php-systzdata.patch

   1 # License: MIT
   2 # http://opensource.org/licenses/MIT
   3
   4 Add support for use of the system timezone database, rather
   5 than embedding a copy.  Discussed upstream but was not desired.
   6
   7 History:
   8 r19: adapt for timelib 2020.02 (in 8.0.0beta2)
   9 r18: adapt for autotool change in 7.3.3RC1
  10 r17: adapt for timelib 2018.01 (in 7.3.2RC1)
  11 r16: adapt for timelib 2017.06 (in 7.2.3RC1)
  12 r15: adapt for timelib 2017.05beta7 (in 7.2.0RC1)
  13 r14: improve check for valid tz file
  14 r13: adapt for upstream changes to use PHP allocator
  15 r12: adapt for upstream changes for new zic
  16 r11: use canonical names to avoid more case sensitivity issues
  17      round lat/long from zone.tab towards zero per builtin db
  18 r10: make timezone case insensitive
  19 r9: fix another compile error without --with-system-tzdata configured (Michael Heimpold)
  20 r8: fix compile error without --with-system-tzdata configured
  21 r7: improve check for valid timezone id to exclude directories
  22 r6: fix fd leak in r5, fix country code/BC flag use in
  23     timezone_identifiers_list() using system db,
  24     fix use of PECL timezonedb to override system db,
  25 r5: reverts addition of "System/Localtime" fake tzname.
  26     updated for 5.3.0, parses zone.tab to pick up mapping between
  27     timezone name, country code and long/lat coords
  28 r4: added "System/Localtime" tzname which uses /etc/localtime
  29 r3: fix a crash if /usr/share/zoneinfo doesn't exist (Raphael Geissert)
  30 r2: add filesystem trawl to set up name alias index
  31 r1: initial revision
  32
  33 diff -up php-8.0.0beta3/ext/date/config0.m4.systzdata php-8.0.0beta3/ext/date/config0.m4
  34 --- php-8.0.0beta3/ext/date/config0.m4.systzdata        2020-09-01 19:13:26.000000000 +0200
  35 +++ php-8.0.0beta3/ext/date/config0.m4  2020-09-02 08:07:51.039979873 +0200
  36 @@ -4,6 +4,19 @@ AC_CHECK_HEADERS([io.h])
  37  dnl Check for strtoll, atoll
  38  AC_CHECK_FUNCS(strtoll atoll)
  39
  40 +PHP_ARG_WITH(system-tzdata, for use of system timezone data,
  41 +[  --with-system-tzdata[=DIR]      to specify use of system timezone data],
  42 +no, no)
  43 +
  44 +if test "$PHP_SYSTEM_TZDATA" != "no"; then
  45 +   AC_DEFINE(HAVE_SYSTEM_TZDATA, 1, [Define if system timezone data is used])
  46 +
  47 +   if test "$PHP_SYSTEM_TZDATA" != "yes"; then
  48 +      AC_DEFINE_UNQUOTED(HAVE_SYSTEM_TZDATA_PREFIX, "$PHP_SYSTEM_TZDATA",
  49 +                         [Define for location of system timezone data])
  50 +   fi
  51 +fi
  52 +
  53  PHP_DATE_CFLAGS="-I@ext_builddir@/lib -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1 -DHAVE_TIMELIB_CONFIG_H=1"
  54  timelib_sources="lib/astro.c lib/dow.c lib/parse_date.c lib/parse_tz.c
  55                   lib/timelib.c lib/tm2unixtime.c lib/unixtime2tm.c lib/parse_iso_intervals.c lib/interval.c"
  56 diff -up php-8.0.0beta3/ext/date/lib/parse_tz.c.systzdata php-8.0.0beta3/ext/date/lib/parse_tz.c
  57 --- php-8.0.0beta3/ext/date/lib/parse_tz.c.systzdata    2020-09-01 19:13:26.000000000 +0200
  58 +++ php-8.0.0beta3/ext/date/lib/parse_tz.c      2020-09-02 08:07:51.039979873 +0200
  59 @@ -26,8 +26,21 @@
  60  #include "timelib.h"
  61  #include "timelib_private.h"
  62
  63 +#ifdef HAVE_SYSTEM_TZDATA
  64 +#include <sys/mman.h>
  65 +#include <sys/stat.h>
  66 +#include <limits.h>
  67 +#include <fcntl.h>
  68 +#include <unistd.h>
  69 +
  70 +#include "php_scandir.h"
  71 +
  72 +#else
  73  #define TIMELIB_SUPPORTS_V2DATA
  74  #include "timezonedb.h"
  75 +#endif
  76 +
  77 +#include <ctype.h>
  78
  79  #if (defined(__APPLE__) || defined(__APPLE_CC__)) && (defined(__BIG_ENDIAN__) || defined(__LITTLE_ENDIAN__))
  80  # if defined(__LITTLE_ENDIAN__)
  81 @@ -94,6 +107,11 @@ static int read_php_preamble(const unsig
  82  {
  83         uint32_t version;
  84
  85 +       if (memcmp(*tzf, "TZif", 4) == 0) {
  86 +               *tzf += 20;
  87 +               return 0;
  88 +       }
  89 +
  90         /* read ID */
  91         version = (*tzf)[3] - '0';
  92         *tzf += 4;
  93 @@ -418,7 +436,429 @@ void timelib_dump_tzinfo(timelib_tzinfo
  94         }
  95  }
  96
  97 -static int seek_to_tz_position(const unsigned char **tzf, const char *timezone, const timelib_tzdb *tzdb)
  98 +#ifdef HAVE_SYSTEM_TZDATA
  99 +
 100 +#ifdef HAVE_SYSTEM_TZDATA_PREFIX
 101 +#define ZONEINFO_PREFIX HAVE_SYSTEM_TZDATA_PREFIX
 102 +#else
 103 +#define ZONEINFO_PREFIX "/usr/share/zoneinfo"
 104 +#endif
 105 +
 106 +/* System timezone database pointer. */
 107 +static const timelib_tzdb *timezonedb_system;
 108 +
 109 +/* Hash table entry for the cache of the zone.tab mapping table. */
 110 +struct location_info {
 111 +        char code[2];
 112 +        double latitude, longitude;
 113 +        char name[64];
 114 +        char *comment;
 115 +        struct location_info *next;
 116 +};
 117 +
 118 +/* Cache of zone.tab. */
 119 +static struct location_info **system_location_table;
 120 +
 121 +/* Size of the zone.tab hash table; a random-ish prime big enough to
 122 + * prevent too many collisions. */
 123 +#define LOCINFO_HASH_SIZE (1021)
 124 +
 125 +/* Compute a case insensitive hash of str */
 126 +static uint32_t tz_hash(const char *str)
 127 +{
 128 +    const unsigned char *p = (const unsigned char *)str;
 129 +    uint32_t hash = 5381;
 130 +    int c;
 131 +
 132 +    while ((c = tolower(*p++)) != '\0') {
 133 +        hash = (hash << 5) ^ hash ^ c;
 134 +    }
 135 +
 136 +    return hash % LOCINFO_HASH_SIZE;
 137 +}
 138 +
 139 +/* Parse an ISO-6709 date as used in zone.tab. Returns end of the
 140 + * parsed string on success, or NULL on parse error.  On success,
 141 + * writes the parsed number to *result. */
 142 +static char *parse_iso6709(char *p, double *result)
 143 +{
 144 +    double v, sign;
 145 +    char *pend;
 146 +    size_t len;
 147 +
 148 +    if (*p == '+')
 149 +        sign = 1.0;
 150 +    else if (*p == '-')
 151 +        sign = -1.0;
 152 +    else
 153 +        return NULL;
 154 +
 155 +    p++;
 156 +    for (pend = p; *pend >= '0' && *pend <= '9'; pend++)
 157 +        ;;
 158 +
 159 +    /* Annoying encoding used by zone.tab has no decimal point, so use
 160 +     * the length to determine the format:
 161 +     *
 162 +     * 4 = DDMM
 163 +     * 5 = DDDMM
 164 +     * 6 = DDMMSS
 165 +     * 7 = DDDMMSS
 166 +     */
 167 +    len = pend - p;
 168 +    if (len < 4 || len > 7) {
 169 +        return NULL;
 170 +    }
 171 +
 172 +    /* p => [D]DD */
 173 +    v = (p[0] - '0') * 10.0 + (p[1] - '0');
 174 +    p += 2;
 175 +    if (len == 5 || len == 7)
 176 +        v = v * 10.0 + (*p++ - '0');
 177 +    /* p => MM[SS] */
 178 +    v += (10.0 * (p[0] - '0')
 179 +          + p[1] - '0') / 60.0;
 180 +    p += 2;
 181 +    /* p => [SS] */
 182 +    if (len > 5) {
 183 +        v += (10.0 * (p[0] - '0')
 184 +              + p[1] - '0') / 3600.0;
 185 +        p += 2;
 186 +    }
 187 +
 188 +    /* Round to five decimal place, not because it's a good idea,
 189 +     * but, because the builtin data uses rounded data, so, match
 190 +     * that. */
 191 +    *result = trunc(v * sign * 100000.0) / 100000.0;
 192 +
 193 +    return p;
 194 +}
 195 +
 196 +/* This function parses the zone.tab file to build up the mapping of
 197 + * timezone to country code and geographic location, and returns a
 198 + * hash table.  The hash table is indexed by the function:
 199 + *
 200 + *   tz_hash(timezone-name)
 201 + */
 202 +static struct location_info **create_location_table(void)
 203 +{
 204 +    struct location_info **li, *i;
 205 +    char zone_tab[PATH_MAX];
 206 +    char line[512];
 207 +    FILE *fp;
 208 +
 209 +    strncpy(zone_tab, ZONEINFO_PREFIX "/zone.tab", sizeof zone_tab);
 210 +
 211 +    fp = fopen(zone_tab, "r");
 212 +    if (!fp) {
 213 +        return NULL;
 214 +    }
 215 +
 216 +    li = calloc(LOCINFO_HASH_SIZE, sizeof *li);
 217 +
 218 +    while (fgets(line, sizeof line, fp)) {
 219 +        char *p = line, *code, *name, *comment;
 220 +        uint32_t hash;
 221 +        double latitude, longitude;
 222 +
 223 +        while (isspace(*p))
 224 +            p++;
 225 +
 226 +        if (*p == '#' || *p == '\0' || *p == '\n')
 227 +            continue;
 228 +
 229 +        if (!isalpha(p[0]) || !isalpha(p[1]) || p[2] != '\t')
 230 +            continue;
 231 +
 232 +        /* code => AA */
 233 +        code = p;
 234 +        p[2] = 0;
 235 +        p += 3;
 236 +
 237 +        /* coords => [+-][D]DDMM[SS][+-][D]DDMM[SS] */
 238 +        p = parse_iso6709(p, &latitude);
 239 +        if (!p) {
 240 +            continue;
 241 +        }
 242 +        p = parse_iso6709(p, &longitude);
 243 +        if (!p) {
 244 +            continue;
 245 +        }
 246 +
 247 +        if (!p || *p != '\t') {
 248 +            continue;
 249 +        }
 250 +
 251 +        /* name = string */
 252 +        name = ++p;
 253 +        while (*p != '\t' && *p && *p != '\n')
 254 +            p++;
 255 +
 256 +        *p++ = '\0';
 257 +
 258 +        /* comment = string */
 259 +        comment = p;
 260 +        while (*p != '\t' && *p && *p != '\n')
 261 +            p++;
 262 +
 263 +        if (*p == '\n' || *p == '\t')
 264 +            *p = '\0';
 265 +
 266 +        hash = tz_hash(name);
 267 +        i = malloc(sizeof *i);
 268 +        memcpy(i->code, code, 2);
 269 +        strncpy(i->name, name, sizeof i->name);
 270 +        i->comment = strdup(comment);
 271 +        i->longitude = longitude;
 272 +        i->latitude = latitude;
 273 +        i->next = li[hash];
 274 +        li[hash] = i;
 275 +        /* printf("%s [%u, %f, %f]\n", name, hash, latitude, longitude); */
 276 +    }
 277 +
 278 +    fclose(fp);
 279 +
 280 +    return li;
 281 +}
 282 +
 283 +/* Return location info from hash table, using given timezone name.
 284 + * Returns NULL if the name could not be found. */
 285 +const struct location_info *find_zone_info(struct location_info **li,
 286 +                                           const char *name)
 287 +{
 288 +    uint32_t hash = tz_hash(name);
 289 +    const struct location_info *l;
 290 +
 291 +    if (!li) {
 292 +        return NULL;
 293 +    }
 294 +
 295 +    for (l = li[hash]; l; l = l->next) {
 296 +        if (timelib_strcasecmp(l->name, name) == 0)
 297 +            return l;
 298 +    }
 299 +
 300 +    return NULL;
 301 +}
 302 +
 303 +/* Filter out some non-tzdata files and the posix/right databases, if
 304 + * present. */
 305 +static int index_filter(const struct dirent *ent)
 306 +{
 307 +       return strcmp(ent->d_name, ".") != 0
 308 +               && strcmp(ent->d_name, "..") != 0
 309 +               && strcmp(ent->d_name, "posix") != 0
 310 +               && strcmp(ent->d_name, "posixrules") != 0
 311 +               && strcmp(ent->d_name, "right") != 0
 312 +               && strstr(ent->d_name, ".list") == NULL
 313 +               && strstr(ent->d_name, ".tab") == NULL;
 314 +}
 315 +
 316 +static int sysdbcmp(const void *first, const void *second)
 317 +{
 318 +        const timelib_tzdb_index_entry *alpha = first, *beta = second;
 319 +
 320 +        return timelib_strcasecmp(alpha->id, beta->id);
 321 +}
 322 +
 323 +
 324 +/* Create the zone identifier index by trawling the filesystem. */
 325 +static void create_zone_index(timelib_tzdb *db)
 326 +{
 327 +       size_t dirstack_size,  dirstack_top;
 328 +       size_t index_size, index_next;
 329 +       timelib_tzdb_index_entry *db_index;
 330 +       char **dirstack;
 331 +
 332 +       /* LIFO stack to hold directory entries to scan; each slot is a
 333 +        * directory name relative to the zoneinfo prefix. */
 334 +       dirstack_size = 32;
 335 +       dirstack = malloc(dirstack_size * sizeof *dirstack);
 336 +       dirstack_top = 1;
 337 +       dirstack[0] = strdup("");
 338 +
 339 +       /* Index array. */
 340 +       index_size = 64;
 341 +       db_index = malloc(index_size * sizeof *db_index);
 342 +       index_next = 0;
 343 +
 344 +       do {
 345 +               struct dirent **ents;
 346 +               char name[PATH_MAX], *top;
 347 +               int count;
 348 +
 349 +               /* Pop the top stack entry, and iterate through its contents. */
 350 +               top = dirstack[--dirstack_top];
 351 +               snprintf(name, sizeof name, ZONEINFO_PREFIX "/%s", top);
 352 +
 353 +               count = php_scandir(name, &ents, index_filter, php_alphasort);
 354 +
 355 +               while (count > 0) {
 356 +                       struct stat st;
 357 +                       const char *leaf = ents[count - 1]->d_name;
 358 +
 359 +                       snprintf(name, sizeof name, ZONEINFO_PREFIX "/%s/%s",
 360 +                                top, leaf);
 361 +
 362 +                       if (strlen(name) && stat(name, &st) == 0) {
 363 +                               /* Name, relative to the zoneinfo prefix. */
 364 +                               const char *root = top;
 365 +
 366 +                               if (root[0] == '/') root++;
 367 +
 368 +                               snprintf(name, sizeof name, "%s%s%s", root,
 369 +                                        *root ? "/": "", leaf);
 370 +
 371 +                               if (S_ISDIR(st.st_mode)) {
 372 +                                       if (dirstack_top == dirstack_size) {
 373 +                                               dirstack_size *= 2;
 374 +                                               dirstack = realloc(dirstack,
 375 +                                                                  dirstack_size * sizeof *dirstack);
 376 +                                       }
 377 +                                       dirstack[dirstack_top++] = strdup(name);
 378 +                               }
 379 +                               else {
 380 +                                       if (index_next == index_size) {
 381 +                                               index_size *= 2;
 382 +                                               db_index = realloc(db_index,
 383 +                                                                  index_size * sizeof *db_index);
 384 +                                       }
 385 +
 386 +                                       db_index[index_next++].id = strdup(name);
 387 +                               }
 388 +                       }
 389 +
 390 +                       free(ents[--count]);
 391 +               }
 392 +
 393 +               if (count != -1) free(ents);
 394 +               free(top);
 395 +       } while (dirstack_top);
 396 +
 397 +        qsort(db_index, index_next, sizeof *db_index, sysdbcmp);
 398 +
 399 +       db->index = db_index;
 400 +       db->index_size = index_next;
 401 +
 402 +       free(dirstack);
 403 +}
 404 +
 405 +#define FAKE_HEADER "1234\0??\1??"
 406 +#define FAKE_UTC_POS (7 - 4)
 407 +
 408 +/* Create a fake data segment for database 'sysdb'. */
 409 +static void fake_data_segment(timelib_tzdb *sysdb,
 410 +                              struct location_info **info)
 411 +{
 412 +        size_t n;
 413 +        char *data, *p;
 414 +
 415 +        data = malloc(3 * sysdb->index_size + 7);
 416 +
 417 +        p = mempcpy(data, FAKE_HEADER, sizeof(FAKE_HEADER) - 1);
 418 +
 419 +        for (n = 0; n < sysdb->index_size; n++) {
 420 +                const struct location_info *li;
 421 +                timelib_tzdb_index_entry *ent;
 422 +
 423 +                ent = (timelib_tzdb_index_entry *)&sysdb->index[n];
 424 +
 425 +                /* Lookup the timezone name in the hash table. */
 426 +                if (strcmp(ent->id, "UTC") == 0) {
 427 +                        ent->pos = FAKE_UTC_POS;
 428 +                        continue;
 429 +                }
 430 +
 431 +                li = find_zone_info(info, ent->id);
 432 +                if (li) {
 433 +                        /* If found, append the BC byte and the
 434 +                         * country code; set the position for this
 435 +                         * section of timezone data.  */
 436 +                        ent->pos = (p - data) - 4;
 437 +                        *p++ = '\1';
 438 +                        *p++ = li->code[0];
 439 +                        *p++ = li->code[1];
 440 +                }
 441 +                else {
 442 +                        /* If not found, the timezone data can
 443 +                         * point at the header. */
 444 +                        ent->pos = 0;
 445 +                }
 446 +        }
 447 +
 448 +        sysdb->data = (unsigned char *)data;
 449 +}
 450 +
 451 +/* Returns true if the passed-in stat structure describes a
 452 + * probably-valid timezone file. */
 453 +static int is_valid_tzfile(const struct stat *st, int fd)
 454 +{
 455 +       if (fd) {
 456 +               char buf[20];
 457 +               if (read(fd, buf, 20)!=20) {
 458 +                       return 0;
 459 +               }
 460 +               lseek(fd, SEEK_SET, 0);
 461 +               if (memcmp(buf, "TZif", 4)) {
 462 +                       return 0;
 463 +               }
 464 +       }
 465 +       return S_ISREG(st->st_mode) && st->st_size > 20;
 466 +}
 467 +
 468 +/* To allow timezone names to be used case-insensitively, find the
 469 + * canonical name for this timezone, if possible. */
 470 +static const char *canonical_tzname(const char *timezone)
 471 +{
 472 +    if (timezonedb_system) {
 473 +        timelib_tzdb_index_entry *ent, lookup;
 474 +
 475 +        lookup.id = (char *)timezone;
 476 +
 477 +        ent = bsearch(&lookup, timezonedb_system->index,
 478 +                      timezonedb_system->index_size, sizeof lookup,
 479 +                      sysdbcmp);
 480 +        if (ent) {
 481 +            return ent->id;
 482 +        }
 483 +    }
 484 +
 485 +    return timezone;
 486 +}
 487 +
 488 +/* Return the mmap()ed tzfile if found, else NULL.  On success, the
 489 + * length of the mapped data is placed in *length. */
 490 +static char *map_tzfile(const char *timezone, size_t *length)
 491 +{
 492 +       char fname[PATH_MAX];
 493 +       struct stat st;
 494 +       char *p;
 495 +       int fd;
 496 +
 497 +       if (timezone[0] == '\0' || strstr(timezone, "..") != NULL) {
 498 +               return NULL;
 499 +       }
 500 +
 501 +       snprintf(fname, sizeof fname, ZONEINFO_PREFIX "/%s", canonical_tzname(timezone));
 502 +
 503 +       fd = open(fname, O_RDONLY);
 504 +       if (fd == -1) {
 505 +               return NULL;
 506 +       } else if (fstat(fd, &st) != 0 || !is_valid_tzfile(&st, fd)) {
 507 +               close(fd);
 508 +               return NULL;
 509 +       }
 510 +
 511 +       *length = st.st_size;
 512 +       p = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
 513 +       close(fd);
 514 +
 515 +       return p != MAP_FAILED ? p : NULL;
 516 +}
 517 +
 518 +#endif
 519 +
 520 +static int inmem_seek_to_tz_position(const unsigned char **tzf, const char *timezone, const timelib_tzdb *tzdb)
 521  {
 522         int left = 0, right = tzdb->index_size - 1;
 523
 524 @@ -444,9 +884,48 @@ static int seek_to_tz_position(const uns
 525         return 0;
 526  }
 527
 528 +static int seek_to_tz_position(const unsigned char **tzf, const char *timezone,
 529 +                              char **map, size_t *maplen,
 530 +                              const timelib_tzdb *tzdb)
 531 +{
 532 +#ifdef HAVE_SYSTEM_TZDATA
 533 +       if (tzdb == timezonedb_system) {
 534 +               char *orig;
 535 +
 536 +               orig = map_tzfile(timezone, maplen);
 537 +               if (orig == NULL) {
 538 +                       return 0;
 539 +               }
 540 +
 541 +               (*tzf) = (unsigned char *)orig;
 542 +               *map = orig;
 543 +        return 1;
 544 +       }
 545 +       else
 546 +#endif
 547 +       {
 548 +               return inmem_seek_to_tz_position(tzf, timezone, tzdb);
 549 +       }
 550 +}
 551 +
 552  const timelib_tzdb *timelib_builtin_db(void)
 553  {
 554 +#ifdef HAVE_SYSTEM_TZDATA
 555 +       if (timezonedb_system == NULL) {
 556 +               timelib_tzdb *tmp = malloc(sizeof *tmp);
 557 +
 558 +               tmp->version = "0.system";
 559 +               tmp->data = NULL;
 560 +               create_zone_index(tmp);
 561 +               system_location_table = create_location_table();
 562 +               fake_data_segment(tmp, system_location_table);
 563 +               timezonedb_system = tmp;
 564 +       }
 565 +
 566 +       return timezonedb_system;
 567 +#else
 568         return &timezonedb_builtin;
 569 +#endif
 570  }
 571
 572  const timelib_tzdb_index_entry *timelib_timezone_identifiers_list(const timelib_tzdb *tzdb, int *count)
 573 @@ -458,7 +937,30 @@ const timelib_tzdb_index_entry *timelib_
 574  int timelib_timezone_id_is_valid(const char *timezone, const timelib_tzdb *tzdb)
 575  {
 576         const unsigned char *tzf;
 577 -       return (seek_to_tz_position(&tzf, timezone, tzdb));
 578 +
 579 +#ifdef HAVE_SYSTEM_TZDATA
 580 +       if (tzdb == timezonedb_system) {
 581 +               char fname[PATH_MAX];
 582 +               struct stat st;
 583 +
 584 +               if (timezone[0] == '\0' || strstr(timezone, "..") != NULL) {
 585 +                       return 0;
 586 +               }
 587 +
 588 +               if (system_location_table) {
 589 +                       if (find_zone_info(system_location_table, timezone) != NULL) {
 590 +                               /* found in cache */
 591 +                               return 1;
 592 +                       }
 593 +               }
 594 +
 595 +               snprintf(fname, sizeof fname, ZONEINFO_PREFIX "/%s", canonical_tzname(timezone));
 596 +
 597 +               return stat(fname, &st) == 0 && is_valid_tzfile(&st, 0);
 598 +       }
 599 +#endif
 600 +
 601 +       return (inmem_seek_to_tz_position(&tzf, timezone, tzdb));
 602  }
 603
 604  static int skip_64bit_preamble(const unsigned char **tzf, timelib_tzinfo *tz)
 605 @@ -500,12 +1002,14 @@ static timelib_tzinfo* timelib_tzinfo_ct
 606  timelib_tzinfo *timelib_parse_tzfile(const char *timezone, const timelib_tzdb *tzdb, int *error_code)
 607  {
 608         const unsigned char *tzf;
 609 +       char *memmap = NULL;
 610 +       size_t maplen;
 611         timelib_tzinfo *tmp;
 612         int version;
 613         int transitions_result, types_result;
 614         unsigned int type; /* TIMELIB_TZINFO_PHP or TIMELIB_TZINFO_ZONEINFO */
 615
 616 -       if (seek_to_tz_position(&tzf, timezone, tzdb)) {
 617 +       if (seek_to_tz_position(&tzf, timezone, &memmap, &maplen, tzdb)) {
 618                 tmp = timelib_tzinfo_ctor(timezone);
 619
 620                 version = read_preamble(&tzf, tmp, &type);
 621 @@ -540,11 +1044,36 @@ timelib_tzinfo *timelib_parse_tzfile(con
 622                 }
 623                 skip_posix_string(&tzf, tmp);
 624
 625 +#ifdef HAVE_SYSTEM_TZDATA
 626 +               if (memmap) {
 627 +                       const struct location_info *li;
 628 +
 629 +                       /* TZif-style - grok the location info from the system database,
 630 +                        * if possible. */
 631 +
 632 +                       if ((li = find_zone_info(system_location_table, timezone)) != NULL) {
 633 +                               tmp->location.comments = timelib_strdup(li->comment);
 634 +                               strncpy(tmp->location.country_code, li->code, 2);
 635 +                               tmp->location.longitude = li->longitude;
 636 +                               tmp->location.latitude = li->latitude;
 637 +                               tmp->bc = 1;
 638 +                       }
 639 +                       else {
 640 +                               set_default_location_and_comments(&tzf, tmp);
 641 +                       }
 642 +
 643 +                       /* Now done with the mmap segment - discard it. */
 644 +                       munmap(memmap, maplen);
 645 +               } else {
 646 +#endif
 647                 if (type == TIMELIB_TZINFO_PHP) {
 648                         read_location(&tzf, tmp);
 649                 } else {
 650                         set_default_location_and_comments(&tzf, tmp);
 651                 }
 652 +#ifdef HAVE_SYSTEM_TZDATA
 653 +               }
 654 +#endif
 655         } else {
 656                 *error_code = TIMELIB_ERROR_NO_SUCH_TIMEZONE;
 657                 tmp = NULL;