375 lines
15 KiB
C
375 lines
15 KiB
C
/*
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* Copyright (c) 1982, 1986, 1993, 1994, 1995
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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. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. 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_var.h 8.4 (Berkeley) 5/24/95
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* $Id$
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*/
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#ifndef _NETINET_TCP_VAR_H_
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#define _NETINET_TCP_VAR_H_
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/*
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* Kernel variables for tcp.
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*/
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/*
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* Tcp control block, one per tcp; fields:
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*/
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struct tcpcb {
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struct tcpiphdr *seg_next; /* sequencing queue */
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struct tcpiphdr *seg_prev;
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int t_state; /* state of this connection */
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int t_timer[TCPT_NTIMERS]; /* tcp timers */
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int t_rxtshift; /* log(2) of rexmt exp. backoff */
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int t_rxtcur; /* current retransmit value */
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int t_dupacks; /* consecutive dup acks recd */
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u_int t_maxseg; /* maximum segment size */
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u_int t_maxopd; /* mss plus options */
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int t_force; /* 1 if forcing out a byte */
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u_int t_flags;
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#define TF_ACKNOW 0x0001 /* ack peer immediately */
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#define TF_DELACK 0x0002 /* ack, but try to delay it */
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#define TF_NODELAY 0x0004 /* don't delay packets to coalesce */
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#define TF_NOOPT 0x0008 /* don't use tcp options */
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#define TF_SENTFIN 0x0010 /* have sent FIN */
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#define TF_REQ_SCALE 0x0020 /* have/will request window scaling */
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#define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */
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#define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */
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#define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */
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#define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */
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#define TF_NEEDSYN 0x0400 /* send SYN (implicit state) */
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#define TF_NEEDFIN 0x0800 /* send FIN (implicit state) */
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#define TF_NOPUSH 0x1000 /* don't push */
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#define TF_REQ_CC 0x2000 /* have/will request CC */
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#define TF_RCVD_CC 0x4000 /* a CC was received in SYN */
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#define TF_SENDCCNEW 0x8000 /* send CCnew instead of CC in SYN */
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struct tcpiphdr *t_template; /* skeletal packet for transmit */
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struct inpcb *t_inpcb; /* back pointer to internet pcb */
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/*
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* The following fields are used as in the protocol specification.
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* See RFC783, Dec. 1981, page 21.
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*/
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/* send sequence variables */
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tcp_seq snd_una; /* send unacknowledged */
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tcp_seq snd_nxt; /* send next */
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tcp_seq snd_up; /* send urgent pointer */
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tcp_seq snd_wl1; /* window update seg seq number */
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tcp_seq snd_wl2; /* window update seg ack number */
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tcp_seq iss; /* initial send sequence number */
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u_long snd_wnd; /* send window */
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/* receive sequence variables */
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u_long rcv_wnd; /* receive window */
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tcp_seq rcv_nxt; /* receive next */
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tcp_seq rcv_up; /* receive urgent pointer */
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tcp_seq irs; /* initial receive sequence number */
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/*
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* Additional variables for this implementation.
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*/
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/* receive variables */
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tcp_seq rcv_adv; /* advertised window */
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/* retransmit variables */
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tcp_seq snd_max; /* highest sequence number sent;
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* used to recognize retransmits
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*/
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/* congestion control (for slow start, source quench, retransmit after loss) */
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u_long snd_cwnd; /* congestion-controlled window */
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u_long snd_ssthresh; /* snd_cwnd size threshold for
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* for slow start exponential to
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* linear switch
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*/
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/*
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* transmit timing stuff. See below for scale of srtt and rttvar.
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* "Variance" is actually smoothed difference.
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*/
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u_int t_idle; /* inactivity time */
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int t_rtt; /* round trip time */
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tcp_seq t_rtseq; /* sequence number being timed */
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int t_srtt; /* smoothed round-trip time */
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int t_rttvar; /* variance in round-trip time */
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u_int t_rttmin; /* minimum rtt allowed */
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u_long max_sndwnd; /* largest window peer has offered */
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/* out-of-band data */
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char t_oobflags; /* have some */
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char t_iobc; /* input character */
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#define TCPOOB_HAVEDATA 0x01
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#define TCPOOB_HADDATA 0x02
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int t_softerror; /* possible error not yet reported */
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/* RFC 1323 variables */
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u_char snd_scale; /* window scaling for send window */
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u_char rcv_scale; /* window scaling for recv window */
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u_char request_r_scale; /* pending window scaling */
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u_char requested_s_scale;
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u_long ts_recent; /* timestamp echo data */
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u_long ts_recent_age; /* when last updated */
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tcp_seq last_ack_sent;
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/* RFC 1644 variables */
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tcp_cc cc_send; /* send connection count */
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tcp_cc cc_recv; /* receive connection count */
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u_long t_duration; /* connection duration */
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/* TUBA stuff */
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caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */
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/* More RTT stuff */
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u_long t_rttupdated; /* number of times rtt sampled */
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};
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/*
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* Structure to hold TCP options that are only used during segment
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* processing (in tcp_input), but not held in the tcpcb.
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* It's basically used to reduce the number of parameters
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* to tcp_dooptions.
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*/
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struct tcpopt {
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u_long to_flag; /* which options are present */
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#define TOF_TS 0x0001 /* timestamp */
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#define TOF_CC 0x0002 /* CC and CCnew are exclusive */
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#define TOF_CCNEW 0x0004
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#define TOF_CCECHO 0x0008
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u_long to_tsval;
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u_long to_tsecr;
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tcp_cc to_cc; /* holds CC or CCnew */
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tcp_cc to_ccecho;
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};
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/*
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* The TAO cache entry which is stored in the protocol family specific
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* portion of the route metrics.
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*/
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struct rmxp_tao {
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tcp_cc tao_cc; /* latest CC in valid SYN */
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tcp_cc tao_ccsent; /* latest CC sent to peer */
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u_short tao_mssopt; /* peer's cached MSS */
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#ifdef notyet
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u_short tao_flags; /* cache status flags */
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#define TAOF_DONT 0x0001 /* peer doesn't understand rfc1644 */
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#define TAOF_OK 0x0002 /* peer does understand rfc1644 */
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#define TAOF_UNDEF 0 /* we don't know yet */
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#endif /* notyet */
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};
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#define rmx_taop(r) ((struct rmxp_tao *)(r).rmx_filler)
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#define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
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#define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
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/*
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* The smoothed round-trip time and estimated variance
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* are stored as fixed point numbers scaled by the values below.
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* For convenience, these scales are also used in smoothing the average
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* (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
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* With these scales, srtt has 3 bits to the right of the binary point,
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* and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
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* binary point, and is smoothed with an ALPHA of 0.75.
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*/
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#define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */
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#define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */
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#define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */
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#define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */
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#define TCP_DELTA_SHIFT 2 /* see tcp_input.c */
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/*
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* The initial retransmission should happen at rtt + 4 * rttvar.
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* Because of the way we do the smoothing, srtt and rttvar
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* will each average +1/2 tick of bias. When we compute
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* the retransmit timer, we want 1/2 tick of rounding and
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* 1 extra tick because of +-1/2 tick uncertainty in the
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* firing of the timer. The bias will give us exactly the
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* 1.5 tick we need. But, because the bias is
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* statistical, we have to test that we don't drop below
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* the minimum feasible timer (which is 2 ticks).
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* This version of the macro adapted from a paper by Lawrence
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* Brakmo and Larry Peterson which outlines a problem caused
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* by insufficient precision in the original implementation,
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* which results in inappropriately large RTO values for very
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* fast networks.
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*/
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#define TCP_REXMTVAL(tp) \
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((((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \
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+ (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
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/* XXX
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* We want to avoid doing m_pullup on incoming packets but that
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* means avoiding dtom on the tcp reassembly code. That in turn means
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* keeping an mbuf pointer in the reassembly queue (since we might
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* have a cluster). As a quick hack, the source & destination
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* port numbers (which are no longer needed once we've located the
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* tcpcb) are overlayed with an mbuf pointer.
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*/
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#define REASS_MBUF(ti) (*(struct mbuf **)&((ti)->ti_t))
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/*
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* TCP statistics.
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* Many of these should be kept per connection,
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* but that's inconvenient at the moment.
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*/
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struct tcpstat {
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u_long tcps_connattempt; /* connections initiated */
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u_long tcps_accepts; /* connections accepted */
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u_long tcps_connects; /* connections established */
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u_long tcps_drops; /* connections dropped */
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u_long tcps_conndrops; /* embryonic connections dropped */
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u_long tcps_closed; /* conn. closed (includes drops) */
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u_long tcps_segstimed; /* segs where we tried to get rtt */
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u_long tcps_rttupdated; /* times we succeeded */
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u_long tcps_delack; /* delayed acks sent */
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u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
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u_long tcps_rexmttimeo; /* retransmit timeouts */
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u_long tcps_persisttimeo; /* persist timeouts */
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u_long tcps_keeptimeo; /* keepalive timeouts */
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u_long tcps_keepprobe; /* keepalive probes sent */
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u_long tcps_keepdrops; /* connections dropped in keepalive */
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u_long tcps_sndtotal; /* total packets sent */
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u_long tcps_sndpack; /* data packets sent */
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u_long tcps_sndbyte; /* data bytes sent */
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u_long tcps_sndrexmitpack; /* data packets retransmitted */
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u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
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u_long tcps_sndacks; /* ack-only packets sent */
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u_long tcps_sndprobe; /* window probes sent */
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u_long tcps_sndurg; /* packets sent with URG only */
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u_long tcps_sndwinup; /* window update-only packets sent */
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u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
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u_long tcps_rcvtotal; /* total packets received */
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u_long tcps_rcvpack; /* packets received in sequence */
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u_long tcps_rcvbyte; /* bytes received in sequence */
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u_long tcps_rcvbadsum; /* packets received with ccksum errs */
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u_long tcps_rcvbadoff; /* packets received with bad offset */
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u_long tcps_rcvshort; /* packets received too short */
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u_long tcps_rcvduppack; /* duplicate-only packets received */
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u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
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u_long tcps_rcvpartduppack; /* packets with some duplicate data */
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u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
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u_long tcps_rcvoopack; /* out-of-order packets received */
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u_long tcps_rcvoobyte; /* out-of-order bytes received */
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u_long tcps_rcvpackafterwin; /* packets with data after window */
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u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
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u_long tcps_rcvafterclose; /* packets rcvd after "close" */
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u_long tcps_rcvwinprobe; /* rcvd window probe packets */
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u_long tcps_rcvdupack; /* rcvd duplicate acks */
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u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
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u_long tcps_rcvackpack; /* rcvd ack packets */
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u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
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u_long tcps_rcvwinupd; /* rcvd window update packets */
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u_long tcps_pawsdrop; /* segments dropped due to PAWS */
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u_long tcps_predack; /* times hdr predict ok for acks */
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u_long tcps_preddat; /* times hdr predict ok for data pkts */
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u_long tcps_pcbcachemiss;
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u_long tcps_cachedrtt; /* times cached RTT in route updated */
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u_long tcps_cachedrttvar; /* times cached rttvar updated */
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u_long tcps_cachedssthresh; /* times cached ssthresh updated */
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u_long tcps_usedrtt; /* times RTT initialized from route */
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u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */
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u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/
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u_long tcps_persistdrop; /* timeout in persist state */
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u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
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u_long tcps_mturesent; /* resends due to MTU discovery */
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u_long tcps_listendrop; /* listen queue overflows */
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};
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/*
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* Names for TCP sysctl objects
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*/
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#define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */
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#define TCPCTL_DO_RFC1644 2 /* use RFC-1644 extensions */
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#define TCPCTL_MSSDFLT 3 /* MSS default */
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#define TCPCTL_STATS 4 /* statistics (read-only) */
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#define TCPCTL_RTTDFLT 5 /* default RTT estimate */
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#define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */
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#define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */
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#define TCPCTL_SENDSPACE 8 /* send buffer space */
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#define TCPCTL_RECVSPACE 9 /* receive buffer space */
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#define TCPCTL_KEEPINIT 10 /* receive buffer space */
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#define TCPCTL_MAXID 11
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#define TCPCTL_NAMES { \
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{ 0, 0 }, \
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{ "rfc1323", CTLTYPE_INT }, \
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{ "rfc1644", CTLTYPE_INT }, \
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{ "mssdflt", CTLTYPE_INT }, \
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{ "stats", CTLTYPE_STRUCT }, \
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{ "rttdflt", CTLTYPE_INT }, \
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{ "keepidle", CTLTYPE_INT }, \
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{ "keepintvl", CTLTYPE_INT }, \
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{ "sendspace", CTLTYPE_INT }, \
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{ "recvspace", CTLTYPE_INT }, \
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{ "keepinit", CTLTYPE_INT }, \
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}
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#ifdef KERNEL
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extern struct inpcbhead tcb; /* head of queue of active tcpcb's */
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extern struct inpcbinfo tcbinfo;
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extern struct tcpstat tcpstat; /* tcp statistics */
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extern int tcp_mssdflt; /* XXX */
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extern u_long tcp_now; /* for RFC 1323 timestamps */
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void tcp_canceltimers __P((struct tcpcb *));
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struct tcpcb *
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tcp_close __P((struct tcpcb *));
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void tcp_ctlinput __P((int, struct sockaddr *, void *));
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int tcp_ctloutput __P((int, struct socket *, int, int, struct mbuf **));
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struct tcpcb *
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tcp_drop __P((struct tcpcb *, int));
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void tcp_drain __P((void));
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void tcp_fasttimo __P((void));
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struct rmxp_tao *
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tcp_gettaocache __P((struct inpcb *));
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void tcp_init __P((void));
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void tcp_input __P((struct mbuf *, int));
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void tcp_mss __P((struct tcpcb *, int));
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int tcp_mssopt __P((struct tcpcb *));
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void tcp_mtudisc __P((struct inpcb *, int));
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struct tcpcb *
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tcp_newtcpcb __P((struct inpcb *));
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int tcp_output __P((struct tcpcb *));
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void tcp_quench __P((struct inpcb *, int));
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void tcp_respond __P((struct tcpcb *,
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struct tcpiphdr *, struct mbuf *, u_long, u_long, int));
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struct rtentry *
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tcp_rtlookup __P((struct inpcb *));
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void tcp_setpersist __P((struct tcpcb *));
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void tcp_slowtimo __P((void));
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struct tcpiphdr *
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tcp_template __P((struct tcpcb *));
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struct tcpcb *
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tcp_timers __P((struct tcpcb *, int));
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void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int));
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extern struct pr_usrreqs tcp_usrreqs;
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extern u_long tcp_sendspace;
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extern u_long tcp_recvspace;
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#endif /* KERNEL */
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#endif /* _NETINET_TCP_VAR_H_ */
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