1 /* $NetBSD: time.c,v 1.9 2025/01/26 16:25:25 christos Exp $ */ 2 3 /* 4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC") 5 * 6 * SPDX-License-Identifier: MPL-2.0 7 * 8 * This Source Code Form is subject to the terms of the Mozilla Public 9 * License, v. 2.0. If a copy of the MPL was not distributed with this 10 * file, you can obtain one at https://mozilla.org/MPL/2.0/. 11 * 12 * See the COPYRIGHT file distributed with this work for additional 13 * information regarding copyright ownership. 14 */ 15 16 /*! \file */ 17 18 #include <ctype.h> 19 #include <inttypes.h> 20 #include <stdio.h> 21 #include <time.h> 22 23 #include <isc/region.h> 24 #include <isc/result.h> 25 #include <isc/serial.h> 26 #include <isc/stdtime.h> 27 #include <isc/string.h> 28 #include <isc/util.h> 29 30 #include <dns/time.h> 31 32 static const int days[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; 33 34 isc_result_t 35 dns_time64_totext(int64_t t, isc_buffer_t *target) { 36 struct tm tm; 37 char buf[sizeof("!!!!!!YYYY!!!!!!!!MM!!!!!!!!DD!!!!!!!!HH!!!!!!!!MM!!!!" 38 "!!!!SS")]; 39 int secs; 40 unsigned int l; 41 isc_region_t region; 42 43 /* 44 * Warning. Do NOT use arguments with side effects with these macros. 45 */ 46 #define is_leap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) 47 #define year_secs(y) ((is_leap(y) ? 366 : 365) * 86400) 48 #define month_secs(m, y) ((days[m] + ((m == 1 && is_leap(y)) ? 1 : 0)) * 86400) 49 50 tm.tm_year = 70; 51 while (t < 0) { 52 if (tm.tm_year == 0) { 53 return ISC_R_RANGE; 54 } 55 tm.tm_year--; 56 secs = year_secs(tm.tm_year + 1900); 57 t += secs; 58 } 59 while ((secs = year_secs(tm.tm_year + 1900)) <= t) { 60 t -= secs; 61 tm.tm_year++; 62 if (tm.tm_year + 1900 > 9999) { 63 return ISC_R_RANGE; 64 } 65 } 66 tm.tm_mon = 0; 67 while ((secs = month_secs(tm.tm_mon, tm.tm_year + 1900)) <= t) { 68 t -= secs; 69 tm.tm_mon++; 70 } 71 tm.tm_mday = 1; 72 while (86400 <= t) { 73 t -= 86400; 74 tm.tm_mday++; 75 } 76 tm.tm_hour = 0; 77 while (3600 <= t) { 78 t -= 3600; 79 tm.tm_hour++; 80 } 81 tm.tm_min = 0; 82 while (60 <= t) { 83 t -= 60; 84 tm.tm_min++; 85 } 86 tm.tm_sec = (int)t; 87 /* yyyy mm dd HH MM SS */ 88 snprintf(buf, sizeof(buf), "%04d%02d%02d%02d%02d%02d", 89 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, 90 tm.tm_min, tm.tm_sec); 91 92 isc_buffer_availableregion(target, ®ion); 93 l = strlen(buf); 94 95 if (l > region.length) { 96 return ISC_R_NOSPACE; 97 } 98 99 memmove(region.base, buf, l); 100 isc_buffer_add(target, l); 101 return ISC_R_SUCCESS; 102 } 103 104 int64_t 105 dns_time64_from32(uint32_t value) { 106 isc_stdtime_t now = isc_stdtime_now(); 107 int64_t start; 108 int64_t t; 109 110 /* 111 * Adjust the time to the closest epoch. This should be changed 112 * to use a 64-bit counterpart to isc_stdtime_now() if one ever 113 * is defined, but even the current code is good until the year 114 * 2106. 115 */ 116 117 start = (int64_t)now; 118 if (isc_serial_gt(value, now)) { 119 t = start + (value - now); 120 } else { 121 t = start - (now - value); 122 } 123 124 return t; 125 } 126 127 isc_result_t 128 dns_time32_totext(uint32_t value, isc_buffer_t *target) { 129 return dns_time64_totext(dns_time64_from32(value), target); 130 } 131 132 isc_result_t 133 dns_time64_fromtext(const char *source, int64_t *target) { 134 int year, month, day, hour, minute, second; 135 int64_t value; 136 int secs; 137 int i; 138 139 #define RANGE(min, max, value) \ 140 do { \ 141 if (value < (min) || value > (max)) \ 142 return ((ISC_R_RANGE)); \ 143 } while (0) 144 145 if (strlen(source) != 14U) { 146 return DNS_R_SYNTAX; 147 } 148 /* 149 * Confirm the source only consists digits. sscanf() allows some 150 * minor exceptions. 151 */ 152 for (i = 0; i < 14; i++) { 153 if (!isdigit((unsigned char)source[i])) { 154 return DNS_R_SYNTAX; 155 } 156 } 157 if (sscanf(source, "%4d%2d%2d%2d%2d%2d", &year, &month, &day, &hour, 158 &minute, &second) != 6) 159 { 160 return DNS_R_SYNTAX; 161 } 162 163 RANGE(0, 9999, year); 164 RANGE(1, 12, month); 165 RANGE(1, days[month - 1] + ((month == 2 && is_leap(year)) ? 1 : 0), 166 day); 167 #ifdef __COVERITY__ 168 /* 169 * Use a simplified range to silence Coverity warning (in 170 * arithmetic with day below). 171 */ 172 RANGE(1, 31, day); 173 #endif /* __COVERITY__ */ 174 175 RANGE(0, 23, hour); 176 RANGE(0, 59, minute); 177 RANGE(0, 60, second); /* 60 == leap second. */ 178 179 /* 180 * Calculate seconds from epoch. 181 * Note: this uses a idealized calendar. 182 */ 183 value = second + (60 * minute) + (3600 * hour) + ((day - 1) * 86400); 184 for (i = 0; i < (month - 1); i++) { 185 value += days[i] * 86400; 186 } 187 if (is_leap(year) && month > 2) { 188 value += 86400; 189 } 190 if (year < 1970) { 191 for (i = 1969; i >= year; i--) { 192 secs = (is_leap(i) ? 366 : 365) * 86400; 193 value -= secs; 194 } 195 } else { 196 for (i = 1970; i < year; i++) { 197 secs = (is_leap(i) ? 366 : 365) * 86400; 198 value += secs; 199 } 200 } 201 202 *target = value; 203 return ISC_R_SUCCESS; 204 } 205 206 isc_result_t 207 dns_time32_fromtext(const char *source, uint32_t *target) { 208 int64_t value64; 209 isc_result_t result; 210 result = dns_time64_fromtext(source, &value64); 211 if (result != ISC_R_SUCCESS) { 212 return result; 213 } 214 *target = (uint32_t)value64; 215 216 return ISC_R_SUCCESS; 217 } 218