• Alexei Starovoitov's avatar
    samples/bpf: add 'pointer to packet' tests · 65d472fb
    Alexei Starovoitov authored
    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: 's avatarAlexei Starovoitov <ast@kernel.org>
    Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
    65d472fb