netdev - Re: [RFC bpf-next v3 6/8] flow_dissector: handle no-skb use case

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: <20190323014101.mxeey4tw3gt7o4yi@ast-mbp.dhcp.thefacebook.com>
Date:   Fri, 22 Mar 2019 18:41:03 -0700
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     Stanislav Fomichev <sdf@...ichev.me>
Cc:     Stanislav Fomichev <sdf@...gle.com>, netdev@...r.kernel.org,
        bpf@...r.kernel.org, davem@...emloft.net, ast@...nel.org,
        daniel@...earbox.net, simon.horman@...ronome.com,
        willemb@...gle.com, peterpenkov96@...il.com
Subject: Re: [RFC bpf-next v3 6/8] flow_dissector: handle no-skb use case

On Fri, Mar 22, 2019 at 06:19:57PM -0700, Stanislav Fomichev wrote:
> Are we ok with breaking api in this case? I'm all in on removing this
> extra information. We can always put it back if somebody complains (and
> manually parse in eth_get_headlen case).

Fine. That seems to be the only way forward to clean it all up.
Could you submit patch 1 to bpf tree disallowing vlan fields?
Patch 3 looks like candidate as well?

> We can still have protocol, because in both skb/skb-less cases we have
> it.

proto can work in both cases, but is it needed ? Does program benefit from it?
The kernel side burns extra bytes by copying it and extra branches to handle it.
May be drop it as well?