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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
e7d163f7 | 2 | #include <linux/zlib.h> |
4bedea94 CZ |
3 | |
4 | /* bits taken from ppc */ | |
5 | ||
6 | extern void *avail_ram, *end_avail; | |
f54d02c8 | 7 | void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp); |
4bedea94 | 8 | |
f54d02c8 | 9 | static void exit(void) |
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10 | { |
11 | for (;;); | |
12 | } | |
13 | ||
f54d02c8 | 14 | static void *zalloc(unsigned int size) |
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15 | { |
16 | void *p = avail_ram; | |
17 | ||
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18 | size = (size + 7) & -8; |
19 | avail_ram += size; | |
20 | if (avail_ram > end_avail) { | |
21 | //puts("oops... out of memory\n"); | |
22 | //pause(); | |
23 | exit (); | |
24 | } | |
25 | return p; | |
26 | } | |
27 | ||
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28 | #define HEAD_CRC 2 |
29 | #define EXTRA_FIELD 4 | |
30 | #define ORIG_NAME 8 | |
31 | #define COMMENT 0x10 | |
32 | #define RESERVED 0xe0 | |
33 | ||
34 | #define DEFLATED 8 | |
35 | ||
36 | void gunzip (void *dst, int dstlen, unsigned char *src, int *lenp) | |
37 | { | |
38 | z_stream s; | |
39 | int r, i, flags; | |
40 | ||
41 | /* skip header */ | |
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42 | i = 10; |
43 | flags = src[3]; | |
44 | if (src[2] != DEFLATED || (flags & RESERVED) != 0) { | |
45 | //puts("bad gzipped data\n"); | |
46 | exit(); | |
47 | } | |
48 | if ((flags & EXTRA_FIELD) != 0) | |
49 | i = 12 + src[10] + (src[11] << 8); | |
50 | if ((flags & ORIG_NAME) != 0) | |
51 | while (src[i++] != 0) | |
52 | ; | |
53 | if ((flags & COMMENT) != 0) | |
54 | while (src[i++] != 0) | |
55 | ; | |
56 | if ((flags & HEAD_CRC) != 0) | |
57 | i += 2; | |
58 | if (i >= *lenp) { | |
59 | //puts("gunzip: ran out of data in header\n"); | |
60 | exit(); | |
61 | } | |
62 | ||
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63 | s.workspace = zalloc(zlib_inflate_workspacesize()); |
64 | r = zlib_inflateInit2(&s, -MAX_WBITS); | |
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65 | if (r != Z_OK) { |
66 | //puts("inflateInit2 returned "); puthex(r); puts("\n"); | |
67 | exit(); | |
68 | } | |
69 | s.next_in = src + i; | |
70 | s.avail_in = *lenp - i; | |
71 | s.next_out = dst; | |
72 | s.avail_out = dstlen; | |
e7d163f7 | 73 | r = zlib_inflate(&s, Z_FINISH); |
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74 | if (r != Z_OK && r != Z_STREAM_END) { |
75 | //puts("inflate returned "); puthex(r); puts("\n"); | |
76 | exit(); | |
77 | } | |
78 | *lenp = s.next_out - (unsigned char *) dst; | |
e7d163f7 | 79 | zlib_inflateEnd(&s); |
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80 | } |
81 |