res/res_pjsip_transport_websocket.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 2013, Digium, Inc.
   5  *
   6  * Jason Parker <jparker@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*!
  20  * \brief WebSocket transport module
  21  */
  22
  23 /*** MODULEINFO
  24         <depend>pjproject</depend>
  25         <depend>res_pjsip</depend>
  26         <depend>res_http_websocket</depend>
  27         <support_level>core</support_level>
  28  ***/
  29
  30 #include "asterisk.h"
  31
  32 #include <pjsip.h>
  33 #include <pjsip_ua.h>
  34
  35 #include "asterisk/module.h"
  36 #include "asterisk/http_websocket.h"
  37 #include "asterisk/res_pjsip.h"
  38 #include "asterisk/res_pjsip_session.h"
  39 #include "asterisk/taskprocessor.h"
  40
  41 static int transport_type_ws;
  42 static int transport_type_wss;
  43
  44 /*!
  45  * \brief Wrapper for pjsip_transport, for storing the WebSocket session
  46  */
  47 struct ws_transport {
  48         pjsip_transport transport;
  49         pjsip_rx_data rdata;
  50         struct ast_websocket *ws_session;
  51 };
  52
  53 /*!
  54  * \brief Send a message over the WebSocket connection.
  55  *
  56  * Called by pjsip transport manager.
  57  */
  58 static pj_status_t ws_send_msg(pjsip_transport *transport,
  59                             pjsip_tx_data *tdata,
  60                             const pj_sockaddr_t *rem_addr,
  61                             int addr_len,
  62                             void *token,
  63                             pjsip_transport_callback callback)
  64 {
  65         struct ws_transport *wstransport = (struct ws_transport *)transport;
  66         uint64_t len = tdata->buf.cur - tdata->buf.start;
  67
  68         if (ast_websocket_write(wstransport->ws_session, AST_WEBSOCKET_OPCODE_TEXT, tdata->buf.start, len)) {
  69                 return PJ_EUNKNOWN;
  70         }
  71
  72         return PJ_SUCCESS;
  73 }
  74
  75 /*!
  76  * \brief Destroy the pjsip transport.
  77  *
  78  * Called by pjsip transport manager.
  79  */
  80 static pj_status_t ws_destroy(pjsip_transport *transport)
  81 {
  82         struct ws_transport *wstransport = (struct ws_transport *)transport;
  83         int fd = ast_websocket_fd(wstransport->ws_session);
  84
  85         if (fd > 0) {
  86                 ast_websocket_close(wstransport->ws_session, 1000);
  87                 shutdown(fd, SHUT_RDWR);
  88         }
  89
  90         ao2_ref(wstransport, -1);
  91
  92         return PJ_SUCCESS;
  93 }
  94
  95 static void transport_dtor(void *arg)
  96 {
  97         struct ws_transport *wstransport = arg;
  98
  99         if (wstransport->ws_session) {
 100                 ast_websocket_unref(wstransport->ws_session);
 101         }
 102
 103         if (wstransport->transport.ref_cnt) {
 104                 pj_atomic_destroy(wstransport->transport.ref_cnt);
 105         }
 106
 107         if (wstransport->transport.lock) {
 108                 pj_lock_destroy(wstransport->transport.lock);
 109         }
 110
 111         if (wstransport->transport.endpt && wstransport->transport.pool) {
 112                 pjsip_endpt_release_pool(wstransport->transport.endpt, wstransport->transport.pool);
 113         }
 114
 115         if (wstransport->rdata.tp_info.pool) {
 116                 pjsip_endpt_release_pool(wstransport->transport.endpt, wstransport->rdata.tp_info.pool);
 117         }
 118 }
 119
 120 static int transport_shutdown(void *data)
 121 {
 122         struct ws_transport *wstransport = data;
 123
 124         if (!wstransport->transport.is_shutdown && !wstransport->transport.is_destroying) {
 125                 pjsip_transport_shutdown(&wstransport->transport);
 126         }
 127
 128         /* Note that the destructor calls PJSIP functions,
 129          * therefore it must be called in a PJSIP thread.
 130          */
 131         ao2_ref(wstransport, -1);
 132
 133         return 0;
 134 }
 135
 136 struct transport_create_data {
 137         struct ws_transport *transport;
 138         struct ast_websocket *ws_session;
 139 };
 140
 141 /*!
 142  * \brief Create a pjsip transport.
 143  */
 144 static int transport_create(void *data)
 145 {
 146         struct transport_create_data *create_data = data;
 147         struct ws_transport *newtransport = NULL;
 148
 149         pjsip_endpoint *endpt = ast_sip_get_pjsip_endpoint();
 150         struct pjsip_tpmgr *tpmgr = pjsip_endpt_get_tpmgr(endpt);
 151
 152         pj_pool_t *pool;
 153         pj_str_t buf;
 154         pj_status_t status;
 155
 156         newtransport = ao2_t_alloc_options(sizeof(*newtransport), transport_dtor,
 157                         AO2_ALLOC_OPT_LOCK_NOLOCK, "pjsip websocket transport");
 158         if (!newtransport) {
 159                 ast_log(LOG_ERROR, "Failed to allocate WebSocket transport.\n");
 160                 goto on_error;
 161         }
 162
 163         newtransport->transport.endpt = endpt;
 164
 165         if (!(pool = pjsip_endpt_create_pool(endpt, "ws", 512, 512))) {
 166                 ast_log(LOG_ERROR, "Failed to allocate WebSocket endpoint pool.\n");
 167                 goto on_error;
 168         }
 169
 170         newtransport->transport.pool = pool;
 171         newtransport->ws_session = create_data->ws_session;
 172
 173         /* Keep the session until transport dies */
 174         ast_websocket_ref(newtransport->ws_session);
 175
 176         status = pj_atomic_create(pool, 0, &newtransport->transport.ref_cnt);
 177         if (status != PJ_SUCCESS) {
 178                 goto on_error;
 179         }
 180
 181         status = pj_lock_create_recursive_mutex(pool, pool->obj_name, &newtransport->transport.lock);
 182         if (status != PJ_SUCCESS) {
 183                 goto on_error;
 184         }
 185
 186         pj_sockaddr_parse(pj_AF_UNSPEC(), 0, pj_cstr(&buf, ast_sockaddr_stringify(ast_websocket_remote_address(newtransport->ws_session))), &newtransport->transport.key.rem_addr);
 187         newtransport->transport.key.rem_addr.addr.sa_family = pj_AF_INET();
 188         newtransport->transport.key.type = ast_websocket_is_secure(newtransport->ws_session) ? transport_type_wss : transport_type_ws;
 189
 190         newtransport->transport.addr_len = pj_sockaddr_get_len(&newtransport->transport.key.rem_addr);
 191
 192         pj_sockaddr_cp(&newtransport->transport.local_addr, &newtransport->transport.key.rem_addr);
 193
 194         newtransport->transport.local_name.host.ptr = (char *)pj_pool_alloc(pool, newtransport->transport.addr_len+4);
 195         pj_sockaddr_print(&newtransport->transport.key.rem_addr, newtransport->transport.local_name.host.ptr, newtransport->transport.addr_len+4, 0);
 196         newtransport->transport.local_name.host.slen = pj_ansi_strlen(newtransport->transport.local_name.host.ptr);
 197         newtransport->transport.local_name.port = pj_sockaddr_get_port(&newtransport->transport.key.rem_addr);
 198
 199         newtransport->transport.type_name = (char *)pjsip_transport_get_type_name(newtransport->transport.key.type);
 200         newtransport->transport.flag = pjsip_transport_get_flag_from_type((pjsip_transport_type_e)newtransport->transport.key.type);
 201         newtransport->transport.info = (char *)pj_pool_alloc(newtransport->transport.pool, 64);
 202
 203         newtransport->transport.tpmgr = tpmgr;
 204         newtransport->transport.send_msg = &ws_send_msg;
 205         newtransport->transport.destroy = &ws_destroy;
 206
 207         status = pjsip_transport_register(newtransport->transport.tpmgr,
 208                         (pjsip_transport *)newtransport);
 209         if (status != PJ_SUCCESS) {
 210                 goto on_error;
 211         }
 212
 213         /* Add a reference for pjsip transport manager */
 214         ao2_ref(newtransport, +1);
 215
 216         newtransport->rdata.tp_info.transport = &newtransport->transport;
 217         newtransport->rdata.tp_info.pool = pjsip_endpt_create_pool(endpt, "rtd%p",
 218                 PJSIP_POOL_RDATA_LEN, PJSIP_POOL_RDATA_INC);
 219         if (!newtransport->rdata.tp_info.pool) {
 220                 ast_log(LOG_ERROR, "Failed to allocate WebSocket rdata.\n");
 221                 pjsip_transport_destroy((pjsip_transport *)newtransport);
 222                 goto on_error;
 223         }
 224
 225         create_data->transport = newtransport;
 226         return 0;
 227
 228 on_error:
 229         ao2_cleanup(newtransport);
 230         return -1;
 231 }
 232
 233 struct transport_read_data {
 234         struct ws_transport *transport;
 235         char *payload;
 236         uint64_t payload_len;
 237 };
 238
 239 /*!
 240  * \brief Pass WebSocket data into pjsip transport manager.
 241  */
 242 static int transport_read(void *data)
 243 {
 244         struct transport_read_data *read_data = data;
 245         struct ws_transport *newtransport = read_data->transport;
 246         struct ast_websocket *session = newtransport->ws_session;
 247
 248         pjsip_rx_data *rdata = &newtransport->rdata;
 249         int recvd;
 250         pj_str_t buf;
 251         int pjsip_pkt_len;
 252
 253         pj_gettimeofday(&rdata->pkt_info.timestamp);
 254
 255         pjsip_pkt_len = PJSIP_MAX_PKT_LEN < read_data->payload_len ? PJSIP_MAX_PKT_LEN : read_data->payload_len;
 256         pj_memcpy(rdata->pkt_info.packet, read_data->payload, pjsip_pkt_len);
 257         rdata->pkt_info.len = pjsip_pkt_len;
 258         rdata->pkt_info.zero = 0;
 259
 260         pj_sockaddr_parse(pj_AF_UNSPEC(), 0, pj_cstr(&buf, ast_sockaddr_stringify(ast_websocket_remote_address(session))), &rdata->pkt_info.src_addr);
 261         rdata->pkt_info.src_addr.addr.sa_family = pj_AF_INET();
 262
 263         rdata->pkt_info.src_addr_len = sizeof(rdata->pkt_info.src_addr);
 264
 265         pj_ansi_strcpy(rdata->pkt_info.src_name, ast_sockaddr_stringify_host(ast_websocket_remote_address(session)));
 266         rdata->pkt_info.src_port = ast_sockaddr_port(ast_websocket_remote_address(session));
 267
 268         recvd = pjsip_tpmgr_receive_packet(rdata->tp_info.transport->tpmgr, rdata);
 269
 270         pj_pool_reset(rdata->tp_info.pool);
 271
 272         return (read_data->payload_len == recvd) ? 0 : -1;
 273 }
 274
 275 static int get_write_timeout(void)
 276 {
 277         int write_timeout = -1;
 278         struct ao2_container *transports;
 279
 280         transports = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "transport", AST_RETRIEVE_FLAG_ALL, NULL);
 281
 282         if (transports) {
 283                 struct ao2_iterator it_transports = ao2_iterator_init(transports, 0);
 284                 struct ast_sip_transport *transport;
 285
 286                 for (; (transport = ao2_iterator_next(&it_transports)); ao2_cleanup(transport)) {
 287                         if (transport->type != AST_TRANSPORT_WS && transport->type != AST_TRANSPORT_WSS) {
 288                                 continue;
 289                         }
 290                         ast_debug(5, "Found %s transport with write timeout: %d\n",
 291                                 transport->type == AST_TRANSPORT_WS ? "WS" : "WSS",
 292                                 transport->write_timeout);
 293                         write_timeout = MAX(write_timeout, transport->write_timeout);
 294                 }
 295                 ao2_cleanup(transports);
 296         }
 297
 298         if (write_timeout < 0) {
 299                 write_timeout = AST_DEFAULT_WEBSOCKET_WRITE_TIMEOUT;
 300         }
 301
 302         ast_debug(1, "Write timeout for WS/WSS transports: %d\n", write_timeout);
 303         return write_timeout;
 304 }
 305
 306 /*!
 307  \brief WebSocket connection handler.
 308  */
 309 static void websocket_cb(struct ast_websocket *session, struct ast_variable *parameters, struct ast_variable *headers)
 310 {
 311         struct ast_taskprocessor *serializer = NULL;
 312         struct transport_create_data create_data;
 313         struct ws_transport *transport = NULL;
 314         struct transport_read_data read_data;
 315
 316         if (ast_websocket_set_nonblock(session)) {
 317                 ast_websocket_unref(session);
 318                 return;
 319         }
 320
 321         if (ast_websocket_set_timeout(session, get_write_timeout())) {
 322                 ast_websocket_unref(session);
 323                 return;
 324         }
 325
 326         if (!(serializer = ast_sip_create_serializer())) {
 327                 ast_websocket_unref(session);
 328                 return;
 329         }
 330
 331         create_data.ws_session = session;
 332
 333         if (ast_sip_push_task_synchronous(serializer, transport_create, &create_data)) {
 334                 ast_log(LOG_ERROR, "Could not create WebSocket transport.\n");
 335                 ast_websocket_unref(session);
 336                 return;
 337         }
 338
 339         transport = create_data.transport;
 340         read_data.transport = transport;
 341
 342         while (ast_wait_for_input(ast_websocket_fd(session), -1) > 0) {
 343                 enum ast_websocket_opcode opcode;
 344                 int fragmented;
 345
 346                 if (ast_websocket_read(session, &read_data.payload, &read_data.payload_len, &opcode, &fragmented)) {
 347                         break;
 348                 }
 349
 350                 if (opcode == AST_WEBSOCKET_OPCODE_TEXT || opcode == AST_WEBSOCKET_OPCODE_BINARY) {
 351                         ast_sip_push_task_synchronous(serializer, transport_read, &read_data);
 352                 } else if (opcode == AST_WEBSOCKET_OPCODE_CLOSE) {
 353                         break;
 354                 }
 355         }
 356
 357         ast_sip_push_task_synchronous(serializer, transport_shutdown, transport);
 358
 359         ast_taskprocessor_unreference(serializer);
 360         ast_websocket_unref(session);
 361 }
 362
 363 /*!
 364  * \brief Store the transport a message came in on, so it can be used for outbound messages to that contact.
 365  */
 366 static pj_bool_t websocket_on_rx_msg(pjsip_rx_data *rdata)
 367 {
 368         static const pj_str_t STR_WS = { "ws", 2 };
 369         static const pj_str_t STR_WSS = { "wss", 3 };
 370         pjsip_contact_hdr *contact;
 371
 372         long type = rdata->tp_info.transport->key.type;
 373
 374         if (type != (long)transport_type_ws && type != (long)transport_type_wss) {
 375                 return PJ_FALSE;
 376         }
 377
 378         if ((contact = pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_CONTACT, NULL)) && !contact->star &&
 379                 (PJSIP_URI_SCHEME_IS_SIP(contact->uri) || PJSIP_URI_SCHEME_IS_SIPS(contact->uri))) {
 380                 pjsip_sip_uri *uri = pjsip_uri_get_uri(contact->uri);
 381
 382                 pj_cstr(&uri->host, rdata->pkt_info.src_name);
 383                 uri->port = rdata->pkt_info.src_port;
 384                 ast_debug(4, "Re-wrote Contact URI host/port to %.*s:%d\n",
 385                         (int)pj_strlen(&uri->host), pj_strbuf(&uri->host), uri->port);
 386                 pj_strdup(rdata->tp_info.pool, &uri->transport_param, (type == (long)transport_type_ws) ? &STR_WS : &STR_WSS);
 387         }
 388
 389         rdata->msg_info.via->rport_param = 0;
 390
 391         return PJ_FALSE;
 392 }
 393
 394 static pjsip_module websocket_module = {
 395         .name = { "WebSocket Transport Module", 26 },
 396         .id = -1,
 397         .priority = PJSIP_MOD_PRIORITY_TRANSPORT_LAYER,
 398         .on_rx_request = websocket_on_rx_msg,
 399         .on_rx_response = websocket_on_rx_msg,
 400 };
 401
 402 /*! \brief Function called when an INVITE goes out */
 403 static void websocket_outgoing_invite_request(struct ast_sip_session *session, struct pjsip_tx_data *tdata)
 404 {
 405         if (session->inv_session->state == PJSIP_INV_STATE_NULL) {
 406                 pjsip_dlg_add_usage(session->inv_session->dlg, &websocket_module, NULL);
 407         }
 408 }
 409
 410 /*! \brief Supplement for adding Websocket functionality to dialog */
 411 static struct ast_sip_session_supplement websocket_supplement = {
 412         .method = "INVITE",
 413         .priority = AST_SIP_SUPPLEMENT_PRIORITY_FIRST + 1,
 414         .outgoing_request = websocket_outgoing_invite_request,
 415 };
 416
 417 static int load_module(void)
 418 {
 419         CHECK_PJSIP_MODULE_LOADED();
 420
 421         pjsip_transport_register_type(PJSIP_TRANSPORT_RELIABLE, "WS", 5060, &transport_type_ws);
 422         pjsip_transport_register_type(PJSIP_TRANSPORT_RELIABLE, "WSS", 5060, &transport_type_wss);
 423
 424         if (ast_sip_register_service(&websocket_module) != PJ_SUCCESS) {
 425                 return AST_MODULE_LOAD_DECLINE;
 426         }
 427
 428         if (ast_sip_session_register_supplement(&websocket_supplement)) {
 429                 ast_sip_unregister_service(&websocket_module);
 430                 return AST_MODULE_LOAD_DECLINE;
 431         }
 432
 433         if (ast_websocket_add_protocol("sip", websocket_cb)) {
 434                 ast_sip_session_unregister_supplement(&websocket_supplement);
 435                 ast_sip_unregister_service(&websocket_module);
 436                 return AST_MODULE_LOAD_DECLINE;
 437         }
 438
 439         return AST_MODULE_LOAD_SUCCESS;
 440 }
 441
 442 static int unload_module(void)
 443 {
 444         ast_sip_unregister_service(&websocket_module);
 445         ast_sip_session_unregister_supplement(&websocket_supplement);
 446         ast_websocket_remove_protocol("sip", websocket_cb);
 447
 448         return 0;
 449 }
 450
 451 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP WebSocket Transport Support",
 452         .support_level = AST_MODULE_SUPPORT_CORE,
 453         .load = load_module,
 454         .unload = unload_module,
 455         .load_pri = AST_MODPRI_APP_DEPEND,
 456 );