+static LIST_HEAD(net_sysctl_ro_tables);
+static struct list_head *net_ctl_ro_header_lookup(struct ctl_table_root *root,
+ struct nsproxy *namespaces)
+{
+ return &net_sysctl_ro_tables;
+}
+
+static int net_ctl_ro_header_perms(struct ctl_table_root *root,
+ struct nsproxy *namespaces, struct ctl_table *table)
+{
+ if (namespaces->net_ns == &init_net)
+ return table->mode;
+ else
+ return table->mode & ~0222;
+}
+
+static struct ctl_table_root net_sysctl_ro_root = {
+ .lookup = net_ctl_ro_header_lookup,
+ .permissions = net_ctl_ro_header_perms,
+};
+