net: Add DEVTYPE support for Ethernet based devices

The Ethernet framing is used for a lot of devices these days. Most
prominent are WiFi and WiMAX based devices. However for userspace
application it is important to classify these devices correctly and
not only see them as Ethernet devices. The daemons like HAL, DeviceKit
or even NetworkManager with udev support tries to do the classification
in userspace with a lot trickery and extra system calls. This is not
good and actually reaches its limitations. Especially since the kernel
does know the type of the Ethernet device it is pretty stupid.

To solve this problem the underlying device type needs to be set and
then the value will be exported as DEVTYPE via uevents and available
within udev.

  # cat /sys/class/net/wlan0/uevent
  DEVTYPE=wlan
  INTERFACE=wlan0
  IFINDEX=5

This is similar to subsystems like USB and SCSI that distinguish
between hosts, devices, disks, partitions etc.

The new SET_NETDEV_DEVTYPE() is a convenience helper to set the actual
device type. All device types are free form, but for convenience the
same strings as used with RFKILL are choosen.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index f6005adcbf9..b8295cbd7e8 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -754,6 +754,10 @@ int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
         return 0;
 }
 
+static struct device_type wiphy_type = {
+        .name   = "wlan",
+};
+
 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
                      struct net_device **new_dev, enum nl80211_iftype type,
                      struct vif_params *params)
@@ -785,6 +789,7 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 
         memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
         SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
+        SET_NETDEV_DEVTYPE(ndev, &wiphy_type);
 
         /* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
         sdata = netdev_priv(ndev);