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(const 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         ast_copy_string(tmp->exten, data, sizeof(tmp->exten));
 441         opts = strchr(tmp->exten, '/');
 442         if (opts) {
 443                 *opts++ = '\0';
 444                 if (strchr(opts, 'n'))
 445                         tmp->nooptimization = 1;
 446         }
 447         c = strchr(tmp->exten, '@');
 448         if (c)
 449                 *c++ = '\0';
 450         ast_copy_string(tmp->context, c ? c : "default", sizeof(tmp->context));
 451         tmp->reqformat = format;
 452         if (!ast_exists_extension(NULL, tmp->context, tmp->exten, 1, NULL)) {
 453                 ast_log(LOG_NOTICE, "No such extension/context %s@%s creating local channel\n", tmp->exten, tmp->context);
 454                 ast_mutex_destroy(&tmp->lock);
 455                 free(tmp);
 456                 tmp = NULL;
 457         } else {
 458                 /* Add to list */
 459                 AST_LIST_LOCK(&locals);
 460                 AST_LIST_INSERT_HEAD(&locals, tmp, list);
 461                 AST_LIST_UNLOCK(&locals);
 462         }
 463
 464         return tmp;
 465 }
 466
 467 /*! \brief Start new local channel */
 468 static struct ast_channel *local_new(struct local_pvt *p, int state)
 469 {
 470         struct ast_channel *tmp, *tmp2;
 471         int randnum = ast_random() & 0xffff;
 472
 473         tmp = ast_channel_alloc(1);
 474         tmp2 = ast_channel_alloc(1);
 475         if (!tmp || !tmp2) {
 476                 if (tmp)
 477                         ast_channel_free(tmp);
 478                 if (tmp2)
 479                         ast_channel_free(tmp2);
 480                 ast_log(LOG_WARNING, "Unable to allocate channel structure(s)\n");
 481                 return NULL;
 482         }
 483
 484         tmp2->tech = tmp->tech = &local_tech;
 485         tmp->nativeformats = p->reqformat;
 486         tmp2->nativeformats = p->reqformat;
 487         ast_string_field_build(tmp, name, "Local/%s@%s-%04x,1", p->exten, p->context, randnum);
 488         ast_string_field_build(tmp2, name, "Local/%s@%s-%04x,2", p->exten, p->context, randnum);
 489         ast_setstate(tmp, state);
 490         ast_setstate(tmp2, AST_STATE_RING);
 491         tmp->writeformat = p->reqformat;
 492         tmp2->writeformat = p->reqformat;
 493         tmp->rawwriteformat = p->reqformat;
 494         tmp2->rawwriteformat = p->reqformat;
 495         tmp->readformat = p->reqformat;
 496         tmp2->readformat = p->reqformat;
 497         tmp->rawreadformat = p->reqformat;
 498         tmp2->rawreadformat = p->reqformat;
 499         tmp->tech_pvt = p;
 500         tmp2->tech_pvt = p;
 501         p->owner = tmp;
 502         p->chan = tmp2;
 503         ast_atomic_fetchadd_int(&__mod_desc->usecnt, +2);       /* we allocate 2 new channels */
 504         ast_update_use_count();
 505         ast_copy_string(tmp->context, p->context, sizeof(tmp->context));
 506         ast_copy_string(tmp2->context, p->context, sizeof(tmp2->context));
 507         ast_copy_string(tmp2->exten, p->exten, sizeof(tmp->exten));
 508         tmp->priority = 1;
 509         tmp2->priority = 1;
 510
 511         return tmp;
 512 }
 513
 514
 515 /*! \brief Part of PBX interface */
 516 static struct ast_channel *local_request(const char *type, int format, void *data, int *cause)
 517 {
 518         struct local_pvt *p;
 519         struct ast_channel *chan = NULL;
 520
 521         p = local_alloc(data, format);
 522         if (p)
 523                 chan = local_new(p, AST_STATE_DOWN);
 524         return chan;
 525 }
 526
 527 /*! \brief CLI command "local show channels" */
 528 static int locals_show(int fd, int argc, char **argv)
 529 {
 530         struct local_pvt *p;
 531
 532         if (argc != 3)
 533                 return RESULT_SHOWUSAGE;
 534         if (AST_LIST_EMPTY(&locals))
 535                 ast_cli(fd, "No local channels in use\n");
 536         AST_LIST_LOCK(&locals);
 537         AST_LIST_TRAVERSE(&locals, p, list) {
 538                 ast_mutex_lock(&p->lock);
 539                 ast_cli(fd, "%s -- %s@%s\n", p->owner ? p->owner->name : "<unowned>", p->exten, p->context);
 540                 ast_mutex_unlock(&p->lock);
 541         }
 542         AST_LIST_UNLOCK(&locals);
 543         return RESULT_SUCCESS;
 544 }
 545
 546 static char show_locals_usage[] =
 547 "Usage: local show channels\n"
 548 "       Provides summary information on active local proxy channels.\n";
 549
 550 static struct ast_cli_entry cli_show_locals = {
 551         { "local", "show", "channels", NULL }, locals_show,
 552         "Show status of local channels", show_locals_usage, NULL };
 553
 554 /*! \brief Load module into PBX, register channel */
 555 static int load_module(void *mod)
 556 {
 557         __mod_desc = mod;
 558
 559         /* Make sure we can register our channel type */
 560         if (ast_channel_register(&local_tech)) {
 561                 ast_log(LOG_ERROR, "Unable to register channel class 'Local'\n");
 562                 return -1;
 563         }
 564         ast_cli_register(&cli_show_locals);
 565         return 0;
 566 }
 567
 568 /*! \brief Unload the local proxy channel from Asterisk */
 569 static int unload_module(void *mod)
 570 {
 571         struct local_pvt *p;
 572
 573         /* First, take us out of the channel loop */
 574         ast_cli_unregister(&cli_show_locals);
 575         ast_channel_unregister(&local_tech);
 576         if (!AST_LIST_LOCK(&locals)) {
 577                 /* Hangup all interfaces if they have an owner */
 578                 AST_LIST_TRAVERSE(&locals, p, list) {
 579                         if (p->owner)
 580                                 ast_softhangup(p->owner, AST_SOFTHANGUP_APPUNLOAD);
 581                 }
 582                 AST_LIST_UNLOCK(&locals);
 583                 AST_LIST_HEAD_DESTROY(&locals);
 584         } else {
 585                 ast_log(LOG_WARNING, "Unable to lock the monitor\n");
 586                 return -1;
 587         }
 588         return 0;
 589 }
 590
 591 static const char *key(void)
 592 {
 593         return ASTERISK_GPL_KEY;
 594 }
 595
 596 static const char *description(void)
 597 {
 598         return "Local Proxy Channel";
 599 }
 600
 601 STD_MOD(MOD_1, NULL, NULL, NULL);