codecs/codec_dahdi.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * DAHDI native transcoding support
   5  *
   6  * Copyright (C) 1999 - 2008, Digium, Inc.
   7  *
   8  * Mark Spencer <markster@digium.com>
   9  * Kevin P. Fleming <kpfleming@digium.com>
  10  *
  11  * See http://www.asterisk.org for more information about
  12  * the Asterisk project. Please do not directly contact
  13  * any of the maintainers of this project for assistance;
  14  * the project provides a web site, mailing lists and IRC
  15  * channels for your use.
  16  *
  17  * This program is free software, distributed under the terms of
  18  * the GNU General Public License Version 2. See the LICENSE file
  19  * at the top of the source tree.
  20  */
  21
  22 /*! \file
  23  *
  24  * \brief Translate between various formats natively through DAHDI transcoding
  25  *
  26  * \ingroup codecs
  27  */
  28
  29 /*** MODULEINFO
  30         <depend>dahdi</depend>
  31  ***/
  32
  33 #include "asterisk.h"
  34
  35 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  36
  37 #include <fcntl.h>
  38 #include <netinet/in.h>
  39 #include <sys/ioctl.h>
  40 #include <sys/mman.h>
  41
  42 #include <dahdi/user.h>
  43
  44 #include "asterisk/lock.h"
  45 #include "asterisk/translate.h"
  46 #include "asterisk/config.h"
  47 #include "asterisk/module.h"
  48 #include "asterisk/cli.h"
  49 #include "asterisk/channel.h"
  50 #include "asterisk/utils.h"
  51 #include "asterisk/linkedlists.h"
  52
  53 #define BUFFER_SAMPLES  8000
  54
  55 static unsigned int global_useplc = 0;
  56
  57 static struct channel_usage {
  58         int total;
  59         int encoders;
  60         int decoders;
  61 } channels;
  62
  63 static char *handle_cli_transcoder_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
  64
  65 static struct ast_cli_entry cli[] = {
  66         AST_CLI_DEFINE(handle_cli_transcoder_show, "Display DAHDI transcoder utilization.")
  67 };
  68
  69 struct format_map {
  70         unsigned int map[32][32];
  71 };
  72
  73 static struct format_map global_format_map = { { { 0 } } };
  74
  75 struct translator {
  76         struct ast_translator t;
  77         AST_LIST_ENTRY(translator) entry;
  78 };
  79
  80 static AST_LIST_HEAD_STATIC(translators, translator);
  81
  82 struct pvt {
  83         int fd;
  84         int fake;
  85         struct dahdi_transcoder_formats fmts;
  86         int samples;
  87 };
  88
  89 static char *handle_cli_transcoder_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
  90 {
  91         struct channel_usage copy;
  92
  93         switch (cmd) {
  94         case CLI_INIT:
  95                 e->command = "transcoder show";
  96                 e->usage =
  97                         "Usage: transcoder show\n"
  98                         "       Displays channel utilization of DAHDI transcoder(s).\n";
  99                 return NULL;
 100         case CLI_GENERATE:
 101                 return NULL;
 102         }
 103
 104         if (a->argc != 2)
 105                 return CLI_SHOWUSAGE;
 106
 107         copy = channels;
 108
 109         if (copy.total == 0)
 110                 ast_cli(a->fd, "No DAHDI transcoders found.\n");
 111         else
 112                 ast_cli(a->fd, "%d/%d encoders/decoders of %d channels are in use.\n", copy.encoders, copy.decoders, copy.total);
 113
 114         return CLI_SUCCESS;
 115 }
 116
 117 static int dahdi_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
 118 {
 119         int res;
 120         struct pvt *dahdip = pvt->pvt;
 121
 122         if (f->subclass) {
 123                 /* Give the frame to the hardware transcoder... */
 124                 res = write(dahdip->fd, f->data.ptr, f->datalen);
 125                 if (-1 == res) {
 126                         ast_log(LOG_ERROR, "Failed to write to /dev/dahdi/transcode: %s\n", strerror(errno));
 127                 }
 128                 if (f->datalen != res) {
 129                         ast_log(LOG_ERROR, "Requested write of %d bytes, but only wrote %d bytes.\n", f->datalen, res);
 130                 }
 131                 res = -1;
 132                 pvt->samples += f->samples;
 133         } else {
 134                 /* Fake a return frame for calculation purposes */
 135                 dahdip->fake = 2;
 136                 pvt->samples = f->samples;
 137                 res = 0;
 138         }
 139         return res;
 140 }
 141
 142 static struct ast_frame *dahdi_frameout(struct ast_trans_pvt *pvt)
 143 {
 144         struct pvt *dahdip = pvt->pvt;
 145
 146         if (0 == dahdip->fake) {
 147                 int res;
 148                 /* Let's check to see if there is a new frame for us.... */
 149                 res = read(dahdip->fd, pvt->outbuf.uc + pvt->datalen, pvt->t->buf_size - pvt->datalen);
 150                 if (-1 == res) {
 151                         if (EWOULDBLOCK == errno) {
 152                                 /* Nothing waiting... */
 153                                 return NULL;
 154                         } else {
 155                                 ast_log(LOG_ERROR, "Failed to read from /dev/dahdi/transcode: %s\n", strerror(errno));
 156                                 return NULL;
 157                         }
 158                 } else {
 159                         pvt->f.samples = dahdip->samples;
 160                         pvt->f.datalen = res;
 161                         pvt->datalen = 0;
 162                         pvt->f.frametype = AST_FRAME_VOICE;
 163                         pvt->f.subclass = 1 <<  (pvt->t->dstfmt);
 164                         pvt->f.mallocd = 0;
 165                         pvt->f.offset = AST_FRIENDLY_OFFSET;
 166                         pvt->f.src = pvt->t->name;
 167                         pvt->f.data.ptr = pvt->outbuf.uc;
 168                         ast_set_flag(&pvt->f, AST_FRFLAG_FROM_TRANSLATOR);
 169
 170                         return &pvt->f;
 171                 }
 172
 173         } else if (2 == dahdip->fake) {
 174
 175                 dahdip->fake = 1;
 176                 pvt->f.frametype = AST_FRAME_VOICE;
 177                 pvt->f.subclass = 0;
 178                 pvt->f.samples = 160;
 179                 pvt->f.data.ptr = NULL;
 180                 pvt->f.offset = 0;
 181                 pvt->f.datalen = 0;
 182                 pvt->f.mallocd = 0;
 183                 ast_set_flag(&pvt->f, AST_FRFLAG_FROM_TRANSLATOR);
 184                 pvt->samples = 0;
 185
 186                 return &pvt->f;
 187
 188         } else if (1 == dahdip->fake) {
 189
 190                 return NULL;
 191
 192         }
 193         /* Shouldn't get here... */
 194         return NULL;
 195 }
 196
 197 static void dahdi_destroy(struct ast_trans_pvt *pvt)
 198 {
 199         struct pvt *dahdip = pvt->pvt;
 200
 201         switch (dahdip->fmts.dstfmt) {
 202         case AST_FORMAT_G729A:
 203         case AST_FORMAT_G723_1:
 204                 ast_atomic_fetchadd_int(&channels.encoders, -1);
 205                 break;
 206         default:
 207                 ast_atomic_fetchadd_int(&channels.decoders, -1);
 208                 break;
 209         }
 210
 211         close(dahdip->fd);
 212 }
 213
 214 static int dahdi_translate(struct ast_trans_pvt *pvt, int dest, int source)
 215 {
 216         /* Request translation through zap if possible */
 217         int fd;
 218         struct pvt *dahdip = pvt->pvt;
 219         int flags;
 220
 221         if ((fd = open("/dev/dahdi/transcode", O_RDWR)) < 0) {
 222                 ast_log(LOG_ERROR, "Failed to open /dev/dahdi/transcode: %s\n", strerror(errno));
 223                 return -1;
 224         }
 225
 226         dahdip->fmts.srcfmt = (1 << source);
 227         dahdip->fmts.dstfmt = (1 << dest);
 228
 229         ast_log(LOG_VERBOSE, "Opening transcoder channel from %d to %d.\n", source, dest);
 230
 231         if (ioctl(fd, DAHDI_TC_ALLOCATE, &dahdip->fmts)) {
 232                 ast_log(LOG_ERROR, "Unable to attach to transcoder: %s\n", strerror(errno));
 233                 close(fd);
 234
 235                 return -1;
 236         }
 237
 238         flags = fcntl(fd, F_GETFL);
 239         if (flags > - 1) {
 240                 if (fcntl(fd, F_SETFL, flags | O_NONBLOCK))
 241                         ast_log(LOG_WARNING, "Could not set non-block mode!\n");
 242         }
 243
 244         dahdip->fd = fd;
 245
 246         switch (dahdip->fmts.dstfmt) {
 247         case AST_FORMAT_G729A:
 248                 dahdip->samples = 160;
 249                 break;
 250         case AST_FORMAT_G723_1:
 251                 dahdip->samples = 240;
 252                 ast_atomic_fetchadd_int(&channels.encoders, +1);
 253                 break;
 254         default:
 255                 dahdip->samples = 160;
 256                 ast_atomic_fetchadd_int(&channels.decoders, +1);
 257                 break;
 258         }
 259
 260         return 0;
 261 }
 262
 263 static int dahdi_new(struct ast_trans_pvt *pvt)
 264 {
 265         return dahdi_translate(pvt, pvt->t->dstfmt, pvt->t->srcfmt);
 266 }
 267
 268 static struct ast_frame *fakesrc_sample(void)
 269 {
 270         /* Don't bother really trying to test hardware ones. */
 271         static struct ast_frame f = {
 272                 .frametype = AST_FRAME_VOICE,
 273                 .samples = 160,
 274                 .src = __PRETTY_FUNCTION__
 275         };
 276
 277         return &f;
 278 }
 279
 280 static int register_translator(int dst, int src)
 281 {
 282         struct translator *dahdi;
 283         int res;
 284
 285         if (!(dahdi = ast_calloc(1, sizeof(*dahdi))))
 286                 return -1;
 287
 288         snprintf((char *) (dahdi->t.name), sizeof(dahdi->t.name), "dahdi%sto%s",
 289                  ast_getformatname((1 << src)), ast_getformatname((1 << dst)));
 290         dahdi->t.srcfmt = (1 << src);
 291         dahdi->t.dstfmt = (1 << dst);
 292         dahdi->t.newpvt = dahdi_new;
 293         dahdi->t.framein = dahdi_framein;
 294         dahdi->t.frameout = dahdi_frameout;
 295         dahdi->t.destroy = dahdi_destroy;
 296         dahdi->t.sample = fakesrc_sample;
 297         dahdi->t.useplc = global_useplc;
 298         dahdi->t.buf_size = BUFFER_SAMPLES * 2;
 299         dahdi->t.desc_size = sizeof(struct pvt);
 300         if ((res = ast_register_translator(&dahdi->t))) {
 301                 ast_free(dahdi);
 302                 return -1;
 303         }
 304
 305         AST_LIST_LOCK(&translators);
 306         AST_LIST_INSERT_HEAD(&translators, dahdi, entry);
 307         AST_LIST_UNLOCK(&translators);
 308
 309         global_format_map.map[dst][src] = 1;
 310
 311         return res;
 312 }
 313
 314 static void drop_translator(int dst, int src)
 315 {
 316         struct translator *cur;
 317
 318         AST_LIST_LOCK(&translators);
 319         AST_LIST_TRAVERSE_SAFE_BEGIN(&translators, cur, entry) {
 320                 if (cur->t.srcfmt != src)
 321                         continue;
 322
 323                 if (cur->t.dstfmt != dst)
 324                         continue;
 325
 326                 AST_LIST_REMOVE_CURRENT(entry);
 327                 ast_unregister_translator(&cur->t);
 328                 ast_free(cur);
 329                 global_format_map.map[dst][src] = 0;
 330                 break;
 331         }
 332         AST_LIST_TRAVERSE_SAFE_END;
 333         AST_LIST_UNLOCK(&translators);
 334 }
 335
 336 static void unregister_translators(void)
 337 {
 338         struct translator *current;
 339
 340         AST_LIST_LOCK(&translators);
 341         while ((current = AST_LIST_REMOVE_HEAD(&translators, entry))) {
 342                 ast_unregister_translator(&current->t);
 343                 ast_free(current);
 344         }
 345         AST_LIST_UNLOCK(&translators);
 346 }
 347
 348 static int parse_config(int reload)
 349 {
 350         struct ast_variable *var;
 351         struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
 352         struct ast_config *cfg = ast_config_load("codecs.conf", config_flags);
 353
 354         if (cfg == NULL)
 355                 return 0;
 356         if (cfg == CONFIG_STATUS_FILEUNCHANGED)
 357                 return 0;
 358
 359         for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
 360                if (!strcasecmp(var->name, "genericplc")) {
 361                        global_useplc = ast_true(var->value);
 362                            ast_verb(3, "codec_dahdi: %susing generic PLC\n",
 363                                            global_useplc ? "" : "not ");
 364                }
 365         }
 366         ast_config_destroy(cfg);
 367         return 0;
 368 }
 369
 370 static void build_translators(struct format_map *map, unsigned int dstfmts, unsigned int srcfmts)
 371 {
 372         unsigned int src, dst;
 373
 374         for (src = 0; src < 32; src++) {
 375                 for (dst = 0; dst < 32; dst++) {
 376                         if (!(srcfmts & (1 << src)))
 377                                 continue;
 378
 379                         if (!(dstfmts & (1 << dst)))
 380                                 continue;
 381
 382                         if (global_format_map.map[dst][src])
 383                                 continue;
 384
 385                         if (!register_translator(dst, src))
 386                                 map->map[dst][src] = 1;
 387                 }
 388         }
 389 }
 390
 391 static int find_transcoders(void)
 392 {
 393         struct dahdi_transcoder_info info = { 0, };
 394         struct format_map map = { { { 0 } } };
 395         int fd, res;
 396         unsigned int x, y;
 397
 398         if ((fd = open("/dev/dahdi/transcode", O_RDWR)) < 0) {
 399                 ast_log(LOG_ERROR, "Failed to open /dev/dahdi/transcode: %s\n", strerror(errno));
 400                 return 0;
 401         }
 402
 403         for (info.tcnum = 0; !(res = ioctl(fd, DAHDI_TC_GETINFO, &info)); info.tcnum++) {
 404                 if (option_verbose > 1)
 405                         ast_verbose(VERBOSE_PREFIX_2 "Found transcoder '%s'.\n", info.name);
 406                 build_translators(&map, info.dstfmts, info.srcfmts);
 407                 ast_atomic_fetchadd_int(&channels.total, info.numchannels / 2);
 408         }
 409
 410         close(fd);
 411
 412         if (!info.tcnum && (option_verbose > 1))
 413                 ast_verbose(VERBOSE_PREFIX_2 "No hardware transcoders found.\n");
 414
 415         for (x = 0; x < 32; x++) {
 416                 for (y = 0; y < 32; y++) {
 417                         if (!map.map[x][y] && global_format_map.map[x][y])
 418                                 drop_translator(x, y);
 419                 }
 420         }
 421
 422         return 0;
 423 }
 424
 425 static int reload(void)
 426 {
 427         struct translator *cur;
 428
 429         if (parse_config(1))
 430                 return AST_MODULE_LOAD_DECLINE;
 431
 432         AST_LIST_LOCK(&translators);
 433         AST_LIST_TRAVERSE(&translators, cur, entry)
 434                 cur->t.useplc = global_useplc;
 435         AST_LIST_UNLOCK(&translators);
 436
 437         return AST_MODULE_LOAD_SUCCESS;
 438 }
 439
 440 static int unload_module(void)
 441 {
 442         ast_cli_unregister_multiple(cli, ARRAY_LEN(cli));
 443         unregister_translators();
 444
 445         return 0;
 446 }
 447
 448 static int load_module(void)
 449 {
 450         if (parse_config(0))
 451                 return AST_MODULE_LOAD_DECLINE;
 452         find_transcoders();
 453         ast_cli_register_multiple(cli, ARRAY_LEN(cli));
 454         return AST_MODULE_LOAD_SUCCESS;
 455 }
 456
 457 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Generic DAHDI Transcoder Codec Translator",
 458                 .load = load_module,
 459                 .unload = unload_module,
 460                 .reload = reload,
 461                 );