mihomo/transport/vless/conn.go
2023-02-25 14:01:59 +08:00

492 lines
12 KiB
Go

package vless
import (
"bytes"
"crypto/subtle"
gotls "crypto/tls"
"encoding/binary"
"errors"
"fmt"
"io"
"net"
"reflect"
"sync"
"unsafe"
"github.com/Dreamacro/clash/common/buf"
N "github.com/Dreamacro/clash/common/net"
tlsC "github.com/Dreamacro/clash/component/tls"
"github.com/Dreamacro/clash/log"
"github.com/gofrs/uuid"
utls "github.com/sagernet/utls"
xtls "github.com/xtls/go"
"google.golang.org/protobuf/proto"
)
type Conn struct {
N.ExtendedWriter
N.ExtendedReader
net.Conn
dst *DstAddr
id *uuid.UUID
addons *Addons
received bool
handshake chan struct{}
handshakeMutex sync.Mutex
err error
tlsConn net.Conn
input *bytes.Reader
rawInput *bytes.Buffer
packetsToFilter int
isTLS bool
isTLS12orAbove bool
enableXTLS bool
cipher uint16
remainingServerHello uint16
readRemainingContent int
readRemainingPadding int
readProcess bool
readFilterUUID bool
readLastCommand byte
writeFilterApplicationData bool
writeDirect bool
}
func (vc *Conn) Read(b []byte) (int, error) {
if vc.received {
if vc.readProcess {
buffer := buf.With(b)
err := vc.ReadBuffer(buffer)
return buffer.Len(), err
}
return vc.ExtendedReader.Read(b)
}
if err := vc.recvResponse(); err != nil {
return 0, err
}
vc.received = true
return vc.Read(b)
}
func (vc *Conn) ReadBuffer(buffer *buf.Buffer) error {
if vc.received {
toRead := buffer.FreeBytes()
if vc.readRemainingContent > 0 {
if vc.readRemainingContent < buffer.FreeLen() {
toRead = toRead[:vc.readRemainingContent]
}
n, err := vc.ExtendedReader.Read(toRead)
buffer.Truncate(n)
vc.readRemainingContent -= n
vc.FilterTLS(toRead)
return err
}
if vc.readRemainingPadding > 0 {
_, err := io.CopyN(io.Discard, vc.ExtendedReader, int64(vc.readRemainingPadding))
if err != nil {
return err
}
vc.readRemainingPadding = 0
}
if vc.readProcess {
switch vc.readLastCommand {
case commandPaddingContinue:
//if vc.isTLS || vc.packetsToFilter > 0 {
headerUUIDLen := 0
if vc.readFilterUUID {
headerUUIDLen = uuid.Size
}
var header []byte
if need := headerUUIDLen + paddingHeaderLen; buffer.FreeLen() < need {
header = make([]byte, need)
} else {
header = buffer.FreeBytes()[:need]
}
_, err := io.ReadFull(vc.ExtendedReader, header)
if err != nil {
return err
}
pos := 0
if vc.readFilterUUID {
vc.readFilterUUID = false
pos = uuid.Size
if subtle.ConstantTimeCompare(vc.id.Bytes(), header[:uuid.Size]) != 1 {
err = fmt.Errorf("XTLS Vision server responded unknown UUID: %s",
uuid.FromBytesOrNil(header[:uuid.Size]).String())
log.Errorln(err.Error())
return err
}
}
vc.readLastCommand = header[pos]
vc.readRemainingContent = int(binary.BigEndian.Uint16(header[pos+1:]))
vc.readRemainingPadding = int(binary.BigEndian.Uint16(header[pos+3:]))
log.Debugln("XTLS Vision read padding: command=%d, payloadLen=%d, paddingLen=%d",
vc.readLastCommand, vc.readRemainingContent, vc.readRemainingPadding)
return vc.ReadBuffer(buffer)
//}
case commandPaddingEnd:
vc.readProcess = false
return vc.ReadBuffer(buffer)
case commandPaddingDirect:
if vc.input != nil {
_, err := buffer.ReadFrom(vc.input)
if err != nil {
return err
}
if vc.input.Len() == 0 {
vc.input = nil
}
if buffer.IsFull() {
return nil
}
}
if vc.rawInput != nil {
_, err := buffer.ReadFrom(vc.rawInput)
if err != nil {
return err
}
if vc.rawInput.Len() == 0 {
vc.rawInput = nil
}
}
if vc.input == nil && vc.rawInput == nil {
vc.readProcess = false
vc.ExtendedReader = N.NewExtendedReader(vc.Conn)
log.Debugln("XTLS Vision direct read start")
}
default:
err := fmt.Errorf("XTLS Vision read unknown command: %d", vc.readLastCommand)
log.Debugln(err.Error())
return err
}
}
return vc.ExtendedReader.ReadBuffer(buffer)
}
if err := vc.recvResponse(); err != nil {
return err
}
vc.received = true
return vc.ReadBuffer(buffer)
}
func (vc *Conn) Write(p []byte) (int, error) {
select {
case <-vc.handshake:
default:
if vc.sendRequest(p) {
if vc.err != nil {
return 0, vc.err
}
return len(p), vc.err
}
if vc.err != nil {
return 0, vc.err
}
}
if vc.writeFilterApplicationData {
_buffer := buf.StackNew()
defer buf.KeepAlive(_buffer)
buffer := buf.Dup(_buffer)
defer buffer.Release()
buffer.Write(p)
err := vc.WriteBuffer(buffer)
if err != nil {
return 0, err
}
return len(p), nil
}
return vc.ExtendedWriter.Write(p)
}
func (vc *Conn) WriteBuffer(buffer *buf.Buffer) error {
select {
case <-vc.handshake:
default:
if vc.sendRequest(buffer.Bytes()) {
return vc.err
}
if vc.err != nil {
return vc.err
}
}
if vc.writeFilterApplicationData && vc.isTLS {
buffer2 := ReshapeBuffer(buffer)
defer buffer2.Release()
vc.FilterTLS(buffer.Bytes())
command := commandPaddingContinue
if buffer.Len() > 6 && bytes.Equal(buffer.To(3), tlsApplicationDataStart) || vc.packetsToFilter <= 0 {
command = commandPaddingEnd
if vc.enableXTLS {
command = commandPaddingDirect
vc.writeDirect = true
}
vc.writeFilterApplicationData = false
}
ApplyPadding(buffer, command, nil)
err := vc.ExtendedWriter.WriteBuffer(buffer)
if err != nil {
return err
}
if vc.writeDirect {
vc.ExtendedWriter = N.NewExtendedWriter(vc.Conn)
log.Debugln("XTLS Vision direct write start")
//time.Sleep(10 * time.Millisecond)
}
if buffer2 != nil {
if vc.writeDirect {
return vc.ExtendedWriter.WriteBuffer(buffer2)
}
vc.FilterTLS(buffer2.Bytes())
command = commandPaddingContinue
if buffer2.Len() > 6 && bytes.Equal(buffer2.To(3), tlsApplicationDataStart) || vc.packetsToFilter <= 0 {
command = commandPaddingEnd
if vc.enableXTLS {
command = commandPaddingDirect
vc.writeDirect = true
}
vc.writeFilterApplicationData = false
}
ApplyPadding(buffer2, command, nil)
err = vc.ExtendedWriter.WriteBuffer(buffer2)
if vc.writeDirect {
vc.ExtendedWriter = N.NewExtendedWriter(vc.Conn)
log.Debugln("XTLS Vision direct write start")
//time.Sleep(10 * time.Millisecond)
}
}
return err
}
/*if vc.writeDirect {
log.Debugln("XTLS Vision Direct write, payloadLen=%d", buffer.Len())
}*/
return vc.ExtendedWriter.WriteBuffer(buffer)
}
func (vc *Conn) sendRequest(p []byte) bool {
vc.handshakeMutex.Lock()
defer vc.handshakeMutex.Unlock()
select {
case <-vc.handshake:
// The handshake has been completed before.
// So return false to remind the caller.
return false
default:
}
defer close(vc.handshake)
var addonsBytes []byte
if vc.addons != nil {
addonsBytes, vc.err = proto.Marshal(vc.addons)
if vc.err != nil {
return true
}
}
isVision := vc.IsXTLSVisionEnabled()
var buffer *buf.Buffer
if isVision {
_buffer := buf.StackNew()
defer buf.KeepAlive(_buffer)
buffer = buf.Dup(_buffer)
defer buffer.Release()
} else {
requestLen := 1 // protocol version
requestLen += 16 // UUID
requestLen += 1 // addons length
requestLen += len(addonsBytes)
requestLen += 1 // command
if !vc.dst.Mux {
requestLen += 2 // port
requestLen += 1 // addr type
requestLen += len(vc.dst.Addr)
}
requestLen += len(p)
_buffer := buf.StackNewSize(requestLen)
defer buf.KeepAlive(_buffer)
buffer = buf.Dup(_buffer)
defer buffer.Release()
}
buf.Must(
buffer.WriteByte(Version), // protocol version
buf.Error(buffer.Write(vc.id.Bytes())), // 16 bytes of uuid
buffer.WriteByte(byte(len(addonsBytes))),
buf.Error(buffer.Write(addonsBytes)),
)
if vc.dst.Mux {
buf.Must(buffer.WriteByte(CommandMux))
} else {
if vc.dst.UDP {
buf.Must(buffer.WriteByte(CommandUDP))
} else {
buf.Must(buffer.WriteByte(CommandTCP))
}
binary.BigEndian.PutUint16(buffer.Extend(2), vc.dst.Port)
buf.Must(
buffer.WriteByte(vc.dst.AddrType),
buf.Error(buffer.Write(vc.dst.Addr)),
)
}
if isVision && !vc.dst.UDP && !vc.dst.Mux {
if len(p) == 0 {
vc.packetsToFilter = 0
vc.writeFilterApplicationData = false
WriteWithPadding(buffer, nil, commandPaddingEnd, vc.id)
} else {
vc.FilterTLS(p)
if vc.isTLS {
WriteWithPadding(buffer, p, commandPaddingContinue, vc.id)
} else {
buf.Must(buf.Error(buffer.Write(p)))
vc.readProcess = false
vc.writeFilterApplicationData = false
vc.packetsToFilter = 0
}
}
} else {
buf.Must(buf.Error(buffer.Write(p)))
}
_, vc.err = vc.ExtendedWriter.Write(buffer.Bytes())
if vc.err != nil {
return true
}
if isVision {
switch underlying := vc.tlsConn.(type) {
case *gotls.Conn:
if underlying.ConnectionState().Version != gotls.VersionTLS13 {
vc.err = ErrNotTLS13
}
case *utls.UConn:
if underlying.ConnectionState().Version != utls.VersionTLS13 {
vc.err = ErrNotTLS13
}
default:
vc.err = fmt.Errorf(`failed to use %s, maybe "security" is not "tls" or "utls"`, vc.addons.Flow)
}
vc.tlsConn = nil
}
return true
}
func (vc *Conn) recvResponse() error {
var buf [1]byte
_, vc.err = io.ReadFull(vc.ExtendedReader, buf[:])
if vc.err != nil {
return vc.err
}
if buf[0] != Version {
return errors.New("unexpected response version")
}
_, vc.err = io.ReadFull(vc.ExtendedReader, buf[:])
if vc.err != nil {
return vc.err
}
length := int64(buf[0])
if length != 0 { // addon data length > 0
io.CopyN(io.Discard, vc.ExtendedReader, length) // just discard
}
return nil
}
func (vc *Conn) FrontHeadroom() int {
if vc.IsXTLSVisionEnabled() {
return paddingHeaderLen
}
return 0
}
func (vc *Conn) Upstream() any {
if vc.tlsConn == nil {
return vc.Conn
}
return vc.tlsConn
}
func (vc *Conn) IsXTLSVisionEnabled() bool {
return vc.addons != nil && vc.addons.Flow == XRV
}
// newConn return a Conn instance
func newConn(conn net.Conn, client *Client, dst *DstAddr) (*Conn, error) {
c := &Conn{
ExtendedReader: N.NewExtendedReader(conn),
ExtendedWriter: N.NewExtendedWriter(conn),
Conn: conn,
id: client.uuid,
dst: dst,
handshake: make(chan struct{}),
}
if !dst.UDP && client.Addons != nil {
switch client.Addons.Flow {
case XRO, XRD, XRS:
if xtlsConn, ok := conn.(*xtls.Conn); ok {
xtlsConn.RPRX = true
xtlsConn.SHOW = client.XTLSShow
xtlsConn.MARK = "XTLS"
if client.Addons.Flow == XRS {
client.Addons.Flow = XRD
}
if client.Addons.Flow == XRD {
xtlsConn.DirectMode = true
}
c.addons = client.Addons
} else {
return nil, fmt.Errorf("failed to use %s, maybe \"security\" is not \"xtls\"", client.Addons.Flow)
}
case XRV:
c.packetsToFilter = 6
c.readProcess = true
c.readFilterUUID = true
c.writeFilterApplicationData = true
c.addons = client.Addons
var t reflect.Type
var p uintptr
switch underlying := conn.(type) {
case *gotls.Conn:
c.Conn = underlying.NetConn()
c.tlsConn = underlying
t = reflect.TypeOf(underlying).Elem()
p = uintptr(unsafe.Pointer(underlying))
case *utls.UConn:
c.Conn = underlying.NetConn()
c.tlsConn = underlying
t = reflect.TypeOf(underlying.Conn).Elem()
p = uintptr(unsafe.Pointer(underlying.Conn))
case *tlsC.UConn:
c.Conn = underlying.NetConn()
c.tlsConn = underlying.UConn
t = reflect.TypeOf(underlying.Conn).Elem()
p = uintptr(unsafe.Pointer(underlying.Conn))
default:
return nil, fmt.Errorf(`failed to use %s, maybe "security" is not "tls" or "utls"`, client.Addons.Flow)
}
i, _ := t.FieldByName("input")
r, _ := t.FieldByName("rawInput")
c.input = (*bytes.Reader)(unsafe.Pointer(p + i.Offset))
c.rawInput = (*bytes.Buffer)(unsafe.Pointer(p + r.Offset))
if _, ok := c.Conn.(*net.TCPConn); !ok {
log.Debugln("XTLS underlying conn is not *net.TCPConn, got %s", reflect.TypeOf(conn).Name())
}
}
}
return c, nil
}