netdev - Re: [PATCH bpf-next v2 1/2] net: xdp: refactor XDP_QUERY_PROG{,

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: <20190601124233.5a130838@cakuba.netronome.com>
Date:   Sat, 1 Jun 2019 12:42:33 -0700
From:   Jakub Kicinski <jakub.kicinski@...ronome.com>
To:     Saeed Mahameed <saeedm@...lanox.com>
Cc:     "toke@...hat.com" <toke@...hat.com>,
        "daniel@...earbox.net" <daniel@...earbox.net>,
        "ast@...nel.org" <ast@...nel.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "bjorn.topel@...il.com" <bjorn.topel@...il.com>,
        "magnus.karlsson@...el.com" <magnus.karlsson@...el.com>,
        "bjorn.topel@...el.com" <bjorn.topel@...el.com>,
        "brouer@...hat.com" <brouer@...hat.com>,
        "bpf@...r.kernel.org" <bpf@...r.kernel.org>
Subject: Re: [PATCH bpf-next v2 1/2] net: xdp: refactor XDP_QUERY_PROG{,_HW}
 to netdev

On Fri, 31 May 2019 19:18:17 +0000, Saeed Mahameed wrote:
> On Fri, 2019-05-31 at 11:42 +0200, Björn Töpel wrote:
> > From: Björn Töpel <bjorn.topel@...el.com>
> > 
> > All XDP capable drivers need to implement the XDP_QUERY_PROG{,_HW}
> > command of ndo_bpf. The query code is fairly generic. This commit
> > refactors the query code up from the drivers to the netdev level.
> > 
> > The struct net_device has gained two new members: xdp_prog_hw and
> > xdp_flags. The former is the offloaded XDP program, if any, and the
> > latter tracks the flags that the supplied when attaching the XDP
> > program. The flags only apply to SKB_MODE or DRV_MODE, not HW_MODE.
> > 
> > The xdp_prog member, previously only used for SKB_MODE, is shared
> > with
> > DRV_MODE. This is OK, due to the fact that SKB_MODE and DRV_MODE are
> > mutually exclusive. To differentiate between the two modes, a new
> > internal flag is introduced as well.  
> 
> Just thinking out loud, why can't we allow any combination of
> HW/DRV/SKB modes? they are totally different attach points in a totally
> different checkpoints in a frame life cycle.

FWIW see Message-ID: <20190201080236.446d84d4@...hat.com>

> Down the road i think we will utilize this fact and start introducing
> SKB helpers for SKB mode and driver helpers for DRV mode..

Any reason why we would want the extra complexity?  There is cls_bpf
if someone wants skb features after all..