1 /* $NetBSD: tm.c,v 1.1.1.3 2014/12/10 03:34:44 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2014 Internet Systems Consortium, Inc. ("ISC") 5 * 6 * Permission to use, copy, modify, and/or distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 11 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 12 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 13 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 14 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 15 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 16 * PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 /*- 20 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc. 21 * All rights reserved. 22 * 23 * This code was contributed to The NetBSD Foundation by Klaus Klein. 24 * 25 * Redistribution and use in source and binary forms, with or without 26 * modification, are permitted provided that the following conditions 27 * are met: 28 * 1. Redistributions of source code must retain the above copyright 29 * notice, this list of conditions and the following disclaimer. 30 * 2. Redistributions in binary form must reproduce the above copyright 31 * notice, this list of conditions and the following disclaimer in the 32 * documentation and/or other materials provided with the distribution. 33 * 34 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 35 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 36 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 37 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 38 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 39 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 40 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 41 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 42 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 43 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 44 * POSSIBILITY OF SUCH DAMAGE. 45 */ 46 47 #include <config.h> 48 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <time.h> 53 #include <ctype.h> 54 55 #include <isc/tm.h> 56 #include <isc/util.h> 57 58 /* 59 * Portable conversion routines for struct tm, replacing 60 * timegm() and strptime(), which are not available on all 61 * platforms and don't always behave the same way when they 62 * are. 63 */ 64 65 /* 66 * We do not implement alternate representations. However, we always 67 * check whether a given modifier is allowed for a certain conversion. 68 */ 69 #define ALT_E 0x01 70 #define ALT_O 0x02 71 #define LEGAL_ALT(x) { if (alt_format & ~(x)) return (0); } 72 73 #ifndef TM_YEAR_BASE 74 #define TM_YEAR_BASE 1900 75 #endif 76 77 static const char *day[7] = { 78 "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", 79 "Friday", "Saturday" 80 }; 81 static const char *abday[7] = { 82 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" 83 }; 84 static const char *mon[12] = { 85 "January", "February", "March", "April", "May", "June", "July", 86 "August", "September", "October", "November", "December" 87 }; 88 static const char *abmon[12] = { 89 "Jan", "Feb", "Mar", "Apr", "May", "Jun", 90 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" 91 }; 92 static const char *am_pm[2] = { 93 "AM", "PM" 94 }; 95 96 static int 97 conv_num(const char **buf, int *dest, int llim, int ulim) { 98 int result = 0; 99 100 /* The limit also determines the number of valid digits. */ 101 int rulim = ulim; 102 103 if (**buf < '0' || **buf > '9') 104 return (0); 105 106 do { 107 result *= 10; 108 result += *(*buf)++ - '0'; 109 rulim /= 10; 110 } while ((result * 10 <= ulim) && 111 rulim && **buf >= '0' && **buf <= '9'); 112 113 if (result < llim || result > ulim) 114 return (0); 115 116 *dest = result; 117 return (1); 118 } 119 120 time_t 121 isc_tm_timegm(struct tm *tm) { 122 time_t ret; 123 int i, yday = 0, leapday; 124 int mdays[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30 }; 125 126 leapday = ((((tm->tm_year + 1900 ) % 4) == 0 && 127 ((tm->tm_year + 1900 ) % 100) != 0) || 128 ((tm->tm_year + 1900 ) % 400) == 0) ? 1 : 0; 129 mdays[1] += leapday; 130 131 yday = tm->tm_mday - 1; 132 for (i = 1; i <= tm->tm_mon; i++) 133 yday += mdays[i - 1]; 134 ret = tm->tm_sec + 135 (60 * tm->tm_min) + 136 (3600 * tm->tm_hour) + 137 (86400 * (yday + 138 ((tm->tm_year - 70) * 365) + 139 ((tm->tm_year - 69) / 4) - 140 ((tm->tm_year - 1) / 100) + 141 ((tm->tm_year + 299) / 400))); 142 return (ret); 143 } 144 145 char * 146 isc_tm_strptime(const char *buf, const char *fmt, struct tm *tm) { 147 char c, *ret; 148 const char *bp; 149 size_t len = 0; 150 int alt_format, i, split_year = 0; 151 152 REQUIRE(buf != NULL); 153 REQUIRE(fmt != NULL); 154 REQUIRE(tm != NULL); 155 156 memset(tm, 0, sizeof(struct tm)); 157 158 bp = buf; 159 160 while ((c = *fmt) != '\0') { 161 /* Clear `alternate' modifier prior to new conversion. */ 162 alt_format = 0; 163 164 /* Eat up white-space. */ 165 if (isspace((unsigned char) c)) { 166 while (isspace((unsigned char) *bp)) 167 bp++; 168 169 fmt++; 170 continue; 171 } 172 173 if ((c = *fmt++) != '%') 174 goto literal; 175 176 177 again: switch (c = *fmt++) { 178 case '%': /* "%%" is converted to "%". */ 179 literal: 180 if (c != *bp++) 181 return (0); 182 break; 183 184 /* 185 * "Alternative" modifiers. Just set the appropriate flag 186 * and start over again. 187 */ 188 case 'E': /* "%E?" alternative conversion modifier. */ 189 LEGAL_ALT(0); 190 alt_format |= ALT_E; 191 goto again; 192 193 case 'O': /* "%O?" alternative conversion modifier. */ 194 LEGAL_ALT(0); 195 alt_format |= ALT_O; 196 goto again; 197 198 /* 199 * "Complex" conversion rules, implemented through recursion. 200 */ 201 case 'c': /* Date and time, using the locale's format. */ 202 LEGAL_ALT(ALT_E); 203 if (!(bp = isc_tm_strptime(bp, "%x %X", tm))) 204 return (0); 205 break; 206 207 case 'D': /* The date as "%m/%d/%y". */ 208 LEGAL_ALT(0); 209 if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm))) 210 return (0); 211 break; 212 213 case 'R': /* The time as "%H:%M". */ 214 LEGAL_ALT(0); 215 if (!(bp = isc_tm_strptime(bp, "%H:%M", tm))) 216 return (0); 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 break; 224 225 case 'T': /* The time as "%H:%M:%S". */ 226 LEGAL_ALT(0); 227 if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm))) 228 return (0); 229 break; 230 231 case 'X': /* The time, using the locale's format. */ 232 LEGAL_ALT(ALT_E); 233 if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm))) 234 return (0); 235 break; 236 237 case 'x': /* The date, using the locale's format. */ 238 LEGAL_ALT(ALT_E); 239 if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm))) 240 return (0); 241 break; 242 243 /* 244 * "Elementary" conversion rules. 245 */ 246 case 'A': /* The day of week, using the locale's form. */ 247 case 'a': 248 LEGAL_ALT(0); 249 for (i = 0; i < 7; i++) { 250 /* Full name. */ 251 len = strlen(day[i]); 252 if (strncasecmp(day[i], bp, len) == 0) 253 break; 254 255 /* Abbreviated name. */ 256 len = strlen(abday[i]); 257 if (strncasecmp(abday[i], bp, len) == 0) 258 break; 259 } 260 261 /* Nothing matched. */ 262 if (i == 7) 263 return (0); 264 265 tm->tm_wday = i; 266 bp += len; 267 break; 268 269 case 'B': /* The month, using the locale's form. */ 270 case 'b': 271 case 'h': 272 LEGAL_ALT(0); 273 for (i = 0; i < 12; i++) { 274 /* Full name. */ 275 len = strlen(mon[i]); 276 if (strncasecmp(mon[i], bp, len) == 0) 277 break; 278 279 /* Abbreviated name. */ 280 len = strlen(abmon[i]); 281 if (strncasecmp(abmon[i], bp, len) == 0) 282 break; 283 } 284 285 /* Nothing matched. */ 286 if (i == 12) 287 return (0); 288 289 tm->tm_mon = i; 290 bp += len; 291 break; 292 293 case 'C': /* The century number. */ 294 LEGAL_ALT(ALT_E); 295 if (!(conv_num(&bp, &i, 0, 99))) 296 return (0); 297 298 if (split_year) { 299 tm->tm_year = (tm->tm_year % 100) + (i * 100); 300 } else { 301 tm->tm_year = i * 100; 302 split_year = 1; 303 } 304 break; 305 306 case 'd': /* The day of month. */ 307 case 'e': 308 LEGAL_ALT(ALT_O); 309 if (!(conv_num(&bp, &tm->tm_mday, 1, 31))) 310 return (0); 311 break; 312 313 case 'k': /* The hour (24-hour clock representation). */ 314 LEGAL_ALT(0); 315 /* FALLTHROUGH */ 316 case 'H': 317 LEGAL_ALT(ALT_O); 318 if (!(conv_num(&bp, &tm->tm_hour, 0, 23))) 319 return (0); 320 break; 321 322 case 'l': /* The hour (12-hour clock representation). */ 323 LEGAL_ALT(0); 324 /* FALLTHROUGH */ 325 case 'I': 326 LEGAL_ALT(ALT_O); 327 if (!(conv_num(&bp, &tm->tm_hour, 1, 12))) 328 return (0); 329 if (tm->tm_hour == 12) 330 tm->tm_hour = 0; 331 break; 332 333 case 'j': /* The day of year. */ 334 LEGAL_ALT(0); 335 if (!(conv_num(&bp, &i, 1, 366))) 336 return (0); 337 tm->tm_yday = i - 1; 338 break; 339 340 case 'M': /* The minute. */ 341 LEGAL_ALT(ALT_O); 342 if (!(conv_num(&bp, &tm->tm_min, 0, 59))) 343 return (0); 344 break; 345 346 case 'm': /* The month. */ 347 LEGAL_ALT(ALT_O); 348 if (!(conv_num(&bp, &i, 1, 12))) 349 return (0); 350 tm->tm_mon = i - 1; 351 break; 352 353 case 'p': /* The locale's equivalent of AM/PM. */ 354 LEGAL_ALT(0); 355 /* AM? */ 356 if (strcasecmp(am_pm[0], bp) == 0) { 357 if (tm->tm_hour > 11) 358 return (0); 359 360 bp += strlen(am_pm[0]); 361 break; 362 } 363 /* PM? */ 364 else if (strcasecmp(am_pm[1], bp) == 0) { 365 if (tm->tm_hour > 11) 366 return (0); 367 368 tm->tm_hour += 12; 369 bp += strlen(am_pm[1]); 370 break; 371 } 372 373 /* Nothing matched. */ 374 return (0); 375 376 case 'S': /* The seconds. */ 377 LEGAL_ALT(ALT_O); 378 if (!(conv_num(&bp, &tm->tm_sec, 0, 61))) 379 return (0); 380 break; 381 382 case 'U': /* The week of year, beginning on sunday. */ 383 case 'W': /* The week of year, beginning on monday. */ 384 LEGAL_ALT(ALT_O); 385 /* 386 * XXX This is bogus, as we can not assume any valid 387 * information present in the tm structure at this 388 * point to calculate a real value, so just check the 389 * range for now. 390 */ 391 if (!(conv_num(&bp, &i, 0, 53))) 392 return (0); 393 break; 394 395 case 'w': /* The day of week, beginning on sunday. */ 396 LEGAL_ALT(ALT_O); 397 if (!(conv_num(&bp, &tm->tm_wday, 0, 6))) 398 return (0); 399 break; 400 401 case 'Y': /* The year. */ 402 LEGAL_ALT(ALT_E); 403 if (!(conv_num(&bp, &i, 0, 9999))) 404 return (0); 405 406 tm->tm_year = i - TM_YEAR_BASE; 407 break; 408 409 case 'y': /* The year within 100 years of the epoch. */ 410 LEGAL_ALT(ALT_E | ALT_O); 411 if (!(conv_num(&bp, &i, 0, 99))) 412 return (0); 413 414 if (split_year) { 415 tm->tm_year = ((tm->tm_year / 100) * 100) + i; 416 break; 417 } 418 split_year = 1; 419 if (i <= 68) 420 tm->tm_year = i + 2000 - TM_YEAR_BASE; 421 else 422 tm->tm_year = i + 1900 - TM_YEAR_BASE; 423 break; 424 425 /* 426 * Miscellaneous conversions. 427 */ 428 case 'n': /* Any kind of white-space. */ 429 case 't': 430 LEGAL_ALT(0); 431 while (isspace((unsigned char) *bp)) 432 bp++; 433 break; 434 435 436 default: /* Unknown/unsupported conversion. */ 437 return (0); 438 } 439 440 441 } 442 443 /* LINTED functional specification */ 444 DE_CONST(bp, ret); 445 return (ret); 446 } 447