75 lines
1.5 KiB
Go
75 lines
1.5 KiB
Go
package v2raywebsocket
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import (
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"encoding/binary"
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"io"
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"math/rand"
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"github.com/sagernet/sing/common/buf"
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"github.com/sagernet/sing/common/bufio"
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N "github.com/sagernet/sing/common/network"
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"github.com/sagernet/ws"
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)
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type Writer struct {
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writer N.ExtendedWriter
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isServer bool
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}
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func NewWriter(writer io.Writer, state ws.State) *Writer {
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return &Writer{
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bufio.NewExtendedWriter(writer),
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state == ws.StateServerSide,
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}
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}
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func (w *Writer) WriteBuffer(buffer *buf.Buffer) error {
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var payloadBitLength int
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dataLen := buffer.Len()
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data := buffer.Bytes()
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if dataLen < 126 {
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payloadBitLength = 1
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} else if dataLen < 65536 {
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payloadBitLength = 3
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} else {
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payloadBitLength = 9
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}
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var headerLen int
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headerLen += 1 // FIN / RSV / OPCODE
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headerLen += payloadBitLength
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if !w.isServer {
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headerLen += 4 // MASK KEY
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}
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header := buffer.ExtendHeader(headerLen)
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header[0] = byte(ws.OpBinary) | 0x80
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if w.isServer {
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header[1] = 0
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} else {
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header[1] = 1 << 7
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}
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if dataLen < 126 {
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header[1] |= byte(dataLen)
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} else if dataLen < 65536 {
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header[1] |= 126
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binary.BigEndian.PutUint16(header[2:], uint16(dataLen))
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} else {
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header[1] |= 127
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binary.BigEndian.PutUint64(header[2:], uint64(dataLen))
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}
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if !w.isServer {
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maskKey := rand.Uint32()
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binary.BigEndian.PutUint32(header[1+payloadBitLength:], maskKey)
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ws.Cipher(data, *(*[4]byte)(header[1+payloadBitLength:]), 0)
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}
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return w.writer.WriteBuffer(buffer)
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}
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func (w *Writer) FrontHeadroom() int {
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return 14
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}
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