checkpoint: allow resetting the rollback timeout via D-Bus

This allows to adjust the timeout of an existing checkpoint.

The main usecase of checkpoints, is to have a fail-safe when
configuring the network remotely. By allowing to reset the timeout,
the user can perform a series of actions, and keep bumping the
timeout. That way, the entire series is still guarded by the same
checkpoint, but the user can start with short timeout, and
re-adjust the timeout as he goes along.

The libnm API only implements the async form (at least for now).
Sync methods are fundamentally wrong with D-Bus, and it's probably
not needed. Also, follow glib convenction, where the async form
doesn't have the _async name suffix. Also, accept a D-Bus path
as argument, not a NMCheckpoint instance. The libnm API should
not be more restricted than the underlying D-Bus API. It would
be cumbersome to require the user to lookup the NMCheckpoint
instance first, especially since libnm doesn't provide an efficient
or convenient lookup-by-path method. On the other hand, retrieving
the path from a NMCheckpoint instance is always possible.

1 files changed, 37 insertions, 1 deletions

diff --git a/src/nm-checkpoint.c b/src/nm-checkpoint.c
index 29e748bb39..f7e857c558 100644
--- a/src/nm-checkpoint.c
+++ b/src/nm-checkpoint.c
@@ -48,7 +48,7 @@ typedef struct {
 	NMUnmanFlagOp unmanaged_explicit;
 } DeviceCheckpoint;
 
-NM_GOBJECT_PROPERTIES_DEFINE_BASE (
+NM_GOBJECT_PROPERTIES_DEFINE (NMCheckpoint,
 	PROP_DEVICES,
 	PROP_CREATED,
 	PROP_ROLLBACK_TIMEOUT,
@@ -474,6 +474,42 @@ _timeout_cb (gpointer user_data)
 	return G_SOURCE_REMOVE;
 }
 
+void
+nm_checkpoint_adjust_rollback_timeout (NMCheckpoint *self, guint32 add_timeout)
+{
+	guint32 rollback_timeout_s;
+	gint64 now_ms, add_timeout_ms, rollback_timeout_ms;
+
+	NMCheckpointPrivate *priv = NM_CHECKPOINT_GET_PRIVATE (self);
+
+	nm_clear_g_source (&priv->timeout_id);
+
+	if (add_timeout == 0)
+		rollback_timeout_s = 0;
+	else {
+		now_ms = nm_utils_get_monotonic_timestamp_ms ();
+		add_timeout_ms = ((gint64) add_timeout) * 1000;
+		rollback_timeout_ms = (now_ms - priv->created_at_ms) + add_timeout_ms;
+
+		/* round to nearest integer second. Since NM_CHECKPOINT_ROLLBACK_TIMEOUT is
+		 * in units seconds, it will be able to exactly express the timeout. */
+		rollback_timeout_s = NM_MIN ((rollback_timeout_ms + 500) / 1000, (gint64) G_MAXUINT32);
+
+		/* we expect the timeout to be positive, because add_timeout_ms is positive.
+		 * We cannot accept a zero, because it means "infinity". */
+		nm_assert (rollback_timeout_s > 0);
+
+		priv->timeout_id = g_timeout_add (NM_MIN (add_timeout_ms, (gint64) G_MAXUINT32),
+		                                  _timeout_cb,
+		                                  self);
+	}
+
+	if (rollback_timeout_s != priv->rollback_timeout_s) {
+		priv->rollback_timeout_s = rollback_timeout_s;
+		_notify (self, PROP_ROLLBACK_TIMEOUT);
+	}
+}
+
 /*****************************************************************************/
 
 static void