[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, 19 insertions, 0 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index fed95a323b28..4edc3dac4ccd 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -703,6 +703,9 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
         int s_idx = cb->args[0];
         struct net_device *dev;
 
+        if (net != &init_net)
+                return 0;
+
         idx = 0;
         for_each_netdev(net, dev) {
                 if (idx < s_idx)
@@ -905,6 +908,9 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
         struct nlattr *tb[IFLA_MAX+1];
         char ifname[IFNAMSIZ];
 
+        if (net != &init_net)
+                return -EINVAL;
+
         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
         if (err < 0)
                 goto errout;
@@ -953,6 +959,9 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
         struct nlattr *tb[IFLA_MAX+1];
         int err;
 
+        if (net != &init_net)
+                return -EINVAL;
+
         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
         if (err < 0)
                 return err;
@@ -1034,6 +1043,9 @@ static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
         struct nlattr *linkinfo[IFLA_INFO_MAX+1];
         int err;
 
+        if (net != &init_net)
+                return -EINVAL;
+
 #ifdef CONFIG_KMOD
 replay:
 #endif
@@ -1160,6 +1172,9 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
         struct sk_buff *nskb;
         int err;
 
+        if (net != &init_net)
+                return -EINVAL;
+
         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
         if (err < 0)
                 return err;
@@ -1195,9 +1210,13 @@ errout:
 
 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
 {
+        struct net *net = skb->sk->sk_net;
         int idx;
         int s_idx = cb->family;
 
+        if (net != &init_net)
+                return 0;
+
         if (s_idx == 0)
                 s_idx = 1;
         for (idx=1; idx<NPROTO; idx++) {