1/*	$OpenBSD: tcp_usrreq.c,v 1.231 2024/04/12 16:07:09 bluhm Exp $	*/
2/*	$NetBSD: tcp_usrreq.c,v 1.20 1996/02/13 23:44:16 christos Exp $	*/
3
4/*
5 * Copyright (c) 1982, 1986, 1988, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
33 *
34 * NRL grants permission for redistribution and use in source and binary
35 * forms, with or without modification, of the software and documentation
36 * created at NRL provided that the following conditions are met:
37 *
38 * 1. Redistributions of source code must retain the above copyright
39 *    notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 *    notice, this list of conditions and the following disclaimer in the
42 *    documentation and/or other materials provided with the distribution.
43 * 3. All advertising materials mentioning features or use of this software
44 *    must display the following acknowledgements:
45 *	This product includes software developed by the University of
46 *	California, Berkeley and its contributors.
47 *	This product includes software developed at the Information
48 *	Technology Division, US Naval Research Laboratory.
49 * 4. Neither the name of the NRL nor the names of its contributors
50 *    may be used to endorse or promote products derived from this software
51 *    without specific prior written permission.
52 *
53 * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
54 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
55 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
56 * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
57 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
58 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
59 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
60 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
61 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
62 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
63 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64 *
65 * The views and conclusions contained in the software and documentation
66 * are those of the authors and should not be interpreted as representing
67 * official policies, either expressed or implied, of the US Naval
68 * Research Laboratory (NRL).
69 */
70
71#include <sys/param.h>
72#include <sys/systm.h>
73#include <sys/mbuf.h>
74#include <sys/socket.h>
75#include <sys/socketvar.h>
76#include <sys/protosw.h>
77#include <sys/stat.h>
78#include <sys/sysctl.h>
79#include <sys/domain.h>
80#include <sys/kernel.h>
81#include <sys/pool.h>
82#include <sys/proc.h>
83
84#include <net/if.h>
85#include <net/if_var.h>
86#include <net/route.h>
87
88#include <netinet/in.h>
89#include <netinet/in_var.h>
90#include <netinet/ip.h>
91#include <netinet/in_pcb.h>
92#include <netinet/ip_var.h>
93#include <netinet6/ip6_var.h>
94#include <netinet/tcp.h>
95#include <netinet/tcp_fsm.h>
96#include <netinet/tcp_seq.h>
97#include <netinet/tcp_timer.h>
98#include <netinet/tcp_var.h>
99#include <netinet/tcp_debug.h>
100
101#ifdef INET6
102#include <netinet6/in6_var.h>
103#endif
104
105#ifndef TCP_SENDSPACE
106#define	TCP_SENDSPACE	1024*16
107#endif
108u_int	tcp_sendspace = TCP_SENDSPACE;
109#ifndef TCP_RECVSPACE
110#define	TCP_RECVSPACE	1024*16
111#endif
112u_int	tcp_recvspace = TCP_RECVSPACE;
113u_int	tcp_autorcvbuf_inc = 16 * 1024;
114
115const struct pr_usrreqs tcp_usrreqs = {
116	.pru_attach	= tcp_attach,
117	.pru_detach	= tcp_detach,
118	.pru_bind	= tcp_bind,
119	.pru_listen	= tcp_listen,
120	.pru_connect	= tcp_connect,
121	.pru_accept	= tcp_accept,
122	.pru_disconnect	= tcp_disconnect,
123	.pru_shutdown	= tcp_shutdown,
124	.pru_rcvd	= tcp_rcvd,
125	.pru_send	= tcp_send,
126	.pru_abort	= tcp_abort,
127	.pru_sense	= tcp_sense,
128	.pru_rcvoob	= tcp_rcvoob,
129	.pru_sendoob	= tcp_sendoob,
130	.pru_control	= in_control,
131	.pru_sockaddr	= tcp_sockaddr,
132	.pru_peeraddr	= tcp_peeraddr,
133};
134
135#ifdef INET6
136const struct pr_usrreqs tcp6_usrreqs = {
137	.pru_attach	= tcp_attach,
138	.pru_detach	= tcp_detach,
139	.pru_bind	= tcp_bind,
140	.pru_listen	= tcp_listen,
141	.pru_connect	= tcp_connect,
142	.pru_accept	= tcp_accept,
143	.pru_disconnect	= tcp_disconnect,
144	.pru_shutdown	= tcp_shutdown,
145	.pru_rcvd	= tcp_rcvd,
146	.pru_send	= tcp_send,
147	.pru_abort	= tcp_abort,
148	.pru_sense	= tcp_sense,
149	.pru_rcvoob	= tcp_rcvoob,
150	.pru_sendoob	= tcp_sendoob,
151	.pru_control	= in6_control,
152	.pru_sockaddr	= tcp_sockaddr,
153	.pru_peeraddr	= tcp_peeraddr,
154};
155#endif
156
157const struct sysctl_bounded_args tcpctl_vars[] = {
158	{ TCPCTL_RFC1323, &tcp_do_rfc1323, 0, 1 },
159	{ TCPCTL_SACK, &tcp_do_sack, 0, 1 },
160	{ TCPCTL_MSSDFLT, &tcp_mssdflt, TCP_MSS, 65535 },
161	{ TCPCTL_RSTPPSLIMIT, &tcp_rst_ppslim, 1, 1000 * 1000 },
162	{ TCPCTL_ACK_ON_PUSH, &tcp_ack_on_push, 0, 1 },
163#ifdef TCP_ECN
164	{ TCPCTL_ECN, &tcp_do_ecn, 0, 1 },
165#endif
166	{ TCPCTL_SYN_CACHE_LIMIT, &tcp_syn_cache_limit, 1, 1000 * 1000 },
167	{ TCPCTL_SYN_BUCKET_LIMIT, &tcp_syn_bucket_limit, 1, INT_MAX },
168	{ TCPCTL_RFC3390, &tcp_do_rfc3390, 0, 2 },
169	{ TCPCTL_ALWAYS_KEEPALIVE, &tcp_always_keepalive, 0, 1 },
170	{ TCPCTL_TSO, &tcp_do_tso, 0, 1 },
171};
172
173struct	inpcbtable tcbtable;
174#ifdef INET6
175struct	inpcbtable tcb6table;
176#endif
177
178int	tcp_fill_info(struct tcpcb *, struct socket *, struct mbuf *);
179int	tcp_ident(void *, size_t *, void *, size_t, int);
180
181static inline int tcp_sogetpcb(struct socket *, struct inpcb **,
182		    struct tcpcb **);
183
184static inline int
185tcp_sogetpcb(struct socket *so, struct inpcb **rinp, struct tcpcb **rtp)
186{
187	struct inpcb *inp;
188	struct tcpcb *tp;
189
190	/*
191	 * When a TCP is attached to a socket, then there will be
192	 * a (struct inpcb) pointed at by the socket, and this
193	 * structure will point at a subsidiary (struct tcpcb).
194	 */
195	if ((inp = sotoinpcb(so)) == NULL || (tp = intotcpcb(inp)) == NULL) {
196		if (so->so_error)
197			return so->so_error;
198		return EINVAL;
199	}
200
201	*rinp = inp;
202	*rtp = tp;
203
204	return 0;
205}
206
207/*
208 * Export internal TCP state information via a struct tcp_info without
209 * leaking any sensitive information. Sequence numbers are reported
210 * relative to the initial sequence number.
211 */
212int
213tcp_fill_info(struct tcpcb *tp, struct socket *so, struct mbuf *m)
214{
215	struct proc *p = curproc;
216	struct tcp_info *ti;
217	u_int t = 1000;		/* msec => usec */
218	uint64_t now;
219
220	if (sizeof(*ti) > MLEN) {
221		MCLGETL(m, M_WAITOK, sizeof(*ti));
222		if (!ISSET(m->m_flags, M_EXT))
223			return ENOMEM;
224	}
225	ti = mtod(m, struct tcp_info *);
226	m->m_len = sizeof(*ti);
227	memset(ti, 0, sizeof(*ti));
228	now = tcp_now();
229
230	ti->tcpi_state = tp->t_state;
231	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
232		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
233	if (tp->t_flags & TF_SACK_PERMIT)
234		ti->tcpi_options |= TCPI_OPT_SACK;
235	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
236		ti->tcpi_options |= TCPI_OPT_WSCALE;
237		ti->tcpi_snd_wscale = tp->snd_scale;
238		ti->tcpi_rcv_wscale = tp->rcv_scale;
239	}
240#ifdef TCP_ECN
241	if (tp->t_flags & TF_ECN_PERMIT)
242		ti->tcpi_options |= TCPI_OPT_ECN;
243#endif
244
245	ti->tcpi_rto = tp->t_rxtcur * t;
246	ti->tcpi_snd_mss = tp->t_maxseg;
247	ti->tcpi_rcv_mss = tp->t_peermss;
248
249	ti->tcpi_last_data_sent = (now - tp->t_sndtime) * t;
250	ti->tcpi_last_ack_sent = (now - tp->t_sndacktime) * t;
251	ti->tcpi_last_data_recv = (now - tp->t_rcvtime) * t;
252	ti->tcpi_last_ack_recv = (now - tp->t_rcvacktime) * t;
253
254	ti->tcpi_rtt = ((uint64_t)tp->t_srtt * t) >>
255	    (TCP_RTT_SHIFT + TCP_RTT_BASE_SHIFT);
256	ti->tcpi_rttvar = ((uint64_t)tp->t_rttvar * t) >>
257	    (TCP_RTTVAR_SHIFT + TCP_RTT_BASE_SHIFT);
258	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
259	ti->tcpi_snd_cwnd = tp->snd_cwnd;
260
261	ti->tcpi_rcv_space = tp->rcv_wnd;
262
263	/*
264	 * Provide only minimal information for unprivileged processes.
265	 */
266	if (suser(p) != 0)
267		return 0;
268
269	/* FreeBSD-specific extension fields for tcp_info.  */
270	ti->tcpi_snd_wnd = tp->snd_wnd;
271	ti->tcpi_snd_nxt = tp->snd_nxt - tp->iss;
272	ti->tcpi_rcv_nxt = tp->rcv_nxt - tp->irs;
273	/* missing tcpi_toe_tid */
274	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
275	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
276	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
277
278	/* OpenBSD extensions */
279	ti->tcpi_rttmin = tp->t_rttmin * t;
280	ti->tcpi_max_sndwnd = tp->max_sndwnd;
281	ti->tcpi_rcv_adv = tp->rcv_adv - tp->irs;
282	ti->tcpi_rcv_up = tp->rcv_up - tp->irs;
283	ti->tcpi_snd_una = tp->snd_una - tp->iss;
284	ti->tcpi_snd_up = tp->snd_up - tp->iss;
285	ti->tcpi_snd_wl1 = tp->snd_wl1 - tp->iss;
286	ti->tcpi_snd_wl2 = tp->snd_wl2 - tp->iss;
287	ti->tcpi_snd_max = tp->snd_max - tp->iss;
288
289	ti->tcpi_ts_recent = tp->ts_recent; /* XXX value from the wire */
290	ti->tcpi_ts_recent_age = (now - tp->ts_recent_age) * t;
291	ti->tcpi_rfbuf_cnt = tp->rfbuf_cnt;
292	ti->tcpi_rfbuf_ts = (now - tp->rfbuf_ts) * t;
293
294	ti->tcpi_so_rcv_sb_cc = so->so_rcv.sb_cc;
295	ti->tcpi_so_rcv_sb_hiwat = so->so_rcv.sb_hiwat;
296	ti->tcpi_so_rcv_sb_lowat = so->so_rcv.sb_lowat;
297	ti->tcpi_so_rcv_sb_wat = so->so_rcv.sb_wat;
298	ti->tcpi_so_snd_sb_cc = so->so_snd.sb_cc;
299	ti->tcpi_so_snd_sb_hiwat = so->so_snd.sb_hiwat;
300	ti->tcpi_so_snd_sb_lowat = so->so_snd.sb_lowat;
301	ti->tcpi_so_snd_sb_wat = so->so_snd.sb_wat;
302
303	return 0;
304}
305
306int
307tcp_ctloutput(int op, struct socket *so, int level, int optname,
308    struct mbuf *m)
309{
310	int error = 0;
311	struct inpcb *inp;
312	struct tcpcb *tp;
313	int i;
314
315	inp = sotoinpcb(so);
316	if (inp == NULL)
317		return (ECONNRESET);
318	if (level != IPPROTO_TCP) {
319#ifdef INET6
320		if (ISSET(inp->inp_flags, INP_IPV6))
321			error = ip6_ctloutput(op, so, level, optname, m);
322		else
323#endif
324			error = ip_ctloutput(op, so, level, optname, m);
325		return (error);
326	}
327	tp = intotcpcb(inp);
328
329	switch (op) {
330
331	case PRCO_SETOPT:
332		switch (optname) {
333
334		case TCP_NODELAY:
335			if (m == NULL || m->m_len < sizeof (int))
336				error = EINVAL;
337			else if (*mtod(m, int *))
338				tp->t_flags |= TF_NODELAY;
339			else
340				tp->t_flags &= ~TF_NODELAY;
341			break;
342
343		case TCP_NOPUSH:
344			if (m == NULL || m->m_len < sizeof (int))
345				error = EINVAL;
346			else if (*mtod(m, int *))
347				tp->t_flags |= TF_NOPUSH;
348			else if (tp->t_flags & TF_NOPUSH) {
349				tp->t_flags &= ~TF_NOPUSH;
350				if (TCPS_HAVEESTABLISHED(tp->t_state))
351					error = tcp_output(tp);
352			}
353			break;
354
355		case TCP_MAXSEG:
356			if (m == NULL || m->m_len < sizeof (int)) {
357				error = EINVAL;
358				break;
359			}
360
361			i = *mtod(m, int *);
362			if (i > 0 && i <= tp->t_maxseg)
363				tp->t_maxseg = i;
364			else
365				error = EINVAL;
366			break;
367
368		case TCP_SACK_ENABLE:
369			if (m == NULL || m->m_len < sizeof (int)) {
370				error = EINVAL;
371				break;
372			}
373
374			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
375				error = EPERM;
376				break;
377			}
378
379			if (tp->t_flags & TF_SIGNATURE) {
380				error = EPERM;
381				break;
382			}
383
384			if (*mtod(m, int *))
385				tp->sack_enable = 1;
386			else
387				tp->sack_enable = 0;
388			break;
389#ifdef TCP_SIGNATURE
390		case TCP_MD5SIG:
391			if (m == NULL || m->m_len < sizeof (int)) {
392				error = EINVAL;
393				break;
394			}
395
396			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
397				error = EPERM;
398				break;
399			}
400
401			if (*mtod(m, int *)) {
402				tp->t_flags |= TF_SIGNATURE;
403				tp->sack_enable = 0;
404			} else
405				tp->t_flags &= ~TF_SIGNATURE;
406			break;
407#endif /* TCP_SIGNATURE */
408		default:
409			error = ENOPROTOOPT;
410			break;
411		}
412		break;
413
414	case PRCO_GETOPT:
415		switch (optname) {
416		case TCP_NODELAY:
417			m->m_len = sizeof(int);
418			*mtod(m, int *) = tp->t_flags & TF_NODELAY;
419			break;
420		case TCP_NOPUSH:
421			m->m_len = sizeof(int);
422			*mtod(m, int *) = tp->t_flags & TF_NOPUSH;
423			break;
424		case TCP_MAXSEG:
425			m->m_len = sizeof(int);
426			*mtod(m, int *) = tp->t_maxseg;
427			break;
428		case TCP_SACK_ENABLE:
429			m->m_len = sizeof(int);
430			*mtod(m, int *) = tp->sack_enable;
431			break;
432		case TCP_INFO:
433			error = tcp_fill_info(tp, so, m);
434			break;
435#ifdef TCP_SIGNATURE
436		case TCP_MD5SIG:
437			m->m_len = sizeof(int);
438			*mtod(m, int *) = tp->t_flags & TF_SIGNATURE;
439			break;
440#endif
441		default:
442			error = ENOPROTOOPT;
443			break;
444		}
445		break;
446	}
447	return (error);
448}
449
450/*
451 * Attach TCP protocol to socket, allocating
452 * internet protocol control block, tcp control block,
453 * buffer space, and entering LISTEN state to accept connections.
454 */
455int
456tcp_attach(struct socket *so, int proto, int wait)
457{
458	struct inpcbtable *table;
459	struct tcpcb *tp;
460	struct inpcb *inp;
461	int error;
462
463	if (so->so_pcb)
464		return EISCONN;
465	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0 ||
466	    sbcheckreserve(so->so_snd.sb_wat, tcp_sendspace) ||
467	    sbcheckreserve(so->so_rcv.sb_wat, tcp_recvspace)) {
468		error = soreserve(so, tcp_sendspace, tcp_recvspace);
469		if (error)
470			return (error);
471	}
472
473	NET_ASSERT_LOCKED();
474#ifdef INET6
475	if (so->so_proto->pr_domain->dom_family == PF_INET6)
476		table = &tcb6table;
477	else
478#endif
479		table = &tcbtable;
480	error = in_pcballoc(so, table, wait);
481	if (error)
482		return (error);
483	inp = sotoinpcb(so);
484	tp = tcp_newtcpcb(inp, wait);
485	if (tp == NULL) {
486		unsigned int nofd = so->so_state & SS_NOFDREF;	/* XXX */
487
488		so->so_state &= ~SS_NOFDREF;	/* don't free the socket yet */
489		in_pcbdetach(inp);
490		so->so_state |= nofd;
491		return (ENOBUFS);
492	}
493	tp->t_state = TCPS_CLOSED;
494#ifdef INET6
495	if (ISSET(inp->inp_flags, INP_IPV6))
496		tp->pf = PF_INET6;
497	else
498#endif
499		tp->pf = PF_INET;
500	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
501		so->so_linger = TCP_LINGERTIME;
502
503	if (so->so_options & SO_DEBUG)
504		tcp_trace(TA_USER, TCPS_CLOSED, tp, tp, NULL, PRU_ATTACH, 0);
505	return (0);
506}
507
508int
509tcp_detach(struct socket *so)
510{
511	struct inpcb *inp;
512	struct tcpcb *otp = NULL, *tp;
513	int error;
514	short ostate;
515
516	soassertlocked(so);
517
518	if ((error = tcp_sogetpcb(so, &inp, &tp)))
519		return (error);
520
521	if (so->so_options & SO_DEBUG) {
522		otp = tp;
523		ostate = tp->t_state;
524	}
525
526	/*
527	 * Detach the TCP protocol from the socket.
528	 * If the protocol state is non-embryonic, then can't
529	 * do this directly: have to initiate a PRU_DISCONNECT,
530	 * which may finish later; embryonic TCB's can just
531	 * be discarded here.
532	 */
533	tp = tcp_dodisconnect(tp);
534
535	if (otp)
536		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_DETACH, 0);
537	return (0);
538}
539
540/*
541 * Give the socket an address.
542 */
543int
544tcp_bind(struct socket *so, struct mbuf *nam, struct proc *p)
545{
546	struct inpcb *inp;
547	struct tcpcb *tp;
548	int error;
549	short ostate;
550
551	soassertlocked(so);
552
553	if ((error = tcp_sogetpcb(so, &inp, &tp)))
554		return (error);
555
556	if (so->so_options & SO_DEBUG)
557		ostate = tp->t_state;
558
559	error = in_pcbbind(inp, nam, p);
560
561	if (so->so_options & SO_DEBUG)
562		tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_BIND, 0);
563	return (error);
564}
565
566/*
567 * Prepare to accept connections.
568 */
569int
570tcp_listen(struct socket *so)
571{
572	struct inpcb *inp;
573	struct tcpcb *tp, *otp = NULL;
574	int error;
575	short ostate;
576
577	soassertlocked(so);
578
579	if ((error = tcp_sogetpcb(so, &inp, &tp)))
580		return (error);
581
582	if (so->so_options & SO_DEBUG) {
583		otp = tp;
584		ostate = tp->t_state;
585	}
586
587	if (inp->inp_lport == 0)
588		if ((error = in_pcbbind(inp, NULL, curproc)))
589			goto out;
590
591	/*
592	 * If the in_pcbbind() above is called, the tp->pf
593	 * should still be whatever it was before.
594	 */
595	tp->t_state = TCPS_LISTEN;
596
597out:
598	if (otp)
599		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_LISTEN, 0);
600	return (error);
601}
602
603/*
604 * Initiate connection to peer.
605 * Create a template for use in transmissions on this connection.
606 * Enter SYN_SENT state, and mark socket as connecting.
607 * Start keep-alive timer, and seed output sequence space.
608 * Send initial segment on connection.
609 */
610int
611tcp_connect(struct socket *so, struct mbuf *nam)
612{
613	struct inpcb *inp;
614	struct tcpcb *tp, *otp = NULL;
615	int error;
616	short ostate;
617
618	soassertlocked(so);
619
620	if ((error = tcp_sogetpcb(so, &inp, &tp)))
621		return (error);
622
623	if (so->so_options & SO_DEBUG) {
624		otp = tp;
625		ostate = tp->t_state;
626	}
627
628#ifdef INET6
629	if (ISSET(inp->inp_flags, INP_IPV6)) {
630		struct sockaddr_in6 *sin6;
631
632		if ((error = in6_nam2sin6(nam, &sin6)))
633			goto out;
634		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr) ||
635		    IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
636			error = EINVAL;
637			goto out;
638		}
639	} else
640#endif
641	{
642		struct sockaddr_in *sin;
643
644		if ((error = in_nam2sin(nam, &sin)))
645			goto out;
646		if ((sin->sin_addr.s_addr == INADDR_ANY) ||
647		    (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
648		    IN_MULTICAST(sin->sin_addr.s_addr) ||
649		    in_broadcast(sin->sin_addr, inp->inp_rtableid)) {
650			error = EINVAL;
651			goto out;
652		}
653	}
654	error = in_pcbconnect(inp, nam);
655	if (error)
656		goto out;
657
658	tp->t_template = tcp_template(tp);
659	if (tp->t_template == 0) {
660		in_pcbunset_faddr(inp);
661		in_pcbdisconnect(inp);
662		error = ENOBUFS;
663		goto out;
664	}
665
666	so->so_state |= SS_CONNECTOUT;
667
668	/* Compute window scaling to request.  */
669	tcp_rscale(tp, sb_max);
670
671	soisconnecting(so);
672	tcpstat_inc(tcps_connattempt);
673	tp->t_state = TCPS_SYN_SENT;
674	TCP_TIMER_ARM(tp, TCPT_KEEP, tcptv_keep_init);
675	tcp_set_iss_tsm(tp);
676	tcp_sendseqinit(tp);
677	tp->snd_last = tp->snd_una;
678	error = tcp_output(tp);
679
680out:
681	if (otp)
682		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_CONNECT, 0);
683	return (error);
684}
685
686/*
687 * Accept a connection.  Essentially all the work is done at higher
688 * levels; just return the address of the peer, storing through addr.
689 */
690int
691tcp_accept(struct socket *so, struct mbuf *nam)
692{
693	struct inpcb *inp;
694	struct tcpcb *tp;
695	int error;
696
697	soassertlocked(so);
698
699	if ((error = tcp_sogetpcb(so, &inp, &tp)))
700		return (error);
701
702	in_setpeeraddr(inp, nam);
703
704	if (so->so_options & SO_DEBUG)
705		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL, PRU_ACCEPT, 0);
706	return (0);
707}
708
709/*
710 * Initiate disconnect from peer.
711 * If connection never passed embryonic stage, just drop;
712 * else if don't need to let data drain, then can just drop anyways,
713 * else have to begin TCP shutdown process: mark socket disconnecting,
714 * drain unread data, state switch to reflect user close, and
715 * send segment (e.g. FIN) to peer.  Socket will be really disconnected
716 * when peer sends FIN and acks ours.
717 *
718 * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
719 */
720int
721tcp_disconnect(struct socket *so)
722{
723	struct inpcb *inp;
724	struct tcpcb *tp, *otp = NULL;
725	int error;
726	short ostate;
727
728	soassertlocked(so);
729
730	if ((error = tcp_sogetpcb(so, &inp, &tp)))
731		return (error);
732
733	if (so->so_options & SO_DEBUG) {
734		otp = tp;
735		ostate = tp->t_state;
736	}
737
738	tp = tcp_dodisconnect(tp);
739
740	if (otp)
741		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_DISCONNECT, 0);
742	return (0);
743}
744
745/*
746 * Mark the connection as being incapable of further output.
747 */
748int
749tcp_shutdown(struct socket *so)
750{
751	struct inpcb *inp;
752	struct tcpcb *tp, *otp = NULL;
753	int error;
754	short ostate;
755
756	soassertlocked(so);
757
758	if ((error = tcp_sogetpcb(so, &inp, &tp)))
759		return (error);
760
761	if (so->so_options & SO_DEBUG) {
762		otp = tp;
763		ostate = tp->t_state;
764	}
765
766	if (so->so_snd.sb_state & SS_CANTSENDMORE)
767		goto out;
768
769	socantsendmore(so);
770	tp = tcp_usrclosed(tp);
771	if (tp)
772		error = tcp_output(tp);
773
774out:
775	if (otp)
776		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_SHUTDOWN, 0);
777	return (error);
778}
779
780/*
781 * After a receive, possibly send window update to peer.
782 */
783void
784tcp_rcvd(struct socket *so)
785{
786	struct inpcb *inp;
787	struct tcpcb *tp;
788	short ostate;
789
790	soassertlocked(so);
791
792	if (tcp_sogetpcb(so, &inp, &tp))
793		return;
794
795	if (so->so_options & SO_DEBUG)
796		ostate = tp->t_state;
797
798	/*
799	 * soreceive() calls this function when a user receives
800	 * ancillary data on a listening socket. We don't call
801	 * tcp_output in such a case, since there is no header
802	 * template for a listening socket and hence the kernel
803	 * will panic.
804	 */
805	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) != 0)
806		(void) tcp_output(tp);
807
808	if (so->so_options & SO_DEBUG)
809		tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_RCVD, 0);
810}
811
812/*
813 * Do a send by putting data in output queue and updating urgent
814 * marker if URG set.  Possibly send more data.
815 */
816int
817tcp_send(struct socket *so, struct mbuf *m, struct mbuf *nam,
818    struct mbuf *control)
819{
820	struct inpcb *inp;
821	struct tcpcb *tp;
822	int error;
823	short ostate;
824
825	soassertlocked(so);
826
827	if (control && control->m_len) {
828		error = EINVAL;
829		goto out;
830	}
831
832	if ((error = tcp_sogetpcb(so, &inp, &tp)))
833		goto out;
834
835	if (so->so_options & SO_DEBUG)
836		ostate = tp->t_state;
837
838	sbappendstream(so, &so->so_snd, m);
839	m = NULL;
840
841	error = tcp_output(tp);
842
843	if (so->so_options & SO_DEBUG)
844		tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_SEND, 0);
845
846out:
847	m_freem(control);
848	m_freem(m);
849
850	return (error);
851}
852
853/*
854 * Abort the TCP.
855 */
856void
857tcp_abort(struct socket *so)
858{
859	struct inpcb *inp;
860	struct tcpcb *tp, *otp = NULL;
861	short ostate;
862
863	soassertlocked(so);
864
865	if (tcp_sogetpcb(so, &inp, &tp))
866		return;
867
868	if (so->so_options & SO_DEBUG) {
869		otp = tp;
870		ostate = tp->t_state;
871	}
872
873	tp = tcp_drop(tp, ECONNABORTED);
874
875	if (otp)
876		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_ABORT, 0);
877}
878
879int
880tcp_sense(struct socket *so, struct stat *ub)
881{
882	struct inpcb *inp;
883	struct tcpcb *tp;
884	int error;
885
886	soassertlocked(so);
887
888	if ((error = tcp_sogetpcb(so, &inp, &tp)))
889		return (error);
890
891	ub->st_blksize = so->so_snd.sb_hiwat;
892
893	if (so->so_options & SO_DEBUG)
894		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL, PRU_SENSE, 0);
895	return (0);
896}
897
898int
899tcp_rcvoob(struct socket *so, struct mbuf *m, int flags)
900{
901	struct inpcb *inp;
902	struct tcpcb *tp;
903	int error;
904
905	soassertlocked(so);
906
907	if ((error = tcp_sogetpcb(so, &inp, &tp)))
908		return (error);
909
910	if ((so->so_oobmark == 0 &&
911	    (so->so_rcv.sb_state & SS_RCVATMARK) == 0) ||
912	    so->so_options & SO_OOBINLINE ||
913	    tp->t_oobflags & TCPOOB_HADDATA) {
914		error = EINVAL;
915		goto out;
916	}
917	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
918		error = EWOULDBLOCK;
919		goto out;
920	}
921	m->m_len = 1;
922	*mtod(m, caddr_t) = tp->t_iobc;
923	if ((flags & MSG_PEEK) == 0)
924		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
925out:
926	if (so->so_options & SO_DEBUG)
927		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL, PRU_RCVOOB, 0);
928	return (error);
929}
930
931int
932tcp_sendoob(struct socket *so, struct mbuf *m, struct mbuf *nam,
933    struct mbuf *control)
934{
935	struct inpcb *inp;
936	struct tcpcb *tp;
937	int error;
938	short ostate;
939
940	soassertlocked(so);
941
942	if (control && control->m_len) {
943		error = EINVAL;
944		goto release;
945	}
946
947	if ((error = tcp_sogetpcb(so, &inp, &tp)))
948		goto release;
949
950	if (so->so_options & SO_DEBUG)
951		ostate = tp->t_state;
952
953	if (sbspace(so, &so->so_snd) < -512) {
954		error = ENOBUFS;
955		goto out;
956	}
957
958	/*
959	 * According to RFC961 (Assigned Protocols),
960	 * the urgent pointer points to the last octet
961	 * of urgent data.  We continue, however,
962	 * to consider it to indicate the first octet
963	 * of data past the urgent section.
964	 * Otherwise, snd_up should be one lower.
965	 */
966	sbappendstream(so, &so->so_snd, m);
967	m = NULL;
968	tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
969	tp->t_force = 1;
970	error = tcp_output(tp);
971	tp->t_force = 0;
972
973out:
974	if (so->so_options & SO_DEBUG)
975		tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_SENDOOB, 0);
976
977release:
978	m_freem(control);
979	m_freem(m);
980
981	return (error);
982}
983
984int
985tcp_sockaddr(struct socket *so, struct mbuf *nam)
986{
987	struct inpcb *inp;
988	struct tcpcb *tp;
989	int error;
990
991	soassertlocked(so);
992
993	if ((error = tcp_sogetpcb(so, &inp, &tp)))
994		return (error);
995
996	in_setsockaddr(inp, nam);
997
998	if (so->so_options & SO_DEBUG)
999		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL,
1000		    PRU_SOCKADDR, 0);
1001	return (0);
1002}
1003
1004int
1005tcp_peeraddr(struct socket *so, struct mbuf *nam)
1006{
1007	struct inpcb *inp;
1008	struct tcpcb *tp;
1009	int error;
1010
1011	soassertlocked(so);
1012
1013	if ((error = tcp_sogetpcb(so, &inp, &tp)))
1014		return (error);
1015
1016	in_setpeeraddr(inp, nam);
1017
1018	if (so->so_options & SO_DEBUG)
1019		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL, PRU_PEERADDR, 0);
1020	return (0);
1021}
1022
1023/*
1024 * Initiate (or continue) disconnect.
1025 * If embryonic state, just send reset (once).
1026 * If in ``let data drain'' option and linger null, just drop.
1027 * Otherwise (hard), mark socket disconnecting and drop
1028 * current input data; switch states based on user close, and
1029 * send segment to peer (with FIN).
1030 */
1031struct tcpcb *
1032tcp_dodisconnect(struct tcpcb *tp)
1033{
1034	struct socket *so = tp->t_inpcb->inp_socket;
1035
1036	if (TCPS_HAVEESTABLISHED(tp->t_state) == 0)
1037		tp = tcp_close(tp);
1038	else if ((so->so_options & SO_LINGER) && so->so_linger == 0)
1039		tp = tcp_drop(tp, 0);
1040	else {
1041		soisdisconnecting(so);
1042		sbflush(so, &so->so_rcv);
1043		tp = tcp_usrclosed(tp);
1044		if (tp)
1045			(void) tcp_output(tp);
1046	}
1047	return (tp);
1048}
1049
1050/*
1051 * User issued close, and wish to trail through shutdown states:
1052 * if never received SYN, just forget it.  If got a SYN from peer,
1053 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1054 * If already got a FIN from peer, then almost done; go to LAST_ACK
1055 * state.  In all other cases, have already sent FIN to peer (e.g.
1056 * after PRU_SHUTDOWN), and just have to play tedious game waiting
1057 * for peer to send FIN or not respond to keep-alives, etc.
1058 * We can let the user exit from the close as soon as the FIN is acked.
1059 */
1060struct tcpcb *
1061tcp_usrclosed(struct tcpcb *tp)
1062{
1063
1064	switch (tp->t_state) {
1065
1066	case TCPS_CLOSED:
1067	case TCPS_LISTEN:
1068	case TCPS_SYN_SENT:
1069		tp->t_state = TCPS_CLOSED;
1070		tp = tcp_close(tp);
1071		break;
1072
1073	case TCPS_SYN_RECEIVED:
1074	case TCPS_ESTABLISHED:
1075		tp->t_state = TCPS_FIN_WAIT_1;
1076		break;
1077
1078	case TCPS_CLOSE_WAIT:
1079		tp->t_state = TCPS_LAST_ACK;
1080		break;
1081	}
1082	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1083		soisdisconnected(tp->t_inpcb->inp_socket);
1084		/*
1085		 * If we are in FIN_WAIT_2, we arrived here because the
1086		 * application did a shutdown of the send side.  Like the
1087		 * case of a transition from FIN_WAIT_1 to FIN_WAIT_2 after
1088		 * a full close, we start a timer to make sure sockets are
1089		 * not left in FIN_WAIT_2 forever.
1090		 */
1091		if (tp->t_state == TCPS_FIN_WAIT_2)
1092			TCP_TIMER_ARM(tp, TCPT_2MSL, tcp_maxidle);
1093	}
1094	return (tp);
1095}
1096
1097/*
1098 * Look up a socket for ident or tcpdrop, ...
1099 */
1100int
1101tcp_ident(void *oldp, size_t *oldlenp, void *newp, size_t newlen, int dodrop)
1102{
1103	int error = 0;
1104	struct tcp_ident_mapping tir;
1105	struct inpcb *inp;
1106	struct tcpcb *tp = NULL;
1107	struct sockaddr_in *fin, *lin;
1108#ifdef INET6
1109	struct sockaddr_in6 *fin6, *lin6;
1110	struct in6_addr f6, l6;
1111#endif
1112
1113	NET_ASSERT_LOCKED();
1114
1115	if (dodrop) {
1116		if (oldp != NULL || *oldlenp != 0)
1117			return (EINVAL);
1118		if (newp == NULL)
1119			return (EPERM);
1120		if (newlen < sizeof(tir))
1121			return (ENOMEM);
1122		if ((error = copyin(newp, &tir, sizeof (tir))) != 0 )
1123			return (error);
1124	} else {
1125		if (oldp == NULL)
1126			return (EINVAL);
1127		if (*oldlenp < sizeof(tir))
1128			return (ENOMEM);
1129		if (newp != NULL || newlen != 0)
1130			return (EINVAL);
1131		if ((error = copyin(oldp, &tir, sizeof (tir))) != 0 )
1132			return (error);
1133	}
1134	switch (tir.faddr.ss_family) {
1135#ifdef INET6
1136	case AF_INET6:
1137		fin6 = (struct sockaddr_in6 *)&tir.faddr;
1138		error = in6_embedscope(&f6, fin6, NULL, NULL);
1139		if (error)
1140			return EINVAL;	/*?*/
1141		lin6 = (struct sockaddr_in6 *)&tir.laddr;
1142		error = in6_embedscope(&l6, lin6, NULL, NULL);
1143		if (error)
1144			return EINVAL;	/*?*/
1145		break;
1146#endif
1147	case AF_INET:
1148		fin = (struct sockaddr_in *)&tir.faddr;
1149		lin = (struct sockaddr_in *)&tir.laddr;
1150		break;
1151	default:
1152		return (EINVAL);
1153	}
1154
1155	switch (tir.faddr.ss_family) {
1156#ifdef INET6
1157	case AF_INET6:
1158		inp = in6_pcblookup(&tcb6table, &f6,
1159		    fin6->sin6_port, &l6, lin6->sin6_port, tir.rdomain);
1160		break;
1161#endif
1162	case AF_INET:
1163		inp = in_pcblookup(&tcbtable, fin->sin_addr,
1164		    fin->sin_port, lin->sin_addr, lin->sin_port, tir.rdomain);
1165		break;
1166	default:
1167		unhandled_af(tir.faddr.ss_family);
1168	}
1169
1170	if (dodrop) {
1171		if (inp && (tp = intotcpcb(inp)) &&
1172		    ((inp->inp_socket->so_options & SO_ACCEPTCONN) == 0))
1173			tp = tcp_drop(tp, ECONNABORTED);
1174		else
1175			error = ESRCH;
1176		in_pcbunref(inp);
1177		return (error);
1178	}
1179
1180	if (inp == NULL) {
1181		tcpstat_inc(tcps_pcbhashmiss);
1182		switch (tir.faddr.ss_family) {
1183#ifdef INET6
1184		case AF_INET6:
1185			inp = in6_pcblookup_listen(&tcb6table,
1186			    &l6, lin6->sin6_port, NULL, tir.rdomain);
1187			break;
1188#endif
1189		case AF_INET:
1190			inp = in_pcblookup_listen(&tcbtable,
1191			    lin->sin_addr, lin->sin_port, NULL, tir.rdomain);
1192			break;
1193		}
1194	}
1195
1196	if (inp != NULL && (inp->inp_socket->so_state & SS_CONNECTOUT)) {
1197		tir.ruid = inp->inp_socket->so_ruid;
1198		tir.euid = inp->inp_socket->so_euid;
1199	} else {
1200		tir.ruid = -1;
1201		tir.euid = -1;
1202	}
1203
1204	*oldlenp = sizeof (tir);
1205	error = copyout((void *)&tir, oldp, sizeof (tir));
1206	in_pcbunref(inp);
1207	return (error);
1208}
1209
1210int
1211tcp_sysctl_tcpstat(void *oldp, size_t *oldlenp, void *newp)
1212{
1213	uint64_t counters[tcps_ncounters];
1214	struct tcpstat tcpstat;
1215	struct syn_cache_set *set;
1216	int i = 0;
1217
1218#define ASSIGN(field)	do { tcpstat.field = counters[i++]; } while (0)
1219
1220	memset(&tcpstat, 0, sizeof tcpstat);
1221	counters_read(tcpcounters, counters, nitems(counters), NULL);
1222	ASSIGN(tcps_connattempt);
1223	ASSIGN(tcps_accepts);
1224	ASSIGN(tcps_connects);
1225	ASSIGN(tcps_drops);
1226	ASSIGN(tcps_conndrops);
1227	ASSIGN(tcps_closed);
1228	ASSIGN(tcps_segstimed);
1229	ASSIGN(tcps_rttupdated);
1230	ASSIGN(tcps_delack);
1231	ASSIGN(tcps_timeoutdrop);
1232	ASSIGN(tcps_rexmttimeo);
1233	ASSIGN(tcps_persisttimeo);
1234	ASSIGN(tcps_persistdrop);
1235	ASSIGN(tcps_keeptimeo);
1236	ASSIGN(tcps_keepprobe);
1237	ASSIGN(tcps_keepdrops);
1238	ASSIGN(tcps_sndtotal);
1239	ASSIGN(tcps_sndpack);
1240	ASSIGN(tcps_sndbyte);
1241	ASSIGN(tcps_sndrexmitpack);
1242	ASSIGN(tcps_sndrexmitbyte);
1243	ASSIGN(tcps_sndrexmitfast);
1244	ASSIGN(tcps_sndacks);
1245	ASSIGN(tcps_sndprobe);
1246	ASSIGN(tcps_sndurg);
1247	ASSIGN(tcps_sndwinup);
1248	ASSIGN(tcps_sndctrl);
1249	ASSIGN(tcps_rcvtotal);
1250	ASSIGN(tcps_rcvpack);
1251	ASSIGN(tcps_rcvbyte);
1252	ASSIGN(tcps_rcvbadsum);
1253	ASSIGN(tcps_rcvbadoff);
1254	ASSIGN(tcps_rcvmemdrop);
1255	ASSIGN(tcps_rcvnosec);
1256	ASSIGN(tcps_rcvshort);
1257	ASSIGN(tcps_rcvduppack);
1258	ASSIGN(tcps_rcvdupbyte);
1259	ASSIGN(tcps_rcvpartduppack);
1260	ASSIGN(tcps_rcvpartdupbyte);
1261	ASSIGN(tcps_rcvoopack);
1262	ASSIGN(tcps_rcvoobyte);
1263	ASSIGN(tcps_rcvpackafterwin);
1264	ASSIGN(tcps_rcvbyteafterwin);
1265	ASSIGN(tcps_rcvafterclose);
1266	ASSIGN(tcps_rcvwinprobe);
1267	ASSIGN(tcps_rcvdupack);
1268	ASSIGN(tcps_rcvacktoomuch);
1269	ASSIGN(tcps_rcvacktooold);
1270	ASSIGN(tcps_rcvackpack);
1271	ASSIGN(tcps_rcvackbyte);
1272	ASSIGN(tcps_rcvwinupd);
1273	ASSIGN(tcps_pawsdrop);
1274	ASSIGN(tcps_predack);
1275	ASSIGN(tcps_preddat);
1276	ASSIGN(tcps_pcbhashmiss);
1277	ASSIGN(tcps_noport);
1278	ASSIGN(tcps_badsyn);
1279	ASSIGN(tcps_dropsyn);
1280	ASSIGN(tcps_rcvbadsig);
1281	ASSIGN(tcps_rcvgoodsig);
1282	ASSIGN(tcps_inswcsum);
1283	ASSIGN(tcps_outswcsum);
1284	ASSIGN(tcps_ecn_accepts);
1285	ASSIGN(tcps_ecn_rcvece);
1286	ASSIGN(tcps_ecn_rcvcwr);
1287	ASSIGN(tcps_ecn_rcvce);
1288	ASSIGN(tcps_ecn_sndect);
1289	ASSIGN(tcps_ecn_sndece);
1290	ASSIGN(tcps_ecn_sndcwr);
1291	ASSIGN(tcps_cwr_ecn);
1292	ASSIGN(tcps_cwr_frecovery);
1293	ASSIGN(tcps_cwr_timeout);
1294	ASSIGN(tcps_sc_added);
1295	ASSIGN(tcps_sc_completed);
1296	ASSIGN(tcps_sc_timed_out);
1297	ASSIGN(tcps_sc_overflowed);
1298	ASSIGN(tcps_sc_reset);
1299	ASSIGN(tcps_sc_unreach);
1300	ASSIGN(tcps_sc_bucketoverflow);
1301	ASSIGN(tcps_sc_aborted);
1302	ASSIGN(tcps_sc_dupesyn);
1303	ASSIGN(tcps_sc_dropped);
1304	ASSIGN(tcps_sc_collisions);
1305	ASSIGN(tcps_sc_retransmitted);
1306	ASSIGN(tcps_sc_seedrandom);
1307	ASSIGN(tcps_sc_hash_size);
1308	ASSIGN(tcps_sc_entry_count);
1309	ASSIGN(tcps_sc_entry_limit);
1310	ASSIGN(tcps_sc_bucket_maxlen);
1311	ASSIGN(tcps_sc_bucket_limit);
1312	ASSIGN(tcps_sc_uses_left);
1313	ASSIGN(tcps_conndrained);
1314	ASSIGN(tcps_sack_recovery_episode);
1315	ASSIGN(tcps_sack_rexmits);
1316	ASSIGN(tcps_sack_rexmit_bytes);
1317	ASSIGN(tcps_sack_rcv_opts);
1318	ASSIGN(tcps_sack_snd_opts);
1319	ASSIGN(tcps_sack_drop_opts);
1320	ASSIGN(tcps_outswtso);
1321	ASSIGN(tcps_outhwtso);
1322	ASSIGN(tcps_outpkttso);
1323	ASSIGN(tcps_outbadtso);
1324	ASSIGN(tcps_inswlro);
1325	ASSIGN(tcps_inhwlro);
1326	ASSIGN(tcps_inpktlro);
1327	ASSIGN(tcps_inbadlro);
1328
1329#undef ASSIGN
1330
1331	mtx_enter(&syn_cache_mtx);
1332	set = &tcp_syn_cache[tcp_syn_cache_active];
1333	tcpstat.tcps_sc_hash_size = set->scs_size;
1334	tcpstat.tcps_sc_entry_count = set->scs_count;
1335	tcpstat.tcps_sc_entry_limit = tcp_syn_cache_limit;
1336	tcpstat.tcps_sc_bucket_maxlen = 0;
1337	for (i = 0; i < set->scs_size; i++) {
1338		if (tcpstat.tcps_sc_bucket_maxlen <
1339		    set->scs_buckethead[i].sch_length)
1340			tcpstat.tcps_sc_bucket_maxlen =
1341				set->scs_buckethead[i].sch_length;
1342	}
1343	tcpstat.tcps_sc_bucket_limit = tcp_syn_bucket_limit;
1344	tcpstat.tcps_sc_uses_left = set->scs_use;
1345	mtx_leave(&syn_cache_mtx);
1346
1347	return (sysctl_rdstruct(oldp, oldlenp, newp,
1348	    &tcpstat, sizeof(tcpstat)));
1349}
1350
1351/*
1352 * Sysctl for tcp variables.
1353 */
1354int
1355tcp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
1356    size_t newlen)
1357{
1358	int error, nval;
1359
1360	/* All sysctl names at this level are terminal. */
1361	if (namelen != 1)
1362		return (ENOTDIR);
1363
1364	switch (name[0]) {
1365	case TCPCTL_KEEPINITTIME:
1366		NET_LOCK();
1367		nval = tcptv_keep_init / TCP_TIME(1);
1368		error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, &nval,
1369		    1, 3 * (TCPTV_KEEP_INIT / TCP_TIME(1)));
1370		if (!error)
1371			tcptv_keep_init = TCP_TIME(nval);
1372		NET_UNLOCK();
1373		return (error);
1374
1375	case TCPCTL_KEEPIDLE:
1376		NET_LOCK();
1377		nval = tcp_keepidle / TCP_TIME(1);
1378		error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, &nval,
1379		    1, 5 * (TCPTV_KEEP_IDLE / TCP_TIME(1)));
1380		if (!error)
1381			tcp_keepidle = TCP_TIME(nval);
1382		NET_UNLOCK();
1383		return (error);
1384
1385	case TCPCTL_KEEPINTVL:
1386		NET_LOCK();
1387		nval = tcp_keepintvl / TCP_TIME(1);
1388		error = sysctl_int_bounded(oldp, oldlenp, newp, newlen, &nval,
1389		    1, 3 * (TCPTV_KEEPINTVL / TCP_TIME(1)));
1390		if (!error)
1391			tcp_keepintvl = TCP_TIME(nval);
1392		NET_UNLOCK();
1393		return (error);
1394
1395	case TCPCTL_BADDYNAMIC:
1396		NET_LOCK();
1397		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1398		    baddynamicports.tcp, sizeof(baddynamicports.tcp));
1399		NET_UNLOCK();
1400		return (error);
1401
1402	case TCPCTL_ROOTONLY:
1403		if (newp && securelevel > 0)
1404			return (EPERM);
1405		NET_LOCK();
1406		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1407		    rootonlyports.tcp, sizeof(rootonlyports.tcp));
1408		NET_UNLOCK();
1409		return (error);
1410
1411	case TCPCTL_IDENT:
1412		NET_LOCK();
1413		error = tcp_ident(oldp, oldlenp, newp, newlen, 0);
1414		NET_UNLOCK();
1415		return (error);
1416
1417	case TCPCTL_DROP:
1418		NET_LOCK();
1419		error = tcp_ident(oldp, oldlenp, newp, newlen, 1);
1420		NET_UNLOCK();
1421		return (error);
1422
1423	case TCPCTL_REASS_LIMIT:
1424		NET_LOCK();
1425		nval = tcp_reass_limit;
1426		error = sysctl_int(oldp, oldlenp, newp, newlen, &nval);
1427		if (!error && nval != tcp_reass_limit) {
1428			error = pool_sethardlimit(&tcpqe_pool, nval, NULL, 0);
1429			if (!error)
1430				tcp_reass_limit = nval;
1431		}
1432		NET_UNLOCK();
1433		return (error);
1434
1435	case TCPCTL_SACKHOLE_LIMIT:
1436		NET_LOCK();
1437		nval = tcp_sackhole_limit;
1438		error = sysctl_int(oldp, oldlenp, newp, newlen, &nval);
1439		if (!error && nval != tcp_sackhole_limit) {
1440			error = pool_sethardlimit(&sackhl_pool, nval, NULL, 0);
1441			if (!error)
1442				tcp_sackhole_limit = nval;
1443		}
1444		NET_UNLOCK();
1445		return (error);
1446
1447	case TCPCTL_STATS:
1448		return (tcp_sysctl_tcpstat(oldp, oldlenp, newp));
1449
1450	case TCPCTL_SYN_USE_LIMIT:
1451		NET_LOCK();
1452		error = sysctl_int_bounded(oldp, oldlenp, newp, newlen,
1453		    &tcp_syn_use_limit, 0, INT_MAX);
1454		if (!error && newp != NULL) {
1455			/*
1456			 * Global tcp_syn_use_limit is used when reseeding a
1457			 * new cache.  Also update the value in active cache.
1458			 */
1459			mtx_enter(&syn_cache_mtx);
1460			if (tcp_syn_cache[0].scs_use > tcp_syn_use_limit)
1461				tcp_syn_cache[0].scs_use = tcp_syn_use_limit;
1462			if (tcp_syn_cache[1].scs_use > tcp_syn_use_limit)
1463				tcp_syn_cache[1].scs_use = tcp_syn_use_limit;
1464			mtx_leave(&syn_cache_mtx);
1465		}
1466		NET_UNLOCK();
1467		return (error);
1468
1469	case TCPCTL_SYN_HASH_SIZE:
1470		NET_LOCK();
1471		nval = tcp_syn_hash_size;
1472		error = sysctl_int_bounded(oldp, oldlenp, newp, newlen,
1473		    &nval, 1, 100000);
1474		if (!error && nval != tcp_syn_hash_size) {
1475			/*
1476			 * If global hash size has been changed,
1477			 * switch sets as soon as possible.  Then
1478			 * the actual hash array will be reallocated.
1479			 */
1480			mtx_enter(&syn_cache_mtx);
1481			if (tcp_syn_cache[0].scs_size != nval)
1482				tcp_syn_cache[0].scs_use = 0;
1483			if (tcp_syn_cache[1].scs_size != nval)
1484				tcp_syn_cache[1].scs_use = 0;
1485			tcp_syn_hash_size = nval;
1486			mtx_leave(&syn_cache_mtx);
1487		}
1488		NET_UNLOCK();
1489		return (error);
1490
1491	default:
1492		NET_LOCK();
1493		error = sysctl_bounded_arr(tcpctl_vars, nitems(tcpctl_vars),
1494		    name, namelen, oldp, oldlenp, newp, newlen);
1495		NET_UNLOCK();
1496		return (error);
1497	}
1498	/* NOTREACHED */
1499}
1500
1501/*
1502 * Scale the send buffer so that inflight data is not accounted against
1503 * the limit. The buffer will scale with the congestion window, if the
1504 * the receiver stops acking data the window will shrink and therefore
1505 * the buffer size will shrink as well.
1506 * In low memory situation try to shrink the buffer to the initial size
1507 * disabling the send buffer scaling as long as the situation persists.
1508 */
1509void
1510tcp_update_sndspace(struct tcpcb *tp)
1511{
1512	struct socket *so = tp->t_inpcb->inp_socket;
1513	u_long nmax = so->so_snd.sb_hiwat;
1514
1515	if (sbchecklowmem()) {
1516		/* low on memory try to get rid of some */
1517		if (tcp_sendspace < nmax)
1518			nmax = tcp_sendspace;
1519	} else if (so->so_snd.sb_wat != tcp_sendspace)
1520		/* user requested buffer size, auto-scaling disabled */
1521		nmax = so->so_snd.sb_wat;
1522	else
1523		/* automatic buffer scaling */
1524		nmax = MIN(sb_max, so->so_snd.sb_wat + tp->snd_max -
1525		    tp->snd_una);
1526
1527	/* a writable socket must be preserved because of poll(2) semantics */
1528	if (sbspace(so, &so->so_snd) >= so->so_snd.sb_lowat) {
1529		if (nmax < so->so_snd.sb_cc + so->so_snd.sb_lowat)
1530			nmax = so->so_snd.sb_cc + so->so_snd.sb_lowat;
1531		/* keep in sync with sbreserve() calculation */
1532		if (nmax * 8 < so->so_snd.sb_mbcnt + so->so_snd.sb_lowat)
1533			nmax = (so->so_snd.sb_mbcnt+so->so_snd.sb_lowat+7) / 8;
1534	}
1535
1536	/* round to MSS boundary */
1537	nmax = roundup(nmax, tp->t_maxseg);
1538
1539	if (nmax != so->so_snd.sb_hiwat)
1540		sbreserve(so, &so->so_snd, nmax);
1541}
1542
1543/*
1544 * Scale the recv buffer by looking at how much data was transferred in
1545 * one approximated RTT. If more than a big part of the recv buffer was
1546 * transferred during that time we increase the buffer by a constant.
1547 * In low memory situation try to shrink the buffer to the initial size.
1548 */
1549void
1550tcp_update_rcvspace(struct tcpcb *tp)
1551{
1552	struct socket *so = tp->t_inpcb->inp_socket;
1553	u_long nmax = so->so_rcv.sb_hiwat;
1554
1555	if (sbchecklowmem()) {
1556		/* low on memory try to get rid of some */
1557		if (tcp_recvspace < nmax)
1558			nmax = tcp_recvspace;
1559	} else if (so->so_rcv.sb_wat != tcp_recvspace)
1560		/* user requested buffer size, auto-scaling disabled */
1561		nmax = so->so_rcv.sb_wat;
1562	else {
1563		/* automatic buffer scaling */
1564		if (tp->rfbuf_cnt > so->so_rcv.sb_hiwat / 8 * 7)
1565			nmax = MIN(sb_max, so->so_rcv.sb_hiwat +
1566			    tcp_autorcvbuf_inc);
1567	}
1568
1569	/* a readable socket must be preserved because of poll(2) semantics */
1570	if (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat &&
1571	    nmax < so->so_snd.sb_lowat)
1572		nmax = so->so_snd.sb_lowat;
1573
1574	if (nmax == so->so_rcv.sb_hiwat)
1575		return;
1576
1577	/* round to MSS boundary */
1578	nmax = roundup(nmax, tp->t_maxseg);
1579	sbreserve(so, &so->so_rcv, nmax);
1580}
1581