[NETFILTER]: ip_tables: per-netns FILTER, MANGLE, RAW

Now, iptables show and configure different set of rules in different
netnss'. Filtering decisions are still made by consulting only
init_net's set.

Changes are identical except naming so no splitting.

P.S.: one need to remove init_net checks in nf_sockopt.c and inet_create()
      to see the effect.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/ipv4.h

@@ -27,5 +27,10 @@ struct netns_ipv4 {
 	struct sock		*fibnl;
 
 	struct netns_frags	frags;
+#ifdef CONFIG_NETFILTER
+	struct xt_table		*iptable_filter;
+	struct xt_table		*iptable_mangle;
+	struct xt_table		*iptable_raw;
+#endif
 };
 #endif

net/ipv4/netfilter/iptable_filter.c

@@ -28,7 +28,7 @@ static struct
 	struct ipt_replace repl;
 	struct ipt_standard entries[3];
 	struct ipt_error term;
-} initial_table __initdata = {
+} initial_table __net_initdata = {
 	.repl = {
 		.name = "filter",
 		.valid_hooks = FILTER_VALID_HOOKS,
@@ -53,14 +53,13 @@ static struct
 	.term = IPT_ERROR_INIT,			/* ERROR */
 };
 
-static struct xt_table __packet_filter = {
+static struct xt_table packet_filter = {
 	.name		= "filter",
 	.valid_hooks	= FILTER_VALID_HOOKS,
 	.lock		= RW_LOCK_UNLOCKED,
 	.me		= THIS_MODULE,
 	.af		= AF_INET,
 };
-static struct xt_table *packet_filter;
 
 /* The work comes in here from netfilter.c. */
 static unsigned int
@@ -70,7 +69,7 @@ ipt_hook(unsigned int hook,
 	 const struct net_device *out,
 	 int (*okfn)(struct sk_buff *))
 {
-	return ipt_do_table(skb, hook, in, out, packet_filter);
+	return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_filter);
 }
 
 static unsigned int
@@ -89,7 +88,7 @@ ipt_local_out_hook(unsigned int hook,
 		return NF_ACCEPT;
 	}
 
-	return ipt_do_table(skb, hook, in, out, packet_filter);
+	return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_filter);
 }
 
 static struct nf_hook_ops ipt_ops[] __read_mostly = {
@@ -120,6 +119,26 @@ static struct nf_hook_ops ipt_ops[] __read_mostly = {
 static int forward = NF_ACCEPT;
 module_param(forward, bool, 0000);
 
+static int __net_init iptable_filter_net_init(struct net *net)
+{
+	/* Register table */
+	net->ipv4.iptable_filter =
+		ipt_register_table(net, &packet_filter, &initial_table.repl);
+	if (IS_ERR(net->ipv4.iptable_filter))
+		return PTR_ERR(net->ipv4.iptable_filter);
+	return 0;
+}
+
+static void __net_exit iptable_filter_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.iptable_filter);
+}
+
+static struct pernet_operations iptable_filter_net_ops = {
+	.init = iptable_filter_net_init,
+	.exit = iptable_filter_net_exit,
+};
+
 static int __init iptable_filter_init(void)
 {
 	int ret;
@@ -132,11 +151,9 @@ static int __init iptable_filter_init(void)
 	/* Entry 1 is the FORWARD hook */
 	initial_table.entries[1].target.verdict = -forward - 1;
 
-	/* Register table */
-	packet_filter = ipt_register_table(&init_net, &__packet_filter,
-					   &initial_table.repl);
-	if (IS_ERR(packet_filter))
-		return PTR_ERR(packet_filter);
+	ret = register_pernet_subsys(&iptable_filter_net_ops);
+	if (ret < 0)
+		return ret;
 
 	/* Register hooks */
 	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
@@ -146,14 +163,14 @@ static int __init iptable_filter_init(void)
 	return ret;
 
  cleanup_table:
-	ipt_unregister_table(packet_filter);
+	unregister_pernet_subsys(&iptable_filter_net_ops);
 	return ret;
 }
 
 static void __exit iptable_filter_fini(void)
 {
 	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
-	ipt_unregister_table(packet_filter);
+	unregister_pernet_subsys(&iptable_filter_net_ops);
 }
 
 module_init(iptable_filter_init);

net/ipv4/netfilter/iptable_mangle.c

@@ -33,7 +33,7 @@ static struct
 	struct ipt_replace repl;
 	struct ipt_standard entries[5];
 	struct ipt_error term;
-} initial_table __initdata = {
+} initial_table __net_initdata = {
 	.repl = {
 		.name = "mangle",
 		.valid_hooks = MANGLE_VALID_HOOKS,
@@ -64,14 +64,13 @@ static struct
 	.term = IPT_ERROR_INIT,			/* ERROR */
 };
 
-static struct xt_table __packet_mangler = {
+static struct xt_table packet_mangler = {
 	.name		= "mangle",
 	.valid_hooks	= MANGLE_VALID_HOOKS,
 	.lock		= RW_LOCK_UNLOCKED,
 	.me		= THIS_MODULE,
 	.af		= AF_INET,
 };
-static struct xt_table *packet_mangler;
 
 /* The work comes in here from netfilter.c. */
 static unsigned int
@@ -81,7 +80,7 @@ ipt_route_hook(unsigned int hook,
 	 const struct net_device *out,
 	 int (*okfn)(struct sk_buff *))
 {
-	return ipt_do_table(skb, hook, in, out, packet_mangler);
+	return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_mangle);
 }
 
 static unsigned int
@@ -113,7 +112,7 @@ ipt_local_hook(unsigned int hook,
 	daddr = iph->daddr;
 	tos = iph->tos;
 
-	ret = ipt_do_table(skb, hook, in, out, packet_mangler);
+	ret = ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_mangle);
 	/* Reroute for ANY change. */
 	if (ret != NF_DROP && ret != NF_STOLEN && ret != NF_QUEUE) {
 		iph = ip_hdr(skb);
@@ -167,15 +166,33 @@ static struct nf_hook_ops ipt_ops[] __read_mostly = {
 	},
 };
 
+static int __net_init iptable_mangle_net_init(struct net *net)
+{
+	/* Register table */
+	net->ipv4.iptable_mangle =
+		ipt_register_table(net, &packet_mangler, &initial_table.repl);
+	if (IS_ERR(net->ipv4.iptable_mangle))
+		return PTR_ERR(net->ipv4.iptable_mangle);
+	return 0;
+}
+
+static void __net_exit iptable_mangle_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.iptable_mangle);
+}
+
+static struct pernet_operations iptable_mangle_net_ops = {
+	.init = iptable_mangle_net_init,
+	.exit = iptable_mangle_net_exit,
+};
+
 static int __init iptable_mangle_init(void)
 {
 	int ret;
 
-	/* Register table */
-	packet_mangler = ipt_register_table(&init_net, &__packet_mangler,
-					    &initial_table.repl);
-	if (IS_ERR(packet_mangler))
-		return PTR_ERR(packet_mangler);
+	ret = register_pernet_subsys(&iptable_mangle_net_ops);
+	if (ret < 0)
+		return ret;
 
 	/* Register hooks */
 	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
@@ -185,14 +202,14 @@ static int __init iptable_mangle_init(void)
 	return ret;
 
  cleanup_table:
-	ipt_unregister_table(packet_mangler);
+	unregister_pernet_subsys(&iptable_mangle_net_ops);
 	return ret;
 }
 
 static void __exit iptable_mangle_fini(void)
 {
 	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
-	ipt_unregister_table(packet_mangler);
+	unregister_pernet_subsys(&iptable_mangle_net_ops);
 }
 
 module_init(iptable_mangle_init);

net/ipv4/netfilter/iptable_raw.c

@@ -14,7 +14,7 @@ static struct
 	struct ipt_replace repl;
 	struct ipt_standard entries[2];
 	struct ipt_error term;
-} initial_table __initdata = {
+} initial_table __net_initdata = {
 	.repl = {
 		.name = "raw",
 		.valid_hooks = RAW_VALID_HOOKS,
@@ -36,14 +36,13 @@ static struct
 	.term = IPT_ERROR_INIT,			/* ERROR */
 };
 
-static struct xt_table __packet_raw = {
+static struct xt_table packet_raw = {
 	.name = "raw",
 	.valid_hooks =  RAW_VALID_HOOKS,
 	.lock = RW_LOCK_UNLOCKED,
 	.me = THIS_MODULE,
 	.af = AF_INET,
 };
-static struct xt_table *packet_raw;
 
 /* The work comes in here from netfilter.c. */
 static unsigned int
@@ -53,7 +52,7 @@ ipt_hook(unsigned int hook,
 	 const struct net_device *out,
 	 int (*okfn)(struct sk_buff *))
 {
-	return ipt_do_table(skb, hook, in, out, packet_raw);
+	return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_raw);
 }
 
 static unsigned int
@@ -71,7 +70,7 @@ ipt_local_hook(unsigned int hook,
 			       "packet.\n");
 		return NF_ACCEPT;
 	}
-	return ipt_do_table(skb, hook, in, out, packet_raw);
+	return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_raw);
 }
 
 /* 'raw' is the very first table. */
@@ -92,15 +91,33 @@ static struct nf_hook_ops ipt_ops[] __read_mostly = {
 	},
 };
 
+static int __net_init iptable_raw_net_init(struct net *net)
+{
+	/* Register table */
+	net->ipv4.iptable_raw =
+		ipt_register_table(net, &packet_raw, &initial_table.repl);
+	if (IS_ERR(net->ipv4.iptable_raw))
+		return PTR_ERR(net->ipv4.iptable_raw);
+	return 0;
+}
+
+static void __net_exit iptable_raw_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.iptable_raw);
+}
+
+static struct pernet_operations iptable_raw_net_ops = {
+	.init = iptable_raw_net_init,
+	.exit = iptable_raw_net_exit,
+};
+
 static int __init iptable_raw_init(void)
 {
 	int ret;
 
-	/* Register table */
-	packet_raw = ipt_register_table(&init_net, &__packet_raw,
-					&initial_table.repl);
-	if (IS_ERR(packet_raw))
-		return PTR_ERR(packet_raw);
+	ret = register_pernet_subsys(&iptable_raw_net_ops);
+	if (ret < 0)
+		return ret;
 
 	/* Register hooks */
 	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
@@ -110,14 +127,14 @@ static int __init iptable_raw_init(void)
 	return ret;
 
  cleanup_table:
-	ipt_unregister_table(packet_raw);
+	unregister_pernet_subsys(&iptable_raw_net_ops);
 	return ret;
 }
 
 static void __exit iptable_raw_fini(void)
 {
 	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
-	ipt_unregister_table(packet_raw);
+	unregister_pernet_subsys(&iptable_raw_net_ops);
 }
 
 module_init(iptable_raw_init);