Eric Lee / smarc-fsl-linux-kernel

10 Jul, 2018

1 commit

  • b9626f45a   samples/bpf: Fix tc and ip paths in xdp2skb_meta.sh ... Browse Code »

    The below path error can occur:

    # ./xdp2skb_meta.sh --dev eth0 --list
    ./xdp2skb_meta.sh: line 61: /usr/sbin/tc: No such file or directory

    So just use command names instead of absolute paths of tc and ip.
    In addition, it allow callers to redefine $TC and $IP paths

    Fixes: 36e04a2d78d9 ("samples/bpf: xdp2skb_meta shows transferring info from XDP to SKB")
    Reviewed-by: Jesper Dangaard Brouer
    Signed-off-by: Taeung Song
    Acked-by: Jesper Dangaard Brouer
    Signed-off-by: Daniel Borkmann

    Taeung Song
     

11 Jan, 2018

1 commit

  • 36e04a2d7   samples/bpf: xdp2skb_meta shows transferring info from XDP to SKB ... Browse Code »

    Creating a bpf sample that shows howto use the XDP 'data_meta'
    infrastructure, created by Daniel Borkmann. Very few drivers support
    this feature, but I wanted a functional sample to begin with, when
    working on adding driver support.

    XDP data_meta is about creating a communication channel between BPF
    programs. This can be XDP tail-progs, but also other SKB based BPF
    hooks, like in this case the TC clsact hook. In this sample I show
    that XDP can store info named "mark", and TC/clsact chooses to use
    this info and store it into the skb->mark.

    It is a bit annoying that XDP and TC samples uses different tools/libs
    when attaching their BPF hooks. As the XDP and TC programs need to
    cooperate and agree on a struct-layout, it is best/easiest if the two
    programs can be contained within the same BPF restricted-C file.

    As the bpf-loader, I choose to not use bpf_load.c (or libbpf), but
    instead wrote a bash shell scripted named xdp2skb_meta.sh, which
    demonstrate howto use the iproute cmdline tools 'tc' and 'ip' for
    loading BPF programs. To make it easy for first time users, the shell
    script have command line parsing, and support --verbose and --dry-run
    mode, if you just want to see/learn the tc+ip command syntax:

    # ./xdp2skb_meta.sh --dev ixgbe2 --dry-run
    # Dry-run mode: enable VERBOSE and don't call TC+IP
    tc qdisc del dev ixgbe2 clsact
    tc qdisc add dev ixgbe2 clsact
    tc filter add dev ixgbe2 ingress prio 1 handle 1 bpf da obj ./xdp2skb_meta_kern.o sec tc_mark
    # Flush XDP on device: ixgbe2
    ip link set dev ixgbe2 xdp off
    ip link set dev ixgbe2 xdp obj ./xdp2skb_meta_kern.o sec xdp_mark

    Signed-off-by: Jesper Dangaard Brouer
    Signed-off-by: Daniel Borkmann

    Jesper Dangaard Brouer