001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.log4j.builders.appender;
018
019import static org.apache.log4j.builders.BuilderManager.CATEGORY;
020import static org.apache.log4j.config.Log4j1Configuration.THRESHOLD_PARAM;
021import static org.apache.log4j.xml.XmlConfiguration.FILTER_TAG;
022import static org.apache.log4j.xml.XmlConfiguration.LAYOUT_TAG;
023import static org.apache.log4j.xml.XmlConfiguration.NAME_ATTR;
024import static org.apache.log4j.xml.XmlConfiguration.PARAM_TAG;
025import static org.apache.log4j.xml.XmlConfiguration.VALUE_ATTR;
026import static org.apache.log4j.xml.XmlConfiguration.forEachElement;
027
028import java.io.Serializable;
029import java.util.Properties;
030import java.util.concurrent.atomic.AtomicInteger;
031import java.util.concurrent.atomic.AtomicReference;
032
033import org.apache.log4j.Appender;
034import org.apache.log4j.Layout;
035import org.apache.log4j.bridge.AppenderWrapper;
036import org.apache.log4j.bridge.LayoutAdapter;
037import org.apache.log4j.bridge.LayoutWrapper;
038import org.apache.log4j.builders.AbstractBuilder;
039import org.apache.log4j.config.Log4j1Configuration;
040import org.apache.log4j.config.PropertiesConfiguration;
041import org.apache.log4j.spi.Filter;
042import org.apache.log4j.xml.XmlConfiguration;
043import org.apache.logging.log4j.Logger;
044import org.apache.logging.log4j.core.appender.SocketAppender;
045import org.apache.logging.log4j.core.config.plugins.Plugin;
046import org.apache.logging.log4j.core.layout.SyslogLayout;
047import org.apache.logging.log4j.core.net.Facility;
048import org.apache.logging.log4j.core.net.Protocol;
049import org.apache.logging.log4j.status.StatusLogger;
050import org.w3c.dom.Element;
051
052/**
053 * Build a File Appender
054 */
055@Plugin(name = "org.apache.log4j.net.SyslogAppender", category = CATEGORY)
056public class SyslogAppenderBuilder extends AbstractBuilder implements AppenderBuilder {
057
058    private static final String DEFAULT_HOST = "localhost";
059    private static int DEFAULT_PORT = 514;
060    private static final String DEFAULT_FACILITY = "LOCAL0";
061
062    private static final Logger LOGGER = StatusLogger.getLogger();
063    private static final String FACILITY_PARAM = "Facility";
064    private static final String SYSLOG_HOST_PARAM = "SyslogHost";
065    private static final String PROTOCOL_PARAM = "protocol";
066
067
068    public SyslogAppenderBuilder() {
069    }
070
071    public SyslogAppenderBuilder(String prefix, Properties props) {
072        super(prefix, props);
073    }
074
075    @Override
076    public Appender parseAppender(Element appenderElement, XmlConfiguration config) {
077        String name = appenderElement.getAttribute(NAME_ATTR);
078        AtomicReference<Layout> layout = new AtomicReference<>();
079        AtomicReference<Filter> filter = new AtomicReference<>();
080        AtomicReference<String> facility = new AtomicReference<>();
081        AtomicReference<String> level = new AtomicReference<>();
082        AtomicReference<String> host = new AtomicReference<>();
083        AtomicReference<Protocol> protocol = new AtomicReference<>();
084        forEachElement(appenderElement.getChildNodes(), currentElement -> {
085            switch (currentElement.getTagName()) {
086                case LAYOUT_TAG:
087                    layout.set(config.parseLayout(currentElement));
088                    break;
089                case FILTER_TAG:
090                    filter.set(config.parseFilters(currentElement));
091                    break;
092                case PARAM_TAG: {
093                    switch (currentElement.getAttribute(NAME_ATTR)) {
094                        case SYSLOG_HOST_PARAM: {
095                            host.set(currentElement.getAttribute(VALUE_ATTR));
096                            break;
097                        }
098                        case FACILITY_PARAM:
099                            facility.set(currentElement.getAttribute(VALUE_ATTR));
100                            break;
101                        case THRESHOLD_PARAM: {
102                            String value = currentElement.getAttribute(VALUE_ATTR);
103                            if (value == null) {
104                                LOGGER.warn("No value supplied for Threshold parameter, ignoring.");
105                            } else {
106                                level.set(value);
107                            }
108                            break;
109                        }
110                        case PROTOCOL_PARAM:
111                            protocol.set(Protocol.valueOf(currentElement.getAttribute(VALUE_ATTR)));
112                            break;
113                    }
114                    break;
115                }
116            }
117        });
118
119        return createAppender(name, config, layout.get(), facility.get(), filter.get(), host.get(), level.get(), protocol.get());
120    }
121
122
123    @Override
124    public Appender parseAppender(final String name, final String appenderPrefix, final String layoutPrefix,
125            final String filterPrefix, final Properties props, final PropertiesConfiguration configuration) {
126        Filter filter = configuration.parseAppenderFilters(props, filterPrefix, name);
127        Layout layout = configuration.parseLayout(layoutPrefix, name, props);
128        String level = getProperty(THRESHOLD_PARAM);
129        String facility = getProperty(FACILITY_PARAM, DEFAULT_FACILITY);
130        String syslogHost = getProperty(SYSLOG_HOST_PARAM, DEFAULT_HOST + ":" + DEFAULT_PORT);
131        String protocol = getProperty(PROTOCOL_PARAM, Protocol.TCP.name());
132
133        return createAppender(name, configuration, layout, facility, filter, syslogHost, level, Protocol.valueOf(protocol));
134    }
135
136    private Appender createAppender(final String name, final Log4j1Configuration configuration, Layout layout,
137            String facility, final Filter filter, final String syslogHost, final String level, final Protocol protocol) {
138        AtomicReference<String> host = new AtomicReference<>();
139        AtomicInteger port = new AtomicInteger();
140        resolveSyslogHost(syslogHost, host, port);
141        org.apache.logging.log4j.core.Layout<? extends Serializable> appenderLayout;
142        if (layout instanceof LayoutWrapper) {
143            appenderLayout = ((LayoutWrapper) layout).getLayout();
144        } else if (layout != null) {
145            appenderLayout = new LayoutAdapter(layout);
146        } else {
147            appenderLayout = SyslogLayout.newBuilder()
148                    .setFacility(Facility.toFacility(facility))
149                    .setConfiguration(configuration)
150                    .build();
151        }
152
153        org.apache.logging.log4j.core.Filter fileFilter = buildFilters(level, filter);
154        return new AppenderWrapper(SocketAppender.newBuilder()
155                .setName(name)
156                .setConfiguration(configuration)
157                .setLayout(appenderLayout)
158                .setFilter(fileFilter)
159                .withPort(port.get())
160                .withProtocol(protocol)
161                .withHost(host.get())
162                .build());
163    }
164
165    private void resolveSyslogHost(String syslogHost, AtomicReference<String> host, AtomicInteger port) {
166        //
167        //  If not an unbracketed IPv6 address then
168        //      parse as a URL
169        //
170        String[] parts = syslogHost.split(":");
171        if (parts.length == 1) {
172            host.set(parts[0]);
173            port.set(DEFAULT_PORT);
174        } else if (parts.length == 2) {
175            host.set(parts[0]);
176            port.set(Integer.parseInt(parts[1]));
177        } else {
178            LOGGER.warn("Invalid {} setting: {}. Using default.", SYSLOG_HOST_PARAM, syslogHost);
179            host.set(DEFAULT_HOST);
180            port.set(DEFAULT_PORT);
181        }
182    }
183}