1 /*
2 * Copyright (c) 2000-2010 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 "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
lzf_decompress(const void * const in_data,unsigned int in_len,void * out_data,unsigned int out_len)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