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 struct ast_format prefformat;
  54
  55 static char context[AST_MAX_EXTENSION] = "default";
  56 static const 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, struct ast_format_cap *cap, const struct ast_channel *requestor, 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 struct ast_channel_tech nbs_tech = {
  76         .type = type,
  77         .description = tdesc,
  78         .requester = nbs_request,
  79         .call = nbs_call,
  80         .hangup = nbs_hangup,
  81         .read = nbs_xread,
  82         .write = nbs_xwrite,
  83 };
  84
  85 static int nbs_call(struct ast_channel *ast, char *dest, int timeout)
  86 {
  87         struct nbs_pvt *p;
  88
  89         p = ast->tech_pvt;
  90
  91         if ((ast->_state != AST_STATE_DOWN) && (ast->_state != AST_STATE_RESERVED)) {
  92                 ast_log(LOG_WARNING, "nbs_call called on %s, neither down nor reserved\n", ast->name);
  93                 return -1;
  94         }
  95         /* When we call, it just works, really, there's no destination...  Just
  96            ring the phone and wait for someone to answer */
  97         ast_debug(1, "Calling %s on %s\n", dest, ast->name);
  98
  99         /* If we can't connect, return congestion */
 100         if (nbs_connect(p->nbs)) {
 101                 ast_log(LOG_WARNING, "NBS Connection failed on %s\n", ast->name);
 102                 ast_queue_control(ast, AST_CONTROL_CONGESTION);
 103         } else {
 104                 ast_setstate(ast, AST_STATE_RINGING);
 105                 ast_queue_control(ast, AST_CONTROL_ANSWER);
 106         }
 107
 108         return 0;
 109 }
 110
 111 static void nbs_destroy(struct nbs_pvt *p)
 112 {
 113         if (p->nbs)
 114                 nbs_delstream(p->nbs);
 115         ast_module_user_remove(p->u);
 116         ast_free(p);
 117 }
 118
 119 static struct nbs_pvt *nbs_alloc(void *data)
 120 {
 121         struct nbs_pvt *p;
 122         int flags = 0;
 123         char stream[256];
 124         char *opts;
 125
 126         ast_copy_string(stream, data, sizeof(stream));
 127         if ((opts = strchr(stream, ':'))) {
 128                 *opts = '\0';
 129                 opts++;
 130         } else
 131                 opts = "";
 132         p = ast_calloc(1, sizeof(*p));
 133         if (p) {
 134                 if (!ast_strlen_zero(opts)) {
 135                         if (strchr(opts, 'm'))
 136                                 flags |= NBS_FLAG_MUTE;
 137                         if (strchr(opts, 'o'))
 138                                 flags |= NBS_FLAG_OVERSPEAK;
 139                         if (strchr(opts, 'e'))
 140                                 flags |= NBS_FLAG_EMERGENCY;
 141                         if (strchr(opts, 'O'))
 142                                 flags |= NBS_FLAG_OVERRIDE;
 143                 } else
 144                         flags = NBS_FLAG_OVERSPEAK;
 145
 146                 ast_copy_string(p->stream, stream, sizeof(p->stream));
 147                 p->nbs = nbs_newstream("asterisk", stream, flags);
 148                 if (!p->nbs) {
 149                         ast_log(LOG_WARNING, "Unable to allocate new NBS stream '%s' with flags %d\n", stream, flags);
 150                         ast_free(p);
 151                         p = NULL;
 152                 } else {
 153                         /* Set for 8000 hz mono, 640 samples */
 154                         nbs_setbitrate(p->nbs, 8000);
 155                         nbs_setchannels(p->nbs, 1);
 156                         nbs_setblocksize(p->nbs, 640);
 157                         nbs_setblocking(p->nbs, 0);
 158                 }
 159         }
 160         return p;
 161 }
 162
 163 static int nbs_hangup(struct ast_channel *ast)
 164 {
 165         struct nbs_pvt *p;
 166         p = ast->tech_pvt;
 167         ast_debug(1, "nbs_hangup(%s)\n", ast->name);
 168         if (!ast->tech_pvt) {
 169                 ast_log(LOG_WARNING, "Asked to hangup channel not connected\n");
 170                 return 0;
 171         }
 172         nbs_destroy(p);
 173         ast->tech_pvt = NULL;
 174         ast_setstate(ast, AST_STATE_DOWN);
 175         return 0;
 176 }
 177
 178 static struct ast_frame  *nbs_xread(struct ast_channel *ast)
 179 {
 180         struct nbs_pvt *p = ast->tech_pvt;
 181
 182
 183         /* Some nice norms */
 184         p->fr.datalen = 0;
 185         p->fr.samples = 0;
 186         p->fr.data.ptr =  NULL;
 187         p->fr.src = type;
 188         p->fr.offset = 0;
 189         p->fr.mallocd=0;
 190         p->fr.delivery.tv_sec = 0;
 191         p->fr.delivery.tv_usec = 0;
 192
 193         ast_debug(1, "Returning null frame on %s\n", ast->name);
 194
 195         return &p->fr;
 196 }
 197
 198 static int nbs_xwrite(struct ast_channel *ast, struct ast_frame *frame)
 199 {
 200         struct nbs_pvt *p = ast->tech_pvt;
 201         /* Write a frame of (presumably voice) data */
 202         if (frame->frametype != AST_FRAME_VOICE) {
 203                 if (frame->frametype != AST_FRAME_IMAGE)
 204                         ast_log(LOG_WARNING, "Don't know what to do with  frame type '%d'\n", frame->frametype);
 205                 return 0;
 206         }
 207         if (frame->subclass.format.id != (AST_FORMAT_SLINEAR)) {
 208                 ast_log(LOG_WARNING, "Cannot handle frames in %s format\n", ast_getformatname(&frame->subclass.format));
 209                 return 0;
 210         }
 211         if (ast->_state != AST_STATE_UP) {
 212                 /* Don't try tos end audio on-hook */
 213                 return 0;
 214         }
 215         if (nbs_write(p->nbs, frame->data.ptr, frame->datalen / 2) < 0)
 216                 return -1;
 217         return 0;
 218 }
 219
 220 static struct ast_channel *nbs_new(struct nbs_pvt *i, int state, const char *linkedid)
 221 {
 222         struct ast_channel *tmp;
 223         tmp = ast_channel_alloc(1, state, 0, 0, "", "s", context, linkedid, 0, "NBS/%s", i->stream);
 224         if (tmp) {
 225                 tmp->tech = &nbs_tech;
 226                 ast_channel_set_fd(tmp, 0, nbs_fd(i->nbs));
 227
 228                 ast_format_cap_add(tmp->nativeformats, &prefformat);
 229                 ast_format_copy(&tmp->rawreadformat, &prefformat);
 230                 ast_format_copy(&tmp->rawwriteformat, &prefformat);
 231                 ast_format_copy(&tmp->writeformat, &prefformat);
 232                 ast_format_copy(&tmp->readformat, &prefformat);
 233                 if (state == AST_STATE_RING)
 234                         tmp->rings = 1;
 235                 tmp->tech_pvt = i;
 236                 ast_copy_string(tmp->context, context, sizeof(tmp->context));
 237                 ast_copy_string(tmp->exten, "s",  sizeof(tmp->exten));
 238                 ast_string_field_set(tmp, language, "");
 239                 i->owner = tmp;
 240                 i->u = ast_module_user_add(tmp);
 241                 if (state != AST_STATE_DOWN) {
 242                         if (ast_pbx_start(tmp)) {
 243                                 ast_log(LOG_WARNING, "Unable to start PBX on %s\n", tmp->name);
 244                                 ast_hangup(tmp);
 245                         }
 246                 }
 247         } else
 248                 ast_log(LOG_WARNING, "Unable to allocate channel structure\n");
 249         return tmp;
 250 }
 251
 252
 253 static struct ast_channel *nbs_request(const char *type, struct ast_format_cap *cap, const struct ast_channel *requestor, void *data, int *cause)
 254 {
 255         struct nbs_pvt *p;
 256         struct ast_channel *tmp = NULL;
 257
 258         if (!(ast_format_cap_iscompatible(cap, &prefformat))) {
 259                 char tmp[256];
 260                 ast_log(LOG_NOTICE, "Asked to get a channel of unsupported format '%s'\n", ast_getformatname_multiple(tmp, sizeof(tmp), cap));
 261                 return NULL;
 262         }
 263         p = nbs_alloc(data);
 264         if (p) {
 265                 tmp = nbs_new(p, AST_STATE_DOWN, requestor ? requestor->linkedid : NULL);
 266                 if (!tmp)
 267                         nbs_destroy(p);
 268         }
 269         return tmp;
 270 }
 271
 272 static int unload_module(void)
 273 {
 274         /* First, take us out of the channel loop */
 275         ast_channel_unregister(&nbs_tech);
 276         nbs_tech.capabilities = ast_format_cap_destroy(nbs_tech.capabilities);
 277         return 0;
 278 }
 279
 280 static int load_module(void)
 281 {
 282         ast_format_set(&prefformat, AST_FORMAT_SLINEAR, 0);
 283         if (!(nbs_tech.capabilities = ast_format_cap_alloc())) {
 284                 return AST_MODULE_LOAD_FAILURE;
 285         }
 286         ast_format_cap_add(nbs_tech.capabilities, &prefformat);
 287         /* Make sure we can register our channel type */
 288         if (ast_channel_register(&nbs_tech)) {
 289                 ast_log(LOG_ERROR, "Unable to register channel class %s\n", type);
 290                 return AST_MODULE_LOAD_DECLINE;
 291         }
 292         return AST_MODULE_LOAD_SUCCESS;
 293 }
 294
 295 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Network Broadcast Sound Support");