1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1993, 1994, 1995 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95 32 * $FreeBSD$ 33 */ 34 35 #ifndef _NETINET_TCP_VAR_H_ 36 #define _NETINET_TCP_VAR_H_ 37 38 #include <netinet/tcp.h> 39 #include <netinet/tcp_fsm.h> 40 41 #ifdef _KERNEL 42 #include <net/vnet.h> 43 #include <sys/mbuf.h> 44 #endif 45 46 #if defined(_KERNEL) || defined(_WANT_TCPCB) 47 /* TCP segment queue entry */ 48 struct tseg_qent { 49 LIST_ENTRY(tseg_qent) tqe_q; 50 int tqe_len; /* TCP segment data length */ 51 struct tcphdr *tqe_th; /* a pointer to tcp header */ 52 struct mbuf *tqe_m; /* mbuf contains packet */ 53 }; 54 LIST_HEAD(tsegqe_head, tseg_qent); 55 56 struct sackblk { 57 tcp_seq start; /* start seq no. of sack block */ 58 tcp_seq end; /* end seq no. */ 59 }; 60 61 struct sackhole { 62 tcp_seq start; /* start seq no. of hole */ 63 tcp_seq end; /* end seq no. */ 64 tcp_seq rxmit; /* next seq. no in hole to be retransmitted */ 65 TAILQ_ENTRY(sackhole) scblink; /* scoreboard linkage */ 66 }; 67 68 struct sackhint { 69 struct sackhole *nexthole; 70 int sack_bytes_rexmit; 71 tcp_seq last_sack_ack; /* Most recent/largest sacked ack */ 72 73 int ispare; /* explicit pad for 64bit alignment */ 74 int sacked_bytes; /* 75 * Total sacked bytes reported by the 76 * receiver via sack option 77 */ 78 uint32_t _pad1[1]; /* TBD */ 79 uint64_t _pad[1]; /* TBD */ 80 }; 81 82 /* 83 * Tcp control block, one per tcp; fields: 84 * Organized for 16 byte cacheline efficiency. 85 */ 86 struct tcpcb { 87 struct tsegqe_head t_segq; /* segment reassembly queue */ 88 int t_segqlen; /* segment reassembly queue length */ 89 int t_dupacks; /* consecutive dup acks recd */ 90 91 struct tcp_timer *t_timers; /* All the TCP timers in one struct */ 92 93 struct inpcb *t_inpcb; /* back pointer to internet pcb */ 94 int t_state; /* state of this connection */ 95 u_int t_flags; 96 97 struct vnet *t_vnet; /* back pointer to parent vnet */ 98 99 tcp_seq snd_una; /* sent but unacknowledged */ 100 tcp_seq snd_max; /* highest sequence number sent; 101 * used to recognize retransmits 102 */ 103 tcp_seq snd_nxt; /* send next */ 104 tcp_seq snd_up; /* send urgent pointer */ 105 106 tcp_seq snd_wl1; /* window update seg seq number */ 107 tcp_seq snd_wl2; /* window update seg ack number */ 108 tcp_seq iss; /* initial send sequence number */ 109 tcp_seq irs; /* initial receive sequence number */ 110 111 tcp_seq rcv_nxt; /* receive next */ 112 tcp_seq rcv_adv; /* advertised window */ 113 uint32_t rcv_wnd; /* receive window */ 114 tcp_seq rcv_up; /* receive urgent pointer */ 115 116 uint32_t snd_wnd; /* send window */ 117 uint32_t snd_cwnd; /* congestion-controlled window */ 118 uint32_t snd_ssthresh; /* snd_cwnd size threshold for 119 * for slow start exponential to 120 * linear switch 121 */ 122 tcp_seq snd_recover; /* for use in NewReno Fast Recovery */ 123 124 u_int t_rcvtime; /* inactivity time */ 125 u_int t_starttime; /* time connection was established */ 126 u_int t_rtttime; /* RTT measurement start time */ 127 tcp_seq t_rtseq; /* sequence number being timed */ 128 129 int t_rxtcur; /* current retransmit value (ticks) */ 130 u_int t_maxseg; /* maximum segment size */ 131 u_int t_pmtud_saved_maxseg; /* pre-blackhole MSS */ 132 int t_srtt; /* smoothed round-trip time */ 133 int t_rttvar; /* variance in round-trip time */ 134 135 int t_rxtshift; /* log(2) of rexmt exp. backoff */ 136 u_int t_rttmin; /* minimum rtt allowed */ 137 u_int t_rttbest; /* best rtt we've seen */ 138 u_long t_rttupdated; /* number of times rtt sampled */ 139 uint32_t max_sndwnd; /* largest window peer has offered */ 140 141 int t_softerror; /* possible error not yet reported */ 142 /* out-of-band data */ 143 char t_oobflags; /* have some */ 144 char t_iobc; /* input character */ 145 /* RFC 1323 variables */ 146 u_char snd_scale; /* window scaling for send window */ 147 u_char rcv_scale; /* window scaling for recv window */ 148 u_char request_r_scale; /* pending window scaling */ 149 u_int32_t ts_recent; /* timestamp echo data */ 150 u_int ts_recent_age; /* when last updated */ 151 u_int32_t ts_offset; /* our timestamp offset */ 152 153 tcp_seq last_ack_sent; 154 /* experimental */ 155 uint32_t snd_cwnd_prev; /* cwnd prior to retransmit */ 156 uint32_t snd_ssthresh_prev; /* ssthresh prior to retransmit */ 157 tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */ 158 int t_sndzerowin; /* zero-window updates sent */ 159 u_int t_badrxtwin; /* window for retransmit recovery */ 160 u_char snd_limited; /* segments limited transmitted */ 161 /* SACK related state */ 162 int snd_numholes; /* number of holes seen by sender */ 163 TAILQ_HEAD(sackhole_head, sackhole) snd_holes; 164 /* SACK scoreboard (sorted) */ 165 tcp_seq snd_fack; /* last seq number(+1) sack'd by rcv'r*/ 166 int rcv_numsacks; /* # distinct sack blks present */ 167 struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */ 168 tcp_seq sack_newdata; /* New data xmitted in this recovery 169 episode starts at this seq number */ 170 struct sackhint sackhint; /* SACK scoreboard hint */ 171 int t_rttlow; /* smallest observerved RTT */ 172 u_int32_t rfbuf_ts; /* recv buffer autoscaling timestamp */ 173 int rfbuf_cnt; /* recv buffer autoscaling byte count */ 174 struct toedev *tod; /* toedev handling this connection */ 175 int t_sndrexmitpack; /* retransmit packets sent */ 176 int t_rcvoopack; /* out-of-order packets received */ 177 void *t_toe; /* TOE pcb pointer */ 178 int t_bytes_acked; /* # bytes acked during current RTT */ 179 struct cc_algo *cc_algo; /* congestion control algorithm */ 180 struct cc_var *ccv; /* congestion control specific vars */ 181 struct osd *osd; /* storage for Khelp module data */ 182 183 u_int t_keepinit; /* time to establish connection */ 184 u_int t_keepidle; /* time before keepalive probes begin */ 185 u_int t_keepintvl; /* interval between keepalives */ 186 u_int t_keepcnt; /* number of keepalives before close */ 187 188 u_int t_tsomax; /* TSO total burst length limit in bytes */ 189 u_int t_tsomaxsegcount; /* TSO maximum segment count */ 190 u_int t_tsomaxsegsize; /* TSO maximum segment size in bytes */ 191 u_int t_flags2; /* More tcpcb flags storage */ 192 struct tcp_function_block *t_fb;/* TCP function call block */ 193 void *t_fb_ptr; /* Pointer to t_fb specific data */ 194 #ifdef TCP_RFC7413 195 uint64_t t_tfo_cookie; /* TCP Fast Open cookie */ 196 unsigned int *t_tfo_pending; /* TCP Fast Open pending counter */ 197 #endif 198 #ifdef TCPPCAP 199 struct mbufq t_inpkts; /* List of saved input packets. */ 200 struct mbufq t_outpkts; /* List of saved output packets. */ 201 #endif 202 }; 203 #endif /* _KERNEL || _WANT_TCPCB */ 204 205 #ifdef _KERNEL 206 struct tcptemp { 207 u_char tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */ 208 struct tcphdr tt_t; 209 }; 210 211 /* 212 * TODO: We yet need to brave plowing in 213 * to tcp_input() and the pru_usrreq() block. 214 * Right now these go to the old standards which 215 * are somewhat ok, but in the long term may 216 * need to be changed. If we do tackle tcp_input() 217 * then we need to get rid of the tcp_do_segment() 218 * function below. 219 */ 220 /* Flags for tcp functions */ 221 #define TCP_FUNC_BEING_REMOVED 0x01 /* Can no longer be referenced */ 222 223 /* 224 * If defining the optional tcp_timers, in the 225 * tfb_tcp_timer_stop call you must use the 226 * callout_async_drain() function with the 227 * tcp_timer_discard callback. You should check 228 * the return of callout_async_drain() and if 0 229 * increment tt_draincnt. Since the timer sub-system 230 * does not know your callbacks you must provide a 231 * stop_all function that loops through and calls 232 * tcp_timer_stop() with each of your defined timers. 233 * Adding a tfb_tcp_handoff_ok function allows the socket 234 * option to change stacks to query you even if the 235 * connection is in a later stage. You return 0 to 236 * say you can take over and run your stack, you return 237 * non-zero (an error number) to say no you can't. 238 * If the function is undefined you can only change 239 * in the early states (before connect or listen). 240 * tfb_tcp_fb_fini is changed to add a flag to tell 241 * the old stack if the tcb is being destroyed or 242 * not. A one in the flag means the TCB is being 243 * destroyed, a zero indicates its transitioning to 244 * another stack (via socket option). 245 */ 246 struct tcp_function_block { 247 char tfb_tcp_block_name[TCP_FUNCTION_NAME_LEN_MAX]; 248 int (*tfb_tcp_output)(struct tcpcb *); 249 void (*tfb_tcp_do_segment)(struct mbuf *, struct tcphdr *, 250 struct socket *, struct tcpcb *, 251 int, int, uint8_t, 252 int); 253 int (*tfb_tcp_ctloutput)(struct socket *so, struct sockopt *sopt, 254 struct inpcb *inp, struct tcpcb *tp); 255 /* Optional memory allocation/free routine */ 256 void (*tfb_tcp_fb_init)(struct tcpcb *); 257 void (*tfb_tcp_fb_fini)(struct tcpcb *, int); 258 /* Optional timers, must define all if you define one */ 259 int (*tfb_tcp_timer_stop_all)(struct tcpcb *); 260 void (*tfb_tcp_timer_activate)(struct tcpcb *, 261 uint32_t, u_int); 262 int (*tfb_tcp_timer_active)(struct tcpcb *, uint32_t); 263 void (*tfb_tcp_timer_stop)(struct tcpcb *, uint32_t); 264 void (*tfb_tcp_rexmit_tmr)(struct tcpcb *); 265 int (*tfb_tcp_handoff_ok)(struct tcpcb *); 266 volatile uint32_t tfb_refcnt; 267 uint32_t tfb_flags; 268 }; 269 270 struct tcp_function { 271 TAILQ_ENTRY(tcp_function) tf_next; 272 char tf_name[TCP_FUNCTION_NAME_LEN_MAX]; 273 struct tcp_function_block *tf_fb; 274 }; 275 276 TAILQ_HEAD(tcp_funchead, tcp_function); 277 #endif /* _KERNEL */ 278 279 /* 280 * Flags and utility macros for the t_flags field. 281 */ 282 #define TF_ACKNOW 0x000001 /* ack peer immediately */ 283 #define TF_DELACK 0x000002 /* ack, but try to delay it */ 284 #define TF_NODELAY 0x000004 /* don't delay packets to coalesce */ 285 #define TF_NOOPT 0x000008 /* don't use tcp options */ 286 #define TF_SENTFIN 0x000010 /* have sent FIN */ 287 #define TF_REQ_SCALE 0x000020 /* have/will request window scaling */ 288 #define TF_RCVD_SCALE 0x000040 /* other side has requested scaling */ 289 #define TF_REQ_TSTMP 0x000080 /* have/will request timestamps */ 290 #define TF_RCVD_TSTMP 0x000100 /* a timestamp was received in SYN */ 291 #define TF_SACK_PERMIT 0x000200 /* other side said I could SACK */ 292 #define TF_NEEDSYN 0x000400 /* send SYN (implicit state) */ 293 #define TF_NEEDFIN 0x000800 /* send FIN (implicit state) */ 294 #define TF_NOPUSH 0x001000 /* don't push */ 295 #define TF_PREVVALID 0x002000 /* saved values for bad rxmit valid */ 296 #define TF_MORETOCOME 0x010000 /* More data to be appended to sock */ 297 #define TF_LQ_OVERFLOW 0x020000 /* listen queue overflow */ 298 #define TF_LASTIDLE 0x040000 /* connection was previously idle */ 299 #define TF_RXWIN0SENT 0x080000 /* sent a receiver win 0 in response */ 300 #define TF_FASTRECOVERY 0x100000 /* in NewReno Fast Recovery */ 301 #define TF_WASFRECOVERY 0x200000 /* was in NewReno Fast Recovery */ 302 #define TF_SIGNATURE 0x400000 /* require MD5 digests (RFC2385) */ 303 #define TF_FORCEDATA 0x800000 /* force out a byte */ 304 #define TF_TSO 0x1000000 /* TSO enabled on this connection */ 305 #define TF_TOE 0x2000000 /* this connection is offloaded */ 306 #define TF_ECN_PERMIT 0x4000000 /* connection ECN-ready */ 307 #define TF_ECN_SND_CWR 0x8000000 /* ECN CWR in queue */ 308 #define TF_ECN_SND_ECE 0x10000000 /* ECN ECE in queue */ 309 #define TF_CONGRECOVERY 0x20000000 /* congestion recovery mode */ 310 #define TF_WASCRECOVERY 0x40000000 /* was in congestion recovery */ 311 #define TF_FASTOPEN 0x80000000 /* TCP Fast Open indication */ 312 313 #define IN_FASTRECOVERY(t_flags) (t_flags & TF_FASTRECOVERY) 314 #define ENTER_FASTRECOVERY(t_flags) t_flags |= TF_FASTRECOVERY 315 #define EXIT_FASTRECOVERY(t_flags) t_flags &= ~TF_FASTRECOVERY 316 317 #define IN_CONGRECOVERY(t_flags) (t_flags & TF_CONGRECOVERY) 318 #define ENTER_CONGRECOVERY(t_flags) t_flags |= TF_CONGRECOVERY 319 #define EXIT_CONGRECOVERY(t_flags) t_flags &= ~TF_CONGRECOVERY 320 321 #define IN_RECOVERY(t_flags) (t_flags & (TF_CONGRECOVERY | TF_FASTRECOVERY)) 322 #define ENTER_RECOVERY(t_flags) t_flags |= (TF_CONGRECOVERY | TF_FASTRECOVERY) 323 #define EXIT_RECOVERY(t_flags) t_flags &= ~(TF_CONGRECOVERY | TF_FASTRECOVERY) 324 325 #if defined(_KERNEL) && !defined(TCP_RFC7413) 326 #define IS_FASTOPEN(t_flags) (false) 327 #else 328 #define IS_FASTOPEN(t_flags) (t_flags & TF_FASTOPEN) 329 #endif 330 331 #define BYTES_THIS_ACK(tp, th) (th->th_ack - tp->snd_una) 332 333 /* 334 * Flags for the t_oobflags field. 335 */ 336 #define TCPOOB_HAVEDATA 0x01 337 #define TCPOOB_HADDATA 0x02 338 339 /* 340 * Flags for PLPMTU handling, t_flags2 341 */ 342 #define TF2_PLPMTU_BLACKHOLE 0x00000001 /* Possible PLPMTUD Black Hole. */ 343 #define TF2_PLPMTU_PMTUD 0x00000002 /* Allowed to attempt PLPMTUD. */ 344 #define TF2_PLPMTU_MAXSEGSNT 0x00000004 /* Last seg sent was full seg. */ 345 346 /* 347 * Structure to hold TCP options that are only used during segment 348 * processing (in tcp_input), but not held in the tcpcb. 349 * It's basically used to reduce the number of parameters 350 * to tcp_dooptions and tcp_addoptions. 351 * The binary order of the to_flags is relevant for packing of the 352 * options in tcp_addoptions. 353 */ 354 struct tcpopt { 355 u_int32_t to_flags; /* which options are present */ 356 #define TOF_MSS 0x0001 /* maximum segment size */ 357 #define TOF_SCALE 0x0002 /* window scaling */ 358 #define TOF_SACKPERM 0x0004 /* SACK permitted */ 359 #define TOF_TS 0x0010 /* timestamp */ 360 #define TOF_SIGNATURE 0x0040 /* TCP-MD5 signature option (RFC2385) */ 361 #define TOF_SACK 0x0080 /* Peer sent SACK option */ 362 #define TOF_FASTOPEN 0x0100 /* TCP Fast Open (TFO) cookie */ 363 #define TOF_MAXOPT 0x0200 364 u_int32_t to_tsval; /* new timestamp */ 365 u_int32_t to_tsecr; /* reflected timestamp */ 366 u_char *to_sacks; /* pointer to the first SACK blocks */ 367 u_char *to_signature; /* pointer to the TCP-MD5 signature */ 368 u_char *to_tfo_cookie; /* pointer to the TFO cookie */ 369 u_int16_t to_mss; /* maximum segment size */ 370 u_int8_t to_wscale; /* window scaling */ 371 u_int8_t to_nsacks; /* number of SACK blocks */ 372 u_int8_t to_tfo_len; /* TFO cookie length */ 373 u_int32_t to_spare; /* UTO */ 374 }; 375 376 /* 377 * Flags for tcp_dooptions. 378 */ 379 #define TO_SYN 0x01 /* parse SYN-only options */ 380 381 struct hc_metrics_lite { /* must stay in sync with hc_metrics */ 382 uint32_t rmx_mtu; /* MTU for this path */ 383 uint32_t rmx_ssthresh; /* outbound gateway buffer limit */ 384 uint32_t rmx_rtt; /* estimated round trip time */ 385 uint32_t rmx_rttvar; /* estimated rtt variance */ 386 uint32_t rmx_cwnd; /* congestion window */ 387 uint32_t rmx_sendpipe; /* outbound delay-bandwidth product */ 388 uint32_t rmx_recvpipe; /* inbound delay-bandwidth product */ 389 }; 390 391 /* 392 * Used by tcp_maxmtu() to communicate interface specific features 393 * and limits at the time of connection setup. 394 */ 395 struct tcp_ifcap { 396 int ifcap; 397 u_int tsomax; 398 u_int tsomaxsegcount; 399 u_int tsomaxsegsize; 400 }; 401 402 #ifndef _NETINET_IN_PCB_H_ 403 struct in_conninfo; 404 #endif /* _NETINET_IN_PCB_H_ */ 405 406 struct tcptw { 407 struct inpcb *tw_inpcb; /* XXX back pointer to internet pcb */ 408 tcp_seq snd_nxt; 409 tcp_seq rcv_nxt; 410 tcp_seq iss; 411 tcp_seq irs; 412 u_short last_win; /* cached window value */ 413 short tw_so_options; /* copy of so_options */ 414 struct ucred *tw_cred; /* user credentials */ 415 u_int32_t t_recent; 416 u_int32_t ts_offset; /* our timestamp offset */ 417 u_int t_starttime; 418 int tw_time; 419 TAILQ_ENTRY(tcptw) tw_2msl; 420 void *tw_pspare; /* TCP_SIGNATURE */ 421 u_int *tw_spare; /* TCP_SIGNATURE */ 422 }; 423 424 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb) 425 #define intotw(ip) ((struct tcptw *)(ip)->inp_ppcb) 426 #define sototcpcb(so) (intotcpcb(sotoinpcb(so))) 427 428 /* 429 * The smoothed round-trip time and estimated variance 430 * are stored as fixed point numbers scaled by the values below. 431 * For convenience, these scales are also used in smoothing the average 432 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). 433 * With these scales, srtt has 3 bits to the right of the binary point, 434 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the 435 * binary point, and is smoothed with an ALPHA of 0.75. 436 */ 437 #define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */ 438 #define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */ 439 #define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */ 440 #define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */ 441 #define TCP_DELTA_SHIFT 2 /* see tcp_input.c */ 442 443 /* 444 * The initial retransmission should happen at rtt + 4 * rttvar. 445 * Because of the way we do the smoothing, srtt and rttvar 446 * will each average +1/2 tick of bias. When we compute 447 * the retransmit timer, we want 1/2 tick of rounding and 448 * 1 extra tick because of +-1/2 tick uncertainty in the 449 * firing of the timer. The bias will give us exactly the 450 * 1.5 tick we need. But, because the bias is 451 * statistical, we have to test that we don't drop below 452 * the minimum feasible timer (which is 2 ticks). 453 * This version of the macro adapted from a paper by Lawrence 454 * Brakmo and Larry Peterson which outlines a problem caused 455 * by insufficient precision in the original implementation, 456 * which results in inappropriately large RTO values for very 457 * fast networks. 458 */ 459 #define TCP_REXMTVAL(tp) \ 460 max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \ 461 + (tp)->t_rttvar) >> TCP_DELTA_SHIFT) 462 463 /* 464 * TCP statistics. 465 * Many of these should be kept per connection, 466 * but that's inconvenient at the moment. 467 */ 468 struct tcpstat { 469 uint64_t tcps_connattempt; /* connections initiated */ 470 uint64_t tcps_accepts; /* connections accepted */ 471 uint64_t tcps_connects; /* connections established */ 472 uint64_t tcps_drops; /* connections dropped */ 473 uint64_t tcps_conndrops; /* embryonic connections dropped */ 474 uint64_t tcps_minmssdrops; /* average minmss too low drops */ 475 uint64_t tcps_closed; /* conn. closed (includes drops) */ 476 uint64_t tcps_segstimed; /* segs where we tried to get rtt */ 477 uint64_t tcps_rttupdated; /* times we succeeded */ 478 uint64_t tcps_delack; /* delayed acks sent */ 479 uint64_t tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ 480 uint64_t tcps_rexmttimeo; /* retransmit timeouts */ 481 uint64_t tcps_persisttimeo; /* persist timeouts */ 482 uint64_t tcps_keeptimeo; /* keepalive timeouts */ 483 uint64_t tcps_keepprobe; /* keepalive probes sent */ 484 uint64_t tcps_keepdrops; /* connections dropped in keepalive */ 485 486 uint64_t tcps_sndtotal; /* total packets sent */ 487 uint64_t tcps_sndpack; /* data packets sent */ 488 uint64_t tcps_sndbyte; /* data bytes sent */ 489 uint64_t tcps_sndrexmitpack; /* data packets retransmitted */ 490 uint64_t tcps_sndrexmitbyte; /* data bytes retransmitted */ 491 uint64_t tcps_sndrexmitbad; /* unnecessary packet retransmissions */ 492 uint64_t tcps_sndacks; /* ack-only packets sent */ 493 uint64_t tcps_sndprobe; /* window probes sent */ 494 uint64_t tcps_sndurg; /* packets sent with URG only */ 495 uint64_t tcps_sndwinup; /* window update-only packets sent */ 496 uint64_t tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ 497 498 uint64_t tcps_rcvtotal; /* total packets received */ 499 uint64_t tcps_rcvpack; /* packets received in sequence */ 500 uint64_t tcps_rcvbyte; /* bytes received in sequence */ 501 uint64_t tcps_rcvbadsum; /* packets received with ccksum errs */ 502 uint64_t tcps_rcvbadoff; /* packets received with bad offset */ 503 uint64_t tcps_rcvreassfull; /* packets dropped for no reass space */ 504 uint64_t tcps_rcvshort; /* packets received too short */ 505 uint64_t tcps_rcvduppack; /* duplicate-only packets received */ 506 uint64_t tcps_rcvdupbyte; /* duplicate-only bytes received */ 507 uint64_t tcps_rcvpartduppack; /* packets with some duplicate data */ 508 uint64_t tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ 509 uint64_t tcps_rcvoopack; /* out-of-order packets received */ 510 uint64_t tcps_rcvoobyte; /* out-of-order bytes received */ 511 uint64_t tcps_rcvpackafterwin; /* packets with data after window */ 512 uint64_t tcps_rcvbyteafterwin; /* bytes rcvd after window */ 513 uint64_t tcps_rcvafterclose; /* packets rcvd after "close" */ 514 uint64_t tcps_rcvwinprobe; /* rcvd window probe packets */ 515 uint64_t tcps_rcvdupack; /* rcvd duplicate acks */ 516 uint64_t tcps_rcvacktoomuch; /* rcvd acks for unsent data */ 517 uint64_t tcps_rcvackpack; /* rcvd ack packets */ 518 uint64_t tcps_rcvackbyte; /* bytes acked by rcvd acks */ 519 uint64_t tcps_rcvwinupd; /* rcvd window update packets */ 520 uint64_t tcps_pawsdrop; /* segments dropped due to PAWS */ 521 uint64_t tcps_predack; /* times hdr predict ok for acks */ 522 uint64_t tcps_preddat; /* times hdr predict ok for data pkts */ 523 uint64_t tcps_pcbcachemiss; 524 uint64_t tcps_cachedrtt; /* times cached RTT in route updated */ 525 uint64_t tcps_cachedrttvar; /* times cached rttvar updated */ 526 uint64_t tcps_cachedssthresh; /* times cached ssthresh updated */ 527 uint64_t tcps_usedrtt; /* times RTT initialized from route */ 528 uint64_t tcps_usedrttvar; /* times RTTVAR initialized from rt */ 529 uint64_t tcps_usedssthresh; /* times ssthresh initialized from rt*/ 530 uint64_t tcps_persistdrop; /* timeout in persist state */ 531 uint64_t tcps_badsyn; /* bogus SYN, e.g. premature ACK */ 532 uint64_t tcps_mturesent; /* resends due to MTU discovery */ 533 uint64_t tcps_listendrop; /* listen queue overflows */ 534 uint64_t tcps_badrst; /* ignored RSTs in the window */ 535 536 uint64_t tcps_sc_added; /* entry added to syncache */ 537 uint64_t tcps_sc_retransmitted; /* syncache entry was retransmitted */ 538 uint64_t tcps_sc_dupsyn; /* duplicate SYN packet */ 539 uint64_t tcps_sc_dropped; /* could not reply to packet */ 540 uint64_t tcps_sc_completed; /* successful extraction of entry */ 541 uint64_t tcps_sc_bucketoverflow;/* syncache per-bucket limit hit */ 542 uint64_t tcps_sc_cacheoverflow; /* syncache cache limit hit */ 543 uint64_t tcps_sc_reset; /* RST removed entry from syncache */ 544 uint64_t tcps_sc_stale; /* timed out or listen socket gone */ 545 uint64_t tcps_sc_aborted; /* syncache entry aborted */ 546 uint64_t tcps_sc_badack; /* removed due to bad ACK */ 547 uint64_t tcps_sc_unreach; /* ICMP unreachable received */ 548 uint64_t tcps_sc_zonefail; /* zalloc() failed */ 549 uint64_t tcps_sc_sendcookie; /* SYN cookie sent */ 550 uint64_t tcps_sc_recvcookie; /* SYN cookie received */ 551 552 uint64_t tcps_hc_added; /* entry added to hostcache */ 553 uint64_t tcps_hc_bucketoverflow;/* hostcache per bucket limit hit */ 554 555 uint64_t tcps_finwait2_drops; /* Drop FIN_WAIT_2 connection after time limit */ 556 557 /* SACK related stats */ 558 uint64_t tcps_sack_recovery_episode; /* SACK recovery episodes */ 559 uint64_t tcps_sack_rexmits; /* SACK rexmit segments */ 560 uint64_t tcps_sack_rexmit_bytes; /* SACK rexmit bytes */ 561 uint64_t tcps_sack_rcv_blocks; /* SACK blocks (options) received */ 562 uint64_t tcps_sack_send_blocks; /* SACK blocks (options) sent */ 563 uint64_t tcps_sack_sboverflow; /* times scoreboard overflowed */ 564 565 /* ECN related stats */ 566 uint64_t tcps_ecn_ce; /* ECN Congestion Experienced */ 567 uint64_t tcps_ecn_ect0; /* ECN Capable Transport */ 568 uint64_t tcps_ecn_ect1; /* ECN Capable Transport */ 569 uint64_t tcps_ecn_shs; /* ECN successful handshakes */ 570 uint64_t tcps_ecn_rcwnd; /* # times ECN reduced the cwnd */ 571 572 /* TCP_SIGNATURE related stats */ 573 uint64_t tcps_sig_rcvgoodsig; /* Total matching signature received */ 574 uint64_t tcps_sig_rcvbadsig; /* Total bad signature received */ 575 uint64_t tcps_sig_err_buildsig; /* Failed to make signature */ 576 uint64_t tcps_sig_err_sigopt; /* No signature expected by socket */ 577 uint64_t tcps_sig_err_nosigopt; /* No signature provided by segment */ 578 579 /* Path MTU Discovery Black Hole Detection related stats */ 580 uint64_t tcps_pmtud_blackhole_activated; /* Black Hole Count */ 581 uint64_t tcps_pmtud_blackhole_activated_min_mss; /* BH at min MSS Count */ 582 uint64_t tcps_pmtud_blackhole_failed; /* Black Hole Failure Count */ 583 584 uint64_t _pad[12]; /* 6 UTO, 6 TBD */ 585 }; 586 587 #define tcps_rcvmemdrop tcps_rcvreassfull /* compat */ 588 589 #ifdef _KERNEL 590 #define TI_UNLOCKED 1 591 #define TI_RLOCKED 2 592 #include <sys/counter.h> 593 594 VNET_PCPUSTAT_DECLARE(struct tcpstat, tcpstat); /* tcp statistics */ 595 /* 596 * In-kernel consumers can use these accessor macros directly to update 597 * stats. 598 */ 599 #define TCPSTAT_ADD(name, val) \ 600 VNET_PCPUSTAT_ADD(struct tcpstat, tcpstat, name, (val)) 601 #define TCPSTAT_INC(name) TCPSTAT_ADD(name, 1) 602 603 /* 604 * Kernel module consumers must use this accessor macro. 605 */ 606 void kmod_tcpstat_inc(int statnum); 607 #define KMOD_TCPSTAT_INC(name) \ 608 kmod_tcpstat_inc(offsetof(struct tcpstat, name) / sizeof(uint64_t)) 609 610 /* 611 * Running TCP connection count by state. 612 */ 613 VNET_DECLARE(counter_u64_t, tcps_states[TCP_NSTATES]); 614 #define V_tcps_states VNET(tcps_states) 615 #define TCPSTATES_INC(state) counter_u64_add(V_tcps_states[state], 1) 616 #define TCPSTATES_DEC(state) counter_u64_add(V_tcps_states[state], -1) 617 618 /* 619 * TCP specific helper hook point identifiers. 620 */ 621 #define HHOOK_TCP_EST_IN 0 622 #define HHOOK_TCP_EST_OUT 1 623 #define HHOOK_TCP_LAST HHOOK_TCP_EST_OUT 624 625 struct tcp_hhook_data { 626 struct tcpcb *tp; 627 struct tcphdr *th; 628 struct tcpopt *to; 629 uint32_t len; 630 int tso; 631 tcp_seq curack; 632 }; 633 #endif 634 635 /* 636 * TCB structure exported to user-land via sysctl(3). 637 * 638 * Fields prefixed with "xt_" are unique to the export structure, and fields 639 * with "t_" or other prefixes match corresponding fields of 'struct tcpcb'. 640 * 641 * Legend: 642 * (s) - used by userland utilities in src 643 * (p) - used by utilities in ports 644 * (3) - is known to be used by third party software not in ports 645 * (n) - no known usage 646 * 647 * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been 648 * included. Not all of our clients do. 649 */ 650 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_) 651 struct xtcpcb { 652 size_t xt_len; /* length of this structure */ 653 struct xinpcb xt_inp; 654 char xt_stack[TCP_FUNCTION_NAME_LEN_MAX]; /* (s) */ 655 int64_t spare64[8]; 656 int32_t t_state; /* (s,p) */ 657 uint32_t t_flags; /* (s,p) */ 658 int32_t t_sndzerowin; /* (s) */ 659 int32_t t_sndrexmitpack; /* (s) */ 660 int32_t t_rcvoopack; /* (s) */ 661 int32_t t_rcvtime; /* (s) */ 662 int32_t tt_rexmt; /* (s) */ 663 int32_t tt_persist; /* (s) */ 664 int32_t tt_keep; /* (s) */ 665 int32_t tt_2msl; /* (s) */ 666 int32_t tt_delack; /* (s) */ 667 int32_t spare32[32]; 668 } __aligned(8); 669 #ifdef _KERNEL 670 void tcp_inptoxtp(const struct inpcb *, struct xtcpcb *); 671 #endif 672 #endif 673 674 /* 675 * Identifiers for TCP sysctl nodes 676 */ 677 #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */ 678 #define TCPCTL_MSSDFLT 3 /* MSS default */ 679 #define TCPCTL_STATS 4 /* statistics */ 680 #define TCPCTL_RTTDFLT 5 /* default RTT estimate */ 681 #define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */ 682 #define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */ 683 #define TCPCTL_SENDSPACE 8 /* send buffer space */ 684 #define TCPCTL_RECVSPACE 9 /* receive buffer space */ 685 #define TCPCTL_KEEPINIT 10 /* timeout for establishing syn */ 686 #define TCPCTL_PCBLIST 11 /* list of all outstanding PCBs */ 687 #define TCPCTL_DELACKTIME 12 /* time before sending delayed ACK */ 688 #define TCPCTL_V6MSSDFLT 13 /* MSS default for IPv6 */ 689 #define TCPCTL_SACK 14 /* Selective Acknowledgement,rfc 2018 */ 690 #define TCPCTL_DROP 15 /* drop tcp connection */ 691 #define TCPCTL_STATES 16 /* connection counts by TCP state */ 692 693 #ifdef _KERNEL 694 #ifdef SYSCTL_DECL 695 SYSCTL_DECL(_net_inet_tcp); 696 SYSCTL_DECL(_net_inet_tcp_sack); 697 MALLOC_DECLARE(M_TCPLOG); 698 #endif 699 700 extern int tcp_log_in_vain; 701 702 /* 703 * Global TCP tunables shared between different stacks. 704 * Please keep the list sorted. 705 */ 706 VNET_DECLARE(int, drop_synfin); 707 VNET_DECLARE(int, path_mtu_discovery); 708 VNET_DECLARE(int, tcp_abc_l_var); 709 VNET_DECLARE(int, tcp_autorcvbuf_inc); 710 VNET_DECLARE(int, tcp_autorcvbuf_max); 711 VNET_DECLARE(int, tcp_autosndbuf_inc); 712 VNET_DECLARE(int, tcp_autosndbuf_max); 713 VNET_DECLARE(int, tcp_delack_enabled); 714 VNET_DECLARE(int, tcp_do_autorcvbuf); 715 VNET_DECLARE(int, tcp_do_autosndbuf); 716 VNET_DECLARE(int, tcp_do_ecn); 717 VNET_DECLARE(int, tcp_do_rfc1323); 718 VNET_DECLARE(int, tcp_do_rfc3042); 719 VNET_DECLARE(int, tcp_do_rfc3390); 720 VNET_DECLARE(int, tcp_do_rfc3465); 721 VNET_DECLARE(int, tcp_do_rfc6675_pipe); 722 VNET_DECLARE(int, tcp_do_sack); 723 VNET_DECLARE(int, tcp_do_tso); 724 VNET_DECLARE(int, tcp_ecn_maxretries); 725 VNET_DECLARE(int, tcp_initcwnd_segments); 726 VNET_DECLARE(int, tcp_insecure_rst); 727 VNET_DECLARE(int, tcp_insecure_syn); 728 VNET_DECLARE(int, tcp_minmss); 729 VNET_DECLARE(int, tcp_mssdflt); 730 VNET_DECLARE(int, tcp_recvspace); 731 VNET_DECLARE(int, tcp_sack_globalholes); 732 VNET_DECLARE(int, tcp_sack_globalmaxholes); 733 VNET_DECLARE(int, tcp_sack_maxholes); 734 VNET_DECLARE(int, tcp_sc_rst_sock_fail); 735 VNET_DECLARE(int, tcp_sendspace); 736 VNET_DECLARE(struct inpcbhead, tcb); 737 VNET_DECLARE(struct inpcbinfo, tcbinfo); 738 739 #define V_drop_synfin VNET(drop_synfin) 740 #define V_path_mtu_discovery VNET(path_mtu_discovery) 741 #define V_tcb VNET(tcb) 742 #define V_tcbinfo VNET(tcbinfo) 743 #define V_tcp_abc_l_var VNET(tcp_abc_l_var) 744 #define V_tcp_autorcvbuf_inc VNET(tcp_autorcvbuf_inc) 745 #define V_tcp_autorcvbuf_max VNET(tcp_autorcvbuf_max) 746 #define V_tcp_autosndbuf_inc VNET(tcp_autosndbuf_inc) 747 #define V_tcp_autosndbuf_max VNET(tcp_autosndbuf_max) 748 #define V_tcp_delack_enabled VNET(tcp_delack_enabled) 749 #define V_tcp_do_autorcvbuf VNET(tcp_do_autorcvbuf) 750 #define V_tcp_do_autosndbuf VNET(tcp_do_autosndbuf) 751 #define V_tcp_do_ecn VNET(tcp_do_ecn) 752 #define V_tcp_do_rfc1323 VNET(tcp_do_rfc1323) 753 #define V_tcp_do_rfc3042 VNET(tcp_do_rfc3042) 754 #define V_tcp_do_rfc3390 VNET(tcp_do_rfc3390) 755 #define V_tcp_do_rfc3465 VNET(tcp_do_rfc3465) 756 #define V_tcp_do_rfc6675_pipe VNET(tcp_do_rfc6675_pipe) 757 #define V_tcp_do_sack VNET(tcp_do_sack) 758 #define V_tcp_do_tso VNET(tcp_do_tso) 759 #define V_tcp_ecn_maxretries VNET(tcp_ecn_maxretries) 760 #define V_tcp_initcwnd_segments VNET(tcp_initcwnd_segments) 761 #define V_tcp_insecure_rst VNET(tcp_insecure_rst) 762 #define V_tcp_insecure_syn VNET(tcp_insecure_syn) 763 #define V_tcp_minmss VNET(tcp_minmss) 764 #define V_tcp_mssdflt VNET(tcp_mssdflt) 765 #define V_tcp_recvspace VNET(tcp_recvspace) 766 #define V_tcp_sack_globalholes VNET(tcp_sack_globalholes) 767 #define V_tcp_sack_globalmaxholes VNET(tcp_sack_globalmaxholes) 768 #define V_tcp_sack_maxholes VNET(tcp_sack_maxholes) 769 #define V_tcp_sc_rst_sock_fail VNET(tcp_sc_rst_sock_fail) 770 #define V_tcp_sendspace VNET(tcp_sendspace) 771 772 #ifdef TCP_HHOOK 773 VNET_DECLARE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST + 1]); 774 #define V_tcp_hhh VNET(tcp_hhh) 775 #endif 776 777 int tcp_addoptions(struct tcpopt *, u_char *); 778 int tcp_ccalgounload(struct cc_algo *unload_algo); 779 struct tcpcb * 780 tcp_close(struct tcpcb *); 781 void tcp_discardcb(struct tcpcb *); 782 void tcp_twstart(struct tcpcb *); 783 void tcp_twclose(struct tcptw *, int); 784 void tcp_ctlinput(int, struct sockaddr *, void *); 785 int tcp_ctloutput(struct socket *, struct sockopt *); 786 struct tcpcb * 787 tcp_drop(struct tcpcb *, int); 788 void tcp_drain(void); 789 void tcp_init(void); 790 void tcp_fini(void *); 791 char *tcp_log_addrs(struct in_conninfo *, struct tcphdr *, void *, 792 const void *); 793 char *tcp_log_vain(struct in_conninfo *, struct tcphdr *, void *, 794 const void *); 795 int tcp_reass(struct tcpcb *, struct tcphdr *, int *, struct mbuf *); 796 void tcp_reass_global_init(void); 797 void tcp_reass_flush(struct tcpcb *); 798 void tcp_dooptions(struct tcpopt *, u_char *, int, int); 799 void tcp_dropwithreset(struct mbuf *, struct tcphdr *, 800 struct tcpcb *, int, int); 801 void tcp_pulloutofband(struct socket *, 802 struct tcphdr *, struct mbuf *, int); 803 void tcp_xmit_timer(struct tcpcb *, int); 804 void tcp_newreno_partial_ack(struct tcpcb *, struct tcphdr *); 805 void cc_ack_received(struct tcpcb *tp, struct tcphdr *th, 806 uint16_t nsegs, uint16_t type); 807 void cc_conn_init(struct tcpcb *tp); 808 void cc_post_recovery(struct tcpcb *tp, struct tcphdr *th); 809 void cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type); 810 #ifdef TCP_HHOOK 811 void hhook_run_tcp_est_in(struct tcpcb *tp, 812 struct tcphdr *th, struct tcpopt *to); 813 #endif 814 815 int tcp_input(struct mbuf **, int *, int); 816 int tcp_autorcvbuf(struct mbuf *, struct tcphdr *, struct socket *, 817 struct tcpcb *, int); 818 void tcp_do_segment(struct mbuf *, struct tcphdr *, 819 struct socket *, struct tcpcb *, int, int, uint8_t, 820 int); 821 822 int register_tcp_functions(struct tcp_function_block *blk, int wait); 823 int register_tcp_functions_as_names(struct tcp_function_block *blk, 824 int wait, const char *names[], int *num_names); 825 int register_tcp_functions_as_name(struct tcp_function_block *blk, 826 const char *name, int wait); 827 int deregister_tcp_functions(struct tcp_function_block *blk); 828 struct tcp_function_block *find_and_ref_tcp_functions(struct tcp_function_set *fs); 829 struct tcp_function_block *find_and_ref_tcp_fb(struct tcp_function_block *blk); 830 int tcp_default_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp); 831 832 uint32_t tcp_maxmtu(struct in_conninfo *, struct tcp_ifcap *); 833 uint32_t tcp_maxmtu6(struct in_conninfo *, struct tcp_ifcap *); 834 u_int tcp_maxseg(const struct tcpcb *); 835 void tcp_mss_update(struct tcpcb *, int, int, struct hc_metrics_lite *, 836 struct tcp_ifcap *); 837 void tcp_mss(struct tcpcb *, int); 838 int tcp_mssopt(struct in_conninfo *); 839 struct inpcb * 840 tcp_drop_syn_sent(struct inpcb *, int); 841 struct tcpcb * 842 tcp_newtcpcb(struct inpcb *); 843 int tcp_output(struct tcpcb *); 844 void tcp_state_change(struct tcpcb *, int); 845 void tcp_respond(struct tcpcb *, void *, 846 struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int); 847 void tcp_tw_init(void); 848 #ifdef VIMAGE 849 void tcp_tw_destroy(void); 850 #endif 851 void tcp_tw_zone_change(void); 852 int tcp_twcheck(struct inpcb *, struct tcpopt *, struct tcphdr *, 853 struct mbuf *, int); 854 void tcp_setpersist(struct tcpcb *); 855 void tcp_slowtimo(void); 856 struct tcptemp * 857 tcpip_maketemplate(struct inpcb *); 858 void tcpip_fillheaders(struct inpcb *, void *, void *); 859 void tcp_timer_activate(struct tcpcb *, uint32_t, u_int); 860 int tcp_timer_active(struct tcpcb *, uint32_t); 861 void tcp_timer_stop(struct tcpcb *, uint32_t); 862 void tcp_trace(short, short, struct tcpcb *, void *, struct tcphdr *, int); 863 /* 864 * All tcp_hc_* functions are IPv4 and IPv6 (via in_conninfo) 865 */ 866 void tcp_hc_init(void); 867 #ifdef VIMAGE 868 void tcp_hc_destroy(void); 869 #endif 870 void tcp_hc_get(struct in_conninfo *, struct hc_metrics_lite *); 871 uint32_t tcp_hc_getmtu(struct in_conninfo *); 872 void tcp_hc_updatemtu(struct in_conninfo *, uint32_t); 873 void tcp_hc_update(struct in_conninfo *, struct hc_metrics_lite *); 874 875 extern struct pr_usrreqs tcp_usrreqs; 876 tcp_seq tcp_new_isn(struct tcpcb *); 877 878 int tcp_sack_doack(struct tcpcb *, struct tcpopt *, tcp_seq); 879 void tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend); 880 void tcp_clean_sackreport(struct tcpcb *tp); 881 void tcp_sack_adjust(struct tcpcb *tp); 882 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt); 883 void tcp_sack_partialack(struct tcpcb *, struct tcphdr *); 884 void tcp_free_sackholes(struct tcpcb *tp); 885 int tcp_newreno(struct tcpcb *, struct tcphdr *); 886 int tcp_compute_pipe(struct tcpcb *); 887 888 static inline void 889 tcp_fields_to_host(struct tcphdr *th) 890 { 891 892 th->th_seq = ntohl(th->th_seq); 893 th->th_ack = ntohl(th->th_ack); 894 th->th_win = ntohs(th->th_win); 895 th->th_urp = ntohs(th->th_urp); 896 } 897 898 static inline void 899 tcp_fields_to_net(struct tcphdr *th) 900 { 901 902 th->th_seq = htonl(th->th_seq); 903 th->th_ack = htonl(th->th_ack); 904 th->th_win = htons(th->th_win); 905 th->th_urp = htons(th->th_urp); 906 } 907 #endif /* _KERNEL */ 908 909 #endif /* _NETINET_TCP_VAR_H_ */ 910