Disable Nagle on the underlying TCP socket for relay+ws, relay+wss, and
relay+tls listeners/dialers. Small latency-sensitive datagrams (e.g.
WireGuard UDP over a relay tunnel) were being coalesced by Nagle until a
peer ACK returned, adding up to one RTT per datagram and inflating
round-trip latency (go-gost/gost#858). wstunnel sets TCP_NODELAY on its
tunnel socket by default and keeps latency flat; gost did not.
Add ApplyNoDelay helper and WrapNoDelayListener (mirrors ApplyKeepalive),
applied on the raw *net.TCPConn before the proxyproto/tls wrapper chain.
Add configurable TCP keepalive (keepalive, keepalive.idle,
keepalive.interval, keepalive.count) to all TCP-based transport types:
tls, mtls, mtcp, ws/wss, mws/mwss, http2, ssh, sshd listeners and
tls, mtls, mtcp, ws/wss, mws/mwss, ssh, sshd dialers.
For types that already use "keepalive" for an app-level protocol
(grpc listener/dialer, ws/mws dialers, ssh/sshd dialers), the TCP
keepalive parameters are exposed under the tcp.keepalive.* prefix to
avoid ambiguity.
Also extract shared helpers into internal/net/keepalive.go:
- WrapKeepaliveListener: applies KeepAliveConfig on every accepted TCPConn
- ApplyKeepalive: applies KeepAliveConfig to a single TCPConn
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
ginuerzh