--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/etc/forward.lua	Tue Aug 26 18:40:01 2008 -0700
@@ -0,0 +1,65 @@
+-- load our favourite library
+local dispatch = require("dispatch")
+local handler = dispatch.newhandler()
+
+-- make sure the user knows how to invoke us
+if table.getn(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