/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.tools.ant.taskdefs.optional.net;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Calendar;
import java.util.List;
import java.util.Vector;
import org.apache.commons.net.telnet.TelnetClient;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;
/**
* Automates the telnet protocol.
*
*/
public class TelnetTask extends Task {
private static final int WAIT_INTERVAL = 250;
private static final int TELNET_PORT = 23;
/**
* The userid to login with, if automated login is used
*/
private String userid = null;
/**
* The password to login with, if automated login is used
*/
private String password = null;
/**
* The server to connect to.
*/
private String server = null;
/**
* The tcp port to connect to.
*/
private int port = TELNET_PORT;
/**
* The list of read/write commands for this session
*/
private List<TelnetSubTask> telnetTasks = new Vector<>();
/**
* If true, adds a CR to beginning of login script
*/
private boolean addCarriageReturn = false;
/**
* Default time allowed for waiting for a valid response
* for all child reads. A value of 0 means no limit.
*/
private Integer defaultTimeout = null;
/**
* Verify that all parameters are included.
* Connect and possibly login
* Iterate through the list of Reads and writes
* @throws BuildException on error
*/
@Override
public void execute() throws BuildException {
/** A server name is required to continue */
if (server == null) {
throw new BuildException("No Server Specified");
}
/** A userid and password must appear together
* if they appear. They are not required.
*/
if (userid == null && password != null) {
throw new BuildException("No Userid Specified");
}
if (password == null && userid != null) {
throw new BuildException("No Password Specified");
}
/** Create the telnet client object */
AntTelnetClient telnet = null;
boolean success = false;
try {
telnet = new AntTelnetClient();
try {
telnet.connect(server, port);
} catch (IOException e) {
throw new BuildException("Can't connect to " + server);
}
/** Login if userid and password were specified */
if (userid != null && password != null) { //NOSONAR
login(telnet);
}
/** Process each sub command */
for (TelnetSubTask task : telnetTasks) {
if (task instanceof TelnetRead && defaultTimeout != null) {
((TelnetRead) task).setDefaultTimeout(defaultTimeout);
}
task.execute(telnet);
}
success = true;
} finally {
if (telnet != null && telnet.isConnected()) {
try {
telnet.disconnect();
} catch (IOException e) {
String msg = "Error disconnecting from " + server;
if (success) {
throw new BuildException(msg); //NOSONAR
} else { // don't hide inner exception
log(msg, Project.MSG_ERR);
}
}
}
}
}
/**
* Process a 'typical' login. If it differs, use the read
* and write tasks explicitly
*/
private void login(AntTelnetClient telnet) {
if (addCarriageReturn) {
telnet.sendString("\n", true);
}
telnet.waitForString("ogin:");
telnet.sendString(userid, true);
telnet.waitForString("assword:");
telnet.sendString(password, false);
}
/**
* Set the the login id to use on the server;
* required if <tt>password</tt> is set.
* @param u a <code>String</code> value
*/
public void setUserid(String u) {
this.userid = u;
}
/**
* Set the the login password to use
* required if <tt>userid</tt> is set.
* @param p a <code>String</code> value
*/
public void setPassword(String p) {
this.password = p;
}
/**
* Set the hostname or address of the remote server.
* @param m a <code>String</code> value
*/
public void setServer(String m) {
this.server = m;
}
/**
* Set the tcp port to connect to; default is 23.
* @param p an <code>int</code> value
*/
public void setPort(int p) {
this.port = p;
}
/**
* send a carriage return after connecting; optional, defaults to false.
* @param b a <code>boolean</code> value
*/
public void setInitialCR(boolean b) {
this.addCarriageReturn = b;
}
/**
* set a default timeout in seconds to wait for a response,
* zero means forever (the default)
* @param i an <code>Integer</code> value
*/
public void setTimeout(Integer i) {
this.defaultTimeout = i;
}
/**
* A string to wait for from the server.
* A subTask <read> tag was found. Create the object,
* Save it in our list, and return it.
* @return a read telnet sub task
*/
public TelnetSubTask createRead() {
TelnetSubTask task = new TelnetRead();
telnetTasks.add(task);
return task;
}
/**
* Add text to send to the server
* A subTask <write> tag was found. Create the object,
* Save it in our list, and return it.
* @return a write telnet sub task
*/
public TelnetSubTask createWrite() {
TelnetSubTask task = new TelnetWrite();
telnetTasks.add(task);
return task;
}
/**
* This class is the parent of the Read and Write tasks.
* It handles the common attributes for both.
*/
public class TelnetSubTask {
// CheckStyle:VisibilityModifier OFF - bc
protected String taskString = "";
// CheckStyle:VisibilityModifier ON
/**
* Execute the subtask.
* @param telnet the client
* @throws BuildException always as it is not allowed to instantiate this object
*/
public void execute(AntTelnetClient telnet)
throws BuildException {
throw new BuildException("Shouldn't be able instantiate a SubTask directly");
}
/**
* the message as nested text
* @param s the nested text
*/
public void addText(String s) {
setString(getProject().replaceProperties(s));
}
/**
* the message as an attribute
* @param s a <code>String</code> value
*/
public void setString(String s) {
taskString += s;
}
}
/**
* Sends text to the connected server
*/
public class TelnetWrite extends TelnetSubTask {
private boolean echoString = true;
/**
* Execute the write task.
* @param telnet the task to use
* @throws BuildException on error
*/
@Override
public void execute(AntTelnetClient telnet)
throws BuildException {
telnet.sendString(taskString, echoString);
}
/**
* Whether or not the message should be echoed to the log.
* Defaults to <code>true</code>.
* @param b a <code>boolean</code> value
*/
public void setEcho(boolean b) {
echoString = b;
}
}
/**
* Reads the output from the connected server
* until the required string is found or we time out.
*/
public class TelnetRead extends TelnetSubTask {
private Integer timeout = null;
/**
* Execute the read task.
* @param telnet the task to use
* @throws BuildException on error
*/
@Override
public void execute(AntTelnetClient telnet)
throws BuildException {
telnet.waitForString(taskString, timeout);
}
/**
* a timeout value that overrides any task wide timeout.
* @param i an <code>Integer</code> value
*/
public void setTimeout(Integer i) {
this.timeout = i;
}
/**
* Sets the default timeout if none has been set already
* @param defaultTimeout an <code>Integer</code> value
* @ant.attribute ignore="true"
*/
public void setDefaultTimeout(Integer defaultTimeout) {
if (timeout == null) {
timeout = defaultTimeout;
}
}
}
/**
* This class handles the abstraction of the telnet protocol.
* Currently it is a wrapper around <a
* href="http://jakarta.apache.org/commons/net/index.html">Jakarta
* Commons Net</a>.
*/
public class AntTelnetClient extends TelnetClient {
/**
* Read from the telnet session until the string we are
* waiting for is found
* @param s The string to wait on
*/
public void waitForString(String s) {
waitForString(s, null);
}
/**
* Read from the telnet session until the string we are
* waiting for is found or the timeout has been reached
* @param s The string to wait on
* @param timeout The maximum number of seconds to wait
*/
public void waitForString(String s, Integer timeout) {
InputStream is = this.getInputStream();
try {
StringBuilder sb = new StringBuilder();
int windowStart = -s.length();
if (timeout == null || timeout.intValue() == 0) {
while (windowStart < 0
|| !sb.substring(windowStart).equals(s)) {
sb.append((char) is.read());
windowStart++;
}
} else {
Calendar endTime = Calendar.getInstance();
endTime.add(Calendar.SECOND, timeout.intValue());
while (windowStart < 0
|| !sb.substring(windowStart).equals(s)) {
while (Calendar.getInstance().before(endTime)
&& is.available() == 0) {
Thread.sleep(WAIT_INTERVAL);
}
if (is.available() == 0) {
log("Read before running into timeout: "
+ sb.toString(), Project.MSG_DEBUG);
throw new BuildException(
"Response timed-out waiting for \"" + s + '\"',
getLocation());
}
sb.append((char) is.read());
windowStart++;
}
}
log(sb.toString(), Project.MSG_INFO);
} catch (BuildException be) {
throw be;
} catch (Exception e) {
throw new BuildException(e, getLocation());
}
}
/**
* Write this string to the telnet session.
* @param s the string to write
* @param echoString if true log the string sent
*/
public void sendString(String s, boolean echoString) {
OutputStream os = this.getOutputStream();
try {
os.write((s + "\n").getBytes());
if (echoString) {
log(s, Project.MSG_INFO);
}
os.flush();
} catch (Exception e) {
throw new BuildException(e, getLocation());
}
}
}
}