Use AccountsService extension system for extended greeter information (background, messages etc)

The support for this never landed upstream in AccountsService and the extension
system was added later. This allows OSs to make use of these features without a
patched AccountsService.

Author: robert-ancell

common/user-list.c

@@ -494,6 +494,7 @@ load_accounts_user (CommonUser *user)
 {
     CommonUserPrivate *priv = GET_USER_PRIVATE (user);
     g_autoptr(GVariant) result = NULL;
+    g_autoptr(GVariant) extra_result = NULL;
     GVariant *value;
     GVariantIter *iter;
     gchar *name;
@@ -572,29 +573,50 @@ load_accounts_user (CommonUser *user)
             g_free (priv->session);
             priv->session = g_variant_dup_string (value, NULL);
         }
-        else if (strcmp (name, "BackgroundFile") == 0 && g_variant_is_of_type (value, G_VARIANT_TYPE_STRING))
-        {
-            g_free (priv->background);
-            priv->background = g_variant_dup_string (value, NULL);
-            if (strcmp (priv->background, "") == 0)
-                g_clear_pointer (&priv->background, g_free);
-        }
-        else if (strcmp (name, "XKeyboardLayouts") == 0 && g_variant_is_of_type (value, G_VARIANT_TYPE_STRING_ARRAY))
+        else if (strcmp (name, "Uid") == 0 && g_variant_is_of_type (value, G_VARIANT_TYPE_UINT64))
+            priv->uid = g_variant_get_uint64 (value);
+    }
+    g_variant_iter_free (iter);
+
+    extra_result = g_dbus_connection_call_sync (priv->bus,
+                                                "org.freedesktop.Accounts",
+                                                priv->path,
+                                                "org.freedesktop.DBus.Properties",
+                                                "GetAll",
+                                                g_variant_new ("(s)", "org.freedesktop.DisplayManager.AccountsService"),
+                                                G_VARIANT_TYPE ("(a{sv})"),
+                                                G_DBUS_CALL_FLAGS_NONE,
+                                                -1,
+                                                NULL,
+                                                &error);
+    if (error)
+        g_warning ("Error updating user %s: %s", priv->path, error->message);
+    if (extra_result) {
+        g_variant_get (extra_result, "(a{sv})", &iter);
+        while (g_variant_iter_loop (iter, "{&sv}", &name, &value))
         {
-            g_strfreev (priv->layouts);
-            priv->layouts = g_variant_dup_strv (value, NULL);
-            if (!priv->layouts)
+            if (strcmp (name, "BackgroundFile") == 0 && g_variant_is_of_type (value, G_VARIANT_TYPE_STRING))
+            {
+                g_free (priv->background);
+                priv->background = g_variant_dup_string (value, NULL);
+                if (strcmp (priv->background, "") == 0)
+                    g_clear_pointer (&priv->background, g_free);
+            }
+            else if (strcmp (name, "HasMessages") == 0 && g_variant_is_of_type (value, G_VARIANT_TYPE_BOOLEAN))
+                priv->has_messages = g_variant_get_boolean (value);
+            else if (strcmp (name, "XKeyboardLayouts") == 0 && g_variant_is_of_type (value, G_VARIANT_TYPE_STRING_ARRAY))
             {
-                priv->layouts = g_malloc (sizeof (gchar *) * 1);
-                priv->layouts[0] = NULL;
+                g_strfreev (priv->layouts);
+                priv->layouts = g_variant_dup_strv (value, NULL);
+                if (!priv->layouts)
+                {
+                    priv->layouts = g_malloc (sizeof (gchar *) * 1);
+                    priv->layouts[0] = NULL;
+                }
             }
         }
-        else if (strcmp (name, "XHasMessages") == 0 && g_variant_is_of_type (value, G_VARIANT_TYPE_BOOLEAN))
-            priv->has_messages = g_variant_get_boolean (value);
-        else if (strcmp (name, "Uid") == 0 && g_variant_is_of_type (value, G_VARIANT_TYPE_UINT64))
-            priv->uid = g_variant_get_uint64 (value);
+        g_variant_iter_free (iter);
     }
-    g_variant_iter_free (iter);
 
     return !system_account;
 }

data/Makefile.am

@@ -27,8 +27,17 @@ dist_apparmor_profile_abstractions_DATA = \
     apparmor/abstractions/lightdm \
     apparmor/abstractions/lightdm_chromium-browser
 
+accountsservicedir = $(datadir)/accountsservice/interfaces
+dist_accountsservice_DATA = \
+    org.freedesktop.DisplayManager.AccountsService.xml
+
+polkitdir = $(datadir)/polkit-1/actions
+polkit_in_files = org.freedesktop.DisplayManager.AccountsService.policy
+polkit_DATA = $(polkit_in_files:.policy.in=.policy)
+@INTLTOOL_POLICY_RULE@
+
 dist_man1_MANS = dm-tool.1 \
                  lightdm.1
 
-EXTRA_DIST = apparmor/lightdm-guest-session.in
-CLEANFILES = lightdm-guest-session
+EXTRA_DIST = apparmor/lightdm-guest-session.in $(polkit_in_files)
+CLEANFILES = lightdm-guest-session $(polkit_DATA)

data/org.freedesktop.DisplayManager.AccountsService.policy.in

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<policyconfig>
+        <action id="org.freedesktop.DisplayManager.AccountsService.ModifyOwn">
+                <_description>Set properties of own user</_description>
+                <_message>Authentication is required to set one's own greeter properties.</_message>
+                <defaults>
+                        <allow_any>yes</allow_any>
+                        <allow_inactive>yes</allow_inactive>
+                        <allow_active>yes</allow_active>
+                </defaults>
+        </action>
+
+        <action id="org.freedesktop.DisplayManager.AccountsService.ReadAny">
+                <_description>Set properties of any user</_description>
+                <_message>Authentication is required to get another user's greeter properties.</_message>
+                <defaults>
+                        <allow_any>yes</allow_any>
+                        <allow_inactive>yes</allow_inactive>
+                        <allow_active>yes</allow_active>
+                </defaults>
+        </action>
+
+        <action id="org.freedesktop.DisplayManager.AccountsService.ModifyAny">
+                <_description>Set properties of any user</_description>
+                <_message>Authentication is required to set another user's greeter properties.</_message>
+                <defaults>
+                        <allow_any>no</allow_any>
+                        <allow_inactive>no</allow_inactive>
+                        <allow_active>no</allow_active>
+                </defaults>
+        </action>
+</policyconfig>

data/org.freedesktop.DisplayManager.AccountsService.xml

@@ -0,0 +1,26 @@
+<node>
+  <interface name="org.freedesktop.DisplayManager.AccountsService">
+
+    <annotation name="org.freedesktop.Accounts.VendorExtension" value="true"/>
+
+    <annotation name="org.freedesktop.Accounts.Authentication.ChangeOwn"
+                value="org.freedesktop.DisplayManager.AccountsService.ModifyOwn"/>
+
+    <annotation name="org.freedesktop.Accounts.Authentication.ReadAny"
+                value="org.freedesktop.DisplayManager.AccountsService.ReadAny"/>
+
+    <annotation name="org.freedesktop.Accounts.Authentication.ChangeAny"
+                value="org.freedesktop.DisplayManager.AccountsService.ModifyAny"/>
+
+    <property name="BackgroundFile" type="s" access="readwrite">
+      <annotation name="org.freedesktop.Accounts.DefaultValue" value=""/>
+    </property>
+    <property name="HasMessages" type="b" access="readwrite">
+      <annotation name="org.freedesktop.Accounts.DefaultValue" value="false"/>
+    </property>
+    <property name="BackgroundFile" type="s" access="readwrite">
+      <annotation name="org.freedesktop.Accounts.DefaultValue" value=""/>
+    </property>
+
+  </interface>
+</node>

debian/lightdm.install

@@ -1,7 +1,9 @@
 usr/sbin/lightdm
+usr/share/accountsservice
+usr/share/bash-completion
 usr/share/man
 usr/share/locale
-usr/share/bash-completion
+usr/share/polkit-1
 usr/lib/lightdm
 usr/bin
 etc/dbus-1/

po/POTFILES.in

@@ -1,5 +1,6 @@
 # List of source files containing translatable strings.
 # Please keep this file sorted alphabetically.
 [encoding: UTF-8]
+data/org.freedesktop.DisplayManager.AccountsService.policy.in
 src/lightdm.c
 src/dm-tool.c

tests/src/test-runner.c

@@ -52,6 +52,7 @@ typedef struct
     gchar *background;
     gchar *path;
     guint id;
+    guint extra_id;
     gchar *language;
     gchar *xsession;
     gchar **layouts;
@@ -2122,8 +2123,6 @@ handle_user_get_property (GDBusConnection       *connection,
         return g_variant_new_string (user->home_directory);
     else if (strcmp (property_name, "SystemAccount") == 0)
         return g_variant_new_boolean (user->uid < 1000);
-    else if (strcmp (property_name, "BackgroundFile") == 0)
-        return g_variant_new_string (user->background ? user->background : "");
     else if (strcmp (property_name, "Language") == 0)
         return g_variant_new_string (user->language ? user->language : "");
     else if (strcmp (property_name, "IconFile") == 0)
@@ -2134,15 +2133,32 @@ handle_user_get_property (GDBusConnection       *connection,
         return g_variant_new_uint64 (user->uid);
     else if (strcmp (property_name, "XSession") == 0)
         return g_variant_new_string (user->xsession ? user->xsession : "");
+
+    return NULL;
+}
+
+static GVariant *
+handle_user_get_extra_property (GDBusConnection       *connection,
+                                const gchar           *sender,
+                                const gchar           *object_path,
+                                const gchar           *interface_name,
+                                const gchar           *property_name,
+                                GError               **error,
+                                gpointer               user_data)
+{
+    AccountsUser *user = user_data;
+
+    if (strcmp (property_name, "BackgroundFile") == 0)
+        return g_variant_new_string (user->background ? user->background : "");
+    else if (strcmp (property_name, "HasMessages") == 0)
+        return g_variant_new_boolean (user->has_messages);
     else if (strcmp (property_name, "XKeyboardLayouts") == 0)
     {
         if (user->layouts != NULL)
             return g_variant_new_strv ((const gchar * const *) user->layouts, -1);
         else
             return g_variant_new_strv (NULL, 0);
     }
-    else if (strcmp (property_name, "XHasMessages") == 0)
-        return g_variant_new_boolean (user->has_messages);
 
     return NULL;
 }
@@ -2157,6 +2173,7 @@ accounts_user_set_hidden (AccountsUser *user, gboolean hidden, gboolean emit_sig
         g_autoptr(GError) error = NULL;
 
         g_dbus_connection_unregister_object (accounts_connection, user->id);
+        g_dbus_connection_unregister_object (accounts_connection, user->extra_id);
         if (!g_dbus_connection_emit_signal (accounts_connection,
                                             NULL,
                                             "/org/freedesktop/Accounts",
@@ -2185,12 +2202,12 @@ accounts_user_set_hidden (AccountsUser *user, gboolean hidden, gboolean emit_sig
             "    <property name='Shell' type='s' access='read'/>"
             "    <property name='Uid' type='t' access='read'/>"
             "    <property name='XSession' type='s' access='read'/>"
-            "    <property name='XKeyboardLayouts' type='as' access='read'/>"
             "    <signal name='Changed' />"
             "  </interface>"
             "  <interface name='org.freedesktop.DisplayManager.AccountsService'>"
             "    <property name='BackgroundFile' type='s' access='read'/>"
             "    <property name='HasMessages' type='b' access='read'/>"
+            "    <property name='XKeyboardLayouts' type='as' access='read'/>"
             "  </interface>"
             "</node>";
         g_autoptr(GDBusNodeInfo) user_info = NULL;
@@ -2200,6 +2217,11 @@ accounts_user_set_hidden (AccountsUser *user, gboolean hidden, gboolean emit_sig
             handle_user_call,
             handle_user_get_property,
         };
+        static const GDBusInterfaceVTable user_extra_vtable =
+        {
+            NULL,
+            handle_user_get_extra_property,
+        };
 
         user_info = g_dbus_node_info_new_for_xml (user_interface, &error);
         if (!user_info)
@@ -2219,6 +2241,18 @@ accounts_user_set_hidden (AccountsUser *user, gboolean hidden, gboolean emit_sig
             g_warning ("Failed to register user: %s", error->message);
             return;
         }
+        user->extra_id = g_dbus_connection_register_object (accounts_connection,
+                                                            user->path,
+                                                            user_info->interfaces[1],
+                                                            &user_extra_vtable,
+                                                            user,
+                                                            NULL,
+                                                            &error);
+        if (user->extra_id == 0)
+        {
+            g_warning ("Failed to register user: %s", error->message);
+            return;
+        }
 
         if (!g_dbus_connection_emit_signal (accounts_connection,
                                             NULL,