/**************************************************************************** * libs/libc/time/lib_localtime.c * * Re-released as part of NuttX under the 3-clause BSD license: * * Copyright (C) 2014 Gregory Nutt. All rights reserved. * Ported to NuttX by Max Neklyudov * Style updates by Gregory Nutt * * With these notes: * * This file is in the public domain, so clarified as of * 1996-06-05 by Arthur David Olson. * * Leap second handling from Bradley White. * POSIX-style TZ environment variable handling from Guy Harris. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include "libc.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Configuration ************************************************************/ /* Time zone object file directory */ #ifdef CONFIG_LIBC_TZDIR # define TZDIR CONFIG_LIBC_TZDIR #else # define TZDIR "/etc/zoneinfo" #endif /* Time definitions *********************************************************/ /* Time zone files */ #define TZ_MAGIC "TZif" #define TZDEFAULT "localtime" #define TZDEFRULES "posixrules" /* In the current implementation, "tzset()" refuses to deal with files that * exceed any of the limits below. */ #define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */ #define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */ #define SECSPERMIN 60 #define MINSPERHOUR 60 #define HOURSPERDAY 24 #define DAYSPERWEEK 7 #define DAYSPERNYEAR 365 #define DAYSPERLYEAR 366 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) #define SECSPERDAY ((int_fast32_t)SECSPERHOUR * HOURSPERDAY) #define MONSPERYEAR 12 #define TM_SUNDAY 0 #define TM_MONDAY 1 #define TM_TUESDAY 2 #define TM_WEDNESDAY 3 #define TM_THURSDAY 4 #define TM_FRIDAY 5 #define TM_SATURDAY 6 #define TM_JANUARY 0 #define TM_FEBRUARY 1 #define TM_MARCH 2 #define TM_APRIL 3 #define TM_MAY 4 #define TM_JUNE 5 #define TM_JULY 6 #define TM_AUGUST 7 #define TM_SEPTEMBER 8 #define TM_OCTOBER 9 #define TM_NOVEMBER 10 #define TM_DECEMBER 11 #define TM_YEAR_BASE 1900 #define EPOCH_YEAR 1970 #define EPOCH_WDAY TM_THURSDAY #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0)) /* Since everything in isleap is modulo 400 (or a factor of 400), we know * that * isleap(y) == isleap(y % 400) * and so * isleap(a + b) == isleap((a + b) % 400) * or * isleap(a + b) == isleap(a % 400 + b % 400) * * This is true even if % means modulo rather than Fortran remainder (which * is allowed by C89 but not C99). We use this to avoid addition overflow * problems. */ #define isleap_sum(a, b) isleap((a) % 400 + (b) % 400) #define GRANDPARENTED "Local time zone must be set--see zic manual page" #define TYPE_BIT(type) (sizeof(type) * CHAR_BIT) #define TYPE_SIGNED(type) (((type)-1) < 0) #define YEARSPERREPEAT 400 /* years before a Gregorian repeat */ /* The Gregorian year averages 365.2425 days, which is 31556952 seconds. */ #define AVGSECSPERYEAR 31556952L #define SECSPERREPEAT ((int_fast64_t)YEARSPERREPEAT * (int_fast64_t)AVGSECSPERYEAR) #define SECSPERREPEAT_BITS 34 /* ceil(log2(SECSPERREPEAT)) */ #define TZ_ABBR_MAX_LEN 16 #define TZ_ABBR_CHAR_SET \ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" #define TZ_ABBR_ERR_CHAR '_' /* Unlike 's isdigit, this also works if c < 0 | c > UCHAR_MAX. */ #define is_digit(c) ((unsigned)(c) - '0' <= 9) #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) #define MY_TZNAME_MAX 255 #define GMT "GMT" #define GMTLEN 3 #define JULIAN_DAY 0 /* Jn = Julian day */ #define DAY_OF_YEAR 1 /* n = day of year */ #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d = month, week, day of week */ /* Someone might make incorrect use of a time zone abbreviation: * 1. They might reference tzname[0] before calling tzset (explicitly * or implicitly). * 2. They might reference tzname[1] before calling tzset (explicitly * or implicitly). * 3. They might reference tzname[1] after setting to a time zone * in which Daylight Saving Time is never observed. * 4. They might reference tzname[0] after setting to a time zone * in which Standard Time is never observed. * * What's best to do in the above cases is open to debate; * for now, we just set things up so that in any of the five cases * WILDABBR is used. Another possibility: initialize tzname[0] to the * string "tzname[0] used before set", and similarly for the other cases. * And another: initialize tzname[0] to "ERA", with an explanation in the * manual page of what this "time zone abbreviation" means (doing this so * that tzname[0] has the "normal" length of three characters). */ #define WILDABBR " " /* The DST rules to use if TZ has no rules and we can't load TZDEFRULES. * We default to US rules as of 1999-08-17. * POSIX 1003.1 section 8.1.1 says that the default DST rules are * implementation dependent; for historical reasons, US rules are a * common default. */ #define TZDEFRULESTRING ",M3.2.0,M11.1.0" /**************************************************************************** * Private Types ****************************************************************************/ /* Time file file header. * Each time zone file begins with a time zone header followed by: * * tzh_timecnt (char [4])s coded transition times a la time(2) * tzh_timecnt (unsigned char)s types of local time starting at above * tzh_typecnt repetitions of * one (char [4]) coded UT offset in seconds * one (unsigned char) used to set tm_isdst * one (unsigned char) that's an abbreviation list index * tzh_charcnt (char)s '\0'-terminated zone abbreviations * tzh_leapcnt repetitions of * one (char [4]) coded leap second transition times * one (char [4]) total correction after above * tzh_ttisstdcnt (char)s indexed by type; if TRUE, transition * time is standard time, if FALSE, * transition time is wall clock time * if absent, transition times are * assumed to be wall clock time * tzh_ttisgmtcnt (char)s indexed by type; if TRUE, transition * time is UT, if FALSE, * transition time is local time * if absent, transition times are * assumed to be local time * * If tzh_version is '2' or greater, the above is followed by a second * instance of tzhead_s and a second instance of the data in which each * coded transition time uses 8 rather than 4 chars, then a * POSIX-TZ-environment-variable-style string for use in handling instants * after the last transition time stored in the file (with nothing between * the newlines if there is no POSIX representation for such instants). * * If tz_version is '3' or greater, the above is extended as follows. * First, the POSIX TZ string's hour offset may range from -167 through * 167 as compared to the POSIX-required 0 through 24. Second, its DST * start time may be January 1 at 00:00 and its stop time December 31 at * 24:00 plus the difference between DST and standard time, indicating DST * all year. */ struct tzhead_s { char tzh_magic[4]; /* TZ_MAGIC */ char tzh_version[1]; /* '\0' or '2' or '3' as of 2013 */ char tzh_reserved[15]; /* reserved; must be zero */ char tzh_ttisgmtcnt[4]; /* coded number of trans. time flags */ char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */ char tzh_leapcnt[4]; /* coded number of leap seconds */ char tzh_timecnt[4]; /* coded number of transition times */ char tzh_typecnt[4]; /* coded number of local time types */ char tzh_charcnt[4]; /* coded number of abbr. chars */ }; struct ttinfo_s { /* Time type information */ int_fast32_t tt_gmtoff; /* UT offset in seconds */ int tt_isdst; /* Used to set tm_isdst */ int tt_abbrind; /* Abbreviation list index */ int tt_ttisstd; /* True if transition is std time */ int tt_ttisgmt; /* True if transition is UT */ }; struct lsinfo_s { /* Leap second information */ time_t ls_trans; /* Transition time */ int_fast32_t ls_corr; /* Correction to apply */ }; struct state_s { int leapcnt; int timecnt; int typecnt; int charcnt; int goback; int goahead; time_t ats[TZ_MAX_TIMES]; unsigned char types[TZ_MAX_TIMES]; struct ttinfo_s ttis[TZ_MAX_TYPES]; char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, GMTLEN), (2 * (MY_TZNAME_MAX + 1)))]; struct lsinfo_s lsis[TZ_MAX_LEAPS]; int defaulttype; /* For early times or if no transitions */ }; struct rule_s { int r_type; /* type of rule; see below */ int r_day; /* day number of rule */ int r_week; /* week number of rule */ int r_mon; /* month number of rule */ int_fast32_t r_time; /* transition time of rule */ }; /**************************************************************************** * Private Data ****************************************************************************/ /* The minimum and maximum finite time values. */ static const time_t g_min_timet = (TYPE_SIGNED(time_t) ? (time_t)-1 << (CHAR_BIT * sizeof(time_t) - 1) : 0); static const time_t g_max_timet = (TYPE_SIGNED(time_t) ? - (~ 0 < 0) - ((time_t)-1 << (CHAR_BIT * sizeof(time_t) - 1)) : -1); static const char g_wildabbr[] = WILDABBR; static char g_lcl_tzname[MY_TZNAME_MAX + 1]; static int g_lcl_isset; static int g_gmt_isset; static FAR struct state_s *g_lcl_ptr; static FAR struct state_s *g_gmt_ptr; static sem_t g_lcl_sem = SEM_INITIALIZER(1); static sem_t g_gmt_sem = SEM_INITIALIZER(1); /* Section 4.12.3 of X3.159-1989 requires that * Except for the strftime function, these functions [asctime, * ctime, gmtime, localtime] return values in one of two static * objects: a broken-down time structure and an array of char. * Thanks to Paul Eggert for noting this. */ static struct tm g_tm; static const int g_mon_lengths[2][MONSPERYEAR] = { {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31} }; static const int g_year_lengths[2] = { DAYSPERNYEAR, DAYSPERLYEAR }; /**************************************************************************** * Public Data ****************************************************************************/ /* Setup by tzset() */ FAR char *tzname[2] = { (FAR char *)g_wildabbr, (FAR char *)g_wildabbr }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static int_fast32_t detzcode(FAR const char *codep); static int_fast64_t detzcode64(FAR const char *codep); static int differ_by_repeat(time_t t1, time_t t0); static FAR const char *getzname(FAR const char *strp); static FAR const char *getqzname(FAR const char *strp, int delim); static FAR const char *getnum(FAR const char *strp, FAR int *nump, int min, int max); static FAR const char *getsecs(FAR const char *strp, FAR int_fast32_t *secsp); static FAR const char *getoffset(FAR const char *strp, FAR int_fast32_t *offsetp); static FAR const char *getrule(FAR const char *strp, FAR struct rule_s *rulep); static void gmtload(FAR struct state_s *sp); static FAR struct tm *gmtsub(FAR const time_t *timep, int_fast32_t offset, FAR struct tm *tmp); static FAR struct tm *localsub(FAR const time_t *timep, int_fast32_t offset, FAR struct tm *tmp); static int increment_overflow(FAR int *number, int delta); static int leaps_thru_end_of(int y); static int increment_overflow32(FAR int_fast32_t *number, int delta); static int increment_overflow_time(FAR time_t *t, int_fast32_t delta); static int normalize_overflow32(FAR int_fast32_t *tensptr, FAR int *unitsptr, int base); static int normalize_overflow(FAR int *tensptr, FAR int *unitsptr, int base); static void settzname(void); static time_t time1(FAR struct tm *tmp, FAR struct tm *(*funcp)(FAR const time_t *, int_fast32_t, FAR struct tm *), int_fast32_t offset); static time_t time2(FAR struct tm *tmp, FAR struct tm *(*funcp)(FAR const time_t *, int_fast32_t, FAR struct tm *), int_fast32_t offset, FAR int *okayp); static time_t time2sub(FAR struct tm *tmp, FAR struct tm *(*funcp)(FAR const time_t *, int_fast32_t, FAR struct tm *), int_fast32_t offset, FAR int *okayp, int do_norm_secs); static FAR struct tm *timesub(FAR const time_t *timep, int_fast32_t offset, FAR const struct state_s *sp, FAR struct tm *tmp); static int tmcomp(FAR const struct tm *atmp, FAR const struct tm *btmp); static int_fast32_t transtime(int year, FAR const struct rule_s *rulep, int_fast32_t offset); static int typesequiv(FAR const struct state_s *sp, int a, int b); static int tzload(FAR const char *name, FAR struct state_s *sp, int doextend); static int tzparse(FAR const char *name, FAR struct state_s *sp, int lastditch); /**************************************************************************** * Private Functions ****************************************************************************/ static void tz_semtake(FAR sem_t *sem) { int errcode = 0; int ret; do { ret = _SEM_WAIT(sem); if (ret < 0) { errcode = _SEM_ERRNO(ret); DEBUGASSERT(errcode == EINTR || errcode == ECANCELED); } } while (ret < 0 && errcode == EINTR); } static void tz_semgive(FAR sem_t *sem) { DEBUGVERIFY(_SEM_POST(sem)); } static int_fast32_t detzcode(FAR const char *codep) { int_fast32_t result; int i; result = (codep[0] & 0x80) ? -1 : 0; for (i = 0; i < 4; ++i) { result = (result << 8) | (codep[i] & 0xff); } return result; } static int_fast64_t detzcode64(FAR const char *codep) { int_fast64_t result; int i; result = (codep[0] & 0x80) ? -1 : 0; for (i = 0; i < 8; ++i) { result = (result << 8) | (codep[i] & 0xff); } return result; } static void settzname(void) { FAR struct state_s *const sp = g_lcl_ptr; int i; tzname[0] = tzname[1] = (FAR char *)g_wildabbr; if (sp == NULL) { tzname[0] = tzname[1] = (FAR char *)GMT; return; } /* And to get the latest zone names into tzname */ for (i = 0; i < sp->typecnt; ++i) { FAR const struct ttinfo_s *const ttisp = &sp->ttis[i]; tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; } for (i = 0; i < sp->timecnt; ++i) { FAR const struct ttinfo_s *const ttisp = &sp->ttis[sp->types[i]]; tzname[ttisp->tt_isdst] = &sp->chars[ttisp->tt_abbrind]; } /* Finally, scrub the abbreviations. First, replace bogus characters. */ for (i = 0; i < sp->charcnt; ++i) { if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL) { sp->chars[i] = TZ_ABBR_ERR_CHAR; } } /* Second, truncate long abbreviations. */ for (i = 0; i < sp->typecnt; ++i) { FAR const struct ttinfo_s *const ttisp = &sp->ttis[i]; FAR char *cp = &sp->chars[ttisp->tt_abbrind]; if (strlen(cp) > TZ_ABBR_MAX_LEN && strcmp(cp, GRANDPARENTED) != 0) { *(cp + TZ_ABBR_MAX_LEN) = '\0'; } } } static int differ_by_repeat(time_t t1, time_t t0) { if (TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS) { return 0; } return t1 - t0 == SECSPERREPEAT; } static int tzload(FAR const char *name, FAR struct state_s *sp, int doextend) { FAR const char *p; int i; int fid; int stored; int nread; typedef union { struct tzhead_s tzhead; char buf[2 * sizeof(struct tzhead_s) + 2 * sizeof *sp + 4 * TZ_MAX_TIMES]; } u_t; /* Section 4.9.1 of the C standard says that * "FILENAME_MAX expands to an integral constant expression * that is the size needed for an array of char large enough * to hold the longest file name string that the implementation * guarantees can be opened." */ union local_storage { char fullname[FILENAME_MAX + 1]; /* The main part of the storage for this function. */ struct { u_t u; struct state_s st; } u; }; FAR char *fullname; FAR u_t *up; int doaccess; FAR union local_storage *lsp; lsp = lib_malloc(sizeof *lsp); if (!lsp) { return -1; } fullname = lsp->fullname; up = &lsp->u.u; sp->goback = sp->goahead = FALSE; if (name == NULL) { name = TZDEFAULT; if (name == NULL) { goto oops; } } if (name[0] == ':') { ++name; } doaccess = name[0] == '/'; if (!doaccess) { p = TZDIR; if (p == NULL || FILENAME_MAX <= strlen(p) + strlen(name)) { goto oops; } strcpy(fullname, p); strcat(fullname, "/"); strcat(fullname, name); /* Set doaccess if '.' (as in "../") shows up in name. */ if (strchr(name, '.')) { doaccess = TRUE; } name = fullname; } if (doaccess && access(name, R_OK) != 0) { goto oops; } fid = _NX_OPEN(name, O_RDONLY | O_BINARY); if (fid < 0) { goto oops; } nread = _NX_READ(fid, up->buf, sizeof up->buf); if (_NX_CLOSE(fid) < 0 || nread <= 0) { goto oops; } for (stored = 4; stored <= 8; stored *= 2) { int ttisstdcnt; int ttisgmtcnt; int timecnt; ttisstdcnt = (int)detzcode(up->tzhead.tzh_ttisstdcnt); ttisgmtcnt = (int)detzcode(up->tzhead.tzh_ttisgmtcnt); sp->leapcnt = (int)detzcode(up->tzhead.tzh_leapcnt); sp->timecnt = (int)detzcode(up->tzhead.tzh_timecnt); sp->typecnt = (int)detzcode(up->tzhead.tzh_typecnt); sp->charcnt = (int)detzcode(up->tzhead.tzh_charcnt); p = up->tzhead.tzh_charcnt + sizeof up->tzhead.tzh_charcnt; if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) || (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0)) { goto oops; } if (nread - (p - up->buf) < sp->timecnt * stored + /* ats */ sp->timecnt + /* types */ sp->typecnt * 6 + /* ttinfos */ sp->charcnt + /* chars */ sp->leapcnt * (stored + 4) + /* lsinfos */ ttisstdcnt + /* ttisstds */ ttisgmtcnt) /* ttisgmts */ { goto oops; } timecnt = 0; for (i = 0; i < sp->timecnt; ++i) { int_fast64_t at = stored == 4 ? detzcode(p) : detzcode64(p); sp->types[i] = ((TYPE_SIGNED(time_t) ? g_min_timet <= at : 0 <= at) && at <= g_max_timet); if (sp->types[i]) { if (i && !timecnt && at != g_min_timet) { /* Keep the earlier record, but tweak * it so that it starts with the * minimum time_t value. */ sp->types[i - 1] = 1; sp->ats[timecnt++] = g_min_timet; } sp->ats[timecnt++] = at; } p += stored; } timecnt = 0; for (i = 0; i < sp->timecnt; ++i) { unsigned char typ = *p++; if (sp->typecnt <= typ) { goto oops; } if (sp->types[i]) { sp->types[timecnt++] = typ; } } sp->timecnt = timecnt; for (i = 0; i < sp->typecnt; ++i) { FAR struct ttinfo_s *ttisp; ttisp = &sp->ttis[i]; ttisp->tt_gmtoff = detzcode(p); p += 4; ttisp->tt_isdst = (unsigned char)*p++; if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) { goto oops; } ttisp->tt_abbrind = (unsigned char)*p++; if (ttisp->tt_abbrind < 0 || ttisp->tt_abbrind > sp->charcnt) { goto oops; } } for (i = 0; i < sp->charcnt; ++i) { sp->chars[i] = *p++; } sp->chars[i] = '\0'; /* ensure '\0' at end */ for (i = 0; i < sp->leapcnt; ++i) { FAR struct lsinfo_s *lsisp; lsisp = &sp->lsis[i]; lsisp->ls_trans = (stored == 4) ? detzcode(p) : detzcode64(p); p += stored; lsisp->ls_corr = detzcode(p); p += 4; } for (i = 0; i < sp->typecnt; ++i) { FAR struct ttinfo_s *ttisp; ttisp = &sp->ttis[i]; if (ttisstdcnt == 0) { ttisp->tt_ttisstd = FALSE; } else { ttisp->tt_ttisstd = *p++; if (ttisp->tt_ttisstd != TRUE && ttisp->tt_ttisstd != FALSE) { goto oops; } } } for (i = 0; i < sp->typecnt; ++i) { FAR struct ttinfo_s *ttisp; ttisp = &sp->ttis[i]; if (ttisgmtcnt == 0) { ttisp->tt_ttisgmt = FALSE; } else { ttisp->tt_ttisgmt = *p++; if (ttisp->tt_ttisgmt != TRUE && ttisp->tt_ttisgmt != FALSE) { goto oops; } } } /* If this is an old file, we're done. */ if (up->tzhead.tzh_version[0] == '\0') { break; } nread -= p - up->buf; for (i = 0; i < nread; ++i) { up->buf[i] = p[i]; } /* If this is a signed narrow time_t system, we're done. */ if (TYPE_SIGNED(time_t) && stored >= (int)sizeof(time_t)) { break; } } if (doextend && nread > 2 && up->buf[0] == '\n' && up->buf[nread - 1] == '\n' && sp->typecnt + 2 <= TZ_MAX_TYPES) { FAR struct state_s *ts = &lsp->u.st; int result; up->buf[nread - 1] = '\0'; result = tzparse(&up->buf[1], ts, FALSE); if (result == 0 && ts->typecnt == 2 && sp->charcnt + ts->charcnt <= TZ_MAX_CHARS) { for (i = 0; i < 2; ++i) { ts->ttis[i].tt_abbrind += sp->charcnt; } for (i = 0; i < ts->charcnt; ++i) { sp->chars[sp->charcnt++] = ts->chars[i]; } i = 0; while (i < ts->timecnt && ts->ats[i] <= sp->ats[sp->timecnt - 1]) { ++i; } while (i < ts->timecnt && sp->timecnt < TZ_MAX_TIMES) { sp->ats[sp->timecnt] = ts->ats[i]; sp->types[sp->timecnt] = sp->typecnt + ts->types[i]; ++sp->timecnt; ++i; } sp->ttis[sp->typecnt++] = ts->ttis[0]; sp->ttis[sp->typecnt++] = ts->ttis[1]; } } if (sp->timecnt > 1) { for (i = 1; i < sp->timecnt; ++i) { if (typesequiv(sp, sp->types[i], sp->types[0]) && differ_by_repeat(sp->ats[i], sp->ats[0])) { sp->goback = TRUE; break; } } for (i = sp->timecnt - 2; i >= 0; --i) { if (typesequiv(sp, sp->types[sp->timecnt - 1], sp->types[i]) && differ_by_repeat(sp->ats[sp->timecnt - 1], sp->ats[i])) { sp->goahead = TRUE; break; } } } /* If type 0 is is unused in transitions, it's the type to use for early * times. */ for (i = 0; i < sp->typecnt; ++i) { if (sp->types[i] == 0) { break; } } i = (i >= sp->typecnt) ? 0 : -1; /* Absent the above, if there are transition times and the first * transition is to a daylight time find the standard type less than and * closest to the type of the first transition. */ if (i < 0 && sp->timecnt > 0 && sp->ttis[sp->types[0]].tt_isdst) { i = sp->types[0]; while (--i >= 0) { if (!sp->ttis[i].tt_isdst) { break; } } } /* If no result yet, find the first standard type. If there is none, punt * to type zero. */ if (i < 0) { i = 0; while (sp->ttis[i].tt_isdst) { if (++i >= sp->typecnt) { i = 0; break; } } } sp->defaulttype = i; lib_free(lsp); return 0; oops: lib_free(lsp); return -1; } static int typesequiv(FAR const struct state_s *sp, int a, int b) { int result; if (sp == NULL || a < 0 || a >= sp->typecnt || b < 0 || b >= sp->typecnt) { result = FALSE; } else { FAR const struct ttinfo_s *ap = &sp->ttis[a]; FAR const struct ttinfo_s *bp = &sp->ttis[b]; result = ap->tt_gmtoff == bp->tt_gmtoff && ap->tt_isdst == bp->tt_isdst && ap->tt_ttisstd == bp->tt_ttisstd && ap->tt_ttisgmt == bp->tt_ttisgmt && strcmp(&sp->chars[ap->tt_abbrind], &sp->chars[bp->tt_abbrind]) == 0; } return result; } /* Given a pointer into a time zone string, scan until a character that is * not a valid character in a zone name is found. Return a pointer to that * character. */ static FAR const char *getzname(FAR const char *strp) { char c; while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && c != '+') { ++strp; } return strp; } /* Given a pointer into an extended time zone string, scan until the ending * delimiter of the zone name is located. Return a pointer to the delimiter. * * As with getzname above, the legal character set is actually quite * restricted, with other characters producing undefined results. * We don't do any checking here; checking is done later in common-case code. */ static FAR const char *getqzname(FAR const char *strp, int delim) { int c; while ((c = *strp) != '\0' && c != delim) { ++strp; } return strp; } /* Given a pointer into a time zone string, extract a number from that * string. Check that the number is within a specified range; if it is not, * return NULL. Otherwise, return a pointer to the first character not part * of the number. */ static FAR const char *getnum(FAR const char *strp, FAR int *nump, int min, int max) { char c; int num; if (strp == NULL || !is_digit(c = *strp)) { return NULL; } num = 0; do { num = num * 10 + (c - '0'); if (num > max) { return NULL; /* illegal value */ } c = *++strp; } while (is_digit(c)); if (num < min) { return NULL; /* illegal value */ } *nump = num; return strp; } /* Given a pointer into a time zone string, extract a number of seconds, * in hh[:mm[:ss]] form, from the string. * If any error occurs, return NULL. * Otherwise, return a pointer to the first character not part of the number * of seconds. */ static FAR const char *getsecs(FAR const char *strp, FAR int_fast32_t *secsp) { int num; /* 'HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like * "M10.4.6/26", which does not conform to Posix, * but which specifies the equivalent of * "02:00 on the first Sunday on or after 23 Oct". */ strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1); if (strp == NULL) { return NULL; } *secsp = num * (int_fast32_t)SECSPERHOUR; if (*strp == ':') { ++strp; strp = getnum(strp, &num, 0, MINSPERHOUR - 1); if (strp == NULL) { return NULL; } *secsp += num * SECSPERMIN; if (*strp == ':') { ++strp; /* 'SECSPERMIN' allows for leap seconds. */ strp = getnum(strp, &num, 0, SECSPERMIN); if (strp == NULL) { return NULL; } *secsp += num; } } return strp; } /* Given a pointer into a time zone string, extract an offset, in * [+-]hh[:mm[:ss]] form, from the string. * If any error occurs, return NULL. * Otherwise, return a pointer to the first character not part of the time. */ static FAR const char *getoffset(FAR const char *strp, FAR int_fast32_t *offsetp) { int neg = 0; if (*strp == '-') { neg = 1; ++strp; } else if (*strp == '+') { ++strp; } strp = getsecs(strp, offsetp); if (strp == NULL) { return NULL; /* illegal time */ } if (neg) { *offsetp = -*offsetp; } return strp; } /* Given a pointer into a time zone string, extract a rule in the form * date[/time]. See POSIX section 8 for the format of "date" and "time". * If a valid rule is not found, return NULL. * Otherwise, return a pointer to the first character not part of the rule. */ static FAR const char *getrule(FAR const char *strp, FAR struct rule_s *rulep) { if (*strp == 'J') { /* Julian day */ rulep->r_type = JULIAN_DAY; ++strp; strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); } else if (*strp == 'M') { /* Month, week, day. */ rulep->r_type = MONTH_NTH_DAY_OF_WEEK; ++strp; strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); if (strp == NULL) { return NULL; } if (*strp++ != '.') { return NULL; } strp = getnum(strp, &rulep->r_week, 1, 5); if (strp == NULL) { return NULL; } if (*strp++ != '.') { return NULL; } strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); } else if (is_digit(*strp)) { /* Day of year */ rulep->r_type = DAY_OF_YEAR; strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); } else { return NULL; /* invalid format */ } if (strp == NULL) { return NULL; } if (*strp == '/') { /* Time specified */ ++strp; strp = getoffset(strp, &rulep->r_time); } else { rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ } return strp; } /* Given a year, a rule, and the offset from UT at the time that rule takes * effect, calculate the year-relative time that rule takes effect. */ static int_fast32_t transtime(int year, FAR const struct rule_s *rulep, int_fast32_t offset) { int leapyear; int_fast32_t value; int i; int d; int m1; int yy0; int yy1; int yy2; int dow; value = 0; leapyear = isleap(year); switch (rulep->r_type) { case JULIAN_DAY: /* Jn - Julian day, 1 == January 1, 60 == March 1 even in leap * years. * In non-leap years, or if the day number is 59 or less, just * add SECSPERDAY times the day number-1 to the time of * January 1, midnight, to get the day. */ value = (rulep->r_day - 1) * SECSPERDAY; if (leapyear && rulep->r_day >= 60) { value += SECSPERDAY; } break; case DAY_OF_YEAR: /* n - day of year. * Just add SECSPERDAY times the day number to the time of * January 1, midnight, to get the day. */ value = rulep->r_day * SECSPERDAY; break; case MONTH_NTH_DAY_OF_WEEK: /* Mm.n.d - nth "dth day" of month m */ /* Use Zeller's Congruence to get day-of-week of first day of * month. */ m1 = (rulep->r_mon + 9) % 12 + 1; yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; yy1 = yy0 / 100; yy2 = yy0 % 100; dow = ((26 * m1 - 2) / 10 + 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; if (dow < 0) { dow += DAYSPERWEEK; } /* "dow" is the day-of-week of the first day of the month. Get * the day-of-month (zero-origin) of the first "dow" day of the * month. */ d = rulep->r_day - dow; if (d < 0) { d += DAYSPERWEEK; } for (i = 1; i < rulep->r_week; ++i) { if (d + DAYSPERWEEK >= g_mon_lengths[leapyear][rulep->r_mon - 1]) { break; } d += DAYSPERWEEK; } /* "d" is the day-of-month (zero-origin) of the day we want */ value = d * SECSPERDAY; for (i = 0; i < rulep->r_mon - 1; ++i) { value += g_mon_lengths[leapyear][i] * SECSPERDAY; } break; } /* "value" is the year-relative time of 00:00:00 UT on the day in * question. To get the year-relative time of the specified local * time on that day, add the transition time and the current offset * from UT. */ return value + rulep->r_time + offset; } /* Given a POSIX section 8-style TZ string, fill in the rule tables as * appropriate. */ static int tzparse(FAR const char *name, FAR struct state_s *sp, int lastditch) { FAR const char *stdname; FAR const char *dstname; size_t stdlen; size_t dstlen; int_fast32_t stdoffset; int_fast32_t dstoffset; FAR char *cp; int load_result; static struct ttinfo_s zttinfo; stdname = name; if (lastditch) { stdlen = strlen(name); /* length of standard zone name */ name += stdlen; if (stdlen >= sizeof sp->chars) { stdlen = (sizeof sp->chars) - 1; } stdoffset = 0; } else { if (*name == '<') { name++; stdname = name; name = getqzname(name, '>'); if (*name != '>') { return -1; } stdlen = name - stdname; name++; } else { name = getzname(name); stdlen = name - stdname; } if (*name == '\0') { return -1; } name = getoffset(name, &stdoffset); if (name == NULL) { return -1; } } load_result = tzload(TZDEFRULES, sp, FALSE); if (load_result != 0) { sp->leapcnt = 0; /* so, we're off a little */ } if (*name != '\0') { if (*name == '<') { dstname = ++name; name = getqzname(name, '>'); if (*name != '>') { return -1; } dstlen = name - dstname; name++; } else { dstname = name; name = getzname(name); dstlen = name - dstname; /* length of DST zone name */ } if (*name != '\0' && *name != ',' && *name != ';') { name = getoffset(name, &dstoffset); if (name == NULL) { return -1; } } else { dstoffset = stdoffset - SECSPERHOUR; } if (*name == '\0' && load_result != 0) { name = TZDEFRULESTRING; } if (*name == ',' || *name == ';') { struct rule_s start; struct rule_s end; int year; int yearlim; int timecnt; time_t janfirst; ++name; if ((name = getrule(name, &start)) == NULL) { return -1; } if (*name++ != ',') { return -1; } if ((name = getrule(name, &end)) == NULL) { return -1; } if (*name != '\0') { return -1; } sp->typecnt = 2; /* standard time and DST */ /* Two transitions per year, from EPOCH_YEAR forward */ sp->ttis[0] = sp->ttis[1] = zttinfo; sp->ttis[0].tt_gmtoff = -dstoffset; sp->ttis[0].tt_isdst = 1; sp->ttis[0].tt_abbrind = stdlen + 1; sp->ttis[1].tt_gmtoff = -stdoffset; sp->ttis[1].tt_isdst = 0; sp->ttis[1].tt_abbrind = 0; sp->defaulttype = 0; timecnt = 0; janfirst = 0; yearlim = EPOCH_YEAR + YEARSPERREPEAT; for (year = EPOCH_YEAR; year < yearlim; year++) { int_fast32_t starttime = transtime(year, &start, stdoffset); int_fast32_t endtime = transtime(year, &end, dstoffset); int_fast32_t yearsecs = (g_year_lengths[isleap(year)] * SECSPERDAY); int reversed = endtime < starttime; if (reversed) { int_fast32_t swap = starttime; starttime = endtime; endtime = swap; } if (reversed || (starttime < endtime && (endtime - starttime < (yearsecs + (stdoffset - dstoffset))))) { if (TZ_MAX_TIMES - 2 < timecnt) { break; } yearlim = year + YEARSPERREPEAT + 1; sp->ats[timecnt] = janfirst; if (increment_overflow_time(&sp->ats[timecnt], starttime)) { break; } sp->types[timecnt++] = reversed; sp->ats[timecnt] = janfirst; if (increment_overflow_time(&sp->ats[timecnt], endtime)) { break; } sp->types[timecnt++] = !reversed; } if (increment_overflow_time(&janfirst, yearsecs)) { break; } } sp->timecnt = timecnt; if (!timecnt) { sp->typecnt = 1; /* Perpetual DST. */ } } else { int_fast32_t theirstdoffset; int_fast32_t theirdstoffset; int_fast32_t theiroffset; int isdst; int i; int j; if (*name != '\0') { return -1; } /* Initial values of theirstdoffset and theirdstoffset */ theirstdoffset = 0; for (i = 0; i < sp->timecnt; ++i) { j = sp->types[i]; if (!sp->ttis[j].tt_isdst) { theirstdoffset = -sp->ttis[j].tt_gmtoff; break; } } theirdstoffset = 0; for (i = 0; i < sp->timecnt; ++i) { j = sp->types[i]; if (sp->ttis[j].tt_isdst) { theirdstoffset = -sp->ttis[j].tt_gmtoff; break; } } /* Initially we're assumed to be in standard time */ isdst = FALSE; theiroffset = theirstdoffset; /* Now juggle transition times and types * tracking offsets as you do. */ for (i = 0; i < sp->timecnt; ++i) { j = sp->types[i]; sp->types[i] = sp->ttis[j].tt_isdst; if (sp->ttis[j].tt_ttisgmt) { /* No adjustment to transition time */ } else { /* If summer time is in effect, and the * transition time was not specified as * standard time, add the summer time * offset to the transition time; * otherwise, add the standard time * offset to the transition time. * * Transitions from DST to DDST * will effectively disappear since * POSIX provides for only one DST * offset. */ if (isdst && !sp->ttis[j].tt_ttisstd) { sp->ats[i] += dstoffset - theirdstoffset; } else { sp->ats[i] += stdoffset - theirstdoffset; } } theiroffset = -sp->ttis[j].tt_gmtoff; if (sp->ttis[j].tt_isdst) { theirdstoffset = theiroffset; } else { theirstdoffset = theiroffset; } } /* Finally, fill in ttis */ sp->ttis[0] = sp->ttis[1] = zttinfo; sp->ttis[0].tt_gmtoff = -stdoffset; sp->ttis[0].tt_isdst = FALSE; sp->ttis[0].tt_abbrind = 0; sp->ttis[1].tt_gmtoff = -dstoffset; sp->ttis[1].tt_isdst = TRUE; sp->ttis[1].tt_abbrind = stdlen + 1; sp->typecnt = 2; sp->defaulttype = 0; } } else { dstlen = 0; sp->typecnt = 1; /* only standard time */ sp->timecnt = 0; sp->ttis[0] = zttinfo; sp->ttis[0].tt_gmtoff = -stdoffset; sp->ttis[0].tt_isdst = 0; sp->ttis[0].tt_abbrind = 0; sp->defaulttype = 0; } sp->charcnt = stdlen + 1; if (dstlen != 0) { sp->charcnt += dstlen + 1; } if ((size_t)sp->charcnt > sizeof sp->chars) { return -1; } cp = sp->chars; strncpy(cp, stdname, stdlen); cp += stdlen; *cp++ = '\0'; if (dstlen != 0) { strncpy(cp, dstname, dstlen); *(cp + dstlen) = '\0'; } return 0; } static void gmtload(FAR struct state_s *sp) { if (tzload(GMT, sp, TRUE) != 0) { tzparse(GMT, sp, TRUE); } } /* A non-static declaration of tzsetwall in a system header file * may cause a warning about this upcoming static declaration... */ static void tzsetwall(void) { if (g_lcl_isset < 0) { return; } if (g_lcl_ptr == NULL) { g_lcl_ptr = lib_malloc(sizeof *g_lcl_ptr); } if (g_lcl_ptr != NULL && tzload(NULL, g_lcl_ptr, TRUE) != 0) { gmtload(g_lcl_ptr); } settzname(); g_lcl_isset = -1; } /* The easy way to behave "as if no library function calls" localtime * is to not call it, so we drop its guts into "localsub", which can be * freely called. (And no, the PANS doesn't require the above behavior, * but it *is* desirable.) * * The unused offset argument is for the benefit of mktime variants. */ static FAR struct tm *localsub(FAR const time_t *timep, int_fast32_t offset, FAR struct tm *tmp) { FAR struct state_s *sp; FAR const struct ttinfo_s *ttisp; int i; FAR struct tm *result; const time_t t = *timep; sp = g_lcl_ptr; if (sp == NULL) { return gmtsub(timep, offset, tmp); } if ((sp->goback && t < sp->ats[0]) || (sp->goahead && t > sp->ats[sp->timecnt - 1])) { time_t newt = t; time_t seconds; time_t years; if (t < sp->ats[0]) { seconds = sp->ats[0] - t; } else { seconds = t - sp->ats[sp->timecnt - 1]; } --seconds; years = (seconds / SECSPERREPEAT + 1) * YEARSPERREPEAT; seconds = years * AVGSECSPERYEAR; if (t < sp->ats[0]) { newt += seconds; } else { newt -= seconds; } if (newt < sp->ats[0] || newt > sp->ats[sp->timecnt - 1]) { return NULL; /* "cannot happen" */ } result = localsub(&newt, offset, tmp); if (result == tmp) { time_t newy; newy = tmp->tm_year; if (t < sp->ats[0]) { newy -= years; } else { newy += years; } tmp->tm_year = newy; if (tmp->tm_year != newy) { return NULL; } } return result; } if (sp->timecnt == 0 || t < sp->ats[0]) { i = sp->defaulttype; } else { int lo = 1; int hi = sp->timecnt; while (lo < hi) { int mid = (lo + hi) >> 1; if (t < sp->ats[mid]) { hi = mid; } else { lo = mid + 1; } } i = (int)sp->types[lo - 1]; } ttisp = &sp->ttis[i]; /* To get (wrong) behavior that's compatible with System V Release 2.0 * you'd replace the statement below with * t += ttisp->tt_gmtoff; * timesub(&t, 0L, sp, tmp); */ result = timesub(&t, ttisp->tt_gmtoff, sp, tmp); tmp->tm_isdst = ttisp->tt_isdst; tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind]; tmp->tm_zone = tzname[tmp->tm_isdst]; return result; } /* gmtsub is to gmtime as localsub is to localtime */ static FAR struct tm *gmtsub(FAR const time_t *timep, int_fast32_t offset, FAR struct tm *tmp) { tz_semtake(&g_gmt_sem); if (!g_gmt_isset) { g_gmt_ptr = lib_malloc(sizeof *g_gmt_ptr); if (g_gmt_ptr != NULL) { gmtload(g_gmt_ptr); g_gmt_isset = 1; } } tz_semgive(&g_gmt_sem); tmp->tm_zone = GMT; return timesub(timep, offset, g_gmt_ptr, tmp); } /* Return the number of leap years through the end of the given year * where, to make the math easy, the answer for year zero is defined as zero. */ static int leaps_thru_end_of(int y) { return (y >= 0) ? (y / 4 - y / 100 + y / 400) : -(leaps_thru_end_of(-(y + 1)) + 1); } static FAR struct tm *timesub(FAR const time_t *timep, int_fast32_t offset, FAR const struct state_s *sp, FAR struct tm *tmp) { FAR const struct lsinfo_s *lp; time_t tdays; int idays; /* unsigned would be so 2003 */ int_fast32_t rem; int y; FAR const int *ip; int_fast32_t corr; int hit; int i; corr = 0; hit = 0; i = (sp == NULL) ? 0 : sp->leapcnt; while (--i >= 0) { lp = &sp->lsis[i]; if (*timep >= lp->ls_trans) { if (*timep == lp->ls_trans) { hit = ((i == 0 && lp->ls_corr > 0) || lp->ls_corr > sp->lsis[i - 1].ls_corr); if (hit) { while (i > 0 && sp->lsis[i].ls_trans == sp->lsis[i - 1].ls_trans + 1 && sp->lsis[i].ls_corr == sp->lsis[i - 1].ls_corr + 1) { ++hit; --i; } } } corr = lp->ls_corr; break; } } y = EPOCH_YEAR; tdays = *timep / SECSPERDAY; rem = *timep - tdays * SECSPERDAY; while (tdays < 0 || tdays >= g_year_lengths[isleap(y)]) { int newy; time_t tdelta; int idelta; int leapdays; tdelta = tdays / DAYSPERLYEAR; if (!((!TYPE_SIGNED(time_t) || INT_MIN <= tdelta) && tdelta <= INT_MAX)) { return NULL; } idelta = tdelta; if (idelta == 0) { idelta = (tdays < 0) ? -1 : 1; } newy = y; if (increment_overflow(&newy, idelta)) { return NULL; } leapdays = leaps_thru_end_of(newy - 1) - leaps_thru_end_of(y - 1); tdays -= ((time_t)newy - y) * DAYSPERNYEAR; tdays -= leapdays; y = newy; } { int_fast32_t seconds; seconds = tdays * SECSPERDAY; tdays = seconds / SECSPERDAY; rem += seconds - tdays * SECSPERDAY; } /* Given the range, we can now fearlessly cast */ idays = tdays; rem += offset - corr; while (rem < 0) { rem += SECSPERDAY; --idays; } while (rem >= SECSPERDAY) { rem -= SECSPERDAY; ++idays; } while (idays < 0) { if (increment_overflow(&y, -1)) { return NULL; } idays += g_year_lengths[isleap(y)]; } while (idays >= g_year_lengths[isleap(y)]) { idays -= g_year_lengths[isleap(y)]; if (increment_overflow(&y, 1)) { return NULL; } } tmp->tm_year = y; if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE)) { return NULL; } tmp->tm_yday = idays; /* The "extra" mods below avoid overflow problems */ tmp->tm_wday = EPOCH_WDAY + ((y - EPOCH_YEAR) % DAYSPERWEEK) * (DAYSPERNYEAR % DAYSPERWEEK) + leaps_thru_end_of(y - 1) - leaps_thru_end_of(EPOCH_YEAR - 1) + idays; tmp->tm_wday %= DAYSPERWEEK; if (tmp->tm_wday < 0) { tmp->tm_wday += DAYSPERWEEK; } tmp->tm_hour = (int)(rem / SECSPERHOUR); rem %= SECSPERHOUR; tmp->tm_min = (int)(rem / SECSPERMIN); /* A positive leap second requires a special * representation. This uses "... ??:59:60" et seq. */ tmp->tm_sec = (int)(rem % SECSPERMIN) + hit; ip = g_mon_lengths[isleap(y)]; for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon)) { idays -= ip[tmp->tm_mon]; } tmp->tm_mday = (int)(idays + 1); tmp->tm_isdst = 0; tmp->tm_gmtoff = offset; return tmp; } /* Adapted from code provided by Robert Elz, who writes: * The "best" way to do mktime I think is based on an idea of Bob * Kridle's (so its said...) from a long time ago. * It does a binary search of the time_t space. Since time_t's are * just 32 bits, its a max of 32 iterations (even at 64 bits it * would still be very reasonable). */ /* Normalize logic courtesy Paul Eggert */ static int increment_overflow(FAR int *ip, int j) { const int i = *ip; /* If i >= 0 there can only be overflow if i + j > INT_MAX * or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow. * If i < 0 there can only be overflow if i + j < INT_MIN * or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow. */ if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i)) { return TRUE; } *ip += j; return FALSE; } static int increment_overflow32(FAR int_fast32_t *lp, int m) { const int_fast32_t l = *lp; if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l)) { return TRUE; } *lp += m; return FALSE; } static int increment_overflow_time(FAR time_t *tp, int_fast32_t j) { /* This is like * 'if (! (g_min_timet <= *tp + j && *tp + j <= g_max_timet)) ...', * except that it does the right thing even if *tp + j would overflow. */ if (!(j < 0 ? (TYPE_SIGNED(time_t) ? g_min_timet - j <= *tp : -1 - j < *tp) : *tp <= g_max_timet - j)) { return TRUE; } *tp += j; return FALSE; } static int normalize_overflow(FAR int *tensptr, FAR int *unitsptr, int base) { int tensdelta; tensdelta = (*unitsptr >= 0) ? (*unitsptr / base) : (-1 - (-1 - *unitsptr) / base); *unitsptr -= tensdelta * base; return increment_overflow(tensptr, tensdelta); } static int normalize_overflow32(FAR int_fast32_t *tensptr, FAR int *unitsptr, int base) { int tensdelta; tensdelta = (*unitsptr >= 0) ? (*unitsptr / base) : (-1 - (-1 - *unitsptr) / base); *unitsptr -= tensdelta * base; return increment_overflow32(tensptr, tensdelta); } static int tmcomp(FAR const struct tm *atmp, FAR const struct tm *btmp) { int result; if (atmp->tm_year != btmp->tm_year) { return atmp->tm_year < btmp->tm_year ? -1 : 1; } if ((result = (atmp->tm_mon - btmp->tm_mon)) == 0 && (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && (result = (atmp->tm_min - btmp->tm_min)) == 0) { result = atmp->tm_sec - btmp->tm_sec; } return result; } static time_t time2sub(FAR struct tm *tmp, FAR struct tm *(*funcp)(FAR const time_t *, int_fast32_t, FAR struct tm *), int_fast32_t offset, FAR int *okayp, int do_norm_secs) { FAR const struct state_s *sp; int dir; int i; int j; int saved_seconds; int_fast32_t li; time_t lo; time_t hi; int_fast32_t y; time_t newt; time_t t; struct tm yourtm; struct tm mytm; *okayp = FALSE; yourtm = *tmp; if (do_norm_secs) { if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, SECSPERMIN)) { return -1; } } if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) { return -1; } if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) { return -1; } y = yourtm.tm_year; if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR)) { return -1; } /* Turn y into an actual year number for now. * It is converted back to an offset from TM_YEAR_BASE later. */ if (increment_overflow32(&y, TM_YEAR_BASE)) { return -1; } while (yourtm.tm_mday <= 0) { if (increment_overflow32(&y, -1)) { return -1; } li = y + (1 < yourtm.tm_mon); yourtm.tm_mday += g_year_lengths[isleap(li)]; } while (yourtm.tm_mday > DAYSPERLYEAR) { li = y + (1 < yourtm.tm_mon); yourtm.tm_mday -= g_year_lengths[isleap(li)]; if (increment_overflow32(&y, 1)) { return -1; } } for (; ; ) { i = g_mon_lengths[isleap(y)][yourtm.tm_mon]; if (yourtm.tm_mday <= i) { break; } yourtm.tm_mday -= i; if (++yourtm.tm_mon >= MONSPERYEAR) { yourtm.tm_mon = 0; if (increment_overflow32(&y, 1)) { return -1; } } } if (increment_overflow32(&y, -TM_YEAR_BASE)) { return -1; } yourtm.tm_year = y; if (yourtm.tm_year != y) { return -1; } if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN) { saved_seconds = 0; } else if (y + TM_YEAR_BASE < EPOCH_YEAR) { /* We can't set tm_sec to 0, because that might push the * time below the minimum representable time. * Set tm_sec to 59 instead. * This assumes that the minimum representable time is * not in the same minute that a leap second was deleted from, * which is a safer assumption than using 58 would be. */ if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) { return -1; } saved_seconds = yourtm.tm_sec; yourtm.tm_sec = SECSPERMIN - 1; } else { saved_seconds = yourtm.tm_sec; yourtm.tm_sec = 0; } /* Do a binary search (this works whatever time_t's type is) */ if (!TYPE_SIGNED(time_t)) { lo = 0; hi = lo - 1; } else { lo = 1; for (i = 0; i < (int)TYPE_BIT(time_t) - 1; ++i) { lo *= 2; } hi = -(lo + 1); } for (; ; ) { t = lo / 2 + hi / 2; if (t < lo) { t = lo; } else if (t > hi) { t = hi; } if ((*funcp) (&t, offset, &mytm) == NULL) { /* Assume that t is too extreme to be represented in * a struct tm; arrange things so that it is less * extreme on the next pass. */ dir = (t > 0) ? 1 : -1; } else { dir = tmcomp(&mytm, &yourtm); } if (dir != 0) { if (t == lo) { if (t == g_max_timet) { return -1; } ++t; ++lo; } else if (t == hi) { if (t == g_min_timet) { return -1; } --t; --hi; } if (lo > hi) { return -1; } if (dir > 0) { hi = t; } else { lo = t; } continue; } if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) { break; } /* Right time, wrong type. * Hunt for right time, right type. * It's okay to guess wrong since the guess * gets checked. */ sp = (FAR const struct state_s *) ((funcp == localsub) ? g_lcl_ptr : g_gmt_ptr); if (sp == NULL) { return -1; } for (i = sp->typecnt - 1; i >= 0; --i) { if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) { continue; } for (j = sp->typecnt - 1; j >= 0; --j) { if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) { continue; } newt = t + sp->ttis[j].tt_gmtoff - sp->ttis[i].tt_gmtoff; if ((*funcp) (&newt, offset, &mytm) == NULL) { continue; } if (tmcomp(&mytm, &yourtm) != 0) { continue; } if (mytm.tm_isdst != yourtm.tm_isdst) { continue; } /* We have a match */ t = newt; goto label; } } return -1; } label: newt = t + saved_seconds; if ((newt < t) != (saved_seconds < 0)) { return -1; } t = newt; if ((*funcp) (&t, offset, tmp)) { *okayp = TRUE; } return t; } static time_t time2(FAR struct tm *tmp, FAR struct tm *(*funcp)(FAR const time_t *, int_fast32_t, FAR struct tm *), int_fast32_t offset, FAR int *okayp) { time_t t; /* First try without normalization of seconds * (in case tm_sec contains a value associated with a leap second). * If that fails, try with normalization of seconds. */ t = time2sub(tmp, funcp, offset, okayp, FALSE); return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE); } static time_t time1(FAR struct tm *tmp, FAR struct tm *(*funcp)(FAR const time_t *, int_fast32_t, FAR struct tm *), int_fast32_t offset) { time_t t; FAR const struct state_s *sp; int samei; int otheri; int sameind; int otherind; int i; int nseen; char seen[TZ_MAX_TYPES]; unsigned char types[TZ_MAX_TYPES]; int okay; if (tmp == NULL) { set_errno(EINVAL); return -1; } if (tmp->tm_isdst > 1) { tmp->tm_isdst = 1; } t = time2(tmp, funcp, offset, &okay); if (okay) { return t; } if (tmp->tm_isdst < 0) { return t; } /* We're supposed to assume that somebody took a time of one type * and did some math on it that yielded a "struct tm" that's bad. * We try to divine the type they started from and adjust to the * type they need. */ sp = ((funcp == localsub) ? g_lcl_ptr : g_gmt_ptr); if (sp == NULL) { return -1; } for (i = 0; i < sp->typecnt; ++i) { seen[i] = FALSE; } nseen = 0; for (i = sp->timecnt - 1; i >= 0; --i) { if (!seen[sp->types[i]]) { seen[sp->types[i]] = TRUE; types[nseen++] = sp->types[i]; } } for (sameind = 0; sameind < nseen; ++sameind) { samei = types[sameind]; if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) { continue; } for (otherind = 0; otherind < nseen; ++otherind) { otheri = types[otherind]; if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) { continue; } tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - sp->ttis[samei].tt_gmtoff; tmp->tm_isdst = !tmp->tm_isdst; t = time2(tmp, funcp, offset, &okay); if (okay) { return t; } tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - sp->ttis[samei].tt_gmtoff; tmp->tm_isdst = !tmp->tm_isdst; } } return -1; } /**************************************************************************** * Public Functions ****************************************************************************/ void tzset(void) { FAR const char *name; tz_semtake(&g_lcl_sem); name = getenv("TZ"); if (name == NULL) { tzsetwall(); goto out; } if (g_lcl_isset > 0 && strcmp(g_lcl_tzname, name) == 0) { goto out; } if (g_lcl_ptr == NULL) { g_lcl_ptr = lib_malloc(sizeof *g_lcl_ptr); if (g_lcl_ptr == NULL) { goto tzname; } } if (*name == '\0') { /* User wants it fast rather than right */ g_lcl_ptr->leapcnt = 0; /* so, we're off a little */ g_lcl_ptr->timecnt = 0; g_lcl_ptr->typecnt = 0; g_lcl_ptr->ttis[0].tt_isdst = 0; g_lcl_ptr->ttis[0].tt_gmtoff = 0; g_lcl_ptr->ttis[0].tt_abbrind = 0; strcpy(g_lcl_ptr->chars, GMT); } else if (tzload(name, g_lcl_ptr, TRUE) != 0) { if (name[0] == ':' || tzparse(name, g_lcl_ptr, FALSE) != 0) { gmtload(g_lcl_ptr); goto tzname; } } g_lcl_isset = strlen(name) < sizeof g_lcl_tzname; if (g_lcl_isset) { strcpy(g_lcl_tzname, name); } tzname: settzname(); out: tz_semgive(&g_lcl_sem); } FAR struct tm *localtime(FAR const time_t *timep) { tzset(); return localsub(timep, 0L, &g_tm); } /* Re-entrant version of localtime */ FAR struct tm *localtime_r(FAR const time_t *timep, FAR struct tm *tmp) { tzset(); return localsub(timep, 0L, tmp); } FAR struct tm *gmtime(FAR const time_t *timep) { return gmtsub(timep, 0L, &g_tm); } /* Re-entrant version of gmtime */ FAR struct tm *gmtime_r(FAR const time_t *timep, FAR struct tm *tmp) { return gmtsub(timep, 0L, tmp); } time_t mktime(FAR struct tm *tmp) { tzset(); return time1(tmp, localsub, 0L); } time_t timegm(FAR struct tm *tmp) { return time1(tmp, gmtsub, 0L); }