1 files changed, 315 insertions, 0 deletions
diff --git a/src/main/java/com/btr/proxy/search/wpad/WpadProxySearchStrategyWithDHPC.java b/src/main/java/com/btr/proxy/search/wpad/WpadProxySearchStrategyWithDHPC.java
new file mode 100644
index 0000000..bb56cc0
--- /dev/null
+++ b/src/main/java/com/btr/proxy/search/wpad/WpadProxySearchStrategyWithDHPC.java
@@ -0,0 +1,315 @@
+package com.btr.proxy.search.wpad;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.net.HttpURLConnection;
+import java.net.InetAddress;
+import java.net.Proxy;
+import java.net.ProxySelector;
+import java.net.SocketException;
+import java.net.URL;
+import java.net.UnknownHostException;
+import java.util.Properties;
+import java.util.Random;
+import java.util.StringTokenizer;
+
+import com.btr.proxy.search.ProxySearchStrategy;
+import com.btr.proxy.search.wpad.dhcp.DHCPMessage;
+import com.btr.proxy.search.wpad.dhcp.DHCPOptions;
+import com.btr.proxy.search.wpad.dhcp.DHCPSocket;
+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+ * Outdated RFC draft: 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 WpadProxySearchStrategyWithDHPC implements ProxySearchStrategy {
+	DHCPSocket bindSocket = null;
+	byte hwaddr[] = new byte[16];
+	InetAddress serverIP;
+	int portNum;
+	boolean gSentinel;
+	
+	/*************************************************************************
+	 * Constructor
+	 ************************************************************************/
+
+	public WpadProxySearchStrategyWithDHPC() {
+		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;
+		// using the 4th line of the file.
+		br.readLine();
+		br.readLine();
+		br.readLine();
+		input = br.readLine();
+
+		String[] addresses = input.split(" ");
+		// the first one is "search" and afterwards addresses are following.
+
+		for (int i = 0; i < addresses.length; ++i) {
+			String address = addresses[i];
+			int index = -1;
+			do {
+				address = address.substring(index + 1);
+
+				// if we are already on TLD level then escape
+				if (address.indexOf('.') == -1) {
+					break;
+				}
+
+				// Try to connect to URL
+				try {
+					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
+				}
+				index = address.indexOf('.');
+			} while (index != -1);
+		}
+
+		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.");
+		
+		// create socket.
+		try {
+			// bindSocket = new DHCPSocket(DHCPMessage.CLIENT_PORT);
+			// --> Not able to use ports under 1024 without being root.
+			this.bindSocket = new DHCPSocket(1068);
+		} catch (SocketException e) {
+			System.err.println(e);
+			return null;
+		}
+		
+		
+		
+		return null;
+	}
+
+	// Sends DHCPDISCOVER Message and returns server message
+	private DHCPMessage SendDiscover() {
+		DHCPSocket bindSocket = null;
+		try {
+			bindSocket = new DHCPSocket(1068);
+		} catch (SocketException e1) {
+			// TODO bjoern 29.10.2014 Auto-generated catch block
+			e1.printStackTrace();
+			return null;
+		}
+
+		Random ranXid = new Random();
+		DHCPMessage messageOut = new DHCPMessage(DHCPMessage.BROADCAST_ADDR,
+				DHCPMessage.SERVER_PORT);
+		DHCPMessage messageIn = new DHCPMessage(DHCPMessage.BROADCAST_ADDR,
+				DHCPMessage.SERVER_PORT);
+		try {
+			// Specify type of message: 1 = request - message, 2 = reply - message
+			messageOut.setOp((byte) 1);
+			// set Hardware type: 1 = Ethernet, 6 = IEEE 802 Networks, ...
+			messageOut.setHtype((byte) 1); // 1 = ethernet
+			// set hardware address length: 6 for MAC address
+			messageOut.setHlen((byte) 6);
+			messageOut.setHops((byte) 0);
+			// set session ID for later comparing with incoming message.
+			messageOut.setXid(ranXid.nextInt());
+			messageOut.setSecs((short) 0);
+			messageOut.setFlags((short) 0x8000);
+			// set client hardware address, in this case my own hardware address of eth0.
+			messageOut.setChaddr(ChaddrToByte("D8:D3:85:80:8F:C9"));
+
+			byte[] opt = new byte[1];
+			byte[] wpadOpt = new byte[1];
+			opt[0] = DHCPMessage.DHCPDISCOVER;
+
+			// change message type
+			messageOut.setOption(DHCPOptions.OPTION_DHCP_MESSAGE_TYPE, opt);
+			wpadOpt[0] = DHCPMessage.OPTION_DHCP_WPAD;
+			messageOut.setOption(DHCPOptions.OPTION_DHCP_PARAMETER_REQUEST_LIST, wpadOpt);
+//			messageOut.setOption(DHCPOptions.OPTION_DHCP_IP_ADRESS_REQUESTED,
+//					offerMessageIn.getYiaddr());
+			
+			bindSocket.send(messageOut); // send DHCPREQUEST
+			System.out.println("Sending DHCPDISCOVER ...");
+			boolean sentinal = true;
+			int counter = 0;
+			while (sentinal) {
+				if (counter == 2) { return null; }
+				if (bindSocket.receive(messageIn)) {
+					if (messageOut.getXid() == messageIn.getXid()) {
+						sentinal = false;
+					} else {
+						bindSocket.send(messageOut);
+						counter++;
+					}
+				} else {
+					bindSocket.send(messageOut);
+					counter++;
+				}
+			}
+		} catch (SocketException e) {
+			System.err.println(e);
+			return null;
+		} catch (IOException e) {
+			System.err.println(e);
+			return null;
+		} finally {
+			try {
+				bindSocket.close();
+			} catch (Exception e) {
+				// do nothing.
+			}
+		} // end catch
+		return messageIn;
+	}
+
+	// Main method for testing.
+	public static void main(String[] args) throws UnsupportedEncodingException {
+		WpadProxySearchStrategyWithDHPC wPSSDHCP = new WpadProxySearchStrategyWithDHPC();
+		DHCPMessage serverAnswer = wPSSDHCP.SendDiscover();
+
+		Logger.log(WpadProxySearchStrategyWithDHPC.class, LogLevel.INFO,
+				"DHCP serverAnswer: {0}", new String(serverAnswer.getOption(DHCPMessage.OPTION_DHCP_WPAD), "UTF-8"));
+	}
+
+	private byte[] ChaddrToByte(String inChaddr) {
+		StringTokenizer token = new StringTokenizer(inChaddr, ":");
+		Integer tempInt = new Integer(0);
+		byte outHwaddr[] = new byte[16];
+		int temp;
+		int i = 0;
+		while (i < 6) {
+			temp = tempInt.parseInt(token.nextToken(), 16);
+			outHwaddr[i] = (byte) temp;
+			i++;
+		}
+		return outHwaddr;
+	}
+
+}