samples: bpf: Add BPF support for xdp_exception tracepoint

This would allow us to store stats for each XDP action, including their
per-CPU counts. Consolidating this here allows all redirect samples to
detect xdp_exception events.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-7-memxor@gmail.com
This commit is contained in:
Kumar Kartikeya Dwivedi 2021-08-21 05:49:54 +05:30 committed by Alexei Starovoitov
parent 1d930fd2cd
commit 451588764e

View file

@ -8,6 +8,7 @@
array_map rx_cnt SEC(".maps");
array_map redir_err_cnt SEC(".maps");
array_map exception_cnt SEC(".maps");
const volatile int nr_cpus = 0;
@ -110,3 +111,29 @@ int BPF_PROG(tp_xdp_redirect_map, const struct net_device *dev,
{
return xdp_redirect_collect_stat(dev->ifindex, err);
}
SEC("tp_btf/xdp_exception")
int BPF_PROG(tp_xdp_exception, const struct net_device *dev,
const struct bpf_prog *xdp, u32 act)
{
u32 cpu = bpf_get_smp_processor_id();
struct datarec *rec;
u32 key = act, idx;
if (!IN_SET(from_match, dev->ifindex))
return 0;
if (!IN_SET(to_match, dev->ifindex))
return 0;
if (key > XDP_REDIRECT)
key = XDP_REDIRECT + 1;
idx = key * nr_cpus + cpu;
rec = bpf_map_lookup_elem(&exception_cnt, &idx);
if (!rec)
return 0;
NO_TEAR_INC(rec->dropped);
return 0;
}