[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, 12 insertions, 0 deletions

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index b42f74617bac..c0eb26a0d0bc 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -441,6 +441,7 @@ struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, __be32 prefix,
 
 static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
+        struct net *net = skb->sk->sk_net;
         struct nlattr *tb[IFA_MAX+1];
         struct in_device *in_dev;
         struct ifaddrmsg *ifm;
@@ -449,6 +450,9 @@ static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg
 
         ASSERT_RTNL();
 
+        if (net != &init_net)
+                return -EINVAL;
+
         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy);
         if (err < 0)
                 goto errout;
@@ -560,10 +564,14 @@ errout:
 
 static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
+        struct net *net = skb->sk->sk_net;
         struct in_ifaddr *ifa;
 
         ASSERT_RTNL();
 
+        if (net != &init_net)
+                return -EINVAL;
+
         ifa = rtm_to_ifaddr(nlh);
         if (IS_ERR(ifa))
                 return PTR_ERR(ifa);
@@ -1174,12 +1182,16 @@ nla_put_failure:
 
 static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
+        struct net *net = skb->sk->sk_net;
         int idx, ip_idx;
         struct net_device *dev;
         struct in_device *in_dev;
         struct in_ifaddr *ifa;
         int s_ip_idx, s_idx = cb->args[0];
 
+        if (net != &init_net)
+                return 0;
+
         s_ip_idx = ip_idx = cb->args[1];
         idx = 0;
         for_each_netdev(&init_net, dev) {