1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/*
* Copyright 2015 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, 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.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 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 OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <assert.h>
#include <endian.h>
#include <libpayload.h>
#include <lz4.h>
/* LZ4 comes with its own supposedly portable memory access functions, but they
* seem to be very inefficient in practice (at least on ARM64). Since libpayload
* knows about endinaness and allows some basic assumptions (such as unaligned
* access support), we can easily write the ones we need ourselves. */
static u16 LZ4_readLE16(const void *src) { return le16toh(*(u16 *)src); }
static void LZ4_copy4(void *dst, const void *src) { *(u32 *)dst = *(u32 *)src; }
static void LZ4_copy8(void *dst, const void *src) { *(u64 *)dst = *(u64 *)src; }
typedef uint8_t BYTE;
typedef uint16_t U16;
typedef uint32_t U32;
typedef int32_t S32;
typedef uint64_t U64;
#define FORCE_INLINE static inline __attribute__((always_inline))
#define likely(expr) __builtin_expect((expr) != 0, 1)
#define unlikely(expr) __builtin_expect((expr) != 0, 0)
/* Unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */
#include "lz4.c" /* #include for inlining, do not link! */
#define LZ4F_MAGICNUMBER 0x184D2204
struct lz4_frame_header {
u32 magic;
union {
u8 flags;
struct {
u8 reserved0 : 2;
u8 has_content_checksum : 1;
u8 has_content_size : 1;
u8 has_block_checksum : 1;
u8 independent_blocks : 1;
u8 version : 2;
};
};
union {
u8 block_descriptor;
struct {
u8 reserved1 : 4;
u8 max_block_size : 3;
u8 reserved2 : 1;
};
};
/* + u64 content_size iff has_content_size is set */
/* + u8 header_checksum */
} __attribute__((packed));
struct lz4_block_header {
union {
u32 raw;
struct {
u32 size : 31;
u32 not_compressed : 1;
};
};
/* + size bytes of data */
/* + u32 block_checksum iff has_block_checksum is set */
} __attribute__((packed));
size_t ulz4fn(const void *src, size_t srcn, void *dst, size_t dstn)
{
const void *in = src;
void *out = dst;
int has_block_checksum;
{ /* With in-place decompression the header may become invalid later. */
const struct lz4_frame_header *h = in;
if (srcn < sizeof(*h) + sizeof(u64) + sizeof(u8))
return 0; /* input overrun */
/* We assume there's always only a single, standard frame. */
if (le32toh(h->magic) != LZ4F_MAGICNUMBER || h->version != 1)
return 0; /* unknown format */
if (h->reserved0 || h->reserved1 || h->reserved2)
return 0; /* reserved must be zero */
if (!h->independent_blocks)
return 0; /* we don't support block dependency */
has_block_checksum = h->has_block_checksum;
in += sizeof(*h);
if (h->has_content_size)
in += sizeof(u64);
in += sizeof(u8);
}
while (1) {
struct lz4_block_header b = { .raw = le32toh(*(u32 *)in) };
in += sizeof(struct lz4_block_header);
if (in - src + b.size > srcn)
return 0; /* input overrun */
if (!b.size)
return out - dst; /* decompression successful */
if (b.not_compressed) {
memcpy(out, in, b.size);
out += b.size;
} else {
/* constant folding essential, do not touch params! */
int ret = LZ4_decompress_generic(in, out, b.size,
dst + dstn - out, endOnInputSize,
full, 0, noDict, out, NULL, 0);
if (ret < 0)
return 0; /* decompression error */
else
out += ret;
}
in += b.size;
if (has_block_checksum)
in += sizeof(u32);
}
}
size_t ulz4f(const void *src, void *dst)
{
/* LZ4 uses signed size parameters, so can't just use ((u32)-1) here. */
return ulz4fn(src, 1*GiB, dst, 1*GiB);
}
|
