netfilter: ip_tables: pass table pointer via nf_hook_ops

iptable_x modules rely on 'struct net' to contain a pointer to the
table that should be evaluated.

In order to remove these pointers from struct net, pass them via
the 'priv' pointer in a similar fashion as nf_tables passes the
rule data.

To do that, duplicate the nf_hook_info array passed in from the
iptable_x modules, update the ops->priv pointers of the copy to
refer to the table and then change the hookfn implementations to
just pass the 'priv' argument to the traverser.

After this patch, the xt_table pointers can already be removed
from struct net.

However, changes to struct net result in re-compile of the entire
network stack, so do the removal after arptables and ip6tables
have been converted as well.

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

1 files changed, 3 insertions, 5 deletions

diff --git a/net/ipv4/netfilter/iptable_raw.c b/net/ipv4/netfilter/iptable_raw.c
index 18776f5a4055..ceef397c1f5f 100644
--- a/net/ipv4/netfilter/iptable_raw.c
+++ b/net/ipv4/netfilter/iptable_raw.c
@@ -41,7 +41,7 @@ static unsigned int
 iptable_raw_hook(void *priv, struct sk_buff *skb,
 		 const struct nf_hook_state *state)
 {
-	return ipt_do_table(skb, state, state->net->ipv4.iptable_raw);
+	return ipt_do_table(skb, state, priv);
 }
 
 static struct nf_hook_ops *rawtable_ops __read_mostly;
@@ -58,21 +58,19 @@ static int __net_init iptable_raw_table_init(struct net *net)
 	repl = ipt_alloc_initial_table(table);
 	if (repl == NULL)
 		return -ENOMEM;
-	ret = ipt_register_table(net, table, repl, rawtable_ops,
-				 &net->ipv4.iptable_raw);
+	ret = ipt_register_table(net, table, repl, rawtable_ops);
 	kfree(repl);
 	return ret;
 }
 
 static void __net_exit iptable_raw_net_pre_exit(struct net *net)
 {
-	ipt_unregister_table_pre_exit(net, "raw", rawtable_ops);
+	ipt_unregister_table_pre_exit(net, "raw");
 }
 
 static void __net_exit iptable_raw_net_exit(struct net *net)
 {
 	ipt_unregister_table_exit(net, "raw");
-	net->ipv4.iptable_raw = NULL;
 }
 
 static struct pernet_operations iptable_raw_net_ops = {