Initial commit

lib/uci/lua/Makefile

@@ -0,0 +1,44 @@
+include ../Makefile.inc
+LUA_VERSION=5.1
+PREFIX_SEARCH=/usr /usr/local /opt/local
+LUA_PLUGINDIR=$(firstword \
+	$(foreach ldir,$(subst ;, ,$(shell lua -e 'print(package.cpath)')), \
+		$(if $(findstring lib/lua/,$(ldir)),$(patsubst %/?.so,%,$(ldir))) \
+	) \
+)
+
+# find lua prefix
+LUA_PREFIX=$(firstword \
+	$(foreach prefix,$(PREFIX_SEARCH),\
+		$(if $(wildcard $(prefix)/include/lua.h),$(prefix)) \
+	) \
+)
+
+libdir=$(prefix)/libs
+luadir=$(if $(LUA_PLUGINDIR),$(LUA_PLUGINDIR),$(libdir)/lua/$(LUA_VERSION))
+luainc=$(shell pkg-config --silence-errors --cflags lua$(LUA_VERSION))
+
+CPPFLAGS=-I.. $(if $(luainc),$(luainc), -I$(LUA_PREFIX)/include)
+LIBS=-L.. -luci $(shell pkg-config --silence-errors --libs lua$(LUA_VERSION))
+
+PLUGIN_LD=$(CC)
+ifeq ($(OS),Darwin)
+  PLUGIN_LDFLAGS=-bundle -undefined dynamic_lookup
+else
+  PLUGIN_LDFLAGS=-shared -Wl,-soname,$(SHLIB_FILE)
+endif
+
+all: uci.so
+
+uci.so: uci.o
+	$(PLUGIN_LD) $(PLUGIN_LDFLAGS) -o $@ $^ $(LIBS)
+
+%.o: %.c
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(FPIC) -c -o $@ $<
+
+install:
+	mkdir -p $(DESTDIR)$(luadir)
+	$(INSTALL) -m0644 uci.so $(DESTDIR)$(luadir)/
+
+clean:
+	rm -f *.so *.o uci.so

lib/uci/lua/uci.c

@@ -0,0 +1,928 @@
+/*
+ * libuci plugin for Lua
+ * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+
+#include <lauxlib.h>
+#include <uci.h>
+
+#define MODNAME        "uci"
+#define METANAME       MODNAME ".meta"
+//#define DEBUG 1
+
+#ifdef DEBUG
+#define DPRINTF(...) fprintf(stderr, __VA_ARGS__)
+#else
+#define DPRINTF(...) do {} while (0)
+#endif
+
+static struct uci_context *global_ctx = NULL;
+
+static struct uci_context *
+find_context(lua_State *L, int *offset)
+{
+	struct uci_context **ctx;
+	if (!lua_isuserdata(L, 1)) {
+		if (!global_ctx) {
+			global_ctx = uci_alloc_context();
+			if (!global_ctx)
+				luaL_error(L, "failed to allocate UCI context");
+		}
+		if (offset)
+			*offset = 0;
+		return global_ctx;
+	}
+	if (offset)
+		*offset = 1;
+	ctx = luaL_checkudata(L, 1, METANAME);
+	if (!ctx || !*ctx)
+		luaL_error(L, "failed to get UCI context");
+
+	return *ctx;
+}
+
+static struct uci_package *
+find_package(lua_State *L, struct uci_context *ctx, const char *str, bool al)
+{
+	struct uci_package *p = NULL;
+	struct uci_element *e;
+	char *sep;
+	char *name;
+
+	sep = strchr(str, '.');
+	if (sep) {
+		name = malloc(1 + sep - str);
+		if (!name)
+			luaL_error(L, "out of memory");
+		strncpy(name, str, sep - str);
+		name[sep - str] = 0;
+	} else
+		name = (char *) str;
+
+	uci_foreach_element(&ctx->root, e) {
+		if (strcmp(e->name, name) != 0)
+			continue;
+
+		p = uci_to_package(e);
+		goto done;
+	}
+
+	if (al == true)
+		uci_load(ctx, name, &p);
+	else if (al) {
+		uci_load(ctx, name, &p);
+	}
+
+done:
+	if (name != str)
+		free(name);
+	return p;
+}
+
+static int
+lookup_args(lua_State *L, struct uci_context *ctx, int offset, struct uci_ptr *ptr, char **buf)
+{
+	char *s = NULL;
+	int n;
+
+	n = lua_gettop(L);
+	luaL_checkstring(L, 1 + offset);
+	s = strdup(lua_tostring(L, 1 + offset));
+	if (!s)
+		goto error;
+
+	memset(ptr, 0, sizeof(struct uci_ptr));
+	if (!find_package(L, ctx, s, true))
+		goto error;
+
+	switch (n - offset) {
+	case 4:
+	case 3:
+		ptr->option = luaL_checkstring(L, 3 + offset);
+		/* fall through */
+	case 2:
+		ptr->section = luaL_checkstring(L, 2 + offset);
+		ptr->package = luaL_checkstring(L, 1 + offset);
+		if (uci_lookup_ptr(ctx, ptr, NULL, false) != UCI_OK)
+			goto error;
+		break;
+	case 1:
+		if (uci_lookup_ptr(ctx, ptr, s, false) != UCI_OK)
+			goto error;
+		break;
+	default:
+		luaL_error(L, "invalid argument count");
+		goto error;
+	}
+
+	*buf = s;
+	return 0;
+
+error:
+	if (s)
+		free(s);
+	return 1;
+}
+
+static int
+uci_push_status(lua_State *L, struct uci_context *ctx, bool hasarg)
+{
+	char *str = NULL;
+
+	if (!hasarg)
+		lua_pushboolean(L, (ctx->err == UCI_OK));
+	if (ctx->err) {
+		uci_get_errorstr(ctx, &str, MODNAME);
+		if (str) {
+			lua_pushstring(L, str);
+			free(str);
+			return 2;
+		}
+	}
+	return 1;
+}
+
+static void
+uci_push_option(lua_State *L, struct uci_option *o)
+{
+	struct uci_element *e;
+	int i = 0;
+
+	switch(o->type) {
+	case UCI_TYPE_STRING:
+		lua_pushstring(L, o->v.string);
+		break;
+	case UCI_TYPE_LIST:
+		lua_newtable(L);
+		uci_foreach_element(&o->v.list, e) {
+			i++;
+			lua_pushstring(L, e->name);
+			lua_rawseti(L, -2, i);
+		}
+		break;
+	default:
+		lua_pushnil(L);
+		break;
+	}
+}
+
+static void
+uci_push_section(lua_State *L, struct uci_section *s, int index)
+{
+	struct uci_element *e;
+
+	lua_newtable(L);
+	lua_pushboolean(L, s->anonymous);
+	lua_setfield(L, -2, ".anonymous");
+	lua_pushstring(L, s->type);
+	lua_setfield(L, -2, ".type");
+	lua_pushstring(L, s->e.name);
+	lua_setfield(L, -2, ".name");
+	if (index >= 0) {
+		lua_pushinteger(L, index);
+		lua_setfield(L, -2, ".index");
+	}
+
+	uci_foreach_element(&s->options, e) {
+		struct uci_option *o = uci_to_option(e);
+		uci_push_option(L, o);
+		lua_setfield(L, -2, o->e.name);
+	}
+}
+
+static void
+uci_push_package(lua_State *L, struct uci_package *p)
+{
+	struct uci_element *e;
+	int i = 0;
+
+	lua_newtable(L);
+	uci_foreach_element(&p->sections, e) {
+		uci_push_section(L, uci_to_section(e), i);
+		lua_setfield(L, -2, e->name);
+		i++;
+	}
+}
+
+static int
+uci_lua_unload(lua_State *L)
+{
+	struct uci_context *ctx;
+	struct uci_package *p;
+	const char *s;
+	int offset = 0;
+
+	ctx = find_context(L, &offset);
+	luaL_checkstring(L, 1 + offset);
+	s = lua_tostring(L, 1 + offset);
+	p = find_package(L, ctx, s, false);
+	if (p) {
+		uci_unload(ctx, p);
+		return uci_push_status(L, ctx, false);
+	} else {
+		lua_pushboolean(L, 0);
+	}
+	return 1;
+}
+
+static int
+uci_lua_load(lua_State *L)
+{
+	struct uci_context *ctx;
+	struct uci_package *p = NULL;
+	const char *s;
+	int offset = 0;
+
+	ctx = find_context(L, &offset);
+	uci_lua_unload(L);
+	lua_pop(L, 1); /* bool ret value of unload */
+	s = lua_tostring(L, -1);
+
+	uci_load(ctx, s, &p);
+	return uci_push_status(L, ctx, false);
+}
+
+
+static int
+uci_lua_foreach(lua_State *L)
+{
+	struct uci_context *ctx;
+	struct uci_package *p;
+	struct uci_element *e;
+	const char *package, *type;
+	bool ret = false;
+	int offset = 0;
+	int i = 0;
+
+	ctx = find_context(L, &offset);
+	package = luaL_checkstring(L, 1 + offset);
+
+	if (lua_isnil(L, 2))
+		type = NULL;
+	else
+		type = luaL_checkstring(L, 2 + offset);
+
+	if (!lua_isfunction(L, 3 + offset) || !package)
+		luaL_error(L, "Invalid argument");
+
+	p = find_package(L, ctx, package, true);
+	if (!p)
+		goto done;
+
+	uci_foreach_element(&p->sections, e) {
+		struct uci_section *s = uci_to_section(e);
+
+		i++;
+
+		if (type && (strcmp(s->type, type) != 0))
+			continue;
+
+		lua_pushvalue(L, 3 + offset); /* iterator function */
+		uci_push_section(L, s, i - 1);
+		if (lua_pcall(L, 1, 1, 0) == 0) {
+			ret = true;
+			if (lua_isboolean(L, -1) && !lua_toboolean(L, -1))
+				break;
+		}
+	}
+
+done:
+	lua_pushboolean(L, ret);
+	return 1;
+}
+
+static int
+uci_lua_get_any(lua_State *L, bool all)
+{
+	struct uci_context *ctx;
+	struct uci_element *e = NULL;
+	struct uci_ptr ptr;
+	int offset = 0;
+	char *s = NULL;
+	int err = UCI_ERR_NOTFOUND;
+
+	ctx = find_context(L, &offset);
+
+	if (lookup_args(L, ctx, offset, &ptr, &s))
+		goto error;
+
+	uci_lookup_ptr(ctx, &ptr, NULL, false);
+	if (!all && !ptr.s) {
+		err = UCI_ERR_INVAL;
+		goto error;
+	}
+	if (!(ptr.flags & UCI_LOOKUP_COMPLETE)) {
+		err = UCI_ERR_NOTFOUND;
+		goto error;
+	}
+
+	err = UCI_OK;
+	e = ptr.last;
+	switch(e->type) {
+		case UCI_TYPE_PACKAGE:
+			uci_push_package(L, ptr.p);
+			break;
+		case UCI_TYPE_SECTION:
+			if (all)
+				uci_push_section(L, ptr.s, -1);
+			else
+				lua_pushstring(L, ptr.s->type);
+			break;
+		case UCI_TYPE_OPTION:
+			uci_push_option(L, ptr.o);
+			break;
+		default:
+			err = UCI_ERR_INVAL;
+			goto error;
+	}
+	if (!err)
+		return 1;
+
+error:
+	if (s)
+		free(s);
+
+	lua_pushnil(L);
+	return uci_push_status(L, ctx, true);
+}
+
+static int
+uci_lua_get(lua_State *L)
+{
+	return uci_lua_get_any(L, false);
+}
+
+static int
+uci_lua_get_all(lua_State *L)
+{
+	return uci_lua_get_any(L, true);
+}
+
+static int
+uci_lua_add(lua_State *L)
+{
+	struct uci_context *ctx;
+	struct uci_section *s = NULL;
+	struct uci_package *p;
+	const char *package;
+	const char *type;
+	const char *name = NULL;
+	int offset = 0;
+
+	ctx = find_context(L, &offset);
+	package = luaL_checkstring(L, 1 + offset);
+	type = luaL_checkstring(L, 2 + offset);
+	p = find_package(L, ctx, package, true);
+	if (!p)
+		goto fail;
+
+	if (uci_add_section(ctx, p, type, &s) || !s)
+		goto fail;
+
+	name = s->e.name;
+	lua_pushstring(L, name);
+	return 1;
+
+fail:
+	lua_pushnil(L);
+	return uci_push_status(L, ctx, true);
+}
+
+static int
+uci_lua_delete(lua_State *L)
+{
+	struct uci_context *ctx;
+	struct uci_ptr ptr;
+	int offset = 0;
+	char *s = NULL;
+	int err = UCI_ERR_NOTFOUND;
+
+	ctx = find_context(L, &offset);
+
+	if (lookup_args(L, ctx, offset, &ptr, &s))
+		goto error;
+
+	err = uci_delete(ctx, &ptr);
+
+error:
+	if (s)
+		free(s);
+	return uci_push_status(L, ctx, false);
+}
+
+static int
+uci_lua_rename(lua_State *L)
+{
+	struct uci_context *ctx;
+	struct uci_ptr ptr;
+	int err = UCI_ERR_MEM;
+	char *s = NULL;
+	int nargs, offset = 0;
+
+	ctx = find_context(L, &offset);
+	nargs = lua_gettop(L);
+	if (lookup_args(L, ctx, offset, &ptr, &s))
+		goto error;
+
+	switch(nargs - offset) {
+	case 1:
+		/* Format: uci.set("p.s.o=v") or uci.set("p.s=v") */
+		break;
+	case 4:
+		/* Format: uci.set("p", "s", "o", "v") */
+		ptr.value = luaL_checkstring(L, nargs);
+		break;
+	case 3:
+		/* Format: uci.set("p", "s", "v") */
+		ptr.value = ptr.option;
+		ptr.option = NULL;
+		break;
+	default:
+		err = UCI_ERR_INVAL;
+		goto error;
+	}
+
+	err = uci_lookup_ptr(ctx, &ptr, NULL, false);
+	if (err)
+		goto error;
+
+	if (((ptr.s == NULL) && (ptr.option != NULL)) || (ptr.value == NULL)) {
+		err = UCI_ERR_INVAL;
+		goto error;
+	}
+
+	err = uci_rename(ctx, &ptr);
+	if (err)
+		goto error;
+
+error:
+	return uci_push_status(L, ctx, false);
+}
+
+static int
+uci_lua_reorder(lua_State *L)
+{
+	struct uci_context *ctx;
+	struct uci_ptr ptr;
+	int err = UCI_ERR_MEM;
+	char *s = NULL;
+	int nargs, offset = 0;
+
+	ctx = find_context(L, &offset);
+	nargs = lua_gettop(L);
+	if (lookup_args(L, ctx, offset, &ptr, &s))
+		goto error;
+
+	switch(nargs - offset) {
+	case 1:
+		/* Format: uci.set("p.s=v") or uci.set("p.s=v") */
+		if (ptr.option) {
+			err = UCI_ERR_INVAL;
+			goto error;
+		}
+		break;
+	case 3:
+		/* Format: uci.set("p", "s", "v") */
+		ptr.value = ptr.option;
+		ptr.option = NULL;
+		break;
+	default:
+		err = UCI_ERR_INVAL;
+		goto error;
+	}
+
+	err = uci_lookup_ptr(ctx, &ptr, NULL, false);
+	if (err)
+		goto error;
+
+	if ((ptr.s == NULL) || (ptr.value == NULL)) {
+		err = UCI_ERR_INVAL;
+		goto error;
+	}
+
+	err = uci_reorder_section(ctx, ptr.s, strtoul(ptr.value, NULL, 10));
+	if (err)
+		goto error;
+
+error:
+	return uci_push_status(L, ctx, false);
+}
+
+
+static int
+uci_lua_set(lua_State *L)
+{
+	struct uci_context *ctx;
+	struct uci_ptr ptr;
+	bool istable = false;
+	int err = UCI_ERR_MEM;
+	char *s = NULL;
+	int i, nargs, offset = 0;
+
+	ctx = find_context(L, &offset);
+	nargs = lua_gettop(L);
+	if (lookup_args(L, ctx, offset, &ptr, &s))
+		goto error;
+
+	switch(nargs - offset) {
+	case 1:
+		/* Format: uci.set("p.s.o=v") or uci.set("p.s=v") */
+		break;
+	case 4:
+		/* Format: uci.set("p", "s", "o", "v") */
+		if (lua_istable(L, nargs)) {
+			if (lua_objlen(L, nargs) < 1)
+				luaL_error(L, "Cannot set an uci option to an empty table value");
+			lua_rawgeti(L, nargs, 1);
+			ptr.value = luaL_checkstring(L, -1);
+			lua_pop(L, 1);
+			istable = true;
+		} else {
+			ptr.value = luaL_checkstring(L, nargs);
+		}
+		break;
+	case 3:
+		/* Format: uci.set("p", "s", "v") */
+		ptr.value = ptr.option;
+		ptr.option = NULL;
+		break;
+	default:
+		err = UCI_ERR_INVAL;
+		goto error;
+	}
+
+	err = uci_lookup_ptr(ctx, &ptr, NULL, false);
+	if (err)
+		goto error;
+
+	if (((ptr.s == NULL) && (ptr.option != NULL)) || (ptr.value == NULL)) {
+		err = UCI_ERR_INVAL;
+		goto error;
+	}
+
+	if (istable) {
+		if (lua_objlen(L, nargs) == 1) {
+			i = 1;
+			if (ptr.o)
+				err = uci_delete(ctx, &ptr);
+		} else {
+			i = 2;
+			err = uci_set(ctx, &ptr);
+			if (err)
+				goto error;
+		}
+
+		for (; i <= lua_objlen(L, nargs); i++) {
+			lua_rawgeti(L, nargs, i);
+			ptr.value = luaL_checkstring(L, -1);
+			err = uci_add_list(ctx, &ptr);
+			lua_pop(L, 1);
+			if (err)
+				goto error;
+		}
+	} else {
+		err = uci_set(ctx, &ptr);
+		if (err)
+			goto error;
+	}
+
+
+error:
+	return uci_push_status(L, ctx, false);
+}
+
+enum pkg_cmd {
+	CMD_SAVE,
+	CMD_COMMIT,
+	CMD_REVERT
+};
+
+static int
+uci_lua_package_cmd(lua_State *L, enum pkg_cmd cmd)
+{
+	struct uci_context *ctx;
+	struct uci_element *e, *tmp;
+	struct uci_ptr ptr;
+	char *s = NULL;
+	int failed = 0;
+	int nargs, offset = 0;
+
+	ctx = find_context(L, &offset);
+	nargs = lua_gettop(L);
+	if ((cmd != CMD_REVERT) && (nargs - offset > 1))
+		goto err;
+
+	if (lookup_args(L, ctx, offset, &ptr, &s))
+		goto err;
+
+	uci_lookup_ptr(ctx, &ptr, NULL, false);
+
+	uci_foreach_element_safe(&ctx->root, tmp, e) {
+		struct uci_package *p = uci_to_package(e);
+		int ret = UCI_ERR_INVAL;
+
+		if (ptr.p && (ptr.p != p))
+			continue;
+
+		ptr.p = p;
+		switch(cmd) {
+		case CMD_COMMIT:
+			ret = uci_commit(ctx, &p, false);
+			break;
+		case CMD_SAVE:
+			ret = uci_save(ctx, p);
+			break;
+		case CMD_REVERT:
+			ret = uci_revert(ctx, &ptr);
+			break;
+		}
+
+		if (ret != 0)
+			failed = 1;
+	}
+
+err:
+	return uci_push_status(L, ctx, false);
+}
+
+static int
+uci_lua_save(lua_State *L)
+{
+	return uci_lua_package_cmd(L, CMD_SAVE);
+}
+
+static int
+uci_lua_commit(lua_State *L)
+{
+	return uci_lua_package_cmd(L, CMD_COMMIT);
+}
+
+static int
+uci_lua_revert(lua_State *L)
+{
+	return uci_lua_package_cmd(L, CMD_REVERT);
+}
+
+static void
+uci_lua_add_change(lua_State *L, struct uci_element *e)
+{
+	struct uci_history *h;
+	const char *name;
+
+	h = uci_to_history(e);
+	if (!h->section)
+		return;
+
+	lua_getfield(L, -1, h->section);
+	if (lua_isnil(L, -1)) {
+		lua_pop(L, 1);
+		lua_newtable(L);
+		lua_pushvalue(L, -1); /* copy for setfield */
+		lua_setfield(L, -3, h->section);
+	}
+
+	name = (h->e.name ? h->e.name : ".type");
+	if (h->value)
+		lua_pushstring(L, h->value);
+	else
+		lua_pushstring(L, "");
+	lua_setfield(L, -2, name);
+	lua_pop(L, 1);
+}
+
+static void
+uci_lua_changes_pkg(lua_State *L, struct uci_context *ctx, const char *package)
+{
+	struct uci_package *p = NULL;
+	struct uci_element *e;
+	bool autoload = false;
+
+	p = find_package(L, ctx, package, false);
+	if (!p) {
+		autoload = true;
+		p = find_package(L, ctx, package, true);
+		if (!p)
+			return;
+	}
+
+	if (uci_list_empty(&p->history) && uci_list_empty(&p->saved_history))
+		goto done;
+
+	lua_newtable(L);
+	uci_foreach_element(&p->saved_history, e) {
+		uci_lua_add_change(L, e);
+	}
+	uci_foreach_element(&p->history, e) {
+		uci_lua_add_change(L, e);
+	}
+	lua_setfield(L, -2, p->e.name);
+
+done:
+	if (autoload)
+		uci_unload(ctx, p);
+}
+
+static int
+uci_lua_changes(lua_State *L)
+{
+	struct uci_context *ctx;
+	const char *package = NULL;
+	char **config = NULL;
+	int nargs;
+	int i, offset = 0;
+
+	ctx = find_context(L, &offset);
+	nargs = lua_gettop(L);
+	switch(nargs - offset) {
+	case 1:
+		package = luaL_checkstring(L, 1 + offset);
+	case 0:
+		break;
+	default:
+		luaL_error(L, "invalid argument count");
+	}
+
+	lua_newtable(L);
+	if (package) {
+		uci_lua_changes_pkg(L, ctx, package);
+	} else {
+		if (uci_list_configs(ctx, &config) != 0)
+			goto done;
+
+		for(i = 0; config[i] != NULL; i++) {
+			uci_lua_changes_pkg(L, ctx, config[i]);
+		}
+	}
+
+done:
+	return 1;
+}
+
+static int
+uci_lua_get_confdir(lua_State *L)
+{
+	struct uci_context *ctx = find_context(L, NULL);
+	lua_pushstring(L, ctx->confdir);
+	return 1;
+}
+
+static int
+uci_lua_set_confdir(lua_State *L)
+{
+	struct uci_context *ctx;
+	int ret, offset = 0;
+
+	ctx = find_context(L, &offset);
+	luaL_checkstring(L, 1 + offset);
+	ret = uci_set_confdir(ctx, lua_tostring(L, -1));
+	return uci_push_status(L, ctx, false);
+}
+
+static int
+uci_lua_get_savedir(lua_State *L)
+{
+	struct uci_context *ctx = find_context(L, NULL);
+	lua_pushstring(L, ctx->savedir);
+	return 1;
+}
+
+static int
+uci_lua_add_history(lua_State *L)
+{
+	struct uci_context *ctx;
+	int ret, offset = 0;
+
+	ctx = find_context(L, &offset);
+	luaL_checkstring(L, 1 + offset);
+	ret = uci_add_history_path(ctx, lua_tostring(L, -1));
+	return uci_push_status(L, ctx, false);
+}
+
+static int
+uci_lua_load_plugins(lua_State *L)
+{
+	struct uci_context *ctx;
+	int ret, offset = 0;
+	const char *str = NULL;
+
+	ctx = find_context(L, &offset);
+	if (lua_isstring(L, -1))
+		str = lua_tostring(L, -1);
+	ret = uci_load_plugins(ctx, str);
+	return uci_push_status(L, ctx, false);
+}
+
+static int
+uci_lua_set_savedir(lua_State *L)
+{
+	struct uci_context *ctx;
+	int ret, offset = 0;
+
+	ctx = find_context(L, &offset);
+	luaL_checkstring(L, 1 + offset);
+	ret = uci_set_savedir(ctx, lua_tostring(L, -1));
+	return uci_push_status(L, ctx, false);
+}
+
+static int
+uci_lua_gc(lua_State *L)
+{
+	struct uci_context *ctx = find_context(L, NULL);
+	uci_free_context(ctx);
+	return 0;
+}
+
+static int
+uci_lua_cursor(lua_State *L)
+{
+	struct uci_context **u;
+	int argc = lua_gettop(L);
+
+	u = lua_newuserdata(L, sizeof(struct uci_context *));
+	luaL_getmetatable(L, METANAME);
+	lua_setmetatable(L, -2);
+
+	*u = uci_alloc_context();
+	if (!*u)
+		luaL_error(L, "Cannot allocate UCI context");
+	switch (argc) {
+		case 2:
+			if (lua_isstring(L, 2) &&
+				(uci_set_savedir(*u, luaL_checkstring(L, 2)) != UCI_OK))
+				luaL_error(L, "Unable to set savedir");
+			/* fall through */
+		case 1:
+			if (lua_isstring(L, 1) &&
+				(uci_set_confdir(*u, luaL_checkstring(L, 1)) != UCI_OK))
+				luaL_error(L, "Unable to set savedir");
+			break;
+		default:
+			break;
+	}
+	return 1;
+}
+
+static const luaL_Reg uci[] = {
+	{ "__gc", uci_lua_gc },
+	{ "cursor", uci_lua_cursor },
+	{ "load", uci_lua_load },
+	{ "unload", uci_lua_unload },
+	{ "get", uci_lua_get },
+	{ "get_all", uci_lua_get_all },
+	{ "add", uci_lua_add },
+	{ "set", uci_lua_set },
+	{ "rename", uci_lua_rename },
+	{ "save", uci_lua_save },
+	{ "delete", uci_lua_delete },
+	{ "commit", uci_lua_commit },
+	{ "revert", uci_lua_revert },
+	{ "reorder", uci_lua_reorder },
+	{ "changes", uci_lua_changes },
+	{ "foreach", uci_lua_foreach },
+	{ "add_history", uci_lua_add_history },
+	{ "load_plugins", uci_lua_load_plugins },
+	{ "get_confdir", uci_lua_get_confdir },
+	{ "set_confdir", uci_lua_set_confdir },
+	{ "get_savedir", uci_lua_get_savedir },
+	{ "set_savedir", uci_lua_set_savedir },
+	{ NULL, NULL },
+};
+
+
+int
+luaopen_uci(lua_State *L)
+{
+	/* create metatable */
+	luaL_newmetatable(L, METANAME);
+
+	/* metatable.__index = metatable */
+	lua_pushvalue(L, -1);
+	lua_setfield(L, -2, "__index");
+
+	/* fill metatable */
+	luaL_register(L, NULL, uci);
+	lua_pop(L, 1);
+
+	/* create module */
+	luaL_register(L, MODNAME, uci);
+
+	return 0;
+}