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Diffstat (limited to 'tz/localtime.c')
| -rw-r--r-- | tz/localtime.c | 2440 |
1 files changed, 2440 insertions, 0 deletions
diff --git a/tz/localtime.c b/tz/localtime.c new file mode 100644 index 0000000..913c7e8 --- /dev/null +++ b/tz/localtime.c @@ -0,0 +1,2440 @@ +/* Convert timestamp from time_t to struct tm. */ + +/* +** 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. +*/ + +/*LINTLIBRARY*/ + +#define LOCALTIME_IMPLEMENTATION +#include "private.h" + +#include "tzfile.h" +#include <fcntl.h> + +#if defined THREAD_SAFE && THREAD_SAFE +# include <pthread.h> +static pthread_mutex_t locallock = PTHREAD_MUTEX_INITIALIZER; +static int lock(void) { return pthread_mutex_lock(&locallock); } +static void unlock(void) { pthread_mutex_unlock(&locallock); } +#else +static int lock(void) { return 0; } +static void unlock(void) { } +#endif + +#ifndef TZ_ABBR_MAX_LEN +#define TZ_ABBR_MAX_LEN 16 +#endif /* !defined TZ_ABBR_MAX_LEN */ + +#ifndef TZ_ABBR_CHAR_SET +#define TZ_ABBR_CHAR_SET \ + "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._" +#endif /* !defined TZ_ABBR_CHAR_SET */ + +#ifndef TZ_ABBR_ERR_CHAR +#define TZ_ABBR_ERR_CHAR '_' +#endif /* !defined TZ_ABBR_ERR_CHAR */ + +/* +** SunOS 4.1.1 headers lack O_BINARY. +*/ + +#ifdef O_BINARY +#define OPEN_MODE (O_RDONLY | O_BINARY) +#endif /* defined O_BINARY */ +#ifndef O_BINARY +#define OPEN_MODE O_RDONLY +#endif /* !defined O_BINARY */ + +#ifndef WILDABBR +/* +** 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. +** 5. They might reference tm.TM_ZONE after calling offtime. +** 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 " " +#endif /* !defined WILDABBR */ + +static const char wildabbr[] = WILDABBR; + +static const char gmt[] = "GMT"; + +/* +** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. +** Default to US rules as of 2017-05-07. +** POSIX does not specify the default DST rules; +** for historical reasons, US rules are a common default. +*/ +#ifndef TZDEFRULESTRING +#define TZDEFRULESTRING ",M3.2.0,M11.1.0" +#endif + +struct ttinfo { /* time type information */ + int_fast32_t tt_utoff; /* UT offset in seconds */ + bool tt_isdst; /* used to set tm_isdst */ + int tt_desigidx; /* abbreviation list index */ + bool tt_ttisstd; /* transition is std time */ + bool tt_ttisut; /* transition is UT */ +}; + +struct lsinfo { /* leap second information */ + time_t ls_trans; /* transition time */ + int_fast32_t ls_corr; /* correction to apply */ +}; + +#define SMALLEST(a, b) (((a) < (b)) ? (a) : (b)) +#define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) + +/* This abbreviation means local time is unspecified. */ +static char const UNSPEC[] = "-00"; + +/* How many extra bytes are needed at the end of struct state's chars array. + This needs to be at least 1 for null termination in case the input + data isn't properly terminated, and it also needs to be big enough + for ttunspecified to work without crashing. */ +enum { CHARS_EXTRA = BIGGEST(sizeof UNSPEC, 2) - 1 }; + +#ifdef TZNAME_MAX +#define MY_TZNAME_MAX TZNAME_MAX +#endif /* defined TZNAME_MAX */ +#ifndef TZNAME_MAX +#define MY_TZNAME_MAX 255 +#endif /* !defined TZNAME_MAX */ + +struct state { + int leapcnt; + int timecnt; + int typecnt; + int charcnt; + bool goback; + bool goahead; + time_t ats[TZ_MAX_TIMES]; + unsigned char types[TZ_MAX_TIMES]; + struct ttinfo ttis[TZ_MAX_TYPES]; + char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + CHARS_EXTRA, + sizeof gmt), + (2 * (MY_TZNAME_MAX + 1)))]; + struct lsinfo lsis[TZ_MAX_LEAPS]; + + /* The time type to use for early times or if no transitions. + It is always zero for recent tzdb releases. + It might be nonzero for data from tzdb 2018e or earlier. */ + int defaulttype; +}; + +enum r_type { + JULIAN_DAY, /* Jn = Julian day */ + DAY_OF_YEAR, /* n = day of year */ + MONTH_NTH_DAY_OF_WEEK /* Mm.n.d = month, week, day of week */ +}; + +struct rule { + enum r_type r_type; /* type of rule */ + 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 */ +}; + +static struct tm *gmtsub(struct state const *, time_t const *, int_fast32_t, + struct tm *); +static bool increment_overflow(int *, int); +static bool increment_overflow_time(time_t *, int_fast32_t); +static int_fast32_t leapcorr(struct state const *, time_t); +static bool normalize_overflow32(int_fast32_t *, int *, int); +static struct tm *timesub(time_t const *, int_fast32_t, struct state const *, + struct tm *); +static bool typesequiv(struct state const *, int, int); +static bool tzparse(char const *, struct state *, struct state *); + +#ifdef ALL_STATE +static struct state * lclptr; +static struct state * gmtptr; +#endif /* defined ALL_STATE */ + +#ifndef ALL_STATE +static struct state lclmem; +static struct state gmtmem; +#define lclptr (&lclmem) +#define gmtptr (&gmtmem) +#endif /* State Farm */ + +#ifndef TZ_STRLEN_MAX +#define TZ_STRLEN_MAX 255 +#endif /* !defined TZ_STRLEN_MAX */ + +static char lcl_TZname[TZ_STRLEN_MAX + 1]; +static int lcl_is_set; + +/* +** 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 tm; + +#if 2 <= HAVE_TZNAME + TZ_TIME_T +char * tzname[2] = { + (char *) wildabbr, + (char *) wildabbr +}; +#endif +#if 2 <= USG_COMPAT + TZ_TIME_T +long timezone; +int daylight; +#endif +#if 2 <= ALTZONE + TZ_TIME_T +long altzone; +#endif + +/* Initialize *S to a value based on UTOFF, ISDST, and DESIGIDX. */ +static void +init_ttinfo(struct ttinfo *s, int_fast32_t utoff, bool isdst, int desigidx) +{ + s->tt_utoff = utoff; + s->tt_isdst = isdst; + s->tt_desigidx = desigidx; + s->tt_ttisstd = false; + s->tt_ttisut = false; +} + +/* Return true if SP's time type I does not specify local time. */ +static bool +ttunspecified(struct state const *sp, int i) +{ + char const *abbr = &sp->chars[sp->ttis[i].tt_desigidx]; + /* memcmp is likely faster than strcmp, and is safe due to CHARS_EXTRA. */ + return memcmp(abbr, UNSPEC, sizeof UNSPEC) == 0; +} + +static int_fast32_t +detzcode(const char *const codep) +{ + register int_fast32_t result; + register int i; + int_fast32_t one = 1; + int_fast32_t halfmaxval = one << (32 - 2); + int_fast32_t maxval = halfmaxval - 1 + halfmaxval; + int_fast32_t minval = -1 - maxval; + + result = codep[0] & 0x7f; + for (i = 1; i < 4; ++i) + result = (result << 8) | (codep[i] & 0xff); + + if (codep[0] & 0x80) { + /* Do two's-complement negation even on non-two's-complement machines. + If the result would be minval - 1, return minval. */ + result -= !TWOS_COMPLEMENT(int_fast32_t) && result != 0; + result += minval; + } + return result; +} + +static int_fast64_t +detzcode64(const char *const codep) +{ + register int_fast64_t result; + register int i; + int_fast64_t one = 1; + int_fast64_t halfmaxval = one << (64 - 2); + int_fast64_t maxval = halfmaxval - 1 + halfmaxval; + int_fast64_t minval = -TWOS_COMPLEMENT(int_fast64_t) - maxval; + + result = codep[0] & 0x7f; + for (i = 1; i < 8; ++i) + result = (result << 8) | (codep[i] & 0xff); + + if (codep[0] & 0x80) { + /* Do two's-complement negation even on non-two's-complement machines. + If the result would be minval - 1, return minval. */ + result -= !TWOS_COMPLEMENT(int_fast64_t) && result != 0; + result += minval; + } + return result; +} + +static void +update_tzname_etc(struct state const *sp, struct ttinfo const *ttisp) +{ +#if HAVE_TZNAME + tzname[ttisp->tt_isdst] = (char *) &sp->chars[ttisp->tt_desigidx]; +#endif +#if USG_COMPAT + if (!ttisp->tt_isdst) + timezone = - ttisp->tt_utoff; +#endif +#if ALTZONE + if (ttisp->tt_isdst) + altzone = - ttisp->tt_utoff; +#endif +} + +static void +settzname(void) +{ + register struct state * const sp = lclptr; + register int i; + +#if HAVE_TZNAME + tzname[0] = tzname[1] = (char *) (sp ? wildabbr : gmt); +#endif +#if USG_COMPAT + daylight = 0; + timezone = 0; +#endif +#if ALTZONE + altzone = 0; +#endif + if (sp == NULL) { + return; + } + /* + ** And to get the latest time zone abbreviations into tzname. . . + */ + for (i = 0; i < sp->typecnt; ++i) { + register const struct ttinfo * const ttisp = &sp->ttis[i]; + update_tzname_etc(sp, ttisp); + } + for (i = 0; i < sp->timecnt; ++i) { + register const struct ttinfo * const ttisp = + &sp->ttis[ + sp->types[i]]; + update_tzname_etc(sp, ttisp); +#if USG_COMPAT + if (ttisp->tt_isdst) + daylight = 1; +#endif + } +} + +static void +scrub_abbrs(struct state *sp) +{ + int i; + /* + ** 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) { + register const struct ttinfo * const ttisp = &sp->ttis[i]; + char *cp = &sp->chars[ttisp->tt_desigidx]; + + if (strlen(cp) > TZ_ABBR_MAX_LEN && + strcmp(cp, GRANDPARENTED) != 0) + *(cp + TZ_ABBR_MAX_LEN) = '\0'; + } +} + +/* Input buffer for data read from a compiled tz file. */ +union input_buffer { + /* The first part of the buffer, interpreted as a header. */ + struct tzhead tzhead; + + /* The entire buffer. */ + char buf[2 * sizeof(struct tzhead) + 2 * sizeof(struct state) + + 4 * TZ_MAX_TIMES]; +}; + +/* TZDIR with a trailing '/' rather than a trailing '\0'. */ +static char const tzdirslash[sizeof TZDIR] = TZDIR "/"; + +/* Local storage needed for 'tzloadbody'. */ +union local_storage { + /* The results of analyzing the file's contents after it is opened. */ + struct file_analysis { + /* The input buffer. */ + union input_buffer u; + + /* A temporary state used for parsing a TZ string in the file. */ + struct state st; + } u; + + /* The file name to be opened. */ + char fullname[BIGGEST(sizeof(struct file_analysis), + sizeof tzdirslash + 1024)]; +}; + +/* Load tz data from the file named NAME into *SP. Read extended + format if DOEXTEND. Use *LSP for temporary storage. Return 0 on + success, an errno value on failure. */ +static int +tzloadbody(char const *name, struct state *sp, bool doextend, + union local_storage *lsp) +{ + register int i; + register int fid; + register int stored; + register ssize_t nread; + register bool doaccess; + register union input_buffer *up = &lsp->u.u; + register int tzheadsize = sizeof(struct tzhead); + + sp->goback = sp->goahead = false; + + if (! name) { + name = TZDEFAULT; + if (! name) + return EINVAL; + } + + if (name[0] == ':') + ++name; +#ifdef SUPPRESS_TZDIR + /* Do not prepend TZDIR. This is intended for specialized + applications only, due to its security implications. */ + doaccess = true; +#else + doaccess = name[0] == '/'; +#endif + if (!doaccess) { + char const *dot; + size_t namelen = strlen(name); + if (sizeof lsp->fullname - sizeof tzdirslash <= namelen) + return ENAMETOOLONG; + + /* Create a string "TZDIR/NAME". Using sprintf here + would pull in stdio (and would fail if the + resulting string length exceeded INT_MAX!). */ + memcpy(lsp->fullname, tzdirslash, sizeof tzdirslash); + strcpy(lsp->fullname + sizeof tzdirslash, name); + + /* Set doaccess if NAME contains a ".." file name + component, as such a name could read a file outside + the TZDIR virtual subtree. */ + for (dot = name; (dot = strchr(dot, '.')); dot++) + if ((dot == name || dot[-1] == '/') && dot[1] == '.' + && (dot[2] == '/' || !dot[2])) { + doaccess = true; + break; + } + + name = lsp->fullname; + } + if (doaccess && access(name, R_OK) != 0) + return errno; + fid = open(name, OPEN_MODE); + if (fid < 0) + return errno; + + nread = read(fid, up->buf, sizeof up->buf); + if (nread < tzheadsize) { + int err = nread < 0 ? errno : EINVAL; + close(fid); + return err; + } + if (close(fid) < 0) + return errno; + for (stored = 4; stored <= 8; stored *= 2) { + char version = up->tzhead.tzh_version[0]; + bool skip_datablock = stored == 4 && version; + int_fast32_t datablock_size; + int_fast32_t ttisstdcnt = detzcode(up->tzhead.tzh_ttisstdcnt); + int_fast32_t ttisutcnt = detzcode(up->tzhead.tzh_ttisutcnt); + int_fast64_t prevtr = -1; + int_fast32_t prevcorr; + int_fast32_t leapcnt = detzcode(up->tzhead.tzh_leapcnt); + int_fast32_t timecnt = detzcode(up->tzhead.tzh_timecnt); + int_fast32_t typecnt = detzcode(up->tzhead.tzh_typecnt); + int_fast32_t charcnt = detzcode(up->tzhead.tzh_charcnt); + char const *p = up->buf + tzheadsize; + /* Although tzfile(5) currently requires typecnt to be nonzero, + support future formats that may allow zero typecnt + in files that have a TZ string and no transitions. */ + if (! (0 <= leapcnt && leapcnt < TZ_MAX_LEAPS + && 0 <= typecnt && typecnt < TZ_MAX_TYPES + && 0 <= timecnt && timecnt < TZ_MAX_TIMES + && 0 <= charcnt && charcnt < TZ_MAX_CHARS + && 0 <= ttisstdcnt && ttisstdcnt < TZ_MAX_TYPES + && 0 <= ttisutcnt && ttisutcnt < TZ_MAX_TYPES)) + return EINVAL; + datablock_size + = (timecnt * stored /* ats */ + + timecnt /* types */ + + typecnt * 6 /* ttinfos */ + + charcnt /* chars */ + + leapcnt * (stored + 4) /* lsinfos */ + + ttisstdcnt /* ttisstds */ + + ttisutcnt); /* ttisuts */ + if (nread < tzheadsize + datablock_size) + return EINVAL; + if (skip_datablock) + p += datablock_size; + else { + if (! ((ttisstdcnt == typecnt || ttisstdcnt == 0) + && (ttisutcnt == typecnt || ttisutcnt == 0))) + return EINVAL; + + sp->leapcnt = leapcnt; + sp->timecnt = timecnt; + sp->typecnt = typecnt; + sp->charcnt = charcnt; + + /* Read transitions, discarding those out of time_t range. + But pretend the last transition before TIME_T_MIN + occurred at TIME_T_MIN. */ + timecnt = 0; + for (i = 0; i < sp->timecnt; ++i) { + int_fast64_t at + = stored == 4 ? detzcode(p) : detzcode64(p); + sp->types[i] = at <= TIME_T_MAX; + if (sp->types[i]) { + time_t attime + = ((TYPE_SIGNED(time_t) ? at < TIME_T_MIN : at < 0) + ? TIME_T_MIN : at); + if (timecnt && attime <= sp->ats[timecnt - 1]) { + if (attime < sp->ats[timecnt - 1]) + return EINVAL; + sp->types[i - 1] = 0; + timecnt--; + } + sp->ats[timecnt++] = attime; + } + p += stored; + } + + timecnt = 0; + for (i = 0; i < sp->timecnt; ++i) { + unsigned char typ = *p++; + if (sp->typecnt <= typ) + return EINVAL; + if (sp->types[i]) + sp->types[timecnt++] = typ; + } + sp->timecnt = timecnt; + for (i = 0; i < sp->typecnt; ++i) { + register struct ttinfo * ttisp; + unsigned char isdst, desigidx; + + ttisp = &sp->ttis[i]; + ttisp->tt_utoff = detzcode(p); + p += 4; + isdst = *p++; + if (! (isdst < 2)) + return EINVAL; + ttisp->tt_isdst = isdst; + desigidx = *p++; + if (! (desigidx < sp->charcnt)) + return EINVAL; + ttisp->tt_desigidx = desigidx; + } + for (i = 0; i < sp->charcnt; ++i) + sp->chars[i] = *p++; + /* Ensure '\0'-terminated, and make it safe to call + ttunspecified later. */ + memset(&sp->chars[i], 0, CHARS_EXTRA); + + /* Read leap seconds, discarding those out of time_t range. */ + leapcnt = 0; + for (i = 0; i < sp->leapcnt; ++i) { + int_fast64_t tr = stored == 4 ? detzcode(p) : detzcode64(p); + int_fast32_t corr = detzcode(p + stored); + p += stored + 4; + + /* Leap seconds cannot occur before the Epoch, + or out of order. */ + if (tr <= prevtr) + return EINVAL; + + /* To avoid other botches in this code, each leap second's + correction must differ from the previous one's by 1 + second or less, except that the first correction can be + any value; these requirements are more generous than + RFC 8536, to allow future RFC extensions. */ + if (! (i == 0 + || (prevcorr < corr + ? corr == prevcorr + 1 + : (corr == prevcorr + || corr == prevcorr - 1)))) + return EINVAL; + prevtr = tr; + prevcorr = corr; + + if (tr <= TIME_T_MAX) { + sp->lsis[leapcnt].ls_trans = tr; + sp->lsis[leapcnt].ls_corr = corr; + leapcnt++; + } + } + sp->leapcnt = leapcnt; + + for (i = 0; i < sp->typecnt; ++i) { + register struct ttinfo * ttisp; + + ttisp = &sp->ttis[i]; + if (ttisstdcnt == 0) + ttisp->tt_ttisstd = false; + else { + if (*p != true && *p != false) + return EINVAL; + ttisp->tt_ttisstd = *p++; + } + } + for (i = 0; i < sp->typecnt; ++i) { + register struct ttinfo * ttisp; + + ttisp = &sp->ttis[i]; + if (ttisutcnt == 0) + ttisp->tt_ttisut = false; + else { + if (*p != true && *p != false) + return EINVAL; + ttisp->tt_ttisut = *p++; + } + } + } + + nread -= p - up->buf; + memmove(up->buf, p, nread); + + /* If this is an old file, we're done. */ + if (!version) + break; + } + if (doextend && nread > 2 && + up->buf[0] == '\n' && up->buf[nread - 1] == '\n' && + sp->typecnt + 2 <= TZ_MAX_TYPES) { + struct state *ts = &lsp->u.st; + + up->buf[nread - 1] = '\0'; + if (tzparse(&up->buf[1], ts, sp)) { + + /* Attempt to reuse existing abbreviations. + Without this, America/Anchorage would be right on + the edge after 2037 when TZ_MAX_CHARS is 50, as + sp->charcnt equals 40 (for LMT AST AWT APT AHST + AHDT YST AKDT AKST) and ts->charcnt equals 10 + (for AKST AKDT). Reusing means sp->charcnt can + stay 40 in this example. */ + int gotabbr = 0; + int charcnt = sp->charcnt; + for (i = 0; i < ts->typecnt; i++) { + char *tsabbr = ts->chars + ts->ttis[i].tt_desigidx; + int j; + for (j = 0; j < charcnt; j++) + if (strcmp(sp->chars + j, tsabbr) == 0) { + ts->ttis[i].tt_desigidx = j; + gotabbr++; + break; + } + if (! (j < charcnt)) { + int tsabbrlen = strlen(tsabbr); + if (j + tsabbrlen < TZ_MAX_CHARS) { + strcpy(sp->chars + j, tsabbr); + charcnt = j + tsabbrlen + 1; + ts->ttis[i].tt_desigidx = j; + gotabbr++; + } + } + } + if (gotabbr == ts->typecnt) { + sp->charcnt = charcnt; + + /* Ignore any trailing, no-op transitions generated + by zic as they don't help here and can run afoul + of bugs in zic 2016j or earlier. */ + while (1 < sp->timecnt + && (sp->types[sp->timecnt - 1] + == sp->types[sp->timecnt - 2])) + sp->timecnt--; + + for (i = 0; + i < ts->timecnt && sp->timecnt < TZ_MAX_TIMES; + i++) { + time_t t = ts->ats[i]; + if (increment_overflow_time(&t, leapcorr(sp, t)) + || (0 < sp->timecnt + && t <= sp->ats[sp->timecnt - 1])) + continue; + sp->ats[sp->timecnt] = t; + sp->types[sp->timecnt] = (sp->typecnt + + ts->types[i]); + sp->timecnt++; + } + for (i = 0; i < ts->typecnt; i++) + sp->ttis[sp->typecnt++] = ts->ttis[i]; + } + } + } + if (sp->typecnt == 0) + return EINVAL; + if (sp->timecnt > 1) { + if (sp->ats[0] <= TIME_T_MAX - SECSPERREPEAT) { + time_t repeatat = sp->ats[0] + SECSPERREPEAT; + int repeattype = sp->types[0]; + for (i = 1; i < sp->timecnt; ++i) + if (sp->ats[i] == repeatat + && typesequiv(sp, sp->types[i], repeattype)) { + sp->goback = true; + break; + } + } + if (TIME_T_MIN + SECSPERREPEAT <= sp->ats[sp->timecnt - 1]) { + time_t repeatat = sp->ats[sp->timecnt - 1] - SECSPERREPEAT; + int repeattype = sp->types[sp->timecnt - 1]; + for (i = sp->timecnt - 2; i >= 0; --i) + if (sp->ats[i] == repeatat + && typesequiv(sp, sp->types[i], repeattype)) { + sp->goahead = true; + break; + } + } + } + + /* Infer sp->defaulttype from the data. Although this default + type is always zero for data from recent tzdb releases, + things are trickier for data from tzdb 2018e or earlier. + + The first set of heuristics work around bugs in 32-bit data + generated by tzdb 2013c or earlier. The workaround is for + zones like Australia/Macquarie where timestamps before the + first transition have a time type that is not the earliest + standard-time type. See: + https://mm.icann.org/pipermail/tz/2013-May/019368.html */ + /* + ** If type 0 does not specify local time, or is unused in transitions, + ** it's the type to use for early times. + */ + for (i = 0; i < sp->timecnt; ++i) + if (sp->types[i] == 0) + break; + i = i < sp->timecnt && ! ttunspecified(sp, 0) ? -1 : 0; + /* + ** 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; + } + /* The next heuristics are for data generated by tzdb 2018e or + earlier, for zones like EST5EDT where the first transition + is to DST. */ + /* + ** 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; + } + } + /* A simple 'sp->defaulttype = 0;' would suffice here if we + didn't have to worry about 2018e-or-earlier data. Even + simpler would be to remove the defaulttype member and just + use 0 in its place. */ + sp->defaulttype = i; + + return 0; +} + +/* Load tz data from the file named NAME into *SP. Read extended + format if DOEXTEND. Return 0 on success, an errno value on failure. */ +static int +tzload(char const *name, struct state *sp, bool doextend) +{ +#ifdef ALL_STATE + union local_storage *lsp = malloc(sizeof *lsp); + if (!lsp) { + return HAVE_MALLOC_ERRNO ? errno : ENOMEM; + } else { + int err = tzloadbody(name, sp, doextend, lsp); + free(lsp); + return err; + } +#else + union local_storage ls; + return tzloadbody(name, sp, doextend, &ls); +#endif +} + +static bool +typesequiv(const struct state *sp, int a, int b) +{ + register bool result; + + if (sp == NULL || + a < 0 || a >= sp->typecnt || + b < 0 || b >= sp->typecnt) + result = false; + else { + register const struct ttinfo * ap = &sp->ttis[a]; + register const struct ttinfo * bp = &sp->ttis[b]; + result = (ap->tt_utoff == bp->tt_utoff + && ap->tt_isdst == bp->tt_isdst + && ap->tt_ttisstd == bp->tt_ttisstd + && ap->tt_ttisut == bp->tt_ttisut + && (strcmp(&sp->chars[ap->tt_desigidx], + &sp->chars[bp->tt_desigidx]) + == 0)); + } + return result; +} + +static const int 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 year_lengths[2] = { + DAYSPERNYEAR, DAYSPERLYEAR +}; + +/* Is C an ASCII digit? */ +static bool +is_digit(char c) +{ + return '0' <= c && c <= '9'; +} + +/* +** Given a pointer into a timezone string, scan until a character that is not +** a valid character in a time zone abbreviation is found. +** Return a pointer to that character. +*/ + +static ATTRIBUTE_PURE const char * +getzname(register const char *strp) +{ + register char c; + + while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' && + c != '+') + ++strp; + return strp; +} + +/* +** Given a pointer into an extended timezone string, scan until the ending +** delimiter of the time zone abbreviation 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 ATTRIBUTE_PURE const char * +getqzname(register const char *strp, const int delim) +{ + register int c; + + while ((c = *strp) != '\0' && c != delim) + ++strp; + return strp; +} + +/* +** Given a pointer into a timezone 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 const char * +getnum(register const char *strp, int *const nump, const int min, const int max) +{ + register char c; + register 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 timezone 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 const char * +getsecs(register const char *strp, int_fast32_t *const secsp) +{ + int num; + int_fast32_t secsperhour = SECSPERHOUR; + + /* + ** '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 * 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 timezone 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 const char * +getoffset(register const char *strp, int_fast32_t *const offsetp) +{ + register bool neg = false; + + if (*strp == '-') { + neg = true; + ++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 timezone 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 const char * +getrule(const char *strp, register struct rule *const 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(const int year, register const struct rule *const rulep, + const int_fast32_t offset) +{ + register bool leapyear; + register int_fast32_t value; + register int i; + int d, m1, yy0, yy1, yy2, dow; + + 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 >= + 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 += mon_lengths[leapyear][i] * SECSPERDAY; + break; + + default: UNREACHABLE(); + } + + /* + ** "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 bool +tzparse(const char *name, struct state *sp, struct state *basep) +{ + const char * stdname; + const char * dstname; + size_t stdlen; + size_t dstlen; + size_t charcnt; + int_fast32_t stdoffset; + int_fast32_t dstoffset; + register char * cp; + register bool load_ok; + time_t atlo = TIME_T_MIN, leaplo = TIME_T_MIN; + + stdname = name; + if (*name == '<') { + name++; + stdname = name; + name = getqzname(name, '>'); + if (*name != '>') + return false; + stdlen = name - stdname; + name++; + } else { + name = getzname(name); + stdlen = name - stdname; + } + if (!stdlen) + return false; + name = getoffset(name, &stdoffset); + if (name == NULL) + return false; + charcnt = stdlen + 1; + if (sizeof sp->chars < charcnt) + return false; + if (basep) { + if (0 < basep->timecnt) + atlo = basep->ats[basep->timecnt - 1]; + load_ok = false; + sp->leapcnt = basep->leapcnt; + memcpy(sp->lsis, basep->lsis, sp->leapcnt * sizeof *sp->lsis); + } else { + load_ok = tzload(TZDEFRULES, sp, false) == 0; + if (!load_ok) + sp->leapcnt = 0; /* So, we're off a little. */ + } + if (0 < sp->leapcnt) + leaplo = sp->lsis[sp->leapcnt - 1].ls_trans; + if (*name != '\0') { + if (*name == '<') { + dstname = ++name; + name = getqzname(name, '>'); + if (*name != '>') + return false; + dstlen = name - dstname; + name++; + } else { + dstname = name; + name = getzname(name); + dstlen = name - dstname; /* length of DST abbr. */ + } + if (!dstlen) + return false; + charcnt += dstlen + 1; + if (sizeof sp->chars < charcnt) + return false; + if (*name != '\0' && *name != ',' && *name != ';') { + name = getoffset(name, &dstoffset); + if (name == NULL) + return false; + } else dstoffset = stdoffset - SECSPERHOUR; + if (*name == '\0' && !load_ok) + name = TZDEFRULESTRING; + if (*name == ',' || *name == ';') { + struct rule start; + struct rule end; + register int year; + register int timecnt; + time_t janfirst; + int_fast32_t janoffset = 0; + int yearbeg, yearlim; + + ++name; + if ((name = getrule(name, &start)) == NULL) + return false; + if (*name++ != ',') + return false; + if ((name = getrule(name, &end)) == NULL) + return false; + if (*name != '\0') + return false; + sp->typecnt = 2; /* standard time and DST */ + /* + ** Two transitions per year, from EPOCH_YEAR forward. + */ + init_ttinfo(&sp->ttis[0], -stdoffset, false, 0); + init_ttinfo(&sp->ttis[1], -dstoffset, true, stdlen + 1); + sp->defaulttype = 0; + timecnt = 0; + janfirst = 0; + yearbeg = EPOCH_YEAR; + + do { + int_fast32_t yearsecs + = year_lengths[isleap(yearbeg - 1)] * SECSPERDAY; + yearbeg--; + if (increment_overflow_time(&janfirst, -yearsecs)) { + janoffset = -yearsecs; + break; + } + } while (atlo < janfirst + && EPOCH_YEAR - YEARSPERREPEAT / 2 < yearbeg); + + while (true) { + int_fast32_t yearsecs + = year_lengths[isleap(yearbeg)] * SECSPERDAY; + int yearbeg1 = yearbeg; + time_t janfirst1 = janfirst; + if (increment_overflow_time(&janfirst1, yearsecs) + || increment_overflow(&yearbeg1, 1) + || atlo <= janfirst1) + break; + yearbeg = yearbeg1; + janfirst = janfirst1; + } + + yearlim = yearbeg; + if (increment_overflow(&yearlim, YEARSPERREPEAT + 1)) + yearlim = INT_MAX; + for (year = yearbeg; year < yearlim; year++) { + int_fast32_t + starttime = transtime(year, &start, stdoffset), + endtime = transtime(year, &end, dstoffset); + int_fast32_t + yearsecs = (year_lengths[isleap(year)] + * SECSPERDAY); + bool reversed = endtime < starttime; + if (reversed) { + int_fast32_t swap = starttime; + starttime = endtime; + endtime = swap; + } + if (reversed + || (starttime < endtime + && endtime - starttime < yearsecs)) { + if (TZ_MAX_TIMES - 2 < timecnt) + break; + sp->ats[timecnt] = janfirst; + if (! increment_overflow_time + (&sp->ats[timecnt], + janoffset + starttime) + && atlo <= sp->ats[timecnt]) + sp->types[timecnt++] = !reversed; + sp->ats[timecnt] = janfirst; + if (! increment_overflow_time + (&sp->ats[timecnt], + janoffset + endtime) + && atlo <= sp->ats[timecnt]) { + sp->types[timecnt++] = reversed; + } + } + if (endtime < leaplo) { + yearlim = year; + if (increment_overflow(&yearlim, + YEARSPERREPEAT + 1)) + yearlim = INT_MAX; + } + if (increment_overflow_time + (&janfirst, janoffset + yearsecs)) + break; + janoffset = 0; + } + sp->timecnt = timecnt; + if (! timecnt) { + sp->ttis[0] = sp->ttis[1]; + sp->typecnt = 1; /* Perpetual DST. */ + } else if (YEARSPERREPEAT < year - yearbeg) + sp->goback = sp->goahead = true; + } else { + register int_fast32_t theirstdoffset; + register int_fast32_t theirdstoffset; + register int_fast32_t theiroffset; + register bool isdst; + register int i; + register int j; + + if (*name != '\0') + return false; + /* + ** 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_utoff; + 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_utoff; + break; + } + } + /* + ** Initially we're assumed to be in standard time. + */ + isdst = false; + /* + ** 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_ttisut) { + /* No adjustment to transition time */ + } else { + /* + ** If daylight saving time is in + ** effect, and the transition time was + ** not specified as standard time, add + ** the daylight saving 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_utoff; + if (sp->ttis[j].tt_isdst) + theirdstoffset = theiroffset; + else theirstdoffset = theiroffset; + } + /* + ** Finally, fill in ttis. + */ + init_ttinfo(&sp->ttis[0], -stdoffset, false, 0); + init_ttinfo(&sp->ttis[1], -dstoffset, true, stdlen + 1); + sp->typecnt = 2; + sp->defaulttype = 0; + } + } else { + dstlen = 0; + sp->typecnt = 1; /* only standard time */ + sp->timecnt = 0; + init_ttinfo(&sp->ttis[0], -stdoffset, false, 0); + sp->defaulttype = 0; + } + sp->charcnt = charcnt; + cp = sp->chars; + memcpy(cp, stdname, stdlen); + cp += stdlen; + *cp++ = '\0'; + if (dstlen != 0) { + memcpy(cp, dstname, dstlen); + *(cp + dstlen) = '\0'; + } + return true; +} + +static void +gmtload(struct state *const sp) +{ + if (tzload(gmt, sp, true) != 0) + tzparse("GMT0", sp, NULL); +} + +/* Initialize *SP to a value appropriate for the TZ setting NAME. + Return 0 on success, an errno value on failure. */ +static int +zoneinit(struct state *sp, char const *name) +{ + if (name && ! name[0]) { + /* + ** User wants it fast rather than right. + */ + sp->leapcnt = 0; /* so, we're off a little */ + sp->timecnt = 0; + sp->typecnt = 0; + sp->charcnt = 0; + sp->goback = sp->goahead = false; + init_ttinfo(&sp->ttis[0], 0, false, 0); + strcpy(sp->chars, gmt); + sp->defaulttype = 0; + return 0; + } else { + int err = tzload(name, sp, true); + if (err != 0 && name && name[0] != ':' && tzparse(name, sp, NULL)) + err = 0; + if (err == 0) + scrub_abbrs(sp); + return err; + } +} + +static void +tzset_unlocked(void) +{ + char const *name = getenv("TZ"); + struct state *sp = lclptr; + int lcl = name ? strlen(name) < sizeof lcl_TZname : -1; + if (lcl < 0 + ? lcl_is_set < 0 + : 0 < lcl_is_set && strcmp(lcl_TZname, name) == 0) + return; +#ifdef ALL_STATE + if (! sp) + lclptr = sp = malloc(sizeof *lclptr); +#endif /* defined ALL_STATE */ + if (sp) { + if (zoneinit(sp, name) != 0) + zoneinit(sp, ""); + if (0 < lcl) + strcpy(lcl_TZname, name); + } + settzname(); + lcl_is_set = lcl; +} + +void +tzset(void) +{ + if (lock() != 0) + return; + tzset_unlocked(); + unlock(); +} + +static void +gmtcheck(void) +{ + static bool gmt_is_set; + if (lock() != 0) + return; + if (! gmt_is_set) { +#ifdef ALL_STATE + gmtptr = malloc(sizeof *gmtptr); +#endif + if (gmtptr) + gmtload(gmtptr); + gmt_is_set = true; + } + unlock(); +} + +#if NETBSD_INSPIRED + +timezone_t +tzalloc(char const *name) +{ + timezone_t sp = malloc(sizeof *sp); + if (sp) { + int err = zoneinit(sp, name); + if (err != 0) { + free(sp); + errno = err; + return NULL; + } + } else if (!HAVE_MALLOC_ERRNO) + errno = ENOMEM; + return sp; +} + +void +tzfree(timezone_t sp) +{ + free(sp); +} + +/* +** NetBSD 6.1.4 has ctime_rz, but omit it because POSIX says ctime and +** ctime_r are obsolescent and have potential security problems that +** ctime_rz would share. Callers can instead use localtime_rz + strftime. +** +** NetBSD 6.1.4 has tzgetname, but omit it because it doesn't work +** in zones with three or more time zone abbreviations. +** Callers can instead use localtime_rz + strftime. +*/ + +#endif + +/* +** 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.) +** +** If successful and SETNAME is nonzero, +** set the applicable parts of tzname, timezone and altzone; +** however, it's OK to omit this step if the timezone is POSIX-compatible, +** since in that case tzset should have already done this step correctly. +** SETNAME's type is intfast32_t for compatibility with gmtsub, +** but it is actually a boolean and its value should be 0 or 1. +*/ + +/*ARGSUSED*/ +static struct tm * +localsub(struct state const *sp, time_t const *timep, int_fast32_t setname, + struct tm *const tmp) +{ + register const struct ttinfo * ttisp; + register int i; + register struct tm * result; + const time_t t = *timep; + + if (sp == NULL) { + /* Don't bother to set tzname etc.; tzset has already done it. */ + return gmtsub(gmtptr, timep, 0, tmp); + } + if ((sp->goback && t < sp->ats[0]) || + (sp->goahead && t > sp->ats[sp->timecnt - 1])) { + time_t newt; + register time_t seconds; + register time_t years; + + if (t < sp->ats[0]) + seconds = sp->ats[0] - t; + else seconds = t - sp->ats[sp->timecnt - 1]; + --seconds; + + /* Beware integer overflow, as SECONDS might + be close to the maximum time_t. */ + years = seconds / SECSPERREPEAT * YEARSPERREPEAT; + seconds = years * AVGSECSPERYEAR; + years += YEARSPERREPEAT; + if (t < sp->ats[0]) + newt = t + seconds + SECSPERREPEAT; + else + newt = t - seconds - SECSPERREPEAT; + + if (newt < sp->ats[0] || + newt > sp->ats[sp->timecnt - 1]) + return NULL; /* "cannot happen" */ + result = localsub(sp, &newt, setname, tmp); + if (result) { + register int_fast64_t newy; + + newy = result->tm_year; + if (t < sp->ats[0]) + newy -= years; + else newy += years; + if (! (INT_MIN <= newy && newy <= INT_MAX)) + return NULL; + result->tm_year = newy; + } + return result; + } + if (sp->timecnt == 0 || t < sp->ats[0]) { + i = sp->defaulttype; + } else { + register int lo = 1; + register int hi = sp->timecnt; + + while (lo < hi) { + register int mid = (lo + hi) >> 1; + + if (t < sp->ats[mid]) + hi = mid; + else lo = mid + 1; + } + i = 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_utoff; + ** timesub(&t, 0L, sp, tmp); + */ + result = timesub(&t, ttisp->tt_utoff, sp, tmp); + if (result) { + result->tm_isdst = ttisp->tt_isdst; +#ifdef TM_ZONE + result->TM_ZONE = (char *) &sp->chars[ttisp->tt_desigidx]; +#endif /* defined TM_ZONE */ + if (setname) + update_tzname_etc(sp, ttisp); + } + return result; +} + +#if NETBSD_INSPIRED + +struct tm * +localtime_rz(struct state *sp, time_t const *timep, struct tm *tmp) +{ + return localsub(sp, timep, 0, tmp); +} + +#endif + +static struct tm * +localtime_tzset(time_t const *timep, struct tm *tmp, bool setname) +{ + int err = lock(); + if (err) { + errno = err; + return NULL; + } + if (setname || !lcl_is_set) + tzset_unlocked(); + tmp = localsub(lclptr, timep, setname, tmp); + unlock(); + return tmp; +} + +struct tm * +localtime(const time_t *timep) +{ + return localtime_tzset(timep, &tm, true); +} + +struct tm * +localtime_r(const time_t *timep, struct tm *tmp) +{ + return localtime_tzset(timep, tmp, false); +} + +/* +** gmtsub is to gmtime as localsub is to localtime. +*/ + +static struct tm * +gmtsub(struct state const *sp, time_t const *timep, int_fast32_t offset, + struct tm *tmp) +{ + register struct tm * result; + + result = timesub(timep, offset, gmtptr, tmp); +#ifdef TM_ZONE + /* + ** Could get fancy here and deliver something such as + ** "+xx" or "-xx" if offset is non-zero, + ** but this is no time for a treasure hunt. + */ + tmp->TM_ZONE = ((char *) + (offset ? wildabbr : gmtptr ? gmtptr->chars : gmt)); +#endif /* defined TM_ZONE */ + return result; +} + +/* +* Re-entrant version of gmtime. +*/ + +struct tm * +gmtime_r(const time_t *timep, struct tm *tmp) +{ + gmtcheck(); + return gmtsub(gmtptr, timep, 0, tmp); +} + +struct tm * +gmtime(const time_t *timep) +{ + return gmtime_r(timep, &tm); +} + +#ifdef STD_INSPIRED + +struct tm * +offtime(const time_t *timep, long offset) +{ + gmtcheck(); + return gmtsub(gmtptr, timep, offset, &tm); +} + +#endif /* defined STD_INSPIRED */ + +/* +** 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 time_t +leaps_thru_end_of_nonneg(time_t y) +{ + return y / 4 - y / 100 + y / 400; +} + +static time_t +leaps_thru_end_of(time_t y) +{ + return (y < 0 + ? -1 - leaps_thru_end_of_nonneg(-1 - y) + : leaps_thru_end_of_nonneg(y)); +} + +static struct tm * +timesub(const time_t *timep, int_fast32_t offset, + const struct state *sp, struct tm *tmp) +{ + register const struct lsinfo * lp; + register time_t tdays; + register const int * ip; + register int_fast32_t corr; + register int i; + int_fast32_t idays, rem, dayoff, dayrem; + time_t y; + + /* If less than SECSPERMIN, the number of seconds since the + most recent positive leap second; otherwise, do not add 1 + to localtime tm_sec because of leap seconds. */ + time_t secs_since_posleap = SECSPERMIN; + + corr = 0; + i = (sp == NULL) ? 0 : sp->leapcnt; + while (--i >= 0) { + lp = &sp->lsis[i]; + if (*timep >= lp->ls_trans) { + corr = lp->ls_corr; + if ((i == 0 ? 0 : lp[-1].ls_corr) < corr) + secs_since_posleap = *timep - lp->ls_trans; + break; + } + } + + /* Calculate the year, avoiding integer overflow even if + time_t is unsigned. */ + tdays = *timep / SECSPERDAY; + rem = *timep % SECSPERDAY; + rem += offset % SECSPERDAY - corr % SECSPERDAY + 3 * SECSPERDAY; + dayoff = offset / SECSPERDAY - corr / SECSPERDAY + rem / SECSPERDAY - 3; + rem %= SECSPERDAY; + /* y = (EPOCH_YEAR + + floor((tdays + dayoff) / DAYSPERREPEAT) * YEARSPERREPEAT), + sans overflow. But calculate against 1570 (EPOCH_YEAR - + YEARSPERREPEAT) instead of against 1970 so that things work + for localtime values before 1970 when time_t is unsigned. */ + dayrem = tdays % DAYSPERREPEAT; + dayrem += dayoff % DAYSPERREPEAT; + y = (EPOCH_YEAR - YEARSPERREPEAT + + ((1 + dayoff / DAYSPERREPEAT + dayrem / DAYSPERREPEAT + - ((dayrem % DAYSPERREPEAT) < 0) + + tdays / DAYSPERREPEAT) + * YEARSPERREPEAT)); + /* idays = (tdays + dayoff) mod DAYSPERREPEAT, sans overflow. */ + idays = tdays % DAYSPERREPEAT; + idays += dayoff % DAYSPERREPEAT + 2 * DAYSPERREPEAT; + idays %= DAYSPERREPEAT; + /* Increase Y and decrease IDAYS until IDAYS is in range for Y. */ + while (year_lengths[isleap(y)] <= idays) { + int tdelta = idays / DAYSPERLYEAR; + int_fast32_t ydelta = tdelta + !tdelta; + time_t newy = y + ydelta; + register int leapdays; + leapdays = leaps_thru_end_of(newy - 1) - + leaps_thru_end_of(y - 1); + idays -= ydelta * DAYSPERNYEAR; + idays -= leapdays; + y = newy; + } + + if (!TYPE_SIGNED(time_t) && y < TM_YEAR_BASE) { + int signed_y = y; + tmp->tm_year = signed_y - TM_YEAR_BASE; + } else if ((!TYPE_SIGNED(time_t) || INT_MIN + TM_YEAR_BASE <= y) + && y - TM_YEAR_BASE <= INT_MAX) + tmp->tm_year = y - TM_YEAR_BASE; + else { + errno = EOVERFLOW; + return NULL; + } + tmp->tm_yday = idays; + /* + ** The "extra" mods below avoid overflow problems. + */ + tmp->tm_wday = (TM_WDAY_BASE + + ((tmp->tm_year % DAYSPERWEEK) + * (DAYSPERNYEAR % DAYSPERWEEK)) + + leaps_thru_end_of(y - 1) + - leaps_thru_end_of(TM_YEAR_BASE - 1) + + idays); + tmp->tm_wday %= DAYSPERWEEK; + if (tmp->tm_wday < 0) + tmp->tm_wday += DAYSPERWEEK; + tmp->tm_hour = rem / SECSPERHOUR; + rem %= SECSPERHOUR; + tmp->tm_min = rem / SECSPERMIN; + tmp->tm_sec = rem % SECSPERMIN; + + /* Use "... ??:??:60" at the end of the localtime minute containing + the second just before the positive leap second. */ + tmp->tm_sec += secs_since_posleap <= tmp->tm_sec; + + ip = 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 = idays + 1; + tmp->tm_isdst = 0; +#ifdef TM_GMTOFF + tmp->TM_GMTOFF = offset; +#endif /* defined TM_GMTOFF */ + return tmp; +} + +char * +ctime(const time_t *timep) +{ +/* +** Section 4.12.3.2 of X3.159-1989 requires that +** The ctime function converts the calendar time pointed to by timer +** to local time in the form of a string. It is equivalent to +** asctime(localtime(timer)) +*/ + struct tm *tmp = localtime(timep); + return tmp ? asctime(tmp) : NULL; +} + +char * +ctime_r(const time_t *timep, char *buf) +{ + struct tm mytm; + struct tm *tmp = localtime_r(timep, &mytm); + return tmp ? asctime_r(tmp, buf) : NULL; +} + +/* +** 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). +*/ + +#ifndef WRONG +#define WRONG (-1) +#endif /* !defined WRONG */ + +/* +** Normalize logic courtesy Paul Eggert. +*/ + +static bool +increment_overflow(int *ip, int j) +{ + register int const 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 bool +increment_overflow32(int_fast32_t *const lp, int const m) +{ + register int_fast32_t const l = *lp; + + if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l)) + return true; + *lp += m; + return false; +} + +static bool +increment_overflow_time(time_t *tp, int_fast32_t j) +{ + /* + ** This is like + ** 'if (! (TIME_T_MIN <= *tp + j && *tp + j <= TIME_T_MAX)) ...', + ** except that it does the right thing even if *tp + j would overflow. + */ + if (! (j < 0 + ? (TYPE_SIGNED(time_t) ? TIME_T_MIN - j <= *tp : -1 - j < *tp) + : *tp <= TIME_T_MAX - j)) + return true; + *tp += j; + return false; +} + +static bool +normalize_overflow(int *const tensptr, int *const unitsptr, const int base) +{ + register int tensdelta; + + tensdelta = (*unitsptr >= 0) ? + (*unitsptr / base) : + (-1 - (-1 - *unitsptr) / base); + *unitsptr -= tensdelta * base; + return increment_overflow(tensptr, tensdelta); +} + +static bool +normalize_overflow32(int_fast32_t *tensptr, int *unitsptr, int base) +{ + register int tensdelta; + + tensdelta = (*unitsptr >= 0) ? + (*unitsptr / base) : + (-1 - (-1 - *unitsptr) / base); + *unitsptr -= tensdelta * base; + return increment_overflow32(tensptr, tensdelta); +} + +static int +tmcomp(register const struct tm *const atmp, + register const struct tm *const btmp) +{ + register 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(struct tm *const tmp, + struct tm *(*funcp)(struct state const *, time_t const *, + int_fast32_t, struct tm *), + struct state const *sp, + const int_fast32_t offset, + bool *okayp, + bool do_norm_secs) +{ + register int dir; + register int i, j; + register int saved_seconds; + register int_fast32_t li; + register time_t lo; + register time_t hi; + int_fast32_t y; + time_t newt; + time_t t; + struct tm yourtm, mytm; + + *okayp = false; + yourtm = *tmp; + if (do_norm_secs) { + if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec, + SECSPERMIN)) + return WRONG; + } + if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) + return WRONG; + if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) + return WRONG; + y = yourtm.tm_year; + if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR)) + return WRONG; + /* + ** 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 WRONG; + while (yourtm.tm_mday <= 0) { + if (increment_overflow32(&y, -1)) + return WRONG; + li = y + (1 < yourtm.tm_mon); + yourtm.tm_mday += year_lengths[isleap(li)]; + } + while (yourtm.tm_mday > DAYSPERLYEAR) { + li = y + (1 < yourtm.tm_mon); + yourtm.tm_mday -= year_lengths[isleap(li)]; + if (increment_overflow32(&y, 1)) + return WRONG; + } + for ( ; ; ) { + i = 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 WRONG; + } + } + if (increment_overflow32(&y, -TM_YEAR_BASE)) + return WRONG; + if (! (INT_MIN <= y && y <= INT_MAX)) + return WRONG; + yourtm.tm_year = y; + 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 WRONG; + 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). + */ + lo = TIME_T_MIN; + hi = TIME_T_MAX; + for ( ; ; ) { + t = lo / 2 + hi / 2; + if (t < lo) + t = lo; + else if (t > hi) + t = hi; + if (! funcp(sp, &t, offset, &mytm)) { + /* + ** 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 == TIME_T_MAX) + return WRONG; + ++t; + ++lo; + } else if (t == hi) { + if (t == TIME_T_MIN) + return WRONG; + --t; + --hi; + } + if (lo > hi) + return WRONG; + if (dir > 0) + hi = t; + else lo = t; + continue; + } +#if defined TM_GMTOFF && ! UNINIT_TRAP + if (mytm.TM_GMTOFF != yourtm.TM_GMTOFF + && (yourtm.TM_GMTOFF < 0 + ? (-SECSPERDAY <= yourtm.TM_GMTOFF + && (mytm.TM_GMTOFF <= + (SMALLEST(INT_FAST32_MAX, LONG_MAX) + + yourtm.TM_GMTOFF))) + : (yourtm.TM_GMTOFF <= SECSPERDAY + && ((BIGGEST(INT_FAST32_MIN, LONG_MIN) + + yourtm.TM_GMTOFF) + <= mytm.TM_GMTOFF)))) { + /* MYTM matches YOURTM except with the wrong UT offset. + YOURTM.TM_GMTOFF is plausible, so try it instead. + It's OK if YOURTM.TM_GMTOFF contains uninitialized data, + since the guess gets checked. */ + time_t altt = t; + int_fast32_t diff = mytm.TM_GMTOFF - yourtm.TM_GMTOFF; + if (!increment_overflow_time(&altt, diff)) { + struct tm alttm; + if (funcp(sp, &altt, offset, &alttm) + && alttm.tm_isdst == mytm.tm_isdst + && alttm.TM_GMTOFF == yourtm.TM_GMTOFF + && tmcomp(&alttm, &yourtm) == 0) { + t = altt; + mytm = alttm; + } + } + } +#endif + 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. + */ + if (sp == NULL) + return WRONG; + 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; + if (ttunspecified(sp, j)) + continue; + newt = (t + sp->ttis[j].tt_utoff + - sp->ttis[i].tt_utoff); + if (! funcp(sp, &newt, offset, &mytm)) + continue; + if (tmcomp(&mytm, &yourtm) != 0) + continue; + if (mytm.tm_isdst != yourtm.tm_isdst) + continue; + /* + ** We have a match. + */ + t = newt; + goto label; + } + } + return WRONG; + } +label: + newt = t + saved_seconds; + if ((newt < t) != (saved_seconds < 0)) + return WRONG; + t = newt; + if (funcp(sp, &t, offset, tmp)) + *okayp = true; + return t; +} + +static time_t +time2(struct tm * const tmp, + struct tm *(*funcp)(struct state const *, time_t const *, + int_fast32_t, struct tm *), + struct state const *sp, + const int_fast32_t offset, + bool *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, sp, offset, okayp, false); + return *okayp ? t : time2sub(tmp, funcp, sp, offset, okayp, true); +} + +static time_t +time1(struct tm *const tmp, + struct tm *(*funcp)(struct state const *, time_t const *, + int_fast32_t, struct tm *), + struct state const *sp, + const int_fast32_t offset) +{ + register time_t t; + register int samei, otheri; + register int sameind, otherind; + register int i; + register int nseen; + char seen[TZ_MAX_TYPES]; + unsigned char types[TZ_MAX_TYPES]; + bool okay; + + if (tmp == NULL) { + errno = EINVAL; + return WRONG; + } + if (tmp->tm_isdst > 1) + tmp->tm_isdst = 1; + t = time2(tmp, funcp, sp, offset, &okay); + if (okay) + return t; + if (tmp->tm_isdst < 0) +#ifdef PCTS + /* + ** POSIX Conformance Test Suite code courtesy Grant Sullivan. + */ + tmp->tm_isdst = 0; /* reset to std and try again */ +#else + return t; +#endif /* !defined PCTS */ + /* + ** 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. + */ + if (sp == NULL) + return WRONG; + 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]] && !ttunspecified(sp, 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_utoff + - sp->ttis[samei].tt_utoff); + tmp->tm_isdst = !tmp->tm_isdst; + t = time2(tmp, funcp, sp, offset, &okay); + if (okay) + return t; + tmp->tm_sec -= (sp->ttis[otheri].tt_utoff + - sp->ttis[samei].tt_utoff); + tmp->tm_isdst = !tmp->tm_isdst; + } + } + return WRONG; +} + +static time_t +mktime_tzname(struct state *sp, struct tm *tmp, bool setname) +{ + if (sp) + return time1(tmp, localsub, sp, setname); + else { + gmtcheck(); + return time1(tmp, gmtsub, gmtptr, 0); + } +} + +#if NETBSD_INSPIRED + +time_t +mktime_z(struct state *sp, struct tm *tmp) +{ + return mktime_tzname(sp, tmp, false); +} + +#endif + +time_t +mktime(struct tm *tmp) +{ + time_t t; + int err = lock(); + if (err) { + errno = err; + return -1; + } + tzset_unlocked(); + t = mktime_tzname(lclptr, tmp, true); + unlock(); + return t; +} + +#ifdef STD_INSPIRED + +time_t +timelocal(struct tm *tmp) +{ + if (tmp != NULL) + tmp->tm_isdst = -1; /* in case it wasn't initialized */ + return mktime(tmp); +} + +time_t +timegm(struct tm *tmp) +{ + return timeoff(tmp, 0); +} + +time_t +timeoff(struct tm *tmp, long offset) +{ + if (tmp) + tmp->tm_isdst = 0; + gmtcheck(); + return time1(tmp, gmtsub, gmtptr, offset); +} + +#endif /* defined STD_INSPIRED */ + +static int_fast32_t +leapcorr(struct state const *sp, time_t t) +{ + register struct lsinfo const * lp; + register int i; + + i = sp->leapcnt; + while (--i >= 0) { + lp = &sp->lsis[i]; + if (t >= lp->ls_trans) + return lp->ls_corr; + } + return 0; +} + +/* +** XXX--is the below the right way to conditionalize?? +*/ + +#ifdef STD_INSPIRED + +/* NETBSD_INSPIRED_EXTERN functions are exported to callers if + NETBSD_INSPIRED is defined, and are private otherwise. */ +# if NETBSD_INSPIRED +# define NETBSD_INSPIRED_EXTERN +# else +# define NETBSD_INSPIRED_EXTERN static +# endif + +/* +** IEEE Std 1003.1 (POSIX) says that 536457599 +** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which +** is not the case if we are accounting for leap seconds. +** So, we provide the following conversion routines for use +** when exchanging timestamps with POSIX conforming systems. +*/ + +NETBSD_INSPIRED_EXTERN time_t +time2posix_z(struct state *sp, time_t t) +{ + return t - leapcorr(sp, t); +} + +time_t +time2posix(time_t t) +{ + int err = lock(); + if (err) { + errno = err; + return -1; + } + if (!lcl_is_set) + tzset_unlocked(); + if (lclptr) + t = time2posix_z(lclptr, t); + unlock(); + return t; +} + +NETBSD_INSPIRED_EXTERN time_t +posix2time_z(struct state *sp, time_t t) +{ + time_t x; + time_t y; + /* + ** For a positive leap second hit, the result + ** is not unique. For a negative leap second + ** hit, the corresponding time doesn't exist, + ** so we return an adjacent second. + */ + x = t + leapcorr(sp, t); + y = x - leapcorr(sp, x); + if (y < t) { + do { + x++; + y = x - leapcorr(sp, x); + } while (y < t); + x -= y != t; + } else if (y > t) { + do { + --x; + y = x - leapcorr(sp, x); + } while (y > t); + x += y != t; + } + return x; +} + +time_t +posix2time(time_t t) +{ + int err = lock(); + if (err) { + errno = err; + return -1; + } + if (!lcl_is_set) + tzset_unlocked(); + if (lclptr) + t = posix2time_z(lclptr, t); + unlock(); + return t; +} + +#endif /* defined STD_INSPIRED */ + +#if TZ_TIME_T + +# if !USG_COMPAT +# define daylight 0 +# define timezone 0 +# endif +# if !ALTZONE +# define altzone 0 +# endif + +/* Convert from the underlying system's time_t to the ersatz time_tz, + which is called 'time_t' in this file. Typically, this merely + converts the time's integer width. On some platforms, the system + time is local time not UT, or uses some epoch other than the POSIX + epoch. + + Although this code appears to define a function named 'time' that + returns time_t, the macros in private.h cause this code to actually + define a function named 'tz_time' that returns tz_time_t. The call + to sys_time invokes the underlying system's 'time' function. */ + +time_t +time(time_t *p) +{ + time_t r = sys_time(0); + if (r != (time_t) -1) { + int_fast32_t offset = EPOCH_LOCAL ? (daylight ? timezone : altzone) : 0; + if (increment_overflow32(&offset, -EPOCH_OFFSET) + || increment_overflow_time(&r, offset)) { + errno = EOVERFLOW; + r = -1; + } + } + if (p) + *p = r; + return r; +} + +#endif |