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

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

#if USE_MEMCPY
          memcpy (op, ip, ctrl);
          op += ctrl;
          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;
            }

          *op++ = *ref++;
          *op++ = *ref++;

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

  return op - (u8 *)out_data;
}

Revision:	1.6
Committed:	Fri Jul 7 15:34:11 2006 UTC (17 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-2_0, rel-1_7, rel-1_6
Changes since 1.5:	+27 -3 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* Copyright (c) 2000-2005 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	* 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	*
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	*/
38
39	#include "lzfP.h"
40
41	#if AVOID_ERRNO
42	# define SET_ERRNO(n)
43	#else
44	# include <errno.h>
45	# define SET_ERRNO(n) errno = (n)
46	#endif
47
48	unsigned int
49	lzf_decompress (const void *const in_data, unsigned int in_len,
50	void *out_data, unsigned int out_len)
51	{
52	u8 const ip = (const u8 )in_data;
53	u8 op = (u8 )out_data;
54	u8 const *const in_end = ip + in_len;
55	u8 *const out_end = op + out_len;
56
57	do
58	{
59	unsigned int ctrl = *ip++;
60
61	if (ctrl < (1 << 5)) /* literal run */
62	{
63	ctrl++;
64
65	if (op + ctrl > out_end)
66	{
67	SET_ERRNO (E2BIG);
68	return 0;
69	}
70
71	#if CHECK_INPUT
72	if (ip + ctrl > in_end)
73	{
74	SET_ERRNO (EINVAL);
75	return 0;
76	}
77	#endif
78
79	#if USE_MEMCPY
80	memcpy (op, ip, ctrl);
81	op += ctrl;
82	ip += ctrl;
83	#else
84	do
85	op++ = ip++;
86	while (--ctrl);
87	#endif
88	}
89	else /* back reference */
90	{
91	unsigned int len = ctrl >> 5;
92
93	u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
94
95	#if CHECK_INPUT
96	if (ip >= in_end)
97	{
98	SET_ERRNO (EINVAL);
99	return 0;
100	}
101	#endif
102	if (len == 7)
103	{
104	len += *ip++;
105	#if CHECK_INPUT
106	if (ip >= in_end)
107	{
108	SET_ERRNO (EINVAL);
109	return 0;
110	}
111	#endif
112	}
113
114	ref -= *ip++;
115
116	if (op + len + 2 > out_end)
117	{
118	SET_ERRNO (E2BIG);
119	return 0;
120	}
121
122	if (ref < (u8 *)out_data)
123	{
124	SET_ERRNO (EINVAL);
125	return 0;
126	}
127
128	op++ = ref++;
129	op++ = ref++;
130
131	do
132	op++ = ref++;
133	while (--len);
134	}
135	}
136	while (ip < in_end);
137
138	return op - (u8 *)out_data;
139	}
140