/* * Copyright (c) 2007-2008 * Swinburne University of Technology, Melbourne, Australia. * Copyright (c) 2009-2010 Lawrence Stewart <lstewart@freebsd.org> * Copyright (c) 2010 The FreeBSD Foundation * All rights reserved. * Copyright (c) 2017 by Delphix. All rights reserved. * * This software was developed at the Centre for Advanced Internet * Architectures, Swinburne University of Technology, by Lawrence Stewart and * James Healy, made possible in part by a grant from the Cisco University * Research Program Fund at Community Foundation Silicon Valley. * * Portions of this software were developed at the Centre for Advanced * Internet Architectures, Swinburne University of Technology, Melbourne, * Australia by David Hayes under sponsorship from the FreeBSD Foundation. * * 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. * * $FreeBSD$ */ /* * This software was first released in 2007 by James Healy and Lawrence Stewart * 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. * More details are available at: * http://caia.swin.edu.au/urp/newtcp/ */ #ifndef _NETINET_CC_H_ #define _NETINET_CC_H_ #if (defined(_KERNEL) || defined(_KMEMUSER)) #ifdef __cplusplus extern "C" { #endif #include <netinet/tcp.h> #include <sys/queue.h> #include <sys/rwlock.h> #define CC_ALGO_NAME_MAX 16 /* max congestion control name length */ #define CC_DEFAULT_ALGO_NAME "sunreno" struct tcp_s; struct sctp_s; /* CC housekeeping functions. */ extern struct cc_algo *cc_load_algo(const char *name); extern int cc_register_algo(struct cc_algo *add_cc); extern int cc_deregister_algo(struct cc_algo *remove_cc); /* * Wrapper around transport structs that contain same-named congestion * control variables. Allows algos to be shared amongst multiple CC aware * transports. * * In theory, this code (from FreeBSD) can be used to support pluggable * congestion control for sctp as well as tcp. However, the support for sctp * in FreeBSD is incomplete, and in practice "type" is ignored. cc_module.h * provides a CCV macro which implementations can use to get a variable out of * the protocol-appropriate structure. * * If FreeBSD eventually does extend support for pluggable congestion control * to sctp, we'll need to make sure we're setting "type" appropriately or use * a definition of CCV that ignores it. */ struct cc_var { void *cc_data; /* Per-connection private algorithm data. */ int bytes_this_ack; /* # bytes acked by the current ACK. */ int t_bytes_acked; /* # bytes acked during current RTT */ tcp_seq curack; /* Most recent ACK. */ uint32_t flags; /* Flags for cc_var (see below) */ int type; /* Indicates which ptr is valid in ccvc. */ union ccv_container { struct tcp_s *tcp; struct sctp_s *sctp; } ccvc; uint16_t nsegs; /* # segments coalesced into current chain. */ }; /* * cc_var flags. * * CCF_ABC_SENTAWND is set when a full congestion window of data has been ACKed * according to the Appropriate Byte Counting spec, defined in RFC 3465. */ #define CCF_ABC_SENTAWND 0x0001 /* ABC counted cwnd worth of bytes? */ #define CCF_CWND_LIMITED 0x0002 /* Are we currently cwnd limited? */ #define CCF_FASTRECOVERY 0x0004 /* in NewReno Fast Recovery */ #define CCF_WASFRECOVERY 0x0008 /* was in NewReno Fast Recovery */ #define CCF_CONGRECOVERY 0x0010 /* congestion recovery mode */ #define CCF_WASCRECOVERY 0x0020 /* was in congestion recovery */ /* * In slow-start due to a retransmission timeout. This flag is enabled for the * duration of the slow-start phase. */ #define CCF_RTO 0x0040 /* in slow-start due to timeout */ #define IN_FASTRECOVERY(flags) (flags & CCF_FASTRECOVERY) #define ENTER_FASTRECOVERY(flags) flags |= CCF_FASTRECOVERY #define EXIT_FASTRECOVERY(flags) flags &= ~CCF_FASTRECOVERY #define IN_CONGRECOVERY(flags) (flags & CCF_CONGRECOVERY) #define ENTER_CONGRECOVERY(flags) flags |= CCF_CONGRECOVERY #define EXIT_CONGRECOVERY(flags) flags &= ~CCF_CONGRECOVERY #define IN_RECOVERY(flags) (flags & (CCF_CONGRECOVERY | CCF_FASTRECOVERY)) #define ENTER_RECOVERY(flags) flags |= (CCF_CONGRECOVERY | CCF_FASTRECOVERY) #define EXIT_RECOVERY(flags) flags &= ~(CCF_CONGRECOVERY | CCF_FASTRECOVERY) /* * ACK types passed to the ack_received() hook. * * CC_ACK is passed when an ACK acknowledges previously unACKed data. * CC_DUPACK is passed when a duplicate ACK is received. The conditions under * which an ACK is considered a duplicate ACK are defined in RFC 5681. */ #define CC_ACK 0x0001 /* Regular in sequence ACK. */ #define CC_DUPACK 0x0002 /* Duplicate ACK. */ #define CC_PARTIALACK 0x0004 /* Not yet. */ #define CC_SACK 0x0008 /* Not yet. */ /* * Congestion signal types passed to the cong_signal() hook. The highest order 8 * bits (0x01000000 - 0x80000000) are reserved for CC algos to declare their own * congestion signal types. * * The congestion signals defined here cover the following situations: * CC_ECN: A packet with an Explicit Congestion Notification was received * See RFC 3168. * CC_RTO: A round-trip timeout occured. * CC_RTO_ERR: An ACK was received for a sequence number after we fired an RTO * for that sequence number * CC_NDUPACK: Trigger fast retransmit based on the assumption that receiving * N duplicate ACKs indicates packet loss rather than reordering. Fast * retransmit is followed by fast recovery. Fast retransmit and recovery * were originally described in RFC 2581 and were updated by RFC3782 * (NewReno). In both RFC2581 and RFC3782, N is 3. */ #define CC_ECN 0x00000001 /* ECN marked packet received. */ #define CC_RTO 0x00000002 /* RTO fired. */ #define CC_RTO_ERR 0x00000004 /* RTO fired in error. */ #define CC_NDUPACK 0x00000008 /* Threshold of dupack's reached. */ #define CC_SIGPRIVMASK 0xFF000000 /* Mask to check if sig is private. */ /* * Structure to hold data and function pointers that together represent a * congestion control algorithm. */ struct cc_algo { char name[CC_ALGO_NAME_MAX]; /* Init CC state for a new control block. */ int (*cb_init)(struct cc_var *ccv); /* Cleanup CC state for a terminating control block. */ void (*cb_destroy)(struct cc_var *ccv); /* Init variables for a newly established connection. */ void (*conn_init)(struct cc_var *ccv); /* Called on receipt of an ack. */ void (*ack_received)(struct cc_var *ccv, uint16_t type); /* Called on detection of a congestion signal. */ void (*cong_signal)(struct cc_var *ccv, uint32_t type); /* Called after exiting congestion recovery. */ void (*post_recovery)(struct cc_var *ccv); /* Called when data transfer resumes after an idle period. */ void (*after_idle)(struct cc_var *ccv); STAILQ_ENTRY(cc_algo) entries; }; typedef int cc_walk_func_t(void *, struct cc_algo *); extern int cc_walk_algos(cc_walk_func_t *, void *); /* Macro to obtain the CC algo's struct ptr. */ #define CC_ALGO(tp) ((tp)->tcp_cc_algo) /* Macro to obtain the CC algo's data ptr. */ #define CC_DATA(tp) ((tp)->tcp_ccv.cc_data) #ifdef __cplusplus } #endif #endif /* (defined(_KERNEL) || defined(_KMEMUSER)) */ #endif /* _NETINET_CC_H_ */
