1 /* Set tz value
2 * by: John Stultz <john.stultz@linaro.org>
3 * (C) Copyright Linaro 2016
4 * Licensed under the GPLv2
5 *
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <time.h>
21 #include <sys/time.h>
22 #include <sys/timex.h>
23 #include <string.h>
24 #include <signal.h>
25 #include <unistd.h>
26 #ifdef KTEST
27 #include "../kselftest.h"
28 #else
ksft_exit_pass(void)29 static inline int ksft_exit_pass(void)
30 {
31 exit(0);
32 }
ksft_exit_fail(void)33 static inline int ksft_exit_fail(void)
34 {
35 exit(1);
36 }
37 #endif
38
set_tz(int min,int dst)39 int set_tz(int min, int dst)
40 {
41 struct timezone tz;
42
43 tz.tz_minuteswest = min;
44 tz.tz_dsttime = dst;
45
46 return settimeofday(0, &tz);
47 }
48
get_tz_min(void)49 int get_tz_min(void)
50 {
51 struct timezone tz;
52 struct timeval tv;
53
54 memset(&tz, 0, sizeof(tz));
55 gettimeofday(&tv, &tz);
56 return tz.tz_minuteswest;
57 }
58
get_tz_dst(void)59 int get_tz_dst(void)
60 {
61 struct timezone tz;
62 struct timeval tv;
63
64 memset(&tz, 0, sizeof(tz));
65 gettimeofday(&tv, &tz);
66 return tz.tz_dsttime;
67 }
68
main(int argc,char ** argv)69 int main(int argc, char **argv)
70 {
71 int i, ret;
72 int min, dst;
73
74 min = get_tz_min();
75 dst = get_tz_dst();
76 printf("tz_minuteswest started at %i, dst at %i\n", min, dst);
77
78 printf("Checking tz_minuteswest can be properly set: ");
79 for (i = -15*60; i < 15*60; i += 30) {
80 ret = set_tz(i, dst);
81 ret = get_tz_min();
82 if (ret != i) {
83 printf("[FAILED] expected: %i got %i\n", i, ret);
84 goto err;
85 }
86 }
87 printf("[OK]\n");
88
89 printf("Checking invalid tz_minuteswest values are caught: ");
90
91 if (!set_tz(-15*60-1, dst)) {
92 printf("[FAILED] %i didn't return failure!\n", -15*60-1);
93 goto err;
94 }
95
96 if (!set_tz(15*60+1, dst)) {
97 printf("[FAILED] %i didn't return failure!\n", 15*60+1);
98 goto err;
99 }
100
101 if (!set_tz(-24*60, dst)) {
102 printf("[FAILED] %i didn't return failure!\n", -24*60);
103 goto err;
104 }
105
106 if (!set_tz(24*60, dst)) {
107 printf("[FAILED] %i didn't return failure!\n", 24*60);
108 goto err;
109 }
110
111 printf("[OK]\n");
112
113 set_tz(min, dst);
114 return ksft_exit_pass();
115
116 err:
117 set_tz(min, dst);
118 return ksft_exit_fail();
119 }
120