[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, 11 insertions, 0 deletions

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 848132b6cb7..3b20b6f0982 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -228,6 +228,9 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 	struct nlattr *tb[FRA_MAX+1];
 	int err = -EINVAL, unresolved = 0;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 		goto errout;
 
@@ -358,12 +361,16 @@ errout:
 
 static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 {
+	struct net *net = skb->sk->sk_net;
 	struct fib_rule_hdr *frh = nlmsg_data(nlh);
 	struct fib_rules_ops *ops = NULL;
 	struct fib_rule *rule, *tmp;
 	struct nlattr *tb[FRA_MAX+1];
 	int err = -EINVAL;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 		goto errout;
 
@@ -539,9 +546,13 @@ skip:
 
 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = skb->sk->sk_net;
 	struct fib_rules_ops *ops;
 	int idx = 0, family;
 
+	if (net != &init_net)
+		return -EINVAL;
+
 	family = rtnl_msg_family(cb->nlh);
 	if (family != AF_UNSPEC) {
 		/* Protocol specific dump request */