From fa7b23f339a06b573e5e46c2f9cf2c028da17c3a Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Tue, 4 Sep 2018 15:56:02 -0700
Subject: [PATCH] Catch RTP FEC queue corruption earlier

---
 src/RtpFecQueue.c | 11 ++++++-----
 src/RtpFecQueue.h |  1 -
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/RtpFecQueue.c b/src/RtpFecQueue.c
index 11d19df..5273780 100644
--- a/src/RtpFecQueue.c
+++ b/src/RtpFecQueue.c
@@ -5,7 +5,6 @@
 void RtpfInitializeQueue(PRTP_FEC_QUEUE queue) {
     reed_solomon_init();
     memset(queue, 0, sizeof(*queue));
-    queue->nextRtpSequenceNumber = UINT16_MAX;
     
     queue->currentFrameNumber = UINT16_MAX;
 }
@@ -28,7 +27,7 @@ void RtpfCleanupQueue(PRTP_FEC_QUEUE queue) {
 static int queuePacket(PRTP_FEC_QUEUE queue, PRTPFEC_QUEUE_ENTRY newEntry, int head, PRTP_PACKET packet, int length, int isParity) {
     PRTPFEC_QUEUE_ENTRY entry;
     
-    LC_ASSERT(!isBefore16(packet->sequenceNumber, queue->nextRtpSequenceNumber));
+    LC_ASSERT(!isBefore16(packet->sequenceNumber, queue->bufferLowestSequenceNumber));
 
     // Don't queue duplicates either
     entry = queue->bufferHead;
@@ -212,8 +211,8 @@ static void removeEntry(PRTP_FEC_QUEUE queue, PRTPFEC_QUEUE_ENTRY entry) {
 }
 
 int RtpfAddPacket(PRTP_FEC_QUEUE queue, PRTP_PACKET packet, int length, PRTPFEC_QUEUE_ENTRY packetEntry) {
-    if (isBefore16(packet->sequenceNumber, queue->nextRtpSequenceNumber)) {
-        // Reject packets behind our current sequence number
+    if (isBefore16(packet->sequenceNumber, queue->bufferLowestSequenceNumber)) {
+        // Reject packets behind our current buffer window
         return RTPF_RET_REJECTED;
     }
 
@@ -241,7 +240,6 @@ int RtpfAddPacket(PRTP_FEC_QUEUE queue, PRTP_PACKET packet, int length, PRTPFEC_
         }
         
         queue->currentFrameNumber = nvPacket->frameIndex;
-        queue->nextRtpSequenceNumber = queue->bufferHighestSequenceNumber;
         
         // Discard any unsubmitted buffers from the previous frame
         while (queue->bufferHead != NULL) {
@@ -263,6 +261,9 @@ int RtpfAddPacket(PRTP_FEC_QUEUE queue, PRTP_PACKET packet, int length, PRTPFEC_
     } else if (isBefore16(queue->bufferHighestSequenceNumber, packet->sequenceNumber)) {
         queue->bufferHighestSequenceNumber = packet->sequenceNumber;
     }
+
+    LC_ASSERT(((nvPacket->fecInfo & 0xFF0) >> 4) == queue->fecPercentage);
+    LC_ASSERT(((nvPacket->fecInfo & 0xFFF00000) >> 20) / 4 == queue->bufferDataPackets);
     
     if (!queuePacket(queue, packetEntry, 0, packet, length, !isBefore16(packet->sequenceNumber, queue->bufferFirstParitySequenceNumber))) {
         return RTPF_RET_REJECTED;
diff --git a/src/RtpFecQueue.h b/src/RtpFecQueue.h
index a13a41e..dbe53cf 100644
--- a/src/RtpFecQueue.h
+++ b/src/RtpFecQueue.h
@@ -28,7 +28,6 @@ typedef struct _RTP_FEC_QUEUE {
     int fecPercentage;
 
     int currentFrameNumber;
-    unsigned int nextRtpSequenceNumber;
 } RTP_FEC_QUEUE, *PRTP_FEC_QUEUE;
 
 #define RTPF_RET_QUEUED_NOTHING_READY 0