Fix a downstream test failure.
In rare case the packets number may loop around and in the same FEC-protected group the packet sequence number became out of order.
Bug: chromium:850493
Change-Id: Ice82aafd537e0edc1dbdb8b934e11e7c42a4cf60
Reviewed-on: https://webrtc-review.googlesource.com/82802
Commit-Queue: Ying Wang <yinwa@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23633}diff --git a/modules/rtp_rtcp/source/forward_error_correction_internal.cc b/modules/rtp_rtcp/source/forward_error_correction_internal.cc
index 7336331..7e5fd91 100644
--- a/modules/rtp_rtcp/source/forward_error_correction_internal.cc
+++ b/modules/rtp_rtcp/source/forward_error_correction_internal.cc
@@ -498,6 +498,8 @@
int num_fec_packets,
int new_bit_index,
int old_bit_index) {
+ RTC_CHECK_LT(new_bit_index, 8 * new_mask_bytes);
+
// Copy column from the old mask to the beginning of the new mask and shift it
// out from the old mask.
for (uint16_t row = 0; row < num_fec_packets; ++row) {
diff --git a/test/fuzzers/ulpfec_generator_fuzzer.cc b/test/fuzzers/ulpfec_generator_fuzzer.cc
index 995bf29..ba9a53a 100644
--- a/test/fuzzers/ulpfec_generator_fuzzer.cc
+++ b/test/fuzzers/ulpfec_generator_fuzzer.cc
@@ -31,7 +31,7 @@
data[i++] % 128, static_cast<int>(data[i++] % 10), kFecMaskBursty};
generator.SetFecParameters(params);
uint16_t seq_num = data[i++];
-
+ uint16_t prev_seq_num = 0;
while (i + 3 < size) {
size_t rtp_header_length = data[i++] % 10 + 12;
size_t payload_size = data[i++] % 10;
@@ -40,13 +40,20 @@
std::unique_ptr<uint8_t[]> packet(
new uint8_t[payload_size + rtp_header_length]);
memcpy(packet.get(), &data[i], payload_size + rtp_header_length);
+
+ // Make sure sequence numbers are increasing.
ByteWriter<uint16_t>::WriteBigEndian(&packet[2], seq_num++);
i += payload_size + rtp_header_length;
- // Make sure sequence numbers are increasing.
const bool protect = data[i++] % 2 == 1;
- if (protect) {
+
+ // Check the sequence numbers are monotonic. In rare case the packets number
+ // may loop around and in the same FEC-protected group the packet sequence
+ // number became out of order.
+ if (protect && static_cast<uint16_t>(seq_num - prev_seq_num) <
+ kUlpfecMaxMediaPackets) {
generator.AddRtpPacketAndGenerateFec(packet.get(), payload_size,
rtp_header_length);
+ prev_seq_num = seq_num;
}
const size_t num_fec_packets = generator.NumAvailableFecPackets();
if (num_fec_packets > 0) {
