Re: Netlink connector

[Patrick McHardy <kaber@trash.net>]

Thomas Graf wrote:
> * Patrick McHardy <42E579BC.8000701@trash.net> 2005-07-26 01:46
>
>>You still have to take care of mixed 64/32 bit environments, u64 fields
>>for example are differently alligned.
> 
> My solution to this (in the same patchset) is that we never
> derference u64s but instead copy them.

I don't understand. The problem is mainly u64 embedded in structures,
the structs have different sizes if the u64 is not 8 byte aligned
and the structure size padded to a multiple of 8.

>>Then fix it so we can use more families and groups. I started some work
>>on this, but I'm not sure if I have time to complete it.
>  
> Great, this is one of the remaining issues I haven't solved yet.
> If you want me to take over just hand over your unfinished work
> and I'll integrate it into my patchset.

I started working on it after the OLS party, so no postable code yet :)
The idea for more groups is basically to remove the fixed groups
bitmask from struct sockaddr_nl and use setsockopt to add/remove
multicast subscriptions. If we add the limitation that a packet
can only be multicasted to a single group we can support an arbitary
number of groups, otherwise we would still be limited by size of
skb->cb. This limitation shouldn't be a problem, AFAIK nothing is
multicasting to multiple groups at once right now and the increased
number of groups will allow a better granularity anyway. The main
problem is keeping it backwards-compatible for current netlink users.
If this isn't possible we may need to call it netlink2.

Regards
Patrick