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
Subject: Re: [bpf-next v3 8/9] bpf: Provide helper to do forwarding lookups in kernel FIB table
Date: Thu, 10 May 2018 09:31:58 +0200 [thread overview]
Message-ID: <20180510093158.08a7ed4b@redhat.com> (raw)
In-Reply-To: <20180510033427.20756-9-dsahern@gmail.com>
On Wed, 9 May 2018 20:34:26 -0700
David Ahern <dsahern@gmail.com> wrote:
> Provide a helper for doing a FIB and neighbor lookup in the kernel
> tables from an XDP program. The helper provides a fastpath for forwarding
> packets. If the packet is a local delivery or for any reason is not a
> simple lookup and forward, the packet continues up the stack.
>
> If it is to be forwarded, the forwarding can be done directly if the
> neighbor is already known. If the neighbor does not exist, the first
> few packets go up the stack for neighbor resolution. Once resolved, the
> xdp program provides the fast path.
>
> On successful lookup the nexthop dmac, current device smac and egress
> device index are returned.
>
> The API supports IPv4, IPv6 and MPLS protocols, but only IPv4 and IPv6
> are implemented in this patch. The API includes layer 4 parameters if
> the XDP program chooses to do deep packet inspection to allow compare
> against ACLs implemented as FIB rules.
>
> Header rewrite is left to the XDP program.
>
> The lookup takes 2 flags:
> - BPF_FIB_LOOKUP_DIRECT to do a lookup that bypasses FIB rules and goes
> straight to the table associated with the device (expert setting for
> those looking to maximize throughput)
>
> - BPF_FIB_LOOKUP_OUTPUT to do a lookup from the egress perspective.
> Default is an ingress lookup.
>
> Initial performance numbers collected by Jesper, forwarded packets/sec:
>
> Full stack XDP FIB lookup XDP Direct lookup
> IPv4 1,947,969 7,074,156 7,415,333
> IPv6 1,728,000 6,165,504 7,262,720
>
The "Full stack" tests were with netfilter modules unloaded. Default
setting with netfilter conntrack loaded and default Fedora firewall
rules, show around 700Kpps.
> These number are single CPU core forwarding on a Broadwell
> E5-1650 v4 @ 3.60GHz.
>
> Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
This helper is awesome, as it really shows how XDP is meant to work in
concert and cooperate with the existing network stack.
--
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 7:32 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 [this message]
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
2018-05-10 23:30 ` [bpf-next v3 0/9] bpf: Add helper to do FIB lookups Daniel Borkmann
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