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