LXR linux/samples/bpf/test_cgrp2_array

   1// SPDX-License-Identifier: GPL-2.0-only
   2/* Copyright (c) 2016 Facebook
   3 */
   4#include <linux/unistd.h>
   5#include <linux/bpf.h>
   6
   7#include <stdio.h>
   8#include <stdint.h>
   9#include <unistd.h>
  10#include <string.h>
  11#include <errno.h>
  12#include <fcntl.h>
  13
  14#include <bpf/bpf.h>
  15
  16static void usage(void)
  17{
  18        printf("Usage: test_cgrp2_array_pin [...]\n");
  19        printf("       -F <file>   File to pin an BPF cgroup array\n");
  20        printf("       -U <file>   Update an already pinned BPF cgroup array\n");
  21        printf("       -v <value>  Full path of the cgroup2\n");
  22        printf("       -h          Display this help\n");
  23}
  24
  25int main(int argc, char **argv)
  26{
  27        const char *pinned_file = NULL, *cg2 = NULL;
  28        int create_array = 1;
  29        int array_key = 0;
  30        int array_fd = -1;
  31        int cg2_fd = -1;
  32        int ret = -1;
  33        int opt;
  34
  35        while ((opt = getopt(argc, argv, "F:U:v:")) != -1) {
  36                switch (opt) {
  37                /* General args */
  38                case 'F':
  39                        pinned_file = optarg;
  40                        break;
  41                case 'U':
  42                        pinned_file = optarg;
  43                        create_array = 0;
  44                        break;
  45                case 'v':
  46                        cg2 = optarg;
  47                        break;
  48                default:
  49                        usage();
  50                        goto out;
  51                }
  52        }
  53
  54        if (!cg2 || !pinned_file) {
  55                usage();
  56                goto out;
  57        }
  58
  59        cg2_fd = open(cg2, O_RDONLY);
  60        if (cg2_fd < 0) {
  61                fprintf(stderr, "open(%s,...): %s(%d)\n",
  62                        cg2, strerror(errno), errno);
  63                goto out;
  64        }
  65
  66        if (create_array) {
  67                array_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,
  68                                          sizeof(uint32_t), sizeof(uint32_t),
  69                                          1, 0);
  70                if (array_fd < 0) {
  71                        fprintf(stderr,
  72                                "bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,...): %s(%d)\n",
  73                                strerror(errno), errno);
  74                        goto out;
  75                }
  76        } else {
  77                array_fd = bpf_obj_get(pinned_file);
  78                if (array_fd < 0) {
  79                        fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
  80                                pinned_file, strerror(errno), errno);
  81                        goto out;
  82                }
  83        }
  84
  85        ret = bpf_map_update_elem(array_fd, &array_key, &cg2_fd, 0);
  86        if (ret) {
  87                perror("bpf_map_update_elem");
  88                goto out;
  89        }
  90
  91        if (create_array) {
  92                ret = bpf_obj_pin(array_fd, pinned_file);
  93                if (ret) {
  94                        fprintf(stderr, "bpf_obj_pin(..., %s): %s(%d)\n",
  95                                pinned_file, strerror(errno), errno);
  96                        goto out;
  97                }
  98        }
  99
 100out:
 101        if (array_fd != -1)
 102                close(array_fd);
 103        if (cg2_fd != -1)
 104                close(cg2_fd);
 105        return ret;
 106}
 107