Address todos

patches/server/1046-Modify-library-loader-jars-bytecode.patch

@@ -6,31 +6,42 @@ Subject: [PATCH] Modify library loader jars bytecode
 
 diff --git a/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/BytecodeModifyingURLClassLoader.java b/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/BytecodeModifyingURLClassLoader.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..acd24b8d32b5debd987f463c0be0ac6bdfdd061f
+index 0000000000000000000000000000000000000000..405416dc3d1c8c58b4e0c880d8751ca319188f62
 --- /dev/null
 +++ b/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/BytecodeModifyingURLClassLoader.java
-@@ -0,0 +1,116 @@
+@@ -0,0 +1,185 @@
 +package io.papermc.paper.plugin.entrypoint.classloader;
 +
 +import io.papermc.paper.pluginremap.reflect.ReflectionRemapper;
 +import java.io.IOException;
 +import java.io.InputStream;
++import java.io.UncheckedIOException;
++import java.net.JarURLConnection;
 +import java.net.URL;
 +import java.net.URLClassLoader;
 +import java.security.CodeSigner;
 +import java.security.CodeSource;
++import java.util.Map;
++import java.util.concurrent.ConcurrentHashMap;
 +import java.util.function.Function;
++import java.util.jar.Attributes;
 +import java.util.jar.Manifest;
++import org.checkerframework.checker.nullness.qual.Nullable;
 +import org.objectweb.asm.ClassReader;
 +import org.objectweb.asm.ClassVisitor;
 +import org.objectweb.asm.ClassWriter;
 +
++import static java.util.Objects.requireNonNullElse;
++
 +public final class BytecodeModifyingURLClassLoader extends URLClassLoader {
 +    static {
 +        ClassLoader.registerAsParallelCapable();
 +    }
 +
++    private static final Object MISSING_MANIFEST = new Object();
++
 +    private final Function<byte[], byte[]> modifier;
++    private final Map<String, Object> manifests = new ConcurrentHashMap<>();
 +
 +    public BytecodeModifyingURLClassLoader(
 +        final URL[] urls,
@@ -65,20 +76,8 @@ index 0000000000000000000000000000000000000000..acd24b8d32b5debd987f463c0be0ac6b
 +        if (url != null) {
 +            try {
 +                result = this.defineClass(name, url);
-+            } catch (IOException e) {
++            } catch (final IOException e) {
 +                throw new ClassNotFoundException(name, e);
-+            } catch (ClassFormatError e2) {
-+                /* TODO
-+                try {
-+                    final Throwable dataError = (Throwable) GET_DATA_ERROR.invoke(res);
-+                    if (dataError != null) {
-+                        e2.addSuppressed(dataError);
-+                    }
-+                } catch (final ReflectiveOperationException e) {
-+                    throw new RuntimeException(e);
-+                }
-+                 */
-+                throw e2;
 +            }
 +        } else {
 +            result = null;
@@ -94,26 +93,24 @@ index 0000000000000000000000000000000000000000..acd24b8d32b5debd987f463c0be0ac6b
 +        if (i != -1) {
 +            String pkgname = name.substring(0, i);
 +            // Check if package already loaded.
-+            Manifest man = null; // (Manifest) GET_MANIFEST.invoke(res); TODO
++            final @Nullable Manifest man = this.manifestFor(url);
-+            //if (GET_AND_VERIFY_PKG.invoke(this, pkgname, man, url) == null) { // todo
++            if (this.getAndVerifyPackage(pkgname, man, url) == null) {
-+            try {
++                try {
-+                if (man != null) {
++                    if (man != null) {
-+                    definePackage(pkgname, man, url);
++                        this.definePackage(pkgname, man, url);
-+                } else {
++                    } else {
-+                    definePackage(pkgname, null, null, null, null, null, null, null);
++                        this.definePackage(pkgname, null, null, null, null, null, null, null);
-+                }
++                    }
-+            } catch (IllegalArgumentException iae) {
++                } catch (IllegalArgumentException iae) {
-+                // parallel-capable class loaders: re-verify in case of a
++                    // parallel-capable class loaders: re-verify in case of a
-+                // race condition
++                    // race condition
-+                    /* TODO
++                    if (this.getAndVerifyPackage(pkgname, man, url) == null) {
-+                    if (GET_AND_VERIFY_PKG.invoke(this, pkgname, man, url) == null) {
 +                        // Should never happen
 +                        throw new AssertionError("Cannot find package " +
 +                            pkgname);
 +                    }
-+                     */
++                }
 +            }
-+            //} // todo
 +        }
 +        final byte[] bytes;
 +        try (final InputStream is = url.openStream()) {
@@ -123,7 +120,79 @@ index 0000000000000000000000000000000000000000..acd24b8d32b5debd987f463c0be0ac6b
 +        final byte[] modified = this.modifier.apply(bytes);
 +
 +        final CodeSource cs = new CodeSource(url, (CodeSigner[]) null);
-+        return defineClass(name, modified, 0, modified.length, cs);
++        return this.defineClass(name, modified, 0, modified.length, cs);
++    }
++
++    private Package getAndVerifyPackage(
++        String pkgname,
++        Manifest man, URL url
++    ) {
++        Package pkg = getDefinedPackage(pkgname);
++        if (pkg != null) {
++            // Package found, so check package sealing.
++            if (pkg.isSealed()) {
++                // Verify that code source URL is the same.
++                if (!pkg.isSealed(url)) {
++                    throw new SecurityException(
++                        "sealing violation: package " + pkgname + " is sealed");
++                }
++            } else {
++                // Make sure we are not attempting to seal the package
++                // at this code source URL.
++                if ((man != null) && this.isSealed(pkgname, man)) {
++                    throw new SecurityException(
++                        "sealing violation: can't seal package " + pkgname +
++                            ": already loaded");
++                }
++            }
++        }
++        return pkg;
++    }
++
++    private boolean isSealed(String name, Manifest man) {
++        Attributes attr = man.getAttributes(name.replace('.', '/').concat("/"));
++        String sealed = null;
++        if (attr != null) {
++            sealed = attr.getValue(Attributes.Name.SEALED);
++        }
++        if (sealed == null) {
++            if ((attr = man.getMainAttributes()) != null) {
++                sealed = attr.getValue(Attributes.Name.SEALED);
++            }
++        }
++        return "true".equalsIgnoreCase(sealed);
++    }
++
++    private @Nullable Manifest manifestFor(final URL url) throws IOException {
++        Manifest man = null;
++        if (url.getProtocol().equals("jar")) {
++            try {
++                final Object computedManifest = this.manifests.computeIfAbsent(jarName(url), $ -> {
++                    try {
++                        final Manifest m = ((JarURLConnection) url.openConnection()).getManifest();
++                        return requireNonNullElse(m, MISSING_MANIFEST);
++                    } catch (final IOException e) {
++                        throw new UncheckedIOException(e);
++                    }
++                });
++                if (computedManifest instanceof Manifest found) {
++                    man = found;
++                }
++            } catch (final UncheckedIOException e) {
++                throw e.getCause();
++            } catch (final IllegalArgumentException e) {
++                throw new IOException(e);
++            }
++        }
++        return man;
++    }
++
++    private static String jarName(final URL sourceUrl) {
++        final int exclamationIdx = sourceUrl.getPath().lastIndexOf('!');
++        if (exclamationIdx != -1) {
++            return sourceUrl.getPath().substring(0, exclamationIdx);
++        }
++        throw new IllegalArgumentException("Could not find jar for URL " + sourceUrl);
 +    }
 +}
 diff --git a/src/main/java/io/papermc/paper/plugin/loader/PaperClasspathBuilder.java b/src/main/java/io/papermc/paper/plugin/loader/PaperClasspathBuilder.java