Extending plugin interface.

This is for feature parity with the older interface, and remains
experimental for now.

src/EventHandler.cc

@@ -13,6 +13,7 @@ EventHandler::EventHandler(const char* arg_name)
 	type = 0;
 	error_handler = false;
 	enabled = true;
+	generate_always = false;
 	}
 
 EventHandler::~EventHandler()
@@ -23,7 +24,9 @@ EventHandler::~EventHandler()
 
 EventHandler::operator bool() const
 	{
-	return enabled && ((local && local->HasBodies()) || receivers.length());
+	return enabled && ((local && local->HasBodies())
+			   || receivers.length()
+			   || generate_always);
 	}
 
 FuncType* EventHandler::FType()

src/EventHandler.h

@@ -43,6 +43,11 @@ public:
 
 	void SetEnable(bool arg_enable)	{ enabled = arg_enable; }
 
+	// Flags the event as interesting even if there is no body defined. In
+	// particular, this will then still pass the event on to plugins.
+	void SetGenerateAlways()	{ generate_always = true; }
+	bool GenerateAlways()	{ return generate_always; }
+
 	// We don't serialize the handler(s) itself here, but
 	// just the reference to it.
 	bool Serialize(SerialInfo* info) const;
@@ -57,6 +62,7 @@ private:
 	bool used;		// this handler is indeed used somewhere
 	bool enabled;
 	bool error_handler;	// this handler reports error messages.
+    bool generate_always;
 
 	declare(List, SourceID);
 	typedef List(SourceID) receiver_list;

src/Obj.cc

@@ -7,6 +7,7 @@
 #include "Obj.h"
 #include "Serializer.h"
 #include "File.h"
+#include "plugin/Manager.h"
 
 Location no_location("<no location>", 0, 0, 0, 0);
 Location start_location("<start uninitialized>", 0, 0, 0, 0);
@@ -92,6 +93,11 @@ int BroObj::suppress_errors = 0;
 
 BroObj::~BroObj()
 	{
+	if ( notify_plugins )
+		{
+                PLUGIN_HOOK_VOID(HOOK_BRO_OBJ_DTOR, HookBroObjDtor(this));
+		}
+
 	delete location;
 	}
 

src/Obj.h

@@ -92,6 +92,7 @@ public:
 		{
 		ref_cnt = 1;
 		in_ser_cache = false;
+		notify_plugins = false;
 
 		// A bit of a hack.  We'd like to associate location
 		// information with every object created when parsing,
@@ -151,6 +152,9 @@ public:
 	// extend compound objects such as statement lists.
 	virtual void UpdateLocationEndInfo(const Location& end);
 
+	// Enable notification of plugins when this objects gets destroyed.
+	void NotifyPluginsOnDtor()	{ notify_plugins = true; }
+
 	int RefCnt() const	{ return ref_cnt; }
 
 	// Helper class to temporarily suppress errors
@@ -181,6 +185,7 @@ private:
 	friend inline void Ref(BroObj* o);
 	friend inline void Unref(BroObj* o);
 
+	bool notify_plugins;
 	int ref_cnt;
 
 	// If non-zero, do not print runtime errors.  Useful for

src/plugin/Manager.cc

@@ -443,6 +443,16 @@ void Manager::DisableHook(HookType hook, Plugin* plugin)
 		}
 	}
 
+void Manager::RequestEvent(EventHandlerPtr handler, Plugin* plugin)
+	{
+	DBG_LOG(DBG_PLUGINS, "Plugin %s requested event %s", Name(), handler->Name());
+	handler->GenerateAlways();
+	}
+
+void Manager::RequestBroObjDtor(BroObj* obj, Plugin* plugin)
+	{
+	}
+
 int Manager::HookLoadFile(const string& file)
 	{
 	HookArgumentList args;
@@ -522,7 +532,7 @@ bool Manager::HookQueueEvent(Event* event) const
 		{
 		Plugin* p = (*i).second;
 
-		if ( p->HookQueueEvent(event) ) 
+		if ( p->HookQueueEvent(event) )
 			{
 			result = true;
 			break;
@@ -577,6 +587,29 @@ void Manager::HookUpdateNetworkTime(double network_time) const
 		MetaHookPost(HOOK_UPDATE_NETWORK_TIME, args, HookArgument());
 	}
 
+void Manager::HookBroObjDtor(void* obj) const
+	{
+	HookArgumentList args;
+
+        if ( HavePluginForHook(META_HOOK_PRE) )
+		{
+		args.push_back(obj);
+		MetaHookPre(HOOK_BRO_OBJ_DTOR, args);
+		}
+
+	hook_list* l = hooks[HOOK_BRO_OBJ_DTOR];
+
+	for ( hook_list::iterator i = l->begin(); l && i != l->end(); i++ )
+		{
+		Plugin* p = (*i).second;
+		p->HookBroObjDtor(obj);
+		}
+
+	if ( HavePluginForHook(META_HOOK_POST) )
+		MetaHookPost(HOOK_BRO_OBJ_DTOR, args, HookArgument());
+
+	}
+
 void Manager::MetaHookPre(HookType hook, const HookArgumentList& args) const
 	{
 	hook_list* l = hooks[HOOK_CALL_FUNCTION];

src/plugin/Manager.h

@@ -15,7 +15,7 @@ namespace plugin {
 // Macros that trigger a plugin hook. We put this into macros to short-cut
 // the code for the most common case that no plugin defines the hook.
 #define PLUGIN_HOOK_WITH_RESULT(hook, method_call, default_result) \
-	(plugin_mgr->HavePluginForHook(plugin::hook) ? plugin_mgr->method_call : (default_result))
+   (plugin_mgr->HavePluginForHook(::plugin::hook) ? plugin_mgr->method_call : (default_result))
 
 #define PLUGIN_HOOK_VOID(hook, method_call) \
 	if ( plugin_mgr->HavePluginForHook(plugin::hook) ) plugin_mgr->method_call;
@@ -160,6 +160,27 @@ public:
 	 */
 	void DisableHook(HookType hook, Plugin* plugin);
 
+	/**
+	 * Register interest in an event. The event will then be raised, and
+	 * hence passed to the plugin, even if there no handler defined.
+	 *
+	 * @param handler The event being interested in.
+	 *
+	 * @param plugin The plugin expressing interest.
+	 */
+	void RequestEvent(EventHandlerPtr handler, Plugin* plugin);
+
+	/**
+	 * Register interest in the destruction of a BroObj instance. When
+	 * Bro's reference counting triggers the objects destructor to run,
+	 * the \a HookBroObjDtor will be called.
+	 *
+	 * @param handler The object being interested in.
+	 *
+	 * @param plugin The plugin expressing interest.
+	 */
+	void RequestBroObjDtor(BroObj* obj, Plugin* plugin);
+
 	// Hook entry functions.
 
 	/**
@@ -208,10 +229,16 @@ public:
 	void HookUpdateNetworkTime(double network_time) const;
 
 	/**
-	 * Hooks that informs plugins that the event queue is being drained.
+	 * Hook that informs plugins that the event queue is being drained.
 	 */
 	void HookDrainEvents() const;
 
+	/**
+	 * Hook that informs plugins that an BroObj is being destroyed. Will be
+	 * called only for objects that a plugin has expressed interest in.
+	 */
+	void HookBroObjDtor(void* obj) const;
+
 	/**
 	 * Internal method that registers a freshly instantiated plugin with
 	 * the manager.

src/plugin/Plugin.cc

@@ -22,6 +22,7 @@ const char* plugin::hook_name(HookType h)
 		"QueueEvent",
 		"DrainEvents",
 		"UpdateNetworkTime",
+		"BroObjDtor",
 		// MetaHooks
 		"MetaHookPre",
 		"MetaHookPost",
@@ -32,6 +33,13 @@ const char* plugin::hook_name(HookType h)
 	return hook_names[int(h)];
 	}
 
+Configuration::Configuration()
+	{
+	name = "";
+	description = "";
+	api_version = BRO_PLUGIN_API_VERSION;
+	}
+
 BifItem::BifItem(const std::string& arg_id, Type arg_type)
 	{
 	id = arg_id;
@@ -119,6 +127,10 @@ void HookArgument::Describe(ODesc* d) const
 	case VOID:
 		d->Add("<void>");
 		break;
+
+	case VOIDP:
+		d->Add("<void ptr>");
+		break;
 	}
 	}
 
@@ -262,6 +274,16 @@ void Plugin::DisableHook(HookType hook)
 	plugin_mgr->DisableHook(hook, this);
 	}
 
+void Plugin::RequestEvent(EventHandlerPtr handler)
+	{
+	plugin_mgr->RequestEvent(handler, this);
+	}
+
+void Plugin::RequestBroObjDtor(BroObj* obj)
+	{
+	plugin_mgr->RequestBroObjDtor(obj, this);
+	}
+
 int Plugin::HookLoadFile(const std::string& file)
 	{
 	return -1;
@@ -285,6 +307,10 @@ void Plugin::HookUpdateNetworkTime(double network_time)
 	{
 	}
 
+void Plugin::HookBroObjDtor(void* obj)
+	{
+	}
+
 void Plugin::MetaHookPre(HookType hook, const HookArgumentList& args)
 	{
 	}

src/plugin/Plugin.h

@@ -33,6 +33,7 @@ enum HookType {
 	HOOK_QUEUE_EVENT,
 	HOOK_DRAIN_EVENTS,
 	HOOK_UPDATE_NETWORK_TIME,
+	HOOK_BRO_OBJ_DTOR,
 
 	// Meta hooks.
 	META_HOOK_PRE,
@@ -69,19 +70,11 @@ public:
 	std::string description;	//< A short textual description of the plugin. Mandatory.
 	VersionNumber version;		//< THe plugin's version. Optional.
 
-	Configuration()
+	Configuration();
-		{
-		// Note we inline this method here so that when plugins create an instance,
-		// *their* defaults will be used for the internal fields.
-		name = "";
-		description = "";
-		api_version = BRO_PLUGIN_API_VERSION;
-		}
 
 private:
 	friend class Plugin;
 	int api_version;	// Current BRO_PLUGIN_API_VERSION. Automatically set.
-
 };
 
 /**
@@ -141,7 +134,7 @@ class HookArgument
 {
 public:
 	enum Type {
-		BOOL, DOUBLE, EVENT, FUNC, INT, STRING, VAL, VAL_LIST, VOID
+		BOOL, DOUBLE, EVENT, FUNC, INT, STRING, VAL, VAL_LIST, VOID, VOIDP,
 	};
 
 	HookArgument()	{ type = VOID; }
@@ -153,6 +146,7 @@ public:
 	HookArgument(const std::string& a)	{ type = STRING; arg_string = a; }
 	HookArgument(const Val* a)	{ type = VAL; arg.val = a; }
 	HookArgument(const val_list* a)	{ type = VAL_LIST; arg.vals = a; }
+	HookArgument(void* p)	{ type = VOIDP; arg.voidp = p; }
 
 	bool AsBool() const	{ assert(type == BOOL); return arg.bool_; }
 	double AsDouble() const	{ assert(type == DOUBLE); return arg.double_; }
@@ -162,6 +156,7 @@ public:
 	const std::string& AsString() const	{ assert(type == STRING); return arg_string; }
 	const Val* AsVal() const	{ assert(type == VAL); return arg.val; }
 	const val_list* AsValList() const	{ assert(type == VAL_LIST); return arg.vals; }
+	const void* AsVoidPtr() const	{ assert(type == VOIDP); return arg.voidp; }
 
 	Type GetType() const	{ return type; }
 	void Describe(ODesc* d) const;
@@ -176,6 +171,7 @@ private:
 		int int_;
 		const Val* val;
 		const val_list* vals;
+		const void* voidp;
 	} arg;
 
 	std::string arg_string; // Outside union because it has dtor.
@@ -406,6 +402,23 @@ protected:
 	 */
 	hook_list EnabledHooks() const;
 
+	/**
+	 * Register interest in an event. The event will then be raised, and
+	 * hence passed to the plugin, even if there no handler defined.
+	 *
+	 * @param handler The object being interested in.
+	 */
+	void RequestEvent(EventHandlerPtr handler);
+
+	/**
+	 * Register interest in the destruction of a BroObj instance. When
+	 * Bro's reference counting triggers the objects destructor to run,
+	 * the \a HookBroObjDtor will be called.
+	 *
+	 * @param handler The object being interested in.
+	 */
+	void RequestBroObjDtor(BroObj* obj);
+
 	/**
 	 * Virtual method that can be overriden by derived class to provide
 	 * information about further script-level elements that the plugin
@@ -496,6 +509,18 @@ protected:
 	 */
 	virtual void HookUpdateNetworkTime(double network_time);
 
+	/**
+	 * Hook for destruction of objects registerd with
+	 * RequestBroObjDtor(). When Bro's reference counting triggers the
+	 * objects destructor to run, this method will be run. It may also
+	 * run for other objects that this plugin has not registered for.
+	 *
+	 * @param obj A pointer to the object being destroyed. Note that the
+	 * object is already considered invalid and the pointer must not be
+	 * dereferenced.
+	 */
+	virtual void HookBroObjDtor(void* obj);
+
 	// Meta hooks.
 
 	/**