package vless import ( "bytes" "crypto/rand" "crypto/tls" "io" "math/big" "net" "reflect" "time" "unsafe" C "github.com/sagernet/sing-box/constant" "github.com/sagernet/sing/common" "github.com/sagernet/sing/common/buf" "github.com/sagernet/sing/common/bufio" E "github.com/sagernet/sing/common/exceptions" "github.com/sagernet/sing/common/logger" N "github.com/sagernet/sing/common/network" ) var tlsRegistry []func(conn net.Conn) (loaded bool, netConn net.Conn, reflectType reflect.Type, reflectPointer uintptr) func init() { tlsRegistry = append(tlsRegistry, func(conn net.Conn) (loaded bool, netConn net.Conn, reflectType reflect.Type, reflectPointer uintptr) { tlsConn, loaded := conn.(*tls.Conn) if !loaded { return } return true, tlsConn.NetConn(), reflect.TypeOf(tlsConn).Elem(), uintptr(unsafe.Pointer(tlsConn)) }) } const xrayChunkSize = 8192 type VisionConn struct { net.Conn reader *bufio.ChunkReader writer N.VectorisedWriter input *bytes.Reader rawInput *bytes.Buffer netConn net.Conn logger logger.Logger userUUID [16]byte isTLS bool numberOfPacketToFilter int isTLS12orAbove bool remainingServerHello int32 cipher uint16 enableXTLS bool isPadding bool directWrite bool writeUUID bool withinPaddingBuffers bool remainingContent int remainingPadding int currentCommand int directRead bool remainingReader io.Reader } func NewVisionConn(conn net.Conn, userUUID [16]byte, logger logger.Logger) (*VisionConn, error) { var ( loaded bool reflectType reflect.Type reflectPointer uintptr netConn net.Conn ) for _, tlsCreator := range tlsRegistry { loaded, netConn, reflectType, reflectPointer = tlsCreator(conn) if loaded { break } } if !loaded { return nil, C.ErrTLSRequired } input, _ := reflectType.FieldByName("input") rawInput, _ := reflectType.FieldByName("rawInput") return &VisionConn{ Conn: conn, reader: bufio.NewChunkReader(conn, xrayChunkSize), writer: bufio.NewVectorisedWriter(conn), input: (*bytes.Reader)(unsafe.Pointer(reflectPointer + input.Offset)), rawInput: (*bytes.Buffer)(unsafe.Pointer(reflectPointer + rawInput.Offset)), netConn: netConn, logger: logger, userUUID: userUUID, numberOfPacketToFilter: 8, remainingServerHello: -1, isPadding: true, writeUUID: true, withinPaddingBuffers: true, remainingContent: -1, remainingPadding: -1, }, nil } func (c *VisionConn) Read(p []byte) (n int, err error) { if c.remainingReader != nil { n, err = c.remainingReader.Read(p) if err == io.EOF { c.remainingReader = nil } if n > 0 { return } } if c.directRead { return c.netConn.Read(p) } var bufferBytes []byte if len(p) > xrayChunkSize { n, err = c.Conn.Read(p) if err != nil { return } bufferBytes = p[:n] } else { buffer, err := c.reader.ReadChunk() if err != nil { return 0, err } defer buffer.FullReset() bufferBytes = buffer.Bytes() } if c.withinPaddingBuffers || c.numberOfPacketToFilter > 0 { buffers := c.unPadding(bufferBytes) if c.remainingContent == 0 && c.remainingPadding == 0 { if c.currentCommand == 1 { c.withinPaddingBuffers = false c.remainingContent = -1 c.remainingPadding = -1 } else if c.currentCommand == 2 { c.withinPaddingBuffers = false c.directRead = true inputBuffer, err := io.ReadAll(c.input) if err != nil { return 0, err } buffers = append(buffers, inputBuffer) rawInputBuffer, err := io.ReadAll(c.rawInput) if err != nil { return 0, err } buffers = append(buffers, rawInputBuffer) c.logger.Trace("XtlsRead readV") } else if c.currentCommand == 0 { c.withinPaddingBuffers = true } else { return 0, E.New("unknown command ", c.currentCommand) } } else if c.remainingContent > 0 || c.remainingPadding > 0 { c.withinPaddingBuffers = true } else { c.withinPaddingBuffers = false } if c.numberOfPacketToFilter > 0 { c.filterTLS(buffers) } c.remainingReader = io.MultiReader(common.Map(buffers, func(it []byte) io.Reader { return bytes.NewReader(it) })...) return c.Read(p) } else { if c.numberOfPacketToFilter > 0 { c.filterTLS([][]byte{bufferBytes}) } return } } func (c *VisionConn) Write(p []byte) (n int, err error) { if c.numberOfPacketToFilter > 0 { c.filterTLS([][]byte{p}) } if c.isPadding { inputLen := len(p) buffers := reshapeBuffer(p) var specIndex int for i, buffer := range buffers { if c.isTLS && buffer.Len() > 6 && bytes.Equal(tlsApplicationDataStart, buffer.To(3)) { var command byte = commandPaddingEnd if c.enableXTLS { c.directWrite = true specIndex = i command = commandPaddingDirect } c.isPadding = false buffers[i] = c.padding(buffer, command) break } else if !c.isTLS12orAbove && c.numberOfPacketToFilter <= 1 { c.isPadding = false buffers[i] = c.padding(buffer, commandPaddingEnd) break } buffers[i] = c.padding(buffer, commandPaddingContinue) } if c.directWrite { encryptedBuffer := buffers[:specIndex+1] err = c.writer.WriteVectorised(encryptedBuffer) if err != nil { return } buffers = buffers[specIndex+1:] c.writer = bufio.NewVectorisedWriter(c.netConn) c.logger.Trace("XtlsWrite writeV ", specIndex, " ", buf.LenMulti(encryptedBuffer), " ", len(buffers)) time.Sleep(5 * time.Millisecond) // wtf } err = c.writer.WriteVectorised(buffers) if err == nil { n = inputLen } return } if c.directWrite { return c.netConn.Write(p) } else { return c.Conn.Write(p) } } func (c *VisionConn) filterTLS(buffers [][]byte) { for _, buffer := range buffers { c.numberOfPacketToFilter-- if len(buffer) > 6 { if buffer[0] == 22 && buffer[1] == 3 && buffer[2] == 3 { c.isTLS = true if buffer[5] == 2 { c.isTLS12orAbove = true c.remainingServerHello = (int32(buffer[3])<<8 | int32(buffer[4])) + 5 if len(buffer) >= 79 && c.remainingServerHello >= 79 { sessionIdLen := int32(buffer[43]) cipherSuite := buffer[43+sessionIdLen+1 : 43+sessionIdLen+3] c.cipher = uint16(cipherSuite[0])<<8 | uint16(cipherSuite[1]) } else { c.logger.Trace("XtlsFilterTls short server hello, tls 1.2 or older? ", len(buffer), " ", c.remainingServerHello) } } } else if bytes.Equal(tlsClientHandShakeStart, buffer[:2]) && buffer[5] == 1 { c.isTLS = true c.logger.Trace("XtlsFilterTls found tls client hello! ", len(buffer)) } } if c.remainingServerHello > 0 { end := int(c.remainingServerHello) if end > len(buffer) { end = len(buffer) } c.remainingServerHello -= int32(end) if bytes.Contains(buffer[:end], tls13SupportedVersions) { cipher, ok := tls13CipherSuiteDic[c.cipher] if ok && cipher != "TLS_AES_128_CCM_8_SHA256" { c.enableXTLS = true } c.logger.Trace("XtlsFilterTls found tls 1.3! ", len(buffer), " ", c.cipher, " ", c.enableXTLS) c.numberOfPacketToFilter = 0 return } else if c.remainingServerHello == 0 { c.logger.Trace("XtlsFilterTls found tls 1.2! ", len(buffer)) c.numberOfPacketToFilter = 0 return } } if c.numberOfPacketToFilter == 0 { c.logger.Trace("XtlsFilterTls stop filtering ", len(buffer)) } } } func (c *VisionConn) padding(buffer *buf.Buffer, command byte) *buf.Buffer { contentLen := 0 paddingLen := 0 if buffer != nil { contentLen = buffer.Len() } if contentLen < 900 && c.isTLS { l, _ := rand.Int(rand.Reader, big.NewInt(500)) paddingLen = int(l.Int64()) + 900 - contentLen } else { l, _ := rand.Int(rand.Reader, big.NewInt(256)) paddingLen = int(l.Int64()) } var bufferLen int if c.writeUUID { bufferLen += 16 } bufferLen += 5 if buffer != nil { bufferLen += buffer.Len() } bufferLen += paddingLen newBuffer := buf.NewSize(bufferLen) if c.writeUUID { common.Must1(newBuffer.Write(c.userUUID[:])) c.writeUUID = false } common.Must1(newBuffer.Write([]byte{command, byte(contentLen >> 8), byte(contentLen), byte(paddingLen >> 8), byte(paddingLen)})) if buffer != nil { common.Must1(newBuffer.Write(buffer.Bytes())) buffer.Release() } newBuffer.Extend(paddingLen) c.logger.Trace("XtlsPadding ", contentLen, " ", paddingLen, " ", command) return newBuffer } func (c *VisionConn) unPadding(buffer []byte) [][]byte { var bufferIndex int if c.remainingContent == -1 && c.remainingPadding == -1 { if len(buffer) >= 21 && bytes.Equal(c.userUUID[:], buffer[:16]) { bufferIndex = 16 c.remainingContent = 0 c.remainingPadding = 0 c.currentCommand = 0 } } if c.remainingContent == -1 && c.remainingPadding == -1 { return [][]byte{buffer} } var buffers [][]byte for bufferIndex < len(buffer) { if c.remainingContent <= 0 && c.remainingPadding <= 0 { if c.currentCommand == 1 { buffers = append(buffers, buffer[bufferIndex:]) break } else { paddingInfo := buffer[bufferIndex : bufferIndex+5] c.currentCommand = int(paddingInfo[0]) c.remainingContent = int(paddingInfo[1])<<8 | int(paddingInfo[2]) c.remainingPadding = int(paddingInfo[3])<<8 | int(paddingInfo[4]) bufferIndex += 5 c.logger.Trace("Xtls Unpadding new block ", bufferIndex, " ", c.remainingContent, " padding ", c.remainingPadding, " ", c.currentCommand) } } else if c.remainingContent > 0 { end := c.remainingContent if end > len(buffer)-bufferIndex { end = len(buffer) - bufferIndex } buffers = append(buffers, buffer[bufferIndex:bufferIndex+end]) c.remainingContent -= end bufferIndex += end } else { end := c.remainingPadding if end > len(buffer)-bufferIndex { end = len(buffer) - bufferIndex } c.remainingPadding -= end bufferIndex += end } if bufferIndex == len(buffer) { break } } return buffers } func (c *VisionConn) Upstream() any { return c.Conn }