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freebsd/sys/fs/ntfs/ntfs_compr.c
2000-04-29 15:36:14 +00:00

117 lines
3.3 KiB
C

/* $NetBSD: ntfs_compr.c,v 1.3 1999/07/26 14:02:31 jdolecek Exp $ */
/*-
* Copyright (c) 1998, 1999 Semen Ustimenko
* 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 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/file.h>
#if defined(__NetBSD__)
#include <miscfs/specfs/specdev.h>
#endif
#include <ntfs/ntfs.h>
#include <ntfs/ntfs_compr.h>
#define GET_UINT16(addr) (*((u_int16_t *)(addr)))
int
ntfs_uncompblock(
u_int8_t * buf,
u_int8_t * cbuf)
{
u_int32_t ctag;
int len, dshift, lmask;
int blen, boff;
int i, j;
int pos, cpos;
len = GET_UINT16(cbuf) & 0xFFF;
dprintf(("ntfs_uncompblock: block length: %d + 3, 0x%x,0x%04x\n",
len, len, GET_UINT16(cbuf)));
if (!(GET_UINT16(cbuf) & 0x8000)) {
if ((len + 1) != NTFS_COMPBLOCK_SIZE) {
dprintf(("ntfs_uncompblock: len: %x instead of %d\n",
len, 0xfff));
}
memcpy(buf, cbuf + 2, len + 1);
bzero(buf + len + 1, NTFS_COMPBLOCK_SIZE - 1 - len);
return len + 3;
}
cpos = 2;
pos = 0;
while ((cpos < len + 3) && (pos < NTFS_COMPBLOCK_SIZE)) {
ctag = cbuf[cpos++];
for (i = 0; (i < 8) && (pos < NTFS_COMPBLOCK_SIZE); i++) {
if (ctag & 1) {
for (j = pos - 1, lmask = 0xFFF, dshift = 12;
j >= 0x10; j >>= 1) {
dshift--;
lmask >>= 1;
}
boff = -1 - (GET_UINT16(cbuf + cpos) >> dshift);
blen = 3 + (GET_UINT16(cbuf + cpos) & lmask);
for (j = 0; (j < blen) && (pos < NTFS_COMPBLOCK_SIZE); j++) {
buf[pos] = buf[pos + boff];
pos++;
}
cpos += 2;
} else {
buf[pos++] = cbuf[cpos++];
}
ctag >>= 1;
}
}
return len + 3;
}
int
ntfs_uncompunit(
struct ntfsmount * ntmp,
u_int8_t * uup,
u_int8_t * cup)
{
int i;
int off = 0;
int new;
for (i = 0; i * NTFS_COMPBLOCK_SIZE < ntfs_cntob(NTFS_COMPUNIT_CL); i++) {
new = ntfs_uncompblock(uup + i * NTFS_COMPBLOCK_SIZE, cup + off);
if (new == 0)
return (EINVAL);
off += new;
}
return (0);
}