skip invalid bytes in connection read (#653)

bluenviron · Dec 10, 2024 · 51f00fa · 51f00fa
1 parent db334b3
commit 51f00fa
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Showing 2 changed files with 55 additions and 13 deletions.
diff --git a/pkg/conn/conn.go b/pkg/conn/conn.go
@@ -31,20 +31,36 @@ func NewConn(rw io.ReadWriter) *Conn {
 
 // Read reads a Request, a Response or an Interleaved frame.
 func (c *Conn) Read() (interface{}, error) {
-	byts, err := c.br.Peek(2)
-	if err != nil {
-		return nil, err
+	for {
+		byts, err := c.br.Peek(2)
+		if err != nil {
+			return nil, err
+		}
+
+		if byts[0] == base.InterleavedFrameMagicByte {
+			return c.ReadInterleavedFrame()
+		}
+
+		if byts[0] == 'R' && byts[1] == 'T' {
+			return c.ReadResponse()
+		}
+
+		if (byts[0] == 'A' && byts[1] == 'N') ||
+			(byts[0] == 'D' && byts[1] == 'E') ||
+			(byts[0] == 'G' && byts[1] == 'E') ||
+			(byts[0] == 'O' && byts[1] == 'P') ||
+			(byts[0] == 'P' && byts[1] == 'A') ||
+			(byts[0] == 'P' && byts[1] == 'L') ||
+			(byts[0] == 'R' && byts[1] == 'E') ||
+			(byts[0] == 'S' && byts[1] == 'E') ||
+			(byts[0] == 'T' && byts[1] == 'E') {
+			return c.ReadRequest()
+		}
+
+		if _, err := c.br.Discard(1); err != nil {
+			return nil, err
+		}
 	}
-
-	if byts[0] == base.InterleavedFrameMagicByte {
-		return c.ReadInterleavedFrame()
-	}
-
-	if byts[0] == 'R' && byts[1] == 'T' {
-		return c.ReadResponse()
-	}
-
-	return c.ReadRequest()
 }
 
 // ReadRequest reads a Request.

diff --git a/pkg/conn/conn_test.go b/pkg/conn/conn_test.go
@@ -76,6 +76,32 @@ func TestRead(t *testing.T) {
 	}
 }
 
+func TestReadConsecutiveFrameMagicBytes(t *testing.T) {
+	buf := bytes.NewBuffer([]byte{
+		// interleaved frame
+		0x24, 0x6, 0x0, 0x4, 0x1, 0x2, 0x3, 0x4,
+		// random bytes
+		0x00, 0x00, 0x00,
+		// another interleaved frame
+		0x24, 0x6, 0x0, 0x4, 0x1, 0x2, 0x3, 0x4,
+	})
+	conn := NewConn(buf)
+	dec1, err := conn.Read()
+	require.NoError(t, err)
+	require.Equal(t,
+		&base.InterleavedFrame{
+			Channel: 6,
+			Payload: []byte{0x01, 0x02, 0x03, 0x04},
+		}, dec1)
+	dec2, err := conn.Read()
+	require.NoError(t, err)
+	require.Equal(t,
+		&base.InterleavedFrame{
+			Channel: 6,
+			Payload: []byte{0x01, 0x02, 0x03, 0x04},
+		}, dec2)
+}
+
 func TestReadError(t *testing.T) {
 	var buf bytes.Buffer
 	conn := NewConn(&buf)