1 /* 2 * Copyright (c) 2000-2007 Marc Alexander Lehmann <[email protected]> 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 #include "lzfP.h" 38 39 #if AVOID_ERRNO 40 # define SET_ERRNO(n) 41 #else 42 # include <errno.h> 43 # define SET_ERRNO(n) errno = (n) 44 #endif 45 46 /* 47 #if (__i386 || __amd64) && __GNUC__ >= 3 48 # define lzf_movsb(dst, src, len) \ 49 asm ("rep movsb" \ 50 : "=D" (dst), "=S" (src), "=c" (len) \ 51 : "0" (dst), "1" (src), "2" (len)); 52 #endif 53 */ 54 55 unsigned int 56 lzf_decompress (const void *const in_data, unsigned int in_len, 57 void *out_data, unsigned int out_len) 58 { 59 u8 const *ip = (const u8 *)in_data; 60 u8 *op = (u8 *)out_data; 61 u8 const *const in_end = ip + in_len; 62 u8 *const out_end = op + out_len; 63 64 do 65 { 66 unsigned int ctrl = *ip++; 67 68 if (ctrl < (1 << 5)) /* literal run */ 69 { 70 ctrl++; 71 72 if (op + ctrl > out_end) 73 { 74 SET_ERRNO (E2BIG); 75 return 0; 76 } 77 78 #if CHECK_INPUT 79 if (ip + ctrl > in_end) 80 { 81 SET_ERRNO (EINVAL); 82 return 0; 83 } 84 #endif 85 86 #ifdef lzf_movsb 87 lzf_movsb (op, ip, ctrl); 88 #else 89 do 90 *op++ = *ip++; 91 while (--ctrl); 92 #endif 93 } 94 else /* back reference */ 95 { 96 unsigned int len = ctrl >> 5; 97 98 u8 *ref = op - ((ctrl & 0x1f) << 8) - 1; 99 100 #if CHECK_INPUT 101 if (ip >= in_end) 102 { 103 SET_ERRNO (EINVAL); 104 return 0; 105 } 106 #endif 107 if (len == 7) 108 { 109 len += *ip++; 110 #if CHECK_INPUT 111 if (ip >= in_end) 112 { 113 SET_ERRNO (EINVAL); 114 return 0; 115 } 116 #endif 117 } 118 119 ref -= *ip++; 120 121 if (op + len + 2 > out_end) 122 { 123 SET_ERRNO (E2BIG); 124 return 0; 125 } 126 127 if (ref < (u8 *)out_data) 128 { 129 SET_ERRNO (EINVAL); 130 return 0; 131 } 132 133 #ifdef lzf_movsb 134 len += 2; 135 lzf_movsb (op, ref, len); 136 #else 137 *op++ = *ref++; 138 *op++ = *ref++; 139 140 do 141 *op++ = *ref++; 142 while (--len); 143 #endif 144 } 145 } 146 while (ip < in_end); 147 148 return op - (u8 *)out_data; 149 } 150 151