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