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From: David Ahern <dsahern@gmail.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: "Toke Høiland-Jørgensen" <toke@redhat.com>,
	"David Ahern" <dsahern@kernel.org>,
	netdev@vger.kernel.org, prashantbhole.linux@gmail.com,
	jasowang@redhat.com, davem@davemloft.net, jbrouer@redhat.com,
	mst@redhat.com, toshiaki.makita1@gmail.com, daniel@iogearbox.net,
	john.fastabend@gmail.com, ast@kernel.org, kafai@fb.com,
	songliubraving@fb.com, yhs@fb.com, andriin@fb.com,
	"David Ahern" <dahern@digitalocean.com>
Subject: Re: [PATCH bpf-next 03/12] net: Add IFLA_XDP_EGRESS for XDP programs in the egress path
Date: Mon, 27 Jan 2020 20:43:09 -0700	[thread overview]
Message-ID: <252acf50-91ff-fdc5-3ce1-491a02de07c6@gmail.com> (raw)
In-Reply-To: <20200127061623.1cf42cd0@cakuba>

On 1/27/20 7:16 AM, Jakub Kicinski wrote:
>> I want to run an ebpf program in the Tx path of the NIC regardless of
>> how the packet arrived at the device -- as an skb or an xdp_frame. There
>> are options for running programs on skb-based packets (e.g., tc). There
>> are *zero* options for manipulating/controlling/denying xdp_frames -
>> e.g., one REDIRECTED from an ingress device.
> 
> Okay - so no precise use case.  You can run the same program at the 

For the sake of this discussion, consider a per-VM, per-tap device ebpf
program for firewall / ACL / traffic verification (packet manipulation
is also a possibility). Small, singly focused ebpf programs - attached
at startup, driven by maps, cleaned up when the tap device is destroyed.
(Remember: Tx for tap device is ingress to a VM.)

Small, singly focused programs only run for traffic to be delivered to
the VM. Setup is easy; cleanup automatic. How the traffic got there
could vary - from a bridge (L2 forwarding), the host stack (L3 routing),
or an XDP program on the host's NICs. It could have arrived at the host
with an encap header which is removed and the inner packet forwarded to
the VM.

> end of whatever is doing the redirect (especially with Alexei's work 

There are use cases where they may make sense, but this is not one.

> on linking) and from cls_bpf 🤷‍♂️
> 

cls_bpf is tc based == skb, no? I want to handle any packet, regardless
of how it arrived at the device's xmit function.

  reply	other threads:[~2020-01-28  3:43 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-23  1:41 [PATCH bpf-next 00/12] Add support for XDP in egress path David Ahern
2020-01-23  1:41 ` [PATCH bpf-next 01/12] net: Add new XDP setup and query commands David Ahern
2020-01-23  1:42 ` [PATCH bpf-next 02/12] net: Add BPF_XDP_EGRESS as a bpf_attach_type David Ahern
2020-01-23 11:34   ` Toke Høiland-Jørgensen
2020-01-23 21:32     ` David Ahern
2020-01-24  9:49       ` Toke Høiland-Jørgensen
2020-01-24  7:33   ` Martin Lau
2020-01-23  1:42 ` [PATCH bpf-next 03/12] net: Add IFLA_XDP_EGRESS for XDP programs in the egress path David Ahern
2020-01-23 11:35   ` Toke Høiland-Jørgensen
2020-01-23 21:33     ` David Ahern
2020-01-24 15:21       ` Jakub Kicinski
2020-01-24 15:36         ` Toke Høiland-Jørgensen
2020-01-26  1:43           ` David Ahern
2020-01-26  4:54             ` Alexei Starovoitov
2020-02-02 17:59               ` David Ahern
2020-01-26 12:49             ` Jesper Dangaard Brouer
2020-01-26 16:38               ` David Ahern
2020-01-26 22:17               ` Jakub Kicinski
2020-01-28 14:13                 ` Jesper Dangaard Brouer
2020-01-30 14:45                   ` Jakub Kicinski
2020-02-01 16:03                     ` Toke Høiland-Jørgensen
2020-02-02 17:48                       ` David Ahern
2020-01-26 22:11             ` Jakub Kicinski
2020-01-27  4:03               ` David Ahern
2020-01-27 14:16                 ` Jakub Kicinski
2020-01-28  3:43                   ` David Ahern [this message]
2020-01-28 13:57                     ` Jakub Kicinski
2020-02-01 16:24                       ` Toke Høiland-Jørgensen
2020-02-01 17:08                         ` Jakub Kicinski
2020-02-01 20:05                           ` Toke Høiland-Jørgensen
2020-02-02  4:15                             ` Jakub Kicinski
2020-02-03 19:56                               ` Toke Høiland-Jørgensen
2020-02-03 20:13                               ` Toke Høiland-Jørgensen
2020-02-03 22:15                                 ` Jesper Dangaard Brouer
2020-02-04 11:00                                   ` Toke Høiland-Jørgensen
2020-02-04 17:09                                     ` Jakub Kicinski
2020-02-05 15:30                                       ` Toke Høiland-Jørgensen
2020-02-02 17:45                           ` David Ahern
2020-02-02 19:12                             ` Jakub Kicinski
2020-02-02 17:43                       ` David Ahern
2020-02-02 19:31                         ` Jakub Kicinski
2020-02-02 21:51                           ` David Ahern
2020-02-01 15:59             ` Toke Høiland-Jørgensen
2020-02-02 17:54               ` David Ahern
2020-02-03 20:09                 ` Toke Høiland-Jørgensen
2020-01-23  1:42 ` [PATCH bpf-next 04/12] net: core: rename netif_receive_generic_xdp() to do_generic_xdp_core() David Ahern
2020-01-23  1:42 ` [PATCH bpf-next 05/12] tuntap: check tun_msg_ctl type at necessary places David Ahern
2020-01-23  1:42 ` [PATCH bpf-next 06/12] tun: move shared functions to if_tun.h David Ahern
2020-01-23  1:42 ` [PATCH bpf-next 07/12] vhost_net: user tap recvmsg api to access ptr ring David Ahern
2020-01-23  8:26   ` Michael S. Tsirkin
2020-01-23  1:42 ` [PATCH bpf-next 08/12] tuntap: remove usage of ptr ring in vhost_net David Ahern
2020-01-23  1:42 ` [PATCH bpf-next 09/12] tun: set egress XDP program David Ahern
2020-01-23  1:42 ` [PATCH bpf-next 10/12] tun: run XDP program in tx path David Ahern
2020-01-23  8:23   ` Michael S. Tsirkin
2020-01-24 13:36     ` Prashant Bhole
2020-01-24 13:44     ` Prashant Bhole
2020-01-23  1:42 ` [PATCH bpf-next 11/12] libbpf: Add egress XDP support David Ahern
2020-01-23  1:42 ` [PATCH bpf-next 12/12] samples/bpf: xdp1, add " David Ahern

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