1 /* $NetBSD: tm.c,v 1.1 2024/02/18 20:57:50 christos Exp $ */ 2 3 /* 4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC") 5 * 6 * SPDX-License-Identifier: MPL-2.0 AND BSD-2-Clause 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 /*- 17 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc. 18 * All rights reserved. 19 * 20 * This code was contributed to The NetBSD Foundation by Klaus Klein. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 31 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 32 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 33 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 34 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 35 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 36 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 37 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 38 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 39 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41 * POSSIBILITY OF SUCH DAMAGE. 42 */ 43 44 #include <ctype.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <time.h> 49 50 #include <isc/tm.h> 51 #include <isc/util.h> 52 53 /* 54 * Portable conversion routines for struct tm, replacing 55 * timegm() and strptime(), which are not available on all 56 * platforms and don't always behave the same way when they 57 * are. 58 */ 59 60 /* 61 * We do not implement alternate representations. However, we always 62 * check whether a given modifier is allowed for a certain conversion. 63 */ 64 #define ALT_E 0x01 65 #define ALT_O 0x02 66 #define LEGAL_ALT(x) \ 67 { \ 68 if ((alt_format & ~(x)) != 0) \ 69 return ((0)); \ 70 } 71 72 #ifndef TM_YEAR_BASE 73 #define TM_YEAR_BASE 1900 74 #endif /* ifndef TM_YEAR_BASE */ 75 76 static const char *day[7] = { "Sunday", "Monday", "Tuesday", "Wednesday", 77 "Thursday", "Friday", "Saturday" }; 78 static const char *abday[7] = { 79 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" 80 }; 81 static const char *mon[12] = { 82 "January", "February", "March", "April", "May", "June", 83 "July", "August", "September", "October", "November", "December" 84 }; 85 static const char *abmon[12] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", 86 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; 87 static const char *am_pm[2] = { "AM", "PM" }; 88 89 static int 90 conv_num(const char **buf, int *dest, int llim, int ulim) { 91 int result = 0; 92 93 /* The limit also determines the number of valid digits. */ 94 int rulim = ulim; 95 96 if (!isdigit((unsigned char)**buf)) { 97 return (0); 98 } 99 100 do { 101 result *= 10; 102 result += *(*buf)++ - '0'; 103 rulim /= 10; 104 } while ((result * 10 <= ulim) && rulim && **buf >= '0' && 105 **buf <= '9'); 106 107 if (result < llim || result > ulim) { 108 return (0); 109 } 110 111 *dest = result; 112 return (1); 113 } 114 115 time_t 116 isc_tm_timegm(struct tm *tm) { 117 time_t ret; 118 int i, yday = 0, leapday; 119 int mdays[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30 }; 120 121 leapday = ((((tm->tm_year + 1900) % 4) == 0 && 122 ((tm->tm_year + 1900) % 100) != 0) || 123 ((tm->tm_year + 1900) % 400) == 0) 124 ? 1 125 : 0; 126 mdays[1] += leapday; 127 128 yday = tm->tm_mday - 1; 129 for (i = 1; i <= tm->tm_mon; i++) { 130 yday += mdays[i - 1]; 131 } 132 ret = tm->tm_sec + (60 * tm->tm_min) + (3600 * tm->tm_hour) + 133 (86400 * 134 (yday + ((tm->tm_year - 70) * 365) + ((tm->tm_year - 69) / 4) - 135 ((tm->tm_year - 1) / 100) + ((tm->tm_year + 299) / 400))); 136 return (ret); 137 } 138 139 char * 140 isc_tm_strptime(const char *buf, const char *fmt, struct tm *tm) { 141 char c, *ret; 142 const char *bp; 143 size_t len = 0; 144 int alt_format, i, split_year = 0; 145 146 REQUIRE(buf != NULL); 147 REQUIRE(fmt != NULL); 148 REQUIRE(tm != NULL); 149 150 memset(tm, 0, sizeof(struct tm)); 151 152 bp = buf; 153 154 while ((c = *fmt) != '\0') { 155 /* Clear `alternate' modifier prior to new conversion. */ 156 alt_format = 0; 157 158 /* Eat up white-space. */ 159 if (isspace((unsigned char)c)) { 160 while (isspace((unsigned char)*bp)) { 161 bp++; 162 } 163 164 fmt++; 165 continue; 166 } 167 168 if ((c = *fmt++) != '%') { 169 goto literal; 170 } 171 172 again: 173 switch (c = *fmt++) { 174 case '%': /* "%%" is converted to "%". */ 175 literal: 176 if (c != *bp++) { 177 return (0); 178 } 179 break; 180 181 /* 182 * "Alternative" modifiers. Just set the appropriate flag 183 * and start over again. 184 */ 185 case 'E': /* "%E?" alternative conversion modifier. */ 186 LEGAL_ALT(0); 187 alt_format |= ALT_E; 188 goto again; 189 190 case 'O': /* "%O?" alternative conversion modifier. */ 191 LEGAL_ALT(0); 192 alt_format |= ALT_O; 193 goto again; 194 195 /* 196 * "Complex" conversion rules, implemented through recursion. 197 */ 198 case 'c': /* Date and time, using the locale's format. */ 199 LEGAL_ALT(ALT_E); 200 if (!(bp = isc_tm_strptime(bp, "%x %X", tm))) { 201 return (0); 202 } 203 break; 204 205 case 'D': /* The date as "%m/%d/%y". */ 206 LEGAL_ALT(0); 207 if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm))) { 208 return (0); 209 } 210 break; 211 212 case 'R': /* The time as "%H:%M". */ 213 LEGAL_ALT(0); 214 if (!(bp = isc_tm_strptime(bp, "%H:%M", tm))) { 215 return (0); 216 } 217 break; 218 219 case 'r': /* The time in 12-hour clock representation. */ 220 LEGAL_ALT(0); 221 if (!(bp = isc_tm_strptime(bp, "%I:%M:%S %p", tm))) { 222 return (0); 223 } 224 break; 225 226 case 'T': /* The time as "%H:%M:%S". */ 227 LEGAL_ALT(0); 228 if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm))) { 229 return (0); 230 } 231 break; 232 233 case 'X': /* The time, using the locale's format. */ 234 LEGAL_ALT(ALT_E); 235 if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm))) { 236 return (0); 237 } 238 break; 239 240 case 'x': /* The date, using the locale's format. */ 241 LEGAL_ALT(ALT_E); 242 if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm))) { 243 return (0); 244 } 245 break; 246 247 /* 248 * "Elementary" conversion rules. 249 */ 250 case 'A': /* The day of week, using the locale's form. */ 251 case 'a': 252 LEGAL_ALT(0); 253 for (i = 0; i < 7; i++) { 254 /* Full name. */ 255 len = strlen(day[i]); 256 if (strncasecmp(day[i], bp, len) == 0) { 257 break; 258 } 259 260 /* Abbreviated name. */ 261 len = strlen(abday[i]); 262 if (strncasecmp(abday[i], bp, len) == 0) { 263 break; 264 } 265 } 266 267 /* Nothing matched. */ 268 if (i == 7) { 269 return (0); 270 } 271 272 tm->tm_wday = i; 273 bp += len; 274 break; 275 276 case 'B': /* The month, using the locale's form. */ 277 case 'b': 278 case 'h': 279 LEGAL_ALT(0); 280 for (i = 0; i < 12; i++) { 281 /* Full name. */ 282 len = strlen(mon[i]); 283 if (strncasecmp(mon[i], bp, len) == 0) { 284 break; 285 } 286 287 /* Abbreviated name. */ 288 len = strlen(abmon[i]); 289 if (strncasecmp(abmon[i], bp, len) == 0) { 290 break; 291 } 292 } 293 294 /* Nothing matched. */ 295 if (i == 12) { 296 return (0); 297 } 298 299 tm->tm_mon = i; 300 bp += len; 301 break; 302 303 case 'C': /* The century number. */ 304 LEGAL_ALT(ALT_E); 305 if (!(conv_num(&bp, &i, 0, 99))) { 306 return (0); 307 } 308 309 if (split_year) { 310 tm->tm_year = (tm->tm_year % 100) + (i * 100); 311 } else { 312 tm->tm_year = i * 100; 313 split_year = 1; 314 } 315 break; 316 317 case 'd': /* The day of month. */ 318 case 'e': 319 LEGAL_ALT(ALT_O); 320 if (!(conv_num(&bp, &tm->tm_mday, 1, 31))) { 321 return (0); 322 } 323 break; 324 325 case 'k': /* The hour (24-hour clock representation). */ 326 LEGAL_ALT(0); 327 FALLTHROUGH; 328 case 'H': 329 LEGAL_ALT(ALT_O); 330 if (!(conv_num(&bp, &tm->tm_hour, 0, 23))) { 331 return (0); 332 } 333 break; 334 335 case 'l': /* The hour (12-hour clock representation). */ 336 LEGAL_ALT(0); 337 FALLTHROUGH; 338 case 'I': 339 LEGAL_ALT(ALT_O); 340 if (!(conv_num(&bp, &tm->tm_hour, 1, 12))) { 341 return (0); 342 } 343 if (tm->tm_hour == 12) { 344 tm->tm_hour = 0; 345 } 346 break; 347 348 case 'j': /* The day of year. */ 349 LEGAL_ALT(0); 350 if (!(conv_num(&bp, &i, 1, 366))) { 351 return (0); 352 } 353 tm->tm_yday = i - 1; 354 break; 355 356 case 'M': /* The minute. */ 357 LEGAL_ALT(ALT_O); 358 if (!(conv_num(&bp, &tm->tm_min, 0, 59))) { 359 return (0); 360 } 361 break; 362 363 case 'm': /* The month. */ 364 LEGAL_ALT(ALT_O); 365 if (!(conv_num(&bp, &i, 1, 12))) { 366 return (0); 367 } 368 tm->tm_mon = i - 1; 369 break; 370 371 case 'p': /* The locale's equivalent of AM/PM. */ 372 LEGAL_ALT(0); 373 /* AM? */ 374 if (strcasecmp(am_pm[0], bp) == 0) { 375 if (tm->tm_hour > 11) { 376 return (0); 377 } 378 379 bp += strlen(am_pm[0]); 380 break; 381 } 382 /* PM? */ 383 else if (strcasecmp(am_pm[1], bp) == 0) 384 { 385 if (tm->tm_hour > 11) { 386 return (0); 387 } 388 389 tm->tm_hour += 12; 390 bp += strlen(am_pm[1]); 391 break; 392 } 393 394 /* Nothing matched. */ 395 return (0); 396 397 case 'S': /* The seconds. */ 398 LEGAL_ALT(ALT_O); 399 if (!(conv_num(&bp, &tm->tm_sec, 0, 61))) { 400 return (0); 401 } 402 break; 403 404 case 'U': /* The week of year, beginning on sunday. */ 405 case 'W': /* The week of year, beginning on monday. */ 406 LEGAL_ALT(ALT_O); 407 /* 408 * XXX This is bogus, as we can not assume any valid 409 * information present in the tm structure at this 410 * point to calculate a real value, so just check the 411 * range for now. 412 */ 413 if (!(conv_num(&bp, &i, 0, 53))) { 414 return (0); 415 } 416 break; 417 418 case 'w': /* The day of week, beginning on sunday. */ 419 LEGAL_ALT(ALT_O); 420 if (!(conv_num(&bp, &tm->tm_wday, 0, 6))) { 421 return (0); 422 } 423 break; 424 425 case 'Y': /* The year. */ 426 LEGAL_ALT(ALT_E); 427 if (!(conv_num(&bp, &i, 0, 9999))) { 428 return (0); 429 } 430 431 tm->tm_year = i - TM_YEAR_BASE; 432 break; 433 434 case 'y': /* The year within 100 years of the epoch. */ 435 LEGAL_ALT(ALT_E | ALT_O); 436 if (!(conv_num(&bp, &i, 0, 99))) { 437 return (0); 438 } 439 440 if (split_year) { 441 tm->tm_year = ((tm->tm_year / 100) * 100) + i; 442 break; 443 } 444 split_year = 1; 445 if (i <= 68) { 446 tm->tm_year = i + 2000 - TM_YEAR_BASE; 447 } else { 448 tm->tm_year = i + 1900 - TM_YEAR_BASE; 449 } 450 break; 451 452 /* 453 * Miscellaneous conversions. 454 */ 455 case 'n': /* Any kind of white-space. */ 456 case 't': 457 LEGAL_ALT(0); 458 while (isspace((unsigned char)*bp)) { 459 bp++; 460 } 461 break; 462 463 default: /* Unknown/unsupported conversion. */ 464 return (0); 465 } 466 } 467 468 /* LINTED functional specification */ 469 DE_CONST(bp, ret); 470 return (ret); 471 } 472
Indexes created Sat Feb 28 05:31:39 UTC 2026