From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Brenden Blanco <bblanco@plumgrid.com>
Cc: davem@davemloft.net, netdev@vger.kernel.org,
Jamal Hadi Salim <jhs@mojatatu.com>,
Saeed Mahameed <saeedm@dev.mellanox.co.il>,
Martin KaFai Lau <kafai@fb.com>, Ari Saha <as754m@att.com>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Or Gerlitz <gerlitz.or@gmail.com>,
john.fastabend@gmail.com, hannes@stressinduktion.org,
Thomas Graf <tgraf@suug.ch>, Tom Herbert <tom@herbertland.com>,
Daniel Borkmann <daniel@iogearbox.net>,
brouer@redhat.com
Subject: Re: [PATCH v8 01/11] bpf: add XDP prog type for early driver filter
Date: Tue, 12 Jul 2016 15:14:31 +0200 [thread overview]
Message-ID: <20160712151431.26cbac82@redhat.com> (raw)
In-Reply-To: <1468309894-26258-2-git-send-email-bblanco@plumgrid.com>
On Tue, 12 Jul 2016 00:51:24 -0700 Brenden Blanco <bblanco@plumgrid.com> wrote:
> Add a new bpf prog type that is intended to run in early stages of the
> packet rx path. Only minimal packet metadata will be available, hence a
> new context type, struct xdp_md, is exposed to userspace. So far only
> expose the packet start and end pointers, and only in read mode.
>
> An XDP program must return one of the well known enum values, all other
> return codes are reserved for future use. Unfortunately, this
> restriction is hard to enforce at verification time, so take the
> approach of warning at runtime when such programs are encountered. Out
> of bounds return codes should alias to XDP_ABORTED.
This is going to be a serious usability problem, when XDP gets extended
with newer features.
How can users know what XDP capabilities a given driver support?
If the user loads a XDP program using capabilities not avail in the
driver, then all his traffic will be hard dropped.
My proposal is to NOT allow XDP programs to be loaded if they want to use
return-codes/features not supported by the driver. Thus, eBPF programs
register/annotate their needed capabilities upfront (I guess this could
also help HW offload engines).
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2016-07-12 13:14 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-12 7:51 [PATCH v8 00/11] Add driver bpf hook for early packet drop and forwarding Brenden Blanco
2016-07-12 7:51 ` [PATCH v8 01/11] bpf: add XDP prog type for early driver filter Brenden Blanco
2016-07-12 13:14 ` Jesper Dangaard Brouer [this message]
2016-07-12 14:52 ` Tom Herbert
2016-07-12 16:08 ` Jakub Kicinski
2016-07-13 4:14 ` Alexei Starovoitov
2016-07-12 7:51 ` [PATCH v8 02/11] net: add ndo to setup/query xdp prog in adapter rx Brenden Blanco
2016-07-12 7:51 ` [PATCH v8 03/11] rtnl: add option for setting link xdp prog Brenden Blanco
2016-07-12 7:51 ` [PATCH v8 04/11] net/mlx4_en: add support for fast rx drop bpf program Brenden Blanco
2016-07-12 12:02 ` Tariq Toukan
2016-07-13 11:27 ` David Laight
2016-07-13 14:08 ` Brenden Blanco
2016-07-14 7:25 ` Jesper Dangaard Brouer
2016-07-15 3:30 ` Alexei Starovoitov
2016-07-15 8:21 ` Jesper Dangaard Brouer
2016-07-15 16:56 ` Alexei Starovoitov
2016-07-15 16:18 ` Tom Herbert
2016-07-15 16:47 ` Alexei Starovoitov
2016-07-15 17:49 ` Tom Herbert
2016-07-18 9:10 ` Thomas Graf
2016-07-18 11:39 ` Tom Herbert
2016-07-18 12:48 ` Thomas Graf
2016-07-18 13:07 ` Tom Herbert
2016-07-19 2:45 ` Alexei Starovoitov
2016-07-18 19:03 ` Brenden Blanco
2016-07-15 19:09 ` Jesper Dangaard Brouer
2016-07-18 4:01 ` Alexei Starovoitov
2016-07-18 8:35 ` Daniel Borkmann
2016-07-15 18:08 ` Tom Herbert
2016-07-15 18:45 ` Jesper Dangaard Brouer
2016-07-12 7:51 ` [PATCH v8 05/11] Add sample for adding simple drop program to link Brenden Blanco
2016-07-12 7:51 ` [PATCH v8 06/11] net/mlx4_en: add page recycle to prepare rx ring for tx support Brenden Blanco
2016-07-12 12:09 ` Tariq Toukan
2016-07-12 21:18 ` David Miller
2016-07-13 0:54 ` Brenden Blanco
2016-07-13 7:17 ` Tariq Toukan
2016-07-13 15:40 ` Brenden Blanco
2016-07-15 21:52 ` Brenden Blanco
[not found] ` <6d638467-eea6-d3e1-6984-88a1198ef303@gmail.com>
2016-07-19 17:41 ` Brenden Blanco
2016-07-12 7:51 ` [PATCH v8 07/11] bpf: add XDP_TX xdp_action for direct forwarding Brenden Blanco
2016-07-12 7:51 ` [PATCH v8 08/11] net/mlx4_en: break out tx_desc write into separate function Brenden Blanco
2016-07-12 12:16 ` Tariq Toukan
2016-07-12 7:51 ` [PATCH v8 09/11] net/mlx4_en: add xdp forwarding and data write support Brenden Blanco
2016-07-12 7:51 ` [PATCH v8 10/11] bpf: enable direct packet data write for xdp progs Brenden Blanco
2016-07-12 7:51 ` [PATCH v8 11/11] bpf: add sample for xdp forwarding and rewrite Brenden Blanco
2016-07-12 14:38 ` [PATCH v8 00/11] Add driver bpf hook for early packet drop and forwarding Tariq Toukan
2016-07-13 15:00 ` Tariq Toukan
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