1 /* 2 * Copyright (c) 1982, 1986, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)tcp_var.h 8.3 (Berkeley) 4/10/94 34 * $Id: tcp_var.h,v 1.7 1995/02/14 02:35:19 wollman Exp $ 35 */ 36 37 #ifndef _NETINET_TCP_VAR_H_ 38 #define _NETINET_TCP_VAR_H_ 39 /* 40 * Kernel variables for tcp. 41 */ 42 43 /* 44 * Tcp control block, one per tcp; fields: 45 */ 46 struct tcpcb { 47 struct tcpiphdr *seg_next; /* sequencing queue */ 48 struct tcpiphdr *seg_prev; 49 short t_state; /* state of this connection */ 50 short t_timer[TCPT_NTIMERS]; /* tcp timers */ 51 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 52 short t_rxtcur; /* current retransmit value */ 53 short t_dupacks; /* consecutive dup acks recd */ 54 u_short t_maxseg; /* maximum segment size */ 55 u_short t_maxopd; /* mss plus options */ 56 char t_force; /* 1 if forcing out a byte */ 57 u_short t_flags; 58 #define TF_ACKNOW 0x0001 /* ack peer immediately */ 59 #define TF_DELACK 0x0002 /* ack, but try to delay it */ 60 #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ 61 #define TF_NOOPT 0x0008 /* don't use tcp options */ 62 #define TF_SENTFIN 0x0010 /* have sent FIN */ 63 #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ 64 #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ 65 #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ 66 #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ 67 #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ 68 #define TF_NEEDSYN 0x0400 /* send SYN (implicit state) */ 69 #define TF_NEEDFIN 0x0800 /* send FIN (implicit state) */ 70 #define TF_NOPUSH 0x1000 /* don't push */ 71 #define TF_REQ_CC 0x2000 /* have/will request CC */ 72 #define TF_RCVD_CC 0x4000 /* a CC was received in SYN */ 73 74 struct tcpiphdr *t_template; /* skeletal packet for transmit */ 75 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 76 /* 77 * The following fields are used as in the protocol specification. 78 * See RFC783, Dec. 1981, page 21. 79 */ 80 /* send sequence variables */ 81 tcp_seq snd_una; /* send unacknowledged */ 82 tcp_seq snd_nxt; /* send next */ 83 tcp_seq snd_up; /* send urgent pointer */ 84 tcp_seq snd_wl1; /* window update seg seq number */ 85 tcp_seq snd_wl2; /* window update seg ack number */ 86 tcp_seq iss; /* initial send sequence number */ 87 u_long snd_wnd; /* send window */ 88 /* receive sequence variables */ 89 u_long rcv_wnd; /* receive window */ 90 tcp_seq rcv_nxt; /* receive next */ 91 tcp_seq rcv_up; /* receive urgent pointer */ 92 tcp_seq irs; /* initial receive sequence number */ 93 /* 94 * Additional variables for this implementation. 95 */ 96 /* receive variables */ 97 tcp_seq rcv_adv; /* advertised window */ 98 /* retransmit variables */ 99 tcp_seq snd_max; /* highest sequence number sent; 100 * used to recognize retransmits 101 */ 102 /* congestion control (for slow start, source quench, retransmit after loss) */ 103 u_long snd_cwnd; /* congestion-controlled window */ 104 u_long snd_ssthresh; /* snd_cwnd size threshhold for 105 * for slow start exponential to 106 * linear switch 107 */ 108 /* 109 * transmit timing stuff. See below for scale of srtt and rttvar. 110 * "Variance" is actually smoothed difference. 111 */ 112 short t_idle; /* inactivity time */ 113 short t_rtt; /* round trip time */ 114 tcp_seq t_rtseq; /* sequence number being timed */ 115 short t_srtt; /* smoothed round-trip time */ 116 short t_rttvar; /* variance in round-trip time */ 117 u_short t_rttmin; /* minimum rtt allowed */ 118 u_long max_sndwnd; /* largest window peer has offered */ 119 120 /* out-of-band data */ 121 char t_oobflags; /* have some */ 122 char t_iobc; /* input character */ 123 #define TCPOOB_HAVEDATA 0x01 124 #define TCPOOB_HADDATA 0x02 125 short t_softerror; /* possible error not yet reported */ 126 127 /* RFC 1323 variables */ 128 u_char snd_scale; /* window scaling for send window */ 129 u_char rcv_scale; /* window scaling for recv window */ 130 u_char request_r_scale; /* pending window scaling */ 131 u_char requested_s_scale; 132 u_long ts_recent; /* timestamp echo data */ 133 u_long ts_recent_age; /* when last updated */ 134 tcp_seq last_ack_sent; 135 /* RFC 1644 variables */ 136 tcp_cc cc_send; /* send connection count */ 137 tcp_cc cc_recv; /* receive connection count */ 138 u_long t_duration; /* connection duration */ 139 140 /* TUBA stuff */ 141 caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */ 142 }; 143 144 /* 145 * Structure to hold TCP options that are only used during segment 146 * processing (in tcp_input), but not held in the tcpcb. 147 * It's basically used to reduce the number of parameters 148 * to tcp_dooptions. 149 */ 150 struct tcpopt { 151 u_long to_flag; /* which options are present */ 152 #define TOF_TS 0x0001 /* timestamp */ 153 #define TOF_CC 0x0002 /* CC and CCnew are exclusive */ 154 #define TOF_CCNEW 0x0004 155 #define TOF_CCECHO 0x0008 156 u_long to_tsval; 157 u_long to_tsecr; 158 tcp_cc to_cc; /* holds CC or CCnew */ 159 tcp_cc to_ccecho; 160 }; 161 162 /* 163 * The TAO cache entry which is stored in the protocol family specific 164 * portion of the route metrics. 165 */ 166 struct rmxp_tao { 167 tcp_cc tao_cc; /* latest CC in valid SYN */ 168 tcp_cc tao_ccsent; /* latest CC sent to peer */ 169 u_short tao_mssopt; /* peer's cached MSS */ 170 #ifdef notyet 171 u_short tao_flags; /* cache status flags */ 172 #define TAOF_DONT 0x0001 /* peer doesn't understand rfc1644 */ 173 #define TAOF_OK 0x0002 /* peer does understand rfc1644 */ 174 #define TAOF_UNDEF 0 /* we don't know yet */ 175 #endif /* notyet */ 176 }; 177 #define rmx_taop(r) ((struct rmxp_tao *)(r).rmx_filler) 178 179 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 180 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 181 182 /* 183 * The smoothed round-trip time and estimated variance 184 * are stored as fixed point numbers scaled by the values below. 185 * For convenience, these scales are also used in smoothing the average 186 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 187 * With these scales, srtt has 3 bits to the right of the binary point, 188 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the 189 * binary point, and is smoothed with an ALPHA of 0.75. 190 */ 191 #define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */ 192 #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ 193 #define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */ 194 #define TCP_RTTVAR_SHIFT 2 /* shift for rttvar; 2 bits */ 195 196 /* 197 * The initial retransmission should happen at rtt + 4 * rttvar. 198 * Because of the way we do the smoothing, srtt and rttvar 199 * will each average +1/2 tick of bias. When we compute 200 * the retransmit timer, we want 1/2 tick of rounding and 201 * 1 extra tick because of +-1/2 tick uncertainty in the 202 * firing of the timer. The bias will give us exactly the 203 * 1.5 tick we need. But, because the bias is 204 * statistical, we have to test that we don't drop below 205 * the minimum feasible timer (which is 2 ticks). 206 * This macro assumes that the value of TCP_RTTVAR_SCALE 207 * is the same as the multiplier for rttvar. 208 */ 209 #define TCP_REXMTVAL(tp) \ 210 (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) 211 212 /* XXX 213 * We want to avoid doing m_pullup on incoming packets but that 214 * means avoiding dtom on the tcp reassembly code. That in turn means 215 * keeping an mbuf pointer in the reassembly queue (since we might 216 * have a cluster). As a quick hack, the source & destination 217 * port numbers (which are no longer needed once we've located the 218 * tcpcb) are overlayed with an mbuf pointer. 219 */ 220 #define REASS_MBUF(ti) (*(struct mbuf **)&((ti)->ti_t)) 221 222 /* 223 * TCP statistics. 224 * Many of these should be kept per connection, 225 * but that's inconvenient at the moment. 226 */ 227 struct tcpstat { 228 u_long tcps_connattempt; /* connections initiated */ 229 u_long tcps_accepts; /* connections accepted */ 230 u_long tcps_connects; /* connections established */ 231 u_long tcps_drops; /* connections dropped */ 232 u_long tcps_conndrops; /* embryonic connections dropped */ 233 u_long tcps_closed; /* conn. closed (includes drops) */ 234 u_long tcps_segstimed; /* segs where we tried to get rtt */ 235 u_long tcps_rttupdated; /* times we succeeded */ 236 u_long tcps_delack; /* delayed acks sent */ 237 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 238 u_long tcps_rexmttimeo; /* retransmit timeouts */ 239 u_long tcps_persisttimeo; /* persist timeouts */ 240 u_long tcps_keeptimeo; /* keepalive timeouts */ 241 u_long tcps_keepprobe; /* keepalive probes sent */ 242 u_long tcps_keepdrops; /* connections dropped in keepalive */ 243 244 u_long tcps_sndtotal; /* total packets sent */ 245 u_long tcps_sndpack; /* data packets sent */ 246 u_long tcps_sndbyte; /* data bytes sent */ 247 u_long tcps_sndrexmitpack; /* data packets retransmitted */ 248 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */ 249 u_long tcps_sndacks; /* ack-only packets sent */ 250 u_long tcps_sndprobe; /* window probes sent */ 251 u_long tcps_sndurg; /* packets sent with URG only */ 252 u_long tcps_sndwinup; /* window update-only packets sent */ 253 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 254 255 u_long tcps_rcvtotal; /* total packets received */ 256 u_long tcps_rcvpack; /* packets received in sequence */ 257 u_long tcps_rcvbyte; /* bytes received in sequence */ 258 u_long tcps_rcvbadsum; /* packets received with ccksum errs */ 259 u_long tcps_rcvbadoff; /* packets received with bad offset */ 260 u_long tcps_rcvshort; /* packets received too short */ 261 u_long tcps_rcvduppack; /* duplicate-only packets received */ 262 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */ 263 u_long tcps_rcvpartduppack; /* packets with some duplicate data */ 264 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 265 u_long tcps_rcvoopack; /* out-of-order packets received */ 266 u_long tcps_rcvoobyte; /* out-of-order bytes received */ 267 u_long tcps_rcvpackafterwin; /* packets with data after window */ 268 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */ 269 u_long tcps_rcvafterclose; /* packets rcvd after "close" */ 270 u_long tcps_rcvwinprobe; /* rcvd window probe packets */ 271 u_long tcps_rcvdupack; /* rcvd duplicate acks */ 272 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 273 u_long tcps_rcvackpack; /* rcvd ack packets */ 274 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */ 275 u_long tcps_rcvwinupd; /* rcvd window update packets */ 276 u_long tcps_pawsdrop; /* segments dropped due to PAWS */ 277 u_long tcps_predack; /* times hdr predict ok for acks */ 278 u_long tcps_preddat; /* times hdr predict ok for data pkts */ 279 u_long tcps_pcbcachemiss; 280 }; 281 282 /* 283 * Names for TCP sysctl objects 284 */ 285 #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */ 286 #define TCPCTL_DO_RFC1644 2 /* use RFC-1644 extensions */ 287 #define TCPCTL_MSSDFLT 3 /* MSS default */ 288 #define TCPCTL_STATS 4 /* statistics (read-only) */ 289 #define TCPCTL_RTTDFLT 5 /* default RTT estimate */ 290 #define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */ 291 #define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */ 292 #define TCPCTL_SENDSPACE 8 /* send buffer space */ 293 #define TCPCTL_RECVSPACE 9 /* receive buffer space */ 294 #define TCPCTL_MAXID 10 295 296 #define TCPCTL_NAMES { \ 297 { 0, 0 }, \ 298 { "rfc1323", CTLTYPE_INT }, \ 299 { "rfc1644", CTLTYPE_INT }, \ 300 { "mssdflt", CTLTYPE_INT }, \ 301 { "stats", CTLTYPE_STRUCT }, \ 302 { "rttdflt", CTLTYPE_INT }, \ 303 { "keepidle", CTLTYPE_INT }, \ 304 { "keepintvl", CTLTYPE_INT }, \ 305 { "sendspace", CTLTYPE_INT }, \ 306 { "recvspace", CTLTYPE_INT }, \ 307 } 308 309 #ifdef KERNEL 310 extern struct inpcb tcb; /* head of queue of active tcpcb's */ 311 extern struct tcpstat tcpstat; /* tcp statistics */ 312 extern u_long tcp_now; /* for RFC 1323 timestamps */ 313 314 int tcp_attach __P((struct socket *)); 315 void tcp_canceltimers __P((struct tcpcb *)); 316 struct tcpcb * 317 tcp_close __P((struct tcpcb *)); 318 int tcp_connect __P((struct tcpcb *, struct mbuf *)); 319 void tcp_ctlinput __P((int, struct sockaddr *, struct ip *)); 320 int tcp_ctloutput __P((int, struct socket *, int, int, struct mbuf **)); 321 struct tcpcb * 322 tcp_disconnect __P((struct tcpcb *)); 323 struct tcpcb * 324 tcp_drop __P((struct tcpcb *, int)); 325 void tcp_dooptions __P((struct tcpcb *, 326 u_char *, int, struct tcpiphdr *, struct tcpopt *)); 327 void tcp_drain __P((void)); 328 void tcp_fasttimo __P((void)); 329 struct rmxp_tao * 330 tcp_gettaocache __P((struct inpcb *)); 331 void tcp_init __P((void)); 332 void tcp_input __P((struct mbuf *, int)); 333 void tcp_mss __P((struct tcpcb *, int)); 334 int tcp_mssopt __P((struct tcpcb *)); 335 struct tcpcb * 336 tcp_newtcpcb __P((struct inpcb *)); 337 void tcp_notify __P((struct inpcb *, int)); 338 int tcp_output __P((struct tcpcb *)); 339 void tcp_pulloutofband __P((struct socket *, 340 struct tcpiphdr *, struct mbuf *)); 341 void tcp_quench __P((struct inpcb *, int)); 342 int tcp_reass __P((struct tcpcb *, struct tcpiphdr *, struct mbuf *)); 343 void tcp_respond __P((struct tcpcb *, 344 struct tcpiphdr *, struct mbuf *, u_long, u_long, int)); 345 struct rtentry * 346 tcp_rtlookup __P((struct inpcb *)); 347 void tcp_setpersist __P((struct tcpcb *)); 348 void tcp_slowtimo __P((void)); 349 int tcp_sysctl __P((int *, u_int, void *, size_t *, void *, size_t)); 350 struct tcpiphdr * 351 tcp_template __P((struct tcpcb *)); 352 struct tcpcb * 353 tcp_timers __P((struct tcpcb *, int)); 354 void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int)); 355 struct tcpcb * 356 tcp_usrclosed __P((struct tcpcb *)); 357 int tcp_usrreq __P((struct socket *, 358 int, struct mbuf *, struct mbuf *, struct mbuf *)); 359 void tcp_xmit_timer __P((struct tcpcb *, int)); 360 #endif /* KERNEL */ 361 362 #endif /* _NETINET_TCP_VAR_H_ */ 363