Use UDisks to find out if swap devices are encrypted

Using a heuristic is certainly not awesome.

libfwupdplugin/fu-common.c

@@ -2196,8 +2196,14 @@ fu_common_get_block_devices (GError **error)
 					  g_variant_new ("(a{sv})", &builder),
 					  G_DBUS_CALL_FLAGS_NONE,
 					  -1, NULL, error);
-	if (output == NULL)
+	if (output == NULL) {
+		if (error != NULL)
+			g_dbus_error_strip_remote_error (*error);
+		g_prefix_error (error, "failed to call %s.%s(): ",
+				UDISKS_DBUS_SERVICE,
+				"GetBlockDevices");
 		return NULL;
+	}
 	devices = g_ptr_array_new_with_free_func ((GDestroyNotify) g_object_unref);
 	g_variant_get (output, "(ao)", &iter);
 	while (g_variant_iter_next (iter, "&o", &obj)) {
@@ -2294,6 +2300,90 @@ fu_common_get_volumes_by_kind (const gchar *kind, GError **error)
 	return g_steal_pointer (&volumes);
 }
 
+/**
+ * fu_common_get_volume_by_device:
+ * @device: A device string, typcically starting with `/dev/`
+ * @error: A #GError or NULL
+ *
+ * Finds the first volume from the specified device.
+ *
+ * Returns: (transfer full): a #GPtrArray, or %NULL if the kind was not found
+ *
+ * Since: 1.5.1
+ **/
+FuVolume *
+fu_common_get_volume_by_device (const gchar *device, GError **error)
+{
+	g_autoptr(GPtrArray) devices = NULL;
+
+	/* find matching block device */
+	devices = fu_common_get_block_devices (error);
+	if (devices == NULL)
+		return NULL;
+	for (guint i = 0; i < devices->len; i++) {
+		GDBusProxy *proxy_blk = g_ptr_array_index (devices, i);
+		g_autoptr(GVariant) val = NULL;
+		val = g_dbus_proxy_get_cached_property (proxy_blk, "Device");
+		if (val == NULL)
+			continue;
+		if (g_strcmp0 (g_variant_get_bytestring (val), device) == 0) {
+			return g_object_new (FU_TYPE_VOLUME,
+					     "proxy-block", proxy_blk,
+					     NULL);
+		}
+	}
+
+	/* failed */
+	g_set_error (error,
+		     G_IO_ERROR,
+		     G_IO_ERROR_NOT_FOUND,
+		     "no volumes for device %s",
+		     device);
+	return NULL;
+}
+
+/**
+ * fu_common_get_volume_by_devnum:
+ * @devicenum: A device number
+ * @error: A #GError or NULL
+ *
+ * Finds the first volume from the specified device.
+ *
+ * Returns: (transfer full): a #GPtrArray, or %NULL if the kind was not found
+ *
+ * Since: 1.5.1
+ **/
+FuVolume *
+fu_common_get_volume_by_devnum (guint32 devnum, GError **error)
+{
+	g_autoptr(GPtrArray) devices = NULL;
+
+	/* find matching block device */
+	devices = fu_common_get_block_devices (error);
+	if (devices == NULL)
+		return NULL;
+	for (guint i = 0; i < devices->len; i++) {
+		GDBusProxy *proxy_blk = g_ptr_array_index (devices, i);
+		g_autoptr(GVariant) val = NULL;
+		val = g_dbus_proxy_get_cached_property (proxy_blk, "DeviceNumber");
+		if (val == NULL)
+			continue;
+		if (devnum == g_variant_get_uint64 (val)) {
+			return g_object_new (FU_TYPE_VOLUME,
+					     "proxy-block", proxy_blk,
+					     NULL);
+		}
+	}
+
+	/* failed */
+	g_set_error (error,
+		     G_IO_ERROR,
+		     G_IO_ERROR_NOT_FOUND,
+		     "no volumes for devnum %u",
+		     devnum);
+	return NULL;
+}
+
 /**
  * fu_common_get_esp_default:
  * @error: A #GError or NULL

libfwupdplugin/fu-common.h

@@ -238,6 +238,10 @@ gboolean	 fu_common_is_cpu_intel		(void);
 gboolean	 fu_common_is_live_media	(void);
 GPtrArray	*fu_common_get_volumes_by_kind	(const gchar	*kind,
 						 GError		**error);
+FuVolume	*fu_common_get_volume_by_device (const gchar	*device,
+						 GError		**error);
+FuVolume	*fu_common_get_volume_by_devnum	(guint32	 devnum,
+						 GError		**error);
 FuVolume	*fu_common_get_esp_for_path	(const gchar	*esp_path,
 						 GError		**error);
 FuVolume	*fu_common_get_esp_default	(GError		**error);

libfwupdplugin/fwupdplugin.map

@@ -672,6 +672,8 @@ LIBFWUPDPLUGIN_1.5.0 {
 
 LIBFWUPDPLUGIN_1.5.1 {
   global:
+    fu_common_get_volume_by_device;
+    fu_common_get_volume_by_devnum;
     fu_device_add_possible_plugin;
     fu_efivar_space_used;
     fu_volume_is_encrypted;

plugins/linux-swap/fu-linux-swap.c

@@ -13,46 +13,134 @@
 
 struct _FuLinuxSwap {
 	GObject		 parent_instance;
-	gboolean	 encrypted;
-	gboolean	 enabled;
+	guint		 encrypted_cnt;
+	guint		 enabled_cnt;
 };
 
 G_DEFINE_TYPE (FuLinuxSwap, fu_linux_swap, G_TYPE_OBJECT)
 
+static gchar *
+fu_strdup_nospaces (const gchar *line)
+{
+	GString *str = g_string_new (NULL);
+	for (guint i = 0; line[i] != '\0' && !g_ascii_isspace (line[i]); i++)
+		g_string_append_c (str, line[i]);
+	return g_string_free (str, FALSE);
+}
+
+static gboolean
+fu_linux_swap_verify_partition (FuLinuxSwap *self, const gchar *fn, GError **error)
+{
+	g_autoptr(FuVolume) volume = NULL;
+
+	/* find the device */
+	volume = fu_common_get_volume_by_device (fn, error);
+	if (volume == NULL)
+		return FALSE;
+
+	/* this isn't technically encrypted, but isn't on disk in plaintext */
+	if (g_str_has_prefix (fn, "/dev/zram")) {
+		g_debug ("%s is zram, assuming encrypted", fn);
+		self->encrypted_cnt++;
+		return TRUE;
+	}
+
+	/* is this mount point encrypted */
+	if (fu_volume_is_encrypted (volume)) {
+		g_debug ("%s partition is encrypted", fn);
+		self->encrypted_cnt++;
+	} else {
+		g_debug ("%s partition is unencrypted", fn);
+	}
+
+	/* success */
+	return TRUE;
+}
+
+static gboolean
+fu_linux_swap_verify_file (FuLinuxSwap *self, const gchar *fn, GError **error)
+{
+	guint32 devnum;
+	g_autoptr(GFile) file = NULL;
+	g_autoptr(GFileInfo) info = NULL;
+	g_autoptr(FuVolume) volume = NULL;
+
+	/* get the device number for the file */
+	file = g_file_new_for_path (fn);
+	info = g_file_query_info (file, G_FILE_ATTRIBUTE_UNIX_DEVICE,
+				  G_FILE_QUERY_INFO_NONE, NULL, error);
+	if (info == NULL)
+		return FALSE;
+	devnum = g_file_info_get_attribute_uint32 (info, G_FILE_ATTRIBUTE_UNIX_DEVICE);
+
+	/* find the device */
+	volume = fu_common_get_volume_by_devnum (devnum, error);
+	if (volume == NULL)
+		return FALSE;
+
+	/* is this mount point encrypted */
+	if (fu_volume_is_encrypted (volume)) {
+		g_debug ("%s file is encrypted", fn);
+		self->encrypted_cnt++;
+	} else {
+		g_debug ("%s file is unencrypted", fn);
+	}
+
+	/* success */
+	return TRUE;
+}
+
 FuLinuxSwap *
 fu_linux_swap_new (const gchar *buf, gsize bufsz, GError **error)
 {
 	FuLinuxSwap *self = g_object_new (FU_TYPE_LINUX_SWAP, NULL);
 	g_auto(GStrv) lines = NULL;
 
+	/* look at each line in /proc/swaps */
 	if (bufsz == 0)
 		bufsz = strlen (buf);
 	lines = fu_common_strnsplit (buf, bufsz, "\n", -1);
 	if (g_strv_length (lines) > 2) {
-		self->enabled = TRUE;
 		for (guint i = 1; lines[i] != NULL && lines[i][0] != '\0'; i++) {
-			if (g_str_has_prefix (lines[i], "/dev/dm-") ||
-			    g_str_has_prefix (lines[i], "/dev/mapper")) {
-				self->encrypted = TRUE;
-				break;
+			g_autofree gchar *fn = NULL;
+			g_autofree gchar *ty = NULL;
+
+			/* split */
+			if (g_utf8_strlen (lines[i], -1) < 45)
+				continue;
+			fn = fu_strdup_nospaces (lines[i]);
+			ty = fu_strdup_nospaces (lines[i] + 40);
+
+			/* partition, so use UDisks to see if backed by crypto */
+			if (g_strcmp0 (ty, "partition") == 0) {
+				self->enabled_cnt++;
+				if (!fu_linux_swap_verify_partition (self, fn, error))
+					return NULL;
+			} else if (g_strcmp0 (ty, "file") == 0) {
+				self->enabled_cnt++;
+				if (!fu_linux_swap_verify_file (self, fn, error))
+					return NULL;
+			} else {
+				g_warning ("unknown swap type: %s [%s]", ty, fn);
 			}
 		}
 	}
 	return self;
 }
 
+/* success if *all* the swap devices are encrypted */
 gboolean
 fu_linux_swap_get_encrypted (FuLinuxSwap *self)
 {
 	g_return_val_if_fail (FU_IS_LINUX_SWAP (self), FALSE);
-	return self->encrypted;
+	return self->enabled_cnt > 0 && self->enabled_cnt == self->encrypted_cnt;
 }
 
 gboolean
 fu_linux_swap_get_enabled (FuLinuxSwap *self)
 {
 	g_return_val_if_fail (FU_IS_LINUX_SWAP (self), FALSE);
-	return self->enabled;
+	return self->enabled_cnt > 0;
 }
 
 static void

plugins/linux-swap/fu-self-test.c

@@ -34,6 +34,14 @@ fu_linux_swap_plain_func (void)
 	swap = fu_linux_swap_new ("Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n"
 			    "/dev/nvme0n1p4                          partition\t5962748\t0\t-2\n",
 			    0, &error);
+	if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND)) {
+		g_test_skip (error->message);
+		return;
+	}
+	if (g_error_matches (error, G_DBUS_ERROR, G_DBUS_ERROR_SERVICE_UNKNOWN)) {
+		g_test_skip (error->message);
+		return;
+	}
 	g_assert_no_error (error);
 	g_assert_nonnull (swap);
 	g_assert_true (fu_linux_swap_get_enabled (swap));
@@ -49,6 +57,11 @@ fu_linux_swap_encrypted_func (void)
 	swap = fu_linux_swap_new ("Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n"
 			    "/dev/dm-1                               partition\t5962748\t0\t-2\n",
 			    0, &error);
+	if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND) ||
+	    g_error_matches (error, G_DBUS_ERROR, G_DBUS_ERROR_SERVICE_UNKNOWN)) {
+		g_test_skip (error->message);
+		return;
+	}
 	g_assert_no_error (error);
 	g_assert_nonnull (swap);
 	g_assert_true (fu_linux_swap_get_enabled (swap));