org.elasticsearch.hadoop.script.GroovyScriptEngineService.java Source code

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/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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.elasticsearch.hadoop.script;

import groovy.lang.Binding;
import groovy.lang.GroovyClassLoader;
import groovy.lang.GroovyCodeSource;
import groovy.lang.Script;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.math.BigDecimal;
import java.nio.charset.StandardCharsets;
import java.security.AccessControlContext;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.Scorer;
import org.codehaus.groovy.ast.ClassCodeExpressionTransformer;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.expr.ConstantExpression;
import org.codehaus.groovy.ast.expr.Expression;
import org.codehaus.groovy.classgen.GeneratorContext;
import org.codehaus.groovy.control.CompilationFailedException;
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.control.CompilerConfiguration;
import org.codehaus.groovy.control.MultipleCompilationErrorsException;
import org.codehaus.groovy.control.SourceUnit;
import org.codehaus.groovy.control.customizers.CompilationCustomizer;
import org.codehaus.groovy.control.customizers.ImportCustomizer;
import org.codehaus.groovy.control.messages.Message;
import org.elasticsearch.SpecialPermission;
import org.elasticsearch.bootstrap.BootstrapInfo;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.component.AbstractComponent;
import org.elasticsearch.common.hash.MessageDigests;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.script.ClassPermission;
import org.elasticsearch.script.CompiledScript;
import org.elasticsearch.script.ExecutableScript;
import org.elasticsearch.script.LeafSearchScript;
import org.elasticsearch.script.ScoreAccessor;
import org.elasticsearch.script.ScriptEngineService;
import org.elasticsearch.script.ScriptException;
import org.elasticsearch.script.SearchScript;
import org.elasticsearch.search.lookup.LeafSearchLookup;
import org.elasticsearch.search.lookup.SearchLookup;

import static java.util.Collections.*;

/**
 * Provides the infrastructure for Groovy as a scripting language for Elasticsearch
 */
public class GroovyScriptEngineService extends AbstractComponent implements ScriptEngineService {

    /**
     * The name of the scripting engine/language.
     */
    public static final String NAME = "groovy";

    /**
     * The name of the Groovy compiler setting to use associated with activating <code>invokedynamic</code> support.
     */
    public static final String GROOVY_INDY_SETTING_NAME = "indy";

    /**
     * Classloader used as a parent classloader for all Groovy scripts
     */
    private final ClassLoader loader;

    /**
     * We want to use our log framework. Sorry log4j2...
     */
    private final Log log = LogFactory.getLog(GroovyScriptEngineService.class);

    public GroovyScriptEngineService(Settings settings) {
        super(settings);

        deprecationLogger.deprecated("[groovy] scripts are deprecated, use [painless] scripts instead");

        // Creates the classloader here in order to isolate Groovy-land code
        final SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
            sm.checkPermission(new SpecialPermission());
        }
        this.loader = AccessController.doPrivileged((PrivilegedAction<ClassLoader>) () -> {
            // snapshot our context (which has permissions for classes), since the script has none
            AccessControlContext context = AccessController.getContext();
            return new ClassLoader(getClass().getClassLoader()) {
                @Override
                protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
                    if (sm != null) {
                        try {
                            context.checkPermission(new ClassPermission(name));
                        } catch (SecurityException e) {
                            throw new ClassNotFoundException(name, e);
                        }
                    }
                    return super.loadClass(name, resolve);
                }
            };
        });
    }

    @Override
    public void close() throws IOException {
        // Nothing to do here
    }

    @Override
    public String getType() {
        return NAME;
    }

    @Override
    public String getExtension() {
        return NAME;
    }

    @Override
    public Object compile(String scriptName, String scriptSource, Map<String, String> params) {
        // Create the script class name
        String className = MessageDigests
                .toHexString(MessageDigests.sha1().digest(scriptSource.getBytes(StandardCharsets.UTF_8)));

        final SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
            sm.checkPermission(new SpecialPermission());
        }
        return AccessController.doPrivileged(new PrivilegedAction<Object>() {
            @Override
            public Object run() {
                try {
                    GroovyCodeSource codeSource = new GroovyCodeSource(scriptSource, className,
                            BootstrapInfo.UNTRUSTED_CODEBASE);
                    codeSource.setCachable(false);

                    CompilerConfiguration configuration = new CompilerConfiguration()
                            .addCompilationCustomizers(new ImportCustomizer().addStarImports("org.joda.time")
                                    .addStaticStars("java.lang.Math"))
                            .addCompilationCustomizers(new GroovyBigDecimalTransformer(CompilePhase.CONVERSION));

                    // always enable invokeDynamic, not the crazy softreference-based stuff
                    configuration.getOptimizationOptions().put(GROOVY_INDY_SETTING_NAME, true);

                    GroovyClassLoader groovyClassLoader = new GroovyClassLoader(loader, configuration);
                    return groovyClassLoader.parseClass(codeSource);
                } catch (Exception e) {
                    if (log.isTraceEnabled()) {
                        log.trace("Exception compiling Groovy script:", e);
                    }
                    throw convertToScriptException("Error compiling script " + className, scriptSource, e);
                }
            }
        });
    }

    /**
     * Return a script object with the given vars from the compiled script object
     */
    @SuppressWarnings("unchecked")
    private Script createScript(Object compiledScript, Map<String, Object> vars)
            throws ReflectiveOperationException {
        Class<?> scriptClass = (Class<?>) compiledScript;
        Script scriptObject = (Script) scriptClass.getConstructor().newInstance();
        Binding binding = new Binding();
        binding.getVariables().putAll(vars);
        scriptObject.setBinding(binding);
        return scriptObject;
    }

    @Override
    public ExecutableScript executable(CompiledScript compiledScript, Map<String, Object> vars) {
        deprecationLogger.deprecated("[groovy] scripts are deprecated, use [painless] scripts instead");

        try {
            Map<String, Object> allVars = new HashMap<>();
            if (vars != null) {
                allVars.putAll(vars);
            }
            return new GroovyScript(compiledScript, createScript(compiledScript.compiled(), allVars), log);
        } catch (ReflectiveOperationException e) {
            throw convertToScriptException("Failed to build executable script", compiledScript.name(), e);
        }
    }

    @Override
    public SearchScript search(final CompiledScript compiledScript, final SearchLookup lookup,
            @Nullable final Map<String, Object> vars) {
        deprecationLogger.deprecated("[groovy] scripts are deprecated, use [painless] scripts instead");

        return new SearchScript() {

            @Override
            public LeafSearchScript getLeafSearchScript(LeafReaderContext context) throws IOException {
                final LeafSearchLookup leafLookup = lookup.getLeafSearchLookup(context);
                Map<String, Object> allVars = new HashMap<>();
                allVars.putAll(leafLookup.asMap());
                if (vars != null) {
                    allVars.putAll(vars);
                }
                Script scriptObject;
                try {
                    scriptObject = createScript(compiledScript.compiled(), allVars);
                } catch (ReflectiveOperationException e) {
                    throw convertToScriptException("Failed to build search script", compiledScript.name(), e);
                }
                return new GroovyScript(compiledScript, scriptObject, leafLookup, log);
            }

            @Override
            public boolean needsScores() {
                // TODO: can we reliably know if a groovy script makes use of _score
                return true;
            }
        };
    }

    /**
     * Converts a {@link Throwable} to a {@link ScriptException}
     */
    private ScriptException convertToScriptException(String message, String source, Throwable cause) {
        List<String> stack = new ArrayList<>();
        if (cause instanceof MultipleCompilationErrorsException) {
            @SuppressWarnings({ "unchecked" })
            List<Message> errors = (List<Message>) ((MultipleCompilationErrorsException) cause).getErrorCollector()
                    .getErrors();
            for (Message error : errors) {
                try (StringWriter writer = new StringWriter()) {
                    error.write(new PrintWriter(writer));
                    stack.add(writer.toString());
                } catch (IOException e1) {
                    log.error("failed to write compilation error message to the stack", e1);
                }
            }
        } else if (cause instanceof CompilationFailedException) {
            CompilationFailedException error = (CompilationFailedException) cause;
            stack.add(error.getMessage());
        }
        throw new ScriptException(message, cause, stack, source, NAME);
    }

    public static final class GroovyScript implements ExecutableScript, LeafSearchScript {

        private final CompiledScript compiledScript;
        private final Script script;
        private final LeafSearchLookup lookup;
        private final Map<String, Object> variables;
        private final Log logger;

        public GroovyScript(CompiledScript compiledScript, Script script, Log logger) {
            this(compiledScript, script, null, logger);
        }

        @SuppressWarnings("unchecked")
        public GroovyScript(CompiledScript compiledScript, Script script, @Nullable LeafSearchLookup lookup,
                Log logger) {
            this.compiledScript = compiledScript;
            this.script = script;
            this.lookup = lookup;
            this.logger = logger;
            this.variables = script.getBinding().getVariables();
        }

        @Override
        public void setScorer(Scorer scorer) {
            this.variables.put("_score", new ScoreAccessor(scorer));
        }

        @Override
        public void setDocument(int doc) {
            if (lookup != null) {
                lookup.setDocument(doc);
            }
        }

        @Override
        public void setNextVar(String name, Object value) {
            variables.put(name, value);
        }

        @Override
        public void setSource(Map<String, Object> source) {
            if (lookup != null) {
                lookup.source().setSource(source);
            }
        }

        @Override
        public Object run() {
            try {
                // NOTE: we truncate the stack because IndyInterface has security issue (needs getClassLoader)
                // we don't do a security check just as a tradeoff, it cannot really escalate to anything.
                return AccessController.doPrivileged(new PrivilegedAction<Object>() {
                    @Override
                    public Object run() {
                        return script.run();
                    }
                });
            } catch (AssertionError ae) {
                // Groovy asserts are not java asserts, and cannot be disabled, so we do a best-effort trying to determine if this is a
                // Groovy assert (in which case we wrap it and throw), or a real Java assert, in which case we rethrow it as-is, likely
                // resulting in the uncaughtExceptionHandler handling it.
                final StackTraceElement[] elements = ae.getStackTrace();
                if (elements.length > 0
                        && "org.codehaus.groovy.runtime.InvokerHelper".equals(elements[0].getClassName())) {
                    if (logger.isTraceEnabled()) {
                        logger.trace(String.format("failed to run {%s}", compiledScript), ae);
                        throw new ScriptException("Error evaluating " + compiledScript.name(), ae, emptyList(), "",
                                compiledScript.lang());
                    }
                }
                throw ae;
            } catch (Exception | NoClassDefFoundError e) {
                if (logger.isTraceEnabled()) {
                    logger.trace(String.format("failed to run {%s}", compiledScript), e);
                }
                throw new ScriptException("Error evaluating " + compiledScript.name(), e, emptyList(), "",
                        compiledScript.lang());
            }
        }

        @Override
        public long runAsLong() {
            return ((Number) run()).longValue();
        }

        @Override
        public double runAsDouble() {
            return ((Number) run()).doubleValue();
        }
    }

    /**
     * A compilation customizer that is used to transform a number like 1.23,
     * which would normally be a BigDecimal, into a double value.
     */
    private class GroovyBigDecimalTransformer extends CompilationCustomizer {

        private GroovyBigDecimalTransformer(CompilePhase phase) {
            super(phase);
        }

        @Override
        public void call(final SourceUnit source, final GeneratorContext context, final ClassNode classNode)
                throws CompilationFailedException {
            new BigDecimalExpressionTransformer(source).visitClass(classNode);
        }
    }

    /**
     * Groovy expression transformer that converts BigDecimals to doubles
     */
    private class BigDecimalExpressionTransformer extends ClassCodeExpressionTransformer {

        private final SourceUnit source;

        private BigDecimalExpressionTransformer(SourceUnit source) {
            this.source = source;
        }

        @Override
        protected SourceUnit getSourceUnit() {
            return this.source;
        }

        @Override
        public Expression transform(Expression expr) {
            Expression newExpr = expr;
            if (expr instanceof ConstantExpression) {
                ConstantExpression constExpr = (ConstantExpression) expr;
                Object val = constExpr.getValue();
                if (val != null && val instanceof BigDecimal) {
                    newExpr = new ConstantExpression(((BigDecimal) val).doubleValue());
                }
            }
            return super.transform(newExpr);
        }
    }
}