/*      $OpenBSD: vipw.c,v 1.27 2023/08/11 04:45:05 guenther Exp $       */

/*
 * Copyright (c) 1987, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/time.h>
#include <sys/stat.h>

#include <err.h>
#include <fcntl.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <util.h>

void            copyfile(int, int, struct stat *);
__dead void     usage(void);

int
main(int argc, char *argv[])
{
        int pfd, tfd;
        struct stat begin, end;
        int ch;

        while ((ch = getopt(argc, argv, "")) != -1) {
                switch (ch) {
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (argc != 0)
                usage();

        if (unveil(_PATH_MASTERPASSWD_LOCK, "rwc") == -1)
                err(1, "unveil %s", _PATH_MASTERPASSWD_LOCK);
        if (unveil(_PATH_MASTERPASSWD, "r") == -1)
                err(1, "unveil %s",  _PATH_MASTERPASSWD);
        if (unveil(_PATH_BSHELL, "x") == -1)
                err(1, "unveil %s", _PATH_BSHELL);
        if (unveil(_PATH_PWD_MKDB, "x") == -1)
                err(1, "unveil %s", _PATH_PWD_MKDB);
        if (pledge("stdio rpath wpath cpath fattr proc exec", NULL) == -1)
                err(1, "pledge");

        pw_init();
        tfd = pw_lock(0);
        if (tfd == -1)
                errx(1, "the passwd file is busy or you cannot lock.");
        pfd = open(_PATH_MASTERPASSWD, O_RDONLY);
        if (pfd == -1)
                pw_error(_PATH_MASTERPASSWD, 1, 1);
        copyfile(pfd, tfd, &begin);
        (void)close(tfd);

        for (;;) {
                pw_edit(0, NULL);
                if (stat(_PATH_MASTERPASSWD_LOCK, &end))
                        pw_error(_PATH_MASTERPASSWD_LOCK, 1, 1);
                if (timespeccmp(&begin.st_mtim, &end.st_mtim, ==) &&
                    begin.st_size == end.st_size) {
                        warnx("no changes made");
                        pw_error((char *)NULL, 0, 0);
                }
                if (pw_mkdb(NULL, 0) == 0)
                        break;
                pw_prompt();
        }

        return 0;
}

void
copyfile(int from, int to, struct stat *sb)
{
        int nr, nw, off;
        char buf[8*1024];
        struct timespec ts[2];

        if (fstat(from, sb) == -1)
                pw_error(_PATH_MASTERPASSWD, 1, 1);
        while ((nr = read(from, buf, sizeof(buf))) > 0)
                for (off = 0; nr > 0; nr -= nw, off += nw)
                        if ((nw = write(to, buf + off, nr)) == -1)
                                pw_error(_PATH_MASTERPASSWD_LOCK, 1, 1);
        if (nr == -1)
                pw_error(_PATH_MASTERPASSWD, 1, 1);

        ts[0] = sb->st_atim;
        ts[1] = sb->st_mtim;
        (void)futimens(to, ts);
}

__dead void
usage(void)
{
        extern char *__progname;

        (void)fprintf(stderr, "usage: %s\n", __progname);
        exit(1);
}