wireguard-go-awg2-lx/conn/features_linux.go
Leadaxe 0c0c10b5d3 docs(010): use rename-stable SPECS folder ref in fix comments
sing-box-lx is dropping type/status from SPEC folder names
(NNN-T-S-NAME → NNN-NAME), so the -B-C- tail goes stale. Point at the
new stable folder name SPECS/010-WG_ENDPOINT_GRO_SPLIT_BRAIN.
Comment-only, no behavior change.
2026-06-22 11:28:39 +03:00

52 lines
1.3 KiB
Go

/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
*/
package conn
import (
"net"
"runtime"
"golang.org/x/sys/unix"
)
const (
// TODO: upstream to x/sys/unix
socketOptionLevelUDP = 17
socketOptionUDPSegment = 103
socketOptionUDPGRO = 104
)
func supportsUDPOffload(conn *net.UDPConn) (txOffload, rxOffload bool) {
rc, err := conn.SyscallConn()
if err != nil {
return
}
err = rc.Control(func(fd uintptr) {
_, errSyscall := unix.GetsockoptInt(int(fd), unix.IPPROTO_UDP, socketOptionUDPSegment)
if errSyscall != nil {
return
}
txOffload = true
// lx(010): never advertise RX offload on android. runtime.GOOS=="android"
// (not "linux"), so the GRO receive dispatcher in bind_std.go (gated on
// GOOS=="linux") is dead there — a coalesced GRO super-packet would be read
// as one datagram and corrupt the WG transport stream, killing download.
// Confirmed on device (CPH2411/Android-15: rxOffload=true, dispatch=single).
// TX is left untouched. See SPECS/010-WG_ENDPOINT_GRO_SPLIT_BRAIN.
if runtime.GOOS == "android" {
return
}
opt, errSyscall := unix.GetsockoptInt(int(fd), unix.IPPROTO_UDP, socketOptionUDPGRO)
if errSyscall != nil {
return
}
rxOffload = opt == 1
})
if err != nil {
return false, false
}
return txOffload, rxOffload
}