xref: /freebsd/sys/netinet/tcp_var.h (revision 4731124cace5e7a0224e29784617d2856e5c59ab)
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 "opt_kern_tls.h"
43 #include <net/vnet.h>
44 #include <sys/mbuf.h>
45 #include <sys/ktls.h>
46 #endif
47 
48 #define TCP_END_BYTE_INFO 8	/* Bytes that makeup the "end information array" */
49 /* Types of ending byte info */
50 #define TCP_EI_EMPTY_SLOT	0
51 #define TCP_EI_STATUS_CLIENT_FIN	0x1
52 #define TCP_EI_STATUS_CLIENT_RST	0x2
53 #define TCP_EI_STATUS_SERVER_FIN	0x3
54 #define TCP_EI_STATUS_SERVER_RST	0x4
55 #define TCP_EI_STATUS_RETRAN		0x5
56 #define TCP_EI_STATUS_PROGRESS		0x6
57 #define TCP_EI_STATUS_PERSIST_MAX	0x7
58 #define TCP_EI_STATUS_KEEP_MAX		0x8
59 #define TCP_EI_STATUS_DATA_A_CLOSE	0x9
60 #define TCP_EI_STATUS_RST_IN_FRONT	0xa
61 #define TCP_EI_STATUS_2MSL		0xb
62 #define TCP_EI_STATUS_MAX_VALUE		0xb
63 
64 /************************************************/
65 /* Status bits we track to assure no duplicates,
66  * the bits here are not used by the code but
67  * for human representation. To check a bit we
68  * take and shift over by 1 minus the value (1-8).
69  */
70 /************************************************/
71 #define TCP_EI_BITS_CLIENT_FIN	0x001
72 #define TCP_EI_BITS_CLIENT_RST	0x002
73 #define TCP_EI_BITS_SERVER_FIN	0x004
74 #define TCP_EI_BITS_SERVER_RST	0x008
75 #define TCP_EI_BITS_RETRAN	0x010
76 #define TCP_EI_BITS_PROGRESS	0x020
77 #define TCP_EI_BITS_PRESIST_MAX	0x040
78 #define TCP_EI_BITS_KEEP_MAX	0x080
79 #define TCP_EI_BITS_DATA_A_CLO  0x100
80 #define TCP_EI_BITS_RST_IN_FR	0x200	/* a front state reset */
81 #define TCP_EI_BITS_2MS_TIMER	0x400	/* 2 MSL timer expired */
82 
83 #if defined(_KERNEL) || defined(_WANT_TCPCB)
84 /* TCP segment queue entry */
85 struct tseg_qent {
86 	TAILQ_ENTRY(tseg_qent) tqe_q;
87 	struct	mbuf   *tqe_m;		/* mbuf contains packet */
88 	struct  mbuf   *tqe_last;	/* last mbuf in chain */
89 	tcp_seq tqe_start;		/* TCP Sequence number start */
90 	int	tqe_len;		/* TCP segment data length */
91 	uint32_t tqe_flags;		/* The flags from the th->th_flags */
92 	uint32_t tqe_mbuf_cnt;		/* Count of mbuf overhead */
93 };
94 TAILQ_HEAD(tsegqe_head, tseg_qent);
95 
96 struct sackblk {
97 	tcp_seq start;		/* start seq no. of sack block */
98 	tcp_seq end;		/* end seq no. */
99 };
100 
101 struct sackhole {
102 	tcp_seq start;		/* start seq no. of hole */
103 	tcp_seq end;		/* end seq no. */
104 	tcp_seq rxmit;		/* next seq. no in hole to be retransmitted */
105 	TAILQ_ENTRY(sackhole) scblink;	/* scoreboard linkage */
106 };
107 
108 struct sackhint {
109 	struct sackhole	*nexthole;
110 	int32_t		sack_bytes_rexmit;
111 	tcp_seq		last_sack_ack;	/* Most recent/largest sacked ack */
112 
113 	int32_t		delivered_data; /* Newly acked data from last SACK */
114 
115 	int32_t		sacked_bytes;	/* Total sacked bytes reported by the
116 					 * receiver via sack option
117 					 */
118 	uint32_t	recover_fs;	/* Flight Size at the start of Loss recovery */
119 	uint32_t	prr_delivered;	/* Total bytes delivered using PRR */
120 	uint32_t	prr_out;	/* Bytes sent during IN_RECOVERY */
121 };
122 
123 #define SEGQ_EMPTY(tp) TAILQ_EMPTY(&(tp)->t_segq)
124 
125 STAILQ_HEAD(tcp_log_stailq, tcp_log_mem);
126 
127 /*
128  * Tcp control block, one per tcp; fields:
129  * Organized for 64 byte cacheline efficiency based
130  * on common tcp_input/tcp_output processing.
131  */
132 struct tcpcb {
133 	/* Cache line 1 */
134 	struct	inpcb *t_inpcb;		/* back pointer to internet pcb */
135 	struct tcp_function_block *t_fb;/* TCP function call block */
136 	void	*t_fb_ptr;		/* Pointer to t_fb specific data */
137 	uint32_t t_maxseg:24,		/* maximum segment size */
138 		t_logstate:8;		/* State of "black box" logging */
139 	uint32_t t_port:16,		/* Tunneling (over udp) port */
140 		t_state:4,		/* state of this connection */
141 		t_idle_reduce : 1,
142 		t_delayed_ack: 7,	/* Delayed ack variable */
143 		t_fin_is_rst: 1,	/* Are fin's treated as resets */
144 		t_log_state_set: 1,
145 		bits_spare : 2;
146 	u_int	t_flags;
147 	tcp_seq	snd_una;		/* sent but unacknowledged */
148 	tcp_seq	snd_max;		/* highest sequence number sent;
149 					 * used to recognize retransmits
150 					 */
151 	tcp_seq	snd_nxt;		/* send next */
152 	tcp_seq	snd_up;			/* send urgent pointer */
153 	uint32_t  snd_wnd;		/* send window */
154 	uint32_t  snd_cwnd;		/* congestion-controlled window */
155 	uint32_t t_peakrate_thr; 	/* pre-calculated peak rate threshold */
156 	/* Cache line 2 */
157 	u_int32_t  ts_offset;		/* our timestamp offset */
158 	u_int32_t	rfbuf_ts;	/* recv buffer autoscaling timestamp */
159 	int	rcv_numsacks;		/* # distinct sack blks present */
160 	u_int	t_tsomax;		/* TSO total burst length limit in bytes */
161 	u_int	t_tsomaxsegcount;	/* TSO maximum segment count */
162 	u_int	t_tsomaxsegsize;	/* TSO maximum segment size in bytes */
163 	tcp_seq	rcv_nxt;		/* receive next */
164 	tcp_seq	rcv_adv;		/* advertised window */
165 	uint32_t  rcv_wnd;		/* receive window */
166 	u_int	t_flags2;		/* More tcpcb flags storage */
167 	int	t_srtt;			/* smoothed round-trip time */
168 	int	t_rttvar;		/* variance in round-trip time */
169 	u_int32_t  ts_recent;		/* timestamp echo data */
170 	u_char	snd_scale;		/* window scaling for send window */
171 	u_char	rcv_scale;		/* window scaling for recv window */
172 	u_char	snd_limited;		/* segments limited transmitted */
173 	u_char	request_r_scale;	/* pending window scaling */
174 	tcp_seq	last_ack_sent;
175 	u_int	t_rcvtime;		/* inactivity time */
176 	/* Cache line 3 */
177 	tcp_seq	rcv_up;			/* receive urgent pointer */
178 	int	t_segqlen;		/* segment reassembly queue length */
179 	uint32_t t_segqmbuflen;		/* Count of bytes mbufs on all entries */
180 	struct	tsegqe_head t_segq;	/* segment reassembly queue */
181 	struct mbuf      *t_in_pkt;
182 	struct mbuf	 *t_tail_pkt;
183 	struct tcp_timer *t_timers;	/* All the TCP timers in one struct */
184 	struct	vnet *t_vnet;		/* back pointer to parent vnet */
185 	uint32_t  snd_ssthresh;		/* snd_cwnd size threshold for
186 					 * for slow start exponential to
187 					 * linear switch
188 					 */
189 	tcp_seq	snd_wl1;		/* window update seg seq number */
190 	/* Cache line 4 */
191 	tcp_seq	snd_wl2;		/* window update seg ack number */
192 
193 	tcp_seq	irs;			/* initial receive sequence number */
194 	tcp_seq	iss;			/* initial send sequence number */
195 	u_int	t_acktime;		/* RACK and BBR incoming new data was acked */
196 	u_int	t_sndtime;		/* time last data was sent */
197 	u_int	ts_recent_age;		/* when last updated */
198 	tcp_seq	snd_recover;		/* for use in NewReno Fast Recovery */
199 	uint16_t cl4_spare;		/* Spare to adjust CL 4 */
200 	char	t_oobflags;		/* have some */
201 	char	t_iobc;			/* input character */
202 	int	t_rxtcur;		/* current retransmit value (ticks) */
203 
204 	int	t_rxtshift;		/* log(2) of rexmt exp. backoff */
205 	u_int	t_rtttime;		/* RTT measurement start time */
206 
207 	tcp_seq	t_rtseq;		/* sequence number being timed */
208 	u_int	t_starttime;		/* time connection was established */
209 	u_int	t_fbyte_in;		/* ticks time when first byte queued in */
210 	u_int	t_fbyte_out;		/* ticks time when first byte queued out */
211 
212 	u_int	t_pmtud_saved_maxseg;	/* pre-blackhole MSS */
213 	int	t_blackhole_enter;	/* when to enter blackhole detection */
214 	int	t_blackhole_exit;	/* when to exit blackhole detection */
215 	u_int	t_rttmin;		/* minimum rtt allowed */
216 
217 	u_int	t_rttbest;		/* best rtt we've seen */
218 
219 	int	t_softerror;		/* possible error not yet reported */
220 	uint32_t  max_sndwnd;		/* largest window peer has offered */
221 	/* Cache line 5 */
222 	uint32_t  snd_cwnd_prev;	/* cwnd prior to retransmit */
223 	uint32_t  snd_ssthresh_prev;	/* ssthresh prior to retransmit */
224 	tcp_seq	snd_recover_prev;	/* snd_recover prior to retransmit */
225 	int	t_sndzerowin;		/* zero-window updates sent */
226 	u_long	t_rttupdated;		/* number of times rtt sampled */
227 	int	snd_numholes;		/* number of holes seen by sender */
228 	u_int	t_badrxtwin;		/* window for retransmit recovery */
229 	TAILQ_HEAD(sackhole_head, sackhole) snd_holes;
230 					/* SACK scoreboard (sorted) */
231 	tcp_seq	snd_fack;		/* last seq number(+1) sack'd by rcv'r*/
232 	struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
233 	struct sackhint	sackhint;	/* SACK scoreboard hint */
234 	int	t_rttlow;		/* smallest observerved RTT */
235 	int	rfbuf_cnt;		/* recv buffer autoscaling byte count */
236 	struct toedev	*tod;		/* toedev handling this connection */
237 	int	t_sndrexmitpack;	/* retransmit packets sent */
238 	int	t_rcvoopack;		/* out-of-order packets received */
239 	void	*t_toe;			/* TOE pcb pointer */
240 	struct cc_algo	*cc_algo;	/* congestion control algorithm */
241 	struct cc_var	*ccv;		/* congestion control specific vars */
242 	struct osd	*osd;		/* storage for Khelp module data */
243 	int	t_bytes_acked;		/* # bytes acked during current RTT */
244 	u_int   t_maxunacktime;
245 	u_int	t_keepinit;		/* time to establish connection */
246 	u_int	t_keepidle;		/* time before keepalive probes begin */
247 	u_int	t_keepintvl;		/* interval between keepalives */
248 	u_int	t_keepcnt;		/* number of keepalives before close */
249 	int	t_dupacks;		/* consecutive dup acks recd */
250 	int	t_lognum;		/* Number of log entries */
251 	int	t_loglimit;		/* Maximum number of log entries */
252 	int64_t	t_pacing_rate;		/* bytes / sec, -1 => unlimited */
253 	struct tcp_log_stailq t_logs;	/* Log buffer */
254 	struct tcp_log_id_node *t_lin;
255 	struct tcp_log_id_bucket *t_lib;
256 	const char *t_output_caller;	/* Function that called tcp_output */
257 	struct statsblob *t_stats;	/* Per-connection stats */
258 	uint32_t t_logsn;		/* Log "serial number" */
259 	uint32_t gput_ts;		/* Time goodput measurement started */
260 	tcp_seq gput_seq;		/* Outbound measurement seq */
261 	tcp_seq gput_ack;		/* Inbound measurement ack */
262 	int32_t t_stats_gput_prev;	/* XXXLAS: Prev gput measurement */
263 	uint32_t t_maxpeakrate;		/* max peak rate set by user, in bytes/s */
264 	uint32_t t_sndtlppack;		/* tail loss probe packets sent */
265 	uint64_t t_sndtlpbyte;		/* total tail loss probe bytes sent */
266 	uint64_t t_sndbytes;		/* total bytes sent */
267 	uint64_t t_snd_rxt_bytes;	/* total bytes retransmitted */
268 	uint32_t t_dsack_bytes;		/* Total number of dsack bytes we have received */
269 	uint32_t t_dsack_tlp_bytes;	/* Total number of dsack bytes we have received for TLPs sent */
270 	uint32_t t_dsack_pack;		/* Total dsack packets we have recieved */
271 
272 	uint8_t t_tfo_client_cookie_len; /* TCP Fast Open client cookie length */
273 	uint32_t t_end_info_status;	/* Status flag of end info */
274 	unsigned int *t_tfo_pending;	/* TCP Fast Open server pending counter */
275 	union {
276 		uint8_t client[TCP_FASTOPEN_MAX_COOKIE_LEN];
277 		uint64_t server;
278 	} t_tfo_cookie;			/* TCP Fast Open cookie to send */
279 	union {
280 		uint8_t t_end_info_bytes[TCP_END_BYTE_INFO];
281 		uint64_t t_end_info;
282 	};
283 #ifdef TCPPCAP
284 	struct mbufq t_inpkts;		/* List of saved input packets. */
285 	struct mbufq t_outpkts;		/* List of saved output packets. */
286 #endif
287 };
288 #endif	/* _KERNEL || _WANT_TCPCB */
289 
290 #ifdef _KERNEL
291 struct tcptemp {
292 	u_char	tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
293 	struct	tcphdr tt_t;
294 };
295 
296 /* Enable TCP/UDP tunneling port */
297 #define TCP_TUNNELING_PORT_MIN		0
298 #define TCP_TUNNELING_PORT_MAX		65535
299 #define TCP_TUNNELING_PORT_DEFAULT	0
300 
301 /* Enable TCP/UDP tunneling port */
302 #define TCP_TUNNELING_OVERHEAD_MIN	sizeof(struct udphdr)
303 #define TCP_TUNNELING_OVERHEAD_MAX	1024
304 #define TCP_TUNNELING_OVERHEAD_DEFAULT	TCP_TUNNELING_OVERHEAD_MIN
305 
306 /* Minimum map entries limit value, if set */
307 #define TCP_MIN_MAP_ENTRIES_LIMIT	128
308 
309 /*
310  * TODO: We yet need to brave plowing in
311  * to tcp_input() and the pru_usrreq() block.
312  * Right now these go to the old standards which
313  * are somewhat ok, but in the long term may
314  * need to be changed. If we do tackle tcp_input()
315  * then we need to get rid of the tcp_do_segment()
316  * function below.
317  */
318 /* Flags for tcp functions */
319 #define	TCP_FUNC_BEING_REMOVED	0x01   	/* Can no longer be referenced */
320 #define	TCP_FUNC_OUTPUT_CANDROP	0x02   	/* tfb_tcp_output may ask tcp_drop */
321 
322 /*
323  * If defining the optional tcp_timers, in the
324  * tfb_tcp_timer_stop call you must use the
325  * callout_async_drain() function with the
326  * tcp_timer_discard callback. You should check
327  * the return of callout_async_drain() and if 0
328  * increment tt_draincnt. Since the timer sub-system
329  * does not know your callbacks you must provide a
330  * stop_all function that loops through and calls
331  * tcp_timer_stop() with each of your defined timers.
332  * Adding a tfb_tcp_handoff_ok function allows the socket
333  * option to change stacks to query you even if the
334  * connection is in a later stage. You return 0 to
335  * say you can take over and run your stack, you return
336  * non-zero (an error number) to say no you can't.
337  * If the function is undefined you can only change
338  * in the early states (before connect or listen).
339  * tfb_tcp_fb_fini is changed to add a flag to tell
340  * the old stack if the tcb is being destroyed or
341  * not. A one in the flag means the TCB is being
342  * destroyed, a zero indicates its transitioning to
343  * another stack (via socket option).
344  */
345 struct tcp_function_block {
346 	char tfb_tcp_block_name[TCP_FUNCTION_NAME_LEN_MAX];
347 	int	(*tfb_tcp_output)(struct tcpcb *);
348 	int	(*tfb_tcp_output_wtime)(struct tcpcb *, const struct timeval *);
349 	void	(*tfb_tcp_do_segment)(struct mbuf *, struct tcphdr *,
350 			    struct socket *, struct tcpcb *,
351 		        int, int, uint8_t);
352 	int     (*tfb_do_queued_segments)(struct socket *, struct tcpcb *, int);
353 	int      (*tfb_do_segment_nounlock)(struct mbuf *, struct tcphdr *,
354 			    struct socket *, struct tcpcb *,
355 			    int, int, uint8_t,
356 			    int, struct timeval *);
357 	void	(*tfb_tcp_hpts_do_segment)(struct mbuf *, struct tcphdr *,
358 			    struct socket *, struct tcpcb *,
359 			    int, int, uint8_t,
360 			    int, struct timeval *);
361 	int     (*tfb_tcp_ctloutput)(struct socket *so, struct sockopt *sopt,
362 			    struct inpcb *inp, struct tcpcb *tp);
363 	/* Optional memory allocation/free routine */
364 	int	(*tfb_tcp_fb_init)(struct tcpcb *);
365 	void	(*tfb_tcp_fb_fini)(struct tcpcb *, int);
366 	/* Optional timers, must define all if you define one */
367 	int	(*tfb_tcp_timer_stop_all)(struct tcpcb *);
368 	void	(*tfb_tcp_timer_activate)(struct tcpcb *,
369 			    uint32_t, u_int);
370 	int	(*tfb_tcp_timer_active)(struct tcpcb *, uint32_t);
371 	void	(*tfb_tcp_timer_stop)(struct tcpcb *, uint32_t);
372 	void	(*tfb_tcp_rexmit_tmr)(struct tcpcb *);
373 	int	(*tfb_tcp_handoff_ok)(struct tcpcb *);
374 	void	(*tfb_tcp_mtu_chg)(struct tcpcb *);
375 	int	(*tfb_pru_options)(struct tcpcb *, int);
376 	void	(*tfb_hwtls_change)(struct tcpcb *, int);
377 	volatile uint32_t tfb_refcnt;
378 	uint32_t  tfb_flags;
379 	uint8_t	tfb_id;
380 };
381 
382 struct tcp_function {
383 	TAILQ_ENTRY(tcp_function)	tf_next;
384 	char				tf_name[TCP_FUNCTION_NAME_LEN_MAX];
385 	struct tcp_function_block	*tf_fb;
386 };
387 
388 TAILQ_HEAD(tcp_funchead, tcp_function);
389 
390 struct tcpcb * tcp_drop(struct tcpcb *, int);
391 
392 #ifdef _NETINET_IN_PCB_H_
393 /*
394  * tcp_output()
395  * Handles tcp_drop request from advanced stacks and reports that inpcb is
396  * gone with negative return code.
397  * Drop in replacement for the default stack.
398  */
399 static inline int
400 tcp_output(struct tcpcb *tp)
401 {
402 	int rv;
403 
404 	INP_WLOCK_ASSERT(tp->t_inpcb);
405 
406 	rv = tp->t_fb->tfb_tcp_output(tp);
407 	if (rv < 0) {
408 		KASSERT(tp->t_fb->tfb_flags & TCP_FUNC_OUTPUT_CANDROP,
409 		    ("TCP stack %s requested tcp_drop(%p)",
410 		    tp->t_fb->tfb_tcp_block_name, tp));
411 		tp = tcp_drop(tp, -rv);
412 		if (tp)
413 			INP_WUNLOCK(tp->t_inpcb);
414 	}
415 
416 	return (rv);
417 }
418 
419 /*
420  * tcp_output_unlock()
421  * Always returns unlocked, handles drop request from advanced stacks.
422  * Always returns positive error code.
423  */
424 static inline int
425 tcp_output_unlock(struct tcpcb *tp)
426 {
427 	int rv;
428 
429 	INP_WLOCK_ASSERT(tp->t_inpcb);
430 
431 	rv = tp->t_fb->tfb_tcp_output(tp);
432 	if (rv < 0) {
433 		KASSERT(tp->t_fb->tfb_flags & TCP_FUNC_OUTPUT_CANDROP,
434 		    ("TCP stack %s requested tcp_drop(%p)",
435 		    tp->t_fb->tfb_tcp_block_name, tp));
436 		rv = -rv;
437 		tp = tcp_drop(tp, rv);
438 		if (tp)
439 			INP_WUNLOCK(tp->t_inpcb);
440 	} else
441 		INP_WUNLOCK(tp->t_inpcb);
442 
443 	return (rv);
444 }
445 
446 /*
447  * tcp_output_nodrop()
448  * Always returns locked.  It is caller's responsibility to run tcp_drop()!
449  * Useful in syscall implementations, when we want to perform some logging
450  * and/or tracing with tcpcb before calling tcp_drop().  To be used with
451  * tcp_unlock_or_drop() later.
452  *
453  * XXXGL: maybe don't allow stacks to return a drop request at certain
454  * TCP states? Why would it do in connect(2)? In recv(2)?
455  */
456 static inline int
457 tcp_output_nodrop(struct tcpcb *tp)
458 {
459 	int rv;
460 
461 	INP_WLOCK_ASSERT(tp->t_inpcb);
462 
463 	rv = tp->t_fb->tfb_tcp_output(tp);
464 	KASSERT(rv >= 0 || tp->t_fb->tfb_flags & TCP_FUNC_OUTPUT_CANDROP,
465 	    ("TCP stack %s requested tcp_drop(%p)",
466 	    tp->t_fb->tfb_tcp_block_name, tp));
467 	return (rv);
468 }
469 
470 /*
471  * tcp_unlock_or_drop()
472  * Handle return code from tfb_tcp_output() after we have logged/traced,
473  * to be used with tcp_output_nodrop().
474  */
475 static inline int
476 tcp_unlock_or_drop(struct tcpcb *tp, int tcp_output_retval)
477 {
478 
479 	INP_WLOCK_ASSERT(tp->t_inpcb);
480 
481         if (tcp_output_retval < 0) {
482                 tcp_output_retval = -tcp_output_retval;
483                 if (tcp_drop(tp, tcp_output_retval) != NULL)
484                         INP_WUNLOCK(tp->t_inpcb);
485         } else
486 		INP_WUNLOCK(tp->t_inpcb);
487 
488 	return (tcp_output_retval);
489 }
490 #endif	/* _NETINET_IN_PCB_H_ */
491 #endif	/* _KERNEL */
492 
493 /*
494  * Flags and utility macros for the t_flags field.
495  */
496 #define	TF_ACKNOW	0x00000001	/* ack peer immediately */
497 #define	TF_DELACK	0x00000002	/* ack, but try to delay it */
498 #define	TF_NODELAY	0x00000004	/* don't delay packets to coalesce */
499 #define	TF_NOOPT	0x00000008	/* don't use tcp options */
500 #define	TF_SENTFIN	0x00000010	/* have sent FIN */
501 #define	TF_REQ_SCALE	0x00000020	/* have/will request window scaling */
502 #define	TF_RCVD_SCALE	0x00000040	/* other side has requested scaling */
503 #define	TF_REQ_TSTMP	0x00000080	/* have/will request timestamps */
504 #define	TF_RCVD_TSTMP	0x00000100	/* a timestamp was received in SYN */
505 #define	TF_SACK_PERMIT	0x00000200	/* other side said I could SACK */
506 #define	TF_NEEDSYN	0x00000400	/* send SYN (implicit state) */
507 #define	TF_NEEDFIN	0x00000800	/* send FIN (implicit state) */
508 #define	TF_NOPUSH	0x00001000	/* don't push */
509 #define	TF_PREVVALID	0x00002000	/* saved values for bad rxmit valid */
510 #define	TF_WAKESOR	0x00004000	/* wake up receive socket */
511 #define	TF_GPUTINPROG	0x00008000	/* Goodput measurement in progress */
512 #define	TF_MORETOCOME	0x00010000	/* More data to be appended to sock */
513 #define	TF_LQ_OVERFLOW	0x00020000	/* listen queue overflow */
514 #define	TF_LASTIDLE	0x00040000	/* connection was previously idle */
515 #define	TF_RXWIN0SENT	0x00080000	/* sent a receiver win 0 in response */
516 #define	TF_FASTRECOVERY	0x00100000	/* in NewReno Fast Recovery */
517 #define	TF_WASFRECOVERY	0x00200000	/* was in NewReno Fast Recovery */
518 #define	TF_SIGNATURE	0x00400000	/* require MD5 digests (RFC2385) */
519 #define	TF_FORCEDATA	0x00800000	/* force out a byte */
520 #define	TF_TSO		0x01000000	/* TSO enabled on this connection */
521 #define	TF_TOE		0x02000000	/* this connection is offloaded */
522 #define	TF_UNUSED0	0x04000000	/* unused */
523 #define	TF_UNUSED1	0x08000000	/* unused */
524 #define	TF_LRD		0x10000000	/* Lost Retransmission Detection */
525 #define	TF_CONGRECOVERY	0x20000000	/* congestion recovery mode */
526 #define	TF_WASCRECOVERY	0x40000000	/* was in congestion recovery */
527 #define	TF_FASTOPEN	0x80000000	/* TCP Fast Open indication */
528 
529 #define	IN_FASTRECOVERY(t_flags)	(t_flags & TF_FASTRECOVERY)
530 #define	ENTER_FASTRECOVERY(t_flags)	t_flags |= TF_FASTRECOVERY
531 #define	EXIT_FASTRECOVERY(t_flags)	t_flags &= ~TF_FASTRECOVERY
532 
533 #define	IN_CONGRECOVERY(t_flags)	(t_flags & TF_CONGRECOVERY)
534 #define	ENTER_CONGRECOVERY(t_flags)	t_flags |= TF_CONGRECOVERY
535 #define	EXIT_CONGRECOVERY(t_flags)	t_flags &= ~TF_CONGRECOVERY
536 
537 #define	IN_RECOVERY(t_flags) (t_flags & (TF_CONGRECOVERY | TF_FASTRECOVERY))
538 #define	ENTER_RECOVERY(t_flags) t_flags |= (TF_CONGRECOVERY | TF_FASTRECOVERY)
539 #define	EXIT_RECOVERY(t_flags) t_flags &= ~(TF_CONGRECOVERY | TF_FASTRECOVERY)
540 
541 #if defined(_KERNEL) && !defined(TCP_RFC7413)
542 #define	IS_FASTOPEN(t_flags)		(false)
543 #else
544 #define	IS_FASTOPEN(t_flags)		(t_flags & TF_FASTOPEN)
545 #endif
546 
547 #define	BYTES_THIS_ACK(tp, th)	(th->th_ack - tp->snd_una)
548 
549 /*
550  * Flags for the t_oobflags field.
551  */
552 #define	TCPOOB_HAVEDATA	0x01
553 #define	TCPOOB_HADDATA	0x02
554 
555 /*
556  * Flags for the extended TCP flags field, t_flags2
557  */
558 #define	TF2_PLPMTU_BLACKHOLE	0x00000001 /* Possible PLPMTUD Black Hole. */
559 #define	TF2_PLPMTU_PMTUD	0x00000002 /* Allowed to attempt PLPMTUD. */
560 #define	TF2_PLPMTU_MAXSEGSNT	0x00000004 /* Last seg sent was full seg. */
561 #define	TF2_LOG_AUTO		0x00000008 /* Session is auto-logging. */
562 #define TF2_DROP_AF_DATA 	0x00000010 /* Drop after all data ack'd */
563 #define	TF2_ECN_PERMIT		0x00000020 /* connection ECN-ready */
564 #define	TF2_ECN_SND_CWR		0x00000040 /* ECN CWR in queue */
565 #define	TF2_ECN_SND_ECE		0x00000080 /* ECN ECE in queue */
566 #define	TF2_ACE_PERMIT		0x00000100 /* Accurate ECN mode */
567 #define TF2_FBYTES_COMPLETE	0x00000400 /* We have first bytes in and out */
568 /*
569  * Structure to hold TCP options that are only used during segment
570  * processing (in tcp_input), but not held in the tcpcb.
571  * It's basically used to reduce the number of parameters
572  * to tcp_dooptions and tcp_addoptions.
573  * The binary order of the to_flags is relevant for packing of the
574  * options in tcp_addoptions.
575  */
576 struct tcpopt {
577 	u_int32_t	to_flags;	/* which options are present */
578 #define	TOF_MSS		0x0001		/* maximum segment size */
579 #define	TOF_SCALE	0x0002		/* window scaling */
580 #define	TOF_SACKPERM	0x0004		/* SACK permitted */
581 #define	TOF_TS		0x0010		/* timestamp */
582 #define	TOF_SIGNATURE	0x0040		/* TCP-MD5 signature option (RFC2385) */
583 #define	TOF_SACK	0x0080		/* Peer sent SACK option */
584 #define	TOF_FASTOPEN	0x0100		/* TCP Fast Open (TFO) cookie */
585 #define	TOF_MAXOPT	0x0200
586 	u_int32_t	to_tsval;	/* new timestamp */
587 	u_int32_t	to_tsecr;	/* reflected timestamp */
588 	u_char		*to_sacks;	/* pointer to the first SACK blocks */
589 	u_char		*to_signature;	/* pointer to the TCP-MD5 signature */
590 	u_int8_t	*to_tfo_cookie; /* pointer to the TFO cookie */
591 	u_int16_t	to_mss;		/* maximum segment size */
592 	u_int8_t	to_wscale;	/* window scaling */
593 	u_int8_t	to_nsacks;	/* number of SACK blocks */
594 	u_int8_t	to_tfo_len;	/* TFO cookie length */
595 	u_int32_t	to_spare;	/* UTO */
596 };
597 
598 /*
599  * Flags for tcp_dooptions.
600  */
601 #define	TO_SYN		0x01		/* parse SYN-only options */
602 
603 struct hc_metrics_lite {	/* must stay in sync with hc_metrics */
604 	uint32_t	rmx_mtu;	/* MTU for this path */
605 	uint32_t	rmx_ssthresh;	/* outbound gateway buffer limit */
606 	uint32_t	rmx_rtt;	/* estimated round trip time */
607 	uint32_t	rmx_rttvar;	/* estimated rtt variance */
608 	uint32_t	rmx_cwnd;	/* congestion window */
609 	uint32_t	rmx_sendpipe;   /* outbound delay-bandwidth product */
610 	uint32_t	rmx_recvpipe;   /* inbound delay-bandwidth product */
611 };
612 
613 /*
614  * Used by tcp_maxmtu() to communicate interface specific features
615  * and limits at the time of connection setup.
616  */
617 struct tcp_ifcap {
618 	int	ifcap;
619 	u_int	tsomax;
620 	u_int	tsomaxsegcount;
621 	u_int	tsomaxsegsize;
622 };
623 
624 #ifndef _NETINET_IN_PCB_H_
625 struct in_conninfo;
626 #endif /* _NETINET_IN_PCB_H_ */
627 
628 struct tcptw {
629 	struct inpcb	*tw_inpcb;	/* XXX back pointer to internet pcb */
630 	uint32_t  t_port:16,		/* UDP port number if TCPoUDP */
631 		t_unused:16;
632 	tcp_seq		snd_nxt;
633 	tcp_seq		rcv_nxt;
634 	u_short		last_win;	/* cached window value */
635 	short		tw_so_options;	/* copy of so_options */
636 	struct ucred	*tw_cred;	/* user credentials */
637 	u_int32_t	t_recent;
638 	u_int32_t	ts_offset;	/* our timestamp offset */
639 	int		tw_time;
640 	TAILQ_ENTRY(tcptw) tw_2msl;
641 	u_int		tw_flags;	/* tcpcb t_flags */
642 };
643 
644 #define	intotcpcb(ip)	((struct tcpcb *)(ip)->inp_ppcb)
645 #define	intotw(ip)	((struct tcptw *)(ip)->inp_ppcb)
646 #define	sototcpcb(so)	(intotcpcb(sotoinpcb(so)))
647 
648 /*
649  * The smoothed round-trip time and estimated variance
650  * are stored as fixed point numbers scaled by the values below.
651  * For convenience, these scales are also used in smoothing the average
652  * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
653  * With these scales, srtt has 3 bits to the right of the binary point,
654  * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
655  * binary point, and is smoothed with an ALPHA of 0.75.
656  */
657 #define	TCP_RTT_SCALE		32	/* multiplier for srtt; 3 bits frac. */
658 #define	TCP_RTT_SHIFT		5	/* shift for srtt; 3 bits frac. */
659 #define	TCP_RTTVAR_SCALE	16	/* multiplier for rttvar; 2 bits */
660 #define	TCP_RTTVAR_SHIFT	4	/* shift for rttvar; 2 bits */
661 #define	TCP_DELTA_SHIFT		2	/* see tcp_input.c */
662 
663 /*
664  * The initial retransmission should happen at rtt + 4 * rttvar.
665  * Because of the way we do the smoothing, srtt and rttvar
666  * will each average +1/2 tick of bias.  When we compute
667  * the retransmit timer, we want 1/2 tick of rounding and
668  * 1 extra tick because of +-1/2 tick uncertainty in the
669  * firing of the timer.  The bias will give us exactly the
670  * 1.5 tick we need.  But, because the bias is
671  * statistical, we have to test that we don't drop below
672  * the minimum feasible timer (which is 2 ticks).
673  * This version of the macro adapted from a paper by Lawrence
674  * Brakmo and Larry Peterson which outlines a problem caused
675  * by insufficient precision in the original implementation,
676  * which results in inappropriately large RTO values for very
677  * fast networks.
678  */
679 #define	TCP_REXMTVAL(tp) \
680 	max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
681 	  + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
682 
683 /*
684  * TCP statistics.
685  * Many of these should be kept per connection,
686  * but that's inconvenient at the moment.
687  */
688 struct	tcpstat {
689 	uint64_t tcps_connattempt;	/* connections initiated */
690 	uint64_t tcps_accepts;		/* connections accepted */
691 	uint64_t tcps_connects;		/* connections established */
692 	uint64_t tcps_drops;		/* connections dropped */
693 	uint64_t tcps_conndrops;	/* embryonic connections dropped */
694 	uint64_t tcps_minmssdrops;	/* average minmss too low drops */
695 	uint64_t tcps_closed;		/* conn. closed (includes drops) */
696 	uint64_t tcps_segstimed;	/* segs where we tried to get rtt */
697 	uint64_t tcps_rttupdated;	/* times we succeeded */
698 	uint64_t tcps_delack;		/* delayed acks sent */
699 	uint64_t tcps_timeoutdrop;	/* conn. dropped in rxmt timeout */
700 	uint64_t tcps_rexmttimeo;	/* retransmit timeouts */
701 	uint64_t tcps_persisttimeo;	/* persist timeouts */
702 	uint64_t tcps_keeptimeo;	/* keepalive timeouts */
703 	uint64_t tcps_keepprobe;	/* keepalive probes sent */
704 	uint64_t tcps_keepdrops;	/* connections dropped in keepalive */
705 
706 	uint64_t tcps_sndtotal;		/* total packets sent */
707 	uint64_t tcps_sndpack;		/* data packets sent */
708 	uint64_t tcps_sndbyte;		/* data bytes sent */
709 	uint64_t tcps_sndrexmitpack;	/* data packets retransmitted */
710 	uint64_t tcps_sndrexmitbyte;	/* data bytes retransmitted */
711 	uint64_t tcps_sndrexmitbad;	/* unnecessary packet retransmissions */
712 	uint64_t tcps_sndacks;		/* ack-only packets sent */
713 	uint64_t tcps_sndprobe;		/* window probes sent */
714 	uint64_t tcps_sndurg;		/* packets sent with URG only */
715 	uint64_t tcps_sndwinup;		/* window update-only packets sent */
716 	uint64_t tcps_sndctrl;		/* control (SYN|FIN|RST) packets sent */
717 
718 	uint64_t tcps_rcvtotal;		/* total packets received */
719 	uint64_t tcps_rcvpack;		/* packets received in sequence */
720 	uint64_t tcps_rcvbyte;		/* bytes received in sequence */
721 	uint64_t tcps_rcvbadsum;	/* packets received with ccksum errs */
722 	uint64_t tcps_rcvbadoff;	/* packets received with bad offset */
723 	uint64_t tcps_rcvreassfull;	/* packets dropped for no reass space */
724 	uint64_t tcps_rcvshort;		/* packets received too short */
725 	uint64_t tcps_rcvduppack;	/* duplicate-only packets received */
726 	uint64_t tcps_rcvdupbyte;	/* duplicate-only bytes received */
727 	uint64_t tcps_rcvpartduppack;	/* packets with some duplicate data */
728 	uint64_t tcps_rcvpartdupbyte;	/* dup. bytes in part-dup. packets */
729 	uint64_t tcps_rcvoopack;	/* out-of-order packets received */
730 	uint64_t tcps_rcvoobyte;	/* out-of-order bytes received */
731 	uint64_t tcps_rcvpackafterwin;	/* packets with data after window */
732 	uint64_t tcps_rcvbyteafterwin;	/* bytes rcvd after window */
733 	uint64_t tcps_rcvafterclose;	/* packets rcvd after "close" */
734 	uint64_t tcps_rcvwinprobe;	/* rcvd window probe packets */
735 	uint64_t tcps_rcvdupack;	/* rcvd duplicate acks */
736 	uint64_t tcps_rcvacktoomuch;	/* rcvd acks for unsent data */
737 	uint64_t tcps_rcvackpack;	/* rcvd ack packets */
738 	uint64_t tcps_rcvackbyte;	/* bytes acked by rcvd acks */
739 	uint64_t tcps_rcvwinupd;	/* rcvd window update packets */
740 	uint64_t tcps_pawsdrop;		/* segments dropped due to PAWS */
741 	uint64_t tcps_predack;		/* times hdr predict ok for acks */
742 	uint64_t tcps_preddat;		/* times hdr predict ok for data pkts */
743 	uint64_t tcps_pcbcachemiss;
744 	uint64_t tcps_cachedrtt;	/* times cached RTT in route updated */
745 	uint64_t tcps_cachedrttvar;	/* times cached rttvar updated */
746 	uint64_t tcps_cachedssthresh;	/* times cached ssthresh updated */
747 	uint64_t tcps_usedrtt;		/* times RTT initialized from route */
748 	uint64_t tcps_usedrttvar;	/* times RTTVAR initialized from rt */
749 	uint64_t tcps_usedssthresh;	/* times ssthresh initialized from rt*/
750 	uint64_t tcps_persistdrop;	/* timeout in persist state */
751 	uint64_t tcps_badsyn;		/* bogus SYN, e.g. premature ACK */
752 	uint64_t tcps_mturesent;	/* resends due to MTU discovery */
753 	uint64_t tcps_listendrop;	/* listen queue overflows */
754 	uint64_t tcps_badrst;		/* ignored RSTs in the window */
755 
756 	uint64_t tcps_sc_added;		/* entry added to syncache */
757 	uint64_t tcps_sc_retransmitted;	/* syncache entry was retransmitted */
758 	uint64_t tcps_sc_dupsyn;	/* duplicate SYN packet */
759 	uint64_t tcps_sc_dropped;	/* could not reply to packet */
760 	uint64_t tcps_sc_completed;	/* successful extraction of entry */
761 	uint64_t tcps_sc_bucketoverflow;/* syncache per-bucket limit hit */
762 	uint64_t tcps_sc_cacheoverflow;	/* syncache cache limit hit */
763 	uint64_t tcps_sc_reset;		/* RST removed entry from syncache */
764 	uint64_t tcps_sc_stale;		/* timed out or listen socket gone */
765 	uint64_t tcps_sc_aborted;	/* syncache entry aborted */
766 	uint64_t tcps_sc_badack;	/* removed due to bad ACK */
767 	uint64_t tcps_sc_unreach;	/* ICMP unreachable received */
768 	uint64_t tcps_sc_zonefail;	/* zalloc() failed */
769 	uint64_t tcps_sc_sendcookie;	/* SYN cookie sent */
770 	uint64_t tcps_sc_recvcookie;	/* SYN cookie received */
771 
772 	uint64_t tcps_hc_added;		/* entry added to hostcache */
773 	uint64_t tcps_hc_bucketoverflow;/* hostcache per bucket limit hit */
774 
775 	uint64_t tcps_finwait2_drops;    /* Drop FIN_WAIT_2 connection after time limit */
776 
777 	/* SACK related stats */
778 	uint64_t tcps_sack_recovery_episode; /* SACK recovery episodes */
779 	uint64_t tcps_sack_rexmits;	    /* SACK rexmit segments   */
780 	uint64_t tcps_sack_rexmit_bytes;    /* SACK rexmit bytes      */
781 	uint64_t tcps_sack_rcv_blocks;	    /* SACK blocks (options) received */
782 	uint64_t tcps_sack_send_blocks;	    /* SACK blocks (options) sent     */
783 	uint64_t tcps_sack_lostrexmt;	    /* SACK lost retransmission recovered */
784 	uint64_t tcps_sack_sboverflow;	    /* times scoreboard overflowed */
785 
786 	/* ECN related stats */
787 	uint64_t tcps_ecn_ce;		/* ECN Congestion Experienced */
788 	uint64_t tcps_ecn_ect0;		/* ECN Capable Transport */
789 	uint64_t tcps_ecn_ect1;		/* ECN Capable Transport */
790 	uint64_t tcps_ecn_shs;		/* ECN successful handshakes */
791 	uint64_t tcps_ecn_rcwnd;	/* # times ECN reduced the cwnd */
792 
793 	/* TCP_SIGNATURE related stats */
794 	uint64_t tcps_sig_rcvgoodsig;	/* Total matching signature received */
795 	uint64_t tcps_sig_rcvbadsig;	/* Total bad signature received */
796 	uint64_t tcps_sig_err_buildsig;	/* Failed to make signature */
797 	uint64_t tcps_sig_err_sigopt;	/* No signature expected by socket */
798 	uint64_t tcps_sig_err_nosigopt;	/* No signature provided by segment */
799 
800 	/* Path MTU Discovery Black Hole Detection related stats */
801 	uint64_t tcps_pmtud_blackhole_activated;	 /* Black Hole Count */
802 	uint64_t tcps_pmtud_blackhole_activated_min_mss; /* BH at min MSS Count */
803 	uint64_t tcps_pmtud_blackhole_failed;		 /* Black Hole Failure Count */
804 
805 	uint64_t tcps_tunneled_pkts;	/* Packets encap's in UDP received */
806 	uint64_t tcps_tunneled_errs;	/* Packets that had errors that were UDP encaped */
807 
808 	/* Dsack related stats */
809 	uint64_t tcps_dsack_count;	/* Number of ACKs arriving with DSACKs */
810 	uint64_t tcps_dsack_bytes;	/* Number of bytes DSACK'ed no TLP */
811 	uint64_t tcps_dsack_tlp_bytes;	/* Number of bytes DSACK'ed due to TLPs */
812 
813 	/* TCPS_TIME_WAIT usage stats */
814 	uint64_t tcps_tw_recycles;	/* Times time-wait was recycled. */
815 	uint64_t tcps_tw_resets;	/* Times time-wait sent a reset. */
816 	uint64_t tcps_tw_responds;	/* Times time-wait sent a valid ack. */
817 
818 	uint64_t _pad[6];		/* 3 UTO, 3 TBD */
819 };
820 
821 #define	tcps_rcvmemdrop	tcps_rcvreassfull	/* compat */
822 
823 #ifdef _KERNEL
824 #define	TI_UNLOCKED	1
825 #define	TI_RLOCKED	2
826 #include <sys/counter.h>
827 
828 VNET_PCPUSTAT_DECLARE(struct tcpstat, tcpstat);	/* tcp statistics */
829 /*
830  * In-kernel consumers can use these accessor macros directly to update
831  * stats.
832  */
833 #define	TCPSTAT_ADD(name, val)	\
834     VNET_PCPUSTAT_ADD(struct tcpstat, tcpstat, name, (val))
835 #define	TCPSTAT_INC(name)	TCPSTAT_ADD(name, 1)
836 
837 /*
838  * Kernel module consumers must use this accessor macro.
839  */
840 void	kmod_tcpstat_add(int statnum, int val);
841 #define	KMOD_TCPSTAT_ADD(name, val)					\
842     kmod_tcpstat_add(offsetof(struct tcpstat, name) / sizeof(uint64_t), val)
843 #define	KMOD_TCPSTAT_INC(name)	KMOD_TCPSTAT_ADD(name, 1)
844 
845 /*
846  * Running TCP connection count by state.
847  */
848 VNET_DECLARE(counter_u64_t, tcps_states[TCP_NSTATES]);
849 #define	V_tcps_states	VNET(tcps_states)
850 #define	TCPSTATES_INC(state)	counter_u64_add(V_tcps_states[state], 1)
851 #define	TCPSTATES_DEC(state)	counter_u64_add(V_tcps_states[state], -1)
852 
853 /*
854  * TCP specific helper hook point identifiers.
855  */
856 #define	HHOOK_TCP_EST_IN		0
857 #define	HHOOK_TCP_EST_OUT		1
858 #define	HHOOK_TCP_LAST			HHOOK_TCP_EST_OUT
859 
860 struct tcp_hhook_data {
861 	struct tcpcb	*tp;
862 	struct tcphdr	*th;
863 	struct tcpopt	*to;
864 	uint32_t	len;
865 	int		tso;
866 	tcp_seq		curack;
867 };
868 #ifdef TCP_HHOOK
869 void hhook_run_tcp_est_out(struct tcpcb *tp,
870 	struct tcphdr *th, struct tcpopt *to,
871 	uint32_t len, int tso);
872 #endif
873 #endif
874 
875 /*
876  * TCB structure exported to user-land via sysctl(3).
877  *
878  * Fields prefixed with "xt_" are unique to the export structure, and fields
879  * with "t_" or other prefixes match corresponding fields of 'struct tcpcb'.
880  *
881  * Legend:
882  * (s) - used by userland utilities in src
883  * (p) - used by utilities in ports
884  * (3) - is known to be used by third party software not in ports
885  * (n) - no known usage
886  *
887  * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
888  * included.  Not all of our clients do.
889  */
890 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
891 struct xtcpcb {
892 	ksize_t	xt_len;		/* length of this structure */
893 	struct xinpcb	xt_inp;
894 	char		xt_stack[TCP_FUNCTION_NAME_LEN_MAX];	/* (s) */
895 	char		xt_logid[TCP_LOG_ID_LEN];	/* (s) */
896 	char		xt_cc[TCP_CA_NAME_MAX];	/* (s) */
897 	int64_t		spare64[6];
898 	int32_t		t_state;		/* (s,p) */
899 	uint32_t	t_flags;		/* (s,p) */
900 	int32_t		t_sndzerowin;		/* (s) */
901 	int32_t		t_sndrexmitpack;	/* (s) */
902 	int32_t		t_rcvoopack;		/* (s) */
903 	int32_t		t_rcvtime;		/* (s) */
904 	int32_t		tt_rexmt;		/* (s) */
905 	int32_t		tt_persist;		/* (s) */
906 	int32_t		tt_keep;		/* (s) */
907 	int32_t		tt_2msl;		/* (s) */
908 	int32_t		tt_delack;		/* (s) */
909 	int32_t		t_logstate;		/* (3) */
910 	uint32_t	t_snd_cwnd;		/* (s) */
911 	uint32_t	t_snd_ssthresh;		/* (s) */
912 	uint32_t	t_maxseg;		/* (s) */
913 	uint32_t	t_rcv_wnd;		/* (s) */
914 	uint32_t	t_snd_wnd;		/* (s) */
915 	uint32_t	xt_ecn;			/* (s) */
916 	uint32_t	t_dsack_bytes;		/* (n) */
917 	uint32_t	t_dsack_tlp_bytes;	/* (n) */
918 	uint32_t	t_dsack_pack;		/* (n) */
919 	uint16_t	xt_encaps_port;		/* (s) */
920 	int16_t		spare16;
921 	int32_t		spare32[22];
922 } __aligned(8);
923 
924 #ifdef _KERNEL
925 void	tcp_inptoxtp(const struct inpcb *, struct xtcpcb *);
926 #endif
927 #endif
928 
929 /*
930  * TCP function information (name-to-id mapping, aliases, and refcnt)
931  * exported to user-land via sysctl(3).
932  */
933 struct tcp_function_info {
934 	uint32_t	tfi_refcnt;
935 	uint8_t		tfi_id;
936 	char		tfi_name[TCP_FUNCTION_NAME_LEN_MAX];
937 	char		tfi_alias[TCP_FUNCTION_NAME_LEN_MAX];
938 };
939 
940 /*
941  * Identifiers for TCP sysctl nodes
942  */
943 #define	TCPCTL_DO_RFC1323	1	/* use RFC-1323 extensions */
944 #define	TCPCTL_MSSDFLT		3	/* MSS default */
945 #define TCPCTL_STATS		4	/* statistics */
946 #define	TCPCTL_RTTDFLT		5	/* default RTT estimate */
947 #define	TCPCTL_KEEPIDLE		6	/* keepalive idle timer */
948 #define	TCPCTL_KEEPINTVL	7	/* interval to send keepalives */
949 #define	TCPCTL_SENDSPACE	8	/* send buffer space */
950 #define	TCPCTL_RECVSPACE	9	/* receive buffer space */
951 #define	TCPCTL_KEEPINIT		10	/* timeout for establishing syn */
952 #define	TCPCTL_PCBLIST		11	/* list of all outstanding PCBs */
953 #define	TCPCTL_DELACKTIME	12	/* time before sending delayed ACK */
954 #define	TCPCTL_V6MSSDFLT	13	/* MSS default for IPv6 */
955 #define	TCPCTL_SACK		14	/* Selective Acknowledgement,rfc 2018 */
956 #define	TCPCTL_DROP		15	/* drop tcp connection */
957 #define	TCPCTL_STATES		16	/* connection counts by TCP state */
958 
959 #ifdef _KERNEL
960 #ifdef SYSCTL_DECL
961 SYSCTL_DECL(_net_inet_tcp);
962 SYSCTL_DECL(_net_inet_tcp_sack);
963 MALLOC_DECLARE(M_TCPLOG);
964 #endif
965 
966 VNET_DECLARE(int, tcp_log_in_vain);
967 #define	V_tcp_log_in_vain		VNET(tcp_log_in_vain)
968 
969 /*
970  * Global TCP tunables shared between different stacks.
971  * Please keep the list sorted.
972  */
973 VNET_DECLARE(int, drop_synfin);
974 VNET_DECLARE(int, path_mtu_discovery);
975 VNET_DECLARE(int, tcp_abc_l_var);
976 VNET_DECLARE(int, tcp_autorcvbuf_max);
977 VNET_DECLARE(int, tcp_autosndbuf_inc);
978 VNET_DECLARE(int, tcp_autosndbuf_max);
979 VNET_DECLARE(int, tcp_delack_enabled);
980 VNET_DECLARE(int, tcp_do_autorcvbuf);
981 VNET_DECLARE(int, tcp_do_autosndbuf);
982 VNET_DECLARE(int, tcp_do_ecn);
983 VNET_DECLARE(int, tcp_do_lrd);
984 VNET_DECLARE(int, tcp_do_prr);
985 VNET_DECLARE(int, tcp_do_prr_conservative);
986 VNET_DECLARE(int, tcp_do_newcwv);
987 VNET_DECLARE(int, tcp_do_rfc1323);
988 VNET_DECLARE(int, tcp_tolerate_missing_ts);
989 VNET_DECLARE(int, tcp_do_rfc3042);
990 VNET_DECLARE(int, tcp_do_rfc3390);
991 VNET_DECLARE(int, tcp_do_rfc3465);
992 VNET_DECLARE(int, tcp_do_newsack);
993 VNET_DECLARE(int, tcp_do_sack);
994 VNET_DECLARE(int, tcp_do_tso);
995 VNET_DECLARE(int, tcp_ecn_maxretries);
996 VNET_DECLARE(int, tcp_initcwnd_segments);
997 VNET_DECLARE(int, tcp_insecure_rst);
998 VNET_DECLARE(int, tcp_insecure_syn);
999 VNET_DECLARE(uint32_t, tcp_map_entries_limit);
1000 VNET_DECLARE(uint32_t, tcp_map_split_limit);
1001 VNET_DECLARE(int, tcp_minmss);
1002 VNET_DECLARE(int, tcp_mssdflt);
1003 #ifdef STATS
1004 VNET_DECLARE(int, tcp_perconn_stats_dflt_tpl);
1005 VNET_DECLARE(int, tcp_perconn_stats_enable);
1006 #endif /* STATS */
1007 VNET_DECLARE(int, tcp_recvspace);
1008 VNET_DECLARE(int, tcp_sack_globalholes);
1009 VNET_DECLARE(int, tcp_sack_globalmaxholes);
1010 VNET_DECLARE(int, tcp_sack_maxholes);
1011 VNET_DECLARE(int, tcp_sc_rst_sock_fail);
1012 VNET_DECLARE(int, tcp_sendspace);
1013 VNET_DECLARE(int, tcp_udp_tunneling_overhead);
1014 VNET_DECLARE(int, tcp_udp_tunneling_port);
1015 VNET_DECLARE(struct inpcbinfo, tcbinfo);
1016 
1017 #define	V_tcp_do_lrd			VNET(tcp_do_lrd)
1018 #define	V_tcp_do_prr			VNET(tcp_do_prr)
1019 #define	V_tcp_do_prr_conservative	VNET(tcp_do_prr_conservative)
1020 #define	V_tcp_do_newcwv			VNET(tcp_do_newcwv)
1021 #define	V_drop_synfin			VNET(drop_synfin)
1022 #define	V_path_mtu_discovery		VNET(path_mtu_discovery)
1023 #define	V_tcbinfo			VNET(tcbinfo)
1024 #define	V_tcp_abc_l_var			VNET(tcp_abc_l_var)
1025 #define	V_tcp_autorcvbuf_max		VNET(tcp_autorcvbuf_max)
1026 #define	V_tcp_autosndbuf_inc		VNET(tcp_autosndbuf_inc)
1027 #define	V_tcp_autosndbuf_max		VNET(tcp_autosndbuf_max)
1028 #define	V_tcp_delack_enabled		VNET(tcp_delack_enabled)
1029 #define	V_tcp_do_autorcvbuf		VNET(tcp_do_autorcvbuf)
1030 #define	V_tcp_do_autosndbuf		VNET(tcp_do_autosndbuf)
1031 #define	V_tcp_do_ecn			VNET(tcp_do_ecn)
1032 #define	V_tcp_do_rfc1323		VNET(tcp_do_rfc1323)
1033 #define	V_tcp_tolerate_missing_ts	VNET(tcp_tolerate_missing_ts)
1034 #define V_tcp_ts_offset_per_conn	VNET(tcp_ts_offset_per_conn)
1035 #define	V_tcp_do_rfc3042		VNET(tcp_do_rfc3042)
1036 #define	V_tcp_do_rfc3390		VNET(tcp_do_rfc3390)
1037 #define	V_tcp_do_rfc3465		VNET(tcp_do_rfc3465)
1038 #define	V_tcp_do_newsack		VNET(tcp_do_newsack)
1039 #define	V_tcp_do_sack			VNET(tcp_do_sack)
1040 #define	V_tcp_do_tso			VNET(tcp_do_tso)
1041 #define	V_tcp_ecn_maxretries		VNET(tcp_ecn_maxretries)
1042 #define	V_tcp_initcwnd_segments		VNET(tcp_initcwnd_segments)
1043 #define	V_tcp_insecure_rst		VNET(tcp_insecure_rst)
1044 #define	V_tcp_insecure_syn		VNET(tcp_insecure_syn)
1045 #define	V_tcp_map_entries_limit		VNET(tcp_map_entries_limit)
1046 #define	V_tcp_map_split_limit		VNET(tcp_map_split_limit)
1047 #define	V_tcp_minmss			VNET(tcp_minmss)
1048 #define	V_tcp_mssdflt			VNET(tcp_mssdflt)
1049 #ifdef STATS
1050 #define	V_tcp_perconn_stats_dflt_tpl	VNET(tcp_perconn_stats_dflt_tpl)
1051 #define	V_tcp_perconn_stats_enable	VNET(tcp_perconn_stats_enable)
1052 #endif /* STATS */
1053 #define	V_tcp_recvspace			VNET(tcp_recvspace)
1054 #define	V_tcp_sack_globalholes		VNET(tcp_sack_globalholes)
1055 #define	V_tcp_sack_globalmaxholes	VNET(tcp_sack_globalmaxholes)
1056 #define	V_tcp_sack_maxholes		VNET(tcp_sack_maxholes)
1057 #define	V_tcp_sc_rst_sock_fail		VNET(tcp_sc_rst_sock_fail)
1058 #define	V_tcp_sendspace			VNET(tcp_sendspace)
1059 #define	V_tcp_udp_tunneling_overhead	VNET(tcp_udp_tunneling_overhead)
1060 #define	V_tcp_udp_tunneling_port	VNET(tcp_udp_tunneling_port)
1061 
1062 #ifdef TCP_HHOOK
1063 VNET_DECLARE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST + 1]);
1064 #define	V_tcp_hhh		VNET(tcp_hhh)
1065 #endif
1066 
1067 int	 tcp_addoptions(struct tcpopt *, u_char *);
1068 int	 tcp_ccalgounload(struct cc_algo *unload_algo);
1069 struct tcpcb *
1070 	 tcp_close(struct tcpcb *);
1071 void	 tcp_discardcb(struct tcpcb *);
1072 bool	 tcp_freecb(struct tcpcb *);
1073 void	 tcp_twstart(struct tcpcb *);
1074 void	 tcp_twclose(struct tcptw *, int);
1075 void	 tcp_ctlinput(int, struct sockaddr *, void *);
1076 int	 tcp_ctloutput(struct socket *, struct sockopt *);
1077 void 	 tcp_ctlinput_viaudp(int, struct sockaddr *, void *, void *);
1078 void	 tcp_drain(void);
1079 void	 tcp_fini(void *);
1080 char	*tcp_log_addrs(struct in_conninfo *, struct tcphdr *, void *,
1081 	    const void *);
1082 char	*tcp_log_vain(struct in_conninfo *, struct tcphdr *, void *,
1083 	    const void *);
1084 int	 tcp_reass(struct tcpcb *, struct tcphdr *, tcp_seq *, int *,
1085 	    struct mbuf *);
1086 void	 tcp_reass_global_init(void);
1087 void	 tcp_reass_flush(struct tcpcb *);
1088 void	 tcp_dooptions(struct tcpopt *, u_char *, int, int);
1089 void	tcp_dropwithreset(struct mbuf *, struct tcphdr *,
1090 		     struct tcpcb *, int, int);
1091 void	tcp_pulloutofband(struct socket *,
1092 		     struct tcphdr *, struct mbuf *, int);
1093 void	tcp_xmit_timer(struct tcpcb *, int);
1094 void	tcp_newreno_partial_ack(struct tcpcb *, struct tcphdr *);
1095 void	cc_ack_received(struct tcpcb *tp, struct tcphdr *th,
1096 			    uint16_t nsegs, uint16_t type);
1097 void 	cc_conn_init(struct tcpcb *tp);
1098 void 	cc_post_recovery(struct tcpcb *tp, struct tcphdr *th);
1099 void    cc_ecnpkt_handler(struct tcpcb *tp, struct tcphdr *th, uint8_t iptos);
1100 void	cc_ecnpkt_handler_flags(struct tcpcb *tp, uint16_t flags, uint8_t iptos);
1101 void	cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type);
1102 #ifdef TCP_HHOOK
1103 void	hhook_run_tcp_est_in(struct tcpcb *tp,
1104 			    struct tcphdr *th, struct tcpopt *to);
1105 #endif
1106 
1107 int	 tcp_input(struct mbuf **, int *, int);
1108 int	 tcp_autorcvbuf(struct mbuf *, struct tcphdr *, struct socket *,
1109 	    struct tcpcb *, int);
1110 int	 tcp_input_with_port(struct mbuf **, int *, int, uint16_t);
1111 void	 tcp_handle_wakeup(struct tcpcb *, struct socket *);
1112 void	 tcp_do_segment(struct mbuf *, struct tcphdr *,
1113 			struct socket *, struct tcpcb *, int, int, uint8_t);
1114 
1115 int register_tcp_functions(struct tcp_function_block *blk, int wait);
1116 int register_tcp_functions_as_names(struct tcp_function_block *blk,
1117     int wait, const char *names[], int *num_names);
1118 int register_tcp_functions_as_name(struct tcp_function_block *blk,
1119     const char *name, int wait);
1120 int deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce,
1121     bool force);
1122 struct tcp_function_block *find_and_ref_tcp_functions(struct tcp_function_set *fs);
1123 int find_tcp_function_alias(struct tcp_function_block *blk, struct tcp_function_set *fs);
1124 void tcp_switch_back_to_default(struct tcpcb *tp);
1125 struct tcp_function_block *
1126 find_and_ref_tcp_fb(struct tcp_function_block *fs);
1127 int tcp_default_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp);
1128 
1129 extern counter_u64_t tcp_inp_lro_direct_queue;
1130 extern counter_u64_t tcp_inp_lro_wokeup_queue;
1131 extern counter_u64_t tcp_inp_lro_compressed;
1132 extern counter_u64_t tcp_inp_lro_locks_taken;
1133 extern counter_u64_t tcp_extra_mbuf;
1134 extern counter_u64_t tcp_would_have_but;
1135 extern counter_u64_t tcp_comp_total;
1136 extern counter_u64_t tcp_uncomp_total;
1137 extern counter_u64_t tcp_bad_csums;
1138 
1139 #ifdef NETFLIX_EXP_DETECTION
1140 /* Various SACK attack thresholds */
1141 extern int32_t tcp_force_detection;
1142 extern int32_t tcp_sack_to_ack_thresh;
1143 extern int32_t tcp_sack_to_move_thresh;
1144 extern int32_t tcp_restoral_thresh;
1145 extern int32_t tcp_sad_decay_val;
1146 extern int32_t tcp_sad_pacing_interval;
1147 extern int32_t tcp_sad_low_pps;
1148 extern int32_t tcp_map_minimum;
1149 extern int32_t tcp_attack_on_turns_on_logging;
1150 #endif
1151 extern uint32_t tcp_ack_war_time_window;
1152 extern uint32_t tcp_ack_war_cnt;
1153 
1154 uint32_t tcp_maxmtu(struct in_conninfo *, struct tcp_ifcap *);
1155 uint32_t tcp_maxmtu6(struct in_conninfo *, struct tcp_ifcap *);
1156 void	 tcp6_use_min_mtu(struct tcpcb *);
1157 u_int	 tcp_maxseg(const struct tcpcb *);
1158 u_int	 tcp_fixed_maxseg(const struct tcpcb *);
1159 void	 tcp_mss_update(struct tcpcb *, int, int, struct hc_metrics_lite *,
1160 	    struct tcp_ifcap *);
1161 void	 tcp_mss(struct tcpcb *, int);
1162 int	 tcp_mssopt(struct in_conninfo *);
1163 struct inpcb *
1164 	 tcp_drop_syn_sent(struct inpcb *, int);
1165 struct tcpcb *
1166 	 tcp_newtcpcb(struct inpcb *);
1167 int	 tcp_default_output(struct tcpcb *);
1168 void	 tcp_state_change(struct tcpcb *, int);
1169 void	 tcp_respond(struct tcpcb *, void *,
1170 	    struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
1171 void	 tcp_tw_init(void);
1172 #ifdef VIMAGE
1173 void	 tcp_tw_destroy(void);
1174 #endif
1175 void	 tcp_tw_zone_change(void);
1176 int	 tcp_twcheck(struct inpcb *, struct tcpopt *, struct tcphdr *,
1177 	    struct mbuf *, int);
1178 void	 tcp_setpersist(struct tcpcb *);
1179 void	 tcp_slowtimo(void);
1180 void	 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp);
1181 struct tcptemp *
1182 	 tcpip_maketemplate(struct inpcb *);
1183 void	 tcpip_fillheaders(struct inpcb *, uint16_t, void *, void *);
1184 void	 tcp_timer_activate(struct tcpcb *, uint32_t, u_int);
1185 int	 tcp_timer_suspend(struct tcpcb *, uint32_t);
1186 void	 tcp_timers_unsuspend(struct tcpcb *, uint32_t);
1187 int	 tcp_timer_active(struct tcpcb *, uint32_t);
1188 void	 tcp_timer_stop(struct tcpcb *, uint32_t);
1189 void	 tcp_trace(short, short, struct tcpcb *, void *, struct tcphdr *, int);
1190 int	 inp_to_cpuid(struct inpcb *inp);
1191 /*
1192  * All tcp_hc_* functions are IPv4 and IPv6 (via in_conninfo)
1193  */
1194 void	 tcp_hc_init(void);
1195 #ifdef VIMAGE
1196 void	 tcp_hc_destroy(void);
1197 #endif
1198 void	 tcp_hc_get(struct in_conninfo *, struct hc_metrics_lite *);
1199 uint32_t tcp_hc_getmtu(struct in_conninfo *);
1200 void	 tcp_hc_updatemtu(struct in_conninfo *, uint32_t);
1201 void	 tcp_hc_update(struct in_conninfo *, struct hc_metrics_lite *);
1202 
1203 extern	struct pr_usrreqs tcp_usrreqs;
1204 
1205 uint32_t tcp_new_ts_offset(struct in_conninfo *);
1206 tcp_seq	 tcp_new_isn(struct in_conninfo *);
1207 
1208 int	 tcp_sack_doack(struct tcpcb *, struct tcpopt *, tcp_seq);
1209 int	 tcp_dsack_block_exists(struct tcpcb *);
1210 void	 tcp_update_dsack_list(struct tcpcb *, tcp_seq, tcp_seq);
1211 void	 tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend);
1212 void	 tcp_clean_dsack_blocks(struct tcpcb *tp);
1213 void	 tcp_clean_sackreport(struct tcpcb *tp);
1214 void	 tcp_sack_adjust(struct tcpcb *tp);
1215 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt);
1216 void	 tcp_do_prr_ack(struct tcpcb *, struct tcphdr *, struct tcpopt *);
1217 void	 tcp_lost_retransmission(struct tcpcb *, struct tcphdr *);
1218 void	 tcp_sack_partialack(struct tcpcb *, struct tcphdr *);
1219 void	 tcp_free_sackholes(struct tcpcb *tp);
1220 void	 tcp_sack_lost_retransmission(struct tcpcb *, struct tcphdr *);
1221 int	 tcp_newreno(struct tcpcb *, struct tcphdr *);
1222 int	 tcp_compute_pipe(struct tcpcb *);
1223 uint32_t tcp_compute_initwnd(uint32_t);
1224 void	 tcp_sndbuf_autoscale(struct tcpcb *, struct socket *, uint32_t);
1225 int	 tcp_stats_sample_rollthedice(struct tcpcb *tp, void *seed_bytes,
1226     size_t seed_len);
1227 int tcp_can_enable_pacing(void);
1228 void tcp_decrement_paced_conn(void);
1229 
1230 struct mbuf *
1231 	 tcp_m_copym(struct mbuf *m, int32_t off0, int32_t *plen,
1232 	   int32_t seglimit, int32_t segsize, struct sockbuf *sb, bool hw_tls);
1233 
1234 int	tcp_stats_init(void);
1235 void tcp_log_end_status(struct tcpcb *tp, uint8_t status);
1236 
1237 static inline void
1238 tcp_fields_to_host(struct tcphdr *th)
1239 {
1240 
1241 	th->th_seq = ntohl(th->th_seq);
1242 	th->th_ack = ntohl(th->th_ack);
1243 	th->th_win = ntohs(th->th_win);
1244 	th->th_urp = ntohs(th->th_urp);
1245 }
1246 
1247 static inline void
1248 tcp_fields_to_net(struct tcphdr *th)
1249 {
1250 
1251 	th->th_seq = htonl(th->th_seq);
1252 	th->th_ack = htonl(th->th_ack);
1253 	th->th_win = htons(th->th_win);
1254 	th->th_urp = htons(th->th_urp);
1255 }
1256 
1257 static inline void
1258 tcp_account_for_send(struct tcpcb *tp, uint32_t len, uint8_t is_rxt,
1259     uint8_t is_tlp, int hw_tls)
1260 {
1261 	if (is_tlp) {
1262 		tp->t_sndtlppack++;
1263 		tp->t_sndtlpbyte += len;
1264 	}
1265 	/* To get total bytes sent you must add t_snd_rxt_bytes to t_sndbytes */
1266 	if (is_rxt)
1267 		tp->t_snd_rxt_bytes += len;
1268 	else
1269 		tp->t_sndbytes += len;
1270 
1271 #ifdef KERN_TLS
1272 	if (hw_tls && is_rxt && len != 0) {
1273 		uint64_t rexmit_percent = (1000ULL * tp->t_snd_rxt_bytes) / (10ULL * (tp->t_snd_rxt_bytes + tp->t_sndbytes));
1274 		if (rexmit_percent > ktls_ifnet_max_rexmit_pct)
1275 			ktls_disable_ifnet(tp);
1276 	}
1277 #endif
1278 
1279 }
1280 #endif /* _KERNEL */
1281 
1282 #endif /* _NETINET_TCP_VAR_H_ */
1283