001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.core.net;
015
016import java.io.IOException;
017import java.io.OutputStream;
018import java.net.SocketException;
019import java.net.UnknownHostException;
020import java.nio.charset.Charset;
021
022import ch.qos.logback.core.AppenderBase;
023import ch.qos.logback.core.CoreConstants;
024import ch.qos.logback.core.Layout;
025
026/**
027 * Base class for SyslogAppender.
028 * 
029 * @author Ceki Gülcü
030 * 
031 * @param <E>
032 */
033public abstract class SyslogAppenderBase<E> extends AppenderBase<E> {
034
035    final static String SYSLOG_LAYOUT_URL = CoreConstants.CODES_URL + "#syslog_layout";
036    final static int MAX_MESSAGE_SIZE_LIMIT = 65000;
037
038    Layout<E> layout;
039    String facilityStr;
040    String syslogHost;
041    protected String suffixPattern;
042    SyslogOutputStream sos;
043    int port = SyslogConstants.SYSLOG_PORT;
044    int maxMessageSize;
045    Charset charset;
046
047    public void start() {
048        int errorCount = 0;
049        if (facilityStr == null) {
050            addError("The Facility option is mandatory");
051            errorCount++;
052        }
053
054        if (charset == null) {
055            // Using defaultCharset() preserves the previous behavior when String.getBytes()
056            // was
057            // called without arguments
058            charset = Charset.defaultCharset();
059        }
060
061        try {
062            sos = createOutputStream();
063
064            final int systemDatagramSize = sos.getSendBufferSize();
065            if (maxMessageSize == 0) {
066                maxMessageSize = Math.min(systemDatagramSize, MAX_MESSAGE_SIZE_LIMIT);
067                addInfo("Defaulting maxMessageSize to [" + maxMessageSize + "]");
068            } else if (maxMessageSize > systemDatagramSize) {
069                addWarn("maxMessageSize of [" + maxMessageSize
070                        + "] is larger than the system defined datagram size of [" + systemDatagramSize + "].");
071                addWarn("This may result in dropped logs.");
072            }
073        } catch (UnknownHostException e) {
074            addError("Could not create SyslogWriter", e);
075            errorCount++;
076        } catch (SocketException e) {
077            addWarn("Failed to bind to a random datagram socket. Will try to reconnect later.", e);
078        }
079
080        if (layout == null) {
081            layout = buildLayout();
082        }
083
084        if (errorCount == 0) {
085            super.start();
086        }
087    }
088
089    abstract public SyslogOutputStream createOutputStream() throws UnknownHostException, SocketException;
090
091    abstract public Layout<E> buildLayout();
092
093    abstract public int getSeverityForEvent(Object eventObject);
094
095    @Override
096    protected void append(E eventObject) {
097        if (!isStarted()) {
098            return;
099        }
100
101        try {
102            String msg = layout.doLayout(eventObject);
103            if (msg == null) {
104                return;
105            }
106            if (msg.length() > maxMessageSize) {
107                msg = msg.substring(0, maxMessageSize);
108            }
109            sos.write(msg.getBytes(charset));
110            sos.flush();
111            postProcess(eventObject, sos);
112        } catch (IOException ioe) {
113            addError("Failed to send diagram to " + syslogHost, ioe);
114        }
115    }
116
117    protected void postProcess(Object event, OutputStream sw) {
118
119    }
120
121    /**
122     * Returns the integer value corresponding to the named syslog facility.
123     * 
124     * @throws IllegalArgumentException if the facility string is not recognized
125     */
126    static public int facilityStringToint(String facilityStr) {
127        if ("KERN".equalsIgnoreCase(facilityStr)) {
128            return SyslogConstants.LOG_KERN;
129        } else if ("USER".equalsIgnoreCase(facilityStr)) {
130            return SyslogConstants.LOG_USER;
131        } else if ("MAIL".equalsIgnoreCase(facilityStr)) {
132            return SyslogConstants.LOG_MAIL;
133        } else if ("DAEMON".equalsIgnoreCase(facilityStr)) {
134            return SyslogConstants.LOG_DAEMON;
135        } else if ("AUTH".equalsIgnoreCase(facilityStr)) {
136            return SyslogConstants.LOG_AUTH;
137        } else if ("SYSLOG".equalsIgnoreCase(facilityStr)) {
138            return SyslogConstants.LOG_SYSLOG;
139        } else if ("LPR".equalsIgnoreCase(facilityStr)) {
140            return SyslogConstants.LOG_LPR;
141        } else if ("NEWS".equalsIgnoreCase(facilityStr)) {
142            return SyslogConstants.LOG_NEWS;
143        } else if ("UUCP".equalsIgnoreCase(facilityStr)) {
144            return SyslogConstants.LOG_UUCP;
145        } else if ("CRON".equalsIgnoreCase(facilityStr)) {
146            return SyslogConstants.LOG_CRON;
147        } else if ("AUTHPRIV".equalsIgnoreCase(facilityStr)) {
148            return SyslogConstants.LOG_AUTHPRIV;
149        } else if ("FTP".equalsIgnoreCase(facilityStr)) {
150            return SyslogConstants.LOG_FTP;
151        } else if ("NTP".equalsIgnoreCase(facilityStr)) {
152            return SyslogConstants.LOG_NTP;
153        } else if ("AUDIT".equalsIgnoreCase(facilityStr)) {
154            return SyslogConstants.LOG_AUDIT;
155        } else if ("ALERT".equalsIgnoreCase(facilityStr)) {
156            return SyslogConstants.LOG_ALERT;
157        } else if ("CLOCK".equalsIgnoreCase(facilityStr)) {
158            return SyslogConstants.LOG_CLOCK;
159        } else if ("LOCAL0".equalsIgnoreCase(facilityStr)) {
160            return SyslogConstants.LOG_LOCAL0;
161        } else if ("LOCAL1".equalsIgnoreCase(facilityStr)) {
162            return SyslogConstants.LOG_LOCAL1;
163        } else if ("LOCAL2".equalsIgnoreCase(facilityStr)) {
164            return SyslogConstants.LOG_LOCAL2;
165        } else if ("LOCAL3".equalsIgnoreCase(facilityStr)) {
166            return SyslogConstants.LOG_LOCAL3;
167        } else if ("LOCAL4".equalsIgnoreCase(facilityStr)) {
168            return SyslogConstants.LOG_LOCAL4;
169        } else if ("LOCAL5".equalsIgnoreCase(facilityStr)) {
170            return SyslogConstants.LOG_LOCAL5;
171        } else if ("LOCAL6".equalsIgnoreCase(facilityStr)) {
172            return SyslogConstants.LOG_LOCAL6;
173        } else if ("LOCAL7".equalsIgnoreCase(facilityStr)) {
174            return SyslogConstants.LOG_LOCAL7;
175        } else {
176            throw new IllegalArgumentException(facilityStr + " is not a valid syslog facility string");
177        }
178    }
179
180    /**
181     * Returns the value of the <b>SyslogHost</b> option.
182     */
183    public String getSyslogHost() {
184        return syslogHost;
185    }
186
187    /**
188     * The <b>SyslogHost</b> option is the name of the syslog host where log
189     * output should go.
190     * 
191     * <b>WARNING</b> If the SyslogHost is not set, then this appender will fail.
192     */
193    public void setSyslogHost(String syslogHost) {
194        this.syslogHost = syslogHost;
195    }
196
197    /**
198     * Returns the string value of the <b>Facility</b> option.
199     * 
200     * See {@link #setFacility} for the set of allowed values.
201     */
202    public String getFacility() {
203        return facilityStr;
204    }
205
206    /**
207     * The <b>Facility</b> option must be set one of the strings KERN, USER, MAIL,
208     * DAEMON, AUTH, SYSLOG, LPR, NEWS, UUCP, CRON, AUTHPRIV, FTP, NTP, AUDIT,
209     * ALERT, CLOCK, LOCAL0, LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7.
210     * Case is not important.
211     * 
212     * <p>
213     * See {@link ch.qos.logback.core.net.SyslogConstants SyslogConstants} and RFC
214     * 3164 for more information about the <b>Facility</b> option.
215     */
216    public void setFacility(String facilityStr) {
217        if (facilityStr != null) {
218            facilityStr = facilityStr.trim();
219        }
220        this.facilityStr = facilityStr;
221    }
222
223    /**
224     * 
225     * @return
226     */
227    public int getPort() {
228        return port;
229    }
230
231    /**
232     * The port number on the syslog server to connect to. Normally, you would not
233     * want to change the default value, that is 514.
234     */
235    public void setPort(int port) {
236        this.port = port;
237    }
238
239    public int getMaxMessageSize() {
240        return maxMessageSize;
241    }
242
243    /**
244     * Maximum size for the syslog message (in characters); messages longer than
245     * this are truncated. The default value is 65400 (which is near the maximum for
246     * syslog-over-UDP). Note that the value is characters; the number of bytes may
247     * vary if non-ASCII characters are present.
248     */
249    public void setMaxMessageSize(int maxMessageSize) {
250        this.maxMessageSize = maxMessageSize;
251    }
252
253    public Layout<E> getLayout() {
254        return layout;
255    }
256
257    public void setLayout(Layout<E> layout) {
258        addWarn("The layout of a SyslogAppender cannot be set directly. See also " + SYSLOG_LAYOUT_URL);
259    }
260
261    @Override
262    public void stop() {
263        if (sos != null) {
264            sos.close();
265        }
266        super.stop();
267    }
268
269    /**
270     * See {@link #setSuffixPattern #setSuffixPattern(String)}.
271     * 
272     * @return
273     */
274    public String getSuffixPattern() {
275        return suffixPattern;
276    }
277
278    /**
279     * The <b>suffixPattern</b> option specifies the format of the non-standardized
280     * part of the message sent to the syslog server.
281     * 
282     * @param suffixPattern
283     */
284    public void setSuffixPattern(String suffixPattern) {
285        this.suffixPattern = suffixPattern;
286    }
287
288    /**
289     * Returns the Charset used to encode String messages into byte sequences when
290     * writing to syslog.
291     */
292    public Charset getCharset() {
293        return charset;
294    }
295
296    /**
297     * The Charset to use when encoding messages into byte sequences.
298     *
299     * @param charset
300     */
301    public void setCharset(Charset charset) {
302        this.charset = charset;
303    }
304}