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
30 static char *s_fuzz;
31 static int fuzz = 2;
32 static struct tst_option options[] = {
33 {"f:", &s_fuzz, "-f c Fuzz factor for valid match (default 2)"},
34 {NULL, NULL, NULL}
35 };
36 static int fd;
37
verify_ioctl(void)38 static 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
setup(void)52 static 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
cleanup(void)59 static void cleanup(void)
60 {
61 if (fd > 0)
62 SAFE_CLOSE(fd);
63 }
64
65 static struct tst_test test = {
66 .setup = setup,
67 .cleanup = cleanup,
68 .options = options,
69 .test_all = verify_ioctl,
70 };
71