/* SPDX-License-Identifier: GPL-2.0-or-later */

  /*
   *	Linux ethernet bridge
   *
   *	Authors:
   *	Lennert Buytenhek		<buytenh@gnu.org>

   */
  
  #ifndef _BR_PRIVATE_STP_H
  #define _BR_PRIVATE_STP_H
  
  #define BPDU_TYPE_CONFIG 0
  #define BPDU_TYPE_TCN 0x80

  /* IEEE 802.1D-1998 timer values */
  #define BR_MIN_HELLO_TIME	(1*HZ)
  #define BR_MAX_HELLO_TIME	(10*HZ)
  
  #define BR_MIN_FORWARD_DELAY	(2*HZ)
  #define BR_MAX_FORWARD_DELAY	(30*HZ)
  
  #define BR_MIN_MAX_AGE		(6*HZ)
  #define BR_MAX_MAX_AGE		(40*HZ)
  
  #define BR_MIN_PATH_COST	1
  #define BR_MAX_PATH_COST	65535

  struct br_config_bpdu {
  	unsigned int	topology_change:1;
  	unsigned int	topology_change_ack:1;

  	bridge_id	root;
  	int		root_path_cost;
  	bridge_id	bridge_id;
  	port_id		port_id;
  	int		message_age;
  	int		max_age;
  	int		hello_time;
  	int		forward_delay;
  };
  
  /* called under bridge lock */
  static inline int br_is_designated_port(const struct net_bridge_port *p)
  {
  	return !memcmp(&p->designated_bridge, &p->br->bridge_id, 8) &&
  		(p->designated_port == p->port_id);
  }
  
  
  /* br_stp.c */

  void br_become_root_bridge(struct net_bridge *br);
  void br_config_bpdu_generation(struct net_bridge *);
  void br_configuration_update(struct net_bridge *);
  void br_port_state_selection(struct net_bridge *);
  void br_received_config_bpdu(struct net_bridge_port *p,
  			     const struct br_config_bpdu *bpdu);
  void br_received_tcn_bpdu(struct net_bridge_port *p);
  void br_transmit_config(struct net_bridge_port *p);
  void br_transmit_tcn(struct net_bridge *br);
  void br_topology_change_detection(struct net_bridge *br);

  void __br_set_topology_change(struct net_bridge *br, unsigned char val);

  
  /* br_stp_bpdu.c */

  void br_send_config_bpdu(struct net_bridge_port *, struct br_config_bpdu *);
  void br_send_tcn_bpdu(struct net_bridge_port *);

  
  #endif