1 files changed, 74 insertions, 0 deletions
diff --git a/sys/cddl/boot/zfs/lzjb.c b/sys/cddl/boot/zfs/lzjb.c
new file mode 100644
index 000000000000..1283a6c31a4b
--- /dev/null
+++ b/sys/cddl/boot/zfs/lzjb.c
@@ -0,0 +1,74 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*#pragma ident	"%Z%%M%	%I%	%E% SMI"*/
+
+/*
+ * We keep our own copy of this algorithm for 2 main reasons:
+ * 	1. If we didn't, anyone modifying common/os/compress.c would
+ *         directly break our on disk format
+ * 	2. Our version of lzjb does not have a number of checks that the
+ *         common/os version needs and uses
+ * In particular, we are adding the "feature" that compress() can
+ * take a destination buffer size and return -1 if the data will not
+ * compress to d_len or less.
+ */
+
+#define	MATCH_BITS	6
+#define	MATCH_MIN	3
+#define	MATCH_MAX	((1 << MATCH_BITS) + (MATCH_MIN - 1))
+#define	OFFSET_MASK	((1 << (16 - MATCH_BITS)) - 1)
+#define	LEMPEL_SIZE	256
+
+/*ARGSUSED*/
+static int
+lzjb_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
+{
+	unsigned char *src = s_start;
+	unsigned char *dst = d_start;
+	unsigned char *d_end = (unsigned char *)d_start + d_len;
+	unsigned char *cpy, copymap = 0;
+	int copymask = 1 << (NBBY - 1);
+
+	while (dst < d_end) {
+		if ((copymask <<= 1) == (1 << NBBY)) {
+			copymask = 1;
+			copymap = *src++;
+		}
+		if (copymap & copymask) {
+			int mlen = (src[0] >> (NBBY - MATCH_BITS)) + MATCH_MIN;
+			int offset = ((src[0] << NBBY) | src[1]) & OFFSET_MASK;
+			src += 2;
+			if ((cpy = dst - offset) < (unsigned char *)d_start)
+				return (-1);
+			while (--mlen >= 0 && dst < d_end)
+				*dst++ = *cpy++;
+		} else {
+			*dst++ = *src++;
+		}
+	}
+	return (0);
+}