BPF filtering?

Krystian Lewandowski citan at kolos.math.uni.lodz.pl
Tue Jul 12 16:04:56 UTC 2005


it's my first post on this list, so prepare for short introduction...
my name is Krystian, i'm student and i'm writing document about RTEMS,
now i think about dhcp server implementation as a practical example.

Of course before i started writing from scratch i tried using ISC dhcpd
(1.0.0 version, for its size and simplicity). And good news is that ISC
dhcpd is prepared for NetBSD platform - inter alia, on which RTEMS is
based. If you are interested with more detailed description, feel free
writing to me. Now i can say only it doesn't work as i would expect,
but it's beginning. And i don't know if i've got as much knowledge as it
will be needed for running ISC dhcpd in RTEMS.

But there is one thing, i want to ask - about Berkley Packet Filter in
RTEMS. How i should use it with my app? Are there any examples?

BPF is used in ISC dhcpd (you can see it more detailed here

Only first step now:

- creating socket:
        sock = open ("/dev/bpf0", O_RDWR, 0);

I will use RTEMS msdos fs implementation. But as i can see in sapi
/dev/ implementation is independent from "userland" fs. This function
call returns with error. Should i create /dev/bpfN file with
O_CREAT - is it legal here? Maybe it should be created with
rtems_io_register_name, included in Device_driver_table?

And short questions - is writev or poll function call supported

Sorry for my poor english.
Krystian Lewandowski <jid:citan at jabber.org>

More information about the users mailing list