ScopedServletProcessor.java
/*
* Copyright (C) 2020-2024 by Savoir-faire Linux
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package net.jami.jams.common.annotations;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtMethod;
import javassist.LoaderClassPath;
import net.jami.jams.common.objects.user.AccessLevel;
import java.io.File;
import java.io.FileInputStream;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.HashMap;
import java.util.Set;
import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.RoundEnvironment;
import javax.annotation.processing.SupportedAnnotationTypes;
import javax.annotation.processing.SupportedOptions;
import javax.annotation.processing.SupportedSourceVersion;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.Element;
import javax.lang.model.element.TypeElement;
import javax.tools.Diagnostic;
@SupportedAnnotationTypes("net.jami.jams.common.annotations.ScopedServletMethod")
@SupportedSourceVersion(SourceVersion.RELEASE_11)
@SupportedOptions({"moduleDir", "parentDir"})
// This is a bit of hack to modify already compiled sources at compilation time
public class ScopedServletProcessor extends AbstractProcessor {
private String moduleDirectory = null;
private String parentDirectory = null;
public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
// Get the current project working directory:
moduleDirectory = processingEnv.getOptions().get("moduleDir");
parentDirectory = processingEnv.getOptions().get("parentDir");
processingEnv
.getMessager()
.printMessage(Diagnostic.Kind.NOTE, "Project Directory: " + moduleDirectory);
if (roundEnv.processingOver()) {
return false;
}
processingEnv
.getMessager()
.printMessage(
Diagnostic.Kind.NOTE,
"Working in directory: " + System.getProperty("user.dir"));
Set<? extends Element> annotatedElements =
roundEnv.getElementsAnnotatedWith(ScopedServletMethod.class);
// Inside each annotation, we have a list of stuff.
HashMap<String, HashMap<String, AccessLevel[]>> annList = new HashMap<>();
annotatedElements.forEach(
element -> {
processingEnv
.getMessager()
.printMessage(
Diagnostic.Kind.NOTE,
"Found class: " + element.getEnclosingElement().toString());
processingEnv
.getMessager()
.printMessage(Diagnostic.Kind.NOTE, "Found method: " + element);
processingEnv
.getMessager()
.printMessage(
Diagnostic.Kind.NOTE,
"Found "
+ element.getAnnotation(ScopedServletMethod.class)
.securityGroups()
.length
+ " groups");
String clsName = element.getEnclosingElement().toString();
String mthName = element.toString();
AccessLevel[] levels =
element.getAnnotation(ScopedServletMethod.class).securityGroups();
annList.putIfAbsent(clsName, new HashMap<>());
annList.get(clsName).putIfAbsent(mthName, levels);
});
annList.forEach(this::processClass);
return true;
}
private void processClass(String classname, HashMap<String, AccessLevel[]> methodNames) {
try {
URL cpUrl1 =
new URL(
"jar:file:"
+ parentDirectory
+ File.separator
+ "compile-libs/tomcat-embed-core-10.1.19.jar!/");
URL cpUrl3 =
new URL(
"jar:file:"
+ parentDirectory
+ File.separator
+ "compile-libs/tomcat-annotations-api-10.1.19.jar!/");
URLClassLoader cpUrlLoader = new URLClassLoader(new URL[] {cpUrl1, cpUrl3});
StringBuilder path = new StringBuilder();
path.append(moduleDirectory);
path.append(File.separator);
path.append("target");
path.append(File.separator);
path.append("classes");
path.append(File.separator);
path.append(classname.replaceAll("\\.", File.separator));
path.append(".class");
processingEnv
.getMessager()
.printMessage(Diagnostic.Kind.MANDATORY_WARNING, "Now processing: " + path);
ClassPool pool = ClassPool.getDefault();
// Load tomcat & commons classpath..
pool.insertClassPath(new LoaderClassPath(cpUrlLoader));
pool.makeClass(
new FileInputStream(
parentDirectory
+ "/jams-common/target/classes/net/jami/jams/common/objects/user/AccessLevel.class"));
pool.makeClass(
new FileInputStream(
parentDirectory
+ "/jams-common/target/classes/net/jami/jams/common/serialization/tomcat/TomcatCustomErrorHandler.class"));
CtClass ctClass = pool.makeClass(new FileInputStream(path.toString()));
processingEnv
.getMessager()
.printMessage(Diagnostic.Kind.MANDATORY_WARNING, ctClass.getName());
// Now that we have the CtClass we copy past
for (String rawmethodName : methodNames.keySet()) {
String methodName = rawmethodName.split("\\(")[0];
for (int i = 0; i < ctClass.getMethods().length; i++) {
CtMethod method = ctClass.getMethods()[i];
if (method.getName().equals(methodName)) {
// Insert code.
StringBuilder sb = new StringBuilder();
sb.append("{\n");
sb.append("boolean allowed = false;\n");
sb.append(
"net.jami.jams.common.objects.user.AccessLevel level = (net.jami.jams.common.objects.user.AccessLevel) req.getAttribute(\"accessLevel\");\n");
for (int j = 0; j < methodNames.get(rawmethodName).length; j++) {
sb.append(
"if(level == net.jami.jams.common.objects.user.AccessLevel.valueOf(\"")
.append(methodNames.get(rawmethodName)[j].toString())
.append("\")) allowed = true;\n");
}
sb.append("if(!allowed){\n");
sb.append(
"net.jami.jams.common.serialization.tomcat.TomcatCustomErrorHandler.sendCustomError(resp,403,\"You do not have sufficient permissions to access this resource!\");\n");
sb.append("return;\n");
sb.append("}\n");
sb.append("}\n");
ctClass.getMethods()[i].insertBefore(sb.toString());
}
}
}
// Perist the class before it gets copied into the binary.
path = new StringBuilder();
path.append(moduleDirectory);
path.append(File.separator);
path.append("target");
path.append(File.separator);
path.append("generated-sources");
ctClass.writeFile(path.toString());
processingEnv.getMessager().printMessage(Diagnostic.Kind.NOTE, "Saved the class...");
} catch (Exception e) {
processingEnv.getMessager().printMessage(Diagnostic.Kind.ERROR, e.getMessage());
}
}
// The only way to modify a file at this point would be to read it, and do a LOT of regex.
}