netfilter: nfnetlink: netns support

Make nfnl socket per-petns.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 42 insertions, 23 deletions

diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index eedc0c1ac7a4..8eb0cc23ada3 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -40,7 +40,6 @@ MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER);
 
 static char __initdata nfversion[] = "0.30";
 
-static struct sock *nfnl = NULL;
 static const struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT];
 static DEFINE_MUTEX(nfnl_mutex);
 
@@ -101,34 +100,35 @@ nfnetlink_find_client(u_int16_t type, const struct nfnetlink_subsystem *ss)
 	return &ss->cb[cb_id];
 }
 
-int nfnetlink_has_listeners(unsigned int group)
+int nfnetlink_has_listeners(struct net *net, unsigned int group)
 {
-	return netlink_has_listeners(nfnl, group);
+	return netlink_has_listeners(net->nfnl, group);
 }
 EXPORT_SYMBOL_GPL(nfnetlink_has_listeners);
 
-int nfnetlink_send(struct sk_buff *skb, u32 pid,
+int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 pid,
 		   unsigned group, int echo, gfp_t flags)
 {
-	return nlmsg_notify(nfnl, skb, pid, group, echo, flags);
+	return nlmsg_notify(net->nfnl, skb, pid, group, echo, flags);
 }
 EXPORT_SYMBOL_GPL(nfnetlink_send);
 
-void nfnetlink_set_err(u32 pid, u32 group, int error)
+void nfnetlink_set_err(struct net *net, u32 pid, u32 group, int error)
 {
-	netlink_set_err(nfnl, pid, group, error);
+	netlink_set_err(net->nfnl, pid, group, error);
 }
 EXPORT_SYMBOL_GPL(nfnetlink_set_err);
 
-int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags)
+int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u_int32_t pid, int flags)
 {
-	return netlink_unicast(nfnl, skb, pid, flags);
+	return netlink_unicast(net->nfnl, skb, pid, flags);
 }
 EXPORT_SYMBOL_GPL(nfnetlink_unicast);
 
 /* Process one complete nfnetlink message. */
 static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
+	struct net *net = sock_net(skb->sk);
 	const struct nfnl_callback *nc;
 	const struct nfnetlink_subsystem *ss;
 	int type, err;
@@ -170,7 +170,7 @@ replay:
 		if (err < 0)
 			return err;
 
-		err = nc->call(nfnl, skb, nlh, (const struct nlattr **)cda);
+		err = nc->call(net->nfnl, skb, nlh, (const struct nlattr **)cda);
 		if (err == -EAGAIN)
 			goto replay;
 		return err;
@@ -184,26 +184,45 @@ static void nfnetlink_rcv(struct sk_buff *skb)
 	nfnl_unlock();
 }
 
-static void __exit nfnetlink_exit(void)
+static int __net_init nfnetlink_net_init(struct net *net)
 {
-	printk("Removing netfilter NETLINK layer.\n");
-	netlink_kernel_release(nfnl);
-	return;
+	struct sock *nfnl;
+
+	nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, NFNLGRP_MAX,
+				     nfnetlink_rcv, NULL, THIS_MODULE);
+	if (!nfnl)
+		return -ENOMEM;
+	net->nfnl_stash = nfnl;
+	rcu_assign_pointer(net->nfnl, nfnl);
+	return 0;
 }
 
-static int __init nfnetlink_init(void)
+static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list)
 {
-	printk("Netfilter messages via NETLINK v%s.\n", nfversion);
+	struct net *net;
 
-	nfnl = netlink_kernel_create(&init_net, NETLINK_NETFILTER, NFNLGRP_MAX,
-				     nfnetlink_rcv, NULL, THIS_MODULE);
-	if (!nfnl) {
-		printk(KERN_ERR "cannot initialize nfnetlink!\n");
-		return -ENOMEM;
-	}
+	list_for_each_entry(net, net_exit_list, exit_list)
+		rcu_assign_pointer(net->nfnl, NULL);
+	synchronize_net();
+	list_for_each_entry(net, net_exit_list, exit_list)
+		netlink_kernel_release(net->nfnl_stash);
+}
 
-	return 0;
+static struct pernet_operations nfnetlink_net_ops = {
+	.init		= nfnetlink_net_init,
+	.exit_batch	= nfnetlink_net_exit_batch,
+};
+
+static int __init nfnetlink_init(void)
+{
+	printk("Netfilter messages via NETLINK v%s.\n", nfversion);
+	return register_pernet_subsys(&nfnetlink_net_ops);
 }
 
+static void __exit nfnetlink_exit(void)
+{
+	printk("Removing netfilter NETLINK layer.\n");
+	unregister_pernet_subsys(&nfnetlink_net_ops);
+}
 module_init(nfnetlink_init);
 module_exit(nfnetlink_exit);