func_channel: Add CHANNEL(onhold) item to get the current hold status of the channel.

It would be useful to get the current hold status of a channel.

Added CHANNEL(onhold) item that returns 1 (onhold) and 0 (not-onhold) for
the hold status of a channel.

ASTERISK-24038
Reported by: Matt Jordan

AFS-113 #close
Reported by: Mark Michelson

Review: https://reviewboard.asterisk.org/r/3983/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@422870 65c4cc65-6c06-0410-ace0-fbb531ad65f3

funcs/func_channel.c

@@ -156,6 +156,9 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 						and exten are supplied by the channel pushing the handler
 						before it is pushed.</para>
 					</enum>
+					<enum name="onhold">
+						<para>R/O Whether or not the channel is onhold. (1/0)</para>
+					</enum>
 					<enum name="language">
 						<para>R/W language for sounds played.</para>
 					</enum>
@@ -475,7 +478,10 @@ static int func_channel_read(struct ast_channel *chan, const char *function,
 		locked_copy_string(chan, buf, ast_channel_parkinglot(chan), len);
 	else if (!strcasecmp(data, "state"))
 		locked_copy_string(chan, buf, ast_state2str(ast_channel_state(chan)), len);
-	else if (!strcasecmp(data, "channeltype"))
+	else if (!strcasecmp(data, "onhold")) {
+		locked_copy_string(chan, buf,
+			ast_channel_hold_state(chan) == AST_CONTROL_HOLD ? "1" : "0", len);
+	} else if (!strcasecmp(data, "channeltype"))
 		locked_copy_string(chan, buf, ast_channel_tech(chan)->type, len);
 	else if (!strcasecmp(data, "accountcode"))
 		locked_copy_string(chan, buf, ast_channel_accountcode(chan), len);