sys/netinet/tcp_var.h

   1 /*
   2  * Copyright (c) 2003-2004 Jeffrey Hsu.  All rights reserved.
   3  * Copyright (c) 1982, 1986, 1993, 1994, 1995
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the University of
  17  *      California, Berkeley and its contributors.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)tcp_var.h   8.4 (Berkeley) 5/24/95
  35  * $FreeBSD: src/sys/netinet/tcp_var.h,v 1.56.2.13 2003/02/03 02:34:07 hsu Exp $
  36  * $DragonFly: src/sys/netinet/tcp_var.h,v 1.15 2004/03/14 08:21:53 hsu Exp $
  37  */
  38
  39 #ifndef _NETINET_TCP_VAR_H_
  40 #define _NETINET_TCP_VAR_H_
  41
  42 #include <netinet/in_pcb.h>             /* needed for in_conninfo, inp_gen_t */
  43
  44 /*
  45  * Kernel variables for tcp.
  46  */
  47 extern int      tcp_do_rfc1323;
  48 extern int      tcp_do_rfc1644;
  49
  50 /* TCP segment queue entry */
  51 struct tseg_qent {
  52         LIST_ENTRY(tseg_qent) tqe_q;
  53         int     tqe_len;                /* TCP segment data length */
  54         struct  tcphdr *tqe_th;         /* a pointer to tcp header */
  55         struct  mbuf    *tqe_m;         /* mbuf contains packet */
  56 };
  57 LIST_HEAD(tsegqe_head, tseg_qent);
  58 extern int      tcp_reass_maxseg;
  59 extern int      tcp_reass_qsize;
  60 #ifdef MALLOC_DECLARE
  61 MALLOC_DECLARE(M_TSEGQ);
  62 #endif
  63
  64 struct tcptemp {
  65         u_char  tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
  66         struct  tcphdr tt_t;
  67 };
  68
  69 #define tcp6cb          tcpcb  /* for KAME src sync over BSD*'s */
  70
  71 /*
  72  * Tcp control block, one per tcp; fields:
  73  * Organized for 16 byte cacheline efficiency.
  74  */
  75 struct tcpcb {
  76         struct  tsegqe_head t_segq;
  77         int     t_dupacks;              /* consecutive dup acks recd */
  78         struct  tcptemp *unused;        /* unused */
  79
  80         struct  callout *tt_rexmt;      /* retransmit timer */
  81         struct  callout *tt_persist;    /* retransmit persistence */
  82         struct  callout *tt_keep;       /* keepalive */
  83         struct  callout *tt_2msl;       /* 2*msl TIME_WAIT timer */
  84         struct  callout *tt_delack;     /* delayed ACK timer */
  85
  86         struct  inpcb *t_inpcb;         /* back pointer to internet pcb */
  87         int     t_state;                /* state of this connection */
  88         u_int   t_flags;
  89 #define TF_ACKNOW       0x00000001      /* ack peer immediately */
  90 #define TF_DELACK       0x00000002      /* ack, but try to delay it */
  91 #define TF_NODELAY      0x00000004      /* don't delay packets to coalesce */
  92 #define TF_NOOPT        0x00000008      /* don't use tcp options */
  93 #define TF_SENTFIN      0x00000010      /* have sent FIN */
  94 #define TF_REQ_SCALE    0x00000020      /* have/will request window scaling */
  95 #define TF_RCVD_SCALE   0x00000040      /* other side has requested scaling */
  96 #define TF_REQ_TSTMP    0x00000080      /* have/will request timestamps */
  97 #define TF_RCVD_TSTMP   0x00000100      /* a timestamp was received in SYN */
  98 #define TF_SACK_PERMIT  0x00000200      /* other side said I could SACK */
  99 #define TF_NEEDSYN      0x00000400      /* send SYN (implicit state) */
 100 #define TF_NEEDFIN      0x00000800      /* send FIN (implicit state) */
 101 #define TF_NOPUSH       0x00001000      /* don't push */
 102 #define TF_REQ_CC       0x00002000      /* have/will request CC */
 103 #define TF_RCVD_CC      0x00004000      /* a CC was received in SYN */
 104 #define TF_SENDCCNEW    0x00008000      /* send CCnew instead of CC in SYN */
 105 #define TF_MORETOCOME   0x00010000      /* More data to be appended to sock */
 106 #define TF_LQ_OVERFLOW  0x00020000      /* listen queue overflow */
 107 #define TF_LASTIDLE     0x00040000      /* connection was previously idle */
 108 #define TF_RXWIN0SENT   0x00080000      /* sent a receiver win 0 in response */
 109 #define TF_FASTRECOVERY 0x00100000      /* in NewReno Fast Recovery */
 110 #define TF_WASFRECOVERY 0x00200000      /* was in NewReno Fast Recovery */
 111 #define TF_FIRSTACCACK  0x00400000      /* Look for 1st acceptable ACK. */
 112 #define TF_FASTREXMT    0x00800000      /* Did Fast Retransmit. */
 113 #define TF_EARLYREXMT   0x01000000      /* Did Early (Fast) Retransmit. */
 114         int     t_force;                /* 1 if forcing out a byte */
 115
 116         tcp_seq snd_una;                /* send unacknowledged */
 117         tcp_seq snd_max;                /* highest sequence number sent;
 118                                          * used to recognize retransmits
 119                                          */
 120         tcp_seq snd_nxt;                /* send next */
 121         tcp_seq snd_up;                 /* send urgent pointer */
 122
 123         tcp_seq snd_wl1;                /* window update seg seq number */
 124         tcp_seq snd_wl2;                /* window update seg ack number */
 125         tcp_seq iss;                    /* initial send sequence number */
 126         tcp_seq irs;                    /* initial receive sequence number */
 127
 128         tcp_seq rcv_nxt;                /* receive next */
 129         tcp_seq rcv_adv;                /* advertised window */
 130         u_long  rcv_wnd;                /* receive window */
 131         tcp_seq rcv_up;                 /* receive urgent pointer */
 132
 133         u_long  snd_wnd;                /* send window */
 134         u_long  snd_cwnd;               /* congestion-controlled window */
 135         u_long  snd_bwnd;               /* bandwidth-controlled window */
 136         u_long  snd_ssthresh;           /* snd_cwnd size threshold for
 137                                          * for slow start exponential to
 138                                          * linear switch
 139                                          */
 140         u_long  snd_bandwidth;          /* calculated bandwidth or 0 */
 141         tcp_seq snd_recover;            /* for use in NewReno fast recovery */
 142
 143         u_int   t_maxopd;               /* mss plus options */
 144
 145         u_long  t_rcvtime;              /* inactivity time */
 146         u_long  t_starttime;            /* time connection was established */
 147         int     t_rtttime;              /* round trip time */
 148         tcp_seq t_rtseq;                /* sequence number being timed */
 149
 150         int     t_bw_rtttime;           /* used for bandwidth calculation */
 151         tcp_seq t_bw_rtseq;             /* used for bandwidth calculation */
 152
 153         int     t_rxtcur;               /* current retransmit value (ticks) */
 154         u_int   t_maxseg;               /* maximum segment size */
 155         int     t_srtt;                 /* smoothed round-trip time */
 156         int     t_rttvar;               /* variance in round-trip time */
 157
 158         int     t_rxtshift;             /* log(2) of rexmt exp. backoff */
 159         u_int   t_rttmin;               /* minimum rtt allowed */
 160         u_int   t_rttbest;              /* best rtt we've seen */
 161         u_long  t_rttupdated;           /* number of times rtt sampled */
 162         u_long  max_sndwnd;             /* largest window peer has offered */
 163
 164         int     t_softerror;            /* possible error not yet reported */
 165 /* out-of-band data */
 166         char    t_oobflags;             /* have some */
 167         char    t_iobc;                 /* input character */
 168 #define TCPOOB_HAVEDATA 0x01
 169 #define TCPOOB_HADDATA  0x02
 170 /* RFC 1323 variables */
 171         u_char  snd_scale;              /* window scaling for send window */
 172         u_char  rcv_scale;              /* window scaling for recv window */
 173         u_char  request_r_scale;        /* pending window scaling */
 174         u_char  requested_s_scale;
 175         u_long  ts_recent;              /* timestamp echo data */
 176
 177         u_long  ts_recent_age;          /* when last updated */
 178         tcp_seq last_ack_sent;
 179 /* RFC 1644 variables */
 180         tcp_cc  cc_send;                /* send connection count */
 181         tcp_cc  cc_recv;                /* receive connection count */
 182 /* experimental */
 183         u_long  snd_cwnd_prev;          /* cwnd prior to retransmit */
 184         u_long  snd_ssthresh_prev;      /* ssthresh prior to retransmit */
 185         tcp_seq snd_recover_prev;       /* snd_recover prior to retransmit */
 186         u_long  t_badrxtwin;            /* window for retransmit recovery */
 187         u_long  t_rexmtTS;              /* timestamp of last retransmit */
 188         u_char  snd_limited;            /* segments limited transmitted */
 189 };
 190
 191 #define IN_FASTRECOVERY(tp)     (tp->t_flags & TF_FASTRECOVERY)
 192 #define ENTER_FASTRECOVERY(tp)  tp->t_flags |= TF_FASTRECOVERY
 193 #define EXIT_FASTRECOVERY(tp)   tp->t_flags &= ~TF_FASTRECOVERY
 194
 195 /*
 196  * Structure to hold TCP options that are only used during segment
 197  * processing (in tcp_input), but not held in the tcpcb.
 198  * It's basically used to reduce the number of parameters
 199  * to tcp_dooptions.
 200  */
 201 struct tcpopt {
 202         u_long          to_flags;       /* which options are present */
 203 #define TOF_TS          0x0001          /* timestamp */
 204 #define TOF_CC          0x0002          /* CC and CCnew are exclusive */
 205 #define TOF_CCNEW       0x0004
 206 #define TOF_CCECHO      0x0008
 207 #define TOF_MSS         0x0010
 208 #define TOF_SCALE       0x0020
 209         u_int32_t       to_tsval;
 210         u_int32_t       to_tsecr;
 211         tcp_cc          to_cc;          /* holds CC or CCnew */
 212         tcp_cc          to_ccecho;
 213         u_int16_t       to_mss;
 214         u_int8_t        to_requested_s_scale;
 215         u_int8_t        to_pad;
 216 };
 217
 218 struct syncache {
 219         inp_gen_t       sc_inp_gencnt;          /* pointer check */
 220         struct          tcpcb *sc_tp;           /* tcb for listening socket */
 221         struct          mbuf *sc_ipopts;        /* source route */
 222         struct          in_conninfo sc_inc;     /* addresses */
 223 #define sc_route        sc_inc.inc_route
 224 #define sc_route6       sc_inc.inc6_route
 225         u_int32_t       sc_tsrecent;
 226         tcp_cc          sc_cc_send;             /* holds CC or CCnew */
 227         tcp_cc          sc_cc_recv;
 228         tcp_seq         sc_irs;                 /* seq from peer */
 229         tcp_seq         sc_iss;                 /* our ISS */
 230         u_long          sc_rxttime;             /* retransmit time */
 231         u_int16_t       sc_rxtslot;             /* retransmit counter */
 232         u_int16_t       sc_peer_mss;            /* peer's MSS */
 233         u_int16_t       sc_wnd;                 /* advertised window */
 234         u_int8_t        sc_requested_s_scale:4,
 235                         sc_request_r_scale:4;
 236         u_int8_t        sc_flags;
 237 #define SCF_NOOPT       0x01                    /* no TCP options */
 238 #define SCF_WINSCALE    0x02                    /* negotiated window scaling */
 239 #define SCF_TIMESTAMP   0x04                    /* negotiated timestamps */
 240 #define SCF_CC          0x08                    /* negotiated CC */
 241 #define SCF_UNREACH     0x10                    /* icmp unreachable received */
 242 #define SCF_KEEPROUTE   0x20                    /* keep cloned route */
 243         TAILQ_ENTRY(syncache)   sc_hash;
 244         TAILQ_ENTRY(syncache)   sc_timerq;
 245 };
 246
 247 struct syncache_head {
 248         TAILQ_HEAD(, syncache)  sch_bucket;
 249         u_int           sch_length;
 250 };
 251
 252 /*
 253  * The TAO cache entry which is stored in the protocol family specific
 254  * portion of the route metrics.
 255  */
 256 struct rmxp_tao {
 257         tcp_cc  tao_cc;                 /* latest CC in valid SYN */
 258         tcp_cc  tao_ccsent;             /* latest CC sent to peer */
 259         u_short tao_mssopt;             /* peer's cached MSS */
 260 #ifdef notyet
 261         u_short tao_flags;              /* cache status flags */
 262 #define TAOF_DONT       0x0001          /* peer doesn't understand rfc1644 */
 263 #define TAOF_OK         0x0002          /* peer does understand rfc1644 */
 264 #define TAOF_UNDEF      0               /* we don't know yet */
 265 #endif /* notyet */
 266 };
 267 #define rmx_taop(r)     ((struct rmxp_tao *)(r).rmx_filler)
 268
 269 #define intotcpcb(ip)   ((struct tcpcb *)(ip)->inp_ppcb)
 270 #define sototcpcb(so)   (intotcpcb(sotoinpcb(so)))
 271
 272 /*
 273  * The smoothed round-trip time and estimated variance
 274  * are stored as fixed point numbers scaled by the values below.
 275  * For convenience, these scales are also used in smoothing the average
 276  * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
 277  * With these scales, srtt has 3 bits to the right of the binary point,
 278  * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
 279  * binary point, and is smoothed with an ALPHA of 0.75.
 280  */
 281 #define TCP_RTT_SCALE           32      /* multiplier for srtt; 3 bits frac. */
 282 #define TCP_RTT_SHIFT           5       /* shift for srtt; 3 bits frac. */
 283 #define TCP_RTTVAR_SCALE        16      /* multiplier for rttvar; 2 bits */
 284 #define TCP_RTTVAR_SHIFT        4       /* shift for rttvar; 2 bits */
 285 #define TCP_DELTA_SHIFT         2       /* see tcp_input.c */
 286
 287 /*
 288  * The initial retransmission should happen at rtt + 4 * rttvar.
 289  * Because of the way we do the smoothing, srtt and rttvar
 290  * will each average +1/2 tick of bias.  When we compute
 291  * the retransmit timer, we want 1/2 tick of rounding and
 292  * 1 extra tick because of +-1/2 tick uncertainty in the
 293  * firing of the timer.  The bias will give us exactly the
 294  * 1.5 tick we need.  But, because the bias is
 295  * statistical, we have to test that we don't drop below
 296  * the minimum feasible timer (which is 2 ticks).
 297  * This version of the macro adapted from a paper by Lawrence
 298  * Brakmo and Larry Peterson which outlines a problem caused
 299  * by insufficient precision in the original implementation,
 300  * which results in inappropriately large RTO values for very
 301  * fast networks.
 302  */
 303 #define TCP_REXMTVAL(tp) \
 304         max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
 305           + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
 306
 307 /*
 308  * TCP statistics.
 309  * Many of these should be kept per connection,
 310  * but that's inconvenient at the moment.
 311  */
 312 struct  tcpstat {
 313         u_long  tcps_connattempt;       /* connections initiated */
 314         u_long  tcps_accepts;           /* connections accepted */
 315         u_long  tcps_connects;          /* connections established */
 316         u_long  tcps_drops;             /* connections dropped */
 317         u_long  tcps_conndrops;         /* embryonic connections dropped */
 318         u_long  tcps_closed;            /* conn. closed (includes drops) */
 319         u_long  tcps_segstimed;         /* segs where we tried to get rtt */
 320         u_long  tcps_rttupdated;        /* times we succeeded */
 321         u_long  tcps_delack;            /* delayed acks sent */
 322         u_long  tcps_timeoutdrop;       /* conn. dropped in rxmt timeout */
 323         u_long  tcps_rexmttimeo;        /* retransmit timeouts */
 324         u_long  tcps_persisttimeo;      /* persist timeouts */
 325         u_long  tcps_keeptimeo;         /* keepalive timeouts */
 326         u_long  tcps_keepprobe;         /* keepalive probes sent */
 327         u_long  tcps_keepdrops;         /* connections dropped in keepalive */
 328
 329         u_long  tcps_sndtotal;          /* total packets sent */
 330         u_long  tcps_sndpack;           /* data packets sent */
 331         u_long  tcps_sndbyte;           /* data bytes sent */
 332         u_long  tcps_sndrexmitpack;     /* data packets retransmitted */
 333         u_long  tcps_sndrexmitbyte;     /* data bytes retransmitted */
 334         u_long  tcps_sndfastrexmit;     /* Fast Retransmissions */
 335         u_long  tcps_sndearlyrexmit;    /* early Fast Retransmissions */
 336         u_long  tcps_sndlimited;        /* Limited Transmit packets */
 337         u_long  tcps_sndrtobad;         /* spurious RTO retransmissions */
 338         u_long  tcps_sndfastrexmitbad;  /* spurious Fast Retransmissions */
 339         u_long  tcps_sndearlyrexmitbad; /* spurious early Fast Retransmissions,
 340                                            a subset of tcps_sndfastrexmitbad */
 341         u_long  tcps_eifeldetected;     /* Eifel-detected spurious rexmits */
 342         u_long  tcps_rttcantdetect;     /* Eifel but not 1/2 RTT-detectable */
 343         u_long  tcps_rttdetected;       /* RTT-detected spurious RTO rexmits */
 344         u_long  tcps_sndacks;           /* ack-only packets sent */
 345         u_long  tcps_sndprobe;          /* window probes sent */
 346         u_long  tcps_sndurg;            /* packets sent with URG only */
 347         u_long  tcps_sndwinup;          /* window update-only packets sent */
 348         u_long  tcps_sndctrl;           /* control (SYN|FIN|RST) packets sent */
 349
 350         u_long  tcps_rcvtotal;          /* total packets received */
 351         u_long  tcps_rcvpack;           /* packets received in sequence */
 352         u_long  tcps_rcvbyte;           /* bytes received in sequence */
 353         u_long  tcps_rcvbadsum;         /* packets received with ccksum errs */
 354         u_long  tcps_rcvbadoff;         /* packets received with bad offset */
 355         u_long  tcps_rcvmemdrop;        /* packets dropped for lack of memory */
 356         u_long  tcps_rcvshort;          /* packets received too short */
 357         u_long  tcps_rcvduppack;        /* duplicate-only packets received */
 358         u_long  tcps_rcvdupbyte;        /* duplicate-only bytes received */
 359         u_long  tcps_rcvpartduppack;    /* packets with some duplicate data */
 360         u_long  tcps_rcvpartdupbyte;    /* dup. bytes in part-dup. packets */
 361         u_long  tcps_rcvoopack;         /* out-of-order packets received */
 362         u_long  tcps_rcvoobyte;         /* out-of-order bytes received */
 363         u_long  tcps_rcvpackafterwin;   /* packets with data after window */
 364         u_long  tcps_rcvbyteafterwin;   /* bytes rcvd after window */
 365         u_long  tcps_rcvafterclose;     /* packets rcvd after "close" */
 366         u_long  tcps_rcvwinprobe;       /* rcvd window probe packets */
 367         u_long  tcps_rcvdupack;         /* rcvd duplicate acks */
 368         u_long  tcps_rcvacktoomuch;     /* rcvd acks for unsent data */
 369         u_long  tcps_rcvackpack;        /* rcvd ack packets */
 370         u_long  tcps_rcvackbyte;        /* bytes acked by rcvd acks */
 371         u_long  tcps_rcvwinupd;         /* rcvd window update packets */
 372         u_long  tcps_pawsdrop;          /* segments dropped due to PAWS */
 373         u_long  tcps_predack;           /* times hdr predict ok for acks */
 374         u_long  tcps_preddat;           /* times hdr predict ok for data pkts */
 375         u_long  tcps_pcbcachemiss;
 376         u_long  tcps_cachedrtt;         /* times cached RTT in route updated */
 377         u_long  tcps_cachedrttvar;      /* times cached rttvar updated */
 378         u_long  tcps_cachedssthresh;    /* times cached ssthresh updated */
 379         u_long  tcps_usedrtt;           /* times RTT initialized from route */
 380         u_long  tcps_usedrttvar;        /* times RTTVAR initialized from rt */
 381         u_long  tcps_usedssthresh;      /* times ssthresh initialized from rt*/
 382         u_long  tcps_persistdrop;       /* timeout in persist state */
 383         u_long  tcps_badsyn;            /* bogus SYN, e.g. premature ACK */
 384         u_long  tcps_mturesent;         /* resends due to MTU discovery */
 385         u_long  tcps_listendrop;        /* listen queue overflows */
 386
 387         u_long  tcps_sc_added;          /* entry added to syncache */
 388         u_long  tcps_sc_retransmitted;  /* syncache entry was retransmitted */
 389         u_long  tcps_sc_dupsyn;         /* duplicate SYN packet */
 390         u_long  tcps_sc_dropped;        /* could not reply to packet */
 391         u_long  tcps_sc_completed;      /* successful extraction of entry */
 392         u_long  tcps_sc_bucketoverflow; /* syncache per-bucket limit hit */
 393         u_long  tcps_sc_cacheoverflow;  /* syncache cache limit hit */
 394         u_long  tcps_sc_reset;          /* RST removed entry from syncache */
 395         u_long  tcps_sc_stale;          /* timed out or listen socket gone */
 396         u_long  tcps_sc_aborted;        /* syncache entry aborted */
 397         u_long  tcps_sc_badack;         /* removed due to bad ACK */
 398         u_long  tcps_sc_unreach;        /* ICMP unreachable received */
 399         u_long  tcps_sc_zonefail;       /* zalloc() failed */
 400         u_long  tcps_sc_sendcookie;     /* SYN cookie sent */
 401         u_long  tcps_sc_recvcookie;     /* SYN cookie received */
 402 };
 403
 404 /*
 405  * TCB structure exported to user-land via sysctl(3).
 406  * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
 407  * included.  Not all of our clients do.
 408  */
 409 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
 410 struct  xtcpcb {
 411         size_t  xt_len;
 412         struct  inpcb   xt_inp;
 413         struct  tcpcb   xt_tp;
 414         struct  xsocket xt_socket;
 415         u_quad_t        xt_alignment_hack;
 416 };
 417 #endif
 418
 419 /*
 420  * Names for TCP sysctl objects
 421  */
 422 #define TCPCTL_DO_RFC1323       1       /* use RFC-1323 extensions */
 423 #define TCPCTL_DO_RFC1644       2       /* use RFC-1644 extensions */
 424 #define TCPCTL_MSSDFLT          3       /* MSS default */
 425 #define TCPCTL_STATS            4       /* statistics (read-only) */
 426 #define TCPCTL_RTTDFLT          5       /* default RTT estimate */
 427 #define TCPCTL_KEEPIDLE         6       /* keepalive idle timer */
 428 #define TCPCTL_KEEPINTVL        7       /* interval to send keepalives */
 429 #define TCPCTL_SENDSPACE        8       /* send buffer space */
 430 #define TCPCTL_RECVSPACE        9       /* receive buffer space */
 431 #define TCPCTL_KEEPINIT         10      /* timeout for establishing syn */
 432 #define TCPCTL_PCBLIST          11      /* list of all outstanding PCBs */
 433 #define TCPCTL_DELACKTIME       12      /* time before sending delayed ACK */
 434 #define TCPCTL_V6MSSDFLT        13      /* MSS default for IPv6 */
 435 #define TCPCTL_MAXID            14
 436
 437 #define TCPCTL_NAMES { \
 438         { 0, 0 }, \
 439         { "rfc1323", CTLTYPE_INT }, \
 440         { "rfc1644", CTLTYPE_INT }, \
 441         { "mssdflt", CTLTYPE_INT }, \
 442         { "stats", CTLTYPE_STRUCT }, \
 443         { "rttdflt", CTLTYPE_INT }, \
 444         { "keepidle", CTLTYPE_INT }, \
 445         { "keepintvl", CTLTYPE_INT }, \
 446         { "sendspace", CTLTYPE_INT }, \
 447         { "recvspace", CTLTYPE_INT }, \
 448         { "keepinit", CTLTYPE_INT }, \
 449         { "pcblist", CTLTYPE_STRUCT }, \
 450         { "delacktime", CTLTYPE_INT }, \
 451         { "v6mssdflt", CTLTYPE_INT }, \
 452 }
 453
 454 #ifdef _KERNEL
 455 #ifdef SYSCTL_DECL
 456 SYSCTL_DECL(_net_inet_tcp);
 457 #endif
 458
 459 extern  struct inpcbinfo tcbinfo[];
 460 extern  struct tcpstat tcpstat; /* tcp statistics */
 461 extern  int tcp_mssdflt;        /* XXX */
 462 extern  int tcp_delack_enabled;
 463 extern  int tcp_do_newreno;
 464 extern  int path_mtu_discovery;
 465 extern  int ss_fltsz;
 466 extern  int ss_fltsz_local;
 467
 468 int      tcp_addrcpu(in_addr_t faddr, in_port_t fport,
 469             in_addr_t laddr, in_port_t lport);
 470 void     tcp_canceltimers (struct tcpcb *);
 471 struct tcpcb *
 472          tcp_close (struct tcpcb *);
 473 void     tcp_ctlinput (int, struct sockaddr *, void *);
 474 int      tcp_ctloutput (struct socket *, struct sockopt *);
 475 struct lwkt_port *
 476          tcp_cport(int cpu);
 477 struct tcpcb *
 478          tcp_drop (struct tcpcb *, int);
 479 void     tcp_drain (void);
 480 void     tcp_fasttimo (void);
 481 struct rmxp_tao *
 482          tcp_gettaocache (struct in_conninfo *);
 483 void     tcp_init (void);
 484 void     tcp_thread_init (void);
 485 void     tcp_input (struct mbuf *, int, int);
 486 void     tcp_mss (struct tcpcb *, int);
 487 int      tcp_mssopt (struct tcpcb *);
 488 void     tcp_drop_syn_sent (struct inpcb *, int);
 489 void     tcp_mtudisc (struct inpcb *, int);
 490 struct tcpcb *
 491          tcp_newtcpcb (struct inpcb *);
 492 int      tcp_output (struct tcpcb *);
 493 void     tcp_quench (struct inpcb *, int);
 494 void     tcp_respond (struct tcpcb *, void *,
 495             struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
 496 struct rtentry *
 497          tcp_rtlookup (struct in_conninfo *);
 498 void     tcp_save_congestion_state(struct tcpcb *tp);
 499 void     tcp_revert_congestion_state(struct tcpcb *tp);
 500 void     tcp_setpersist (struct tcpcb *);
 501 void     tcp_slowtimo (void);
 502 struct tcptemp *
 503          tcp_maketemplate (struct tcpcb *);
 504 void     tcp_fillheaders (struct tcpcb *, void *, void *);
 505 struct lwkt_port *
 506          tcp_soport(struct socket *, struct sockaddr *nam);
 507 struct tcpcb *
 508          tcp_timers (struct tcpcb *, int);
 509 void     tcp_trace (int, int, struct tcpcb *, void *, struct tcphdr *,
 510                         int);
 511 void     tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq);
 512 void     syncache_init(void);
 513 void     syncache_unreach(struct in_conninfo *, struct tcphdr *);
 514 int      syncache_expand(struct in_conninfo *, struct tcphdr *,
 515              struct socket **, struct mbuf *);
 516 int      syncache_add(struct in_conninfo *, struct tcpopt *,
 517              struct tcphdr *, struct socket **, struct mbuf *);
 518 void     syncache_chkrst(struct in_conninfo *, struct tcphdr *);
 519 void     syncache_badack(struct in_conninfo *);
 520
 521 extern  struct pr_usrreqs tcp_usrreqs;
 522 extern  u_long tcp_sendspace;
 523 extern  u_long tcp_recvspace;
 524 tcp_seq tcp_new_isn (struct tcpcb *);
 525
 526 #endif /* _KERNEL */
 527
 528 #endif /* _NETINET_TCP_VAR_H_ */