channels/chan_nbs.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2006, 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 Network broadcast sound support channel driver
  22  *
  23  * \author Mark Spencer <markster@digium.com>
  24  *
  25  * \ingroup channel_drivers
  26  */
  27
  28 /*** MODULEINFO
  29         <depend>nbs</depend>
  30  ***/
  31
  32 #include "asterisk.h"
  33
  34 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  35
  36 #include <stdio.h>
  37 #include <string.h>
  38 #include <sys/socket.h>
  39 #include <sys/time.h>
  40 #include <errno.h>
  41 #include <unistd.h>
  42 #include <stdlib.h>
  43 #include <arpa/inet.h>
  44 #include <fcntl.h>
  45 #include <sys/ioctl.h>
  46 #include <nbs.h>
  47
  48 #include "asterisk/lock.h"
  49 #include "asterisk/channel.h"
  50 #include "asterisk/config.h"
  51 #include "asterisk/logger.h"
  52 #include "asterisk/module.h"
  53 #include "asterisk/pbx.h"
  54 #include "asterisk/options.h"
  55 #include "asterisk/utils.h"
  56
  57 static const char tdesc[] = "Network Broadcast Sound Driver";
  58
  59 /* Only linear is allowed */
  60 static int prefformat = AST_FORMAT_SLINEAR;
  61
  62 static char context[AST_MAX_EXTENSION] = "default";
  63 static char type[] = "NBS";
  64
  65 /* NBS creates private structures on demand */
  66
  67 struct nbs_pvt {
  68         NBS *nbs;
  69         struct ast_channel *owner;              /* Channel we belong to, possibly NULL */
  70         char app[16];                                   /* Our app */
  71         char stream[80];                                /* Our stream */
  72         struct ast_frame fr;                    /* "null" frame */
  73         struct ast_module_user *u;              /*! for holding a reference to this module */
  74 };
  75
  76 static struct ast_channel *nbs_request(const char *type, int format, void *data, int *cause);
  77 static int nbs_call(struct ast_channel *ast, char *dest, int timeout);
  78 static int nbs_hangup(struct ast_channel *ast);
  79 static struct ast_frame *nbs_xread(struct ast_channel *ast);
  80 static int nbs_xwrite(struct ast_channel *ast, struct ast_frame *frame);
  81
  82 static const struct ast_channel_tech nbs_tech = {
  83         .type = type,
  84         .description = tdesc,
  85         .capabilities = AST_FORMAT_SLINEAR,
  86         .requester = nbs_request,
  87         .call = nbs_call,
  88         .hangup = nbs_hangup,
  89         .read = nbs_xread,
  90         .write = nbs_xwrite,
  91 };
  92
  93 static int nbs_call(struct ast_channel *ast, char *dest, int timeout)
  94 {
  95         struct nbs_pvt *p;
  96
  97         p = ast->tech_pvt;
  98
  99         if ((ast->_state != AST_STATE_DOWN) && (ast->_state != AST_STATE_RESERVED)) {
 100                 ast_log(LOG_WARNING, "nbs_call called on %s, neither down nor reserved\n", ast->name);
 101                 return -1;
 102         }
 103         /* When we call, it just works, really, there's no destination...  Just
 104            ring the phone and wait for someone to answer */
 105         if (option_debug)
 106                 ast_log(LOG_DEBUG, "Calling %s on %s\n", dest, ast->name);
 107
 108         /* If we can't connect, return congestion */
 109         if (nbs_connect(p->nbs)) {
 110                 ast_log(LOG_WARNING, "NBS Connection failed on %s\n", ast->name);
 111                 ast_queue_control(ast, AST_CONTROL_CONGESTION);
 112         } else {
 113                 ast_setstate(ast, AST_STATE_RINGING);
 114                 ast_queue_control(ast, AST_CONTROL_ANSWER);
 115         }
 116
 117         return 0;
 118 }
 119
 120 static void nbs_destroy(struct nbs_pvt *p)
 121 {
 122         if (p->nbs)
 123                 nbs_delstream(p->nbs);
 124         ast_module_user_remove(p->u);
 125         free(p);
 126 }
 127
 128 static struct nbs_pvt *nbs_alloc(void *data)
 129 {
 130         struct nbs_pvt *p;
 131         int flags = 0;
 132         char stream[256];
 133         char *opts;
 134
 135         ast_copy_string(stream, data, sizeof(stream));
 136         if ((opts = strchr(stream, ':'))) {
 137                 *opts = '\0';
 138                 opts++;
 139         } else
 140                 opts = "";
 141         p = malloc(sizeof(struct nbs_pvt));
 142         if (p) {
 143                 memset(p, 0, sizeof(struct nbs_pvt));
 144                 if (!ast_strlen_zero(opts)) {
 145                         if (strchr(opts, 'm'))
 146                                 flags |= NBS_FLAG_MUTE;
 147                         if (strchr(opts, 'o'))
 148                                 flags |= NBS_FLAG_OVERSPEAK;
 149                         if (strchr(opts, 'e'))
 150                                 flags |= NBS_FLAG_EMERGENCY;
 151                         if (strchr(opts, 'O'))
 152                                 flags |= NBS_FLAG_OVERRIDE;
 153                 } else
 154                         flags = NBS_FLAG_OVERSPEAK;
 155
 156                 ast_copy_string(p->stream, stream, sizeof(p->stream));
 157                 p->nbs = nbs_newstream("asterisk", stream, flags);
 158                 if (!p->nbs) {
 159                         ast_log(LOG_WARNING, "Unable to allocate new NBS stream '%s' with flags %d\n", stream, flags);
 160                         free(p);
 161                         p = NULL;
 162                 } else {
 163                         /* Set for 8000 hz mono, 640 samples */
 164                         nbs_setbitrate(p->nbs, 8000);
 165                         nbs_setchannels(p->nbs, 1);
 166                         nbs_setblocksize(p->nbs, 640);
 167                         nbs_setblocking(p->nbs, 0);
 168                 }
 169         }
 170         return p;
 171 }
 172
 173 static int nbs_hangup(struct ast_channel *ast)
 174 {
 175         struct nbs_pvt *p;
 176         p = ast->tech_pvt;
 177         if (option_debug)
 178                 ast_log(LOG_DEBUG, "nbs_hangup(%s)\n", ast->name);
 179         if (!ast->tech_pvt) {
 180                 ast_log(LOG_WARNING, "Asked to hangup channel not connected\n");
 181                 return 0;
 182         }
 183         nbs_destroy(p);
 184         ast->tech_pvt = NULL;
 185         ast_setstate(ast, AST_STATE_DOWN);
 186         return 0;
 187 }
 188
 189 static struct ast_frame  *nbs_xread(struct ast_channel *ast)
 190 {
 191         struct nbs_pvt *p = ast->tech_pvt;
 192
 193
 194         /* Some nice norms */
 195         p->fr.datalen = 0;
 196         p->fr.samples = 0;
 197         p->fr.data =  NULL;
 198         p->fr.src = type;
 199         p->fr.offset = 0;
 200         p->fr.mallocd=0;
 201         p->fr.delivery.tv_sec = 0;
 202         p->fr.delivery.tv_usec = 0;
 203
 204         ast_log(LOG_DEBUG, "Returning null frame on %s\n", ast->name);
 205
 206         return &p->fr;
 207 }
 208
 209 static int nbs_xwrite(struct ast_channel *ast, struct ast_frame *frame)
 210 {
 211         struct nbs_pvt *p = ast->tech_pvt;
 212         /* Write a frame of (presumably voice) data */
 213         if (frame->frametype != AST_FRAME_VOICE) {
 214                 if (frame->frametype != AST_FRAME_IMAGE)
 215                         ast_log(LOG_WARNING, "Don't know what to do with  frame type '%d'\n", frame->frametype);
 216                 return 0;
 217         }
 218         if (!(frame->subclass &
 219                 (AST_FORMAT_SLINEAR))) {
 220                 ast_log(LOG_WARNING, "Cannot handle frames in %d format\n", frame->subclass);
 221                 return 0;
 222         }
 223         if (ast->_state != AST_STATE_UP) {
 224                 /* Don't try tos end audio on-hook */
 225                 return 0;
 226         }
 227         if (nbs_write(p->nbs, frame->data, frame->datalen / 2) < 0)
 228                 return -1;
 229         return 0;
 230 }
 231
 232 static struct ast_channel *nbs_new(struct nbs_pvt *i, int state)
 233 {
 234         struct ast_channel *tmp;
 235         tmp = ast_channel_alloc(1, state, 0, 0, "", "s", context, 0, "NBS/%s", i->stream);
 236         if (tmp) {
 237                 tmp->tech = &nbs_tech;
 238                 tmp->fds[0] = nbs_fd(i->nbs);
 239                 tmp->nativeformats = prefformat;
 240                 tmp->rawreadformat = prefformat;
 241                 tmp->rawwriteformat = prefformat;
 242                 tmp->writeformat = prefformat;
 243                 tmp->readformat = prefformat;
 244                 if (state == AST_STATE_RING)
 245                         tmp->rings = 1;
 246                 tmp->tech_pvt = i;
 247                 ast_copy_string(tmp->context, context, sizeof(tmp->context));
 248                 ast_copy_string(tmp->exten, "s",  sizeof(tmp->exten));
 249                 ast_string_field_set(tmp, language, "");
 250                 i->owner = tmp;
 251                 i->u = ast_module_user_add(tmp);
 252                 if (state != AST_STATE_DOWN) {
 253                         if (ast_pbx_start(tmp)) {
 254                                 ast_log(LOG_WARNING, "Unable to start PBX on %s\n", tmp->name);
 255                                 ast_hangup(tmp);
 256                         }
 257                 }
 258         } else
 259                 ast_log(LOG_WARNING, "Unable to allocate channel structure\n");
 260         return tmp;
 261 }
 262
 263
 264 static struct ast_channel *nbs_request(const char *type, int format, void *data, int *cause)
 265 {
 266         int oldformat;
 267         struct nbs_pvt *p;
 268         struct ast_channel *tmp = NULL;
 269
 270         oldformat = format;
 271         format &= (AST_FORMAT_SLINEAR);
 272         if (!format) {
 273                 ast_log(LOG_NOTICE, "Asked to get a channel of unsupported format '%d'\n", oldformat);
 274                 return NULL;
 275         }
 276         p = nbs_alloc(data);
 277         if (p) {
 278                 tmp = nbs_new(p, AST_STATE_DOWN);
 279                 if (!tmp)
 280                         nbs_destroy(p);
 281         }
 282         return tmp;
 283 }
 284
 285 static int unload_module(void)
 286 {
 287         /* First, take us out of the channel loop */
 288         ast_channel_unregister(&nbs_tech);
 289         return 0;
 290 }
 291
 292 static int load_module(void)
 293 {
 294         /* Make sure we can register our channel type */
 295         if (ast_channel_register(&nbs_tech)) {
 296                 ast_log(LOG_ERROR, "Unable to register channel class %s\n", type);
 297                 return -1;
 298         }
 299         return 0;
 300 }
 301
 302 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Network Broadcast Sound Support");