Firewall

realid = 1

function spoof(nID)
local getID = os.getComputerID -- Backing up the old function
os.getComputerID = function(nID) -- Overriding it
    return nID or getID() -- Returning the fake id or the regular computer ID
end
end

function unspoof()
print("end spoof")
  spoof(5)
end
--firewall start
rednet.open("top")
rednet.open("back")
print("1")
while true do
rednet.open("top")
rednet.open("back")
var1, var2, var3 = rednet.receive()
print("id = "..tostring(var1))
print("msg = "..tostring(var2))
print("distance = "..tostring(var3))
print("2")
if var1 == 2  then
rednet.close("top")
rednet.open("back")
print("4")
spoof(var1)
print("5")
rednet.send(3, var2)
print("6")
elseif var1 == 3 then
rednet.close("back")
rednet.open("top")
print("7")
print("8")
spoof(var1)
print("9")
rednet.send(2, var2)
print("10")
else
rednet.send(var1, "deny")
print("11")
end
end