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From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH] net: arp, ipv6: handle special case of tap device
Date: Tue, 02 Oct 2018 22:25:40 -0700 (PDT)
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From: Vladis Dronov <vdronov@redhat.com>
Date: Mon, 1 Oct 2018 07:32:32 -0400 (EDT)

> Probably, this functionality is already used by some userspace, so I
> believe, I cannot just remove TUNSETLINK ioctl.

Who uses it, how do they use it, and what do they sanely expect about
the link layer header properties of a tap device which has had ->type
changed?