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 #if defined(_KERNEL) || defined (_STANDALONE)
38 #include <lib/libkern/libkern.h>
39 #include <sys/systm.h>
40 #include "lzfP.h"
41 #else
42 #include "lzf.h"
43 #endif
44
45 #ifdef _KERNEL
46 # define SET_ERRNO(n) panic("lzf decompression failure: %s", #n)
47 #else
48 # ifdef AVOID_ERRNO
49 # define SET_ERRNO(n)
50 # else
51 # include <errno.h>
52 # define SET_ERRNO(n) errno = (n)
53 # endif
54 #endif
55
56 #if (__i386 || __amd64) && __GNUC__ >= 3
57 # define lzf_movsb(dst, src, len) \
58 asm ("rep movsb" \
59 : "=D" (dst), "=S" (src), "=c" (len) \
60 : "0" (dst), "1" (src), "2" (len));
61 #endif
62
63 unsigned int
lzf_decompress(const void * const in_data,unsigned int in_len,void * out_data,unsigned int out_len)64 lzf_decompress (const void *const in_data, unsigned int in_len,
65 void *out_data, unsigned int out_len)
66 {
67 u8 const *ip = (const u8 *)in_data;
68 u8 *op = (u8 *)out_data;
69 u8 const *const in_end = ip + in_len;
70 u8 *const out_end = op + out_len;
71
72 do
73 {
74 unsigned int ctrl = *ip++;
75
76 if (ctrl < (1 << 5)) /* literal run */
77 {
78 ctrl++;
79
80 if (op + ctrl > out_end)
81 {
82 SET_ERRNO (E2BIG);
83 return 0;
84 }
85
86 #if CHECK_INPUT
87 if (ip + ctrl > in_end)
88 {
89 SET_ERRNO (EINVAL);
90 return 0;
91 }
92 #endif
93
94 #ifdef lzf_movsb
95 lzf_movsb (op, ip, ctrl);
96 #else
97 do
98 *op++ = *ip++;
99 while (--ctrl);
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 *op++ = *ref++;
146 *op++ = *ref++;
147
148 do
149 *op++ = *ref++;
150 while (--len);
151 #endif
152 }
153 }
154 while (ip < in_end);
155
156 return (unsigned)(op - (u8 *)out_data);
157 }
158
159