tcp_var.h revision 1.19
1 /* $NetBSD: tcp_var.h,v 1.19 1996/12/10 18:20:26 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)tcp_var.h 8.3 (Berkeley) 4/10/94 36 */ 37 38 /* 39 * Kernel variables for tcp. 40 */ 41 42 /* 43 * Tcp control block, one per tcp; fields: 44 */ 45 struct tcpcb { 46 struct ipqehead segq; /* sequencing queue */ 47 short t_state; /* state of this connection */ 48 short t_timer[TCPT_NTIMERS]; /* tcp timers */ 49 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 50 short t_rxtcur; /* current retransmit value */ 51 short t_dupacks; /* consecutive dup acks recd */ 52 u_short t_maxseg; /* maximum segment size */ 53 char t_force; /* 1 if forcing out a byte */ 54 u_short t_flags; 55 #define TF_ACKNOW 0x0001 /* ack peer immediately */ 56 #define TF_DELACK 0x0002 /* ack, but try to delay it */ 57 #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ 58 #define TF_NOOPT 0x0008 /* don't use tcp options */ 59 #define TF_SENTFIN 0x0010 /* have sent FIN */ 60 #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ 61 #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ 62 #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ 63 #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ 64 #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ 65 66 struct tcpiphdr *t_template; /* skeletal packet for transmit */ 67 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 68 /* 69 * The following fields are used as in the protocol specification. 70 * See RFC783, Dec. 1981, page 21. 71 */ 72 /* send sequence variables */ 73 tcp_seq snd_una; /* send unacknowledged */ 74 tcp_seq snd_nxt; /* send next */ 75 tcp_seq snd_up; /* send urgent pointer */ 76 tcp_seq snd_wl1; /* window update seg seq number */ 77 tcp_seq snd_wl2; /* window update seg ack number */ 78 tcp_seq iss; /* initial send sequence number */ 79 u_long snd_wnd; /* send window */ 80 /* receive sequence variables */ 81 u_long rcv_wnd; /* receive window */ 82 tcp_seq rcv_nxt; /* receive next */ 83 tcp_seq rcv_up; /* receive urgent pointer */ 84 tcp_seq irs; /* initial receive sequence number */ 85 /* 86 * Additional variables for this implementation. 87 */ 88 /* receive variables */ 89 tcp_seq rcv_adv; /* advertised window */ 90 /* retransmit variables */ 91 tcp_seq snd_max; /* highest sequence number sent; 92 * used to recognize retransmits 93 */ 94 /* congestion control (for slow start, source quench, retransmit after loss) */ 95 u_long snd_cwnd; /* congestion-controlled window */ 96 u_long snd_ssthresh; /* snd_cwnd size threshhold for 97 * for slow start exponential to 98 * linear switch 99 */ 100 /* 101 * transmit timing stuff. See below for scale of srtt and rttvar. 102 * "Variance" is actually smoothed difference. 103 */ 104 short t_idle; /* inactivity time */ 105 short t_rtt; /* round trip time */ 106 tcp_seq t_rtseq; /* sequence number being timed */ 107 short t_srtt; /* smoothed round-trip time */ 108 short t_rttvar; /* variance in round-trip time */ 109 u_short t_rttmin; /* minimum rtt allowed */ 110 u_long max_sndwnd; /* largest window peer has offered */ 111 112 /* out-of-band data */ 113 char t_oobflags; /* have some */ 114 char t_iobc; /* input character */ 115 #define TCPOOB_HAVEDATA 0x01 116 #define TCPOOB_HADDATA 0x02 117 short t_softerror; /* possible error not yet reported */ 118 119 /* RFC 1323 variables */ 120 u_char snd_scale; /* window scaling for send window */ 121 u_char rcv_scale; /* window scaling for recv window */ 122 u_char request_r_scale; /* pending window scaling */ 123 u_char requested_s_scale; 124 u_int32_t ts_recent; /* timestamp echo data */ 125 u_int32_t ts_recent_age; /* when last updated */ 126 tcp_seq last_ack_sent; 127 128 /* TUBA stuff */ 129 caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */ 130 }; 131 132 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 133 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 134 135 /* 136 * The smoothed round-trip time and estimated variance 137 * are stored as fixed point numbers scaled by the values below. 138 * For convenience, these scales are also used in smoothing the average 139 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 140 * With these scales, srtt has 3 bits to the right of the binary point, 141 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the 142 * binary point, and is smoothed with an ALPHA of 0.75. 143 */ 144 #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ 145 #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */ 146 147 /* 148 * The initial retransmission should happen at rtt + 4 * rttvar. 149 * Because of the way we do the smoothing, srtt and rttvar 150 * will each average +1/2 tick of bias. When we compute 151 * the retransmit timer, we want 1/2 tick of rounding and 152 * 1 extra tick because of +-1/2 tick uncertainty in the 153 * firing of the timer. The bias will give us exactly the 154 * 1.5 tick we need. But, because the bias is 155 * statistical, we have to test that we don't drop below 156 * the minimum feasible timer (which is 2 ticks). 157 * This macro assumes that the value of 1<<TCP_RTTVAR_SHIFT 158 * is the same as the multiplier for rttvar. 159 */ 160 #define TCP_REXMTVAL(tp) \ 161 ((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2) 162 163 /* 164 * TCP statistics. 165 * Many of these should be kept per connection, 166 * but that's inconvenient at the moment. 167 */ 168 struct tcpstat { 169 u_long tcps_connattempt; /* connections initiated */ 170 u_long tcps_accepts; /* connections accepted */ 171 u_long tcps_connects; /* connections established */ 172 u_long tcps_drops; /* connections dropped */ 173 u_long tcps_conndrops; /* embryonic connections dropped */ 174 u_long tcps_closed; /* conn. closed (includes drops) */ 175 u_long tcps_segstimed; /* segs where we tried to get rtt */ 176 u_long tcps_rttupdated; /* times we succeeded */ 177 u_long tcps_delack; /* delayed acks sent */ 178 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 179 u_long tcps_rexmttimeo; /* retransmit timeouts */ 180 u_long tcps_persisttimeo; /* persist timeouts */ 181 u_long tcps_keeptimeo; /* keepalive timeouts */ 182 u_long tcps_keepprobe; /* keepalive probes sent */ 183 u_long tcps_keepdrops; /* connections dropped in keepalive */ 184 185 u_long tcps_sndtotal; /* total packets sent */ 186 u_long tcps_sndpack; /* data packets sent */ 187 u_long tcps_sndbyte; /* data bytes sent */ 188 u_long tcps_sndrexmitpack; /* data packets retransmitted */ 189 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */ 190 u_long tcps_sndacks; /* ack-only packets sent */ 191 u_long tcps_sndprobe; /* window probes sent */ 192 u_long tcps_sndurg; /* packets sent with URG only */ 193 u_long tcps_sndwinup; /* window update-only packets sent */ 194 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 195 196 u_long tcps_rcvtotal; /* total packets received */ 197 u_long tcps_rcvpack; /* packets received in sequence */ 198 u_long tcps_rcvbyte; /* bytes received in sequence */ 199 u_long tcps_rcvbadsum; /* packets received with ccksum errs */ 200 u_long tcps_rcvbadoff; /* packets received with bad offset */ 201 u_long tcps_rcvmemdrop; /* packets dropped for lack of memory */ 202 u_long tcps_rcvshort; /* packets received too short */ 203 u_long tcps_rcvduppack; /* duplicate-only packets received */ 204 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */ 205 u_long tcps_rcvpartduppack; /* packets with some duplicate data */ 206 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 207 u_long tcps_rcvoopack; /* out-of-order packets received */ 208 u_long tcps_rcvoobyte; /* out-of-order bytes received */ 209 u_long tcps_rcvpackafterwin; /* packets with data after window */ 210 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */ 211 u_long tcps_rcvafterclose; /* packets rcvd after "close" */ 212 u_long tcps_rcvwinprobe; /* rcvd window probe packets */ 213 u_long tcps_rcvdupack; /* rcvd duplicate acks */ 214 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 215 u_long tcps_rcvackpack; /* rcvd ack packets */ 216 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */ 217 u_long tcps_rcvwinupd; /* rcvd window update packets */ 218 u_long tcps_pawsdrop; /* segments dropped due to PAWS */ 219 u_long tcps_predack; /* times hdr predict ok for acks */ 220 u_long tcps_preddat; /* times hdr predict ok for data pkts */ 221 222 u_long tcps_pcbhashmiss; /* input packets missing pcb hash */ 223 u_long tcps_noport; /* no socket on port */ 224 }; 225 226 /* 227 * Names for TCP sysctl objects. 228 */ 229 /* enable/disable RFC1323 timestamps/scaling */ 230 #define TCPCTL_RFC1323 1 231 #define TCPCTL_MAXID 2 232 233 #define TCPCTL_NAMES { \ 234 { 0, 0 }, \ 235 { "rfc1323", CTLTYPE_INT }, \ 236 } 237 238 #ifdef _KERNEL 239 struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 240 struct tcpstat tcpstat; /* tcp statistics */ 241 u_int32_t tcp_now; /* for RFC 1323 timestamps */ 242 extern int tcp_do_rfc1323; /* enabled/disabled? */ 243 244 int tcp_attach __P((struct socket *)); 245 void tcp_canceltimers __P((struct tcpcb *)); 246 struct tcpcb * 247 tcp_close __P((struct tcpcb *)); 248 void *tcp_ctlinput __P((int, struct sockaddr *, void *)); 249 int tcp_ctloutput __P((int, struct socket *, int, int, struct mbuf **)); 250 struct tcpcb * 251 tcp_disconnect __P((struct tcpcb *)); 252 struct tcpcb * 253 tcp_drop __P((struct tcpcb *, int)); 254 void tcp_dooptions __P((struct tcpcb *, 255 u_char *, int, struct tcpiphdr *, int *, u_int32_t *, u_int32_t *)); 256 void tcp_drain __P((void)); 257 void tcp_fasttimo __P((void)); 258 void tcp_init __P((void)); 259 void tcp_input __P((struct mbuf *, ...)); 260 int tcp_mss __P((struct tcpcb *, u_int)); 261 struct tcpcb * 262 tcp_newtcpcb __P((struct inpcb *)); 263 void tcp_notify __P((struct inpcb *, int)); 264 int tcp_output __P((struct tcpcb *)); 265 void tcp_pulloutofband __P((struct socket *, 266 struct tcpiphdr *, struct mbuf *)); 267 void tcp_quench __P((struct inpcb *, int)); 268 int tcp_reass __P((struct tcpcb *, struct tcpiphdr *, struct mbuf *)); 269 void tcp_respond __P((struct tcpcb *, 270 struct tcpiphdr *, struct mbuf *, tcp_seq, tcp_seq, int)); 271 void tcp_setpersist __P((struct tcpcb *)); 272 void tcp_slowtimo __P((void)); 273 struct tcpiphdr * 274 tcp_template __P((struct tcpcb *)); 275 struct tcpcb * 276 tcp_timers __P((struct tcpcb *, int)); 277 void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int)); 278 struct tcpcb * 279 tcp_usrclosed __P((struct tcpcb *)); 280 int tcp_sysctl __P((int *, u_int, void *, size_t *, void *, size_t)); 281 int tcp_usrreq __P((struct socket *, 282 int, struct mbuf *, struct mbuf *, struct mbuf *, struct proc *)); 283 void tcp_xmit_timer __P((struct tcpcb *, int)); 284 #endif 285
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