ARI: Add the ability to intercept hold and raise an event

For some applications - such as SLA - a phone pressing hold should not behave
in the fashion that the Asterisk core would like it to. Instead, the hold
action has some application specific behaviour associated with it - such as
disconnecting the channel that initiated the hold; only playing MoH to channels
in the bridge if the channels are of a particular type, etc.

One way of accomplishing this is to use a framehook to intercept the
hold/unhold frames, raise an event, and eat the frame. Tasty. This patch
accomplishes that using a new dialplan function, HOLD_INTERCEPT.

In addition, some general cleanup of raising hold/unhold Stasis messages was
done, including removing some RAII_VAR usage.

Review: https://reviewboard.asterisk.org/r/4549/

ASTERISK-24922 #close
........

Merged revisions 434216 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@434217 65c4cc65-6c06-0410-ace0-fbb531ad65f3

4 files changed, 69 insertions, 10 deletions

diff --git a/main/bridge_channel.c b/main/bridge_channel.c
index 29e7cf0f6..c25d827cb 100644
--- a/main/bridge_channel.c
+++ b/main/bridge_channel.c
@@ -979,7 +979,8 @@ int ast_bridge_channel_write_control_data(struct ast_bridge_channel *bridge_chan
 
 int ast_bridge_channel_write_hold(struct ast_bridge_channel *bridge_channel, const char *moh_class)
 {
-	RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
+	struct ast_json *blob;
+	int res;
 	size_t datalen;
 
 	if (!ast_strlen_zero(moh_class)) {
@@ -990,12 +991,16 @@ int ast_bridge_channel_write_hold(struct ast_bridge_channel *bridge_channel, con
 	} else {
 		moh_class = NULL;
 		datalen = 0;
+		blob = NULL;
 	}
 
 	ast_channel_publish_cached_blob(bridge_channel->chan, ast_channel_hold_type(), blob);
 
-	return ast_bridge_channel_write_control_data(bridge_channel, AST_CONTROL_HOLD,
+	res = ast_bridge_channel_write_control_data(bridge_channel, AST_CONTROL_HOLD,
 		moh_class, datalen);
+
+	ast_json_unref(blob);
+	return res;
 }
 
 int ast_bridge_channel_write_unhold(struct ast_bridge_channel *bridge_channel)
diff --git a/main/channel.c b/main/channel.c
index a9c3009fe..2d1b6ddd1 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -1196,8 +1196,8 @@ int ast_queue_hangup_with_cause(struct ast_channel *chan, int cause)
 
 int ast_queue_hold(struct ast_channel *chan, const char *musicclass)
 {
-	RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
 	struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = AST_CONTROL_HOLD };
+	struct ast_json *blob = NULL;
 	int res;
 
 	if (!ast_strlen_zero(musicclass)) {
@@ -1212,6 +1212,8 @@ int ast_queue_hold(struct ast_channel *chan, const char *musicclass)
 
 	res = ast_queue_frame(chan, &f);
 
+	ast_json_unref(blob);
+
 	return res;
 }
 
diff --git a/main/manager_channels.c b/main/manager_channels.c
index f6dc46cec..3aaab92d0 100644
--- a/main/manager_channels.c
+++ b/main/manager_channels.c
@@ -1061,20 +1061,22 @@ static void channel_hold_cb(void *data, struct stasis_subscription *sub,
 	struct stasis_message *message)
 {
 	struct ast_channel_blob *obj = stasis_message_data(message);
-	const char *musicclass;
-	RAII_VAR(struct ast_str *, musicclass_string, NULL, ast_free);
-	RAII_VAR(struct ast_str *, channel_event_string, NULL, ast_free);
+	struct ast_str *musicclass_string = ast_str_create(32);
+	struct ast_str *channel_event_string;
 
-	if (!(musicclass_string = ast_str_create(32))) {
+	if (!musicclass_string) {
 		return;
 	}
 
 	channel_event_string = ast_manager_build_channel_state_string(obj->snapshot);
 	if (!channel_event_string) {
+		ast_free(musicclass_string);
 		return;
 	}
 
 	if (obj->blob) {
+		const char *musicclass;
+
 		musicclass = ast_json_string_get(ast_json_object_get(obj->blob, "musicclass"));
 
 		if (!ast_strlen_zero(musicclass)) {
@@ -1087,13 +1089,16 @@ static void channel_hold_cb(void *data, struct stasis_subscription *sub,
 		"%s",
 		ast_str_buffer(channel_event_string),
 		ast_str_buffer(musicclass_string));
+
+	ast_free(musicclass_string);
+	ast_free(channel_event_string);
 }
 
 static void channel_unhold_cb(void *data, struct stasis_subscription *sub,
 	struct stasis_message *message)
 {
 	struct ast_channel_blob *obj = stasis_message_data(message);
-	RAII_VAR(struct ast_str *, channel_event_string, NULL, ast_free);
+	struct ast_str *channel_event_string;
 
 	channel_event_string = ast_manager_build_channel_state_string(obj->snapshot);
 	if (!channel_event_string) {
@@ -1103,6 +1108,8 @@ static void channel_unhold_cb(void *data, struct stasis_subscription *sub,
 	manager_event(EVENT_FLAG_CALL, "Unhold",
 		"%s",
 		ast_str_buffer(channel_event_string));
+
+	ast_free(channel_event_string);
 }
 
 static void manager_channels_shutdown(void)
diff --git a/main/stasis_channels.c b/main/stasis_channels.c
index 85abe58bc..968afbd7d 100644
--- a/main/stasis_channels.c
+++ b/main/stasis_channels.c
@@ -1136,6 +1136,47 @@ static struct ast_json *talking_stop_to_json(struct stasis_message *message,
 	return channel_blob_to_json(message, "ChannelTalkingFinished", sanitize);
 }
 
+static struct ast_json *hold_to_json(struct stasis_message *message,
+	const struct stasis_message_sanitizer *sanitize)
+{
+	struct ast_channel_blob *channel_blob = stasis_message_data(message);
+	struct ast_json *blob = channel_blob->blob;
+	struct ast_channel_snapshot *snapshot = channel_blob->snapshot;
+	const char *musicclass = ast_json_string_get(ast_json_object_get(blob, "musicclass"));
+	const struct timeval *tv = stasis_message_timestamp(message);
+	struct ast_json *json_channel;
+
+	json_channel = ast_channel_snapshot_to_json(snapshot, sanitize);
+	if (!json_channel) {
+		return NULL;
+	}
+
+	return ast_json_pack("{s: s, s: o, s: s, s: o}",
+		"type", "ChannelHold",
+		"timestamp", ast_json_timeval(*tv, NULL),
+		"musicclass", S_OR(musicclass, "N/A"),
+		"channel", json_channel);
+}
+
+static struct ast_json *unhold_to_json(struct stasis_message *message,
+	const struct stasis_message_sanitizer *sanitize)
+{
+	struct ast_channel_blob *channel_blob = stasis_message_data(message);
+	struct ast_channel_snapshot *snapshot = channel_blob->snapshot;
+	const struct timeval *tv = stasis_message_timestamp(message);
+	struct ast_json *json_channel;
+
+	json_channel = ast_channel_snapshot_to_json(snapshot, sanitize);
+	if (!json_channel) {
+		return NULL;
+	}
+
+	return ast_json_pack("{s: s, s: o, s: o}",
+		"type", "ChannelUnhold",
+		"timestamp", ast_json_timeval(*tv, NULL),
+		"channel", json_channel);
+}
+
 /*!
  * @{ \brief Define channel message types.
  */
@@ -1154,8 +1195,12 @@ STASIS_MESSAGE_TYPE_DEFN(ast_channel_dtmf_begin_type);
 STASIS_MESSAGE_TYPE_DEFN(ast_channel_dtmf_end_type,
 	.to_json = dtmf_end_to_json,
 	);
-STASIS_MESSAGE_TYPE_DEFN(ast_channel_hold_type);
-STASIS_MESSAGE_TYPE_DEFN(ast_channel_unhold_type);
+STASIS_MESSAGE_TYPE_DEFN(ast_channel_hold_type,
+	.to_json = hold_to_json,
+	);
+STASIS_MESSAGE_TYPE_DEFN(ast_channel_unhold_type,
+	.to_json = unhold_to_json,
+	);
 STASIS_MESSAGE_TYPE_DEFN(ast_channel_chanspy_start_type);
 STASIS_MESSAGE_TYPE_DEFN(ast_channel_chanspy_stop_type);
 STASIS_MESSAGE_TYPE_DEFN(ast_channel_fax_type);