/*      $OpenBSD: tcp_var.h,v 1.196 2025/09/16 17:29:35 bluhm Exp $     */
/*      $NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos Exp $    */

/*
 * Copyright (c) 1982, 1986, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)tcp_var.h   8.3 (Berkeley) 4/10/94
 */

#ifndef _NETINET_TCP_VAR_H_
#define _NETINET_TCP_VAR_H_

#include <sys/timeout.h>

/*
 * Kernel variables for tcp.
 */

struct sackblk {
        tcp_seq start;          /* start seq no. of sack block */
        tcp_seq end;            /* end seq no. */
};

struct sackhole {
        tcp_seq start;          /* start seq no. of hole */
        tcp_seq end;            /* end seq no. */
        int     dups;           /* number of dup(s)acks for this hole */
        tcp_seq rxmit;          /* next seq. no in hole to be retransmitted */
        struct sackhole *next;  /* next in list */
};

/*
 * TCP sequence queue structures.
 */
TAILQ_HEAD(tcpqehead, tcpqent);
struct tcpqent {
        TAILQ_ENTRY(tcpqent) tcpqe_q;
        struct tcphdr   *tcpqe_tcp;
        struct mbuf     *tcpqe_m;       /* mbuf contains packet */
};

/*
 * Tcp control block, one per tcp; fields:
 */
struct tcpcb {
        struct tcpqehead t_segq;                /* sequencing queue */
        struct timeout t_timer[TCPT_NTIMERS];   /* tcp timers */
        short   t_state;                /* state of this connection */
        short   t_rxtshift;             /* log(2) of rexmt exp. backoff */
        int     t_rxtcur;               /* current retransmit value */
        short   t_dupacks;              /* consecutive dup acks recd */
        u_short t_maxseg;               /* maximum segment size */
        char    t_force;                /* 1 if forcing out a byte */
        u_int   t_flags;
#define TF_ACKNOW       0x0001U         /* ack peer immediately */
#define TF_NODELAY      0x0004U         /* don't delay packets to coalesce */
#define TF_NOOPT        0x0008U         /* don't use tcp options */
#define TF_SENTFIN      0x0010U         /* have sent FIN */
#define TF_REQ_SCALE    0x0020U         /* have/will request window scaling */
#define TF_RCVD_SCALE   0x0040U         /* other side has requested scaling */
#define TF_REQ_TSTMP    0x0080U         /* have/will request timestamps */
#define TF_RCVD_TSTMP   0x0100U         /* a timestamp was received in SYN */
#define TF_SACK_PERMIT  0x0200U         /* other side said I could SACK */
#define TF_SIGNATURE    0x0400U         /* require TCP MD5 signature */
#ifdef TCP_ECN
#define TF_ECN_PERMIT   0x00008000U     /* other side said I could ECN */
#define TF_RCVD_CE      0x00010000U     /* send ECE in subsequent segs */
#define TF_SEND_CWR     0x00020000U     /* send CWR in next seg */
#define TF_DISABLE_ECN  0x00040000U     /* disable ECN for this connection */
#endif
#define TF_LASTIDLE     0x00100000U     /* no outstanding ACK on last send */
#define TF_PMTUD_PEND   0x00400000U     /* Path MTU Discovery pending */
#define TF_NEEDOUTPUT   0x00800000U     /* call tcp_output after tcp_input */
#define TF_NOPUSH       0x02000000U     /* don't push */
#define TF_TMR_REXMT    0x04000000U     /* retransmit timer armed */
#define TF_TMR_PERSIST  0x08000000U     /* retransmit persistence timer armed */
#define TF_TMR_KEEP     0x10000000U     /* keep alive timer armed */
#define TF_TMR_2MSL     0x20000000U     /* 2*msl quiet time timer armed */
#define TF_TMR_DELACK   0x40000000U     /* delayed ack timer armed */
#define TF_TIMER        TF_TMR_REXMT    /* used to shift with TCPT values */

        struct  mbuf *t_template;       /* skeletal packet for transmit */
        struct  inpcb *t_inpcb;         /* back pointer to internet pcb */
/*
 * The following fields are used as in the protocol specification.
 * See RFC793, Dec. 1981, page 21.
 */
/* send sequence variables */
        tcp_seq snd_una;                /* send unacknowledged */
        tcp_seq snd_nxt;                /* send next */
        tcp_seq snd_up;                 /* send urgent pointer */
        tcp_seq snd_wl1;                /* window update seg seq number */
        tcp_seq snd_wl2;                /* window update seg ack number */
        tcp_seq iss;                    /* initial send sequence number */
        u_long  snd_wnd;                /* send window */
        int     sack_enable;            /* enable SACK for this connection */
        int     snd_numholes;           /* number of holes seen by sender */
        struct sackhole *snd_holes;     /* linked list of holes (sorted) */
        tcp_seq snd_last;               /* for use in fast recovery */
/* receive sequence variables */
        u_long  rcv_wnd;                /* receive window */
        tcp_seq rcv_nxt;                /* receive next */
        tcp_seq rcv_up;                 /* receive urgent pointer */
        tcp_seq irs;                    /* initial receive sequence number */
        tcp_seq rcv_lastsack;           /* last seq number(+1) sack'd by rcv'r*/
        int     rcv_numsacks;           /* # distinct sack blks present */
        struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */

/*
 * Additional variables for this implementation.
 */
/* receive variables */
        tcp_seq rcv_adv;                /* advertised window */
/* retransmit variables */
        tcp_seq snd_max;                /* highest sequence number sent;
                                         * used to recognize retransmits
                                         */
/* congestion control (for slow start, source quench, retransmit after loss) */
        u_long  snd_cwnd;               /* congestion-controlled window */
        u_long  snd_ssthresh;           /* snd_cwnd size threshold for
                                         * for slow start exponential to
                                         * linear switch
                                         */

/* auto-sizing variables */
        uint64_t rfbuf_ts;      /* recv buffer autoscaling time stamp */
        u_int   rfbuf_cnt;      /* recv buffer autoscaling byte count */

        u_short t_maxopd;               /* mss plus options */
        u_short t_peermss;              /* peer's maximum segment size */

/*
 * transmit timing stuff.  See below for scale of srtt and rttvar.
 * "Variance" is actually smoothed difference.
 */
        uint64_t t_rcvtime;             /* time last segment received */
        uint64_t t_rcvacktime;          /* time last ack received */
        uint64_t t_sndtime;             /* time last segment sent */
        uint64_t t_sndacktime;          /* time last ack sent */
        uint64_t t_rtttime;             /* time we started measuring rtt */
        tcp_seq t_rtseq;                /* sequence number being timed */
        int     t_srtt;                 /* smoothed round-trip time */
        int     t_rttvar;               /* variance in round-trip time */
        u_int   t_rttmin;               /* minimum rtt allowed */
        u_long  max_sndwnd;             /* largest window peer has offered */

/* out-of-band data */
        char    t_oobflags;             /* have some */
        char    t_iobc;                 /* input character */
#define TCPOOB_HAVEDATA 0x01
#define TCPOOB_HADDATA  0x02
        short   t_softerror;            /* possible error not yet reported */

/* RFC 1323 variables */
        u_char  snd_scale;              /* window scaling for send window */
        u_char  rcv_scale;              /* window scaling for recv window */
        u_char  request_r_scale;        /* pending window scaling */
        u_char  requested_s_scale;
        uint32_t ts_recent;             /* timestamp echo data */
        uint32_t ts_modulate;           /* modulation on timestamp */
        uint64_t ts_recent_age;         /* when last updated */
        tcp_seq last_ack_sent;

/* pointer for syn cache entries*/
        LIST_HEAD(, syn_cache) t_sc;    /* list of entries by this tcb */

/* Path-MTU Discovery Information */
        u_int   t_pmtud_mss_acked;      /* MSS acked, lower bound for MTU */
        u_int   t_pmtud_mtu_sent;       /* MTU used, upper bound for MTU */
        tcp_seq t_pmtud_th_seq;         /* TCP SEQ from ICMP payload */
        u_int   t_pmtud_nextmtu;        /* Advertised Next-Hop MTU from ICMP */
        u_short t_pmtud_ip_len;         /* IP length from ICMP payload */
        u_short t_pmtud_ip_hl;          /* IP header length from ICMP payload */

        int pf;

/* maintain a few stats per connection: */
        u_int   t_rcvoopack;            /* out-of-order packets received */
        u_int   t_sndrexmitpack;        /* retransmit packets sent */
        u_int   t_sndzerowin;           /* zero-window updates sent */
};

#define intotcpcb(ip)   ((struct tcpcb *)(ip)->inp_ppcb)
#define sototcpcb(so)   (intotcpcb(sotoinpcb(so)))

#ifdef _KERNEL
/*
 * Handy way of passing around TCP option info.
 */
struct tcp_opt_info {
        int             ts_present;
        u_int32_t       ts_val;
        u_int32_t       ts_ecr;
        u_int16_t       maxseg;
};

/*
 * Data for the TCP compressed state engine.
 */

/*
 * Locks used to protect global data and struct members:
 *      I       immutable after creation
 *      N       net lock
 *      S       syn_cache_mtx           tcp syn cache global mutex
 *      s       so_lock                 socket lock of listen socket
 */

extern struct mutex syn_cache_mtx;

#define TCP_SYN_HASH_SIZE       293
#define TCP_SYN_BUCKET_SIZE     35

union syn_cache_sa {
        struct sockaddr sa;
        struct sockaddr_in sin;
        struct sockaddr_in6 sin6;
};

struct syn_cache {
        TAILQ_ENTRY(syn_cache) sc_bucketq;      /* [S] link on bucket list */
        struct refcnt sc_refcnt;                /* ref count list and timer */
        struct timeout sc_timer;                /* rexmt timer */
        struct route sc_route;                  /* [s] cached route */
        long sc_win;                            /* [I] advertised window */
        struct syn_cache_head *sc_buckethead;   /* [S] our bucket index */
        struct syn_cache_set *sc_set;           /* [S] our syn cache set */
        u_int64_t sc_timestamp;         /* [s] timestamp from SYN */
        u_int32_t sc_hash;              /* [S] */
        u_int32_t sc_modulate;          /* [I] our timestamp modulator */
        union syn_cache_sa sc_src;      /* [I] */
        union syn_cache_sa sc_dst;      /* [I] */
        tcp_seq sc_irs;                 /* [I] */
        tcp_seq sc_iss;                 /* [I] */
        u_int sc_rtableid;              /* [I] */
        u_int sc_rxtcur;                /* [S] current rxt timeout */
        u_int sc_rxttot;                /* [S] total time spend on queues */
        u_int sc_rxtshift;              /* [S] for computing backoff */
        u_int sc_dynflags;              /* [S] flags accessed with mutex */
#define SCF_UNREACH     0x0001U         /* we've had an unreach error */

        u_short sc_fixflags;            /* [I] set during initialization */
#define SCF_TIMESTAMP   0x0010U         /* peer will do timestamps */
#define SCF_SACK_PERMIT 0x0020U         /* permit sack */
#define SCF_ECN_PERMIT  0x0040U         /* permit ecn */
#define SCF_SIGNATURE   0x0080U         /* enforce tcp signatures */

        struct mbuf *sc_ipopts;                 /* [s] IP options */
        u_int16_t sc_peermaxseg;                /* [I] */
        u_int16_t sc_ourmaxseg;                 /* [I] */
        u_int     sc_request_r_scale    : 4,    /* [I] */
                  sc_requested_s_scale  : 4;    /* [I] */

        struct inpcb *sc_inplisten;     /* [S] inpcb for listening socket */
        LIST_ENTRY(syn_cache) sc_tpq;   /* [S] list of entries by same tp */
};

struct syn_cache_head {
        TAILQ_HEAD(, syn_cache) sch_bucket;     /* [S] bucket entries */
        u_short sch_length;                     /* [S] # entries in bucket */
};

struct syn_cache_set {
        struct          syn_cache_head *scs_buckethead; /* [S] */
        long            scs_use;        /* [S] */
        int             scs_size;       /* [S] current size of hash table */
        int             scs_count;      /* [S] */
        u_int32_t       scs_random[5];  /* [S] */
};

#endif /* _KERNEL */

/*
 * The smoothed round-trip time and estimated variance
 * are stored as fixed point numbers scaled by the values below.
 * For convenience, these scales are also used in smoothing the average
 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
 * With these scales, srtt has 5 bits to the right of the binary point,
 * and thus an "ALPHA" of 0.875.  rttvar has 4 bits to the right of the
 * binary point, and is smoothed with an ALPHA of 0.75.
 */
#define TCP_RTT_SHIFT           3       /* shift for srtt; 5 bits frac. */
#define TCP_RTTVAR_SHIFT        2       /* shift for rttvar; 4 bits */
#define TCP_RTT_BASE_SHIFT      2       /* remaining 2 bit shift */
#define TCP_RTT_MAX             (1<<18) /* maximum rtt */

/*
 * The initial retransmission should happen at rtt + 4 * rttvar.
 * Because of the way we do the smoothing, srtt and rttvar
 * will each average +1/2 tick of bias.  When we compute
 * the retransmit timer, we want 1/2 tick of rounding and
 * 1 extra tick because of +-1/2 tick uncertainty in the
 * firing of the timer.  The bias will give us exactly the
 * 1.5 tick we need.  But, because the bias is
 * statistical, we have to test that we don't drop below
 * the minimum feasible timer (which is 2 ticks).
 * This macro assumes that the value of (1 << TCP_RTTVAR_SHIFT)
 * is the same as the multiplier for rttvar.
 */
#define TCP_REXMTVAL(tp) \
        ((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) \
            >> TCP_RTT_BASE_SHIFT)

/*
 * TCP statistics.
 * Many of these should be kept per connection,
 * but that's inconvenient at the moment.
 */
struct  tcpstat {
        u_int32_t tcps_connattempt;     /* connections initiated */
        u_int32_t tcps_accepts;         /* connections accepted */
        u_int32_t tcps_connects;        /* connections established */
        u_int32_t tcps_drops;           /* connections dropped */
        u_int32_t tcps_conndrops;       /* embryonic connections dropped */
        u_int32_t tcps_closed;          /* conn. closed (includes drops) */
        u_int32_t tcps_segstimed;       /* segs where we tried to get rtt */
        u_int32_t tcps_rttupdated;      /* times we succeeded */
        u_int32_t tcps_delack;          /* delayed acks sent */
        u_int32_t tcps_timeoutdrop;     /* conn. dropped in rxmt timeout */
        u_int32_t tcps_rexmttimeo;      /* retransmit timeouts */
        u_int32_t tcps_persisttimeo;    /* persist timeouts */
        u_int32_t tcps_persistdrop;     /* connections dropped in persist */
        u_int32_t tcps_keeptimeo;       /* keepalive timeouts */
        u_int32_t tcps_keepprobe;       /* keepalive probes sent */
        u_int32_t tcps_keepdrops;       /* connections dropped in keepalive */

        u_int32_t tcps_sndtotal;                /* total packets sent */
        u_int32_t tcps_sndpack;         /* data packets sent */
        u_int64_t tcps_sndbyte;         /* data bytes sent */
        u_int32_t tcps_sndrexmitpack;   /* data packets retransmitted */
        u_int64_t tcps_sndrexmitbyte;   /* data bytes retransmitted */
        u_int64_t tcps_sndrexmitfast;   /* Fast retransmits */
        u_int32_t tcps_sndacks;         /* ack-only packets sent */
        u_int32_t tcps_sndprobe;        /* window probes sent */
        u_int32_t tcps_sndurg;          /* packets sent with URG only */
        u_int32_t tcps_sndwinup;        /* window update-only packets sent */
        u_int32_t tcps_sndctrl;         /* control (SYN|FIN|RST) packets sent */

        u_int32_t tcps_rcvtotal;        /* total packets received */
        u_int32_t tcps_rcvpack;         /* packets received in sequence */
        u_int64_t tcps_rcvbyte;         /* bytes received in sequence */
        u_int32_t tcps_rcvbadsum;       /* packets received with ccksum errs */
        u_int32_t tcps_rcvbadoff;       /* packets received with bad offset */
        u_int32_t tcps_rcvmemdrop;      /* packets dropped for lack of memory */
        u_int32_t tcps_rcvnosec;        /* packets dropped for lack of ipsec */
        u_int32_t tcps_rcvshort;        /* packets received too short */
        u_int32_t tcps_rcvduppack;      /* duplicate-only packets received */
        u_int64_t tcps_rcvdupbyte;      /* duplicate-only bytes received */
        u_int32_t tcps_rcvpartduppack;  /* packets with some duplicate data */
        u_int64_t tcps_rcvpartdupbyte;  /* dup. bytes in part-dup. packets */
        u_int32_t tcps_rcvoopack;       /* out-of-order packets received */
        u_int64_t tcps_rcvoobyte;       /* out-of-order bytes received */
        u_int32_t tcps_rcvpackafterwin; /* packets with data after window */
        u_int64_t tcps_rcvbyteafterwin; /* bytes rcvd after window */
        u_int32_t tcps_rcvafterclose;   /* packets rcvd after "close" */
        u_int32_t tcps_rcvwinprobe;     /* rcvd window probe packets */
        u_int32_t tcps_rcvdupack;       /* rcvd duplicate acks */
        u_int32_t tcps_rcvacktoomuch;   /* rcvd acks for unsent data */
        u_int32_t tcps_rcvacktooold;    /* rcvd acks for old data */
        u_int32_t tcps_rcvackpack;      /* rcvd ack packets */
        u_int64_t tcps_rcvackbyte;      /* bytes acked by rcvd acks */
        u_int32_t tcps_rcvwinupd;       /* rcvd window update packets */
        u_int32_t tcps_pawsdrop;        /* segments dropped due to PAWS */
        u_int32_t tcps_predack;         /* times hdr predict ok for acks */
        u_int32_t tcps_preddat;         /* times hdr predict ok for data pkts */

        u_int32_t tcps_pcbhashmiss;     /* input packets missing pcb hash */
        u_int32_t tcps_noport;          /* no socket on port */
        u_int32_t tcps_closing;         /* inpcb exists, socket is closing */
        u_int32_t tcps_badsyn;          /* SYN packet with src==dst rcv'ed */
        u_int32_t tcps_dropsyn;         /* SYN packet dropped */

        u_int32_t tcps_rcvbadsig;       /* rcvd bad/missing TCP signatures */
        u_int64_t tcps_rcvgoodsig;      /* rcvd good TCP signatures */
        u_int32_t tcps_inswcsum;        /* input software-checksummed pkts */
        u_int32_t tcps_outswcsum;       /* output software-checksummed pkts */

        /* ECN stats */
        u_int32_t tcps_ecn_accepts;     /* ecn connections accepted */
        u_int32_t tcps_ecn_rcvece;      /* # of rcvd ece */
        u_int32_t tcps_ecn_rcvcwr;      /* # of rcvd cwr */
        u_int32_t tcps_ecn_rcvce;       /* # of rcvd ce in ip header */
        u_int32_t tcps_ecn_sndect;      /* # of cwr sent */
        u_int32_t tcps_ecn_sndece;      /* # of ece sent */
        u_int32_t tcps_ecn_sndcwr;      /* # of cwr sent */
        u_int32_t tcps_cwr_ecn;         /* # of cwnd reduced by ecn */
        u_int32_t tcps_cwr_frecovery;   /* # of cwnd reduced by fastrecovery */
        u_int32_t tcps_cwr_timeout;     /* # of cwnd reduced by timeout */

        /* These statistics deal with the SYN cache. */
        u_int64_t tcps_sc_added;        /* # of entries added */
        u_int64_t tcps_sc_completed;    /* # of connections completed */
        u_int64_t tcps_sc_timed_out;    /* # of entries timed out */
        u_int64_t tcps_sc_overflowed;   /* # dropped due to overflow */
        u_int64_t tcps_sc_reset;        /* # dropped due to RST */
        u_int64_t tcps_sc_unreach;      /* # dropped due to ICMP unreach */
        u_int64_t tcps_sc_bucketoverflow;/* # dropped due to bucket overflow */
        u_int64_t tcps_sc_aborted;      /* # of entries aborted (no mem) */
        u_int64_t tcps_sc_dupesyn;      /* # of duplicate SYNs received */
        u_int64_t tcps_sc_dropped;      /* # of SYNs dropped (no route/mem) */
        u_int64_t tcps_sc_collisions;   /* # of hash collisions */
        u_int64_t tcps_sc_retransmitted;/* # of retransmissions */
        u_int64_t tcps_sc_seedrandom;   /* # of syn cache seeds with random */
        u_int64_t tcps_sc_hash_size;    /* hash buckets in current syn cache */
        u_int64_t tcps_sc_entry_count;  /* # of entries in current syn cache */
        u_int64_t tcps_sc_entry_limit;  /* limit of syn cache entries */
        u_int64_t tcps_sc_bucket_maxlen;/* maximum # of entries in any bucket */
        u_int64_t tcps_sc_bucket_limit; /* limit of syn cache bucket list */
        int64_t tcps_sc_uses_left;      /* use counter of current syn cache */

        u_int64_t tcps_conndrained;     /* # of connections drained */

        u_int64_t tcps_sack_recovery_episode;   /* SACK recovery episodes */
        u_int64_t tcps_sack_rexmits;            /* SACK rexmit segments */
        u_int64_t tcps_sack_rexmit_bytes;       /* SACK rexmit bytes */
        u_int64_t tcps_sack_rcv_opts;           /* SACK options received */
        u_int64_t tcps_sack_snd_opts;           /* SACK options sent */
        u_int64_t tcps_sack_drop_opts;          /* SACK options dropped */

        u_int32_t tcps_outswtso;        /* output tso chopped in software */
        u_int32_t tcps_outhwtso;        /* output tso processed by hardware */
        u_int32_t tcps_outpkttso;       /* packets generated by tso */
        u_int32_t tcps_outbadtso;       /* output tso failed, packet dropped */
        u_int32_t tcps_inswlro;         /* input lro on pseudo device */
        u_int32_t tcps_inhwlro;         /* input lro from hardware */
        u_int32_t tcps_inpktlro;        /* packets coalesced by hardware lro */
        u_int32_t tcps_inbadlro;        /* input bad lro packets */
};

/*
 * Names for TCP sysctl objects.
 */

#define TCPCTL_RFC1323          1 /* enable RFC1323 timestamps/scaling */
#define TCPCTL_KEEPINITTIME     2 /* TCPT_KEEP value */
#define TCPCTL_KEEPIDLE         3 /* allow tcp_keepidle to be changed */
#define TCPCTL_KEEPINTVL        4 /* allow tcp_keepintvl to be changed */
#define TCPCTL_SLOWHZ           5 /* return kernel idea of PR_SLOWHZ */
#define TCPCTL_BADDYNAMIC       6 /* return bad dynamic port bitmap */
#define TCPCTL_RECVSPACE        7 /* receive buffer space */
#define TCPCTL_SENDSPACE        8 /* send buffer space */
#define TCPCTL_IDENT            9 /* get connection owner */
#define TCPCTL_SACK            10 /* selective acknowledgement, rfc 2018 */
#define TCPCTL_MSSDFLT         11 /* Default maximum segment size */
#define TCPCTL_RSTPPSLIMIT     12 /* RST pps limit */
#define TCPCTL_ACK_ON_PUSH     13 /* ACK immediately on PUSH */
#define TCPCTL_ECN             14 /* RFC3168 ECN */
#define TCPCTL_SYN_CACHE_LIMIT 15 /* max size of comp. state engine */
#define TCPCTL_SYN_BUCKET_LIMIT 16 /* max size of hash bucket */
#define TCPCTL_RFC3390         17 /* enable/disable RFC3390 increased cwnd */
#define TCPCTL_REASS_LIMIT     18 /* max entries for tcp reass queues */
#define TCPCTL_DROP            19 /* drop tcp connection */
#define TCPCTL_SACKHOLE_LIMIT  20 /* max entries for tcp sack queues */
#define TCPCTL_STATS           21 /* TCP statistics */
#define TCPCTL_ALWAYS_KEEPALIVE 22 /* assume SO_KEEPALIVE is always set */
#define TCPCTL_SYN_USE_LIMIT   23 /* number of uses before reseeding hash */
#define TCPCTL_ROOTONLY        24 /* return root only port bitmap */
#define TCPCTL_SYN_HASH_SIZE   25 /* number of buckets in the hash */
#define TCPCTL_TSO             26 /* enable TCP segmentation offload */
#define TCPCTL_MAXID           27

#define TCPCTL_NAMES { \
        { 0, 0 }, \
        { "rfc1323",    CTLTYPE_INT }, \
        { "keepinittime",       CTLTYPE_INT }, \
        { "keepidle",   CTLTYPE_INT }, \
        { "keepintvl",  CTLTYPE_INT }, \
        { NULL, 0 }, \
        { "baddynamic", CTLTYPE_STRUCT }, \
        { NULL, 0 }, \
        { NULL, 0 }, \
        { "ident",      CTLTYPE_STRUCT }, \
        { "sack",       CTLTYPE_INT }, \
        { "mssdflt",    CTLTYPE_INT }, \
        { "rstppslimit",        CTLTYPE_INT }, \
        { "ackonpush",  CTLTYPE_INT }, \
        { "ecn",        CTLTYPE_INT }, \
        { "syncachelimit",      CTLTYPE_INT }, \
        { "synbucketlimit",     CTLTYPE_INT }, \
        { "rfc3390",    CTLTYPE_INT }, \
        { "reasslimit", CTLTYPE_INT }, \
        { "drop",       CTLTYPE_STRUCT }, \
        { "sackholelimit",      CTLTYPE_INT }, \
        { "stats",      CTLTYPE_STRUCT }, \
        { "always_keepalive",   CTLTYPE_INT }, \
        { "synuselimit",        CTLTYPE_INT }, \
        { "rootonly",   CTLTYPE_STRUCT }, \
        { "synhashsize",        CTLTYPE_INT }, \
        { "tso",        CTLTYPE_INT }, \
}

struct tcp_ident_mapping {
        struct sockaddr_storage faddr, laddr;
        int euid, ruid;
        u_int rdomain;
};

#ifdef _KERNEL

#include <sys/percpu.h>
#include <sys/stat.h>

enum tcpstat_counters {
        tcps_connattempt,
        tcps_accepts,
        tcps_connects,
        tcps_drops,
        tcps_conndrops,
        tcps_closed,
        tcps_segstimed,
        tcps_rttupdated,
        tcps_delack,
        tcps_timeoutdrop,
        tcps_rexmttimeo,
        tcps_persisttimeo,
        tcps_persistdrop,
        tcps_keeptimeo,
        tcps_keepprobe,
        tcps_keepdrops,
        tcps_sndtotal,
        tcps_sndpack,
        tcps_sndbyte,
        tcps_sndrexmitpack,
        tcps_sndrexmitbyte,
        tcps_sndrexmitfast,
        tcps_sndacks,
        tcps_sndprobe,
        tcps_sndurg,
        tcps_sndwinup,
        tcps_sndctrl,
        tcps_rcvtotal,
        tcps_rcvpack,
        tcps_rcvbyte,
        tcps_rcvbadsum,
        tcps_rcvbadoff,
        tcps_rcvmemdrop,
        tcps_rcvnosec,
        tcps_rcvshort,
        tcps_rcvduppack,
        tcps_rcvdupbyte,
        tcps_rcvpartduppack,
        tcps_rcvpartdupbyte,
        tcps_rcvoopack,
        tcps_rcvoobyte,
        tcps_rcvpackafterwin,
        tcps_rcvbyteafterwin,
        tcps_rcvafterclose,
        tcps_rcvwinprobe,
        tcps_rcvdupack,
        tcps_rcvacktoomuch,
        tcps_rcvacktooold,
        tcps_rcvackpack,
        tcps_rcvackbyte,
        tcps_rcvwinupd,
        tcps_pawsdrop,
        tcps_predack,
        tcps_preddat,
        tcps_pcbhashmiss,
        tcps_noport,
        tcps_closing,
        tcps_badsyn,
        tcps_dropsyn,
        tcps_rcvbadsig,
        tcps_rcvgoodsig,
        tcps_inswcsum,
        tcps_outswcsum,
        tcps_ecn_accepts,
        tcps_ecn_rcvece,
        tcps_ecn_rcvcwr,
        tcps_ecn_rcvce,
        tcps_ecn_sndect,
        tcps_ecn_sndece,
        tcps_ecn_sndcwr,
        tcps_cwr_ecn,
        tcps_cwr_frecovery,
        tcps_cwr_timeout,
        tcps_sc_added,
        tcps_sc_completed,
        tcps_sc_timed_out,
        tcps_sc_overflowed,
        tcps_sc_reset,
        tcps_sc_unreach,
        tcps_sc_bucketoverflow,
        tcps_sc_aborted,
        tcps_sc_dupesyn,
        tcps_sc_dropped,
        tcps_sc_collisions,
        tcps_sc_retransmitted,
        tcps_sc_seedrandom,
        tcps_sc_hash_size,
        tcps_sc_entry_count,
        tcps_sc_entry_limit,
        tcps_sc_bucket_maxlen,
        tcps_sc_bucket_limit,
        tcps_sc_uses_left,
        tcps_conndrained,
        tcps_sack_recovery_episode,
        tcps_sack_rexmits,
        tcps_sack_rexmit_bytes,
        tcps_sack_rcv_opts,
        tcps_sack_snd_opts,
        tcps_sack_drop_opts,
        tcps_outswtso,
        tcps_outhwtso,
        tcps_outpkttso,
        tcps_outbadtso,
        tcps_inswlro,
        tcps_inhwlro,
        tcps_inpktlro,
        tcps_inbadlro,
        tcps_ncounters,
};

extern struct cpumem *tcpcounters;

static inline void
tcpstat_inc(enum tcpstat_counters c)
{
        int s = splnet();
        counters_inc(tcpcounters, c);
        splx(s);
}

static inline void
tcpstat_add(enum tcpstat_counters c, uint64_t v)
{
        int s = splnet();
        counters_add(tcpcounters, c, v);
        splx(s);
}

static inline void
tcpstat_pkt(enum tcpstat_counters pcounter, enum tcpstat_counters bcounter,
    uint64_t v)
{
        int s = splnet();
        counters_pkt(tcpcounters, pcounter, bcounter, v);
        splx(s);
}

extern uint64_t tcp_starttime;

static inline uint64_t
tcp_now(void)
{
        /* TCP time ticks in 63 bit milliseconds with 63 bit random offset. */
        return tcp_starttime + (getnsecruntime() / 1000000ULL);
}

#define TCP_TIME(_sec)  ((_sec) * 1000) /* tcp_now() is in milliseconds */

extern  struct mutex tcp_timer_mtx;
extern  const struct pr_usrreqs tcp_usrreqs;

#ifdef INET6
extern  const struct pr_usrreqs tcp6_usrreqs;
#endif

extern  struct pool tcpcb_pool;
extern  struct inpcbtable tcbtable, tcb6table;  /* queue of active tcpcb's */
extern  int tcp_do_rfc1323;     /* [a] enabled/disabled? */
extern  const int tcprexmtthresh;
extern  int tcp_mssdflt;        /* [a] default maximum segment size */
extern  int tcp_rst_ppslim;     /* [a] maximum outgoing RST packet per second */
extern  int tcp_ack_on_push;    /* [a] ACK immediately on PUSH */
extern  int tcp_do_sack;        /* [a] SACK enabled/disabled */
extern  struct pool sackhl_pool;
extern  int tcp_sackhole_limit; /* max entries for tcp sack queues */
extern  int tcp_do_ecn;         /* [a] RFC3168 ECN enabled/disabled? */
extern  int tcp_do_rfc3390;     /* [a] RFC3390 Increasing TCP Initial Window */
extern  int tcp_do_tso;         /* [a] enable TSO for TCP output packets */

extern  struct pool tcpqe_pool;
extern  int tcp_reass_limit;    /* max entries for tcp reass queues */

extern  int tcp_syn_hash_size;  /* adjustable size of the hash array */
extern  int tcp_syn_cache_limit; /* max entries for compressed state engine */
extern  int tcp_syn_bucket_limit;/* max entries per hash bucket */
extern  int tcp_syn_use_limit;   /* number of uses before reseeding hash */
extern  struct syn_cache_set tcp_syn_cache[];
extern  int tcp_syn_cache_active; /* active syn cache, may be 0 or 1 */

struct tdb;

void     tcp_canceltimers(struct tcpcb *);
struct tcpcb *
         tcp_close(struct tcpcb *);
int      tcp_freeq(struct tcpcb *);
#ifdef INET6
void     tcp6_ctlinput(int, struct sockaddr *, u_int, void *);
#endif
void     tcp_ctlinput(int, struct sockaddr *, u_int, void *);
int      tcp_ctloutput(int, struct socket *, int, int, struct mbuf *);
struct tcpcb *
         tcp_dodisconnect(struct tcpcb *);
struct tcpcb *
         tcp_drop(struct tcpcb *, int);
int      tcp_dooptions(struct tcpcb *, u_char *, int, struct tcphdr *,
                struct mbuf *, int, struct tcp_opt_info *, u_int, uint64_t);
void     tcp_init(void);
int      tcp_input(struct mbuf **, int *, int, int, struct netstack *);
void     tcp_input_mlist(struct mbuf_list *, int);
int      tcp_mss(struct tcpcb *, int);
void     tcp_mss_update(struct tcpcb *);
void     tcp_softlro_glue(struct mbuf_list *, struct mbuf *, struct ifnet *);
u_int    tcp_hdrsz(struct tcpcb *);
void     tcp_mtudisc(struct inpcb *, int);
void     tcp_mtudisc_increase(struct inpcb *, int);
#ifdef INET6
void    tcp6_mtudisc_callback(struct sockaddr_in6 *, u_int);
#endif
struct tcpcb *
         tcp_newtcpcb(struct inpcb *, int);
void     tcp_notify(struct inpcb *, int);
int      tcp_output(struct tcpcb *);
int      tcp_softtso_chop(struct mbuf_list *, struct mbuf *, struct ifnet *,
            u_int);
int      tcp_if_output_tso(struct ifnet *, struct mbuf **, struct sockaddr *,
            struct rtentry *, uint32_t, u_int);
void     tcp_pulloutofband(struct socket *, u_int, struct mbuf *, int);
int      tcp_reass(struct tcpcb *, struct tcphdr *, struct mbuf *, int *);
void     tcp_rscale(struct tcpcb *, u_long);
void     tcp_respond(struct tcpcb *, caddr_t, struct tcphdr *, tcp_seq,
                tcp_seq, int, u_int, uint64_t);
void     tcp_setpersist(struct tcpcb *);
void     tcp_update_sndspace(struct tcpcb *);
void     tcp_update_rcvspace(struct tcpcb *);
void     tcp_slowtimo(void);
struct mbuf *
         tcp_template(struct tcpcb *);
#ifndef SMALL_KERNEL
void     tcp_trace(short, short, struct tcpcb *, struct tcpcb *, caddr_t,
                int, int);
#endif
struct tcpcb *
         tcp_usrclosed(struct tcpcb *);
int      tcp_sysctl(int *, u_int, void *, size_t *, void *, size_t);
int      tcp_attach(struct socket *, int, int);
int      tcp_detach(struct socket *);
int      tcp_bind(struct socket *, struct mbuf *, struct proc *);
int      tcp_listen(struct socket *);
int      tcp_connect(struct socket *, struct mbuf *);
int      tcp_accept(struct socket *, struct mbuf *);
int      tcp_disconnect(struct socket *);
int      tcp_shutdown(struct socket *);
void     tcp_rcvd(struct socket *);
int      tcp_send(struct socket *, struct mbuf *, struct mbuf *,
             struct mbuf *);
void     tcp_abort(struct socket *);
int      tcp_sockaddr(struct socket *, struct mbuf *);
int      tcp_peeraddr(struct socket *, struct mbuf *);
int      tcp_sense(struct socket *, struct stat *);
int      tcp_rcvoob(struct socket *, struct mbuf *, int);
int      tcp_sendoob(struct socket *, struct mbuf *, struct mbuf *,
             struct mbuf *);
void     tcp_xmit_timer(struct tcpcb *, int32_t);
void     tcp_sack_option(struct tcpcb *,struct tcphdr *,u_char *,int);
void     tcp_update_sack_list(struct tcpcb *tp, tcp_seq, tcp_seq);
void     tcp_del_sackholes(struct tcpcb *, struct tcphdr *);
void     tcp_clean_sackreport(struct tcpcb *tp);
void     tcp_sack_adjust(struct tcpcb *tp);
struct sackhole *
         tcp_sack_output(struct tcpcb *tp);
#ifdef DEBUG
void     tcp_print_holes(struct tcpcb *tp);
#endif
u_long   tcp_seq_subtract(u_long, u_long );
#ifdef TCP_SIGNATURE
int     tcp_signature_apply(caddr_t, caddr_t, unsigned int);
int     tcp_signature(struct tdb *, int, struct mbuf *, struct tcphdr *,
            int, int, char *);
#endif /* TCP_SIGNATURE */
void     tcp_set_iss_tsm(struct tcpcb *);

void     syn_cache_unreach(const struct sockaddr *, const struct sockaddr *,
           struct tcphdr *, u_int);
void     syn_cache_init(void);
void     syn_cache_cleanup(struct tcpcb *);

#ifdef SMALL_KERNEL
static inline void
tcp_trace(short act, short ostate, struct tcpcb *tp, struct tcpcb *otp,
    caddr_t headers, int req, int len)
{
}
#endif

#endif /* _KERNEL */
#endif /* _NETINET_TCP_VAR_H_ */