tools/testing/selftests/bpf/progs/netcnt_prog.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bpf.h>
   3 #include <linux/version.h>
   4
   5 #include <bpf/bpf_helpers.h>
   6 #include "netcnt_common.h"
   7
   8 #define MAX_BPS (3 * 1024 * 1024)
   9
  10 #define REFRESH_TIME_NS 100000000
  11 #define NS_PER_SEC      1000000000
  12
  13 struct {
  14         __uint(type, BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
  15         __type(key, struct bpf_cgroup_storage_key);
  16         __type(value, union percpu_net_cnt);
  17 } percpu_netcnt SEC(".maps");
  18
  19 struct {
  20         __uint(type, BPF_MAP_TYPE_CGROUP_STORAGE);
  21         __type(key, struct bpf_cgroup_storage_key);
  22         __type(value, union net_cnt);
  23 } netcnt SEC(".maps");
  24
  25 SEC("cgroup/skb")
  26 int bpf_nextcnt(struct __sk_buff *skb)
  27 {
  28         union percpu_net_cnt *percpu_cnt;
  29         union net_cnt *cnt;
  30         __u64 ts, dt;
  31         int ret;
  32
  33         cnt = bpf_get_local_storage(&netcnt, 0);
  34         percpu_cnt = bpf_get_local_storage(&percpu_netcnt, 0);
  35
  36         percpu_cnt->packets++;
  37         percpu_cnt->bytes += skb->len;
  38
  39         if (percpu_cnt->packets > MAX_PERCPU_PACKETS) {
  40                 __sync_fetch_and_add(&cnt->packets,
  41                                      percpu_cnt->packets);
  42                 percpu_cnt->packets = 0;
  43
  44                 __sync_fetch_and_add(&cnt->bytes,
  45                                      percpu_cnt->bytes);
  46                 percpu_cnt->bytes = 0;
  47         }
  48
  49         ts = bpf_ktime_get_ns();
  50         dt = ts - percpu_cnt->prev_ts;
  51
  52         dt *= MAX_BPS;
  53         dt /= NS_PER_SEC;
  54
  55         if (cnt->bytes + percpu_cnt->bytes - percpu_cnt->prev_bytes < dt)
  56                 ret = 1;
  57         else
  58                 ret = 0;
  59
  60         if (dt > REFRESH_TIME_NS) {
  61                 percpu_cnt->prev_ts = ts;
  62                 percpu_cnt->prev_packets = cnt->packets;
  63                 percpu_cnt->prev_bytes = cnt->bytes;
  64         }
  65
  66         return !!ret;
  67 }
  68
  69 char _license[] SEC("license") = "GPL";