xref: /openbsd/sys/netinet/tcp_usrreq.c (revision e835bce2)
1 /*	$OpenBSD: tcp_usrreq.c,v 1.240 2025/01/16 11:59:20 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 /*
106  * Locks used to protect global variables in this file:
107  *	I	immutable after creation
108  */
109 
110 #ifndef TCP_SENDSPACE
111 #define	TCP_SENDSPACE	1024*16
112 #endif
113 u_int	tcp_sendspace = TCP_SENDSPACE;		/* [I] */
114 #ifndef TCP_RECVSPACE
115 #define	TCP_RECVSPACE	1024*16
116 #endif
117 u_int	tcp_recvspace = TCP_RECVSPACE;		/* [I] */
118 u_int	tcp_autorcvbuf_inc = 16 * 1024;		/* [I] */
119 
120 const struct pr_usrreqs tcp_usrreqs = {
121 	.pru_attach	= tcp_attach,
122 	.pru_detach	= tcp_detach,
123 	.pru_bind	= tcp_bind,
124 	.pru_listen	= tcp_listen,
125 	.pru_connect	= tcp_connect,
126 	.pru_accept	= tcp_accept,
127 	.pru_disconnect	= tcp_disconnect,
128 	.pru_shutdown	= tcp_shutdown,
129 	.pru_rcvd	= tcp_rcvd,
130 	.pru_send	= tcp_send,
131 	.pru_abort	= tcp_abort,
132 	.pru_sense	= tcp_sense,
133 	.pru_rcvoob	= tcp_rcvoob,
134 	.pru_sendoob	= tcp_sendoob,
135 	.pru_control	= in_control,
136 	.pru_sockaddr	= tcp_sockaddr,
137 	.pru_peeraddr	= tcp_peeraddr,
138 };
139 
140 #ifdef INET6
141 const struct pr_usrreqs tcp6_usrreqs = {
142 	.pru_attach	= tcp_attach,
143 	.pru_detach	= tcp_detach,
144 	.pru_bind	= tcp_bind,
145 	.pru_listen	= tcp_listen,
146 	.pru_connect	= tcp_connect,
147 	.pru_accept	= tcp_accept,
148 	.pru_disconnect	= tcp_disconnect,
149 	.pru_shutdown	= tcp_shutdown,
150 	.pru_rcvd	= tcp_rcvd,
151 	.pru_send	= tcp_send,
152 	.pru_abort	= tcp_abort,
153 	.pru_sense	= tcp_sense,
154 	.pru_rcvoob	= tcp_rcvoob,
155 	.pru_sendoob	= tcp_sendoob,
156 	.pru_control	= in6_control,
157 	.pru_sockaddr	= tcp_sockaddr,
158 	.pru_peeraddr	= tcp_peeraddr,
159 };
160 #endif
161 
162 const struct sysctl_bounded_args tcpctl_vars[] = {
163 	{ TCPCTL_KEEPINITTIME, &tcp_keepinit_sec, 1,
164 	    3 * TCPTV_KEEPINIT / TCP_TIME(1) },
165 	{ TCPCTL_KEEPIDLE, &tcp_keepidle_sec, 1,
166 	    5 * TCPTV_KEEPIDLE / TCP_TIME(1) },
167 	{ TCPCTL_KEEPINTVL, &tcp_keepintvl_sec, 1,
168 	    3 * TCPTV_KEEPINTVL / TCP_TIME(1) },
169 	{ TCPCTL_RFC1323, &tcp_do_rfc1323, 0, 1 },
170 	{ TCPCTL_SACK, &tcp_do_sack, 0, 1 },
171 	{ TCPCTL_MSSDFLT, &tcp_mssdflt, TCP_MSS, 65535 },
172 	{ TCPCTL_RSTPPSLIMIT, &tcp_rst_ppslim, 1, 1000 * 1000 },
173 	{ TCPCTL_ACK_ON_PUSH, &tcp_ack_on_push, 0, 1 },
174 #ifdef TCP_ECN
175 	{ TCPCTL_ECN, &tcp_do_ecn, 0, 1 },
176 #endif
177 	{ TCPCTL_SYN_CACHE_LIMIT, &tcp_syn_cache_limit, 1, 1000 * 1000 },
178 	{ TCPCTL_SYN_BUCKET_LIMIT, &tcp_syn_bucket_limit, 1, INT_MAX },
179 	{ TCPCTL_RFC3390, &tcp_do_rfc3390, 0, 2 },
180 	{ TCPCTL_ALWAYS_KEEPALIVE, &tcp_always_keepalive, 0, 1 },
181 	{ TCPCTL_TSO, &tcp_do_tso, 0, 1 },
182 };
183 
184 struct	inpcbtable tcbtable;
185 #ifdef INET6
186 struct	inpcbtable tcb6table;
187 #endif
188 
189 int	tcp_fill_info(struct tcpcb *, struct socket *, struct mbuf *);
190 int	tcp_ident(void *, size_t *, void *, size_t, int);
191 
192 static inline int tcp_sogetpcb(struct socket *, struct inpcb **,
193 		    struct tcpcb **);
194 
195 static inline int
tcp_sogetpcb(struct socket * so,struct inpcb ** rinp,struct tcpcb ** rtp)196 tcp_sogetpcb(struct socket *so, struct inpcb **rinp, struct tcpcb **rtp)
197 {
198 	struct inpcb *inp;
199 	struct tcpcb *tp;
200 
201 	/*
202 	 * When a TCP is attached to a socket, then there will be
203 	 * a (struct inpcb) pointed at by the socket, and this
204 	 * structure will point at a subsidiary (struct tcpcb).
205 	 */
206 	if ((inp = sotoinpcb(so)) == NULL || (tp = intotcpcb(inp)) == NULL) {
207 		int error;
208 
209 		if ((error = READ_ONCE(so->so_error)))
210 			return error;
211 		return EINVAL;
212 	}
213 
214 	*rinp = inp;
215 	*rtp = tp;
216 
217 	return 0;
218 }
219 
220 /*
221  * Export internal TCP state information via a struct tcp_info without
222  * leaking any sensitive information. Sequence numbers are reported
223  * relative to the initial sequence number.
224  */
225 int
tcp_fill_info(struct tcpcb * tp,struct socket * so,struct mbuf * m)226 tcp_fill_info(struct tcpcb *tp, struct socket *so, struct mbuf *m)
227 {
228 	struct proc *p = curproc;
229 	struct tcp_info *ti;
230 	u_int t = 1000;		/* msec => usec */
231 	uint64_t now;
232 
233 	if (sizeof(*ti) > MLEN) {
234 		MCLGETL(m, M_WAITOK, sizeof(*ti));
235 		if (!ISSET(m->m_flags, M_EXT))
236 			return ENOMEM;
237 	}
238 	ti = mtod(m, struct tcp_info *);
239 	m->m_len = sizeof(*ti);
240 	memset(ti, 0, sizeof(*ti));
241 	now = tcp_now();
242 
243 	ti->tcpi_state = tp->t_state;
244 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
245 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
246 	if (tp->t_flags & TF_SACK_PERMIT)
247 		ti->tcpi_options |= TCPI_OPT_SACK;
248 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
249 		ti->tcpi_options |= TCPI_OPT_WSCALE;
250 		ti->tcpi_snd_wscale = tp->snd_scale;
251 		ti->tcpi_rcv_wscale = tp->rcv_scale;
252 	}
253 #ifdef TCP_ECN
254 	if (tp->t_flags & TF_ECN_PERMIT)
255 		ti->tcpi_options |= TCPI_OPT_ECN;
256 #endif
257 
258 	ti->tcpi_rto = tp->t_rxtcur * t;
259 	ti->tcpi_snd_mss = tp->t_maxseg;
260 	ti->tcpi_rcv_mss = tp->t_peermss;
261 
262 	ti->tcpi_last_data_sent = (now - tp->t_sndtime) * t;
263 	ti->tcpi_last_ack_sent = (now - tp->t_sndacktime) * t;
264 	ti->tcpi_last_data_recv = (now - tp->t_rcvtime) * t;
265 	ti->tcpi_last_ack_recv = (now - tp->t_rcvacktime) * t;
266 
267 	ti->tcpi_rtt = ((uint64_t)tp->t_srtt * t) >>
268 	    (TCP_RTT_SHIFT + TCP_RTT_BASE_SHIFT);
269 	ti->tcpi_rttvar = ((uint64_t)tp->t_rttvar * t) >>
270 	    (TCP_RTTVAR_SHIFT + TCP_RTT_BASE_SHIFT);
271 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
272 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
273 
274 	ti->tcpi_rcv_space = tp->rcv_wnd;
275 
276 	/*
277 	 * Provide only minimal information for unprivileged processes.
278 	 */
279 	if (suser(p) != 0)
280 		return 0;
281 
282 	/* FreeBSD-specific extension fields for tcp_info.  */
283 	ti->tcpi_snd_wnd = tp->snd_wnd;
284 	ti->tcpi_snd_nxt = tp->snd_nxt - tp->iss;
285 	ti->tcpi_rcv_nxt = tp->rcv_nxt - tp->irs;
286 	/* missing tcpi_toe_tid */
287 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
288 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
289 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
290 
291 	/* OpenBSD extensions */
292 	ti->tcpi_rttmin = tp->t_rttmin * t;
293 	ti->tcpi_max_sndwnd = tp->max_sndwnd;
294 	ti->tcpi_rcv_adv = tp->rcv_adv - tp->irs;
295 	ti->tcpi_rcv_up = tp->rcv_up - tp->irs;
296 	ti->tcpi_snd_una = tp->snd_una - tp->iss;
297 	ti->tcpi_snd_up = tp->snd_up - tp->iss;
298 	ti->tcpi_snd_wl1 = tp->snd_wl1 - tp->iss;
299 	ti->tcpi_snd_wl2 = tp->snd_wl2 - tp->iss;
300 	ti->tcpi_snd_max = tp->snd_max - tp->iss;
301 
302 	ti->tcpi_ts_recent = tp->ts_recent; /* XXX value from the wire */
303 	ti->tcpi_ts_recent_age = (now - tp->ts_recent_age) * t;
304 	ti->tcpi_rfbuf_cnt = tp->rfbuf_cnt;
305 	ti->tcpi_rfbuf_ts = (now - tp->rfbuf_ts) * t;
306 
307 	mtx_enter(&so->so_rcv.sb_mtx);
308 	ti->tcpi_so_rcv_sb_cc = so->so_rcv.sb_cc;
309 	ti->tcpi_so_rcv_sb_hiwat = so->so_rcv.sb_hiwat;
310 	ti->tcpi_so_rcv_sb_lowat = so->so_rcv.sb_lowat;
311 	ti->tcpi_so_rcv_sb_wat = so->so_rcv.sb_wat;
312 	mtx_leave(&so->so_rcv.sb_mtx);
313 	mtx_enter(&so->so_snd.sb_mtx);
314 	ti->tcpi_so_snd_sb_cc = so->so_snd.sb_cc;
315 	ti->tcpi_so_snd_sb_hiwat = so->so_snd.sb_hiwat;
316 	ti->tcpi_so_snd_sb_lowat = so->so_snd.sb_lowat;
317 	ti->tcpi_so_snd_sb_wat = so->so_snd.sb_wat;
318 	mtx_leave(&so->so_snd.sb_mtx);
319 
320 	return 0;
321 }
322 
323 int
tcp_ctloutput(int op,struct socket * so,int level,int optname,struct mbuf * m)324 tcp_ctloutput(int op, struct socket *so, int level, int optname,
325     struct mbuf *m)
326 {
327 	int error = 0;
328 	struct inpcb *inp;
329 	struct tcpcb *tp;
330 	int i;
331 
332 	inp = sotoinpcb(so);
333 	if (inp == NULL)
334 		return (ECONNRESET);
335 	if (level != IPPROTO_TCP) {
336 #ifdef INET6
337 		if (ISSET(inp->inp_flags, INP_IPV6))
338 			error = ip6_ctloutput(op, so, level, optname, m);
339 		else
340 #endif
341 			error = ip_ctloutput(op, so, level, optname, m);
342 		return (error);
343 	}
344 	tp = intotcpcb(inp);
345 
346 	switch (op) {
347 
348 	case PRCO_SETOPT:
349 		switch (optname) {
350 
351 		case TCP_NODELAY:
352 			if (m == NULL || m->m_len < sizeof (int))
353 				error = EINVAL;
354 			else if (*mtod(m, int *))
355 				tp->t_flags |= TF_NODELAY;
356 			else
357 				tp->t_flags &= ~TF_NODELAY;
358 			break;
359 
360 		case TCP_NOPUSH:
361 			if (m == NULL || m->m_len < sizeof (int))
362 				error = EINVAL;
363 			else if (*mtod(m, int *))
364 				tp->t_flags |= TF_NOPUSH;
365 			else if (tp->t_flags & TF_NOPUSH) {
366 				tp->t_flags &= ~TF_NOPUSH;
367 				if (TCPS_HAVEESTABLISHED(tp->t_state))
368 					error = tcp_output(tp);
369 			}
370 			break;
371 
372 		case TCP_MAXSEG:
373 			if (m == NULL || m->m_len < sizeof (int)) {
374 				error = EINVAL;
375 				break;
376 			}
377 
378 			i = *mtod(m, int *);
379 			if (i > 0 && i <= tp->t_maxseg)
380 				tp->t_maxseg = i;
381 			else
382 				error = EINVAL;
383 			break;
384 
385 		case TCP_SACK_ENABLE:
386 			if (m == NULL || m->m_len < sizeof (int)) {
387 				error = EINVAL;
388 				break;
389 			}
390 
391 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
392 				error = EPERM;
393 				break;
394 			}
395 
396 			if (tp->t_flags & TF_SIGNATURE) {
397 				error = EPERM;
398 				break;
399 			}
400 
401 			if (*mtod(m, int *))
402 				tp->sack_enable = 1;
403 			else
404 				tp->sack_enable = 0;
405 			break;
406 #ifdef TCP_SIGNATURE
407 		case TCP_MD5SIG:
408 			if (m == NULL || m->m_len < sizeof (int)) {
409 				error = EINVAL;
410 				break;
411 			}
412 
413 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
414 				error = EPERM;
415 				break;
416 			}
417 
418 			if (*mtod(m, int *)) {
419 				tp->t_flags |= TF_SIGNATURE;
420 				tp->sack_enable = 0;
421 			} else
422 				tp->t_flags &= ~TF_SIGNATURE;
423 			break;
424 #endif /* TCP_SIGNATURE */
425 		default:
426 			error = ENOPROTOOPT;
427 			break;
428 		}
429 		break;
430 
431 	case PRCO_GETOPT:
432 		switch (optname) {
433 		case TCP_NODELAY:
434 			m->m_len = sizeof(int);
435 			*mtod(m, int *) = tp->t_flags & TF_NODELAY;
436 			break;
437 		case TCP_NOPUSH:
438 			m->m_len = sizeof(int);
439 			*mtod(m, int *) = tp->t_flags & TF_NOPUSH;
440 			break;
441 		case TCP_MAXSEG:
442 			m->m_len = sizeof(int);
443 			*mtod(m, int *) = tp->t_maxseg;
444 			break;
445 		case TCP_SACK_ENABLE:
446 			m->m_len = sizeof(int);
447 			*mtod(m, int *) = tp->sack_enable;
448 			break;
449 		case TCP_INFO:
450 			error = tcp_fill_info(tp, so, m);
451 			break;
452 #ifdef TCP_SIGNATURE
453 		case TCP_MD5SIG:
454 			m->m_len = sizeof(int);
455 			*mtod(m, int *) = tp->t_flags & TF_SIGNATURE;
456 			break;
457 #endif
458 		default:
459 			error = ENOPROTOOPT;
460 			break;
461 		}
462 		break;
463 	}
464 	return (error);
465 }
466 
467 /*
468  * Attach TCP protocol to socket, allocating
469  * internet protocol control block, tcp control block,
470  * buffer space, and entering LISTEN state to accept connections.
471  */
472 int
tcp_attach(struct socket * so,int proto,int wait)473 tcp_attach(struct socket *so, int proto, int wait)
474 {
475 	struct inpcbtable *table;
476 	struct tcpcb *tp;
477 	struct inpcb *inp;
478 	int error;
479 
480 	if (so->so_pcb)
481 		return EISCONN;
482 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0 ||
483 	    sbcheckreserve(so->so_snd.sb_wat, tcp_sendspace) ||
484 	    sbcheckreserve(so->so_rcv.sb_wat, tcp_recvspace)) {
485 		error = soreserve(so, tcp_sendspace, tcp_recvspace);
486 		if (error)
487 			return (error);
488 	}
489 
490 	NET_ASSERT_LOCKED();
491 #ifdef INET6
492 	if (so->so_proto->pr_domain->dom_family == PF_INET6)
493 		table = &tcb6table;
494 	else
495 #endif
496 		table = &tcbtable;
497 	error = in_pcballoc(so, table, wait);
498 	if (error)
499 		return (error);
500 	inp = sotoinpcb(so);
501 	tp = tcp_newtcpcb(inp, wait);
502 	if (tp == NULL) {
503 		unsigned int nofd = so->so_state & SS_NOFDREF;	/* XXX */
504 
505 		so->so_state &= ~SS_NOFDREF;	/* don't free the socket yet */
506 		in_pcbdetach(inp);
507 		so->so_state |= nofd;
508 		return (ENOBUFS);
509 	}
510 	tp->t_state = TCPS_CLOSED;
511 #ifdef INET6
512 	if (ISSET(inp->inp_flags, INP_IPV6))
513 		tp->pf = PF_INET6;
514 	else
515 #endif
516 		tp->pf = PF_INET;
517 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
518 		so->so_linger = TCP_LINGERTIME;
519 
520 	if (so->so_options & SO_DEBUG)
521 		tcp_trace(TA_USER, TCPS_CLOSED, tp, tp, NULL, PRU_ATTACH, 0);
522 	return (0);
523 }
524 
525 int
tcp_detach(struct socket * so)526 tcp_detach(struct socket *so)
527 {
528 	struct inpcb *inp;
529 	struct tcpcb *otp = NULL, *tp;
530 	int error;
531 	short ostate;
532 
533 	soassertlocked(so);
534 
535 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
536 		return (error);
537 
538 	if (so->so_options & SO_DEBUG) {
539 		otp = tp;
540 		ostate = tp->t_state;
541 	}
542 
543 	/*
544 	 * Detach the TCP protocol from the socket.
545 	 * If the protocol state is non-embryonic, then can't
546 	 * do this directly: have to initiate a PRU_DISCONNECT,
547 	 * which may finish later; embryonic TCB's can just
548 	 * be discarded here.
549 	 */
550 	tp = tcp_dodisconnect(tp);
551 
552 	if (otp)
553 		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_DETACH, 0);
554 	return (0);
555 }
556 
557 /*
558  * Give the socket an address.
559  */
560 int
tcp_bind(struct socket * so,struct mbuf * nam,struct proc * p)561 tcp_bind(struct socket *so, struct mbuf *nam, struct proc *p)
562 {
563 	struct inpcb *inp;
564 	struct tcpcb *tp;
565 	int error;
566 	short ostate;
567 
568 	soassertlocked(so);
569 
570 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
571 		return (error);
572 
573 	if (so->so_options & SO_DEBUG)
574 		ostate = tp->t_state;
575 
576 	error = in_pcbbind(inp, nam, p);
577 
578 	if (so->so_options & SO_DEBUG)
579 		tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_BIND, 0);
580 	return (error);
581 }
582 
583 /*
584  * Prepare to accept connections.
585  */
586 int
tcp_listen(struct socket * so)587 tcp_listen(struct socket *so)
588 {
589 	struct inpcb *inp;
590 	struct tcpcb *tp, *otp = NULL;
591 	int error;
592 	short ostate;
593 
594 	soassertlocked(so);
595 
596 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
597 		return (error);
598 
599 	if (so->so_options & SO_DEBUG) {
600 		otp = tp;
601 		ostate = tp->t_state;
602 	}
603 
604 	if (inp->inp_lport == 0)
605 		if ((error = in_pcbbind(inp, NULL, curproc)))
606 			goto out;
607 
608 	/*
609 	 * If the in_pcbbind() above is called, the tp->pf
610 	 * should still be whatever it was before.
611 	 */
612 	tp->t_state = TCPS_LISTEN;
613 
614 out:
615 	if (otp)
616 		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_LISTEN, 0);
617 	return (error);
618 }
619 
620 /*
621  * Initiate connection to peer.
622  * Create a template for use in transmissions on this connection.
623  * Enter SYN_SENT state, and mark socket as connecting.
624  * Start keep-alive timer, and seed output sequence space.
625  * Send initial segment on connection.
626  */
627 int
tcp_connect(struct socket * so,struct mbuf * nam)628 tcp_connect(struct socket *so, struct mbuf *nam)
629 {
630 	struct inpcb *inp;
631 	struct tcpcb *tp, *otp = NULL;
632 	int error;
633 	short ostate;
634 
635 	soassertlocked(so);
636 
637 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
638 		return (error);
639 
640 	if (so->so_options & SO_DEBUG) {
641 		otp = tp;
642 		ostate = tp->t_state;
643 	}
644 
645 #ifdef INET6
646 	if (ISSET(inp->inp_flags, INP_IPV6)) {
647 		struct sockaddr_in6 *sin6;
648 
649 		if ((error = in6_nam2sin6(nam, &sin6)))
650 			goto out;
651 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr) ||
652 		    IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
653 			error = EINVAL;
654 			goto out;
655 		}
656 	} else
657 #endif
658 	{
659 		struct sockaddr_in *sin;
660 
661 		if ((error = in_nam2sin(nam, &sin)))
662 			goto out;
663 		if ((sin->sin_addr.s_addr == INADDR_ANY) ||
664 		    (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
665 		    IN_MULTICAST(sin->sin_addr.s_addr) ||
666 		    in_broadcast(sin->sin_addr, inp->inp_rtableid)) {
667 			error = EINVAL;
668 			goto out;
669 		}
670 	}
671 	error = in_pcbconnect(inp, nam);
672 	if (error)
673 		goto out;
674 
675 	tp->t_template = tcp_template(tp);
676 	if (tp->t_template == 0) {
677 		in_pcbunset_faddr(inp);
678 		in_pcbdisconnect(inp);
679 		error = ENOBUFS;
680 		goto out;
681 	}
682 
683 	so->so_state |= SS_CONNECTOUT;
684 
685 	/* Compute window scaling to request.  */
686 	tcp_rscale(tp, sb_max);
687 
688 	soisconnecting(so);
689 	tcpstat_inc(tcps_connattempt);
690 	tp->t_state = TCPS_SYN_SENT;
691 	TCP_TIMER_ARM(tp, TCPT_KEEP, atomic_load_int(&tcp_keepinit));
692 	tcp_set_iss_tsm(tp);
693 	tcp_sendseqinit(tp);
694 	tp->snd_last = tp->snd_una;
695 	error = tcp_output(tp);
696 
697 out:
698 	if (otp)
699 		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_CONNECT, 0);
700 	return (error);
701 }
702 
703 /*
704  * Accept a connection.  Essentially all the work is done at higher
705  * levels; just return the address of the peer, storing through addr.
706  */
707 int
tcp_accept(struct socket * so,struct mbuf * nam)708 tcp_accept(struct socket *so, struct mbuf *nam)
709 {
710 	struct inpcb *inp;
711 	struct tcpcb *tp;
712 	int error;
713 
714 	soassertlocked(so);
715 
716 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
717 		return (error);
718 
719 	in_setpeeraddr(inp, nam);
720 
721 	if (so->so_options & SO_DEBUG)
722 		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL, PRU_ACCEPT, 0);
723 	return (0);
724 }
725 
726 /*
727  * Initiate disconnect from peer.
728  * If connection never passed embryonic stage, just drop;
729  * else if don't need to let data drain, then can just drop anyways,
730  * else have to begin TCP shutdown process: mark socket disconnecting,
731  * drain unread data, state switch to reflect user close, and
732  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
733  * when peer sends FIN and acks ours.
734  *
735  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
736  */
737 int
tcp_disconnect(struct socket * so)738 tcp_disconnect(struct socket *so)
739 {
740 	struct inpcb *inp;
741 	struct tcpcb *tp, *otp = NULL;
742 	int error;
743 	short ostate;
744 
745 	soassertlocked(so);
746 
747 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
748 		return (error);
749 
750 	if (so->so_options & SO_DEBUG) {
751 		otp = tp;
752 		ostate = tp->t_state;
753 	}
754 
755 	tp = tcp_dodisconnect(tp);
756 
757 	if (otp)
758 		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_DISCONNECT, 0);
759 	return (0);
760 }
761 
762 /*
763  * Mark the connection as being incapable of further output.
764  */
765 int
tcp_shutdown(struct socket * so)766 tcp_shutdown(struct socket *so)
767 {
768 	struct inpcb *inp;
769 	struct tcpcb *tp, *otp = NULL;
770 	int error;
771 	short ostate;
772 
773 	soassertlocked(so);
774 
775 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
776 		return (error);
777 
778 	if (so->so_options & SO_DEBUG) {
779 		otp = tp;
780 		ostate = tp->t_state;
781 	}
782 
783 	if (so->so_snd.sb_state & SS_CANTSENDMORE)
784 		goto out;
785 
786 	socantsendmore(so);
787 	tp = tcp_usrclosed(tp);
788 	if (tp)
789 		error = tcp_output(tp);
790 
791 out:
792 	if (otp)
793 		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_SHUTDOWN, 0);
794 	return (error);
795 }
796 
797 /*
798  * After a receive, possibly send window update to peer.
799  */
800 void
tcp_rcvd(struct socket * so)801 tcp_rcvd(struct socket *so)
802 {
803 	struct inpcb *inp;
804 	struct tcpcb *tp;
805 	short ostate;
806 
807 	soassertlocked(so);
808 
809 	if (tcp_sogetpcb(so, &inp, &tp))
810 		return;
811 
812 	if (so->so_options & SO_DEBUG)
813 		ostate = tp->t_state;
814 
815 	/*
816 	 * soreceive() calls this function when a user receives
817 	 * ancillary data on a listening socket. We don't call
818 	 * tcp_output in such a case, since there is no header
819 	 * template for a listening socket and hence the kernel
820 	 * will panic.
821 	 */
822 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) != 0)
823 		(void) tcp_output(tp);
824 
825 	if (so->so_options & SO_DEBUG)
826 		tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_RCVD, 0);
827 }
828 
829 /*
830  * Do a send by putting data in output queue and updating urgent
831  * marker if URG set.  Possibly send more data.
832  */
833 int
tcp_send(struct socket * so,struct mbuf * m,struct mbuf * nam,struct mbuf * control)834 tcp_send(struct socket *so, struct mbuf *m, struct mbuf *nam,
835     struct mbuf *control)
836 {
837 	struct inpcb *inp;
838 	struct tcpcb *tp;
839 	int error;
840 	short ostate;
841 
842 	soassertlocked(so);
843 
844 	if (control && control->m_len) {
845 		error = EINVAL;
846 		goto out;
847 	}
848 
849 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
850 		goto out;
851 
852 	if (so->so_options & SO_DEBUG)
853 		ostate = tp->t_state;
854 
855 	mtx_enter(&so->so_snd.sb_mtx);
856 	sbappendstream(so, &so->so_snd, m);
857 	mtx_leave(&so->so_snd.sb_mtx);
858 	m = NULL;
859 
860 	error = tcp_output(tp);
861 
862 	if (so->so_options & SO_DEBUG)
863 		tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_SEND, 0);
864 
865 out:
866 	m_freem(control);
867 	m_freem(m);
868 
869 	return (error);
870 }
871 
872 /*
873  * Abort the TCP.
874  */
875 void
tcp_abort(struct socket * so)876 tcp_abort(struct socket *so)
877 {
878 	struct inpcb *inp;
879 	struct tcpcb *tp, *otp = NULL;
880 	short ostate;
881 
882 	soassertlocked(so);
883 
884 	if (tcp_sogetpcb(so, &inp, &tp))
885 		return;
886 
887 	if (so->so_options & SO_DEBUG) {
888 		otp = tp;
889 		ostate = tp->t_state;
890 	}
891 
892 	tp = tcp_drop(tp, ECONNABORTED);
893 
894 	if (otp)
895 		tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_ABORT, 0);
896 }
897 
898 int
tcp_sense(struct socket * so,struct stat * ub)899 tcp_sense(struct socket *so, struct stat *ub)
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 	mtx_enter(&so->so_snd.sb_mtx);
911 	ub->st_blksize = so->so_snd.sb_hiwat;
912 	mtx_leave(&so->so_snd.sb_mtx);
913 
914 	if (so->so_options & SO_DEBUG)
915 		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL, PRU_SENSE, 0);
916 	return (0);
917 }
918 
919 int
tcp_rcvoob(struct socket * so,struct mbuf * m,int flags)920 tcp_rcvoob(struct socket *so, struct mbuf *m, int flags)
921 {
922 	struct inpcb *inp;
923 	struct tcpcb *tp;
924 	int error;
925 
926 	soassertlocked(so);
927 
928 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
929 		return (error);
930 
931 	if ((so->so_oobmark == 0 &&
932 	    (so->so_rcv.sb_state & SS_RCVATMARK) == 0) ||
933 	    so->so_options & SO_OOBINLINE ||
934 	    tp->t_oobflags & TCPOOB_HADDATA) {
935 		error = EINVAL;
936 		goto out;
937 	}
938 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
939 		error = EWOULDBLOCK;
940 		goto out;
941 	}
942 	m->m_len = 1;
943 	*mtod(m, caddr_t) = tp->t_iobc;
944 	if ((flags & MSG_PEEK) == 0)
945 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
946 out:
947 	if (so->so_options & SO_DEBUG)
948 		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL, PRU_RCVOOB, 0);
949 	return (error);
950 }
951 
952 int
tcp_sendoob(struct socket * so,struct mbuf * m,struct mbuf * nam,struct mbuf * control)953 tcp_sendoob(struct socket *so, struct mbuf *m, struct mbuf *nam,
954     struct mbuf *control)
955 {
956 	struct inpcb *inp;
957 	struct tcpcb *tp;
958 	int error;
959 	short ostate;
960 
961 	soassertlocked(so);
962 
963 	if (control && control->m_len) {
964 		error = EINVAL;
965 		goto release;
966 	}
967 
968 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
969 		goto release;
970 
971 	if (so->so_options & SO_DEBUG)
972 		ostate = tp->t_state;
973 
974 	if (sbspace(so, &so->so_snd) < -512) {
975 		error = ENOBUFS;
976 		goto out;
977 	}
978 
979 	/*
980 	 * According to RFC961 (Assigned Protocols),
981 	 * the urgent pointer points to the last octet
982 	 * of urgent data.  We continue, however,
983 	 * to consider it to indicate the first octet
984 	 * of data past the urgent section.
985 	 * Otherwise, snd_up should be one lower.
986 	 */
987 	mtx_enter(&so->so_snd.sb_mtx);
988 	sbappendstream(so, &so->so_snd, m);
989 	mtx_leave(&so->so_snd.sb_mtx);
990 	m = NULL;
991 	tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
992 	tp->t_force = 1;
993 	error = tcp_output(tp);
994 	tp->t_force = 0;
995 
996 out:
997 	if (so->so_options & SO_DEBUG)
998 		tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_SENDOOB, 0);
999 
1000 release:
1001 	m_freem(control);
1002 	m_freem(m);
1003 
1004 	return (error);
1005 }
1006 
1007 int
tcp_sockaddr(struct socket * so,struct mbuf * nam)1008 tcp_sockaddr(struct socket *so, struct mbuf *nam)
1009 {
1010 	struct inpcb *inp;
1011 	struct tcpcb *tp;
1012 	int error;
1013 
1014 	soassertlocked(so);
1015 
1016 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
1017 		return (error);
1018 
1019 	in_setsockaddr(inp, nam);
1020 
1021 	if (so->so_options & SO_DEBUG)
1022 		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL,
1023 		    PRU_SOCKADDR, 0);
1024 	return (0);
1025 }
1026 
1027 int
tcp_peeraddr(struct socket * so,struct mbuf * nam)1028 tcp_peeraddr(struct socket *so, struct mbuf *nam)
1029 {
1030 	struct inpcb *inp;
1031 	struct tcpcb *tp;
1032 	int error;
1033 
1034 	soassertlocked(so);
1035 
1036 	if ((error = tcp_sogetpcb(so, &inp, &tp)))
1037 		return (error);
1038 
1039 	in_setpeeraddr(inp, nam);
1040 
1041 	if (so->so_options & SO_DEBUG)
1042 		tcp_trace(TA_USER, tp->t_state, tp, tp, NULL, PRU_PEERADDR, 0);
1043 	return (0);
1044 }
1045 
1046 /*
1047  * Initiate (or continue) disconnect.
1048  * If embryonic state, just send reset (once).
1049  * If in ``let data drain'' option and linger null, just drop.
1050  * Otherwise (hard), mark socket disconnecting and drop
1051  * current input data; switch states based on user close, and
1052  * send segment to peer (with FIN).
1053  */
1054 struct tcpcb *
tcp_dodisconnect(struct tcpcb * tp)1055 tcp_dodisconnect(struct tcpcb *tp)
1056 {
1057 	struct socket *so = tp->t_inpcb->inp_socket;
1058 
1059 	if (TCPS_HAVEESTABLISHED(tp->t_state) == 0)
1060 		tp = tcp_close(tp);
1061 	else if ((so->so_options & SO_LINGER) && so->so_linger == 0)
1062 		tp = tcp_drop(tp, 0);
1063 	else {
1064 		soisdisconnecting(so);
1065 		mtx_enter(&so->so_rcv.sb_mtx);
1066 		sbflush(so, &so->so_rcv);
1067 		mtx_leave(&so->so_rcv.sb_mtx);
1068 		tp = tcp_usrclosed(tp);
1069 		if (tp)
1070 			(void) tcp_output(tp);
1071 	}
1072 	return (tp);
1073 }
1074 
1075 /*
1076  * User issued close, and wish to trail through shutdown states:
1077  * if never received SYN, just forget it.  If got a SYN from peer,
1078  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1079  * If already got a FIN from peer, then almost done; go to LAST_ACK
1080  * state.  In all other cases, have already sent FIN to peer (e.g.
1081  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1082  * for peer to send FIN or not respond to keep-alives, etc.
1083  * We can let the user exit from the close as soon as the FIN is acked.
1084  */
1085 struct tcpcb *
tcp_usrclosed(struct tcpcb * tp)1086 tcp_usrclosed(struct tcpcb *tp)
1087 {
1088 
1089 	switch (tp->t_state) {
1090 
1091 	case TCPS_CLOSED:
1092 	case TCPS_LISTEN:
1093 	case TCPS_SYN_SENT:
1094 		tp->t_state = TCPS_CLOSED;
1095 		tp = tcp_close(tp);
1096 		break;
1097 
1098 	case TCPS_SYN_RECEIVED:
1099 	case TCPS_ESTABLISHED:
1100 		tp->t_state = TCPS_FIN_WAIT_1;
1101 		break;
1102 
1103 	case TCPS_CLOSE_WAIT:
1104 		tp->t_state = TCPS_LAST_ACK;
1105 		break;
1106 	}
1107 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1108 		soisdisconnected(tp->t_inpcb->inp_socket);
1109 		/*
1110 		 * If we are in FIN_WAIT_2, we arrived here because the
1111 		 * application did a shutdown of the send side.  Like the
1112 		 * case of a transition from FIN_WAIT_1 to FIN_WAIT_2 after
1113 		 * a full close, we start a timer to make sure sockets are
1114 		 * not left in FIN_WAIT_2 forever.
1115 		 */
1116 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1117 			int maxidle;
1118 
1119 			maxidle = TCPTV_KEEPCNT *
1120 			    atomic_load_int(&tcp_keepidle);
1121 			TCP_TIMER_ARM(tp, TCPT_2MSL, maxidle);
1122 		}
1123 	}
1124 	return (tp);
1125 }
1126 
1127 /*
1128  * Look up a socket for ident or tcpdrop, ...
1129  */
1130 int
tcp_ident(void * oldp,size_t * oldlenp,void * newp,size_t newlen,int dodrop)1131 tcp_ident(void *oldp, size_t *oldlenp, void *newp, size_t newlen, int dodrop)
1132 {
1133 	int error = 0;
1134 	struct tcp_ident_mapping tir;
1135 	struct inpcb *inp;
1136 	struct socket *so = NULL;
1137 	struct sockaddr_in *fin, *lin;
1138 #ifdef INET6
1139 	struct sockaddr_in6 *fin6, *lin6;
1140 	struct in6_addr f6, l6;
1141 #endif
1142 
1143 	if (dodrop) {
1144 		if (oldp != NULL || *oldlenp != 0)
1145 			return (EINVAL);
1146 		if (newp == NULL)
1147 			return (EPERM);
1148 		if (newlen < sizeof(tir))
1149 			return (ENOMEM);
1150 		if ((error = copyin(newp, &tir, sizeof (tir))) != 0 )
1151 			return (error);
1152 	} else {
1153 		if (oldp == NULL)
1154 			return (EINVAL);
1155 		if (*oldlenp < sizeof(tir))
1156 			return (ENOMEM);
1157 		if (newp != NULL || newlen != 0)
1158 			return (EINVAL);
1159 		if ((error = copyin(oldp, &tir, sizeof (tir))) != 0 )
1160 			return (error);
1161 	}
1162 
1163 	NET_LOCK_SHARED();
1164 
1165 	switch (tir.faddr.ss_family) {
1166 #ifdef INET6
1167 	case AF_INET6:
1168 		if (tir.laddr.ss_family != AF_INET6) {
1169 			NET_UNLOCK_SHARED();
1170 			return (EAFNOSUPPORT);
1171 		}
1172 		fin6 = (struct sockaddr_in6 *)&tir.faddr;
1173 		error = in6_embedscope(&f6, fin6, NULL, NULL);
1174 		if (error) {
1175 			NET_UNLOCK_SHARED();
1176 			return EINVAL;	/*?*/
1177 		}
1178 		lin6 = (struct sockaddr_in6 *)&tir.laddr;
1179 		error = in6_embedscope(&l6, lin6, NULL, NULL);
1180 		if (error) {
1181 			NET_UNLOCK_SHARED();
1182 			return EINVAL;	/*?*/
1183 		}
1184 		break;
1185 #endif
1186 	case AF_INET:
1187 		if (tir.laddr.ss_family != AF_INET) {
1188 			NET_UNLOCK_SHARED();
1189 			return (EAFNOSUPPORT);
1190 		}
1191 		fin = (struct sockaddr_in *)&tir.faddr;
1192 		lin = (struct sockaddr_in *)&tir.laddr;
1193 		break;
1194 	default:
1195 		NET_UNLOCK_SHARED();
1196 		return (EAFNOSUPPORT);
1197 	}
1198 
1199 	switch (tir.faddr.ss_family) {
1200 #ifdef INET6
1201 	case AF_INET6:
1202 		inp = in6_pcblookup(&tcb6table, &f6,
1203 		    fin6->sin6_port, &l6, lin6->sin6_port, tir.rdomain);
1204 		break;
1205 #endif
1206 	case AF_INET:
1207 		inp = in_pcblookup(&tcbtable, fin->sin_addr,
1208 		    fin->sin_port, lin->sin_addr, lin->sin_port, tir.rdomain);
1209 		break;
1210 	default:
1211 		unhandled_af(tir.faddr.ss_family);
1212 	}
1213 
1214 	if (dodrop) {
1215 		struct tcpcb *tp = NULL;
1216 
1217 		if (inp != NULL) {
1218 			so = in_pcbsolock_ref(inp);
1219 			if (so != NULL)
1220 				tp = intotcpcb(inp);
1221 		}
1222 		if (tp != NULL && !ISSET(so->so_options, SO_ACCEPTCONN))
1223 			tp = tcp_drop(tp, ECONNABORTED);
1224 		else
1225 			error = ESRCH;
1226 
1227 		in_pcbsounlock_rele(inp, so);
1228 		NET_UNLOCK_SHARED();
1229 		in_pcbunref(inp);
1230 		return (error);
1231 	}
1232 
1233 	if (inp == NULL) {
1234 		tcpstat_inc(tcps_pcbhashmiss);
1235 		switch (tir.faddr.ss_family) {
1236 #ifdef INET6
1237 		case AF_INET6:
1238 			inp = in6_pcblookup_listen(&tcb6table,
1239 			    &l6, lin6->sin6_port, NULL, tir.rdomain);
1240 			break;
1241 #endif
1242 		case AF_INET:
1243 			inp = in_pcblookup_listen(&tcbtable,
1244 			    lin->sin_addr, lin->sin_port, NULL, tir.rdomain);
1245 			break;
1246 		}
1247 	}
1248 
1249 	if (inp != NULL)
1250 		so = in_pcbsolock_ref(inp);
1251 
1252 	if (so != NULL && ISSET(so->so_state, SS_CONNECTOUT)) {
1253 		tir.ruid = so->so_ruid;
1254 		tir.euid = so->so_euid;
1255 	} else {
1256 		tir.ruid = -1;
1257 		tir.euid = -1;
1258 	}
1259 
1260 	in_pcbsounlock_rele(inp, so);
1261 	NET_UNLOCK_SHARED();
1262 	in_pcbunref(inp);
1263 
1264 	*oldlenp = sizeof(tir);
1265 	return copyout(&tir, oldp, sizeof(tir));
1266 }
1267 
1268 int
tcp_sysctl_tcpstat(void * oldp,size_t * oldlenp,void * newp)1269 tcp_sysctl_tcpstat(void *oldp, size_t *oldlenp, void *newp)
1270 {
1271 	uint64_t counters[tcps_ncounters];
1272 	struct tcpstat tcpstat;
1273 	struct syn_cache_set *set;
1274 	int i = 0;
1275 
1276 #define ASSIGN(field)	do { tcpstat.field = counters[i++]; } while (0)
1277 
1278 	memset(&tcpstat, 0, sizeof tcpstat);
1279 	counters_read(tcpcounters, counters, nitems(counters), NULL);
1280 	ASSIGN(tcps_connattempt);
1281 	ASSIGN(tcps_accepts);
1282 	ASSIGN(tcps_connects);
1283 	ASSIGN(tcps_drops);
1284 	ASSIGN(tcps_conndrops);
1285 	ASSIGN(tcps_closed);
1286 	ASSIGN(tcps_segstimed);
1287 	ASSIGN(tcps_rttupdated);
1288 	ASSIGN(tcps_delack);
1289 	ASSIGN(tcps_timeoutdrop);
1290 	ASSIGN(tcps_rexmttimeo);
1291 	ASSIGN(tcps_persisttimeo);
1292 	ASSIGN(tcps_persistdrop);
1293 	ASSIGN(tcps_keeptimeo);
1294 	ASSIGN(tcps_keepprobe);
1295 	ASSIGN(tcps_keepdrops);
1296 	ASSIGN(tcps_sndtotal);
1297 	ASSIGN(tcps_sndpack);
1298 	ASSIGN(tcps_sndbyte);
1299 	ASSIGN(tcps_sndrexmitpack);
1300 	ASSIGN(tcps_sndrexmitbyte);
1301 	ASSIGN(tcps_sndrexmitfast);
1302 	ASSIGN(tcps_sndacks);
1303 	ASSIGN(tcps_sndprobe);
1304 	ASSIGN(tcps_sndurg);
1305 	ASSIGN(tcps_sndwinup);
1306 	ASSIGN(tcps_sndctrl);
1307 	ASSIGN(tcps_rcvtotal);
1308 	ASSIGN(tcps_rcvpack);
1309 	ASSIGN(tcps_rcvbyte);
1310 	ASSIGN(tcps_rcvbadsum);
1311 	ASSIGN(tcps_rcvbadoff);
1312 	ASSIGN(tcps_rcvmemdrop);
1313 	ASSIGN(tcps_rcvnosec);
1314 	ASSIGN(tcps_rcvshort);
1315 	ASSIGN(tcps_rcvduppack);
1316 	ASSIGN(tcps_rcvdupbyte);
1317 	ASSIGN(tcps_rcvpartduppack);
1318 	ASSIGN(tcps_rcvpartdupbyte);
1319 	ASSIGN(tcps_rcvoopack);
1320 	ASSIGN(tcps_rcvoobyte);
1321 	ASSIGN(tcps_rcvpackafterwin);
1322 	ASSIGN(tcps_rcvbyteafterwin);
1323 	ASSIGN(tcps_rcvafterclose);
1324 	ASSIGN(tcps_rcvwinprobe);
1325 	ASSIGN(tcps_rcvdupack);
1326 	ASSIGN(tcps_rcvacktoomuch);
1327 	ASSIGN(tcps_rcvacktooold);
1328 	ASSIGN(tcps_rcvackpack);
1329 	ASSIGN(tcps_rcvackbyte);
1330 	ASSIGN(tcps_rcvwinupd);
1331 	ASSIGN(tcps_pawsdrop);
1332 	ASSIGN(tcps_predack);
1333 	ASSIGN(tcps_preddat);
1334 	ASSIGN(tcps_pcbhashmiss);
1335 	ASSIGN(tcps_noport);
1336 	ASSIGN(tcps_badsyn);
1337 	ASSIGN(tcps_dropsyn);
1338 	ASSIGN(tcps_rcvbadsig);
1339 	ASSIGN(tcps_rcvgoodsig);
1340 	ASSIGN(tcps_inswcsum);
1341 	ASSIGN(tcps_outswcsum);
1342 	ASSIGN(tcps_ecn_accepts);
1343 	ASSIGN(tcps_ecn_rcvece);
1344 	ASSIGN(tcps_ecn_rcvcwr);
1345 	ASSIGN(tcps_ecn_rcvce);
1346 	ASSIGN(tcps_ecn_sndect);
1347 	ASSIGN(tcps_ecn_sndece);
1348 	ASSIGN(tcps_ecn_sndcwr);
1349 	ASSIGN(tcps_cwr_ecn);
1350 	ASSIGN(tcps_cwr_frecovery);
1351 	ASSIGN(tcps_cwr_timeout);
1352 	ASSIGN(tcps_sc_added);
1353 	ASSIGN(tcps_sc_completed);
1354 	ASSIGN(tcps_sc_timed_out);
1355 	ASSIGN(tcps_sc_overflowed);
1356 	ASSIGN(tcps_sc_reset);
1357 	ASSIGN(tcps_sc_unreach);
1358 	ASSIGN(tcps_sc_bucketoverflow);
1359 	ASSIGN(tcps_sc_aborted);
1360 	ASSIGN(tcps_sc_dupesyn);
1361 	ASSIGN(tcps_sc_dropped);
1362 	ASSIGN(tcps_sc_collisions);
1363 	ASSIGN(tcps_sc_retransmitted);
1364 	ASSIGN(tcps_sc_seedrandom);
1365 	ASSIGN(tcps_sc_hash_size);
1366 	ASSIGN(tcps_sc_entry_count);
1367 	ASSIGN(tcps_sc_entry_limit);
1368 	ASSIGN(tcps_sc_bucket_maxlen);
1369 	ASSIGN(tcps_sc_bucket_limit);
1370 	ASSIGN(tcps_sc_uses_left);
1371 	ASSIGN(tcps_conndrained);
1372 	ASSIGN(tcps_sack_recovery_episode);
1373 	ASSIGN(tcps_sack_rexmits);
1374 	ASSIGN(tcps_sack_rexmit_bytes);
1375 	ASSIGN(tcps_sack_rcv_opts);
1376 	ASSIGN(tcps_sack_snd_opts);
1377 	ASSIGN(tcps_sack_drop_opts);
1378 	ASSIGN(tcps_outswtso);
1379 	ASSIGN(tcps_outhwtso);
1380 	ASSIGN(tcps_outpkttso);
1381 	ASSIGN(tcps_outbadtso);
1382 	ASSIGN(tcps_inswlro);
1383 	ASSIGN(tcps_inhwlro);
1384 	ASSIGN(tcps_inpktlro);
1385 	ASSIGN(tcps_inbadlro);
1386 
1387 #undef ASSIGN
1388 
1389 	mtx_enter(&syn_cache_mtx);
1390 	set = &tcp_syn_cache[tcp_syn_cache_active];
1391 	tcpstat.tcps_sc_hash_size = set->scs_size;
1392 	tcpstat.tcps_sc_entry_count = set->scs_count;
1393 	tcpstat.tcps_sc_entry_limit = atomic_load_int(&tcp_syn_cache_limit);
1394 	tcpstat.tcps_sc_bucket_maxlen = 0;
1395 	for (i = 0; i < set->scs_size; i++) {
1396 		if (tcpstat.tcps_sc_bucket_maxlen <
1397 		    set->scs_buckethead[i].sch_length)
1398 			tcpstat.tcps_sc_bucket_maxlen =
1399 				set->scs_buckethead[i].sch_length;
1400 	}
1401 	tcpstat.tcps_sc_bucket_limit = atomic_load_int(&tcp_syn_bucket_limit);
1402 	tcpstat.tcps_sc_uses_left = set->scs_use;
1403 	mtx_leave(&syn_cache_mtx);
1404 
1405 	return (sysctl_rdstruct(oldp, oldlenp, newp,
1406 	    &tcpstat, sizeof(tcpstat)));
1407 }
1408 
1409 /*
1410  * Sysctl for tcp variables.
1411  */
1412 int
tcp_sysctl(int * name,u_int namelen,void * oldp,size_t * oldlenp,void * newp,size_t newlen)1413 tcp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
1414     size_t newlen)
1415 {
1416 	int error, oval, nval;
1417 
1418 	/* All sysctl names at this level are terminal. */
1419 	if (namelen != 1)
1420 		return (ENOTDIR);
1421 
1422 	switch (name[0]) {
1423 	case TCPCTL_BADDYNAMIC:
1424 		NET_LOCK();
1425 		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1426 		    baddynamicports.tcp, sizeof(baddynamicports.tcp));
1427 		NET_UNLOCK();
1428 		return (error);
1429 
1430 	case TCPCTL_ROOTONLY:
1431 		if (newp && securelevel > 0)
1432 			return (EPERM);
1433 		NET_LOCK();
1434 		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1435 		    rootonlyports.tcp, sizeof(rootonlyports.tcp));
1436 		NET_UNLOCK();
1437 		return (error);
1438 
1439 	case TCPCTL_IDENT:
1440 		return tcp_ident(oldp, oldlenp, newp, newlen, 0);
1441 
1442 	case TCPCTL_DROP:
1443 		return tcp_ident(oldp, oldlenp, newp, newlen, 1);
1444 
1445 	case TCPCTL_REASS_LIMIT:
1446 		NET_LOCK();
1447 		nval = tcp_reass_limit;
1448 		error = sysctl_int(oldp, oldlenp, newp, newlen, &nval);
1449 		if (!error && nval != tcp_reass_limit) {
1450 			error = pool_sethardlimit(&tcpqe_pool, nval, NULL, 0);
1451 			if (!error)
1452 				tcp_reass_limit = nval;
1453 		}
1454 		NET_UNLOCK();
1455 		return (error);
1456 
1457 	case TCPCTL_SACKHOLE_LIMIT:
1458 		NET_LOCK();
1459 		nval = tcp_sackhole_limit;
1460 		error = sysctl_int(oldp, oldlenp, newp, newlen, &nval);
1461 		if (!error && nval != tcp_sackhole_limit) {
1462 			error = pool_sethardlimit(&sackhl_pool, nval, NULL, 0);
1463 			if (!error)
1464 				tcp_sackhole_limit = nval;
1465 		}
1466 		NET_UNLOCK();
1467 		return (error);
1468 
1469 	case TCPCTL_STATS:
1470 		return (tcp_sysctl_tcpstat(oldp, oldlenp, newp));
1471 
1472 	case TCPCTL_SYN_USE_LIMIT:
1473 		oval = nval = atomic_load_int(&tcp_syn_use_limit);
1474 		error = sysctl_int_bounded(oldp, oldlenp, newp, newlen,
1475 		    &nval, 0, INT_MAX);
1476 		if (!error && oval != nval) {
1477 			/*
1478 			 * Global tcp_syn_use_limit is used when reseeding a
1479 			 * new cache.  Also update the value in active cache.
1480 			 */
1481 			mtx_enter(&syn_cache_mtx);
1482 			if (tcp_syn_cache[0].scs_use > nval)
1483 				tcp_syn_cache[0].scs_use = nval;
1484 			if (tcp_syn_cache[1].scs_use > nval)
1485 				tcp_syn_cache[1].scs_use = nval;
1486 			tcp_syn_use_limit = nval;
1487 			mtx_leave(&syn_cache_mtx);
1488 		}
1489 		return (error);
1490 
1491 	case TCPCTL_SYN_HASH_SIZE:
1492 		oval = nval = atomic_load_int(&tcp_syn_hash_size);
1493 		error = sysctl_int_bounded(oldp, oldlenp, newp, newlen,
1494 		    &nval, 1, 100000);
1495 		if (!error && oval != nval) {
1496 			/*
1497 			 * If global hash size has been changed,
1498 			 * switch sets as soon as possible.  Then
1499 			 * the actual hash array will be reallocated.
1500 			 */
1501 			mtx_enter(&syn_cache_mtx);
1502 			if (tcp_syn_cache[0].scs_size != nval)
1503 				tcp_syn_cache[0].scs_use = 0;
1504 			if (tcp_syn_cache[1].scs_size != nval)
1505 				tcp_syn_cache[1].scs_use = 0;
1506 			tcp_syn_hash_size = nval;
1507 			mtx_leave(&syn_cache_mtx);
1508 		}
1509 		return (error);
1510 
1511 	default:
1512 		error = sysctl_bounded_arr(tcpctl_vars, nitems(tcpctl_vars),
1513 		    name, namelen, oldp, oldlenp, newp, newlen);
1514 		switch (name[0]) {
1515 		case TCPCTL_KEEPINITTIME:
1516 			atomic_store_int(&tcp_keepinit,
1517 			    atomic_load_int(&tcp_keepinit_sec) * TCP_TIME(1));
1518 			break;
1519 		case TCPCTL_KEEPIDLE:
1520 			atomic_store_int(&tcp_keepidle,
1521 			    atomic_load_int(&tcp_keepidle_sec) * TCP_TIME(1));
1522 			break;
1523 		case TCPCTL_KEEPINTVL:
1524 			atomic_store_int(&tcp_keepintvl,
1525 			    atomic_load_int(&tcp_keepintvl_sec) * TCP_TIME(1));
1526 			break;
1527 		}
1528 		return (error);
1529 	}
1530 	/* NOTREACHED */
1531 }
1532 
1533 /*
1534  * Scale the send buffer so that inflight data is not accounted against
1535  * the limit. The buffer will scale with the congestion window, if the
1536  * the receiver stops acking data the window will shrink and therefore
1537  * the buffer size will shrink as well.
1538  * In low memory situation try to shrink the buffer to the initial size
1539  * disabling the send buffer scaling as long as the situation persists.
1540  */
1541 void
tcp_update_sndspace(struct tcpcb * tp)1542 tcp_update_sndspace(struct tcpcb *tp)
1543 {
1544 	struct socket *so = tp->t_inpcb->inp_socket;
1545 	u_long nmax;
1546 
1547 	mtx_enter(&so->so_snd.sb_mtx);
1548 
1549 	nmax = so->so_snd.sb_hiwat;
1550 
1551 	if (sbchecklowmem()) {
1552 		/* low on memory try to get rid of some */
1553 		if (tcp_sendspace < nmax)
1554 			nmax = tcp_sendspace;
1555 	} else if (so->so_snd.sb_wat != tcp_sendspace) {
1556 		/* user requested buffer size, auto-scaling disabled */
1557 		nmax = so->so_snd.sb_wat;
1558 	} else {
1559 		/* automatic buffer scaling */
1560 		nmax = MIN(sb_max, so->so_snd.sb_wat + tp->snd_max -
1561 		    tp->snd_una);
1562 	}
1563 
1564 	/* a writable socket must be preserved because of poll(2) semantics */
1565 	if (sbspace_locked(so, &so->so_snd) >= so->so_snd.sb_lowat) {
1566 		if (nmax < so->so_snd.sb_cc + so->so_snd.sb_lowat)
1567 			nmax = so->so_snd.sb_cc + so->so_snd.sb_lowat;
1568 		/* keep in sync with sbreserve() calculation */
1569 		if (nmax * 8 < so->so_snd.sb_mbcnt + so->so_snd.sb_lowat)
1570 			nmax = (so->so_snd.sb_mbcnt+so->so_snd.sb_lowat+7) / 8;
1571 	}
1572 
1573 	/* round to MSS boundary */
1574 	nmax = roundup(nmax, tp->t_maxseg);
1575 
1576 	if (nmax != so->so_snd.sb_hiwat)
1577 		sbreserve(so, &so->so_snd, nmax);
1578 
1579 	mtx_leave(&so->so_snd.sb_mtx);
1580 }
1581 
1582 /*
1583  * Scale the recv buffer by looking at how much data was transferred in
1584  * one approximated RTT. If more than a big part of the recv buffer was
1585  * transferred during that time we increase the buffer by a constant.
1586  * In low memory situation try to shrink the buffer to the initial size.
1587  */
1588 void
tcp_update_rcvspace(struct tcpcb * tp)1589 tcp_update_rcvspace(struct tcpcb *tp)
1590 {
1591 	struct socket *so = tp->t_inpcb->inp_socket;
1592 	u_long nmax;
1593 
1594 	mtx_enter(&so->so_rcv.sb_mtx);
1595 
1596 	nmax = so->so_rcv.sb_hiwat;
1597 
1598 	if (sbchecklowmem()) {
1599 		/* low on memory try to get rid of some */
1600 		if (tcp_recvspace < nmax)
1601 			nmax = tcp_recvspace;
1602 	} else if (so->so_rcv.sb_wat != tcp_recvspace) {
1603 		/* user requested buffer size, auto-scaling disabled */
1604 		nmax = so->so_rcv.sb_wat;
1605 	} else {
1606 		/* automatic buffer scaling */
1607 		if (tp->rfbuf_cnt > so->so_rcv.sb_hiwat / 8 * 7)
1608 			nmax = MIN(sb_max, so->so_rcv.sb_hiwat +
1609 			    tcp_autorcvbuf_inc);
1610 	}
1611 
1612 	/* a readable socket must be preserved because of poll(2) semantics */
1613 	mtx_enter(&so->so_snd.sb_mtx);
1614 	if (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat &&
1615 	    nmax < so->so_snd.sb_lowat)
1616 		nmax = so->so_snd.sb_lowat;
1617 	mtx_leave(&so->so_snd.sb_mtx);
1618 
1619 	if (nmax != so->so_rcv.sb_hiwat) {
1620 		/* round to MSS boundary */
1621 		nmax = roundup(nmax, tp->t_maxseg);
1622 		sbreserve(so, &so->so_rcv, nmax);
1623 	}
1624 
1625 	mtx_leave(&so->so_rcv.sb_mtx);
1626 }
1627