linux-bl808/net
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
..
6lowpan
9p net/9p: correct the variable name in v9fs_get_trans_by_name() comment 2018-05-07 23:38:15 -04:00
802
8021q vlan: correct the file path in vlan_dev_change_flags() comment 2018-05-07 23:37:30 -04:00
appletalk
atm
ax25
batman-adv
bluetooth
bpf
bridge
caif
can
ceph
core bpf: Provide helper to do forwarding lookups in kernel FIB table 2018-05-11 00:10:57 +02:00
dcb
dccp
decnet
dns_resolver
dsa
ethernet net: core: rework basic flow dissection helper 2018-05-08 00:02:36 -04:00
hsr
ieee802154
ife
ipv4 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-05-07 23:56:32 -04:00
ipv6 net/ipv6: Add fib lookup stubs for use in bpf helper 2018-05-11 00:10:57 +02:00
iucv
kcm
key
l2tp
l3mdev
lapb
llc
mac80211
mac802154
mpls
ncsi
netfilter
netlabel
netlink
netrom
nfc
nsh
openvswitch
packet
phonet
psample
qrtr
rds
rfkill
rose
rxrpc
sched
sctp
smc
strparser
sunrpc
switchdev
tipc
tls
unix
vmw_vsock
wimax
wireless
x25
xdp xsk: fix 64-bit division 2018-05-09 18:12:21 +02:00
xfrm
compat.c
Kconfig
Makefile
socket.c
sysctl_net.c