channels/chan_local.c

   1 /*
   2  * Asterisk -- A telephony toolkit for Linux.
   3  *
   4  * Local Proxy Channel
   5  *
   6  * Copyright (C) 1999, Mark Spencer
   7  *
   8  * Mark Spencer <markster@linux-support.net>
   9  *
  10  * This program is free software, distributed under the terms of
  11  * the GNU General Public License
  12  */
  13
  14 #include <stdio.h>
  15 #include <pthread.h>
  16 #include <string.h>
  17 #include <asterisk/lock.h>
  18 #include <asterisk/channel.h>
  19 #include <asterisk/channel_pvt.h>
  20 #include <asterisk/config.h>
  21 #include <asterisk/logger.h>
  22 #include <asterisk/module.h>
  23 #include <asterisk/pbx.h>
  24 #include <asterisk/options.h>
  25 #include <asterisk/lock.h>
  26 #include <asterisk/sched.h>
  27 #include <asterisk/io.h>
  28 #include <asterisk/rtp.h>
  29 #include <asterisk/acl.h>
  30 #include <asterisk/callerid.h>
  31 #include <asterisk/file.h>
  32 #include <asterisk/cli.h>
  33 #include <asterisk/app.h>
  34 #include <asterisk/musiconhold.h>
  35 #include <asterisk/manager.h>
  36 #include <sys/socket.h>
  37 #include <errno.h>
  38 #include <unistd.h>
  39 #include <stdlib.h>
  40 #include <fcntl.h>
  41 #include <netdb.h>
  42 #include <arpa/inet.h>
  43 #include <sys/signal.h>
  44
  45 static char *desc = "Local Proxy Channel";
  46 static char *type = "Local";
  47 static char *tdesc = "Local Proxy Channel Driver";
  48
  49 static int capability = -1;
  50
  51 static int usecnt =0;
  52 static ast_mutex_t usecnt_lock = AST_MUTEX_INITIALIZER;
  53
  54 #define IS_OUTBOUND(a,b) (a == b->chan ? 1 : 0)
  55
  56 /* Protect the interface list (of sip_pvt's) */
  57 static ast_mutex_t locallock = AST_MUTEX_INITIALIZER;
  58
  59 static struct local_pvt {
  60         ast_mutex_t lock;                               /* Channel private lock */
  61         char context[AST_MAX_EXTENSION];        /* Context to call */
  62         char exten[AST_MAX_EXTENSION];          /* Extension to call */
  63         int reqformat;                                          /* Requested format */
  64         int glaredetect;                                        /* Detect glare on hangup */
  65         int cancelqueue;                                        /* Cancel queue */
  66         int alreadymasqed;                                      /* Already masqueraded */
  67         int launchedpbx;                                        /* Did we launch the PBX */
  68         int nooptimization;
  69         struct ast_channel *owner;                      /* Master Channel */
  70         struct ast_channel *chan;                       /* Outbound channel */
  71         struct local_pvt *next;                         /* Next entity */
  72 } *locals = NULL;
  73
  74 static int local_queue_frame(struct local_pvt *p, int isoutbound, struct ast_frame *f, struct ast_channel *us)
  75 {
  76         struct ast_channel *other;
  77 retrylock:
  78         /* Recalculate outbound channel */
  79         if (isoutbound) {
  80                 other = p->owner;
  81         } else {
  82                 other = p->chan;
  83         }
  84         /* Set glare detection */
  85         p->glaredetect = 1;
  86         if (p->cancelqueue) {
  87                 /* We had a glare on the hangup.  Forget all this business,
  88                 return and destroy p.  */
  89                 ast_mutex_unlock(&p->lock);
  90                 free(p);
  91                 return -1;
  92         }
  93         if (!other) {
  94                 p->glaredetect = 0;
  95                 return 0;
  96         }
  97         if (ast_mutex_trylock(&other->lock)) {
  98                 /* Failed to lock.  Release main lock and try again */
  99                 ast_mutex_unlock(&p->lock);
 100                 if (us) {
 101                         if (ast_mutex_unlock(&us->lock)) {
 102                                 ast_log(LOG_WARNING, "%s wasn't locked while sending %d/%d\n",
 103                                         us->name, f->frametype, f->subclass);
 104                                 us = NULL;
 105                         }
 106                 }
 107                 /* Wait just a bit */
 108                 usleep(1);
 109                 /* Only we can destroy ourselves, so we can't disappear here */
 110                 if (us)
 111                         ast_mutex_lock(&us->lock);
 112                 ast_mutex_lock(&p->lock);
 113                 goto retrylock;
 114         }
 115         ast_queue_frame(other, f);
 116         ast_mutex_unlock(&other->lock);
 117         p->glaredetect = 0;
 118         return 0;
 119 }
 120
 121 static int local_answer(struct ast_channel *ast)
 122 {
 123         struct local_pvt *p = ast->pvt->pvt;
 124         int isoutbound = IS_OUTBOUND(ast, p);
 125         int res = -1;
 126         ast_mutex_lock(&p->lock);
 127         if (isoutbound) {
 128                 /* Pass along answer since somebody answered us */
 129                 struct ast_frame answer = { AST_FRAME_CONTROL, AST_CONTROL_ANSWER };
 130                 res = local_queue_frame(p, isoutbound, &answer, ast);
 131         } else
 132                 ast_log(LOG_WARNING, "Huh?  Local is being asked to answer?\n");
 133         ast_mutex_unlock(&p->lock);
 134         return res;
 135 }
 136
 137 static void check_bridge(struct local_pvt *p, int isoutbound)
 138 {
 139         if (p->alreadymasqed || p->nooptimization)
 140                 return;
 141         if (isoutbound && p->chan && p->chan->bridge && p->owner) {
 142                 /* Masquerade bridged channel into owner */
 143                 /* Lock everything we need, one by one, and give up if
 144                    we can't get everything.  Remember, we'll get another
 145                    chance in just a little bit */
 146                 if (!ast_mutex_trylock(&p->chan->bridge->lock)) {
 147                         if (!ast_mutex_trylock(&p->owner->lock)) {
 148                                 ast_channel_masquerade(p->owner, p->chan->bridge);
 149                                 p->alreadymasqed = 1;
 150                                 ast_mutex_unlock(&p->owner->lock);
 151                         }
 152                         ast_mutex_unlock(&p->chan->bridge->lock);
 153                 }
 154         } else if (!isoutbound && p->owner && p->owner->bridge && p->chan) {
 155                 /* Masquerade bridged channel into chan */
 156                 if (!ast_mutex_trylock(&p->owner->bridge->lock)) {
 157                         if (!ast_mutex_trylock(&p->chan->lock)) {
 158                                 ast_channel_masquerade(p->chan, p->owner->bridge);
 159                                 p->alreadymasqed = 1;
 160                                 ast_mutex_unlock(&p->chan->lock);
 161                         }
 162                         ast_mutex_unlock(&p->owner->bridge->lock);
 163                 }
 164         }
 165 }
 166
 167 static struct ast_frame  *local_read(struct ast_channel *ast)
 168 {
 169         static struct ast_frame null = { AST_FRAME_NULL, };
 170         return &null;
 171 }
 172
 173 static int local_write(struct ast_channel *ast, struct ast_frame *f)
 174 {
 175         struct local_pvt *p = ast->pvt->pvt;
 176         int res = -1;
 177         int isoutbound = IS_OUTBOUND(ast, p);
 178
 179
 180         /* Just queue for delivery to the other side */
 181         ast_mutex_lock(&p->lock);
 182         res = local_queue_frame(p, isoutbound, f, ast);
 183         check_bridge(p, isoutbound);
 184         ast_mutex_unlock(&p->lock);
 185         return res;
 186 }
 187
 188 static int local_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
 189 {
 190         struct local_pvt *p = newchan->pvt->pvt;
 191         ast_mutex_lock(&p->lock);
 192         if ((p->owner != oldchan) && (p->chan != oldchan)) {
 193                 ast_log(LOG_WARNING, "old channel wasn't %p but was %p/%p\n", oldchan, p->owner, p->chan);
 194                 ast_mutex_unlock(&p->lock);
 195                 return -1;
 196         }
 197         if (p->owner == oldchan)
 198                 p->owner = newchan;
 199         else
 200                 p->chan = newchan;
 201         ast_mutex_unlock(&p->lock);
 202         return 0;
 203 }
 204
 205 static int local_indicate(struct ast_channel *ast, int condition)
 206 {
 207         struct local_pvt *p = ast->pvt->pvt;
 208         int res = -1;
 209         struct ast_frame f = { AST_FRAME_CONTROL, };
 210         int isoutbound = IS_OUTBOUND(ast, p);
 211         /* Queue up a frame representing the indication as a control frame */
 212         ast_mutex_lock(&p->lock);
 213         f.subclass = condition;
 214         res = local_queue_frame(p, isoutbound, &f, ast);
 215         ast_mutex_unlock(&p->lock);
 216         return res;
 217 }
 218
 219 static int local_digit(struct ast_channel *ast, char digit)
 220 {
 221         struct local_pvt *p = ast->pvt->pvt;
 222         int res = -1;
 223         struct ast_frame f = { AST_FRAME_DTMF, };
 224         int isoutbound = IS_OUTBOUND(ast, p);
 225         ast_mutex_lock(&p->lock);
 226         f.subclass = digit;
 227         res = local_queue_frame(p, isoutbound, &f, ast);
 228         ast_mutex_unlock(&p->lock);
 229         return res;
 230 }
 231
 232 static int local_call(struct ast_channel *ast, char *dest, int timeout)
 233 {
 234         struct local_pvt *p = ast->pvt->pvt;
 235         int res;
 236
 237         ast_mutex_lock(&p->lock);
 238         if (p->owner->callerid)
 239                 p->chan->callerid = strdup(p->owner->callerid);
 240         else
 241                 p->chan->callerid = NULL;
 242         if (p->owner->rdnis)
 243                 p->chan->rdnis = strdup(p->owner->rdnis);
 244         else
 245                 p->chan->rdnis = NULL;
 246         if (p->owner->ani)
 247                 p->chan->ani = strdup(p->owner->ani);
 248         else
 249                 p->chan->ani = NULL;
 250         p->launchedpbx = 1;
 251         /* Start switch on sub channel */
 252         res = ast_pbx_start(p->chan);
 253         ast_mutex_unlock(&p->lock);
 254         return res;
 255 }
 256
 257 /*
 258 static void local_destroy(struct local_pvt *p)
 259 {
 260         struct local_pvt *cur, *prev = NULL;
 261         ast_mutex_lock(&locallock);
 262         cur = locals;
 263         while(cur) {
 264                 if (cur == p) {
 265                         if (prev)
 266                                 prev->next = cur->next;
 267                         else
 268                                 locals = cur->next;
 269                         free(cur);
 270                         break;
 271                 }
 272                 prev = cur;
 273                 cur = cur->next;
 274         }
 275         ast_mutex_unlock(&locallock);
 276         if (!cur)
 277                 ast_log(LOG_WARNING, "Unable ot find local '%s@%s' in local list\n", p->exten, p->context);
 278 }
 279 */
 280
 281 static int local_hangup(struct ast_channel *ast)
 282 {
 283         struct local_pvt *p = ast->pvt->pvt;
 284         int isoutbound = IS_OUTBOUND(ast, p);
 285         struct ast_frame f = { AST_FRAME_CONTROL, AST_CONTROL_HANGUP };
 286         struct local_pvt *cur, *prev=NULL;
 287         struct ast_channel *ochan = NULL;
 288         int glaredetect;
 289         ast_mutex_lock(&p->lock);
 290         if (isoutbound) {
 291                 p->chan = NULL;
 292                 p->launchedpbx = 0;
 293         } else
 294                 p->owner = NULL;
 295         ast->pvt->pvt = NULL;
 296
 297         if (!p->owner && !p->chan) {
 298                 /* Okay, done with the private part now, too. */
 299                 glaredetect = p->glaredetect;
 300                 /* If we have a queue holding, don't actually destroy p yet, but
 301                    let local_queue do it. */
 302                 if (p->glaredetect)
 303                         p->cancelqueue = 1;
 304                 ast_mutex_unlock(&p->lock);
 305                 /* Remove from list */
 306                 ast_mutex_lock(&locallock);
 307                 cur = locals;
 308                 while(cur) {
 309                         if (cur == p) {
 310                                 if (prev)
 311                                         prev->next = cur->next;
 312                                 else
 313                                         locals = cur->next;
 314                                 break;
 315                         }
 316                         prev = cur;
 317                         cur = cur->next;
 318                 }
 319                 ast_mutex_unlock(&locallock);
 320                 /* And destroy */
 321                 if (!glaredetect)
 322                         free(p);
 323                 return 0;
 324         }
 325         if (p->chan && !p->launchedpbx)
 326                 /* Need to actually hangup since there is no PBX */
 327                 ochan = p->chan;
 328         else
 329                 local_queue_frame(p, isoutbound, &f, NULL);
 330         ast_mutex_unlock(&p->lock);
 331         if (ochan)
 332                 ast_hangup(ochan);
 333         return 0;
 334 }
 335
 336 static struct local_pvt *local_alloc(char *data, int format)
 337 {
 338         struct local_pvt *tmp;
 339         char *c;
 340         char *opts;
 341         tmp = malloc(sizeof(struct local_pvt));
 342         if (tmp) {
 343                 memset(tmp, 0, sizeof(struct local_pvt));
 344                 ast_mutex_init(&tmp->lock);
 345                 strncpy(tmp->exten, data, sizeof(tmp->exten) - 1);
 346                 opts = strchr(tmp->exten, '/');
 347                 if (opts) {
 348                         *opts='\0';
 349                         opts++;
 350                         if (strchr(opts, 'n'))
 351                                 tmp->nooptimization = 1;
 352                 }
 353                 c = strchr(tmp->exten, '@');
 354                 if (c) {
 355                         *c = '\0';
 356                         c++;
 357                         strncpy(tmp->context, c, sizeof(tmp->context) - 1);
 358                 } else
 359                         strncpy(tmp->context, "default", sizeof(tmp->context) - 1);
 360                 tmp->reqformat = format;
 361                 if (!ast_exists_extension(NULL, tmp->context, tmp->exten, 1, NULL)) {
 362                         ast_log(LOG_NOTICE, "No such extension/context %s@%s creating local channel\n", tmp->context, tmp->exten);
 363                         free(tmp);
 364                         tmp = NULL;
 365                 } else {
 366                         /* Add to list */
 367                         ast_mutex_lock(&locallock);
 368                         tmp->next = locals;
 369                         locals = tmp;
 370                         ast_mutex_unlock(&locallock);
 371                 }
 372
 373         }
 374         return tmp;
 375 }
 376
 377 static struct ast_channel *local_new(struct local_pvt *p, int state)
 378 {
 379         struct ast_channel *tmp, *tmp2;
 380         int randnum = rand() & 0xffff;
 381         tmp = ast_channel_alloc(1);
 382         tmp2 = ast_channel_alloc(1);
 383         if (!tmp || !tmp2) {
 384                 if (tmp)
 385                         ast_channel_free(tmp);
 386                 if (tmp2)
 387                         ast_channel_free(tmp2);
 388                 tmp = NULL;
 389         }
 390         if (tmp) {
 391                 tmp->nativeformats = p->reqformat;
 392                 tmp2->nativeformats = p->reqformat;
 393                 snprintf(tmp->name, sizeof(tmp->name), "Local/%s@%s-%04x,1", p->exten, p->context, randnum);
 394                 snprintf(tmp2->name, sizeof(tmp2->name), "Local/%s@%s-%04x,2", p->exten, p->context, randnum);
 395                 tmp->type = type;
 396                 tmp2->type = type;
 397                 ast_setstate(tmp, state);
 398                 ast_setstate(tmp2, AST_STATE_RING);
 399                 tmp->writeformat = p->reqformat;;
 400                 tmp2->writeformat = p->reqformat;
 401                 tmp->pvt->rawwriteformat = p->reqformat;
 402                 tmp2->pvt->rawwriteformat = p->reqformat;
 403                 tmp->readformat = p->reqformat;
 404                 tmp2->readformat = p->reqformat;
 405                 tmp->pvt->rawreadformat = p->reqformat;
 406                 tmp2->pvt->rawreadformat = p->reqformat;
 407                 tmp->pvt->pvt = p;
 408                 tmp2->pvt->pvt = p;
 409                 tmp->pvt->send_digit = local_digit;
 410                 tmp2->pvt->send_digit = local_digit;
 411                 tmp->pvt->call = local_call;
 412                 tmp2->pvt->call = local_call;
 413                 tmp->pvt->hangup = local_hangup;
 414                 tmp2->pvt->hangup = local_hangup;
 415                 tmp->pvt->answer = local_answer;
 416                 tmp2->pvt->answer = local_answer;
 417                 tmp->pvt->read = local_read;
 418                 tmp2->pvt->read = local_read;
 419                 tmp->pvt->write = local_write;
 420                 tmp2->pvt->write = local_write;
 421                 tmp->pvt->exception = local_read;
 422                 tmp2->pvt->exception = local_read;
 423                 tmp->pvt->indicate = local_indicate;
 424                 tmp2->pvt->indicate = local_indicate;
 425                 tmp->pvt->fixup = local_fixup;
 426                 tmp2->pvt->fixup = local_fixup;
 427                 p->owner = tmp;
 428                 p->chan = tmp2;
 429                 ast_mutex_lock(&usecnt_lock);
 430                 usecnt++;
 431                 ast_mutex_unlock(&usecnt_lock);
 432                 ast_update_use_count();
 433                 strncpy(tmp->context, p->context, sizeof(tmp->context)-1);
 434                 strncpy(tmp2->context, p->context, sizeof(tmp2->context)-1);
 435                 strncpy(tmp2->exten, p->exten, sizeof(tmp->exten)-1);
 436                 tmp->priority = 1;
 437                 tmp2->priority = 1;
 438         } else
 439                 ast_log(LOG_WARNING, "Unable to allocate channel structure\n");
 440         return tmp;
 441 }
 442
 443
 444 static struct ast_channel *local_request(char *type, int format, void *data)
 445 {
 446         struct local_pvt *p;
 447         struct ast_channel *chan = NULL;
 448         p = local_alloc(data, format);
 449         if (p)
 450                 chan = local_new(p, AST_STATE_DOWN);
 451         return chan;
 452 }
 453
 454 static int locals_show(int fd, int argc, char **argv)
 455 {
 456         struct local_pvt *p;
 457
 458         if (argc != 3)
 459                 return RESULT_SHOWUSAGE;
 460         ast_mutex_lock(&locallock);
 461         p = locals;
 462         while(p) {
 463                 ast_mutex_lock(&p->lock);
 464                 ast_cli(fd, "%s -- %s@%s\n", p->owner ? p->owner->name : "<unowned>", p->exten, p->context);
 465                 ast_mutex_unlock(&p->lock);
 466                 p = p->next;
 467         }
 468         if (!locals)
 469                 ast_cli(fd, "No local channels in use\n");
 470         ast_mutex_unlock(&locallock);
 471         return RESULT_SUCCESS;
 472 }
 473
 474 static char show_locals_usage[] =
 475 "Usage: local show channels\n"
 476 "       Provides summary information on local channels.\n";
 477
 478 static struct ast_cli_entry cli_show_locals = {
 479         { "local", "show", "channels", NULL }, locals_show,
 480         "Show status of local channels", show_locals_usage, NULL };
 481
 482 int load_module()
 483 {
 484         /* Make sure we can register our sip channel type */
 485         if (ast_channel_register(type, tdesc, capability, local_request)) {
 486                 ast_log(LOG_ERROR, "Unable to register channel class %s\n", type);
 487                 return -1;
 488         }
 489         ast_cli_register(&cli_show_locals);
 490         return 0;
 491 }
 492
 493 int reload()
 494 {
 495         return 0;
 496 }
 497
 498 int unload_module()
 499 {
 500         struct local_pvt *p;
 501         /* First, take us out of the channel loop */
 502         ast_cli_unregister(&cli_show_locals);
 503         ast_channel_unregister(type);
 504         if (!ast_mutex_lock(&locallock)) {
 505                 /* Hangup all interfaces if they have an owner */
 506                 p = locals;
 507                 while(p) {
 508                         if (p->owner)
 509                                 ast_softhangup(p->owner, AST_SOFTHANGUP_APPUNLOAD);
 510                         p = p->next;
 511                 }
 512                 locals = NULL;
 513                 ast_mutex_unlock(&locallock);
 514         } else {
 515                 ast_log(LOG_WARNING, "Unable to lock the monitor\n");
 516                 return -1;
 517         }
 518         return 0;
 519 }
 520
 521 int usecount()
 522 {
 523         int res;
 524         ast_mutex_lock(&usecnt_lock);
 525         res = usecnt;
 526         ast_mutex_unlock(&usecnt_lock);
 527         return res;
 528 }
 529
 530 char *key()
 531 {
 532         return ASTERISK_GPL_KEY;
 533 }
 534
 535 char *description()
 536 {
 537         return desc;
 538 }
 539