[NET]: Modify all rtnetlink methods to only work in the initial namespace (v2)

Before I can enable rtnetlink to work in all network namespaces I need
to be certain that something won't break.  So this patch deliberately
disables all of the rtnletlink methods in everything except the
initial network namespace.  After the methods have been audited this
extra check can be disabled.

Changes from v1:
- added IPv6 addrlabel protection

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 9 insertions, 0 deletions

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 53ab8e0..a4ffa2b 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <net/rtnetlink.h>
 #include <net/net_namespace.h>
+#include <net/sock.h>
 #include "br_private.h"
 
 static inline size_t br_nlmsg_size(void)
@@ -107,9 +108,13 @@ errout:
  */
 static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = skb->sk->sk_net;
 	struct net_device *dev;
 	int idx;
 
+	if (net != &init_net)
+		return 0;
+
 	idx = 0;
 	for_each_netdev(&init_net, dev) {
 		/* not a bridge port */
@@ -135,12 +140,16 @@ skip:
  */
 static int br_rtm_setlink(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
 {
+	struct net *net = skb->sk->sk_net;
 	struct ifinfomsg *ifm;
 	struct nlattr *protinfo;
 	struct net_device *dev;
 	struct net_bridge_port *p;
 	u8 new_state;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	if (nlmsg_len(nlh) < sizeof(*ifm))
 		return -EINVAL;