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.logging.log4j.core.config.xml;
018
019import java.io.ByteArrayInputStream;
020import java.io.File;
021import java.io.IOException;
022import java.io.InputStream;
023import java.util.ArrayList;
024import java.util.Arrays;
025import java.util.List;
026import java.util.Map;
027
028import javax.xml.XMLConstants;
029import javax.xml.parsers.DocumentBuilder;
030import javax.xml.parsers.DocumentBuilderFactory;
031import javax.xml.parsers.ParserConfigurationException;
032import javax.xml.transform.Source;
033import javax.xml.transform.stream.StreamSource;
034import javax.xml.validation.Schema;
035import javax.xml.validation.SchemaFactory;
036import javax.xml.validation.Validator;
037
038import org.apache.logging.log4j.core.config.AbstractConfiguration;
039import org.apache.logging.log4j.core.config.Configuration;
040import org.apache.logging.log4j.core.config.ConfigurationSource;
041import org.apache.logging.log4j.core.config.ConfiguratonFileWatcher;
042import org.apache.logging.log4j.core.config.Node;
043import org.apache.logging.log4j.core.config.Reconfigurable;
044import org.apache.logging.log4j.core.config.plugins.util.PluginType;
045import org.apache.logging.log4j.core.config.plugins.util.ResolverUtil;
046import org.apache.logging.log4j.core.config.status.StatusConfiguration;
047import org.apache.logging.log4j.core.util.Closer;
048import org.apache.logging.log4j.core.util.FileWatcher;
049import org.apache.logging.log4j.core.util.Loader;
050import org.apache.logging.log4j.core.util.Patterns;
051import org.apache.logging.log4j.core.util.Throwables;
052import org.w3c.dom.Attr;
053import org.w3c.dom.Document;
054import org.w3c.dom.Element;
055import org.w3c.dom.NamedNodeMap;
056import org.w3c.dom.NodeList;
057import org.w3c.dom.Text;
058import org.xml.sax.InputSource;
059import org.xml.sax.SAXException;
060
061/**
062 * Creates a Node hierarchy from an XML file.
063 */
064public class XmlConfiguration extends AbstractConfiguration implements Reconfigurable {
065
066    private static final String XINCLUDE_FIXUP_LANGUAGE =
067            "http://apache.org/xml/features/xinclude/fixup-language";
068    private static final String XINCLUDE_FIXUP_BASE_URIS =
069            "http://apache.org/xml/features/xinclude/fixup-base-uris";
070    private static final String[] VERBOSE_CLASSES = new String[] {ResolverUtil.class.getName()};
071    private static final String LOG4J_XSD = "Log4j-config.xsd";
072
073    private final List<Status> status = new ArrayList<>();
074    private Element rootElement;
075    private boolean strict;
076    private String schemaResource;
077
078    public XmlConfiguration(final ConfigurationSource configSource) {
079        super(configSource);
080        final File configFile = configSource.getFile();
081        byte[] buffer = null;
082
083        try {
084            final InputStream configStream = configSource.getInputStream();
085            try {
086                buffer = toByteArray(configStream);
087            } finally {
088                Closer.closeSilently(configStream);
089            }
090            final InputSource source = new InputSource(new ByteArrayInputStream(buffer));
091            source.setSystemId(configSource.getLocation());
092            final DocumentBuilder documentBuilder = newDocumentBuilder(true);
093            Document document;
094            try {
095                document = documentBuilder.parse(source);
096            } catch (final Exception e) {
097                // LOG4J2-1127
098                final Throwable throwable = Throwables.getRootCause(e);
099                if (throwable instanceof UnsupportedOperationException) {
100                    LOGGER.warn(
101                            "The DocumentBuilder {} does not support an operation: {}."
102                            + "Trying again without XInclude...",
103                            documentBuilder, e);
104                    document = newDocumentBuilder(false).parse(source);
105                } else {
106                    throw e;
107                }
108            }
109            rootElement = document.getDocumentElement();
110            final Map<String, String> attrs = processAttributes(rootNode, rootElement);
111            final StatusConfiguration statusConfig = new StatusConfiguration().withVerboseClasses(VERBOSE_CLASSES)
112                    .withStatus(getDefaultStatus());
113            for (final Map.Entry<String, String> entry : attrs.entrySet()) {
114                final String key = entry.getKey();
115                final String value = getStrSubstitutor().replace(entry.getValue());
116                if ("status".equalsIgnoreCase(key)) {
117                    statusConfig.withStatus(value);
118                } else if ("dest".equalsIgnoreCase(key)) {
119                    statusConfig.withDestination(value);
120                } else if ("shutdownHook".equalsIgnoreCase(key)) {
121                    isShutdownHookEnabled = !"disable".equalsIgnoreCase(value);
122                } else if ("verbose".equalsIgnoreCase(key)) {
123                    statusConfig.withVerbosity(value);
124                } else if ("packages".equalsIgnoreCase(key)) {
125                    pluginPackages.addAll(Arrays.asList(value.split(Patterns.COMMA_SEPARATOR)));
126                } else if ("name".equalsIgnoreCase(key)) {
127                    setName(value);
128                } else if ("strict".equalsIgnoreCase(key)) {
129                    strict = Boolean.parseBoolean(value);
130                } else if ("schema".equalsIgnoreCase(key)) {
131                    schemaResource = value;
132                } else if ("monitorInterval".equalsIgnoreCase(key)) {
133                    final int intervalSeconds = Integer.parseInt(value);
134                    if (intervalSeconds > 0) {
135                        getWatchManager().setIntervalSeconds(intervalSeconds);
136                        if (configFile != null) {
137                            final FileWatcher watcher = new ConfiguratonFileWatcher(this, listeners);
138                            getWatchManager().watchFile(configFile, watcher);
139                        }
140                    }
141                } else if ("advertiser".equalsIgnoreCase(key)) {
142                    createAdvertiser(value, configSource, buffer, "text/xml");
143                }
144            }
145            statusConfig.initialize();
146        } catch (final SAXException | IOException | ParserConfigurationException e) {
147            LOGGER.error("Error parsing " + configSource.getLocation(), e);
148        }
149        if (strict && schemaResource != null && buffer != null) {
150            InputStream is = null;
151            try {
152                is = Loader.getResourceAsStream(schemaResource, XmlConfiguration.class.getClassLoader());
153            } catch (final Exception ex) {
154                LOGGER.error("Unable to access schema {}", this.schemaResource, ex);
155            }
156            if (is != null) {
157                final Source src = new StreamSource(is, LOG4J_XSD);
158                final SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
159                Schema schema = null;
160                try {
161                    schema = factory.newSchema(src);
162                } catch (final SAXException ex) {
163                    LOGGER.error("Error parsing Log4j schema", ex);
164                }
165                if (schema != null) {
166                    final Validator validator = schema.newValidator();
167                    try {
168                        validator.validate(new StreamSource(new ByteArrayInputStream(buffer)));
169                    } catch (final IOException ioe) {
170                        LOGGER.error("Error reading configuration for validation", ioe);
171                    } catch (final SAXException ex) {
172                        LOGGER.error("Error validating configuration", ex);
173                    }
174                }
175            }
176        }
177
178        if (getName() == null) {
179            setName(configSource.getLocation());
180        }
181    }
182
183    /**
184     * Creates a new DocumentBuilder suitable for parsing a configuration file.
185     * 
186     * @param xIncludeAware enabled XInclude
187     * @return a new DocumentBuilder
188     * @throws ParserConfigurationException
189     */
190    static DocumentBuilder newDocumentBuilder(final boolean xIncludeAware) throws ParserConfigurationException {
191        final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
192        factory.setNamespaceAware(true);
193        if (xIncludeAware) {
194            enableXInclude(factory);
195        }
196        return factory.newDocumentBuilder();
197    }
198
199    /**
200     * Enables XInclude for the given DocumentBuilderFactory
201     *
202     * @param factory a DocumentBuilderFactory
203     */
204    private static void enableXInclude(final DocumentBuilderFactory factory) {
205        try {
206            // Alternative: We set if a system property on the command line is set, for example:
207            // -DLog4j.XInclude=true
208            factory.setXIncludeAware(true);
209        } catch (final UnsupportedOperationException e) {
210            LOGGER.warn("The DocumentBuilderFactory [{}] does not support XInclude: {}", factory, e);
211        } catch (@SuppressWarnings("ErrorNotRethrown") final AbstractMethodError | NoSuchMethodError err) {
212            LOGGER.warn("The DocumentBuilderFactory [{}] is out of date and does not support XInclude: {}", factory,
213                    err);
214        }
215        try {
216            // Alternative: We could specify all features and values with system properties like:
217            // -DLog4j.DocumentBuilderFactory.Feature="http://apache.org/xml/features/xinclude/fixup-base-uris true"
218            factory.setFeature(XINCLUDE_FIXUP_BASE_URIS, true);
219        } catch (final ParserConfigurationException e) {
220            LOGGER.warn("The DocumentBuilderFactory [{}] does not support the feature [{}]: {}", factory,
221                    XINCLUDE_FIXUP_BASE_URIS, e);
222        } catch (@SuppressWarnings("ErrorNotRethrown") final AbstractMethodError err) {
223            LOGGER.warn("The DocumentBuilderFactory [{}] is out of date and does not support setFeature: {}", factory,
224                    err);
225        }
226        try {
227            factory.setFeature(XINCLUDE_FIXUP_LANGUAGE, true);
228        } catch (final ParserConfigurationException e) {
229            LOGGER.warn("The DocumentBuilderFactory [{}] does not support the feature [{}]: {}", factory,
230                    XINCLUDE_FIXUP_LANGUAGE, e);
231        } catch (@SuppressWarnings("ErrorNotRethrown") final AbstractMethodError err) {
232            LOGGER.warn("The DocumentBuilderFactory [{}] is out of date and does not support setFeature: {}", factory,
233                    err);
234        }
235    }
236
237    @Override
238    public void setup() {
239        if (rootElement == null) {
240            LOGGER.error("No logging configuration");
241            return;
242        }
243        constructHierarchy(rootNode, rootElement);
244        if (status.size() > 0) {
245            for (final Status s : status) {
246                LOGGER.error("Error processing element {} ({}): {}", s.name, s.element, s.errorType);
247            }
248            return;
249        }
250        rootElement = null;
251    }
252
253    @Override
254    public Configuration reconfigure() {
255        try {
256            final ConfigurationSource source = getConfigurationSource().resetInputStream();
257            if (source == null) {
258                return null;
259            }
260            final XmlConfiguration config = new XmlConfiguration(source);
261            return config.rootElement == null ? null : config;
262        } catch (final IOException ex) {
263            LOGGER.error("Cannot locate file {}", getConfigurationSource(), ex);
264        }
265        return null;
266    }
267
268    private void constructHierarchy(final Node node, final Element element) {
269        processAttributes(node, element);
270        final StringBuilder buffer = new StringBuilder();
271        final NodeList list = element.getChildNodes();
272        final List<Node> children = node.getChildren();
273        for (int i = 0; i < list.getLength(); i++) {
274            final org.w3c.dom.Node w3cNode = list.item(i);
275            if (w3cNode instanceof Element) {
276                final Element child = (Element) w3cNode;
277                final String name = getType(child);
278                final PluginType<?> type = pluginManager.getPluginType(name);
279                final Node childNode = new Node(node, name, type);
280                constructHierarchy(childNode, child);
281                if (type == null) {
282                    final String value = childNode.getValue();
283                    if (!childNode.hasChildren() && value != null) {
284                        node.getAttributes().put(name, value);
285                    } else {
286                        status.add(new Status(name, element, ErrorType.CLASS_NOT_FOUND));
287                    }
288                } else {
289                    children.add(childNode);
290                }
291            } else if (w3cNode instanceof Text) {
292                final Text data = (Text) w3cNode;
293                buffer.append(data.getData());
294            }
295        }
296
297        final String text = buffer.toString().trim();
298        if (text.length() > 0 || (!node.hasChildren() && !node.isRoot())) {
299            node.setValue(text);
300        }
301    }
302
303    private String getType(final Element element) {
304        if (strict) {
305            final NamedNodeMap attrs = element.getAttributes();
306            for (int i = 0; i < attrs.getLength(); ++i) {
307                final org.w3c.dom.Node w3cNode = attrs.item(i);
308                if (w3cNode instanceof Attr) {
309                    final Attr attr = (Attr) w3cNode;
310                    if (attr.getName().equalsIgnoreCase("type")) {
311                        final String type = attr.getValue();
312                        attrs.removeNamedItem(attr.getName());
313                        return type;
314                    }
315                }
316            }
317        }
318        return element.getTagName();
319    }
320
321    private Map<String, String> processAttributes(final Node node, final Element element) {
322        final NamedNodeMap attrs = element.getAttributes();
323        final Map<String, String> attributes = node.getAttributes();
324
325        for (int i = 0; i < attrs.getLength(); ++i) {
326            final org.w3c.dom.Node w3cNode = attrs.item(i);
327            if (w3cNode instanceof Attr) {
328                final Attr attr = (Attr) w3cNode;
329                if (attr.getName().equals("xml:base")) {
330                    continue;
331                }
332                attributes.put(attr.getName(), attr.getValue());
333            }
334        }
335        return attributes;
336    }
337
338    @Override
339    public String toString() {
340        return getClass().getSimpleName() + "[location=" + getConfigurationSource() + "]";
341    }
342
343    /**
344     * The error that occurred.
345     */
346    private enum ErrorType {
347        CLASS_NOT_FOUND
348    }
349
350    /**
351     * Status for recording errors.
352     */
353    private static class Status {
354        private final Element element;
355        private final String name;
356        private final ErrorType errorType;
357
358        public Status(final String name, final Element element, final ErrorType errorType) {
359            this.name = name;
360            this.element = element;
361            this.errorType = errorType;
362        }
363
364        @Override
365        public String toString() {
366            return "Status [name=" + name + ", element=" + element + ", errorType=" + errorType + "]";
367        }
368
369    }
370
371}