server/ACL/ACL.java

//---PACKAGE DECLARATION---
//package uk.org.iscream.cms.server.util;

//---IMPORTS---
import uk.org.iscream.cms.server.util.*;
import java.util.LinkedList;
import java.util.Iterator;
import java.net.InetAddress;

/**
 * Access Control List for use primarily
 * with the ACLServerSocket. It could, however
 * have other uses as it has a fairly generic
 * behaviour. Rules are added using the add
 * method, and then checks can be made using
 * the relevant check method.
 *
 * @author  $Author$
 * @version $Id$
 */
public class ACL {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision$";
    
    /**
     * static to be used when adding an ALLOW rule to the ACL.
     */
    public static final boolean ALLOW = true;
    
    /**
     * static to be used when adding a DENY rule to the ACL.
     */
    public static final boolean DENY = false;

//---STATIC METHODS---

//---CONSTRUCTORS---

    /**
     * Construct a new Access Control List. The default
     * mode is to ALLOW anything that isn't explicitly
     * blocked by a rule.
     */
    public ACL() {
        // default to ACL.ALLOW
        this(ACL.ALLOW);
    }
    
    /**
     * Construct a new Access Control List with a given
     * default mode. This mode specifies what should
     * happen if a check does not match any rules.
     *
     * @param defaultMode the default mode for non-matched checks
     */
    public ACL(boolean defaultMode) {
        _defaultMode = defaultMode;
    }

//---PUBLIC METHODS---

    /**
     * Add a new rule to the ACL immediately after the
     * previous rule. The rule can either be an ACL.ALLOW
     * rule, or an ACL.DENY rule. The expression can
     * contain a wildcard (a * only). Rules can only be
     * added to the end of the list.
     *
     * param allow whether this is an ALLOW or DENY rule
     * param expression what this rule matches using wildcards
     */
    public void add(boolean allow, String expression) {
        _acl.add(new ACLRule(allow, expression));
    }
    
    /**
     * Check to see if a string is permitted by the
     * ACL. Useful for testing, and non-Socket uses
     * of this class.
     *
     * @param address the string to check
     * @return whether the address was permitted by the ACL
     */
    public boolean check(String address) {
        Iterator i = _acl.iterator();
        while(i.hasNext()) {
            ACLRule item = (ACLRule) i.next();
            if(StringUtils.wildcardCheck(address, item._expression)) {
                return item._allow;
            }
        }
        return _defaultMode;
    }
    
    /**
     * Check to see if an InetAddress is permitted
     * by the ACL. Perfect for Socket uses of this
     * class. It should be made clear that this will
     * check both the hostname AND IP address against
     * each rule in turn. The hostname will always be
     * checked BEFORE the IP address.
     *
     * @param address the InetAddress to check
     * @return whether the InetAddress was permitted by the ACL
     */
    public boolean check(InetAddress address) {
        Iterator i = _acl.iterator();
        while(i.hasNext()) {
            ACLRule item = (ACLRule) i.next();
            if(StringUtils.wildcardCheck(address.getHostName(), item._expression)) {
                return item._allow;
            }
            if(StringUtils.wildcardCheck(address.getHostAddress(), item._expression)) {
                return item._allow;
            }
        }
        return _defaultMode;
    }
    
    /**
     * Gets the ACL as a String for debugging.
     *
     * @return A String representation of this ACL.
     */
    public String getStringACL() {
        String acl = "";
        Iterator i = _acl.iterator();
        while(i.hasNext()) {
            ACLRule item = (ACLRule) i.next();
            if(item._allow) {
                acl += "ALLOW:" + item._expression + " ";
            }
            else {
                acl += "DENY:" + item._expression + " ";
            }
        }
        return acl.substring(0, acl.length()-1);
    }
    
    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.org.iscream.cms.server.util.FormatName class
     * to format the toString()
     *
     * @return the name of this class and its CVS revision
     */
    public String toString() {
        return FormatName.getName(
            _name,
            getClass().getName(),
            REVISION);
    }

//---PRIVATE METHODS---

//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---

    /**
     * This is the friendly identifier of the
     * component this class is running in.
     * eg, a Filter may be called "filter1",
     * If this class does not have an owning
     * component,  a name from the configuration
     * can be placed here.  This name could also
     * be changed to null for utility classes.
     */
    private String _name = null;
    
    /**
     * The ACL is stored in this LinkedList.
     * This is ideal as the list is always searched
     * from beginning to end in an iterative fashion.
     */
    private LinkedList _acl = new LinkedList();
    
    /**
     * The default mode of this ACL.
     */
    private boolean _defaultMode;

//---STATIC ATTRIBUTES---

//---INNER CLASSES---

    /**
     * Wrapper class for an ACL rule.
     */
    private class ACLRule {
        
        /**
         * Construct an ACL rule.
         *
         * @param allow whether this is an ALLOW or DENY rule
         * @param expression what this rule matches
         */
        private ACLRule(boolean allow, String expression) {
            _allow = allow;
            _expression = expression;
        }
        
        /**
         * Whether this is an ALLOW or DENY rule.
         */
        private boolean _allow;
        
        /**
         * What this rule matches.
         */
        private String _expression;
        
    }

}
Revision:	1.2
Committed:	Thu Dec 20 00:59:54 2001 UTC (22 years, 4 months ago) by tdb
Branch:	MAIN
Changes since 1.1:	+93 -14 lines
Log Message:	Fully commented, and further testing in the Socket environment. Probably ready to integrate into the main source tree under the server util package.
#	User	Rev	Content
1	tdb	1.1	//---PACKAGE DECLARATION---
2			//package uk.org.iscream.cms.server.util;
3
4			//---IMPORTS---
5			import uk.org.iscream.cms.server.util.*;
6			import java.util.LinkedList;
7			import java.util.Iterator;
8			import java.net.InetAddress;
9
10			/**
11	tdb	1.2	* Access Control List for use primarily
12			* with the ACLServerSocket. It could, however
13			* have other uses as it has a fairly generic
14			* behaviour. Rules are added using the add
15			* method, and then checks can be made using
16			* the relevant check method.
17	tdb	1.1	*
18			* @author $Author$
19			* @version $Id$
20			*/
21			public class ACL {
22
23			//---FINAL ATTRIBUTES---
24
25			/**
26			* The current CVS revision of this class
27			*/
28			public static final String REVISION = "$Revision$";
29	tdb	1.2
30			/**
31			* static to be used when adding an ALLOW rule to the ACL.
32			*/
33	tdb	1.1	public static final boolean ALLOW = true;
34	tdb	1.2
35			/**
36			* static to be used when adding a DENY rule to the ACL.
37			*/
38	tdb	1.1	public static final boolean DENY = false;
39
40			//---STATIC METHODS---
41
42			//---CONSTRUCTORS---
43
44	tdb	1.2	/**
45			* Construct a new Access Control List. The default
46			* mode is to ALLOW anything that isn't explicitly
47			* blocked by a rule.
48			*/
49	tdb	1.1	public ACL() {
50			// default to ACL.ALLOW
51			this(ACL.ALLOW);
52			}
53
54	tdb	1.2	/**
55			* Construct a new Access Control List with a given
56			* default mode. This mode specifies what should
57			* happen if a check does not match any rules.
58			*
59			* @param defaultMode the default mode for non-matched checks
60			*/
61	tdb	1.1	public ACL(boolean defaultMode) {
62			_defaultMode = defaultMode;
63			}
64
65			//---PUBLIC METHODS---
66
67	tdb	1.2	/**
68			* Add a new rule to the ACL immediately after the
69			* previous rule. The rule can either be an ACL.ALLOW
70			* rule, or an ACL.DENY rule. The expression can
71			* contain a wildcard (a * only). Rules can only be
72			* added to the end of the list.
73			*
74			* param allow whether this is an ALLOW or DENY rule
75			* param expression what this rule matches using wildcards
76			*/
77	tdb	1.1	public void add(boolean allow, String expression) {
78	tdb	1.2	_acl.add(new ACLRule(allow, expression));
79	tdb	1.1	}
80
81	tdb	1.2	/**
82			* Check to see if a string is permitted by the
83			* ACL. Useful for testing, and non-Socket uses
84			* of this class.
85			*
86			* @param address the string to check
87			* @return whether the address was permitted by the ACL
88			*/
89	tdb	1.1	public boolean check(String address) {
90			Iterator i = _acl.iterator();
91			while(i.hasNext()) {
92	tdb	1.2	ACLRule item = (ACLRule) i.next();
93	tdb	1.1	if(StringUtils.wildcardCheck(address, item._expression)) {
94			return item._allow;
95			}
96			}
97			return _defaultMode;
98			}
99
100	tdb	1.2	/**
101			* Check to see if an InetAddress is permitted
102			* by the ACL. Perfect for Socket uses of this
103			* class. It should be made clear that this will
104			* check both the hostname AND IP address against
105			* each rule in turn. The hostname will always be
106			* checked BEFORE the IP address.
107			*
108			* @param address the InetAddress to check
109			* @return whether the InetAddress was permitted by the ACL
110			*/
111	tdb	1.1	public boolean check(InetAddress address) {
112			Iterator i = _acl.iterator();
113			while(i.hasNext()) {
114	tdb	1.2	ACLRule item = (ACLRule) i.next();
115	tdb	1.1	if(StringUtils.wildcardCheck(address.getHostName(), item._expression)) {
116			return item._allow;
117			}
118			if(StringUtils.wildcardCheck(address.getHostAddress(), item._expression)) {
119			return item._allow;
120			}
121			}
122			return _defaultMode;
123			}
124
125	tdb	1.2	/**
126			* Gets the ACL as a String for debugging.
127			*
128			* @return A String representation of this ACL.
129			*/
130			public String getStringACL() {
131	tdb	1.1	String acl = "";
132			Iterator i = _acl.iterator();
133			while(i.hasNext()) {
134	tdb	1.2	ACLRule item = (ACLRule) i.next();
135	tdb	1.1	if(item._allow) {
136			acl += "ALLOW:" + item._expression + " ";
137			}
138			else {
139			acl += "DENY:" + item._expression + " ";
140			}
141			}
142			return acl.substring(0, acl.length()-1);
143			}
144
145			/**
146			* Overrides the {@link java.lang.Object#toString() Object.toString()}
147			* method to provide clean logging (every class should have this).
148			*
149			* This uses the uk.org.iscream.cms.server.util.FormatName class
150			* to format the toString()
151			*
152			* @return the name of this class and its CVS revision
153			*/
154			public String toString() {
155			return FormatName.getName(
156			_name,
157			getClass().getName(),
158			REVISION);
159			}
160
161			//---PRIVATE METHODS---
162
163			//---ACCESSOR/MUTATOR METHODS---
164
165			//---ATTRIBUTES---
166
167			/**
168			* This is the friendly identifier of the
169			* component this class is running in.
170			* eg, a Filter may be called "filter1",
171			* If this class does not have an owning
172			* component, a name from the configuration
173			* can be placed here. This name could also
174			* be changed to null for utility classes.
175			*/
176			private String _name = null;
177	tdb	1.2
178			/**
179			* The ACL is stored in this LinkedList.
180			* This is ideal as the list is always searched
181			* from beginning to end in an iterative fashion.
182			*/
183	tdb	1.1	private LinkedList _acl = new LinkedList();
184	tdb	1.2
185			/**
186			* The default mode of this ACL.
187			*/
188	tdb	1.1	private boolean _defaultMode;
189
190			//---STATIC ATTRIBUTES---
191
192			//---INNER CLASSES---
193
194	tdb	1.2	/**
195			* Wrapper class for an ACL rule.
196			*/
197			private class ACLRule {
198	tdb	1.1
199	tdb	1.2	/**
200			* Construct an ACL rule.
201			*
202			* @param allow whether this is an ALLOW or DENY rule
203			* @param expression what this rule matches
204			*/
205			private ACLRule(boolean allow, String expression) {
206	tdb	1.1	_allow = allow;
207			_expression = expression;
208			}
209
210	tdb	1.2	/**
211			* Whether this is an ALLOW or DENY rule.
212			*/
213	tdb	1.1	private boolean _allow;
214	tdb	1.2
215			/**
216			* What this rule matches.
217			*/
218	tdb	1.1	private String _expression;
219
220			}
221
222			}