smtphandler.java

java mail,java mailjava mailjava mailjava mail

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 * 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   *
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 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
 * KIND, either express or implied.  See the License for the    *
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package org.apache.james.smtpserver;

import org.apache.avalon.cornerstone.services.connection.ConnectionHandler;
import org.apache.avalon.excalibur.pool.Poolable;
import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.container.ContainerUtil;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.james.Constants;
import org.apache.james.util.CRLFTerminatedReader;
import org.apache.james.util.InternetPrintWriter;
import org.apache.james.util.watchdog.Watchdog;
import org.apache.james.util.watchdog.WatchdogTarget;
import org.apache.mailet.Mail;
import org.apache.mailet.dates.RFC822DateFormat;

import java.io.BufferedInputStream;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Random;

/**
 * Provides SMTP functionality by carrying out the server side of the SMTP
 * interaction.
 *
 * @version CVS $Revision: 494012 $ $Date: 2007-01-08 11:23:58 +0100 (Mo, 08 Jan 2007) $
 */
public class SMTPHandler
    extends AbstractLogEnabled
    implements ConnectionHandler, Poolable, SMTPSession {

    /**
     * The constants to indicate the current processing mode of the session
     */
    private final static byte COMMAND_MODE = 1;
    private final static byte RESPONSE_MODE = 2;
    private final static byte MESSAGE_RECEIVED_MODE = 3;
    private final static byte MESSAGE_ABORT_MODE = 4;

    /**
     * SMTP Server identification string used in SMTP headers
     */
    private final static String SOFTWARE_TYPE = "JAMES SMTP Server "
                                                 + Constants.SOFTWARE_VERSION;

    /**
     * Static Random instance used to generate SMTP ids
     */
    private final static Random random = new Random();

    /**
     * Static RFC822DateFormat used to generate date headers
     */
    private final static RFC822DateFormat rfc822DateFormat = new RFC822DateFormat();

    /**
     * The name of the currently parsed command
     */
    String curCommandName =  null;

    /**
     * The value of the currently parsed command
     */
    String curCommandArgument =  null;

    /**
     * The SMTPHandlerChain object set by SMTPServer
     */
    SMTPHandlerChain handlerChain = null;


    /**
     * The mode of the current session
     */
    private byte mode;

    /**
     * The MailImpl object set by the DATA command
     */
    private Mail mail = null;

    /**
     * The session termination status
     */
    private boolean sessionEnded = false;

    /**
     * The thread executing this handler
     */
    private Thread handlerThread;

    /**
     * The TCP/IP socket over which the SMTP
     * dialogue is occurring.
     */
    private Socket socket;

    /**
     * The incoming stream of bytes coming from the socket.
     */
    private InputStream in;

    /**
     * The writer to which outgoing messages are written.
     */
    private PrintWriter out;

    /**
     * A Reader wrapper for the incoming stream of bytes coming from the socket.
     */
    private CRLFTerminatedReader inReader;

    /**
     * The remote host name obtained by lookup on the socket.
     */
    private String remoteHost;

    /**
     * The remote IP address of the socket.
     */
    private String remoteIP;

    /**
     * The user name of the authenticated user associated with this SMTP transaction.
     */
    private String authenticatedUser;

    /**
     * whether or not authorization is required for this connection
     */
    private boolean authRequired;

    /**
     * whether or not this connection can relay without authentication
     */
    private boolean relayingAllowed;

    /**
     * Whether the remote Server must send HELO/EHLO 
     */
    private boolean heloEhloEnforcement;
    
    /**
     * TEMPORARY: is the sending address blocklisted
     */
    private boolean blocklisted;

    /**
     * The id associated with this particular SMTP interaction.
     */
    private String smtpID;

    /**
     * The per-service configuration data that applies to all handlers
     */
    private SMTPHandlerConfigurationData theConfigData;

    /**
     * The hash map that holds variables for the SMTP message transfer in progress.
     *
     * This hash map should only be used to store variable set in a particular
     * set of sequential MAIL-RCPT-DATA commands, as described in RFC 2821.  Per
     * connection values should be stored as member variables in this class.
     */
    private HashMap state = new HashMap();

    /**
     * The watchdog being used by this handler to deal with idle timeouts.
     */
    private Watchdog theWatchdog;

    /**
     * The watchdog target that idles out this handler.
     */
    private WatchdogTarget theWatchdogTarget = new SMTPWatchdogTarget();

    /**
     * The per-handler response buffer used to marshal responses.
     */
    private StringBuffer responseBuffer = new StringBuffer(256);

    /**
     * Set the configuration data for the handler
     *
     * @param theData the per-service configuration data for this handler
     */
    void setConfigurationData(SMTPHandlerConfigurationData theData) {
        theConfigData = theData;
    }

    /**
     * Set the Watchdog for use by this handler.
     *
     * @param theWatchdog the watchdog
     */
    void setWatchdog(Watchdog theWatchdog) {
        this.theWatchdog = theWatchdog;
    }

    /**
     * Gets the Watchdog Target that should be used by Watchdogs managing
     * this connection.
     *
     * @return the WatchdogTarget
     */
    WatchdogTarget getWatchdogTarget() {
        return theWatchdogTarget;
    }

    /**
     * Idle out this connection
     */
    void idleClose() {
        if (getLogger() != null) {
            getLogger().error("SMTP Connection has idled out.");
        }
        try {
            if (socket != null) {
                socket.close();
            }
        } catch (Exception e) {
            // ignored
        }

        synchronized (this) {
            // Interrupt the thread to recover from internal hangs
            if (handlerThread != null) {
                handlerThread.interrupt();
            }
        }
    }

    /**
     * @see org.apache.avalon.cornerstone.services.connection.ConnectionHandler#handleConnection(Socket)
     */
    public void handleConnection(Socket connection) throws IOException {

        try {
            this.socket = connection;
            synchronized (this) {
                handlerThread = Thread.currentThread();
            }
            in = new BufferedInputStream(socket.getInputStream(), 1024);
            // An ASCII encoding can be used because all transmissions other
            // that those in the DATA command are guaranteed
            // to be ASCII
            // inReader = new BufferedReader(new InputStreamReader(in, "ASCII"), 512);
            inReader = new CRLFTerminatedReader(in, "ASCII");
            remoteIP = socket.getInetAddress().getHostAddress();
            remoteHost = socket.getInetAddress().getHostName();
            smtpID = random.nextInt(1024) + "";
            relayingAllowed = theConfigData.isRelayingAllowed(remoteIP);
            authRequired = theConfigData.isAuthRequired(remoteIP);
            heloEhloEnforcement = theConfigData.useHeloEhloEnforcement();
            sessionEnded = false;
            resetState();
        } catch (Exception e) {
            StringBuffer exceptionBuffer =
                new StringBuffer(256)
                    .append("Cannot open connection from ")
                    .append(remoteHost)
                    .append(" (")
                    .append(remoteIP)
                    .append("): ")
                    .append(e.getMessage());
            String exceptionString = exceptionBuffer.toString();
            getLogger().error(exceptionString, e );
            throw new RuntimeException(exceptionString);
        }

        if (getLogger().isInfoEnabled()) {
            StringBuffer infoBuffer =
                new StringBuffer(128)
                        .append("Connection from ")
                        .append(remoteHost)
                        .append(" (")
                        .append(remoteIP)
                        .append(")");
            getLogger().info(infoBuffer.toString());
        }

        try {

            out = new InternetPrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()), 1024), false);

            // Initially greet the connector
            // Format is:  Sat, 24 Jan 1998 13:16:09 -0500

            responseBuffer.append("220 ")
                          .append(theConfigData.getHelloName())
                          .append(" SMTP Server (")
                          .append(SOFTWARE_TYPE)
                          .append(") ready ")
                          .append(rfc822DateFormat.format(new Date()));
            String responseString = clearResponseBuffer();
            writeLoggedFlushedResponse(responseString);

            //the core in-protocol handling logic
            //run all the connection handlers, if it fast fails, end the session
            //parse the command command, look up for the list of command handlers
            //Execute each of the command handlers. If any command handlers writes
            //response then, End the subsequent command handler processing and
            //start parsing new command. Once the message is received, run all
            //the message handlers. The message handlers can either terminate
            //message or terminate session

            //At the beginning
            //mode = command_mode
            //once the commandHandler writes response, the mode is changed to RESPONSE_MODE.
            //This will cause to skip the subsequent command handlers configured for that command.
            //For instance:
            //There are 2 commandhandlers MailAddressChecker and MailCmdHandler for
            //MAIL command. If MailAddressChecker validation of the MAIL FROM
            //address is successful, the MailCmdHandlers will be executed.
            //Incase it fails, it has to write response. Once we write response
            //there is no need to execute the MailCmdHandler.
            //Next, Once MAIL message is received the DataCmdHandler and any other
            //equivalent commandHandler will call setMail method. this will change
            //he mode to MAIL_RECEIVED_MODE. This mode will trigger the message
            //handlers to be execute. Message handlers can abort message. In that case,
            //message will not spooled.

            //Session started - RUN all connect handlers
            List connectHandlers = handlerChain.getConnectHandlers();
            if(connectHandlers != null) {
                int count = connectHandlers.size();
                for(int i = 0; i < count; i++) {
                    ((ConnectHandler)connectHandlers.get(i)).onConnect(this);
                    if(sessionEnded) {
                        break;
                    }
                }
            }

            theWatchdog.start();
            while(!sessionEnded) {
              //Reset the current command values
              curCommandName = null;
              curCommandArgument = null;
              mode = COMMAND_MODE;

              //parse the command
              String cmdString =  readCommandLine();
              if (cmdString == null) {
                  break;
              }
              int spaceIndex = cmdString.indexOf(" ");
              if (spaceIndex > 0) {
                  curCommandName = cmdString.substring(0, spaceIndex);
                  curCommandArgument = cmdString.substring(spaceIndex + 1);
              } else {
                  curCommandName = cmdString;
              }
              curCommandName = curCommandName.toUpperCase(Locale.US);

              //fetch the command handlers registered to the command
              List commandHandlers = handlerChain.getCommandHandlers(curCommandName);
              if(commandHandlers == null) {
                  //end the session
                  break;
              } else {
                  int count = commandHandlers.size();
                  for(int i = 0; i < count; i++) {
                      ((CommandHandler)commandHandlers.get(i)).onCommand(this);
                      theWatchdog.reset();
                      //if the response is received, stop processing of command handlers
                      if(mode != COMMAND_MODE) {