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(size: sizeof(*strm), GFP_KERNEL); |
18 | if (strm == NULL) |
19 | goto gunzip_nomem1; |
20 | strm->workspace = kmalloc(size: 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, windowBits: -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(objp: strm->workspace); |
45 | gunzip_nomem2: |
46 | kfree(objp: strm); |
47 | gunzip_nomem1: |
48 | return rc; /* returns Z_OK (0) if successful */ |
49 | } |
50 | |