cms/util/ACL.java

/* 
 * i-scream central monitoring system
 * Copyright (C) 2000-2002 i-scream
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program 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 for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

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

//---IMPORTS---
import java.util.ArrayList;
import java.util.StringTokenizer;
import java.net.InetAddress;
import java.io.Serializable;

/**
 * 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: tdb $
 * @version $Id: ACL.java,v 1.4 2002/03/20 17:03:35 tdb Exp $
 */
public class ACL implements Serializable {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.4 $";
    
    /**
     * 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;
    
    /**
     * default setting for the default mode for a new ACL.
     */
    public static final boolean DEFMODE = ACL.ALLOW;

//---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 DEFMODE
        this(DEFMODE);
    }
    
    /**
     * 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) {
        setDefaultMode(defaultMode);
    }

    /**
     * Construct a new Access Control List with a given
     * String representation of the ACL rules. The String
     * should be of the format:
     *     expression:rule;expression:rule;expression:rule...
     * Where expression is a wildcard to match against, and
     * rule is either 'ALLOW' or 'DENY'. There is a special
     * expression of 'DEFAULT' which represents the default
     * rule (what should happen if no expression is matched
     * when performing a check).
     * The default mode is set to ALLOW if one is not
     * specified in the String.
     *
     * @param acl a String representation of the ACL.
     */
    public ACL(String acl) {
        setDefaultMode(DEFMODE);
        add(acl);
    }

//---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) {
        // try and convert the expression into an IP address
        short[] ipaddr = ipStringToShort(expression);
        // a result of null means it's not an IP address
        // add either a name rule or an IP rule
        if(ipaddr != null) {
            _acl.add(new ACLRule(allow, expression, ipaddr, true));
        }
        else {
            _acl.add(new ACLRule(allow, expression, ipaddr, false));
        }
    }
    
    /**
     * Add some new rules to the Access Control List in
     * the form of a String. The String should be of the
     * following format:
     *     expression:rule;expression:rule;expression:rule...
     * Where expression is a wildcard to match against, and
     * rule is either 'ALLOW' or 'DENY'. There is a special
     * expression of 'DEFAULT' which represents the default
     * rule (what should happen if no expression is matched
     * when performing a check).
     *
     * @param acl a String representation of the ACL.
     */
    public void add(String acl) {
        if(acl != null) {
            // split the String into expression:rule parts
            StringTokenizer st1 = new StringTokenizer(acl, ";");
            while(st1.hasMoreTokens()) {
                String token1 = st1.nextToken();
                // if it doesn't have a :, it's not the correct format
                if(token1.indexOf(":") != -1) {
                    // split into expression and rule part
                    StringTokenizer st2 = new StringTokenizer(token1, ":");
                    String expression = "";
                    String rule = "";
                    if(st2.hasMoreTokens()) {
                        expression = st2.nextToken();
                    }
                    else {
                        // mall-formed?
                        continue;
                    }
                    if(st2.hasMoreTokens()) {
                        rule = st2.nextToken();
                    }
                    else {
                        // mall-formed?
                        continue;
                    }
                    // check to see what sort of rule
                    if(rule.equals("ALLOW")) {
                        // case for special 'DEFAULT' expression
                        if(expression.equals("DEFAULT")) {
                            setDefaultMode(ACL.ALLOW);
                        }
                        else {
                            add(ACL.ALLOW, expression);
                        }
                    }
                    else if(rule.equals("DENY")) {
                        // case for special 'DEFAULT' expression
                        if(expression.equals("DEFAULT")) {
                            setDefaultMode(ACL.DENY);
                        }
                        else {
                            add(ACL.DENY, expression);
                        }
                    }
                    // if it's not ALLOW or DENY, it's not a
                    // proper rule, so we'll ignore it
                }
            }
        }
    }
    
    /**
     * 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.wildcardMatch(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. A rule will either be for a name, or
     * an IP address (this is determined in the add
     * method), and the appropriate comparison will
     * be performed.
     *
     * @param address the InetAddress to check
     * @return whether the InetAddress was permitted by the ACL
     */
    public boolean check(InetAddress address) {
        // gather the details first
        String hostname = address.getHostName();
        String ip = address.getHostAddress();
        short[] ipaddr = ipStringToShort(ip);
        // check each rule against this InetAddress
        for(int i=0; i < _acl.size(); i++) {
            ACLRule rule = (ACLRule) _acl.get(i);
            if(rule._iprule) {
                // if this is an IP rule do a short comparison
                // must specify the wildcarded rule first
                if(compareShorts(rule._ipaddr, ipaddr)) {
                    return rule._allow;
                }
            }
            else {
                // if not do a full blown String comparsion
                if(StringUtils.wildcardMatch(hostname, rule._expression)) {
                    return rule._allow;
                }
            }
            
        }
        // if we haven't matched a rule, return the default
        return _defaultMode;
    }
    
    /**
     * Clears the ACL and resets the default mode.
     */
    public void clear() {
        // just clear out our underlying ArrayList
        // containing our ACL objects
        _acl.clear();
        // and reset the default mode to the default
        setDefaultMode(DEFMODE);
    }
    
    /**
     * Changes the default mode of the ACL. This is what
     * the check will return if it does not find an explict
     * rule to match against.
     *
     * @param defaultMode the new default mode
     */
    public void setDefaultMode(boolean defaultMode) {
        _defaultMode = defaultMode;
    }
    
    /**
     * Gives a String representation of this ACL.
     *
     * @return A String representation of this ACL.
     */
    public String toString() {
        StringBuffer acl = new StringBuffer();
        // put in the i-scream toString code
        acl.append(FormatName.getName(_name, getClass().getName(), REVISION));
        acl.append("{");
        // put the value of each Rule in the result
        for(int i=0; i < _acl.size(); i++) {
            acl.append((ACLRule) _acl.get(i));
            acl.append(",");
        }
        // put the default mode in the result
        if(_defaultMode) {
            acl.append("DEFAULT=ALLOW");
        }
        else {
            acl.append("DEFAULT=DENY");
        }
        acl.append("}");
        return acl.toString();
    }

//---PRIVATE METHODS---

    /**
     * Converts an IP address in String format into
     * a short array of length 4. Any wildcards, *,
     * found in the IP address are represented by
     * a -1. If the given String is not an IP address
     * null is returned instead.
     * 
     * @param ip The IP address in String format
     * @return The IP address in a short[]
     */
    private short[] ipStringToShort(String ip) {
        // default to expecting it to be an IP
        // we will try to disprove this :)
        short[] ipaddr = {-1, -1, -1, -1};
        int i = 0;
        String s = "";
        // tokenize the String on fullstops, so we can break
        // up the quads of an IP (if it's an IP!)
        StringTokenizer st = new StringTokenizer(ip, ".");
        while(st.hasMoreTokens() && i++ < 4) {
            s = st.nextToken();
            // if it's a wildcard, we'll skip to the next one
            // as no more checks are required
            if(s.equals("*")) {
                continue;
            }
            // attempt to parse it into a short
            try {
                short n = Short.parseShort(s);
                // if it's an int but outside of the
                // valid range, it can't be an IP
                if(n < 0 || n > 255) {
                    // give up checking further
                    return null;
                }
                ipaddr[i-1] = n;
            }
            // if it didn't parse as a short it can't be an IP
            catch (NumberFormatException e) {
                // give up checking further
                return null;
            }
        }
        // we've done 4 parts, so if there's any
        // more this can't be an IP
        if(st.hasMoreTokens()) {
            return null;
        }
        // if we've done less than 4, see if the last one
        // was a wildcard - if it isn't then it's not an IP
        //   -- this allows 129.12.*
        if(i < 4 && !s.equals("*")) {
            return null;
        }
        // if we had one or less entries it can't be an IP
        //   -- this disallows * matching as an IP due
        //      to the rule above
        if(i <= 1) {
            return null;
        }
        return ipaddr;
    }
    
    /**
     * Compares two short arrays. The first array can contain a -1,
     * which will always match any value -- it's a wildcard.
     * They must be the same length to match.
     *
     * @param first The first array to compare (with -1 wildcard if required)
     * @param second The second array to compare
     * @return the result of the comparison
     */
    private boolean compareShorts(short[] first, short[] second) {
        if(first.length != second.length) {
            return false;
        }
        for(int i=0; i < first.length; i++) {
            if(first[i] == -1) {
                continue;
            }
            if(first[i] != second[i]) {
                return false;
            }
        }
        return true;
    }

//---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 = DEFMODE;

//---STATIC ATTRIBUTES---

//---INNER CLASSES---

    /**
     * Wrapper class for an ACL rule.
     */
    private class ACLRule implements Serializable {
        
        /**
         * Construct an ACL rule.
         *
         * @param allow whether this is an ALLOW or DENY rule
         * @param expression what this rule matches
         * @param ipaddr the IP address wildcard this rule matches if it's an IP rule
         * @param iprule whether this is an IP rule
         */
        private ACLRule(boolean allow, String expression, short[] ipaddr, boolean iprule) {
            _allow = allow;
            _expression = expression;
            _ipaddr = ipaddr;
            _iprule = iprule;
        }
        
        /**
         * Returns a String representation of this rule.
         *
         * @return A String representation of this rule.
         */
        public String toString() {
            if(_allow) {
                return _expression + "=ALLOW";
            }
            else {
                return _expression + "=DENY";
            }
        }
        
        /**
         * Whether this is an ALLOW or DENY rule.
         */
        private boolean _allow;
        
        /**
         * What this rule matches.
         */
        private String _expression;
        
        /**
         * The IP wildcard, only valid if this
         * is an IP rule.
         */
        private short[] _ipaddr;
        
        /**
         * Whether this is an IP rule.
         */
        private boolean _iprule;
        
    }

}
Revision:	1.5
Committed:	Sat May 18 18:16:03 2002 UTC (21 years, 11 months ago) by tdb
Branch:	MAIN
Changes since 1.4:	+21 -2 lines
Log Message:	i-scream is now licensed under the GPL. I've added the GPL headers to every source file, and put a full copy of the license in the appropriate places. I think I've covered everything. This is going to be a mad commit ;)
#	User	Rev	Content
1	tdb	1.5	/*
2			* i-scream central monitoring system
3			* Copyright (C) 2000-2002 i-scream
4			*
5			* This program is free software; you can redistribute it and/or
6			* modify it under the terms of the GNU General Public License
7			* as published by the Free Software Foundation; either version 2
8			* of the License, or (at your option) any later version.
9			*
10			* This program is distributed in the hope that it will be useful,
11			* but WITHOUT ANY WARRANTY; without even the implied warranty of
12			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13			* GNU General Public License for more details.
14			*
15			* You should have received a copy of the GNU General Public License
16			* along with this program; if not, write to the Free Software
17			* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18			*/
19
20	tdb	1.1	//---PACKAGE DECLARATION---
21			package uk.org.iscream.cms.server.util;
22
23			//---IMPORTS---
24			import java.util.ArrayList;
25			import java.util.StringTokenizer;
26			import java.net.InetAddress;
27			import java.io.Serializable;
28
29			/**
30			* Access Control List for use primarily
31			* with the ACLServerSocket. It could, however
32			* have other uses as it has a fairly generic
33			* behaviour. Rules are added using the add
34			* method, and then checks can be made using
35			* the relevant check method.
36			*
37			* @author $Author: tdb $
38	tdb	1.5	* @version $Id: ACL.java,v 1.4 2002/03/20 17:03:35 tdb Exp $
39	tdb	1.1	*/
40			public class ACL implements Serializable {
41
42			//---FINAL ATTRIBUTES---
43
44			/**
45			* The current CVS revision of this class
46			*/
47	tdb	1.5	public static final String REVISION = "$Revision: 1.4 $";
48	tdb	1.1
49			/**
50			* static to be used when adding an ALLOW rule to the ACL.
51			*/
52			public static final boolean ALLOW = true;
53
54			/**
55			* static to be used when adding a DENY rule to the ACL.
56			*/
57			public static final boolean DENY = false;
58	tdb	1.4
59			/**
60			* default setting for the default mode for a new ACL.
61			*/
62			public static final boolean DEFMODE = ACL.ALLOW;
63	tdb	1.1
64			//---STATIC METHODS---
65
66			//---CONSTRUCTORS---
67
68			/**
69			* Construct a new Access Control List. The default
70			* mode is to ALLOW anything that isn't explicitly
71			* blocked by a rule.
72			*/
73			public ACL() {
74	tdb	1.4	// default to DEFMODE
75			this(DEFMODE);
76	tdb	1.1	}
77
78			/**
79			* Construct a new Access Control List with a given
80			* default mode. This mode specifies what should
81			* happen if a check does not match any rules.
82			*
83			* @param defaultMode the default mode for non-matched checks
84			*/
85			public ACL(boolean defaultMode) {
86	tdb	1.4	setDefaultMode(defaultMode);
87	tdb	1.3	}
88
89			/**
90			* Construct a new Access Control List with a given
91			* String representation of the ACL rules. The String
92			* should be of the format:
93			* expression:rule;expression:rule;expression:rule...
94			* Where expression is a wildcard to match against, and
95			* rule is either 'ALLOW' or 'DENY'. There is a special
96			* expression of 'DEFAULT' which represents the default
97			* rule (what should happen if no expression is matched
98			* when performing a check).
99			* The default mode is set to ALLOW if one is not
100	tdb	1.4	* specified in the String.
101	tdb	1.3	*
102			* @param acl a String representation of the ACL.
103			*/
104			public ACL(String acl) {
105	tdb	1.4	setDefaultMode(DEFMODE);
106			add(acl);
107			}
108
109			//---PUBLIC METHODS---
110
111			/**
112			* Add a new rule to the ACL immediately after the
113			* previous rule. The rule can either be an ACL.ALLOW
114			* rule, or an ACL.DENY rule. The expression can
115			* contain a wildcard (a * only). Rules can only be
116			* added to the end of the list.
117			*
118			* param allow whether this is an ALLOW or DENY rule
119			* param expression what this rule matches using wildcards
120			*/
121			public void add(boolean allow, String expression) {
122			// try and convert the expression into an IP address
123			short[] ipaddr = ipStringToShort(expression);
124			// a result of null means it's not an IP address
125			// add either a name rule or an IP rule
126			if(ipaddr != null) {
127			_acl.add(new ACLRule(allow, expression, ipaddr, true));
128			}
129			else {
130			_acl.add(new ACLRule(allow, expression, ipaddr, false));
131			}
132			}
133
134			/**
135			* Add some new rules to the Access Control List in
136			* the form of a String. The String should be of the
137			* following format:
138			* expression:rule;expression:rule;expression:rule...
139			* Where expression is a wildcard to match against, and
140			* rule is either 'ALLOW' or 'DENY'. There is a special
141			* expression of 'DEFAULT' which represents the default
142			* rule (what should happen if no expression is matched
143			* when performing a check).
144			*
145			* @param acl a String representation of the ACL.
146			*/
147			public void add(String acl) {
148	tdb	1.3	if(acl != null) {
149			// split the String into expression:rule parts
150			StringTokenizer st1 = new StringTokenizer(acl, ";");
151			while(st1.hasMoreTokens()) {
152			String token1 = st1.nextToken();
153			// if it doesn't have a :, it's not the correct format
154			if(token1.indexOf(":") != -1) {
155			// split into expression and rule part
156			StringTokenizer st2 = new StringTokenizer(token1, ":");
157			String expression = "";
158			String rule = "";
159			if(st2.hasMoreTokens()) {
160			expression = st2.nextToken();
161			}
162			else {
163			// mall-formed?
164			continue;
165			}
166			if(st2.hasMoreTokens()) {
167			rule = st2.nextToken();
168			}
169			else {
170			// mall-formed?
171			continue;
172			}
173			// check to see what sort of rule
174			if(rule.equals("ALLOW")) {
175			// case for special 'DEFAULT' expression
176			if(expression.equals("DEFAULT")) {
177	tdb	1.4	setDefaultMode(ACL.ALLOW);
178	tdb	1.3	}
179			else {
180			add(ACL.ALLOW, expression);
181			}
182			}
183			else if(rule.equals("DENY")) {
184			// case for special 'DEFAULT' expression
185			if(expression.equals("DEFAULT")) {
186	tdb	1.4	setDefaultMode(ACL.DENY);
187	tdb	1.3	}
188			else {
189			add(ACL.DENY, expression);
190			}
191			}
192			// if it's not ALLOW or DENY, it's not a
193			// proper rule, so we'll ignore it
194			}
195			}
196			}
197	tdb	1.1	}
198
199			/**
200			* Check to see if a string is permitted by the
201			* ACL. Useful for testing, and non-Socket uses
202			* of this class.
203			*
204			* @param address the string to check
205			* @return whether the address was permitted by the ACL
206			*/
207			public boolean check(String address) {
208			for(int i=0; i < _acl.size(); i++) {
209			ACLRule rule = (ACLRule) _acl.get(i);
210			if(StringUtils.wildcardMatch(address, rule._expression)) {
211			return rule._allow;
212			}
213			}
214			return _defaultMode;
215			}
216
217			/**
218			* Check to see if an InetAddress is permitted
219			* by the ACL. Perfect for Socket uses of this
220			* class. A rule will either be for a name, or
221			* an IP address (this is determined in the add
222			* method), and the appropriate comparison will
223			* be performed.
224			*
225			* @param address the InetAddress to check
226			* @return whether the InetAddress was permitted by the ACL
227			*/
228			public boolean check(InetAddress address) {
229			// gather the details first
230			String hostname = address.getHostName();
231			String ip = address.getHostAddress();
232			short[] ipaddr = ipStringToShort(ip);
233			// check each rule against this InetAddress
234			for(int i=0; i < _acl.size(); i++) {
235			ACLRule rule = (ACLRule) _acl.get(i);
236			if(rule._iprule) {
237			// if this is an IP rule do a short comparison
238			// must specify the wildcarded rule first
239			if(compareShorts(rule._ipaddr, ipaddr)) {
240			return rule._allow;
241			}
242			}
243			else {
244			// if not do a full blown String comparsion
245			if(StringUtils.wildcardMatch(hostname, rule._expression)) {
246			return rule._allow;
247			}
248			}
249
250			}
251			// if we haven't matched a rule, return the default
252			return _defaultMode;
253			}
254
255			/**
256	tdb	1.4	* Clears the ACL and resets the default mode.
257			*/
258			public void clear() {
259			// just clear out our underlying ArrayList
260			// containing our ACL objects
261			_acl.clear();
262			// and reset the default mode to the default
263			setDefaultMode(DEFMODE);
264			}
265
266			/**
267			* Changes the default mode of the ACL. This is what
268			* the check will return if it does not find an explict
269			* rule to match against.
270			*
271			* @param defaultMode the new default mode
272			*/
273			public void setDefaultMode(boolean defaultMode) {
274			_defaultMode = defaultMode;
275			}
276
277			/**
278	tdb	1.1	* Gives a String representation of this ACL.
279			*
280			* @return A String representation of this ACL.
281			*/
282			public String toString() {
283			StringBuffer acl = new StringBuffer();
284			// put in the i-scream toString code
285			acl.append(FormatName.getName(_name, getClass().getName(), REVISION));
286			acl.append("{");
287			// put the value of each Rule in the result
288			for(int i=0; i < _acl.size(); i++) {
289			acl.append((ACLRule) _acl.get(i));
290			acl.append(",");
291			}
292			// put the default mode in the result
293			if(_defaultMode) {
294			acl.append("DEFAULT=ALLOW");
295			}
296			else {
297			acl.append("DEFAULT=DENY");
298			}
299			acl.append("}");
300			return acl.toString();
301			}
302
303			//---PRIVATE METHODS---
304
305			/**
306			* Converts an IP address in String format into
307			* a short array of length 4. Any wildcards, *,
308			* found in the IP address are represented by
309			* a -1. If the given String is not an IP address
310			* null is returned instead.
311			*
312			* @param ip The IP address in String format
313			* @return The IP address in a short[]
314			*/
315			private short[] ipStringToShort(String ip) {
316			// default to expecting it to be an IP
317			// we will try to disprove this :)
318			short[] ipaddr = {-1, -1, -1, -1};
319			int i = 0;
320			String s = "";
321			// tokenize the String on fullstops, so we can break
322			// up the quads of an IP (if it's an IP!)
323			StringTokenizer st = new StringTokenizer(ip, ".");
324			while(st.hasMoreTokens() && i++ < 4) {
325			s = st.nextToken();
326			// if it's a wildcard, we'll skip to the next one
327			// as no more checks are required
328			if(s.equals("*")) {
329			continue;
330			}
331			// attempt to parse it into a short
332			try {
333			short n = Short.parseShort(s);
334			// if it's an int but outside of the
335			// valid range, it can't be an IP
336			if(n < 0 \|\| n > 255) {
337			// give up checking further
338			return null;
339			}
340			ipaddr[i-1] = n;
341			}
342			// if it didn't parse as a short it can't be an IP
343			catch (NumberFormatException e) {
344			// give up checking further
345			return null;
346			}
347			}
348			// we've done 4 parts, so if there's any
349			// more this can't be an IP
350			if(st.hasMoreTokens()) {
351			return null;
352			}
353			// if we've done less than 4, see if the last one
354			// was a wildcard - if it isn't then it's not an IP
355			// -- this allows 129.12.*
356			if(i < 4 && !s.equals("*")) {
357			return null;
358			}
359			// if we had one or less entries it can't be an IP
360			// -- this disallows * matching as an IP due
361			// to the rule above
362			if(i <= 1) {
363			return null;
364			}
365			return ipaddr;
366			}
367
368			/**
369			* Compares two short arrays. The first array can contain a -1,
370			* which will always match any value -- it's a wildcard.
371			* They must be the same length to match.
372			*
373			* @param first The first array to compare (with -1 wildcard if required)
374			* @param second The second array to compare
375	tdb	1.2	* @return the result of the comparison
376	tdb	1.1	*/
377			private boolean compareShorts(short[] first, short[] second) {
378			if(first.length != second.length) {
379			return false;
380			}
381			for(int i=0; i < first.length; i++) {
382			if(first[i] == -1) {
383			continue;
384			}
385			if(first[i] != second[i]) {
386			return false;
387			}
388			}
389			return true;
390			}
391
392			//---ACCESSOR/MUTATOR METHODS---
393
394			//---ATTRIBUTES---
395
396			/**
397			* This is the friendly identifier of the
398			* component this class is running in.
399			* eg, a Filter may be called "filter1",
400			* If this class does not have an owning
401			* component, a name from the configuration
402			* can be placed here. This name could also
403			* be changed to null for utility classes.
404			*/
405			private String _name = null;
406
407			/**
408			* The ACL is stored in this ArrayList.
409			*/
410			private ArrayList _acl = new ArrayList();
411
412			/**
413			* The default mode of this ACL.
414			*/
415	tdb	1.4	private boolean _defaultMode = DEFMODE;
416	tdb	1.1
417			//---STATIC ATTRIBUTES---
418
419			//---INNER CLASSES---
420
421			/**
422			* Wrapper class for an ACL rule.
423			*/
424			private class ACLRule implements Serializable {
425
426			/**
427			* Construct an ACL rule.
428			*
429			* @param allow whether this is an ALLOW or DENY rule
430			* @param expression what this rule matches
431			* @param ipaddr the IP address wildcard this rule matches if it's an IP rule
432			* @param iprule whether this is an IP rule
433			*/
434			private ACLRule(boolean allow, String expression, short[] ipaddr, boolean iprule) {
435			_allow = allow;
436			_expression = expression;
437			_ipaddr = ipaddr;
438			_iprule = iprule;
439			}
440
441			/**
442			* Returns a String representation of this rule.
443			*
444			* @return A String representation of this rule.
445			*/
446			public String toString() {
447			if(_allow) {
448			return _expression + "=ALLOW";
449			}
450			else {
451			return _expression + "=DENY";
452			}
453			}
454
455			/**
456			* Whether this is an ALLOW or DENY rule.
457			*/
458			private boolean _allow;
459
460			/**
461			* What this rule matches.
462			*/
463			private String _expression;
464
465			/**
466			* The IP wildcard, only valid if this
467			* is an IP rule.
468			*/
469			private short[] _ipaddr;
470
471			/**
472			* Whether this is an IP rule.
473			*/
474			private boolean _iprule;
475
476			}
477
478			}