Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
[platform/kernel/linux-rpi.git] / lib / decompress_unlz4.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd
4  *
5  * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
6  */
7
8 #ifdef STATIC
9 #define PREBOOT
10 #include "lz4/lz4_decompress.c"
11 #else
12 #include <linux/decompress/unlz4.h>
13 #endif
14 #include <linux/types.h>
15 #include <linux/lz4.h>
16 #include <linux/decompress/mm.h>
17 #include <linux/compiler.h>
18
19 #include <asm/unaligned.h>
20
21 /*
22  * Note: Uncompressed chunk size is used in the compressor side
23  * (userspace side for compression).
24  * It is hardcoded because there is not proper way to extract it
25  * from the binary stream which is generated by the preliminary
26  * version of LZ4 tool so far.
27  */
28 #define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20)
29 #define ARCHIVE_MAGICNUMBER 0x184C2102
30
31 STATIC inline int INIT unlz4(u8 *input, long in_len,
32                                 long (*fill)(void *, unsigned long),
33                                 long (*flush)(void *, unsigned long),
34                                 u8 *output, long *posp,
35                                 void (*error) (char *x))
36 {
37         int ret = -1;
38         size_t chunksize = 0;
39         size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE;
40         u8 *inp;
41         u8 *inp_start;
42         u8 *outp;
43         long size = in_len;
44 #ifdef PREBOOT
45         size_t out_len = get_unaligned_le32(input + in_len);
46 #endif
47         size_t dest_len;
48
49
50         if (output) {
51                 outp = output;
52         } else if (!flush) {
53                 error("NULL output pointer and no flush function provided");
54                 goto exit_0;
55         } else {
56                 outp = large_malloc(uncomp_chunksize);
57                 if (!outp) {
58                         error("Could not allocate output buffer");
59                         goto exit_0;
60                 }
61         }
62
63         if (input && fill) {
64                 error("Both input pointer and fill function provided,");
65                 goto exit_1;
66         } else if (input) {
67                 inp = input;
68         } else if (!fill) {
69                 error("NULL input pointer and missing fill function");
70                 goto exit_1;
71         } else {
72                 inp = large_malloc(LZ4_compressBound(uncomp_chunksize));
73                 if (!inp) {
74                         error("Could not allocate input buffer");
75                         goto exit_1;
76                 }
77         }
78         inp_start = inp;
79
80         if (posp)
81                 *posp = 0;
82
83         if (fill) {
84                 size = fill(inp, 4);
85                 if (size < 4) {
86                         error("data corrupted");
87                         goto exit_2;
88                 }
89         }
90
91         chunksize = get_unaligned_le32(inp);
92         if (chunksize == ARCHIVE_MAGICNUMBER) {
93                 if (!fill) {
94                         inp += 4;
95                         size -= 4;
96                 }
97         } else {
98                 error("invalid header");
99                 goto exit_2;
100         }
101
102         if (posp)
103                 *posp += 4;
104
105         for (;;) {
106
107                 if (fill) {
108                         size = fill(inp, 4);
109                         if (size == 0)
110                                 break;
111                         if (size < 4) {
112                                 error("data corrupted");
113                                 goto exit_2;
114                         }
115                 } else if (size < 4) {
116                         /* empty or end-of-file */
117                         goto exit_3;
118                 }
119
120                 chunksize = get_unaligned_le32(inp);
121                 if (chunksize == ARCHIVE_MAGICNUMBER) {
122                         if (!fill) {
123                                 inp += 4;
124                                 size -= 4;
125                         }
126                         if (posp)
127                                 *posp += 4;
128                         continue;
129                 }
130
131                 if (!fill && chunksize == 0) {
132                         /* empty or end-of-file */
133                         goto exit_3;
134                 }
135
136                 if (posp)
137                         *posp += 4;
138
139                 if (!fill) {
140                         inp += 4;
141                         size -= 4;
142                 } else {
143                         if (chunksize > LZ4_compressBound(uncomp_chunksize)) {
144                                 error("chunk length is longer than allocated");
145                                 goto exit_2;
146                         }
147                         size = fill(inp, chunksize);
148                         if (size < chunksize) {
149                                 error("data corrupted");
150                                 goto exit_2;
151                         }
152                 }
153 #ifdef PREBOOT
154                 if (out_len >= uncomp_chunksize) {
155                         dest_len = uncomp_chunksize;
156                         out_len -= dest_len;
157                 } else
158                         dest_len = out_len;
159
160                 ret = LZ4_decompress_fast(inp, outp, dest_len);
161                 chunksize = ret;
162 #else
163                 dest_len = uncomp_chunksize;
164
165                 ret = LZ4_decompress_safe(inp, outp, chunksize, dest_len);
166                 dest_len = ret;
167 #endif
168                 if (ret < 0) {
169                         error("Decoding failed");
170                         goto exit_2;
171                 }
172
173                 ret = -1;
174                 if (flush && flush(outp, dest_len) != dest_len)
175                         goto exit_2;
176                 if (output)
177                         outp += dest_len;
178                 if (posp)
179                         *posp += chunksize;
180
181                 if (!fill) {
182                         size -= chunksize;
183
184                         if (size == 0)
185                                 break;
186                         else if (size < 0) {
187                                 error("data corrupted");
188                                 goto exit_2;
189                         }
190                         inp += chunksize;
191                 }
192         }
193
194 exit_3:
195         ret = 0;
196 exit_2:
197         if (!input)
198                 large_free(inp_start);
199 exit_1:
200         if (!output)
201                 large_free(outp);
202 exit_0:
203         return ret;
204 }
205
206 #ifdef PREBOOT
207 STATIC int INIT __decompress(unsigned char *buf, long in_len,
208                               long (*fill)(void*, unsigned long),
209                               long (*flush)(void*, unsigned long),
210                               unsigned char *output, long out_len,
211                               long *posp,
212                               void (*error)(char *x)
213         )
214 {
215         return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
216 }
217 #endif