1/*
2 * Copyright (c) 2000-2013 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
7 * as defined in and that are subject to the Apple Public Source License
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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/appleapiopts.h>
67#include <sys/queue.h>
68#include <netinet/in_pcb.h>
69#include <netinet/tcp_timer.h>
70
71#if defined(__LP64__)
72#define _TCPCB_PTR(x)			u_int32_t
73#define _TCPCB_LIST_HEAD(name, type)	\
74struct name {				\
75	u_int32_t	lh_first;	\
76};
77#else
78#define _TCPCB_PTR(x)			x
79#define _TCPCB_LIST_HEAD(name, type)	LIST_HEAD(name, type)
80#endif
81
82#define TCP_RETRANSHZ	1000	/* granularity of TCP timestamps, 1ms */
83#define TCP_TIMERHZ	100		/* frequency of TCP fast timer, 100 ms */
84
85/* Minimum time quantum within which the timers are coalesced */
86#define TCP_FASTTIMER_QUANTUM   TCP_TIMERHZ	/* fast mode, once every 100ms */
87#define TCP_SLOWTIMER_QUANTUM   (TCP_RETRANSHZ/2) /* slow mode, once every 500ms */
88
89#define TCP_RETRANSHZ_TO_USEC 1000
90
91#ifdef KERNEL_PRIVATE
92#define N_TIME_WAIT_SLOTS   128     	/* must be power of 2 */
93
94/* Base RTT is stored for N_MIN_RTT_HISTORY slots. This is used to
95 * estimate expected minimum RTT for delay based congestion control
96 * algorithms.
97 */
98#define N_RTT_BASE	5
99
100/* Always allow at least 4 packets worth of recv window when adjusting
101 * recv window using inter-packet arrival jitter.
102 */
103#define MIN_IAJ_WIN 4
104
105/* A variation in delay of this many milliseconds is tolerable. This limit has to
106 * be low but greater than zero. We also use standard deviation on jitter to adjust
107 * this limit for different link and connection types.
108 */
109#define ALLOWED_IAJ 5
110
111/* Ignore the first few packets on a connection until the ACK clock gets going
112 */
113#define IAJ_IGNORE_PKTCNT 40
114
115/* Let the accumulated IAJ value increase by this threshold at most. This limit
116 * will control how many ALLOWED_IAJ measurements a receiver will have to see
117 * before opening the receive window
118 */
119#define ACC_IAJ_HIGH_THRESH 100
120
121/* When accumulated IAJ reaches this value, the receiver starts to react by
122 * closing the window
123 */
124#define ACC_IAJ_REACT_LIMIT 200
125
126/* If the number of small packets (smaller than IAJ packet size) seen on a
127 * connection is more than this threshold, reset the size and learn it again.
128 * This is needed because the sender might send smaller segments after PMTU
129 * discovery and the receiver has to learn the new size.
130 */
131#define RESET_IAJ_SIZE_THRESH 20
132
133/*
134 * Adaptive timeout is a read/write timeout specified by the application to
135 * get a socket event when the transport layer detects a stall in data
136 * transfer. The value specified is the number of probes that can be sent
137 * to the peer before generating an event. Since it is not specified as
138 * a time value, the timeout will adjust based on the RTT seen on the link.
139 * The timeout will start only when there is an indication that the read/write
140 * operation is not making progress.
141 *
142 * If a write operation stalls, the probe will be retransmission of data.
143 * If a read operation stalls, the probe will be a keep-alive packet.
144 *
145 * The maximum value of adaptive timeout is set to 10 which will allow
146 * transmission of enough number of probes to the peer.
147 */
148#define TCP_ADAPTIVE_TIMEOUT_MAX 10
149
150/*
151 * Kernel variables for tcp.
152 */
153
154/* TCP segment queue entry */
155struct tseg_qent {
156	LIST_ENTRY(tseg_qent) tqe_q;
157	int	tqe_len;		/* TCP segment data length */
158	struct	tcphdr *tqe_th;		/* a pointer to tcp header */
159	struct	mbuf	*tqe_m;		/* mbuf contains packet */
160};
161LIST_HEAD(tsegqe_head, tseg_qent);
162extern int	tcp_reass_maxseg;
163extern int	tcp_reass_qsize;
164#ifdef MALLOC_DECLARE
165MALLOC_DECLARE(M_TSEGQ);
166#endif
167
168struct sackblk {
169	tcp_seq start;		/* start seq no. of sack block */
170	tcp_seq end;		/* end seq no. */
171};
172
173struct sackhole {
174	tcp_seq start;		/* start seq no. of hole */
175	tcp_seq end;		/* end seq no. */
176	tcp_seq rxmit;		/* next seq. no in hole to be retransmitted */
177	TAILQ_ENTRY(sackhole) scblink;	/* scoreboard linkage */
178};
179
180struct sackhint {
181	struct sackhole	*nexthole;
182	int	sack_bytes_rexmit;
183};
184
185struct tcptemp {
186	u_char	tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
187	struct	tcphdr tt_t;
188};
189
190struct bwmeas {
191	tcp_seq bw_start;		/* start of bw measurement */
192	uint32_t bw_ts;		/* timestamp when bw measurement started */
193	uint32_t bw_size;		/* burst size in bytes for this bw measurement */
194	uint32_t bw_minsizepkts;	/* Min burst size as segments */
195	uint32_t bw_maxsizepkts;	/* Max burst size as segments */
196	uint32_t bw_minsize;	/* Min size in bytes */
197	uint32_t bw_maxsize;	/* Max size in bytes */
198	uint32_t bw_sndbw;		/* Measured send bw */
199};
200
201/* MPTCP Data sequence map entry */
202struct mpt_dsn_map {
203	uint64_t		mpt_dsn;	/* data seq num recvd */
204	uint32_t		mpt_sseq;	/* relative subflow # */
205	uint16_t		mpt_len;	/* length of mapping */
206	uint16_t		mpt_csum;	/* checksum value if on */
207};
208#define tcp6cb		tcpcb  /* for KAME src sync over BSD*'s */
209
210/*
211 * Tcp control block, one per tcp; fields:
212 * Organized for 16 byte cacheline efficiency.
213 */
214struct tcpcb {
215	struct	tsegqe_head t_segq;
216	int	t_dupacks;		/* consecutive dup acks recd */
217	uint32_t t_timer[TCPT_NTIMERS];	/* tcp timers */
218	struct tcptimerentry tentry;	/* entry in timer list */
219
220	struct	inpcb *t_inpcb;		/* back pointer to internet pcb */
221	int	t_state;		/* state of this connection */
222	uint32_t	t_flags;
223#define	TF_ACKNOW	0x00001		/* ack peer immediately */
224#define	TF_DELACK	0x00002		/* ack, but try to delay it */
225#define	TF_NODELAY	0x00004		/* don't delay packets to coalesce */
226#define	TF_NOOPT	0x00008		/* don't use tcp options */
227#define	TF_SENTFIN	0x00010		/* have sent FIN */
228#define	TF_REQ_SCALE	0x00020		/* have/will request window scaling */
229#define	TF_RCVD_SCALE	0x00040		/* other side has requested scaling */
230#define	TF_REQ_TSTMP	0x00080		/* have/will request timestamps */
231#define	TF_RCVD_TSTMP	0x00100		/* a timestamp was received in SYN */
232#define	TF_SACK_PERMIT	0x00200		/* other side said I could SACK */
233#define	TF_NEEDSYN	0x00400		/* send SYN (implicit state) */
234#define	TF_NEEDFIN	0x00800		/* send FIN (implicit state) */
235#define	TF_NOPUSH	0x01000		/* don't push */
236#define	TF_REQ_CC	0x02000		/* have/will request CC */
237#define	TF_RCVD_CC	0x04000		/* a CC was received in SYN */
238#define	TF_SENDCCNEW	0x08000		/* send CCnew instead of CC in SYN */
239#define	TF_MORETOCOME	0x10000		/* More data to be appended to sock */
240#define	TF_LOCAL	0x20000		/* connection to a host on local link */
241#define	TF_RXWIN0SENT	0x40000		/* sent a receiver win 0 in response */
242#define	TF_SLOWLINK	0x80000		/* route is a on a modem speed link */
243#define	TF_LASTIDLE	0x100000	/* connection was previously idle */
244#define	TF_FASTRECOVERY	0x200000	/* in NewReno Fast Recovery */
245#define	TF_WASFRECOVERY	0x400000	/* was in NewReno Fast Recovery */
246#define	TF_SIGNATURE	0x800000	/* require MD5 digests (RFC2385) */
247#define	TF_MAXSEGSNT	0x1000000	/* last segment sent was a full segment */
248#define TF_PMTUD	0x4000000	/* Perform Path MTU Discovery for this connection */
249#define	TF_CLOSING	0x8000000	/* pending tcp close */
250#define TF_TSO		0x10000000	/* TCP Segment Offloading is enable on this connection */
251#define TF_BLACKHOLE	0x20000000	/* Path MTU Discovery Black Hole detection */
252#define TF_TIMER_ONLIST 0x40000000	/* pcb is on tcp_timer_list */
253#define TF_STRETCHACK	0x80000000	/* receiver is going to delay acks */
254
255	int	t_force;		/* 1 if forcing out a byte */
256
257	tcp_seq	snd_una;		/* send unacknowledged */
258	tcp_seq	snd_max;		/* highest sequence number sent;
259					 * used to recognize retransmits
260					 */
261	tcp_seq	snd_nxt;		/* send next */
262	tcp_seq	snd_up;			/* send urgent pointer */
263
264	tcp_seq	snd_wl1;		/* window update seg seq number */
265	tcp_seq	snd_wl2;		/* window update seg ack number */
266	tcp_seq	iss;			/* initial send sequence number */
267	tcp_seq	irs;			/* initial receive sequence number */
268
269	tcp_seq	rcv_nxt;		/* receive next */
270	tcp_seq	rcv_adv;		/* advertised window */
271	u_int32_t	rcv_wnd;		/* receive window */
272	tcp_seq	rcv_up;			/* receive urgent pointer */
273
274	u_int32_t	snd_wnd;		/* send window */
275	u_int32_t	snd_cwnd;		/* congestion-controlled window */
276	u_int32_t	snd_ssthresh;		/* snd_cwnd size threshold for
277					 * for slow start exponential to
278					 * linear switch
279					 */
280	tcp_seq	snd_recover;		/* for use in NewReno Fast Recovery */
281
282	u_int	t_maxopd;		/* mss plus options */
283
284	u_int32_t	t_rcvtime;	/* time at which a packet was received */
285	u_int32_t	t_starttime;	/* time connection was established */
286	int	t_rtttime;		/* tcp clock when rtt calculation was started */
287	tcp_seq	t_rtseq;		/* sequence number being timed */
288
289	u_int32_t rfbuf_ts;		/* recv buffer autoscaling timestamp */
290	u_int32_t rfbuf_cnt;		/* recv buffer autoscaling byte count */
291
292	int	t_rxtcur;		/* current retransmit value (ticks) */
293	u_int	t_maxseg;		/* maximum segment size */
294	int	t_srtt;			/* smoothed round-trip time */
295	int	t_rttvar;		/* variance in round-trip time */
296
297	int	t_rxtshift;		/* log(2) of rexmt exp. backoff */
298	u_int	t_rttmin;		/* minimum rtt allowed */
299	u_int	t_rttbest;		/* best rtt we've seen */
300	u_int	t_rttcur;		/* most recent value of rtt */
301	u_int32_t	t_rttupdated;		/* number of times rtt sampled */
302	u_int32_t	t_rxt_conndroptime;	/* retxmt conn gets dropped after this time, when set */
303	u_int32_t	t_rxtstart;		/* time at which retransmission started */
304	u_int32_t	max_sndwnd;		/* largest window peer has offered */
305
306	int	t_softerror;		/* possible error not yet reported */
307/* out-of-band data */
308	char	t_oobflags;		/* have some */
309	char	t_iobc;			/* input character */
310#define	TCPOOB_HAVEDATA	0x01
311#define	TCPOOB_HADDATA	0x02
312/* RFC 1323 variables */
313	u_int8_t snd_scale;		/* window scaling for send window */
314	u_int8_t	rcv_scale;		/* window scaling for recv window */
315	u_int8_t	request_r_scale;	/* pending window scaling */
316	u_int8_t	requested_s_scale;
317	u_int8_t	tcp_cc_index;	/* index of congestion control algorithm */
318	u_int8_t	t_adaptive_rtimo;	/* Read timeout used as a multiple of RTT */
319	u_int8_t	t_adaptive_wtimo;	/* Write timeout used as a multiple of RTT */
320	u_int32_t	ts_recent;		/* timestamp echo data */
321
322	u_int32_t	ts_recent_age;		/* when last updated */
323	tcp_seq	last_ack_sent;
324/* RFC 1644 variables */
325	tcp_cc	cc_send;		/* send connection count */
326	tcp_cc	cc_recv;		/* receive connection count */
327/* RFC 3465 variables */
328	u_int32_t	t_bytes_acked;		/* ABC "bytes_acked" parameter */
329
330	int	t_lastchain;		/* amount of packets chained last time around */
331	u_int16_t	t_unacksegs;	/* received but unacked segments for delaying acks */
332	u_int8_t	t_rexmtthresh;	/* duplicate ack threshold for entering fast recovery */
333	u_int8_t	t_rtimo_probes; /* number of adaptive rtimo probes sent */
334	u_int32_t	t_persist_timeout;	/* ZWP persistence limit as set by PERSIST_TIMEOUT */
335	u_int32_t	t_persist_stop;		/* persistence limit deadline if triggered by ZWP */
336	u_int32_t	t_notsent_lowat;	/* Low water for not sent data */
337
338/* Receiver state for stretch-ack algorithm */
339	u_int32_t	rcv_unackwin;	/* to measure win for stretching acks */
340	u_int32_t	rcv_by_unackwin; /* bytes seen during the last ack-stretching win */
341	u_int16_t	rcv_waitforss;	/* wait for packets during slow-start */
342	u_int16_t		ecn_flags;
343#define TE_SETUPSENT		0x01	/* Indicate we have sent ECN-SETUP SYN or SYN-ACK */
344#define TE_SETUPRECEIVED	0x02	/* Indicate we have received ECN-SETUP SYN or SYN-ACK */
345#define TE_SENDIPECT		0x04	/* Indicate we haven't sent or received non-ECN-setup SYN or SYN-ACK */
346#define TE_SENDCWR		0x08	/* Indicate that the next non-retransmit should have the TCP CWR flag set */
347#define TE_SENDECE		0x10	/* Indicate that the next packet should have the TCP ECE flag set */
348#define TE_ECN_ON		(TE_SETUPSENT | TE_SETUPRECEIVED) /* Indicate ECN was successfully negotiated on a connection) */
349
350/* state for bad retransmit recovery */
351	u_int32_t	snd_cwnd_prev;	/* cwnd prior to retransmit */
352	u_int32_t	snd_ssthresh_prev;	/* ssthresh prior to retransmit */
353	tcp_seq	snd_recover_prev;	/* snd_recover prior to retransmit */
354	int	t_srtt_prev;		/* srtt prior to retransmit */
355	int	t_rttvar_prev;		/* rttvar prior to retransmit */
356	u_int32_t	t_badrexmt_time;	/* bad rexmt detection time */
357
358/* state to limit the number of early retransmits */
359	u_int32_t	t_early_rexmt_win; /* window for limiting early retransmits */
360	u_int16_t	t_early_rexmt_count; /* number of early rexmts seen in past window */
361
362/* SACK related state */
363	int16_t	snd_numholes;		/* number of holes seen by sender */
364	TAILQ_HEAD(sackhole_head, sackhole) snd_holes;
365						/* SACK scoreboard (sorted) */
366	tcp_seq	snd_fack;		/* last seq number(+1) sack'd by rcv'r*/
367	int	rcv_numsacks;		/* # distinct sack blks present */
368	struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
369	tcp_seq sack_newdata;		/* New data xmitted in this recovery
370   					   episode starts at this seq number */
371	struct sackhint	sackhint;	/* SACK scoreboard hint */
372
373	u_int32_t	t_pktlist_sentlen; /* total bytes in transmit chain */
374	struct mbuf	*t_pktlist_head; /* First packet in transmit chain */
375	struct mbuf	*t_pktlist_tail; /* Last packet in transmit chain */
376
377	u_int32_t	t_keepidle;	/* keepalive idle timer (override global if > 0) */
378	u_int32_t	t_keepinit;	/* connection timeout, i.e. idle time
379					in SYN_SENT or SYN_RECV state */
380	u_int32_t	t_keepintvl;	/* interval between keepalives */
381	u_int32_t	t_keepcnt;	/* number of keepalives before close */
382
383	u_int32_t	tso_max_segment_size;	/* TCP Segment Offloading maximum segment unit for NIC */
384	u_int 		t_pmtud_saved_maxopd;	/* MSS saved before performing PMTU-D BlackHole detection */
385
386	struct
387	{
388		u_int32_t	rxduplicatebytes;
389		u_int32_t	rxoutoforderbytes;
390		u_int32_t	txretransmitbytes;
391		u_int8_t	synrxtshift;
392		u_int8_t	unused;
393		u_int16_t	unused_pad_to_8;
394	} t_stat;
395
396	/* Background congestion related state */
397	uint32_t	rtt_hist[N_RTT_BASE];	/* history of minimum RTT */
398	uint32_t	rtt_count;		/* Number of RTT samples in recent base history */
399	uint32_t	bg_ssthresh;		/* Slow start threshold until delay increases */
400	uint32_t	t_flagsext;		/* Another field to accommodate more flags */
401#define TF_RXTFINDROP	0x1			/* Drop conn after retransmitting FIN 3 times */
402#define TF_RCVUNACK_WAITSS	0x2		/* set when the receiver should not stretch acks */
403#define TF_BWMEAS_INPROGRESS	0x4		/* Indicate BW meas is happening */
404#define TF_MEASURESNDBW		0x8		/* Measure send bw on this connection */
405#define TF_LRO_OFFLOADED	0x10		/* Connection LRO offloaded */
406#define TF_SACK_ENABLE		0x20		/* SACK is enabled */
407#define TF_RECOMPUTE_RTT	0x40		/* recompute RTT after spurious retransmit */
408#define TF_DETECT_READSTALL	0x80		/* Used to detect a stall during read operation */
409#define TF_RECV_THROTTLE	0x100		/* Input throttling active */
410#define	TF_NOSTRETCHACK		0x200		/* ack every other packet */
411#define	TF_STREAMEOW		0x400		/* Last packet was small indicating end of write */
412#if TRAFFIC_MGT
413	/* Inter-arrival jitter related state */
414	uint32_t 	iaj_rcv_ts;		/* tcp clock when the first packet was received */
415	uint16_t	iaj_size;		/* Size of packet for iaj measurement */
416	uint16_t	iaj_small_pkt;		/* Count of packets smaller than iaj_size */
417	uint16_t	iaj_pktcnt;		/* packet count, to avoid throttling initially */
418	uint16_t	acc_iaj;		/* Accumulated iaj */
419	tcp_seq 	iaj_rwintop;		/* recent max advertised window */
420	uint32_t	avg_iaj;		/* Mean */
421	uint32_t	std_dev_iaj;		/* Standard deviation */
422#endif /* TRAFFIC_MGT */
423	struct bwmeas	*t_bwmeas;		/* State for bandwidth measurement */
424	uint32_t	t_lropktlen;		/* Bytes in a LRO frame */
425	tcp_seq		t_idleat;		/* rcv_nxt at idle time */
426	TAILQ_ENTRY(tcpcb) t_twentry;		/* link for time wait queue */
427#if MPTCP
428	u_int32_t	t_mpflags;		/* flags for multipath TCP */
429
430#define TMPF_PREESTABLISHED 	0x00000001 /* conn in pre-established state */
431#define TMPF_SENT_KEYS		0x00000002 /* indicates that keys were sent */
432#define TMPF_MPTCP_TRUE		0x00000004 /* negotiated MPTCP successfully */
433#define TMPF_MPTCP_RCVD_KEY	0x00000008 /* state for 3-way handshake */
434#define TMPF_SND_MPPRIO		0x00000010 /* send priority of subflow */
435#define TMPF_SND_REM_ADDR	0x00000020 /* initiate address removal */
436#define TMPF_UNUSED		0x00000040 /* address addition acked by peer */
437#define TMPF_JOINED_FLOW	0x00000080 /* Indicates additional flow */
438#define TMPF_BACKUP_PATH	0x00000100 /* Indicates backup path */
439#define TMPF_MPTCP_ACKNOW	0x00000200 /* Send Data ACK */
440#define TMPF_SEND_DSN		0x00000400 /* Send DSN mapping */
441#define TMPF_SEND_DFIN		0x00000800 /* Send Data FIN */
442#define TMPF_RECV_DFIN		0x00001000 /* Recv Data FIN */
443#define TMPF_SENT_JOIN		0x00002000 /* Sent Join */
444#define TMPF_RECVD_JOIN		0x00004000 /* Received Join */
445#define TMPF_RESET		0x00008000 /* Send RST */
446#define TMPF_TCP_FALLBACK	0x00010000 /* Fallback to TCP */
447#define TMPF_FASTCLOSE		0x00020000 /* Send Fastclose option */
448#define TMPF_EMBED_DSN		0x00040000 /* tp has DSN mapping */
449#define TMPF_MPTCP_READY	0x00080000 /* Can send DSS options on data */
450#define TMPF_INFIN_SENT		0x00100000 /* Sent infinite mapping */
451#define TMPF_SND_MPFAIL		0x00200000 /* Received mapping csum failure */
452	void			*t_mptcb;	/* pointer to MPTCP TCB */
453	tcp_seq			t_mpuna;	/* unacknowledged sequence */
454	struct mpt_dsn_map	t_rcv_map;	/* Receive mapping list */
455	u_int8_t		t_local_aid;	/* Addr Id for authentication */
456	u_int8_t		t_rem_aid;	/* Addr ID of another subflow */
457	u_int8_t		t_mprxtshift;	/* join retransmission */
458#endif /* MPTCP */
459};
460
461#define IN_FASTRECOVERY(tp)	(tp->t_flags & TF_FASTRECOVERY)
462#define SACK_ENABLED(tp)	(tp->t_flagsext & TF_SACK_ENABLE)
463
464/*
465 * If the connection is in a throttled state due to advisory feedback from
466 * the interface output queue, reset that state. We do this in favor
467 * of entering recovery because the data transfer during recovery
468 * should be just a trickle and it will help to improve performance.
469 * We also do not want to back off twice in the same RTT.
470 */
471#define ENTER_FASTRECOVERY(_tp_) do {				\
472	(_tp_)->t_flags |= TF_FASTRECOVERY;			\
473	if (INP_IS_FLOW_CONTROLLED((_tp_)->t_inpcb))		\
474		inp_reset_fc_state((_tp_)->t_inpcb);		\
475} while(0)
476
477#define EXIT_FASTRECOVERY(_tp_) do {		\
478	(_tp_)->t_flags &= ~TF_FASTRECOVERY;	\
479	(_tp_)->t_dupacks = 0;			\
480	(_tp_)->t_rexmtthresh = tcprexmtthresh;	\
481	(_tp_)->t_bytes_acked = 0;		\
482} while(0)
483
484/*
485 * When the number of duplicate acks received is less than
486 * the retransmit threshold, use Limited Transmit algorithm
487 */
488extern int tcprexmtthresh;
489#define ALLOW_LIMITED_TRANSMIT(_tp_) \
490	((_tp_)->t_dupacks > 0 && \
491	(_tp_)->t_dupacks < (_tp_)->t_rexmtthresh)
492
493/*
494 * This condition is true is timestamp option is supported
495 * on a connection.
496 */
497#define TSTMP_SUPPORTED(_tp_) \
498	(((_tp_)->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP)) == \
499		(TF_REQ_TSTMP|TF_RCVD_TSTMP))
500
501/*
502 * Gives number of bytes acked by this ack
503 */
504#define BYTES_ACKED(_th_, _tp_) \
505	((_th_)->th_ack - (_tp_)->snd_una)
506
507#if CONFIG_DTRACE
508enum tcp_cc_event {
509	TCP_CC_CWND_INIT,
510	TCP_CC_INSEQ_ACK_RCVD,
511	TCP_CC_ACK_RCVD,
512	TCP_CC_ENTER_FASTRECOVERY,
513	TCP_CC_IN_FASTRECOVERY,
514	TCP_CC_EXIT_FASTRECOVERY,
515	TCP_CC_PARTIAL_ACK,
516	TCP_CC_IDLE_TIMEOUT,
517	TCP_CC_REXMT_TIMEOUT,
518	TCP_CC_ECN_RCVD,
519	TCP_CC_BAD_REXMT_RECOVERY,
520	TCP_CC_OUTPUT_ERROR,
521	TCP_CC_CHANGE_ALGO,
522	TCP_CC_FLOW_CONTROL,
523	TCP_CC_SUSPEND,
524	TCP_CC_LIMITED_TRANSMIT,
525	TCP_CC_EARLY_RETRANSMIT
526};
527#endif /* CONFIG_DTRACE */
528
529/*
530 * Structure to hold TCP options that are only used during segment
531 * processing (in tcp_input), but not held in the tcpcb.
532 * It's basically used to reduce the number of parameters
533 * to tcp_dooptions.
534 */
535struct tcpopt {
536	u_int32_t	to_flags;		/* which options are present */
537#define TOF_TS		0x0001		/* timestamp */
538#define	TOF_MSS		0x0010
539#define	TOF_SCALE	0x0020
540#define	TOF_SIGNATURE	0x0040	/* signature option present */
541#define	TOF_SIGLEN	0x0080	/* signature length valid (RFC2385) */
542#define	TOF_SACK	0x0100		/* Peer sent SACK option */
543#define	TOF_MPTCP	0x0200	/* MPTCP options to be dropped */
544	u_int32_t		to_tsval;
545	u_int32_t		to_tsecr;
546	u_int16_t	to_mss;
547	u_int8_t	to_requested_s_scale;
548	u_int8_t	to_nsacks;	/* number of SACK blocks */
549	u_char		*to_sacks;	/* pointer to the first SACK blocks */
550};
551
552/*
553 * The TAO cache entry which is stored in the protocol family specific
554 * portion of the route metrics.
555 */
556struct rmxp_tao {
557	tcp_cc	tao_cc;			/* latest CC in valid SYN */
558	tcp_cc	tao_ccsent;		/* latest CC sent to peer */
559	u_short	tao_mssopt;		/* peer's cached MSS */
560#ifdef notyet
561	u_short	tao_flags;		/* cache status flags */
562#define	TAOF_DONT	0x0001		/* peer doesn't understand rfc1644 */
563#define	TAOF_OK		0x0002		/* peer does understand rfc1644 */
564#define	TAOF_UNDEF	0		/* we don't know yet */
565#endif /* notyet */
566};
567#define rmx_taop(r)	((struct rmxp_tao *)(r).rmx_filler)
568
569#define	intotcpcb(ip)	((struct tcpcb *)(ip)->inp_ppcb)
570#define	sototcpcb(so)	(intotcpcb(sotoinpcb(so)))
571
572/*
573 * The rtt measured is in milliseconds as the timestamp granularity is
574 * a millisecond. The smoothed round-trip time and estimated variance
575 * are stored as fixed point numbers scaled by the values below.
576 * For convenience, these scales are also used in smoothing the average
577 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
578 * With these scales, srtt has 5 bits to the right of the binary point,
579 * and thus an "ALPHA" of 0.875.  rttvar has 4 bits to the right of the
580 * binary point, and is smoothed with an ALPHA of 0.75.
581 */
582#define	TCP_RTT_SCALE		32	/* multiplier for srtt; 3 bits frac. */
583#define	TCP_RTT_SHIFT		5	/* shift for srtt; 5 bits frac. */
584#define	TCP_RTTVAR_SCALE	16	/* multiplier for rttvar; 4 bits */
585#define	TCP_RTTVAR_SHIFT	4	/* shift for rttvar; 4 bits */
586#define	TCP_DELTA_SHIFT		2	/* see tcp_input.c */
587
588/*
589 * The initial retransmission should happen at rtt + 4 * rttvar.
590 * Because of the way we do the smoothing, srtt and rttvar
591 * will each average +1/2 tick of bias.  When we compute
592 * the retransmit timer, we want 1/2 tick of rounding and
593 * 1 extra tick because of +-1/2 tick uncertainty in the
594 * firing of the timer.  The bias will give us exactly the
595 * 1.5 tick we need.  But, because the bias is
596 * statistical, we have to test that we don't drop below
597 * the minimum feasible timer (which is 2 ticks).
598 * This version of the macro adapted from a paper by Lawrence
599 * Brakmo and Larry Peterson which outlines a problem caused
600 * by insufficient precision in the original implementation,
601 * which results in inappropriately large RTO values for very
602 * fast networks.
603 */
604#define	TCP_REXMTVAL(tp) \
605	max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
606	  + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
607
608/*
609 * Jaguar compatible TCP control block, for xtcpcb
610 * Does not have the old fields
611 */
612struct otcpcb {
613#else
614struct tseg_qent;
615_TCPCB_LIST_HEAD(tsegqe_head, tseg_qent);
616
617struct tcpcb {
618#endif /* KERNEL_PRIVATE */
619#if defined(KERNEL_PRIVATE)
620	u_int32_t t_segq;
621#else
622	struct	tsegqe_head t_segq;
623#endif /* KERNEL_PRIVATE */
624	int	t_dupacks;		/* consecutive dup acks recd */
625	u_int32_t unused;		/* unused now: was t_template */
626
627	int	t_timer[TCPT_NTIMERS_EXT];	/* tcp timers */
628
629	_TCPCB_PTR(struct inpcb *) t_inpcb;	/* back pointer to internet pcb */
630	int	t_state;		/* state of this connection */
631	u_int	t_flags;
632#define	TF_ACKNOW	0x00001		/* ack peer immediately */
633#define	TF_DELACK	0x00002		/* ack, but try to delay it */
634#define	TF_NODELAY	0x00004		/* don't delay packets to coalesce */
635#define	TF_NOOPT	0x00008		/* don't use tcp options */
636#define	TF_SENTFIN	0x00010		/* have sent FIN */
637#define	TF_REQ_SCALE	0x00020		/* have/will request window scaling */
638#define	TF_RCVD_SCALE	0x00040		/* other side has requested scaling */
639#define	TF_REQ_TSTMP	0x00080		/* have/will request timestamps */
640#define	TF_RCVD_TSTMP	0x00100		/* a timestamp was received in SYN */
641#define	TF_SACK_PERMIT	0x00200		/* other side said I could SACK */
642#define	TF_NEEDSYN	0x00400		/* send SYN (implicit state) */
643#define	TF_NEEDFIN	0x00800		/* send FIN (implicit state) */
644#define	TF_NOPUSH	0x01000		/* don't push */
645#define	TF_REQ_CC	0x02000		/* have/will request CC */
646#define	TF_RCVD_CC	0x04000		/* a CC was received in SYN */
647#define	TF_SENDCCNEW	0x08000		/* send CCnew instead of CC in SYN */
648#define	TF_MORETOCOME	0x10000		/* More data to be appended to sock */
649#define	TF_LQ_OVERFLOW	0x20000		/* listen queue overflow */
650#define	TF_RXWIN0SENT	0x40000		/* sent a receiver win 0 in response */
651#define	TF_SLOWLINK	0x80000		/* route is a on a modem speed link */
652
653	int	t_force;		/* 1 if forcing out a byte */
654
655	tcp_seq	snd_una;		/* send unacknowledged */
656	tcp_seq	snd_max;		/* highest sequence number sent;
657					 * used to recognize retransmits
658					 */
659	tcp_seq	snd_nxt;		/* send next */
660	tcp_seq	snd_up;			/* send urgent pointer */
661
662	tcp_seq	snd_wl1;		/* window update seg seq number */
663	tcp_seq	snd_wl2;		/* window update seg ack number */
664	tcp_seq	iss;			/* initial send sequence number */
665	tcp_seq	irs;			/* initial receive sequence number */
666
667	tcp_seq	rcv_nxt;		/* receive next */
668	tcp_seq	rcv_adv;		/* advertised window */
669	u_int32_t rcv_wnd;		/* receive window */
670	tcp_seq	rcv_up;			/* receive urgent pointer */
671
672	u_int32_t snd_wnd;		/* send window */
673	u_int32_t snd_cwnd;		/* congestion-controlled window */
674	u_int32_t snd_ssthresh;		/* snd_cwnd size threshold for
675					 * for slow start exponential to
676					 * linear switch
677					 */
678	u_int	t_maxopd;		/* mss plus options */
679
680	u_int32_t t_rcvtime;		/* time at which a packet was received */
681	u_int32_t t_starttime;		/* time connection was established */
682	int	t_rtttime;		/* round trip time */
683	tcp_seq	t_rtseq;		/* sequence number being timed */
684
685	int	t_rxtcur;		/* current retransmit value (ticks) */
686	u_int	t_maxseg;		/* maximum segment size */
687	int	t_srtt;			/* smoothed round-trip time */
688	int	t_rttvar;		/* variance in round-trip time */
689
690	int	t_rxtshift;		/* log(2) of rexmt exp. backoff */
691	u_int	t_rttmin;		/* minimum rtt allowed */
692	u_int32_t t_rttupdated;		/* number of times rtt sampled */
693	u_int32_t max_sndwnd;		/* largest window peer has offered */
694
695	int	t_softerror;		/* possible error not yet reported */
696/* out-of-band data */
697	char	t_oobflags;		/* have some */
698	char	t_iobc;			/* input character */
699#define	TCPOOB_HAVEDATA	0x01
700#define	TCPOOB_HADDATA	0x02
701/* RFC 1323 variables */
702	u_char	snd_scale;		/* window scaling for send window */
703	u_char	rcv_scale;		/* window scaling for recv window */
704	u_char	request_r_scale;	/* pending window scaling */
705	u_char	requested_s_scale;
706	u_int32_t ts_recent;		/* timestamp echo data */
707
708	u_int32_t ts_recent_age;	/* when last updated */
709	tcp_seq	last_ack_sent;
710/* RFC 1644 variables */
711	tcp_cc	cc_send;		/* send connection count */
712	tcp_cc	cc_recv;		/* receive connection count */
713	tcp_seq	snd_recover;		/* for use in fast recovery */
714/* experimental */
715	u_int32_t snd_cwnd_prev;	/* cwnd prior to retransmit */
716	u_int32_t snd_ssthresh_prev;	/* ssthresh prior to retransmit */
717	u_int32_t t_badrxtwin;		/* window for retransmit recovery */
718};
719
720
721/*
722 * TCP statistics.
723 * Many of these should be kept per connection,
724 * but that's inconvenient at the moment.
725 */
726struct	tcpstat {
727	u_int32_t	tcps_connattempt;	/* connections initiated */
728	u_int32_t	tcps_accepts;		/* connections accepted */
729	u_int32_t	tcps_connects;		/* connections established */
730	u_int32_t	tcps_drops;		/* connections dropped */
731	u_int32_t	tcps_conndrops;		/* embryonic connections dropped */
732	u_int32_t	tcps_closed;		/* conn. closed (includes drops) */
733	u_int32_t	tcps_segstimed;		/* segs where we tried to get rtt */
734	u_int32_t	tcps_rttupdated;	/* times we succeeded */
735	u_int32_t	tcps_delack;		/* delayed acks sent */
736	u_int32_t	tcps_timeoutdrop;	/* conn. dropped in rxmt timeout */
737	u_int32_t	tcps_rexmttimeo;	/* retransmit timeouts */
738	u_int32_t	tcps_persisttimeo;	/* persist timeouts */
739	u_int32_t	tcps_keeptimeo;		/* keepalive timeouts */
740	u_int32_t	tcps_keepprobe;		/* keepalive probes sent */
741	u_int32_t	tcps_keepdrops;		/* connections dropped in keepalive */
742
743	u_int32_t	tcps_sndtotal;		/* total packets sent */
744	u_int32_t	tcps_sndpack;		/* data packets sent */
745	u_int32_t	tcps_sndbyte;		/* data bytes sent */
746	u_int32_t	tcps_sndrexmitpack;	/* data packets retransmitted */
747	u_int32_t	tcps_sndrexmitbyte;	/* data bytes retransmitted */
748	u_int32_t	tcps_sndacks;		/* ack-only packets sent */
749	u_int32_t	tcps_sndprobe;		/* window probes sent */
750	u_int32_t	tcps_sndurg;		/* packets sent with URG only */
751	u_int32_t	tcps_sndwinup;		/* window update-only packets sent */
752	u_int32_t	tcps_sndctrl;		/* control (SYN|FIN|RST) packets sent */
753
754	u_int32_t	tcps_rcvtotal;		/* total packets received */
755	u_int32_t	tcps_rcvpack;		/* packets received in sequence */
756	u_int32_t	tcps_rcvbyte;		/* bytes received in sequence */
757	u_int32_t	tcps_rcvbadsum;		/* packets received with ccksum errs */
758	u_int32_t	tcps_rcvbadoff;		/* packets received with bad offset */
759	u_int32_t	tcps_rcvmemdrop;	/* packets dropped for lack of memory */
760	u_int32_t	tcps_rcvshort;		/* packets received too short */
761	u_int32_t	tcps_rcvduppack;	/* duplicate-only packets received */
762	u_int32_t	tcps_rcvdupbyte;	/* duplicate-only bytes received */
763	u_int32_t	tcps_rcvpartduppack;	/* packets with some duplicate data */
764	u_int32_t	tcps_rcvpartdupbyte;	/* dup. bytes in part-dup. packets */
765	u_int32_t	tcps_rcvoopack;		/* out-of-order packets received */
766	u_int32_t	tcps_rcvoobyte;		/* out-of-order bytes received */
767	u_int32_t	tcps_rcvpackafterwin;	/* packets with data after window */
768	u_int32_t	tcps_rcvbyteafterwin;	/* bytes rcvd after window */
769	u_int32_t	tcps_rcvafterclose;	/* packets rcvd after "close" */
770	u_int32_t	tcps_rcvwinprobe;	/* rcvd window probe packets */
771	u_int32_t	tcps_rcvdupack;		/* rcvd duplicate acks */
772	u_int32_t	tcps_rcvacktoomuch;	/* rcvd acks for unsent data */
773	u_int32_t	tcps_rcvackpack;	/* rcvd ack packets */
774	u_int32_t	tcps_rcvackbyte;	/* bytes acked by rcvd acks */
775	u_int32_t	tcps_rcvwinupd;		/* rcvd window update packets */
776	u_int32_t	tcps_pawsdrop;		/* segments dropped due to PAWS */
777	u_int32_t	tcps_predack;		/* times hdr predict ok for acks */
778	u_int32_t	tcps_preddat;		/* times hdr predict ok for data pkts */
779	u_int32_t	tcps_pcbcachemiss;
780	u_int32_t	tcps_cachedrtt;		/* times cached RTT in route updated */
781	u_int32_t	tcps_cachedrttvar;	/* times cached rttvar updated */
782	u_int32_t	tcps_cachedssthresh;	/* times cached ssthresh updated */
783	u_int32_t	tcps_usedrtt;		/* times RTT initialized from route */
784	u_int32_t	tcps_usedrttvar;	/* times RTTVAR initialized from rt */
785	u_int32_t	tcps_usedssthresh;	/* times ssthresh initialized from rt*/
786	u_int32_t	tcps_persistdrop;	/* timeout in persist state */
787	u_int32_t	tcps_badsyn;		/* bogus SYN, e.g. premature ACK */
788	u_int32_t	tcps_mturesent;		/* resends due to MTU discovery */
789	u_int32_t	tcps_listendrop;	/* listen queue overflows */
790
791	/* new stats from FreeBSD 5.4 sync up */
792	u_int32_t	tcps_minmssdrops;	/* average minmss too low drops */
793	u_int32_t	tcps_sndrexmitbad;	/* unnecessary packet retransmissions */
794	u_int32_t	tcps_badrst;		/* ignored RSTs in the window */
795
796	u_int32_t	tcps_sc_added;		/* entry added to syncache */
797	u_int32_t	tcps_sc_retransmitted;	/* syncache entry was retransmitted */
798	u_int32_t	tcps_sc_dupsyn;		/* duplicate SYN packet */
799	u_int32_t	tcps_sc_dropped;	/* could not reply to packet */
800	u_int32_t	tcps_sc_completed;	/* successful extraction of entry */
801	u_int32_t	tcps_sc_bucketoverflow;	/* syncache per-bucket limit hit */
802	u_int32_t	tcps_sc_cacheoverflow;	/* syncache cache limit hit */
803	u_int32_t	tcps_sc_reset;		/* RST removed entry from syncache */
804	u_int32_t	tcps_sc_stale;		/* timed out or listen socket gone */
805	u_int32_t	tcps_sc_aborted;	/* syncache entry aborted */
806	u_int32_t	tcps_sc_badack;		/* removed due to bad ACK */
807	u_int32_t	tcps_sc_unreach;	/* ICMP unreachable received */
808	u_int32_t	tcps_sc_zonefail;	/* zalloc() failed */
809	u_int32_t	tcps_sc_sendcookie;	/* SYN cookie sent */
810	u_int32_t	tcps_sc_recvcookie;	/* SYN cookie received */
811
812	u_int32_t	tcps_hc_added;		/* entry added to hostcache */
813	u_int32_t	tcps_hc_bucketoverflow;	/* hostcache per bucket limit hit */
814
815	/* SACK related stats */
816	u_int32_t	tcps_sack_recovery_episode; /* SACK recovery episodes */
817	u_int32_t 	tcps_sack_rexmits;	    /* SACK rexmit segments   */
818	u_int32_t 	tcps_sack_rexmit_bytes;	    /* SACK rexmit bytes      */
819	u_int32_t 	tcps_sack_rcv_blocks;	    /* SACK blocks (options) received */
820	u_int32_t 	tcps_sack_send_blocks;	    /* SACK blocks (options) sent     */
821	u_int32_t 	tcps_sack_sboverflow;	    /* SACK sendblock overflow   */
822
823	u_int32_t	tcps_bg_rcvtotal;	/* total background packets received */
824	u_int32_t	tcps_rxtfindrop;	/* drop conn after retransmitting FIN */
825	u_int32_t	tcps_fcholdpacket;	/* packets withheld because of flow control */
826
827	/* LRO related stats */
828	u_int32_t	tcps_coalesced_pack;	/* number of coalesced packets */
829	u_int32_t	tcps_flowtbl_full;	/* times flow table was full */
830	u_int32_t	tcps_flowtbl_collision;	/* collisions in flow tbl */
831	u_int32_t	tcps_lro_twopack;	/* 2 packets coalesced */
832	u_int32_t	tcps_lro_multpack;	/* 3 or 4 pkts coalesced */
833	u_int32_t	tcps_lro_largepack;	/* 5 or more pkts coalesced */
834
835	u_int32_t	tcps_limited_txt;	/* Limited transmit used */
836	u_int32_t	tcps_early_rexmt;	/* Early retransmit used */
837	u_int32_t	tcps_sack_ackadv;	/* Cumulative ack advanced along with sack */
838
839	/* Checksum related stats */
840	u_int32_t	tcps_rcv_swcsum;	/* tcp swcksum (inbound), packets */
841	u_int32_t	tcps_rcv_swcsum_bytes;	/* tcp swcksum (inbound), bytes */
842	u_int32_t	tcps_rcv6_swcsum;	/* tcp6 swcksum (inbound), packets */
843	u_int32_t	tcps_rcv6_swcsum_bytes;	/* tcp6 swcksum (inbound), bytes */
844	u_int32_t	tcps_snd_swcsum;	/* tcp swcksum (outbound), packets */
845	u_int32_t	tcps_snd_swcsum_bytes;	/* tcp swcksum (outbound), bytes */
846	u_int32_t	tcps_snd6_swcsum;	/* tcp6 swcksum (outbound), packets */
847	u_int32_t	tcps_snd6_swcsum_bytes;	/* tcp6 swcksum (outbound), bytes */
848	u_int32_t	tcps_msg_unopkts;	/* unordered packet on TCP msg stream */
849	u_int32_t	tcps_msg_unoappendfail; /* failed to append unordered pkt */
850	u_int32_t	tcps_msg_sndwaithipri; /* send is waiting for high priority data */
851
852	/* MPTCP Related stats */
853	u_int32_t	tcps_invalid_mpcap;	/* Invalid MPTCP capable opts */
854	u_int32_t	tcps_invalid_joins;	/* Invalid MPTCP joins */
855	u_int32_t	tcps_mpcap_fallback;	/* TCP fallback in primary */
856	u_int32_t	tcps_join_fallback;	/* No MPTCP in secondary */
857	u_int32_t	tcps_estab_fallback;	/* DSS option dropped */
858	u_int32_t	tcps_invalid_opt;	/* Catchall error stat */
859	u_int32_t	tcps_mp_outofwin;	/* Packet lies outside the
860						   shared recv window */
861	u_int32_t	tcps_mp_reducedwin;	/* Reduced subflow window */
862	u_int32_t	tcps_mp_badcsum;	/* Bad DSS csum */
863	u_int32_t	tcps_mp_oodata;		/* Out of order data */
864	u_int32_t	tcps_mp_switches;	/* number of subflow switch */
865	u_int32_t	tcps_mp_rcvtotal;	/* number of rcvd packets */
866	u_int32_t	tcps_mp_rcvbytes;	/* number of bytes received */
867	u_int32_t	tcps_mp_sndpacks;	/* number of data packs sent */
868	u_int32_t	tcps_mp_sndbytes;	/* number of bytes sent */
869	u_int32_t	tcps_join_rxmts;	/* join ack retransmits */
870};
871
872struct tcpstat_local {
873	u_int64_t badformat;
874	u_int64_t unspecv6;
875	u_int64_t synfin;
876	u_int64_t badformatipsec;
877	u_int64_t noconnnolist;
878	u_int64_t noconnlist;
879	u_int64_t listbadsyn;
880	u_int64_t icmp6unreach;
881	u_int64_t deprecate6;
882	u_int64_t ooopacket;
883	u_int64_t rstinsynrcv;
884	u_int64_t dospacket;
885	u_int64_t cleanup;
886	u_int64_t synwindow;
887};
888
889#pragma pack(4)
890
891/*
892 * TCB structure exported to user-land via sysctl(3).
893 * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
894 * included.  Not all of our clients do.
895 */
896
897struct  xtcpcb {
898        u_int32_t       xt_len;
899#ifdef KERNEL_PRIVATE
900        struct  inpcb_compat    xt_inp;
901#else
902        struct  inpcb   xt_inp;
903#endif
904#ifdef KERNEL_PRIVATE
905        struct  otcpcb  xt_tp;
906#else
907        struct  tcpcb   xt_tp;
908#endif
909        struct  xsocket xt_socket;
910        u_quad_t        xt_alignment_hack;
911};
912
913
914struct  xtcpcb64 {
915        u_int32_t      		xt_len;
916        struct xinpcb64		xt_inpcb;
917
918        u_int64_t t_segq;
919        int     t_dupacks;              /* consecutive dup acks recd */
920
921        int t_timer[TCPT_NTIMERS_EXT];  /* tcp timers */
922
923        int     t_state;                /* state of this connection */
924        u_int   t_flags;
925
926        int     t_force;                /* 1 if forcing out a byte */
927
928        tcp_seq snd_una;                /* send unacknowledged */
929        tcp_seq snd_max;                /* highest sequence number sent;
930                                         * used to recognize retransmits
931                                         */
932        tcp_seq snd_nxt;                /* send next */
933        tcp_seq snd_up;                 /* send urgent pointer */
934
935        tcp_seq snd_wl1;                /* window update seg seq number */
936        tcp_seq snd_wl2;                /* window update seg ack number */
937        tcp_seq iss;                    /* initial send sequence number */
938        tcp_seq irs;                    /* initial receive sequence number */
939
940        tcp_seq rcv_nxt;                /* receive next */
941        tcp_seq rcv_adv;                /* advertised window */
942        u_int32_t rcv_wnd;              /* receive window */
943        tcp_seq rcv_up;                 /* receive urgent pointer */
944
945        u_int32_t snd_wnd;              /* send window */
946        u_int32_t snd_cwnd;             /* congestion-controlled window */
947        u_int32_t snd_ssthresh;         /* snd_cwnd size threshold for
948                                         * for slow start exponential to
949                                         * linear switch
950                                         */
951        u_int   t_maxopd;               /* mss plus options */
952
953        u_int32_t t_rcvtime;            /* time at which a packet was received */
954        u_int32_t t_starttime;          /* time connection was established */
955        int     t_rtttime;              /* round trip time */
956        tcp_seq t_rtseq;                /* sequence number being timed */
957
958        int     t_rxtcur;               /* current retransmit value (ticks) */
959        u_int   t_maxseg;               /* maximum segment size */
960        int     t_srtt;                 /* smoothed round-trip time */
961        int     t_rttvar;               /* variance in round-trip time */
962
963        int     t_rxtshift;             /* log(2) of rexmt exp. backoff */
964        u_int   t_rttmin;               /* minimum rtt allowed */
965        u_int32_t t_rttupdated;         /* number of times rtt sampled */
966        u_int32_t max_sndwnd;           /* largest window peer has offered */
967
968        int     t_softerror;            /* possible error not yet reported */
969/* out-of-band data */
970        char    t_oobflags;             /* have some */
971        char    t_iobc;                 /* input character */
972/* RFC 1323 variables */
973        u_char  snd_scale;              /* window scaling for send window */
974        u_char  rcv_scale;              /* window scaling for recv window */
975        u_char  request_r_scale;        /* pending window scaling */
976        u_char  requested_s_scale;
977        u_int32_t ts_recent;            /* timestamp echo data */
978
979        u_int32_t ts_recent_age;        /* when last updated */
980        tcp_seq last_ack_sent;
981/* RFC 1644 variables */
982        tcp_cc  cc_send;                /* send connection count */
983        tcp_cc  cc_recv;                /* receive connection count */
984        tcp_seq snd_recover;            /* for use in fast recovery */
985/* experimental */
986        u_int32_t snd_cwnd_prev;        /* cwnd prior to retransmit */
987        u_int32_t snd_ssthresh_prev;    /* ssthresh prior to retransmit */
988        u_int32_t t_badrxtwin;          /* window for retransmit recovery */
989
990        u_quad_t		xt_alignment_hack;
991};
992
993
994#ifdef PRIVATE
995
996struct  xtcpcb_n {
997	u_int32_t      		xt_len;
998	u_int32_t			xt_kind;		/* XSO_TCPCB */
999
1000	u_int64_t t_segq;
1001	int     t_dupacks;              /* consecutive dup acks recd */
1002
1003	int t_timer[TCPT_NTIMERS_EXT];  /* tcp timers */
1004
1005	int     t_state;                /* state of this connection */
1006	u_int   t_flags;
1007
1008	int     t_force;                /* 1 if forcing out a byte */
1009
1010	tcp_seq snd_una;                /* send unacknowledged */
1011	tcp_seq snd_max;                /* highest sequence number sent;
1012									 * used to recognize retransmits
1013									 */
1014	tcp_seq snd_nxt;                /* send next */
1015	tcp_seq snd_up;                 /* send urgent pointer */
1016
1017	tcp_seq snd_wl1;                /* window update seg seq number */
1018	tcp_seq snd_wl2;                /* window update seg ack number */
1019	tcp_seq iss;                    /* initial send sequence number */
1020	tcp_seq irs;                    /* initial receive sequence number */
1021
1022	tcp_seq rcv_nxt;                /* receive next */
1023	tcp_seq rcv_adv;                /* advertised window */
1024	u_int32_t rcv_wnd;              /* receive window */
1025	tcp_seq rcv_up;                 /* receive urgent pointer */
1026
1027	u_int32_t snd_wnd;              /* send window */
1028	u_int32_t snd_cwnd;             /* congestion-controlled window */
1029	u_int32_t snd_ssthresh;         /* snd_cwnd size threshold for
1030									 * for slow start exponential to
1031									 * linear switch
1032									 */
1033	u_int   t_maxopd;               /* mss plus options */
1034
1035	u_int32_t t_rcvtime;            /* time at which a packet was received */
1036	u_int32_t t_starttime;          /* time connection was established */
1037	int     t_rtttime;              /* round trip time */
1038	tcp_seq t_rtseq;                /* sequence number being timed */
1039
1040	int     t_rxtcur;               /* current retransmit value (ticks) */
1041	u_int   t_maxseg;               /* maximum segment size */
1042	int     t_srtt;                 /* smoothed round-trip time */
1043	int     t_rttvar;               /* variance in round-trip time */
1044
1045	int     t_rxtshift;             /* log(2) of rexmt exp. backoff */
1046	u_int   t_rttmin;               /* minimum rtt allowed */
1047	u_int32_t t_rttupdated;         /* number of times rtt sampled */
1048	u_int32_t max_sndwnd;           /* largest window peer has offered */
1049
1050	int     t_softerror;            /* possible error not yet reported */
1051	/* out-of-band data */
1052	char    t_oobflags;             /* have some */
1053	char    t_iobc;                 /* input character */
1054	/* RFC 1323 variables */
1055	u_char  snd_scale;              /* window scaling for send window */
1056	u_char  rcv_scale;              /* window scaling for recv window */
1057	u_char  request_r_scale;        /* pending window scaling */
1058	u_char  requested_s_scale;
1059	u_int32_t ts_recent;            /* timestamp echo data */
1060
1061	u_int32_t ts_recent_age;        /* when last updated */
1062	tcp_seq last_ack_sent;
1063	/* RFC 1644 variables */
1064	tcp_cc  cc_send;                /* send connection count */
1065	tcp_cc  cc_recv;                /* receive connection count */
1066	tcp_seq snd_recover;            /* for use in fast recovery */
1067	/* experimental */
1068	u_int32_t snd_cwnd_prev;        /* cwnd prior to retransmit */
1069	u_int32_t snd_ssthresh_prev;    /* ssthresh prior to retransmit */
1070};
1071
1072#endif /* PRIVATE */
1073
1074#pragma pack()
1075
1076/*
1077 * Names for TCP sysctl objects
1078 */
1079#define	TCPCTL_DO_RFC1323	1	/* use RFC-1323 extensions */
1080#define	TCPCTL_DO_RFC1644	2	/* use RFC-1644 extensions */
1081#define	TCPCTL_MSSDFLT		3	/* MSS default */
1082#define TCPCTL_STATS		4	/* statistics (read-only) */
1083#define	TCPCTL_RTTDFLT		5	/* default RTT estimate */
1084#define	TCPCTL_KEEPIDLE		6	/* keepalive idle timer */
1085#define	TCPCTL_KEEPINTVL	7	/* interval to send keepalives */
1086#define	TCPCTL_SENDSPACE	8	/* send buffer space */
1087#define	TCPCTL_RECVSPACE	9	/* receive buffer space */
1088#define	TCPCTL_KEEPINIT		10	/* timeout for establishing syn */
1089#define	TCPCTL_PCBLIST		11	/* list of all outstanding PCBs */
1090#define	TCPCTL_DELACKTIME	12	/* time before sending delayed ACK */
1091#define	TCPCTL_V6MSSDFLT	13	/* MSS default for IPv6 */
1092#define	TCPCTL_MAXID		14
1093
1094#ifdef BSD_KERNEL_PRIVATE
1095#include <sys/bitstring.h>
1096
1097#define	TCP_PKTLIST_CLEAR(tp) {						\
1098	(tp)->t_pktlist_head = (tp)->t_pktlist_tail = NULL;		\
1099	(tp)->t_lastchain = (tp)->t_pktlist_sentlen = 0;		\
1100}
1101
1102#define TCPCTL_NAMES { \
1103	{ 0, 0 }, \
1104	{ "rfc1323", CTLTYPE_INT }, \
1105	{ "rfc1644", CTLTYPE_INT }, \
1106	{ "mssdflt", CTLTYPE_INT }, \
1107	{ "stats", CTLTYPE_STRUCT }, \
1108	{ "rttdflt", CTLTYPE_INT }, \
1109	{ "keepidle", CTLTYPE_INT }, \
1110	{ "keepintvl", CTLTYPE_INT }, \
1111	{ "sendspace", CTLTYPE_INT }, \
1112	{ "recvspace", CTLTYPE_INT }, \
1113	{ "keepinit", CTLTYPE_INT }, \
1114	{ "pcblist", CTLTYPE_STRUCT }, \
1115	{ "delacktime", CTLTYPE_INT }, \
1116	{ "v6mssdflt", CTLTYPE_INT }, \
1117}
1118
1119#ifdef SYSCTL_DECL
1120SYSCTL_DECL(_net_inet_tcp);
1121#endif /* SYSCTL_DECL */
1122
1123/*
1124 * Flags for TCP's connectx(2) user-protocol request routine.
1125 */
1126#if MPTCP
1127#define	TCP_CONNREQF_MPTCP	0x1	/* called internally by MPTCP */
1128#endif /* MPTCP */
1129
1130extern	struct inpcbhead tcb;		/* head of queue of active tcpcb's */
1131extern	struct inpcbinfo tcbinfo;
1132extern	struct tcpstat tcpstat;	/* tcp statistics */
1133extern	int tcp_mssdflt;	/* XXX */
1134extern	int tcp_minmss;
1135extern	int ss_fltsz;
1136extern	int ss_fltsz_local;
1137extern 	int tcp_do_rfc3390;		/* Calculate ss_fltsz according to RFC 3390 */
1138extern int target_qdelay;
1139#ifdef __APPLE__
1140extern	u_int32_t tcp_now;		/* for RFC 1323 timestamps */
1141extern struct timeval tcp_uptime;
1142extern lck_spin_t *tcp_uptime_lock;
1143
1144extern	int tcp_delack_enabled;
1145#endif /* __APPLE__ */
1146
1147extern	int tcp_do_sack;	/* SACK enabled/disabled */
1148
1149#if CONFIG_IFEF_NOWINDOWSCALE
1150extern int tcp_obey_ifef_nowindowscale;
1151#endif
1152
1153struct protosw;
1154struct domain;
1155
1156void	 tcp_canceltimers(struct tcpcb *);
1157struct tcpcb *
1158	 tcp_close(struct tcpcb *);
1159void	 tcp_ctlinput(int, struct sockaddr *, void *);
1160int	 tcp_ctloutput(struct socket *, struct sockopt *);
1161struct tcpcb *
1162	 tcp_drop(struct tcpcb *, int);
1163void	 tcp_drain(void);
1164void	 tcp_getrt_rtt(struct tcpcb *tp, struct rtentry *rt);
1165struct rmxp_tao *
1166	 tcp_gettaocache(struct inpcb *);
1167void	 tcp_init(struct protosw *, struct domain *);
1168void	 tcp_input(struct mbuf *, int);
1169void	 tcp_mss(struct tcpcb *, int, unsigned int);
1170int	 tcp_mssopt(struct tcpcb *);
1171void	 tcp_drop_syn_sent(struct inpcb *, int);
1172void	 tcp_mtudisc(struct inpcb *, int);
1173struct tcpcb *
1174	 tcp_newtcpcb(struct inpcb *);
1175int	 tcp_output(struct tcpcb *);
1176void	 tcp_respond(struct tcpcb *, void *,
1177	    struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int,
1178	    unsigned int, unsigned int);
1179struct rtentry *tcp_rtlookup(struct inpcb *, unsigned int);
1180void	 tcp_setpersist(struct tcpcb *);
1181void	tcp_gc(struct inpcbinfo *);
1182void 	 tcp_check_timer_state(struct tcpcb *tp);
1183void	 tcp_run_timerlist(void *arg1, void *arg2);
1184
1185struct tcptemp *
1186	 tcp_maketemplate(struct tcpcb *);
1187void	 tcp_fillheaders(struct tcpcb *, void *, void *);
1188struct tcpcb *
1189	 tcp_timers(struct tcpcb *, int);
1190void	 tcp_trace(int, int, struct tcpcb *, void *, struct tcphdr *, int);
1191
1192void tcp_sack_doack(struct tcpcb *, struct tcpopt *, tcp_seq, u_int32_t *);
1193void	 tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend);
1194void	 tcp_clean_sackreport(struct tcpcb *tp);
1195void	 tcp_sack_adjust(struct tcpcb *tp);
1196struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt);
1197void	 tcp_sack_partialack(struct tcpcb *, struct tcphdr *);
1198void	 tcp_free_sackholes(struct tcpcb *tp);
1199int32_t	 tcp_sbspace(struct tcpcb *tp);
1200void	 tcp_set_tso(struct tcpcb *tp, struct ifnet *ifp);
1201void	 tcp_reset_stretch_ack(struct tcpcb *tp);
1202extern void tcp_get_ports_used(u_int32_t, int, u_int32_t, bitstr_t *);
1203uint32_t tcp_count_opportunistic(unsigned int ifindex, u_int32_t flags);
1204uint32_t tcp_find_anypcb_byaddr(struct ifaddr *ifa);
1205void	 tcp_set_max_rwinscale(struct tcpcb *tp, struct socket *so);
1206struct bwmeas* tcp_bwmeas_alloc(struct tcpcb *tp);
1207void tcp_bwmeas_free(struct tcpcb *tp);
1208
1209extern void tcp_set_background_cc(struct socket *);
1210extern void tcp_set_foreground_cc(struct socket *);
1211extern void tcp_set_recv_bg(struct socket *);
1212extern void tcp_clear_recv_bg(struct socket *);
1213#define	IS_TCP_RECV_BG(_so)	\
1214	((_so)->so_traffic_mgt_flags & TRAFFIC_MGT_TCP_RECVBG)
1215
1216#if TRAFFIC_MGT
1217#define CLEAR_IAJ_STATE(_tp_) (_tp_)->iaj_rcv_ts = 0
1218void	 reset_acc_iaj(struct tcpcb *tp);
1219#endif /* TRAFFIC_MGT */
1220
1221int	 tcp_lock (struct socket *, int, void *);
1222int	 tcp_unlock (struct socket *, int, void *);
1223void	 calculate_tcp_clock(void);
1224
1225extern void mptcp_insert_rmap(struct tcpcb *, struct mbuf *);
1226extern void tcp_keepalive_reset(struct tcpcb *);
1227
1228#ifdef _KERN_LOCKS_H_
1229lck_mtx_t *	 tcp_getlock (struct socket *, int);
1230#else
1231void *	 tcp_getlock (struct socket *, int);
1232#endif
1233
1234
1235extern	struct pr_usrreqs tcp_usrreqs;
1236extern	u_int32_t tcp_sendspace;
1237extern	u_int32_t tcp_recvspace;
1238tcp_seq tcp_new_isn(struct tcpcb *);
1239
1240extern int tcp_input_checksum(int, struct mbuf *, struct tcphdr *, int, int);
1241extern void tcp_getconninfo(struct socket *, struct conninfo_tcp *);
1242#if MPTCP
1243extern uint16_t mptcp_input_csum(struct tcpcb *, struct mbuf *, int);
1244extern void mptcp_output_csum(struct tcpcb *, struct mbuf *, int32_t, unsigned,
1245    u_int64_t, u_int32_t *);
1246extern int mptcp_adj_mss(struct tcpcb *, boolean_t);
1247#endif
1248#endif /* BSD_KERNEL_RPIVATE */
1249
1250#endif /* _NETINET_TCP_VAR_H_ */
1251