text: /*
   * Copyright (c) 2007-2013 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/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 <net/inet_ecn.h>
  #include <net/ip_tunnels.h>
  
  
  //BN
  #define _SR_
  #ifdef _SR_
  #define MAX_IPV6_SEGMENTS 4
  struct ipv6_addr {
          __be32 addr[4];
  };
  struct ipv6_segments {
          struct ipv6_addr ipv6_segments[MAX_IPV6_SEGMENTS];
          uint8_t segment_used;
  };
  #endif
  
  struct sw_flow_mask;
  struct flow_table;
  
  struct sw_flow_actions {
  	struct rcu_head rcu;
  	u32 actions_len;
  	struct nlattr actions[];
  };
  
  /* Used to memset ovs_key_ipv4_tunnel padding. */
  #define OVS_TUNNEL_KEY_SIZE					\
          (offsetof(struct ovs_key_ipv4_tunnel, ipv4_ttl) + 	\
           FIELD_SIZEOF(struct ovs_key_ipv4_tunnel, ipv4_ttl))
  
  struct ovs_key_ipv4_tunnel {
  	__be64 tun_id;
  	__be32 ipv4_src;
  	__be32 ipv4_dst;
  	__be16 tun_flags;
  	u8   ipv4_tos;
  	u8   ipv4_ttl;
  };
  
  static inline void ovs_flow_tun_key_init(struct ovs_key_ipv4_tunnel *tun_key,
  					 const struct iphdr *iph, __be64 tun_id,
  					 __be16 tun_flags)
  {
  	tun_key->tun_id = tun_id;
  	tun_key->ipv4_src = iph->saddr;
  	tun_key->ipv4_dst = iph->daddr;
  	tun_key->ipv4_tos = iph->tos;
  	tun_key->ipv4_ttl = iph->ttl;
  	tun_key->tun_flags = tun_flags;
  
  	/* clear struct padding. */
  	memset((unsigned char *) tun_key + OVS_TUNNEL_KEY_SIZE, 0,
  	       sizeof(*tun_key) - OVS_TUNNEL_KEY_SIZE);
  }
  
  struct sw_flow_key {
  	struct ovs_key_ipv4_tunnel 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). */
  	} phy;
  	struct {
  		u8     src[ETH_ALEN];	/* Ethernet source address. */
  		u8     dst[ETH_ALEN];	/* Ethernet destination address. */
  		__be16 tci;		/* 0 if no VLAN, VLAN_TAG_PRESENT set otherwise. */
  		__be16 type;		/* Ethernet frame type. */
  	} eth;
  	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;
  	union {
  		struct {
  			struct {
  				__be32 src;	/* IP source address. */
  				__be32 dst;	/* IP destination address. */
  			} addr;
  			union {
  				struct {
  					__be16 src;		/* TCP/UDP/SCTP source port. */
  					__be16 dst;		/* TCP/UDP/SCTP destination port. */
  				} tp;
  				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. */
  			struct {
  				__be16 src;		/* TCP/UDP/SCTP source port. */
  				__be16 dst;		/* TCP/UDP/SCTP destination port. */
  			} tp;
  			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;
  	};
  } __aligned(BITS_PER_LONG/8); /* Ensure that we can do comparisons as longs. */
  
  struct sw_flow {
  	struct rcu_head rcu;
  	struct hlist_node hash_node[2];
  	u32 hash;
  
  	struct sw_flow_key key;
  	struct sw_flow_key unmasked_key;
  	struct sw_flow_mask *mask;
  	struct sw_flow_actions __rcu *sf_acts;
  
  	spinlock_t lock;	/* Lock for values below. */
  	unsigned long used;	/* Last used time (in jiffies). */
  	u64 packet_count;	/* Number of packets matched. */
  	u64 byte_count;		/* Number of bytes matched. */
  	u8 tcp_flags;		/* Union of seen TCP flags. */
  };
  
  struct sw_flow_key_range {
  	size_t start;
  	size_t end;
  };
  
  struct sw_flow_match {
  	struct sw_flow_key *key;
  	struct sw_flow_key_range range;
  	struct sw_flow_mask *mask;
  };
  
  void ovs_match_init(struct sw_flow_match *match,
  		struct sw_flow_key *key, struct sw_flow_mask *mask);
  
  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;
  
  int ovs_flow_init(void);
  void ovs_flow_exit(void);
  
  struct sw_flow *ovs_flow_alloc(void);
  void ovs_flow_deferred_free(struct sw_flow *);
  void ovs_flow_free(struct sw_flow *, bool deferred);
  
  struct sw_flow_actions *ovs_flow_actions_alloc(int actions_len);
  void ovs_flow_deferred_free_acts(struct sw_flow_actions *);
  
  int ovs_flow_extract(struct sk_buff *, u16 in_port, struct sw_flow_key *);
  void ovs_flow_used(struct sw_flow *, struct sk_buff *);
  u64 ovs_flow_used_time(unsigned long flow_jiffies);
  int ovs_flow_to_nlattrs(const struct sw_flow_key *,
  		const struct sw_flow_key *, struct sk_buff *);
  int ovs_match_from_nlattrs(struct sw_flow_match *match,
  		      const struct nlattr *,
  		      const struct nlattr *);
  int ovs_flow_metadata_from_nlattrs(struct sw_flow *flow,
  		const struct nlattr *attr);
  
  #define MAX_ACTIONS_BUFSIZE	(32 * 1024)
  #define TBL_MIN_BUCKETS		1024
  
  struct flow_table {
  	struct flex_array *buckets;
  	unsigned int count, n_buckets;
  	struct rcu_head rcu;
  	struct list_head *mask_list;
  	int node_ver;
  	u32 hash_seed;
  	bool keep_flows;
  };
  
  static inline int ovs_flow_tbl_count(struct flow_table *table)
  {
  	return table->count;
  }
  
  static inline int ovs_flow_tbl_need_to_expand(struct flow_table *table)
  {
  	return (table->count > table->n_buckets);
  }
  
  struct sw_flow *ovs_flow_lookup(struct flow_table *,
  				const struct sw_flow_key *);
  struct sw_flow *ovs_flow_lookup_unmasked_key(struct flow_table *table,
  				    struct sw_flow_match *match);
  
  void ovs_flow_tbl_destroy(struct flow_table *table, bool deferred);
  struct flow_table *ovs_flow_tbl_alloc(int new_size);
  struct flow_table *ovs_flow_tbl_expand(struct flow_table *table);
  struct flow_table *ovs_flow_tbl_rehash(struct flow_table *table);
  
  void ovs_flow_insert(struct flow_table *table, struct sw_flow *flow);
  void ovs_flow_remove(struct flow_table *table, struct sw_flow *flow);
  
  struct sw_flow *ovs_flow_dump_next(struct flow_table *table, u32 *bucket, u32 *idx);
  extern const int ovs_key_lens[OVS_KEY_ATTR_MAX + 1];
  int ovs_ipv4_tun_from_nlattr(const struct nlattr *attr,
  			     struct sw_flow_match *match, bool is_mask);
  int ovs_ipv4_tun_to_nlattr(struct sk_buff *skb,
  			   const struct ovs_key_ipv4_tunnel *tun_key,
  			   const struct ovs_key_ipv4_tunnel *output);
  
  bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
  		const struct sw_flow_key *key, int key_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_mask *ovs_sw_flow_mask_alloc(void);
  void ovs_sw_flow_mask_add_ref(struct sw_flow_mask *);
  void ovs_sw_flow_mask_del_ref(struct sw_flow_mask *, bool deferred);
  void ovs_sw_flow_mask_insert(struct flow_table *, struct sw_flow_mask *);
  struct sw_flow_mask *ovs_sw_flow_mask_find(const struct flow_table *,
  		const struct sw_flow_mask *);
  void ovs_flow_key_mask(struct sw_flow_key *dst, const struct sw_flow_key *src,
  		       const struct sw_flow_mask *mask);
  #endif /* flow.h */
  