//go:build linux package dialer import ( "context" "net" "net/netip" "syscall" ) func bindMarkToDialer(mark int, dialer *net.Dialer, _ string, _ netip.Addr) { addControlToDialer(dialer, bindMarkToControl(mark)) } func bindMarkToListenConfig(mark int, lc *net.ListenConfig, _, _ string) { addControlToListenConfig(lc, bindMarkToControl(mark)) } func bindMarkToControl(mark int) controlFn { return func(ctx context.Context, network, address string, c syscall.RawConn) (err error) { addrPort, err := netip.ParseAddrPort(address) if err == nil && !addrPort.Addr().IsGlobalUnicast() { return } var innerErr error err = c.Control(func(fd uintptr) { innerErr = syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_MARK, mark) }) if innerErr != nil { err = innerErr } return } }