Check for strlcat and strlcpy

This partially reverts commit 8005ca4 by moving the strlcat()
and strlcpy() compatibility implementations back to their original
location.

In addition, these two functions were added to the AC_CHECK_FUNCS
macro. When these functions are available from the C library,
HAVE_STRLCAT and HAVE_STRLCPY will be defined and library version
used. Otherwise the compatibility version is built.

Reviewed-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8157 
Closes #8202

config/user.m4

@@ -21,7 +21,7 @@ AC_DEFUN([ZFS_AC_CONFIG_USER], [
 
 	ZFS_AC_TEST_FRAMEWORK
 
-	AC_CHECK_FUNCS([mlockall])
+	AC_CHECK_FUNCS([mlockall strlcat strlcpy])
 ])
 
 dnl #

lib/libspl/Makefile.am

@@ -22,6 +22,8 @@ USER_C = \
 	list.c \
 	mkdirp.c \
 	page.c \
+	strlcat.c \
+	strlcpy.c \
 	timestamp.c \
 	zone.c \
 	include/sys/list.h \

lib/libspl/include/string.h

@@ -28,56 +28,13 @@
 #define	_LIBSPL_STRING_H
 
 #include_next <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.
- */
-static inline 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;
+#ifndef HAVE_STRLCAT
+extern size_t strlcat(char *dst, const char *src, size_t dstsize);
+#endif
 
-	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);
-}
-
-/*
- * Copies src to the dstsize buffer at dst. The copy will never
- * overflow the destination buffer and the buffer will always be null
- * terminated.
- */
-static inline size_t
-strlcpy(char *dst, const char *src, size_t len)
-{
-	size_t slen = strlen(src);
-
-	if (len == 0)
-		return (slen);
-
-	size_t copied = (slen >= len) ? len - 1 : slen;
-	(void) memcpy(dst, src, copied);
-	dst[copied] = '\0';
-
-	return (slen);
-}
+#ifndef HAVE_STRLCPY
+extern size_t strlcpy(char *dst, const char *src, size_t len);
+#endif
 
 #endif

lib/libspl/strlcat.c

@@ -0,0 +1,60 @@
+/*
+ * 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.
+ */
+#ifndef HAVE_STRLCAT
+
+#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);
+}
+
+#endif

lib/libspl/strlcpy.c

@@ -0,0 +1,56 @@
+/*
+ * 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.
+ */
+
+#ifndef HAVE_STRLCPY
+
+#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);
+}
+
+#endif /* HAVE_STRLCPY */

tests/zfs-tests/cmd/libzfs_input_check/Makefile.am

@@ -10,5 +10,6 @@ pkgexec_PROGRAMS = libzfs_input_check
 
 libzfs_input_check_SOURCES = libzfs_input_check.c
 libzfs_input_check_LDADD = \
+	$(top_builddir)/lib/libspl/libspl.la \
 	$(top_builddir)/lib/libnvpair/libnvpair.la \
 	$(top_builddir)/lib/libzfs_core/libzfs_core.la