Merge in the bridge_construction branch to make the system use the Bridging API.

Breaks many things until they can be reworked.  A partial list:
chan_agent
chan_dahdi, chan_misdn, chan_iax2 native bridging
app_queue
COLP updates
DTMF attended transfers
Protocol attended transfers


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@389378 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 311 insertions, 0 deletions

diff --git a/bridges/bridge_holding.c b/bridges/bridge_holding.c
new file mode 100644
index 000000000..fe0a7303f
--- /dev/null
+++ b/bridges/bridge_holding.c
@@ -0,0 +1,311 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013, Digium, Inc.
+ *
+ * Jonathan Rose <jrose@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 Bridging technology for storing channels in a bridge for
+ *        the purpose of holding, parking, queues, and other such
+ *        states where a channel may need to be in a bridge but not
+ *        actually communicating with anything.
+ *
+ * \author Jonathan Rose <jrose@digium.com>
+ *
+ * \ingroup bridges
+ */
+
+/*** MODULEINFO
+	<support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#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/musiconhold.h"
+
+enum role_flags {
+	HOLDING_ROLE_PARTICIPANT = (1 << 0),
+	HOLDING_ROLE_ANNOUNCER = (1 << 1),
+};
+
+/* BUGBUG Add IDLE_MODE_HOLD option to put channel on hold using AST_CONTROL_HOLD/AST_CONTROL_UNHOLD while in bridge */
+/* BUGBUG Add IDLE_MODE_SILENCE to send silence media frames to channel while in bridge (uses a silence generator) */
+/* BUGBUG A channel without the holding_participant role will assume IDLE_MODE_MOH with the default music class. */
+enum idle_modes {
+	IDLE_MODE_NONE = 0,
+	IDLE_MODE_MOH,
+	IDLE_MODE_RINGING,
+};
+
+/*! \brief Structure which contains per-channel role information */
+struct holding_channel {
+	struct ast_flags holding_roles;
+	enum idle_modes idle_mode;
+};
+
+static void participant_stop_hold_audio(struct ast_bridge_channel *bridge_channel)
+{
+	struct holding_channel *hc = bridge_channel->tech_pvt;
+	if (!hc) {
+		return;
+	}
+
+	switch (hc->idle_mode) {
+	case IDLE_MODE_MOH:
+		ast_moh_stop(bridge_channel->chan);
+		break;
+	case IDLE_MODE_RINGING:
+		ast_indicate(bridge_channel->chan, -1);
+		break;
+	case IDLE_MODE_NONE:
+		break;
+	}
+}
+
+static void participant_reaction_announcer_join(struct ast_bridge_channel *bridge_channel)
+{
+	struct ast_channel *chan;
+	chan = bridge_channel->chan;
+	participant_stop_hold_audio(bridge_channel);
+	if (ast_set_write_format_by_id(chan, AST_FORMAT_SLINEAR)) {
+		ast_log(LOG_WARNING, "Could not make participant %s compatible.\n", ast_channel_name(chan));
+	}
+}
+
+/* This should only be called on verified holding_participants. */
+static void participant_start_hold_audio(struct ast_bridge_channel *bridge_channel)
+{
+	struct holding_channel *hc = bridge_channel->tech_pvt;
+	const char *moh_class;
+
+	if (!hc) {
+		return;
+	}
+
+	switch(hc->idle_mode) {
+	case IDLE_MODE_MOH:
+		moh_class = ast_bridge_channel_get_role_option(bridge_channel, "holding_participant", "moh_class");
+		ast_moh_start(bridge_channel->chan, ast_strlen_zero(moh_class) ? NULL : moh_class, NULL);
+		break;
+	case IDLE_MODE_RINGING:
+		ast_indicate(bridge_channel->chan, AST_CONTROL_RINGING);
+		break;
+	case IDLE_MODE_NONE:
+		break;
+	}
+}
+
+static void handle_participant_join(struct ast_bridge_channel *bridge_channel, struct ast_bridge_channel *announcer_channel)
+{
+	struct ast_channel *us = bridge_channel->chan;
+	struct holding_channel *hc = bridge_channel->tech_pvt;
+	const char *idle_mode = ast_bridge_channel_get_role_option(bridge_channel, "holding_participant", "idle_mode");
+
+
+	if (!hc) {
+		return;
+	}
+
+	if (ast_strlen_zero(idle_mode)) {
+		hc->idle_mode = IDLE_MODE_NONE;
+	} else if (!strcmp(idle_mode, "musiconhold")) {
+		hc->idle_mode = IDLE_MODE_MOH;
+	} else if (!strcmp(idle_mode, "ringing")) {
+		hc->idle_mode = IDLE_MODE_RINGING;
+	} else {
+		ast_debug(2, "channel %s idle mode '%s' doesn't match any expected idle mode\n", ast_channel_name(us), idle_mode);
+	}
+
+	/* If the announcer channel isn't present, we need to set up ringing, music on hold, or whatever. */
+	if (!announcer_channel) {
+		participant_start_hold_audio(bridge_channel);
+		return;
+	}
+
+	/* If it is present though, we need to establish compatability. */
+	if (ast_set_write_format_by_id(us, AST_FORMAT_SLINEAR)) {
+		ast_log(LOG_WARNING, "Could not make participant %s compatible.\n", ast_channel_name(us));
+	}
+}
+
+static int holding_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
+{
+	struct ast_bridge_channel *other_channel;
+	struct ast_bridge_channel *announcer_channel;
+	struct holding_channel *hc;
+	struct ast_channel *us = bridge_channel->chan; /* The joining channel */
+
+	if (!(hc = ast_calloc(1, sizeof(*hc)))) {
+		return -1;
+	}
+
+	bridge_channel->tech_pvt = hc;
+
+	/* The bridge pvt holds the announcer channel if we have one. */
+	announcer_channel = bridge->tech_pvt;
+
+	if (ast_bridge_channel_has_role(bridge_channel, "announcer")) {
+		/* If another announcer already exists, scrap the holding channel struct so we know to ignore it in the future */
+		if (announcer_channel) {
+			bridge_channel->tech_pvt = NULL;
+			ast_free(hc);
+			ast_log(LOG_WARNING, "A second announcer channel %s attempted to enter a holding bridge.\n",
+				ast_channel_name(announcer_channel->chan));
+			return -1;
+		}
+
+		bridge->tech_pvt = bridge_channel;
+		ast_set_flag(&hc->holding_roles, HOLDING_ROLE_ANNOUNCER);
+
+		/* The announcer should always be made compatible with signed linear */
+		if (ast_set_read_format_by_id(us, AST_FORMAT_SLINEAR)) {
+			ast_log(LOG_ERROR, "Could not make announcer %s compatible.\n", ast_channel_name(us));
+		}
+
+		/* Make everyone compatible. While we are at it we should stop music on hold and ringing. */
+		AST_LIST_TRAVERSE(&bridge->channels, other_channel, entry) {
+			/* Skip the reaction if we are the channel in question */
+			if (bridge_channel == other_channel) {
+				continue;
+			}
+			participant_reaction_announcer_join(other_channel);
+		}
+
+		return 0;
+	}
+
+	/* If the entering channel isn't an announcer then we need to setup it's properties and put it in its holding state if necessary */
+	ast_set_flag(&hc->holding_roles, HOLDING_ROLE_PARTICIPANT);
+	handle_participant_join(bridge_channel, announcer_channel);
+	return 0;
+}
+
+static void participant_reaction_announcer_leave(struct ast_bridge_channel *bridge_channel)
+{
+	struct holding_channel *hc = bridge_channel->tech_pvt;
+
+	if (!hc) {
+		/* We are dealing with a channel that failed to join properly. Skip it. */
+		return;
+	}
+
+	ast_bridge_channel_restore_formats(bridge_channel);
+	if (ast_test_flag(&hc->holding_roles, HOLDING_ROLE_PARTICIPANT)) {
+		participant_start_hold_audio(bridge_channel);
+	}
+}
+
+static void holding_bridge_leave(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
+{
+	struct ast_bridge_channel *other_channel;
+	struct holding_channel *hc = bridge_channel->tech_pvt;
+
+	if (!hc) {
+		return;
+	}
+
+	if (!ast_test_flag(&hc->holding_roles, HOLDING_ROLE_ANNOUNCER)) {
+		/* It's not an announcer so nothing needs to react to its departure. Just free the tech_pvt. */
+		if (!bridge->tech_pvt) {
+			/* Since no announcer is in the channel, we may be playing MOH/ringing. Stop that. */
+			participant_stop_hold_audio(bridge_channel);
+		}
+		ast_free(hc);
+		bridge_channel->tech_pvt = NULL;
+		return;
+	}
+
+	/* When the announcer leaves, the other channels should reset their formats and go back to moh/ringing */
+	AST_LIST_TRAVERSE(&bridge->channels, other_channel, entry) {
+		participant_reaction_announcer_leave(other_channel);
+	}
+
+	/* Since the announcer is leaving, we should clear the tech_pvt pointing to it */
+	bridge->tech_pvt = NULL;
+
+	ast_free(hc);
+	bridge_channel->tech_pvt = NULL;
+}
+
+static int holding_bridge_write(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
+{
+	struct ast_bridge_channel *cur;
+	struct holding_channel *hc = bridge_channel->tech_pvt;
+
+	/* If there is no tech_pvt, then the channel failed to allocate one when it joined and is borked. Don't listen to him. */
+	if (!hc) {
+		return -1;
+	}
+
+	/* If we aren't an announcer, we never have any business writing anything. */
+	if (!ast_test_flag(&hc->holding_roles, HOLDING_ROLE_ANNOUNCER)) {
+		return -1;
+	}
+
+	/* Ok, so we are the announcer and there are one or more people available to receive our writes. Let's do it. */
+	AST_LIST_TRAVERSE(&bridge->channels, cur, entry) {
+		if (bridge_channel == cur || !cur->tech_pvt) {
+			continue;
+		}
+
+		ast_bridge_channel_queue_frame(cur, frame);
+	}
+
+	return 0;
+}
+
+static struct ast_bridge_technology holding_bridge = {
+	.name = "holding_bridge",
+	.capabilities = AST_BRIDGE_CAPABILITY_HOLDING,
+	.preference = AST_BRIDGE_PREFERENCE_BASE_HOLDING,
+	.write = holding_bridge_write,
+	.join = holding_bridge_join,
+	.leave = holding_bridge_leave,
+};
+
+static int unload_module(void)
+{
+	ast_format_cap_destroy(holding_bridge.format_capabilities);
+	return ast_bridge_technology_unregister(&holding_bridge);
+}
+
+static int load_module(void)
+{
+	if (!(holding_bridge.format_capabilities = ast_format_cap_alloc())) {
+		return AST_MODULE_LOAD_DECLINE;
+	}
+	ast_format_cap_add_all_by_type(holding_bridge.format_capabilities, AST_FORMAT_TYPE_AUDIO);
+	ast_format_cap_add_all_by_type(holding_bridge.format_capabilities, AST_FORMAT_TYPE_VIDEO);
+	ast_format_cap_add_all_by_type(holding_bridge.format_capabilities, AST_FORMAT_TYPE_TEXT);
+
+	return ast_bridge_technology_register(&holding_bridge);
+}
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Holding bridge module");
+