/*      $OpenBSD: cd9660_node.c,v 1.38 2021/10/19 06:11:45 semarie Exp $        */
/*      $NetBSD: cd9660_node.c,v 1.17 1997/05/05 07:13:57 mycroft Exp $ */

/*-
 * Copyright (c) 1982, 1986, 1989, 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.
 *
 *      @(#)cd9660_node.c       8.5 (Berkeley) 12/5/94
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/lock.h>
#include <sys/namei.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/stat.h>

#include <crypto/siphash.h>

#include <isofs/cd9660/iso.h>
#include <isofs/cd9660/cd9660_extern.h>
#include <isofs/cd9660/cd9660_node.h>

/*
 * Structures associated with iso_node caching.
 */
u_int cd9660_isohash(dev_t, cdino_t);

struct iso_node **isohashtbl;
u_long isohash;
SIPHASH_KEY isohashkey;
#define INOHASH(device, inum) cd9660_isohash((device), (inum))

extern int prtactive;   /* 1 => print out reclaim of active vnodes */

static u_int cd9660_chars2ui(u_char *, int);

/*
 * Initialize hash links for inodes and dnodes.
 */
int
cd9660_init(struct vfsconf *vfsp)
{

        isohashtbl = hashinit(initialvnodes, M_ISOFSMNT, M_WAITOK, &isohash);
        arc4random_buf(&isohashkey, sizeof(isohashkey));
        return (0);
}

u_int
cd9660_isohash(dev_t device, cdino_t inum)
{
        SIPHASH_CTX ctx;

        SipHash24_Init(&ctx, &isohashkey);
        SipHash24_Update(&ctx, &device, sizeof(device));
        SipHash24_Update(&ctx, &inum, sizeof(inum));
        return (SipHash24_End(&ctx) & isohash);
}

/*
 * Use the device/inum pair to find the incore inode, and return a pointer
 * to it. If it is in core, but locked, wait for it.
 */
struct vnode *
cd9660_ihashget(dev_t dev, cdino_t inum)
{
        struct iso_node *ip;
        struct vnode *vp;

loop:
        /* XXX locking lock hash list? */
       for (ip = isohashtbl[INOHASH(dev, inum)]; ip; ip = ip->i_next) {
               if (inum == ip->i_number && dev == ip->i_dev) {
                       vp = ITOV(ip);
                        /* XXX locking unlock hash list? */
                       if (vget(vp, LK_EXCLUSIVE))
                               goto loop;
                       return (vp);
               }
       }
        /* XXX locking unlock hash list? */
       return (NULL);
}

/*
 * Insert the inode into the hash table, and return it locked.
 */
int
cd9660_ihashins(struct iso_node *ip)
{
        struct iso_node **ipp, *iq;

        /* XXX locking lock hash list? */
        ipp = &isohashtbl[INOHASH(ip->i_dev, ip->i_number)];

        for (iq = *ipp; iq; iq = iq->i_next) {
                if (iq->i_dev == ip->i_dev &&
                    iq->i_number == ip->i_number)
                        return (EEXIST);
        }
                              
        if ((iq = *ipp) != NULL)
                iq->i_prev = &ip->i_next;
        ip->i_next = iq;
        ip->i_prev = ipp;
        *ipp = ip;
        /* XXX locking unlock hash list? */

        VOP_LOCK(ITOV(ip), LK_EXCLUSIVE);

        return (0);
}

/*
 * Remove the inode from the hash table.
 */
void
cd9660_ihashrem(struct iso_node *ip)
{
        struct iso_node *iq;

        if (ip->i_prev == NULL)
                return;
        
        /* XXX locking lock hash list? */
        if ((iq = ip->i_next) != NULL)
                iq->i_prev = ip->i_prev;
        *ip->i_prev = iq;
#ifdef DIAGNOSTIC
        ip->i_next = NULL;
        ip->i_prev = NULL;
#endif
        /* XXX locking unlock hash list? */
}

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

#ifdef DIAGNOSTIC
        if (prtactive && vp->v_usecount != 0)
                vprint("cd9660_inactive: pushing active", vp);
#endif
        
        ip->i_flag = 0;
        VOP_UNLOCK(vp);
        /*
         * If we are done with the inode, reclaim it
         * so that it can be reused immediately.
         */
        if (ip->inode.iso_mode == 0)
                vrecycle(vp, ap->a_p);

        return (error);
}

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

#ifdef DIAGNOSTIC
        if (prtactive && vp->v_usecount != 0)
                vprint("cd9660_reclaim: pushing active", vp);
#endif

        /*
         * Remove the inode from its hash chain.
         */
        cd9660_ihashrem(ip);
        /*
         * Purge old data structures associated with the inode.
         */
        cache_purge(vp);
        if (ip->i_devvp) {
                vrele(ip->i_devvp);
                ip->i_devvp = 0;
        }
        free(vp->v_data, M_ISOFSNODE, 0);
        vp->v_data = NULL;
        return (0);
}

/*
 * File attributes
 */
void
cd9660_defattr(struct iso_directory_record *isodir, struct iso_node *inop,
    struct buf *bp)
{
        struct buf *bp2 = NULL;
        struct iso_mnt *imp;
        struct iso_extended_attributes *ap = NULL;
        int off;
        
        if (isonum_711(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_bufatoff(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[1]&0x10))
                                inop->inode.iso_mode |= S_IRUSR;
                        if (!(ap->perm[1]&0x40))
                                inop->inode.iso_mode |= S_IXUSR;
                        if (!(ap->perm[0]&0x01))
                                inop->inode.iso_mode |= S_IRGRP;
                        if (!(ap->perm[0]&0x04))
                                inop->inode.iso_mode |= S_IXGRP;
                        if (!(ap->perm[0]&0x10))
                                inop->inode.iso_mode |= S_IROTH;
                        if (!(ap->perm[0]&0x40))
                                inop->inode.iso_mode |= S_IXOTH;
                        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)
{
        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_bufatoff(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 (!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);
                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)
{
        int crtime, days;
        int y, m, d, hour, minute, second;
        signed char tz;
        
        y = pi[0] + 1900;
        m = pi[1];
        d = pi[2];
        hour = pi[3];
        minute = pi[4];
        second = pi[5];
        tz = (signed char) pi[6];
        
        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));
}

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

        ino = (isonum_733(isodir->extent) +
            isonum_711(isodir->ext_attr_length)) << imp->im_bshift;
        return (ino);
}