contrib/bind-9.3/bin/named/lwresd.c

   1 /*
   2  * Copyright (C) 2004, 2006  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000-2003  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and 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: lwresd.c,v 1.37.2.2.2.8 2006/02/28 06:32:53 marka Exp $ */
  19
  20 /*
  21  * Main program for the Lightweight Resolver Daemon.
  22  *
  23  * To paraphrase the old saying about X11, "It's not a lightweight deamon
  24  * for resolvers, it's a deamon for lightweight resolvers".
  25  */
  26
  27 #include <config.h>
  28
  29 #include <stdlib.h>
  30 #include <string.h>
  31
  32 #include <isc/list.h>
  33 #include <isc/magic.h>
  34 #include <isc/mem.h>
  35 #include <isc/once.h>
  36 #include <isc/print.h>
  37 #include <isc/socket.h>
  38 #include <isc/task.h>
  39 #include <isc/util.h>
  40
  41 #include <isccfg/namedconf.h>
  42
  43 #include <dns/log.h>
  44 #include <dns/result.h>
  45 #include <dns/view.h>
  46
  47 #include <named/config.h>
  48 #include <named/globals.h>
  49 #include <named/log.h>
  50 #include <named/lwaddr.h>
  51 #include <named/lwresd.h>
  52 #include <named/lwdclient.h>
  53 #include <named/lwsearch.h>
  54 #include <named/server.h>
  55
  56 #define LWRESD_MAGIC            ISC_MAGIC('L', 'W', 'R', 'D')
  57 #define VALID_LWRESD(l)         ISC_MAGIC_VALID(l, LWRESD_MAGIC)
  58
  59 #define LWRESLISTENER_MAGIC     ISC_MAGIC('L', 'W', 'R', 'L')
  60 #define VALID_LWRESLISTENER(l)  ISC_MAGIC_VALID(l, LWRESLISTENER_MAGIC)
  61
  62 /*
  63  * The total number of clients we can handle will be NTASKS * NRECVS.
  64  */
  65 #define NTASKS          2       /* tasks to create to handle lwres queries */
  66 #define NRECVS          2       /* max clients per task */
  67
  68 typedef ISC_LIST(ns_lwreslistener_t) ns_lwreslistenerlist_t;
  69
  70 static ns_lwreslistenerlist_t listeners;
  71 static isc_mutex_t listeners_lock;
  72 static isc_once_t once = ISC_ONCE_INIT;
  73
  74
  75 static void
  76 initialize_mutex(void) {
  77         RUNTIME_CHECK(isc_mutex_init(&listeners_lock) == ISC_R_SUCCESS);
  78 }
  79
  80
  81 /*
  82  * Wrappers around our memory management stuff, for the lwres functions.
  83  */
  84 void *
  85 ns__lwresd_memalloc(void *arg, size_t size) {
  86         return (isc_mem_get(arg, size));
  87 }
  88
  89 void
  90 ns__lwresd_memfree(void *arg, void *mem, size_t size) {
  91         isc_mem_put(arg, mem, size);
  92 }
  93
  94
  95 #define CHECK(op)                                               \
  96         do { result = (op);                                     \
  97                 if (result != ISC_R_SUCCESS) goto cleanup;      \
  98         } while (0)
  99
 100 static isc_result_t
 101 buffer_putstr(isc_buffer_t *b, const char *s) {
 102         unsigned int len = strlen(s);
 103         if (isc_buffer_availablelength(b) <= len)
 104                 return (ISC_R_NOSPACE);
 105         isc_buffer_putmem(b, (const unsigned char *)s, len);
 106         return (ISC_R_SUCCESS);
 107 }
 108
 109 /*
 110  * Convert a resolv.conf file into a config structure.
 111  */
 112 isc_result_t
 113 ns_lwresd_parseeresolvconf(isc_mem_t *mctx, cfg_parser_t *pctx,
 114                            cfg_obj_t **configp)
 115 {
 116         char text[4096];
 117         char str[16];
 118         isc_buffer_t b;
 119         lwres_context_t *lwctx = NULL;
 120         lwres_conf_t *lwc = NULL;
 121         isc_sockaddr_t sa;
 122         isc_netaddr_t na;
 123         int i;
 124         isc_result_t result;
 125         lwres_result_t lwresult;
 126
 127         lwctx = NULL;
 128         lwresult = lwres_context_create(&lwctx, mctx, ns__lwresd_memalloc,
 129                                         ns__lwresd_memfree,
 130                                         LWRES_CONTEXT_SERVERMODE);
 131         if (lwresult != LWRES_R_SUCCESS) {
 132                 result = ISC_R_NOMEMORY;
 133                 goto cleanup;
 134         }
 135
 136         lwresult = lwres_conf_parse(lwctx, lwresd_g_resolvconffile);
 137         if (lwresult != LWRES_R_SUCCESS) {
 138                 result = DNS_R_SYNTAX;
 139                 goto cleanup;
 140         }
 141
 142         lwc = lwres_conf_get(lwctx);
 143         INSIST(lwc != NULL);
 144
 145         isc_buffer_init(&b, text, sizeof(text));
 146
 147         CHECK(buffer_putstr(&b, "options {\n"));
 148
 149         /*
 150          * Build the list of forwarders.
 151          */
 152         if (lwc->nsnext > 0) {
 153                 CHECK(buffer_putstr(&b, "\tforwarders {\n"));
 154
 155                 for (i = 0; i < lwc->nsnext; i++) {
 156                         CHECK(lwaddr_sockaddr_fromlwresaddr(
 157                                                         &sa,
 158                                                         &lwc->nameservers[i],
 159                                                         ns_g_port));
 160                         isc_netaddr_fromsockaddr(&na, &sa);
 161                         CHECK(buffer_putstr(&b, "\t\t"));
 162                         CHECK(isc_netaddr_totext(&na, &b));
 163                         CHECK(buffer_putstr(&b, ";\n"));
 164                 }
 165                 CHECK(buffer_putstr(&b, "\t};\n"));
 166         }
 167
 168         /*
 169          * Build the sortlist
 170          */
 171         if (lwc->sortlistnxt > 0) {
 172                 CHECK(buffer_putstr(&b, "\tsortlist {\n"));
 173                 CHECK(buffer_putstr(&b, "\t\t{\n"));
 174                 CHECK(buffer_putstr(&b, "\t\t\tany;\n"));
 175                 CHECK(buffer_putstr(&b, "\t\t\t{\n"));
 176                 for (i = 0; i < lwc->sortlistnxt; i++) {
 177                         lwres_addr_t *lwaddr = &lwc->sortlist[i].addr;
 178                         lwres_addr_t *lwmask = &lwc->sortlist[i].mask;
 179                         unsigned int mask;
 180
 181                         CHECK(lwaddr_sockaddr_fromlwresaddr(&sa, lwmask, 0));
 182                         isc_netaddr_fromsockaddr(&na, &sa);
 183                         result = isc_netaddr_masktoprefixlen(&na, &mask);
 184                         if (result != ISC_R_SUCCESS) {
 185                                 char addrtext[ISC_NETADDR_FORMATSIZE];
 186                                 isc_netaddr_format(&na, addrtext,
 187                                                    sizeof(addrtext));
 188                                 isc_log_write(ns_g_lctx,
 189                                               NS_LOGCATEGORY_GENERAL,
 190                                               NS_LOGMODULE_LWRESD,
 191                                               ISC_LOG_ERROR,
 192                                               "processing sortlist: '%s' is "
 193                                               "not a valid netmask",
 194                                               addrtext);
 195                                 goto cleanup;
 196                         }
 197
 198                         CHECK(lwaddr_sockaddr_fromlwresaddr(&sa, lwaddr, 0));
 199                         isc_netaddr_fromsockaddr(&na, &sa);
 200
 201                         CHECK(buffer_putstr(&b, "\t\t\t\t"));
 202                         CHECK(isc_netaddr_totext(&na, &b));
 203                         snprintf(str, sizeof(str), "%u", mask);
 204                         CHECK(buffer_putstr(&b, "/"));
 205                         CHECK(buffer_putstr(&b, str));
 206                         CHECK(buffer_putstr(&b, ";\n"));
 207                 }
 208                 CHECK(buffer_putstr(&b, "\t\t\t};\n"));
 209                 CHECK(buffer_putstr(&b, "\t\t};\n"));
 210                 CHECK(buffer_putstr(&b, "\t};\n"));
 211         }
 212
 213         CHECK(buffer_putstr(&b, "};\n\n"));
 214
 215         CHECK(buffer_putstr(&b, "lwres {\n"));
 216
 217         /*
 218          * Build the search path
 219          */
 220         if (lwc->searchnxt > 0) {
 221                 if (lwc->searchnxt > 0) {
 222                         CHECK(buffer_putstr(&b, "\tsearch {\n"));
 223                         for (i = 0; i < lwc->searchnxt; i++) {
 224                                 CHECK(buffer_putstr(&b, "\t\t\""));
 225                                 CHECK(buffer_putstr(&b, lwc->search[i]));
 226                                 CHECK(buffer_putstr(&b, "\";\n"));
 227                         }
 228                         CHECK(buffer_putstr(&b, "\t};\n"));
 229                 }
 230         }
 231
 232         /*
 233          * Build the ndots line
 234          */
 235         if (lwc->ndots != 1) {
 236                 CHECK(buffer_putstr(&b, "\tndots "));
 237                 snprintf(str, sizeof(str), "%u", lwc->ndots);
 238                 CHECK(buffer_putstr(&b, str));
 239                 CHECK(buffer_putstr(&b, ";\n"));
 240         }
 241
 242         /*
 243          * Build the listen-on line
 244          */
 245         if (lwc->lwnext > 0) {
 246                 CHECK(buffer_putstr(&b, "\tlisten-on {\n"));
 247
 248                 for (i = 0; i < lwc->lwnext; i++) {
 249                         CHECK(lwaddr_sockaddr_fromlwresaddr(&sa,
 250                                                             &lwc->lwservers[i],
 251                                                             0));
 252                         isc_netaddr_fromsockaddr(&na, &sa);
 253                         CHECK(buffer_putstr(&b, "\t\t"));
 254                         CHECK(isc_netaddr_totext(&na, &b));
 255                         CHECK(buffer_putstr(&b, ";\n"));
 256                 }
 257                 CHECK(buffer_putstr(&b, "\t};\n"));
 258         }
 259
 260         CHECK(buffer_putstr(&b, "};\n"));
 261
 262 #if 0
 263         printf("%.*s\n",
 264                (int)isc_buffer_usedlength(&b),
 265                (char *)isc_buffer_base(&b));
 266 #endif
 267
 268         lwres_conf_clear(lwctx);
 269         lwres_context_destroy(&lwctx);
 270
 271         return (cfg_parse_buffer(pctx, &b, &cfg_type_namedconf, configp));
 272
 273  cleanup:
 274
 275         if (lwctx != NULL) {
 276                 lwres_conf_clear(lwctx);
 277                 lwres_context_destroy(&lwctx);
 278         }
 279
 280         return (result);
 281 }
 282
 283
 284 /*
 285  * Handle lwresd manager objects
 286  */
 287 isc_result_t
 288 ns_lwdmanager_create(isc_mem_t *mctx, const cfg_obj_t *lwres,
 289                      ns_lwresd_t **lwresdp)
 290 {
 291         ns_lwresd_t *lwresd;
 292         const char *vname;
 293         dns_rdataclass_t vclass;
 294         const cfg_obj_t *obj, *viewobj, *searchobj;
 295         const cfg_listelt_t *element;
 296         isc_result_t result;
 297
 298         INSIST(lwresdp != NULL && *lwresdp == NULL);
 299
 300         lwresd = isc_mem_get(mctx, sizeof(ns_lwresd_t));
 301         if (lwresd == NULL)
 302                 return (ISC_R_NOMEMORY);
 303
 304         lwresd->mctx = NULL;
 305         isc_mem_attach(mctx, &lwresd->mctx);
 306         lwresd->view = NULL;
 307         lwresd->search = NULL;
 308         lwresd->refs = 1;
 309
 310         obj = NULL;
 311         (void)cfg_map_get(lwres, "ndots", &obj);
 312         if (obj != NULL)
 313                 lwresd->ndots = cfg_obj_asuint32(obj);
 314         else
 315                 lwresd->ndots = 1;
 316
 317         RUNTIME_CHECK(isc_mutex_init(&lwresd->lock) == ISC_R_SUCCESS);
 318
 319         lwresd->shutting_down = ISC_FALSE;
 320
 321         viewobj = NULL;
 322         (void)cfg_map_get(lwres, "view", &viewobj);
 323         if (viewobj != NULL) {
 324                 vname = cfg_obj_asstring(cfg_tuple_get(viewobj, "name"));
 325                 obj = cfg_tuple_get(viewobj, "class");
 326                 result = ns_config_getclass(obj, dns_rdataclass_in, &vclass);
 327                 if (result != ISC_R_SUCCESS)
 328                         goto fail;
 329         } else {
 330                 vname = "_default";
 331                 vclass = dns_rdataclass_in;
 332         }
 333
 334         result = dns_viewlist_find(&ns_g_server->viewlist, vname, vclass,
 335                                    &lwresd->view);
 336         if (result != ISC_R_SUCCESS) {
 337                 isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
 338                               NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
 339                               "couldn't find view %s", vname);
 340                 goto fail;
 341         }
 342
 343         searchobj = NULL;
 344         (void)cfg_map_get(lwres, "search", &searchobj);
 345         if (searchobj != NULL) {
 346                 lwresd->search = NULL;
 347                 result = ns_lwsearchlist_create(lwresd->mctx,
 348                                                 &lwresd->search);
 349                 if (result != ISC_R_SUCCESS) {
 350                         isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
 351                                       NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
 352                                       "couldn't create searchlist");
 353                         goto fail;
 354                 }
 355                 for (element = cfg_list_first(searchobj);
 356                      element != NULL;
 357                      element = cfg_list_next(element))
 358                 {
 359                         const cfg_obj_t *search;
 360                         const char *searchstr;
 361                         isc_buffer_t namebuf;
 362                         dns_fixedname_t fname;
 363                         dns_name_t *name;
 364
 365                         search = cfg_listelt_value(element);
 366                         searchstr = cfg_obj_asstring(search);
 367
 368                         dns_fixedname_init(&fname);
 369                         name = dns_fixedname_name(&fname);
 370                         isc_buffer_init(&namebuf, searchstr,
 371                                         strlen(searchstr));
 372                         isc_buffer_add(&namebuf, strlen(searchstr));
 373                         result = dns_name_fromtext(name, &namebuf,
 374                                                    dns_rootname, ISC_FALSE,
 375                                                    NULL);
 376                         if (result != ISC_R_SUCCESS) {
 377                                 isc_log_write(ns_g_lctx,
 378                                               NS_LOGCATEGORY_GENERAL,
 379                                               NS_LOGMODULE_LWRESD,
 380                                               ISC_LOG_WARNING,
 381                                               "invalid name %s in searchlist",
 382                                               searchstr);
 383                                 continue;
 384                         }
 385
 386                         result = ns_lwsearchlist_append(lwresd->search, name);
 387                         if (result != ISC_R_SUCCESS) {
 388                                 isc_log_write(ns_g_lctx,
 389                                               NS_LOGCATEGORY_GENERAL,
 390                                               NS_LOGMODULE_LWRESD,
 391                                               ISC_LOG_WARNING,
 392                                               "couldn't update searchlist");
 393                                 goto fail;
 394                         }
 395                 }
 396         }
 397
 398         lwresd->magic = LWRESD_MAGIC;
 399
 400         *lwresdp = lwresd;
 401         return (ISC_R_SUCCESS);
 402
 403  fail:
 404         if (lwresd->view != NULL)
 405                 dns_view_detach(&lwresd->view);
 406         if (lwresd->search != NULL)
 407                 ns_lwsearchlist_detach(&lwresd->search);
 408         if (lwresd->mctx != NULL)
 409                 isc_mem_detach(&lwresd->mctx);
 410         isc_mem_put(mctx, lwresd, sizeof(ns_lwresd_t));
 411         return (result);
 412 }
 413
 414 void
 415 ns_lwdmanager_attach(ns_lwresd_t *source, ns_lwresd_t **targetp) {
 416         INSIST(VALID_LWRESD(source));
 417         INSIST(targetp != NULL && *targetp == NULL);
 418
 419         LOCK(&source->lock);
 420         source->refs++;
 421         UNLOCK(&source->lock);
 422
 423         *targetp = source;
 424 }
 425
 426 void
 427 ns_lwdmanager_detach(ns_lwresd_t **lwresdp) {
 428         ns_lwresd_t *lwresd;
 429         isc_mem_t *mctx;
 430         isc_boolean_t done = ISC_FALSE;
 431
 432         INSIST(lwresdp != NULL && *lwresdp != NULL);
 433         INSIST(VALID_LWRESD(*lwresdp));
 434
 435         lwresd = *lwresdp;
 436         *lwresdp = NULL;
 437
 438         LOCK(&lwresd->lock);
 439         INSIST(lwresd->refs > 0);
 440         lwresd->refs--;
 441         if (lwresd->refs == 0)
 442                 done = ISC_TRUE;
 443         UNLOCK(&lwresd->lock);
 444
 445         if (!done)
 446                 return;
 447
 448         dns_view_detach(&lwresd->view);
 449         if (lwresd->search != NULL)
 450                 ns_lwsearchlist_detach(&lwresd->search);
 451         mctx = lwresd->mctx;
 452         lwresd->magic = 0;
 453         isc_mem_put(mctx, lwresd, sizeof(*lwresd));
 454         isc_mem_detach(&mctx);
 455 }
 456
 457
 458 /*
 459  * Handle listener objects
 460  */
 461 void
 462 ns_lwreslistener_attach(ns_lwreslistener_t *source,
 463                         ns_lwreslistener_t **targetp)
 464 {
 465         INSIST(VALID_LWRESLISTENER(source));
 466         INSIST(targetp != NULL && *targetp == NULL);
 467
 468         LOCK(&source->lock);
 469         source->refs++;
 470         UNLOCK(&source->lock);
 471
 472         *targetp = source;
 473 }
 474
 475 void
 476 ns_lwreslistener_detach(ns_lwreslistener_t **listenerp) {
 477         ns_lwreslistener_t *listener;
 478         isc_mem_t *mctx;
 479         isc_boolean_t done = ISC_FALSE;
 480
 481         INSIST(listenerp != NULL && *listenerp != NULL);
 482         INSIST(VALID_LWRESLISTENER(*listenerp));
 483
 484         listener = *listenerp;
 485
 486         LOCK(&listener->lock);
 487         INSIST(listener->refs > 0);
 488         listener->refs--;
 489         if (listener->refs == 0)
 490                 done = ISC_TRUE;
 491         UNLOCK(&listener->lock);
 492
 493         if (!done)
 494                 return;
 495
 496         if (listener->manager != NULL)
 497                 ns_lwdmanager_detach(&listener->manager);
 498
 499         if (listener->sock != NULL)
 500                 isc_socket_detach(&listener->sock);
 501
 502         listener->magic = 0;
 503         mctx = listener->mctx;
 504         isc_mem_put(mctx, listener, sizeof(*listener));
 505         isc_mem_detach(&mctx);
 506         listenerp = NULL;
 507 }
 508
 509 static isc_result_t
 510 listener_create(isc_mem_t *mctx, ns_lwresd_t *lwresd,
 511                 ns_lwreslistener_t **listenerp)
 512 {
 513         ns_lwreslistener_t *listener;
 514
 515         REQUIRE(listenerp != NULL && *listenerp == NULL);
 516
 517         listener = isc_mem_get(mctx, sizeof(ns_lwreslistener_t));
 518         if (listener == NULL)
 519                 return (ISC_R_NOMEMORY);
 520         RUNTIME_CHECK(isc_mutex_init(&listener->lock) == ISC_R_SUCCESS);
 521
 522         listener->magic = LWRESLISTENER_MAGIC;
 523         listener->refs = 1;
 524
 525         listener->sock = NULL;
 526
 527         listener->manager = NULL;
 528         ns_lwdmanager_attach(lwresd, &listener->manager);
 529
 530         listener->mctx = NULL;
 531         isc_mem_attach(mctx, &listener->mctx);
 532
 533         ISC_LINK_INIT(listener, link);
 534         ISC_LIST_INIT(listener->cmgrs);
 535
 536         *listenerp = listener;
 537         return (ISC_R_SUCCESS);
 538 }
 539
 540 static isc_result_t
 541 listener_bind(ns_lwreslistener_t *listener, isc_sockaddr_t *address) {
 542         isc_socket_t *sock = NULL;
 543         isc_result_t result = ISC_R_SUCCESS;
 544         int pf;
 545
 546         pf = isc_sockaddr_pf(address);
 547         if ((pf == AF_INET && isc_net_probeipv4() != ISC_R_SUCCESS) ||
 548             (pf == AF_INET6 && isc_net_probeipv6() != ISC_R_SUCCESS))
 549                 return (ISC_R_FAMILYNOSUPPORT);
 550
 551         listener->address = *address;
 552
 553         if (isc_sockaddr_getport(&listener->address) == 0) {
 554                 in_port_t port;
 555                 port = lwresd_g_listenport;
 556                 if (port == 0)
 557                         port = LWRES_UDP_PORT;
 558                 isc_sockaddr_setport(&listener->address, port);
 559         }
 560
 561         sock = NULL;
 562         result = isc_socket_create(ns_g_socketmgr, pf,
 563                                    isc_sockettype_udp, &sock);
 564         if (result != ISC_R_SUCCESS) {
 565                 isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
 566                               NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
 567                               "failed to create lwres socket: %s",
 568                               isc_result_totext(result));
 569                 return (result);
 570         }
 571
 572         result = isc_socket_bind(sock, &listener->address);
 573         if (result != ISC_R_SUCCESS) {
 574                 char socktext[ISC_SOCKADDR_FORMATSIZE];
 575                 isc_sockaddr_format(&listener->address, socktext,
 576                                     sizeof(socktext));
 577                 isc_socket_detach(&sock);
 578                 isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
 579                               NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
 580                               "failed to add lwres socket: %s: %s",
 581                               socktext, isc_result_totext(result));
 582                 return (result);
 583         }
 584         listener->sock = sock;
 585         return (ISC_R_SUCCESS);
 586 }
 587
 588 static void
 589 listener_copysock(ns_lwreslistener_t *oldlistener,
 590                   ns_lwreslistener_t *newlistener)
 591 {
 592         newlistener->address = oldlistener->address;
 593         isc_socket_attach(oldlistener->sock, &newlistener->sock);
 594 }
 595
 596 static isc_result_t
 597 listener_startclients(ns_lwreslistener_t *listener) {
 598         ns_lwdclientmgr_t *cm;
 599         unsigned int i;
 600         isc_result_t result;
 601
 602         /*
 603          * Create the client managers.
 604          */
 605         result = ISC_R_SUCCESS;
 606         for (i = 0; i < NTASKS && result == ISC_R_SUCCESS; i++)
 607                 result = ns_lwdclientmgr_create(listener, NRECVS,
 608                                                 ns_g_taskmgr);
 609
 610         /*
 611          * Ensure that we have created at least one.
 612          */
 613         if (ISC_LIST_EMPTY(listener->cmgrs))
 614                 return (result);
 615
 616         /*
 617          * Walk the list of clients and start each one up.
 618          */
 619         LOCK(&listener->lock);
 620         cm = ISC_LIST_HEAD(listener->cmgrs);
 621         while (cm != NULL) {
 622                 result = ns_lwdclient_startrecv(cm);
 623                 if (result != ISC_R_SUCCESS)
 624                         isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
 625                                       NS_LOGMODULE_LWRESD, ISC_LOG_ERROR,
 626                                       "could not start lwres "
 627                                       "client handler: %s",
 628                                       isc_result_totext(result));
 629                 cm = ISC_LIST_NEXT(cm, link);
 630         }
 631         UNLOCK(&listener->lock);
 632
 633         return (ISC_R_SUCCESS);
 634 }
 635
 636 static void
 637 listener_shutdown(ns_lwreslistener_t *listener) {
 638         ns_lwdclientmgr_t *cm;
 639
 640         cm = ISC_LIST_HEAD(listener->cmgrs);
 641         while (cm != NULL) {
 642                 isc_task_shutdown(cm->task);
 643                 cm = ISC_LIST_NEXT(cm, link);
 644         }
 645 }
 646
 647 static isc_result_t
 648 find_listener(isc_sockaddr_t *address, ns_lwreslistener_t **listenerp) {
 649         ns_lwreslistener_t *listener;
 650
 651         INSIST(listenerp != NULL && *listenerp == NULL);
 652
 653         for (listener = ISC_LIST_HEAD(listeners);
 654              listener != NULL;
 655              listener = ISC_LIST_NEXT(listener, link))
 656         {
 657                 if (!isc_sockaddr_equal(address, &listener->address))
 658                         continue;
 659                 *listenerp = listener;
 660                 return (ISC_R_SUCCESS);
 661         }
 662         return (ISC_R_NOTFOUND);
 663 }
 664
 665 void
 666 ns_lwreslistener_unlinkcm(ns_lwreslistener_t *listener, ns_lwdclientmgr_t *cm)
 667 {
 668         REQUIRE(VALID_LWRESLISTENER(listener));
 669
 670         LOCK(&listener->lock);
 671         ISC_LIST_UNLINK(listener->cmgrs, cm, link);
 672         UNLOCK(&listener->lock);
 673 }
 674
 675 void
 676 ns_lwreslistener_linkcm(ns_lwreslistener_t *listener, ns_lwdclientmgr_t *cm) {
 677         REQUIRE(VALID_LWRESLISTENER(listener));
 678
 679         /*
 680          * This does no locking, since it's called early enough that locking
 681          * isn't needed.
 682          */
 683         ISC_LIST_APPEND(listener->cmgrs, cm, link);
 684 }
 685
 686 static isc_result_t
 687 configure_listener(isc_sockaddr_t *address, ns_lwresd_t *lwresd,
 688                    isc_mem_t *mctx, ns_lwreslistenerlist_t *newlisteners)
 689 {
 690         ns_lwreslistener_t *listener, *oldlistener = NULL;
 691         char socktext[ISC_SOCKADDR_FORMATSIZE];
 692         isc_result_t result;
 693
 694         (void)find_listener(address, &oldlistener);
 695         listener = NULL;
 696         result = listener_create(mctx, lwresd, &listener);
 697         if (result != ISC_R_SUCCESS) {
 698                 isc_sockaddr_format(address, socktext, sizeof(socktext));
 699                 isc_log_write(ns_g_lctx, ISC_LOGCATEGORY_GENERAL,
 700                               NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
 701                               "lwres failed to configure %s: %s",
 702                               socktext, isc_result_totext(result));
 703                 return (result);
 704         }
 705
 706         /*
 707          * If there's already a listener, don't rebind the socket.
 708          */
 709         if (oldlistener == NULL) {
 710                 result = listener_bind(listener, address);
 711                 if (result != ISC_R_SUCCESS) {
 712                         ns_lwreslistener_detach(&listener);
 713                         return (ISC_R_SUCCESS);
 714                 }
 715         } else
 716                 listener_copysock(oldlistener, listener);
 717
 718         result = listener_startclients(listener);
 719         if (result != ISC_R_SUCCESS) {
 720                 isc_sockaddr_format(address, socktext, sizeof(socktext));
 721                 isc_log_write(ns_g_lctx, ISC_LOGCATEGORY_GENERAL,
 722                               NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
 723                               "lwres: failed to start %s: %s", socktext,
 724                               isc_result_totext(result));
 725                 ns_lwreslistener_detach(&listener);
 726                 return (ISC_R_SUCCESS);
 727         }
 728
 729         if (oldlistener != NULL) {
 730                 /*
 731                  * Remove the old listener from the old list and shut it down.
 732                  */
 733                 ISC_LIST_UNLINK(listeners, oldlistener, link);
 734                 listener_shutdown(oldlistener);
 735                 ns_lwreslistener_detach(&oldlistener);
 736         } else {
 737                 isc_sockaddr_format(address, socktext, sizeof(socktext));
 738                 isc_log_write(ns_g_lctx, ISC_LOGCATEGORY_GENERAL,
 739                               NS_LOGMODULE_LWRESD, ISC_LOG_NOTICE,
 740                               "lwres listening on %s", socktext);
 741         }
 742
 743         ISC_LIST_APPEND(*newlisteners, listener, link);
 744         return (result);
 745 }
 746
 747 isc_result_t
 748 ns_lwresd_configure(isc_mem_t *mctx, const cfg_obj_t *config) {
 749         const cfg_obj_t *lwreslist = NULL;
 750         const cfg_obj_t *lwres = NULL;
 751         const cfg_obj_t *listenerslist = NULL;
 752         const cfg_listelt_t *element = NULL;
 753         ns_lwreslistener_t *listener;
 754         ns_lwreslistenerlist_t newlisteners;
 755         isc_result_t result;
 756         char socktext[ISC_SOCKADDR_FORMATSIZE];
 757         isc_sockaddr_t *addrs = NULL;
 758         ns_lwresd_t *lwresd = NULL;
 759         isc_uint32_t count = 0;
 760
 761         REQUIRE(mctx != NULL);
 762         REQUIRE(config != NULL);
 763
 764         RUNTIME_CHECK(isc_once_do(&once, initialize_mutex) == ISC_R_SUCCESS);
 765
 766         ISC_LIST_INIT(newlisteners);
 767
 768         result = cfg_map_get(config, "lwres", &lwreslist);
 769         if (result != ISC_R_SUCCESS)
 770                 return (ISC_R_SUCCESS);
 771
 772         LOCK(&listeners_lock);
 773         /*
 774          * Run through the new lwres address list, noting sockets that
 775          * are already being listened on and moving them to the new list.
 776          *
 777          * Identifying duplicates addr/port combinations is left to either
 778          * the underlying config code, or to the bind attempt getting an
 779          * address-in-use error.
 780          */
 781         for (element = cfg_list_first(lwreslist);
 782              element != NULL;
 783              element = cfg_list_next(element))
 784         {
 785                 in_port_t port;
 786
 787                 lwres = cfg_listelt_value(element);
 788                 CHECK(ns_lwdmanager_create(mctx, lwres, &lwresd));
 789
 790                 port = lwresd_g_listenport;
 791                 if (port == 0)
 792                         port = LWRES_UDP_PORT;
 793
 794                 listenerslist = NULL;
 795                 (void)cfg_map_get(lwres, "listen-on", &listenerslist);
 796                 if (listenerslist == NULL) {
 797                         struct in_addr localhost;
 798                         isc_sockaddr_t address;
 799
 800                         localhost.s_addr = htonl(INADDR_LOOPBACK);
 801                         isc_sockaddr_fromin(&address, &localhost, port);
 802                         CHECK(configure_listener(&address, lwresd, mctx,
 803                                                  &newlisteners));
 804                 } else {
 805                         isc_uint32_t i;
 806
 807                         CHECK(ns_config_getiplist(config, listenerslist,
 808                                                   port, mctx, &addrs, &count));
 809                         for (i = 0; i < count; i++)
 810                                 CHECK(configure_listener(&addrs[i], lwresd,
 811                                                          mctx, &newlisteners));
 812                         ns_config_putiplist(mctx, &addrs, count);
 813                 }
 814                 ns_lwdmanager_detach(&lwresd);
 815         }
 816
 817         /*
 818          * Shutdown everything on the listeners list, and remove them from
 819          * the list.  Then put all of the new listeners on it.
 820          */
 821
 822         while (!ISC_LIST_EMPTY(listeners)) {
 823                 listener = ISC_LIST_HEAD(listeners);
 824                 ISC_LIST_UNLINK(listeners, listener, link);
 825
 826                 isc_sockaddr_format(&listener->address,
 827                                     socktext, sizeof(socktext));
 828
 829                 listener_shutdown(listener);
 830                 ns_lwreslistener_detach(&listener);
 831
 832                 isc_log_write(ns_g_lctx, ISC_LOGCATEGORY_GENERAL,
 833                               NS_LOGMODULE_LWRESD, ISC_LOG_NOTICE,
 834                               "lwres no longer listening on %s", socktext);
 835         }
 836
 837  cleanup:
 838         ISC_LIST_APPENDLIST(listeners, newlisteners, link);
 839
 840         if (addrs != NULL)
 841                 ns_config_putiplist(mctx, &addrs, count);
 842
 843         if (lwresd != NULL)
 844                 ns_lwdmanager_detach(&lwresd);
 845
 846         UNLOCK(&listeners_lock);
 847
 848         return (result);
 849 }
 850
 851 void
 852 ns_lwresd_shutdown(void) {
 853         ns_lwreslistener_t *listener;
 854
 855         RUNTIME_CHECK(isc_once_do(&once, initialize_mutex) == ISC_R_SUCCESS);
 856
 857         while (!ISC_LIST_EMPTY(listeners)) {
 858                 listener = ISC_LIST_HEAD(listeners);
 859                 ISC_LIST_UNLINK(listeners, listener, link);
 860                 ns_lwreslistener_detach(&listener);
 861         }
 862 }