1/* SPDX-License-Identifier: GPL-2.0-or-later */
2#ifndef _LINUX_TFRC_H_
3#define _LINUX_TFRC_H_
4/*
5 *  TFRC - Data Structures for the TCP-Friendly Rate Control congestion
6 *         control mechanism as specified in RFC 3448.
7 *
8 *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
9 *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
10 *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
11 *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
12 */
13#include <linux/types.h>
14
15/** 	tfrc_rx_info    -    TFRC Receiver Data Structure
16 *
17 * 	@tfrcrx_x_recv:	receiver estimate of sending rate (3.2.2)
18 * 	@tfrcrx_rtt:	round-trip-time (communicated by sender)
19 * 	@tfrcrx_p:	current estimate of loss event rate (3.2.2)
20 */
21struct tfrc_rx_info {
22  	__u32 tfrcrx_x_recv;
23	__u32 tfrcrx_rtt;
24  	__u32 tfrcrx_p;
25};
26
27/** 	tfrc_tx_info    -    TFRC Sender Data Structure
28 *
29 * 	@tfrctx_x:	computed transmit rate (4.3 (4))
30 * 	@tfrctx_x_recv: receiver estimate of send rate (4.3)
31 * 	@tfrctx_x_calc:	return value of throughput equation (3.1)
32 * 	@tfrctx_rtt:	(moving average) estimate of RTT (4.3)
33 * 	@tfrctx_p:	current loss event rate (5.4)
34 * 	@tfrctx_rto:	estimate of RTO, equals 4*RTT (4.3)
35 * 	@tfrctx_ipi:	inter-packet interval (4.6)
36 *
37 *  Note: X and X_recv are both maintained in units of 64 * bytes/second. This
38 *        enables a finer resolution of sending rates and avoids problems with
39 *        integer arithmetic; u32 is not sufficient as scaling consumes 6 bits.
40 */
41struct tfrc_tx_info {
42	__u64 tfrctx_x;
43	__u64 tfrctx_x_recv;
44	__u32 tfrctx_x_calc;
45	__u32 tfrctx_rtt;
46	__u32 tfrctx_p;
47	__u32 tfrctx_rto;
48	__u32 tfrctx_ipi;
49};
50
51#endif /* _LINUX_TFRC_H_ */
52