diff --git a/lib/libspl/strlcat.c b/lib/libspl/strlcat.c
new file mode 100644
index 0000000000..b19aa0865d
--- /dev/null
+++ b/lib/libspl/strlcat.c
@@ -0,0 +1,58 @@
+/*
+ * 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 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include <string.h>
+#include <sys/types.h>
+
+/*
+ * Appends src to the dstsize buffer at dst. The append will never
+ * overflow the destination buffer and the buffer will always be null
+ * terminated. Never reference beyond &dst[dstsize-1] when computing
+ * the length of the pre-existing string.
+ */
+
+size_t
+strlcat(char *dst, const char *src, size_t dstsize)
+{
+	char *df = dst;
+	size_t left = dstsize;
+	size_t l1;
+	size_t l2 = strlen(src);
+	size_t copied;
+
+	while (left-- != 0 && *df != '\0')
+		df++;
+	l1 = df - dst;
+	if (dstsize == l1)
+		return (l1 + l2);
+
+	copied = l1 + l2 >= dstsize ? dstsize - l1 - 1 : l2;
+	(void) memcpy(dst + l1, src, copied);
+	dst[l1+copied] = '\0';
+	return (l1 + l2);
+}
diff --git a/lib/libspl/strlcpy.c b/lib/libspl/strlcpy.c
new file mode 100644
index 0000000000..44a6a12e2f
--- /dev/null
+++ b/lib/libspl/strlcpy.c
@@ -0,0 +1,54 @@
+/*
+ * 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 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include <string.h>
+#include <sys/types.h>
+
+/*
+ * Copies src to the dstsize buffer at dst. The copy will never
+ * overflow the destination buffer and the buffer will always be null
+ * terminated.
+ */
+
+size_t
+strlcpy(char *dst, const char *src, size_t len)
+{
+	size_t slen = strlen(src);
+	size_t copied;
+
+	if (len == 0)
+		return (slen);
+
+	if (slen >= len)
+		copied = len - 1;
+	else
+		copied = slen;
+	(void) memcpy(dst, src, copied);
+	dst[copied] = '\0';
+	return (slen);
+}
diff --git a/lib/libspl/strnlen.c b/lib/libspl/strnlen.c
new file mode 100644
index 0000000000..02ce1708c0
--- /dev/null
+++ b/lib/libspl/strnlen.c
@@ -0,0 +1,46 @@
+/*
+ * 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 2008 Sun Microsystems, Inc.
+ * All rights reserved.  Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include <string.h>
+#include <sys/types.h>
+
+/*
+ * Returns the number of non-NULL bytes in string argument,
+ * but not more than maxlen.  Does not look past str + maxlen.
+ */
+size_t
+strnlen(const char *str, size_t maxlen)
+{
+	const char *ptr;
+
+	ptr = memchr(str, 0, maxlen);
+	if (ptr == NULL)
+		return (maxlen);
+
+	return (ptr - str);
+}