Merged revisions 106552 via svnmerge from
[asterisk/asterisk.git] / main / channel.c
1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 1999 - 2006, Digium, Inc.
5  *
6  * Mark Spencer <markster@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 /*! \file
20  *
21  * \brief Channel Management
22  *
23  * \author Mark Spencer <markster@digium.com>
24  */
25
26 #include "asterisk.h"
27
28 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
29
30 #include "asterisk/_private.h"
31
32 #include <sys/time.h>
33 #include <signal.h>
34 #include <math.h>
35
36 #include "asterisk/paths.h"     /* use ast_config_AST_SYSTEM_NAME */
37 #include "asterisk/zapata.h"
38
39 #include "asterisk/pbx.h"
40 #include "asterisk/frame.h"
41 #include "asterisk/sched.h"
42 #include "asterisk/channel.h"
43 #include "asterisk/musiconhold.h"
44 #include "asterisk/say.h"
45 #include "asterisk/file.h"
46 #include "asterisk/cli.h"
47 #include "asterisk/translate.h"
48 #include "asterisk/manager.h"
49 #include "asterisk/chanvars.h"
50 #include "asterisk/linkedlists.h"
51 #include "asterisk/indications.h"
52 #include "asterisk/monitor.h"
53 #include "asterisk/causes.h"
54 #include "asterisk/callerid.h"
55 #include "asterisk/utils.h"
56 #include "asterisk/lock.h"
57 #include "asterisk/app.h"
58 #include "asterisk/transcap.h"
59 #include "asterisk/devicestate.h"
60 #include "asterisk/sha1.h"
61 #include "asterisk/threadstorage.h"
62 #include "asterisk/slinfactory.h"
63 #include "asterisk/audiohook.h"
64
65 #ifdef HAVE_EPOLL
66 #include <sys/epoll.h>
67 #endif
68
69 struct ast_epoll_data {
70         struct ast_channel *chan;
71         int which;
72 };
73
74 /* uncomment if you have problems with 'monitoring' synchronized files */
75 #if 0
76 #define MONITOR_CONSTANT_DELAY
77 #define MONITOR_DELAY   150 * 8         /*!< 150 ms of MONITORING DELAY */
78 #endif
79
80 /*! \brief Prevent new channel allocation if shutting down. */
81 static int shutting_down;
82
83 static int uniqueint;
84
85 unsigned long global_fin, global_fout;
86
87 AST_THREADSTORAGE(state2str_threadbuf);
88 #define STATE2STR_BUFSIZE   32
89
90 /*! Default amount of time to use when emulating a digit as a begin and end 
91  *  100ms */
92 #define AST_DEFAULT_EMULATE_DTMF_DURATION 100
93
94 /*! Minimum allowed digit length - 80ms */
95 #define AST_MIN_DTMF_DURATION 80
96
97 /*! Minimum amount of time between the end of the last digit and the beginning 
98  *  of a new one - 45ms */
99 #define AST_MIN_DTMF_GAP 45
100
101 /*! \brief List of channel drivers */
102 struct chanlist {
103         const struct ast_channel_tech *tech;
104         AST_LIST_ENTRY(chanlist) list;
105 };
106
107 #ifdef CHANNEL_TRACE
108 /*! \brief Structure to hold channel context backtrace data */
109 struct ast_chan_trace_data {
110         int enabled;
111         AST_LIST_HEAD_NOLOCK(, ast_chan_trace) trace;
112 };
113
114 /*! \brief Structure to save contexts where an ast_chan has been into */
115 struct ast_chan_trace {
116         char context[AST_MAX_CONTEXT];
117         char exten[AST_MAX_EXTENSION];
118         int priority;
119         AST_LIST_ENTRY(ast_chan_trace) entry;
120 };
121 #endif
122
123 /*! \brief the list of registered channel types */
124 static AST_LIST_HEAD_NOLOCK_STATIC(backends, chanlist);
125
126 /*! \brief the list of channels we have. Note that the lock for this list is used for
127         both the channels list and the backends list.  */
128 static AST_RWLIST_HEAD_STATIC(channels, ast_channel);
129
130 /*! \brief map AST_CAUSE's to readable string representations 
131  *
132  * \ref causes.h
133 */
134 const struct ast_cause {
135         int cause;
136         const char *name;
137         const char *desc;
138 } causes[] = {
139         { AST_CAUSE_UNALLOCATED, "UNALLOCATED", "Unallocated (unassigned) number" },
140         { AST_CAUSE_NO_ROUTE_TRANSIT_NET, "NO_ROUTE_TRANSIT_NET", "No route to specified transmit network" },
141         { AST_CAUSE_NO_ROUTE_DESTINATION, "NO_ROUTE_DESTINATION", "No route to destination" },
142         { AST_CAUSE_CHANNEL_UNACCEPTABLE, "CHANNEL_UNACCEPTABLE", "Channel unacceptable" },
143         { AST_CAUSE_CALL_AWARDED_DELIVERED, "CALL_AWARDED_DELIVERED", "Call awarded and being delivered in an established channel" },
144         { AST_CAUSE_NORMAL_CLEARING, "NORMAL_CLEARING", "Normal Clearing" },
145         { AST_CAUSE_USER_BUSY, "USER_BUSY", "User busy" },
146         { AST_CAUSE_NO_USER_RESPONSE, "NO_USER_RESPONSE", "No user responding" },
147         { AST_CAUSE_NO_ANSWER, "NO_ANSWER", "User alerting, no answer" },
148         { AST_CAUSE_CALL_REJECTED, "CALL_REJECTED", "Call Rejected" },
149         { AST_CAUSE_NUMBER_CHANGED, "NUMBER_CHANGED", "Number changed" },
150         { AST_CAUSE_DESTINATION_OUT_OF_ORDER, "DESTINATION_OUT_OF_ORDER", "Destination out of order" },
151         { AST_CAUSE_INVALID_NUMBER_FORMAT, "INVALID_NUMBER_FORMAT", "Invalid number format" },
152         { AST_CAUSE_FACILITY_REJECTED, "FACILITY_REJECTED", "Facility rejected" },
153         { AST_CAUSE_RESPONSE_TO_STATUS_ENQUIRY, "RESPONSE_TO_STATUS_ENQUIRY", "Response to STATus ENQuiry" },
154         { AST_CAUSE_NORMAL_UNSPECIFIED, "NORMAL_UNSPECIFIED", "Normal, unspecified" },
155         { AST_CAUSE_NORMAL_CIRCUIT_CONGESTION, "NORMAL_CIRCUIT_CONGESTION", "Circuit/channel congestion" },
156         { AST_CAUSE_NETWORK_OUT_OF_ORDER, "NETWORK_OUT_OF_ORDER", "Network out of order" },
157         { AST_CAUSE_NORMAL_TEMPORARY_FAILURE, "NORMAL_TEMPORARY_FAILURE", "Temporary failure" },
158         { AST_CAUSE_SWITCH_CONGESTION, "SWITCH_CONGESTION", "Switching equipment congestion" },
159         { AST_CAUSE_ACCESS_INFO_DISCARDED, "ACCESS_INFO_DISCARDED", "Access information discarded" },
160         { AST_CAUSE_REQUESTED_CHAN_UNAVAIL, "REQUESTED_CHAN_UNAVAIL", "Requested channel not available" },
161         { AST_CAUSE_PRE_EMPTED, "PRE_EMPTED", "Pre-empted" },
162         { AST_CAUSE_FACILITY_NOT_SUBSCRIBED, "FACILITY_NOT_SUBSCRIBED", "Facility not subscribed" },
163         { AST_CAUSE_OUTGOING_CALL_BARRED, "OUTGOING_CALL_BARRED", "Outgoing call barred" },
164         { AST_CAUSE_INCOMING_CALL_BARRED, "INCOMING_CALL_BARRED", "Incoming call barred" },
165         { AST_CAUSE_BEARERCAPABILITY_NOTAUTH, "BEARERCAPABILITY_NOTAUTH", "Bearer capability not authorized" },
166         { AST_CAUSE_BEARERCAPABILITY_NOTAVAIL, "BEARERCAPABILITY_NOTAVAIL", "Bearer capability not available" },
167         { AST_CAUSE_BEARERCAPABILITY_NOTIMPL, "BEARERCAPABILITY_NOTIMPL", "Bearer capability not implemented" },
168         { AST_CAUSE_CHAN_NOT_IMPLEMENTED, "CHAN_NOT_IMPLEMENTED", "Channel not implemented" },
169         { AST_CAUSE_FACILITY_NOT_IMPLEMENTED, "FACILITY_NOT_IMPLEMENTED", "Facility not implemented" },
170         { AST_CAUSE_INVALID_CALL_REFERENCE, "INVALID_CALL_REFERENCE", "Invalid call reference value" },
171         { AST_CAUSE_INCOMPATIBLE_DESTINATION, "INCOMPATIBLE_DESTINATION", "Incompatible destination" },
172         { AST_CAUSE_INVALID_MSG_UNSPECIFIED, "INVALID_MSG_UNSPECIFIED", "Invalid message unspecified" },
173         { AST_CAUSE_MANDATORY_IE_MISSING, "MANDATORY_IE_MISSING", "Mandatory information element is missing" },
174         { AST_CAUSE_MESSAGE_TYPE_NONEXIST, "MESSAGE_TYPE_NONEXIST", "Message type nonexist." },
175         { AST_CAUSE_WRONG_MESSAGE, "WRONG_MESSAGE", "Wrong message" },
176         { AST_CAUSE_IE_NONEXIST, "IE_NONEXIST", "Info. element nonexist or not implemented" },
177         { AST_CAUSE_INVALID_IE_CONTENTS, "INVALID_IE_CONTENTS", "Invalid information element contents" },
178         { AST_CAUSE_WRONG_CALL_STATE, "WRONG_CALL_STATE", "Message not compatible with call state" },
179         { AST_CAUSE_RECOVERY_ON_TIMER_EXPIRE, "RECOVERY_ON_TIMER_EXPIRE", "Recover on timer expiry" },
180         { AST_CAUSE_MANDATORY_IE_LENGTH_ERROR, "MANDATORY_IE_LENGTH_ERROR", "Mandatory IE length error" },
181         { AST_CAUSE_PROTOCOL_ERROR, "PROTOCOL_ERROR", "Protocol error, unspecified" },
182         { AST_CAUSE_INTERWORKING, "INTERWORKING", "Interworking, unspecified" },
183 };
184
185 struct ast_variable *ast_channeltype_list(void)
186 {
187         struct chanlist *cl;
188         struct ast_variable *var=NULL, *prev = NULL;
189         AST_LIST_TRAVERSE(&backends, cl, list) {
190                 if (prev)  {
191                         if ((prev->next = ast_variable_new(cl->tech->type, cl->tech->description, "")))
192                                 prev = prev->next;
193                 } else {
194                         var = ast_variable_new(cl->tech->type, cl->tech->description, "");
195                         prev = var;
196                 }
197         }
198         return var;
199 }
200
201 /*! \brief Show channel types - CLI command */
202 static char *handle_cli_core_show_channeltypes(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
203 {
204 #define FORMAT  "%-10.10s  %-40.40s %-12.12s %-12.12s %-12.12s\n"
205         struct chanlist *cl;
206         int count_chan = 0;
207
208         switch (cmd) {
209         case CLI_INIT:
210                 e->command = "core show channeltypes";
211                 e->usage =
212                         "Usage: core show channeltypes\n"
213                         "       Lists available channel types registered in your\n"
214                         "       Asterisk server.\n";
215                 return NULL;
216         case CLI_GENERATE:
217                 return NULL;
218         }
219
220         if (a->argc != 3)
221                 return CLI_SHOWUSAGE;
222
223         ast_cli(a->fd, FORMAT, "Type", "Description",       "Devicestate", "Indications", "Transfer");
224         ast_cli(a->fd, FORMAT, "----------", "-----------", "-----------", "-----------", "--------");
225
226         AST_RWLIST_RDLOCK(&channels);
227
228         AST_LIST_TRAVERSE(&backends, cl, list) {
229                 ast_cli(a->fd, FORMAT, cl->tech->type, cl->tech->description,
230                         (cl->tech->devicestate) ? "yes" : "no",
231                         (cl->tech->indicate) ? "yes" : "no",
232                         (cl->tech->transfer) ? "yes" : "no");
233                 count_chan++;
234         }
235
236         AST_RWLIST_UNLOCK(&channels);
237
238         ast_cli(a->fd, "----------\n%d channel drivers registered.\n", count_chan);
239
240         return CLI_SUCCESS;
241
242 #undef FORMAT
243 }
244
245 static char *complete_channeltypes(struct ast_cli_args *a)
246 {
247         struct chanlist *cl;
248         int which = 0;
249         int wordlen;
250         char *ret = NULL;
251
252         if (a->pos != 3)
253                 return NULL;
254
255         wordlen = strlen(a->word);
256
257         AST_LIST_TRAVERSE(&backends, cl, list) {
258                 if (!strncasecmp(a->word, cl->tech->type, wordlen) && ++which > a->n) {
259                         ret = ast_strdup(cl->tech->type);
260                         break;
261                 }
262         }
263         
264         return ret;
265 }
266
267 /*! \brief Show details about a channel driver - CLI command */
268 static char *handle_cli_core_show_channeltype(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
269 {
270         struct chanlist *cl = NULL;
271
272         switch (cmd) {
273         case CLI_INIT:
274                 e->command = "core show channeltype";
275                 e->usage =
276                         "Usage: core show channeltype <name>\n"
277                         "       Show details about the specified channel type, <name>.\n";
278                 return NULL;
279         case CLI_GENERATE:
280                 return complete_channeltypes(a);
281         }
282
283         if (a->argc != 4)
284                 return CLI_SHOWUSAGE;
285         
286         AST_RWLIST_RDLOCK(&channels);
287
288         AST_LIST_TRAVERSE(&backends, cl, list) {
289                 if (!strncasecmp(cl->tech->type, a->argv[3], strlen(cl->tech->type)))
290                         break;
291         }
292
293
294         if (!cl) {
295                 ast_cli(a->fd, "\n%s is not a registered channel driver.\n", a->argv[3]);
296                 AST_RWLIST_UNLOCK(&channels);
297                 return CLI_FAILURE;
298         }
299
300         ast_cli(a->fd,
301                 "-- Info about channel driver: %s --\n"
302                 "  Device State: %s\n"
303                 "    Indication: %s\n"
304                 "     Transfer : %s\n"
305                 "  Capabilities: %d\n"
306                 "   Digit Begin: %s\n"
307                 "     Digit End: %s\n"
308                 "    Send HTML : %s\n"
309                 " Image Support: %s\n"
310                 "  Text Support: %s\n",
311                 cl->tech->type,
312                 (cl->tech->devicestate) ? "yes" : "no",
313                 (cl->tech->indicate) ? "yes" : "no",
314                 (cl->tech->transfer) ? "yes" : "no",
315                 (cl->tech->capabilities) ? cl->tech->capabilities : -1,
316                 (cl->tech->send_digit_begin) ? "yes" : "no",
317                 (cl->tech->send_digit_end) ? "yes" : "no",
318                 (cl->tech->send_html) ? "yes" : "no",
319                 (cl->tech->send_image) ? "yes" : "no",
320                 (cl->tech->send_text) ? "yes" : "no"
321                 
322         );
323
324         AST_RWLIST_UNLOCK(&channels);
325         return CLI_SUCCESS;
326 }
327
328 static struct ast_cli_entry cli_channel[] = {
329         AST_CLI_DEFINE(handle_cli_core_show_channeltypes, "List available channel types"),
330         AST_CLI_DEFINE(handle_cli_core_show_channeltype,  "Give more details on that channel type")
331 };
332
333 #ifdef CHANNEL_TRACE
334 /*! \brief Destructor for the channel trace datastore */
335 static void ast_chan_trace_destroy_cb(void *data)
336 {
337         struct ast_chan_trace *trace;
338         struct ast_chan_trace_data *traced = data;
339         while ((trace = AST_LIST_REMOVE_HEAD(&traced->trace, entry))) {
340                 ast_free(trace);
341         }
342         ast_free(traced);
343 }
344
345 /*! \brief Datastore to put the linked list of ast_chan_trace and trace status */
346 const struct ast_datastore_info ast_chan_trace_datastore_info = {
347         .type = "ChanTrace",
348         .destroy = ast_chan_trace_destroy_cb
349 };
350
351 /*! \brief Put the channel backtrace in a string */
352 int ast_channel_trace_serialize(struct ast_channel *chan, struct ast_str **buf)
353 {
354         int total = 0;
355         struct ast_chan_trace *trace;
356         struct ast_chan_trace_data *traced;
357         struct ast_datastore *store;
358
359         ast_channel_lock(chan);
360         store = ast_channel_datastore_find(chan, &ast_chan_trace_datastore_info, NULL);
361         if (!store) {
362                 ast_channel_unlock(chan);
363                 return total;
364         }
365         traced = store->data;
366         (*buf)->used = 0;
367         (*buf)->str[0] = '\0';
368         AST_LIST_TRAVERSE(&traced->trace, trace, entry) {
369                 if (ast_str_append(buf, 0, "[%d] => %s, %s, %d\n", total, trace->context, trace->exten, trace->priority) < 0) {
370                         ast_log(LOG_ERROR, "Data Buffer Size Exceeded!\n");
371                         total = -1;
372                         break;
373                 }
374                 total++;
375         }
376         ast_channel_unlock(chan);
377         return total;
378 }
379
380 /* !\brief Whether or not context tracing is enabled */
381 int ast_channel_trace_is_enabled(struct ast_channel *chan)
382 {
383         struct ast_datastore *store = ast_channel_datastore_find(chan, &ast_chan_trace_datastore_info, NULL);
384         if (!store)
385                 return 0;
386         return ((struct ast_chan_trace_data *)store->data)->enabled;
387 }
388
389 /*! \brief Update the context backtrace data if tracing is enabled */
390 static int ast_channel_trace_data_update(struct ast_channel *chan, struct ast_chan_trace_data *traced)
391 {
392         struct ast_chan_trace *trace;
393         if (!traced->enabled)
394                 return 0;
395         /* If the last saved context does not match the current one
396            OR we have not saved any context so far, then save the current context */
397         if ((!AST_LIST_EMPTY(&traced->trace) && strcasecmp(AST_LIST_FIRST(&traced->trace)->context, chan->context)) || 
398             (AST_LIST_EMPTY(&traced->trace))) {
399                 /* Just do some debug logging */
400                 if (AST_LIST_EMPTY(&traced->trace))
401                         ast_log(LOG_DEBUG, "Setting initial trace context to %s\n", chan->context);
402                 else
403                         ast_log(LOG_DEBUG, "Changing trace context from %s to %s\n", AST_LIST_FIRST(&traced->trace)->context, chan->context);
404                 /* alloc or bail out */
405                 trace = ast_malloc(sizeof(*trace));
406                 if (!trace) 
407                         return -1;
408                 /* save the current location and store it in the trace list */
409                 ast_copy_string(trace->context, chan->context, sizeof(trace->context));
410                 ast_copy_string(trace->exten, chan->exten, sizeof(trace->exten));
411                 trace->priority = chan->priority;
412                 AST_LIST_INSERT_HEAD(&traced->trace, trace, entry);
413         }
414         return 0;
415 }
416
417 /*! \brief Update the context backtrace if tracing is enabled */
418 int ast_channel_trace_update(struct ast_channel *chan)
419 {
420         struct ast_datastore *store = ast_channel_datastore_find(chan, &ast_chan_trace_datastore_info, NULL);
421         if (!store)
422                 return 0;
423         return ast_channel_trace_data_update(chan, store->data);
424 }
425
426 /*! \brief Enable context tracing in the channel */
427 int ast_channel_trace_enable(struct ast_channel *chan)
428 {
429         struct ast_datastore *store = ast_channel_datastore_find(chan, &ast_chan_trace_datastore_info, NULL);
430         struct ast_chan_trace_data *traced;
431         if (!store) {
432                 store = ast_channel_datastore_alloc(&ast_chan_trace_datastore_info, "ChanTrace");
433                 if (!store) 
434                         return -1;
435                 traced = ast_calloc(1, sizeof(*traced));
436                 if (!traced) {
437                         ast_channel_datastore_free(store);
438                         return -1;
439                 }       
440                 store->data = traced;
441                 AST_LIST_HEAD_INIT_NOLOCK(&traced->trace);
442                 ast_channel_datastore_add(chan, store);
443         }       
444         ((struct ast_chan_trace_data *)store->data)->enabled = 1;
445         ast_channel_trace_data_update(chan, store->data);
446         return 0;
447 }
448
449 /*! \brief Disable context tracing in the channel */
450 int ast_channel_trace_disable(struct ast_channel *chan)
451 {
452         struct ast_datastore *store = ast_channel_datastore_find(chan, &ast_chan_trace_datastore_info, NULL);
453         if (!store)
454                 return 0;
455         ((struct ast_chan_trace_data *)store->data)->enabled = 0;
456         return 0;
457 }
458 #endif /* CHANNEL_TRACE */
459
460 /*! \brief Checks to see if a channel is needing hang up */
461 int ast_check_hangup(struct ast_channel *chan)
462 {
463         if (chan->_softhangup)          /* yes if soft hangup flag set */
464                 return 1;
465         if (!chan->tech_pvt)            /* yes if no technology private data */
466                 return 1;
467         if (!chan->whentohangup)        /* no if no hangup scheduled */
468                 return 0;
469         if (chan->whentohangup > time(NULL))    /* no if hangup time has not come yet. */
470                 return 0;
471         chan->_softhangup |= AST_SOFTHANGUP_TIMEOUT;    /* record event */
472         return 1;
473 }
474
475 static int ast_check_hangup_locked(struct ast_channel *chan)
476 {
477         int res;
478         ast_channel_lock(chan);
479         res = ast_check_hangup(chan);
480         ast_channel_unlock(chan);
481         return res;
482 }
483
484 /*! \brief Initiate system shutdown */
485 void ast_begin_shutdown(int hangup)
486 {
487         struct ast_channel *c;
488         shutting_down = 1;
489         if (hangup) {
490                 AST_RWLIST_RDLOCK(&channels);
491                 AST_RWLIST_TRAVERSE(&channels, c, chan_list)
492                         ast_softhangup(c, AST_SOFTHANGUP_SHUTDOWN);
493                 AST_RWLIST_UNLOCK(&channels);
494         }
495 }
496
497 /*! \brief returns number of active/allocated channels */
498 int ast_active_channels(void)
499 {
500         struct ast_channel *c;
501         int cnt = 0;
502         AST_RWLIST_RDLOCK(&channels);
503         AST_RWLIST_TRAVERSE(&channels, c, chan_list)
504                 cnt++;
505         AST_RWLIST_UNLOCK(&channels);
506         return cnt;
507 }
508
509 /*! \brief Cancel a shutdown in progress */
510 void ast_cancel_shutdown(void)
511 {
512         shutting_down = 0;
513 }
514
515 /*! \brief Returns non-zero if Asterisk is being shut down */
516 int ast_shutting_down(void)
517 {
518         return shutting_down;
519 }
520
521 /*! \brief Set when to hangup channel */
522 void ast_channel_setwhentohangup(struct ast_channel *chan, time_t offset)
523 {
524         chan->whentohangup = offset ? time(NULL) + offset : 0;
525         ast_queue_frame(chan, &ast_null_frame);
526         return;
527 }
528
529 /*! \brief Compare a offset with when to hangup channel */
530 int ast_channel_cmpwhentohangup(struct ast_channel *chan, time_t offset)
531 {
532         time_t whentohangup;
533
534         if (!chan->whentohangup)
535                 return (offset == 0) ? 0 : -1;
536
537         if (!offset) /* XXX why is this special? */
538                 return 1;
539
540         whentohangup = offset + time(NULL);
541
542         if (chan->whentohangup < whentohangup)
543                 return 1;
544         else if (chan->whentohangup == whentohangup)
545                 return 0;
546         else
547                 return -1;
548 }
549
550 /*! \brief Register a new telephony channel in Asterisk */
551 int ast_channel_register(const struct ast_channel_tech *tech)
552 {
553         struct chanlist *chan;
554
555         AST_RWLIST_WRLOCK(&channels);
556
557         AST_LIST_TRAVERSE(&backends, chan, list) {
558                 if (!strcasecmp(tech->type, chan->tech->type)) {
559                         ast_log(LOG_WARNING, "Already have a handler for type '%s'\n", tech->type);
560                         AST_RWLIST_UNLOCK(&channels);
561                         return -1;
562                 }
563         }
564         
565         if (!(chan = ast_calloc(1, sizeof(*chan)))) {
566                 AST_RWLIST_UNLOCK(&channels);
567                 return -1;
568         }
569         chan->tech = tech;
570         AST_LIST_INSERT_HEAD(&backends, chan, list);
571
572         ast_debug(1, "Registered handler for '%s' (%s)\n", chan->tech->type, chan->tech->description);
573
574         ast_verb(2, "Registered channel type '%s' (%s)\n", chan->tech->type, chan->tech->description);
575
576         AST_RWLIST_UNLOCK(&channels);
577         return 0;
578 }
579
580 /*! \brief Unregister channel driver */
581 void ast_channel_unregister(const struct ast_channel_tech *tech)
582 {
583         struct chanlist *chan;
584
585         ast_debug(1, "Unregistering channel type '%s'\n", tech->type);
586
587         AST_RWLIST_WRLOCK(&channels);
588
589         AST_LIST_TRAVERSE_SAFE_BEGIN(&backends, chan, list) {
590                 if (chan->tech == tech) {
591                         AST_LIST_REMOVE_CURRENT(list);
592                         ast_free(chan);
593                         ast_verb(2, "Unregistered channel type '%s'\n", tech->type);
594                         break;  
595                 }
596         }
597         AST_LIST_TRAVERSE_SAFE_END;
598
599         AST_RWLIST_UNLOCK(&channels);
600 }
601
602 /*! \brief Get handle to channel driver based on name */
603 const struct ast_channel_tech *ast_get_channel_tech(const char *name)
604 {
605         struct chanlist *chanls;
606         const struct ast_channel_tech *ret = NULL;
607
608         AST_RWLIST_RDLOCK(&channels);
609
610         AST_LIST_TRAVERSE(&backends, chanls, list) {
611                 if (!strcasecmp(name, chanls->tech->type)) {
612                         ret = chanls->tech;
613                         break;
614                 }
615         }
616
617         AST_RWLIST_UNLOCK(&channels);
618         
619         return ret;
620 }
621
622 /*! \brief Gives the string form of a given hangup cause */
623 const char *ast_cause2str(int cause)
624 {
625         int x;
626
627         for (x = 0; x < ARRAY_LEN(causes); x++) {
628                 if (causes[x].cause == cause)
629                         return causes[x].desc;
630         }
631
632         return "Unknown";
633 }
634
635 /*! \brief Convert a symbolic hangup cause to number */
636 int ast_str2cause(const char *name)
637 {
638         int x;
639
640         for (x = 0; x < ARRAY_LEN(causes); x++)
641                 if (!strncasecmp(causes[x].name, name, strlen(causes[x].name)))
642                         return causes[x].cause;
643
644         return -1;
645 }
646
647 /*! \brief Gives the string form of a given channel state.
648         \note This function is not reentrant.
649  */
650 const char *ast_state2str(enum ast_channel_state state)
651 {
652         char *buf;
653
654         switch (state) {
655         case AST_STATE_DOWN:
656                 return "Down";
657         case AST_STATE_RESERVED:
658                 return "Rsrvd";
659         case AST_STATE_OFFHOOK:
660                 return "OffHook";
661         case AST_STATE_DIALING:
662                 return "Dialing";
663         case AST_STATE_RING:
664                 return "Ring";
665         case AST_STATE_RINGING:
666                 return "Ringing";
667         case AST_STATE_UP:
668                 return "Up";
669         case AST_STATE_BUSY:
670                 return "Busy";
671         case AST_STATE_DIALING_OFFHOOK:
672                 return "Dialing Offhook";
673         case AST_STATE_PRERING:
674                 return "Pre-ring";
675         default:
676                 if (!(buf = ast_threadstorage_get(&state2str_threadbuf, STATE2STR_BUFSIZE)))
677                         return "Unknown";
678                 snprintf(buf, STATE2STR_BUFSIZE, "Unknown (%d)", state);
679                 return buf;
680         }
681 }
682
683 /*! \brief Gives the string form of a given transfer capability */
684 char *ast_transfercapability2str(int transfercapability)
685 {
686         switch (transfercapability) {
687         case AST_TRANS_CAP_SPEECH:
688                 return "SPEECH";
689         case AST_TRANS_CAP_DIGITAL:
690                 return "DIGITAL";
691         case AST_TRANS_CAP_RESTRICTED_DIGITAL:
692                 return "RESTRICTED_DIGITAL";
693         case AST_TRANS_CAP_3_1K_AUDIO:
694                 return "3K1AUDIO";
695         case AST_TRANS_CAP_DIGITAL_W_TONES:
696                 return "DIGITAL_W_TONES";
697         case AST_TRANS_CAP_VIDEO:
698                 return "VIDEO";
699         default:
700                 return "UNKNOWN";
701         }
702 }
703
704 /*! \brief Pick the best audio codec */
705 int ast_best_codec(int fmts)
706 {
707         /* This just our opinion, expressed in code.  We are asked to choose
708            the best codec to use, given no information */
709         int x;
710         static const int prefs[] =
711         {
712                 /*! Okay, ulaw is used by all telephony equipment, so start with it */
713                 AST_FORMAT_ULAW,
714                 /*! Unless of course, you're a silly European, so then prefer ALAW */
715                 AST_FORMAT_ALAW,
716                 /*! G.722 is better then all below, but not as common as the above... so give ulaw and alaw priority */
717                 AST_FORMAT_G722,
718                 /*! Okay, well, signed linear is easy to translate into other stuff */
719                 AST_FORMAT_SLINEAR16,
720                 AST_FORMAT_SLINEAR,
721                 /*! G.726 is standard ADPCM, in RFC3551 packing order */
722                 AST_FORMAT_G726,
723                 /*! G.726 is standard ADPCM, in AAL2 packing order */
724                 AST_FORMAT_G726_AAL2,
725                 /*! ADPCM has great sound quality and is still pretty easy to translate */
726                 AST_FORMAT_ADPCM,
727                 /*! Okay, we're down to vocoders now, so pick GSM because it's small and easier to
728                     translate and sounds pretty good */
729                 AST_FORMAT_GSM,
730                 /*! iLBC is not too bad */
731                 AST_FORMAT_ILBC,
732                 /*! Speex is free, but computationally more expensive than GSM */
733                 AST_FORMAT_SPEEX,
734                 /*! Ick, LPC10 sounds terrible, but at least we have code for it, if you're tacky enough
735                     to use it */
736                 AST_FORMAT_LPC10,
737                 /*! G.729a is faster than 723 and slightly less expensive */
738                 AST_FORMAT_G729A,
739                 /*! Down to G.723.1 which is proprietary but at least designed for voice */
740                 AST_FORMAT_G723_1,
741         };
742
743         /* Strip out video */
744         fmts &= AST_FORMAT_AUDIO_MASK;
745         
746         /* Find the first preferred codec in the format given */
747         for (x = 0; x < (sizeof(prefs) / sizeof(prefs[0]) ); x++) {
748                 if (fmts & prefs[x])
749                         return prefs[x];
750         }
751
752         ast_log(LOG_WARNING, "Don't know any of 0x%x formats\n", fmts);
753
754         return 0;
755 }
756
757 static const struct ast_channel_tech null_tech = {
758         .type = "NULL",
759         .description = "Null channel (should not see this)",
760 };
761
762 /*! \brief Create a new channel structure */
763 struct ast_channel *ast_channel_alloc(int needqueue, int state, const char *cid_num, const char *cid_name, const char *acctcode, const char *exten, const char *context, const int amaflag, const char *name_fmt, ...)
764 {
765         struct ast_channel *tmp;
766         int x;
767         int flags;
768         struct varshead *headp;
769         va_list ap1, ap2;
770
771         /* If shutting down, don't allocate any new channels */
772         if (shutting_down) {
773                 ast_log(LOG_WARNING, "Channel allocation failed: Refusing due to active shutdown\n");
774                 return NULL;
775         }
776
777         if (!(tmp = ast_calloc(1, sizeof(*tmp))))
778                 return NULL;
779
780         if (!(tmp->sched = sched_context_create())) {
781                 ast_log(LOG_WARNING, "Channel allocation failed: Unable to create schedule context\n");
782                 ast_free(tmp);
783                 return NULL;
784         }
785         
786         if ((ast_string_field_init(tmp, 128))) {
787                 sched_context_destroy(tmp->sched);
788                 ast_free(tmp);
789                 return NULL;
790         }
791
792 #ifdef HAVE_EPOLL
793         tmp->epfd = epoll_create(25);
794 #endif
795
796         for (x = 0; x < AST_MAX_FDS; x++) {
797                 tmp->fds[x] = -1;
798 #ifdef HAVE_EPOLL
799                 tmp->epfd_data[x] = NULL;
800 #endif
801         }
802
803 #ifdef HAVE_ZAPTEL
804         tmp->timingfd = open("/dev/zap/timer", O_RDWR);
805         if (tmp->timingfd > -1) {
806                 /* Check if timing interface supports new
807                    ping/pong scheme */
808                 flags = 1;
809                 if (!ioctl(tmp->timingfd, ZT_TIMERPONG, &flags))
810                         needqueue = 0;
811         }
812 #else
813         tmp->timingfd = -1;                                     
814 #endif                                  
815
816         if (needqueue) {
817                 if (pipe(tmp->alertpipe)) {
818                         ast_log(LOG_WARNING, "Channel allocation failed: Can't create alert pipe!\n");
819 #ifdef HAVE_ZAPTEL
820                         if (tmp->timingfd > -1)
821                                 close(tmp->timingfd);
822 #endif
823                         sched_context_destroy(tmp->sched);
824                         ast_string_field_free_memory(tmp);
825                         ast_free(tmp);
826                         return NULL;
827                 } else {
828                         flags = fcntl(tmp->alertpipe[0], F_GETFL);
829                         fcntl(tmp->alertpipe[0], F_SETFL, flags | O_NONBLOCK);
830                         flags = fcntl(tmp->alertpipe[1], F_GETFL);
831                         fcntl(tmp->alertpipe[1], F_SETFL, flags | O_NONBLOCK);
832                 }
833         } else  /* Make sure we've got it done right if they don't */
834                 tmp->alertpipe[0] = tmp->alertpipe[1] = -1;
835
836         /* Always watch the alertpipe */
837         ast_channel_set_fd(tmp, AST_ALERT_FD, tmp->alertpipe[0]);
838         /* And timing pipe */
839         ast_channel_set_fd(tmp, AST_TIMING_FD, tmp->timingfd);
840         ast_string_field_set(tmp, name, "**Unknown**");
841
842         /* Initial state */
843         tmp->_state = state;
844
845         tmp->streamid = -1;
846         
847         tmp->fin = global_fin;
848         tmp->fout = global_fout;
849
850         if (ast_strlen_zero(ast_config_AST_SYSTEM_NAME)) {
851                 ast_string_field_build(tmp, uniqueid, "%li.%d", (long) time(NULL), 
852                                        ast_atomic_fetchadd_int(&uniqueint, 1));
853         } else {
854                 ast_string_field_build(tmp, uniqueid, "%s-%li.%d", ast_config_AST_SYSTEM_NAME, 
855                                        (long) time(NULL), ast_atomic_fetchadd_int(&uniqueint, 1));
856         }
857
858         tmp->cid.cid_name = ast_strdup(cid_name);
859         tmp->cid.cid_num = ast_strdup(cid_num);
860         
861         if (!ast_strlen_zero(name_fmt)) {
862                 /* Almost every channel is calling this function, and setting the name via the ast_string_field_build() call.
863                  * And they all use slightly different formats for their name string.
864                  * This means, to set the name here, we have to accept variable args, and call the string_field_build from here.
865                  * This means, that the stringfields must have a routine that takes the va_lists directly, and 
866                  * uses them to build the string, instead of forming the va_lists internally from the vararg ... list.
867                  * This new function was written so this can be accomplished.
868                  */
869                 va_start(ap1, name_fmt);
870                 va_start(ap2, name_fmt);
871                 ast_string_field_build_va(tmp, name, name_fmt, ap1, ap2);
872                 va_end(ap1);
873                 va_end(ap2);
874         }
875
876         /* Reminder for the future: under what conditions do we NOT want to track cdrs on channels? */
877
878         /* These 4 variables need to be set up for the cdr_init() to work right */
879         if (amaflag)
880                 tmp->amaflags = amaflag;
881         else
882                 tmp->amaflags = ast_default_amaflags;
883         
884         if (!ast_strlen_zero(acctcode))
885                 ast_string_field_set(tmp, accountcode, acctcode);
886         else
887                 ast_string_field_set(tmp, accountcode, ast_default_accountcode);
888                 
889         if (!ast_strlen_zero(context))
890                 ast_copy_string(tmp->context, context, sizeof(tmp->context));
891         else
892                 strcpy(tmp->context, "default");
893
894         if (!ast_strlen_zero(exten))
895                 ast_copy_string(tmp->exten, exten, sizeof(tmp->exten));
896         else
897                 strcpy(tmp->exten, "s");
898
899         tmp->priority = 1;
900                 
901         tmp->cdr = ast_cdr_alloc();
902         ast_cdr_init(tmp->cdr, tmp);
903         ast_cdr_start(tmp->cdr);
904         
905         headp = &tmp->varshead;
906         AST_LIST_HEAD_INIT_NOLOCK(headp);
907         
908         ast_mutex_init(&tmp->lock_dont_use);
909         
910         AST_LIST_HEAD_INIT_NOLOCK(&tmp->datastores);
911         
912         ast_string_field_set(tmp, language, defaultlanguage);
913
914         tmp->tech = &null_tech;
915
916         AST_RWLIST_WRLOCK(&channels);
917         AST_RWLIST_INSERT_HEAD(&channels, tmp, chan_list);
918         AST_RWLIST_UNLOCK(&channels);
919
920         /*\!note
921          * and now, since the channel structure is built, and has its name, let's
922          * call the manager event generator with this Newchannel event. This is the
923          * proper and correct place to make this call, but you sure do have to pass
924          * a lot of data into this func to do it here!
925          */
926         if (!ast_strlen_zero(name_fmt)) {
927                 manager_event(EVENT_FLAG_CALL, "Newchannel",
928                         "Channel: %s\r\n"
929                         "ChannelState: %d\r\n"
930                         "ChannelStateDesc: %s\r\n"
931                         "CallerIDNum: %s\r\n"
932                         "CallerIDName: %s\r\n"
933                         "AccountCode: %s\r\n"
934                         "Uniqueid: %s\r\n",
935                         tmp->name, 
936                         state, 
937                         ast_state2str(state),
938                         S_OR(cid_num, ""),
939                         S_OR(cid_name, ""),
940                         tmp->accountcode,
941                         tmp->uniqueid);
942         }
943
944         return tmp;
945 }
946
947 /*! \brief Queue an outgoing media frame */
948 int ast_queue_frame(struct ast_channel *chan, struct ast_frame *fin)
949 {
950         struct ast_frame *f;
951         struct ast_frame *cur;
952         int blah = 1;
953         int qlen = 0;
954
955         /* Build us a copy and free the original one */
956         if (!(f = ast_frdup(fin))) {
957                 ast_log(LOG_WARNING, "Unable to duplicate frame\n");
958                 return -1;
959         }
960         ast_channel_lock(chan);
961
962         /* See if the last frame on the queue is a hangup, if so don't queue anything */
963         if ((cur = AST_LIST_LAST(&chan->readq)) && (cur->frametype == AST_FRAME_CONTROL) && (cur->subclass == AST_CONTROL_HANGUP)) {
964                 ast_frfree(f);
965                 ast_channel_unlock(chan);
966                 return 0;
967         }
968
969         /* Count how many frames exist on the queue */
970         AST_LIST_TRAVERSE(&chan->readq, cur, frame_list) {
971                 qlen++;
972         }
973
974         /* Allow up to 96 voice frames outstanding, and up to 128 total frames */
975         if (((fin->frametype == AST_FRAME_VOICE) && (qlen > 96)) || (qlen  > 128)) {
976                 if (fin->frametype != AST_FRAME_VOICE) {
977                         ast_log(LOG_WARNING, "Exceptionally long queue length queuing to %s\n", chan->name);
978                         CRASH;
979                 } else {
980                         ast_debug(1, "Dropping voice to exceptionally long queue on %s\n", chan->name);
981                         ast_frfree(f);
982                         ast_channel_unlock(chan);
983                         return 0;
984                 }
985         }
986         AST_LIST_INSERT_TAIL(&chan->readq, f, frame_list);
987         if (chan->alertpipe[1] > -1) {
988                 if (write(chan->alertpipe[1], &blah, sizeof(blah)) != sizeof(blah))
989                         ast_log(LOG_WARNING, "Unable to write to alert pipe on %s, frametype/subclass %d/%d (qlen = %d): %s!\n",
990                                 chan->name, f->frametype, f->subclass, qlen, strerror(errno));
991 #ifdef HAVE_ZAPTEL
992         } else if (chan->timingfd > -1) {
993                 ioctl(chan->timingfd, ZT_TIMERPING, &blah);
994 #endif                          
995         } else if (ast_test_flag(chan, AST_FLAG_BLOCKING)) {
996                 pthread_kill(chan->blocker, SIGURG);
997         }
998         ast_channel_unlock(chan);
999         return 0;
1000 }
1001
1002 /*! \brief Queue a hangup frame for channel */
1003 int ast_queue_hangup(struct ast_channel *chan)
1004 {
1005         struct ast_frame f = { AST_FRAME_CONTROL, AST_CONTROL_HANGUP };
1006         /* Yeah, let's not change a lock-critical value without locking */
1007         if (!ast_channel_trylock(chan)) {
1008                 chan->_softhangup |= AST_SOFTHANGUP_DEV;
1009                 ast_channel_unlock(chan);
1010         }
1011         return ast_queue_frame(chan, &f);
1012 }
1013
1014 /*! \brief Queue a control frame */
1015 int ast_queue_control(struct ast_channel *chan, enum ast_control_frame_type control)
1016 {
1017         struct ast_frame f = { AST_FRAME_CONTROL, };
1018
1019         f.subclass = control;
1020
1021         return ast_queue_frame(chan, &f);
1022 }
1023
1024 /*! \brief Queue a control frame with payload */
1025 int ast_queue_control_data(struct ast_channel *chan, enum ast_control_frame_type control,
1026                            const void *data, size_t datalen)
1027 {
1028         struct ast_frame f = { AST_FRAME_CONTROL, };
1029
1030         f.subclass = control;
1031         f.data = (void *) data;
1032         f.datalen = datalen;
1033
1034         return ast_queue_frame(chan, &f);
1035 }
1036
1037 /*! \brief Set defer DTMF flag on channel */
1038 int ast_channel_defer_dtmf(struct ast_channel *chan)
1039 {
1040         int pre = 0;
1041
1042         if (chan) {
1043                 pre = ast_test_flag(chan, AST_FLAG_DEFER_DTMF);
1044                 ast_set_flag(chan, AST_FLAG_DEFER_DTMF);
1045         }
1046         return pre;
1047 }
1048
1049 /*! \brief Unset defer DTMF flag on channel */
1050 void ast_channel_undefer_dtmf(struct ast_channel *chan)
1051 {
1052         if (chan)
1053                 ast_clear_flag(chan, AST_FLAG_DEFER_DTMF);
1054 }
1055
1056 /*!
1057  * \brief Helper function to find channels.
1058  *
1059  * It supports these modes:
1060  *
1061  * prev != NULL : get channel next in list after prev
1062  * name != NULL : get channel with matching name
1063  * name != NULL && namelen != 0 : get channel whose name starts with prefix
1064  * exten != NULL : get channel whose exten or macroexten matches
1065  * context != NULL && exten != NULL : get channel whose context or macrocontext
1066  *
1067  * It returns with the channel's lock held. If getting the individual lock fails,
1068  * unlock and retry quickly up to 10 times, then give up.
1069  *
1070  * \note XXX Note that this code has cost O(N) because of the need to verify
1071  * that the object is still on the global list.
1072  *
1073  * \note XXX also note that accessing fields (e.g. c->name in ast_log())
1074  * can only be done with the lock held or someone could delete the
1075  * object while we work on it. This causes some ugliness in the code.
1076  * Note that removing the first ast_log() may be harmful, as it would
1077  * shorten the retry period and possibly cause failures.
1078  * We should definitely go for a better scheme that is deadlock-free.
1079  */
1080 static struct ast_channel *channel_find_locked(const struct ast_channel *prev,
1081                                                const char *name, const int namelen,
1082                                                const char *context, const char *exten)
1083 {
1084         const char *msg = prev ? "deadlock" : "initial deadlock";
1085         int retries;
1086         struct ast_channel *c;
1087         const struct ast_channel *_prev = prev;
1088
1089         for (retries = 0; retries < 10; retries++) {
1090                 int done;
1091                 AST_RWLIST_RDLOCK(&channels);
1092                 AST_RWLIST_TRAVERSE(&channels, c, chan_list) {
1093                         prev = _prev;
1094                         if (prev) {     /* look for next item */
1095                                 if (c != prev)  /* not this one */
1096                                         continue;
1097                                 /* found, prepare to return c->next */
1098                                 if ((c = AST_RWLIST_NEXT(c, chan_list)) == NULL) break;
1099                                 /* If prev was the last item on the channel list, then we just
1100                                  * want to return NULL, instead of trying to deref NULL in the
1101                                  * next section.
1102                                  */
1103                                 prev = NULL;
1104                                 /* We want prev to be NULL in case we end up doing more searching through
1105                                  * the channel list to find the channel (ie: name searching). If we didn't
1106                                  * set this to NULL the logic would just blow up
1107                                  * XXX Need a better explanation for this ...
1108                                  */
1109                         }
1110                         if (name) { /* want match by name */
1111                                 if ((!namelen && strcasecmp(c->name, name) && strcmp(c->uniqueid, name)) ||
1112                                     (namelen && strncasecmp(c->name, name, namelen)))
1113                                         continue;       /* name match failed */
1114                         } else if (exten) {
1115                                 if (context && strcasecmp(c->context, context) &&
1116                                     strcasecmp(c->macrocontext, context))
1117                                         continue;       /* context match failed */
1118                                 if (strcasecmp(c->exten, exten) &&
1119                                     strcasecmp(c->macroexten, exten))
1120                                         continue;       /* exten match failed */
1121                         }
1122                         /* if we get here, c points to the desired record */
1123                         break;
1124                 }
1125                 /* exit if chan not found or mutex acquired successfully */
1126                 /* this is slightly unsafe, as we _should_ hold the lock to access c->name */
1127                 done = c == NULL || ast_channel_trylock(c) == 0;
1128                 if (!done) {
1129                         ast_debug(1, "Avoiding %s for channel '%p'\n", msg, c);
1130                         if (retries == 9) {
1131                                 /* We are about to fail due to a deadlock, so report this
1132                                  * while we still have the list lock.
1133                                  */
1134                                 ast_debug(1, "Failure, could not lock '%p' after %d retries!\n", c, retries);
1135                                 /* As we have deadlocked, we will skip this channel and
1136                                  * see if there is another match.
1137                                  * NOTE: No point doing this for a full-name match,
1138                                  * as there can be no more matches.
1139                                  */
1140                                 if (!(name && !namelen)) {
1141                                         prev = c;
1142                                         retries = -1;
1143                                 }
1144                         }
1145                 }
1146                 AST_RWLIST_UNLOCK(&channels);
1147                 if (done)
1148                         return c;
1149                 /* If we reach this point we basically tried to lock a channel and failed. Instead of
1150                  * starting from the beginning of the list we can restore our saved pointer to the previous
1151                  * channel and start from there.
1152                  */
1153                 prev = _prev;
1154                 usleep(1);      /* give other threads a chance before retrying */
1155         }
1156
1157         return NULL;
1158 }
1159
1160 /*! \brief Browse channels in use */
1161 struct ast_channel *ast_channel_walk_locked(const struct ast_channel *prev)
1162 {
1163         return channel_find_locked(prev, NULL, 0, NULL, NULL);
1164 }
1165
1166 /*! \brief Get channel by name and lock it */
1167 struct ast_channel *ast_get_channel_by_name_locked(const char *name)
1168 {
1169         return channel_find_locked(NULL, name, 0, NULL, NULL);
1170 }
1171
1172 /*! \brief Get channel by name prefix and lock it */
1173 struct ast_channel *ast_get_channel_by_name_prefix_locked(const char *name, const int namelen)
1174 {
1175         return channel_find_locked(NULL, name, namelen, NULL, NULL);
1176 }
1177
1178 /*! \brief Get next channel by name prefix and lock it */
1179 struct ast_channel *ast_walk_channel_by_name_prefix_locked(const struct ast_channel *chan, const char *name,
1180                                                            const int namelen)
1181 {
1182         return channel_find_locked(chan, name, namelen, NULL, NULL);
1183 }
1184
1185 /*! \brief Get channel by exten (and optionally context) and lock it */
1186 struct ast_channel *ast_get_channel_by_exten_locked(const char *exten, const char *context)
1187 {
1188         return channel_find_locked(NULL, NULL, 0, context, exten);
1189 }
1190
1191 /*! \brief Get next channel by exten (and optionally context) and lock it */
1192 struct ast_channel *ast_walk_channel_by_exten_locked(const struct ast_channel *chan, const char *exten,
1193                                                      const char *context)
1194 {
1195         return channel_find_locked(chan, NULL, 0, context, exten);
1196 }
1197
1198 /*! \brief Wait, look for hangups and condition arg */
1199 int ast_safe_sleep_conditional(struct ast_channel *chan, int ms, int (*cond)(void*), void *data)
1200 {
1201         struct ast_frame *f;
1202
1203         while (ms > 0) {
1204                 if (cond && ((*cond)(data) == 0))
1205                         return 0;
1206                 ms = ast_waitfor(chan, ms);
1207                 if (ms < 0)
1208                         return -1;
1209                 if (ms > 0) {
1210                         f = ast_read(chan);
1211                         if (!f)
1212                                 return -1;
1213                         ast_frfree(f);
1214                 }
1215         }
1216         return 0;
1217 }
1218
1219 /*! \brief Wait, look for hangups */
1220 int ast_safe_sleep(struct ast_channel *chan, int ms)
1221 {
1222         return ast_safe_sleep_conditional(chan, ms, NULL, NULL);
1223 }
1224
1225 static void free_cid(struct ast_callerid *cid)
1226 {
1227         if (cid->cid_dnid)
1228                 ast_free(cid->cid_dnid);
1229         if (cid->cid_num)
1230                 ast_free(cid->cid_num); 
1231         if (cid->cid_name)
1232                 ast_free(cid->cid_name);        
1233         if (cid->cid_ani)
1234                 ast_free(cid->cid_ani);
1235         if (cid->cid_rdnis)
1236                 ast_free(cid->cid_rdnis);
1237         cid->cid_dnid = cid->cid_num = cid->cid_name = cid->cid_ani = cid->cid_rdnis = NULL;
1238 }
1239
1240 /*! \brief Free a channel structure */
1241 void ast_channel_free(struct ast_channel *chan)
1242 {
1243         int fd;
1244 #ifdef HAVE_EPOLL
1245         int i;
1246 #endif
1247         struct ast_var_t *vardata;
1248         struct ast_frame *f;
1249         struct varshead *headp;
1250         struct ast_datastore *datastore = NULL;
1251         char name[AST_CHANNEL_NAME];
1252         
1253         headp=&chan->varshead;
1254         
1255         AST_RWLIST_WRLOCK(&channels);
1256         if (!AST_RWLIST_REMOVE(&channels, chan, chan_list)) {
1257                 AST_RWLIST_UNLOCK(&channels);
1258                 ast_log(LOG_ERROR, "Unable to find channel in list to free. Assuming it has already been done.\n");
1259         }
1260         /* Lock and unlock the channel just to be sure nobody
1261            has it locked still */
1262         ast_channel_lock(chan);
1263         ast_channel_unlock(chan);
1264         if (chan->tech_pvt) {
1265                 ast_log(LOG_WARNING, "Channel '%s' may not have been hung up properly\n", chan->name);
1266                 ast_free(chan->tech_pvt);
1267         }
1268
1269         if (chan->sched)
1270                 sched_context_destroy(chan->sched);
1271
1272         ast_copy_string(name, chan->name, sizeof(name));
1273
1274         /* Stop monitoring */
1275         if (chan->monitor)
1276                 chan->monitor->stop( chan, 0 );
1277
1278         /* If there is native format music-on-hold state, free it */
1279         if (chan->music_state)
1280                 ast_moh_cleanup(chan);
1281
1282         /* Free translators */
1283         if (chan->readtrans)
1284                 ast_translator_free_path(chan->readtrans);
1285         if (chan->writetrans)
1286                 ast_translator_free_path(chan->writetrans);
1287         if (chan->pbx)
1288                 ast_log(LOG_WARNING, "PBX may not have been terminated properly on '%s'\n", chan->name);
1289         free_cid(&chan->cid);
1290         ast_mutex_destroy(&chan->lock_dont_use);
1291         /* Close pipes if appropriate */
1292         if ((fd = chan->alertpipe[0]) > -1)
1293                 close(fd);
1294         if ((fd = chan->alertpipe[1]) > -1)
1295                 close(fd);
1296         if ((fd = chan->timingfd) > -1)
1297                 close(fd);
1298 #ifdef HAVE_EPOLL
1299         for (i = 0; i < AST_MAX_FDS; i++) {
1300                 if (chan->epfd_data[i])
1301                         free(chan->epfd_data[i]);
1302         }
1303         close(chan->epfd);
1304 #endif
1305         while ((f = AST_LIST_REMOVE_HEAD(&chan->readq, frame_list)))
1306                 ast_frfree(f);
1307         
1308         /* Get rid of each of the data stores on the channel */
1309         while ((datastore = AST_LIST_REMOVE_HEAD(&chan->datastores, entry)))
1310                 /* Free the data store */
1311                 ast_channel_datastore_free(datastore);
1312         AST_LIST_HEAD_INIT_NOLOCK(&chan->datastores);
1313
1314         /* loop over the variables list, freeing all data and deleting list items */
1315         /* no need to lock the list, as the channel is already locked */
1316         
1317         while ((vardata = AST_LIST_REMOVE_HEAD(headp, entries)))
1318                 ast_var_delete(vardata);
1319
1320         ast_app_group_discard(chan);
1321
1322         /* Destroy the jitterbuffer */
1323         ast_jb_destroy(chan);
1324
1325         ast_string_field_free_memory(chan);
1326         ast_free(chan);
1327         AST_RWLIST_UNLOCK(&channels);
1328
1329         ast_device_state_changed_literal(name);
1330 }
1331
1332 struct ast_datastore *ast_channel_datastore_alloc(const struct ast_datastore_info *info, const char *uid)
1333 {
1334         struct ast_datastore *datastore = NULL;
1335
1336         /* Make sure we at least have type so we can identify this */
1337         if (!info) {
1338                 return NULL;
1339         }
1340
1341         /* Allocate memory for datastore and clear it */
1342         datastore = ast_calloc(1, sizeof(*datastore));
1343         if (!datastore) {
1344                 return NULL;
1345         }
1346
1347         datastore->info = info;
1348
1349         datastore->uid = ast_strdup(uid);
1350
1351         return datastore;
1352 }
1353
1354 int ast_channel_datastore_free(struct ast_datastore *datastore)
1355 {
1356         int res = 0;
1357
1358         /* Using the destroy function (if present) destroy the data */
1359         if (datastore->info->destroy != NULL && datastore->data != NULL) {
1360                 datastore->info->destroy(datastore->data);
1361                 datastore->data = NULL;
1362         }
1363
1364         /* Free allocated UID memory */
1365         if (datastore->uid != NULL) {
1366                 ast_free((void *) datastore->uid);
1367                 datastore->uid = NULL;
1368         }
1369
1370         /* Finally free memory used by ourselves */
1371         ast_free(datastore);
1372
1373         return res;
1374 }
1375
1376 int ast_channel_datastore_inherit(struct ast_channel *from, struct ast_channel *to)
1377 {
1378         struct ast_datastore *datastore = NULL, *datastore2;
1379
1380         AST_LIST_TRAVERSE(&from->datastores, datastore, entry) {
1381                 if (datastore->inheritance > 0) {
1382                         datastore2 = ast_channel_datastore_alloc(datastore->info, datastore->uid);
1383                         if (datastore2) {
1384                                 datastore2->data = datastore->info->duplicate(datastore->data);
1385                                 datastore2->inheritance = datastore->inheritance == DATASTORE_INHERIT_FOREVER ? DATASTORE_INHERIT_FOREVER : datastore->inheritance - 1;
1386                                 AST_LIST_INSERT_TAIL(&to->datastores, datastore2, entry);
1387                         }
1388                 }
1389         }
1390         return 0;
1391 }
1392
1393 int ast_channel_datastore_add(struct ast_channel *chan, struct ast_datastore *datastore)
1394 {
1395         int res = 0;
1396
1397         AST_LIST_INSERT_HEAD(&chan->datastores, datastore, entry);
1398
1399         return res;
1400 }
1401
1402 int ast_channel_datastore_remove(struct ast_channel *chan, struct ast_datastore *datastore)
1403 {
1404         return AST_LIST_REMOVE(&chan->datastores, datastore, entry) ? 0 : -1;
1405 }
1406
1407 struct ast_datastore *ast_channel_datastore_find(struct ast_channel *chan, const struct ast_datastore_info *info, const char *uid)
1408 {
1409         struct ast_datastore *datastore = NULL;
1410         
1411         if (info == NULL)
1412                 return NULL;
1413
1414         AST_LIST_TRAVERSE_SAFE_BEGIN(&chan->datastores, datastore, entry) {
1415                 if (datastore->info == info) {
1416                         if (uid != NULL && datastore->uid != NULL) {
1417                                 if (!strcasecmp(uid, datastore->uid)) {
1418                                         /* Matched by type AND uid */
1419                                         break;
1420                                 }
1421                         } else {
1422                                 /* Matched by type at least */
1423                                 break;
1424                         }
1425                 }
1426         }
1427         AST_LIST_TRAVERSE_SAFE_END
1428
1429         return datastore;
1430 }
1431
1432 /*! Set the file descriptor on the channel */
1433 void ast_channel_set_fd(struct ast_channel *chan, int which, int fd)
1434 {
1435 #ifdef HAVE_EPOLL
1436         struct epoll_event ev;
1437         struct ast_epoll_data *aed = NULL;
1438
1439         if (chan->fds[which] > -1) {
1440                 epoll_ctl(chan->epfd, EPOLL_CTL_DEL, chan->fds[which], &ev);
1441                 aed = chan->epfd_data[which];
1442         }
1443
1444         /* If this new fd is valid, add it to the epoll */
1445         if (fd > -1) {
1446                 if (!aed && (!(aed = ast_calloc(1, sizeof(*aed)))))
1447                         return;
1448                 
1449                 chan->epfd_data[which] = aed;
1450                 aed->chan = chan;
1451                 aed->which = which;
1452                 
1453                 ev.events = EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP;
1454                 ev.data.ptr = aed;
1455                 epoll_ctl(chan->epfd, EPOLL_CTL_ADD, fd, &ev);
1456         } else if (aed) {
1457                 /* We don't have to keep around this epoll data structure now */
1458                 free(aed);
1459                 chan->epfd_data[which] = NULL;
1460         }
1461 #endif
1462         chan->fds[which] = fd;
1463         return;
1464 }
1465
1466 /*! Add a channel to an optimized waitfor */
1467 void ast_poll_channel_add(struct ast_channel *chan0, struct ast_channel *chan1)
1468 {
1469 #ifdef HAVE_EPOLL
1470         struct epoll_event ev;
1471         int i = 0;
1472
1473         if (chan0->epfd == -1)
1474                 return;
1475
1476         /* Iterate through the file descriptors on chan1, adding them to chan0 */
1477         for (i = 0; i < AST_MAX_FDS; i++) {
1478                 if (chan1->fds[i] == -1)
1479                         continue;
1480                 ev.events = EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP;
1481                 ev.data.ptr = chan1->epfd_data[i];
1482                 epoll_ctl(chan0->epfd, EPOLL_CTL_ADD, chan1->fds[i], &ev);
1483         }
1484
1485 #endif
1486         return;
1487 }
1488
1489 /*! Delete a channel from an optimized waitfor */
1490 void ast_poll_channel_del(struct ast_channel *chan0, struct ast_channel *chan1)
1491 {
1492 #ifdef HAVE_EPOLL
1493         struct epoll_event ev;
1494         int i = 0;
1495
1496         if (chan0->epfd == -1)
1497                 return;
1498
1499         for (i = 0; i < AST_MAX_FDS; i++) {
1500                 if (chan1->fds[i] == -1)
1501                         continue;
1502                 epoll_ctl(chan0->epfd, EPOLL_CTL_DEL, chan1->fds[i], &ev);
1503         }
1504
1505 #endif
1506         return;
1507 }
1508
1509 /*! \brief Softly hangup a channel, don't lock */
1510 int ast_softhangup_nolock(struct ast_channel *chan, int cause)
1511 {
1512         ast_debug(1, "Soft-Hanging up channel '%s'\n", chan->name);
1513         /* Inform channel driver that we need to be hung up, if it cares */
1514         chan->_softhangup |= cause;
1515         ast_queue_frame(chan, &ast_null_frame);
1516         /* Interrupt any poll call or such */
1517         if (ast_test_flag(chan, AST_FLAG_BLOCKING))
1518                 pthread_kill(chan->blocker, SIGURG);
1519         return 0;
1520 }
1521
1522 /*! \brief Softly hangup a channel, lock */
1523 int ast_softhangup(struct ast_channel *chan, int cause)
1524 {
1525         int res;
1526         ast_channel_lock(chan);
1527         res = ast_softhangup_nolock(chan, cause);
1528         ast_channel_unlock(chan);
1529         return res;
1530 }
1531
1532 static void free_translation(struct ast_channel *clone)
1533 {
1534         if (clone->writetrans)
1535                 ast_translator_free_path(clone->writetrans);
1536         if (clone->readtrans)
1537                 ast_translator_free_path(clone->readtrans);
1538         clone->writetrans = NULL;
1539         clone->readtrans = NULL;
1540         clone->rawwriteformat = clone->nativeformats;
1541         clone->rawreadformat = clone->nativeformats;
1542 }
1543
1544 /*! \brief Hangup a channel */
1545 int ast_hangup(struct ast_channel *chan)
1546 {
1547         int res = 0;
1548         struct ast_cdr *cdr = NULL;
1549
1550         /* Don't actually hang up a channel that will masquerade as someone else, or
1551            if someone is going to masquerade as us */
1552         ast_channel_lock(chan);
1553
1554         if (chan->audiohooks) {
1555                 ast_audiohook_detach_list(chan->audiohooks);
1556                 chan->audiohooks = NULL;
1557         }
1558
1559         ast_autoservice_stop(chan);
1560
1561         if (chan->masq) {
1562                 if (ast_do_masquerade(chan))
1563                         ast_log(LOG_WARNING, "Failed to perform masquerade\n");
1564         }
1565
1566         if (chan->masq) {
1567                 ast_log(LOG_WARNING, "%s getting hung up, but someone is trying to masq into us?!?\n", chan->name);
1568                 ast_channel_unlock(chan);
1569                 return 0;
1570         }
1571         /* If this channel is one which will be masqueraded into something,
1572            mark it as a zombie already, so we know to free it later */
1573         if (chan->masqr) {
1574                 ast_set_flag(chan, AST_FLAG_ZOMBIE);
1575                 ast_channel_unlock(chan);
1576                 return 0;
1577         }
1578         free_translation(chan);
1579         /* Close audio stream */
1580         if (chan->stream) {
1581                 ast_closestream(chan->stream);
1582                 chan->stream = NULL;
1583         }
1584         /* Close video stream */
1585         if (chan->vstream) {
1586                 ast_closestream(chan->vstream);
1587                 chan->vstream = NULL;
1588         }
1589         if (chan->sched) {
1590                 sched_context_destroy(chan->sched);
1591                 chan->sched = NULL;
1592         }
1593         
1594         if (chan->generatordata)        /* Clear any tone stuff remaining */
1595                 if (chan->generator && chan->generator->release)
1596                         chan->generator->release(chan, chan->generatordata);
1597         chan->generatordata = NULL;
1598         chan->generator = NULL;
1599         if (chan->cdr) {                /* End the CDR if it hasn't already */
1600                 ast_cdr_end(chan->cdr);
1601                 cdr = chan->cdr;
1602                 chan->cdr = NULL;
1603         }
1604         if (ast_test_flag(chan, AST_FLAG_BLOCKING)) {
1605                 ast_log(LOG_WARNING, "Hard hangup called by thread %ld on %s, while fd "
1606                                         "is blocked by thread %ld in procedure %s!  Expect a failure\n",
1607                                         (long)pthread_self(), chan->name, (long)chan->blocker, chan->blockproc);
1608                 CRASH;
1609         }
1610         if (!ast_test_flag(chan, AST_FLAG_ZOMBIE)) {
1611                 ast_debug(1, "Hanging up channel '%s'\n", chan->name);
1612                 if (chan->tech->hangup)
1613                         res = chan->tech->hangup(chan);
1614         } else {
1615                 ast_debug(1, "Hanging up zombie '%s'\n", chan->name);
1616         }
1617                         
1618         ast_channel_unlock(chan);
1619         manager_event(EVENT_FLAG_CALL, "Hangup",
1620                         "Channel: %s\r\n"
1621                         "Uniqueid: %s\r\n"
1622                         "CallerIDNum: %s\r\n"
1623                         "CallerIDName: %s\r\n"
1624                         "Cause: %d\r\n"
1625                         "Cause-txt: %s\r\n",
1626                         chan->name,
1627                         chan->uniqueid,
1628                         S_OR(chan->cid.cid_num, "<unknown>"),
1629                         S_OR(chan->cid.cid_name, "<unknown>"),
1630                         chan->hangupcause,
1631                         ast_cause2str(chan->hangupcause)
1632                         );
1633         ast_channel_free(chan);
1634
1635         if (cdr)
1636                 ast_cdr_detach(cdr);
1637
1638         return res;
1639 }
1640
1641 int __ast_answer(struct ast_channel *chan, unsigned int delay)
1642 {
1643         int res = 0;
1644
1645         ast_channel_lock(chan);
1646
1647         /* You can't answer an outbound call */
1648         if (ast_test_flag(chan, AST_FLAG_OUTGOING)) {
1649                 ast_channel_unlock(chan);
1650                 return 0;
1651         }
1652
1653         /* Stop if we're a zombie or need a soft hangup */
1654         if (ast_test_flag(chan, AST_FLAG_ZOMBIE) || ast_check_hangup(chan)) {
1655                 ast_channel_unlock(chan);
1656                 return -1;
1657         }
1658
1659         switch (chan->_state) {
1660         case AST_STATE_RINGING:
1661         case AST_STATE_RING:
1662                 if (chan->tech->answer)
1663                         res = chan->tech->answer(chan);
1664                 ast_setstate(chan, AST_STATE_UP);
1665                 ast_cdr_answer(chan->cdr);
1666                 ast_channel_unlock(chan);
1667                 if (delay)
1668                         ast_safe_sleep(chan, delay);
1669                 return res;
1670                 break;
1671         case AST_STATE_UP:
1672                 ast_cdr_answer(chan->cdr);
1673                 break;
1674         default:
1675                 break;
1676         }
1677         chan->visible_indication = 0;
1678         ast_channel_unlock(chan);
1679
1680         return res;
1681 }
1682
1683 int ast_answer(struct ast_channel *chan)
1684 {
1685         return __ast_answer(chan, 500);
1686 }
1687
1688 void ast_deactivate_generator(struct ast_channel *chan)
1689 {
1690         ast_channel_lock(chan);
1691         if (chan->generatordata) {
1692                 if (chan->generator && chan->generator->release)
1693                         chan->generator->release(chan, chan->generatordata);
1694                 chan->generatordata = NULL;
1695                 chan->generator = NULL;
1696                 ast_channel_set_fd(chan, AST_GENERATOR_FD, -1);
1697                 ast_clear_flag(chan, AST_FLAG_WRITE_INT);
1698                 ast_settimeout(chan, 0, NULL, NULL);
1699         }
1700         ast_channel_unlock(chan);
1701 }
1702
1703 static int generator_force(const void *data)
1704 {
1705         /* Called if generator doesn't have data */
1706         void *tmp;
1707         int res;
1708         int (*generate)(struct ast_channel *chan, void *tmp, int datalen, int samples);
1709         struct ast_channel *chan = (struct ast_channel *)data;
1710
1711         ast_channel_lock(chan);
1712         tmp = chan->generatordata;
1713         chan->generatordata = NULL;
1714         generate = chan->generator->generate;
1715         ast_channel_unlock(chan);
1716
1717         res = generate(chan, tmp, 0, 160);
1718
1719         chan->generatordata = tmp;
1720
1721         if (res) {
1722                 ast_debug(1, "Auto-deactivating generator\n");
1723                 ast_deactivate_generator(chan);
1724         }
1725
1726         return 0;
1727 }
1728
1729 int ast_activate_generator(struct ast_channel *chan, struct ast_generator *gen, void *params)
1730 {
1731         int res = 0;
1732
1733         ast_channel_lock(chan);
1734
1735         if (chan->generatordata) {
1736                 if (chan->generator && chan->generator->release)
1737                         chan->generator->release(chan, chan->generatordata);
1738                 chan->generatordata = NULL;
1739         }
1740
1741         ast_prod(chan);
1742         if (gen->alloc && !(chan->generatordata = gen->alloc(chan, params))) {
1743                 res = -1;
1744         }
1745         
1746         if (!res) {
1747                 ast_settimeout(chan, 160, generator_force, chan);
1748                 chan->generator = gen;
1749         }
1750
1751         ast_channel_unlock(chan);
1752
1753         return res;
1754 }
1755
1756 /*! \brief Wait for x amount of time on a file descriptor to have input.  */
1757 int ast_waitfor_n_fd(int *fds, int n, int *ms, int *exception)
1758 {
1759         int winner = -1;
1760         ast_waitfor_nandfds(NULL, 0, fds, n, exception, &winner, ms);
1761         return winner;
1762 }
1763
1764 /*! \brief Wait for x amount of time on a file descriptor to have input.  */
1765 #ifdef HAVE_EPOLL
1766 static struct ast_channel *ast_waitfor_nandfds_classic(struct ast_channel **c, int n, int *fds, int nfds,
1767                                         int *exception, int *outfd, int *ms)
1768 #else
1769 struct ast_channel *ast_waitfor_nandfds(struct ast_channel **c, int n, int *fds, int nfds,
1770                                         int *exception, int *outfd, int *ms)
1771 #endif
1772 {
1773         struct timeval start = { 0 , 0 };
1774         struct pollfd *pfds = NULL;
1775         int res;
1776         long rms;
1777         int x, y, max;
1778         int sz;
1779         time_t now = 0;
1780         long whentohangup = 0, diff;
1781         struct ast_channel *winner = NULL;
1782         struct fdmap {
1783                 int chan;
1784                 int fdno;
1785         } *fdmap = NULL;
1786
1787         if ((sz = n * AST_MAX_FDS + nfds)) {
1788                 pfds = alloca(sizeof(*pfds) * sz);
1789                 fdmap = alloca(sizeof(*fdmap) * sz);
1790         }
1791
1792         if (outfd)
1793                 *outfd = -99999;
1794         if (exception)
1795                 *exception = 0;
1796         
1797         /* Perform any pending masquerades */
1798         for (x = 0; x < n; x++) {
1799                 ast_channel_lock(c[x]);
1800                 if (c[x]->masq && ast_do_masquerade(c[x])) {
1801                         ast_log(LOG_WARNING, "Masquerade failed\n");
1802                         *ms = -1;
1803                         ast_channel_unlock(c[x]);
1804                         return NULL;
1805                 }
1806                 if (c[x]->whentohangup) {
1807                         if (!whentohangup)
1808                                 time(&now);
1809                         diff = c[x]->whentohangup - now;
1810                         if (diff < 1) {
1811                                 /* Should already be hungup */
1812                                 c[x]->_softhangup |= AST_SOFTHANGUP_TIMEOUT;
1813                                 ast_channel_unlock(c[x]);
1814                                 return c[x];
1815                         }
1816                         if (!whentohangup || (diff < whentohangup))
1817                                 whentohangup = diff;
1818                 }
1819                 ast_channel_unlock(c[x]);
1820         }
1821         /* Wait full interval */
1822         rms = *ms;
1823         if (whentohangup) {
1824                 rms = whentohangup * 1000;              /* timeout in milliseconds */
1825                 if (*ms >= 0 && *ms < rms)              /* original *ms still smaller */
1826                         rms =  *ms;
1827         }
1828         /*
1829          * Build the pollfd array, putting the channels' fds first,
1830          * followed by individual fds. Order is important because
1831          * individual fd's must have priority over channel fds.
1832          */
1833         max = 0;
1834         for (x = 0; x < n; x++) {
1835                 for (y = 0; y < AST_MAX_FDS; y++) {
1836                         fdmap[max].fdno = y;  /* fd y is linked to this pfds */
1837                         fdmap[max].chan = x;  /* channel x is linked to this pfds */
1838                         max += ast_add_fd(&pfds[max], c[x]->fds[y]);
1839                 }
1840                 CHECK_BLOCKING(c[x]);
1841         }
1842         /* Add the individual fds */
1843         for (x = 0; x < nfds; x++) {
1844                 fdmap[max].chan = -1;
1845                 max += ast_add_fd(&pfds[max], fds[x]);
1846         }
1847
1848         if (*ms > 0)
1849                 start = ast_tvnow();
1850         
1851         if (sizeof(int) == 4) { /* XXX fix timeout > 600000 on linux x86-32 */
1852                 do {
1853                         int kbrms = rms;
1854                         if (kbrms > 600000)
1855                                 kbrms = 600000;
1856                         res = poll(pfds, max, kbrms);
1857                         if (!res)
1858                                 rms -= kbrms;
1859                 } while (!res && (rms > 0));
1860         } else {
1861                 res = poll(pfds, max, rms);
1862         }
1863         for (x = 0; x < n; x++)
1864                 ast_clear_flag(c[x], AST_FLAG_BLOCKING);
1865         if (res < 0) { /* Simulate a timeout if we were interrupted */
1866                 if (errno != EINTR)
1867                         *ms = -1;
1868                 return NULL;
1869         }
1870         if (whentohangup) {   /* if we have a timeout, check who expired */
1871                 time(&now);
1872                 for (x = 0; x < n; x++) {
1873                         if (c[x]->whentohangup && now >= c[x]->whentohangup) {
1874                                 c[x]->_softhangup |= AST_SOFTHANGUP_TIMEOUT;
1875                                 if (winner == NULL)
1876                                         winner = c[x];
1877                         }
1878                 }
1879         }
1880         if (res == 0) { /* no fd ready, reset timeout and done */
1881                 *ms = 0;        /* XXX use 0 since we may not have an exact timeout. */
1882                 return winner;
1883         }
1884         /*
1885          * Then check if any channel or fd has a pending event.
1886          * Remember to check channels first and fds last, as they
1887          * must have priority on setting 'winner'
1888          */
1889         for (x = 0; x < max; x++) {
1890                 res = pfds[x].revents;
1891                 if (res == 0)
1892                         continue;
1893                 if (fdmap[x].chan >= 0) {       /* this is a channel */
1894                         winner = c[fdmap[x].chan];      /* override previous winners */
1895                         if (res & POLLPRI)
1896                                 ast_set_flag(winner, AST_FLAG_EXCEPTION);
1897                         else
1898                                 ast_clear_flag(winner, AST_FLAG_EXCEPTION);
1899                         winner->fdno = fdmap[x].fdno;
1900                 } else {                        /* this is an fd */
1901                         if (outfd)
1902                                 *outfd = pfds[x].fd;
1903                         if (exception)
1904                                 *exception = (res & POLLPRI) ? -1 : 0;
1905                         winner = NULL;
1906                 }
1907         }
1908         if (*ms > 0) {
1909                 *ms -= ast_tvdiff_ms(ast_tvnow(), start);
1910                 if (*ms < 0)
1911                         *ms = 0;
1912         }
1913         return winner;
1914 }
1915
1916 #ifdef HAVE_EPOLL
1917 static struct ast_channel *ast_waitfor_nandfds_simple(struct ast_channel *chan, int *ms)
1918 {
1919         struct timeval start = { 0 , 0 };
1920         int res = 0;
1921         struct epoll_event ev[1];
1922         long whentohangup = 0, rms = *ms;
1923         time_t now;
1924         struct ast_channel *winner = NULL;
1925         struct ast_epoll_data *aed = NULL;
1926
1927         ast_channel_lock(chan);
1928
1929         /* See if this channel needs to be masqueraded */
1930         if (chan->masq && ast_do_masquerade(chan)) {
1931                 ast_log(LOG_WARNING, "Failed to perform masquerade on %s\n", chan->name);
1932                 *ms = -1;
1933                 ast_channel_unlock(chan);
1934                 return NULL;
1935         }
1936
1937         /* Figure out their timeout */
1938         if (chan->whentohangup) {
1939                 time(&now);
1940                 if ((whentohangup = chan->whentohangup - now) < 1) {
1941                         /* They should already be hungup! */
1942                         chan->_softhangup |= AST_SOFTHANGUP_TIMEOUT;
1943                         ast_channel_unlock(chan);
1944                         return NULL;
1945                 }
1946                 /* If this value is smaller then the current one... make it priority */
1947                 whentohangup *= 1000;
1948                 if (rms > whentohangup)
1949                         rms = whentohangup;
1950         }
1951
1952         ast_channel_unlock(chan);
1953
1954         /* Time to make this channel block... */
1955         CHECK_BLOCKING(chan);
1956
1957         if (*ms > 0)
1958                 start = ast_tvnow();
1959
1960         /* We don't have to add any file descriptors... they are already added, we just have to wait! */
1961         res = epoll_wait(chan->epfd, ev, 1, rms);
1962
1963         /* Stop blocking */
1964         ast_clear_flag(chan, AST_FLAG_BLOCKING);
1965
1966         /* Simulate a timeout if we were interrupted */
1967         if (res < 0) {
1968                 if (errno != EINTR)
1969                         *ms = -1;
1970                 return NULL;
1971         }
1972
1973         /* If this channel has a timeout see if it expired */
1974         if (chan->whentohangup) {
1975                 time(&now);
1976                 if (now >= chan->whentohangup) {
1977                         chan->_softhangup |= AST_SOFTHANGUP_TIMEOUT;
1978                         winner = chan;
1979                 }
1980         }
1981
1982         /* No fd ready, reset timeout and be done for now */
1983         if (!res) {
1984                 *ms = 0;
1985                 return winner;
1986         }
1987
1988         /* See what events are pending */
1989         aed = ev[0].data.ptr;
1990         chan->fdno = aed->which;
1991         if (ev[0].events & EPOLLPRI)
1992                 ast_set_flag(chan, AST_FLAG_EXCEPTION);
1993         else
1994                 ast_clear_flag(chan, AST_FLAG_EXCEPTION);
1995
1996         if (*ms > 0) {
1997                 *ms -= ast_tvdiff_ms(ast_tvnow(), start);
1998                 if (*ms < 0)
1999                         *ms = 0;
2000         }
2001
2002         return chan;
2003 }
2004
2005 static struct ast_channel *ast_waitfor_nandfds_complex(struct ast_channel **c, int n, int *ms)
2006 {
2007         struct timeval start = { 0 , 0 };
2008         int res = 0, i;
2009         struct epoll_event ev[25] = { { 0, } };
2010         long whentohangup = 0, diff, rms = *ms;
2011         time_t now;
2012         struct ast_channel *winner = NULL;
2013
2014         for (i = 0; i < n; i++) {
2015                 ast_channel_lock(c[i]);
2016                 if (c[i]->masq && ast_do_masquerade(c[i])) {
2017                         ast_log(LOG_WARNING, "Masquerade failed\n");
2018                         *ms = -1;
2019                         ast_channel_unlock(c[i]);
2020                         return NULL;
2021                 }
2022                 if (c[i]->whentohangup) {
2023                         if (!whentohangup)
2024                                 time(&now);
2025                         if ((diff = c[i]->whentohangup - now) < 1) {
2026                                 c[i]->_softhangup |= AST_SOFTHANGUP_TIMEOUT;
2027                                 ast_channel_unlock(c[i]);
2028                                 return c[i];
2029                         }
2030                         if (!whentohangup || (diff < whentohangup))
2031                                 whentohangup = diff;
2032                 }
2033                 ast_channel_unlock(c[i]);
2034                 CHECK_BLOCKING(c[i]);
2035         }
2036
2037         rms = *ms;
2038         if (whentohangup) {
2039                 rms = whentohangup * 1000;
2040                 if (*ms >= 0 && *ms < rms)
2041                         rms = *ms;
2042         }
2043
2044         if (*ms > 0)
2045                 start = ast_tvnow();
2046
2047         res = epoll_wait(c[0]->epfd, ev, 25, rms);
2048
2049         for (i = 0; i < n; i++)
2050                 ast_clear_flag(c[i], AST_FLAG_BLOCKING);
2051
2052         if (res < 0) {
2053                 if (errno != EINTR)
2054                         *ms = -1;
2055                 return NULL;
2056         }
2057
2058         if (whentohangup) {
2059                 time(&now);
2060                 for (i = 0; i < n; i++) {
2061                         if (c[i]->whentohangup && now >= c[i]->whentohangup) {
2062                                 c[i]->_softhangup |= AST_SOFTHANGUP_TIMEOUT;
2063                                 if (!winner)
2064                                         winner = c[i];
2065                         }
2066                 }
2067         }
2068
2069         if (!res) {
2070                 *ms = 0;
2071                 return winner;
2072         }
2073
2074         for (i = 0; i < res; i++) {
2075                 struct ast_epoll_data *aed = ev[i].data.ptr;
2076
2077                 if (!ev[i].events || !aed)
2078                         continue;
2079
2080                 winner = aed->chan;
2081                 if (ev[i].events & EPOLLPRI)
2082                         ast_set_flag(winner, AST_FLAG_EXCEPTION);
2083                 else
2084                         ast_clear_flag(winner, AST_FLAG_EXCEPTION);
2085                 winner->fdno = aed->which;
2086         }
2087
2088         if (*ms > 0) {
2089                 *ms -= ast_tvdiff_ms(ast_tvnow(), start);
2090                 if (*ms < 0)
2091                         *ms = 0;
2092         }
2093
2094         return winner;
2095 }
2096
2097 struct ast_channel *ast_waitfor_nandfds(struct ast_channel **c, int n, int *fds, int nfds,
2098                                         int *exception, int *outfd, int *ms)
2099 {
2100         /* Clear all provided values in one place. */
2101         if (outfd)
2102                 *outfd = -99999;
2103         if (exception)
2104                 *exception = 0;
2105
2106         /* If no epoll file descriptor is available resort to classic nandfds */
2107         if (!n || nfds || c[0]->epfd == -1)
2108                 return ast_waitfor_nandfds_classic(c, n, fds, nfds, exception, outfd, ms);
2109         else if (!nfds && n == 1)
2110                 return ast_waitfor_nandfds_simple(c[0], ms);
2111         else
2112                 return ast_waitfor_nandfds_complex(c, n, ms);
2113 }
2114 #endif
2115
2116 struct ast_channel *ast_waitfor_n(struct ast_channel **c, int n, int *ms)
2117 {
2118         return ast_waitfor_nandfds(c, n, NULL, 0, NULL, NULL, ms);
2119 }
2120
2121 int ast_waitfor(struct ast_channel *c, int ms)
2122 {
2123         int oldms = ms; /* -1 if no timeout */
2124
2125         ast_waitfor_nandfds(&c, 1, NULL, 0, NULL, NULL, &ms);
2126         if ((ms < 0) && (oldms < 0))
2127                 ms = 0;
2128         return ms;
2129 }
2130
2131 /* XXX never to be called with ms = -1 */
2132 int ast_waitfordigit(struct ast_channel *c, int ms)
2133 {
2134         return ast_waitfordigit_full(c, ms, -1, -1);
2135 }
2136
2137 int ast_settimeout(struct ast_channel *c, int samples, int (*func)(const void *data), void *data)
2138 {
2139         int res = -1;
2140 #ifdef HAVE_ZAPTEL
2141         if (c->timingfd > -1) {
2142                 if (!func) {
2143                         samples = 0;
2144                         data = 0;
2145                 }
2146                 ast_debug(1, "Scheduling timer at %d sample intervals\n", samples);
2147                 res = ioctl(c->timingfd, ZT_TIMERCONFIG, &samples);
2148                 c->timingfunc = func;
2149                 c->timingdata = data;
2150         }
2151 #endif  
2152         return res;
2153 }
2154
2155 int ast_waitfordigit_full(struct ast_channel *c, int ms, int audiofd, int cmdfd)
2156 {
2157         /* Stop if we're a zombie or need a soft hangup */
2158         if (ast_test_flag(c, AST_FLAG_ZOMBIE) || ast_check_hangup(c))
2159                 return -1;
2160
2161         /* Only look for the end of DTMF, don't bother with the beginning and don't emulate things */
2162         ast_set_flag(c, AST_FLAG_END_DTMF_ONLY);
2163
2164         /* Wait for a digit, no more than ms milliseconds total. */
2165         
2166         while (ms) {
2167                 struct ast_channel *rchan;
2168                 int outfd=-1;
2169
2170                 errno = 0;
2171                 rchan = ast_waitfor_nandfds(&c, 1, &cmdfd, (cmdfd > -1) ? 1 : 0, NULL, &outfd, &ms);
2172                 
2173                 if (!rchan && outfd < 0 && ms) {
2174                         if (errno == 0 || errno == EINTR)
2175                                 continue;
2176                         ast_log(LOG_WARNING, "Wait failed (%s)\n", strerror(errno));
2177                         ast_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
2178                         return -1;
2179                 } else if (outfd > -1) {
2180                         /* The FD we were watching has something waiting */
2181                         ast_log(LOG_WARNING, "The FD we were waiting for has something waiting. Waitfordigit returning numeric 1\n");
2182                         ast_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
2183                         return 1;
2184                 } else if (rchan) {
2185                         int res;
2186                         struct ast_frame *f = ast_read(c);
2187                         if (!f)
2188                                 return -1;
2189
2190                         switch (f->frametype) {
2191                         case AST_FRAME_DTMF_BEGIN:
2192                                 break;
2193                         case AST_FRAME_DTMF_END:
2194                                 res = f->subclass;
2195                                 ast_frfree(f);
2196                                 ast_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
2197                                 return res;
2198                         case AST_FRAME_CONTROL:
2199                                 switch (f->subclass) {
2200                                 case AST_CONTROL_HANGUP:
2201                                         ast_frfree(f);
2202                                         ast_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
2203                                         return -1;
2204                                 case AST_CONTROL_RINGING:
2205                                 case AST_CONTROL_ANSWER:
2206                                         /* Unimportant */
2207                                         break;
2208                                 default:
2209                                         ast_log(LOG_WARNING, "Unexpected control subclass '%d'\n", f->subclass);
2210                                         break;
2211                                 }
2212                                 break;
2213                         case AST_FRAME_VOICE:
2214                                 /* Write audio if appropriate */
2215                                 if (audiofd > -1)
2216                                         write(audiofd, f->data, f->datalen);
2217                         default:
2218                                 /* Ignore */
2219                                 break;
2220                         }
2221                         ast_frfree(f);
2222                 }
2223         }
2224
2225         ast_clear_flag(c, AST_FLAG_END_DTMF_ONLY);
2226
2227         return 0; /* Time is up */
2228 }
2229
2230 static void send_dtmf_event(const struct ast_channel *chan, const char *direction, const char digit, const char *begin, const char *end)
2231 {
2232         manager_event(EVENT_FLAG_DTMF,
2233                         "DTMF",
2234                         "Channel: %s\r\n"
2235                         "Uniqueid: %s\r\n"
2236                         "Digit: %c\r\n"
2237                         "Direction: %s\r\n"
2238                         "Begin: %s\r\n"
2239                         "End: %s\r\n",
2240                         chan->name, chan->uniqueid, digit, direction, begin, end);
2241 }
2242
2243 static void ast_read_generator_actions(struct ast_channel *chan, struct ast_frame *f)
2244 {
2245         if (chan->generatordata &&  !ast_internal_timing_enabled(chan)) {
2246                 void *tmp = chan->generatordata;
2247                 int res;
2248
2249                 if (chan->timingfunc) {
2250                         if (option_debug > 1)
2251                                 ast_log(LOG_DEBUG, "Generator got voice, switching to phase locked mode\n");
2252                         ast_settimeout(chan, 0, NULL, NULL);
2253                 }
2254
2255                 chan->generatordata = NULL;     /* reset, to let writes go through */
2256                 res = chan->generator->generate(chan, tmp, f->datalen, f->samples);
2257                 chan->generatordata = tmp;
2258                 if (res) {
2259                         if (option_debug > 1)
2260                                 ast_log(LOG_DEBUG, "Auto-deactivating generator\n");
2261                         ast_deactivate_generator(chan);
2262                 }
2263
2264         } else if (f->frametype == AST_FRAME_CNG) {
2265                 if (chan->generator && !chan->timingfunc && (chan->timingfd > -1)) {
2266                         if (option_debug > 1)
2267                                 ast_log(LOG_DEBUG, "Generator got CNG, switching to timed mode\n");
2268                         ast_settimeout(chan, 160, generator_force, chan);
2269                 }
2270         }
2271 }
2272
2273 static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
2274 {
2275         struct ast_frame *f = NULL;     /* the return value */
2276         int blah;
2277         int prestate;
2278         int count = 0;
2279
2280         /* this function is very long so make sure there is only one return
2281          * point at the end (there are only two exceptions to this).
2282          */
2283         while(ast_channel_trylock(chan)) {
2284                 if(count++ > 10) 
2285                         /*cannot goto done since the channel is not locked*/
2286                         return &ast_null_frame;
2287                 usleep(1);
2288         }
2289
2290         if (chan->masq) {
2291                 if (ast_do_masquerade(chan))
2292                         ast_log(LOG_WARNING, "Failed to perform masquerade\n");
2293                 else
2294                         f =  &ast_null_frame;
2295                 goto done;
2296         }
2297
2298         /* Stop if we're a zombie or need a soft hangup */
2299         if (ast_test_flag(chan, AST_FLAG_ZOMBIE) || ast_check_hangup(chan)) {
2300                 if (chan->generator)
2301                         ast_deactivate_generator(chan);
2302                 goto done;
2303         }
2304         prestate = chan->_state;
2305
2306         if (!ast_test_flag(chan, AST_FLAG_DEFER_DTMF | AST_FLAG_EMULATE_DTMF | AST_FLAG_IN_DTMF) && 
2307             !ast_strlen_zero(chan->dtmfq) && 
2308                 (ast_tvzero(chan->dtmf_tv) || ast_tvdiff_ms(ast_tvnow(), chan->dtmf_tv) > AST_MIN_DTMF_GAP) ) {
2309                 /* We have DTMF that has been deferred.  Return it now */
2310                 chan->dtmff.subclass = chan->dtmfq[0];
2311                 /* Drop first digit from the buffer */
2312                 memmove(chan->dtmfq, chan->dtmfq + 1, sizeof(chan->dtmfq) - 1);
2313                 f = &chan->dtmff;
2314                 if (ast_test_flag(chan, AST_FLAG_END_DTMF_ONLY)) {
2315                         ast_log(LOG_DTMF, "DTMF end emulation of '%c' queued on %s\n", f->subclass, chan->name);
2316                         chan->dtmff.frametype = AST_FRAME_DTMF_END;
2317                 } else {
2318                         ast_log(LOG_DTMF, "DTMF begin emulation of '%c' with duration %d queued on %s\n", f->subclass, AST_DEFAULT_EMULATE_DTMF_DURATION, chan->name);
2319                         chan->dtmff.frametype = AST_FRAME_DTMF_BEGIN;
2320                         ast_set_flag(chan, AST_FLAG_EMULATE_DTMF);
2321                         chan->emulate_dtmf_digit = f->subclass;
2322                         chan->emulate_dtmf_duration = AST_DEFAULT_EMULATE_DTMF_DURATION;
2323                 }
2324                 chan->dtmf_tv = ast_tvnow();
2325                 goto done;
2326         }
2327         
2328         /* Read and ignore anything on the alertpipe, but read only
2329            one sizeof(blah) per frame that we send from it */
2330         if (chan->alertpipe[0] > -1)
2331                 read(chan->alertpipe[0], &blah, sizeof(blah));
2332
2333 #ifdef HAVE_ZAPTEL
2334         if (chan->timingfd > -1 && chan->fdno == AST_TIMING_FD && ast_test_flag(chan, AST_FLAG_EXCEPTION)) {
2335                 int res;
2336
2337                 ast_clear_flag(chan, AST_FLAG_EXCEPTION);
2338                 blah = -1;
2339                 /* IF we can't get event, assume it's an expired as-per the old interface */
2340                 res = ioctl(chan->timingfd, ZT_GETEVENT, &blah);
2341                 if (res)
2342                         blah = ZT_EVENT_TIMER_EXPIRED;
2343
2344                 if (blah == ZT_EVENT_TIMER_PING) {
2345                         if (AST_LIST_EMPTY(&chan->readq) || !AST_LIST_NEXT(AST_LIST_FIRST(&chan->readq), frame_list)) {
2346                                 /* Acknowledge PONG unless we need it again */
2347                                 if (ioctl(chan->timingfd, ZT_TIMERPONG, &blah)) {
2348                                         ast_log(LOG_WARNING, "Failed to pong timer on '%s': %s\n", chan->name, strerror(errno));
2349                                 }
2350                         }
2351                 } else if (blah == ZT_EVENT_TIMER_EXPIRED) {
2352                         ioctl(chan->timingfd, ZT_TIMERACK, &blah);
2353                         if (chan->timingfunc) {
2354                                 /* save a copy of func/data before unlocking the channel */
2355                                 int (*func)(const void *) = chan->timingfunc;
2356                                 void *data = chan->timingdata;
2357                                 ast_channel_unlock(chan);
2358                                 func(data);
2359                         } else {
2360                                 blah = 0;
2361                                 ioctl(chan->timingfd, ZT_TIMERCONFIG, &blah);
2362                                 chan->timingdata = NULL;
2363                                 ast_channel_unlock(chan);
2364                         }
2365                         /* cannot 'goto done' because the channel is already unlocked */
2366                         return &ast_null_frame;
2367                 } else
2368                         ast_log(LOG_NOTICE, "No/unknown event '%d' on timer for '%s'?\n", blah, chan->name);
2369         } else
2370 #endif
2371         if (chan->fds[AST_GENERATOR_FD] > -1 && chan->fdno == AST_GENERATOR_FD) {
2372                 /* if the AST_GENERATOR_FD is set, call the generator with args
2373                  * set to -1 so it can do whatever it needs to.
2374                  */
2375                 void *tmp = chan->generatordata;
2376                 chan->generatordata = NULL;     /* reset to let ast_write get through */
2377                 chan->generator->generate(chan, tmp, -1, -1);
2378                 chan->generatordata = tmp;
2379                 f = &ast_null_frame;
2380                 goto done;
2381         }
2382
2383         /* Check for pending read queue */
2384         if (!AST_LIST_EMPTY(&chan->readq)) {
2385                 f = AST_LIST_REMOVE_HEAD(&chan->readq, frame_list);
2386                 /* Interpret hangup and return NULL */
2387                 /* XXX why not the same for frames from the channel ? */
2388                 if (f->frametype == AST_FRAME_CONTROL && f->subclass == AST_CONTROL_HANGUP) {
2389                         ast_frfree(f);
2390                         f = NULL;
2391                 }
2392         } else {
2393                 chan->blocker = pthread_self();
2394                 if (ast_test_flag(chan, AST_FLAG_EXCEPTION)) {
2395                         if (chan->tech->exception)
2396                                 f = chan->tech->exception(chan);
2397                         else {
2398                                 ast_log(LOG_WARNING, "Exception flag set on '%s', but no exception handler\n", chan->name);
2399                                 f = &ast_null_frame;
2400                         }
2401                         /* Clear the exception flag */
2402                         ast_clear_flag(chan, AST_FLAG_EXCEPTION);
2403                 } else if (chan->tech->read)
2404                         f = chan->tech->read(chan);
2405                 else
2406                         ast_log(LOG_WARNING, "No read routine on channel %s\n", chan->name);
2407         }
2408
2409         if (f) {
2410                 /* if the channel driver returned more than one frame, stuff the excess
2411                    into the readq for the next ast_read call (note that we can safely assume
2412                    that the readq is empty, because otherwise we would not have called into
2413                    the channel driver and f would be only a single frame)
2414                 */
2415                 if (AST_LIST_NEXT(f, frame_list)) {
2416                         AST_LIST_HEAD_SET_NOLOCK(&chan->readq, AST_LIST_NEXT(f, frame_list));
2417                         AST_LIST_NEXT(f, frame_list) = NULL;
2418                 }
2419
2420                 switch (f->frametype) {
2421                 case AST_FRAME_CONTROL:
2422                         if (f->subclass == AST_CONTROL_ANSWER) {
2423                                 if (!ast_test_flag(chan, AST_FLAG_OUTGOING)) {
2424                                         ast_debug(1, "Ignoring answer on an inbound call!\n");
2425                                         ast_frfree(f);
2426                                         f = &ast_null_frame;
2427                                 } else if (prestate == AST_STATE_UP) {
2428                                         ast_debug(1, "Dropping duplicate answer!\n");
2429                                         ast_frfree(f);
2430                                         f = &ast_null_frame;
2431                                 } else {
2432                                         /* Answer the CDR */
2433                                         ast_setstate(chan, AST_STATE_UP);
2434                                         if (!chan->cdr) { /* up till now, this insertion hasn't been done. Therefore,
2435                                                                                  to keep from throwing off the basic order of the universe,
2436                                                                                  we will try to keep this cdr from getting posted. */
2437                                                 chan->cdr = ast_cdr_alloc();
2438                                                 ast_cdr_init(chan->cdr, chan);
2439                                                 ast_cdr_start(chan->cdr);
2440                                         }
2441                                         
2442                                         ast_cdr_answer(chan->cdr);
2443                                 }
2444                         }
2445                         break;
2446                 case AST_FRAME_DTMF_END:
2447                         send_dtmf_event(chan, "Received", f->subclass, "No", "Yes");
2448                         ast_log(LOG_DTMF, "DTMF end '%c' received on %s, duration %ld ms\n", f->subclass, chan->name, f->len);
2449                         /* Queue it up if DTMF is deffered, or if DTMF emulation is forced.
2450                          * However, only let emulation be forced if the other end cares about BEGIN frames */
2451                         if ( ast_test_flag(chan, AST_FLAG_DEFER_DTMF) ||
2452                                 (ast_test_flag(chan, AST_FLAG_EMULATE_DTMF) && !ast_test_flag(chan, AST_FLAG_END_DTMF_ONLY)) ) {
2453                                 if (strlen(chan->dtmfq) < sizeof(chan->dtmfq) - 2) {
2454                                         ast_log(LOG_DTMF, "DTMF end '%c' put into dtmf queue on %s\n", f->subclass, chan->name);
2455                                         chan->dtmfq[strlen(chan->dtmfq)] = f->subclass;
2456                                 } else
2457                                         ast_log(LOG_WARNING, "Dropping deferred DTMF digits on %s\n", chan->name);
2458                                 ast_frfree(f);
2459                                 f = &ast_null_frame;
2460                         } else if (!ast_test_flag(chan, AST_FLAG_IN_DTMF | AST_FLAG_END_DTMF_ONLY)) {
2461                                 if (!ast_tvzero(chan->dtmf_tv) && 
2462                                     ast_tvdiff_ms(ast_tvnow(), chan->dtmf_tv) < AST_MIN_DTMF_GAP) {
2463                                         /* If it hasn't been long enough, defer this digit */
2464                                         if (strlen(chan->dtmfq) < sizeof(chan->dtmfq) - 2) {
2465                                                 ast_log(LOG_DTMF, "DTMF end '%c' put into dtmf queue on %s\n", f->subclass, chan->name);
2466                                                 chan->dtmfq[strlen(chan->dtmfq)] = f->subclass;
2467                                         } else
2468                                                 ast_log(LOG_WARNING, "Dropping deferred DTMF digits on %s\n", chan->name);
2469                                         ast_frfree(f);
2470                                         f = &ast_null_frame;
2471                                 } else {
2472                                         /* There was no begin, turn this into a begin and send the end later */
2473                                         f->frametype = AST_FRAME_DTMF_BEGIN;
2474                                         ast_set_flag(chan, AST_FLAG_EMULATE_DTMF);
2475                                         chan->emulate_dtmf_digit = f->subclass;
2476                                         chan->dtmf_tv = ast_tvnow();
2477                                         if (f->len) {
2478                                                 if (f->len > AST_MIN_DTMF_DURATION)
2479                                                         chan->emulate_dtmf_duration = f->len;
2480                                                 else 
2481                                                         chan->emulate_dtmf_duration = AST_MIN_DTMF_DURATION;
2482                                         } else
2483                                                 chan->emulate_dtmf_duration = AST_DEFAULT_EMULATE_DTMF_DURATION;
2484                                         ast_log(LOG_DTMF, "DTMF begin emulation of '%c' with duration %u queued on %s\n", f->subclass, chan->emulate_dtmf_duration, chan->name);
2485                                 }
2486                                 if (chan->audiohooks) {
2487                                         struct ast_frame *old_frame = f;
2488                                         /*!
2489                                          * \todo XXX It is possible to write a digit to the audiohook twice
2490                                          * if the digit was originally read while the channel was in autoservice. */
2491                                         f = ast_audiohook_write_list(chan, chan->audiohooks, AST_AUDIOHOOK_DIRECTION_READ, f);
2492                                         if (old_frame != f)
2493                                                 ast_frfree(old_frame);
2494                                 }
2495                         } else {
2496                                 struct timeval now = ast_tvnow();
2497                                 if (ast_test_flag(chan, AST_FLAG_IN_DTMF)) {
2498                                         ast_log(LOG_DTMF, "DTMF end accepted with begin '%c' on %s\n", f->subclass, chan->name);
2499                                         ast_clear_flag(chan, AST_FLAG_IN_DTMF);
2500                                         if (!f->len)
2501                                                 f->len = ast_tvdiff_ms(now, chan->dtmf_tv);
2502                                 } else if (!f->len) {
2503                                         ast_log(LOG_DTMF, "DTMF end accepted without begin '%c' on %s\n", f->subclass, chan->name);
2504                                         f->len = AST_MIN_DTMF_DURATION;
2505                                 }
2506                                 if (f->len < AST_MIN_DTMF_DURATION) {
2507                                         ast_log(LOG_DTMF, "DTMF end '%c' has duration %ld but want minimum %d, emulating on %s\n", f->subclass, f->len, AST_MIN_DTMF_DURATION, chan->name);
2508                                         ast_set_flag(chan, AST_FLAG_EMULATE_DTMF);
2509                                         chan->emulate_dtmf_digit = f->subclass;
2510                                         chan->emulate_dtmf_duration = AST_MIN_DTMF_DURATION - f->len;
2511                                         ast_frfree(f);
2512                                         f = &ast_null_frame;
2513                                 } else {
2514                                         ast_log(LOG_DTMF, "DTMF end passthrough '%c' on %s\n", f->subclass, chan->name);
2515                                         chan->dtmf_tv = now;
2516                                 }
2517                                 if (chan->audiohooks) {
2518                                         struct ast_frame *old_frame = f;
2519                                         f = ast_audiohook_write_list(chan, chan->audiohooks, AST_AUDIOHOOK_DIRECTION_READ, f);
2520                                         if (old_frame != f)
2521                                                 ast_frfree(old_frame);
2522                                 }
2523                         }
2524                         break;
2525                 case AST_FRAME_DTMF_BEGIN:
2526                         send_dtmf_event(chan, "Received", f->subclass, "Yes", "No");
2527                         ast_log(LOG_DTMF, "DTMF begin '%c' received on %s\n", f->subclass, chan->name);
2528                         if ( ast_test_flag(chan, AST_FLAG_DEFER_DTMF | AST_FLAG_END_DTMF_ONLY | AST_FLAG_EMULATE_DTMF) || 
2529                             (!ast_tvzero(chan->dtmf_tv) && 
2530                               ast_tvdiff_ms(ast_tvnow(), chan->dtmf_tv) < AST_MIN_DTMF_GAP) ) {
2531                                 ast_log(LOG_DTMF, "DTMF begin ignored '%c' on %s\n", f->subclass, chan->name);
2532                                 ast_frfree(f);
2533                                 f = &ast_null_frame;
2534                         } else {
2535                                 ast_set_flag(chan, AST_FLAG_IN_DTMF);
2536                                 chan->dtmf_tv = ast_tvnow();
2537                                 ast_log(LOG_DTMF, "DTMF begin passthrough '%c' on %s\n", f->subclass, chan->name);
2538                         }
2539                         break;
2540                 case AST_FRAME_NULL:
2541                         /* The EMULATE_DTMF flag must be cleared here as opposed to when the duration
2542                          * is reached , because we want to make sure we pass at least one
2543                          * voice frame through before starting the next digit, to ensure a gap
2544                          * between DTMF digits. */
2545                         if (ast_test_flag(chan, AST_FLAG_EMULATE_DTMF)) {
2546                                 struct timeval now = ast_tvnow();
2547                                 if (!chan->emulate_dtmf_duration) {
2548                                         ast_clear_flag(chan, AST_FLAG_EMULATE_DTMF);
2549                                         chan->emulate_dtmf_digit = 0;
2550                                 } else if (ast_tvdiff_ms(now, chan->dtmf_tv) >= chan->emulate_dtmf_duration) {
2551                                         chan->emulate_dtmf_duration = 0;
2552                                         ast_frfree(f);
2553                                         f = &chan->dtmff;
2554                                         f->frametype = AST_FRAME_DTMF_END;
2555                                         f->subclass = chan->emulate_dtmf_digit;
2556                                         f->len = ast_tvdiff_ms(now, chan->dtmf_tv);
2557                                         chan->dtmf_tv = now;
2558                                         ast_clear_flag(chan, AST_FLAG_EMULATE_DTMF);
2559                                         chan->emulate_dtmf_digit = 0;
2560                                         ast_log(LOG_DTMF, "DTMF end emulation of '%c' queued on %s\n", f->subclass, chan->name);
2561                                 }
2562                         }
2563                         break;
2564                 case AST_FRAME_VOICE:
2565                         /* The EMULATE_DTMF flag must be cleared here as opposed to when the duration
2566                          * is reached , because we want to make sure we pass at least one
2567                          * voice frame through before starting the next digit, to ensure a gap
2568                          * between DTMF digits. */
2569                         if (ast_test_flag(chan, AST_FLAG_EMULATE_DTMF) && !chan->emulate_dtmf_duration) {
2570                                 ast_clear_flag(chan, AST_FLAG_EMULATE_DTMF);
2571                                 chan->emulate_dtmf_digit = 0;
2572                         }
2573
2574                         if (dropaudio || ast_test_flag(chan, AST_FLAG_IN_DTMF)) {
2575                                 if (dropaudio)
2576                                         ast_read_generator_actions(chan, f);
2577                                 ast_frfree(f);
2578                                 f = &ast_null_frame;
2579                         }
2580
2581                         if (ast_test_flag(chan, AST_FLAG_EMULATE_DTMF) && !ast_test_flag(chan, AST_FLAG_IN_DTMF)) {
2582                                 struct timeval now = ast_tvnow();
2583                                 if (ast_tvdiff_ms(now, chan->dtmf_tv) >= chan->emulate_dtmf_duration) {
2584                                         chan->emulate_dtmf_duration = 0;
2585                                         ast_frfree(f);
2586                                         f = &chan->dtmff;
2587                                         f->frametype = AST_FRAME_DTMF_END;
2588                                         f->subclass = chan->emulate_dtmf_digit;
2589                                         f->len = ast_tvdiff_ms(now, chan->dtmf_tv);
2590                                         chan->dtmf_tv = now;
2591                                         if (chan->audiohooks) {
2592                                                 struct ast_frame *old_frame = f;
2593                                                 f = ast_audiohook_write_list(chan, chan->audiohooks, AST_AUDIOHOOK_DIRECTION_READ, f);
2594                                                 if (old_frame != f)
2595                                                         ast_frfree(old_frame);
2596                                         }
2597                                         ast_log(LOG_DTMF, "DTMF end emulation of '%c' queued on %s\n", f->subclass, chan->name);
2598                                 } else {
2599                                         /* Drop voice frames while we're still in the middle of the digit */
2600                                         ast_frfree(f);
2601                                         f = &ast_null_frame;
2602                                 }
2603                         } else if ((f->frametype == AST_FRAME_VOICE) && !(f->subclass & chan->nativeformats)) {
2604                                 /* This frame can't be from the current native formats -- drop it on the
2605                                    floor */
2606                                 ast_log(LOG_NOTICE, "Dropping incompatible voice frame on %s of format %s since our native format has changed to %s\n",
2607                                         chan->name, ast_getformatname(f->subclass), ast_getformatname(chan->nativeformats));
2608                                 ast_frfree(f);
2609                                 f = &ast_null_frame;
2610                         } else if ((f->frametype == AST_FRAME_VOICE)) {
2611                                 /* Send frame to audiohooks if present */
2612                                 if (chan->audiohooks) {
2613                                         struct ast_frame *old_frame = f;
2614                                         f = ast_audiohook_write_list(chan, chan->audiohooks, AST_AUDIOHOOK_DIRECTION_READ, f);
2615                                         if (old_frame != f)
2616                                                 ast_frfree(old_frame);
2617                                 }
2618                                 if (chan->monitor && chan->monitor->read_stream ) {
2619                                         /* XXX what does this do ? */
2620 #ifndef MONITOR_CONSTANT_DELAY
2621                                         int jump = chan->outsmpl - chan->insmpl - 4 * f->samples;
2622                                         if (jump >= 0) {
2623                                                 jump = chan->outsmpl - chan->insmpl;
2624                                                 if (ast_seekstream(chan->monitor->read_stream, jump, SEEK_FORCECUR) == -1)
2625                                                         ast_log(LOG_WARNING, "Failed to perform seek in monitoring read stream, synchronization between the files may be broken\n");
2626                                                 chan->insmpl += jump + f->samples;
2627                                         } else
2628                                                 chan->insmpl+= f->samples;
2629 #else
2630                                         int jump = chan->outsmpl - chan->insmpl;
2631                                         if (jump - MONITOR_DELAY >= 0) {
2632                                                 if (ast_seekstream(chan->monitor->read_stream, jump - f->samples, SEEK_FORCECUR) == -1)
2633                                                         ast_log(LOG_WARNING, "Failed to perform seek in monitoring read stream, synchronization between the files may be broken\n");
2634                                                 chan->insmpl += jump;
2635                                         } else
2636                                                 chan->insmpl += f->samples;
2637 #endif
2638                                         if (chan->monitor->state == AST_MONITOR_RUNNING) {
2639                                                 if (ast_writestream(chan->monitor->read_stream, f) < 0)
2640                                                         ast_log(LOG_WARNING, "Failed to write data to channel monitor read stream\n");
2641                                         }
2642                                 }
2643
2644                                 if (chan->readtrans && (f = ast_translate(chan->readtrans, f, 1)) == NULL)
2645                                         f = &ast_null_frame;
2646                                 else
2647                                         /* Run generator sitting on the line if timing device not available
2648                                          * and synchronous generation of outgoing frames is necessary       */
2649                                         ast_read_generator_actions(chan, f);
2650                         }
2651                 default:
2652                         /* Just pass it on! */
2653                         break;
2654                 }
2655         } else {
2656                 /* Make sure we always return NULL in the future */
2657                 chan->_softhangup |= AST_SOFTHANGUP_DEV;
2658                 if (chan->generator)
2659                         ast_deactivate_generator(chan);
2660                 /* End the CDR if appropriate */
2661                 if (chan->cdr)
2662                         ast_cdr_end(chan->cdr);
2663         }
2664
2665         /* High bit prints debugging */
2666         if (chan->fin & DEBUGCHAN_FLAG)
2667                 ast_frame_dump(chan->name, f, "<<");
2668         chan->fin = FRAMECOUNT_INC(chan->fin);
2669
2670 done:
2671         if (chan->music_state && chan->generator && chan->generator->digit && f && f->frametype == AST_FRAME_DTMF_END)
2672                 chan->generator->digit(chan, f->subclass);
2673
2674         ast_channel_unlock(chan);
2675         return f;
2676 }
2677
2678 int ast_internal_timing_enabled(struct ast_channel *chan)
2679 {
2680         int ret = ast_opt_internal_timing && chan->timingfd > -1;
2681         ast_debug(5, "Internal timing is %s (option_internal_timing=%d chan->timingfd=%d)\n", ret? "enabled": "disabled", ast_opt_internal_timing, chan->timingfd);
2682         return ret;
2683 }
2684
2685 struct ast_frame *ast_read(struct ast_channel *chan)
2686 {
2687         return __ast_read(chan, 0);
2688 }
2689
2690 struct ast_frame *ast_read_noaudio(struct ast_channel *chan)
2691 {
2692         return __ast_read(chan, 1);
2693 }
2694
2695 int ast_indicate(struct ast_channel *chan, int condition)
2696 {
2697         return ast_indicate_data(chan, condition, NULL, 0);
2698 }
2699
2700 int ast_indicate_data(struct ast_channel *chan, int condition, const void *data, size_t datalen)
2701 {
2702         int res = -1;
2703
2704         ast_channel_lock(chan);
2705         /* Stop if we're a zombie or need a soft hangup */
2706         if (ast_test_flag(chan, AST_FLAG_ZOMBIE) || ast_check_hangup(chan)) {
2707                 ast_channel_unlock(chan);
2708                 return -1;
2709         }
2710         if (chan->tech->indicate)
2711                 res = chan->tech->indicate(chan, condition, data, datalen);
2712         ast_channel_unlock(chan);
2713         if (!chan->tech->indicate || res) {
2714                 /*
2715                  * Device does not support (that) indication, lets fake
2716                  * it by doing our own tone generation. (PM2002)
2717                  */
2718                 if (condition < 0)
2719                         ast_playtones_stop(chan);
2720                 else {
2721                         const struct ind_tone_zone_sound *ts = NULL;
2722                         switch (condition) {
2723                         case AST_CONTROL_RINGING:
2724                                 ts = ast_get_indication_tone(chan->zone, "ring");
2725                                 break;
2726                         case AST_CONTROL_BUSY:
2727                                 ts = ast_get_indication_tone(chan->zone, "busy");
2728                                 break;
2729                         case AST_CONTROL_CONGESTION:
2730                                 ts = ast_get_indication_tone(chan->zone, "congestion");
2731                                 break;
2732                         }
2733                         if (ts && ts->data[0]) {
2734                                 ast_debug(1, "Driver for channel '%s' does not support indication %d, emulating it\n", chan->name, condition);
2735                                 ast_playtones_start(chan,0,ts->data, 1);
2736                                 res = 0;
2737                                 chan->visible_indication = condition;
2738                         } else if (condition == AST_CONTROL_PROGRESS) {
2739                                 /* ast_playtones_stop(chan); */
2740                         } else if (condition == AST_CONTROL_PROCEEDING) {
2741                                 /* Do nothing, really */
2742                         } else if (condition == AST_CONTROL_HOLD) {
2743                                 /* Do nothing.... */
2744                         } else if (condition == AST_CONTROL_UNHOLD) {
2745                                 /* Do nothing.... */
2746                         } else if (condition == AST_CONTROL_VIDUPDATE) {
2747                                 /* Do nothing.... */
2748                         } else if (condition == AST_CONTROL_SRCUPDATE) {
2749                                 /* Do nothing... */
2750                         } else {
2751                                 /* not handled */
2752                                 ast_log(LOG_WARNING, "Unable to handle indication %d for '%s'\n", condition, chan->name);
2753                                 res = -1;
2754                         }
2755                 }
2756         } else
2757                 chan->visible_indication = condition;
2758
2759         return res;
2760 }
2761
2762 int ast_recvchar(struct ast_channel *chan, int timeout)
2763 {
2764         int c;
2765         char *buf = ast_recvtext(chan, timeout);
2766         if (buf == NULL)
2767                 return -1;      /* error or timeout */
2768         c = *(unsigned char *)buf;
2769         ast_free(buf);
2770         return c;
2771 }
2772
2773 char *ast_recvtext(struct ast_channel *chan, int timeout)
2774 {
2775         int res, done = 0;
2776         char *buf = NULL;
2777         
2778         while (!done) {
2779                 struct ast_frame *f;
2780                 if (ast_check_hangup(chan))
2781                         break;
2782                 res = ast_waitfor(chan, timeout);
2783                 if (res <= 0) /* timeout or error */
2784                         break;
2785                 timeout = res;  /* update timeout */
2786                 f = ast_read(chan);
2787                 if (f == NULL)
2788                         break; /* no frame */
2789                 if (f->frametype == AST_FRAME_CONTROL && f->subclass == AST_CONTROL_HANGUP)
2790                         done = 1;       /* force a break */
2791                 else if (f->frametype == AST_FRAME_TEXT) {              /* what we want */
2792                         buf = ast_strndup((char *) f->data, f->datalen);        /* dup and break */
2793                         done = 1;
2794                 }
2795                 ast_frfree(f);
2796         }
2797         return buf;
2798 }
2799
2800 int ast_sendtext(struct ast_channel *chan, const char *text)
2801 {
2802         int res = 0;
2803         /* Stop if we're a zombie or need a soft hangup */
2804         if (ast_test_flag(chan, AST_FLAG_ZOMBIE) || ast_check_hangup(chan))
2805                 return -1;
2806         CHECK_BLOCKING(chan);
2807         if (chan->tech->send_text)
2808                 res = chan->tech->send_text(chan, text);
2809         ast_clear_flag(chan, AST_FLAG_BLOCKING);
2810         return res;
2811 }
2812
2813 int ast_senddigit_begin(struct ast_channel *chan, char digit)
2814 {
2815         /* Device does not support DTMF tones, lets fake
2816          * it by doing our own generation. */
2817         static const char* dtmf_tones[] = {
2818                 "941+1336", /* 0 */
2819                 "697+1209", /* 1 */
2820                 "697+1336", /* 2 */
2821                 "697+1477", /* 3 */
2822                 "770+1209", /* 4 */
2823                 "770+1336", /* 5 */
2824                 "770+1477", /* 6 */
2825                 "852+1209", /* 7 */
2826                 "852+1336", /* 8 */
2827                 "852+1477", /* 9 */
2828                 "697+1633", /* A */
2829                 "770+1633", /* B */
2830                 "852+1633", /* C */
2831                 "941+1633", /* D */
2832                 "941+1209", /* * */
2833                 "941+1477"  /* # */
2834         };
2835
2836         if (!chan->tech->send_digit_begin)
2837                 return 0;
2838
2839         if (!chan->tech->send_digit_begin(chan, digit))
2840                 return 0;
2841
2842         if (digit >= '0' && digit <='9')
2843                 ast_playtones_start(chan, 0, dtmf_tones[digit-'0'], 0);
2844         else if (digit >= 'A' && digit <= 'D')
2845                 ast_playtones_start(chan, 0, dtmf_tones[digit-'A'+10], 0);
2846         else if (digit == '*')
2847                 ast_playtones_start(chan, 0, dtmf_tones[14], 0);
2848         else if (digit == '#')
2849                 ast_playtones_start(chan, 0, dtmf_tones[15], 0);
2850         else {
2851                 /* not handled */
2852                 ast_debug(1, "Unable to generate DTMF tone '%c' for '%s'\n", digit, chan->name);
2853         }
2854
2855         return 0;
2856 }
2857
2858 int ast_senddigit_end(struct ast_channel *chan, char digit, unsigned int duration)
2859 {
2860         int res = -1;
2861
2862         if (chan->tech->send_digit_end)
2863                 res = chan->tech->send_digit_end(chan, digit, duration);
2864
2865         if (res && chan->generator)
2866                 ast_playtones_stop(chan);
2867         
2868         return 0;
2869 }
2870
2871 int ast_senddigit(struct ast_channel *chan, char digit, unsigned int duration)
2872 {
2873         if (chan->tech->send_digit_begin) {
2874                 ast_senddigit_begin(chan, digit);
2875                 ast_safe_sleep(chan, (duration >= AST_DEFAULT_EMULATE_DTMF_DURATION ? duration : AST_DEFAULT_EMULATE_DTMF_DURATION));
2876         }
2877         
2878         return ast_senddigit_end(chan, digit, (duration >= AST_DEFAULT_EMULATE_DTMF_DURATION ? duration : AST_DEFAULT_EMULATE_DTMF_DURATION));
2879 }
2880
2881 int ast_prod(struct ast_channel *chan)
2882 {
2883         struct ast_frame a = { AST_FRAME_VOICE };
2884         char nothing[128];
2885
2886         /* Send an empty audio frame to get things moving */
2887         if (chan->_state != AST_STATE_UP) {
2888                 ast_debug(1, "Prodding channel '%s'\n", chan->name);
2889                 a.subclass = chan->rawwriteformat;
2890                 a.data = nothing + AST_FRIENDLY_OFFSET;
2891                 a.src = "ast_prod";
2892                 if (ast_write(chan, &a))
2893                         ast_log(LOG_WARNING, "Prodding channel '%s' failed\n", chan->name);
2894         }
2895         return 0;
2896 }
2897
2898 int ast_write_video(struct ast_channel *chan, struct ast_frame *fr)
2899 {
2900         int res;
2901         if (!chan->tech->write_video)
2902                 return 0;
2903         res = ast_write(chan, fr);
2904         if (!res)
2905                 res = 1;
2906         return res;
2907 }
2908
2909 int ast_write(struct ast_channel *chan, struct ast_frame *fr)
2910 {
2911         int res = -1;
2912         struct ast_frame *f = NULL, *f2 = NULL;
2913         int count = 0;
2914
2915         /*Deadlock avoidance*/
2916         while(ast_channel_trylock(chan)) {
2917                 /*cannot goto done since the channel is not locked*/
2918                 if(count++ > 10) {
2919                         ast_debug(1, "Deadlock avoided for write to channel '%s'\n", chan->name);
2920                         return 0;
2921                 }
2922                 usleep(1);
2923         }
2924         /* Stop if we're a zombie or need a soft hangup */
2925         if (ast_test_flag(chan, AST_FLAG_ZOMBIE) || ast_check_hangup(chan))
2926                 goto done;
2927
2928         /* Handle any pending masquerades */
2929         if (chan->masq && ast_do_masquerade(chan)) {
2930                 ast_log(LOG_WARNING, "Failed to perform masquerade\n");
2931                 goto done;
2932         }
2933         if (chan->masqr) {
2934                 res = 0;        /* XXX explain, why 0 ? */
2935                 goto done;
2936         }
2937         if (chan->generatordata) {
2938                 if (ast_test_flag(chan, AST_FLAG_WRITE_INT))
2939                         ast_deactivate_generator(chan);
2940                 else {
2941                         if (fr->frametype == AST_FRAME_DTMF_END) {
2942                                 /* There is a generator running while we're in the middle of a digit.
2943                                  * It's probably inband DTMF, so go ahead and pass it so it can
2944                                  * stop the generator */
2945                                 ast_clear_flag(chan, AST_FLAG_BLOCKING);
2946                                 ast_channel_unlock(chan);
2947                                 res = ast_senddigit_end(chan, fr->subclass, fr->len);
2948                                 ast_channel_lock(chan);
2949                                 CHECK_BLOCKING(chan);
2950                         } else if (fr->frametype == AST_FRAME_CONTROL && fr->subclass == AST_CONTROL_UNHOLD) {
2951                                 /* This is a side case where Echo is basically being called and the person put themselves on hold and took themselves off hold */
2952                                 res = (chan->tech->indicate == NULL) ? 0 :
2953                                         chan->tech->indicate(chan, fr->subclass, fr->data, fr->datalen);
2954                         }
2955                         res = 0;        /* XXX explain, why 0 ? */
2956                         goto done;
2957                 }
2958         }
2959         /* High bit prints debugging */
2960         if (chan->fout & DEBUGCHAN_FLAG)
2961                 ast_frame_dump(chan->name, fr, ">>");
2962         CHECK_BLOCKING(chan);
2963         switch (fr->frametype) {
2964         case AST_FRAME_CONTROL:
2965                 res = (chan->tech->indicate == NULL) ? 0 :
2966                         chan->tech->indicate(chan, fr->subclass, fr->data, fr->datalen);
2967                 break;
2968         case AST_FRAME_DTMF_BEGIN:
2969                 if (chan->audiohooks) {
2970                         struct ast_frame *old_frame = fr;
2971                         fr = ast_audiohook_write_list(chan, chan->audiohooks, AST_AUDIOHOOK_DIRECTION_WRITE, fr);
2972                         if (old_frame != fr)
2973                                 f = fr;
2974                 }
2975                 send_dtmf_event(chan, "Sent", fr->subclass, "Yes", "No");
2976                 ast_clear_flag(chan, AST_FLAG_BLOCKING);
2977                 ast_channel_unlock(chan);
2978                 res = ast_senddigit_begin(chan, fr->subclass);
2979                 ast_channel_lock(chan);
2980                 CHECK_BLOCKING(chan);
2981                 break;
2982         case AST_FRAME_DTMF_END:
2983                 if (chan->audiohooks) {
2984                         struct ast_frame *old_frame = fr;
2985                         fr = ast_audiohook_write_list(chan, chan->audiohooks, AST_AUDIOHOOK_DIRECTION_WRITE, fr);
2986                         if (old_frame != fr)
2987                                 f = fr;
2988                 }
2989                 send_dtmf_event(chan, "Sent", fr->subclass, "No", "Yes");
2990                 ast_clear_flag(chan, AST_FLAG_BLOCKING);
2991                 ast_channel_unlock(chan);
2992                 res = ast_senddigit_end(chan, fr->subclass, fr->len);
2993                 ast_channel_lock(chan);
2994                 CHECK_BLOCKING(chan);
2995                 break;
2996         case AST_FRAME_TEXT:
2997                 if (fr->subclass == AST_FORMAT_T140) {
2998                         res = (chan->tech->write_text == NULL) ? 0 :
2999                                 chan->tech->write_text(chan, fr);
3000                 } else {
3001                         res = (chan->tech->send_text == NULL) ? 0 :
3002                                 chan->tech->send_text(chan, (char *) fr->data);
3003                 }
3004                 break;
3005         case AST_FRAME_HTML:
3006                 res = (chan->tech->send_html == NULL) ? 0 :
3007                         chan->tech->send_html(chan, fr->subclass, (char *) fr->data, fr->datalen);
3008                 break;
3009         case AST_FRAME_VIDEO:
3010                 /* XXX Handle translation of video codecs one day XXX */
3011                 res = (chan->tech->write_video == NULL) ? 0 :
3012                         chan->tech->write_video(chan, fr);
3013                 break;
3014         case AST_FRAME_MODEM:
3015                 res = (chan->tech->write == NULL) ? 0 :
3016                         chan->tech->write(chan, fr);
3017                 break;
3018         case AST_FRAME_VOICE:
3019                 if (chan->tech->write == NULL)
3020                         break;  /*! \todo XXX should return 0 maybe ? */
3021
3022                 /* If audiohooks are present, write the frame out */
3023                 if (chan->audiohooks) {
3024                         struct ast_frame *old_frame = fr;
3025                         fr = ast_audiohook_write_list(chan, chan->audiohooks, AST_AUDIOHOOK_DIRECTION_WRITE, fr);
3026                         if (old_frame != fr)
3027                                 f2 = fr;
3028                 }
3029
3030                 /* If the frame is in the raw write format, then it's easy... just use the frame - otherwise we will have to translate */
3031                 if (fr->subclass == chan->rawwriteformat)
3032                         f = fr;
3033                 else
3034                         f = (chan->writetrans) ? ast_translate(chan->writetrans, fr, 0) : fr;
3035
3036                 if (!f) {
3037                         res = 0;
3038                         break;
3039                 }
3040
3041                 /* If Monitor is running on this channel, then we have to write frames out there too */
3042                 if (chan->monitor && chan->monitor->write_stream) {
3043                         /* XXX must explain this code */
3044 #ifndef MONITOR_CONSTANT_DELAY
3045                         int jump = chan->insmpl - chan->outsmpl - 4 * f->samples;
3046                         if (jump >= 0) {
3047                                 jump = chan->insmpl - chan->outsmpl;
3048                                 if (ast_seekstream(chan->monitor->write_stream, jump, SEEK_FORCECUR) == -1)
3049                                         ast_log(LOG_WARNING, "Failed to perform seek in monitoring write stream, synchronization between the files may be broken\n");
3050                                 chan->outsmpl += jump + f->samples;
3051                         } else
3052                                 chan->outsmpl += f->samples;
3053 #else
3054                         int jump = chan->insmpl - chan->outsmpl;
3055                         if (jump - MONITOR_DELAY >= 0) {
3056                                 if (ast_seekstream(chan->monitor->write_stream, jump - f->samples, SEEK_FORCECUR) == -1)
3057                                         ast_log(LOG_WARNING, "Failed to perform seek in monitoring write stream, synchronization between the files may be broken\n");
3058                                 chan->outsmpl += jump;
3059                         } else
3060                                 chan->outsmpl += f->samples;
3061 #endif
3062                         if (chan->monitor->state == AST_MONITOR_RUNNING) {
3063                                 if (ast_writestream(chan->monitor->write_stream, f) < 0)
3064                                         ast_log(LOG_WARNING, "Failed to write data to channel monitor write stream\n");
3065                         }
3066                 }
3067
3068                 if (f) 
3069                         res = chan->tech->write(chan,f);
3070                 else
3071                         res = 0;
3072                 break;
3073         case AST_FRAME_NULL:
3074         case AST_FRAME_IAX:
3075                 /* Ignore these */
3076                 res = 0;
3077                 break;
3078         default:
3079                 /* At this point, fr is the incoming frame and f is NULL.  Channels do
3080                  * not expect to get NULL as a frame pointer and will segfault.  Hence,
3081                  * we output the original frame passed in. */
3082                 res = chan->tech->write(cha