Thu Apr 28 2011 17:15:36

Asterisk developer's documentation


bridge_builtin_features.c File Reference

Built in bridging features. More...

#include "asterisk.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/bridging.h"
#include "asterisk/bridging_technology.h"
#include "asterisk/frame.h"
#include "asterisk/file.h"
#include "asterisk/app.h"
#include "asterisk/astobj2.h"
Include dependency graph for bridge_builtin_features.c:

Go to the source code of this file.

Functions

static void __reg_module (void)
static void __unreg_module (void)
static int attended_abort_transfer (struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt)
 Attended transfer abort feature.
static int attended_threeway_transfer (struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt)
 Attended transfer feature to turn it into a threeway call.
static struct ast_channeldial_transfer (const struct ast_channel *caller, const char *exten, const char *context)
 Helper function that creates an outgoing channel and returns it immediately.
static int feature_attended_transfer (struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt)
 Internal built in feature for attended transfers.
static int feature_blind_transfer (struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt)
 Internal built in feature for blind transfers.
static int feature_hangup (struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt)
 Internal built in feature for hangup.
static int grab_transfer (struct ast_channel *chan, char *exten, size_t exten_len, const char *context)
 Helper function that presents dialtone and grabs extension.
static int load_module (void)
static int unload_module (void)

Variables

static struct ast_module_info
__MODULE_INFO_SECTION 
__mod_info = { __MODULE_INFO_GLOBALS .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "Built in bridging features" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, }
static struct ast_module_infoast_module_info = &__mod_info

Detailed Description

Built in bridging features.

Author:
Joshua Colp <jcolp@digium.com>

Definition in file bridge_builtin_features.c.


Function Documentation

static void __reg_module ( void  ) [static]

Definition at line 257 of file bridge_builtin_features.c.

static void __unreg_module ( void  ) [static]

Definition at line 257 of file bridge_builtin_features.c.

static int attended_abort_transfer ( struct ast_bridge bridge,
struct ast_bridge_channel bridge_channel,
void *  hook_pvt 
) [static]

Attended transfer abort feature.

Definition at line 131 of file bridge_builtin_features.c.

References ao2_lock(), ao2_unlock(), ast_bridge_change_state(), AST_BRIDGE_CHANNEL_STATE_END, AST_BRIDGE_CHANNEL_STATE_HANGUP, AST_LIST_FIRST, AST_LIST_LAST, and ast_bridge::channels.

Referenced by feature_attended_transfer().

{
   struct ast_bridge_channel *called_bridge_channel = NULL;

   /* It is possible (albeit unlikely) that the bridge channels list may change, so we have to ensure we do all of our magic while locked */
   ao2_lock(bridge);

   if (AST_LIST_FIRST(&bridge->channels) != bridge_channel) {
      called_bridge_channel = AST_LIST_FIRST(&bridge->channels);
   } else {
      called_bridge_channel = AST_LIST_LAST(&bridge->channels);
   }

   /* Now we basically eject the other channel from the bridge. This will cause their thread to hang them up, and our own code to consider the transfer failed. */
   if (called_bridge_channel) {
      ast_bridge_change_state(called_bridge_channel, AST_BRIDGE_CHANNEL_STATE_HANGUP);
   }

   ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_END);

   ao2_unlock(bridge);

   return 0;
}
static int attended_threeway_transfer ( struct ast_bridge bridge,
struct ast_bridge_channel bridge_channel,
void *  hook_pvt 
) [static]

Attended transfer feature to turn it into a threeway call.

Definition at line 123 of file bridge_builtin_features.c.

References ast_bridge_change_state(), and AST_BRIDGE_CHANNEL_STATE_DEPART.

Referenced by feature_attended_transfer().

{
   /* This is sort of abusing the depart state but in this instance it is only going to be handled in the below function so it is okay */
   ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_DEPART);
   return 0;
}
static struct ast_channel* dial_transfer ( const struct ast_channel caller,
const char *  exten,
const char *  context 
) [static, read]

Helper function that creates an outgoing channel and returns it immediately.

Definition at line 68 of file bridge_builtin_features.c.

References ast_call(), ast_channel_inherit_variables(), ast_hangup(), AST_MAX_CONTEXT, AST_MAX_EXTENSION, ast_request(), cause, chan, and ast_channel::nativeformats.

Referenced by feature_attended_transfer(), and feature_blind_transfer().

{
   char destination[AST_MAX_EXTENSION+AST_MAX_CONTEXT+1] = "";
   struct ast_channel *chan = NULL;
   int cause;

   /* Fill the variable with the extension and context we want to call */
   snprintf(destination, sizeof(destination), "%s@%s", exten, context);

   /* Now we request that chan_local prepare to call the destination */
   if (!(chan = ast_request("Local", caller->nativeformats, destination, &cause))) {
      return NULL;
   }

   /* Before we actually dial out let's inherit the appropriate dialplan variables */
   ast_channel_inherit_variables(caller, chan);

   /* Since the above worked fine now we actually call it and return the channel */
   if (ast_call(chan, destination, 0)) {
      ast_hangup(chan);
      return NULL;
   }

   return chan;
}
static int feature_attended_transfer ( struct ast_bridge bridge,
struct ast_bridge_channel bridge_channel,
void *  hook_pvt 
) [static]

Internal built in feature for attended transfers.

Definition at line 157 of file bridge_builtin_features.c.

References ast_bridge_features_attended_transfer::abort, AST_BRIDGE_BUILTIN_HANGUP, AST_BRIDGE_CAPABILITY_1TO1MIX, ast_bridge_change_state(), AST_BRIDGE_CHANNEL_STATE_DEPART, AST_BRIDGE_CHANNEL_STATE_HANGUP, AST_BRIDGE_CHANNEL_STATE_WAIT, ast_bridge_depart(), ast_bridge_destroy(), ast_bridge_features_cleanup(), ast_bridge_features_enable(), ast_bridge_features_hook(), ast_bridge_features_init(), ast_bridge_features_set_flag(), AST_BRIDGE_FLAG_DISSOLVE, ast_bridge_impart(), ast_bridge_join(), ast_bridge_new(), AST_DIGIT_ANY, ast_hangup(), AST_MAX_EXTENSION, ast_stream_and_wait(), ast_strlen_zero(), attended_abort_transfer(), attended_threeway_transfer(), ast_bridge_channel::chan, chan, ast_bridge_features_attended_transfer::complete, ast_channel::context, ast_bridge_features_attended_transfer::context, context, dial_transfer(), exten, grab_transfer(), and ast_bridge_features_attended_transfer::threeway.

Referenced by load_module().

{
   char exten[AST_MAX_EXTENSION] = "";
   struct ast_channel *chan = NULL;
   struct ast_bridge *attended_bridge = NULL;
   struct ast_bridge_features caller_features, called_features;
   enum ast_bridge_channel_state attended_bridge_result;
   struct ast_bridge_features_attended_transfer *attended_transfer = hook_pvt;
   const char *context = (attended_transfer && !ast_strlen_zero(attended_transfer->context) ? attended_transfer->context : bridge_channel->chan->context);

   /* Grab the extension to transfer to */
   if (!grab_transfer(bridge_channel->chan, exten, sizeof(exten), context)) {
      ast_stream_and_wait(bridge_channel->chan, "pbx-invalid", AST_DIGIT_ANY);
      ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
      return 0;
   }

   /* Get a channel that is the destination we wish to call */
   if (!(chan = dial_transfer(bridge_channel->chan, exten, context))) {
      ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY);
      ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
      return 0;
   }

   /* Create a bridge to use to talk to the person we are calling */
   if (!(attended_bridge = ast_bridge_new(AST_BRIDGE_CAPABILITY_1TO1MIX, 0))) {
      ast_hangup(chan);
      ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY);
      ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
      return 0;
   }

   /* Setup our called features structure so that if they hang up we immediately get thrown out of the bridge */
   ast_bridge_features_init(&called_features);
   ast_bridge_features_set_flag(&called_features, AST_BRIDGE_FLAG_DISSOLVE);

   /* This is how this is going down, we are imparting the channel we called above into this bridge first */
   ast_bridge_impart(attended_bridge, chan, NULL, &called_features);

   /* Before we join setup a features structure with the hangup option, just in case they want to use DTMF */
   ast_bridge_features_init(&caller_features);
   ast_bridge_features_enable(&caller_features, AST_BRIDGE_BUILTIN_HANGUP,
               (attended_transfer && !ast_strlen_zero(attended_transfer->complete) ? attended_transfer->complete : "*1"), NULL);
   ast_bridge_features_hook(&caller_features, (attended_transfer && !ast_strlen_zero(attended_transfer->threeway) ? attended_transfer->threeway : "*2"),
             attended_threeway_transfer, NULL);
   ast_bridge_features_hook(&caller_features, (attended_transfer && !ast_strlen_zero(attended_transfer->abort) ? attended_transfer->abort : "*3"),
             attended_abort_transfer, NULL);

   /* But for the caller we want to join the bridge in a blocking fashion so we don't spin around in this function doing nothing while waiting */
   attended_bridge_result = ast_bridge_join(attended_bridge, bridge_channel->chan, NULL, &caller_features);

   /* Since the above returned the caller features structure is of no more use */
   ast_bridge_features_cleanup(&caller_features);

   /* Drop the channel we are transferring to out of the above bridge since it has ended */
   if ((attended_bridge_result != AST_BRIDGE_CHANNEL_STATE_HANGUP) && !ast_bridge_depart(attended_bridge, chan)) {
      /* If the user wants to turn this into a threeway transfer then do so, otherwise they take our place */
      if (attended_bridge_result == AST_BRIDGE_CHANNEL_STATE_DEPART) {
         /* We want to impart them upon the bridge and just have us return to it as normal */
         ast_bridge_impart(bridge, chan, NULL, NULL);
      } else {
         ast_bridge_impart(bridge, chan, bridge_channel->chan, NULL);
      }
   } else {
      ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY);
      ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
   }

   /* Now that all channels are out of it we can destroy the bridge and the called features structure */
   ast_bridge_features_cleanup(&called_features);
   ast_bridge_destroy(attended_bridge);

   return 0;
}
static int feature_blind_transfer ( struct ast_bridge bridge,
struct ast_bridge_channel bridge_channel,
void *  hook_pvt 
) [static]

Internal built in feature for blind transfers.

Definition at line 95 of file bridge_builtin_features.c.

References ast_bridge_change_state(), AST_BRIDGE_CHANNEL_STATE_WAIT, ast_bridge_impart(), AST_DIGIT_ANY, AST_MAX_EXTENSION, ast_stream_and_wait(), ast_strlen_zero(), ast_bridge_channel::chan, chan, ast_channel::context, ast_bridge_features_blind_transfer::context, context, dial_transfer(), exten, and grab_transfer().

Referenced by load_module().

{
   char exten[AST_MAX_EXTENSION] = "";
   struct ast_channel *chan = NULL;
   struct ast_bridge_features_blind_transfer *blind_transfer = hook_pvt;
   const char *context = (blind_transfer && !ast_strlen_zero(blind_transfer->context) ? blind_transfer->context : bridge_channel->chan->context);

   /* Grab the extension to transfer to */
   if (!grab_transfer(bridge_channel->chan, exten, sizeof(exten), context)) {
      ast_stream_and_wait(bridge_channel->chan, "pbx-invalid", AST_DIGIT_ANY);
      ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
      return 0;
   }

   /* Get a channel that is the destination we wish to call */
   if (!(chan = dial_transfer(bridge_channel->chan, exten, context))) {
      ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY);
      ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
      return 0;
   }

   /* This is sort of the fun part. We impart the above channel onto the bridge, and have it take our place. */
   ast_bridge_impart(bridge, chan, bridge_channel->chan, NULL);

   return 0;
}
static int feature_hangup ( struct ast_bridge bridge,
struct ast_bridge_channel bridge_channel,
void *  hook_pvt 
) [static]

Internal built in feature for hangup.

Definition at line 233 of file bridge_builtin_features.c.

References ast_bridge_change_state(), and AST_BRIDGE_CHANNEL_STATE_END.

Referenced by load_module().

{
   /* This is very simple, we basically change the state on the bridge channel to end and the core takes care of the rest */
   ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_END);
   return 0;
}
static int grab_transfer ( struct ast_channel chan,
char *  exten,
size_t  exten_len,
const char *  context 
) [static]

Helper function that presents dialtone and grabs extension.

Definition at line 48 of file bridge_builtin_features.c.

References ast_app_dtget(), AST_DIGIT_ANY, ast_stopstream(), and ast_stream_and_wait().

Referenced by feature_attended_transfer(), and feature_blind_transfer().

{
   int res;

   /* Play the simple "transfer" prompt out and wait */
   res = ast_stream_and_wait(chan, "pbx-transfer", AST_DIGIT_ANY);
   ast_stopstream(chan);

   /* If the person hit a DTMF digit while the above played back stick it into the buffer */
   if (res) {
      exten[0] = (char)res;
   }

   /* Drop to dialtone so they can enter the extension they want to transfer to */
   res = ast_app_dtget(chan, context, exten, exten_len, 100, 1000);

   return res;
}
static int unload_module ( void  ) [static]

Definition at line 240 of file bridge_builtin_features.c.

{
   return 0;
}

Variable Documentation

struct ast_module_info __MODULE_INFO_SECTION __mod_info = { __MODULE_INFO_GLOBALS .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "Built in bridging features" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, } [static]

Definition at line 257 of file bridge_builtin_features.c.

Definition at line 257 of file bridge_builtin_features.c.