libvirt/python/libvirt-lxc-override.c
Daniel P. Berrange 3d1596b048 Introduce an LXC specific public API & library
This patch introduces support for LXC specific public APIs. In
common with what was done for QEMU, this creates a libvirt_lxc.so
library and libvirt/libvirt-lxc.h header file.

The actual APIs are

  int virDomainLxcOpenNamespace(virDomainPtr domain,
                                int **fdlist,
                                unsigned int flags);

  int virDomainLxcEnterNamespace(virDomainPtr domain,
                                 unsigned int nfdlist,
                                 int *fdlist,
                                 unsigned int *noldfdlist,
                                 int **oldfdlist,
                                 unsigned int flags);

which provide a way to use the setns() system call to move the
calling process into the container's namespace. It is not
practical to write in a generically applicable manner. The
nearest that we could get to such an API would be an API which
allows to pass a command + argv to be executed inside a
container. Even if we had such a generic API, this LXC specific
API is still useful, because it allows the caller to maintain
the current process context, in particular any I/O streams they
have open.

NB the virDomainLxcEnterNamespace() API is special in that it
runs client side, so does not involve the internal driver API.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-01-14 13:58:34 +00:00

142 lines
3.6 KiB
C

/*
* libvir.c: this modules implements the main part of the glue of the
* libvir library and the Python interpreter. It provides the
* entry points where an automatically generated stub is
* unpractical
*
* Copyright (C) 2012-2013 Red Hat, Inc.
*
* Daniel Veillard <veillard@redhat.com>
*/
#include <config.h>
/* Horrible kludge to work around even more horrible name-space pollution
via Python.h. That file includes /usr/include/python2.5/pyconfig*.h,
which has over 180 autoconf-style HAVE_* definitions. Shame on them. */
#undef HAVE_PTHREAD_H
#include <Python.h>
#include "libvirt/libvirt-lxc.h"
#include "libvirt/virterror.h"
#include "typewrappers.h"
#include "libvirt-lxc.h"
#include "viralloc.h"
#include "virfile.h"
#ifndef __CYGWIN__
extern void initlibvirtmod_lxc(void);
#else
extern void initcygvirtmod_lxc(void);
#endif
#if 0
# define DEBUG_ERROR 1
#endif
#if DEBUG_ERROR
# define DEBUG(fmt, ...) \
printf(fmt, __VA_ARGS__)
#else
# define DEBUG(fmt, ...) \
do {} while (0)
#endif
/* The two-statement sequence "Py_INCREF(Py_None); return Py_None;"
is so common that we encapsulate it here. Now, each use is simply
return VIR_PY_NONE; */
#define VIR_PY_NONE (Py_INCREF (Py_None), Py_None)
#define VIR_PY_INT_FAIL (libvirt_intWrap(-1))
#define VIR_PY_INT_SUCCESS (libvirt_intWrap(0))
/************************************************************************
* *
* Statistics *
* *
************************************************************************/
static PyObject *
libvirt_lxc_virDomainLxcOpenNamespace(PyObject *self ATTRIBUTE_UNUSED,
PyObject *args) {
PyObject *py_retval;
virDomainPtr domain;
PyObject *pyobj_domain;
unsigned int flags;
int c_retval;
int *fdlist = NULL;
int i;
if (!PyArg_ParseTuple(args, (char *)"Oi:virDomainLxcOpenNamespace",
&pyobj_domain, &flags))
return NULL;
domain = (virDomainPtr) PyvirDomain_Get(pyobj_domain);
if (domain == NULL)
return VIR_PY_NONE;
LIBVIRT_BEGIN_ALLOW_THREADS;
c_retval = virDomainLxcOpenNamespace(domain, &fdlist, flags);
LIBVIRT_END_ALLOW_THREADS;
if (c_retval < 0)
return VIR_PY_NONE;
py_retval = PyList_New(c_retval);
for (i = 0 ; i < c_retval ; i++) {
PyObject *item = NULL;
if ((item = PyInt_FromLong(fdlist[i])) == NULL)
goto error;
if (PyList_Append(py_retval, item) < 0) {
Py_DECREF(item);
goto error;
}
}
return py_retval;
error:
for (i = 0 ; i < c_retval ; i++) {
VIR_FORCE_CLOSE(fdlist[i]);
}
VIR_FREE(fdlist);
return VIR_PY_NONE;
}
/************************************************************************
* *
* The registration stuff *
* *
************************************************************************/
static PyMethodDef libvirtLxcMethods[] = {
#include "libvirt-lxc-export.c"
{(char *) "virDomainLxcOpenNamespace", libvirt_lxc_virDomainLxcOpenNamespace, METH_VARARGS, NULL},
{NULL, NULL, 0, NULL}
};
void
#ifndef __CYGWIN__
initlibvirtmod_lxc
#else
initcygvirtmod_lxc
#endif
(void)
{
static int initialized = 0;
if (initialized != 0)
return;
if (virInitialize() < 0)
return;
/* initialize the python extension module */
Py_InitModule((char *)
#ifndef __CYGWIN__
"libvirtmod_lxc"
#else
"cygvirtmod_lxc"
#endif
, libvirtLxcMethods);
initialized = 1;
}