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

DEFINITIONS

1. SEC

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bpf.h>
   3 #include <linux/version.h>
   4 
   5 #include "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, struct 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, struct net_cnt);
  23 } netcnt SEC(".maps");
  24 
  25 SEC("cgroup/skb")
  26 int bpf_nextcnt(struct __sk_buff *skb)
  27 {
  28         struct percpu_net_cnt *percpu_cnt;
  29         char fmt[] = "%d %llu %llu\n";
  30         struct net_cnt *cnt;
  31         __u64 ts, dt;
  32         int ret;
  33 
  34         cnt = bpf_get_local_storage(&netcnt, 0);
  35         percpu_cnt = bpf_get_local_storage(&percpu_netcnt, 0);
  36 
  37         percpu_cnt->packets++;
  38         percpu_cnt->bytes += skb->len;
  39 
  40         if (percpu_cnt->packets > MAX_PERCPU_PACKETS) {
  41                 __sync_fetch_and_add(&cnt->packets,
  42                                      percpu_cnt->packets);
  43                 percpu_cnt->packets = 0;
  44 
  45                 __sync_fetch_and_add(&cnt->bytes,
  46                                      percpu_cnt->bytes);
  47                 percpu_cnt->bytes = 0;
  48         }
  49 
  50         ts = bpf_ktime_get_ns();
  51         dt = ts - percpu_cnt->prev_ts;
  52 
  53         dt *= MAX_BPS;
  54         dt /= NS_PER_SEC;
  55 
  56         if (cnt->bytes + percpu_cnt->bytes - percpu_cnt->prev_bytes < dt)
  57                 ret = 1;
  58         else
  59                 ret = 0;
  60 
  61         if (dt > REFRESH_TIME_NS) {
  62                 percpu_cnt->prev_ts = ts;
  63                 percpu_cnt->prev_packets = cnt->packets;
  64                 percpu_cnt->prev_bytes = cnt->bytes;
  65         }
  66 
  67         return !!ret;
  68 }
  69 
  70 char _license[] SEC("license") = "GPL";
  71 __u32 _version SEC("version") = LINUX_VERSION_CODE;