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  * @(#)strptime.c       0.1 (Powerdog) 94/03/27
  38  * @(#) Copyright (c) 1994 Powerdog Industries.  All rights reserved.
  39  * $FreeBSD: head/lib/libc/stdtime/strptime.c 272679 2014-10-07 06:34:05Z ache $
  40  */
  41
  42 #include "namespace.h"
  43 #include <time.h>
  44 #include <ctype.h>
  45 #include <errno.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <pthread.h>
  49 #include "un-namespace.h"
  50 #include "libc_private.h"
  51 #include "timelocal.h"
  52 #include "tzfile.h"
  53
  54 static char * _strptime(const char *, const char *, struct tm *, int *, locale_t);
  55
  56 #define asizeof(a)      (sizeof(a) / sizeof((a)[0]))
  57
  58 #define FLAG_NONE       (1 << 0)
  59 #define FLAG_YEAR       (1 << 1)
  60 #define FLAG_MONTH      (1 << 2)
  61 #define FLAG_YDAY       (1 << 3)
  62 #define FLAG_MDAY       (1 << 4)
  63 #define FLAG_WDAY       (1 << 5)
  64
  65 /*
  66  * Calculate the week day of the first day of a year. Valid for
  67  * the Gregorian calendar, which began Sept 14, 1752 in the UK
  68  * and its colonies. Ref:
  69  * http://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week
  70  */
  71
  72 static int
  73 first_wday_of(int year)
  74 {
  75         return (((2 * (3 - (year / 100) % 4)) + (year % 100) +
  76                 ((year % 100) / 4) + (isleap(year) ? 6 : 0) + 1) % 7);
  77 }
  78
  79 static char *
  80 _strptime(const char *buf, const char *fmt, struct tm *tm, int *GMTp,
  81                 locale_t locale)
  82 {
  83         char    c;
  84         const char *ptr;
  85         int     day_offset = -1, wday_offset;
  86         int week_offset;
  87         int     i, len;
  88         int flags;
  89         int Ealternative, Oalternative;
  90         const struct lc_time_T *tptr = __get_current_time_locale(locale);
  91         static int start_of_month[2][13] = {
  92                 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
  93                 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
  94         };
  95
  96         flags = FLAG_NONE;
  97
  98         ptr = fmt;
  99         while (*ptr != 0) {
 100                 c = *ptr++;
 101
 102                 if (c != '%') {
 103                         if (isspace_l((unsigned char)c, locale))
 104                                 while (*buf != 0 &&
 105                                        isspace_l((unsigned char)*buf, locale))
 106                                         buf++;
 107                         else if (c != *buf++)
 108                                 return (NULL);
 109                         continue;
 110                 }
 111
 112                 Ealternative = 0;
 113                 Oalternative = 0;
 114 label:
 115                 c = *ptr++;
 116                 switch (c) {
 117                 case '%':
 118                         if (*buf++ != '%')
 119                                 return (NULL);
 120                         break;
 121
 122                 case '+':
 123                         buf = _strptime(buf, tptr->date_fmt, tm, GMTp, locale);
 124                         if (buf == NULL)
 125                                 return (NULL);
 126                         flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 127                         break;
 128
 129                 case 'C':
 130                         if (!isdigit_l((unsigned char)*buf, locale))
 131                                 return (NULL);
 132
 133                         /* XXX This will break for 3-digit centuries. */
 134                         len = 2;
 135                         for (i = 0; len && *buf != 0 &&
 136                              isdigit_l((unsigned char)*buf, locale); buf++) {
 137                                 i *= 10;
 138                                 i += *buf - '0';
 139                                 len--;
 140                         }
 141                         if (i < 19)
 142                                 return (NULL);
 143
 144                         tm->tm_year = i * 100 - TM_YEAR_BASE;
 145                         flags |= FLAG_YEAR;
 146
 147                         break;
 148
 149                 case 'c':
 150                         buf = _strptime(buf, tptr->c_fmt, tm, GMTp, locale);
 151                         if (buf == NULL)
 152                                 return (NULL);
 153                         flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 154                         break;
 155
 156                 case 'D':
 157                         buf = _strptime(buf, "%m/%d/%y", tm, GMTp, locale);
 158                         if (buf == NULL)
 159                                 return (NULL);
 160                         flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 161                         break;
 162
 163                 case 'E':
 164                         if (Ealternative || Oalternative)
 165                                 break;
 166                         Ealternative++;
 167                         goto label;
 168
 169                 case 'O':
 170                         if (Ealternative || Oalternative)
 171                                 break;
 172                         Oalternative++;
 173                         goto label;
 174
 175                 case 'F':
 176                         buf = _strptime(buf, "%Y-%m-%d", tm, GMTp, locale);
 177                         if (buf == NULL)
 178                                 return (NULL);
 179                         flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 180                         break;
 181
 182                 case 'R':
 183                         buf = _strptime(buf, "%H:%M", tm, GMTp, locale);
 184                         if (buf == NULL)
 185                                 return (NULL);
 186                         break;
 187
 188                 case 'r':
 189                         buf = _strptime(buf, tptr->ampm_fmt, tm, GMTp, locale);
 190                         if (buf == NULL)
 191                                 return (NULL);
 192                         break;
 193
 194                 case 'T':
 195                         buf = _strptime(buf, "%H:%M:%S", tm, GMTp, locale);
 196                         if (buf == NULL)
 197                                 return (NULL);
 198                         break;
 199
 200                 case 'X':
 201                         buf = _strptime(buf, tptr->X_fmt, 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                         flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 211                         break;
 212
 213                 case 'j':
 214                         if (!isdigit_l((unsigned char)*buf, locale))
 215                                 return (NULL);
 216
 217                         len = 3;
 218                         for (i = 0; len && *buf != 0 &&
 219                              isdigit_l((unsigned char)*buf, locale); buf++){
 220                                 i *= 10;
 221                                 i += *buf - '0';
 222                                 len--;
 223                         }
 224                         if (i < 1 || i > 366)
 225                                 return (NULL);
 226
 227                         tm->tm_yday = i - 1;
 228                         flags |= FLAG_YDAY;
 229
 230                         break;
 231
 232                 case 'M':
 233                 case 'S':
 234                         if (*buf == 0 ||
 235                                 isspace_l((unsigned char)*buf, locale))
 236                                 break;
 237
 238                         if (!isdigit_l((unsigned char)*buf, locale))
 239                                 return (NULL);
 240
 241                         len = 2;
 242                         for (i = 0; len && *buf != 0 &&
 243                                 isdigit_l((unsigned char)*buf, locale); buf++){
 244                                 i *= 10;
 245                                 i += *buf - '0';
 246                                 len--;
 247                         }
 248
 249                         if (c == 'M') {
 250                                 if (i > 59)
 251                                         return (NULL);
 252                                 tm->tm_min = i;
 253                         } else {
 254                                 if (i > 60)
 255                                         return (NULL);
 256                                 tm->tm_sec = i;
 257                         }
 258
 259                         break;
 260
 261                 case 'H':
 262                 case 'I':
 263                 case 'k':
 264                 case 'l':
 265                         /*
 266                          * Of these, %l is the only specifier explicitly
 267                          * documented as not being zero-padded.  However,
 268                          * there is no harm in allowing zero-padding.
 269                          *
 270                          * XXX The %l specifier may gobble one too many
 271                          * digits if used incorrectly.
 272                          */
 273                         if (!isdigit_l((unsigned char)*buf, locale))
 274                                 return (NULL);
 275
 276                         len = 2;
 277                         for (i = 0; len && *buf != 0 &&
 278                              isdigit_l((unsigned char)*buf, locale); buf++) {
 279                                 i *= 10;
 280                                 i += *buf - '0';
 281                                 len--;
 282                         }
 283                         if (c == 'H' || c == 'k') {
 284                                 if (i > 23)
 285                                         return (NULL);
 286                         } else if (i > 12)
 287                                 return (NULL);
 288
 289                         tm->tm_hour = i;
 290
 291                         break;
 292
 293                 case 'p':
 294                         /*
 295                          * XXX This is bogus if parsed before hour-related
 296                          * specifiers.
 297                          */
 298                         len = strlen(tptr->am);
 299                         if (strncasecmp_l(buf, tptr->am, len, locale) == 0) {
 300                                 if (tm->tm_hour > 12)
 301                                         return (NULL);
 302                                 if (tm->tm_hour == 12)
 303                                         tm->tm_hour = 0;
 304                                 buf += len;
 305                                 break;
 306                         }
 307
 308                         len = strlen(tptr->pm);
 309                         if (strncasecmp_l(buf, tptr->pm, len, locale) == 0) {
 310                                 if (tm->tm_hour > 12)
 311                                         return (NULL);
 312                                 if (tm->tm_hour != 12)
 313                                         tm->tm_hour += 12;
 314                                 buf += len;
 315                                 break;
 316                         }
 317
 318                         return (NULL);
 319
 320                 case 'A':
 321                 case 'a':
 322                         for (i = 0; i < asizeof(tptr->weekday); i++) {
 323                                 len = strlen(tptr->weekday[i]);
 324                                 if (strncasecmp_l(buf, tptr->weekday[i],
 325                                                 len, locale) == 0)
 326                                         break;
 327                                 len = strlen(tptr->wday[i]);
 328                                 if (strncasecmp_l(buf, tptr->wday[i],
 329                                                 len, locale) == 0)
 330                                         break;
 331                         }
 332                         if (i == asizeof(tptr->weekday))
 333                                 return (NULL);
 334
 335                         buf += len;
 336                         tm->tm_wday = i;
 337                         flags |= FLAG_WDAY;
 338                         break;
 339
 340                 case 'U':
 341                 case 'W':
 342                         /*
 343                          * XXX This is bogus, as we can not assume any valid
 344                          * information present in the tm structure at this
 345                          * point to calculate a real value, so just check the
 346                          * range for now.
 347                          */
 348                         if (!isdigit_l((unsigned char)*buf, locale))
 349                                 return (NULL);
 350
 351                         len = 2;
 352                         for (i = 0; len && *buf != 0 &&
 353                              isdigit_l((unsigned char)*buf, locale); buf++) {
 354                                 i *= 10;
 355                                 i += *buf - '0';
 356                                 len--;
 357                         }
 358                         if (i > 53)
 359                                 return (NULL);
 360
 361                         if (c == 'U')
 362                                 day_offset = TM_SUNDAY;
 363                         else
 364                                 day_offset = TM_MONDAY;
 365
 366
 367                         week_offset = i;
 368
 369                         break;
 370
 371                 case 'w':
 372                         if (!isdigit_l((unsigned char)*buf, locale))
 373                                 return (NULL);
 374
 375                         i = *buf - '0';
 376                         if (i > 6)
 377                                 return (NULL);
 378
 379                         tm->tm_wday = i;
 380                         flags |= FLAG_WDAY;
 381
 382                         break;
 383
 384                 case 'e':
 385                         /*
 386                          * With %e format, our strftime(3) adds a blank space
 387                          * before single digits.
 388                          */
 389                         if (*buf != 0 &&
 390                             isspace_l((unsigned char)*buf, locale))
 391                                buf++;
 392                         /* FALLTHROUGH */
 393                 case 'd':
 394                         /*
 395                          * The %e specifier was once explicitly documented as
 396                          * not being zero-padded but was later changed to
 397                          * equivalent to %d.  There is no harm in allowing
 398                          * such padding.
 399                          *
 400                          * XXX The %e specifier may gobble one too many
 401                          * digits if used incorrectly.
 402                          */
 403                         if (!isdigit_l((unsigned char)*buf, locale))
 404                                 return (NULL);
 405
 406                         len = 2;
 407                         for (i = 0; len && *buf != 0 &&
 408                              isdigit_l((unsigned char)*buf, locale); buf++) {
 409                                 i *= 10;
 410                                 i += *buf - '0';
 411                                 len--;
 412                         }
 413                         if (i > 31)
 414                                 return (NULL);
 415
 416                         tm->tm_mday = i;
 417                         flags |= FLAG_MDAY;
 418
 419                         break;
 420
 421                 case 'B':
 422                 case 'b':
 423                 case 'h':
 424                         for (i = 0; i < asizeof(tptr->month); i++) {
 425                                 if (Oalternative) {
 426                                         if (c == 'B') {
 427                                                 len = strlen(tptr->alt_month[i]);
 428                                                 if (strncasecmp_l(buf,
 429                                                                 tptr->alt_month[i],
 430                                                                 len, locale) == 0)
 431                                                         break;
 432                                         }
 433                                 } else {
 434                                         len = strlen(tptr->month[i]);
 435                                         if (strncasecmp_l(buf, tptr->month[i],
 436                                                         len, locale) == 0)
 437                                                 break;
 438                                 }
 439                         }
 440                         /*
 441                          * Try the abbreviated month name if the full name
 442                          * wasn't found and Oalternative was not requested.
 443                          */
 444                         if (i == asizeof(tptr->month) && !Oalternative) {
 445                                 for (i = 0; i < asizeof(tptr->month); i++) {
 446                                         len = strlen(tptr->mon[i]);
 447                                         if (strncasecmp_l(buf, tptr->mon[i],
 448                                                         len, locale) == 0)
 449                                                 break;
 450                                 }
 451                         }
 452                         if (i == asizeof(tptr->month))
 453                                 return (NULL);
 454
 455                         tm->tm_mon = i;
 456                         buf += len;
 457                         flags |= FLAG_MONTH;
 458
 459                         break;
 460
 461                 case 'm':
 462                         if (!isdigit_l((unsigned char)*buf, locale))
 463                                 return (NULL);
 464
 465                         len = 2;
 466                         for (i = 0; len && *buf != 0 &&
 467                              isdigit_l((unsigned char)*buf, locale); buf++) {
 468                                 i *= 10;
 469                                 i += *buf - '0';
 470                                 len--;
 471                         }
 472                         if (i < 1 || i > 12)
 473                                 return (NULL);
 474
 475                         tm->tm_mon = i - 1;
 476                         flags |= FLAG_MONTH;
 477
 478                         break;
 479
 480                 case 's':
 481                         {
 482                         char *cp;
 483                         int sverrno;
 484                         long n;
 485                         time_t t;
 486
 487                         sverrno = errno;
 488                         errno = 0;
 489                         n = strtol_l(buf, &cp, 10, locale);
 490                         if (errno == ERANGE || (long)(t = n) != n) {
 491                                 errno = sverrno;
 492                                 return (NULL);
 493                         }
 494                         errno = sverrno;
 495                         buf = cp;
 496                         if (gmtime_r(&t, tm) == NULL)
 497                                 return (NULL);
 498                         *GMTp = 1;
 499                         flags |= FLAG_YDAY | FLAG_WDAY | FLAG_MONTH |
 500                             FLAG_MDAY | FLAG_YEAR;
 501                         }
 502                         break;
 503
 504                 case 'Y':
 505                 case 'y':
 506                         if (*buf == 0 ||
 507                             isspace_l((unsigned char)*buf, locale))
 508                                 break;
 509
 510                         if (!isdigit_l((unsigned char)*buf, locale))
 511                                 return (NULL);
 512
 513                         len = (c == 'Y') ? 4 : 2;
 514                         for (i = 0; len && *buf != 0 &&
 515                              isdigit_l((unsigned char)*buf, locale); buf++) {
 516                                 i *= 10;
 517                                 i += *buf - '0';
 518                                 len--;
 519                         }
 520                         if (c == 'Y')
 521                                 i -= TM_YEAR_BASE;
 522                         if (c == 'y' && i < 69)
 523                                 i += 100;
 524                         if (i < 0)
 525                                 return (NULL);
 526
 527                         tm->tm_year = i;
 528                         flags |= FLAG_YEAR;
 529
 530                         break;
 531
 532                 case 'Z':
 533                         {
 534                         const char *cp;
 535                         char *zonestr;
 536
 537                         for (cp = buf; *cp &&
 538                              isupper_l((unsigned char)*cp, locale); ++cp) {
 539                                 /*empty*/}
 540                         if (cp - buf) {
 541                                 zonestr = alloca(cp - buf + 1);
 542                                 strncpy(zonestr, buf, cp - buf);
 543                                 zonestr[cp - buf] = '\0';
 544                                 tzset();
 545                                 if (0 == strcmp(zonestr, "GMT") ||
 546                                     0 == strcmp(zonestr, "UTC")) {
 547                                     *GMTp = 1;
 548                                 } else if (0 == strcmp(zonestr, tzname[0])) {
 549                                     tm->tm_isdst = 0;
 550                                 } else if (0 == strcmp(zonestr, tzname[1])) {
 551                                     tm->tm_isdst = 1;
 552                                 } else {
 553                                     return (NULL);
 554                                 }
 555                                 buf += cp - buf;
 556                         }
 557                         }
 558                         break;
 559
 560                 case 'z':
 561                         {
 562                         int sign = 1;
 563
 564                         if (*buf != '+') {
 565                                 if (*buf == '-')
 566                                         sign = -1;
 567                                 else
 568                                         return (NULL);
 569                         }
 570
 571                         buf++;
 572                         i = 0;
 573                         for (len = 4; len > 0; len--) {
 574                                 if (isdigit_l((unsigned char)*buf, locale)) {
 575                                         i *= 10;
 576                                         i += *buf - '0';
 577                                         buf++;
 578                                 } else
 579                                         return (NULL);
 580                         }
 581
 582                         tm->tm_hour -= sign * (i / 100);
 583                         tm->tm_min  -= sign * (i % 100);
 584                         *GMTp = 1;
 585                         }
 586                         break;
 587
 588                 case 'n':
 589                 case 't':
 590                         while (isspace_l((unsigned char)*buf, locale))
 591                                 buf++;
 592                         break;
 593
 594                 default:
 595                         return (NULL);
 596                 }
 597         }
 598
 599         if (!(flags & FLAG_YDAY) && (flags & FLAG_YEAR)) {
 600                 if ((flags & (FLAG_MONTH | FLAG_MDAY)) ==
 601                     (FLAG_MONTH | FLAG_MDAY)) {
 602                         tm->tm_yday = start_of_month[isleap(tm->tm_year +
 603                             TM_YEAR_BASE)][tm->tm_mon] + (tm->tm_mday - 1);
 604                         flags |= FLAG_YDAY;
 605                 } else if (day_offset != -1) {
 606                         /* Set the date to the first Sunday (or Monday)
 607                          * of the specified week of the year.
 608                          */
 609                         if (!(flags & FLAG_WDAY)) {
 610                                 tm->tm_wday = day_offset;
 611                                 flags |= FLAG_WDAY;
 612                         }
 613                         tm->tm_yday = (7 -
 614                             first_wday_of(tm->tm_year + TM_YEAR_BASE) +
 615                             day_offset) % 7 + (week_offset - 1) * 7 +
 616                             tm->tm_wday - day_offset;
 617                         flags |= FLAG_YDAY;
 618                 }
 619         }
 620
 621         if ((flags & (FLAG_YEAR | FLAG_YDAY)) == (FLAG_YEAR | FLAG_YDAY)) {
 622                 if (!(flags & FLAG_MONTH)) {
 623                         i = 0;
 624                         while (tm->tm_yday >=
 625                             start_of_month[isleap(tm->tm_year +
 626                             TM_YEAR_BASE)][i])
 627                                 i++;
 628                         if (i > 12) {
 629                                 i = 1;
 630                                 tm->tm_yday -=
 631                                     start_of_month[isleap(tm->tm_year +
 632                                     TM_YEAR_BASE)][12];
 633                                 tm->tm_year++;
 634                         }
 635                         tm->tm_mon = i - 1;
 636                         flags |= FLAG_MONTH;
 637                 }
 638                 if (!(flags & FLAG_MDAY)) {
 639                         tm->tm_mday = tm->tm_yday -
 640                             start_of_month[isleap(tm->tm_year + TM_YEAR_BASE)]
 641                             [tm->tm_mon] + 1;
 642                         flags |= FLAG_MDAY;
 643                 }
 644                 if (!(flags & FLAG_WDAY)) {
 645                         i = 0;
 646                         wday_offset = first_wday_of(tm->tm_year);
 647                         while (i++ <= tm->tm_yday) {
 648                                 if (wday_offset++ >= 6)
 649                                         wday_offset = 0;
 650                         }
 651                         tm->tm_wday = wday_offset;
 652                         flags |= FLAG_WDAY;
 653                 }
 654         }
 655
 656         return ((char *)buf);
 657 }
 658
 659 char *
 660 strptime_l(const char * __restrict buf, const char * __restrict fmt,
 661     struct tm * __restrict tm, locale_t loc)
 662 {
 663         char *ret;
 664         int gmt;
 665         FIX_LOCALE(loc);
 666
 667         gmt = 0;
 668         ret = _strptime(buf, fmt, tm, &gmt, loc);
 669         if (ret && gmt) {
 670                 time_t t = timegm(tm);
 671
 672                 localtime_r(&t, tm);
 673         }
 674
 675         return (ret);
 676 }
 677
 678 char *
 679 strptime(const char * __restrict buf, const char * __restrict fmt,
 680     struct tm * __restrict tm)
 681 {
 682         return strptime_l(buf, fmt, tm, __get_locale());
 683 }