/*      $NetBSD: mount_msdos.c,v 1.18 1997/09/16 12:24:18 lukem Exp $   */

/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * 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/param.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/iconv.h>
#include <sys/linker.h>
#include <sys/module.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <grp.h>
#include <locale.h>
#include <mntopts.h>
#include <pwd.h>
#include <stdio.h>
/* must be after stdio to declare fparseln */
#include <libutil.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

static gid_t    a_gid(char *);
static uid_t    a_uid(char *);
static mode_t   a_mask(char *);
static void     usage(void) __dead2;
static int      set_charset(struct iovec **iov, int *iovlen, const char *, const char *);

int
main(int argc, char **argv)
{
        struct iovec *iov = NULL;
        int iovlen = 0;
        struct stat sb;
        int c, set_gid, set_uid, set_mask, set_dirmask;
        char *dev, *dir, mntpath[MAXPATHLEN], *csp;
        char fstype[] = "msdosfs";
        char errmsg[255] = {0};
        char *cs_dos = NULL;
        char *cs_local = NULL;
        mode_t mask = 0, dirmask = 0;
        uid_t uid = 0;
        gid_t gid = 0;

        set_gid = set_uid = set_mask = set_dirmask = 0;

        while ((c = getopt(argc, argv, "sl9u:g:m:M:o:L:D:W:")) != -1) {
                switch (c) {
                case 's':
                        build_iovec(&iov, &iovlen, "shortnames", NULL, (size_t)-1);
                        break;
                case 'l':
                        build_iovec(&iov, &iovlen, "longnames", NULL, (size_t)-1);
                        break;
                case '9':
                        build_iovec_argf(&iov, &iovlen, "nowin95", "", (size_t)-1);
                        break;
                case 'u':
                        uid = a_uid(optarg);
                        set_uid = 1;
                        break;
                case 'g':
                        gid = a_gid(optarg);
                        set_gid = 1;
                        break;
                case 'm':
                        mask = a_mask(optarg);
                        set_mask = 1;
                        break;
                case 'M':
                        dirmask = a_mask(optarg);
                        set_dirmask = 1;
                        break;
                case 'L': {
                        const char *quirk = NULL;
                        if (setlocale(LC_CTYPE, optarg) == NULL)
                                err(EX_CONFIG, "%s", optarg);
                        csp = strchr(optarg,'.');
                        if (!csp)
                                err(EX_CONFIG, "%s", optarg);
                        quirk = kiconv_quirkcs(csp + 1, KICONV_VENDOR_MICSFT);
                        build_iovec_argf(&iov, &iovlen, "cs_local", quirk);
                        cs_local = strdup(quirk);
                        }
                        break;
                case 'D':
                        cs_dos = strdup(optarg);
                        build_iovec_argf(&iov, &iovlen, "cs_dos", cs_dos, (size_t)-1);
                        break;
                case 'o': {
                        char *p = NULL;
                        char *val = strdup("");
                        p = strchr(optarg, '=');
                        if (p != NULL) {
                                free(val);
                                *p = '\0';
                                val = p + 1;
                        }
                        build_iovec(&iov, &iovlen, optarg, val, (size_t)-1);
                        }
                        break;
                case 'W':
                        if (strcmp(optarg, "iso22dos") == 0) {
                                cs_local = strdup("ISO8859-2");
                                cs_dos = strdup("CP852");
                        } else if (strcmp(optarg, "iso72dos") == 0) {
                                cs_local = strdup("ISO8859-7");
                                cs_dos = strdup("CP737");
                        } else if (strcmp(optarg, "koi2dos") == 0) {
                                cs_local = strdup("KOI8-R");
                                cs_dos = strdup("CP866");
                        } else if (strcmp(optarg, "koi8u2dos") == 0) {
                                cs_local = strdup("KOI8-U");
                                cs_dos = strdup("CP866");
                        } else {
                                err(EX_NOINPUT, "%s", optarg);
                        }
                        build_iovec(&iov, &iovlen, "cs_local", cs_local, (size_t)-1);
                        build_iovec(&iov, &iovlen, "cs_dos", cs_dos, (size_t)-1);
                        break;
                case '?':
                default:
                        usage();
                        break;
                }
        }

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

        if (set_mask && !set_dirmask) {
                dirmask = mask;
                set_dirmask = 1;
        }
        else if (set_dirmask && !set_mask) {
                mask = dirmask;
                set_mask = 1;
        }

        dev = argv[optind];
        dir = argv[optind + 1];

        if (cs_local != NULL) {
                if (set_charset(&iov, &iovlen, cs_local, cs_dos) == -1)
                        err(EX_OSERR, "msdosfs_iconv");
                build_iovec_argf(&iov, &iovlen, "kiconv", "");
        } else if (cs_dos != NULL) {
                build_iovec_argf(&iov, &iovlen, "cs_local", "ISO8859-1");
                if (set_charset(&iov, &iovlen, "ISO8859-1", cs_dos) == -1)
                        err(EX_OSERR, "msdosfs_iconv");
                build_iovec_argf(&iov, &iovlen, "kiconv", "");
        }

        /*
         * Resolve the mountpoint with realpath(3) and remove unnecessary
         * slashes from the devicename if there are any.
         */
        if (checkpath(dir, mntpath) != 0)
                err(EX_USAGE, "%s", mntpath);
        (void)rmslashes(dev, dev);

        if (!set_gid || !set_uid || !set_mask) {
                if (stat(mntpath, &sb) == -1)
                        err(EX_OSERR, "stat %s", mntpath);

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

        build_iovec(&iov, &iovlen, "fstype", fstype, (size_t)-1);
        build_iovec(&iov, &iovlen, "fspath", mntpath, (size_t)-1);
        build_iovec(&iov, &iovlen, "from", dev, (size_t)-1);
        build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
        build_iovec_argf(&iov, &iovlen, "uid", "%d", uid);
        build_iovec_argf(&iov, &iovlen, "gid", "%u", gid);
        build_iovec_argf(&iov, &iovlen, "mask", "%u", mask);
        build_iovec_argf(&iov, &iovlen, "dirmask", "%u", dirmask);

        if (nmount(iov, iovlen, 0) < 0) {
                if (errmsg[0])
                        err(1, "%s: %s", dev, errmsg);
                else
                        err(1, "%s", dev);
        }

        exit (0);
}

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

        if ((gr = getgrnam(s)) != NULL)
                gid = gr->gr_gid;
        else {
                for (gname = s; *s && isdigit(*s); ++s);
                if (!*s)
                        gid = atoi(gname);
                else
                        errx(EX_NOUSER, "unknown group id: %s", gname);
        }
        return (gid);
}

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

        if ((pw = getpwnam(s)) != NULL)
                uid = pw->pw_uid;
        else {
                for (uname = s; *s && isdigit(*s); ++s);
                if (!*s)
                        uid = atoi(uname);
                else
                        errx(EX_NOUSER, "unknown user id: %s", uname);
        }
        return (uid);
}

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

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

void
usage(void)
{
        fprintf(stderr, "%s\n%s\n%s\n",
        "usage: mount_msdosfs [-9ls] [-D DOS_codepage] [-g gid] [-L locale]",
        "                     [-M mask] [-m mask] [-o options] [-u uid]",
        "                     [-W table] special node");
        exit(EX_USAGE);
}

int
set_charset(struct iovec **iov, int *iovlen, const char *cs_local, const char *cs_dos)
{
        int error;

        if (modfind("msdosfs_iconv") < 0)
                if (kldload("msdosfs_iconv") < 0 || modfind("msdosfs_iconv") < 0) {
                        warnx("cannot find or load \"msdosfs_iconv\" kernel module");
                        return (-1);
                }

        build_iovec_argf(iov, iovlen, "cs_win", ENCODING_UNICODE);
        error = kiconv_add_xlat16_cspairs(ENCODING_UNICODE, cs_local);
        if (error && errno != EEXIST)
                return (-1);
        if (cs_dos != NULL) {
                error = kiconv_add_xlat16_cspairs(cs_dos, cs_local);
                if (error && errno != EEXIST)
                        return (-1);
        } else {
                build_iovec_argf(iov, iovlen, "cs_dos", cs_local);
                error = kiconv_add_xlat16_cspair(cs_local, cs_local,
                                KICONV_FROM_UPPER | KICONV_LOWER);
                if (error && errno != EEXIST)
                        return (-1);
        }

        return (0);
}