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| author | Dominique Martinet <dominique.martinet@atmark-techno.com> | 2025-03-26 17:32:36 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-07 10:11:12 +0200 |
| commit | a24520f748db004d2fbb1daf23c331b48c688a1a (patch) | |
| tree | 4fddf2fafa7337a6e0bc4412a6f000c754cf9cf8 | |
| parent | a79ba8ca9882ac07d0de2877b8491b4274f322d8 (diff) | |
| download | linux-a24520f748db004d2fbb1daf23c331b48c688a1a.tar.gz linux-a24520f748db004d2fbb1daf23c331b48c688a1a.tar.bz2 linux-a24520f748db004d2fbb1daf23c331b48c688a1a.zip | |
net: usb: usbnet: restore usb%d name exception for local mac addresses
commit 2ea396448f26d0d7d66224cb56500a6789c7ed07 upstream.
commit 8a7d12d674ac ("net: usb: usbnet: fix name regression") 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.
(some USB LTE modems are known to hand out a stable mac from the locally
administered range; that mac appears to be random (different for
mulitple devices) and can be reset with device-specific commands, so
while such devices would benefit from getting a OUI reserved, we have
to deal with these and might as well preserve the existing behavior
to avoid breaking fragile openwrt configurations and such on upgrade.)
Link: https://lkml.kernel.org/r/20241203130457.904325-1-asmadeus@codewreck.org
Fixes: 8a7d12d674ac ("net: usb: usbnet: fix name regression")
Cc: stable@vger.kernel.org
Tested-by: Ahmed Naseef <naseefkm@gmail.com>
Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Link: https://patch.msgid.link/20250326-usbnet_rename-v2-1-57eb21fcff26@atmark-techno.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/usb/usbnet.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 44179f4e807f..aeab2308b150 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 +1773,11 @@ 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) |