/* 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_PRP_PRIVATE_H
  #define __HSR_PRP_PRIVATE_H
  
  #include <linux/netdevice.h>
  #include <linux/list.h>
  #include <linux/if_vlan.h>
  
  /* Time constants as specified in the HSR specification (IEC-62439-3 2010)
   * Table 8.
   * All values in milliseconds.
   */
  #define HSR_PRP_LIFE_CHECK_INTERVAL              2000 /* ms */
  #define HSR_PRP_NODE_FORGET_TIME                60000 /* ms */
  #define HSR_PRP_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 HSR_PRP_MAX_SLAVE_DIFF			 3000 /* ms */
  #define HSR_PRP_SEQNR_START			(USHRT_MAX - 1024)
  #define HSR_PRP_SUP_SEQNR_START		(HSR_PRP_SEQNR_START / 2)
  /* How often shall we check for broken ring and remove node entries older than
   * HSR_NODE_FORGET_TIME?
   */
  #define HSR_PRP_PRUNE_PERIOD			 3000 /* ms */
  
  #define HSR_TLV_ANNOUNCE		   22
  #define HSR_TLV_LIFE_CHECK		   23
  /* PRP V1 life check for Duplicate discard */
  #define PRP_TLV_LIFE_CHECK_DD		   20
  /* PRP V1 life check for Duplicate Accept */
  #define PRP_TLV_LIFE_CHECK_DA		   21
  
  /* 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_PRP_HLEN	6
  
  #define HSR_PRP_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;
  
  struct hsr_vlan_ethhdr {
  	struct vlan_ethhdr vlanhdr;
  	struct hsr_tag	hsr_tag;
  } __packed;
  
  /* HSR/PRP Supervision Frame data types.
   * Field names as defined in the IEC:2012 standard for HSR.
   */
  struct hsr_prp_sup_tag {
  	__be16		path_and_HSR_Ver;
  	__be16		sequence_nr;
  	__u8		HSR_TLV_type;
  	__u8		HSR_TLV_length;
  } __packed;
  
  struct hsr_prp_sup_payload {
  	unsigned char	mac_address_a[ETH_ALEN];
  } __packed;
  
  static inline u16 get_hsr_stag_path(struct hsr_prp_sup_tag *hst)
  {
  	return get_hsr_tag_path((struct hsr_tag *)hst);
  }
  
  static inline u16 get_hsr_stag_HSR_ver(struct hsr_prp_sup_tag *hst)
  {
  	return get_hsr_tag_LSDU_size((struct hsr_tag *)hst);
  }
  
  static inline void set_hsr_stag_path(struct hsr_prp_sup_tag *hst, u16 path)
  {
  	set_hsr_tag_path((struct hsr_tag *)hst, path);
  }
  
  static inline void set_hsr_stag_HSR_ver(struct hsr_prp_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_prp_sup_tag	hsr_sup;
  } __packed;
  
  struct hsrv1_ethhdr_sp {
  	struct ethhdr		ethhdr;
  	struct hsr_tag		hsr;
  	struct hsr_prp_sup_tag	hsr_sup;
  } __packed;
  
  enum hsr_prp_port_type {
  	HSR_PRP_PT_NONE = 0,	/* Must be 0, used by framereg */
  	HSR_PRP_PT_SLAVE_A,
  	HSR_PRP_PT_SLAVE_B,
  	HSR_PRP_PT_INTERLINK,
  	HSR_PRP_PT_MASTER,
  	HSR_PRP_PT_PORTS,	/* This must be the last item in the enum */
  };
  
  /* PRP Redunancy Control Trailor (RCT).
   * As defined in IEC-62439-4:2012, the PRP RCT is really { sequence Nr,
   * Lan indentifier (LanId), LSDU_size and PRP_suffix = 0x88FB }.
   *
   * Field names as defined in the IEC:2012 standard for PRP.
   */
  struct prp_rct {
  	__be16		sequence_nr;
  	__be16		lan_id_and_LSDU_size;
  	__be16		PRP_suffix;
  } __packed;
  
  static inline u16 get_prp_LSDU_size(struct prp_rct *rct)
  {
  	return ntohs(rct->lan_id_and_LSDU_size) & 0x0FFF;
  }
  
  static inline void set_prp_lan_id(struct prp_rct *rct, u16 lan_id)
  {
  	rct->lan_id_and_LSDU_size = htons(
  			(ntohs(rct->lan_id_and_LSDU_size) & 0x0FFF) |
  			(lan_id << 12));
  }
  static inline void set_prp_LSDU_size(struct prp_rct *rct, u16 LSDU_size)
  {
  	rct->lan_id_and_LSDU_size = htons(
  			(ntohs(rct->lan_id_and_LSDU_size) & 0xF000) |
  			(LSDU_size & 0x0FFF));
  }
  
  struct hsr_prp_lre_if_stats {
  	u32	cnt_tx_a;
  	u32	cnt_tx_b;
  	u32	cnt_rx_wrong_lan_a;
  	u32	cnt_rx_wrong_lan_b;
  	u32	cnt_rx_a;
  	u32	cnt_rx_b;
  	u32	cnt_rx_errors_a;
  	u32	cnt_rx_errors_b;
  	u32	cnt_own_rx_a; /* For HSR only */
  	u32	cnt_own_rx_b; /* For HSR only */
  };
  
  struct hsr_prp_port {
  	struct list_head	port_list;
  	struct net_device	*dev;
  	struct hsr_prp_priv	*priv;
  	enum hsr_prp_port_type	type;
  };
  
  #define HSR	0
  #define PRP	1
  struct hsr_prp_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;
  	bool			rx_offloaded;	/* lre handle in hw */
  	bool			l2_fwd_offloaded; /* L2 forward in hw */
  	struct	hsr_prp_lre_if_stats stats;	/* lre interface stats */
  	int announce_count;
  	u16 sequence_nr;
  	u16 sup_sequence_nr;	/* For HSRv1 separate seq_nr for supervision */
  #define HSR_V0	0
  #define HSR_V1	1
  #define PRP_V1	2
  	u8 prot_version;	/* Indicate if HSRv0 or HSRv1 or PRPv1 */
  #define PRP_LAN_ID	0x5     /* 0x1010 for A and 0x1011 for B. Bit 0 is set
  				 * based on SLAVE_A or SLAVE_B
  				 */
  	u8 net_id;		/* for PRP, it occupies most significant 3 bits
  				 * of lan_id
  				 */
  	spinlock_t seqnr_lock;	/* locking for sequence_nr */
  	unsigned char		sup_multicast_addr[ETH_ALEN];
  #ifdef	CONFIG_DEBUG_FS
  	struct dentry *root_dir;
  	struct dentry *node_tbl_file;
  	struct dentry *stats_file;
  #endif
  };
  
  #define hsr_prp_for_each_port(hsr_prp, port) \
  	list_for_each_entry_rcu((port), &(hsr_prp)->ports, port_list)
  
  struct hsr_prp_port *hsr_prp_get_port(struct hsr_prp_priv *hsr_prp,
  				      enum hsr_prp_port_type pt);
  int hsr_prp_netdev_notify(struct notifier_block *nb, unsigned long event,
  			  void *ptr);
  
  /* 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);
  }
  
  static inline struct prp_rct *skb_get_PRP_rct(struct sk_buff *skb)
  {
  	unsigned char *tail = skb_tail_pointer(skb) - HSR_PRP_HLEN;
  
  	struct prp_rct *rct = (struct prp_rct *)tail;
  
  	if (rct->PRP_suffix == htons(ETH_P_PRP))
  		return rct;
  
  	return NULL;
  }
  
  /* Assume caller has confirmed this skb is PRP suffixed */
  static inline u16 prp_get_skb_sequence_nr(struct prp_rct *rct)
  {
  	return ntohs(rct->sequence_nr);
  }
  
  static inline u16 get_prp_lan_id(struct prp_rct *rct)
  {
  	return ntohs(rct->lan_id_and_LSDU_size) >> 12;
  }
  
  /* assume there is a valid rct */
  static inline bool prp_check_lsdu_size(struct sk_buff *skb,
  				       struct prp_rct *rct,
  				       bool is_sup)
  {
  	struct ethhdr *ethhdr;
  	int expected_lsdu_size;
  
  	if (is_sup) {
  		expected_lsdu_size = HSR_PRP_V1_SUP_LSDUSIZE;
  	} else {
  		ethhdr = (struct ethhdr *)skb_mac_header(skb);
  		expected_lsdu_size = skb->len - 14;
  		if (ethhdr->h_proto == htons(ETH_P_8021Q))
  			expected_lsdu_size -= 4;
  	}
  
  	return (expected_lsdu_size == get_prp_LSDU_size(rct));
  }
  
  int hsr_prp_register_notifier(u8 proto);
  void hsr_prp_unregister_notifier(u8 proto);
  
  #define INC_CNT_TX(type, priv) (((type) == HSR_PRP_PT_SLAVE_A) ? \
  		priv->stats.cnt_tx_a++ : priv->stats.cnt_tx_b++)
  #define INC_CNT_RX_WRONG_LAN(type, priv) (((type) == HSR_PRP_PT_SLAVE_A) ? \
  		priv->stats.cnt_rx_wrong_lan_a++ : \
  		priv->stats.cnt_rx_wrong_lan_b++)
  #define INC_CNT_RX(type, priv) (((type) == HSR_PRP_PT_SLAVE_A) ? \
  		priv->stats.cnt_rx_a++ : priv->stats.cnt_rx_b++)
  #define INC_CNT_RX_ERROR(type, priv) (((type) == HSR_PRP_PT_SLAVE_A) ? \
  		priv->stats.cnt_rx_errors_a++ : priv->stats.cnt_rx_errors_b++)
  #define INC_CNT_OWN_RX(type, priv) (((type) == HSR_PRP_PT_SLAVE_A) ? \
  		priv->stats.cnt_own_rx_a++ : priv->stats.cnt_own_rx_b++)
  
  #if IS_ENABLED(CONFIG_DEBUG_FS)
  int hsr_prp_debugfs_init(struct hsr_prp_priv *priv,
  			 struct net_device *hsr_prp_dev);
  void hsr_prp_debugfs_term(struct hsr_prp_priv *priv);
  #else
  static inline int hsr_prp_debugfs_init(struct hsr_prp_priv *priv,
  				       struct net_device *hsr_prp_dev)
  {
  	return 0;
  }
  
  static inline void hsr_prp_debugfs_term(struct hsr_prp_priv *priv)
  {}
  #endif
  
  #endif /*  __HSR_PRP_PRIVATE_H */