glibc/support/support_enter_mount_namespace.c

48 lines
1.5 KiB
C

/* Enter a mount namespace.
Copyright (C) 2017-2023 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
<https://www.gnu.org/licenses/>. */
#include <support/namespace.h>
#include <sched.h>
#include <stdio.h>
#ifdef CLONE_NEWNS
# include <sys/mount.h>
#endif /* CLONE_NEWNS */
bool
support_enter_mount_namespace (void)
{
#ifdef CLONE_NEWNS
if (unshare (CLONE_NEWNS) == 0)
{
/* On some systems, / is marked as MS_SHARED, which means that
mounts within the namespace leak to the rest of the system,
which is not what we want. */
if (mount ("none", "/", NULL, MS_REC | MS_PRIVATE, NULL) != 0)
{
printf ("warning: making the mount namespace private failed: %m\n");
return false;
}
return true;
}
else
printf ("warning: unshare (CLONE_NEWNS) failed: %m\n");
#endif /* CLONE_NEWNS */
return false;
}