src/slirp/tcp_var.h

/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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
 * tcp_var.h,v 1.3 1994/08/21 05:27:39 paul Exp
 */

#ifndef _TCP_VAR_H_
#define _TCP_VAR_H_

#include "tcpip.h"
#include "tcp_timer.h"

#if SIZEOF_CHAR_P == 4
 typedef struct tcpiphdr *tcpiphdrp_32;
#else
 typedef u_int32_t tcpiphdrp_32;
#endif

/*
 * Tcp control block, one per tcp; fields:
 */
struct tcpcb {
        tcpiphdrp_32 seg_next;  /* sequencing queue */
        tcpiphdrp_32 seg_prev;
        short   t_state;                /* state of this connection */
        short   t_timer[TCPT_NTIMERS];  /* tcp timers */
        short   t_rxtshift;             /* log(2) of rexmt exp. backoff */
        short   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_short t_flags;
#define TF_ACKNOW       0x0001          /* ack peer immediately */
#define TF_DELACK       0x0002          /* ack, but try to delay it */
#define TF_NODELAY      0x0004          /* don't delay packets to coalesce */
#define TF_NOOPT        0x0008          /* don't use tcp options */
#define TF_SENTFIN      0x0010          /* have sent FIN */
#define TF_REQ_SCALE    0x0020          /* have/will request window scaling */
#define TF_RCVD_SCALE   0x0040          /* other side has requested scaling */
#define TF_REQ_TSTMP    0x0080          /* have/will request timestamps */
#define TF_RCVD_TSTMP   0x0100          /* a timestamp was received in SYN */
#define TF_SACK_PERMIT  0x0200          /* other side said I could SACK */

        /* Make it static  for now */
/*      struct  tcpiphdr *t_template;   / * skeletal packet for transmit */
        struct  tcpiphdr t_template;

        struct  socket *t_socket;               /* back pointer to socket */
/*
 * The following fields are used as in the protocol specification.
 * See RFC783, 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_int32_t snd_wnd;              /* send window */
/* receive sequence variables */
        u_int32_t rcv_wnd;              /* receive window */
        tcp_seq rcv_nxt;                /* receive next */
        tcp_seq rcv_up;                 /* receive urgent pointer */
        tcp_seq irs;                    /* initial receive sequence number */
/*
 * 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_int32_t snd_cwnd;             /* congestion-controlled window */
        u_int32_t snd_ssthresh;         /* snd_cwnd size threshold for
                                         * for slow start exponential to
                                         * linear switch
                                         */
/*
 * transmit timing stuff.  See below for scale of srtt and rttvar.
 * "Variance" is actually smoothed difference.
 */
        short   t_idle;                 /* inactivity time */
        short   t_rtt;                  /* round trip time */
        tcp_seq t_rtseq;                /* sequence number being timed */
        short   t_srtt;                 /* smoothed round-trip time */
        short   t_rttvar;               /* variance in round-trip time */
        u_short t_rttmin;               /* minimum rtt allowed */
        u_int32_t 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;
        u_int32_t       ts_recent;              /* timestamp echo data */
        u_int32_t       ts_recent_age;          /* when last updated */
        tcp_seq last_ack_sent;

};

#define sototcpcb(so)   ((so)->so_tcpcb)

/*
 * 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 3 bits to the right of the binary point,
 * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
 * binary point, and is smoothed with an ALPHA of 0.75.
 */
#define TCP_RTT_SCALE           8       /* multiplier for srtt; 3 bits frac. */
#define TCP_RTT_SHIFT           3       /* shift for srtt; 3 bits frac. */
#define TCP_RTTVAR_SCALE        4       /* multiplier for rttvar; 2 bits */
#define TCP_RTTVAR_SHIFT        2       /* multiplier for rttvar; 2 bits */

/*
 * 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 TCP_RTTVAR_SCALE
 * is the same as the multiplier for rttvar.
 */
#define TCP_REXMTVAL(tp) \
        (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar)

/* XXX
 * We want to avoid doing m_pullup on incoming packets but that
 * means avoiding dtom on the tcp reassembly code.  That in turn means
 * keeping an mbuf pointer in the reassembly queue (since we might
 * have a cluster).  As a quick hack, the source & destination
 * port numbers (which are no longer needed once we've located the
 * tcpcb) are overlayed with an mbuf pointer.
 */
#if SIZEOF_CHAR_P == 4
typedef struct mbuf *mbufp_32;
#else
typedef u_int32_t mbufp_32;
#endif
#define REASS_MBUF(ti) (*(mbufp_32 *)&((ti)->ti_t))

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

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

        u_long  tcps_rcvtotal;          /* total packets received */
        u_long  tcps_rcvpack;           /* packets received in sequence */
        u_long  tcps_rcvbyte;           /* bytes received in sequence */
        u_long  tcps_rcvbadsum;         /* packets received with ccksum errs */
        u_long  tcps_rcvbadoff;         /* packets received with bad offset */
/*      u_long  tcps_rcvshort;  */      /* packets received too short */
        u_long  tcps_rcvduppack;        /* duplicate-only packets received */
        u_long  tcps_rcvdupbyte;        /* duplicate-only bytes received */
        u_long  tcps_rcvpartduppack;    /* packets with some duplicate data */
        u_long  tcps_rcvpartdupbyte;    /* dup. bytes in part-dup. packets */
        u_long  tcps_rcvoopack;         /* out-of-order packets received */
        u_long  tcps_rcvoobyte;         /* out-of-order bytes received */
        u_long  tcps_rcvpackafterwin;   /* packets with data after window */
        u_long  tcps_rcvbyteafterwin;   /* bytes rcvd after window */
        u_long  tcps_rcvafterclose;     /* packets rcvd after "close" */
        u_long  tcps_rcvwinprobe;       /* rcvd window probe packets */
        u_long  tcps_rcvdupack;         /* rcvd duplicate acks */
        u_long  tcps_rcvacktoomuch;     /* rcvd acks for unsent data */
        u_long  tcps_rcvackpack;        /* rcvd ack packets */
        u_long  tcps_rcvackbyte;        /* bytes acked by rcvd acks */
        u_long  tcps_rcvwinupd;         /* rcvd window update packets */
/*      u_long  tcps_pawsdrop;  */      /* segments dropped due to PAWS */
        u_long  tcps_predack;           /* times hdr predict ok for acks */
        u_long  tcps_preddat;           /* times hdr predict ok for data pkts */
        u_long  tcps_socachemiss;       /* tcp_last_so misses */
        u_long  tcps_didnuttin;         /* Times tcp_output didn't do anything XXX */
};

extern struct   tcpstat tcpstat;        /* tcp statistics */
extern u_int32_t        tcp_now;                /* for RFC 1323 timestamps */

#endif
Revision:	1.1
Committed:	2005-05-13T09:00:59Z (19 years, 6 months ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
CVS Tags:	nigel-build-19, nigel-build-17
Log Message:	slirp user mode network emulation code from qemu
#	User	Rev	Content
1	gbeauche	1.1	/*
2			* Copyright (c) 1982, 1986, 1993, 1994
3			* The Regents of the University of California. All rights reserved.
4			*
5			* Redistribution and use in source and binary forms, with or without
6			* modification, are permitted provided that the following conditions
7			* are met:
8			* 1. Redistributions of source code must retain the above copyright
9			* notice, this list of conditions and the following disclaimer.
10			* 2. Redistributions in binary form must reproduce the above copyright
11			* notice, this list of conditions and the following disclaimer in the
12			* documentation and/or other materials provided with the distribution.
13			* 3. All advertising materials mentioning features or use of this software
14			* must display the following acknowledgement:
15			* This product includes software developed by the University of
16			* California, Berkeley and its contributors.
17			* 4. Neither the name of the University nor the names of its contributors
18			* may be used to endorse or promote products derived from this software
19			* without specific prior written permission.
20			*
21			* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22			* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24			* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25			* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26			* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27			* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29			* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30			* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31			* SUCH DAMAGE.
32			*
33			* @(#)tcp_var.h 8.3 (Berkeley) 4/10/94
34			* tcp_var.h,v 1.3 1994/08/21 05:27:39 paul Exp
35			*/
36
37			#ifndef _TCP_VAR_H_
38			#define _TCP_VAR_H_
39
40			#include "tcpip.h"
41			#include "tcp_timer.h"
42
43			#if SIZEOF_CHAR_P == 4
44			typedef struct tcpiphdr *tcpiphdrp_32;
45			#else
46			typedef u_int32_t tcpiphdrp_32;
47			#endif
48
49			/*
50			* Tcp control block, one per tcp; fields:
51			*/
52			struct tcpcb {
53			tcpiphdrp_32 seg_next; /* sequencing queue */
54			tcpiphdrp_32 seg_prev;
55			short t_state; /* state of this connection */
56			short t_timer[TCPT_NTIMERS]; /* tcp timers */
57			short t_rxtshift; /* log(2) of rexmt exp. backoff */
58			short t_rxtcur; /* current retransmit value */
59			short t_dupacks; /* consecutive dup acks recd */
60			u_short t_maxseg; /* maximum segment size */
61			char t_force; /* 1 if forcing out a byte */
62			u_short t_flags;
63			#define TF_ACKNOW 0x0001 /* ack peer immediately */
64			#define TF_DELACK 0x0002 /* ack, but try to delay it */
65			#define TF_NODELAY 0x0004 /* don't delay packets to coalesce */
66			#define TF_NOOPT 0x0008 /* don't use tcp options */
67			#define TF_SENTFIN 0x0010 /* have sent FIN */
68			#define TF_REQ_SCALE 0x0020 /* have/will request window scaling */
69			#define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */
70			#define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */
71			#define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */
72			#define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */
73
74			/* Make it static for now */
75			/* struct tcpiphdr t_template; / skeletal packet for transmit */
76			struct tcpiphdr t_template;
77
78			struct socket t_socket; / back pointer to socket */
79			/*
80			* The following fields are used as in the protocol specification.
81			* See RFC783, Dec. 1981, page 21.
82			*/
83			/* send sequence variables */
84			tcp_seq snd_una; /* send unacknowledged */
85			tcp_seq snd_nxt; /* send next */
86			tcp_seq snd_up; /* send urgent pointer */
87			tcp_seq snd_wl1; /* window update seg seq number */
88			tcp_seq snd_wl2; /* window update seg ack number */
89			tcp_seq iss; /* initial send sequence number */
90			u_int32_t snd_wnd; /* send window */
91			/* receive sequence variables */
92			u_int32_t rcv_wnd; /* receive window */
93			tcp_seq rcv_nxt; /* receive next */
94			tcp_seq rcv_up; /* receive urgent pointer */
95			tcp_seq irs; /* initial receive sequence number */
96			/*
97			* Additional variables for this implementation.
98			*/
99			/* receive variables */
100			tcp_seq rcv_adv; /* advertised window */
101			/* retransmit variables */
102			tcp_seq snd_max; /* highest sequence number sent;
103			* used to recognize retransmits
104			*/
105			/* congestion control (for slow start, source quench, retransmit after loss) */
106			u_int32_t snd_cwnd; /* congestion-controlled window */
107			u_int32_t snd_ssthresh; /* snd_cwnd size threshold for
108			* for slow start exponential to
109			* linear switch
110			*/
111			/*
112			* transmit timing stuff. See below for scale of srtt and rttvar.
113			* "Variance" is actually smoothed difference.
114			*/
115			short t_idle; /* inactivity time */
116			short t_rtt; /* round trip time */
117			tcp_seq t_rtseq; /* sequence number being timed */
118			short t_srtt; /* smoothed round-trip time */
119			short t_rttvar; /* variance in round-trip time */
120			u_short t_rttmin; /* minimum rtt allowed */
121			u_int32_t max_sndwnd; /* largest window peer has offered */
122
123			/* out-of-band data */
124			char t_oobflags; /* have some */
125			char t_iobc; /* input character */
126			#define TCPOOB_HAVEDATA 0x01
127			#define TCPOOB_HADDATA 0x02
128			short t_softerror; /* possible error not yet reported */
129
130			/* RFC 1323 variables */
131			u_char snd_scale; /* window scaling for send window */
132			u_char rcv_scale; /* window scaling for recv window */
133			u_char request_r_scale; /* pending window scaling */
134			u_char requested_s_scale;
135			u_int32_t ts_recent; /* timestamp echo data */
136			u_int32_t ts_recent_age; /* when last updated */
137			tcp_seq last_ack_sent;
138
139			};
140
141			#define sototcpcb(so) ((so)->so_tcpcb)
142
143			/*
144			* The smoothed round-trip time and estimated variance
145			* are stored as fixed point numbers scaled by the values below.
146			* For convenience, these scales are also used in smoothing the average
147			* (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
148			* With these scales, srtt has 3 bits to the right of the binary point,
149			* and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
150			* binary point, and is smoothed with an ALPHA of 0.75.
151			*/
152			#define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */
153			#define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
154			#define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */
155			#define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */
156
157			/*
158			* The initial retransmission should happen at rtt + 4 * rttvar.
159			* Because of the way we do the smoothing, srtt and rttvar
160			* will each average +1/2 tick of bias. When we compute
161			* the retransmit timer, we want 1/2 tick of rounding and
162			* 1 extra tick because of +-1/2 tick uncertainty in the
163			* firing of the timer. The bias will give us exactly the
164			* 1.5 tick we need. But, because the bias is
165			* statistical, we have to test that we don't drop below
166			* the minimum feasible timer (which is 2 ticks).
167			* This macro assumes that the value of TCP_RTTVAR_SCALE
168			* is the same as the multiplier for rttvar.
169			*/
170			#define TCP_REXMTVAL(tp) \
171			(((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar)
172
173			/* XXX
174			* We want to avoid doing m_pullup on incoming packets but that
175			* means avoiding dtom on the tcp reassembly code. That in turn means
176			* keeping an mbuf pointer in the reassembly queue (since we might
177			* have a cluster). As a quick hack, the source & destination
178			* port numbers (which are no longer needed once we've located the
179			* tcpcb) are overlayed with an mbuf pointer.
180			*/
181			#if SIZEOF_CHAR_P == 4
182			typedef struct mbuf *mbufp_32;
183			#else
184			typedef u_int32_t mbufp_32;
185			#endif
186			#define REASS_MBUF(ti) ((mbufp_32 )&((ti)->ti_t))
187
188			/*
189			* TCP statistics.
190			* Many of these should be kept per connection,
191			* but that's inconvenient at the moment.
192			*/
193			struct tcpstat {
194			u_long tcps_connattempt; /* connections initiated */
195			u_long tcps_accepts; /* connections accepted */
196			u_long tcps_connects; /* connections established */
197			u_long tcps_drops; /* connections dropped */
198			u_long tcps_conndrops; /* embryonic connections dropped */
199			u_long tcps_closed; /* conn. closed (includes drops) */
200			u_long tcps_segstimed; /* segs where we tried to get rtt */
201			u_long tcps_rttupdated; /* times we succeeded */
202			u_long tcps_delack; /* delayed acks sent */
203			u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
204			u_long tcps_rexmttimeo; /* retransmit timeouts */
205			u_long tcps_persisttimeo; /* persist timeouts */
206			u_long tcps_keeptimeo; /* keepalive timeouts */
207			u_long tcps_keepprobe; /* keepalive probes sent */
208			u_long tcps_keepdrops; /* connections dropped in keepalive */
209
210			u_long tcps_sndtotal; /* total packets sent */
211			u_long tcps_sndpack; /* data packets sent */
212			u_long tcps_sndbyte; /* data bytes sent */
213			u_long tcps_sndrexmitpack; /* data packets retransmitted */
214			u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
215			u_long tcps_sndacks; /* ack-only packets sent */
216			u_long tcps_sndprobe; /* window probes sent */
217			u_long tcps_sndurg; /* packets sent with URG only */
218			u_long tcps_sndwinup; /* window update-only packets sent */
219			u_long tcps_sndctrl; /* control (SYN\|FIN\|RST) packets sent */
220
221			u_long tcps_rcvtotal; /* total packets received */
222			u_long tcps_rcvpack; /* packets received in sequence */
223			u_long tcps_rcvbyte; /* bytes received in sequence */
224			u_long tcps_rcvbadsum; /* packets received with ccksum errs */
225			u_long tcps_rcvbadoff; /* packets received with bad offset */
226			/* u_long tcps_rcvshort; / / packets received too short */
227			u_long tcps_rcvduppack; /* duplicate-only packets received */
228			u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
229			u_long tcps_rcvpartduppack; /* packets with some duplicate data */
230			u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
231			u_long tcps_rcvoopack; /* out-of-order packets received */
232			u_long tcps_rcvoobyte; /* out-of-order bytes received */
233			u_long tcps_rcvpackafterwin; /* packets with data after window */
234			u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
235			u_long tcps_rcvafterclose; /* packets rcvd after "close" */
236			u_long tcps_rcvwinprobe; /* rcvd window probe packets */
237			u_long tcps_rcvdupack; /* rcvd duplicate acks */
238			u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
239			u_long tcps_rcvackpack; /* rcvd ack packets */
240			u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
241			u_long tcps_rcvwinupd; /* rcvd window update packets */
242			/* u_long tcps_pawsdrop; / / segments dropped due to PAWS */
243			u_long tcps_predack; /* times hdr predict ok for acks */
244			u_long tcps_preddat; /* times hdr predict ok for data pkts */
245			u_long tcps_socachemiss; /* tcp_last_so misses */
246			u_long tcps_didnuttin; /* Times tcp_output didn't do anything XXX */
247			};
248
249			extern struct tcpstat tcpstat; /* tcp statistics */
250			extern u_int32_t tcp_now; /* for RFC 1323 timestamps */
251
252			#endif