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