1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_IF_TAP_H_
3 #define _LINUX_IF_TAP_H_
4
5 #include <net/sock.h>
6 #include <linux/skb_array.h>
7
8 struct file;
9 struct socket;
10
11 #if IS_ENABLED(CONFIG_TAP)
12 struct socket *tap_get_socket(struct file *);
13 struct ptr_ring *tap_get_ptr_ring(struct file *file);
14 #else
15 #include <linux/err.h>
16 #include <linux/errno.h>
17 static inline struct socket *tap_get_socket(struct file *f)
18 {
19 return ERR_PTR(-EINVAL);
20 }
21 static inline struct ptr_ring *tap_get_ptr_ring(struct file *f)
22 {
23 return ERR_PTR(-EINVAL);
24 }
25 #endif /* CONFIG_TAP */
26
27 /*
28 * Maximum times a tap device can be opened. This can be used to
29 * configure the number of receive queue, e.g. for multiqueue virtio.
30 */
31 #define MAX_TAP_QUEUES 256
32
33 struct tap_queue;
34
35 struct tap_dev {
36 struct net_device *dev;
37 u16 flags;
38 /* This array tracks active taps. */
39 struct tap_queue __rcu *taps[MAX_TAP_QUEUES];
40 /* This list tracks all taps (both enabled and disabled) */
41 struct list_head queue_list;
42 int numvtaps;
43 int numqueues;
44 netdev_features_t tap_features;
45 int minor;
46
47 void (*update_features)(struct tap_dev *tap, netdev_features_t features);
48 void (*count_tx_dropped)(struct tap_dev *tap);
49 void (*count_rx_dropped)(struct tap_dev *tap);
50 };
51
52 /*
53 * A tap queue is the central object of tap module, it connects
54 * an open character device to virtual interface. There can be
55 * multiple queues on one interface, which map back to queues
56 * implemented in hardware on the underlying device.
57 *
58 * tap_proto is used to allocate queues through the sock allocation
59 * mechanism.
60 *
61 */
62
63 struct tap_queue {
64 struct sock sk;
65 struct socket sock;
66 int vnet_hdr_sz;
67 struct tap_dev __rcu *tap;
68 struct file *file;
69 unsigned int flags;
70 u16 queue_index;
71 bool enabled;
72 struct list_head next;
73 struct ptr_ring ring;
74 };
75
76 rx_handler_result_t tap_handle_frame(struct sk_buff **pskb);
77 void tap_del_queues(struct tap_dev *tap);
78 int tap_get_minor(dev_t major, struct tap_dev *tap);
79 void tap_free_minor(dev_t major, struct tap_dev *tap);
80 int tap_queue_resize(struct tap_dev *tap);
81 int tap_create_cdev(struct cdev *tap_cdev, dev_t *tap_major,
82 const char *device_name, struct module *module);
83 void tap_destroy_cdev(dev_t major, struct cdev *tap_cdev);
84
85 #endif /*_LINUX_IF_TAP_H_*/
86
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