Avoid generating malformed padding packets (#1816)

lodoyun · web-flow · commit f9fca4e0cd04 · 2022-05-25T10:31:33.000+02:00
diff --git a/erizo/src/erizo/rtp/RtpPaddingGeneratorHandler.cpp b/erizo/src/erizo/rtp/RtpPaddingGeneratorHandler.cpp
@@ -165,7 +165,12 @@ void RtpPaddingGeneratorHandler::recalculatePaddingRate(uint64_t target_padding_
   }
   uint64_t bytes_per_marker = target_padding_bitrate / (marker_rate * 8);
   number_of_full_padding_packets_ = bytes_per_marker / (kMaxPaddingSize + rtp_header_length_);
-  last_padding_packet_size_ = bytes_per_marker % (kMaxPaddingSize + rtp_header_length_) - rtp_header_length_;
+  int last_payload_size =
+    static_cast<int>(bytes_per_marker % (kMaxPaddingSize + rtp_header_length_) - rtp_header_length_);
+  int clamped_payload_size =
+    std::clamp(last_payload_size,
+      0, static_cast<int>(kMaxPaddingSize));
+  last_padding_packet_size_ = static_cast<uint8_t>(clamped_payload_size);
 }
 
 uint64_t RtpPaddingGeneratorHandler::getBurstSize() {

Original file line number	Diff line number	Diff line change
`@@ -165,7 +165,12 @@ void RtpPaddingGeneratorHandler::recalculatePaddingRate(uint64_t target_padding_`
`165`	`165`	`}`
`166`	`166`	`uint64_t bytes_per_marker = target_padding_bitrate / (marker_rate * 8);`
`167`	`167`	`number_of_full_padding_packets_ = bytes_per_marker / (kMaxPaddingSize + rtp_header_length_);`
`168`		`- last_padding_packet_size_ = bytes_per_marker % (kMaxPaddingSize + rtp_header_length_) - rtp_header_length_;`
	`168`	`+ int last_payload_size =`
	`169`	`+ static_cast<int>(bytes_per_marker % (kMaxPaddingSize + rtp_header_length_) - rtp_header_length_);`
	`170`	`+ int clamped_payload_size =`
	`171`	`+ std::clamp(last_payload_size,`
	`172`	`+ 0, static_cast<int>(kMaxPaddingSize));`
	`173`	`+ last_padding_packet_size_ = static_cast<uint8_t>(clamped_payload_size);`
`169`	`174`	`}`
`170`	`175`
`171`	`176`	`uint64_t RtpPaddingGeneratorHandler::getBurstSize() {`