The SOCKS5 handler recorder only tracked TCP traffic metrics. UDP
associations (CmdUdp) overwrote TCP byte counts with UDP counts, and
UDP tunnels (CmdUDPTun) recorded zero bytes.
Changes:
- udp.go: change UDP stats assignment (=) to accumulation (+=) so the
TCP control connection bytes tracked by Handle() are preserved.
- udp_tun.go: add xstats.Stats{} wrapper around the PacketConn with
deferred accumulation into HandlerRecorderObject, mirroring the
handleUDP pattern.
ginuerzh