// SPDX-License-Identifier: MIT
/*
Copyright (c) 2007, 2008 by Juliusz Chroboczek
Copyright 2011 by Matthieu Boutier and Juliusz Chroboczek
*/

#ifndef BABEL_ROUTE_H
#define BABEL_ROUTE_H

#include "babel_interface.h"
#include "source.h"

enum babel_diversity {
	DIVERSITY_NONE,
	DIVERSITY_INTERFACE_1,
	DIVERSITY_CHANNEL_1,
	DIVERSITY_CHANNEL,
};

#define DIVERSITY_HOPS 8

struct babel_route {
	struct source *src;
	unsigned short refmetric;
	unsigned short cost;
	unsigned short add_metric;
	unsigned short seqno;
	struct neighbour *neigh;
	unsigned char nexthop[16];
	time_t time;
	unsigned short hold_time;	/* in seconds */
	unsigned short smoothed_metric; /* for route selection */
	time_t smoothed_metric_time;
	short installed;
	unsigned char channels[DIVERSITY_HOPS];
	struct babel_route *next;
};

struct route_stream;

extern int kernel_metric;
extern enum babel_diversity diversity_kind;
extern int diversity_factor;
extern int keep_unfeasible;
extern int smoothing_half_life;

static inline int route_metric(const struct babel_route *route)
{
	int m = (int)route->refmetric + route->cost + route->add_metric;
	return MIN(m, INFINITY);
}

static inline int route_metric_noninterfering(const struct babel_route *route)
{
	int m = (int)route->refmetric + (diversity_factor * route->cost + 128) / 256 +
		route->add_metric;
	m = MAX(m, route->refmetric + 1);
	return MIN(m, INFINITY);
}

struct babel_route *find_route(const unsigned char *prefix, unsigned char plen,
			       struct neighbour *neigh, const unsigned char *nexthop);
struct babel_route *find_installed_route(const unsigned char *prefix, unsigned char plen);
int installed_routes_estimate(void);
void flush_route(struct babel_route *route);
void flush_all_routes(void);
void flush_neighbour_routes(struct neighbour *neigh);
void flush_interface_routes(struct interface *ifp, int v4only);
struct route_stream *route_stream(int installed);
struct babel_route *route_stream_next(struct route_stream *stream);
void route_stream_done(struct route_stream *stream);
void install_route(struct babel_route *route);
void uninstall_route(struct babel_route *route);
int route_feasible(struct babel_route *route);
int route_old(struct babel_route *route);
int route_expired(struct babel_route *route);
int route_interferes(struct babel_route *route, struct interface *ifp);
int update_feasible(struct source *src, unsigned short seqno, unsigned short refmetric);
void change_smoothing_half_life(int half_life);
int route_smoothed_metric(struct babel_route *route);
struct babel_route *find_best_route(const unsigned char *prefix, unsigned char plen, int feasible,
				    struct neighbour *exclude);
struct babel_route *install_best_route(const unsigned char prefix[16], unsigned char plen);
void update_neighbour_metric(struct neighbour *neigh, int change);
void update_interface_metric(struct interface *ifp);
void update_route_metric(struct babel_route *route);
struct babel_route *update_route(const unsigned char *id, const unsigned char *prefix,
				 unsigned char plen, unsigned short seqno,
				 unsigned short refmetric, unsigned short interval,
				 struct neighbour *neigh, const unsigned char *nexthop,
				 const unsigned char *channels, int channels_len);
void retract_neighbour_routes(struct neighbour *neigh);
void send_unfeasible_request(struct neighbour *neigh, int force, unsigned short seqno,
			     unsigned short metric, struct source *src);
void send_triggered_update(struct babel_route *route, struct source *oldsrc, unsigned oldmetric);
void route_changed(struct babel_route *route, struct source *oldsrc, unsigned short oldmetric);
void route_lost(struct source *src, unsigned oldmetric);
void expire_routes(void);

#endif
