action = function(host, port)
        local owner = ""

        local client_ident = nmap.new_socket()
        local client_service = nmap.new_socket()

        local catch = function()
                client_ident:close()
                client_service:close()
        end

        local try = nmap.new_try(catch)

        try(client_ident:connect(host.ip, 113))
        try(client_service:connect(host.ip, port.number))

        local localip, localport, remoteip, remoteport =
                try(client_service:get_info())

        local request = port.number .. ", " .. localport .. "\r\n"

        try(client_ident:send(request))

        owner = try(client_ident:receive_lines(1))

        if string.match(owner, "ERROR") then 
                owner = nil
        else
                owner = string.match(owner,
                        "%d+%s*,%s*%d+%s*:%s*USERID%s*:%s*.+%s*:%s*(.+)\r?\n")
        end

        try(client_ident:close())
        try(client_service:close())

        return owner
end