liblzf/lzf_d.c

/*
 * Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp@schmorp.de>
 * 
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 * 
 *   1.  Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 * 
 *   2.  Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License ("GPL") version 2 or any later version,
 * in which case the provisions of the GPL are applicable instead of
 * the above. If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use your
 * version of this file under the BSD license, indicate your decision
 * by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL. If you do not delete the
 * provisions above, a recipient may use your version of this file under
 * either the BSD or the GPL.
 */

#include "lzfP.h"

#if AVOID_ERRNO
# define SET_ERRNO(n)
#else
# include <errno.h>
# define SET_ERRNO(n) errno = (n)
#endif

#if (__i386 || __amd64) && __GNUC__ >= 3
# define lzf_movsb(dst, src, len)                \
   asm ("rep movsb"                              \
        : "=D" (dst), "=S" (src), "=c" (len)     \
        :  "0" (dst),  "1" (src),  "2" (len));
#endif

unsigned int 
lzf_decompress (const void *const in_data,  unsigned int in_len,
                void             *out_data, unsigned int out_len)
{
  u8 const *ip = (const u8 *)in_data;
  u8       *op = (u8 *)out_data;
  u8 const *const in_end  = ip + in_len;
  u8       *const out_end = op + out_len;

  do
    {
      unsigned int ctrl = *ip++;

      if (ctrl < (1 << 5)) /* literal run */
        {
          ctrl++;

          if (op + ctrl > out_end)
            {
              SET_ERRNO (E2BIG);
              return 0;
            }

#if CHECK_INPUT
          if (ip + ctrl > in_end)
            {
              SET_ERRNO (EINVAL);
              return 0;
            }
#endif

#ifdef lzf_movsb
          lzf_movsb (op, ip, ctrl);
#else
          do
            *op++ = *ip++;
          while (--ctrl);
#endif
        }
      else /* back reference */
        {
          unsigned int len = ctrl >> 5;

          u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;

#if CHECK_INPUT
          if (ip >= in_end)
            {
              SET_ERRNO (EINVAL);
              return 0;
            }
#endif
          if (len == 7)
            {
              len += *ip++;
#if CHECK_INPUT
              if (ip >= in_end)
                {
                  SET_ERRNO (EINVAL);
                  return 0;
                }
#endif
            }

          ref -= *ip++;

          if (op + len + 2 > out_end)
            {
              SET_ERRNO (E2BIG);
              return 0;
            }

          if (ref < (u8 *)out_data)
            {
              SET_ERRNO (EINVAL);
              return 0;
            }

#ifdef lzf_movsb
          len += 2;
          lzf_movsb (op, ref, len);
#else
          *op++ = *ref++;
          *op++ = *ref++;

          do
            *op++ = *ref++;
          while (--len);
#endif
        }
    }
  while (ip < in_end);

  return op - (u8 *)out_data;
}

Revision:	1.9
Committed:	Mon Nov 5 23:28:40 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-3_5, rel-3_4, rel-3_3, rel-3_1, rel-3_0
Changes since 1.8:	+9 -8 lines
Log Message:	* empty log message *
#	Content
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	#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