allocating netlink families? (was: re: Announce: NetKeeper Firewall For Linux)

allocating netlink families? (was: re: Announce: NetKeeper Firewall For Linux)

[Dan Kegel]

Emmanuel Fleury wrote:
 >   http://www.cs.auc.dk/~fleury/netkeeper/

Hey, that seems to be a nice example of how to write
a new netlink family.  Thanks!

I see you're using NETLINK_USERSOCK.  Netlink families
appear to be a precious commodity (netlink_dev.c, at
least, will break if you raise MAX_LINKS above 32).

Has there been any discussion of how one should pick
netlink family numbers for new stuff like netkeeper?
Sure, everyone could use NETLINK_USERSOCK, but
that means only one new netlink module could be resident at a time...
- Dan

Re: allocating netlink families? (was: re: Announce: NetKeeper Firewall For Linux)

[David S. Miller]

On Mon, 03 Nov 2003 16:43:20 -0800
Dan Kegel <dkegel@ixiacom.com> wrote:

> Has there been any discussion of how one should pick
> netlink family numbers for new stuff like netkeeper?
> Sure, everyone could use NETLINK_USERSOCK, but
> that means only one new netlink module could be resident at a time...

When it's determined to be useful and to be added to
the main kernel sources, we'll allocate a number.
Before that time, there is no need to allocate.  We'd
run out quickly if everyone with a funny netlink thing they
wanted to do asked for a number.

Re: allocating netlink families?

[Dan Kegel]

David S. Miller wrote:
> On Mon, 03 Nov 2003 16:43:20 -0800
> Dan Kegel <dkegel@ixiacom.com> wrote:
> 
> 
>>Has there been any discussion of how one should pick
>>netlink family numbers for new stuff like netkeeper?
>>Sure, everyone could use NETLINK_USERSOCK, but
>>that means only one new netlink module could be resident at a time...
> 
> 
> When it's determined to be useful and to be added to
> the main kernel sources, we'll allocate a number.
> Before that time, there is no need to allocate.  We'd
> run out quickly if everyone with a funny netlink thing they
> wanted to do asked for a number.

I guess I was really wondering what somebody who wants to
use two netlink things in the same system should do.  Steal
family 31, I suppose.  Ah, well.
I'll just happily use NETLINK_USERSOCK, and won't ask about
clashes until I really run into one.

- Dan

Re: allocating netlink families? (was: re: Announce: NetKeeper Firewall For Linux)

[Emmanuel Fleury]

On Tue, 2003-11-04 at 01:43, Dan Kegel wrote:
> Emmanuel Fleury wrote:
>  >   http://www.cs.auc.dk/~fleury/netkeeper/
> 
> Hey, that seems to be a nice example of how to write
> a new netlink family.  Thanks!

:)

> I see you're using NETLINK_USERSOCK.  Netlink families
> appear to be a precious commodity (netlink_dev.c, at
> least, will break if you raise MAX_LINKS above 32).
> 
> Has there been any discussion of how one should pick
> netlink family numbers for new stuff like netkeeper?

I think netlink is perfect as it is for now. 
Our scheme just demonstrate how flexible is this code.

Before being added "permanently" (I don't like this word) we should get
out with something better than an alpha release. :)

But, even if the process is long, we are still working on it. 
And hopefully one day it will be possible to try Netekeeper easily
on your own network (I have to admit now that the user-space tools are
difficult to get to work, even if I trust a lot the kernel-space code).

> Sure, everyone could use NETLINK_USERSOCK, but
> that means only one new netlink module could be resident at a time...

Yes, this is true, but it doesn't matter so much for experimental things
(in my humble opinion).

Regards
-- 
Emmanuel

But the important thing is persistence.
  -- Calvin trying to juggle eggs (Bill Waterson)