From: Dominique Martinet <dominique.martinet@xxxxxxxxxxxxxxxxx>
The previous commit assumed that local addresses always came from the
kernel, but some devices hand out local mac addresses so we ended up
with point-to-point devices with a mac set by the driver, renaming to
eth%d when they used to be named usb%d.
Userspace should not rely on device name, but for the sake of stability
restore the local mac address check portion of the naming exception:
point to point devices which either have no mac set by the driver or
have a local mac handed out by the driver will keep the usb%d name.
Fixes: 8a7d12d674ac ("net: usb: usbnet: fix name regression")
Signed-off-by: Dominique Martinet <dominique.martinet@xxxxxxxxxxxxxxxxx>
---
drivers/net/usb/usbnet.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 44179f4e807f..d044dc7b7622 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -178,6 +178,17 @@ int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
}
EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
+static bool usbnet_needs_usb_name_format(struct usbnet *dev, struct net_device *net)
+{
+ /* Point to point devices which don't have a real MAC address
+ * (or report a fake local one) have historically used the usb%d
+ * naming. Preserve this..
+ */
+ return (dev->driver_info->flags & FLAG_POINTTOPOINT) != 0 &&
+ (is_zero_ether_addr(net->dev_addr) ||
+ is_local_ether_addr(net->dev_addr));
+}
+
static void intr_complete (struct urb *urb)
{
struct usbnet *dev = urb->context;
@@ -1762,13 +1773,10 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
if (status < 0)
goto out1;
- // heuristic: "usb%d" for links we know are two-host,
- // else "eth%d" when there's reasonable doubt. userspace
- // can rename the link if it knows better.
+ /* heuristic: rename to "eth%d" if we are not sure this link
+ * is two-host (these links keep "usb%d") */
if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
- ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
- /* somebody touched it*/
- !is_zero_ether_addr(net->dev_addr)))
+ !usbnet_needs_usb_name_format(dev, net))
strscpy(net->name, "eth%d", sizeof(net->name));
/* WLAN devices should always be named "wlan%d" */
if ((dev->driver_info->flags & FLAG_WLAN) != 0)
--
2.47.0
