1 /* 2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 import java.net.*; 25 import java.io.*; 26 import java.util.*; 27 import java.security.*; 28 29 /** 30 * A minimal proxy server that supports CONNECT tunneling. It does not do 31 * any header transformations. In future this could be added. 32 * Two threads are created per client connection. So, it's not 33 * intended for large numbers of parallel connections. 34 */ 35 public class ProxyServer extends Thread implements Closeable { 36 37 ServerSocket listener; 38 int port; 39 volatile boolean debug; 40 41 /** 42 * Create proxy on port (zero means don't care). Call getPort() 43 * to get the assigned port. 44 */ 45 public ProxyServer(Integer port) throws IOException { 46 this(port, false); 47 } 48 49 public ProxyServer(Integer port, Boolean debug) throws IOException { 50 this.debug = debug; 51 listener = new ServerSocket(port); 52 this.port = listener.getLocalPort(); 53 setName("ProxyListener"); 54 setDaemon(true); 55 connections = new LinkedList<>(); 56 start(); 57 } 58 59 public ProxyServer(String s) { } 60 61 /** 62 * Returns the port number this proxy is listening on 63 */ 64 public int getPort() { 65 return port; 66 } 67 68 /** 69 * Shuts down the proxy, probably aborting any connections 70 * currently open 71 */ 72 public void close() throws IOException { 73 if (debug) System.out.println("Proxy: closing"); 74 done = true; 75 listener.close(); 76 for (Connection c : connections) { 77 if (c.running()) { 78 c.close(); 79 } 80 } 81 } 82 83 List<Connection> connections; 84 85 volatile boolean done; 86 87 public void run() { 88 if (System.getSecurityManager() == null) { 89 execute(); 90 } else { 91 // so calling domain does not need to have socket permission 92 AccessController.doPrivileged(new PrivilegedAction<Void>() { 93 public Void run() { 94 execute(); 95 return null; 96 } 97 }); 98 } 99 } 100 101 public void execute() { 102 try { 103 while(!done) { 104 Socket s = listener.accept(); 105 if (debug) 106 System.out.println("Client: " + s); 107 Connection c = new Connection(s); 108 connections.add(c); 109 } 110 } catch(Throwable e) { 111 if (debug && !done) { 112 System.out.println("Fatal error: Listener: " + e); 113 e.printStackTrace(); 114 } 115 } 116 } 117 118 /** 119 * Transparently forward everything, once we know what the destination is 120 */ 121 class Connection { 122 123 Socket clientSocket, serverSocket; 124 Thread out, in; 125 volatile InputStream clientIn, serverIn; 126 volatile OutputStream clientOut, serverOut; 127 128 boolean forwarding = false; 129 130 final static int CR = 13; 131 final static int LF = 10; 132 133 Connection(Socket s) throws IOException { 134 this.clientSocket= s; 135 this.clientIn = new BufferedInputStream(s.getInputStream()); 136 this.clientOut = s.getOutputStream(); 137 init(); 138 } 139 140 byte[] readHeaders(InputStream is) throws IOException { 141 byte[] outbuffer = new byte[8000]; 142 int crlfcount = 0; 143 int bytecount = 0; 144 int c; 145 while ((c=is.read()) != -1 && bytecount < outbuffer.length) { 146 outbuffer[bytecount++] = (byte)c; 147 if (debug) System.out.write(c); 148 // were looking for CRLFCRLF sequence 149 if (c == CR || c == LF) { 150 switch(crlfcount) { 151 case 0: 152 if (c == CR) crlfcount ++; 153 break; 154 case 1: 155 if (c == LF) crlfcount ++; 156 break; 157 case 2: 158 if (c == CR) crlfcount ++; 159 break; 160 case 3: 161 if (c == LF) crlfcount ++; 162 break; 163 } 164 } else { 165 crlfcount = 0; 166 } 167 if (crlfcount == 4) { 168 break; 169 } 170 } 171 byte[] ret = new byte[bytecount]; 172 System.arraycopy(outbuffer, 0, ret, 0, bytecount); 173 return ret; 174 } 175 176 boolean running() { 177 return out.isAlive() || in.isAlive(); 178 } 179 180 public void close() throws IOException { 181 if (debug) System.out.println("Closing connection (proxy)"); 182 if (serverSocket != null) serverSocket.close(); 183 if (clientSocket != null) clientSocket.close(); 184 } 185 186 int findCRLF(byte[] b) { 187 for (int i=0; i<b.length-1; i++) { 188 if (b[i] == CR && b[i+1] == LF) { 189 return i; 190 } 191 } 192 return -1; 193 } 194 195 public void init() { 196 try { 197 byte[] buf = readHeaders(clientIn); 198 int p = findCRLF(buf); 199 if (p == -1) { 200 close(); 201 return; 202 } 203 String cmd = new String(buf, 0, p, "US-ASCII"); 204 String[] params = cmd.split(" "); 205 if (params[0].equals("CONNECT")) { 206 doTunnel(params[1]); 207 } else { 208 doProxy(params[1], buf, p, cmd); 209 } 210 } catch (IOException e) { 211 if (debug) { 212 System.out.println (e); 213 } 214 try {close(); } catch (IOException e1) {} 215 } 216 } 217 218 void doProxy(String dest, byte[] buf, int p, String cmdLine) 219 throws IOException 220 { 221 try { 222 URI uri = new URI(dest); 223 if (!uri.isAbsolute()) { 224 throw new IOException("request URI not absolute"); 225 } 226 dest = uri.getAuthority(); 227 // now extract the path from the URI and recreate the cmd line 228 int sp = cmdLine.indexOf(' '); 229 String method = cmdLine.substring(0, sp); 230 cmdLine = method + " " + uri.getPath() + " HTTP/1.1"; 231 int x = cmdLine.length() - 1; 232 int i = p; 233 while (x >=0) { 234 buf[i--] = (byte)cmdLine.charAt(x--); 235 } 236 i++; 237 238 commonInit(dest, 80); 239 serverOut.write(buf, i, buf.length-i); 240 proxyCommon(); 241 242 } catch (URISyntaxException e) { 243 throw new IOException(e); 244 } 245 } 246 247 void commonInit(String dest, int defaultPort) throws IOException { 248 int port; 249 String[] hostport = dest.split(":"); 250 if (hostport.length == 1) { 251 port = defaultPort; 252 } else { 253 port = Integer.parseInt(hostport[1]); 254 } 255 if (debug) System.out.printf("Server: (%s/%d)\n", hostport[0], port); 256 serverSocket = new Socket(hostport[0], port); 257 serverOut = serverSocket.getOutputStream(); 258 259 serverIn = new BufferedInputStream(serverSocket.getInputStream()); 260 } 261 262 void proxyCommon() throws IOException { 263 out = new Thread(() -> { 264 try { 265 byte[] bb = new byte[8000]; 266 int n; 267 while ((n = clientIn.read(bb)) != -1) { 268 serverOut.write(bb, 0, n); 269 } 270 serverSocket.close(); 271 clientSocket.close(); 272 } catch (IOException e) { 273 if (debug) { 274 System.out.println (e); 275 } 276 } 277 }); 278 in = new Thread(() -> { 279 try { 280 byte[] bb = new byte[8000]; 281 int n; 282 while ((n = serverIn.read(bb)) != -1) { 283 clientOut.write(bb, 0, n); 284 } 285 serverSocket.close(); 286 clientSocket.close(); 287 } catch (IOException e) { 288 if (debug) { 289 System.out.println(e); 290 e.printStackTrace(); 291 } 292 } 293 }); 294 out.setName("Proxy-outbound"); 295 out.setDaemon(true); 296 in.setDaemon(true); 297 in.setName("Proxy-inbound"); 298 out.start(); 299 in.start(); 300 } 301 302 void doTunnel(String dest) throws IOException { 303 commonInit(dest, 443); 304 clientOut.write("HTTP/1.1 200 OK\r\n\r\n".getBytes()); 305 proxyCommon(); 306 } 307 } 308 309 public static void main(String[] args) throws Exception { 310 int port = Integer.parseInt(args[0]); 311 boolean debug = args.length > 1 && args[1].equals("-debug"); 312 System.out.println("Debugging : " + debug); 313 ProxyServer ps = new ProxyServer(port, debug); 314 System.out.println("Proxy server listening on port " + ps.getPort()); 315 while (true) { 316 Thread.sleep(5000); 317 } 318 } 319 }