bsd/netinet/tcp_var.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1982, 1986, 1993, 1994, 1995
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  *
  54  *      @(#)tcp_var.h   8.4 (Berkeley) 5/24/95
  55  * $FreeBSD: src/sys/netinet/tcp_var.h,v 1.56.2.8 2001/08/22 00:59:13 silby Exp $
  56  */
  57
  58 #ifndef _NETINET_TCP_VAR_H_
  59 #define _NETINET_TCP_VAR_H_
  60 #include <sys/appleapiopts.h>
  61 #include <netinet/tcp_timer.h>
  62 #ifdef __APPLE_API_PRIVATE
  63
  64 #define N_TIME_WAIT_SLOTS   128                /* must be power of 2 */
  65
  66 /*
  67  * Kernel variables for tcp.
  68  */
  69
  70 /* TCP segment queue entry */
  71 struct tseg_qent {
  72         LIST_ENTRY(tseg_qent) tqe_q;
  73         int     tqe_len;                /* TCP segment data length */
  74         struct  tcphdr *tqe_th;         /* a pointer to tcp header */
  75         struct  mbuf    *tqe_m;         /* mbuf contains packet */
  76 };
  77 LIST_HEAD(tsegqe_head, tseg_qent);
  78 #ifdef MALLOC_DECLARE
  79 MALLOC_DECLARE(M_TSEGQ);
  80 #endif
  81
  82 struct tcptemp {
  83         u_char  tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
  84         struct  tcphdr tt_t;
  85 };
  86
  87 #define tcp6cb          tcpcb  /* for KAME src sync over BSD*'s */
  88
  89 #ifdef __APPLE__
  90 #define TCP_DELACK_BITSET(hash_elem)\
  91 delack_bitmask[((hash_elem) >> 5)] |= 1 << ((hash_elem) & 0x1F)
  92
  93 #define DELACK_BITMASK_ON     1
  94 #define DELACK_BITMASK_THRESH 300
  95 #endif
  96
  97 /*
  98  * Tcp control block, one per tcp; fields:
  99  * Organized for 16 byte cacheline efficiency.
 100  */
 101 struct tcpcb {
 102         struct  tsegqe_head t_segq;
 103         int     t_dupacks;              /* consecutive dup acks recd */
 104         struct  tcptemp *unused;        /* unused now: was t_template */
 105
 106         int     t_timer[TCPT_NTIMERS];  /* tcp timers */
 107
 108         struct  inpcb *t_inpcb;         /* back pointer to internet pcb */
 109         int     t_state;                /* state of this connection */
 110         u_int   t_flags;
 111 #define TF_ACKNOW       0x00001         /* ack peer immediately */
 112 #define TF_DELACK       0x00002         /* ack, but try to delay it */
 113 #define TF_NODELAY      0x00004         /* don't delay packets to coalesce */
 114 #define TF_NOOPT        0x00008         /* don't use tcp options */
 115 #define TF_SENTFIN      0x00010         /* have sent FIN */
 116 #define TF_REQ_SCALE    0x00020         /* have/will request window scaling */
 117 #define TF_RCVD_SCALE   0x00040         /* other side has requested scaling */
 118 #define TF_REQ_TSTMP    0x00080         /* have/will request timestamps */
 119 #define TF_RCVD_TSTMP   0x00100         /* a timestamp was received in SYN */
 120 #define TF_SACK_PERMIT  0x00200         /* other side said I could SACK */
 121 #define TF_NEEDSYN      0x00400         /* send SYN (implicit state) */
 122 #define TF_NEEDFIN      0x00800         /* send FIN (implicit state) */
 123 #define TF_NOPUSH       0x01000         /* don't push */
 124 #define TF_REQ_CC       0x02000         /* have/will request CC */
 125 #define TF_RCVD_CC      0x04000         /* a CC was received in SYN */
 126 #define TF_SENDCCNEW    0x08000         /* send CCnew instead of CC in SYN */
 127 #define TF_MORETOCOME   0x10000         /* More data to be appended to sock */
 128 #define TF_LQ_OVERFLOW  0x20000         /* listen queue overflow */
 129 #define TF_RXWIN0SENT   0x40000         /* sent a receiver win 0 in response */
 130 #define TF_SLOWLINK     0x80000         /* route is a on a modem speed link */
 131
 132         int     t_force;                /* 1 if forcing out a byte */
 133
 134         tcp_seq snd_una;                /* send unacknowledged */
 135         tcp_seq snd_max;                /* highest sequence number sent;
 136                                          * used to recognize retransmits
 137                                          */
 138         tcp_seq snd_nxt;                /* send next */
 139         tcp_seq snd_up;                 /* send urgent pointer */
 140
 141         tcp_seq snd_wl1;                /* window update seg seq number */
 142         tcp_seq snd_wl2;                /* window update seg ack number */
 143         tcp_seq iss;                    /* initial send sequence number */
 144         tcp_seq irs;                    /* initial receive sequence number */
 145
 146         tcp_seq rcv_nxt;                /* receive next */
 147         tcp_seq rcv_adv;                /* advertised window */
 148         u_long  rcv_wnd;                /* receive window */
 149         tcp_seq rcv_up;                 /* receive urgent pointer */
 150
 151         u_long  snd_wnd;                /* send window */
 152         u_long  snd_cwnd;               /* congestion-controlled window */
 153         u_long  snd_ssthresh;           /* snd_cwnd size threshold for
 154                                          * for slow start exponential to
 155                                          * linear switch
 156                                          */
 157         u_int   t_maxopd;               /* mss plus options */
 158
 159         u_long  t_rcvtime;              /* inactivity time */
 160         u_long  t_starttime;            /* time connection was established */
 161         int     t_rtttime;              /* round trip time */
 162         tcp_seq t_rtseq;                /* sequence number being timed */
 163
 164         int     t_rxtcur;               /* current retransmit value (ticks) */
 165         u_int   t_maxseg;               /* maximum segment size */
 166         int     t_srtt;                 /* smoothed round-trip time */
 167         int     t_rttvar;               /* variance in round-trip time */
 168
 169         int     t_rxtshift;             /* log(2) of rexmt exp. backoff */
 170         u_int   t_rttmin;               /* minimum rtt allowed */
 171         u_long  t_rttupdated;           /* number of times rtt sampled */
 172         u_long  max_sndwnd;             /* largest window peer has offered */
 173
 174         int     t_softerror;            /* possible error not yet reported */
 175 /* out-of-band data */
 176         char    t_oobflags;             /* have some */
 177         char    t_iobc;                 /* input character */
 178 #define TCPOOB_HAVEDATA 0x01
 179 #define TCPOOB_HADDATA  0x02
 180 /* RFC 1323 variables */
 181         u_char  snd_scale;              /* window scaling for send window */
 182         u_char  rcv_scale;              /* window scaling for recv window */
 183         u_char  request_r_scale;        /* pending window scaling */
 184         u_char  requested_s_scale;
 185         u_long  ts_recent;              /* timestamp echo data */
 186
 187         u_long  ts_recent_age;          /* when last updated */
 188         tcp_seq last_ack_sent;
 189 /* RFC 1644 variables */
 190         tcp_cc  cc_send;                /* send connection count */
 191         tcp_cc  cc_recv;                /* receive connection count */
 192         tcp_seq snd_recover;            /* for use in fast recovery */
 193 /* experimental */
 194         u_long  snd_cwnd_prev;          /* cwnd prior to retransmit */
 195         u_long  snd_ssthresh_prev;      /* ssthresh prior to retransmit */
 196         u_long  t_badrxtwin;            /* window for retransmit recovery */
 197 };
 198
 199 /*
 200  * Structure to hold TCP options that are only used during segment
 201  * processing (in tcp_input), but not held in the tcpcb.
 202  * It's basically used to reduce the number of parameters
 203  * to tcp_dooptions.
 204  */
 205 struct tcpopt {
 206         u_long  to_flag;                /* which options are present */
 207 #define TOF_TS          0x0001          /* timestamp */
 208 #define TOF_CC          0x0002          /* CC and CCnew are exclusive */
 209 #define TOF_CCNEW       0x0004
 210 #define TOF_CCECHO      0x0008
 211         u_long  to_tsval;
 212         u_long  to_tsecr;
 213         tcp_cc  to_cc;          /* holds CC or CCnew */
 214         tcp_cc  to_ccecho;
 215         u_short         reserved;               /* unused now: was to_maxseg */
 216 };
 217
 218 /*
 219  * The TAO cache entry which is stored in the protocol family specific
 220  * portion of the route metrics.
 221  */
 222 struct rmxp_tao {
 223         tcp_cc  tao_cc;                 /* latest CC in valid SYN */
 224         tcp_cc  tao_ccsent;             /* latest CC sent to peer */
 225         u_short tao_mssopt;             /* peer's cached MSS */
 226 #ifdef notyet
 227         u_short tao_flags;              /* cache status flags */
 228 #define TAOF_DONT       0x0001          /* peer doesn't understand rfc1644 */
 229 #define TAOF_OK         0x0002          /* peer does understand rfc1644 */
 230 #define TAOF_UNDEF      0               /* we don't know yet */
 231 #endif /* notyet */
 232 };
 233 #define rmx_taop(r)     ((struct rmxp_tao *)(r).rmx_filler)
 234
 235 #define intotcpcb(ip)   ((struct tcpcb *)(ip)->inp_ppcb)
 236 #define sototcpcb(so)   (intotcpcb(sotoinpcb(so)))
 237
 238 /*
 239  * The smoothed round-trip time and estimated variance
 240  * are stored as fixed point numbers scaled by the values below.
 241  * For convenience, these scales are also used in smoothing the average
 242  * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
 243  * With these scales, srtt has 3 bits to the right of the binary point,
 244  * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
 245  * binary point, and is smoothed with an ALPHA of 0.75.
 246  */
 247 #define TCP_RTT_SCALE           32      /* multiplier for srtt; 3 bits frac. */
 248 #define TCP_RTT_SHIFT           5       /* shift for srtt; 3 bits frac. */
 249 #define TCP_RTTVAR_SCALE        16      /* multiplier for rttvar; 2 bits */
 250 #define TCP_RTTVAR_SHIFT        4       /* shift for rttvar; 2 bits */
 251 #define TCP_DELTA_SHIFT         2       /* see tcp_input.c */
 252
 253 /*
 254  * The initial retransmission should happen at rtt + 4 * rttvar.
 255  * Because of the way we do the smoothing, srtt and rttvar
 256  * will each average +1/2 tick of bias.  When we compute
 257  * the retransmit timer, we want 1/2 tick of rounding and
 258  * 1 extra tick because of +-1/2 tick uncertainty in the
 259  * firing of the timer.  The bias will give us exactly the
 260  * 1.5 tick we need.  But, because the bias is
 261  * statistical, we have to test that we don't drop below
 262  * the minimum feasible timer (which is 2 ticks).
 263  * This version of the macro adapted from a paper by Lawrence
 264  * Brakmo and Larry Peterson which outlines a problem caused
 265  * by insufficient precision in the original implementation,
 266  * which results in inappropriately large RTO values for very
 267  * fast networks.
 268  */
 269 #define TCP_REXMTVAL(tp) \
 270         max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
 271           + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
 272 #endif /* __APPLE_API_PRIVATE */
 273
 274 #ifdef __APPLE_API_UNSTABLE
 275 /*
 276  * TCP statistics.
 277  * Many of these should be kept per connection,
 278  * but that's inconvenient at the moment.
 279  */
 280 struct  tcpstat {
 281         u_long  tcps_connattempt;       /* connections initiated */
 282         u_long  tcps_accepts;           /* connections accepted */
 283         u_long  tcps_connects;          /* connections established */
 284         u_long  tcps_drops;             /* connections dropped */
 285         u_long  tcps_conndrops;         /* embryonic connections dropped */
 286         u_long  tcps_closed;            /* conn. closed (includes drops) */
 287         u_long  tcps_segstimed;         /* segs where we tried to get rtt */
 288         u_long  tcps_rttupdated;        /* times we succeeded */
 289         u_long  tcps_delack;            /* delayed acks sent */
 290         u_long  tcps_timeoutdrop;       /* conn. dropped in rxmt timeout */
 291         u_long  tcps_rexmttimeo;        /* retransmit timeouts */
 292         u_long  tcps_persisttimeo;      /* persist timeouts */
 293         u_long  tcps_keeptimeo;         /* keepalive timeouts */
 294         u_long  tcps_keepprobe;         /* keepalive probes sent */
 295         u_long  tcps_keepdrops;         /* connections dropped in keepalive */
 296
 297         u_long  tcps_sndtotal;          /* total packets sent */
 298         u_long  tcps_sndpack;           /* data packets sent */
 299         u_long  tcps_sndbyte;           /* data bytes sent */
 300         u_long  tcps_sndrexmitpack;     /* data packets retransmitted */
 301         u_long  tcps_sndrexmitbyte;     /* data bytes retransmitted */
 302         u_long  tcps_sndacks;           /* ack-only packets sent */
 303         u_long  tcps_sndprobe;          /* window probes sent */
 304         u_long  tcps_sndurg;            /* packets sent with URG only */
 305         u_long  tcps_sndwinup;          /* window update-only packets sent */
 306         u_long  tcps_sndctrl;           /* control (SYN|FIN|RST) packets sent */
 307
 308         u_long  tcps_rcvtotal;          /* total packets received */
 309         u_long  tcps_rcvpack;           /* packets received in sequence */
 310         u_long  tcps_rcvbyte;           /* bytes received in sequence */
 311         u_long  tcps_rcvbadsum;         /* packets received with ccksum errs */
 312         u_long  tcps_rcvbadoff;         /* packets received with bad offset */
 313         u_long  tcps_rcvmemdrop;        /* packets dropped for lack of memory */
 314         u_long  tcps_rcvshort;          /* packets received too short */
 315         u_long  tcps_rcvduppack;        /* duplicate-only packets received */
 316         u_long  tcps_rcvdupbyte;        /* duplicate-only bytes received */
 317         u_long  tcps_rcvpartduppack;    /* packets with some duplicate data */
 318         u_long  tcps_rcvpartdupbyte;    /* dup. bytes in part-dup. packets */
 319         u_long  tcps_rcvoopack;         /* out-of-order packets received */
 320         u_long  tcps_rcvoobyte;         /* out-of-order bytes received */
 321         u_long  tcps_rcvpackafterwin;   /* packets with data after window */
 322         u_long  tcps_rcvbyteafterwin;   /* bytes rcvd after window */
 323         u_long  tcps_rcvafterclose;     /* packets rcvd after "close" */
 324         u_long  tcps_rcvwinprobe;       /* rcvd window probe packets */
 325         u_long  tcps_rcvdupack;         /* rcvd duplicate acks */
 326         u_long  tcps_rcvacktoomuch;     /* rcvd acks for unsent data */
 327         u_long  tcps_rcvackpack;        /* rcvd ack packets */
 328         u_long  tcps_rcvackbyte;        /* bytes acked by rcvd acks */
 329         u_long  tcps_rcvwinupd;         /* rcvd window update packets */
 330         u_long  tcps_pawsdrop;          /* segments dropped due to PAWS */
 331         u_long  tcps_predack;           /* times hdr predict ok for acks */
 332         u_long  tcps_preddat;           /* times hdr predict ok for data pkts */
 333         u_long  tcps_pcbcachemiss;
 334         u_long  tcps_cachedrtt;         /* times cached RTT in route updated */
 335         u_long  tcps_cachedrttvar;      /* times cached rttvar updated */
 336         u_long  tcps_cachedssthresh;    /* times cached ssthresh updated */
 337         u_long  tcps_usedrtt;           /* times RTT initialized from route */
 338         u_long  tcps_usedrttvar;        /* times RTTVAR initialized from rt */
 339         u_long  tcps_usedssthresh;      /* times ssthresh initialized from rt*/
 340         u_long  tcps_persistdrop;       /* timeout in persist state */
 341         u_long  tcps_badsyn;            /* bogus SYN, e.g. premature ACK */
 342         u_long  tcps_mturesent;         /* resends due to MTU discovery */
 343         u_long  tcps_listendrop;        /* listen queue overflows */
 344 };
 345 #endif /* __APPLE_API_UNSTABLE */
 346
 347 /*
 348  * TCB structure exported to user-land via sysctl(3).
 349  * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
 350  * included.  Not all of our clients do.
 351  */
 352 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
 353 struct  xtcpcb {
 354         size_t  xt_len;
 355         struct  inpcb   xt_inp;
 356         struct  tcpcb   xt_tp;
 357         struct  xsocket xt_socket;
 358         u_quad_t        xt_alignment_hack;
 359 };
 360 #endif
 361
 362 /*
 363  * Names for TCP sysctl objects
 364  */
 365 #define TCPCTL_DO_RFC1323       1       /* use RFC-1323 extensions */
 366 #define TCPCTL_DO_RFC1644       2       /* use RFC-1644 extensions */
 367 #define TCPCTL_MSSDFLT          3       /* MSS default */
 368 #define TCPCTL_STATS            4       /* statistics (read-only) */
 369 #define TCPCTL_RTTDFLT          5       /* default RTT estimate */
 370 #define TCPCTL_KEEPIDLE         6       /* keepalive idle timer */
 371 #define TCPCTL_KEEPINTVL        7       /* interval to send keepalives */
 372 #define TCPCTL_SENDSPACE        8       /* send buffer space */
 373 #define TCPCTL_RECVSPACE        9       /* receive buffer space */
 374 #define TCPCTL_KEEPINIT         10      /* timeout for establishing syn */
 375 #define TCPCTL_PCBLIST          11      /* list of all outstanding PCBs */
 376 #define TCPCTL_DELACKTIME       12      /* time before sending delayed ACK */
 377 #define TCPCTL_V6MSSDFLT        13      /* MSS default for IPv6 */
 378 #define TCPCTL_MAXID            14
 379
 380 #define TCPCTL_NAMES { \
 381         { 0, 0 }, \
 382         { "rfc1323", CTLTYPE_INT }, \
 383         { "rfc1644", CTLTYPE_INT }, \
 384         { "mssdflt", CTLTYPE_INT }, \
 385         { "stats", CTLTYPE_STRUCT }, \
 386         { "rttdflt", CTLTYPE_INT }, \
 387         { "keepidle", CTLTYPE_INT }, \
 388         { "keepintvl", CTLTYPE_INT }, \
 389         { "sendspace", CTLTYPE_INT }, \
 390         { "recvspace", CTLTYPE_INT }, \
 391         { "keepinit", CTLTYPE_INT }, \
 392         { "pcblist", CTLTYPE_STRUCT }, \
 393         { "delacktime", CTLTYPE_INT }, \
 394         { "v6mssdflt", CTLTYPE_INT }, \
 395 }
 396
 397 #ifdef __APPLE_API_PRIVATE
 398 #ifdef KERNEL
 399 #ifdef SYSCTL_DECL
 400 SYSCTL_DECL(_net_inet_tcp);
 401 #endif
 402
 403 extern  struct inpcbhead tcb;           /* head of queue of active tcpcb's */
 404 extern  struct inpcbinfo tcbinfo;
 405 extern  struct tcpstat tcpstat; /* tcp statistics */
 406 extern  int tcp_mssdflt;        /* XXX */
 407 extern  int tcp_delack_enabled;
 408 extern  int tcp_do_newreno;
 409 extern  int ss_fltsz;
 410 extern  int ss_fltsz_local;
 411 #ifdef __APPLE__
 412 extern  u_long tcp_now;         /* for RFC 1323 timestamps */
 413 extern  int tcp_delack_enabled;
 414 #endif
 415
 416
 417 void     tcp_canceltimers __P((struct tcpcb *));
 418 struct tcpcb *
 419          tcp_close __P((struct tcpcb *));
 420 void     tcp_ctlinput __P((int, struct sockaddr *, void *));
 421 int      tcp_ctloutput __P((struct socket *, struct sockopt *));
 422 struct tcpcb *
 423          tcp_drop __P((struct tcpcb *, int));
 424 void     tcp_drain __P((void));
 425 void     tcp_fasttimo __P((void));
 426 struct rmxp_tao *
 427          tcp_gettaocache __P((struct inpcb *));
 428 void     tcp_init __P((void));
 429 void     tcp_input __P((struct mbuf *, int));
 430 void     tcp_mss __P((struct tcpcb *, int));
 431 int      tcp_mssopt __P((struct tcpcb *));
 432 void     tcp_drop_syn_sent __P((struct inpcb *, int));
 433 void     tcp_mtudisc __P((struct inpcb *, int));
 434 struct tcpcb *
 435          tcp_newtcpcb __P((struct inpcb *));
 436 int      tcp_output __P((struct tcpcb *));
 437 void     tcp_quench __P((struct inpcb *, int));
 438 void     tcp_respond __P((struct tcpcb *, void *,
 439             struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int));
 440 struct rtentry *
 441          tcp_rtlookup __P((struct inpcb *));
 442 void     tcp_setpersist __P((struct tcpcb *));
 443 void     tcp_slowtimo __P((void));
 444 struct tcptemp *
 445          tcp_maketemplate __P((struct tcpcb *));
 446 void     tcp_fillheaders __P((struct tcpcb *, void *, void *));
 447 struct tcpcb *
 448          tcp_timers __P((struct tcpcb *, int));
 449 void     tcp_trace __P((int, int, struct tcpcb *, void *, struct tcphdr *,
 450                         int));
 451
 452 extern  struct pr_usrreqs tcp_usrreqs;
 453 extern  u_long tcp_sendspace;
 454 extern  u_long tcp_recvspace;
 455 tcp_seq tcp_new_isn __P((struct tcpcb *));
 456
 457 #endif /* KERNEL */
 458 #endif /* __APPLE_API_PRIVATE */
 459
 460 #endif /* _NETINET_TCP_VAR_H_ */