    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     * @throws IOException If the rlogin() attempt fails.  The exception
    109     *            will contain a message indicating the nature of the failure.
    110     */
    111    public void rlogin(final String localUsername, final String remoteUsername,
    112                       final String terminalType, final 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(final String localUsername, final String remoteUsername,
    127                       final String terminalType)
    128    throws IOException
    129    {
    130        rexec(localUsername, remoteUsername, terminalType, false);
    131    }
    132
    133}