/* $NetBSD: main.c,v 1.6 2018/01/23 21:06:25 sevan Exp $ */

/*
 * Copyright (c) 2002, 2005
 *      Matthias Drochner.  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.
 *
 * 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.
 *
 */

/*
 * Generate an in-core disklabel for a CD, containing entries for
 * previous data tracks (supposed to be of previous sessions).
 * TODO:
 *  - support simulation of multisession CDs in a vnd(4) disk
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/cdio.h>
#include <sys/disklabel.h>
#include <sys/ioctl.h>
#include <sys/stat.h>

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

#include "dkcksum.h"
#include "mscdlabel.h"

static int getcdtoc(int);
static int getfaketoc(int);

const char *disk = "cd0";
int ntracks;
struct cd_toc_entry *tocbuf;

static int
getcdtoc(int fd)
{
        int res;
        struct ioc_toc_header th;
        struct ioc_read_toc_entry te;
        size_t tocbufsize;

        memset(&th, 0, sizeof(th));
        res = ioctl(fd, CDIOREADTOCHEADER, &th);
        if (res < 0) {
                warn("CDIOREADTOCHEADER");
                return (-1);
        }

        ntracks = th.ending_track - th.starting_track + 1;
        /* one more for leadout track, for tracklen calculation */
        tocbufsize = (ntracks + 1) * sizeof(struct cd_toc_entry);
        tocbuf = malloc(tocbufsize);
        if (!tocbuf)
                err(3, "alloc TOC buffer");
        memset(&te, 0, sizeof(te));
        te.address_format = CD_LBA_FORMAT;
        te.starting_track = th.starting_track; /* always 1 ??? */
        te.data_len = tocbufsize;
        te.data = tocbuf;
        res = ioctl(fd, CDIOREADTOCENTRIES, &te);
        if (res < 0)
                err(4, "CDIOREADTOCENTRIES");
        return (0);
}

static int
getfaketoc(int fd)
{
        int res;
        struct stat st;

        res = fstat(fd, &st);
        if (res < 0)
                err(4, "fstat");

        if (st.st_size % 2048) {
                warnx("size not multiple of 2048");
                return (-1);
        }

        tocbuf = malloc(2 * sizeof(struct cd_toc_entry));
        if (!tocbuf)
                err(3, "alloc TOC buffer");

        /*
         * fake up a data track spanning the whole file and a leadout track,
         * just as much as necessary for the scan below
         */
        tocbuf[0].addr.lba = 0;
        tocbuf[0].control = 4;
        tocbuf[1].addr.lba = st.st_size / 2048;
        tocbuf[1].control = 0;
        ntracks = 1;
        return (0);
}

int
main(int argc, char *argv[])
{
        int fd, res, i, j, rawpart;
        char fullname[MAXPATHLEN];
        struct cd_toc_entry *track;
        struct disklabel label;
        struct partition *p;
        int readonly = 0;

        if (argc > 1)
                disk = argv[1];

        fd = opendisk(disk, O_RDWR, fullname, MAXPATHLEN, 0);
        if (fd < 0) {
                warn("opendisk (read-write) %s", disk);
                fd = opendisk(disk, O_RDONLY, fullname, MAXPATHLEN, 0);
                if (fd < 0)
                        err(1, "opendisk %s", disk);
                readonly = 1;
        }

        /*
         * Get the TOC: first try to read a real one from a CD drive.
         * If this fails we might have something else keeping an ISO image
         * (eg. vnd(4) or plain file).
         */
        if (getcdtoc(fd) < 0 && getfaketoc(fd) < 0)
                exit(2);

        /*
         * Get label template. If this fails we might have a plain file.
         * Proceed to print out possible ISO label information, but
         * don't try to write a label back.
         */
        res = ioctl(fd, DIOCGDINFO, &label);
        if (res < 0) {
                warn("DIOCGDINFO");
                readonly = 1;
        }

        /*
         * We want entries for the sessions beginning with the most recent
         * one, in reversed time order.
         * We don't have session information here, but it is uncommon
         * to have more than one data track in one session, so we get
         * the same result.
         */
        if ((rawpart = getrawpartition()) == -1)
                err(1, "Cannot get raw partition");
        i = ntracks;
        j = 0;
        while (--i >= 0 && j < MAXPARTITIONS) {
                track = &tocbuf[i];
                printf("track (ctl=%d) at sector %d\n", track->control,
                       track->addr.lba);
                if ((track->control & 4) /* data track */
                    && check_primary_vd(fd, track->addr.lba,
                      (track+1)->addr.lba - track->addr.lba)) {
                        printf(" adding as '%c'\n", 'a' + j);
                        p = &label.d_partitions[j];
                        memset(p, 0, sizeof(struct partition));
                        p->p_size = label.d_partitions[rawpart].p_size;
                        p->p_fstype = FS_ISO9660;
                        p->p_cdsession = track->addr.lba;
                        if (++j == rawpart)
                                j++;
                }
        }
        if (!j) /* no ISO track, let the label alone */
                readonly = 1;

        if (!readonly) {
                /* write back label */
                if (label.d_npartitions < j)
                        label.d_npartitions = j;
                strncpy(label.d_packname, "mscdlabel's", 16);
                label.d_checksum = 0;
                label.d_checksum = dkcksum(&label);
                res = ioctl(fd, DIOCSDINFO, &label);
                if (res < 0)
                        err(6, "DIOCSDINFO");
        } else
                printf("disklabel not written\n");

        free(tocbuf);
        close(fd);
        return (0);
}