[NET]: Add network namespace clone & unshare support.
This patch allows you to create a new network namespace
using sys_clone, or sys_unshare.
As the network namespace is still experimental and under development
clone and unshare support is only made available when CONFIG_NET_NS is
selected at compile time.
As this patch introduces network namespace support into code paths
that exist when the CONFIG_NET is not selected there are a few
additions made to net_namespace.h to allow a few more functions
to be used when the networking stack is not compiled in.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index ac8f8304..3ea4194 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -38,11 +38,23 @@
extern struct list_head net_namespace_list;
+#ifdef CONFIG_NET
+extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
+#else
+static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
+{
+ /* There is nothing to copy so this is a noop */
+ return net_ns;
+}
+#endif
+
extern void __put_net(struct net *net);
static inline struct net *get_net(struct net *net)
{
+#ifdef CONFIG_NET
atomic_inc(&net->count);
+#endif
return net;
}
@@ -60,19 +72,25 @@
static inline void put_net(struct net *net)
{
+#ifdef CONFIG_NET
if (atomic_dec_and_test(&net->count))
__put_net(net);
+#endif
}
static inline struct net *hold_net(struct net *net)
{
+#ifdef CONFIG_NET
atomic_inc(&net->use_count);
+#endif
return net;
}
static inline void release_net(struct net *net)
{
+#ifdef CONFIG_NET
atomic_dec(&net->use_count);
+#endif
}
extern void net_lock(void);