README.BSD

This version of Luke Stras' PPPoE redirector includes support for OpenBSD.
Support for other BSD variants is possible but requires some porting.
To compile for BSD, you will need to add "-DUSE_BPF" in the DEFINES=
string in the Makefile.  You will also need to link against kvm library
(uncomment LIBS=-lkvm in the Makefile).

I am currently running this on a SPARCstation IPX running OpenBSD 2.5.
I get 50Kbytes/sec maximum throughput but only if I saturate the
machine with multiple connections to get around packet loss.  [Under
load BPF reports a number of lost packets.]  At this point, the CPU
on the machine is being fully used.  For Intel users, the IPX is roughly
on par with a fast 486 so anyone with a modern machine should be fine.

NOTE:  I have not run this on an Intel box yet, so there may be some
byte-ordering issues [SPARCs use the same endian as network ordering].
If you get the error message:

	BPF program is broken

after starting, try recompiling with -DSIMPLE_BPF.  If this works,
let me know - it means I've buggered up the byte-ordering in the 
more complex (and better performing) BPF program.

---

Look at the "start" script for an example of how to start this up.
I found the pty-redir program in another package but that package
did not credit it's author.  It is GPL'ed so I have no qualms about
redistributing it.  I've hacked it slightly but otherwise make no
claims on it.  If the author will speak up I'll more than happily 
attribute it.

Other than that, the instructions that came with the original package
more or less apply.  Note that the pppd in OpenBSD 2.5 does not support
the "pty" option, hence the pty-redir program.

---

The BSD specific stuff is made up mostly of 2 chunks:

1.  Berkeley Packet Filter code which handles the reading and writing
    of raw ethernet packets from and to the network.

2.  An ugly bit of kvm code to extract the ethernet address of the
    interface we are interested in.  This works on OpenBSD 2.5, may
    work on other OpenBSD kernels and is unlikely to work anywhere else.
    If it does work anywhere else or if anyone has any better ideas,
    please let me know.

Part 1 should work on any BSD variant or any platform supporting BPF.
Part 2 will require the most porting work.

Changes and comments about the BSD-specific parts are welcome at 
matt@cs.yorku.ca.

Please note:  this is not meant to be an elegant solution, just a stopgap
until something better (i.e. something that doesn't dive in and out
user-space and copy packets everywhere) can be worked out.

Thanks to Luke for writing the Linux version which made the task of
getting my gateway back online significantly easier.

Matt Robinson
Computer Development Manager
Dept. of Computer Science
York Univerity
Toronto, Ontario, Canada
matt@cs.yorku.ca