/*

   * Copyright (c) 2007-2014 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 DATAPATH_H
  #define DATAPATH_H 1
  
  #include <asm/page.h>
  #include <linux/kernel.h>
  #include <linux/mutex.h>
  #include <linux/netdevice.h>
  #include <linux/skbuff.h>
  #include <linux/u64_stats_sync.h>

  #include <net/ip_tunnels.h>

  #include "conntrack.h"

  #include "flow.h"

  #include "flow_table.h"

  #define DP_MAX_PORTS           USHRT_MAX
  #define DP_VPORT_HASH_BUCKETS  1024

  #define SAMPLE_ACTION_DEPTH 3
  
  /**
   * struct dp_stats_percpu - per-cpu packet processing statistics for a given
   * datapath.
   * @n_hit: Number of received packets for which a matching flow was found in
   * the flow table.
   * @n_miss: Number of received packets that had no matching flow in the flow
   * table.  The sum of @n_hit and @n_miss is the number of packets that have
   * been received by the datapath.
   * @n_lost: Number of received packets that had no matching flow in the flow
   * table that could not be sent to userspace (normally due to an overflow in
   * one of the datapath's queues).

   * @n_mask_hit: Number of masks looked up for flow match.
   *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
   *   up per packet.

   */
  struct dp_stats_percpu {
  	u64 n_hit;
  	u64 n_missed;
  	u64 n_lost;

  	u64 n_mask_hit;

  	struct u64_stats_sync syncp;

  };
  
  /**
   * struct datapath - datapath for flow-based packet switching
   * @rcu: RCU callback head for deferred destruction.
   * @list_node: Element in global 'dps' list.

   * @table: flow table.

   * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by

   * ovs_mutex and RCU.

   * @stats_percpu: Per-CPU datapath statistics.

   * @net: Reference to net namespace.

   * @max_headroom: the maximum headroom of all vports in this datapath; it will
   * be used by all the internal vports in this dp.

   *
   * Context: See the comment on locking at the top of datapath.c for additional
   * locking information.
   */
  struct datapath {
  	struct rcu_head rcu;
  	struct list_head list_node;
  
  	/* Flow table. */

  	struct flow_table table;

  
  	/* Switch ports. */

  	struct hlist_head *ports;

  
  	/* Stats. */
  	struct dp_stats_percpu __percpu *stats_percpu;

  	/* Network namespace ref. */

  	possible_net_t net;

  
  	u32 user_features;

  
  	u32 max_headroom;

  };
  
  /**
   * struct ovs_skb_cb - OVS data in skb CB

   * @input_vport: The original vport packet came in on. This value is cached
   * when a packet is received by OVS.

   * @mru: The maximum received fragement size; 0 if the packet is not

   * @cutlen: The number of bytes from the packet end to be removed.

   * fragmented.

   */
  struct ovs_skb_cb {

  	struct vport		*input_vport;

  	u16			mru;

  	u32			cutlen;

  };
  #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
  
  /**
   * struct dp_upcall - metadata to include with a packet to send to userspace
   * @cmd: One of %OVS_PACKET_CMD_*.

   * @userdata: If nonnull, its variable-length value is passed to userspace as

   * %OVS_PACKET_ATTR_USERDATA.

   * @portid: Netlink portid to which packet should be sent.  If @portid is 0
   * then no packet is sent and the packet is accounted in the datapath's @n_lost

   * counter.

   * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.

   * @mru: If not zero, Maximum received IP fragment size.

   */
  struct dp_upcall_info {

  	struct ip_tunnel_info *egress_tun_info;

  	const struct nlattr *userdata;

  	const struct nlattr *actions;
  	int actions_len;

  	u32 portid;

  	u8 cmd;

  	u16 mru;

  };

  /**
   * struct ovs_net - Per net-namespace data for ovs.
   * @dps: List of datapaths to enable dumping them all out.
   * Protected by genl_mutex.
   */
  struct ovs_net {
  	struct list_head dps;
  	struct work_struct dp_notify_work;

  
  	/* Module reference for configuring conntrack. */
  	bool xt_label;

  };
  
  extern int ovs_net_id;
  void ovs_lock(void);
  void ovs_unlock(void);
  
  #ifdef CONFIG_LOCKDEP
  int lockdep_ovsl_is_held(void);
  #else
  #define lockdep_ovsl_is_held()	1
  #endif

  #define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())

  #define ovsl_dereference(p)					\
  	rcu_dereference_protected(p, lockdep_ovsl_is_held())

  #define rcu_dereference_ovsl(p)					\
  	rcu_dereference_check(p, lockdep_ovsl_is_held())

  static inline struct net *ovs_dp_get_net(const struct datapath *dp)

  {
  	return read_pnet(&dp->net);
  }
  
  static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
  {
  	write_pnet(&dp->net, net);
  }

  struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
  
  static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
  {
  	WARN_ON_ONCE(!rcu_read_lock_held());
  	return ovs_lookup_vport(dp, port_no);
  }
  
  static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
  {
  	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
  	return ovs_lookup_vport(dp, port_no);
  }
  
  static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
  {
  	ASSERT_OVSL();
  	return ovs_lookup_vport(dp, port_no);
  }

  extern struct notifier_block ovs_dp_device_notifier;

  extern struct genl_family dp_vport_genl_family;

  void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);

  void ovs_dp_detach_port(struct vport *);
  int ovs_dp_upcall(struct datapath *, struct sk_buff *,

  		  const struct sw_flow_key *, const struct dp_upcall_info *,
  		  uint32_t cutlen);

  const char *ovs_dp_name(const struct datapath *dp);

  struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
  					 u8 cmd);

  int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,

  			const struct sw_flow_actions *, struct sw_flow_key *);

  void ovs_dp_notify_wq(struct work_struct *work);

  int action_fifos_init(void);
  void action_fifos_exit(void);

  /* 'KEY' must not have any bits set outside of the 'MASK' */
  #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
  #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))

  #define OVS_NLERR(logging_allowed, fmt, ...)			\

  do {								\

  	if (logging_allowed && net_ratelimit())			\
  		pr_info("netlink: " fmt "
  ", ##__VA_ARGS__);	\

  } while (0)

  #endif /* datapath.h */