XTLS: More separate uplink/downlink flags for splice copy (#4407)

- In 03131c72dbbfc13ba4ce8e1f9f65f43f3dda7372 new flags were added for uplink/downlink, but that was not suffcient
- Now that the traffic state contains all possible info
- Each inbound and outbound is responsible to set their own CanSpliceCopy flag. Note that this also open up more splice usage. E.g. socks in -> freedom out
- Fixes https://github.com/XTLS/Xray-core/issues/4033
This commit is contained in:
yuhan6665 2025-02-18 03:37:52 -05:00 committed by GitHub
parent a1714cc4ce
commit eef74b2c7d
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6 changed files with 132 additions and 67 deletions

View File

@ -151,6 +151,7 @@ func (c *Client) Process(ctx context.Context, link *transport.Link, dialer inter
return buf.Copy(link.Reader, buf.NewWriter(conn), buf.UpdateActivity(timer))
}
responseFunc := func() error {
ob.CanSpliceCopy = 1
defer timer.SetTimeout(p.Timeouts.UplinkOnly)
return buf.Copy(buf.NewReader(conn), link.Writer, buf.UpdateActivity(timer))
}

View File

@ -207,6 +207,7 @@ func (s *Server) handleConnect(ctx context.Context, _ *http.Request, reader *buf
}
responseDone := func() error {
inbound.CanSpliceCopy = 1
defer timer.SetTimeout(plcy.Timeouts.UplinkOnly)
v2writer := buf.NewWriter(conn)

View File

@ -107,19 +107,33 @@ type TrafficState struct {
IsTLS bool
Cipher uint16
RemainingServerHello int32
Inbound InboundState
Outbound OutboundState
}
type InboundState struct {
// reader link state
WithinPaddingBuffers bool
DownlinkReaderDirectCopy bool
UplinkReaderDirectCopy bool
RemainingCommand int32
RemainingContent int32
RemainingPadding int32
CurrentCommand int
// write link state
IsPadding bool
DownlinkWriterDirectCopy bool
}
type OutboundState struct {
// reader link state
WithinPaddingBuffers bool
DownlinkReaderDirectCopy bool
RemainingCommand int32
RemainingContent int32
RemainingPadding int32
CurrentCommand int
// write link state
IsPadding bool
UplinkWriterDirectCopy bool
}
@ -132,16 +146,26 @@ func NewTrafficState(userUUID []byte) *TrafficState {
IsTLS: false,
Cipher: 0,
RemainingServerHello: -1,
WithinPaddingBuffers: true,
DownlinkReaderDirectCopy: false,
UplinkReaderDirectCopy: false,
RemainingCommand: -1,
RemainingContent: -1,
RemainingPadding: -1,
CurrentCommand: 0,
IsPadding: true,
DownlinkWriterDirectCopy: false,
UplinkWriterDirectCopy: false,
Inbound: InboundState{
WithinPaddingBuffers: true,
UplinkReaderDirectCopy: false,
RemainingCommand: -1,
RemainingContent: -1,
RemainingPadding: -1,
CurrentCommand: 0,
IsPadding: true,
DownlinkWriterDirectCopy: false,
},
Outbound: OutboundState{
WithinPaddingBuffers: true,
DownlinkReaderDirectCopy: false,
RemainingCommand: -1,
RemainingContent: -1,
RemainingPadding: -1,
CurrentCommand: 0,
IsPadding: true,
UplinkWriterDirectCopy: false,
},
}
}
@ -166,28 +190,43 @@ func NewVisionReader(reader buf.Reader, state *TrafficState, isUplink bool, cont
func (w *VisionReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
buffer, err := w.Reader.ReadMultiBuffer()
if !buffer.IsEmpty() {
if w.trafficState.WithinPaddingBuffers || w.trafficState.NumberOfPacketToFilter > 0 {
var withinPaddingBuffers *bool
var remainingContent *int32
var remainingPadding *int32
var currentCommand *int
var switchToDirectCopy *bool
if w.isUplink {
withinPaddingBuffers = &w.trafficState.Inbound.WithinPaddingBuffers
remainingContent = &w.trafficState.Inbound.RemainingContent
remainingPadding = &w.trafficState.Inbound.RemainingPadding
currentCommand = &w.trafficState.Inbound.CurrentCommand
switchToDirectCopy = &w.trafficState.Inbound.UplinkReaderDirectCopy
} else {
withinPaddingBuffers = &w.trafficState.Outbound.WithinPaddingBuffers
remainingContent = &w.trafficState.Outbound.RemainingContent
remainingPadding = &w.trafficState.Outbound.RemainingPadding
currentCommand = &w.trafficState.Outbound.CurrentCommand
switchToDirectCopy = &w.trafficState.Outbound.DownlinkReaderDirectCopy
}
if *withinPaddingBuffers || w.trafficState.NumberOfPacketToFilter > 0 {
mb2 := make(buf.MultiBuffer, 0, len(buffer))
for _, b := range buffer {
newbuffer := XtlsUnpadding(b, w.trafficState, w.ctx)
newbuffer := XtlsUnpadding(b, w.trafficState, w.isUplink, w.ctx)
if newbuffer.Len() > 0 {
mb2 = append(mb2, newbuffer)
}
}
buffer = mb2
if w.trafficState.RemainingContent > 0 || w.trafficState.RemainingPadding > 0 || w.trafficState.CurrentCommand == 0 {
w.trafficState.WithinPaddingBuffers = true
} else if w.trafficState.CurrentCommand == 1 {
w.trafficState.WithinPaddingBuffers = false
} else if w.trafficState.CurrentCommand == 2 {
w.trafficState.WithinPaddingBuffers = false
if w.isUplink {
w.trafficState.UplinkReaderDirectCopy = true
} else {
w.trafficState.DownlinkReaderDirectCopy = true
}
if *remainingContent > 0 || *remainingPadding > 0 || *currentCommand == 0 {
*withinPaddingBuffers = true
} else if *currentCommand == 1 {
*withinPaddingBuffers = false
} else if *currentCommand == 2 {
*withinPaddingBuffers = false
*switchToDirectCopy = true
} else {
errors.LogInfo(w.ctx, "XtlsRead unknown command ", w.trafficState.CurrentCommand, buffer.Len())
errors.LogInfo(w.ctx, "XtlsRead unknown command ", *currentCommand, buffer.Len())
}
}
if w.trafficState.NumberOfPacketToFilter > 0 {
@ -223,7 +262,16 @@ func (w *VisionWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
if w.trafficState.NumberOfPacketToFilter > 0 {
XtlsFilterTls(mb, w.trafficState, w.ctx)
}
if w.trafficState.IsPadding {
var isPadding *bool
var switchToDirectCopy *bool
if w.isUplink {
isPadding = &w.trafficState.Outbound.IsPadding
switchToDirectCopy = &w.trafficState.Outbound.UplinkWriterDirectCopy
} else {
isPadding = &w.trafficState.Inbound.IsPadding
switchToDirectCopy = &w.trafficState.Inbound.DownlinkWriterDirectCopy
}
if *isPadding {
if len(mb) == 1 && mb[0] == nil {
mb[0] = XtlsPadding(nil, CommandPaddingContinue, &w.writeOnceUserUUID, true, w.ctx) // we do a long padding to hide vless header
return w.Writer.WriteMultiBuffer(mb)
@ -233,11 +281,7 @@ func (w *VisionWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
for i, b := range mb {
if w.trafficState.IsTLS && b.Len() >= 6 && bytes.Equal(TlsApplicationDataStart, b.BytesTo(3)) {
if w.trafficState.EnableXtls {
if w.isUplink {
w.trafficState.UplinkWriterDirectCopy = true
} else {
w.trafficState.DownlinkWriterDirectCopy = true
}
*switchToDirectCopy = true
}
var command byte = CommandPaddingContinue
if i == len(mb)-1 {
@ -247,16 +291,16 @@ func (w *VisionWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
}
}
mb[i] = XtlsPadding(b, command, &w.writeOnceUserUUID, true, w.ctx)
w.trafficState.IsPadding = false // padding going to end
*isPadding = false // padding going to end
longPadding = false
continue
} else if !w.trafficState.IsTLS12orAbove && w.trafficState.NumberOfPacketToFilter <= 1 { // For compatibility with earlier vision receiver, we finish padding 1 packet early
w.trafficState.IsPadding = false
*isPadding = false
mb[i] = XtlsPadding(b, CommandPaddingEnd, &w.writeOnceUserUUID, longPadding, w.ctx)
break
}
var command byte = CommandPaddingContinue
if i == len(mb)-1 && !w.trafficState.IsPadding {
if i == len(mb)-1 && !*isPadding {
command = CommandPaddingEnd
if w.trafficState.EnableXtls {
command = CommandPaddingDirect
@ -343,38 +387,53 @@ func XtlsPadding(b *buf.Buffer, command byte, userUUID *[]byte, longPadding bool
}
// XtlsUnpadding remove padding and parse command
func XtlsUnpadding(b *buf.Buffer, s *TrafficState, ctx context.Context) *buf.Buffer {
if s.RemainingCommand == -1 && s.RemainingContent == -1 && s.RemainingPadding == -1 { // initial state
func XtlsUnpadding(b *buf.Buffer, s *TrafficState, isUplink bool, ctx context.Context) *buf.Buffer {
var remainingCommand *int32
var remainingContent *int32
var remainingPadding *int32
var currentCommand *int
if isUplink {
remainingCommand = &s.Inbound.RemainingCommand
remainingContent = &s.Inbound.RemainingContent
remainingPadding = &s.Inbound.RemainingPadding
currentCommand = &s.Inbound.CurrentCommand
} else {
remainingCommand = &s.Outbound.RemainingCommand
remainingContent = &s.Outbound.RemainingContent
remainingPadding = &s.Outbound.RemainingPadding
currentCommand = &s.Outbound.CurrentCommand
}
if *remainingCommand == -1 && *remainingContent == -1 && *remainingPadding == -1 { // initial state
if b.Len() >= 21 && bytes.Equal(s.UserUUID, b.BytesTo(16)) {
b.Advance(16)
s.RemainingCommand = 5
*remainingCommand = 5
} else {
return b
}
}
newbuffer := buf.New()
for b.Len() > 0 {
if s.RemainingCommand > 0 {
if *remainingCommand > 0 {
data, err := b.ReadByte()
if err != nil {
return newbuffer
}
switch s.RemainingCommand {
switch *remainingCommand {
case 5:
s.CurrentCommand = int(data)
*currentCommand = int(data)
case 4:
s.RemainingContent = int32(data) << 8
*remainingContent = int32(data) << 8
case 3:
s.RemainingContent = s.RemainingContent | int32(data)
*remainingContent = *remainingContent | int32(data)
case 2:
s.RemainingPadding = int32(data) << 8
*remainingPadding = int32(data) << 8
case 1:
s.RemainingPadding = s.RemainingPadding | int32(data)
errors.LogInfo(ctx, "Xtls Unpadding new block, content ", s.RemainingContent, " padding ", s.RemainingPadding, " command ", s.CurrentCommand)
*remainingPadding = *remainingPadding | int32(data)
errors.LogInfo(ctx, "Xtls Unpadding new block, content ", *remainingContent, " padding ", *remainingPadding, " command ", *currentCommand)
}
s.RemainingCommand--
} else if s.RemainingContent > 0 {
len := s.RemainingContent
*remainingCommand--
} else if *remainingContent > 0 {
len := *remainingContent
if b.Len() < len {
len = b.Len()
}
@ -383,22 +442,22 @@ func XtlsUnpadding(b *buf.Buffer, s *TrafficState, ctx context.Context) *buf.Buf
return newbuffer
}
newbuffer.Write(data)
s.RemainingContent -= len
*remainingContent -= len
} else { // remainingPadding > 0
len := s.RemainingPadding
len := *remainingPadding
if b.Len() < len {
len = b.Len()
}
b.Advance(len)
s.RemainingPadding -= len
*remainingPadding -= len
}
if s.RemainingCommand <= 0 && s.RemainingContent <= 0 && s.RemainingPadding <= 0 { // this block done
if s.CurrentCommand == 0 {
s.RemainingCommand = 5
if *remainingCommand <= 0 && *remainingContent <= 0 && *remainingPadding <= 0 { // this block done
if *currentCommand == 0 {
*remainingCommand = 5
} else {
s.RemainingCommand = -1 // set to initial state
s.RemainingContent = -1
s.RemainingPadding = -1
*remainingCommand = -1 // set to initial state
*remainingContent = -1
*remainingPadding = -1
if b.Len() > 0 { // shouldn't happen
newbuffer.Write(b.Bytes())
}

View File

@ -146,6 +146,7 @@ func (c *Client) Process(ctx context.Context, link *transport.Link, dialer inter
return buf.Copy(link.Reader, buf.NewWriter(conn), buf.UpdateActivity(timer))
}
responseFunc = func() error {
ob.CanSpliceCopy = 1
defer timer.SetTimeout(p.Timeouts.UplinkOnly)
return buf.Copy(buf.NewReader(conn), link.Writer, buf.UpdateActivity(timer))
}
@ -161,6 +162,7 @@ func (c *Client) Process(ctx context.Context, link *transport.Link, dialer inter
return buf.Copy(link.Reader, writer, buf.UpdateActivity(timer))
}
responseFunc = func() error {
ob.CanSpliceCopy = 1
defer timer.SetTimeout(p.Timeouts.UplinkOnly)
reader := &UDPReader{Reader: udpConn}
return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer))

View File

@ -199,6 +199,7 @@ func (s *Server) transport(ctx context.Context, reader io.Reader, writer io.Writ
}
responseDone := func() error {
inbound.CanSpliceCopy = 1
defer timer.SetTimeout(plcy.Timeouts.UplinkOnly)
v2writer := buf.NewWriter(writer)
@ -256,6 +257,7 @@ func (s *Server) handleUDPPayload(ctx context.Context, conn stat.Connection, dis
if inbound != nil && inbound.Source.IsValid() {
errors.LogInfo(ctx, "client UDP connection from ", inbound.Source)
}
inbound.CanSpliceCopy = 1
var dest *net.Destination

View File

@ -175,16 +175,16 @@ func DecodeResponseHeader(reader io.Reader, request *protocol.RequestHeader) (*A
func XtlsRead(reader buf.Reader, writer buf.Writer, timer *signal.ActivityTimer, conn net.Conn, input *bytes.Reader, rawInput *bytes.Buffer, trafficState *proxy.TrafficState, ob *session.Outbound, isUplink bool, ctx context.Context) error {
err := func() error {
for {
if isUplink && trafficState.UplinkReaderDirectCopy || !isUplink && trafficState.DownlinkReaderDirectCopy {
if isUplink && trafficState.Inbound.UplinkReaderDirectCopy || !isUplink && trafficState.Outbound.DownlinkReaderDirectCopy {
var writerConn net.Conn
var inTimer *signal.ActivityTimer
if inbound := session.InboundFromContext(ctx); inbound != nil && inbound.Conn != nil {
writerConn = inbound.Conn
inTimer = inbound.Timer
if inbound.CanSpliceCopy == 2 {
if isUplink && inbound.CanSpliceCopy == 2 {
inbound.CanSpliceCopy = 1
}
if ob != nil && ob.CanSpliceCopy == 2 { // ob need to be passed in due to context can change
if !isUplink && ob != nil && ob.CanSpliceCopy == 2 { // ob need to be passed in due to context can change
ob.CanSpliceCopy = 1
}
}
@ -193,7 +193,7 @@ func XtlsRead(reader buf.Reader, writer buf.Writer, timer *signal.ActivityTimer,
buffer, err := reader.ReadMultiBuffer()
if !buffer.IsEmpty() {
timer.Update()
if isUplink && trafficState.UplinkReaderDirectCopy || !isUplink && trafficState.DownlinkReaderDirectCopy {
if isUplink && trafficState.Inbound.UplinkReaderDirectCopy || !isUplink && trafficState.Outbound.DownlinkReaderDirectCopy {
// XTLS Vision processes struct TLS Conn's input and rawInput
if inputBuffer, err := buf.ReadFrom(input); err == nil {
if !inputBuffer.IsEmpty() {
@ -227,12 +227,12 @@ func XtlsWrite(reader buf.Reader, writer buf.Writer, timer signal.ActivityUpdate
var ct stats.Counter
for {
buffer, err := reader.ReadMultiBuffer()
if isUplink && trafficState.UplinkWriterDirectCopy || !isUplink && trafficState.DownlinkWriterDirectCopy {
if isUplink && trafficState.Outbound.UplinkWriterDirectCopy || !isUplink && trafficState.Inbound.DownlinkWriterDirectCopy {
if inbound := session.InboundFromContext(ctx); inbound != nil {
if inbound.CanSpliceCopy == 2 {
if !isUplink && inbound.CanSpliceCopy == 2 {
inbound.CanSpliceCopy = 1
}
if ob != nil && ob.CanSpliceCopy == 2 {
if isUplink && ob != nil && ob.CanSpliceCopy == 2 {
ob.CanSpliceCopy = 1
}
}
@ -240,9 +240,9 @@ func XtlsWrite(reader buf.Reader, writer buf.Writer, timer signal.ActivityUpdate
writer = buf.NewWriter(rawConn)
ct = writerCounter
if isUplink {
trafficState.UplinkWriterDirectCopy = false
trafficState.Outbound.UplinkWriterDirectCopy = false
} else {
trafficState.DownlinkWriterDirectCopy = false
trafficState.Inbound.DownlinkWriterDirectCopy = false
}
}
if !buffer.IsEmpty() {