Re: [developer] Raw ethernet packets

[Marcel Telka <marcel@telka.sk>]

On Sun, Jun 02, 2024 at 11:05:40AM +0200, Marcel Telka wrote:
> On Fri, May 31, 2024 at 10:43:03AM +0200, Marcel Telka wrote:
> > I'm trying to send a raw ethernet packet from an userland application
> > but all my attempts so far were unsuccessful.  I basically tried two
> 
> Attached is the testing program ethersend.c that uses both bpf and
> socket approaches to send the raw ethernet frame.  In both cases the
> frame is silently dropped in mac_tx() because fe_tx_srs is NULL:
> 
> https://src.illumos.org/source/xref/illumos-gate/usr/src/uts/common/io/mac/mac_client.c?r=119d61cc&mo=100885&fi=3519#3576
> 
> There is attached the ethersend.d dtrace script that shows the issue:
> 
> # gcc -Wall -lsocket -o ethersend ethersend.c
> # ./ethersend.d -c './ethersend e1000g0' 2>&1 | grep mac_tx
>   1              -> mac_tx                    
>   1               | mac_tx:entry                              0
>   1              <- mac_tx                                    0
>   1            -> mac_tx                      
>   1             | mac_tx:entry                                0
>   1            <- mac_tx                                      0
> 
> Since something similar reportedly works on dilos (I assume it is a fork
> of old illumos-gate) then it looks like the issue is in new illumos.
> 
> I'll try to do some archaeology...

The archeology revealed that the ethersend works on Solaris, but does
not on work on even very old illumos:

Solaris with the net0 network device:

Solaris 11.1 FCS	10/2012		WORKS!
Solaris 11.4 FCS	08/2018		WORKS!

Below is illumos.  All tests with e1000g0 device:

oi_147			10/2010		DOES NOT WORK
oi_151a8		08/2013		DOES NOT WORK
hipster_20131023	10/2013		DOES NOT WORK
dilos 2.0.2.48		11/2019		DOES NOT WORK

I also tested up-to-date illumos (OpenIndiana) with vioif0 interface
(qemu/kvm guest) and it does not work.

Solaris apparently changed something since we parted and even there is
the same hardware underneath (82540EM, VirtualBox) their networking
stack looks differently (net0 vs. e1000g0).  The ethersend simply works
there.

-- 
+-------------------------------------------+
| Marcel Telka   e-mail:   marcel@telka.sk  |
|                homepage: http://telka.sk/ |
+-------------------------------------------+