Merge branch 'libdbus'

lib/client_impl.c

@@ -31,6 +31,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #define _GNU_SOURCE
 
+#include <dbus/dbus.h>
 #include <dlfcn.h>
 #include <errno.h>
 #include <stdio.h>
@@ -38,9 +39,11 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
-#include <systemd/sd-bus.h>
 #include <unistd.h>
 
+// For developmental purposes
+#define DO_TRACE 0
+
 // D-Bus name, path, iface
 #define DAEMON_DBUS_NAME "com.feralinteractive.GameMode"
 #define DAEMON_DBUS_PATH "/com/feralinteractive/GameMode"
@@ -50,6 +53,29 @@ POSSIBILITY OF SUCH DAMAGE.
 #define PORTAL_DBUS_PATH "/org/freedesktop/portal/desktop"
 #define PORTAL_DBUS_IFACE "org.freedesktop.portal.GameMode"
 
+// Cleanup macros
+#define _cleanup_(x) __attribute__((cleanup(x)))
+#define _cleanup_bus_ _cleanup_(hop_off_the_bus)
+#define _cleanup_msg_ _cleanup_(cleanup_msg)
+#define _cleanup_dpc_ _cleanup_(cleanup_pending_call)
+
+#ifdef NDEBUG
+#define DEBUG(...)
+#define LOG_ERROR
+#else
+#define DEBUG(...) fprintf(stderr, __VA_ARGS__)
+#define LOG_ERROR fprintf(stderr, "ERROR: %s \n", error_string)
+#endif
+
+#ifdef DO_TRACE
+#define TRACE(...) fprintf(stderr, __VA_ARGS__)
+#else
+#define TRACE(...)
+#endif
+
+// Prototypes
+static int log_error(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
+
 // Storage for error strings
 static char error_string[512] = { 0 };
 
@@ -64,68 +90,138 @@ static int in_flatpak(void)
 	return r == 0 && sb.st_size > 0;
 }
 
-// Simple requestor function for a gamemode
-static int gamemode_request(const char *function, int arg)
+static int log_error(const char *fmt, ...)
+{
+	va_list args;
+	int n;
+
+	va_start(args, fmt);
+	n = vsnprintf(error_string, sizeof(error_string), fmt, args);
+	va_end(args);
+
+	if (n < 0)
+		DEBUG("Failed to format error string");
+	else if ((size_t)n >= sizeof(error_string))
+		DEBUG("Error log overflow");
+
+	TRACE("ERROR: %s \n", error_string);
+
+	return -1;
+}
+
+static void hop_off_the_bus(DBusConnection **bus)
+{
+	if (bus == NULL)
+		return;
+
+	dbus_connection_unref(*bus);
+}
+
+static DBusConnection *hop_on_the_bus(void)
+{
+	DBusConnection *bus;
+	DBusError err;
+
+	dbus_error_init(&err);
+
+	bus = dbus_bus_get(DBUS_BUS_SESSION, &err);
+
+	if (bus == NULL) {
+		log_error("Could not connect to bus: %s", err.message);
+		dbus_error_free(&err);
+	}
+
+	return bus;
+}
+
+/* cleanup functions */
+static void cleanup_msg(DBusMessage **msg)
 {
-	sd_bus_message *msg = NULL;
-	sd_bus *bus = NULL;
-	sd_bus_error err;
-	memset(&err, 0, sizeof(err));
-
-	int result = -1;
-
-	// Open the user bus
-	int ret = sd_bus_open_user(&bus);
-	if (ret < 0) {
-		snprintf(error_string,
-		         sizeof(error_string),
-		         "Could not connect to bus: %s",
-		         strerror(-ret));
-	} else {
-		int native = !in_flatpak();
-
-		// If we are inside a flatpak we need to talk to the portal instead
-		const char *dest = native ? DAEMON_DBUS_NAME : PORTAL_DBUS_NAME;
-		const char *path = native ? DAEMON_DBUS_PATH : PORTAL_DBUS_PATH;
-		const char *iface = native ? DAEMON_DBUS_IFACE : PORTAL_DBUS_IFACE;
-
-		// Attempt to send the requested function
-		ret = sd_bus_call_method(bus,
-		                         dest,
-		                         path,
-		                         iface,
-		                         function,
-		                         &err,
-		                         &msg,
-		                         arg ? "ii" : "i",
-		                         getpid(),
-		                         arg);
-		if (ret < 0) {
-			snprintf(error_string,
-			         sizeof(error_string),
-			         "Could not call method %s on %s\n"
-			         "\t%s\n"
-			         "\t%s\n"
-			         "\t%s\n",
-			         function,
-			         dest,
-			         err.name,
-			         err.message,
-			         strerror(-ret));
-		} else {
-			// Read the reply
-			ret = sd_bus_message_read(msg, "i", &result);
-			if (ret < 0) {
-				snprintf(error_string,
-				         sizeof(error_string),
-				         "Failure to parse response: %s",
-				         strerror(-ret));
-			}
-		}
-		sd_bus_unref(bus);
+	if (msg == NULL)
+		return;
+
+	dbus_message_unref(*msg);
+}
+
+static void cleanup_pending_call(DBusPendingCall **call)
+{
+	if (call == NULL)
+		return;
+
+	dbus_pending_call_unref(*call);
+}
+
+/* internal API */
+static int gamemode_request(const char *method, pid_t for_pid)
+{
+	_cleanup_bus_ DBusConnection *bus = NULL;
+	_cleanup_msg_ DBusMessage *msg = NULL;
+	_cleanup_dpc_ DBusPendingCall *call = NULL;
+	DBusMessageIter iter;
+	DBusError err;
+	dbus_int32_t pid;
+	int native;
+	int res = -1;
+
+	native = !in_flatpak();
+	pid = (dbus_int32_t)getpid();
+
+	TRACE("GM: [%d] request '%s' received (for pid: %d) [portal: %s]\n",
+	      (int)pid,
+	      method,
+	      (int)for_pid,
+	      (native ? "n" : "y"));
+
+	bus = hop_on_the_bus();
+
+	if (bus == NULL)
+		return -1;
+
+	// If we are inside a flatpak we need to talk to the portal instead
+	const char *dest = native ? DAEMON_DBUS_NAME : PORTAL_DBUS_NAME;
+	const char *path = native ? DAEMON_DBUS_PATH : PORTAL_DBUS_PATH;
+	const char *iface = native ? DAEMON_DBUS_IFACE : PORTAL_DBUS_IFACE;
+
+	msg = dbus_message_new_method_call(dest, path, iface, method);
+
+	if (!msg)
+		return log_error("Could not create dbus message");
+
+	dbus_message_iter_init_append(msg, &iter);
+	dbus_message_iter_append_basic(&iter, DBUS_TYPE_INT32, &pid);
+
+	if (for_pid != 0) {
+		dbus_int32_t p = (dbus_int32_t)for_pid;
+		dbus_message_iter_append_basic(&iter, DBUS_TYPE_INT32, &p);
 	}
 
-	return result;
+	dbus_connection_send_with_reply(bus, msg, &call, -1);
+	dbus_connection_flush(bus);
+	dbus_message_unref(msg);
+	msg = NULL;
+
+	dbus_pending_call_block(call);
+	msg = dbus_pending_call_steal_reply(call);
+
+	if (msg == NULL)
+		return log_error("Did not receive a reply");
+
+	dbus_error_init(&err);
+
+	if (dbus_set_error_from_message(&err, msg))
+		log_error("Could not call method '%s' on '%s': %s", method, dest, err.message);
+	else if (!dbus_message_iter_init(msg, &iter) ||
+	         dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_INT32)
+		log_error("Failed to parse response");
+	else
+		dbus_message_iter_get_basic(&iter, &res);
+
+	TRACE("GM: [%d] request '%s' done: %d\n", (int)pid, method, res);
+
+	if (dbus_error_is_set(&err))
+		dbus_error_free(&err);
+
+	return res;
 }
 
 // Get the error string

lib/meson.build

@@ -12,7 +12,7 @@ gamemode = shared_library(
         'client_impl.c',
     ],
     dependencies: [
-        dep_systemd,
+        dep_dbus,
     ],
     install: true,
     soversion: lt_current,

meson.build

@@ -79,15 +79,19 @@ path_libdir = join_paths(path_prefix, get_option('libdir'))
 path_libexecdir = join_paths(path_prefix, get_option('libexecdir'))
 
 # Find systemd via pkgconfig
+with_systemd = get_option('with-systemd')
 dep_systemd = dependency('libsystemd')
 
+# For the client, libdbus is used
+dep_dbus = dependency('dbus-1')
+
 # Allow meson to figure out how the compiler sets up threading
 dep_threads = dependency('threads')
 
 # On non glibc systems this might be a stub, i.e. for musl
 libdl = cc.find_library('dl', required: false)
 
-with_systemd = get_option('with-systemd')
+# Determine the location for the systemd unit
 if with_systemd == true
     # If the path isn't explicitly set, ask systemd for the systemd user unit directory
     path_systemd_unit_dir = get_option('with-systemd-user-unit-dir')