Proposed support for reading .btm scripts from a jar URL

https://issues.redhat.com/projects/BYTEMAN/issues/BYTEMAN-437

Signed-off-by: Scott M Stark <starksm64@gmail.com>

agent/pom.xml

@@ -63,6 +63,14 @@
                         </manifestEntries>
                     </archive>
                 </configuration>
+                <!-- Create a tests artifact -->
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>test-jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -2415,6 +2423,25 @@
 							<argLine>-Dorg.jboss.byteman.compile.to.bytecode -javaagent:${project.build.directory}/byteman-agent-${project.version}.jar=listener:true</argLine>
                         </configuration>
 					</execution>
+                    <!-- Test accessing the script from a jar url -->
+                    <execution>
+                        <id>jar.TestScriptFromJar</id>
+                        <phase>integration-test</phase>
+                        <goals>
+                            <goal>integration-test</goal>
+                            <goal>verify</goal>
+                        </goals>
+                        <configuration>
+                            <forkCount>1</forkCount>
+                            <reuseForks>true</reuseForks>
+                            <test>TestScriptFromJar</test>
+                            <includes>
+                                <include>org/jboss/byteman/tests/jar/TestScriptFromJar.class</include>
+                            </includes>
+                            <!-- access script from  jar:file://...target/byteman-x.y.z-tests.jar!/scripts/jar/TestScriptFromJar.btm -->
+                            <argLine>-Dorg.jboss.byteman.compile.to.bytecode -javaagent:${project.build.directory}/byteman-agent-${project.version}.jar=script:jar:file://${project.build.directory}/byteman-agent-${project.version}-tests.jar!/scripts/jar/TestScriptFromJar.btm</argLine>
+                        </configuration>
+                    </execution>
                 </executions>
             </plugin>
             <!--

agent/src/main/java/org/jboss/byteman/agent/Main.java

@@ -32,7 +32,9 @@
 import java.lang.instrument.Instrumentation;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
+import java.net.JarURLConnection;
 import java.net.Socket;
+import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.jar.JarFile;
@@ -207,19 +209,26 @@ public static void premain(String args, Instrumentation inst)
         // look up rules in any script files
 
         for (String scriptPath : scriptPaths) {
-            FileInputStream fis = null;
+            InputStream is = null;
             try {
-                fis = new FileInputStream(scriptPath);
-                byte[] bytes = new byte[fis.available()];
-                fis.read(bytes);
+                if(scriptPath.startsWith("jar:")) {
+                    // A jar:<url>!/{entry}
+                    URL url = new URL(scriptPath);
+                    JarURLConnection jarConnection = (JarURLConnection) url.openConnection();
+                    is = jarConnection.getJarFile().getInputStream(jarConnection.getJarEntry());
+                } else {
+                    is = new FileInputStream(scriptPath);
+                }
+                byte[] bytes = new byte[is.available()];
+                is.read(bytes);
                 String ruleScript = new String(bytes);
                 scripts.add(ruleScript);
             } catch (IOException ioe) {
                 System.err.println("org.jboss.byteman.agent.Main: unable to read rule script file : " + scriptPath);
                 throw ioe;
             } finally {
-                if (fis != null)
-                    fis.close();
+                if (is != null)
+                    is.close();
             }
         }
 

agent/src/test/java/org/jboss/byteman/tests/jar/TestScriptFromJar.java

@@ -0,0 +1,60 @@
+/*
+ * JBoss, Home of Professional Open Source
+ * Copyright 2023, Red Hat and individual contributors
+ * by the @authors tag. See the copyright.txt in the distribution for a
+ * full listing of individual contributors.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ *
+ * @authors Andrew Dinn
+ */
+package org.jboss.byteman.tests.jar;
+
+import org.jboss.byteman.tests.Test;
+
+/**
+ * Validate that a script loaded from a jar file is correctly applied
+ * can be run using:
+ * mvn package failsafe:integration-test@jar.TestScriptFromJar
+ */
+public class TestScriptFromJar extends Test {
+    public TestScriptFromJar()
+    {
+        super(TestScriptFromJar.class.getCanonicalName());
+    }
+
+    public void test()
+    {
+        log("calling TestScriptFromJar.triggerMethod1");
+        triggerMethod1();
+        log("called TestScriptFromJar.triggerMethod1");
+    }
+
+    public void triggerMethod1()
+    {
+        log("inside TestScriptFromJar.triggerMethod1");
+    }
+
+    public String getExpected()
+    {
+        logExpected("calling TestScriptFromJar.triggerMethod1");
+        logExpected("caller match first caller");
+        logExpected("inside TestScriptFromJar.triggerMethod1");
+        logExpected("called TestScriptFromJar.triggerMethod1");
+
+        return super.getExpected();
+    }
+}

agent/src/test/resources/scripts/jar/TestScriptFromJar.btm

@@ -0,0 +1,33 @@
+##############################################################################
+# JBoss, Home of Professional Open Source
+# Copyright 2010, Red Hat and individual contributors
+# by the @authors tag. See the copyright.txt in the distribution for a
+# full listing of individual contributors.
+#
+# This is free software; you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as
+# published by the Free Software Foundation; either version 2.1 of
+# the License, or (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this software; if not, write to the Free
+# Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+# 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+#
+# @authors Andrew Dinn
+#
+
+RULE test caller match first caller
+CLASS TestScriptFromJar
+METHOD triggerMethod1()
+HELPER org.jboss.byteman.tests.helpers.Default
+AT ENTRY
+BIND test : TestScriptFromJar = $0
+IF callerEquals("test")
+DO test.log("caller match first caller")
+ENDRULE