Author: markt
Date: Thu Nov  5 20:35:09 2009
New Revision: 833155

URL: http://svn.apache.org/viewvc?rev=833155&view=rev
Log:
https://issues.apache.org/bugzilla/show_bug.cgi?id=47330
Add RemoteIpFilter
Patch provided by Cyrille Le Clerc

Added:
    tomcat/trunk/java/org/apache/catalina/filters/RemoteIpFilter.java
Modified:
    tomcat/trunk/webapps/docs/config/filter.xml

Added: tomcat/trunk/java/org/apache/catalina/filters/RemoteIpFilter.java
URL: 
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/filters/RemoteIpFilter.java?rev=833155&view=auto
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/filters/RemoteIpFilter.java (added)
+++ tomcat/trunk/java/org/apache/catalina/filters/RemoteIpFilter.java Thu Nov  
5 20:35:09 2009
@@ -0,0 +1,943 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.catalina.filters;
+
+import java.io.IOException;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Date;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletRequestWrapper;
+import javax.servlet.http.HttpServletResponse;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+
+/**
+ * <p>
+ * Servlet filter to integrate "X-Forwarded-For" and "X-Forwarded-Proto" HTTP 
headers.
+ * </p>
+ * <p>
+ * Most of the design of this Servlet Filter is a port of <a
+ * 
href="http://httpd.apache.org/docs/trunk/mod/mod_remoteip.html";>mod_remoteip</a>,
 this servlet filter replaces the apparent client remote
+ * IP address and hostname for the request with the IP address list presented 
by a proxy or a load balancer via a request headers (e.g.
+ * "X-Forwarded-For").
+ * </p>
+ * <p>
+ * Another feature of this servlet filter is to replace the apparent scheme 
(http/https) and server port with the scheme presented by a
+ * proxy or a load balancer via a request header (e.g. "X-Forwarded-Proto").
+ * </p>
+ * <p>
+ * This servlet filter proceeds as follows:
+ * </p>
+ * <p>
+ * If the incoming <code>request.getRemoteAddr()</code> matches the servlet 
filter's list of internal proxies :
+ * <ul>
+ * <li>Loop on the comma delimited list of IPs and hostnames passed by the 
preceding load balancer or proxy in the given request's Http
+ * header named <code>$remoteIPHeader</code> (default value 
<code>x-forwarded-for</code>). Values are processed in right-to-left order.</li>
+ * <li>For each ip/host of the list:
+ * <ul>
+ * <li>if it matches the internal proxies list, the ip/host is swallowed</li>
+ * <li>if it matches the trusted proxies list, the ip/host is added to the 
created proxies header</li>
+ * <li>otherwise, the ip/host is declared to be the remote ip and looping is 
stopped.</li>
+ * </ul>
+ * </li>
+ * <li>If the request http header named <code>$protocolHeader</code> (e.g. 
<code>x-forwarded-for</code>) equals to the value of
+ * <code>protocolHeaderHttpsValue</code> configuration parameter (default 
<code>https</code>) then <code>request.isSecure = true</code>,
+ * <code>request.scheme = https</code> and <code>request.serverPort = 
443</code>. Note that 443 can be overwritten with the
+ * <code>$httpsServerPort</code> configuration parameter.</li>
+ * </ul>
+ * </p>
+ * <p>
+ * <strong>Configuration parameters:</strong>
+ * <table border="1">
+ * <tr>
+ * <th>XForwardedFilter property</th>
+ * <th>Description</th>
+ * <th>Equivalent mod_remoteip directive</th>
+ * <th>Format</th>
+ * <th>Default Value</th>
+ * </tr>
+ * <tr>
+ * <td>remoteIPHeader</td>
+ * <td>Name of the Http Header read by this servlet filter that holds the list 
of traversed IP addresses starting from the requesting client
+ * </td>
+ * <td>RemoteIPHeader</td>
+ * <td>Compliant http header name</td>
+ * <td>x-forwarded-for</td>
+ * </tr>
+ * <tr>
+ * <td>internalProxies</td>
+ * <td>List of internal proxies ip adress. If they appear in the 
<code>remoteIpHeader</code> value, they will be trusted and will not appear
+ * in the <code>proxiesHeader</code> value</td>
+ * <td>RemoteIPInternalProxy</td>
+ * <td>Comma delimited list of regular expressions (in the syntax supported by 
the {...@link java.util.regex.Pattern} library)</td>
+ * <td>10\.\d{1,3}\.\d{1,3}\.\d{1,3}, 192\.168\.\d{1,3}\.\d{1,3}, 
169\.254\.\d{1,3}\.\d{1,3}, 127\.\d{1,3}\.\d{1,3}\.\d{1,3} <br/>
+ * By default, 10/8, 192.168/16, 169.254/16 and 127/8 are allowed ; 172.16/12 
has not been enabled by default because it is complex to
+ * describe with regular expressions</td>
+ * </tr>
+ * </tr>
+ * <tr>
+ * <td>proxiesHeader</td>
+ * <td>Name of the http header created by this servlet filter to hold the list 
of proxies that have been processed in the incoming
+ * <code>remoteIPHeader</code></td>
+ * <td>RemoteIPProxiesHeader</td>
+ * <td>Compliant http header name</td>
+ * <td>x-forwarded-by</td>
+ * </tr>
+ * <tr>
+ * <td>trustedProxies</td>
+ * <td>List of trusted proxies ip adress. If they appear in the 
<code>remoteIpHeader</code> value, they will be trusted and will appear in
+ * the <code>proxiesHeader</code> value</td>
+ * <td>RemoteIPTrustedProxy</td>
+ * <td>Comma delimited list of regular expressions (in the syntax supported by 
the {...@link java.util.regex.Pattern} library)</td>
+ * <td>&nbsp;</td>
+ * </tr>
+ * <tr>
+ * <td>protocolHeader</td>
+ * <td>Name of the http header read by this servlet filter that holds the flag 
that this request</td>
+ * <td>N/A</td>
+ * <td>Compliant http header name like <code>X-Forwarded-Proto</code>, 
<code>X-Forwarded-Ssl</code> or <code>Front-End-Https</code></td>
+ * <td><code>null</code></td>
+ * </tr>
+ * <tr>
+ * <td>protocolHeaderHttpsValue</td>
+ * <td>Value of the <code>protocolHeader</code> to indicate that it is an 
Https request</td>
+ * <td>N/A</td>
+ * <td>String like <code>https</code> or <code>ON</code></td>
+ * <td><code>https</code></td>
+ * </tr>
+ * <tr>
+ * </table>
+ * </p>
+ * <p>
+ * <p>
+ * <strong>Regular expression vs. IP address blocks:</strong> 
<code>mod_remoteip</code> allows to use address blocks (e.g.
+ * <code>192.168/16</code>) to configure <code>RemoteIPInternalProxy</code> 
and <code>RemoteIPTrustedProxy</code> ; as the JVM doesnt have a
+ * library similar to <a
+ * 
href="http://apr.apache.org/docs/apr/1.3/group__apr__network__io.html#gb74d21b8898b7c40bf7fd07ad3eb993d";>apr_ipsubnet_test</a>.
+ * </p>
+ * <hr/>
+ * <p>
+ * <strong>Sample with internal proxies</strong>
+ * </p>
+ * <p>
+ * XForwardedFilter configuration:
+ * </p>
+ * <code><pre>
+ * &lt;filter&gt;
+ *    &lt;filter-name&gt;XForwardedFilter&lt;/filter-name&gt;
+ *    
&lt;filter-class&gt;fr.xebia.servlet.filter.XForwardedFilter&lt;/filter-class&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;internalProxies&lt;/param-name&gt;&lt;param-value&gt;192\.168\.0\.10,
 192\.168\.0\.11&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;remoteIPHeader&lt;/param-name&gt;&lt;param-value&gt;x-forwarded-for&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;remoteIPProxiesHeader&lt;/param-name&gt;&lt;param-value&gt;x-forwarded-by&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;protocolHeader&lt;/param-name&gt;&lt;param-value&gt;x-forwarded-proto&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ * &lt;/filter&gt;
+ * 
+ * &lt;filter-mapping&gt;
+ *    &lt;filter-name&gt;XForwardedFilter&lt;/filter-name&gt;
+ *    &lt;url-pattern&gt;/*&lt;/url-pattern&gt;
+ *    &lt;dispatcher&gt;REQUEST&lt;/dispatcher&gt;
+ * &lt;/filter-mapping&gt;</pre></code>
+ * <p>
+ * Request values:
+ * <table border="1">
+ * <tr>
+ * <th>property</th>
+ * <th>Value Before XForwardedFilter</th>
+ * <th>Value After XForwardedFilter</th>
+ * </tr>
+ * <tr>
+ * <td>request.remoteAddr</td>
+ * <td>192.168.0.10</td>
+ * <td>140.211.11.130</td>
+ * </tr>
+ * <tr>
+ * <td>request.header['x-forwarded-for']</td>
+ * <td>140.211.11.130, 192.168.0.10</td>
+ * <td>null</td>
+ * </tr>
+ * <tr>
+ * <td>request.header['x-forwarded-by']</td>
+ * <td>null</td>
+ * <td>null</td>
+ * </tr>
+ * <tr>
+ * <td>request.header['x-forwarded-proto']</td>
+ * <td>https</td>
+ * <td>https</td>
+ * </tr>
+ * <tr>
+ * <td>request.scheme</td>
+ * <td>http</td>
+ * <td>https</td>
+ * </tr>
+ * <tr>
+ * <td>request.secure</td>
+ * <td>false</td>
+ * <td>true</td>
+ * </tr>
+ * <tr>
+ * <td>request.serverPort</td>
+ * <td>80</td>
+ * <td>443</td>
+ * </tr>
+ * </table>
+ * Note : <code>x-forwarded-by</code> header is null because only internal 
proxies as been traversed by the request.
+ * <code>x-forwarded-by</code> is null because all the proxies are trusted or 
internal.
+ * </p>
+ * <hr/>
+ * <p>
+ * <strong>Sample with trusted proxies</strong>
+ * </p>
+ * <p>
+ * XForwardedFilter configuration:
+ * </p>
+ * <code><pre>
+ * &lt;filter&gt;
+ *    &lt;filter-name&gt;XForwardedFilter&lt;/filter-name&gt;
+ *    
&lt;filter-class&gt;fr.xebia.servlet.filter.XForwardedFilter&lt;/filter-class&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;internalProxies&lt;/param-name&gt;&lt;param-value&gt;192\.168\.0\.10,
 192\.168\.0\.11&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;remoteIPHeader&lt;/param-name&gt;&lt;param-value&gt;x-forwarded-for&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;remoteIPProxiesHeader&lt;/param-name&gt;&lt;param-value&gt;x-forwarded-by&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;trustedProxies&lt;/param-name&gt;&lt;param-value&gt;proxy1, 
proxy2&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ * &lt;/filter&gt;
+ * 
+ * &lt;filter-mapping&gt;
+ *    &lt;filter-name&gt;XForwardedFilter&lt;/filter-name&gt;
+ *    &lt;url-pattern&gt;/*&lt;/url-pattern&gt;
+ *    &lt;dispatcher&gt;REQUEST&lt;/dispatcher&gt;
+ * &lt;/filter-mapping&gt;</pre></code>
+ * <p>
+ * Request values:
+ * <table border="1">
+ * <tr>
+ * <th>property</th>
+ * <th>Value Before XForwardedFilter</th>
+ * <th>Value After XForwardedFilter</th>
+ * </tr>
+ * <tr>
+ * <td>request.remoteAddr</td>
+ * <td>192.168.0.10</td>
+ * <td>140.211.11.130</td>
+ * </tr>
+ * <tr>
+ * <td>request.header['x-forwarded-for']</td>
+ * <td>140.211.11.130, proxy1, proxy2</td>
+ * <td>null</td>
+ * </tr>
+ * <tr>
+ * <td>request.header['x-forwarded-by']</td>
+ * <td>null</td>
+ * <td>proxy1, proxy2</td>
+ * </tr>
+ * </table>
+ * Note : <code>proxy1</code> and <code>proxy2</code> are both trusted proxies 
that come in <code>x-forwarded-for</code> header, they both
+ * are migrated in <code>x-forwarded-by</code> header. 
<code>x-forwarded-by</code> is null because all the proxies are trusted or 
internal.
+ * </p>
+ * <hr/>
+ * <p>
+ * <strong>Sample with internal and trusted proxies</strong>
+ * </p>
+ * <p>
+ * XForwardedFilter configuration:
+ * </p>
+ * <code><pre>
+ * &lt;filter&gt;
+ *    &lt;filter-name&gt;XForwardedFilter&lt;/filter-name&gt;
+ *    
&lt;filter-class&gt;fr.xebia.servlet.filter.XForwardedFilter&lt;/filter-class&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;internalProxies&lt;/param-name&gt;&lt;param-value&gt;192\.168\.0\.10,
 192\.168\.0\.11&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;remoteIPHeader&lt;/param-name&gt;&lt;param-value&gt;x-forwarded-for&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;remoteIPProxiesHeader&lt;/param-name&gt;&lt;param-value&gt;x-forwarded-by&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;trustedProxies&lt;/param-name&gt;&lt;param-value&gt;proxy1, 
proxy2&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ * &lt;/filter&gt;
+ * 
+ * &lt;filter-mapping&gt;
+ *    &lt;filter-name&gt;XForwardedFilter&lt;/filter-name&gt;
+ *    &lt;url-pattern&gt;/*&lt;/url-pattern&gt;
+ *    &lt;dispatcher&gt;REQUEST&lt;/dispatcher&gt;
+ * &lt;/filter-mapping&gt;</pre></code>
+ * <p>
+ * Request values:
+ * <table border="1">
+ * <tr>
+ * <th>property</th>
+ * <th>Value Before XForwardedFilter</th>
+ * <th>Value After XForwardedFilter</th>
+ * </tr>
+ * <tr>
+ * <td>request.remoteAddr</td>
+ * <td>192.168.0.10</td>
+ * <td>140.211.11.130</td>
+ * </tr>
+ * <tr>
+ * <td>request.header['x-forwarded-for']</td>
+ * <td>140.211.11.130, proxy1, proxy2, 192.168.0.10</td>
+ * <td>null</td>
+ * </tr>
+ * <tr>
+ * <td>request.header['x-forwarded-by']</td>
+ * <td>null</td>
+ * <td>proxy1, proxy2</td>
+ * </tr>
+ * </table>
+ * Note : <code>proxy1</code> and <code>proxy2</code> are both trusted proxies 
that come in <code>x-forwarded-for</code> header, they both
+ * are migrated in <code>x-forwarded-by</code> header. As 
<code>192.168.0.10</code> is an internal proxy, it does not appear in
+ * <code>x-forwarded-by</code>. <code>x-forwarded-by</code> is null because 
all the proxies are trusted or internal.
+ * </p>
+ * <hr/>
+ * <p>
+ * <strong>Sample with an untrusted proxy</strong>
+ * </p>
+ * <p>
+ * XForwardedFilter configuration:
+ * </p>
+ * <code><pre>
+ * &lt;filter&gt;
+ *    &lt;filter-name&gt;XForwardedFilter&lt;/filter-name&gt;
+ *    
&lt;filter-class&gt;fr.xebia.servlet.filter.XForwardedFilter&lt;/filter-class&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;internalProxies&lt;/param-name&gt;&lt;param-value&gt;192\.168\.0\.10,
 192\.168\.0\.11&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;remoteIPHeader&lt;/param-name&gt;&lt;param-value&gt;x-forwarded-for&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;remoteIPProxiesHeader&lt;/param-name&gt;&lt;param-value&gt;x-forwarded-by&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ *    &lt;init-param&gt;
+ *       
&lt;param-name&gt;trustedProxies&lt;/param-name&gt;&lt;param-value&gt;proxy1, 
proxy2&lt;/param-value&gt;
+ *    &lt;/init-param&gt;
+ * &lt;/filter&gt;
+ * 
+ * &lt;filter-mapping&gt;
+ *    &lt;filter-name&gt;XForwardedFilter&lt;/filter-name&gt;
+ *    &lt;url-pattern&gt;/*&lt;/url-pattern&gt;
+ *    &lt;dispatcher&gt;REQUEST&lt;/dispatcher&gt;
+ * &lt;/filter-mapping&gt;</pre></code>
+ * <p>
+ * Request values:
+ * <table border="1">
+ * <tr>
+ * <th>property</th>
+ * <th>Value Before XForwardedFilter</th>
+ * <th>Value After XForwardedFilter</th>
+ * </tr>
+ * <tr>
+ * <td>request.remoteAddr</td>
+ * <td>192.168.0.10</td>
+ * <td>untrusted-proxy</td>
+ * </tr>
+ * <tr>
+ * <td>request.header['x-forwarded-for']</td>
+ * <td>140.211.11.130, untrusted-proxy, proxy1</td>
+ * <td>140.211.11.130</td>
+ * </tr>
+ * <tr>
+ * <td>request.header['x-forwarded-by']</td>
+ * <td>null</td>
+ * <td>proxy1</td>
+ * </tr>
+ * </table>
+ * Note : <code>x-forwarded-by</code> holds the trusted proxy 
<code>proxy1</code>. <code>x-forwarded-by</code> holds
+ * <code>140.211.11.130</code> because <code>untrusted-proxy</code> is not 
trusted and thus, we can not trust that
+ * <code>untrusted-proxy</code> is the actual remote ip. 
<code>request.remoteAddr</code> is <code>untrusted-proxy</code> that is an IP
+ * verified by <code>proxy1</code>.
+ * </p>
+ * <hr/>
+ */
+public class RemoteIpFilter implements Filter {
+    public static class XForwardedRequest extends HttpServletRequestWrapper {
+        
+        final static ThreadLocal<SimpleDateFormat[]> threadLocalDateFormats = 
new ThreadLocal<SimpleDateFormat[]>() {
+            @Override
+            protected SimpleDateFormat[] initialValue() {
+                return new SimpleDateFormat[] {
+                    new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz", 
Locale.US),
+                    new SimpleDateFormat("EEEEEE, dd-MMM-yy HH:mm:ss zzz", 
Locale.US),
+                    new SimpleDateFormat("EEE MMMM d HH:mm:ss yyyy", Locale.US)
+                };
+                
+            }
+        };
+        
+        protected Map<String, List<String>> headers;
+        
+        protected String remoteAddr;
+        
+        protected String remoteHost;
+        
+        protected String scheme;
+        
+        protected boolean secure;
+        
+        protected int serverPort;
+        
+        public XForwardedRequest(HttpServletRequest request) {
+            super(request);
+            this.remoteAddr = request.getRemoteAddr();
+            this.remoteHost = request.getRemoteHost();
+            this.scheme = request.getScheme();
+            this.secure = request.isSecure();
+            this.serverPort = request.getServerPort();
+            
+            headers = new HashMap<String, List<String>>();
+            for (Enumeration<String> headerNames = request.getHeaderNames(); 
headerNames.hasMoreElements();) {
+                String header = headerNames.nextElement();
+                headers.put(header, 
Collections.list(request.getHeaders(header)));
+            }
+        }
+        
+        @Override
+        public long getDateHeader(String name) {
+            String value = getHeader(name);
+            if (value == null) {
+                return -1;
+            }
+            DateFormat[] dateFormats = threadLocalDateFormats.get();
+            Date date = null;
+            for (int i = 0; ((i < dateFormats.length) && (date == null)); i++) 
{
+                DateFormat dateFormat = dateFormats[i];
+                try {
+                    date = dateFormat.parse(value);
+                } catch (Exception ParseException) {
+                    // Ignore
+                }
+            }
+            if (date == null) {
+                throw new IllegalArgumentException(value);
+            } else {
+                return date.getTime();
+            }
+        }
+        
+        @Override
+        public String getHeader(String name) {
+            Map.Entry<String, List<String>> header = getHeaderEntry(name);
+            if (header == null || header.getValue() == null || 
header.getValue().isEmpty()) {
+                return null;
+            } else {
+                return header.getValue().get(0);
+            }
+        }
+        
+        protected Map.Entry<String, List<String>> getHeaderEntry(String name) {
+            for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
+                if (entry.getKey().equalsIgnoreCase(name)) {
+                    return entry;
+                }
+            }
+            return null;
+        }
+        
+        @Override
+        public Enumeration<String> getHeaderNames() {
+            return Collections.enumeration(headers.keySet());
+        }
+        
+        @Override
+        public Enumeration<String> getHeaders(String name) {
+            Map.Entry<String, List<String>> header = getHeaderEntry(name);
+            if (header == null || header.getValue() == null) {
+                return 
Collections.enumeration(Collections.<String>emptyList());
+            } else {
+                return Collections.enumeration(header.getValue());
+            }
+        }
+        
+        @Override
+        public int getIntHeader(String name) {
+            String value = getHeader(name);
+            if (value == null) {
+                return -1;
+            } else {
+                return Integer.parseInt(value);
+            }
+        }
+        
+        @Override
+        public String getRemoteAddr() {
+            return this.remoteAddr;
+        }
+        
+        @Override
+        public String getRemoteHost() {
+            return this.remoteHost;
+        }
+        
+        @Override
+        public String getScheme() {
+            return scheme;
+        }
+        
+        @Override
+        public int getServerPort() {
+            return serverPort;
+        }
+        
+        @Override
+        public boolean isSecure() {
+            return secure;
+        }
+        
+        public void removeHeader(String name) {
+            Map.Entry<String, List<String>> header = getHeaderEntry(name);
+            if (header != null) {
+                headers.remove(header.getKey());
+            }
+        }
+        
+        public void setHeader(String name, String value) {
+            List<String> values = Arrays.asList(value);
+            Map.Entry<String, List<String>> header = getHeaderEntry(name);
+            if (header == null) {
+                headers.put(name, values);
+            } else {
+                header.setValue(values);
+            }
+            
+        }
+        
+        public void setRemoteAddr(String remoteAddr) {
+            this.remoteAddr = remoteAddr;
+        }
+        
+        public void setRemoteHost(String remoteHost) {
+            this.remoteHost = remoteHost;
+        }
+        
+        public void setScheme(String scheme) {
+            this.scheme = scheme;
+        }
+        
+        public void setSecure(boolean secure) {
+            this.secure = secure;
+        }
+        
+        public void setServerPort(int serverPort) {
+            this.serverPort = serverPort;
+        }
+    }
+    
+    /**
+     * {...@link Pattern} for a comma delimited string that support whitespace 
characters
+     */
+    private static final Pattern commaSeparatedValuesPattern = 
Pattern.compile("\\s*,\\s*");
+    
+    protected static final String HTTPS_SERVER_PORT_PARAMETER = 
"httpsServerPort";
+    
+    protected static final String INTERNAL_PROXIES_PARAMETER = 
"allowedInternalProxies";
+    
+    /**
+     * Logger
+     */
+    private static Log log = LogFactory.getLog(RemoteIpFilter.class);
+    
+    protected static final String PROTOCOL_HEADER_PARAMETER = "protocolHeader";
+    
+    protected static final String PROTOCOL_HEADER_SSL_VALUE_PARAMETER = 
"protocolHeaderSslValue";
+    
+    protected static final String PROXIES_HEADER_PARAMETER = "proxiesHeader";
+    
+    protected static final String REMOTE_IP_HEADER_PARAMETER = 
"remoteIPHeader";
+    
+    protected static final String TRUSTED_PROXIES_PARAMETER = "trustedProxies";
+    
+    /**
+     * Convert a given comma delimited list of regular expressions into an 
array of compiled {...@link Pattern}
+     * 
+     * @return array of patterns (not <code>null</code>)
+     */
+    protected static Pattern[] commaDelimitedListToPatternArray(String 
commaDelimitedPatterns) {
+        String[] patterns = 
commaDelimitedListToStringArray(commaDelimitedPatterns);
+        List<Pattern> patternsList = new ArrayList<Pattern>();
+        for (String pattern : patterns) {
+            try {
+                patternsList.add(Pattern.compile(pattern));
+            } catch (PatternSyntaxException e) {
+                throw new IllegalArgumentException("Illegal pattern syntax '" 
+ pattern + "'", e);
+            }
+        }
+        return patternsList.toArray(new Pattern[0]);
+    }
+    
+    /**
+     * Convert a given comma delimited list of regular expressions into an 
array of String
+     * 
+     * @return array of patterns (non <code>null</code>)
+     */
+    protected static String[] commaDelimitedListToStringArray(String 
commaDelimitedStrings) {
+        return (commaDelimitedStrings == null || 
commaDelimitedStrings.length() == 0) ? new String[0] : 
commaSeparatedValuesPattern
+            .split(commaDelimitedStrings);
+    }
+    
+    /**
+     * Convert an array of strings in a comma delimited string
+     */
+    protected static String listToCommaDelimitedString(List<String> 
stringList) {
+        if (stringList == null) {
+            return "";
+        }
+        StringBuilder result = new StringBuilder();
+        for (Iterator<String> it = stringList.iterator(); it.hasNext();) {
+            Object element = it.next();
+            if (element != null) {
+                result.append(element);
+                if (it.hasNext()) {
+                    result.append(", ");
+                }
+            }
+        }
+        return result.toString();
+    }
+    
+    /**
+     * Return <code>true</code> if the given <code>str</code> matches at least 
one of the given <code>patterns</code>.
+     */
+    protected static boolean matchesOne(String str, Pattern... patterns) {
+        for (Pattern pattern : patterns) {
+            if (pattern.matcher(str).matches()) {
+                return true;
+            }
+        }
+        return false;
+    }
+    
+    /**
+     * @see #setHttpsServerPort(int)
+     */
+    private int httpsServerPort = 443;
+    
+    /**
+     * @see #setInternalProxies(String)
+     */
+    private Pattern[] internalProxies = new Pattern[] {
+        Pattern.compile("10\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}"), 
Pattern.compile("192\\.168\\.\\d{1,3}\\.\\d{1,3}"),
+        Pattern.compile("169\\.254\\.\\d{1,3}\\.\\d{1,3}"), 
Pattern.compile("127\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}")
+    };
+    
+    /**
+     * @see #setProtocolHeader(String)
+     */
+    private String protocolHeader = null;
+    
+    private String protocolHeaderSslValue = "https";
+    
+    /**
+     * @see #setProxiesHeader(String)
+     */
+    private String proxiesHeader = "X-Forwarded-By";
+    
+    /**
+     * @see #setRemoteIPHeader(String)
+     */
+    private String remoteIPHeader = "X-Forwarded-For";
+    
+    /**
+     * @see #setTrustedProxies(String)
+     */
+    private Pattern[] trustedProxies = new Pattern[0];
+    
+    public void destroy() {
+        // NOOP
+    }
+    
+    public void doFilter(HttpServletRequest request, HttpServletResponse 
response, FilterChain chain) throws IOException, ServletException {
+        
+        if (matchesOne(request.getRemoteAddr(), internalProxies)) {
+            String remoteIp = null;
+            // In java 6, proxiesHeaderValue should be declared as a 
java.util.Deque
+            LinkedList<String> proxiesHeaderValue = new LinkedList<String>();
+            
+            String[] remoteIPHeaderValue = 
commaDelimitedListToStringArray(request.getHeader(remoteIPHeader));
+            int idx;
+            // loop on remoteIPHeaderValue to find the first trusted remote ip 
and to build the proxies chain
+            for (idx = remoteIPHeaderValue.length - 1; idx >= 0; idx--) {
+                String currentRemoteIp = remoteIPHeaderValue[idx];
+                remoteIp = currentRemoteIp;
+                if (matchesOne(currentRemoteIp, internalProxies)) {
+                    // do nothing, internalProxies IPs are not appended to the
+                } else if (matchesOne(currentRemoteIp, trustedProxies)) {
+                    proxiesHeaderValue.addFirst(currentRemoteIp);
+                } else {
+                    idx--; // decrement idx because break statement doesn't do 
it
+                    break;
+                }
+            }
+            // continue to loop on remoteIPHeaderValue to build the new value 
of the remoteIPHeader
+            LinkedList<String> newRemoteIpHeaderValue = new 
LinkedList<String>();
+            for (; idx >= 0; idx--) {
+                String currentRemoteIp = remoteIPHeaderValue[idx];
+                newRemoteIpHeaderValue.addFirst(currentRemoteIp);
+            }
+            
+            XForwardedRequest xRequest = new XForwardedRequest(request);
+            if (remoteIp != null) {
+                
+                xRequest.setRemoteAddr(remoteIp);
+                xRequest.setRemoteHost(remoteIp);
+                
+                if (proxiesHeaderValue.size() == 0) {
+                    xRequest.removeHeader(proxiesHeader);
+                } else {
+                    String commaDelimitedListOfProxies = 
listToCommaDelimitedString(proxiesHeaderValue);
+                    xRequest.setHeader(proxiesHeader, 
commaDelimitedListOfProxies);
+                }
+                if (newRemoteIpHeaderValue.size() == 0) {
+                    xRequest.removeHeader(remoteIPHeader);
+                } else {
+                    String commaDelimitedRemoteIpHeaderValue = 
listToCommaDelimitedString(newRemoteIpHeaderValue);
+                    xRequest.setHeader(remoteIPHeader, 
commaDelimitedRemoteIpHeaderValue);
+                }
+            }
+            
+            if (protocolHeader != null) {
+                String protocolHeaderValue = request.getHeader(protocolHeader);
+                if (protocolHeaderValue != null && 
protocolHeaderSslValue.equalsIgnoreCase(protocolHeaderValue)) {
+                    xRequest.setSecure(true);
+                    xRequest.setScheme("https");
+                    xRequest.setServerPort(httpsServerPort);
+                }
+            }
+            
+            if (log.isDebugEnabled()) {
+                log.debug("Incoming request " + request.getRequestURI() + " 
with originalRemoteAddr '" + request.getRemoteAddr()
+                          + "', originalRemoteHost='" + 
request.getRemoteHost() + "', originalSecure='" + request.isSecure()
+                          + "', originalScheme='" + request.getScheme() + "', 
original[" + remoteIPHeader + "]='"
+                          + request.getHeader(remoteIPHeader) + ", original[" 
+ protocolHeader + "]='"
+                          + request.getHeader(protocolHeader) + "' will be 
seen as newRemoteAddr='" + xRequest.getRemoteAddr()
+                          + "', newRemoteHost='" + xRequest.getRemoteHost() + 
"', newScheme='" + xRequest.getScheme() + "', newSecure='"
+                          + xRequest.isSecure() + "', new[" + remoteIPHeader + 
"]='" + xRequest.getHeader(remoteIPHeader) + ", new["
+                          + proxiesHeader + "]='" + 
xRequest.getHeader(proxiesHeader) + "'");
+            }
+            chain.doFilter(xRequest, response);
+        } else {
+            chain.doFilter(request, response);
+        }
+        
+    }
+    
+    /**
+     * Wrap the incoming <code>request</code> in a {...@link 
XForwardedRequest} if the http header <code>x-forwareded-for</code> is not 
empty.
+     */
+    public void doFilter(ServletRequest request, ServletResponse response, 
FilterChain chain) throws IOException, ServletException {
+        if (request instanceof HttpServletRequest && response instanceof 
HttpServletResponse) {
+            doFilter((HttpServletRequest)request, 
(HttpServletResponse)response, chain);
+        } else {
+            chain.doFilter(request, response);
+        }
+    }
+    
+    public int getHttpsServerPort() {
+        return httpsServerPort;
+    }
+    
+    public Pattern[] getInternalProxies() {
+        return internalProxies;
+    }
+    
+    public String getProtocolHeader() {
+        return protocolHeader;
+    }
+    
+    public String getProtocolHeaderSslValue() {
+        return protocolHeaderSslValue;
+    }
+    
+    public String getProxiesHeader() {
+        return proxiesHeader;
+    }
+    
+    public String getRemoteIPHeader() {
+        return remoteIPHeader;
+    }
+    
+    public Pattern[] getTrustedProxies() {
+        return trustedProxies;
+    }
+    
+    public void init(FilterConfig filterConfig) throws ServletException {
+        if (filterConfig.getInitParameter(INTERNAL_PROXIES_PARAMETER) != null) 
{
+            
setInternalProxies(filterConfig.getInitParameter(INTERNAL_PROXIES_PARAMETER));
+        }
+        
+        if (filterConfig.getInitParameter(PROTOCOL_HEADER_PARAMETER) != null) {
+            
setProtocolHeader(filterConfig.getInitParameter(PROTOCOL_HEADER_PARAMETER));
+        }
+        
+        if (filterConfig.getInitParameter(PROTOCOL_HEADER_SSL_VALUE_PARAMETER) 
!= null) {
+            
setProtocolHeaderSslValue(filterConfig.getInitParameter(PROTOCOL_HEADER_SSL_VALUE_PARAMETER));
+        }
+        
+        if (filterConfig.getInitParameter(PROXIES_HEADER_PARAMETER) != null) {
+            
setProxiesHeader(filterConfig.getInitParameter(PROXIES_HEADER_PARAMETER));
+        }
+        
+        if (filterConfig.getInitParameter(REMOTE_IP_HEADER_PARAMETER) != null) 
{
+            
setRemoteIPHeader(filterConfig.getInitParameter(REMOTE_IP_HEADER_PARAMETER));
+        }
+        
+        if (filterConfig.getInitParameter(TRUSTED_PROXIES_PARAMETER) != null) {
+            
setTrustedProxies(filterConfig.getInitParameter(TRUSTED_PROXIES_PARAMETER));
+        }
+        
+        if (filterConfig.getInitParameter(HTTPS_SERVER_PORT_PARAMETER) != 
null) {
+            try {
+                
setHttpsServerPort(Integer.parseInt(filterConfig.getInitParameter(HTTPS_SERVER_PORT_PARAMETER)));
+            } catch (NumberFormatException e) {
+                throw new NumberFormatException("Illegal serverPort : " + 
e.getMessage());
+            }
+        }
+    }
+    
+    /**
+     * <p>
+     * Server Port value if the {...@link #protocolHeader} indicates HTTPS
+     * </p>
+     * <p>
+     * Default value : 443
+     * </p>
+     */
+    public void setHttpsServerPort(int httpsServerPort) {
+        this.httpsServerPort = httpsServerPort;
+    }
+    
+    /**
+     * <p>
+     * Comma delimited list of internal proxies. Can be expressed with regular 
expressions.
+     * </p>
+     * <p>
+     * Default value : 10\.\d{1,3}\.\d{1,3}\.\d{1,3}, 
192\.168\.\d{1,3}\.\d{1,3}, 127\.\d{1,3}\.\d{1,3}\.\d{1,3}
+     * </p>
+     */
+    public void setInternalProxies(String internalProxies) {
+        this.internalProxies = 
commaDelimitedListToPatternArray(internalProxies);
+    }
+    
+    /**
+     * <p>
+     * Header that holds the incoming protocol, usally named 
<code>X-Forwarded-Proto</code>. If <code>null</code>, request.scheme and
+     * request.secure will not be modified.
+     * </p>
+     * <p>
+     * Default value : <code>null</code>
+     * </p>
+     */
+    public void setProtocolHeader(String protocolHeader) {
+        this.protocolHeader = protocolHeader;
+    }
+    
+    /**
+     * <p>
+     * Case insensitive value of the protocol header to indicate that the 
incoming http request uses SSL.
+     * </p>
+     * <p>
+     * Default value : <code>HTTPS</code>
+     * </p>
+     */
+    public void setProtocolHeaderSslValue(String protocolHeaderSslValue) {
+        this.protocolHeaderSslValue = protocolHeaderSslValue;
+    }
+    
+    /**
+     * <p>
+     * The proxiesHeader directive specifies a header into which mod_remoteip 
will collect a list of all of the intermediate client IP
+     * addresses trusted to resolve the actual remote IP. Note that 
intermediate RemoteIPTrustedProxy addresses are recorded in this header,
+     * while any intermediate RemoteIPInternalProxy addresses are discarded.
+     * </p>
+     * <p>
+     * Name of the http header that holds the list of trusted proxies that has 
been traversed by the http request.
+     * </p>
+     * <p>
+     * The value of this header can be comma delimited.
+     * </p>
+     * <p>
+     * Default value : <code>X-Forwarded-By</code>
+     * </p>
+     */
+    public void setProxiesHeader(String proxiesHeader) {
+        this.proxiesHeader = proxiesHeader;
+    }
+    
+    /**
+     * <p>
+     * Name of the http header from which the remote ip is extracted.
+     * </p>
+     * <p>
+     * The value of this header can be comma delimited.
+     * </p>
+     * <p>
+     * Default value : <code>X-Forwarded-For</code>
+     * </p>
+     */
+    public void setRemoteIPHeader(String remoteIPHeader) {
+        this.remoteIPHeader = remoteIPHeader;
+    }
+    
+    /**
+     * <p>
+     * Comma delimited list of proxies that are trusted when they appear in 
the {...@link #remoteIPHeader} header. Can be expressed as a
+     * regular expression.
+     * </p>
+     * <p>
+     * Default value : empty list, no external proxy is trusted.
+     * </p>
+     */
+    public void setTrustedProxies(String trustedProxies) {
+        this.trustedProxies = commaDelimitedListToPatternArray(trustedProxies);
+    }
+}

Modified: tomcat/trunk/webapps/docs/config/filter.xml
URL: 
http://svn.apache.org/viewvc/tomcat/trunk/webapps/docs/config/filter.xml?rev=833155&r1=833154&r2=833155&view=diff
==============================================================================
--- tomcat/trunk/webapps/docs/config/filter.xml (original)
+++ tomcat/trunk/webapps/docs/config/filter.xml Thu Nov  5 20:35:09 2009
@@ -194,6 +194,92 @@
 </section>
 
 
+<section name="Remote IP Filter">
+
+  <subsection name="Introduction">
+
+    <p>Tomcat port of
+    <a 
href="http://httpd.apache.org/docs/trunk/mod/mod_remoteip.html";>mod_remoteip</a>,
+    this filter replaces the apparent client remote IP address and hostname for
+    the request with the IP address list presented by a proxy or a load 
balancer
+    via a request headers (e.g. &quot;X-Forwarded-For&quot;).</p>
+
+    <p>Another feature of this filter is to replace the apparent scheme
+    (http/https) and server port with the scheme presented by a proxy or a load
+    balancer via a request header (e.g. &quot;X-Forwarded-Proto&quot;).</p>
+ 
+    <p>If used in conjunction with Remote Address/Host filters then this filter
+    should be defined first to ensure that the correct client IP address is
+    presented to the Remote Address/Host filters.</p>
+   
+  </subsection>
+
+  <subsection name="Filter Class Name">
+
+    <p>The filter class name for the Remote IP Filter is
+    <strong><code>org.apache.catalina.filters.RemoteIpFilter</code>
+    </strong>.</p>
+
+  </subsection>
+
+  <subsection name="Initialisation parameters">
+  
+    <p>The <strong>Remote IP Filter</strong> supports the
+    following initialisation parameters:</p>
+
+    <attributes>
+
+      <attribute name="remoteIPHeader" required="false">
+        <p>Name of the HTTP Header read by this valve that holds the list of
+        traversed IP addresses starting from the requesting client. If not
+        specified, the default of <code>x-forwarded-for</code> is used.</p>
+      </attribute>
+
+      <attribute name="internalProxies" required="false">
+        <p>List of internal proxies' IP addresses as comma separated regular
+        expressions. If they appear in the <strong>remoteIpHeader</strong>
+        value, they will be trusted and will not appear in the
+        <strong>proxiesHeader</strong> value. If not specified the default 
value
+        of <code>10\.\d{1,3}\.\d{1,3}\.\d{1,3}, 192\.168\.\d{1,3}\.\d{1,3},
+        169\.254\.\d{1,3}\.\d{1,3}, 127\.\d{1,3}\.\d{1,3}\.\d{1,3}</code> will
+        be used.</p>
+      </attribute>
+
+      <attribute name="proxiesHeader" required="false">
+        <p>Name of the HTTP header created by this valve to hold the list of
+        proxies that have been processed in the incoming
+        <strong>remoteIpHeader</strong>. If not specified, the default of
+        <code>x-forwarded-by</code> is used.</p>
+      </attribute>
+
+      <attribute name="trustedProxies" required="false">
+        <p>List of trusted proxies' IP addresses as comma separated regular
+        expressions. If they appear in the <strong>remoteIpHeader</strong>
+        value, they will be trusted and will appear in the
+        <strong>proxiesHeader</strong> value. If not specified, no proxies will
+        be trusted.</p>
+      </attribute>
+
+      <attribute name="protocolHeader" required="false">
+        <p>Name of the HTTP Header read by this valve that holds the protocol
+        used by the client to connect to the proxy. If not specified, the
+        default of <code>null</code> is used.</p>
+      </attribute>
+
+      <attribute name="protocolHeaderHttpsValue" required="false">
+        <p>Value of the <strong>protocolHeader</strong> to indicate that it is
+        an HTTPS request. If not specified, the default of <code>https</code> 
is
+        used.</p>
+      </attribute>
+
+    </attributes>
+
+
+  </subsection>
+
+</section>
+
+
 <section name="Request Dumper Filter">
 
   <subsection name="Introduction">



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