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path: root/src/echo_server.lua
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--
--  anylike
--
--  anylike is a ...
--  
--
--  Copyright (C) 2007-2008 Markus Grueneis <gimpf@anylike.org>
--                          Christian Pointner <equinox@anylike.org>
--
--  This file is part of anylike.
--
--  anylike is free software: you can redistribute it and/or modify
--  it under the terms of the GNU General Public License as published by
--  the Free Software Foundation, either version 3 of the License, or
--  any later version.
--
--  anylike is distributed in the hope that it will be useful,
--  but WITHOUT ANY WARRANTY; without even the implied warranty of
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--  GNU General Public License for more details.
--
--  You should have received a copy of the GNU General Public License
--  along with anylike. If not, see <http://www.gnu.org/licenses/>.
--

socket = require("socket")

function echo_server_init() 
   local host, port = "localhost", 4500
   local ip, err = socket.dns.toip(host)
   if(ip == nil) then
      log.printf("ERROR", "can't resolve %s: %s", host, err)
      return nil
   end

   local udp, err = socket.udp()
   if(udp == nil) then
      log.printf("ERROR", "can't create udp socket")
      return nil
   end
      
   local ret, err = udp:setsockname(ip, port)
   if(ret == nil) then
      log.printf("ERROR", "setsockname(%s,%s) failed: %s", ip, port, err)
      return nil
   end

   log.printf("NOTICE", "echo server listening on %s:%s", ip, port);

   return udp
end          

function echo_server_recv(udp)
   local dgrm, from_ip, from_port = udp:receivefrom()
   if(dgrm == nil) then
      log.printf("ERROR", "receivefrom(%s,%s) failed: %s", ip, port, from_ip)
      return -1
   end
      
   local ret, err = udp:sendto(dgrm, from_ip, from_port)
   if(ret == nil) then
      log.printf("ERROR", "sendto(%s,%s) failed: %s", ip, port, err)
      return -1
   end
      
   if(string.gsub(dgrm, "^(%w+)%s*%c$", "%1") ==  "quit") then
      return 2
   end

   return 0
end