mihomo/component/ebpf/ebpf_linux.go
2023-11-03 21:58:21 +08:00

137 lines
3.8 KiB
Go

//go:build !android
package ebpf
import (
"fmt"
"net/netip"
"github.com/metacubex/mihomo/common/cmd"
"github.com/metacubex/mihomo/component/dialer"
"github.com/metacubex/mihomo/component/ebpf/redir"
"github.com/metacubex/mihomo/component/ebpf/tc"
C "github.com/metacubex/mihomo/constant"
"github.com/sagernet/netlink"
)
func GetAutoDetectInterface() (string, error) {
routes, err := netlink.RouteList(nil, netlink.FAMILY_V4)
if err != nil {
return "", err
}
for _, route := range routes {
if route.Dst == nil {
lk, err := netlink.LinkByIndex(route.LinkIndex)
if err != nil {
return "", err
}
if lk.Type() == "tuntap" {
continue
}
return lk.Attrs().Name, nil
}
}
return "", fmt.Errorf("interface not found")
}
// NewTcEBpfProgram new redirect to tun ebpf program
func NewTcEBpfProgram(ifaceNames []string, tunName string) (*TcEBpfProgram, error) {
tunIface, err := netlink.LinkByName(tunName)
if err != nil {
return nil, fmt.Errorf("lookup network iface %q: %w", tunName, err)
}
tunIndex := uint32(tunIface.Attrs().Index)
dialer.DefaultRoutingMark.Store(C.MihomoTrafficMark)
ifMark := uint32(dialer.DefaultRoutingMark.Load())
var pros []C.EBpf
for _, ifaceName := range ifaceNames {
iface, err := netlink.LinkByName(ifaceName)
if err != nil {
return nil, fmt.Errorf("lookup network iface %q: %w", ifaceName, err)
}
if iface.Attrs().OperState != netlink.OperUp {
return nil, fmt.Errorf("network iface %q is down", ifaceName)
}
attrs := iface.Attrs()
index := attrs.Index
tcPro := tc.NewEBpfTc(ifaceName, index, ifMark, tunIndex)
if err = tcPro.Start(); err != nil {
return nil, err
}
pros = append(pros, tcPro)
}
systemSetting(ifaceNames...)
return &TcEBpfProgram{pros: pros, rawNICs: ifaceNames}, nil
}
// NewRedirEBpfProgram new auto redirect ebpf program
func NewRedirEBpfProgram(ifaceNames []string, redirPort uint16, defaultRouteInterfaceName string) (*TcEBpfProgram, error) {
defaultRouteInterface, err := netlink.LinkByName(defaultRouteInterfaceName)
if err != nil {
return nil, fmt.Errorf("lookup network iface %q: %w", defaultRouteInterfaceName, err)
}
defaultRouteIndex := uint32(defaultRouteInterface.Attrs().Index)
var pros []C.EBpf
for _, ifaceName := range ifaceNames {
iface, err := netlink.LinkByName(ifaceName)
if err != nil {
return nil, fmt.Errorf("lookup network iface %q: %w", ifaceName, err)
}
attrs := iface.Attrs()
index := attrs.Index
addrs, err := netlink.AddrList(iface, netlink.FAMILY_V4)
if err != nil {
return nil, fmt.Errorf("lookup network iface %q address: %w", ifaceName, err)
}
if len(addrs) == 0 {
return nil, fmt.Errorf("network iface %q does not contain any ipv4 addresses", ifaceName)
}
address, _ := netip.AddrFromSlice(addrs[0].IP)
redirAddrPort := netip.AddrPortFrom(address, redirPort)
redirPro := redir.NewEBpfRedirect(ifaceName, index, 0, defaultRouteIndex, redirAddrPort)
if err = redirPro.Start(); err != nil {
return nil, err
}
pros = append(pros, redirPro)
}
systemSetting(ifaceNames...)
return &TcEBpfProgram{pros: pros, rawNICs: ifaceNames}, nil
}
func systemSetting(ifaceNames ...string) {
_, _ = cmd.ExecCmd("sysctl -w net.ipv4.ip_forward=1")
_, _ = cmd.ExecCmd("sysctl -w net.ipv4.conf.all.forwarding=1")
_, _ = cmd.ExecCmd("sysctl -w net.ipv4.conf.all.accept_local=1")
_, _ = cmd.ExecCmd("sysctl -w net.ipv4.conf.all.accept_redirects=1")
_, _ = cmd.ExecCmd("sysctl -w net.ipv4.conf.all.rp_filter=0")
for _, ifaceName := range ifaceNames {
_, _ = cmd.ExecCmd(fmt.Sprintf("sysctl -w net.ipv4.conf.%s.forwarding=1", ifaceName))
_, _ = cmd.ExecCmd(fmt.Sprintf("sysctl -w net.ipv4.conf.%s.accept_local=1", ifaceName))
_, _ = cmd.ExecCmd(fmt.Sprintf("sysctl -w net.ipv4.conf.%s.accept_redirects=1", ifaceName))
_, _ = cmd.ExecCmd(fmt.Sprintf("sysctl -w net.ipv4.conf.%s.rp_filter=0", ifaceName))
}
}