lib/zlib_inflate/infutil.c

   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 }