net: Introduce possible_net_t
Having to say
> #ifdef CONFIG_NET_NS
> struct net *net;
> #endif
in structures is a little bit wordy and a little bit error prone.
Instead it is possible to say:
> typedef struct {
> #ifdef CONFIG_NET_NS
> struct net *net;
> #endif
> } possible_net_t;
And then in a header say:
> possible_net_t net;
Which is cleaner and easier to use and easier to test, as the
possible_net_t is always there no matter what the compile options.
Further this allows read_pnet and write_pnet to be functions in all
cases which is better at catching typos.
This change adds possible_net_t, updates the definitions of read_pnet
and write_pnet, updates optional struct net * variables that
write_pnet uses on to have the type possible_net_t, and finally fixes
up the b0rked users of read_pnet and write_pnet.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Eric Dumazet <edumazet@google.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 fab51ce..f733656 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -231,24 +231,27 @@
#endif
+typedef struct {
#ifdef CONFIG_NET_NS
-
-static inline void write_pnet(struct net **pnet, struct net *net)
-{
- *pnet = net;
-}
-
-static inline struct net *read_pnet(struct net * const *pnet)
-{
- return *pnet;
-}
-
-#else
-
-#define write_pnet(pnet, net) do { (void)(net);} while (0)
-#define read_pnet(pnet) (&init_net)
-
+ struct net *net;
#endif
+} possible_net_t;
+
+static inline void write_pnet(possible_net_t *pnet, struct net *net)
+{
+#ifdef CONFIG_NET_NS
+ pnet->net = net;
+#endif
+}
+
+static inline struct net *read_pnet(const possible_net_t *pnet)
+{
+#ifdef CONFIG_NET_NS
+ return pnet->net;
+#else
+ return &init_net;
+#endif
+}
#define for_each_net(VAR) \
list_for_each_entry(VAR, &net_namespace_list, list)