[NET]: Make socket creation namespace safe.

This patch passes in the namespace a new socket should be created in
and has the socket code do the appropriate reference counting.  By
virtue of this all socket create methods are touched.  In addition
the socket create methods are modified so that they will fail if
you attempt to create a socket in a non-default network namespace.

Failing if we attempt to create a socket outside of the default
network namespace ensures that as we incrementally make the network stack
network namespace aware we will not export functionality that someone
has not audited and made certain is network namespace safe.
Allowing us to partially enable network namespaces before all of the
exotic protocols are supported.

Any protocol layers I have missed will fail to compile because I now
pass an extra parameter into the socket creation code.

[ Integrated AF_IUCV build fixes from Andrew Morton... -DaveM ]

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 2 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index e68103475cca..110a19edacc8 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -241,7 +241,7 @@ EXPORT_SYMBOL(build_ehash_secret);
  *      Create an inet socket.
  */
 
-static int inet_create(struct socket *sock, int protocol)
+static int inet_create(struct net *net, struct socket *sock, int protocol)
 {
         struct sock *sk;
         struct list_head *p;
@@ -253,6 +253,9 @@ static int inet_create(struct socket *sock, int protocol)
         int try_loading_module = 0;
         int err;
 
+        if (net != &init_net)
+                return -EAFNOSUPPORT;
+
         if (sock->type != SOCK_RAW &&
             sock->type != SOCK_DGRAM &&
             !inet_ehash_secret)
@@ -320,7 +323,7 @@ lookup_protocol:
         BUG_TRAP(answer_prot->slab != NULL);
 
         err = -ENOBUFS;
-        sk = sk_alloc(PF_INET, GFP_KERNEL, answer_prot, 1);
+        sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, 1);
         if (sk == NULL)
                 goto out;