blob: a9277b118c330b09f3c253785d20999d02c6410f [file] [log] [blame]
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
David Ahern554ae6e2016-12-01 08:48:08 -08002/* 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>
Jakub Kicinski8d930452018-05-14 22:35:03 -070022#include <bpf/bpf.h>
David Ahern554ae6e2016-12-01 08:48:08 -080023
Jakub Kicinski8d930452018-05-14 22:35:03 -070024#include "bpf_insn.h"
David Ahern554ae6e2016-12-01 08:48:08 -080025#include "bpf_load.h"
26
27static int usage(const char *argv0)
28{
29 printf("Usage: %s cg-path filter-path [filter-id]\n", argv0);
30 return EXIT_FAILURE;
31}
32
33int main(int argc, char **argv)
34{
35 int cg_fd, ret, filter_id = 0;
36
37 if (argc < 3)
38 return usage(argv[0]);
39
40 cg_fd = open(argv[1], O_DIRECTORY | O_RDONLY);
41 if (cg_fd < 0) {
42 printf("Failed to open cgroup path: '%s'\n", strerror(errno));
43 return EXIT_FAILURE;
44 }
45
46 if (load_bpf_file(argv[2]))
47 return EXIT_FAILURE;
48
49 printf("Output from kernel verifier:\n%s\n-------\n", bpf_log_buf);
50
51 if (argc > 3)
52 filter_id = atoi(argv[3]);
53
Dan Carpenteree583012018-07-13 18:05:37 +030054 if (filter_id >= prog_cnt) {
David Ahern554ae6e2016-12-01 08:48:08 -080055 printf("Invalid program id; program not found in file\n");
56 return EXIT_FAILURE;
57 }
58
59 ret = bpf_prog_attach(prog_fd[filter_id], cg_fd,
Alexei Starovoitov7f677632017-02-10 20:28:24 -080060 BPF_CGROUP_INET_SOCK_CREATE, 0);
David Ahern554ae6e2016-12-01 08:48:08 -080061 if (ret < 0) {
62 printf("Failed to attach prog to cgroup: '%s'\n",
63 strerror(errno));
64 return EXIT_FAILURE;
65 }
66
67 return EXIT_SUCCESS;
68}