[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, 10 insertions, 0 deletions

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index bb98045d5508..fdab6a530bba 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -23,6 +23,8 @@
 #include <linux/init.h>
 #include <linux/kmod.h>
 #include <linux/netlink.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
 #include <net/netlink.h>
 #include <net/pkt_sched.h>
 #include <net/pkt_cls.h>
@@ -119,6 +121,7 @@ static __inline__ u32 tcf_auto_prio(struct tcf_proto *tp)
 
 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 {
+        struct net *net = skb->sk->sk_net;
         struct rtattr **tca;
         struct tcmsg *t;
         u32 protocol;
@@ -135,6 +138,9 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
         unsigned long fh;
         int err;
 
+        if (net != &init_net)
+                return -EINVAL;
+
 replay:
         tca = arg;
         t = NLMSG_DATA(n);
@@ -375,6 +381,7 @@ static int tcf_node_dump(struct tcf_proto *tp, unsigned long n, struct tcf_walke
 
 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 {
+        struct net *net = skb->sk->sk_net;
         int t;
         int s_t;
         struct net_device *dev;
@@ -385,6 +392,9 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
         const struct Qdisc_class_ops *cops;
         struct tcf_dump_args arg;
 
+        if (net != &init_net)
+                return 0;
+
         if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
                 return skb->len;
         if ((dev = dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)