We must first remove the nfnetlink protocol handler when nf_tables module
is unloaded -- we don't want userspace to submit new change requests once
we've started to tear down nft state.
Furthermore, nfnetlink must not call any subsystem function after
call_batch returned -EAGAIN.
EAGAIN means the subsys mutex was dropped, so its unlikely but possible that
nf_tables subsystem was removed due to 'rmmod nf_tables' on another cpu.
Therefore, we must abort batch completely and not move on to next part of
the batch.
Last, we can't invoke ->abort unless we've checked that the subsystem is
still registered.
Change netns exit path of nf_tables to make sure any incompleted
transaction gets removed on exit.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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