Function TestReadLimit

conn_test.go:465–553

(t *testing.T)

}

func TestReadLimit(t *testing.T) {
	t.Run("Test ReadLimit is enforced", func(t *testing.T) {
		const readLimit = 512
		message := make([]byte, readLimit+1)

		var b1, b2 bytes.Buffer
		wc := newConn(&fakeNetConn{Writer: &b1}, false, 1024, readLimit-2, nil, nil, nil)
		rc := newTestConn(&b1, &b2, true)
		rc.SetReadLimit(readLimit)

		// Send message at the limit with interleaved pong.
		w, _ := wc.NextWriter(BinaryMessage)
		w.Write(message[:readLimit-1])
		wc.WriteControl(PongMessage, []byte("this is a pong"), time.Now().Add(10*time.Second))
		w.Write(message[:1])
		w.Close()

		// Send message larger than the limit.
		wc.WriteMessage(BinaryMessage, message[:readLimit+1])

		op, _, err := rc.NextReader()
		if op != BinaryMessage || err != nil {
			t.Fatalf("1: NextReader() returned %d, %v", op, err)
		}
		op, r, err := rc.NextReader()
		if op != BinaryMessage || err != nil {
			t.Fatalf("2: NextReader() returned %d, %v", op, err)
		}
		_, err = io.Copy(ioutil.Discard, r)
		if err != ErrReadLimit {
			t.Fatalf("io.Copy() returned %v", err)
		}
	})

	t.Run("Test that ReadLimit cannot be overflowed", func(t *testing.T) {
		const readLimit = 1

		var b1, b2 bytes.Buffer
		rc := newTestConn(&b1, &b2, true)
		rc.SetReadLimit(readLimit)

		// First, send a non-final binary message
		b1.Write([]byte("\x02\x81"))

		// Mask key
		b1.Write([]byte("\x00\x00\x00\x00"))

		// First payload
		b1.Write([]byte("A"))

		// Next, send a negative-length, non-final continuation frame
		b1.Write([]byte("\x00\xFF\x80\x00\x00\x00\x00\x00\x00\x00"))

		// Mask key
		b1.Write([]byte("\x00\x00\x00\x00"))

		// Next, send a too long, final continuation frame
		b1.Write([]byte("\x80\xFF\x00\x00\x00\x00\x00\x00\x00\x05"))