• Alexei Starovoitov's avatar
    bpf: add bpf_redirect() helper · 27b29f63
    Alexei Starovoitov authored
    Existing bpf_clone_redirect() helper clones skb before redirecting
    it to RX or TX of destination netdev.
    Introduce bpf_redirect() helper that does that without cloning.
    
    Benchmarked with two hosts using 10G ixgbe NICs.
    One host is doing line rate pktgen.
    Another host is configured as:
    $ tc qdisc add dev $dev ingress
    $ tc filter add dev $dev root pref 10 u32 match u32 0 0 flowid 1:2 \
       action bpf run object-file tcbpf1_kern.o section clone_redirect_xmit drop
    so it receives the packet on $dev and immediately xmits it on $dev + 1
    The section 'clone_redirect_xmit' in tcbpf1_kern.o file has the program
    that does bpf_clone_redirect() and performance is 2.0 Mpps
    
    $ tc filter add dev $dev root pref 10 u32 match u32 0 0 flowid 1:2 \
       action bpf run object-file tcbpf1_kern.o section redirect_xmit drop
    which is using bpf_redirect() - 2.4 Mpps
    
    and using cls_bpf with integrated actions as:
    $ tc filter add dev $dev root pref 10 \
      bpf run object-file tcbpf1_kern.o section redirect_xmit integ_act classid 1
    performance is 2.5 Mpps
    
    To summarize:
    u32+act_bpf using clone_redirect - 2.0 Mpps
    u32+act_bpf using redirect - 2.4 Mpps
    cls_bpf using redirect - 2.5 Mpps
    
    For comparison linux bridge in this setup is doing 2.1 Mpps
    and ixgbe rx + drop in ip_rcv - 7.8 Mpps
    Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
    Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
    Acked-by: default avatarJohn Fastabend <john.r.fastabend@intel.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    27b29f63
tcbpf1_kern.c 2.5 KB