Line data    Source code

       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           0 : int zlib_inflate_blob(void *gunzip_buf, unsigned int sz,
      10             :                       const void *buf, unsigned int len)
      11             : {
      12           0 :         const u8 *zbuf = buf;
      13           0 :         struct z_stream_s *strm;
      14           0 :         int rc;
      15             : 
      16           0 :         rc = -ENOMEM;
      17           0 :         strm = kmalloc(sizeof(*strm), GFP_KERNEL);
      18           0 :         if (strm == NULL)
      19           0 :                 goto gunzip_nomem1;
      20           0 :         strm->workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
      21           0 :         if (strm->workspace == NULL)
      22           0 :                 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           0 :         strm->next_in = zbuf;
      28           0 :         strm->avail_in = len;
      29           0 :         strm->next_out = gunzip_buf;
      30           0 :         strm->avail_out = sz;
      31             : 
      32           0 :         rc = zlib_inflateInit2(strm, -MAX_WBITS);
      33           0 :         if (rc == Z_OK) {
      34           0 :                 rc = zlib_inflate(strm, Z_FINISH);
      35             :                 /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
      36           0 :                 if (rc == Z_STREAM_END)
      37           0 :                         rc = sz - strm->avail_out;
      38             :                 else
      39             :                         rc = -EINVAL;
      40           0 :                 zlib_inflateEnd(strm);
      41             :         } else
      42             :                 rc = -EINVAL;
      43             : 
      44           0 :         kfree(strm->workspace);
      45           0 : gunzip_nomem2:
      46           0 :         kfree(strm);
      47           0 : gunzip_nomem1:
      48           0 :         return rc; /* returns Z_OK (0) if successful */
      49             : }