Re: [PATCH 1/3 v3] net: usb: r8152: Check used MAC passthrough address

From: Jakub Kicinski <kuba@kernel.org>
To: "Limonciello, Mario" <mario.limonciello@amd.com>
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>,
	Andrew Lunn <andrew@lunn.ch>, Oliver Neukum <oneukum@suse.com>,
	Aaron Ma <aaron.ma@canonical.com>,
	henning.schild@siemens.com, linux-usb@vger.kernel.org,
	netdev@vger.kernel.org, davem@davemloft.net,
	hayeswang@realtek.com, tiwai@suse.de
Subject: Re: [PATCH 1/3 v3] net: usb: r8152: Check used MAC passthrough address
Date: Tue, 11 Jan 2022 08:26:53 -0800	[thread overview]
Message-ID: <20220111082653.02050070@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> (raw)
In-Reply-To: <ec2aaeb0-995e-0259-7eca-892d0c878e19@amd.com>

On Tue, 11 Jan 2022 08:57:39 -0600 Limonciello, Mario wrote:
> The important thing to remember is that many of these machines *don't*
> have in-built network controller and rely upon a USB-c network adapter.
> 
> I recall a few reasons.
> 
> 1) Consistency with the UEFI network stack and dual booting Windows when 
> using the machine.  IOW 1 DHCP lease to one network controller, not one OS.
> 
> 2) A (small) part of an onion that is network security.  It allows 
> administrators to allow-list or block-list controllers.
> 
> The example I recall hearing is someone has their laptop stolen and 
> notifies I/T.  I/T removes the MAC address of the pass through address
> from the allow-list and now that laptop can't use any hotel cubes for 
> accessing network resources.
> 
> 3) Resource planning and management of hoteling resources.
> 
> For example allow facilities to monitor whether users are reserving and 
> using the hoteling cubes they reserved.

Interesting, I haven't thought about use case (3).

Do you know how this is implemented on other platforms?