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