Re: Multicast support with Linux Ethernet drivers

[Gianluca Guida]

Hi,

There's no a solution still, but it should be quite easy to find one.
The problem is that the Mach's glue doesn't handle at the moment the
multicast functionality.
Your solution should be then to hack the both Mach's device interface
and it's linux emulation glue to use advanced device functionalities.

I am CCing Stefan Siegl since he's experiencing the same problem about
wireless extensions.

In Mach we don't have an IOCTL interface,  instead we have set_status
and get_status, which separes reading from writing.
The problem of nework family devices is that set_device is not even
implemented in linux glue. This don't let us change the status of the
device (like MAC address). It's quite easy to implement it though, and
I think that this is what you might want to do to achieve your goal.

What you should do is to add to set_status and get_status some kind of
"NET_MULTICAST" status and set and retrieving it via that interface.
Note that this will affect the user-level exported interface.

Now, some code pointer.

You should look at include/device/net_status.h for user-level exported
interface for set and get status of network devices.

For a list of functions exported by each device family see
i386/i386at/i386at_ds_routines.c

For list of functions (and code itself) exported by net device family
see linux/dev/glue/net.c (note that get_status points to legacy
drivers' handler (device/net_io.c[net_getstat]). It can be confusing
if you don't get this to understand all that mess about the ifp
pointer.

Sorry for my quick, rude and maybe unclear mail, I am in a rush at the moment.

Hope this helps,
Gianluca

--
It was a type of people I did not know, I found them very strange and
they did not inspire confidence at all. Later I learned that I had been
introduced to electronic engineers.
                                                  E. W. Dijkstra