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 } 50