Method handleControl

read.go:290–367

(ctx context.Context, h header)

}

func (c *Conn) handleControl(ctx context.Context, h header) (err error) {
	if h.payloadLength < 0 || h.payloadLength > maxControlPayload {
		err := fmt.Errorf("received control frame payload with invalid length: %d", h.payloadLength)
		c.writeError(StatusProtocolError, err)
		return err
	}

	if !h.fin {
		err := errors.New("received fragmented control frame")
		c.writeError(StatusProtocolError, err)
		return err
	}

	ctx, cancel := context.WithTimeout(ctx, time.Second*5)
	defer cancel()

	b := c.readControlBuf[:h.payloadLength]
	_, err = c.readFramePayload(ctx, b)
	if err != nil {
		return err
	}

	if h.masked {
		mask(b, h.maskKey)
	}

	switch h.opcode {
	case opPing:
		if c.onPingReceived != nil {
			if !c.onPingReceived(ctx, b) {
				return nil
			}
		}
		return c.writeControl(ctx, opPong, b)
	case opPong:
		if c.onPongReceived != nil {
			c.onPongReceived(ctx, b)
		}
		c.activePingsMu.Lock()
		pong, ok := c.activePings[string(b)]
		c.activePingsMu.Unlock()
		if ok {
			select {
			case pong <- struct{}{}:
			default:
			}
		}
		return nil
	}

	// opClose

	ce, err := parseClosePayload(b)
	if err != nil {
		err = fmt.Errorf("received invalid close payload: %w", err)
		c.writeError(StatusProtocolError, err)
		return err
	}