1 files changed, 234 insertions, 0 deletions
diff --git a/src/main/java/com/btr/proxy/search/wpad/WpadProxySearchStrategy.java b/src/main/java/com/btr/proxy/search/wpad/WpadProxySearchStrategy.java
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+++ b/src/main/java/com/btr/proxy/search/wpad/WpadProxySearchStrategy.java
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+package com.btr.proxy.search.wpad;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.net.HttpURLConnection;
+import java.net.Proxy;
+import java.net.ProxySelector;
+import java.net.Socket;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.net.UnknownHostException;
+import java.util.List;
+import java.util.Properties;
+
+import com.btr.proxy.search.ProxySearchStrategy;
+import com.btr.proxy.util.Logger;
+import com.btr.proxy.util.Logger.LogLevel;
+import com.btr.proxy.util.ProxyException;
+import com.btr.proxy.util.ProxyUtil;
+
+
+/*****************************************************************************
+ * Uses automatic proxy script search (WPAD) to find an PAC file automatically.
+ * <p>
+ * Note: at the moment only the DNS name guessing schema is implemented. 
+ * All others are missing.
+ * </p><p>
+ * For more information about WPAD:
+ * <a href="http://en.wikipedia.org/wiki/Web_Proxy_Autodiscovery_Protocol">Web_Proxy_Autodiscovery_Protocol</a>
+ * </p><p>
+ * Outdated RFC draft:
+ * <a href="http://www.web-cache.com/Writings/Internet-Drafts/draft-ietf-wrec-wpad-01.txt">draft-ietf-wrec-wpad-01.txt</a>
+ * </p>
+ * @author Bernd Rosstauscher (proxyvole@rosstauscher.de) Copyright 2009
+ ****************************************************************************/
+
+public class WpadProxySearchStrategy implements ProxySearchStrategy {
+	
+	/*************************************************************************
+	 * Constructor
+	 ************************************************************************/
+	
+	public WpadProxySearchStrategy() {
+		super();
+	}
+	
+	/*************************************************************************
+	 * Loads the proxy settings from a PAC file. 
+	 * The location of the PAC file is determined automatically.
+	 * @return a configured ProxySelector, null if none is found.
+	 * @throws ProxyException on error. 
+	 ************************************************************************/
+
+	public ProxySelector getProxySelector() throws ProxyException {
+		try {
+			Logger.log(getClass(), LogLevel.TRACE, "Using WPAD to find a proxy");
+
+			String pacScriptUrl = detectScriptUrlPerDHCP();
+			if (pacScriptUrl == null) {
+				pacScriptUrl = detectScriptUrlPerDNS();
+			}
+			if (pacScriptUrl == null) {
+				return null;
+			}
+			Logger.log(getClass(), LogLevel.TRACE, "PAC script url found: {0}", pacScriptUrl);
+			return ProxyUtil.buildPacSelectorForUrl(pacScriptUrl);
+		} catch (IOException e) {
+			Logger.log(getClass(), LogLevel.ERROR, "Error during WPAD search.", e);
+			throw new ProxyException(e);
+		}
+	}
+	
+	/*************************************************************************
+	 * Loads the settings and stores them in a properties map.
+	 * @return the settings.
+	 ************************************************************************/
+	
+	public Properties readSettings() {
+		try {
+			String pacScriptUrl = detectScriptUrlPerDHCP();
+			if (pacScriptUrl == null) {
+				pacScriptUrl = detectScriptUrlPerDNS();
+			}
+			if (pacScriptUrl == null) {
+				return null;
+			}
+			Properties result = new Properties();
+			result.setProperty("url", pacScriptUrl);
+			return result;
+		} catch (IOException e) {
+			// Ignore and return empty properties.
+			return new Properties();
+		}
+	}
+
+	/*************************************************************************
+	 * Uses DNS to find the script URL.
+	 * Attention: this detection method is known to have some severe security issues. 
+	 * @return the URL, null if not found.
+	 ************************************************************************/
+	
+	private String detectScriptUrlPerDNS() throws IOException {
+		String result = null;
+		// String fqdn = InetAddress.getLocalHost().getCanonicalHostName();
+
+		Logger.log(getClass(), LogLevel.TRACE, "Searching per DNS guessing.");
+		// Logger.log(getClass(), LogLevel.INFO, "fqdn: ", fqdn);
+
+		/** Reading address from "/etc/resolv.conf"; file looks like:
+		 * 
+		 	# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
+			#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
+			nameserver 127.0.1.1
+			search ruf.uni-freiburg.de lp.ruf.uni-freiburg.de
+		 */
+		
+		FileReader fr = new FileReader("/etc/resolv.conf");
+		BufferedReader br = new BufferedReader(fr);
+		
+		String input;
+		String[] addresses = null;
+		// using the 4th line of the file.
+		while ((input = br.readLine()) != null) {
+			if (input.startsWith("search")) {
+				// the first one is "search" and afterwards addresses are following.
+				addresses = input.substring(6).split(" ");
+				break;
+			}
+		}
+		
+		if (addresses == null) {
+			addresses = new String[]{""};
+		}
+		
+		
+		for (int i = 0; i < addresses.length; ++i) {
+			String address = addresses[i];
+			int index = -1;
+			do {
+				if (index != -1) {
+					address = address.substring(index);
+				} else {
+					address = "";
+				}
+				
+				// Try to connect to URL
+				try {
+					address = ".uni-freiburg.de";
+					URL lookupURL = new URL("http://wpad"+ address +"/wpad.dat");
+					Logger.log(getClass(), LogLevel.TRACE, "Trying url: {0}", lookupURL);
+	
+					HttpURLConnection con = (HttpURLConnection) lookupURL.openConnection(Proxy.NO_PROXY);
+					con.setInstanceFollowRedirects(true);
+					con.setRequestProperty("accept", "application/x-ns-proxy-autoconfig");
+					if (con.getResponseCode() == 200) {
+						result = lookupURL.toString();
+						return result;
+					}
+					con.disconnect();
+				} catch (UnknownHostException e) {
+					Logger.log(getClass(), LogLevel.DEBUG, "Not available!");
+					// Not a real error, try next address
+				}
+				if (address.length() == 0) {
+					break;
+				}
+				index = address.indexOf('.', 1);
+			} while (true);
+		}
+		
+		return null;
+	}
+
+	/*************************************************************************
+	 * Uses DHCP to find the script URL.
+	 * @return the URL, null if not found.
+	 ************************************************************************/
+	
+	private String detectScriptUrlPerDHCP() {
+		Logger.log(getClass(), LogLevel.DEBUG, "Searching per DHCP not supported yet.");
+		// TODO Rossi 28.04.2009 Not implemented yet.
+		return null;
+	}
+	
+	// Main method for testing.
+	public static void main( String[] args ) throws IOException {
+		WpadProxySearchStrategy wPSS = new WpadProxySearchStrategy();
+//		System.setProperty("com.btr.proxy.pac.overrideLocalIP", "10.0.0.1");
+		try {
+			ProxySelector pS = wPSS.getProxySelector();
+			ProxySelector.setDefault(pS);
+			List<Proxy> proxyList = pS.select(new URI("http://www.google.de"));
+			
+			if (proxyList.isEmpty()) {
+				Logger.log(WpadProxySearchStrategy.class, LogLevel.INFO, "ProxyList is empty!");
+			} else {
+				Logger.log(WpadProxySearchStrategy.class, LogLevel.INFO, "proxyList contains: {0}", proxyList.toString());
+			}
+		} catch (ProxyException e) {
+			// TODO bjoern 28.10.2014 Auto-generated catch block
+			e.printStackTrace();
+		} catch (URISyntaxException e) {
+			// TODO bjoern 28.10.2014 Auto-generated catch block
+			e.printStackTrace();
+		}
+		
+		URL test = new URL("http://www.google.de");
+		URLConnection uc = test.openConnection();
+		BufferedReader br = new BufferedReader(new InputStreamReader(uc.getInputStream()));
+		
+		String inputLine;
+		while ((inputLine = br.readLine()) != null) {
+			System.out.println(inputLine);
+		}
+		
+		Socket socket = new Socket("www.google.de", 80);
+		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
+		bw.write("GET / HTTP/1.1\r\nHost: www.google.de\r\nConnection: close\r\nAccept-Encoding: *\r\n\r\n");
+		bw.flush();
+		
+		br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+		while ((inputLine = br.readLine()) != null) {
+			System.out.println(inputLine);
+		}
+		
+	}
+
+}