[LiSA-Users] Can i use LISA for..?

[Radu Rendec]

Hi,

Sorry for my late reply! I don't understand exactly what you are trying
to accomplish (because I know little about wireless networks), but I
clearly got the part that you need to bridge input frames based on the
destination address.

LiSA has the ability to be assigned static mac addresses on its ports,
so frames would be handed directly to those ports and the
broadcast-learn mechanism would be skipped.

If you are not familiar with kernel space programming and you tested
everything in user space, I suggest you stay in user space. If you don't
need to do anything special with packet switching and the basic
switching algorithms are enough, you could just inspect some control
packets (handshake or whatever) from userspace and have LiSA's switching
engine handle frame switching in kernel space. In fact this is the
approach we use in the latest LiSA development branch. Additional
protocols like cdp and vtp are user space daemons and control frames
(cdp advertisments, vtp updates etc.) are examined from userspace. If
you are interested, I can give you further details on why we think this
is the best approach.

We even created a special type of socket to help us easily capture
"special" packets (cdp / vtp) and hand them to the userspace daemons.

For controlling LiSA, there are two options:
* use the swctl tool supplied with LiSA to add or remove static mac
address entries; or
* have a look at swctl.c and make LiSA ioctl() calls directly from your
program(s).

For capturing some packets for userspace processing, there are also many
options:
* use libpcap for capturing and libnet for sending;
* get the development branch of LiSA and tweak the capturing code to
suit your needs.

Whatever you choose, DON'T try to configure LiSA (add or remove mac
addresses or whatever) from KERNEL SPACE. If you do that, you have 90%
chances to break the data structure synchronization and get an unstable
switching engine.

Should you have any other questions, feel free to ask, but use the
lisa-users at lisa.ines.ro address. At least Ionut (the other core
developer) will also read your mail.

Best regards,

Radu Rendec


On Wed, 2007-06-27 at 09:46 +0200, Ivan Muccini wrote:
> I, i'm an italian student.
> I'm doing some research in wireless mesh network for my thesis.
> I have developed an user space layer-2 routing protcol like hwmp
> protocol, in 802.11s standard.
> I'm doing some semplification in my implmetation. I'm working with
> madwifi-ng driver. 
> I have my "forwarding" table in user space and I need to porting it
> somewhere in the linux bridge...
> I create a WDS interface (VAP) for every neighbour I discover and I
> put the virtual interfaces in a bridge, with spanning tree disabled. 
> 
> I nedd to bridge the input frames to a specific output interface of
> the bridge based on destination address. So I need the bridge work as
> a controlled switch, not as a bridge. Or I nedd a switch like LISA...
> 
> Do you have a suggestion about what "tool" I can use? Do you think I
> can do that with LISA instead?
> 
> Muccini Ivan
>