LXR linux/tools/testing/selftests/bpf/progs/test_map_in

   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/bpf_helpers.h>
   7
   8struct {
   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
  17struct {
  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
  26SEC("xdp_mimtest")
  27int 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
  52int _version SEC("version") = 1;
  53char _license[] SEC("license") = "GPL";
  54