dbc4240942
Control Algorithms for FreeBSD" FreeBSD Foundation funded project. More details about the project are available at: http://caia.swin.edu.au/freebsd/5cc/ - Add a KPI and supporting infrastructure to allow modular congestion control algorithms to be used in the net stack. Algorithms can maintain per-connection state if required, and connections maintain their own algorithm pointer, which allows different connections to concurrently use different algorithms. The TCP_CONGESTION socket option can be used with getsockopt()/setsockopt() to programmatically query or change the congestion control algorithm respectively from within an application at runtime. - Integrate the framework with the TCP stack in as least intrusive a manner as possible. Care was also taken to develop the framework in a way that should allow integration with other congestion aware transport protocols (e.g. SCTP) in the future. The hope is that we will one day be able to share a single set of congestion control algorithm modules between all congestion aware transport protocols. - Introduce a new congestion recovery (TF_CONGRECOVERY) state into the TCP stack and use it to decouple the meaning of recovery from a congestion event and recovery from packet loss (TF_FASTRECOVERY) a la RFC2581. ECN and delay based congestion control protocols don't generally need to recover from packet loss and need a different way to note a congestion recovery episode within the stack. - Remove the net.inet.tcp.newreno sysctl, which simplifies some portions of code and ensures the stack always uses the appropriate mechanisms for recovering from packet loss during a congestion recovery episode. - Extract the NewReno congestion control algorithm from the TCP stack and massage it into module form. NewReno is always built into the kernel and will remain the default algorithm for the forseeable future. Implementations of additional different algorithms will become available in the near future. - Bump __FreeBSD_version to 900025 and note in UPDATING that rebuilding code that relies on the size of "struct tcpcb" is required. Many thanks go to the Cisco University Research Program Fund at Community Foundation Silicon Valley and the FreeBSD Foundation. Their support of our work at the Centre for Advanced Internet Architectures, Swinburne University of Technology is greatly appreciated. In collaboration with: David Hayes <dahayes at swin edu au> and Grenville Armitage <garmitage at swin edu au> Sponsored by: Cisco URP, FreeBSD Foundation Reviewed by: rpaulo Tested by: David Hayes (and many others over the years) MFC after: 3 months
71 lines
2.8 KiB
C
71 lines
2.8 KiB
C
/*-
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* Copyright (c) 2009-2010 Lawrence Stewart <lstewart@freebsd.org>
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* All rights reserved.
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*
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* This software was developed by Lawrence Stewart while studying at the Centre
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* for Advanced Internet Architectures, Swinburne University, made possible in
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* part by a grant from the Cisco University Research Program Fund at Community
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* Foundation Silicon Valley.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* This software was first released in 2009 by Lawrence Stewart as part of the
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* NewTCP research project at Swinburne University's Centre for Advanced
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* Internet Architectures, Melbourne, Australia, which was made possible in part
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* by a grant from the Cisco University Research Program Fund at Community
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* Foundation Silicon Valley. More details are available at:
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* http://caia.swin.edu.au/urp/newtcp/
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*/
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#ifndef _NETINET_CC_MODULE_H_
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#define _NETINET_CC_MODULE_H_
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/*
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* Allows a CC algorithm to manipulate a commonly named CC variable regardless
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* of the transport protocol and associated C struct.
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* XXXLAS: Out of action until the work to support SCTP is done.
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*
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#define CCV(ccv, what) \
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(*( \
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(ccv)->type == IPPROTO_TCP ? &(ccv)->ccvc.tcp->what : \
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&(ccv)->ccvc.sctp->what \
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))
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*/
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#define CCV(ccv, what) (ccv)->ccvc.tcp->what
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#define DECLARE_CC_MODULE(ccname, ccalgo) \
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static moduledata_t cc_##ccname = { \
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.name = #ccname, \
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.evhand = cc_modevent, \
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.priv = ccalgo \
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}; \
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DECLARE_MODULE(ccname, cc_##ccname, \
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SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY)
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int cc_modevent(module_t mod, int type, void *data);
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#endif /* _NETINET_CC_MODULE_H_ */
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