1 // SPDX-License-Identifier: GPL-2.0+
2 #include "decompress.h"
3
4 #if IS_ENABLED(CONFIG_ZLIB)
5 #include <u-boot/zlib.h>
6
7 /* report a zlib or i/o error */
zerr(int ret)8 static int zerr(int ret)
9 {
10 switch (ret) {
11 case Z_STREAM_ERROR:
12 return -EINVAL;
13 case Z_DATA_ERROR:
14 return -EIO;
15 case Z_MEM_ERROR:
16 return -ENOMEM;
17 case Z_ERRNO:
18 default:
19 return -EFAULT;
20 }
21 }
22
z_erofs_decompress_deflate(struct z_erofs_decompress_req * rq)23 static int z_erofs_decompress_deflate(struct z_erofs_decompress_req *rq)
24 {
25 u8 *dest = (u8 *)rq->out;
26 u8 *src = (u8 *)rq->in;
27 u8 *buff = NULL;
28 unsigned int inputmargin = 0;
29 z_stream strm;
30 int ret;
31
32 while (!src[inputmargin & (erofs_blksiz() - 1)])
33 if (!(++inputmargin & (erofs_blksiz() - 1)))
34 break;
35
36 if (inputmargin >= rq->inputsize)
37 return -EFSCORRUPTED;
38
39 if (rq->decodedskip) {
40 buff = malloc(rq->decodedlength);
41 if (!buff)
42 return -ENOMEM;
43 dest = buff;
44 }
45
46 /* allocate inflate state */
47 strm.zalloc = Z_NULL;
48 strm.zfree = Z_NULL;
49 strm.opaque = Z_NULL;
50 strm.avail_in = 0;
51 strm.next_in = Z_NULL;
52 ret = inflateInit2(&strm, -15);
53 if (ret != Z_OK) {
54 free(buff);
55 return zerr(ret);
56 }
57
58 strm.next_in = src + inputmargin;
59 strm.avail_in = rq->inputsize - inputmargin;
60 strm.next_out = dest;
61 strm.avail_out = rq->decodedlength;
62
63 ret = inflate(&strm, rq->partial_decoding ? Z_SYNC_FLUSH : Z_FINISH);
64 if (ret != Z_STREAM_END || strm.total_out != rq->decodedlength) {
65 if (ret != Z_OK || !rq->partial_decoding) {
66 ret = zerr(ret);
67 goto out_inflate_end;
68 }
69 }
70
71 if (rq->decodedskip)
72 memcpy(rq->out, dest + rq->decodedskip,
73 rq->decodedlength - rq->decodedskip);
74
75 out_inflate_end:
76 inflateEnd(&strm);
77 if (buff)
78 free(buff);
79 return ret;
80 }
81 #endif
82
83 #if IS_ENABLED(CONFIG_LZ4)
84 #include <u-boot/lz4.h>
z_erofs_decompress_lz4(struct z_erofs_decompress_req * rq)85 static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq)
86 {
87 int ret = 0;
88 char *dest = rq->out;
89 char *src = rq->in;
90 char *buff = NULL;
91 bool support_0padding = false;
92 unsigned int inputmargin = 0;
93
94 if (erofs_sb_has_lz4_0padding()) {
95 support_0padding = true;
96
97 while (!src[inputmargin & (erofs_blksiz() - 1)])
98 if (!(++inputmargin & (erofs_blksiz() - 1)))
99 break;
100
101 if (inputmargin >= rq->inputsize)
102 return -EIO;
103 }
104
105 if (rq->decodedskip) {
106 buff = malloc(rq->decodedlength);
107 if (!buff)
108 return -ENOMEM;
109 dest = buff;
110 }
111
112 if (rq->partial_decoding || !support_0padding)
113 ret = LZ4_decompress_safe_partial(src + inputmargin, dest,
114 rq->inputsize - inputmargin,
115 rq->decodedlength, rq->decodedlength);
116 else
117 ret = LZ4_decompress_safe(src + inputmargin, dest,
118 rq->inputsize - inputmargin,
119 rq->decodedlength);
120
121 if (ret != (int)rq->decodedlength) {
122 erofs_err("failed to %s decompress %d in[%u, %u] out[%u]",
123 rq->partial_decoding ? "partial" : "full",
124 ret, rq->inputsize, inputmargin, rq->decodedlength);
125 ret = -EIO;
126 goto out;
127 }
128
129 if (rq->decodedskip)
130 memcpy(rq->out, dest + rq->decodedskip,
131 rq->decodedlength - rq->decodedskip);
132
133 out:
134 if (buff)
135 free(buff);
136
137 return ret;
138 }
139 #endif
140
z_erofs_decompress(struct z_erofs_decompress_req * rq)141 int z_erofs_decompress(struct z_erofs_decompress_req *rq)
142 {
143 if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) {
144 unsigned int count, rightpart, skip;
145
146 /* XXX: should support inputsize >= erofs_blksiz() later */
147 if (rq->inputsize > erofs_blksiz())
148 return -EFSCORRUPTED;
149
150 if (rq->decodedlength > erofs_blksiz())
151 return -EFSCORRUPTED;
152
153 if (rq->decodedlength < rq->decodedskip)
154 return -EFSCORRUPTED;
155
156 count = rq->decodedlength - rq->decodedskip;
157 skip = erofs_blkoff(rq->interlaced_offset + rq->decodedskip);
158 rightpart = min(erofs_blksiz() - skip, count);
159 memcpy(rq->out, rq->in + skip, rightpart);
160 memcpy(rq->out + rightpart, rq->in, count - rightpart);
161 return 0;
162 } else if (rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
163 if (rq->decodedlength > rq->inputsize)
164 return -EFSCORRUPTED;
165
166 DBG_BUGON(rq->decodedlength < rq->decodedskip);
167 memcpy(rq->out, rq->in + rq->decodedskip,
168 rq->decodedlength - rq->decodedskip);
169 return 0;
170 }
171
172 #if IS_ENABLED(CONFIG_LZ4)
173 if (rq->alg == Z_EROFS_COMPRESSION_LZ4)
174 return z_erofs_decompress_lz4(rq);
175 #endif
176 #if IS_ENABLED(CONFIG_ZLIB)
177 if (rq->alg == Z_EROFS_COMPRESSION_DEFLATE)
178 return z_erofs_decompress_deflate(rq);
179 #endif
180 return -EOPNOTSUPP;
181 }
182