support: Helper functions for entering namespaces

1 files changed, 53 insertions, 0 deletions

diff --git a/support/namespace.h b/support/namespace.h
new file mode 100644
index 0000000000..4692907676
--- /dev/null
+++ b/support/namespace.h
@@ -0,0 +1,53 @@
+/* Entering namespaces for test case isolation.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C 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.
+
+   The GNU C 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 the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_NAMESPACE_H
+#define SUPPORT_NAMESPACE_H
+
+#include <stdbool.h>
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+/* Attempts to become root (or acquire root-like privileges), possibly
+   with the help of user namespaces.  Return true if (restricted) root
+   privileges could be attained in some way.  Print diagnostics to
+   standard output.
+
+   Note that this function generally has to be called before a process
+   becomes multi-threaded, otherwise it may fail with insufficient
+   privileges on systems which would support this operation for
+   single-threaded processes.  */
+bool support_become_root (void);
+
+/* Enter a network namespace (and a UTS namespace if possible) and
+   configure the loopback interface.  Return true if a network
+   namespace could be created.  Print diagnostics to standard output.
+   If a network namespace could be created, but networking in it could
+   not be configured, terminate the process.  It is recommended to
+   call support_become_root before this function so that the process
+   has sufficient privileges.  */
+bool support_enter_network_namespace (void);
+
+/* Return true if support_enter_network_namespace managed to enter a
+   UTS namespace.  */
+bool support_in_uts_namespace (void);
+
+__END_DECLS
+
+#endif