// Module for interfacing with an MQTT broker #include "module.h" #include "lauxlib.h" #include "platform.h" #include "task/task.h" #include "mqtt.h" #include task_handle_t hConn; task_handle_t hOff; task_handle_t hPub; task_handle_t hSub; task_handle_t hData; //used as a holder to copy received data from the MQTT task //to the main Lua task. Due to the async nature of the tasks //we must copy the data to deliver it intact to the Lua //callback typedef struct lmqtt_ctx { mqtt_client * client; char topic[CONFIG_MQTT_MAX_LWT_TOPIC]; char * data; } lmqtt_ctx_t; // locate the C mqtt_client pointer and leave the // Lua instance on the top of the stack static mqtt_client * get_client( lua_State * L ) { if( !lua_istable( L, 1 ) ) { luaL_error( L, "Expected MQTT module (client)" ); return 0; //never reached } lua_getfield( L, 1, "_client" ); if( !lua_islightuserdata( L, -1 ) ) { luaL_error( L, "Expected MQTT client pointer" ); return 0; //never reached } mqtt_client * client = (mqtt_client *) lua_touserdata( L, -1 ); lua_pop( L, 1 ); // just pop the _mqtt field return client; } // locate the C mqtt_settings pointer and leave the // Lua instance on the top of the stack static mqtt_settings * get_settings( lua_State * L ) { if( !lua_istable( L, 1 ) ) { luaL_error( L, "Expected MQTT module (settings)" ); return 0; //never reached } lua_getfield( L, 1, "_settings" ); if( !lua_islightuserdata( L, -1 ) ) { luaL_error( L, "Expected MQTT settings pointer" ); return 0; //never reached } mqtt_settings * settings = (mqtt_settings *) lua_touserdata( L, -1 ); lua_pop( L, 1 ); // just pop the _mqtt field return settings; } // Lua: on() static int lmqtt_on(lua_State *L) { enum events{ ON_CONNECT = 0, ON_MESSAGE = 1, ON_OFFLINE = 2 }; const char *const eventnames[] = {"connect", "message", "offline", NULL}; // mqtt_settings * settings = get_settings( L ); int event = luaL_checkoption(L, 2, "message", eventnames); if( !lua_isfunction( L, 3 ) ) return 0; switch (event) { case ON_CONNECT: lua_setfield(L, 1, "_on_connect"); break; case ON_MESSAGE: lua_setfield(L, 1, "_on_message"); break; case ON_OFFLINE: lua_setfield(L, 1, "_on_offline"); break; default: return 0; } lua_pop(L, 1); //pop event name return 0; } //typedef void (*task_callback_t)(task_param_t param, task_prio_t prio); static void lmqtt_connected_cb(task_param_t param, task_prio_t prio) { lua_State * L = lua_getstate(); //returns main Lua state if( L == NULL ) return; mqtt_client * client = (mqtt_client *) param; int top = lua_gettop(L); lua_checkstack(L, 8); char key[64]; snprintf(key, 64, "mqtt_%p", client->settings); lua_getglobal( L, key ); //retrieve MQTT table from _G NODE_DBG("CB:connect: state %p, settings %p, stack top %d\n", L, client->settings, lua_gettop(L)); lua_getfield( L, -1, "_connect_ok" ); if( lua_isfunction( L, -1 ) ) { int top1 = lua_gettop(L); NODE_DBG("CB:connect: calling registered one-shot connect callback\n"); lua_pushvalue( L, -2 ); //dup mqtt table int res = lua_pcall( L, 1, 0, 0 ); //call the connect callback if( res != 0 ) NODE_DBG("CB:connect: Error when calling one-shot connect callback - (%d) %s\n", res, luaL_checkstring( L, -1 ) ); //after connecting ok, we clear _both_ the one-shot callbacks lua_pushnil(L); lua_setfield(L, 1, "_connect_ok"); lua_pushnil(L); lua_setfield(L, 1, "_connect_nok"); lua_settop(L, top1); } // now we check for the standard connect callback registered with 'mqtt:on()' lua_getfield( L, 1, "_on_connect" ); if( lua_isfunction( L, -1 ) ) { NODE_DBG("CB:connect: calling registered standard connect callback\n"); lua_pushvalue( L, 1 ); //dup mqtt table int res = lua_pcall( L, 1, 0, 0 ); //call the connect callback if( res != 0 ) NODE_DBG("CB:connect: Error when calling connect callback - (%d) %s\n", res, luaL_checkstring( L, -1 ) ); } lua_settop(L, top); } static void connected_cb( mqtt_client *client, mqtt_event_data_t *event_data ) { task_post_medium(hConn, (task_param_t) client); } static void lmqtt_disconnected_cb(task_param_t param, task_prio_t prio) { lua_State * L = lua_getstate(); //returns main Lua state if( L == NULL ) return; mqtt_client * client = (mqtt_client *) param; int top = lua_gettop(L); lua_checkstack(L, 8); char key[64]; snprintf(key, 64, "mqtt_%p", client->settings); lua_getglobal( L, key ); //retrieve MQTT table from _G NODE_DBG("CB:disconnect: state %p, settings %p, stack top %d\n", L, client->settings, lua_gettop(L)); lua_getfield( L, -1, "_connect_nok" ); if( lua_isfunction( L, -1 ) ) { NODE_DBG("CB:disconnect: calling registered one-shot disconnect callback\n"); lua_pushvalue( L, -2 ); //dup mqtt table int res = lua_pcall( L, 1, 0, 0 ); //call the disconnect callback if( res != 0 ) NODE_DBG("CB:disconnect: Error when calling one-shot disconnect callback - (%d) %s\n", res, luaL_checkstring( L, -1 ) ); //after connecting ok, we clear _both_ the one-shot callbacks lua_pushnil(L); lua_setfield(L, 1, "_connect_ok"); lua_pushnil(L); lua_setfield(L, 1, "_connect_nok"); } // now we check for the standard connect callback registered with 'mqtt:on()' lua_getfield( L, -1, "_on_offline" ); if( !lua_isfunction( L, -1 ) || lua_isnil( L, -1 ) ) return; NODE_DBG("CB:disconnect: calling registered standard offline callback\n"); lua_pushvalue( L, -2 ); //dup mqtt table int res = lua_pcall( L, 1, 0, 0 ); //call the offline callback if( res != 0 ) NODE_DBG("CB:disconnect: Error when calling offline callback - (%d) %s\n", res, luaL_checkstring( L, -1 ) ); lua_settop(L, top); } static void disconnected_cb( mqtt_client *client, mqtt_event_data_t *event_data ) { task_post_medium( hOff, (task_param_t) client); } static void lmqtt_subscribe_cb(task_param_t param, task_prio_t prio) { lua_State * L = lua_getstate(); //returns main Lua state if( L == NULL ) return; mqtt_client * client = (mqtt_client *) param; int top = lua_gettop(L); lua_checkstack(L, 8); char key[64]; snprintf(key, 64, "mqtt_%p", client->settings); lua_getglobal( L, key ); //retrieve MQTT table from _G NODE_DBG("CB:subscribe: state %p, settings %p, stack top %d\n", L, client->settings, lua_gettop(L)); lua_getfield( L, 1, "_subscribe_ok" ); if( lua_isfunction( L, -1 ) ) { NODE_DBG("CB:subscribe: calling registered one-shot subscribe callback\n"); lua_pushvalue( L, 1 ); //dup mqtt table int res = lua_pcall( L, 1, 0, 0 ); //call the disconnect callback if( res != 0 ) NODE_DBG("CB:subscribe: Error when calling one-shot subscribe callback - (%d) %s\n", res, luaL_checkstring( L, -1 ) ); lua_pushnil(L); lua_setfield(L, 1, "_subscribe_ok"); } lua_settop(L, top); } static void subscribe_cb( mqtt_client *client, mqtt_event_data_t *event_data ) { task_post_medium(hSub, (task_param_t) client); } static void lmqtt_publish_cb(task_param_t param, task_prio_t prio) { NODE_DBG("CB:publish: successfully transferred control back to main task\n"); lua_State * L = lua_getstate(); //returns main Lua state if( L == NULL ) return; mqtt_client * client = (mqtt_client *) param; int top = lua_gettop(L); lua_checkstack(L, 8); char key[64]; snprintf(key, 64, "mqtt_%p", client->settings); lua_getglobal( L, key ); //retrieve MQTT table from _G NODE_DBG("CB:publish: state %p, settings %p, stack top %d\n", L, client->settings, lua_gettop(L)); lua_getfield( L, 1, "_publish_ok" ); if( lua_isfunction( L, -1 ) ) { NODE_DBG("CB:publish: calling registered one-shot publish callback\n"); lua_pushvalue( L, 1 ); //dup mqtt table int res = lua_pcall( L, 1, 0, 0 ); //call the disconnect callback if( res != 0 ) NODE_DBG("CB:publish: Error when calling one-shot publish callback - (%d) %s\n", res, luaL_checkstring( L, -1 ) ); lua_pushnil(L); lua_setfield(L, 1, "_publish_ok"); } lua_settop(L, top); } static void publish_cb( mqtt_client *client, mqtt_event_data_t *event_data ) { NODE_DBG("CB:publish: transferring control back to main task\n"); task_post_medium(hPub, (task_param_t) client); } static void lmqtt_data_cb(task_param_t param, task_prio_t prio) { lua_State * L = lua_getstate(); //returns main Lua state if( L == NULL ) return; lmqtt_ctx_t * ctx = (lmqtt_ctx_t *) param; int top = lua_gettop(L); lua_checkstack(L, 8); char key[64]; snprintf(key, 64, "mqtt_%p", ctx->client->settings); lua_getglobal( L, key ); //retrieve MQTT table from _G NODE_DBG("CB:data: state %p, settings %p, stack top %d\n", L, ctx->client->settings, lua_gettop(L)); lua_getfield( L, 1, "_on_message" ); if( lua_isfunction( L, -1 ) ) { int numArg = 2; lua_pushvalue( L, 1 ); //dup mqtt table lua_pushstring( L, ctx->topic ); if( ctx->data != NULL ) { lua_pushstring( L, ctx->data ); numArg++; } int res = lua_pcall( L, numArg, 0, 0 ); //call the messagecallback if( res != 0 ) NODE_DBG("CB:data: Error when calling message callback - (%d) %s\n", res, luaL_checkstring( L, -1 ) ); } lua_settop(L, top); if( ctx->data != NULL ) free( ctx->data ); } static void data_cb( mqtt_client *client, mqtt_event_data_t *event_data ) { NODE_DBG("CB:data: topic len %d, data len %d\n", event_data->topic_length, event_data->data_length); lmqtt_ctx_t * ctx = malloc(sizeof(lmqtt_ctx_t)); ctx->client = client; strncpy(ctx->topic, event_data->topic, event_data->topic_length); ctx->topic[event_data->topic_length] = '\0'; ctx->data = NULL; if( event_data->data_length > 0 ) { ctx->data = malloc( event_data->data_length ); strncpy( ctx->data, event_data->data, event_data->data_length ); ctx->data[event_data->data_length] = '\0'; } task_post_medium(hData, (task_param_t) ctx); } // Lua: mqtt:connect(host[, port[, secure[, autoreconnect]]][, function(client)[, function(client, reason)]]) static int lmqtt_connect( lua_State* L ) { mqtt_settings * settings = get_settings( L ); // int secure = 0; int reconnect = 0; const char * host = luaL_checkstring( L, 2 ); int port = 1883; int n = 3; if( lua_isnumber( L, n ) ) { port = luaL_checknumber( L, n ); n++; } if( lua_isnumber( L, n ) ) { // secure = !!luaL_checkinteger( L, -4 ); n++; } if( lua_isnumber( L, n ) ) { reconnect = !!luaL_checkinteger( L, n ); n++; } if( lua_isfunction( L, n ) ) { lua_pushvalue( L, n ); lua_setfield( L, 1, "_connect_ok" ); // set _G["_cb_connect_ok"] = fn() n++; } if( lua_isfunction( L, n ) ) { lua_pushvalue( L, n ); lua_setfield(L, 1, "_connect_nok"); // set _G["_cb_connect_nok"] = fn() n++; } lua_pop( L, n - 2 ); //pop parameters strncpy(settings->host, host, CONFIG_MQTT_MAX_HOST_LEN ); settings->port = port; settings->auto_reconnect = reconnect != 0; settings->connected_cb = connected_cb; settings->disconnected_cb = disconnected_cb; settings->subscribe_cb = subscribe_cb; settings->publish_cb = publish_cb; settings->data_cb = data_cb; mqtt_client * client = mqtt_start( settings ); if( client == NULL ) { luaL_error( L, "MQTT library failed to start" ); return 0; } NODE_DBG("Created MQTT client @ %p, settings @ %p, state @ %p, top %d \n", client, settings, L, lua_gettop( L ) ); lua_pushlightuserdata( L, client ); lua_setfield( L, -2, "_client" ); //and store a reference in the MQTT table return 0; } // Lua: mqtt:close() static int lmqtt_close( lua_State* L ) { mqtt_client * client = get_client( L ); if( client == NULL ) return 0; NODE_DBG("Closing MQTT client %p\n", client); char id[64]; snprintf(id, 64, "mqtt_%p", client->settings); lua_pushnil( L ); lua_setglobal( L, id ); // remove global reference lua_pushstring( L, "_client" ); lua_pushnil( L ); lua_settable( L, -3 ); //and remove a reference in the MQTT table return 0; } // Lua: mqtt:lwt(topic, message[, qos[, retain]]) static int lmqtt_lwt( lua_State* L ) { mqtt_settings * settings = get_settings( L ); strncpy( settings->lwt_topic, luaL_checkstring( L, 2 ), CONFIG_MQTT_MAX_LWT_TOPIC ); strncpy( settings->lwt_msg, luaL_checkstring( L, 3 ), CONFIG_MQTT_MAX_LWT_MSG ); settings->lwt_msg_len = strlen( settings->lwt_msg ); int n = 4; if( lua_isnumber( L, n ) ) { settings->lwt_qos = lua_tonumber( L, n ); n++; } if( lua_isnumber( L, n ) ) { settings->lwt_retain = lua_tonumber( L, n ); n++; } lua_pop( L, n ); NODE_DBG("Set LWT topic '%s', qos %d, retain %d, len %d\n", settings->lwt_topic, settings->lwt_qos, settings->lwt_retain, settings->lwt_msg_len); return 0; } //Lua: mqtt:publish(topic, payload, qos, retain[, function(client)]) static int lmqtt_publish( lua_State * L ) { mqtt_client * client = get_client( L ); int top = lua_gettop(L); const char * topic = luaL_checkstring( L, 2 ); const char * data = luaL_checkstring( L, 3 ); int qos = luaL_checkint( L, 4 ); int retain = luaL_checkint( L, 5 ); int n = 6; if( lua_isfunction( L, n ) ) { lua_pushvalue( L, n ); lua_setfield(L, 1, "_publish_ok"); // set _G["_cb_connect_nok"] = fn() n++; } lua_settop(L, top ); NODE_DBG("MQTT publish client id %s, topic %s, %d bytes\n", client->settings->client_id, topic, strlen(data)); mqtt_publish(client, topic, data, strlen(data), qos, retain); return 0; } // Lua: mqtt:subscribe(topic, qos[, function(client)]) OR mqtt:subscribe(table[, function(client)]) static int lmqtt_subscribe( lua_State* L ) { mqtt_client * client = get_client( L ); int top = lua_gettop(L); const char * topic = luaL_checkstring( L, 2 ); int qos = luaL_checkint( L, 3 ); if( lua_isfunction( L, 4 ) ) { lua_pushvalue( L, 4 ); lua_setfield(L, 1, "_subscribe_ok"); // set _G["_cb_connect_nok"] = fn() } lua_settop(L, top ); NODE_DBG("MQTT subscribe client id %s, topic %s\n", client->settings->client_id, topic); mqtt_subscribe(client, topic, qos); return 0; } // Lua: mqtt:unsubscribe(topic[, function(client)]) OR mqtt:unsubscribe(table[, function(client)]) static int lmqtt_unsubscribe( lua_State* L ) { // mqtt_client * client = get_client( L ); return 0; } static int lmqtt_delete( lua_State* L ) { mqtt_settings * settings = get_settings( L ); if( settings != NULL ) free( settings ); mqtt_client * client = get_client( L ); if( client != NULL ) { NODE_DBG("stopping MQTT client id %s\n", client->settings->client_id); mqtt_destroy( client ); free( client ); } return 0; } // Lua: mqtt.Client(clientid, keepalive[, username, password, cleansession]) static int lmqtt_new( lua_State* L ) { const char * clientid = NULL; clientid = luaL_checkstring( L, 1 ); NODE_DBG("MQTT client id %s\n", clientid); mqtt_settings * settings = (mqtt_settings *) malloc( sizeof(mqtt_settings) ); memset(settings, 0, sizeof(mqtt_settings) ); strncpy(settings->client_id, clientid, CONFIG_MQTT_MAX_CLIENT_LEN); settings->keepalive = luaL_checkinteger( L, 2 ); int n = 2; if( lua_isstring(L, 3) ) { strncpy( settings->username, luaL_checkstring( L, 3 ), CONFIG_MQTT_MAX_USERNAME_LEN); n++; } if( lua_isstring(L, 4) ) { strncpy(settings->password, luaL_checkstring( L, 4 ), CONFIG_MQTT_MAX_PASSWORD_LEN); n++; } if( lua_isnumber(L, 5) ) { settings->clean_session = luaL_checknumber( L, 5 ); n++; } lua_pop( L, n ); //remove parameters lua_newtable( L ); NODE_DBG("New MQTT table at stack pos %d\n", lua_gettop(L)); lua_pushlightuserdata( L, settings ); lua_setfield( L, -2, "_settings" ); // set t["_mqtt"] = client lua_pushcfunction( L, lmqtt_connect ); lua_setfield( L, -2, "connect" ); // set t["connect"] = lmqtt_connect lua_pushcfunction( L, lmqtt_close ); lua_setfield( L, -2, "close" ); // set t["close"] = lmqtt_close lua_pushcfunction( L, lmqtt_lwt ); lua_setfield( L, -2, "lwt" ); // set t["lwt"] = lmqtt_lwt lua_pushcfunction( L, lmqtt_publish ); lua_setfield( L, -2, "publish" ); // set t["publish"] = lmqtt_publish lua_pushcfunction( L, lmqtt_subscribe ); lua_setfield( L, -2, "subscribe" ); // set t["subscribe"] = lmqtt_subscribe lua_pushcfunction( L, lmqtt_unsubscribe ); lua_setfield( L, -2, "unsubscribe" ); // set t["unsubscribe"] = lmqtt_unsubscribe lua_pushcfunction( L, lmqtt_on ); lua_setfield( L, -2, "on" ); // set t["on"] = lmqtt_on lua_pushcfunction( L, lmqtt_delete ); lua_setfield( L, -2, "__gc" ); // set t["__gc"] = lmqtt_delete lua_pushvalue( L, 1 ); //make a copy of the table lua_setmetatable( L, -2 ); char id[32]; snprintf( id, 32, "mqtt_%p", settings ); NODE_DBG("Store MQTT table in _G stack pos %d\n", lua_gettop(L)); lua_pushvalue( L, 1 ); //make a copy of the table lua_setglobal( L, id); hConn = task_get_id(lmqtt_connected_cb); hOff = task_get_id(lmqtt_disconnected_cb); hPub = task_get_id(lmqtt_publish_cb); hSub = task_get_id(lmqtt_subscribe_cb); hData = task_get_id(lmqtt_data_cb); NODE_DBG("conn %d, off %d, pub %d, sub %d, data %d\n", hConn, hOff, hPub, hSub, hData); return 1; //leave table on top of the stack } // Module function map static const LUA_REG_TYPE mqtt_map[] = { { LSTRKEY( "Client" ), LFUNCVAL( lmqtt_new ) }, { LNILKEY, LNILVAL } }; NODEMCU_MODULE(MQTT, "mqtt", mqtt_map, NULL);