Fix compilation in --disable-selinux case

_dbus_change_to_daemon_user moved into selinux.c for the --with-selinux
(and audit) case because that's where all of the relevant libcap headers
were being used.  However in the --disable-selinux case this didn't
compile and wasn't very clean.

If we don't have libaudit, use the legacy direct setgid/setuid bits
we had before in dbus-sysdeps-util-unix.c.

bus/selinux.c

@@ -1017,6 +1017,8 @@ bus_selinux_shutdown (void)
 #endif /* HAVE_SELINUX */
 }
 
+/* The !HAVE_LIBAUDIT case lives in dbus-sysdeps-util-unix.c */
+#ifdef HAVE_LIBAUDIT
 /**
  * Changes the user and group the bus is running as.
  *
@@ -1042,7 +1044,6 @@ _dbus_change_to_daemon_user  (const char    *user,
       return FALSE;
     }
 
-#ifdef HAVE_LIBAUDIT
   /* If we were root */
   if (_dbus_geteuid () == 0)
     {
@@ -1083,38 +1084,8 @@ _dbus_change_to_daemon_user  (const char    *user,
           return FALSE;
         }
     }
-#else
-  /* setgroups() only works if we are a privileged process,
-   * so we don't return error on failure; the only possible
-   * failure is that we don't have perms to do it.
-   *
-   * not sure this is right, maybe if setuid()
-   * is going to work then setgroups() should also work.
-   */
-  if (setgroups (0, NULL) < 0)
-    _dbus_warn ("Failed to drop supplementary groups: %s\n",
-                _dbus_strerror (errno));
-
-  /* Set GID first, or the setuid may remove our permission
-   * to change the GID
-   */
-  if (setgid (gid) < 0)
-    {
-      dbus_set_error (error, _dbus_error_from_errno (errno),
-                      "Failed to set GID to %lu: %s", gid,
-                      _dbus_strerror (errno));
-      return FALSE;
-    }
-
-  if (setuid (uid) < 0)
-    {
-      dbus_set_error (error, _dbus_error_from_errno (errno),
-                      "Failed to set UID to %lu: %s", uid,
-                      _dbus_strerror (errno));
-      return FALSE;
-    }
-#endif /* !HAVE_LIBAUDIT */
 
  return TRUE;
 }
+#endif
 

bus/selinux.h

@@ -68,7 +68,5 @@ BusSELinuxID* bus_selinux_init_connection_id (DBusConnection *connection,
 
 
 void bus_selinux_audit_init(void);
-dbus_bool_t _dbus_change_to_daemon_user (const char *user,
-                                         DBusError  *error);
 
 #endif /* BUS_SELINUX_H */

dbus/dbus-sysdeps-util-unix.c

@@ -303,6 +303,68 @@ _dbus_verify_daemon_user (const char *user)
   return _dbus_get_user_id_and_primary_group (&u, NULL, NULL);
 }
 
+
+/* The HAVE_LIBAUDIT case lives in selinux.c */
+#ifndef HAVE_LIBAUDIT
+/**
+ * Changes the user and group the bus is running as.
+ *
+ * @param user the user to become
+ * @param error return location for errors
+ * @returns #FALSE on failure
+ */
+dbus_bool_t
+_dbus_change_to_daemon_user  (const char    *user,
+                              DBusError     *error)
+{
+  dbus_uid_t uid;
+  dbus_gid_t gid;
+  DBusString u;
+
+  _dbus_string_init_const (&u, user);
+
+  if (!_dbus_get_user_id_and_primary_group (&u, &uid, &gid))
+    {
+      dbus_set_error (error, DBUS_ERROR_FAILED,
+                      "User '%s' does not appear to exist?",
+                      user);
+      return FALSE;
+    }
+
+  /* setgroups() only works if we are a privileged process,
+   * so we don't return error on failure; the only possible
+   * failure is that we don't have perms to do it.
+   *
+   * not sure this is right, maybe if setuid()
+   * is going to work then setgroups() should also work.
+   */
+  if (setgroups (0, NULL) < 0)
+    _dbus_warn ("Failed to drop supplementary groups: %s\n",
+                _dbus_strerror (errno));
+
+  /* Set GID first, or the setuid may remove our permission
+   * to change the GID
+   */
+  if (setgid (gid) < 0)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to set GID to %lu: %s", gid,
+                      _dbus_strerror (errno));
+      return FALSE;
+    }
+
+  if (setuid (uid) < 0)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to set UID to %lu: %s", uid,
+                      _dbus_strerror (errno));
+      return FALSE;
+    }
+
+  return TRUE;
+}
+#endif /* !HAVE_LIBAUDIT */
+
 void 
 _dbus_init_system_log (void)
 {

dbus/dbus-sysdeps.h

@@ -512,6 +512,9 @@ unsigned long _dbus_pid_for_log (void);
  */
 dbus_pid_t    _dbus_getpid (void);
 
+dbus_bool_t _dbus_change_to_daemon_user (const char *user,
+                                         DBusError  *error);
+
 void _dbus_flush_caches (void);
 
 /** @} */