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    1   /*
    2    * Copyright 2001-2005 The Apache Software Foundation
    3    *
    4    * Licensed under the Apache License, Version 2.0 (the "License");
    5    * you may not use this file except in compliance with the License.
    6    * You may obtain a copy of the License at
    7    *
    8    *     http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  package org.apache.commons.net.bsd;
    17
    18  import java.io.IOException;
    19
    20  /****
    21   * RLoginClient is very similar to
    22   * {@link org.apache.commons.net.bsd.RCommandClient},
    23   * from which it is derived, and uses the rcmd() facility implemented
    24   * in RCommandClient to implement the functionality of the rlogin command that
    25   * first appeared in 4.2BSD Unix.  rlogin is a command used to login to
    26   * a remote machine from a trusted host, sometimes without issuing a
    27   * password.  The trust relationship is the same as described in
    28   * the documentation for
    29   * {@link org.apache.commons.net.bsd.RCommandClient}.
    30   * <p>
    31   * As with virtually all of the client classes in org.apache.commons.net, this
    32   * class derives from SocketClient.  But it relies on the connection
    33   * methods defined  in RcommandClient which ensure that the local Socket
    34   * will originate from an acceptable rshell port.  The way to use
    35   * RLoginClient is to first connect
    36   * to the server, call the {@link #rlogin  rlogin() } method,
    37   * and then
    38   * fetch the connection's input and output streams.
    39   * Interaction with the remote command is controlled entirely through the
    40   * I/O streams.  Once you have finished processing the streams, you should
    41   * invoke {@link org.apache.commons.net.bsd.RExecClient#disconnect disconnect() }
    42   *  to clean up properly.
    43   * <p>
    44   * The standard output and standard error streams of the
    45   * remote process are transmitted over the same connection, readable
    46   * from the input stream returned by
    47   * {@link org.apache.commons.net.bsd.RExecClient#getInputStream getInputStream() }
    48   * .  Unlike RExecClient and RCommandClient, it is
    49   * not possible to tell the rlogind daemon to return the standard error
    50   * stream over a separate connection.
    51   * {@link org.apache.commons.net.bsd.RExecClient#getErrorStream getErrorStream() }
    52   *  will always return null.
    53   * The standard input of the remote process can be written to through
    54   * the output stream returned by
    55   * {@link org.apache.commons.net.bsd.RExecClient#getOutputStream getOutputSream() }
    56   * .
    57   * <p>
    58   * <p>
    59   * @author Daniel F. Savarese
    60   * @see org.apache.commons.net.SocketClient
    61   * @see RExecClient
    62   * @see RCommandClient
    63   ***/
    64
    65  public class RLoginClient extends RCommandClient
    66  {
    67      /****
    68       * The default rlogin port.  Set to 513 in BSD Unix and according
    69       * to RFC 1282.
    70       ***/
    71      public static final int DEFAULT_PORT = 513;
    72
    73      /****
    74       * The default RLoginClient constructor.  Initializes the
    75       * default port to <code> DEFAULT_PORT </code>.
    76       ***/
    77      public RLoginClient()
    78      {
    79          setDefaultPort(DEFAULT_PORT);
    80      }
    81
    82
    83      /****
    84       * Logins into a remote machine through the rlogind daemon on the server
    85       * to which the RLoginClient is connected.  After calling this method,
    86       * you may interact with the remote login shell through its standard input
    87       * and output streams.  Standard error is sent over the same stream as
    88       * standard output.  You will typically be able to detect
    89       * the termination of the remote login shell after reaching end of file
    90       * on its standard output (accessible through
    91       * {@link #getInputStream  getInputStream() }.  Disconnecting
    92       * from the server or closing the process streams before reaching
    93       * end of file will terminate the remote login shell in most cases.
    94       * <p>
    95       * If user authentication fails, the rlogind daemon will request that
    96       * a password be entered interactively.  You will be able to read the
    97       * prompt from the output stream of the RLoginClient and write the
    98       * password to the input stream of the RLoginClient.
    99       * <p>
    100      * @param localUsername  The user account on the local machine that is
    101      *        trying to login to the remote host.
    102      * @param remoteUsername  The account name on the server that is
    103      *        being logged in to.
    104      * @param terminalType   The name of the user's terminal (e.g., "vt100",
    105      *        "network", etc.)
    106      * @param terminalSpeed  The speed of the user's terminal, expressed
    107      *        as a baud rate or bps (e.g., 9600 or 38400)
    108      * @exception IOException If the rlogin() attempt fails.  The exception
    109      *            will contain a message indicating the nature of the failure.
    110      ***/
    111     public void rlogin(String localUsername, String remoteUsername,
    112                        String terminalType, int terminalSpeed)
    113     throws IOException
    114     {
    115         rexec(localUsername, remoteUsername, terminalType + "/" + terminalSpeed,
    116               false);
    117     }
    118
    119     /****
    120      * Same as the other rlogin method, but no terminal speed is defined.
    121      ***/
    122     public void rlogin(String localUsername, String remoteUsername,
    123                        String terminalType)
    124     throws IOException
    125     {
    126         rexec(localUsername, remoteUsername, terminalType, false);
    127     }
    128
    129 }