1/*
2 * Copyright (c) 2017 Carlo Marcelo Arenas Belón <carenas@gmail.com>
3 *
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17/*
18 * Very basic test for the RND* ioctls.
19 *
20 * Reads the entropy available from both /proc and the ioctl and compares
21 * they are similar enough (within a configured fuzz factor)
22 *
23 */
24
25#include <asm/types.h>
26#include <linux/random.h>
27#include <stdlib.h>
28#include "tst_test.h"
29
30static char *s_fuzz;
31static int fuzz = 2;
32static struct tst_option options[] = {
33	{"f:", &s_fuzz, "-f c     Fuzz factor for valid match (default 2)"},
34	{NULL, NULL, NULL}
35};
36static int fd;
37
38static void verify_ioctl(void)
39{
40	int cnt, pcnt;
41
42	SAFE_IOCTL(fd, RNDGETENTCNT, &cnt);
43	SAFE_FILE_SCANF("/proc/sys/kernel/random/entropy_avail", "%d", &pcnt);
44	tst_res(TINFO, "entropy value from ioctl: %d, proc: %d", cnt, pcnt);
45
46	if (abs(pcnt - cnt) <= fuzz)
47		tst_res(TPASS, "entropy value within expected parameters");
48	else
49		tst_res(TFAIL, "incorrect entropy value from ioctl");
50}
51
52static void setup(void)
53{
54	fd = SAFE_OPEN("/dev/urandom", O_RDONLY);
55	if (s_fuzz)
56		fuzz = SAFE_STRTOL(s_fuzz, 0, 4096);
57}
58
59static void cleanup(void)
60{
61	if (fd > 0)
62		SAFE_CLOSE(fd);
63}
64
65static struct tst_test test = {
66	.setup = setup,
67	.cleanup = cleanup,
68	.options = options,
69	.test_all = verify_ioctl,
70};
71