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#include <bpf/bpf.h>
23#include <bpf/libbpf.h>
24
25#include "bpf_insn.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, err, ret = EXIT_FAILURE, filter_id = 0, prog_cnt = 0;
36	const char *link_pin_path = "/sys/fs/bpf/test_cgrp2_sock2";
37	struct bpf_link *link = NULL;
38	struct bpf_program *progs[2];
39	struct bpf_program *prog;
40	struct bpf_object *obj;
41
42	if (argc < 3)
43		return usage(argv[0]);
44
45	if (argc > 3)
46		filter_id = atoi(argv[3]);
47
48	cg_fd = open(argv[1], O_DIRECTORY | O_RDONLY);
49	if (cg_fd < 0) {
50		printf("Failed to open cgroup path: '%s'\n", strerror(errno));
51		return ret;
52	}
53
54	obj = bpf_object__open_file(argv[2], NULL);
55	if (libbpf_get_error(obj)) {
56		printf("ERROR: opening BPF object file failed\n");
57		return ret;
58	}
59
60	bpf_object__for_each_program(prog, obj) {
61		progs[prog_cnt] = prog;
62		prog_cnt++;
63	}
64
65	if (filter_id >= prog_cnt) {
66		printf("Invalid program id; program not found in file\n");
67		goto cleanup;
68	}
69
70	/* load BPF program */
71	if (bpf_object__load(obj)) {
72		printf("ERROR: loading BPF object file failed\n");
73		goto cleanup;
74	}
75
76	link = bpf_program__attach_cgroup(progs[filter_id], cg_fd);
77	if (libbpf_get_error(link)) {
78		printf("ERROR: bpf_program__attach failed\n");
79		link = NULL;
80		goto cleanup;
81	}
82
83	err = bpf_link__pin(link, link_pin_path);
84	if (err < 0) {
85		printf("ERROR: bpf_link__pin failed: %d\n", err);
86		goto cleanup;
 
 
87	}
88
89	ret = EXIT_SUCCESS;
90
91cleanup:
92	bpf_link__destroy(link);
93	bpf_object__close(obj);
94	return ret;
95}

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