virtual-device-listener: Add a device socket handler class

Instead of repeating the same code in both the virtual-image and the
virtual-device drivers, implement a class to handle the socket listening
an data reading.

Co-authored-by: Marco Trevisan (Treviño) <mail@3v1n0.net>

libfprint/drivers/virtual-device-listener.c

@@ -0,0 +1,355 @@
+/*
+ * Socket utilities for "simple" device debugging
+ *
+ * Copyright (C) 2019 Benjamin Berg <bberg@redhat.com>
+ * Copyright (C) 2020 Marco Trevisan <marco.trevisan@canonical.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#define FP_COMPONENT "virtual_device_connection"
+
+#include "fpi-log.h"
+
+#include <glib/gstdio.h>
+#include <gio/gunixsocketaddress.h>
+
+#include "virtual-device-private.h"
+
+struct _FpDeviceVirtualListener
+{
+  GSocketListener                     parent_instance;
+
+  GSocketConnection                  *connection;
+  GCancellable                       *cancellable;
+  guint                               cancellable_id;
+
+  FpDeviceVirtualListenerConnectionCb ready_cb;
+  gpointer                            ready_cb_data;
+
+  gint                                socket_fd;
+  gint                                client_fd;
+};
+
+G_DEFINE_TYPE (FpDeviceVirtualListener, fp_device_virtual_listener, G_TYPE_SOCKET_LISTENER)
+
+static void start_listen (FpDeviceVirtualListener *self);
+
+FpDeviceVirtualListener *
+fp_device_virtual_listener_new (void)
+{
+  return g_object_new (fp_device_virtual_listener_get_type (), NULL);
+}
+
+static void
+fp_device_virtual_listener_dispose (GObject *object)
+{
+  FpDeviceVirtualListener *self = FP_DEVICE_VIRTUAL_LISTENER (object);
+
+  if (self->cancellable_id)
+    {
+      g_cancellable_disconnect (self->cancellable, self->cancellable_id);
+      self->cancellable_id = 0;
+    }
+
+  g_cancellable_cancel (self->cancellable);
+  g_clear_object (&self->cancellable);
+  g_clear_object (&self->connection);
+
+  self->ready_cb = NULL;
+
+  G_OBJECT_CLASS (fp_device_virtual_listener_parent_class)->dispose (object);
+}
+
+static void
+fp_device_virtual_listener_class_init (FpDeviceVirtualListenerClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = fp_device_virtual_listener_dispose;
+}
+
+static void
+fp_device_virtual_listener_init (FpDeviceVirtualListener *self)
+{
+}
+
+static void
+new_connection_cb (GObject *source_object, GAsyncResult *res, gpointer user_data)
+{
+  g_autoptr(GError) error = NULL;
+  FpDeviceVirtualListener *self = user_data;
+  GSocketConnection *connection;
+
+  connection = g_socket_listener_accept_finish (G_SOCKET_LISTENER (source_object),
+                                                res,
+                                                NULL,
+                                                &error);
+  if (!connection)
+    {
+      if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        return;
+
+      g_warning ("Error accepting a new connection: %s", error->message);
+      start_listen (self);
+      return;
+    }
+
+  /* Always allow further connections.
+   * If we get a new one, we generally just close the old connection. */
+  start_listen (self);
+  if (self->connection)
+    {
+      g_io_stream_close (G_IO_STREAM (self->connection), NULL, NULL);
+      g_clear_object (&self->connection);
+    }
+
+  self->connection = connection;
+  fp_dbg ("Got a new connection!");
+
+  self->ready_cb (self, self->ready_cb_data);
+}
+
+static void
+start_listen (FpDeviceVirtualListener *self)
+{
+  g_socket_listener_accept_async (G_SOCKET_LISTENER (self),
+                                  self->cancellable,
+                                  new_connection_cb,
+                                  self);
+}
+
+static void
+on_cancelled (GCancellable            *cancellable,
+              FpDeviceVirtualListener *self)
+{
+  fp_device_virtual_listener_connection_close (self);
+  g_socket_listener_close (G_SOCKET_LISTENER (self));
+  g_clear_object (&self->cancellable);
+  self->ready_cb = NULL;
+}
+
+gboolean
+fp_device_virtual_listener_start (FpDeviceVirtualListener            *self,
+                                  const char                         *address,
+                                  GCancellable                       *cancellable,
+                                  FpDeviceVirtualListenerConnectionCb cb,
+                                  gpointer                            user_data,
+                                  GError                            **error)
+{
+  g_autoptr(GSocketAddress) addr = NULL;
+  G_DEBUG_HERE ();
+
+  g_return_val_if_fail (FP_IS_DEVICE_VIRTUAL_LISTENER (self), FALSE);
+  g_return_val_if_fail (cb != NULL, FALSE);
+  g_return_val_if_fail (self->ready_cb == NULL, FALSE);
+
+  self->client_fd = -1;
+
+  g_socket_listener_set_backlog (G_SOCKET_LISTENER (self), 1);
+
+  /* Remove any left over socket. */
+  g_unlink (address);
+
+  addr = g_unix_socket_address_new (address);
+
+  if (!g_socket_listener_add_address (G_SOCKET_LISTENER (self),
+                                      addr,
+                                      G_SOCKET_TYPE_STREAM,
+                                      G_SOCKET_PROTOCOL_DEFAULT,
+                                      NULL,
+                                      NULL,
+                                      error))
+    {
+      g_warning ("Could not listen on unix socket: %s", (*error)->message);
+      return FALSE;
+    }
+
+  self->ready_cb = cb;
+  self->ready_cb_data = user_data;
+  self->cancellable = cancellable ? g_object_ref (cancellable) : NULL;
+
+  if (self->cancellable)
+    self->cancellable_id = g_cancellable_connect (self->cancellable,
+                                                  G_CALLBACK (on_cancelled), self, NULL);
+
+  start_listen (self);
+
+  return TRUE;
+}
+
+gboolean
+fp_device_virtual_listener_connection_close (FpDeviceVirtualListener *self)
+{
+  g_return_val_if_fail (FP_IS_DEVICE_VIRTUAL_LISTENER (self), FALSE);
+
+  if (!self->connection)
+    return FALSE;
+
+  g_io_stream_close (G_IO_STREAM (self->connection), NULL, NULL);
+  g_clear_object (&self->connection);
+
+  return TRUE;
+}
+
+static void
+on_stream_read_cb (GObject      *source_object,
+                   GAsyncResult *res,
+                   gpointer      user_data)
+{
+  g_autoptr(GError) error = NULL;
+  g_autoptr(GTask) task = user_data;
+  FpDeviceVirtualListener *self = g_task_get_source_object (task);
+  gboolean all;
+  gboolean success;
+  gsize bytes;
+
+  all = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (task), "all"));
+
+  if (all)
+    {
+      success = g_input_stream_read_all_finish (G_INPUT_STREAM (source_object), res, &bytes, &error);
+    }
+  else
+    {
+      gssize sbytes;
+
+      sbytes = g_input_stream_read_finish (G_INPUT_STREAM (source_object), res, &error);
+      bytes = sbytes;
+      success = (sbytes >= 0);
+    }
+
+  if (g_task_return_error_if_cancelled (task))
+    return;
+
+  /* If we are cancelled, just return immediately. */
+  if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CLOSED))
+    {
+      g_task_return_int (task, 0);
+      return;
+    }
+
+  /* If this error is for an old connection (that should be closed already),
+   * then just give up immediately with a CLOSED error.
+   */
+  if (self->connection &&
+      g_io_stream_get_input_stream (G_IO_STREAM (self->connection)) != G_INPUT_STREAM (source_object))
+    {
+      g_task_return_new_error (task,
+                               G_IO_ERROR,
+                               G_IO_ERROR_CLOSED,
+                               "Error on old connection, ignoring.");
+      return;
+    }
+
+  if (!success || bytes == 0)
+    {
+      /* We accept it if someone tries to read twice and just return that error. */
+      if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_PENDING))
+        {
+          if (self->connection)
+            {
+              g_io_stream_close (G_IO_STREAM (self->connection), NULL, NULL);
+              g_clear_object (&self->connection);
+            }
+        }
+
+      if (error)
+        {
+          g_task_return_error (task, g_steal_pointer (&error));
+          return;
+        }
+      else
+        {
+          // g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_INVALID_DATA, "Got empty data");
+          return;
+        }
+    }
+
+  g_task_return_int (task, bytes);
+}
+
+void
+fp_device_virtual_listener_read (FpDeviceVirtualListener *self,
+                                 gboolean                 all,
+                                 void                    *buffer,
+                                 gsize                    count,
+                                 GAsyncReadyCallback      callback,
+                                 gpointer                 user_data)
+{
+  g_autoptr(GTask) task = NULL;
+  GInputStream *stream;
+
+  g_return_if_fail (FP_IS_DEVICE_VIRTUAL_LISTENER (self));
+
+  task = g_task_new (self, self->cancellable, callback, user_data);
+  g_object_set_data (G_OBJECT (task), "all", GINT_TO_POINTER (all));
+
+  if (!self->connection || g_io_stream_is_closed (G_IO_STREAM (self->connection)))
+    {
+      g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_CONNECTION_CLOSED,
+                               "Listener not connected to any stream");
+      return;
+    }
+
+  stream = g_io_stream_get_input_stream (G_IO_STREAM (self->connection));
+  if (all)
+    {
+      g_input_stream_read_all_async (stream, buffer, count,
+                                     G_PRIORITY_DEFAULT,
+                                     self->cancellable,
+                                     on_stream_read_cb,
+                                     g_steal_pointer (&task));
+    }
+  else
+    {
+      g_input_stream_read_async (stream, buffer, count,
+                                 G_PRIORITY_DEFAULT,
+                                 self->cancellable,
+                                 on_stream_read_cb,
+                                 g_steal_pointer (&task));
+    }
+}
+
+gsize
+fp_device_virtual_listener_read_finish (FpDeviceVirtualListener *self,
+                                        GAsyncResult            *result,
+                                        GError                 **error)
+{
+  g_return_val_if_fail (g_task_is_valid (result, self), 0);
+
+  return g_task_propagate_int (G_TASK (result), error);
+}
+
+gboolean
+fp_device_virtual_listener_write_sync (FpDeviceVirtualListener *self,
+                                       const char              *buffer,
+                                       gsize                    count,
+                                       GError                 **error)
+{
+  if (!self->connection || g_io_stream_is_closed (G_IO_STREAM (self->connection)))
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_CONNECTION_CLOSED,
+                   "Listener not connected to any stream");
+      return FALSE;
+    }
+
+  return g_output_stream_write_all (g_io_stream_get_output_stream (G_IO_STREAM (self->connection)),
+                                    buffer,
+                                    count,
+                                    NULL,
+                                    self->cancellable,
+                                    error);
+}

libfprint/drivers/virtual-device-private.h

@@ -0,0 +1,93 @@
+/*
+ * Virtual driver for "simple" device debugging
+ *
+ * Copyright (C) 2019 Benjamin Berg <bberg@redhat.com>
+ * Copyright (C) 2020 Bastien Nocera <hadess@hadess.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * This is a virtual driver to debug the non-image based drivers. A small
+ * python script is provided to connect to it via a socket, allowing
+ * prints to registered programmatically.
+ * Using this, it is possible to test libfprint and fprintd.
+ */
+
+#include <gio/gio.h>
+
+#include "fpi-device.h"
+
+#define MAX_LINE_LEN 1024
+
+G_DECLARE_FINAL_TYPE (FpDeviceVirtualListener, fp_device_virtual_listener, FP, DEVICE_VIRTUAL_LISTENER, GSocketListener)
+
+typedef void (*FpDeviceVirtualListenerConnectionCb) (FpDeviceVirtualListener *listener,
+                                                     gpointer                 user_data);
+
+FpDeviceVirtualListener * fp_device_virtual_listener_new (void);
+
+gboolean fp_device_virtual_listener_start (FpDeviceVirtualListener            *listener,
+                                           const char                         *address,
+                                           GCancellable                       *cancellable,
+                                           FpDeviceVirtualListenerConnectionCb cb,
+                                           gpointer                            user_data,
+                                           GError                            **error);
+
+gboolean fp_device_virtual_listener_connection_close (FpDeviceVirtualListener *listener);
+
+void fp_device_virtual_listener_read (FpDeviceVirtualListener *listener,
+                                      gboolean                 all,
+                                      void                    *buffer,
+                                      gsize                    count,
+                                      GAsyncReadyCallback      callback,
+                                      gpointer                 user_data);
+gsize fp_device_virtual_listener_read_finish (FpDeviceVirtualListener *listener,
+                                              GAsyncResult            *result,
+                                              GError                 **error);
+
+gboolean fp_device_virtual_listener_write_sync (FpDeviceVirtualListener *self,
+                                                const char              *buffer,
+                                                gsize                    count,
+                                                GError                 **error);
+
+
+struct _FpDeviceVirtualDevice
+{
+  FpDevice                 parent;
+
+  FpDeviceVirtualListener *listener;
+  GCancellable            *cancellable;
+
+  char                     recv_buf[MAX_LINE_LEN];
+
+  GPtrArray               *pending_commands;
+
+  GHashTable              *prints_storage;
+};
+
+/* Not really final here, but we can do this to share the FpDeviceVirtualDevice
+ * contents without having to use a shared private struct instead. */
+G_DECLARE_FINAL_TYPE (FpDeviceVirtualDevice, fpi_device_virtual_device, FP, DEVICE_VIRTUAL_DEVICE, FpDevice)
+
+struct _FpDeviceVirtualDeviceStorage
+{
+  FpDeviceVirtualDevice parent;
+};
+
+G_DECLARE_FINAL_TYPE (FpDeviceVirtualDeviceStorage, fpi_device_virtual_device_storage, FP, DEVICE_VIRTUAL_DEVICE_STORAGE, FpDeviceVirtualDevice)
+
+
+char * process_cmds (FpDeviceVirtualDevice * self, gboolean scan, GError **error);

libfprint/drivers/virtual-image.c

@@ -29,36 +29,27 @@
 
 #include "fpi-log.h"
 
+#include "virtual-device-private.h"
+
 #include "../fpi-image.h"
 #include "../fpi-image-device.h"
 
-#include <glib/gstdio.h>
-#include <gio/gio.h>
-#include <gio/gunixsocketaddress.h>
-
 struct _FpDeviceVirtualImage
 {
-  FpImageDevice      parent;
+  FpImageDevice            parent;
 
-  GSocketListener   *listener;
+  FpDeviceVirtualListener *listener;
-  GSocketConnection *connection;
+  GCancellable            *cancellable;
-  GCancellable      *listen_cancellable;
-  GCancellable      *cancellable;
 
-  gint               socket_fd;
+  gboolean                 automatic_finger;
-  gint               client_fd;
+  FpImage                 *recv_img;
-
+  gint                     recv_img_hdr[2];
-  gboolean           automatic_finger;
-  FpImage           *recv_img;
-  gint               recv_img_hdr[2];
 };
 
 G_DECLARE_FINAL_TYPE (FpDeviceVirtualImage, fpi_device_virtual_image, FPI, DEVICE_VIRTUAL_IMAGE, FpImageDevice)
 G_DEFINE_TYPE (FpDeviceVirtualImage, fpi_device_virtual_image, FP_TYPE_IMAGE_DEVICE)
 
-static void start_listen (FpDeviceVirtualImage *dev);
+static void recv_image (FpDeviceVirtualImage *self);
-static void recv_image (FpDeviceVirtualImage *dev,
-                        GInputStream         *stream);
 
 static void
 recv_image_img_recv_cb (GObject      *source_object,
@@ -66,35 +57,20 @@ recv_image_img_recv_cb (GObject      *source_object,
                         gpointer      user_data)
 {
   g_autoptr(GError) error = NULL;
+  FpDeviceVirtualListener *listener = FP_DEVICE_VIRTUAL_LISTENER (source_object);
   FpDeviceVirtualImage *self;
   FpImageDevice *device;
-  gboolean success;
+  gsize bytes;
-  gsize bytes = 0;
 
-  success = g_input_stream_read_all_finish (G_INPUT_STREAM (source_object), res, &bytes, &error);
+  bytes = fp_device_virtual_listener_read_finish (listener, res, &error);
 
-  /* Can't use self if the operation was cancelled. */
+  if (!bytes || g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED) ||
-  if (!success && g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+      g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CONNECTION_CLOSED))
     return;
 
   self = FPI_DEVICE_VIRTUAL_IMAGE (user_data);
   device = FP_IMAGE_DEVICE (self);
 
-  /* Consider success if we received the right amount of data, otherwise
-   * an error must have happened. */
-  if (bytes < self->recv_img->width * self->recv_img->height)
-    {
-      if (!success)
-        g_warning ("Error receiving image data: %s", error->message);
-      else
-        g_warning ("Error receiving image data: end of stream before all data was read");
-
-      self = FPI_DEVICE_VIRTUAL_IMAGE (user_data);
-      g_io_stream_close (G_IO_STREAM (self->connection), NULL, NULL);
-      g_clear_object (&self->connection);
-      return;
-    }
-
   if (self->automatic_finger)
     fpi_image_device_report_finger_status (device, TRUE);
   fpi_image_device_image_captured (device, g_steal_pointer (&self->recv_img));
@@ -102,7 +78,7 @@ recv_image_img_recv_cb (GObject      *source_object,
     fpi_image_device_report_finger_status (device, FALSE);
 
   /* And, listen for more images from the same client. */
-  recv_image (self, G_INPUT_STREAM (source_object));
+  recv_image (self);
 }
 
 static void
@@ -112,37 +88,30 @@ recv_image_hdr_recv_cb (GObject      *source_object,
 {
   g_autoptr(GError) error = NULL;
   FpDeviceVirtualImage *self;
-  gboolean success;
+  FpDeviceVirtualListener *listener = FP_DEVICE_VIRTUAL_LISTENER (source_object);
   gsize bytes;
 
-  success = g_input_stream_read_all_finish (G_INPUT_STREAM (source_object), res, &bytes, &error);
+  bytes = fp_device_virtual_listener_read_finish (listener, res, &error);
 
-  if (!success || bytes != sizeof (self->recv_img_hdr))
+  if (error)
     {
-      if (!success)
+      if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED) ||
-        {
+          g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CONNECTION_CLOSED) ||
-          if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED) ||
+          g_error_matches (error, G_IO_ERROR, G_IO_ERROR_PENDING))
-              g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CLOSED))
+        return;
-            return;
-          g_warning ("Error receiving header for image data: %s", error->message);
-        }
-      else if (bytes != 0)
-        {
-          g_warning ("Received incomplete header before end of stream.");
-        }
 
-      self = FPI_DEVICE_VIRTUAL_IMAGE (user_data);
+      g_warning ("Error receiving header for image data: %s", error->message);
-      g_io_stream_close (G_IO_STREAM (self->connection), NULL, NULL);
-      g_clear_object (&self->connection);
       return;
     }
 
+  if (!bytes)
+    return;
+
   self = FPI_DEVICE_VIRTUAL_IMAGE (user_data);
   if (self->recv_img_hdr[0] > 5000 || self->recv_img_hdr[1] > 5000)
     {
       g_warning ("Image header suggests an unrealistically large image, disconnecting client.");
-      g_io_stream_close (G_IO_STREAM (self->connection), NULL, NULL);
+      fp_device_virtual_listener_connection_close (listener);
-      g_clear_object (&self->connection);
     }
 
   if (self->recv_img_hdr[0] < 0 || self->recv_img_hdr[1] < 0)
@@ -178,153 +147,80 @@ recv_image_hdr_recv_cb (GObject      *source_object,
 
         default:
           /* disconnect client, it didn't play fair */
-          g_io_stream_close (G_IO_STREAM (self->connection), NULL, NULL);
+          fp_device_virtual_listener_connection_close (listener);
-          g_clear_object (&self->connection);
         }
 
       /* And, listen for more images from the same client. */
-      recv_image (self, G_INPUT_STREAM (source_object));
+      recv_image (self);
       return;
     }
 
   self->recv_img = fp_image_new (self->recv_img_hdr[0], self->recv_img_hdr[1]);
   g_debug ("image data: %p", self->recv_img->data);
-  g_input_stream_read_all_async (G_INPUT_STREAM (source_object),
+  fp_device_virtual_listener_read (listener,
-                                 (guint8 *) self->recv_img->data,
+                                   TRUE,
-                                 self->recv_img->width * self->recv_img->height,
+                                   (guint8 *) self->recv_img->data,
-                                 G_PRIORITY_DEFAULT,
+                                   self->recv_img->width * self->recv_img->height,
-                                 self->cancellable,
+                                   recv_image_img_recv_cb,
-                                 recv_image_img_recv_cb,
+                                   self);
-                                 self);
 }
 
 static void
-recv_image (FpDeviceVirtualImage *self, GInputStream *stream)
+recv_image (FpDeviceVirtualImage *self)
 {
+  fp_device_virtual_listener_read (self->listener,
+                                   TRUE,
+                                   self->recv_img_hdr,
+                                   sizeof (self->recv_img_hdr),
+                                   recv_image_hdr_recv_cb,
+                                   self);
+}
+
+static void
+on_listener_connected (FpDeviceVirtualListener *listener,
+                       gpointer                 user_data)
+{
+  FpDeviceVirtualImage *self = FPI_DEVICE_VIRTUAL_IMAGE (user_data);
   FpiImageDeviceState state;
 
-  g_object_get (self, "fpi-image-device-state", &state, NULL);
+  self->automatic_finger = TRUE;
 
-  g_debug ("Starting image receive (if active), state is: %i", state);
+  g_object_get (self,
+                "fpi-image-device-state", &state,
+                NULL);
+  /* Only read if we are in AWAIT_FINGER_* or CAPTURE states */
+  if (state <= FPI_IMAGE_DEVICE_STATE_DEACTIVATING)
+    return;
 
-  /* Only register if the state is active. */
+  recv_image (self);
-  if (state >= FPI_IMAGE_DEVICE_STATE_IDLE)
-    {
-      g_input_stream_read_all_async (stream,
-                                     self->recv_img_hdr,
-                                     sizeof (self->recv_img_hdr),
-                                     G_PRIORITY_DEFAULT,
-                                     self->cancellable,
-                                     recv_image_hdr_recv_cb,
-                                     self);
-    }
-}
-
-static void
-new_connection_cb (GObject *source_object, GAsyncResult *res, gpointer user_data)
-{
-  g_autoptr(GError) error = NULL;
-  GSocketConnection *connection;
-  GInputStream *stream;
-  FpDeviceVirtualImage *dev = user_data;
-
-  connection = g_socket_listener_accept_finish (G_SOCKET_LISTENER (source_object),
-                                                res,
-                                                NULL,
-                                                &error);
-  if (!connection)
-    {
-      if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
-        return;
-
-      g_warning ("Error accepting a new connection: %s", error->message);
-      start_listen (dev);
-    }
-
-  /* Always accept further connections (but we disconnect them immediately
-   * if we already have a connection). */
-  start_listen (dev);
-
-  if (dev->connection)
-    {
-      /* We may not have noticed that the stream was closed,
-       * if the device is deactivated.
-       * Cancel any ongoing operation on the old connection. */
-      g_cancellable_cancel (dev->cancellable);
-      g_clear_object (&dev->cancellable);
-      dev->cancellable = g_cancellable_new ();
-
-      g_clear_object (&dev->connection);
-    }
-
-  if (dev->connection)
-    {
-      g_warning ("Rejecting new connection");
-      g_io_stream_close (G_IO_STREAM (connection), NULL, NULL);
-      g_object_unref (connection);
-      return;
-    }
-
-  dev->connection = connection;
-  dev->automatic_finger = TRUE;
-  stream = g_io_stream_get_input_stream (G_IO_STREAM (connection));
-
-  fp_dbg ("Got a new connection!");
-  recv_image (dev, stream);
-}
-
-static void
-start_listen (FpDeviceVirtualImage *dev)
-{
-  g_socket_listener_accept_async (dev->listener,
-                                  dev->listen_cancellable,
-                                  new_connection_cb,
-                                  dev);
 }
 
 static void
 dev_init (FpImageDevice *dev)
 {
   g_autoptr(GError) error = NULL;
-  g_autoptr(GSocketListener) listener = NULL;
+  g_autoptr(FpDeviceVirtualListener) listener = NULL;
+  g_autoptr(GCancellable) cancellable = NULL;
   FpDeviceVirtualImage *self = FPI_DEVICE_VIRTUAL_IMAGE (dev);
-  const char *env;
 
-  g_autoptr(GSocketAddress) addr = NULL;
   G_DEBUG_HERE ();
 
-  self->client_fd = -1;
+  listener = fp_device_virtual_listener_new ();
+  cancellable = g_cancellable_new ();
 
-  env = fpi_device_get_virtual_env (FP_DEVICE (self));
+  if (!fp_device_virtual_listener_start (listener,
-
+                                         fpi_device_get_virtual_env (FP_DEVICE (self)),
-  listener = g_socket_listener_new ();
+                                         cancellable,
-  g_socket_listener_set_backlog (listener, 1);
+                                         on_listener_connected,
-
+                                         self,
-  /* Remove any left over socket. */
+                                         &error))
-  g_unlink (env);
-
-  addr = g_unix_socket_address_new (env);
-
-  if (!g_socket_listener_add_address (listener,
-                                      addr,
-                                      G_SOCKET_TYPE_STREAM,
-                                      G_SOCKET_PROTOCOL_DEFAULT,
-                                      NULL,
-                                      NULL,
-                                      &error))
     {
-      g_warning ("Could not listen on unix socket: %s", error->message);
+      fpi_image_device_open_complete (dev, g_steal_pointer (&error));
-
-      fpi_image_device_open_complete (FP_IMAGE_DEVICE (dev), g_steal_pointer (&error));
-
       return;
     }
 
   self->listener = g_steal_pointer (&listener);
-  self->cancellable = g_cancellable_new ();
+  self->cancellable = g_steal_pointer (&cancellable);
-  self->listen_cancellable = g_cancellable_new ();
-
-  start_listen (self);
 
   /* Delay result to open up the possibility of testing race conditions. */
   fpi_device_add_timeout (FP_DEVICE (dev), 100, (FpTimeoutFunc) fpi_image_device_open_complete, NULL, NULL);
@@ -338,11 +234,8 @@ dev_deinit (FpImageDevice *dev)
   G_DEBUG_HERE ();
 
   g_cancellable_cancel (self->cancellable);
-  g_cancellable_cancel (self->listen_cancellable);
   g_clear_object (&self->cancellable);
-  g_clear_object (&self->listen_cancellable);
   g_clear_object (&self->listener);
-  g_clear_object (&self->connection);
 
   /* Delay result to open up the possibility of testing race conditions. */
   fpi_device_add_timeout (FP_DEVICE (dev), 100, (FpTimeoutFunc) fpi_image_device_close_complete, NULL, NULL);
@@ -353,23 +246,16 @@ dev_activate (FpImageDevice *dev)
 {
   FpDeviceVirtualImage *self = FPI_DEVICE_VIRTUAL_IMAGE (dev);
 
-  fpi_image_device_activate_complete (dev, NULL);
+  /* Start reading (again). */
+  recv_image (self);
 
-  if (self->connection)
+  fpi_image_device_activate_complete (dev, NULL);
-    recv_image (self, g_io_stream_get_input_stream (G_IO_STREAM (self->connection)));
 }
 
 static void
 dev_deactivate (FpImageDevice *dev)
 {
-  FpDeviceVirtualImage *self = FPI_DEVICE_VIRTUAL_IMAGE (dev);
+  fpi_image_device_deactivate_complete (dev, NULL);
-
-  g_cancellable_cancel (self->cancellable);
-  g_clear_object (&self->cancellable);
-  self->cancellable = g_cancellable_new ();
-
-  /* XXX: Need to wait for the operation to be cancelled. */
-  fpi_device_add_timeout (FP_DEVICE (dev), 10, (FpTimeoutFunc) fpi_image_device_deactivate_complete, NULL, NULL);
 }
 
 static void

libfprint/meson.build

@@ -155,6 +155,9 @@ foreach driver: drivers
     if driver == 'virtual_image'
         drivers_sources += [ 'drivers/virtual-image.c' ]
     endif
+    if driver.startswith('virtual_')
+        drivers_sources += [ 'drivers/virtual-device-listener.c' ]
+    endif
     if driver == 'synaptics'
     drivers_sources += [
         'drivers/synaptics/synaptics.c',