tcp_var.h revision 1ca4a6ab3f30cc1d00058a1a23e62bb267016ea1
/*
* Copyright (c) 1982, 1986, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* 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
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)tcp_var.h 8.3 (Berkeley) 4/10/94
* tcp_var.h,v 1.3 1994/08/21 05:27:39 paul Exp
*/
#ifndef _TCP_VAR_H_
#define _TCP_VAR_H_
#ifdef VBOX_WITH_BSD_TCP_REASS
#include "queue.h"
#endif /* VBOX_WITH_BSD_TCP_REASS */
#include "tcpip.h"
#include "tcp_timer.h"
#if SIZEOF_CHAR_P == 4
typedef struct tcpiphdr *tcpiphdrp_32;
#else
typedef u_int32_t tcpiphdrp_32;
#if defined(VBOX_WITH_BSD_TCP_REASS) && defined(VBOX_WITH_BSD_REASS)
#else /* VBOX_WITH_BSD_REASS && VBOX_WITH_BSD_TCP_REASS */
#endif /* !VBOX_WITH_BSD_REASS || !VBOX_WITH_BSD_TCP_REASS*/
#endif
#ifdef VBOX_WITH_BSD_TCP_REASS
/* TCP segment queue entry */
struct tseg_qent {
int tqe_len; /* TCP segment data length */
};
#endif
/*
* Tcp control block, one per tcp; fields:
*/
struct tcpcb {
#ifndef VBOX_WITH_BSD_TCP_REASS
#else /* VBOX_WITH_BSD_TCP_REASS */
int t_segqlen; /* segment reassembly queue length */
#endif /* VBOX_WITH_BSD_TCP_REASS */
short t_state; /* state of this connection */
short t_rxtshift; /* log(2) of rexmt exp. backoff */
short t_rxtcur; /* current retransmit value */
short t_dupacks; /* consecutive dup acks recd */
char t_force; /* 1 if forcing out a byte */
/* Make it static for now */
/* struct tcpiphdr *t_template; / * skeletal packet for transmit */
struct tcpiphdr t_template;
/*
* The following fields are used as in the protocol specification.
* See RFC783, Dec. 1981, page 21.
*/
/* send sequence variables */
/* receive sequence variables */
/*
* Additional variables for this implementation.
*/
/* receive variables */
/* retransmit variables */
* used to recognize retransmits
*/
/* congestion control (for slow start, source quench, retransmit after loss) */
* for slow start exponential to
* linear switch
*/
/*
* transmit timing stuff. See below for scale of srtt and rttvar.
* "Variance" is actually smoothed difference.
*/
short t_idle; /* inactivity time */
short t_rtt; /* round trip time */
short t_srtt; /* smoothed round-trip time */
short t_rttvar; /* variance in round-trip time */
/* out-of-band data */
char t_oobflags; /* have some */
char t_iobc; /* input character */
#define TCPOOB_HAVEDATA 0x01
#define TCPOOB_HADDATA 0x02
short t_softerror; /* possible error not yet reported */
/* RFC 1323 variables */
};
#ifdef VBOX_WITH_BSD_TCP_REASS
#endif /*VBOX_WITH_BSD_TCP_REASS*/
/*
* The smoothed round-trip time and estimated variance
* are stored as fixed point numbers scaled by the values below.
* For convenience, these scales are also used in smoothing the average
* (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
* With these scales, srtt has 3 bits to the right of the binary point,
* and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
* binary point, and is smoothed with an ALPHA of 0.75.
*/
/*
* The initial retransmission should happen at rtt + 4 * rttvar.
* Because of the way we do the smoothing, srtt and rttvar
* will each average +1/2 tick of bias. When we compute
* the retransmit timer, we want 1/2 tick of rounding and
* 1 extra tick because of +-1/2 tick uncertainty in the
* firing of the timer. The bias will give us exactly the
* 1.5 tick we need. But, because the bias is
* statistical, we have to test that we don't drop below
* the minimum feasible timer (which is 2 ticks).
* This macro assumes that the value of TCP_RTTVAR_SCALE
* is the same as the multiplier for rttvar.
*/
#define TCP_REXMTVAL(tp) \
/* XXX
* We want to avoid doing m_pullup on incoming packets but that
* means avoiding dtom on the tcp reassembly code. That in turn means
* keeping an mbuf pointer in the reassembly queue (since we might
* have a cluster). As a quick hack, the source & destination
* port numbers (which are no longer needed once we've located the
* tcpcb) are overlayed with an mbuf pointer.
*/
#if SIZEOF_CHAR_P == 4
/* VBox change which is too much bother to #ifdef */
#else
/* VBox change which is too much bother to #ifdef */
#endif
/*#define REASS_MBUF(ti) (*(mbufp_32 *)&((ti)->ti_t)) - replaced by REASS_MBUF_GET/SET */
/*
* TCP statistics.
* Many of these should be kept per connection,
* but that's inconvenient at the moment.
*/
struct tcpstat_t {
/* u_long tcps_rcvshort; */ /* packets received too short */
/* u_long tcps_pawsdrop; */ /* segments dropped due to PAWS */
#ifdef VBOX_WITH_BSD_TCP_REASS
#endif /* VBOX_WITH_BSD_TCP_REASS */
};
#endif