Re: [9front] rpi4 wifi USB dongle

[hiro <23hiro@gmail.com>]

yeah, sadly that doesn't go into depth at all.

proxy arp is not general enough to solve the real problem with wifi
(e.g. for ipv6 or dhcp).
the problem with wifi is that it cannot be bridged in the traditional
(as per ethernet spec) way.
and we already have mat damon as a solution on 9front. you have quoted
the summary of the explanation above already, if you check mat damon
there's more details if you're curious, or you just ask and you'll get
even more details about this horror.

tap devices are incidental side-effect of how qemu/kvm works on
unix/linux, has nothing to do with this problem.

On 4/23/21, unobe@cpan.org <unobe@cpan.org> wrote:
> Quoth Daniel Morandini <danielmorandini@me.com>:
>> > yeah you got it right.
>> >
>> > it's hard to find good terminology that still makes sense in all this.
>> >
>> > on ethernet all nodes are the same, addressed by MAC addresses. on
>> > wifi a station can only use one mac address, so bridges never work on
>> > wifi stations but only on ap side, of which there can only be one.
>> Now I see. Thank you very, very much.
>
> My reply is dated, but maybe it'll be useful for someone.  On June 4
> of last year, I had this in my 9front setup notes:
>
> """
> Over the last couple of days I've been working to get bilbo
> transitioned from a qemu instance on a macbook pro to a qemu instance
> running on a kvm-capable computer.  I finally got it, but most of the
> time was spent figuring out how to do bridging on a wireless card.
> That was non-trivial.  The qemu documentation was like a scatterplot
> and gave little insight into how to do it, and the resources it
> directed one to were quite dated or didn't work for non-Linux guests.
> Finally, I struck gold with this comment:
> https://unix.stackexchange.com/questions/159191/setup-kvm-on-a-wireless-interface-on-a-laptop-machine
>
> That worked flawlessly.  I also was able to update the kernel from
> running 9pc to 9pc64.  Additionally, the kvm enabling is *well* worth
> the time I spent working on networking and made me appreciate the
> simplicity of plan9 even more.
> """
>
> The idea described at stackexchange is to use a TAP device.  My
> situation was using qemu, so not a native install, but thought I'd
> mention how it worked if anyone was running a virtualized qemu on an
> rpi4 (which is terribly slow--I've done it, but go with what you
> got!).  In the setup described above, I just created a small wrapper
> that did the required bits before starting qemu and after stopping it.
>
>