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: src/sys/ntfs/ntfs_compr.c,v 1.7 1999/12/03 20:37:38 semenu Exp $ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/proc.h> 34 #include <sys/namei.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 42 #include "ntfs.h" 43 #include "ntfs_compr.h" 44 45 #define GET_UINT16(addr) (*((u_int16_t *)(addr))) 46 47 int 48 ntfs_uncompblock(u_int8_t * buf, u_int8_t * cbuf) 49 { 50 u_int32_t ctag; 51 int len, dshift, lmask; 52 int blen, boff; 53 int i, j; 54 int pos, cpos; 55 56 len = GET_UINT16(cbuf) & 0xFFF; 57 dprintf(("ntfs_uncompblock: block length: %d + 3, 0x%x,0x%04x\n", 58 len, len, GET_UINT16(cbuf))); 59 60 if (!(GET_UINT16(cbuf) & 0x8000)) { 61 if ((len + 1) != NTFS_COMPBLOCK_SIZE) { 62 dprintf(("ntfs_uncompblock: len: %x instead of %d\n", 63 len, 0xfff)); 64 } 65 memcpy(buf, cbuf + 2, len + 1); 66 bzero(buf + len + 1, NTFS_COMPBLOCK_SIZE - 1 - len); 67 return len + 3; 68 } 69 cpos = 2; 70 pos = 0; 71 while ((cpos < len + 3) && (pos < NTFS_COMPBLOCK_SIZE)) { 72 ctag = cbuf[cpos++]; 73 for (i = 0; (i < 8) && (pos < NTFS_COMPBLOCK_SIZE); i++) { 74 if (ctag & 1) { 75 for (j = pos - 1, lmask = 0xFFF, dshift = 12; 76 j >= 0x10; j >>= 1) { 77 dshift--; 78 lmask >>= 1; 79 } 80 boff = -1 - (GET_UINT16(cbuf + cpos) >> dshift); 81 blen = 3 + (GET_UINT16(cbuf + cpos) & lmask); 82 for (j = 0; (j < blen) && (pos < NTFS_COMPBLOCK_SIZE); j++) { 83 buf[pos] = buf[pos + boff]; 84 pos++; 85 } 86 cpos += 2; 87 } else { 88 buf[pos++] = cbuf[cpos++]; 89 } 90 ctag >>= 1; 91 } 92 } 93 return len + 3; 94 } 95 96 int 97 ntfs_uncompunit( 98 struct ntfsmount * ntmp, 99 u_int8_t * uup, 100 u_int8_t * cup) 101 { 102 int i; 103 int off = 0; 104 int new; 105 106 for (i = 0; i * NTFS_COMPBLOCK_SIZE < ntfs_cntob(NTFS_COMPUNIT_CL); i++) { 107 new = ntfs_uncompblock(uup + i * NTFS_COMPBLOCK_SIZE, cup + off); 108 if (new == 0) 109 return (EINVAL); 110 off += new; 111 } 112 return (0); 113 } 114