strptime.c revision 1.27
1/* $OpenBSD: strptime.c,v 1.27 2019/05/10 20:24:58 schwarze Exp $ */ 2/* $NetBSD: strptime.c,v 1.12 1998/01/20 21:39:40 mycroft Exp $ */ 3/*- 4 * Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code was contributed to The NetBSD Foundation by Klaus Klein. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <ctype.h> 32#include <locale.h> 33#include <stdint.h> 34#include <string.h> 35#include <time.h> 36 37#include "localedef.h" 38#include "private.h" 39#include "tzfile.h" 40 41#define _ctloc(x) (_CurrentTimeLocale->x) 42 43/* 44 * We do not implement alternate representations. However, we always 45 * check whether a given modifier is allowed for a certain conversion. 46 */ 47#define _ALT_E 0x01 48#define _ALT_O 0x02 49#define _LEGAL_ALT(x) { if (alt_format & ~(x)) return (0); } 50 51/* 52 * We keep track of some of the fields we set in order to compute missing ones. 53 */ 54#define FIELD_TM_MON (1 << 0) 55#define FIELD_TM_MDAY (1 << 1) 56#define FIELD_TM_WDAY (1 << 2) 57#define FIELD_TM_YDAY (1 << 3) 58#define FIELD_TM_YEAR (1 << 4) 59 60static char gmt[] = { "GMT" }; 61static char utc[] = { "UTC" }; 62/* RFC-822/RFC-2822 */ 63static const char * const nast[5] = { 64 "EST", "CST", "MST", "PST", "\0\0\0" 65}; 66static const char * const nadt[5] = { 67 "EDT", "CDT", "MDT", "PDT", "\0\0\0" 68}; 69 70static const int mon_lengths[2][MONSPERYEAR] = { 71 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 72 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 73}; 74 75static int _conv_num64(const unsigned char **, int64_t *, int64_t, int64_t); 76static int _conv_num(const unsigned char **, int *, int, int); 77static int leaps_thru_end_of(const int y); 78static char *_strptime(const char *, const char *, struct tm *, int); 79static const u_char *_find_string(const u_char *, int *, const char * const *, 80 const char * const *, int); 81 82 83char * 84strptime(const char *buf, const char *fmt, struct tm *tm) 85{ 86 return(_strptime(buf, fmt, tm, 1)); 87} 88DEF_WEAK(strptime); 89 90static char * 91_strptime(const char *buf, const char *fmt, struct tm *tm, int initialize) 92{ 93 unsigned char c; 94 const unsigned char *bp, *ep; 95 size_t len; 96 int alt_format, i, offs; 97 int neg = 0; 98 static int century, relyear, fields; 99 100 if (initialize) { 101 century = TM_YEAR_BASE; 102 relyear = -1; 103 fields = 0; 104 } 105 106 bp = (const unsigned char *)buf; 107 while ((c = *fmt) != '\0') { 108 /* Clear `alternate' modifier prior to new conversion. */ 109 alt_format = 0; 110 111 /* Eat up white-space. */ 112 if (isspace(c)) { 113 while (isspace(*bp)) 114 bp++; 115 116 fmt++; 117 continue; 118 } 119 120 if ((c = *fmt++) != '%') 121 goto literal; 122 123 124again: switch (c = *fmt++) { 125 case '%': /* "%%" is converted to "%". */ 126literal: 127 if (c != *bp++) 128 return (NULL); 129 130 break; 131 132 /* 133 * "Alternative" modifiers. Just set the appropriate flag 134 * and start over again. 135 */ 136 case 'E': /* "%E?" alternative conversion modifier. */ 137 _LEGAL_ALT(0); 138 alt_format |= _ALT_E; 139 goto again; 140 141 case 'O': /* "%O?" alternative conversion modifier. */ 142 _LEGAL_ALT(0); 143 alt_format |= _ALT_O; 144 goto again; 145 146 /* 147 * "Complex" conversion rules, implemented through recursion. 148 */ 149 case 'c': /* Date and time, using the locale's format. */ 150 _LEGAL_ALT(_ALT_E); 151 if (!(bp = _strptime(bp, _ctloc(d_t_fmt), tm, 0))) 152 return (NULL); 153 break; 154 155 case 'D': /* The date as "%m/%d/%y". */ 156 _LEGAL_ALT(0); 157 if (!(bp = _strptime(bp, "%m/%d/%y", tm, 0))) 158 return (NULL); 159 break; 160 161 case 'F': /* The date as "%Y-%m-%d". */ 162 _LEGAL_ALT(0); 163 if (!(bp = _strptime(bp, "%Y-%m-%d", tm, 0))) 164 return (NULL); 165 continue; 166 167 case 'R': /* The time as "%H:%M". */ 168 _LEGAL_ALT(0); 169 if (!(bp = _strptime(bp, "%H:%M", tm, 0))) 170 return (NULL); 171 break; 172 173 case 'r': /* The time as "%I:%M:%S %p". */ 174 _LEGAL_ALT(0); 175 if (!(bp = _strptime(bp, "%I:%M:%S %p", tm, 0))) 176 return (NULL); 177 break; 178 179 case 'T': /* The time as "%H:%M:%S". */ 180 _LEGAL_ALT(0); 181 if (!(bp = _strptime(bp, "%H:%M:%S", tm, 0))) 182 return (NULL); 183 break; 184 185 case 'X': /* The time, using the locale's format. */ 186 _LEGAL_ALT(_ALT_E); 187 if (!(bp = _strptime(bp, _ctloc(t_fmt), tm, 0))) 188 return (NULL); 189 break; 190 191 case 'x': /* The date, using the locale's format. */ 192 _LEGAL_ALT(_ALT_E); 193 if (!(bp = _strptime(bp, _ctloc(d_fmt), tm, 0))) 194 return (NULL); 195 break; 196 197 /* 198 * "Elementary" conversion rules. 199 */ 200 case 'A': /* The day of week, using the locale's form. */ 201 case 'a': 202 _LEGAL_ALT(0); 203 for (i = 0; i < 7; i++) { 204 /* Full name. */ 205 len = strlen(_ctloc(day[i])); 206 if (strncasecmp(_ctloc(day[i]), bp, len) == 0) 207 break; 208 209 /* Abbreviated name. */ 210 len = strlen(_ctloc(abday[i])); 211 if (strncasecmp(_ctloc(abday[i]), bp, len) == 0) 212 break; 213 } 214 215 /* Nothing matched. */ 216 if (i == 7) 217 return (NULL); 218 219 tm->tm_wday = i; 220 bp += len; 221 fields |= FIELD_TM_WDAY; 222 break; 223 224 case 'B': /* The month, using the locale's form. */ 225 case 'b': 226 case 'h': 227 _LEGAL_ALT(0); 228 for (i = 0; i < 12; i++) { 229 /* Full name. */ 230 len = strlen(_ctloc(mon[i])); 231 if (strncasecmp(_ctloc(mon[i]), bp, len) == 0) 232 break; 233 234 /* Abbreviated name. */ 235 len = strlen(_ctloc(abmon[i])); 236 if (strncasecmp(_ctloc(abmon[i]), bp, len) == 0) 237 break; 238 } 239 240 /* Nothing matched. */ 241 if (i == 12) 242 return (NULL); 243 244 tm->tm_mon = i; 245 bp += len; 246 fields |= FIELD_TM_MON; 247 break; 248 249 case 'C': /* The century number. */ 250 _LEGAL_ALT(_ALT_E); 251 if (!(_conv_num(&bp, &i, 0, 99))) 252 return (NULL); 253 254 century = i * 100; 255 break; 256 257 case 'e': /* The day of month. */ 258 if (isspace(*bp)) 259 bp++; 260 /* FALLTHROUGH */ 261 case 'd': 262 _LEGAL_ALT(_ALT_O); 263 if (!(_conv_num(&bp, &tm->tm_mday, 1, 31))) 264 return (NULL); 265 fields |= FIELD_TM_MDAY; 266 break; 267 268 case 'k': /* The hour (24-hour clock representation). */ 269 _LEGAL_ALT(0); 270 /* FALLTHROUGH */ 271 case 'H': 272 _LEGAL_ALT(_ALT_O); 273 if (!(_conv_num(&bp, &tm->tm_hour, 0, 23))) 274 return (NULL); 275 break; 276 277 case 'l': /* The hour (12-hour clock representation). */ 278 _LEGAL_ALT(0); 279 /* FALLTHROUGH */ 280 case 'I': 281 _LEGAL_ALT(_ALT_O); 282 if (!(_conv_num(&bp, &tm->tm_hour, 1, 12))) 283 return (NULL); 284 break; 285 286 case 'j': /* The day of year. */ 287 _LEGAL_ALT(0); 288 if (!(_conv_num(&bp, &tm->tm_yday, 1, 366))) 289 return (NULL); 290 tm->tm_yday--; 291 fields |= FIELD_TM_YDAY; 292 break; 293 294 case 'M': /* The minute. */ 295 _LEGAL_ALT(_ALT_O); 296 if (!(_conv_num(&bp, &tm->tm_min, 0, 59))) 297 return (NULL); 298 break; 299 300 case 'm': /* The month. */ 301 _LEGAL_ALT(_ALT_O); 302 if (!(_conv_num(&bp, &tm->tm_mon, 1, 12))) 303 return (NULL); 304 tm->tm_mon--; 305 fields |= FIELD_TM_MON; 306 break; 307 308 case 'p': /* The locale's equivalent of AM/PM. */ 309 _LEGAL_ALT(0); 310 /* AM? */ 311 len = strlen(_ctloc(am_pm[0])); 312 if (strncasecmp(_ctloc(am_pm[0]), bp, len) == 0) { 313 if (tm->tm_hour > 12) /* i.e., 13:00 AM ?! */ 314 return (NULL); 315 else if (tm->tm_hour == 12) 316 tm->tm_hour = 0; 317 318 bp += len; 319 break; 320 } 321 /* PM? */ 322 len = strlen(_ctloc(am_pm[1])); 323 if (strncasecmp(_ctloc(am_pm[1]), bp, len) == 0) { 324 if (tm->tm_hour > 12) /* i.e., 13:00 PM ?! */ 325 return (NULL); 326 else if (tm->tm_hour < 12) 327 tm->tm_hour += 12; 328 329 bp += len; 330 break; 331 } 332 333 /* Nothing matched. */ 334 return (NULL); 335 336 case 'S': /* The seconds. */ 337 _LEGAL_ALT(_ALT_O); 338 if (!(_conv_num(&bp, &tm->tm_sec, 0, 60))) 339 return (NULL); 340 break; 341 case 's': /* Seconds since epoch */ 342 { 343 int64_t i64; 344 if (!(_conv_num64(&bp, &i64, 0, INT64_MAX))) 345 return (NULL); 346 if (!gmtime_r(&i64, tm)) 347 return (NULL); 348 fields = 0xffff; /* everything */ 349 } 350 break; 351 case 'U': /* The week of year, beginning on sunday. */ 352 case 'W': /* The week of year, beginning on monday. */ 353 _LEGAL_ALT(_ALT_O); 354 /* 355 * XXX This is bogus, as we can not assume any valid 356 * information present in the tm structure at this 357 * point to calculate a real value, so just check the 358 * range for now. 359 */ 360 if (!(_conv_num(&bp, &i, 0, 53))) 361 return (NULL); 362 break; 363 364 case 'w': /* The day of week, beginning on sunday. */ 365 _LEGAL_ALT(_ALT_O); 366 if (!(_conv_num(&bp, &tm->tm_wday, 0, 6))) 367 return (NULL); 368 fields |= FIELD_TM_WDAY; 369 break; 370 371 case 'u': /* The day of week, monday = 1. */ 372 _LEGAL_ALT(_ALT_O); 373 if (!(_conv_num(&bp, &i, 1, 7))) 374 return (NULL); 375 tm->tm_wday = i % 7; 376 fields |= FIELD_TM_WDAY; 377 continue; 378 379 case 'g': /* The year corresponding to the ISO week 380 * number but without the century. 381 */ 382 if (!(_conv_num(&bp, &i, 0, 99))) 383 return (NULL); 384 continue; 385 386 case 'G': /* The year corresponding to the ISO week 387 * number with century. 388 */ 389 do 390 bp++; 391 while (isdigit(*bp)); 392 continue; 393 394 case 'V': /* The ISO 8601:1988 week number as decimal */ 395 if (!(_conv_num(&bp, &i, 0, 53))) 396 return (NULL); 397 continue; 398 399 case 'Y': /* The year. */ 400 _LEGAL_ALT(_ALT_E); 401 if (!(_conv_num(&bp, &i, 0, 9999))) 402 return (NULL); 403 404 relyear = -1; 405 tm->tm_year = i - TM_YEAR_BASE; 406 fields |= FIELD_TM_YEAR; 407 break; 408 409 case 'y': /* The year within the century (2 digits). */ 410 _LEGAL_ALT(_ALT_E | _ALT_O); 411 if (!(_conv_num(&bp, &relyear, 0, 99))) 412 return (NULL); 413 break; 414 415 case 'Z': 416 tzset(); 417 if (strncmp((const char *)bp, gmt, 3) == 0) { 418 tm->tm_isdst = 0; 419#ifdef TM_GMTOFF 420 tm->TM_GMTOFF = 0; 421#endif 422#ifdef TM_ZONE 423 tm->TM_ZONE = gmt; 424#endif 425 bp += 3; 426 } else if (strncmp((const char *)bp, utc, 3) == 0) { 427 tm->tm_isdst = 0; 428#ifdef TM_GMTOFF 429 tm->TM_GMTOFF = 0; 430#endif 431#ifdef TM_ZONE 432 tm->TM_ZONE = utc; 433#endif 434 bp += 3; 435 } else { 436 ep = _find_string(bp, &i, 437 (const char * const *)tzname, 438 NULL, 2); 439 if (ep == NULL) 440 return (NULL); 441 442 tm->tm_isdst = i; 443#ifdef TM_GMTOFF 444 tm->TM_GMTOFF = -(timezone); 445#endif 446#ifdef TM_ZONE 447 tm->TM_ZONE = tzname[i]; 448#endif 449 bp = ep; 450 } 451 continue; 452 453 case 'z': 454 /* 455 * We recognize all ISO 8601 formats: 456 * Z = Zulu time/UTC 457 * [+-]hhmm 458 * [+-]hh:mm 459 * [+-]hh 460 * We recognize all RFC-822/RFC-2822 formats: 461 * UT|GMT 462 * North American : UTC offsets 463 * E[DS]T = Eastern : -4 | -5 464 * C[DS]T = Central : -5 | -6 465 * M[DS]T = Mountain: -6 | -7 466 * P[DS]T = Pacific : -7 | -8 467 */ 468 while (isspace(*bp)) 469 bp++; 470 471 switch (*bp++) { 472 case 'G': 473 if (*bp++ != 'M') 474 return NULL; 475 /*FALLTHROUGH*/ 476 case 'U': 477 if (*bp++ != 'T') 478 return NULL; 479 /*FALLTHROUGH*/ 480 case 'Z': 481 tm->tm_isdst = 0; 482#ifdef TM_GMTOFF 483 tm->TM_GMTOFF = 0; 484#endif 485#ifdef TM_ZONE 486 tm->TM_ZONE = utc; 487#endif 488 continue; 489 case '+': 490 neg = 0; 491 break; 492 case '-': 493 neg = 1; 494 break; 495 default: 496 --bp; 497 ep = _find_string(bp, &i, nast, NULL, 4); 498 if (ep != NULL) { 499#ifdef TM_GMTOFF 500 tm->TM_GMTOFF = (-5 - i) * SECSPERHOUR; 501#endif 502#ifdef TM_ZONE 503 tm->TM_ZONE = (char *)nast[i]; 504#endif 505 bp = ep; 506 continue; 507 } 508 ep = _find_string(bp, &i, nadt, NULL, 4); 509 if (ep != NULL) { 510 tm->tm_isdst = 1; 511#ifdef TM_GMTOFF 512 tm->TM_GMTOFF = (-4 - i) * SECSPERHOUR; 513#endif 514#ifdef TM_ZONE 515 tm->TM_ZONE = (char *)nadt[i]; 516#endif 517 bp = ep; 518 continue; 519 } 520 return NULL; 521 } 522 offs = 0; 523 for (i = 0; i < 4; ) { 524 if (isdigit(*bp)) { 525 offs = offs * 10 + (*bp++ - '0'); 526 i++; 527 continue; 528 } 529 if (i == 2 && *bp == ':') { 530 bp++; 531 continue; 532 } 533 break; 534 } 535 switch (i) { 536 case 2: 537 offs *= 100; 538 break; 539 case 4: 540 i = offs % 100; 541 if (i >= 60) 542 return NULL; 543 /* Convert minutes into decimal */ 544 offs = (offs / 100) * 100 + (i * 50) / 30; 545 break; 546 default: 547 return NULL; 548 } 549 if (neg) 550 offs = -offs; 551 tm->tm_isdst = 0; /* XXX */ 552#ifdef TM_GMTOFF 553 tm->TM_GMTOFF = offs; 554#endif 555#ifdef TM_ZONE 556 tm->TM_ZONE = NULL; /* XXX */ 557#endif 558 continue; 559 560 /* 561 * Miscellaneous conversions. 562 */ 563 case 'n': /* Any kind of white-space. */ 564 case 't': 565 _LEGAL_ALT(0); 566 while (isspace(*bp)) 567 bp++; 568 break; 569 570 571 default: /* Unknown/unsupported conversion. */ 572 return (NULL); 573 } 574 575 576 } 577 578 /* 579 * We need to evaluate the two digit year spec (%y) 580 * last as we can get a century spec (%C) at any time. 581 */ 582 if (relyear != -1) { 583 if (century == TM_YEAR_BASE) { 584 if (relyear <= 68) 585 tm->tm_year = relyear + 2000 - TM_YEAR_BASE; 586 else 587 tm->tm_year = relyear + 1900 - TM_YEAR_BASE; 588 } else { 589 tm->tm_year = relyear + century - TM_YEAR_BASE; 590 } 591 fields |= FIELD_TM_YEAR; 592 } 593 594 /* Compute some missing values when possible. */ 595 if (fields & FIELD_TM_YEAR) { 596 const int year = tm->tm_year + TM_YEAR_BASE; 597 const int *mon_lens = mon_lengths[isleap(year)]; 598 if (!(fields & FIELD_TM_YDAY) && 599 (fields & FIELD_TM_MON) && (fields & FIELD_TM_MDAY)) { 600 tm->tm_yday = tm->tm_mday - 1; 601 for (i = 0; i < tm->tm_mon; i++) 602 tm->tm_yday += mon_lens[i]; 603 fields |= FIELD_TM_YDAY; 604 } 605 if (fields & FIELD_TM_YDAY) { 606 int days = tm->tm_yday; 607 if (!(fields & FIELD_TM_WDAY)) { 608 tm->tm_wday = EPOCH_WDAY + 609 ((year - EPOCH_YEAR) % DAYSPERWEEK) * 610 (DAYSPERNYEAR % DAYSPERWEEK) + 611 leaps_thru_end_of(year - 1) - 612 leaps_thru_end_of(EPOCH_YEAR - 1) + 613 tm->tm_yday; 614 tm->tm_wday %= DAYSPERWEEK; 615 if (tm->tm_wday < 0) 616 tm->tm_wday += DAYSPERWEEK; 617 } 618 if (!(fields & FIELD_TM_MON)) { 619 tm->tm_mon = 0; 620 while (tm->tm_mon < MONSPERYEAR && days >= mon_lens[tm->tm_mon]) 621 days -= mon_lens[tm->tm_mon++]; 622 } 623 if (!(fields & FIELD_TM_MDAY)) 624 tm->tm_mday = days + 1; 625 } 626 } 627 628 return ((char *)bp); 629} 630 631 632static int 633_conv_num(const unsigned char **buf, int *dest, int llim, int ulim) 634{ 635 int result = 0; 636 int rulim = ulim; 637 638 if (**buf < '0' || **buf > '9') 639 return (0); 640 641 /* we use rulim to break out of the loop when we run out of digits */ 642 do { 643 result *= 10; 644 result += *(*buf)++ - '0'; 645 rulim /= 10; 646 } while ((result * 10 <= ulim) && rulim && **buf >= '0' && **buf <= '9'); 647 648 if (result < llim || result > ulim) 649 return (0); 650 651 *dest = result; 652 return (1); 653} 654 655static int 656_conv_num64(const unsigned char **buf, int64_t *dest, int64_t llim, int64_t ulim) 657{ 658 int result = 0; 659 int64_t rulim = ulim; 660 661 if (**buf < '0' || **buf > '9') 662 return (0); 663 664 /* we use rulim to break out of the loop when we run out of digits */ 665 do { 666 result *= 10; 667 result += *(*buf)++ - '0'; 668 rulim /= 10; 669 } while ((result * 10 <= ulim) && rulim && **buf >= '0' && **buf <= '9'); 670 671 if (result < llim || result > ulim) 672 return (0); 673 674 *dest = result; 675 return (1); 676} 677 678static const u_char * 679_find_string(const u_char *bp, int *tgt, const char * const *n1, 680 const char * const *n2, int c) 681{ 682 int i; 683 unsigned int len; 684 685 /* check full name - then abbreviated ones */ 686 for (; n1 != NULL; n1 = n2, n2 = NULL) { 687 for (i = 0; i < c; i++, n1++) { 688 len = strlen(*n1); 689 if (strncasecmp(*n1, (const char *)bp, len) == 0) { 690 *tgt = i; 691 return bp + len; 692 } 693 } 694 } 695 696 /* Nothing matched */ 697 return NULL; 698} 699 700static int 701leaps_thru_end_of(const int y) 702{ 703 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 704 -(leaps_thru_end_of(-(y + 1)) + 1); 705} 706