| 1 | /* $Id: tcp_var.h 82968 2020-02-04 10:35:17Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * NAT - TCP (declarations).
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2006-2020 Oracle Corporation
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox Open Source Edition (OSE), as
|
|---|
| 10 | * available from http://www.virtualbox.org. This file is free software;
|
|---|
| 11 | * you can redistribute it and/or modify it under the terms of the GNU
|
|---|
| 12 | * General Public License (GPL) as published by the Free Software
|
|---|
| 13 | * Foundation, in version 2 as it comes in the "COPYING" file of the
|
|---|
| 14 | * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
|
|---|
| 15 | * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
|
|---|
| 16 | */
|
|---|
| 17 |
|
|---|
| 18 | /*
|
|---|
| 19 | * This code is based on:
|
|---|
| 20 | *
|
|---|
| 21 | * Copyright (c) 1982, 1986, 1993, 1994
|
|---|
| 22 | * The Regents of the University of California. All rights reserved.
|
|---|
| 23 | *
|
|---|
| 24 | * Redistribution and use in source and binary forms, with or without
|
|---|
| 25 | * modification, are permitted provided that the following conditions
|
|---|
| 26 | * are met:
|
|---|
| 27 | * 1. Redistributions of source code must retain the above copyright
|
|---|
| 28 | * notice, this list of conditions and the following disclaimer.
|
|---|
| 29 | * 2. Redistributions in binary form must reproduce the above copyright
|
|---|
| 30 | * notice, this list of conditions and the following disclaimer in the
|
|---|
| 31 | * documentation and/or other materials provided with the distribution.
|
|---|
| 32 | * 3. All advertising materials mentioning features or use of this software
|
|---|
| 33 | * must display the following acknowledgement:
|
|---|
| 34 | * This product includes software developed by the University of
|
|---|
| 35 | * California, Berkeley and its contributors.
|
|---|
| 36 | * 4. Neither the name of the University nor the names of its contributors
|
|---|
| 37 | * may be used to endorse or promote products derived from this software
|
|---|
| 38 | * without specific prior written permission.
|
|---|
| 39 | *
|
|---|
| 40 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|---|
| 41 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|---|
| 42 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|---|
| 43 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|---|
| 44 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|---|
| 45 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|---|
| 46 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|---|
| 47 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|---|
| 48 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|---|
| 49 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|---|
| 50 | * SUCH DAMAGE.
|
|---|
| 51 | *
|
|---|
| 52 | * @(#)tcp_var.h 8.3 (Berkeley) 4/10/94
|
|---|
| 53 | * tcp_var.h,v 1.3 1994/08/21 05:27:39 paul Exp
|
|---|
| 54 | */
|
|---|
| 55 |
|
|---|
| 56 | #ifndef _TCP_VAR_H_
|
|---|
| 57 | #define _TCP_VAR_H_
|
|---|
| 58 |
|
|---|
| 59 | #include "queue.h"
|
|---|
| 60 | #include "tcpip.h"
|
|---|
| 61 | #include "tcp_timer.h"
|
|---|
| 62 |
|
|---|
| 63 | /* TCP segment queue entry */
|
|---|
| 64 | struct tseg_qent
|
|---|
| 65 | {
|
|---|
| 66 | LIST_ENTRY(tseg_qent) tqe_q;
|
|---|
| 67 | int tqe_len; /* TCP segment data length */
|
|---|
| 68 | struct tcphdr *tqe_th; /* a pointer to tcp header */
|
|---|
| 69 | struct mbuf *tqe_m; /* mbuf contains packet */
|
|---|
| 70 | };
|
|---|
| 71 | LIST_HEAD(tsegqe_head, tseg_qent);
|
|---|
| 72 |
|
|---|
| 73 | /*
|
|---|
| 74 | * Tcp control block, one per tcp; fields:
|
|---|
| 75 | */
|
|---|
| 76 | struct tcpcb
|
|---|
| 77 | {
|
|---|
| 78 | LIST_ENTRY(tcpcb) t_list;
|
|---|
| 79 | struct tsegqe_head t_segq; /* segment reassembly queue */
|
|---|
| 80 | int t_segqlen; /* segment reassembly queue length */
|
|---|
| 81 | int16_t t_state; /* state of this connection */
|
|---|
| 82 | int16_t t_timer[TCPT_NTIMERS]; /* tcp timers */
|
|---|
| 83 | int16_t t_rxtshift; /* log(2) of rexmt exp. backoff */
|
|---|
| 84 | int16_t t_rxtcur; /* current retransmit value */
|
|---|
| 85 | int16_t t_dupacks; /* consecutive dup acks recd */
|
|---|
| 86 | uint16_t t_maxseg; /* maximum segment size */
|
|---|
| 87 | char t_force; /* 1 if forcing out a byte */
|
|---|
| 88 | uint16_t t_flags;
|
|---|
| 89 | #define TF_ACKNOW 0x0001 /* ack peer immediately */
|
|---|
| 90 | #define TF_DELACK 0x0002 /* ack, but try to delay it */
|
|---|
| 91 | #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */
|
|---|
| 92 | #define TF_NOOPT 0x0008 /* don't use tcp options */
|
|---|
| 93 | #define TF_SENTFIN 0x0010 /* have sent FIN */
|
|---|
| 94 | #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */
|
|---|
| 95 | #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */
|
|---|
| 96 | #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */
|
|---|
| 97 | #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */
|
|---|
| 98 | #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */
|
|---|
| 99 |
|
|---|
| 100 | /* Make it static for now */
|
|---|
| 101 | /* struct tcpiphdr *t_template; / * skeletal packet for transmit */
|
|---|
| 102 | struct tcpiphdr t_template;
|
|---|
| 103 |
|
|---|
| 104 | struct socket *t_socket; /* back pointer to socket */
|
|---|
| 105 | /*
|
|---|
| 106 | * The following fields are used as in the protocol specification.
|
|---|
| 107 | * See RFC783, Dec. 1981, page 21.
|
|---|
| 108 | */
|
|---|
| 109 | /* send sequence variables */
|
|---|
| 110 | tcp_seq snd_una; /* send unacknowledged */
|
|---|
| 111 | tcp_seq snd_nxt; /* send next */
|
|---|
| 112 | tcp_seq snd_up; /* send urgent pointer */
|
|---|
| 113 | tcp_seq snd_wl1; /* window update seg seq number */
|
|---|
| 114 | tcp_seq snd_wl2; /* window update seg ack number */
|
|---|
| 115 | tcp_seq iss; /* initial send sequence number */
|
|---|
| 116 | uint32_t snd_wnd; /* send window */
|
|---|
| 117 | /* receive sequence variables */
|
|---|
| 118 | uint32_t rcv_wnd; /* receive window */
|
|---|
| 119 | tcp_seq rcv_nxt; /* receive next */
|
|---|
| 120 | tcp_seq rcv_up; /* receive urgent pointer */
|
|---|
| 121 | tcp_seq irs; /* initial receive sequence number */
|
|---|
| 122 | /*
|
|---|
| 123 | * Additional variables for this implementation.
|
|---|
| 124 | */
|
|---|
| 125 | /* receive variables */
|
|---|
| 126 | tcp_seq rcv_adv; /* advertised window */
|
|---|
| 127 | /* retransmit variables */
|
|---|
| 128 | tcp_seq snd_max; /* highest sequence number sent;
|
|---|
| 129 | * used to recognize retransmits
|
|---|
| 130 | */
|
|---|
| 131 | /* congestion control (for slow start, source quench, retransmit after loss) */
|
|---|
| 132 | uint32_t snd_cwnd; /* congestion-controlled window */
|
|---|
| 133 | uint32_t snd_ssthresh; /* snd_cwnd size threshold for
|
|---|
| 134 | * for slow start exponential to
|
|---|
| 135 | * linear switch
|
|---|
| 136 | */
|
|---|
| 137 | /*
|
|---|
| 138 | * transmit timing stuff. See below for scale of srtt and rttvar.
|
|---|
| 139 | * "Variance" is actually smoothed difference.
|
|---|
| 140 | */
|
|---|
| 141 | int16_t t_idle; /* inactivity time */
|
|---|
| 142 | int16_t t_rtt; /* round trip time */
|
|---|
| 143 | tcp_seq t_rtseq; /* sequence number being timed */
|
|---|
| 144 | int16_t t_srtt; /* smoothed round-trip time */
|
|---|
| 145 | int16_t t_rttvar; /* variance in round-trip time */
|
|---|
| 146 | uint16_t t_rttmin; /* minimum rtt allowed */
|
|---|
| 147 | uint32_t max_sndwnd; /* largest window peer has offered */
|
|---|
| 148 |
|
|---|
| 149 | /* out-of-band data */
|
|---|
| 150 | char t_oobflags; /* have some */
|
|---|
| 151 | char t_iobc; /* input character */
|
|---|
| 152 | #define TCPOOB_HAVEDATA 0x01
|
|---|
| 153 | #define TCPOOB_HADDATA 0x02
|
|---|
| 154 | short t_softerror; /* possible error not yet reported */
|
|---|
| 155 |
|
|---|
| 156 | /* RFC 1323 variables */
|
|---|
| 157 | uint8_t snd_scale; /* window scaling for send window */
|
|---|
| 158 | uint8_t rcv_scale; /* window scaling for recv window */
|
|---|
| 159 | uint8_t request_r_scale; /* pending window scaling */
|
|---|
| 160 | uint8_t requested_s_scale;
|
|---|
| 161 | uint32_t ts_recent; /* timestamp echo data */
|
|---|
| 162 | uint32_t ts_recent_age; /* when last updated */
|
|---|
| 163 | tcp_seq last_ack_sent;
|
|---|
| 164 | };
|
|---|
| 165 |
|
|---|
| 166 | LIST_HEAD(tcpcbhead, tcpcb);
|
|---|
| 167 |
|
|---|
| 168 | #define sototcpcb(so) ((so)->so_tcpcb)
|
|---|
| 169 |
|
|---|
| 170 | /*
|
|---|
| 171 | * The smoothed round-trip time and estimated variance
|
|---|
| 172 | * are stored as fixed point numbers scaled by the values below.
|
|---|
| 173 | * For convenience, these scales are also used in smoothing the average
|
|---|
| 174 | * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
|
|---|
| 175 | * With these scales, srtt has 3 bits to the right of the binary point,
|
|---|
| 176 | * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
|
|---|
| 177 | * binary point, and is smoothed with an ALPHA of 0.75.
|
|---|
| 178 | */
|
|---|
| 179 | #define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */
|
|---|
| 180 | #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
|
|---|
| 181 | #define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */
|
|---|
| 182 | #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */
|
|---|
| 183 |
|
|---|
| 184 | /*
|
|---|
| 185 | * The initial retransmission should happen at rtt + 4 * rttvar.
|
|---|
| 186 | * Because of the way we do the smoothing, srtt and rttvar
|
|---|
| 187 | * will each average +1/2 tick of bias. When we compute
|
|---|
| 188 | * the retransmit timer, we want 1/2 tick of rounding and
|
|---|
| 189 | * 1 extra tick because of +-1/2 tick uncertainty in the
|
|---|
| 190 | * firing of the timer. The bias will give us exactly the
|
|---|
| 191 | * 1.5 tick we need. But, because the bias is
|
|---|
| 192 | * statistical, we have to test that we don't drop below
|
|---|
| 193 | * the minimum feasible timer (which is 2 ticks).
|
|---|
| 194 | * This macro assumes that the value of TCP_RTTVAR_SCALE
|
|---|
| 195 | * is the same as the multiplier for rttvar.
|
|---|
| 196 | */
|
|---|
| 197 | #define TCP_REXMTVAL(tp) \
|
|---|
| 198 | (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar)
|
|---|
| 199 |
|
|---|
| 200 | /*
|
|---|
| 201 | * TCP statistics.
|
|---|
| 202 | * Many of these should be kept per connection,
|
|---|
| 203 | * but that's inconvenient at the moment.
|
|---|
| 204 | */
|
|---|
| 205 | struct tcpstat_t
|
|---|
| 206 | {
|
|---|
| 207 | u_long tcps_connattempt; /* connections initiated */
|
|---|
| 208 | u_long tcps_accepts; /* connections accepted */
|
|---|
| 209 | u_long tcps_connects; /* connections established */
|
|---|
| 210 | u_long tcps_drops; /* connections dropped */
|
|---|
| 211 | u_long tcps_conndrops; /* embryonic connections dropped */
|
|---|
| 212 | u_long tcps_closed; /* conn. closed (includes drops) */
|
|---|
| 213 | u_long tcps_segstimed; /* segs where we tried to get rtt */
|
|---|
| 214 | u_long tcps_rttupdated; /* times we succeeded */
|
|---|
| 215 | u_long tcps_delack; /* delayed acks sent */
|
|---|
| 216 | u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
|
|---|
| 217 | u_long tcps_rexmttimeo; /* retransmit timeouts */
|
|---|
| 218 | u_long tcps_persisttimeo; /* persist timeouts */
|
|---|
| 219 | u_long tcps_keeptimeo; /* keepalive timeouts */
|
|---|
| 220 | u_long tcps_keepprobe; /* keepalive probes sent */
|
|---|
| 221 | u_long tcps_keepdrops; /* connections dropped in keepalive */
|
|---|
| 222 |
|
|---|
| 223 | u_long tcps_sndtotal; /* total packets sent */
|
|---|
| 224 | u_long tcps_sndpack; /* data packets sent */
|
|---|
| 225 | u_long tcps_sndbyte; /* data bytes sent */
|
|---|
| 226 | u_long tcps_sndrexmitpack; /* data packets retransmitted */
|
|---|
| 227 | u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
|
|---|
| 228 | u_long tcps_sndacks; /* ack-only packets sent */
|
|---|
| 229 | u_long tcps_sndprobe; /* window probes sent */
|
|---|
| 230 | u_long tcps_sndurg; /* packets sent with URG only */
|
|---|
| 231 | u_long tcps_sndwinup; /* window update-only packets sent */
|
|---|
| 232 | u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
|
|---|
| 233 |
|
|---|
| 234 | u_long tcps_rcvtotal; /* total packets received */
|
|---|
| 235 | u_long tcps_rcvpack; /* packets received in sequence */
|
|---|
| 236 | u_long tcps_rcvbyte; /* bytes received in sequence */
|
|---|
| 237 | u_long tcps_rcvbadsum; /* packets received with ccksum errs */
|
|---|
| 238 | u_long tcps_rcvbadoff; /* packets received with bad offset */
|
|---|
| 239 | /* u_long tcps_rcvshort; */ /* packets received too short */
|
|---|
| 240 | u_long tcps_rcvduppack; /* duplicate-only packets received */
|
|---|
| 241 | u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
|
|---|
| 242 | u_long tcps_rcvpartduppack; /* packets with some duplicate data */
|
|---|
| 243 | u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
|
|---|
| 244 | u_long tcps_rcvoopack; /* out-of-order packets received */
|
|---|
| 245 | u_long tcps_rcvoobyte; /* out-of-order bytes received */
|
|---|
| 246 | u_long tcps_rcvpackafterwin; /* packets with data after window */
|
|---|
| 247 | u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
|
|---|
| 248 | u_long tcps_rcvafterclose; /* packets rcvd after "close" */
|
|---|
| 249 | u_long tcps_rcvwinprobe; /* rcvd window probe packets */
|
|---|
| 250 | u_long tcps_rcvdupack; /* rcvd duplicate acks */
|
|---|
| 251 | u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
|
|---|
| 252 | u_long tcps_rcvackpack; /* rcvd ack packets */
|
|---|
| 253 | u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
|
|---|
| 254 | u_long tcps_rcvwinupd; /* rcvd window update packets */
|
|---|
| 255 | /* u_long tcps_pawsdrop; */ /* segments dropped due to PAWS */
|
|---|
| 256 | u_long tcps_predack; /* times hdr predict ok for acks */
|
|---|
| 257 | u_long tcps_preddat; /* times hdr predict ok for data pkts */
|
|---|
| 258 | u_long tcps_socachemiss; /* tcp_last_so misses */
|
|---|
| 259 | u_long tcps_didnuttin; /* Times tcp_output didn't do anything XXX */
|
|---|
| 260 | u_long tcps_rcvmemdrop;
|
|---|
| 261 | };
|
|---|
| 262 |
|
|---|
| 263 | #endif
|
|---|
