4 files changed, 39 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-net b/Documentation/ABI/testing/sysfs-class-net
index 416c5d59f52e..d322b0581194 100644
--- a/Documentation/ABI/testing/sysfs-class-net
+++ b/Documentation/ABI/testing/sysfs-class-net
@@ -1,3 +1,14 @@
+What:           /sys/class/net/<iface>/name_assign_type
+Date:           July 2014
+KernelVersion:  3.17
+Contact:        netdev@vger.kernel.org
+Description:
+                Indicates the name assignment type. Possible values are:
+                1: enumerated by the kernel, possibly in an unpredictable way
+                2: predictably named by the kernel
+                3: named by userspace
+                4: renamed
+
 What:           /sys/class/net/<iface>/addr_assign_type
 Date:           July 2010
 KernelVersion:  3.2
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3a320db96180..9be34732142f 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1381,6 +1381,8 @@ struct net_device {
         struct kset             *queues_kset;
 #endif
 
+        unsigned char           name_assign_type;
+
         bool                    uc_promisc;
         unsigned int            promiscuity;
         unsigned int            allmulti;
diff --git a/include/uapi/linux/netdevice.h b/include/uapi/linux/netdevice.h
index fdfbd1c17065..55818543342d 100644
--- a/include/uapi/linux/netdevice.h
+++ b/include/uapi/linux/netdevice.h
@@ -37,6 +37,12 @@
 #define INIT_NETDEV_GROUP       0
 
 
+/* interface name assignment types (sysfs name_assign_type attribute) */
+#define NET_NAME_UNKNOWN        0       /* unknown origin (not exposed to userspace) */
+#define NET_NAME_ENUM           1       /* enumerated by kernel */
+#define NET_NAME_PREDICTABLE    2       /* predictably named by the kernel */
+#define NET_NAME_USER           3       /* provided by user-space */
+#define NET_NAME_RENAMED        4       /* renamed by user-space */
 
 /* Media selection options. */
 enum {
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 1cac29ebb05b..7752f2ad49a5 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -112,6 +112,25 @@ NETDEVICE_SHOW_RO(ifindex, fmt_dec);
 NETDEVICE_SHOW_RO(type, fmt_dec);
 NETDEVICE_SHOW_RO(link_mode, fmt_dec);
 
+static ssize_t format_name_assign_type(const struct net_device *net, char *buf)
+{
+        return sprintf(buf, fmt_dec, net->name_assign_type);
+}
+
+static ssize_t name_assign_type_show(struct device *dev,
+                                     struct device_attribute *attr,
+                                     char *buf)
+{
+        struct net_device *net = to_net_dev(dev);
+        ssize_t ret = -EINVAL;
+
+        if (net->name_assign_type != NET_NAME_UNKNOWN)
+                ret = netdev_show(dev, attr, buf, format_name_assign_type);
+
+        return ret;
+}
+static DEVICE_ATTR_RO(name_assign_type);
+
 /* use same locking rules as GIFHWADDR ioctl's */
 static ssize_t address_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
@@ -387,6 +406,7 @@ static struct attribute *net_class_attrs[] = {
         &dev_attr_dev_port.attr,
         &dev_attr_iflink.attr,
         &dev_attr_ifindex.attr,
+        &dev_attr_name_assign_type.attr,
         &dev_attr_addr_assign_type.attr,
         &dev_attr_addr_len.attr,
         &dev_attr_link_mode.attr,