/* SPDX-License-Identifier: GPL-2.0-or-later
 * Copyright Red Hat
 * Author: David Gibson <david@gibson.dropbear.id.au>
 *
 * Tracking for logical "flows" of packets.
 */
#ifndef FLOW_H
#define FLOW_H

/**
 * struct demiflow - Describes a logical packet flow as seen from one "side"
 * @caddr:		Correspondent address (remote address from passt's PoV)
 * @faddr:		Forwarding address (local address from passt's PoV)
 * @cport:		Correspondent port
 * @fport:		Forwarding port
 */
struct demiflow {
	union inany_addr faddr;
	union inany_addr caddr;
	in_port_t fport, cport;
};

/** demiflow_from_af - Initialize a demiflow from addresses
 * @df:		demiflow to initialize
 * @af:		Address family for @faddr and @caddr
 * @faddr:	Forwarding address (pointer to in_addr or in6_addr)
 * @fport:	Forwarding port
 * @caddr:	Correspondent address (pointer to in_addr or in6_addr)
 * @cport:	Correspondent port
 */
static inline void demiflow_from_af(struct demiflow *df, int af,
				    const void *faddr, in_port_t fport,
				    const void *caddr, in_port_t cport)
{
	inany_from_af(&df->faddr, af, faddr);
	inany_from_af(&df->caddr, af, caddr);
	df->fport = fport;
	df->cport = cport;
}

/**
 * demiflow_eq() - Check if two demiflows are equal
 * @left, @right:	Demiflows to compare
 *
 * Return: true if equal, false otherwise
 */
static inline bool demiflow_eq(const struct demiflow *left,
			       const struct demiflow *right)
{
	return memcmp(left, right, sizeof(struct demiflow)) == 0;
}

/**
 * demiflow_hash() - Calculate hash value for a demiflow
 * @df:		Demiflow
 * @k:		Hash secret (128-bits as array of 2 64-bit words)
 *
 * Return: hash value
 */
static inline unsigned int demiflow_hash(const struct demiflow *df,
					 const uint64_t *k)
{
	return siphash_36b((uint8_t *)df, k);
}

#endif /* FLOW_H */