tree ec71c09d3666e89f6502c161e607d00c93dd2d45
parent 6e1f760e13c75eb0c21c75c6eed918e25b54cd07
author Florian Westphal <fw@strlen.de> 1469098276 +0200
committer Pablo Neira Ayuso <pablo@netfilter.org> 1469199895 +0200

netfilter: conntrack: support a fixed size of 128 distinct labels

The conntrack label extension is currently variable-sized, e.g. if
only 2 labels are used by iptables rules then the labels->bits[] array
will only contain one element.

We track size of each label storage area in the 'words' member.

But in nftables and openvswitch we always have to ask for worst-case
since we don't know what bit will be used at configuration time.

As most arches are 64bit we need to allocate 24 bytes in this case:

struct nf_conn_labels {
    u8            words;   /*     0     1 */
    /* XXX 7 bytes hole, try to pack */
    long unsigned bits[2]; /*     8     24 */

Make bits a fixed size and drop the words member, it simplifies
the code and only increases memory requirements on x86 when
less than 64bit labels are required.

We still only allocate the extension if its needed.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>