- * Note: at the moment only the DNS name guessing schema is implemented. All - * others are missing. - *
- *- * For more information about WPAD: Web_Proxy_Autodiscovery_Protocol - *
- *- * Outdated RFC draft: draft-ietf-wrec-wpad-01.txt - *
- * - * @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; - } - -} -- cgit v1.2.3-55-g7522