[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, 4 insertions, 0 deletions

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 946cf38..31b60a0 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -361,6 +361,7 @@ end:
 
 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = skb->sk->sk_net;
 	unsigned int h, s_h;
 	unsigned int e = 0, s_e;
 	struct rt6_rtnl_dump_arg arg;
@@ -369,6 +370,9 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 	struct hlist_node *node;
 	int res = 0;
 
+	if (net != &init_net)
+		return 0;
+
 	s_h = cb->args[0];
 	s_e = cb->args[1];