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/* Entering namespaces for test case isolation.
Copyright (C) 2016-2020 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/>. */
#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);
/* Return true if this process can perform a chroot operation. In
general, this is only possible if support_become_root has been
called. Note that the actual test is performed in a subprocess,
after fork, so that the file system root of the original process is
not changed. */
bool support_can_chroot (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);
/* Enter a mount namespace and mark / as private (not shared). If
this function returns true, mount operations in this process will
not affect the host system afterwards. */
bool support_enter_mount_namespace (void);
/* Return true if support_enter_network_namespace managed to enter a
UTS namespace. */
bool support_in_uts_namespace (void);
/* Invoke CALLBACK (CLOSURE) in a subprocess created using fork.
Terminate the calling process if the subprocess exits with a
non-zero exit status. */
void support_isolate_in_subprocess (void (*callback) (void *), void *closure);
/* Describe the setup of a chroot environment, for
support_chroot_create below. */
struct support_chroot_configuration
{
/* File contents. The files are not created if the field is
NULL. */
const char *resolv_conf; /* /etc/resolv.conf. */
const char *hosts; /* /etc/hosts. */
const char *host_conf; /* /etc/host.conf. */
const char *aliases; /* /etc/aliases. */
};
/* The result of the creation of a chroot. */
struct support_chroot
{
/* Path information. All these paths are relative to the parent
chroot. */
/* Path to the chroot directory. */
char *path_chroot;
/* Paths to files in the chroot. These are absolute and outside of
the chroot. */
char *path_resolv_conf; /* /etc/resolv.conf. */
char *path_hosts; /* /etc/hosts. */
char *path_host_conf; /* /etc/host.conf. */
char *path_aliases; /* /etc/aliases. */
};
/* Create a chroot environment. The returned data should be freed
using support_chroot_free below. The files will be deleted when
the process exits. This function does not enter the chroot. */
struct support_chroot *support_chroot_create
(struct support_chroot_configuration);
/* Deallocate the chroot information created by
support_chroot_create. */
void support_chroot_free (struct support_chroot *);
__END_DECLS
#endif
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