Make the moduledir configurable at the runtime

daemon/engine.c

@@ -21,6 +21,7 @@
 #include <unistd.h>
 #include <grp.h>
 #include <pwd.h>
+#include <sys/param.h>
 #include <zscanner/scanner.h>
 
 #include "daemon/engine.h"
@@ -43,6 +44,13 @@ KR_NORETURN int lua_error (lua_State *L);
 /* Cleanup engine state every 5 minutes */
 const size_t CLEANUP_TIMER = 5*60*1000;
 
+/* Execute byte code */
+#define l_dobytecode(L, arr, len, name) \
+	(luaL_loadbuffer((L), (arr), (len), (name)) || lua_pcall((L), 0, LUA_MULTRET, 0))
+/** Load file in a sandbox environment. */
+#define l_dosandboxfile(L, filename) \
+	(luaL_loadfile((L), (filename)) || engine_pcall((L), 0))
+
 /*
  * Global bindings.
  */
@@ -201,6 +209,63 @@ static int l_hostname(lua_State *L)
 	return 1;
 }
 
+char *engine_get_moduledir(struct engine *engine) {
+	return engine->moduledir;
+}
+
+int engine_set_moduledir(struct engine *engine, const char *moduledir) {
+	if (!engine || !moduledir) {
+		return kr_error(EINVAL);
+	}
+
+	char *new_moduledir = strdup(moduledir);
+	if (!new_moduledir) {
+		return kr_error(ENOMEM);
+	}
+	if (engine->moduledir) {
+		free(engine->moduledir);
+	}
+	engine->moduledir = new_moduledir;
+
+	/* Use module path for including Lua scripts */
+	char l_paths[MAXPATHLEN] = { 0 };
+	/* Save original package.path to package._path */
+	snprintf(l_paths, MAXPATHLEN - 1,
+		 "if package._path == nil then package._path = package.path end\n"
+		 "package.path = '%s/?.lua;%s/?/init.lua;'..package._path\n",
+		 new_moduledir,
+		 new_moduledir);
+
+	int ret = l_dobytecode(engine->L, l_paths, strlen(l_paths), "");
+	if (ret != 0) {
+		lua_pop(engine->L, 1);
+		return ret;
+	}
+	return 0;
+}
+
+/** Return hostname. */
+static int l_moduledir(lua_State *L)
+{
+	struct engine *engine = engine_luaget(L);
+	if (lua_gettop(L) == 0) {
+		lua_pushstring(L, engine_get_moduledir(engine));
+		return 1;
+	}
+	if ((lua_gettop(L) != 1) || !lua_isstring(L, 1)) {
+		lua_pushstring(L, "moduledir takes at most one parameter: (\"directory\")");
+		lua_error(L);
+	}
+
+	if (engine_set_moduledir(engine, lua_tostring(L, 1)) != 0) {
+		lua_pushstring(L, "setting moduledir failed");
+		lua_error(L);
+	}
+
+	lua_pushstring(L, engine_get_moduledir(engine));
+	return 1;
+}
+
 /** Get/set context option. */
 static int l_option(lua_State *L)
 {
@@ -532,6 +597,8 @@ static int init_state(struct engine *engine)
 	lua_setglobal(engine->L, "quit");
 	lua_pushcfunction(engine->L, l_hostname);
 	lua_setglobal(engine->L, "hostname");
+	lua_pushcfunction(engine->L, l_moduledir);
+	lua_setglobal(engine->L, "moduledir");
 	lua_pushcfunction(engine->L, l_verbose);
 	lua_setglobal(engine->L, "verbose");
 	lua_pushcfunction(engine->L, l_option);
@@ -548,8 +615,6 @@ static int init_state(struct engine *engine)
 	lua_setglobal(engine->L, "tojson");
 	lua_pushcfunction(engine->L, l_map);
 	lua_setglobal(engine->L, "map");
-	lua_pushliteral(engine->L, MODULEDIR);
-	lua_setglobal(engine->L, "moduledir");
 	lua_pushlightuserdata(engine->L, engine);
 	lua_setglobal(engine->L, "__engine");
 	return kr_ok();
@@ -685,21 +750,9 @@ int engine_ipc(struct engine *engine, const char *expr)
 	}
 }
 
-/* Execute byte code */
-#define l_dobytecode(L, arr, len, name) \
-	(luaL_loadbuffer((L), (arr), (len), (name)) || lua_pcall((L), 0, LUA_MULTRET, 0))
-/** Load file in a sandbox environment. */
-#define l_dosandboxfile(L, filename) \
-	(luaL_loadfile((L), (filename)) || engine_pcall((L), 0))
-
 static int engine_loadconf(struct engine *engine, const char *config_path)
 {
-	/* Use module path for including Lua scripts */
-	static const char l_paths[] = "package.path = '" MODULEDIR "/?.lua;'..package.path";
-	int ret = l_dobytecode(engine->L, l_paths, sizeof(l_paths) - 1, "");
-	if (ret != 0) {
-		lua_pop(engine->L, 1);
-	}
+	int ret = 0;
 	/* Init environment */
 	static const char sandbox_bytecode[] = {
 		#include "daemon/lua/sandbox.inc"
@@ -836,7 +889,7 @@ int engine_register(struct engine *engine, const char *name, const char *precede
 		return kr_error(ENOMEM);
 	}
 	module->data = engine;
-	int ret = kr_module_load(module, name, NULL);
+	int ret = kr_module_load(module, name, engine->moduledir);
 	/* Load Lua module if not a binary */
 	if (ret == kr_error(ENOENT)) {
 		ret = ffimodule_register_lua(engine, module, name);

daemon/engine.h

@@ -61,6 +61,7 @@ struct engine {
     uv_timer_t *updater;
     char *hostname;
     struct lua_State *L;
+    char *moduledir;
 };
 
 int engine_init(struct engine *engine, knot_mm_t *pool);
@@ -89,3 +90,7 @@ struct engine *engine_luaget(struct lua_State *L);
 /** Set/get the per engine hostname */
 char *engine_get_hostname(struct engine *engine);
 int engine_set_hostname(struct engine *engine, const char *hostname);
+
+/** Set/get the per engine moduledir */
+char *engine_get_moduledir(struct engine *engine);
+int engine_set_moduledir(struct engine *engine, const char *moduledir);

daemon/main.c

@@ -341,15 +341,16 @@ static void help(int argc, char *argv[])
 {
 	printf("Usage: %s [parameters] [rundir]\n", argv[0]);
 	printf("\nParameters:\n"
-	       " -a, --addr=[addr]    Server address (default: localhost@53).\n"
-	       " -t, --tls=[addr]     Server address for TLS (default: off).\n"
-	       " -S, --fd=[fd]        Listen on given fd (handed out by supervisor).\n"
-	       " -T, --tlsfd=[fd]     Listen using TLS on given fd (handed out by supervisor).\n"
-	       " -c, --config=[path]  Config file path (relative to [rundir]) (default: config).\n"
-	       " -k, --keyfile=[path] File containing trust anchors (DS or DNSKEY).\n"
-	       " -f, --forks=N        Start N forks sharing the configuration.\n"
-	       " -q, --quiet          Quiet output, no prompt in interactive mode.\n"
-	       " -v, --verbose        Run in verbose mode."
+	       " -a, --addr=[addr]      Server address (default: localhost@53).\n"
+	       " -t, --tls=[addr]       Server address for TLS (default: off).\n"
+	       " -S, --fd=[fd]          Listen on given fd (handed out by supervisor).\n"
+	       " -T, --tlsfd=[fd]       Listen using TLS on given fd (handed out by supervisor).\n"
+	       " -c, --config=[path]    Config file path (relative to [rundir]) (default: config).\n"
+	       " -k, --keyfile=[path]   File containing trust anchors (DS or DNSKEY).\n"
+	       " -m, --moduledir=[path] Override the default module path (" MODULEDIR ").\n"
+	       " -f, --forks=N          Start N forks sharing the configuration.\n"
+	       " -q, --quiet            Quiet output, no prompt in interactive mode.\n"
+	       " -v, --verbose          Run in verbose mode."
 #ifdef NOVERBOSELOG
 	           " (Recompile without -DNOVERBOSELOG to activate.)"
 #endif
@@ -433,6 +434,7 @@ int main(int argc, char **argv)
 	array_t(int) tls_fd_set;
 	array_init(tls_fd_set);
 	char *keyfile = NULL;
+	char *moduledir = MODULEDIR;
 	const char *config = NULL;
 	int control_fd = -1;
 
@@ -446,13 +448,14 @@ int main(int argc, char **argv)
 		{"config", required_argument, 0, 'c'},
 		{"keyfile",required_argument, 0, 'k'},
 		{"forks",required_argument,   0, 'f'},
+		{"moduledir", required_argument, 0, 'm'},
 		{"verbose",    no_argument,   0, 'v'},
 		{"quiet",      no_argument,   0, 'q'},
 		{"version",   no_argument,    0, 'V'},
 		{"help",      no_argument,    0, 'h'},
 		{0, 0, 0, 0}
 	};
-	while ((c = getopt_long(argc, argv, "a:t:S:T:c:f:k:vqVh", opts, &li)) != -1) {
+	while ((c = getopt_long(argc, argv, "a:t:S:T:c:f:m:k:vqVh", opts, &li)) != -1) {
 		switch (c)
 		{
 		case 'a':
@@ -482,6 +485,9 @@ int main(int argc, char **argv)
 		case 'k':
 			keyfile = optarg;
 			break;
+		case 'm':
+			moduledir = optarg;
+			break;
 		case 'v':
 			kr_verbose_set(true);
 #ifdef NOVERBOSELOG
@@ -636,6 +642,8 @@ int main(int argc, char **argv)
 		goto cleanup;
 	}
 
+	engine_set_moduledir(&engine, moduledir);
+	
 	/* Block signals. */
 	uv_loop_t *loop = uv_default_loop();
 	uv_signal_t sigint, sigterm;

lib/module.c

@@ -132,12 +132,8 @@ int kr_module_load(struct kr_module *module, const char *name, const char *path)
 
 	/* Search for module library, use current namespace if not found. */
 	if (load_library(module, name, path) != 0) {
-		/* Expand HOME env variable, as the linker may not expand it. */
-		auto_free char *local_path = kr_strcatdup(2, getenv("HOME"), "/.local/lib/kdns_modules");
-		if (load_library(module, name, local_path) != 0) {
-			if (load_library(module, name, MODULEDIR) != 0) {
-				module->lib = RTLD_DEFAULT;
-			}
+		if (load_library(module, name, MODULEDIR) != 0) {
+			module->lib = RTLD_DEFAULT;
 		}
 	}