1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2017 Carlo Marcelo Arenas Belón <carenas@gmail.com>
4 */
5 /*
6 * Very basic test for the RND* ioctls.
7 *
8 * Reads the entropy available from both /proc and the ioctl and compares
9 * they are similar enough (within a configured fuzz factor)
10 *
11 */
12
13 #include <asm/types.h>
14 #include <linux/random.h>
15 #include <stdlib.h>
16 #include "tst_test.h"
17
18 static char *s_fuzz;
19 static int fuzz = 2;
20 static int fd;
21
verify_ioctl(void)22 static void verify_ioctl(void)
23 {
24 int cnt, pcnt;
25
26 SAFE_IOCTL(fd, RNDGETENTCNT, &cnt);
27 SAFE_FILE_SCANF("/proc/sys/kernel/random/entropy_avail", "%d", &pcnt);
28 tst_res(TINFO, "entropy value from ioctl: %d, proc: %d", cnt, pcnt);
29
30 if (abs(pcnt - cnt) <= fuzz)
31 tst_res(TPASS, "entropy value within expected parameters");
32 else
33 tst_res(TFAIL, "incorrect entropy value from ioctl");
34 }
35
setup(void)36 static void setup(void)
37 {
38 fd = SAFE_OPEN("/dev/urandom", O_RDONLY);
39 if (s_fuzz)
40 fuzz = SAFE_STRTOL(s_fuzz, 0, 4096);
41 }
42
cleanup(void)43 static void cleanup(void)
44 {
45 if (fd > 0)
46 SAFE_CLOSE(fd);
47 }
48
49 static struct tst_test test = {
50 .setup = setup,
51 .cleanup = cleanup,
52 .options = (struct tst_option[]) {
53 {"f:", &s_fuzz, "Fuzz factor for valid match (default 2)"},
54 {}
55 },
56 .test_all = verify_ioctl,
57 };
58