bsd/netinet/tcp_var.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1982, 1986, 1993, 1994, 1995
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  *
  55  *      @(#)tcp_var.h   8.4 (Berkeley) 5/24/95
  56  * $FreeBSD: src/sys/netinet/tcp_var.h,v 1.56.2.8 2001/08/22 00:59:13 silby Exp $
  57  */
  58
  59 #ifndef _NETINET_TCP_VAR_H_
  60 #define _NETINET_TCP_VAR_H_
  61 #include <sys/appleapiopts.h>
  62 #include <sys/queue.h>
  63 #include <netinet/in_pcb.h>
  64 #include <netinet/tcp_timer.h>
  65
  66 #ifdef KERNEL_PRIVATE
  67
  68 #define N_TIME_WAIT_SLOTS   128                /* must be power of 2 */
  69
  70 /*
  71  * Kernel variables for tcp.
  72  */
  73
  74 /* TCP segment queue entry */
  75 struct tseg_qent {
  76         LIST_ENTRY(tseg_qent) tqe_q;
  77         int     tqe_len;                /* TCP segment data length */
  78         struct  tcphdr *tqe_th;         /* a pointer to tcp header */
  79         struct  mbuf    *tqe_m;         /* mbuf contains packet */
  80 };
  81 LIST_HEAD(tsegqe_head, tseg_qent);
  82 extern int      tcp_reass_maxseg;
  83 extern int      tcp_reass_qsize;
  84 #ifdef MALLOC_DECLARE
  85 MALLOC_DECLARE(M_TSEGQ);
  86 #endif
  87
  88 struct tcptemp {
  89         u_char  tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
  90         struct  tcphdr tt_t;
  91 };
  92
  93 #define tcp6cb          tcpcb  /* for KAME src sync over BSD*'s */
  94
  95 /*
  96  * Tcp control block, one per tcp; fields:
  97  * Organized for 16 byte cacheline efficiency.
  98  */
  99 struct tcpcb {
 100         struct  tsegqe_head t_segq;
 101         int     t_dupacks;              /* consecutive dup acks recd */
 102         struct  tcptemp *unused;        /* unused now: was t_template */
 103
 104         int     t_timer[TCPT_NTIMERS];  /* tcp timers */
 105
 106         struct  inpcb *t_inpcb;         /* back pointer to internet pcb */
 107         int     t_state;                /* state of this connection */
 108         u_int   t_flags;
 109 #define TF_ACKNOW       0x00001         /* ack peer immediately */
 110 #define TF_DELACK       0x00002         /* ack, but try to delay it */
 111 #define TF_NODELAY      0x00004         /* don't delay packets to coalesce */
 112 #define TF_NOOPT        0x00008         /* don't use tcp options */
 113 #define TF_SENTFIN      0x00010         /* have sent FIN */
 114 #define TF_REQ_SCALE    0x00020         /* have/will request window scaling */
 115 #define TF_RCVD_SCALE   0x00040         /* other side has requested scaling */
 116 #define TF_REQ_TSTMP    0x00080         /* have/will request timestamps */
 117 #define TF_RCVD_TSTMP   0x00100         /* a timestamp was received in SYN */
 118 #define TF_SACK_PERMIT  0x00200         /* other side said I could SACK */
 119 #define TF_NEEDSYN      0x00400         /* send SYN (implicit state) */
 120 #define TF_NEEDFIN      0x00800         /* send FIN (implicit state) */
 121 #define TF_NOPUSH       0x01000         /* don't push */
 122 #define TF_REQ_CC       0x02000         /* have/will request CC */
 123 #define TF_RCVD_CC      0x04000         /* a CC was received in SYN */
 124 #define TF_SENDCCNEW    0x08000         /* send CCnew instead of CC in SYN */
 125 #define TF_MORETOCOME   0x10000         /* More data to be appended to sock */
 126 #define TF_LQ_OVERFLOW  0x20000         /* listen queue overflow */
 127 #define TF_RXWIN0SENT   0x40000         /* sent a receiver win 0 in response */
 128 #define TF_SLOWLINK     0x80000         /* route is a on a modem speed link */
 129
 130         int     t_force;                /* 1 if forcing out a byte */
 131
 132         tcp_seq snd_una;                /* send unacknowledged */
 133         tcp_seq snd_max;                /* highest sequence number sent;
 134                                          * used to recognize retransmits
 135                                          */
 136         tcp_seq snd_nxt;                /* send next */
 137         tcp_seq snd_up;                 /* send urgent pointer */
 138
 139         tcp_seq snd_wl1;                /* window update seg seq number */
 140         tcp_seq snd_wl2;                /* window update seg ack number */
 141         tcp_seq iss;                    /* initial send sequence number */
 142         tcp_seq irs;                    /* initial receive sequence number */
 143
 144         tcp_seq rcv_nxt;                /* receive next */
 145         tcp_seq rcv_adv;                /* advertised window */
 146         u_long  rcv_wnd;                /* receive window */
 147         tcp_seq rcv_up;                 /* receive urgent pointer */
 148
 149         u_long  snd_wnd;                /* send window */
 150         u_long  snd_cwnd;               /* congestion-controlled window */
 151         u_long  snd_ssthresh;           /* snd_cwnd size threshold for
 152                                          * for slow start exponential to
 153                                          * linear switch
 154                                          */
 155         u_int   t_maxopd;               /* mss plus options */
 156
 157         u_long  t_rcvtime;              /* inactivity time */
 158         u_long  t_starttime;            /* time connection was established */
 159         int     t_rtttime;              /* round trip time */
 160         tcp_seq t_rtseq;                /* sequence number being timed */
 161
 162         int     t_rxtcur;               /* current retransmit value (ticks) */
 163         u_int   t_maxseg;               /* maximum segment size */
 164         int     t_srtt;                 /* smoothed round-trip time */
 165         int     t_rttvar;               /* variance in round-trip time */
 166
 167         int     t_rxtshift;             /* log(2) of rexmt exp. backoff */
 168         u_int   t_rttmin;               /* minimum rtt allowed */
 169         u_long  t_rttupdated;           /* number of times rtt sampled */
 170         u_long  max_sndwnd;             /* largest window peer has offered */
 171
 172         int     t_softerror;            /* possible error not yet reported */
 173 /* out-of-band data */
 174         char    t_oobflags;             /* have some */
 175         char    t_iobc;                 /* input character */
 176 #define TCPOOB_HAVEDATA 0x01
 177 #define TCPOOB_HADDATA  0x02
 178 /* RFC 1323 variables */
 179         u_char  snd_scale;              /* window scaling for send window */
 180         u_char  rcv_scale;              /* window scaling for recv window */
 181         u_char  request_r_scale;        /* pending window scaling */
 182         u_char  requested_s_scale;
 183         u_long  ts_recent;              /* timestamp echo data */
 184
 185         u_long  ts_recent_age;          /* when last updated */
 186         tcp_seq last_ack_sent;
 187 /* RFC 1644 variables */
 188         tcp_cc  cc_send;                /* send connection count */
 189         tcp_cc  cc_recv;                /* receive connection count */
 190         tcp_seq snd_recover;    /* for use in NewReno Fast Recovery */
 191 /* experimental */
 192         u_long  snd_cwnd_prev;          /* cwnd prior to retransmit */
 193         u_long  snd_ssthresh_prev;      /* ssthresh prior to retransmit */
 194         u_long  t_badrxtwin;            /* window for retransmit recovery */
 195
 196         int     t_keepidle;             /* keepalive idle timer (override global if > 0) */
 197         int     t_lastchain;            /* amount of packets chained last time around */
 198
 199 /* 3529618 MSS overload prevention */
 200         u_long  rcv_reset;
 201         u_long  rcv_pps;
 202         u_long  rcv_byps;
 203         tcp_seq snd_high;               /* for use in NewReno Fast Recovery */
 204         tcp_seq snd_high_prev;  /* snd_high prior to retransmit */
 205
 206 };
 207
 208 /*
 209  * Structure to hold TCP options that are only used during segment
 210  * processing (in tcp_input), but not held in the tcpcb.
 211  * It's basically used to reduce the number of parameters
 212  * to tcp_dooptions.
 213  */
 214 struct tcpopt {
 215         u_long  to_flag;                /* which options are present */
 216 #define TOF_TS          0x0001          /* timestamp */
 217 #define TOF_CC          0x0002          /* CC and CCnew are exclusive */
 218 #define TOF_CCNEW       0x0004
 219 #define TOF_CCECHO      0x0008
 220         u_long  to_tsval;
 221         u_long  to_tsecr;
 222         tcp_cc  to_cc;          /* holds CC or CCnew */
 223         tcp_cc  to_ccecho;
 224         u_short         reserved;               /* unused now: was to_maxseg */
 225 };
 226
 227 /*
 228  * The TAO cache entry which is stored in the protocol family specific
 229  * portion of the route metrics.
 230  */
 231 struct rmxp_tao {
 232         tcp_cc  tao_cc;                 /* latest CC in valid SYN */
 233         tcp_cc  tao_ccsent;             /* latest CC sent to peer */
 234         u_short tao_mssopt;             /* peer's cached MSS */
 235 #ifdef notyet
 236         u_short tao_flags;              /* cache status flags */
 237 #define TAOF_DONT       0x0001          /* peer doesn't understand rfc1644 */
 238 #define TAOF_OK         0x0002          /* peer does understand rfc1644 */
 239 #define TAOF_UNDEF      0               /* we don't know yet */
 240 #endif /* notyet */
 241 };
 242 #define rmx_taop(r)     ((struct rmxp_tao *)(r).rmx_filler)
 243
 244 #define intotcpcb(ip)   ((struct tcpcb *)(ip)->inp_ppcb)
 245 #define sototcpcb(so)   (intotcpcb(sotoinpcb(so)))
 246
 247 /*
 248  * The smoothed round-trip time and estimated variance
 249  * are stored as fixed point numbers scaled by the values below.
 250  * For convenience, these scales are also used in smoothing the average
 251  * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
 252  * With these scales, srtt has 3 bits to the right of the binary point,
 253  * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
 254  * binary point, and is smoothed with an ALPHA of 0.75.
 255  */
 256 #define TCP_RTT_SCALE           32      /* multiplier for srtt; 3 bits frac. */
 257 #define TCP_RTT_SHIFT           5       /* shift for srtt; 3 bits frac. */
 258 #define TCP_RTTVAR_SCALE        16      /* multiplier for rttvar; 2 bits */
 259 #define TCP_RTTVAR_SHIFT        4       /* shift for rttvar; 2 bits */
 260 #define TCP_DELTA_SHIFT         2       /* see tcp_input.c */
 261
 262 /*
 263  * The initial retransmission should happen at rtt + 4 * rttvar.
 264  * Because of the way we do the smoothing, srtt and rttvar
 265  * will each average +1/2 tick of bias.  When we compute
 266  * the retransmit timer, we want 1/2 tick of rounding and
 267  * 1 extra tick because of +-1/2 tick uncertainty in the
 268  * firing of the timer.  The bias will give us exactly the
 269  * 1.5 tick we need.  But, because the bias is
 270  * statistical, we have to test that we don't drop below
 271  * the minimum feasible timer (which is 2 ticks).
 272  * This version of the macro adapted from a paper by Lawrence
 273  * Brakmo and Larry Peterson which outlines a problem caused
 274  * by insufficient precision in the original implementation,
 275  * which results in inappropriately large RTO values for very
 276  * fast networks.
 277  */
 278 #define TCP_REXMTVAL(tp) \
 279         max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
 280           + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
 281
 282 /*
 283  * Jaguar compatible TCP control block, for xtcpcb
 284  * Does not have the old fields
 285  */
 286 struct otcpcb {
 287 #else
 288 struct tseg_qent;
 289 LIST_HEAD(tsegqe_head, tseg_qent);
 290
 291 struct tcpcb {
 292 #endif /* KERNEL_PRIVATE */
 293         struct  tsegqe_head t_segq;
 294         int     t_dupacks;              /* consecutive dup acks recd */
 295         struct  tcptemp *unused;        /* unused now: was t_template */
 296
 297         int     t_timer[TCPT_NTIMERS];  /* tcp timers */
 298
 299         struct  inpcb *t_inpcb;         /* back pointer to internet pcb */
 300         int     t_state;                /* state of this connection */
 301         u_int   t_flags;
 302 #define TF_ACKNOW       0x00001         /* ack peer immediately */
 303 #define TF_DELACK       0x00002         /* ack, but try to delay it */
 304 #define TF_NODELAY      0x00004         /* don't delay packets to coalesce */
 305 #define TF_NOOPT        0x00008         /* don't use tcp options */
 306 #define TF_SENTFIN      0x00010         /* have sent FIN */
 307 #define TF_REQ_SCALE    0x00020         /* have/will request window scaling */
 308 #define TF_RCVD_SCALE   0x00040         /* other side has requested scaling */
 309 #define TF_REQ_TSTMP    0x00080         /* have/will request timestamps */
 310 #define TF_RCVD_TSTMP   0x00100         /* a timestamp was received in SYN */
 311 #define TF_SACK_PERMIT  0x00200         /* other side said I could SACK */
 312 #define TF_NEEDSYN      0x00400         /* send SYN (implicit state) */
 313 #define TF_NEEDFIN      0x00800         /* send FIN (implicit state) */
 314 #define TF_NOPUSH       0x01000         /* don't push */
 315 #define TF_REQ_CC       0x02000         /* have/will request CC */
 316 #define TF_RCVD_CC      0x04000         /* a CC was received in SYN */
 317 #define TF_SENDCCNEW    0x08000         /* send CCnew instead of CC in SYN */
 318 #define TF_MORETOCOME   0x10000         /* More data to be appended to sock */
 319 #define TF_LQ_OVERFLOW  0x20000         /* listen queue overflow */
 320 #define TF_RXWIN0SENT   0x40000         /* sent a receiver win 0 in response */
 321 #define TF_SLOWLINK     0x80000         /* route is a on a modem speed link */
 322
 323         int     t_force;                /* 1 if forcing out a byte */
 324
 325         tcp_seq snd_una;                /* send unacknowledged */
 326         tcp_seq snd_max;                /* highest sequence number sent;
 327                                          * used to recognize retransmits
 328                                          */
 329         tcp_seq snd_nxt;                /* send next */
 330         tcp_seq snd_up;                 /* send urgent pointer */
 331
 332         tcp_seq snd_wl1;                /* window update seg seq number */
 333         tcp_seq snd_wl2;                /* window update seg ack number */
 334         tcp_seq iss;                    /* initial send sequence number */
 335         tcp_seq irs;                    /* initial receive sequence number */
 336
 337         tcp_seq rcv_nxt;                /* receive next */
 338         tcp_seq rcv_adv;                /* advertised window */
 339         u_long  rcv_wnd;                /* receive window */
 340         tcp_seq rcv_up;                 /* receive urgent pointer */
 341
 342         u_long  snd_wnd;                /* send window */
 343         u_long  snd_cwnd;               /* congestion-controlled window */
 344         u_long  snd_ssthresh;           /* snd_cwnd size threshold for
 345                                          * for slow start exponential to
 346                                          * linear switch
 347                                          */
 348         u_int   t_maxopd;               /* mss plus options */
 349
 350         u_long  t_rcvtime;              /* inactivity time */
 351         u_long  t_starttime;            /* time connection was established */
 352         int     t_rtttime;              /* round trip time */
 353         tcp_seq t_rtseq;                /* sequence number being timed */
 354
 355         int     t_rxtcur;               /* current retransmit value (ticks) */
 356         u_int   t_maxseg;               /* maximum segment size */
 357         int     t_srtt;                 /* smoothed round-trip time */
 358         int     t_rttvar;               /* variance in round-trip time */
 359
 360         int     t_rxtshift;             /* log(2) of rexmt exp. backoff */
 361         u_int   t_rttmin;               /* minimum rtt allowed */
 362         u_long  t_rttupdated;           /* number of times rtt sampled */
 363         u_long  max_sndwnd;             /* largest window peer has offered */
 364
 365         int     t_softerror;            /* possible error not yet reported */
 366 /* out-of-band data */
 367         char    t_oobflags;             /* have some */
 368         char    t_iobc;                 /* input character */
 369 #define TCPOOB_HAVEDATA 0x01
 370 #define TCPOOB_HADDATA  0x02
 371 /* RFC 1323 variables */
 372         u_char  snd_scale;              /* window scaling for send window */
 373         u_char  rcv_scale;              /* window scaling for recv window */
 374         u_char  request_r_scale;        /* pending window scaling */
 375         u_char  requested_s_scale;
 376         u_long  ts_recent;              /* timestamp echo data */
 377
 378         u_long  ts_recent_age;          /* when last updated */
 379         tcp_seq last_ack_sent;
 380 /* RFC 1644 variables */
 381         tcp_cc  cc_send;                /* send connection count */
 382         tcp_cc  cc_recv;                /* receive connection count */
 383         tcp_seq snd_recover;    /* for use in fast recovery */
 384 /* experimental */
 385         u_long  snd_cwnd_prev;          /* cwnd prior to retransmit */
 386         u_long  snd_ssthresh_prev;      /* ssthresh prior to retransmit */
 387         u_long  t_badrxtwin;            /* window for retransmit recovery */
 388 };
 389
 390 /*
 391  * TCP statistics.
 392  * Many of these should be kept per connection,
 393  * but that's inconvenient at the moment.
 394  */
 395 struct  tcpstat {
 396         u_long  tcps_connattempt;       /* connections initiated */
 397         u_long  tcps_accepts;           /* connections accepted */
 398         u_long  tcps_connects;          /* connections established */
 399         u_long  tcps_drops;             /* connections dropped */
 400         u_long  tcps_conndrops;         /* embryonic connections dropped */
 401         u_long  tcps_closed;            /* conn. closed (includes drops) */
 402         u_long  tcps_segstimed;         /* segs where we tried to get rtt */
 403         u_long  tcps_rttupdated;        /* times we succeeded */
 404         u_long  tcps_delack;            /* delayed acks sent */
 405         u_long  tcps_timeoutdrop;       /* conn. dropped in rxmt timeout */
 406         u_long  tcps_rexmttimeo;        /* retransmit timeouts */
 407         u_long  tcps_persisttimeo;      /* persist timeouts */
 408         u_long  tcps_keeptimeo;         /* keepalive timeouts */
 409         u_long  tcps_keepprobe;         /* keepalive probes sent */
 410         u_long  tcps_keepdrops;         /* connections dropped in keepalive */
 411
 412         u_long  tcps_sndtotal;          /* total packets sent */
 413         u_long  tcps_sndpack;           /* data packets sent */
 414         u_long  tcps_sndbyte;           /* data bytes sent */
 415         u_long  tcps_sndrexmitpack;     /* data packets retransmitted */
 416         u_long  tcps_sndrexmitbyte;     /* data bytes retransmitted */
 417         u_long  tcps_sndacks;           /* ack-only packets sent */
 418         u_long  tcps_sndprobe;          /* window probes sent */
 419         u_long  tcps_sndurg;            /* packets sent with URG only */
 420         u_long  tcps_sndwinup;          /* window update-only packets sent */
 421         u_long  tcps_sndctrl;           /* control (SYN|FIN|RST) packets sent */
 422
 423         u_long  tcps_rcvtotal;          /* total packets received */
 424         u_long  tcps_rcvpack;           /* packets received in sequence */
 425         u_long  tcps_rcvbyte;           /* bytes received in sequence */
 426         u_long  tcps_rcvbadsum;         /* packets received with ccksum errs */
 427         u_long  tcps_rcvbadoff;         /* packets received with bad offset */
 428         u_long  tcps_rcvmemdrop;        /* packets dropped for lack of memory */
 429         u_long  tcps_rcvshort;          /* packets received too short */
 430         u_long  tcps_rcvduppack;        /* duplicate-only packets received */
 431         u_long  tcps_rcvdupbyte;        /* duplicate-only bytes received */
 432         u_long  tcps_rcvpartduppack;    /* packets with some duplicate data */
 433         u_long  tcps_rcvpartdupbyte;    /* dup. bytes in part-dup. packets */
 434         u_long  tcps_rcvoopack;         /* out-of-order packets received */
 435         u_long  tcps_rcvoobyte;         /* out-of-order bytes received */
 436         u_long  tcps_rcvpackafterwin;   /* packets with data after window */
 437         u_long  tcps_rcvbyteafterwin;   /* bytes rcvd after window */
 438         u_long  tcps_rcvafterclose;     /* packets rcvd after "close" */
 439         u_long  tcps_rcvwinprobe;       /* rcvd window probe packets */
 440         u_long  tcps_rcvdupack;         /* rcvd duplicate acks */
 441         u_long  tcps_rcvacktoomuch;     /* rcvd acks for unsent data */
 442         u_long  tcps_rcvackpack;        /* rcvd ack packets */
 443         u_long  tcps_rcvackbyte;        /* bytes acked by rcvd acks */
 444         u_long  tcps_rcvwinupd;         /* rcvd window update packets */
 445         u_long  tcps_pawsdrop;          /* segments dropped due to PAWS */
 446         u_long  tcps_predack;           /* times hdr predict ok for acks */
 447         u_long  tcps_preddat;           /* times hdr predict ok for data pkts */
 448         u_long  tcps_pcbcachemiss;
 449         u_long  tcps_cachedrtt;         /* times cached RTT in route updated */
 450         u_long  tcps_cachedrttvar;      /* times cached rttvar updated */
 451         u_long  tcps_cachedssthresh;    /* times cached ssthresh updated */
 452         u_long  tcps_usedrtt;           /* times RTT initialized from route */
 453         u_long  tcps_usedrttvar;        /* times RTTVAR initialized from rt */
 454         u_long  tcps_usedssthresh;      /* times ssthresh initialized from rt*/
 455         u_long  tcps_persistdrop;       /* timeout in persist state */
 456         u_long  tcps_badsyn;            /* bogus SYN, e.g. premature ACK */
 457         u_long  tcps_mturesent;         /* resends due to MTU discovery */
 458         u_long  tcps_listendrop;        /* listen queue overflows */
 459 };
 460
 461 /*
 462  * TCB structure exported to user-land via sysctl(3).
 463  * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
 464  * included.  Not all of our clients do.
 465  */
 466 struct  xtcpcb {
 467         size_t  xt_len;
 468 #ifdef KERNEL_PRIVATE
 469         struct  inpcb_compat    xt_inp;
 470 #else
 471         struct  inpcb   xt_inp;
 472 #endif
 473 #ifdef KERNEL_PRIVATE
 474         struct  otcpcb  xt_tp;
 475 #else
 476         struct  tcpcb   xt_tp;
 477 #endif
 478         struct  xsocket xt_socket;
 479         u_quad_t        xt_alignment_hack;
 480 };
 481
 482 /*
 483  * Names for TCP sysctl objects
 484  */
 485 #define TCPCTL_DO_RFC1323       1       /* use RFC-1323 extensions */
 486 #define TCPCTL_DO_RFC1644       2       /* use RFC-1644 extensions */
 487 #define TCPCTL_MSSDFLT          3       /* MSS default */
 488 #define TCPCTL_STATS            4       /* statistics (read-only) */
 489 #define TCPCTL_RTTDFLT          5       /* default RTT estimate */
 490 #define TCPCTL_KEEPIDLE         6       /* keepalive idle timer */
 491 #define TCPCTL_KEEPINTVL        7       /* interval to send keepalives */
 492 #define TCPCTL_SENDSPACE        8       /* send buffer space */
 493 #define TCPCTL_RECVSPACE        9       /* receive buffer space */
 494 #define TCPCTL_KEEPINIT         10      /* timeout for establishing syn */
 495 #define TCPCTL_PCBLIST          11      /* list of all outstanding PCBs */
 496 #define TCPCTL_DELACKTIME       12      /* time before sending delayed ACK */
 497 #define TCPCTL_V6MSSDFLT        13      /* MSS default for IPv6 */
 498 #define TCPCTL_MAXID            14
 499
 500 #ifdef KERNEL_PRIVATE
 501 #define TCPCTL_NAMES { \
 502         { 0, 0 }, \
 503         { "rfc1323", CTLTYPE_INT }, \
 504         { "rfc1644", CTLTYPE_INT }, \
 505         { "mssdflt", CTLTYPE_INT }, \
 506         { "stats", CTLTYPE_STRUCT }, \
 507         { "rttdflt", CTLTYPE_INT }, \
 508         { "keepidle", CTLTYPE_INT }, \
 509         { "keepintvl", CTLTYPE_INT }, \
 510         { "sendspace", CTLTYPE_INT }, \
 511         { "recvspace", CTLTYPE_INT }, \
 512         { "keepinit", CTLTYPE_INT }, \
 513         { "pcblist", CTLTYPE_STRUCT }, \
 514         { "delacktime", CTLTYPE_INT }, \
 515         { "v6mssdflt", CTLTYPE_INT }, \
 516 }
 517
 518 #ifdef SYSCTL_DECL
 519 SYSCTL_DECL(_net_inet_tcp);
 520 #endif /* SYSCTL_DECL */
 521
 522 extern  struct inpcbhead tcb;           /* head of queue of active tcpcb's */
 523 extern  struct inpcbinfo tcbinfo;
 524 extern  struct tcpstat tcpstat; /* tcp statistics */
 525 extern  int tcp_mssdflt;        /* XXX */
 526 extern  int tcp_minmss;
 527 extern  int tcp_minmssoverload;
 528 extern  int tcp_do_newreno;
 529 extern  int ss_fltsz;
 530 extern  int ss_fltsz_local;
 531 #ifdef __APPLE__
 532 extern  u_long tcp_now;         /* for RFC 1323 timestamps */
 533 extern  int tcp_delack_enabled;
 534 #endif /* __APPLE__ */
 535
 536
 537 void     tcp_canceltimers(struct tcpcb *);
 538 struct tcpcb *
 539          tcp_close(struct tcpcb *);
 540 void     tcp_ctlinput(int, struct sockaddr *, void *);
 541 int      tcp_ctloutput(struct socket *, struct sockopt *);
 542 struct tcpcb *
 543          tcp_drop(struct tcpcb *, int);
 544 void     tcp_drain(void);
 545 void     tcp_fasttimo(void);
 546 struct rmxp_tao *
 547          tcp_gettaocache(struct inpcb *);
 548 void     tcp_init(void);
 549 void     tcp_input(struct mbuf *, int);
 550 void     tcp_mss(struct tcpcb *, int);
 551 int      tcp_mssopt(struct tcpcb *);
 552 void     tcp_drop_syn_sent(struct inpcb *, int);
 553 void     tcp_mtudisc(struct inpcb *, int);
 554 struct tcpcb *
 555          tcp_newtcpcb(struct inpcb *);
 556 int      tcp_output(struct tcpcb *);
 557 void     tcp_quench(struct inpcb *, int);
 558 void     tcp_respond(struct tcpcb *, void *,
 559             struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
 560 struct rtentry *
 561          tcp_rtlookup(struct inpcb *);
 562 void     tcp_setpersist(struct tcpcb *);
 563 void     tcp_slowtimo(void);
 564 struct tcptemp *
 565          tcp_maketemplate(struct tcpcb *);
 566 void     tcp_fillheaders(struct tcpcb *, void *, void *);
 567 struct tcpcb *
 568          tcp_timers(struct tcpcb *, int);
 569 void     tcp_trace(int, int, struct tcpcb *, void *, struct tcphdr *, int);
 570 int      tcp_lock (struct socket *, int, int);
 571 int      tcp_unlock (struct socket *, int, int);
 572 #ifdef _KERN_LOCKS_H_
 573 lck_mtx_t *      tcp_getlock (struct socket *, int);
 574 #else
 575 void *   tcp_getlock (struct socket *, int);
 576 #endif
 577
 578
 579 extern  struct pr_usrreqs tcp_usrreqs;
 580 extern  u_long tcp_sendspace;
 581 extern  u_long tcp_recvspace;
 582 tcp_seq tcp_new_isn(struct tcpcb *);
 583
 584 #endif /* KERNEL_RPIVATE */
 585
 586 #endif /* _NETINET_TCP_VAR_H_ */