    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    }