[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>
diff --git a/include/net/iucv/af_iucv.h b/include/net/iucv/af_iucv.h
index b6c468c..c661c6f 100644
--- a/include/net/iucv/af_iucv.h
+++ b/include/net/iucv/af_iucv.h
@@ -78,7 +78,6 @@
 static void iucv_sock_cleanup_listen(struct sock *parent);
 static void iucv_sock_kill(struct sock *sk);
 static void iucv_sock_close(struct sock *sk);
-static int  iucv_sock_create(struct socket *sock, int proto);
 static int  iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
 			int addr_len);
 static int  iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
diff --git a/include/net/llc_conn.h b/include/net/llc_conn.h
index 00730d2..e2374e3 100644
--- a/include/net/llc_conn.h
+++ b/include/net/llc_conn.h
@@ -93,7 +93,7 @@
 	return skb->cb[sizeof(skb->cb) - 1];
 }
 
-extern struct sock *llc_sk_alloc(int family, gfp_t priority,
+extern struct sock *llc_sk_alloc(struct net *net, int family, gfp_t priority,
 				 struct proto *prot);
 extern void llc_sk_free(struct sock *sk);
 
diff --git a/include/net/sock.h b/include/net/sock.h
index 9ef8b5f..74e1f7d 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -56,6 +56,7 @@
 #include <asm/atomic.h>
 #include <net/dst.h>
 #include <net/checksum.h>
+#include <net/net_namespace.h>
 
 /*
  * This structure really needs to be cleaned up.
@@ -776,7 +777,7 @@
 				SINGLE_DEPTH_NESTING)
 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
 
-extern struct sock		*sk_alloc(int family,
+extern struct sock		*sk_alloc(struct net *net, int family,
 					  gfp_t priority,
 					  struct proto *prot, int zero_it);
 extern void			sk_free(struct sock *sk);
@@ -1005,6 +1006,7 @@
 #endif
 
 	memcpy(nsk, osk, osk->sk_prot->obj_size);
+	get_net(nsk->sk_net);
 #ifdef CONFIG_SECURITY_NETWORK
 	nsk->sk_security = sptr;
 	security_sk_clone(osk, nsk);