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Java > Open Source Codes > org > jboss > web > tomcat > filters > RemoteHostFilter


1 /*
2 * JBoss, Home of Professional Open Source
3 * Copyright 2005, JBoss Inc., and individual contributors as indicated
4 * by the @authors tag. See the copyright.txt in the distribution for a
5 * full listing of individual contributors.
6 *
7 * This is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU Lesser General Public License as
9 * published by the Free Software Foundation; either version 2.1 of
10 * the License, or (at your option) any later version.
11 *
12 * This software is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this software; if not, write to the Free
19 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21 */
22 package org.jboss.web.tomcat.filters;
23
24 import java.io.IOException JavaDoc;
25 import javax.servlet.Filter JavaDoc;
26 import javax.servlet.FilterChain JavaDoc;
27 import javax.servlet.FilterConfig JavaDoc;
28 import javax.servlet.ServletException JavaDoc;
29 import javax.servlet.ServletRequest JavaDoc;
30 import javax.servlet.ServletResponse JavaDoc;
31 import javax.servlet.http.HttpServletRequest JavaDoc;
32 import javax.servlet.http.HttpServletResponse JavaDoc;
33
34 import org.jboss.logging.Logger;
35
36 /**
37  * Accept or deny a request based on the IP address of the client who made the
38  * request. JDK 1.4 or higher is required.
39  * <p/>
40  * This filter is configured by setting the "allow" and/or "deny" properties to
41  * a comma-delimited list of regular expressions (in the syntax supported by the
42  * java.util.regex package) to which the client IP address will be compared.
43  * <p/>
44  * <filter>
45  * <filter-name>RemoteHostFilter</filter-name>
46  * <filter-class>org.jboss.remotehostfilter.RemoteHostFilter</filter-class>
47  * <init-param>
48  * <param-name>deny</param-name>
49  * <param-value>128.0.*,192.4.5.7</param-value>
50  * </init-param>
51  * <init-param>
52  * <param-name>allow</param-name>
53  * <param-value>192.4.5.6,127.0.0.*</param-value>
54  * </init-param>
55  * </filter>
56  * <p/>
57  * Evaluation proceeds as follows:
58  * <p/>
59  * If there are any deny expressions configured, the IP will be compared to each
60  * expression. If a match is found, this request will be rejected with a
61  * "Forbidden" HTTP response.
62  * If there are any allow expressions configured, the IP will be compared to
63  * each such expression. If a match is NOT found, this request will be rejected
64  * with a "Forbidden" HTTP response.
65  * Otherwise, the request will be rejected with a "Forbidden" HTTP response.
66  *
67  * @author Stan Silvert
68  * @version $Revision: 37459 $
69  */
70 public class RemoteHostFilter implements Filter JavaDoc
71 {
72    private static final Logger log = Logger.getLogger(RemoteHostFilter.class);
73    /** The list of hosts explicitly allowed */
74    private String JavaDoc[] allow;
75    /** The list of hosts explicitly denied */
76    private String JavaDoc[] deny;
77    /** The trace level log falg */
78    private boolean trace;
79
80    private FilterConfig JavaDoc filterConfig = null;
81
82    public RemoteHostFilter()
83    {
84       trace = log.isTraceEnabled();
85    }
86
87    /**
88     * @param request The servlet request we are processing
89     * @param response The servlet response we are creating
90     * @param chain The filter chain we are processing
91     * @throws IOException if an input/output error occurs
92     * @throws ServletException if a servlet error occurs
93     */
94    public void doFilter(ServletRequest JavaDoc request,
95                         ServletResponse JavaDoc response,
96                         FilterChain JavaDoc chain)
97       throws IOException JavaDoc, ServletException JavaDoc
98    {
99       String JavaDoc clientAddr = request.getRemoteAddr();
100       if( trace )
101          log.trace("Client addres is: " + clientAddr);
102
103       if (hasMatch(clientAddr, deny))
104       {
105          handleInvalidAccess(request, response, clientAddr);
106          return;
107       }
108
109       if ((allow.length > 0) && !hasMatch(clientAddr, allow))
110       {
111          handleInvalidAccess(request, response, clientAddr);
112          return;
113       }
114
115       chain.doFilter(request, response);
116    }
117
118    private void handleInvalidAccess(ServletRequest JavaDoc request,
119                                     ServletResponse JavaDoc response,
120                                     String JavaDoc clientAddr) throws IOException JavaDoc
121    {
122       HttpServletRequest JavaDoc httpRequest = (HttpServletRequest JavaDoc) request;
123       HttpServletResponse JavaDoc httpResponse = (HttpServletResponse JavaDoc) response;
124       String JavaDoc url = httpRequest.getRequestURL().toString();
125       if( trace )
126          log.trace("Invalid access attempt to " + url + " from " + clientAddr);
127       httpResponse.sendError(HttpServletResponse.SC_FORBIDDEN);
128    }
129
130    private boolean hasMatch(String JavaDoc clientAddr, String JavaDoc[] regExps)
131    {
132       for (int i = 0; i < regExps.length; i++)
133       {
134          if (clientAddr.matches(regExps[i]))
135             return true;
136       }
137
138       return false;
139    }
140
141    /**
142     * Destroy method for this filter
143     */
144    public void destroy()
145    {
146       this.filterConfig = null;
147       this.allow = null;
148       this.deny = null;
149    }
150
151
152    /**
153     * Init method for this filter
154     */
155    public void init(FilterConfig JavaDoc filterConfig)
156    {
157       this.filterConfig = filterConfig;
158       this.allow = extractRegExps(filterConfig.getInitParameter("allow"));
159       this.deny = extractRegExps(filterConfig.getInitParameter("deny"));
160    }
161
162    private String JavaDoc[] extractRegExps(String JavaDoc initParam)
163    {
164       if (initParam == null)
165       {
166          return new String JavaDoc[0];
167       }
168       else
169       {
170          return initParam.split(",");
171       }
172    }
173
174    /**
175     * Return a String representation of this object.
176     */
177    public String JavaDoc toString()
178    {
179       if (filterConfig == null) return ("ClientAddrFilter()");
180       StringBuffer JavaDoc sb = new StringBuffer JavaDoc("ClientAddrFilter(");
181       sb.append(filterConfig);
182       sb.append(")");
183       return sb.toString();
184    }
185
186 }
187
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