1. 29 Oct, 2016 1 commit
    • Daniel Borkmann's avatar
      bpf: fix samples to add fake KBUILD_MODNAME · 96a8eb1e
      Daniel Borkmann authored
      Some of the sample files are causing issues when they are loaded with tc
      and cls_bpf, meaning tc bails out while trying to parse the resulting ELF
      file as program/map/etc sections are not present, which can be easily
      spotted with readelf(1).
      
      Currently, BPF samples are including some of the kernel headers and mid
      term we should change them to refrain from this, really. When dynamic
      debugging is enabled, we bail out due to undeclared KBUILD_MODNAME, which
      is easily overlooked in the build as clang spills this along with other
      noisy warnings from various header includes, and llc still generates an
      ELF file with mentioned characteristics. For just playing around with BPF
      examples, this can be a bit of a hurdle to take.
      
      Just add a fake KBUILD_MODNAME as a band-aid to fix the issue, same is
      done in xdp*_kern samples already.
      
      Fixes: 65d472fb ("samples/bpf: add 'pointer to packet' tests")
      Fixes: 6afb1e28 ("samples/bpf: Add tunnel set/get tests.")
      Fixes: a3f74617 ("cgroup: bpf: Add an example to do cgroup checking in BPF")
      Reported-by: 's avatarChandrasekar Kannan <ckannan@console.to>
      Signed-off-by: 's avatarDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: 's avatarAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
      96a8eb1e
  2. 06 May, 2016 1 commit
    • 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