/* ------------------------------------------------------------------------- * * findtimezone.c * Functions for determining the default timezone to use. * * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group * * IDENTIFICATION * src/bin/initdb/findtimezone.c * * ------------------------------------------------------------------------- */ #include "postgres_fe.h" #include #include #include "pgtz.h" #include "bin/elog.h" #define TZNAME_LENGTH 128 #define LOCAL_TZNAME_LENGTH 256 /* Ideally this would be in a .h file, but it hardly seems worth the trouble */ extern const char* select_default_timezone(const char* share_path); #ifndef SYSTEMTZDIR static char tzdirpath[MAXPGPATH]; #endif #ifndef ERROR_LIMIT_LEN #define ERROR_LIMIT_LEN 256 #endif /* * Return full pathname of timezone data directory * * In this file, tzdirpath is assumed to be set up by select_default_timezone. */ static const char* pg_TZDIR(void) { #ifndef SYSTEMTZDIR /* normal case: timezone stuff is under our share dir */ return tzdirpath; #else /* we're configured to use system's timezone database */ return SYSTEMTZDIR; #endif } /* * Given a timezone name, open() the timezone data file. Return the * file descriptor if successful, -1 if not. * * This is simpler than the backend function of the same name because * we assume that the input string has the correct case already, so there * is no need for case-folding. (This is obviously true if we got the file * name from the filesystem to start with. The only other place it can come * from is the environment variable TZ, and there seems no need to allow * case variation in that; other programs aren't likely to.) * * If "canonname" is not NULL, then on success the canonical spelling of the * given name is stored there (the buffer must be > TZ_STRLEN_MAX bytes!). * This is redundant but kept for compatibility with the backend code. */ int pg_open_tzfile(const char* name, char* canonname) { char fullname[MAXPGPATH]; errno_t rc = 0; if (canonname != NULL) { rc = strncpy_s(canonname, TZ_STRLEN_MAX + 1, name, TZ_STRLEN_MAX); securec_check_c(rc, "\0", "\0"); } rc = strcpy_s(fullname, MAXPGPATH, pg_TZDIR()); securec_check_c(rc, "\0", "\0"); if (strlen(fullname) + 1 + strlen(name) >= MAXPGPATH) return -1; /* not gonna fit */ rc = strcat_s(fullname, MAXPGPATH, "/"); securec_check_c(rc, "\0", "\0"); rc = strcat_s(fullname, MAXPGPATH, name); securec_check_c(rc, "\0", "\0"); return open(fullname, O_RDONLY | PG_BINARY, 0); } /* * Load a timezone definition. * Does not verify that the timezone is acceptable! * * This corresponds to the backend's pg_tzset(), except that we only support * one loaded timezone at a time. */ static pg_tz* pg_load_tz(const char* name) { static pg_tz tz; errno_t rc = 0; if (strlen(name) > TZ_STRLEN_MAX) return NULL; /* not going to fit */ /* * "GMT" is always sent to tzparse(); see comments for pg_tzset(). */ if (strcmp(name, "GMT") == 0) { if (tzparse(name, &tz.state, TRUE) != 0) { /* This really, really should not happen ... */ return NULL; } } else if (tzload(name, NULL, &tz.state, TRUE) != 0) { if (name[0] == ':' || tzparse(name, &tz.state, FALSE) != 0) { return NULL; /* unknown timezone */ } } rc = strcpy_s(tz.TZname, (TZ_STRLEN_MAX + 1), name); securec_check_c(rc, "\0", "\0"); return &tz; } /* * The following block of code attempts to determine which timezone in our * timezone database is the best match for the active system timezone. * * On most systems, we rely on trying to match the observable behavior of * the C library's localtime() function. The database zone that matches * furthest into the past is the one to use. Often there will be several * zones with identical rankings (since the Olson database assigns multiple * names to many zones). We break ties arbitrarily by preferring shorter, * then alphabetically earlier zone names. * * Win32's native knowledge about timezones appears to be too incomplete * and too different from the Olson database for the above matching strategy * to be of any use. But there is just a limited number of timezones * available, so we can rely on a handmade mapping table instead. */ #ifndef WIN32 #define T_DAY ((time_t)(60 * 60 * 24)) #define T_WEEK ((time_t)(60 * 60 * 24 * 7)) #define T_MONTH ((time_t)(60 * 60 * 24 * 31)) #define MAX_TEST_TIMES (52 * 100) /* 100 years */ struct tztry { int n_test_times; time_t test_times[MAX_TEST_TIMES]; }; /* * Get GMT offset from a system struct tm */ static int get_timezone_offset(struct tm* tm_val) { #if defined(HAVE_STRUCT_TM_TM_ZONE) return tm_val->tm_gmtoff; #elif defined(HAVE_INT_TIMEZONE) return -TIMEZONE_GLOBAL; #else #error No way to determine TZ? Can this happen? #endif } /* * Convenience subroutine to convert y/m/d to time_t (NOT pg_time_t) */ static time_t build_time_t(int year, int month, int day) { struct tm tm_val; errno_t rc = 0; rc = memset_s(&tm_val, sizeof(tm_val), 0, sizeof(tm_val)); securec_check_c(rc, "\0", "\0"); tm_val.tm_mday = day; tm_val.tm_mon = month - 1; tm_val.tm_year = year - 1900; return mktime(&tm_val); } /* * Does a system tm value match one we computed ourselves? */ static bool compare_tm(struct tm* s, struct pg_tm* p) { 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 || s->tm_mon != p->tm_mon || s->tm_year != p->tm_year || s->tm_wday != p->tm_wday || s->tm_yday != p->tm_yday || s->tm_isdst != p->tm_isdst) return false; return true; } /* * See how well a specific timezone setting matches the system behavior * * We score a timezone setting according to the number of test times it * matches. (The test times are ordered later-to-earlier, but this routine * doesn't actually know that; it just scans until the first non-match.) * * We return -1 for a completely unusable setting; this is worse than the * score of zero for a setting that works but matches not even the first * test time. */ static int score_timezone(const char* tz_name, struct tztry* tt) { int i; pg_time_t pgtt; struct tm* systm = NULL; struct pg_tm* pgtm = NULL; char cbuf[TZ_STRLEN_MAX + 1]; pg_tz* tz = NULL; errno_t rc = 0; /* Load timezone definition */ tz = pg_load_tz(tz_name); if (tz == NULL) return -1; /* unrecognized zone name */ /* Reject if leap seconds involved */ if (!pg_tz_acceptable(tz)) { #ifdef DEBUG_IDENTIFY_TIMEZONE write_stderr("Reject TZ \"%s\": uses leap seconds\n", tz_name); #endif return -1; } /* Check for match at all the test times */ for (i = 0; i < tt->n_test_times; i++) { pgtt = (pg_time_t)(tt->test_times[i]); pgtm = pg_localtime(&pgtt, tz); if (pgtm == NULL) { return -1; /* probably shouldn't happen */ } systm = localtime(&(tt->test_times[i])); if (systm == NULL) { #ifdef DEBUG_IDENTIFY_TIMEZONE write_stderr("TZ \"%s\" scores %d: at %ld %04d-%02d-%02d %02d:%02d:%02d %s, system had no data\n", tz_name, i, (long)pgtt, pgtm->tm_year + 1900, pgtm->tm_mon + 1, pgtm->tm_mday, pgtm->tm_hour, pgtm->tm_min, pgtm->tm_sec, pgtm->tm_isdst ? "dst" : "std"); #endif return i; } if (!compare_tm(systm, pgtm)) { #ifdef DEBUG_IDENTIFY_TIMEZONE write_stderr("TZ \"%s\" scores %d: at %ld %04d-%02d-%02d %02d:%02d:%02d %s versus %04d-%02d-%02d " "%02d:%02d:%02d %s\n", tz_name, i, (long)pgtt, pgtm->tm_year + 1900, pgtm->tm_mon + 1, pgtm->tm_mday, pgtm->tm_hour, pgtm->tm_min, pgtm->tm_sec, pgtm->tm_isdst ? "dst" : "std", systm->tm_year + 1900, systm->tm_mon + 1, systm->tm_mday, systm->tm_hour, systm->tm_min, systm->tm_sec, systm->tm_isdst ? "dst" : "std"); #endif return i; } if (systm->tm_isdst >= 0) { /* Check match of zone names, too */ if (pgtm->tm_zone == NULL) return -1; /* probably shouldn't happen */ rc = memset_s(cbuf, (TZ_STRLEN_MAX + 1), 0, sizeof(cbuf)); securec_check_c(rc, "\0", "\0"); (void)strftime(cbuf, sizeof(cbuf) - 1, "%Z", systm); /* zone abbr */ if (strcmp(cbuf, pgtm->tm_zone) != 0) { #ifdef DEBUG_IDENTIFY_TIMEZONE write_stderr( "TZ \"%s\" scores %d: at %ld \"%s\" versus \"%s\"\n", tz_name, i, (long)pgtt, pgtm->tm_zone, cbuf); #endif return i; } } } #ifdef DEBUG_IDENTIFY_TIMEZONE write_stderr("TZ \"%s\" gets max score %d\n", tz_name, i); #endif return i; } /* * Try to identify a timezone name (in our terminology) that best matches the * observed behavior of the system timezone library. We cannot assume that * the system TZ environment setting (if indeed there is one) matches our * terminology, so we ignore it and just look at what localtime() returns. */ const char* identify_system_timezone(void) { static char resultbuf[TZ_STRLEN_MAX + 1]; time_t tnow; time_t t; struct tztry tt = {0}; struct tm* tm_val = NULL; int thisyear; int bestscore; char tmptzdir[MAXPGPATH]; int std_ofs; char std_zone_name[TZ_STRLEN_MAX + 1], dst_zone_name[TZ_STRLEN_MAX + 1]; char cbuf[TZ_STRLEN_MAX + 1]; errno_t rc = 0; int nRet = 0; /* Initialize OS timezone library */ tzset(); /* * Set up the list of dates to be probed to see how well our timezone * matches the system zone. We first probe January and July of the * current year; this serves to quickly eliminate the vast majority of the * TZ database entries. If those dates match, we probe every week for 100 * years backwards from the current July. (Weekly resolution is good * enough to identify DST transition rules, since everybody switches on * Sundays.) This is sufficient to cover most of the Unix time_t range, * and we don't want to look further than that since many systems won't * have sane TZ behavior further back anyway. The further back the zone * matches, the better we score it. This may seem like a rather random * way of doing things, but experience has shown that system-supplied * timezone definitions are likely to have DST behavior that is right for * the recent past and not so accurate further back. Scoring in this way * allows us to recognize zones that have some commonality with the Olson * database, without insisting on exact match. (Note: we probe Thursdays, * not Sundays, to avoid triggering DST-transition bugs in localtime * itself.) */ tnow = time(NULL); tm_val = localtime(&tnow); if (tm_val == NULL) { return NULL; /* give up if localtime is broken... */ } thisyear = tm_val->tm_year + 1900; t = build_time_t(thisyear, 1, 15); /* * Round back to GMT midnight Thursday. This depends on the knowledge * that the time_t origin is Thu Jan 01 1970. (With a different origin * we'd be probing some other day of the week, but it wouldn't matter * anyway unless localtime() had DST-transition bugs.) */ t -= (t % T_WEEK); tt.n_test_times = 0; tt.test_times[tt.n_test_times++] = t; t = build_time_t(thisyear, 7, 15); t -= (t % T_WEEK); tt.test_times[tt.n_test_times++] = t; while (tt.n_test_times < MAX_TEST_TIMES) { t -= T_WEEK; tt.test_times[tt.n_test_times++] = t; } /* Search for the best-matching timezone file */ rc = strncpy_s(tmptzdir, MAXPGPATH, pg_TZDIR(), MAXPGPATH - 1); securec_check_c(rc, "\0", "\0"); bestscore = -1; resultbuf[0] = '\0'; scan_available_timezones(tmptzdir, tmptzdir + strlen(tmptzdir) + 1, &tt, &bestscore, resultbuf); if (bestscore > 0) { /* Ignore Olson's rather silly "Factory" zone; use GMT instead */ if (strcmp(resultbuf, "Factory") == 0) return NULL; return resultbuf; } /* * Couldn't find a match in the database, so next we try constructed zone * names (like "PST8PDT"). * * First we need to determine the names of the local standard and daylight * zones. The idea here is to scan forward from today until we have seen * both zones, if both are in use. */ rc = memset_s(std_zone_name, (TZ_STRLEN_MAX + 1), 0, sizeof(std_zone_name)); securec_check_c(rc, "\0", "\0"); rc = memset_s(dst_zone_name, (TZ_STRLEN_MAX + 1), 0, sizeof(dst_zone_name)); securec_check_c(rc, "\0", "\0"); std_ofs = 0; tnow = time(NULL); /* * Round back to a GMT midnight so results don't depend on local time of * day */ tnow -= (tnow % T_DAY); /* * We have to look a little further ahead than one year, in case today is * just past a DST boundary that falls earlier in the year than the next * similar boundary. Arbitrarily scan up to 14 months. */ for (t = tnow; t <= tnow + T_MONTH * 14; t += T_MONTH) { tm_val = localtime(&t); if (tm_val == NULL) { continue; } if (tm_val->tm_isdst < 0) { continue; } if (tm_val->tm_isdst == 0 && std_zone_name[0] == '\0') { /* found STD zone */ rc = memset_s(cbuf, (TZ_STRLEN_MAX + 1), 0, sizeof(cbuf)); securec_check_c(rc, "\0", "\0"); (void)strftime(cbuf, sizeof(cbuf) - 1, "%Z", tm_val); /* zone abbr */ rc = strcpy_s(std_zone_name, (TZ_STRLEN_MAX + 1), cbuf); securec_check_c(rc, "\0", "\0"); std_ofs = get_timezone_offset(tm_val); } if (tm_val->tm_isdst > 0 && dst_zone_name[0] == '\0') { /* found DST zone */ rc = memset_s(cbuf, (TZ_STRLEN_MAX + 1), 0, sizeof(cbuf)); securec_check_c(rc, "\0", "\0"); (void)strftime(cbuf, sizeof(cbuf) - 1, "%Z", tm_val); /* zone abbr */ rc = strcpy_s(dst_zone_name, (TZ_STRLEN_MAX + 1), cbuf); securec_check_c(rc, "\0", "\0"); } /* Done if found both */ if (std_zone_name[0] && dst_zone_name[0]) break; } /* We should have found a STD zone name by now... */ if (std_zone_name[0] == '\0') { #ifdef DEBUG_IDENTIFY_TIMEZONE write_stderr("could not determine system time zone\n"); #endif return NULL; /* go to GMT */ } /* If we found DST then try STDDST */ if (dst_zone_name[0] != '\0') { nRet = snprintf_s(resultbuf, sizeof(resultbuf), sizeof(resultbuf) - 1, "%s%d%s", std_zone_name, -std_ofs / 3600, dst_zone_name); securec_check_ss_c(nRet, "\0", "\0"); if (score_timezone(resultbuf, &tt) > 0) return resultbuf; } /* Try just the STD timezone (works for GMT at least) */ rc = strcpy_s(resultbuf, (TZ_STRLEN_MAX + 1), std_zone_name); securec_check_c(rc, "\0", "\0"); if (score_timezone(resultbuf, &tt) > 0) return resultbuf; /* Try STD */ 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; }