git.openwrt.org Git - openwrt/staging/xback.git/blob

   1 From linux-netdev  Tue Dec 03 13:04:55 2024
   2 From: Dominique Martinet <asmadeus () codewreck ! org>
   3 Date: Tue, 03 Dec 2024 13:04:55 +0000
   4 To: linux-netdev
   5 Subject: [PATCH] net: usb: usbnet: restore usb%d name exception for local mac addresses
   6 Message-Id: <20241203130457.904325-1-asmadeus () codewreck ! org>
   7 X-MARC-Message: https://marc.info/?l=linux-netdev&m=173323431631309
   8
   9 From: Dominique Martinet <dominique.martinet@atmark-techno.com>
  10
  11 The previous commit assumed that local addresses always came from the
  12 kernel, but some devices hand out local mac addresses so we ended up
  13 with point-to-point devices with a mac set by the driver, renaming to
  14 eth%d when they used to be named usb%d.
  15
  16 Userspace should not rely on device name, but for the sake of stability
  17 restore the local mac address check portion of the naming exception:
  18 point to point devices which either have no mac set by the driver or
  19 have a local mac handed out by the driver will keep the usb%d name.
  20
  21 Fixes: 8a7d12d674ac ("net: usb: usbnet: fix name regression")
  22 Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
  23 ---
  24  drivers/net/usb/usbnet.c | 20 ++++++++++++++------
  25  1 file changed, 14 insertions(+), 6 deletions(-)
  26
  27 --- a/drivers/net/usb/usbnet.c
  28 +++ b/drivers/net/usb/usbnet.c
  29 @@ -178,6 +178,17 @@ int usbnet_get_ethernet_addr(struct usbn
  30  }
  31  EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
  32
  33 +static bool usbnet_needs_usb_name_format(struct usbnet *dev, struct net_device *net)
  34 +{
  35 +       /* Point to point devices which don't have a real MAC address
  36 +        * (or report a fake local one) have historically used the usb%d
  37 +        * naming. Preserve this..
  38 +        */
  39 +       return (dev->driver_info->flags & FLAG_POINTTOPOINT) != 0 &&
  40 +               (is_zero_ether_addr(net->dev_addr) ||
  41 +                is_local_ether_addr(net->dev_addr));
  42 +}
  43 +
  44  static void intr_complete (struct urb *urb)
  45  {
  46         struct usbnet   *dev = urb->context;
  47 @@ -1766,13 +1777,10 @@ usbnet_probe (struct usb_interface *udev
  48                 if (status < 0)
  49                         goto out1;
  50
  51 -               // heuristic:  "usb%d" for links we know are two-host,
  52 -               // else "eth%d" when there's reasonable doubt.  userspace
  53 -               // can rename the link if it knows better.
  54 +               /* heuristic: rename to "eth%d" if we are not sure this link
  55 +                * is two-host (these links keep "usb%d") */
  56                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
  57 -                   ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
  58 -                    /* somebody touched it*/
  59 -                    !is_zero_ether_addr(net->dev_addr)))
  60 +                   !usbnet_needs_usb_name_format(dev, net))
  61                         strscpy(net->name, "eth%d", sizeof(net->name));
  62                 /* WLAN devices should always be named "wlan%d" */
  63                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)