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 *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.8	* Copyright (c) 2000-2007 Marc Alexander Lehmann <schmorp@schmorp.de>
3	root	1.1	*
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	pcg	1.4	*
25			* Alternatively, the contents of this file may be used under the terms of
26	root	1.9	* 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	root	1.1	*/
36
37	pcg	1.3	#include "lzfP.h"
38	root	1.1
39	pcg	1.3	#if AVOID_ERRNO
40			# define SET_ERRNO(n)
41			#else
42			# include <errno.h>
43			# define SET_ERRNO(n) errno = (n)
44			#endif
45	root	1.1
46	root	1.7	#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	root	1.1	unsigned int
54			lzf_decompress (const void *const in_data, unsigned int in_len,
55			void *out_data, unsigned int out_len)
56			{
57	pcg	1.3	u8 const ip = (const u8 )in_data;
58			u8 op = (u8 )out_data;
59	root	1.1	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	pcg	1.3	SET_ERRNO (E2BIG);
73	root	1.1	return 0;
74			}
75
76	root	1.6	#if CHECK_INPUT
77			if (ip + ctrl > in_end)
78			{
79			SET_ERRNO (EINVAL);
80			return 0;
81			}
82			#endif
83
84	root	1.7	#ifdef lzf_movsb
85			lzf_movsb (op, ip, ctrl);
86	root	1.1	#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	root	1.6	#if CHECK_INPUT
99			if (ip >= in_end)
100			{
101			SET_ERRNO (EINVAL);
102			return 0;
103			}
104			#endif
105	root	1.1	if (len == 7)
106	root	1.6	{
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	root	1.1	ref -= *ip++;
118
119			if (op + len + 2 > out_end)
120			{
121	pcg	1.3	SET_ERRNO (E2BIG);
122	root	1.1	return 0;
123			}
124
125			if (ref < (u8 *)out_data)
126			{
127	pcg	1.3	SET_ERRNO (EINVAL);
128	root	1.1	return 0;
129			}
130
131	root	1.7	#ifdef lzf_movsb
132			len += 2;
133			lzf_movsb (op, ref, len);
134			#else
135	root	1.1	op++ = ref++;
136			op++ = ref++;
137
138			do
139			op++ = ref++;
140			while (--len);
141	root	1.7	#endif
142	root	1.1	}
143			}
144	root	1.6	while (ip < in_end);
145	root	1.1
146			return op - (u8 *)out_data;
147			}
148