1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
// SPDX-License-Identifier: GPL-2.0
/* eBPF example program:
*
* - Loads eBPF program
*
* The eBPF program loads a filter from file and attaches the
* program to a cgroup using BPF_PROG_ATTACH
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <linux/bpf.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "bpf_insn.h"
static int usage(const char *argv0)
{
printf("Usage: %s cg-path filter-path [filter-id]\n", argv0);
return EXIT_FAILURE;
}
int main(int argc, char **argv)
{
int cg_fd, err, ret = EXIT_FAILURE, filter_id = 0, prog_cnt = 0;
const char *link_pin_path = "/sys/fs/bpf/test_cgrp2_sock2";
struct bpf_link *link = NULL;
struct bpf_program *progs[2];
struct bpf_program *prog;
struct bpf_object *obj;
if (argc < 3)
return usage(argv[0]);
if (argc > 3)
filter_id = atoi(argv[3]);
cg_fd = open(argv[1], O_DIRECTORY | O_RDONLY);
if (cg_fd < 0) {
printf("Failed to open cgroup path: '%s'\n", strerror(errno));
return ret;
}
obj = bpf_object__open_file(argv[2], NULL);
if (libbpf_get_error(obj)) {
printf("ERROR: opening BPF object file failed\n");
return ret;
}
bpf_object__for_each_program(prog, obj) {
progs[prog_cnt] = prog;
prog_cnt++;
}
if (filter_id >= prog_cnt) {
printf("Invalid program id; program not found in file\n");
goto cleanup;
}
/* load BPF program */
if (bpf_object__load(obj)) {
printf("ERROR: loading BPF object file failed\n");
goto cleanup;
}
link = bpf_program__attach_cgroup(progs[filter_id], cg_fd);
if (libbpf_get_error(link)) {
printf("ERROR: bpf_program__attach failed\n");
link = NULL;
goto cleanup;
}
err = bpf_link__pin(link, link_pin_path);
if (err < 0) {
printf("ERROR: bpf_link__pin failed: %d\n", err);
goto cleanup;
}
ret = EXIT_SUCCESS;
cleanup:
bpf_link__destroy(link);
bpf_object__close(obj);
return ret;
}
|
