Commit a4aeafa2 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
Browse files

netfilter: xt_nat: pass table to hookfn 



This changes how ip(6)table nat passes the ruleset/table to the
evaluation loop.

At the moment, it will fetch the table from struct net.

This change stores the table in the hook_ops 'priv' argument
instead.

This requires to duplicate the hook_ops for each netns, so
they can store the (per-net) xt_table structure.

The dupliated nat hook_ops get stored in net_generic data area.
They are free'd in the namespace exit path.

This is a pre-requisite to remove the xt_table/ruleset pointers
from struct net.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent f68772ed

net/ipv4/netfilter/iptable_nat.c

+34 −10
Original line number Diff line number Diff line
@@ -13,8 +13,14 @@ 


#include <net/netfilter/nf_nat.h>



struct iptable_nat_pernet {

	struct nf_hook_ops *nf_nat_ops;

};



static int __net_init iptable_nat_table_init(struct net *net);



static unsigned int iptable_nat_net_id __read_mostly;



static const struct xt_table nf_nat_ipv4_table = {

	.name		= "nat",

	.valid_hooks	= (1 << NF_INET_PRE_ROUTING) |
@@ -30,7 +36,7 @@ static unsigned int iptable_nat_do_chain(void *priv, 
					 struct sk_buff *skb,

					 const struct nf_hook_state *state)

{

	return ipt_do_table(skb, state, state->net->ipv4.nat_table);

	return ipt_do_table(skb, state, priv);

}



static const struct nf_hook_ops nf_nat_ipv4_ops[] = {
@@ -60,50 +66,67 @@ static const struct nf_hook_ops nf_nat_ipv4_ops[] = { 
	},

};



static int ipt_nat_register_lookups(struct net *net)

static int ipt_nat_register_lookups(struct net *net, struct xt_table *table)

{

	struct nf_hook_ops *ops = kmemdup(nf_nat_ipv4_ops, sizeof(nf_nat_ipv4_ops), GFP_KERNEL);

	struct iptable_nat_pernet *xt_nat_net = net_generic(net, iptable_nat_net_id);

	int i, ret;



	if (!ops)

		return -ENOMEM;



	for (i = 0; i < ARRAY_SIZE(nf_nat_ipv4_ops); i++) {

		ret = nf_nat_ipv4_register_fn(net, &nf_nat_ipv4_ops[i]);

		ops[i].priv = table;

		ret = nf_nat_ipv4_register_fn(net, &ops[i]);

		if (ret) {

			while (i)

				nf_nat_ipv4_unregister_fn(net, &nf_nat_ipv4_ops[--i]);

				nf_nat_ipv4_unregister_fn(net, &ops[--i]);



			kfree(ops);

			return ret;

		}

	}



	xt_nat_net->nf_nat_ops = ops;

	return 0;

}



static void ipt_nat_unregister_lookups(struct net *net)

{

	struct iptable_nat_pernet *xt_nat_net = net_generic(net, iptable_nat_net_id);

	struct nf_hook_ops *ops = xt_nat_net->nf_nat_ops;

	int i;



	if (!ops)

		return;



	for (i = 0; i < ARRAY_SIZE(nf_nat_ipv4_ops); i++)

		nf_nat_ipv4_unregister_fn(net, &nf_nat_ipv4_ops[i]);

		nf_nat_ipv4_unregister_fn(net, &ops[i]);



	kfree(ops);

}



static int __net_init iptable_nat_table_init(struct net *net)

{

	struct ipt_replace *repl;

	struct xt_table *table;

	int ret;



	repl = ipt_alloc_initial_table(&nf_nat_ipv4_table);

	if (repl == NULL)

		return -ENOMEM;

	ret = ipt_register_table(net, &nf_nat_ipv4_table, repl,

				 NULL, &net->ipv4.nat_table);

				 NULL, &table);

	if (ret < 0) {

		kfree(repl);

		return ret;

	}



	ret = ipt_nat_register_lookups(net);

	ret = ipt_nat_register_lookups(net, table);

	if (ret < 0) {

		ipt_unregister_table_exit(net, "nat");

		net->ipv4.nat_table = NULL;

	} else {

		net->ipv4.nat_table = table;

	}



	kfree(repl);
@@ -112,7 +135,6 @@ static int __net_init iptable_nat_table_init(struct net *net) 


static void __net_exit iptable_nat_net_pre_exit(struct net *net)

{

	if (net->ipv4.nat_table)

	ipt_nat_unregister_lookups(net);

}
@@ -125,6 +147,8 @@ static void __net_exit iptable_nat_net_exit(struct net *net) 
static struct pernet_operations iptable_nat_net_ops = {

	.pre_exit = iptable_nat_net_pre_exit,

	.exit	= iptable_nat_net_exit,

	.id	= &iptable_nat_net_id,

	.size	= sizeof(struct iptable_nat_pernet),

};



static int __init iptable_nat_init(void)

net/ipv6/netfilter/ip6table_nat.c

+35 −10
Original line number Diff line number Diff line
@@ -15,8 +15,14 @@ 


#include <net/netfilter/nf_nat.h>



struct ip6table_nat_pernet {

	struct nf_hook_ops *nf_nat_ops;

};



static int __net_init ip6table_nat_table_init(struct net *net);



static unsigned int ip6table_nat_net_id __read_mostly;



static const struct xt_table nf_nat_ipv6_table = {

	.name		= "nat",

	.valid_hooks	= (1 << NF_INET_PRE_ROUTING) |
@@ -32,7 +38,7 @@ static unsigned int ip6table_nat_do_chain(void *priv, 
					  struct sk_buff *skb,

					  const struct nf_hook_state *state)

{

	return ip6t_do_table(skb, state, state->net->ipv6.ip6table_nat);

	return ip6t_do_table(skb, state, priv);

}



static const struct nf_hook_ops nf_nat_ipv6_ops[] = {
@@ -62,58 +68,75 @@ static const struct nf_hook_ops nf_nat_ipv6_ops[] = { 
	},

};



static int ip6t_nat_register_lookups(struct net *net)

static int ip6t_nat_register_lookups(struct net *net, struct xt_table *table)

{

	struct nf_hook_ops *ops = kmemdup(nf_nat_ipv6_ops, sizeof(nf_nat_ipv6_ops), GFP_KERNEL);

	struct ip6table_nat_pernet *xt_nat_net = net_generic(net, ip6table_nat_net_id);

	int i, ret;



	if (!ops)

		return -ENOMEM;



	for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++) {

		ret = nf_nat_ipv6_register_fn(net, &nf_nat_ipv6_ops[i]);

		ops[i].priv = table;

		ret = nf_nat_ipv6_register_fn(net, &ops[i]);

		if (ret) {

			while (i)

				nf_nat_ipv6_unregister_fn(net, &nf_nat_ipv6_ops[--i]);

				nf_nat_ipv6_unregister_fn(net, &ops[--i]);



			kfree(ops);

			return ret;

		}

	}



	xt_nat_net->nf_nat_ops = ops;

	return 0;

}



static void ip6t_nat_unregister_lookups(struct net *net)

{

	struct ip6table_nat_pernet *xt_nat_net = net_generic(net, ip6table_nat_net_id);

	struct nf_hook_ops *ops = xt_nat_net->nf_nat_ops;

	int i;



	if (!ops)

		return;



	for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++)

		nf_nat_ipv6_unregister_fn(net, &nf_nat_ipv6_ops[i]);

		nf_nat_ipv6_unregister_fn(net, &ops[i]);



	kfree(ops);

}



static int __net_init ip6table_nat_table_init(struct net *net)

{

	struct ip6t_replace *repl;

	struct xt_table *table;

	int ret;



	repl = ip6t_alloc_initial_table(&nf_nat_ipv6_table);

	if (repl == NULL)

		return -ENOMEM;

	ret = ip6t_register_table(net, &nf_nat_ipv6_table, repl,

				  NULL, &net->ipv6.ip6table_nat);

				  NULL, &table);

	if (ret < 0) {

		kfree(repl);

		return ret;

	}



	ret = ip6t_nat_register_lookups(net);

	ret = ip6t_nat_register_lookups(net, table);

	if (ret < 0) {

		ip6t_unregister_table_exit(net, "nat");

		net->ipv6.ip6table_nat = NULL;

	} else {

		net->ipv6.ip6table_nat = table;

	}



	kfree(repl);

	return ret;

}



static void __net_exit ip6table_nat_net_pre_exit(struct net *net)

{

	if (net->ipv6.ip6table_nat)

	ip6t_nat_unregister_lookups(net);

}
@@ -126,6 +149,8 @@ static void __net_exit ip6table_nat_net_exit(struct net *net) 
static struct pernet_operations ip6table_nat_net_ops = {

	.pre_exit = ip6table_nat_net_pre_exit,

	.exit	= ip6table_nat_net_exit,

	.id	= &ip6table_nat_net_id,

	.size	= sizeof(struct ip6table_nat_pernet),

};



static int __init ip6table_nat_init(void)