/* SPDX-License-Identifier: GPL-2.0 */
/*
 * TCP ROCCET congestion control interface
 */
#ifndef __TCP_ROCCET_H
#define __TCP_ROCCET_H 1

#include <linux/math64.h>

/* State in which roccet currently operates */
enum roccet_state {
	LAUNCH,
	ORBITER,
	RTT_PROBE,
	RTT_PROBE_REFILL,
	DRAIN
};

/* TCP ROCCET struct based on the original BICTCP struct with
 * additions specific to the ROCCET-Algorithm.
 */
struct roccettcp {
	u32 cnt;	/* increase cwnd by 1 after ACKs */
	u32 last_max_cwnd;	/* last maximum snd_cwnd */
	u32 last_cwnd;	/* the last snd_cwnd */
	u32 last_time;	/* time when updated last_cwnd */
	u32 bic_origin_point;	/* origin point of bic function */
	u32 bic_K;	/* time to origin point from the
			 * beginning of the current epoch
			 */
	u32 delay_min;	/* min delay (usec) */
	u32 epoch_start;	/* beginning of an epoch */
	u32 ack_cnt;	/* number of acks */
	u32 tcp_cwnd;	/* estimated tcp cwnd */
	u32 curr_rtt;	/* last sample rtt of current round */

	u32 roccet_last_event_time_us; /* The last time ROCCET was triggered */
	u32 curr_min_rtt;	/* The current observed minRTT */
	u32 next_min_rtt_probe;	/* Next time to probe the minRTT */
	u32 probe_min_rtt_until;	/* End of minRTT probing period */
	u32 refill_until;	/* End of pipe refill after minRTT probe */
	u32 cwnd_before_min_rtt_probe;	/* cwnd before min RTT probeing */
	u32 curr_srrtt;	/* srRTT calculated based on the latest ACK */
	u32 next_srrtt_check;	/* Next check for srRTT */
	u32 last_rtt;	/* sample rtt of previous round.
			 * Used for jitter calculation
			 */

	u32 interval_snd_seq_start;
	u32 interval_una_seq_start;

	u32 ack_rate_last_rate_time;	/* Timestamp of the last ACK-rate */
	u16 ack_rate_last_rate;	/* Last ACK-rate */
	u16 ack_rate_curr_rate;	/* Current ACK-rate */
	u16 ack_rate_cnt;	/* Used for counting acks */

	bool ece_received;	/* Set to true if an ECE bit was received */
	enum roccet_state state; /* State in which roccet currently operates */
};

#endif /* __TCP_ROCCET_H */