external/bsd/bind/dist/lib/isc/tm.c

   1 /*      $NetBSD: tm.c,v 1.1.1.3 2014/12/10 03:34:44 christos Exp $      */
   2
   3 /*
   4  * Copyright (C) 2014  Internet Systems Consortium, Inc. ("ISC")
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  11  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  12  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  13  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  14  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  15  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  16  * PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 /*-
  20  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
  21  * All rights reserved.
  22  *
  23  * This code was contributed to The NetBSD Foundation by Klaus Klein.
  24  *
  25  * Redistribution and use in source and binary forms, with or without
  26  * modification, are permitted provided that the following conditions
  27  * are met:
  28  * 1. Redistributions of source code must retain the above copyright
  29  *    notice, this list of conditions and the following disclaimer.
  30  * 2. Redistributions in binary form must reproduce the above copyright
  31  *    notice, this list of conditions and the following disclaimer in the
  32  *    documentation and/or other materials provided with the distribution.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  35  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  36  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  37  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  38  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  39  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  40  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  41  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  42  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  43  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  44  * POSSIBILITY OF SUCH DAMAGE.
  45  */
  46
  47 #include <config.h>
  48
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <time.h>
  53 #include <ctype.h>
  54
  55 #include <isc/tm.h>
  56 #include <isc/util.h>
  57
  58 /*
  59  * Portable conversion routines for struct tm, replacing
  60  * timegm() and strptime(), which are not available on all
  61  * platforms and don't always behave the same way when they
  62  * are.
  63  */
  64
  65 /*
  66  * We do not implement alternate representations. However, we always
  67  * check whether a given modifier is allowed for a certain conversion.
  68  */
  69 #define ALT_E                   0x01
  70 #define ALT_O                   0x02
  71 #define LEGAL_ALT(x)            { if (alt_format & ~(x)) return (0); }
  72
  73 #ifndef TM_YEAR_BASE
  74 #define TM_YEAR_BASE 1900
  75 #endif
  76
  77 static const char *day[7] = {
  78         "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday",
  79         "Friday", "Saturday"
  80 };
  81 static const char *abday[7] = {
  82         "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
  83 };
  84 static const char *mon[12] = {
  85         "January", "February", "March", "April", "May", "June", "July",
  86         "August", "September", "October", "November", "December"
  87 };
  88 static const char *abmon[12] = {
  89         "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  90         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
  91 };
  92 static const char *am_pm[2] = {
  93         "AM", "PM"
  94 };
  95
  96 static int
  97 conv_num(const char **buf, int *dest, int llim, int ulim) {
  98         int result = 0;
  99
 100         /* The limit also determines the number of valid digits. */
 101         int rulim = ulim;
 102
 103         if (**buf < '0' || **buf > '9')
 104                 return (0);
 105
 106         do {
 107                 result *= 10;
 108                 result += *(*buf)++ - '0';
 109                 rulim /= 10;
 110         } while ((result * 10 <= ulim) &&
 111                  rulim && **buf >= '0' && **buf <= '9');
 112
 113         if (result < llim || result > ulim)
 114                 return (0);
 115
 116         *dest = result;
 117         return (1);
 118 }
 119
 120 time_t
 121 isc_tm_timegm(struct tm *tm) {
 122         time_t ret;
 123         int i, yday = 0, leapday;
 124         int mdays[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30 };
 125
 126         leapday = ((((tm->tm_year + 1900 ) % 4) == 0 &&
 127                     ((tm->tm_year + 1900 ) % 100) != 0) ||
 128                    ((tm->tm_year + 1900 ) % 400) == 0) ? 1 : 0;
 129         mdays[1] += leapday;
 130
 131         yday = tm->tm_mday - 1;
 132         for (i = 1; i <= tm->tm_mon; i++)
 133                 yday += mdays[i - 1];
 134         ret = tm->tm_sec +
 135               (60 * tm->tm_min) +
 136               (3600 * tm->tm_hour) +
 137               (86400 * (yday +
 138                        ((tm->tm_year - 70) * 365) +
 139                        ((tm->tm_year - 69) / 4) -
 140                        ((tm->tm_year - 1) / 100) +
 141                        ((tm->tm_year + 299) / 400)));
 142         return (ret);
 143 }
 144
 145 char *
 146 isc_tm_strptime(const char *buf, const char *fmt, struct tm *tm) {
 147         char c, *ret;
 148         const char *bp;
 149         size_t len = 0;
 150         int alt_format, i, split_year = 0;
 151
 152         REQUIRE(buf != NULL);
 153         REQUIRE(fmt != NULL);
 154         REQUIRE(tm != NULL);
 155
 156         memset(tm, 0, sizeof(struct tm));
 157
 158         bp = buf;
 159
 160         while ((c = *fmt) != '\0') {
 161                 /* Clear `alternate' modifier prior to new conversion. */
 162                 alt_format = 0;
 163
 164                 /* Eat up white-space. */
 165                 if (isspace((unsigned char) c)) {
 166                         while (isspace((unsigned char) *bp))
 167                                 bp++;
 168
 169                         fmt++;
 170                         continue;
 171                 }
 172
 173                 if ((c = *fmt++) != '%')
 174                         goto literal;
 175
 176
 177 again:          switch (c = *fmt++) {
 178                 case '%':       /* "%%" is converted to "%". */
 179 literal:
 180                         if (c != *bp++)
 181                                 return (0);
 182                         break;
 183
 184                 /*
 185                  * "Alternative" modifiers. Just set the appropriate flag
 186                  * and start over again.
 187                  */
 188                 case 'E':       /* "%E?" alternative conversion modifier. */
 189                         LEGAL_ALT(0);
 190                         alt_format |= ALT_E;
 191                         goto again;
 192
 193                 case 'O':       /* "%O?" alternative conversion modifier. */
 194                         LEGAL_ALT(0);
 195                         alt_format |= ALT_O;
 196                         goto again;
 197
 198                 /*
 199                  * "Complex" conversion rules, implemented through recursion.
 200                  */
 201                 case 'c':       /* Date and time, using the locale's format. */
 202                         LEGAL_ALT(ALT_E);
 203                         if (!(bp = isc_tm_strptime(bp, "%x %X", tm)))
 204                                 return (0);
 205                         break;
 206
 207                 case 'D':       /* The date as "%m/%d/%y". */
 208                         LEGAL_ALT(0);
 209                         if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm)))
 210                                 return (0);
 211                         break;
 212
 213                 case 'R':       /* The time as "%H:%M". */
 214                         LEGAL_ALT(0);
 215                         if (!(bp = isc_tm_strptime(bp, "%H:%M", tm)))
 216                                 return (0);
 217                         break;
 218
 219                 case 'r':       /* The time in 12-hour clock representation. */
 220                         LEGAL_ALT(0);
 221                         if (!(bp = isc_tm_strptime(bp, "%I:%M:%S %p", tm)))
 222                                 return (0);
 223                         break;
 224
 225                 case 'T':       /* The time as "%H:%M:%S". */
 226                         LEGAL_ALT(0);
 227                         if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm)))
 228                                 return (0);
 229                         break;
 230
 231                 case 'X':       /* The time, using the locale's format. */
 232                         LEGAL_ALT(ALT_E);
 233                         if (!(bp = isc_tm_strptime(bp, "%H:%M:%S", tm)))
 234                                 return (0);
 235                         break;
 236
 237                 case 'x':       /* The date, using the locale's format. */
 238                         LEGAL_ALT(ALT_E);
 239                         if (!(bp = isc_tm_strptime(bp, "%m/%d/%y", tm)))
 240                                 return (0);
 241                         break;
 242
 243                 /*
 244                  * "Elementary" conversion rules.
 245                  */
 246                 case 'A':       /* The day of week, using the locale's form. */
 247                 case 'a':
 248                         LEGAL_ALT(0);
 249                         for (i = 0; i < 7; i++) {
 250                                 /* Full name. */
 251                                 len = strlen(day[i]);
 252                                 if (strncasecmp(day[i], bp, len) == 0)
 253                                         break;
 254
 255                                 /* Abbreviated name. */
 256                                 len = strlen(abday[i]);
 257                                 if (strncasecmp(abday[i], bp, len) == 0)
 258                                         break;
 259                         }
 260
 261                         /* Nothing matched. */
 262                         if (i == 7)
 263                                 return (0);
 264
 265                         tm->tm_wday = i;
 266                         bp += len;
 267                         break;
 268
 269                 case 'B':       /* The month, using the locale's form. */
 270                 case 'b':
 271                 case 'h':
 272                         LEGAL_ALT(0);
 273                         for (i = 0; i < 12; i++) {
 274                                 /* Full name. */
 275                                 len = strlen(mon[i]);
 276                                 if (strncasecmp(mon[i], bp, len) == 0)
 277                                         break;
 278
 279                                 /* Abbreviated name. */
 280                                 len = strlen(abmon[i]);
 281                                 if (strncasecmp(abmon[i], bp, len) == 0)
 282                                         break;
 283                         }
 284
 285                         /* Nothing matched. */
 286                         if (i == 12)
 287                                 return (0);
 288
 289                         tm->tm_mon = i;
 290                         bp += len;
 291                         break;
 292
 293                 case 'C':       /* The century number. */
 294                         LEGAL_ALT(ALT_E);
 295                         if (!(conv_num(&bp, &i, 0, 99)))
 296                                 return (0);
 297
 298                         if (split_year) {
 299                                 tm->tm_year = (tm->tm_year % 100) + (i * 100);
 300                         } else {
 301                                 tm->tm_year = i * 100;
 302                                 split_year = 1;
 303                         }
 304                         break;
 305
 306                 case 'd':       /* The day of month. */
 307                 case 'e':
 308                         LEGAL_ALT(ALT_O);
 309                         if (!(conv_num(&bp, &tm->tm_mday, 1, 31)))
 310                                 return (0);
 311                         break;
 312
 313                 case 'k':       /* The hour (24-hour clock representation). */
 314                         LEGAL_ALT(0);
 315                         /* FALLTHROUGH */
 316                 case 'H':
 317                         LEGAL_ALT(ALT_O);
 318                         if (!(conv_num(&bp, &tm->tm_hour, 0, 23)))
 319                                 return (0);
 320                         break;
 321
 322                 case 'l':       /* The hour (12-hour clock representation). */
 323                         LEGAL_ALT(0);
 324                         /* FALLTHROUGH */
 325                 case 'I':
 326                         LEGAL_ALT(ALT_O);
 327                         if (!(conv_num(&bp, &tm->tm_hour, 1, 12)))
 328                                 return (0);
 329                         if (tm->tm_hour == 12)
 330                                 tm->tm_hour = 0;
 331                         break;
 332
 333                 case 'j':       /* The day of year. */
 334                         LEGAL_ALT(0);
 335                         if (!(conv_num(&bp, &i, 1, 366)))
 336                                 return (0);
 337                         tm->tm_yday = i - 1;
 338                         break;
 339
 340                 case 'M':       /* The minute. */
 341                         LEGAL_ALT(ALT_O);
 342                         if (!(conv_num(&bp, &tm->tm_min, 0, 59)))
 343                                 return (0);
 344                         break;
 345
 346                 case 'm':       /* The month. */
 347                         LEGAL_ALT(ALT_O);
 348                         if (!(conv_num(&bp, &i, 1, 12)))
 349                                 return (0);
 350                         tm->tm_mon = i - 1;
 351                         break;
 352
 353                 case 'p':       /* The locale's equivalent of AM/PM. */
 354                         LEGAL_ALT(0);
 355                         /* AM? */
 356                         if (strcasecmp(am_pm[0], bp) == 0) {
 357                                 if (tm->tm_hour > 11)
 358                                         return (0);
 359
 360                                 bp += strlen(am_pm[0]);
 361                                 break;
 362                         }
 363                         /* PM? */
 364                         else if (strcasecmp(am_pm[1], bp) == 0) {
 365                                 if (tm->tm_hour > 11)
 366                                         return (0);
 367
 368                                 tm->tm_hour += 12;
 369                                 bp += strlen(am_pm[1]);
 370                                 break;
 371                         }
 372
 373                         /* Nothing matched. */
 374                         return (0);
 375
 376                 case 'S':       /* The seconds. */
 377                         LEGAL_ALT(ALT_O);
 378                         if (!(conv_num(&bp, &tm->tm_sec, 0, 61)))
 379                                 return (0);
 380                         break;
 381
 382                 case 'U':       /* The week of year, beginning on sunday. */
 383                 case 'W':       /* The week of year, beginning on monday. */
 384                         LEGAL_ALT(ALT_O);
 385                         /*
 386                          * XXX This is bogus, as we can not assume any valid
 387                          * information present in the tm structure at this
 388                          * point to calculate a real value, so just check the
 389                          * range for now.
 390                          */
 391                          if (!(conv_num(&bp, &i, 0, 53)))
 392                                 return (0);
 393                          break;
 394
 395                 case 'w':       /* The day of week, beginning on sunday. */
 396                         LEGAL_ALT(ALT_O);
 397                         if (!(conv_num(&bp, &tm->tm_wday, 0, 6)))
 398                                 return (0);
 399                         break;
 400
 401                 case 'Y':       /* The year. */
 402                         LEGAL_ALT(ALT_E);
 403                         if (!(conv_num(&bp, &i, 0, 9999)))
 404                                 return (0);
 405
 406                         tm->tm_year = i - TM_YEAR_BASE;
 407                         break;
 408
 409                 case 'y':       /* The year within 100 years of the epoch. */
 410                         LEGAL_ALT(ALT_E | ALT_O);
 411                         if (!(conv_num(&bp, &i, 0, 99)))
 412                                 return (0);
 413
 414                         if (split_year) {
 415                                 tm->tm_year = ((tm->tm_year / 100) * 100) + i;
 416                                 break;
 417                         }
 418                         split_year = 1;
 419                         if (i <= 68)
 420                                 tm->tm_year = i + 2000 - TM_YEAR_BASE;
 421                         else
 422                                 tm->tm_year = i + 1900 - TM_YEAR_BASE;
 423                         break;
 424
 425                 /*
 426                  * Miscellaneous conversions.
 427                  */
 428                 case 'n':       /* Any kind of white-space. */
 429                 case 't':
 430                         LEGAL_ALT(0);
 431                         while (isspace((unsigned char) *bp))
 432                                 bp++;
 433                         break;
 434
 435
 436                 default:        /* Unknown/unsupported conversion. */
 437                         return (0);
 438                 }
 439
 440
 441         }
 442
 443         /* LINTED functional specification */
 444         DE_CONST(bp, ret);
 445         return (ret);
 446 }