sing-tun/tun_linux.go
2025-03-19 20:37:03 +08:00

1078 lines
26 KiB
Go

package tun
import (
"errors"
"fmt"
"math/rand"
"net"
"net/netip"
"os"
"os/exec"
"runtime"
"sync"
"syscall"
"unsafe"
"github.com/sagernet/netlink"
"github.com/sagernet/sing-tun/internal/gtcpip/checksum"
"github.com/sagernet/sing-tun/internal/gtcpip/header"
"github.com/sagernet/sing/common"
"github.com/sagernet/sing/common/buf"
"github.com/sagernet/sing/common/bufio"
"github.com/sagernet/sing/common/control"
E "github.com/sagernet/sing/common/exceptions"
N "github.com/sagernet/sing/common/network"
"github.com/sagernet/sing/common/rw"
"github.com/sagernet/sing/common/shell"
"github.com/sagernet/sing/common/x/list"
"golang.org/x/sys/unix"
)
var _ LinuxTUN = (*NativeTun)(nil)
type NativeTun struct {
tunFd int
tunFile *os.File
tunWriter N.VectorisedWriter
interfaceCallback *list.Element[DefaultInterfaceUpdateCallback]
options Options
ruleIndex6 []int
readAccess sync.Mutex
writeAccess sync.Mutex
vnetHdr bool
writeBuffer []byte
gsoToWrite []int
tcpGROTable *tcpGROTable
udpGroAccess sync.Mutex
udpGROTable *udpGROTable
gro groDisablementFlags
txChecksumOffload bool
}
func New(options Options) (Tun, error) {
var nativeTun *NativeTun
if options.FileDescriptor == 0 {
tunFd, err := open(options.Name, options.GSO)
if err != nil {
return nil, err
}
tunLink, err := netlink.LinkByName(options.Name)
if err != nil {
return nil, E.Errors(err, unix.Close(tunFd))
}
nativeTun = &NativeTun{
tunFd: tunFd,
tunFile: os.NewFile(uintptr(tunFd), "tun"),
options: options,
}
err = nativeTun.configure(tunLink)
if err != nil {
return nil, E.Errors(err, unix.Close(tunFd))
}
} else {
nativeTun = &NativeTun{
tunFd: options.FileDescriptor,
tunFile: os.NewFile(uintptr(options.FileDescriptor), "tun"),
options: options,
}
}
var ok bool
nativeTun.tunWriter, ok = bufio.CreateVectorisedWriter(nativeTun.tunFile)
if !ok {
panic("create vectorised writer")
}
return nativeTun, nil
}
var controlPath string
func init() {
const defaultTunPath = "/dev/net/tun"
const androidTunPath = "/dev/tun"
if rw.IsFile(androidTunPath) {
controlPath = androidTunPath
} else {
controlPath = defaultTunPath
}
}
func open(name string, vnetHdr bool) (int, error) {
fd, err := unix.Open(controlPath, unix.O_RDWR, 0)
if err != nil {
return -1, err
}
ifr, err := unix.NewIfreq(name)
if err != nil {
unix.Close(fd)
return 0, err
}
flags := unix.IFF_TUN | unix.IFF_NO_PI
if vnetHdr {
flags |= unix.IFF_VNET_HDR
}
ifr.SetUint16(uint16(flags))
err = unix.IoctlIfreq(fd, unix.TUNSETIFF, ifr)
if err != nil {
unix.Close(fd)
return 0, err
}
err = unix.SetNonblock(fd, true)
if err != nil {
unix.Close(fd)
return 0, err
}
return fd, nil
}
func (t *NativeTun) configure(tunLink netlink.Link) error {
err := netlink.LinkSetMTU(tunLink, int(t.options.MTU))
if errors.Is(err, unix.EPERM) {
return nil
} else if err != nil {
return err
}
if len(t.options.Inet4Address) > 0 {
for _, address := range t.options.Inet4Address {
addr4, _ := netlink.ParseAddr(address.String())
err = netlink.AddrAdd(tunLink, addr4)
if err != nil {
return err
}
}
}
if len(t.options.Inet6Address) > 0 {
for _, address := range t.options.Inet6Address {
addr6, _ := netlink.ParseAddr(address.String())
err = netlink.AddrAdd(tunLink, addr6)
if err != nil {
return err
}
}
}
if t.options.GSO {
err = t.enableGSO()
if err != nil {
t.options.Logger.Warn(err)
}
}
var rxChecksumOffload bool
rxChecksumOffload, err = checkChecksumOffload(t.options.Name, unix.ETHTOOL_GRXCSUM)
if err == nil && !rxChecksumOffload {
_ = setChecksumOffload(t.options.Name, unix.ETHTOOL_SRXCSUM)
}
if t.options._TXChecksumOffload {
var txChecksumOffload bool
txChecksumOffload, err = checkChecksumOffload(t.options.Name, unix.ETHTOOL_GTXCSUM)
if err != nil {
return err
}
if !txChecksumOffload {
err = setChecksumOffload(t.options.Name, unix.ETHTOOL_STXCSUM)
if err != nil {
return err
}
}
t.txChecksumOffload = true
}
return nil
}
func (t *NativeTun) enableGSO() error {
vnetHdrEnabled, err := checkVNETHDREnabled(t.tunFd, t.options.Name)
if err != nil {
return E.Cause(err, "enable offload: check IFF_VNET_HDR enabled")
}
if !vnetHdrEnabled {
return E.Cause(err, "enable offload: IFF_VNET_HDR not enabled")
}
err = setTCPOffload(t.tunFd)
if err != nil {
return E.Cause(err, "enable TCP offload")
}
t.vnetHdr = true
t.writeBuffer = make([]byte, virtioNetHdrLen+int(gsoMaxSize))
t.tcpGROTable = newTCPGROTable()
t.udpGROTable = newUDPGROTable()
err = setUDPOffload(t.tunFd)
if err != nil {
t.gro.disableUDPGRO()
}
return nil
}
func (t *NativeTun) probeTCPGRO() error {
ipPort := netip.AddrPortFrom(t.options.Inet4Address[0].Addr(), 0)
fingerprint := []byte("sing-tun-probe-tun-gro")
segmentSize := len(fingerprint)
iphLen := 20
tcphLen := 20
totalLen := iphLen + tcphLen + segmentSize
bufs := make([][]byte, 2)
for i := range bufs {
bufs[i] = make([]byte, virtioNetHdrLen+totalLen, virtioNetHdrLen+(totalLen*2))
ipv4H := header.IPv4(bufs[i][virtioNetHdrLen:])
ipv4H.Encode(&header.IPv4Fields{
SrcAddr: ipPort.Addr(),
DstAddr: ipPort.Addr(),
Protocol: unix.IPPROTO_TCP,
// Use a zero value TTL as best effort means to reduce chance of
// probe packet leaking further than it needs to.
TTL: 0,
TotalLength: uint16(totalLen),
})
tcpH := header.TCP(bufs[i][virtioNetHdrLen+iphLen:])
tcpH.Encode(&header.TCPFields{
SrcPort: ipPort.Port(),
DstPort: ipPort.Port(),
SeqNum: 1 + uint32(i*segmentSize),
AckNum: 1,
DataOffset: 20,
Flags: header.TCPFlagAck,
WindowSize: 3000,
})
copy(bufs[i][virtioNetHdrLen+iphLen+tcphLen:], fingerprint)
ipv4H.SetChecksum(^ipv4H.CalculateChecksum())
pseudoCsum := header.PseudoHeaderChecksum(unix.IPPROTO_TCP, ipv4H.SourceAddressSlice(), ipv4H.DestinationAddressSlice(), uint16(tcphLen+segmentSize))
pseudoCsum = checksum.Checksum(bufs[i][virtioNetHdrLen+iphLen+tcphLen:], pseudoCsum)
tcpH.SetChecksum(^tcpH.CalculateChecksum(pseudoCsum))
}
_, err := t.BatchWrite(bufs, virtioNetHdrLen)
return err
}
func (t *NativeTun) Name() (string, error) {
var ifr [unix.IFNAMSIZ + 64]byte
_, _, errno := unix.Syscall(
unix.SYS_IOCTL,
uintptr(t.tunFd),
uintptr(unix.TUNGETIFF),
uintptr(unsafe.Pointer(&ifr[0])),
)
if errno != 0 {
return "", os.NewSyscallError("ioctl TUNGETIFF", errno)
}
return unix.ByteSliceToString(ifr[:]), nil
}
func (t *NativeTun) Start() error {
if t.options.FileDescriptor != 0 {
return nil
}
tunLink, err := netlink.LinkByName(t.options.Name)
if err != nil {
return err
}
err = netlink.LinkSetUp(tunLink)
if err != nil {
return err
}
if t.vnetHdr && len(t.options.Inet4Address) > 0 {
err = t.probeTCPGRO()
if err != nil {
t.gro.disableTCPGRO()
t.gro.disableUDPGRO()
t.options.Logger.Warn(E.Cause(err, "disabled TUN TCP & UDP GRO due to GRO probe error"))
}
}
if t.options.IPRoute2TableIndex == 0 {
for {
t.options.IPRoute2TableIndex = int(rand.Uint32())
routeList, fErr := netlink.RouteListFiltered(netlink.FAMILY_ALL, &netlink.Route{Table: t.options.IPRoute2TableIndex}, netlink.RT_FILTER_TABLE)
if len(routeList) == 0 || fErr != nil {
break
}
}
}
err = t.setRoute(tunLink)
if err != nil {
_ = t.unsetRoute0(tunLink)
return err
}
err = t.unsetRules()
if err != nil {
return E.Cause(err, "cleanup rules")
}
err = t.setRules()
if err != nil {
_ = t.unsetRules()
return err
}
t.setSearchDomainForSystemdResolved()
if t.options.AutoRoute && runtime.GOOS == "android" {
t.interfaceCallback = t.options.InterfaceMonitor.RegisterCallback(t.routeUpdate)
}
return nil
}
func (t *NativeTun) Close() error {
if t.interfaceCallback != nil {
t.options.InterfaceMonitor.UnregisterCallback(t.interfaceCallback)
}
return E.Errors(t.unsetRoute(), t.unsetRules(), common.Close(common.PtrOrNil(t.tunFile)))
}
func (t *NativeTun) Read(p []byte) (n int, err error) {
if t.vnetHdr {
n, err = t.tunFile.Read(t.writeBuffer)
if err != nil {
if errors.Is(err, syscall.EBADFD) {
err = os.ErrClosed
}
return
}
var sizes [1]int
n, err = handleVirtioRead(t.writeBuffer[:n], [][]byte{p}, sizes[:], 0)
if err != nil {
return
}
if n == 0 {
return
}
n = sizes[0]
return
} else {
return t.tunFile.Read(p)
}
}
// handleVirtioRead splits in into bufs, leaving offset bytes at the front of
// each buffer. It mutates sizes to reflect the size of each element of bufs,
// and returns the number of packets read.
func handleVirtioRead(in []byte, bufs [][]byte, sizes []int, offset int) (int, error) {
var hdr virtioNetHdr
err := hdr.decode(in)
if err != nil {
return 0, err
}
in = in[virtioNetHdrLen:]
options, err := hdr.toGSOOptions()
if err != nil {
return 0, err
}
// Don't trust HdrLen from the kernel as it can be equal to the length
// of the entire first packet when the kernel is handling it as part of a
// FORWARD path. Instead, parse the transport header length and add it onto
// CsumStart, which is synonymous for IP header length.
if options.GSOType == GSOUDPL4 {
options.HdrLen = options.CsumStart + 8
} else if options.GSOType != GSONone {
if len(in) <= int(options.CsumStart+12) {
return 0, errors.New("packet is too short")
}
tcpHLen := uint16(in[options.CsumStart+12] >> 4 * 4)
if tcpHLen < 20 || tcpHLen > 60 {
// A TCP header must be between 20 and 60 bytes in length.
return 0, fmt.Errorf("tcp header len is invalid: %d", tcpHLen)
}
options.HdrLen = options.CsumStart + tcpHLen
}
return GSOSplit(in, options, bufs, sizes, offset)
}
func (t *NativeTun) Write(p []byte) (n int, err error) {
if t.vnetHdr {
buffer := buf.Get(virtioNetHdrLen + len(p))
copy(buffer[virtioNetHdrLen:], p)
_, err = t.BatchWrite([][]byte{buffer}, virtioNetHdrLen)
buf.Put(buffer)
if err != nil {
return
}
n = len(p)
return
}
return t.tunFile.Write(p)
}
func (t *NativeTun) WriteVectorised(buffers []*buf.Buffer) error {
if t.vnetHdr {
n := buf.LenMulti(buffers)
buffer := buf.NewSize(virtioNetHdrLen + n)
buffer.Truncate(virtioNetHdrLen)
buf.CopyMulti(buffer.Extend(n), buffers)
_, err := t.tunFile.Write(buffer.Bytes())
buffer.Release()
return err
} else {
return t.tunWriter.WriteVectorised(buffers)
}
}
func (t *NativeTun) FrontHeadroom() int {
if t.vnetHdr {
return virtioNetHdrLen
}
return 0
}
func (t *NativeTun) BatchSize() int {
if !t.vnetHdr {
return 1
}
/* // Not works on some devices: https://github.com/SagerNet/sing-box/issues/1605
batchSize := int(gsoMaxSize/t.options.MTU) * 2
if batchSize > idealBatchSize {
batchSize = idealBatchSize
}
return batchSize*/
return idealBatchSize
}
func (t *NativeTun) BatchRead(buffers [][]byte, offset int, readN []int) (n int, err error) {
t.readAccess.Lock()
defer t.readAccess.Unlock()
n, err = t.tunFile.Read(t.writeBuffer)
if err != nil {
return
}
return handleVirtioRead(t.writeBuffer[:n], buffers, readN, offset)
}
func (t *NativeTun) BatchWrite(buffers [][]byte, offset int) (int, error) {
t.writeAccess.Lock()
defer func() {
t.tcpGROTable.reset()
t.udpGROTable.reset()
t.writeAccess.Unlock()
}()
var (
errs error
total int
)
t.gsoToWrite = t.gsoToWrite[:0]
if t.vnetHdr {
err := handleGRO(buffers, offset, t.tcpGROTable, t.udpGROTable, t.gro, &t.gsoToWrite)
if err != nil {
return 0, err
}
offset -= virtioNetHdrLen
} else {
for i := range buffers {
t.gsoToWrite = append(t.gsoToWrite, i)
}
}
for _, toWrite := range t.gsoToWrite {
n, err := t.tunFile.Write(buffers[toWrite][offset:])
if errors.Is(err, syscall.EBADFD) {
return total, os.ErrClosed
}
if err != nil {
errs = errors.Join(errs, err)
} else {
total += n
}
}
return total, errs
}
func (t *NativeTun) TXChecksumOffload() bool {
return t.txChecksumOffload
}
func prefixToIPNet(prefix netip.Prefix) *net.IPNet {
return &net.IPNet{
IP: prefix.Addr().AsSlice(),
Mask: net.CIDRMask(prefix.Bits(), prefix.Addr().BitLen()),
}
}
func (t *NativeTun) UpdateRouteOptions(tunOptions Options) error {
if t.options.FileDescriptor > 0 {
return nil
} else if !t.options.AutoRoute {
t.options = tunOptions
return nil
}
tunLink, err := netlink.LinkByName(t.options.Name)
if err != nil {
return err
}
err = t.unsetRoute0(tunLink)
if err != nil {
return err
}
t.options = tunOptions
return t.setRoute(tunLink)
}
func (t *NativeTun) routes(tunLink netlink.Link) ([]netlink.Route, error) {
routeRanges, err := t.options.BuildAutoRouteRanges(false)
if err != nil {
return nil, err
}
// Do not create gateway on linux by default
gateway4, gateway6 := t.options.Inet4GatewayAddr(), t.options.Inet6GatewayAddr()
return common.Map(routeRanges, func(it netip.Prefix) netlink.Route {
var gateway net.IP
if it.Addr().Is4() && !gateway4.IsUnspecified() {
gateway = gateway4.AsSlice()
} else if it.Addr().Is6() && !gateway6.IsUnspecified() {
gateway = gateway6.AsSlice()
}
return netlink.Route{
Dst: prefixToIPNet(it),
Gw: gateway,
LinkIndex: tunLink.Attrs().Index,
Table: t.options.IPRoute2TableIndex,
}
}), nil
}
func (t *NativeTun) nextIndex6() int {
ruleList, err := netlink.RuleList(netlink.FAMILY_V6)
if err != nil {
return -1
}
var minIndex int
for _, rule := range ruleList {
if rule.Priority > 0 && (minIndex == 0 || rule.Priority < minIndex) {
minIndex = rule.Priority
}
}
minIndex--
t.ruleIndex6 = append(t.ruleIndex6, minIndex)
return minIndex
}
func (t *NativeTun) rules() []*netlink.Rule {
if !t.options.AutoRoute {
if len(t.options.Inet6Address) > 0 {
it := netlink.NewRule()
it.Priority = t.nextIndex6()
it.Table = t.options.IPRoute2TableIndex
it.Family = unix.AF_INET6
it.OifName = t.options.Name
return []*netlink.Rule{it}
}
return nil
}
var p4, p6 bool
var pRule int
if len(t.options.Inet4Address) > 0 {
p4 = true
pRule += 1
}
if len(t.options.Inet6Address) > 0 {
p6 = true
pRule += 1
}
if pRule == 0 {
return []*netlink.Rule{}
}
var rules []*netlink.Rule
var it *netlink.Rule
excludeRanges := t.options.ExcludedRanges()
ruleStart := t.options.IPRoute2RuleIndex
priority := ruleStart
priority6 := priority
if t.options.AutoRedirectMarkMode {
if p4 {
it = netlink.NewRule()
it.Priority = priority
it.Mark = t.options.AutoRedirectOutputMark
it.MarkSet = true
it.Goto = priority + 2
it.Family = unix.AF_INET
rules = append(rules, it)
priority++
it = netlink.NewRule()
it.Priority = priority
it.Mark = t.options.AutoRedirectInputMark
it.MarkSet = true
it.Table = t.options.IPRoute2TableIndex
it.Family = unix.AF_INET
rules = append(rules, it)
priority++
it = netlink.NewRule()
it.Priority = priority
it.Family = unix.AF_INET
rules = append(rules, it)
}
if p6 {
it = netlink.NewRule()
it.Priority = priority6
it.Mark = t.options.AutoRedirectOutputMark
it.MarkSet = true
it.Goto = priority6 + 2
it.Family = unix.AF_INET6
rules = append(rules, it)
priority6++
it = netlink.NewRule()
it.Priority = priority6
it.Mark = t.options.AutoRedirectInputMark
it.MarkSet = true
it.Table = t.options.IPRoute2TableIndex
it.Family = unix.AF_INET6
rules = append(rules, it)
priority6++
it = netlink.NewRule()
it.Priority = priority6
it.Family = unix.AF_INET6
rules = append(rules, it)
}
return rules
}
nopPriority := ruleStart + 10
for _, excludeRange := range excludeRanges {
if p4 {
it = netlink.NewRule()
it.Priority = priority
it.UIDRange = netlink.NewRuleUIDRange(excludeRange.Start, excludeRange.End)
it.Goto = nopPriority
it.Family = unix.AF_INET
rules = append(rules, it)
}
if p6 {
it = netlink.NewRule()
it.Priority = priority6
it.UIDRange = netlink.NewRuleUIDRange(excludeRange.Start, excludeRange.End)
it.Goto = nopPriority
it.Family = unix.AF_INET6
rules = append(rules, it)
}
}
if len(excludeRanges) > 0 {
if p4 {
priority++
}
if p6 {
priority6++
}
}
if len(t.options.IncludeInterface) > 0 {
matchPriority := priority + 2*len(t.options.IncludeInterface) + 1
for _, includeInterface := range t.options.IncludeInterface {
if p4 {
it = netlink.NewRule()
it.Priority = priority
it.IifName = includeInterface
it.Goto = matchPriority
it.Family = unix.AF_INET
rules = append(rules, it)
priority++
}
if p6 {
it = netlink.NewRule()
it.Priority = priority6
it.IifName = includeInterface
it.Goto = matchPriority
it.Family = unix.AF_INET6
rules = append(rules, it)
priority6++
}
}
if p4 {
it = netlink.NewRule()
it.Priority = priority
it.Family = unix.AF_INET
it.Goto = nopPriority
rules = append(rules, it)
priority++
it = netlink.NewRule()
it.Priority = matchPriority
it.Family = unix.AF_INET
rules = append(rules, it)
priority++
}
if p6 {
it = netlink.NewRule()
it.Priority = priority6
it.Family = unix.AF_INET6
it.Goto = nopPriority
rules = append(rules, it)
priority6++
it = netlink.NewRule()
it.Priority = matchPriority
it.Family = unix.AF_INET6
rules = append(rules, it)
priority6++
}
} else if len(t.options.ExcludeInterface) > 0 {
for _, excludeInterface := range t.options.ExcludeInterface {
if p4 {
it = netlink.NewRule()
it.Priority = priority
it.IifName = excludeInterface
it.Goto = nopPriority
it.Family = unix.AF_INET
rules = append(rules, it)
priority++
}
if p6 {
it = netlink.NewRule()
it.Priority = priority6
it.IifName = excludeInterface
it.Goto = nopPriority
it.Family = unix.AF_INET6
rules = append(rules, it)
priority6++
}
}
}
if runtime.GOOS == "android" && t.options.InterfaceMonitor.AndroidVPNEnabled() {
const protectedFromVPN = 0x20000
if p4 {
it = netlink.NewRule()
if t.options.InterfaceMonitor.OverrideAndroidVPN() {
it.Mark = protectedFromVPN
it.MarkSet = true
}
it.Mask = protectedFromVPN
it.Priority = priority
it.Family = unix.AF_INET
it.Goto = nopPriority
rules = append(rules, it)
priority++
}
if p6 {
it = netlink.NewRule()
if t.options.InterfaceMonitor.OverrideAndroidVPN() {
it.Mark = protectedFromVPN
it.MarkSet = true
}
it.Mask = protectedFromVPN
it.Family = unix.AF_INET6
it.Priority = priority6
it.Goto = nopPriority
rules = append(rules, it)
priority6++
}
}
if t.options.StrictRoute {
if !p4 {
it = netlink.NewRule()
it.Priority = priority
it.Family = unix.AF_INET
it.Type = unix.FR_ACT_UNREACHABLE
rules = append(rules, it)
priority++
}
if !p6 {
it = netlink.NewRule()
it.Priority = priority6
it.Family = unix.AF_INET6
it.Type = unix.FR_ACT_UNREACHABLE
rules = append(rules, it)
priority6++
}
}
if runtime.GOOS != "android" {
if p4 {
for _, address := range t.options.Inet4Address {
it = netlink.NewRule()
it.Priority = priority
it.Dst = address.Masked()
it.Table = t.options.IPRoute2TableIndex
it.Family = unix.AF_INET
rules = append(rules, it)
}
priority++
it = netlink.NewRule()
it.Priority = priority
it.Table = t.options.IPRoute2TableIndex
it.SuppressPrefixlen = 0
it.Family = unix.AF_INET
rules = append(rules, it)
priority++
}
if p6 {
it = netlink.NewRule()
it.Priority = priority6
it.Table = t.options.IPRoute2TableIndex
it.SuppressPrefixlen = 0
it.Family = unix.AF_INET6
rules = append(rules, it)
priority6++
}
if p4 {
it = netlink.NewRule()
it.Priority = priority
it.Invert = true
it.Dport = netlink.NewRulePortRange(53, 53)
it.Table = unix.RT_TABLE_MAIN
it.SuppressPrefixlen = 0
it.Family = unix.AF_INET
rules = append(rules, it)
}
if p4 && !t.options.StrictRoute {
it = netlink.NewRule()
it.Priority = priority
it.IPProto = syscall.IPPROTO_ICMP
it.Goto = nopPriority
it.Family = unix.AF_INET
rules = append(rules, it)
}
if p6 {
it = netlink.NewRule()
it.Priority = priority6
it.Invert = true
it.Dport = netlink.NewRulePortRange(53, 53)
it.Table = unix.RT_TABLE_MAIN
it.SuppressPrefixlen = 0
it.Family = unix.AF_INET6
rules = append(rules, it)
}
if p6 && !t.options.StrictRoute {
it = netlink.NewRule()
it.Priority = priority6
it.IPProto = syscall.IPPROTO_ICMPV6
it.Goto = nopPriority
it.Family = unix.AF_INET6
rules = append(rules, it)
priority6++
}
}
if p4 {
it = netlink.NewRule()
it.Priority = priority
it.IifName = t.options.Name
it.Goto = nopPriority
it.Family = unix.AF_INET
rules = append(rules, it)
priority++
it = netlink.NewRule()
it.Priority = priority
it.Invert = true
it.IifName = "lo"
it.Table = t.options.IPRoute2TableIndex
it.Family = unix.AF_INET
rules = append(rules, it)
it = netlink.NewRule()
it.Priority = priority
it.IifName = "lo"
it.Src = netip.PrefixFrom(netip.IPv4Unspecified(), 32)
it.Table = t.options.IPRoute2TableIndex
it.Family = unix.AF_INET
rules = append(rules, it)
for _, address := range t.options.Inet4Address {
it = netlink.NewRule()
it.Priority = priority
it.IifName = "lo"
it.Src = address.Masked()
it.Table = t.options.IPRoute2TableIndex
it.Family = unix.AF_INET
rules = append(rules, it)
}
// priority++
}
if p6 {
it = netlink.NewRule()
it.Priority = priority6
it.IifName = t.options.Name
it.Goto = nopPriority
it.Family = unix.AF_INET6
rules = append(rules, it)
it = netlink.NewRule()
it.Priority = priority6
it.IifName = "lo"
it.Src = netip.PrefixFrom(netip.IPv6Unspecified(), 1)
it.Goto = nopPriority
it.Family = unix.AF_INET6
rules = append(rules, it)
it = netlink.NewRule()
it.Priority = priority6
it.IifName = "lo"
it.Src = netip.PrefixFrom(netip.AddrFrom16([16]byte{0: 128}), 1)
it.Goto = nopPriority
it.Family = unix.AF_INET6
rules = append(rules, it)
priority6++
for _, address := range t.options.Inet6Address {
it = netlink.NewRule()
it.Priority = priority6
it.IifName = "lo"
it.Src = address.Masked()
it.Table = t.options.IPRoute2TableIndex
it.Family = unix.AF_INET6
rules = append(rules, it)
}
priority6++
it = netlink.NewRule()
it.Priority = priority6
it.Table = t.options.IPRoute2TableIndex
it.Family = unix.AF_INET6
rules = append(rules, it)
// priority6++
}
if p4 {
it = netlink.NewRule()
it.Priority = nopPriority
it.Family = unix.AF_INET
rules = append(rules, it)
}
if p6 {
it = netlink.NewRule()
it.Priority = nopPriority
it.Family = unix.AF_INET6
rules = append(rules, it)
}
return rules
}
func (t *NativeTun) setRoute(tunLink netlink.Link) error {
routes, err := t.routes(tunLink)
if err != nil {
return err
}
for i, route := range routes {
err := netlink.RouteAdd(&route)
if err != nil {
return E.Cause(err, "add route ", i)
}
}
return nil
}
func (t *NativeTun) setRules() error {
for i, rule := range t.rules() {
err := netlink.RuleAdd(rule)
if err != nil {
return E.Cause(err, "add rule ", i, "/", len(t.rules()))
}
}
return nil
}
func (t *NativeTun) unsetRoute() error {
if t.options.FileDescriptor > 0 {
return nil
}
tunLink, err := netlink.LinkByName(t.options.Name)
if err != nil {
return err
}
return t.unsetRoute0(tunLink)
}
func (t *NativeTun) unsetRoute0(tunLink netlink.Link) error {
if routes, err := t.routes(tunLink); err == nil {
for _, route := range routes {
_ = netlink.RouteDel(&route)
}
}
return nil
}
func (t *NativeTun) unsetRules() error {
if t.options.FileDescriptor > 0 {
return nil
}
if len(t.ruleIndex6) > 0 {
for _, index := range t.ruleIndex6 {
ruleToDel := netlink.NewRule()
ruleToDel.Family = unix.AF_INET6
ruleToDel.Priority = index
err := netlink.RuleDel(ruleToDel)
if err != nil {
return E.Cause(err, "unset rule6 ", index)
}
}
t.ruleIndex6 = nil
}
if t.options.AutoRoute {
ruleList, err := netlink.RuleList(netlink.FAMILY_ALL)
if err != nil {
return err
}
for _, rule := range ruleList {
ruleStart := t.options.IPRoute2RuleIndex
ruleEnd := ruleStart + 10
if rule.Priority >= ruleStart && rule.Priority <= ruleEnd {
ruleToDel := netlink.NewRule()
ruleToDel.Family = rule.Family
ruleToDel.Priority = rule.Priority
err = netlink.RuleDel(ruleToDel)
if err != nil {
return E.Cause(err, "unset rule ", rule.Priority, " for ", rule.Family)
}
}
}
}
return nil
}
func (t *NativeTun) resetRules() error {
t.unsetRules()
return t.setRules()
}
func (t *NativeTun) routeUpdate(_ *control.Interface, flags int) {
if flags&FlagAndroidVPNUpdate == 0 {
return
}
err := t.resetRules()
if err != nil {
if t.options.Logger != nil {
t.options.Logger.Error(E.Cause(err, "reset route"))
}
}
}
func (t *NativeTun) setSearchDomainForSystemdResolved() {
if t.options.EXP_DisableDNSHijack {
return
}
ctlPath, err := exec.LookPath("resolvectl")
if err != nil {
return
}
dnsServer := t.options.DNSServers
if len(dnsServer) == 0 {
if len(t.options.Inet4Address) > 0 && HasNextAddress(t.options.Inet4Address[0], 1) {
dnsServer = append(dnsServer, t.options.Inet4Address[0].Addr().Next())
}
if len(t.options.Inet6Address) > 0 && HasNextAddress(t.options.Inet6Address[0], 1) {
dnsServer = append(dnsServer, t.options.Inet6Address[0].Addr().Next())
}
}
if len(dnsServer) == 0 {
return
}
go func() {
_ = shell.Exec(ctlPath, "domain", t.options.Name, "~.").Run()
_ = shell.Exec(ctlPath, "default-route", t.options.Name, "true").Run()
_ = shell.Exec(ctlPath, append([]string{"dns", t.options.Name}, common.Map(dnsServer, netip.Addr.String)...)...).Run()
}()
}