User Initiated Abort (cause code: 12) not handled

[enobufs]

Your environment.

• Version: pion/sctp@v1.8.2
• Browser: Chrome Version 100.0.4896.127 (Official Build) (x86_64)

What did you do?

Performed close() on a peer connection, from Chrome to pion, after sending a set of data over a data channel.

What did you expect?

No warning in the log.

What happened?

This line was seen on the pion side:

sctp WARNING: 2022/05/01 09:29:38 [0xc00016e000] unable to parse SCTP packet failed build Abort Chunk: BuildErrorCause does not handle: User Initiated Abort

I did not see this warning when the teardown was initiated by Firefox.

Current pion/sctp does not parse User Initiated Abort (cause code: 12). By parsing, we can retrieve "Upper Layer Abort Reason", which may help troubleshooting.

Related info:

• Need Clarification on User initiated Abort

[enobufs]

@jeremija has already implemented this in #182. Let me follow up on the PR.

[enobufs]

FYI: From my quick investigation, User-Initiated Abort Reason field Chrome sent contained "Close called".

   This error cause MAY be included in ABORT chunks that are sent
   because of an upper-layer request.  The upper layer can specify an
   Upper Layer Abort Reason that is transported by SCTP transparently
   and MAY be delivered to the upper-layer protocol at the peer.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |         Cause Code=12         |      Cause Length=Variable    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       /                    Upper Layer Abort Reason                   /
       \                                                               \
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

[enobufs]

Fixed by #183