summaryrefslogtreecommitdiffstats
path: root/lib/decompress_unlz4.c
blob: 3ad7f3954dfd23b27a87380e75d384f3056d609a (plain)
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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
/*
 * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd
 *
 * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifdef STATIC
#define PREBOOT
#include "lz4/lz4_decompress.c"
#else
#include <linux/decompress/unlz4.h>
#endif
#include <linux/types.h>
#include <linux/lz4.h>
#include <linux/decompress/mm.h>
#include <linux/compiler.h>

#include <asm/unaligned.h>

/*
 * Note: Uncompressed chunk size is used in the compressor side
 * (userspace side for compression).
 * It is hardcoded because there is not proper way to extract it
 * from the binary stream which is generated by the preliminary
 * version of LZ4 tool so far.
 */
#define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20)
#define ARCHIVE_MAGICNUMBER 0x184C2102

STATIC inline int INIT unlz4(u8 *input, int in_len,
				int (*fill) (void *, unsigned int),
				int (*flush) (void *, unsigned int),
				u8 *output, int *posp,
				void (*error) (char *x))
{
	int ret = -1;
	size_t chunksize = 0;
	size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE;
	u8 *inp;
	u8 *inp_start;
	u8 *outp;
	int size = in_len;
#ifdef PREBOOT
	size_t out_len = get_unaligned_le32(input + in_len);
#endif
	size_t dest_len;


	if (output) {
		outp = output;
	} else if (!flush) {
		error("NULL output pointer and no flush function provided");
		goto exit_0;
	} else {
		outp = large_malloc(uncomp_chunksize);
		if (!outp) {
			error("Could not allocate output buffer");
			goto exit_0;
		}
	}

	if (input && fill) {
		error("Both input pointer and fill function provided,");
		goto exit_1;
	} else if (input) {
		inp = input;
	} else if (!fill) {
		error("NULL input pointer and missing fill function");
		goto exit_1;
	} else {
		inp = large_malloc(lz4_compressbound(uncomp_chunksize));
		if (!inp) {
			error("Could not allocate input buffer");
			goto exit_1;
		}
	}
	inp_start = inp;

	if (posp)
		*posp = 0;

	if (fill) {
		size = fill(inp, 4);
		if (size < 4) {
			error("data corrupted");
			goto exit_2;
		}
	}

	chunksize = get_unaligned_le32(inp);
	if (chunksize == ARCHIVE_MAGICNUMBER) {
		if (!fill) {
			inp += 4;
			size -= 4;
		}
	} else {
		error("invalid header");
		goto exit_2;
	}

	if (posp)
		*posp += 4;

	for (;;) {

		if (fill) {
			size = fill(inp, 4);
			if (size == 0)
				break;
			if (size < 4) {
				error("data corrupted");
				goto exit_2;
			}
		}

		chunksize = get_unaligned_le32(inp);
		if (chunksize == ARCHIVE_MAGICNUMBER) {
			if (!fill) {
				inp += 4;
				size -= 4;
			}
			if (posp)
				*posp += 4;
			continue;
		}


		if (posp)
			*posp += 4;

		if (!fill) {
			inp += 4;
			size -= 4;
		} else {
			if (chunksize > lz4_compressbound(uncomp_chunksize)) {
				error("chunk length is longer than allocated");
				goto exit_2;
			}
			size = fill(inp, chunksize);
			if (size < chunksize) {
				error("data corrupted");
				goto exit_2;
			}
		}
#ifdef PREBOOT
		if (out_len >= uncomp_chunksize) {
			dest_len = uncomp_chunksize;
			out_len -= dest_len;
		} else
			dest_len = out_len;
		ret = lz4_decompress(inp, &chunksize, outp, dest_len);
#else
		dest_len = uncomp_chunksize;
		ret = lz4_decompress_unknownoutputsize(inp, chunksize, outp,
				&dest_len);
#endif
		if (ret < 0) {
			error("Decoding failed");
			goto exit_2;
		}

		ret = -1;
		if (flush && flush(outp, dest_len) != dest_len)
			goto exit_2;
		if (output)
			outp += dest_len;
		if (posp)
			*posp += chunksize;

		if (!fill) {
			size -= chunksize;

			if (size == 0)
				break;
			else if (size < 0) {
				error("data corrupted");
				goto exit_2;
			}
			inp += chunksize;
		}
	}

	ret = 0;
exit_2:
	if (!input)
		large_free(inp_start);
exit_1:
	if (!output)
		large_free(outp);
exit_0:
	return ret;
}

#ifdef PREBOOT
STATIC int INIT decompress(unsigned char *buf, int in_len,
			      int(*fill)(void*, unsigned int),
			      int(*flush)(void*, unsigned int),
			      unsigned char *output,
			      int *posp,
			      void(*error)(char *x)
	)
{
	return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
}
#endif