974 lines
40 KiB
C++
974 lines
40 KiB
C++
/* -------------------------------------------------------------------------
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*
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* findtimezone.c
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* Functions for determining the default timezone to use.
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*
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* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
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*
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* IDENTIFICATION
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* src/bin/initdb/findtimezone.c
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*
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* -------------------------------------------------------------------------
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*/
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#include "postgres_fe.h"
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#include <time.h>
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#include <fcntl.h>
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#include "pgtz.h"
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#include "bin/elog.h"
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#define TZNAME_LENGTH 128
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#define LOCAL_TZNAME_LENGTH 256
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/* Ideally this would be in a .h file, but it hardly seems worth the trouble */
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extern const char* select_default_timezone(const char* share_path);
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#ifndef SYSTEMTZDIR
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static char tzdirpath[MAXPGPATH];
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#endif
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#ifndef ERROR_LIMIT_LEN
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#define ERROR_LIMIT_LEN 256
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#endif
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/*
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* Return full pathname of timezone data directory
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*
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* In this file, tzdirpath is assumed to be set up by select_default_timezone.
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*/
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static const char* pg_TZDIR(void)
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{
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#ifndef SYSTEMTZDIR
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/* normal case: timezone stuff is under our share dir */
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return tzdirpath;
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#else
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/* we're configured to use system's timezone database */
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return SYSTEMTZDIR;
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#endif
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}
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/*
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* Given a timezone name, open() the timezone data file. Return the
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* file descriptor if successful, -1 if not.
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*
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* This is simpler than the backend function of the same name because
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* we assume that the input string has the correct case already, so there
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* is no need for case-folding. (This is obviously true if we got the file
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* name from the filesystem to start with. The only other place it can come
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* from is the environment variable TZ, and there seems no need to allow
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* case variation in that; other programs aren't likely to.)
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*
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* If "canonname" is not NULL, then on success the canonical spelling of the
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* given name is stored there (the buffer must be > TZ_STRLEN_MAX bytes!).
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* This is redundant but kept for compatibility with the backend code.
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*/
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int pg_open_tzfile(const char* name, char* canonname)
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{
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char fullname[MAXPGPATH];
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errno_t rc = 0;
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if (canonname != NULL) {
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rc = strncpy_s(canonname, TZ_STRLEN_MAX + 1, name, TZ_STRLEN_MAX);
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securec_check_c(rc, "\0", "\0");
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}
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rc = strcpy_s(fullname, MAXPGPATH, pg_TZDIR());
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securec_check_c(rc, "\0", "\0");
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if (strlen(fullname) + 1 + strlen(name) >= MAXPGPATH)
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return -1; /* not gonna fit */
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rc = strcat_s(fullname, MAXPGPATH, "/");
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securec_check_c(rc, "\0", "\0");
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rc = strcat_s(fullname, MAXPGPATH, name);
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securec_check_c(rc, "\0", "\0");
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return open(fullname, O_RDONLY | PG_BINARY, 0);
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}
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/*
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* Load a timezone definition.
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* Does not verify that the timezone is acceptable!
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*
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* This corresponds to the backend's pg_tzset(), except that we only support
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* one loaded timezone at a time.
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*/
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static pg_tz* pg_load_tz(const char* name)
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{
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static pg_tz tz;
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errno_t rc = 0;
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if (strlen(name) > TZ_STRLEN_MAX)
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return NULL; /* not going to fit */
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/*
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* "GMT" is always sent to tzparse(); see comments for pg_tzset().
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*/
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if (strcmp(name, "GMT") == 0) {
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if (tzparse(name, &tz.state, TRUE) != 0) {
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/* This really, really should not happen ... */
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return NULL;
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}
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} else if (tzload(name, NULL, &tz.state, TRUE) != 0) {
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if (name[0] == ':' || tzparse(name, &tz.state, FALSE) != 0) {
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return NULL; /* unknown timezone */
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}
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}
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rc = strcpy_s(tz.TZname, (TZ_STRLEN_MAX + 1), name);
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securec_check_c(rc, "\0", "\0");
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return &tz;
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}
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/*
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* The following block of code attempts to determine which timezone in our
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* timezone database is the best match for the active system timezone.
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*
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* On most systems, we rely on trying to match the observable behavior of
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* the C library's localtime() function. The database zone that matches
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* furthest into the past is the one to use. Often there will be several
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* zones with identical rankings (since the Olson database assigns multiple
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* names to many zones). We break ties arbitrarily by preferring shorter,
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* then alphabetically earlier zone names.
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*
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* Win32's native knowledge about timezones appears to be too incomplete
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* and too different from the Olson database for the above matching strategy
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* to be of any use. But there is just a limited number of timezones
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* available, so we can rely on a handmade mapping table instead.
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*/
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#ifndef WIN32
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#define T_DAY ((time_t)(60 * 60 * 24))
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#define T_WEEK ((time_t)(60 * 60 * 24 * 7))
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#define T_MONTH ((time_t)(60 * 60 * 24 * 31))
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#define MAX_TEST_TIMES (52 * 100) /* 100 years */
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struct tztry {
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int n_test_times;
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time_t test_times[MAX_TEST_TIMES];
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};
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/*
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* Get GMT offset from a system struct tm
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*/
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static int get_timezone_offset(struct tm* tm_val)
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{
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#if defined(HAVE_STRUCT_TM_TM_ZONE)
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return tm_val->tm_gmtoff;
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#elif defined(HAVE_INT_TIMEZONE)
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return -TIMEZONE_GLOBAL;
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#else
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#error No way to determine TZ? Can this happen?
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#endif
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}
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/*
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* Convenience subroutine to convert y/m/d to time_t (NOT pg_time_t)
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*/
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static time_t build_time_t(int year, int month, int day)
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{
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struct tm tm_val;
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errno_t rc = 0;
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rc = memset_s(&tm_val, sizeof(tm_val), 0, sizeof(tm_val));
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securec_check_c(rc, "\0", "\0");
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tm_val.tm_mday = day;
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tm_val.tm_mon = month - 1;
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tm_val.tm_year = year - 1900;
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return mktime(&tm_val);
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}
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/*
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* Does a system tm value match one we computed ourselves?
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*/
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static bool compare_tm(struct tm* s, struct pg_tm* p)
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{
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if (s->tm_sec != p->tm_sec || s->tm_min != p->tm_min || s->tm_hour != p->tm_hour || s->tm_mday != p->tm_mday ||
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s->tm_mon != p->tm_mon || s->tm_year != p->tm_year || s->tm_wday != p->tm_wday || s->tm_yday != p->tm_yday ||
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s->tm_isdst != p->tm_isdst)
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return false;
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return true;
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}
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/*
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* See how well a specific timezone setting matches the system behavior
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*
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* We score a timezone setting according to the number of test times it
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* matches. (The test times are ordered later-to-earlier, but this routine
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* doesn't actually know that; it just scans until the first non-match.)
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*
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* We return -1 for a completely unusable setting; this is worse than the
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* score of zero for a setting that works but matches not even the first
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* test time.
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*/
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static int score_timezone(const char* tz_name, struct tztry* tt)
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{
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int i;
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pg_time_t pgtt;
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struct tm* systm = NULL;
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struct pg_tm* pgtm = NULL;
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char cbuf[TZ_STRLEN_MAX + 1];
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pg_tz* tz = NULL;
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errno_t rc = 0;
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/* Load timezone definition */
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tz = pg_load_tz(tz_name);
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if (tz == NULL)
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return -1; /* unrecognized zone name */
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/* Reject if leap seconds involved */
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if (!pg_tz_acceptable(tz)) {
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#ifdef DEBUG_IDENTIFY_TIMEZONE
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write_stderr("Reject TZ \"%s\": uses leap seconds\n", tz_name);
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#endif
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return -1;
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}
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/* Check for match at all the test times */
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for (i = 0; i < tt->n_test_times; i++) {
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pgtt = (pg_time_t)(tt->test_times[i]);
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pgtm = pg_localtime(&pgtt, tz);
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if (pgtm == NULL) {
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return -1; /* probably shouldn't happen */
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}
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systm = localtime(&(tt->test_times[i]));
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if (systm == NULL) {
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#ifdef DEBUG_IDENTIFY_TIMEZONE
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write_stderr("TZ \"%s\" scores %d: at %ld %04d-%02d-%02d %02d:%02d:%02d %s, system had no data\n",
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tz_name,
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i,
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(long)pgtt,
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pgtm->tm_year + 1900,
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pgtm->tm_mon + 1,
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pgtm->tm_mday,
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pgtm->tm_hour,
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pgtm->tm_min,
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pgtm->tm_sec,
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pgtm->tm_isdst ? "dst" : "std");
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#endif
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return i;
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}
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if (!compare_tm(systm, pgtm)) {
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#ifdef DEBUG_IDENTIFY_TIMEZONE
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write_stderr("TZ \"%s\" scores %d: at %ld %04d-%02d-%02d %02d:%02d:%02d %s versus %04d-%02d-%02d "
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"%02d:%02d:%02d %s\n",
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tz_name,
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i,
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(long)pgtt,
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pgtm->tm_year + 1900,
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pgtm->tm_mon + 1,
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pgtm->tm_mday,
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pgtm->tm_hour,
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pgtm->tm_min,
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pgtm->tm_sec,
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pgtm->tm_isdst ? "dst" : "std",
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systm->tm_year + 1900,
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systm->tm_mon + 1,
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systm->tm_mday,
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systm->tm_hour,
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systm->tm_min,
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systm->tm_sec,
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systm->tm_isdst ? "dst" : "std");
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#endif
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return i;
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}
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if (systm->tm_isdst >= 0) {
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/* Check match of zone names, too */
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if (pgtm->tm_zone == NULL)
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return -1; /* probably shouldn't happen */
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rc = memset_s(cbuf, (TZ_STRLEN_MAX + 1), 0, sizeof(cbuf));
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securec_check_c(rc, "\0", "\0");
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(void)strftime(cbuf, sizeof(cbuf) - 1, "%Z", systm); /* zone abbr */
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if (strcmp(cbuf, pgtm->tm_zone) != 0) {
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#ifdef DEBUG_IDENTIFY_TIMEZONE
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write_stderr(
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"TZ \"%s\" scores %d: at %ld \"%s\" versus \"%s\"\n", tz_name, i, (long)pgtt, pgtm->tm_zone, cbuf);
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#endif
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return i;
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}
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}
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}
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#ifdef DEBUG_IDENTIFY_TIMEZONE
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write_stderr("TZ \"%s\" gets max score %d\n", tz_name, i);
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#endif
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return i;
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}
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/*
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* Try to identify a timezone name (in our terminology) that best matches the
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* observed behavior of the system timezone library. We cannot assume that
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* the system TZ environment setting (if indeed there is one) matches our
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* terminology, so we ignore it and just look at what localtime() returns.
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*/
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const char* identify_system_timezone(void)
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{
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static char resultbuf[TZ_STRLEN_MAX + 1];
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time_t tnow;
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time_t t;
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struct tztry tt = {0};
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struct tm* tm_val = NULL;
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int thisyear;
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int bestscore;
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char tmptzdir[MAXPGPATH];
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int std_ofs;
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char std_zone_name[TZ_STRLEN_MAX + 1], dst_zone_name[TZ_STRLEN_MAX + 1];
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char cbuf[TZ_STRLEN_MAX + 1];
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errno_t rc = 0;
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int nRet = 0;
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/* Initialize OS timezone library */
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tzset();
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/*
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* Set up the list of dates to be probed to see how well our timezone
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* matches the system zone. We first probe January and July of the
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* current year; this serves to quickly eliminate the vast majority of the
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* TZ database entries. If those dates match, we probe every week for 100
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* years backwards from the current July. (Weekly resolution is good
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* enough to identify DST transition rules, since everybody switches on
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* Sundays.) This is sufficient to cover most of the Unix time_t range,
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* and we don't want to look further than that since many systems won't
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* have sane TZ behavior further back anyway. The further back the zone
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* matches, the better we score it. This may seem like a rather random
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* way of doing things, but experience has shown that system-supplied
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* timezone definitions are likely to have DST behavior that is right for
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* the recent past and not so accurate further back. Scoring in this way
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* allows us to recognize zones that have some commonality with the Olson
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* database, without insisting on exact match. (Note: we probe Thursdays,
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* not Sundays, to avoid triggering DST-transition bugs in localtime
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* itself.)
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*/
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tnow = time(NULL);
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tm_val = localtime(&tnow);
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if (tm_val == NULL) {
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return NULL; /* give up if localtime is broken... */
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}
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thisyear = tm_val->tm_year + 1900;
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t = build_time_t(thisyear, 1, 15);
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/*
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* Round back to GMT midnight Thursday. This depends on the knowledge
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* that the time_t origin is Thu Jan 01 1970. (With a different origin
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* we'd be probing some other day of the week, but it wouldn't matter
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* anyway unless localtime() had DST-transition bugs.)
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*/
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t -= (t % T_WEEK);
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tt.n_test_times = 0;
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tt.test_times[tt.n_test_times++] = t;
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t = build_time_t(thisyear, 7, 15);
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t -= (t % T_WEEK);
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tt.test_times[tt.n_test_times++] = t;
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while (tt.n_test_times < MAX_TEST_TIMES) {
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t -= T_WEEK;
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tt.test_times[tt.n_test_times++] = t;
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}
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/* Search for the best-matching timezone file */
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rc = strncpy_s(tmptzdir, MAXPGPATH, pg_TZDIR(), MAXPGPATH - 1);
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securec_check_c(rc, "\0", "\0");
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bestscore = -1;
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resultbuf[0] = '\0';
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scan_available_timezones(tmptzdir, tmptzdir + strlen(tmptzdir) + 1, &tt, &bestscore, resultbuf);
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if (bestscore > 0) {
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/* Ignore Olson's rather silly "Factory" zone; use GMT instead */
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if (strcmp(resultbuf, "Factory") == 0)
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return NULL;
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return resultbuf;
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}
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/*
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* Couldn't find a match in the database, so next we try constructed zone
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* names (like "PST8PDT").
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*
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* First we need to determine the names of the local standard and daylight
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* zones. The idea here is to scan forward from today until we have seen
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* both zones, if both are in use.
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*/
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rc = memset_s(std_zone_name, (TZ_STRLEN_MAX + 1), 0, sizeof(std_zone_name));
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securec_check_c(rc, "\0", "\0");
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rc = memset_s(dst_zone_name, (TZ_STRLEN_MAX + 1), 0, sizeof(dst_zone_name));
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securec_check_c(rc, "\0", "\0");
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std_ofs = 0;
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tnow = time(NULL);
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/*
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* Round back to a GMT midnight so results don't depend on local time of
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* day
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*/
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tnow -= (tnow % T_DAY);
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/*
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* We have to look a little further ahead than one year, in case today is
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* just past a DST boundary that falls earlier in the year than the next
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* similar boundary. Arbitrarily scan up to 14 months.
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*/
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for (t = tnow; t <= tnow + T_MONTH * 14; t += T_MONTH) {
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tm_val = localtime(&t);
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if (tm_val == NULL) {
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continue;
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}
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if (tm_val->tm_isdst < 0) {
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continue;
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}
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if (tm_val->tm_isdst == 0 && std_zone_name[0] == '\0') {
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/* found STD zone */
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rc = memset_s(cbuf, (TZ_STRLEN_MAX + 1), 0, sizeof(cbuf));
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securec_check_c(rc, "\0", "\0");
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(void)strftime(cbuf, sizeof(cbuf) - 1, "%Z", tm_val); /* zone abbr */
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rc = strcpy_s(std_zone_name, (TZ_STRLEN_MAX + 1), cbuf);
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securec_check_c(rc, "\0", "\0");
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std_ofs = get_timezone_offset(tm_val);
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}
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if (tm_val->tm_isdst > 0 && dst_zone_name[0] == '\0') {
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/* found DST zone */
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rc = memset_s(cbuf, (TZ_STRLEN_MAX + 1), 0, sizeof(cbuf));
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securec_check_c(rc, "\0", "\0");
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(void)strftime(cbuf, sizeof(cbuf) - 1, "%Z", tm_val); /* zone abbr */
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rc = strcpy_s(dst_zone_name, (TZ_STRLEN_MAX + 1), cbuf);
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securec_check_c(rc, "\0", "\0");
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}
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/* Done if found both */
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if (std_zone_name[0] && dst_zone_name[0])
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break;
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}
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/* We should have found a STD zone name by now... */
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if (std_zone_name[0] == '\0') {
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#ifdef DEBUG_IDENTIFY_TIMEZONE
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write_stderr("could not determine system time zone\n");
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#endif
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return NULL; /* go to GMT */
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}
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|
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/* If we found DST then try STD<ofs>DST */
|
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if (dst_zone_name[0] != '\0') {
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nRet = snprintf_s(resultbuf,
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sizeof(resultbuf),
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sizeof(resultbuf) - 1,
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"%s%d%s",
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std_zone_name,
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-std_ofs / 3600,
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dst_zone_name);
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securec_check_ss_c(nRet, "\0", "\0");
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if (score_timezone(resultbuf, &tt) > 0)
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return resultbuf;
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}
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|
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/* Try just the STD timezone (works for GMT at least) */
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rc = strcpy_s(resultbuf, (TZ_STRLEN_MAX + 1), std_zone_name);
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securec_check_c(rc, "\0", "\0");
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if (score_timezone(resultbuf, &tt) > 0)
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return resultbuf;
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|
|
/* Try STD<ofs> */
|
|
nRet = snprintf_s(resultbuf, sizeof(resultbuf), sizeof(resultbuf) - 1, "%s%d", std_zone_name, -std_ofs / 3600);
|
|
securec_check_ss_c(nRet, "\0", "\0");
|
|
if (score_timezone(resultbuf, &tt) > 0)
|
|
return resultbuf;
|
|
|
|
/*
|
|
* Did not find the timezone. Fallback to use a GMT zone. Note that the
|
|
* Olson timezone database names the GMT-offset zones in POSIX style: plus
|
|
* is west of Greenwich. It's unfortunate that this is opposite of SQL
|
|
* conventions. Should we therefore change the names? Probably not...
|
|
*/
|
|
nRet = snprintf_s(
|
|
resultbuf, sizeof(resultbuf), sizeof(resultbuf) - 1, "Etc/GMT%s%d", (-std_ofs > 0) ? "+" : "", -std_ofs / 3600);
|
|
securec_check_ss_c(nRet, "\0", "\0");
|
|
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr("could not recognize system time zone, using \"%s\"\n", resultbuf);
|
|
#endif
|
|
return resultbuf;
|
|
}
|
|
|
|
/*
|
|
* Recursively scan the timezone database looking for the best match to
|
|
* the system timezone behavior.
|
|
*
|
|
* tzdir points to a buffer of size MAXPGPATH. On entry, it holds the
|
|
* pathname of a directory containing TZ files. We internally modify it
|
|
* to hold pathnames of sub-directories and files, but must restore it
|
|
* to its original contents before exit.
|
|
*
|
|
* tzdirsub points to the part of tzdir that represents the subfile name
|
|
* (ie, tzdir + the original directory name length, plus one for the
|
|
* first added '/').
|
|
*
|
|
* tt tells about the system timezone behavior we need to match.
|
|
*
|
|
* *bestscore and *bestzonename on entry hold the best score found so far
|
|
* and the name of the best zone. We overwrite them if we find a better
|
|
* score. bestzonename must be a buffer of length TZ_STRLEN_MAX + 1.
|
|
*/
|
|
void scan_available_timezones(char* tzdir, char* tzdirsub, struct tztry* tt, int* bestscore, char* bestzonename)
|
|
{
|
|
int tzdir_orig_len = strlen(tzdir);
|
|
char** names;
|
|
char** namep;
|
|
|
|
names = pgfnames(tzdir);
|
|
if (names == NULL) {
|
|
return;
|
|
}
|
|
|
|
for (namep = names; *namep != NULL; namep++) {
|
|
char* name = *namep;
|
|
struct stat statbuf;
|
|
int nRet = 0;
|
|
|
|
/* Ignore . and .., plus any other "hidden" files */
|
|
if (name[0] == '.') {
|
|
continue;
|
|
}
|
|
|
|
nRet = snprintf_s(
|
|
tzdir + tzdir_orig_len, (MAXPGPATH - tzdir_orig_len), MAXPGPATH - tzdir_orig_len - 1, "/%s", name);
|
|
securec_check_ss_c(nRet, "\0", "\0");
|
|
|
|
if (stat(tzdir, &statbuf) != 0) {
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
char errBuffer[ERROR_LIMIT_LEN];
|
|
write_stderr("could not stat \"%s\": %s\n", tzdir, pqStrerror(errno, errBuffer, ERROR_LIMIT_LEN));
|
|
#endif
|
|
tzdir[tzdir_orig_len] = '\0';
|
|
continue;
|
|
}
|
|
|
|
if (S_ISDIR(statbuf.st_mode)) {
|
|
/* Recurse into subdirectory */
|
|
scan_available_timezones(tzdir, tzdirsub, tt, bestscore, bestzonename);
|
|
} else {
|
|
/* Load and test this file */
|
|
int score = score_timezone(tzdirsub, tt);
|
|
|
|
if (score > *bestscore) {
|
|
*bestscore = score;
|
|
nRet = strncpy_s(bestzonename, TZ_STRLEN_MAX + 1, tzdirsub, TZ_STRLEN_MAX);
|
|
securec_check_ss_c(nRet, "\0", "\0");
|
|
} else if (score == *bestscore) {
|
|
/* Consider how to break a tie */
|
|
if (strlen(tzdirsub) < strlen(bestzonename) ||
|
|
(strlen(tzdirsub) == strlen(bestzonename) && strcmp(tzdirsub, bestzonename) < 0)) {
|
|
nRet = strncpy_s(bestzonename, TZ_STRLEN_MAX + 1, tzdirsub, TZ_STRLEN_MAX);
|
|
securec_check_ss_c(nRet, "\0", "\0");
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Restore tzdir */
|
|
tzdir[tzdir_orig_len] = '\0';
|
|
}
|
|
|
|
pgfnames_cleanup(names);
|
|
}
|
|
#else /* WIN32 */
|
|
|
|
static const struct {
|
|
const char* stdname; /* Windows name of standard timezone */
|
|
const char* dstname; /* Windows name of daylight timezone */
|
|
const char* pgtzname; /* Name of pgsql timezone to map to */
|
|
} win32_tzmap[] =
|
|
|
|
{
|
|
/*
|
|
* This list was built from the contents of the registry at
|
|
* HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time
|
|
* Zones on Windows 2003 R2.
|
|
*
|
|
* The zones have been matched to Olson timezones by looking at the cities
|
|
* listed in the win32 display name (in the comment here) in most cases.
|
|
*/
|
|
{"Afghanistan Standard Time", "Afghanistan Daylight Time", "Asia/Kabul"}, /* (GMT+04:30) Kabul */
|
|
{"Alaskan Standard Time", "Alaskan Daylight Time", "US/Alaska"}, /* (GMT-09:00) Alaska */
|
|
{"Arab Standard Time", "Arab Daylight Time", "Asia/Kuwait"}, /* (GMT+03:00) Kuwait, Riyadh */
|
|
{"Arabian Standard Time", "Arabian Daylight Time", "Asia/Muscat"}, /* (GMT+04:00) Abu Dhabi, Muscat */
|
|
{"Arabic Standard Time", "Arabic Daylight Time", "Asia/Baghdad"}, /* (GMT+03:00) Baghdad */
|
|
{"Argentina Standard Time", "Argentina Daylight Time", "America/Buenos_Aires"}, /* (GMT-03:00) Buenos Aires */
|
|
{"Armenian Standard Time", "Armenian Daylight Time", "Asia/Yerevan"}, /* (GMT+04:00) Yerevan */
|
|
{"Atlantic Standard Time",
|
|
"Atlantic Daylight Time",
|
|
"Canada/Atlantic"}, /* (GMT-04:00) Atlantic Time (Canada) */
|
|
{"AUS Central Standard Time", "AUS Central Daylight Time", "Australia/Darwin"}, /* (GMT+09:30) Darwin */
|
|
{"AUS Eastern Standard Time",
|
|
"AUS Eastern Daylight Time",
|
|
"Australia/Canberra"}, /* (GMT+10:00) Canberra, Melbourne, Sydney */
|
|
{"Azerbaijan Standard Time", "Azerbaijan Daylight Time", "Asia/Baku"}, /* (GMT+04:00) Baku */
|
|
{"Azores Standard Time", "Azores Daylight Time", "Atlantic/Azores"}, /* (GMT-01:00) Azores */
|
|
{"Bangladesh Standard Time", "Bangladesh Daylight Time", "Asia/Dhaka"}, /* (GMT+06:00) Dhaka */
|
|
{"Canada Central Standard Time",
|
|
"Canada Central Daylight Time",
|
|
"Canada/Saskatchewan"}, /* (GMT-06:00) Saskatchewan */
|
|
{"Cape Verde Standard Time",
|
|
"Cape Verde Daylight Time",
|
|
"Atlantic/Cape_Verde"}, /* (GMT-01:00) Cape Verde Is. */
|
|
{"Caucasus Standard Time", "Caucasus Daylight Time", "Asia/Baku"}, /* (GMT+04:00) Baku, Tbilisi, Yerevan */
|
|
{"Cen. Australia Standard Time",
|
|
"Cen. Australia Daylight Time",
|
|
"Australia/Adelaide"}, /* (GMT+09:30) Adelaide */
|
|
/* Central America (other than Mexico) generally does not observe DST */
|
|
{"Central America Standard Time", "Central America Daylight Time", "CST6"}, /* (GMT-06:00) Central America */
|
|
{"Central Asia Standard Time", "Central Asia Daylight Time", "Asia/Dhaka"}, /* (GMT+06:00) Astana, Dhaka */
|
|
{"Central Brazilian Standard Time",
|
|
"Central Brazilian Daylight Time",
|
|
"America/Cuiaba"}, /* (GMT-04:00) Cuiaba */
|
|
{"Central Europe Standard Time",
|
|
"Central Europe Daylight Time",
|
|
"Europe/Belgrade"}, /* (GMT+01:00) Belgrade, Bratislava, Budapest,
|
|
* Ljubljana, Prague */
|
|
{"Central European Standard Time",
|
|
"Central European Daylight Time",
|
|
"Europe/Sarajevo"}, /* (GMT+01:00) Sarajevo, Skopje, Warsaw,
|
|
* Zagreb */
|
|
{"Central Pacific Standard Time",
|
|
"Central Pacific Daylight Time",
|
|
"Pacific/Noumea"}, /* (GMT+11:00) Magadan, Solomon Is., New
|
|
* Caledonia */
|
|
{"Central Standard Time", "Central Daylight Time", "US/Central"}, /* (GMT-06:00) Central Time (US & Canada) */
|
|
{"Central Standard Time (Mexico)",
|
|
"Central Daylight Time (Mexico)",
|
|
"America/Mexico_City"}, /* (GMT-06:00) Guadalajara, Mexico City,
|
|
* Monterrey - New */
|
|
{"China Standard Time", "China Daylight Time", "Asia/Hong_Kong"}, /* (GMT+08:00) Beijing, Chongqing, Hong Kong,
|
|
* Urumqi */
|
|
{"Dateline Standard Time",
|
|
"Dateline Daylight Time",
|
|
"Etc/GMT+12"}, /* (GMT-12:00) International Date Line West */
|
|
{"E. Africa Standard Time", "E. Africa Daylight Time", "Africa/Nairobi"}, /* (GMT+03:00) Nairobi */
|
|
{"E. Australia Standard Time", "E. Australia Daylight Time", "Australia/Brisbane"}, /* (GMT+10:00) Brisbane */
|
|
{"E. Europe Standard Time", "E. Europe Daylight Time", "Europe/Bucharest"}, /* (GMT+02:00) Bucharest */
|
|
{"E. South America Standard Time",
|
|
"E. South America Daylight Time",
|
|
"America/Araguaina"}, /* (GMT-03:00) Brasilia */
|
|
{"Eastern Standard Time", "Eastern Daylight Time", "US/Eastern"}, /* (GMT-05:00) Eastern Time (US & Canada) */
|
|
{"Egypt Standard Time", "Egypt Daylight Time", "Africa/Cairo"}, /* (GMT+02:00) Cairo */
|
|
{"Ekaterinburg Standard Time",
|
|
"Ekaterinburg Daylight Time",
|
|
"Asia/Yekaterinburg"}, /* (GMT+05:00) Ekaterinburg */
|
|
{"Fiji Standard Time", "Fiji Daylight Time", "Pacific/Fiji"}, /* (GMT+12:00) Fiji, Kamchatka, Marshall Is. */
|
|
{"FLE Standard Time", "FLE Daylight Time", "Europe/Helsinki"}, /* (GMT+02:00) Helsinki, Kyiv, Riga, Sofia,
|
|
* Tallinn, Vilnius */
|
|
{"Georgian Standard Time", "Georgian Daylight Time", "Asia/Tbilisi"}, /* (GMT+03:00) Tbilisi */
|
|
{"GMT Standard Time", "GMT Daylight Time", "Europe/London"}, /* (GMT) Greenwich Mean Time : Dublin,
|
|
* Edinburgh, Lisbon, London */
|
|
{"Greenland Standard Time", "Greenland Daylight Time", "America/Godthab"}, /* (GMT-03:00) Greenland */
|
|
{"Greenwich Standard Time", "Greenwich Daylight Time", "Africa/Casablanca"}, /* (GMT) Casablanca, Monrovia */
|
|
{"GTB Standard Time", "GTB Daylight Time", "Europe/Athens"}, /* (GMT+02:00) Athens, Istanbul, Minsk */
|
|
{"Hawaiian Standard Time", "Hawaiian Daylight Time", "US/Hawaii"}, /* (GMT-10:00) Hawaii */
|
|
{"India Standard Time", "India Daylight Time", "Asia/Calcutta"}, /* (GMT+05:30) Chennai, Kolkata, Mumbai, New
|
|
* Delhi */
|
|
{"Iran Standard Time", "Iran Daylight Time", "Asia/Tehran"}, /* (GMT+03:30) Tehran */
|
|
{"Jerusalem Standard Time", "Jerusalem Daylight Time", "Asia/Jerusalem"}, /* (GMT+02:00) Jerusalem */
|
|
{"Jordan Standard Time", "Jordan Daylight Time", "Asia/Amman"}, /* (GMT+02:00) Amman */
|
|
{"Kamchatka Standard Time",
|
|
"Kamchatka Daylight Time",
|
|
"Asia/Kamchatka"}, /* (GMT+12:00) Petropavlovsk-Kamchatsky */
|
|
{"Korea Standard Time", "Korea Daylight Time", "Asia/Seoul"}, /* (GMT+09:00) Seoul */
|
|
{"Mauritius Standard Time", "Mauritius Daylight Time", "Indian/Mauritius"}, /* (GMT+04:00) Port Louis */
|
|
{"Mexico Standard Time", "Mexico Daylight Time", "America/Mexico_City"}, /* (GMT-06:00) Guadalajara, Mexico
|
|
* City, Monterrey */
|
|
{"Mexico Standard Time 2",
|
|
"Mexico Daylight Time 2",
|
|
"America/Chihuahua"}, /* (GMT-07:00) Chihuahua, La Paz, Mazatlan */
|
|
{"Mid-Atlantic Standard Time",
|
|
"Mid-Atlantic Daylight Time",
|
|
"Atlantic/South_Georgia"}, /* (GMT-02:00) Mid-Atlantic */
|
|
{"Middle East Standard Time", "Middle East Daylight Time", "Asia/Beirut"}, /* (GMT+02:00) Beirut */
|
|
{"Montevideo Standard Time", "Montevideo Daylight Time", "America/Montevideo"}, /* (GMT-03:00) Montevideo */
|
|
{"Morocco Standard Time", "Morocco Daylight Time", "Africa/Casablanca"}, /* (GMT) Casablanca */
|
|
{"Mountain Standard Time",
|
|
"Mountain Daylight Time",
|
|
"US/Mountain"}, /* (GMT-07:00) Mountain Time (US & Canada) */
|
|
{"Mountain Standard Time (Mexico)",
|
|
"Mountain Daylight Time (Mexico)",
|
|
"America/Chihuahua"}, /* (GMT-07:00) Chihuahua, La Paz, Mazatlan -
|
|
* New */
|
|
{"Myanmar Standard Time", "Myanmar Daylight Time", "Asia/Rangoon"}, /* (GMT+06:30) Rangoon */
|
|
{"N. Central Asia Standard Time",
|
|
"N. Central Asia Daylight Time",
|
|
"Asia/Novosibirsk"}, /* (GMT+06:00) Novosibirsk */
|
|
{"Namibia Standard Time", "Namibia Daylight Time", "Africa/Windhoek"}, /* (GMT+02:00) Windhoek */
|
|
{"Nepal Standard Time", "Nepal Daylight Time", "Asia/Katmandu"}, /* (GMT+05:45) Kathmandu */
|
|
{"New Zealand Standard Time",
|
|
"New Zealand Daylight Time",
|
|
"Pacific/Auckland"}, /* (GMT+12:00) Auckland, Wellington */
|
|
{"Newfoundland Standard Time",
|
|
"Newfoundland Daylight Time",
|
|
"Canada/Newfoundland"}, /* (GMT-03:30) Newfoundland */
|
|
{"North Asia East Standard Time",
|
|
"North Asia East Daylight Time",
|
|
"Asia/Irkutsk"}, /* (GMT+08:00) Irkutsk, Ulaan Bataar */
|
|
{"North Asia Standard Time", "North Asia Daylight Time", "Asia/Krasnoyarsk"}, /* (GMT+07:00) Krasnoyarsk */
|
|
{"Pacific SA Standard Time", "Pacific SA Daylight Time", "America/Santiago"}, /* (GMT-04:00) Santiago */
|
|
{"Pacific Standard Time", "Pacific Daylight Time", "US/Pacific"}, /* (GMT-08:00) Pacific Time (US & Canada);
|
|
* Tijuana */
|
|
{"Pacific Standard Time (Mexico)",
|
|
"Pacific Daylight Time (Mexico)",
|
|
"America/Tijuana"}, /* (GMT-08:00) Tijuana, Baja California */
|
|
{"Pakistan Standard Time", "Pakistan Daylight Time", "Asia/Karachi"}, /* (GMT+05:00) Islamabad, Karachi */
|
|
{"Paraguay Standard Time", "Paraguay Daylight Time", "America/Asuncion"}, /* (GMT-04:00) Asuncion */
|
|
{"Romance Standard Time", "Romance Daylight Time", "Europe/Brussels"}, /* (GMT+01:00) Brussels, Copenhagen,
|
|
* Madrid, Paris */
|
|
{"Russian Standard Time", "Russian Daylight Time", "Europe/Moscow"}, /* (GMT+03:00) Moscow, St. Petersburg,
|
|
* Volgograd */
|
|
{"SA Eastern Standard Time",
|
|
"SA Eastern Daylight Time",
|
|
"America/Buenos_Aires"}, /* (GMT-03:00) Buenos Aires, Georgetown */
|
|
{"SA Pacific Standard Time",
|
|
"SA Pacific Daylight Time",
|
|
"America/Bogota"}, /* (GMT-05:00) Bogota, Lima, Quito */
|
|
{"SA Western Standard Time", "SA Western Daylight Time", "America/Caracas"}, /* (GMT-04:00) Caracas, La Paz */
|
|
{"Samoa Standard Time", "Samoa Daylight Time", "Pacific/Midway"}, /* (GMT-11:00) Midway Island, Samoa */
|
|
{"SE Asia Standard Time", "SE Asia Daylight Time", "Asia/Bangkok"}, /* (GMT+07:00) Bangkok, Hanoi, Jakarta */
|
|
{"Malay Peninsula Standard Time",
|
|
"Malay Peninsula Daylight Time",
|
|
"Asia/Kuala_Lumpur"}, /* (GMT+08:00) Kuala Lumpur, Singapore */
|
|
{"South Africa Standard Time",
|
|
"South Africa Daylight Time",
|
|
"Africa/Harare"}, /* (GMT+02:00) Harare, Pretoria */
|
|
{"Sri Lanka Standard Time", "Sri Lanka Daylight Time", "Asia/Colombo"}, /* (GMT+06:00) Sri Jayawardenepura */
|
|
{"Taipei Standard Time", "Taipei Daylight Time", "Asia/Taipei"}, /* (GMT+08:00) Taipei */
|
|
{"Tasmania Standard Time", "Tasmania Daylight Time", "Australia/Hobart"}, /* (GMT+10:00) Hobart */
|
|
{"Tokyo Standard Time", "Tokyo Daylight Time", "Asia/Tokyo"}, /* (GMT+09:00) Osaka, Sapporo, Tokyo */
|
|
{"Tonga Standard Time", "Tonga Daylight Time", "Pacific/Tongatapu"}, /* (GMT+13:00) Nuku'alofa */
|
|
{
|
|
"Ulaanbaatar Standard Time",
|
|
"Ulaanbaatar Daylight Time",
|
|
"Asia/Ulaanbaatar",
|
|
}, /* (GMT+08:00) Ulaanbaatar */
|
|
{"US Eastern Standard Time", "US Eastern Daylight Time", "US/Eastern"}, /* (GMT-05:00) Indiana (East) */
|
|
{"US Mountain Standard Time", "US Mountain Daylight Time", "US/Arizona"}, /* (GMT-07:00) Arizona */
|
|
{"Coordinated Universal Time", "Coordinated Universal Time", "UTC"}, /* (GMT) Coordinated Universal Time */
|
|
{"UTC+12", "UTC+12", "Etc/GMT+12"}, /* (GMT+12:00) Coordinated Universal Time+12 */
|
|
{"UTC-02", "UTC-02", "Etc/GMT-02"}, /* (GMT-02:00) Coordinated Universal Time-02 */
|
|
{"UTC-11", "UTC-11", "Etc/GMT-11"}, /* (GMT-11:00) Coordinated Universal Time-11 */
|
|
{
|
|
"Venezuela Standard Time",
|
|
"Venezuela Daylight Time",
|
|
"America/Caracas",
|
|
}, /* (GMT-04:30) Caracas */
|
|
{"Vladivostok Standard Time", "Vladivostok Daylight Time", "Asia/Vladivostok"}, /* (GMT+10:00) Vladivostok */
|
|
{"W. Australia Standard Time", "W. Australia Daylight Time", "Australia/Perth"}, /* (GMT+08:00) Perth */
|
|
#ifdef NOT_USED
|
|
/* Could not find a match for this one (just a guess). Excluded for now. */
|
|
{"W. Central Africa Standard Time",
|
|
"W. Central Africa Daylight Time",
|
|
"WAT"}, /* (GMT+01:00) West Central Africa */
|
|
#endif
|
|
{"W. Europe Standard Time", "W. Europe Daylight Time", "CET"}, /* (GMT+01:00) Amsterdam, Berlin, Bern, Rome,
|
|
* Stockholm, Vienna */
|
|
{"West Asia Standard Time",
|
|
"West Asia Daylight Time",
|
|
"Asia/Karachi"}, /* (GMT+05:00) Islamabad, Karachi, Tashkent */
|
|
{"West Pacific Standard Time",
|
|
"West Pacific Daylight Time",
|
|
"Pacific/Guam"}, /* (GMT+10:00) Guam, Port Moresby */
|
|
{"Yakutsk Standard Time", "Yakutsk Daylight Time", "Asia/Yakutsk"}, /* (GMT+09:00) Yakutsk */
|
|
{NULL, NULL, NULL}};
|
|
|
|
const char* identify_system_timezone(void)
|
|
{
|
|
int i;
|
|
char tzname[TZNAME_LENGTH];
|
|
char localtzname[LOCAL_TZNAME_LENGTH];
|
|
time_t t = time(NULL);
|
|
struct tm* tm = localtime(&t);
|
|
HKEY rootKey = NULL;
|
|
int idx;
|
|
errno_t rc = 0;
|
|
|
|
if (tm == NULL) {
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr("could not identify system time zone: localtime() failed\n");
|
|
#endif
|
|
return NULL; /* go to GMT */
|
|
}
|
|
|
|
rc = memset_s(tzname, TZNAME_LENGTH, 0, sizeof(tzname));
|
|
securec_check_c(rc, "\0", "\0");
|
|
(void)strftime(tzname, sizeof(tzname) - 1, "%Z", tm);
|
|
|
|
for (i = 0; win32_tzmap[i].stdname != NULL; i++) {
|
|
if (strcmp(tzname, win32_tzmap[i].stdname) == 0 || strcmp(tzname, win32_tzmap[i].dstname) == 0) {
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr("TZ \"%s\" matches system time zone \"%s\"\n", win32_tzmap[i].pgtzname, tzname);
|
|
#endif
|
|
return win32_tzmap[i].pgtzname;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Localized Windows versions return localized names for the timezone.
|
|
* Scan the registry to find the English name, and then try matching
|
|
* against our table again.
|
|
*/
|
|
rc = memset_s(localtzname, LOCAL_TZNAME_LENGTH, 0, sizeof(localtzname));
|
|
securec_check_c(rc, "\0", "\0");
|
|
if (RegOpenKeyEx(
|
|
HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Time Zones", 0, KEY_READ, &rootKey) !=
|
|
ERROR_SUCCESS) {
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr("could not open registry key to identify system time zone: error code %lu\n", GetLastError());
|
|
#endif
|
|
return NULL; /* go to GMT */
|
|
}
|
|
|
|
for (idx = 0;; idx++) {
|
|
char keyname[LOCAL_TZNAME_LENGTH];
|
|
char zonename[LOCAL_TZNAME_LENGTH];
|
|
DWORD namesize;
|
|
FILETIME lastwrite;
|
|
HKEY key = NULL;
|
|
LONG r;
|
|
|
|
rc = memset_s(keyname, LOCAL_TZNAME_LENGTH, 0, sizeof(keyname));
|
|
securec_check_c(rc, "\0", "\0");
|
|
namesize = sizeof(keyname);
|
|
if ((r = RegEnumKeyEx(rootKey, idx, keyname, &namesize, NULL, NULL, NULL, &lastwrite)) != ERROR_SUCCESS) {
|
|
if (r == ERROR_NO_MORE_ITEMS)
|
|
break;
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr("could not enumerate registry subkeys to identify system time zone: %d\n", (int)r);
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
if ((r = RegOpenKeyEx(rootKey, keyname, 0, KEY_READ, &key)) != ERROR_SUCCESS) {
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr("could not open registry subkey to identify system time zone: %d\n", (int)r);
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
rc = memset_s(zonename, LOCAL_TZNAME_LENGTH, 0, sizeof(zonename));
|
|
securec_check_c(rc, "\0", "\0");
|
|
namesize = sizeof(zonename);
|
|
if ((r = RegQueryValueEx(key, "Std", NULL, NULL, (unsigned char*)zonename, &namesize)) != ERROR_SUCCESS) {
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr(
|
|
"could not query value for key \"std\" to identify system time zone \"%s\": %d\n", keyname, (int)r);
|
|
#endif
|
|
RegCloseKey(key);
|
|
continue; /* Proceed to look at the next timezone */
|
|
}
|
|
if (strcmp(tzname, zonename) == 0) {
|
|
/* Matched zone */
|
|
rc = strcpy_s(localtzname, LOCAL_TZNAME_LENGTH, keyname);
|
|
securec_check_c(rc, "\0", "\0");
|
|
RegCloseKey(key);
|
|
break;
|
|
}
|
|
rc = memset_s(zonename, LOCAL_TZNAME_LENGTH, 0, sizeof(zonename));
|
|
securec_check_c(rc, "\0", "\0");
|
|
namesize = sizeof(zonename);
|
|
if ((r = RegQueryValueEx(key, "Dlt", NULL, NULL, (unsigned char*)zonename, &namesize)) != ERROR_SUCCESS) {
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr(
|
|
"could not query value for key \"dlt\" to identify system time zone \"%s\": %d\n", keyname, (int)r);
|
|
#endif
|
|
RegCloseKey(key);
|
|
continue; /* Proceed to look at the next timezone */
|
|
}
|
|
if (strcmp(tzname, zonename) == 0) {
|
|
/* Matched DST zone */
|
|
rc = strcpy_s(localtzname, LOCAL_TZNAME_LENGTH, keyname);
|
|
securec_check_c(rc, "\0", "\0");
|
|
RegCloseKey(key);
|
|
break;
|
|
}
|
|
|
|
RegCloseKey(key);
|
|
}
|
|
|
|
RegCloseKey(rootKey);
|
|
|
|
if (localtzname[0]) {
|
|
/* Found a localized name, so scan for that one too */
|
|
for (i = 0; win32_tzmap[i].stdname != NULL; i++) {
|
|
if (strcmp(localtzname, win32_tzmap[i].stdname) == 0 || strcmp(localtzname, win32_tzmap[i].dstname) == 0) {
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr("TZ \"%s\" matches localized system time zone \"%s\" (\"%s\")\n",
|
|
win32_tzmap[i].pgtzname,
|
|
tzname,
|
|
localtzname);
|
|
#endif
|
|
return win32_tzmap[i].pgtzname;
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef DEBUG_IDENTIFY_TIMEZONE
|
|
write_stderr("could not find a match for system time zone \"%s\"\n", tzname);
|
|
#endif
|
|
return NULL; /* go to GMT */
|
|
}
|
|
#endif /* WIN32 */
|
|
|
|
/*
|
|
* Return true if the given zone name is valid and is an "acceptable" zone.
|
|
*/
|
|
static bool validate_zone(const char* tz_name)
|
|
{
|
|
pg_tz* tz = NULL;
|
|
|
|
if ((tz_name == NULL) || !tz_name[0]) {
|
|
return false;
|
|
}
|
|
|
|
tz = pg_load_tz(tz_name);
|
|
if (tz == NULL) {
|
|
return false;
|
|
}
|
|
|
|
if (!pg_tz_acceptable(tz)) {
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Identify a suitable default timezone setting based on the environment.
|
|
*
|
|
* The installation share_path must be passed in, as that is the default
|
|
* location for the timezone database directory.
|
|
*
|
|
* We first look to the TZ environment variable. If not found or not
|
|
* recognized by our own code, we see if we can identify the timezone
|
|
* from the behavior of the system timezone library. When all else fails,
|
|
* return NULL, indicating that we should default to GMT.
|
|
*/
|
|
const char* select_default_timezone(const char* share_path)
|
|
{
|
|
const char* tz_name = NULL;
|
|
int nRet = 0;
|
|
|
|
/* Initialize timezone directory path, if needed */
|
|
#ifndef SYSTEMTZDIR
|
|
nRet = snprintf_s(tzdirpath, sizeof(tzdirpath), sizeof(tzdirpath) - 1, "%s/timezone", share_path);
|
|
securec_check_ss_c(nRet, "\0", "\0");
|
|
#endif
|
|
|
|
/* Check TZ environment variable */
|
|
tz_name = getenv("TZ");
|
|
if (validate_zone(tz_name))
|
|
return tz_name;
|
|
|
|
/* Nope, so try to identify the system timezone */
|
|
tz_name = identify_system_timezone();
|
|
if (validate_zone(tz_name))
|
|
return tz_name;
|
|
|
|
return NULL;
|
|
}
|