Bridge Interaction Channel. More...

#include "asterisk.h"
#include <fcntl.h>
#include <sys/signal.h>
#include "asterisk/lock.h"
#include "asterisk/channel.h"
#include "asterisk/config.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/sched.h"
#include "asterisk/io.h"
#include "asterisk/rtp.h"
#include "asterisk/acl.h"
#include "asterisk/callerid.h"
#include "asterisk/file.h"
#include "asterisk/cli.h"
#include "asterisk/app.h"
#include "asterisk/bridging.h"

Include dependency graph for chan_bridge.c:

Go to the source code of this file.

Data Structures
struct	bridge_pvt
Functions
static void	__reg_module (void)
static void	__unreg_module (void)
static struct ast_channel *	bridge_bridgedchannel (struct ast_channel chan, struct ast_channel bridge)
	Called when the user of this channel wants to get the actual channel in the bridge.
static int	bridge_call (struct ast_channel ast, char dest, int timeout)
	Called when the channel should actually be dialed.
static int	bridge_hangup (struct ast_channel *ast)
	Called when a channel should be hung up.
static void	bridge_queue_hangup (struct bridge_pvt p, struct ast_channel us)
	Helper function to not deadlock when queueing the hangup frame.
static struct ast_frame *	bridge_read (struct ast_channel *ast)
	Called when a frame should be read from the channel.
static struct ast_channel *	bridge_request (const char type, int format, void data, int *cause)
	Called when we want to place a call somewhere, but not actually call it... yet.
static int	bridge_write (struct ast_channel ast, struct ast_frame f)
	Called when a frame should be written out to a channel.
static int	load_module (void)
	Load module into PBX, register channel.
static int	unload_module (void)
	Unload the bridge interaction channel from Asterisk.
Variables
static struct ast_module_info __MODULE_INFO_SECTION	__mod_info = { __MODULE_INFO_GLOBALS .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "Bridge Interaction Channel" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, }
static struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_channel_tech	bridge_tech

Detailed Description

Bridge Interaction Channel.

Author:: Joshua Colp <jcolp@digium.com>

Definition in file chan_bridge.c.

Function Documentation

static void __reg_module ( void ) [static]

Definition at line 246 of file chan_bridge.c.

static void __unreg_module ( void ) [static]

Definition at line 246 of file chan_bridge.c.

static struct ast_channel * bridge_bridgedchannel	(	struct ast_channel *	chan,
		struct ast_channel *	bridge
	)		`[static, read]`

Called when the user of this channel wants to get the actual channel in the bridge.

Definition at line 78 of file chan_bridge.c.

References bridge_pvt::input, bridge_pvt::output, and ast_channel::tech_pvt.

{
   struct bridge_pvt *p = chan->tech_pvt;
   return (chan == p->input) ? p->output : bridge;
}

static int bridge_call	(	struct ast_channel *	ast,
		char *	dest,
		int	timeout
	)		`[static]`

Called when the channel should actually be dialed.

Definition at line 120 of file chan_bridge.c.

References ast_bridge_impart(), ast_channel::bridge, bridge_pvt::input, bridge_pvt::output, and ast_channel::tech_pvt.

{
   struct bridge_pvt *p = ast->tech_pvt;

   /* If no bridge has been provided on the input channel, bail out */
   if (!ast->bridge) {
      return -1;
   }

   /* Impart the output channel upon the given bridge of the input channel */
   ast_bridge_impart(p->input->bridge, p->output, NULL, NULL);

   return 0;
}

static int bridge_hangup ( struct ast_channel * ast ) [static]

Called when a channel should be hung up.

Definition at line 158 of file chan_bridge.c.

References ast_free, ast_mutex_destroy(), ast_mutex_lock(), ast_mutex_unlock(), bridge_queue_hangup(), bridge_pvt::input, bridge_pvt::lock, bridge_pvt::output, and ast_channel::tech_pvt.

{
   struct bridge_pvt *p = ast->tech_pvt;

   ast_mutex_lock(&p->lock);

   /* Figure out which channel this is... and set it to NULL as it has gone, but also queue up a hangup frame. */
   if (p->input == ast) {
      if (p->output) {
         bridge_queue_hangup(p, ast);
      }
      p->input = NULL;
   } else if (p->output == ast) {
      if (p->input) {
         bridge_queue_hangup(p, ast);
      }
      p->output = NULL;
   }

   /* Deal with the Asterisk portion of it */
   ast->tech_pvt = NULL;

   /* If both sides have been terminated free the structure and be done with things */
   if (!p->input && !p->output) {
      ast_mutex_unlock(&p->lock);
      ast_mutex_destroy(&p->lock);
      ast_free(p);
   } else {
      ast_mutex_unlock(&p->lock);
   }

   return 0;
}

static void bridge_queue_hangup	(	struct bridge_pvt *	p,
		struct ast_channel *	us
	)		`[static]`

Helper function to not deadlock when queueing the hangup frame.

Definition at line 136 of file chan_bridge.c.

References ast_channel_trylock, ast_channel_unlock, ast_mutex_trylock(), ast_mutex_unlock(), ast_queue_hangup(), CHANNEL_DEADLOCK_AVOIDANCE, bridge_pvt::input, bridge_pvt::lock, and bridge_pvt::output.

Referenced by bridge_hangup().

{
   struct ast_channel *other = (p->input == us ? p->output : p->input);

   while (other && ast_channel_trylock(other)) {
      ast_mutex_unlock(&p->lock);
      do {
         CHANNEL_DEADLOCK_AVOIDANCE(us);
      } while (ast_mutex_trylock(&p->lock));
      other = (p->input == us ? p->output : p->input);
   }

   /* We basically queue the frame up on the other channel if present */
   if (other) {
      ast_queue_hangup(other);
      ast_channel_unlock(other);
   }

   return;
}

static struct ast_frame * bridge_read ( struct ast_channel * ast ) [static, read]

Called when a frame should be read from the channel.

Definition at line 85 of file chan_bridge.c.

References ast_null_frame.

{
   return &ast_null_frame;
}

static struct ast_channel * bridge_request	(	const char *	type,
		int	format,
		void *	data,
		int *	cause
	)		`[static, read]`

Called when we want to place a call somewhere, but not actually call it... yet.

Definition at line 193 of file chan_bridge.c.

References ast_calloc, ast_channel_alloc(), ast_channel_free(), AST_FORMAT_SLINEAR, ast_free, ast_mutex_init(), AST_STATE_UP, bridge_tech, bridge_pvt::input, bridge_pvt::lock, ast_channel::nativeformats, bridge_pvt::output, ast_channel::rawreadformat, ast_channel::rawwriteformat, ast_channel::readformat, ast_channel::tech, ast_channel::tech_pvt, and ast_channel::writeformat.

{
   struct bridge_pvt *p = NULL;

   /* Try to allocate memory for our very minimal pvt structure */
   if (!(p = ast_calloc(1, sizeof(*p)))) {
      return NULL;
   }

   /* Try to grab two Asterisk channels to use as input and output channels */
   if (!(p->input = ast_channel_alloc(1, AST_STATE_UP, 0, 0, "", "", "", 0, "Bridge/%p-input", p))) {
      ast_free(p);
      return NULL;
   }
   if (!(p->output = ast_channel_alloc(1, AST_STATE_UP, 0, 0, "", "", "", 0, "Bridge/%p-output", p))) {
      ast_channel_free(p->input);
      ast_free(p);
      return NULL;
   }

   /* Setup the lock on the pvt structure, we will need that */
   ast_mutex_init(&p->lock);

   /* Setup parameters on both new channels */
   p->input->tech = p->output->tech = &bridge_tech;
   p->input->tech_pvt = p->output->tech_pvt = p;
   p->input->nativeformats = p->output->nativeformats = AST_FORMAT_SLINEAR;
   p->input->readformat = p->output->readformat = AST_FORMAT_SLINEAR;
   p->input->rawreadformat = p->output->rawreadformat = AST_FORMAT_SLINEAR;
   p->input->writeformat = p->output->writeformat = AST_FORMAT_SLINEAR;
   p->input->rawwriteformat = p->output->rawwriteformat = AST_FORMAT_SLINEAR;

   return p->input;
}

static int bridge_write	(	struct ast_channel *	ast,
		struct ast_frame *	f
	)		`[static]`

Called when a frame should be written out to a channel.

Definition at line 91 of file chan_bridge.c.

References ast_channel_trylock, ast_channel_unlock, ast_mutex_lock(), ast_mutex_trylock(), ast_mutex_unlock(), ast_queue_frame(), CHANNEL_DEADLOCK_AVOIDANCE, bridge_pvt::input, bridge_pvt::lock, bridge_pvt::output, and ast_channel::tech_pvt.

{
   struct bridge_pvt *p = ast->tech_pvt;
   struct ast_channel *other;

   ast_mutex_lock(&p->lock);

   other = (p->input == ast ? p->output : p->input);

   while (other && ast_channel_trylock(other)) {
      ast_mutex_unlock(&p->lock);
      do {
         CHANNEL_DEADLOCK_AVOIDANCE(ast);
      } while (ast_mutex_trylock(&p->lock));
      other = (p->input == ast ? p->output : p->input);
   }

   /* We basically queue the frame up on the other channel if present */
   if (other) {
      ast_queue_frame(other, f);
      ast_channel_unlock(other);
   }

   ast_mutex_unlock(&p->lock);

   return 0;
}

static int load_module ( void ) [static]

Load module into PBX, register channel.

Definition at line 229 of file chan_bridge.c.

References ast_channel_register(), ast_log(), AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, and LOG_ERROR.

{
   /* Make sure we can register our channel type */
   if (ast_channel_register(&bridge_tech)) {
      ast_log(LOG_ERROR, "Unable to register channel class 'Bridge'\n");
      return AST_MODULE_LOAD_FAILURE;
   }
   return AST_MODULE_LOAD_SUCCESS;
}

static int unload_module ( void ) [static]

Unload the bridge interaction channel from Asterisk.

Definition at line 240 of file chan_bridge.c.

References ast_channel_unregister().

{
   ast_channel_unregister(&bridge_tech);
   return 0;
}

Variable Documentation

struct ast_module_info __MODULE_INFO_SECTION __mod_info = { __MODULE_INFO_GLOBALS .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "Bridge Interaction Channel" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, } [static]

Definition at line 246 of file chan_bridge.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 246 of file chan_bridge.c.

struct ast_channel_tech bridge_tech [static]

Definition at line 57 of file chan_bridge.c.

Referenced by bridge_request().

Asterisk developer's documentation

chan_bridge.c File Reference
Module: Asterisk Channel Drivers

Data Structures

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation

Asterisk developer's documentation

chan_bridge.c File ReferenceModule: Asterisk Channel Drivers

Data Structures

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation

chan_bridge.c File Reference
Module: Asterisk Channel Drivers