include/linux/tfrc.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 #ifndef _LINUX_TFRC_H_
0003 #define _LINUX_TFRC_H_
0004 /*
0005  *  TFRC - Data Structures for the TCP-Friendly Rate Control congestion
0006  *         control mechanism as specified in RFC 3448.
0007  *
0008  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
0009  *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
0010  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
0011  *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
0012  */
0013 #include <linux/types.h>
0014
0015 /**     tfrc_rx_info    -    TFRC Receiver Data Structure
0016  *
0017  *  @tfrcrx_x_recv: receiver estimate of sending rate (3.2.2)
0018  *  @tfrcrx_rtt:    round-trip-time (communicated by sender)
0019  *  @tfrcrx_p:  current estimate of loss event rate (3.2.2)
0020  */
0021 struct tfrc_rx_info {
0022     __u32 tfrcrx_x_recv;
0023     __u32 tfrcrx_rtt;
0024     __u32 tfrcrx_p;
0025 };
0026
0027 /**     tfrc_tx_info    -    TFRC Sender Data Structure
0028  *
0029  *  @tfrctx_x:  computed transmit rate (4.3 (4))
0030  *  @tfrctx_x_recv: receiver estimate of send rate (4.3)
0031  *  @tfrctx_x_calc: return value of throughput equation (3.1)
0032  *  @tfrctx_rtt:    (moving average) estimate of RTT (4.3)
0033  *  @tfrctx_p:  current loss event rate (5.4)
0034  *  @tfrctx_rto:    estimate of RTO, equals 4*RTT (4.3)
0035  *  @tfrctx_ipi:    inter-packet interval (4.6)
0036  *
0037  *  Note: X and X_recv are both maintained in units of 64 * bytes/second. This
0038  *        enables a finer resolution of sending rates and avoids problems with
0039  *        integer arithmetic; u32 is not sufficient as scaling consumes 6 bits.
0040  */
0041 struct tfrc_tx_info {
0042     __u64 tfrctx_x;
0043     __u64 tfrctx_x_recv;
0044     __u32 tfrctx_x_calc;
0045     __u32 tfrctx_rtt;
0046     __u32 tfrctx_p;
0047     __u32 tfrctx_rto;
0048     __u32 tfrctx_ipi;
0049 };
0050
0051 #endif /* _LINUX_TFRC_H_ */