xref: /freebsd/sys/netinet/tcp_var.h (revision edca4938f74db18d091868237592abbf7e718669)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1993, 1994, 1995
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)tcp_var.h	8.4 (Berkeley) 5/24/95
32  * $FreeBSD$
33  */
34 
35 #ifndef _NETINET_TCP_VAR_H_
36 #define _NETINET_TCP_VAR_H_
37 
38 #include <netinet/tcp.h>
39 #include <netinet/tcp_fsm.h>
40 
41 #ifdef _KERNEL
42 #include <net/vnet.h>
43 #include <sys/mbuf.h>
44 #endif
45 
46 #if defined(_KERNEL) || defined(_WANT_TCPCB)
47 /* TCP segment queue entry */
48 struct tseg_qent {
49 	TAILQ_ENTRY(tseg_qent) tqe_q;
50 	struct	mbuf   *tqe_m;		/* mbuf contains packet */
51 	struct  mbuf   *tqe_last;	/* last mbuf in chain */
52 	tcp_seq tqe_start;		/* TCP Sequence number start */
53 	int	tqe_len;		/* TCP segment data length */
54 	uint32_t tqe_flags;		/* The flags from the th->th_flags */
55 	uint32_t tqe_mbuf_cnt;		/* Count of mbuf overhead */
56 };
57 TAILQ_HEAD(tsegqe_head, tseg_qent);
58 
59 struct sackblk {
60 	tcp_seq start;		/* start seq no. of sack block */
61 	tcp_seq end;		/* end seq no. */
62 };
63 
64 struct sackhole {
65 	tcp_seq start;		/* start seq no. of hole */
66 	tcp_seq end;		/* end seq no. */
67 	tcp_seq rxmit;		/* next seq. no in hole to be retransmitted */
68 	TAILQ_ENTRY(sackhole) scblink;	/* scoreboard linkage */
69 };
70 
71 struct sackhint {
72 	struct sackhole	*nexthole;
73 	int		sack_bytes_rexmit;
74 	tcp_seq		last_sack_ack;	/* Most recent/largest sacked ack */
75 
76 	int		ispare;		/* explicit pad for 64bit alignment */
77 	int             sacked_bytes;	/*
78 					 * Total sacked bytes reported by the
79 					 * receiver via sack option
80 					 */
81 	uint32_t	_pad1[1];	/* TBD */
82 	uint64_t	_pad[1];	/* TBD */
83 };
84 
85 #define SEGQ_EMPTY(tp) TAILQ_EMPTY(&(tp)->t_segq)
86 
87 STAILQ_HEAD(tcp_log_stailq, tcp_log_mem);
88 
89 /*
90  * Tcp control block, one per tcp; fields:
91  * Organized for 64 byte cacheline efficiency based
92  * on common tcp_input/tcp_output processing.
93  */
94 struct tcpcb {
95 	/* Cache line 1 */
96 	struct	inpcb *t_inpcb;		/* back pointer to internet pcb */
97 	struct tcp_function_block *t_fb;/* TCP function call block */
98 	void	*t_fb_ptr;		/* Pointer to t_fb specific data */
99 	uint32_t t_maxseg:24,		/* maximum segment size */
100 		t_logstate:8;		/* State of "black box" logging */
101 	uint32_t t_port:16,		/* Tunneling (over udp) port */
102 		t_state:4,		/* state of this connection */
103 		t_idle_reduce : 1,
104 		t_delayed_ack: 7,	/* Delayed ack variable */
105 		t_fin_is_rst: 1,	/* Are fin's treated as resets */
106 		bits_spare : 3;
107 	u_int	t_flags;
108 	tcp_seq	snd_una;		/* sent but unacknowledged */
109 	tcp_seq	snd_max;		/* highest sequence number sent;
110 					 * used to recognize retransmits
111 					 */
112 	tcp_seq	snd_nxt;		/* send next */
113 	tcp_seq	snd_up;			/* send urgent pointer */
114 	uint32_t  snd_wnd;		/* send window */
115 	uint32_t  snd_cwnd;		/* congestion-controlled window */
116 	uint32_t t_peakrate_thr; 	/* pre-calculated peak rate threshold */
117 	/* Cache line 2 */
118 	u_int32_t  ts_offset;		/* our timestamp offset */
119 	u_int32_t	rfbuf_ts;	/* recv buffer autoscaling timestamp */
120 	int	rcv_numsacks;		/* # distinct sack blks present */
121 	u_int	t_tsomax;		/* TSO total burst length limit in bytes */
122 	u_int	t_tsomaxsegcount;	/* TSO maximum segment count */
123 	u_int	t_tsomaxsegsize;	/* TSO maximum segment size in bytes */
124 	tcp_seq	rcv_nxt;		/* receive next */
125 	tcp_seq	rcv_adv;		/* advertised window */
126 	uint32_t  rcv_wnd;		/* receive window */
127 	u_int	t_flags2;		/* More tcpcb flags storage */
128 	int	t_srtt;			/* smoothed round-trip time */
129 	int	t_rttvar;		/* variance in round-trip time */
130 	u_int32_t  ts_recent;		/* timestamp echo data */
131 	u_char	snd_scale;		/* window scaling for send window */
132 	u_char	rcv_scale;		/* window scaling for recv window */
133 	u_char	snd_limited;		/* segments limited transmitted */
134 	u_char	request_r_scale;	/* pending window scaling */
135 	tcp_seq	last_ack_sent;
136 	u_int	t_rcvtime;		/* inactivity time */
137 	/* Cache line 3 */
138 	tcp_seq	rcv_up;			/* receive urgent pointer */
139 	int	t_segqlen;		/* segment reassembly queue length */
140 	uint32_t t_segqmbuflen;		/* Count of bytes mbufs on all entries */
141 	struct	tsegqe_head t_segq;	/* segment reassembly queue */
142 	struct mbuf      *t_in_pkt;
143 	struct mbuf	 *t_tail_pkt;
144 	struct tcp_timer *t_timers;	/* All the TCP timers in one struct */
145 	struct	vnet *t_vnet;		/* back pointer to parent vnet */
146 	uint32_t  snd_ssthresh;		/* snd_cwnd size threshold for
147 					 * for slow start exponential to
148 					 * linear switch
149 					 */
150 	tcp_seq	snd_wl1;		/* window update seg seq number */
151 	/* Cache line 4 */
152 	tcp_seq	snd_wl2;		/* window update seg ack number */
153 
154 	tcp_seq	irs;			/* initial receive sequence number */
155 	tcp_seq	iss;		        /* initial send sequence number */
156 	u_int   t_acktime;
157 	u_int	ts_recent_age;		/* when last updated */
158 	tcp_seq	snd_recover;		/* for use in NewReno Fast Recovery */
159 	uint16_t cl4_spare;		/* Spare to adjust CL 4 */
160 	char	t_oobflags;		/* have some */
161 	char	t_iobc;			/* input character */
162 	int	t_rxtcur;		/* current retransmit value (ticks) */
163 
164 	int	t_rxtshift;		/* log(2) of rexmt exp. backoff */
165 	u_int	t_rtttime;		/* RTT measurement start time */
166 
167 	tcp_seq	t_rtseq;		/* sequence number being timed */
168 	u_int	t_starttime;		/* time connection was established */
169 
170 	u_int	t_pmtud_saved_maxseg;	/* pre-blackhole MSS */
171 	u_int	t_rttmin;		/* minimum rtt allowed */
172 
173 	u_int	t_rttbest;		/* best rtt we've seen */
174 
175 	int	t_softerror;		/* possible error not yet reported */
176 	uint32_t  max_sndwnd;		/* largest window peer has offered */
177 	/* Cache line 5 */
178 	uint32_t  snd_cwnd_prev;	/* cwnd prior to retransmit */
179 	uint32_t  snd_ssthresh_prev;	/* ssthresh prior to retransmit */
180 	tcp_seq	snd_recover_prev;	/* snd_recover prior to retransmit */
181 	int	t_sndzerowin;		/* zero-window updates sent */
182 	u_long	t_rttupdated;		/* number of times rtt sampled */
183 	int	snd_numholes;		/* number of holes seen by sender */
184 	u_int	t_badrxtwin;		/* window for retransmit recovery */
185 	TAILQ_HEAD(sackhole_head, sackhole) snd_holes;
186 					/* SACK scoreboard (sorted) */
187 	tcp_seq	snd_fack;		/* last seq number(+1) sack'd by rcv'r*/
188 	tcp_seq sack_newdata;		/* New data xmitted in this recovery
189 					   episode starts at this seq number */
190 	struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
191 	struct sackhint	sackhint;	/* SACK scoreboard hint */
192 	int	t_rttlow;		/* smallest observerved RTT */
193 	int	rfbuf_cnt;		/* recv buffer autoscaling byte count */
194 	struct toedev	*tod;		/* toedev handling this connection */
195 	int	t_sndrexmitpack;	/* retransmit packets sent */
196 	int	t_rcvoopack;		/* out-of-order packets received */
197 	void	*t_toe;			/* TOE pcb pointer */
198 	struct cc_algo	*cc_algo;	/* congestion control algorithm */
199 	struct cc_var	*ccv;		/* congestion control specific vars */
200 	struct osd	*osd;		/* storage for Khelp module data */
201 	int	t_bytes_acked;		/* # bytes acked during current RTT */
202 	u_int   t_maxunacktime;
203 	u_int	t_keepinit;		/* time to establish connection */
204 	u_int	t_keepidle;		/* time before keepalive probes begin */
205 	u_int	t_keepintvl;		/* interval between keepalives */
206 	u_int	t_keepcnt;		/* number of keepalives before close */
207 	int	t_dupacks;		/* consecutive dup acks recd */
208 	int	t_lognum;		/* Number of log entries */
209 	struct tcp_log_stailq t_logs;	/* Log buffer */
210 	struct tcp_log_id_node *t_lin;
211 	struct tcp_log_id_bucket *t_lib;
212 	const char *t_output_caller;	/* Function that called tcp_output */
213 	uint32_t t_logsn;		/* Log "serial number" */
214 	uint8_t t_tfo_client_cookie_len; /* TCP Fast Open client cookie length */
215 	unsigned int *t_tfo_pending;	/* TCP Fast Open server pending counter */
216 	union {
217 		uint8_t client[TCP_FASTOPEN_MAX_COOKIE_LEN];
218 		uint64_t server;
219 	} t_tfo_cookie;			/* TCP Fast Open cookie to send */
220 #ifdef TCPPCAP
221 	struct mbufq t_inpkts;		/* List of saved input packets. */
222 	struct mbufq t_outpkts;		/* List of saved output packets. */
223 #endif
224 };
225 #endif	/* _KERNEL || _WANT_TCPCB */
226 
227 #ifdef _KERNEL
228 struct tcptemp {
229 	u_char	tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
230 	struct	tcphdr tt_t;
231 };
232 
233 /*
234  * TODO: We yet need to brave plowing in
235  * to tcp_input() and the pru_usrreq() block.
236  * Right now these go to the old standards which
237  * are somewhat ok, but in the long term may
238  * need to be changed. If we do tackle tcp_input()
239  * then we need to get rid of the tcp_do_segment()
240  * function below.
241  */
242 /* Flags for tcp functions */
243 #define TCP_FUNC_BEING_REMOVED 0x01   	/* Can no longer be referenced */
244 
245 /*
246  * If defining the optional tcp_timers, in the
247  * tfb_tcp_timer_stop call you must use the
248  * callout_async_drain() function with the
249  * tcp_timer_discard callback. You should check
250  * the return of callout_async_drain() and if 0
251  * increment tt_draincnt. Since the timer sub-system
252  * does not know your callbacks you must provide a
253  * stop_all function that loops through and calls
254  * tcp_timer_stop() with each of your defined timers.
255  * Adding a tfb_tcp_handoff_ok function allows the socket
256  * option to change stacks to query you even if the
257  * connection is in a later stage. You return 0 to
258  * say you can take over and run your stack, you return
259  * non-zero (an error number) to say no you can't.
260  * If the function is undefined you can only change
261  * in the early states (before connect or listen).
262  * tfb_tcp_fb_fini is changed to add a flag to tell
263  * the old stack if the tcb is being destroyed or
264  * not. A one in the flag means the TCB is being
265  * destroyed, a zero indicates its transitioning to
266  * another stack (via socket option).
267  */
268 struct tcp_function_block {
269 	char tfb_tcp_block_name[TCP_FUNCTION_NAME_LEN_MAX];
270 	int	(*tfb_tcp_output)(struct tcpcb *);
271 	int	(*tfb_tcp_output_wtime)(struct tcpcb *, const struct timeval *);
272 	void	(*tfb_tcp_do_segment)(struct mbuf *, struct tcphdr *,
273 			    struct socket *, struct tcpcb *,
274 		        int, int, uint8_t);
275 	int     (*tfb_do_queued_segments)(struct socket *, struct tcpcb *, int);
276 	int      (*tfb_do_segment_nounlock)(struct mbuf *, struct tcphdr *,
277 			    struct socket *, struct tcpcb *,
278 			    int, int, uint8_t,
279 			    int, struct timeval *);
280 	void	(*tfb_tcp_hpts_do_segment)(struct mbuf *, struct tcphdr *,
281 			    struct socket *, struct tcpcb *,
282 			    int, int, uint8_t,
283 			    int, struct timeval *);
284 	int     (*tfb_tcp_ctloutput)(struct socket *so, struct sockopt *sopt,
285 			    struct inpcb *inp, struct tcpcb *tp);
286 	/* Optional memory allocation/free routine */
287 	int	(*tfb_tcp_fb_init)(struct tcpcb *);
288 	void	(*tfb_tcp_fb_fini)(struct tcpcb *, int);
289 	/* Optional timers, must define all if you define one */
290 	int	(*tfb_tcp_timer_stop_all)(struct tcpcb *);
291 	void	(*tfb_tcp_timer_activate)(struct tcpcb *,
292 			    uint32_t, u_int);
293 	int	(*tfb_tcp_timer_active)(struct tcpcb *, uint32_t);
294 	void	(*tfb_tcp_timer_stop)(struct tcpcb *, uint32_t);
295 	void	(*tfb_tcp_rexmit_tmr)(struct tcpcb *);
296 	int	(*tfb_tcp_handoff_ok)(struct tcpcb *);
297 	void	(*tfb_tcp_mtu_chg)(struct tcpcb *);
298 	volatile uint32_t tfb_refcnt;
299 	uint32_t  tfb_flags;
300 	uint8_t	tfb_id;
301 };
302 
303 struct tcp_function {
304 	TAILQ_ENTRY(tcp_function)	tf_next;
305 	char				tf_name[TCP_FUNCTION_NAME_LEN_MAX];
306 	struct tcp_function_block	*tf_fb;
307 };
308 
309 TAILQ_HEAD(tcp_funchead, tcp_function);
310 #endif	/* _KERNEL */
311 
312 /*
313  * Flags and utility macros for the t_flags field.
314  */
315 #define	TF_ACKNOW	0x000001	/* ack peer immediately */
316 #define	TF_DELACK	0x000002	/* ack, but try to delay it */
317 #define	TF_NODELAY	0x000004	/* don't delay packets to coalesce */
318 #define	TF_NOOPT	0x000008	/* don't use tcp options */
319 #define	TF_SENTFIN	0x000010	/* have sent FIN */
320 #define	TF_REQ_SCALE	0x000020	/* have/will request window scaling */
321 #define	TF_RCVD_SCALE	0x000040	/* other side has requested scaling */
322 #define	TF_REQ_TSTMP	0x000080	/* have/will request timestamps */
323 #define	TF_RCVD_TSTMP	0x000100	/* a timestamp was received in SYN */
324 #define	TF_SACK_PERMIT	0x000200	/* other side said I could SACK */
325 #define	TF_NEEDSYN	0x000400	/* send SYN (implicit state) */
326 #define	TF_NEEDFIN	0x000800	/* send FIN (implicit state) */
327 #define	TF_NOPUSH	0x001000	/* don't push */
328 #define	TF_PREVVALID	0x002000	/* saved values for bad rxmit valid */
329 #define	TF_MORETOCOME	0x010000	/* More data to be appended to sock */
330 #define	TF_LQ_OVERFLOW	0x020000	/* listen queue overflow */
331 #define	TF_LASTIDLE	0x040000	/* connection was previously idle */
332 #define	TF_RXWIN0SENT	0x080000	/* sent a receiver win 0 in response */
333 #define	TF_FASTRECOVERY	0x100000	/* in NewReno Fast Recovery */
334 #define	TF_WASFRECOVERY	0x200000	/* was in NewReno Fast Recovery */
335 #define	TF_SIGNATURE	0x400000	/* require MD5 digests (RFC2385) */
336 #define	TF_FORCEDATA	0x800000	/* force out a byte */
337 #define	TF_TSO		0x1000000	/* TSO enabled on this connection */
338 #define	TF_TOE		0x2000000	/* this connection is offloaded */
339 #define	TF_ECN_PERMIT	0x4000000	/* connection ECN-ready */
340 #define	TF_ECN_SND_CWR	0x8000000	/* ECN CWR in queue */
341 #define	TF_ECN_SND_ECE	0x10000000	/* ECN ECE in queue */
342 #define	TF_CONGRECOVERY	0x20000000	/* congestion recovery mode */
343 #define	TF_WASCRECOVERY	0x40000000	/* was in congestion recovery */
344 #define	TF_FASTOPEN	0x80000000	/* TCP Fast Open indication */
345 
346 #define	IN_FASTRECOVERY(t_flags)	(t_flags & TF_FASTRECOVERY)
347 #define	ENTER_FASTRECOVERY(t_flags)	t_flags |= TF_FASTRECOVERY
348 #define	EXIT_FASTRECOVERY(t_flags)	t_flags &= ~TF_FASTRECOVERY
349 
350 #define	IN_CONGRECOVERY(t_flags)	(t_flags & TF_CONGRECOVERY)
351 #define	ENTER_CONGRECOVERY(t_flags)	t_flags |= TF_CONGRECOVERY
352 #define	EXIT_CONGRECOVERY(t_flags)	t_flags &= ~TF_CONGRECOVERY
353 
354 #define	IN_RECOVERY(t_flags) (t_flags & (TF_CONGRECOVERY | TF_FASTRECOVERY))
355 #define	ENTER_RECOVERY(t_flags) t_flags |= (TF_CONGRECOVERY | TF_FASTRECOVERY)
356 #define	EXIT_RECOVERY(t_flags) t_flags &= ~(TF_CONGRECOVERY | TF_FASTRECOVERY)
357 
358 #if defined(_KERNEL) && !defined(TCP_RFC7413)
359 #define	IS_FASTOPEN(t_flags)		(false)
360 #else
361 #define	IS_FASTOPEN(t_flags)		(t_flags & TF_FASTOPEN)
362 #endif
363 
364 #define	BYTES_THIS_ACK(tp, th)	(th->th_ack - tp->snd_una)
365 
366 /*
367  * Flags for the t_oobflags field.
368  */
369 #define	TCPOOB_HAVEDATA	0x01
370 #define	TCPOOB_HADDATA	0x02
371 
372 /*
373  * Flags for the extended TCP flags field, t_flags2
374  */
375 #define	TF2_PLPMTU_BLACKHOLE	0x00000001 /* Possible PLPMTUD Black Hole. */
376 #define	TF2_PLPMTU_PMTUD	0x00000002 /* Allowed to attempt PLPMTUD. */
377 #define	TF2_PLPMTU_MAXSEGSNT	0x00000004 /* Last seg sent was full seg. */
378 #define	TF2_LOG_AUTO		0x00000008 /* Session is auto-logging. */
379 #define TF2_DROP_AF_DATA 	0x00000010 /* Drop after all data ack'd */
380 
381 /*
382  * Structure to hold TCP options that are only used during segment
383  * processing (in tcp_input), but not held in the tcpcb.
384  * It's basically used to reduce the number of parameters
385  * to tcp_dooptions and tcp_addoptions.
386  * The binary order of the to_flags is relevant for packing of the
387  * options in tcp_addoptions.
388  */
389 struct tcpopt {
390 	u_int32_t	to_flags;	/* which options are present */
391 #define	TOF_MSS		0x0001		/* maximum segment size */
392 #define	TOF_SCALE	0x0002		/* window scaling */
393 #define	TOF_SACKPERM	0x0004		/* SACK permitted */
394 #define	TOF_TS		0x0010		/* timestamp */
395 #define	TOF_SIGNATURE	0x0040		/* TCP-MD5 signature option (RFC2385) */
396 #define	TOF_SACK	0x0080		/* Peer sent SACK option */
397 #define	TOF_FASTOPEN	0x0100		/* TCP Fast Open (TFO) cookie */
398 #define	TOF_MAXOPT	0x0200
399 	u_int32_t	to_tsval;	/* new timestamp */
400 	u_int32_t	to_tsecr;	/* reflected timestamp */
401 	u_char		*to_sacks;	/* pointer to the first SACK blocks */
402 	u_char		*to_signature;	/* pointer to the TCP-MD5 signature */
403 	u_int8_t	*to_tfo_cookie; /* pointer to the TFO cookie */
404 	u_int16_t	to_mss;		/* maximum segment size */
405 	u_int8_t	to_wscale;	/* window scaling */
406 	u_int8_t	to_nsacks;	/* number of SACK blocks */
407 	u_int8_t	to_tfo_len;	/* TFO cookie length */
408 	u_int32_t	to_spare;	/* UTO */
409 };
410 
411 /*
412  * Flags for tcp_dooptions.
413  */
414 #define	TO_SYN		0x01		/* parse SYN-only options */
415 
416 struct hc_metrics_lite {	/* must stay in sync with hc_metrics */
417 	uint32_t	rmx_mtu;	/* MTU for this path */
418 	uint32_t	rmx_ssthresh;	/* outbound gateway buffer limit */
419 	uint32_t	rmx_rtt;	/* estimated round trip time */
420 	uint32_t	rmx_rttvar;	/* estimated rtt variance */
421 	uint32_t	rmx_cwnd;	/* congestion window */
422 	uint32_t	rmx_sendpipe;   /* outbound delay-bandwidth product */
423 	uint32_t	rmx_recvpipe;   /* inbound delay-bandwidth product */
424 };
425 
426 /*
427  * Used by tcp_maxmtu() to communicate interface specific features
428  * and limits at the time of connection setup.
429  */
430 struct tcp_ifcap {
431 	int	ifcap;
432 	u_int	tsomax;
433 	u_int	tsomaxsegcount;
434 	u_int	tsomaxsegsize;
435 };
436 
437 #ifndef _NETINET_IN_PCB_H_
438 struct in_conninfo;
439 #endif /* _NETINET_IN_PCB_H_ */
440 
441 struct tcptw {
442 	struct inpcb	*tw_inpcb;	/* XXX back pointer to internet pcb */
443 	tcp_seq		snd_nxt;
444 	tcp_seq		rcv_nxt;
445 	tcp_seq		iss;
446 	tcp_seq		irs;
447 	u_short		last_win;	/* cached window value */
448 	short		tw_so_options;	/* copy of so_options */
449 	struct ucred	*tw_cred;	/* user credentials */
450 	u_int32_t	t_recent;
451 	u_int32_t	ts_offset;	/* our timestamp offset */
452 	u_int		t_starttime;
453 	int		tw_time;
454 	TAILQ_ENTRY(tcptw) tw_2msl;
455 	void		*tw_pspare;	/* TCP_SIGNATURE */
456 	u_int		*tw_spare;	/* TCP_SIGNATURE */
457 };
458 
459 #define	intotcpcb(ip)	((struct tcpcb *)(ip)->inp_ppcb)
460 #define	intotw(ip)	((struct tcptw *)(ip)->inp_ppcb)
461 #define	sototcpcb(so)	(intotcpcb(sotoinpcb(so)))
462 
463 /*
464  * The smoothed round-trip time and estimated variance
465  * are stored as fixed point numbers scaled by the values below.
466  * For convenience, these scales are also used in smoothing the average
467  * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
468  * With these scales, srtt has 3 bits to the right of the binary point,
469  * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
470  * binary point, and is smoothed with an ALPHA of 0.75.
471  */
472 #define	TCP_RTT_SCALE		32	/* multiplier for srtt; 3 bits frac. */
473 #define	TCP_RTT_SHIFT		5	/* shift for srtt; 3 bits frac. */
474 #define	TCP_RTTVAR_SCALE	16	/* multiplier for rttvar; 2 bits */
475 #define	TCP_RTTVAR_SHIFT	4	/* shift for rttvar; 2 bits */
476 #define	TCP_DELTA_SHIFT		2	/* see tcp_input.c */
477 
478 /*
479  * The initial retransmission should happen at rtt + 4 * rttvar.
480  * Because of the way we do the smoothing, srtt and rttvar
481  * will each average +1/2 tick of bias.  When we compute
482  * the retransmit timer, we want 1/2 tick of rounding and
483  * 1 extra tick because of +-1/2 tick uncertainty in the
484  * firing of the timer.  The bias will give us exactly the
485  * 1.5 tick we need.  But, because the bias is
486  * statistical, we have to test that we don't drop below
487  * the minimum feasible timer (which is 2 ticks).
488  * This version of the macro adapted from a paper by Lawrence
489  * Brakmo and Larry Peterson which outlines a problem caused
490  * by insufficient precision in the original implementation,
491  * which results in inappropriately large RTO values for very
492  * fast networks.
493  */
494 #define	TCP_REXMTVAL(tp) \
495 	max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
496 	  + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
497 
498 /*
499  * TCP statistics.
500  * Many of these should be kept per connection,
501  * but that's inconvenient at the moment.
502  */
503 struct	tcpstat {
504 	uint64_t tcps_connattempt;	/* connections initiated */
505 	uint64_t tcps_accepts;		/* connections accepted */
506 	uint64_t tcps_connects;		/* connections established */
507 	uint64_t tcps_drops;		/* connections dropped */
508 	uint64_t tcps_conndrops;	/* embryonic connections dropped */
509 	uint64_t tcps_minmssdrops;	/* average minmss too low drops */
510 	uint64_t tcps_closed;		/* conn. closed (includes drops) */
511 	uint64_t tcps_segstimed;	/* segs where we tried to get rtt */
512 	uint64_t tcps_rttupdated;	/* times we succeeded */
513 	uint64_t tcps_delack;		/* delayed acks sent */
514 	uint64_t tcps_timeoutdrop;	/* conn. dropped in rxmt timeout */
515 	uint64_t tcps_rexmttimeo;	/* retransmit timeouts */
516 	uint64_t tcps_persisttimeo;	/* persist timeouts */
517 	uint64_t tcps_keeptimeo;	/* keepalive timeouts */
518 	uint64_t tcps_keepprobe;	/* keepalive probes sent */
519 	uint64_t tcps_keepdrops;	/* connections dropped in keepalive */
520 
521 	uint64_t tcps_sndtotal;		/* total packets sent */
522 	uint64_t tcps_sndpack;		/* data packets sent */
523 	uint64_t tcps_sndbyte;		/* data bytes sent */
524 	uint64_t tcps_sndrexmitpack;	/* data packets retransmitted */
525 	uint64_t tcps_sndrexmitbyte;	/* data bytes retransmitted */
526 	uint64_t tcps_sndrexmitbad;	/* unnecessary packet retransmissions */
527 	uint64_t tcps_sndacks;		/* ack-only packets sent */
528 	uint64_t tcps_sndprobe;		/* window probes sent */
529 	uint64_t tcps_sndurg;		/* packets sent with URG only */
530 	uint64_t tcps_sndwinup;		/* window update-only packets sent */
531 	uint64_t tcps_sndctrl;		/* control (SYN|FIN|RST) packets sent */
532 
533 	uint64_t tcps_rcvtotal;		/* total packets received */
534 	uint64_t tcps_rcvpack;		/* packets received in sequence */
535 	uint64_t tcps_rcvbyte;		/* bytes received in sequence */
536 	uint64_t tcps_rcvbadsum;	/* packets received with ccksum errs */
537 	uint64_t tcps_rcvbadoff;	/* packets received with bad offset */
538 	uint64_t tcps_rcvreassfull;	/* packets dropped for no reass space */
539 	uint64_t tcps_rcvshort;		/* packets received too short */
540 	uint64_t tcps_rcvduppack;	/* duplicate-only packets received */
541 	uint64_t tcps_rcvdupbyte;	/* duplicate-only bytes received */
542 	uint64_t tcps_rcvpartduppack;	/* packets with some duplicate data */
543 	uint64_t tcps_rcvpartdupbyte;	/* dup. bytes in part-dup. packets */
544 	uint64_t tcps_rcvoopack;	/* out-of-order packets received */
545 	uint64_t tcps_rcvoobyte;	/* out-of-order bytes received */
546 	uint64_t tcps_rcvpackafterwin;	/* packets with data after window */
547 	uint64_t tcps_rcvbyteafterwin;	/* bytes rcvd after window */
548 	uint64_t tcps_rcvafterclose;	/* packets rcvd after "close" */
549 	uint64_t tcps_rcvwinprobe;	/* rcvd window probe packets */
550 	uint64_t tcps_rcvdupack;	/* rcvd duplicate acks */
551 	uint64_t tcps_rcvacktoomuch;	/* rcvd acks for unsent data */
552 	uint64_t tcps_rcvackpack;	/* rcvd ack packets */
553 	uint64_t tcps_rcvackbyte;	/* bytes acked by rcvd acks */
554 	uint64_t tcps_rcvwinupd;	/* rcvd window update packets */
555 	uint64_t tcps_pawsdrop;		/* segments dropped due to PAWS */
556 	uint64_t tcps_predack;		/* times hdr predict ok for acks */
557 	uint64_t tcps_preddat;		/* times hdr predict ok for data pkts */
558 	uint64_t tcps_pcbcachemiss;
559 	uint64_t tcps_cachedrtt;	/* times cached RTT in route updated */
560 	uint64_t tcps_cachedrttvar;	/* times cached rttvar updated */
561 	uint64_t tcps_cachedssthresh;	/* times cached ssthresh updated */
562 	uint64_t tcps_usedrtt;		/* times RTT initialized from route */
563 	uint64_t tcps_usedrttvar;	/* times RTTVAR initialized from rt */
564 	uint64_t tcps_usedssthresh;	/* times ssthresh initialized from rt*/
565 	uint64_t tcps_persistdrop;	/* timeout in persist state */
566 	uint64_t tcps_badsyn;		/* bogus SYN, e.g. premature ACK */
567 	uint64_t tcps_mturesent;	/* resends due to MTU discovery */
568 	uint64_t tcps_listendrop;	/* listen queue overflows */
569 	uint64_t tcps_badrst;		/* ignored RSTs in the window */
570 
571 	uint64_t tcps_sc_added;		/* entry added to syncache */
572 	uint64_t tcps_sc_retransmitted;	/* syncache entry was retransmitted */
573 	uint64_t tcps_sc_dupsyn;	/* duplicate SYN packet */
574 	uint64_t tcps_sc_dropped;	/* could not reply to packet */
575 	uint64_t tcps_sc_completed;	/* successful extraction of entry */
576 	uint64_t tcps_sc_bucketoverflow;/* syncache per-bucket limit hit */
577 	uint64_t tcps_sc_cacheoverflow;	/* syncache cache limit hit */
578 	uint64_t tcps_sc_reset;		/* RST removed entry from syncache */
579 	uint64_t tcps_sc_stale;		/* timed out or listen socket gone */
580 	uint64_t tcps_sc_aborted;	/* syncache entry aborted */
581 	uint64_t tcps_sc_badack;	/* removed due to bad ACK */
582 	uint64_t tcps_sc_unreach;	/* ICMP unreachable received */
583 	uint64_t tcps_sc_zonefail;	/* zalloc() failed */
584 	uint64_t tcps_sc_sendcookie;	/* SYN cookie sent */
585 	uint64_t tcps_sc_recvcookie;	/* SYN cookie received */
586 
587 	uint64_t tcps_hc_added;		/* entry added to hostcache */
588 	uint64_t tcps_hc_bucketoverflow;/* hostcache per bucket limit hit */
589 
590 	uint64_t tcps_finwait2_drops;    /* Drop FIN_WAIT_2 connection after time limit */
591 
592 	/* SACK related stats */
593 	uint64_t tcps_sack_recovery_episode; /* SACK recovery episodes */
594 	uint64_t tcps_sack_rexmits;	    /* SACK rexmit segments   */
595 	uint64_t tcps_sack_rexmit_bytes;    /* SACK rexmit bytes      */
596 	uint64_t tcps_sack_rcv_blocks;	    /* SACK blocks (options) received */
597 	uint64_t tcps_sack_send_blocks;	    /* SACK blocks (options) sent     */
598 	uint64_t tcps_sack_sboverflow;	    /* times scoreboard overflowed */
599 
600 	/* ECN related stats */
601 	uint64_t tcps_ecn_ce;		/* ECN Congestion Experienced */
602 	uint64_t tcps_ecn_ect0;		/* ECN Capable Transport */
603 	uint64_t tcps_ecn_ect1;		/* ECN Capable Transport */
604 	uint64_t tcps_ecn_shs;		/* ECN successful handshakes */
605 	uint64_t tcps_ecn_rcwnd;	/* # times ECN reduced the cwnd */
606 
607 	/* TCP_SIGNATURE related stats */
608 	uint64_t tcps_sig_rcvgoodsig;	/* Total matching signature received */
609 	uint64_t tcps_sig_rcvbadsig;	/* Total bad signature received */
610 	uint64_t tcps_sig_err_buildsig;	/* Failed to make signature */
611 	uint64_t tcps_sig_err_sigopt;	/* No signature expected by socket */
612 	uint64_t tcps_sig_err_nosigopt;	/* No signature provided by segment */
613 
614 	/* Path MTU Discovery Black Hole Detection related stats */
615 	uint64_t tcps_pmtud_blackhole_activated;	 /* Black Hole Count */
616 	uint64_t tcps_pmtud_blackhole_activated_min_mss; /* BH at min MSS Count */
617 	uint64_t tcps_pmtud_blackhole_failed;		 /* Black Hole Failure Count */
618 
619 	uint64_t _pad[12];		/* 6 UTO, 6 TBD */
620 };
621 
622 #define	tcps_rcvmemdrop	tcps_rcvreassfull	/* compat */
623 
624 #ifdef _KERNEL
625 #define	TI_UNLOCKED	1
626 #define	TI_RLOCKED	2
627 #include <sys/counter.h>
628 
629 VNET_PCPUSTAT_DECLARE(struct tcpstat, tcpstat);	/* tcp statistics */
630 /*
631  * In-kernel consumers can use these accessor macros directly to update
632  * stats.
633  */
634 #define	TCPSTAT_ADD(name, val)	\
635     VNET_PCPUSTAT_ADD(struct tcpstat, tcpstat, name, (val))
636 #define	TCPSTAT_INC(name)	TCPSTAT_ADD(name, 1)
637 
638 /*
639  * Kernel module consumers must use this accessor macro.
640  */
641 void	kmod_tcpstat_inc(int statnum);
642 #define	KMOD_TCPSTAT_INC(name)						\
643     kmod_tcpstat_inc(offsetof(struct tcpstat, name) / sizeof(uint64_t))
644 
645 /*
646  * Running TCP connection count by state.
647  */
648 VNET_DECLARE(counter_u64_t, tcps_states[TCP_NSTATES]);
649 #define	V_tcps_states	VNET(tcps_states)
650 #define	TCPSTATES_INC(state)	counter_u64_add(V_tcps_states[state], 1)
651 #define	TCPSTATES_DEC(state)	counter_u64_add(V_tcps_states[state], -1)
652 
653 /*
654  * TCP specific helper hook point identifiers.
655  */
656 #define	HHOOK_TCP_EST_IN		0
657 #define	HHOOK_TCP_EST_OUT		1
658 #define	HHOOK_TCP_LAST			HHOOK_TCP_EST_OUT
659 
660 struct tcp_hhook_data {
661 	struct tcpcb	*tp;
662 	struct tcphdr	*th;
663 	struct tcpopt	*to;
664 	uint32_t	len;
665 	int		tso;
666 	tcp_seq		curack;
667 };
668 #ifdef TCP_HHOOK
669 void hhook_run_tcp_est_out(struct tcpcb *tp,
670 	struct tcphdr *th, struct tcpopt *to,
671 	uint32_t len, int tso);
672 #endif
673 #endif
674 
675 /*
676  * TCB structure exported to user-land via sysctl(3).
677  *
678  * Fields prefixed with "xt_" are unique to the export structure, and fields
679  * with "t_" or other prefixes match corresponding fields of 'struct tcpcb'.
680  *
681  * Legend:
682  * (s) - used by userland utilities in src
683  * (p) - used by utilities in ports
684  * (3) - is known to be used by third party software not in ports
685  * (n) - no known usage
686  *
687  * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
688  * included.  Not all of our clients do.
689  */
690 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
691 struct xtcpcb {
692 	ksize_t	xt_len;		/* length of this structure */
693 	struct xinpcb	xt_inp;
694 	char		xt_stack[TCP_FUNCTION_NAME_LEN_MAX];	/* (s) */
695 	char		xt_logid[TCP_LOG_ID_LEN];	/* (s) */
696 	int64_t		spare64[8];
697 	int32_t		t_state;		/* (s,p) */
698 	uint32_t	t_flags;		/* (s,p) */
699 	int32_t		t_sndzerowin;		/* (s) */
700 	int32_t		t_sndrexmitpack;	/* (s) */
701 	int32_t		t_rcvoopack;		/* (s) */
702 	int32_t		t_rcvtime;		/* (s) */
703 	int32_t		tt_rexmt;		/* (s) */
704 	int32_t		tt_persist;		/* (s) */
705 	int32_t		tt_keep;		/* (s) */
706 	int32_t		tt_2msl;		/* (s) */
707 	int32_t		tt_delack;		/* (s) */
708 	int32_t		t_logstate;		/* (3) */
709 	int32_t		spare32[32];
710 } __aligned(8);
711 
712 #ifdef _KERNEL
713 void	tcp_inptoxtp(const struct inpcb *, struct xtcpcb *);
714 #endif
715 #endif
716 
717 /*
718  * TCP function information (name-to-id mapping, aliases, and refcnt)
719  * exported to user-land via sysctl(3).
720  */
721 struct tcp_function_info {
722 	uint32_t	tfi_refcnt;
723 	uint8_t		tfi_id;
724 	char		tfi_name[TCP_FUNCTION_NAME_LEN_MAX];
725 	char		tfi_alias[TCP_FUNCTION_NAME_LEN_MAX];
726 };
727 
728 /*
729  * Identifiers for TCP sysctl nodes
730  */
731 #define	TCPCTL_DO_RFC1323	1	/* use RFC-1323 extensions */
732 #define	TCPCTL_MSSDFLT		3	/* MSS default */
733 #define TCPCTL_STATS		4	/* statistics */
734 #define	TCPCTL_RTTDFLT		5	/* default RTT estimate */
735 #define	TCPCTL_KEEPIDLE		6	/* keepalive idle timer */
736 #define	TCPCTL_KEEPINTVL	7	/* interval to send keepalives */
737 #define	TCPCTL_SENDSPACE	8	/* send buffer space */
738 #define	TCPCTL_RECVSPACE	9	/* receive buffer space */
739 #define	TCPCTL_KEEPINIT		10	/* timeout for establishing syn */
740 #define	TCPCTL_PCBLIST		11	/* list of all outstanding PCBs */
741 #define	TCPCTL_DELACKTIME	12	/* time before sending delayed ACK */
742 #define	TCPCTL_V6MSSDFLT	13	/* MSS default for IPv6 */
743 #define	TCPCTL_SACK		14	/* Selective Acknowledgement,rfc 2018 */
744 #define	TCPCTL_DROP		15	/* drop tcp connection */
745 #define	TCPCTL_STATES		16	/* connection counts by TCP state */
746 
747 #ifdef _KERNEL
748 #ifdef SYSCTL_DECL
749 SYSCTL_DECL(_net_inet_tcp);
750 SYSCTL_DECL(_net_inet_tcp_sack);
751 MALLOC_DECLARE(M_TCPLOG);
752 #endif
753 
754 extern	int tcp_log_in_vain;
755 
756 /*
757  * Global TCP tunables shared between different stacks.
758  * Please keep the list sorted.
759  */
760 VNET_DECLARE(int, drop_synfin);
761 VNET_DECLARE(int, path_mtu_discovery);
762 VNET_DECLARE(int, tcp_abc_l_var);
763 VNET_DECLARE(int, tcp_autorcvbuf_max);
764 VNET_DECLARE(int, tcp_autosndbuf_inc);
765 VNET_DECLARE(int, tcp_autosndbuf_max);
766 VNET_DECLARE(int, tcp_delack_enabled);
767 VNET_DECLARE(int, tcp_do_autorcvbuf);
768 VNET_DECLARE(int, tcp_do_autosndbuf);
769 VNET_DECLARE(int, tcp_do_ecn);
770 VNET_DECLARE(int, tcp_do_rfc1323);
771 VNET_DECLARE(int, tcp_do_rfc3042);
772 VNET_DECLARE(int, tcp_do_rfc3390);
773 VNET_DECLARE(int, tcp_do_rfc3465);
774 VNET_DECLARE(int, tcp_do_rfc6675_pipe);
775 VNET_DECLARE(int, tcp_do_sack);
776 VNET_DECLARE(int, tcp_do_tso);
777 VNET_DECLARE(int, tcp_ecn_maxretries);
778 VNET_DECLARE(int, tcp_initcwnd_segments);
779 VNET_DECLARE(int, tcp_insecure_rst);
780 VNET_DECLARE(int, tcp_insecure_syn);
781 VNET_DECLARE(int, tcp_minmss);
782 VNET_DECLARE(int, tcp_mssdflt);
783 VNET_DECLARE(int, tcp_recvspace);
784 VNET_DECLARE(int, tcp_sack_globalholes);
785 VNET_DECLARE(int, tcp_sack_globalmaxholes);
786 VNET_DECLARE(int, tcp_sack_maxholes);
787 VNET_DECLARE(int, tcp_sc_rst_sock_fail);
788 VNET_DECLARE(int, tcp_sendspace);
789 VNET_DECLARE(struct inpcbhead, tcb);
790 VNET_DECLARE(struct inpcbinfo, tcbinfo);
791 
792 #define	V_drop_synfin			VNET(drop_synfin)
793 #define	V_path_mtu_discovery		VNET(path_mtu_discovery)
794 #define	V_tcb				VNET(tcb)
795 #define	V_tcbinfo			VNET(tcbinfo)
796 #define	V_tcp_abc_l_var			VNET(tcp_abc_l_var)
797 #define	V_tcp_autorcvbuf_max		VNET(tcp_autorcvbuf_max)
798 #define	V_tcp_autosndbuf_inc		VNET(tcp_autosndbuf_inc)
799 #define	V_tcp_autosndbuf_max		VNET(tcp_autosndbuf_max)
800 #define	V_tcp_delack_enabled		VNET(tcp_delack_enabled)
801 #define	V_tcp_do_autorcvbuf		VNET(tcp_do_autorcvbuf)
802 #define	V_tcp_do_autosndbuf		VNET(tcp_do_autosndbuf)
803 #define	V_tcp_do_ecn			VNET(tcp_do_ecn)
804 #define	V_tcp_do_rfc1323		VNET(tcp_do_rfc1323)
805 #define V_tcp_ts_offset_per_conn	VNET(tcp_ts_offset_per_conn)
806 #define	V_tcp_do_rfc3042		VNET(tcp_do_rfc3042)
807 #define	V_tcp_do_rfc3390		VNET(tcp_do_rfc3390)
808 #define	V_tcp_do_rfc3465		VNET(tcp_do_rfc3465)
809 #define	V_tcp_do_rfc6675_pipe		VNET(tcp_do_rfc6675_pipe)
810 #define	V_tcp_do_sack			VNET(tcp_do_sack)
811 #define	V_tcp_do_tso			VNET(tcp_do_tso)
812 #define	V_tcp_ecn_maxretries		VNET(tcp_ecn_maxretries)
813 #define	V_tcp_initcwnd_segments		VNET(tcp_initcwnd_segments)
814 #define	V_tcp_insecure_rst		VNET(tcp_insecure_rst)
815 #define	V_tcp_insecure_syn		VNET(tcp_insecure_syn)
816 #define	V_tcp_minmss			VNET(tcp_minmss)
817 #define	V_tcp_mssdflt			VNET(tcp_mssdflt)
818 #define	V_tcp_recvspace			VNET(tcp_recvspace)
819 #define	V_tcp_sack_globalholes		VNET(tcp_sack_globalholes)
820 #define	V_tcp_sack_globalmaxholes	VNET(tcp_sack_globalmaxholes)
821 #define	V_tcp_sack_maxholes		VNET(tcp_sack_maxholes)
822 #define	V_tcp_sc_rst_sock_fail		VNET(tcp_sc_rst_sock_fail)
823 #define	V_tcp_sendspace			VNET(tcp_sendspace)
824 #define	V_tcp_udp_tunneling_overhead	VNET(tcp_udp_tunneling_overhead)
825 #define	V_tcp_udp_tunneling_port	VNET(tcp_udp_tunneling_port)
826 
827 
828 #ifdef TCP_HHOOK
829 VNET_DECLARE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST + 1]);
830 #define	V_tcp_hhh		VNET(tcp_hhh)
831 #endif
832 
833 int	 tcp_addoptions(struct tcpopt *, u_char *);
834 int	 tcp_ccalgounload(struct cc_algo *unload_algo);
835 struct tcpcb *
836 	 tcp_close(struct tcpcb *);
837 void	 tcp_discardcb(struct tcpcb *);
838 void	 tcp_twstart(struct tcpcb *);
839 void	 tcp_twclose(struct tcptw *, int);
840 void	 tcp_ctlinput(int, struct sockaddr *, void *);
841 int	 tcp_ctloutput(struct socket *, struct sockopt *);
842 struct tcpcb *
843 	 tcp_drop(struct tcpcb *, int);
844 void	 tcp_drain(void);
845 void	 tcp_init(void);
846 void	 tcp_fini(void *);
847 char	*tcp_log_addrs(struct in_conninfo *, struct tcphdr *, void *,
848 	    const void *);
849 char	*tcp_log_vain(struct in_conninfo *, struct tcphdr *, void *,
850 	    const void *);
851 int	 tcp_reass(struct tcpcb *, struct tcphdr *, tcp_seq *, int *, struct mbuf *);
852 void	 tcp_reass_global_init(void);
853 void	 tcp_reass_flush(struct tcpcb *);
854 void	 tcp_dooptions(struct tcpopt *, u_char *, int, int);
855 void	tcp_dropwithreset(struct mbuf *, struct tcphdr *,
856 		     struct tcpcb *, int, int);
857 void	tcp_pulloutofband(struct socket *,
858 		     struct tcphdr *, struct mbuf *, int);
859 void	tcp_xmit_timer(struct tcpcb *, int);
860 void	tcp_newreno_partial_ack(struct tcpcb *, struct tcphdr *);
861 void	cc_ack_received(struct tcpcb *tp, struct tcphdr *th,
862 			    uint16_t nsegs, uint16_t type);
863 void 	cc_conn_init(struct tcpcb *tp);
864 void 	cc_post_recovery(struct tcpcb *tp, struct tcphdr *th);
865 void	cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type);
866 #ifdef TCP_HHOOK
867 void	hhook_run_tcp_est_in(struct tcpcb *tp,
868 			    struct tcphdr *th, struct tcpopt *to);
869 #endif
870 
871 int	 tcp_input(struct mbuf **, int *, int);
872 int	 tcp_autorcvbuf(struct mbuf *, struct tcphdr *, struct socket *,
873 	    struct tcpcb *, int);
874 void	 tcp_do_segment(struct mbuf *, struct tcphdr *,
875 			struct socket *, struct tcpcb *, int, int, uint8_t);
876 
877 int register_tcp_functions(struct tcp_function_block *blk, int wait);
878 int register_tcp_functions_as_names(struct tcp_function_block *blk,
879     int wait, const char *names[], int *num_names);
880 int register_tcp_functions_as_name(struct tcp_function_block *blk,
881     const char *name, int wait);
882 int deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce,
883     bool force);
884 struct tcp_function_block *find_and_ref_tcp_functions(struct tcp_function_set *fs);
885 void tcp_switch_back_to_default(struct tcpcb *tp);
886 struct tcp_function_block *
887 find_and_ref_tcp_fb(struct tcp_function_block *fs);
888 int tcp_default_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp);
889 
890 extern counter_u64_t tcp_inp_lro_direct_queue;
891 extern counter_u64_t tcp_inp_lro_wokeup_queue;
892 extern counter_u64_t tcp_inp_lro_compressed;
893 extern counter_u64_t tcp_inp_lro_single_push;
894 extern counter_u64_t tcp_inp_lro_locks_taken;
895 extern counter_u64_t tcp_inp_lro_sack_wake;
896 
897 uint32_t tcp_maxmtu(struct in_conninfo *, struct tcp_ifcap *);
898 uint32_t tcp_maxmtu6(struct in_conninfo *, struct tcp_ifcap *);
899 u_int	 tcp_maxseg(const struct tcpcb *);
900 void	 tcp_mss_update(struct tcpcb *, int, int, struct hc_metrics_lite *,
901 	    struct tcp_ifcap *);
902 void	 tcp_mss(struct tcpcb *, int);
903 int	 tcp_mssopt(struct in_conninfo *);
904 struct inpcb *
905 	 tcp_drop_syn_sent(struct inpcb *, int);
906 struct tcpcb *
907 	 tcp_newtcpcb(struct inpcb *);
908 int	 tcp_output(struct tcpcb *);
909 void	 tcp_state_change(struct tcpcb *, int);
910 void	 tcp_respond(struct tcpcb *, void *,
911 	    struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
912 void	 tcp_tw_init(void);
913 #ifdef VIMAGE
914 void	 tcp_tw_destroy(void);
915 #endif
916 void	 tcp_tw_zone_change(void);
917 int	 tcp_twcheck(struct inpcb *, struct tcpopt *, struct tcphdr *,
918 	    struct mbuf *, int);
919 void	 tcp_setpersist(struct tcpcb *);
920 void	 tcp_slowtimo(void);
921 struct tcptemp *
922 	 tcpip_maketemplate(struct inpcb *);
923 void	 tcpip_fillheaders(struct inpcb *, void *, void *);
924 void	 tcp_timer_activate(struct tcpcb *, uint32_t, u_int);
925 int	 tcp_timer_suspend(struct tcpcb *, uint32_t);
926 void	 tcp_timers_unsuspend(struct tcpcb *, uint32_t);
927 int	 tcp_timer_active(struct tcpcb *, uint32_t);
928 void	 tcp_timer_stop(struct tcpcb *, uint32_t);
929 void	 tcp_trace(short, short, struct tcpcb *, void *, struct tcphdr *, int);
930 int	 inp_to_cpuid(struct inpcb *inp);
931 /*
932  * All tcp_hc_* functions are IPv4 and IPv6 (via in_conninfo)
933  */
934 void	 tcp_hc_init(void);
935 #ifdef VIMAGE
936 void	 tcp_hc_destroy(void);
937 #endif
938 void	 tcp_hc_get(struct in_conninfo *, struct hc_metrics_lite *);
939 uint32_t tcp_hc_getmtu(struct in_conninfo *);
940 void	 tcp_hc_updatemtu(struct in_conninfo *, uint32_t);
941 void	 tcp_hc_update(struct in_conninfo *, struct hc_metrics_lite *);
942 
943 extern	struct pr_usrreqs tcp_usrreqs;
944 
945 uint32_t tcp_new_ts_offset(struct in_conninfo *);
946 tcp_seq	 tcp_new_isn(struct in_conninfo *);
947 
948 int	 tcp_sack_doack(struct tcpcb *, struct tcpopt *, tcp_seq);
949 void	 tcp_update_dsack_list(struct tcpcb *, tcp_seq, tcp_seq);
950 void	 tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend);
951 void	 tcp_clean_dsack_blocks(struct tcpcb *tp);
952 void	 tcp_clean_sackreport(struct tcpcb *tp);
953 void	 tcp_sack_adjust(struct tcpcb *tp);
954 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt);
955 void	 tcp_sack_partialack(struct tcpcb *, struct tcphdr *);
956 void	 tcp_free_sackholes(struct tcpcb *tp);
957 int	 tcp_newreno(struct tcpcb *, struct tcphdr *);
958 int	 tcp_compute_pipe(struct tcpcb *);
959 uint32_t tcp_compute_initwnd(uint32_t);
960 void	 tcp_sndbuf_autoscale(struct tcpcb *, struct socket *, uint32_t);
961 struct mbuf *
962 	 tcp_m_copym(struct mbuf *m, int32_t off0, int32_t *plen,
963 	   int32_t seglimit, int32_t segsize, struct sockbuf *sb, bool hw_tls);
964 
965 
966 static inline void
967 tcp_fields_to_host(struct tcphdr *th)
968 {
969 
970 	th->th_seq = ntohl(th->th_seq);
971 	th->th_ack = ntohl(th->th_ack);
972 	th->th_win = ntohs(th->th_win);
973 	th->th_urp = ntohs(th->th_urp);
974 }
975 
976 static inline void
977 tcp_fields_to_net(struct tcphdr *th)
978 {
979 
980 	th->th_seq = htonl(th->th_seq);
981 	th->th_ack = htonl(th->th_ack);
982 	th->th_win = htons(th->th_win);
983 	th->th_urp = htons(th->th_urp);
984 }
985 #endif /* _KERNEL */
986 
987 #endif /* _NETINET_TCP_VAR_H_ */
988