clamavscan.java

java mail,java mailjava mailjava mailjava mail

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package org.apache.james.transport.mailets;

import org.apache.mailet.RFC2822Headers;
import org.apache.mailet.GenericMailet;
import org.apache.mailet.Mail;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.ConnectException;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;


/**
 * <P>Does an antivirus scan check using a ClamAV daemon (CLAMD)</P>
 * 
 * <P> Interacts directly with the daemon using the "stream" method,
 * which should have the lowest possible overhead.</P>
 * <P>The CLAMD daemon will typically reside on <I>localhost</I>, but could reside on a
 * different host.
 * It may also consist on a set of multiple daemons, each residing on a different
 * server and on different IP number.
 * In such case a DNS host name with multiple IP addresses (round-robin load sharing)
 * is supported by the mailet (but on the same port number).</P>
 * 
 * <P>Handles the following init parameters:</P>
 * <UL>
 *    <LI><CODE>&lt;debug&gt;</CODE>.</LI>
 *    <LI><CODE>&lt;host&gt;</CODE>: the host name of the server where CLAMD runs. It can either be
 *        a machine name, such as
 *        "<code>java.sun.com</code>", or a textual representation of its
 *        IP address. If a literal IP address is supplied, only the
 *        validity of the address format is checked.
 *        If the machine name resolves to multiple IP addresses, <I>round-robin load sharing</I> will
 *        be used.
 *        The default is <CODE>localhost</CODE>.</LI>
 *    <LI><CODE>&lt;port&gt;</CODE>: the port on which CLAMD listens. The default is <I>3310</I>.</LI>
 *    <LI><CODE>&lt;maxPings&gt;</CODE>: the maximum number of connection retries during startup.
 *        If the value is <I>0</I> no startup test will be done.
 *        The default is <I>6</I>.</LI>
 *    <LI><CODE>&lt;pingIntervalMilli&gt;</CODE>: the interval (in milliseconds)
 *        between each connection retry during startup.
 *        The default is <I>30000</I> (30 seconds).</LI>
 *    <LI><CODE>&lt;streamBufferSize&gt;</CODE>: the BufferedOutputStream buffer size to use 
 *        writing to the <I>stream connection</I>. The default is <I>8192</I>.</LI>
 * </UL>
 * 
 * <P>The actions performed are as follows:</P>
 * <UL>
 *    <LI>During initialization:</LI>
 *    <OL>
 *        <LI>Gets all <CODE>config.xml</CODE> parameters, handling the defaults;</LI>
 *        <LI>resolves the <CODE>&lt;host&gt;</CODE> parameter, creating the round-robin IP list;</LI>
 *        <LI>connects to CLAMD at the first IP in the round-robin list, on
 *            the specified <CODE>&lt;port&gt;</CODE>;</LI>
 *        <LI>if unsuccessful, retries every <CODE>&lt;pingIntervalMilli&gt;</CODE> milliseconds up to
 *            <CODE>&lt;maxPings&gt;</CODE> times;</LI>
 *        <LI>sends a <CODE>PING</CODE> request;</LI>
 *        <LI>waits for a <CODE>PONG</CODE> answer;</LI>
 *        <LI>repeats steps 3-6 for every other IP resolved.
 *    </OL>
 *    <LI>For every mail</LI>
 *    <OL>
 *        <LI>connects to CLAMD at the "next" IP in the round-robin list, on
 *            the specified <CODE>&lt;port&gt;</CODE>, and increments the "next" index;
 *            if the connection request is not accepted tries with the next one
 *            in the list unless all of them have failed;</LI>
 *        <LI>sends a "<CODE>STREAM</CODE>" request;</LI>
 *        <LI>parses the "<CODE>PORT <I>streamPort</I></CODE>" answer obtaining the port number;</LI>
 *        <LI>makes a second connection (the <I>stream connection</I>) to CLAMD at the same host (or IP)
 *            on the <I>streamPort</I> just obtained;</LI>
 *        <LI>sends the mime message to CLAMD (using {@link MimeMessage#writeTo(OutputStream)})
 *            through the <I>stream connection</I>;</LI>
 *        <LI>closes the <I>stream connection</I>;</LI>
 *        <LI>gets the "<CODE>OK</CODE>" or "<CODE>... FOUND</CODE>" answer from the main connection;</LI>
 *        <LI>closes the main connection;</LI>
 *        <LI>sets the "<CODE>org.apache.james.infected</CODE>" <I>mail attribute</I> to either
 *            "<CODE>true</CODE>" or "<CODE>false</CODE>";</LI>
 *        <LI>adds the "<CODE>X-MessageIsInfected</CODE>" <I>header</I> to either
 *            "<CODE>true</CODE>" or "<CODE>false</CODE>";</LI>
 *    </OL>
 * </UL>
 * 
 * <P>Some notes regarding <a href="http://www.clamav.net/">clamav.conf</a>:</p>
 * <UL>
 *    <LI><CODE>LocalSocket</CODE> must be commented out</LI>
 *    <LI><CODE>TCPSocket</CODE> must be set to a port# (typically 3310)</LI>
 *    <LI><CODE>StreamMaxLength</CODE> must be &gt;= the James config.xml parameter
 *    &lt;<CODE>maxmessagesize</CODE>&gt; in SMTP &lt;<CODE>handler</CODE>&gt;</LI>
 *    <LI><CODE>MaxThreads</CODE> should? be &gt;= the James config.xml parameter
 *    &lt;<CODE>threads</CODE>&gt; in &lt;<CODE>spoolmanager</CODE>&gt;</LI>
 *    <LI><CODE>ScanMail</CODE> must be uncommented</LI>
 * </UL>
 *
 * <P>Here follows an example of config.xml definitions deploying CLAMD on localhost,
 * and handling the infected messages:</P>
 * <PRE><CODE>
 *
 * ...
 *
 *    &lt;!-- Do an antivirus scan --&gt;
 *    &lt;mailet match="All" class="ClamAVScan" onMailetException="ignore"/&gt;
 *
 *    &lt;!-- If infected go to virus processor --&gt;
 *    &lt;mailet match="HasMailAttributeWithValue=org.apache.james.infected, true" class="ToProcessor"&gt;
 *       &lt;processor&gt; virus &lt;/processor&gt;
 *    &lt;/mailet&gt;
 *
 *    &lt;!-- Check attachment extensions for possible viruses --&gt;
 *    &lt;mailet match="AttachmentFileNameIs=-d -z *.exe *.com *.bat *.cmd *.pif *.scr *.vbs *.avi *.mp3 *.mpeg *.shs" class="ToProcessor"&gt;
 *       &lt;processor&gt; bad-extensions &lt;/processor&gt;
 *    &lt;/mailet&gt;
 *
 * ...
 *
 * &lt;!-- Messages containing viruses --&gt;
 * &lt;processor name="virus"&gt;
 *
 *    &lt;!-- To avoid a loop while bouncing --&gt;
 *    &lt;mailet match="All" class="SetMailAttribute"&gt;
 *       &lt;org.apache.james.infected&gt;true, bouncing&lt;/org.apache.james.infected&gt;
 *    &lt;/mailet&gt;
 *
 *    &lt;mailet match="SMTPAuthSuccessful" class="Bounce"&gt;
 *       &lt;sender&gt;[e-mail]&lt;/sender&gt;
 *       &lt;inline&gt;heads&lt;/inline&gt;
 *       &lt;attachment&gt;none&lt;/attachment&gt;
 *       &lt;notice&gt; Warning: We were unable to deliver the message below because it was found infected by virus(es). &lt;/notice&gt;
 *    &lt;/mailet&gt;
 *
 *    &lt;!--
 *    &lt;mailet match="All" class="ToRepository"&gt;
 *       &lt;repositoryPath&gt;file://var/mail/infected/&lt;/repositoryPath&gt;
 *    &lt;/mailet&gt;
 *    --&gt;
 *
 *    &lt;mailet match="All" class="Null" /&gt;
 * &lt;/processor&gt;
 * </CODE></PRE>
 *
 * @version 2.2.1
 * @since 2.2.1
 * @see <a href="http://www.clamav.net/">ClamAV Home Page</a>
 * @see <a href="http://www.sosdg.org/clamav-win32/">ClamAV For Windows</a>
 */
public class ClamAVScan extends GenericMailet {
    
    private static final int DEFAULT_PORT = 3310;
    
    private static final int DEFAULT_MAX_PINGS = 6;
    
    private static final int DEFAULT_PING_INTERVAL_MILLI = 30000;
    
    private static final int DEFAULT_STREAM_BUFFER_SIZE = 8192;
    
    private static final int DEFAULT_CONNECTION_TIMEOUT = 20000;

    private static final String STREAM_PORT_STRING = "PORT ";
    
    private static final String FOUND_STRING = "FOUND";
    
    private static final String MAIL_ATTRIBUTE_NAME = "org.apache.james.infected";
    
    private static final String HEADER_NAME = "X-MessageIsInfected";
    
    /**
     * Holds value of property debug.
     */
    private boolean debug;
    
    /**
     * Holds value of property host.
     */
    private String host;
    
    /**
     * Holds value of property port.
     */
    private int port;
    
    /**
     * Holds value of property maxPings.
     */
    private int maxPings;
    
    /**
     * Holds value of property pingIntervalMilli.
     */
    private int pingIntervalMilli;
    
    /**
     * Holds value of property streamBufferSize.
     */
    private int streamBufferSize;

    /**
     * Holds value of property addresses.
     */
    private InetAddress[] addresses;
    
    /**
     * Holds the index of the next address to connect to
     */
    private int nextAddressIndex;

    /**
     * Return a string describing this mailet.
     *
     * @return a string describing this mailet
     */
    public String getMailetInfo() {
        return "Antivirus Check using ClamAV (CLAMD)";
    }
    
    /** Gets the expected init parameters. */
    protected  String[] getAllowedInitParameters() {
        String[] allowedArray = {
            //            "static",
            "debug",
                    "host",
                    "port",
                    "maxPings",
                    "pingIntervalMilli",
                    "streamBufferSize"
        };
        return allowedArray;
    }
    
    /**
     * Initializer for property debug.
     */
    protected void initDebug() {
        String debugParam = getInitParameter("debug");
        setDebug((debugParam == null) ? false : new Boolean(debugParam).booleanValue());
    }
    
    /**
     * Getter for property debug.
     * @return Value of property debug.
     */
    public boolean isDebug() {
        return this.debug;
    }
    
    /**
     * Setter for property debug.
     * @param debug New value of property debug.
     */
    public void setDebug(boolean debug) {
        this.debug = debug;
    }
    
    /**
     * Initializer for property host.
     * @throws UnknownHostException if unable to resolve the host name, or if invalid
     */
    protected void initHost() throws UnknownHostException {
        setHost(getInitParameter("host"));
        if (isDebug()) {
            log("host: " + getHost());
        }
    }
    
    /**
     * Getter for property host.
     * @return Value of property host.
     */
    public String getHost() {
        
        return this.host;
    }
    
    /**
     * Setter for property host.
     * Resolves also the host name into the corresponding IP addresses, issues
     * a {@link #setAddresses} and resets the <CODE>nextAddressIndex</CODE>
     * variable to <I>0</I> for dealing with <I>round-robin</I>.
     * @param host New value of property host.
     * @throws UnknownHostException if unable to resolve the host name, or if invalid
     */
    public void setHost(String host) throws UnknownHostException {
        
        this.host = host;