manager->lock);
2270         manager->magic = 0;
2271         isc_mem_put(manager->mctx, manager, sizeof(*manager));
2272 }
2273
2274 isc_result_t
2275 ns_clientmgr_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
2276                     isc_timermgr_t *timermgr, ns_clientmgr_t **managerp)
2277 {
2278         ns_clientmgr_t *manager;
2279         isc_result_t result;
2280 #if NMCTXS > 0
2281         int i;
2282 #endif
2283
2284         manager = isc_mem_get(mctx, sizeof(*manager));
2285         if (manager == NULL)
2286                 return (ISC_R_NOMEMORY);
2287
2288         result = isc_mutex_init(&manager->lock);
2289         if (result != ISC_R_SUCCESS)
2290                 goto cleanup_manager;
2291
2292         manager->mctx = mctx;
2293         manager->taskmgr = taskmgr;
2294         manager->timermgr = timermgr;
2295         manager->exiting = ISC_FALSE;
2296         ISC_LIST_INIT(manager->active);
2297         ISC_LIST_INIT(manager->inactive);
2298         ISC_LIST_INIT(manager->recursing);
2299 #if NMCTXS > 0
2300         manager->nextmctx = 0;
2301         for (i = 0; i < NMCTXS; i++)
2302                 manager->mctxpool[i] = NULL; /* will be created on-demand */
2303 #endif
2304         manager->magic = MANAGER_MAGIC;
2305
2306         MTRACE("create");
2307
2308         *managerp = manager;
2309
2310         return (ISC_R_SUCCESS);
2311
2312  cleanup_manager:
2313         isc_mem_put(manager->mctx, manager, sizeof(*manager));
2314
2315         return (result);
2316 }
2317
2318 void
2319 ns_clientmgr_destroy(ns_clientmgr_t **managerp) {
2320         ns_clientmgr_t *manager;
2321         ns_client_t *client;
2322         isc_boolean_t need_destroy = ISC_FALSE;
2323
2324         REQUIRE(managerp != NULL);
2325         manager = *managerp;
2326         REQUIRE(VALID_MANAGER(manager));
2327
2328         MTRACE("destroy");
2329
2330         LOCK(&manager->lock);
2331
2332         manager->exiting = ISC_TRUE;
2333
2334         for (client = ISC_LIST_HEAD(manager->recursing);
2335              client != NULL;
2336              client = ISC_LIST_NEXT(client, link))
2337                 isc_task_shutdown(client->task);
2338
2339         for (client = ISC_LIST_HEAD(manager->active);
2340              client != NULL;
2341              client = ISC_LIST_NEXT(client, link))
2342                 isc_task_shutdown(client->task);
2343
2344         for (client = ISC_LIST_HEAD(manager->inactive);
2345              client != NULL;
2346              client = ISC_LIST_NEXT(client, link))
2347                 isc_task_shutdown(client->task);
2348
2349         if (ISC_LIST_EMPTY(manager->active) &&
2350             ISC_LIST_EMPTY(manager->inactive) &&
2351             ISC_LIST_EMPTY(manager->recursing))
2352                 need_destroy = ISC_TRUE;
2353
2354         UNLOCK(&manager->lock);
2355
2356         if (need_destroy)
2357                 clientmgr_destroy(manager);
2358
2359         *managerp = NULL;
2360 }
2361
2362 isc_result_t
2363 ns_clientmgr_createclients(ns_clientmgr_t *manager, unsigned int n,
2364                            ns_interface_t *ifp, isc_boolean_t tcp)
2365 {
2366         isc_result_t result = ISC_R_SUCCESS;
2367         unsigned int i;
2368         ns_client_t *client;
2369
2370         REQUIRE(VALID_MANAGER(manager));
2371         REQUIRE(n > 0);
2372
2373         MTRACE("createclients");
2374
2375         /*
2376          * We MUST lock the manager lock for the entire client creation
2377          * process.  If we didn't do this, then a client could get a
2378          * shutdown event and disappear out from under us.
2379          */
2380
2381         LOCK(&manager->lock);
2382
2383         for (i = 0; i < n; i++) {
2384                 isc_event_t *ev;
2385                 /*
2386                  * Allocate a client.  First try to get a recycled one;
2387                  * if that fails, make a new one.
2388                  */
2389                 client = ISC_LIST_HEAD(manager->inactive);
2390                 if (client != NULL) {
2391                         MTRACE("recycle");
2392                         ISC_LIST_UNLINK(manager->inactive, client, link);
2393                         client->list = NULL;
2394                 } else {
2395                         MTRACE("create new");
2396                         result = client_create(manager, &client);
2397                         if (result != ISC_R_SUCCESS)
2398                                 break;
2399                 }
2400
2401                 ns_interface_attach(ifp, &client->interface);
2402                 client->state = NS_CLIENTSTATE_READY;
2403                 INSIST(client->recursionquota == NULL);
2404
2405                 if (tcp) {
2406                         client->attributes |= NS_CLIENTATTR_TCP;
2407                         isc_socket_attach(ifp->tcpsocket,
2408                                           &client->tcplistener);
2409                 } else {
2410                         isc_socket_t *sock;
2411
2412                         dns_dispatch_attach(ifp->udpdispatch,
2413                                             &client->dispatch);
2414                         sock = dns_dispatch_getsocket(client->dispatch);
2415                         isc_socket_attach(sock, &client->udpsocket);
2416                 }
2417                 client->manager = manager;
2418                 ISC_LIST_APPEND(manager->active, client, link);
2419                 client->list = &manager->active;
2420
2421                 INSIST(client->nctls == 0);
2422                 client->nctls++;
2423                 ev = &client->ctlevent;
2424                 isc_task_send(client->task, &ev);
2425         }
2426         if (i != 0) {
2427                 /*
2428                  * We managed to create at least one client, so we
2429                  * declare victory.
2430                  */
2431                 result = ISC_R_SUCCESS;
2432         }
2433
2434         UNLOCK(&manager->lock);
2435
2436         return (result);
2437 }
2438
2439 isc_sockaddr_t *
2440 ns_client_getsockaddr(ns_client_t *client) {
2441         return (&client->peeraddr);
2442 }
2443
2444 isc_result_t
2445 ns_client_checkaclsilent(ns_client_t *client, dns_acl_t *acl,
2446                          isc_boolean_t default_allow)
2447 {
2448         isc_result_t result;
2449         int match;
2450         isc_netaddr_t netaddr;
2451
2452         if (acl == NULL) {
2453                 if (default_allow)
2454                         goto allow;
2455                 else
2456                         goto deny;
2457         }
2458
2459         isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
2460
2461         result = dns_acl_match(&netaddr, client->signer, acl,
2462                                &ns_g_server->aclenv,
2463                                &match, NULL);
2464         if (result != ISC_R_SUCCESS)
2465                 goto deny; /* Internal error, already logged. */
2466         if (match > 0)
2467                 goto allow;
2468         goto deny; /* Negative match or no match. */
2469
2470  allow:
2471         return (ISC_R_SUCCESS);
2472
2473  deny:
2474         return (DNS_R_REFUSED);
2475 }
2476
2477 isc_result_t
2478 ns_client_checkacl(ns_client_t *client,
2479                    const char *opname, dns_acl_t *acl,
2480                    isc_boolean_t default_allow, int log_level)
2481 {
2482         isc_result_t result =
2483                 ns_client_checkaclsilent(client, acl, default_allow);
2484
2485         if (result == ISC_R_SUCCESS)
2486                 ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
2487                               NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
2488                               "%s approved", opname);
2489         else
2490                 ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
2491                               NS_LOGMODULE_CLIENT,
2492                               log_level, "%s denied", opname);
2493         return (result);
2494 }
2495
2496 static void
2497 ns_client_name(ns_client_t *client, char *peerbuf, size_t len) {
2498         if (client->peeraddr_valid)
2499                 isc_sockaddr_format(&client->peeraddr, peerbuf, len);
2500         else
2501                 snprintf(peerbuf, len, "@%p", client);
2502 }
2503
2504 void
2505 ns_client_logv(ns_client_t *client, isc_logcategory_t *category,
2506            isc_logmodule_t *module, int level, const char *fmt, va_list ap)
2507 {
2508         char msgbuf[2048];
2509         char peerbuf[ISC_SOCKADDR_FORMATSIZE];
2510         const char *name = "";
2511         const char *sep = "";
2512
2513         vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
2514         ns_client_name(client, peerbuf, sizeof(peerbuf));
2515         if (client->view != NULL && strcmp(client->view->name, "_bind") != 0 &&
2516             strcmp(client->view->name, "_default") != 0) {
2517                 name = client->view->name;
2518                 sep = ": view ";
2519         }
2520
2521         isc_log_write(ns_g_lctx, category, module, level,
2522                       "client %s%s%s: %s", peerbuf, sep, name, msgbuf);
2523 }
2524
2525 void
2526 ns_client_log(ns_client_t *client, isc_logcategory_t *category,
2527            isc_logmodule_t *module, int level, const char *fmt, ...)
2528 {
2529         va_list ap;
2530
2531         if (! isc_log_wouldlog(ns_g_lctx, level))
2532                 return;
2533
2534         va_start(ap, fmt);
2535         ns_client_logv(client, category, module, level, fmt, ap);
2536         va_end(ap);
2537 }
2538
2539 void
2540 ns_client_aclmsg(const char *msg, dns_name_t *name, dns_rdatatype_t type,
2541                  dns_rdataclass_t rdclass, char *buf, size_t len)
2542 {
2543         char namebuf[DNS_NAME_FORMATSIZE];
2544         char typebuf[DNS_RDATATYPE_FORMATSIZE];
2545         char classbuf[DNS_RDATACLASS_FORMATSIZE];
2546
2547         dns_name_format(name, namebuf, sizeof(namebuf));
2548         dns_rdatatype_format(type, typebuf, sizeof(typebuf));
2549         dns_rdataclass_format(rdclass, classbuf, sizeof(classbuf));
2550         (void)snprintf(buf, len, "%s '%s/%s/%s'", msg, namebuf, typebuf,
2551                        classbuf);
2552 }
2553
2554 static void
2555 ns_client_dumpmessage(ns_client_t *client, const char *reason) {
2556         isc_buffer_t buffer;
2557         char *buf = NULL;
2558         int len = 1024;
2559         isc_result_t result;
2560
2561         /*
2562          * Note that these are multiline debug messages.  We want a newline
2563          * to appear in the log after each message.
2564          */
2565
2566         do {
2567                 buf = isc_mem_get(client->mctx, len);
2568                 if (buf == NULL)
2569                         break;
2570                 isc_buffer_init(&buffer, buf, len);
2571                 result = dns_message_totext(client->message,
2572                                             &dns_master_style_debug,
2573                                             0, &buffer);
2574                 if (result == ISC_R_NOSPACE) {
2575                         isc_mem_put(client->mctx, buf, len);
2576                         len += 1024;
2577                 } else if (result == ISC_R_SUCCESS)
2578                         ns_client_log(client, NS_LOGCATEGORY_UNMATCHED,
2579                                       NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
2580                                       "%s\n%.*s", reason,
2581                                        (int)isc_buffer_usedlength(&buffer),
2582                                        buf);
2583         } while (result == ISC_R_NOSPACE);
2584
2585         if (buf != NULL)
2586                 isc_mem_put(client->mctx, buf, len);
2587 }
2588
2589 void
2590 ns_client_dumprecursing(FILE *f, ns_clientmgr_t *manager) {
2591         ns_client_t *client;
2592         char namebuf[DNS_NAME_FORMATSIZE];
2593         char peerbuf[ISC_SOCKADDR_FORMATSIZE];
2594         const char *name;
2595         const char *sep;
2596
2597         REQUIRE(VALID_MANAGER(manager));
2598
2599         LOCK(&manager->lock);
2600         client = ISC_LIST_HEAD(manager->recursing);
2601         while (client != NULL) {
2602                 ns_client_name(client, peerbuf, sizeof(peerbuf));
2603                 if (client->view != NULL &&
2604                     strcmp(client->view->name, "_bind") != 0 &&
2605                     strcmp(client->view->name, "_default") != 0) {
2606                         name = client->view->name;
2607                         sep = ": view ";
2608                 } else {
2609                         name = "";
2610                         sep = "";
2611                 }
2612                 dns_name_format(client->query.qname, namebuf, sizeof(namebuf));
2613                 fprintf(f, "; client %s%s%s: '%s' requesttime %d\n",
2614                         peerbuf, sep, name, namebuf, client->requesttime);
2615                 client = ISC_LIST_NEXT(client, link);
2616         }
2617         UNLOCK(&manager->lock);
2618 }
2619
2620 void
2621 ns_client_qnamereplace(ns_client_t *client, dns_name_t *name) {
2622
2623         if (client->manager != NULL)
2624                 LOCK(&client->manager->lock);
2625         if (client->query.restarts > 0) {
2626                 /*
2627                  * client->query.qname was dynamically allocated.
2628                  */
2629                 dns_message_puttempname(client->message,
2630                                         &client->query.qname);
2631         }
2632         client->query.qname = name;
2633         if (client->manager != NULL)
2634                 UNLOCK(&client->manager->lock);
2635 }