| 1 | #include <linux/zutil.h> |
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| 2 | #include <linux/errno.h> |
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| 3 | #include <linux/slab.h> |
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| 4 | #include <linux/vmalloc.h> |
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| 5 | |
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| 6 | /* Utility function: initialize zlib, unpack binary blob, clean up zlib, |
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| 7 | * return len or negative error code. |
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| 8 | */ |
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| 9 | int zlib_inflate_blob(void *gunzip_buf, unsigned int sz, |
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| 10 | const void *buf, unsigned int len) |
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| 11 | { |
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| 12 | const u8 *zbuf = buf; |
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| 13 | struct z_stream_s *strm; |
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| 14 | int rc; |
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| 15 | |
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| 16 | rc = -ENOMEM; |
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| 17 | strm = kmalloc(size: sizeof(*strm), GFP_KERNEL); |
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| 18 | if (strm == NULL) |
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| 19 | goto gunzip_nomem1; |
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| 20 | strm->workspace = kmalloc(size: zlib_inflate_workspacesize(), GFP_KERNEL); |
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| 21 | if (strm->workspace == NULL) |
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| 22 | goto gunzip_nomem2; |
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| 23 | |
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| 24 | /* gzip header (1f,8b,08... 10 bytes total + possible asciz filename) |
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| 25 | * expected to be stripped from input |
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| 26 | */ |
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| 27 | strm->next_in = zbuf; |
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| 28 | strm->avail_in = len; |
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| 29 | strm->next_out = gunzip_buf; |
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| 30 | strm->avail_out = sz; |
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| 31 | |
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| 32 | rc = zlib_inflateInit2(strm, windowBits: -MAX_WBITS); |
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| 33 | if (rc == Z_OK) { |
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| 34 | rc = zlib_inflate(strm, Z_FINISH); |
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| 35 | /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */ |
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| 36 | if (rc == Z_STREAM_END) |
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| 37 | rc = sz - strm->avail_out; |
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| 38 | else |
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| 39 | rc = -EINVAL; |
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| 40 | zlib_inflateEnd(strm); |
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| 41 | } else |
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| 42 | rc = -EINVAL; |
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| 43 | |
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| 44 | kfree(objp: strm->workspace); |
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| 45 | gunzip_nomem2: |
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| 46 | kfree(objp: strm); |
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| 47 | gunzip_nomem1: |
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| 48 | return rc; /* returns Z_OK (0) if successful */ |
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| 49 | } |
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| 50 | |
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