include/linux/if_tap.h

   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_*/