framehooks: Add callback for determining if a hook is consuming frames of a specific type.

In the past framehooks have had no capability to determine what frame types a hook
is actually interested in consuming. This has meant that code has had to assume they
want all frames, thus preventing native bridging.

This change adds a callback which allows a framehook to be queried for whether it
is consuming a frame of a specific type. The native RTP bridging module has also
been updated to take advantange of this, allowing native bridging to occur when
previously it would not.

ASTERISK-23497 #comment Reported by: Etienne Lessard
ASTERISK-23497 #close

Review: https://reviewboard.asterisk.org/r/3522/


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@413681 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/bridge_basic.c

@@ -2614,6 +2614,12 @@ static struct ast_frame *transfer_target_framehook_cb(struct ast_channel *chan,
 	return frame;
 }
 
+/*! \brief Callback function which informs upstream if we are consuming a frame of a specific type */
+static int transfer_target_framehook_consume(void *data, enum ast_frame_type type)
+{
+	return (type == AST_FRAME_CONTROL ? 1 : 0);
+}
+
 static void transfer_target_framehook_destroy_cb(void *data)
 {
 	struct attended_transfer_properties *props = data;
@@ -2847,6 +2853,7 @@ static int attach_framehook(struct attended_transfer_properties *props, struct a
 		.version = AST_FRAMEHOOK_INTERFACE_VERSION,
 		.event_cb = transfer_target_framehook_cb,
 		.destroy_cb = transfer_target_framehook_destroy_cb,
+		.consume_cb = transfer_target_framehook_consume,
 	};
 
 	ao2_ref(props, +1);

main/channel.c

@@ -2668,6 +2668,13 @@ int ast_channel_has_audio_frame_or_monitor(struct ast_channel *chan)
 		|| !ast_framehook_list_contains_no_active(ast_channel_framehooks(chan));
 }
 
+int ast_channel_has_hook_requiring_audio(struct ast_channel *chan)
+{
+	return ast_channel_monitor(chan)
+		|| !ast_audiohook_write_list_empty(ast_channel_audiohooks(chan))
+		|| !ast_framehook_list_contains_no_active_of_type(ast_channel_framehooks(chan), AST_FRAME_VOICE);
+}
+
 static void destroy_hooks(struct ast_channel *chan)
 {
 	if (ast_channel_audiohooks(chan)) {

main/framehook.c

@@ -160,6 +160,10 @@ int ast_framehook_attach(struct ast_channel *chan, struct ast_framehook_interfac
 		ast_frfree(frame);
 	}
 
+	if (ast_channel_is_bridged(chan)) {
+		ast_softhangup_nolock(chan, AST_SOFTHANGUP_UNBRIDGE);
+	}
+
 	return framehook->id;
 }
 
@@ -214,6 +218,12 @@ int ast_framehook_list_is_empty(struct ast_framehook_list *framehooks)
 }
 
 int ast_framehook_list_contains_no_active(struct ast_framehook_list *framehooks)
+{
+	return ast_framehook_list_contains_no_active_of_type(framehooks, 0);
+}
+
+int ast_framehook_list_contains_no_active_of_type(struct ast_framehook_list *framehooks,
+	enum ast_frame_type type)
 {
 	struct ast_framehook *cur;
 
@@ -229,6 +239,9 @@ int ast_framehook_list_contains_no_active(struct ast_framehook_list *framehooks)
 		if (cur->detach_and_destroy_me) {
 			continue;
 		}
+		if (type && cur->i.consume_cb && !cur->i.consume_cb(cur->i.data, type)) {
+			continue;
+		}
 		return 0;
 	}