1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /* Copyright (c) 2017 Facebook
3*4882a593Smuzhiyun */
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <stdio.h>
6*4882a593Smuzhiyun #include <stdlib.h>
7*4882a593Smuzhiyun #include <string.h>
8*4882a593Smuzhiyun #include <errno.h>
9*4882a593Smuzhiyun #include <assert.h>
10*4882a593Smuzhiyun #include <sys/time.h>
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun #include <linux/bpf.h>
13*4882a593Smuzhiyun #include <bpf/bpf.h>
14*4882a593Smuzhiyun #include <bpf/libbpf.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun #include "cgroup_helpers.h"
17*4882a593Smuzhiyun #include "bpf_rlimit.h"
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun #define DEV_CGROUP_PROG "./dev_cgroup.o"
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun #define TEST_CGROUP "/test-bpf-based-device-cgroup/"
22*4882a593Smuzhiyun
main(int argc,char ** argv)23*4882a593Smuzhiyun int main(int argc, char **argv)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun struct bpf_object *obj;
26*4882a593Smuzhiyun int error = EXIT_FAILURE;
27*4882a593Smuzhiyun int prog_fd, cgroup_fd;
28*4882a593Smuzhiyun __u32 prog_cnt;
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun if (bpf_prog_load(DEV_CGROUP_PROG, BPF_PROG_TYPE_CGROUP_DEVICE,
31*4882a593Smuzhiyun &obj, &prog_fd)) {
32*4882a593Smuzhiyun printf("Failed to load DEV_CGROUP program\n");
33*4882a593Smuzhiyun goto out;
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);
37*4882a593Smuzhiyun if (cgroup_fd < 0) {
38*4882a593Smuzhiyun printf("Failed to create test cgroup\n");
39*4882a593Smuzhiyun goto out;
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun /* Attach bpf program */
43*4882a593Smuzhiyun if (bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_DEVICE, 0)) {
44*4882a593Smuzhiyun printf("Failed to attach DEV_CGROUP program");
45*4882a593Smuzhiyun goto err;
46*4882a593Smuzhiyun }
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun if (bpf_prog_query(cgroup_fd, BPF_CGROUP_DEVICE, 0, NULL, NULL,
49*4882a593Smuzhiyun &prog_cnt)) {
50*4882a593Smuzhiyun printf("Failed to query attached programs");
51*4882a593Smuzhiyun goto err;
52*4882a593Smuzhiyun }
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun /* All operations with /dev/zero and and /dev/urandom are allowed,
55*4882a593Smuzhiyun * everything else is forbidden.
56*4882a593Smuzhiyun */
57*4882a593Smuzhiyun assert(system("rm -f /tmp/test_dev_cgroup_null") == 0);
58*4882a593Smuzhiyun assert(system("mknod /tmp/test_dev_cgroup_null c 1 3"));
59*4882a593Smuzhiyun assert(system("rm -f /tmp/test_dev_cgroup_null") == 0);
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun /* /dev/zero is whitelisted */
62*4882a593Smuzhiyun assert(system("rm -f /tmp/test_dev_cgroup_zero") == 0);
63*4882a593Smuzhiyun assert(system("mknod /tmp/test_dev_cgroup_zero c 1 5") == 0);
64*4882a593Smuzhiyun assert(system("rm -f /tmp/test_dev_cgroup_zero") == 0);
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun assert(system("dd if=/dev/urandom of=/dev/zero count=64") == 0);
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun /* src is allowed, target is forbidden */
69*4882a593Smuzhiyun assert(system("dd if=/dev/urandom of=/dev/full count=64"));
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun /* src is forbidden, target is allowed */
72*4882a593Smuzhiyun assert(system("dd if=/dev/random of=/dev/zero count=64"));
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun error = 0;
75*4882a593Smuzhiyun printf("test_dev_cgroup:PASS\n");
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun err:
78*4882a593Smuzhiyun cleanup_cgroup_environment();
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun out:
81*4882a593Smuzhiyun return error;
82*4882a593Smuzhiyun }
83