| 1 | /* $NetBSD: ntfs_compr.c,v 1.6 2015/02/20 17:08:13 maxv 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 1.6 2015/02/20 17:08:13 maxv Exp $" ); |
| 33 | |
| 34 | #include <sys/param.h> |
| 35 | #include <sys/systm.h> |
| 36 | #include <sys/namei.h> |
| 37 | #include <sys/kernel.h> |
| 38 | #include <sys/vnode.h> |
| 39 | #include <sys/mount.h> |
| 40 | #include <sys/malloc.h> |
| 41 | |
| 42 | #include <fs/ntfs/ntfs.h> |
| 43 | #include <fs/ntfs/ntfs_compr.h> |
| 44 | |
| 45 | #define GET_UINT16(addr) (*((u_int16_t *)(addr))) |
| 46 | |
| 47 | int |
| 48 | ntfs_uncompblock(u_int8_t *dbuf, 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(dbuf, cbuf + 2, len + 1); |
| 66 | memset(dbuf + len + 1, 0, 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 | dbuf[pos] = dbuf[pos + boff]; |
| 84 | pos++; |
| 85 | } |
| 86 | cpos += 2; |
| 87 | } else { |
| 88 | dbuf[pos++] = cbuf[cpos++]; |
| 89 | } |
| 90 | ctag >>= 1; |
| 91 | } |
| 92 | } |
| 93 | return len + 3; |
| 94 | } |
| 95 | |
| 96 | int |
| 97 | ntfs_uncompunit(struct ntfsmount *ntmp, u_int8_t *uup, u_int8_t *cup) |
| 98 | { |
| 99 | int i; |
| 100 | int off = 0; |
| 101 | int new; |
| 102 | |
| 103 | for (i = 0; i * NTFS_COMPBLOCK_SIZE < ntfs_cntob(NTFS_COMPUNIT_CL); i++) { |
| 104 | new = ntfs_uncompblock(uup + i * NTFS_COMPBLOCK_SIZE, cup + off); |
| 105 | if (new == 0) |
| 106 | return (EINVAL); |
| 107 | off += new; |
| 108 | } |
| 109 | return (0); |
| 110 | } |
| 111 | |