1 /* 2 * Copyright (c) 1982, 1986, 1993, 1994, 1995 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 8.4 (Berkeley) 5/24/95 34 * $Id$ 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 int t_state; /* state of this connection */ 50 int t_timer[TCPT_NTIMERS]; /* tcp timers */ 51 int t_rxtshift; /* log(2) of rexmt exp. backoff */ 52 int t_rxtcur; /* current retransmit value */ 53 int t_dupacks; /* consecutive dup acks recd */ 54 u_int t_maxseg; /* maximum segment size */ 55 u_int t_maxopd; /* mss plus options */ 56 int t_force; /* 1 if forcing out a byte */ 57 u_int 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 #define TF_SENDCCNEW 0x8000 /* send CCnew instead of CC in SYN */ 74 75 struct tcpiphdr *t_template; /* skeletal packet for transmit */ 76 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 77 /* 78 * The following fields are used as in the protocol specification. 79 * See RFC783, Dec. 1981, page 21. 80 */ 81 /* send sequence variables */ 82 tcp_seq snd_una; /* send unacknowledged */ 83 tcp_seq snd_nxt; /* send next */ 84 tcp_seq snd_up; /* send urgent pointer */ 85 tcp_seq snd_wl1; /* window update seg seq number */ 86 tcp_seq snd_wl2; /* window update seg ack number */ 87 tcp_seq iss; /* initial send sequence number */ 88 u_long snd_wnd; /* send window */ 89 /* receive sequence variables */ 90 u_long rcv_wnd; /* receive window */ 91 tcp_seq rcv_nxt; /* receive next */ 92 tcp_seq rcv_up; /* receive urgent pointer */ 93 tcp_seq irs; /* initial receive sequence number */ 94 /* 95 * Additional variables for this implementation. 96 */ 97 /* receive variables */ 98 tcp_seq rcv_adv; /* advertised window */ 99 /* retransmit variables */ 100 tcp_seq snd_max; /* highest sequence number sent; 101 * used to recognize retransmits 102 */ 103 /* congestion control (for slow start, source quench, retransmit after loss) */ 104 u_long snd_cwnd; /* congestion-controlled window */ 105 u_long snd_ssthresh; /* snd_cwnd size threshold for 106 * for slow start exponential to 107 * linear switch 108 */ 109 /* 110 * transmit timing stuff. See below for scale of srtt and rttvar. 111 * "Variance" is actually smoothed difference. 112 */ 113 u_int t_idle; /* inactivity time */ 114 int t_rtt; /* round trip time */ 115 tcp_seq t_rtseq; /* sequence number being timed */ 116 int t_srtt; /* smoothed round-trip time */ 117 int t_rttvar; /* variance in round-trip time */ 118 u_int t_rttmin; /* minimum rtt allowed */ 119 u_long max_sndwnd; /* largest window peer has offered */ 120 121 /* out-of-band data */ 122 char t_oobflags; /* have some */ 123 char t_iobc; /* input character */ 124 #define TCPOOB_HAVEDATA 0x01 125 #define TCPOOB_HADDATA 0x02 126 int t_softerror; /* possible error not yet reported */ 127 128 /* RFC 1323 variables */ 129 u_char snd_scale; /* window scaling for send window */ 130 u_char rcv_scale; /* window scaling for recv window */ 131 u_char request_r_scale; /* pending window scaling */ 132 u_char requested_s_scale; 133 u_long ts_recent; /* timestamp echo data */ 134 u_long ts_recent_age; /* when last updated */ 135 tcp_seq last_ack_sent; 136 /* RFC 1644 variables */ 137 tcp_cc cc_send; /* send connection count */ 138 tcp_cc cc_recv; /* receive connection count */ 139 u_long t_duration; /* connection duration */ 140 141 /* TUBA stuff */ 142 caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */ 143 /* More RTT stuff */ 144 u_long t_rttupdated; /* number of times rtt sampled */ 145 }; 146 147 /* 148 * Structure to hold TCP options that are only used during segment 149 * processing (in tcp_input), but not held in the tcpcb. 150 * It's basically used to reduce the number of parameters 151 * to tcp_dooptions. 152 */ 153 struct tcpopt { 154 u_long to_flag; /* which options are present */ 155 #define TOF_TS 0x0001 /* timestamp */ 156 #define TOF_CC 0x0002 /* CC and CCnew are exclusive */ 157 #define TOF_CCNEW 0x0004 158 #define TOF_CCECHO 0x0008 159 u_long to_tsval; 160 u_long to_tsecr; 161 tcp_cc to_cc; /* holds CC or CCnew */ 162 tcp_cc to_ccecho; 163 }; 164 165 /* 166 * The TAO cache entry which is stored in the protocol family specific 167 * portion of the route metrics. 168 */ 169 struct rmxp_tao { 170 tcp_cc tao_cc; /* latest CC in valid SYN */ 171 tcp_cc tao_ccsent; /* latest CC sent to peer */ 172 u_short tao_mssopt; /* peer's cached MSS */ 173 #ifdef notyet 174 u_short tao_flags; /* cache status flags */ 175 #define TAOF_DONT 0x0001 /* peer doesn't understand rfc1644 */ 176 #define TAOF_OK 0x0002 /* peer does understand rfc1644 */ 177 #define TAOF_UNDEF 0 /* we don't know yet */ 178 #endif /* notyet */ 179 }; 180 #define rmx_taop(r) ((struct rmxp_tao *)(r).rmx_filler) 181 182 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 183 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 184 185 /* 186 * The smoothed round-trip time and estimated variance 187 * are stored as fixed point numbers scaled by the values below. 188 * For convenience, these scales are also used in smoothing the average 189 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 190 * With these scales, srtt has 3 bits to the right of the binary point, 191 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the 192 * binary point, and is smoothed with an ALPHA of 0.75. 193 */ 194 #define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */ 195 #define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */ 196 #define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */ 197 #define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */ 198 #define TCP_DELTA_SHIFT 2 /* see tcp_input.c */ 199 200 /* 201 * The initial retransmission should happen at rtt + 4 * rttvar. 202 * Because of the way we do the smoothing, srtt and rttvar 203 * will each average +1/2 tick of bias. When we compute 204 * the retransmit timer, we want 1/2 tick of rounding and 205 * 1 extra tick because of +-1/2 tick uncertainty in the 206 * firing of the timer. The bias will give us exactly the 207 * 1.5 tick we need. But, because the bias is 208 * statistical, we have to test that we don't drop below 209 * the minimum feasible timer (which is 2 ticks). 210 * This version of the macro adapted from a paper by Lawrence 211 * Brakmo and Larry Peterson which outlines a problem caused 212 * by insufficient precision in the original implementation, 213 * which results in inappropriately large RTO values for very 214 * fast networks. 215 */ 216 #define TCP_REXMTVAL(tp) \ 217 ((((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \ 218 + (tp)->t_rttvar) >> TCP_DELTA_SHIFT) 219 220 /* XXX 221 * We want to avoid doing m_pullup on incoming packets but that 222 * means avoiding dtom on the tcp reassembly code. That in turn means 223 * keeping an mbuf pointer in the reassembly queue (since we might 224 * have a cluster). As a quick hack, the source & destination 225 * port numbers (which are no longer needed once we've located the 226 * tcpcb) are overlayed with an mbuf pointer. 227 */ 228 #define REASS_MBUF(ti) (*(struct mbuf **)&((ti)->ti_t)) 229 230 /* 231 * TCP statistics. 232 * Many of these should be kept per connection, 233 * but that's inconvenient at the moment. 234 */ 235 struct tcpstat { 236 u_long tcps_connattempt; /* connections initiated */ 237 u_long tcps_accepts; /* connections accepted */ 238 u_long tcps_connects; /* connections established */ 239 u_long tcps_drops; /* connections dropped */ 240 u_long tcps_conndrops; /* embryonic connections dropped */ 241 u_long tcps_closed; /* conn. closed (includes drops) */ 242 u_long tcps_segstimed; /* segs where we tried to get rtt */ 243 u_long tcps_rttupdated; /* times we succeeded */ 244 u_long tcps_delack; /* delayed acks sent */ 245 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 246 u_long tcps_rexmttimeo; /* retransmit timeouts */ 247 u_long tcps_persisttimeo; /* persist timeouts */ 248 u_long tcps_keeptimeo; /* keepalive timeouts */ 249 u_long tcps_keepprobe; /* keepalive probes sent */ 250 u_long tcps_keepdrops; /* connections dropped in keepalive */ 251 252 u_long tcps_sndtotal; /* total packets sent */ 253 u_long tcps_sndpack; /* data packets sent */ 254 u_long tcps_sndbyte; /* data bytes sent */ 255 u_long tcps_sndrexmitpack; /* data packets retransmitted */ 256 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */ 257 u_long tcps_sndacks; /* ack-only packets sent */ 258 u_long tcps_sndprobe; /* window probes sent */ 259 u_long tcps_sndurg; /* packets sent with URG only */ 260 u_long tcps_sndwinup; /* window update-only packets sent */ 261 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 262 263 u_long tcps_rcvtotal; /* total packets received */ 264 u_long tcps_rcvpack; /* packets received in sequence */ 265 u_long tcps_rcvbyte; /* bytes received in sequence */ 266 u_long tcps_rcvbadsum; /* packets received with ccksum errs */ 267 u_long tcps_rcvbadoff; /* packets received with bad offset */ 268 u_long tcps_rcvshort; /* packets received too short */ 269 u_long tcps_rcvduppack; /* duplicate-only packets received */ 270 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */ 271 u_long tcps_rcvpartduppack; /* packets with some duplicate data */ 272 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 273 u_long tcps_rcvoopack; /* out-of-order packets received */ 274 u_long tcps_rcvoobyte; /* out-of-order bytes received */ 275 u_long tcps_rcvpackafterwin; /* packets with data after window */ 276 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */ 277 u_long tcps_rcvafterclose; /* packets rcvd after "close" */ 278 u_long tcps_rcvwinprobe; /* rcvd window probe packets */ 279 u_long tcps_rcvdupack; /* rcvd duplicate acks */ 280 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 281 u_long tcps_rcvackpack; /* rcvd ack packets */ 282 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */ 283 u_long tcps_rcvwinupd; /* rcvd window update packets */ 284 u_long tcps_pawsdrop; /* segments dropped due to PAWS */ 285 u_long tcps_predack; /* times hdr predict ok for acks */ 286 u_long tcps_preddat; /* times hdr predict ok for data pkts */ 287 u_long tcps_pcbcachemiss; 288 u_long tcps_cachedrtt; /* times cached RTT in route updated */ 289 u_long tcps_cachedrttvar; /* times cached rttvar updated */ 290 u_long tcps_cachedssthresh; /* times cached ssthresh updated */ 291 u_long tcps_usedrtt; /* times RTT initialized from route */ 292 u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */ 293 u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/ 294 u_long tcps_persistdrop; /* timeout in persist state */ 295 u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */ 296 u_long tcps_mturesent; /* resends due to MTU discovery */ 297 u_long tcps_listendrop; /* listen queue overflows */ 298 }; 299 300 /* 301 * Names for TCP sysctl objects 302 */ 303 #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */ 304 #define TCPCTL_DO_RFC1644 2 /* use RFC-1644 extensions */ 305 #define TCPCTL_MSSDFLT 3 /* MSS default */ 306 #define TCPCTL_STATS 4 /* statistics (read-only) */ 307 #define TCPCTL_RTTDFLT 5 /* default RTT estimate */ 308 #define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */ 309 #define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */ 310 #define TCPCTL_SENDSPACE 8 /* send buffer space */ 311 #define TCPCTL_RECVSPACE 9 /* receive buffer space */ 312 #define TCPCTL_KEEPINIT 10 /* receive buffer space */ 313 #define TCPCTL_MAXID 11 314 315 #define TCPCTL_NAMES { \ 316 { 0, 0 }, \ 317 { "rfc1323", CTLTYPE_INT }, \ 318 { "rfc1644", CTLTYPE_INT }, \ 319 { "mssdflt", CTLTYPE_INT }, \ 320 { "stats", CTLTYPE_STRUCT }, \ 321 { "rttdflt", CTLTYPE_INT }, \ 322 { "keepidle", CTLTYPE_INT }, \ 323 { "keepintvl", CTLTYPE_INT }, \ 324 { "sendspace", CTLTYPE_INT }, \ 325 { "recvspace", CTLTYPE_INT }, \ 326 { "keepinit", CTLTYPE_INT }, \ 327 } 328 329 #ifdef KERNEL 330 extern struct inpcbhead tcb; /* head of queue of active tcpcb's */ 331 extern struct inpcbinfo tcbinfo; 332 extern struct tcpstat tcpstat; /* tcp statistics */ 333 extern int tcp_mssdflt; /* XXX */ 334 extern u_long tcp_now; /* for RFC 1323 timestamps */ 335 336 void tcp_canceltimers __P((struct tcpcb *)); 337 struct tcpcb * 338 tcp_close __P((struct tcpcb *)); 339 void tcp_ctlinput __P((int, struct sockaddr *, void *)); 340 int tcp_ctloutput __P((int, struct socket *, int, int, struct mbuf **)); 341 struct tcpcb * 342 tcp_drop __P((struct tcpcb *, int)); 343 void tcp_drain __P((void)); 344 void tcp_fasttimo __P((void)); 345 struct rmxp_tao * 346 tcp_gettaocache __P((struct inpcb *)); 347 void tcp_init __P((void)); 348 void tcp_input __P((struct mbuf *, int)); 349 void tcp_mss __P((struct tcpcb *, int)); 350 int tcp_mssopt __P((struct tcpcb *)); 351 void tcp_mtudisc __P((struct inpcb *, int)); 352 struct tcpcb * 353 tcp_newtcpcb __P((struct inpcb *)); 354 int tcp_output __P((struct tcpcb *)); 355 void tcp_quench __P((struct inpcb *, int)); 356 void tcp_respond __P((struct tcpcb *, 357 struct tcpiphdr *, struct mbuf *, u_long, u_long, int)); 358 struct rtentry * 359 tcp_rtlookup __P((struct inpcb *)); 360 void tcp_setpersist __P((struct tcpcb *)); 361 void tcp_slowtimo __P((void)); 362 struct tcpiphdr * 363 tcp_template __P((struct tcpcb *)); 364 struct tcpcb * 365 tcp_timers __P((struct tcpcb *, int)); 366 void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int)); 367 368 extern struct pr_usrreqs tcp_usrreqs; 369 extern u_long tcp_sendspace; 370 extern u_long tcp_recvspace; 371 372 #endif /* KERNEL */ 373 374 #endif /* _NETINET_TCP_VAR_H_ */ 375