sing-tun/tun_linux_flags.go
2024-11-23 12:58:52 +08:00

90 lines
2.1 KiB
Go

//go:build linux
package tun
import (
"os"
"syscall"
"unsafe"
E "github.com/sagernet/sing/common/exceptions"
"golang.org/x/sys/unix"
)
const (
// TODO: support TSO with ECN bits
tunTCPOffloads = unix.TUN_F_CSUM | unix.TUN_F_TSO4 | unix.TUN_F_TSO6
tunUDPOffloads = unix.TUN_F_USO4 | unix.TUN_F_USO6
)
func checkVNETHDREnabled(fd int, name string) (bool, error) {
ifr, err := unix.NewIfreq(name)
if err != nil {
return false, err
}
err = unix.IoctlIfreq(fd, unix.TUNGETIFF, ifr)
if err != nil {
return false, os.NewSyscallError("TUNGETIFF", err)
}
return ifr.Uint16()&unix.IFF_VNET_HDR != 0, nil
}
func setTCPOffload(fd int) error {
err := unix.IoctlSetInt(fd, unix.TUNSETOFFLOAD, tunTCPOffloads)
if err != nil {
return E.Cause(os.NewSyscallError("TUNSETOFFLOAD", err), "enable offload")
}
return nil
}
func setUDPOffload(fd int) error {
return unix.IoctlSetInt(fd, unix.TUNSETOFFLOAD, tunTCPOffloads|tunUDPOffloads)
}
type ifreqData struct {
ifrName [unix.IFNAMSIZ]byte
ifrData uintptr
}
type ethtoolValue struct {
cmd uint32
data uint32
}
//go:linkname ioctlPtr golang.org/x/sys/unix.ioctlPtr
func ioctlPtr(fd int, req uint, arg unsafe.Pointer) (err error)
func checkChecksumOffload(name string, cmd uint32) (bool, error) {
fd, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, unix.IPPROTO_IP)
if err != nil {
return false, err
}
defer syscall.Close(fd)
ifr := ifreqData{}
copy(ifr.ifrName[:], name)
data := ethtoolValue{cmd: cmd}
ifr.ifrData = uintptr(unsafe.Pointer(&data))
err = ioctlPtr(fd, unix.SIOCETHTOOL, unsafe.Pointer(&ifr))
if err != nil {
return false, os.NewSyscallError("SIOCETHTOOL ETHTOOL_GTXCSUM", err)
}
return data.data == 0, nil
}
func setChecksumOffload(name string, cmd uint32) error {
fd, err := unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, unix.IPPROTO_IP)
if err != nil {
return err
}
defer syscall.Close(fd)
ifr := ifreqData{}
copy(ifr.ifrName[:], name)
data := ethtoolValue{cmd: cmd, data: 0}
ifr.ifrData = uintptr(unsafe.Pointer(&data))
err = ioctlPtr(fd, unix.SIOCETHTOOL, unsafe.Pointer(&ifr))
if err != nil {
return os.NewSyscallError("SIOCETHTOOL ETHTOOL_STXCSUM", err)
}
return nil
}