netdev - Send SFP event from kernel driver to user space (UDEV)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <a041bba0-83d1-331f-d263-c8cbb0509220@mellanox.com>
Date:   Sun, 17 Nov 2019 11:46:15 +0000
From:   Shay Drory <shayd@...lanox.com>
To:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
CC:     Maor Gottlieb <maorg@...lanox.com>,
        Eran Ben Elisha <eranbe@...lanox.com>,
        "lennart@...ttering.net" <lennart@...ttering.net>,
        Saeed Mahameed <saeedm@...lanox.com>
Subject: Send SFP event from kernel driver to user space (UDEV)

Today, SFP inserted / removal event impacts only the kernel space drivers.
There are users who wishes to get SFP insert / removal in a udev-event
format for their application / daemons / monitors.
The naive way to implement this feature would be to create a sysfs file
that represents device SFP, to expose it under the netdev sysfs, and
to raise a udev event over it.
However, it is not reasonable to create a sysfs for each net-device.
In this letter, I would like to offer a new mechanism that will add a
support to send SFP events from the kernel driver to user space.
This suggestion is built upon a new netlink infrastructure for ethtool
currently being written by Michal Kubeckwhich called “ethtool-netlink”[1].
My suggestion is to do it by adding a function
(ethtool_sfp_insterted/removed(...)) to ethtool API, This function will
raise a netlink event to be caught in user space.
The design:

- SFP event from NIC caught by the driver
- Driver call ethtool_sfp_inserted/removed()
- Ethtool generated netlink event with relevant data
- This event-message will be handled in the user-space library of UDEV
(for this purpose we would like to add a netlink infrastructure to UDEV
user-space library).

the flow in scheme:

UDEV (in systemd)
                 ↑
ethtool_netlink (in ethtool)
                 ↑
driver (mlx5_core for example)
                 ↑
NIC (SFP event)

Would like to hear your opinion on this suggestion, or on alternative
designs.

Thanks
Shay Drory

[1]
https://patchwork.ozlabs.org/project/netdev/list/?series=&submitter=11892&state=*&q=&archive=&delegate=