1 /* 2 * Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp@schmorp.de> 3 * 4 * Redistribution and use in source and binary forms, with or without modifica- 5 * tion, are permitted provided that the following conditions are met: 6 * 7 * 1. Redistributions of source code must retain the above copyright notice, 8 * this list of conditions and the following disclaimer. 9 * 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 15 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- 16 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 17 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- 18 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 20 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 21 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- 22 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 23 * OF THE POSSIBILITY OF SUCH DAMAGE. 24 * 25 * Alternatively, the contents of this file may be used under the terms of 26 * the GNU General Public License ("GPL") version 2 or any later version, 27 * in which case the provisions of the GPL are applicable instead of 28 * the above. If you wish to allow the use of your version of this file 29 * only under the terms of the GPL and not to allow others to use your 30 * version of this file under the BSD license, indicate your decision 31 * by deleting the provisions above and replace them with the notice 32 * and other provisions required by the GPL. If you do not delete the 33 * provisions above, a recipient may use your version of this file under 34 * either the BSD or the GPL. 35 */ 36 37 #if defined(_KERNEL) || defined (_STANDALONE) 38 #include <lib/libkern/libkern.h> 39 #include <sys/systm.h> 40 #include "lzfP.h" 41 #else 42 #include "lzf.h" 43 #endif 44 45 #ifdef _KERNEL 46 # define SET_ERRNO(n) panic("lzf decompression failure: %s", #n) 47 #else 48 # ifdef AVOID_ERRNO 49 # define SET_ERRNO(n) 50 # else 51 # include <errno.h> 52 # define SET_ERRNO(n) errno = (n) 53 # endif 54 #endif 55 56 #if (__i386 || __amd64) && __GNUC__ >= 3 57 # define lzf_movsb(dst, src, len) \ 58 asm ("rep movsb" \ 59 : "=D" (dst), "=S" (src), "=c" (len) \ 60 : "0" (dst), "1" (src), "2" (len)); 61 #endif 62 63 unsigned int 64 lzf_decompress (const void *const in_data, unsigned int in_len, 65 void *out_data, unsigned int out_len) 66 { 67 u8 const *ip = (const u8 *)in_data; 68 u8 *op = (u8 *)out_data; 69 u8 const *const in_end = ip + in_len; 70 u8 *const out_end = op + out_len; 71 72 do 73 { 74 unsigned int ctrl = *ip++; 75 76 if (ctrl < (1 << 5)) /* literal run */ 77 { 78 ctrl++; 79 80 if (op + ctrl > out_end) 81 { 82 SET_ERRNO (E2BIG); 83 return 0; 84 } 85 86 #if CHECK_INPUT 87 if (ip + ctrl > in_end) 88 { 89 SET_ERRNO (EINVAL); 90 return 0; 91 } 92 #endif 93 94 #ifdef lzf_movsb 95 lzf_movsb (op, ip, ctrl); 96 #else 97 do 98 *op++ = *ip++; 99 while (--ctrl); 100 #endif 101 } 102 else /* back reference */ 103 { 104 unsigned int len = ctrl >> 5; 105 106 u8 *ref = op - ((ctrl & 0x1f) << 8) - 1; 107 108 #if CHECK_INPUT 109 if (ip >= in_end) 110 { 111 SET_ERRNO (EINVAL); 112 return 0; 113 } 114 #endif 115 if (len == 7) 116 { 117 len += *ip++; 118 #if CHECK_INPUT 119 if (ip >= in_end) 120 { 121 SET_ERRNO (EINVAL); 122 return 0; 123 } 124 #endif 125 } 126 127 ref -= *ip++; 128 129 if (op + len + 2 > out_end) 130 { 131 SET_ERRNO (E2BIG); 132 return 0; 133 } 134 135 if (ref < (u8 *)out_data) 136 { 137 SET_ERRNO (EINVAL); 138 return 0; 139 } 140 141 #ifdef lzf_movsb 142 len += 2; 143 lzf_movsb (op, ref, len); 144 #else 145 *op++ = *ref++; 146 *op++ = *ref++; 147 148 do 149 *op++ = *ref++; 150 while (--len); 151 #endif 152 } 153 } 154 while (ip < in_end); 155 156 return (unsigned)(op - (u8 *)out_data); 157 } 158 159