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 #include "../kselftest.h" 27 28 int set_tz(int min, int dst) 29 { 30 struct timezone tz; 31 32 tz.tz_minuteswest = min; 33 tz.tz_dsttime = dst; 34 35 return settimeofday(0, &tz); 36 } 37 38 int get_tz_min(void) 39 { 40 struct timezone tz; 41 struct timeval tv; 42 43 memset(&tz, 0, sizeof(tz)); 44 gettimeofday(&tv, &tz); 45 return tz.tz_minuteswest; 46 } 47 48 int get_tz_dst(void) 49 { 50 struct timezone tz; 51 struct timeval tv; 52 53 memset(&tz, 0, sizeof(tz)); 54 gettimeofday(&tv, &tz); 55 return tz.tz_dsttime; 56 } 57 58 int main(int argc, char **argv) 59 { 60 int i, ret; 61 int min, dst; 62 63 min = get_tz_min(); 64 dst = get_tz_dst(); 65 printf("tz_minuteswest started at %i, dst at %i\n", min, dst); 66 67 printf("Checking tz_minuteswest can be properly set: "); 68 for (i = -15*60; i < 15*60; i += 30) { 69 ret = set_tz(i, dst); 70 ret = get_tz_min(); 71 if (ret != i) { 72 printf("[FAILED] expected: %i got %i\n", i, ret); 73 goto err; 74 } 75 } 76 printf("[OK]\n"); 77 78 printf("Checking invalid tz_minuteswest values are caught: "); 79 80 if (!set_tz(-15*60-1, dst)) { 81 printf("[FAILED] %i didn't return failure!\n", -15*60-1); 82 goto err; 83 } 84 85 if (!set_tz(15*60+1, dst)) { 86 printf("[FAILED] %i didn't return failure!\n", 15*60+1); 87 goto err; 88 } 89 90 if (!set_tz(-24*60, dst)) { 91 printf("[FAILED] %i didn't return failure!\n", -24*60); 92 goto err; 93 } 94 95 if (!set_tz(24*60, dst)) { 96 printf("[FAILED] %i didn't return failure!\n", 24*60); 97 goto err; 98 } 99 100 printf("[OK]\n"); 101 102 set_tz(min, dst); 103 return ksft_exit_pass(); 104 105 err: 106 set_tz(min, dst); 107 return ksft_exit_fail(); 108 } 109