degesch: Lua: halfplement a connector wrapper

You can't do anything reasonable with the socket now.

1 files changed, 237 insertions, 5 deletions

diff --git a/degesch.c b/degesch.c
index 5d1186c..c8aa67f 100644
--- a/degesch.c
+++ b/degesch.c
@@ -7877,7 +7877,7 @@ lua_schema_item_gc (lua_State *L)
 	return 0;
 }
 
-static luaL_Reg lua_schema_item_table[] =
+static luaL_Reg lua_schema_table[] =
 {
 	{ "__gc", lua_schema_item_gc },
 	{ NULL,   NULL               }
@@ -8117,12 +8117,242 @@ lua_plugin_setup_config (lua_State *L)
 	return 0;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+/// Identifier for the Lua metatable
+#define XLUA_CONNECTION_METATABLE "connection"
+
+struct lua_connection
+{
+	struct lua_plugin *plugin;          ///< The plugin we belong to
+	struct poller_fd socket_event;      ///< Socket is ready
+	int socket_fd;                      ///< Underlying connected socket
+};
+
+static int
+lua_connection_close (lua_State *L)
+{
+	struct lua_connection *self =
+		luaL_checkudata (L, 1, XLUA_CONNECTION_METATABLE);
+
+	if (self->socket_fd != -1)
+	{
+		poller_fd_reset (&self->socket_event);
+		xclose (self->socket_fd);
+		self->socket_fd = -1;
+	}
+
+	// Connection is dead, we don't need to hold onto any resources anymore
+	lua_cache_invalidate (L, self);
+	return 0;
+}
+
+static luaL_Reg lua_connection_table[] =
+{
+	{ "close", lua_connection_close },
+	{ "__gc",  lua_connection_close },
+	{ NULL,    NULL                 }
+};
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static void
+lua_connection_on_ready (const struct pollfd *pfd, struct lua_connection *self)
+{
+	// TODO: handle the event, invoke on_data, on_close, on_error from
+	//   our associated uservalue table as needed
+	lua_cache_invalidate (self->plugin->L, self);
+}
+
+static struct lua_connection *
+lua_plugin_push_connection (struct lua_plugin *plugin, int socket_fd)
+{
+	lua_State *L = plugin->L;
+
+	struct lua_connection *self = lua_newuserdata (L, sizeof *self);
+	luaL_setmetatable (L, XLUA_CONNECTION_METATABLE);
+	memset (self, 0, sizeof *self);
+	self->plugin = plugin;
+
+	poller_fd_init (&self->socket_event, &plugin->ctx->poller,
+		(self->socket_fd = socket_fd));
+	self->socket_event.dispatcher = (poller_fd_fn) lua_connection_on_ready;
+	self->socket_event.user_data = self;
+	poller_fd_set (&self->socket_event, POLLIN);
+
+	// Make sure the connection doesn't get garbage collected and return it
+	lua_cache_store (L, self, -1);
+	return self;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+/// Identifier for the Lua metatable
+#define XLUA_CONNECTOR_METATABLE "connector"
+
+struct lua_connector
+{
+	struct lua_plugin *plugin;          ///< The plugin we belong to
+	struct connector connector;         ///< Connector object
+	bool active;                        ///< Whether the connector is alive
+
+	int ref_on_success;                 ///< Reference to "on_success" callback
+	int ref_on_error;                   ///< Reference to "on_error" callback
+
+	char *last_error;                   ///< Connecting error, if any
+};
+
+static void
+lua_connector_discard (struct lua_connector *self)
+{
+	if (self->active)
+	{
+		connector_free (&self->connector);
+		self->active = false;
+
+		luaL_unref (self->plugin->L, LUA_REGISTRYINDEX, self->ref_on_success);
+		luaL_unref (self->plugin->L, LUA_REGISTRYINDEX, self->ref_on_error);
+		self->ref_on_success = LUA_REFNIL;
+		self->ref_on_error   = LUA_REFNIL;
+	}
+
+	free (self->last_error);
+	self->last_error = NULL;
+
+	lua_cache_invalidate (self->plugin->L, self);
+}
+
+static int
+lua_connector_abort (lua_State *L)
+{
+	struct lua_connector *self =
+		luaL_checkudata (L, 1, XLUA_CONNECTOR_METATABLE);
+	lua_connector_discard (self);
+	return 0;
+}
+
+static luaL_Reg lua_connector_table[] =
+{
+	{ "abort", lua_connector_abort },
+	{ "__gc",  lua_connector_abort },
+	{ NULL,    NULL                }
+};
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static void
+lua_connector_on_connected (void *user_data, int socket, const char *hostname)
+{
+	struct lua_connector *self = user_data;
+	struct lua_plugin *plugin = self->plugin;
+	lua_State *L = plugin->L;
+
+	// TODO: use this for SNI once TLS is implemented
+	(void) hostname;
+
+	if (self->ref_on_success != LUA_REFNIL)
+	{
+		lua_pushcfunction (L, lua_plugin_error_handler);
+
+		lua_rawgeti (L, LUA_REGISTRYINDEX, self->ref_on_success);
+		lua_plugin_push_connection (plugin, socket);  // 1: connection
+
+		if (lua_pcall (L, 1, 0, -3))
+		{
+			struct error *e = NULL;
+			(void) lua_plugin_process_error (plugin, lua_tostring (L, -1), &e);
+			lua_pop (L, 1);
+
+			log_global_error (plugin->ctx, "Lua: plugin \"#s\": #s: #s",
+				plugin->super.name, "connector on_success", e->message);
+			error_free (e);
+		}
+	}
+	lua_connector_discard (self);
+}
+
+static void
+lua_connector_on_failure (void *user_data)
+{
+	struct lua_connector *self = user_data;
+	struct lua_plugin *plugin = self->plugin;
+	lua_State *L = plugin->L;
+
+	if (self->ref_on_error != LUA_REFNIL)
+	{
+		lua_pushcfunction (L, lua_plugin_error_handler);
+
+		lua_rawgeti (L, LUA_REGISTRYINDEX, self->ref_on_error);
+		lua_pushstring (L, self->last_error);  // 1: error string
+
+		if (lua_pcall (L, 1, 0, -3))
+		{
+			struct error *e = NULL;
+			(void) lua_plugin_process_error (plugin, lua_tostring (L, -1), &e);
+			lua_pop (L, 1);
+
+			log_global_error (plugin->ctx, "Lua: plugin \"#s\": #s: #s",
+				plugin->super.name, "connector on_error", e->message);
+			error_free (e);
+		}
+	}
+	lua_connector_discard (self);
+}
+
+static void
+lua_connector_on_error (void *user_data, const char *error)
+{
+	struct lua_connector *self = user_data;
+	free (self->last_error);
+	self->last_error = xstrdup (error);
+}
+
+static int
+lua_plugin_connect (lua_State *L)
+{
+	struct lua_plugin *plugin = lua_touserdata (L, lua_upvalueindex (1));
+	const char *host = luaL_checkstring (L, 1);
+	const char *service = luaL_checkstring (L, 2);
+	luaL_checktype (L, 3, LUA_TTABLE);
+
+	struct lua_connector *self = lua_newuserdata (L, sizeof *self);
+	luaL_setmetatable (L, XLUA_CONNECTOR_METATABLE);
+	memset (self, 0, sizeof *self);
+
+	self->plugin         = plugin;
+	self->ref_on_success = LUA_REFNIL;
+	self->ref_on_error   = LUA_REFNIL;
+
+	if (lua_plugin_check_field (L, 3, "on_success", LUA_TFUNCTION, true))
+		self->ref_on_success = luaL_ref (L, -1);
+	if (lua_plugin_check_field (L, 3, "on_error",   LUA_TFUNCTION, true))
+		self->ref_on_error   = luaL_ref (L, -1);
+
+	lua_pop (L, 2);
+
+	struct app_context *ctx = plugin->ctx;
+	struct connector *connector = &self->connector;
+	connector_init (connector, &ctx->poller);
+	connector_add_target (connector, host, service);
+
+	connector->on_connected  = lua_connector_on_connected;
+	connector->on_connecting = NULL;
+	connector->on_error      = lua_connector_on_error;
+	connector->on_failure    = lua_connector_on_failure;
+	connector->user_data     = self;
+
+	self->active = true;
+	lua_cache_store (L, self, -1);
+	return 1;
+}
+
 static luaL_Reg lua_plugin_library[] =
 {
 	{ "hook_input",   lua_plugin_hook_input   },
 	{ "hook_irc",     lua_plugin_hook_irc     },
 	{ "hook_timer",   lua_plugin_hook_timer   },
 	{ "setup_config", lua_plugin_setup_config },
+	{ "connect",      lua_plugin_connect      },
 	{ NULL,           NULL                    },
 };
 
@@ -8250,10 +8480,12 @@ lua_plugin_load (struct app_context *ctx, const char *filename,
 	lua_setglobal (L, PROGRAM_NAME);
 
 	// Create metatables for our objects
-	lua_plugin_create_meta (L, XLUA_HOOK_METATABLE,   lua_hook_table);
-	lua_plugin_create_meta (L, XLUA_BUFFER_METATABLE, lua_buffer_table);
-	lua_plugin_create_meta (L, XLUA_SERVER_METATABLE, lua_server_table);
-	lua_plugin_create_meta (L, XLUA_SCHEMA_METATABLE, lua_schema_item_table);
+	lua_plugin_create_meta (L, XLUA_HOOK_METATABLE,       lua_hook_table);
+	lua_plugin_create_meta (L, XLUA_BUFFER_METATABLE,     lua_buffer_table);
+	lua_plugin_create_meta (L, XLUA_SERVER_METATABLE,     lua_server_table);
+	lua_plugin_create_meta (L, XLUA_SCHEMA_METATABLE,     lua_schema_table);
+	lua_plugin_create_meta (L, XLUA_CONNECTION_METATABLE, lua_connection_table);
+	lua_plugin_create_meta (L, XLUA_CONNECTOR_METATABLE,  lua_connector_table);
 
 	int ret;
 	if (!(ret = luaL_loadfile (L, filename))