liblzf/lzf_d.c

/*
 * Copyright (c) 2000-2005 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.
 * 
 *   3.  The name of the author may not be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * 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 version 2 (the "GPL"), 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:	1.7
Committed:	Thu Jun 21 22:11:34 2007 UTC (16 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.6:	+14 -4 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.5	* Copyright (c) 2000-2005 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			* 3. The name of the author may not be used to endorse or promote products
15			* derived from this software without specific prior written permission.
16			*
17			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26			* OF THE POSSIBILITY OF SUCH DAMAGE.
27	pcg	1.4	*
28			* Alternatively, the contents of this file may be used under the terms of
29			* the GNU General Public License version 2 (the "GPL"), in which case the
30			* provisions of the GPL are applicable instead of the above. If you wish to
31			* allow the use of your version of this file only under the terms of the
32			* GPL and not to allow others to use your version of this file under the
33			* BSD license, indicate your decision by deleting the provisions above and
34			* replace them with the notice and other provisions required by the GPL. If
35			* you do not delete the provisions above, a recipient may use your version
36			* of this file under either the BSD or the GPL.
37	root	1.1	*/
38
39	pcg	1.3	#include "lzfP.h"
40	root	1.1
41	pcg	1.3	#if AVOID_ERRNO
42			# define SET_ERRNO(n)
43			#else
44			# include <errno.h>
45			# define SET_ERRNO(n) errno = (n)
46			#endif
47	root	1.1
48	root	1.7	#if (__i386 \|\| __amd64) && __GNUC__ >= 3
49			# define lzf_movsb(dst, src, len) \
50			asm ("rep movsb" \
51			: "=D" (dst), "=S" (src), "=c" (len) \
52			: "0" (dst), "1" (src), "2" (len));
53			#endif
54
55	root	1.1	unsigned int
56			lzf_decompress (const void *const in_data, unsigned int in_len,
57			void *out_data, unsigned int out_len)
58			{
59	pcg	1.3	u8 const ip = (const u8 )in_data;
60			u8 op = (u8 )out_data;
61	root	1.1	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	pcg	1.3	SET_ERRNO (E2BIG);
75	root	1.1	return 0;
76			}
77
78	root	1.6	#if CHECK_INPUT
79			if (ip + ctrl > in_end)
80			{
81			SET_ERRNO (EINVAL);
82			return 0;
83			}
84			#endif
85
86	root	1.7	#ifdef lzf_movsb
87			lzf_movsb (op, ip, ctrl);
88	root	1.1	#else
89			do
90			op++ = ip++;
91			while (--ctrl);
92			#endif
93			}
94			else /* back reference */
95			{
96			unsigned int len = ctrl >> 5;
97
98			u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
99
100	root	1.6	#if CHECK_INPUT
101			if (ip >= in_end)
102			{
103			SET_ERRNO (EINVAL);
104			return 0;
105			}
106			#endif
107	root	1.1	if (len == 7)
108	root	1.6	{
109			len += *ip++;
110			#if CHECK_INPUT
111			if (ip >= in_end)
112			{
113			SET_ERRNO (EINVAL);
114			return 0;
115			}
116			#endif
117			}
118
119	root	1.1	ref -= *ip++;
120
121			if (op + len + 2 > out_end)
122			{
123	pcg	1.3	SET_ERRNO (E2BIG);
124	root	1.1	return 0;
125			}
126
127			if (ref < (u8 *)out_data)
128			{
129	pcg	1.3	SET_ERRNO (EINVAL);
130	root	1.1	return 0;
131			}
132
133	root	1.7	#ifdef lzf_movsb
134			len += 2;
135			lzf_movsb (op, ref, len);
136			#else
137	root	1.1	op++ = ref++;
138			op++ = ref++;
139
140			do
141			op++ = ref++;
142			while (--len);
143	root	1.7	#endif
144	root	1.1	}
145			}
146	root	1.6	while (ip < in_end);
147	root	1.1
148			return op - (u8 *)out_data;
149			}
150