[NET]: Make the loopback device per network namespace.

This patch makes loopback_dev per network namespace.  Adding
code to create a different loopback device for each network
namespace and adding the code to free a loopback device
when a network namespace exits.

This patch modifies all users the loopback_dev so they
access it as init_net.loopback_dev, keeping all of the
code compiling and working.  A later pass will be needed to
update the users to use something other than the initial network
namespace.

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

2 files changed, 3 insertions, 1 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 2088097663b5..71cf409ad17e 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -742,7 +742,6 @@ struct packet_type {
 #include <linux/interrupt.h>
 #include <linux/notifier.h>
 
-extern struct net_device                *loopback_dev;          /* The loopback */
 extern rwlock_t                         dev_base_lock;          /* Device list lock */
 
 
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 3ea4194613ed..13b0e3b547f0 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -9,6 +9,7 @@
 #include <linux/list.h>
 
 struct proc_dir_entry;
+struct net_device;
 struct net {
         atomic_t                count;          /* To decided when the network
                                                  *  namespace should be freed.
@@ -23,6 +24,8 @@ struct net {
         struct proc_dir_entry   *proc_net_stat;
         struct proc_dir_entry   *proc_net_root;
 
+        struct net_device       *loopback_dev;          /* The loopback */
+
         struct list_head        dev_base_head;
         struct hlist_head       *dev_name_head;
         struct hlist_head       *dev_index_head;