/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1982, 1986, 1989, 1994, 1995
 *      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/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/stat.h>
#include <sys/mutex.h>

#include <fs/cd9660/iso.h>
#include <fs/cd9660/cd9660_node.h>
#include <fs/cd9660/cd9660_mount.h>

static unsigned cd9660_chars2ui(unsigned char *begin, int len);

/*
 * Last reference to an inode, write the inode out and if necessary,
 * truncate and deallocate the file.
 */
int
cd9660_inactive(struct vop_inactive_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct iso_node *ip = VTOI(vp);
        int error = 0;

        /*
         * If we are done with the inode, reclaim it
         * so that it can be reused immediately.
         */
        if (ip->inode.iso_mode == 0)
                vrecycle(vp);
        return error;
}

/*
 * Reclaim an inode so that it can be used for other purposes.
 */
int
cd9660_reclaim(struct vop_reclaim_args *ap)
{
        struct vnode *vp = ap->a_vp;

        /*
         * Remove the inode from its hash chain.
         */
        vfs_hash_remove(vp);

        /*
         * Purge old data structures associated with the inode.
         */
        free(vp->v_data, M_ISOFSNODE);
        vp->v_data = NULL;
        return (0);
}

/*
 * File attributes
 */
void
cd9660_defattr(struct iso_directory_record *isodir, struct iso_node *inop,
    struct buf *bp, enum ISO_FTYPE ftype)
{
        struct buf *bp2 = NULL;
        struct iso_mnt *imp;
        struct iso_extended_attributes *ap = NULL;
        int off;

        /* high sierra does not have timezone data, flag is one byte ahead */
        if (isonum_711(ftype == ISO_FTYPE_HIGH_SIERRA?
                       &isodir->date[6]: isodir->flags)&2) {
                inop->inode.iso_mode = S_IFDIR;
                /*
                 * If we return 2, fts() will assume there are no subdirectories
                 * (just links for the path and .), so instead we return 1.
                 */
                inop->inode.iso_links = 1;
        } else {
                inop->inode.iso_mode = S_IFREG;
                inop->inode.iso_links = 1;
        }
        if (!bp
            && ((imp = inop->i_mnt)->im_flags & ISOFSMNT_EXTATT)
            && (off = isonum_711(isodir->ext_attr_length))) {
                cd9660_blkatoff(ITOV(inop), (off_t)-(off << imp->im_bshift), NULL,
                             &bp2);
                bp = bp2;
        }
        if (bp) {
                ap = (struct iso_extended_attributes *)bp->b_data;

                if (isonum_711(ap->version) == 1) {
                        if (!(ap->perm[0]&0x40))
                                inop->inode.iso_mode |= S_IXOTH;
                        if (!(ap->perm[0]&0x10))
                                inop->inode.iso_mode |= S_IROTH;
                        if (!(ap->perm[0]&4))
                                inop->inode.iso_mode |= S_IXGRP;
                        if (!(ap->perm[0]&1))
                                inop->inode.iso_mode |= S_IRGRP;
                        if (!(ap->perm[1]&0x40))
                                inop->inode.iso_mode |= S_IXUSR;
                        if (!(ap->perm[1]&0x10))
                                inop->inode.iso_mode |= S_IRUSR;
                        inop->inode.iso_uid = isonum_723(ap->owner); /* what about 0? */
                        inop->inode.iso_gid = isonum_723(ap->group); /* what about 0? */
                } else
                        ap = NULL;
        }
        if (!ap) {
                inop->inode.iso_mode |= S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
                inop->inode.iso_uid = (uid_t)0;
                inop->inode.iso_gid = (gid_t)0;
        }
        if (bp2)
                brelse(bp2);
}

/*
 * Time stamps
 */
void
cd9660_deftstamp(struct iso_directory_record *isodir, struct iso_node *inop,
    struct buf *bp, enum ISO_FTYPE ftype)
{
        struct buf *bp2 = NULL;
        struct iso_mnt *imp;
        struct iso_extended_attributes *ap = NULL;
        int off;

        if (!bp
            && ((imp = inop->i_mnt)->im_flags & ISOFSMNT_EXTATT)
            && (off = isonum_711(isodir->ext_attr_length))) {
                cd9660_blkatoff(ITOV(inop), (off_t)-(off << imp->im_bshift), NULL,
                             &bp2);
                bp = bp2;
        }
        if (bp) {
                ap = (struct iso_extended_attributes *)bp->b_data;

                if (ftype != ISO_FTYPE_HIGH_SIERRA
                    && isonum_711(ap->version) == 1) {
                        if (!cd9660_tstamp_conv17(ap->ftime,&inop->inode.iso_atime))
                                cd9660_tstamp_conv17(ap->ctime,&inop->inode.iso_atime);
                        if (!cd9660_tstamp_conv17(ap->ctime,&inop->inode.iso_ctime))
                                inop->inode.iso_ctime = inop->inode.iso_atime;
                        if (!cd9660_tstamp_conv17(ap->mtime,&inop->inode.iso_mtime))
                                inop->inode.iso_mtime = inop->inode.iso_ctime;
                } else
                        ap = NULL;
        }
        if (!ap) {
                cd9660_tstamp_conv7(isodir->date,&inop->inode.iso_ctime,ftype);
                inop->inode.iso_atime = inop->inode.iso_ctime;
                inop->inode.iso_mtime = inop->inode.iso_ctime;
        }
        if (bp2)
                brelse(bp2);
}

int
cd9660_tstamp_conv7(u_char *pi, struct timespec *pu, enum ISO_FTYPE ftype)
{
        int crtime, days;
        int y, m, d, hour, minute, second, tz;

        y = pi[0] + 1900;
        m = pi[1];
        d = pi[2];
        hour = pi[3];
        minute = pi[4];
        second = pi[5];
        if(ftype != ISO_FTYPE_HIGH_SIERRA)
                tz = ((signed char *)pi)[6]; /* Timezone value is signed. */
        else
                /* original high sierra misses timezone data */
                tz = 0;

        if (y < 1970) {
                pu->tv_sec  = 0;
                pu->tv_nsec = 0;
                return 0;
        } else {
#ifdef  ORIGINAL
                /* computes day number relative to Sept. 19th,1989 */
                /* don't even *THINK* about changing formula. It works! */
                days = 367*(y-1980)-7*(y+(m+9)/12)/4-3*((y+(m-9)/7)/100+1)/4+275*m/9+d-100;
#else
                /*
                 * Changed :-) to make it relative to Jan. 1st, 1970
                 * and to disambiguate negative division
                 */
                days = 367*(y-1960)-7*(y+(m+9)/12)/4-3*((y+(m+9)/12-1)/100+1)/4+275*m/9+d-239;
#endif
                crtime = ((((days * 24) + hour) * 60 + minute) * 60) + second;

                /* timezone offset is unreliable on some disks */
                if (-48 <= tz && tz <= 52)
                        crtime -= tz * 15 * 60;
        }
        pu->tv_sec  = crtime;
        pu->tv_nsec = 0;
        return 1;
}

static u_int
cd9660_chars2ui(u_char *begin, int len)
{
        u_int rc;

        for (rc = 0; --len >= 0;) {
                rc *= 10;
                rc += *begin++ - '0';
        }
        return rc;
}

int
cd9660_tstamp_conv17(u_char *pi, struct timespec *pu)
{
        u_char buf[7];

        /* year:"0001"-"9999" -> -1900  */
        buf[0] = cd9660_chars2ui(pi,4) - 1900;

        /* month: " 1"-"12"   -> 1 - 12 */
        buf[1] = cd9660_chars2ui(pi + 4,2);

        /* day:   " 1"-"31"   -> 1 - 31 */
        buf[2] = cd9660_chars2ui(pi + 6,2);

        /* hour:  " 0"-"23"   -> 0 - 23 */
        buf[3] = cd9660_chars2ui(pi + 8,2);

        /* minute:" 0"-"59"   -> 0 - 59 */
        buf[4] = cd9660_chars2ui(pi + 10,2);

        /* second:" 0"-"59"   -> 0 - 59 */
        buf[5] = cd9660_chars2ui(pi + 12,2);

        /* difference of GMT */
        buf[6] = pi[16];

        return cd9660_tstamp_conv7(buf, pu, ISO_FTYPE_DEFAULT);
}

ino_t
isodirino(struct iso_directory_record *isodir, struct iso_mnt *imp)
{
        ino_t ino;

        /*
         * Note there is an inverse calculation in
         * cd9660_vfsops.c:cd9660_vget_internal():
         *   ip->iso_start = ino >> imp->im_bshift;
         * and also a calculation of the isodir pointer
         * from an inode in cd9660_vnops.c:cd9660_readlink()
         */
        ino = ((ino_t)isonum_733(isodir->extent) +
                isonum_711(isodir->ext_attr_length)) << imp->im_bshift;
        return ino;
}