From: Julian Cordes <julian.cordes@gmail.com>
Date: Tue, 17 Jan 2017 13:06:48 +0000
Subject: Issues on handshake with PR-SCTP
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When one side of an association does not support PR-SCTP and does not
announce the support with the FORWARD-TSN-Supported- Parameter in the
INIT-Chunk or INIT-ACK chunk during the handshake there are two issues:

If the peer does not include the FORWARD-TSN-Supported-Parameter in the
INIT-Chunk and later sends an FORWARD-TSN-Chunk, then the linux kernel
does not respond with an ERROR-Chunk like defined in https://tools.ietf.org/html/rfc3758#section-3.3.1.
It instead silently discards the FORWARD-TSN-Chunk.

Testscript available at:
https://github.com/nplab/PR_SCTP_Testsuite/blob/master/forward-tsn/handshake-with-forward-tsn/handshake-with-forward-tsn-4.pkt

If the peer does not include the FORWARD-TSN-Supported-Parameter in the
INIT-ACK-Chunk but sends later an FORWARD-TSN-Chunk, then the behaviour
is different. The Forward-TSN-Chunk is processed and an SACK-Chunk is sent
by the linux kernel. This should also be an ERROR-Chunk, because the peer
has not announced support for PR-SCTP.

Testscript available at:
https://github.com/nplab/PR_SCTP_Testsuite/blob/master/forward-tsn/handshake-with-forward-tsn/handshake-with-forward-tsn-5.pkt

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