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-rw-r--r--lib/zlib_inflate/infutil.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/lib/zlib_inflate/infutil.c b/lib/zlib_inflate/infutil.c
new file mode 100644
index 000000000..4824c2cc7
--- /dev/null
+++ b/lib/zlib_inflate/infutil.c
@@ -0,0 +1,49 @@
+#include <linux/zutil.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+/* Utility function: initialize zlib, unpack binary blob, clean up zlib,
+ * return len or negative error code.
+ */
+int zlib_inflate_blob(void *gunzip_buf, unsigned int sz,
+ const void *buf, unsigned int len)
+{
+ const u8 *zbuf = buf;
+ struct z_stream_s *strm;
+ int rc;
+
+ rc = -ENOMEM;
+ strm = kmalloc(sizeof(*strm), GFP_KERNEL);
+ if (strm == NULL)
+ goto gunzip_nomem1;
+ strm->workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
+ if (strm->workspace == NULL)
+ goto gunzip_nomem2;
+
+ /* gzip header (1f,8b,08... 10 bytes total + possible asciz filename)
+ * expected to be stripped from input
+ */
+ strm->next_in = zbuf;
+ strm->avail_in = len;
+ strm->next_out = gunzip_buf;
+ strm->avail_out = sz;
+
+ rc = zlib_inflateInit2(strm, -MAX_WBITS);
+ if (rc == Z_OK) {
+ rc = zlib_inflate(strm, Z_FINISH);
+ /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
+ if (rc == Z_STREAM_END)
+ rc = sz - strm->avail_out;
+ else
+ rc = -EINVAL;
+ zlib_inflateEnd(strm);
+ } else
+ rc = -EINVAL;
+
+ kfree(strm->workspace);
+gunzip_nomem2:
+ kfree(strm);
+gunzip_nomem1:
+ return rc; /* returns Z_OK (0) if successful */
+}