1 /* $NetBSD: ntfs_compr.c,v 1.1 2002/12/23 17:38:31 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 * Id: ntfs_compr.c,v 1.4 1999/05/12 09:42:54 semenu Exp 29 */ 30 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: ntfs_compr.c,v 1.1 2002/12/23 17:38:31 jdolecek Exp $"); 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/namei.h> 37 #include <sys/proc.h> 38 #include <sys/kernel.h> 39 #include <sys/vnode.h> 40 #include <sys/mount.h> 41 #include <sys/buf.h> 42 #include <sys/file.h> 43 #include <sys/malloc.h> 44 #ifdef __FreeBSD__ 45 #include <machine/clock.h> 46 #endif 47 48 #include <miscfs/specfs/specdev.h> 49 50 #include <fs/ntfs/ntfs.h> 51 #include <fs/ntfs/ntfs_compr.h> 52 53 #define GET_UINT16(addr) (*((u_int16_t *)(addr))) 54 55 int 56 ntfs_uncompblock( 57 u_int8_t * buf, 58 u_int8_t * cbuf) 59 { 60 u_int32_t ctag; 61 int len, dshift, lmask; 62 int blen, boff; 63 int i, j; 64 int pos, cpos; 65 66 len = GET_UINT16(cbuf) & 0xFFF; 67 dprintf(("ntfs_uncompblock: block length: %d + 3, 0x%x,0x%04x\n", 68 len, len, GET_UINT16(cbuf))); 69 70 if (!(GET_UINT16(cbuf) & 0x8000)) { 71 if ((len + 1) != NTFS_COMPBLOCK_SIZE) { 72 dprintf(("ntfs_uncompblock: len: %x instead of %d\n", 73 len, 0xfff)); 74 } 75 memcpy(buf, cbuf + 2, len + 1); 76 bzero(buf + len + 1, NTFS_COMPBLOCK_SIZE - 1 - len); 77 return len + 3; 78 } 79 cpos = 2; 80 pos = 0; 81 while ((cpos < len + 3) && (pos < NTFS_COMPBLOCK_SIZE)) { 82 ctag = cbuf[cpos++]; 83 for (i = 0; (i < 8) && (pos < NTFS_COMPBLOCK_SIZE); i++) { 84 if (ctag & 1) { 85 for (j = pos - 1, lmask = 0xFFF, dshift = 12; 86 j >= 0x10; j >>= 1) { 87 dshift--; 88 lmask >>= 1; 89 } 90 boff = -1 - (GET_UINT16(cbuf + cpos) >> dshift); 91 blen = 3 + (GET_UINT16(cbuf + cpos) & lmask); 92 for (j = 0; (j < blen) && (pos < NTFS_COMPBLOCK_SIZE); j++) { 93 buf[pos] = buf[pos + boff]; 94 pos++; 95 } 96 cpos += 2; 97 } else { 98 buf[pos++] = cbuf[cpos++]; 99 } 100 ctag >>= 1; 101 } 102 } 103 return len + 3; 104 } 105 106 int 107 ntfs_uncompunit( 108 struct ntfsmount * ntmp, 109 u_int8_t * uup, 110 u_int8_t * cup) 111 { 112 int i; 113 int off = 0; 114 int new; 115 116 for (i = 0; i * NTFS_COMPBLOCK_SIZE < ntfs_cntob(NTFS_COMPUNIT_CL); i++) { 117 new = ntfs_uncompblock(uup + i * NTFS_COMPBLOCK_SIZE, cup + off); 118 if (new == 0) 119 return (EINVAL); 120 off += new; 121 } 122 return (0); 123 } 124