checkpoint: add create, rollback and destroy D-Bus API

Co-authored-by: Thomas Haller <thaller@redhat.com>

1 files changed, 298 insertions, 0 deletions

diff --git a/src/nm-checkpoint-manager.c b/src/nm-checkpoint-manager.c
new file mode 100644
index 0000000000..254dc31e3d
--- /dev/null
+++ b/src/nm-checkpoint-manager.c
@@ -0,0 +1,298 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/* NetworkManager -- Network link manager
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Copyright (C) 2016 Red Hat, Inc.
+ */
+
+#include "nm-default.h"
+
+#include "nm-checkpoint-manager.h"
+
+#include "nm-checkpoint.h"
+#include "nm-connection.h"
+#include "nm-core-utils.h"
+#include "nm-device.h"
+#include "nm-exported-object.h"
+#include "nm-manager.h"
+#include "nm-utils.h"
+
+/*****************************************************************************/
+
+struct _NMCheckpointManager {
+	NMManager *_manager;
+	GHashTable *checkpoints;
+	guint rollback_timeout_id;
+};
+
+#define GET_MANAGER(self) \
+	({ \
+		typeof (self) _self = (self); \
+		\
+		_nm_unused NMCheckpointManager *_self2 = _self; \
+		\
+		nm_assert (_self); \
+		nm_assert (NM_IS_MANAGER (_self->_manager)); \
+		_self->_manager; \
+	})
+
+/*****************************************************************************/
+
+#define _NMLOG_PREFIX_NAME                "checkpoint"
+#define _NMLOG_DOMAIN                     LOGD_CORE
+
+#define _NMLOG(level, ...) \
+	nm_log (level, _NMLOG_DOMAIN, \
+	        "%s: " _NM_UTILS_MACRO_FIRST(__VA_ARGS__), \
+	        _NMLOG_PREFIX_NAME \
+	        _NM_UTILS_MACRO_REST(__VA_ARGS__))
+
+/*****************************************************************************/
+
+static void update_rollback_timeout (NMCheckpointManager *self);
+
+static void
+checkpoint_destroy (gpointer checkpoint)
+{
+	nm_exported_object_unexport (NM_EXPORTED_OBJECT (checkpoint));
+	g_object_unref (G_OBJECT (checkpoint));
+}
+
+static gboolean
+rollback_timeout_cb (NMCheckpointManager *self)
+{
+	NMCheckpoint *checkpoint;
+	GHashTableIter iter;
+	GVariant *result;
+	gint64 ts, now;
+
+	now = nm_utils_get_monotonic_timestamp_ms ();
+
+	g_hash_table_iter_init (&iter, self->checkpoints);
+	while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &checkpoint)) {
+		ts = nm_checkpoint_get_rollback_ts (checkpoint);
+		if (ts && ts <= now) {
+			result = nm_checkpoint_rollback (checkpoint);
+			if (result)
+				g_variant_unref (result);
+			g_hash_table_iter_remove (&iter);
+		}
+	}
+
+	self->rollback_timeout_id = 0;
+	update_rollback_timeout (self);
+
+	return G_SOURCE_REMOVE;
+}
+
+static void
+update_rollback_timeout (NMCheckpointManager *self)
+{
+	NMCheckpoint *checkpoint;
+	GHashTableIter iter;
+	gint64 ts, delta, next = G_MAXINT64;
+
+	g_hash_table_iter_init (&iter, self->checkpoints);
+	while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &checkpoint)) {
+		ts = nm_checkpoint_get_rollback_ts (checkpoint);
+		if (ts && ts < next)
+			next = ts;
+	}
+
+	nm_clear_g_source (&self->rollback_timeout_id);
+
+	if (next != G_MAXINT64) {
+		delta = MAX (next - nm_utils_get_monotonic_timestamp_ms (), 0);
+		self->rollback_timeout_id = g_timeout_add (delta,
+		                                           (GSourceFunc) rollback_timeout_cb,
+		                                           self);
+		_LOGT ("update timeout: next check in %" G_GINT64_FORMAT " ms", delta);
+	}
+}
+
+static NMCheckpoint *
+find_checkpoint_for_device (NMCheckpointManager *self, NMDevice *device)
+{
+	GHashTableIter iter;
+	NMCheckpoint *checkpoint;
+
+	g_hash_table_iter_init (&iter, self->checkpoints);
+	while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &checkpoint)) {
+		if (nm_checkpoint_includes_device (checkpoint, device))
+			return checkpoint;
+	}
+
+	return NULL;
+}
+
+NMCheckpoint *
+nm_checkpoint_manager_create (NMCheckpointManager *self,
+                              const char *const *device_paths,
+                              guint32 rollback_timeout,
+                              NMCheckpointCreateFlags flags,
+                              GError **error)
+{
+	NMCheckpoint *checkpoint;
+	const char * const *path;
+	gs_unref_ptrarray GPtrArray *devices = NULL;
+	NMDevice *device;
+	const char *checkpoint_path;
+	guint i;
+
+	g_return_val_if_fail (self, FALSE);
+	g_return_val_if_fail (!error || !*error, FALSE);
+
+	devices = g_ptr_array_new ();
+	for (path = device_paths; *path; path++) {
+		device = nm_manager_get_device_by_path (GET_MANAGER (self), *path);
+		if (!device) {
+			g_set_error (error, NM_MANAGER_ERROR, NM_MANAGER_ERROR_UNKNOWN_DEVICE,
+			             "device %s does not exist", *path);
+			return NULL;
+		}
+		g_ptr_array_add (devices, device);
+	}
+
+	if (!NM_FLAGS_HAS (flags, NM_CHECKPOINT_CREATE_FLAG_DESTROY_ALL)) {
+		for (i = 0; i < devices->len; i++) {
+			device = devices->pdata[i];
+			if (find_checkpoint_for_device (self, device)) {
+				g_set_error (error, NM_MANAGER_ERROR, NM_MANAGER_ERROR_INVALID_ARGUMENTS,
+				             "a checkpoint for device '%s' already exists",
+				             nm_device_get_iface (device));
+				return NULL;
+			}
+		}
+	}
+
+	checkpoint = nm_checkpoint_new (GET_MANAGER (self), devices,
+	                                rollback_timeout, error);
+	if (!checkpoint)
+		return NULL;
+
+	if (NM_FLAGS_HAS (flags, NM_CHECKPOINT_CREATE_FLAG_DESTROY_ALL))
+		g_hash_table_remove_all (self->checkpoints);
+
+	nm_exported_object_export (NM_EXPORTED_OBJECT (checkpoint));
+	checkpoint_path = nm_exported_object_get_path (NM_EXPORTED_OBJECT (checkpoint));
+
+	if (!nm_g_hash_table_insert (self->checkpoints,
+	                             (gpointer) checkpoint_path,
+	                             checkpoint))
+		g_return_val_if_reached (NULL);
+
+	update_rollback_timeout (self);
+
+	return checkpoint;
+}
+
+gboolean
+nm_checkpoint_manager_destroy_all (NMCheckpointManager *self,
+                                   GError **error)
+{
+	g_return_val_if_fail (self, FALSE);
+
+	g_hash_table_remove_all (self->checkpoints);
+
+	return TRUE;
+}
+
+gboolean
+nm_checkpoint_manager_destroy (NMCheckpointManager *self,
+                               const char *checkpoint_path,
+                               GError **error)
+{
+	gboolean ret;
+
+	g_return_val_if_fail (self, FALSE);
+	g_return_val_if_fail (checkpoint_path && checkpoint_path[0] == '/', FALSE);
+	g_return_val_if_fail (!error || !*error, FALSE);
+
+	if (!nm_streq (checkpoint_path, "/")) {
+		ret = g_hash_table_remove (self->checkpoints, checkpoint_path);
+		if (!ret) {
+			g_set_error (error,
+			             NM_MANAGER_ERROR,
+			             NM_MANAGER_ERROR_INVALID_ARGUMENTS,
+			             "checkpoint %s does not exist", checkpoint_path);
+		}
+		return ret;
+	} else
+		return nm_checkpoint_manager_destroy_all (self, error);
+}
+
+gboolean
+nm_checkpoint_manager_rollback (NMCheckpointManager *self,
+                                const char *checkpoint_path,
+                                GVariant **results,
+                                GError **error)
+{
+	NMCheckpoint *cp;
+
+	g_return_val_if_fail (self, FALSE);
+	g_return_val_if_fail (checkpoint_path && checkpoint_path[0] == '/', FALSE);
+	g_return_val_if_fail (results, FALSE);
+	g_return_val_if_fail (!error || !*error, FALSE);
+
+	cp = g_hash_table_lookup (self->checkpoints, checkpoint_path);
+	if (!cp) {
+		g_set_error (error, NM_MANAGER_ERROR, NM_MANAGER_ERROR_FAILED,
+		             "checkpoint %s does not exist", checkpoint_path);
+		return FALSE;
+	}
+
+	*results = nm_checkpoint_rollback (cp);
+	g_hash_table_remove (self->checkpoints, checkpoint_path);
+
+	return TRUE;
+}
+
+/*****************************************************************************/
+
+NMCheckpointManager *
+nm_checkpoint_manager_new (NMManager *manager)
+{
+	NMCheckpointManager *self;
+
+	g_return_val_if_fail (NM_IS_MANAGER (manager), FALSE);
+
+	self = g_slice_new0 (NMCheckpointManager);
+
+	/* the NMCheckpointManager instance is actually owned by NMManager.
+	 * Thus, we cannot take a reference to it, and we also don't bother
+	 * taking a weak-reference. Instead let GET_MANAGER() assert that
+	 * self->_manager is alive -- which we always expect as the lifetime
+	 * of NMManager shall surpass the lifetime of the NMCheckpointManager
+	 * instance. */
+	self->_manager = manager;
+	self->checkpoints = g_hash_table_new_full (g_str_hash, g_str_equal,
+	                                           NULL, checkpoint_destroy);
+
+	return self;
+}
+
+void
+nm_checkpoint_manager_unref (NMCheckpointManager *self)
+{
+	if (!self)
+		return;
+
+	nm_clear_g_source (&self->rollback_timeout_id);
+	g_hash_table_destroy (self->checkpoints);
+
+	g_slice_free (NMCheckpointManager, self);
+}
+