[libvirt] [PATCH 1/2] util: Functions to update host network device's multicast filter

[Laine Stump]

On 10/08/2014 01:41 PM, Tony Krowiak wrote:
>> Otherwise it looks okay. As we've discussed, it would be nice to use
>> netlink instead of /proc/net and ioctl(), but that can be added later.
> I agree.  When I originally started working on this, that was my plan,
> however; after spending days trying to understand how to use netlink
> to do retrieve the multicast list, I gave up when I found that
> iproute2 does it by reading the file.  Can you point me to some good,
> detailed netlink documentation?  I've googled for it, looked at code
> examples and experimented by writing code snippets and have not been
> able to figure out how to retrieve the multicast list using netlink. 

No :-( That is a *big* problem with netlink, and I went through the same
journey as you (although probably spent less time, as you sent your
first message when I'd only been looking at it for a day or so).

I *think* there is a libnl cache that can be used to retrieve the
multicast list (look for the libnl-devel mailing list archives for a
message I sent there several days ago, along with a couple of
responses), but it's definitely not as straightforward as reading a file
in /proc.