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_ */