Embedded lua scripts into FTL

.gitignore

@@ -26,3 +26,6 @@ tools/macvendor.db
 # Test Leftovers
 dig.log
 ptr.log
+
+# Compiled LUA scripts
+/src/lua/scripts/*.hex

build.sh

@@ -31,6 +31,14 @@ if [[ -n "${clean}" ]]; then
     fi
 fi
 
+# Remove compiled LUA scripts if older than the plain ones
+for scriptname in src/lua/scripts/*.lua; do
+    if [ -f "${scriptname}.hex" ] && [ "${scriptname}.hex" -ot "${scriptname}" ]; then
+        echo "INFO: ${scriptname} is outdated and will be recompiled"
+        rm "${scriptname}.hex"
+    fi
+done
+
 # Configure build, pass CMake CACHE entries if present
 # Wrap multiple options in "" as first argument to ./build.sh:
 #     ./build.sh "-DA=1 -DB=2" install

src/CMakeLists.txt

@@ -250,5 +250,6 @@ add_subdirectory(api)
 add_subdirectory(database)
 add_subdirectory(dnsmasq)
 add_subdirectory(lua)
+add_subdirectory(lua/scripts)
 add_subdirectory(tre-regex)
 add_subdirectory(syscalls)

src/args.c

@@ -264,7 +264,9 @@ void parse_args(int argc, char* argv[])
 			printf("\n");
 			printf("******************************** LUA ********************************\n");
 			printf(LUA_COPYRIGHT"\n");
-			printf("\n");
+			printf("Embedded libraries: ");
+			print_embedded_scripts();
+			printf("\n\n");
 			printf("***************************** LIBNETTLE *****************************\n");
 			printf("Version: %d.%d\n", NETTLE_VERSION_MAJOR, NETTLE_VERSION_MINOR);
 			printf("GMP: %s\n", NETTLE_USE_MINI_GMP ? "Mini" : "Full");

src/lua/ftl_lua.c

@@ -16,6 +16,7 @@
 #include "../log.h"
 #include <readline/history.h>
 #include <wordexp.h>
+#include "scripts/scripts.h"
 
 int run_lua_interpreter(const int argc, char **argv, bool dnsmasq_debug)
 {
@@ -98,9 +99,53 @@ LUAMOD_API int luaopen_pihole(lua_State *L) {
 	return LUA_YIELD;
 }
 
-// Load bundled libraries and make the available globally
+static bool ftl_lua_load_embedded_script(lua_State *L, const char *name, const char *script, const size_t script_len, const bool make_global)
+{
+	// Explanation:
+	// luaL_dostring(L, script)   expands to   (luaL_loadstring(L, script) || lua_pcall(L, 0, LUA_MULTRET, 0))
+	// luaL_loadstring(L, script)   calls   luaL_loadbuffer(L, s, strlen(s), s)
+	if (luaL_loadbufferx(L, script, script_len, name, NULL) || lua_pcall(L, 0, LUA_MULTRET, 0) != 0)
+	{
+		const char *lua_err = lua_tostring(L, -1);
+		printf("LUA error while trying to import %s.lua: %s\n", name, lua_err);
+		return false;
+	}
+
+	if(make_global)
+	{
+		/* Set global[name] = luaL_dostring return */
+		lua_setglobal(L, name);
+	}
+
+	return true;
+}
+
+struct {
+	const char *name;
+	const char *content;
+	const size_t contentlen;
+	const bool global;
+} scripts[] =
+{
+	{"inspect", inspect_lua, sizeof(inspect_lua), true},
+};
+
+// Loop over bundled LUA libraries and print their names on the console
+void print_embedded_scripts(void)
+{
+	for(unsigned int i = 0; i < sizeof(scripts)/sizeof(scripts[0]); i++)
+	{
+		char prefix[2] = { 0 };
+		double formatted = 0.0;
+		format_memory_size(prefix, scripts[i].contentlen, &formatted);
+
+		printf("%s.lua (%.2f %sB) ", scripts[i].name, formatted, prefix);
+	}
+}
+
+// Loop over bundled LUA libraries and load them
 void ftl_lua_init(lua_State *L)
 {
-	if(dolibrary(L, "inspect") != LUA_OK)
-		printf("Failed to load library inspect.lua\n");
+	for(unsigned int i = 0; i < sizeof(scripts)/sizeof(scripts[0]); i++)
+		ftl_lua_load_embedded_script(L, scripts[i].name, scripts[i].content, scripts[i].contentlen, scripts[i].global);
 }

src/lua/ftl_lua.h

@@ -21,8 +21,7 @@ int run_luac(const int argc, char **argv);
 int lua_main (int argc, char **argv);
 int luac_main (int argc, char **argv);
 
-extern int dolibrary (lua_State *L, const char *name);
-
+void print_embedded_scripts(void);
 void ftl_lua_init(lua_State *L);
 
 #endif //FTL_LUA_H

src/lua/lua.c

@@ -194,9 +194,7 @@ static int dostring (lua_State *L, const char *s, const char *name) {
 ** Calls 'require(name)' and stores the result in a global variable
 ** with the given name.
 */
-/************** Pi-hole modification ***************/
-int dolibrary (lua_State *L, const char *name) {
-/***************************************************/
+static int dolibrary (lua_State *L, const char *name) {
   int status;
   lua_getglobal(L, "require");
   lua_pushstring(L, name);

src/lua/scripts/CMakeLists.txt

@@ -0,0 +1,35 @@
+# Pi-hole: A black hole for Internet advertisements
+# (c) 2022 Pi-hole, LLC (https://pi-hole.net)
+# Network-wide ad blocking via your own hardware.
+#
+# FTL Engine
+# /src/lua/scripts/CMakeList.txt
+#
+# This file is copyright under the latest version of the EUPL.
+# Please see LICENSE file for your rights under this license.
+
+set(sources
+        inspect.lua.hex
+        scripts.h
+        )
+
+# Compile files from raw/ into hex/
+find_program(RESOURCE_COMPILER xxd)
+file(GLOB_RECURSE COMPILED_RESOURCES RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}/" "./*.lua")
+foreach(INPUT_FILE ${COMPILED_RESOURCES})
+    set(IN ${CMAKE_CURRENT_SOURCE_DIR}/${INPUT_FILE})
+    set(OUTPUT_FILE ${CMAKE_CURRENT_SOURCE_DIR}/${INPUT_FILE}.hex)
+    add_custom_command(
+        OUTPUT ${INPUT_FILE}.hex
+        COMMAND ${RESOURCE_COMPILER} -i < ${IN} > ${OUTPUT_FILE}
+        COMMENT "Compiling ${INPUT_FILE} to binary"
+        VERBATIM)
+    list(APPEND COMPILED_RESOURCES ${OUTPUT_FILE})
+endforeach()
+
+# Ensure target lua_scripts is build before target lua
+add_dependencies(lua lua_scripts)
+
+add_library(lua_scripts OBJECT ${sources})
+target_compile_options(lua_scripts PRIVATE ${EXTRAWARN})
+target_include_directories(lua_scripts PRIVATE ${PROJECT_SOURCE_DIR}/src)