udavac.lua

   1 #!/usr/bin/lua
   2 -- udavacz v1.0
   3 --
   4 -- de-anonimize users behind nat.
   5 -- returns first 9 chars of dns, i.e. your dns
   6 -- better be accurate.
   7 --
   8 -- (c) 2008 kt@leet.cz
   9 --
  10
  11 require "socket"
  12 serv=socket.tcp()
  13 serv:settimeout(0)
  14 serv:setoption("reuseaddr",true)
  15 assert(serv:bind("0.0.0.0",113))
  16 serv:listen(100)
  17
  18 ins={serv}
  19
  20 while true do
  21         local r = socket.select(ins, nil)
  22         if r[serv] then
  23                 local newc=serv:accept()
  24                 table.insert(ins,newc)
  25         else
  26                 for _,v in ipairs(r) do
  27                         local ln = v:receive("*l") or ""
  28                         local p1, p2 = ln:match("^(%d*)[ \t]*,[ \t]*(%d*)")
  29                         if ln and p1 and p2 then socket.protect(function()
  30                                 p1 = tonumber(p1)
  31                                 p2 = tonumber(p2)
  32                                 local remhost, remport = socket.try(v:getpeername())
  33                                 local rp=io.popen("conntrack -L conntrack -p tcp --state ESTABLISHED --orig-port-dst "..p2.." --reply-port-dst "..p1.." -d "..remhost,"r")
  34                                 local rpl = rp:read("*l") or ""
  35                                 rp:close()
  36                                 local h=rpl:match(".-src%=([^ ]*) ")
  37                                 if h then
  38                                         local hn=socket.try(socket.dns.tohostname(h or ""))
  39                                         local rhn=hn:match("^([^.]*)"):sub(1,9)
  40                                         socket.try(v:setoption("linger", {on=true,timeout=5}))
  41                                         socket.try(v:send(p1.." , "..p2.." : USERID : UNIX : "..rhn.."\r\n"))
  42                                 end
  43                         end)() end
  44
  45                         for idx,tv in ipairs(ins) do
  46                                 if tv==v then
  47                                         v:close()
  48                                         table.remove(ins,idx)
  49                                 end
  50                         end
  51                 end
  52         end
  53 end