This patch adds support for pushing a MAC address out to USB based
ethernet controllers driven by cdc_ncm. With this change, ifconfig can
now set the device's MAC address. For example, the Dell Universal Dock
D6000 is driven by cdc_ncm. The D6000 can now have its MAC address set
by ifconfig, as it can be done in Windows. This was tested with a D6000
using ifconfig on an x86 based chromebook, where iproute2 is not
available.
Signed-off-by: Charles Hyde <charles.hyde@xxxxxxxxxxxx>
Cc: Mario Limonciello <mario.limonciello@xxxxxxxx>
Cc: Oliver Neukum <oliver@xxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
---
drivers/net/usb/cdc_ncm.c | 74 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 73 insertions(+), 1 deletion(-)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 50c05d0f44cb..6fbe88fd7896 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -750,6 +750,78 @@ int cdc_ncm_change_mtu(struct net_device *net, int new_mtu)
}
EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu);
+/* Provide method to get MAC address from the USB device's ethernet controller.
+ * If the device supports CDC_GET_ADDRESS, then we should receive just six bytes.
+ * Otherwise, use the prior method by asking for the descriptor.
+ */
+static int cdc_ncm_get_ethernet_address(struct usbnet *dev, struct cdc_ncm_ctx *ctx)
+{
+ int ret;
+ char * buf;
+
+ buf = kmalloc(ETH_ALEN, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
+ USB_CDC_GET_NET_ADDRESS,
+ USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+ 0, USB_REQ_SET_ADDRESS, buf, ETH_ALEN,
+ USB_CTRL_GET_TIMEOUT);
+ if (ret == ETH_ALEN) {
+ memcpy(dev->net->dev_addr, buf, ETH_ALEN);
+ ret = 0; /* success */
+ } else {
+ ret = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
+ }
+ kfree(buf);
+ return ret;
+}
+
+/* Provide method to push MAC address to the USB device's ethernet controller.
+ * If the device does not support CDC_SET_ADDRESS, then there is no harm and
+ * we proceed as before.
+ */
+static int cdc_ncm_set_ethernet_address(struct usbnet *dev, struct sockaddr *addr)
+{
+ int ret;
+ char * buf;
+
+ buf = kmalloc(ETH_ALEN, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ memcpy(buf, addr->sa_data, ETH_ALEN);
+ ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
+ USB_CDC_SET_NET_ADDRESS,
+ USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+ 0, USB_REQ_SET_ADDRESS, buf, ETH_ALEN,
+ USB_CTRL_GET_TIMEOUT);
+ if (ret == ETH_ALEN)
+ ret = 0; /* success */
+ else if (ret < 0) {
+ dev_dbg(&dev->udev->dev, "bad MAC address put, %d\n", ret);
+ }
+ kfree(buf);
+ return ret;
+}
+
+/* Provide method to push MAC address to the USB device's ethernet controller.
+ */
+int cdc_ncm_set_mac_addr(struct net_device *net, void *p)
+{
+ struct usbnet *dev = netdev_priv(net);
+
+ /*
+ * Try to push the MAC address out to the device. Ignore any errors,
+ * to be compatible with prior versions of this source.
+ */
+ cdc_ncm_set_ethernet_address(dev, (struct sockaddr *)p);
+
+ return eth_mac_addr(net, p);
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_set_mac_addr);
+
static const struct net_device_ops cdc_ncm_netdev_ops = {
.ndo_open = usbnet_open,
.ndo_stop = usbnet_stop,
@@ -757,7 +829,7 @@ static const struct net_device_ops cdc_ncm_netdev_ops = {
.ndo_tx_timeout = usbnet_tx_timeout,
.ndo_get_stats64 = usbnet_get_stats64,
.ndo_change_mtu = cdc_ncm_change_mtu,
- .ndo_set_mac_address = eth_mac_addr,
+ .ndo_set_mac_address = cdc_ncm_set_mac_addr,
.ndo_validate_addr = eth_validate_addr,
};
--
2.20.1
