From: Jesper Dangaard Brouer <brouer@redhat.com>
To: David Ahern <dsahern@gmail.com>
Cc: netdev@vger.kernel.org, borkmann@iogearbox.net, ast@kernel.org,
davem@davemloft.net, shm@cumulusnetworks.com,
roopa@cumulusnetworks.com, toke@toke.dk,
john.fastabend@gmail.com, brouer@redhat.com,
Tariq Toukan <tariqt@mellanox.com>
Subject: Re: [bpf-next v3 9/9] samples/bpf: Add example of ipv4 and ipv6 forwarding in XDP
Date: Thu, 10 May 2018 09:22:51 +0200 [thread overview]
Message-ID: <20180510092251.2dc1c904@redhat.com> (raw)
In-Reply-To: <20180510033427.20756-10-dsahern@gmail.com>
On Wed, 9 May 2018 20:34:27 -0700
David Ahern <dsahern@gmail.com> wrote:
> Simple example of fast-path forwarding. It has a serious flaw
> in not verifying the egress device index supports XDP forwarding.
> If the egress device does not packets are dropped.
>
> Take this only as a simple example of fast-path forwarding.
>
> Signed-off-by: David Ahern <dsahern@gmail.com>
> Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
I agree that sample program have this flaw, but it should not stop this
patchset. We need to find a more reliable way of detecting/verifying
that an egress device supports XDP forwarding, from within the BPF prog.
As this sample program hints, we could do a lookup in the devmap, to
get this info(?)
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2018-05-10 7:22 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-10 3:34 [bpf-next v3 0/9] bpf: Add helper to do FIB lookups David Ahern
2018-05-10 3:34 ` [bpf-next v3 1/9] net/ipv6: Rename fib6_lookup to fib6_node_lookup David Ahern
2018-05-10 3:34 ` [bpf-next v3 2/9] net/ipv6: Rename rt6_multipath_select David Ahern
2018-05-10 3:34 ` [bpf-next v3 3/9] net/ipv6: Extract table lookup from ip6_pol_route David Ahern
2018-05-10 3:34 ` [bpf-next v3 4/9] net/ipv6: Refactor fib6_rule_action David Ahern
2018-05-10 3:34 ` [bpf-next v3 5/9] net/ipv6: Add fib6_lookup David Ahern
2018-05-10 3:34 ` [bpf-next v3 6/9] net/ipv6: Update fib6 tracepoint to take fib6_info David Ahern
2018-05-10 3:34 ` [bpf-next v3 7/9] net/ipv6: Add fib lookup stubs for use in bpf helper David Ahern
2018-05-10 3:34 ` [bpf-next v3 8/9] bpf: Provide helper to do forwarding lookups in kernel FIB table David Ahern
2018-05-10 7:31 ` Jesper Dangaard Brouer
2018-05-10 9:09 ` Toke Høiland-Jørgensen
2018-05-10 19:27 ` Mathieu Xhonneux
2018-05-11 6:30 ` David Ahern
2018-05-10 3:34 ` [bpf-next v3 9/9] samples/bpf: Add example of ipv4 and ipv6 forwarding in XDP David Ahern
2018-05-10 7:22 ` Jesper Dangaard Brouer [this message]
2018-05-10 23:30 ` [bpf-next v3 0/9] bpf: Add helper to do FIB lookups Daniel Borkmann
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