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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  
28  package org.apache.http.impl.conn;
29  
30  
31  import java.net.InetAddress;
32  import java.net.InetSocketAddress;
33  import java.net.Proxy;
34  import java.net.ProxySelector;
35  import java.net.URI;
36  import java.net.URISyntaxException;
37  import java.util.List;
38  
39  import org.apache.http.HttpException;
40  import org.apache.http.HttpHost;
41  import org.apache.http.HttpRequest;
42  import org.apache.http.annotation.NotThreadSafe;
43  import org.apache.http.conn.params.ConnRouteParams;
44  import org.apache.http.conn.routing.HttpRoute;
45  import org.apache.http.conn.routing.HttpRoutePlanner;
46  import org.apache.http.conn.scheme.Scheme;
47  import org.apache.http.conn.scheme.SchemeRegistry;
48  import org.apache.http.protocol.HttpContext;
49  import org.apache.http.util.Args;
50  import org.apache.http.util.Asserts;
51  
52  
53  /**
54   * Default implementation of an {@link HttpRoutePlanner}.
55   * This implementation is based on {@link java.net.ProxySelector}.
56   * By default, it will pick up the proxy settings of the JVM, either
57   * from system properties or from the browser running the application.
58   * Additionally, it interprets some
59   * {@link org.apache.http.conn.params.ConnRoutePNames parameters},
60   * though not the {@link
61   * org.apache.http.conn.params.ConnRoutePNames#DEFAULT_PROXY DEFAULT_PROXY}.
62   * <p>
63   * The following parameters can be used to customize the behavior of this
64   * class:
65   * <ul>
66   *  <li>{@link org.apache.http.conn.params.ConnRoutePNames#LOCAL_ADDRESS}</li>
67   *  <li>{@link org.apache.http.conn.params.ConnRoutePNames#FORCED_ROUTE}</li>
68   * </ul>
69   *
70   * @since 4.0
71   *
72   * @deprecated (4.3) use {@link SystemDefaultRoutePlanner}
73   */
74  @NotThreadSafe // e.g [gs]etProxySelector()
75  @Deprecated
76  public class ProxySelectorRoutePlanner implements HttpRoutePlanner {
77  
78      /** The scheme registry. */
79      protected final SchemeRegistry schemeRegistry; // @ThreadSafe
80  
81      /** The proxy selector to use, or {@code null} for system default. */
82      protected ProxySelector proxySelector;
83  
84      /**
85       * Creates a new proxy selector route planner.
86       *
87       * @param schreg    the scheme registry
88       * @param prosel    the proxy selector, or
89       *                  {@code null} for the system default
90       */
91      public ProxySelectorRoutePlanner(final SchemeRegistry schreg,
92                                       final ProxySelector prosel) {
93          Args.notNull(schreg, "SchemeRegistry");
94          schemeRegistry = schreg;
95          proxySelector  = prosel;
96      }
97  
98      /**
99       * Obtains the proxy selector to use.
100      *
101      * @return the proxy selector, or {@code null} for the system default
102      */
103     public ProxySelector getProxySelector() {
104         return this.proxySelector;
105     }
106 
107     /**
108      * Sets the proxy selector to use.
109      *
110      * @param prosel    the proxy selector, or
111      *                  {@code null} to use the system default
112      */
113     public void setProxySelector(final ProxySelector prosel) {
114         this.proxySelector = prosel;
115     }
116 
117     public HttpRoute determineRoute(final HttpHost target,
118                                     final HttpRequest request,
119                                     final HttpContext context)
120         throws HttpException {
121 
122         Args.notNull(request, "HTTP request");
123 
124         // If we have a forced route, we can do without a target.
125         HttpRoute route =
126             ConnRouteParams.getForcedRoute(request.getParams());
127         if (route != null) {
128             return route;
129         }
130 
131         // If we get here, there is no forced route.
132         // So we need a target to compute a route.
133 
134         Asserts.notNull(target, "Target host");
135 
136         final InetAddress local =
137             ConnRouteParams.getLocalAddress(request.getParams());
138         final HttpHost proxy = determineProxy(target, request, context);
139 
140         final Scheme schm =
141             this.schemeRegistry.getScheme(target.getSchemeName());
142         // as it is typically used for TLS/SSL, we assume that
143         // a layered scheme implies a secure connection
144         final boolean secure = schm.isLayered();
145 
146         if (proxy == null) {
147             route = new HttpRoute(target, local, secure);
148         } else {
149             route = new HttpRoute(target, local, proxy, secure);
150         }
151         return route;
152     }
153 
154     /**
155      * Determines a proxy for the given target.
156      *
157      * @param target    the planned target, never {@code null}
158      * @param request   the request to be sent, never {@code null}
159      * @param context   the context, or {@code null}
160      *
161      * @return  the proxy to use, or {@code null} for a direct route
162      *
163      * @throws HttpException
164      *         in case of system proxy settings that cannot be handled
165      */
166     protected HttpHost determineProxy(final HttpHost    target,
167                                       final HttpRequest request,
168                                       final HttpContext context)
169         throws HttpException {
170 
171         // the proxy selector can be 'unset', so we better deal with null here
172         ProxySelector psel = this.proxySelector;
173         if (psel == null) {
174             psel = ProxySelector.getDefault();
175         }
176         if (psel == null) {
177             return null;
178         }
179 
180         URI targetURI = null;
181         try {
182             targetURI = new URI(target.toURI());
183         } catch (final URISyntaxException usx) {
184             throw new HttpException
185                 ("Cannot convert host to URI: " + target, usx);
186         }
187         final List<Proxy> proxies = psel.select(targetURI);
188 
189         final Proxy p = chooseProxy(proxies, target, request, context);
190 
191         HttpHost result = null;
192         if (p.type() == Proxy.Type.HTTP) {
193             // convert the socket address to an HttpHost
194             if (!(p.address() instanceof InetSocketAddress)) {
195                 throw new HttpException
196                     ("Unable to handle non-Inet proxy address: "+p.address());
197             }
198             final InetSocketAddress isa = (InetSocketAddress) p.address();
199             // assume default scheme (http)
200             result = new HttpHost(getHost(isa), isa.getPort());
201         }
202 
203         return result;
204     }
205 
206     /**
207      * Obtains a host from an {@link InetSocketAddress}.
208      *
209      * @param isa       the socket address
210      *
211      * @return  a host string, either as a symbolic name or
212      *          as a literal IP address string
213      * <p>
214      * (TODO: determine format for IPv6 addresses, with or without [brackets])
215      * </p>
216      */
217     protected String getHost(final InetSocketAddress isa) {
218 
219         //@@@ Will this work with literal IPv6 addresses, or do we
220         //@@@ need to wrap these in [] for the string representation?
221         //@@@ Having it in this method at least allows for easy workarounds.
222        return isa.isUnresolved() ?
223             isa.getHostName() : isa.getAddress().getHostAddress();
224 
225     }
226 
227     /**
228      * Chooses a proxy from a list of available proxies.
229      * The default implementation just picks the first non-SOCKS proxy
230      * from the list. If there are only SOCKS proxies,
231      * {@link Proxy#NO_PROXY Proxy.NO_PROXY} is returned.
232      * Derived classes may implement more advanced strategies,
233      * such as proxy rotation if there are multiple options.
234      *
235      * @param proxies   the list of proxies to choose from,
236      *                  never {@code null} or empty
237      * @param target    the planned target, never {@code null}
238      * @param request   the request to be sent, never {@code null}
239      * @param context   the context, or {@code null}
240      *
241      * @return  a proxy type
242      */
243     protected Proxy chooseProxy(final List<Proxy> proxies,
244                                 final HttpHost    target,
245                                 final HttpRequest request,
246                                 final HttpContext context) {
247         Args.notEmpty(proxies, "List of proxies");
248 
249         Proxy result = null;
250 
251         // check the list for one we can use
252         for (int i=0; (result == null) && (i < proxies.size()); i++) {
253 
254             final Proxy p = proxies.get(i);
255             switch (p.type()) {
256 
257             case DIRECT:
258             case HTTP:
259                 result = p;
260                 break;
261 
262             case SOCKS:
263                 // SOCKS hosts are not handled on the route level.
264                 // The socket may make use of the SOCKS host though.
265                 break;
266             }
267         }
268 
269         if (result == null) {
270             //@@@ log as warning or info that only a socks proxy is available?
271             // result can only be null if all proxies are socks proxies
272             // socks proxies are not handled on the route planning level
273             result = Proxy.NO_PROXY;
274         }
275 
276         return result;
277     }
278 
279 }
280