implement Lua binding

CMakeLists.txt

@@ -3,6 +3,8 @@ cmake_minimum_required(VERSION 2.6)
 PROJECT(ubus C)
 ADD_DEFINITIONS(-Os -Wall -Werror --std=gnu99 -g3)
 
+OPTION(BUILD_LUA "build Lua plugin" ON)
+
 SET(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
 
 IF(APPLE)
@@ -25,6 +27,8 @@ TARGET_LINK_LIBRARIES(ubus-example ubus ubox)
 
 SET(CMAKE_INSTALL_PREFIX /usr)
 
+ADD_SUBDIRECTORY(lua)
+
 INSTALL(TARGETS ubus cli
 	LIBRARY DESTINATION lib
 	RUNTIME DESTINATION bin

lua/CMakeLists.txt

@@ -0,0 +1,51 @@
+cmake_minimum_required(VERSION 2.6)
+
+PROJECT(ubus C)
+
+SET(CMAKE_INSTALL_PREFIX /)
+
+IF(NOT LUA_CFLAGS)
+	FIND_PROGRAM(PKG_CONFIG pkg-config)
+	IF(PKG_CONFIG)
+		EXECUTE_PROCESS(
+			COMMAND pkg-config --silence-errors --cflags lua5.1
+			OUTPUT_VARIABLE LUA_CFLAGS
+			OUTPUT_STRIP_TRAILING_WHITESPACE
+		)
+	ENDIF()
+ENDIF()
+
+ADD_DEFINITIONS(-Os -Wall -Werror --std=gnu99 -g3 -I.. ${LUA_CFLAGS})
+LINK_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR}/..)
+
+IF(APPLE)
+	SET(CMAKE_SHARED_MODULE_CREATE_C_FLAGS "${CMAKE_SHARED_MODULE_CREATE_C_FLAGS} -undefined dynamic_lookup")
+ENDIF(APPLE)
+
+IF(NOT LUAPATH)
+	EXECUTE_PROCESS(
+		COMMAND  lua -e "for k in string.gmatch(package.cpath .. \";\", \"([^;]+)/..so;\") do if k:sub(1,1) == \"/\" then print(k) break end end"
+		OUTPUT_VARIABLE LUAPATH
+		RESULT_VARIABLE LUA_CHECK_RES
+		OUTPUT_STRIP_TRAILING_WHITESPACE
+	)
+
+	IF(BUILD_LUA)
+		IF(NOT ${LUA_CHECK_RES} EQUAL 0 OR ${LUAPATH} EQUAL "")
+			MESSAGE(SEND_ERROR "Lua was not found on your system")
+		ENDIF()
+	ENDIF()
+ENDIF()
+
+IF(BUILD_LUA)
+	ADD_LIBRARY(ubus_lua MODULE ubus.c)
+	SET_TARGET_PROPERTIES(ubus_lua PROPERTIES
+		OUTPUT_NAME ubus
+		PREFIX ""
+	)
+	TARGET_LINK_LIBRARIES(ubus_lua ubus)
+
+	INSTALL(TARGETS ubus_lua
+		LIBRARY DESTINATION ${LUAPATH}
+	)
+ENDIF()

lua/ubus.c

@@ -0,0 +1,395 @@
+/*
+ * Copyright (C) 2012 Jo-Philipp Wich <jow@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * 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 <unistd.h>
+#include <libubus.h>
+#include <libubox/blobmsg.h>
+#include <lauxlib.h>
+
+
+#define MODNAME        "ubus"
+#define METANAME       MODNAME ".meta"
+
+
+struct ubus_lua_connection {
+	int timeout;
+	struct blob_buf buf;
+	struct ubus_context *ctx;
+};
+
+
+static int
+ubus_lua_parse_blob(lua_State *L, struct blob_attr *attr, bool table);
+
+static int
+ubus_lua_parse_blob_array(lua_State *L, struct blob_attr *attr, int len, bool table)
+{
+	int rv;
+	int idx = 1;
+	int rem = len;
+	struct blob_attr *pos;
+
+	lua_newtable(L);
+
+	__blob_for_each_attr(pos, attr, rem)
+	{
+		rv = ubus_lua_parse_blob(L, pos, table);
+
+		if (rv > 1)
+			lua_rawset(L, -3);
+		else if (rv > 0)
+			lua_rawseti(L, -2, idx++);
+	}
+
+	return 1;
+}
+
+static int
+ubus_lua_parse_blob(lua_State *L, struct blob_attr *attr, bool table)
+{
+	int len;
+	int off = 0;
+	void *data;
+	char buf[32];
+
+	if (!blobmsg_check_attr(attr, false))
+		return 0;
+
+	if (table && blobmsg_name(attr)[0])
+	{
+		lua_pushstring(L, blobmsg_name(attr));
+		off++;
+	}
+
+	data = blobmsg_data(attr);
+	len = blobmsg_data_len(attr);
+
+	switch (blob_id(attr))
+	{
+	case BLOBMSG_TYPE_BOOL:
+		lua_pushboolean(L, *(uint8_t *)data);
+		break;
+
+	case BLOBMSG_TYPE_INT16:
+		lua_pushinteger(L, be16_to_cpu(*(uint16_t *)data));
+		break;
+
+	case BLOBMSG_TYPE_INT32:
+		lua_pushinteger(L, be32_to_cpu(*(uint32_t *)data));
+		break;
+
+	case BLOBMSG_TYPE_INT64:
+		/* NB: Lua cannot handle 64bit, format value as string and push that */
+		sprintf(buf, "%lld", (long long int) be64_to_cpu(*(uint64_t *)data));
+		lua_pushstring(L, buf);
+		break;
+
+	case BLOBMSG_TYPE_STRING:
+		lua_pushstring(L, data);
+		break;
+
+	case BLOBMSG_TYPE_ARRAY:
+		ubus_lua_parse_blob_array(L, data, len, false);
+		break;
+
+	case BLOBMSG_TYPE_TABLE:
+		ubus_lua_parse_blob_array(L, data, len, true);
+		break;
+
+	default:
+		lua_pushnil(L);
+		break;
+	}
+
+	return off + 1;
+}
+
+
+static bool
+ubus_lua_format_blob_is_array(lua_State *L)
+{
+	lua_Integer prv = 0;
+	lua_Integer cur = 0;
+
+	/* Find out whether table is array-like */
+	for (lua_pushnil(L); lua_next(L, -2); lua_pop(L, 1))
+	{
+		if (lua_type(L, -2) != LUA_TNUMBER && lua_type(L, -2) != LUA_TINT)
+		{
+			lua_pop(L, 1);
+			return false;
+		}
+
+		cur = lua_tointeger(L, -2);
+
+		if ((cur - 1) != prv)
+		{
+			lua_pop(L, 1);
+			return false;
+		}
+
+		prv = cur;
+	}
+
+	return true;
+}
+
+static int
+ubus_lua_format_blob_array(lua_State *L, struct blob_buf *b, bool table);
+
+static int
+ubus_lua_format_blob(lua_State *L, struct blob_buf *b, bool table)
+{
+	void *c;
+	bool rv = true;
+	const char *key = table ? lua_tostring(L, -2) : NULL;
+
+	switch (lua_type(L, -1))
+	{
+	case LUA_TBOOLEAN:
+		blobmsg_add_u8(b, key, (uint8_t)lua_toboolean(L, -1));
+		break;
+
+	case LUA_TINT:
+	case LUA_TNUMBER:
+		blobmsg_add_u32(b, key, (uint32_t)lua_tointeger(L, -1));
+		break;
+
+	case LUA_TSTRING:
+	case LUA_TUSERDATA:
+	case LUA_TLIGHTUSERDATA:
+		blobmsg_add_string(b, key, lua_tostring(L, -1));
+		break;
+
+	case LUA_TTABLE:
+		if (ubus_lua_format_blob_is_array(L))
+		{
+			c = blobmsg_open_array(b, key);
+			rv = ubus_lua_format_blob_array(L, b, false);
+			blobmsg_close_array(b, c);
+		}
+		else
+		{
+			c = blobmsg_open_table(b, key);
+			rv = ubus_lua_format_blob_array(L, b, true);
+			blobmsg_close_table(b, c);
+		}
+		break;
+
+	default:
+		rv = false;
+		break;
+	}
+
+	return rv;
+}
+
+static int
+ubus_lua_format_blob_array(lua_State *L, struct blob_buf *b, bool table)
+{
+	for (lua_pushnil(L); lua_next(L, -2); lua_pop(L, 1))
+	{
+		if (!ubus_lua_format_blob(L, b, table))
+		{
+			lua_pop(L, 1);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+
+static int
+ubus_lua_connect(lua_State *L)
+{
+	struct ubus_lua_connection *c;
+	const char *sockpath = luaL_optstring(L, 1, NULL);
+	int timeout = luaL_optint(L, 2, 30);
+
+	if ((c = lua_newuserdata(L, sizeof(*c))) != NULL &&
+		(c->ctx = ubus_connect(sockpath)) != NULL)
+	{
+		c->timeout = timeout;
+		memset(&c->buf, 0, sizeof(c->buf));
+		luaL_getmetatable(L, METANAME);
+		lua_setmetatable(L, -2);
+		return 1;
+	}
+
+	/* NB: no errors from ubus_connect() yet */
+	lua_pushnil(L);
+	lua_pushinteger(L, UBUS_STATUS_UNKNOWN_ERROR);
+	return 2;
+}
+
+
+static void
+ubus_lua_objects_cb(struct ubus_context *c, struct ubus_object_data *o, void *p)
+{
+	lua_State *L = (lua_State *)p;
+
+	lua_pushstring(L, o->path);
+	lua_rawseti(L, -2, lua_objlen(L, -2) + 1);
+}
+
+static int
+ubus_lua_objects(lua_State *L)
+{
+	int rv;
+	struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
+
+	lua_newtable(L);
+	rv = ubus_lookup(c->ctx, NULL, ubus_lua_objects_cb, L);
+
+	if (rv != UBUS_STATUS_OK)
+	{
+		lua_pop(L, 1);
+		lua_pushnil(L);
+		lua_pushinteger(L, rv);
+		return 2;
+	}
+
+	return 1;
+}
+
+
+static void
+ubus_lua_signatures_cb(struct ubus_context *c, struct ubus_object_data *o, void *p)
+{
+	lua_State *L = (lua_State *)p;
+
+	if (!o->signature)
+		return;
+
+	ubus_lua_parse_blob_array(L, blob_data(o->signature), blob_len(o->signature), true);
+}
+
+static int
+ubus_lua_signatures(lua_State *L)
+{
+	int rv;
+	struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
+	const char *path = luaL_checkstring(L, 2);
+
+	rv = ubus_lookup(c->ctx, path, ubus_lua_signatures_cb, L);
+
+	if (rv != UBUS_STATUS_OK)
+	{
+		lua_pop(L, 1);
+		lua_pushnil(L);
+		lua_pushinteger(L, rv);
+		return 2;
+	}
+
+	return 1;
+}
+
+
+static void
+ubus_lua_call_cb(struct ubus_request *req, int type, struct blob_attr *msg)
+{
+	lua_State *L = (lua_State *)req->priv;
+
+	if (!msg)
+		lua_pushnil(L);
+
+	ubus_lua_parse_blob_array(L, blob_data(msg), blob_len(msg), true);
+}
+
+static int
+ubus_lua_call(lua_State *L)
+{
+	int rv;
+	uint32_t id;
+	struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
+	const char *path = luaL_checkstring(L, 2);
+	const char *func = luaL_checkstring(L, 3);
+
+	luaL_checktype(L, 4, LUA_TTABLE);
+	blob_buf_init(&c->buf, 0);
+
+	if (!ubus_lua_format_blob_array(L, &c->buf, true))
+	{
+		lua_pushnil(L);
+		lua_pushinteger(L, UBUS_STATUS_INVALID_ARGUMENT);
+		return 2;
+	}
+
+	rv = ubus_lookup_id(c->ctx, path, &id);
+
+	if (rv)
+	{
+		lua_pushnil(L);
+		lua_pushinteger(L, rv);
+		return 2;
+	}
+
+	rv = ubus_invoke(c->ctx, id, func, c->buf.head, ubus_lua_call_cb, L, c->timeout * 1000);
+
+	if (rv != UBUS_STATUS_OK)
+	{
+		lua_pop(L, 1);
+		lua_pushnil(L);
+		lua_pushinteger(L, rv);
+		return 2;
+	}
+
+	return 1;
+}
+
+
+static int
+ubus_lua__gc(lua_State *L)
+{
+	struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
+
+	if (c->ctx != NULL)
+	{
+		ubus_free(c->ctx);
+		memset(c, 0, sizeof(*c));
+	}
+
+	return 0;
+}
+
+static const luaL_Reg ubus[] = {
+	{ "connect", ubus_lua_connect },
+	{ "objects", ubus_lua_objects },
+	{ "signatures", ubus_lua_signatures },
+	{ "call", ubus_lua_call },
+	{ "close", ubus_lua__gc },
+	{ "__gc", ubus_lua__gc },
+	{ NULL, NULL },
+};
+
+
+int
+luaopen_ubus(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, ubus);
+	lua_pop(L, 1);
+
+	/* create module */
+	luaL_register(L, MODNAME, ubus);
+
+	return 0;
+}