/*
* 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.accumulo.server.monitor.servlets;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import jline.ConsoleReader;
import org.apache.accumulo.core.Constants;
import org.apache.accumulo.core.util.shell.Shell;
public class ShellServlet extends BasicServlet {
private static final long serialVersionUID = 1L;
private Map<String,ShellExecutionThread> userShells = new HashMap<String,ShellExecutionThread>();
private ExecutorService service = Executors.newCachedThreadPool();
@Override
protected String getTitle(HttpServletRequest req) {
return "Shell";
}
@Override
protected void pageBody(HttpServletRequest req, HttpServletResponse response, StringBuilder sb) throws IOException {
HttpSession session = req.getSession(true);
String user = (String) session.getAttribute("user");
if (user == null) {
// user attribute is null, check to see if username and password are passed as parameters
user = req.getParameter("user");
String pass = req.getParameter("pass");
String mock = req.getParameter("mock");
if (user == null || pass == null) {
// username or password are null, re-authenticate
sb.append(authenticationForm(req.getRequestURI()));
return;
}
try {
// get a new shell for this user
ShellExecutionThread shellThread = new ShellExecutionThread(user, pass, mock);
service.submit(shellThread);
userShells.put(session.getId(), shellThread);
} catch (IOException e) {
// error validating user, reauthenticate
sb.append("<div id='loginError'>Invalid user/password</div>" + authenticationForm(req.getRequestURI()));
return;
}
session.setAttribute("user", user);
}
if (!userShells.containsKey(session.getId())) {
// no existing shell for this user, re-authenticate
sb.append(authenticationForm(req.getRequestURI()));
return;
}
ShellExecutionThread shellThread = userShells.get(session.getId());
shellThread.getOutput();
shellThread.printInfo();
sb.append("<div id='shell'>\n");
sb.append("<pre id='shellResponse'>").append(shellThread.getOutput()).append("</pre>\n");
sb.append("<form><span id='shellPrompt'>").append(shellThread.getPrompt());
sb.append("</span><input type='text' name='cmd' id='cmd' onkeydown='return handleKeyDown(event.keyCode);'>\n");
sb.append("</form>\n</div>\n");
sb.append("<script type='text/javascript'>\n");
sb.append("var url = '").append(req.getRequestURL().toString()).append("';\n");
sb.append("var xmlhttp = new XMLHttpRequest();\n");
sb.append("var hsize = 1000;\n");
sb.append("var hindex = 0;\n");
sb.append("var history = new Array();\n");
sb.append("\n");
sb.append("function handleKeyDown(keyCode) {\n");
sb.append(" if (keyCode==13) {\n");
sb.append(" submitCmd(document.getElementById('cmd').value);\n");
sb.append(" hindex = history.length;\n");
sb.append(" return false;\n");
sb.append(" } else if (keyCode==38) {\n");
sb.append(" hindex = hindex==0 ? history.length : hindex - 1;\n");
sb.append(" if (hindex == history.length)\n");
sb.append(" document.getElementById('cmd').value = '';\n");
sb.append(" else\n");
sb.append(" document.getElementById('cmd').value = history[hindex];\n");
sb.append(" return false;\n");
sb.append(" } else if (keyCode==40) {\n");
sb.append(" hindex = hindex==history.length ? history.length : hindex + 1;\n");
sb.append(" if (hindex == history.length)\n");
sb.append(" document.getElementById('cmd').value = '';\n");
sb.append(" else\n");
sb.append(" document.getElementById('cmd').value = history[hindex];\n");
sb.append(" return false;\n");
sb.append(" }\n");
sb.append(" return true;\n");
sb.append("}\n");
sb.append("\n");
sb.append("function submitCmd(cmd) {\n");
sb.append(" if (cmd=='history') {\n");
sb.append(" document.getElementById('shellResponse').innerHTML += document.getElementById('shellPrompt').innerHTML+cmd+'\\n';\n");
sb.append(" document.getElementById('shellResponse').innerHTML += history.join('\\n');\n");
sb.append(" return\n");
sb.append(" }\n");
sb.append(" xmlhttp.open('POST',url+'?cmd='+cmd,false);\n");
sb.append(" xmlhttp.send();\n");
sb.append(" var text = xmlhttp.responseText;\n");
sb.append(" var index = text.lastIndexOf('\\n');\n");
sb.append(" if (index >= 0) {\n");
sb.append(" if (index > 0 && document.getElementById('cmd').type == 'text') {\n");
sb.append(" if (history.length == hsize)\n");
sb.append(" history.shift()\n");
sb.append(" history.push(cmd)\n");
sb.append(" }\n");
sb.append(" if (text.charAt(text.length-1)=='*') {\n");
sb.append(" document.getElementById('cmd').type = 'password';\n");
sb.append(" text = text.substring(0,xmlhttp.responseText.length-2);\n");
sb.append(" } else {\n");
sb.append(" document.getElementById('cmd').type = 'text';\n");
sb.append(" }\n");
sb.append(" document.getElementById('shellResponse').innerHTML += text.substring(0,index+1);\n");
sb.append(" document.getElementById('shellPrompt').innerHTML = text.substring(index+1);\n");
sb.append(" document.getElementById('cmd').value = '';\n");
sb.append(" document.getElementById('shell').scrollTop = document.getElementById('cmd').offsetTop;\n");
sb.append(" } else {\n");
sb.append(" window.location = url;\n");
sb.append(" }\n");
sb.append("}\n");
sb.append("</script>\n");
sb.append("<script type='text/javascript'>window.onload = function() { document.getElementById('cmd').select(); }</script>\n");
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
HttpSession session = req.getSession(true);
String user = (String) session.getAttribute("user");
if (user == null || !userShells.containsKey(session.getId())) {
// no existing shell for user, re-authenticate
doGet(req, resp);
return;
}
ShellExecutionThread shellThread = userShells.get(session.getId());
String cmd = req.getParameter("cmd");
if (cmd == null) {
// the command is null, just print prompt
resp.getWriter().append(shellThread.getPrompt());
resp.getWriter().flush();
return;
}
shellThread.addInputString(cmd);
shellThread.waitUntilReady();
if (shellThread.isDone()) {
// the command was exit, invalidate session
userShells.remove(session.getId());
session.invalidate();
return;
}
// get the shell's output
StringBuilder sb = new StringBuilder();
sb.append(shellThread.getOutput().replace("<", "<").replace(">", ">"));
if (sb.length() == 0 || !(sb.charAt(sb.length() - 1) == '\n'))
sb.append("\n");
// check if shell is waiting for input
if (!shellThread.isWaitingForInput())
sb.append(shellThread.getPrompt());
// check if shell is waiting for password input
if (shellThread.isMasking())
sb.append("*");
resp.getWriter().append(sb.toString());
resp.getWriter().flush();
}
private String authenticationForm(String requestURI) {
return "<div id='login'><form method=POST action='" + requestURI + "'>"
+ "<table><tr><td>Mock: </td><td><input type='checkbox' name='mock' value='mock'></td></tr>"
+ "<tr><td>Username: </td><td><input type='text' name='user'></td></tr>"
+ "<tr><td>Password: </td><td><input type='password' name='pass'></td><td><input type='submit' value='Enter'></td></tr></table></form></div>";
}
private static class StringBuilderOutputStream extends OutputStream {
StringBuilder sb = new StringBuilder();
@Override
public void write(int b) throws IOException {
sb.append((char) (0xff & b));
}
public String get() {
return sb.toString();
}
public void clear() {
sb.setLength(0);
}
}
private static class ShellExecutionThread extends InputStream implements Runnable {
private Shell shell;
StringBuilderOutputStream output;
private String cmd;
private int cmdIndex;
private boolean done;
private boolean readWait;
private ShellExecutionThread(String username, String password, String mock) throws IOException {
this.done = false;
this.cmd = null;
this.cmdIndex = 0;
this.readWait = false;
this.output = new StringBuilderOutputStream();
ConsoleReader reader = new ConsoleReader(this, new OutputStreamWriter(output, Constants.UTF8));
this.shell = new Shell(reader, new PrintWriter(new OutputStreamWriter(output, Constants.UTF8)));
shell.setLogErrorsToConsole();
if (mock != null) {
if (shell.config("--fake", "-u", username, "-p", password))
throw new IOException("mock shell config error");
} else if (shell.config("-u", username, "-p", password)) {
throw new IOException("shell config error");
}
}
@Override
public synchronized int read() throws IOException {
if (cmd == null) {
readWait = true;
this.notifyAll();
}
while (cmd == null) {
try {
this.wait();
} catch (InterruptedException e) {}
}
readWait = false;
int c;
if (cmdIndex == cmd.length())
c = '\n';
else
c = cmd.charAt(cmdIndex);
cmdIndex++;
if (cmdIndex > cmd.length()) {
cmd = null;
cmdIndex = 0;
this.notifyAll();
}
return c;
}
@Override
public synchronized void run() {
Thread.currentThread().setName("shell thread");
while (!shell.hasExited()) {
while (cmd == null) {
try {
this.wait();
} catch (InterruptedException e) {}
}
String tcmd = cmd;
cmd = null;
cmdIndex = 0;
try {
shell.execCommand(tcmd, false, true);
} catch (IOException e) {}
this.notifyAll();
}
done = true;
this.notifyAll();
}
public synchronized void addInputString(String s) {
if (done)
throw new IllegalStateException("adding string to exited shell");
if (cmd == null) {
cmd = s;
} else {
throw new IllegalStateException("adding string to shell not waiting for input");
}
this.notifyAll();
}
public synchronized void waitUntilReady() {
while (cmd != null) {
try {
this.wait();
} catch (InterruptedException e) {}
}
}
public synchronized String getOutput() {
String s = output.get();
output.clear();
return s;
}
public String getPrompt() {
return shell.getDefaultPrompt();
}
public void printInfo() throws IOException {
shell.printInfo();
}
public boolean isMasking() {
return shell.isMasking();
}
public synchronized boolean isWaitingForInput() {
return readWait;
}
public boolean isDone() {
return done;
}
}
}