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