channels/chan_features.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  * \brief feature Proxy Channel
  22  *
  23  * \author Mark Spencer <markster@digium.com>
  24  *
  25  * \note *** Experimental code ****
  26  *
  27  * \ingroup channel_drivers
  28  */
  29 /*** MODULEINFO
  30         <defaultenabled>no</defaultenabled>
  31  ***/
  32
  33 #include "asterisk.h"
  34
  35 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  36
  37 #include <fcntl.h>
  38 #include <sys/signal.h>
  39
  40 #include "asterisk/lock.h"
  41 #include "asterisk/channel.h"
  42 #include "asterisk/config.h"
  43 #include "asterisk/module.h"
  44 #include "asterisk/pbx.h"
  45 #include "asterisk/sched.h"
  46 #include "asterisk/io.h"
  47 #include "asterisk/rtp.h"
  48 #include "asterisk/acl.h"
  49 #include "asterisk/callerid.h"
  50 #include "asterisk/file.h"
  51 #include "asterisk/cli.h"
  52 #include "asterisk/app.h"
  53 #include "asterisk/musiconhold.h"
  54 #include "asterisk/manager.h"
  55 #include "asterisk/stringfields.h"
  56
  57 static const char tdesc[] = "Feature Proxy Channel Driver";
  58
  59 #define IS_OUTBOUND(a,b) (a == b->chan ? 1 : 0)
  60
  61 struct feature_sub {
  62         struct ast_channel *owner;
  63         int inthreeway;
  64         int pfd;
  65         int timingfdbackup;
  66         int alertpipebackup[2];
  67 };
  68
  69 struct feature_pvt {
  70         ast_mutex_t lock;                       /* Channel private lock */
  71         char tech[AST_MAX_EXTENSION];           /* Technology to abstract */
  72         char dest[AST_MAX_EXTENSION];           /* Destination to abstract */
  73         struct ast_channel *subchan;
  74         struct feature_sub subs[3];             /* Subs */
  75         struct ast_channel *owner;              /* Current Master Channel */
  76         AST_LIST_ENTRY(feature_pvt) list;       /* Next entity */
  77 };
  78
  79 static AST_LIST_HEAD_STATIC(features, feature_pvt);
  80
  81 #define SUB_REAL        0                       /* Active call */
  82 #define SUB_CALLWAIT    1                       /* Call-Waiting call on hold */
  83 #define SUB_THREEWAY    2                       /* Three-way call */
  84
  85 static struct ast_channel *features_request(const char *type, int format, void *data, int *cause);
  86 static int features_digit_begin(struct ast_channel *ast, char digit);
  87 static int features_digit_end(struct ast_channel *ast, char digit, unsigned int duration);
  88 static int features_call(struct ast_channel *ast, char *dest, int timeout);
  89 static int features_hangup(struct ast_channel *ast);
  90 static int features_answer(struct ast_channel *ast);
  91 static struct ast_frame *features_read(struct ast_channel *ast);
  92 static int features_write(struct ast_channel *ast, struct ast_frame *f);
  93 static int features_indicate(struct ast_channel *ast, int condition, const void *data, size_t datalen);
  94 static int features_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
  95
  96 static const struct ast_channel_tech features_tech = {
  97         .type = "Feature",
  98         .description = tdesc,
  99         .capabilities = -1,
 100         .requester = features_request,
 101         .send_digit_begin = features_digit_begin,
 102         .send_digit_end = features_digit_end,
 103         .call = features_call,
 104         .hangup = features_hangup,
 105         .answer = features_answer,
 106         .read = features_read,
 107         .write = features_write,
 108         .exception = features_read,
 109         .indicate = features_indicate,
 110         .fixup = features_fixup,
 111 };
 112
 113 static inline void init_sub(struct feature_sub *sub)
 114 {
 115         sub->inthreeway = 0;
 116         sub->pfd = -1;
 117         sub->timingfdbackup = -1;
 118         sub->alertpipebackup[0] = sub->alertpipebackup[1] = -1;
 119 }
 120
 121 static inline int indexof(struct feature_pvt *p, struct ast_channel *owner, int nullok)
 122 {
 123         int x;
 124         if (!owner) {
 125                 ast_log(LOG_WARNING, "indexof called on NULL owner??\n");
 126                 return -1;
 127         }
 128         for (x=0; x<3; x++) {
 129                 if (owner == p->subs[x].owner)
 130                         return x;
 131         }
 132         return -1;
 133 }
 134
 135 #if 0
 136 static void wakeup_sub(struct feature_pvt *p, int a)
 137 {
 138         struct ast_frame null = { AST_FRAME_NULL, };
 139         for (;;) {
 140                 if (p->subs[a].owner) {
 141                         if (ast_mutex_trylock(&p->subs[a].owner->lock)) {
 142                                 DEADLOCK_AVOIDANCE(&p->lock);
 143                         } else {
 144                                 ast_queue_frame(p->subs[a].owner, &null);
 145                                 ast_mutex_unlock(&p->subs[a].owner->lock);
 146                                 break;
 147                         }
 148                 } else
 149                         break;
 150         }
 151 }
 152 #endif
 153
 154 static void restore_channel(struct feature_pvt *p, int index)
 155 {
 156         /* Restore timing/alertpipe */
 157         p->subs[index].owner->timingfd = p->subs[index].timingfdbackup;
 158         p->subs[index].owner->alertpipe[0] = p->subs[index].alertpipebackup[0];
 159         p->subs[index].owner->alertpipe[1] = p->subs[index].alertpipebackup[1];
 160         ast_channel_set_fd(p->subs[index].owner, AST_ALERT_FD, p->subs[index].alertpipebackup[0]);
 161         ast_channel_set_fd(p->subs[index].owner, AST_TIMING_FD, p->subs[index].timingfdbackup);
 162 }
 163
 164 static void update_features(struct feature_pvt *p, int index)
 165 {
 166         int x;
 167         if (p->subs[index].owner) {
 168                 for (x=0; x<AST_MAX_FDS; x++) {
 169                         if (index)
 170                                 ast_channel_set_fd(p->subs[index].owner, x, -1);
 171                         else
 172                                 ast_channel_set_fd(p->subs[index].owner, x, p->subchan->fds[x]);
 173                 }
 174                 if (!index) {
 175                         /* Copy timings from master channel */
 176                         p->subs[index].owner->timingfd = p->subchan->timingfd;
 177                         p->subs[index].owner->alertpipe[0] = p->subchan->alertpipe[0];
 178                         p->subs[index].owner->alertpipe[1] = p->subchan->alertpipe[1];
 179                         if (p->subs[index].owner->nativeformats != p->subchan->readformat) {
 180                                 p->subs[index].owner->nativeformats = p->subchan->readformat;
 181                                 if (p->subs[index].owner->readformat)
 182                                         ast_set_read_format(p->subs[index].owner, p->subs[index].owner->readformat);
 183                                 if (p->subs[index].owner->writeformat)
 184                                         ast_set_write_format(p->subs[index].owner, p->subs[index].owner->writeformat);
 185                         }
 186                 } else{
 187                         restore_channel(p, index);
 188                 }
 189         }
 190 }
 191
 192 #if 0
 193 static void swap_subs(struct feature_pvt *p, int a, int b)
 194 {
 195         int tinthreeway;
 196         struct ast_channel *towner;
 197
 198         ast_debug(1, "Swapping %d and %d\n", a, b);
 199
 200         towner = p->subs[a].owner;
 201         tinthreeway = p->subs[a].inthreeway;
 202
 203         p->subs[a].owner = p->subs[b].owner;
 204         p->subs[a].inthreeway = p->subs[b].inthreeway;
 205
 206         p->subs[b].owner = towner;
 207         p->subs[b].inthreeway = tinthreeway;
 208         update_features(p,a);
 209         update_features(p,b);
 210         wakeup_sub(p, a);
 211         wakeup_sub(p, b);
 212 }
 213 #endif
 214
 215 static int features_answer(struct ast_channel *ast)
 216 {
 217         struct feature_pvt *p = ast->tech_pvt;
 218         int res = -1;
 219         int x;
 220
 221         ast_mutex_lock(&p->lock);
 222         x = indexof(p, ast, 0);
 223         if (!x && p->subchan)
 224                 res = ast_answer(p->subchan);
 225         ast_mutex_unlock(&p->lock);
 226         return res;
 227 }
 228
 229 static struct ast_frame  *features_read(struct ast_channel *ast)
 230 {
 231         struct feature_pvt *p = ast->tech_pvt;
 232         struct ast_frame *f;
 233         int x;
 234
 235         f = &ast_null_frame;
 236         ast_mutex_lock(&p->lock);
 237         x = indexof(p, ast, 0);
 238         if (!x && p->subchan) {
 239                 update_features(p, x);
 240                 f = ast_read(p->subchan);
 241         }
 242         ast_mutex_unlock(&p->lock);
 243         return f;
 244 }
 245
 246 static int features_write(struct ast_channel *ast, struct ast_frame *f)
 247 {
 248         struct feature_pvt *p = ast->tech_pvt;
 249         int res = -1;
 250         int x;
 251
 252         ast_mutex_lock(&p->lock);
 253         x = indexof(p, ast, 0);
 254         if (!x && p->subchan)
 255                 res = ast_write(p->subchan, f);
 256         ast_mutex_unlock(&p->lock);
 257         return res;
 258 }
 259
 260 static int features_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
 261 {
 262         struct feature_pvt *p = newchan->tech_pvt;
 263         int x;
 264
 265         ast_mutex_lock(&p->lock);
 266         if (p->owner == oldchan)
 267                 p->owner = newchan;
 268         for (x = 0; x < 3; x++) {
 269                 if (p->subs[x].owner == oldchan)
 270                         p->subs[x].owner = newchan;
 271         }
 272         ast_mutex_unlock(&p->lock);
 273         return 0;
 274 }
 275
 276 static int features_indicate(struct ast_channel *ast, int condition, const void *data, size_t datalen)
 277 {
 278         struct feature_pvt *p = ast->tech_pvt;
 279         int res = -1;
 280         int x;
 281
 282         /* Queue up a frame representing the indication as a control frame */
 283         ast_mutex_lock(&p->lock);
 284         x = indexof(p, ast, 0);
 285         if (!x && p->subchan)
 286                 res = ast_indicate(p->subchan, condition);
 287         ast_mutex_unlock(&p->lock);
 288         return res;
 289 }
 290
 291 static int features_digit_begin(struct ast_channel *ast, char digit)
 292 {
 293         struct feature_pvt *p = ast->tech_pvt;
 294         int res = -1;
 295         int x;
 296
 297         /* Queue up a frame representing the indication as a control frame */
 298         ast_mutex_lock(&p->lock);
 299         x = indexof(p, ast, 0);
 300         if (!x && p->subchan)
 301                 res = ast_senddigit_begin(p->subchan, digit);
 302         ast_mutex_unlock(&p->lock);
 303
 304         return res;
 305 }
 306
 307 static int features_digit_end(struct ast_channel *ast, char digit, unsigned int duration)
 308 {
 309         struct feature_pvt *p = ast->tech_pvt;
 310         int res = -1;
 311         int x;
 312
 313         /* Queue up a frame representing the indication as a control frame */
 314         ast_mutex_lock(&p->lock);
 315         x = indexof(p, ast, 0);
 316         if (!x && p->subchan)
 317                 res = ast_senddigit_end(p->subchan, digit, duration);
 318         ast_mutex_unlock(&p->lock);
 319         return res;
 320 }
 321
 322 static int features_call(struct ast_channel *ast, char *dest, int timeout)
 323 {
 324         struct feature_pvt *p = ast->tech_pvt;
 325         int res = -1;
 326         int x;
 327         char *dest2;
 328
 329         dest2 = strchr(dest, '/');
 330         if (dest2) {
 331                 ast_mutex_lock(&p->lock);
 332                 x = indexof(p, ast, 0);
 333                 if (!x && p->subchan) {
 334                         p->subchan->cid.cid_num = ast_strdup(p->owner->cid.cid_num);
 335                         p->subchan->cid.cid_name = ast_strdup(p->owner->cid.cid_name);
 336                         p->subchan->cid.cid_rdnis = ast_strdup(p->owner->cid.cid_rdnis);
 337                         p->subchan->cid.cid_ani = ast_strdup(p->owner->cid.cid_ani);
 338
 339                         p->subchan->cid.cid_pres = p->owner->cid.cid_pres;
 340                         ast_string_field_set(p->subchan, language, p->owner->language);
 341                         ast_string_field_set(p->subchan, accountcode, p->owner->accountcode);
 342                         p->subchan->cdrflags = p->owner->cdrflags;
 343                         res = ast_call(p->subchan, dest2, timeout);
 344                         update_features(p, x);
 345                 } else
 346                         ast_log(LOG_NOTICE, "Uhm yah, not quite there with the call waiting...\n");
 347                 ast_mutex_unlock(&p->lock);
 348         }
 349         return res;
 350 }
 351
 352 static int features_hangup(struct ast_channel *ast)
 353 {
 354         struct feature_pvt *p = ast->tech_pvt;
 355         int x;
 356
 357         ast_mutex_lock(&p->lock);
 358         x = indexof(p, ast, 0);
 359         if (x > -1) {
 360                 restore_channel(p, x);
 361                 p->subs[x].owner = NULL;
 362                 /* XXX Re-arrange, unconference, etc XXX */
 363         }
 364         ast->tech_pvt = NULL;
 365
 366         if (!p->subs[SUB_REAL].owner && !p->subs[SUB_CALLWAIT].owner && !p->subs[SUB_THREEWAY].owner) {
 367                 ast_mutex_unlock(&p->lock);
 368                 /* Remove from list */
 369                 AST_LIST_LOCK(&features);
 370                 AST_LIST_REMOVE(&features, p, list);
 371                 AST_LIST_UNLOCK(&features);
 372                 ast_mutex_lock(&p->lock);
 373                 /* And destroy */
 374                 if (p->subchan)
 375                         ast_hangup(p->subchan);
 376                 ast_mutex_unlock(&p->lock);
 377                 ast_mutex_destroy(&p->lock);
 378                 ast_free(p);
 379                 return 0;
 380         }
 381         ast_mutex_unlock(&p->lock);
 382         return 0;
 383 }
 384
 385 static struct feature_pvt *features_alloc(char *data, int format)
 386 {
 387         struct feature_pvt *tmp;
 388         char *dest=NULL;
 389         char *tech;
 390         int x;
 391         int status;
 392         struct ast_channel *chan;
 393
 394         tech = ast_strdupa(data);
 395         if (tech) {
 396                 dest = strchr(tech, '/');
 397                 if (dest) {
 398                         *dest = '\0';
 399                         dest++;
 400                 }
 401         }
 402         if (!tech || !dest) {
 403                 ast_log(LOG_NOTICE, "Format for feature channel is Feature/Tech/Dest ('%s' not valid)!\n",
 404                         data);
 405                 return NULL;
 406         }
 407         AST_LIST_LOCK(&features);
 408         AST_LIST_TRAVERSE(&features, tmp, list) {
 409                 if (!strcasecmp(tmp->tech, tech) && !strcmp(tmp->dest, dest))
 410                         break;
 411         }
 412         AST_LIST_UNLOCK(&features);
 413         if (!tmp) {
 414                 chan = ast_request(tech, format, dest, &status);
 415                 if (!chan) {
 416                         ast_log(LOG_NOTICE, "Unable to allocate subchannel '%s/%s'\n", tech, dest);
 417                         return NULL;
 418                 }
 419                 tmp = ast_calloc(1, sizeof(*tmp));
 420                 if (tmp) {
 421                         for (x=0;x<3;x++)
 422                                 init_sub(tmp->subs + x);
 423                         ast_mutex_init(&tmp->lock);
 424                         ast_copy_string(tmp->tech, tech, sizeof(tmp->tech));
 425                         ast_copy_string(tmp->dest, dest, sizeof(tmp->dest));
 426                         tmp->subchan = chan;
 427                         AST_LIST_LOCK(&features);
 428                         AST_LIST_INSERT_HEAD(&features, tmp, list);
 429                         AST_LIST_UNLOCK(&features);
 430                 }
 431         }
 432         return tmp;
 433 }
 434
 435 static struct ast_channel *features_new(struct feature_pvt *p, int state, int index)
 436 {
 437         struct ast_channel *tmp;
 438         int x,y;
 439         char *b2 = 0;
 440         if (!p->subchan) {
 441                 ast_log(LOG_WARNING, "Called upon channel with no subchan:(\n");
 442                 return NULL;
 443         }
 444         if (p->subs[index].owner) {
 445                 ast_log(LOG_WARNING, "Called to put index %d already there!\n", index);
 446                 return NULL;
 447         }
 448         /* figure out what you want the name to be */
 449         for (x=1;x<4;x++) {
 450                 if (b2)
 451                         ast_free(b2);
 452                 asprintf(&b2, "%s/%s-%d", p->tech, p->dest, x);
 453                 for (y=0;y<3;y++) {
 454                         if (y == index)
 455                                 continue;
 456                         if (p->subs[y].owner && !strcasecmp(p->subs[y].owner->name, b2))
 457                                 break;
 458                 }
 459                 if (y >= 3)
 460                         break;
 461         }
 462         tmp = ast_channel_alloc(0, state, 0,0, "", "", "", 0, "Feature/%s", b2);
 463         /* free up the name, it was copied into the channel name */
 464         if (b2)
 465                 ast_free(b2);
 466         if (!tmp) {
 467                 ast_log(LOG_WARNING, "Unable to allocate channel structure\n");
 468                 return NULL;
 469         }
 470         tmp->tech = &features_tech;
 471         tmp->writeformat = p->subchan->writeformat;
 472         tmp->rawwriteformat = p->subchan->rawwriteformat;
 473         tmp->readformat = p->subchan->readformat;
 474         tmp->rawreadformat = p->subchan->rawreadformat;
 475         tmp->nativeformats = p->subchan->readformat;
 476         tmp->tech_pvt = p;
 477         p->subs[index].owner = tmp;
 478         if (!p->owner)
 479                 p->owner = tmp;
 480         ast_module_ref(ast_module_info->self);
 481         return tmp;
 482 }
 483
 484
 485 static struct ast_channel *features_request(const char *type, int format, void *data, int *cause)
 486 {
 487         struct feature_pvt *p;
 488         struct ast_channel *chan = NULL;
 489
 490         p = features_alloc(data, format);
 491         if (p && !p->subs[SUB_REAL].owner)
 492                 chan = features_new(p, AST_STATE_DOWN, SUB_REAL);
 493         if (chan)
 494                 update_features(p,SUB_REAL);
 495         return chan;
 496 }
 497
 498 static char *features_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 499 {
 500         struct feature_pvt *p;
 501
 502         switch (cmd) {
 503         case CLI_INIT:
 504                 e->command = "feature show channels";
 505                 e->usage =
 506                         "Usage: feature show channels\n"
 507                         "       Provides summary information on feature channels.\n";
 508                 return NULL;
 509         case CLI_GENERATE:
 510                 return NULL;
 511         }
 512
 513         if (a->argc != 3)
 514                 return CLI_SHOWUSAGE;
 515
 516         if (AST_LIST_EMPTY(&features)) {
 517                 ast_cli(a->fd, "No feature channels in use\n");
 518                 return CLI_SUCCESS;
 519         }
 520
 521         AST_LIST_LOCK(&features);
 522         AST_LIST_TRAVERSE(&features, p, list) {
 523                 ast_mutex_lock(&p->lock);
 524                 ast_cli(a->fd, "%s -- %s/%s\n", p->owner ? p->owner->name : "<unowned>", p->tech, p->dest);
 525                 ast_mutex_unlock(&p->lock);
 526         }
 527         AST_LIST_UNLOCK(&features);
 528         return CLI_SUCCESS;
 529 }
 530
 531 static struct ast_cli_entry cli_features[] = {
 532         AST_CLI_DEFINE(features_show, "List status of feature channels"),
 533 };
 534
 535 static int load_module(void)
 536 {
 537         /* Make sure we can register our sip channel type */
 538         if (ast_channel_register(&features_tech)) {
 539                 ast_log(LOG_ERROR, "Unable to register channel class 'Feature'\n");
 540                 return AST_MODULE_LOAD_FAILURE;
 541         }
 542         ast_cli_register_multiple(cli_features, sizeof(cli_features) / sizeof(struct ast_cli_entry));
 543         return AST_MODULE_LOAD_SUCCESS;
 544 }
 545
 546 static int unload_module(void)
 547 {
 548         struct feature_pvt *p;
 549
 550         /* First, take us out of the channel loop */
 551         ast_cli_unregister_multiple(cli_features, sizeof(cli_features) / sizeof(struct ast_cli_entry));
 552         ast_channel_unregister(&features_tech);
 553
 554         if (!AST_LIST_LOCK(&features))
 555                 return -1;
 556         /* Hangup all interfaces if they have an owner */
 557         while ((p = AST_LIST_REMOVE_HEAD(&features, list))) {
 558                 if (p->owner)
 559                         ast_softhangup(p->owner, AST_SOFTHANGUP_APPUNLOAD);
 560                 ast_free(p);
 561         }
 562         AST_LIST_UNLOCK(&features);
 563
 564         return 0;
 565 }
 566
 567 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Feature Proxy Channel");
 568