diff --git a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/DatadogClassLoader.java b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/DatadogClassLoader.java index 1aaeef6d4e..7ef4b70725 100644 --- a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/DatadogClassLoader.java +++ b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/DatadogClassLoader.java @@ -1,9 +1,28 @@ package datadog.trace.bootstrap; +import java.io.ByteArrayInputStream; +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.net.MalformedURLException; import java.net.URL; import java.net.URLClassLoader; +import java.net.URLConnection; +import java.net.URLStreamHandler; +import java.nio.file.NoSuchFileException; +import java.util.HashMap; +import java.util.Map; +import java.util.jar.JarEntry; +import java.util.jar.JarInputStream; +import lombok.extern.slf4j.Slf4j; -/** Classloader used to run the core datadog agent. */ +/** + * Classloader used to run the core datadog agent. + * + *

It is built around the concept of a jar inside another jar. This classloader loads the files + * of the internal jar to load classes and resources. + */ +@Slf4j public class DatadogClassLoader extends URLClassLoader { static { ClassLoader.registerAsParallelCapable(); @@ -19,17 +38,41 @@ public class DatadogClassLoader extends URLClassLoader { * Construct a new DatadogClassLoader * * @param bootstrapJarLocation Used for resource lookups. - * @param agentJarLocation Classpath of this classloader. + * @param internalJarFileName File name of the internal jar * @param parent Classloader parent. Should null (bootstrap), or the platform classloader for java * 9+. */ - public DatadogClassLoader(URL bootstrapJarLocation, URL agentJarLocation, ClassLoader parent) { - super(new URL[] {agentJarLocation}, parent); - bootstrapProxy = new BootstrapClassLoaderProxy(new URL[] {bootstrapJarLocation}, null); + public DatadogClassLoader( + final URL bootstrapJarLocation, + final String internalJarFileName, + final ClassLoader classloaderForJarResource, + final ClassLoader parent) { + super(new URL[] {}, parent); + bootstrapProxy = new BootstrapClassLoaderProxy(new URL[] {bootstrapJarLocation}); + + if (classloaderForJarResource != null) { // Some tests pass null + try { + // The fields of the URL are mostly dummy. InternalJarURLHandler is the only important + // field. If extending this class from Classloader instead of URLClassloader required less + // boilerplate it could be used and the need for dummy fields would be reduced + final URL internalJarURL = + new URL( + "x-internal-jar", + null, + 0, + "/", + new InternalJarURLHandler(internalJarFileName, classloaderForJarResource)); + + addURL(internalJarURL); + } catch (final MalformedURLException e) { + // This can't happen with current URL constructor + log.error("URL malformed. Unsupported JDK?", e); + } + } } @Override - public URL getResource(String resourceName) { + public URL getResource(final String resourceName) { final URL bootstrapResource = bootstrapProxy.getResource(resourceName); if (null == bootstrapResource) { return super.getResource(resourceName); @@ -61,18 +104,103 @@ public class DatadogClassLoader extends URLClassLoader { ClassLoader.registerAsParallelCapable(); } - public BootstrapClassLoaderProxy(URL[] urls, ClassLoader parent) { - super(urls, parent); + public BootstrapClassLoaderProxy(final URL[] urls) { + super(urls); } @Override - public void addURL(URL url) { + public void addURL(final URL url) { super.addURL(url); } @Override - protected Class findClass(String name) throws ClassNotFoundException { + protected Class findClass(final String name) throws ClassNotFoundException { throw new ClassNotFoundException(name); } } + + private static class InternalJarURLHandler extends URLStreamHandler { + private final Map filenameToBytes = new HashMap<>(); + + public InternalJarURLHandler( + final String internalJarFileName, final ClassLoader classloaderForJarResource) { + + final InputStream jarStream = + classloaderForJarResource.getResourceAsStream(internalJarFileName); + + if (jarStream != null) { + try (final JarInputStream inputStream = new JarInputStream(jarStream)) { + JarEntry entry = inputStream.getNextJarEntry(); + + while (entry != null) { + filenameToBytes.put("/" + entry.getName(), getBytes(inputStream)); + + entry = inputStream.getNextJarEntry(); + } + + } catch (final IOException e) { + log.error("Unable to read internal jar", e); + } + } else { + log.error("Internal jar not found"); + } + } + + @Override + protected URLConnection openConnection(final URL url) throws IOException { + final byte[] bytes = filenameToBytes.get(url.getFile()); + + if (bytes == null) { + throw new NoSuchFileException(url.getFile()); + } + + return new InternalJarURLConnection(url, bytes); + } + } + + private static class InternalJarURLConnection extends URLConnection { + private final byte[] bytes; + + private InternalJarURLConnection(final URL url, final byte[] bytes) { + super(url); + this.bytes = bytes; + } + + @Override + public void connect() throws IOException { + connected = true; + } + + @Override + public InputStream getInputStream() throws IOException { + return new ByteArrayInputStream(bytes); + } + } + + /** + * Standard "copy InputStream to byte[]" implementation using a ByteArrayOutputStream + * + *

IOUtils.toByteArray() or Java 9's InputStream.readAllBytes() could be replacements if they + * were available + * + *

This can be optimized using the JarEntry's size(), but its not always available + * + * @param inputStream + * @return a byte[] from the inputstream + * @throws IOException + */ + private static byte[] getBytes(final InputStream inputStream) throws IOException { + final byte[] buffer = new byte[4096]; + + int bytesRead = inputStream.read(buffer, 0, buffer.length); + try (final ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) { + while (bytesRead != -1) { + outputStream.write(buffer, 0, bytesRead); + + bytesRead = inputStream.read(buffer, 0, buffer.length); + } + + return outputStream.toByteArray(); + } + } } diff --git a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/DatadogClassLoaderTest.groovy b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/DatadogClassLoaderTest.groovy index e46c335a6c..7e26f18ae9 100644 --- a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/DatadogClassLoaderTest.groovy +++ b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/DatadogClassLoaderTest.groovy @@ -13,7 +13,7 @@ class DatadogClassLoaderTest extends Specification { def className1 = 'some/class/Name1' def className2 = 'some/class/Name2' final URL loc = getClass().getProtectionDomain().getCodeSource().getLocation() - final DatadogClassLoader ddLoader = new DatadogClassLoader(loc, loc, (ClassLoader) null) + final DatadogClassLoader ddLoader = new DatadogClassLoader(loc, null, null, null) final Phaser threadHoldLockPhase = new Phaser(2) final Phaser acquireLockFromMainThreadPhase = new Phaser(2) diff --git a/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/Utils.java b/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/Utils.java index 931e0fc2c5..b689c70add 100644 --- a/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/Utils.java +++ b/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/Utils.java @@ -15,7 +15,7 @@ public class Utils { private static Method findLoadedClassMethod = null; private static final BootstrapClassLoaderProxy unitTestBootstrapProxy = - new BootstrapClassLoaderProxy(new URL[0], null); + new BootstrapClassLoaderProxy(new URL[0]); static { try { diff --git a/dd-java-agent/agent-tooling/src/test/groovy/datadog/trace/agent/test/ClassLoaderMatcherTest.groovy b/dd-java-agent/agent-tooling/src/test/groovy/datadog/trace/agent/test/ClassLoaderMatcherTest.groovy index b0563e86ce..0f32c8000b 100644 --- a/dd-java-agent/agent-tooling/src/test/groovy/datadog/trace/agent/test/ClassLoaderMatcherTest.groovy +++ b/dd-java-agent/agent-tooling/src/test/groovy/datadog/trace/agent/test/ClassLoaderMatcherTest.groovy @@ -16,7 +16,7 @@ class ClassLoaderMatcherTest extends Specification { def "skips agent classloader"() { setup: URL root = new URL("file://") - final URLClassLoader agentLoader = new DatadogClassLoader(root, root, null) + final URLClassLoader agentLoader = new DatadogClassLoader(root, null, null, null) expect: ClassLoaderMatcher.skipClassLoader().matches(agentLoader) } diff --git a/dd-java-agent/src/main/java/datadog/trace/agent/TracingAgent.java b/dd-java-agent/src/main/java/datadog/trace/agent/TracingAgent.java index f3a2152dab..635f9b60cd 100644 --- a/dd-java-agent/src/main/java/datadog/trace/agent/TracingAgent.java +++ b/dd-java-agent/src/main/java/datadog/trace/agent/TracingAgent.java @@ -31,8 +31,6 @@ public class TracingAgent { private static ClassLoader AGENT_CLASSLOADER = null; private static ClassLoader JMXFETCH_CLASSLOADER = null; private static File bootstrapJar = null; - private static File toolingJar = null; - private static File jmxFetchJar = null; public static void premain(final String agentArgs, final Instrumentation inst) throws Exception { agentmain(agentArgs, inst); @@ -81,7 +79,8 @@ public class TracingAgent { if (AGENT_CLASSLOADER == null) { // bootstrap jar must be appended before agent classloader is created. inst.appendToBootstrapClassLoaderSearch(new JarFile(bootstrapJar)); - final ClassLoader agentClassLoader = createDatadogClassLoader(bootstrapJar, toolingJar); + final ClassLoader agentClassLoader = + createDatadogClassLoader(bootstrapJar, "agent-tooling-and-instrumentation.jar.zip"); final ClassLoader contextLoader = Thread.currentThread().getContextClassLoader(); try { Thread.currentThread().setContextClassLoader(agentClassLoader); @@ -111,7 +110,8 @@ public class TracingAgent { public static synchronized void startJmxFetch() throws Exception { initializeJars(); if (JMXFETCH_CLASSLOADER == null) { - final ClassLoader jmxFetchClassLoader = createDatadogClassLoader(bootstrapJar, jmxFetchJar); + final ClassLoader jmxFetchClassLoader = + createDatadogClassLoader(bootstrapJar, "agent-jmxfetch.jar.zip"); final ClassLoader contextLoader = Thread.currentThread().getContextClassLoader(); try { Thread.currentThread().setContextClassLoader(jmxFetchClassLoader); @@ -151,18 +151,6 @@ public class TracingAgent { "agent-bootstrap.jar.zip", "agent-bootstrap.jar"); } - if (toolingJar == null) { - toolingJar = - extractToTmpFile( - TracingAgent.class.getClassLoader(), - "agent-tooling-and-instrumentation.jar.zip", - "agent-tooling-and-instrumentation.jar"); - } - if (jmxFetchJar == null) { - jmxFetchJar = - extractToTmpFile( - TracingAgent.class.getClassLoader(), "agent-jmxfetch.jar.zip", "agent-jmxfetch.jar"); - } } /** @@ -170,11 +158,12 @@ public class TracingAgent { * the bootstrap classpath. * * @param bootstrapJar datadog bootstrap jar which has been appended to the bootstrap loader - * @param toolingJar jar to use for the classpath of the datadog classloader + * @param innerJarFilename Filename of internal jar to use for the classpath of the datadog + * classloader * @return Datadog Classloader */ private static ClassLoader createDatadogClassLoader( - final File bootstrapJar, final File toolingJar) throws Exception { + final File bootstrapJar, final String innerJarFilename) throws Exception { final ClassLoader agentParent; final String javaVersion = System.getProperty("java.version"); if (javaVersion.startsWith("1.7") || javaVersion.startsWith("1.8")) { @@ -183,13 +172,18 @@ public class TracingAgent { // platform classloader is parent of system in java 9+ agentParent = getPlatformClassLoader(); } + final Class loaderClass = ClassLoader.getSystemClassLoader().loadClass("datadog.trace.bootstrap.DatadogClassLoader"); final Constructor constructor = - loaderClass.getDeclaredConstructor(URL.class, URL.class, ClassLoader.class); + loaderClass.getDeclaredConstructor( + URL.class, String.class, ClassLoader.class, ClassLoader.class); return (ClassLoader) constructor.newInstance( - bootstrapJar.toURI().toURL(), toolingJar.toURI().toURL(), agentParent); + bootstrapJar.toURI().toURL(), + innerJarFilename, + TracingAgent.class.getClassLoader(), + agentParent); } /** Extract sourcePath out of loader to a temporary file named destName. */