summaryrefslogtreecommitdiff
path: root/res/parking/parking_bridge_features.c
blob: 2770233332b65a2fb1bc212739beddd79f4630d1 (plain)
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
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Jonathan Rose <jrose@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 Parking Bridge DTMF and Interval features
 *
 * \author Jonathan Rose <jrose@digium.com>
 */

#include "asterisk.h"

#include "res_parking.h"
#include "asterisk/utils.h"
#include "asterisk/astobj2.h"
#include "asterisk/logger.h"
#include "asterisk/pbx.h"
#include "asterisk/bridge.h"
#include "asterisk/bridge_internal.h"
#include "asterisk/bridge_channel.h"
#include "asterisk/bridge_features.h"
#include "asterisk/features.h"
#include "asterisk/say.h"
#include "asterisk/datastore.h"
#include "asterisk/stasis.h"
#include "asterisk/module.h"
#include "asterisk/core_local.h"
#include "asterisk/causes.h"

struct parked_subscription_datastore {
	struct stasis_subscription *parked_subscription;
};

struct parked_subscription_data {
	struct transfer_channel_data *transfer_data;
	char *parkee_uuid;
	int hangup_after:1;
	char parker_uuid[0];
};

static void parked_subscription_datastore_destroy(void *data)
{
	struct parked_subscription_datastore *subscription_datastore = data;

	stasis_unsubscribe(subscription_datastore->parked_subscription);
	subscription_datastore->parked_subscription = NULL;

	ast_free(subscription_datastore);
}

static const struct ast_datastore_info parked_subscription_info = {
	.type = "park subscription",
	.destroy = parked_subscription_datastore_destroy,
};

static void wipe_subscription_datastore(struct ast_channel *chan)
{
	struct ast_datastore *datastore;

	ast_channel_lock(chan);

	datastore = ast_channel_datastore_find(chan, &parked_subscription_info, NULL);
	if (datastore) {
		ast_channel_datastore_remove(chan, datastore);
		ast_datastore_free(datastore);
	}
	ast_channel_unlock(chan);
}

static void parker_parked_call_message_response(struct ast_parked_call_payload *message, struct parked_subscription_data *data,
	struct stasis_subscription *sub)
{
	const char *parkee_to_act_on = data->parkee_uuid;
	char saynum_buf[16];
	struct ast_channel_snapshot *parkee_snapshot = message->parkee;
	RAII_VAR(struct ast_channel *, parker, NULL, ast_channel_cleanup);
	RAII_VAR(struct ast_bridge_channel *, bridge_channel, NULL, ao2_cleanup);

	if (strcmp(parkee_to_act_on, parkee_snapshot->uniqueid)) {
		return;
	}

	if (message->event_type != PARKED_CALL && message->event_type != PARKED_CALL_FAILED) {
		/* We only care about these two event types */
		return;
	}

	parker = ast_channel_get_by_name(data->parker_uuid);
	if (!parker) {
		return;
	}

	ast_channel_lock(parker);
	bridge_channel = ast_channel_get_bridge_channel(parker);
	ast_channel_unlock(parker);
	if (!bridge_channel) {
		return;
	}

	/* This subscription callback will block for the duration of the announcement if
	 * parked_subscription_data is tracking a transfer_channel_data struct. */
	if (message->event_type == PARKED_CALL) {
		/* queue the saynum on the bridge channel and hangup */
		snprintf(saynum_buf, sizeof(saynum_buf), "%d %u", data->hangup_after, message->parkingspace);
		if (!data->transfer_data) {
			ast_bridge_channel_queue_playfile(bridge_channel, say_parking_space, saynum_buf, NULL);
		} else {
			ast_bridge_channel_queue_playfile_sync(bridge_channel, say_parking_space, saynum_buf, NULL);
			data->transfer_data->completed = 1;
		}
		wipe_subscription_datastore(parker);
	} else if (message->event_type == PARKED_CALL_FAILED) {
		if (!data->transfer_data) {
			ast_bridge_channel_queue_playfile(bridge_channel, NULL, "pbx-parkingfailed", NULL);
		} else {
			ast_bridge_channel_queue_playfile_sync(bridge_channel, NULL, "pbx-parkingfailed", NULL);
			data->transfer_data->completed = 1;
		}
		wipe_subscription_datastore(parker);
	}
}

static void parker_update_cb(void *data, struct stasis_subscription *sub, struct stasis_message *message)
{
	if (stasis_subscription_final_message(sub, message)) {
		struct parked_subscription_data *ps_data = data;
		ao2_cleanup(ps_data->transfer_data);
		ps_data->transfer_data = NULL;
		ast_free(data);
		return;
	}

	if (stasis_message_type(message) == ast_parked_call_type()) {
		struct ast_parked_call_payload *parked_call_message = stasis_message_data(message);
		parker_parked_call_message_response(parked_call_message, data, sub);
	}
}

static int create_parked_subscription_full(struct ast_channel *chan, const char *parkee_uuid, int hangup_after,
	struct transfer_channel_data *parked_channel_data)
{
	struct ast_datastore *datastore;
	struct parked_subscription_datastore *parked_datastore;
	struct parked_subscription_data *subscription_data;

	char *parker_uuid = ast_strdupa(ast_channel_uniqueid(chan));
	size_t parker_uuid_size = strlen(parker_uuid) + 1;

	/* If there is already a subscription, get rid of it. */
	wipe_subscription_datastore(chan);

	if (!(datastore = ast_datastore_alloc(&parked_subscription_info, NULL))) {
		return -1;
	}

	if (!(parked_datastore = ast_calloc(1, sizeof(*parked_datastore)))) {
		ast_datastore_free(datastore);
		return -1;
	}

	if (!(subscription_data = ast_calloc(1, sizeof(*subscription_data) + parker_uuid_size +
			strlen(parkee_uuid) + 1))) {
		ast_datastore_free(datastore);
		ast_free(parked_datastore);
		return -1;
	}

	if (parked_channel_data) {
		subscription_data->transfer_data = parked_channel_data;
		ao2_ref(parked_channel_data, +1);
	}

	subscription_data->hangup_after = hangup_after;
	subscription_data->parkee_uuid = subscription_data->parker_uuid + parker_uuid_size;
	strcpy(subscription_data->parkee_uuid, parkee_uuid);
	strcpy(subscription_data->parker_uuid, parker_uuid);

	if (!(parked_datastore->parked_subscription = stasis_subscribe_pool(ast_parking_topic(), parker_update_cb, subscription_data))) {
		return -1;
	}

	datastore->data = parked_datastore;

	ast_channel_lock(chan);
	ast_channel_datastore_add(chan, datastore);
	ast_channel_unlock(chan);

	return 0;
}

int create_parked_subscription(struct ast_channel *chan, const char *parkee_uuid, int hangup_after)
{
	return create_parked_subscription_full(chan, parkee_uuid, hangup_after, NULL);
}

/*!
 * \internal
 * \brief Helper function that creates an outgoing channel and returns it immediately. This function is nearly
 *        identical to the dial_transfer function in bridge_basic.c, however it doesn't swap the
 *        local channel and the channel that instigated the park.
 */
static struct ast_channel *park_local_transfer(struct ast_channel *parker, const char *context, const char *exten, struct transfer_channel_data *parked_channel_data)
{
	char destination[AST_MAX_EXTENSION + AST_MAX_CONTEXT + 1];
	struct ast_channel *parkee;
	struct ast_channel *parkee_side_2;
	int cause;

	/* Fill the variable with the extension and context we want to call */
	snprintf(destination, sizeof(destination), "%s@%s", exten, context);

	/* Now we request that chan_local prepare to call the destination */
	parkee = ast_request("Local", ast_channel_nativeformats(parker), NULL, parker, destination,
		&cause);
	if (!parkee) {
		return NULL;
	}

	/* Before we actually dial out let's inherit appropriate information. */
	ast_channel_lock_both(parker, parkee);
	ast_channel_req_accountcodes(parkee, parker, AST_CHANNEL_REQUESTOR_REPLACEMENT);
	ast_channel_parkinglot_set(parkee, ast_channel_parkinglot(parker));
	ast_connected_line_copy_from_caller(ast_channel_connected(parkee), ast_channel_caller(parker));
	ast_channel_inherit_variables(parker, parkee);
	ast_bridge_set_transfer_variables(parkee, ast_channel_name(parker), 0);
	ast_channel_datastore_inherit(parker, parkee);
	ast_channel_unlock(parker);

	parkee_side_2 = ast_local_get_peer(parkee);
	ast_assert(parkee_side_2 != NULL);
	ast_channel_unlock(parkee);

	/* We need to have the parker subscribe to the new local channel before hand. */
	if (create_parked_subscription_full(parker, ast_channel_uniqueid(parkee_side_2), 1, parked_channel_data)) {
		ast_channel_unref(parkee_side_2);
		ast_hangup(parkee);
		return NULL;
	}

	ast_channel_unref(parkee_side_2);

	/* Since the above worked fine now we actually call it and return the channel */
	if (ast_call(parkee, destination, 0)) {
		ast_hangup(parkee);
		return NULL;
	}

	return parkee;
}

/*!
 * \internal
 * \brief Determine if an extension is a parking extension
 */
static int parking_is_exten_park(const char *context, const char *exten)
{
	struct ast_exten *exten_obj;
	struct pbx_find_info info = { .stacklen = 0 }; /* the rest is reset in pbx_find_extension */
	const char *app_at_exten;

	ast_debug(4, "Checking if %s@%s is a parking exten\n", exten, context);
	exten_obj = pbx_find_extension(NULL, NULL, &info, context, exten, 1, NULL, NULL, E_MATCH);
	if (!exten_obj) {
		return 0;
	}

	app_at_exten = ast_get_extension_app(exten_obj);
	if (!app_at_exten || strcasecmp(PARK_APPLICATION, app_at_exten)) {
		return 0;
	}

	return 1;
}

/*!
 * \internal
 * \since 12.0.0
 * \brief Perform a blind transfer to a parking lot
 *
 * In general, most parking features should work to call this function. This will safely
 * park either a channel in the bridge with \ref bridge_channel or will park the entire
 * bridge if more than one channel is in the bridge. It will create the correct data to
 * pass to the \ref AstBridging Bridging API to safely park the channel.
 *
 * \param bridge_channel The bridge_channel representing the channel performing the park
 * \param context The context to blind transfer to
 * \param exten The extension to blind transfer to
 * \param parked_channel_cb Optional callback executed prior to sending the parked channel into the bridge
 * \param parked_channel_data Data for the parked_channel_cb
 *
 * \retval 0 on success
 * \retval non-zero on error
 */
static int parking_blind_transfer_park(struct ast_bridge_channel *bridge_channel,
		const char *context, const char *exten, transfer_channel_cb parked_channel_cb,
		struct transfer_channel_data *parked_channel_data)
{
	RAII_VAR(struct ast_bridge_channel *, other, NULL, ao2_cleanup);
	RAII_VAR(struct ast_channel *, other_chan, NULL, ast_channel_cleanup);

	struct ast_exten *e;
	struct pbx_find_info find_info = { .stacklen = 0 };
	int peer_count;

	if (ast_strlen_zero(context) || ast_strlen_zero(exten)) {
		return -1;
	}

	if (!bridge_channel->in_bridge) {
		return -1;
	}

	if (!parking_is_exten_park(context, exten)) {
		return -1;
	}

	ast_bridge_channel_lock_bridge(bridge_channel);
	peer_count = bridge_channel->bridge->num_channels;
	if (peer_count == 2) {
		other = ast_bridge_channel_peer(bridge_channel);
		ao2_ref(other, +1);
		other_chan = other->chan;
		ast_channel_ref(other_chan);
	}
	ast_bridge_unlock(bridge_channel->bridge);

	if (peer_count < 2) {
		/* There is nothing to do if there is no one to park. */
		return -1;
	}

	/* With a multiparty bridge, we need to do a regular blind transfer. We link the
	 * existing bridge to the parking lot with a Local channel rather than
	 * transferring others. */
	if (peer_count > 2) {
		struct ast_channel *transfer_chan = NULL;

		transfer_chan = park_local_transfer(bridge_channel->chan, context, exten, parked_channel_data);
		if (!transfer_chan) {
			return -1;
		}
		ast_channel_ref(transfer_chan);

		if (parked_channel_cb) {
			parked_channel_cb(transfer_chan, parked_channel_data, AST_BRIDGE_TRANSFER_MULTI_PARTY);
		}

		if (ast_bridge_impart(bridge_channel->bridge, transfer_chan, NULL, NULL,
			AST_BRIDGE_IMPART_CHAN_INDEPENDENT)) {
			ast_hangup(transfer_chan);
			ast_channel_unref(transfer_chan);
			return -1;
		}

		ast_channel_unref(transfer_chan);

		return 0;
	}

	/* Subscribe to park messages with the other channel entering */
	if (create_parked_subscription_full(bridge_channel->chan, ast_channel_uniqueid(other->chan), 1, parked_channel_data)) {
		return -1;
	}

	if (parked_channel_cb) {
		parked_channel_cb(other_chan, parked_channel_data, AST_BRIDGE_TRANSFER_SINGLE_PARTY);
	}

	e = pbx_find_extension(NULL, NULL, &find_info, context, exten, 1, NULL, NULL, E_MATCH);

	/* Write the park frame with the intended recipient and other data out to the bridge. */
	ast_bridge_channel_write_park(bridge_channel,
		ast_channel_uniqueid(other_chan),
		ast_channel_uniqueid(bridge_channel->chan),
		e ? ast_get_extension_app_data(e) : NULL);

	return 0;
}

/*!
 * \internal
 * \since 12.0.0
 * \brief Perform a direct park on a channel in a bridge
 *
 * \note This will be called from within the \ref AstBridging Bridging API
 *
 * \param bridge_channel The bridge_channel representing the channel to be parked
 * \param uuid_parkee The UUID of the channel being parked
 * \param uuid_parker The UUID of the channel performing the park
 * \param app_data Application parseable data to pass to the parking application
 */
static int parking_park_bridge_channel(struct ast_bridge_channel *bridge_channel, const char *uuid_parkee, const char *uuid_parker, const char *app_data)
{
	RAII_VAR(struct ast_bridge *, parking_bridge, NULL, ao2_cleanup);
	RAII_VAR(struct ast_bridge *, original_bridge, NULL, ao2_cleanup);
	RAII_VAR(struct ast_channel *, parker, NULL, ao2_cleanup);

	if (strcmp(ast_channel_uniqueid(bridge_channel->chan), uuid_parkee)) {
		/* We aren't the parkee, so ignore this action. */
		return -1;
	}

	parker = ast_channel_get_by_name(uuid_parker);

	if (!parker) {
		ast_log(LOG_NOTICE, "Channel with uuid %s left before we could start parking the call. Parking canceled.\n", uuid_parker);
		publish_parked_call_failure(bridge_channel->chan);
		return -1;
	}

	if (!(parking_bridge = park_application_setup(bridge_channel->chan, parker, app_data, NULL))) {
		publish_parked_call_failure(bridge_channel->chan);
		return -1;
	}

	ast_bridge_set_transfer_variables(bridge_channel->chan, ast_channel_name(parker), 0);

	/* bridge_channel must be locked so we can get a reference to the bridge it is currently on */
	ao2_lock(bridge_channel);

	original_bridge = bridge_channel->bridge;
	if (!original_bridge) {
		ao2_unlock(bridge_channel);
		publish_parked_call_failure(bridge_channel->chan);
		return -1;
	}

	ao2_ref(original_bridge, +1); /* Cleaned by RAII_VAR */

	ao2_unlock(bridge_channel);

	if (ast_bridge_move(parking_bridge, original_bridge, bridge_channel->chan, NULL, 1)) {
		ast_log(LOG_ERROR, "Failed to move %s into the parking bridge.\n",
			ast_channel_name(bridge_channel->chan));
		return -1;
	}

	return 0;
}

/*!
 * \internal
 * \since 12.0.0
 * \brief Park a call
 *
 * \param parker The bridge_channel parking the call
 * \param exten Optional. The extension where the call was parked.
 * \param length Optional. If \c exten is specified, the length of the buffer.
 *
 * \note This will determine the context and extension to park the channel based on
 * the configuration of the \ref ast_channel associated with \ref parker. It will then
 * park either the channel or the entire bridge.
 *
 * \retval 0 on success
 * \retval -1 on error
 */
static int parking_park_call(struct ast_bridge_channel *parker, char *exten, size_t length)
{
	RAII_VAR(struct parking_lot *, lot, NULL, ao2_cleanup);
	const char *lot_name;

	ast_channel_lock(parker->chan);
	lot_name = ast_strdupa(find_channel_parking_lot_name(parker->chan));
	ast_channel_unlock(parker->chan);

	lot = parking_lot_find_by_name(lot_name);
	if (!lot) {
		lot = parking_create_dynamic_lot(lot_name, parker->chan);
	}
	if (!lot) {
		ast_log(AST_LOG_WARNING, "Cannot Park %s: lot %s unknown\n",
			ast_channel_name(parker->chan), lot_name);
		return -1;
	}

	if (exten) {
		ast_copy_string(exten, lot->cfg->parkext, length);
	}
	return parking_blind_transfer_park(parker, lot->cfg->parking_con, lot->cfg->parkext, NULL, NULL);
}

static int feature_park_call(struct ast_bridge_channel *bridge_channel, void *hook_pvt)
{
	SCOPED_MODULE_USE(AST_MODULE_SELF);

	parking_park_call(bridge_channel, NULL, 0);
	return 0;
}

/*!
 * \internal
 * \brief Setup the caller features for when that channel is dialed.
 * \since 12.0.0
 *
 * \param chan Parked channel leaving the parking lot.
 * \param cfg Parking lot configuration.
 *
 * \return Nothing
 */
static void parking_timeout_set_caller_features(struct ast_channel *chan, struct parking_lot_cfg *cfg)
{
	char features[5];
	char *pos;

	/*
	 * We are setting the callee Dial flag values because in the
	 * timeout case, the caller is who is being called back.
	 */
	pos = features;
	if (cfg->parkedcalltransfers & AST_FEATURE_FLAG_BYCALLER) {
		*pos++ = 't';
	}
	if (cfg->parkedcallreparking & AST_FEATURE_FLAG_BYCALLER) {
		*pos++ = 'k';
	}
	if (cfg->parkedcallhangup & AST_FEATURE_FLAG_BYCALLER) {
		*pos++ = 'h';
	}
	if (cfg->parkedcallrecording & AST_FEATURE_FLAG_BYCALLER) {
		*pos++ = 'x';
	}
	*pos = '\0';

	pbx_builtin_setvar_helper(chan, "BRIDGE_FEATURES", features);
}

/*! \internal
 * \brief Interval hook. Pulls a parked call from the parking bridge after the timeout is passed and sets the resolution to timeout.
 *
 * \param bridge_channel bridge channel this interval hook is being executed on
 * \param hook_pvt A pointer to the parked_user struct associated with the channel is stuffed in here
 */
static int parking_duration_callback(struct ast_bridge_channel *bridge_channel, void *hook_pvt)
{
	struct parked_user *user = hook_pvt;
	struct ast_channel *chan = user->chan;
	struct ast_context *park_dial_context;
	const char *dial_string;
	char *dial_string_flat;
	char parking_space[AST_MAX_EXTENSION];

	char returnexten[AST_MAX_EXTENSION];
	char *duplicate_returnexten;
	struct ast_exten *existing_exten;
	struct pbx_find_info pbx_finder = { .stacklen = 0 }; /* The rest is reset in pbx_find_extension */


	/* We are still in the bridge, so it's possible for other stuff to mess with the parked call before we leave the bridge
	   to deal with this, lock the parked user, check and set resolution. */
	ao2_lock(user);
	if (user->resolution != PARK_UNSET) {
		/* Abandon timeout since something else has resolved the parked user before we got to it. */
		ao2_unlock(user);
		return -1;
	}
	user->resolution = PARK_TIMEOUT;
	ao2_unlock(user);

	ast_bridge_channel_leave_bridge(bridge_channel, BRIDGE_CHANNEL_STATE_END_NO_DISSOLVE,
		AST_CAUSE_NORMAL_CLEARING);

	dial_string = user->parker_dial_string;
	dial_string_flat = ast_strdupa(dial_string);
	flatten_dial_string(dial_string_flat);

	/* Set parking timeout channel variables */
	snprintf(parking_space, sizeof(parking_space), "%d", user->parking_space);
	ast_channel_lock(chan);
	ast_channel_stage_snapshot(chan);
	pbx_builtin_setvar_helper(chan, "PARKING_SPACE", parking_space);
	pbx_builtin_setvar_helper(chan, "PARKINGSLOT", parking_space); /* Deprecated version of PARKING_SPACE */
	pbx_builtin_setvar_helper(chan, "PARKEDLOT", user->lot->name);
	pbx_builtin_setvar_helper(chan, "PARKER", dial_string);
	pbx_builtin_setvar_helper(chan, "PARKER_FLAT", dial_string_flat);
	parking_timeout_set_caller_features(chan, user->lot->cfg);
	ast_channel_stage_snapshot_done(chan);
	ast_channel_unlock(chan);

	/* Dialplan generation for park-dial extensions */

	if (ast_wrlock_contexts()) {
		ast_log(LOG_ERROR, "Failed to lock the contexts list. Can't add the park-dial extension.\n");
		return -1;
	}

	if (!(park_dial_context = ast_context_find_or_create(NULL, NULL, PARK_DIAL_CONTEXT, BASE_REGISTRAR))) {
		ast_log(LOG_ERROR, "Parking dial context '%s' does not exist and unable to create\n", PARK_DIAL_CONTEXT);
		if (ast_unlock_contexts()) {
			ast_assert(0);
		}
		goto abandon_extension_creation;
	}

	if (ast_wrlock_context(park_dial_context)) {
		ast_log(LOG_ERROR, "failed to obtain write lock on context '%s'\n", PARK_DIAL_CONTEXT);
		if (ast_unlock_contexts()) {
			ast_assert(0);
		}
		goto abandon_extension_creation;
	}

	if (ast_unlock_contexts()) {
		ast_assert(0);
	}

	snprintf(returnexten, sizeof(returnexten), "%s,%u", dial_string,
		user->lot->cfg->comebackdialtime);

	duplicate_returnexten = ast_strdup(returnexten);
	if (!duplicate_returnexten) {
		ast_log(LOG_ERROR, "Failed to create parking redial parker extension %s@%s - Dial(%s)\n",
			dial_string_flat, PARK_DIAL_CONTEXT, returnexten);
	}

	/* If an extension already exists here because we registered it for another parked call timing out, then we may overwrite it. */
	if ((existing_exten = pbx_find_extension(NULL, NULL, &pbx_finder, PARK_DIAL_CONTEXT, dial_string_flat, 1, NULL, NULL, E_MATCH)) &&
	    (strcmp(ast_get_extension_registrar(existing_exten), BASE_REGISTRAR))) {
		ast_debug(3, "An extension for '%s@%s' was already registered by another registrar '%s'\n",
			dial_string_flat, PARK_DIAL_CONTEXT, ast_get_extension_registrar(existing_exten));
	} else if (ast_add_extension2_nolock(park_dial_context, 1, dial_string_flat, 1, NULL, NULL,
			"Dial", duplicate_returnexten, ast_free_ptr, BASE_REGISTRAR, NULL, 0)) {
			ast_free(duplicate_returnexten);
		ast_log(LOG_ERROR, "Failed to create parking redial parker extension %s@%s - Dial(%s)\n",
			dial_string_flat, PARK_DIAL_CONTEXT, returnexten);
	}

	if (ast_unlock_context(park_dial_context)) {
		ast_assert(0);
	}

abandon_extension_creation:

	/* async_goto the proper PBX destination - this should happen when we come out of the bridge */
	if (!ast_strlen_zero(user->comeback)) {
		ast_async_parseable_goto(chan, user->comeback);
	} else {
		comeback_goto(user, user->lot);
	}

	return -1;
}

void say_parking_space(struct ast_bridge_channel *bridge_channel, const char *payload)
{
	unsigned int numeric_value;
	unsigned int hangup_after;

	if (sscanf(payload, "%u %u", &hangup_after, &numeric_value) != 2) {
		/* If say_parking_space is called with a non-numeric string, we have a problem. */
		ast_assert(0);
		ast_bridge_channel_leave_bridge(bridge_channel,
			BRIDGE_CHANNEL_STATE_END_NO_DISSOLVE, AST_CAUSE_NORMAL_CLEARING);
		return;
	}

	ast_say_digits(bridge_channel->chan, numeric_value, "",
		ast_channel_language(bridge_channel->chan));

	if (hangup_after) {
		ast_bridge_channel_leave_bridge(bridge_channel,
			BRIDGE_CHANNEL_STATE_END_NO_DISSOLVE, AST_CAUSE_NORMAL_CLEARING);
	}
}

void parking_set_duration(struct ast_bridge_features *features, struct parked_user *user)
{
	unsigned int time_limit;

	time_limit = user->time_limit * 1000;

	if (!time_limit) {
		/* There is no duration limit that we need to apply. */
		return;
	}

	/* If the time limit has already been passed, set a really low time limit so we can kick them out immediately. */
	time_limit = ast_remaining_ms(user->start, time_limit);
	if (time_limit <= 0) {
		time_limit = 1;
	}

	/* The interval hook is going to need a reference to the parked_user */
	ao2_ref(user, +1);

	if (ast_bridge_interval_hook(features, 0, time_limit,
		parking_duration_callback, user, __ao2_cleanup, AST_BRIDGE_HOOK_REMOVE_ON_PULL)) {
		ast_log(LOG_ERROR, "Failed to apply duration limit to the parked call.\n");
		ao2_ref(user, -1);
	}
}

struct ast_parking_bridge_feature_fn_table parking_provider = {
	.module_version = PARKING_MODULE_VERSION,
	.module_name = __FILE__,
	.parking_is_exten_park = parking_is_exten_park,
	.parking_blind_transfer_park = parking_blind_transfer_park,
	.parking_park_bridge_channel = parking_park_bridge_channel,
	.parking_park_call = parking_park_call,
};

void unload_parking_bridge_features(void)
{
	ast_bridge_features_unregister(AST_BRIDGE_BUILTIN_PARKCALL);
	ast_parking_unregister_bridge_features(parking_provider.module_name);
}

int load_parking_bridge_features(void)
{
	parking_provider.module = AST_MODULE_SELF;

	if (ast_parking_register_bridge_features(&parking_provider)) {
		return -1;
	}

	if (ast_bridge_features_register(AST_BRIDGE_BUILTIN_PARKCALL, feature_park_call, NULL)) {
		return -1;
	}

	return 0;
}