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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 #include <linux/bpf.h>
   4 #include <bpf/bpf_helpers.h>
   5
   6 struct inner_map {
   7         __uint(type, BPF_MAP_TYPE_ARRAY);
   8         __uint(max_entries, 5);
   9         __type(key, int);
  10         __type(value, int);
  11 } inner_map1 SEC(".maps");
  12
  13 struct outer_map {
  14         __uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
  15         __uint(max_entries, 3);
  16         __type(key, int);
  17         __array(values, struct inner_map);
  18 } outer_map1 SEC(".maps") = {
  19         .values = {
  20                 [2] = &inner_map1,
  21         },
  22 };
  23
  24 SEC("raw_tp/sys_enter")
  25 int handle__sys_enter(void *ctx)
  26 {
  27         int outer_key = 2, inner_key = 3;
  28         int *val;
  29         void *map;
  30
  31         map = bpf_map_lookup_elem(&outer_map1, &outer_key);
  32         if (!map)
  33                 return 1;
  34
  35         val = bpf_map_lookup_elem(map, &inner_key);
  36         if (!val)
  37                 return 1;
  38
  39         if (*val == 1)
  40                 *val = 2;
  41
  42         return 0;
  43 }
  44
  45 char _license[] SEC("license") = "GPL";