l4 protocols are demuxed by l3num, l4num pair.
However, almost all l4 trackers are l3 agnostic.
Only exceptions are:
- gre, icmp (ipv4 only)
- icmpv6 (ipv6 only)
This commit gets rid of the l3 mapping, l4 trackers can now be looked up
by their IPPROTO_XXX value alone, which gets rid of the additional l3
indirection.
For icmp, ipcmp6 and gre, add a check on state->pf and
return -NF_ACCEPT in case we're asked to track e.g. icmpv6-in-ipv4,
this seems more fitting than using the generic tracker.
Additionally we can kill the 2nd l4proto definitions that were needed
for v4/v6 split -- they are now the same so we can use single l4proto
struct for each protocol, rather than two.
The EXPORT_SYMBOLs can be removed as all these object files are
part of nf_conntrack with no external references.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
dd2934a957