LXR linux/include/linux/tfrc.h

   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