mirror of
https://github.com/mollyim/webrtc.git
synced 2025-05-14 06:10:40 +01:00
0b0afaa81a
The SCTP RFCs aren't very strict in specifying when a chunk or parameter is invalid, so most chunks and/or parameters must be accepted but they may need some cleaning to avoid a lot of error handling deeper in the chunk handling code. Bug: webrtc:12614 Change-Id: I723f08cbdc26e1a1b78463b6137340e638089037 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/214966 Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Victor Boivie <boivie@webrtc.org> Cr-Commit-Position: refs/heads/master@{#33788}
90 lines
2.9 KiB
C++
90 lines
2.9 KiB
C++
/*
|
|
* Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license
|
|
* that can be found in the LICENSE file in the root of the source
|
|
* tree. An additional intellectual property rights grant can be found
|
|
* in the file PATENTS. All contributing project authors may
|
|
* be found in the AUTHORS file in the root of the source tree.
|
|
*/
|
|
#include "net/dcsctp/packet/chunk_validators.h"
|
|
|
|
#include <algorithm>
|
|
#include <utility>
|
|
#include <vector>
|
|
|
|
#include "net/dcsctp/packet/chunk/sack_chunk.h"
|
|
#include "rtc_base/logging.h"
|
|
|
|
namespace dcsctp {
|
|
|
|
SackChunk ChunkValidators::Clean(SackChunk&& sack) {
|
|
if (Validate(sack)) {
|
|
return std::move(sack);
|
|
}
|
|
|
|
RTC_DLOG(LS_WARNING) << "Received SACK is malformed; cleaning it";
|
|
|
|
std::vector<SackChunk::GapAckBlock> gap_ack_blocks;
|
|
gap_ack_blocks.reserve(sack.gap_ack_blocks().size());
|
|
|
|
// First: Only keep blocks that are sane
|
|
for (const SackChunk::GapAckBlock& gap_ack_block : sack.gap_ack_blocks()) {
|
|
if (gap_ack_block.end > gap_ack_block.start) {
|
|
gap_ack_blocks.emplace_back(gap_ack_block);
|
|
}
|
|
}
|
|
|
|
// Not more than at most one remaining? Exit early.
|
|
if (gap_ack_blocks.size() <= 1) {
|
|
return SackChunk(sack.cumulative_tsn_ack(), sack.a_rwnd(),
|
|
std::move(gap_ack_blocks),
|
|
std::vector<TSN>(sack.duplicate_tsns().begin(),
|
|
sack.duplicate_tsns().end()));
|
|
}
|
|
|
|
// Sort the intervals by their start value, to aid in the merging below.
|
|
absl::c_sort(gap_ack_blocks, [&](const SackChunk::GapAckBlock& a,
|
|
const SackChunk::GapAckBlock& b) {
|
|
return a.start < b.start;
|
|
});
|
|
|
|
// Merge overlapping ranges.
|
|
std::vector<SackChunk::GapAckBlock> merged;
|
|
merged.reserve(gap_ack_blocks.size());
|
|
merged.push_back(gap_ack_blocks[0]);
|
|
|
|
for (size_t i = 1; i < gap_ack_blocks.size(); ++i) {
|
|
if (merged.back().end + 1 >= gap_ack_blocks[i].start) {
|
|
merged.back().end = std::max(merged.back().end, gap_ack_blocks[i].end);
|
|
} else {
|
|
merged.push_back(gap_ack_blocks[i]);
|
|
}
|
|
}
|
|
|
|
return SackChunk(sack.cumulative_tsn_ack(), sack.a_rwnd(), std::move(merged),
|
|
std::vector<TSN>(sack.duplicate_tsns().begin(),
|
|
sack.duplicate_tsns().end()));
|
|
}
|
|
|
|
bool ChunkValidators::Validate(const SackChunk& sack) {
|
|
if (sack.gap_ack_blocks().empty()) {
|
|
return true;
|
|
}
|
|
|
|
// Ensure that gap-ack-blocks are sorted, has an "end" that is not before
|
|
// "start" and are non-overlapping and non-adjacent.
|
|
uint16_t prev_end = 0;
|
|
for (const SackChunk::GapAckBlock& gap_ack_block : sack.gap_ack_blocks()) {
|
|
if (gap_ack_block.end < gap_ack_block.start) {
|
|
return false;
|
|
}
|
|
if (gap_ack_block.start <= (prev_end + 1)) {
|
|
return false;
|
|
}
|
|
prev_end = gap_ack_block.end;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
} // namespace dcsctp
|