1 /* 2 * Copyright (c) 2000-2010 Marc Alexander Lehmann <schmorp (at) 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 "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 #if USE_REP_MOVSB /* small win on amd, big loss on intel */ 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 #endif 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 switch (ctrl) 90 { 91 case 32: *op++ = *ip++; case 31: *op++ = *ip++; case 30: *op++ = *ip++; case 29: *op++ = *ip++; 92 case 28: *op++ = *ip++; case 27: *op++ = *ip++; case 26: *op++ = *ip++; case 25: *op++ = *ip++; 93 case 24: *op++ = *ip++; case 23: *op++ = *ip++; case 22: *op++ = *ip++; case 21: *op++ = *ip++; 94 case 20: *op++ = *ip++; case 19: *op++ = *ip++; case 18: *op++ = *ip++; case 17: *op++ = *ip++; 95 case 16: *op++ = *ip++; case 15: *op++ = *ip++; case 14: *op++ = *ip++; case 13: *op++ = *ip++; 96 case 12: *op++ = *ip++; case 11: *op++ = *ip++; case 10: *op++ = *ip++; case 9: *op++ = *ip++; 97 case 8: *op++ = *ip++; case 7: *op++ = *ip++; case 6: *op++ = *ip++; case 5: *op++ = *ip++; 98 case 4: *op++ = *ip++; case 3: *op++ = *ip++; case 2: *op++ = *ip++; case 1: *op++ = *ip++; 99 } 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 switch (len) 146 { 147 default: 148 len += 2; 149 150 if (op >= ref + len) 151 { 152 /* disjunct areas */ 153 memcpy (op, ref, len); 154 op += len; 155 } 156 else 157 { 158 /* overlapping, use octte by octte copying */ 159 do 160 *op++ = *ref++; 161 while (--len); 162 } 163 164 break; 165 166 case 9: *op++ = *ref++; 167 case 8: *op++ = *ref++; 168 case 7: *op++ = *ref++; 169 case 6: *op++ = *ref++; 170 case 5: *op++ = *ref++; 171 case 4: *op++ = *ref++; 172 case 3: *op++ = *ref++; 173 case 2: *op++ = *ref++; 174 case 1: *op++ = *ref++; 175 case 0: *op++ = *ref++; /* two octets more */ 176 *op++ = *ref++; 177 } 178 #endif 179 } 180 } 181 while (ip < in_end); 182 183 return op - (u8 *)out_data; 184 } 185 186
