linux-kernel - Re: [RFC PATCH net-next V2 0/6] XDP rx handler

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180816040517.7vjm4bwxosyzvapu@ast-mbp.dhcp.thefacebook.com>
Date:   Wed, 15 Aug 2018 21:05:18 -0700
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     Jason Wang <jasowang@...hat.com>
Cc:     David Ahern <dsahern@...il.com>,
        Jesper Dangaard Brouer <jbrouer@...hat.com>,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        ast@...nel.org, daniel@...earbox.net, mst@...hat.com
Subject: Re: [RFC PATCH net-next V2 0/6] XDP rx handler

On Thu, Aug 16, 2018 at 11:34:20AM +0800, Jason Wang wrote:
> > Nothing about the topology is hard coded. The idea is to mimic a
> > hardware pipeline and acknowledging that a port device can have an
> > arbitrary layers stacked on it - multiple vlan devices, bonds, macvlans, etc
> 
> I may miss something but BPF forbids loop. Without a loop how can we make
> sure all stacked devices is enumerated correctly without knowing the
> topology in advance?

not following. why do you need a loop to implement macvlan as an xdp prog?
if loop is needed, such algorithm is not going to scale whether
it's implemented as bpf program or as in-kernel c code.