core-admin/u2mfn/u2mfnlib.c
2012-11-14 13:31:47 +01:00

92 lines
2.0 KiB
C

/*
* The Qubes OS Project, http://www.qubes-os.org
*
* Copyright (C) 2010 Rafal Wojtczuk <rafal@invisiblethingslab.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <errno.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <stdlib.h>
#include "u2mfn-kernel.h"
static int u2mfn_fd = -1;
int u2mfn_get_fd()
{
return open("/proc/u2mfn", O_RDWR);
}
static int get_fd()
{
if (u2mfn_fd == -1)
u2mfn_fd = u2mfn_get_fd();
if (u2mfn_fd < 0)
return -1;
return 0;
}
int u2mfn_get_mfn_for_page_with_fd(int fd, long va, int *mfn)
{
*mfn = ioctl(fd, U2MFN_GET_MFN_FOR_PAGE, va);
if (*mfn == -1)
return -1;
return 0;
}
int u2mfn_get_mfn_for_page(long va, int *mfn)
{
if (get_fd())
return -1;
return u2mfn_get_mfn_for_page_with_fd(u2mfn_fd, va, mfn);
}
int u2mfn_get_last_mfn_with_fd(int fd, int *mfn)
{
*mfn = ioctl(fd, U2MFN_GET_LAST_MFN, 0);
if (*mfn == -1)
return -1;
return 0;
}
int u2mfn_get_last_mfn(int *mfn)
{
if (get_fd())
return -1;
return u2mfn_get_last_mfn_with_fd(u2mfn_fd, mfn);
}
char *u2mfn_alloc_kpage_with_fd(int fd)
{
char *ret;
ret =
mmap(0, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
return ret;
}
char *u2mfn_alloc_kpage()
{
if (get_fd())
return MAP_FAILED;
return u2mfn_alloc_kpage_with_fd(u2mfn_fd);
}