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d4faaecb DM |
1 | #include <linux/zutil.h> |
2 | #include <linux/errno.h> | |
3 | #include <linux/slab.h> | |
4 | #include <linux/vmalloc.h> | |
5 | ||
6 | /* Utility function: initialize zlib, unpack binary blob, clean up zlib, | |
7 | * return len or negative error code. | |
8 | */ | |
9 | int zlib_inflate_blob(void *gunzip_buf, unsigned int sz, | |
10 | const void *buf, unsigned int len) | |
11 | { | |
12 | const u8 *zbuf = buf; | |
13 | struct z_stream_s *strm; | |
14 | int rc; | |
15 | ||
16 | rc = -ENOMEM; | |
17 | strm = kmalloc(sizeof(*strm), GFP_KERNEL); | |
18 | if (strm == NULL) | |
19 | goto gunzip_nomem1; | |
20 | strm->workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); | |
21 | if (strm->workspace == NULL) | |
22 | goto gunzip_nomem2; | |
23 | ||
24 | /* gzip header (1f,8b,08... 10 bytes total + possible asciz filename) | |
25 | * expected to be stripped from input | |
26 | */ | |
27 | strm->next_in = zbuf; | |
28 | strm->avail_in = len; | |
29 | strm->next_out = gunzip_buf; | |
30 | strm->avail_out = sz; | |
31 | ||
32 | rc = zlib_inflateInit2(strm, -MAX_WBITS); | |
33 | if (rc == Z_OK) { | |
34 | rc = zlib_inflate(strm, Z_FINISH); | |
35 | /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */ | |
36 | if (rc == Z_STREAM_END) | |
37 | rc = sz - strm->avail_out; | |
38 | else | |
39 | rc = -EINVAL; | |
40 | zlib_inflateEnd(strm); | |
41 | } else | |
42 | rc = -EINVAL; | |
43 | ||
44 | kfree(strm->workspace); | |
45 | gunzip_nomem2: | |
46 | kfree(strm); | |
47 | gunzip_nomem1: | |
48 | return rc; /* returns Z_OK (0) if successful */ | |
49 | } |