func newSshClient(
sshServer *sshServer, tunnelProtocol string, geoIPData GeoIPData, trafficRules TrafficRules) *sshClient {
return &sshClient{
sshServer: sshServer,
tunnelProtocol: tunnelProtocol,
geoIPData: geoIPData,
trafficRules: trafficRules,
tcpTrafficState: &trafficState{},
udpTrafficState: &trafficState{},
channelHandlerWaitGroup: new(sync.WaitGroup),
tcpPortForwardLRU: psiphon.NewLRUConns(),
stopBroadcast: make(chan struct{}),
}
}
// handleUDPChannel implements UDP port forwarding. A single UDP
// SSH channel follows the udpgw protocol, which multiplexes many
// UDP port forwards.
//
// The udpgw protocol and original server implementation:
// Copyright (c) 2009, Ambroz Bizjak <*****@*****.**>
// https://github.com/ambrop72/badvpn
//
func (sshClient *sshClient) handleUDPChannel(newChannel ssh.NewChannel) {
// Accept this channel immediately. This channel will replace any
// previously existing UDP channel for this client.
sshChannel, requests, err := newChannel.Accept()
if err != nil {
log.WithContextFields(LogFields{"error": err}).Warning("accept new channel failed")
return
}
go ssh.DiscardRequests(requests)
defer sshChannel.Close()
sshClient.setUDPChannel(sshChannel)
multiplexer := &udpPortForwardMultiplexer{
sshClient: sshClient,
sshChannel: sshChannel,
portForwards: make(map[uint16]*udpPortForward),
portForwardLRU: psiphon.NewLRUConns(),
relayWaitGroup: new(sync.WaitGroup),
}
multiplexer.run()
}