com.github.markusbernhardt.proxy.search.wpad.WpadProxySearchStrategyWithDHPC Maven / Gradle / Ivy
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Proxy Vole is a Java library to auto detect the platform network proxy settings.
package com.github.markusbernhardt.proxy.search.wpad;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.Proxy;
import java.net.ProxySelector;
import java.net.URL;
import java.net.UnknownHostException;
import java.util.Properties;
import com.github.markusbernhardt.proxy.ProxySearchStrategy;
import com.github.markusbernhardt.proxy.search.wpad.dhcp.DHCPMessage;
import com.github.markusbernhardt.proxy.util.Logger;
import com.github.markusbernhardt.proxy.util.ProxyException;
import com.github.markusbernhardt.proxy.util.ProxyUtil;
import com.github.markusbernhardt.proxy.util.Logger.LogLevel;
/*****************************************************************************
* Uses automatic proxy script search (WPAD) to find an PAC file automatically.
*
* 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* Outdated RFC draft: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 ([email protected]) Copyright 2009
****************************************************************************/
public class WpadProxySearchStrategyWithDHPC implements ProxySearchStrategy {
/*************************************************************************
* 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.
************************************************************************/
@Override
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);
}
}
/*************************************************************************
* Gets the printable name of the search strategy.
*
* @return the printable name of the search strategy
************************************************************************/
@Override
public String getName() {
return "wpad";
}
/*************************************************************************
* 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.");
int index = fqdn.indexOf('.');
while (index != -1 && result == null) {
fqdn = fqdn.substring(index + 1);
// if we are already on TLD level then escape
if (fqdn.indexOf('.') == -1) {
break;
}
// Try to connect to URL
try {
URL lookupURL = new URL("http://wpad." + fqdn + "/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();
}
con.disconnect();
} catch (UnknownHostException e) {
Logger.log(getClass(), LogLevel.DEBUG, "Not available!");
// Not a real error, try next address
}
index = fqdn.indexOf('.');
}
return result;
}
/*************************************************************************
* 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;
}
// Sends DHCPREQUEST Message and returns server message
@SuppressWarnings("unused")
private DHCPMessage SendRequest(DHCPMessage offerMessageIn) {
// DHCPSocket bindSocket = new DHCPSocket(DHCPMessage.CLIENT_PORT);
//
// DHCPMessage messageOut = new DHCPMessage(DHCPMessage.SERVER_PORT);
// DHCPMessage messageIn = new DHCPMessage(DHCPMessage.CLIENT_PORT);
// try {
// messageOut = offerMessageIn;
// messageOut.setOp((byte) 1); // setup message to send a DCHPREQUEST
// byte[] opt = new byte[1];
// opt[0] = DHCPMessage.DHCPREQUEST;
// messageOut.setOption(DHCPMessage.DHCPDISCOVER, opt); // change
// message type
// messageOut.setOption(REQUESTED_IP, offerMessageIn.getYiaddr());
// bindSocket.send(messageOut); // send DHCPREQUEST
// System.out.print(this.getName());
// System.out.print(" sending DHCPREQUEST for ");
// System.out.println(bytesToString(offerMessageIn
// .getOption(REQUESTED_IP)));
// boolean sentinal = true;
// while (sentinal) {
// if (bindSocket.receive(messageIn)) {
// if (messageOut.getXid() == messageIn.getXid()) {
// sentinal = false;
// } else {
// bindSocket.send(messageOut);
// }
// } else {
// bindSocket.send(messageOut);
// }
// }
// } catch (SocketException e) {
// System.err.println(e);
// } catch (IOException e) {
// System.err.println(e);
// } // end catch
// return messageIn;
return null;
}
}