[gdm] simple-slave: Change g-i-s' home directory ownership to created user

[Rui Matos <rtcm src gnome org>]

commit 3f7ac6f865cccd77a2b632fa55667f9168947c2b
Author: Rui Matos <tiagomatos gmail com>
Date:   Sun Jun 2 19:45:48 2013 +0200

    simple-slave: Change g-i-s' home directory ownership to created user
    
    We do this at the end of the gnome-initial-setup special session,
    before logging in to the newly created user account.
    
    This allows the user session's gnome-initial-setup instance to
    manipulate files here.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=701473

 daemon/gdm-simple-slave.c |  123 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 123 insertions(+), 0 deletions(-)
---
diff --git a/daemon/gdm-simple-slave.c b/daemon/gdm-simple-slave.c
index d61c62e..df586ce 100644
--- a/daemon/gdm-simple-slave.c
+++ b/daemon/gdm-simple-slave.c
@@ -104,6 +104,7 @@ struct GdmSimpleSlavePrivate
 #ifdef  WITH_PLYMOUTH
         guint              plymouth_is_running : 1;
 #endif
+        guint              doing_initial_setup : 1;
 };
 
 enum {
@@ -129,6 +130,123 @@ static void start_session      (GdmSimpleSlave  *slave);
 static void queue_start_session (GdmSimpleSlave *slave,
                                  const char     *service_name);
 
+static gboolean
+chown_file (GFile   *file,
+            uid_t    uid,
+            gid_t    gid,
+            GError **error)
+{
+        if (!g_file_set_attribute_uint32 (file, G_FILE_ATTRIBUTE_UNIX_UID, uid,
+                                          G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+                                          NULL, error)) {
+                return FALSE;
+        }
+        if (!g_file_set_attribute_uint32 (file, G_FILE_ATTRIBUTE_UNIX_GID, gid,
+                                          G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+                                          NULL, error)) {
+                return FALSE;
+        }
+        return TRUE;
+}
+
+static gboolean
+chown_recursively (GFile   *dir,
+                   uid_t    uid,
+                   gid_t    gid,
+                   GError **error)
+{
+        GFile *file = NULL;
+        GFileInfo *info = NULL;
+        GFileEnumerator *enumerator = NULL;
+        gboolean retval = FALSE;
+
+        if (chown_file (dir, uid, gid, error) == FALSE) {
+                goto out;
+        }
+
+        enumerator = g_file_enumerate_children (dir,
+                                                G_FILE_ATTRIBUTE_STANDARD_TYPE","
+                                                G_FILE_ATTRIBUTE_STANDARD_NAME,
+                                                G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
+                                                NULL, error);
+        if (!enumerator) {
+                goto out;
+        }
+
+        while ((info = g_file_enumerator_next_file (enumerator, NULL, error)) != NULL) {
+                file = g_file_get_child (dir, g_file_info_get_name (info));
+
+                if (g_file_info_get_file_type (info) == G_FILE_TYPE_DIRECTORY) {
+                        if (chown_recursively (file, uid, gid, error) == FALSE) {
+                                goto out;
+                        }
+                } else if (chown_file (file, uid, gid, error) == FALSE) {
+                        goto out;
+                }
+
+                g_clear_object (&file);
+                g_clear_object (&info);
+        }
+
+        if (*error) {
+                goto out;
+        }
+
+        retval = TRUE;
+out:
+        g_clear_object (&file);
+        g_clear_object (&info);
+        g_clear_object (&enumerator);
+
+        return retval;
+}
+
+static void
+chown_initial_setup_home_dir (void)
+{
+        GFile *dir;
+        GError *error;
+        char *gis_dir_path;
+        char *gis_uid_path;
+        char *gis_uid_contents;
+        struct passwd *pwe;
+        uid_t uid;
+
+        if (!gdm_get_pwent_for_name (INITIAL_SETUP_USERNAME, &pwe)) {
+                g_warning ("Unknown user %s", INITIAL_SETUP_USERNAME);
+                return;
+        }
+
+        gis_dir_path = g_strdup (pwe->pw_dir);
+
+        gis_uid_path = g_build_filename (gis_dir_path,
+                                         "gnome-initial-setup-uid",
+                                         NULL);
+        if (!g_file_get_contents (gis_uid_path, &gis_uid_contents, NULL, NULL)) {
+                g_warning ("Unable to read %s", gis_uid_path);
+                goto out;
+        }
+
+        uid = (uid_t) atoi (gis_uid_contents);
+        pwe = getpwuid (uid);
+        if (uid == 0 || pwe == NULL) {
+                g_warning ("UID '%s' in %s is not valid", gis_uid_contents, gis_uid_path);
+                goto out;
+        }
+
+        error = NULL;
+        dir = g_file_new_for_path (gis_dir_path);
+        if (!chown_recursively (dir, pwe->pw_uid, pwe->pw_gid, &error)) {
+                g_warning ("Failed to change ownership for %s: %s", gis_dir_path, error->message);
+                g_error_free (error);
+        }
+        g_object_unref (dir);
+out:
+        g_free (gis_uid_contents);
+        g_free (gis_uid_path);
+        g_free (gis_dir_path);
+}
+
 static void
 on_session_started (GdmSession       *session,
                     const char       *service_name,
@@ -385,6 +503,10 @@ start_session (GdmSimpleSlave  *slave)
 
         g_free (auth_file);
 
+        if (slave->priv->doing_initial_setup) {
+                chown_initial_setup_home_dir ();
+        }
+
         gdm_session_start_session (slave->priv->session,
                                    slave->priv->start_session_service_name);
 
@@ -1166,6 +1288,7 @@ start_greeter (GdmSimpleSlave *slave)
 static void
 start_initial_setup (GdmSimpleSlave *slave)
 {
+        slave->priv->doing_initial_setup = TRUE;
         start_launch_environment (slave, INITIAL_SETUP_USERNAME, "gnome-initial-setup");
 }