path: root/drivers/net/tap.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/etherdevice.h>
#include <linux/if_tap.h>
#include <linux/if_vlan.h>
#include <linux/interrupt.h>
#include <linux/nsproxy.h>
#include <linux/compat.h>
#include <linux/if_tun.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/cache.h>
#include <linux/sched/signal.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/cdev.h>
#include <linux/idr.h>
#include <linux/fs.h>
#include <linux/uio.h>

#include <net/net_namespace.h>
#include <net/rtnetlink.h>
#include <net/sock.h>
#include <linux/virtio_net.h>
#include <linux/skb_array.h>

#define TAP_IFFEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE)

#define TAP_VNET_LE 0x80000000
#define TAP_VNET_BE 0x40000000

#ifdef CONFIG_TUN_VNET_CROSS_LE
static inline bool tap_legacy_is_little_endian(struct tap_queue *q)
{
	return q->flags & TAP_VNET_BE ? false :
		virtio_legacy_is_little_endian();
}

static long tap_get_vnet_be(struct tap_queue *q, int __user *sp)
{
	int s = !!(q->flags & TAP_VNET_BE);

	if (put_user(s, sp))
		return -EFAULT;

	return 0;
}

static long tap_set_vnet_be(struct tap_queue *q, int __user *sp)
{
	int s;

	if (get_user(s, sp))
		return -EFAULT;

	if (s)
		q->flags |= TAP_VNET_BE;
	else
		q->flags &= ~TAP_VNET_BE;

	return 0;
}
#else
static inline bool tap_legacy_is_little_endian(struct tap_queue *q)
{
	return virtio_legacy_is_little_endian();
}

static long tap_get_vnet_be(struct tap_queue *q, int __user *argp)
{
	return -EINVAL;
}

static long tap_set_vnet_be(struct tap_queue *q, int __user *argp)
{
	return -EINVAL;
}
#endif /* CONFIG_TUN_VNET_CROSS_LE */

static inline bool tap_is_little_endian(struct tap_queue *q)
{
	return q->flags & TAP_VNET_LE ||
		tap_legacy_is_little_endian(q);