Anonymous

-- lua module to limit fakeplayers DOS
-- http://aluigi.altervista.org/fakep.htm
-- used if cvar is not set
-- author: reyalp@gmail.co
-- confugration:
-- add fakeplimit.lua to lua_modules
-- set ip_max_clients cvar as desired. If not set, defaults to the value below.
FAKEPLIMIT_VERSION = "1.0"
DEF_IP_MAX_CLIENTS = 3

et.G_Printf = function(...)
      et.G_Print(string.format(unpack(arg)))
end

function IPForClient(clientNum)
-- TODO listen servers may be 'localhost'
   local userinfo = et.trap_GetUserinfo( clientNum ) 
   if userinfo == "" then
      return ""
   end
   local ip = et.Info_ValueForKey( userinfo, "ip" )
-- strip port
   ip = string.sub(ip,string.find(ip,"(%d+%.%d+%.%d+%.%d+)"))
-- et.G_Printf("IPForClient(%d) = [%s]\n",clientNum,ip)
   return ip
end

function et_ClientConnect( clientNum, firstTime, isBot )
   local ip = IPForClient( clientNum )
   local count = 1 -- we count as the first one
   local max = tonumber(et.trap_Cvar_Get( "ip_max_clients" ))
   if not max or max <= 0 then
      max = DEF_IP_MAX_CLIENTS
   end
   -- et.G_Printf("firstTime %d\n",firstTime);
   -- it's probably safe to only do this on firsttime, but checking
   -- every time doesn't hurt much
   
   -- validate userinfo to filter out the people blindly using luigi's code
   local userinfo = et.trap_GetUserinfo( clientNum )
   -- et.G_Printf("userinfo: [%s]\n",userinfo)
   if et.Info_ValueForKey( userinfo, "rate" ) == "" then 
      et.G_Printf("fakeplimit.lua: invalid userinfo from %s\n",ip)
      return "invalid connection"
   end

   for i = 0, et.trap_Cvar_Get("sv_maxclients") - 1 do
      -- pers.connected is set correctly for fake players
      -- can't rely on userinfo being empty
      if i ~= clientNum and et.gentity_get(i,"pers.connected") > 0 and ip == IPForClient(i) then
         count = count + 1
         if count > max then
            et.G_Printf("fakeplimit.lua: too many connections from %s\n",ip)
            -- TODO should we drop / ban all connections from this IP ?
            return string.format("only %d connections per IP are allowed on this server",max)
         end
      end
   end
end

function et_InitGame( levelTime, randomSeed, restart )
   et.G_Printf("fakeplimit.lua %s\n",FAKEPLIMIT_VERSION)
end