LXR linux/samples/bpf/tc_l2_redirect

   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 <stdlib.h>
   8#include <stdio.h>
   9#include <unistd.h>
  10#include <string.h>
  11#include <errno.h>
  12
  13#include <bpf/bpf.h>
  14
  15static void usage(void)
  16{
  17        printf("Usage: tc_l2_ipip_redirect [...]\n");
  18        printf("       -U <file>   Update an already pinned BPF array\n");
  19        printf("       -i <ifindex> Interface index\n");
  20        printf("       -h          Display this help\n");
  21}
  22
  23int main(int argc, char **argv)
  24{
  25        const char *pinned_file = NULL;
  26        int ifindex = -1;
  27        int array_key = 0;
  28        int array_fd = -1;
  29        int ret = -1;
  30        int opt;
  31
  32        while ((opt = getopt(argc, argv, "F:U:i:")) != -1) {
  33                switch (opt) {
  34                /* General args */
  35                case 'U':
  36                        pinned_file = optarg;
  37                        break;
  38                case 'i':
  39                        ifindex = atoi(optarg);
  40                        break;
  41                default:
  42                        usage();
  43                        goto out;
  44                }
  45        }
  46
  47        if (ifindex < 0 || !pinned_file) {
  48                usage();
  49                goto out;
  50        }
  51
  52        array_fd = bpf_obj_get(pinned_file);
  53        if (array_fd < 0) {
  54                fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
  55                        pinned_file, strerror(errno), errno);
  56                goto out;
  57        }
  58
  59        /* bpf_tunnel_key.remote_ipv4 expects host byte orders */
  60        ret = bpf_map_update_elem(array_fd, &array_key, &ifindex, 0);
  61        if (ret) {
  62                perror("bpf_map_update_elem");
  63                goto out;
  64        }
  65
  66out:
  67        if (array_fd != -1)
  68                close(array_fd);
  69        return ret;
  70}
  71