netfilter: nfnetlink_queue: add security context information

netfilter: nfnetlink_queue: add security context information

This patch adds an additional attribute when sending
packet information via netlink in netfilter_queue module.
It will send additional security context data, so that
userspace applications can verify this context against
their own security databases.

Signed-off-by: Roman Kubiak <r.kubiak@samsung.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[backport from mainline commint, "ef493bd netfilter: nfnetlink_queue: add security context information" for security nether service]
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Change-Id: I304b2851b08a9c5c01c340cbbf273b491faa6c30