Update dependencies

vendor/github.com/coder/websocket/frame.go

@@ -0,0 +1,173 @@
+//go:build !js
+
+package websocket
+
+import (
+	"bufio"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"math"
+
+	"github.com/coder/websocket/internal/errd"
+)
+
+// opcode represents a WebSocket opcode.
+type opcode int
+
+// https://tools.ietf.org/html/rfc6455#section-11.8.
+const (
+	opContinuation opcode = iota
+	opText
+	opBinary
+	// 3 - 7 are reserved for further non-control frames.
+	_
+	_
+	_
+	_
+	_
+	opClose
+	opPing
+	opPong
+	// 11-16 are reserved for further control frames.
+)
+
+// header represents a WebSocket frame header.
+// See https://tools.ietf.org/html/rfc6455#section-5.2.
+type header struct {
+	fin    bool
+	rsv1   bool
+	rsv2   bool
+	rsv3   bool
+	opcode opcode
+
+	payloadLength int64
+
+	masked  bool
+	maskKey uint32
+}
+
+// readFrameHeader reads a header from the reader.
+// See https://tools.ietf.org/html/rfc6455#section-5.2.
+func readFrameHeader(r *bufio.Reader, readBuf []byte) (h header, err error) {
+	defer errd.Wrap(&err, "failed to read frame header")
+
+	b, err := r.ReadByte()
+	if err != nil {
+		return header{}, err
+	}
+
+	h.fin = b&(1<<7) != 0
+	h.rsv1 = b&(1<<6) != 0
+	h.rsv2 = b&(1<<5) != 0
+	h.rsv3 = b&(1<<4) != 0
+
+	h.opcode = opcode(b & 0xf)
+
+	b, err = r.ReadByte()
+	if err != nil {
+		return header{}, err
+	}
+
+	h.masked = b&(1<<7) != 0
+
+	payloadLength := b &^ (1 << 7)
+	switch {
+	case payloadLength < 126:
+		h.payloadLength = int64(payloadLength)
+	case payloadLength == 126:
+		_, err = io.ReadFull(r, readBuf[:2])
+		h.payloadLength = int64(binary.BigEndian.Uint16(readBuf))
+	case payloadLength == 127:
+		_, err = io.ReadFull(r, readBuf)
+		h.payloadLength = int64(binary.BigEndian.Uint64(readBuf))
+	}
+	if err != nil {
+		return header{}, err
+	}
+
+	if h.payloadLength < 0 {
+		return header{}, fmt.Errorf("received negative payload length: %v", h.payloadLength)
+	}
+
+	if h.masked {
+		_, err = io.ReadFull(r, readBuf[:4])
+		if err != nil {
+			return header{}, err
+		}
+		h.maskKey = binary.LittleEndian.Uint32(readBuf)
+	}
+
+	return h, nil
+}
+
+// maxControlPayload is the maximum length of a control frame payload.
+// See https://tools.ietf.org/html/rfc6455#section-5.5.
+const maxControlPayload = 125
+
+// writeFrameHeader writes the bytes of the header to w.
+// See https://tools.ietf.org/html/rfc6455#section-5.2
+func writeFrameHeader(h header, w *bufio.Writer, buf []byte) (err error) {
+	defer errd.Wrap(&err, "failed to write frame header")
+
+	var b byte
+	if h.fin {
+		b |= 1 << 7
+	}
+	if h.rsv1 {
+		b |= 1 << 6
+	}
+	if h.rsv2 {
+		b |= 1 << 5
+	}
+	if h.rsv3 {
+		b |= 1 << 4
+	}
+
+	b |= byte(h.opcode)
+
+	err = w.WriteByte(b)
+	if err != nil {
+		return err
+	}
+
+	lengthByte := byte(0)
+	if h.masked {
+		lengthByte |= 1 << 7
+	}
+
+	switch {
+	case h.payloadLength > math.MaxUint16:
+		lengthByte |= 127
+	case h.payloadLength > 125:
+		lengthByte |= 126
+	case h.payloadLength >= 0:
+		lengthByte |= byte(h.payloadLength)
+	}
+	err = w.WriteByte(lengthByte)
+	if err != nil {
+		return err
+	}
+
+	switch {
+	case h.payloadLength > math.MaxUint16:
+		binary.BigEndian.PutUint64(buf, uint64(h.payloadLength))
+		_, err = w.Write(buf)
+	case h.payloadLength > 125:
+		binary.BigEndian.PutUint16(buf, uint16(h.payloadLength))
+		_, err = w.Write(buf[:2])
+	}
+	if err != nil {
+		return err
+	}
+
+	if h.masked {
+		binary.LittleEndian.PutUint32(buf, h.maskKey)
+		_, err = w.Write(buf[:4])
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}