PSARC 2005/374 Share management improvements

6281048 NFS needs simplified administration

--HG--
rename : usr/src/cmd/dfs.cmds/share/Makefile => deleted_files/usr/src/cmd/dfs.cmds/share/Makefile
rename : usr/src/cmd/dfs.cmds/share/share.c => deleted_files/usr/src/cmd/dfs.cmds/share/share.c
rename : usr/src/cmd/fs.d/nfs/share/share.c => deleted_files/usr/src/cmd/fs.d/nfs/share/share.c
rename : usr/src/cmd/fs.d/nfs/unshare/Makefile => deleted_files/usr/src/cmd/fs.d/nfs/unshare/Makefile
rename : usr/src/cmd/fs.d/nfs/unshare/unshare.c => deleted_files/usr/src/cmd/fs.d/nfs/unshare/unshare.c
rename : usr/src/cmd/fs.d/nfs/share/issubdir.c => usr/src/lib/libshare/common/issubdir.c

1 files changed, 155 insertions, 0 deletions

diff --git a/usr/src/lib/libshare/common/issubdir.c b/usr/src/lib/libshare/common/issubdir.c
new file mode 100644
index 0000000000..d24a4b89e5
--- /dev/null
+++ b/usr/src/lib/libshare/common/issubdir.c
@@ -0,0 +1,155 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (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 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
+/*	  All Rights Reserved  	*/
+
+/*
+ * University Copyright- Copyright (c) 1982, 1986, 1988
+ * The Regents of the University of California
+ * All Rights Reserved
+ *
+ * University Acknowledgment- Portions of this document are derived from
+ * software developed by the University of California, Berkeley, and its
+ * contributors.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+/*
+ * Subdirectory detection: needed by exportfs and rpc.mountd.
+ * The above programs call issubdir() frequently, so we make
+ * it fast by caching the results of stat().
+ */
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <string.h>
+
+#define	MAXSTATS MAXPATHLEN/2	/* maximum number of stat()'s to save */
+
+#define	inoeq(ino1, ino2)	((ino1) == (ino2))
+#define	deveq(dev1, dev2)	((dev1) == (dev2))
+
+/*
+ * dir1 is a subdirectory of dir2 within the same filesystem if
+ *     (a) dir1 is identical to dir2
+ *     (b) dir1's parent is dir2
+ */
+int
+issubdir(dir1, dir2)
+	char *dir1;
+	char *dir2;
+{
+	struct stat st;
+	struct stat parent_st;
+	char *p;
+	int index;
+
+	static dev_t child_dev;
+	static dev_t child_rdev;
+	static ino_t child_ino[MAXSTATS];
+	static int valid;
+	static char childdir[MAXPATHLEN];
+	static char child_fstype[_ST_FSTYPSZ];
+
+	/*
+	 * Get parent directory info
+	 */
+	if (stat(dir2, &parent_st) < 0) {
+		return (0);
+	}
+
+	if (strcmp(childdir, dir1) != 0) {
+		/*
+		 * Not in cache: get child directory info
+		 */
+		p = strcpy(childdir, dir1) + strlen(dir1);
+		index = 0;
+		valid = 0;
+		for (;;) {
+			if (stat(childdir, &st) < 0) {
+				childdir[0] = 0;	/* invalidate cache */
+				return (0);
+			}
+			if (index == 0) {
+				child_dev = st.st_dev;
+				child_rdev = st.st_rdev;
+				(void) strncpy(child_fstype, st.st_fstype,
+						sizeof (child_fstype));
+			}
+			if (index > 0 &&
+			    (child_dev != st.st_dev ||
+				inoeq(child_ino[index - 1], st.st_ino))) {
+				/*
+				 * Hit root: done
+				 */
+				break;
+			}
+			child_ino[index++] = st.st_ino;
+			if (S_ISDIR(st.st_mode)) {
+				p = strcpy(p, "/..") + 3;
+			} else {
+				p = strrchr(childdir, '/');
+				if (p == NULL) {
+					p = strcpy(childdir, ".") + 1;
+				} else {
+					while (((p - 1) > childdir) &&
+						*(p - 1) == '/') {
+						p--;
+					}
+					*p = '\0';
+				}
+			}
+		}
+		valid = index;
+		(void) strcpy(childdir, dir1);
+	}
+
+	/*
+	 * Perform the test
+	 */
+	if (!deveq(parent_st.st_dev, child_dev)) {
+		return (0);
+	}
+
+	/*
+	 * Check rdev also in case of lofs
+	 */
+	if (((strcmp(parent_st.st_fstype, "lofs") == 0)) &&
+		(strcmp(child_fstype, "lofs") == 0)) {
+		if (!deveq(parent_st.st_rdev, child_rdev)) {
+			return (0);
+		}
+	}
+
+	for (index = 0; index < valid; index++) {
+		if (inoeq(child_ino[index], parent_st.st_ino)) {
+			return (1);
+		}
+	}
+	return (0);
+}