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 r17: adapt for autotool change in 7.2.16RC1
   9 r16: adapt for timelib 2017.06 (in 7.2.3RC1)
  10 r15: adapt for timelib 2017.05beta7 (in 7.2.0RC1)
  11 r14: improve check for valid tz file
  12 r13: adapt for upstream changes to use PHP allocator
  13 r12: adapt for upstream changes for new zic
  14 r11: use canonical names to avoid more case sensitivity issues
  15      round lat/long from zone.tab towards zero per builtin db
  16 r10: make timezone case insensitive
  17 r9: fix another compile error without --with-system-tzdata configured (Michael Heimpold)
  18 r8: fix compile error without --with-system-tzdata configured
  19 r7: improve check for valid timezone id to exclude directories
  20 r6: fix fd leak in r5, fix country code/BC flag use in
  21     timezone_identifiers_list() using system db,
  22     fix use of PECL timezonedb to override system db,
  23 r5: reverts addition of "System/Localtime" fake tzname.
  24     updated for 5.3.0, parses zone.tab to pick up mapping between
  25     timezone name, country code and long/lat coords
  26 r4: added "System/Localtime" tzname which uses /etc/localtime
  27 r3: fix a crash if /usr/share/zoneinfo doesn't exist (Raphael Geissert)
  28 r2: add filesystem trawl to set up name alias index
  29 r1: initial revision
  30
  31 diff -up php-7.2.16RC1/ext/date/config0.m4.systzdata php-7.2.16RC1/ext/date/config0.m4
  32 --- php-7.2.16RC1/ext/date/config0.m4.systzdata 2019-02-19 11:22:22.223741585 +0100
  33 +++ php-7.2.16RC1/ext/date/config0.m4   2019-02-19 11:23:05.089111556 +0100
  34 @@ -10,6 +10,19 @@ io.h
  35  dnl Check for strtoll, atoll
  36  AC_CHECK_FUNCS(strtoll atoll)
  37
  38 +PHP_ARG_WITH(system-tzdata, for use of system timezone data,
  39 +[  --with-system-tzdata[=DIR]      to specify use of system timezone data],
  40 +no, no)
  41 +
  42 +if test "$PHP_SYSTEM_TZDATA" != "no"; then
  43 +   AC_DEFINE(HAVE_SYSTEM_TZDATA, 1, [Define if system timezone data is used])
  44 +
  45 +   if test "$PHP_SYSTEM_TZDATA" != "yes"; then
  46 +      AC_DEFINE_UNQUOTED(HAVE_SYSTEM_TZDATA_PREFIX, "$PHP_SYSTEM_TZDATA",
  47 +                         [Define for location of system timezone data])
  48 +   fi
  49 +fi
  50 +
  51  PHP_DATE_CFLAGS="-I@ext_builddir@/lib -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1 -DHAVE_TIMELIB_CONFIG_H=1"
  52  timelib_sources="lib/astro.c lib/dow.c lib/parse_date.c lib/parse_tz.c
  53                   lib/timelib.c lib/tm2unixtime.c lib/unixtime2tm.c lib/parse_iso_intervals.c lib/interval.c"
  54 diff -up php-7.2.16RC1/ext/date/lib/parse_tz.c.systzdata php-7.2.16RC1/ext/date/lib/parse_tz.c
  55 --- php-7.2.16RC1/ext/date/lib/parse_tz.c.systzdata     2019-02-19 11:13:22.000000000 +0100
  56 +++ php-7.2.16RC1/ext/date/lib/parse_tz.c       2019-02-19 11:19:40.245313535 +0100
  57 @@ -25,8 +25,21 @@
  58  #include "timelib.h"
  59  #include "timelib_private.h"
  60
  61 +#ifdef HAVE_SYSTEM_TZDATA
  62 +#include <sys/mman.h>
  63 +#include <sys/stat.h>
  64 +#include <limits.h>
  65 +#include <fcntl.h>
  66 +#include <unistd.h>
  67 +
  68 +#include "php_scandir.h"
  69 +
  70 +#else
  71  #define TIMELIB_SUPPORTS_V2DATA
  72  #include "timezonedb.h"
  73 +#endif
  74 +
  75 +#include <ctype.h>
  76
  77  #if (defined(__APPLE__) || defined(__APPLE_CC__)) && (defined(__BIG_ENDIAN__) || defined(__LITTLE_ENDIAN__))
  78  # if defined(__LITTLE_ENDIAN__)
  79 @@ -67,6 +80,11 @@ static int read_php_preamble(const unsig
  80  {
  81         uint32_t version;
  82
  83 +       if (memcmp(*tzf, "TZif", 4) == 0) {
  84 +               *tzf += 20;
  85 +               return 0;
  86 +       }
  87 +
  88         /* read ID */
  89         version = (*tzf)[3] - '0';
  90         *tzf += 4;
  91 @@ -374,7 +392,429 @@ void timelib_dump_tzinfo(timelib_tzinfo
  92         }
  93  }
  94
  95 -static int seek_to_tz_position(const unsigned char **tzf, char *timezone, const timelib_tzdb *tzdb)
  96 +#ifdef HAVE_SYSTEM_TZDATA
  97 +
  98 +#ifdef HAVE_SYSTEM_TZDATA_PREFIX
  99 +#define ZONEINFO_PREFIX HAVE_SYSTEM_TZDATA_PREFIX
 100 +#else
 101 +#define ZONEINFO_PREFIX "/usr/share/zoneinfo"
 102 +#endif
 103 +
 104 +/* System timezone database pointer. */
 105 +static const timelib_tzdb *timezonedb_system;
 106 +
 107 +/* Hash table entry for the cache of the zone.tab mapping table. */
 108 +struct location_info {
 109 +        char code[2];
 110 +        double latitude, longitude;
 111 +        char name[64];
 112 +        char *comment;
 113 +        struct location_info *next;
 114 +};
 115 +
 116 +/* Cache of zone.tab. */
 117 +static struct location_info **system_location_table;
 118 +
 119 +/* Size of the zone.tab hash table; a random-ish prime big enough to
 120 + * prevent too many collisions. */
 121 +#define LOCINFO_HASH_SIZE (1021)
 122 +
 123 +/* Compute a case insensitive hash of str */
 124 +static uint32_t tz_hash(const char *str)
 125 +{
 126 +    const unsigned char *p = (const unsigned char *)str;
 127 +    uint32_t hash = 5381;
 128 +    int c;
 129 +
 130 +    while ((c = tolower(*p++)) != '\0') {
 131 +        hash = (hash << 5) ^ hash ^ c;
 132 +    }
 133 +
 134 +    return hash % LOCINFO_HASH_SIZE;
 135 +}
 136 +
 137 +/* Parse an ISO-6709 date as used in zone.tab. Returns end of the
 138 + * parsed string on success, or NULL on parse error.  On success,
 139 + * writes the parsed number to *result. */
 140 +static char *parse_iso6709(char *p, double *result)
 141 +{
 142 +    double v, sign;
 143 +    char *pend;
 144 +    size_t len;
 145 +
 146 +    if (*p == '+')
 147 +        sign = 1.0;
 148 +    else if (*p == '-')
 149 +        sign = -1.0;
 150 +    else
 151 +        return NULL;
 152 +
 153 +    p++;
 154 +    for (pend = p; *pend >= '0' && *pend <= '9'; pend++)
 155 +        ;;
 156 +
 157 +    /* Annoying encoding used by zone.tab has no decimal point, so use
 158 +     * the length to determine the format:
 159 +     *
 160 +     * 4 = DDMM
 161 +     * 5 = DDDMM
 162 +     * 6 = DDMMSS
 163 +     * 7 = DDDMMSS
 164 +     */
 165 +    len = pend - p;
 166 +    if (len < 4 || len > 7) {
 167 +        return NULL;
 168 +    }
 169 +
 170 +    /* p => [D]DD */
 171 +    v = (p[0] - '0') * 10.0 + (p[1] - '0');
 172 +    p += 2;
 173 +    if (len == 5 || len == 7)
 174 +        v = v * 10.0 + (*p++ - '0');
 175 +    /* p => MM[SS] */
 176 +    v += (10.0 * (p[0] - '0')
 177 +          + p[1] - '0') / 60.0;
 178 +    p += 2;
 179 +    /* p => [SS] */
 180 +    if (len > 5) {
 181 +        v += (10.0 * (p[0] - '0')
 182 +              + p[1] - '0') / 3600.0;
 183 +        p += 2;
 184 +    }
 185 +
 186 +    /* Round to five decimal place, not because it's a good idea,
 187 +     * but, because the builtin data uses rounded data, so, match
 188 +     * that. */
 189 +    *result = trunc(v * sign * 100000.0) / 100000.0;
 190 +
 191 +    return p;
 192 +}
 193 +
 194 +/* This function parses the zone.tab file to build up the mapping of
 195 + * timezone to country code and geographic location, and returns a
 196 + * hash table.  The hash table is indexed by the function:
 197 + *
 198 + *   tz_hash(timezone-name)
 199 + */
 200 +static struct location_info **create_location_table(void)
 201 +{
 202 +    struct location_info **li, *i;
 203 +    char zone_tab[PATH_MAX];
 204 +    char line[512];
 205 +    FILE *fp;
 206 +
 207 +    strncpy(zone_tab, ZONEINFO_PREFIX "/zone.tab", sizeof zone_tab);
 208 +
 209 +    fp = fopen(zone_tab, "r");
 210 +    if (!fp) {
 211 +        return NULL;
 212 +    }
 213 +
 214 +    li = calloc(LOCINFO_HASH_SIZE, sizeof *li);
 215 +
 216 +    while (fgets(line, sizeof line, fp)) {
 217 +        char *p = line, *code, *name, *comment;
 218 +        uint32_t hash;
 219 +        double latitude, longitude;
 220 +
 221 +        while (isspace(*p))
 222 +            p++;
 223 +
 224 +        if (*p == '#' || *p == '\0' || *p == '\n')
 225 +            continue;
 226 +
 227 +        if (!isalpha(p[0]) || !isalpha(p[1]) || p[2] != '\t')
 228 +            continue;
 229 +
 230 +        /* code => AA */
 231 +        code = p;
 232 +        p[2] = 0;
 233 +        p += 3;
 234 +
 235 +        /* coords => [+-][D]DDMM[SS][+-][D]DDMM[SS] */
 236 +        p = parse_iso6709(p, &latitude);
 237 +        if (!p) {
 238 +            continue;
 239 +        }
 240 +        p = parse_iso6709(p, &longitude);
 241 +        if (!p) {
 242 +            continue;
 243 +        }
 244 +
 245 +        if (!p || *p != '\t') {
 246 +            continue;
 247 +        }
 248 +
 249 +        /* name = string */
 250 +        name = ++p;
 251 +        while (*p != '\t' && *p && *p != '\n')
 252 +            p++;
 253 +
 254 +        *p++ = '\0';
 255 +
 256 +        /* comment = string */
 257 +        comment = p;
 258 +        while (*p != '\t' && *p && *p != '\n')
 259 +            p++;
 260 +
 261 +        if (*p == '\n' || *p == '\t')
 262 +            *p = '\0';
 263 +
 264 +        hash = tz_hash(name);
 265 +        i = malloc(sizeof *i);
 266 +        memcpy(i->code, code, 2);
 267 +        strncpy(i->name, name, sizeof i->name);
 268 +        i->comment = strdup(comment);
 269 +        i->longitude = longitude;
 270 +        i->latitude = latitude;
 271 +        i->next = li[hash];
 272 +        li[hash] = i;
 273 +        /* printf("%s [%u, %f, %f]\n", name, hash, latitude, longitude); */
 274 +    }
 275 +
 276 +    fclose(fp);
 277 +
 278 +    return li;
 279 +}
 280 +
 281 +/* Return location info from hash table, using given timezone name.
 282 + * Returns NULL if the name could not be found. */
 283 +const struct location_info *find_zone_info(struct location_info **li,
 284 +                                           const char *name)
 285 +{
 286 +    uint32_t hash = tz_hash(name);
 287 +    const struct location_info *l;
 288 +
 289 +    if (!li) {
 290 +        return NULL;
 291 +    }
 292 +
 293 +    for (l = li[hash]; l; l = l->next) {
 294 +        if (timelib_strcasecmp(l->name, name) == 0)
 295 +            return l;
 296 +    }
 297 +
 298 +    return NULL;
 299 +}
 300 +
 301 +/* Filter out some non-tzdata files and the posix/right databases, if
 302 + * present. */
 303 +static int index_filter(const struct dirent *ent)
 304 +{
 305 +       return strcmp(ent->d_name, ".") != 0
 306 +               && strcmp(ent->d_name, "..") != 0
 307 +               && strcmp(ent->d_name, "posix") != 0
 308 +               && strcmp(ent->d_name, "posixrules") != 0
 309 +               && strcmp(ent->d_name, "right") != 0
 310 +               && strstr(ent->d_name, ".list") == NULL
 311 +               && strstr(ent->d_name, ".tab") == NULL;
 312 +}
 313 +
 314 +static int sysdbcmp(const void *first, const void *second)
 315 +{
 316 +        const timelib_tzdb_index_entry *alpha = first, *beta = second;
 317 +
 318 +        return timelib_strcasecmp(alpha->id, beta->id);
 319 +}
 320 +
 321 +
 322 +/* Create the zone identifier index by trawling the filesystem. */
 323 +static void create_zone_index(timelib_tzdb *db)
 324 +{
 325 +       size_t dirstack_size,  dirstack_top;
 326 +       size_t index_size, index_next;
 327 +       timelib_tzdb_index_entry *db_index;
 328 +       char **dirstack;
 329 +
 330 +       /* LIFO stack to hold directory entries to scan; each slot is a
 331 +        * directory name relative to the zoneinfo prefix. */
 332 +       dirstack_size = 32;
 333 +       dirstack = malloc(dirstack_size * sizeof *dirstack);
 334 +       dirstack_top = 1;
 335 +       dirstack[0] = strdup("");
 336 +
 337 +       /* Index array. */
 338 +       index_size = 64;
 339 +       db_index = malloc(index_size * sizeof *db_index);
 340 +       index_next = 0;
 341 +
 342 +       do {
 343 +               struct dirent **ents;
 344 +               char name[PATH_MAX], *top;
 345 +               int count;
 346 +
 347 +               /* Pop the top stack entry, and iterate through its contents. */
 348 +               top = dirstack[--dirstack_top];
 349 +               snprintf(name, sizeof name, ZONEINFO_PREFIX "/%s", top);
 350 +
 351 +               count = php_scandir(name, &ents, index_filter, php_alphasort);
 352 +
 353 +               while (count > 0) {
 354 +                       struct stat st;
 355 +                       const char *leaf = ents[count - 1]->d_name;
 356 +
 357 +                       snprintf(name, sizeof name, ZONEINFO_PREFIX "/%s/%s",
 358 +                                top, leaf);
 359 +
 360 +                       if (strlen(name) && stat(name, &st) == 0) {
 361 +                               /* Name, relative to the zoneinfo prefix. */
 362 +                               const char *root = top;
 363 +
 364 +                               if (root[0] == '/') root++;
 365 +
 366 +                               snprintf(name, sizeof name, "%s%s%s", root,
 367 +                                        *root ? "/": "", leaf);
 368 +
 369 +                               if (S_ISDIR(st.st_mode)) {
 370 +                                       if (dirstack_top == dirstack_size) {
 371 +                                               dirstack_size *= 2;
 372 +                                               dirstack = realloc(dirstack,
 373 +                                                                  dirstack_size * sizeof *dirstack);
 374 +                                       }
 375 +                                       dirstack[dirstack_top++] = strdup(name);
 376 +                               }
 377 +                               else {
 378 +                                       if (index_next == index_size) {
 379 +                                               index_size *= 2;
 380 +                                               db_index = realloc(db_index,
 381 +                                                                  index_size * sizeof *db_index);
 382 +                                       }
 383 +
 384 +                                       db_index[index_next++].id = strdup(name);
 385 +                               }
 386 +                       }
 387 +
 388 +                       free(ents[--count]);
 389 +               }
 390 +
 391 +               if (count != -1) free(ents);
 392 +               free(top);
 393 +       } while (dirstack_top);
 394 +
 395 +        qsort(db_index, index_next, sizeof *db_index, sysdbcmp);
 396 +
 397 +       db->index = db_index;
 398 +       db->index_size = index_next;
 399 +
 400 +       free(dirstack);
 401 +}
 402 +
 403 +#define FAKE_HEADER "1234\0??\1??"
 404 +#define FAKE_UTC_POS (7 - 4)
 405 +
 406 +/* Create a fake data segment for database 'sysdb'. */
 407 +static void fake_data_segment(timelib_tzdb *sysdb,
 408 +                              struct location_info **info)
 409 +{
 410 +        size_t n;
 411 +        char *data, *p;
 412 +
 413 +        data = malloc(3 * sysdb->index_size + 7);
 414 +
 415 +        p = mempcpy(data, FAKE_HEADER, sizeof(FAKE_HEADER) - 1);
 416 +
 417 +        for (n = 0; n < sysdb->index_size; n++) {
 418 +                const struct location_info *li;
 419 +                timelib_tzdb_index_entry *ent;
 420 +
 421 +                ent = (timelib_tzdb_index_entry *)&sysdb->index[n];
 422 +
 423 +                /* Lookup the timezone name in the hash table. */
 424 +                if (strcmp(ent->id, "UTC") == 0) {
 425 +                        ent->pos = FAKE_UTC_POS;
 426 +                        continue;
 427 +                }
 428 +
 429 +                li = find_zone_info(info, ent->id);
 430 +                if (li) {
 431 +                        /* If found, append the BC byte and the
 432 +                         * country code; set the position for this
 433 +                         * section of timezone data.  */
 434 +                        ent->pos = (p - data) - 4;
 435 +                        *p++ = '\1';
 436 +                        *p++ = li->code[0];
 437 +                        *p++ = li->code[1];
 438 +                }
 439 +                else {
 440 +                        /* If not found, the timezone data can
 441 +                         * point at the header. */
 442 +                        ent->pos = 0;
 443 +                }
 444 +        }
 445 +
 446 +        sysdb->data = (unsigned char *)data;
 447 +}
 448 +
 449 +/* Returns true if the passed-in stat structure describes a
 450 + * probably-valid timezone file. */
 451 +static int is_valid_tzfile(const struct stat *st, int fd)
 452 +{
 453 +       if (fd) {
 454 +               char buf[20];
 455 +               if (read(fd, buf, 20)!=20) {
 456 +                       return 0;
 457 +               }
 458 +               lseek(fd, SEEK_SET, 0);
 459 +               if (memcmp(buf, "TZif", 4)) {
 460 +                       return 0;
 461 +               }
 462 +       }
 463 +       return S_ISREG(st->st_mode) && st->st_size > 20;
 464 +}
 465 +
 466 +/* To allow timezone names to be used case-insensitively, find the
 467 + * canonical name for this timezone, if possible. */
 468 +static const char *canonical_tzname(const char *timezone)
 469 +{
 470 +    if (timezonedb_system) {
 471 +        timelib_tzdb_index_entry *ent, lookup;
 472 +
 473 +        lookup.id = (char *)timezone;
 474 +
 475 +        ent = bsearch(&lookup, timezonedb_system->index,
 476 +                      timezonedb_system->index_size, sizeof lookup,
 477 +                      sysdbcmp);
 478 +        if (ent) {
 479 +            return ent->id;
 480 +        }
 481 +    }
 482 +
 483 +    return timezone;
 484 +}
 485 +
 486 +/* Return the mmap()ed tzfile if found, else NULL.  On success, the
 487 + * length of the mapped data is placed in *length. */
 488 +static char *map_tzfile(const char *timezone, size_t *length)
 489 +{
 490 +       char fname[PATH_MAX];
 491 +       struct stat st;
 492 +       char *p;
 493 +       int fd;
 494 +
 495 +       if (timezone[0] == '\0' || strstr(timezone, "..") != NULL) {
 496 +               return NULL;
 497 +       }
 498 +
 499 +       snprintf(fname, sizeof fname, ZONEINFO_PREFIX "/%s", canonical_tzname(timezone));
 500 +
 501 +       fd = open(fname, O_RDONLY);
 502 +       if (fd == -1) {
 503 +               return NULL;
 504 +       } else if (fstat(fd, &st) != 0 || !is_valid_tzfile(&st, fd)) {
 505 +               close(fd);
 506 +               return NULL;
 507 +       }
 508 +
 509 +       *length = st.st_size;
 510 +       p = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
 511 +       close(fd);
 512 +
 513 +       return p != MAP_FAILED ? p : NULL;
 514 +}
 515 +
 516 +#endif
 517 +
 518 +static int inmem_seek_to_tz_position(const unsigned char **tzf, char *timezone, const timelib_tzdb *tzdb)
 519  {
 520         int left = 0, right = tzdb->index_size - 1;
 521
 522 @@ -400,9 +840,48 @@ static int seek_to_tz_position(const uns
 523         return 0;
 524  }
 525
 526 +static int seek_to_tz_position(const unsigned char **tzf, char *timezone,
 527 +                              char **map, size_t *maplen,
 528 +                              const timelib_tzdb *tzdb)
 529 +{
 530 +#ifdef HAVE_SYSTEM_TZDATA
 531 +       if (tzdb == timezonedb_system) {
 532 +               char *orig;
 533 +
 534 +               orig = map_tzfile(timezone, maplen);
 535 +               if (orig == NULL) {
 536 +                       return 0;
 537 +               }
 538 +
 539 +               (*tzf) = (unsigned char *)orig;
 540 +               *map = orig;
 541 +        return 1;
 542 +       }
 543 +       else
 544 +#endif
 545 +       {
 546 +               return inmem_seek_to_tz_position(tzf, timezone, tzdb);
 547 +       }
 548 +}
 549 +
 550  const timelib_tzdb *timelib_builtin_db(void)
 551  {
 552 +#ifdef HAVE_SYSTEM_TZDATA
 553 +       if (timezonedb_system == NULL) {
 554 +               timelib_tzdb *tmp = malloc(sizeof *tmp);
 555 +
 556 +               tmp->version = "0.system";
 557 +               tmp->data = NULL;
 558 +               create_zone_index(tmp);
 559 +               system_location_table = create_location_table();
 560 +               fake_data_segment(tmp, system_location_table);
 561 +               timezonedb_system = tmp;
 562 +       }
 563 +
 564 +       return timezonedb_system;
 565 +#else
 566         return &timezonedb_builtin;
 567 +#endif
 568  }
 569
 570  const timelib_tzdb_index_entry *timelib_timezone_identifiers_list(const timelib_tzdb *tzdb, int *count)
 571 @@ -414,7 +893,30 @@ const timelib_tzdb_index_entry *timelib_
 572  int timelib_timezone_id_is_valid(char *timezone, const timelib_tzdb *tzdb)
 573  {
 574         const unsigned char *tzf;
 575 -       return (seek_to_tz_position(&tzf, timezone, tzdb));
 576 +
 577 +#ifdef HAVE_SYSTEM_TZDATA
 578 +       if (tzdb == timezonedb_system) {
 579 +               char fname[PATH_MAX];
 580 +               struct stat st;
 581 +
 582 +               if (timezone[0] == '\0' || strstr(timezone, "..") != NULL) {
 583 +                       return 0;
 584 +               }
 585 +
 586 +               if (system_location_table) {
 587 +                       if (find_zone_info(system_location_table, timezone) != NULL) {
 588 +                               /* found in cache */
 589 +                               return 1;
 590 +                       }
 591 +               }
 592 +
 593 +               snprintf(fname, sizeof fname, ZONEINFO_PREFIX "/%s", canonical_tzname(timezone));
 594 +
 595 +               return stat(fname, &st) == 0 && is_valid_tzfile(&st, 0);
 596 +       }
 597 +#endif
 598 +
 599 +       return (inmem_seek_to_tz_position(&tzf, timezone, tzdb));
 600  }
 601
 602  static int skip_64bit_preamble(const unsigned char **tzf, timelib_tzinfo *tz)
 603 @@ -456,12 +958,14 @@ static timelib_tzinfo* timelib_tzinfo_ct
 604  timelib_tzinfo *timelib_parse_tzfile(char *timezone, const timelib_tzdb *tzdb, int *error_code)
 605  {
 606         const unsigned char *tzf;
 607 +       char *memmap = NULL;
 608 +       size_t maplen;
 609         timelib_tzinfo *tmp;
 610         int version;
 611         int transitions_result, types_result;
 612         unsigned int type; /* TIMELIB_TZINFO_PHP or TIMELIB_TZINFO_ZONEINFO */
 613
 614 -       if (seek_to_tz_position(&tzf, timezone, tzdb)) {
 615 +       if (seek_to_tz_position(&tzf, timezone, &memmap, &maplen, tzdb)) {
 616                 tmp = timelib_tzinfo_ctor(timezone);
 617
 618                 version = read_preamble(&tzf, tmp, &type);
 619 @@ -484,6 +988,29 @@ timelib_tzinfo *timelib_parse_tzfile(cha
 620                         timelib_tzinfo_dtor(tmp);
 621                         return NULL;
 622                 }
 623 +
 624 +#ifdef HAVE_SYSTEM_TZDATA
 625 +               if (memmap) {
 626 +                       const struct location_info *li;
 627 +
 628 +                       /* TZif-style - grok the location info from the system database,
 629 +                        * if possible. */
 630 +
 631 +                       if ((li = find_zone_info(system_location_table, timezone)) != NULL) {
 632 +                               tmp->location.comments = timelib_strdup(li->comment);
 633 +                               strncpy(tmp->location.country_code, li->code, 2);
 634 +                               tmp->location.longitude = li->longitude;
 635 +                               tmp->location.latitude = li->latitude;
 636 +                               tmp->bc = 1;
 637 +                       }
 638 +                       else {
 639 +                               set_default_location_and_comments(&tzf, tmp);
 640 +                       }
 641 +
 642 +                       /* Now done with the mmap segment - discard it. */
 643 +                       munmap(memmap, maplen);
 644 +               } else {
 645 +#endif
 646                 if (version == 2 || version == 3) {
 647                         if (!skip_64bit_preamble(&tzf, tmp)) {
 648                                 /* 64 bit preamble is not in place */
 649 @@ -501,6 +1028,9 @@ timelib_tzinfo *timelib_parse_tzfile(cha
 650                 } else {
 651                         set_default_location_and_comments(&tzf, tmp);
 652                 }
 653 +#ifdef HAVE_SYSTEM_TZDATA
 654 +               }
 655 +#endif
 656         } else {
 657                 *error_code = TIMELIB_ERROR_NO_SUCH_TIMEZONE;
 658                 tmp = NULL;