/*
* Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.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 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 St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <linux_api.h>
#include <ipxe/list.h>
#include <ipxe/linux.h>
#include <ipxe/malloc.h>
#include <ipxe/device.h>
#include <ipxe/netdevice.h>
#include <ipxe/iobuf.h>
#include <ipxe/ethernet.h>
#include <ipxe/settings.h>
#include <ipxe/socket.h>
/* This hack prevents pre-2.6.32 headers from redefining struct sockaddr */
#define _SYS_SOCKET_H
#define __GLIBC__ 2
#include <linux/socket.h>
#undef __GLIBC__
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_tun.h>
#define RX_BUF_SIZE 1536
#define RX_QUOTA 4
/** @file
*
* The TAP driver.
*
* The TAP is a Virtual Ethernet network device.
*/
struct tap_nic {
/** Tap interface name */
char * interface;
/** File descriptor of the opened tap device */
int fd;
};
/** Open the TAP device */
static int tap_open(struct net_device * netdev)
{
struct tap_nic * nic = netdev->priv;
struct ifreq ifr;
int ret;
nic->fd = linux_open("/dev/net/tun", O_RDWR);
if (nic->fd < 0) {
DBGC(nic, "tap %p open('/dev/net/tun') = %d (%s)\n", nic, nic->fd, linux_strerror(linux_errno));
return nic->fd;
}
memset(&ifr, 0, sizeof(ifr));
/* IFF_NO_PI for no extra packet information */
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
strncpy(ifr.ifr_name, nic->interface, IFNAMSIZ);
DBGC(nic, "tap %p interface = '%s'\n", nic, nic->interface);
ret = linux_ioctl(nic->fd, TUNSETIFF, &ifr);
if (ret != 0) {
DBGC(nic, "tap %p ioctl(%d, ...) = %d (%s)\n", nic, nic->fd, ret, linux_strerror(linux_errno));
linux_close(nic->fd);
return ret;
}
/* Set nonblocking mode to make tap_poll easier */
ret = linux_fcntl(nic->fd, F_SETFL, O_NONBLOCK);
if (ret != 0) {
DBGC(nic, "tap %p fcntl(%d, ...) = %d (%s)\n", nic, nic->fd, ret, linux_strerror(linux_errno));
linux_close(nic->fd);
return ret;
}
return 0;
}
/** Close the TAP device */
static void tap_close(struct net_device *netdev)
{
struct tap_nic * nic = netdev->priv;
linux_close(nic->fd);
}
/**
* Transmit an ethernet packet.
*
* The packet can be written to the TAP device and marked as complete immediately.
*/
static int tap_transmit(struct net_device *netdev, struct io_buffer *iobuf)
{
struct tap_nic * nic = netdev->priv;
int rc;
/* Pad and align packet */
iob_pad(iobuf, ETH_ZLEN);
rc = linux_write(nic->fd, iobuf->data, iobuf->tail - iobuf->data);
DBGC2(nic, "tap %p wrote %d bytes\n", nic, rc);
netdev_tx_complete(netdev, iobuf);
return 0;
}
/** Poll for new packets */
static void tap_poll(struct net_device *netdev)
{
struct tap_nic * nic = netdev->priv;
struct pollfd pfd;
struct io_buffer * iobuf;
unsigned int quota = RX_QUOTA;
int r;
pfd.fd = nic->fd;
pfd.events = POLLIN;
if (linux_poll(&pfd, 1, 0) == -1) {
DBGC(nic, "tap %p poll failed (%s)\n", nic, linux_strerror(linux_errno));
return;
}
if ((pfd.revents & POLLIN) == 0)
return;
/* At this point we know there is at least one new packet to be read */
iobuf = alloc_iob(RX_BUF_SIZE);
if (! iobuf)
goto allocfail;
while (quota-- &&
((r = linux_read(nic->fd, iobuf->data, RX_BUF_SIZE)) > 0)) {
DBGC2(nic, "tap %p read %d bytes\n", nic, r);
iob_put(iobuf, r);
netdev_rx(netdev, iobuf);
iobuf = alloc_iob(RX_BUF_SIZE);
if (! iobuf)
goto allocfail;
}
free_iob(iobuf);
return;
allocfail:
DBGC(nic, "tap %p alloc_iob failed\n", nic);
}
/**
* Set irq.
*
* Not used on linux, provide a dummy implementation.
*/
static void tap_irq(struct net_device *netdev, int enable)
{
struct tap_nic *nic = netdev->priv;
DBGC(nic, "tap %p irq enable = %d\n", nic, enable);
}
/** Tap operations */
static struct net_device_operations tap_operations = {
.open = tap_open,
.close = tap_close,
.transmit = tap_transmit,
.poll = tap_poll,
.irq = tap_irq,
};
/** Handle a device request for the tap driver */
static int tap_probe(struct linux_device *device, struct linux_device_request *request)
{
struct linux_setting *if_setting;
struct net_device *netdev;
struct tap_nic *nic;
int rc;
netdev = alloc_etherdev(sizeof(*nic));
if (! netdev)
return -ENOMEM;
netdev_init(netdev, &tap_operations);
nic = netdev->priv;
linux_set_drvdata(device, netdev);
netdev->dev = &device->dev;
memset(nic, 0, sizeof(*nic));
/* Look for the mandatory if setting */
if_setting = linux_find_setting("if", &request->settings);
/* No if setting */
if (! if_setting) {
printf("tap missing a mandatory if setting\n");
rc = -EINVAL;
goto err_settings;
}
nic->interface = if_setting->value;
snprintf ( device->dev.name, sizeof ( device->dev.name ), "%s",
nic->interface );
device->dev.desc.bus_type = BUS_TYPE_TAP;
if_setting->applied = 1;
/* Apply rest of the settings */
linux_apply_settings(&request->settings, &netdev->settings.settings);
/* Register network device */
if ((rc = register_netdev(netdev)) != 0)
goto err_register;
netdev_link_up(netdev);
return 0;
err_settings:
unregister_netdev(netdev);
err_register:
netdev_nullify(netdev);
netdev_put(netdev);
return rc;
}
/** Remove the device */
static void tap_remove(struct linux_device *device)
{
struct net_device *netdev = linux_get_drvdata(device);
unregister_netdev(netdev);
netdev_nullify(netdev);
netdev_put(netdev);
}
/** Tap linux_driver */
struct linux_driver tap_driver __linux_driver = {
.name = "tap",
.probe = tap_probe,
.remove = tap_remove,
.can_probe = 1,
};
