[RFC,PATCH] introduce new API for libnfnetlink

[Pablo Neira Ayuso <pablo@netfilter.org>]

Hi!

I have been spending some time on libnfnetlink these days based on a 
previous patch that I sent some time ago [1]. Since the amount of 
changes would result in API breakages, that is something that I consider 
that we don't want, I decided to start some kind of version 2 of 
libnfnetlink, the major changes from the current version is:

- Uniform error handling via errno
- Use of new netlink ADD_MEMBERSHIP socket option to join multicast groups
- A new approach for challenge functions listen/talk, now they use the 
callbacks registered via register_callback()
- Single loop processing: nfnetlink_process()
- Iterators: more control for the programmer in the nfnetlink data 
processing
- addattr* simplification
- Documentation available

The patch is available at:

http://people.netfilter.org/pablo/libnfnetlink-newapi.patch

This is still a work in progress, it needs more testing. I have plans to 
do something similar for libnetfilter_conntrack in order to solve the 
existing limitations.

Comments welcome.

[1] http://patchwork.netfilter.org/netfilter-devel/patch.pl?id=3315

-- 
The dawn of the fourth age of Linux firewalling is coming; a time of 
great struggle and heroic deeds -- J.Kadlecsik got inspired by J.Morris