/* SPDX-License-Identifier: GPL-2.0-or-later */

  /*
   *  Universal TUN/TAP device driver.
   *  Copyright (C) 1999-2000 Maxim Krasnyansky <max_mk@yahoo.com>

   */

  #ifndef __IF_TUN_H
  #define __IF_TUN_H

  #include <uapi/linux/if_tun.h>

  #include <uapi/linux/virtio_net.h>

  #define TUN_XDP_FLAG 0x1UL

  #define TUN_MSG_UBUF 1
  #define TUN_MSG_PTR  2
  struct tun_msg_ctl {
  	unsigned short type;
  	unsigned short num;
  	void *ptr;
  };
  
  struct tun_xdp_hdr {
  	int buflen;
  	struct virtio_net_hdr gso;
  };

  #if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE)
  struct socket *tun_get_socket(struct file *);

  struct ptr_ring *tun_get_tx_ring(struct file *file);

  static inline bool tun_is_xdp_frame(void *ptr)
  {
         return (unsigned long)ptr & TUN_XDP_FLAG;
  }
  static inline void *tun_xdp_to_ptr(struct xdp_frame *xdp)
  {
         return (void *)((unsigned long)xdp | TUN_XDP_FLAG);
  }
  static inline struct xdp_frame *tun_ptr_to_xdp(void *ptr)
  {
         return (void *)((unsigned long)ptr & ~TUN_XDP_FLAG);
  }

  void tun_ptr_free(void *ptr);

  #else
  #include <linux/err.h>
  #include <linux/errno.h>
  struct file;
  struct socket;
  static inline struct socket *tun_get_socket(struct file *f)
  {
  	return ERR_PTR(-EINVAL);
  }

  static inline struct ptr_ring *tun_get_tx_ring(struct file *f)

  {
  	return ERR_PTR(-EINVAL);
  }

  static inline bool tun_is_xdp_frame(void *ptr)

  {
  	return false;
  }

  static inline void *tun_xdp_to_ptr(struct xdp_frame *xdp)

  {
  	return NULL;
  }

  static inline struct xdp_frame *tun_ptr_to_xdp(void *ptr)

  {
  	return NULL;
  }

  static inline void tun_ptr_free(void *ptr)
  {
  }

  #endif /* CONFIG_TUN */

  #endif /* __IF_TUN_H */