/*
   * Copyright (c) 2007-2012 Nicira, Inc.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of version 2 of the GNU General Public
   * License as published by the Free Software Foundation.
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   * 02110-1301, USA
   */
  
  #ifndef VPORT_H
  #define VPORT_H 1
  
  #include <linux/if_tunnel.h>
  #include <linux/list.h>
  #include <linux/netlink.h>
  #include <linux/openvswitch.h>
  #include <linux/skbuff.h>
  #include <linux/spinlock.h>
  #include <linux/u64_stats_sync.h>
  
  #include "datapath.h"
  
  struct vport;
  struct vport_parms;
  
  /* The following definitions are for users of the vport subsytem: */
  
  /* The following definitions are for users of the vport subsytem: */
  struct vport_net {
  	struct vport __rcu *gre_vport;
  };
  
  int ovs_vport_init(void);
  void ovs_vport_exit(void);
  
  struct vport *ovs_vport_add(const struct vport_parms *);
  void ovs_vport_del(struct vport *);
  
  struct vport *ovs_vport_locate(struct net *net, const char *name);
  
  void ovs_vport_get_stats(struct vport *, struct ovs_vport_stats *);
  
  int ovs_vport_set_options(struct vport *, struct nlattr *options);
  int ovs_vport_get_options(const struct vport *, struct sk_buff *);
  
  int ovs_vport_send(struct vport *, struct sk_buff *);
  
  /* The following definitions are for implementers of vport devices: */
  
  struct vport_err_stats {
  	u64 rx_dropped;
  	u64 rx_errors;
  	u64 tx_dropped;
  	u64 tx_errors;
  };
  
  /**
   * struct vport - one port within a datapath
   * @rcu: RCU callback head for deferred destruction.
   * @dp: Datapath to which this port belongs.
   * @upcall_portid: The Netlink port to use for packets received on this port that
   * miss the flow table.
   * @port_no: Index into @dp's @ports array.
   * @hash_node: Element in @dev_table hash table in vport.c.
   * @dp_hash_node: Element in @datapath->ports hash table in datapath.c.
   * @ops: Class structure.
   * @percpu_stats: Points to per-CPU statistics used and maintained by vport
   * @stats_lock: Protects @err_stats;
   * @err_stats: Points to error statistics used and maintained by vport
   */
  struct vport {
  	struct rcu_head rcu;
  	struct datapath	*dp;
  	u32 upcall_portid;
  	u16 port_no;
  
  	struct hlist_node hash_node;
  	struct hlist_node dp_hash_node;
  	const struct vport_ops *ops;
  
  	struct pcpu_sw_netstats __percpu *percpu_stats;
  
  	spinlock_t stats_lock;
  	struct vport_err_stats err_stats;
  };
  
  /**
   * struct vport_parms - parameters for creating a new vport
   *
   * @name: New vport's name.
   * @type: New vport's type.
   * @options: %OVS_VPORT_ATTR_OPTIONS attribute from Netlink message, %NULL if
   * none was supplied.
   * @dp: New vport's datapath.
   * @port_no: New vport's port number.
   */
  struct vport_parms {
  	const char *name;
  	enum ovs_vport_type type;
  	struct nlattr *options;
  
  	/* For ovs_vport_alloc(). */
  	struct datapath *dp;
  	u16 port_no;
  	u32 upcall_portid;
  };
  
  /**
   * struct vport_ops - definition of a type of virtual port
   *
   * @type: %OVS_VPORT_TYPE_* value for this type of virtual port.
   * @create: Create a new vport configured as specified.  On success returns
   * a new vport allocated with ovs_vport_alloc(), otherwise an ERR_PTR() value.
   * @destroy: Destroys a vport.  Must call vport_free() on the vport but not
   * before an RCU grace period has elapsed.
   * @set_options: Modify the configuration of an existing vport.  May be %NULL
   * if modification is not supported.
   * @get_options: Appends vport-specific attributes for the configuration of an
   * existing vport to a &struct sk_buff.  May be %NULL for a vport that does not
   * have any configuration.
   * @get_name: Get the device's name.
   * @send: Send a packet on the device.  Returns the length of the packet sent,
   * zero for dropped packets or negative for error.
   */
  struct vport_ops {
  	enum ovs_vport_type type;
  
  	/* Called with ovs_mutex. */
  	struct vport *(*create)(const struct vport_parms *);
  	void (*destroy)(struct vport *);
  
  	int (*set_options)(struct vport *, struct nlattr *);
  	int (*get_options)(const struct vport *, struct sk_buff *);
  
  	/* Called with rcu_read_lock or ovs_mutex. */
  	const char *(*get_name)(const struct vport *);
  
  	int (*send)(struct vport *, struct sk_buff *);
  };
  
  enum vport_err_type {
  	VPORT_E_RX_DROPPED,
  	VPORT_E_RX_ERROR,
  	VPORT_E_TX_DROPPED,
  	VPORT_E_TX_ERROR,
  };
  
  struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *,
  			      const struct vport_parms *);
  void ovs_vport_free(struct vport *);
  void ovs_vport_deferred_free(struct vport *vport);
  
  #define VPORT_ALIGN 8
  
  /**
   *	vport_priv - access private data area of vport
   *
   * @vport: vport to access
   *
   * If a nonzero size was passed in priv_size of vport_alloc() a private data
   * area was allocated on creation.  This allows that area to be accessed and
   * used for any purpose needed by the vport implementer.
   */
  static inline void *vport_priv(const struct vport *vport)
  {
  	return (u8 *)vport + ALIGN(sizeof(struct vport), VPORT_ALIGN);
  }
  
  /**
   *	vport_from_priv - lookup vport from private data pointer
   *
   * @priv: Start of private data area.
   *
   * It is sometimes useful to translate from a pointer to the private data
   * area to the vport, such as in the case where the private data pointer is
   * the result of a hash table lookup.  @priv must point to the start of the
   * private data area.
   */
  static inline struct vport *vport_from_priv(const void *priv)
  {
  	return (struct vport *)(priv - ALIGN(sizeof(struct vport), VPORT_ALIGN));
  }
  
  void ovs_vport_receive(struct vport *, struct sk_buff *,
  		       struct ovs_key_ipv4_tunnel *);
  
  /* List of statically compiled vport implementations.  Don't forget to also
   * add yours to the list at the top of vport.c. */
  extern const struct vport_ops ovs_netdev_vport_ops;
  extern const struct vport_ops ovs_internal_vport_ops;
  extern const struct vport_ops ovs_gre_vport_ops;
  extern const struct vport_ops ovs_vxlan_vport_ops;
  
  static inline void ovs_skb_postpush_rcsum(struct sk_buff *skb,
  				      const void *start, unsigned int len)
  {
  	if (skb->ip_summed == CHECKSUM_COMPLETE)
  		skb->csum = csum_add(skb->csum, csum_partial(start, len, 0));
  }
  
  #endif /* vport.h */