server/ACL/ACL.java

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

//---IMPORTS---
import uk.org.iscream.cms.server.util.*;
import java.util.ArrayList;
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) {
        for(int i=0; i < _acl.size(); i++) {
            ACLRule rule = (ACLRule) _acl.get(i);
            if(StringUtils.wildcardCheck(address, rule._expression)) {
                return rule._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) {
        for(int i=0; i < _acl.size(); i++) {
            ACLRule rule = (ACLRule) _acl.get(i);
            if(StringUtils.wildcardCheck(address.getHostName(), rule._expression)) {
                return rule._allow;
            }
            if(StringUtils.wildcardCheck(address.getHostAddress(), rule._expression)) {
                return rule._allow;
            }
        }
        return _defaultMode;
    }
    
    /**
     * Gets the ACL as a String for debugging.
     *
     * @return A String representation of this ACL.
     */
    public String getStringACL() {
        String acl = "";
        for(int i=0; i < _acl.size(); i++) {
            ACLRule rule = (ACLRule) _acl.get(i);
            if(rule._allow) {
                acl += "ALLOW:" + rule._expression + " ";
            }
            else {
                acl += "DENY:" + rule._expression + " ";
            }
        }
        if(_defaultMode) {
            acl += "DEFAULT:ALLOW";
        }
        else {
            acl += "DEFAULT:DENY";
        }
        return acl;
    }
    
    /**
     * 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 ArrayList.
     */
    private ArrayList _acl = new ArrayList();
    
    /**
     * 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:	1.3
Committed:	Fri Dec 21 16:49:18 2001 UTC (22 years, 11 months ago) by tdb
Branch:	MAIN
Changes since 1.2:	+25 -25 lines
Log Message:	Changed the LinkedList/Iterator to an ArrayList.get(n) solution. According to Paul's research this should run at least 4 times as fast as the LinkedList in the iterating stage. (and twice as quick as an ArrayList/Iterator solution!). Using a plain array could make this go twice as fast again, but it's a lot more work :-)
#	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	tdb	1.3	import java.util.ArrayList;
7	tdb	1.1	import java.net.InetAddress;
8
9			/**
10	tdb	1.2	* Access Control List for use primarily
11			* with the ACLServerSocket. It could, however
12			* have other uses as it has a fairly generic
13			* behaviour. Rules are added using the add
14			* method, and then checks can be made using
15			* the relevant check method.
16	tdb	1.1	*
17			* @author $Author$
18			* @version $Id$
19			*/
20			public class ACL {
21
22			//---FINAL ATTRIBUTES---
23
24			/**
25			* The current CVS revision of this class
26			*/
27			public static final String REVISION = "$Revision$";
28	tdb	1.2
29			/**
30			* static to be used when adding an ALLOW rule to the ACL.
31			*/
32	tdb	1.1	public static final boolean ALLOW = true;
33	tdb	1.2
34			/**
35			* static to be used when adding a DENY rule to the ACL.
36			*/
37	tdb	1.1	public static final boolean DENY = false;
38
39			//---STATIC METHODS---
40
41			//---CONSTRUCTORS---
42
43	tdb	1.2	/**
44			* Construct a new Access Control List. The default
45			* mode is to ALLOW anything that isn't explicitly
46			* blocked by a rule.
47			*/
48	tdb	1.1	public ACL() {
49			// default to ACL.ALLOW
50			this(ACL.ALLOW);
51			}
52
53	tdb	1.2	/**
54			* Construct a new Access Control List with a given
55			* default mode. This mode specifies what should
56			* happen if a check does not match any rules.
57			*
58			* @param defaultMode the default mode for non-matched checks
59			*/
60	tdb	1.1	public ACL(boolean defaultMode) {
61			_defaultMode = defaultMode;
62			}
63
64			//---PUBLIC METHODS---
65
66	tdb	1.2	/**
67			* Add a new rule to the ACL immediately after the
68			* previous rule. The rule can either be an ACL.ALLOW
69			* rule, or an ACL.DENY rule. The expression can
70			* contain a wildcard (a * only). Rules can only be
71			* added to the end of the list.
72			*
73			* param allow whether this is an ALLOW or DENY rule
74			* param expression what this rule matches using wildcards
75			*/
76	tdb	1.1	public void add(boolean allow, String expression) {
77	tdb	1.2	_acl.add(new ACLRule(allow, expression));
78	tdb	1.1	}
79
80	tdb	1.2	/**
81			* Check to see if a string is permitted by the
82			* ACL. Useful for testing, and non-Socket uses
83			* of this class.
84			*
85			* @param address the string to check
86			* @return whether the address was permitted by the ACL
87			*/
88	tdb	1.1	public boolean check(String address) {
89	tdb	1.3	for(int i=0; i < _acl.size(); i++) {
90			ACLRule rule = (ACLRule) _acl.get(i);
91			if(StringUtils.wildcardCheck(address, rule._expression)) {
92			return rule._allow;
93	tdb	1.1	}
94			}
95			return _defaultMode;
96			}
97
98	tdb	1.2	/**
99			* Check to see if an InetAddress is permitted
100			* by the ACL. Perfect for Socket uses of this
101			* class. It should be made clear that this will
102			* check both the hostname AND IP address against
103			* each rule in turn. The hostname will always be
104			* checked BEFORE the IP address.
105			*
106			* @param address the InetAddress to check
107			* @return whether the InetAddress was permitted by the ACL
108			*/
109	tdb	1.1	public boolean check(InetAddress address) {
110	tdb	1.3	for(int i=0; i < _acl.size(); i++) {
111			ACLRule rule = (ACLRule) _acl.get(i);
112			if(StringUtils.wildcardCheck(address.getHostName(), rule._expression)) {
113			return rule._allow;
114	tdb	1.1	}
115	tdb	1.3	if(StringUtils.wildcardCheck(address.getHostAddress(), rule._expression)) {
116			return rule._allow;
117	tdb	1.1	}
118			}
119			return _defaultMode;
120			}
121
122	tdb	1.2	/**
123			* Gets the ACL as a String for debugging.
124			*
125			* @return A String representation of this ACL.
126			*/
127			public String getStringACL() {
128	tdb	1.1	String acl = "";
129	tdb	1.3	for(int i=0; i < _acl.size(); i++) {
130			ACLRule rule = (ACLRule) _acl.get(i);
131			if(rule._allow) {
132			acl += "ALLOW:" + rule._expression + " ";
133	tdb	1.1	}
134			else {
135	tdb	1.3	acl += "DENY:" + rule._expression + " ";
136	tdb	1.1	}
137			}
138	tdb	1.3	if(_defaultMode) {
139			acl += "DEFAULT:ALLOW";
140			}
141			else {
142			acl += "DEFAULT:DENY";
143			}
144			return acl;
145	tdb	1.1	}
146
147			/**
148			* Overrides the {@link java.lang.Object#toString() Object.toString()}
149			* method to provide clean logging (every class should have this).
150			*
151			* This uses the uk.org.iscream.cms.server.util.FormatName class
152			* to format the toString()
153			*
154			* @return the name of this class and its CVS revision
155			*/
156			public String toString() {
157			return FormatName.getName(
158			_name,
159			getClass().getName(),
160			REVISION);
161			}
162
163			//---PRIVATE METHODS---
164
165			//---ACCESSOR/MUTATOR METHODS---
166
167			//---ATTRIBUTES---
168
169			/**
170			* This is the friendly identifier of the
171			* component this class is running in.
172			* eg, a Filter may be called "filter1",
173			* If this class does not have an owning
174			* component, a name from the configuration
175			* can be placed here. This name could also
176			* be changed to null for utility classes.
177			*/
178			private String _name = null;
179	tdb	1.2
180			/**
181	tdb	1.3	* The ACL is stored in this ArrayList.
182	tdb	1.2	*/
183	tdb	1.3	private ArrayList _acl = new ArrayList();
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			}