5705dc905fbbdad0daceef9be49b65635dfbec87
[asterisk/asterisk.git] / channels / chan_local.c
1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 1999 - 2005, 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  * \author Mark Spencer <markster@digium.com>
22  *
23  * \brief Local Proxy Channel
24  * 
25  * \ingroup channel_drivers
26  */
27
28 #include <stdio.h>
29 #include <string.h>
30 #include <unistd.h>
31 #include <sys/socket.h>
32 #include <errno.h>
33 #include <stdlib.h>
34 #include <fcntl.h>
35 #include <netdb.h>
36 #include <netinet/in.h>
37 #include <arpa/inet.h>
38 #include <sys/signal.h>
39
40 #include "asterisk.h"
41
42 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
43
44 #include "asterisk/lock.h"
45 #include "asterisk/channel.h"
46 #include "asterisk/config.h"
47 #include "asterisk/logger.h"
48 #include "asterisk/module.h"
49 #include "asterisk/pbx.h"
50 #include "asterisk/options.h"
51 #include "asterisk/lock.h"
52 #include "asterisk/sched.h"
53 #include "asterisk/io.h"
54 #include "asterisk/rtp.h"
55 #include "asterisk/acl.h"
56 #include "asterisk/callerid.h"
57 #include "asterisk/file.h"
58 #include "asterisk/cli.h"
59 #include "asterisk/app.h"
60 #include "asterisk/musiconhold.h"
61 #include "asterisk/manager.h"
62 #include "asterisk/stringfields.h"
63
64 static const char tdesc[] = "Local Proxy Channel Driver";
65
66 #define IS_OUTBOUND(a,b) (a == b->chan ? 1 : 0)
67
68 static struct ast_channel *local_request(const char *type, int format, void *data, int *cause);
69 static int local_digit(struct ast_channel *ast, char digit);
70 static int local_call(struct ast_channel *ast, char *dest, int timeout);
71 static int local_hangup(struct ast_channel *ast);
72 static int local_answer(struct ast_channel *ast);
73 static struct ast_frame *local_read(struct ast_channel *ast);
74 static int local_write(struct ast_channel *ast, struct ast_frame *f);
75 static int local_indicate(struct ast_channel *ast, int condition);
76 static int local_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
77 static int local_sendhtml(struct ast_channel *ast, int subclass, const char *data, int datalen);
78
79 /* PBX interface structure for channel registration */
80 static const struct ast_channel_tech local_tech = {
81         .type = "Local",
82         .description = tdesc,
83         .capabilities = -1,
84         .requester = local_request,
85         .send_digit = local_digit,
86         .call = local_call,
87         .hangup = local_hangup,
88         .answer = local_answer,
89         .read = local_read,
90         .write = local_write,
91         .exception = local_read,
92         .indicate = local_indicate,
93         .fixup = local_fixup,
94         .send_html = local_sendhtml,
95 };
96
97 struct local_pvt {
98         ast_mutex_t lock;                       /* Channel private lock */
99         char context[AST_MAX_CONTEXT];          /* Context to call */
100         char exten[AST_MAX_EXTENSION];          /* Extension to call */
101         int reqformat;                          /* Requested format */
102         int glaredetect;                        /* Detect glare on hangup */
103         int cancelqueue;                        /* Cancel queue */
104         int alreadymasqed;                      /* Already masqueraded */
105         int launchedpbx;                        /* Did we launch the PBX */
106         int nooptimization;                     /* Don't leave masq state */
107         struct ast_channel *owner;              /* Master Channel */
108         struct ast_channel *chan;               /* Outbound channel */
109         AST_LIST_ENTRY(local_pvt) list;         /* Next entity */
110 };
111
112 static AST_LIST_HEAD_STATIC(locals, local_pvt);
113
114 static int local_queue_frame(struct local_pvt *p, int isoutbound, struct ast_frame *f, struct ast_channel *us)
115 {
116         struct ast_channel *other;
117 retrylock:              
118         /* Recalculate outbound channel */
119         if (isoutbound) {
120                 other = p->owner;
121         } else {
122                 other = p->chan;
123         }
124         /* Set glare detection */
125         p->glaredetect = 1;
126         if (p->cancelqueue) {
127                 /* We had a glare on the hangup.  Forget all this business,
128                 return and destroy p.  */
129                 ast_mutex_unlock(&p->lock);
130                 ast_mutex_destroy(&p->lock);
131                 free(p);
132                 return -1;
133         }
134         if (!other) {
135                 p->glaredetect = 0;
136                 return 0;
137         }
138         if (ast_mutex_trylock(&other->lock)) {
139                 /* Failed to lock.  Release main lock and try again */
140                 ast_mutex_unlock(&p->lock);
141                 if (us) {
142                         if (ast_mutex_unlock(&us->lock)) {
143                                 ast_log(LOG_WARNING, "%s wasn't locked while sending %d/%d\n",
144                                         us->name, f->frametype, f->subclass);
145                                 us = NULL;
146                         }
147                 }
148                 /* Wait just a bit */
149                 usleep(1);
150                 /* Only we can destroy ourselves, so we can't disappear here */
151                 if (us)
152                         ast_mutex_lock(&us->lock);
153                 ast_mutex_lock(&p->lock);
154                 goto retrylock;
155         }
156         ast_queue_frame(other, f);
157         ast_mutex_unlock(&other->lock);
158         p->glaredetect = 0;
159         return 0;
160 }
161
162 static int local_answer(struct ast_channel *ast)
163 {
164         struct local_pvt *p = ast->tech_pvt;
165         int isoutbound;
166         int res = -1;
167
168         ast_mutex_lock(&p->lock);
169         isoutbound = IS_OUTBOUND(ast, p);
170         if (isoutbound) {
171                 /* Pass along answer since somebody answered us */
172                 struct ast_frame answer = { AST_FRAME_CONTROL, AST_CONTROL_ANSWER };
173                 res = local_queue_frame(p, isoutbound, &answer, ast);
174         } else
175                 ast_log(LOG_WARNING, "Huh?  Local is being asked to answer?\n");
176         ast_mutex_unlock(&p->lock);
177         return res;
178 }
179
180 static void check_bridge(struct local_pvt *p, int isoutbound)
181 {
182         if (p->alreadymasqed || p->nooptimization)
183                 return;
184         if (!p->chan || !p->owner)
185                 return;
186         if (isoutbound&& p->chan->_bridge /* Not ast_bridged_channel!  Only go one step! */ && !p->owner->readq) {
187                 /* Masquerade bridged channel into owner */
188                 /* Lock everything we need, one by one, and give up if
189                    we can't get everything.  Remember, we'll get another
190                    chance in just a little bit */
191                 if (!ast_mutex_trylock(&(p->chan->_bridge)->lock)) {
192                         if (!p->chan->_bridge->_softhangup) {
193                                 if (!ast_mutex_trylock(&p->owner->lock)) {
194                                         if (!p->owner->_softhangup) {
195                                                 ast_channel_masquerade(p->owner, p->chan->_bridge);
196                                                 p->alreadymasqed = 1;
197                                         }
198                                         ast_mutex_unlock(&p->owner->lock);
199                                 }
200                                 ast_mutex_unlock(&(p->chan->_bridge)->lock);
201                         }
202                 }
203         } else if (!isoutbound && p->owner && p->owner->_bridge && p->chan && !p->chan->readq) {
204                 /* Masquerade bridged channel into chan */
205                 if (!ast_mutex_trylock(&(p->owner->_bridge)->lock)) {
206                         if (!p->owner->_bridge->_softhangup) {
207                                 if (!ast_mutex_trylock(&p->chan->lock)) {
208                                         if (!p->chan->_softhangup) {
209                                                 ast_channel_masquerade(p->chan, p->owner->_bridge);
210                                                 p->alreadymasqed = 1;
211                                         }
212                                         ast_mutex_unlock(&p->chan->lock);
213                                 }
214                         }
215                         ast_mutex_unlock(&(p->owner->_bridge)->lock);
216                 }
217         }
218 }
219
220 static struct ast_frame  *local_read(struct ast_channel *ast)
221 {
222         return &ast_null_frame;
223 }
224
225 static int local_write(struct ast_channel *ast, struct ast_frame *f)
226 {
227         struct local_pvt *p = ast->tech_pvt;
228         int res = -1;
229         int isoutbound;
230
231         /* Just queue for delivery to the other side */
232         ast_mutex_lock(&p->lock);
233         isoutbound = IS_OUTBOUND(ast, p);
234         if (f && (f->frametype == AST_FRAME_VOICE)) 
235                 check_bridge(p, isoutbound);
236         if (!p->alreadymasqed)
237                 res = local_queue_frame(p, isoutbound, f, ast);
238         else {
239                 ast_log(LOG_DEBUG, "Not posting to queue since already masked on '%s'\n", ast->name);
240                 res = 0;
241         }
242         ast_mutex_unlock(&p->lock);
243         return res;
244 }
245
246 static int local_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
247 {
248         struct local_pvt *p = newchan->tech_pvt;
249         ast_mutex_lock(&p->lock);
250
251         if ((p->owner != oldchan) && (p->chan != oldchan)) {
252                 ast_log(LOG_WARNING, "Old channel wasn't %p but was %p/%p\n", oldchan, p->owner, p->chan);
253                 ast_mutex_unlock(&p->lock);
254                 return -1;
255         }
256         if (p->owner == oldchan)
257                 p->owner = newchan;
258         else
259                 p->chan = newchan;
260         ast_mutex_unlock(&p->lock);
261         return 0;
262 }
263
264 static int local_indicate(struct ast_channel *ast, int condition)
265 {
266         struct local_pvt *p = ast->tech_pvt;
267         int res = -1;
268         struct ast_frame f = { AST_FRAME_CONTROL, };
269         int isoutbound;
270
271         /* Queue up a frame representing the indication as a control frame */
272         ast_mutex_lock(&p->lock);
273         isoutbound = IS_OUTBOUND(ast, p);
274         f.subclass = condition;
275         res = local_queue_frame(p, isoutbound, &f, ast);
276         ast_mutex_unlock(&p->lock);
277         return res;
278 }
279
280 static int local_digit(struct ast_channel *ast, char digit)
281 {
282         struct local_pvt *p = ast->tech_pvt;
283         int res = -1;
284         struct ast_frame f = { AST_FRAME_DTMF, };
285         int isoutbound;
286
287         ast_mutex_lock(&p->lock);
288         isoutbound = IS_OUTBOUND(ast, p);
289         f.subclass = digit;
290         res = local_queue_frame(p, isoutbound, &f, ast);
291         ast_mutex_unlock(&p->lock);
292         return res;
293 }
294
295 static int local_sendhtml(struct ast_channel *ast, int subclass, const char *data, int datalen)
296 {
297         struct local_pvt *p = ast->tech_pvt;
298         int res = -1;
299         struct ast_frame f = { AST_FRAME_HTML, };
300         int isoutbound;
301
302         ast_mutex_lock(&p->lock);
303         isoutbound = IS_OUTBOUND(ast, p);
304         f.subclass = subclass;
305         f.data = (char *)data;
306         f.datalen = datalen;
307         res = local_queue_frame(p, isoutbound, &f, ast);
308         ast_mutex_unlock(&p->lock);
309         return res;
310 }
311
312 /*! \brief Initiate new call, part of PBX interface 
313  *      dest is the dial string */
314 static int local_call(struct ast_channel *ast, char *dest, int timeout)
315 {
316         struct local_pvt *p = ast->tech_pvt;
317         int res;
318         struct ast_var_t *varptr = NULL, *new;
319         size_t len, namelen;
320         
321         ast_mutex_lock(&p->lock);
322
323         p->chan->cid.cid_num = ast_strdup(p->owner->cid.cid_num);
324         p->chan->cid.cid_name = ast_strdup(p->owner->cid.cid_name);
325         p->chan->cid.cid_rdnis = ast_strdup(p->owner->cid.cid_rdnis);
326         p->chan->cid.cid_ani = ast_strdup(p->owner->cid.cid_ani);
327
328         ast_string_field_set(p->chan, language, p->owner->language);
329         ast_string_field_set(p->chan, accountcode, p->owner->accountcode);
330         p->chan->cdrflags = p->owner->cdrflags;
331
332         /* copy the channel variables from the incoming channel to the outgoing channel */
333         /* Note that due to certain assumptions, they MUST be in the same order */
334         AST_LIST_TRAVERSE(&p->owner->varshead, varptr, entries) {
335                 namelen = strlen(varptr->name);
336                 len = sizeof(struct ast_var_t) + namelen + strlen(varptr->value) + 2;
337                 if ((new = ast_calloc(1, len))) {
338                         memcpy(new, varptr, len);
339                         new->value = &(new->name[0]) + namelen + 1;
340                         AST_LIST_INSERT_TAIL(&p->chan->varshead, new, entries);
341                 }
342         }
343
344         p->launchedpbx = 1;
345
346         /* Start switch on sub channel */
347         res = ast_pbx_start(p->chan);
348         ast_mutex_unlock(&p->lock);
349         return res;
350 }
351
352 #if 0
353 static void local_destroy(struct local_pvt *p)
354 {
355         struct local_pvt *cur;
356
357         AST_LIST_LOCK(&locals);
358         AST_LIST_TRAVERSE_SAFE_BEGIN(&locals, cur, list) {
359                 if (cur == p) {
360                         AST_LIST_REMOVE_CURRENT(&locals, list);
361                         ast_mutex_destroy(&cur->lock);
362                         free(cur);
363                         break;
364                 }
365         }
366         AST_LIST_TRAVERSE_SAFE_END
367         AST_LIST_UNLOCK(&locals);
368         if (!cur)
369                 ast_log(LOG_WARNING, "Unable ot find local '%s@%s' in local list\n", p->exten, p->context);
370 }
371 #endif
372
373 /*! \brief Hangup a call through the local proxy channel */
374 static int local_hangup(struct ast_channel *ast)
375 {
376         struct local_pvt *p = ast->tech_pvt;
377         int isoutbound;
378         struct ast_frame f = { AST_FRAME_CONTROL, AST_CONTROL_HANGUP };
379         struct ast_channel *ochan = NULL;
380         int glaredetect;
381
382         ast_mutex_lock(&p->lock);
383         isoutbound = IS_OUTBOUND(ast, p);
384         if (isoutbound) {
385                 const char *status = pbx_builtin_getvar_helper(p->chan, "DIALSTATUS");
386                 if ((status) && (p->owner))
387                         pbx_builtin_setvar_helper(p->owner, "CHANLOCALSTATUS", status);
388                 p->chan = NULL;
389                 p->launchedpbx = 0;
390         } else
391                 p->owner = NULL;
392         ast->tech_pvt = NULL;
393         
394         ast_atomic_fetchadd_int(&__mod_desc->usecnt, -1);
395         
396         if (!p->owner && !p->chan) {
397                 /* Okay, done with the private part now, too. */
398                 glaredetect = p->glaredetect;
399                 /* If we have a queue holding, don't actually destroy p yet, but
400                    let local_queue do it. */
401                 if (p->glaredetect)
402                         p->cancelqueue = 1;
403                 ast_mutex_unlock(&p->lock);
404                 /* Remove from list */
405                 AST_LIST_LOCK(&locals);
406                 AST_LIST_REMOVE(&locals, p, list);
407                 AST_LIST_UNLOCK(&locals);
408                 /* Grab / release lock just in case */
409                 ast_mutex_lock(&p->lock);
410                 ast_mutex_unlock(&p->lock);
411                 /* And destroy */
412                 if (!glaredetect) {
413                         ast_mutex_destroy(&p->lock);
414                         free(p);
415                 }
416                 return 0;
417         }
418         if (p->chan && !p->launchedpbx)
419                 /* Need to actually hangup since there is no PBX */
420                 ochan = p->chan;
421         else
422                 local_queue_frame(p, isoutbound, &f, NULL);
423         ast_mutex_unlock(&p->lock);
424         if (ochan)
425                 ast_hangup(ochan);
426         return 0;
427 }
428
429 /*! \brief Create a call structure */
430 static struct local_pvt *local_alloc(char *data, int format)
431 {
432         struct local_pvt *tmp;
433         char *c;
434         char *opts;
435
436         if (!(tmp = ast_calloc(1, sizeof(*tmp))))
437                 return NULL;
438         
439         ast_mutex_init(&tmp->lock);
440         strncpy(tmp->exten, data, sizeof(tmp->exten) - 1);
441         opts = strchr(tmp->exten, '/');
442         if (opts) {
443                 *opts='\0';
444                 opts++;
445                 if (strchr(opts, 'n'))
446                         tmp->nooptimization = 1;
447         }
448         c = strchr(tmp->exten, '@');
449         if (c) {
450                 *c = '\0';
451                 c++;
452                 strncpy(tmp->context, c, sizeof(tmp->context) - 1);
453         } else
454                 strncpy(tmp->context, "default", sizeof(tmp->context) - 1);
455         tmp->reqformat = format;
456         if (!ast_exists_extension(NULL, tmp->context, tmp->exten, 1, NULL)) {
457                 ast_log(LOG_NOTICE, "No such extension/context %s@%s creating local channel\n", tmp->exten, tmp->context);
458                 ast_mutex_destroy(&tmp->lock);
459                 free(tmp);
460                 tmp = NULL;
461         } else {
462                 /* Add to list */
463                 AST_LIST_LOCK(&locals);
464                 AST_LIST_INSERT_HEAD(&locals, tmp, list);
465                 AST_LIST_UNLOCK(&locals);
466         }
467         
468         return tmp;
469 }
470
471 /*! \brief Start new local channel */
472 static struct ast_channel *local_new(struct local_pvt *p, int state)
473 {
474         struct ast_channel *tmp, *tmp2;
475         int randnum = ast_random() & 0xffff;
476
477         tmp = ast_channel_alloc(1);
478         tmp2 = ast_channel_alloc(1);
479         if (!tmp || !tmp2) {
480                 if (tmp)
481                         ast_channel_free(tmp);
482                 if (tmp2)
483                         ast_channel_free(tmp2);
484                 ast_log(LOG_WARNING, "Unable to allocate channel structure(s)\n");
485                 return NULL;
486         } 
487
488         tmp2->tech = tmp->tech = &local_tech;
489         tmp->nativeformats = p->reqformat;
490         tmp2->nativeformats = p->reqformat;
491         ast_string_field_build(tmp, name, "Local/%s@%s-%04x,1", p->exten, p->context, randnum);
492         ast_string_field_build(tmp2, name, "Local/%s@%s-%04x,2", p->exten, p->context, randnum);
493         ast_setstate(tmp, state);
494         ast_setstate(tmp2, AST_STATE_RING);
495         tmp->writeformat = p->reqformat;
496         tmp2->writeformat = p->reqformat;
497         tmp->rawwriteformat = p->reqformat;
498         tmp2->rawwriteformat = p->reqformat;
499         tmp->readformat = p->reqformat;
500         tmp2->readformat = p->reqformat;
501         tmp->rawreadformat = p->reqformat;
502         tmp2->rawreadformat = p->reqformat;
503         tmp->tech_pvt = p;
504         tmp2->tech_pvt = p;
505         p->owner = tmp;
506         p->chan = tmp2;
507         ast_atomic_fetchadd_int(&__mod_desc->usecnt, +2);       /* we allocate 2 new channels */
508         ast_update_use_count();
509         ast_copy_string(tmp->context, p->context, sizeof(tmp->context));
510         ast_copy_string(tmp2->context, p->context, sizeof(tmp2->context));
511         ast_copy_string(tmp2->exten, p->exten, sizeof(tmp->exten));
512         tmp->priority = 1;
513         tmp2->priority = 1;
514
515         return tmp;
516 }
517
518
519 /*! \brief Part of PBX interface */
520 static struct ast_channel *local_request(const char *type, int format, void *data, int *cause)
521 {
522         struct local_pvt *p;
523         struct ast_channel *chan = NULL;
524
525         p = local_alloc(data, format);
526         if (p)
527                 chan = local_new(p, AST_STATE_DOWN);
528         return chan;
529 }
530
531 /*! \brief CLI command "local show channels" */
532 static int locals_show(int fd, int argc, char **argv)
533 {
534         struct local_pvt *p;
535
536         if (argc != 3)
537                 return RESULT_SHOWUSAGE;
538         if (AST_LIST_EMPTY(&locals))
539                 ast_cli(fd, "No local channels in use\n");
540         AST_LIST_LOCK(&locals);
541         AST_LIST_TRAVERSE(&locals, p, list) {
542                 ast_mutex_lock(&p->lock);
543                 ast_cli(fd, "%s -- %s@%s\n", p->owner ? p->owner->name : "<unowned>", p->exten, p->context);
544                 ast_mutex_unlock(&p->lock);
545         }
546         AST_LIST_UNLOCK(&locals);
547         return RESULT_SUCCESS;
548 }
549
550 static char show_locals_usage[] = 
551 "Usage: local show channels\n"
552 "       Provides summary information on active local proxy channels.\n";
553
554 static struct ast_cli_entry cli_show_locals = {
555         { "local", "show", "channels", NULL }, locals_show, 
556         "Show status of local channels", show_locals_usage, NULL };
557
558 /*! \brief Load module into PBX, register channel */
559 static int load_module(void *mod)
560 {
561         __mod_desc = mod;
562
563         /* Make sure we can register our channel type */
564         if (ast_channel_register(&local_tech)) {
565                 ast_log(LOG_ERROR, "Unable to register channel class 'Local'\n");
566                 return -1;
567         }
568         ast_cli_register(&cli_show_locals);
569         return 0;
570 }
571
572 /*! \brief Unload the local proxy channel from Asterisk */
573 static int unload_module(void *mod)
574 {
575         struct local_pvt *p;
576
577         /* First, take us out of the channel loop */
578         ast_cli_unregister(&cli_show_locals);
579         ast_channel_unregister(&local_tech);
580         if (!AST_LIST_LOCK(&locals)) {
581                 /* Hangup all interfaces if they have an owner */
582                 AST_LIST_TRAVERSE(&locals, p, list) {
583                         if (p->owner)
584                                 ast_softhangup(p->owner, AST_SOFTHANGUP_APPUNLOAD);
585                 }
586                 AST_LIST_UNLOCK(&locals);
587                 AST_LIST_HEAD_DESTROY(&locals);
588         } else {
589                 ast_log(LOG_WARNING, "Unable to lock the monitor\n");
590                 return -1;
591         }               
592         return 0;
593 }
594
595 static const char *key(void)
596 {
597         return ASTERISK_GPL_KEY;
598 }
599
600 static const char *description(void)
601 {
602         return "Local Proxy Channel";
603 }
604
605 STD_MOD(MOD_1, NULL, NULL, NULL);