luasocket/etc/forward.lua

66 lines
2.0 KiB
Lua

-- load our favourite library
local dispatch = require("dispatch")
local handler = dispatch.newhandler()
-- make sure the user knows how to invoke us
if #arg < 1 then
print("Usage")
print(" lua forward.lua <iport:ohost:oport> ...")
os.exit(1)
end
-- function to move data from one socket to the other
local function move(foo, bar)
local live
while 1 do
local data, error, partial = foo:receive(2048)
live = data or error == "timeout"
data = data or partial
local result, error = bar:send(data)
if not live or not result then
foo:close()
bar:close()
break
end
end
end
-- for each tunnel, start a new server
for i, v in ipairs(arg) do
-- capture forwarding parameters
local _, _, iport, ohost, oport = string.find(v, "([^:]+):([^:]+):([^:]+)")
assert(iport, "invalid arguments")
-- create our server socket
local server = assert(handler.tcp())
assert(server:setoption("reuseaddr", true))
assert(server:bind("*", iport))
assert(server:listen(32))
-- handler for the server object loops accepting new connections
handler:start(function()
while 1 do
local client = assert(server:accept())
assert(client:settimeout(0))
-- for each new connection, start a new client handler
handler:start(function()
-- handler tries to connect to peer
local peer = assert(handler.tcp())
assert(peer:settimeout(0))
assert(peer:connect(ohost, oport))
-- if sucessful, starts a new handler to send data from
-- client to peer
handler:start(function()
move(client, peer)
end)
-- afte starting new handler, enter in loop sending data from
-- peer to client
move(peer, client)
end)
end
end)
end
-- simply loop stepping the server
while 1 do
handler:step()
end