src/java/org/apache/log4j/net/SyslogAppender.java

/*
 * Copyright (C) The Apache Software Foundation. All rights reserved.
 *
 * This software is published under the terms of the Apache Software
 * License version 1.1, a copy of which has been included with this
 * distribution in the LICENSE.txt file.  */

package org.apache.log4j.net;

import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.spi.LoggingEvent;
import org.apache.log4j.Layout;
import org.apache.log4j.helpers.SyslogWriter;
import org.apache.log4j.helpers.SyslogQuietWriter;

// Contributors: Yves Bossel <ybossel@opengets.cl>
//               Christopher Taylor <cstaylor@pacbell.net>

/**
    Use SyslogAppender to send log messages to a remote syslog daemon.

    @author Ceki G&uuml;lc&uuml;
    @author Anders Kristensen
 */
public class SyslogAppender extends AppenderSkeleton {
  // The following constants are extracted from a syslog.h file
  // copyrighted by the Regents of the University of California
  // I hope nobody at Berkley gets offended.

  /** Kernel messages */
  final static public int LOG_KERN     = 0;
  /** Random user-level messages */
  final static public int LOG_USER     = 1<<3;
  /** Mail system */
  final static public int LOG_MAIL     = 2<<3;
  /** System daemons */
  final static public int LOG_DAEMON   = 3<<3;
  /** security/authorization messages */
  final static public int LOG_AUTH     = 4<<3;
  /** messages generated internally by syslogd */
  final static public int LOG_SYSLOG   = 5<<3;

  /** line printer subsystem */
  final static public int LOG_LPR      = 6<<3;
  /** network news subsystem */
  final static public int LOG_NEWS     = 7<<3;
  /** UUCP subsystem */
  final static public int LOG_UUCP     = 8<<3;
  /** clock daemon */
  final static public int LOG_CRON     = 9<<3;
  /** security/authorization  messages (private) */
  final static public int LOG_AUTHPRIV = 10<<3;
  /** ftp daemon */
  final static public int LOG_FTP      = 11<<3;

  // other codes through 15 reserved for system use
  /** reserved for local use */
  final static public int LOG_LOCAL0 = 16<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL1 = 17<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL2 = 18<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL3 = 19<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL4 = 20<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL5 = 21<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL6 = 22<<3;
  /** reserved for local use*/
  final static public int LOG_LOCAL7 = 23<<3;

  protected static final int SYSLOG_HOST_OI = 0;
  protected static final int FACILITY_OI = 1;

  static final String TAB = "    ";

  // Have LOG_USER as default
  int syslogFacility = LOG_USER;
  String facilityStr;
  boolean facilityPrinting = false;

  //SyslogTracerPrintWriter stp;
  SyslogQuietWriter sqw;
  String syslogHost;

  public
  SyslogAppender() {
    this.initSyslogFacilityStr();
  }

  public
  SyslogAppender(Layout layout, int syslogFacility) {
    this.layout = layout;
    this.syslogFacility = syslogFacility;
    this.initSyslogFacilityStr();
  }

  public
  SyslogAppender(Layout layout, String syslogHost, int syslogFacility) {
    this(layout, syslogFacility);
    setSyslogHost(syslogHost);
  }

  /**
     Release any resources held by this SyslogAppender.

     @since 0.8.4
   */
  synchronized
  public
  void close() {
    closed = true;
    // A SyslogWriter is UDP based and needs no opening. Hence, it
    // can't be closed. We just unset the variables here.
    sqw = null;
  }

  private
  void initSyslogFacilityStr() {
    facilityStr = getFacilityString(this.syslogFacility);

    if (facilityStr == null) {
      System.err.println("\"" + syslogFacility +
                  "\" is an unknown syslog facility. Defaulting to \"USER\".");
      this.syslogFacility = LOG_USER;
      facilityStr = "user:";
    } else {
      facilityStr += ":";
    }
  }

  /**
     Returns the specified syslog facility as a lower-case String,
     e.g. "kern", "user", etc.
  */
  public
  static
  String getFacilityString(int syslogFacility) {
    switch(syslogFacility) {
    case LOG_KERN:      return "kern";
    case LOG_USER:      return "user";
    case LOG_MAIL:      return "mail";
    case LOG_DAEMON:    return "daemon";
    case LOG_AUTH:      return "auth";
    case LOG_SYSLOG:    return "syslog";
    case LOG_LPR:       return "lpr";
    case LOG_NEWS:      return "news";
    case LOG_UUCP:      return "uucp";
    case LOG_CRON:      return "cron";
    case LOG_AUTHPRIV:  return "authpriv";
    case LOG_FTP:       return "ftp";
    case LOG_LOCAL0:    return "local0";
    case LOG_LOCAL1:    return "local1";
    case LOG_LOCAL2:    return "local2";
    case LOG_LOCAL3:    return "local3";
    case LOG_LOCAL4:    return "local4";
    case LOG_LOCAL5:    return "local5";
    case LOG_LOCAL6:    return "local6";
    case LOG_LOCAL7:    return "local7";
    default:            return null;
    }
  }

  /**
     Returns the integer value corresponding to the named syslog
     facility, or -1 if it couldn't be recognized.

     @param facilityName one of the strings KERN, USER, MAIL, DAEMON,
            AUTH, SYSLOG, LPR, NEWS, UUCP, CRON, AUTHPRIV, FTP, LOCAL0,
            LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7.
            The matching is case-insensitive.

     @since 1.1
  */
  public
  static
  int getFacility(String facilityName) {
    if(facilityName != null) {
      facilityName = facilityName.trim();
    }
    if("KERN".equalsIgnoreCase(facilityName)) {
      return LOG_KERN;
    } else if("USER".equalsIgnoreCase(facilityName)) {
      return LOG_USER;
    } else if("MAIL".equalsIgnoreCase(facilityName)) {
      return LOG_MAIL;
    } else if("DAEMON".equalsIgnoreCase(facilityName)) {
      return LOG_DAEMON;
    } else if("AUTH".equalsIgnoreCase(facilityName)) {
      return LOG_AUTH;
    } else if("SYSLOG".equalsIgnoreCase(facilityName)) {
      return LOG_SYSLOG;
    } else if("LPR".equalsIgnoreCase(facilityName)) {
      return LOG_LPR;
    } else if("NEWS".equalsIgnoreCase(facilityName)) {
      return LOG_NEWS;
    } else if("UUCP".equalsIgnoreCase(facilityName)) {
      return LOG_UUCP;
    } else if("CRON".equalsIgnoreCase(facilityName)) {
      return LOG_CRON;
    } else if("AUTHPRIV".equalsIgnoreCase(facilityName)) {
      return LOG_AUTHPRIV;
    } else if("FTP".equalsIgnoreCase(facilityName)) {
      return LOG_FTP;
    } else if("LOCAL0".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL0;
    } else if("LOCAL1".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL1;
    } else if("LOCAL2".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL2;
    } else if("LOCAL3".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL3;
    } else if("LOCAL4".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL4;
    } else if("LOCAL5".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL5;
    } else if("LOCAL6".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL6;
    } else if("LOCAL7".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL7;
    } else {
      return -1;
    }
  }

  public
  void append(LoggingEvent event) {

    if(!isAsSevereAsThreshold(event.getLevel()))
      return;

    // We must not attempt to append if sqw is null.
    if(sqw == null) {
      errorHandler.error("No syslog host is set for SyslogAppedender named \""+
			this.name+"\".");
      return;
    }

    String buffer = (facilityPrinting? facilityStr : "") +
                          layout.format(event);

    sqw.setLevel(event.getLevel().getSyslogEquivalent());
    sqw.write(buffer);

    String[] s = event.getThrowableStrRep();
    if (s != null) {
      int len = s.length;
      if(len > 0) {
	sqw.write(s[0]);

	for(int i = 1; i < len; i++) {
	    sqw.write(TAB+s[i].substring(1));
	}
      }

    }
  }

  /**
     This method returns immediately as options are activated when they
     are set.
  */
  public
  void activateOptions() {
  }

  /**
     The SyslogAppender requires a layout. Hence, this method returns
     <code>true</code>.

     @since 0.8.4 */
  public
  boolean requiresLayout() {
    return true;
  }

  /**
    The <b>SyslogHost</b> option is the name of the the syslog host
    where log output should go.

    <b>WARNING</b> If the SyslogHost is not set, then this appender
    will fail.
   */
  public
  void setSyslogHost(String syslogHost) {
    this.sqw = new SyslogQuietWriter(new SyslogWriter(syslogHost),
				     syslogFacility, errorHandler);
    //this.stp = new SyslogTracerPrintWriter(sqw);
    this.syslogHost = syslogHost;
  }

  /**
     Returns the value of the <b>SyslogHost</b> option.
   */
  public
  String getSyslogHost() {
    return syslogHost;
  }

  /**
     Set the syslog facility. This is the <b>Facility</b> option.

     <p>The <code>facilityName</code> parameter must be one of the
     strings KERN, USER, MAIL, DAEMON, AUTH, SYSLOG, LPR, NEWS, UUCP,
     CRON, AUTHPRIV, FTP, LOCAL0, LOCAL1, LOCAL2, LOCAL3, LOCAL4,
     LOCAL5, LOCAL6, LOCAL7. Case is unimportant.

     @since 0.8.1 */
  public
  void setFacility(String facilityName) {
    if(facilityName == null)
      return;

    syslogFacility = getFacility(facilityName);
    if (syslogFacility == -1) {
      System.err.println("["+facilityName +
                  "] is an unknown syslog facility. Defaulting to [USER].");
      syslogFacility = LOG_USER;
    }

    this.initSyslogFacilityStr();

    // If there is already a sqw, make it use the new facility.
    if(sqw != null) {
      sqw.setSyslogFacility(this.syslogFacility);
    }
  }

  /**
     Returns the value of the <b>Facility</b> option.
   */
  public
  String getFacility() {
    return getFacilityString(syslogFacility);
  }

  /**
    If the <b>FacilityPrinting</b> option is set to true, the printed
    message will include the facility name of the application. It is
    <em>false</em> by default.
   */
  public
  void setFacilityPrinting(boolean on) {
    facilityPrinting = on;
  }

  /**
     Returns the value of the <b>FacilityPrinting</b> option.
   */
  public
  boolean getFacilityPrinting() {
    return facilityPrinting;
  }
}