Add listen_tag function

Author: FinnitoProductions

lib/routelib/routelib.lua

@@ -545,6 +545,9 @@ local function main_configure_router(set, pools, c_in)
         cmd = function(self)
             return self._cmd
         end,
+        listen_tag = function(self)
+            return self._listen_tag
+        end,
         check_child = function(self, child)
             -- ensure this child is a string of a valid pool
             if type(child) ~= "string" then
@@ -610,6 +613,7 @@ local function main_configure_router(set, pools, c_in)
             return id
         end
     }
+    ctx._listen_tag = tag
 
     if set.map then
         -- a prefix map