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 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:	1.8
Committed:	Fri Nov 2 12:39:20 2007 UTC (16 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-2_1
Changes since 1.7:	+1 -4 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 version 2 (the "GPL"), in which case the
27	* provisions of the GPL are applicable instead of the above. If you wish to
28	* allow the use of your version of this file only under the terms of the
29	* GPL and not to allow others to use your version of this file under the
30	* BSD license, indicate your decision by deleting the provisions above and
31	* replace them with the notice and other provisions required by the GPL. If
32	* you do not delete the provisions above, a recipient may use your version
33	* of this file under either the BSD or the GPL.
34	*/
35
36	#include "lzfP.h"
37
38	#if AVOID_ERRNO
39	# define SET_ERRNO(n)
40	#else
41	# include <errno.h>
42	# define SET_ERRNO(n) errno = (n)
43	#endif
44
45	#if (__i386 \|\| __amd64) && __GNUC__ >= 3
46	# define lzf_movsb(dst, src, len) \
47	asm ("rep movsb" \
48	: "=D" (dst), "=S" (src), "=c" (len) \
49	: "0" (dst), "1" (src), "2" (len));
50	#endif
51
52	unsigned int
53	lzf_decompress (const void *const in_data, unsigned int in_len,
54	void *out_data, unsigned int out_len)
55	{
56	u8 const ip = (const u8 )in_data;
57	u8 op = (u8 )out_data;
58	u8 const *const in_end = ip + in_len;
59	u8 *const out_end = op + out_len;
60
61	do
62	{
63	unsigned int ctrl = *ip++;
64
65	if (ctrl < (1 << 5)) /* literal run */
66	{
67	ctrl++;
68
69	if (op + ctrl > out_end)
70	{
71	SET_ERRNO (E2BIG);
72	return 0;
73	}
74
75	#if CHECK_INPUT
76	if (ip + ctrl > in_end)
77	{
78	SET_ERRNO (EINVAL);
79	return 0;
80	}
81	#endif
82
83	#ifdef lzf_movsb
84	lzf_movsb (op, ip, ctrl);
85	#else
86	do
87	op++ = ip++;
88	while (--ctrl);
89	#endif
90	}
91	else /* back reference */
92	{
93	unsigned int len = ctrl >> 5;
94
95	u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
96
97	#if CHECK_INPUT
98	if (ip >= in_end)
99	{
100	SET_ERRNO (EINVAL);
101	return 0;
102	}
103	#endif
104	if (len == 7)
105	{
106	len += *ip++;
107	#if CHECK_INPUT
108	if (ip >= in_end)
109	{
110	SET_ERRNO (EINVAL);
111	return 0;
112	}
113	#endif
114	}
115
116	ref -= *ip++;
117
118	if (op + len + 2 > out_end)
119	{
120	SET_ERRNO (E2BIG);
121	return 0;
122	}
123
124	if (ref < (u8 *)out_data)
125	{
126	SET_ERRNO (EINVAL);
127	return 0;
128	}
129
130	#ifdef lzf_movsb
131	len += 2;
132	lzf_movsb (op, ref, len);
133	#else
134	op++ = ref++;
135	op++ = ref++;
136
137	do
138	op++ = ref++;
139	while (--len);
140	#endif
141	}
142	}
143	while (ip < in_end);
144
145	return op - (u8 *)out_data;
146	}
147