fix Transport layer CC unmarshal bug for empty feedbacks

Author: rainliu

README.md

@@ -26,5 +26,5 @@
  </a>
 </p>
 <p align="center">
- A pure Rust implementation of RTCP. Rewrite <a href="https://github.com/pion/rtcp/releases/tag/v1.2.8">Pion</a> RTCP in Rust
+ A pure Rust implementation of RTCP. Rewrite <a href="https://github.com/pion/rtcp/releases/tag/v1.2.9">Pion</a> RTCP in Rust
 </p>

src/packet.rs

@@ -238,6 +238,34 @@ mod test {
             assert!(false, "want error");
         }
 
+        Ok(())
+    }
+    #[test]
+    fn test_packet_unmarshal_firefox() -> Result<()> {
+        // issue report from https://github.com/webrtc-rs/srtp/issues/7
+        let tests = vec![
+            Bytes::from_static(&[
+                143, 205, 0, 6, 65, 227, 184, 49, 118, 243, 78, 96, 42, 63, 0, 5, 12, 162, 166, 0,
+                32, 5, 200, 4, 0, 4, 0, 0,
+            ]),
+            /*Bytes::from_static(&[
+                143, 205, 0, 9, 65, 227, 184, 49, 118, 243, 78, 96, 42, 68, 0, 17, 12, 162, 167, 1,
+                32, 17, 88, 0, 4, 0, 4, 8, 108, 0, 4, 0, 4, 12, 0, 4, 0, 4, 4, 0,
+            ]),
+            Bytes::from_static(&[
+                143, 205, 0, 8, 65, 227, 184, 49, 118, 243, 78, 96, 42, 91, 0, 12, 12, 162, 168, 3,
+                32, 12, 220, 4, 0, 4, 0, 8, 128, 4, 0, 4, 0, 8, 0, 0,
+            ]),
+            Bytes::from_static(&[
+                143, 205, 0, 7, 65, 227, 184, 49, 118, 243, 78, 96, 42, 103, 0, 8, 12, 162, 169, 4,
+                32, 8, 232, 4, 0, 4, 0, 4, 4, 0, 0, 0,
+            ]),*/
+        ];
+
+        for mut test in tests {
+            unmarshal(&mut test)?;
+        }
+
         Ok(())
     }
 }

src/transport_feedbacks/transport_layer_cc/mod.rs

@@ -590,7 +590,7 @@ impl Unmarshal for TransportLayerCc {
         // header's length + payload's length
         let total_length = 4 * (h.length + 1) as usize;
 
-        if total_length <= HEADER_LENGTH + PACKET_CHUNK_OFFSET {
+        if total_length < HEADER_LENGTH + PACKET_CHUNK_OFFSET {
             return Err(Error::PacketTooShort.into());
         }
 

src/transport_feedbacks/transport_layer_cc/transport_layer_cc_test.rs

@@ -583,6 +583,23 @@ fn test_transport_layer_cc_unmarshal() -> Result<()> {
                 ],
             },
         ),
+        (
+            "example3",
+            Bytes::from_static(&[
+                0x8f, 0xcd, 0x0, 0x4, 0x9a, 0xcb, 0x4, 0x42, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+                0x0, 0x0, 0x0, 0x0, 0x0,
+            ]),
+            TransportLayerCc {
+                sender_ssrc: 2596996162,
+                media_ssrc: 0,
+                base_sequence_number: 0,
+                packet_status_count: 0,
+                reference_time: 0,
+                fb_pkt_count: 0,
+                packet_chunks: vec![],
+                recv_deltas: vec![],
+            },
+        ),
     ];
 
     for (name, mut data, want) in tests {