1 files changed, 66 insertions, 0 deletions
diff --git a/usr/src/boot/lib/libstand/zfs/gzip.c b/usr/src/boot/lib/libstand/zfs/gzip.c
new file mode 100644
index 0000000000..676d1cb87f
--- /dev/null
+++ b/usr/src/boot/lib/libstand/zfs/gzip.c
@@ -0,0 +1,66 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright 2015 Toomas Soome <tsoome@me.com>
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#include <zlib.h>
+#include <strings.h>
+
+int gzip_decompress(void *, void *, size_t, size_t, int);
+/*
+ * Uncompress the buffer 'src' into the buffer 'dst'.  The caller must store
+ * the expected decompressed data size externally so it can be passed in.
+ * The resulting decompressed size is then returned through dstlen.  This
+ * function return Z_OK on success, or another error code on failure.
+ */
+static int
+z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
+{
+	z_stream zs;
+	int err;
+
+	bzero(&zs, sizeof (zs));
+	zs.next_in = (unsigned char *)src;
+	zs.avail_in = srclen;
+	zs.next_out = dst;
+	zs.avail_out = *dstlen;
+
+	/*
+	 * Call inflateInit2() specifying a window size of DEF_WBITS
+	 * with the 6th bit set to indicate that the compression format
+	 * type (zlib or gzip) should be automatically detected.
+	 */
+	if ((err = inflateInit2(&zs, 15 | 0x20)) != Z_OK)
+		return (err);
+
+	if ((err = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
+		(void) inflateEnd(&zs);
+		return (err == Z_OK ? Z_BUF_ERROR : err);
+	}
+
+	*dstlen = zs.total_out;
+	return (inflateEnd(&zs));
+}
+
+int
+gzip_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
+{
+	size_t dstlen = d_len;
+
+	if (z_uncompress(d_start, &dstlen, s_start, s_len) != Z_OK)
+		return (-1);
+
+	return (0);
+}