1 /* $OpenBSD: tcp_var.h,v 1.51 2003/06/09 07:40:25 itojun Exp $ */ 2 /* $NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1993, 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)tcp_var.h 8.3 (Berkeley) 4/10/94 33 */ 34 35 #ifndef _NETINET_TCP_VAR_H_ 36 #define _NETINET_TCP_VAR_H_ 37 38 struct sackblk { 39 tcp_seq start; /* start seq no. of sack block */ 40 tcp_seq end; /* end seq no. */ 41 }; 42 43 struct sackhole { 44 tcp_seq start; /* start seq no. of hole */ 45 tcp_seq end; /* end seq no. */ 46 int dups; /* number of dup(s)acks for this hole */ 47 tcp_seq rxmit; /* next seq. no in hole to be retransmitted */ 48 struct sackhole *next; /* next in list */ 49 }; 50 51 /* 52 * Kernel variables for tcp. 53 */ 54 55 /* 56 * Tcp control block, one per tcp; fields: 57 */ 58 struct tcpcb { 59 struct ipqehead segq; /* sequencing queue */ 60 struct timeout t_timer[TCPT_NTIMERS]; /* tcp timers */ 61 short t_state; /* state of this connection */ 62 short t_rxtshift; /* log(2) of rexmt exp. backoff */ 63 short t_rxtcur; /* current retransmit value */ 64 short t_dupacks; /* consecutive dup acks recd */ 65 u_short t_maxseg; /* maximum segment size */ 66 char t_force; /* 1 if forcing out a byte */ 67 u_int t_flags; 68 #define TF_ACKNOW 0x0001 /* ack peer immediately */ 69 #define TF_DELACK 0x0002 /* ack, but try to delay it */ 70 #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ 71 #define TF_NOOPT 0x0008 /* don't use tcp options */ 72 #define TF_SENTFIN 0x0010 /* have sent FIN */ 73 #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ 74 #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ 75 #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ 76 #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ 77 #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ 78 #define TF_SIGNATURE 0x0400 /* require TCP MD5 signature */ 79 #ifdef TCP_ECN 80 #define TF_ECN_PERMIT 0x00008000 /* other side said I could ECN */ 81 #define TF_RCVD_CE 0x00010000 /* send ECE in subsequent segs */ 82 #define TF_SEND_CWR 0x00020000 /* send CWR in next seg */ 83 #define TF_DISABLE_ECN 0x00040000 /* disable ECN for this connection */ 84 #endif 85 86 struct mbuf *t_template; /* skeletal packet for transmit */ 87 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 88 struct timeout t_delack_to; /* delayed ACK callback */ 89 /* 90 * The following fields are used as in the protocol specification. 91 * See RFC783, Dec. 1981, page 21. 92 */ 93 /* send sequence variables */ 94 tcp_seq snd_una; /* send unacknowledged */ 95 tcp_seq snd_nxt; /* send next */ 96 tcp_seq snd_up; /* send urgent pointer */ 97 tcp_seq snd_wl1; /* window update seg seq number */ 98 tcp_seq snd_wl2; /* window update seg ack number */ 99 tcp_seq iss; /* initial send sequence number */ 100 u_long snd_wnd; /* send window */ 101 #if 1 /*def TCP_SACK*/ 102 int sack_disable; /* disable SACK for this connection */ 103 int snd_numholes; /* number of holes seen by sender */ 104 struct sackhole *snd_holes; /* linked list of holes (sorted) */ 105 #if 1 /*defined(TCP_SACK) && defined(TCP_FACK)*/ 106 tcp_seq snd_fack; /* for FACK congestion control */ 107 u_long snd_awnd; /* snd_nxt - snd_fack + */ 108 /* retransmitted data */ 109 int retran_data; /* amount of outstanding retx. data */ 110 #endif /* TCP_FACK */ 111 #endif /* TCP_SACK */ 112 #if 1 /*defined(TCP_SACK) || defined(TCP_ECN)*/ 113 tcp_seq snd_last; /* for use in fast recovery */ 114 #endif 115 /* receive sequence variables */ 116 u_long rcv_wnd; /* receive window */ 117 tcp_seq rcv_nxt; /* receive next */ 118 tcp_seq rcv_up; /* receive urgent pointer */ 119 tcp_seq irs; /* initial receive sequence number */ 120 #if 1 /*def TCP_SACK*/ 121 tcp_seq rcv_laststart; /* start of last segment recd. */ 122 tcp_seq rcv_lastend; /* end of ... */ 123 tcp_seq rcv_lastsack; /* last seq number(+1) sack'd by rcv'r*/ 124 int rcv_numsacks; /* # distinct sack blks present */ 125 struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */ 126 #endif 127 128 /* 129 * Additional variables for this implementation. 130 */ 131 /* receive variables */ 132 tcp_seq rcv_adv; /* advertised window */ 133 /* retransmit variables */ 134 tcp_seq snd_max; /* highest sequence number sent; 135 * used to recognize retransmits 136 */ 137 /* congestion control (for slow start, source quench, retransmit after loss) */ 138 u_long snd_cwnd; /* congestion-controlled window */ 139 u_long snd_ssthresh; /* snd_cwnd size threshhold for 140 * for slow start exponential to 141 * linear switch 142 */ 143 u_short t_maxopd; /* mss plus options */ 144 u_short t_peermss; /* peer's maximum segment size */ 145 146 /* 147 * transmit timing stuff. See below for scale of srtt and rttvar. 148 * "Variance" is actually smoothed difference. 149 */ 150 uint32_t t_rcvtime; /* time last segment received */ 151 uint32_t t_rtttime; /* time we started measuring rtt */ 152 tcp_seq t_rtseq; /* sequence number being timed */ 153 short t_srtt; /* smoothed round-trip time */ 154 short t_rttvar; /* variance in round-trip time */ 155 u_short t_rttmin; /* minimum rtt allowed */ 156 u_long max_sndwnd; /* largest window peer has offered */ 157 158 /* out-of-band data */ 159 char t_oobflags; /* have some */ 160 char t_iobc; /* input character */ 161 #define TCPOOB_HAVEDATA 0x01 162 #define TCPOOB_HADDATA 0x02 163 short t_softerror; /* possible error not yet reported */ 164 165 /* RFC 1323 variables */ 166 u_char snd_scale; /* window scaling for send window */ 167 u_char rcv_scale; /* window scaling for recv window */ 168 u_char request_r_scale; /* pending window scaling */ 169 u_char requested_s_scale; 170 u_int32_t ts_recent; /* timestamp echo data */ 171 u_int32_t ts_recent_age; /* when last updated */ 172 tcp_seq last_ack_sent; 173 174 /* TUBA stuff */ 175 caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */ 176 177 int pf; 178 }; 179 180 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 181 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 182 183 #ifdef _KERNEL 184 extern int tcp_delack_ticks; 185 void tcp_delack(void *); 186 187 #define TCP_INIT_DELACK(tp) \ 188 timeout_set(&(tp)->t_delack_to, tcp_delack, tp) 189 190 #define TCP_RESTART_DELACK(tp) \ 191 timeout_add(&(tp)->t_delack_to, tcp_delack_ticks) 192 193 #define TCP_SET_DELACK(tp) \ 194 do { \ 195 if (((tp)->t_flags & TF_DELACK) == 0) { \ 196 (tp)->t_flags |= TF_DELACK; \ 197 TCP_RESTART_DELACK(tp); \ 198 } \ 199 } while (/*CONSTCOND*/0) 200 201 #define TCP_CLEAR_DELACK(tp) \ 202 do { \ 203 if ((tp)->t_flags & TF_DELACK) { \ 204 (tp)->t_flags &= ~TF_DELACK; \ 205 timeout_del(&(tp)->t_delack_to); \ 206 } \ 207 } while (/*CONSTCOND*/0) 208 #endif /* _KERNEL */ 209 210 /* 211 * The smoothed round-trip time and estimated variance 212 * are stored as fixed point numbers scaled by the values below. 213 * For convenience, these scales are also used in smoothing the average 214 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 215 * With these scales, srtt has 3 bits to the right of the binary point, 216 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the 217 * binary point, and is smoothed with an ALPHA of 0.75. 218 */ 219 #define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */ 220 #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ 221 #define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */ 222 #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */ 223 224 /* 225 * The initial retransmission should happen at rtt + 4 * rttvar. 226 * Because of the way we do the smoothing, srtt and rttvar 227 * will each average +1/2 tick of bias. When we compute 228 * the retransmit timer, we want 1/2 tick of rounding and 229 * 1 extra tick because of +-1/2 tick uncertainty in the 230 * firing of the timer. The bias will give us exactly the 231 * 1.5 tick we need. But, because the bias is 232 * statistical, we have to test that we don't drop below 233 * the minimum feasible timer (which is 2 ticks). 234 * This macro assumes that the value of TCP_RTTVAR_SCALE 235 * is the same as the multiplier for rttvar. 236 */ 237 #define TCP_REXMTVAL(tp) \ 238 ((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2) 239 240 /* 241 * TCP statistics. 242 * Many of these should be kept per connection, 243 * but that's inconvenient at the moment. 244 */ 245 struct tcpstat { 246 u_int32_t tcps_connattempt; /* connections initiated */ 247 u_int32_t tcps_accepts; /* connections accepted */ 248 u_int32_t tcps_connects; /* connections established */ 249 u_int32_t tcps_drops; /* connections dropped */ 250 u_int32_t tcps_conndrops; /* embryonic connections dropped */ 251 u_int32_t tcps_closed; /* conn. closed (includes drops) */ 252 u_int32_t tcps_segstimed; /* segs where we tried to get rtt */ 253 u_int32_t tcps_rttupdated; /* times we succeeded */ 254 u_int32_t tcps_delack; /* delayed acks sent */ 255 u_int32_t tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 256 u_int32_t tcps_rexmttimeo; /* retransmit timeouts */ 257 u_int32_t tcps_persisttimeo; /* persist timeouts */ 258 u_int32_t tcps_persistdrop; /* connections dropped in persist */ 259 u_int32_t tcps_keeptimeo; /* keepalive timeouts */ 260 u_int32_t tcps_keepprobe; /* keepalive probes sent */ 261 u_int32_t tcps_keepdrops; /* connections dropped in keepalive */ 262 263 u_int32_t tcps_sndtotal; /* total packets sent */ 264 u_int32_t tcps_sndpack; /* data packets sent */ 265 u_int64_t tcps_sndbyte; /* data bytes sent */ 266 u_int32_t tcps_sndrexmitpack; /* data packets retransmitted */ 267 u_int64_t tcps_sndrexmitbyte; /* data bytes retransmitted */ 268 u_int64_t tcps_sndrexmitfast; /* Fast retransmits */ 269 u_int32_t tcps_sndacks; /* ack-only packets sent */ 270 u_int32_t tcps_sndprobe; /* window probes sent */ 271 u_int32_t tcps_sndurg; /* packets sent with URG only */ 272 u_int32_t tcps_sndwinup; /* window update-only packets sent */ 273 u_int32_t tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 274 275 u_int32_t tcps_rcvtotal; /* total packets received */ 276 u_int32_t tcps_rcvpack; /* packets received in sequence */ 277 u_int64_t tcps_rcvbyte; /* bytes received in sequence */ 278 u_int32_t tcps_rcvbadsum; /* packets received with ccksum errs */ 279 u_int32_t tcps_rcvbadoff; /* packets received with bad offset */ 280 u_int32_t tcps_rcvmemdrop; /* packets dropped for lack of memory */ 281 u_int32_t tcps_rcvnosec; /* packets dropped for lack of ipsec */ 282 u_int32_t tcps_rcvshort; /* packets received too short */ 283 u_int32_t tcps_rcvduppack; /* duplicate-only packets received */ 284 u_int64_t tcps_rcvdupbyte; /* duplicate-only bytes received */ 285 u_int32_t tcps_rcvpartduppack; /* packets with some duplicate data */ 286 u_int64_t tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 287 u_int32_t tcps_rcvoopack; /* out-of-order packets received */ 288 u_int64_t tcps_rcvoobyte; /* out-of-order bytes received */ 289 u_int32_t tcps_rcvpackafterwin; /* packets with data after window */ 290 u_int64_t tcps_rcvbyteafterwin; /* bytes rcvd after window */ 291 u_int32_t tcps_rcvafterclose; /* packets rcvd after "close" */ 292 u_int32_t tcps_rcvwinprobe; /* rcvd window probe packets */ 293 u_int32_t tcps_rcvdupack; /* rcvd duplicate acks */ 294 u_int32_t tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 295 u_int32_t tcps_rcvackpack; /* rcvd ack packets */ 296 u_int64_t tcps_rcvackbyte; /* bytes acked by rcvd acks */ 297 u_int32_t tcps_rcvwinupd; /* rcvd window update packets */ 298 u_int32_t tcps_pawsdrop; /* segments dropped due to PAWS */ 299 u_int32_t tcps_predack; /* times hdr predict ok for acks */ 300 u_int32_t tcps_preddat; /* times hdr predict ok for data pkts */ 301 302 u_int32_t tcps_pcbhashmiss; /* input packets missing pcb hash */ 303 u_int32_t tcps_noport; /* no socket on port */ 304 u_int32_t tcps_badsyn; /* SYN packet with src==dst rcv'ed */ 305 306 u_int32_t tcps_rcvbadsig; /* rcvd bad/missing TCP signatures */ 307 u_int64_t tcps_rcvgoodsig; /* rcvd good TCP signatures */ 308 u_int32_t tcps_inhwcsum; /* input hardware-checksummed packets */ 309 u_int32_t tcps_outhwcsum; /* output hardware-checksummed packets */ 310 311 /* ECN stats */ 312 u_int32_t tcps_ecn_accepts; /* ecn connections accepted */ 313 u_int32_t tcps_ecn_rcvece; /* # of rcvd ece */ 314 u_int32_t tcps_ecn_rcvcwr; /* # of rcvd cwr */ 315 u_int32_t tcps_ecn_rcvce; /* # of rcvd ce in ip header */ 316 u_int32_t tcps_ecn_sndect; /* # of cwr sent */ 317 u_int32_t tcps_ecn_sndece; /* # of ece sent */ 318 u_int32_t tcps_ecn_sndcwr; /* # of cwr sent */ 319 u_int32_t tcps_cwr_ecn; /* # of cwnd reduced by ecn */ 320 u_int32_t tcps_cwr_frecovery; /* # of cwnd reduced by fastrecovery */ 321 u_int32_t tcps_cwr_timeout; /* # of cwnd reduced by timeout */ 322 }; 323 324 /* 325 * Names for TCP sysctl objects. 326 */ 327 328 #define TCPCTL_RFC1323 1 /* enable/disable RFC1323 timestamps/scaling */ 329 #define TCPCTL_KEEPINITTIME 2 /* TCPT_KEEP value */ 330 #define TCPCTL_KEEPIDLE 3 /* allow tcp_keepidle to be changed */ 331 #define TCPCTL_KEEPINTVL 4 /* allow tcp_keepintvl to be changed */ 332 #define TCPCTL_SLOWHZ 5 /* return kernel idea of PR_SLOWHZ */ 333 #define TCPCTL_BADDYNAMIC 6 /* return bad dynamic port bitmap */ 334 #define TCPCTL_RECVSPACE 7 /* receive buffer space */ 335 #define TCPCTL_SENDSPACE 8 /* send buffer space */ 336 #define TCPCTL_IDENT 9 /* get connection owner */ 337 #define TCPCTL_SACK 10 /* selective acknowledgement, rfc 2018 */ 338 #define TCPCTL_MSSDFLT 11 /* Default maximum segment size */ 339 #define TCPCTL_RSTPPSLIMIT 12 /* RST pps limit */ 340 #define TCPCTL_ACK_ON_PUSH 13 /* ACK immediately on PUSH */ 341 #define TCPCTL_ECN 14 /* RFC3168 ECN */ 342 #define TCPCTL_MAXID 15 343 344 #define TCPCTL_NAMES { \ 345 { 0, 0 }, \ 346 { "rfc1323", CTLTYPE_INT }, \ 347 { "keepinittime", CTLTYPE_INT }, \ 348 { "keepidle", CTLTYPE_INT }, \ 349 { "keepintvl", CTLTYPE_INT }, \ 350 { "slowhz", CTLTYPE_INT }, \ 351 { "baddynamic", CTLTYPE_STRUCT }, \ 352 { "recvspace", CTLTYPE_INT }, \ 353 { "sendspace", CTLTYPE_INT }, \ 354 { "ident", CTLTYPE_STRUCT }, \ 355 { "sack", CTLTYPE_INT }, \ 356 { "mssdflt", CTLTYPE_INT }, \ 357 { "rstppslimit", CTLTYPE_INT }, \ 358 { "ackonpush", CTLTYPE_INT }, \ 359 { "ecn", CTLTYPE_INT }, \ 360 } 361 362 struct tcp_ident_mapping { 363 struct sockaddr_storage faddr, laddr; 364 int euid, ruid; 365 }; 366 367 #ifdef _KERNEL 368 extern struct inpcbtable tcbtable; /* head of queue of active tcpcb's */ 369 extern struct tcpstat tcpstat; /* tcp statistics */ 370 extern u_int32_t tcp_now; /* for RFC 1323 timestamps */ 371 extern int tcp_do_rfc1323; /* enabled/disabled? */ 372 extern int tcp_mssdflt; /* default maximum segment size */ 373 extern int tcp_ack_on_push; /* ACK immediately on PUSH */ 374 #ifdef TCP_SACK 375 extern int tcp_do_sack; /* SACK enabled/disabled */ 376 extern struct pool sackhl_pool; 377 #endif 378 extern int tcp_do_ecn; /* RFC3168 ECN enabled/disabled? */ 379 380 int tcp_attach(struct socket *); 381 void tcp_canceltimers(struct tcpcb *); 382 struct tcpcb * 383 tcp_close(struct tcpcb *); 384 #if defined(INET6) && !defined(TCP6) 385 void tcp6_ctlinput(int, struct sockaddr *, void *); 386 #endif 387 void *tcp_ctlinput(int, struct sockaddr *, void *); 388 int tcp_ctloutput(int, struct socket *, int, int, struct mbuf **); 389 struct tcpcb * 390 tcp_disconnect(struct tcpcb *); 391 struct tcpcb * 392 tcp_drop(struct tcpcb *, int); 393 void tcp_dooptions(struct tcpcb *, u_char *, int, struct tcphdr *, 394 int *, u_int32_t *, u_int32_t *); 395 void tcp_drain(void); 396 void tcp_init(void); 397 #if defined(INET6) && !defined(TCP6) 398 int tcp6_input(struct mbuf **, int *, int); 399 #endif 400 void tcp_input(struct mbuf *, ...); 401 int tcp_mss(struct tcpcb *, int); 402 void tcp_mss_update(struct tcpcb *); 403 void tcp_mtudisc(struct inpcb *, int); 404 void tcp_mtudisc_increase(struct inpcb *, int); 405 #ifdef INET6 406 void tcp6_mtudisc(struct inpcb *, int); 407 void tcp6_mtudisc_callback(struct in6_addr *); 408 #endif 409 struct tcpcb * 410 tcp_newtcpcb(struct inpcb *); 411 void tcp_notify(struct inpcb *, int); 412 int tcp_output(struct tcpcb *); 413 void tcp_pulloutofband(struct socket *, u_int, struct mbuf *, int); 414 void tcp_quench(struct inpcb *, int); 415 int tcp_reass(struct tcpcb *, struct tcphdr *, struct mbuf *, int *); 416 void tcp_rscale(struct tcpcb *, u_long); 417 void tcp_respond(struct tcpcb *, caddr_t, struct mbuf *, tcp_seq, 418 tcp_seq, int); 419 void tcp_setpersist(struct tcpcb *); 420 void tcp_slowtimo(void); 421 struct mbuf * 422 tcp_template(struct tcpcb *); 423 void tcp_trace(int, int, struct tcpcb *, caddr_t, int, int); 424 struct tcpcb * 425 tcp_usrclosed(struct tcpcb *); 426 int tcp_sysctl(int *, u_int, void *, size_t *, void *, size_t); 427 #if defined(INET6) && !defined(TCP6) 428 int tcp6_usrreq(struct socket *, 429 int, struct mbuf *, struct mbuf *, struct mbuf *, struct proc *); 430 #endif 431 int tcp_usrreq(struct socket *, 432 int, struct mbuf *, struct mbuf *, struct mbuf *); 433 void tcp_xmit_timer(struct tcpcb *, int); 434 void tcpdropoldhalfopen(struct tcpcb *, u_int16_t); 435 #ifdef TCP_SACK 436 int tcp_sack_option(struct tcpcb *,struct tcphdr *,u_char *,int); 437 void tcp_update_sack_list(struct tcpcb *tp); 438 void tcp_del_sackholes(struct tcpcb *, struct tcphdr *); 439 void tcp_clean_sackreport(struct tcpcb *tp); 440 void tcp_sack_adjust(struct tcpcb *tp); 441 struct sackhole * 442 tcp_sack_output(struct tcpcb *tp); 443 int tcp_sack_partialack(struct tcpcb *, struct tcphdr *); 444 #ifdef DEBUG 445 void tcp_print_holes(struct tcpcb *tp); 446 #endif 447 #endif /* TCP_SACK */ 448 #if defined(TCP_SACK) 449 int tcp_newreno(struct tcpcb *, struct tcphdr *); 450 u_long tcp_seq_subtract(u_long, u_long ); 451 #endif /* TCP_SACK */ 452 #ifdef TCP_SIGNATURE 453 int tcp_signature_apply(caddr_t, caddr_t, unsigned int); 454 #endif /* TCP_SIGNATURE */ 455 void tcp_rndiss_init(void); 456 tcp_seq tcp_rndiss_next(void); 457 u_int16_t 458 tcp_rndiss_encrypt(u_int16_t); 459 #endif /* _KERNEL */ 460 #endif /* _NETINET_TCP_VAR_H_ */ 461