001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.net.bsd;
019
020import java.io.IOException;
021
022/***
023 * RLoginClient is very similar to
024 * {@link org.apache.commons.net.bsd.RCommandClient},
025 * from which it is derived, and uses the rcmd() facility implemented
026 * in RCommandClient to implement the functionality of the rlogin command that
027 * first appeared in 4.2BSD Unix.  rlogin is a command used to login to
028 * a remote machine from a trusted host, sometimes without issuing a
029 * password.  The trust relationship is the same as described in
030 * the documentation for
031 * {@link org.apache.commons.net.bsd.RCommandClient}.
032 * <p>
033 * As with virtually all of the client classes in org.apache.commons.net, this
034 * class derives from SocketClient.  But it relies on the connection
035 * methods defined  in RcommandClient which ensure that the local Socket
036 * will originate from an acceptable rshell port.  The way to use
037 * RLoginClient is to first connect
038 * to the server, call the {@link #rlogin  rlogin() } method,
039 * and then
040 * fetch the connection's input and output streams.
041 * Interaction with the remote command is controlled entirely through the
042 * I/O streams.  Once you have finished processing the streams, you should
043 * invoke {@link org.apache.commons.net.bsd.RExecClient#disconnect disconnect() }
044 *  to clean up properly.
045 * <p>
046 * The standard output and standard error streams of the
047 * remote process are transmitted over the same connection, readable
048 * from the input stream returned by
049 * {@link org.apache.commons.net.bsd.RExecClient#getInputStream getInputStream() }
050 * <p>
051 * Unlike RExecClient and RCommandClient, it is
052 * not possible to tell the rlogind daemon to return the standard error
053 * stream over a separate connection.
054 * {@link org.apache.commons.net.bsd.RExecClient#getErrorStream getErrorStream() }
055 *  will always return null.
056 * The standard input of the remote process can be written to through
057 * the output stream returned by
058 * {@link org.apache.commons.net.bsd.RExecClient#getOutputStream getOutputSream() }
059 *
060 * @see org.apache.commons.net.SocketClient
061 * @see RExecClient
062 * @see RCommandClient
063 ***/
064
065public class RLoginClient extends RCommandClient
066{
067    /***
068     * The default rlogin port.  Set to 513 in BSD Unix and according
069     * to RFC 1282.
070     ***/
071    public static final int DEFAULT_PORT = 513;
072
073    /***
074     * The default RLoginClient constructor.  Initializes the
075     * default port to <code> DEFAULT_PORT </code>.
076     ***/
077    public RLoginClient()
078    {
079        setDefaultPort(DEFAULT_PORT);
080    }
081
082
083    /***
084     * Logins into a remote machine through the rlogind daemon on the server
085     * to which the RLoginClient is connected.  After calling this method,
086     * you may interact with the remote login shell through its standard input
087     * and output streams.  Standard error is sent over the same stream as
088     * standard output.  You will typically be able to detect
089     * the termination of the remote login shell after reaching end of file
090     * on its standard output (accessible through
091     * {@link #getInputStream  getInputStream() }.  Disconnecting
092     * from the server or closing the process streams before reaching
093     * end of file will terminate the remote login shell in most cases.
094     * <p>
095     * If user authentication fails, the rlogind daemon will request that
096     * a password be entered interactively.  You will be able to read the
097     * prompt from the output stream of the RLoginClient and write the
098     * password to the input stream of the RLoginClient.
099     *
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     * @param localUsername the local user
122     * @param remoteUsername the remote user
123     * @param terminalType the terminal type
124     * @throws IOException on error
125     ***/
126    public void rlogin(String localUsername, String remoteUsername,
127                       String terminalType)
128    throws IOException
129    {
130        rexec(localUsername, remoteUsername, terminalType, false);
131    }
132
133}