/contrib/bind9/bin/named/client.c
C | 2856 lines | 1992 code | 376 blank | 488 comment | 567 complexity | 6ca06a0de244edc47bd898a31b205e8c MD5 | raw file
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1/* 2 * Copyright (C) 2004-2012 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 1.271.10.4 2012/01/31 23:46:39 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/stats.h> 28#include <isc/stdio.h> 29#include <isc/string.h> 30#include <isc/task.h> 31#include <isc/timer.h> 32#include <isc/util.h> 33 34#include <dns/db.h> 35#include <dns/dispatch.h> 36#include <dns/events.h> 37#include <dns/message.h> 38#include <dns/peer.h> 39#include <dns/rcode.h> 40#include <dns/rdata.h> 41#include <dns/rdataclass.h> 42#include <dns/rdatalist.h> 43#include <dns/rdataset.h> 44#include <dns/resolver.h> 45#include <dns/stats.h> 46#include <dns/tsig.h> 47#include <dns/view.h> 48#include <dns/zone.h> 49 50#include <named/interfacemgr.h> 51#include <named/log.h> 52#include <named/notify.h> 53#include <named/os.h> 54#include <named/server.h> 55#include <named/update.h> 56 57/*** 58 *** Client 59 ***/ 60 61/*! \file 62 * Client Routines 63 * 64 * Important note! 65 * 66 * All client state changes, other than that from idle to listening, occur 67 * as a result of events. This guarantees serialization and avoids the 68 * need for locking. 69 * 70 * If a routine is ever created that allows someone other than the client's 71 * task to change the client, then the client will have to be locked. 72 */ 73 74#define NS_CLIENT_TRACE 75#ifdef NS_CLIENT_TRACE 76#define CTRACE(m) ns_client_log(client, \ 77 NS_LOGCATEGORY_CLIENT, \ 78 NS_LOGMODULE_CLIENT, \ 79 ISC_LOG_DEBUG(3), \ 80 "%s", (m)) 81#define MTRACE(m) isc_log_write(ns_g_lctx, \ 82 NS_LOGCATEGORY_GENERAL, \ 83 NS_LOGMODULE_CLIENT, \ 84 ISC_LOG_DEBUG(3), \ 85 "clientmgr @%p: %s", manager, (m)) 86#else 87#define CTRACE(m) ((void)(m)) 88#define MTRACE(m) ((void)(m)) 89#endif 90 91#define TCP_CLIENT(c) (((c)->attributes & NS_CLIENTATTR_TCP) != 0) 92 93#define TCP_BUFFER_SIZE (65535 + 2) 94#define SEND_BUFFER_SIZE 4096 95#define RECV_BUFFER_SIZE 4096 96 97#ifdef ISC_PLATFORM_USETHREADS 98#define NMCTXS 100 99/*%< 100 * Number of 'mctx pools' for clients. (Should this be configurable?) 101 * When enabling threads, we use a pool of memory contexts shared by 102 * client objects, since concurrent access to a shared context would cause 103 * heavy contentions. The above constant is expected to be enough for 104 * completely avoiding contentions among threads for an authoritative-only 105 * server. 106 */ 107#else 108#define NMCTXS 0 109/*%< 110 * If named with built without thread, simply share manager's context. Using 111 * a separate context in this case would simply waste memory. 112 */ 113#endif 114 115/*% nameserver client manager structure */ 116struct ns_clientmgr { 117 /* Unlocked. */ 118 unsigned int magic; 119 isc_mem_t * mctx; 120 isc_taskmgr_t * taskmgr; 121 isc_timermgr_t * timermgr; 122 isc_mutex_t lock; 123 /* Locked by lock. */ 124 isc_boolean_t exiting; 125 client_list_t active; /*%< Active clients */ 126 client_list_t recursing; /*%< Recursing clients */ 127 client_list_t inactive; /*%< To be recycled */ 128#if NMCTXS > 0 129 /*%< mctx pool for clients. */ 130 unsigned int nextmctx; 131 isc_mem_t * mctxpool[NMCTXS]; 132#endif 133}; 134 135#define MANAGER_MAGIC ISC_MAGIC('N', 'S', 'C', 'm') 136#define VALID_MANAGER(m) ISC_MAGIC_VALID(m, MANAGER_MAGIC) 137 138/*! 139 * Client object states. Ordering is significant: higher-numbered 140 * states are generally "more active", meaning that the client can 141 * have more dynamically allocated data, outstanding events, etc. 142 * In the list below, any such properties listed for state N 143 * also apply to any state > N. 144 * 145 * To force the client into a less active state, set client->newstate 146 * to that state and call exit_check(). This will cause any 147 * activities defined for higher-numbered states to be aborted. 148 */ 149 150#define NS_CLIENTSTATE_FREED 0 151/*%< 152 * The client object no longer exists. 153 */ 154 155#define NS_CLIENTSTATE_INACTIVE 1 156/*%< 157 * The client object exists and has a task and timer. 158 * Its "query" struct and sendbuf are initialized. 159 * It is on the client manager's list of inactive clients. 160 * It has a message and OPT, both in the reset state. 161 */ 162 163#define NS_CLIENTSTATE_READY 2 164/*%< 165 * The client object is either a TCP or a UDP one, and 166 * it is associated with a network interface. It is on the 167 * client manager's list of active clients. 168 * 169 * If it is a TCP client object, it has a TCP listener socket 170 * and an outstanding TCP listen request. 171 * 172 * If it is a UDP client object, it has a UDP listener socket 173 * and an outstanding UDP receive request. 174 */ 175 176#define NS_CLIENTSTATE_READING 3 177/*%< 178 * The client object is a TCP client object that has received 179 * a connection. It has a tcpsocket, tcpmsg, TCP quota, and an 180 * outstanding TCP read request. This state is not used for 181 * UDP client objects. 182 */ 183 184#define NS_CLIENTSTATE_WORKING 4 185/*%< 186 * The client object has received a request and is working 187 * on it. It has a view, and it may have any of a non-reset OPT, 188 * recursion quota, and an outstanding write request. 189 */ 190 191#define NS_CLIENTSTATE_MAX 9 192/*%< 193 * Sentinel value used to indicate "no state". When client->newstate 194 * has this value, we are not attempting to exit the current state. 195 * Must be greater than any valid state. 196 */ 197 198/* 199 * Enable ns_client_dropport() by default. 200 */ 201#ifndef NS_CLIENT_DROPPORT 202#define NS_CLIENT_DROPPORT 1 203#endif 204 205unsigned int ns_client_requests; 206 207static void client_read(ns_client_t *client); 208static void client_accept(ns_client_t *client); 209static void client_udprecv(ns_client_t *client); 210static void clientmgr_destroy(ns_clientmgr_t *manager); 211static isc_boolean_t exit_check(ns_client_t *client); 212static void ns_client_endrequest(ns_client_t *client); 213static void ns_client_checkactive(ns_client_t *client); 214static void client_start(isc_task_t *task, isc_event_t *event); 215static void client_request(isc_task_t *task, isc_event_t *event); 216static void ns_client_dumpmessage(ns_client_t *client, const char *reason); 217 218void 219ns_client_recursing(ns_client_t *client) { 220 REQUIRE(NS_CLIENT_VALID(client)); 221 222 LOCK(&client->manager->lock); 223 ISC_LIST_UNLINK(*client->list, client, link); 224 ISC_LIST_APPEND(client->manager->recursing, client, link); 225 client->list = &client->manager->recursing; 226 UNLOCK(&client->manager->lock); 227} 228 229void 230ns_client_killoldestquery(ns_client_t *client) { 231 ns_client_t *oldest; 232 REQUIRE(NS_CLIENT_VALID(client)); 233 234 LOCK(&client->manager->lock); 235 oldest = ISC_LIST_HEAD(client->manager->recursing); 236 if (oldest != NULL) { 237 ns_query_cancel(oldest); 238 ISC_LIST_UNLINK(*oldest->list, oldest, link); 239 ISC_LIST_APPEND(client->manager->active, oldest, link); 240 oldest->list = &client->manager->active; 241 } 242 UNLOCK(&client->manager->lock); 243} 244 245void 246ns_client_settimeout(ns_client_t *client, unsigned int seconds) { 247 isc_result_t result; 248 isc_interval_t interval; 249 250 isc_interval_set(&interval, seconds, 0); 251 result = isc_timer_reset(client->timer, isc_timertype_once, NULL, 252 &interval, ISC_FALSE); 253 client->timerset = ISC_TRUE; 254 if (result != ISC_R_SUCCESS) { 255 ns_client_log(client, NS_LOGCATEGORY_CLIENT, 256 NS_LOGMODULE_CLIENT, ISC_LOG_ERROR, 257 "setting timeout: %s", 258 isc_result_totext(result)); 259 /* Continue anyway. */ 260 } 261} 262 263/*% 264 * Check for a deactivation or shutdown request and take appropriate 265 * action. Returns ISC_TRUE if either is in progress; in this case 266 * the caller must no longer use the client object as it may have been 267 * freed. 268 */ 269static isc_boolean_t 270exit_check(ns_client_t *client) { 271 ns_clientmgr_t *locked_manager = NULL; 272 ns_clientmgr_t *destroy_manager = NULL; 273 274 REQUIRE(NS_CLIENT_VALID(client)); 275 276 if (client->state <= client->newstate) 277 return (ISC_FALSE); /* Business as usual. */ 278 279 INSIST(client->newstate < NS_CLIENTSTATE_WORKING); 280 281 /* 282 * We need to detach from the view early when shutting down 283 * the server to break the following vicious circle: 284 * 285 * - The resolver will not shut down until the view refcount is zero 286 * - The view refcount does not go to zero until all clients detach 287 * - The client does not detach from the view until references is zero 288 * - references does not go to zero until the resolver has shut down 289 * 290 * Keep the view attached until any outstanding updates complete. 291 */ 292 if (client->nupdates == 0 && 293 client->newstate == NS_CLIENTSTATE_FREED && client->view != NULL) 294 dns_view_detach(&client->view); 295 296 if (client->state == NS_CLIENTSTATE_WORKING) { 297 INSIST(client->newstate <= NS_CLIENTSTATE_READING); 298 /* 299 * Let the update processing complete. 300 */ 301 if (client->nupdates > 0) 302 return (ISC_TRUE); 303 /* 304 * We are trying to abort request processing. 305 */ 306 if (client->nsends > 0) { 307 isc_socket_t *socket; 308 if (TCP_CLIENT(client)) 309 socket = client->tcpsocket; 310 else 311 socket = client->udpsocket; 312 isc_socket_cancel(socket, client->task, 313 ISC_SOCKCANCEL_SEND); 314 } 315 316 if (! (client->nsends == 0 && client->nrecvs == 0 && 317 client->references == 0)) 318 { 319 /* 320 * Still waiting for I/O cancel completion. 321 * or lingering references. 322 */ 323 return (ISC_TRUE); 324 } 325 /* 326 * I/O cancel is complete. Burn down all state 327 * related to the current request. Ensure that 328 * the client is on the active list and not the 329 * recursing list. 330 */ 331 LOCK(&client->manager->lock); 332 if (client->list == &client->manager->recursing) { 333 ISC_LIST_UNLINK(*client->list, client, link); 334 ISC_LIST_APPEND(client->manager->active, client, link); 335 client->list = &client->manager->active; 336 } 337 UNLOCK(&client->manager->lock); 338 ns_client_endrequest(client); 339 340 client->state = NS_CLIENTSTATE_READING; 341 INSIST(client->recursionquota == NULL); 342 if (NS_CLIENTSTATE_READING == client->newstate) { 343 client_read(client); 344 client->newstate = NS_CLIENTSTATE_MAX; 345 return (ISC_TRUE); /* We're done. */ 346 } 347 } 348 349 if (client->state == NS_CLIENTSTATE_READING) { 350 /* 351 * We are trying to abort the current TCP connection, 352 * if any. 353 */ 354 INSIST(client->recursionquota == NULL); 355 INSIST(client->newstate <= NS_CLIENTSTATE_READY); 356 if (client->nreads > 0) 357 dns_tcpmsg_cancelread(&client->tcpmsg); 358 if (! client->nreads == 0) { 359 /* Still waiting for read cancel completion. */ 360 return (ISC_TRUE); 361 } 362 363 if (client->tcpmsg_valid) { 364 dns_tcpmsg_invalidate(&client->tcpmsg); 365 client->tcpmsg_valid = ISC_FALSE; 366 } 367 if (client->tcpsocket != NULL) { 368 CTRACE("closetcp"); 369 isc_socket_detach(&client->tcpsocket); 370 } 371 372 if (client->tcpquota != NULL) 373 isc_quota_detach(&client->tcpquota); 374 375 if (client->timerset) { 376 (void)isc_timer_reset(client->timer, 377 isc_timertype_inactive, 378 NULL, NULL, ISC_TRUE); 379 client->timerset = ISC_FALSE; 380 } 381 382 client->peeraddr_valid = ISC_FALSE; 383 384 client->state = NS_CLIENTSTATE_READY; 385 INSIST(client->recursionquota == NULL); 386 387 /* 388 * Now the client is ready to accept a new TCP connection 389 * or UDP request, but we may have enough clients doing 390 * that already. Check whether this client needs to remain 391 * active and force it to go inactive if not. 392 */ 393 ns_client_checkactive(client); 394 395 if (NS_CLIENTSTATE_READY == client->newstate) { 396 if (TCP_CLIENT(client)) { 397 client_accept(client); 398 } else 399 client_udprecv(client); 400 client->newstate = NS_CLIENTSTATE_MAX; 401 return (ISC_TRUE); 402 } 403 } 404 405 if (client->state == NS_CLIENTSTATE_READY) { 406 INSIST(client->newstate <= NS_CLIENTSTATE_INACTIVE); 407 /* 408 * We are trying to enter the inactive state. 409 */ 410 if (client->naccepts > 0) 411 isc_socket_cancel(client->tcplistener, client->task, 412 ISC_SOCKCANCEL_ACCEPT); 413 414 if (! (client->naccepts == 0)) { 415 /* Still waiting for accept cancel completion. */ 416 return (ISC_TRUE); 417 } 418 /* Accept cancel is complete. */ 419 420 if (client->nrecvs > 0) 421 isc_socket_cancel(client->udpsocket, client->task, 422 ISC_SOCKCANCEL_RECV); 423 if (! (client->nrecvs == 0)) { 424 /* Still waiting for recv cancel completion. */ 425 return (ISC_TRUE); 426 } 427 /* Recv cancel is complete. */ 428 429 if (client->nctls > 0) { 430 /* Still waiting for control event to be delivered */ 431 return (ISC_TRUE); 432 } 433 434 /* Deactivate the client. */ 435 if (client->interface) 436 ns_interface_detach(&client->interface); 437 438 INSIST(client->naccepts == 0); 439 INSIST(client->recursionquota == NULL); 440 if (client->tcplistener != NULL) 441 isc_socket_detach(&client->tcplistener); 442 443 if (client->udpsocket != NULL) 444 isc_socket_detach(&client->udpsocket); 445 446 if (client->dispatch != NULL) 447 dns_dispatch_detach(&client->dispatch); 448 449 client->attributes = 0; 450 client->mortal = ISC_FALSE; 451 452 LOCK(&client->manager->lock); 453 /* 454 * Put the client on the inactive list. If we are aiming for 455 * the "freed" state, it will be removed from the inactive 456 * list shortly, and we need to keep the manager locked until 457 * that has been done, lest the manager decide to reactivate 458 * the dying client inbetween. 459 */ 460 locked_manager = client->manager; 461 ISC_LIST_UNLINK(*client->list, client, link); 462 ISC_LIST_APPEND(client->manager->inactive, client, link); 463 client->list = &client->manager->inactive; 464 client->state = NS_CLIENTSTATE_INACTIVE; 465 INSIST(client->recursionquota == NULL); 466 467 if (client->state == client->newstate) { 468 client->newstate = NS_CLIENTSTATE_MAX; 469 if (client->needshutdown) 470 isc_task_shutdown(client->task); 471 goto unlock; 472 } 473 } 474 475 if (client->state == NS_CLIENTSTATE_INACTIVE) { 476 INSIST(client->newstate == NS_CLIENTSTATE_FREED); 477 /* 478 * We are trying to free the client. 479 * 480 * When "shuttingdown" is true, either the task has received 481 * its shutdown event or no shutdown event has ever been 482 * set up. Thus, we have no outstanding shutdown 483 * event at this point. 484 */ 485 REQUIRE(client->state == NS_CLIENTSTATE_INACTIVE); 486 487 INSIST(client->recursionquota == NULL); 488 489 ns_query_free(client); 490 isc_mem_put(client->mctx, client->recvbuf, RECV_BUFFER_SIZE); 491 isc_event_free((isc_event_t **)&client->sendevent); 492 isc_event_free((isc_event_t **)&client->recvevent); 493 isc_timer_detach(&client->timer); 494 495 if (client->tcpbuf != NULL) 496 isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE); 497 if (client->opt != NULL) { 498 INSIST(dns_rdataset_isassociated(client->opt)); 499 dns_rdataset_disassociate(client->opt); 500 dns_message_puttemprdataset(client->message, &client->opt); 501 } 502 dns_message_destroy(&client->message); 503 if (client->manager != NULL) { 504 ns_clientmgr_t *manager = client->manager; 505 if (locked_manager == NULL) { 506 LOCK(&manager->lock); 507 locked_manager = manager; 508 } 509 ISC_LIST_UNLINK(*client->list, client, link); 510 client->list = NULL; 511 if (manager->exiting && 512 ISC_LIST_EMPTY(manager->active) && 513 ISC_LIST_EMPTY(manager->inactive) && 514 ISC_LIST_EMPTY(manager->recursing)) 515 destroy_manager = manager; 516 } 517 /* 518 * Detaching the task must be done after unlinking from 519 * the manager's lists because the manager accesses 520 * client->task. 521 */ 522 if (client->task != NULL) 523 isc_task_detach(&client->task); 524 525 CTRACE("free"); 526 client->magic = 0; 527 /* 528 * Check that there are no other external references to 529 * the memory context. 530 */ 531 if (ns_g_clienttest && isc_mem_references(client->mctx) != 1) { 532 isc_mem_stats(client->mctx, stderr); 533 INSIST(0); 534 } 535 isc_mem_putanddetach(&client->mctx, client, sizeof(*client)); 536 537 goto unlock; 538 } 539 540 unlock: 541 if (locked_manager != NULL) { 542 UNLOCK(&locked_manager->lock); 543 locked_manager = NULL; 544 } 545 546 /* 547 * Only now is it safe to destroy the client manager (if needed), 548 * because we have accessed its lock for the last time. 549 */ 550 if (destroy_manager != NULL) 551 clientmgr_destroy(destroy_manager); 552 553 return (ISC_TRUE); 554} 555 556/*% 557 * The client's task has received the client's control event 558 * as part of the startup process. 559 */ 560static void 561client_start(isc_task_t *task, isc_event_t *event) { 562 ns_client_t *client = (ns_client_t *) event->ev_arg; 563 564 INSIST(task == client->task); 565 566 UNUSED(task); 567 568 INSIST(client->nctls == 1); 569 client->nctls--; 570 571 if (exit_check(client)) 572 return; 573 574 if (TCP_CLIENT(client)) { 575 client_accept(client); 576 } else { 577 client_udprecv(client); 578 } 579} 580 581 582/*% 583 * The client's task has received a shutdown event. 584 */ 585static void 586client_shutdown(isc_task_t *task, isc_event_t *event) { 587 ns_client_t *client; 588 589 REQUIRE(event != NULL); 590 REQUIRE(event->ev_type == ISC_TASKEVENT_SHUTDOWN); 591 client = event->ev_arg; 592 REQUIRE(NS_CLIENT_VALID(client)); 593 REQUIRE(task == client->task); 594 595 UNUSED(task); 596 597 CTRACE("shutdown"); 598 599 isc_event_free(&event); 600 601 if (client->shutdown != NULL) { 602 (client->shutdown)(client->shutdown_arg, ISC_R_SHUTTINGDOWN); 603 client->shutdown = NULL; 604 client->shutdown_arg = NULL; 605 } 606 607 client->newstate = NS_CLIENTSTATE_FREED; 608 client->needshutdown = ISC_FALSE; 609 (void)exit_check(client); 610} 611 612static void 613ns_client_endrequest(ns_client_t *client) { 614 INSIST(client->naccepts == 0); 615 INSIST(client->nreads == 0); 616 INSIST(client->nsends == 0); 617 INSIST(client->nrecvs == 0); 618 INSIST(client->nupdates == 0); 619 INSIST(client->state == NS_CLIENTSTATE_WORKING); 620 621 CTRACE("endrequest"); 622 623 if (client->next != NULL) { 624 (client->next)(client); 625 client->next = NULL; 626 } 627 628 if (client->view != NULL) 629 dns_view_detach(&client->view); 630 if (client->opt != NULL) { 631 INSIST(dns_rdataset_isassociated(client->opt)); 632 dns_rdataset_disassociate(client->opt); 633 dns_message_puttemprdataset(client->message, &client->opt); 634 } 635 636 client->signer = NULL; 637 client->udpsize = 512; 638 client->extflags = 0; 639 client->ednsversion = -1; 640 dns_message_reset(client->message, DNS_MESSAGE_INTENTPARSE); 641 642 if (client->recursionquota != NULL) 643 isc_quota_detach(&client->recursionquota); 644 645 /* 646 * Clear all client attributes that are specific to 647 * the request; that's all except the TCP flag. 648 */ 649 client->attributes &= NS_CLIENTATTR_TCP; 650} 651 652static void 653ns_client_checkactive(ns_client_t *client) { 654 if (client->mortal) { 655 /* 656 * This client object should normally go inactive 657 * at this point, but if we have fewer active client 658 * objects than desired due to earlier quota exhaustion, 659 * keep it active to make up for the shortage. 660 */ 661 isc_boolean_t need_another_client = ISC_FALSE; 662 if (TCP_CLIENT(client) && !ns_g_clienttest) { 663 LOCK(&client->interface->lock); 664 if (client->interface->ntcpcurrent < 665 client->interface->ntcptarget) 666 need_another_client = ISC_TRUE; 667 UNLOCK(&client->interface->lock); 668 } else { 669 /* 670 * The UDP client quota is enforced by making 671 * requests fail rather than by not listening 672 * for new ones. Therefore, there is always a 673 * full set of UDP clients listening. 674 */ 675 } 676 if (! need_another_client) { 677 /* 678 * We don't need this client object. Recycle it. 679 */ 680 if (client->newstate >= NS_CLIENTSTATE_INACTIVE) 681 client->newstate = NS_CLIENTSTATE_INACTIVE; 682 } 683 } 684} 685 686void 687ns_client_next(ns_client_t *client, isc_result_t result) { 688 int newstate; 689 690 REQUIRE(NS_CLIENT_VALID(client)); 691 REQUIRE(client->state == NS_CLIENTSTATE_WORKING || 692 client->state == NS_CLIENTSTATE_READING); 693 694 CTRACE("next"); 695 696 if (result != ISC_R_SUCCESS) 697 ns_client_log(client, DNS_LOGCATEGORY_SECURITY, 698 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), 699 "request failed: %s", isc_result_totext(result)); 700 701 /* 702 * An error processing a TCP request may have left 703 * the connection out of sync. To be safe, we always 704 * sever the connection when result != ISC_R_SUCCESS. 705 */ 706 if (result == ISC_R_SUCCESS && TCP_CLIENT(client)) 707 newstate = NS_CLIENTSTATE_READING; 708 else 709 newstate = NS_CLIENTSTATE_READY; 710 711 if (client->newstate > newstate) 712 client->newstate = newstate; 713 (void)exit_check(client); 714} 715 716 717static void 718client_senddone(isc_task_t *task, isc_event_t *event) { 719 ns_client_t *client; 720 isc_socketevent_t *sevent = (isc_socketevent_t *) event; 721 722 REQUIRE(sevent != NULL); 723 REQUIRE(sevent->ev_type == ISC_SOCKEVENT_SENDDONE); 724 client = sevent->ev_arg; 725 REQUIRE(NS_CLIENT_VALID(client)); 726 REQUIRE(task == client->task); 727 REQUIRE(sevent == client->sendevent); 728 729 UNUSED(task); 730 731 CTRACE("senddone"); 732 733 if (sevent->result != ISC_R_SUCCESS) 734 ns_client_log(client, NS_LOGCATEGORY_CLIENT, 735 NS_LOGMODULE_CLIENT, ISC_LOG_WARNING, 736 "error sending response: %s", 737 isc_result_totext(sevent->result)); 738 739 INSIST(client->nsends > 0); 740 client->nsends--; 741 742 if (client->tcpbuf != NULL) { 743 INSIST(TCP_CLIENT(client)); 744 isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE); 745 client->tcpbuf = NULL; 746 } 747 748 if (exit_check(client)) 749 return; 750 751 ns_client_next(client, ISC_R_SUCCESS); 752} 753 754/*% 755 * We only want to fail with ISC_R_NOSPACE when called from 756 * ns_client_sendraw() and not when called from ns_client_send(), 757 * tcpbuffer is NULL when called from ns_client_sendraw() and 758 * length != 0. tcpbuffer != NULL when called from ns_client_send() 759 * and length == 0. 760 */ 761 762static isc_result_t 763client_allocsendbuf(ns_client_t *client, isc_buffer_t *buffer, 764 isc_buffer_t *tcpbuffer, isc_uint32_t length, 765 unsigned char *sendbuf, unsigned char **datap) 766{ 767 unsigned char *data; 768 isc_uint32_t bufsize; 769 isc_result_t result; 770 771 INSIST(datap != NULL); 772 INSIST((tcpbuffer == NULL && length != 0) || 773 (tcpbuffer != NULL && length == 0)); 774 775 if (TCP_CLIENT(client)) { 776 INSIST(client->tcpbuf == NULL); 777 if (length + 2 > TCP_BUFFER_SIZE) { 778 result = ISC_R_NOSPACE; 779 goto done; 780 } 781 client->tcpbuf = isc_mem_get(client->mctx, TCP_BUFFER_SIZE); 782 if (client->tcpbuf == NULL) { 783 result = ISC_R_NOMEMORY; 784 goto done; 785 } 786 data = client->tcpbuf; 787 if (tcpbuffer != NULL) { 788 isc_buffer_init(tcpbuffer, data, TCP_BUFFER_SIZE); 789 isc_buffer_init(buffer, data + 2, TCP_BUFFER_SIZE - 2); 790 } else { 791 isc_buffer_init(buffer, data, TCP_BUFFER_SIZE); 792 INSIST(length <= 0xffff); 793 isc_buffer_putuint16(buffer, (isc_uint16_t)length); 794 } 795 } else { 796 data = sendbuf; 797 if (client->udpsize < SEND_BUFFER_SIZE) 798 bufsize = client->udpsize; 799 else 800 bufsize = SEND_BUFFER_SIZE; 801 if (length > bufsize) { 802 result = ISC_R_NOSPACE; 803 goto done; 804 } 805 isc_buffer_init(buffer, data, bufsize); 806 } 807 *datap = data; 808 result = ISC_R_SUCCESS; 809 810 done: 811 return (result); 812} 813 814static isc_result_t 815client_sendpkg(ns_client_t *client, isc_buffer_t *buffer) { 816 struct in6_pktinfo *pktinfo; 817 isc_result_t result; 818 isc_region_t r; 819 isc_sockaddr_t *address; 820 isc_socket_t *socket; 821 isc_netaddr_t netaddr; 822 int match; 823 unsigned int sockflags = ISC_SOCKFLAG_IMMEDIATE; 824 825 if (TCP_CLIENT(client)) { 826 socket = client->tcpsocket; 827 address = NULL; 828 } else { 829 socket = client->udpsocket; 830 address = &client->peeraddr; 831 832 isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr); 833 if (ns_g_server->blackholeacl != NULL && 834 dns_acl_match(&netaddr, NULL, 835 ns_g_server->blackholeacl, 836 &ns_g_server->aclenv, 837 &match, NULL) == ISC_R_SUCCESS && 838 match > 0) 839 return (DNS_R_BLACKHOLED); 840 sockflags |= ISC_SOCKFLAG_NORETRY; 841 } 842 843 if ((client->attributes & NS_CLIENTATTR_PKTINFO) != 0 && 844 (client->attributes & NS_CLIENTATTR_MULTICAST) == 0) 845 pktinfo = &client->pktinfo; 846 else 847 pktinfo = NULL; 848 849 isc_buffer_usedregion(buffer, &r); 850 851 CTRACE("sendto"); 852 853 result = isc_socket_sendto2(socket, &r, client->task, 854 address, pktinfo, 855 client->sendevent, sockflags); 856 if (result == ISC_R_SUCCESS || result == ISC_R_INPROGRESS) { 857 client->nsends++; 858 if (result == ISC_R_SUCCESS) 859 client_senddone(client->task, 860 (isc_event_t *)client->sendevent); 861 result = ISC_R_SUCCESS; 862 } 863 return (result); 864} 865 866void 867ns_client_sendraw(ns_client_t *client, dns_message_t *message) { 868 isc_result_t result; 869 unsigned char *data; 870 isc_buffer_t buffer; 871 isc_region_t r; 872 isc_region_t *mr; 873 unsigned char sendbuf[SEND_BUFFER_SIZE]; 874 875 REQUIRE(NS_CLIENT_VALID(client)); 876 877 CTRACE("sendraw"); 878 879 mr = dns_message_getrawmessage(message); 880 if (mr == NULL) { 881 result = ISC_R_UNEXPECTEDEND; 882 goto done; 883 } 884 885 result = client_allocsendbuf(client, &buffer, NULL, mr->length, 886 sendbuf, &data); 887 if (result != ISC_R_SUCCESS) 888 goto done; 889 890 /* 891 * Copy message to buffer and fixup id. 892 */ 893 isc_buffer_availableregion(&buffer, &r); 894 result = isc_buffer_copyregion(&buffer, mr); 895 if (result != ISC_R_SUCCESS) 896 goto done; 897 r.base[0] = (client->message->id >> 8) & 0xff; 898 r.base[1] = client->message->id & 0xff; 899 900 result = client_sendpkg(client, &buffer); 901 if (result == ISC_R_SUCCESS) 902 return; 903 904 done: 905 if (client->tcpbuf != NULL) { 906 isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE); 907 client->tcpbuf = NULL; 908 } 909 ns_client_next(client, result); 910} 911 912void 913ns_client_send(ns_client_t *client) { 914 isc_result_t result; 915 unsigned char *data; 916 isc_buffer_t buffer; 917 isc_buffer_t tcpbuffer; 918 isc_region_t r; 919 dns_compress_t cctx; 920 isc_boolean_t cleanup_cctx = ISC_FALSE; 921 unsigned char sendbuf[SEND_BUFFER_SIZE]; 922 unsigned int render_opts; 923 unsigned int preferred_glue; 924 isc_boolean_t opt_included = ISC_FALSE; 925 926 REQUIRE(NS_CLIENT_VALID(client)); 927 928 CTRACE("send"); 929 930 if ((client->attributes & NS_CLIENTATTR_RA) != 0) 931 client->message->flags |= DNS_MESSAGEFLAG_RA; 932 933 if ((client->attributes & NS_CLIENTATTR_WANTDNSSEC) != 0) 934 render_opts = 0; 935 else 936 render_opts = DNS_MESSAGERENDER_OMITDNSSEC; 937 938 preferred_glue = 0; 939 if (client->view != NULL) { 940 if (client->view->preferred_glue == dns_rdatatype_a) 941 preferred_glue = DNS_MESSAGERENDER_PREFER_A; 942 else if (client->view->preferred_glue == dns_rdatatype_aaaa) 943 preferred_glue = DNS_MESSAGERENDER_PREFER_AAAA; 944 } 945 946#ifdef ALLOW_FILTER_AAAA_ON_V4 947 /* 948 * filter-aaaa-on-v4 yes or break-dnssec option to suppress 949 * AAAA records 950 * We already know that request came via IPv4, 951 * that we have both AAAA and A records, 952 * and that we either have no signatures that the client wants 953 * or we are supposed to break DNSSEC. 954 * 955 * Override preferred glue if necessary. 956 */ 957 if ((client->attributes & NS_CLIENTATTR_FILTER_AAAA) != 0) { 958 render_opts |= DNS_MESSAGERENDER_FILTER_AAAA; 959 if (preferred_glue == DNS_MESSAGERENDER_PREFER_AAAA) 960 preferred_glue = DNS_MESSAGERENDER_PREFER_A; 961 } 962#endif 963 964 /* 965 * XXXRTH The following doesn't deal with TCP buffer resizing. 966 */ 967 result = client_allocsendbuf(client, &buffer, &tcpbuffer, 0, 968 sendbuf, &data); 969 if (result != ISC_R_SUCCESS) 970 goto done; 971 972 result = dns_compress_init(&cctx, -1, client->mctx); 973 if (result != ISC_R_SUCCESS) 974 goto done; 975 cleanup_cctx = ISC_TRUE; 976 977 result = dns_message_renderbegin(client->message, &cctx, &buffer); 978 if (result != ISC_R_SUCCESS) 979 goto done; 980 981 if (client->opt != NULL) { 982 result = dns_message_setopt(client->message, client->opt); 983 opt_included = ISC_TRUE; 984 client->opt = NULL; 985 if (result != ISC_R_SUCCESS) 986 goto done; 987 } 988 result = dns_message_rendersection(client->message, 989 DNS_SECTION_QUESTION, 0); 990 if (result == ISC_R_NOSPACE) { 991 client->message->flags |= DNS_MESSAGEFLAG_TC; 992 goto renderend; 993 } 994 if (result != ISC_R_SUCCESS) 995 goto done; 996 result = dns_message_rendersection(client->message, 997 DNS_SECTION_ANSWER, 998 DNS_MESSAGERENDER_PARTIAL | 999 render_opts); 1000 if (result == ISC_R_NOSPACE) { 1001 client->message->flags |= DNS_MESSAGEFLAG_TC; 1002 goto renderend; 1003 } 1004 if (result != ISC_R_SUCCESS) 1005 goto done; 1006 result = dns_message_rendersection(client->message, 1007 DNS_SECTION_AUTHORITY, 1008 DNS_MESSAGERENDER_PARTIAL | 1009 render_opts); 1010 if (result == ISC_R_NOSPACE) { 1011 client->message->flags |= DNS_MESSAGEFLAG_TC; 1012 goto renderend; 1013 } 1014 if (result != ISC_R_SUCCESS) 1015 goto done; 1016 result = dns_message_rendersection(client->message, 1017 DNS_SECTION_ADDITIONAL, 1018 preferred_glue | render_opts); 1019 if (result != ISC_R_SUCCESS && result != ISC_R_NOSPACE) 1020 goto done; 1021 renderend: 1022 result = dns_message_renderend(client->message); 1023 1024 if (result != ISC_R_SUCCESS) 1025 goto done; 1026 1027 if (cleanup_cctx) { 1028 dns_compress_invalidate(&cctx); 1029 cleanup_cctx = ISC_FALSE; 1030 } 1031 1032 if (TCP_CLIENT(client)) { 1033 isc_buffer_usedregion(&buffer, &r); 1034 isc_buffer_putuint16(&tcpbuffer, (isc_uint16_t) r.length); 1035 isc_buffer_add(&tcpbuffer, r.length); 1036 result = client_sendpkg(client, &tcpbuffer); 1037 } else 1038 result = client_sendpkg(client, &buffer); 1039 1040 /* update statistics (XXXJT: is it okay to access message->xxxkey?) */ 1041 isc_stats_increment(ns_g_server->nsstats, dns_nsstatscounter_response); 1042 if (opt_included) { 1043 isc_stats_increment(ns_g_server->nsstats, 1044 dns_nsstatscounter_edns0out); 1045 } 1046 if (client->message->tsigkey != NULL) { 1047 isc_stats_increment(ns_g_server->nsstats, 1048 dns_nsstatscounter_tsigout); 1049 } 1050 if (client->message->sig0key != NULL) { 1051 isc_stats_increment(ns_g_server->nsstats, 1052 dns_nsstatscounter_sig0out); 1053 } 1054 if ((client->message->flags & DNS_MESSAGEFLAG_TC) != 0) 1055 isc_stats_increment(ns_g_server->nsstats, 1056 dns_nsstatscounter_truncatedresp); 1057 1058 if (result == ISC_R_SUCCESS) 1059 return; 1060 1061 done: 1062 if (client->tcpbuf != NULL) { 1063 isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE); 1064 client->tcpbuf = NULL; 1065 } 1066 1067 if (cleanup_cctx) 1068 dns_compress_invalidate(&cctx); 1069 1070 ns_client_next(client, result); 1071} 1072 1073#if NS_CLIENT_DROPPORT 1074#define DROPPORT_NO 0 1075#define DROPPORT_REQUEST 1 1076#define DROPPORT_RESPONSE 2 1077/*% 1078 * ns_client_dropport determines if certain requests / responses 1079 * should be dropped based on the port number. 1080 * 1081 * Returns: 1082 * \li 0: Don't drop. 1083 * \li 1: Drop request. 1084 * \li 2: Drop (error) response. 1085 */ 1086static int 1087ns_client_dropport(in_port_t port) { 1088 switch (port) { 1089 case 7: /* echo */ 1090 case 13: /* daytime */ 1091 case 19: /* chargen */ 1092 case 37: /* time */ 1093 return (DROPPORT_REQUEST); 1094 case 464: /* kpasswd */ 1095 return (DROPPORT_RESPONSE); 1096 } 1097 return (DROPPORT_NO); 1098} 1099#endif 1100 1101void 1102ns_client_error(ns_client_t *client, isc_result_t result) { 1103 dns_rcode_t rcode; 1104 dns_message_t *message; 1105 1106 REQUIRE(NS_CLIENT_VALID(client)); 1107 1108 CTRACE("error"); 1109 1110 message = client->message; 1111 rcode = dns_result_torcode(result); 1112 1113#if NS_CLIENT_DROPPORT 1114 /* 1115 * Don't send FORMERR to ports on the drop port list. 1116 */ 1117 if (rcode == dns_rcode_formerr && 1118 ns_client_dropport(isc_sockaddr_getport(&client->peeraddr)) != 1119 DROPPORT_NO) { 1120 char buf[64]; 1121 isc_buffer_t b; 1122 1123 isc_buffer_init(&b, buf, sizeof(buf) - 1); 1124 if (dns_rcode_totext(rcode, &b) != ISC_R_SUCCESS) 1125 isc_buffer_putstr(&b, "UNKNOWN RCODE"); 1126 ns_client_log(client, DNS_LOGCATEGORY_SECURITY, 1127 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10), 1128 "dropped error (%.*s) response: suspicious port", 1129 (int)isc_buffer_usedlength(&b), buf); 1130 ns_client_next(client, ISC_R_SUCCESS); 1131 return; 1132 } 1133#endif 1134 1135 /* 1136 * Message may be an in-progress reply that we had trouble 1137 * with, in which case QR will be set. We need to clear QR before 1138 * calling dns_message_reply() to avoid triggering an assertion. 1139 */ 1140 message->flags &= ~DNS_MESSAGEFLAG_QR; 1141 /* 1142 * AA and AD shouldn't be set. 1143 */ 1144 message->flags &= ~(DNS_MESSAGEFLAG_AA | DNS_MESSAGEFLAG_AD); 1145 result = dns_message_reply(message, ISC_TRUE); 1146 if (result != ISC_R_SUCCESS) { 1147 /* 1148 * It could be that we've got a query with a good header, 1149 * but a bad question section, so we try again with 1150 * want_question_section set to ISC_FALSE. 1151 */ 1152 result = dns_message_reply(message, ISC_FALSE); 1153 if (result != ISC_R_SUCCESS) { 1154 ns_client_next(client, result); 1155 return; 1156 } 1157 } 1158 message->rcode = rcode; 1159 1160 /* 1161 * FORMERR loop avoidance: If we sent a FORMERR message 1162 * with the same ID to the same client less than two 1163 * seconds ago, assume that we are in an infinite error 1164 * packet dialog with a server for some protocol whose 1165 * error responses look enough like DNS queries to 1166 * elicit a FORMERR response. Drop a packet to break 1167 * the loop. 1168 */ 1169 if (rcode == dns_rcode_formerr) { 1170 if (isc_sockaddr_equal(&client->peeraddr, 1171 &client->formerrcache.addr) && 1172 message->id == client->formerrcache.id && 1173 client->requesttime - client->formerrcache.time < 2) { 1174 /* Drop packet. */ 1175 ns_client_log(client, NS_LOGCATEGORY_CLIENT, 1176 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1), 1177 "possible error packet loop, " 1178 "FORMERR dropped"); 1179 ns_client_next(client, result); 1180 return; 1181 } 1182 client->formerrcache.addr = client->peeraddr; 1183 client->formerrcache.time = client->requesttime; 1184 client->formerrcache.id = message->id; 1185 } 1186 ns_client_send(client); 1187} 1188 1189static inline isc_result_t 1190client_addopt(ns_client_t *client) { 1191 dns_rdataset_t *rdataset; 1192 dns_rdatalist_t *rdatalist; 1193 dns_rdata_t *rdata; 1194 isc_result_t result; 1195 dns_view_t *view; 1196 dns_resolver_t *resolver; 1197 isc_uint16_t udpsize; 1198 1199 REQUIRE(client->opt == NULL); /* XXXRTH free old. */ 1200 1201 rdatalist = NULL; 1202 result = dns_message_gettemprdatalist(client->message, &rdatalist); 1203 if (result != ISC_R_SUCCESS) 1204 return (result); 1205 rdata = NULL; 1206 result = dns_message_gettemprdata(client->message, &rdata); 1207 if (result != ISC_R_SUCCESS) 1208 return (result); 1209 rdataset = NULL; 1210 result = dns_message_gettemprdataset(client->message, &rdataset); 1211 if (result != ISC_R_SUCCESS) 1212 return (result); 1213 dns_rdataset_init(rdataset); 1214 1215 rdatalist->type = dns_rdatatype_opt; 1216 rdatalist->covers = 0; 1217 1218 /* 1219 * Set the maximum UDP buffer size. 1220 */ 1221 view = client->view; 1222 resolver = (view != NULL) ? view->resolver : NULL; 1223 if (resolver != NULL) 1224 udpsize = dns_resolver_getudpsize(resolver); 1225 else 1226 udpsize = ns_g_udpsize; 1227 rdatalist->rdclass = udpsize; 1228 1229 /* 1230 * Set EXTENDED-RCODE, VERSION and Z to 0. 1231 */ 1232 rdatalist->ttl = (client->extflags & DNS_MESSAGEEXTFLAG_REPLYPRESERVE); 1233 1234 /* Set EDNS options if applicable */ 1235 if (client->attributes & NS_CLIENTATTR_WANTNSID && 1236 (ns_g_server->server_id != NULL || 1237 ns_g_server->server_usehostname)) { 1238 /* 1239 * Space required for NSID data: 1240 * 2 bytes for opt code 1241 * + 2 bytes for NSID length 1242 * + NSID itself 1243 */ 1244 char nsid[BUFSIZ], *nsidp; 1245 isc_buffer_t *buffer = NULL; 1246 1247 if (ns_g_server->server_usehostname) { 1248 isc_result_t result; 1249 result = ns_os_gethostname(nsid, sizeof(nsid)); 1250 if (result != ISC_R_SUCCESS) { 1251 goto no_nsid; 1252 } 1253 nsidp = nsid; 1254 } else 1255 nsidp = ns_g_server->server_id; 1256 1257 rdata->length = strlen(nsidp) + 4; 1258 result = isc_buffer_allocate(client->mctx, &buffer, 1259 rdata->length); 1260 if (result != ISC_R_SUCCESS) 1261 goto no_nsid; 1262 1263 isc_buffer_putuint16(buffer, DNS_OPT_NSID); 1264 isc_buffer_putuint16(buffer, strlen(nsidp)); 1265 isc_buffer_putstr(buffer, nsidp); 1266 rdata->data = buffer->base; 1267 dns_message_takebuffer(client->message, &buffer); 1268 } else { 1269no_nsid: 1270 rdata->data = NULL; 1271 rdata->length = 0; 1272 } 1273 1274 rdata->rdclass = rdatalist->rdclass; 1275 rdata->type = rdatalist->type; 1276 rdata->flags = 0; 1277 1278 ISC_LIST_INIT(rdatalist->rdata); 1279 ISC_LIST_APPEND(rdatalist->rdata, rdata, link); 1280 RUNTIME_CHECK(dns_rdatalist_tordataset(rdatalist, rdataset) 1281 == ISC_R_SUCCESS); 1282 1283 client->opt = rdataset; 1284 1285 return (ISC_R_SUCCESS); 1286} 1287 1288static inline isc_boolean_t 1289allowed(isc_netaddr_t *addr, dns_name_t *signer, dns_acl_t *acl) { 1290 int match; 1291 isc_result_t result; 1292 1293 if (acl == NULL) 1294 return (ISC_TRUE); 1295 result = dns_acl_match(addr, signer, acl, &ns_g_server->aclenv, 1296 &match, NULL); 1297 if (result == ISC_R_SUCCESS && match > 0) 1298 return (ISC_TRUE); 1299 return (ISC_FALSE); 1300} 1301 1302/* 1303 * Callback to see if a non-recursive query coming from 'srcaddr' to 1304 * 'destaddr', with optional key 'mykey' for class 'rdclass' would be 1305 * delivered to 'myview'. 1306 * 1307 * We run this unlocked as both the view list and the interface list 1308 * are updated when the appropriate task has exclusivity. 1309 */ 1310isc_boolean_t 1311ns_client_isself(dns_view_t *myview, dns_tsigkey_t *mykey, 1312 isc_sockaddr_t *srcaddr, isc_sockaddr_t *dstaddr, 1313 dns_rdataclass_t rdclass, void *arg) 1314{ 1315 dns_view_t *view; 1316 dns_tsigkey_t *key = NULL; 1317 dns_name_t *tsig = NULL; 1318 isc_netaddr_t netsrc; 1319 isc_netaddr_t netdst; 1320 1321 UNUSED(arg); 1322 1323 /* 1324 * ns_g_server->interfacemgr is task exclusive locked. 1325 */ 1326 if (ns_g_server->interfacemgr == NULL) 1327 return (ISC_TRUE); 1328 1329 if (!ns_interfacemgr_listeningon(ns_g_server->interfacemgr, dstaddr)) 1330 return (ISC_FALSE); 1331 1332 isc_netaddr_fromsockaddr(&netsrc, srcaddr); 1333 isc_netaddr_fromsockaddr(&netdst, dstaddr); 1334 1335 for (view = ISC_LIST_HEAD(ns_g_server->viewlist); 1336 view != NULL; 1337 view = ISC_LIST_NEXT(view, link)) { 1338 1339 if (view->matchrecursiveonly) 1340 continue; 1341 1342 if (rdclass != view->rdclass) 1343 continue; 1344 1345 if (mykey != NULL) { 1346 isc_boolean_t match; 1347 isc_result_t result; 1348 1349 result = dns_view_gettsig(view, &mykey->name, &key); 1350 if (result != ISC_R_SUCCESS) 1351 continue; 1352 match = dst_key_compare(mykey->key, key->key); 1353 dns_tsigkey_detach(&key); 1354 if (!match) 1355 continue; 1356 tsig = dns_tsigkey_identity(mykey); 1357 } 1358 1359 if (allowed(&netsrc, tsig, view->matchclients) && 1360 allowed(&netdst, tsig, view->matchdestinations)) 1361 break; 1362 } 1363 return (ISC_TF(view == myview)); 1364} 1365 1366/* 1367 * Handle an incoming request event from the socket (UDP case) 1368 * or tcpmsg (TCP case). 1369 */ 1370static void 1371client_request(isc_task_t *task, isc_event_t *event) { 1372 ns_client_t *client; 1373 isc_socketevent_t *sevent; 1374 isc_result_t result; 1375 isc_result_t sigresult = ISC_R_SUCCESS; 1376 isc_buffer_t *buffer; 1377 isc_buffer_t tbuffer; 1378 dns_view_t *view; 1379 dns_rdataset_t *opt; 1380 dns_name_t *signame; 1381 isc_boolean_t ra; /* Recursion available. */ 1382 isc_netaddr_t netaddr; 1383 int match; 1384 dns_messageid_t id; 1385 unsigned int flags; 1386 isc_boolean_t notimp; 1387 dns_rdata_t rdata; 1388 isc_uint16_t optcode; 1389 1390 REQUIRE(event != NULL); 1391 client = event->ev_arg; 1392 REQUIRE(NS_CLIENT_VALID(client)); 1393 REQUIRE(task == client->task); 1394 1395 INSIST(client->recursionquota == NULL); 1396 1397 INSIST(client->state == 1398 TCP_CLIENT(client) ? 1399 NS_CLIENTSTATE_READING : 1400 NS_CLIENTSTATE_READY); 1401 1402 ns_client_requests++; 1403 1404 if (event->ev_type == ISC_SOCKEVENT_RECVDONE) { 1405 INSIST(!TCP_CLIENT(client)); 1406 sevent = (isc_socketevent_t *)event; 1407 REQUIRE(sevent == client->recvevent); 1408 isc_buffer_init(&tbuffer, sevent->region.base, sevent->n); 1409 isc_buffer_add(&tbuffer, sevent->n); 1410 buffer = &tbuffer; 1411 result = sevent->result; 1412 if (result == ISC_R_SUCCESS) { 1413 client->peeraddr = sevent->address; 1414 client->peeraddr_valid = ISC_TRUE; 1415 } 1416 if ((sevent->attributes & ISC_SOCKEVENTATTR_PKTINFO) != 0) { 1417 client->attributes |= NS_CLIENTATTR_PKTINFO; 1418 client->pktinfo = sevent->pktinfo; 1419 } 1420 if ((sevent->attributes & ISC_SOCKEVENTATTR_MULTICAST) != 0) 1421 client->attributes |= NS_CLIENTATTR_MULTICAST; 1422 client->nrecvs--; 1423 } else { 1424 INSIST(TCP_CLIENT(client)); 1425 REQUIRE(event->ev_type == DNS_EVENT_TCPMSG); 1426 REQUIRE(event->ev_sender == &client->tcpmsg); 1427 buffer = &client->tcpmsg.buffer; 1428 result = client->tcpmsg.result; 1429 INSIST(client->nreads == 1); 1430 /* 1431 * client->peeraddr was set when the connection was accepted. 1432 */ 1433 client->nreads--; 1434 } 1435 1436 if (exit_check(client)) 1437 goto cleanup; 1438 client->state = client->newstate = NS_CLIENTSTATE_WORKING; 1439 1440 isc_task_getcurrenttime(task, &client->requesttime); 1441 client->now = client->requesttime; 1442 1443 if (result != ISC_R_SUCCESS) { 1444 if (TCP_CLIENT(client)) { 1445 ns_client_next(client, result); 1446 } else { 1447 if (result != ISC_R_CANCELED) 1448 isc_log_write(ns_g_lctx, NS_LOGCATEGORY_CLIENT, 1449 NS_LOGMODULE_CLIENT, 1450 ISC_LOG_ERROR, 1451 "UDP client handler shutting " 1452 "down due to fatal receive " 1453 "error: %s", 1454 isc_result_totext(result)); 1455 isc_task_shutdown(client->task); 1456 } 1457 goto cleanup; 1458 } 1459 1460 isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr); 1461 1462#if NS_CLIENT_DROPPORT 1463 if (ns_client_dropport(isc_sockaddr_getport(&client->peeraddr)) == 1464 DROPPORT_REQUEST) { 1465 ns_client_log(client, DNS_LOGCATEGORY_SECURITY, 1466 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10), 1467 "dropped request: suspicious port"); 1468 ns_client_next(client, ISC_R_SUCCESS); 1469 goto cleanup; 1470 } 1471#endif 1472 1473 ns_client_log(client, NS_LOGCATEGORY_CLIENT, 1474 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), 1475 "%s request", 1476 TCP_CLIENT(client) ? "TCP" : "UDP"); 1477 1478 /* 1479 * Check the blackhole ACL for UDP only, since TCP is done in 1480 * client_newconn. 1481 */ 1482 if (!TCP_CLIENT(client)) { 1483 1484 if (ns_g_server->blackholeacl != NULL && 1485 dns_acl_match(&netaddr, NULL, ns_g_server->blackholeacl, 1486 &ns_g_server->aclenv, 1487 &match, NULL) == ISC_R_SUCCESS && 1488 match > 0) 1489 { 1490 ns_client_log(client, DNS_LOGCATEGORY_SECURITY, 1491 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10), 1492 "blackholed UDP datagram"); 1493 ns_client_next(client, ISC_R_SUCCESS); 1494 goto cleanup; 1495 } 1496 } 1497 1498 /* 1499 * Silently drop multicast requests for the present. 1500 * XXXMPA revisit this as mDNS spec was published. 1501 */ 1502 if ((client->attributes & NS_CLIENTATTR_MULTICAST) != 0) { 1503 ns_client_log(client, NS_LOGCATEGORY_CLIENT, 1504 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2), 1505 "dropping multicast request"); 1506 ns_client_next(client, DNS_R_REFUSED); 1507 goto cleanup; 1508 } 1509 1510 result = dns_message_peekheader(buffer, &id, &flags); 1511 if (result != ISC_R_SUCCESS) { 1512 /* 1513 * There isn't enough header to determine whether 1514 * this was a request or a response. Drop it. 1515 */ 1516 ns_client_next(client, result); 1517 goto cleanup; 1518 } 1519 1520 /* 1521 * The client object handles requests, not responses. 1522 * If this is a UDP response, forward it to the dispatcher. 1523 * If it's a TCP response, discard it here. 1524 */ 1525 if ((flags & DNS_MESSAGEFLAG_QR) != 0) { 1526 if (TCP_CLIENT(client)) { 1527 CTRACE("unexpected response"); 1528 ns_client_next(client, DNS_R_FORMERR); 1529 goto cleanup; 1530 } else { 1531 dns_dispatch_importrecv(client->dispatch, event); 1532 ns_client_next(client, ISC_R_SUCCESS); 1533 goto cleanup; 1534 } 1535 } 1536 1537 /* 1538 * Update some statistics counters. Don't count responses. 1539 */ 1540 if (isc_sockaddr_pf(&client->peeraddr) == PF_INET) { 1541 isc_stats_increment(ns_g_server->nsstats, 1542 dns_nsstatscounter_requestv4); 1543 } else { 1544 isc_stats_increment(ns_g_server->nsstats, 1545 dns_nsstatscounter_requestv6); 1546 } 1547 if (TCP_CLIENT(client)) 1548 isc_stats_increment(ns_g_server->nsstats, 1549 dns_nsstatscounter_tcp); 1550 1551 /* 1552 * It's a request. Parse it. 1553 */ 1554 result = dns_message_parse(client->message, buffer, 0); 1555 if (result != ISC_R_SUCCESS) { 1556 /* 1557 * Parsing the request failed. Send a response 1558 * (typically FORMERR or SERVFAIL). 1559 */ 1560 ns_client_error(client, result); 1561 goto cleanup; 1562 } 1563 1564 dns_opcodestats_increment(ns_g_server->opcodestats, 1565 client->message->opcode); 1566 switch (client->message->opcode) { 1567 case dns_opcode_query: 1568 case dns_opcode_update: 1569 case dns_opcode_notify: 1570 notimp = ISC_FALSE; 1571 break; 1572 case dns_opcode_iquery: 1573 default: 1574 notimp = ISC_TRUE; 1575 break; 1576 } 1577 1578 client->message->rcode = dns_rcode_noerror; 1579 1580 /* RFC1123 section 6.1.3.2 */ 1581 if ((client->attributes & NS_CLIENTATTR_MULTICAST) != 0) 1582 client->message->flags &= ~DNS_MESSAGEFLAG_RD; 1583 1584 /* 1585 * Deal with EDNS. 1586 */ 1587 opt = dns_message_getopt(client->message); 1588 if (opt != NULL) { 1589 /* 1590 * Set the client's UDP buffer size. 1591 */ 1592 client->udpsize = opt->rdclass; 1593 1594 /* 1595 * If the requested UDP buffer size is less than 512, 1596 * ignore it and use 512. 1597 */ 1598 if (client->udpsize < 512) 1599 client->udpsize = 512; 1600 1601 /* 1602 * Get the flags out of the OPT record. 1603 */ 1604 client->extflags = (isc_uint16_t)(opt->ttl & 0xFFFF); 1605 1606 /* 1607 * Do we understand this version of EDNS? 1608 * 1609 * XXXRTH need library support for this! 1610 */ 1611 client->ednsversion = (opt->ttl & 0x00FF0000) >> 16; 1612 if (client->ednsversion > 0) { 1613 isc_stats_increment(ns_g_server->nsstats, 1614 dns_nsstatscounter_badednsver); 1615 result = client_addopt(client); 1616 if (result == ISC_R_SUCCESS) 1617 result = DNS_R_BADVERS; 1618 ns_client_error(client, result); 1619 goto cleanup; 1620 } 1621 1622 /* Check for NSID request */ 1623 result = dns_rdataset_first(opt); 1624 if (result == ISC_R_SUCCESS) { 1625 dns_rdata_init(&rdata); 1626 dns_rdataset_current(opt, &rdata); 1627 if (rdata.length >= 2) { 1628 isc_buffer_t nsidbuf; 1629 isc_buffer_init(&nsidbuf, 1630 rdata.data, rdata.length); 1631 isc_buffer_add(&nsidbuf, rdata.length); 1632 optcode = isc_buffer_getuint16(&nsidbuf); 1633 if (optcode == DNS_OPT_NSID) 1634 client->attributes |= 1635 NS_CLIENTATTR_WANTNSID; 1636 } 1637 } 1638 1639 isc_stats_increment(ns_g_server->nsstats, 1640 dns_nsstatscounter_edns0in); 1641 1642 /* 1643 * Create an OPT for our reply. 1644 */ 1645 result = client_addopt(client); 1646 if (result != ISC_R_SUCCESS) { 1647 ns_client_error(client, result); 1648 goto cleanup; 1649 } 1650 } 1651 1652 if (client->message->rdclass == 0) { 1653 ns_client_log(client, NS_LOGCATEGORY_CLIENT, 1654 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1), 1655 "message class could not be determined"); 1656 ns_client_dumpmessage(client, 1657 "message class could not be determined"); 1658 ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_FORMERR); 1659 goto cleanup; 1660 } 1661 1662 /* 1663 * Determine the destination address. If the receiving interface is 1664 * bound to a specific address, we simply use it regardless of the 1665 * address family. All IPv4 queries should fall into this case. 1666 * Otherwise, if this is a TCP query, get the address from the 1667 * receiving socket (this needs a system call and can be heavy). 1668 * For IPv6 UDP queries, we get this from the pktinfo structure (if 1669 * supported). 1670 * If all the attempts fail (this can happen due to memory shortage, 1671 * etc), we regard this as an error for safety. 1672 */ 1673 if ((client->interface->flags & NS_INTERFACEFLAG_ANYADDR) == 0) 1674 isc_netaddr_fromsockaddr(&client->destaddr, 1675 &client->interface->addr); 1676 else { 1677 isc_sockaddr_t sockaddr; 1678 result = ISC_R_FAILURE; 1679 1680 if (TCP_CLIENT(client)) 1681 result = isc_socket_getsockname(client->tcpsocket, 1682 &sockaddr); 1683 if (result == ISC_R_SUCCESS) 1684 isc_netaddr_fromsockaddr(&client->destaddr, &sockaddr); 1685 if (result != ISC_R_SUCCESS && 1686 client->interface->addr.type.sa.sa_family == AF_INET6 && 1687 (client->attributes & NS_CLIENTATTR_PKTINFO) != 0) { 1688 /* 1689 * XXXJT technically, we should convert the receiving 1690 * interface ID to a proper scope zone ID. However, 1691 * due to the fact there is no standard API for this, 1692 * we only handle link-local addresses and use the 1693 * interface index as link ID. Despite the assumption, 1694 * it should cover most typical cases. 1695 */ 1696 isc_netaddr_fromin6(&client->destaddr, 1697 &client->pktinfo.ipi6_addr); 1698 if (IN6_IS_ADDR_LINKLOCAL(&client->pktinfo.ipi6_addr)) 1699 isc_netaddr_setzone(&client->destaddr, 1700 client->pktinfo.ipi6_ifindex); 1701 result = ISC_R_SUCCESS; 1702 } 1703 if (result != ISC_R_SUCCESS) { 1704 UNEXPECTED_ERROR(__FILE__, __LINE__, 1705 "failed to get request's " 1706 "destination: %s", 1707 isc_result_totext(result)); 1708 ns_client_next(client, ISC_R_SUCCESS); 1709 goto cleanup; 1710 } 1711 } 1712 1713 /* 1714 * Find a view that matches the client's source address. 1715 */ 1716 for (view = ISC_LIST_HEAD(ns_g_server->viewlist); 1717 view != NULL; 1718 view = ISC_LIST_NEXT(view, link)) { 1719 if (client->message->rdclass == view->rdclass || 1720 client->message->rdclass == dns_rdataclass_any) 1721 { 1722 dns_name_t *tsig = NULL; 1723 1724 sigresult = dns_message_rechecksig(client->message, 1725 view); 1726 if (sigresult == ISC_R_SUCCESS) 1727 tsig = dns_tsigkey_identity(client->message->tsigkey); 1728 1729 if (allowed(&netaddr, tsig, view->matchclients) && 1730 allowed(&client->destaddr, tsig, 1731 view->matchdestinations) && 1732 !((client->message->flags & DNS_MESSAGEFLAG_RD) 1733 == 0 && view->matchrecursiveonly)) 1734 { 1735 dns_view_attach(view, &client->view); 1736 break; 1737 } 1738 } 1739 } 1740 1741 if (view == NULL) { 1742 char classname[DNS_RDATACLASS_FORMATSIZE]; 1743 1744 /* 1745 * Do a dummy TSIG verification attempt so that the 1746 * response will have a TSIG if the query did, as 1747 * required by RFC2845. 1748 */ 1749 isc_buffer_t b; 1750 isc_region_t *r; 1751 1752 dns_message_resetsig(client->message); 1753 1754 r = dns_message_getrawmessage(client->message); 1755 isc_buffer_init(&b, r->base, r->length); 1756 isc_buffer_add(&b, r->length); 1757 (void)dns_tsig_verify(&b, client->message, NULL, NULL); 1758 1759 dns_rdataclass_format(client->message->rdclass, classname, 1760 sizeof(classname)); 1761 ns_client_log(client, NS_LOGCATEGORY_CLIENT, 1762 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1), 1763 "no matching view in class '%s'", classname); 1764 ns_client_dumpmessage(client, "no matching view in class"); 1765 ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_REFUSED); 1766 goto cleanup; 1767 } 1768 1769 ns_client_log(client, NS_LOGCATEGORY_CLIENT, 1770 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(5), 1771 "using view '%s'", view->name); 1772 1773 /* 1774 * Check for a signature. We log bad signatures regardless of 1775 * whether they ultimately cause the request to be rejected or 1776 * not. We do not log the lack of a signature unless we are 1777 * debugging. 1778 */ 1779 client->signer = NULL; 1780 dns_name_init(&client->signername, NULL); 1781 result = dns_message_signer(client->message, &client->signername); 1782 if (result != ISC_R_NOTFOUND) { 1783 signame = NULL; 1784 if (dns_message_gettsig(client->message, &signame) != NULL) { 1785 isc_stats_increment(ns_g_server->nsstats, 1786 dns_nsstatscounter_tsigin); 1787 } else { 1788 isc_stats_increment(ns_g_server->nsstats, 1789 dns_nsstatscounter_sig0in); 1790 } 1791 1792 } 1793 if (result == ISC_R_SUCCESS) { 1794 char namebuf[DNS_NAME_FORMATSIZE]; 1795 dns_name_format(&client->signername, namebuf, sizeof(namebuf)); 1796 ns_client_log(client, DNS_LOGCATEGORY_SECURITY, 1797 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), 1798 "request has valid signature: %s", namebuf); 1799 client->signer = &client->signername; 1800 } else if (result == ISC_R_NOTFOUND) { 1801 ns_client_log(client, DNS_LOGCATEGORY_SECURITY, 1802 NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(…
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