Re: [PATCH net-deletions] net: remove ax25 and amateur radio (hamradio) subsystem

Dan Cross
2026-04-21T17:48:08Z

On Tue, Apr 21, 2026 at 1:14 PM Stephen Hemminger
<stephen@networkplumber.org> wrote:
> On Tue, 21 Apr 2026 12:17:23 -0400
> Dan Cross <crossd@gmail.com> wrote:
>
> > On Tue, Apr 21, 2026 at 9:55 AM Stephen Hemminger
> > <stephen@networkplumber.org> wrote:
> > > On Mon, 20 Apr 2026 19:18:23 -0700
> > > Jakub Kicinski <kuba@kernel.org> wrote:
> > > > Remove the amateur radio (AX.25, NET/ROM, ROSE) protocol implementation
> > > > and all associated hamradio device drivers from the kernel tree.
> > > > This set of protocols has long been a huge bug/syzbot magnet,
> > > > and since nobody stepped up to help us deal with the influx
> > > > of the AI-generated bug reports we need to move it out of tree
> > > > to protect our sanity.
> > > >
> > > > The code is moved to an out-of-tree repo:
> > > > https://github.com/linux-netdev/mod-orphan
> > > > if it's cleaned up and reworked there we can accept it back.
> > >
> > > It would be good if these protocols could be done in userspace
> > > or with BPF?
> >
> > Consensus for a userspace implementation is what folks on linux-hams
> > seem to be converging on.
> >
> > The amateur radio protocols are more or less specific to low-speed
> > links, they are not particularly coupled to anything else that
> > requires running in the kernel, and the main coupling point (IP over
> > AX.25) can be implemented via TAP/TUN.
> >
> > There are several popular packages that already implement AX.25 and
> > NET/ROM in user-space (for the interested, LinBPQ seems to be the
> > canonical example). The main missing piece is ROSE, but it is likely
> > easier to add that to an existing package, or potentially something
> > brand new, than keep it in the kernel.
> >
> > There's no compelling reason to keep these protocols in the kernel,
> > whether in-tree or out-of-tree; at least, one has not been
> > articulated.
>
> Thanks, my other concern is carrying support for these in ip commands.
> If not kernel based, then iproute2 doesn't need to worry.

Agreed.

If someone really wants mimic the existing output of those commands in
the context of a userspace implementation, they could write a wrapper
program that invokes the real thing, and extracts relevant information
from the ham protocol implementation, and interpolates it into the
output. It may be an imperfect simulation, but it's probably close
enough for most users.

- Dan C.