Communication must now be enabled explicitly.

The communication subsystem is now disabled until a new BiF,
enable_communication(), is called. The base scripts do this
automatically when either a Communication::Node is defined, or Bro is
asked to listen for incoming connections.

scripts/base/frameworks/communication/main.bro

@@ -108,6 +108,9 @@ const src_names = {
 event bro_init()
 	{
 	Log::create_stream(COMMUNICATION, [$columns=Info]);
+
+	if ( |nodes| > 0 )
+		enable_communication();
 	}
 
 function do_script_log_common(level: count, src: count, msg: string)

scripts/policy/frameworks/communication/listen-clear.bro

@@ -13,5 +13,6 @@ export {
 
 event bro_init() &priority=-10
 	{
+	enable_communication();
 	listen(listen_if_clear, listen_port_clear, F);
 	}

scripts/policy/frameworks/communication/listen-ssl.bro

@@ -14,5 +14,6 @@ export {
 
 event bro_init() &priority=-10
 	{
+	enable_communication();
 	listen(listen_if_ssl, listen_port_ssl, T);
 	}

src/Expr.cc

@@ -231,7 +231,6 @@ bool Expr::DoUnserialize(UnserialInfo* info)
 NameExpr::NameExpr(ID* arg_id) : Expr(EXPR_NAME)
 	{
 	id = arg_id;
-	ReferenceID();
 	SetType(id->Type()->Ref());
 
 	EventHandler* h = event_registry->Lookup(id->Name());
@@ -244,29 +243,6 @@ NameExpr::~NameExpr()
 	Unref(id);
 	}
 
-void NameExpr::ReferenceID()
-	{
-	// ### This is a hack. We check whether one of the remote serializer's
-	// built-in functions is referenced. If so, we activate the serializer.
-	// A better solution would be to either (1) a generic mechanism in
-	// which have (internal) attributes associated with identifiers and
-	// as we see references to the identifiers, we do bookkeeping
-	// associated with their attribute (so in this case the attribute
-	// would be "flag that inter-Bro communication is being used"),
-	// or (2) after the parse is done, we'd query whether these
-	// particular identifiers were seen, rather than doing the test
-	// here for every NameExpr we create.
-	if ( id->Type()->Tag() == TYPE_FUNC )
-		{
-		const char* const* builtins = remote_serializer->GetBuiltins();
-		while( *builtins )
-			{
-			if ( streq(id->Name(), *builtins++) )
-				using_communication = true;
-			}
-		}
-	}
-
 Expr* NameExpr::Simplify(SimplifyType simp_type)
 	{
 	if ( simp_type != SIMPLIFY_LHS && id->IsConst() )
@@ -393,8 +369,6 @@ bool NameExpr::DoUnserialize(UnserialInfo* info)
 	if ( ! id )
 		return false;
 
-	ReferenceID();
-
 	return true;
 	}
 

src/Expr.h

@@ -217,7 +217,6 @@ protected:
 	friend class Expr;
 	NameExpr()	{ id = 0; }
 
-	void ReferenceID();
 	void ExprDescribe(ODesc* d) const;
 
 	DECLARE_SERIAL(NameExpr);

src/RemoteSerializer.cc

@@ -3060,13 +3060,6 @@ bool RemoteSerializer::IsActive()
 	return false;
 	}
 
-
-const char* const* RemoteSerializer::GetBuiltins() const
-	{
-	static const char* builtins[] = { "connect", "listen", 0 };
-	return builtins;
-	}
-
 void RemoteSerializer::ReportError(const char* msg)
 	{
 	if ( current_peer && current_peer->phase != Peer::SETUP )

src/RemoteSerializer.h

@@ -128,10 +128,6 @@ public:
 	// Log some statistics.
 	void LogStats();
 
-	// Return a 0-terminated array of built-in functions which,
-	// when referenced, trigger the remote serializer's initialization.
-	const char* const* GetBuiltins() const;
-
 	// Tries to sent out all remaining data.
 	// FIXME: Do we still need this?
 	void Finish();

src/bro.bif

@@ -3632,7 +3632,27 @@ function piped_exec%(program: string, to_write: string%): bool
 		}
 
 	fprintf(f, "%s", to_write->CheckString());
-    pclose(f);
+	pclose(f);
 
-    return new Val(true, TYPE_BOOL);
+	return new Val(true, TYPE_BOOL);
+	%}
+
+## Enables the communication system. Note that by default,
+## communication is off until explicitly enabled, and all other calls
+## to communication-related BiFs' will be ignored until done so.
+function enable_communication%(%): any
+	%{
+	if ( bro_start_network_time != 0.0 )
+		{
+		builtin_error("communication must be enabled in bro_init");
+		return 0;
+		}
+
+	if ( using_communication )
+		// Ignore duplicate calls.
+		return 0;
+
+	using_communication = 1;
+	remote_serializer->Init();
+	return 0;
 	%}

src/main.cc

@@ -880,9 +880,6 @@ int main(int argc, char** argv)
 		exit(0);
 		}
 
-	if ( using_communication )
-		remote_serializer->Init();
-
 	persistence_serializer->SetDir((const char *)state_dir->AsString()->CheckString());
 
 	// Print the ID.