LXR linux/samples/bpf/test_cgrp2

   1// SPDX-License-Identifier: GPL-2.0
   2/* eBPF example program:
   3 *
   4 * - Loads eBPF program
   5 *
   6 *   The eBPF program loads a filter from file and attaches the
   7 *   program to a cgroup using BPF_PROG_ATTACH
   8 */
   9
  10#define _GNU_SOURCE
  11
  12#include <stdio.h>
  13#include <stdlib.h>
  14#include <stddef.h>
  15#include <string.h>
  16#include <unistd.h>
  17#include <assert.h>
  18#include <errno.h>
  19#include <fcntl.h>
  20#include <net/if.h>
  21#include <linux/bpf.h>
  22
  23#include "libbpf.h"
  24#include "bpf_load.h"
  25
  26static int usage(const char *argv0)
  27{
  28        printf("Usage: %s cg-path filter-path [filter-id]\n", argv0);
  29        return EXIT_FAILURE;
  30}
  31
  32int main(int argc, char **argv)
  33{
  34        int cg_fd, ret, filter_id = 0;
  35
  36        if (argc < 3)
  37                return usage(argv[0]);
  38
  39        cg_fd = open(argv[1], O_DIRECTORY | O_RDONLY);
  40        if (cg_fd < 0) {
  41                printf("Failed to open cgroup path: '%s'\n", strerror(errno));
  42                return EXIT_FAILURE;
  43        }
  44
  45        if (load_bpf_file(argv[2]))
  46                return EXIT_FAILURE;
  47
  48        printf("Output from kernel verifier:\n%s\n-------\n", bpf_log_buf);
  49
  50        if (argc > 3)
  51                filter_id = atoi(argv[3]);
  52
  53        if (filter_id > prog_cnt) {
  54                printf("Invalid program id; program not found in file\n");
  55                return EXIT_FAILURE;
  56        }
  57
  58        ret = bpf_prog_attach(prog_fd[filter_id], cg_fd,
  59                              BPF_CGROUP_INET_SOCK_CREATE, 0);
  60        if (ret < 0) {
  61                printf("Failed to attach prog to cgroup: '%s'\n",
  62                       strerror(errno));
  63                return EXIT_FAILURE;
  64        }
  65
  66        return EXIT_SUCCESS;
  67}
  68