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

DEFINITIONS

1. SEC

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2018 Facebook */
   3 #include <stddef.h>
   4 #include <linux/bpf.h>
   5 #include <linux/types.h>
   6 #include "bpf_helpers.h"
   7 
   8 struct {
   9         __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
  10         __uint(max_entries, 1);
  11         __uint(map_flags, 0);
  12         __uint(key_size, sizeof(__u32));
  13         /* must be sizeof(__u32) for map in map */
  14         __uint(value_size, sizeof(__u32));
  15 } mim_array SEC(".maps");
  16 
  17 struct {
  18         __uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
  19         __uint(max_entries, 1);
  20         __uint(map_flags, 0);
  21         __uint(key_size, sizeof(int));
  22         /* must be sizeof(__u32) for map in map */
  23         __uint(value_size, sizeof(__u32));
  24 } mim_hash SEC(".maps");
  25 
  26 SEC("xdp_mimtest")
  27 int xdp_mimtest0(struct xdp_md *ctx)
  28 {
  29         int value = 123;
  30         int *value_p;
  31         int key = 0;
  32         void *map;
  33 
  34         map = bpf_map_lookup_elem(&mim_array, &key);
  35         if (!map)
  36                 return XDP_DROP;
  37 
  38         bpf_map_update_elem(map, &key, &value, 0);
  39         value_p = bpf_map_lookup_elem(map, &key);
  40         if (!value_p || *value_p != 123)
  41                 return XDP_DROP;
  42 
  43         map = bpf_map_lookup_elem(&mim_hash, &key);
  44         if (!map)
  45                 return XDP_DROP;
  46 
  47         bpf_map_update_elem(map, &key, &value, 0);
  48 
  49         return XDP_PASS;
  50 }
  51 
  52 int _version SEC("version") = 1;
  53 char _license[] SEC("license") = "GPL";