lib/libc/stdtime/strptime.c

   1 /*-
   2  * Copyright (c) 2014 Gary Mills
   3  * Copyright 2011, Nexenta Systems, Inc.  All rights reserved.
   4  * Copyright (c) 1994 Powerdog Industries.  All rights reserved.
   5  *
   6  * Copyright (c) 2011 The FreeBSD Foundation
   7  * All rights reserved.
   8  * Portions of this software were developed by David Chisnall
   9  * under sponsorship from the FreeBSD Foundation.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer
  18  *    in the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY POWERDOG INDUSTRIES ``AS IS'' AND ANY
  22  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE POWERDOG INDUSTRIES BE
  25  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  28  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  30  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  31  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  *
  33  * The views and conclusions contained in the software and documentation
  34  * are those of the authors and should not be interpreted as representing
  35  * official policies, either expressed or implied, of Powerdog Industries.
  36  */
  37
  38 #include <sys/cdefs.h>
  39 #ifndef lint
  40 #ifndef NOID
  41 static char copyright[] __unused =
  42 "@(#) Copyright (c) 1994 Powerdog Industries.  All rights reserved.";
  43 static char sccsid[] __unused = "@(#)strptime.c 0.1 (Powerdog) 94/03/27";
  44 #endif /* !defined NOID */
  45 #endif /* not lint */
  46 __FBSDID("$FreeBSD$");
  47
  48 #include "namespace.h"
  49 #include <time.h>
  50 #include <ctype.h>
  51 #include <errno.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <pthread.h>
  55 #include "un-namespace.h"
  56 #include "libc_private.h"
  57 #include "timelocal.h"
  58 #include "tzfile.h"
  59
  60 static char * _strptime(const char *, const char *, struct tm *, int *, locale_t);
  61
  62 #define asizeof(a)      (sizeof(a) / sizeof((a)[0]))
  63
  64 #define FLAG_NONE       (1 << 0)
  65 #define FLAG_YEAR       (1 << 1)
  66 #define FLAG_MONTH      (1 << 2)
  67 #define FLAG_YDAY       (1 << 3)
  68 #define FLAG_MDAY       (1 << 4)
  69 #define FLAG_WDAY       (1 << 5)
  70
  71 /*
  72  * Calculate the week day of the first day of a year. Valid for
  73  * the Gregorian calendar, which began Sept 14, 1752 in the UK
  74  * and its colonies. Ref:
  75  * http://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week
  76  */
  77
  78 static int
  79 first_wday_of(int year)
  80 {
  81         return (((2 * (3 - (year / 100) % 4)) + (year % 100) +
  82                 ((year % 100) / 4) + (isleap(year) ? 6 : 0) + 1) % 7);
  83 }
  84
  85 static char *
  86 _strptime(const char *buf, const char *fmt, struct tm *tm, int *GMTp,
  87                 locale_t locale)
  88 {
  89         char    c;
  90         const char *ptr;
  91         int     day_offset = -1, wday_offset;
  92         int week_offset;
  93         int     i, len;
  94         int flags;
  95         int Ealternative, Oalternative;
  96         const struct lc_time_T *tptr = __get_current_time_locale(locale);
  97         static int start_of_month[2][13] = {
  98                 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
  99                 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
 100         };
 101
 102         flags = FLAG_NONE;
 103
 104         ptr = fmt;
 105         while (*ptr != 0) {
 106                 c = *ptr++;
 107
 108                 if (c != '%') {
 109                         if (isspace_l((unsigned char)c, locale))
 110                                 while (*buf != 0 &&
 111                                        isspace_l((unsigned char)*buf, locale))
 112                                         buf++;
 113                         else if (c != *buf++)
 114                                 return (NULL);
 115                         continue;
 116                 }
 117
 118                 Ealternative = 0;
 119                 Oalternative = 0;
 120 label:
 121                 c = *ptr++;
 122                 switch (c) {
 123                 case '%':
 124                         if (*buf++ != '%')
 125                                 return (NULL);
 126                         break;
 127
 128                 case '+':
 129                         buf = _strptime(buf, tptr->date_fmt, tm, GMTp, locale);
 130                         if (buf == NULL)
 131                                 return (NULL);
 132                         flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 133                         break;
 134
 135                 case 'C':
 136                         if (!isdigit_l((unsigned char)*buf, locale))
 137                                 return (NULL);
 138
 139                         /* XXX This will break for 3-digit centuries. */
 140                         len = 2;
 141                         for (i = 0; len && *buf != 0 &&
 142                              isdigit_l((unsigned char)*buf, locale); buf++) {
 143                                 i *= 10;
 144                                 i += *buf - '0';
 145                                 len--;
 146                         }
 147                         if (i < 19)
 148                                 return (NULL);
 149
 150                         tm->tm_year = i * 100 - TM_YEAR_BASE;
 151                         flags |= FLAG_YEAR;
 152
 153                         break;
 154
 155                 case 'c':
 156                         buf = _strptime(buf, tptr->c_fmt, tm, GMTp, locale);
 157                         if (buf == NULL)
 158                                 return (NULL);
 159                         flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 160                         break;
 161
 162                 case 'D':
 163                         buf = _strptime(buf, "%m/%d/%y", tm, GMTp, locale);
 164                         if (buf == NULL)
 165                                 return (NULL);
 166                         flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 167                         break;
 168
 169                 case 'E':
 170                         if (Ealternative || Oalternative)
 171                                 break;
 172                         Ealternative++;
 173                         goto label;
 174
 175                 case 'O':
 176                         if (Ealternative || Oalternative)
 177                                 break;
 178                         Oalternative++;
 179                         goto label;
 180
 181                 case 'F':
 182                         buf = _strptime(buf, "%Y-%m-%d", tm, GMTp, locale);
 183                         if (buf == NULL)
 184                                 return (NULL);
 185                         flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 186                         break;
 187
 188                 case 'R':
 189                         buf = _strptime(buf, "%H:%M", tm, GMTp, locale);
 190                         if (buf == NULL)
 191                                 return (NULL);
 192                         break;
 193
 194                 case 'r':
 195                         buf = _strptime(buf, tptr->ampm_fmt, tm, GMTp, locale);
 196                         if (buf == NULL)
 197                                 return (NULL);
 198                         break;
 199
 200                 case 'T':
 201                         buf = _strptime(buf, "%H:%M:%S", tm, GMTp, locale);
 202                         if (buf == NULL)
 203                                 return (NULL);
 204                         break;
 205
 206                 case 'X':
 207                         buf = _strptime(buf, tptr->X_fmt, tm, GMTp, locale);
 208                         if (buf == NULL)
 209                                 return (NULL);
 210                         break;
 211
 212                 case 'x':
 213                         buf = _strptime(buf, tptr->x_fmt, tm, GMTp, locale);
 214                         if (buf == NULL)
 215                                 return (NULL);
 216                         flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 217                         break;
 218
 219                 case 'j':
 220                         if (!isdigit_l((unsigned char)*buf, locale))
 221                                 return (NULL);
 222
 223                         len = 3;
 224                         for (i = 0; len && *buf != 0 &&
 225                              isdigit_l((unsigned char)*buf, locale); buf++){
 226                                 i *= 10;
 227                                 i += *buf - '0';
 228                                 len--;
 229                         }
 230                         if (i < 1 || i > 366)
 231                                 return (NULL);
 232
 233                         tm->tm_yday = i - 1;
 234                         flags |= FLAG_YDAY;
 235
 236                         break;
 237
 238                 case 'M':
 239                 case 'S':
 240                         if (*buf == 0 ||
 241                                 isspace_l((unsigned char)*buf, locale))
 242                                 break;
 243
 244                         if (!isdigit_l((unsigned char)*buf, locale))
 245                                 return (NULL);
 246
 247                         len = 2;
 248                         for (i = 0; len && *buf != 0 &&
 249                                 isdigit_l((unsigned char)*buf, locale); buf++){
 250                                 i *= 10;
 251                                 i += *buf - '0';
 252                                 len--;
 253                         }
 254
 255                         if (c == 'M') {
 256                                 if (i > 59)
 257                                         return (NULL);
 258                                 tm->tm_min = i;
 259                         } else {
 260                                 if (i > 60)
 261                                         return (NULL);
 262                                 tm->tm_sec = i;
 263                         }
 264
 265                         break;
 266
 267                 case 'H':
 268                 case 'I':
 269                 case 'k':
 270                 case 'l':
 271                         /*
 272                          * Of these, %l is the only specifier explicitly
 273                          * documented as not being zero-padded.  However,
 274                          * there is no harm in allowing zero-padding.
 275                          *
 276                          * XXX The %l specifier may gobble one too many
 277                          * digits if used incorrectly.
 278                          */
 279                         if (!isdigit_l((unsigned char)*buf, locale))
 280                                 return (NULL);
 281
 282                         len = 2;
 283                         for (i = 0; len && *buf != 0 &&
 284                              isdigit_l((unsigned char)*buf, locale); buf++) {
 285                                 i *= 10;
 286                                 i += *buf - '0';
 287                                 len--;
 288                         }
 289                         if (c == 'H' || c == 'k') {
 290                                 if (i > 23)
 291                                         return (NULL);
 292                         } else if (i > 12)
 293                                 return (NULL);
 294
 295                         tm->tm_hour = i;
 296
 297                         break;
 298
 299                 case 'p':
 300                         /*
 301                          * XXX This is bogus if parsed before hour-related
 302                          * specifiers.
 303                          */
 304                         len = strlen(tptr->am);
 305                         if (strncasecmp_l(buf, tptr->am, len, locale) == 0) {
 306                                 if (tm->tm_hour > 12)
 307                                         return (NULL);
 308                                 if (tm->tm_hour == 12)
 309                                         tm->tm_hour = 0;
 310                                 buf += len;
 311                                 break;
 312                         }
 313
 314                         len = strlen(tptr->pm);
 315                         if (strncasecmp_l(buf, tptr->pm, len, locale) == 0) {
 316                                 if (tm->tm_hour > 12)
 317                                         return (NULL);
 318                                 if (tm->tm_hour != 12)
 319                                         tm->tm_hour += 12;
 320                                 buf += len;
 321                                 break;
 322                         }
 323
 324                         return (NULL);
 325
 326                 case 'A':
 327                 case 'a':
 328                         for (i = 0; i < asizeof(tptr->weekday); i++) {
 329                                 len = strlen(tptr->weekday[i]);
 330                                 if (strncasecmp_l(buf, tptr->weekday[i],
 331                                                 len, locale) == 0)
 332                                         break;
 333                                 len = strlen(tptr->wday[i]);
 334                                 if (strncasecmp_l(buf, tptr->wday[i],
 335                                                 len, locale) == 0)
 336                                         break;
 337                         }
 338                         if (i == asizeof(tptr->weekday))
 339                                 return (NULL);
 340
 341                         buf += len;
 342                         tm->tm_wday = i;
 343                         flags |= FLAG_WDAY;
 344                         break;
 345
 346                 case 'U':
 347                 case 'W':
 348                         /*
 349                          * XXX This is bogus, as we can not assume any valid
 350                          * information present in the tm structure at this
 351                          * point to calculate a real value, so just check the
 352                          * range for now.
 353                          */
 354                         if (!isdigit_l((unsigned char)*buf, locale))
 355                                 return (NULL);
 356
 357                         len = 2;
 358                         for (i = 0; len && *buf != 0 &&
 359                              isdigit_l((unsigned char)*buf, locale); buf++) {
 360                                 i *= 10;
 361                                 i += *buf - '0';
 362                                 len--;
 363                         }
 364                         if (i > 53)
 365                                 return (NULL);
 366
 367                         if (c == 'U')
 368                                 day_offset = TM_SUNDAY;
 369                         else
 370                                 day_offset = TM_MONDAY;
 371
 372
 373                         week_offset = i;
 374
 375                         break;
 376
 377                 case 'w':
 378                         if (!isdigit_l((unsigned char)*buf, locale))
 379                                 return (NULL);
 380
 381                         i = *buf - '0';
 382                         if (i > 6)
 383                                 return (NULL);
 384
 385                         tm->tm_wday = i;
 386                         flags |= FLAG_WDAY;
 387
 388                         break;
 389
 390                 case 'e':
 391                         /*
 392                          * With %e format, our strftime(3) adds a blank space
 393                          * before single digits.
 394                          */
 395                         if (*buf != 0 &&
 396                             isspace_l((unsigned char)*buf, locale))
 397                                buf++;
 398                         /* FALLTHROUGH */
 399                 case 'd':
 400                         /*
 401                          * The %e specifier was once explicitly documented as
 402                          * not being zero-padded but was later changed to
 403                          * equivalent to %d.  There is no harm in allowing
 404                          * such padding.
 405                          *
 406                          * XXX The %e specifier may gobble one too many
 407                          * digits if used incorrectly.
 408                          */
 409                         if (!isdigit_l((unsigned char)*buf, locale))
 410                                 return (NULL);
 411
 412                         len = 2;
 413                         for (i = 0; len && *buf != 0 &&
 414                              isdigit_l((unsigned char)*buf, locale); buf++) {
 415                                 i *= 10;
 416                                 i += *buf - '0';
 417                                 len--;
 418                         }
 419                         if (i > 31)
 420                                 return (NULL);
 421
 422                         tm->tm_mday = i;
 423                         flags |= FLAG_MDAY;
 424
 425                         break;
 426
 427                 case 'B':
 428                 case 'b':
 429                 case 'h':
 430                         for (i = 0; i < asizeof(tptr->month); i++) {
 431                                 if (Oalternative) {
 432                                         if (c == 'B') {
 433                                                 len = strlen(tptr->alt_month[i]);
 434                                                 if (strncasecmp_l(buf,
 435                                                                 tptr->alt_month[i],
 436                                                                 len, locale) == 0)
 437                                                         break;
 438                                         }
 439                                 } else {
 440                                         len = strlen(tptr->month[i]);
 441                                         if (strncasecmp_l(buf, tptr->month[i],
 442                                                         len, locale) == 0)
 443                                                 break;
 444                                 }
 445                         }
 446                         /*
 447                          * Try the abbreviated month name if the full name
 448                          * wasn't found and Oalternative was not requested.
 449                          */
 450                         if (i == asizeof(tptr->month) && !Oalternative) {
 451                                 for (i = 0; i < asizeof(tptr->month); i++) {
 452                                         len = strlen(tptr->mon[i]);
 453                                         if (strncasecmp_l(buf, tptr->mon[i],
 454                                                         len, locale) == 0)
 455                                                 break;
 456                                 }
 457                         }
 458                         if (i == asizeof(tptr->month))
 459                                 return (NULL);
 460
 461                         tm->tm_mon = i;
 462                         buf += len;
 463                         flags |= FLAG_MONTH;
 464
 465                         break;
 466
 467                 case 'm':
 468                         if (!isdigit_l((unsigned char)*buf, locale))
 469                                 return (NULL);
 470
 471                         len = 2;
 472                         for (i = 0; len && *buf != 0 &&
 473                              isdigit_l((unsigned char)*buf, locale); buf++) {
 474                                 i *= 10;
 475                                 i += *buf - '0';
 476                                 len--;
 477                         }
 478                         if (i < 1 || i > 12)
 479                                 return (NULL);
 480
 481                         tm->tm_mon = i - 1;
 482                         flags |= FLAG_MONTH;
 483
 484                         break;
 485
 486                 case 's':
 487                         {
 488                         char *cp;
 489                         int sverrno;
 490                         long n;
 491                         time_t t;
 492
 493                         sverrno = errno;
 494                         errno = 0;
 495                         n = strtol_l(buf, &cp, 10, locale);
 496                         if (errno == ERANGE || (long)(t = n) != n) {
 497                                 errno = sverrno;
 498                                 return (NULL);
 499                         }
 500                         errno = sverrno;
 501                         buf = cp;
 502                         if (gmtime_r(&t, tm) == NULL)
 503                                 return (NULL);
 504                         *GMTp = 1;
 505                         flags |= FLAG_YDAY | FLAG_WDAY | FLAG_MONTH |
 506                             FLAG_MDAY | FLAG_YEAR;
 507                         }
 508                         break;
 509
 510                 case 'Y':
 511                 case 'y':
 512                         if (*buf == 0 ||
 513                             isspace_l((unsigned char)*buf, locale))
 514                                 break;
 515
 516                         if (!isdigit_l((unsigned char)*buf, locale))
 517                                 return (NULL);
 518
 519                         len = (c == 'Y') ? 4 : 2;
 520                         for (i = 0; len && *buf != 0 &&
 521                              isdigit_l((unsigned char)*buf, locale); buf++) {
 522                                 i *= 10;
 523                                 i += *buf - '0';
 524                                 len--;
 525                         }
 526                         if (c == 'Y')
 527                                 i -= TM_YEAR_BASE;
 528                         if (c == 'y' && i < 69)
 529                                 i += 100;
 530                         if (i < 0)
 531                                 return (NULL);
 532
 533                         tm->tm_year = i;
 534                         flags |= FLAG_YEAR;
 535
 536                         break;
 537
 538                 case 'Z':
 539                         {
 540                         const char *cp;
 541                         char *zonestr;
 542
 543                         for (cp = buf; *cp &&
 544                              isupper_l((unsigned char)*cp, locale); ++cp) {
 545                                 /*empty*/}
 546                         if (cp - buf) {
 547                                 zonestr = alloca(cp - buf + 1);
 548                                 strncpy(zonestr, buf, cp - buf);
 549                                 zonestr[cp - buf] = '\0';
 550                                 tzset();
 551                                 if (0 == strcmp(zonestr, "GMT") ||
 552                                     0 == strcmp(zonestr, "UTC")) {
 553                                     *GMTp = 1;
 554                                 } else if (0 == strcmp(zonestr, tzname[0])) {
 555                                     tm->tm_isdst = 0;
 556                                 } else if (0 == strcmp(zonestr, tzname[1])) {
 557                                     tm->tm_isdst = 1;
 558                                 } else {
 559                                     return (NULL);
 560                                 }
 561                                 buf += cp - buf;
 562                         }
 563                         }
 564                         break;
 565
 566                 case 'z':
 567                         {
 568                         int sign = 1;
 569
 570                         if (*buf != '+') {
 571                                 if (*buf == '-')
 572                                         sign = -1;
 573                                 else
 574                                         return (NULL);
 575                         }
 576
 577                         buf++;
 578                         i = 0;
 579                         for (len = 4; len > 0; len--) {
 580                                 if (isdigit_l((unsigned char)*buf, locale)) {
 581                                         i *= 10;
 582                                         i += *buf - '0';
 583                                         buf++;
 584                                 } else
 585                                         return (NULL);
 586                         }
 587
 588                         tm->tm_hour -= sign * (i / 100);
 589                         tm->tm_min  -= sign * (i % 100);
 590                         *GMTp = 1;
 591                         }
 592                         break;
 593
 594                 case 'n':
 595                 case 't':
 596                         while (isspace_l((unsigned char)*buf, locale))
 597                                 buf++;
 598                         break;
 599
 600                 default:
 601                         return (NULL);
 602                 }
 603         }
 604
 605         if (!(flags & FLAG_YDAY) && (flags & FLAG_YEAR)) {
 606                 if ((flags & (FLAG_MONTH | FLAG_MDAY)) ==
 607                     (FLAG_MONTH | FLAG_MDAY)) {
 608                         tm->tm_yday = start_of_month[isleap(tm->tm_year +
 609                             TM_YEAR_BASE)][tm->tm_mon] + (tm->tm_mday - 1);
 610                         flags |= FLAG_YDAY;
 611                 } else if (day_offset != -1) {
 612                         /* Set the date to the first Sunday (or Monday)
 613                          * of the specified week of the year.
 614                          */
 615                         if (!(flags & FLAG_WDAY)) {
 616                                 tm->tm_wday = day_offset;
 617                                 flags |= FLAG_WDAY;
 618                         }
 619                         tm->tm_yday = (7 -
 620                             first_wday_of(tm->tm_year + TM_YEAR_BASE) +
 621                             day_offset) % 7 + (week_offset - 1) * 7 +
 622                             tm->tm_wday - day_offset;
 623                         flags |= FLAG_YDAY;
 624                 }
 625         }
 626
 627         if ((flags & (FLAG_YEAR | FLAG_YDAY)) == (FLAG_YEAR | FLAG_YDAY)) {
 628                 if (!(flags & FLAG_MONTH)) {
 629                         i = 0;
 630                         while (tm->tm_yday >=
 631                             start_of_month[isleap(tm->tm_year +
 632                             TM_YEAR_BASE)][i])
 633                                 i++;
 634                         if (i > 12) {
 635                                 i = 1;
 636                                 tm->tm_yday -=
 637                                     start_of_month[isleap(tm->tm_year +
 638                                     TM_YEAR_BASE)][12];
 639                                 tm->tm_year++;
 640                         }
 641                         tm->tm_mon = i - 1;
 642                         flags |= FLAG_MONTH;
 643                 }
 644                 if (!(flags & FLAG_MDAY)) {
 645                         tm->tm_mday = tm->tm_yday -
 646                             start_of_month[isleap(tm->tm_year + TM_YEAR_BASE)]
 647                             [tm->tm_mon] + 1;
 648                         flags |= FLAG_MDAY;
 649                 }
 650                 if (!(flags & FLAG_WDAY)) {
 651                         i = 0;
 652                         wday_offset = first_wday_of(tm->tm_year);
 653                         while (i++ <= tm->tm_yday) {
 654                                 if (wday_offset++ >= 6)
 655                                         wday_offset = 0;
 656                         }
 657                         tm->tm_wday = wday_offset;
 658                         flags |= FLAG_WDAY;
 659                 }
 660         }
 661
 662         return ((char *)buf);
 663 }
 664
 665 char *
 666 strptime_l(const char * __restrict buf, const char * __restrict fmt,
 667     struct tm * __restrict tm, locale_t loc)
 668 {
 669         char *ret;
 670         int gmt;
 671         FIX_LOCALE(loc);
 672
 673         gmt = 0;
 674         ret = _strptime(buf, fmt, tm, &gmt, loc);
 675         if (ret && gmt) {
 676                 time_t t = timegm(tm);
 677
 678                 localtime_r(&t, tm);
 679         }
 680
 681         return (ret);
 682 }
 683
 684 char *
 685 strptime(const char * __restrict buf, const char * __restrict fmt,
 686     struct tm * __restrict tm)
 687 {
 688         return strptime_l(buf, fmt, tm, __get_locale());
 689 }