SETNS
Section: Linux Programmer's Manual (2)
Updated: 2011-10-04
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NAME
setns - reassociate thread with a namespace
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <sched.h>
int setns(int fd, int nstype);
DESCRIPTION
Given a file descriptor referring to a namespace,
reassociate the calling thread with that namespace.
The
fd
argument is a file descriptor referring to one of the namespace entries in a
/proc/[pid]/ns/
directory; see
proc(5)
for further information on
/proc/[pid]/ns/.
The calling thread will be reassociated with the corresponding namespace,
subject to any constraints imposed by the
nstype
argument.
The
nstype
argument specifies which type of namespace
the calling thread may be reassociated with.
This argument can have one of the following values:
- 0
-
Allow any type of namespace to be joined.
- CLONE_NEWIPC
-
fd
must refer to an IPC namespace.
- CLONE_NEWNET
-
fd
must refer to a network namespace.
- CLONE_NEWUTS
-
fd
must refer to a UTS namespace.
Specifying
nstype
as 0 suffices if the caller knows (or does not care)
what type of namespace is referred to by
fd.
Specifying a nonzero value for
nstype
is useful if the caller does not know what type of namespace is referred to by
fd
and wants to ensure that the namespace is of a particular type.
(The caller might not know the type of the namespace referred to by
fd
if the file descriptor was opened by another process and, for example,
passed to the caller via a UNIX domain socket.)
RETURN VALUE
On success,
setns()
returns 0.
On failure, -1 is returned and
errno
is set to indicate the error.
ERRORS
- EBADF
-
fd
is not a valid file descriptor.
- EINVAL
-
fd
refers to a namespace whose type does not match that specified in
nstype,
or there is problem with reassociating the
the thread with the specified namespace.
- ENOMEM
-
Cannot allocate sufficient memory to change the specified namespace.
- EPERM
-
The calling thread did not have the required privilege
(CAP_SYS_ADMIN)
for this operation.
VERSIONS
The
setns()
system call first appeared in Linux in kernel 3.0
CONFORMING TO
The
setns()
system call is Linux-specific.
NOTES
Not all of the attributes that can be shared when
a new thread is created using
clone(2)
can be changed using
setns().
BUGS
The PID namespace and the mount namespace are not currently supported.
(See the descriptions of
CLONE_NEWPID
and
CLONE_NEWNS
in
clone(2).)
SEE ALSO
clone(2),
fork(2),
vfork(2),
proc(5),
unix(7)
COLOPHON
This page is part of release 3.35 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://man7.org/linux/man-pages/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- VERSIONS
-
- CONFORMING TO
-
- NOTES
-
- BUGS
-
- SEE ALSO
-
- COLOPHON
-
© Andrew Scott 2006 -
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