org.pircbotx.IdentServer Maven / Gradle / Ivy
/**
* Copyright (C) 2010-2013 Leon Blakey
*
* This file is part of PircBotX.
*
* PircBotX is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* PircBotX is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with PircBotX. If not, see
* Most IRC servers attempt to contact the ident server on connecting
* hosts in order to determine the user's identity. A few IRC servers
* will not allow you to connect unless this information is provided.
*
* So when a PircBotX is run on a machine that does not run an ident server,
* it may be necessary to provide a "faked" response by starting up its
* own ident server and sending out apparently correct responses.
*
* @since PircBot 0.9c
* @author Leon Blakey
*/
@Slf4j
public class IdentServer implements Closeable, Runnable {
protected static final int PORT = 113;
@Setter(AccessLevel.PROTECTED)
@Getter(AccessLevel.PROTECTED)
protected static IdentServer server;
protected static final Object INSTANCE_CREATE_LOCK = new Object();
protected final Charset encoding;
protected final ServerSocket serverSocket;
protected final List identEntries = new ArrayList();
protected Thread runningThread;
/**
* Start the ident server with the systems default charset.
* @see Charset#defaultCharset()
*/
public static void startServer() {
startServer(Charset.defaultCharset());
}
/**
* Start the ident server with the specified charset.
* @param encoding The encoding to use for connections
*/
@Synchronized("INSTANCE_CREATE_LOCK")
public static void startServer(Charset encoding) {
if (server != null)
throw new RuntimeException("Already created an IdentServer instance");
server = new IdentServer(encoding);
server.start();
}
/**
* Stop the server and clear pending ident responses.
* @throws IOException
*/
@Synchronized("INSTANCE_CREATE_LOCK")
public static void stopServer() throws IOException {
if (server == null)
throw new RuntimeException("Never created an IdentServer");
server.close();
server = null;
}
/**
* Create an ident server on port 113 with the specified encoding
* @param encoding Encoding to use for sockets
*/
protected IdentServer(Charset encoding) {
try {
this.encoding = encoding;
this.serverSocket = new ServerSocket(PORT);
} catch (Exception e) {
throw new RuntimeException("Could not create server socket for IdentServer on port " + PORT, e);
}
}
/**
* Start the ident server in a new thread.
*/
public void start() {
runningThread = new Thread(this);
runningThread.setName("IdentServer");
runningThread.start();
}
/**
* Waits for a client to connect to the ident server before making an
* appropriate response.
*/
public void run() {
try {
log.info("IdentServer running on port " + PORT);
while (true)
handleNextConnection();
} catch (Exception e) {
log.error("Exception encountered when running IdentServer", e);
} finally {
try {
close();
} catch (IOException e) {
log.error("Cannot close IdentServer socket", e);
}
}
}
/**
* Wait for and process the next connection.
* @throws IOException If any error occurred during reading or writing
*/
public void handleNextConnection() throws IOException {
//Grab next connectin
Socket socket = serverSocket.accept();
BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream(), encoding));
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(), encoding));
InetSocketAddress remoteAddress = (InetSocketAddress) socket.getRemoteSocketAddress();
//Get and validate Ident from server
String line = reader.readLine();
if (StringUtils.isBlank(line)) {
log.error("Ignoring connection from " + remoteAddress + ", received blank line");
socket.close();
return;
}
String[] parsedLine = StringUtils.split(line, ", ");
if (parsedLine.length != 2) {
log.error("Ignoring connection from " + remoteAddress + ", recieved unknown line: " + line);
socket.close();
return;
}
int localPort = Utils.tryParseInt(parsedLine[0], -1);
int remotePort = Utils.tryParseInt(parsedLine[1], -1);
if (localPort == -1 || remotePort == -1) {
log.error("Ignoring connection from " + remoteAddress + ", recieved unparsable line: " + line);
socket.close();
return;
}
//Grab the IdentEntry for this ident
log.debug("Received ident request from " + remoteAddress + ": " + line);
IdentEntry identEntry = null;
synchronized (identEntries) {
for (IdentEntry curIdentEntry : identEntries)
if (curIdentEntry.getRemoteAddress().equals(remoteAddress.getAddress())
&& curIdentEntry.getRemotePort() == remotePort
&& curIdentEntry.getLocalPort() == localPort) {
identEntry = curIdentEntry;
break;
}
}
if (identEntry == null) {
String response = localPort + ", " + remotePort + " ERROR : NO-USER";
log.error("Unknown ident " + line + " from " + remoteAddress + ", responding with: " + response);
writer.write(line + "\r\n");
writer.flush();
socket.close();
return;
}
//Respond to correct ident entry with login
String response = line + " : USERID : UNIX : " + identEntry.getLogin();
log.debug("Responded to ident request from " + remoteAddress + " with: " + response);
writer.write(line + "\r\n");
writer.flush();
socket.close();
}
protected void addIdentEntry(InetAddress remoteAddress, int remotePort, int localPort, String login) {
synchronized (identEntries) {
identEntries.add(new IdentEntry(remoteAddress, remotePort, localPort, login));
}
}
/**
* Close the server socket and clear pending ident responses.
* @throws IOException If an error occured during closing
*/
@Synchronized("INSTANCE_CREATE_LOCK")
public void close() throws IOException {
serverSocket.close();
identEntries.clear();
log.info("Closed ident server on port " + PORT);
}
@Data
protected static class IdentEntry {
protected final InetAddress remoteAddress;
protected final int remotePort;
protected final int localPort;
protected final String login;
}
}