From 961331f029edfee17c585d83a2b84c7ca50869ec Mon Sep 17 00:00:00 2001 From: YoyoNow Date: Thu, 11 Jun 2026 13:19:04 +0200 Subject: [PATCH] Fix Agent and WideningTransformer and ClassPatcher --- .../de/steamwar/AccessWidenerScanner.java | 145 ------------------ .../src/main/java/de/steamwar/Agent.java | 30 ++-- .../main/java/de/steamwar/ClassPatcher.java | 26 ++-- .../src/main/java/de/steamwar/Utils.java | 60 ++++++++ .../java/de/steamwar/WideningTransformer.java | 116 +------------- BauSystem/build.gradle.kts | 7 - 6 files changed, 105 insertions(+), 279 deletions(-) delete mode 100644 AccessWidener/src/main/java/de/steamwar/AccessWidenerScanner.java create mode 100644 AccessWidener/src/main/java/de/steamwar/Utils.java diff --git a/AccessWidener/src/main/java/de/steamwar/AccessWidenerScanner.java b/AccessWidener/src/main/java/de/steamwar/AccessWidenerScanner.java deleted file mode 100644 index 70d2c0c9..00000000 --- a/AccessWidener/src/main/java/de/steamwar/AccessWidenerScanner.java +++ /dev/null @@ -1,145 +0,0 @@ -/* - * This file is a part of the SteamWar software. - * - * Copyright (C) 2026 SteamWar.de-Serverteam - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU Affero 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 Affero General Public License for more details. - * - * You should have received a copy of the GNU Affero General Public License - * along with this program. If not, see . - */ - -package de.steamwar; - -import java.io.File; -import java.io.IOException; -import java.io.InputStream; -import java.lang.instrument.Instrumentation; -import java.lang.reflect.Field; -import java.net.URL; -import java.net.URLClassLoader; -import java.nio.file.Path; -import java.util.*; -import java.util.logging.Logger; -import java.util.zip.ZipEntry; -import java.util.zip.ZipInputStream; - -/** - * Scans all plugin ClassLoaders for "plugin.accesswidener" resources - * and returns the parsed entries. - */ -public final class AccessWidenerScanner { - - private static final Logger LOG = Logger.getLogger("AccessWidenerScanner"); - - private AccessWidenerScanner() { - } - - /** - * Scans every ClassLoader visible from the already-loaded classes for - */ - public static List scanAll(Instrumentation inst) { - List allEntries = new ArrayList<>(); - Set seen = Collections.newSetFromMap(new IdentityHashMap<>()); - - for (Class clazz : inst.getAllLoadedClasses()) { - ClassLoader cl = clazz.getClassLoader(); - if (cl == null) continue; // bootstrap — skip - if (!seen.add(cl)) continue; // already processed - if (!isPluginClassLoader(cl)) continue; - - allEntries.addAll(scanClassLoader(cl)); - } - - return allEntries; - } - - /** - * Uses getResources() so it finds ALL matching files on the loader's classpath. - */ - public static List scanClassLoader(ClassLoader cl) { - List entries = new ArrayList<>(); - - try { - for (URL url : findAccessWideners(cl)) { - try (InputStream in = url.openStream()) { - List parsed = AccessWidenerParser.parse(in); - LOG.info("[AccessWidener] Loaded " + parsed.size() + " entries from " + url); - entries.addAll(parsed); - } catch (IOException e) { - LOG.warning("[AccessWidener] Failed to read " + url + ": " + e.getMessage()); - } - } - } catch (IOException e) { - LOG.warning("[AccessWidener] Failed to scan " + cl + ": " + e.getMessage()); - } - - return entries; - } - - public static List findAccessWideners(ClassLoader cl) throws IOException { - List results = new ArrayList<>(); - - // Standard path — works on most Paper versions - if (cl instanceof URLClassLoader urlCl) { - return scanUrls(urlCl.getURLs()); - } - - // Newer Paper — PluginClassLoader stores the jar as a field - try { - // Try common field names used across Paper versions - for (String fieldName : List.of("file", "jarFile", "pluginJar", "source")) { - try { - Field f = cl.getClass().getDeclaredField(fieldName); - f.setAccessible(true); - Object value = f.get(cl); - if (value instanceof File file) { - return scanUrls(new URL[]{ file.toURI().toURL() }); - } - if (value instanceof Path path) { - return scanUrls(new URL[]{ path.toUri().toURL() }); - } - } catch (NoSuchFieldException ignored) {} - } - } catch (Exception e) { - LOG.warning("[AccessWidener] Could not extract JAR path from " + cl + ": " + e.getMessage()); - } - - return results; - } - - private static List scanUrls(URL[] urls) throws IOException { - List results = new ArrayList<>(); - for (URL url : urls) { - if (!url.getPath().endsWith(".jar")) continue; - try (ZipInputStream zip = new ZipInputStream(url.openStream())) { - ZipEntry entry; - while ((entry = zip.getNextEntry()) != null) { - if (entry.getName().endsWith(".accesswidener")) { - results.add(new URL("jar:" + url + "!/" + entry.getName())); - } - } - } - } - return results; - } - - /** - * Returns true if the classloader looks like a Paper plugin classloader. - * Checks by name so we don't need a direct dependency on Paper internals. - */ - public static boolean isPluginClassLoader(ClassLoader cl) { - String name = cl.getClass().getName(); - return name.contains("PluginClassLoader") // legacy Paper / Spigot - || name.contains("PaperPluginLoader") // Paper 1.20.5+ - || name.contains("PaperSimplePluginManager"); // just in case - } -} diff --git a/AccessWidener/src/main/java/de/steamwar/Agent.java b/AccessWidener/src/main/java/de/steamwar/Agent.java index a786fed8..6558508c 100644 --- a/AccessWidener/src/main/java/de/steamwar/Agent.java +++ b/AccessWidener/src/main/java/de/steamwar/Agent.java @@ -19,7 +19,11 @@ package de.steamwar; +import java.io.File; +import java.io.IOException; import java.lang.instrument.Instrumentation; +import java.util.ArrayList; +import java.util.List; import java.util.logging.Logger; /** @@ -38,14 +42,11 @@ import java.util.logging.Logger; */ public class Agent { private Agent() { - /* This utility class should not be instantiated */ + throw new IllegalStateException("Utility class"); } private static final Logger LOG = Logger.getLogger("AccessWidenerAgent"); - // Exposed so tests or other code can inspect the live transformer - static volatile WideningTransformer transformer; - // -javaagent: startup public static void premain(String args, Instrumentation inst) { init(inst); @@ -54,13 +55,22 @@ public class Agent { private static void init(Instrumentation inst) { LOG.info("[AccessWidener] Agent initialising."); - WideningTransformer t = new WideningTransformer(inst); - transformer = t; - - // --- Phase 2: register transformer for future class loads --- - // canRetransform=true so we can call retransformClasses() later - inst.addTransformer(t, true); + List entries = new ArrayList<>(); + File file = new File(new File(".").getAbsoluteFile(), "plugins/"); + File[] files = file.listFiles(); + if (files == null) files = new File[0]; + for (File jarFile : files) { + if (!jarFile.isFile()) continue; + if (!jarFile.getName().endsWith(".jar")) continue; + try { + entries.addAll(Utils.findAndParseAccessWideners(jarFile.toPath())); + } catch (IOException e) { + LOG.warning("Failed to parse access wideners from " + jarFile.getAbsolutePath()); + } + } + LOG.info("[AccessWidener] Loaded " + entries.size() + " access wideners."); + inst.addTransformer(new WideningTransformer(entries), false); LOG.info("[AccessWidener] Agent ready."); } } diff --git a/AccessWidener/src/main/java/de/steamwar/ClassPatcher.java b/AccessWidener/src/main/java/de/steamwar/ClassPatcher.java index 3e640694..a5549762 100644 --- a/AccessWidener/src/main/java/de/steamwar/ClassPatcher.java +++ b/AccessWidener/src/main/java/de/steamwar/ClassPatcher.java @@ -19,10 +19,12 @@ package de.steamwar; -import org.objectweb.asm.*; +import org.objectweb.asm.ClassReader; +import org.objectweb.asm.ClassWriter; import java.util.List; import java.util.Set; +import java.util.logging.Logger; import java.util.stream.Collectors; /** @@ -33,6 +35,8 @@ import java.util.stream.Collectors; */ public class ClassPatcher { + private static final Logger LOG = Logger.getLogger("ClassPatcher"); + private final List entries; /** Pre-computed set of targeted internal names for fast filtering. */ @@ -46,18 +50,22 @@ public class ClassPatcher { } /** - * Patches {@code classBytes} if {@code internalName} is targeted. + * Patches {@code classBytes} if {@code className} is targeted. * * @return patched bytes, or {@code null} if no changes were needed */ - public byte[] patch(String internalName, byte[] classBytes) { - if (!targets.contains(internalName)) return null; + public byte[] patch(String className, byte[] classBytes) { + if (!targets.contains(className)) return null; - ClassReader cr = new ClassReader(classBytes); - // COMPUTE_FRAMES would require the full classpath; we only touch flags so 0 is fine - ClassWriter cw = new ClassWriter(cr, 0); - cr.accept(new ClassTransformer(cw, internalName, entries), 0); - return cw.toByteArray(); + try { + ClassReader cr = new ClassReader(classBytes); + ClassWriter cw = new ClassWriter(cr, 0); + cr.accept(new ClassTransformer(cw, className, entries), ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES); + return cw.toByteArray(); + } catch (Exception e) { + LOG.warning("[AccessWidener] Failed to transform " + className + ": " + e.getMessage()); + return null; + } } } diff --git a/AccessWidener/src/main/java/de/steamwar/Utils.java b/AccessWidener/src/main/java/de/steamwar/Utils.java new file mode 100644 index 00000000..1a5bc541 --- /dev/null +++ b/AccessWidener/src/main/java/de/steamwar/Utils.java @@ -0,0 +1,60 @@ +/* + * This file is a part of the SteamWar software. + * + * Copyright (C) 2026 SteamWar.de-Serverteam + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero 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 Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see . + */ + +package de.steamwar; + +import java.io.IOException; +import java.io.InputStream; +import java.nio.file.Path; +import java.util.ArrayList; +import java.util.Enumeration; +import java.util.List; +import java.util.logging.Logger; +import java.util.zip.ZipEntry; +import java.util.zip.ZipFile; + +public class Utils { + + private static final Logger LOG = Logger.getLogger("AccessWidenerAgent"); + + private Utils() { + throw new IllegalStateException("Utility class"); + } + + public static List findAndParseAccessWideners(Path jarPath) throws IOException { + List results = new ArrayList<>(); + + try (ZipFile zip = new ZipFile(jarPath.toFile())) { + Enumeration entries = zip.entries(); + while (entries.hasMoreElements()) { + ZipEntry entry = entries.nextElement(); + if (entry.isDirectory() || !entry.getName().endsWith(".accesswidener")) continue; + + try (InputStream in = zip.getInputStream(entry)) { + results.addAll(AccessWidenerParser.parse(in)); + } catch (IOException e) { + LOG.warning("[AccessWidener] Failed to parse " + entry.getName() + + " in " + jarPath.getFileName() + ": " + e.getMessage()); + } + } + } + + return results; + } +} diff --git a/AccessWidener/src/main/java/de/steamwar/WideningTransformer.java b/AccessWidener/src/main/java/de/steamwar/WideningTransformer.java index dd14a9a0..2215c769 100644 --- a/AccessWidener/src/main/java/de/steamwar/WideningTransformer.java +++ b/AccessWidener/src/main/java/de/steamwar/WideningTransformer.java @@ -19,17 +19,9 @@ package de.steamwar; -import org.objectweb.asm.ClassReader; -import org.objectweb.asm.ClassWriter; - import java.lang.instrument.ClassFileTransformer; -import java.lang.instrument.Instrumentation; -import java.lang.instrument.UnmodifiableClassException; import java.security.ProtectionDomain; -import java.util.*; -import java.util.concurrent.CopyOnWriteArrayList; -import java.util.logging.Logger; -import java.util.stream.Collectors; +import java.util.List; /** * Transforms class bytecode to apply access widening rules. @@ -39,111 +31,19 @@ import java.util.stream.Collectors; */ public class WideningTransformer implements ClassFileTransformer { - private static final Logger LOG = Logger.getLogger("WidenerTransformer"); + private final ClassPatcher patcher; - private final Instrumentation instrumentation; - - /** - * All entries collected across all plugins. Thread-safe for concurrent plugin loads. - */ - private final List entries = new CopyOnWriteArrayList<>(); - - /** - * ClassLoaders we have already scanned, to avoid re-scanning. - */ - private final Set scannedLoaders = Collections.synchronizedSet(Collections.newSetFromMap(new IdentityHashMap<>())); - - public WideningTransformer(Instrumentation instrumentation) { - this.instrumentation = instrumentation; + public WideningTransformer(List entries) { + patcher = new ClassPatcher(entries); } - /** - * Add entries — used during initial scan before the transformer is registered. - */ - public void addEntries(List newEntries) { - entries.addAll(newEntries); - } - - // ------------------------------------------------------------------------- - // ClassFileTransformer - // ------------------------------------------------------------------------- - @Override public byte[] transform(ClassLoader loader, String className, Class classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) { - - // Check for new plugin classloaders we haven't seen yet - if (loader != null && AccessWidenerScanner.isPluginClassLoader(loader) && scannedLoaders.add(loader)) { - onNewPluginClassLoader(loader); - } - - // No entries for this class — skip transformation entirely - if (className == null) return classfileBuffer; - boolean relevant = entries.stream().anyMatch(e -> e.targets(className)); - if (!relevant) return classfileBuffer; - - // Apply widening via ASM - try { - ClassReader cr = new ClassReader(classfileBuffer); - ClassWriter cw = new ClassWriter(cr, 0); - cr.accept(new ClassTransformer(cw, className, entries), 0); - return cw.toByteArray(); - } catch (Exception e) { - LOG.warning("[AccessWidener] Failed to transform " + className + ": " + e.getMessage()); + byte[] result = patcher.patch(className, classfileBuffer); + if (result == null) { return classfileBuffer; - } - } - - // ------------------------------------------------------------------------- - // New ClassLoader detection - // ------------------------------------------------------------------------- - - private void onNewPluginClassLoader(ClassLoader loader) { - List newEntries = AccessWidenerScanner.scanClassLoader(loader); - if (newEntries.isEmpty()) return; - - entries.addAll(newEntries); - LOG.info("[AccessWidener] Picked up " + newEntries.size() + " new entr" + (newEntries.size() == 1 ? "y" : "ies") + " from " + loader); - - // Retransform already-loaded classes that are now targeted - scheduleRetransform(newEntries); - } - - /** - * Retransformation cannot be called from within a transform() call, - * so we dispatch it to a short-lived daemon thread. - */ - private void scheduleRetransform(List newEntries) { - Set targets = newEntries.stream().map(e -> e.target().replace('/', '.')).collect(Collectors.toSet()); - - Thread t = new Thread(() -> retransform(targets), "access-widener-retransform"); - t.setDaemon(true); - t.start(); - } - - private void retransform(Set dotNames) { - List toRetransform = Arrays.stream(instrumentation.getAllLoadedClasses()) - .filter(c -> dotNames.contains(c.getName())) - .filter(instrumentation::isModifiableClass) - .collect(Collectors.toList()); - - if (toRetransform.isEmpty()) return; - - LOG.info("[AccessWidener] Retransforming " + toRetransform.size() + " class(es)."); - List failed = new ArrayList<>(); - - for (Class clazz : toRetransform) { - try { - instrumentation.retransformClasses(clazz); - } catch (UnmodifiableClassException | UnsupportedOperationException e) { - failed.add(clazz.getName()); - } - } - - if (!failed.isEmpty()) { - LOG.warning("[AccessWidener] The following classes were already loaded before the agent" - + " and cannot be retransformed. Add -javaagent: to your start script" - + " to fix this:"); - failed.forEach(name -> LOG.warning(" - " + name)); + } else { + return result; } } } diff --git a/BauSystem/build.gradle.kts b/BauSystem/build.gradle.kts index b6180f3f..aa03f184 100644 --- a/BauSystem/build.gradle.kts +++ b/BauSystem/build.gradle.kts @@ -20,22 +20,15 @@ plugins { `java-library` alias(libs.plugins.shadow) - id("io.papermc.paperweight.userdev") version "1.7.1" } tasks.build { finalizedBy(tasks.shadowJar) } -repositories { - maven("https://repo.papermc.io/repository/maven-public/") -} - dependencies { implementation(project(":BauSystem:BauSystem_RegionFixed")) implementation(project(":BauSystem:BauSystem_Main")) - - paperweight.paperDevBundle("1.21.1-R0.1-SNAPSHOT") } tasks.register("DevBau21") {