[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, 13 insertions, 1 deletions

diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index 3bc82dc83b38..94256845a057 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -647,11 +647,15 @@ static const struct nla_policy dn_ifa_policy[IFA_MAX+1] = {
 
 static int dn_nl_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
+        struct net *net = skb->sk->sk_net;
         struct nlattr *tb[IFA_MAX+1];
         struct dn_dev *dn_db;
         struct ifaddrmsg *ifm;
         struct dn_ifaddr *ifa, **ifap;
-        int err;
+        int err = -EINVAL;
+
+        if (net != &init_net)
+                goto errout;
 
         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, dn_ifa_policy);
         if (err < 0)
@@ -681,6 +685,7 @@ errout:
 
 static int dn_nl_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
+        struct net *net = skb->sk->sk_net;
         struct nlattr *tb[IFA_MAX+1];
         struct net_device *dev;
         struct dn_dev *dn_db;
@@ -688,6 +693,9 @@ static int dn_nl_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
         struct dn_ifaddr *ifa;
         int err;
 
+        if (net != &init_net)
+                return -EINVAL;
+
         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, dn_ifa_policy);
         if (err < 0)
                 return err;
@@ -793,11 +801,15 @@ errout:
 
 static int dn_nl_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
+        struct net *net = skb->sk->sk_net;
         int idx, dn_idx = 0, skip_ndevs, skip_naddr;
         struct net_device *dev;
         struct dn_dev *dn_db;
         struct dn_ifaddr *ifa;
 
+        if (net != &init_net)
+                return 0;
+
         skip_ndevs = cb->args[0];
         skip_naddr = cb->args[1];