1429cceed8b1c3d1d1bc1dfd5fefbb8d087d80d1
[asterisk/asterisk.git] / 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_wss;
42 static int transport_type_wss_ipv6;
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         char *ws_addr_str;
153         pj_pool_t *pool;
154         pj_str_t buf;
155         pj_status_t status;
156
157         newtransport = ao2_t_alloc_options(sizeof(*newtransport), transport_dtor,
158                         AO2_ALLOC_OPT_LOCK_NOLOCK, "pjsip websocket transport");
159         if (!newtransport) {
160                 ast_log(LOG_ERROR, "Failed to allocate WebSocket transport.\n");
161                 goto on_error;
162         }
163
164         newtransport->transport.endpt = endpt;
165
166         if (!(pool = pjsip_endpt_create_pool(endpt, "ws", 512, 512))) {
167                 ast_log(LOG_ERROR, "Failed to allocate WebSocket endpoint pool.\n");
168                 goto on_error;
169         }
170
171         newtransport->transport.pool = pool;
172         newtransport->ws_session = create_data->ws_session;
173
174         /* Keep the session until transport dies */
175         ast_websocket_ref(newtransport->ws_session);
176
177         status = pj_atomic_create(pool, 0, &newtransport->transport.ref_cnt);
178         if (status != PJ_SUCCESS) {
179                 goto on_error;
180         }
181
182         status = pj_lock_create_recursive_mutex(pool, pool->obj_name, &newtransport->transport.lock);
183         if (status != PJ_SUCCESS) {
184                 goto on_error;
185         }
186
187         /*
188          * The type_name here is mostly used by log messages eihter in
189          * pjproject or Asterisk.  Other places are reconstituting subscriptions
190          * after a restart (which could never work for a websocket connection anyway),
191          * received MESSAGE requests to set PJSIP_TRANSPORT, and most importantly
192          * by pjproject when generating the Via header.
193          */
194         newtransport->transport.type_name = ast_websocket_is_secure(newtransport->ws_session)
195                 ? "WSS" : "WS";
196
197         ws_addr_str = ast_sockaddr_stringify(ast_websocket_remote_address(newtransport->ws_session));
198         ast_debug(4, "Creating websocket transport for %s:%s\n",
199                 newtransport->transport.type_name, ws_addr_str);
200
201         pj_sockaddr_parse(pj_AF_UNSPEC(), 0, pj_cstr(&buf, ws_addr_str), &newtransport->transport.key.rem_addr);
202         if (newtransport->transport.key.rem_addr.addr.sa_family == pj_AF_INET6()) {
203                 newtransport->transport.key.type = transport_type_wss_ipv6;
204                 newtransport->transport.local_name.host.ptr = (char *)pj_pool_alloc(pool, PJ_INET6_ADDRSTRLEN);
205                 pj_sockaddr_print(&newtransport->transport.key.rem_addr, newtransport->transport.local_name.host.ptr, PJ_INET6_ADDRSTRLEN, 0);
206         } else {
207                 newtransport->transport.key.type = transport_type_wss;
208                 newtransport->transport.local_name.host.ptr = (char *)pj_pool_alloc(pool, PJ_INET_ADDRSTRLEN);
209                 pj_sockaddr_print(&newtransport->transport.key.rem_addr, newtransport->transport.local_name.host.ptr, PJ_INET_ADDRSTRLEN, 0);
210         }
211
212         newtransport->transport.addr_len = pj_sockaddr_get_len(&newtransport->transport.key.rem_addr);
213
214         pj_sockaddr_cp(&newtransport->transport.local_addr, &newtransport->transport.key.rem_addr);
215
216         newtransport->transport.local_name.host.slen = pj_ansi_strlen(newtransport->transport.local_name.host.ptr);
217         newtransport->transport.local_name.port = pj_sockaddr_get_port(&newtransport->transport.key.rem_addr);
218
219         newtransport->transport.flag = pjsip_transport_get_flag_from_type((pjsip_transport_type_e)newtransport->transport.key.type);
220         newtransport->transport.info = (char *)pj_pool_alloc(newtransport->transport.pool, 64);
221
222         newtransport->transport.tpmgr = tpmgr;
223         newtransport->transport.send_msg = &ws_send_msg;
224         newtransport->transport.destroy = &ws_destroy;
225
226         status = pjsip_transport_register(newtransport->transport.tpmgr,
227                         (pjsip_transport *)newtransport);
228         if (status != PJ_SUCCESS) {
229                 goto on_error;
230         }
231
232         /* Add a reference for pjsip transport manager */
233         ao2_ref(newtransport, +1);
234
235         newtransport->rdata.tp_info.transport = &newtransport->transport;
236         newtransport->rdata.tp_info.pool = pjsip_endpt_create_pool(endpt, "rtd%p",
237                 PJSIP_POOL_RDATA_LEN, PJSIP_POOL_RDATA_INC);
238         if (!newtransport->rdata.tp_info.pool) {
239                 ast_log(LOG_ERROR, "Failed to allocate WebSocket rdata.\n");
240                 pjsip_transport_destroy((pjsip_transport *)newtransport);
241                 goto on_error;
242         }
243
244         create_data->transport = newtransport;
245         return 0;
246
247 on_error:
248         ao2_cleanup(newtransport);
249         return -1;
250 }
251
252 struct transport_read_data {
253         struct ws_transport *transport;
254         char *payload;
255         uint64_t payload_len;
256 };
257
258 /*!
259  * \brief Pass WebSocket data into pjsip transport manager.
260  */
261 static int transport_read(void *data)
262 {
263         struct transport_read_data *read_data = data;
264         struct ws_transport *newtransport = read_data->transport;
265         struct ast_websocket *session = newtransport->ws_session;
266
267         pjsip_rx_data *rdata = &newtransport->rdata;
268         int recvd;
269         pj_str_t buf;
270         int pjsip_pkt_len;
271
272         pj_gettimeofday(&rdata->pkt_info.timestamp);
273
274         pjsip_pkt_len = PJSIP_MAX_PKT_LEN < read_data->payload_len ? PJSIP_MAX_PKT_LEN : read_data->payload_len;
275         pj_memcpy(rdata->pkt_info.packet, read_data->payload, pjsip_pkt_len);
276         rdata->pkt_info.len = pjsip_pkt_len;
277         rdata->pkt_info.zero = 0;
278
279         pj_sockaddr_parse(pj_AF_UNSPEC(), 0, pj_cstr(&buf, ast_sockaddr_stringify(ast_websocket_remote_address(session))), &rdata->pkt_info.src_addr);
280         rdata->pkt_info.src_addr_len = sizeof(rdata->pkt_info.src_addr);
281
282         pj_ansi_strcpy(rdata->pkt_info.src_name, ast_sockaddr_stringify_host(ast_websocket_remote_address(session)));
283         rdata->pkt_info.src_port = ast_sockaddr_port(ast_websocket_remote_address(session));
284
285         recvd = pjsip_tpmgr_receive_packet(rdata->tp_info.transport->tpmgr, rdata);
286
287         pj_pool_reset(rdata->tp_info.pool);
288
289         return (read_data->payload_len == recvd) ? 0 : -1;
290 }
291
292 static int get_write_timeout(void)
293 {
294         int write_timeout = -1;
295         struct ao2_container *transport_states;
296
297         transport_states = ast_sip_get_transport_states();
298
299         if (transport_states) {
300                 struct ao2_iterator it_transport_states = ao2_iterator_init(transport_states, 0);
301                 struct ast_sip_transport_state *transport_state;
302
303                 for (; (transport_state = ao2_iterator_next(&it_transport_states)); ao2_cleanup(transport_state)) {
304                         struct ast_sip_transport *transport;
305
306                         if (transport_state->type != AST_TRANSPORT_WS && transport_state->type != AST_TRANSPORT_WSS) {
307                                 continue;
308                         }
309                         transport = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "transport", transport_state->id);
310                         if (!transport) {
311                                 continue;
312                         }
313                         ast_debug(5, "Found %s transport with write timeout: %d\n",
314                                 transport->type == AST_TRANSPORT_WS ? "WS" : "WSS",
315                                 transport->write_timeout);
316                         write_timeout = MAX(write_timeout, transport->write_timeout);
317                 }
318                 ao2_iterator_destroy(&it_transport_states);
319                 ao2_cleanup(transport_states);
320         }
321
322         if (write_timeout < 0) {
323                 write_timeout = AST_DEFAULT_WEBSOCKET_WRITE_TIMEOUT;
324         }
325
326         ast_debug(1, "Write timeout for WS/WSS transports: %d\n", write_timeout);
327         return write_timeout;
328 }
329
330 static struct ast_taskprocessor *create_websocket_serializer(void)
331 {
332         char tps_name[AST_TASKPROCESSOR_MAX_NAME + 1];
333
334         /* Create name with seq number appended. */
335         ast_taskprocessor_build_name(tps_name, sizeof(tps_name), "pjsip/websocket");
336
337         return ast_sip_create_serializer(tps_name);
338 }
339
340 /*! \brief WebSocket connection handler. */
341 static void websocket_cb(struct ast_websocket *session, struct ast_variable *parameters, struct ast_variable *headers)
342 {
343         struct ast_taskprocessor *serializer;
344         struct transport_create_data create_data;
345         struct ws_transport *transport;
346         struct transport_read_data read_data;
347
348         if (ast_websocket_set_nonblock(session)) {
349                 ast_websocket_unref(session);
350                 return;
351         }
352
353         if (ast_websocket_set_timeout(session, get_write_timeout())) {
354                 ast_websocket_unref(session);
355                 return;
356         }
357
358         serializer = create_websocket_serializer();
359         if (!serializer) {
360                 ast_websocket_unref(session);
361                 return;
362         }
363
364         create_data.ws_session = session;
365
366         if (ast_sip_push_task_synchronous(serializer, transport_create, &create_data)) {
367                 ast_log(LOG_ERROR, "Could not create WebSocket transport.\n");
368                 ast_taskprocessor_unreference(serializer);
369                 ast_websocket_unref(session);
370                 return;
371         }
372
373         transport = create_data.transport;
374         read_data.transport = transport;
375
376         while (ast_wait_for_input(ast_websocket_fd(session), -1) > 0) {
377                 enum ast_websocket_opcode opcode;
378                 int fragmented;
379
380                 if (ast_websocket_read(session, &read_data.payload, &read_data.payload_len, &opcode, &fragmented)) {
381                         break;
382                 }
383
384                 if (opcode == AST_WEBSOCKET_OPCODE_TEXT || opcode == AST_WEBSOCKET_OPCODE_BINARY) {
385                         ast_sip_push_task_synchronous(serializer, transport_read, &read_data);
386                 } else if (opcode == AST_WEBSOCKET_OPCODE_CLOSE) {
387                         break;
388                 }
389         }
390
391         ast_sip_push_task_synchronous(serializer, transport_shutdown, transport);
392
393         ast_taskprocessor_unreference(serializer);
394         ast_websocket_unref(session);
395 }
396
397 /*!
398  * \brief Store the transport a message came in on, so it can be used for outbound messages to that contact.
399  */
400 static pj_bool_t websocket_on_rx_msg(pjsip_rx_data *rdata)
401 {
402         static const pj_str_t STR_WS = { "ws", 2 };
403         pjsip_contact_hdr *contact;
404
405         long type = rdata->tp_info.transport->key.type;
406
407         if (type != (long) transport_type_wss && type != (long) transport_type_wss_ipv6) {
408                 return PJ_FALSE;
409         }
410
411         contact = pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_CONTACT, NULL);
412         if (contact
413                 && !contact->star
414                 && (PJSIP_URI_SCHEME_IS_SIP(contact->uri) || PJSIP_URI_SCHEME_IS_SIPS(contact->uri))) {
415                 pjsip_sip_uri *uri = pjsip_uri_get_uri(contact->uri);
416                 const pj_str_t *txp_str = &STR_WS;
417
418                 ast_debug(4, "%s re-writing Contact URI from %.*s:%d%s%.*s to %s:%d;transport=%s\n",
419                         pjsip_rx_data_get_info(rdata),
420                         (int)pj_strlen(&uri->host), pj_strbuf(&uri->host), uri->port,
421                         pj_strlen(&uri->transport_param) ? ";transport=" : "",
422                         (int)pj_strlen(&uri->transport_param), pj_strbuf(&uri->transport_param),
423                         rdata->pkt_info.src_name ?: "", rdata->pkt_info.src_port, pj_strbuf(txp_str));
424
425                 pj_cstr(&uri->host, rdata->pkt_info.src_name);
426                 uri->port = rdata->pkt_info.src_port;
427                 pj_strdup(rdata->tp_info.pool, &uri->transport_param, txp_str);
428         }
429
430         rdata->msg_info.via->rport_param = 0;
431
432         return PJ_FALSE;
433 }
434
435 static pjsip_module websocket_module = {
436         .name = { "WebSocket Transport Module", 26 },
437         .id = -1,
438         .priority = PJSIP_MOD_PRIORITY_TRANSPORT_LAYER,
439         .on_rx_request = websocket_on_rx_msg,
440         .on_rx_response = websocket_on_rx_msg,
441 };
442
443 /*! \brief Function called when an INVITE goes out */
444 static void websocket_outgoing_invite_request(struct ast_sip_session *session, struct pjsip_tx_data *tdata)
445 {
446         if (session->inv_session->state == PJSIP_INV_STATE_NULL) {
447                 pjsip_dlg_add_usage(session->inv_session->dlg, &websocket_module, NULL);
448         }
449 }
450
451 /*! \brief Supplement for adding Websocket functionality to dialog */
452 static struct ast_sip_session_supplement websocket_supplement = {
453         .method = "INVITE",
454         .priority = AST_SIP_SUPPLEMENT_PRIORITY_FIRST + 1,
455         .outgoing_request = websocket_outgoing_invite_request,
456 };
457
458 static int load_module(void)
459 {
460         CHECK_PJSIP_MODULE_LOADED();
461
462         /*
463          * We only need one transport type name (ws) defined.  Firefox
464          * and Chrome do not support anything other than secure websockets
465          * anymore.
466          *
467          * Also we really cannot have two transports with the same name
468          * and address family because it would be ambiguous.  Outgoing
469          * requests may try to find the transport by name and pjproject
470          * only finds the first one registered.
471          */
472         pjsip_transport_register_type(PJSIP_TRANSPORT_RELIABLE | PJSIP_TRANSPORT_SECURE, "ws", 5060, &transport_type_wss);
473         pjsip_transport_register_type(PJSIP_TRANSPORT_RELIABLE | PJSIP_TRANSPORT_SECURE | PJSIP_TRANSPORT_IPV6, "ws", 5060, &transport_type_wss_ipv6);
474
475         if (ast_sip_register_service(&websocket_module) != PJ_SUCCESS) {
476                 return AST_MODULE_LOAD_DECLINE;
477         }
478
479         if (ast_sip_session_register_supplement(&websocket_supplement)) {
480                 ast_sip_unregister_service(&websocket_module);
481                 return AST_MODULE_LOAD_DECLINE;
482         }
483
484         if (ast_websocket_add_protocol("sip", websocket_cb)) {
485                 ast_sip_session_unregister_supplement(&websocket_supplement);
486                 ast_sip_unregister_service(&websocket_module);
487                 return AST_MODULE_LOAD_DECLINE;
488         }
489
490         return AST_MODULE_LOAD_SUCCESS;
491 }
492
493 static int unload_module(void)
494 {
495         ast_sip_unregister_service(&websocket_module);
496         ast_sip_session_unregister_supplement(&websocket_supplement);
497         ast_websocket_remove_protocol("sip", websocket_cb);
498
499         return 0;
500 }
501
502 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP WebSocket Transport Support",
503         .support_level = AST_MODULE_SUPPORT_CORE,
504         .load = load_module,
505         .unload = unload_module,
506         .load_pri = AST_MODPRI_APP_DEPEND,
507 );