support ebpf

component/ebpf/redir/auto_redirect.go

@@ -0,0 +1,216 @@
+//go:build linux
+
+package redir
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"net"
+	"net/netip"
+	"os"
+	"path/filepath"
+
+	"github.com/cilium/ebpf"
+	"github.com/cilium/ebpf/rlimit"
+	"github.com/vishvananda/netlink"
+	"golang.org/x/sys/unix"
+
+	"github.com/Dreamacro/clash/component/ebpf/byteorder"
+	C "github.com/Dreamacro/clash/constant"
+	"github.com/Dreamacro/clash/transport/socks5"
+)
+
+//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -cc $BPF_CLANG -cflags $BPF_CFLAGS bpf ../bpf/redir.c
+
+const (
+	mapKey1 uint32 = 0
+	mapKey2 uint32 = 1
+	mapKey3 uint32 = 2
+)
+
+type EBpfRedirect struct {
+	objs         io.Closer
+	originMap    *ebpf.Map
+	qdisc        netlink.Qdisc
+	filter       netlink.Filter
+	filterEgress netlink.Filter
+
+	ifName    string
+	ifIndex   int
+	ifMark    uint32
+	rtIndex   uint32
+	redirIp   uint32
+	redirPort uint16
+
+	bpfPath string
+}
+
+func NewEBpfRedirect(ifName string, ifIndex int, ifMark uint32, routeIndex uint32, redirAddrPort netip.AddrPort) *EBpfRedirect {
+	return &EBpfRedirect{
+		ifName:    ifName,
+		ifIndex:   ifIndex,
+		ifMark:    ifMark,
+		rtIndex:   routeIndex,
+		redirIp:   binary.BigEndian.Uint32(redirAddrPort.Addr().AsSlice()),
+		redirPort: redirAddrPort.Port(),
+	}
+}
+
+func (e *EBpfRedirect) Start() error {
+	if err := rlimit.RemoveMemlock(); err != nil {
+		return fmt.Errorf("remove memory lock: %w", err)
+	}
+
+	e.bpfPath = filepath.Join(C.BpfFSPath, e.ifName)
+	if err := os.MkdirAll(e.bpfPath, os.ModePerm); err != nil {
+		return fmt.Errorf("failed to create bpf fs subpath: %w", err)
+	}
+
+	var objs bpfObjects
+	if err := loadBpfObjects(&objs, &ebpf.CollectionOptions{
+		Maps: ebpf.MapOptions{
+			PinPath: e.bpfPath,
+		},
+	}); err != nil {
+		e.Close()
+		return fmt.Errorf("loading objects: %w", err)
+	}
+
+	e.objs = &objs
+	e.originMap = objs.bpfMaps.PairOriginalDstMap
+
+	if err := objs.bpfMaps.RedirParamsMap.Update(mapKey1, e.rtIndex, ebpf.UpdateAny); err != nil {
+		e.Close()
+		return fmt.Errorf("storing objects: %w", err)
+	}
+
+	if err := objs.bpfMaps.RedirParamsMap.Update(mapKey2, e.redirIp, ebpf.UpdateAny); err != nil {
+		e.Close()
+		return fmt.Errorf("storing objects: %w", err)
+	}
+
+	if err := objs.bpfMaps.RedirParamsMap.Update(mapKey3, uint32(e.redirPort), ebpf.UpdateAny); err != nil {
+		e.Close()
+		return fmt.Errorf("storing objects: %w", err)
+	}
+
+	attrs := netlink.QdiscAttrs{
+		LinkIndex: e.ifIndex,
+		Handle:    netlink.MakeHandle(0xffff, 0),
+		Parent:    netlink.HANDLE_CLSACT,
+	}
+
+	qdisc := &netlink.GenericQdisc{
+		QdiscAttrs: attrs,
+		QdiscType:  "clsact",
+	}
+
+	e.qdisc = qdisc
+
+	if err := netlink.QdiscAdd(qdisc); err != nil {
+		if os.IsExist(err) {
+			_ = netlink.QdiscDel(qdisc)
+			err = netlink.QdiscAdd(qdisc)
+		}
+
+		if err != nil {
+			e.Close()
+			return fmt.Errorf("cannot add clsact qdisc: %w", err)
+		}
+	}
+
+	filterAttrs := netlink.FilterAttrs{
+		LinkIndex: e.ifIndex,
+		Parent:    netlink.HANDLE_MIN_INGRESS,
+		Handle:    netlink.MakeHandle(0, 1),
+		Protocol:  unix.ETH_P_IP,
+		Priority:  0,
+	}
+
+	filter := &netlink.BpfFilter{
+		FilterAttrs:  filterAttrs,
+		Fd:           objs.bpfPrograms.TcRedirIngressFunc.FD(),
+		Name:         "clash-redir-ingress-" + e.ifName,
+		DirectAction: true,
+	}
+
+	if err := netlink.FilterAdd(filter); err != nil {
+		e.Close()
+		return fmt.Errorf("cannot attach ebpf object to filter ingress: %w", err)
+	}
+
+	e.filter = filter
+
+	filterAttrsEgress := netlink.FilterAttrs{
+		LinkIndex: e.ifIndex,
+		Parent:    netlink.HANDLE_MIN_EGRESS,
+		Handle:    netlink.MakeHandle(0, 1),
+		Protocol:  unix.ETH_P_IP,
+		Priority:  0,
+	}
+
+	filterEgress := &netlink.BpfFilter{
+		FilterAttrs:  filterAttrsEgress,
+		Fd:           objs.bpfPrograms.TcRedirEgressFunc.FD(),
+		Name:         "clash-redir-egress-" + e.ifName,
+		DirectAction: true,
+	}
+
+	if err := netlink.FilterAdd(filterEgress); err != nil {
+		e.Close()
+		return fmt.Errorf("cannot attach ebpf object to filter egress: %w", err)
+	}
+
+	e.filterEgress = filterEgress
+
+	return nil
+}
+
+func (e *EBpfRedirect) Close() {
+	if e.filter != nil {
+		_ = netlink.FilterDel(e.filter)
+	}
+	if e.filterEgress != nil {
+		_ = netlink.FilterDel(e.filterEgress)
+	}
+	if e.qdisc != nil {
+		_ = netlink.QdiscDel(e.qdisc)
+	}
+	if e.objs != nil {
+		_ = e.objs.Close()
+	}
+	_ = os.Remove(filepath.Join(e.bpfPath, "redir_params_map"))
+	_ = os.Remove(filepath.Join(e.bpfPath, "pair_original_dst_map"))
+}
+
+func (e *EBpfRedirect) Lookup(srcAddrPort netip.AddrPort) (socks5.Addr, error) {
+	rAddr := srcAddrPort.Addr().Unmap()
+	if rAddr.Is6() {
+		return nil, fmt.Errorf("remote address is ipv6")
+	}
+
+	srcIp := binary.BigEndian.Uint32(rAddr.AsSlice())
+	scrPort := srcAddrPort.Port()
+
+	key := bpfRedirInfo{
+		Sip:   byteorder.HostToNetwork32(srcIp),
+		Sport: byteorder.HostToNetwork16(scrPort),
+		Dip:   byteorder.HostToNetwork32(e.redirIp),
+		Dport: byteorder.HostToNetwork16(e.redirPort),
+	}
+
+	origin := bpfOriginInfo{}
+
+	err := e.originMap.Lookup(key, &origin)
+	if err != nil {
+		return nil, err
+	}
+
+	addr := make([]byte, net.IPv4len+3)
+	addr[0] = socks5.AtypIPv4
+
+	binary.BigEndian.PutUint32(addr[1:1+net.IPv4len], byteorder.NetworkToHost32(origin.Ip))               // big end
+	binary.BigEndian.PutUint16(addr[1+net.IPv4len:3+net.IPv4len], byteorder.NetworkToHost16(origin.Port)) // big end
+	return addr, nil
+}

component/ebpf/redir/bpf_bpfeb.go

@@ -0,0 +1,138 @@
+// Code generated by bpf2go; DO NOT EDIT.
+//go:build arm64be || armbe || mips || mips64 || mips64p32 || ppc64 || s390 || s390x || sparc || sparc64
+// +build arm64be armbe mips mips64 mips64p32 ppc64 s390 s390x sparc sparc64
+
+package redir
+
+import (
+	"bytes"
+	_ "embed"
+	"fmt"
+	"io"
+
+	"github.com/cilium/ebpf"
+)
+
+type bpfOriginInfo struct {
+	Ip   uint32
+	Port uint16
+	Pad  uint16
+}
+
+type bpfRedirInfo struct {
+	Sip   uint32
+	Dip   uint32
+	Sport uint16
+	Dport uint16
+}
+
+// loadBpf returns the embedded CollectionSpec for bpf.
+func loadBpf() (*ebpf.CollectionSpec, error) {
+	reader := bytes.NewReader(_BpfBytes)
+	spec, err := ebpf.LoadCollectionSpecFromReader(reader)
+	if err != nil {
+		return nil, fmt.Errorf("can't load bpf: %w", err)
+	}
+
+	return spec, err
+}
+
+// loadBpfObjects loads bpf and converts it into a struct.
+//
+// The following types are suitable as obj argument:
+//
+//     *bpfObjects
+//     *bpfPrograms
+//     *bpfMaps
+//
+// See ebpf.CollectionSpec.LoadAndAssign documentation for details.
+func loadBpfObjects(obj interface{}, opts *ebpf.CollectionOptions) error {
+	spec, err := loadBpf()
+	if err != nil {
+		return err
+	}
+
+	return spec.LoadAndAssign(obj, opts)
+}
+
+// bpfSpecs contains maps and programs before they are loaded into the kernel.
+//
+// It can be passed ebpf.CollectionSpec.Assign.
+type bpfSpecs struct {
+	bpfProgramSpecs
+	bpfMapSpecs
+}
+
+// bpfSpecs contains programs before they are loaded into the kernel.
+//
+// It can be passed ebpf.CollectionSpec.Assign.
+type bpfProgramSpecs struct {
+	TcRedirEgressFunc  *ebpf.ProgramSpec `ebpf:"tc_redir_egress_func"`
+	TcRedirIngressFunc *ebpf.ProgramSpec `ebpf:"tc_redir_ingress_func"`
+}
+
+// bpfMapSpecs contains maps before they are loaded into the kernel.
+//
+// It can be passed ebpf.CollectionSpec.Assign.
+type bpfMapSpecs struct {
+	PairOriginalDstMap *ebpf.MapSpec `ebpf:"pair_original_dst_map"`
+	RedirParamsMap     *ebpf.MapSpec `ebpf:"redir_params_map"`
+}
+
+// bpfObjects contains all objects after they have been loaded into the kernel.
+//
+// It can be passed to loadBpfObjects or ebpf.CollectionSpec.LoadAndAssign.
+type bpfObjects struct {
+	bpfPrograms
+	bpfMaps
+}
+
+func (o *bpfObjects) Close() error {
+	return _BpfClose(
+		&o.bpfPrograms,
+		&o.bpfMaps,
+	)
+}
+
+// bpfMaps contains all maps after they have been loaded into the kernel.
+//
+// It can be passed to loadBpfObjects or ebpf.CollectionSpec.LoadAndAssign.
+type bpfMaps struct {
+	PairOriginalDstMap *ebpf.Map `ebpf:"pair_original_dst_map"`
+	RedirParamsMap     *ebpf.Map `ebpf:"redir_params_map"`
+}
+
+func (m *bpfMaps) Close() error {
+	return _BpfClose(
+		m.PairOriginalDstMap,
+		m.RedirParamsMap,
+	)
+}
+
+// bpfPrograms contains all programs after they have been loaded into the kernel.
+//
+// It can be passed to loadBpfObjects or ebpf.CollectionSpec.LoadAndAssign.
+type bpfPrograms struct {
+	TcRedirEgressFunc  *ebpf.Program `ebpf:"tc_redir_egress_func"`
+	TcRedirIngressFunc *ebpf.Program `ebpf:"tc_redir_ingress_func"`
+}
+
+func (p *bpfPrograms) Close() error {
+	return _BpfClose(
+		p.TcRedirEgressFunc,
+		p.TcRedirIngressFunc,
+	)
+}
+
+func _BpfClose(closers ...io.Closer) error {
+	for _, closer := range closers {
+		if err := closer.Close(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Do not access this directly.
+//go:embed bpf_bpfeb.o
+var _BpfBytes []byte

component/ebpf/redir/bpf_bpfel.go

@@ -0,0 +1,138 @@
+// Code generated by bpf2go; DO NOT EDIT.
+//go:build 386 || amd64 || amd64p32 || arm || arm64 || mips64le || mips64p32le || mipsle || ppc64le || riscv64
+// +build 386 amd64 amd64p32 arm arm64 mips64le mips64p32le mipsle ppc64le riscv64
+
+package redir
+
+import (
+	"bytes"
+	_ "embed"
+	"fmt"
+	"io"
+
+	"github.com/cilium/ebpf"
+)
+
+type bpfOriginInfo struct {
+	Ip   uint32
+	Port uint16
+	Pad  uint16
+}
+
+type bpfRedirInfo struct {
+	Sip   uint32
+	Dip   uint32
+	Sport uint16
+	Dport uint16
+}
+
+// loadBpf returns the embedded CollectionSpec for bpf.
+func loadBpf() (*ebpf.CollectionSpec, error) {
+	reader := bytes.NewReader(_BpfBytes)
+	spec, err := ebpf.LoadCollectionSpecFromReader(reader)
+	if err != nil {
+		return nil, fmt.Errorf("can't load bpf: %w", err)
+	}
+
+	return spec, err
+}
+
+// loadBpfObjects loads bpf and converts it into a struct.
+//
+// The following types are suitable as obj argument:
+//
+//     *bpfObjects
+//     *bpfPrograms
+//     *bpfMaps
+//
+// See ebpf.CollectionSpec.LoadAndAssign documentation for details.
+func loadBpfObjects(obj interface{}, opts *ebpf.CollectionOptions) error {
+	spec, err := loadBpf()
+	if err != nil {
+		return err
+	}
+
+	return spec.LoadAndAssign(obj, opts)
+}
+
+// bpfSpecs contains maps and programs before they are loaded into the kernel.
+//
+// It can be passed ebpf.CollectionSpec.Assign.
+type bpfSpecs struct {
+	bpfProgramSpecs
+	bpfMapSpecs
+}
+
+// bpfSpecs contains programs before they are loaded into the kernel.
+//
+// It can be passed ebpf.CollectionSpec.Assign.
+type bpfProgramSpecs struct {
+	TcRedirEgressFunc  *ebpf.ProgramSpec `ebpf:"tc_redir_egress_func"`
+	TcRedirIngressFunc *ebpf.ProgramSpec `ebpf:"tc_redir_ingress_func"`
+}
+
+// bpfMapSpecs contains maps before they are loaded into the kernel.
+//
+// It can be passed ebpf.CollectionSpec.Assign.
+type bpfMapSpecs struct {
+	PairOriginalDstMap *ebpf.MapSpec `ebpf:"pair_original_dst_map"`
+	RedirParamsMap     *ebpf.MapSpec `ebpf:"redir_params_map"`
+}
+
+// bpfObjects contains all objects after they have been loaded into the kernel.
+//
+// It can be passed to loadBpfObjects or ebpf.CollectionSpec.LoadAndAssign.
+type bpfObjects struct {
+	bpfPrograms
+	bpfMaps
+}
+
+func (o *bpfObjects) Close() error {
+	return _BpfClose(
+		&o.bpfPrograms,
+		&o.bpfMaps,
+	)
+}
+
+// bpfMaps contains all maps after they have been loaded into the kernel.
+//
+// It can be passed to loadBpfObjects or ebpf.CollectionSpec.LoadAndAssign.
+type bpfMaps struct {
+	PairOriginalDstMap *ebpf.Map `ebpf:"pair_original_dst_map"`
+	RedirParamsMap     *ebpf.Map `ebpf:"redir_params_map"`
+}
+
+func (m *bpfMaps) Close() error {
+	return _BpfClose(
+		m.PairOriginalDstMap,
+		m.RedirParamsMap,
+	)
+}
+
+// bpfPrograms contains all programs after they have been loaded into the kernel.
+//
+// It can be passed to loadBpfObjects or ebpf.CollectionSpec.LoadAndAssign.
+type bpfPrograms struct {
+	TcRedirEgressFunc  *ebpf.Program `ebpf:"tc_redir_egress_func"`
+	TcRedirIngressFunc *ebpf.Program `ebpf:"tc_redir_ingress_func"`
+}
+
+func (p *bpfPrograms) Close() error {
+	return _BpfClose(
+		p.TcRedirEgressFunc,
+		p.TcRedirIngressFunc,
+	)
+}
+
+func _BpfClose(closers ...io.Closer) error {
+	for _, closer := range closers {
+		if err := closer.Close(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Do not access this directly.
+//go:embed bpf_bpfel.o
+var _BpfBytes []byte