Inject a fake map into the super PermissionAttachment instance to fix compat with plugins using reflection to change attachment data (#528)

bukkit/src/main/java/me/lucko/luckperms/bukkit/model/LPPermissionAttachment.java

@@ -28,17 +28,25 @@ package me.lucko.luckperms.bukkit.model;
 import lombok.Getter;
 import lombok.Setter;
 
+import com.google.common.base.Preconditions;
+
+import me.lucko.luckperms.api.Node;
 import me.lucko.luckperms.common.config.ConfigKeys;
+import me.lucko.luckperms.common.model.User;
 import me.lucko.luckperms.common.node.ImmutableTransientNode;
 import me.lucko.luckperms.common.node.NodeFactory;
 
+import org.bukkit.permissions.PermissibleBase;
 import org.bukkit.permissions.PermissionAttachment;
 import org.bukkit.permissions.PermissionRemovedExecutor;
 import org.bukkit.plugin.Plugin;
 
+import java.lang.reflect.Field;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * PermissionAttachment for LuckPerms.
@@ -47,6 +55,23 @@ import java.util.Map;
  */
 public class LPPermissionAttachment extends PermissionAttachment {
 
+    /**
+     * The field in PermissionAttachment where the attachments applied permissions
+     * are *usually* held.
+     */
+    private static final Field PERMISSION_ATTACHMENT_PERMISSIONS_FIELD;
+
+    static {
+        Field permissionAttachmentPermissionsField;
+        try {
+            permissionAttachmentPermissionsField = PermissibleBase.class.getDeclaredField("permissions");
+            permissionAttachmentPermissionsField.setAccessible(true);
+        } catch (NoSuchFieldException e) {
+            throw new RuntimeException(e);
+        }
+        PERMISSION_ATTACHMENT_PERMISSIONS_FIELD = permissionAttachmentPermissionsField;
+    }
+
     /**
      * The parent LPPermissible
      */
@@ -79,6 +104,8 @@ public class LPPermissionAttachment extends PermissionAttachment {
         super(DummyPlugin.INSTANCE, null);
         this.permissible = permissible;
         this.owner = owner;
+
+        injectFakeMap();
     }
 
     public LPPermissionAttachment(LPPermissible permissible, PermissionAttachment bukkit) {
@@ -88,12 +115,41 @@ public class LPPermissionAttachment extends PermissionAttachment {
 
         // copy
         perms.putAll(bukkit.getPermissions());
+
+        injectFakeMap();
     }
 
+    /**
+     * Injects a fake 'permissions' map into the superclass, for (clever/dumb??) plugins
+     * which attempt to modify attachment permissions using reflection to get around the slow bukkit
+     * behaviour in the base PermissionAttachment implementation.
+     *
+     * The fake map proxies calls back to the methods on this attachment
+     */
+    private void injectFakeMap() {
+        // inner class - this proxies calls back to us
+        FakeBackingMap fakeMap = new FakeBackingMap();
+
+        try {
+            // what's this doing, ay?
+            // the field we need to modify is in the superclass - it's set to private
+            // so we have to use reflection to modify it.
+            PERMISSION_ATTACHMENT_PERMISSIONS_FIELD.set(this, fakeMap);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    /**
+     * Hooks this attachment with the parent {@link User} instance.
+     */
     public void hook() {
         hooked = true;
         permissible.attachments.add(this);
         for (Map.Entry<String, Boolean> entry : perms.entrySet()) {
+            if (entry.getKey() == null || entry.getKey().isEmpty()) {
+                continue;
+            }
             setPermissionInternal(entry.getKey(), entry.getValue());
         }
     }
@@ -103,9 +159,20 @@ public class LPPermissionAttachment extends PermissionAttachment {
             return;
         }
 
-        ImmutableTransientNode node = ImmutableTransientNode.of(NodeFactory.make(name, value), this);
+        // construct a node for the permission being set
-        if (permissible.getUser().setTransientPermission(node).asBoolean()) {
+        // we use the servers static context to *try* to ensure that the node will apply
-            permissible.getUser().getRefreshBuffer().request();
+        Node node = NodeFactory.newBuilder(name)
+                .setValue(value)
+                .withExtraContext(permissible.getPlugin().getContextManager().getStaticContext())
+                .build();
+
+        // convert the constructed node to a transient node instance to refer back to this attachment
+        ImmutableTransientNode transientNode = ImmutableTransientNode.of(node, this);
+
+        // set the transient node
+        User user = permissible.getUser();
+        if (user.setTransientPermission(transientNode).asBoolean()) {
+            user.getRefreshBuffer().request();
         }
     }
 
@@ -114,8 +181,18 @@ public class LPPermissionAttachment extends PermissionAttachment {
             return;
         }
 
-        if (permissible.getUser().removeIfTransient(n -> n instanceof ImmutableTransientNode && ((ImmutableTransientNode) n).getOwner() == this && n.getPermission().equals(name))) {
+        // remove transient permissions from the holder which were added by this attachment & equal the permission
-            permissible.getUser().getRefreshBuffer().request();
+        User user = permissible.getUser();
+        if (user.removeIfTransient(n -> n instanceof ImmutableTransientNode && ((ImmutableTransientNode) n).getOwner() == this && n.getPermission().equals(name))) {
+            user.getRefreshBuffer().request();
+        }
+    }
+
+    private void clearInternal() {
+        // remove all transient permissions added by this attachment
+        User user = permissible.getUser();
+        if (user.removeIfTransient(n -> n instanceof ImmutableTransientNode && ((ImmutableTransientNode) n).getOwner() == this)) {
+            user.getRefreshBuffer().request();
         }
     }
 
@@ -125,14 +202,15 @@ public class LPPermissionAttachment extends PermissionAttachment {
             return false;
         }
 
-        if (permissible.getUser().removeIfTransient(n -> n instanceof ImmutableTransientNode && ((ImmutableTransientNode) n).getOwner() == this)) {
+        // clear the internal permissions
-            permissible.getUser().getRefreshBuffer().request();
+        clearInternal();
-        }
 
+        // run the callback
         if (removalCallback != null) {
             removalCallback.attachmentRemoved(this);
         }
 
+        // unhook from the permissible
         hooked = false;
         permissible.attachments.remove(this);
         return true;
@@ -140,34 +218,48 @@ public class LPPermissionAttachment extends PermissionAttachment {
 
     @Override
     public void setPermission(String name, boolean value) {
-        Boolean previous = perms.put(name, value);
+        Preconditions.checkNotNull(name, "name is null");
+        Preconditions.checkArgument(!name.isEmpty(), "name is empty");
+
+        String permission = name.toLowerCase();
+
+        Boolean previous = perms.put(permission, value);
         if (previous != null && previous == value) {
             return;
         }
 
+        // if we're not hooked, thn don't actually apply the change
+        // it will get applied on hook - if that ever happens
         if (!hooked) {
             return;
         }
 
         if (previous != null) {
-            unsetPermissionInternal(name);
+            unsetPermissionInternal(permission);
         }
 
-        setPermissionInternal(name, value);
+        setPermissionInternal(permission, value);
     }
 
     @Override
     public void unsetPermission(String name) {
-        Boolean previous = perms.remove(name);
+        Preconditions.checkNotNull(name, "name is null");
+        Preconditions.checkArgument(!name.isEmpty(), "name is empty");
+
+        String permission = name.toLowerCase();
+
+        Boolean previous = perms.remove(permission);
         if (previous == null) {
             return;
         }
 
+        // if we're not hooked, thn don't actually apply the change
+        // it will get applied on hook - if that ever happens
         if (!hooked) {
             return;
         }
 
-        unsetPermissionInternal(name);
+        unsetPermissionInternal(permission);
     }
 
     @Override
@@ -189,4 +281,116 @@ public class LPPermissionAttachment extends PermissionAttachment {
     public int hashCode() {
         return System.identityHashCode(this);
     }
+
+    /**
+     * A fake map to be injected into the superclass. This implementation simply
+     * proxies calls back to this attachment instance.
+     *
+     * Some (clever/dumb??) plugins attempt to modify attachment permissions using reflection
+     * to get around the slow bukkit behaviour in the base PermissionAttachment implementation.
+     *
+     * An instance of this map is injected into the super instance so these plugins continue
+     * to work with LuckPerms.
+     */
+    private final class FakeBackingMap implements Map<String, Boolean> {
+
+        @Override
+        public Boolean put(String key, Boolean value) {
+
+            // grab the previous result, so we can still satisfy the method signature of Map
+            Boolean previous = perms.get(key);
+
+            // proxy the call back through the PermissionAttachment instance
+            setPermission(key, value);
+
+            // return the previous value
+            return previous;
+        }
+
+        @Override
+        public Boolean remove(Object key) {
+            // we only accept string keys
+            if (!(key instanceof String)) {
+                return null;
+            }
+
+            String permission = ((String) key);
+
+            // grab the previous result, so we can still satisfy the method signature of Map
+            Boolean previous = perms.get(permission);
+
+            // proxy the call back through the PermissionAttachment instance
+            unsetPermission(permission);
+
+            // return the previous value
+            return previous;
+        }
+
+        @Override
+        public void putAll(Map<? extends String, ? extends Boolean> m) {
+            for (Map.Entry<? extends String, ? extends Boolean> entry : m.entrySet()) {
+                put(entry.getKey(), entry.getValue());
+            }
+        }
+
+        @Override
+        public void clear() {
+            // remove the permissions which have already been applied
+            if (hooked) {
+                clearInternal();
+            }
+
+            // clear the backing map
+            perms.clear();
+        }
+
+        @Override
+        public int size() {
+            // return the size of the permissions map - probably the most accurate value we have
+            return perms.size();
+        }
+
+        @Override
+        public boolean isEmpty() {
+            // return if the permissions map is empty - again probably the most accurate thing
+            // we can return
+            return perms.isEmpty();
+        }
+
+        @Override
+        public boolean containsKey(Object key) {
+            // just proxy
+            return perms.containsKey(key);
+        }
+
+        @Override
+        public boolean containsValue(Object value) {
+            // just proxy
+            return perms.containsValue(value);
+        }
+
+        @Override
+        public Boolean get(Object key) {
+            // just proxy
+            return perms.get(key);
+        }
+
+        @Override
+        public Set<String> keySet() {
+            // just proxy
+            return perms.keySet();
+        }
+
+        @Override
+        public Collection<Boolean> values() {
+            // just proxy
+            return perms.values();
+        }
+
+        @Override
+        public Set<Entry<String, Boolean>> entrySet() {
+            // just proxy
+            return perms.entrySet();
+        }
+    }
 }