[net-next v2] net: ethtool: set a default driver name

From: Tonghao Zhang <redacted>

The netdev (e.g. ifb, bareudp), which not support ethtool ops
(e.g. .get_drvinfo), we can use the rtnl kind as a default name.

ifb netdev may be created by others prefix, not ifbX.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Hao Chen <redacted>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Danielle Ratson <redacted>
Cc: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Tonghao Zhang <redacted>
---
v1: https://lore.kernel.org/all/20211124181858.6c4668db@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com/ (local) 
---
 net/ethtool/ioctl.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index af2d4e022076..8bf161cd5487 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c

@@ -734,6 +734,10 @@ ethtool_get_drvinfo(struct net_device *dev, struct ethtool_devlink_compat *rsp)
 			sizeof(rsp->info.bus_info));
 		strlcpy(rsp->info.driver, dev->dev.parent->driver->name,
 			sizeof(rsp->info.driver));
+	} else if (dev->rtnl_link_ops) {
+		strlcpy(rsp->info.driver, dev->rtnl_link_ops->kind,
+			sizeof(rsp->info.driver));
+
 	} else {
 		return -EOPNOTSUPP;
 	}

-- 
2.27.0