Jigsaw-Code / outline-go-tun2socks

Apache License 2.0
231 stars 94 forks source link

Remove or extend UDP listening timeout #109

Open fortuna opened 1 year ago

fortuna commented 1 year ago

If a read hits the timeout, we stop listening for packets: https://github.com/Jigsaw-Code/outline-go-tun2socks/blob/ab0408a6d301b3a55105b94255c1d436c4f6480d/shadowsocks/udp.go#L52-L56

I wonder if this is causing issues with apps that use UDP, specially in extreme conditions.

The default timeout is 30 seconds: https://github.com/Jigsaw-Code/outline-go-tun2socks/blob/2f14928f97f3730e8c5c387003284db8fc12b445/outline/tunnel.go#L84

It's not clear to me that we need the timeout. Tun2socks stack will supposedly call udpHandler.Close() when the app socket is closed.

My suggestion is to remove the timeout. At least make is longer, like the 5 minutes we use on the server: https://github.com/Jigsaw-Code/outline-ss-server/blob/8269318bb6268f9de5b289c31a59da7617520ce8/server.go#L50-L51

bemasc commented 1 year ago

Tun2socks stack will supposedly call udpHandler.Close() when the app socket is closed.

No, tun2socks has no way to know whether the app socket has been closed. It only has access to the "tun device" as an io.ReadWriteCloser, with IP packets flowing in and out.