clipboard: file transfer portal support

Implement file-list <-> application/vnd.flatpak.file-list
serialization by talking to the file transfer portal.

See https://github.com/flatpak/xdg-desktop-portal/pull/222

1 files changed, 341 insertions, 0 deletions

diff --git a/gdk/filetransferportal.c b/gdk/filetransferportal.c
new file mode 100644
index 0000000000..97e4134651
--- /dev/null
+++ b/gdk/filetransferportal.c
@@ -0,0 +1,341 @@
+/*
+ * Copyright (C) 2018 Matthias Clasen
+ *
+ * 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 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include <gio/gio.h>
+#include <gio/gunixfdlist.h>
+
+#include "filetransferportalprivate.h"
+
+static GDBusProxy *file_transfer_proxy = NULL;
+
+static GDBusProxy *
+ensure_file_transfer_portal (void)
+{
+  if (file_transfer_proxy == NULL)
+    {
+      GError *error = NULL;
+
+      file_transfer_proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SESSION,
+                                                           G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES
+                                                           | G_DBUS_PROXY_FLAGS_DO_NOT_CONNECT_SIGNALS
+                                                           | G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
+                                                           NULL,
+                                                           "org.freedesktop.portal.Documents",
+                                                           "/org/freedesktop/portal/documents",
+                                                           "org.freedesktop.portal.FileTransfer",
+                                                           NULL, &error);
+
+      if (error)
+        {
+          g_debug ("Failed to get proxy: %s", error->message);
+          g_error_free (error);
+        }
+    }
+
+  if (file_transfer_proxy)
+    {
+      char *owner = g_dbus_proxy_get_name_owner (file_transfer_proxy);
+
+      if (owner)
+        {
+          g_free (owner);
+          return file_transfer_proxy;
+        }
+    }
+
+  return NULL;
+}
+
+gboolean
+file_transfer_portal_available (void)
+{
+  gboolean available;
+
+  ensure_file_transfer_portal ();
+
+  available = file_transfer_proxy != NULL;
+
+  g_clear_object (&file_transfer_proxy);
+
+  return available;
+}
+
+typedef struct {
+  GTask *task;
+  const char **files;
+  int len;
+  int start;
+} AddFileData;
+
+static void add_files (GDBusProxy  *proxy,
+                       AddFileData *afd);
+
+static void
+add_files_done (GObject      *object,
+                GAsyncResult *result,
+                gpointer      data)
+{
+  GDBusProxy *proxy = G_DBUS_PROXY (object);
+  AddFileData *afd = data;
+  GError *error = NULL;
+  GVariant *ret;
+
+  ret = g_dbus_proxy_call_with_unix_fd_list_finish (proxy, NULL, result, &error);
+  if (ret == NULL)
+    {
+      g_task_return_error (afd->task, error);
+      g_object_unref (afd->task);
+      g_free (afd);
+      return;
+    }
+
+  g_variant_unref (ret);
+
+  if (afd->start >= afd->len)
+    {
+      g_task_return_boolean (afd->task, TRUE);
+      g_object_unref (afd->task);
+      g_free (afd);
+      return;
+    }
+
+  add_files (proxy, afd);
+}
+
+/* We call AddFiles in chunks of 16 to avoid running into
+ * the per-message fd limit of the bus.
+ */
+static void
+add_files (GDBusProxy  *proxy,
+           AddFileData *afd)
+{
+  GUnixFDList *fd_list;
+  GVariantBuilder fds;
+  int i;
+  char *key;
+
+  g_variant_builder_init (&fds, G_VARIANT_TYPE ("ah"));
+  fd_list = g_unix_fd_list_new ();
+
+  for (i = 0; afd->files[afd->start + i]; i++)
+    {
+      int fd;
+      int fd_in;
+      GError *error = NULL;
+
+      if (i == 16)
+        break;
+
+      fd = open (afd->files[afd->start + i], O_PATH | O_CLOEXEC);
+      if (fd == -1)
+        {
+          g_task_return_new_error (afd->task, G_IO_ERROR, g_io_error_from_errno (errno),
+                                   "Failed to open %s", afd->files[afd->start + i]);
+          g_object_unref (afd->task);
+          g_free (afd);
+          g_object_unref (fd_list);
+          return;
+         }
+      fd_in = g_unix_fd_list_append (fd_list, fd, &error);
+      close (fd);
+
+      if (fd_in == -1)
+        {
+          g_task_return_error (afd->task, error);
+          g_object_unref (afd->task);
+          g_free (afd);
+          g_object_unref (fd_list);
+          return;
+        }
+
+      g_variant_builder_add (&fds, "h", fd_in);
+    }
+
+   afd->start += 16;
+
+  key = (char *)g_object_get_data (G_OBJECT (afd->task), "key");
+
+  g_dbus_proxy_call_with_unix_fd_list (proxy,
+                                       "AddFiles",
+                                       g_variant_new ("(sah)", key, &fds),
+                                       0, -1,
+                                       fd_list,
+                                       NULL,
+                                       add_files_done, afd);
+
+  g_object_unref (fd_list);
+}
+
+static void
+start_session_done (GObject      *object,
+                    GAsyncResult *result,
+                    gpointer      data)
+{
+  GDBusProxy *proxy = G_DBUS_PROXY (object);
+  AddFileData *afd = data;
+  GError *error = NULL;
+  GVariant *ret;
+  const char *key;
+
+  ret = g_dbus_proxy_call_finish (proxy, result, &error);
+  if (ret == NULL)
+    {
+      g_task_return_error (afd->task, error);
+      g_object_unref (afd->task);
+      g_free (afd);
+      return;
+    }
+
+  g_variant_get (ret, "(&s)", &key);
+
+  g_object_set_data_full (G_OBJECT (afd->task), "key", g_strdup (key), g_free);
+
+  g_variant_unref (ret);
+
+  add_files (proxy, afd);
+}
+
+void
+file_transfer_portal_register_files (const char          **files,
+                                     gboolean              writable,
+                                     GAsyncReadyCallback   callback,
+                                     gpointer              data)
+{
+  GTask *task;
+  GDBusProxy *proxy;
+  AddFileData *afd;
+  GVariantBuilder options;
+
+  task = g_task_new (NULL, NULL, callback, data);
+
+  proxy = ensure_file_transfer_portal ();
+
+  if (proxy == NULL)
+    {
+      g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                               "No portal found");
+      g_object_unref (task);
+      return;
+    }
+
+  afd = g_new (AddFileData, 1);
+  afd->task = task;
+  afd->files = files;
+  afd->len = g_strv_length ((char **)files);
+  afd->start = 0;
+
+  g_variant_builder_init (&options, G_VARIANT_TYPE_VARDICT);
+  g_variant_builder_add (&options, "{sv}", "writable", g_variant_new_boolean (writable));
+  g_variant_builder_add (&options, "{sv}", "autostop", g_variant_new_boolean (TRUE));
+
+  g_dbus_proxy_call (proxy, "StartTransfer",
+                     g_variant_new ("(a{sv})", &options),
+                     0, -1, NULL, start_session_done, afd);
+}
+
+gboolean
+file_transfer_portal_register_files_finish (GAsyncResult  *result,
+                                            char         **key,
+                                            GError       **error)
+{
+  if (g_task_propagate_boolean (G_TASK (result), error))
+    {
+      *key = g_strdup (g_object_get_data (G_OBJECT (result), "key"));
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+retrieve_files_done (GObject      *object,
+                     GAsyncResult *result,
+                     gpointer      data)
+{
+  GDBusProxy *proxy = G_DBUS_PROXY (object);
+  GTask *task = data;
+  GError *error = NULL;
+  GVariant *ret;
+  char **files;
+
+  ret = g_dbus_proxy_call_finish (proxy, result, &error);
+  if (ret == NULL)
+    {
+      g_task_return_error (task, error);
+      g_object_unref (task);
+      return;
+    }
+
+  g_variant_get (ret, "(^a&s)", &files);
+
+  g_object_set_data_full (G_OBJECT (task), "files", g_strdupv (files), (GDestroyNotify)g_strfreev);
+
+  g_variant_unref (ret);
+
+  g_task_return_boolean (task, TRUE);
+}
+
+void
+file_transfer_portal_retrieve_files (const char          *key,
+                                     GAsyncReadyCallback  callback,
+                                     gpointer             data)
+{
+  GDBusProxy *proxy;
+  GTask *task;
+  GVariantBuilder options;
+
+  task = g_task_new (NULL, NULL, callback, data);
+
+  proxy = ensure_file_transfer_portal ();
+
+  if (proxy == NULL)
+    {
+      g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                               "No portal found");
+      g_object_unref (task);
+      return;
+    }
+
+  g_variant_builder_init (&options, G_VARIANT_TYPE_VARDICT);
+  g_dbus_proxy_call (proxy,
+                     "RetrieveFiles",
+                     g_variant_new ("(sa{sv})", key, &options),
+                     0, -1, NULL,
+                     retrieve_files_done, task);
+}
+
+gboolean
+file_transfer_portal_retrieve_files_finish (GAsyncResult   *result,
+                                            char         ***files,
+                                            GError        **error)
+{
+  if (g_task_propagate_boolean (G_TASK (result), error))
+    {
+      *files = g_strdupv (g_object_get_data (G_OBJECT (result), "files"));
+      return TRUE;
+    }
+
+  return FALSE;
+}