1 /* $NetBSD: time.c,v 1.1 2024/02/18 20:57:34 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/print.h>
24 #include <isc/region.h>
25 #include <isc/serial.h>
26 #include <isc/stdtime.h>
27 #include <isc/string.h> /* Required for HP/UX (and others?) */
28 #include <isc/util.h>
29
30 #include <dns/result.h>
31 #include <dns/time.h>
32
33 static const int days[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
34
35 isc_result_t
dns_time64_totext(int64_t t,isc_buffer_t * target)36 dns_time64_totext(int64_t t, isc_buffer_t *target) {
37 struct tm tm;
38 char buf[sizeof("!!!!!!YYYY!!!!!!!!MM!!!!!!!!DD!!!!!!!!HH!!!!!!!!MM!!!!"
39 "!!!!SS")];
40 int secs;
41 unsigned int l;
42 isc_region_t region;
43
44 /*
45 * Warning. Do NOT use arguments with side effects with these macros.
46 */
47 #define is_leap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
48 #define year_secs(y) ((is_leap(y) ? 366 : 365) * 86400)
49 #define month_secs(m, y) ((days[m] + ((m == 1 && is_leap(y)) ? 1 : 0)) * 86400)
50
51 tm.tm_year = 70;
52 while (t < 0) {
53 if (tm.tm_year == 0) {
54 return (ISC_R_RANGE);
55 }
56 tm.tm_year--;
57 secs = year_secs(tm.tm_year + 1900);
58 t += secs;
59 }
60 while ((secs = year_secs(tm.tm_year + 1900)) <= t) {
61 t -= secs;
62 tm.tm_year++;
63 if (tm.tm_year + 1900 > 9999) {
64 return (ISC_R_RANGE);
65 }
66 }
67 tm.tm_mon = 0;
68 while ((secs = month_secs(tm.tm_mon, tm.tm_year + 1900)) <= t) {
69 t -= secs;
70 tm.tm_mon++;
71 }
72 tm.tm_mday = 1;
73 while (86400 <= t) {
74 t -= 86400;
75 tm.tm_mday++;
76 }
77 tm.tm_hour = 0;
78 while (3600 <= t) {
79 t -= 3600;
80 tm.tm_hour++;
81 }
82 tm.tm_min = 0;
83 while (60 <= t) {
84 t -= 60;
85 tm.tm_min++;
86 }
87 tm.tm_sec = (int)t;
88 /* yyyy mm dd HH MM SS */
89 snprintf(buf, sizeof(buf), "%04d%02d%02d%02d%02d%02d",
90 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
91 tm.tm_min, tm.tm_sec);
92
93 isc_buffer_availableregion(target, ®ion);
94 l = strlen(buf);
95
96 if (l > region.length) {
97 return (ISC_R_NOSPACE);
98 }
99
100 memmove(region.base, buf, l);
101 isc_buffer_add(target, l);
102 return (ISC_R_SUCCESS);
103 }
104
105 int64_t
dns_time64_from32(uint32_t value)106 dns_time64_from32(uint32_t value) {
107 isc_stdtime_t now;
108 int64_t start;
109 int64_t t;
110
111 /*
112 * Adjust the time to the closest epoch. This should be changed
113 * to use a 64-bit counterpart to isc_stdtime_get() if one ever
114 * is defined, but even the current code is good until the year
115 * 2106.
116 */
117 isc_stdtime_get(&now);
118 start = (int64_t)now;
119 if (isc_serial_gt(value, now)) {
120 t = start + (value - now);
121 } else {
122 t = start - (now - value);
123 }
124
125 return (t);
126 }
127
128 isc_result_t
dns_time32_totext(uint32_t value,isc_buffer_t * target)129 dns_time32_totext(uint32_t value, isc_buffer_t *target) {
130 return (dns_time64_totext(dns_time64_from32(value), target));
131 }
132
133 isc_result_t
dns_time64_fromtext(const char * source,int64_t * target)134 dns_time64_fromtext(const char *source, int64_t *target) {
135 int year, month, day, hour, minute, second;
136 int64_t value;
137 int secs;
138 int i;
139
140 #define RANGE(min, max, value) \
141 do { \
142 if (value < (min) || value > (max)) \
143 return ((ISC_R_RANGE)); \
144 } while (0)
145
146 if (strlen(source) != 14U) {
147 return (DNS_R_SYNTAX);
148 }
149 /*
150 * Confirm the source only consists digits. sscanf() allows some
151 * minor exceptions.
152 */
153 for (i = 0; i < 14; i++) {
154 if (!isdigit((unsigned char)source[i])) {
155 return (DNS_R_SYNTAX);
156 }
157 }
158 if (sscanf(source, "%4d%2d%2d%2d%2d%2d", &year, &month, &day, &hour,
159 &minute, &second) != 6)
160 {
161 return (DNS_R_SYNTAX);
162 }
163
164 RANGE(0, 9999, year);
165 RANGE(1, 12, month);
166 RANGE(1, days[month - 1] + ((month == 2 && is_leap(year)) ? 1 : 0),
167 day);
168 #ifdef __COVERITY__
169 /*
170 * Use a simplified range to silence Coverity warning (in
171 * arithmetic with day below).
172 */
173 RANGE(1, 31, day);
174 #endif /* __COVERITY__ */
175
176 RANGE(0, 23, hour);
177 RANGE(0, 59, minute);
178 RANGE(0, 60, second); /* 60 == leap second. */
179
180 /*
181 * Calculate seconds from epoch.
182 * Note: this uses a idealized calendar.
183 */
184 value = second + (60 * minute) + (3600 * hour) + ((day - 1) * 86400);
185 for (i = 0; i < (month - 1); i++) {
186 value += days[i] * 86400;
187 }
188 if (is_leap(year) && month > 2) {
189 value += 86400;
190 }
191 if (year < 1970) {
192 for (i = 1969; i >= year; i--) {
193 secs = (is_leap(i) ? 366 : 365) * 86400;
194 value -= secs;
195 }
196 } else {
197 for (i = 1970; i < year; i++) {
198 secs = (is_leap(i) ? 366 : 365) * 86400;
199 value += secs;
200 }
201 }
202
203 *target = value;
204 return (ISC_R_SUCCESS);
205 }
206
207 isc_result_t
dns_time32_fromtext(const char * source,uint32_t * target)208 dns_time32_fromtext(const char *source, uint32_t *target) {
209 int64_t value64;
210 isc_result_t result;
211 result = dns_time64_fromtext(source, &value64);
212 if (result != ISC_R_SUCCESS) {
213 return (result);
214 }
215 *target = (uint32_t)value64;
216
217 return (ISC_R_SUCCESS);
218 }
219