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@@ -0,0 +1,915 @@
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+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
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+// Use of this source code is governed by a BSD-style
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+// license that can be found in the LICENSE file.
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+
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+package websocket
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+
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+import (
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+ "bufio"
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+ "encoding/binary"
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+ "errors"
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+ "io"
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+ "io/ioutil"
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+ "math/rand"
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+ "net"
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+ "strconv"
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+ "time"
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+)
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+
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+const (
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+ maxFrameHeaderSize = 2 + 8 + 4 // Fixed header + length + mask
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+ maxControlFramePayloadSize = 125
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+ finalBit = 1 << 7
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+ maskBit = 1 << 7
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+ writeWait = time.Second
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+
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+ defaultReadBufferSize = 4096
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+ defaultWriteBufferSize = 4096
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+
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+ continuationFrame = 0
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+ noFrame = -1
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+)
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+
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+// Close codes defined in RFC 6455, section 11.7.
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+const (
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+ CloseNormalClosure = 1000
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+ CloseGoingAway = 1001
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+ CloseProtocolError = 1002
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+ CloseUnsupportedData = 1003
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+ CloseNoStatusReceived = 1005
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+ CloseAbnormalClosure = 1006
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+ CloseInvalidFramePayloadData = 1007
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+ ClosePolicyViolation = 1008
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+ CloseMessageTooBig = 1009
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+ CloseMandatoryExtension = 1010
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+ CloseInternalServerErr = 1011
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+ CloseTLSHandshake = 1015
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+)
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+
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+// The message types are defined in RFC 6455, section 11.8.
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+const (
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+ // TextMessage denotes a text data message. The text message payload is
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+ // interpreted as UTF-8 encoded text data.
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+ TextMessage = 1
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+
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+ // BinaryMessage denotes a binary data message.
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+ BinaryMessage = 2
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+
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+ // CloseMessage denotes a close control message. The optional message
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+ // payload contains a numeric code and text. Use the FormatCloseMessage
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+ // function to format a close message payload.
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+ CloseMessage = 8
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+
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+ // PingMessage denotes a ping control message. The optional message payload
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+ // is UTF-8 encoded text.
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+ PingMessage = 9
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+
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+ // PongMessage denotes a ping control message. The optional message payload
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+ // is UTF-8 encoded text.
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+ PongMessage = 10
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+)
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+
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+// ErrCloseSent is returned when the application writes a message to the
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+// connection after sending a close message.
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+var ErrCloseSent = errors.New("websocket: close sent")
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+
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+// ErrReadLimit is returned when reading a message that is larger than the
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+// read limit set for the connection.
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+var ErrReadLimit = errors.New("websocket: read limit exceeded")
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+
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+// netError satisfies the net Error interface.
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+type netError struct {
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+ msg string
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+ temporary bool
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+ timeout bool
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+}
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+
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+func (e *netError) Error() string { return e.msg }
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+func (e *netError) Temporary() bool { return e.temporary }
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+func (e *netError) Timeout() bool { return e.timeout }
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+
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+// CloseError represents close frame.
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+type CloseError struct {
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+
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+ // Code is defined in RFC 6455, section 11.7.
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+ Code int
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+
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+ // Text is the optional text payload.
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+ Text string
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+}
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+
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+func (e *CloseError) Error() string {
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+ s := []byte("websocket: close ")
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+ s = strconv.AppendInt(s, int64(e.Code), 10)
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+ switch e.Code {
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+ case CloseNormalClosure:
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+ s = append(s, " (normal)"...)
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+ case CloseGoingAway:
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+ s = append(s, " (going away)"...)
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+ case CloseProtocolError:
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+ s = append(s, " (protocol error)"...)
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+ case CloseUnsupportedData:
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+ s = append(s, " (unsupported data)"...)
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+ case CloseNoStatusReceived:
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+ s = append(s, " (no status)"...)
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+ case CloseAbnormalClosure:
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+ s = append(s, " (abnormal closure)"...)
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+ case CloseInvalidFramePayloadData:
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+ s = append(s, " (invalid payload data)"...)
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+ case ClosePolicyViolation:
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+ s = append(s, " (policy violation)"...)
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+ case CloseMessageTooBig:
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+ s = append(s, " (message too big)"...)
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+ case CloseMandatoryExtension:
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+ s = append(s, " (mandatory extension missing)"...)
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+ case CloseInternalServerErr:
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+ s = append(s, " (internal server error)"...)
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+ case CloseTLSHandshake:
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+ s = append(s, " (TLS handshake error)"...)
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+ }
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+ if e.Text != "" {
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+ s = append(s, ": "...)
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+ s = append(s, e.Text...)
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+ }
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+ return string(s)
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+}
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+
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+// IsCloseError returns boolean indicating whether the error is a *CloseError
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+// with one of the specified codes.
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+func IsCloseError(err error, codes ...int) bool {
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+ if e, ok := err.(*CloseError); ok {
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+ for _, code := range codes {
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+ if e.Code == code {
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+ return true
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+ }
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+ }
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+ }
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+ return false
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+}
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+
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+// IsUnexpectedCloseError returns boolean indicating whether the error is a
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+// *CloseError with a code not in the list of expected codes.
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+func IsUnexpectedCloseError(err error, expectedCodes ...int) bool {
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+ if e, ok := err.(*CloseError); ok {
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+ for _, code := range expectedCodes {
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+ if e.Code == code {
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+ return false
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+ }
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+ }
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+ return true
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+ }
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+ return false
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+}
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+
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+var (
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+ errWriteTimeout = &netError{msg: "websocket: write timeout", timeout: true, temporary: true}
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+ errUnexpectedEOF = &CloseError{Code: CloseAbnormalClosure, Text: io.ErrUnexpectedEOF.Error()}
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+ errBadWriteOpCode = errors.New("websocket: bad write message type")
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+ errWriteClosed = errors.New("websocket: write closed")
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+ errInvalidControlFrame = errors.New("websocket: invalid control frame")
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+)
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+
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+func hideTempErr(err error) error {
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+ if e, ok := err.(net.Error); ok && e.Temporary() {
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+ err = &netError{msg: e.Error(), timeout: e.Timeout()}
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+ }
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+ return err
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+}
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+
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+func isControl(frameType int) bool {
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+ return frameType == CloseMessage || frameType == PingMessage || frameType == PongMessage
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+}
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+
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+func isData(frameType int) bool {
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+ return frameType == TextMessage || frameType == BinaryMessage
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+}
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+
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+func maskBytes(key [4]byte, pos int, b []byte) int {
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+ for i := range b {
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+ b[i] ^= key[pos&3]
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+ pos++
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+ }
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+ return pos & 3
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+}
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+
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+func newMaskKey() [4]byte {
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+ n := rand.Uint32()
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+ return [4]byte{byte(n), byte(n >> 8), byte(n >> 16), byte(n >> 24)}
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+}
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+
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+// Conn represents a WebSocket connection.
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+type Conn struct {
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+ conn net.Conn
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+ isServer bool
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+ subprotocol string
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+
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+ // Write fields
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+ mu chan bool // used as mutex to protect write to conn and closeSent
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+ closeSent bool // true if close message was sent
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+
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+ // Message writer fields.
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+ writeErr error
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+ writeBuf []byte // frame is constructed in this buffer.
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+ writePos int // end of data in writeBuf.
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+ writeFrameType int // type of the current frame.
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+ writeSeq int // incremented to invalidate message writers.
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+ writeDeadline time.Time
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+ isWriting bool // for best-effort concurrent write detection
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+
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+ // Read fields
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+ readErr error
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+ br *bufio.Reader
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+ readRemaining int64 // bytes remaining in current frame.
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+ readFinal bool // true the current message has more frames.
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+ readSeq int // incremented to invalidate message readers.
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+ readLength int64 // Message size.
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+ readLimit int64 // Maximum message size.
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+ readMaskPos int
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+ readMaskKey [4]byte
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+ handlePong func(string) error
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+ handlePing func(string) error
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+ readErrCount int
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+}
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+
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+func newConn(conn net.Conn, isServer bool, readBufferSize, writeBufferSize int) *Conn {
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+ mu := make(chan bool, 1)
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+ mu <- true
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+
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+ if readBufferSize == 0 {
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+ readBufferSize = defaultReadBufferSize
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+ }
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+ if writeBufferSize == 0 {
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+ writeBufferSize = defaultWriteBufferSize
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+ }
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+
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+ c := &Conn{
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+ isServer: isServer,
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+ br: bufio.NewReaderSize(conn, readBufferSize),
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+ conn: conn,
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+ mu: mu,
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+ readFinal: true,
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+ writeBuf: make([]byte, writeBufferSize+maxFrameHeaderSize),
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+ writeFrameType: noFrame,
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+ writePos: maxFrameHeaderSize,
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+ }
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+ c.SetPingHandler(nil)
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+ c.SetPongHandler(nil)
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+ return c
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+}
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+
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+// Subprotocol returns the negotiated protocol for the connection.
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+func (c *Conn) Subprotocol() string {
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+ return c.subprotocol
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+}
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+
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+// Close closes the underlying network connection without sending or waiting for a close frame.
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+func (c *Conn) Close() error {
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+ return c.conn.Close()
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+}
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+
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+// LocalAddr returns the local network address.
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+func (c *Conn) LocalAddr() net.Addr {
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+ return c.conn.LocalAddr()
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+}
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+
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+// RemoteAddr returns the remote network address.
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+func (c *Conn) RemoteAddr() net.Addr {
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+ return c.conn.RemoteAddr()
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+}
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+
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+// Write methods
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+
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+func (c *Conn) write(frameType int, deadline time.Time, bufs ...[]byte) error {
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+ <-c.mu
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+ defer func() { c.mu <- true }()
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+
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+ if c.closeSent {
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+ return ErrCloseSent
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+ } else if frameType == CloseMessage {
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+ c.closeSent = true
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+ }
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+
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+ c.conn.SetWriteDeadline(deadline)
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+ for _, buf := range bufs {
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+ if len(buf) > 0 {
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+ n, err := c.conn.Write(buf)
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+ if n != len(buf) {
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+ // Close on partial write.
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+ c.conn.Close()
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+ }
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+ if err != nil {
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+ return err
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+ }
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+ }
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+ }
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+ return nil
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+}
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+
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+// WriteControl writes a control message with the given deadline. The allowed
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+// message types are CloseMessage, PingMessage and PongMessage.
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+func (c *Conn) WriteControl(messageType int, data []byte, deadline time.Time) error {
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+ if !isControl(messageType) {
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+ return errBadWriteOpCode
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+ }
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+ if len(data) > maxControlFramePayloadSize {
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+ return errInvalidControlFrame
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+ }
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+
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+ b0 := byte(messageType) | finalBit
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+ b1 := byte(len(data))
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+ if !c.isServer {
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+ b1 |= maskBit
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+ }
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+
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+ buf := make([]byte, 0, maxFrameHeaderSize+maxControlFramePayloadSize)
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+ buf = append(buf, b0, b1)
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+
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+ if c.isServer {
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+ buf = append(buf, data...)
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+ } else {
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+ key := newMaskKey()
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+ buf = append(buf, key[:]...)
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+ buf = append(buf, data...)
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+ maskBytes(key, 0, buf[6:])
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+ }
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+
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+ d := time.Hour * 1000
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+ if !deadline.IsZero() {
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+ d = deadline.Sub(time.Now())
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+ if d < 0 {
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+ return errWriteTimeout
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+ }
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+ }
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+
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+ timer := time.NewTimer(d)
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+ select {
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+ case <-c.mu:
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+ timer.Stop()
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+ case <-timer.C:
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+ return errWriteTimeout
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+ }
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+ defer func() { c.mu <- true }()
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+
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+ if c.closeSent {
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+ return ErrCloseSent
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+ } else if messageType == CloseMessage {
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+ c.closeSent = true
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+ }
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+
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+ c.conn.SetWriteDeadline(deadline)
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+ n, err := c.conn.Write(buf)
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+ if n != 0 && n != len(buf) {
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+ c.conn.Close()
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+ }
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+ return hideTempErr(err)
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+}
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+
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+// NextWriter returns a writer for the next message to send. The writer's
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+// Close method flushes the complete message to the network.
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+//
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+// There can be at most one open writer on a connection. NextWriter closes the
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+// previous writer if the application has not already done so.
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+func (c *Conn) NextWriter(messageType int) (io.WriteCloser, error) {
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+ if c.writeErr != nil {
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+ return nil, c.writeErr
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+ }
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+
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+ if c.writeFrameType != noFrame {
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+ if err := c.flushFrame(true, nil); err != nil {
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+ return nil, err
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+ }
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+ }
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+
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+ if !isControl(messageType) && !isData(messageType) {
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+ return nil, errBadWriteOpCode
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+ }
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+
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+ c.writeFrameType = messageType
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+ return messageWriter{c, c.writeSeq}, nil
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+}
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+
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+func (c *Conn) flushFrame(final bool, extra []byte) error {
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+ length := c.writePos - maxFrameHeaderSize + len(extra)
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+
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+ // Check for invalid control frames.
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+ if isControl(c.writeFrameType) &&
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+ (!final || length > maxControlFramePayloadSize) {
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+ c.writeSeq++
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+ c.writeFrameType = noFrame
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+ c.writePos = maxFrameHeaderSize
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+ return errInvalidControlFrame
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+ }
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+
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+ b0 := byte(c.writeFrameType)
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+ if final {
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+ b0 |= finalBit
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+ }
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+ b1 := byte(0)
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+ if !c.isServer {
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+ b1 |= maskBit
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+ }
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+
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+ // Assume that the frame starts at beginning of c.writeBuf.
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+ framePos := 0
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+ if c.isServer {
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+ // Adjust up if mask not included in the header.
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+ framePos = 4
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+ }
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+
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+ switch {
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+ case length >= 65536:
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+ c.writeBuf[framePos] = b0
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+ c.writeBuf[framePos+1] = b1 | 127
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+ binary.BigEndian.PutUint64(c.writeBuf[framePos+2:], uint64(length))
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+ case length > 125:
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+ framePos += 6
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+ c.writeBuf[framePos] = b0
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+ c.writeBuf[framePos+1] = b1 | 126
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+ binary.BigEndian.PutUint16(c.writeBuf[framePos+2:], uint16(length))
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+ default:
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+ framePos += 8
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+ c.writeBuf[framePos] = b0
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+ c.writeBuf[framePos+1] = b1 | byte(length)
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+ }
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+
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+ if !c.isServer {
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+ key := newMaskKey()
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+ copy(c.writeBuf[maxFrameHeaderSize-4:], key[:])
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+ maskBytes(key, 0, c.writeBuf[maxFrameHeaderSize:c.writePos])
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|
|
+ if len(extra) > 0 {
|
|
|
+ c.writeErr = errors.New("websocket: internal error, extra used in client mode")
|
|
|
+ return c.writeErr
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // Write the buffers to the connection with best-effort detection of
|
|
|
+ // concurrent writes. See the concurrency section in the package
|
|
|
+ // documentation for more info.
|
|
|
+
|
|
|
+ if c.isWriting {
|
|
|
+ panic("concurrent write to websocket connection")
|
|
|
+ }
|
|
|
+ c.isWriting = true
|
|
|
+
|
|
|
+ c.writeErr = c.write(c.writeFrameType, c.writeDeadline, c.writeBuf[framePos:c.writePos], extra)
|
|
|
+
|
|
|
+ if !c.isWriting {
|
|
|
+ panic("concurrent write to websocket connection")
|
|
|
+ }
|
|
|
+ c.isWriting = false
|
|
|
+
|
|
|
+ // Setup for next frame.
|
|
|
+ c.writePos = maxFrameHeaderSize
|
|
|
+ c.writeFrameType = continuationFrame
|
|
|
+ if final {
|
|
|
+ c.writeSeq++
|
|
|
+ c.writeFrameType = noFrame
|
|
|
+ }
|
|
|
+ return c.writeErr
|
|
|
+}
|
|
|
+
|
|
|
+type messageWriter struct {
|
|
|
+ c *Conn
|
|
|
+ seq int
|
|
|
+}
|
|
|
+
|
|
|
+func (w messageWriter) err() error {
|
|
|
+ c := w.c
|
|
|
+ if c.writeSeq != w.seq {
|
|
|
+ return errWriteClosed
|
|
|
+ }
|
|
|
+ if c.writeErr != nil {
|
|
|
+ return c.writeErr
|
|
|
+ }
|
|
|
+ return nil
|
|
|
+}
|
|
|
+
|
|
|
+func (w messageWriter) ncopy(max int) (int, error) {
|
|
|
+ n := len(w.c.writeBuf) - w.c.writePos
|
|
|
+ if n <= 0 {
|
|
|
+ if err := w.c.flushFrame(false, nil); err != nil {
|
|
|
+ return 0, err
|
|
|
+ }
|
|
|
+ n = len(w.c.writeBuf) - w.c.writePos
|
|
|
+ }
|
|
|
+ if n > max {
|
|
|
+ n = max
|
|
|
+ }
|
|
|
+ return n, nil
|
|
|
+}
|
|
|
+
|
|
|
+func (w messageWriter) write(final bool, p []byte) (int, error) {
|
|
|
+ if err := w.err(); err != nil {
|
|
|
+ return 0, err
|
|
|
+ }
|
|
|
+
|
|
|
+ if len(p) > 2*len(w.c.writeBuf) && w.c.isServer {
|
|
|
+ // Don't buffer large messages.
|
|
|
+ err := w.c.flushFrame(final, p)
|
|
|
+ if err != nil {
|
|
|
+ return 0, err
|
|
|
+ }
|
|
|
+ return len(p), nil
|
|
|
+ }
|
|
|
+
|
|
|
+ nn := len(p)
|
|
|
+ for len(p) > 0 {
|
|
|
+ n, err := w.ncopy(len(p))
|
|
|
+ if err != nil {
|
|
|
+ return 0, err
|
|
|
+ }
|
|
|
+ copy(w.c.writeBuf[w.c.writePos:], p[:n])
|
|
|
+ w.c.writePos += n
|
|
|
+ p = p[n:]
|
|
|
+ }
|
|
|
+ return nn, nil
|
|
|
+}
|
|
|
+
|
|
|
+func (w messageWriter) Write(p []byte) (int, error) {
|
|
|
+ return w.write(false, p)
|
|
|
+}
|
|
|
+
|
|
|
+func (w messageWriter) WriteString(p string) (int, error) {
|
|
|
+ if err := w.err(); err != nil {
|
|
|
+ return 0, err
|
|
|
+ }
|
|
|
+
|
|
|
+ nn := len(p)
|
|
|
+ for len(p) > 0 {
|
|
|
+ n, err := w.ncopy(len(p))
|
|
|
+ if err != nil {
|
|
|
+ return 0, err
|
|
|
+ }
|
|
|
+ copy(w.c.writeBuf[w.c.writePos:], p[:n])
|
|
|
+ w.c.writePos += n
|
|
|
+ p = p[n:]
|
|
|
+ }
|
|
|
+ return nn, nil
|
|
|
+}
|
|
|
+
|
|
|
+func (w messageWriter) ReadFrom(r io.Reader) (nn int64, err error) {
|
|
|
+ if err := w.err(); err != nil {
|
|
|
+ return 0, err
|
|
|
+ }
|
|
|
+ for {
|
|
|
+ if w.c.writePos == len(w.c.writeBuf) {
|
|
|
+ err = w.c.flushFrame(false, nil)
|
|
|
+ if err != nil {
|
|
|
+ break
|
|
|
+ }
|
|
|
+ }
|
|
|
+ var n int
|
|
|
+ n, err = r.Read(w.c.writeBuf[w.c.writePos:])
|
|
|
+ w.c.writePos += n
|
|
|
+ nn += int64(n)
|
|
|
+ if err != nil {
|
|
|
+ if err == io.EOF {
|
|
|
+ err = nil
|
|
|
+ }
|
|
|
+ break
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return nn, err
|
|
|
+}
|
|
|
+
|
|
|
+func (w messageWriter) Close() error {
|
|
|
+ if err := w.err(); err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ return w.c.flushFrame(true, nil)
|
|
|
+}
|
|
|
+
|
|
|
+// WriteMessage is a helper method for getting a writer using NextWriter,
|
|
|
+// writing the message and closing the writer.
|
|
|
+func (c *Conn) WriteMessage(messageType int, data []byte) error {
|
|
|
+ wr, err := c.NextWriter(messageType)
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ w := wr.(messageWriter)
|
|
|
+ if _, err := w.write(true, data); err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ if c.writeSeq == w.seq {
|
|
|
+ if err := c.flushFrame(true, nil); err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return nil
|
|
|
+}
|
|
|
+
|
|
|
+// SetWriteDeadline sets the write deadline on the underlying network
|
|
|
+// connection. After a write has timed out, the websocket state is corrupt and
|
|
|
+// all future writes will return an error. A zero value for t means writes will
|
|
|
+// not time out.
|
|
|
+func (c *Conn) SetWriteDeadline(t time.Time) error {
|
|
|
+ c.writeDeadline = t
|
|
|
+ return nil
|
|
|
+}
|
|
|
+
|
|
|
+// Read methods
|
|
|
+
|
|
|
+// readFull is like io.ReadFull except that io.EOF is never returned.
|
|
|
+func (c *Conn) readFull(p []byte) (err error) {
|
|
|
+ var n int
|
|
|
+ for n < len(p) && err == nil {
|
|
|
+ var nn int
|
|
|
+ nn, err = c.br.Read(p[n:])
|
|
|
+ n += nn
|
|
|
+ }
|
|
|
+ if n == len(p) {
|
|
|
+ err = nil
|
|
|
+ } else if err == io.EOF {
|
|
|
+ err = errUnexpectedEOF
|
|
|
+ }
|
|
|
+ return
|
|
|
+}
|
|
|
+
|
|
|
+func (c *Conn) advanceFrame() (int, error) {
|
|
|
+
|
|
|
+ // 1. Skip remainder of previous frame.
|
|
|
+
|
|
|
+ if c.readRemaining > 0 {
|
|
|
+ if _, err := io.CopyN(ioutil.Discard, c.br, c.readRemaining); err != nil {
|
|
|
+ return noFrame, err
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // 2. Read and parse first two bytes of frame header.
|
|
|
+
|
|
|
+ var b [8]byte
|
|
|
+ if err := c.readFull(b[:2]); err != nil {
|
|
|
+ return noFrame, err
|
|
|
+ }
|
|
|
+
|
|
|
+ final := b[0]&finalBit != 0
|
|
|
+ frameType := int(b[0] & 0xf)
|
|
|
+ reserved := int((b[0] >> 4) & 0x7)
|
|
|
+ mask := b[1]&maskBit != 0
|
|
|
+ c.readRemaining = int64(b[1] & 0x7f)
|
|
|
+
|
|
|
+ if reserved != 0 {
|
|
|
+ return noFrame, c.handleProtocolError("unexpected reserved bits " + strconv.Itoa(reserved))
|
|
|
+ }
|
|
|
+
|
|
|
+ switch frameType {
|
|
|
+ case CloseMessage, PingMessage, PongMessage:
|
|
|
+ if c.readRemaining > maxControlFramePayloadSize {
|
|
|
+ return noFrame, c.handleProtocolError("control frame length > 125")
|
|
|
+ }
|
|
|
+ if !final {
|
|
|
+ return noFrame, c.handleProtocolError("control frame not final")
|
|
|
+ }
|
|
|
+ case TextMessage, BinaryMessage:
|
|
|
+ if !c.readFinal {
|
|
|
+ return noFrame, c.handleProtocolError("message start before final message frame")
|
|
|
+ }
|
|
|
+ c.readFinal = final
|
|
|
+ case continuationFrame:
|
|
|
+ if c.readFinal {
|
|
|
+ return noFrame, c.handleProtocolError("continuation after final message frame")
|
|
|
+ }
|
|
|
+ c.readFinal = final
|
|
|
+ default:
|
|
|
+ return noFrame, c.handleProtocolError("unknown opcode " + strconv.Itoa(frameType))
|
|
|
+ }
|
|
|
+
|
|
|
+ // 3. Read and parse frame length.
|
|
|
+
|
|
|
+ switch c.readRemaining {
|
|
|
+ case 126:
|
|
|
+ if err := c.readFull(b[:2]); err != nil {
|
|
|
+ return noFrame, err
|
|
|
+ }
|
|
|
+ c.readRemaining = int64(binary.BigEndian.Uint16(b[:2]))
|
|
|
+ case 127:
|
|
|
+ if err := c.readFull(b[:8]); err != nil {
|
|
|
+ return noFrame, err
|
|
|
+ }
|
|
|
+ c.readRemaining = int64(binary.BigEndian.Uint64(b[:8]))
|
|
|
+ }
|
|
|
+
|
|
|
+ // 4. Handle frame masking.
|
|
|
+
|
|
|
+ if mask != c.isServer {
|
|
|
+ return noFrame, c.handleProtocolError("incorrect mask flag")
|
|
|
+ }
|
|
|
+
|
|
|
+ if mask {
|
|
|
+ c.readMaskPos = 0
|
|
|
+ if err := c.readFull(c.readMaskKey[:]); err != nil {
|
|
|
+ return noFrame, err
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // 5. For text and binary messages, enforce read limit and return.
|
|
|
+
|
|
|
+ if frameType == continuationFrame || frameType == TextMessage || frameType == BinaryMessage {
|
|
|
+
|
|
|
+ c.readLength += c.readRemaining
|
|
|
+ if c.readLimit > 0 && c.readLength > c.readLimit {
|
|
|
+ c.WriteControl(CloseMessage, FormatCloseMessage(CloseMessageTooBig, ""), time.Now().Add(writeWait))
|
|
|
+ return noFrame, ErrReadLimit
|
|
|
+ }
|
|
|
+
|
|
|
+ return frameType, nil
|
|
|
+ }
|
|
|
+
|
|
|
+ // 6. Read control frame payload.
|
|
|
+
|
|
|
+ var payload []byte
|
|
|
+ if c.readRemaining > 0 {
|
|
|
+ payload = make([]byte, c.readRemaining)
|
|
|
+ c.readRemaining = 0
|
|
|
+ if err := c.readFull(payload); err != nil {
|
|
|
+ return noFrame, err
|
|
|
+ }
|
|
|
+ if c.isServer {
|
|
|
+ maskBytes(c.readMaskKey, 0, payload)
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // 7. Process control frame payload.
|
|
|
+
|
|
|
+ switch frameType {
|
|
|
+ case PongMessage:
|
|
|
+ if err := c.handlePong(string(payload)); err != nil {
|
|
|
+ return noFrame, err
|
|
|
+ }
|
|
|
+ case PingMessage:
|
|
|
+ if err := c.handlePing(string(payload)); err != nil {
|
|
|
+ return noFrame, err
|
|
|
+ }
|
|
|
+ case CloseMessage:
|
|
|
+ echoMessage := []byte{}
|
|
|
+ closeCode := CloseNoStatusReceived
|
|
|
+ closeText := ""
|
|
|
+ if len(payload) >= 2 {
|
|
|
+ echoMessage = payload[:2]
|
|
|
+ closeCode = int(binary.BigEndian.Uint16(payload))
|
|
|
+ closeText = string(payload[2:])
|
|
|
+ }
|
|
|
+ c.WriteControl(CloseMessage, echoMessage, time.Now().Add(writeWait))
|
|
|
+ return noFrame, &CloseError{Code: closeCode, Text: closeText}
|
|
|
+ }
|
|
|
+
|
|
|
+ return frameType, nil
|
|
|
+}
|
|
|
+
|
|
|
+func (c *Conn) handleProtocolError(message string) error {
|
|
|
+ c.WriteControl(CloseMessage, FormatCloseMessage(CloseProtocolError, message), time.Now().Add(writeWait))
|
|
|
+ return errors.New("websocket: " + message)
|
|
|
+}
|
|
|
+
|
|
|
+// NextReader returns the next data message received from the peer. The
|
|
|
+// returned messageType is either TextMessage or BinaryMessage.
|
|
|
+//
|
|
|
+// There can be at most one open reader on a connection. NextReader discards
|
|
|
+// the previous message if the application has not already consumed it.
|
|
|
+//
|
|
|
+// Applications must break out of the application's read loop when this method
|
|
|
+// returns a non-nil error value. Errors returned from this method are
|
|
|
+// permanent. Once this method returns a non-nil error, all subsequent calls to
|
|
|
+// this method return the same error.
|
|
|
+func (c *Conn) NextReader() (messageType int, r io.Reader, err error) {
|
|
|
+
|
|
|
+ c.readSeq++
|
|
|
+ c.readLength = 0
|
|
|
+
|
|
|
+ for c.readErr == nil {
|
|
|
+ frameType, err := c.advanceFrame()
|
|
|
+ if err != nil {
|
|
|
+ c.readErr = hideTempErr(err)
|
|
|
+ break
|
|
|
+ }
|
|
|
+ if frameType == TextMessage || frameType == BinaryMessage {
|
|
|
+ return frameType, messageReader{c, c.readSeq}, nil
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // Applications that do handle the error returned from this method spin in
|
|
|
+ // tight loop on connection failure. To help application developers detect
|
|
|
+ // this error, panic on repeated reads to the failed connection.
|
|
|
+ c.readErrCount++
|
|
|
+ if c.readErrCount >= 1000 {
|
|
|
+ panic("repeated read on failed websocket connection")
|
|
|
+ }
|
|
|
+
|
|
|
+ return noFrame, nil, c.readErr
|
|
|
+}
|
|
|
+
|
|
|
+type messageReader struct {
|
|
|
+ c *Conn
|
|
|
+ seq int
|
|
|
+}
|
|
|
+
|
|
|
+func (r messageReader) Read(b []byte) (int, error) {
|
|
|
+
|
|
|
+ if r.seq != r.c.readSeq {
|
|
|
+ return 0, io.EOF
|
|
|
+ }
|
|
|
+
|
|
|
+ for r.c.readErr == nil {
|
|
|
+
|
|
|
+ if r.c.readRemaining > 0 {
|
|
|
+ if int64(len(b)) > r.c.readRemaining {
|
|
|
+ b = b[:r.c.readRemaining]
|
|
|
+ }
|
|
|
+ n, err := r.c.br.Read(b)
|
|
|
+ r.c.readErr = hideTempErr(err)
|
|
|
+ if r.c.isServer {
|
|
|
+ r.c.readMaskPos = maskBytes(r.c.readMaskKey, r.c.readMaskPos, b[:n])
|
|
|
+ }
|
|
|
+ r.c.readRemaining -= int64(n)
|
|
|
+ return n, r.c.readErr
|
|
|
+ }
|
|
|
+
|
|
|
+ if r.c.readFinal {
|
|
|
+ r.c.readSeq++
|
|
|
+ return 0, io.EOF
|
|
|
+ }
|
|
|
+
|
|
|
+ frameType, err := r.c.advanceFrame()
|
|
|
+ switch {
|
|
|
+ case err != nil:
|
|
|
+ r.c.readErr = hideTempErr(err)
|
|
|
+ case frameType == TextMessage || frameType == BinaryMessage:
|
|
|
+ r.c.readErr = errors.New("websocket: internal error, unexpected text or binary in Reader")
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ err := r.c.readErr
|
|
|
+ if err == io.EOF && r.seq == r.c.readSeq {
|
|
|
+ err = errUnexpectedEOF
|
|
|
+ }
|
|
|
+ return 0, err
|
|
|
+}
|
|
|
+
|
|
|
+// ReadMessage is a helper method for getting a reader using NextReader and
|
|
|
+// reading from that reader to a buffer.
|
|
|
+func (c *Conn) ReadMessage() (messageType int, p []byte, err error) {
|
|
|
+ var r io.Reader
|
|
|
+ messageType, r, err = c.NextReader()
|
|
|
+ if err != nil {
|
|
|
+ return messageType, nil, err
|
|
|
+ }
|
|
|
+ p, err = ioutil.ReadAll(r)
|
|
|
+ return messageType, p, err
|
|
|
+}
|
|
|
+
|
|
|
+// SetReadDeadline sets the read deadline on the underlying network connection.
|
|
|
+// After a read has timed out, the websocket connection state is corrupt and
|
|
|
+// all future reads will return an error. A zero value for t means reads will
|
|
|
+// not time out.
|
|
|
+func (c *Conn) SetReadDeadline(t time.Time) error {
|
|
|
+ return c.conn.SetReadDeadline(t)
|
|
|
+}
|
|
|
+
|
|
|
+// SetReadLimit sets the maximum size for a message read from the peer. If a
|
|
|
+// message exceeds the limit, the connection sends a close frame to the peer
|
|
|
+// and returns ErrReadLimit to the application.
|
|
|
+func (c *Conn) SetReadLimit(limit int64) {
|
|
|
+ c.readLimit = limit
|
|
|
+}
|
|
|
+
|
|
|
+// SetPingHandler sets the handler for ping messages received from the peer.
|
|
|
+// The appData argument to h is the PING frame application data. The default
|
|
|
+// ping handler sends a pong to the peer.
|
|
|
+func (c *Conn) SetPingHandler(h func(appData string) error) {
|
|
|
+ if h == nil {
|
|
|
+ h = func(message string) error {
|
|
|
+ err := c.WriteControl(PongMessage, []byte(message), time.Now().Add(writeWait))
|
|
|
+ if err == ErrCloseSent {
|
|
|
+ return nil
|
|
|
+ } else if e, ok := err.(net.Error); ok && e.Temporary() {
|
|
|
+ return nil
|
|
|
+ }
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ }
|
|
|
+ c.handlePing = h
|
|
|
+}
|
|
|
+
|
|
|
+// SetPongHandler sets the handler for pong messages received from the peer.
|
|
|
+// The appData argument to h is the PONG frame application data. The default
|
|
|
+// pong handler does nothing.
|
|
|
+func (c *Conn) SetPongHandler(h func(appData string) error) {
|
|
|
+ if h == nil {
|
|
|
+ h = func(string) error { return nil }
|
|
|
+ }
|
|
|
+ c.handlePong = h
|
|
|
+}
|
|
|
+
|
|
|
+// UnderlyingConn returns the internal net.Conn. This can be used to further
|
|
|
+// modifications to connection specific flags.
|
|
|
+func (c *Conn) UnderlyingConn() net.Conn {
|
|
|
+ return c.conn
|
|
|
+}
|
|
|
+
|
|
|
+// FormatCloseMessage formats closeCode and text as a WebSocket close message.
|
|
|
+func FormatCloseMessage(closeCode int, text string) []byte {
|
|
|
+ buf := make([]byte, 2+len(text))
|
|
|
+ binary.BigEndian.PutUint16(buf, uint16(closeCode))
|
|
|
+ copy(buf[2:], text)
|
|
|
+ return buf
|
|
|
+}
|
Torkel Ödegaard