/*      $OpenBSD: mount_msdos.c,v 1.36 2022/12/04 23:50:47 cheloha Exp $        */
/*      $NetBSD: mount_msdos.c,v 1.16 1996/10/24 00:12:50 cgd Exp $     */

/*
 * Copyright (c) 1994 Christopher G. Demetriou
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Christopher G. Demetriou.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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/types.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <ctype.h>
#include <err.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <errno.h>

#include "mntopts.h"

const struct mntopt mopts[] = {
        MOPT_STDOPTS,
        MOPT_UPDATE,
        MOPT_ASYNC,
        { NULL }
};

gid_t   a_gid(char *);
uid_t   a_uid(char *);
mode_t  a_mask(char *);
void    usage(void);

int
main(int argc, char **argv)
{
        struct msdosfs_args args;
        struct stat sb;
        int c, mntflags, set_gid, set_uid, set_mask;
        char *dev, dir[PATH_MAX];
        char *errcause;

        mntflags = set_gid = set_uid = set_mask = 0;
        (void)memset(&args, '\0', sizeof(args));

        while ((c = getopt(argc, argv, "sl9u:g:m:o:")) != -1) {
                switch (c) {
                case 's':
                        args.flags |= MSDOSFSMNT_SHORTNAME;
                        break;
                case 'l':
                        args.flags |= MSDOSFSMNT_LONGNAME;
                        break;
                case '9':
                        args.flags |= MSDOSFSMNT_NOWIN95;
                        break;
                case 'u':
                        args.uid = a_uid(optarg);
                        set_uid = 1;
                        break;
                case 'g':
                        args.gid = a_gid(optarg);
                        set_gid = 1;
                        break;
                case 'm':
                        args.mask = a_mask(optarg);
                        set_mask = 1;
                        break;
                case 'o':
                        getmntopts(optarg, mopts, &mntflags);
                        break;
                default:
                        usage();
                        break;
                }
        }

        if (optind + 2 != argc)
                usage();

        dev = argv[optind];
        if (realpath(argv[optind + 1], dir) == NULL)
                err(1, "realpath %s", argv[optind + 1]);

        args.fspec = dev;
        args.export_info.ex_root = -2;  /* unchecked anyway on DOS fs */
        if (mntflags & MNT_RDONLY)
                args.export_info.ex_flags = MNT_EXRDONLY;
        else
                args.export_info.ex_flags = 0;
        if (!set_gid || !set_uid || !set_mask) {
                if (stat(dir, &sb) == -1)
                        err(1, "stat %s", dir);

                if (!set_uid)
                        args.uid = sb.st_uid;
                if (!set_gid)
                        args.gid = sb.st_gid;
                if (!set_mask)
                        args.mask = sb.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO);
        }

        if (mount(MOUNT_MSDOS, dir, mntflags, &args) == -1) {
                switch (errno) {
                case EOPNOTSUPP:
                        errcause = "filesystem not supported by kernel";
                        break;
                case EMFILE:
                        errcause = "mount table full";
                        break;
                case EINVAL:
                        errcause =
                            "not an MSDOS filesystem";
                        break;
                default:
                        errcause = strerror(errno);
                        break;
                }
                errx(1, "%s on %s: %s", args.fspec, dir, errcause);
        }

        exit (0);
}

gid_t
a_gid(char *s)
{
        struct group *gr;
        const char *errstr;
        gid_t gid;

        if ((gr = getgrnam(s)) != NULL)
                return gr->gr_gid;
        gid = strtonum(s, 0, GID_MAX, &errstr);
        if (errstr)
                errx(1, "group is %s: %s", errstr, s);
        return (gid);
}

uid_t
a_uid(char *s)
{
        struct passwd *pw;
        const char *errstr;
        uid_t uid;

        if ((pw = getpwnam(s)) != NULL)
                return pw->pw_uid;
        uid = strtonum(s, 0, UID_MAX, &errstr);
        if (errstr)
                errx(1, "user is %s: %s", errstr, s);
        return (uid);
}

mode_t
a_mask(char *s)
{
        int done, rv;
        char *ep;

        done = 0;
        if (*s >= '0' && *s <= '7') {
                done = 1;
                rv = strtol(optarg, &ep, 8);
        }
        if (!done || rv < 0 || *ep)
                errx(1, "invalid file mode: %s", s);
        return (rv);
}

void
usage(void)
{

        fprintf(stderr,
            "usage: mount_msdos [-9ls] [-g group] [-m mask] [-o options] [-u user] special node\n");
        exit(1);
}