Deobfuscate stacktraces in log messages, crash reports, and etc.

2021-06-20 18:19:09 -07:00
parent b0d7c2e971
commit 34407fe880
13 changed files with 466 additions and 17 deletions
--- a/paper-server/src/log4jPlugins/java/io/papermc/paper/logging/StacktraceDeobfuscatingRewritePolicy.java
+++ b/paper-server/src/log4jPlugins/java/io/papermc/paper/logging/StacktraceDeobfuscatingRewritePolicy.java
@@ -0,0 +1,66 @@
+package io.papermc.paper.logging;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.VarHandle;
+import org.apache.logging.log4j.core.Core;
+import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.appender.rewrite.RewritePolicy;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+import org.apache.logging.log4j.core.config.plugins.PluginFactory;
+import org.apache.logging.log4j.core.impl.Log4jLogEvent;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+@Plugin(
+    name = "StacktraceDeobfuscatingRewritePolicy",
+    category = Core.CATEGORY_NAME,
+    elementType = "rewritePolicy",
+    printObject = true
+)
+public final class StacktraceDeobfuscatingRewritePolicy implements RewritePolicy {
+    private static final MethodHandle DEOBFUSCATE_THROWABLE;
+
+    static {
+        try {
+            final Class<?> cls = Class.forName("io.papermc.paper.util.StacktraceDeobfuscator");
+            final MethodHandles.Lookup lookup = MethodHandles.lookup();
+            final VarHandle instanceHandle = lookup.findStaticVarHandle(cls, "INSTANCE", cls);
+            final Object deobfuscator = instanceHandle.get();
+            DEOBFUSCATE_THROWABLE = lookup
+                .unreflect(cls.getDeclaredMethod("deobfuscateThrowable", Throwable.class))
+                .bindTo(deobfuscator);
+        } catch (final ReflectiveOperationException ex) {
+            throw new IllegalStateException(ex);
+        }
+    }
+
+    private StacktraceDeobfuscatingRewritePolicy() {
+    }
+
+    @Override
+    public @NonNull LogEvent rewrite(final @NonNull LogEvent rewrite) {
+        final Throwable thrown = rewrite.getThrown();
+        if (thrown != null) {
+            deobfuscateThrowable(thrown);
+            return new Log4jLogEvent.Builder(rewrite)
+                .setThrownProxy(null)
+                .build();
+        }
+        return rewrite;
+    }
+
+    private static void deobfuscateThrowable(final Throwable thrown) {
+        try {
+            DEOBFUSCATE_THROWABLE.invoke(thrown);
+        } catch (final Error e) {
+            throw e;
+        } catch (final Throwable e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @PluginFactory
+    public static @NonNull StacktraceDeobfuscatingRewritePolicy createPolicy() {
+        return new StacktraceDeobfuscatingRewritePolicy();
+    }
+}