[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, 31 insertions, 0 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a70cecf8fc8..26de8ee5095 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2971,11 +2971,15 @@ static const struct nla_policy ifa_ipv6_policy[IFA_MAX+1] = {
 static int
 inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
+        struct net *net = skb->sk->sk_net;
         struct ifaddrmsg *ifm;
         struct nlattr *tb[IFA_MAX+1];
         struct in6_addr *pfx;
         int err;
 
+        if (net != &init_net)
+                return -EINVAL;
+
         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
         if (err < 0)
                 return err;
@@ -3028,6 +3032,7 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u8 ifa_flags,
 static int
 inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
+        struct net *net = skb->sk->sk_net;
         struct ifaddrmsg *ifm;
         struct nlattr *tb[IFA_MAX+1];
         struct in6_addr *pfx;
@@ -3037,6 +3042,9 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
         u8 ifa_flags;
         int err;
 
+        if (net != &init_net)
+                return -EINVAL;
+
         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
         if (err < 0)
                 return err;
@@ -3310,26 +3318,42 @@ done:
 
 static int inet6_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
+        struct net *net = skb->sk->sk_net;
         enum addr_type_t type = UNICAST_ADDR;
+
+        if (net != &init_net)
+                return 0;
+
         return inet6_dump_addr(skb, cb, type);
 }
 
 static int inet6_dump_ifmcaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
+        struct net *net = skb->sk->sk_net;
         enum addr_type_t type = MULTICAST_ADDR;
+
+        if (net != &init_net)
+                return 0;
+
         return inet6_dump_addr(skb, cb, type);
 }
 
 
 static int inet6_dump_ifacaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
+        struct net *net = skb->sk->sk_net;
         enum addr_type_t type = ANYCAST_ADDR;
+
+        if (net != &init_net)
+                return 0;
+
         return inet6_dump_addr(skb, cb, type);
 }
 
 static int inet6_rtm_getaddr(struct sk_buff *in_skb, struct nlmsghdr* nlh,
                              void *arg)
 {
+        struct net *net = in_skb->sk->sk_net;
         struct ifaddrmsg *ifm;
         struct nlattr *tb[IFA_MAX+1];
         struct in6_addr *addr = NULL;
@@ -3338,6 +3362,9 @@ static int inet6_rtm_getaddr(struct sk_buff *in_skb, struct nlmsghdr* nlh,
         struct sk_buff *skb;
         int err;
 
+        if (net != &init_net)
+                return -EINVAL;
+
         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
         if (err < 0)
                 goto errout;
@@ -3555,11 +3582,15 @@ nla_put_failure:
 
 static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 {
+        struct net *net = skb->sk->sk_net;
         int idx, err;
         int s_idx = cb->args[0];
         struct net_device *dev;
         struct inet6_dev *idev;
 
+        if (net != &init_net)
+                return 0;
+
         read_lock(&dev_base_lock);
         idx = 0;
         for_each_netdev(&init_net, dev) {