1 /*
   2  * Copyright (c) 2000, 2013, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /*
  27  *
  28  *  (C) Copyright IBM Corp. 1999 All Rights Reserved.
  29  *  Copyright 1997 The Open Group Research Institute.  All rights reserved.
  30  */
  31 
  32 package sun.security.krb5.internal;
  33 
  34 import sun.misc.IOUtils;
  35 
  36 import java.io.*;
  37 import java.net.*;

  38 
  39 public abstract class NetClient implements AutoCloseable {
  40     public static NetClient getInstance(String protocol, String hostname, int port,
  41             int timeout) throws IOException {
  42         if (protocol.equals("TCP")) {
  43             return new TCPClient(hostname, port, timeout);
  44         } else {
  45             return new UDPClient(hostname, port, timeout);
  46         }
  47     }
  48 
  49     abstract public void send(byte[] data) throws IOException;
  50     abstract public byte[] receive() throws IOException;
  51     abstract public void close() throws IOException;
  52 }
  53 
  54 class TCPClient extends NetClient {
  55 
  56     private Socket tcpSocket;
  57     private BufferedOutputStream out;
  58     private BufferedInputStream in;
  59 
  60     TCPClient(String hostname, int port, int timeout)
  61             throws IOException {
  62         tcpSocket = new Socket();
  63         tcpSocket.connect(new InetSocketAddress(hostname, port), timeout);
  64         out = new BufferedOutputStream(tcpSocket.getOutputStream());
  65         in = new BufferedInputStream(tcpSocket.getInputStream());
  66         tcpSocket.setSoTimeout(timeout);
  67     }
  68 
  69     @Override
  70     public void send(byte[] data) throws IOException {
  71         byte[] lenField = new byte[4];
  72         intToNetworkByteOrder(data.length, lenField, 0, 4);
  73         out.write(lenField);
  74 
  75         out.write(data);
  76         out.flush();
  77     }
  78 
  79     @Override
  80     public byte[] receive() throws IOException {
  81         byte[] lenField = new byte[4];
  82         int count = readFully(lenField, 4);
  83 
  84         if (count != 4) {
  85             if (Krb5.DEBUG) {
  86                 System.out.println(
  87                     ">>>DEBUG: TCPClient could not read length field");
  88             }
  89             return null;
  90         }
  91 
  92         int len = networkByteOrderToInt(lenField, 0, 4);
  93         if (Krb5.DEBUG) {
  94             System.out.println(
  95                 ">>>DEBUG: TCPClient reading " + len + " bytes");
  96         }
  97         if (len <= 0) {
  98             if (Krb5.DEBUG) {
  99                 System.out.println(
 100                     ">>>DEBUG: TCPClient zero or negative length field: "+len);
 101             }
 102             return null;
 103         }
 104 
 105         try {
 106             return IOUtils.readFully(in, len, true);
 107         } catch (IOException ioe) {
 108             if (Krb5.DEBUG) {
 109                 System.out.println(
 110                     ">>>DEBUG: TCPClient could not read complete packet (" +
 111                     len + "/" + count + ")");
 112             }
 113             return null;
 114         }
 115     }
 116 
 117     @Override
 118     public void close() throws IOException {
 119         tcpSocket.close();
 120     }
 121 
 122     /**
 123      * Read requested number of bytes before returning.
 124      * @return The number of bytes actually read; -1 if none read
 125      */
 126     private int readFully(byte[] inBuf, int total) throws IOException {
 127         int count, pos = 0;
 128 
 129         while (total > 0) {
 130             count = in.read(inBuf, pos, total);
 131 
 132             if (count == -1) {
 133                 return (pos == 0? -1 : pos);
 134             }
 135             pos += count;
 136             total -= count;
 137         }
 138         return pos;
 139     }
 140 
 141     /**
 142      * Returns the integer represented by 4 bytes in network byte order.
 143      */
 144     private static int networkByteOrderToInt(byte[] buf, int start,
 145         int count) {
 146         if (count > 4) {
 147             throw new IllegalArgumentException(
 148                 "Cannot handle more than 4 bytes");
 149         }
 150 
 151         int answer = 0;
 152 
 153         for (int i = 0; i < count; i++) {
 154             answer <<= 8;
 155             answer |= ((int)buf[start+i] & 0xff);
 156         }
 157         return answer;
 158     }
 159 
 160     /**
 161      * Encodes an integer into 4 bytes in network byte order in the buffer
 162      * supplied.
 163      */
 164     private static void intToNetworkByteOrder(int num, byte[] buf,
 165         int start, int count) {
 166         if (count > 4) {
 167             throw new IllegalArgumentException(
 168                 "Cannot handle more than 4 bytes");
 169         }
 170 
 171         for (int i = count-1; i >= 0; i--) {
 172             buf[start+i] = (byte)(num & 0xff);
 173             num >>>= 8;
 174         }
 175     }
 176 }
 177 
 178 class UDPClient extends NetClient {
 179     InetAddress iaddr;
 180     int iport;
 181     int bufSize = 65507;
 182     DatagramSocket dgSocket;
 183     DatagramPacket dgPacketIn;
 184 
 185     UDPClient(String hostname, int port, int timeout)
 186         throws UnknownHostException, SocketException {
 187         iaddr = InetAddress.getByName(hostname);
 188         iport = port;
 189         dgSocket = new DatagramSocket();
 190         dgSocket.setSoTimeout(timeout);
 191         dgSocket.connect(iaddr, iport);
 192     }
 193 
 194     @Override
 195     public void send(byte[] data) throws IOException {
 196         DatagramPacket dgPacketOut = new DatagramPacket(data, data.length,
 197                                                         iaddr, iport);
 198         dgSocket.send(dgPacketOut);
 199     }
 200 
 201     @Override
 202     public byte[] receive() throws IOException {
 203         byte[] ibuf = new byte[bufSize];
 204         dgPacketIn = new DatagramPacket(ibuf, ibuf.length);
 205         try {
 206             dgSocket.receive(dgPacketIn);
 207         }
 208         catch (SocketException e) {
 209             if (e instanceof PortUnreachableException) {
 210                 throw e;
 211             }
 212             dgSocket.receive(dgPacketIn);
 213         }
 214         byte[] data = new byte[dgPacketIn.getLength()];
 215         System.arraycopy(dgPacketIn.getData(), 0, data, 0,
 216                          dgPacketIn.getLength());
 217         return data;
 218     }
 219 
 220     @Override
 221     public void close() {
 222         dgSocket.close();
 223     }
 224 }
--- EOF ---