2 files changed, 40 insertions, 0 deletions

diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index e2aee2689abe..72fad1a0956b 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -185,6 +185,8 @@ extern int register_pernet_subsys(struct pernet_operations *);
 extern void unregister_pernet_subsys(struct pernet_operations *);
 extern int register_pernet_device(struct pernet_operations *);
 extern void unregister_pernet_device(struct pernet_operations *);
+extern int register_pernet_gen_device(int *id, struct pernet_operations *);
+extern void unregister_pernet_gen_device(int id, struct pernet_operations *);
 
 struct ctl_path;
 struct ctl_table;
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 7b660834a4c2..2197d51aef3b 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -5,6 +5,7 @@
 #include <linux/list.h>
 #include <linux/delay.h>
 #include <linux/sched.h>
+#include <linux/idr.h>
 #include <net/net_namespace.h>
 
 /*
@@ -253,6 +254,8 @@ static void unregister_pernet_operations(struct pernet_operations *ops)
 }
 #endif
 
+static DEFINE_IDA(net_generic_ids);
+
 /**
  *      register_pernet_subsys - register a network namespace subsystem
  *      @ops:  pernet operations structure for the subsystem
@@ -330,6 +333,30 @@ int register_pernet_device(struct pernet_operations *ops)
 }
 EXPORT_SYMBOL_GPL(register_pernet_device);
 
+int register_pernet_gen_device(int *id, struct pernet_operations *ops)
+{
+        int error;
+        mutex_lock(&net_mutex);
+again:
+        error = ida_get_new_above(&net_generic_ids, 1, id);
+        if (error) {
+                if (error == -EAGAIN) {
+                        ida_pre_get(&net_generic_ids, GFP_KERNEL);
+                        goto again;
+                }
+                goto out;
+        }
+        error = register_pernet_operations(&pernet_list, ops);
+        if (error)
+                ida_remove(&net_generic_ids, *id);
+        else if (first_device == &pernet_list)
+                first_device = &ops->list;
+out:
+        mutex_unlock(&net_mutex);
+        return error;
+}
+EXPORT_SYMBOL_GPL(register_pernet_gen_device);
+
 /**
  *      unregister_pernet_device - unregister a network namespace netdevice
  *      @ops: pernet operations structure to manipulate
@@ -348,3 +375,14 @@ void unregister_pernet_device(struct pernet_operations *ops)
         mutex_unlock(&net_mutex);
 }
 EXPORT_SYMBOL_GPL(unregister_pernet_device);
+
+void unregister_pernet_gen_device(int id, struct pernet_operations *ops)
+{
+        mutex_lock(&net_mutex);
+        if (&ops->list == first_device)
+                first_device = first_device->next;
+        unregister_pernet_operations(ops);
+        ida_remove(&net_generic_ids, id);
+        mutex_unlock(&net_mutex);
+}
+EXPORT_SYMBOL_GPL(unregister_pernet_gen_device);