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 pthread_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 pthread_mutex_t locallock = AST_MUTEX_INITIALIZER;
  58
  59 static struct local_pvt {
  60         pthread_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 alreadymasqed;                                      /* Already masqueraded */
  65         struct ast_channel *owner;                      /* Master Channel */
  66         struct ast_channel *chan;                       /* Outbound channel */
  67         struct local_pvt *next;                         /* Next entity */
  68 } *locals = NULL;
  69
  70 static int local_queue_frame(struct local_pvt *p, int isoutbound, struct ast_frame *f)
  71 {
  72         struct ast_channel *other;
  73         if (isoutbound)
  74                 other = p->owner;
  75         else
  76                 other = p->chan;
  77         if (!other)
  78                 return 0;
  79 retrylock:
  80         if (pthread_mutex_trylock(&other->lock)) {
  81                 /* Failed to lock.  Release main lock and try again */
  82                 ast_pthread_mutex_unlock(&p->lock);
  83                 /* Wait just a bit */
  84                 usleep(1);
  85                 ast_pthread_mutex_lock(&p->lock);
  86                 goto retrylock;
  87         }
  88         ast_queue_frame(other, f, 0);
  89         ast_pthread_mutex_unlock(&other->lock);
  90         return 0;
  91 }
  92
  93 static int local_answer(struct ast_channel *ast)
  94 {
  95         struct local_pvt *p = ast->pvt->pvt;
  96         int isoutbound = IS_OUTBOUND(ast, p);
  97         int res = -1;
  98         ast_pthread_mutex_lock(&p->lock);
  99         if (isoutbound) {
 100                 /* Pass along answer since somebody answered us */
 101                 struct ast_frame answer = { AST_FRAME_CONTROL, AST_CONTROL_ANSWER };
 102                 res = local_queue_frame(p, isoutbound, &answer);
 103         } else
 104                 ast_log(LOG_WARNING, "Huh?  Local is being asked to answer?\n");
 105         ast_pthread_mutex_unlock(&p->lock);
 106         return res;
 107 }
 108
 109 static void check_bridge(struct local_pvt *p, int isoutbound)
 110 {
 111         if (p->alreadymasqed)
 112                 return;
 113         if (isoutbound && p->chan && p->chan->bridge && p->owner) {
 114                 /* Masquerade bridged channel into owner */
 115                 ast_channel_masquerade(p->owner, p->chan->bridge);
 116                 p->alreadymasqed = 1;
 117         } else if (!isoutbound && p->owner && p->owner->bridge && p->chan) {
 118                 /* Masquerade bridged channel into chan */
 119                 ast_channel_masquerade(p->chan, p->owner->bridge);
 120                 p->alreadymasqed = 1;
 121         }
 122 }
 123
 124 static struct ast_frame  *local_read(struct ast_channel *ast)
 125 {
 126         static struct ast_frame null = { AST_FRAME_NULL, };
 127         return &null;
 128 }
 129
 130 static int local_write(struct ast_channel *ast, struct ast_frame *f)
 131 {
 132         struct local_pvt *p = ast->pvt->pvt;
 133         int res = -1;
 134         int isoutbound = IS_OUTBOUND(ast, p);
 135
 136
 137         /* Just queue for delivery to the other side */
 138         ast_pthread_mutex_lock(&p->lock);
 139         res = local_queue_frame(p, isoutbound, f);
 140         check_bridge(p, isoutbound);
 141         ast_pthread_mutex_unlock(&p->lock);
 142         return res;
 143 }
 144
 145 static int local_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
 146 {
 147         struct local_pvt *p = newchan->pvt->pvt;
 148         ast_pthread_mutex_lock(&p->lock);
 149         if ((p->owner != oldchan) && (p->chan != oldchan)) {
 150                 ast_log(LOG_WARNING, "old channel wasn't %p but was %p/%p\n", oldchan, p->owner, p->chan);
 151                 ast_pthread_mutex_unlock(&p->lock);
 152                 return -1;
 153         }
 154         if (p->owner == oldchan)
 155                 p->owner = newchan;
 156         else
 157                 p->chan = newchan;
 158         ast_pthread_mutex_unlock(&p->lock);
 159         return 0;
 160 }
 161
 162 static int local_indicate(struct ast_channel *ast, int condition)
 163 {
 164         struct local_pvt *p = ast->pvt->pvt;
 165         int res = -1;
 166         struct ast_frame f = { AST_FRAME_CONTROL, };
 167         int isoutbound = IS_OUTBOUND(ast, p);
 168         /* Queue up a frame representing the indication as a control frame */
 169         ast_pthread_mutex_lock(&p->lock);
 170         f.subclass = condition;
 171         res = local_queue_frame(p, isoutbound, &f);
 172         ast_pthread_mutex_unlock(&p->lock);
 173         return res;
 174 }
 175
 176 static int local_digit(struct ast_channel *ast, char digit)
 177 {
 178         struct local_pvt *p = ast->pvt->pvt;
 179         int res = -1;
 180         struct ast_frame f = { AST_FRAME_DTMF, };
 181         int isoutbound = IS_OUTBOUND(ast, p);
 182         ast_pthread_mutex_lock(&p->lock);
 183         f.subclass = digit;
 184         res = local_queue_frame(p, isoutbound, &f);
 185         ast_pthread_mutex_unlock(&p->lock);
 186         return res;
 187 }
 188
 189 static int local_call(struct ast_channel *ast, char *dest, int timeout)
 190 {
 191         struct local_pvt *p = ast->pvt->pvt;
 192         /* Start switch on sub channel */
 193         return ast_pbx_start(p->chan);
 194 }
 195
 196 static void local_destroy(struct local_pvt *p)
 197 {
 198         struct local_pvt *cur, *prev = NULL;
 199         ast_pthread_mutex_lock(&locallock);
 200         cur = locals;
 201         while(cur) {
 202                 if (cur == p) {
 203                         if (prev)
 204                                 prev->next = cur->next;
 205                         else
 206                                 locals = cur->next;
 207                         free(cur);
 208                         break;
 209                 }
 210                 prev = cur;
 211                 cur = cur->next;
 212         }
 213         ast_pthread_mutex_unlock(&locallock);
 214         if (!cur)
 215                 ast_log(LOG_WARNING, "Unable ot find local '%s@%s' in local list\n", p->exten, p->context);
 216 }
 217
 218 static int local_hangup(struct ast_channel *ast)
 219 {
 220         struct local_pvt *p = ast->pvt->pvt;
 221         int isoutbound = IS_OUTBOUND(ast, p);
 222         struct ast_frame f = { AST_FRAME_CONTROL, AST_CONTROL_HANGUP };
 223         struct local_pvt *cur, *prev=NULL;
 224         ast_pthread_mutex_lock(&p->lock);
 225         if (isoutbound)
 226                 p->chan = NULL;
 227         else
 228                 p->owner = NULL;
 229         ast->pvt->pvt = NULL;
 230         if (!p->owner && !p->chan) {
 231                 /* Okay, done with the private part now, too. */
 232                 ast_pthread_mutex_unlock(&p->lock);
 233                 /* Remove from list */
 234                 ast_pthread_mutex_lock(&locallock);
 235                 cur = locals;
 236                 while(cur) {
 237                         if (cur == p) {
 238                                 if (prev)
 239                                         prev->next == cur->next;
 240                                 else
 241                                         locals = cur->next;
 242                                 break;
 243                         }
 244                         prev = cur;
 245                         cur = cur->next;
 246                 }
 247                 ast_pthread_mutex_unlock(&locallock);
 248                 /* And destroy */
 249                 free(p);
 250                 return 0;
 251         }
 252         local_queue_frame(p, isoutbound, &f);
 253         ast_pthread_mutex_unlock(&p->lock);
 254         return 0;
 255 }
 256
 257 static struct local_pvt *local_alloc(char *data, int format)
 258 {
 259         struct local_pvt *tmp;
 260         char *c;
 261         tmp = malloc(sizeof(struct local_pvt));
 262         if (tmp) {
 263                 memset(tmp, 0, sizeof(struct local_pvt));
 264                 ast_pthread_mutex_init(&tmp->lock);
 265                 strncpy(tmp->exten, data, sizeof(tmp->exten) - 1);
 266                 c = strchr(tmp->exten, '@');
 267                 if (c) {
 268                         *c = '\0';
 269                         c++;
 270                         strncpy(tmp->context, c, sizeof(tmp->context) - 1);
 271                 } else
 272                         strncpy(tmp->context, "default", sizeof(tmp->context) - 1);
 273                 tmp->reqformat = format;
 274                 if (!ast_exists_extension(NULL, tmp->context, tmp->exten, 1, NULL)) {
 275                         ast_log(LOG_NOTICE, "No such extension/context %s@%s creating local channel\n", tmp->context, tmp->exten);
 276                         free(tmp);
 277                         tmp = NULL;
 278                 } else {
 279                         /* Add to list */
 280                         ast_pthread_mutex_lock(&locallock);
 281                         tmp->next = locals;
 282                         locals = tmp;
 283                         ast_pthread_mutex_unlock(&locallock);
 284                 }
 285
 286         }
 287         return tmp;
 288 }
 289
 290 static struct ast_channel *local_new(struct local_pvt *p, int state)
 291 {
 292         struct ast_channel *tmp, *tmp2;
 293         tmp = ast_channel_alloc(1);
 294         tmp2 = ast_channel_alloc(1);
 295         if (!tmp || !tmp2) {
 296                 if (tmp)
 297                         ast_channel_free(tmp);
 298                 if (tmp2)
 299                         ast_channel_free(tmp2);
 300                 tmp = NULL;
 301         }
 302         if (tmp) {
 303                 tmp->nativeformats = p->reqformat;
 304                 tmp2->nativeformats = p->reqformat;
 305                 snprintf(tmp->name, sizeof(tmp->name), "Local/%s@%s-1", p->exten, p->context);
 306                 snprintf(tmp2->name, sizeof(tmp2->name), "Local/%s@%s-2", p->exten, p->context);
 307                 tmp->type = type;
 308                 tmp2->type = type;
 309                 ast_setstate(tmp, state);
 310                 ast_setstate(tmp2, AST_STATE_RING);
 311                 tmp->writeformat = p->reqformat;;
 312                 tmp2->writeformat = p->reqformat;
 313                 tmp->pvt->rawwriteformat = p->reqformat;
 314                 tmp2->pvt->rawwriteformat = p->reqformat;
 315                 tmp->readformat = p->reqformat;
 316                 tmp2->readformat = p->reqformat;
 317                 tmp->pvt->rawreadformat = p->reqformat;
 318                 tmp2->pvt->rawreadformat = p->reqformat;
 319                 tmp->pvt->pvt = p;
 320                 tmp2->pvt->pvt = p;
 321                 tmp->pvt->send_digit = local_digit;
 322                 tmp2->pvt->send_digit = local_digit;
 323                 tmp->pvt->call = local_call;
 324                 tmp2->pvt->call = local_call;
 325                 tmp->pvt->hangup = local_hangup;
 326                 tmp2->pvt->hangup = local_hangup;
 327                 tmp->pvt->answer = local_answer;
 328                 tmp2->pvt->answer = local_answer;
 329                 tmp->pvt->read = local_read;
 330                 tmp2->pvt->read = local_read;
 331                 tmp->pvt->write = local_write;
 332                 tmp2->pvt->write = local_write;
 333                 tmp->pvt->exception = local_read;
 334                 tmp2->pvt->exception = local_read;
 335                 tmp->pvt->indicate = local_indicate;
 336                 tmp2->pvt->indicate = local_indicate;
 337                 tmp->pvt->fixup = local_fixup;
 338                 tmp2->pvt->fixup = local_fixup;
 339                 p->owner = tmp;
 340                 p->chan = tmp2;
 341                 ast_pthread_mutex_lock(&usecnt_lock);
 342                 usecnt++;
 343                 ast_pthread_mutex_unlock(&usecnt_lock);
 344                 ast_update_use_count();
 345                 strncpy(tmp->context, p->context, sizeof(tmp->context)-1);
 346                 strncpy(tmp2->context, p->context, sizeof(tmp2->context)-1);
 347                 strncpy(tmp2->exten, p->exten, sizeof(tmp->exten)-1);
 348                 tmp->priority = 1;
 349                 tmp2->priority = 1;
 350         } else
 351                 ast_log(LOG_WARNING, "Unable to allocate channel structure\n");
 352         return tmp;
 353 }
 354
 355
 356 static struct ast_channel *local_request(char *type, int format, void *data)
 357 {
 358         struct local_pvt *p;
 359         struct ast_channel *chan = NULL;
 360         p = local_alloc(data, format);
 361         if (p)
 362                 chan = local_new(p, AST_STATE_DOWN);
 363         return chan;
 364 }
 365
 366 static int locals_show(int fd, int argc, char **argv)
 367 {
 368         struct local_pvt *p;
 369
 370         if (argc != 2)
 371                 return RESULT_SHOWUSAGE;
 372         ast_pthread_mutex_lock(&locallock);
 373         p = locals;
 374         while(p) {
 375                 ast_pthread_mutex_lock(&p->lock);
 376                 ast_cli(fd, "%s -- %s@%s\n", p->owner ? p->owner->name : "<unowned>", p->exten, p->context);
 377                 ast_pthread_mutex_unlock(&p->lock);
 378                 p = p->next;
 379         }
 380         if (!locals)
 381                 ast_cli(fd, "No local channels in use\n");
 382         ast_pthread_mutex_unlock(&locallock);
 383         return RESULT_SUCCESS;
 384 }
 385
 386 static char show_locals_usage[] =
 387 "Usage: show locals\n"
 388 "       Provides summary information on locals.\n";
 389
 390 static struct ast_cli_entry cli_show_locals = {
 391         { "show", "locals", NULL }, locals_show,
 392         "Show status of local channels", show_locals_usage, NULL };
 393
 394 int load_module()
 395 {
 396         /* Make sure we can register our sip channel type */
 397         if (ast_channel_register(type, tdesc, capability, local_request)) {
 398                 ast_log(LOG_ERROR, "Unable to register channel class %s\n", type);
 399                 return -1;
 400         }
 401         ast_cli_register(&cli_show_locals);
 402         return 0;
 403 }
 404
 405 int reload()
 406 {
 407         return 0;
 408 }
 409
 410 int unload_module()
 411 {
 412         struct local_pvt *p;
 413         /* First, take us out of the channel loop */
 414         ast_cli_unregister(&cli_show_locals);
 415         ast_channel_unregister(type);
 416         if (!ast_pthread_mutex_lock(&locallock)) {
 417                 /* Hangup all interfaces if they have an owner */
 418                 p = locals;
 419                 while(p) {
 420                         if (p->owner)
 421                                 ast_softhangup(p->owner, AST_SOFTHANGUP_APPUNLOAD);
 422                         p = p->next;
 423                 }
 424                 locals = NULL;
 425                 ast_pthread_mutex_unlock(&locallock);
 426         } else {
 427                 ast_log(LOG_WARNING, "Unable to lock the monitor\n");
 428                 return -1;
 429         }
 430         return 0;
 431 }
 432
 433 int usecount()
 434 {
 435         int res;
 436         ast_pthread_mutex_lock(&usecnt_lock);
 437         res = usecnt;
 438         ast_pthread_mutex_unlock(&usecnt_lock);
 439         return res;
 440 }
 441
 442 char *key()
 443 {
 444         return ASTERISK_GPL_KEY;
 445 }
 446
 447 char *description()
 448 {
 449         return desc;
 450 }
 451