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    
018    package org.apache.commons.net.bsd;
019    
020    import 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     * .  Unlike RExecClient and RCommandClient, it is
051     * not possible to tell the rlogind daemon to return the standard error
052     * stream over a separate connection.
053     * {@link org.apache.commons.net.bsd.RExecClient#getErrorStream getErrorStream() }
054     *  will always return null.
055     * The standard input of the remote process can be written to through
056     * the output stream returned by
057     * {@link org.apache.commons.net.bsd.RExecClient#getOutputStream getOutputSream() }
058     * .
059     * <p>
060     * <p>
061     * @author Daniel F. Savarese
062     * @see org.apache.commons.net.SocketClient
063     * @see RExecClient
064     * @see RCommandClient
065     ***/
066    
067    public class RLoginClient extends RCommandClient
068    {
069        /***
070         * The default rlogin port.  Set to 513 in BSD Unix and according
071         * to RFC 1282.
072         ***/
073        public static final int DEFAULT_PORT = 513;
074    
075        /***
076         * The default RLoginClient constructor.  Initializes the
077         * default port to <code> DEFAULT_PORT </code>.
078         ***/
079        public RLoginClient()
080        {
081            setDefaultPort(DEFAULT_PORT);
082        }
083    
084    
085        /***
086         * Logins into a remote machine through the rlogind daemon on the server
087         * to which the RLoginClient is connected.  After calling this method,
088         * you may interact with the remote login shell through its standard input
089         * and output streams.  Standard error is sent over the same stream as
090         * standard output.  You will typically be able to detect
091         * the termination of the remote login shell after reaching end of file
092         * on its standard output (accessible through
093         * {@link #getInputStream  getInputStream() }.  Disconnecting
094         * from the server or closing the process streams before reaching
095         * end of file will terminate the remote login shell in most cases.
096         * <p>
097         * If user authentication fails, the rlogind daemon will request that
098         * a password be entered interactively.  You will be able to read the
099         * prompt from the output stream of the RLoginClient and write the
100         * password to the input stream of the RLoginClient.
101         * <p>
102         * @param localUsername  The user account on the local machine that is
103         *        trying to login to the remote host.
104         * @param remoteUsername  The account name on the server that is
105         *        being logged in to.
106         * @param terminalType   The name of the user's terminal (e.g., "vt100",
107         *        "network", etc.)
108         * @param terminalSpeed  The speed of the user's terminal, expressed
109         *        as a baud rate or bps (e.g., 9600 or 38400)
110         * @exception IOException If the rlogin() attempt fails.  The exception
111         *            will contain a message indicating the nature of the failure.
112         ***/
113        public void rlogin(String localUsername, String remoteUsername,
114                           String terminalType, int terminalSpeed)
115        throws IOException
116        {
117            rexec(localUsername, remoteUsername, terminalType + "/" + terminalSpeed,
118                  false);
119        }
120    
121        /***
122         * Same as the other rlogin method, but no terminal speed is defined.
123         ***/
124        public void rlogin(String localUsername, String remoteUsername,
125                           String terminalType)
126        throws IOException
127        {
128            rexec(localUsername, remoteUsername, terminalType, false);
129        }
130    
131    }