1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef _LINUX_IF_TAP_H_
 3#define _LINUX_IF_TAP_H_
 4
 5#if IS_ENABLED(CONFIG_TAP)
 6struct socket *tap_get_socket(struct file *);
 7struct ptr_ring *tap_get_ptr_ring(struct file *file);
 8#else
 9#include <linux/err.h>
10#include <linux/errno.h>
11struct file;
12struct socket;
13static inline struct socket *tap_get_socket(struct file *f)
14{
15	return ERR_PTR(-EINVAL);
16}
17static inline struct ptr_ring *tap_get_ptr_ring(struct file *f)
18{
19	return ERR_PTR(-EINVAL);
20}
21#endif /* CONFIG_TAP */
22
23#include <net/sock.h>
24#include <linux/skb_array.h>
25
26/*
27 * Maximum times a tap device can be opened. This can be used to
28 * configure the number of receive queue, e.g. for multiqueue virtio.
29 */
30#define MAX_TAP_QUEUES 256
31
32struct tap_queue;
33
34struct tap_dev {
35	struct net_device	*dev;
36	u16			flags;
37	/* This array tracks active taps. */
38	struct tap_queue    __rcu *taps[MAX_TAP_QUEUES];
39	/* This list tracks all taps (both enabled and disabled) */
40	struct list_head	queue_list;
41	int			numvtaps;
42	int			numqueues;
43	netdev_features_t	tap_features;
44	int			minor;
45
46	void (*update_features)(struct tap_dev *tap, netdev_features_t features);
47	void (*count_tx_dropped)(struct tap_dev *tap);
48	void (*count_rx_dropped)(struct tap_dev *tap);
49};
50
51/*
52 * A tap queue is the central object of tap module, it connects
53 * an open character device to virtual interface. There can be
54 * multiple queues on one interface, which map back to queues
55 * implemented in hardware on the underlying device.
56 *
57 * tap_proto is used to allocate queues through the sock allocation
58 * mechanism.
59 *
60 */
61
62struct tap_queue {
63	struct sock sk;
64	struct socket sock;
65	int vnet_hdr_sz;
66	struct tap_dev __rcu *tap;
67	struct file *file;
68	unsigned int flags;
69	u16 queue_index;
70	bool enabled;
71	struct list_head next;
72	struct ptr_ring ring;
73};
74
75rx_handler_result_t tap_handle_frame(struct sk_buff **pskb);
76void tap_del_queues(struct tap_dev *tap);
77int tap_get_minor(dev_t major, struct tap_dev *tap);
78void tap_free_minor(dev_t major, struct tap_dev *tap);
79int tap_queue_resize(struct tap_dev *tap);
80int tap_create_cdev(struct cdev *tap_cdev, dev_t *tap_major,
81		    const char *device_name, struct module *module);
82void tap_destroy_cdev(dev_t major, struct cdev *tap_cdev);
83
84#endif /*_LINUX_IF_TAP_H_*/