89e560f441
Rack includes the following features:
- A different SACK processing scheme (the old sack structures are not used).
- RACK (Recent acknowledgment) where counting dup-acks is no longer done
instead time is used to knwo when to retransmit. (see the I-D)
- TLP (Tail Loss Probe) where we will probe for tail-losses to attempt
to try not to take a retransmit time-out. (see the I-D)
- Burst mitigation using TCPHTPS
- PRR (partial rate reduction) see the RFC.
Once built into your kernel, you can select this stack by either
socket option with the name of the stack is "rack" or by setting
the global sysctl so the default is rack.
Note that any connection that does not support SACK will be kicked
back to the "default" base FreeBSD stack (currently known as "default").
To build this into your kernel you will need to enable in your
kernel:
makeoptions WITH_EXTRA_TCP_STACKS=1
options TCPHPTS
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D15525
341 lines
14 KiB
C
341 lines
14 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 1982, 1986, 1993
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* The Regents of the University of California. All rights reserved.
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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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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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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* @(#)tcp.h 8.1 (Berkeley) 6/10/93
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* $FreeBSD$
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*/
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#ifndef _NETINET_TCP_H_
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#define _NETINET_TCP_H_
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#include <sys/cdefs.h>
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#include <sys/types.h>
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#if __BSD_VISIBLE
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typedef u_int32_t tcp_seq;
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#define tcp6_seq tcp_seq /* for KAME src sync over BSD*'s */
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#define tcp6hdr tcphdr /* for KAME src sync over BSD*'s */
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/*
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* TCP header.
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* Per RFC 793, September, 1981.
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*/
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struct tcphdr {
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u_short th_sport; /* source port */
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u_short th_dport; /* destination port */
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tcp_seq th_seq; /* sequence number */
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tcp_seq th_ack; /* acknowledgement number */
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#if BYTE_ORDER == LITTLE_ENDIAN
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u_char th_x2:4, /* (unused) */
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th_off:4; /* data offset */
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#endif
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#if BYTE_ORDER == BIG_ENDIAN
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u_char th_off:4, /* data offset */
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th_x2:4; /* (unused) */
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#endif
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u_char th_flags;
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#define TH_FIN 0x01
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#define TH_SYN 0x02
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#define TH_RST 0x04
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#define TH_PUSH 0x08
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#define TH_ACK 0x10
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#define TH_URG 0x20
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#define TH_ECE 0x40
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#define TH_CWR 0x80
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#define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG|TH_ECE|TH_CWR)
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#define PRINT_TH_FLAGS "\20\1FIN\2SYN\3RST\4PUSH\5ACK\6URG\7ECE\10CWR"
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u_short th_win; /* window */
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u_short th_sum; /* checksum */
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u_short th_urp; /* urgent pointer */
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};
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#define TCPOPT_EOL 0
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#define TCPOLEN_EOL 1
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#define TCPOPT_PAD 0 /* padding after EOL */
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#define TCPOLEN_PAD 1
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#define TCPOPT_NOP 1
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#define TCPOLEN_NOP 1
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#define TCPOPT_MAXSEG 2
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#define TCPOLEN_MAXSEG 4
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#define TCPOPT_WINDOW 3
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#define TCPOLEN_WINDOW 3
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#define TCPOPT_SACK_PERMITTED 4
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#define TCPOLEN_SACK_PERMITTED 2
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#define TCPOPT_SACK 5
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#define TCPOLEN_SACKHDR 2
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#define TCPOLEN_SACK 8 /* 2*sizeof(tcp_seq) */
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#define TCPOPT_TIMESTAMP 8
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#define TCPOLEN_TIMESTAMP 10
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#define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */
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#define TCPOPT_SIGNATURE 19 /* Keyed MD5: RFC 2385 */
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#define TCPOLEN_SIGNATURE 18
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#define TCPOPT_FAST_OPEN 34
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#define TCPOLEN_FAST_OPEN_EMPTY 2
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/* Miscellaneous constants */
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#define MAX_SACK_BLKS 6 /* Max # SACK blocks stored at receiver side */
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#define TCP_MAX_SACK 4 /* MAX # SACKs sent in any segment */
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/*
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* The default maximum segment size (MSS) to be used for new TCP connections
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* when path MTU discovery is not enabled.
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*
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* RFC879 derives the default MSS from the largest datagram size hosts are
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* minimally required to handle directly or through IP reassembly minus the
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* size of the IP and TCP header. With IPv6 the minimum MTU is specified
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* in RFC2460.
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*
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* For IPv4 the MSS is 576 - sizeof(struct tcpiphdr)
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* For IPv6 the MSS is IPV6_MMTU - sizeof(struct ip6_hdr) - sizeof(struct tcphdr)
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*
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* We use explicit numerical definition here to avoid header pollution.
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*/
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#define TCP_MSS 536
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#define TCP6_MSS 1220
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/*
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* Limit the lowest MSS we accept for path MTU discovery and the TCP SYN MSS
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* option. Allowing low values of MSS can consume significant resources and
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* be used to mount a resource exhaustion attack.
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* Connections requesting lower MSS values will be rounded up to this value
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* and the IP_DF flag will be cleared to allow fragmentation along the path.
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*
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* See tcp_subr.c tcp_minmss SYSCTL declaration for more comments. Setting
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* it to "0" disables the minmss check.
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*
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* The default value is fine for TCP across the Internet's smallest official
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* link MTU (256 bytes for AX.25 packet radio). However, a connection is very
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* unlikely to come across such low MTU interfaces these days (anno domini 2003).
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*/
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#define TCP_MINMSS 216
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#define TCP_MAXWIN 65535 /* largest value for (unscaled) window */
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#define TTCP_CLIENT_SND_WND 4096 /* dflt send window for T/TCP client */
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#define TCP_MAX_WINSHIFT 14 /* maximum window shift */
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#define TCP_MAXBURST 4 /* maximum segments in a burst */
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#define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */
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#define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr))
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/* max space left for options */
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#define TCP_FASTOPEN_MIN_COOKIE_LEN 4 /* Per RFC7413 */
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#define TCP_FASTOPEN_MAX_COOKIE_LEN 16 /* Per RFC7413 */
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#define TCP_FASTOPEN_PSK_LEN 16 /* Same as TCP_FASTOPEN_KEY_LEN */
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#endif /* __BSD_VISIBLE */
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/*
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* User-settable options (used with setsockopt). These are discrete
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* values and are not masked together. Some values appear to be
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* bitmasks for historical reasons.
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*/
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#define TCP_NODELAY 1 /* don't delay send to coalesce packets */
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#if __BSD_VISIBLE
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#define TCP_MAXSEG 2 /* set maximum segment size */
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#define TCP_NOPUSH 4 /* don't push last block of write */
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#define TCP_NOOPT 8 /* don't use TCP options */
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#define TCP_MD5SIG 16 /* use MD5 digests (RFC2385) */
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#define TCP_INFO 32 /* retrieve tcp_info structure */
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#define TCP_LOG 34 /* configure event logging for connection */
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#define TCP_LOGBUF 35 /* retrieve event log for connection */
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#define TCP_LOGID 36 /* configure log ID to correlate connections */
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#define TCP_LOGDUMP 37 /* dump connection log events to device */
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#define TCP_LOGDUMPID 38 /* dump events from connections with same ID to
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device */
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#define TCP_CONGESTION 64 /* get/set congestion control algorithm */
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#define TCP_CCALGOOPT 65 /* get/set cc algorithm specific options */
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#define TCP_DELACK 72 /* socket option for delayed ack */
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#define TCP_KEEPINIT 128 /* N, time to establish connection */
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#define TCP_KEEPIDLE 256 /* L,N,X start keeplives after this period */
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#define TCP_KEEPINTVL 512 /* L,N interval between keepalives */
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#define TCP_KEEPCNT 1024 /* L,N number of keepalives before close */
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#define TCP_FASTOPEN 1025 /* enable TFO / was created via TFO */
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#define TCP_PCAP_OUT 2048 /* number of output packets to keep */
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#define TCP_PCAP_IN 4096 /* number of input packets to keep */
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#define TCP_FUNCTION_BLK 8192 /* Set the tcp function pointers to the specified stack */
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/* Options for Rack and BBR */
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#define TCP_RACK_PROP 1051 /* RACK proportional rate reduction (bool) */
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#define TCP_RACK_TLP_REDUCE 1052 /* RACK TLP cwnd reduction (bool) */
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#define TCP_RACK_PACE_REDUCE 1053 /* RACK Pacing reduction factor (divisor) */
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#define TCP_RACK_PACE_MAX_SEG 1054 /* Max segments in a pace */
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#define TCP_RACK_PACE_ALWAYS 1055 /* Use the always pace method */
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#define TCP_RACK_PROP_RATE 1056 /* The proportional reduction rate */
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#define TCP_RACK_PRR_SENDALOT 1057 /* Allow PRR to send more than one seg */
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#define TCP_RACK_MIN_TO 1058 /* Minimum time between rack t-o's in ms */
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#define TCP_RACK_EARLY_RECOV 1059 /* Should recovery happen early (bool) */
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#define TCP_RACK_EARLY_SEG 1060 /* If early recovery max segments */
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#define TCP_RACK_REORD_THRESH 1061 /* RACK reorder threshold (shift amount) */
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#define TCP_RACK_REORD_FADE 1062 /* Does reordering fade after ms time */
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#define TCP_RACK_TLP_THRESH 1063 /* RACK TLP theshold i.e. srtt+(srtt/N) */
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#define TCP_RACK_PKT_DELAY 1064 /* RACK added ms i.e. rack-rtt + reord + N */
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#define TCP_RACK_TLP_INC_VAR 1065 /* Does TLP include rtt variance in t-o */
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#define TCP_RACK_SESS_CWV 1066 /* Enable RFC7611 cwnd validation on sess */
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#define TCP_BBR_IWINTSO 1067 /* Initial TSO window for BBRs first sends */
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#define TCP_BBR_RECFORCE 1068 /* Enter recovery force out a segment disregard pacer */
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#define TCP_BBR_STARTUP_PG 1069 /* Startup pacing gain */
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#define TCP_BBR_DRAIN_PG 1070 /* Drain pacing gain */
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#define TCP_BBR_RWND_IS_APP 1071 /* Rwnd limited is considered app limited */
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#define TCP_BBR_PROBE_RTT_INT 1072 /* How long in useconds between probe-rtt */
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#define TCP_BBR_ONE_RETRAN 1073 /* Is only one segment allowed out during retran */
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#define TCP_BBR_STARTUP_LOSS_EXIT 1074 /* Do we exit a loss during startup if not 20% incr */
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#define TCP_BBR_USE_LOWGAIN 1075 /* lower the gain in PROBE_BW enable */
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#define TCP_BBR_LOWGAIN_THRESH 1076 /* How many cycles do we stay in lowgain */
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#define TCP_BBR_LOWGAIN_HALF 1077 /* Do we halfstep lowgain down */
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#define TCP_BBR_LOWGAIN_FD 1078 /* Do we force a drain when lowgain in place */
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#define TCP_BBR_USEDEL_RATE 1079 /* Enable use of delivery rate for loss recovery */
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#define TCP_BBR_MIN_RTO 1080 /* Min RTO in milliseconds */
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#define TCP_BBR_MAX_RTO 1081 /* Max RTO in milliseconds */
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#define TCP_BBR_REC_OVER_HPTS 1082 /* Recovery override htps settings 0/1/3 */
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#define TCP_BBR_UNLIMITED 1083 /* Does BBR, in non-recovery not use cwnd */
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#define TCP_BBR_DRAIN_INC_EXTRA 1084 /* Does the 3/4 drain target include the extra gain */
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#define TCP_BBR_STARTUP_EXIT_EPOCH 1085 /* what epoch gets us out of startup */
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#define TCP_BBR_PACE_PER_SEC 1086
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#define TCP_BBR_PACE_DEL_TAR 1087
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#define TCP_BBR_PACE_SEG_MAX 1088
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#define TCP_BBR_PACE_SEG_MIN 1089
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#define TCP_BBR_PACE_CROSS 1090
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#define TCP_RACK_IDLE_REDUCE_HIGH 1092 /* Reduce the highest cwnd seen to IW on idle */
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#define TCP_RACK_IDLE_REDUCE_HIGH 1092 /* Reduce the highest cwnd seen to IW on idle */
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#define TCP_RACK_MIN_PACE 1093 /* Do we enforce rack min pace time */
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#define TCP_RACK_MIN_PACE_SEG 1094 /* If so what is the seg threshould */
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#define TCP_RACK_TLP_USE 1095
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#define TCP_BBR_ACK_COMP_ALG 1096 /* Not used */
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#define TCP_BBR_EXTRA_GAIN 1097
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#define TCP_BBR_RACK_RTT_USE 1098 /* what RTT should we use 0, 1, or 2? */
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#define TCP_BBR_RETRAN_WTSO 1099
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#define TCP_DATA_AFTER_CLOSE 1100
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#define TCP_BBR_PROBE_RTT_GAIN 1101
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#define TCP_BBR_PROBE_RTT_LEN 1102
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/* Start of reserved space for third-party user-settable options. */
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#define TCP_VENDOR SO_VENDOR
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#define TCP_CA_NAME_MAX 16 /* max congestion control name length */
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#define TCPI_OPT_TIMESTAMPS 0x01
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#define TCPI_OPT_SACK 0x02
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#define TCPI_OPT_WSCALE 0x04
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#define TCPI_OPT_ECN 0x08
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#define TCPI_OPT_TOE 0x10
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/* Maximum length of log ID. */
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#define TCP_LOG_ID_LEN 64
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/*
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* The TCP_INFO socket option comes from the Linux 2.6 TCP API, and permits
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* the caller to query certain information about the state of a TCP
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* connection. We provide an overlapping set of fields with the Linux
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* implementation, but since this is a fixed size structure, room has been
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* left for growth. In order to maximize potential future compatibility with
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* the Linux API, the same variable names and order have been adopted, and
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* padding left to make room for omitted fields in case they are added later.
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*
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* XXX: This is currently an unstable ABI/API, in that it is expected to
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* change.
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*/
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struct tcp_info {
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u_int8_t tcpi_state; /* TCP FSM state. */
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u_int8_t __tcpi_ca_state;
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u_int8_t __tcpi_retransmits;
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u_int8_t __tcpi_probes;
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u_int8_t __tcpi_backoff;
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u_int8_t tcpi_options; /* Options enabled on conn. */
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u_int8_t tcpi_snd_wscale:4, /* RFC1323 send shift value. */
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tcpi_rcv_wscale:4; /* RFC1323 recv shift value. */
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u_int32_t tcpi_rto; /* Retransmission timeout (usec). */
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u_int32_t __tcpi_ato;
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u_int32_t tcpi_snd_mss; /* Max segment size for send. */
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u_int32_t tcpi_rcv_mss; /* Max segment size for receive. */
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u_int32_t __tcpi_unacked;
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u_int32_t __tcpi_sacked;
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u_int32_t __tcpi_lost;
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u_int32_t __tcpi_retrans;
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u_int32_t __tcpi_fackets;
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/* Times; measurements in usecs. */
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u_int32_t __tcpi_last_data_sent;
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u_int32_t __tcpi_last_ack_sent; /* Also unimpl. on Linux? */
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u_int32_t tcpi_last_data_recv; /* Time since last recv data. */
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u_int32_t __tcpi_last_ack_recv;
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/* Metrics; variable units. */
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u_int32_t __tcpi_pmtu;
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u_int32_t __tcpi_rcv_ssthresh;
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u_int32_t tcpi_rtt; /* Smoothed RTT in usecs. */
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u_int32_t tcpi_rttvar; /* RTT variance in usecs. */
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u_int32_t tcpi_snd_ssthresh; /* Slow start threshold. */
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u_int32_t tcpi_snd_cwnd; /* Send congestion window. */
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u_int32_t __tcpi_advmss;
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u_int32_t __tcpi_reordering;
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u_int32_t __tcpi_rcv_rtt;
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u_int32_t tcpi_rcv_space; /* Advertised recv window. */
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/* FreeBSD extensions to tcp_info. */
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u_int32_t tcpi_snd_wnd; /* Advertised send window. */
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u_int32_t tcpi_snd_bwnd; /* No longer used. */
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u_int32_t tcpi_snd_nxt; /* Next egress seqno */
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u_int32_t tcpi_rcv_nxt; /* Next ingress seqno */
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u_int32_t tcpi_toe_tid; /* HWTID for TOE endpoints */
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u_int32_t tcpi_snd_rexmitpack; /* Retransmitted packets */
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u_int32_t tcpi_rcv_ooopack; /* Out-of-order packets */
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u_int32_t tcpi_snd_zerowin; /* Zero-sized windows sent */
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/* Padding to grow without breaking ABI. */
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u_int32_t __tcpi_pad[26]; /* Padding. */
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};
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/*
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* If this structure is provided when setting the TCP_FASTOPEN socket
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* option, and the enable member is non-zero, a subsequent connect will use
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* pre-shared key (PSK) mode using the provided key.
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*/
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struct tcp_fastopen {
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int enable;
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uint8_t psk[TCP_FASTOPEN_PSK_LEN];
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};
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#endif
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#define TCP_FUNCTION_NAME_LEN_MAX 32
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struct tcp_function_set {
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char function_set_name[TCP_FUNCTION_NAME_LEN_MAX];
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uint32_t pcbcnt;
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};
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#endif /* !_NETINET_TCP_H_ */
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