/* Copyright 2011-2014 Autronica Fire and Security AS

   *
   * 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; either version 2 of the License, or (at your option)
   * any later version.
   *
   * Author(s):

   *	2011-2014 Arvid Brodin, arvid.brodin@alten.se

   */

  #ifndef __HSR_PRIVATE_H
  #define __HSR_PRIVATE_H

  
  #include <linux/netdevice.h>
  #include <linux/list.h>
  
  
  /* Time constants as specified in the HSR specification (IEC-62439-3 2010)
   * Table 8.
   * All values in milliseconds.
   */
  #define HSR_LIFE_CHECK_INTERVAL		 2000 /* ms */
  #define HSR_NODE_FORGET_TIME		60000 /* ms */
  #define HSR_ANNOUNCE_INTERVAL		  100 /* ms */
  
  
  /* By how much may slave1 and slave2 timestamps of latest received frame from
   * each node differ before we notify of communication problem?
   */
  #define MAX_SLAVE_DIFF			 3000 /* ms */

  #define HSR_SEQNR_START			(USHRT_MAX - 1024)

  #define HSR_SUP_SEQNR_START		(HSR_SEQNR_START / 2)

  
  
  /* How often shall we check for broken ring and remove node entries older than
   * HSR_NODE_FORGET_TIME?
   */
  #define PRUNE_PERIOD			 3000 /* ms */
  
  
  #define HSR_TLV_ANNOUNCE		   22
  #define HSR_TLV_LIFE_CHECK		   23
  
  
  /* HSR Tag.
   * As defined in IEC-62439-3:2010, the HSR tag is really { ethertype = 0x88FB,
   * path, LSDU_size, sequence Nr }. But we let eth_header() create { h_dest,
   * h_source, h_proto = 0x88FB }, and add { path, LSDU_size, sequence Nr,
   * encapsulated protocol } instead.

   *
   * Field names as defined in the IEC:2010 standard for HSR.

   */

  struct hsr_tag {
  	__be16		path_and_LSDU_size;
  	__be16		sequence_nr;
  	__be16		encap_proto;
  } __packed;

  #define HSR_HLEN	6

  #define HSR_V1_SUP_LSDUSIZE		52

  /* The helper functions below assumes that 'path' occupies the 4 most
   * significant bits of the 16-bit field shared by 'path' and 'LSDU_size' (or
   * equivalently, the 4 most significant bits of HSR tag byte 14).
   *
   * This is unclear in the IEC specification; its definition of MAC addresses
   * indicates the spec is written with the least significant bit first (to the
   * left). This, however, would mean that the LSDU field would be split in two
   * with the path field in-between, which seems strange. I'm guessing the MAC
   * address definition is in error.
   */
  static inline u16 get_hsr_tag_path(struct hsr_tag *ht)
  {
  	return ntohs(ht->path_and_LSDU_size) >> 12;
  }
  
  static inline u16 get_hsr_tag_LSDU_size(struct hsr_tag *ht)
  {
  	return ntohs(ht->path_and_LSDU_size) & 0x0FFF;
  }
  
  static inline void set_hsr_tag_path(struct hsr_tag *ht, u16 path)
  {
  	ht->path_and_LSDU_size = htons(
  			(ntohs(ht->path_and_LSDU_size) & 0x0FFF) | (path << 12));
  }
  
  static inline void set_hsr_tag_LSDU_size(struct hsr_tag *ht, u16 LSDU_size)
  {
  	ht->path_and_LSDU_size = htons(
  			(ntohs(ht->path_and_LSDU_size) & 0xF000) |
  			(LSDU_size & 0x0FFF));
  }
  
  struct hsr_ethhdr {
  	struct ethhdr	ethhdr;
  	struct hsr_tag	hsr_tag;
  } __packed;
  
  
  /* HSR Supervision Frame data types.
   * Field names as defined in the IEC:2010 standard for HSR.
   */
  struct hsr_sup_tag {
  	__be16		path_and_HSR_Ver;
  	__be16		sequence_nr;
  	__u8		HSR_TLV_Type;
  	__u8		HSR_TLV_Length;
  } __packed;
  
  struct hsr_sup_payload {
  	unsigned char	MacAddressA[ETH_ALEN];
  } __packed;
  
  static inline u16 get_hsr_stag_path(struct hsr_sup_tag *hst)
  {
  	return get_hsr_tag_path((struct hsr_tag *) hst);
  }
  
  static inline u16 get_hsr_stag_HSR_ver(struct hsr_sup_tag *hst)
  {
  	return get_hsr_tag_LSDU_size((struct hsr_tag *) hst);
  }
  
  static inline void set_hsr_stag_path(struct hsr_sup_tag *hst, u16 path)
  {
  	set_hsr_tag_path((struct hsr_tag *) hst, path);
  }
  
  static inline void set_hsr_stag_HSR_Ver(struct hsr_sup_tag *hst, u16 HSR_Ver)
  {
  	set_hsr_tag_LSDU_size((struct hsr_tag *) hst, HSR_Ver);
  }

  struct hsrv0_ethhdr_sp {
  	struct ethhdr		ethhdr;
  	struct hsr_sup_tag	hsr_sup;
  } __packed;
  
  struct hsrv1_ethhdr_sp {

  	struct ethhdr		ethhdr;

  	struct hsr_tag		hsr;

  	struct hsr_sup_tag	hsr_sup;
  } __packed;

  enum hsr_port_type {
  	HSR_PT_NONE = 0,	/* Must be 0, used by framereg */
  	HSR_PT_SLAVE_A,
  	HSR_PT_SLAVE_B,
  	HSR_PT_INTERLINK,
  	HSR_PT_MASTER,
  	HSR_PT_PORTS,	/* This must be the last item in the enum */
  };
  
  struct hsr_port {
  	struct list_head	port_list;
  	struct net_device	*dev;
  	struct hsr_priv		*hsr;
  	enum hsr_port_type	type;

  };

  
  struct hsr_priv {

  	struct rcu_head		rcu_head;

  	struct list_head	ports;

  	struct list_head	node_db;	/* Known HSR nodes */

  	struct list_head	self_node_db;	/* MACs of slaves */
  	struct timer_list	announce_timer;	/* Supervision frame dispatch */

  	struct timer_list	prune_timer;

  	int announce_count;
  	u16 sequence_nr;

  	u16 sup_sequence_nr;			/* For HSRv1 separate seq_nr for supervision */
  	u8 protVersion;					/* Indicate if HSRv0 or HSRv1. */

  	spinlock_t seqnr_lock;			/* locking for sequence_nr */
  	unsigned char		sup_multicast_addr[ETH_ALEN];
  };

  #define hsr_for_each_port(hsr, port) \
  	list_for_each_entry_rcu((port), &(hsr)->ports, port_list)

  struct hsr_port *hsr_port_get_hsr(struct hsr_priv *hsr, enum hsr_port_type pt);

  /* Caller must ensure skb is a valid HSR frame */
  static inline u16 hsr_get_skb_sequence_nr(struct sk_buff *skb)
  {
  	struct hsr_ethhdr *hsr_ethhdr;
  
  	hsr_ethhdr = (struct hsr_ethhdr *) skb_mac_header(skb);
  	return ntohs(hsr_ethhdr->hsr_tag.sequence_nr);
  }

  #endif /*  __HSR_PRIVATE_H */