1 // SPDX-License-Identifier: GPL-2.0
2 #ifdef STATIC
3 #define PREBOOT
4 /* Pre-boot environment: included */
5
6 /* prevent inclusion of _LINUX_KERNEL_H in pre-boot environment: lots
7 * errors about console_printk etc... on ARM */
8 #define _LINUX_KERNEL_H
9
10 #include "zlib_inflate/inftrees.c"
11 #include "zlib_inflate/inffast.c"
12 #include "zlib_inflate/inflate.c"
13 #ifdef CONFIG_ZLIB_DFLTCC
14 #include "zlib_dfltcc/dfltcc.c"
15 #include "zlib_dfltcc/dfltcc_inflate.c"
16 #endif
17
18 #else /* STATIC */
19 /* initramfs et al: linked */
20
21 #include <linux/zutil.h>
22
23 #include "zlib_inflate/inftrees.h"
24 #include "zlib_inflate/inffast.h"
25 #include "zlib_inflate/inflate.h"
26
27 #include "zlib_inflate/infutil.h"
28 #include <linux/decompress/inflate.h>
29
30 #endif /* STATIC */
31
32 #include <linux/decompress/mm.h>
33
34 #define GZIP_IOBUF_SIZE (16*1024)
35
36 static long INIT nofill(void *buffer, unsigned long len)
37 {
38 return -1;
39 }
40
41 /* Included from initramfs et al code */
42 static int INIT __gunzip(unsigned char *buf, long len,
43 long (*fill)(void*, unsigned long),
44 long (*flush)(void*, unsigned long),
45 unsigned char *out_buf, long out_len,
46 long *pos,
47 void(*error)(char *x)) {
48 u8 *zbuf;
49 struct z_stream_s *strm;
50 int rc;
51
52 rc = -1;
53 if (flush) {
54 out_len = 0x8000; /* 32 K */
55 out_buf = malloc(out_len);
56 } else {
57 if (!out_len)
58 out_len = ((size_t)~0) - (size_t)out_buf; /* no limit */
59 }
60 if (!out_buf) {
61 error("Out of memory while allocating output buffer");
62 goto gunzip_nomem1;
63 }
64
65 if (buf)
66 zbuf = buf;
67 else {
68 zbuf = malloc(GZIP_IOBUF_SIZE);
69 len = 0;
70 }
71 if (!zbuf) {
72 error("Out of memory while allocating input buffer");
73 goto gunzip_nomem2;
74 }
75
76 strm = malloc(sizeof(*strm));
77 if (strm == NULL) {
78 error("Out of memory while allocating z_stream");
79 goto gunzip_nomem3;
80 }
81
82 strm->workspace = malloc(flush ? zlib_inflate_workspacesize() :
83 #ifdef CONFIG_ZLIB_DFLTCC
84 /* Always allocate the full workspace for DFLTCC */
85 zlib_inflate_workspacesize());
86 #else
87 sizeof(struct inflate_state));
88 #endif
89 if (strm->workspace == NULL) {
90 error("Out of memory while allocating workspace");
91 goto gunzip_nomem4;
92 }
93
94 if (!fill)
95 fill = nofill;
96
97 if (len == 0)
98 len = fill(zbuf, GZIP_IOBUF_SIZE);
99
100 /* verify the gzip header */
101 if (len < 10 ||
102 zbuf[0] != 0x1f || zbuf[1] != 0x8b || zbuf[2] != 0x08) {
103 if (pos)
104 *pos = 0;
105 error("Not a gzip file");
106 goto gunzip_5;
107 }
108
109 /* skip over gzip header (1f,8b,08... 10 bytes total +
110 * possible asciz filename)
111 */
112 strm->next_in = zbuf + 10;
113 strm->avail_in = len - 10;
114 /* skip over asciz filename */
115 if (zbuf[3] & 0x8) {
116 do {
117 /*
118 * If the filename doesn't fit into the buffer,
119 * the file is very probably corrupt. Don't try
120 * to read more data.
121 */
122 if (strm->avail_in == 0) {
123 error("header error");
124 goto gunzip_5;
125 }
126 --strm->avail_in;
127 } while (*strm->next_in++);
128 }
129
130 strm->next_out = out_buf;
131 strm->avail_out = out_len;
132
133 rc = zlib_inflateInit2(strm, -MAX_WBITS);
134
135 #ifdef CONFIG_ZLIB_DFLTCC
136 /* Always keep the window for DFLTCC */
137 #else
138 if (!flush) {
139 WS(strm)->inflate_state.wsize = 0;
140 WS(strm)->inflate_state.window = NULL;
141 }
142 #endif
143
144 while (rc == Z_OK) {
145 if (strm->avail_in == 0) {
146 /* TODO: handle case where both pos and fill are set */
147 len = fill(zbuf, GZIP_IOBUF_SIZE);
148 if (len < 0) {
149 rc = -1;
150 error("read error");
151 break;
152 }
153 strm->next_in = zbuf;
154 strm->avail_in = len;
155 }
156 rc = zlib_inflate(strm, 0);
157
158 /* Write any data generated */
159 if (flush && strm->next_out > out_buf) {
160 long l = strm->next_out - out_buf;
161 if (l != flush(out_buf, l)) {
162 rc = -1;
163 error("write error");
164 break;
165 }
166 strm->next_out = out_buf;
167 strm->avail_out = out_len;
168 }
169
170 /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
171 if (rc == Z_STREAM_END) {
172 rc = 0;
173 break;
174 } else if (rc != Z_OK) {
175 error("uncompression error");
176 rc = -1;
177 }
178 }
179
180 zlib_inflateEnd(strm);
181 if (pos)
182 /* add + 8 to skip over trailer */
183 *pos = strm->next_in - zbuf+8;
184
185 gunzip_5:
186 free(strm->workspace);
187 gunzip_nomem4:
188 free(strm);
189 gunzip_nomem3:
190 if (!buf)
191 free(zbuf);
192 gunzip_nomem2:
193 if (flush)
194 free(out_buf);
195 gunzip_nomem1:
196 return rc; /* returns Z_OK (0) if successful */
197 }
198
199 #ifndef PREBOOT
200 STATIC int INIT gunzip(unsigned char *buf, long len,
201 long (*fill)(void*, unsigned long),
202 long (*flush)(void*, unsigned long),
203 unsigned char *out_buf,
204 long *pos,
205 void (*error)(char *x))
206 {
207 return __gunzip(buf, len, fill, flush, out_buf, 0, pos, error);
208 }
209 #else
210 STATIC int INIT __decompress(unsigned char *buf, long len,
211 long (*fill)(void*, unsigned long),
212 long (*flush)(void*, unsigned long),
213 unsigned char *out_buf, long out_len,
214 long *pos,
215 void (*error)(char *x))
216 {
217 return __gunzip(buf, len, fill, flush, out_buf, out_len, pos, error);
218 }
219 #endif
220
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