ntfs_compr.c revision 225736
1/* $NetBSD: ntfs_compr.c,v 1.3 1999/07/26 14:02:31 jdolecek Exp $ */ 2 3/*- 4 * Copyright (c) 1998, 1999 Semen Ustimenko 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: stable/9/sys/fs/ntfs/ntfs_compr.c 86927 2001-11-26 23:45:12Z jhb $ 29 */ 30 31#include <sys/param.h> 32#include <sys/systm.h> 33#include <sys/namei.h> 34#include <sys/vnode.h> 35#include <sys/mount.h> 36#include <sys/file.h> 37 38#include <fs/ntfs/ntfs.h> 39#include <fs/ntfs/ntfs_compr.h> 40 41#define GET_UINT16(addr) (*((u_int16_t *)(addr))) 42 43int 44ntfs_uncompblock( 45 u_int8_t * buf, 46 u_int8_t * cbuf) 47{ 48 u_int32_t ctag; 49 int len, dshift, lmask; 50 int blen, boff; 51 int i, j; 52 int pos, cpos; 53 54 len = GET_UINT16(cbuf) & 0xFFF; 55 dprintf(("ntfs_uncompblock: block length: %d + 3, 0x%x,0x%04x\n", 56 len, len, GET_UINT16(cbuf))); 57 58 if (!(GET_UINT16(cbuf) & 0x8000)) { 59 if ((len + 1) != NTFS_COMPBLOCK_SIZE) { 60 dprintf(("ntfs_uncompblock: len: %x instead of %d\n", 61 len, 0xfff)); 62 } 63 memcpy(buf, cbuf + 2, len + 1); 64 bzero(buf + len + 1, NTFS_COMPBLOCK_SIZE - 1 - len); 65 return len + 3; 66 } 67 cpos = 2; 68 pos = 0; 69 while ((cpos < len + 3) && (pos < NTFS_COMPBLOCK_SIZE)) { 70 ctag = cbuf[cpos++]; 71 for (i = 0; (i < 8) && (pos < NTFS_COMPBLOCK_SIZE); i++) { 72 if (ctag & 1) { 73 for (j = pos - 1, lmask = 0xFFF, dshift = 12; 74 j >= 0x10; j >>= 1) { 75 dshift--; 76 lmask >>= 1; 77 } 78 boff = -1 - (GET_UINT16(cbuf + cpos) >> dshift); 79 blen = 3 + (GET_UINT16(cbuf + cpos) & lmask); 80 for (j = 0; (j < blen) && (pos < NTFS_COMPBLOCK_SIZE); j++) { 81 buf[pos] = buf[pos + boff]; 82 pos++; 83 } 84 cpos += 2; 85 } else { 86 buf[pos++] = cbuf[cpos++]; 87 } 88 ctag >>= 1; 89 } 90 } 91 return len + 3; 92} 93 94int 95ntfs_uncompunit( 96 struct ntfsmount * ntmp, 97 u_int8_t * uup, 98 u_int8_t * cup) 99{ 100 int i; 101 int off = 0; 102 int new; 103 104 for (i = 0; i * NTFS_COMPBLOCK_SIZE < ntfs_cntob(NTFS_COMPUNIT_CL); i++) { 105 new = ntfs_uncompblock(uup + i * NTFS_COMPBLOCK_SIZE, cup + off); 106 if (new == 0) 107 return (EINVAL); 108 off += new; 109 } 110 return (0); 111} 112