/*
* 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.log4j.net;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.regex.Pattern;
import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.Layout;
import org.apache.log4j.helpers.SyslogQuietWriter;
import org.apache.log4j.helpers.SyslogWriter;
import org.apache.log4j.spi.LoggingEvent;
// Contributors: Yves Bossel <ybossel@opengets.cl>
// Christopher Taylor <cstaylor@pacbell.net>
/**
Use SyslogAppender to send log messages to a remote syslog daemon.
@author Ceki Gülcü
@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.
/**
* Maximum length of a TAG string.
*/
private static final int MAX_TAG_LEN = 32;
/** 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 = " ";
static final Pattern NOT_ALPHANUM = Pattern.compile("[^\\p{Alnum}]");
// Have LOG_USER as default
int syslogFacility = LOG_USER;
String facilityStr;
boolean facilityPrinting = false;
//SyslogTracerPrintWriter stp;
SyslogQuietWriter sqw;
String syslogHost;
/**
* If true, the appender will generate the HEADER (timestamp and host name)
* part of the syslog packet.
* @since 1.2.15
*/
private boolean header = false;
/**
* The TAG part of the syslog message.
*
* @since 1.2.18
*/
private String tag = null;
/**
* Date format used if header = true.
* @since 1.2.15
*/
private final SimpleDateFormat dateFormat = new SimpleDateFormat("MMM dd HH:mm:ss ", Locale.ENGLISH);
/**
* Host name used to identify messages from this appender.
* @since 1.2.15
*/
private String localHostname;
/**
* Set to true after the header of the layout has been sent or if it has none.
*/
private boolean layoutHeaderChecked = false;
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;
if (sqw != null) {
try {
if (layoutHeaderChecked && layout != null && layout.getFooter() != null) {
sendLayoutMessage(layout.getFooter());
}
sqw.close();
sqw = null;
} catch(java.io.InterruptedIOException e) {
Thread.currentThread().interrupt();
sqw = null;
} catch(IOException e) {
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;
}
}
private void splitPacket(final String header, final String packet) {
int byteCount = packet.getBytes().length;
//
// if packet is less than RFC 3164 limit
// of 1024 bytes, then write it
// (must allow for up 5to 5 characters in the PRI section
// added by SyslogQuietWriter)
if (byteCount <= 1019) {
sqw.write(packet);
} else {
int split = header.length() + (packet.length() - header.length())/2;
splitPacket(header, packet.substring(0, split) + "...");
splitPacket(header, header + "..." + packet.substring(split));
}
}
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;
}
if (!layoutHeaderChecked) {
if (layout != null && layout.getHeader() != null) {
sendLayoutMessage(layout.getHeader());
}
layoutHeaderChecked = true;
}
String hdr = getPacketHeader(event.timeStamp);
String packet;
if (layout == null) {
packet = String.valueOf(event.getMessage());
} else {
packet = layout.format(event);
}
if(facilityPrinting || hdr.length() > 0) {
StringBuffer buf = new StringBuffer(hdr);
if(facilityPrinting) {
buf.append(facilityStr);
}
buf.append(packet);
packet = buf.toString();
}
sqw.setLevel(event.getLevel().getSyslogEquivalent());
//
// if message has a remote likelihood of exceeding 1024 bytes
// when encoded, consider splitting message into multiple packets
if (packet.length() > 256) {
splitPacket(hdr, packet);
} else {
sqw.write(packet);
}
if (layout == null || layout.ignoresThrowable()) {
String[] s = event.getThrowableStrRep();
if (s != null) {
for(int i = 0; i < s.length; i++) {
if (s[i].startsWith("\t")) {
sqw.write(hdr+TAB+s[i].substring(1));
} else {
sqw.write(hdr+s[i]);
}
}
}
}
}
/**
This method returns immediately as options are activated when they
are set.
*/
public
void activateOptions() {
if (header) {
getLocalHostname();
}
if (layout != null && layout.getHeader() != null) {
sendLayoutMessage(layout.getHeader());
}
layoutHeaderChecked = true;
}
/**
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. A non-default port can be specified by
appending a colon and port number to a host name,
an IPv4 address or an IPv6 address enclosed in square brackets.
<b>WARNING</b> If the SyslogHost is not set, then this appender
will fail.
*/
public
void setSyslogHost(final 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;
}
/**
* If true, the appender will generate the HEADER part (that is, timestamp and host name)
* of the syslog packet. Default value is false for compatibility with existing behavior,
* however should be true unless there is a specific justification.
* @since 1.2.15
*/
public final boolean getHeader() {
return header;
}
/**
* Returns whether the appender produces the HEADER part (that is, timestamp and host name)
* of the syslog packet.
* @since 1.2.15
*/
public final void setHeader(final boolean val) {
header = val;
}
/**
* Sets the <b>Tag</b> option.
*
* <p>
* If non-{@code null}, the printed HEADER will include the specified tag followed by a colon. If {@code null}, then no tag is printed.
* </p>
* <p>
* The default value is {@code null}.
* </p>
*
* @param tag
* the TAG to be printed out with the header
* @see #getTag()
* @since 1.2.18
*/
public void setTag(final String tag) {
String newTag = tag;
if (newTag != null) {
if (newTag.length() > MAX_TAG_LEN) {
newTag = newTag.substring(0, MAX_TAG_LEN);
}
if (NOT_ALPHANUM.matcher(newTag).find()) {
throw new IllegalArgumentException("tag contains non-alphanumeric characters");
}
}
this.tag = newTag;
}
/**
* Gets the TAG to be printed with the HEADER portion of the log message. This will return {@code null} if no TAG is to be printed.
* <p>
* The default value is {@code null}.
* </p>
*
* @return the TAG, max length 32.
* @see #setTag(String)
* @since 1.2.18
*/
public String getTag() {
return this.tag;
}
/**
* Get the host name used to identify this appender.
* @return local host name
* @since 1.2.15
*/
private String getLocalHostname() {
if (localHostname == null) {
try {
InetAddress addr = InetAddress.getLocalHost();
localHostname = addr.getHostName();
} catch (UnknownHostException uhe) {
localHostname = "UNKNOWN_HOST";
}
}
return localHostname;
}
/**
* Gets HEADER portion of packet.
* @param timeStamp number of milliseconds after the standard base time.
* @return HEADER portion of packet, will be zero-length string if header is false.
* @since 1.2.15
*/
private String getPacketHeader(final long timeStamp) {
if (header) {
StringBuffer buf = new StringBuffer(dateFormat.format(new Date(timeStamp)));
// RFC 3164 says leading space, not leading zero on days 1-9
if (buf.charAt(4) == '0') {
buf.setCharAt(4, ' ');
}
buf.append(getLocalHostname());
buf.append(' ');
if(this.tag != null) {
buf.append(this.tag);
buf.append(": ");
}
return buf.toString();
}
return "";
}
/**
* Set header or footer of layout.
* @param msg message body, may not be null.
*/
private void sendLayoutMessage(final String msg) {
if (sqw != null) {
String packet = msg;
String hdr = getPacketHeader(new Date().getTime());
if(facilityPrinting || hdr.length() > 0) {
StringBuffer buf = new StringBuffer(hdr);
if(facilityPrinting) {
buf.append(facilityStr);
}
buf.append(msg);
packet = buf.toString();
}
sqw.setLevel(6);
sqw.write(packet);
}
}
}