Create a filesystem abstraction layer for CSM and only allow accessing files that are scanned into it. (#5965)

* Load client-side mods into memory before executing them.

This removes the remaining filesystem access that client-sided mods had and it will hopefully make then more secure.

* Lua Virtual filesystem: don't load the files into memory just scan the filenames into memory.

* Fix the issues with backtrace

* fix most of the issues

* fix code style.

* add a comment

1 files changed, 16 insertions, 0 deletions

diff --git a/src/client.h b/src/client.h
index ab9801d62..0255b2803 100644
--- a/src/client.h
+++ b/src/client.h
@@ -37,6 +37,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapnode.h"
 #include "tileanimation.h"
 #include "mesh_generator_thread.h"
+#include <fstream>
+#include "filesys.h"
 
 #define CLIENT_CHAT_MESSAGE_LIMIT_PER_10S 10.0f
 
@@ -273,6 +275,16 @@ public:
 	~Client();
 	DISABLE_CLASS_COPY(Client);
 
+	// Load local mods into memory
+	void loadMods();
+	void scanModSubfolder(const std::string &mod_name, const std::string &mod_path,
+				std::string mod_subpath);
+	inline void scanModIntoMemory(const std::string &mod_name, const std::string &mod_path)
+	{
+		scanModSubfolder(mod_name, mod_path, "");
+	}
+
+	// Initizle the mods
 	void initMods();
 
 	/*
@@ -492,6 +504,7 @@ public:
 	bool checkLocalPrivilege(const std::string &priv)
 	{ return checkPrivilege(priv); }
 	virtual scene::IAnimatedMesh* getMesh(const std::string &filename);
+	const std::string* getModFile(const std::string &filename);
 
 	virtual std::string getModStoragePath() const;
 	virtual bool registerModStorage(ModMetadata *meta);
@@ -672,6 +685,8 @@ private:
 	// Storage for mesh data for creating multiple instances of the same mesh
 	StringMap m_mesh_data;
 
+	StringMap m_mod_files;
+
 	// own state
 	LocalClientState m_state;
 
@@ -684,6 +699,7 @@ private:
 	bool m_modding_enabled;
 	std::unordered_map<std::string, ModMetadata *> m_mod_storages;
 	float m_mod_storage_save_timer = 10.0f;
+	std::vector<ModSpec> m_mods;
 	GameUIFlags *m_game_ui_flags;
 
 	bool m_shutdown = false;