/*

   * Copyright (c) 2007-2017 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 FLOW_H
  #define FLOW_H 1

  #include <linux/cache.h>

  #include <linux/kernel.h>
  #include <linux/netlink.h>
  #include <linux/openvswitch.h>
  #include <linux/spinlock.h>
  #include <linux/types.h>
  #include <linux/rcupdate.h>
  #include <linux/if_ether.h>
  #include <linux/in6.h>
  #include <linux/jiffies.h>
  #include <linux/time.h>
  #include <linux/flex_array.h>

  #include <linux/cpumask.h>

  #include <net/inet_ecn.h>

  #include <net/ip_tunnels.h>

  #include <net/dst_metadata.h>

  
  struct sk_buff;

  enum sw_flow_mac_proto {
  	MAC_PROTO_NONE = 0,
  	MAC_PROTO_ETHERNET,
  };
  #define SW_FLOW_KEY_INVALID	0x80

  /* Store options at the end of the array if they are less than the
   * maximum size. This allows us to get the benefits of variable length
   * matching for small options.
   */

  #define TUN_METADATA_OFFSET(opt_len) \
  	(FIELD_SIZEOF(struct sw_flow_key, tun_opts) - opt_len)
  #define TUN_METADATA_OPTS(flow_key, opt_len) \
  	((void *)((flow_key)->tun_opts + TUN_METADATA_OFFSET(opt_len)))

  struct ovs_tunnel_info {
  	struct metadata_dst	*tun_dst;
  };

  struct vlan_head {
  	__be16 tpid; /* Vlan type. Generally 802.1q or 802.1ad.*/
  	__be16 tci;  /* 0 if no VLAN, VLAN_TAG_PRESENT set otherwise. */
  };

  #define OVS_SW_FLOW_KEY_METADATA_SIZE			\
  	(offsetof(struct sw_flow_key, recirc_id) +	\
  	FIELD_SIZEOF(struct sw_flow_key, recirc_id))

  struct sw_flow_key {

  	u8 tun_opts[IP_TUNNEL_OPTS_MAX];

  	u8 tun_opts_len;

  	struct ip_tunnel_key tun_key;	/* Encapsulating tunnel key. */

  	struct {
  		u32	priority;	/* Packet QoS priority. */

  		u32	skb_mark;	/* SKB mark. */

  		u16	in_port;	/* Input switch port (or DP_MAX_PORTS). */

  	} __packed phy; /* Safe when right after 'tun_key'. */

  	u8 mac_proto;			/* MAC layer protocol (e.g. Ethernet). */

  	u8 tun_proto;			/* Protocol of encapsulating tunnel. */

  	u32 ovs_flow_hash;		/* Datapath computed hash value.  */
  	u32 recirc_id;			/* Recirculation ID.  */

  	struct {
  		u8     src[ETH_ALEN];	/* Ethernet source address. */
  		u8     dst[ETH_ALEN];	/* Ethernet destination address. */

  		struct vlan_head vlan;
  		struct vlan_head cvlan;

  		__be16 type;		/* Ethernet frame type. */
  	} eth;

  	/* Filling a hole of two bytes. */
  	u8 ct_state;
  	u8 ct_orig_proto;		/* CT original direction tuple IP
  					 * protocol.
  					 */

  	union {
  		struct {
  			__be32 top_lse;	/* top label stack entry */
  		} mpls;
  		struct {
  			u8     proto;	/* IP protocol or lower 8 bits of ARP opcode. */
  			u8     tos;	    /* IP ToS. */
  			u8     ttl;	    /* IP TTL/hop limit. */
  			u8     frag;	/* One of OVS_FRAG_TYPE_*. */
  		} ip;
  	};

  	u16 ct_zone;			/* Conntrack zone. */

  	struct {
  		__be16 src;		/* TCP/UDP/SCTP source port. */
  		__be16 dst;		/* TCP/UDP/SCTP destination port. */
  		__be16 flags;		/* TCP flags. */
  	} tp;

  	union {
  		struct {
  			struct {
  				__be32 src;	/* IP source address. */
  				__be32 dst;	/* IP destination address. */
  			} addr;

  			union {
  				struct {
  					__be32 src;
  					__be32 dst;
  				} ct_orig;	/* Conntrack original direction fields. */
  				struct {
  					u8 sha[ETH_ALEN];	/* ARP source hardware address. */
  					u8 tha[ETH_ALEN];	/* ARP target hardware address. */
  				} arp;
  			};

  		} ipv4;
  		struct {
  			struct {
  				struct in6_addr src;	/* IPv6 source address. */
  				struct in6_addr dst;	/* IPv6 destination address. */
  			} addr;
  			__be32 label;			/* IPv6 flow label. */

  			union {
  				struct {
  					struct in6_addr src;
  					struct in6_addr dst;
  				} ct_orig;	/* Conntrack original direction fields. */
  				struct {
  					struct in6_addr target;	/* ND target address. */
  					u8 sll[ETH_ALEN];	/* ND source link layer address. */
  					u8 tll[ETH_ALEN];	/* ND target link layer address. */
  				} nd;
  			};

  		} ipv6;
  	};

  	struct {

  		/* Connection tracking fields not packed above. */

  		struct {
  			__be16 src;	/* CT orig tuple tp src port. */
  			__be16 dst;	/* CT orig tuple tp dst port. */
  		} orig_tp;

  		u32 mark;

  		struct ovs_key_ct_labels labels;

  	} ct;

  } __aligned(BITS_PER_LONG/8); /* Ensure that we can do comparisons as longs. */

  static inline bool sw_flow_key_is_nd(const struct sw_flow_key *key)
  {
  	return key->eth.type == htons(ETH_P_IPV6) &&
  		key->ip.proto == NEXTHDR_ICMP &&
  		key->tp.dst == 0 &&
  		(key->tp.src == htons(NDISC_NEIGHBOUR_SOLICITATION) ||
  		 key->tp.src == htons(NDISC_NEIGHBOUR_ADVERTISEMENT));
  }

  struct sw_flow_key_range {

  	unsigned short int start;
  	unsigned short int end;

  };
  
  struct sw_flow_mask {
  	int ref_count;
  	struct rcu_head rcu;
  	struct list_head list;
  	struct sw_flow_key_range range;
  	struct sw_flow_key key;
  };
  
  struct sw_flow_match {
  	struct sw_flow_key *key;
  	struct sw_flow_key_range range;
  	struct sw_flow_mask *mask;
  };

  #define MAX_UFID_LENGTH 16 /* 128 bits */
  
  struct sw_flow_id {
  	u32 ufid_len;
  	union {
  		u32 ufid[MAX_UFID_LENGTH / 4];
  		struct sw_flow_key *unmasked_key;
  	};
  };

  struct sw_flow_actions {
  	struct rcu_head rcu;

  	size_t orig_len;	/* From flow_cmd_new netlink actions size */

  	u32 actions_len;
  	struct nlattr actions[];
  };

  struct flow_stats {
  	u64 packet_count;		/* Number of packets matched. */
  	u64 byte_count;			/* Number of bytes matched. */
  	unsigned long used;		/* Last used time (in jiffies). */
  	spinlock_t lock;		/* Lock for atomic stats update. */
  	__be16 tcp_flags;		/* Union of seen TCP flags. */
  };

  struct sw_flow {
  	struct rcu_head rcu;

  	struct {
  		struct hlist_node node[2];
  		u32 hash;
  	} flow_table, ufid_table;

  	int stats_last_writer;		/* CPU id of the last writer on

  					 * 'stats[0]'.
  					 */

  	struct sw_flow_key key;

  	struct sw_flow_id id;

  	struct cpumask cpu_used_mask;

  	struct sw_flow_mask *mask;

  	struct sw_flow_actions __rcu *sf_acts;

  	struct flow_stats __rcu *stats[]; /* One for each CPU.  First one

  					   * is allocated at flow creation time,
  					   * the rest are allocated on demand
  					   * while holding the 'stats[0].lock'.
  					   */

  };
  
  struct arp_eth_header {
  	__be16      ar_hrd;	/* format of hardware address   */
  	__be16      ar_pro;	/* format of protocol address   */
  	unsigned char   ar_hln;	/* length of hardware address   */
  	unsigned char   ar_pln;	/* length of protocol address   */
  	__be16      ar_op;	/* ARP opcode (command)     */
  
  	/* Ethernet+IPv4 specific members. */
  	unsigned char       ar_sha[ETH_ALEN];	/* sender hardware address  */
  	unsigned char       ar_sip[4];		/* sender IP address        */
  	unsigned char       ar_tha[ETH_ALEN];	/* target hardware address  */
  	unsigned char       ar_tip[4];		/* target IP address        */
  } __packed;

  static inline u8 ovs_key_mac_proto(const struct sw_flow_key *key)
  {
  	return key->mac_proto & ~SW_FLOW_KEY_INVALID;
  }
  
  static inline u16 __ovs_mac_header_len(u8 mac_proto)
  {
  	return mac_proto == MAC_PROTO_ETHERNET ? ETH_HLEN : 0;
  }
  
  static inline u16 ovs_mac_header_len(const struct sw_flow_key *key)
  {
  	return __ovs_mac_header_len(ovs_key_mac_proto(key));
  }

  static inline bool ovs_identifier_is_ufid(const struct sw_flow_id *sfid)
  {
  	return sfid->ufid_len;
  }
  
  static inline bool ovs_identifier_is_key(const struct sw_flow_id *sfid)
  {
  	return !ovs_identifier_is_ufid(sfid);
  }

  void ovs_flow_stats_update(struct sw_flow *, __be16 tcp_flags,

  			   const struct sk_buff *);

  void ovs_flow_stats_get(const struct sw_flow *, struct ovs_flow_stats *,

  			unsigned long *used, __be16 *tcp_flags);

  void ovs_flow_stats_clear(struct sw_flow *);

  u64 ovs_flow_used_time(unsigned long flow_jiffies);

  int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key);

  int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,

  			 struct sk_buff *skb,

  			 struct sw_flow_key *key);

  /* Extract key from packet coming from userspace. */

  int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr,

  				   struct sk_buff *skb,

  				   struct sw_flow_key *key, bool log);

  #endif /* flow.h */