netfilter: add glue code to integrate nfnetlink_queue and ctnetlink
This patch allows you to include the conntrack information together
with the packet that is sent to user-space via NFQUEUE.
Previously, there was no integration between ctnetlink and
nfnetlink_queue. If you wanted to access conntrack information
from your libnetfilter_queue program, you required to query
ctnetlink from user-space to obtain it. Thus, delaying the packet
processing even more.
Including the conntrack information is optional, you can set it
via NFQA_CFG_F_CONNTRACK flag with the new NFQA_CFG_FLAGS attribute.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 4541f33..ba65bfb 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -393,6 +393,16 @@
extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *) __rcu;
extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
+
+struct nf_conn;
+struct nlattr;
+
+struct nfq_ct_hook {
+ size_t (*build_size)(const struct nf_conn *ct);
+ int (*build)(struct sk_buff *skb, struct nf_conn *ct);
+ int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
+};
+extern struct nfq_ct_hook *nfq_ct_hook;
#else
static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
#endif