[HECnet] Apples MAC OS X pcap library...

[Jean-Yves Bernier]

At 7:59 PM +0100 2/15/10, Johnny Billquist wrote:

I'll try with a cable tonight to see if that works better than wireless...

I was busy unprotoizing some C sources to feed the pre-ANSI DECUS C
compiler. Since I see you are working on the bridge, I have made some
further tests tonight.

One thing I forgot to mention in my previous mail : On Mac OS/darwin, eth0
is enO.
So, bridge.conf must contain   'local en0'.

The program I use is not your bridge but a very similar one, intended to
see how much work it would be for a Unix box to pretend to be a DECNET
node. Indeed, I copied your pcap initialization part, filter included, then
added my code.

Assume
machine A running node 1.1,
machine B running node 1.2,
machine C running nothing,
all on a wired, switched LAN.

When my program is running on machine C, I see all broadcast packets:
  Router-hello l2rout (DECNET packets, size 60)
  Lev-1-routing (DECNET packets, size 386 and 590x)
  Lev-2-routing (DECNET packets, size 152)
  A few LAN packets, size 60.

Since I am on a switched network, I see none of the unicast packets, for
example when I initiate a DECNET transfer between A and B.

When my program is running on machine B, I see:
  Same packets as above (pcap_setdirection was called with PCAP_D_INOUT).
  Packets identified as data, data-ack, link-service, ils-ack by tcpdump.

Until now, I have not seen a packet in tcpdump I have not seen in my
program, which is basically yours for the pcap part. By the way, I'm
looking for a document describing DECNET frames to dive a little deeper in
that way. Any pointer will be appreciated.

All tests use Apple's libpcap.dylib in /usr/lib, NOT libpcap.a in
/usr/local/lib which was required to install simh on Mac OS X. I'm running
Tiger, so you should have no problems using Leopard.


Well, I realize that this is my first contribution to this list and maybe a
short introduction is due. Here we go...

I have been working with RSX-11M from '80 to '87. First in computer music
research (GRM, Paris), then in pre-press/phototypesetting. Some old systems
have been donated to me, noticeably SMS (Scientific Micro Systems) OEM
LSI-11/73.

As a hobby project, i've resurrected these systems, then linked them to
simh via DECNET. A few details of the project here, unfortunately in french
but I'm sure you will enjoy SEAGATE surgery http://www2.pescadoo.net/pdp/
and maybe DC600 meltdown:
http://www2.pescadoo.net/pdp/photos/TANDBERG/P1010012.JPG

Unfortunately, any interesting RSX software I could share (yet another full
screen editor, a hierarchical filesystem for RSX and some funny drivers)
are locked on a set of magtapes I did not manage to backup before the day
tape drives lifted off earth for an secret destination. So is life...



-- 
Jean-Yves Bernier