[CSM] Add flavour limits controlled by server (#5930)

* [CSM] Add flavour limits controlled by server

Server send flavour limits to client permitting to disable or limit some Lua calls

* Add limits for reading nodedefs and itemdefs

* flavour: Add lookup node limits

* Merge get_node_or_nil into get_node.

Sending fake node doesn't make sense in CSM, just return nil if node is not available for any reason

* Add node range customization when noderange flavour is enabled (default 8 nodes)

* Limit nodes range & disable chat message sending by default

* Bump protocol version

1 files changed, 14 insertions, 0 deletions

diff --git a/src/client.cpp b/src/client.cpp
index 443059c36..39bb1e2ff 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -1361,8 +1361,22 @@ void Client::removeNode(v3s16 p)
 	}
 }
 
+/**
+ * Helper function for Client Side Modding
+ * Flavour is applied there, this should not be used for core engine
+ * @param p
+ * @param is_valid_position
+ * @return
+ */
 MapNode Client::getNode(v3s16 p, bool *is_valid_position)
 {
+	if (checkCSMFlavourLimit(CSMFlavourLimit::CSM_FL_LOOKUP_NODES)) {
+		v3s16 ppos = floatToInt(m_env.getLocalPlayer()->getPosition(), BS);
+		if ((u32) ppos.getDistanceFrom(p) > m_csm_noderange_limit) {
+			*is_valid_position = false;
+			return MapNode();
+		}
+	}
 	return m_env.getMap().getNodeNoEx(p, is_valid_position);
 }