netfilter: ctnetlink: allow userspace to modify labels
Add the ability to set/clear labels assigned to a conntrack
via ctnetlink.
To allow userspace to only alter specific bits, Pablo suggested to add
a new CTA_LABELS_MASK attribute:
The new set of active labels is then determined via
active = (active & ~mask) ^ changeset
i.e., the mask selects those bits in the existing set that should be
changed.
This follows the same method already used by MARK and CONNMARK targets.
Omitting CTA_LABELS_MASK is the same as setting all bits in CTA_LABELS_MASK
to 1: The existing set is replaced by the one from userspace.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
4 files changed