linux/net/ipv4/tcp_htcp.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * H-TCP congestion control. The algorithm is detailed in:
 * R.N.Shorten, D.J.Leith:
 *   "H-TCP: TCP for high-speed and long-distance networks"
 *   Proc. PFLDnet, Argonne, 2004.
 * https://www.hamilton.ie/net/htcp3.pdf
 */

#include <linux/mm.h>
#include <linux/module.h>
#include <net/tcp.h>

#define ALPHA_BASE …
#define BETA_MIN …
#define BETA_MAX …

static int use_rtt_scaling __read_mostly = …;
module_param(use_rtt_scaling, int, 0644);
MODULE_PARM_DESC(…) …;

static int use_bandwidth_switch __read_mostly = …;
module_param(use_bandwidth_switch, int, 0644);
MODULE_PARM_DESC(…) …;

struct htcp { … };

static inline u32 htcp_cong_time(const struct htcp *ca)
{ … }

static inline u32 htcp_ccount(const struct htcp *ca)
{ … }

static inline void htcp_reset(struct htcp *ca)
{ … }

static u32 htcp_cwnd_undo(struct sock *sk)
{ … }

static inline void measure_rtt(struct sock *sk, u32 srtt)
{ … }

static void measure_achieved_throughput(struct sock *sk,
					const struct ack_sample *sample)
{ … }

static inline void htcp_beta_update(struct htcp *ca, u32 minRTT, u32 maxRTT)
{ … }

static inline void htcp_alpha_update(struct htcp *ca)
{ … }

/*
 * After we have the rtt data to calculate beta, we'd still prefer to wait one
 * rtt before we adjust our beta to ensure we are working from a consistent
 * data.
 *
 * This function should be called when we hit a congestion event since only at
 * that point do we really have a real sense of maxRTT (the queues en route
 * were getting just too full now).
 */
static void htcp_param_update(struct sock *sk)
{ … }

static u32 htcp_recalc_ssthresh(struct sock *sk)
{ … }

static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
{ … }

static void htcp_init(struct sock *sk)
{ … }

static void htcp_state(struct sock *sk, u8 new_state)
{ … }

static struct tcp_congestion_ops htcp __read_mostly = …;

static int __init htcp_register(void)
{ … }

static void __exit htcp_unregister(void)
{ … }

module_init(…) …;
module_exit(htcp_unregister);

MODULE_AUTHOR(…) …;
MODULE_LICENSE(…) …;
MODULE_DESCRIPTION(…) …;