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freebsd-dev/sys/netinet/khelp/h_ertt.h

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Import the ERTT (Enhanced Round Trip Time) Khelp module. ERTT uses the Khelp/Hhook KPIs to hook into the TCP stack and maintain a per-connection, low noise estimate of the instantaneous RTT. ERTT's implementation is robust even in the face of delayed acknowledgements and/or TSO being in use for a connection. A high quality, low noise RTT estimate is a requirement for applications such as delay-based congestion control, for which we will be importing some algorithm implementations shortly. In collaboration with: David Hayes <dahayes at swin edu au> and Grenville Armitage <garmitage at swin edu au> Sponsored by: FreeBSD Foundation Reviewed by: bz and others along the way MFC after: 3 months
2011-01-24 23:08:38 +00:00
/*-
sys: general adoption of SPDX licensing ID tags. Mainly focus on files that use BSD 2-Clause license, however the tool I was using misidentified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. No functional change intended.
2017-11-27 15:23:17 +00:00
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
Import the ERTT (Enhanced Round Trip Time) Khelp module. ERTT uses the Khelp/Hhook KPIs to hook into the TCP stack and maintain a per-connection, low noise estimate of the instantaneous RTT. ERTT's implementation is robust even in the face of delayed acknowledgements and/or TSO being in use for a connection. A high quality, low noise RTT estimate is a requirement for applications such as delay-based congestion control, for which we will be importing some algorithm implementations shortly. In collaboration with: David Hayes <dahayes at swin edu au> and Grenville Armitage <garmitage at swin edu au> Sponsored by: FreeBSD Foundation Reviewed by: bz and others along the way MFC after: 3 months
2011-01-24 23:08:38 +00:00
* Copyright (c) 2009-2010
* Swinburne University of Technology, Melbourne, Australia
* Copyright (c) 2010 Lawrence Stewart <lstewart@freebsd.org>
* All rights reserved.
*
* This software was developed at the Centre for Advanced Internet
Use the full and proper company name for Swinburne University of Technology throughout the source tree. Requested by: Grenville Armitage, Director of CAIA at Swinburne University of Technology MFC after: 3 days
2011-04-12 08:13:18 +00:00
* Architectures, Swinburne University of Technology, by David Hayes, made
* possible in part by a grant from the Cisco University Research Program Fund
* at Community Foundation Silicon Valley.
Import the ERTT (Enhanced Round Trip Time) Khelp module. ERTT uses the Khelp/Hhook KPIs to hook into the TCP stack and maintain a per-connection, low noise estimate of the instantaneous RTT. ERTT's implementation is robust even in the face of delayed acknowledgements and/or TSO being in use for a connection. A high quality, low noise RTT estimate is a requirement for applications such as delay-based congestion control, for which we will be importing some algorithm implementations shortly. In collaboration with: David Hayes <dahayes at swin edu au> and Grenville Armitage <garmitage at swin edu au> Sponsored by: FreeBSD Foundation Reviewed by: bz and others along the way MFC after: 3 months
2011-01-24 23:08:38 +00:00
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* The ERTT (Enhanced Round Trip Time) Khelp module calculates an estimate of
* the instantaneous TCP RTT which, for example, is used by delay-based
* congestion control schemes. When the module is loaded, ERTT data is
* calculated for each active TCP connection and encapsulated within a
* "struct ertt".
*
* This software was first released in 2010 by David Hayes and Lawrence Stewart
Use the full and proper company name for Swinburne University of Technology throughout the source tree. Requested by: Grenville Armitage, Director of CAIA at Swinburne University of Technology MFC after: 3 days
2011-04-12 08:13:18 +00:00
* whilst working on the NewTCP research project at Swinburne University of
* Technology's Centre for Advanced Internet Architectures, Melbourne,
* Australia, which was made possible in part by a grant from the Cisco
* University Research Program Fund at Community Foundation Silicon Valley.
* Testing and development was further assisted by a grant from the FreeBSD
* Foundation. More details are available at:
Import the ERTT (Enhanced Round Trip Time) Khelp module. ERTT uses the Khelp/Hhook KPIs to hook into the TCP stack and maintain a per-connection, low noise estimate of the instantaneous RTT. ERTT's implementation is robust even in the face of delayed acknowledgements and/or TSO being in use for a connection. A high quality, low noise RTT estimate is a requirement for applications such as delay-based congestion control, for which we will be importing some algorithm implementations shortly. In collaboration with: David Hayes <dahayes at swin edu au> and Grenville Armitage <garmitage at swin edu au> Sponsored by: FreeBSD Foundation Reviewed by: bz and others along the way MFC after: 3 months
2011-01-24 23:08:38 +00:00
* http://caia.swin.edu.au/urp/newtcp/
*/
#ifndef _NETINET_KHELP_H_ERTT_
#define _NETINET_KHELP_H_ERTT_
struct txseginfo;
/* Structure used as the ertt data block. */
struct ertt {
/* Information about transmitted segments to aid in RTT calculation. */
TAILQ_HEAD(txseginfo_head, txseginfo) txsegi_q;
/* Bytes TX so far in marked RTT. */
long bytes_tx_in_rtt;
/* Final version of above. */
long bytes_tx_in_marked_rtt;
/* cwnd for marked RTT. */
unsigned long marked_snd_cwnd;
/* Per-packet measured RTT. */
int rtt;
/* Maximum RTT measured. */
int maxrtt;
/* Minimum RTT measured. */
int minrtt;
/* Guess if the receiver is using delayed ack. */
int dlyack_rx;
/* Keep track of inconsistencies in packet timestamps. */
int timestamp_errors;
/* RTT for a marked packet. */
int markedpkt_rtt;
/* Flags to signal conditions between hook function calls. */
uint32_t flags;
};
/* Flags for struct ertt. */
#define ERTT_NEW_MEASUREMENT 0x01
#define ERTT_MEASUREMENT_IN_PROGRESS 0x02
#define ERTT_TSO_DISABLED 0x04
#endif /* _NETINET_KHELP_H_ERTT_ */
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