1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
 
 
 
 
  3 */
  4
  5#define _GNU_SOURCE
  6#include <stdio.h>
 
  7#include <unistd.h>
  8#include <bpf/bpf.h>
  9#include <bpf/libbpf.h>
 
 10#include "cgroup_helpers.h"
 11
 12#define CGROUP_PATH		"/my-cgroup"
 13
 14int main(int argc, char **argv)
 15{
 16	pid_t remote_pid, local_pid = getpid();
 17	int cg2 = -1, idx = 0, rc = 1;
 18	struct bpf_link *link = NULL;
 19	struct bpf_program *prog;
 20	struct bpf_object *obj;
 21	char filename[256];
 22	int map_fd[2];
 23
 24	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
 25	obj = bpf_object__open_file(filename, NULL);
 26	if (libbpf_get_error(obj)) {
 27		fprintf(stderr, "ERROR: opening BPF object file failed\n");
 28		return 0;
 29	}
 30
 31	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
 32	if (!prog) {
 33		printf("finding a prog in obj file failed\n");
 34		goto cleanup;
 35	}
 36
 37	/* load BPF program */
 38	if (bpf_object__load(obj)) {
 39		fprintf(stderr, "ERROR: loading BPF object file failed\n");
 40		goto cleanup;
 41	}
 42
 43	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "cgroup_map");
 44	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "perf_map");
 45	if (map_fd[0] < 0 || map_fd[1] < 0) {
 46		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
 47		goto cleanup;
 48	}
 49
 50	link = bpf_program__attach(prog);
 51	if (libbpf_get_error(link)) {
 52		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
 53		link = NULL;
 54		goto cleanup;
 55	}
 56
 57	if (setup_cgroup_environment())
 58		goto err;
 59
 60	cg2 = create_and_get_cgroup(CGROUP_PATH);
 61
 62	if (cg2 < 0)
 63		goto err;
 64
 65	if (bpf_map_update_elem(map_fd[0], &idx, &cg2, BPF_ANY)) {
 66		log_err("Adding target cgroup to map");
 67		goto err;
 68	}
 69
 70	if (join_cgroup(CGROUP_PATH))
 71		goto err;
 72
 73	/*
 74	 * The installed helper program catched the sync call, and should
 75	 * write it to the map.
 76	 */
 77
 78	sync();
 79	bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
 80
 81	if (local_pid != remote_pid) {
 82		fprintf(stderr,
 83			"BPF Helper didn't write correct PID to map, but: %d\n",
 84			remote_pid);
 85		goto err;
 86	}
 87
 88	/* Verify the negative scenario; leave the cgroup */
 89	if (join_cgroup("/"))
 90		goto err;
 91
 92	remote_pid = 0;
 93	bpf_map_update_elem(map_fd[1], &idx, &remote_pid, BPF_ANY);
 94
 95	sync();
 96	bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
 97
 98	if (local_pid == remote_pid) {
 99		fprintf(stderr, "BPF cgroup negative test did not work\n");
100		goto err;
101	}
102
103	rc = 0;
104
105err:
106	if (cg2 != -1)
107		close(cg2);
108
 
 
109	cleanup_cgroup_environment();
110
111cleanup:
112	bpf_link__destroy(link);
113	bpf_object__close(obj);
114	return rc;
115}

 
 1/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
 2 *
 3 * This program is free software; you can redistribute it and/or
 4 * modify it under the terms of version 2 of the GNU General Public
 5 * License as published by the Free Software Foundation.
 6 */
 7
 8#define _GNU_SOURCE
 9#include <stdio.h>
10#include <linux/bpf.h>
11#include <unistd.h>
12#include "libbpf.h"
13#include "bpf_load.h"
14#include <linux/bpf.h>
15#include "cgroup_helpers.h"
16
17#define CGROUP_PATH		"/my-cgroup"
18
19int main(int argc, char **argv)
20{
21	pid_t remote_pid, local_pid = getpid();
22	int cg2, idx = 0, rc = 0;
 
 
 
23	char filename[256];
 
24
25	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
26	if (load_bpf_file(filename)) {
27		printf("%s", bpf_log_buf);
28		return 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
29	}
30
31	if (setup_cgroup_environment())
32		goto err;
33
34	cg2 = create_and_get_cgroup(CGROUP_PATH);
35
36	if (!cg2)
37		goto err;
38
39	if (bpf_map_update_elem(map_fd[0], &idx, &cg2, BPF_ANY)) {
40		log_err("Adding target cgroup to map");
41		goto err;
42	}
43
44	if (join_cgroup(CGROUP_PATH))
45		goto err;
46
47	/*
48	 * The installed helper program catched the sync call, and should
49	 * write it to the map.
50	 */
51
52	sync();
53	bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
54
55	if (local_pid != remote_pid) {
56		fprintf(stderr,
57			"BPF Helper didn't write correct PID to map, but: %d\n",
58			remote_pid);
59		goto err;
60	}
61
62	/* Verify the negative scenario; leave the cgroup */
63	if (join_cgroup("/"))
64		goto err;
65
66	remote_pid = 0;
67	bpf_map_update_elem(map_fd[1], &idx, &remote_pid, BPF_ANY);
68
69	sync();
70	bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
71
72	if (local_pid == remote_pid) {
73		fprintf(stderr, "BPF cgroup negative test did not work\n");
74		goto err;
75	}
76
77	goto out;
 
78err:
79	rc = 1;
 
80
81out:
82	close(cg2);
83	cleanup_cgroup_environment();
 
 
 
 
84	return rc;
85}