Wed Apr 6 11:29:53 2011

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"

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 __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "Built in bridging features" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "8586c2a7d357cb591cc3a6607a8f62d1" , .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, }
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_channel::bridge.

Referenced by feature_attended_transfer().

00132 {
00133    struct ast_bridge_channel *called_bridge_channel = NULL;
00134 
00135    /* 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 */
00136    ao2_lock(bridge);
00137 
00138    if (AST_LIST_FIRST(&bridge->channels) != bridge_channel) {
00139       called_bridge_channel = AST_LIST_FIRST(&bridge->channels);
00140    } else {
00141       called_bridge_channel = AST_LIST_LAST(&bridge->channels);
00142    }
00143 
00144    /* 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. */
00145    if (called_bridge_channel) {
00146       ast_bridge_change_state(called_bridge_channel, AST_BRIDGE_CHANNEL_STATE_HANGUP);
00147    }
00148 
00149    ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_END);
00150 
00151    ao2_unlock(bridge);
00152 
00153    return 0;
00154 }

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().

00124 {
00125    /* 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 */
00126    ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_DEPART);
00127    return 0;
00128 }

static struct ast_channel* dial_transfer ( const struct ast_channel caller,
const char *  exten,
const char *  context 
) [static]

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(), ast_channel::caller, and cause.

Referenced by feature_attended_transfer(), and feature_blind_transfer().

00069 {
00070    char destination[AST_MAX_EXTENSION+AST_MAX_CONTEXT+1] = "";
00071    struct ast_channel *chan = NULL;
00072    int cause;
00073 
00074    /* Fill the variable with the extension and context we want to call */
00075    snprintf(destination, sizeof(destination), "%s@%s", exten, context);
00076 
00077    /* Now we request that chan_local prepare to call the destination */
00078    if (!(chan = ast_request("Local", caller->nativeformats, caller, destination, &cause))) {
00079       return NULL;
00080    }
00081 
00082    /* Before we actually dial out let's inherit the appropriate dialplan variables */
00083    ast_channel_inherit_variables(caller, chan);
00084 
00085    /* Since the above worked fine now we actually call it and return the channel */
00086    if (ast_call(chan, destination, 0)) {
00087       ast_hangup(chan);
00088       return NULL;
00089    }
00090 
00091    return chan;
00092 }

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, 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().

00158 {
00159    char exten[AST_MAX_EXTENSION] = "";
00160    struct ast_channel *chan = NULL;
00161    struct ast_bridge *attended_bridge = NULL;
00162    struct ast_bridge_features caller_features, called_features;
00163    enum ast_bridge_channel_state attended_bridge_result;
00164    struct ast_bridge_features_attended_transfer *attended_transfer = hook_pvt;
00165    const char *context = (attended_transfer && !ast_strlen_zero(attended_transfer->context) ? attended_transfer->context : bridge_channel->chan->context);
00166 
00167    /* Grab the extension to transfer to */
00168    if (!grab_transfer(bridge_channel->chan, exten, sizeof(exten), context)) {
00169       ast_stream_and_wait(bridge_channel->chan, "pbx-invalid", AST_DIGIT_ANY);
00170       ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
00171       return 0;
00172    }
00173 
00174    /* Get a channel that is the destination we wish to call */
00175    if (!(chan = dial_transfer(bridge_channel->chan, exten, context))) {
00176       ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY);
00177       ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
00178       return 0;
00179    }
00180 
00181    /* Create a bridge to use to talk to the person we are calling */
00182    if (!(attended_bridge = ast_bridge_new(AST_BRIDGE_CAPABILITY_1TO1MIX, 0))) {
00183       ast_hangup(chan);
00184       ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY);
00185       ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
00186       return 0;
00187    }
00188 
00189    /* Setup our called features structure so that if they hang up we immediately get thrown out of the bridge */
00190    ast_bridge_features_init(&called_features);
00191    ast_bridge_features_set_flag(&called_features, AST_BRIDGE_FLAG_DISSOLVE);
00192 
00193    /* This is how this is going down, we are imparting the channel we called above into this bridge first */
00194    ast_bridge_impart(attended_bridge, chan, NULL, &called_features);
00195 
00196    /* Before we join setup a features structure with the hangup option, just in case they want to use DTMF */
00197    ast_bridge_features_init(&caller_features);
00198    ast_bridge_features_enable(&caller_features, AST_BRIDGE_BUILTIN_HANGUP,
00199                (attended_transfer && !ast_strlen_zero(attended_transfer->complete) ? attended_transfer->complete : "*1"), NULL);
00200    ast_bridge_features_hook(&caller_features, (attended_transfer && !ast_strlen_zero(attended_transfer->threeway) ? attended_transfer->threeway : "*2"),
00201              attended_threeway_transfer, NULL);
00202    ast_bridge_features_hook(&caller_features, (attended_transfer && !ast_strlen_zero(attended_transfer->abort) ? attended_transfer->abort : "*3"),
00203              attended_abort_transfer, NULL);
00204 
00205    /* 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 */
00206    attended_bridge_result = ast_bridge_join(attended_bridge, bridge_channel->chan, NULL, &caller_features);
00207 
00208    /* Since the above returned the caller features structure is of no more use */
00209    ast_bridge_features_cleanup(&caller_features);
00210 
00211    /* Drop the channel we are transferring to out of the above bridge since it has ended */
00212    if ((attended_bridge_result != AST_BRIDGE_CHANNEL_STATE_HANGUP) && !ast_bridge_depart(attended_bridge, chan)) {
00213       /* If the user wants to turn this into a threeway transfer then do so, otherwise they take our place */
00214       if (attended_bridge_result == AST_BRIDGE_CHANNEL_STATE_DEPART) {
00215          /* We want to impart them upon the bridge and just have us return to it as normal */
00216          ast_bridge_impart(bridge, chan, NULL, NULL);
00217       } else {
00218          ast_bridge_impart(bridge, chan, bridge_channel->chan, NULL);
00219       }
00220    } else {
00221       ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY);
00222       ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
00223    }
00224 
00225    /* Now that all channels are out of it we can destroy the bridge and the called features structure */
00226    ast_bridge_features_cleanup(&called_features);
00227    ast_bridge_destroy(attended_bridge);
00228 
00229    return 0;
00230 }

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, ast_channel::context, ast_bridge_features_blind_transfer::context, context, dial_transfer(), exten, and grab_transfer().

Referenced by load_module().

00096 {
00097    char exten[AST_MAX_EXTENSION] = "";
00098    struct ast_channel *chan = NULL;
00099    struct ast_bridge_features_blind_transfer *blind_transfer = hook_pvt;
00100    const char *context = (blind_transfer && !ast_strlen_zero(blind_transfer->context) ? blind_transfer->context : bridge_channel->chan->context);
00101 
00102    /* Grab the extension to transfer to */
00103    if (!grab_transfer(bridge_channel->chan, exten, sizeof(exten), context)) {
00104       ast_stream_and_wait(bridge_channel->chan, "pbx-invalid", AST_DIGIT_ANY);
00105       ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
00106       return 0;
00107    }
00108 
00109    /* Get a channel that is the destination we wish to call */
00110    if (!(chan = dial_transfer(bridge_channel->chan, exten, context))) {
00111       ast_stream_and_wait(bridge_channel->chan, "beeperr", AST_DIGIT_ANY);
00112       ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_WAIT);
00113       return 0;
00114    }
00115 
00116    /* This is sort of the fun part. We impart the above channel onto the bridge, and have it take our place. */
00117    ast_bridge_impart(bridge, chan, bridge_channel->chan, NULL);
00118 
00119    return 0;
00120 }

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().

00234 {
00235    /* This is very simple, we basically change the state on the bridge channel to end and the core takes care of the rest */
00236    ast_bridge_change_state(bridge_channel, AST_BRIDGE_CHANNEL_STATE_END);
00237    return 0;
00238 }

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(), ast_stream_and_wait(), and asent::chan.

Referenced by feature_attended_transfer(), and feature_blind_transfer().

00049 {
00050    int res;
00051 
00052    /* Play the simple "transfer" prompt out and wait */
00053    res = ast_stream_and_wait(chan, "pbx-transfer", AST_DIGIT_ANY);
00054    ast_stopstream(chan);
00055 
00056    /* If the person hit a DTMF digit while the above played back stick it into the buffer */
00057    if (res) {
00058       exten[0] = (char)res;
00059    }
00060 
00061    /* Drop to dialtone so they can enter the extension they want to transfer to */
00062    res = ast_app_dtget(chan, context, exten, exten_len, 100, 1000);
00063 
00064    return res;
00065 }

static int load_module ( void   )  [static]

Definition at line 245 of file bridge_builtin_features.c.

References AST_BRIDGE_BUILTIN_ATTENDEDTRANSFER, AST_BRIDGE_BUILTIN_BLINDTRANSFER, AST_BRIDGE_BUILTIN_HANGUP, ast_bridge_features_register(), AST_MODULE_LOAD_SUCCESS, ast_module_ref(), feature_attended_transfer(), feature_blind_transfer(), and feature_hangup().

static int unload_module ( void   )  [static]

Definition at line 240 of file bridge_builtin_features.c.

00241 {
00242    return 0;
00243 }


Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "Built in bridging features" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "8586c2a7d357cb591cc3a6607a8f62d1" , .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_DEFAULT, } [static]

Definition at line 257 of file bridge_builtin_features.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 257 of file bridge_builtin_features.c.


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