Re: make XDP program aware of multi buffer

[Henning Fehrmann <henning.fehrmann@aei.mpg.de>]

> You just replace:
> 
> SEC("xdp")
> 
> with
> 
> SEC("xdp.frags")
> 
> in your source file and, assuming your libbpf version is up-to-date,
> that should be it as far as the kernel is concerned.

Nice. It loads now. I appreciate the work done for multi buffer packets.

> 
> However, you obviously also need to make sure there are no semantic
> issues in your program before doing this. I.e., data_end is no longer
> the end of your packet, so if you are using data_end-data to calculate
> the packet len, that will no longer be accurate. If you need to access
> data beyond the first frag you'll need to use the
> xdp_{load,store}_bytes() helpers.

I guess, this is not the case or does bpf_redirect needs it if I have
multi frame packets?
I realized that redirection actually doesn't happen if the packets
exceed the page size.

Thank you,
Henning