jdk/src/share/classes/sun/security/krb5/internal/TCPClient.java
changeset 7175 46ec4c2dbc16
parent 7174 5a56e43d896c
child 7176 19571999a46a
equal deleted inserted replaced
7174:5a56e43d896c 7175:46ec4c2dbc16
     1 /*
       
     2  * Copyright (c) 2000, 2003, 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 java.io.*;
       
    35 import java.net.*;
       
    36 
       
    37 public class TCPClient {
       
    38 
       
    39     private Socket tcpSocket;
       
    40     private BufferedOutputStream out;
       
    41     private BufferedInputStream in;
       
    42 
       
    43     public TCPClient(String hostname, int port) throws IOException {
       
    44         tcpSocket = new Socket(hostname, port);
       
    45         out = new BufferedOutputStream(tcpSocket.getOutputStream());
       
    46         in = new BufferedInputStream(tcpSocket.getInputStream());
       
    47     }
       
    48 
       
    49     public void send(byte[] data) throws IOException {
       
    50         byte[] lenField = new byte[4];
       
    51         intToNetworkByteOrder(data.length, lenField, 0, 4);
       
    52         out.write(lenField);
       
    53 
       
    54         out.write(data);
       
    55         out.flush();
       
    56     }
       
    57 
       
    58     public byte[] receive() throws IOException {
       
    59         byte[] lenField = new byte[4];
       
    60         int count = readFully(lenField, 4);
       
    61 
       
    62         if (count != 4) {
       
    63             if (Krb5.DEBUG) {
       
    64                 System.out.println(
       
    65                     ">>>DEBUG: TCPClient could not read length field");
       
    66             }
       
    67             return null;
       
    68         }
       
    69 
       
    70         int len = networkByteOrderToInt(lenField, 0, 4);
       
    71         if (Krb5.DEBUG) {
       
    72             System.out.println(
       
    73                 ">>>DEBUG: TCPClient reading " + len + " bytes");
       
    74         }
       
    75         if (len <= 0) {
       
    76             if (Krb5.DEBUG) {
       
    77                 System.out.println(
       
    78                     ">>>DEBUG: TCPClient zero or negative length field: "+len);
       
    79             }
       
    80             return null;
       
    81         }
       
    82 
       
    83         byte data[] = new byte[len];
       
    84         count = readFully(data, len);
       
    85         if (count != len) {
       
    86             if (Krb5.DEBUG) {
       
    87                 System.out.println(
       
    88                     ">>>DEBUG: TCPClient could not read complete packet (" +
       
    89                     len + "/" + count + ")");
       
    90             }
       
    91             return null;
       
    92         } else {
       
    93             return data;
       
    94         }
       
    95     }
       
    96 
       
    97     public void close() throws IOException {
       
    98         tcpSocket.close();
       
    99     }
       
   100 
       
   101     /**
       
   102      * Read requested number of bytes before returning.
       
   103      * @return The number of bytes actually read; -1 if none read
       
   104      */
       
   105     private int readFully(byte[] inBuf, int total) throws IOException {
       
   106         int count, pos = 0;
       
   107 
       
   108         while (total > 0) {
       
   109             count = in.read(inBuf, pos, total);
       
   110 
       
   111             if (count == -1) {
       
   112                 return (pos == 0? -1 : pos);
       
   113             }
       
   114             pos += count;
       
   115             total -= count;
       
   116         }
       
   117         return pos;
       
   118     }
       
   119 
       
   120     /**
       
   121      * Returns the integer represented by 4 bytes in network byte order.
       
   122      */
       
   123     private static final int networkByteOrderToInt(byte[] buf, int start,
       
   124         int count) {
       
   125         if (count > 4) {
       
   126             throw new IllegalArgumentException(
       
   127                 "Cannot handle more than 4 bytes");
       
   128         }
       
   129 
       
   130         int answer = 0;
       
   131 
       
   132         for (int i = 0; i < count; i++) {
       
   133             answer <<= 8;
       
   134             answer |= ((int)buf[start+i] & 0xff);
       
   135         }
       
   136         return answer;
       
   137     }
       
   138 
       
   139     /**
       
   140      * Encodes an integer into 4 bytes in network byte order in the buffer
       
   141      * supplied.
       
   142      */
       
   143     private static final void intToNetworkByteOrder(int num, byte[] buf,
       
   144         int start, int count) {
       
   145         if (count > 4) {
       
   146             throw new IllegalArgumentException(
       
   147                 "Cannot handle more than 4 bytes");
       
   148         }
       
   149 
       
   150         for (int i = count-1; i >= 0; i--) {
       
   151             buf[start+i] = (byte)(num & 0xff);
       
   152             num >>>= 8;
       
   153         }
       
   154     }
       
   155 }