tree cb5f57a90a261b7443d202d96cf5725dbba371c8
parent 33ce828131ca6655b48bd2070dadd80f816dfe0d
author Vlad Yasevich <vladislav.yasevich@hp.com> 1252102859 -0400
committer Vlad Yasevich <vladislav.yasevich@hp.com> 1252102859 -0400

sctp: drop a_rwnd to 0 when receive buffer overflows.

SCTP has a problem that when small chunks are used, it is possible
to exhaust the receiver buffer without fully closing receive window.
This happens due to all overhead that we have account for with small
messages.  To fix this, when receive buffer is exceeded, we'll drop
the window to 0 and save the 'drop' portion.  When application starts
reading data and freeing up recevie buffer space, we'll wait until
we've reached the 'drop' window and then add back this 'drop' one
mtu at a time.  This worked well in testing and under stress produced
rather even recovery.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>