Subject: Re: [PATCH iproute2-next 0/5] iproute2: add libbpf support

From: Stephen Hemminger <[email-masked]>
Date: Sat, 28 Nov 2020 22:16:35 -0800

On Fri, 23 Oct 2020 11:38:50 +0800
Hangbin Liu <[email-masked]> wrote:

> This series converts iproute2 to use libbpf for loading and attaching
> BPF programs when it is available. This means that iproute2 will
> correctly process BTF information and support the new-style BTF-defined
> maps, while keeping compatibility with the old internal map definition
> syntax.
> 
> This is achieved by checking for libbpf at './configure' time, and using
> it if available. By default the system libbpf will be used, but static
> linking against a custom libbpf version can be achieved by passing
> LIBBPF_DIR to configure. FORCE_LIBBPF can be set to force configure to
> abort if no suitable libbpf is found (useful for automatic packaging
> that wants to enforce the dependency).
> 
> The old iproute2 bpf code is kept and will be used if no suitable libbpf
> is available. When using libbpf, wrapper code ensures that iproute2 will
> still understand the old map definition format, including populating
> map-in-map and tail call maps before load.
> 
> The examples in bpf/examples are kept, and a separate set of examples
> are added with BTF-based map definitions for those examples where this
> is possible (libbpf doesn't currently support declaratively populating
> tail call maps).

Luca wants to put this in Debian 11 (good idea), but that means:

1. It has to work with 5.10 release and kernel.
2. Someone has to test it.
3. The 5.10 is a LTS kernel release which means BPF developers have
   to agree to supporting LTS releases.

If someone steps up to doing this then I would be happy to merge it now
for 5.10. Otherwise it won't show up until 5.11.