/* 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