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