[PATCH 0/2] fix AF_PACKET PMD rollover fanout mode

[Stephen Hemminger]

On Fri, 23 Oct 2026 17:22:45 +0100
Frank Dressler <frank at dressler.pro> wrote:

> This series fixes a bug in the AF_PACKET PMD that prevented it from
> running in rollover fanout mode.
> 
> History: 364e08f2bb introduced the AF_PACKET PMD in 2014 and
> unconditionally set the rollover flag. In 2025, d3bc77ab05 added
> code allowing the user to select the fanout mode, including rollover
> mode. Both the flag and the mode were introduced in Linux in 2013
> with 77f65ebdca but their combination has been rejected ever since.
> Because of that, rollover mode has never worked in the PMD.
> 
> The first patch clears the rollover _flag_ when the rollover _mode_
> is set.
> 
> The second patch adds a test that checks that each fanout mode the
> PMD supports is accepted by the kernel.
> 
> Frank Dressler (2):
>   net/af_packet: do not set rollover flag in rollover mode
>   test/af_packet: add test for fanout modes

LGTM - applied to next-net