/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1992, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley
 * by Pace Willisson (pace@blitz.com).  The Rock Ridge Extension
 * Support code is derived from software contributed to Berkeley
 * by Atsushi Murai (amurai@spec.co.jp).
 *
 * 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/cdio.h>
#include <sys/file.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/module.h>
#include <sys/iconv.h>
#include <sys/linker.h>

#include <arpa/inet.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <grp.h>
#include <mntopts.h>
#include <pwd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

static struct mntopt mopts[] = {
        MOPT_STDOPTS,
        MOPT_UPDATE,
        MOPT_END
};

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

int
main(int argc, char **argv)
{
        struct iovec *iov;
        int iovlen;
        int ch, mntflags;
        char *dev, *dir, *p, *val, mntpath[MAXPATHLEN];
        int verbose;
        int ssector;            /* starting sector, 0 for 1st session */
        char fstype[] = "cd9660";

        iov = NULL;
        iovlen = 0;
        mntflags = verbose = 0;
        ssector = -1;

        while ((ch = getopt(argc, argv, "begG:jm:M:o:rs:U:vC:")) != -1)
                switch (ch) {
                case 'b':
                        build_iovec(&iov, &iovlen, "brokenjoliet", NULL, (size_t)-1);
                        break;
                case 'e':
                        build_iovec(&iov, &iovlen, "extatt", NULL, (size_t)-1);
                        break;
                case 'g':
                        build_iovec(&iov, &iovlen, "gens", NULL, (size_t)-1);
                        break;
                case 'G':
                        build_iovec_argf(&iov, &iovlen, "gid", "%d", a_gid(optarg));
                        break;
                case 'm':
                        build_iovec_argf(&iov, &iovlen, "mask", "%u", a_mask(optarg));
                        break;
                case 'M':
                        build_iovec_argf(&iov, &iovlen, "dirmask", "%u", a_mask(optarg));
                        break;
                case 'j':
                        build_iovec(&iov, &iovlen, "nojoliet", NULL, (size_t)-1);
                        break;
                case 'o':
                        getmntopts(optarg, mopts, &mntflags, NULL);
                        p = strchr(optarg, '=');
                        val = NULL;
                        if (p != NULL) {
                                *p = '\0';
                                val = p + 1;
                        }
                        build_iovec(&iov, &iovlen, optarg, val, (size_t)-1);
                        break;
                case 'r':
                        build_iovec(&iov, &iovlen, "norrip", NULL, (size_t)-1);
                        break;
                case 's':
                        ssector = atoi(optarg);
                        break;
                case 'U':
                        build_iovec_argf(&iov, &iovlen, "uid", "%d", a_uid(optarg));
                        break;
                case 'v':
                        verbose++;
                        break;
                case 'C':
                        if (set_charset(&iov, &iovlen, optarg) == -1)
                                err(EX_OSERR, "cd9660_iconv");
                        build_iovec(&iov, &iovlen, "kiconv", NULL, (size_t)-1);
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (argc != 2)
                usage();

        dev = argv[0];
        dir = argv[1];

        /*
         * Resolve the mountpoint with realpath(3) and remove unnecessary
         * slashes from the devicename if there are any.
         */
        if (checkpath(dir, mntpath) != 0)
                err(1, "%s", mntpath);
        (void)rmslashes(dev, dev);

        if (ssector == -1) {
                /*
                 * The start of the session has not been specified on
                 * the command line.  If we can successfully read the
                 * TOC of a CD-ROM, use the last data track we find.
                 * Otherwise, just use 0, in order to mount the very
                 * first session.  This is compatible with the
                 * historic behaviour of mount_cd9660(8).  If the user
                 * has specified -s <ssector> above, we don't get here
                 * and leave the user's will.
                 */
                if ((ssector = get_ssector(dev)) == -1) {
                        if (verbose)
                                printf("could not determine starting sector, "
                                       "using very first session\n");
                        ssector = 0;
                } else if (verbose)
                        printf("using starting sector %d\n", ssector);
        }
        mntflags |= MNT_RDONLY;
        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_argf(&iov, &iovlen, "ssector", "%d", ssector);

        if (nmount(iov, iovlen, mntflags) < 0)
                err(1, "%s", dev);
        exit(0);
}

void
usage(void)
{
        (void)fprintf(stderr,
"usage: mount_cd9660 [-begjrv] [-C charset] [-G gid] [-m mask] [-M mask]\n"
"                    [-o options] [-U uid] [-s startsector] special node\n");
        exit(EX_USAGE);
}

static int
get_ssector(const char *dev)
{
        struct ioc_toc_header h;
        struct ioc_read_toc_entry t;
        struct cd_toc_entry toc_buffer[100];
        int fd, ntocentries, i;

        if ((fd = open(dev, O_RDONLY)) == -1)
                return -1;
        if (ioctl(fd, CDIOREADTOCHEADER, &h) == -1) {
                close(fd);
                return -1;
        }

        ntocentries = h.ending_track - h.starting_track + 1;
        if (ntocentries > 100) {
                /* unreasonable, only 100 allowed */
                close(fd);
                return -1;
        }
        t.address_format = CD_LBA_FORMAT;
        t.starting_track = 0;
        t.data_len = ntocentries * sizeof(struct cd_toc_entry);
        t.data = toc_buffer;

        if (ioctl(fd, CDIOREADTOCENTRYS, (char *) &t) == -1) {
                close(fd);
                return -1;
        }
        close(fd);
        
        for (i = ntocentries - 1; i >= 0; i--)
                if ((toc_buffer[i].control & 4) != 0)
                        /* found a data track */
                        break;
        if (i < 0)
                return -1;

        return ntohl(toc_buffer[i].addr.lba);
}

static int
set_charset(struct iovec **iov, int *iovlen, const char *localcs)
{
        int error;
        char *cs_disk;  /* disk charset for Joliet cs conversion */
        char *cs_local; /* local charset for Joliet cs conversion */

        cs_disk = NULL;
        cs_local = NULL;

        if (modfind("cd9660_iconv") < 0)
                if (kldload("cd9660_iconv") < 0 || modfind("cd9660_iconv") < 0) {
                        warnx( "cannot find or load \"cd9660_iconv\" kernel module");
                        return (-1);
                }

        if ((cs_disk = malloc(ICONV_CSNMAXLEN)) == NULL)
                return (-1);
        if ((cs_local = malloc(ICONV_CSNMAXLEN)) == NULL) {
                free(cs_disk);
                return (-1);
        }
        strncpy(cs_disk, ENCODING_UNICODE, ICONV_CSNMAXLEN);
        strncpy(cs_local, kiconv_quirkcs(localcs, KICONV_VENDOR_MICSFT),
            ICONV_CSNMAXLEN);
        error = kiconv_add_xlat16_cspairs(cs_disk, cs_local);
        if (error)
                return (-1);
        
        build_iovec(iov, iovlen, "cs_disk", cs_disk, (size_t)-1);
        build_iovec(iov, iovlen, "cs_local", cs_local, (size_t)-1);

        return (0);
}

static gid_t
a_gid(const char *s)
{
        struct group *gr;
        const 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);
}

static uid_t
a_uid(const char *s)
{
        struct passwd *pw;
        const 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);
}

static mode_t
a_mask(const 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);
}