diff options
author | Florian Westphal <fw@strlen.de> | 2016-07-05 13:07:23 +0300 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-07-11 12:47:50 +0300 |
commit | 7c9664351980aaa6a4b8837a314360b3a4ad382a (patch) | |
tree | b3c4b235e53c9576adc9eb7eec5ea9a73d406e9b /include/net/netfilter/nf_nat.h | |
parent | 242922a027176cd260c5adce4ba6bbfa3a05190c (diff) | |
download | linux-7c9664351980aaa6a4b8837a314360b3a4ad382a.tar.xz |
netfilter: move nat hlist_head to nf_conn
The nat extension structure is 32bytes in size on x86_64:
struct nf_conn_nat {
struct hlist_node bysource; /* 0 16 */
struct nf_conn * ct; /* 16 8 */
union nf_conntrack_nat_help help; /* 24 4 */
int masq_index; /* 28 4 */
/* size: 32, cachelines: 1, members: 4 */
/* last cacheline: 32 bytes */
};
The hlist is needed to quickly check for possible tuple collisions
when installing a new nat binding. Storing this in the extension
area has two drawbacks:
1. We need ct backpointer to get the conntrack struct from the extension.
2. When reallocation of extension area occurs we need to fixup the bysource
hash head via hlist_replace_rcu.
We can avoid both by placing the hlist_head in nf_conn and place nf_conn in
the bysource hash rather than the extenstion.
We can also remove the ->move support; no other extension needs it.
Moving the entire nat extension into nf_conn would be possible as well but
then we have to add yet another callback for deletion from the bysource
hash table rather than just using nat extension ->destroy hook for this.
nf_conn size doesn't increase due to aligment, followup patch replaces
hlist_node with single pointer.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include/net/netfilter/nf_nat.h')
-rw-r--r-- | include/net/netfilter/nf_nat.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h index 344b1ab19220..02515f7ed4cc 100644 --- a/include/net/netfilter/nf_nat.h +++ b/include/net/netfilter/nf_nat.h @@ -29,8 +29,6 @@ struct nf_conn; /* The structure embedded in the conntrack structure. */ struct nf_conn_nat { - struct hlist_node bysource; - struct nf_conn *ct; union nf_conntrack_nat_help help; #if IS_ENABLED(CONFIG_NF_NAT_MASQUERADE_IPV4) || \ IS_ENABLED(CONFIG_NF_NAT_MASQUERADE_IPV6) |