localtime.c

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2010, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * Most of this code is in the public domain, so clarified as of
 * June 5, 1996 by Arthur David Olson (arthur_david_olson@nih.gov).
 *
 * All modifications to this code to abstract timezones away from
 * the environment are by Tilghman Lesher, <tlesher@vcch.com>, with
 * the copyright assigned to Digium.
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
/*! \file
 *
 * Multi-timezone Localtime code
 *
 * The original source from this file may be obtained from ftp://elsie.nci.nih.gov/pub/
 */
 
/*
** 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.
*/
 
/* #define DEBUG */
 
/*LINTLIBRARY*/
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <signal.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <float.h>
#include <stdlib.h>
#ifdef HAVE_INOTIFY
#include <sys/inotify.h>
#elif defined(HAVE_KQUEUE)
#include <sys/types.h>
#include <sys/time.h>
#include <sys/event.h>
#include <dirent.h>
#include <sys/stat.h>
#include <fcntl.h>
#endif
 
#include "private.h"
#include "tzfile.h"
 
#include "asterisk/_private.h"
#include "asterisk/lock.h"
#include "asterisk/localtime.h"
#include "asterisk/strings.h"
#include "asterisk/linkedlists.h"
#include "asterisk/utils.h"
#include "asterisk/test.h"
 
#ifndef lint
#ifndef NOID
static char __attribute__((unused)) elsieid[] = "@(#)localtime.c    8.5";
#endif /* !defined NOID */
#endif /* !defined lint */
 
#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 */
 
static const char   gmt[] = "GMT";
static const struct timeval WRONG = { 0, 0 };
 
#ifdef TEST_FRAMEWORK
/* Protected from multiple threads by the zonelist lock */
static struct ast_test *test = NULL;
#else
struct ast_test;
#endif
 
/*! \note
 * 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.
 */
#ifndef TZDEFRULESTRING
#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
#endif /* !defined TZDEFDST */
 
/*!< \brief time type information */
struct ttinfo {             /* time type information */
    long        tt_gmtoff;  /* UTC 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 UTC */
};
 
/*! \brief leap second information */
struct lsinfo {             /* leap second information */
    time_t      ls_trans;   /* transition time */
    long        ls_corr;    /* correction to apply */
};
 
#define BIGGEST(a, b)   (((a) > (b)) ? (a) : (b))
 
#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 */
#ifndef TZ_STRLEN_MAX
#define TZ_STRLEN_MAX   255
#endif /* !defined TZ_STRLEN_MAX */
 
struct state {
    /*! Name of the file that this references */
    char    name[TZ_STRLEN_MAX + 1];
    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   ttis[TZ_MAX_TYPES];
    char        chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
                (2 * (MY_TZNAME_MAX + 1)))];
    struct lsinfo   lsis[TZ_MAX_LEAPS];
#ifdef HAVE_INOTIFY
    int wd[2];
#elif defined(HAVE_KQUEUE)
    int fd;
# ifdef HAVE_O_SYMLINK
    int fds;
# else
    DIR *dir;
# endif /* defined(HAVE_O_SYMLINK) */
#else
    time_t  mtime[2];
#endif
    AST_LIST_ENTRY(state) list;
};
 
/* extra initialisation for sstate_alloc() */
#define SP_STACK_FLAG INT_MIN
#ifdef HAVE_INOTIFY
#   define SP_STACK_INIT(sp) do { \
        (sp).wd[0] = SP_STACK_FLAG; \
    } while (0)
#   define SP_STACK_CHECK(sp) ((sp)->wd[0] == SP_STACK_FLAG)
#   define SP_HEAP_INIT(sp) do { \
        (sp)->wd[0] = -1; \
        (sp)->wd[1] = -1; \
    } while (0)
#   define SP_HEAP_FREE(sp) do {} while (0)
 
#elif defined(HAVE_KQUEUE)
#   define SP_STACK_INIT(sp) do { \
        (sp).fd = SP_STACK_FLAG; \
    } while (0)
#   define SP_STACK_CHECK(sp) ((sp)->fd == SP_STACK_FLAG)
#ifdef HAVE_O_SYMLINK
#   define SP_HEAP_INIT(sp) do { \
        (sp)->fd = -1; \
        (sp)->fds = -1; \
    } while (0)
#   define SP_HEAP_FREE(sp) do { \
    if ( (sp) ) { \
        kqueue_daemon_freestate(sp); \
        if ((sp)->fd > -1) { close((sp)->fd); (sp)->fd = -1; } \
        if ((sp)->fds > -1) { close((sp)->fds); (sp)->fds = -1; } \
    } \
    } while (0)
 
#else  /* HAVE_O_SYMLINK */
#   define SP_HEAP_INIT(sp) do { \
        (sp)->fd = -1; \
        (sp)->dir = NULL; \
    } while (0)
#   define SP_HEAP_FREE(sp) do { \
    if ( (sp) ) { \
        kqueue_daemon_freestate(sp); \
        if ((sp)->fd > -1) { close((sp)->fd); (sp)->fd = -1; } \
        if ((sp)->dir != NULL) { closedir((sp)->dir); (sp)->dir = NULL; } \
    } \
    } while (0)
 
#endif /* HAVE_O_SYMLINK */
 
#else  /* defined(HAVE_KQUEUE) */
#   define SP_STACK_INIT(sp) do {} while (0)
#   define SP_STACK_CHECK(sp) (0)
#   define SP_HEAP_INIT(sp) do {} while (0)
#   define SP_HEAP_FREE(sp) do {} while (0)
 
#endif
 
struct locale_entry {
    AST_LIST_ENTRY(locale_entry) list;
    locale_t locale;
    char name[0];
};
 
struct rule {
    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 */
    long        r_time;     /* transition time of rule */
};
 
#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 */
 
/*
** Prototypes for static functions.
*/
 
static long     detzcode P((const char * codep));
static time_t       detzcode64 P((const char * codep));
static int      differ_by_repeat P((time_t t1, time_t t0));
static const char * getzname P((const char * strp));
static const char * getqzname P((const char * strp, const int delim));
static const char * getnum P((const char * strp, int * nump, int min,
                int max));
static const char * getsecs P((const char * strp, long * secsp));
static const char * getoffset P((const char * strp, long * offsetp));
static const char * getrule P((const char * strp, struct rule * rulep));
static int      gmtload P((struct state * sp));
static struct ast_tm *  gmtsub P((const struct timeval * timep, long offset,
                struct ast_tm * tmp));
static struct ast_tm *  localsub P((const struct timeval * timep, long offset,
                struct ast_tm * tmp, const struct state *sp));
static int      increment_overflow P((int * number, int delta));
static int      leaps_thru_end_of P((int y));
static int      long_increment_overflow P((long * number, int delta));
static int      long_normalize_overflow P((long * tensptr,
                int * unitsptr, const int base));
static int      normalize_overflow P((int * tensptr, int * unitsptr,
                const int base));
static struct timeval   time1 P((struct ast_tm * tmp,
                struct ast_tm * (*funcp) P((const struct timeval *,
                long, struct ast_tm *, const struct state *sp)),
                long offset, const struct state *sp));
static struct timeval   time2 P((struct ast_tm *tmp,
                struct ast_tm * (*funcp) P((const struct timeval *,
                long, struct ast_tm*, const struct state *sp)),
                long offset, int * okayp, const struct state *sp));
static struct timeval   time2sub P((struct ast_tm *tmp,
                struct ast_tm * (*funcp) (const struct timeval *,
                long, struct ast_tm*, const struct state *sp),
                long offset, int * okayp, int do_norm_secs, const struct state *sp));
static struct ast_tm *  timesub P((const struct timeval * timep, long offset,
                const struct state * sp, struct ast_tm * tmp));
static int      tmcomp P((const struct ast_tm * atmp,
                const struct ast_tm * btmp));
static time_t       transtime P((time_t janfirst, int year,
                const struct rule * rulep, long offset));
static int      tzload P((const char * name, struct state * sp,
                int doextend));
static int      tzparse P((const char * name, struct state * sp,
                int lastditch));
/* struct state allocator with additional setup as needed */
static struct state *   sstate_alloc(void);
static void     sstate_free(struct state *p);
 
static AST_LIST_HEAD_STATIC(zonelist, state);
#if defined(HAVE_NEWLOCALE) && defined(HAVE_USELOCALE)
static AST_LIST_HEAD_STATIC(localelist, locale_entry);
#endif
 
#ifndef TZ_STRLEN_MAX
#define TZ_STRLEN_MAX 255
#endif /* !defined TZ_STRLEN_MAX */
 
static pthread_t inotify_thread = AST_PTHREADT_NULL;
static ast_cond_t initialization;
static ast_mutex_t initialization_lock;
 
static void add_notify(struct state *sp, const char *path);
 
/*! Start a notification for every entry already in the list. */
static void common_startup(void) {
    struct state *sp;
    AST_LIST_LOCK(&zonelist);
    AST_LIST_TRAVERSE(&zonelist, sp, list) {
        /* ensure sp->name is not relative -- it
         * often is -- otherwise add_notify() fails
         */
        char name[FILENAME_MAX + 1];
 
        if (sp->name[0] == '/') {
            snprintf(name, sizeof(name), "%s", sp->name);
        } else if (!strcmp(sp->name, TZDEFAULT)) {
            snprintf(name, sizeof(name), "/etc/%s", sp->name);
        } else {
            snprintf(name, sizeof(name), "%s/%s", TZDIR, sp->name);
        }
 
        add_notify(sp, name);
    }
    AST_LIST_UNLOCK(&zonelist);
}
 
#ifdef HAVE_INOTIFY
static int inotify_fd = -1;
 
static void *inotify_daemon(void *data)
{
    /* inotify_event is dynamically sized */
    struct inotify_event *iev;
    size_t real_sizeof_iev = sizeof(*iev) + FILENAME_MAX + 1;
    ssize_t res;
    struct state *cur;
 
    inotify_fd = inotify_init();
 
    ast_mutex_lock(&initialization_lock);
    ast_cond_broadcast(&initialization);
    ast_mutex_unlock(&initialization_lock);
 
    if (inotify_fd < 0) {
        ast_log(LOG_ERROR, "Cannot initialize file notification service: %s (%d)\n", strerror(errno), errno);
        inotify_thread = AST_PTHREADT_NULL;
        return NULL;
    }
    iev = ast_alloca(real_sizeof_iev);
 
    common_startup();
 
    for (;/*ever*/;) {
        /* This read should block, most of the time. */
        if ((res = read(inotify_fd, iev, real_sizeof_iev)) < sizeof(*iev) && res > 0) {
            /* This should never happen */
            ast_log(LOG_ERROR, "Inotify read less than a full event (%zd < %zu)?!!\n", res, sizeof(*iev));
            break;
        } else if (res < 0) {
            if (errno == EINTR || errno == EAGAIN) {
                /* If read fails, try again */
                AST_LIST_LOCK(&zonelist);
                ast_cond_broadcast(&initialization);
                AST_LIST_UNLOCK(&zonelist);
                continue;
            }
            /* Sanity check -- this should never happen, either */
            ast_log(LOG_ERROR, "Inotify failed: %s\n", strerror(errno));
            break;
        }
        AST_LIST_LOCK(&zonelist);
        AST_LIST_TRAVERSE_SAFE_BEGIN(&zonelist, cur, list) {
            if (cur->wd[0] == iev->wd || cur->wd[1] == iev->wd) {
                AST_LIST_REMOVE_CURRENT(list);
                sstate_free(cur);
                break;
            }
        }
        AST_LIST_TRAVERSE_SAFE_END
        ast_cond_broadcast(&initialization);
        AST_LIST_UNLOCK(&zonelist);
    }
    close(inotify_fd);
    inotify_thread = AST_PTHREADT_NULL;
    return NULL;
}
 
static void add_notify(struct state *sp, const char *path)
{
    /* watch for flag indicating stack automatic sp,
     * should not be added to watch
     */
    if (SP_STACK_CHECK(sp)) {
        return;
    }
 
    if (inotify_thread == AST_PTHREADT_NULL) {
        ast_cond_init(&initialization, NULL);
        ast_mutex_init(&initialization_lock);
        ast_mutex_lock(&initialization_lock);
        if (!(ast_pthread_create_background(&inotify_thread, NULL, inotify_daemon, NULL))) {
            /* Give the thread a chance to initialize */
            ast_cond_wait(&initialization, &initialization_lock);
        } else {
            fprintf(stderr, "Unable to start notification thread\n");
            ast_mutex_unlock(&initialization_lock);
            return;
        }
        ast_mutex_unlock(&initialization_lock);
    }
 
    if (inotify_fd > -1) {
        char fullpath[FILENAME_MAX + 1] = "";
        if (readlink(path, fullpath, sizeof(fullpath) - 1) != -1) {
            /* If file the symlink points to changes */
            sp->wd[1] = inotify_add_watch(inotify_fd, fullpath, IN_ATTRIB | IN_DELETE_SELF | IN_MODIFY | IN_MOVE_SELF | IN_CLOSE_WRITE );
        } else {
            sp->wd[1] = -1;
        }
        /* or if the symlink itself changes (or the real file is here, if path is not a symlink) */
        sp->wd[0] = inotify_add_watch(inotify_fd, path, IN_ATTRIB | IN_DELETE_SELF | IN_MODIFY | IN_MOVE_SELF | IN_CLOSE_WRITE
#ifdef IN_DONT_FOLLOW   /* Only defined in glibc 2.5 and above */
            | IN_DONT_FOLLOW
#endif
        );
    }
}
#elif defined(HAVE_KQUEUE)
static int queue_fd = -1;
 
/*
 * static struct state *psx_sp and associated code will guard against
 * add_notify() called repeatedly for /usr/share/zoneinfo/posixrules
 * without zonelist check as a result of some errors
 * (any code where tzparse() is called if tzload() fails --
 * tzparse() re-calls tzload() for /usr/share/zoneinfo/posixrules)
 * the pointer itself is guarded by the zonelist lock
 */
static struct state *psx_sp = NULL;
 
/* collect EVFILT_VNODE fflags in macro;
 */
#ifdef NOTE_TRUNCATE
#   define EVVN_NOTES_BITS \
    (NOTE_DELETE|NOTE_WRITE|NOTE_EXTEND|NOTE_REVOKE|NOTE_ATTRIB \
    |NOTE_RENAME|NOTE_LINK|NOTE_TRUNCATE)
#else
#   define EVVN_NOTES_BITS \
    (NOTE_DELETE|NOTE_WRITE|NOTE_EXTEND|NOTE_REVOKE|NOTE_ATTRIB \
    |NOTE_RENAME|NOTE_LINK)
#endif
 
static void *kqueue_daemon(void *data)
{
    struct kevent kev;
    struct state *sp;
 
    ast_mutex_lock(&initialization_lock);
    if (queue_fd < 0 && (queue_fd = kqueue()) < 0) {
        /* ast_log uses us to format messages, so if we called ast_log, we'd be
         * in for a nasty loop (seen already in testing) */
        fprintf(stderr, "Unable to initialize kqueue(): %s\n", strerror(errno));
        inotify_thread = AST_PTHREADT_NULL;
 
        /* Okay to proceed */
        ast_cond_signal(&initialization);
        ast_mutex_unlock(&initialization_lock);
        return NULL;
    }
 
    ast_cond_signal(&initialization);
    ast_mutex_unlock(&initialization_lock);
 
    common_startup();
 
    for (;/*ever*/;) {
        if (kevent(queue_fd, NULL, 0, &kev, 1, NULL) < 0) {
            AST_LIST_LOCK(&zonelist);
            ast_cond_broadcast(&initialization);
            AST_LIST_UNLOCK(&zonelist);
            continue;
        }
 
        sp = (struct state *) kev.udata;
 
        AST_LIST_LOCK(&zonelist);
        /* see comment near psx_sp in add_notify() */
        if (sp == psx_sp) {
            psx_sp = NULL;
 
            sstate_free(sp);
 
            while ((sp = AST_LIST_REMOVE_HEAD(&zonelist, list))) {
                sstate_free(sp);
            }
        } else {
            AST_LIST_REMOVE(&zonelist, sp, list);
            sstate_free(sp);
        }
 
        /* Just in case the signal was sent late */
        ast_cond_broadcast(&initialization);
        AST_LIST_UNLOCK(&zonelist);
    }
 
    inotify_thread = AST_PTHREADT_NULL;
    return NULL;
}
 
static void kqueue_daemon_freestate(struct state *sp)
{
    struct kevent kev;
    struct timespec no_wait = { 0, 1 };
 
    /*!\note
     * If the file event fired, then the file was removed, so we'll need
     * to reparse the entry.  The directory event is a bit more
     * interesting.  Unfortunately, the queue doesn't contain information
     * about the file that changed (only the directory itself), so unless
     * we kept a record of the directory state before, it's not really
     * possible to know what change occurred.  But if we act paranoid and
     * just purge the associated file, then it will get reparsed, and
     * everything works fine.  It may be more work, but it's a vast
     * improvement over the alternative implementation, which is to stat
     * the file repeatedly in what is essentially a busy loop. */
 
    if (sp->fd > -1) {
        /* If the directory event fired, remove the file event */
        EV_SET(&kev, sp->fd, EVFILT_VNODE, EV_DELETE, 0, 0, NULL);
        kevent(queue_fd, &kev, 1, NULL, 0, &no_wait);
    }
 
#ifdef HAVE_O_SYMLINK
    if (sp->fds > -1) {
        /* If the file event fired, remove the symlink event */
        EV_SET(&kev, sp->fds, EVFILT_VNODE, EV_DELETE, 0, 0, NULL);
        kevent(queue_fd, &kev, 1, NULL, 0, &no_wait);
    }
#else
    if (sp->dir) {
        /* If the file event fired, remove the directory event */
        EV_SET(&kev, dirfd(sp->dir), EVFILT_VNODE, EV_DELETE, 0, 0, NULL);
        kevent(queue_fd, &kev, 1, NULL, 0, &no_wait);
    }
#endif
}
 
static void add_notify(struct state *sp, const char *path)
{
    struct kevent kev;
    struct timespec no_wait = { 0, 1 };
    char   watchdir[PATH_MAX + 1] = "";
 
    /* watch for flag indicating stack automatic sp,
     * should not be added to watch
     */
    if (SP_STACK_CHECK(sp) || sp->fd != -1) {
        return;
    }
 
    /* some errors might cause repeated calls to tzload()
     * for TZDEFRULES more than once if errors repeat,
     * so psx_sp is used to keep just one
     */
    if (!strcmp(path, TZDEFRULES) ||
        !strcmp(path, TZDIR "/" TZDEFRULES)) {
        int lckgot = AST_LIST_TRYLOCK(&zonelist);
 
        if (lckgot) {
            return;
        }
 
        if (psx_sp != NULL ||
           (psx_sp = sstate_alloc()) == NULL) {
            AST_LIST_UNLOCK(&zonelist);
            return;
        }
 
        ast_copy_string(psx_sp->name, TZDIR "/" TZDEFRULES,
            sizeof(psx_sp->name));
        sp = psx_sp;
        AST_LIST_UNLOCK(&zonelist);
    }
 
    if (inotify_thread == AST_PTHREADT_NULL) {
        ast_cond_init(&initialization, NULL);
        ast_mutex_init(&initialization_lock);
        ast_mutex_lock(&initialization_lock);
        if (!(ast_pthread_create_background(&inotify_thread, NULL, kqueue_daemon, NULL))) {
            /* Give the thread a chance to initialize */
            ast_cond_wait(&initialization, &initialization_lock);
        }
        ast_mutex_unlock(&initialization_lock);
    }
 
    if (queue_fd < 0) {
        /* Error already sent */
        return;
    }
 
#ifdef HAVE_O_SYMLINK
    if (readlink(path, watchdir, sizeof(watchdir) - 1) != -1 && (sp->fds = open(path, O_RDONLY | O_SYMLINK
# ifdef HAVE_O_EVTONLY
            | O_EVTONLY
# endif
            )) >= 0) {
        EV_SET(&kev, sp->fds, EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_ONESHOT, EVVN_NOTES_BITS, 0, sp);
        errno = 0;
        if (kevent(queue_fd, &kev, 1, NULL, 0, &no_wait) < 0 && errno != 0) {
            /* According to the API docs, we may get -1 return value, due to the
             * NULL space for a returned event, but errno should be 0 unless
             * there's a real error. Otherwise, kevent will return 0 to indicate
             * that the time limit expired. */
            fprintf(stderr, "Unable to watch '%s': %s\n", path, strerror(errno));
            close(sp->fds);
            sp->fds = -1;
        }
    }
#else
    if (readlink(path, watchdir, sizeof(watchdir) - 1) != -1) {
        /* Special -- watch the directory for changes, because we cannot directly watch a symlink */
        char *slash;
 
        ast_copy_string(watchdir, path, sizeof(watchdir));
 
        if ((slash = strrchr(watchdir, '/'))) {
            *slash = '\0';
        }
        if (!(sp->dir = opendir(watchdir))) {
            fprintf(stderr, "Unable to watch directory with symlink '%s': %s\n", path, strerror(errno));
            goto watch_file;
        }
 
        /*!\note
         * You may be wondering about whether there is a potential conflict
         * with the kqueue interface, because we might be watching the same
         * directory for multiple zones.  The answer is no, because kqueue
         * looks at the descriptor to know if there's a duplicate.  Since we
         * (may) have opened the directory multiple times, each represents a
         * different event, so no replacement of an existing event will occur.
         * Likewise, there's no potential leak of a descriptor.
         */
        EV_SET(&kev, dirfd(sp->dir), EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_ONESHOT,
                EVVN_NOTES_BITS, 0, sp);
        errno = 0;
        if (kevent(queue_fd, &kev, 1, NULL, 0, &no_wait) < 0 && errno != 0) {
            fprintf(stderr, "Unable to watch '%s': %s\n", watchdir, strerror(errno));
            closedir(sp->dir);
            sp->dir = NULL;
        }
    }
 
watch_file:
#endif
 
    if ((sp->fd = open(path, O_RDONLY
# ifdef HAVE_O_EVTONLY
            | O_EVTONLY
# endif
            )) < 0) {
        fprintf(stderr, "Unable to watch '%s' for changes: %s\n", path, strerror(errno));
        return;
    }
 
    EV_SET(&kev, sp->fd, EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_ONESHOT, EVVN_NOTES_BITS, 0, sp);
    errno = 0;
    if (kevent(queue_fd, &kev, 1, NULL, 0, &no_wait) < 0 && errno != 0) {
        /* According to the API docs, we may get -1 return value, due to the
         * NULL space for a returned event, but errno should be 0 unless
         * there's a real error. Otherwise, kevent will return 0 to indicate
         * that the time limit expired. */
        fprintf(stderr, "Unable to watch '%s': %s\n", path, strerror(errno));
        close(sp->fd);
        sp->fd = -1;
    }
}
#else
 
static void *notify_daemon(void *data)
{
    struct stat st, lst;
    struct state *cur;
    struct timespec sixty_seconds = { 60, 0 };
 
    ast_mutex_lock(&initialization_lock);
    ast_cond_broadcast(&initialization);
    ast_mutex_unlock(&initialization_lock);
 
    common_startup();
 
    for (;/*ever*/;) {
        char        fullname[FILENAME_MAX + 1];
 
        nanosleep(&sixty_seconds, NULL);
        AST_LIST_LOCK(&zonelist);
        AST_LIST_TRAVERSE_SAFE_BEGIN(&zonelist, cur, list) {
            char *name = cur->name;
 
            if (name[0] == ':')
                ++name;
            if (name[0] != '/') {
                (void) strcpy(fullname, TZDIR "/");
                (void) strcat(fullname, name);
                name = fullname;
            }
            stat(name, &st);
            lstat(name, &lst);
            if (st.st_mtime > cur->mtime[0] || lst.st_mtime > cur->mtime[1]) {
#ifdef TEST_FRAMEWORK
                if (test) {
                    ast_test_status_update(test, "Removing cached TZ entry '%s' because underlying file changed. (%ld != %ld) or (%ld != %ld)\n", name, st.st_mtime, cur->mtime[0], lst.st_mtime, cur->mtime[1]);
                } else
#endif
                {
                    ast_log(LOG_NOTICE, "Removing cached TZ entry '%s' because underlying file changed.\n", name);
                }
                AST_LIST_REMOVE_CURRENT(list);
                sstate_free(cur);
                continue;
            }
        }
        AST_LIST_TRAVERSE_SAFE_END
        ast_cond_broadcast(&initialization);
        AST_LIST_UNLOCK(&zonelist);
    }
    inotify_thread = AST_PTHREADT_NULL;
    return NULL;
}
 
static void add_notify(struct state *sp, const char *path)
{
    struct stat st;
 
    if (inotify_thread == AST_PTHREADT_NULL) {
        ast_cond_init(&initialization, NULL);
        ast_mutex_init(&initialization_lock);
        ast_mutex_lock(&initialization_lock);
        if (!(ast_pthread_create_background(&inotify_thread, NULL, notify_daemon, NULL))) {
            /* Give the thread a chance to initialize */
            ast_cond_wait(&initialization, &initialization_lock);
        }
        ast_mutex_unlock(&initialization_lock);
    }
 
    stat(path, &st);
    sp->mtime[0] = st.st_mtime;
    lstat(path, &st);
    sp->mtime[1] = st.st_mtime;
}
#endif
 
/*
 * struct state allocator with additional setup as needed
 */
static struct state *sstate_alloc(void)
{
    struct state *p = ast_calloc(1, sizeof(*p));
 
    if (p != NULL) {
        SP_HEAP_INIT(p);
    }
 
    return p;
}
 
static void sstate_free(struct state *p)
{
    SP_HEAP_FREE(p);
    ast_free(p);
}
 
void ast_localtime_wakeup_monitor(struct ast_test *info)
{
    struct timeval wait_now = ast_tvnow();
    struct timespec wait_time = { .tv_sec = wait_now.tv_sec + 2, .tv_nsec = wait_now.tv_usec * 1000 };
 
    if (inotify_thread != AST_PTHREADT_NULL) {
        AST_LIST_LOCK(&zonelist);
#ifdef TEST_FRAMEWORK
        test = info;
#endif
        pthread_kill(inotify_thread, SIGURG);
        ast_cond_timedwait(&initialization, &(&zonelist)->lock, &wait_time);
#ifdef TEST_FRAMEWORK
        test = NULL;
#endif
        AST_LIST_UNLOCK(&zonelist);
    }
}
 
/*! \note
** 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 long detzcode(const char * const codep)
{
    long    result;
    int i;
 
    result = (codep[0] & 0x80) ? ~0L : 0;
    for (i = 0; i < 4; ++i)
        result = (result << 8) | (codep[i] & 0xff);
    return result;
}
 
static time_t detzcode64(const char * const codep)
{
    time_t  result;
    int i;
 
    result = (codep[0] & 0x80) ?  (~(int_fast64_t) 0) : 0;
    for (i = 0; i < 8; ++i)
        result = result * 256 + (codep[i] & 0xff);
    return result;
}
 
static int differ_by_repeat(const time_t t1, const time_t t0)
{
    const long long at1 = t1, at0 = t0;
    if (TYPE_INTEGRAL(time_t) &&
        TYPE_BIT(time_t) - TYPE_SIGNED(time_t) < SECSPERREPEAT_BITS)
            return 0;
    return at1 - at0 == SECSPERREPEAT;
}
 
static int tzload(const char *name, struct state * const sp, const int doextend)
{
    const char *        p;
    int         i;
    int         fid;
    int         stored;
    int         nread;
    union {
        struct tzhead   tzhead;
        char        buf[2 * sizeof(struct tzhead) +
                    2 * sizeof *sp +
                    4 * TZ_MAX_TIMES];
    } u;
 
    if (name == NULL && (name = TZDEFAULT) == NULL)
        return -1;
    {
        int doaccess;
        /*
        ** 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."
        */
        char        fullname[FILENAME_MAX + 1];
 
        if (name[0] == ':')
            ++name;
        doaccess = name[0] == '/';
        if (!doaccess) {
            if ((p = TZDIR) == NULL)
                return -1;
            if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
                return -1;
            (void) strcpy(fullname, p);
            (void) strcat(fullname, "/");
            (void) strcat(fullname, name);
            /*
            ** Set doaccess if '.' (as in "../") shows up in name.
            */
            if (strchr(name, '.') != NULL)
                doaccess = TRUE;
            name = fullname;
        }
        if (doaccess && access(name, R_OK) != 0)
            return -1;
        if ((fid = open(name, OPEN_MODE)) == -1)
            return -1;
        if (ast_fully_booted) {
            /* If we don't wait until Asterisk is fully booted, it's possible
             * that the watcher thread gets started in the parent process,
             * before daemon(3) is called, and the thread won't propagate to
             * the child.  Given that bootup only takes a few seconds, it's
             * reasonable to only start the watcher later. */
            add_notify(sp, name);
        }
    }
    nread = read(fid, u.buf, sizeof u.buf);
    /* comp nread < sizeof u.tzhead against unexpected short files */
    if (close(fid) < 0 || nread < sizeof u.tzhead)
        return -1;
    for (stored = 4; stored <= 8; stored *= 2) {
        int     ttisstdcnt;
        int     ttisgmtcnt;
 
        ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt);
        ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt);
        sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt);
        sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt);
        sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt);
        sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt);
        p = u.tzhead.tzh_charcnt + sizeof u.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))
                return -1;
        if (nread - (p - u.buf) <
            sp->timecnt * stored +      /* ats */
            sp->timecnt +           /* types */
            sp->typecnt * 6 +       /* ttinfos */
            sp->charcnt +           /* chars */
            sp->leapcnt * (stored + 4) +    /* lsinfos */
            ttisstdcnt +            /* ttisstds */
            ttisgmtcnt)         /* ttisgmts */
                return -1;
        for (i = 0; i < sp->timecnt; ++i) {
            sp->ats[i] = (stored == 4) ?
                detzcode(p) : detzcode64(p);
            p += stored;
        }
        for (i = 0; i < sp->timecnt; ++i) {
            sp->types[i] = (unsigned char) *p++;
            if (sp->types[i] >= sp->typecnt)
                return -1;
        }
        for (i = 0; i < sp->typecnt; ++i) {
            struct ttinfo * 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)
                return -1;
            ttisp->tt_abbrind = (unsigned char) *p++;
            if (ttisp->tt_abbrind < 0 ||
                ttisp->tt_abbrind > sp->charcnt)
                    return -1;
        }
        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) {
            struct lsinfo * 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) {
            struct ttinfo * 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)
                        return -1;
            }
        }
        for (i = 0; i < sp->typecnt; ++i) {
            struct ttinfo * 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)
                        return -1;
            }
        }
        /*
        ** Out-of-sort ats should mean we're running on a
        ** signed time_t system but using a data file with
        ** unsigned values (or vice versa).
        */
        for (i = 0; i < sp->timecnt - 2; ++i)
            if (sp->ats[i] > sp->ats[i + 1]) {
                ++i;
                if (TYPE_SIGNED(time_t)) {
                    /*
                    ** Ignore the end (easy).
                    */
                    sp->timecnt = i;
                } else {
                    /*
                    ** Ignore the beginning (harder).
                    */
                    int j;
 
                    for (j = 0; j + i < sp->timecnt; ++j) {
                        sp->ats[j] = sp->ats[j + i];
                        sp->types[j] = sp->types[j + i];
                    }
                    sp->timecnt = j;
                }
                break;
            }
        /*
        ** If this is an old file, we're done.
        */
        if (u.tzhead.tzh_version[0] == '\0')
            break;
        nread -= p - u.buf;
        for (i = 0; i < nread; ++i)
            u.buf[i] = p[i];
        /* next loop iter. will assume at least
           sizeof(struct tzhead) bytes */
        if (nread < sizeof(u.tzhead)) {
            break;
        }
        /*
        ** If this is a narrow integer time_t system, we're done.
        */
        if (stored >= (int) sizeof(time_t) && TYPE_INTEGRAL(time_t))
            break;
    }
    if (doextend && nread > 2 &&
        u.buf[0] == '\n' && u.buf[nread - 1] == '\n' &&
        sp->typecnt + 2 <= TZ_MAX_TYPES) {
            struct state    ts;
            int result;
 
            /* for temporary struct state --
             * macro flags the struct as a stack temp.
             * to prevent use within add_notify()
             */
            SP_STACK_INIT(ts);
 
            u.buf[nread - 1] = '\0';
            result = tzparse(&u.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];
            }
    }
    i = 2 * YEARSPERREPEAT;
    sp->goback = sp->goahead = sp->timecnt > i;
    sp->goback = sp->goback && sp->types[i] == sp->types[0] &&
        differ_by_repeat(sp->ats[i], sp->ats[0]);
    sp->goahead = sp->goahead &&
        sp->types[sp->timecnt - 1] == sp->types[sp->timecnt - 1 - i] &&
        differ_by_repeat(sp->ats[sp->timecnt - 1],
             sp->ats[sp->timecnt - 1 - i]);
    return 0;
}
 
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
};
 
/*! \brief
** 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 const char * getzname(const char *strp)
{
    char    c;
 
    while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
        c != '+')
            ++strp;
    return strp;
}
 
/*! \brief
** 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 const char * getqzname(const char *strp, const int delim)
{
    int c;
 
    while ((c = *strp) != '\0' && c != delim)
        ++strp;
    return strp;
}
 
/*! \brief
** 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 const char *getnum(const char *strp, int *nump, const int min, const 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;
}
 
/*! \brief
** 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 const char *getsecs(const char *strp, long * const 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 * (long) 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;
}
 
/*! \brief
** 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 const char *getoffset(const char *strp, long *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;
}
 
/*! \brief
** 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 const char *getrule(const char *strp, struct rule *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 = getsecs(strp, &rulep->r_time);
    } else  rulep->r_time = 2 * SECSPERHOUR;    /* default = 2:00:00 */
    return strp;
}
 
/*! \brief
** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
** year, a rule, and the offset from UTC at the time that rule takes effect,
** calculate the Epoch-relative time that rule takes effect.
*/
 
static time_t transtime(const time_t janfirst, const int year, const struct rule *rulep, const long offset)
{
    int leapyear;
    time_t  value;
    int i;
    int     d, m1, yy0, yy1, yy2, dow;
 
    INITIALIZE(value);
    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 = janfirst + (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 = janfirst + rulep->r_day * SECSPERDAY;
        break;
 
    case MONTH_NTH_DAY_OF_WEEK:
        /*
        ** Mm.n.d - nth "dth day" of month m.
        */
        value = janfirst;
        for (i = 0; i < rulep->r_mon - 1; ++i)
            value += mon_lengths[leapyear][i] * SECSPERDAY;
 
        /*
        ** 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;
        break;
    }
 
    /*
    ** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
    ** question. To get the Epoch-relative time of the specified local
    ** time on that day, add the transition time and the current offset
    ** from UTC.
    */
    return value + rulep->r_time + offset;
}
 
/*! \note
** Given a POSIX section 8-style TZ string, fill in the rule tables as
** appropriate.
*/
 
static int tzparse(const char *name, struct state *sp, const int lastditch)
{
    const char *            stdname;
    const char *            dstname;
    size_t              stdlen;
    size_t              dstlen;
    long                stdoffset;
    long                dstoffset;
    time_t *        atp;
    unsigned char * typep;
    char *          cp;
    int         load_result;
 
    INITIALIZE(dstname);
    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 start;
            struct rule end;
            int year;
            time_t  janfirst;
            time_t      starttime;
            time_t      endtime;
 
            ++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].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;
            atp = sp->ats;
            typep = sp->types;
            janfirst = 0;
            sp->timecnt = 0;
            for (year = EPOCH_YEAR;
                sp->timecnt + 2 <= TZ_MAX_TIMES;
                ++year) {
                time_t  newfirst;
 
                starttime = transtime(janfirst, year, &start,
                    stdoffset);
                endtime = transtime(janfirst, year, &end,
                    dstoffset);
                if (starttime > endtime) {
                    *atp++ = endtime;
                    *typep++ = 1;   /* DST ends */
                    *atp++ = starttime;
                    *typep++ = 0;   /* DST begins */
                } else {
                    *atp++ = starttime;
                    *typep++ = 0;   /* DST begins */
                    *atp++ = endtime;
                    *typep++ = 1;   /* DST ends */
                }
                sp->timecnt += 2;
                newfirst = janfirst;
                newfirst += year_lengths[isleap(year)] *
                    SECSPERDAY;
                if (newfirst <= janfirst)
                    break;
                janfirst = newfirst;
            }
        } else {
            long    theirstdoffset;
            long    theiroffset;
            int i;
            int j;
 
            if (*name != '\0')
                return -1;
            /*
            ** Initial values of theirstdoffset.
            */
            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;
                }
            }
            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 {
                    /* Add the standard time offset to the transition time. */
                    sp->ats[i] += stdoffset - theirstdoffset;
                }
                theiroffset = -sp->ttis[j].tt_gmtoff;
                if (!sp->ttis[j].tt_isdst) {
                    theirstdoffset = theiroffset;
                }
            }
            /*
            ** Finally, fill in ttis.
            ** ttisstd and ttisgmt need not be handled.
            */
            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;
        }
    } else {
        dstlen = 0;
        sp->typecnt = 1;        /* only standard time */
        sp->timecnt = 0;
        sp->ttis[0].tt_gmtoff = -stdoffset;
        sp->ttis[0].tt_isdst = 0;
        sp->ttis[0].tt_abbrind = 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;
    (void) strncpy(cp, stdname, stdlen);
    cp += stdlen;
    *cp++ = '\0';
    if (dstlen != 0) {
        (void) strncpy(cp, dstname, dstlen);
        *(cp + dstlen) = '\0';
    }
    return 0;
}
 
static int gmtload(struct state *sp)
{
    if (tzload(gmt, sp, TRUE) != 0)
        return tzparse(gmt, sp, TRUE);
    else
        return -1;
}
 
void clean_time_zones(void)
{
    struct state *sp;
 
    AST_LIST_LOCK(&zonelist);
    while ((sp = AST_LIST_REMOVE_HEAD(&zonelist, list))) {
        sstate_free(sp);
    }
    AST_LIST_UNLOCK(&zonelist);
}
 
static const struct state *ast_tzset(const char *zone)
{
    struct state *sp;
 
    if (ast_strlen_zero(zone)) {
#ifdef SOLARIS
        zone = getenv("TZ");
        if (ast_strlen_zero(zone)) {
            zone = "GMT";
        }
#else
        zone = "/etc/localtime";
#endif
    }
 
    AST_LIST_LOCK(&zonelist);
    AST_LIST_TRAVERSE(&zonelist, sp, list) {
        if (!strcmp(sp->name, zone)) {
            AST_LIST_UNLOCK(&zonelist);
            return sp;
        }
    }
 
    if (!(sp = sstate_alloc())) {
        AST_LIST_UNLOCK(&zonelist);
        return NULL;
    }
 
    if (tzload(zone, sp, TRUE) != 0) {
        if (zone[0] == ':' || tzparse(zone, sp, FALSE) != 0)
            (void) gmtload(sp);
    }
    ast_copy_string(sp->name, zone, sizeof(sp->name));
    AST_LIST_INSERT_TAIL(&zonelist, sp, list);
    AST_LIST_UNLOCK(&zonelist);
    return sp;
}
 
/*! \note
** 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 struct ast_tm *localsub(const struct timeval *timep, const long offset, struct ast_tm *tmp, const struct state *sp)
{
    const struct ttinfo *   ttisp;
    int         i;
    struct ast_tm *     result;
    struct timeval  t;
    memcpy(&t, timep, sizeof(t));
 
    if (sp == NULL)
        return gmtsub(timep, offset, tmp);
    if ((sp->goback && t.tv_sec < sp->ats[0]) ||
        (sp->goahead && t.tv_sec > sp->ats[sp->timecnt - 1])) {
            struct timeval  newt = t;
            time_t      seconds;
            time_t      tcycles;
            int_fast64_t    icycles;
 
            if (t.tv_sec < sp->ats[0])
                seconds = sp->ats[0] - t.tv_sec;
            else    seconds = t.tv_sec - sp->ats[sp->timecnt - 1];
            --seconds;
            tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR;
            ++tcycles;
            icycles = tcycles;
            if (tcycles - icycles >= 1 || icycles - tcycles >= 1)
                return NULL;
            seconds = icycles;
            seconds *= YEARSPERREPEAT;
            seconds *= AVGSECSPERYEAR;
            if (t.tv_sec < sp->ats[0])
                newt.tv_sec += seconds;
            else    newt.tv_sec -= seconds;
            if (newt.tv_sec < sp->ats[0] ||
                newt.tv_sec > sp->ats[sp->timecnt - 1])
                    return NULL;    /* "cannot happen" */
            result = localsub(&newt, offset, tmp, sp);
            if (result == tmp) {
                time_t  newy;
 
                newy = tmp->tm_year;
                if (t.tv_sec < sp->ats[0])
                    newy -= icycles * YEARSPERREPEAT;
                else
                    newy += icycles * YEARSPERREPEAT;
                tmp->tm_year = newy;
                if (tmp->tm_year != newy)
                    return NULL;
            }
            return result;
    }
    if (sp->timecnt == 0 || t.tv_sec < sp->ats[0]) {
        i = 0;
        while (sp->ttis[i].tt_isdst) {
            if (++i >= sp->typecnt) {
                i = 0;
                break;
            }
        }
    } else {
        int lo = 1;
        int hi = sp->timecnt;
 
        while (lo < hi) {
            int mid = (lo + hi) >> 1;
 
            if (t.tv_sec < 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;
#ifndef SOLARIS /* Solaris doesn't have this element */
    tmp->tm_gmtoff = ttisp->tt_gmtoff;
#endif
#ifdef TM_ZONE
    tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
#endif /* defined TM_ZONE */
    tmp->tm_usec = timep->tv_usec;
    return result;
}
 
struct ast_tm *ast_localtime(const struct timeval *timep, struct ast_tm *tmp, const char *zone)
{
    const struct state *sp = ast_tzset(zone);
    memset(tmp, 0, sizeof(*tmp));
    return sp ? localsub(timep, 0L, tmp, sp) : NULL;
}
 
/*
** This function provides information about daylight savings time
** for the given timezone.  This includes whether it can determine
** if daylight savings is used for this timezone, the UTC times for
** when daylight savings transitions, and the offset in seconds from
** UTC.
*/
 
void ast_get_dst_info(const time_t * const timep, int *dst_enabled, time_t *dst_start, time_t *dst_end, int *gmt_off, const char * const zone)
{
    int i;
    int transition1 = -1;
    int transition2 = -1;
    time_t      seconds;
    int  bounds_exceeded = 0;
    time_t  t = *timep;
    const struct state *sp;
 
    if (NULL == dst_enabled)
        return;
    *dst_enabled = 0;
 
    if (NULL == dst_start || NULL == dst_end || NULL == gmt_off)
        return;
 
    *gmt_off = 0;
 
    sp = ast_tzset(zone);
    if (NULL == sp)
        return;
 
    /* If the desired time exceeds the bounds of the defined time transitions
    * then give up on determining DST info and simply look for gmt offset
    * This requires that I adjust the given time using increments of Gregorian
    * repeats to place the time within the defined time transitions in the
    * timezone structure.
    */
    if ((sp->goback && t < sp->ats[0]) ||
            (sp->goahead && t > sp->ats[sp->timecnt - 1])) {
        time_t      tcycles;
        int_fast64_t    icycles;
 
        if (t < sp->ats[0])
            seconds = sp->ats[0] - t;
        else    seconds = t - sp->ats[sp->timecnt - 1];
        --seconds;
        tcycles = seconds / YEARSPERREPEAT / AVGSECSPERYEAR;
        ++tcycles;
        icycles = tcycles;
        if (tcycles - icycles >= 1 || icycles - tcycles >= 1)
            return;
        seconds = icycles;
        seconds *= YEARSPERREPEAT;
        seconds *= AVGSECSPERYEAR;
        if (t < sp->ats[0])
            t += seconds;
        else
            t -= seconds;
 
        if (t < sp->ats[0] || t > sp->ats[sp->timecnt - 1])
            return; /* "cannot happen" */
 
        bounds_exceeded = 1;
    }
 
    if (sp->timecnt == 0 || t < sp->ats[0]) {
        /* I have no transition times or I'm before time */
        *dst_enabled = 0;
        /* Find where I can get gmtoff */
        i = 0;
        while (sp->ttis[i].tt_isdst) {
            if (++i >= sp->typecnt) {
                i = 0;
                break;
            }
        }
        *gmt_off = sp->ttis[i].tt_gmtoff;
        return;
    }
 
    for (i = 1; i < sp->timecnt; ++i) {
        if (t < sp->ats[i]) {
            transition1 = sp->types[i - 1];
            transition2 = sp->types[i];
            break;
        }
    }
    /* if I found transition times that do not bounded the given time and these correspond to
        or the bounding zones do not reflect a changes in day light savings, then I do not have dst active */
    if (i >= sp->timecnt || 0 > transition1 || 0 > transition2 ||
            (sp->ttis[transition1].tt_isdst == sp->ttis[transition2].tt_isdst)) {
        *dst_enabled = 0;
        *gmt_off = sp->ttis[sp->types[sp->timecnt -1]].tt_gmtoff;
    } else {
        /* I have valid daylight savings information. */
        if(sp->ttis[transition2].tt_isdst)
            *gmt_off = sp->ttis[transition1].tt_gmtoff;
        else
            *gmt_off = sp->ttis[transition2].tt_gmtoff;
 
        /* If I adjusted the time earlier, indicate that the dst is invalid */
        if (!bounds_exceeded) {
            *dst_enabled = 1;
            /* Determine which of the bounds is the start of daylight savings and which is the end */
            if(sp->ttis[transition2].tt_isdst) {
                *dst_start = sp->ats[i];
                *dst_end = sp->ats[i -1];
            } else {
                *dst_start = sp->ats[i -1];
                *dst_end = sp->ats[i];
            }
        }
    }
    return;
}
 
/*
** gmtsub is to gmtime as localsub is to localtime.
*/
 
static struct ast_tm *gmtsub(const struct timeval *timep, const long offset, struct ast_tm *tmp)
{
    struct ast_tm * result;
    struct state *sp;
 
    AST_LIST_LOCK(&zonelist);
    AST_LIST_TRAVERSE(&zonelist, sp, list) {
        if (!strcmp(sp->name, "UTC"))
            break;
    }
 
    if (!sp) {
        if (!(sp = sstate_alloc())) {
            AST_LIST_UNLOCK(&zonelist);
            return NULL;
        }
        gmtload(sp);
        AST_LIST_INSERT_TAIL(&zonelist, sp, list);
    }
    AST_LIST_UNLOCK(&zonelist);
 
    result = timesub(timep, offset, sp, tmp);
#ifdef TM_ZONE
    /*
    ** Could get fancy here and deliver something such as
    ** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
    ** but this is no time for a treasure hunt.
    */
    if (offset != 0)
        tmp->TM_ZONE = "    ";
    else
        tmp->TM_ZONE = sp->chars;
#endif /* defined TM_ZONE */
    return result;
}
 
/*! \brief
** 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(const int y)
{
    return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
        -(leaps_thru_end_of(-(y + 1)) + 1);
}
 
static struct ast_tm *timesub(const struct timeval *timep, const long offset, const struct state *sp, struct ast_tm *tmp)
{
    const struct lsinfo *   lp;
    time_t          tdays;
    int         idays;  /* unsigned would be so 2003 */
    long            rem;
    int             y;
    const int *     ip;
    long            corr;
    int         hit;
    int         i;
    long    seconds;
 
 
    corr = 0;
    hit = 0;
    i = (sp == NULL) ? 0 : sp->leapcnt;
    while (--i >= 0) {
        lp = &sp->lsis[i];
        if (timep->tv_sec >= lp->ls_trans) {
            if (timep->tv_sec == 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->tv_sec / SECSPERDAY;
    rem = timep->tv_sec - tdays * SECSPERDAY;
    while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
        int     newy;
        time_t  tdelta;
        int idelta;
        int leapdays;
 
        tdelta = tdays / DAYSPERLYEAR;
        idelta = tdelta;
        if (tdelta - idelta >= 1 || idelta - tdelta >= 1)
            return NULL;
        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;
    }
 
    seconds = tdays * SECSPERDAY + 0.5;
    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 += year_lengths[isleap(y)];
    }
    while (idays >= year_lengths[isleap(y)]) {
        idays -= 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 = 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;
#ifdef TM_GMTOFF
    tmp->TM_GMTOFF = offset;
#endif /* defined TM_GMTOFF */
    tmp->tm_usec = timep->tv_usec;
    return tmp;
}
 
/*! \note
** 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).
*/
 
/*! \brief
** Simplified normalize logic courtesy Paul Eggert.
*/
 
static int increment_overflow(int *number, int delta)
{
    int number0;
 
    number0 = *number;
    *number += delta;
    return (*number < number0) != (delta < 0);
}
 
static int long_increment_overflow(long *number, int delta)
{
    long    number0;
 
    number0 = *number;
    *number += delta;
    return (*number < number0) != (delta < 0);
}
 
static int normalize_overflow(int *tensptr, int *unitsptr, const int base)
{
    int tensdelta;
 
    tensdelta = (*unitsptr >= 0) ?
        (*unitsptr / base) :
        (-1 - (-1 - *unitsptr) / base);
    *unitsptr -= tensdelta * base;
    return increment_overflow(tensptr, tensdelta);
}
 
static int long_normalize_overflow(long *tensptr, int *unitsptr, const int base)
{
    int tensdelta;
 
    tensdelta = (*unitsptr >= 0) ?
        (*unitsptr / base) :
        (-1 - (-1 - *unitsptr) / base);
    *unitsptr -= tensdelta * base;
    return long_increment_overflow(tensptr, tensdelta);
}
 
static int tmcomp(const struct ast_tm *atmp, const struct ast_tm *btmp)
{
    int result;
 
    if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
        (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)) == 0)
            result = atmp->tm_usec - btmp->tm_usec;
    return result;
}
 
static struct timeval time2sub(struct ast_tm *tmp, struct ast_tm * (* const funcp) (const struct timeval *, long, struct ast_tm *, const struct state *), const long offset, int *okayp, const int do_norm_secs, const struct state *sp)
{
    int         dir;
    int         i, j;
    int         saved_seconds;
    long            li;
    time_t          lo;
    time_t          hi;
    long                y;
    struct timeval          newt = { 0, 0 };
    struct timeval          t = { 0, 0 };
    struct ast_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 (long_normalize_overflow(&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 (long_increment_overflow(&y, TM_YEAR_BASE))
        return WRONG;
    while (yourtm.tm_mday <= 0) {
        if (long_increment_overflow(&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 (long_increment_overflow(&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 (long_increment_overflow(&y, 1))
                return WRONG;
        }
    }
    if (long_increment_overflow(&y, -TM_YEAR_BASE))
        return WRONG;
    yourtm.tm_year = y;
    if (yourtm.tm_year != y)
        return WRONG;
    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).
    */
    if (!TYPE_SIGNED(time_t)) {
        lo = 0;
        hi = lo - 1;
    } else if (!TYPE_INTEGRAL(time_t)) {
        if (sizeof(time_t) > sizeof(float))
            hi = (time_t) DBL_MAX;
        else    hi = (time_t) FLT_MAX;
        lo = -hi;
    } else {
        lo = 1;
        for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i)
            lo *= 2;
        hi = -(lo + 1);
    }
    for ( ; ; ) {
        t.tv_sec = lo / 2 + hi / 2;
        if (t.tv_sec < lo)
            t.tv_sec = lo;
        else if (t.tv_sec > hi)
            t.tv_sec = hi;
        if ((*funcp)(&t, offset, &mytm, sp) == NULL) {
            /*
            ** Assume that t is too extreme to be represented in
            ** a struct ast_tm; arrange things so that it is less
            ** extreme on the next pass.
            */
            dir = (t.tv_sec > 0) ? 1 : -1;
        } else  dir = tmcomp(&mytm, &yourtm);
        if (dir != 0) {
            if (t.tv_sec == lo) {
                ++t.tv_sec;
                if (t.tv_sec <= lo)
                    return WRONG;
                ++lo;
            } else if (t.tv_sec == hi) {
                --t.tv_sec;
                if (t.tv_sec >= hi)
                    return WRONG;
                --hi;
            }
            if (lo > hi)
                return WRONG;
            if (dir > 0)
                hi = t.tv_sec;
            else    lo = t.tv_sec;
            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.
        */
        /*
        ** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
        */
        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.tv_sec = t.tv_sec + sp->ttis[j].tt_gmtoff -
                    sp->ttis[i].tt_gmtoff;
                if ((*funcp)(&newt, offset, &mytm, sp) == 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 WRONG;
    }
label:
    newt.tv_sec = t.tv_sec + saved_seconds;
    if ((newt.tv_sec < t.tv_sec) != (saved_seconds < 0))
        return WRONG;
    t.tv_sec = newt.tv_sec;
    if ((*funcp)(&t, offset, tmp, sp))
        *okayp = TRUE;
    return t;
}
 
static struct timeval time2(struct ast_tm *tmp, struct ast_tm * (* const funcp) (const struct timeval *, long, struct ast_tm*, const struct state *sp), const long offset, int *okayp, const struct state *sp)
{
    struct timeval  t;
 
    /*! \note
    ** 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, sp);
    return *okayp ? t : time2sub(tmp, funcp, offset, okayp, TRUE, sp);
}
 
static struct timeval time1(struct ast_tm *tmp, struct ast_tm * (* const funcp) (const struct timeval *, long, struct ast_tm *, const struct state *), const long offset, const struct state *sp)
{
    struct timeval          t;
    int         samei, otheri;
    int         sameind, otherind;
    int         i;
    int         nseen;
    int             seen[TZ_MAX_TYPES];
    int             types[TZ_MAX_TYPES];
    int             okay;
 
    if (tmp->tm_isdst > 1)
        tmp->tm_isdst = 1;
    t = time2(tmp, funcp, offset, &okay, sp);
#ifdef PCTS
    /*
    ** PCTS code courtesy Grant Sullivan.
    */
    if (okay)
        return t;
    if (tmp->tm_isdst < 0)
        tmp->tm_isdst = 0;  /* reset to std and try again */
#endif /* defined PCTS */
#ifndef PCTS
    if (okay || tmp->tm_isdst < 0)
        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 ast_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]]) {
            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, sp);
            if (okay)
                return t;
            tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
                    sp->ttis[samei].tt_gmtoff;
            tmp->tm_isdst = !tmp->tm_isdst;
        }
    }
    return WRONG;
}
 
struct timeval ast_mktime(struct ast_tm *tmp, const char *zone)
{
    const struct state *sp;
    if (!(sp = ast_tzset(zone)))
        return WRONG;
    return time1(tmp, localsub, 0L, sp);
}
 
#if defined(HAVE_NEWLOCALE) && defined(HAVE_USELOCALE)
static struct locale_entry *find_by_locale(locale_t locale)
{
    struct locale_entry *cur;
    AST_LIST_TRAVERSE(&localelist, cur, list) {
        if (locale == cur->locale) {
            return cur;
        }
    }
    return NULL;
}
 
static struct locale_entry *find_by_name(const char *name)
{
    struct locale_entry *cur;
    AST_LIST_TRAVERSE(&localelist, cur, list) {
        if (strcmp(name, cur->name) == 0) {
            return cur;
        }
    }
    return NULL;
}
 
static const char *store_by_locale(locale_t prevlocale)
{
    struct locale_entry *cur;
    if (prevlocale == LC_GLOBAL_LOCALE) {
        return NULL;
    } else {
        /* Get a handle for this entry, if any */
        if ((cur = find_by_locale(prevlocale))) {
            return cur->name;
        } else {
            /* Create an entry, so it can be restored later */
            int x;
            cur = NULL;
            AST_LIST_LOCK(&localelist);
            for (x = 0; x < 10000; x++) {
                char name[6];
                snprintf(name, sizeof(name), "%04d", x);
                if (!find_by_name(name)) {
                    if ((cur = ast_calloc(1, sizeof(*cur) + strlen(name) + 1))) {
                        cur->locale = prevlocale;
                        strcpy(cur->name, name); /* SAFE */
                        AST_LIST_INSERT_TAIL(&localelist, cur, list);
                    }
                    break;
                }
            }
            AST_LIST_UNLOCK(&localelist);
            return cur ? cur->name : NULL;
        }
    }
}
 
const char *ast_setlocale(const char *locale)
{
    struct locale_entry *cur;
    locale_t prevlocale = LC_GLOBAL_LOCALE;
 
    if (locale == NULL) {
        return store_by_locale(uselocale(LC_GLOBAL_LOCALE));
    }
 
    AST_LIST_LOCK(&localelist);
    if ((cur = find_by_name(locale))) {
        prevlocale = uselocale(cur->locale);
    }
 
    if (!cur) {
        if ((cur = ast_calloc(1, sizeof(*cur) + strlen(locale) + 1))) {
            cur->locale = newlocale(LC_ALL_MASK, locale, NULL);
            strcpy(cur->name, locale); /* SAFE */
            AST_LIST_INSERT_TAIL(&localelist, cur, list);
            prevlocale = uselocale(cur->locale);
        }
    }
    AST_LIST_UNLOCK(&localelist);
    return store_by_locale(prevlocale);
}
#else
const char *ast_setlocale(const char *unused)
{
    return NULL;
}
#endif
 
int ast_strftime_locale(char *buf, size_t len, const char *tmp, const struct ast_tm *tm, const char *locale)
{
    size_t fmtlen = strlen(tmp) + 1;
    char *format = ast_calloc(1, fmtlen), *fptr = format, *newfmt;
    int decimals = -1, i, res;
    long fraction;
    const char *prevlocale;
 
    buf[0] = '\0';/* Ensure the buffer is initialized. */
    if (!format) {
        return -1;
    }
    for (; *tmp; tmp++) {
        if (*tmp == '%') {
            switch (tmp[1]) {
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
                if (tmp[2] != 'q') {
                    goto defcase;
                }
                decimals = tmp[1] - '0';
                tmp++;
                /* Fall through */
            case 'q': /* Milliseconds */
                if (decimals == -1) {
                    decimals = 3;
                }
 
                /* Juggle some memory to fit the item */
                newfmt = ast_realloc(format, fmtlen + decimals);
                if (!newfmt) {
                    ast_free(format);
                    return -1;
                }
                fptr = fptr - format + newfmt;
                format = newfmt;
                fmtlen += decimals;
 
                /* Reduce the fraction of time to the accuracy needed */
                for (i = 6, fraction = tm->tm_usec; i > decimals; i--) {
                    fraction /= 10;
                }
                fptr += sprintf(fptr, "%0*ld", decimals, fraction);
 
                /* Reset, in case more than one 'q' specifier exists */
                decimals = -1;
                tmp++;
                break;
            default:
                goto defcase;
            }
        } else {
defcase:    *fptr++ = *tmp;
        }
    }
    *fptr = '\0';
#undef strftime
    if (locale) {
        prevlocale = ast_setlocale(locale);
    }
    res = (int)strftime(buf, len, format, (struct tm *)tm);
    if (locale) {
        ast_setlocale(prevlocale);
    }
    ast_free(format);
    return res;
}
 
int ast_strftime(char *buf, size_t len, const char *tmp, const struct ast_tm *tm)
{
    return ast_strftime_locale(buf, len, tmp, tm, NULL);
}
 
char *ast_strptime_locale(const char *s, const char *format, struct ast_tm *tm, const char *locale)
{
    struct tm tm2 = { 0, };
    char *res;
    const char *prevlocale;
 
    prevlocale = ast_setlocale(locale);
    res = strptime(s, format, &tm2);
    ast_setlocale(prevlocale);
    /* ast_time and tm are not the same size - tm is a subset of
     * ast_time.  Hence, the size of tm needs to be used for the
     * memcpy
     */
    memcpy(tm, &tm2, sizeof(tm2));
    tm->tm_usec = 0;
    /* strptime(3) doesn't set .tm_isdst correctly, so to force ast_mktime(3)
     * to deal with it correctly, we set it to -1. */
    tm->tm_isdst = -1;
    return res;
}
 
char *ast_strptime(const char *s, const char *format, struct ast_tm *tm)
{
    return ast_strptime_locale(s, format, tm, NULL);
}