aboutsummaryrefslogtreecommitdiffstats
path: root/channels/chan_local.c
blob: 9181af08d10632d9a0b7e1d2f68b922b35d8c037 (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
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@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
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * \brief Local Proxy Channel
 * 
 * \ingroup channel_drivers
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include <fcntl.h>
#include <sys/signal.h>

#include "asterisk/lock.h"
#include "asterisk/channel.h"
#include "asterisk/config.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/sched.h"
#include "asterisk/io.h"
#include "asterisk/rtp.h"
#include "asterisk/acl.h"
#include "asterisk/callerid.h"
#include "asterisk/file.h"
#include "asterisk/cli.h"
#include "asterisk/app.h"
#include "asterisk/musiconhold.h"
#include "asterisk/manager.h"
#include "asterisk/stringfields.h"
#include "asterisk/devicestate.h"
#include "asterisk/astobj2.h"

static const char tdesc[] = "Local Proxy Channel Driver";

#define IS_OUTBOUND(a,b) (a == b->chan ? 1 : 0)
/* right now we are treating the locals astobj2 container as a
 * list.  If there is ever a reason to make this more efficient
 * increasing the bucket size would help. */
static const int BUCKET_SIZE = 1;

static struct ao2_container *locals;

static struct ast_jb_conf g_jb_conf = {
	.flags = 0,
	.max_size = -1,
	.resync_threshold = -1,
	.impl = "",
	.target_extra = -1,
};

static struct ast_channel *local_request(const char *type, int format, void *data, int *cause);
static int local_digit_begin(struct ast_channel *ast, char digit);
static int local_digit_end(struct ast_channel *ast, char digit, unsigned int duration);
static int local_call(struct ast_channel *ast, char *dest, int timeout);
static int local_hangup(struct ast_channel *ast);
static int local_answer(struct ast_channel *ast);
static struct ast_frame *local_read(struct ast_channel *ast);
static int local_write(struct ast_channel *ast, struct ast_frame *f);
static int local_indicate(struct ast_channel *ast, int condition, const void *data, size_t datalen);
static int local_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
static int local_sendhtml(struct ast_channel *ast, int subclass, const char *data, int datalen);
static int local_sendtext(struct ast_channel *ast, const char *text);
static int local_devicestate(void *data);
static struct ast_channel *local_bridgedchannel(struct ast_channel *chan, struct ast_channel *bridge);
static int local_queryoption(struct ast_channel *ast, int option, void *data, int *datalen);
static int local_setoption(struct ast_channel *chan, int option, void *data, int datalen);

/* PBX interface structure for channel registration */
static const struct ast_channel_tech local_tech = {
	.type = "Local",
	.description = tdesc,
	.capabilities = -1,
	.requester = local_request,
	.send_digit_begin = local_digit_begin,
	.send_digit_end = local_digit_end,
	.call = local_call,
	.hangup = local_hangup,
	.answer = local_answer,
	.read = local_read,
	.write = local_write,
	.write_video = local_write,
	.exception = local_read,
	.indicate = local_indicate,
	.fixup = local_fixup,
	.send_html = local_sendhtml,
	.send_text = local_sendtext,
	.devicestate = local_devicestate,
	.bridged_channel = local_bridgedchannel,
	.queryoption = local_queryoption,
	.setoption = local_setoption,
};

struct local_pvt {
	unsigned int flags;                     /* Private flags */
	char context[AST_MAX_CONTEXT];		/* Context to call */
	char exten[AST_MAX_EXTENSION];		/* Extension to call */
	int reqformat;				/* Requested format */
	struct ast_jb_conf jb_conf;		/*!< jitterbuffer configuration for this local channel */
	struct ast_channel *owner;		/* Master Channel - Bridging happens here */
	struct ast_channel *chan;		/* Outbound channel - PBX is run here */
	struct ast_module_user *u_owner;	/*! reference to keep the module loaded while in use */
	struct ast_module_user *u_chan;		/*! reference to keep the module loaded while in use */
	AST_LIST_ENTRY(local_pvt) list;		/* Next entity */
};

#define LOCAL_ALREADY_MASQED  (1 << 0) /*!< Already masqueraded */
#define LOCAL_LAUNCHED_PBX    (1 << 1) /*!< PBX was launched */
#define LOCAL_NO_OPTIMIZATION (1 << 2) /*!< Do not optimize using masquerading */
#define LOCAL_BRIDGE          (1 << 3) /*!< Report back the "true" channel as being bridged to */
#define LOCAL_MOH_PASSTHRU    (1 << 4) /*!< Pass through music on hold start/stop frames */

static int local_setoption(struct ast_channel *chan, int option, void * data, int datalen)
{
	int res;
	struct local_pvt *p;
	struct ast_channel *otherchan;
	ast_chan_write_info_t *write_info;

	if (option != AST_OPTION_CHANNEL_WRITE) {
		return -1;
	}

	write_info = data;

	if (write_info->version != AST_CHAN_WRITE_INFO_T_VERSION) {
		ast_log(LOG_ERROR, "The chan_write_info_t type has changed, and this channel hasn't been updated!\n");
		return -1;
	}


startover:
	ast_channel_lock(chan);

	p = chan->tech_pvt;
	if (!p) {
		ast_channel_unlock(chan);
		ast_log(LOG_WARNING, "Could not update other side of %s, local_pvt went away.\n", chan->name);
		return -1;
	}

	while (ao2_trylock(p)) {
		ast_channel_unlock(chan);
		sched_yield();
		ast_channel_lock(chan);
		p = chan->tech_pvt;
		if (!p) {
			ast_channel_unlock(chan);
			ast_log(LOG_WARNING, "Could not update other side of %s, local_pvt went away.\n", chan->name);
			return -1;
		}
	}

	otherchan = (write_info->chan == p->owner) ? p->chan : p->owner;

	if (!otherchan || otherchan == write_info->chan) {
		ao2_unlock(p);
		ast_channel_unlock(chan);
		ast_log(LOG_WARNING, "Could not update other side of %s, other side went away.\n", chan->name);
		return 0;
	}

	if (ast_channel_trylock(otherchan)) {
		ao2_unlock(p);
		ast_channel_unlock(chan);
		goto startover;
	}

	res = write_info->write_fn(otherchan, write_info->function, write_info->data, write_info->value);

	ast_channel_unlock(otherchan);
	ao2_unlock(p);
	ast_channel_unlock(chan);

	return res;
}

/*! \brief Adds devicestate to local channels */
static int local_devicestate(void *data)
{
	char *exten = ast_strdupa(data);
	char *context = NULL, *opts = NULL;
	int res;
	struct local_pvt *lp;
	struct ao2_iterator it;

	if (!(context = strchr(exten, '@'))) {
		ast_log(LOG_WARNING, "Someone used Local/%s somewhere without a @context. This is bad.\n", exten);
		return AST_DEVICE_INVALID;	
	}

	*context++ = '\0';

	/* Strip options if they exist */
	if ((opts = strchr(context, '/')))
		*opts = '\0';

	ast_debug(3, "Checking if extension %s@%s exists (devicestate)\n", exten, context);

	res = ast_exists_extension(NULL, context, exten, 1, NULL);
	if (!res)		
		return AST_DEVICE_INVALID;
	
	res = AST_DEVICE_NOT_INUSE;

	it = ao2_iterator_init(locals, 0);
	while ((lp = ao2_iterator_next(&it))) {
		if (!strcmp(exten, lp->exten) && !strcmp(context, lp->context) && lp->owner) {
			res = AST_DEVICE_INUSE;
			ao2_ref(lp, -1);
			break;
		}
		ao2_ref(lp, -1);
	}
	ao2_iterator_destroy(&it);

	return res;
}

/*! \brief Return the bridged channel of a Local channel */
static struct ast_channel *local_bridgedchannel(struct ast_channel *chan, struct ast_channel *bridge)
{
	struct local_pvt *p = bridge->tech_pvt;
	struct ast_channel *bridged = bridge;

	if (!p) {
		ast_debug(1, "Asked for bridged channel on '%s'/'%s', returning <none>\n",
			chan->name, bridge->name);
		return NULL;
	}

	ao2_lock(p);

	if (ast_test_flag(p, LOCAL_BRIDGE)) {
		/* Find the opposite channel */
		bridged = (bridge == p->owner ? p->chan : p->owner);
		
		/* Now see if the opposite channel is bridged to anything */
		if (!bridged) {
			bridged = bridge;
		} else if (bridged->_bridge) {
			bridged = bridged->_bridge;
		}
	}

	ao2_unlock(p);

	return bridged;
}

static int local_queryoption(struct ast_channel *ast, int option, void *data, int *datalen)
{
	struct local_pvt *p = ast->tech_pvt;
	struct ast_channel *chan, *bridged;
	int res;

	if (!p) {
		return -1;
	}

	if (option != AST_OPTION_T38_STATE) {
		/* AST_OPTION_T38_STATE is the only supported option at this time */
		return -1;
	}

	ao2_lock(p);
	chan = IS_OUTBOUND(ast, p) ? p->owner : p->chan;

try_again:
	if (!chan) {
		ao2_unlock(p);
		return -1;
	}

	if (ast_channel_trylock(chan)) {
		ao2_unlock(p);
		sched_yield();
		ao2_lock(p);
		chan = IS_OUTBOUND(ast, p) ? p->owner : p->chan;
		goto try_again;
	}

	bridged = ast_bridged_channel(chan);
	if (!bridged) {
		/* can't query channel unless we are bridged */
		ao2_unlock(p);
		ast_channel_unlock(chan);
		return -1;
	}

	if (ast_channel_trylock(bridged)) {
		ast_channel_unlock(chan);
		ao2_unlock(p);
		sched_yield();
		ao2_lock(p);
		chan = IS_OUTBOUND(ast, p) ? p->owner : p->chan;
		goto try_again;
	}

	res = ast_channel_queryoption(bridged, option, data, datalen, 0);
	ao2_unlock(p);
	ast_channel_unlock(chan);
	ast_channel_unlock(bridged);
	return res;
}

/*! \brief queue a frame on a to either the p->owner or p->chan
 *
 * \note the local_pvt MUST have it's ref count bumped before entering this function and
 * decremented after this function is called.  This is a side effect of the deadlock
 * avoidance that is necessary to lock 2 channels and a tech_pvt.  Without a ref counted
 * local_pvt, it is impossible to guarantee it will not be destroyed by another thread
 * during deadlock avoidance.
 */
static int local_queue_frame(struct local_pvt *p, int isoutbound, struct ast_frame *f, 
	struct ast_channel *us, int us_locked)
{
	struct ast_channel *other = NULL;

	/* Recalculate outbound channel */
	other = isoutbound ? p->owner : p->chan;

	if (!other) {
		return 0;
	}

	/* do not queue frame if generator is on both local channels */
	if (us && us->generator && other->generator) {
		return 0;
	}

	/* Ensure that we have both channels locked */
	while (other && ast_channel_trylock(other)) {
		int res;
		if ((res = ao2_unlock(p))) {
			ast_log(LOG_ERROR, "chan_local bug! '&p->lock' was not locked when entering local_queue_frame! (%s)\n", strerror(res));
			return -1;
		}
		if (us && us_locked) {
			do {
				CHANNEL_DEADLOCK_AVOIDANCE(us);
			} while (ao2_trylock(p));
		} else {
			usleep(1);
			ao2_lock(p);
		}
		other = isoutbound ? p->owner : p->chan;
	}

	if (other) {
		if (f->frametype == AST_FRAME_CONTROL && f->subclass == AST_CONTROL_RINGING) {
			ast_setstate(other, AST_STATE_RINGING);
		}
		ast_queue_frame(other, f);
		ast_channel_unlock(other);
	}

	return 0;
}

static int local_answer(struct ast_channel *ast)
{
	struct local_pvt *p = ast->tech_pvt;
	int isoutbound;
	int res = -1;

	if (!p)
		return -1;

	ao2_lock(p);
	ao2_ref(p, 1);
	isoutbound = IS_OUTBOUND(ast, p);
	if (isoutbound) {
		/* Pass along answer since somebody answered us */
		struct ast_frame answer = { AST_FRAME_CONTROL, AST_CONTROL_ANSWER };
		res = local_queue_frame(p, isoutbound, &answer, ast, 1);
	} else {
		ast_log(LOG_WARNING, "Huh?  Local is being asked to answer?\n");
	}
	ao2_unlock(p);
	ao2_ref(p, -1);
	return res;
}

/*!
 * \internal
 * \note This function assumes that we're only called from the "outbound" local channel side
 */
static void check_bridge(struct local_pvt *p)
{
	struct ast_channel_monitor *tmp;
	if (ast_test_flag(p, LOCAL_ALREADY_MASQED) || ast_test_flag(p, LOCAL_NO_OPTIMIZATION) || !p->chan || !p->owner || (p->chan->_bridge != ast_bridged_channel(p->chan)))
		return;

	/* only do the masquerade if we are being called on the outbound channel,
	   if it has been bridged to another channel and if there are no pending
	   frames on the owner channel (because they would be transferred to the
	   outbound channel during the masquerade)
	*/
	if (p->chan->_bridge /* Not ast_bridged_channel!  Only go one step! */ && AST_LIST_EMPTY(&p->owner->readq)) {
		/* Masquerade bridged channel into owner */
		/* Lock everything we need, one by one, and give up if
		   we can't get everything.  Remember, we'll get another
		   chance in just a little bit */
		if (!ast_channel_trylock(p->chan->_bridge)) {
			if (!ast_check_hangup(p->chan->_bridge)) {
				if (!ast_channel_trylock(p->owner)) {
					if (!ast_check_hangup(p->owner)) {
						if (p->owner->monitor && !p->chan->_bridge->monitor) {
							/* If a local channel is being monitored, we don't want a masquerade
							 * to cause the monitor to go away. Since the masquerade swaps the monitors,
							 * pre-swapping the monitors before the masquerade will ensure that the monitor
							 * ends up where it is expected.
							 */
							tmp = p->owner->monitor;
							p->owner->monitor = p->chan->_bridge->monitor;
							p->chan->_bridge->monitor = tmp;
						}
						if (p->chan->audiohooks) {
							struct ast_audiohook_list *audiohooks_swapper;
							audiohooks_swapper = p->chan->audiohooks;
							p->chan->audiohooks = p->owner->audiohooks;
							p->owner->audiohooks = audiohooks_swapper;
						}

						/* If any Caller ID was set, preserve it after masquerade like above. We must check
						 * to see if Caller ID was set because otherwise we'll mistakingly copy info not
						 * set from the dialplan and will overwrite the real channel Caller ID. The reason
						 * for this whole preswapping action is because the Caller ID is set on the channel
						 * thread (which is the to be masqueraded away local channel) before both local
						 * channels are optimized away.
						 */
						if (p->owner->cid.cid_dnid || p->owner->cid.cid_num ||
							p->owner->cid.cid_name || p->owner->cid.cid_ani ||
							p->owner->cid.cid_rdnis || p->owner->cid.cid_pres ||  
							p->owner->cid.cid_ani2 || p->owner->cid.cid_ton ||  
							p->owner->cid.cid_tns) {

							struct ast_callerid tmpcid;
							tmpcid = p->owner->cid;
							p->owner->cid = p->chan->_bridge->cid;
							p->chan->_bridge->cid = tmpcid;
						}

						ast_app_group_update(p->chan, p->owner);
						ast_channel_masquerade(p->owner, p->chan->_bridge);
						ast_set_flag(p, LOCAL_ALREADY_MASQED);
					}
					ast_channel_unlock(p->owner);
				}
				ast_channel_unlock(p->chan->_bridge);
			}
		}
	}
}

static struct ast_frame  *local_read(struct ast_channel *ast)
{
	return &ast_null_frame;
}

static int local_write(struct ast_channel *ast, struct ast_frame *f)
{
	struct local_pvt *p = ast->tech_pvt;
	int res = -1;
	int isoutbound;

	if (!p)
		return -1;

	/* Just queue for delivery to the other side */
	ao2_lock(p);
	ao2_ref(p, 1); /* ref for local_queue_frame */
	isoutbound = IS_OUTBOUND(ast, p);
	if (isoutbound && f && (f->frametype == AST_FRAME_VOICE || f->frametype == AST_FRAME_VIDEO))
		check_bridge(p);
	if (!ast_test_flag(p, LOCAL_ALREADY_MASQED))
		res = local_queue_frame(p, isoutbound, f, ast, 1);
	else {
		ast_debug(1, "Not posting to queue since already masked on '%s'\n", ast->name);
		res = 0;
	}
	ao2_unlock(p);
	ao2_ref(p, -1);

	return res;
}

static int local_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
{
	struct local_pvt *p = newchan->tech_pvt;

	if (!p)
		return -1;

	ao2_lock(p);

	if ((p->owner != oldchan) && (p->chan != oldchan)) {
		ast_log(LOG_WARNING, "Old channel wasn't %p but was %p/%p\n", oldchan, p->owner, p->chan);
		ao2_unlock(p);
		return -1;
	}
	if (p->owner == oldchan)
		p->owner = newchan;
	else
		p->chan = newchan;

	/* Do not let a masquerade cause a Local channel to be bridged to itself! */
	if (!ast_check_hangup(newchan) && (p->owner->_bridge == p->chan || p->chan->_bridge == p->owner)) {
		ast_log(LOG_WARNING, "You can not bridge a Local channel to itself!\n");
		ao2_unlock(p);
		ast_queue_hangup(newchan);
		return -1;
	}

	ao2_unlock(p);
	return 0;
}

static int local_indicate(struct ast_channel *ast, int condition, const void *data, size_t datalen)
{
	struct local_pvt *p = ast->tech_pvt;
	int res = 0;
	struct ast_frame f = { AST_FRAME_CONTROL, };
	int isoutbound;

	if (!p)
		return -1;

	ao2_ref(p, 1); /* ref for local_queue_frame */

	/* If this is an MOH hold or unhold, do it on the Local channel versus real channel */
	if (!ast_test_flag(p, LOCAL_MOH_PASSTHRU) && condition == AST_CONTROL_HOLD) {
		ast_moh_start(ast, data, NULL);
	} else if (!ast_test_flag(p, LOCAL_MOH_PASSTHRU) && condition == AST_CONTROL_UNHOLD) {
		ast_moh_stop(ast);
	} else {
		/* Queue up a frame representing the indication as a control frame */
		ao2_lock(p);
		isoutbound = IS_OUTBOUND(ast, p);
		f.subclass = condition;
		f.data.ptr = (void*)data;
		f.datalen = datalen;
		res = local_queue_frame(p, isoutbound, &f, ast, 1);
		ao2_unlock(p);
	}

	ao2_ref(p, -1);
	return res;
}

static int local_digit_begin(struct ast_channel *ast, char digit)
{
	struct local_pvt *p = ast->tech_pvt;
	int res = -1;
	struct ast_frame f = { AST_FRAME_DTMF_BEGIN, };
	int isoutbound;

	if (!p)
		return -1;

	ao2_ref(p, 1); /* ref for local_queue_frame */
	ao2_lock(p);
	isoutbound = IS_OUTBOUND(ast, p);
	f.subclass = digit;
	res = local_queue_frame(p, isoutbound, &f, ast, 0);
	ao2_unlock(p);
	ao2_ref(p, -1);

	return res;
}

static int local_digit_end(struct ast_channel *ast, char digit, unsigned int duration)
{
	struct local_pvt *p = ast->tech_pvt;
	int res = -1;
	struct ast_frame f = { AST_FRAME_DTMF_END, };
	int isoutbound;

	if (!p)
		return -1;

	ao2_lock(p);
	ao2_ref(p, 1); /* ref for local_queue_frame */
	isoutbound = IS_OUTBOUND(ast, p);
	f.subclass = digit;
	f.len = duration;
	res = local_queue_frame(p, isoutbound, &f, ast, 0);
	ao2_unlock(p);
	ao2_ref(p, -1);

	return res;
}

static int local_sendtext(struct ast_channel *ast, const char *text)
{
	struct local_pvt *p = ast->tech_pvt;
	int res = -1;
	struct ast_frame f = { AST_FRAME_TEXT, };
	int isoutbound;

	if (!p)
		return -1;

	ao2_lock(p);
	ao2_ref(p, 1); /* ref for local_queue_frame */
	isoutbound = IS_OUTBOUND(ast, p);
	f.data.ptr = (char *) text;
	f.datalen = strlen(text) + 1;
	res = local_queue_frame(p, isoutbound, &f, ast, 0);
	ao2_unlock(p);
	ao2_ref(p, -1);
	return res;
}

static int local_sendhtml(struct ast_channel *ast, int subclass, const char *data, int datalen)
{
	struct local_pvt *p = ast->tech_pvt;
	int res = -1;
	struct ast_frame f = { AST_FRAME_HTML, };
	int isoutbound;

	if (!p)
		return -1;
	
	ao2_lock(p);
	ao2_ref(p, 1); /* ref for local_queue_frame */
	isoutbound = IS_OUTBOUND(ast, p);
	f.subclass = subclass;
	f.data.ptr = (char *)data;
	f.datalen = datalen;
	res = local_queue_frame(p, isoutbound, &f, ast, 0);
	ao2_unlock(p);
	ao2_ref(p, -1);
	return res;
}

/*! \brief Initiate new call, part of PBX interface 
 * 	dest is the dial string */
static int local_call(struct ast_channel *ast, char *dest, int timeout)
{
	struct local_pvt *p = ast->tech_pvt;
	int res = 0;
	struct ast_var_t *varptr = NULL, *new;
	size_t len, namelen;

	if (!p)
		return -1;

	ao2_lock(p);

	/*
	 * Note that cid_num and cid_name aren't passed in the ast_channel_alloc
	 * call, so it's done here instead.
	 */
	p->chan->cid.cid_dnid = ast_strdup(p->owner->cid.cid_dnid);
	p->chan->cid.cid_num = ast_strdup(p->owner->cid.cid_num);
	p->chan->cid.cid_name = ast_strdup(p->owner->cid.cid_name);
	p->chan->cid.cid_rdnis = ast_strdup(p->owner->cid.cid_rdnis);
	p->chan->cid.cid_ani = ast_strdup(p->owner->cid.cid_ani);
	p->chan->cid.cid_pres = p->owner->cid.cid_pres;
	p->chan->cid.cid_ani2 = p->owner->cid.cid_ani2;
	p->chan->cid.cid_ton = p->owner->cid.cid_ton;
	p->chan->cid.cid_tns = p->owner->cid.cid_tns;
	ast_string_field_set(p->chan, language, p->owner->language);
	ast_string_field_set(p->chan, accountcode, p->owner->accountcode);
	ast_string_field_set(p->chan, musicclass, p->owner->musicclass);
	ast_cdr_update(p->chan);
	p->chan->cdrflags = p->owner->cdrflags;

	/* Make sure we inherit the ANSWERED_ELSEWHERE flag if it's set on the queue/dial call request in the dialplan */
	if (ast_test_flag(ast, AST_FLAG_ANSWERED_ELSEWHERE)) {
		ast_set_flag(p->chan, AST_FLAG_ANSWERED_ELSEWHERE);
	}

	/* copy the channel variables from the incoming channel to the outgoing channel */
	/* Note that due to certain assumptions, they MUST be in the same order */
	AST_LIST_TRAVERSE(&p->owner->varshead, varptr, entries) {
		namelen = strlen(varptr->name);
		len = sizeof(struct ast_var_t) + namelen + strlen(varptr->value) + 2;
		if ((new = ast_calloc(1, len))) {
			memcpy(new, varptr, len);
			new->value = &(new->name[0]) + namelen + 1;
			AST_LIST_INSERT_TAIL(&p->chan->varshead, new, entries);
		}
	}
	ast_channel_datastore_inherit(p->owner, p->chan);

	if (!ast_exists_extension(p->chan, p->chan->context, p->chan->exten, 1, p->owner->cid.cid_num)) {
		ast_log(LOG_NOTICE, "No such extension/context %s@%s while calling Local channel\n", p->chan->exten, p->chan->context);
		ao2_unlock(p);
		return -1;
	}

	/* Start switch on sub channel */
	if (!(res = ast_pbx_start(p->chan)))
		ast_set_flag(p, LOCAL_LAUNCHED_PBX);

	ao2_unlock(p);
	return res;
}

/*! \brief Hangup a call through the local proxy channel */
static int local_hangup(struct ast_channel *ast)
{
	struct local_pvt *p = ast->tech_pvt;
	int isoutbound;
	struct ast_frame f = { AST_FRAME_CONTROL, AST_CONTROL_HANGUP, .data.uint32 = ast->hangupcause };
	struct ast_channel *ochan = NULL;

	if (!p)
		return -1;

	/* we MUST give the tech_pvt a ref here since we are unlocking the
	 * channel during deadlock avoidance. */
	ao2_ref(p, 1);

	ao2_lock(p);

	isoutbound = IS_OUTBOUND(ast, p);

	if (p->chan && ast_test_flag(ast, AST_FLAG_ANSWERED_ELSEWHERE)) {
		ast_set_flag(p->chan, AST_FLAG_ANSWERED_ELSEWHERE);
		ast_debug(2, "This local call has the ANSWERED_ELSEWHERE flag set.\n");
	}

	if (isoutbound) {
		const char *status = pbx_builtin_getvar_helper(p->chan, "DIALSTATUS");
		if ((status) && (p->owner)) {
			/* Deadlock avoidance */
			while (p->owner && ast_channel_trylock(p->owner)) {
				ao2_unlock(p);
				if (p->chan) {
					ast_channel_unlock(p->chan);
				}
				sched_yield();
				if (p->chan) {
					ast_channel_lock(p->chan);
				}
				ao2_lock(p);
			}
			if (p->owner) {
				pbx_builtin_setvar_helper(p->owner, "CHANLOCALSTATUS", status);
				ast_channel_unlock(p->owner);
			}
		}
		if (!p->chan) {
			/* chan was == to ast and was !NULL before deadlock avoidance started, if chan
			 * is NULL now, then we should bail because that channel
			 * hungup already. This is possible because we let go of the
			 * lock given to the ast channel passed to this function during
			 * deadlock avoidance. */
			ao2_unlock(p);
			ao2_ref(p, -1);
			return 0;
		}
		p->chan = NULL;
		ast_clear_flag(p, LOCAL_LAUNCHED_PBX);
		ast_module_user_remove(p->u_chan);
	} else {
		ast_module_user_remove(p->u_owner);
		while (p->chan && ast_channel_trylock(p->chan)) {
				ao2_unlock(p);
				if (p->owner) {
					ast_channel_unlock(p->owner);
				}
				sched_yield();
				if (p->owner) {
					ast_channel_lock(p->owner);
				}
				ao2_lock(p);
		}
		if (p->chan) {
			ast_queue_hangup(p->chan);
			ast_channel_unlock(p->chan);
		}

		if (!p->owner) {
			/* owner was == to ast and was !NULL before deadlock avoidance started, if
			 * owner is NULL now, then we should bail because that channel
			 * hungup already. This is possible because we let go of the
			 * lock given to the ast channel passed to this function during
			 * deadlock avoidance. */
			ao2_unlock(p);
			ao2_ref(p, -1);
			return 0;
		}
		p->owner = NULL;
	}

	ast->tech_pvt = NULL;

	if (!p->owner && !p->chan) {
		ao2_unlock(p);

		/* Remove from list */
		ao2_unlink(locals, p);
		ao2_ref(p, -1);
		return 0;
	}
	if (p->chan && !ast_test_flag(p, LOCAL_LAUNCHED_PBX)) {
		/* Need to actually hangup since there is no PBX */
		ochan = p->chan;
	} else {
		local_queue_frame(p, isoutbound, &f, NULL, 1);
	}

	ao2_unlock(p);
	if (ochan) {
		ast_hangup(ochan);
	}

	ao2_ref(p, -1);
	return 0;
}

/*! \brief Create a call structure */
static struct local_pvt *local_alloc(const char *data, int format)
{
	struct local_pvt *tmp = NULL;
	char *c = NULL, *opts = NULL;

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

	/* Initialize private structure information */
	ast_copy_string(tmp->exten, data, sizeof(tmp->exten));

	memcpy(&tmp->jb_conf, &g_jb_conf, sizeof(tmp->jb_conf));

	/* Look for options */
	if ((opts = strchr(tmp->exten, '/'))) {
		*opts++ = '\0';
		if (strchr(opts, 'n'))
			ast_set_flag(tmp, LOCAL_NO_OPTIMIZATION);
		if (strchr(opts, 'j')) {
			if (ast_test_flag(tmp, LOCAL_NO_OPTIMIZATION))
				ast_set_flag(&tmp->jb_conf, AST_JB_ENABLED);
			else {
				ast_log(LOG_ERROR, "You must use the 'n' option for chan_local "
					"to use the 'j' option to enable the jitterbuffer\n");
			}
		}
		if (strchr(opts, 'b')) {
			ast_set_flag(tmp, LOCAL_BRIDGE);
		}
		if (strchr(opts, 'm')) {
			ast_set_flag(tmp, LOCAL_MOH_PASSTHRU);
		}
	}

	/* Look for a context */
	if ((c = strchr(tmp->exten, '@')))
		*c++ = '\0';

	ast_copy_string(tmp->context, c ? c : "default", sizeof(tmp->context));

	tmp->reqformat = format;

#if 0
	/* We can't do this check here, because we don't know the CallerID yet, and
	 * the CallerID could potentially affect what step is actually taken (or
	 * even if that step exists). */
	if (!ast_exists_extension(NULL, tmp->context, tmp->exten, 1, NULL)) {
		ast_log(LOG_NOTICE, "No such extension/context %s@%s creating local channel\n", tmp->exten, tmp->context);
		tmp = local_pvt_destroy(tmp);
	} else {
#endif
		/* Add to list */
		ao2_link(locals, tmp);
#if 0
	}
#endif
	return tmp; /* this is returned with a ref */
}

/*! \brief Start new local channel */
static struct ast_channel *local_new(struct local_pvt *p, int state)
{
	struct ast_channel *tmp = NULL, *tmp2 = NULL;
	int randnum = ast_random() & 0xffff, fmt = 0;
	const char *t;
	int ama;

	/* Allocate two new Asterisk channels */
	/* safe accountcode */
	if (p->owner && p->owner->accountcode)
		t = p->owner->accountcode;
	else
		t = "";

	if (p->owner)
		ama = p->owner->amaflags;
	else
		ama = 0;
	if (!(tmp = ast_channel_alloc(1, state, 0, 0, t, p->exten, p->context, ama, "Local/%s@%s-%04x;1", p->exten, p->context, randnum)) 
			|| !(tmp2 = ast_channel_alloc(1, AST_STATE_RING, 0, 0, t, p->exten, p->context, ama, "Local/%s@%s-%04x;2", p->exten, p->context, randnum))) {
		if (tmp)
			ast_channel_free(tmp);
		if (tmp2)
			ast_channel_free(tmp2);
		ast_log(LOG_WARNING, "Unable to allocate channel structure(s)\n");
		return NULL;
	} 

	tmp2->tech = tmp->tech = &local_tech;

	tmp->nativeformats = p->reqformat;
	tmp2->nativeformats = p->reqformat;

	/* Determine our read/write format and set it on each channel */
	fmt = ast_best_codec(p->reqformat);
	tmp->writeformat = fmt;
	tmp2->writeformat = fmt;
	tmp->rawwriteformat = fmt;
	tmp2->rawwriteformat = fmt;
	tmp->readformat = fmt;
	tmp2->readformat = fmt;
	tmp->rawreadformat = fmt;
	tmp2->rawreadformat = fmt;

	tmp->tech_pvt = p;
	tmp2->tech_pvt = p;

	p->owner = tmp;
	p->chan = tmp2;
	p->u_owner = ast_module_user_add(p->owner);
	p->u_chan = ast_module_user_add(p->chan);

	ast_copy_string(tmp->context, p->context, sizeof(tmp->context));
	ast_copy_string(tmp2->context, p->context, sizeof(tmp2->context));
	ast_copy_string(tmp2->exten, p->exten, sizeof(tmp->exten));
	tmp->priority = 1;
	tmp2->priority = 1;

	ast_jb_configure(tmp, &p->jb_conf);

	return tmp;
}

/*! \brief Part of PBX interface */
static struct ast_channel *local_request(const char *type, int format, void *data, int *cause)
{
	struct local_pvt *p = NULL;
	struct ast_channel *chan = NULL;

	/* Allocate a new private structure and then Asterisk channel */
	if ((p = local_alloc(data, format))) {
		if (!(chan = local_new(p, AST_STATE_DOWN))) {
			ao2_unlink(locals, p);
		}
		ao2_ref(p, -1); /* kill the ref from the alloc */
	}

	return chan;
}

/*! \brief CLI command "local show channels" */
static char *locals_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	struct local_pvt *p = NULL;
	struct ao2_iterator it;

	switch (cmd) {
	case CLI_INIT:
		e->command = "local show channels";
		e->usage =
			"Usage: local show channels\n"
			"       Provides summary information on active local proxy channels.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc != 3)
		return CLI_SHOWUSAGE;

	if (ao2_container_count(locals) == 0) {
		ast_cli(a->fd, "No local channels in use\n");
		return RESULT_SUCCESS;
	}

	it = ao2_iterator_init(locals, 0);
	while ((p = ao2_iterator_next(&it))) {
		ao2_lock(p);
		ast_cli(a->fd, "%s -- %s@%s\n", p->owner ? p->owner->name : "<unowned>", p->exten, p->context);
		ao2_unlock(p);
		ao2_ref(p, -1);
	}
	ao2_iterator_destroy(&it);

	return CLI_SUCCESS;
}

static struct ast_cli_entry cli_local[] = {
	AST_CLI_DEFINE(locals_show, "List status of local channels"),
};

static int locals_cmp_cb(void *obj, void *arg, int flags)
{
	return (obj == arg) ? CMP_MATCH : 0;
}

/*! \brief Load module into PBX, register channel */
static int load_module(void)
{
	if (!(locals = ao2_container_alloc(BUCKET_SIZE, NULL, locals_cmp_cb))) {
		return AST_MODULE_LOAD_FAILURE;
	}

	/* Make sure we can register our channel type */
	if (ast_channel_register(&local_tech)) {
		ast_log(LOG_ERROR, "Unable to register channel class 'Local'\n");
		ao2_ref(locals, -1);
		return AST_MODULE_LOAD_FAILURE;
	}
	ast_cli_register_multiple(cli_local, sizeof(cli_local) / sizeof(struct ast_cli_entry));
	return AST_MODULE_LOAD_SUCCESS;
}

/*! \brief Unload the local proxy channel from Asterisk */
static int unload_module(void)
{
	struct local_pvt *p = NULL;
	struct ao2_iterator it;

	/* First, take us out of the channel loop */
	ast_cli_unregister_multiple(cli_local, sizeof(cli_local) / sizeof(struct ast_cli_entry));
	ast_channel_unregister(&local_tech);

	it = ao2_iterator_init(locals, 0);
	while ((p = ao2_iterator_next(&it))) {
		if (p->owner) {
			ast_softhangup(p->owner, AST_SOFTHANGUP_APPUNLOAD);
		}
		ao2_ref(p, -1);
	}
	ao2_iterator_destroy(&it);
	ao2_ref(locals, -1);
	return 0;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Local Proxy Channel (Note: used internally by other modules)");