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 "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
56 582 : lzf_decompress (const void *const in_data, unsigned int in_len,
57 : void *out_data, unsigned int out_len)
58 : {
59 582 : u8 const *ip = (const u8 *)in_data;
60 582 : u8 *op = (u8 *)out_data;
61 582 : u8 const *const in_end = ip + in_len;
62 582 : u8 *const out_end = op + out_len;
63 :
64 : do
65 : {
66 31370 : unsigned int ctrl = *ip++;
67 :
68 31370 : if (ctrl < (1 << 5)) /* literal run */
69 : {
70 10431 : ctrl++;
71 :
72 10431 : if (op + ctrl > out_end)
73 : {
74 0 : SET_ERRNO (E2BIG);
75 0 : return 0;
76 : }
77 :
78 : #if CHECK_INPUT
79 10431 : if (ip + ctrl > in_end)
80 : {
81 0 : SET_ERRNO (EINVAL);
82 0 : return 0;
83 : }
84 : #endif
85 :
86 : #ifdef lzf_movsb
87 : lzf_movsb (op, ip, ctrl);
88 : #else
89 : do
90 40021 : *op++ = *ip++;
91 40021 : while (--ctrl);
92 : #endif
93 : }
94 : else /* back reference */
95 : {
96 20939 : unsigned int len = ctrl >> 5;
97 :
98 20939 : u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
99 :
100 : #if CHECK_INPUT
101 20939 : if (ip >= in_end)
102 : {
103 0 : SET_ERRNO (EINVAL);
104 0 : return 0;
105 : }
106 : #endif
107 20939 : if (len == 7)
108 : {
109 28 : len += *ip++;
110 : #if CHECK_INPUT
111 28 : if (ip >= in_end)
112 : {
113 0 : SET_ERRNO (EINVAL);
114 0 : return 0;
115 : }
116 : #endif
117 : }
118 :
119 20939 : ref -= *ip++;
120 :
121 20939 : if (op + len + 2 > out_end)
122 : {
123 0 : SET_ERRNO (E2BIG);
124 0 : return 0;
125 : }
126 :
127 20939 : if (ref < (u8 *)out_data)
128 : {
129 0 : SET_ERRNO (EINVAL);
130 0 : return 0;
131 : }
132 :
133 : #ifdef lzf_movsb
134 : len += 2;
135 : lzf_movsb (op, ref, len);
136 : #else
137 20939 : *op++ = *ref++;
138 20939 : *op++ = *ref++;
139 :
140 : do
141 29430 : *op++ = *ref++;
142 29430 : while (--len);
143 : #endif
144 : }
145 : }
146 31370 : while (ip < in_end);
147 :
148 582 : return op - (u8 *)out_data;
149 : }
150 :
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