Merge phase 1 support for the new bridging architecture.

This commit brings in the bridging core, bridging technologies,
and the ConfBridge application.

For usage information on the ConfBridge application please see
the output of "core show application ConfBridge" from the CLI.

For API documentation please see the doxygen page describing the
architecture and the documentation for each API call.

Review: http://reviewboard.digium.com/r/93/


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@180369 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 809 insertions, 0 deletions

diff --git a/apps/app_confbridge.c b/apps/app_confbridge.c
new file mode 100644
index 000000000..058f581ec
--- /dev/null
+++ b/apps/app_confbridge.c
@@ -0,0 +1,809 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2007-2008, Digium, Inc.
+ *
+ * Joshua Colp <jcolp@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief Conference Bridge application
+ *
+ * \author\verbatim Joshua Colp <jcolp@digium.com> \endverbatim
+ *
+ * This is a conference bridge application utilizing the bridging core.
+ * \ingroup applications
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <signal.h>
+
+#include "asterisk/file.h"
+#include "asterisk/logger.h"
+#include "asterisk/channel.h"
+#include "asterisk/pbx.h"
+#include "asterisk/module.h"
+#include "asterisk/lock.h"
+#include "asterisk/app.h"
+#include "asterisk/bridging.h"
+#include "asterisk/musiconhold.h"
+#include "asterisk/say.h"
+#include "asterisk/audiohook.h"
+#include "asterisk/astobj2.h"
+
+/*** DOCUMENTATION
+        <application name="ConfBridge" language="en_US">
+                <synopsis>
+                        Conference bridge application.
+                </synopsis>
+                <syntax>
+                        <parameter name="confno">
+                                <para>The conference number</para>
+                        </parameter>
+                        <parameter name="options">
+                                <optionlist>
+                                        <option name="a">
+                                                <para>Set admin mode.</para>
+                                        </option>
+                                        <option name="A">
+                                                <para>Set marked mode.</para>
+                                        </option>
+                                        <option name="c">
+                                                <para>Announce user(s) count on joining a conference.</para>
+                                        </option>
+                                        <option name="m">
+                                                <para>Set initially muted.</para>
+                                        </option>
+                                        <option name="M" hasparams="optional">
+                                                <para>Enable music on hold when the conference has a single caller. Optionally,
+                                                specify a musiconhold class to use. If one is not provided, it will use the
+                                                channel's currently set music class, or <literal>default</literal>.</para>
+                                                <argument name="class" required="true" />
+                                        </option>
+                                        <option name="1">
+                                                <para>Do not play message when first person enters</para>
+                                        </option>
+                                        <option name="s">
+                                                <para>Present menu (user or admin) when <literal>*</literal> is received
+                                                (send to menu).</para>
+                                        </option>
+                                        <option name="w">
+                                                <para>Wait until the marked user enters the conference.</para>
+                                        </option>
+                                        <option name="q">
+                                                <para>Quiet mode (don't play enter/leave sounds).</para>
+                                        </option>
+				</optionlist>
+		      </parameter>
+                </syntax>
+                <description>
+                        <para>Enters the user into a specified conference bridge. The user can exit the conference by hangup only.</para>
+                        <para>The join sound can be set using the <literal>CONFBRIDGE_JOIN_SOUND</literal> variable and the leave sound can be set using the <literal>CONFBRIDGE_LEAVE_SOUND</literal> variable. These can be unique to the caller.</para>
+                </description>
+        </application>
+***/
+
+/*!
+ * \par Playing back a file to a channel in a conference
+ * You might notice in this application that while playing a sound file
+ * to a channel the actual conference bridge lock is not held. This is done so
+ * that other channels are not blocked from interacting with the conference bridge.
+ * Unfortunately because of this it is possible for things to change after the sound file
+ * is done being played. Data must therefore be checked after reacquiring the conference
+ * bridge lock if it is important.
+ */
+
+static const char *app = "ConfBridge";
+
+enum {
+	OPTION_ADMIN = (1 << 0),             /*!< Set if the caller is an administrator */
+	OPTION_MENU = (1 << 1),              /*!< Set if the caller should have access to the conference bridge IVR menu */
+	OPTION_MUSICONHOLD = (1 << 2),       /*!< Set if music on hold should be played if nobody else is in the conference bridge */
+	OPTION_NOONLYPERSON = (1 << 3),      /*!< Set if the "you are currently the only person in this conference" sound file should not be played */
+	OPTION_STARTMUTED = (1 << 4),        /*!< Set if the caller should be initially set muted */
+	OPTION_ANNOUNCEUSERCOUNT = (1 << 5), /*!< Set if the number of users should be announced to the caller */
+	OPTION_MARKEDUSER = (1 << 6),        /*!< Set if the caller is a marked user */
+	OPTION_WAITMARKED = (1 << 7),        /*!< Set if the conference must wait for a marked user before starting */
+	OPTION_QUIET = (1 << 8),             /*!< Set if no audio prompts should be played */
+};
+
+enum {
+	OPTION_MUSICONHOLD_CLASS,            /*!< If the 'M' option is set, the music on hold class to play */
+	/*This must be the last element */
+	OPTION_ARRAY_SIZE,
+};
+
+AST_APP_OPTIONS(app_opts,{
+	AST_APP_OPTION('A', OPTION_MARKEDUSER),
+	AST_APP_OPTION('a', OPTION_ADMIN),
+	AST_APP_OPTION('c', OPTION_ANNOUNCEUSERCOUNT),
+	AST_APP_OPTION('m', OPTION_MENU),
+	AST_APP_OPTION_ARG('M', OPTION_MUSICONHOLD, OPTION_MUSICONHOLD_CLASS),
+	AST_APP_OPTION('1', OPTION_NOONLYPERSON),
+	AST_APP_OPTION('s', OPTION_STARTMUTED),
+	AST_APP_OPTION('w', OPTION_WAITMARKED),
+	AST_APP_OPTION('q', OPTION_QUIET),
+});
+
+/* Maximum length of a conference bridge name */
+#define MAX_CONF_NAME 32
+
+/* Number of buckets our conference bridges container can have */
+#define CONFERENCE_BRIDGE_BUCKETS 53
+
+/*! \brief The structure that represents a conference bridge */
+struct conference_bridge {
+	char name[MAX_CONF_NAME];                                         /*!< Name of the conference bridge */
+	struct ast_bridge *bridge;                                        /*!< Bridge structure doing the mixing */
+	unsigned int users;                                               /*!< Number of users present */
+	unsigned int markedusers;                                         /*!< Number of marked users present */
+	unsigned int locked:1;                                            /*!< Is this conference bridge locked? */
+	AST_LIST_HEAD_NOLOCK(, conference_bridge_user) users_list;        /*!< List of users participating in the conference bridge */
+	struct ast_channel *playback_chan;                                /*!< Channel used for playback into the conference bridge */
+	ast_mutex_t playback_lock;                                        /*!< Lock used for playback channel */
+};
+
+/*! \brief The structure that represents a conference bridge user */
+struct conference_bridge_user {
+	struct conference_bridge *conference_bridge; /*!< Conference bridge they are participating in */
+	struct ast_channel *chan;                    /*!< Asterisk channel participating */
+	struct ast_flags flags;                      /*!< Flags passed in when the application was called */
+	char *opt_args[OPTION_ARRAY_SIZE];           /*!< Arguments to options passed when application was called */
+	struct ast_bridge_features features;         /*!< Bridge features structure */
+	unsigned int kicked:1;                       /*!< User has been kicked from the conference */
+	AST_LIST_ENTRY(conference_bridge_user) list; /*!< Linked list information */
+};
+
+/*! \brief Container to hold all conference bridges in progress */
+static struct ao2_container *conference_bridges;
+
+static int play_sound_file(struct conference_bridge *conference_bridge, const char *filename);
+
+/*! \brief Hashing function used for conference bridges container */
+static int conference_bridge_hash_cb(const void *obj, const int flags)
+{
+	const struct conference_bridge *conference_bridge = obj;
+	return ast_str_case_hash(conference_bridge->name);
+}
+
+/*! \brief Comparison function used for conference bridges container */
+static int conference_bridge_cmp_cb(void *obj, void *arg, int flags)
+{
+	const struct conference_bridge *conference_bridge0 = obj, *conference_bridge1 = arg;
+	return (!strcasecmp(conference_bridge0->name, conference_bridge1->name) ? CMP_MATCH | CMP_STOP : 0);
+}
+
+/*!
+ * \brief Announce number of users in the conference bridge to the caller
+ *
+ * \param conference_bridge Conference bridge to peek at
+ * \param conference_bridge_user Caller
+ *
+ * \return Returns nothing
+ */
+static void announce_user_count(struct conference_bridge *conference_bridge, struct conference_bridge_user *conference_bridge_user)
+{
+	if (conference_bridge->users == 1) {
+		/* Awww we are the only person in the conference bridge */
+		return;
+	} else if (conference_bridge->users == 2) {
+		/* Eep, there is one other person */
+		if (ast_stream_and_wait(conference_bridge_user->chan, "conf-onlyone", "")) {
+			return;
+		}
+	} else {
+		/* Alas multiple others in here */
+		if (ast_stream_and_wait(conference_bridge_user->chan, "conf-thereare", "")) {
+			return;
+		}
+		if (ast_say_number(conference_bridge_user->chan, conference_bridge->users - 1, "", conference_bridge_user->chan->language, NULL)) {
+			return;
+		}
+		if (ast_stream_and_wait(conference_bridge_user->chan, "conf-otherinparty", "")) {
+			return;
+		}
+	}
+}
+
+/*!
+ * \brief Play back an audio file to a channel
+ *
+ * \param conference_bridge Conference bridge they are in
+ * \param chan Channel to play audio prompt to
+ * \param file Prompt to play
+ *
+ * \return Returns nothing
+ *
+ * \note This function assumes that conference_bridge is locked
+ */
+static void play_prompt_to_channel(struct conference_bridge *conference_bridge, struct ast_channel *chan, const char *file)
+{
+	ao2_unlock(conference_bridge);
+	ast_stream_and_wait(chan, file, "");
+	ao2_lock(conference_bridge);
+}
+
+/*!
+ * \brief Perform post-joining marked specific actions
+ *
+ * \param conference_bridge Conference bridge being joined
+ * \param conference_bridge_user Conference bridge user joining
+ *
+ * \return Returns nothing
+ */
+static void post_join_marked(struct conference_bridge *conference_bridge, struct conference_bridge_user *conference_bridge_user)
+{
+	if (ast_test_flag(&conference_bridge_user->flags, OPTION_MARKEDUSER)) {
+		struct conference_bridge_user *other_conference_bridge_user = NULL;
+
+		/* If we are not the first marked user to join just bail out now */
+		if (conference_bridge->markedusers >= 2) {
+			return;
+		}
+
+		/* Iterate through every participant stopping MOH on them if need be */
+		AST_LIST_TRAVERSE(&conference_bridge->users_list, other_conference_bridge_user, list) {
+			if (other_conference_bridge_user == conference_bridge_user) {
+				continue;
+			}
+			if (ast_test_flag(&other_conference_bridge_user->flags, OPTION_MUSICONHOLD) && !ast_bridge_suspend(conference_bridge->bridge, other_conference_bridge_user->chan)) {
+				ast_moh_stop(other_conference_bridge_user->chan);
+				ast_bridge_unsuspend(conference_bridge->bridge, other_conference_bridge_user->chan);
+			}
+		}
+
+		/* Next play the audio file stating they are going to be placed into the conference */
+		ao2_unlock(conference_bridge);
+		ast_autoservice_start(conference_bridge_user->chan);
+		play_sound_file(conference_bridge, "conf-placeintoconf");
+		ast_autoservice_stop(conference_bridge_user->chan);
+		ao2_lock(conference_bridge);
+
+		/* Finally iterate through and unmute them all */
+		AST_LIST_TRAVERSE(&conference_bridge->users_list, other_conference_bridge_user, list) {
+			if (other_conference_bridge_user == conference_bridge_user) {
+				continue;
+			}
+			other_conference_bridge_user->features.mute = 0;
+		}
+
+	} else {
+		/* If a marked user already exists in the conference bridge we can just bail out now */
+		if (conference_bridge->markedusers) {
+			return;
+		}
+		/* Be sure we are muted so we can't talk to anybody else waiting */
+		conference_bridge_user->features.mute = 1;
+		/* If we have not been quieted play back that they are waiting for the leader */
+		if (!ast_test_flag(&conference_bridge_user->flags, OPTION_QUIET)) {
+			play_prompt_to_channel(conference_bridge, conference_bridge_user->chan, "conf-waitforleader");
+		}
+		/* Start music on hold if needed */
+		/* We need to recheck the markedusers value here. play_prompt_to_channel unlocks the conference bridge, potentially
+		 * allowing a marked user to enter while the prompt was playing
+		 */
+		if (!conference_bridge->markedusers && ast_test_flag(&conference_bridge_user->flags, OPTION_MUSICONHOLD)) {
+			ast_moh_start(conference_bridge_user->chan, conference_bridge_user->opt_args[OPTION_MUSICONHOLD_CLASS], NULL);
+		}
+	}
+}
+
+/*!
+ * \brief Perform post-joining non-marked specific actions
+ *
+ * \param conference_bridge Conference bridge being joined
+ * \param conference_bridge_user Conference bridge user joining
+ *
+ * \return Returns nothing
+ */
+static void post_join_unmarked(struct conference_bridge *conference_bridge, struct conference_bridge_user *conference_bridge_user)
+{
+	/* Play back audio prompt and start MOH if need be if we are the first participant */
+	if (conference_bridge->users == 1) {
+		/* If audio prompts have not been quieted or this prompt quieted play it on out */
+		if (!ast_test_flag(&conference_bridge_user->flags, OPTION_QUIET | OPTION_NOONLYPERSON)) {
+			play_prompt_to_channel(conference_bridge, conference_bridge_user->chan, "conf-onlyperson");
+		}
+		/* If we need to start music on hold on the channel do so now */
+		/* We need to re-check the number of users in the conference bridge here because another conference bridge
+		 * participant could have joined while the above prompt was playing for the first user.
+		 */
+		if (conference_bridge->users == 1 && ast_test_flag(&conference_bridge_user->flags, OPTION_MUSICONHOLD)) {
+			ast_moh_start(conference_bridge_user->chan, conference_bridge_user->opt_args[OPTION_MUSICONHOLD_CLASS], NULL);
+		}
+		return;
+	}
+
+	/* Announce number of users if need be */
+	if (ast_test_flag(&conference_bridge_user->flags, OPTION_ANNOUNCEUSERCOUNT)) {
+		ao2_unlock(conference_bridge);
+		announce_user_count(conference_bridge, conference_bridge_user);
+		ao2_lock(conference_bridge);
+	}
+
+	/* If we are the second participant we may need to stop music on hold on the first */
+	if (conference_bridge->users == 2) {
+		struct conference_bridge_user *first_participant = AST_LIST_FIRST(&conference_bridge->users_list);
+
+		/* Temporarily suspend the above participant from the bridge so we have control to stop MOH if needed */
+		if (ast_test_flag(&first_participant->flags, OPTION_MUSICONHOLD) && !ast_bridge_suspend(conference_bridge->bridge, first_participant->chan)) {
+			ast_moh_stop(first_participant->chan);
+			ast_bridge_unsuspend(conference_bridge->bridge, first_participant->chan);
+		}
+	}
+}
+
+/*!
+ * \brief Destroy a conference bridge
+ *
+ * \param obj The conference bridge object
+ *
+ * \return Returns nothing
+ */
+static void destroy_conference_bridge(void *obj)
+{
+	struct conference_bridge *conference_bridge = obj;
+
+	ast_debug(1, "Destroying conference bridge '%s'\n", conference_bridge->name);
+
+	ast_mutex_destroy(&conference_bridge->playback_lock);
+
+	if (conference_bridge->playback_chan) {
+		struct ast_channel *underlying_channel = conference_bridge->playback_chan->tech->bridged_channel(conference_bridge->playback_chan, NULL);
+		ast_hangup(underlying_channel);
+		ast_hangup(conference_bridge->playback_chan);
+		conference_bridge->playback_chan = NULL;
+	}
+
+	/* Destroying a conference bridge is simple, all we have to do is destroy the bridging object */
+	if (conference_bridge->bridge) {
+		ast_bridge_destroy(conference_bridge->bridge);
+		conference_bridge->bridge = NULL;
+	}
+}
+
+/*!
+ * \brief Join a conference bridge
+ *
+ * \param name The conference name
+ * \param conference_bridge_user Conference bridge user structure
+ *
+ * \return A pointer to the conference bridge struct, or NULL if the conference room wasn't found.
+ */
+static struct conference_bridge *join_conference_bridge(const char *name, struct conference_bridge_user *conference_bridge_user)
+{
+	struct conference_bridge *conference_bridge = NULL;
+	struct conference_bridge tmp;
+
+	ast_copy_string(tmp.name, name, sizeof(tmp.name));
+
+	/* We explictly lock the conference bridges container ourselves so that other callers can not create duplicate conferences at the same */
+	ao2_lock(conference_bridges);
+
+	ast_debug(1, "Trying to find conference bridge '%s'\n", name);
+
+	/* Attempt to find an existing conference bridge */
+	conference_bridge = ao2_find(conference_bridges, &tmp, OBJ_POINTER);
+
+	/* When finding a conference bridge that already exists make sure that it is not locked, and if so that we are not an admin */
+	if (conference_bridge && conference_bridge->locked && !ast_test_flag(&conference_bridge_user->flags, OPTION_ADMIN)) {
+		ao2_unlock(conference_bridges);
+		ao2_ref(conference_bridge, -1);
+		ast_debug(1, "Conference bridge '%s' is locked and caller is not an admin\n", name);
+		ast_stream_and_wait(conference_bridge_user->chan, "conf-locked", "");
+		return NULL;
+	}
+
+	/* If no conference bridge was found see if we can create one */
+	if (!conference_bridge) {
+		/* Try to allocate memory for a new conference bridge, if we fail... this won't end well. */
+		if (!(conference_bridge = ao2_alloc(sizeof(*conference_bridge), destroy_conference_bridge))) {
+			ao2_unlock(conference_bridges);
+			ast_log(LOG_ERROR, "Conference bridge '%s' does not exist.\n", name);
+			return NULL;
+		}
+
+		/* Setup conference bridge parameters */
+		ast_copy_string(conference_bridge->name, name, sizeof(conference_bridge->name));
+
+		/* Create an actual bridge that will do the audio mixing */
+		if (!(conference_bridge->bridge = ast_bridge_new(AST_BRIDGE_CAPABILITY_1TO1MIX, AST_BRIDGE_FLAG_SMART))) {
+			ao2_ref(conference_bridge, -1);
+			conference_bridge = NULL;
+			ao2_unlock(conference_bridges);
+			ast_log(LOG_ERROR, "Conference bridge '%s' could not be created.\n", name);
+			return NULL;
+		}
+
+		/* Setup lock for playback channel */
+		ast_mutex_init(&conference_bridge->playback_lock);
+
+		/* Link it into the conference bridges container */
+		ao2_link(conference_bridges, conference_bridge);
+
+		ast_debug(1, "Created conference bridge '%s' and linked to container '%p'\n", name, conference_bridges);
+	}
+
+	ao2_unlock(conference_bridges);
+
+	/* Setup conference bridge user parameters */
+	conference_bridge_user->conference_bridge = conference_bridge;
+
+	ao2_lock(conference_bridge);
+
+	/* All good to go, add them in */
+	AST_LIST_INSERT_TAIL(&conference_bridge->users_list, conference_bridge_user, list);
+
+	/* Increment the users count on the bridge, but record it as it is going to need to be known right after this */
+	conference_bridge->users++;
+
+	/* If the caller is a marked user bump up the count */
+	if (ast_test_flag(&conference_bridge_user->flags, OPTION_MARKEDUSER)) {
+		conference_bridge->markedusers++;
+	}
+
+	/* If the caller is a marked user or is waiting for a marked user to enter pass 'em off, otherwise pass them off to do regular joining stuff */
+	if (ast_test_flag(&conference_bridge_user->flags, OPTION_MARKEDUSER | OPTION_WAITMARKED)) {
+		post_join_marked(conference_bridge, conference_bridge_user);
+	} else {
+		post_join_unmarked(conference_bridge, conference_bridge_user);
+	}
+
+	ao2_unlock(conference_bridge);
+
+	return conference_bridge;
+}
+
+/*!
+ * \brief Leave a conference bridge
+ *
+ * \param conference_bridge The conference bridge to leave
+ * \param conference_bridge_user The conference bridge user structure
+ *
+ */
+static void  leave_conference_bridge(struct conference_bridge *conference_bridge, struct conference_bridge_user *conference_bridge_user)
+{
+	ao2_lock(conference_bridge);
+
+	/* If this caller is a marked user bump down the count */
+	if (ast_test_flag(&conference_bridge_user->flags, OPTION_MARKEDUSER)) {
+		conference_bridge->markedusers--;
+	}
+
+	/* Decrement the users count while keeping the previous participant count */
+	conference_bridge->users--;
+
+	/* Drop conference bridge user from the list, they be going bye bye */
+	AST_LIST_REMOVE(&conference_bridge->users_list, conference_bridge_user, list);
+
+	/* If there are still users in the conference bridge we may need to do things (such as start MOH on them) */
+	if (conference_bridge->users) {
+		if (ast_test_flag(&conference_bridge_user->flags, OPTION_MARKEDUSER) && !conference_bridge->markedusers) {
+			struct conference_bridge_user *other_participant = NULL;
+
+			/* Start out with muting everyone */
+			AST_LIST_TRAVERSE(&conference_bridge->users_list, other_participant, list) {
+				other_participant->features.mute = 1;
+			}
+
+			/* Play back the audio prompt saying the leader has left the conference */
+			ao2_unlock(conference_bridge);
+			ast_autoservice_start(conference_bridge_user->chan);
+			play_sound_file(conference_bridge, "conf-leaderhasleft");
+			ast_autoservice_stop(conference_bridge_user->chan);
+			ao2_lock(conference_bridge);
+
+			/* Now on to starting MOH if needed */
+			AST_LIST_TRAVERSE(&conference_bridge->users_list, other_participant, list) {
+				if (ast_test_flag(&other_participant->flags, OPTION_MUSICONHOLD) && !ast_bridge_suspend(conference_bridge->bridge, other_participant->chan)) {
+					ast_moh_start(other_participant->chan, other_participant->opt_args[OPTION_MUSICONHOLD_CLASS], NULL);
+					ast_bridge_unsuspend(conference_bridge->bridge, other_participant->chan);
+				}
+			}
+		} else if (conference_bridge->users == 1) {
+			/* Of course if there is one other person in here we may need to start up MOH on them */
+			struct conference_bridge_user *first_participant = AST_LIST_FIRST(&conference_bridge->users_list);
+
+			if (ast_test_flag(&first_participant->flags, OPTION_MUSICONHOLD) && !ast_bridge_suspend(conference_bridge->bridge, first_participant->chan)) {
+				ast_moh_start(first_participant->chan, first_participant->opt_args[OPTION_MUSICONHOLD_CLASS], NULL);
+				ast_bridge_unsuspend(conference_bridge->bridge, first_participant->chan);
+			}
+		}
+	} else {
+		ao2_unlink(conference_bridges, conference_bridge);
+	}
+
+	/* Done mucking with the conference bridge, huzzah */
+	ao2_unlock(conference_bridge);
+
+	ao2_ref(conference_bridge, -1);
+}
+
+/*!
+ * \brief Play sound file into conference bridge
+ *
+ * \param conference_bridge The conference bridge to play sound file into
+ * \param filename Sound file to play
+ *
+ * \retval 0 success
+ * \retval -1 failure
+ */
+static int play_sound_file(struct conference_bridge *conference_bridge, const char *filename)
+{
+	struct ast_channel *underlying_channel;
+
+	ast_mutex_lock(&conference_bridge->playback_lock);
+
+	if (!(conference_bridge->playback_chan)) {
+		int cause;
+
+		if (!(conference_bridge->playback_chan = ast_request("Bridge", AST_FORMAT_SLINEAR, "", &cause))) {
+			ast_mutex_unlock(&conference_bridge->playback_lock);
+			return -1;
+		}
+
+		conference_bridge->playback_chan->bridge = conference_bridge->bridge;
+
+		if (ast_call(conference_bridge->playback_chan, "", 0)) {
+			ast_hangup(conference_bridge->playback_chan);
+			conference_bridge->playback_chan = NULL;
+			ast_mutex_unlock(&conference_bridge->playback_lock);
+			return -1;
+		}
+
+		ast_debug(1, "Created a playback channel to conference bridge '%s'\n", conference_bridge->name);
+
+		underlying_channel = conference_bridge->playback_chan->tech->bridged_channel(conference_bridge->playback_chan, NULL);
+	} else {
+		/* Channel was already available so we just need to add it back into the bridge */
+		underlying_channel = conference_bridge->playback_chan->tech->bridged_channel(conference_bridge->playback_chan, NULL);
+		ast_bridge_impart(conference_bridge->bridge, underlying_channel, NULL, NULL);
+	}
+
+	/* The channel is all under our control, in goes the prompt */
+	ast_stream_and_wait(conference_bridge->playback_chan, filename, "");
+
+	ast_debug(1, "Departing underlying channel '%s' from bridge '%p'\n", underlying_channel->name, conference_bridge->bridge);
+	ast_bridge_depart(conference_bridge->bridge, underlying_channel);
+
+	ast_mutex_unlock(&conference_bridge->playback_lock);
+
+	return 0;
+}
+
+/*!
+ * \brief DTMF Menu Callback
+ *
+ * \param bridge Bridge this is involving
+ * \param bridge_channel Bridged channel this is involving
+ * \param hook_pvt User's conference bridge structure
+ *
+ * \retval 0 success
+ * \retval -1 failure
+ */
+static int menu_callback(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, void *hook_pvt)
+{
+	struct conference_bridge_user *conference_bridge_user = hook_pvt;
+	struct conference_bridge *conference_bridge = conference_bridge_user->conference_bridge;
+	int digit, res = 0, isadmin = ast_test_flag(&conference_bridge_user->flags, OPTION_ADMIN);
+
+	/* See if music on hold is playing */
+	ao2_lock(conference_bridge);
+	if (conference_bridge->users == 1 && ast_test_flag(&conference_bridge_user->flags, OPTION_MUSICONHOLD)) {
+		/* Just us so MOH is probably indeed going, let's stop it */
+		ast_moh_stop(bridge_channel->chan);
+	}
+	ao2_unlock(conference_bridge);
+
+	/* Try to play back the user menu, if it fails pass this back up so the bridging core will act on it */
+	if (ast_streamfile(bridge_channel->chan, (isadmin ? "conf-adminmenu" : "conf-usermenu"), bridge_channel->chan->language)) {
+		res = -1;
+		goto finished;
+	}
+
+	/* Wait for them to enter a digit from the user menu options */
+	digit = ast_waitstream(bridge_channel->chan, AST_DIGIT_ANY);
+	ast_stopstream(bridge_channel->chan);
+
+	if (digit == '1') {
+		/* 1 - Mute or unmute yourself, note we only allow manipulation if they aren't waiting for a marked user or if marked users exist */
+		if (!ast_test_flag(&conference_bridge_user->flags, OPTION_WAITMARKED) || conference_bridge->markedusers) {
+			conference_bridge_user->features.mute = (!conference_bridge_user->features.mute ? 1 : 0);
+		}
+		res = ast_stream_and_wait(bridge_channel->chan, (conference_bridge_user->features.mute ? "conf-muted" : "conf-unmuted"), "");
+	} else if (isadmin && digit == '2') {
+		/* 2 - Unlock or lock conference */
+		conference_bridge->locked = (!conference_bridge->locked ? 1 : 0);
+		res = ast_stream_and_wait(bridge_channel->chan, (conference_bridge->locked ? "conf-lockednow" : "conf-unlockednow"), "");
+	} else if (isadmin && digit == '3') {
+		/* 3 - Eject last user */
+		struct conference_bridge_user *last_participant = NULL;
+
+		ao2_lock(conference_bridge);
+		if (((last_participant = AST_LIST_LAST(&conference_bridge->users_list)) == conference_bridge_user) || (ast_test_flag(&last_participant->flags, OPTION_ADMIN))) {
+			ao2_unlock(conference_bridge);
+			res = ast_stream_and_wait(bridge_channel->chan, "conf-errormenu", "");
+		} else {
+			last_participant->kicked = 1;
+			ast_bridge_remove(conference_bridge->bridge, last_participant->chan);
+			ao2_unlock(conference_bridge);
+		}
+	} else if (digit == '4') {
+		/* 4 - Decrease listening volume */
+		ast_audiohook_volume_adjust(conference_bridge_user->chan, AST_AUDIOHOOK_DIRECTION_WRITE, -1);
+	} else if (digit == '6') {
+		/* 6 - Increase listening volume */
+		ast_audiohook_volume_adjust(conference_bridge_user->chan, AST_AUDIOHOOK_DIRECTION_WRITE, 1);
+	} else if (digit == '7') {
+		/* 7 - Decrease talking volume */
+		ast_audiohook_volume_adjust(conference_bridge_user->chan, AST_AUDIOHOOK_DIRECTION_READ, -1);
+	} else if (digit == '8') {
+		/* 8 - Exit the IVR */
+	} else if (digit == '9') {
+		/* 9 - Increase talking volume */
+		ast_audiohook_volume_adjust(conference_bridge_user->chan, AST_AUDIOHOOK_DIRECTION_READ, 1);
+	} else {
+		/* No valid option was selected */
+		res = ast_stream_and_wait(bridge_channel->chan, "conf-errormenu", "");
+	}
+
+ finished:
+	/* See if music on hold needs to be started back up again */
+	ao2_lock(conference_bridge);
+	if (conference_bridge->users == 1 && ast_test_flag(&conference_bridge_user->flags, OPTION_MUSICONHOLD)) {
+		ast_moh_start(bridge_channel->chan, conference_bridge_user->opt_args[OPTION_MUSICONHOLD_CLASS], NULL);
+	}
+	ao2_unlock(conference_bridge);
+
+	bridge_channel->state = AST_BRIDGE_CHANNEL_STATE_WAIT;
+
+	return res;
+}
+
+/*! \brief The ConfBridge application */
+static int confbridge_exec(struct ast_channel *chan, void *data)
+{
+	int res = 0, volume_adjustments[2];
+	char *parse;
+	struct conference_bridge *conference_bridge = NULL;
+	struct conference_bridge_user conference_bridge_user = {
+		.chan = chan,
+	};
+	const char *tmp, *join_sound = NULL, *leave_sound = NULL;
+	AST_DECLARE_APP_ARGS(args,
+		AST_APP_ARG(conf_name);
+		AST_APP_ARG(options);
+	);
+
+	if (ast_strlen_zero(data)) {
+		ast_log(LOG_WARNING, "%s requires an argument (conference name[,options])\n", app);
+		return -1;
+	}
+
+	/* We need to make a copy of the input string if we are going to modify it! */
+	parse = ast_strdupa(data);
+
+	AST_STANDARD_APP_ARGS(args, parse);
+
+	if (args.argc == 2) {
+		ast_app_parse_options(app_opts, &conference_bridge_user.flags, conference_bridge_user.opt_args, args.options);
+	}
+
+	/* Look for a conference bridge matching the provided name */
+	if (!(conference_bridge = join_conference_bridge(args.conf_name, &conference_bridge_user))) {
+		return -1;
+	}
+
+	/* Keep a copy of volume adjustments so we can restore them later if need be */
+	volume_adjustments[0] = ast_audiohook_volume_get(chan, AST_AUDIOHOOK_DIRECTION_READ);
+	volume_adjustments[1] = ast_audiohook_volume_get(chan, AST_AUDIOHOOK_DIRECTION_WRITE);
+
+	/* Always initialize the features structure, we are in most cases always going to need it. */
+	ast_bridge_features_init(&conference_bridge_user.features);
+
+	/* If the menu option is enabled provide a user or admin menu as a custom feature hook */
+	if (ast_test_flag(&conference_bridge_user.flags, OPTION_MENU)) {
+		ast_bridge_features_hook(&conference_bridge_user.features, "#", menu_callback, &conference_bridge_user);
+	}
+
+	/* If the caller should be joined already muted, make it so */
+	if (ast_test_flag(&conference_bridge_user.flags, OPTION_STARTMUTED)) {
+		conference_bridge_user.features.mute = 1;
+	}
+
+	/* Grab join/leave sounds from the channel */
+	ast_channel_lock(chan);
+	if ((tmp = pbx_builtin_getvar_helper(chan, "CONFBRIDGE_JOIN_SOUND"))) {
+		join_sound = ast_strdupa(tmp);
+	}
+	if ((tmp = pbx_builtin_getvar_helper(chan, "CONFBRIDGE_LEAVE_SOUND"))) {
+		leave_sound = ast_strdupa(tmp);
+	}
+	ast_channel_unlock(chan);
+
+	/* If there is 1 or more people already in the conference then play our join sound unless overridden */
+	if (!ast_test_flag(&conference_bridge_user.flags, OPTION_QUIET) && !ast_strlen_zero(join_sound) && conference_bridge->users >= 2) {
+		ast_autoservice_start(chan);
+		play_sound_file(conference_bridge, join_sound);
+		ast_autoservice_stop(chan);
+	}
+
+	/* Join our conference bridge for real */
+	ast_bridge_join(conference_bridge->bridge, chan, NULL, &conference_bridge_user.features);
+
+	/* If there is 1 or more people (not including us) already in the conference then play our leave sound unless overridden */
+	if (!ast_test_flag(&conference_bridge_user.flags, OPTION_QUIET) && !ast_strlen_zero(leave_sound) && conference_bridge->users >= 2) {
+		ast_autoservice_start(chan);
+		play_sound_file(conference_bridge, leave_sound);
+		ast_autoservice_stop(chan);
+	}
+
+	/* Easy as pie, depart this channel from the conference bridge */
+	leave_conference_bridge(conference_bridge, &conference_bridge_user);
+	conference_bridge = NULL;
+
+	/* Can't forget to clean up the features structure, or else we risk a memory leak */
+	ast_bridge_features_cleanup(&conference_bridge_user.features);
+
+	/* If the user was kicked from the conference play back the audio prompt for it */
+	if (!ast_test_flag(&conference_bridge_user.flags, OPTION_QUIET) && conference_bridge_user.kicked) {
+		res = ast_stream_and_wait(chan, "conf-kicked", "");
+	}
+
+	/* Restore volume adjustments to previous values in case they were changed */
+	if (volume_adjustments[0]) {
+		ast_audiohook_volume_set(chan, AST_AUDIOHOOK_DIRECTION_READ, volume_adjustments[0]);
+	}
+	if (volume_adjustments[1]) {
+		ast_audiohook_volume_set(chan, AST_AUDIOHOOK_DIRECTION_WRITE, volume_adjustments[1]);
+	}
+
+	return res;
+}
+
+/*! \brief Called when module is being unloaded */
+static int unload_module(void)
+{
+	int res = ast_unregister_application(app);
+
+	/* Get rid of the conference bridges container. Since we only allow dynamic ones none will be active. */
+	ao2_ref(conference_bridges, -1);
+
+	return res;
+}
+
+/*! \brief Called when module is being loaded */
+static int load_module(void)
+{
+	/* Create a container to hold the conference bridges */
+	if (!(conference_bridges = ao2_container_alloc(CONFERENCE_BRIDGE_BUCKETS, conference_bridge_hash_cb, conference_bridge_cmp_cb))) {
+		return AST_MODULE_LOAD_DECLINE;
+	}
+
+	if (ast_register_application_xml(app, confbridge_exec)) {
+		ao2_ref(conference_bridges, -1);
+		return AST_MODULE_LOAD_DECLINE;
+	}
+
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Conference Bridge Application");