Re: [PATCH] rtnetlink: expose value from SET_NETDEV_DEVTYPE via IFLA_DEVTYPE attribute

[Jiri Pirko <jiri@resnulli.us>]

Tue, Aug 28, 2018 at 10:58:11PM CEST, marcel@holtmann.org wrote:
>The name value from SET_NETDEV_DEVTYPE only ended up in the uevent sysfs
>file as DEVTYPE= information. To avoid any kind of race conditions
>between netlink messages and reading from sysfs, it is useful to add the
>same string as new IFLA_DEVTYPE attribute included in the RTM_NEWLINK
>messages.
>
>For network managing daemons that have to classify ARPHRD_ETHER network
>devices into different types (like Wireless LAN, Bluetooth etc.), this
>avoids the extra round trip to sysfs and parsing of the uevent file.
>
>Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
>---
> include/uapi/linux/if_link.h |  2 ++
> net/core/rtnetlink.c         | 12 ++++++++++++
> 2 files changed, 14 insertions(+)
>
>diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
>index 43391e2d1153..781294972bb4 100644
>--- a/include/uapi/linux/if_link.h
>+++ b/include/uapi/linux/if_link.h
>@@ -166,6 +166,8 @@ enum {
> 	IFLA_NEW_IFINDEX,
> 	IFLA_MIN_MTU,
> 	IFLA_MAX_MTU,
>+	IFLA_DEVTYPE,		/* Name value from SET_NETDEV_DEVTYPE */

This is not something netdev-related. dev->dev.type is struct device_type.
This is a generic "device" thing. Incorrect to expose over
netdev-specific API. Please use "device" API for this.