rpc.mountd: set libtirpc nonblocking mode to avoid DOS

This patch is experimental. In works fine in that it removes the
vulnerability against a DOS attack. rpc.mountd can be blocked by
a bad client, that sends many RPC requests but never reads the
responses. This might happen intentionally or caused by a wrong
network config (MTU). The patch switches on the nonblocking
mode of libtirpc. In that mode writes can block for a max of 2 seconds.
Attackers are forced to send requests slower, as libtirpc will close
a connection if it finds two requests to read at the same time.

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

0 files changed, 0 insertions, 0 deletions