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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 06:16:15 +0000
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 06:16:15 +0000
commit34e3b522eca7e8741cecb7c2241091f181d1bd1f (patch)
tree3b64ac3aa4603539b8f8f384bc39998e29948900 /libdde_linux26/contrib/include/net/netns/generic.h
parentd4e6a14eb3fad1b43a21214db139db441025baf5 (diff)
parent6fafeb146e9efd59140ea58cebd7dd38ae9a6379 (diff)
Merge branch 'upstream-merged'
Diffstat (limited to 'libdde_linux26/contrib/include/net/netns/generic.h')
-rw-r--r--libdde_linux26/contrib/include/net/netns/generic.h49
1 files changed, 49 insertions, 0 deletions
diff --git a/libdde_linux26/contrib/include/net/netns/generic.h b/libdde_linux26/contrib/include/net/netns/generic.h
new file mode 100644
index 00000000..0c04fd2a
--- /dev/null
+++ b/libdde_linux26/contrib/include/net/netns/generic.h
@@ -0,0 +1,49 @@
+/*
+ * generic net pointers
+ */
+
+#ifndef __NET_GENERIC_H__
+#define __NET_GENERIC_H__
+
+#include <linux/rcupdate.h>
+
+/*
+ * Generic net pointers are to be used by modules to put some private
+ * stuff on the struct net without explicit struct net modification
+ *
+ * The rules are simple:
+ * 1. register the ops with register_pernet_gen_device to get the id
+ * of your private pointer;
+ * 2. call net_assign_generic() to put the private data on the struct
+ * net (most preferably this should be done in the ->init callback
+ * of the ops registered);
+ * 3. do not change this pointer while the net is alive;
+ * 4. do not try to have any private reference on the net_generic object.
+ *
+ * After accomplishing all of the above, the private pointer can be
+ * accessed with the net_generic() call.
+ */
+
+struct net_generic {
+ unsigned int len;
+ struct rcu_head rcu;
+
+ void *ptr[0];
+};
+
+static inline void *net_generic(struct net *net, int id)
+{
+ struct net_generic *ng;
+ void *ptr;
+
+ rcu_read_lock();
+ ng = rcu_dereference(net->gen);
+ BUG_ON(id == 0 || id > ng->len);
+ ptr = ng->ptr[id - 1];
+ rcu_read_unlock();
+
+ return ptr;
+}
+
+extern int net_assign_generic(struct net *net, int id, void *data);
+#endif