tree 200d4b5fa31fe985d21d4c27f6a5ebcc7c3b3ae7
parent f9c8d19d6c7c15a59963f80ec47e68808914abd4
author Alexei Starovoitov <ast@fb.com> 1462502954 -0700
committer David S. Miller <davem@davemloft.net> 1462564914 -0400

samples/bpf: add 'pointer to packet' tests

parse_simple.c - packet parser exapmle with single length check that
filters out udp packets for port 9

parse_varlen.c - variable length parser that understand multiple vlan headers,
ipip, ipip6 and ip options to filter out udp or tcp packets on port 9.
The packet is parsed layer by layer with multitple length checks.

parse_ldabs.c - classic style of packet parsing using LD_ABS instruction.
Same functionality as parse_simple.

simple = 24.1Mpps per core
varlen = 22.7Mpps
ldabs  = 21.4Mpps

Parser with LD_ABS instructions is slower than full direct access parser
which does more packet accesses and checks.

These examples demonstrate the choice bpf program authors can make between
flexibility of the parser vs speed.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>