~singpolyma/asterisk

ref: 51af79b42e4ae7d1831603633d73bf0df179720e asterisk/main/endpoints.c -rw-r--r-- 12.5 KiB
51af79b4Christopher Vollick Content Created By Initiator 2: Electric Boogaloo 10 months ago
                                                                                
130ba7ae Bernhard Schmidt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * David M. Lee, II <dlee@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Asterisk endpoint API.
 *
 * \author David M. Lee, II <dlee@digium.com>
 */

/*** MODULEINFO
	<support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/astobj2.h"
#include "asterisk/endpoints.h"
#include "asterisk/stasis.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/stasis_endpoints.h"
#include "asterisk/stasis_message_router.h"
#include "asterisk/stringfields.h"
#include "asterisk/_private.h"

/*! Buckets for endpoint->channel mappings. Keep it prime! */
#define ENDPOINT_CHANNEL_BUCKETS 127

/*! Buckets for endpoint hash. Keep it prime! */
#define ENDPOINT_BUCKETS 127

/*! Buckets for technology endpoints. */
#define TECH_ENDPOINT_BUCKETS 11

static struct ao2_container *endpoints;

static struct ao2_container *tech_endpoints;

struct ast_endpoint {
	AST_DECLARE_STRING_FIELDS(
		AST_STRING_FIELD(tech);	/*!< Technology (SIP, IAX2, etc.). */
		AST_STRING_FIELD(resource);	/*!< Name, unique to the tech. */
		AST_STRING_FIELD(id);	/*!< tech/resource id */
		);
	/*! Endpoint's current state */
	enum ast_endpoint_state state;
	/*!
	 * \brief Max channels for this endpoint. -1 means unlimited or unknown.
	 *
	 * Note that this simply documents the limits of an endpoint, and does
	 * nothing to try to enforce the limit.
	 */
	int max_channels;
	/*! Topic for this endpoint's messages */
	struct stasis_cp_single *topics;
	/*! Router for handling this endpoint's messages */
	struct stasis_message_router *router;
	/*! ast_str_container of channels associated with this endpoint */
	struct ao2_container *channel_ids;
	/*! Forwarding subscription from an endpoint to its tech endpoint */
	struct stasis_forward *tech_forward;
};

AO2_STRING_FIELD_HASH_FN(ast_endpoint, id)
AO2_STRING_FIELD_CMP_FN(ast_endpoint, id)

struct ast_endpoint *ast_endpoint_find_by_id(const char *id)
{
	struct ast_endpoint *endpoint = ao2_find(endpoints, id, OBJ_KEY);

	if (!endpoint) {
		endpoint = ao2_find(tech_endpoints, id, OBJ_KEY);
	}

	return endpoint;
}

struct stasis_topic *ast_endpoint_topic(struct ast_endpoint *endpoint)
{
	if (!endpoint) {
		return ast_endpoint_topic_all();
	}
	return stasis_cp_single_topic(endpoint->topics);
}

struct stasis_topic *ast_endpoint_topic_cached(struct ast_endpoint *endpoint)
{
	if (!endpoint) {
		return ast_endpoint_topic_all_cached();
	}
	return stasis_cp_single_topic_cached(endpoint->topics);
}

const char *ast_endpoint_state_to_string(enum ast_endpoint_state state)
{
	switch (state) {
	case AST_ENDPOINT_UNKNOWN:
		return "unknown";
	case AST_ENDPOINT_OFFLINE:
		return "offline";
	case AST_ENDPOINT_ONLINE:
		return "online";
	}
	return "?";
}

static void endpoint_publish_snapshot(struct ast_endpoint *endpoint)
{
	RAII_VAR(struct ast_endpoint_snapshot *, snapshot, NULL, ao2_cleanup);
	RAII_VAR(struct stasis_message *, message, NULL, ao2_cleanup);

	ast_assert(endpoint != NULL);
	ast_assert(endpoint->topics != NULL);

	if (!ast_endpoint_snapshot_type()) {
		return;
	}

	snapshot = ast_endpoint_snapshot_create(endpoint);
	if (!snapshot) {
		return;
	}
	message = stasis_message_create(ast_endpoint_snapshot_type(), snapshot);
	if (!message) {
		return;
	}
	stasis_publish(ast_endpoint_topic(endpoint), message);
}

static void endpoint_dtor(void *obj)
{
	struct ast_endpoint *endpoint = obj;

	/* The router should be shut down already */
	ast_assert(stasis_message_router_is_done(endpoint->router));
	ao2_cleanup(endpoint->router);
	endpoint->router = NULL;

	stasis_cp_single_unsubscribe(endpoint->topics);
	endpoint->topics = NULL;

	ao2_cleanup(endpoint->channel_ids);
	endpoint->channel_ids = NULL;

	ast_string_field_free_memory(endpoint);
}


int ast_endpoint_add_channel(struct ast_endpoint *endpoint,
	struct ast_channel *chan)
{
	ast_assert(chan != NULL);
	ast_assert(endpoint != NULL);
	ast_assert(!ast_strlen_zero(endpoint->resource));

	ast_channel_forward_endpoint(chan, endpoint);

	ao2_lock(endpoint);
	ast_str_container_add(endpoint->channel_ids, ast_channel_uniqueid(chan));
	ao2_unlock(endpoint);

	endpoint_publish_snapshot(endpoint);

	return 0;
}

/*! \brief Handler for channel snapshot cache clears */
static void endpoint_cache_clear(void *data,
	struct stasis_subscription *sub,
	struct stasis_message *message)
{
	struct ast_endpoint *endpoint = data;
	struct stasis_message *clear_msg = stasis_message_data(message);
	struct ast_channel_snapshot *clear_snapshot;

	if (stasis_message_type(clear_msg) != ast_channel_snapshot_type()) {
		return;
	}

	clear_snapshot = stasis_message_data(clear_msg);

	ast_assert(endpoint != NULL);

	ao2_lock(endpoint);
	ast_str_container_remove(endpoint->channel_ids, clear_snapshot->uniqueid);
	ao2_unlock(endpoint);
	endpoint_publish_snapshot(endpoint);
}

static void endpoint_subscription_change(void *data,
	struct stasis_subscription *sub,
	struct stasis_message *message)
{
	struct stasis_endpoint *endpoint = data;

	if (stasis_subscription_final_message(sub, message)) {
		ao2_cleanup(endpoint);
	}
}

static struct ast_endpoint *endpoint_internal_create(const char *tech, const char *resource)
{
	RAII_VAR(struct ast_endpoint *, endpoint, NULL, ao2_cleanup);
	RAII_VAR(struct ast_endpoint *, tech_endpoint, NULL, ao2_cleanup);
	int r = 0;

	/* Get/create the technology endpoint */
	if (!ast_strlen_zero(resource)) {
		tech_endpoint = ao2_find(tech_endpoints, tech, OBJ_KEY);
		if (!tech_endpoint) {
			tech_endpoint = endpoint_internal_create(tech, NULL);
			if (!tech_endpoint) {
				return NULL;
			}
		}
	}

	endpoint = ao2_alloc(sizeof(*endpoint), endpoint_dtor);
	if (!endpoint) {
		return NULL;
	}

	endpoint->max_channels = -1;
	endpoint->state = AST_ENDPOINT_UNKNOWN;

	if (ast_string_field_init(endpoint, 80) != 0) {
		return NULL;
	}
	ast_string_field_set(endpoint, tech, tech);
	ast_string_field_set(endpoint, resource, S_OR(resource, ""));
	ast_string_field_build(endpoint, id, "%s%s%s",
		tech,
		!ast_strlen_zero(resource) ? "/" : "",
		S_OR(resource, ""));

	/* All access to channel_ids should be covered by the endpoint's
	 * lock; no extra lock needed. */
	endpoint->channel_ids = ast_str_container_alloc_options(
		AO2_ALLOC_OPT_LOCK_NOLOCK, ENDPOINT_CHANNEL_BUCKETS);
	if (!endpoint->channel_ids) {
		return NULL;
	}

	if (!ast_strlen_zero(resource)) {

		endpoint->topics = stasis_cp_single_create(ast_endpoint_cache_all(),
			endpoint->id);
		if (!endpoint->topics) {
			return NULL;
		}
		stasis_cp_single_accept_message_type(endpoint->topics, ast_endpoint_snapshot_type());
		stasis_cp_single_set_filter(endpoint->topics, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);

		endpoint->router = stasis_message_router_create_pool(ast_endpoint_topic(endpoint));
		if (!endpoint->router) {
			return NULL;
		}
		r |= stasis_message_router_add(endpoint->router,
			stasis_cache_clear_type(), endpoint_cache_clear,
			endpoint);
		r |= stasis_message_router_add(endpoint->router,
			stasis_subscription_change_type(), endpoint_subscription_change,
			endpoint);
		if (r) {
			return NULL;
		}

		endpoint->tech_forward = stasis_forward_all(stasis_cp_single_topic(endpoint->topics),
			stasis_cp_single_topic(tech_endpoint->topics));

		endpoint_publish_snapshot(endpoint);
		ao2_link(endpoints, endpoint);
	} else {
		endpoint->topics = stasis_cp_sink_create(ast_endpoint_cache_all(),
			endpoint->id);
		if (!endpoint->topics) {
			return NULL;
		}
		stasis_cp_single_accept_message_type(endpoint->topics, ast_endpoint_snapshot_type());
		stasis_cp_single_set_filter(endpoint->topics, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);

		ao2_link(tech_endpoints, endpoint);
	}

	ao2_ref(endpoint, +1);
	return endpoint;
}

struct ast_endpoint *ast_endpoint_create(const char *tech, const char *resource)
{
	if (ast_strlen_zero(tech)) {
		ast_log(LOG_ERROR, "Endpoint tech cannot be empty\n");
		return NULL;
	}

	if (ast_strlen_zero(resource)) {
		ast_log(LOG_ERROR, "Endpoint resource cannot be empty\n");
		return NULL;
	}

	return endpoint_internal_create(tech, resource);
}

static struct stasis_message *create_endpoint_snapshot_message(struct ast_endpoint *endpoint)
{
	RAII_VAR(struct ast_endpoint_snapshot *, snapshot, NULL, ao2_cleanup);

	if (!ast_endpoint_snapshot_type()) {
		return NULL;
	}

	snapshot = ast_endpoint_snapshot_create(endpoint);
	if (!snapshot) {
		return NULL;
	}

	return stasis_message_create(ast_endpoint_snapshot_type(), snapshot);
}

void ast_endpoint_shutdown(struct ast_endpoint *endpoint)
{
	RAII_VAR(struct stasis_message *, clear_msg, NULL, ao2_cleanup);

	if (endpoint == NULL) {
		return;
	}

	ao2_unlink(endpoints, endpoint);
	endpoint->tech_forward = stasis_forward_cancel(endpoint->tech_forward);

	clear_msg = create_endpoint_snapshot_message(endpoint);
	if (clear_msg) {
		RAII_VAR(struct stasis_message *, message, NULL, ao2_cleanup);
		message = stasis_cache_clear_create(clear_msg);
		if (message) {
			stasis_publish(ast_endpoint_topic(endpoint), message);
		}
	}

	/* Bump refcount to hold on to the router */
	ao2_ref(endpoint->router, +1);
	stasis_message_router_unsubscribe(endpoint->router);
}

const char *ast_endpoint_get_tech(const struct ast_endpoint *endpoint)
{
	if (!endpoint) {
		return NULL;
	}
	return endpoint->tech;
}

const char *ast_endpoint_get_resource(const struct ast_endpoint *endpoint)
{
	if (!endpoint) {
		return NULL;
	}
	return endpoint->resource;
}

const char *ast_endpoint_get_id(const struct ast_endpoint *endpoint)
{
	if (!endpoint) {
		return NULL;
	}
	return endpoint->id;
}

enum ast_endpoint_state ast_endpoint_get_state(const struct ast_endpoint *endpoint)
{
	if (!endpoint) {
		return AST_ENDPOINT_UNKNOWN;
	}
	return endpoint->state;
}

void ast_endpoint_set_state(struct ast_endpoint *endpoint,
	enum ast_endpoint_state state)
{
	ast_assert(endpoint != NULL);
	ast_assert(!ast_strlen_zero(endpoint->resource));

	ao2_lock(endpoint);
	endpoint->state = state;
	ao2_unlock(endpoint);
	endpoint_publish_snapshot(endpoint);
}

void ast_endpoint_set_max_channels(struct ast_endpoint *endpoint,
	int max_channels)
{
	ast_assert(endpoint != NULL);
	ast_assert(!ast_strlen_zero(endpoint->resource));

	ao2_lock(endpoint);
	endpoint->max_channels = max_channels;
	ao2_unlock(endpoint);
	endpoint_publish_snapshot(endpoint);
}

static void endpoint_snapshot_dtor(void *obj)
{
	struct ast_endpoint_snapshot *snapshot = obj;
	int channel;

	ast_assert(snapshot != NULL);

	for (channel = 0; channel < snapshot->num_channels; channel++) {
		ao2_ref(snapshot->channel_ids[channel], -1);
	}

	ast_string_field_free_memory(snapshot);
}

struct ast_endpoint_snapshot *ast_endpoint_snapshot_create(
	struct ast_endpoint *endpoint)
{
	struct ast_endpoint_snapshot *snapshot;
	int channel_count;
	struct ao2_iterator i;
	void *obj;
	SCOPED_AO2LOCK(lock, endpoint);

	ast_assert(endpoint != NULL);
	ast_assert(!ast_strlen_zero(endpoint->resource));

	channel_count = ao2_container_count(endpoint->channel_ids);

	snapshot = ao2_alloc_options(
		sizeof(*snapshot) + channel_count * sizeof(char *),
		endpoint_snapshot_dtor,
		AO2_ALLOC_OPT_LOCK_NOLOCK);

	if (!snapshot || ast_string_field_init(snapshot, 80) != 0) {
		ao2_cleanup(snapshot);
		return NULL;
	}

	ast_string_field_build(snapshot, id, "%s/%s", endpoint->tech,
		endpoint->resource);
	ast_string_field_set(snapshot, tech, endpoint->tech);
	ast_string_field_set(snapshot, resource, endpoint->resource);

	snapshot->state = endpoint->state;
	snapshot->max_channels = endpoint->max_channels;

	i = ao2_iterator_init(endpoint->channel_ids, 0);
	while ((obj = ao2_iterator_next(&i))) {
		/* The reference is kept so the channel id does not go away until the snapshot is gone */
		snapshot->channel_ids[snapshot->num_channels++] = obj;
	}
	ao2_iterator_destroy(&i);

	return snapshot;
}

static void endpoint_cleanup(void)
{
	ao2_cleanup(endpoints);
	endpoints = NULL;

	ao2_cleanup(tech_endpoints);
	tech_endpoints = NULL;
}

int ast_endpoint_init(void)
{
	ast_register_cleanup(endpoint_cleanup);

	endpoints = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0, ENDPOINT_BUCKETS,
		ast_endpoint_hash_fn, NULL, ast_endpoint_cmp_fn);
	if (!endpoints) {
		return -1;
	}

	tech_endpoints = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0,
		TECH_ENDPOINT_BUCKETS, ast_endpoint_hash_fn, NULL, ast_endpoint_cmp_fn);
	if (!tech_endpoints) {
		return -1;
	}

	return 0;
}