/*
   * VMware vSockets Driver
   *
   * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the Free
   * Software Foundation version 2 and no later version.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   */
  
  #ifndef __AF_VSOCK_H__
  #define __AF_VSOCK_H__
  
  #include <linux/kernel.h>
  #include <linux/workqueue.h>
  #include <linux/vm_sockets.h>
  
  #include "vsock_addr.h"

  /* vsock-specific sock->sk_state constants */
  #define VSOCK_SS_LISTEN 255

  #define LAST_RESERVED_PORT 1023
  
  #define vsock_sk(__sk)    ((struct vsock_sock *)__sk)
  #define sk_vsock(__vsk)   (&(__vsk)->sk)
  
  struct vsock_sock {
  	/* sk must be the first member. */
  	struct sock sk;
  	struct sockaddr_vm local_addr;
  	struct sockaddr_vm remote_addr;
  	/* Links for the global tables of bound and connected sockets. */
  	struct list_head bound_table;
  	struct list_head connected_table;
  	/* Accessed without the socket lock held. This means it can never be
  	 * modified outsided of socket create or destruct.
  	 */
  	bool trusted;
  	bool cached_peer_allow_dgram;	/* Dgram communication allowed to
  					 * cached peer?
  					 */
  	u32 cached_peer;  /* Context ID of last dgram destination check. */
  	const struct cred *owner;
  	/* Rest are SOCK_STREAM only. */
  	long connect_timeout;
  	/* Listening socket that this came from. */
  	struct sock *listener;
  	/* Used for pending list and accept queue during connection handshake.
  	 * The listening socket is the head for both lists.  Sockets created
  	 * for connection requests are placed in the pending list until they
  	 * are connected, at which point they are put in the accept queue list
  	 * so they can be accepted in accept().  If accept() cannot accept the
  	 * connection, it is marked as rejected so the cleanup function knows
  	 * to clean up the socket.
  	 */
  	struct list_head pending_links;
  	struct list_head accept_queue;
  	bool rejected;

  	struct delayed_work connect_work;
  	struct delayed_work pending_work;

  	struct delayed_work close_work;
  	bool close_work_scheduled;

  	u32 peer_shutdown;
  	bool sent_request;
  	bool ignore_connecting_rst;
  
  	/* Private to transport. */
  	void *trans;
  };
  
  s64 vsock_stream_has_data(struct vsock_sock *vsk);
  s64 vsock_stream_has_space(struct vsock_sock *vsk);

  struct sock *__vsock_create(struct net *net,
  			    struct socket *sock,
  			    struct sock *parent,

  			    gfp_t priority, unsigned short type, int kern);

  
  /**** TRANSPORT ****/
  
  struct vsock_transport_recv_notify_data {
  	u64 data1; /* Transport-defined. */
  	u64 data2; /* Transport-defined. */
  	bool notify_on_block;
  };
  
  struct vsock_transport_send_notify_data {
  	u64 data1; /* Transport-defined. */
  	u64 data2; /* Transport-defined. */
  };
  
  struct vsock_transport {
  	/* Initialize/tear-down socket. */
  	int (*init)(struct vsock_sock *, struct vsock_sock *);
  	void (*destruct)(struct vsock_sock *);
  	void (*release)(struct vsock_sock *);

  	/* Cancel all pending packets sent on vsock. */
  	int (*cancel_pkt)(struct vsock_sock *vsk);

  	/* Connections. */
  	int (*connect)(struct vsock_sock *);
  
  	/* DGRAM. */
  	int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *);

  	int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
  			     size_t len, int flags);

  	int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,

  			     struct msghdr *, size_t len);

  	bool (*dgram_allow)(u32 cid, u32 port);
  
  	/* STREAM. */
  	/* TODO: stream_bind() */

  	ssize_t (*stream_dequeue)(struct vsock_sock *, struct msghdr *,

  				  size_t len, int flags);

  	ssize_t (*stream_enqueue)(struct vsock_sock *, struct msghdr *,

  				  size_t len);
  	s64 (*stream_has_data)(struct vsock_sock *);
  	s64 (*stream_has_space)(struct vsock_sock *);
  	u64 (*stream_rcvhiwat)(struct vsock_sock *);
  	bool (*stream_is_active)(struct vsock_sock *);
  	bool (*stream_allow)(u32 cid, u32 port);
  
  	/* Notification. */
  	int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);
  	int (*notify_poll_out)(struct vsock_sock *, size_t, bool *);
  	int (*notify_recv_init)(struct vsock_sock *, size_t,
  		struct vsock_transport_recv_notify_data *);
  	int (*notify_recv_pre_block)(struct vsock_sock *, size_t,
  		struct vsock_transport_recv_notify_data *);
  	int (*notify_recv_pre_dequeue)(struct vsock_sock *, size_t,
  		struct vsock_transport_recv_notify_data *);
  	int (*notify_recv_post_dequeue)(struct vsock_sock *, size_t,
  		ssize_t, bool, struct vsock_transport_recv_notify_data *);
  	int (*notify_send_init)(struct vsock_sock *,
  		struct vsock_transport_send_notify_data *);
  	int (*notify_send_pre_block)(struct vsock_sock *,
  		struct vsock_transport_send_notify_data *);
  	int (*notify_send_pre_enqueue)(struct vsock_sock *,
  		struct vsock_transport_send_notify_data *);
  	int (*notify_send_post_enqueue)(struct vsock_sock *, ssize_t,
  		struct vsock_transport_send_notify_data *);
  
  	/* Shutdown. */
  	int (*shutdown)(struct vsock_sock *, int);
  
  	/* Buffer sizes. */
  	void (*set_buffer_size)(struct vsock_sock *, u64);
  	void (*set_min_buffer_size)(struct vsock_sock *, u64);
  	void (*set_max_buffer_size)(struct vsock_sock *, u64);
  	u64 (*get_buffer_size)(struct vsock_sock *);
  	u64 (*get_min_buffer_size)(struct vsock_sock *);
  	u64 (*get_max_buffer_size)(struct vsock_sock *);
  
  	/* Addressing. */
  	u32 (*get_local_cid)(void);
  };
  
  /**** CORE ****/

  int __vsock_core_init(const struct vsock_transport *t, struct module *owner);
  static inline int vsock_core_init(const struct vsock_transport *t)
  {
  	return __vsock_core_init(t, THIS_MODULE);
  }

  void vsock_core_exit(void);

  /* The transport may downcast this to access transport-specific functions */
  const struct vsock_transport *vsock_core_get_transport(void);

  /**** UTILS ****/
  
  void vsock_release_pending(struct sock *pending);
  void vsock_add_pending(struct sock *listener, struct sock *pending);
  void vsock_remove_pending(struct sock *listener, struct sock *pending);
  void vsock_enqueue_accept(struct sock *listener, struct sock *connected);
  void vsock_insert_connected(struct vsock_sock *vsk);
  void vsock_remove_bound(struct vsock_sock *vsk);
  void vsock_remove_connected(struct vsock_sock *vsk);
  struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr);
  struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
  					 struct sockaddr_vm *dst);

  void vsock_remove_sock(struct vsock_sock *vsk);

  void vsock_for_each_connected_socket(void (*fn)(struct sock *sk));

  /**** TAP ****/
  
  struct vsock_tap {
  	struct net_device *dev;
  	struct module *module;
  	struct list_head list;
  };
  
  int vsock_init_tap(void);
  int vsock_add_tap(struct vsock_tap *vt);
  int vsock_remove_tap(struct vsock_tap *vt);
  void vsock_deliver_tap(struct sk_buff *build_skb(void *opaque), void *opaque);

  #endif /* __AF_VSOCK_H__ */