xref: /freebsd/sys/netinet/tcp_var.h (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
1 /*-
2  * Copyright (c) 1982, 1986, 1993, 1994, 1995
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)tcp_var.h	8.4 (Berkeley) 5/24/95
30  * $FreeBSD$
31  */
32 
33 #ifndef _NETINET_TCP_VAR_H_
34 #define _NETINET_TCP_VAR_H_
35 
36 #include <netinet/tcp.h>
37 
38 #ifdef _KERNEL
39 #include <net/vnet.h>
40 
41 /*
42  * Kernel variables for tcp.
43  */
44 VNET_DECLARE(int, tcp_do_rfc1323);
45 #define	V_tcp_do_rfc1323	VNET(tcp_do_rfc1323)
46 
47 #endif /* _KERNEL */
48 
49 /* TCP segment queue entry */
50 struct tseg_qent {
51 	LIST_ENTRY(tseg_qent) tqe_q;
52 	int	tqe_len;		/* TCP segment data length */
53 	struct	tcphdr *tqe_th;		/* a pointer to tcp header */
54 	struct	mbuf	*tqe_m;		/* mbuf contains packet */
55 };
56 LIST_HEAD(tsegqe_head, tseg_qent);
57 
58 struct sackblk {
59 	tcp_seq start;		/* start seq no. of sack block */
60 	tcp_seq end;		/* end seq no. */
61 };
62 
63 struct sackhole {
64 	tcp_seq start;		/* start seq no. of hole */
65 	tcp_seq end;		/* end seq no. */
66 	tcp_seq rxmit;		/* next seq. no in hole to be retransmitted */
67 	TAILQ_ENTRY(sackhole) scblink;	/* scoreboard linkage */
68 };
69 
70 struct sackhint {
71 	struct sackhole	*nexthole;
72 	int		sack_bytes_rexmit;
73 	tcp_seq		last_sack_ack;	/* Most recent/largest sacked ack */
74 
75 	int		ispare;		/* explicit pad for 64bit alignment */
76 	uint64_t	_pad[2];	/* 1 sacked_bytes, 1 TBD */
77 };
78 
79 struct tcptemp {
80 	u_char	tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
81 	struct	tcphdr tt_t;
82 };
83 
84 #define tcp6cb		tcpcb  /* for KAME src sync over BSD*'s */
85 
86 /*
87  * Tcp control block, one per tcp; fields:
88  * Organized for 16 byte cacheline efficiency.
89  */
90 struct tcpcb {
91 	struct	tsegqe_head t_segq;	/* segment reassembly queue */
92 	void	*t_pspare[2];		/* new reassembly queue */
93 	int	t_segqlen;		/* segment reassembly queue length */
94 	int	t_dupacks;		/* consecutive dup acks recd */
95 
96 	struct tcp_timer *t_timers;	/* All the TCP timers in one struct */
97 
98 	struct	inpcb *t_inpcb;		/* back pointer to internet pcb */
99 	int	t_state;		/* state of this connection */
100 	u_int	t_flags;
101 
102 	struct	vnet *t_vnet;		/* back pointer to parent vnet */
103 
104 	tcp_seq	snd_una;		/* sent but unacknowledged */
105 	tcp_seq	snd_max;		/* highest sequence number sent;
106 					 * used to recognize retransmits
107 					 */
108 	tcp_seq	snd_nxt;		/* send next */
109 	tcp_seq	snd_up;			/* send urgent pointer */
110 
111 	tcp_seq	snd_wl1;		/* window update seg seq number */
112 	tcp_seq	snd_wl2;		/* window update seg ack number */
113 	tcp_seq	iss;			/* initial send sequence number */
114 	tcp_seq	irs;			/* initial receive sequence number */
115 
116 	tcp_seq	rcv_nxt;		/* receive next */
117 	tcp_seq	rcv_adv;		/* advertised window */
118 	u_long	rcv_wnd;		/* receive window */
119 	tcp_seq	rcv_up;			/* receive urgent pointer */
120 
121 	u_long	snd_wnd;		/* send window */
122 	u_long	snd_cwnd;		/* congestion-controlled window */
123 	u_long	snd_spare1;		/* unused */
124 	u_long	snd_ssthresh;		/* snd_cwnd size threshold for
125 					 * for slow start exponential to
126 					 * linear switch
127 					 */
128 	u_long	snd_spare2;		/* unused */
129 	tcp_seq	snd_recover;		/* for use in NewReno Fast Recovery */
130 
131 	u_int	t_maxopd;		/* mss plus options */
132 
133 	u_int	t_rcvtime;		/* inactivity time */
134 	u_int	t_starttime;		/* time connection was established */
135 	u_int	t_rtttime;		/* RTT measurement start time */
136 	tcp_seq	t_rtseq;		/* sequence number being timed */
137 
138 	u_int	t_bw_spare1;		/* unused */
139 	tcp_seq	t_bw_spare2;		/* unused */
140 
141 	int	t_rxtcur;		/* current retransmit value (ticks) */
142 	u_int	t_maxseg;		/* maximum segment size */
143 	int	t_srtt;			/* smoothed round-trip time */
144 	int	t_rttvar;		/* variance in round-trip time */
145 
146 	int	t_rxtshift;		/* log(2) of rexmt exp. backoff */
147 	u_int	t_rttmin;		/* minimum rtt allowed */
148 	u_int	t_rttbest;		/* best rtt we've seen */
149 	u_long	t_rttupdated;		/* number of times rtt sampled */
150 	u_long	max_sndwnd;		/* largest window peer has offered */
151 
152 	int	t_softerror;		/* possible error not yet reported */
153 /* out-of-band data */
154 	char	t_oobflags;		/* have some */
155 	char	t_iobc;			/* input character */
156 /* RFC 1323 variables */
157 	u_char	snd_scale;		/* window scaling for send window */
158 	u_char	rcv_scale;		/* window scaling for recv window */
159 	u_char	request_r_scale;	/* pending window scaling */
160 	u_int32_t  ts_recent;		/* timestamp echo data */
161 	u_int	ts_recent_age;		/* when last updated */
162 	u_int32_t  ts_offset;		/* our timestamp offset */
163 
164 	tcp_seq	last_ack_sent;
165 /* experimental */
166 	u_long	snd_cwnd_prev;		/* cwnd prior to retransmit */
167 	u_long	snd_ssthresh_prev;	/* ssthresh prior to retransmit */
168 	tcp_seq	snd_recover_prev;	/* snd_recover prior to retransmit */
169 	int	t_sndzerowin;		/* zero-window updates sent */
170 	u_int	t_badrxtwin;		/* window for retransmit recovery */
171 	u_char	snd_limited;		/* segments limited transmitted */
172 /* SACK related state */
173 	int	snd_numholes;		/* number of holes seen by sender */
174 	TAILQ_HEAD(sackhole_head, sackhole) snd_holes;
175 					/* SACK scoreboard (sorted) */
176 	tcp_seq	snd_fack;		/* last seq number(+1) sack'd by rcv'r*/
177 	int	rcv_numsacks;		/* # distinct sack blks present */
178 	struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
179 	tcp_seq sack_newdata;		/* New data xmitted in this recovery
180 					   episode starts at this seq number */
181 	struct sackhint	sackhint;	/* SACK scoreboard hint */
182 	int	t_rttlow;		/* smallest observerved RTT */
183 	u_int32_t	rfbuf_ts;	/* recv buffer autoscaling timestamp */
184 	int	rfbuf_cnt;		/* recv buffer autoscaling byte count */
185 	struct toedev	*tod;		/* toedev handling this connection */
186 	int	t_sndrexmitpack;	/* retransmit packets sent */
187 	int	t_rcvoopack;		/* out-of-order packets received */
188 	void	*t_toe;			/* TOE pcb pointer */
189 	int	t_bytes_acked;		/* # bytes acked during current RTT */
190 	struct cc_algo	*cc_algo;	/* congestion control algorithm */
191 	struct cc_var	*ccv;		/* congestion control specific vars */
192 	struct osd	*osd;		/* storage for Khelp module data */
193 
194 	u_int	t_keepinit;		/* time to establish connection */
195 	u_int	t_keepidle;		/* time before keepalive probes begin */
196 	u_int	t_keepintvl;		/* interval between keepalives */
197 	u_int	t_keepcnt;		/* number of keepalives before close */
198 
199 	u_int	t_tsomax;		/* TSO total burst length limit in bytes */
200 	u_int	t_tsomaxsegcount;	/* TSO maximum segment count */
201 	u_int	t_tsomaxsegsize;	/* TSO maximum segment size in bytes */
202 	u_int	t_pmtud_saved_maxopd;	/* pre-blackhole MSS */
203 	u_int	t_flags2;		/* More tcpcb flags storage */
204 
205 	uint32_t t_ispare[8];		/* 5 UTO, 3 TBD */
206 	void	*t_pspare2[4];		/* 1 TCP_SIGNATURE, 3 TBD */
207 	uint64_t _pad[6];		/* 6 TBD (1-2 CC/RTT?) */
208 };
209 
210 /*
211  * Flags and utility macros for the t_flags field.
212  */
213 #define	TF_ACKNOW	0x000001	/* ack peer immediately */
214 #define	TF_DELACK	0x000002	/* ack, but try to delay it */
215 #define	TF_NODELAY	0x000004	/* don't delay packets to coalesce */
216 #define	TF_NOOPT	0x000008	/* don't use tcp options */
217 #define	TF_SENTFIN	0x000010	/* have sent FIN */
218 #define	TF_REQ_SCALE	0x000020	/* have/will request window scaling */
219 #define	TF_RCVD_SCALE	0x000040	/* other side has requested scaling */
220 #define	TF_REQ_TSTMP	0x000080	/* have/will request timestamps */
221 #define	TF_RCVD_TSTMP	0x000100	/* a timestamp was received in SYN */
222 #define	TF_SACK_PERMIT	0x000200	/* other side said I could SACK */
223 #define	TF_NEEDSYN	0x000400	/* send SYN (implicit state) */
224 #define	TF_NEEDFIN	0x000800	/* send FIN (implicit state) */
225 #define	TF_NOPUSH	0x001000	/* don't push */
226 #define	TF_PREVVALID	0x002000	/* saved values for bad rxmit valid */
227 #define	TF_MORETOCOME	0x010000	/* More data to be appended to sock */
228 #define	TF_LQ_OVERFLOW	0x020000	/* listen queue overflow */
229 #define	TF_LASTIDLE	0x040000	/* connection was previously idle */
230 #define	TF_RXWIN0SENT	0x080000	/* sent a receiver win 0 in response */
231 #define	TF_FASTRECOVERY	0x100000	/* in NewReno Fast Recovery */
232 #define	TF_WASFRECOVERY	0x200000	/* was in NewReno Fast Recovery */
233 #define	TF_SIGNATURE	0x400000	/* require MD5 digests (RFC2385) */
234 #define	TF_FORCEDATA	0x800000	/* force out a byte */
235 #define	TF_TSO		0x1000000	/* TSO enabled on this connection */
236 #define	TF_TOE		0x2000000	/* this connection is offloaded */
237 #define	TF_ECN_PERMIT	0x4000000	/* connection ECN-ready */
238 #define	TF_ECN_SND_CWR	0x8000000	/* ECN CWR in queue */
239 #define	TF_ECN_SND_ECE	0x10000000	/* ECN ECE in queue */
240 #define	TF_CONGRECOVERY	0x20000000	/* congestion recovery mode */
241 #define	TF_WASCRECOVERY	0x40000000	/* was in congestion recovery */
242 
243 #define	IN_FASTRECOVERY(t_flags)	(t_flags & TF_FASTRECOVERY)
244 #define	ENTER_FASTRECOVERY(t_flags)	t_flags |= TF_FASTRECOVERY
245 #define	EXIT_FASTRECOVERY(t_flags)	t_flags &= ~TF_FASTRECOVERY
246 
247 #define	IN_CONGRECOVERY(t_flags)	(t_flags & TF_CONGRECOVERY)
248 #define	ENTER_CONGRECOVERY(t_flags)	t_flags |= TF_CONGRECOVERY
249 #define	EXIT_CONGRECOVERY(t_flags)	t_flags &= ~TF_CONGRECOVERY
250 
251 #define	IN_RECOVERY(t_flags) (t_flags & (TF_CONGRECOVERY | TF_FASTRECOVERY))
252 #define	ENTER_RECOVERY(t_flags) t_flags |= (TF_CONGRECOVERY | TF_FASTRECOVERY)
253 #define	EXIT_RECOVERY(t_flags) t_flags &= ~(TF_CONGRECOVERY | TF_FASTRECOVERY)
254 
255 #define	BYTES_THIS_ACK(tp, th)	(th->th_ack - tp->snd_una)
256 
257 /*
258  * Flags for the t_oobflags field.
259  */
260 #define	TCPOOB_HAVEDATA	0x01
261 #define	TCPOOB_HADDATA	0x02
262 
263 #ifdef TCP_SIGNATURE
264 /*
265  * Defines which are needed by the xform_tcp module and tcp_[in|out]put
266  * for SADB verification and lookup.
267  */
268 #define	TCP_SIGLEN	16	/* length of computed digest in bytes */
269 #define	TCP_KEYLEN_MIN	1	/* minimum length of TCP-MD5 key */
270 #define	TCP_KEYLEN_MAX	80	/* maximum length of TCP-MD5 key */
271 /*
272  * Only a single SA per host may be specified at this time. An SPI is
273  * needed in order for the KEY_ALLOCSA() lookup to work.
274  */
275 #define	TCP_SIG_SPI	0x1000
276 #endif /* TCP_SIGNATURE */
277 
278 /*
279  * Flags for PLPMTU handling, t_flags2
280  */
281 #define	TF2_PLPMTU_BLACKHOLE	0x00000001 /* Possible PLPMTUD Black Hole. */
282 #define	TF2_PLPMTU_PMTUD	0x00000002 /* Allowed to attempt PLPMTUD. */
283 #define	TF2_PLPMTU_MAXSEGSNT	0x00000004 /* Last seg sent was full seg. */
284 
285 /*
286  * Structure to hold TCP options that are only used during segment
287  * processing (in tcp_input), but not held in the tcpcb.
288  * It's basically used to reduce the number of parameters
289  * to tcp_dooptions and tcp_addoptions.
290  * The binary order of the to_flags is relevant for packing of the
291  * options in tcp_addoptions.
292  */
293 struct tcpopt {
294 	u_int64_t	to_flags;	/* which options are present */
295 #define	TOF_MSS		0x0001		/* maximum segment size */
296 #define	TOF_SCALE	0x0002		/* window scaling */
297 #define	TOF_SACKPERM	0x0004		/* SACK permitted */
298 #define	TOF_TS		0x0010		/* timestamp */
299 #define	TOF_SIGNATURE	0x0040		/* TCP-MD5 signature option (RFC2385) */
300 #define	TOF_SACK	0x0080		/* Peer sent SACK option */
301 #define	TOF_MAXOPT	0x0100
302 	u_int32_t	to_tsval;	/* new timestamp */
303 	u_int32_t	to_tsecr;	/* reflected timestamp */
304 	u_char		*to_sacks;	/* pointer to the first SACK blocks */
305 	u_char		*to_signature;	/* pointer to the TCP-MD5 signature */
306 	u_int16_t	to_mss;		/* maximum segment size */
307 	u_int8_t	to_wscale;	/* window scaling */
308 	u_int8_t	to_nsacks;	/* number of SACK blocks */
309 	u_int32_t	to_spare;	/* UTO */
310 };
311 
312 /*
313  * Flags for tcp_dooptions.
314  */
315 #define	TO_SYN		0x01		/* parse SYN-only options */
316 
317 struct hc_metrics_lite {	/* must stay in sync with hc_metrics */
318 	u_long	rmx_mtu;	/* MTU for this path */
319 	u_long	rmx_ssthresh;	/* outbound gateway buffer limit */
320 	u_long	rmx_rtt;	/* estimated round trip time */
321 	u_long	rmx_rttvar;	/* estimated rtt variance */
322 	u_long	rmx_bandwidth;	/* estimated bandwidth */
323 	u_long	rmx_cwnd;	/* congestion window */
324 	u_long	rmx_sendpipe;   /* outbound delay-bandwidth product */
325 	u_long	rmx_recvpipe;   /* inbound delay-bandwidth product */
326 };
327 
328 /*
329  * Used by tcp_maxmtu() to communicate interface specific features
330  * and limits at the time of connection setup.
331  */
332 struct tcp_ifcap {
333 	int	ifcap;
334 	u_int	tsomax;
335 	u_int	tsomaxsegcount;
336 	u_int	tsomaxsegsize;
337 };
338 
339 #ifndef _NETINET_IN_PCB_H_
340 struct in_conninfo;
341 #endif /* _NETINET_IN_PCB_H_ */
342 
343 struct tcptw {
344 	struct inpcb	*tw_inpcb;	/* XXX back pointer to internet pcb */
345 	tcp_seq		snd_nxt;
346 	tcp_seq		rcv_nxt;
347 	tcp_seq		iss;
348 	tcp_seq		irs;
349 	u_short		last_win;	/* cached window value */
350 	u_short		tw_so_options;	/* copy of so_options */
351 	struct ucred	*tw_cred;	/* user credentials */
352 	u_int32_t	t_recent;
353 	u_int32_t	ts_offset;	/* our timestamp offset */
354 	u_int		t_starttime;
355 	int		tw_time;
356 	TAILQ_ENTRY(tcptw) tw_2msl;
357 	void		*tw_pspare;	/* TCP_SIGNATURE */
358 	u_int		*tw_spare;	/* TCP_SIGNATURE */
359 };
360 
361 #define	intotcpcb(ip)	((struct tcpcb *)(ip)->inp_ppcb)
362 #define	intotw(ip)	((struct tcptw *)(ip)->inp_ppcb)
363 #define	sototcpcb(so)	(intotcpcb(sotoinpcb(so)))
364 
365 /*
366  * The smoothed round-trip time and estimated variance
367  * are stored as fixed point numbers scaled by the values below.
368  * For convenience, these scales are also used in smoothing the average
369  * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
370  * With these scales, srtt has 3 bits to the right of the binary point,
371  * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
372  * binary point, and is smoothed with an ALPHA of 0.75.
373  */
374 #define	TCP_RTT_SCALE		32	/* multiplier for srtt; 3 bits frac. */
375 #define	TCP_RTT_SHIFT		5	/* shift for srtt; 3 bits frac. */
376 #define	TCP_RTTVAR_SCALE	16	/* multiplier for rttvar; 2 bits */
377 #define	TCP_RTTVAR_SHIFT	4	/* shift for rttvar; 2 bits */
378 #define	TCP_DELTA_SHIFT		2	/* see tcp_input.c */
379 
380 /*
381  * The initial retransmission should happen at rtt + 4 * rttvar.
382  * Because of the way we do the smoothing, srtt and rttvar
383  * will each average +1/2 tick of bias.  When we compute
384  * the retransmit timer, we want 1/2 tick of rounding and
385  * 1 extra tick because of +-1/2 tick uncertainty in the
386  * firing of the timer.  The bias will give us exactly the
387  * 1.5 tick we need.  But, because the bias is
388  * statistical, we have to test that we don't drop below
389  * the minimum feasible timer (which is 2 ticks).
390  * This version of the macro adapted from a paper by Lawrence
391  * Brakmo and Larry Peterson which outlines a problem caused
392  * by insufficient precision in the original implementation,
393  * which results in inappropriately large RTO values for very
394  * fast networks.
395  */
396 #define	TCP_REXMTVAL(tp) \
397 	max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
398 	  + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
399 
400 /*
401  * TCP statistics.
402  * Many of these should be kept per connection,
403  * but that's inconvenient at the moment.
404  */
405 struct	tcpstat {
406 	uint64_t tcps_connattempt;	/* connections initiated */
407 	uint64_t tcps_accepts;		/* connections accepted */
408 	uint64_t tcps_connects;		/* connections established */
409 	uint64_t tcps_drops;		/* connections dropped */
410 	uint64_t tcps_conndrops;	/* embryonic connections dropped */
411 	uint64_t tcps_minmssdrops;	/* average minmss too low drops */
412 	uint64_t tcps_closed;		/* conn. closed (includes drops) */
413 	uint64_t tcps_segstimed;	/* segs where we tried to get rtt */
414 	uint64_t tcps_rttupdated;	/* times we succeeded */
415 	uint64_t tcps_delack;		/* delayed acks sent */
416 	uint64_t tcps_timeoutdrop;	/* conn. dropped in rxmt timeout */
417 	uint64_t tcps_rexmttimeo;	/* retransmit timeouts */
418 	uint64_t tcps_persisttimeo;	/* persist timeouts */
419 	uint64_t tcps_keeptimeo;	/* keepalive timeouts */
420 	uint64_t tcps_keepprobe;	/* keepalive probes sent */
421 	uint64_t tcps_keepdrops;	/* connections dropped in keepalive */
422 
423 	uint64_t tcps_sndtotal;		/* total packets sent */
424 	uint64_t tcps_sndpack;		/* data packets sent */
425 	uint64_t tcps_sndbyte;		/* data bytes sent */
426 	uint64_t tcps_sndrexmitpack;	/* data packets retransmitted */
427 	uint64_t tcps_sndrexmitbyte;	/* data bytes retransmitted */
428 	uint64_t tcps_sndrexmitbad;	/* unnecessary packet retransmissions */
429 	uint64_t tcps_sndacks;		/* ack-only packets sent */
430 	uint64_t tcps_sndprobe;		/* window probes sent */
431 	uint64_t tcps_sndurg;		/* packets sent with URG only */
432 	uint64_t tcps_sndwinup;		/* window update-only packets sent */
433 	uint64_t tcps_sndctrl;		/* control (SYN|FIN|RST) packets sent */
434 
435 	uint64_t tcps_rcvtotal;		/* total packets received */
436 	uint64_t tcps_rcvpack;		/* packets received in sequence */
437 	uint64_t tcps_rcvbyte;		/* bytes received in sequence */
438 	uint64_t tcps_rcvbadsum;	/* packets received with ccksum errs */
439 	uint64_t tcps_rcvbadoff;	/* packets received with bad offset */
440 	uint64_t tcps_rcvreassfull;	/* packets dropped for no reass space */
441 	uint64_t tcps_rcvshort;		/* packets received too short */
442 	uint64_t tcps_rcvduppack;	/* duplicate-only packets received */
443 	uint64_t tcps_rcvdupbyte;	/* duplicate-only bytes received */
444 	uint64_t tcps_rcvpartduppack;	/* packets with some duplicate data */
445 	uint64_t tcps_rcvpartdupbyte;	/* dup. bytes in part-dup. packets */
446 	uint64_t tcps_rcvoopack;	/* out-of-order packets received */
447 	uint64_t tcps_rcvoobyte;	/* out-of-order bytes received */
448 	uint64_t tcps_rcvpackafterwin;	/* packets with data after window */
449 	uint64_t tcps_rcvbyteafterwin;	/* bytes rcvd after window */
450 	uint64_t tcps_rcvafterclose;	/* packets rcvd after "close" */
451 	uint64_t tcps_rcvwinprobe;	/* rcvd window probe packets */
452 	uint64_t tcps_rcvdupack;	/* rcvd duplicate acks */
453 	uint64_t tcps_rcvacktoomuch;	/* rcvd acks for unsent data */
454 	uint64_t tcps_rcvackpack;	/* rcvd ack packets */
455 	uint64_t tcps_rcvackbyte;	/* bytes acked by rcvd acks */
456 	uint64_t tcps_rcvwinupd;	/* rcvd window update packets */
457 	uint64_t tcps_pawsdrop;		/* segments dropped due to PAWS */
458 	uint64_t tcps_predack;		/* times hdr predict ok for acks */
459 	uint64_t tcps_preddat;		/* times hdr predict ok for data pkts */
460 	uint64_t tcps_pcbcachemiss;
461 	uint64_t tcps_cachedrtt;	/* times cached RTT in route updated */
462 	uint64_t tcps_cachedrttvar;	/* times cached rttvar updated */
463 	uint64_t tcps_cachedssthresh;	/* times cached ssthresh updated */
464 	uint64_t tcps_usedrtt;		/* times RTT initialized from route */
465 	uint64_t tcps_usedrttvar;	/* times RTTVAR initialized from rt */
466 	uint64_t tcps_usedssthresh;	/* times ssthresh initialized from rt*/
467 	uint64_t tcps_persistdrop;	/* timeout in persist state */
468 	uint64_t tcps_badsyn;		/* bogus SYN, e.g. premature ACK */
469 	uint64_t tcps_mturesent;	/* resends due to MTU discovery */
470 	uint64_t tcps_listendrop;	/* listen queue overflows */
471 	uint64_t tcps_badrst;		/* ignored RSTs in the window */
472 
473 	uint64_t tcps_sc_added;		/* entry added to syncache */
474 	uint64_t tcps_sc_retransmitted;	/* syncache entry was retransmitted */
475 	uint64_t tcps_sc_dupsyn;	/* duplicate SYN packet */
476 	uint64_t tcps_sc_dropped;	/* could not reply to packet */
477 	uint64_t tcps_sc_completed;	/* successful extraction of entry */
478 	uint64_t tcps_sc_bucketoverflow;/* syncache per-bucket limit hit */
479 	uint64_t tcps_sc_cacheoverflow;	/* syncache cache limit hit */
480 	uint64_t tcps_sc_reset;		/* RST removed entry from syncache */
481 	uint64_t tcps_sc_stale;		/* timed out or listen socket gone */
482 	uint64_t tcps_sc_aborted;	/* syncache entry aborted */
483 	uint64_t tcps_sc_badack;	/* removed due to bad ACK */
484 	uint64_t tcps_sc_unreach;	/* ICMP unreachable received */
485 	uint64_t tcps_sc_zonefail;	/* zalloc() failed */
486 	uint64_t tcps_sc_sendcookie;	/* SYN cookie sent */
487 	uint64_t tcps_sc_recvcookie;	/* SYN cookie received */
488 
489 	uint64_t tcps_hc_added;		/* entry added to hostcache */
490 	uint64_t tcps_hc_bucketoverflow;/* hostcache per bucket limit hit */
491 
492 	uint64_t tcps_finwait2_drops;    /* Drop FIN_WAIT_2 connection after time limit */
493 
494 	/* SACK related stats */
495 	uint64_t tcps_sack_recovery_episode; /* SACK recovery episodes */
496 	uint64_t tcps_sack_rexmits;	    /* SACK rexmit segments   */
497 	uint64_t tcps_sack_rexmit_bytes;    /* SACK rexmit bytes      */
498 	uint64_t tcps_sack_rcv_blocks;	    /* SACK blocks (options) received */
499 	uint64_t tcps_sack_send_blocks;	    /* SACK blocks (options) sent     */
500 	uint64_t tcps_sack_sboverflow;	    /* times scoreboard overflowed */
501 
502 	/* ECN related stats */
503 	uint64_t tcps_ecn_ce;		/* ECN Congestion Experienced */
504 	uint64_t tcps_ecn_ect0;		/* ECN Capable Transport */
505 	uint64_t tcps_ecn_ect1;		/* ECN Capable Transport */
506 	uint64_t tcps_ecn_shs;		/* ECN successful handshakes */
507 	uint64_t tcps_ecn_rcwnd;	/* # times ECN reduced the cwnd */
508 
509 	/* TCP_SIGNATURE related stats */
510 	uint64_t tcps_sig_rcvgoodsig;	/* Total matching signature received */
511 	uint64_t tcps_sig_rcvbadsig;	/* Total bad signature received */
512 	uint64_t tcps_sig_err_buildsig;	/* Mismatching signature received */
513 	uint64_t tcps_sig_err_sigopt;	/* No signature expected by socket */
514 	uint64_t tcps_sig_err_nosigopt;	/* No signature provided by segment */
515 
516 	uint64_t _pad[12];		/* 6 UTO, 6 TBD */
517 };
518 
519 #define	tcps_rcvmemdrop	tcps_rcvreassfull	/* compat */
520 
521 #ifdef _KERNEL
522 #include <sys/counter.h>
523 
524 VNET_PCPUSTAT_DECLARE(struct tcpstat, tcpstat);	/* tcp statistics */
525 /*
526  * In-kernel consumers can use these accessor macros directly to update
527  * stats.
528  */
529 #define	TCPSTAT_ADD(name, val)	\
530     VNET_PCPUSTAT_ADD(struct tcpstat, tcpstat, name, (val))
531 #define	TCPSTAT_INC(name)	TCPSTAT_ADD(name, 1)
532 
533 /*
534  * Kernel module consumers must use this accessor macro.
535  */
536 void	kmod_tcpstat_inc(int statnum);
537 #define	KMOD_TCPSTAT_INC(name)						\
538     kmod_tcpstat_inc(offsetof(struct tcpstat, name) / sizeof(uint64_t))
539 
540 /*
541  * TCP specific helper hook point identifiers.
542  */
543 #define	HHOOK_TCP_EST_IN		0
544 #define	HHOOK_TCP_EST_OUT		1
545 #define	HHOOK_TCP_LAST			HHOOK_TCP_EST_OUT
546 
547 struct tcp_hhook_data {
548 	struct tcpcb	*tp;
549 	struct tcphdr	*th;
550 	struct tcpopt	*to;
551 	long		len;
552 	int		tso;
553 	tcp_seq		curack;
554 };
555 #endif
556 
557 /*
558  * TCB structure exported to user-land via sysctl(3).
559  * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
560  * included.  Not all of our clients do.
561  */
562 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
563 struct xtcp_timer {
564 	int tt_rexmt;	/* retransmit timer */
565 	int tt_persist;	/* retransmit persistence */
566 	int tt_keep;	/* keepalive */
567 	int tt_2msl;	/* 2*msl TIME_WAIT timer */
568 	int tt_delack;	/* delayed ACK timer */
569 	int t_rcvtime;	/* Time since last packet received */
570 };
571 struct	xtcpcb {
572 	size_t	xt_len;
573 	struct	inpcb	xt_inp;
574 	struct	tcpcb	xt_tp;
575 	struct	xsocket	xt_socket;
576 	struct	xtcp_timer xt_timer;
577 	u_quad_t	xt_alignment_hack;
578 };
579 #endif
580 
581 /*
582  * Identifiers for TCP sysctl nodes
583  */
584 #define	TCPCTL_DO_RFC1323	1	/* use RFC-1323 extensions */
585 #define	TCPCTL_MSSDFLT		3	/* MSS default */
586 #define TCPCTL_STATS		4	/* statistics (read-only) */
587 #define	TCPCTL_RTTDFLT		5	/* default RTT estimate */
588 #define	TCPCTL_KEEPIDLE		6	/* keepalive idle timer */
589 #define	TCPCTL_KEEPINTVL	7	/* interval to send keepalives */
590 #define	TCPCTL_SENDSPACE	8	/* send buffer space */
591 #define	TCPCTL_RECVSPACE	9	/* receive buffer space */
592 #define	TCPCTL_KEEPINIT		10	/* timeout for establishing syn */
593 #define	TCPCTL_PCBLIST		11	/* list of all outstanding PCBs */
594 #define	TCPCTL_DELACKTIME	12	/* time before sending delayed ACK */
595 #define	TCPCTL_V6MSSDFLT	13	/* MSS default for IPv6 */
596 #define	TCPCTL_SACK		14	/* Selective Acknowledgement,rfc 2018 */
597 #define	TCPCTL_DROP		15	/* drop tcp connection */
598 
599 #ifdef _KERNEL
600 #ifdef SYSCTL_DECL
601 SYSCTL_DECL(_net_inet_tcp);
602 SYSCTL_DECL(_net_inet_tcp_sack);
603 MALLOC_DECLARE(M_TCPLOG);
604 #endif
605 
606 VNET_DECLARE(struct inpcbhead, tcb);		/* queue of active tcpcb's */
607 VNET_DECLARE(struct inpcbinfo, tcbinfo);
608 extern	int tcp_log_in_vain;
609 VNET_DECLARE(int, tcp_mssdflt);	/* XXX */
610 VNET_DECLARE(int, tcp_minmss);
611 VNET_DECLARE(int, tcp_delack_enabled);
612 VNET_DECLARE(int, tcp_do_rfc3390);
613 VNET_DECLARE(int, tcp_do_initcwnd10);
614 VNET_DECLARE(int, tcp_sendspace);
615 VNET_DECLARE(int, tcp_recvspace);
616 VNET_DECLARE(int, path_mtu_discovery);
617 VNET_DECLARE(int, tcp_do_rfc3465);
618 VNET_DECLARE(int, tcp_abc_l_var);
619 #define	V_tcb			VNET(tcb)
620 #define	V_tcbinfo		VNET(tcbinfo)
621 #define	V_tcp_mssdflt		VNET(tcp_mssdflt)
622 #define	V_tcp_minmss		VNET(tcp_minmss)
623 #define	V_tcp_delack_enabled	VNET(tcp_delack_enabled)
624 #define	V_tcp_do_rfc3390	VNET(tcp_do_rfc3390)
625 #define	V_tcp_do_initcwnd10	VNET(tcp_do_initcwnd10)
626 #define	V_tcp_sendspace		VNET(tcp_sendspace)
627 #define	V_tcp_recvspace		VNET(tcp_recvspace)
628 #define	V_path_mtu_discovery	VNET(path_mtu_discovery)
629 #define	V_tcp_do_rfc3465	VNET(tcp_do_rfc3465)
630 #define	V_tcp_abc_l_var		VNET(tcp_abc_l_var)
631 
632 VNET_DECLARE(int, tcp_do_sack);			/* SACK enabled/disabled */
633 VNET_DECLARE(int, tcp_sc_rst_sock_fail);	/* RST on sock alloc failure */
634 #define	V_tcp_do_sack		VNET(tcp_do_sack)
635 #define	V_tcp_sc_rst_sock_fail	VNET(tcp_sc_rst_sock_fail)
636 
637 VNET_DECLARE(int, tcp_do_ecn);			/* TCP ECN enabled/disabled */
638 VNET_DECLARE(int, tcp_ecn_maxretries);
639 #define	V_tcp_do_ecn		VNET(tcp_do_ecn)
640 #define	V_tcp_ecn_maxretries	VNET(tcp_ecn_maxretries)
641 
642 VNET_DECLARE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST + 1]);
643 #define	V_tcp_hhh		VNET(tcp_hhh)
644 
645 int	 tcp_addoptions(struct tcpopt *, u_char *);
646 int	 tcp_ccalgounload(struct cc_algo *unload_algo);
647 struct tcpcb *
648 	 tcp_close(struct tcpcb *);
649 void	 tcp_discardcb(struct tcpcb *);
650 void	 tcp_twstart(struct tcpcb *);
651 void	 tcp_twclose(struct tcptw *, int);
652 void	 tcp_ctlinput(int, struct sockaddr *, void *);
653 int	 tcp_ctloutput(struct socket *, struct sockopt *);
654 struct tcpcb *
655 	 tcp_drop(struct tcpcb *, int);
656 void	 tcp_drain(void);
657 void	 tcp_init(void);
658 #ifdef VIMAGE
659 void	 tcp_destroy(void);
660 #endif
661 void	 tcp_fini(void *);
662 char	*tcp_log_addrs(struct in_conninfo *, struct tcphdr *, void *,
663 	    const void *);
664 char	*tcp_log_vain(struct in_conninfo *, struct tcphdr *, void *,
665 	    const void *);
666 int	 tcp_reass(struct tcpcb *, struct tcphdr *, int *, struct mbuf *);
667 void	 tcp_reass_global_init(void);
668 void	 tcp_reass_flush(struct tcpcb *);
669 int	 tcp_input(struct mbuf **, int *, int);
670 u_long	 tcp_maxmtu(struct in_conninfo *, struct tcp_ifcap *);
671 u_long	 tcp_maxmtu6(struct in_conninfo *, struct tcp_ifcap *);
672 void	 tcp_mss_update(struct tcpcb *, int, int, struct hc_metrics_lite *,
673 	    struct tcp_ifcap *);
674 void	 tcp_mss(struct tcpcb *, int);
675 int	 tcp_mssopt(struct in_conninfo *);
676 struct inpcb *
677 	 tcp_drop_syn_sent(struct inpcb *, int);
678 struct tcpcb *
679 	 tcp_newtcpcb(struct inpcb *);
680 int	 tcp_output(struct tcpcb *);
681 void	 tcp_state_change(struct tcpcb *, int);
682 void	 tcp_respond(struct tcpcb *, void *,
683 	    struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
684 void	 tcp_tw_init(void);
685 #ifdef VIMAGE
686 void	 tcp_tw_destroy(void);
687 #endif
688 void	 tcp_tw_zone_change(void);
689 int	 tcp_twcheck(struct inpcb *, struct tcpopt *, struct tcphdr *,
690 	    struct mbuf *, int);
691 void	 tcp_setpersist(struct tcpcb *);
692 #ifdef TCP_SIGNATURE
693 struct secasvar;
694 struct secasvar *tcp_get_sav(struct mbuf *, u_int);
695 int	 tcp_signature_do_compute(struct mbuf *, int, int, u_char *,
696 	    struct secasvar *);
697 int	 tcp_signature_compute(struct mbuf *, int, int, int, u_char *, u_int);
698 int	 tcp_signature_verify(struct mbuf *, int, int, int, struct tcpopt *,
699 	    struct tcphdr *, u_int);
700 int	tcp_signature_check(struct mbuf *m, int off0, int tlen, int optlen,
701 	    struct tcpopt *to, struct tcphdr *th, u_int tcpbflag);
702 #endif
703 void	 tcp_slowtimo(void);
704 struct tcptemp *
705 	 tcpip_maketemplate(struct inpcb *);
706 void	 tcpip_fillheaders(struct inpcb *, void *, void *);
707 void	 tcp_timer_activate(struct tcpcb *, uint32_t, u_int);
708 int	 tcp_timer_active(struct tcpcb *, uint32_t);
709 void	 tcp_timer_stop(struct tcpcb *, uint32_t);
710 void	 tcp_trace(short, short, struct tcpcb *, void *, struct tcphdr *, int);
711 /*
712  * All tcp_hc_* functions are IPv4 and IPv6 (via in_conninfo)
713  */
714 void	 tcp_hc_init(void);
715 #ifdef VIMAGE
716 void	 tcp_hc_destroy(void);
717 #endif
718 void	 tcp_hc_get(struct in_conninfo *, struct hc_metrics_lite *);
719 u_long	 tcp_hc_getmtu(struct in_conninfo *);
720 void	 tcp_hc_updatemtu(struct in_conninfo *, u_long);
721 void	 tcp_hc_update(struct in_conninfo *, struct hc_metrics_lite *);
722 
723 extern	struct pr_usrreqs tcp_usrreqs;
724 tcp_seq tcp_new_isn(struct tcpcb *);
725 
726 void	 tcp_sack_doack(struct tcpcb *, struct tcpopt *, tcp_seq);
727 void	 tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend);
728 void	 tcp_clean_sackreport(struct tcpcb *tp);
729 void	 tcp_sack_adjust(struct tcpcb *tp);
730 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt);
731 void	 tcp_sack_partialack(struct tcpcb *, struct tcphdr *);
732 void	 tcp_free_sackholes(struct tcpcb *tp);
733 int	 tcp_newreno(struct tcpcb *, struct tcphdr *);
734 u_long	 tcp_seq_subtract(u_long, u_long );
735 
736 void	cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type);
737 
738 static inline void
739 tcp_fields_to_host(struct tcphdr *th)
740 {
741 
742 	th->th_seq = ntohl(th->th_seq);
743 	th->th_ack = ntohl(th->th_ack);
744 	th->th_win = ntohs(th->th_win);
745 	th->th_urp = ntohs(th->th_urp);
746 }
747 
748 #ifdef TCP_SIGNATURE
749 static inline void
750 tcp_fields_to_net(struct tcphdr *th)
751 {
752 
753 	th->th_seq = htonl(th->th_seq);
754 	th->th_ack = htonl(th->th_ack);
755 	th->th_win = htons(th->th_win);
756 	th->th_urp = htons(th->th_urp);
757 }
758 #endif
759 #endif /* _KERNEL */
760 
761 #endif /* _NETINET_TCP_VAR_H_ */
762