8017196: Ensure Proxies are handled appropriately

Reviewed-by: dfuchs, jrose, jdn, ahgross, chegar

1 files changed, 48 insertions, 0 deletions

diff --git a/src/share/classes/sun/reflect/misc/ReflectUtil.java b/src/share/classes/sun/reflect/misc/ReflectUtil.java
index efd85fca9..1f871e8de 100644
--- a/src/share/classes/sun/reflect/misc/ReflectUtil.java
+++ b/src/share/classes/sun/reflect/misc/ReflectUtil.java
@@ -26,8 +26,10 @@
 
 package sun.reflect.misc;
 
+import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.lang.reflect.Proxy;
+import java.util.Arrays;
 import sun.reflect.Reflection;
 
 public final class ReflectUtil {
@@ -250,4 +252,50 @@ public final class ReflectUtil {
         String pkg = (i != -1) ? name.substring(0, i) : "";
         return Proxy.isProxyClass(cls) && !pkg.equals(PROXY_PACKAGE);
     }
+
+    /**
+     * Check if the given method is a method declared in the proxy interface
+     * implemented by the given proxy instance.
+     *
+     * @param proxy a proxy instance
+     * @param method an interface method dispatched to a InvocationHandler
+     *
+     * @throws IllegalArgumentException if the given proxy or method is invalid.
+     */
+    public static void checkProxyMethod(Object proxy, Method method) {
+        // check if it is a valid proxy instance
+        if (proxy == null || !Proxy.isProxyClass(proxy.getClass())) {
+            throw new IllegalArgumentException("Not a Proxy instance");
+}
+        if (Modifier.isStatic(method.getModifiers())) {
+            throw new IllegalArgumentException("Can't handle static method");
+        }
+
+        Class<?> c = method.getDeclaringClass();
+        if (c == Object.class) {
+            String name = method.getName();
+            if (name.equals("hashCode") || name.equals("equals") || name.equals("toString")) {
+                return;
+            }
+        }
+
+        if (isSuperInterface(proxy.getClass(), c)) {
+            return;
+        }
+
+        // disallow any method not declared in one of the proxy intefaces
+        throw new IllegalArgumentException("Can't handle: " + method);
+    }
+
+    private static boolean isSuperInterface(Class<?> c, Class<?> intf) {
+        for (Class<?> i : c.getInterfaces()) {
+            if (i == intf) {
+                return true;
+            }
+            if (isSuperInterface(i, intf)) {
+                return true;
+            }
+        }
+        return false;
+    }
 }