ircd:Ⓜ️ Add event serial size check; check size during commit.

include/ircd/m/event.h

@@ -20,6 +20,9 @@ namespace ircd::m
 
 	size_t degree(const event &);
 
+	bool check_size(std::nothrow_t, const event &);
+	void check_size(const event &);
+
 	std::string pretty(const event &);
 	std::string pretty_oneline(const event &);
 

ircd/m/event.cc

@@ -36,6 +36,44 @@ ircd::m::event_id(const event &event)
 	return at<"event_id"_>(event);
 }
 
+namespace ircd::m
+{
+	conf::item<size_t> event_max_size
+	{
+		{ "name",     "m.event.max_size" },
+		{ "default",   65507L            },
+	};
+}
+
+void
+ircd::m::check_size(const event &event)
+{
+	const size_t &event_size
+	{
+		serialized(event)
+	};
+
+	if(event_size > size_t(event_max_size))
+		throw m::BAD_JSON
+		{
+			"Event is %zu bytes which is larger than the maximum %zu bytes",
+			event_size,
+			size_t(event_max_size)
+		};
+}
+
+bool
+ircd::m::check_size(std::nothrow_t,
+                    const event &event)
+{
+	const size_t &event_size
+	{
+		serialized(event)
+	};
+
+	return event_size <= size_t(event_max_size);
+}
+
 size_t
 ircd::m::degree(const event &event)
 {

ircd/m/vm.cc

@@ -169,23 +169,7 @@ ircd::m::vm::commit(json::iov &iov)
 		iov
 	};
 
-	if(unlikely(!json::get<"event_id"_>(event)))
-	{
-		assert(0);
-		throw m::BAD_JSON
-		{
-			"Required event field: event_id"
-		};
-	}
-
-	if(unlikely(!json::get<"type"_>(event)))
-	{
-		assert(0);
-		throw m::BAD_JSON
-		{
-			"Required event field: type"
-		};
-	}
+	check_size(event);
 
 	log.debug("injecting event(mark: %ld) %s",
 	          vm::current_sequence,