linux/include
David Ahern 87f5fc7e48 bpf: Provide helper to do forwarding lookups in kernel FIB table
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

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>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 00:10:57 +02:00
..
acpi xen: fixes for 4.17-rc1 2018-04-12 11:04:35 -07:00
asm-generic earlycon: Use a pointer table to fix __earlycon_table stride 2018-04-23 10:06:59 +02:00
clocksource ARM: SoC platform updates for 4.17 2018-04-05 21:21:08 -07:00
crypto
drm drm: Fix HDCP downstream dev count read 2018-04-16 12:10:48 -04:00
dt-bindings Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-21 16:32:48 -04:00
keys
kvm arm/arm64: KVM: Add PSCI version selection API 2018-04-20 16:32:23 +01:00
linux bpf: xdp: allow offloads to store into rx_queue_index 2018-05-09 18:04:36 +02:00
math-emu
media media updates for v4.17-rc1 2018-04-10 10:10:30 -07:00
memory
misc
net net/ipv6: Add fib lookup stubs for use in bpf helper 2018-05-11 00:10:57 +02:00
pcmcia
ras
rdma Merge candidates for 4.17 merge window 2018-04-06 17:35:43 -07:00
scsi scsi: core: remove reference to scsi_show_extd_sense() 2018-04-18 23:37:39 -04:00
soc soc: bcm2835: Make !RASPBERRYPI_FIRMWARE dummies return failure 2018-04-16 15:15:23 -07:00
sound ALSA: control: Hardening for potential Spectre v1 2018-04-25 10:37:46 +02:00
target
trace net/ipv6: Update fib6 tracepoint to take fib6_info 2018-05-11 00:10:57 +02:00
uapi bpf: Provide helper to do forwarding lookups in kernel FIB table 2018-05-11 00:10:57 +02:00
video
xen xen/sndif: Sync up with the canonical definition in Xen 2018-04-17 08:26:33 -04:00