DSLAM

input = peripheral.wrap("bottom")
out = peripheral.wrap("top")

input.setListening(1, true)
input.setDefaultChannel(1)
out.open(1)

local split = function(inputstr, sep)
  if sep == nil then
    sep = "%s"
  end
  sep = tostring(sep)
  local t={}
  local i=1
  for str in string.gmatch(inputstr, "([^"..sep.."]*)"..sep.."?") do
    t[i] = str
    i = i+1
  end
  return t
end

if fs.exists("conf.cfg") then
  conf = fs.open("conf.cfg", "r")
  MyIP = conf.readAll()
  conf.close()
else
  input.send("REG_IP")
  print("Waiting for registration...")
  local _, _, _, _, msg = os.pullEvent("lan_message")
  MyIP = msg
  conf = fs.open("conf.cfg", "w")
  conf.writeLine(msg)
  conf.close()
end

term.clear()
print("DLSAM by O2 (0.1) / IP: " .. MyIP)
print("--------------------------------------")

while true do

  local income = {os.pullEvent()}

  if income[1] == "lan_message" then
    from = income[3]
    msg = income[5]

    cut = split(msg, ";")

    if cut[1] == MyIP then
      out.transmit(1, 1, cut[2])
      print("OUT > IN")
    end

  elseif income[1] == "modem_message" then
    from = income[3]
    msg = income[5]

    if msg == "REG_IP" then
      repeat
        lc = math.random(2,255)
        tip = "10.0.0." .. lc
        if fs.exists("LOCAL_ADRESS/" .. tip) then
          r = 0
        else
          r = 1
        end
      until r == 1
      nc = fs.open("LOCAL_ADRESS/" .. tip, "w")
      nc.writeLine(from)
      nc.close()

      out.transmit(from .. "/" .. tip)
      print("Registered PC " .. from .. " to " .. tip)

    else
      cut = split(msg, "*")
      if cut[1] == "10.0.0.1" then
        input.send(msg)
        print("IN > OUT")
      end
    end
  end
end