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  */
21 struct 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  */
41 struct 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