ipv4: Disallow non-namespace aware protocols to register.

All in-tree ipv4 protocol implementations are now namespace
aware.  Therefore all the run-time checks are superfluous.

Reject registry of any non-namespace aware ipv4 protocol.
Eventually we'll remove prot->netns_ok and this registry
time check as well.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c
index 0f9d09f54bd9..ce848461acbb 100644
--- a/net/ipv4/protocol.c
+++ b/net/ipv4/protocol.c
@@ -37,6 +37,12 @@ const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly;
 
 int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
 {
+        if (!prot->netns_ok) {
+                pr_err("Protocol %u is not namespace aware, cannot register.\n",
+                        protocol);
+                return -EINVAL;
+        }
+
         return !cmpxchg((const struct net_protocol **)&inet_protos[protocol],
                         NULL, prot) ? 0 : -1;
 }