xref: /freebsd/sys/netinet/tcp_var.h (revision a223d3ed90bfe313ce5987d468a25a915d7d1254)
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 struct sackblk {
50 	tcp_seq start;		/* start seq no. of sack block */
51 	tcp_seq end;		/* end seq no. */
52 };
53 
54 struct sackhole {
55 	tcp_seq start;		/* start seq no. of hole */
56 	tcp_seq end;		/* end seq no. */
57 	tcp_seq rxmit;		/* next seq. no in hole to be retransmitted */
58 	TAILQ_ENTRY(sackhole) scblink;	/* scoreboard linkage */
59 };
60 
61 struct sackhint {
62 	struct sackhole	*nexthole;
63 	int		sack_bytes_rexmit;
64 	tcp_seq		last_sack_ack;	/* Most recent/largest sacked ack */
65 
66 	int		ispare;		/* explicit pad for 64bit alignment */
67 	uint64_t	_pad[2];	/* 1 sacked_bytes, 1 TBD */
68 };
69 
70 struct tcptemp {
71 	u_char	tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
72 	struct	tcphdr tt_t;
73 };
74 
75 #define tcp6cb		tcpcb  /* for KAME src sync over BSD*'s */
76 
77 /* Neighbor Discovery, Neighbor Unreachability Detection Upper layer hint. */
78 #ifdef INET6
79 #define ND6_HINT(tp)						\
80 do {								\
81 	if ((tp) && (tp)->t_inpcb &&				\
82 	    ((tp)->t_inpcb->inp_vflag & INP_IPV6) != 0)		\
83 		nd6_nud_hint(NULL, NULL, 0);			\
84 } while (0)
85 #else
86 #define ND6_HINT(tp)
87 #endif
88 
89 /*
90  * Tcp control block, one per tcp; fields:
91  * Organized for 16 byte cacheline efficiency.
92  */
93 struct tcpcb {
94 	struct	mbuf *t_segq;		/* segment reassembly queue */
95 	void	*t_pspare[2];		/* new reassembly queue */
96 	int	t_segqlen;		/* segment reassembly queue length */
97 	int	t_dupacks;		/* consecutive dup acks recd */
98 
99 	struct tcp_timer *t_timers;	/* All the TCP timers in one struct */
100 
101 	struct	inpcb *t_inpcb;		/* back pointer to internet pcb */
102 	int	t_state;		/* state of this connection */
103 	u_int	t_flags;
104 
105 	struct	vnet *t_vnet;		/* back pointer to parent vnet */
106 
107 	tcp_seq	snd_una;		/* send unacknowledged */
108 	tcp_seq	snd_max;		/* highest sequence number sent;
109 					 * used to recognize retransmits
110 					 */
111 	tcp_seq	snd_nxt;		/* send next */
112 	tcp_seq	snd_up;			/* send urgent pointer */
113 
114 	tcp_seq	snd_wl1;		/* window update seg seq number */
115 	tcp_seq	snd_wl2;		/* window update seg ack number */
116 	tcp_seq	iss;			/* initial send sequence number */
117 	tcp_seq	irs;			/* initial receive sequence number */
118 
119 	tcp_seq	rcv_nxt;		/* receive next */
120 	tcp_seq	rcv_adv;		/* advertised window */
121 	u_long	rcv_wnd;		/* receive window */
122 	tcp_seq	rcv_up;			/* receive urgent pointer */
123 
124 	u_long	snd_wnd;		/* send window */
125 	u_long	snd_cwnd;		/* congestion-controlled window */
126 	u_long	snd_spare1;		/* unused */
127 	u_long	snd_ssthresh;		/* snd_cwnd size threshold for
128 					 * for slow start exponential to
129 					 * linear switch
130 					 */
131 	u_long	snd_spare2;		/* unused */
132 	tcp_seq	snd_recover;		/* for use in NewReno Fast Recovery */
133 
134 	u_int	t_maxopd;		/* mss plus options */
135 
136 	u_int	t_rcvtime;		/* inactivity time */
137 	u_int	t_starttime;		/* time connection was established */
138 	u_int	t_rtttime;		/* RTT measurement start time */
139 	tcp_seq	t_rtseq;		/* sequence number being timed */
140 
141 	u_int	t_bw_spare1;		/* unused */
142 	tcp_seq	t_bw_spare2;		/* unused */
143 
144 	int	t_rxtcur;		/* current retransmit value (ticks) */
145 	u_int	t_maxseg;		/* maximum segment size */
146 	int	t_srtt;			/* smoothed round-trip time */
147 	int	t_rttvar;		/* variance in round-trip time */
148 
149 	int	t_rxtshift;		/* log(2) of rexmt exp. backoff */
150 	u_int	t_rttmin;		/* minimum rtt allowed */
151 	u_int	t_rttbest;		/* best rtt we've seen */
152 	u_long	t_rttupdated;		/* number of times rtt sampled */
153 	u_long	max_sndwnd;		/* largest window peer has offered */
154 
155 	int	t_softerror;		/* possible error not yet reported */
156 /* out-of-band data */
157 	char	t_oobflags;		/* have some */
158 	char	t_iobc;			/* input character */
159 /* RFC 1323 variables */
160 	u_char	snd_scale;		/* window scaling for send window */
161 	u_char	rcv_scale;		/* window scaling for recv window */
162 	u_char	request_r_scale;	/* pending window scaling */
163 	u_int32_t  ts_recent;		/* timestamp echo data */
164 	u_int	ts_recent_age;		/* when last updated */
165 	u_int32_t  ts_offset;		/* our timestamp offset */
166 
167 	tcp_seq	last_ack_sent;
168 /* experimental */
169 	u_long	snd_cwnd_prev;		/* cwnd prior to retransmit */
170 	u_long	snd_ssthresh_prev;	/* ssthresh prior to retransmit */
171 	tcp_seq	snd_recover_prev;	/* snd_recover prior to retransmit */
172 	int	t_sndzerowin;		/* zero-window updates sent */
173 	u_int	t_badrxtwin;		/* window for retransmit recovery */
174 	u_char	snd_limited;		/* segments limited transmitted */
175 /* SACK related state */
176 	int	snd_numholes;		/* number of holes seen by sender */
177 	TAILQ_HEAD(sackhole_head, sackhole) snd_holes;
178 					/* SACK scoreboard (sorted) */
179 	tcp_seq	snd_fack;		/* last seq number(+1) sack'd by rcv'r*/
180 	int	rcv_numsacks;		/* # distinct sack blks present */
181 	struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
182 	tcp_seq sack_newdata;		/* New data xmitted in this recovery
183 					   episode starts at this seq number */
184 	struct sackhint	sackhint;	/* SACK scoreboard hint */
185 	int	t_rttlow;		/* smallest observerved RTT */
186 	u_int32_t	rfbuf_ts;	/* recv buffer autoscaling timestamp */
187 	int	rfbuf_cnt;		/* recv buffer autoscaling byte count */
188 	struct toedev	*tod;		/* toedev handling this connection */
189 	int	t_sndrexmitpack;	/* retransmit packets sent */
190 	int	t_rcvoopack;		/* out-of-order packets received */
191 	void	*t_toe;			/* TOE pcb pointer */
192 	int	t_bytes_acked;		/* # bytes acked during current RTT */
193 	struct cc_algo	*cc_algo;	/* congestion control algorithm */
194 	struct cc_var	*ccv;		/* congestion control specific vars */
195 	struct osd	*osd;		/* storage for Khelp module data */
196 
197 	u_int	t_keepinit;		/* time to establish connection */
198 	u_int	t_keepidle;		/* time before keepalive probes begin */
199 	u_int	t_keepintvl;		/* interval between keepalives */
200 	u_int	t_keepcnt;		/* number of keepalives before close */
201 
202 	u_int	t_tsomax;		/* tso burst length limit */
203 
204 	uint32_t t_ispare[8];		/* 5 UTO, 3 TBD */
205 	void	*t_pspare2[4];		/* 1 TCP_SIGNATURE, 3 TBD */
206 	uint64_t _pad[6];		/* 6 TBD (1-2 CC/RTT?) */
207 };
208 
209 /*
210  * Flags and utility macros for the t_flags field.
211  */
212 #define	TF_ACKNOW	0x000001	/* ack peer immediately */
213 #define	TF_DELACK	0x000002	/* ack, but try to delay it */
214 #define	TF_NODELAY	0x000004	/* don't delay packets to coalesce */
215 #define	TF_NOOPT	0x000008	/* don't use tcp options */
216 #define	TF_SENTFIN	0x000010	/* have sent FIN */
217 #define	TF_REQ_SCALE	0x000020	/* have/will request window scaling */
218 #define	TF_RCVD_SCALE	0x000040	/* other side has requested scaling */
219 #define	TF_REQ_TSTMP	0x000080	/* have/will request timestamps */
220 #define	TF_RCVD_TSTMP	0x000100	/* a timestamp was received in SYN */
221 #define	TF_SACK_PERMIT	0x000200	/* other side said I could SACK */
222 #define	TF_NEEDSYN	0x000400	/* send SYN (implicit state) */
223 #define	TF_NEEDFIN	0x000800	/* send FIN (implicit state) */
224 #define	TF_NOPUSH	0x001000	/* don't push */
225 #define	TF_PREVVALID	0x002000	/* saved values for bad rxmit valid */
226 #define	TF_MORETOCOME	0x010000	/* More data to be appended to sock */
227 #define	TF_LQ_OVERFLOW	0x020000	/* listen queue overflow */
228 #define	TF_LASTIDLE	0x040000	/* connection was previously idle */
229 #define	TF_RXWIN0SENT	0x080000	/* sent a receiver win 0 in response */
230 #define	TF_FASTRECOVERY	0x100000	/* in NewReno Fast Recovery */
231 #define	TF_WASFRECOVERY	0x200000	/* was in NewReno Fast Recovery */
232 #define	TF_SIGNATURE	0x400000	/* require MD5 digests (RFC2385) */
233 #define	TF_FORCEDATA	0x800000	/* force out a byte */
234 #define	TF_TSO		0x1000000	/* TSO enabled on this connection */
235 #define	TF_TOE		0x2000000	/* this connection is offloaded */
236 #define	TF_ECN_PERMIT	0x4000000	/* connection ECN-ready */
237 #define	TF_ECN_SND_CWR	0x8000000	/* ECN CWR in queue */
238 #define	TF_ECN_SND_ECE	0x10000000	/* ECN ECE in queue */
239 #define	TF_CONGRECOVERY	0x20000000	/* congestion recovery mode */
240 #define	TF_WASCRECOVERY	0x40000000	/* was in congestion recovery */
241 
242 #define	IN_FASTRECOVERY(t_flags)	(t_flags & TF_FASTRECOVERY)
243 #define	ENTER_FASTRECOVERY(t_flags)	t_flags |= TF_FASTRECOVERY
244 #define	EXIT_FASTRECOVERY(t_flags)	t_flags &= ~TF_FASTRECOVERY
245 
246 #define	IN_CONGRECOVERY(t_flags)	(t_flags & TF_CONGRECOVERY)
247 #define	ENTER_CONGRECOVERY(t_flags)	t_flags |= TF_CONGRECOVERY
248 #define	EXIT_CONGRECOVERY(t_flags)	t_flags &= ~TF_CONGRECOVERY
249 
250 #define	IN_RECOVERY(t_flags) (t_flags & (TF_CONGRECOVERY | TF_FASTRECOVERY))
251 #define	ENTER_RECOVERY(t_flags) t_flags |= (TF_CONGRECOVERY | TF_FASTRECOVERY)
252 #define	EXIT_RECOVERY(t_flags) t_flags &= ~(TF_CONGRECOVERY | TF_FASTRECOVERY)
253 
254 #define	BYTES_THIS_ACK(tp, th)	(th->th_ack - tp->snd_una)
255 
256 /*
257  * Flags for the t_oobflags field.
258  */
259 #define	TCPOOB_HAVEDATA	0x01
260 #define	TCPOOB_HADDATA	0x02
261 
262 #ifdef TCP_SIGNATURE
263 /*
264  * Defines which are needed by the xform_tcp module and tcp_[in|out]put
265  * for SADB verification and lookup.
266  */
267 #define	TCP_SIGLEN	16	/* length of computed digest in bytes */
268 #define	TCP_KEYLEN_MIN	1	/* minimum length of TCP-MD5 key */
269 #define	TCP_KEYLEN_MAX	80	/* maximum length of TCP-MD5 key */
270 /*
271  * Only a single SA per host may be specified at this time. An SPI is
272  * needed in order for the KEY_ALLOCSA() lookup to work.
273  */
274 #define	TCP_SIG_SPI	0x1000
275 #endif /* TCP_SIGNATURE */
276 
277 /*
278  * Structure to hold TCP options that are only used during segment
279  * processing (in tcp_input), but not held in the tcpcb.
280  * It's basically used to reduce the number of parameters
281  * to tcp_dooptions and tcp_addoptions.
282  * The binary order of the to_flags is relevant for packing of the
283  * options in tcp_addoptions.
284  */
285 struct tcpopt {
286 	u_int64_t	to_flags;	/* which options are present */
287 #define	TOF_MSS		0x0001		/* maximum segment size */
288 #define	TOF_SCALE	0x0002		/* window scaling */
289 #define	TOF_SACKPERM	0x0004		/* SACK permitted */
290 #define	TOF_TS		0x0010		/* timestamp */
291 #define	TOF_SIGNATURE	0x0040		/* TCP-MD5 signature option (RFC2385) */
292 #define	TOF_SACK	0x0080		/* Peer sent SACK option */
293 #define	TOF_MAXOPT	0x0100
294 	u_int32_t	to_tsval;	/* new timestamp */
295 	u_int32_t	to_tsecr;	/* reflected timestamp */
296 	u_char		*to_sacks;	/* pointer to the first SACK blocks */
297 	u_char		*to_signature;	/* pointer to the TCP-MD5 signature */
298 	u_int16_t	to_mss;		/* maximum segment size */
299 	u_int8_t	to_wscale;	/* window scaling */
300 	u_int8_t	to_nsacks;	/* number of SACK blocks */
301 	u_int32_t	to_spare;	/* UTO */
302 };
303 
304 /*
305  * Flags for tcp_dooptions.
306  */
307 #define	TO_SYN		0x01		/* parse SYN-only options */
308 
309 struct hc_metrics_lite {	/* must stay in sync with hc_metrics */
310 	u_long	rmx_mtu;	/* MTU for this path */
311 	u_long	rmx_ssthresh;	/* outbound gateway buffer limit */
312 	u_long	rmx_rtt;	/* estimated round trip time */
313 	u_long	rmx_rttvar;	/* estimated rtt variance */
314 	u_long	rmx_bandwidth;	/* estimated bandwidth */
315 	u_long	rmx_cwnd;	/* congestion window */
316 	u_long	rmx_sendpipe;   /* outbound delay-bandwidth product */
317 	u_long	rmx_recvpipe;   /* inbound delay-bandwidth product */
318 };
319 
320 /*
321  * Used by tcp_maxmtu() to communicate interface specific features
322  * and limits at the time of connection setup.
323  */
324 struct tcp_ifcap {
325 	int	ifcap;
326 	u_int	tsomax;
327 };
328 
329 #ifndef _NETINET_IN_PCB_H_
330 struct in_conninfo;
331 #endif /* _NETINET_IN_PCB_H_ */
332 
333 struct tcptw {
334 	struct inpcb	*tw_inpcb;	/* XXX back pointer to internet pcb */
335 	tcp_seq		snd_nxt;
336 	tcp_seq		rcv_nxt;
337 	tcp_seq		iss;
338 	tcp_seq		irs;
339 	u_short		last_win;	/* cached window value */
340 	u_short		tw_so_options;	/* copy of so_options */
341 	struct ucred	*tw_cred;	/* user credentials */
342 	u_int32_t	t_recent;
343 	u_int32_t	ts_offset;	/* our timestamp offset */
344 	u_int		t_starttime;
345 	int		tw_time;
346 	TAILQ_ENTRY(tcptw) tw_2msl;
347 	u_int		tw_refcount;	/* refcount */
348 };
349 
350 #define	intotcpcb(ip)	((struct tcpcb *)(ip)->inp_ppcb)
351 #define	intotw(ip)	((struct tcptw *)(ip)->inp_ppcb)
352 #define	sototcpcb(so)	(intotcpcb(sotoinpcb(so)))
353 
354 /*
355  * The smoothed round-trip time and estimated variance
356  * are stored as fixed point numbers scaled by the values below.
357  * For convenience, these scales are also used in smoothing the average
358  * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
359  * With these scales, srtt has 3 bits to the right of the binary point,
360  * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
361  * binary point, and is smoothed with an ALPHA of 0.75.
362  */
363 #define	TCP_RTT_SCALE		32	/* multiplier for srtt; 3 bits frac. */
364 #define	TCP_RTT_SHIFT		5	/* shift for srtt; 3 bits frac. */
365 #define	TCP_RTTVAR_SCALE	16	/* multiplier for rttvar; 2 bits */
366 #define	TCP_RTTVAR_SHIFT	4	/* shift for rttvar; 2 bits */
367 #define	TCP_DELTA_SHIFT		2	/* see tcp_input.c */
368 
369 /*
370  * The initial retransmission should happen at rtt + 4 * rttvar.
371  * Because of the way we do the smoothing, srtt and rttvar
372  * will each average +1/2 tick of bias.  When we compute
373  * the retransmit timer, we want 1/2 tick of rounding and
374  * 1 extra tick because of +-1/2 tick uncertainty in the
375  * firing of the timer.  The bias will give us exactly the
376  * 1.5 tick we need.  But, because the bias is
377  * statistical, we have to test that we don't drop below
378  * the minimum feasible timer (which is 2 ticks).
379  * This version of the macro adapted from a paper by Lawrence
380  * Brakmo and Larry Peterson which outlines a problem caused
381  * by insufficient precision in the original implementation,
382  * which results in inappropriately large RTO values for very
383  * fast networks.
384  */
385 #define	TCP_REXMTVAL(tp) \
386 	max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
387 	  + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
388 
389 /*
390  * TCP statistics.
391  * Many of these should be kept per connection,
392  * but that's inconvenient at the moment.
393  */
394 struct	tcpstat {
395 	uint64_t tcps_connattempt;	/* connections initiated */
396 	uint64_t tcps_accepts;		/* connections accepted */
397 	uint64_t tcps_connects;		/* connections established */
398 	uint64_t tcps_drops;		/* connections dropped */
399 	uint64_t tcps_conndrops;	/* embryonic connections dropped */
400 	uint64_t tcps_minmssdrops;	/* average minmss too low drops */
401 	uint64_t tcps_closed;		/* conn. closed (includes drops) */
402 	uint64_t tcps_segstimed;	/* segs where we tried to get rtt */
403 	uint64_t tcps_rttupdated;	/* times we succeeded */
404 	uint64_t tcps_delack;		/* delayed acks sent */
405 	uint64_t tcps_timeoutdrop;	/* conn. dropped in rxmt timeout */
406 	uint64_t tcps_rexmttimeo;	/* retransmit timeouts */
407 	uint64_t tcps_persisttimeo;	/* persist timeouts */
408 	uint64_t tcps_keeptimeo;	/* keepalive timeouts */
409 	uint64_t tcps_keepprobe;	/* keepalive probes sent */
410 	uint64_t tcps_keepdrops;	/* connections dropped in keepalive */
411 
412 	uint64_t tcps_sndtotal;		/* total packets sent */
413 	uint64_t tcps_sndpack;		/* data packets sent */
414 	uint64_t tcps_sndbyte;		/* data bytes sent */
415 	uint64_t tcps_sndrexmitpack;	/* data packets retransmitted */
416 	uint64_t tcps_sndrexmitbyte;	/* data bytes retransmitted */
417 	uint64_t tcps_sndrexmitbad;	/* unnecessary packet retransmissions */
418 	uint64_t tcps_sndacks;		/* ack-only packets sent */
419 	uint64_t tcps_sndprobe;		/* window probes sent */
420 	uint64_t tcps_sndurg;		/* packets sent with URG only */
421 	uint64_t tcps_sndwinup;		/* window update-only packets sent */
422 	uint64_t tcps_sndctrl;		/* control (SYN|FIN|RST) packets sent */
423 
424 	uint64_t tcps_rcvtotal;		/* total packets received */
425 	uint64_t tcps_rcvpack;		/* packets received in sequence */
426 	uint64_t tcps_rcvbyte;		/* bytes received in sequence */
427 	uint64_t tcps_rcvbadsum;	/* packets received with ccksum errs */
428 	uint64_t tcps_rcvbadoff;	/* packets received with bad offset */
429 	uint64_t tcps_rcvreassfull;	/* packets dropped for no reass space */
430 	uint64_t tcps_rcvshort;		/* packets received too short */
431 	uint64_t tcps_rcvduppack;	/* duplicate-only packets received */
432 	uint64_t tcps_rcvdupbyte;	/* duplicate-only bytes received */
433 	uint64_t tcps_rcvpartduppack;	/* packets with some duplicate data */
434 	uint64_t tcps_rcvpartdupbyte;	/* dup. bytes in part-dup. packets */
435 	uint64_t tcps_rcvoopack;	/* out-of-order packets received */
436 	uint64_t tcps_rcvoobyte;	/* out-of-order bytes received */
437 	uint64_t tcps_rcvpackafterwin;	/* packets with data after window */
438 	uint64_t tcps_rcvbyteafterwin;	/* bytes rcvd after window */
439 	uint64_t tcps_rcvafterclose;	/* packets rcvd after "close" */
440 	uint64_t tcps_rcvwinprobe;	/* rcvd window probe packets */
441 	uint64_t tcps_rcvdupack;	/* rcvd duplicate acks */
442 	uint64_t tcps_rcvacktoomuch;	/* rcvd acks for unsent data */
443 	uint64_t tcps_rcvackpack;	/* rcvd ack packets */
444 	uint64_t tcps_rcvackbyte;	/* bytes acked by rcvd acks */
445 	uint64_t tcps_rcvwinupd;	/* rcvd window update packets */
446 	uint64_t tcps_pawsdrop;		/* segments dropped due to PAWS */
447 	uint64_t tcps_predack;		/* times hdr predict ok for acks */
448 	uint64_t tcps_preddat;		/* times hdr predict ok for data pkts */
449 	uint64_t tcps_pcbcachemiss;
450 	uint64_t tcps_cachedrtt;	/* times cached RTT in route updated */
451 	uint64_t tcps_cachedrttvar;	/* times cached rttvar updated */
452 	uint64_t tcps_cachedssthresh;	/* times cached ssthresh updated */
453 	uint64_t tcps_usedrtt;		/* times RTT initialized from route */
454 	uint64_t tcps_usedrttvar;	/* times RTTVAR initialized from rt */
455 	uint64_t tcps_usedssthresh;	/* times ssthresh initialized from rt*/
456 	uint64_t tcps_persistdrop;	/* timeout in persist state */
457 	uint64_t tcps_badsyn;		/* bogus SYN, e.g. premature ACK */
458 	uint64_t tcps_mturesent;	/* resends due to MTU discovery */
459 	uint64_t tcps_listendrop;	/* listen queue overflows */
460 	uint64_t tcps_badrst;		/* ignored RSTs in the window */
461 
462 	uint64_t tcps_sc_added;		/* entry added to syncache */
463 	uint64_t tcps_sc_retransmitted;	/* syncache entry was retransmitted */
464 	uint64_t tcps_sc_dupsyn;	/* duplicate SYN packet */
465 	uint64_t tcps_sc_dropped;	/* could not reply to packet */
466 	uint64_t tcps_sc_completed;	/* successful extraction of entry */
467 	uint64_t tcps_sc_bucketoverflow;/* syncache per-bucket limit hit */
468 	uint64_t tcps_sc_cacheoverflow;	/* syncache cache limit hit */
469 	uint64_t tcps_sc_reset;		/* RST removed entry from syncache */
470 	uint64_t tcps_sc_stale;		/* timed out or listen socket gone */
471 	uint64_t tcps_sc_aborted;	/* syncache entry aborted */
472 	uint64_t tcps_sc_badack;	/* removed due to bad ACK */
473 	uint64_t tcps_sc_unreach;	/* ICMP unreachable received */
474 	uint64_t tcps_sc_zonefail;	/* zalloc() failed */
475 	uint64_t tcps_sc_sendcookie;	/* SYN cookie sent */
476 	uint64_t tcps_sc_recvcookie;	/* SYN cookie received */
477 
478 	uint64_t tcps_hc_added;		/* entry added to hostcache */
479 	uint64_t tcps_hc_bucketoverflow;/* hostcache per bucket limit hit */
480 
481 	uint64_t tcps_finwait2_drops;    /* Drop FIN_WAIT_2 connection after time limit */
482 
483 	/* SACK related stats */
484 	uint64_t tcps_sack_recovery_episode; /* SACK recovery episodes */
485 	uint64_t tcps_sack_rexmits;	    /* SACK rexmit segments   */
486 	uint64_t tcps_sack_rexmit_bytes;    /* SACK rexmit bytes      */
487 	uint64_t tcps_sack_rcv_blocks;	    /* SACK blocks (options) received */
488 	uint64_t tcps_sack_send_blocks;	    /* SACK blocks (options) sent     */
489 	uint64_t tcps_sack_sboverflow;	    /* times scoreboard overflowed */
490 
491 	/* ECN related stats */
492 	uint64_t tcps_ecn_ce;		/* ECN Congestion Experienced */
493 	uint64_t tcps_ecn_ect0;		/* ECN Capable Transport */
494 	uint64_t tcps_ecn_ect1;		/* ECN Capable Transport */
495 	uint64_t tcps_ecn_shs;		/* ECN successful handshakes */
496 	uint64_t tcps_ecn_rcwnd;	/* # times ECN reduced the cwnd */
497 
498 	/* TCP_SIGNATURE related stats */
499 	uint64_t tcps_sig_rcvgoodsig;	/* Total matching signature received */
500 	uint64_t tcps_sig_rcvbadsig;	/* Total bad signature received */
501 	uint64_t tcps_sig_err_buildsig;	/* Mismatching signature received */
502 	uint64_t tcps_sig_err_sigopt;	/* No signature expected by socket */
503 	uint64_t tcps_sig_err_nosigopt;	/* No signature provided by segment */
504 
505 	uint64_t _pad[12];		/* 6 UTO, 6 TBD */
506 };
507 
508 #define	tcps_rcvmemdrop	tcps_rcvreassfull	/* compat */
509 
510 #ifdef _KERNEL
511 #include <sys/counter.h>
512 
513 VNET_PCPUSTAT_DECLARE(struct tcpstat, tcpstat);	/* tcp statistics */
514 /*
515  * In-kernel consumers can use these accessor macros directly to update
516  * stats.
517  */
518 #define	TCPSTAT_ADD(name, val)	\
519     VNET_PCPUSTAT_ADD(struct tcpstat, tcpstat, name, (val))
520 #define	TCPSTAT_INC(name)	TCPSTAT_ADD(name, 1)
521 
522 /*
523  * Kernel module consumers must use this accessor macro.
524  */
525 void	kmod_tcpstat_inc(int statnum);
526 #define	KMOD_TCPSTAT_INC(name)						\
527     kmod_tcpstat_inc(offsetof(struct tcpstat, name) / sizeof(uint64_t))
528 
529 /*
530  * TCP specific helper hook point identifiers.
531  */
532 #define	HHOOK_TCP_EST_IN		0
533 #define	HHOOK_TCP_EST_OUT		1
534 #define	HHOOK_TCP_LAST			HHOOK_TCP_EST_OUT
535 
536 struct tcp_hhook_data {
537 	struct tcpcb	*tp;
538 	struct tcphdr	*th;
539 	struct tcpopt	*to;
540 	long		len;
541 	int		tso;
542 	tcp_seq		curack;
543 };
544 #endif
545 
546 /*
547  * TCB structure exported to user-land via sysctl(3).
548  * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
549  * included.  Not all of our clients do.
550  */
551 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
552 struct xtcp_timer {
553 	int tt_rexmt;	/* retransmit timer */
554 	int tt_persist;	/* retransmit persistence */
555 	int tt_keep;	/* keepalive */
556 	int tt_2msl;	/* 2*msl TIME_WAIT timer */
557 	int tt_delack;	/* delayed ACK timer */
558 	int t_rcvtime;	/* Time since last packet received */
559 };
560 struct	xtcpcb {
561 	size_t	xt_len;
562 	struct	inpcb	xt_inp;
563 	struct	tcpcb	xt_tp;
564 	struct	xsocket	xt_socket;
565 	struct	xtcp_timer xt_timer;
566 	u_quad_t	xt_alignment_hack;
567 };
568 #endif
569 
570 /*
571  * Identifiers for TCP sysctl nodes
572  */
573 #define	TCPCTL_DO_RFC1323	1	/* use RFC-1323 extensions */
574 #define	TCPCTL_MSSDFLT		3	/* MSS default */
575 #define TCPCTL_STATS		4	/* statistics (read-only) */
576 #define	TCPCTL_RTTDFLT		5	/* default RTT estimate */
577 #define	TCPCTL_KEEPIDLE		6	/* keepalive idle timer */
578 #define	TCPCTL_KEEPINTVL	7	/* interval to send keepalives */
579 #define	TCPCTL_SENDSPACE	8	/* send buffer space */
580 #define	TCPCTL_RECVSPACE	9	/* receive buffer space */
581 #define	TCPCTL_KEEPINIT		10	/* timeout for establishing syn */
582 #define	TCPCTL_PCBLIST		11	/* list of all outstanding PCBs */
583 #define	TCPCTL_DELACKTIME	12	/* time before sending delayed ACK */
584 #define	TCPCTL_V6MSSDFLT	13	/* MSS default for IPv6 */
585 #define	TCPCTL_SACK		14	/* Selective Acknowledgement,rfc 2018 */
586 #define	TCPCTL_DROP		15	/* drop tcp connection */
587 
588 #ifdef _KERNEL
589 #ifdef SYSCTL_DECL
590 SYSCTL_DECL(_net_inet_tcp);
591 SYSCTL_DECL(_net_inet_tcp_sack);
592 MALLOC_DECLARE(M_TCPLOG);
593 #endif
594 
595 VNET_DECLARE(struct inpcbhead, tcb);		/* queue of active tcpcb's */
596 VNET_DECLARE(struct inpcbinfo, tcbinfo);
597 extern	int tcp_log_in_vain;
598 VNET_DECLARE(int, tcp_mssdflt);	/* XXX */
599 VNET_DECLARE(int, tcp_minmss);
600 VNET_DECLARE(int, tcp_delack_enabled);
601 VNET_DECLARE(int, tcp_do_rfc3390);
602 VNET_DECLARE(int, tcp_do_initcwnd10);
603 VNET_DECLARE(int, tcp_sendspace);
604 VNET_DECLARE(int, tcp_recvspace);
605 VNET_DECLARE(int, path_mtu_discovery);
606 VNET_DECLARE(int, tcp_do_rfc3465);
607 VNET_DECLARE(int, tcp_abc_l_var);
608 #define	V_tcb			VNET(tcb)
609 #define	V_tcbinfo		VNET(tcbinfo)
610 #define	V_tcp_mssdflt		VNET(tcp_mssdflt)
611 #define	V_tcp_minmss		VNET(tcp_minmss)
612 #define	V_tcp_delack_enabled	VNET(tcp_delack_enabled)
613 #define	V_tcp_do_rfc3390	VNET(tcp_do_rfc3390)
614 #define	V_tcp_do_initcwnd10	VNET(tcp_do_initcwnd10)
615 #define	V_tcp_sendspace		VNET(tcp_sendspace)
616 #define	V_tcp_recvspace		VNET(tcp_recvspace)
617 #define	V_path_mtu_discovery	VNET(path_mtu_discovery)
618 #define	V_tcp_do_rfc3465	VNET(tcp_do_rfc3465)
619 #define	V_tcp_abc_l_var		VNET(tcp_abc_l_var)
620 
621 VNET_DECLARE(int, tcp_do_sack);			/* SACK enabled/disabled */
622 VNET_DECLARE(int, tcp_sc_rst_sock_fail);	/* RST on sock alloc failure */
623 #define	V_tcp_do_sack		VNET(tcp_do_sack)
624 #define	V_tcp_sc_rst_sock_fail	VNET(tcp_sc_rst_sock_fail)
625 
626 VNET_DECLARE(int, tcp_do_ecn);			/* TCP ECN enabled/disabled */
627 VNET_DECLARE(int, tcp_ecn_maxretries);
628 #define	V_tcp_do_ecn		VNET(tcp_do_ecn)
629 #define	V_tcp_ecn_maxretries	VNET(tcp_ecn_maxretries)
630 
631 VNET_DECLARE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST + 1]);
632 #define	V_tcp_hhh		VNET(tcp_hhh)
633 
634 int	 tcp_addoptions(struct tcpopt *, u_char *);
635 int	 tcp_ccalgounload(struct cc_algo *unload_algo);
636 struct tcpcb *
637 	 tcp_close(struct tcpcb *);
638 void	 tcp_discardcb(struct tcpcb *);
639 void	 tcp_twstart(struct tcpcb *);
640 void	 tcp_twclose(struct tcptw *_tw, int _reuse);
641 void	 tcp_ctlinput(int, struct sockaddr *, void *);
642 int	 tcp_ctloutput(struct socket *, struct sockopt *);
643 struct tcpcb *
644 	 tcp_drop(struct tcpcb *, int);
645 void	 tcp_drain(void);
646 void	 tcp_init(void);
647 #ifdef VIMAGE
648 void	 tcp_destroy(void);
649 #endif
650 void	 tcp_fini(void *);
651 char	*tcp_log_addrs(struct in_conninfo *, struct tcphdr *, void *,
652 	    const void *);
653 char	*tcp_log_vain(struct in_conninfo *, struct tcphdr *, void *,
654 	    const void *);
655 int	 tcp_reass(struct tcpcb *, struct tcphdr *, int *, struct mbuf *);
656 void	 tcp_reass_flush(struct tcpcb *);
657 void	 tcp_input(struct mbuf *, int);
658 u_long	 tcp_maxmtu(struct in_conninfo *, struct tcp_ifcap *);
659 u_long	 tcp_maxmtu6(struct in_conninfo *, struct tcp_ifcap *);
660 void	 tcp_mss_update(struct tcpcb *, int, int, struct hc_metrics_lite *,
661 	    struct tcp_ifcap *);
662 void	 tcp_mss(struct tcpcb *, int);
663 int	 tcp_mssopt(struct in_conninfo *);
664 struct inpcb *
665 	 tcp_drop_syn_sent(struct inpcb *, int);
666 struct inpcb *
667 	 tcp_mtudisc(struct inpcb *, int);
668 struct tcpcb *
669 	 tcp_newtcpcb(struct inpcb *);
670 int	 tcp_output(struct tcpcb *);
671 void	 tcp_state_change(struct tcpcb *, int);
672 void	 tcp_respond(struct tcpcb *, void *,
673 	    struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
674 void	 tcp_tw_init(void);
675 #ifdef VIMAGE
676 void	 tcp_tw_destroy(void);
677 #endif
678 void	 tcp_tw_zone_change(void);
679 int	 tcp_twcheck(struct inpcb *, struct tcpopt *, struct tcphdr *,
680 	    struct mbuf *, int);
681 void	 tcp_setpersist(struct tcpcb *);
682 #ifdef TCP_SIGNATURE
683 int	 tcp_signature_compute(struct mbuf *, int, int, int, u_char *, u_int);
684 int	 tcp_signature_verify(struct mbuf *, int, int, int, struct tcpopt *,
685 	    struct tcphdr *, u_int);
686 #endif
687 void	 tcp_slowtimo(void);
688 struct tcptemp *
689 	 tcpip_maketemplate(struct inpcb *);
690 void	 tcpip_fillheaders(struct inpcb *, void *, void *);
691 void	 tcp_timer_activate(struct tcpcb *, int, u_int);
692 int	 tcp_timer_active(struct tcpcb *, int);
693 void	 tcp_trace(short, short, struct tcpcb *, void *, struct tcphdr *, int);
694 /*
695  * All tcp_hc_* functions are IPv4 and IPv6 (via in_conninfo)
696  */
697 void	 tcp_hc_init(void);
698 #ifdef VIMAGE
699 void	 tcp_hc_destroy(void);
700 #endif
701 void	 tcp_hc_get(struct in_conninfo *, struct hc_metrics_lite *);
702 u_long	 tcp_hc_getmtu(struct in_conninfo *);
703 void	 tcp_hc_updatemtu(struct in_conninfo *, u_long);
704 void	 tcp_hc_update(struct in_conninfo *, struct hc_metrics_lite *);
705 
706 extern	struct pr_usrreqs tcp_usrreqs;
707 tcp_seq tcp_new_isn(struct tcpcb *);
708 
709 void	 tcp_sack_doack(struct tcpcb *, struct tcpopt *, tcp_seq);
710 void	 tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend);
711 void	 tcp_clean_sackreport(struct tcpcb *tp);
712 void	 tcp_sack_adjust(struct tcpcb *tp);
713 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt);
714 void	 tcp_sack_partialack(struct tcpcb *, struct tcphdr *);
715 void	 tcp_free_sackholes(struct tcpcb *tp);
716 int	 tcp_newreno(struct tcpcb *, struct tcphdr *);
717 u_long	 tcp_seq_subtract(u_long, u_long );
718 
719 void	cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type);
720 
721 static inline void
722 tcp_fields_to_host(struct tcphdr *th)
723 {
724 
725 	th->th_seq = ntohl(th->th_seq);
726 	th->th_ack = ntohl(th->th_ack);
727 	th->th_win = ntohs(th->th_win);
728 	th->th_urp = ntohs(th->th_urp);
729 }
730 
731 #ifdef TCP_SIGNATURE
732 static inline void
733 tcp_fields_to_net(struct tcphdr *th)
734 {
735 
736 	th->th_seq = htonl(th->th_seq);
737 	th->th_ack = htonl(th->th_ack);
738 	th->th_win = htons(th->th_win);
739 	th->th_urp = htons(th->th_urp);
740 }
741 #endif
742 #endif /* _KERNEL */
743 
744 #endif /* _NETINET_TCP_VAR_H_ */
745