3 files changed, 56 insertions, 0 deletions

diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index b60d2dfe4e69..cf343a852534 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -142,6 +142,7 @@ extern const struct sysfs_ops kobj_sysfs_ops;
  */
 enum kobj_ns_type {
         KOBJ_NS_TYPE_NONE = 0,
+        KOBJ_NS_TYPE_NET,
         KOBJ_NS_TYPES
 };
 
diff --git a/net/Kconfig b/net/Kconfig
index 0d68b40fc0e6..f49532053a98 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -45,6 +45,14 @@ config COMPAT_NETLINK_MESSAGES
 
 menu "Networking options"
 
+config NET_NS
+        bool "Network namespace support"
+        default n
+        depends on EXPERIMENTAL && NAMESPACES
+        help
+          Allow user space to create what appear to be multiple instances
+          of the network stack.
+
 source "net/packet/Kconfig"
 source "net/unix/Kconfig"
 source "net/xfrm/Kconfig"
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index c57c4b228bb5..b388cdab9316 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -14,7 +14,9 @@
 #include <linux/netdevice.h>
 #include <linux/if_arp.h>
 #include <linux/slab.h>
+#include <linux/nsproxy.h>
 #include <net/sock.h>
+#include <net/net_namespace.h>
 #include <linux/rtnetlink.h>
 #include <linux/wireless.h>
 #include <linux/vmalloc.h>
@@ -766,6 +768,38 @@ static void rx_queue_remove_kobjects(struct net_device *net)
         kset_unregister(net->queues_kset);
 }
 #endif /* CONFIG_RPS */
+
+static const void *net_current_ns(void)
+{
+        return current->nsproxy->net_ns;
+}
+
+static const void *net_initial_ns(void)
+{
+        return &init_net;
+}
+
+static const void *net_netlink_ns(struct sock *sk)
+{
+        return sock_net(sk);
+}
+
+static struct kobj_ns_type_operations net_ns_type_operations = {
+        .type = KOBJ_NS_TYPE_NET,
+        .current_ns = net_current_ns,
+        .netlink_ns = net_netlink_ns,
+        .initial_ns = net_initial_ns,
+};
+
+static void net_kobj_ns_exit(struct net *net)
+{
+        kobj_ns_exit(KOBJ_NS_TYPE_NET, net);
+}
+
+static struct pernet_operations sysfs_net_ops = {
+        .exit = net_kobj_ns_exit,
+};
+
 #endif /* CONFIG_SYSFS */
 
 #ifdef CONFIG_HOTPLUG
@@ -806,6 +840,13 @@ static void netdev_release(struct device *d)
         kfree((char *)dev - dev->padded);
 }
 
+static const void *net_namespace(struct device *d)
+{
+        struct net_device *dev;
+        dev = container_of(d, struct net_device, dev);
+        return dev_net(dev);
+}
+
 static struct class net_class = {
         .name = "net",
         .dev_release = netdev_release,
@@ -815,6 +856,8 @@ static struct class net_class = {
 #ifdef CONFIG_HOTPLUG
         .dev_uevent = netdev_uevent,
 #endif
+        .ns_type = &net_ns_type_operations,
+        .namespace = net_namespace,
 };
 
 /* Delete sysfs entries but hold kobject reference until after all
@@ -904,5 +947,9 @@ void netdev_initialize_kobject(struct net_device *net)
 
 int netdev_kobject_init(void)
 {
+        kobj_ns_type_register(&net_ns_type_operations);
+#ifdef CONFIG_SYSFS
+        register_pernet_subsys(&sysfs_net_ops);
+#endif
         return class_register(&net_class);
 }