/*

 * Copyright (c) 2000, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package com.sun.rmi.rmid;

import java.security.*;

import java.io.*;

import java.util.*;

/**

 * The ExecPermission class represents permission for rmid to execute

 * a specific command to launch an activation group.  An ExecPermission

 * consists of a pathname of a command to launch an activation group.

 * <P>

 * Pathname is the pathname of the file or directory to grant rmid

 * execute permission.  A pathname that ends in "/*" (where "/" is

 * the file separator character, <code>File.separatorChar</code>) indicates

 * all the files and directories contained in that directory. A pathname

 * that ends with "/-" indicates (recursively) all files

 * and subdirectories contained in that directory. A pathname consisting of

 * the special token "&lt;&lt;ALL FILES&gt;&gt;" matches <bold>any</bold> file.

 * <P>

 * Note: A pathname consisting of a single "*" indicates all the files

 * in the current directory, while a pathname consisting of a single "-"

 * indicates all the files in the current directory and

 * (recursively) all files and subdirectories contained in the current

 * directory.

 * <P>

 *

 *

 * @author Ann Wollrath

 *

 * @serial exclude

 */

public final class ExecPermission extends Permission

{

    /**

     * UID for serialization

     */

    private static final long serialVersionUID = -6208470287358147919L;

    private transient FilePermission fp;

    /**

     * Creates a new ExecPermission object with the specified path.

     * <i>path</i> is the pathname of a file or directory.

     *

     * <p>A pathname that ends in "/*" (where "/" is

     * the file separator character, <code>File.separatorChar</code>) indicates

     * a directory and all the files contained in that directory. A pathname

     * that ends with "/-" indicates a directory and (recursively) all files

     * and subdirectories contained in that directory. The special pathname

     * "<<ALL FILES>>" matches all files.

     *

     * <p>A pathname consisting of a single "*" indicates all the files

     * in the current directory, while a pathname consisting of a single "-"

     * indicates all the files in the current directory and

     * (recursively) all files and subdirectories contained in the current

     * directory.

     *

     * @param path the pathname of the file/directory.

     */

    public ExecPermission(String path) {

        super(path);

        init(path);

    }

    /**

     * Creates a new ExecPermission object with the specified path.

     * <i>path</i> is the pathname of a file or directory.

     *

     * <p>A pathname that ends in "/*" (where "/" is

     * the file separator character, <code>File.separatorChar</code>) indicates

     * a directory and all the files contained in that directory. A pathname

     * that ends with "/-" indicates a directory and (recursively) all files

     * and subdirectories contained in that directory. The special pathname

     * "<<ALL FILES>>" matches all files.

     *

     * <p>A pathname consisting of a single "*" indicates all the files

     * in the current directory, while a pathname consisting of a single "-"

     * indicates all the files in the current directory and

     * (recursively) all files and subdirectories contained in the current

     * directory.

     *

     * @param path the pathname of the file/directory.

     * @param actions the action string (unused)

     */

    public ExecPermission(String path, String actions) {

        this(path);

    }

    /**

     * Checks if this ExecPermission object "implies" the specified permission.

     * <P>

     * More specifically, this method returns true if:<p>

     * <ul>

     * <li> <i>p</i> is an instanceof ExecPermission,<p> and

     * <li> <i>p</i>'s pathname is implied by this object's

     *      pathname. For example, "/tmp/*" implies "/tmp/foo", since

     *      "/tmp/*" encompasses the "/tmp" directory and all files in that

     *      directory, including the one named "foo".

     * </ul>

     * @param p the permission to check against.

     *

     * @return true if the specified permission is implied by this object,

     * false if not.

     */

    public boolean implies(Permission p) {

        if (!(p instanceof ExecPermission))

            return false;

        ExecPermission that = (ExecPermission) p;

        return fp.implies(that.fp);

    }

    /**

     * Checks two ExecPermission objects for equality.

     * Checks that <i>obj</i>'s class is the same as this object's class

     * and has the same name as this object.

     * <P>

     * @param obj the object we are testing for equality with this object.

     * @return true if <i>obj</i> is an ExecPermission, and has the same

     * pathname as this ExecPermission object, false otherwise.

     */

    public boolean equals(Object obj) {

        if (obj == this)

            return true;

        if (! (obj instanceof ExecPermission))

            return false;

        ExecPermission that = (ExecPermission) obj;

        return fp.equals(that.fp);

    }

    /**

     * Returns the hash code value for this object.

     *

     * @return a hash code value for this object.

     */

    public int hashCode() {

        return this.fp.hashCode();

    }

    /**

     * Returns the canonical string representation of the actions.

     *

     * @return the canonical string representation of the actions.

     */

    public String getActions() {

        return "";

    }

    /**

     * Returns a new PermissionCollection object for storing

     * ExecPermission objects.

     * <p>

     * A ExecPermissionCollection stores a collection of

     * ExecPermission permissions.

     *

     * <p>ExecPermission objects must be stored in a manner that allows

     * them to be inserted in any order, but that also enables the

     * PermissionCollection <code>implies</code> method

     * to be implemented in an efficient (and consistent) manner.

     *

     * @return a new PermissionCollection object suitable for

     * storing ExecPermissions.

     */

    public PermissionCollection newPermissionCollection() {

        return new ExecPermissionCollection();

    }

    /**

     * readObject is called to restore the state of the ExecPermission

     * from a stream.

     */

    private synchronized void readObject(java.io.ObjectInputStream s)

         throws IOException, ClassNotFoundException

    {

        s.defaultReadObject();

        // init is called to initialize the rest of the values.

        init(getName());

    }

    /**

     * Initialize a ExecPermission object. Common to all constructors.

     * Also called during de-serialization.

     */

    private void init(String path) {

        this.fp = new FilePermission(path, "execute");

    }

    /**

     * A ExecPermissionCollection stores a collection

     * of ExecPermission permissions. ExecPermission objects

     * must be stored in a manner that allows them to be inserted in any

     * order, but enable the implies function to evaluate the implies

     * method in an efficient (and consistent) manner.

     *

     * @serial include

     */

    private static class ExecPermissionCollection

        extends PermissionCollection

        implements java.io.Serializable

    {

        private Vector permissions;

        private static final long serialVersionUID = -3352558508888368273L;

        /**

         * Create an empty ExecPermissionCollection.

         */

        public ExecPermissionCollection() {

            permissions = new Vector();

        }

        /**

         * Adds a permission to the collection.

         *

         * @param permission the Permission object to add.

         *

         * @exception IllegalArgumentException - if the permission is not a

         *                                       ExecPermission

         *

         * @exception SecurityException - if this ExecPermissionCollection

         *                                object has been marked readonly

         */

        public void add(Permission permission)

        {

            if (! (permission instanceof ExecPermission))

                throw new IllegalArgumentException("invalid permission: "+

                                                   permission);

            if (isReadOnly())

                throw new SecurityException("attempt to add a Permission to a readonly PermissionCollection");

            permissions.addElement(permission);

        }

        /**

         * Check and see if this set of permissions implies the permissions

         * expressed in "permission".

         *

         * @param p the Permission object to compare

         *

         * @return true if "permission" is a proper subset of a permission in

         * the set, false if not.

         */

        public boolean implies(Permission permission)

        {

            if (! (permission instanceof ExecPermission))

                return false;

            Enumeration e = permissions.elements();

            while (e.hasMoreElements()) {

                ExecPermission x = (ExecPermission) e.nextElement();

                if (x.implies(permission)) {

                    return true;

                }

            }

            return false;

        }

        /**

         * Returns an enumeration of all the ExecPermission objects in the

         * container.

         *

         * @return an enumeration of all the ExecPermission objects.

         */

        public Enumeration elements()

        {

            return permissions.elements();

        }

    }

}