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

  #ifndef _LINUX_VIRTIO_VSOCK_H
  #define _LINUX_VIRTIO_VSOCK_H
  
  #include <uapi/linux/virtio_vsock.h>
  #include <linux/socket.h>
  #include <net/sock.h>
  #include <net/af_vsock.h>

  #define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE	(1024 * 4)
  #define VIRTIO_VSOCK_MAX_BUF_SIZE		0xFFFFFFFFUL
  #define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE		(1024 * 64)
  
  enum {
  	VSOCK_VQ_RX     = 0, /* for host to guest data */
  	VSOCK_VQ_TX     = 1, /* for guest to host data */
  	VSOCK_VQ_EVENT  = 2,
  	VSOCK_VQ_MAX    = 3,
  };
  
  /* Per-socket state (accessed via vsk->trans) */
  struct virtio_vsock_sock {
  	struct vsock_sock *vsk;

  	spinlock_t tx_lock;
  	spinlock_t rx_lock;
  
  	/* Protected by tx_lock */
  	u32 tx_cnt;

  	u32 peer_fwd_cnt;
  	u32 peer_buf_alloc;
  
  	/* Protected by rx_lock */
  	u32 fwd_cnt;

  	u32 last_fwd_cnt;

  	u32 rx_bytes;

  	u32 buf_alloc;

  	struct list_head rx_queue;
  };
  
  struct virtio_vsock_pkt {
  	struct virtio_vsock_hdr	hdr;

  	struct list_head list;

  	/* socket refcnt not held, only use for cancellation */
  	struct vsock_sock *vsk;

  	void *buf;

  	u32 buf_len;

  	u32 len;
  	u32 off;
  	bool reply;

  	bool tap_delivered;

  };
  
  struct virtio_vsock_pkt_info {
  	u32 remote_cid, remote_port;

  	struct vsock_sock *vsk;

  	struct msghdr *msg;
  	u32 pkt_len;
  	u16 type;
  	u16 op;
  	u32 flags;
  	bool reply;
  };
  
  struct virtio_transport {
  	/* This must be the first field */
  	struct vsock_transport transport;
  
  	/* Takes ownership of the packet */
  	int (*send_pkt)(struct virtio_vsock_pkt *pkt);
  };
  
  ssize_t
  virtio_transport_stream_dequeue(struct vsock_sock *vsk,
  				struct msghdr *msg,
  				size_t len,
  				int type);
  int
  virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
  			       struct msghdr *msg,
  			       size_t len, int flags);
  
  s64 virtio_transport_stream_has_data(struct vsock_sock *vsk);
  s64 virtio_transport_stream_has_space(struct vsock_sock *vsk);
  
  int virtio_transport_do_socket_init(struct vsock_sock *vsk,
  				 struct vsock_sock *psk);

  int
  virtio_transport_notify_poll_in(struct vsock_sock *vsk,
  				size_t target,
  				bool *data_ready_now);
  int
  virtio_transport_notify_poll_out(struct vsock_sock *vsk,
  				 size_t target,
  				 bool *space_available_now);
  
  int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
  	size_t target, struct vsock_transport_recv_notify_data *data);
  int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
  	size_t target, struct vsock_transport_recv_notify_data *data);
  int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
  	size_t target, struct vsock_transport_recv_notify_data *data);
  int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
  	size_t target, ssize_t copied, bool data_read,
  	struct vsock_transport_recv_notify_data *data);
  int virtio_transport_notify_send_init(struct vsock_sock *vsk,
  	struct vsock_transport_send_notify_data *data);
  int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
  	struct vsock_transport_send_notify_data *data);
  int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
  	struct vsock_transport_send_notify_data *data);
  int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
  	ssize_t written, struct vsock_transport_send_notify_data *data);

  void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val);

  
  u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk);
  bool virtio_transport_stream_is_active(struct vsock_sock *vsk);
  bool virtio_transport_stream_allow(u32 cid, u32 port);
  int virtio_transport_dgram_bind(struct vsock_sock *vsk,
  				struct sockaddr_vm *addr);
  bool virtio_transport_dgram_allow(u32 cid, u32 port);
  
  int virtio_transport_connect(struct vsock_sock *vsk);
  
  int virtio_transport_shutdown(struct vsock_sock *vsk, int mode);
  
  void virtio_transport_release(struct vsock_sock *vsk);
  
  ssize_t
  virtio_transport_stream_enqueue(struct vsock_sock *vsk,
  				struct msghdr *msg,
  				size_t len);
  int
  virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
  			       struct sockaddr_vm *remote_addr,
  			       struct msghdr *msg,
  			       size_t len);
  
  void virtio_transport_destruct(struct vsock_sock *vsk);

  void virtio_transport_recv_pkt(struct virtio_transport *t,
  			       struct virtio_vsock_pkt *pkt);

  void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt);
  void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt);
  u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 wanted);
  void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit);

  void virtio_transport_deliver_tap_pkt(struct virtio_vsock_pkt *pkt);

  
  #endif /* _LINUX_VIRTIO_VSOCK_H */