/*
 * Copyright 1996 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby
 * granted, provided that both the above copyright notice and this
 * permission notice appear in all copies, that both the above
 * copyright notice and this permission notice appear in all
 * supporting documentation, and that the name of M.I.T. not be used
 * in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.  M.I.T. makes
 * no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 *
 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Second attempt at a `tzmenu' program, using the separate description
 * files provided in newer tzdata releases.
 */

/*
 * When making changes to parser code, run baseline target, check that there are
 * no unintended changes and commit updated file.
 */

#include <sys/cdefs.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include <sys/fcntl.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/sysctl.h>

#ifdef HAVE_BSDDIALOG
#include <bsddialog.h>
#include <locale.h>
#endif

#define _PATH_ZONETAB           "/usr/share/zoneinfo/zone1970.tab"
#define _PATH_ISO3166           "/usr/share/misc/iso3166"
#define _PATH_ZONEINFO          "/usr/share/zoneinfo"
#define _PATH_LOCALTIME         "/etc/localtime"
#define _PATH_DB                "/var/db/zoneinfo"
#define _PATH_WALL_CMOS_CLOCK   "/etc/wall_cmos_clock"

#ifdef PATH_MAX
#define SILLY_BUFFER_SIZE       (2 * PATH_MAX)
#else
#warning "Somebody needs to fix this to dynamically size this buffer."
#define SILLY_BUFFER_SIZE       2048
#endif

/* special return codes for `fire' actions */
#define DITEM_FAILURE           1

/* flags - returned in upper 16 bits of return status */
#define DITEM_LEAVE_MENU        (1 << 16)
#define DITEM_RECREATE          (1 << 18)

static char     path_zonetab[MAXPATHLEN], path_iso3166[MAXPATHLEN],
                path_zoneinfo[MAXPATHLEN], path_localtime[MAXPATHLEN],
                path_db[MAXPATHLEN], path_wall_cmos_clock[MAXPATHLEN];

static int reallydoit = 1;
static int reinstall = 0;
static char *chrootenv = NULL;

static void     usage(void);
static int      install_zoneinfo(const char *zoneinfo);
static void     message_zoneinfo_file(const char *title, char *prompt);
static int      install_zoneinfo_file(const char *zoneinfo_file);

#ifdef HAVE_BSDDIALOG
static struct bsddialog_conf conf;

/* for use in describing more exotic behaviors */
typedef struct dialogMenuItem {
        char *prompt;
        char *title;
        int (*fire)(struct dialogMenuItem *self);
        void *data;
} dialogMenuItem;

static int
xdialog_menu(char *title, char *cprompt, int item_no, dialogMenuItem *ditems)
{
        int i, result, menurows, choice = 0;
        struct bsddialog_menuitem *listitems;

        /* initialize list items */
        listitems = calloc(item_no + 1, sizeof(struct bsddialog_menuitem));
        if (listitems == NULL)
                errx(1, "Failed to allocate memory in xdialog_menu");
        for (i = 0; i < item_no; i++) {
                listitems[i].prefix = "";
                listitems[i].depth = 0;
                listitems[i].bottomdesc = "";
                listitems[i].on = false;
                listitems[i].name = ditems[i].prompt;
                listitems[i].desc = ditems[i].title;
        }

again:
        conf.title = title;
        menurows = item_no < 16 ? item_no : 16;
        result = bsddialog_menu(&conf, cprompt, BSDDIALOG_AUTOSIZE,
            BSDDIALOG_AUTOSIZE, menurows, item_no, listitems, &choice);
        switch (result) {
        case BSDDIALOG_ESC:
                result = -1;
                break;
        case BSDDIALOG_OK:
                if (ditems[choice].fire != NULL) {
                        int status;

                        status = ditems[choice].fire(ditems + choice);
                        if (status & DITEM_RECREATE) {
                                goto again;
                        }
                }
                result = 0;
                break;
        case BSDDIALOG_CANCEL:
        default:
                result = 1;
                break;
        }

        free(listitems);
        return (result);
}

static int usedialog = 1;

static int      confirm_zone(const char *filename);
static int      continent_country_menu(dialogMenuItem *);
static int      set_zone(dialogMenuItem *);
static int      set_zone_menu(dialogMenuItem *);
static int      set_zone_utc(void);

struct continent {
        dialogMenuItem *menu;
        int             nitems;
};

static struct continent africa, america, antarctica, arctic, asia, atlantic;
static struct continent australia, europe, indian, pacific, utc;

static struct continent_names {
        const char      *name;
        struct continent *continent;
} continent_names[] = {
        { "UTC",        &utc },
        { "Africa",     &africa },
        { "America",    &america },
        { "Antarctica", &antarctica },
        { "Arctic",     &arctic },
        { "Asia",       &asia },
        { "Atlantic",   &atlantic },
        { "Australia",  &australia },
        { "Europe",     &europe },
        { "Indian",     &indian },
        { "Pacific",    &pacific },
};

static struct continent_items {
        char            prompt[3];
        char            title[30];
} continent_items[] = {
        { "0",  "UTC" },
        { "1",  "Africa" },
        { "2",  "America -- North and South" },
        { "3",  "Antarctica" },
        { "4",  "Arctic Ocean" },
        { "5",  "Asia" },
        { "6",  "Atlantic Ocean" },
        { "7",  "Australia" },
        { "8",  "Europe" },
        { "9",  "Indian Ocean" },
        { "10", "Pacific Ocean" },
};

#define NCONTINENTS     \
    (int)((sizeof(continent_items)) / (sizeof(continent_items[0])))
static dialogMenuItem continents[NCONTINENTS];

#define OCEANP(x)       ((x) == 4 || (x) == 6 || (x) == 9 || (x) == 10)

static int
continent_country_menu(dialogMenuItem *continent)
{
        char            title[64], prompt[64];
        struct continent *contp = continent->data;
        int             isocean = OCEANP(continent - continents);
        int             rv;

        if (strcmp(continent->title, "UTC") == 0)
                return (set_zone_utc());

        /* It's amazing how much good grammar really matters... */
        if (!isocean) {
                snprintf(title, sizeof(title), "Countries in %s",
                    continent->title);
                snprintf(prompt, sizeof(prompt), "Select a country or region");
        } else {
                snprintf(title, sizeof(title), "Islands and groups in the %s",
                    continent->title);
                snprintf(prompt, sizeof(prompt), "Select an island or group");
        }

        rv = xdialog_menu(title, prompt, contp->nitems, contp->menu);
        return (rv == 0 ? DITEM_LEAVE_MENU : DITEM_RECREATE);
}

static struct continent *
find_continent(int lineno, const char *name)
{
        char            *cname, *cp;
        int             i;

        /*
         * Both normal (the ones in zone filename, e.g. Europe/Andorra) and
         * override (e.g. Atlantic/) entries should contain '/'.
         */
        cp = strdup(name);
        if (cp == NULL)
                err(1, "strdup");
        cname = strsep(&cp, "/");
        if (cp == NULL)
                errx(1, "%s:%d: invalid entry `%s'", path_zonetab, lineno,
                    cname);

        for (i = 0; i < NCONTINENTS; i++)
                if (strcmp(cname, continent_names[i].name) == 0) {
                        free(cname);
                        return (continent_names[i].continent);
                }

        errx(1, "%s:%d: continent `%s' unknown", path_zonetab, lineno, cname);
}

static const char *
find_continent_name(struct continent *cont)
{
        int             i;

        for (i = 0; i < NCONTINENTS; i++)
                if (cont == continent_names[i].continent)
                        return (continent_names[i].name);
        return ("Unknown");
}

struct country {
        char            *name;
        char            *tlc;
        int             nzones;
        struct continent *override;     /* continent override */
        struct continent *alternate;    /* extra continent */
        TAILQ_HEAD(, zone) zones;
        dialogMenuItem  *submenu;
};

struct zone {
        TAILQ_ENTRY(zone) link;
        char            *descr;
        char            *filename;
        struct continent *continent;
};

/*
 * This is the easiest organization... we use ISO 3166 country codes,
 * of the two-letter variety, so we just size this array to suit.
 * Beats worrying about dynamic allocation.
 */
#define NCOUNTRIES      (26 * 26)
static struct country countries[NCOUNTRIES];

#define CODE2INT(s)     ((s[0] - 'A') * 26 + (s[1] - 'A'))

/*
 * Read the ISO 3166 country code database in _PATH_ISO3166
 * (/usr/share/misc/iso3166).  On error, exit via err(3).
 */
static void
read_iso3166_table(void)
{
        FILE            *fp;
        struct country  *cp;
        size_t          len;
        char            *s, *t, *name;
        int             lineno;

        fp = fopen(path_iso3166, "r");
        if (!fp)
                err(1, "%s", path_iso3166);
        lineno = 0;

        while ((s = fgetln(fp, &len)) != NULL) {
                lineno++;
                if (s[len - 1] != '\n')
                        errx(1, "%s:%d: invalid format", path_iso3166, lineno);
                s[len - 1] = '\0';
                if (s[0] == '#' || strspn(s, " \t") == len - 1)
                        continue;

                /* Isolate the two-letter code. */
                t = strsep(&s, "\t");
                if (t == NULL || strlen(t) != 2)
                        errx(1, "%s:%d: invalid format", path_iso3166, lineno);
                if (t[0] < 'A' || t[0] > 'Z' || t[1] < 'A' || t[1] > 'Z')
                        errx(1, "%s:%d: invalid code `%s'", path_iso3166,
                            lineno, t);

                /* Now skip past the three-letter and numeric codes. */
                name = strsep(&s, "\t");        /* 3-let */
                if (name == NULL || strlen(name) != 3)
                        errx(1, "%s:%d: invalid format", path_iso3166, lineno);
                name = strsep(&s, "\t");        /* numeric */
                if (name == NULL || strlen(name) != 3)
                        errx(1, "%s:%d: invalid format", path_iso3166, lineno);

                name = s;

                cp = &countries[CODE2INT(t)];
                if (cp->name)
                        errx(1, "%s:%d: country code `%s' multiply defined: %s",
                            path_iso3166, lineno, t, cp->name);
                cp->name = strdup(name);
                if (cp->name == NULL)
                        errx(1, "malloc failed");
                cp->tlc = strdup(t);
                if (cp->tlc == NULL)
                        errx(1, "malloc failed");
        }

        fclose(fp);
}

static struct country *
find_country(int lineno, const char *tlc)
{
        struct country  *cp;

        if (strlen(tlc) != 2 ||
            tlc[0] < 'A' || tlc[0] > 'Z' || tlc[1] < 'A' || tlc[1] > 'Z')
                errx(1, "%s:%d: country code `%s' invalid", path_zonetab,
                    lineno, tlc);

        cp = &countries[CODE2INT(tlc)];
        if (cp->name == NULL)
                errx(1, "%s:%d: country code `%s' unknown", path_zonetab,
                    lineno, tlc);

        return (cp);
}

static void
add_cont_to_country(struct country *cp, struct continent *cont)
{
        struct zone     *zp;

        TAILQ_FOREACH(zp, &cp->zones, link) {
                if (zp->continent == cont)
                        return;
        }
        cp->alternate = cont;
}

static void
add_zone_to_country(int lineno, struct country *cp, const char *descr,
    const char *file, struct continent *cont)
{
        struct zone     *zp;

        zp = malloc(sizeof(*zp));
        if (zp == NULL)
                errx(1, "malloc(%zu)", sizeof(*zp));

        if (cp->nzones == 0)
                TAILQ_INIT(&cp->zones);

        if (descr != NULL) {
                zp->descr = strdup(descr);
                if (zp->descr == NULL)
                        errx(1, "malloc failed");
        } else {
                zp->descr = NULL;
        }
        zp->filename = strdup(file);
        if (zp->filename == NULL)
                errx(1, "malloc failed");
        zp->continent = cp->override != NULL ? cp->override : cont;
        TAILQ_INSERT_TAIL(&cp->zones, zp, link);
        cp->nzones++;
}

/*
 * This comparison function intentionally sorts all of the null-named
 * ``countries''---i.e., the codes that don't correspond to a real
 * country---to the end.  Everything else is lexical by country name.
 */
static int
compare_countries(const void *xa, const void *xb)
{
        const struct country *a = xa, *b = xb;

        if (a->name == 0 && b->name == 0)
                return (0);
        if (a->name == 0 && b->name != 0)
                return (1);
        if (b->name == 0)
                return (-1);

        return (strcmp(a->name, b->name));
}

/*
 * This must be done AFTER all zone descriptions are read, since it breaks
 * CODE2INT().
 */
static void
sort_countries(void)
{

        qsort(countries, NCOUNTRIES, sizeof(countries[0]), compare_countries);
}

static void
read_zones(void)
{
        FILE            *fp;
        struct continent *cont;
        struct country  *cp;
        size_t          len;
        char            *line, *country_list, *tlc, *file, *descr;
        char            *p, *q;
        int             lineno;
        int             pass = 1;

        fp = fopen(path_zonetab, "r");
        if (!fp)
                err(1, "%s", path_zonetab);

again:
        lineno = 0;
        while ((line = fgetln(fp, &len)) != NULL) {
                lineno++;
                if (line[len - 1] != '\n')
                        errx(1, "%s:%d: invalid format", path_zonetab, lineno);
                line[len - 1] = '\0';

                switch (pass)
                {
                case 1:
                        /*
                         * First pass: collect overrides, only looking for
                         * single continent ones for the moment.
                         *
                         * zone1970.tab introduced continent overrides in the
                         * following format:
                         *
                         *   #@TLC[,TLC...]<tab>CONTINENT/[,CONTINENT/...]
                         */
                        if (strncmp(line, "#@", strlen("#@")) != 0)
                                continue;
                        line += 2;
                        country_list = strsep(&line, "\t");
                        /* Skip multi-continent overrides */
                        if (strchr(line, ',') != NULL)
                                continue;
                        cont = find_continent(lineno, line);
                        /* Parse and store overrides */
                        while (country_list != NULL) {
                                tlc = strsep(&country_list, ",");
                                cp = find_country(lineno, tlc);
                                cp->override = cont;
                        }
                        break;
                case 2:
                        /* Second pass: parse actual data */
                        if (line[0] == '#')
                                continue;

                        country_list = strsep(&line, "\t");
                        /* coord = */ strsep(&line, "\t");       /* Unused */
                        file = strsep(&line, "\t");
                        cont = find_continent(lineno, file);
                        descr = (line != NULL && *line != '\0') ? line : NULL;

                        while (country_list != NULL) {
                                tlc = strsep(&country_list, ",");
                                cp = find_country(lineno, tlc);
                                add_zone_to_country(lineno, cp, descr, file,
                                    cont);
                        }
                        break;
                case 3:
                        /* Third pass: collect multi-continent overrides */
                        if (strncmp(line, "#@", strlen("#@")) != 0)
                                continue;
                        line += 2;
                        country_list = strsep(&line, "\t");
                        /* Skip single-continent overrides */
                        if (strchr(line, ',') == NULL)
                                continue;
                        while (line != NULL) {
                                cont = find_continent(lineno, line);
                                p = q = strdup(country_list);
                                if (p == NULL)
                                        errx(1, "malloc failed");
                                while (q != NULL) {
                                        tlc = strsep(&q, ",");
                                        cp = find_country(lineno, tlc);
                                        add_cont_to_country(cp, cont);
                                }
                                free(p);
                                strsep(&line, ",");
                        }
                        break;
                }
        }

        if (pass++ < 3) {
                errno = 0;
                rewind(fp);
                if (errno != 0)
                        err(1, "failed to rewind %s", path_zonetab);
                goto again;
        }
        fclose(fp);
}

static void
dump_zonetab(void)
{
        struct country  *cp;
        struct zone     *zp;
        const char *cont;

        for (cp = countries; cp->name != NULL; cp++) {
                printf("%s:%s\n", cp->tlc, cp->name);
                TAILQ_FOREACH(zp, &cp->zones, link) {
                        cont = find_continent_name(zp->continent);
                        printf("  %s:%s\n", cont, zp->filename);
                }
        }
}

static void
make_menus(void)
{
        struct country  *cp;
        struct zone     *zp, *zp2;
        struct continent *cont;
        dialogMenuItem  *dmi;
        int             i;

        /*
         * First, count up all the countries in each continent/ocean.
         * Be careful to count those countries which have multiple zones
         * only once for each.  NB: some countries are in multiple
         * continents/oceans.
         */
        for (cp = countries; cp->name; cp++) {
                if (cp->nzones == 0)
                        continue;
                TAILQ_FOREACH(zp, &cp->zones, link) {
                        cont = zp->continent;
                        for (zp2 = TAILQ_FIRST(&cp->zones);
                            zp2->continent != cont;
                            zp2 = TAILQ_NEXT(zp2, link))
                                ;
                        if (zp2 == zp)
                                zp->continent->nitems++;
                }

                for (i = 0; i < NCONTINENTS; i++) {
                        if (cp->alternate == continent_names[i].continent) {
                                continent_names[i].continent->nitems++;
                        }
                }
        }

        /*
         * Now allocate memory for the country menus and initialize
         * continent menus.  We set nitems back to zero so that we can
         * use it for counting again when we actually build the menus.
         */
        memset(continents, 0, sizeof(continents));
        for (i = 0; i < NCONTINENTS; i++) {
                continent_names[i].continent->menu =
                    malloc(sizeof(dialogMenuItem) *
                    continent_names[i].continent->nitems);
                if (continent_names[i].continent->menu == NULL)
                        errx(1, "malloc for continent menu");
                continent_names[i].continent->nitems = 0;
                continents[i].prompt = continent_items[i].prompt;
                continents[i].title = continent_items[i].title;
                continents[i].fire = continent_country_menu;
                continents[i].data = continent_names[i].continent;
        }

        /*
         * Now that memory is allocated, create the menu items for
         * each continent.  For multiple-zone countries, also create
         * the country's zone submenu.
         */
        for (cp = countries; cp->name; cp++) {
                if (cp->nzones == 0)
                        continue;
                cp->submenu = malloc(cp->nzones * sizeof(*dmi));
                if (cp->submenu == 0)
                        errx(1, "malloc for submenu");
                cp->nzones = 0;
                TAILQ_FOREACH(zp, &cp->zones, link) {
                        cont = zp->continent;
                        dmi = &cp->submenu[cp->nzones];
                        memset(dmi, 0, sizeof(*dmi));
                        asprintf(&dmi->prompt, "%d", ++cp->nzones);
                        dmi->title = zp->descr;
                        dmi->fire = set_zone;
                        dmi->data = zp;

                        for (zp2 = TAILQ_FIRST(&cp->zones);
                            zp2->continent != cont;
                            zp2 = TAILQ_NEXT(zp2, link))
                                ;
                        if (zp2 != zp)
                                continue;

                        dmi = &cont->menu[cont->nitems];
                        memset(dmi, 0, sizeof(*dmi));
                        asprintf(&dmi->prompt, "%d", ++cont->nitems);
                        dmi->title = cp->name;
                        dmi->fire = set_zone_menu;
                        dmi->data = cp;
                }

                if (cp->alternate != NULL) {
                        cont = cp->alternate;
                        dmi = &cont->menu[cont->nitems];
                        memset(dmi, 0, sizeof(*dmi));
                        asprintf(&dmi->prompt, "%d", ++cont->nitems);
                        dmi->title = cp->name;
                        dmi->fire = set_zone_menu;
                        dmi->data = cp;
                }
        }
}

static int
set_zone_menu(dialogMenuItem *dmi)
{
        char            title[64], prompt[64];
        struct country  *cp = dmi->data;
        int             rv;

        /* Short cut -- if there's only one zone, don't post a menu. */
        if (cp->nzones == 1)
                return (cp->submenu[0].fire(&cp->submenu[0]));

        snprintf(title, sizeof(title), "%s Time Zones", cp->name);
        snprintf(prompt, sizeof(prompt),
            "Select a zone which observes the same time as your locality.");
        rv = xdialog_menu(title, prompt, cp->nzones, cp->submenu);
        return (rv != 0 ? DITEM_RECREATE : DITEM_LEAVE_MENU);
}

static int
set_zone_utc(void)
{
        if (!confirm_zone("UTC"))
                return (DITEM_FAILURE | DITEM_RECREATE);

        return (install_zoneinfo("UTC"));
}

static int
confirm_zone(const char *filename)
{
        char            prompt[64];
        time_t          t = time(0);
        struct tm       *tm;
        int             rv;

        setenv("TZ", filename, 1);
        tzset();
        tm = localtime(&t);

        snprintf(prompt, sizeof(prompt),
            "Does the timezone abbreviation `%s' look reasonable?", tm->tm_zone);
        conf.title = "Confirmation";
        rv = (bsddialog_yesno(&conf, prompt, 5, 72) == BSDDIALOG_YES);
        return (rv);
}

static int
set_zone(dialogMenuItem *dmi)
{
        struct zone     *zp = dmi->data;
        int             rv;

        if (!confirm_zone(zp->filename))
                return (DITEM_FAILURE | DITEM_RECREATE);

        rv = install_zoneinfo(zp->filename);
        return (rv);
}

#endif

static void message_zoneinfo_file(const char *title, char *prompt)
{
#ifdef HAVE_BSDDIALOG
        if (usedialog) {
                conf.title = title;
                bsddialog_msgbox(&conf, prompt, 8, 72);
        } else
#endif
                fprintf(stderr, "%s: %s\n", title, prompt);
}

static int
install_zoneinfo_file(const char *zoneinfo_file)
{
        char            prompt[SILLY_BUFFER_SIZE];

#ifdef VERBOSE
        snprintf(prompt, sizeof(prompt), "Creating symbolic link %s to %s",
            path_localtime, zoneinfo_file);
        message_zoneinfo_file("Info", prompt);
#endif

        if (reallydoit) {
                if (access(zoneinfo_file, R_OK) != 0) {
                        snprintf(prompt, sizeof(prompt),
                            "Cannot access %s: %s", zoneinfo_file,
                            strerror(errno));
                        message_zoneinfo_file("Error", prompt);
                        return (DITEM_FAILURE | DITEM_RECREATE);
                }
                if (unlink(path_localtime) < 0 && errno != ENOENT) {
                        snprintf(prompt, sizeof(prompt),
                            "Could not delete %s: %s",
                            path_localtime, strerror(errno));
                        message_zoneinfo_file("Error", prompt);
                        return (DITEM_FAILURE | DITEM_RECREATE);
                }
                if (symlink(zoneinfo_file, path_localtime) < 0) {
                        snprintf(prompt, sizeof(prompt),
                            "Cannot create symbolic link %s to %s: %s",
                            path_localtime, zoneinfo_file,
                            strerror(errno));
                        message_zoneinfo_file("Error", prompt);
                        return (DITEM_FAILURE | DITEM_RECREATE);
                }

#ifdef VERBOSE
                snprintf(prompt, sizeof(prompt),
                    "Created symbolic link from %s to %s", zoneinfo_file,
                    path_localtime);
                message_zoneinfo_file("Done", prompt);
#endif
        } /* reallydoit */

        return (DITEM_LEAVE_MENU);
}

static int
install_zoneinfo(const char *zoneinfo)
{
        int             rv;
        FILE            *f;
        char            path_zoneinfo_file[MAXPATHLEN];

        if ((size_t)snprintf(path_zoneinfo_file, sizeof(path_zoneinfo_file),
            "%s/%s", path_zoneinfo, zoneinfo) >= sizeof(path_zoneinfo_file))
                errx(1, "%s/%s name too long", path_zoneinfo, zoneinfo);
        rv = install_zoneinfo_file(path_zoneinfo_file);

        /* Save knowledge for later */
        if (reallydoit && (rv & DITEM_FAILURE) == 0) {
                if ((f = fopen(path_db, "w")) != NULL) {
                        fprintf(f, "%s\n", zoneinfo);
                        fclose(f);
                }
        }

        return (rv);
}

static void
usage(void)
{

        fprintf(stderr, "usage: tzsetup [-nrs] [-C chroot_directory]"
            " [zoneinfo_file | zoneinfo_name]\n");
        exit(1);
}

int
main(int argc, char **argv)
{
#ifdef HAVE_BSDDIALOG
        char            prompt[128];
        int             fd;
#endif
        int             c, rv, skiputc;
        char            vm_guest[16] = "";
        size_t          len = sizeof(vm_guest);
        char            *dztpath;

        dztpath = NULL;
        skiputc = 0;

#ifdef HAVE_BSDDIALOG
        setlocale(LC_ALL, "");
#endif

        /* Default skiputc to 1 for VM guests */
        if (sysctlbyname("kern.vm_guest", vm_guest, &len, NULL, 0) == 0 &&
            strcmp(vm_guest, "none") != 0)
                skiputc = 1;

        while ((c = getopt(argc, argv, "C:d:nrs")) != -1) {
                switch (c) {
                case 'C':
                        chrootenv = optarg;
                        break;
                case 'd':
                        dztpath = optarg;
                        break;
                case 'n':
                        reallydoit = 0;
                        break;
                case 'r':
                        reinstall = 1;
#ifdef HAVE_BSDDIALOG
                        usedialog = 0;
#endif
                        break;
                case 's':
                        skiputc = 1;
                        break;
                default:
                        usage();
                }
        }

        if (argc - optind > 1)
                usage();

        if (chrootenv == NULL) {
                if (dztpath == NULL)
                        strcpy(path_zonetab, _PATH_ZONETAB);
                else
                        strlcpy(path_zonetab, dztpath, sizeof(path_zonetab));
                strcpy(path_iso3166, _PATH_ISO3166);
                strcpy(path_localtime, _PATH_LOCALTIME);
                strcpy(path_db, _PATH_DB);
                strcpy(path_wall_cmos_clock, _PATH_WALL_CMOS_CLOCK);
        } else {
                sprintf(path_zonetab, "%s/%s", chrootenv, _PATH_ZONETAB);
                sprintf(path_iso3166, "%s/%s", chrootenv, _PATH_ISO3166);
                sprintf(path_localtime, "%s/%s", chrootenv, _PATH_LOCALTIME);
                sprintf(path_db, "%s/%s", chrootenv, _PATH_DB);
                sprintf(path_wall_cmos_clock, "%s/%s", chrootenv,
                    _PATH_WALL_CMOS_CLOCK);
        }
        /* Symlink target is the same regardless of chroot */
        strcpy(path_zoneinfo, _PATH_ZONEINFO);

        /* Override the user-supplied umask. */
        (void)umask(S_IWGRP | S_IWOTH);

        if (reinstall == 1) {
                FILE *f;
                char zoneinfo[MAXPATHLEN];

                if ((f = fopen(path_db, "r")) != NULL) {
                        if (fgets(zoneinfo, sizeof(zoneinfo), f) != NULL) {
                                zoneinfo[sizeof(zoneinfo) - 1] = 0;
                                if (strlen(zoneinfo) > 0) {
                                        zoneinfo[strlen(zoneinfo) - 1] = 0;
                                        rv = install_zoneinfo(zoneinfo);
                                        exit(rv & ~DITEM_LEAVE_MENU);
                                }
                                errx(1, "Error reading %s.\n", path_db);
                        }
                        fclose(f);
                        errx(1,
                            "Unable to determine earlier installed zoneinfo "
                            "name. Check %s", path_db);
                }
                errx(1, "Cannot open %s for reading. Does it exist?", path_db);
        }

        /*
         * If the arguments on the command-line do not specify a file,
         * then interpret it as a zoneinfo name
         */
        if (optind == argc - 1) {
                struct stat sb;

                if (stat(argv[optind], &sb) != 0) {
#ifdef HAVE_BSDDIALOG
                        usedialog = 0;
#endif
                        rv = install_zoneinfo(argv[optind]);
                        exit(rv & ~DITEM_LEAVE_MENU);
                }
                /* FALLTHROUGH */
        }
#ifdef HAVE_BSDDIALOG

        read_iso3166_table();
        read_zones();
        sort_countries();
        if (dztpath != NULL) {
                dump_zonetab();
                return (0);
        }
        make_menus();

        bsddialog_initconf(&conf);
        conf.clear = true;
        conf.auto_minwidth = 24;
        conf.key.enable_esc = true;

        if (bsddialog_init() == BSDDIALOG_ERROR)
                errx(1, "Error bsddialog: %s\n", bsddialog_geterror());

        if (skiputc == 0) {
                snprintf(prompt, sizeof(prompt),
                    "Is this machine's CMOS clock set to UTC?  "
                    "If it is set to local time,\n"
                    "or you don't know, please choose NO here!");

                conf.title = "Select local or UTC (Coordinated Universal Time) clock";
                if (bsddialog_yesno(&conf, prompt, 7, 73) == BSDDIALOG_YES) {
                        if (reallydoit)
                                unlink(path_wall_cmos_clock);
                } else {
                        if (reallydoit) {
                                fd = open(path_wall_cmos_clock,
                                    O_WRONLY | O_CREAT | O_TRUNC,
                                    S_IRUSR | S_IRGRP | S_IROTH);
                                if (fd < 0) {
                                        bsddialog_end();
                                        err(1, "create %s",
                                            path_wall_cmos_clock);
                                }
                                close(fd);
                        }
                }
        }
        if (optind == argc - 1) {
                snprintf(prompt, sizeof(prompt),
                    "\nUse the default `%s' zone?", argv[optind]);
                conf.title = "Default timezone provided";
                if (bsddialog_yesno(&conf, prompt, 7, 72) == BSDDIALOG_YES) {
                        rv = install_zoneinfo_file(argv[optind]);
                        bsddialog_end();
                        exit(rv & ~DITEM_LEAVE_MENU);
                }
        }
        xdialog_menu("Time Zone Selector", "Select a region", NCONTINENTS,
            continents);

        bsddialog_end();
#else
        usage();
#endif
        return (0);
}