Alexandre Lision | 8af73cb | 2013-12-10 14:11:20 -0500 | [diff] [blame] | 1 | /* $Id$ */ |
| 2 | /* |
| 3 | * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) |
| 4 | * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 19 | */ |
| 20 | #include <pjsip/sip_resolve.h> |
| 21 | #include <pjsip/sip_transport.h> |
| 22 | #include <pjsip/sip_errno.h> |
| 23 | #include <pjlib-util/errno.h> |
| 24 | #include <pjlib-util/srv_resolver.h> |
| 25 | #include <pj/addr_resolv.h> |
| 26 | #include <pj/array.h> |
| 27 | #include <pj/assert.h> |
| 28 | #include <pj/ctype.h> |
| 29 | #include <pj/log.h> |
| 30 | #include <pj/pool.h> |
| 31 | #include <pj/rand.h> |
| 32 | #include <pj/string.h> |
| 33 | |
| 34 | |
| 35 | #define THIS_FILE "sip_resolve.c" |
| 36 | |
| 37 | #define ADDR_MAX_COUNT 8 |
| 38 | |
| 39 | struct naptr_target |
| 40 | { |
| 41 | pj_str_t res_type; /**< e.g. "_sip._udp" */ |
| 42 | pj_str_t name; /**< Domain name. */ |
| 43 | pjsip_transport_type_e type; /**< Transport type. */ |
| 44 | unsigned order; /**< Order */ |
| 45 | unsigned pref; /**< Preference. */ |
| 46 | }; |
| 47 | |
| 48 | struct query |
| 49 | { |
| 50 | char *objname; |
| 51 | |
| 52 | pj_dns_type query_type; |
| 53 | void *token; |
| 54 | pjsip_resolver_callback *cb; |
| 55 | pj_dns_async_query *object; |
| 56 | pj_status_t last_error; |
| 57 | |
| 58 | /* Original request: */ |
| 59 | struct { |
| 60 | pjsip_host_info target; |
| 61 | unsigned def_port; |
| 62 | } req; |
| 63 | |
| 64 | /* NAPTR records: */ |
| 65 | unsigned naptr_cnt; |
| 66 | struct naptr_target naptr[8]; |
| 67 | }; |
| 68 | |
| 69 | |
| 70 | struct pjsip_resolver_t |
| 71 | { |
| 72 | pj_dns_resolver *res; |
| 73 | }; |
| 74 | |
| 75 | |
| 76 | static void srv_resolver_cb(void *user_data, |
| 77 | pj_status_t status, |
| 78 | const pj_dns_srv_record *rec); |
| 79 | static void dns_a_callback(void *user_data, |
| 80 | pj_status_t status, |
| 81 | pj_dns_parsed_packet *response); |
| 82 | |
| 83 | |
| 84 | /* |
| 85 | * Public API to create the resolver. |
| 86 | */ |
| 87 | PJ_DEF(pj_status_t) pjsip_resolver_create( pj_pool_t *pool, |
| 88 | pjsip_resolver_t **p_res) |
| 89 | { |
| 90 | pjsip_resolver_t *resolver; |
| 91 | |
| 92 | PJ_ASSERT_RETURN(pool && p_res, PJ_EINVAL); |
| 93 | resolver = PJ_POOL_ZALLOC_T(pool, pjsip_resolver_t); |
| 94 | *p_res = resolver; |
| 95 | |
| 96 | return PJ_SUCCESS; |
| 97 | } |
| 98 | |
| 99 | |
| 100 | /* |
| 101 | * Public API to set the DNS resolver instance for the SIP resolver. |
| 102 | */ |
| 103 | PJ_DEF(pj_status_t) pjsip_resolver_set_resolver(pjsip_resolver_t *res, |
| 104 | pj_dns_resolver *dns_res) |
| 105 | { |
| 106 | #if PJSIP_HAS_RESOLVER |
| 107 | res->res = dns_res; |
| 108 | return PJ_SUCCESS; |
| 109 | #else |
| 110 | PJ_UNUSED_ARG(res); |
| 111 | PJ_UNUSED_ARG(dns_res); |
| 112 | pj_assert(!"Resolver is disabled (PJSIP_HAS_RESOLVER==0)"); |
| 113 | return PJ_EINVALIDOP; |
| 114 | #endif |
| 115 | } |
| 116 | |
| 117 | |
| 118 | /* |
| 119 | * Public API to get the internal DNS resolver. |
| 120 | */ |
| 121 | PJ_DEF(pj_dns_resolver*) pjsip_resolver_get_resolver(pjsip_resolver_t *res) |
| 122 | { |
| 123 | return res->res; |
| 124 | } |
| 125 | |
| 126 | |
| 127 | /* |
| 128 | * Public API to create destroy the resolver |
| 129 | */ |
| 130 | PJ_DEF(void) pjsip_resolver_destroy(pjsip_resolver_t *resolver) |
| 131 | { |
| 132 | if (resolver->res) { |
| 133 | #if PJSIP_HAS_RESOLVER |
| 134 | pj_dns_resolver_destroy(resolver->res, PJ_FALSE); |
| 135 | #endif |
| 136 | resolver->res = NULL; |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * Internal: |
| 142 | * determine if an address is a valid IP address, and if it is, |
| 143 | * return the IP version (4 or 6). |
| 144 | */ |
| 145 | static int get_ip_addr_ver(const pj_str_t *host) |
| 146 | { |
| 147 | pj_in_addr dummy; |
| 148 | pj_in6_addr dummy6; |
| 149 | |
| 150 | /* First check with inet_aton() */ |
| 151 | if (pj_inet_aton(host, &dummy) > 0) |
| 152 | return 4; |
| 153 | |
| 154 | /* Then check if this is an IPv6 address */ |
| 155 | if (pj_inet_pton(pj_AF_INET6(), host, &dummy6) == PJ_SUCCESS) |
| 156 | return 6; |
| 157 | |
| 158 | /* Not an IP address */ |
| 159 | return 0; |
| 160 | } |
| 161 | |
| 162 | |
| 163 | /* |
| 164 | * This is the main function for performing server resolution. |
| 165 | */ |
| 166 | PJ_DEF(void) pjsip_resolve( pjsip_resolver_t *resolver, |
| 167 | pj_pool_t *pool, |
| 168 | const pjsip_host_info *target, |
| 169 | void *token, |
| 170 | pjsip_resolver_callback *cb) |
| 171 | { |
| 172 | pjsip_server_addresses svr_addr; |
| 173 | pj_status_t status = PJ_SUCCESS; |
| 174 | int ip_addr_ver; |
| 175 | struct query *query; |
| 176 | pjsip_transport_type_e type = target->type; |
| 177 | |
| 178 | /* Is it IP address or hostname? And if it's an IP, which version? */ |
| 179 | ip_addr_ver = get_ip_addr_ver(&target->addr.host); |
| 180 | |
| 181 | /* Set the transport type if not explicitly specified. |
| 182 | * RFC 3263 section 4.1 specify rules to set up this. |
| 183 | */ |
| 184 | if (type == PJSIP_TRANSPORT_UNSPECIFIED) { |
| 185 | if (ip_addr_ver || (target->addr.port != 0)) { |
| 186 | #if PJ_HAS_TCP |
| 187 | if (target->flag & PJSIP_TRANSPORT_SECURE) |
| 188 | { |
| 189 | type = PJSIP_TRANSPORT_TLS; |
| 190 | } else if (target->flag & PJSIP_TRANSPORT_RELIABLE) |
| 191 | { |
| 192 | type = PJSIP_TRANSPORT_TCP; |
| 193 | } else |
| 194 | #endif |
| 195 | { |
| 196 | type = PJSIP_TRANSPORT_UDP; |
| 197 | } |
| 198 | } else { |
| 199 | /* No type or explicit port is specified, and the address is |
| 200 | * not IP address. |
| 201 | * In this case, full NAPTR resolution must be performed. |
| 202 | * But we don't support it (yet). |
| 203 | */ |
| 204 | #if PJ_HAS_TCP |
| 205 | if (target->flag & PJSIP_TRANSPORT_SECURE) |
| 206 | { |
| 207 | type = PJSIP_TRANSPORT_TLS; |
| 208 | } else if (target->flag & PJSIP_TRANSPORT_RELIABLE) |
| 209 | { |
| 210 | type = PJSIP_TRANSPORT_TCP; |
| 211 | } else |
| 212 | #endif |
| 213 | { |
| 214 | type = PJSIP_TRANSPORT_UDP; |
| 215 | } |
| 216 | } |
| 217 | |
| 218 | /* Add IPv6 flag for IPv6 address */ |
| 219 | if (ip_addr_ver == 6) |
| 220 | type = (pjsip_transport_type_e)((int)type + PJSIP_TRANSPORT_IPV6); |
| 221 | } |
| 222 | |
| 223 | |
| 224 | /* If target is an IP address, or if resolver is not configured, |
| 225 | * we can just finish the resolution now using pj_gethostbyname() |
| 226 | */ |
| 227 | if (ip_addr_ver || resolver->res == NULL) { |
| 228 | char addr_str[PJ_INET6_ADDRSTRLEN+10]; |
| 229 | pj_uint16_t srv_port; |
| 230 | |
| 231 | if (ip_addr_ver != 0) { |
| 232 | /* Target is an IP address, no need to resolve */ |
| 233 | if (ip_addr_ver == 4) { |
| 234 | pj_sockaddr_init(pj_AF_INET(), &svr_addr.entry[0].addr, |
| 235 | NULL, 0); |
| 236 | pj_inet_aton(&target->addr.host, |
| 237 | &svr_addr.entry[0].addr.ipv4.sin_addr); |
| 238 | } else { |
| 239 | pj_sockaddr_init(pj_AF_INET6(), &svr_addr.entry[0].addr, |
| 240 | NULL, 0); |
| 241 | pj_inet_pton(pj_AF_INET6(), &target->addr.host, |
| 242 | &svr_addr.entry[0].addr.ipv6.sin6_addr); |
| 243 | } |
| 244 | } else { |
| 245 | pj_addrinfo ai; |
| 246 | unsigned count; |
| 247 | int af; |
| 248 | |
| 249 | PJ_LOG(5,(THIS_FILE, |
| 250 | "DNS resolver not available, target '%.*s:%d' type=%s " |
| 251 | "will be resolved with getaddrinfo()", |
| 252 | target->addr.host.slen, |
| 253 | target->addr.host.ptr, |
| 254 | target->addr.port, |
| 255 | pjsip_transport_get_type_name(target->type))); |
| 256 | |
| 257 | if (type & PJSIP_TRANSPORT_IPV6) { |
| 258 | af = pj_AF_INET6(); |
| 259 | } else { |
| 260 | af = pj_AF_INET(); |
| 261 | } |
| 262 | |
| 263 | /* Resolve */ |
| 264 | count = 1; |
| 265 | status = pj_getaddrinfo(af, &target->addr.host, &count, &ai); |
| 266 | if (status != PJ_SUCCESS) { |
| 267 | /* "Normalize" error to PJ_ERESOLVE. This is a special error |
| 268 | * because it will be translated to SIP status 502 by |
| 269 | * sip_transaction.c |
| 270 | */ |
| 271 | status = PJ_ERESOLVE; |
| 272 | goto on_error; |
| 273 | } |
| 274 | |
| 275 | svr_addr.entry[0].addr.addr.sa_family = (pj_uint16_t)af; |
| 276 | pj_memcpy(&svr_addr.entry[0].addr, &ai.ai_addr, |
| 277 | sizeof(pj_sockaddr)); |
| 278 | } |
| 279 | |
| 280 | /* Set the port number */ |
| 281 | if (target->addr.port == 0) { |
| 282 | srv_port = (pj_uint16_t) |
| 283 | pjsip_transport_get_default_port_for_type(type); |
| 284 | } else { |
| 285 | srv_port = (pj_uint16_t)target->addr.port; |
| 286 | } |
| 287 | pj_sockaddr_set_port(&svr_addr.entry[0].addr, srv_port); |
| 288 | |
| 289 | /* Call the callback. */ |
| 290 | PJ_LOG(5,(THIS_FILE, |
| 291 | "Target '%.*s:%d' type=%s resolved to " |
| 292 | "'%s' type=%s (%s)", |
| 293 | (int)target->addr.host.slen, |
| 294 | target->addr.host.ptr, |
| 295 | target->addr.port, |
| 296 | pjsip_transport_get_type_name(target->type), |
| 297 | pj_sockaddr_print(&svr_addr.entry[0].addr, addr_str, |
| 298 | sizeof(addr_str), 3), |
| 299 | pjsip_transport_get_type_name(type), |
| 300 | pjsip_transport_get_type_desc(type))); |
| 301 | svr_addr.count = 1; |
| 302 | svr_addr.entry[0].priority = 0; |
| 303 | svr_addr.entry[0].weight = 0; |
| 304 | svr_addr.entry[0].type = type; |
| 305 | svr_addr.entry[0].addr_len = pj_sockaddr_get_len(&svr_addr.entry[0].addr); |
| 306 | (*cb)(status, token, &svr_addr); |
| 307 | |
| 308 | /* Done. */ |
| 309 | return; |
| 310 | } |
| 311 | |
| 312 | /* Target is not an IP address so we need to resolve it. */ |
| 313 | #if PJSIP_HAS_RESOLVER |
| 314 | |
| 315 | /* Build the query state */ |
| 316 | query = PJ_POOL_ZALLOC_T(pool, struct query); |
| 317 | query->objname = THIS_FILE; |
| 318 | query->token = token; |
| 319 | query->cb = cb; |
| 320 | query->req.target = *target; |
| 321 | pj_strdup(pool, &query->req.target.addr.host, &target->addr.host); |
| 322 | |
| 323 | /* If port is not specified, start with SRV resolution |
| 324 | * (should be with NAPTR, but we'll do that later) |
| 325 | */ |
| 326 | PJ_TODO(SUPPORT_DNS_NAPTR); |
| 327 | |
| 328 | /* Build dummy NAPTR entry */ |
| 329 | query->naptr_cnt = 1; |
| 330 | pj_bzero(&query->naptr[0], sizeof(query->naptr[0])); |
| 331 | query->naptr[0].order = 0; |
| 332 | query->naptr[0].pref = 0; |
| 333 | query->naptr[0].type = type; |
| 334 | pj_strdup(pool, &query->naptr[0].name, &target->addr.host); |
| 335 | |
| 336 | |
| 337 | /* Start DNS SRV or A resolution, depending on whether port is specified */ |
| 338 | if (target->addr.port == 0) { |
| 339 | query->query_type = PJ_DNS_TYPE_SRV; |
| 340 | |
| 341 | query->req.def_port = 5060; |
| 342 | |
| 343 | if (type == PJSIP_TRANSPORT_TLS) { |
| 344 | query->naptr[0].res_type = pj_str("_sips._tcp."); |
| 345 | query->req.def_port = 5061; |
| 346 | } else if (type == PJSIP_TRANSPORT_TCP) |
| 347 | query->naptr[0].res_type = pj_str("_sip._tcp."); |
| 348 | else if (type == PJSIP_TRANSPORT_UDP) |
| 349 | query->naptr[0].res_type = pj_str("_sip._udp."); |
| 350 | else { |
| 351 | pj_assert(!"Unknown transport type"); |
| 352 | query->naptr[0].res_type = pj_str("_sip._udp."); |
| 353 | |
| 354 | } |
| 355 | |
| 356 | } else { |
| 357 | /* Otherwise if port is specified, start with A (or AAAA) host |
| 358 | * resolution |
| 359 | */ |
| 360 | query->query_type = PJ_DNS_TYPE_A; |
| 361 | query->naptr[0].res_type.slen = 0; |
| 362 | query->req.def_port = target->addr.port; |
| 363 | } |
| 364 | |
| 365 | /* Start the asynchronous query */ |
| 366 | PJ_LOG(5, (query->objname, |
| 367 | "Starting async DNS %s query: target=%.*s%.*s, transport=%s, " |
| 368 | "port=%d", |
| 369 | pj_dns_get_type_name(query->query_type), |
| 370 | (int)query->naptr[0].res_type.slen, |
| 371 | query->naptr[0].res_type.ptr, |
| 372 | (int)query->naptr[0].name.slen, query->naptr[0].name.ptr, |
| 373 | pjsip_transport_get_type_name(target->type), |
| 374 | target->addr.port)); |
| 375 | |
| 376 | if (query->query_type == PJ_DNS_TYPE_SRV) { |
| 377 | |
| 378 | status = pj_dns_srv_resolve(&query->naptr[0].name, |
| 379 | &query->naptr[0].res_type, |
| 380 | query->req.def_port, pool, resolver->res, |
| 381 | PJ_TRUE, query, &srv_resolver_cb, NULL); |
| 382 | |
| 383 | } else if (query->query_type == PJ_DNS_TYPE_A) { |
| 384 | |
| 385 | status = pj_dns_resolver_start_query(resolver->res, |
| 386 | &query->naptr[0].name, |
| 387 | PJ_DNS_TYPE_A, 0, |
| 388 | &dns_a_callback, |
| 389 | query, &query->object); |
| 390 | |
| 391 | } else { |
| 392 | pj_assert(!"Unexpected"); |
| 393 | status = PJ_EBUG; |
| 394 | } |
| 395 | |
| 396 | if (status != PJ_SUCCESS) |
| 397 | goto on_error; |
| 398 | |
| 399 | return; |
| 400 | |
| 401 | #else /* PJSIP_HAS_RESOLVER */ |
| 402 | PJ_UNUSED_ARG(pool); |
| 403 | PJ_UNUSED_ARG(query); |
| 404 | PJ_UNUSED_ARG(srv_name); |
| 405 | #endif /* PJSIP_HAS_RESOLVER */ |
| 406 | |
| 407 | on_error: |
| 408 | if (status != PJ_SUCCESS) { |
| 409 | char errmsg[PJ_ERR_MSG_SIZE]; |
| 410 | PJ_LOG(4,(THIS_FILE, "Failed to resolve '%.*s'. Err=%d (%s)", |
| 411 | (int)target->addr.host.slen, |
| 412 | target->addr.host.ptr, |
| 413 | status, |
| 414 | pj_strerror(status,errmsg,sizeof(errmsg)).ptr)); |
| 415 | (*cb)(status, token, NULL); |
| 416 | return; |
| 417 | } |
| 418 | } |
| 419 | |
| 420 | #if PJSIP_HAS_RESOLVER |
| 421 | |
| 422 | /* |
| 423 | * This callback is called when target is resolved with DNS A query. |
| 424 | */ |
| 425 | static void dns_a_callback(void *user_data, |
| 426 | pj_status_t status, |
| 427 | pj_dns_parsed_packet *pkt) |
| 428 | { |
| 429 | struct query *query = (struct query*) user_data; |
| 430 | pjsip_server_addresses srv; |
| 431 | pj_dns_a_record rec; |
| 432 | unsigned i; |
| 433 | |
| 434 | rec.addr_count = 0; |
| 435 | |
| 436 | /* Parse the response */ |
| 437 | if (status == PJ_SUCCESS) { |
| 438 | status = pj_dns_parse_a_response(pkt, &rec); |
| 439 | } |
| 440 | |
| 441 | if (status != PJ_SUCCESS) { |
| 442 | char errmsg[PJ_ERR_MSG_SIZE]; |
| 443 | |
| 444 | /* Log error */ |
| 445 | pj_strerror(status, errmsg, sizeof(errmsg)); |
| 446 | PJ_LOG(4,(query->objname, "DNS A record resolution failed: %s", |
| 447 | errmsg)); |
| 448 | |
| 449 | /* Call the callback */ |
| 450 | (*query->cb)(status, query->token, NULL); |
| 451 | return; |
| 452 | } |
| 453 | |
| 454 | /* Build server addresses and call callback */ |
| 455 | srv.count = 0; |
| 456 | for (i=0; i<rec.addr_count; ++i) { |
| 457 | srv.entry[srv.count].type = query->naptr[0].type; |
| 458 | srv.entry[srv.count].priority = 0; |
| 459 | srv.entry[srv.count].weight = 0; |
| 460 | srv.entry[srv.count].addr_len = sizeof(pj_sockaddr_in); |
| 461 | pj_sockaddr_in_init(&srv.entry[srv.count].addr.ipv4, |
| 462 | 0, (pj_uint16_t)query->req.def_port); |
| 463 | srv.entry[srv.count].addr.ipv4.sin_addr.s_addr = |
| 464 | rec.addr[i].s_addr; |
| 465 | |
| 466 | ++srv.count; |
| 467 | } |
| 468 | |
| 469 | /* Call the callback */ |
| 470 | (*query->cb)(PJ_SUCCESS, query->token, &srv); |
| 471 | } |
| 472 | |
| 473 | |
| 474 | /* Callback to be called by DNS SRV resolution */ |
| 475 | static void srv_resolver_cb(void *user_data, |
| 476 | pj_status_t status, |
| 477 | const pj_dns_srv_record *rec) |
| 478 | { |
| 479 | struct query *query = (struct query*) user_data; |
| 480 | pjsip_server_addresses srv; |
| 481 | unsigned i; |
| 482 | |
| 483 | if (status != PJ_SUCCESS) { |
| 484 | char errmsg[PJ_ERR_MSG_SIZE]; |
| 485 | |
| 486 | /* Log error */ |
| 487 | pj_strerror(status, errmsg, sizeof(errmsg)); |
| 488 | PJ_LOG(4,(query->objname, "DNS A record resolution failed: %s", |
| 489 | errmsg)); |
| 490 | |
| 491 | /* Call the callback */ |
| 492 | (*query->cb)(status, query->token, NULL); |
| 493 | return; |
| 494 | } |
| 495 | |
| 496 | /* Build server addresses and call callback */ |
| 497 | srv.count = 0; |
| 498 | for (i=0; i<rec->count; ++i) { |
| 499 | unsigned j; |
| 500 | |
| 501 | for (j=0; j<rec->entry[i].server.addr_count; ++j) { |
| 502 | srv.entry[srv.count].type = query->naptr[0].type; |
| 503 | srv.entry[srv.count].priority = rec->entry[i].priority; |
| 504 | srv.entry[srv.count].weight = rec->entry[i].weight; |
| 505 | srv.entry[srv.count].addr_len = sizeof(pj_sockaddr_in); |
| 506 | pj_sockaddr_in_init(&srv.entry[srv.count].addr.ipv4, |
| 507 | 0, (pj_uint16_t)rec->entry[i].port); |
| 508 | srv.entry[srv.count].addr.ipv4.sin_addr.s_addr = |
| 509 | rec->entry[i].server.addr[j].s_addr; |
| 510 | |
| 511 | ++srv.count; |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | /* Call the callback */ |
| 516 | (*query->cb)(PJ_SUCCESS, query->token, &srv); |
| 517 | } |
| 518 | |
| 519 | #endif /* PJSIP_HAS_RESOLVER */ |
| 520 | |