Files
alcove/c_src/sys/setns.c
2015-07-24 10:52:06 -04:00

101 lines
2.3 KiB
C

/* Copyright (c) 2014, Michael Santos <michael.santos@gmail.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifdef __linux__
#define _GNU_SOURCE
#include <sched.h>
#ifndef HAVE_SETNS
#include <syscall.h>
#endif
#endif
#include "alcove.h"
#include "alcove_call.h"
#include "alcove_fork.h"
#include "alcove_clone_constants.h"
#ifdef __linux__
#ifndef HAVE_SETNS
static int setns(int fd, int nstype);
#endif
#endif
/*
* setns(2)
*
*/
#ifdef __linux__
#ifndef HAVE_SETNS
static int
setns(int fd, int nstype)
{
#ifdef __NR_setns
return syscall(__NR_setns, fd, nstype);
#else
errno = ENOSYS;
return -1;
#endif
}
#endif
#endif
ssize_t
alcove_sys_setns(alcove_state_t *ap, const char *arg, size_t len,
char *reply, size_t rlen)
{
#ifdef __linux__
int index = 0;
char path[PATH_MAX] = {0};
size_t plen = sizeof(path)-1;
int fd = -1;
int nstype = 0;
int rv = 0;
int errnum = 0;
/* path */
if (alcove_decode_iolist(arg, len, &index, path, &plen) < 0 ||
plen == 0)
return -1;
/* nstype */
switch (alcove_decode_define(arg, len, &index, &nstype,
alcove_clone_constants)) {
case 0:
break;
case 1:
return alcove_mk_error(reply, rlen, "unsupported");
default:
return -1;
}
fd = open(path, O_RDONLY);
if (fd < 0)
return alcove_mk_errno(reply, rlen, errno);
rv = setns(fd, nstype);
errnum = errno;
(void)close(fd);
if (rv < 0)
return alcove_mk_errno(reply, rlen, errnum);
return alcove_mk_atom(reply, rlen, "ok");
#else
return alcove_mk_atom(reply, rlen, "undef");
#endif
}