xref: /xnu-10002.1.13/bsd/netinet/tcp_var.h (revision 1031c584a5e37aff177559b9f69dbd3c8c3fd30a)
1 /*
2  * Copyright (c) 2000-2022 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
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8  * Version 2.0 (the 'License'). You may not use this file except in
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13  * terms of an Apple operating system software license agreement.
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15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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27  */
28 /*
29  * Copyright (c) 1982, 1986, 1993, 1994, 1995
30  *	The Regents of the University of California.  All rights reserved.
31  *
32  * Redistribution and use in source and binary forms, with or without
33  * modification, are permitted provided that the following conditions
34  * are met:
35  * 1. Redistributions of source code must retain the above copyright
36  *    notice, this list of conditions and the following disclaimer.
37  * 2. Redistributions in binary form must reproduce the above copyright
38  *    notice, this list of conditions and the following disclaimer in the
39  *    documentation and/or other materials provided with the distribution.
40  * 3. All advertising materials mentioning features or use of this software
41  *    must display the following acknowledgement:
42  *	This product includes software developed by the University of
43  *	California, Berkeley and its contributors.
44  * 4. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)tcp_var.h	8.4 (Berkeley) 5/24/95
61  * $FreeBSD: src/sys/netinet/tcp_var.h,v 1.56.2.8 2001/08/22 00:59:13 silby Exp $
62  */
63 
64 #ifndef _NETINET_TCP_VAR_H_
65 #define _NETINET_TCP_VAR_H_
66 #include <sys/types.h>
67 #include <sys/appleapiopts.h>
68 #include <sys/queue.h>
69 #include <netinet/in_pcb.h>
70 #include <netinet/tcp.h>
71 #include <netinet/tcp_timer.h>
72 #if !KERNEL
73 #include <TargetConditionals.h>
74 #endif
75 
76 #if defined(__LP64__)
77 #define _TCPCB_PTR(x)                   u_int32_t
78 #define _TCPCB_LIST_HEAD(name, type)    \
79 struct name {                           \
80 	u_int32_t	lh_first;       \
81 }
82 #else
83 #define _TCPCB_PTR(x)                   x
84 #define _TCPCB_LIST_HEAD(name, type)    LIST_HEAD(name, type)
85 #endif
86 
87 #ifdef KERNEL_PRIVATE
88 
89 #define TCP_RETRANSHZ   1000    /* granularity of TCP timestamps, 1ms */
90 /* Minimum time quantum within which the timers are coalesced */
91 #define TCP_TIMER_10MS_QUANTUM  (TCP_RETRANSHZ/100) /* every 10ms */
92 #define TCP_TIMER_100MS_QUANTUM   (TCP_RETRANSHZ/10) /* every 100ms */
93 #define TCP_TIMER_500MS_QUANTUM   (TCP_RETRANSHZ/2) /* every 500ms */
94 
95 #define TCP_RETRANSHZ_TO_USEC 1000
96 
97 #define N_TIME_WAIT_SLOTS   128         /* must be power of 2 */
98 
99 /* Always allow at least 16 packets worth of recv window when adjusting
100  * recv window using inter-packet arrival jitter.
101  */
102 #define MIN_IAJ_WIN 16
103 
104 /* A variation in delay of this many milliseconds is tolerable. This limit has to
105  * be low but greater than zero. We also use standard deviation on jitter to adjust
106  * this limit for different link and connection types.
107  */
108 #define ALLOWED_IAJ 5
109 
110 /* Ignore the first few packets on a connection until the ACK clock gets going
111  */
112 #define IAJ_IGNORE_PKTCNT 40
113 
114 /* Let the accumulated IAJ value increase by this threshold at most. This limit
115  * will control how many ALLOWED_IAJ measurements a receiver will have to see
116  * before opening the receive window
117  */
118 #define ACC_IAJ_HIGH_THRESH 100
119 
120 /* When accumulated IAJ reaches this value, the receiver starts to react by
121  * closing the window
122  */
123 #define ACC_IAJ_REACT_LIMIT 200
124 
125 /* If the number of small packets (smaller than IAJ packet size) seen on a
126  * connection is more than this threshold, reset the size and learn it again.
127  * This is needed because the sender might send smaller segments after PMTU
128  * discovery and the receiver has to learn the new size.
129  */
130 #define RESET_IAJ_SIZE_THRESH 20
131 
132 /*
133  * Adaptive timeout is a read/write timeout specified by the application to
134  * get a socket event when the transport layer detects a stall in data
135  * transfer. The value specified is the number of probes that can be sent
136  * to the peer before generating an event. Since it is not specified as
137  * a time value, the timeout will adjust based on the RTT seen on the link.
138  * The timeout will start only when there is an indication that the read/write
139  * operation is not making progress.
140  *
141  * If a write operation stalls, the probe will be retransmission of data.
142  * If a read operation stalls, the probe will be a keep-alive packet.
143  *
144  * The maximum value of adaptive timeout is set to 10 which will allow
145  * transmission of enough number of probes to the peer.
146  */
147 #define TCP_ADAPTIVE_TIMEOUT_MAX        10
148 
149 #define TCP_CONNECTIVITY_PROBES_MAX     5
150 
151 /* 3 bit mask used for Accurate ECN ACE field */
152 #define TCP_ACE_MASK (0x7)
153 /* Divisor used for Accurate ECN ACE field */
154 #define TCP_ACE_DIV (1 << 3)
155 
156 /* 24 bit mask used for Accurate ECN option */
157 #define TCP_ACO_MASK (0xFFFFFF)
158 
159 /*
160  * Kernel variables for tcp.
161  */
162 
163 /* TCP segment queue entry */
164 struct tseg_qent {
165 	LIST_ENTRY(tseg_qent) tqe_q;
166 	int     tqe_len;                /* TCP segment data length */
167 	struct  tcphdr *tqe_th;         /* a pointer to tcp header */
168 	struct  mbuf    *tqe_m;         /* mbuf contains packet */
169 };
170 LIST_HEAD(tsegqe_head, tseg_qent);
171 
172 struct sackblk {
173 	tcp_seq start;          /* start seq no. of sack block */
174 	tcp_seq end;            /* end seq no. */
175 };
176 
177 struct sackhole {
178 	tcp_seq start;          /* start seq no. of hole */
179 	tcp_seq end;            /* end seq no. */
180 	tcp_seq rxmit;          /* next seq. no in hole to be retransmitted */
181 	u_int32_t rxmit_start;  /* timestamp of first retransmission */
182 	TAILQ_ENTRY(sackhole) scblink;  /* scoreboard linkage */
183 };
184 
185 struct sackhint {
186 	struct sackhole *nexthole;
187 	int     sack_bytes_rexmit;
188 	int sack_bytes_acked;
189 };
190 
191 struct tcp_rxt_seg {
192 	tcp_seq rx_start;
193 	tcp_seq rx_end;
194 	u_int16_t rx_count;
195 	u_int16_t rx_flags;
196 #define TCP_RXT_SPURIOUS        0x1     /* received DSACK notification */
197 	SLIST_ENTRY(tcp_rxt_seg) rx_link;
198 };
199 
200 struct tcp_notify_ack_marker {
201 	tcp_seq notify_snd_una; /* Notify when snd_una crosses this seq */
202 	tcp_notify_ack_id_t notify_id;
203 	SLIST_ENTRY(tcp_notify_ack_marker) notify_next;
204 };
205 
206 struct tcptemp {
207 	u_char  tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
208 	struct  tcphdr tt_t;
209 };
210 
211 struct bwmeas {
212 	tcp_seq bw_start;       /* start of bw measurement */
213 	uint32_t bw_ts;         /* timestamp when bw measurement started */
214 	uint32_t bw_size;       /* burst size in bytes for this bw measurement */
215 	uint32_t bw_minsizepkts; /* Min burst size as segments */
216 	uint32_t bw_maxsizepkts; /* Max burst size as segments */
217 	uint32_t bw_minsize;    /* Min size in bytes */
218 	uint32_t bw_maxsize;    /* Max size in bytes */
219 	uint32_t bw_sndbw;      /* Measured send bandwidth */
220 	uint32_t bw_sndbw_max;  /* Max measured bandwidth */
221 	uint32_t bw_rcvbw_max;  /* Max receive bandwidth measured */
222 };
223 
224 /* MPTCP Data sequence map entry */
225 struct mpt_dsn_map {
226 	uint64_t                mpt_dsn;        /* data seq num recvd */
227 	uint32_t                mpt_sseq;       /* relative subflow # */
228 	uint16_t                mpt_len;        /* length of mapping */
229 	uint16_t                mpt_csum;       /* checksum value if on */
230 	uint8_t                 mpt_dfin;       /* It's a DATA_FIN */
231 };
232 #define tcp6cb          tcpcb  /* for KAME src sync over BSD*'s */
233 
234 struct tcp_ccstate {
235 	union {
236 		struct tcp_cubic_state {
237 			u_int32_t tc_last_max;  /* cwnd at last loss */
238 			u_int32_t tc_epoch_start; /* TS of last loss */
239 			u_int32_t tc_origin_point; /* window at the start of an epoch */
240 			u_int32_t tc_tcp_win; /* computed tcp win */
241 			u_int32_t tc_tcp_bytes_acked; /* bytes acked */
242 			u_int32_t tc_avg_lastmax; /* Average of last max */
243 			u_int32_t tc_mean_deviation; /* Mean absolute deviation */
244 			float     tc_epoch_period; /* K parameter */
245 		} _cubic_state_;
246 #define cub_last_max __u__._cubic_state_.tc_last_max
247 #define cub_epoch_start __u__._cubic_state_.tc_epoch_start
248 #define cub_origin_point __u__._cubic_state_.tc_origin_point
249 #define cub_tcp_win __u__._cubic_state_.tc_tcp_win
250 #define cub_tcp_bytes_acked __u__._cubic_state_.tc_tcp_bytes_acked
251 #define cub_epoch_period __u__._cubic_state_.tc_epoch_period
252 #define cub_avg_lastmax __u__._cubic_state_.tc_avg_lastmax
253 #define cub_mean_dev __u__._cubic_state_.tc_mean_deviation
254 		struct tcp_ledbat_state {
255 			uint32_t num_slowdown_events;
256 			uint32_t slowdown_ts;
257 			uint32_t slowdown_begin;
258 			uint32_t md_bytes_acked;
259 		} _ledbat_state_;
260 #define ledbat_slowdown_events __u__._ledbat_state_.num_slowdown_events
261 #define ledbat_slowdown_ts __u__._ledbat_state_.slowdown_ts
262 #define ledbat_slowdown_begin __u__._ledbat_state_.slowdown_begin
263 #define ledbat_md_bytes_acked __u__._ledbat_state_.md_bytes_acked
264 	} __u__;
265 };
266 
267 struct tcp_rledbat_state {
268 	uint32_t num_slowdown_events;  /* Number of slowdown events until reset */
269 	uint32_t slowdown_ts;          /* Next slowdown timestamp */
270 	uint32_t slowdown_begin;       /* Slowdown begin time */
271 	uint32_t reduction_end;        /* Used to track rl_win reduction once per RTT */
272 	uint32_t rcvd_bytes;           /* bytes received used for byte counting */
273 	uint32_t md_rcvd_bytes;        /* bytes received during MD used for byte counting */
274 	uint32_t win;                  /* receive Ledbat window size */
275 	uint32_t ssthresh;             /* receive Ledbat ssthresh */
276 	uint32_t drained_bytes;        /* bytes drained from the flight-size */
277 	uint32_t win_ws;               /* receive Ledbat window after avoiding window shrinking */
278 };
279 
280 /*
281  * Tcp control block, one per tcp; fields:
282  * Organized for 16 byte cacheline efficiency.
283  */
284 struct tcpcb {
285 	struct tsegqe_head t_segq;
286 	uint32_t t_dupacks;             /* consecutive dup acks recd */
287 	int      t_state;               /* state of this connection */
288 	uint32_t t_timer[TCPT_NTIMERS]; /* tcp timers */
289 	struct tcptimerentry tentry;    /* entry in timer list */
290 
291 	struct  inpcb *t_inpcb;         /* back pointer to internet pcb */
292 	uint32_t        t_flags;
293 #define TF_ACKNOW       0x00001         /* ack peer immediately */
294 #define TF_DELACK       0x00002         /* ack, but try to delay it */
295 #define TF_NODELAY      0x00004         /* don't delay packets to coalesce */
296 #define TF_NOOPT        0x00008         /* don't use tcp options */
297 #define TF_SENTFIN      0x00010         /* have sent FIN */
298 #define TF_REQ_SCALE    0x00020         /* have/will request window scaling */
299 #define TF_RCVD_SCALE   0x00040         /* other side has requested scaling */
300 #define TF_REQ_TSTMP    0x00080         /* have/will request timestamps */
301 #define TF_RCVD_TSTMP   0x00100         /* a timestamp was received in SYN */
302 #define TF_SACK_PERMIT  0x00200         /* other side said I could SACK */
303 #define TF_NEEDSYN      0x00400         /* send SYN (implicit state) - unused but needed for backwards compatibility */
304 #define TF_NEEDFIN      0x00800         /* send FIN (implicit state) */
305 #define TF_NOPUSH       0x01000         /* don't push */
306 #define TF_REQ_CC       0x02000         /* have/will request CC */
307 #define TF_RCVD_CC      0x04000         /* a CC was received in SYN */
308 #define TF_SENDCCNEW    0x08000         /* Unused */
309 #define TF_MORETOCOME   0x10000         /* More data to be appended to sock */
310 #define TF_LOCAL        0x20000         /* connection to a host on local link */
311 #define TF_RXWIN0SENT   0x40000         /* sent a receiver win 0 in response */
312 #define TF_SLOWLINK     0x80000         /* route is a on a modem speed link */
313 #define TF_LASTIDLE     0x100000        /* connection was previously idle */
314 #define TF_FASTRECOVERY 0x200000        /* in NewReno Fast Recovery */
315 #define TF_WASFRECOVERY 0x400000        /* was in NewReno Fast Recovery */
316 #define TF_SIGNATURE    0x800000        /* require MD5 digests (RFC2385) */
317 #define TF_MAXSEGSNT    0x1000000       /* last segment sent was a full segment */
318 #define TF_STREAMING_ON 0x2000000       /* Receiver detected streaming */
319 #define TF_PMTUD        0x4000000       /* Perform Path MTU Discovery for this connection */
320 #define TF_CLOSING      0x8000000       /* pending tcp close */
321 #define TF_TSO          0x10000000      /* TCP Segment Offloading is enable on this connection */
322 #define TF_BLACKHOLE    0x20000000      /* Path MTU Discovery Black Hole detection */
323 #define TF_TIMER_ONLIST 0x40000000      /* pcb is on tcp_timer_list */
324 #define TF_STRETCHACK   0x80000000      /* receiver is going to delay acks */
325 
326 	tcp_seq snd_una;                /* send unacknowledged */
327 	tcp_seq snd_max;                /* highest sequence number sent;
328 	                                 * used to recognize retransmits
329 	                                 */
330 	tcp_seq snd_nxt;                /* send next */
331 	tcp_seq snd_up;                 /* send urgent pointer */
332 
333 	tcp_seq snd_wl1;                /* window update seg seq number */
334 	tcp_seq snd_wl2;                /* window update seg ack number */
335 	tcp_seq iss;                    /* initial send sequence number */
336 	tcp_seq irs;                    /* initial receive sequence number */
337 
338 	tcp_seq rcv_nxt;                /* receive next */
339 	tcp_seq rcv_adv;                /* advertised window */
340 	uint32_t        rcv_wnd;        /* receive window */
341 	uint32_t        t_last_recwin;
342 	tcp_seq rcv_up;                 /* receive urgent pointer */
343 
344 	uint32_t        snd_wnd;        /* send window */
345 	uint32_t        snd_cwnd;       /* congestion-controlled window */
346 	uint32_t        snd_ssthresh;   /* snd_cwnd size threshold for
347 	                                 * for slow start exponential to
348 	                                 * linear switch
349 	                                 */
350 	tcp_seq snd_recover;            /* for use in NewReno Fast Recovery */
351 
352 	uint32_t        t_maxopd;       /* mss plus options */
353 	uint32_t        t_rcvtime;      /* time at which a packet was received */
354 	uint32_t        t_sndtime;      /* time at which we last sent new data */
355 	uint32_t        t_starttime;    /* time connection was established */
356 	int     t_rtttime;              /* tcp clock when rtt calculation was started */
357 	tcp_seq t_rtseq;                /* sequence number being timed */
358 
359 	uint32_t rfbuf_ts;              /* recv buffer autoscaling timestamp */
360 	uint32_t rfbuf_cnt;             /* recv buffer autoscaling byte count */
361 	uint32_t rfbuf_space;           /* Current "ideal" estimate of the space */
362 
363 	int            t_rxtcur;        /* current retransmit value (ticks) */
364 	unsigned int   t_maxseg;        /* maximum segment size */
365 	int            t_srtt;          /* smoothed round-trip time */
366 	int            t_rttvar;        /* variance in round-trip time */
367 
368 	uint64_t t_accsleep_ms;         /* accumulated sleep time since last boot */
369 	uint32_t t_reassqlen;           /* length of reassembly queue */
370 	uint32_t t_reassq_mbcnt;        /* amount in bytes of mbuf space used */
371 	uint16_t t_rxtshift;            /* log(2) of rexmt exp. backoff */
372 	uint32_t t_rttmin;              /* minimum rtt allowed */
373 	uint32_t t_rttbest;             /* best rtt we've seen */
374 	uint32_t t_rttcur;              /* most recent value of rtt */
375 	uint32_t t_rttupdated;          /* number of times rtt sampled */
376 	uint32_t t_rxt_conndroptime;    /* retxmt conn gets dropped after this time, when set */
377 	uint32_t t_rxtstart;            /* time at which retransmission started */
378 	uint32_t max_sndwnd;            /* largest window peer has offered */
379 
380 	int     t_softerror;            /* possible error not yet reported */
381 /* out-of-band data */
382 	char    t_oobflags;             /* have some */
383 	char    t_iobc;                 /* input character */
384 #define TCPOOB_HAVEDATA 0x01
385 #define TCPOOB_HADDATA  0x02
386 /* RFC 1323 variables */
387 	u_int8_t        snd_scale;      /* window scaling for send window */
388 	u_int8_t        rcv_scale;      /* window scaling for recv window */
389 	u_int8_t        request_r_scale; /* pending window scaling */
390 	u_int8_t        requested_s_scale;
391 	u_int8_t        tcp_cc_index;   /* index of congestion control algorithm */
392 	u_int8_t        t_adaptive_rtimo;       /* Read timeout used as a multiple of RTT */
393 	u_int8_t        t_adaptive_wtimo;       /* Write timeout used as a multiple of RTT */
394 	u_int8_t        t_stretchack_delayed;   /* stretch ack delayed */
395 
396 /* State for limiting early retransmits when SACK is not enabled */
397 	u_int16_t       t_early_rexmt_count; /* count of early rexmts */
398 	u_int32_t       t_early_rexmt_win; /* window for limiting early rexmts */
399 
400 	u_int32_t       ts_recent;      /* timestamp echo data */
401 
402 	u_int32_t       ts_recent_age;  /* when last updated */
403 	tcp_seq last_ack_sent;
404 /* RFC 3465 variables */
405 	u_int32_t       t_bytes_acked;  /* ABC "bytes_acked" parameter */
406 
407 	int             t_lastchain;    /* amount of packets chained last time around */
408 	uint16_t        t_unacksegs;    /* received but unacked segments for delaying acks */
409 	uint16_t        t_unacksegs_ce; /* received but unacked segments/pure ACKs that were CE marked */
410 
411 	/*
412 	 * Pretty arbitrary value ;-)
413 	 * Goal is to make sure that some ACKs are being sent more frequently
414 	 * to allow the other side to ramp-up.
415 	 */
416 #define TCP_FORCED_ACKS_COUNT 16
417 	uint16_t        t_forced_acks;  /* count of pure ACKs that need to be forced out */
418 	uint8_t         t_rexmtthresh;  /* duplicate ack threshold for entering fast recovery */
419 	uint8_t         t_rtimo_probes; /* number of adaptive rtimo probes sent */
420 	uint32_t        t_persist_timeout; /* ZWP persistence limit as set by PERSIST_TIMEOUT */
421 	uint32_t        t_persist_stop;    /* persistence limit deadline if triggered by ZWP */
422 	uint32_t        t_notsent_lowat;   /* Low water for not sent data */
423 
424 /* Receiver state for stretch-ack algorithm */
425 	u_int32_t       rcv_unackwin;   /* to measure win for stretching acks */
426 	u_int32_t       rcv_by_unackwin; /* bytes seen during the last ack-stretching win */
427 	u_int32_t       rcv_by_unackhalfwin;
428 	u_int32_t       rcv_nostrack_ts; /* timestamp when stretch ack was disabled automatically */
429 	u_int32_t       rcv_nostrack_pkts; /* pkts received since strech ack was disabled */
430 	u_int16_t       rcv_waitforss;  /* wait for packets during slow-start */
431 
432 /* ECN stats */
433 	u_int32_t       ecn_flags;
434 #define TE_SETUPSENT            0x00000001  /* We have sent classic ECN-SETUP SYN or SYN-ACK */
435 #define TE_SETUPRECEIVED        0x00000002  /* We have received classic ECN-SETUP SYN or SYN-ACK */
436 #define TE_SENDIPECT            0x00000004  /* We haven't sent or received non-ECN-setup SYN or SYN-ACK, set IP ECT on outbound packet */
437 #define TE_SENDCWR              0x00000008  /* Next non-retransmit should have TCP CWR set, only used for classic ECN */
438 #define TE_SENDECE              0x00000010  /* Next packet should have TCP ECE set, only used for classic ECN */
439 #define TE_INRECOVERY           0x00000020  /* connection entered recovery after receiving ECE */
440 #define TE_RECV_ECN_CE          0x00000040  /* Received IPTOS_ECN_CE marking atleast once */
441 #define TE_RECV_ECN_ECE         0x00000080  /* Received ECE marking atleast once */
442 #define TE_LOST_SYN             0x00000100  /* Lost SYN with ECN setup */
443 #define TE_LOST_SYNACK          0x00000200  /* Lost SYN-ACK with ECN setup */
444 #define TE_ECN_MODE_ENABLE      0x00000400  /* Option ECN mode set to enable */
445 #define TE_ECN_MODE_DISABLE     0x00000800  /* Option ECN mode set to disable */
446 #define TE_ENABLE_ECN           0x00001000  /* Enable negotiation of ECN */
447 #define TE_ECN_ON               (TE_SETUPSENT | TE_SETUPRECEIVED) /* ECN was successfully negotiated on a connection */
448 #define TE_CEHEURI_SET          0x00002000  /* We did our CE-probing at the beginning */
449 #define TE_CLIENT_SETUP         0x00004000  /* setup from client side */
450 #define TE_RCVD_SYN_RST         0x00008000  /* Received RST to the first ECN enabled SYN */
451 #define TE_ACE_SETUP_NON_ECT    0x00010000  /* Encode received non-ECT either for SYN-ACK (server) or final ACK (client) */
452 #define TE_ACE_SETUP_ECT1       0x00020000  /* Encode received ECT1 either for SYN-ACK (server) or final ACK (client) */
453 #define TE_ACE_SETUP_ECT0       0x00040000  /* Encode received ECT0 either for SYN-ACK (server) or final ACK (client) */
454 #define TE_ACE_SETUP_CE         0x00080000  /* Encode received CE either for SYN-ACK (server) or final ACK (client) */
455 #define TE_ACE_SETUPSENT        0x00100000  /* We have sent Accurate ECN setup SYN or SYN-ACK */
456 #define TE_ACE_SETUPRECEIVED    0x00200000  /* We have received Accurate ECN setup SYN or SYN-ACK */
457 #define TE_ACC_ECN_ON          (TE_ACE_SETUPSENT | TE_ACE_SETUPRECEIVED) /* Accurate ECN was negotiated */
458 #define TE_ACE_FINAL_ACK_3WHS   0x00400000  /* Client has received SYN-ACK and will now send final ACK of 3WHS, only used for AccECN */
459 #define TE_ACO_ECT1             0x00800000  /* ECT1 counter changed flag, used to decide ordering for AccECN option */
460 #define TE_ACO_ECT0             0x01000000  /* ECT0 counter changed flag, used to decide ordering for AccECN option */
461 #define TE_RETRY_WITHOUT_ACO    0x02000000  /* Data segment with AccECN option was not acknowledged, retry without AccECN option */
462 #define TE_FORCE_ECT1           0x40000000  /* Force setting ECT1 on outgoing packets for testing purpose */
463 #define TE_FORCE_ECT0           0x80000000  /* Force setting ECT0 on outgoing packets for testing purpose */
464 
465 	u_int32_t       t_ecn_recv_ce;  /* Received CE from the network */
466 	u_int32_t       t_ecn_recv_cwr; /* Packets received with CWR */
467 	uint32_t        t_client_accecn_state;    /* Client's Accurate ECN state */
468 	uint32_t        t_server_accecn_state;    /* Server's Accurate ECN state */
469 	uint64_t        t_ecn_capable_packets_sent;     /* Packets sent with ECT */
470 	uint64_t        t_ecn_capable_packets_acked;    /* Packets sent with ECT that were acked */
471 	uint64_t        t_ecn_capable_packets_marked;   /* Packets sent with ECT that were marked */
472 	uint64_t        t_ecn_capable_packets_lost;     /* Packets sent with ECT that were lost */
473 
474 	uint16_t        t_prev_ace_flags;   /* ACE flags that were sent in previous packet, used for retransmitting after timeout */
475 	uint8_t         t_prev_ip_ecn;      /* IP ECN flag on the previous packet, used for change-triggered ACKs */
476 
477 /* ACE CE packet counters */
478 	uint32_t        t_rcv_ce_packets;   /* Number of CE received packets at the receiver */
479 	uint32_t        t_snd_ce_packets;   /* Synced number of CE received feedback at the sender */
480 	uint32_t        t_delta_ce_packets; /* Change in CE count between previous and current ACK */
481 
482 /* AccECN option byte counters, sender side counters (s_) must not be used until they are synced from TCP options */
483 	uint64_t        t_rcv_ect1_bytes;   /* ECT1 byte counter at the receiver, used for AccECN option feedback */
484 	uint64_t        t_rcv_ect0_bytes;   /* ECT0 byte counter at the receiver, used for AccECN option feedback */
485 	uint64_t        t_rcv_ce_bytes;     /* CE byte counter at the receiver, used for AccECN option feedback */
486 	uint64_t        t_snd_ect1_bytes;   /* Synced ECT1 byte counter at the sender */
487 	uint64_t        t_snd_ect0_bytes;   /* Synced ECT0 byte counter at the sender */
488 	uint64_t        t_snd_ce_bytes;     /* Synced CE byte counter at the sender */
489 
490 /* state for bad retransmit recovery */
491 	u_int32_t       snd_cwnd_prev;  /* cwnd prior to retransmit */
492 	u_int32_t       snd_ssthresh_prev; /* ssthresh prior to retransmit */
493 	tcp_seq snd_recover_prev;       /* snd_recover prior to retransmit */
494 	int     t_srtt_prev;            /* srtt prior to retransmit */
495 	int     t_rttvar_prev;          /* rttvar prior to retransmit */
496 	u_int32_t       t_badrexmt_time; /* bad rexmt detection time */
497 
498 /* Packet reordering metric */
499 	u_int32_t       t_reorderwin; /* Reordering late time offset */
500 
501 /* SACK related state */
502 	int16_t snd_numholes;           /* number of holes seen by sender */
503 	tcp_seq sack_newdata;           /* New data xmitted in this recovery
504 	                                 *   episode starts at this seq number */
505 	TAILQ_HEAD(sackhole_head, sackhole) snd_holes;
506 	/* SACK scoreboard (sorted) */
507 	tcp_seq snd_fack;               /* last seq number(+1) sack'd by rcv'r*/
508 	int     rcv_numsacks;           /* # distinct sack blks present */
509 	struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
510 	struct sackhint sackhint;       /* SACK scoreboard hint */
511 	tcp_seq         send_highest_sack; /* Sequence number of fresh data sent after the most recent fast-retransmit */
512 	int             t_new_dupacks; /* Dupacks received above send_highest_sack */
513 
514 	struct mbuf     *t_pktlist_head; /* First packet in transmit chain */
515 	struct mbuf     *t_pktlist_tail; /* Last packet in transmit chain */
516 	u_int32_t       t_pktlist_sentlen; /* total bytes in transmit chain */
517 
518 	u_int32_t       t_keepidle;     /* keepalive idle timer (override global if > 0) */
519 	u_int32_t       t_keepinit;     /* connection timeout, i.e. idle time
520 	                                 *  in SYN_SENT or SYN_RECV state */
521 	u_int32_t       t_keepintvl;    /* interval between keepalives */
522 	u_int32_t       t_keepcnt;      /* number of keepalives before close */
523 
524 	u_int32_t       tso_max_segment_size;   /* TSO maximum segment unit for NIC */
525 	u_int16_t       t_pmtud_lastseg_size;   /* size of the last sent segment */
526 	u_int32_t       t_pmtud_saved_maxopd;   /* MSS saved before performing PMTU-D BlackHole detection */
527 	u_int32_t       t_pmtud_start_ts;       /* Time of PMTUD blackhole detection */
528 
529 	struct{
530 		u_int32_t       rxduplicatebytes;
531 		u_int32_t       rxoutoforderbytes;
532 		u_int32_t       txretransmitbytes;
533 		u_int16_t       synrxtshift;
534 		u_int16_t       rxmitsyns;
535 		u_int16_t       unused_pad_to_8;
536 		u_int32_t       rxmitpkts;
537 		uint32_t        delayed_acks_sent;
538 		uint32_t        acks_delayed;
539 	} t_stat;
540 	u_int8_t        t_syn_sent;
541 	u_int8_t        t_syn_rcvd;
542 	u_int8_t        t_notify_ack_count;
543 	u_int8_t        t_ecn_recv_ce_pkt; /* Received packet with CE-bit set (independent from last_ack_sent) */
544 	u_int32_t       t_cached_maxopd; /* default for MSS adjustment using link status report */
545 
546 	uint32_t        bg_ssthresh;            /* Slow start threshold until delay increases */
547 	uint32_t        t_flagsext;             /* Another field to accommodate more flags */
548 #define TF_RXTFINDROP           0x1                     /* Drop conn after retransmitting FIN 3 times */
549 #define TF_RCVUNACK_WAITSS      0x2             /* set when the receiver should not stretch acks */
550 #define TF_BWMEAS_INPROGRESS    0x4             /* Indicate BW meas is happening */
551 #define TF_MEASURESNDBW         0x8             /* Measure send bw on this connection */
552 #define TF_LAST_IS_PSH          0x10            /* Indicates whether the last packet in the rcv socket buffer had the PUSH-flag set */
553 #define TF_SACK_ENABLE          0x20            /* SACK is enabled */
554 #define TF_RECOMPUTE_RTT        0x40            /* recompute RTT after spurious retransmit */
555 #define TF_DETECT_READSTALL     0x80            /* Used to detect a stall during read operation */
556 #define TF_RECV_THROTTLE        0x100           /* Input throttling active */
557 #define TF_NOSTRETCHACK         0x200           /* ack every other packet */
558 #define TF_NOTIMEWAIT           0x800           /* Avoid going into time-wait */
559 #define TF_SENT_TLPROBE         0x1000          /* Sent data in PTO */
560 #define TF_PKTS_REORDERED       0x2000          /* Detected reordering */
561 #define TF_DELAY_RECOVERY       0x4000          /* delay fast recovery */
562 #define TF_FORCE                0x8000          /* force 1 byte out */
563 #define TF_DISABLE_STRETCHACK   0x10000         /* auto-disable stretch ack */
564 #define TF_NOBLACKHOLE_DETECTION 0x20000        /* Disable PMTU blackhole detection */
565 #define TF_RESCUE_RXT           0x80000         /* SACK rescue retransmit */
566 #define TF_CWND_NONVALIDATED    0x100000        /* cwnd non validated */
567 #define TF_IF_PROBING           0x200000        /* Trigger interface probe timeout */
568 #define TF_FASTOPEN             0x400000        /* TCP Fastopen is enabled */
569 #define TF_REASS_INPROG         0x800000        /* Reassembly is in progress */
570 #define TF_FASTOPEN_FORCE_ENABLE 0x1000000      /* Force-enable TCP Fastopen */
571 #define TF_USR_OUTPUT           0x2000000       /* In connect() or send() so tcp_output() can log */
572 #define TF_L4S_ENABLED          0x8000000       /* L4S was force enabled */
573 #define TF_L4S_DISABLED         0x10000000      /* L4S was force disabled */
574 
575 #if TRAFFIC_MGT
576 	/* Inter-arrival jitter related state */
577 	uint32_t        iaj_rcv_ts;             /* tcp clock when the first packet was received */
578 	int             iaj_size;               /* Size of packet for iaj measurement */
579 	uint8_t         iaj_small_pkt;          /* Count of packets smaller than iaj_size */
580 	uint8_t         t_pipeack_ind;          /* index for next pipeack sample */
581 	uint16_t        iaj_pktcnt;             /* packet count, to avoid throttling initially */
582 	uint32_t        acc_iaj;                /* Accumulated iaj */
583 	uint32_t        avg_iaj;                /* Mean */
584 	uint32_t        std_dev_iaj;            /* Standard deviation */
585 #endif /* TRAFFIC_MGT */
586 	struct bwmeas   *t_bwmeas;              /* State for bandwidth measurement */
587 	tcp_seq         t_idleat;               /* rcv_nxt at idle time */
588 	uint8_t         t_fin_sent;
589 	uint8_t         t_fin_rcvd;
590 	uint8_t         t_rst_sent;
591 	uint8_t         t_rst_rcvd;
592 	TAILQ_ENTRY(tcpcb) t_twentry;           /* link for time wait queue */
593 	struct tcp_ccstate      *t_ccstate;     /* congestion control related state */
594 	struct tcp_ccstate      _t_ccstate;     /* congestion control related state, non-allocated */
595 /* Tail loss probe related state */
596 	tcp_seq         t_tlphighrxt;           /* snd_nxt after PTO */
597 	u_int32_t       t_tlpstart;             /* timestamp at PTO */
598 /* DSACK data receiver state */
599 	tcp_seq         t_dsack_lseq;           /* DSACK left sequence */
600 	tcp_seq         t_dsack_rseq;           /* DSACK right sequence */
601 /* DSACK data sender state */
602 	SLIST_HEAD(tcp_rxt_seghead, tcp_rxt_seg) t_rxt_segments;
603 	uint32_t        t_rxt_seg_count;
604 	uint32_t        t_rxt_seg_drop;
605 	tcp_seq         t_dsack_lastuna;        /* snd_una when last recovery episode started */
606 /* state for congestion window validation (draft-ietf-tcpm-newcwv-07) */
607 #define TCP_PIPEACK_SAMPLE_COUNT        3
608 	u_int32_t       t_pipeack_sample[TCP_PIPEACK_SAMPLE_COUNT];     /* pipeack, bytes acked within RTT */
609 	tcp_seq         t_pipeack_lastuna; /* una when pipeack measurement started */
610 	u_int32_t       t_pipeack;
611 	u_int32_t       t_lossflightsize;
612 
613 #if MPTCP
614 	u_int32_t       t_mpflags;              /* flags for multipath TCP */
615 
616 #define TMPF_PREESTABLISHED     0x00000001 /* conn in pre-established state */
617 #define TMPF_SND_KEYS           0x00000002 /* indicates that keys should be send */
618 #define TMPF_MPTCP_TRUE         0x00000004 /* negotiated MPTCP successfully */
619 /* UNUSED */
620 #define TMPF_SND_MPPRIO         0x00000010 /* send priority of subflow */
621 #define TMPF_SND_REM_ADDR       0x00000020 /* initiate address removal */
622 #define TMPF_RCVD_DACK          0x00000040 /* received a data-ack */
623 #define TMPF_JOINED_FLOW        0x00000080 /* Indicates additional flow */
624 #define TMPF_BACKUP_PATH        0x00000100 /* Indicates backup path */
625 #define TMPF_MPTCP_ACKNOW       0x00000200 /* Send Data ACK */
626 #define TMPF_SEND_DSN           0x00000400 /* Send DSN mapping */
627 #define TMPF_SEND_DFIN          0x00000800 /* Send Data FIN */
628 #define TMPF_RECV_DFIN          0x00001000 /* Recv Data FIN */
629 #define TMPF_SENT_JOIN          0x00002000 /* Sent Join */
630 #define TMPF_RECVD_JOIN         0x00004000 /* Received Join */
631 #define TMPF_RESET              0x00008000 /* Send RST */
632 #define TMPF_TCP_FALLBACK       0x00010000 /* Fallback to TCP */
633 #define TMPF_FASTCLOSERCV       0x00020000 /* Received Fastclose option */
634 #define TMPF_EMBED_DSN          0x00040000 /* tp has DSN mapping */
635 #define TMPF_MPTCP_READY        0x00080000 /* Can send DSS options on data */
636 #define TMPF_INFIN_SENT         0x00100000 /* Sent infinite mapping */
637 #define TMPF_SND_MPFAIL         0x00200000 /* Received mapping csum failure */
638 #define TMPF_SND_JACK           0x00400000 /* Send a Join-ACK */
639 #define TMPF_TFO_REQUEST        0x00800000 /* TFO Requested */
640 #define TMPF_MPTCP_ECHO_ADDR    0x01000000 /* MPTCP echoes add_addr */
641 
642 #define TMPF_MPTCP_SIGNALS      (TMPF_SND_MPPRIO | TMPF_SND_REM_ADDR | TMPF_SND_MPFAIL | TMPF_SND_JACK)
643 
644 	tcp_seq                 t_mpuna;        /* unacknowledged sequence */
645 	struct mptcb            *t_mptcb;       /* pointer to MPTCP TCB */
646 	struct mptsub           *t_mpsub;       /* pointer to the MPTCP subflow */
647 	struct mpt_dsn_map      t_rcv_map;      /* Receive mapping list */
648 	u_int8_t                t_local_aid;    /* Addr Id for authentication */
649 	u_int8_t                t_rem_aid;      /* Addr ID of another subflow */
650 	u_int8_t                t_mprxtshift;   /* join retransmission */
651 #endif /* MPTCP */
652 
653 #define TFO_F_OFFER_COOKIE      0x01 /* We will offer a cookie */
654 #define TFO_F_COOKIE_VALID      0x02 /* The received cookie is valid */
655 #define TFO_F_COOKIE_REQ        0x04 /* Client requested a new cookie */
656 #define TFO_F_COOKIE_SENT       0x08 /* Client did send a cookie in the SYN */
657 #define TFO_F_SYN_LOSS          0x10 /* A SYN-loss triggered a fallback to regular TCP on the client-side */
658 #define TFO_F_NO_SNDPROBING     0x20 /* This network is guaranteed to support TFO in the upstream direction */
659 #define TFO_F_HEURISTIC_DONE    0x40 /* We have already marked this network as bad */
660 	u_int8_t                t_tfo_flags;
661 #define TFO_S_SYNDATA_RCV       0x01 /* SYN+data has been received */
662 #define TFO_S_COOKIEREQ_RECV    0x02 /* TFO-cookie request received */
663 #define TFO_S_COOKIE_SENT       0x04 /* TFO-cookie announced in SYN/ACK */
664 #define TFO_S_COOKIE_INVALID    0x08 /* Received TFO-cookie is invalid */
665 #define TFO_S_COOKIE_REQ        0x10 /* TFO-cookie requested within the SYN */
666 #define TFO_S_COOKIE_RCV        0x20 /* TFO-cookie received in SYN/ACK */
667 #define TFO_S_SYN_DATA_SENT     0x40 /* SYN+data sent */
668 #define TFO_S_SYN_DATA_ACKED    0x80 /* SYN+data has been acknowledged in SYN/ACK */
669 #define TFO_S_SYN_LOSS          0x0100 /* SYN+TFO has been lost - fallback to regular TCP */
670 #define TFO_S_COOKIE_WRONG      0x0200 /* Cookie we sent in the SYN was wrong */
671 #define TFO_S_NO_COOKIE_RCV     0x0400 /* We asked for a cookie but didn't get one */
672 #define TFO_S_HEURISTICS_DISABLE 0x0800 /* TFO-heuristics disabled it for this connection */
673 #define TFO_S_SEND_BLACKHOLE    0x1000 /* TFO got blackholed in the send direction */
674 #define TFO_S_RECV_BLACKHOLE    0x2000 /* TFO got blackholed in the recv direction */
675 #define TFO_S_ONE_BYTE_PROXY    0x4000 /* TFO failed because of a proxy acknowledging just one byte */
676 	u_int16_t               t_tfo_stats;
677 
678 	u_int8_t                t_tfo_probes; /* TFO-probes we did send */
679 /*
680  * This here is the TFO-probing state-machine. Transitions are as follows:
681  *
682  * Current state: PROBE_NONE
683  *		  Event: SYN+DATA acknowledged
684  *			 Action: Transition to PROBE_PROBING and set keepalive-timer
685  *
686  * Current state: PROBE_PROBING (initial state)
687  *		  Event: Receive data
688  *			 Action: Transition to PROBE_NONE and cancel keepalive-timer
689  *		  Event: Receive ACK that does not indicate a hole
690  *			 Action: Transition to PROBE_NONE and cancel keepalive-timer
691  *		  Event: Receive ACK that indicates a hole
692  *			 Action: Transition to PROBE_WAIT_DATA and set a short timer
693  *				 to wait for the final segment.
694  *		  Event: Keepalive-timeout (did not receive any segment)
695  *			 Action: Signal ETIMEDOUT as with regular keepalive-timers
696  *
697  * Current state: PROBE_WAIT_DATA
698  *		  Event: Receive data
699  *			 Action: Transition to PROBE_NONE and cancel keepalive-timer
700  *		  Event: Data-timeout (did not receive the expected data)
701  *			 Action: Signal ENODATA up to the app and close everything.
702  */
703 #define TFO_PROBE_NONE          0 /* Not probing now */
704 #define TFO_PROBE_PROBING       1 /* Sending out TCP-keepalives waiting for reply */
705 #define TFO_PROBE_WAIT_DATA     2 /* Received reply, waiting for data */
706 	u_int8_t                t_tfo_probe_state;
707 
708 	u_int32_t       t_rcvoopack;            /* out-of-order packets received */
709 	u_int32_t       t_pawsdrop;             /* segments dropped due to PAWS */
710 	u_int32_t       t_sack_recovery_episode; /* SACK recovery episodes */
711 	u_int32_t       t_reordered_pkts;       /* packets reorderd */
712 	u_int32_t       t_dsack_sent;           /* Sent DSACK notification */
713 	u_int32_t       t_dsack_recvd;          /* Received a valid DSACK option */
714 	SLIST_HEAD(, tcp_notify_ack_marker) t_notify_ack; /* state for notifying data acknowledgements */
715 	u_int32_t       t_recv_throttle_ts;     /* TS for start of recv throttle */
716 	u_int32_t       t_rxt_minimum_timeout;  /* minimum retransmit timeout in ms */
717 	uint32_t        t_challengeack_last;    /* last time challenge ACK was sent per sec */
718 	uint32_t        t_challengeack_count;   /* # of challenge ACKs already sent per sec */
719 
720 	u_int32_t       t_connect_time;         /* time when the connection started */
721 
722 	uint32_t        t_comp_gencnt; /* Current compression generation-count */
723 	uint32_t        t_comp_lastinc; /* Last time the gen-count was changed - should change every TCP_COMP_CHANGE_RATE ms */
724 #define TCP_COMP_CHANGE_RATE    5 /* Intervals at which we change the gencnt. Means that worst-case we send one ACK every TCP_COMP_CHANGE_RATE ms */
725 
726 	uint32_t        t_ts_offset; /* Randomized timestamp offset to hide on-the-wire timestamp */
727 
728 #define NCURR_RTT_HIST 4                         /* Number of current RTT samples (k) */
729 	uint32_t curr_rtt_hist[NCURR_RTT_HIST];  /* last k current RTT samples */
730 	uint32_t curr_rtt_min;                   /* Minimum current RTT from last k samples */
731 	uint32_t curr_rtt_index;                 /* Index for current RTT samples */
732 
733 	tcp_seq rcv_high;                   /* highest sequence number received */
734 	uint32_t tsv_high;                  /* timestamp value of highest received sequence number */
735 	struct tcp_rledbat_state t_rlstate; /* State used by rLedbat */
736 
737 	uint32_t rcv_srtt;                  /* receiver's SRTT, coarse when Timestamp not supported */
738 	uint32_t rcv_rtt_est_ts;            /* start of measurement for estimating RTT when Timestamp not supported */
739 	uint32_t rcv_rtt_est_seq;           /* expected sequence number for completion of 1RTT when Timestamp not supported */
740 
741 	uuid_t          t_fsw_uuid;
742 	uuid_t          t_flow_uuid;
743 };
744 
745 #define IN_FASTRECOVERY(tp)     (tp->t_flags & TF_FASTRECOVERY)
746 #define SACK_ENABLED(tp)        (tp->t_flagsext & TF_SACK_ENABLE)
747 
748 /*
749  * If the connection is in a throttled state due to advisory feedback from
750  * the interface output queue, reset that state. We do this in favor
751  * of entering recovery because the data transfer during recovery
752  * should be just a trickle and it will help to improve performance.
753  * We also do not want to back off twice in the same RTT.
754  */
755 #define ENTER_FASTRECOVERY(_tp_) do {                                           \
756 	(_tp_)->t_flags |= TF_FASTRECOVERY;                                     \
757 	if (INP_IS_FLOW_CONTROLLED((_tp_)->t_inpcb))                            \
758 	        inp_reset_fc_state((_tp_)->t_inpcb);                            \
759 	if (!SLIST_EMPTY(&tp->t_rxt_segments))                                  \
760 	        tcp_rxtseg_clean(tp);                                           \
761 	(_tp_)->t_new_dupacks = 0;                                              \
762 } while(0)
763 
764 #define EXIT_FASTRECOVERY(_tp_) do {                                            \
765 	(_tp_)->t_flags &= ~TF_FASTRECOVERY;                                    \
766 	(_tp_)->t_dupacks = 0;                                                  \
767 	(_tp_)->t_new_dupacks = 0;                                              \
768 	(_tp_)->t_rexmtthresh = (uint8_t)tcprexmtthresh;                        \
769 	(_tp_)->t_bytes_acked = 0;                                              \
770 	(_tp_)->ecn_flags &= ~TE_INRECOVERY;                                    \
771 	(_tp_)->t_timer[TCPT_PTO] = 0;                                          \
772 	(_tp_)->t_flagsext &= ~TF_RESCUE_RXT;                                   \
773 	(_tp_)->t_lossflightsize = 0;                                           \
774 	(_tp_)->sackhint.sack_bytes_acked = 0;                                  \
775 } while(0)
776 
777 /*
778  * When the number of duplicate acks received is less than
779  * the retransmit threshold, use Limited Transmit algorithm
780  */
781 extern uint8_t tcprexmtthresh;
782 #define ALLOW_LIMITED_TRANSMIT(_tp_)                                            \
783 	((_tp_)->t_dupacks > 0 &&                                               \
784 	(_tp_)->t_dupacks < (_tp_)->t_rexmtthresh &&                            \
785 	((_tp_)->t_flagsext & (TF_PKTS_REORDERED|TF_DELAY_RECOVERY))            \
786 	    != (TF_PKTS_REORDERED|TF_DELAY_RECOVERY))
787 
788 /*
789  * This condition is true if timestamp option is supported
790  * on a connection.
791  */
792 #define TSTMP_SUPPORTED(_tp_) \
793 	(((_tp_)->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP)) == \
794 	        (TF_REQ_TSTMP|TF_RCVD_TSTMP))
795 
796 /*
797  * This condition is true if window scale option is supported
798  * on a connection
799  */
800 #define TCP_WINDOW_SCALE_ENABLED(_tp_) \
801 	(((_tp_)->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) == \
802 	        (TF_RCVD_SCALE|TF_REQ_SCALE))
803 
804 /* Is ECN negotiated end-to-end */
805 #define TCP_ECN_ENABLED(_tp_) \
806 	(((_tp_)->ecn_flags & (TE_ECN_ON)) == (TE_ECN_ON))
807 
808 extern int tcp_acc_ecn;
809 /*
810  * Accurate ECN feedback is enabled if
811  * 1. It is not disabled explicitly by tcp options
812  * 2. It is enabled either by sysctl or L4S toggle or A/B deployment or tcp_options,
813  * It supports ACE field as well as AccECN option for ECN feedback
814  */
815 #define TCP_ACC_ECN_ENABLED(_tp_) \
816    (((_tp_)->t_flagsext & TF_L4S_DISABLED) == 0 && \
817    (tcp_acc_ecn == 1 || ((_tp_)->t_flagsext & TF_L4S_ENABLED)))
818 
819 /* Accurate ECN is enabled and negotiated end-to-end */
820 #define TCP_ACC_ECN_ON(_tp_) \
821     (TCP_ACC_ECN_ENABLED(_tp_) && \
822     (((_tp_)->ecn_flags & (TE_ACC_ECN_ON)) == (TE_ACC_ECN_ON)))
823 
824 /*
825  * Gives number of bytes acked by this ack
826  */
827 #define BYTES_ACKED(_th_, _tp_) \
828 	((_th_)->th_ack - (_tp_)->snd_una)
829 
830 /* Returns true if a DSACK option should be sent */
831 #define TCP_SEND_DSACK_OPT(_tp_) \
832 	((_tp_)->t_dsack_lseq > 0 && (_tp_)->t_dsack_rseq > 0)
833 
834 /*
835  * Returns true if a DSACK sequence is within the max send window that will
836  * be accepted. In order to set a window to validate sequence numbers, the
837  * max send window within which a DSACK option is processed is limited.
838  *
839  * We need to choose a maximum window to check if the sequence number is
840  * within the window. One arbitrary choice is 256 * MSS because if the
841  * window is as large as 256 segments it might be big enough to ignore the
842  * DSACK option. Choosing a much larger limit means that the memory for
843  * retransmit segments can be held for a longer time.
844  */
845 #define TCP_DSACK_MAX_SEND_WINDOW(_tp_) (MIN((_tp_)->snd_wnd, tcp_autosndbuf_max))
846 #define TCP_DSACK_SEQ_IN_WINDOW(_tp_, _seq_, _una_) \
847     (SEQ_LEQ((_seq_), (_tp_)->snd_max) && \
848     SEQ_GEQ((_seq_), ((_una_) - TCP_DSACK_MAX_SEND_WINDOW(_tp_))))
849 
850 #define TCP_RESET_REXMT_STATE(_tp_) do { \
851 	(_tp_)->t_rxtshift = 0; \
852 	(_tp_)->t_rxtstart = 0; \
853 	mptcp_reset_rexmit_state((_tp_)); \
854 } while(0);
855 
856 #define TCP_IF_STATE_CHANGED(tp, probe_if_index)                        \
857 	(probe_if_index > 0 && tp->t_inpcb->inp_last_outifp != NULL &&  \
858 	probe_if_index == tp->t_inpcb->inp_last_outifp->if_index)
859 
860 #define TCP_RLEDBAT_ENABLED(_tp) \
861     (tcp_rledbat == 1 && TSTMP_SUPPORTED(_tp))
862 
863 #define TCP_RECV_BG(_so) \
864     (tcp_recv_bg == 1 || IS_TCP_RECV_BG(_so))
865 
866 #define TCP_USE_RLEDBAT(_tp, _so) \
867     TCP_RLEDBAT_ENABLED(_tp) && TCP_RECV_BG(_so)
868 
869 /*
870  * Structure to hold TCP options that are only used during segment
871  * processing (in tcp_input), but not held in the tcpcb.
872  * It's basically used to reduce the number of parameters
873  * to tcp_dooptions.
874  */
875 struct tcpopt {
876 	uint32_t        to_flags;               /* which options are present */
877 #define TOF_TS          0x0001          /* timestamp */
878 #define TOF_MSS         0x0010
879 #define TOF_SCALE       0x0020
880 #define TOF_SIGNATURE   0x0040  /* signature option present */
881 #define TOF_SIGLEN      0x0080  /* signature length valid (RFC2385) */
882 #define TOF_SACK        0x0100          /* Peer sent SACK option */
883 #define TOF_MPTCP       0x0200  /* MPTCP options to be dropped */
884 #define TOF_TFO         0x0400  /* TFO cookie option present */
885 #define TOF_TFOREQ      0x0800  /* TFO cookie request present */
886 	uint32_t        to_tsval;
887 	uint32_t        to_tsecr;
888 	uint16_t        to_mss;
889 	uint8_t         to_requested_s_scale;
890 	uint8_t         to_nsacks;      /* number of SACK blocks */
891 	u_char          *to_sacks;      /* pointer to the first SACK blocks */
892 	u_char          *to_tfo;        /* pointer to the TFO cookie */
893 };
894 
895 #define intotcpcb(ip)   ((struct tcpcb *)(ip)->inp_ppcb)
896 #define sototcpcb(so)   (intotcpcb(sotoinpcb(so)))
897 
898 /* TFO-specific defines */
899 #define TFO_COOKIE_LEN_MIN      4
900 #define TFO_COOKIE_LEN_DEFAULT  8
901 #define TFO_COOKIE_LEN_MAX      16
902 
903 /*
904  * The initial retransmission should happen at rtt + 4 * rttvar.
905  * Because of the way we do the smoothing, srtt and rttvar
906  * will each average +1/2 tick of bias.  When we compute
907  * the retransmit timer, we want 1/2 tick of rounding and
908  * 1 extra tick because of +-1/2 tick uncertainty in the
909  * firing of the timer.  The bias will give us exactly the
910  * 1.5 tick we need.  But, because the bias is
911  * statistical, we have to test that we don't drop below
912  * the minimum feasible timer (which is 2 ticks).
913  * This version of the macro adapted from a paper by Lawrence
914  * Brakmo and Larry Peterson which outlines a problem caused
915  * by insufficient precision in the original implementation,
916  * which results in inappropriately large RTO values for very
917  * fast networks.
918  */
919 #define TCP_REXMTVAL(tp) \
920 	max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
921 	  + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
922 
923 /*
924  * Jaguar compatible TCP control block, for xtcpcb
925  * Does not have the old fields
926  */
927 struct otcpcb {
928 #else
929 struct tseg_qent;
930 _TCPCB_LIST_HEAD(tsegqe_head, tseg_qent);
931 
932 struct tcpcb {
933 #endif /* KERNEL_PRIVATE */
934 #if defined(KERNEL_PRIVATE)
935 	u_int32_t t_segq;
936 #else
937 	struct  tsegqe_head t_segq;
938 #endif /* KERNEL_PRIVATE */
939 	int     t_dupacks;              /* consecutive dup acks recd */
940 	u_int32_t unused;               /* unused now: was t_template */
941 
942 	int     t_timer[TCPT_NTIMERS_EXT];      /* tcp timers */
943 
944 	_TCPCB_PTR(struct inpcb *) t_inpcb;     /* back pointer to internet pcb */
945 	int     t_state;                /* state of this connection */
946 	u_int   t_flags;
947 #define TF_ACKNOW       0x00001         /* ack peer immediately */
948 #define TF_DELACK       0x00002         /* ack, but try to delay it */
949 #define TF_NODELAY      0x00004         /* don't delay packets to coalesce */
950 #define TF_NOOPT        0x00008         /* don't use tcp options */
951 #define TF_SENTFIN      0x00010         /* have sent FIN */
952 #define TF_REQ_SCALE    0x00020         /* have/will request window scaling */
953 #define TF_RCVD_SCALE   0x00040         /* other side has requested scaling */
954 #define TF_REQ_TSTMP    0x00080         /* have/will request timestamps */
955 #define TF_RCVD_TSTMP   0x00100         /* a timestamp was received in SYN */
956 #define TF_SACK_PERMIT  0x00200         /* other side said I could SACK */
957 #define TF_NEEDSYN      0x00400         /* send SYN (implicit state) - unused but needed for backwards compatibility */
958 #define TF_NEEDFIN      0x00800         /* send FIN (implicit state) */
959 #define TF_NOPUSH       0x01000         /* don't push */
960 #define TF_REQ_CC       0x02000         /* have/will request CC */
961 #define TF_RCVD_CC      0x04000         /* a CC was received in SYN */
962 #define TF_SENDCCNEW    0x08000         /* Not implemented */
963 #define TF_MORETOCOME   0x10000         /* More data to be appended to sock */
964 #define TF_LQ_OVERFLOW  0x20000         /* listen queue overflow */
965 #define TF_RXWIN0SENT   0x40000         /* sent a receiver win 0 in response */
966 #define TF_SLOWLINK     0x80000         /* route is a on a modem speed link */
967 
968 	int     t_force;                /* 1 if forcing out a byte */
969 
970 	tcp_seq snd_una;                /* send unacknowledged */
971 	tcp_seq snd_max;                /* highest sequence number sent;
972 	                                 * used to recognize retransmits
973 	                                 */
974 	tcp_seq snd_nxt;                /* send next */
975 	tcp_seq snd_up;                 /* send urgent pointer */
976 
977 	tcp_seq snd_wl1;                /* window update seg seq number */
978 	tcp_seq snd_wl2;                /* window update seg ack number */
979 	tcp_seq iss;                    /* initial send sequence number */
980 	tcp_seq irs;                    /* initial receive sequence number */
981 
982 	tcp_seq rcv_nxt;                /* receive next */
983 	tcp_seq rcv_adv;                /* advertised window */
984 	u_int32_t rcv_wnd;              /* receive window */
985 	tcp_seq rcv_up;                 /* receive urgent pointer */
986 
987 	u_int32_t snd_wnd;              /* send window */
988 	u_int32_t snd_cwnd;             /* congestion-controlled window */
989 	u_int32_t snd_ssthresh;         /* snd_cwnd size threshold for
990 	                                 * for slow start exponential to
991 	                                 * linear switch
992 	                                 */
993 	u_int   t_maxopd;               /* mss plus options */
994 
995 	u_int32_t t_rcvtime;            /* time at which a packet was received */
996 	u_int32_t t_starttime;          /* time connection was established */
997 	int     t_rtttime;              /* round trip time */
998 	tcp_seq t_rtseq;                /* sequence number being timed */
999 
1000 	int     t_rxtcur;               /* current retransmit value (ticks) */
1001 	u_int   t_maxseg;               /* maximum segment size */
1002 	int     t_srtt;                 /* smoothed round-trip time */
1003 	int     t_rttvar;               /* variance in round-trip time */
1004 
1005 	int     t_rxtshift;             /* log(2) of rexmt exp. backoff */
1006 	u_int   t_rttmin;               /* minimum rtt allowed */
1007 	u_int32_t t_rttupdated;         /* number of times rtt sampled */
1008 	u_int32_t max_sndwnd;           /* largest window peer has offered */
1009 
1010 	int     t_softerror;            /* possible error not yet reported */
1011 /* out-of-band data */
1012 	char    t_oobflags;             /* have some */
1013 	char    t_iobc;                 /* input character */
1014 #define TCPOOB_HAVEDATA 0x01
1015 #define TCPOOB_HADDATA  0x02
1016 /* RFC 1323 variables */
1017 	u_char  snd_scale;              /* window scaling for send window */
1018 	u_char  rcv_scale;              /* window scaling for recv window */
1019 	u_char  request_r_scale;        /* pending window scaling */
1020 	u_char  requested_s_scale;
1021 	u_int32_t ts_recent;            /* timestamp echo data */
1022 
1023 	u_int32_t ts_recent_age;        /* when last updated */
1024 	tcp_seq last_ack_sent;
1025 /* RFC 1644 variables */
1026 	tcp_cc  cc_send;                /* send connection count */
1027 	tcp_cc  cc_recv;                /* receive connection count */
1028 	tcp_seq snd_recover;            /* for use in fast recovery */
1029 /* experimental */
1030 	u_int32_t snd_cwnd_prev;        /* cwnd prior to retransmit */
1031 	u_int32_t snd_ssthresh_prev;    /* ssthresh prior to retransmit */
1032 	u_int32_t t_badrxtwin;          /* window for retransmit recovery */
1033 };
1034 
1035 #define        tcps_ecn_setup  tcps_ecn_client_success
1036 #define        tcps_sent_cwr   tcps_ecn_recv_ece
1037 #define        tcps_sent_ece   tcps_ecn_sent_ece
1038 
1039 /*
1040  * TCP statistics.
1041  * Many of these should be kept per connection,
1042  * but that's inconvenient at the moment.
1043  */
1044 struct  tcpstat {
1045 	u_int32_t       tcps_connattempt;       /* connections initiated */
1046 	u_int32_t       tcps_accepts;           /* connections accepted */
1047 	u_int32_t       tcps_connects;          /* connections established */
1048 	u_int32_t       tcps_drops;             /* connections dropped */
1049 	u_int32_t       tcps_conndrops;         /* embryonic connections dropped */
1050 	u_int32_t       tcps_closed;            /* conn. closed (includes drops) */
1051 	u_int32_t       tcps_segstimed;         /* segs where we tried to get rtt */
1052 	u_int32_t       tcps_rttupdated;        /* times we succeeded */
1053 	u_int32_t       tcps_delack;            /* delayed acks sent */
1054 	u_int32_t       tcps_timeoutdrop;       /* conn. dropped in rxmt timeout */
1055 	u_int32_t       tcps_rexmttimeo;        /* retransmit timeouts */
1056 	u_int32_t       tcps_persisttimeo;      /* persist timeouts */
1057 	u_int32_t       tcps_keeptimeo;         /* keepalive timeouts */
1058 	u_int32_t       tcps_keepprobe;         /* keepalive probes sent */
1059 	u_int32_t       tcps_keepdrops;         /* connections dropped in keepalive */
1060 
1061 	u_int32_t       tcps_sndtotal;          /* total packets sent */
1062 	u_int32_t       tcps_sndpack;           /* data packets sent */
1063 	u_int32_t       tcps_sndbyte;           /* data bytes sent */
1064 	u_int32_t       tcps_sndrexmitpack;     /* data packets retransmitted */
1065 	u_int32_t       tcps_sndrexmitbyte;     /* data bytes retransmitted */
1066 	u_int32_t       tcps_sndacks;           /* ack-only packets sent */
1067 	u_int32_t       tcps_sndprobe;          /* window probes sent */
1068 	u_int32_t       tcps_sndurg;            /* packets sent with URG only */
1069 	u_int32_t       tcps_sndwinup;          /* window update-only packets sent */
1070 	u_int32_t       tcps_sndctrl;           /* control (SYN|FIN|RST) packets sent */
1071 
1072 	u_int32_t       tcps_rcvtotal;          /* total packets received */
1073 	u_int32_t       tcps_rcvpack;           /* packets received in sequence */
1074 	u_int32_t       tcps_rcvbyte;           /* bytes received in sequence */
1075 	u_int32_t       tcps_rcvbadsum;         /* packets received with ccksum errs */
1076 	u_int32_t       tcps_rcvbadoff;         /* packets received with bad offset */
1077 	u_int32_t       tcps_rcvmemdrop;        /* packets dropped for lack of memory */
1078 	u_int32_t       tcps_rcvshort;          /* packets received too short */
1079 	u_int32_t       tcps_rcvduppack;        /* duplicate-only packets received */
1080 	u_int32_t       tcps_rcvdupbyte;        /* duplicate-only bytes received */
1081 	u_int32_t       tcps_rcvpartduppack;    /* packets with some duplicate data */
1082 	u_int32_t       tcps_rcvpartdupbyte;    /* dup. bytes in part-dup. packets */
1083 	u_int32_t       tcps_rcvoopack;         /* out-of-order packets received */
1084 	u_int32_t       tcps_rcvoobyte;         /* out-of-order bytes received */
1085 	u_int32_t       tcps_rcvpackafterwin;   /* packets with data after window */
1086 	u_int32_t       tcps_rcvbyteafterwin;   /* bytes rcvd after window */
1087 	u_int32_t       tcps_rcvafterclose;     /* packets rcvd after "close" */
1088 	u_int32_t       tcps_rcvwinprobe;       /* rcvd window probe packets */
1089 	u_int32_t       tcps_rcvdupack;         /* rcvd duplicate acks */
1090 	u_int32_t       tcps_rcvacktoomuch;     /* rcvd acks for unsent data */
1091 	u_int32_t       tcps_rcvackpack;        /* rcvd ack packets */
1092 	u_int32_t       tcps_rcvackbyte;        /* bytes acked by rcvd acks */
1093 	u_int32_t       tcps_rcvwinupd;         /* rcvd window update packets */
1094 	u_int32_t       tcps_pawsdrop;          /* segments dropped due to PAWS */
1095 	u_int32_t       tcps_predack;           /* times hdr predict ok for acks */
1096 	u_int32_t       tcps_preddat;           /* times hdr predict ok for data pkts */
1097 	u_int32_t       tcps_pcbcachemiss;
1098 	u_int32_t       tcps_cachedrtt;         /* times cached RTT in route updated */
1099 	u_int32_t       tcps_cachedrttvar;      /* times cached rttvar updated */
1100 	u_int32_t       tcps_cachedssthresh;    /* times cached ssthresh updated */
1101 	u_int32_t       tcps_usedrtt;           /* times RTT initialized from route */
1102 	u_int32_t       tcps_usedrttvar;        /* times RTTVAR initialized from rt */
1103 	u_int32_t       tcps_usedssthresh;      /* times ssthresh initialized from rt*/
1104 	u_int32_t       tcps_persistdrop;       /* timeout in persist state */
1105 	u_int32_t       tcps_badsyn;            /* bogus SYN, e.g. premature ACK */
1106 	u_int32_t       tcps_mturesent;         /* resends due to MTU discovery */
1107 	u_int32_t       tcps_listendrop;        /* listen queue overflows */
1108 	u_int32_t       tcps_synchallenge;      /* challenge ACK due to bad SYN */
1109 	u_int32_t       tcps_rstchallenge;      /* challenge ACK due to bad RST */
1110 
1111 	/* new stats from FreeBSD 5.4 sync up */
1112 	u_int32_t       tcps_minmssdrops;       /* average minmss too low drops */
1113 
1114 	u_int32_t       tcps_sndrexmitbad;      /* unnecessary packet retransmissions */
1115 	u_int32_t       tcps_badrst;            /* ignored RSTs in the window */
1116 
1117 	u_int32_t       tcps_sc_added;          /* entry added to syncache */
1118 	u_int32_t       tcps_sc_retransmitted;  /* syncache entry was retransmitted */
1119 	u_int32_t       tcps_sc_dupsyn;         /* duplicate SYN packet */
1120 	u_int32_t       tcps_sc_dropped;        /* could not reply to packet */
1121 	u_int32_t       tcps_sc_completed;      /* successful extraction of entry */
1122 	u_int32_t       tcps_sc_bucketoverflow; /* syncache per-bucket limit hit */
1123 	u_int32_t       tcps_sc_cacheoverflow;  /* syncache cache limit hit */
1124 	u_int32_t       tcps_sc_reset;          /* RST removed entry from syncache */
1125 	u_int32_t       tcps_sc_stale;          /* timed out or listen socket gone */
1126 	u_int32_t       tcps_sc_aborted;        /* syncache entry aborted */
1127 	u_int32_t       tcps_sc_badack;         /* removed due to bad ACK */
1128 	u_int32_t       tcps_sc_unreach;        /* ICMP unreachable received */
1129 	u_int32_t       tcps_sc_zonefail;       /* zalloc() failed */
1130 	u_int32_t       tcps_sc_sendcookie;     /* SYN cookie sent */
1131 	u_int32_t       tcps_sc_recvcookie;     /* SYN cookie received */
1132 
1133 	u_int32_t       tcps_hc_added;          /* entry added to hostcache */
1134 	u_int32_t       tcps_hc_bucketoverflow; /* hostcache per bucket limit hit */
1135 
1136 	/* SACK related stats */
1137 	u_int32_t       tcps_sack_recovery_episode; /* SACK recovery episodes */
1138 	u_int32_t       tcps_sack_rexmits;          /* SACK rexmit segments   */
1139 	u_int32_t       tcps_sack_rexmit_bytes;     /* SACK rexmit bytes      */
1140 	u_int32_t       tcps_sack_rcv_blocks;       /* SACK blocks (options) received */
1141 	u_int32_t       tcps_sack_send_blocks;      /* SACK blocks (options) sent     */
1142 	u_int32_t       tcps_sack_sboverflow;       /* SACK sendblock overflow   */
1143 
1144 	u_int32_t       tcps_bg_rcvtotal;       /* total background packets received */
1145 	u_int32_t       tcps_rxtfindrop;        /* drop conn after retransmitting FIN */
1146 	u_int32_t       tcps_fcholdpacket;      /* packets withheld because of flow control */
1147 
1148 	u_int32_t       tcps_limited_txt;       /* Limited transmit used */
1149 	u_int32_t       tcps_early_rexmt;       /* Early retransmit used */
1150 	u_int32_t       tcps_sack_ackadv;       /* Cumulative ack advanced along with sack */
1151 
1152 	/* Checksum related stats */
1153 	u_int32_t       tcps_rcv_swcsum;        /* tcp swcksum (inbound), packets */
1154 	u_int32_t       tcps_rcv_swcsum_bytes;  /* tcp swcksum (inbound), bytes */
1155 	u_int32_t       tcps_rcv6_swcsum;       /* tcp6 swcksum (inbound), packets */
1156 	u_int32_t       tcps_rcv6_swcsum_bytes; /* tcp6 swcksum (inbound), bytes */
1157 	u_int32_t       tcps_snd_swcsum;        /* tcp swcksum (outbound), packets */
1158 	u_int32_t       tcps_snd_swcsum_bytes;  /* tcp swcksum (outbound), bytes */
1159 	u_int32_t       tcps_snd6_swcsum;       /* tcp6 swcksum (outbound), packets */
1160 	u_int32_t       tcps_snd6_swcsum_bytes; /* tcp6 swcksum (outbound), bytes */
1161 	u_int32_t       tcps_unused_1;
1162 	u_int32_t       tcps_unused_2;
1163 	u_int32_t       tcps_unused_3;
1164 
1165 	/* MPTCP Related stats */
1166 	u_int32_t       tcps_invalid_mpcap;     /* Invalid MPTCP capable opts */
1167 	u_int32_t       tcps_invalid_joins;     /* Invalid MPTCP joins */
1168 	u_int32_t       tcps_mpcap_fallback;    /* TCP fallback in primary */
1169 	u_int32_t       tcps_join_fallback;     /* No MPTCP in secondary */
1170 	u_int32_t       tcps_estab_fallback;    /* DSS option dropped */
1171 	u_int32_t       tcps_invalid_opt;       /* Catchall error stat */
1172 	u_int32_t       tcps_mp_outofwin;       /* Packet lies outside the
1173 	                                         *  shared recv window */
1174 	u_int32_t       tcps_mp_reducedwin;     /* Reduced subflow window */
1175 	u_int32_t       tcps_mp_badcsum;        /* Bad DSS csum */
1176 	u_int32_t       tcps_mp_oodata;         /* Out of order data */
1177 	u_int32_t       tcps_mp_switches;       /* number of subflow switch */
1178 	u_int32_t       tcps_mp_rcvtotal;       /* number of rcvd packets */
1179 	u_int32_t       tcps_mp_rcvbytes;       /* number of bytes received */
1180 	u_int32_t       tcps_mp_sndpacks;       /* number of data packs sent */
1181 	u_int32_t       tcps_mp_sndbytes;       /* number of bytes sent */
1182 	u_int32_t       tcps_join_rxmts;        /* join ack retransmits */
1183 	u_int32_t       tcps_tailloss_rto;      /* RTO due to tail loss */
1184 	u_int32_t       tcps_reordered_pkts;    /* packets reorderd */
1185 	u_int32_t       tcps_recovered_pkts;    /* recovered after loss */
1186 	u_int32_t       tcps_pto;               /* probe timeout */
1187 	u_int32_t       tcps_rto_after_pto;     /* RTO after a probe */
1188 	u_int32_t       tcps_tlp_recovery;      /* TLP induced fast recovery */
1189 	u_int32_t       tcps_tlp_recoverlastpkt; /* TLP recoverd last pkt */
1190 	u_int32_t       tcps_ecn_client_success; /* client-side connection negotiated ECN */
1191 	u_int32_t       tcps_ecn_recv_ece;      /* ECE received, sent CWR */
1192 	u_int32_t       tcps_ecn_sent_ece;      /* Sent ECE notification */
1193 	u_int32_t       tcps_detect_reordering; /* Detect pkt reordering */
1194 	u_int32_t       tcps_delay_recovery;    /* Delay fast recovery */
1195 	u_int32_t       tcps_avoid_rxmt;        /* Retransmission was avoided */
1196 	u_int32_t       tcps_unnecessary_rxmt;  /* Retransmission was not needed */
1197 	u_int32_t       tcps_nostretchack;      /* disabled stretch ack algorithm on a connection */
1198 	u_int32_t       tcps_rescue_rxmt;       /* SACK rescue retransmit */
1199 	u_int32_t       tcps_pto_in_recovery;   /* rescue retransmit in fast recovery */
1200 	u_int32_t       tcps_pmtudbh_reverted;  /* PMTU Blackhole detection, segment size reverted */
1201 
1202 	/* DSACK related statistics */
1203 	u_int32_t       tcps_dsack_disable;     /* DSACK disabled due to n/w duplication */
1204 	u_int32_t       tcps_dsack_ackloss;     /* ignore DSACK due to ack loss */
1205 	u_int32_t       tcps_dsack_badrexmt;    /* DSACK based bad rexmt recovery */
1206 	u_int32_t       tcps_dsack_sent;        /* Sent DSACK notification */
1207 	u_int32_t       tcps_dsack_recvd;       /* Received a valid DSACK option */
1208 	u_int32_t       tcps_dsack_recvd_old;   /* Received an out of window DSACK option */
1209 
1210 	/* MPTCP Subflow selection stats */
1211 	u_int32_t       tcps_mp_sel_symtomsd;   /* By symptomsd */
1212 	u_int32_t       tcps_mp_sel_rtt;        /* By RTT comparison */
1213 	u_int32_t       tcps_mp_sel_rto;        /* By RTO comparison */
1214 	u_int32_t       tcps_mp_sel_peer;       /* By peer's output pattern */
1215 	u_int32_t       tcps_mp_num_probes;     /* Number of probes sent */
1216 	u_int32_t       tcps_mp_verdowngrade;   /* MPTCP version downgrade */
1217 	u_int32_t       tcps_drop_after_sleep;  /* drop after long AP sleep */
1218 	u_int32_t       tcps_probe_if;          /* probe packets after interface availability */
1219 	u_int32_t       tcps_probe_if_conflict; /* Can't send probe packets for interface */
1220 
1221 	u_int32_t       tcps_ecn_client_setup;    /* Attempted ECN setup from client side */
1222 	u_int32_t       tcps_ecn_server_setup;    /* Attempted ECN setup from server side */
1223 	u_int32_t       tcps_ecn_server_success;  /* server-side connection negotiated ECN */
1224 	u_int32_t       tcps_ecn_ace_syn_not_ect; /* received AccECN SYN packet with Not-ECT */
1225 	u_int32_t       tcps_ecn_ace_syn_ect1;    /* received AccECN SYN packet with ECT1 */
1226 	u_int32_t       tcps_ecn_ace_syn_ect0;    /* received AccECN SYN packet with ECT0 */
1227 	u_int32_t       tcps_ecn_ace_syn_ce;      /* received AccECN SYN packet with CE */
1228 	u_int32_t       tcps_ecn_lost_synack;   /* Lost SYN-ACK with ECN setup */
1229 	u_int32_t       tcps_ecn_lost_syn;      /* Lost SYN with ECN setup */
1230 	u_int32_t       tcps_ecn_not_supported; /* Server did not support ECN setup */
1231 	u_int32_t       tcps_ecn_recv_ce;       /* Received CE from the network */
1232 	u_int32_t       tcps_ecn_ace_recv_ce;   /* CE count received in ACE field */
1233 	u_int32_t       tcps_ecn_conn_recv_ce;  /* Number of connections received CE atleast once */
1234 	u_int32_t       tcps_ecn_conn_recv_ece; /* Number of connections received ECE atleast once */
1235 	u_int32_t       tcps_ecn_conn_plnoce;   /* Number of connections that received no CE and sufferred packet loss */
1236 	u_int32_t       tcps_ecn_conn_pl_ce;    /* Number of connections that received CE and sufferred packet loss */
1237 	u_int32_t       tcps_ecn_conn_nopl_ce;  /* Number of connections that received CE and sufferred no packet loss */
1238 	u_int32_t       tcps_ecn_fallback_synloss; /* Number of times we did fall back due to SYN-Loss */
1239 	u_int32_t       tcps_ecn_fallback_reorder; /* Number of times we fallback because we detected the PAWS-issue */
1240 	u_int32_t       tcps_ecn_fallback_ce;   /* Number of times we fallback because we received too many CEs */
1241 
1242 	/* TFO-related statistics */
1243 	u_int32_t       tcps_tfo_syn_data_rcv;  /* Received a SYN+data with valid cookie */
1244 	u_int32_t       tcps_tfo_cookie_req_rcv;/* Received a TFO cookie-request */
1245 	u_int32_t       tcps_tfo_cookie_sent;   /* Offered a TFO-cookie to the client */
1246 	u_int32_t       tcps_tfo_cookie_invalid;/* Received an invalid TFO-cookie */
1247 	u_int32_t       tcps_tfo_cookie_req;    /* Cookie requested with the SYN */
1248 	u_int32_t       tcps_tfo_cookie_rcv;    /* Cookie received in a SYN/ACK */
1249 	u_int32_t       tcps_tfo_syn_data_sent; /* SYN+data+cookie sent */
1250 	u_int32_t       tcps_tfo_syn_data_acked;/* SYN+data has been acknowledged */
1251 	u_int32_t       tcps_tfo_syn_loss;      /* SYN+TFO has been lost and we fallback */
1252 	u_int32_t       tcps_tfo_blackhole;     /* TFO got blackholed by a middlebox. */
1253 	u_int32_t       tcps_tfo_cookie_wrong;  /* TFO-cookie we sent was wrong */
1254 	u_int32_t       tcps_tfo_no_cookie_rcv; /* We asked for a cookie but didn't get one */
1255 	u_int32_t       tcps_tfo_heuristics_disable; /* TFO got disabled due to heuristics */
1256 	u_int32_t       tcps_tfo_sndblackhole;  /* TFO got blackholed in the sending direction */
1257 	u_int32_t       tcps_mss_to_default;    /* Change MSS to default using link status report */
1258 	u_int32_t       tcps_mss_to_medium;     /* Change MSS to medium using link status report */
1259 	u_int32_t       tcps_mss_to_low;        /* Change MSS to low using link status report */
1260 	u_int32_t       tcps_ecn_fallback_droprst; /* ECN fallback caused by connection drop due to RST */
1261 	u_int32_t       tcps_ecn_fallback_droprxmt; /* ECN fallback due to drop after multiple retransmits */
1262 	u_int32_t       tcps_ecn_fallback_synrst; /* ECN fallback due to rst after syn */
1263 
1264 	u_int32_t       tcps_mptcp_rcvmemdrop;  /* MPTCP packets dropped for lack of memory */
1265 	u_int32_t       tcps_mptcp_rcvduppack;  /* MPTCP duplicate-only packets received */
1266 	u_int32_t       tcps_mptcp_rcvpackafterwin; /* MPTCP packets with data after window */
1267 
1268 	/* TCP timer statistics */
1269 	u_int32_t       tcps_timer_drift_le_1_ms;       /* Timer drift less or equal to 1 ms */
1270 	u_int32_t       tcps_timer_drift_le_10_ms;      /* Timer drift less or equal to 10 ms */
1271 	u_int32_t       tcps_timer_drift_le_20_ms;      /* Timer drift less or equal to 20 ms */
1272 	u_int32_t       tcps_timer_drift_le_50_ms;      /* Timer drift less or equal to 50 ms */
1273 	u_int32_t       tcps_timer_drift_le_100_ms;     /* Timer drift less or equal to 100 ms */
1274 	u_int32_t       tcps_timer_drift_le_200_ms;     /* Timer drift less or equal to 200 ms */
1275 	u_int32_t       tcps_timer_drift_le_500_ms;     /* Timer drift less or equal to 500 ms */
1276 	u_int32_t       tcps_timer_drift_le_1000_ms;    /* Timer drift less or equal to 1000 ms */
1277 	u_int32_t       tcps_timer_drift_gt_1000_ms;    /* Timer drift greater than 1000 ms */
1278 
1279 	u_int32_t       tcps_mptcp_handover_attempt;    /* Total number of MPTCP-attempts using handover mode */
1280 	u_int32_t       tcps_mptcp_interactive_attempt; /* Total number of MPTCP-attempts using interactive mode */
1281 	u_int32_t       tcps_mptcp_aggregate_attempt;   /* Total number of MPTCP-attempts using aggregate mode */
1282 	u_int32_t       tcps_mptcp_fp_handover_attempt; /* Same as previous three but only for first-party apps */
1283 	u_int32_t       tcps_mptcp_fp_interactive_attempt;
1284 	u_int32_t       tcps_mptcp_fp_aggregate_attempt;
1285 	u_int32_t       tcps_mptcp_heuristic_fallback;  /* Total number of MPTCP-connections that fell back due to heuristics */
1286 	u_int32_t       tcps_mptcp_fp_heuristic_fallback;       /* Same as previous but for first-party apps */
1287 	u_int32_t       tcps_mptcp_handover_success_wifi;       /* Total number of successfull handover-mode connections that *started* on WiFi */
1288 	u_int32_t       tcps_mptcp_handover_success_cell;       /* Total number of successfull handover-mode connections that *started* on Cell */
1289 	u_int32_t       tcps_mptcp_interactive_success;         /* Total number of interactive-mode connections that negotiated MPTCP */
1290 	u_int32_t       tcps_mptcp_aggregate_success;           /* Same as previous but for aggregate */
1291 	u_int32_t       tcps_mptcp_fp_handover_success_wifi;    /* Same as previous four, but for first-party apps */
1292 	u_int32_t       tcps_mptcp_fp_handover_success_cell;
1293 	u_int32_t       tcps_mptcp_fp_interactive_success;
1294 	u_int32_t       tcps_mptcp_fp_aggregate_success;
1295 	u_int32_t       tcps_mptcp_handover_cell_from_wifi;     /* Total number of connections that use cell in handover-mode (coming from WiFi) */
1296 	u_int32_t       tcps_mptcp_handover_wifi_from_cell;     /* Total number of connections that use WiFi in handover-mode (coming from cell) */
1297 	u_int32_t       tcps_mptcp_interactive_cell_from_wifi;  /* Total number of connections that use cell in interactive mode (coming from WiFi) */
1298 	u_int64_t       tcps_mptcp_handover_cell_bytes;         /* Total number of bytes sent on cell in handover-mode (on new subflows, ignoring initial one) */
1299 	u_int64_t       tcps_mptcp_interactive_cell_bytes;      /* Same as previous but for interactive */
1300 	u_int64_t       tcps_mptcp_aggregate_cell_bytes;
1301 	u_int64_t       tcps_mptcp_handover_all_bytes;          /* Total number of bytes sent in handover */
1302 	u_int64_t       tcps_mptcp_interactive_all_bytes;
1303 	u_int64_t       tcps_mptcp_aggregate_all_bytes;
1304 	u_int32_t       tcps_mptcp_back_to_wifi;        /* Total number of connections that succeed to move traffic away from cell (when starting on cell) */
1305 	u_int32_t       tcps_mptcp_wifi_proxy;          /* Total number of new subflows that fell back to regular TCP on cell */
1306 	u_int32_t       tcps_mptcp_cell_proxy;          /* Total number of new subflows that fell back to regular TCP on WiFi */
1307 
1308 	/* TCP offload statistics */
1309 	u_int32_t       tcps_ka_offload_drops;  /* Keep alive drops for timeout reported by firmware */
1310 
1311 	u_int32_t       tcps_mptcp_triggered_cell;      /* Total number of times an MPTCP-connection triggered cell bringup */
1312 
1313 	u_int32_t       tcps_fin_timeout_drops;
1314 };
1315 
1316 
1317 struct tcpstat_local {
1318 	u_int64_t badformat;
1319 	u_int64_t unspecv6;
1320 	u_int64_t synfin;
1321 	u_int64_t badformatipsec;
1322 	u_int64_t noconnnolist;
1323 	u_int64_t noconnlist;
1324 	u_int64_t listbadsyn;
1325 	u_int64_t icmp6unreach;
1326 	u_int64_t deprecate6;
1327 	u_int64_t ooopacket;
1328 	u_int64_t rstinsynrcv;
1329 	u_int64_t dospacket;
1330 	u_int64_t cleanup;
1331 	u_int64_t synwindow;
1332 };
1333 
1334 #pragma pack(4)
1335 
1336 /*
1337  * TCB structure exported to user-land via sysctl(3).
1338  * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
1339  * included.  Not all of our clients do.
1340  */
1341 
1342 struct  xtcpcb {
1343 	u_int32_t       xt_len;
1344 #ifdef KERNEL_PRIVATE
1345 	struct  inpcb_compat    xt_inp;
1346 #else
1347 	struct  inpcb   xt_inp;
1348 #endif
1349 #ifdef KERNEL_PRIVATE
1350 	struct  otcpcb  xt_tp;
1351 #else
1352 	struct  tcpcb   xt_tp;
1353 #endif
1354 	struct  xsocket xt_socket;
1355 	u_quad_t        xt_alignment_hack;
1356 };
1357 
1358 #if XNU_TARGET_OS_OSX || KERNEL || !(TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR)
1359 
1360 struct  xtcpcb64 {
1361 	u_int32_t               xt_len;
1362 	struct xinpcb64         xt_inpcb;
1363 
1364 	u_int64_t t_segq;
1365 	int     t_dupacks;              /* consecutive dup acks recd */
1366 
1367 	int t_timer[TCPT_NTIMERS_EXT];  /* tcp timers */
1368 
1369 	int     t_state;                /* state of this connection */
1370 	u_int   t_flags;
1371 
1372 	int     t_force;                /* 1 if forcing out a byte */
1373 
1374 	tcp_seq snd_una;                /* send unacknowledged */
1375 	tcp_seq snd_max;                /* highest sequence number sent;
1376 	                                 * used to recognize retransmits
1377 	                                 */
1378 	tcp_seq snd_nxt;                /* send next */
1379 	tcp_seq snd_up;                 /* send urgent pointer */
1380 
1381 	tcp_seq snd_wl1;                /* window update seg seq number */
1382 	tcp_seq snd_wl2;                /* window update seg ack number */
1383 	tcp_seq iss;                    /* initial send sequence number */
1384 	tcp_seq irs;                    /* initial receive sequence number */
1385 
1386 	tcp_seq rcv_nxt;                /* receive next */
1387 	tcp_seq rcv_adv;                /* advertised window */
1388 	u_int32_t rcv_wnd;              /* receive window */
1389 	tcp_seq rcv_up;                 /* receive urgent pointer */
1390 
1391 	u_int32_t snd_wnd;              /* send window */
1392 	u_int32_t snd_cwnd;             /* congestion-controlled window */
1393 	u_int32_t snd_ssthresh;         /* snd_cwnd size threshold for
1394 	                                 * for slow start exponential to
1395 	                                 * linear switch
1396 	                                 */
1397 	u_int   t_maxopd;               /* mss plus options */
1398 
1399 	u_int32_t t_rcvtime;            /* time at which a packet was received */
1400 	u_int32_t t_starttime;          /* time connection was established */
1401 	int     t_rtttime;              /* round trip time */
1402 	tcp_seq t_rtseq;                /* sequence number being timed */
1403 
1404 	int     t_rxtcur;               /* current retransmit value (ticks) */
1405 	u_int   t_maxseg;               /* maximum segment size */
1406 	int     t_srtt;                 /* smoothed round-trip time */
1407 	int     t_rttvar;               /* variance in round-trip time */
1408 
1409 	int     t_rxtshift;             /* log(2) of rexmt exp. backoff */
1410 	u_int   t_rttmin;               /* minimum rtt allowed */
1411 	u_int32_t t_rttupdated;         /* number of times rtt sampled */
1412 	u_int32_t max_sndwnd;           /* largest window peer has offered */
1413 
1414 	int     t_softerror;            /* possible error not yet reported */
1415 /* out-of-band data */
1416 	char    t_oobflags;             /* have some */
1417 	char    t_iobc;                 /* input character */
1418 /* RFC 1323 variables */
1419 	u_char  snd_scale;              /* window scaling for send window */
1420 	u_char  rcv_scale;              /* window scaling for recv window */
1421 	u_char  request_r_scale;        /* pending window scaling */
1422 	u_char  requested_s_scale;
1423 	u_int32_t ts_recent;            /* timestamp echo data */
1424 
1425 	u_int32_t ts_recent_age;        /* when last updated */
1426 	tcp_seq last_ack_sent;
1427 /* RFC 1644 variables */
1428 	tcp_cc  cc_send;                /* send connection count */
1429 	tcp_cc  cc_recv;                /* receive connection count */
1430 	tcp_seq snd_recover;            /* for use in fast recovery */
1431 /* experimental */
1432 	u_int32_t snd_cwnd_prev;        /* cwnd prior to retransmit */
1433 	u_int32_t snd_ssthresh_prev;    /* ssthresh prior to retransmit */
1434 	u_int32_t t_badrxtwin;          /* window for retransmit recovery */
1435 
1436 	u_quad_t                xt_alignment_hack;
1437 };
1438 
1439 #endif /* XNU_TARGET_OS_OSX || KERNEL || !(TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR) */
1440 
1441 #ifdef PRIVATE
1442 
1443 struct  xtcpcb_n {
1444 	u_int32_t               xt_len;
1445 	u_int32_t                       xt_kind;                /* XSO_TCPCB */
1446 
1447 	u_int64_t t_segq;
1448 	int     t_dupacks;              /* consecutive dup acks recd */
1449 
1450 	int t_timer[TCPT_NTIMERS_EXT];  /* tcp timers */
1451 
1452 	int     t_state;                /* state of this connection */
1453 	u_int   t_flags;
1454 
1455 	int     t_force;                /* 1 if forcing out a byte */
1456 
1457 	tcp_seq snd_una;                /* send unacknowledged */
1458 	tcp_seq snd_max;                /* highest sequence number sent;
1459 	                                 * used to recognize retransmits
1460 	                                 */
1461 	tcp_seq snd_nxt;                /* send next */
1462 	tcp_seq snd_up;                 /* send urgent pointer */
1463 
1464 	tcp_seq snd_wl1;                /* window update seg seq number */
1465 	tcp_seq snd_wl2;                /* window update seg ack number */
1466 	tcp_seq iss;                    /* initial send sequence number */
1467 	tcp_seq irs;                    /* initial receive sequence number */
1468 
1469 	tcp_seq rcv_nxt;                /* receive next */
1470 	tcp_seq rcv_adv;                /* advertised window */
1471 	u_int32_t rcv_wnd;              /* receive window */
1472 	tcp_seq rcv_up;                 /* receive urgent pointer */
1473 
1474 	u_int32_t snd_wnd;              /* send window */
1475 	u_int32_t snd_cwnd;             /* congestion-controlled window */
1476 	u_int32_t snd_ssthresh;         /* snd_cwnd size threshold for
1477 	                                 * for slow start exponential to
1478 	                                 * linear switch
1479 	                                 */
1480 	u_int   t_maxopd;               /* mss plus options */
1481 
1482 	u_int32_t t_rcvtime;            /* time at which a packet was received */
1483 	u_int32_t t_starttime;          /* time connection was established */
1484 	int     t_rtttime;              /* round trip time */
1485 	tcp_seq t_rtseq;                /* sequence number being timed */
1486 
1487 	int     t_rxtcur;               /* current retransmit value (ticks) */
1488 	u_int   t_maxseg;               /* maximum segment size */
1489 	int     t_srtt;                 /* smoothed round-trip time */
1490 	int     t_rttvar;               /* variance in round-trip time */
1491 
1492 	int     t_rxtshift;             /* log(2) of rexmt exp. backoff */
1493 	u_int   t_rttmin;               /* minimum rtt allowed */
1494 	u_int32_t t_rttupdated;         /* number of times rtt sampled */
1495 	u_int32_t max_sndwnd;           /* largest window peer has offered */
1496 
1497 	int     t_softerror;            /* possible error not yet reported */
1498 	/* out-of-band data */
1499 	char    t_oobflags;             /* have some */
1500 	char    t_iobc;                 /* input character */
1501 	/* RFC 1323 variables */
1502 	u_char  snd_scale;              /* window scaling for send window */
1503 	u_char  rcv_scale;              /* window scaling for recv window */
1504 	u_char  request_r_scale;        /* pending window scaling */
1505 	u_char  requested_s_scale;
1506 	u_int32_t ts_recent;            /* timestamp echo data */
1507 
1508 	u_int32_t ts_recent_age;        /* when last updated */
1509 	tcp_seq last_ack_sent;
1510 	/* RFC 1644 variables */
1511 	tcp_cc  cc_send;                /* send connection count */
1512 	tcp_cc  cc_recv;                /* receive connection count */
1513 	tcp_seq snd_recover;            /* for use in fast recovery */
1514 	/* experimental */
1515 	u_int32_t snd_cwnd_prev;        /* cwnd prior to retransmit */
1516 	u_int32_t snd_ssthresh_prev;    /* ssthresh prior to retransmit */
1517 };
1518 
1519 /*
1520  * The rtt measured is in milliseconds as the timestamp granularity is
1521  * a millisecond. The smoothed round-trip time and estimated variance
1522  * are stored as fixed point numbers scaled by the values below.
1523  * For convenience, these scales are also used in smoothing the average
1524  * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
1525  * With these scales, srtt has 5 bits to the right of the binary point,
1526  * and thus an "ALPHA" of 0.875.  rttvar has 4 bits to the right of the
1527  * binary point, and is smoothed with an ALPHA of 0.75.
1528  */
1529 #define TCP_RTT_SCALE           32      /* multiplier for srtt; 3 bits frac. */
1530 #define TCP_RTT_SHIFT           5       /* shift for srtt; 5 bits frac. */
1531 #define TCP_RTTVAR_SCALE        16      /* multiplier for rttvar; 4 bits */
1532 #define TCP_RTTVAR_SHIFT        4       /* shift for rttvar; 4 bits */
1533 #define TCP_DELTA_SHIFT         2       /* see tcp_input.c */
1534 
1535 
1536 /*
1537  * TCP structure with information that gives insight into forward progress on an interface,
1538  * exported to user-land via sysctl(3).
1539  */
1540 struct  xtcpprogress_indicators {
1541 	u_int32_t       xp_numflows;            /* Total number of flows */
1542 	u_int32_t       xp_conn_probe_fails;    /* Count of connection failures */
1543 	u_int32_t       xp_read_probe_fails;    /* Count of read probe failures */
1544 	u_int32_t       xp_write_probe_fails;   /* Count of write failures */
1545 	u_int32_t       xp_recentflows;         /* Total of "recent" flows */
1546 	u_int32_t       xp_recentflows_unacked; /* Total of "recent" flows with unacknowledged data */
1547 	u_int64_t       xp_recentflows_rxbytes; /* Total of "recent" flows received bytes */
1548 	u_int64_t       xp_recentflows_txbytes; /* Total of "recent" flows transmitted bytes */
1549 	u_int64_t       xp_recentflows_rxooo;   /* Total of "recent" flows received out of order bytes */
1550 	u_int64_t       xp_recentflows_rxdup;   /* Total of "recent" flows received duplicate bytes */
1551 	u_int64_t       xp_recentflows_retx;    /* Total of "recent" flows retransmitted bytes */
1552 	u_int64_t       xp_reserved1;           /* Expansion */
1553 	u_int64_t       xp_reserved2;           /* Expansion */
1554 	u_int64_t       xp_reserved3;           /* Expansion */
1555 	u_int64_t       xp_reserved4;           /* Expansion */
1556 };
1557 
1558 struct tcpprogressreq {
1559 	u_int64_t       ifindex;                /* Interface index for progress indicators */
1560 	u_int64_t       recentflow_maxduration; /* In mach_absolute_time, max duration for flow to be counted as "recent" */
1561 	u_int64_t       filter_flags;           /* Optional additional filtering, values are interface properties per ntstat.h */
1562 	u_int64_t       xp_reserved2;           /* Expansion */
1563 };
1564 
1565 struct tcpprobereq {
1566 	u_int64_t       ifindex;                /* Optional interface index for TCP keep-alive probing */
1567 	u_int64_t       enable;                 /* Flag to enable or disable probing (1=on, 0=off)*/
1568 	u_int64_t       filter_flags;           /* Optional flags for filtering interfaces per ntstat.h (NSTAT_IFNET_IS_*) */
1569 	u_int32_t       reserved;               /* Expansion */
1570 	u_int32_t       reserved2;              /* Expansion */
1571 };
1572 
1573 #endif /* PRIVATE */
1574 
1575 #pragma pack()
1576 
1577 /*
1578  * Names for TCP sysctl objects
1579  */
1580 #define TCPCTL_DO_RFC1323       1       /* use RFC-1323 extensions */
1581 #define TCPCTL_DO_RFC1644       2       /* use RFC-1644 extensions */
1582 #define TCPCTL_MSSDFLT          3       /* MSS default */
1583 #define TCPCTL_STATS            4       /* statistics (read-only) */
1584 #define TCPCTL_RTTDFLT          5       /* default RTT estimate */
1585 #define TCPCTL_KEEPIDLE         6       /* keepalive idle timer */
1586 #define TCPCTL_KEEPINTVL        7       /* interval to send keepalives */
1587 #define TCPCTL_SENDSPACE        8       /* send buffer space */
1588 #define TCPCTL_RECVSPACE        9       /* receive buffer space */
1589 #define TCPCTL_KEEPINIT         10      /* timeout for establishing syn */
1590 #define TCPCTL_PCBLIST          11      /* list of all outstanding PCBs */
1591 #define TCPCTL_DELACKTIME       12      /* time before sending delayed ACK */
1592 #define TCPCTL_V6MSSDFLT        13      /* MSS default for IPv6 */
1593 #define TCPCTL_MAXID            14
1594 
1595 #ifdef BSD_KERNEL_PRIVATE
1596 #include <sys/bitstring.h>
1597 
1598 #define TCP_PKTLIST_CLEAR(tp) {                                         \
1599 	(tp)->t_pktlist_head = (tp)->t_pktlist_tail = NULL;             \
1600 	(tp)->t_lastchain = (tp)->t_pktlist_sentlen = 0;                \
1601 }
1602 
1603 extern int tcp_TCPTV_MIN;
1604 
1605 #ifdef SYSCTL_DECL
1606 SYSCTL_DECL(_net_inet_tcp);
1607 #endif /* SYSCTL_DECL */
1608 
1609 extern  struct inpcbhead tcb;           /* head of queue of active tcpcb's */
1610 extern  struct inpcbinfo tcbinfo;
1611 extern  struct tcpstat tcpstat; /* tcp statistics */
1612 extern  int tcp_mssdflt;        /* XXX */
1613 extern  int tcp_minmss;
1614 #define TCP_FASTOPEN_SERVER 0x01
1615 #define TCP_FASTOPEN_CLIENT 0x02
1616 
1617 extern int tcp_tfo_halfcnt;
1618 extern int tcp_tfo_backlog;
1619 extern int tcp_fastopen;
1620 extern int ss_fltsz_local;
1621 extern int target_qdelay;
1622 extern u_int32_t tcp_now;               /* for RFC 1323 timestamps */
1623 extern struct timeval tcp_uptime;
1624 extern lck_spin_t tcp_uptime_lock;
1625 extern int tcp_delack_enabled;
1626 extern int maxseg_unacked;
1627 KALLOC_TYPE_DECLARE(tcp_reass_zone);
1628 KALLOC_TYPE_DECLARE(tcp_rxt_seg_zone);
1629 extern int tcp_ecn_outbound;
1630 extern int tcp_ecn_inbound;
1631 extern uint32_t tcp_do_autorcvbuf;
1632 extern uint32_t tcp_autorcvbuf_max;
1633 extern int tcp_recv_bg;
1634 extern int tcp_do_ack_compression;
1635 extern int tcp_randomize_timestamps;
1636 extern int tcp_rledbat;
1637 extern int tcp_use_min_curr_rtt;
1638 extern int tcp_do_timestamps;
1639 /*
1640  * Dummy value used for when there is no flow and we want to ensure that compression
1641  * can happen.
1642  */
1643 #define TCP_ACK_COMPRESSION_DUMMY 1
1644 
1645 extern int tcp_do_better_lr;
1646 extern int tcp_cubic_minor_fixes;
1647 extern int tcp_cubic_rfc_compliant;
1648 extern int tcp_flow_control_response;
1649 
1650 extern int tcp_reass_total_qlen;
1651 
1652 struct protosw;
1653 struct domain;
1654 
1655 struct tcp_respond_args {
1656 	unsigned int ifscope;
1657 	unsigned int nocell:1,
1658 	    noexpensive:1,
1659 	    awdl_unrestricted:1,
1660 	    intcoproc_allowed:1,
1661 	    keep_alive:1,
1662 	    noconstrained:1,
1663 	    management_allowed:1;
1664 };
1665 
1666 void     tcp_canceltimers(struct tcpcb *);
1667 struct tcpcb *
1668 tcp_close(struct tcpcb *);
1669 void     tcp_ctlinput(int, struct sockaddr *, void *, struct ifnet *);
1670 int      tcp_ctloutput(struct socket *, struct sockopt *);
1671 struct tcpcb *
1672 tcp_drop(struct tcpcb *, int);
1673 void     tcp_drain(void);
1674 void     tcp_getrt_rtt(struct tcpcb *tp, struct rtentry *rt);
1675 void     tcp_init(struct protosw *, struct domain *);
1676 void     tcp_input(struct mbuf *, int);
1677 void     tcp_mss(struct tcpcb *, int, unsigned int);
1678 uint32_t tcp_ceil(double a);
1679 uint32_t tcp_round_to(uint32_t val, uint32_t round);
1680 uint32_t tcp_round_up(uint32_t val, uint32_t base);
1681 int      tcp_mssopt(struct tcpcb *);
1682 void     tcp_drop_syn_sent(struct inpcb *, int);
1683 void     tcp_mtudisc(struct inpcb *, int);
1684 struct tcpcb *
1685 tcp_newtcpcb(struct inpcb *);
1686 int      tcp_output(struct tcpcb *);
1687 void     tcp_respond(struct tcpcb *, void *, struct tcphdr *, struct mbuf *,
1688     tcp_seq, tcp_seq, uint8_t, struct tcp_respond_args *);
1689 struct rtentry *
1690 tcp_rtlookup(struct inpcb *, unsigned int);
1691 void     tcp_setpersist(struct tcpcb *);
1692 void     tcp_gc(struct inpcbinfo *);
1693 void     tcp_itimer(struct inpcbinfo *ipi);
1694 void     tcp_check_timer_state(struct tcpcb *tp);
1695 void     tcp_run_timerlist(void *arg1, void *arg2);
1696 void     tcp_sched_timers(struct tcpcb *tp);
1697 
1698 struct tcptemp *tcp_maketemplate(struct tcpcb *, struct mbuf **);
1699 void     tcp_fillheaders(struct mbuf *, struct tcpcb *, void *, void *);
1700 struct tcpcb *tcp_timers(struct tcpcb *, int);
1701 void     tcp_trace(int, int, struct tcpcb *, void *, struct tcphdr *, int);
1702 
1703 void tcp_fill_info(struct tcpcb *, struct tcp_info *);
1704 void tcp_sack_doack(struct tcpcb *, struct tcpopt *, struct tcphdr *,
1705     u_int32_t *, uint32_t *);
1706 extern boolean_t tcp_sack_process_dsack(struct tcpcb *, struct tcpopt *,
1707     struct tcphdr *);
1708 int tcp_detect_bad_rexmt(struct tcpcb *, struct tcphdr *, struct tcpopt *,
1709     u_int32_t rxtime);
1710 void     tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend);
1711 void     tcp_clean_sackreport(struct tcpcb *tp);
1712 uint32_t tcp_sack_adjust(struct tcpcb *tp);
1713 struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt);
1714 void     tcp_sack_partialack(struct tcpcb *, struct tcphdr *);
1715 void     tcp_free_sackholes(struct tcpcb *tp);
1716 void     tcp_sack_lost_rexmit(struct tcpcb *tp);
1717 int32_t  tcp_sbspace(struct tcpcb *tp);
1718 void     tcp_set_tso(struct tcpcb *tp, struct ifnet *ifp);
1719 void     tcp_set_ecn(struct tcpcb *tp, struct ifnet *ifp);
1720 uint8_t  tcp_get_ace(struct tcphdr *th);
1721 int      tcp_flight_size(struct tcpcb *tp);
1722 void     tcp_reset_stretch_ack(struct tcpcb *tp);
1723 extern void tcp_get_ports_used(ifnet_t ifp, int, u_int32_t, bitstr_t *);
1724 uint32_t tcp_count_opportunistic(unsigned int ifindex, u_int32_t flags);
1725 uint32_t tcp_find_anypcb_byaddr(struct ifaddr *ifa);
1726 void tcp_set_max_rwinscale(struct tcpcb *tp, struct socket *so);
1727 struct bwmeas* tcp_bwmeas_alloc(struct tcpcb *tp);
1728 void tcp_bwmeas_free(struct tcpcb *tp);
1729 extern int32_t timer_diff(uint32_t t1, uint32_t toff1, uint32_t t2, uint32_t toff2);
1730 
1731 extern void tcp_set_background_cc(struct socket *);
1732 extern void tcp_set_foreground_cc(struct socket *);
1733 extern void tcp_set_recv_bg(struct socket *);
1734 extern void tcp_clear_recv_bg(struct socket *);
1735 extern boolean_t tcp_sack_byte_islost(struct tcpcb *tp);
1736 #define IS_TCP_RECV_BG(_so)     \
1737 	((_so)->so_flags1 & SOF1_TRAFFIC_MGT_TCP_RECVBG)
1738 
1739 #if TRAFFIC_MGT
1740 #define CLEAR_IAJ_STATE(_tp_) (_tp_)->iaj_rcv_ts = 0
1741 void     reset_acc_iaj(struct tcpcb *tp);
1742 #endif /* TRAFFIC_MGT */
1743 
1744 int      tcp_lock(struct socket *, int, void *);
1745 int      tcp_unlock(struct socket *, int, void *);
1746 void     calculate_tcp_clock(void);
1747 
1748 extern void tcp_keepalive_reset(struct tcpcb *);
1749 extern uint32_t get_base_rtt(struct tcpcb *tp);
1750 
1751 #ifdef _KERN_LOCKS_H_
1752 lck_mtx_t *      tcp_getlock(struct socket *, int);
1753 #else
1754 void *   tcp_getlock(struct socket *, int);
1755 #endif
1756 
1757 extern  struct pr_usrreqs tcp_usrreqs;
1758 extern  u_int32_t tcp_sendspace;
1759 extern  u_int32_t tcp_recvspace;
1760 tcp_seq tcp_new_isn(struct tcpcb *);
1761 
1762 extern int tcp_input_checksum(int, struct mbuf *, struct tcphdr *, int, int);
1763 extern void tcp_getconninfo(struct socket *, struct conninfo_tcp *);
1764 extern void add_to_time_wait(struct tcpcb *, uint32_t delay);
1765 extern void add_to_time_wait_now(struct tcpcb *tp, uint32_t delay);
1766 extern void tcp_pmtud_revert_segment_size(struct tcpcb *tp);
1767 extern void tcp_rxtseg_insert(struct tcpcb *, tcp_seq, tcp_seq);
1768 extern struct tcp_rxt_seg *tcp_rxtseg_find(struct tcpcb *, tcp_seq, tcp_seq);
1769 extern void tcp_rxtseg_set_spurious(struct tcpcb *tp, tcp_seq start, tcp_seq end);
1770 extern void tcp_rxtseg_clean(struct tcpcb *);
1771 extern boolean_t tcp_rxtseg_detect_bad_rexmt(struct tcpcb *, tcp_seq);
1772 extern boolean_t tcp_rxtseg_dsack_for_tlp(struct tcpcb *);
1773 extern u_int32_t tcp_rxtseg_total_size(struct tcpcb *tp);
1774 extern void tcp_rexmt_save_state(struct tcpcb *tp);
1775 extern void tcp_interface_send_probe(u_int16_t if_index_available);
1776 extern void tcp_probe_connectivity(struct ifnet *ifp, u_int32_t enable);
1777 extern void tcp_get_connectivity_status(struct tcpcb *,
1778     struct tcp_conn_status *);
1779 
1780 extern void tcp_clear_keep_alive_offload(struct socket *so);
1781 extern void tcp_fill_keepalive_offload_frames(struct ifnet *,
1782     struct ifnet_keepalive_offload_frame *, u_int32_t, size_t, u_int32_t *);
1783 extern int tcp_notify_kao_timeout(ifnet_t ifp,
1784     struct ifnet_keepalive_offload_frame *frame);
1785 
1786 extern boolean_t tfo_enabled(const struct tcpcb *tp);
1787 extern void tcp_disable_tfo(struct tcpcb *tp);
1788 extern void tcp_tfo_gen_cookie(struct inpcb *inp, u_char *out, size_t blk_size);
1789 #define TCP_FASTOPEN_KEYLEN 16
1790 extern int tcp_freeq(struct tcpcb *tp);
1791 extern errno_t tcp_notify_ack_id_valid(struct tcpcb *, struct socket *, u_int32_t);
1792 extern errno_t tcp_add_notify_ack_marker(struct tcpcb *, u_int32_t);
1793 extern void tcp_notify_ack_free(struct tcpcb *);
1794 extern void tcp_notify_acknowledgement(struct tcpcb *, struct socket *);
1795 extern void tcp_get_notify_ack_count(struct tcpcb *,
1796     struct tcp_notify_ack_complete *);
1797 extern void tcp_get_notify_ack_ids(struct tcpcb *tp,
1798     struct tcp_notify_ack_complete *);
1799 extern void tcp_update_mss_locked(struct socket *, struct ifnet *);
1800 
1801 extern int get_tcp_inp_list(struct inpcb **, int, inp_gen_t);
1802 extern bool tcp_notify_ack_active(struct socket *so);
1803 extern void tcp_set_finwait_timeout(struct tcpcb *);
1804 
1805 #if MPTCP
1806 extern uint16_t mptcp_output_csum(struct mbuf *m, uint64_t dss_val,
1807     uint32_t sseq, uint16_t dlen);
1808 extern int mptcp_adj_mss(struct tcpcb *, boolean_t);
1809 extern void mptcp_insert_rmap(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th);
1810 extern int dump_mptcp_reass_qlen(char *, int);
1811 #endif
1812 
1813 extern int dump_tcp_reass_qlen(char *, int);
1814 extern uint32_t tcp_reass_qlen_space(struct socket *);
1815 
1816 __private_extern__ void tcp_update_stats_per_flow(
1817 	struct ifnet_stats_per_flow *, struct ifnet *);
1818 
1819 #define TCP_ACK_STRATEGY_LEGACY 0
1820 #define TCP_ACK_STRATEGY_MODERN 1
1821 
1822 extern int tcp_ack_strategy;
1823 
1824 #if SKYWALK
1825 void tcp_add_fsw_flow(struct tcpcb *, struct ifnet *);
1826 void tcp_del_fsw_flow(struct tcpcb *);
1827 #else /* !SKYWALK */
1828 #define tcp_add_fsw_flow(...)
1829 #define tcp_del_fsw_flow(...)
1830 #endif /* !SKYWALK */
1831 
1832 #endif /* BSD_KERNEL_PRIVATE */
1833 
1834 #endif /* _NETINET_TCP_VAR_H_ */
1835