commit 568bc23208441f4a7f302a26cce6061f9beee463
author Victor Boivie <boivie@webrtc.org> Sun Mar 20 18:59:03 2022
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Mar 24 10:39:03 2022
tree d8bd54652173ad383ba5a20f73877a177854958d
parent 0c28820dcde47398f98a5152694f68f6ae221960

dcsctp: Don't reassemble already received chunks

This is a solution to some problems that have been found locally when
running the fuzzer for a long time. The fuzzer keeps on fuzzing, and has
found a way to trigger a consistency check to fail when a client
intentionally sends different messages - unordered and ordered - using
the same TSNs. As the reassembly queue has different handling of ordered
and unordered chunks due to how they are reassembled, it will not notice
if it receives two different chunks with the same TSN. They will both go
to their respective reassembly streams, as those are separate by design.

The data tracker - which keeps track of all received DATA chunks as it
needs to generate SACKs, has a global understanding of all received
chunks. By having it indicate if this is a duplicate received chunk, the
socket can avoid forwarding both chunks to the reassembly queue; only
one chunk will get there.

Bug: None
Change-Id: I602a8552a9a4c853684fcf105309ec3d8073f2c2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/256110
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36316}