1 /* $OpenBSD: strptime.c,v 1.30 2019/05/12 12:49:52 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 60 static char gmt[] = { "GMT" }; 61 static char utc[] = { "UTC" }; 62 /* RFC-822/RFC-2822 */ 63 static const char * const nast[5] = { 64 "EST", "CST", "MST", "PST", "\0\0\0" 65 }; 66 static const char * const nadt[5] = { 67 "EDT", "CDT", "MDT", "PDT", "\0\0\0" 68 }; 69 70 static 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 75 static int _conv_num64(const unsigned char **, int64_t *, int64_t, int64_t); 76 static int _conv_num(const unsigned char **, int *, int, int); 77 static int leaps_thru_end_of(const int y); 78 static char *_strptime(const char *, const char *, struct tm *, int); 79 static const u_char *_find_string(const u_char *, int *, const char * const *, 80 const char * const *, int); 81 82 83 char * 84 strptime(const char *buf, const char *fmt, struct tm *tm) 85 { 86 return(_strptime(buf, fmt, tm, 1)); 87 } 88 DEF_WEAK(strptime); 89 90 static 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; 122 123 124 again: switch (c = *fmt++) { 125 case '%': /* "%%" is converted to "%". */ 126 literal: 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 tm->tm_gmtoff = 0; 420 tm->tm_zone = gmt; 421 bp += 3; 422 } else if (strncmp((const char *)bp, utc, 3) == 0) { 423 tm->tm_isdst = 0; 424 tm->tm_gmtoff = 0; 425 tm->tm_zone = utc; 426 bp += 3; 427 } else { 428 ep = _find_string(bp, &i, 429 (const char * const *)tzname, 430 NULL, 2); 431 if (ep == NULL) 432 return (NULL); 433 434 tm->tm_isdst = i; 435 tm->tm_gmtoff = -(timezone); 436 tm->tm_zone = tzname[i]; 437 bp = ep; 438 } 439 continue; 440 441 case 'z': 442 /* 443 * We recognize all ISO 8601 formats: 444 * Z = Zulu time/UTC 445 * [+-]hhmm 446 * [+-]hh:mm 447 * [+-]hh 448 * We recognize all RFC-822/RFC-2822 formats: 449 * UT|GMT 450 * North American : UTC offsets 451 * E[DS]T = Eastern : -4 | -5 452 * C[DS]T = Central : -5 | -6 453 * M[DS]T = Mountain: -6 | -7 454 * P[DS]T = Pacific : -7 | -8 455 */ 456 while (isspace(*bp)) 457 bp++; 458 459 switch (*bp++) { 460 case 'G': 461 if (*bp++ != 'M') 462 return NULL; 463 /*FALLTHROUGH*/ 464 case 'U': 465 if (*bp++ != 'T') 466 return NULL; 467 /*FALLTHROUGH*/ 468 case 'Z': 469 tm->tm_isdst = 0; 470 tm->tm_gmtoff = 0; 471 tm->tm_zone = utc; 472 continue; 473 case '+': 474 neg = 0; 475 break; 476 case '-': 477 neg = 1; 478 break; 479 default: 480 --bp; 481 ep = _find_string(bp, &i, nast, NULL, 4); 482 if (ep != NULL) { 483 tm->tm_gmtoff = (-5 - i) * SECSPERHOUR; 484 tm->tm_zone = (char *)nast[i]; 485 bp = ep; 486 continue; 487 } 488 ep = _find_string(bp, &i, nadt, NULL, 4); 489 if (ep != NULL) { 490 tm->tm_isdst = 1; 491 tm->tm_gmtoff = (-4 - i) * SECSPERHOUR; 492 tm->tm_zone = (char *)nadt[i]; 493 bp = ep; 494 continue; 495 } 496 return NULL; 497 } 498 if (!isdigit(bp[0]) || !isdigit(bp[1])) 499 return NULL; 500 offs = ((bp[0]-'0') * 10 + (bp[1]-'0')) * SECSPERHOUR; 501 bp += 2; 502 if (*bp == ':') 503 bp++; 504 if (isdigit(*bp)) { 505 offs += (*bp++ - '0') * 10 * SECSPERMIN; 506 if (!isdigit(*bp)) 507 return NULL; 508 offs += (*bp++ - '0') * SECSPERMIN; 509 } 510 if (neg) 511 offs = -offs; 512 tm->tm_isdst = 0; /* XXX */ 513 tm->tm_gmtoff = offs; 514 tm->tm_zone = NULL; /* XXX */ 515 continue; 516 517 /* 518 * Miscellaneous conversions. 519 */ 520 case 'n': /* Any kind of white-space. */ 521 case 't': 522 _LEGAL_ALT(0); 523 while (isspace(*bp)) 524 bp++; 525 break; 526 527 528 default: /* Unknown/unsupported conversion. */ 529 return (NULL); 530 } 531 532 533 } 534 535 /* 536 * We need to evaluate the two digit year spec (%y) 537 * last as we can get a century spec (%C) at any time. 538 */ 539 if (relyear != -1) { 540 if (century == TM_YEAR_BASE) { 541 if (relyear <= 68) 542 tm->tm_year = relyear + 2000 - TM_YEAR_BASE; 543 else 544 tm->tm_year = relyear + 1900 - TM_YEAR_BASE; 545 } else { 546 tm->tm_year = relyear + century - TM_YEAR_BASE; 547 } 548 fields |= FIELD_TM_YEAR; 549 } 550 551 /* Compute some missing values when possible. */ 552 if (fields & FIELD_TM_YEAR) { 553 const int year = tm->tm_year + TM_YEAR_BASE; 554 const int *mon_lens = mon_lengths[isleap(year)]; 555 if (!(fields & FIELD_TM_YDAY) && 556 (fields & FIELD_TM_MON) && (fields & FIELD_TM_MDAY)) { 557 tm->tm_yday = tm->tm_mday - 1; 558 for (i = 0; i < tm->tm_mon; i++) 559 tm->tm_yday += mon_lens[i]; 560 fields |= FIELD_TM_YDAY; 561 } 562 if (fields & FIELD_TM_YDAY) { 563 int days = tm->tm_yday; 564 if (!(fields & FIELD_TM_WDAY)) { 565 tm->tm_wday = EPOCH_WDAY + 566 ((year - EPOCH_YEAR) % DAYSPERWEEK) * 567 (DAYSPERNYEAR % DAYSPERWEEK) + 568 leaps_thru_end_of(year - 1) - 569 leaps_thru_end_of(EPOCH_YEAR - 1) + 570 tm->tm_yday; 571 tm->tm_wday %= DAYSPERWEEK; 572 if (tm->tm_wday < 0) 573 tm->tm_wday += DAYSPERWEEK; 574 } 575 if (!(fields & FIELD_TM_MON)) { 576 tm->tm_mon = 0; 577 while (tm->tm_mon < MONSPERYEAR && days >= mon_lens[tm->tm_mon]) 578 days -= mon_lens[tm->tm_mon++]; 579 } 580 if (!(fields & FIELD_TM_MDAY)) 581 tm->tm_mday = days + 1; 582 } 583 } 584 585 return ((char *)bp); 586 } 587 588 589 static int 590 _conv_num(const unsigned char **buf, int *dest, int llim, int ulim) 591 { 592 int result = 0; 593 int rulim = ulim; 594 595 if (**buf < '0' || **buf > '9') 596 return (0); 597 598 /* we use rulim to break out of the loop when we run out of digits */ 599 do { 600 result *= 10; 601 result += *(*buf)++ - '0'; 602 rulim /= 10; 603 } while ((result * 10 <= ulim) && rulim && **buf >= '0' && **buf <= '9'); 604 605 if (result < llim || result > ulim) 606 return (0); 607 608 *dest = result; 609 return (1); 610 } 611 612 static int 613 _conv_num64(const unsigned char **buf, int64_t *dest, int64_t llim, int64_t ulim) 614 { 615 int result = 0; 616 int64_t rulim = ulim; 617 618 if (**buf < '0' || **buf > '9') 619 return (0); 620 621 /* we use rulim to break out of the loop when we run out of digits */ 622 do { 623 result *= 10; 624 result += *(*buf)++ - '0'; 625 rulim /= 10; 626 } while ((result * 10 <= ulim) && rulim && **buf >= '0' && **buf <= '9'); 627 628 if (result < llim || result > ulim) 629 return (0); 630 631 *dest = result; 632 return (1); 633 } 634 635 static const u_char * 636 _find_string(const u_char *bp, int *tgt, const char * const *n1, 637 const char * const *n2, int c) 638 { 639 int i; 640 unsigned int len; 641 642 /* check full name - then abbreviated ones */ 643 for (; n1 != NULL; n1 = n2, n2 = NULL) { 644 for (i = 0; i < c; i++, n1++) { 645 len = strlen(*n1); 646 if (strncasecmp(*n1, (const char *)bp, len) == 0) { 647 *tgt = i; 648 return bp + len; 649 } 650 } 651 } 652 653 /* Nothing matched */ 654 return NULL; 655 } 656 657 static int 658 leaps_thru_end_of(const int y) 659 { 660 return (y >= 0) ? (y / 4 - y / 100 + y / 400) : 661 -(leaps_thru_end_of(-(y + 1)) + 1); 662 } 663