ntfs_compr.c revision 50477
1/* $NetBSD: ntfs_compr.c,v 1.2 1999/05/06 15:43:18 christos 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: head/sys/fs/ntfs/ntfs_compr.c 50477 1999-08-28 01:08:13Z peter $ 29 */ 30 31#include <sys/param.h> 32#include <sys/systm.h> 33#include <sys/namei.h> 34#include <sys/proc.h> 35#include <sys/kernel.h> 36#include <sys/vnode.h> 37#include <sys/mount.h> 38#include <sys/buf.h> 39#include <sys/file.h> 40#include <sys/malloc.h> 41#ifdef __FreeBSD__ 42#include <machine/clock.h> 43#endif 44 45#include <ntfs/ntfs.h> 46#include <ntfs/ntfs_compr.h> 47 48#define GET_UINT16(addr) (*((u_int16_t *)(addr))) 49 50int 51ntfs_uncompblock( 52 u_int8_t * buf, 53 u_int8_t * cbuf) 54{ 55 u_int32_t ctag; 56 int len, dshift, lmask; 57 int blen, boff; 58 int i, j; 59 int pos, cpos; 60 61 len = GET_UINT16(cbuf) & 0xFFF; 62 dprintf(("ntfs_uncompblock: block length: %d + 3, 0x%x,0x%04x\n", 63 len, len, GET_UINT16(cbuf))); 64 65 if (!(GET_UINT16(cbuf) & 0x8000)) { 66 if ((len + 1) != NTFS_COMPBLOCK_SIZE) { 67 dprintf(("ntfs_uncompblock: len: %x instead of %d\n", 68 len, 0xfff)); 69 } 70 memcpy(buf, cbuf + 2, len + 1); 71 bzero(buf + len + 1, NTFS_COMPBLOCK_SIZE - 1 - len); 72 return len + 3; 73 } 74 cpos = 2; 75 pos = 0; 76 while ((cpos < len + 3) && (pos < NTFS_COMPBLOCK_SIZE)) { 77 ctag = cbuf[cpos++]; 78 for (i = 0; (i < 8) && (pos < NTFS_COMPBLOCK_SIZE); i++) { 79 if (ctag & 1) { 80 for (j = pos - 1, lmask = 0xFFF, dshift = 12; 81 j >= 0x10; j >>= 1) { 82 dshift--; 83 lmask >>= 1; 84 } 85 boff = -1 - (GET_UINT16(cbuf + cpos) >> dshift); 86 blen = 3 + (GET_UINT16(cbuf + cpos) & lmask); 87 for (j = 0; (j < blen) && (pos < NTFS_COMPBLOCK_SIZE); j++) { 88 buf[pos] = buf[pos + boff]; 89 pos++; 90 } 91 cpos += 2; 92 } else { 93 buf[pos++] = cbuf[cpos++]; 94 } 95 ctag >>= 1; 96 } 97 } 98 return len + 3; 99} 100 101int 102ntfs_uncompunit( 103 struct ntfsmount * ntmp, 104 u_int8_t * uup, 105 u_int8_t * cup) 106{ 107 int i; 108 int off = 0; 109 int new; 110 111 for (i = 0; i * NTFS_COMPBLOCK_SIZE < ntfs_cntob(NTFS_COMPUNIT_CL); i++) { 112 new = ntfs_uncompblock(uup + i * NTFS_COMPBLOCK_SIZE, cup + off); 113 if (new == 0) 114 return (EINVAL); 115 off += new; 116 } 117 return (0); 118} 119