xref: /dflybsd-src/sys/netinet/tcp_usrreq.c (revision d1248869548dbf2758509889f99e3c706f4f8846)
1 /*
2  * Copyright (c) 2003, 2004 Jeffrey M. Hsu.  All rights reserved.
3  * Copyright (c) 2003, 2004 The DragonFly Project.  All rights reserved.
4  *
5  * This code is derived from software contributed to The DragonFly Project
6  * by Jeffrey M. Hsu.
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 DragonFly Project nor the names of its
17  *    contributors may be used to endorse or promote products derived
18  *    from this software without specific, prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1982, 1986, 1988, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *	This product includes software developed by the University of
49  *	California, Berkeley and its contributors.
50  * 4. Neither the name of the University nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64  * SUCH DAMAGE.
65  *
66  *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
67  * $FreeBSD: src/sys/netinet/tcp_usrreq.c,v 1.51.2.17 2002/10/11 11:46:44 ume Exp $
68  * $DragonFly: src/sys/netinet/tcp_usrreq.c,v 1.51 2008/09/29 20:52:23 dillon Exp $
69  */
70 
71 #include "opt_ipsec.h"
72 #include "opt_inet.h"
73 #include "opt_inet6.h"
74 #include "opt_tcpdebug.h"
75 
76 #include <sys/param.h>
77 #include <sys/systm.h>
78 #include <sys/kernel.h>
79 #include <sys/malloc.h>
80 #include <sys/sysctl.h>
81 #include <sys/globaldata.h>
82 #include <sys/thread.h>
83 
84 #include <sys/mbuf.h>
85 #ifdef INET6
86 #include <sys/domain.h>
87 #endif /* INET6 */
88 #include <sys/socket.h>
89 #include <sys/socketvar.h>
90 #include <sys/protosw.h>
91 
92 #include <sys/thread2.h>
93 #include <sys/msgport2.h>
94 #include <sys/socketvar2.h>
95 
96 #include <net/if.h>
97 #include <net/netisr.h>
98 #include <net/route.h>
99 
100 #include <net/netmsg2.h>
101 
102 #include <netinet/in.h>
103 #include <netinet/in_systm.h>
104 #ifdef INET6
105 #include <netinet/ip6.h>
106 #endif
107 #include <netinet/in_pcb.h>
108 #ifdef INET6
109 #include <netinet6/in6_pcb.h>
110 #endif
111 #include <netinet/in_var.h>
112 #include <netinet/ip_var.h>
113 #ifdef INET6
114 #include <netinet6/ip6_var.h>
115 #include <netinet6/tcp6_var.h>
116 #endif
117 #include <netinet/tcp.h>
118 #include <netinet/tcp_fsm.h>
119 #include <netinet/tcp_seq.h>
120 #include <netinet/tcp_timer.h>
121 #include <netinet/tcp_timer2.h>
122 #include <netinet/tcp_var.h>
123 #include <netinet/tcpip.h>
124 #ifdef TCPDEBUG
125 #include <netinet/tcp_debug.h>
126 #endif
127 
128 #ifdef IPSEC
129 #include <netinet6/ipsec.h>
130 #endif /*IPSEC*/
131 
132 /*
133  * TCP protocol interface to socket abstraction.
134  */
135 extern	char *tcpstates[];	/* XXX ??? */
136 
137 static int	tcp_attach (struct socket *, struct pru_attach_info *);
138 static void	tcp_connect (netmsg_t msg);
139 #ifdef INET6
140 static void	tcp6_connect (netmsg_t msg);
141 static int	tcp6_connect_oncpu(struct tcpcb *tp, int flags,
142 				struct mbuf **mp,
143 				struct sockaddr_in6 *sin6,
144 				struct in6_addr *addr6);
145 #endif /* INET6 */
146 static struct tcpcb *
147 		tcp_disconnect (struct tcpcb *);
148 static struct tcpcb *
149 		tcp_usrclosed (struct tcpcb *);
150 
151 #ifdef TCPDEBUG
152 #define	TCPDEBUG0	int ostate = 0
153 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
154 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
155 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
156 #else
157 #define	TCPDEBUG0
158 #define	TCPDEBUG1()
159 #define	TCPDEBUG2(req)
160 #endif
161 
162 static int	tcp_lport_extension = 1;
163 
164 SYSCTL_INT(_net_inet_tcp, OID_AUTO, lportext, CTLFLAG_RW,
165     &tcp_lport_extension, 0, "");
166 
167 /*
168  * TCP attaches to socket via pru_attach(), reserving space,
169  * and an internet control block.  This is likely occuring on
170  * cpu0 and may have to move later when we bind/connect.
171  */
172 static void
173 tcp_usr_attach(netmsg_t msg)
174 {
175 	struct socket *so = msg->base.nm_so;
176 	struct pru_attach_info *ai = msg->attach.nm_ai;
177 	int error;
178 	struct inpcb *inp;
179 	struct tcpcb *tp = 0;
180 	TCPDEBUG0;
181 
182 	soreference(so);
183 	inp = so->so_pcb;
184 	TCPDEBUG1();
185 	if (inp) {
186 		error = EISCONN;
187 		goto out;
188 	}
189 
190 	error = tcp_attach(so, ai);
191 	if (error)
192 		goto out;
193 
194 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
195 		so->so_linger = TCP_LINGERTIME;
196 	tp = sototcpcb(so);
197 out:
198 	sofree(so);		/* from ref above */
199 	TCPDEBUG2(PRU_ATTACH);
200 	lwkt_replymsg(&msg->lmsg, error);
201 }
202 
203 /*
204  * pru_detach() detaches the TCP protocol from the socket.
205  * If the protocol state is non-embryonic, then can't
206  * do this directly: have to initiate a pru_disconnect(),
207  * which may finish later; embryonic TCB's can just
208  * be discarded here.
209  */
210 static void
211 tcp_usr_detach(netmsg_t msg)
212 {
213 	struct socket *so = msg->base.nm_so;
214 	int error = 0;
215 	struct inpcb *inp;
216 	struct tcpcb *tp;
217 	TCPDEBUG0;
218 
219 	inp = so->so_pcb;
220 
221 	/*
222 	 * If the inp is already detached it may have been due to an async
223 	 * close.  Just return as if no error occured.
224 	 *
225 	 * It's possible for the tcpcb (tp) to disconnect from the inp due
226 	 * to tcp_drop()->tcp_close() being called.  This may occur *after*
227 	 * the detach message has been queued so we may find a NULL tp here.
228 	 */
229 	if (inp) {
230 		if ((tp = intotcpcb(inp)) != NULL) {
231 			TCPDEBUG1();
232 			tp = tcp_disconnect(tp);
233 			TCPDEBUG2(PRU_DETACH);
234 		}
235 	}
236 	lwkt_replymsg(&msg->lmsg, error);
237 }
238 
239 /*
240  * NOTE: ignore_error is non-zero for certain disconnection races
241  * which we want to silently allow, otherwise close() may return
242  * an unexpected error.
243  *
244  * NOTE: The variables (msg) and (tp) are assumed.
245  */
246 #define	COMMON_START(so, inp, ignore_error)			\
247 	TCPDEBUG0; 						\
248 								\
249 	inp = so->so_pcb; 					\
250 	do {							\
251 		 if (inp == NULL) {				\
252 			error = ignore_error ? 0 : EINVAL;	\
253 			tp = NULL;				\
254 			goto out;				\
255 		 }						\
256 		 tp = intotcpcb(inp);				\
257 		 TCPDEBUG1();					\
258 	} while(0)
259 
260 #define COMMON_END1(req, noreply)				\
261 	out: do {						\
262 		TCPDEBUG2(req);					\
263 		if (!(noreply))					\
264 			lwkt_replymsg(&msg->lmsg, error);	\
265 		return;						\
266 	} while(0)
267 
268 #define COMMON_END(req)		COMMON_END1((req), 0)
269 
270 /*
271  * Give the socket an address.
272  */
273 static void
274 tcp_usr_bind(netmsg_t msg)
275 {
276 	struct socket *so = msg->bind.base.nm_so;
277 	struct sockaddr *nam = msg->bind.nm_nam;
278 	struct thread *td = msg->bind.nm_td;
279 	int error = 0;
280 	struct inpcb *inp;
281 	struct tcpcb *tp;
282 	struct sockaddr_in *sinp;
283 
284 	COMMON_START(so, inp, 0);
285 
286 	/*
287 	 * Must check for multicast addresses and disallow binding
288 	 * to them.
289 	 */
290 	sinp = (struct sockaddr_in *)nam;
291 	if (sinp->sin_family == AF_INET &&
292 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
293 		error = EAFNOSUPPORT;
294 		goto out;
295 	}
296 	error = in_pcbbind(inp, nam, td);
297 	if (error)
298 		goto out;
299 	COMMON_END(PRU_BIND);
300 
301 }
302 
303 #ifdef INET6
304 
305 static void
306 tcp6_usr_bind(netmsg_t msg)
307 {
308 	struct socket *so = msg->bind.base.nm_so;
309 	struct sockaddr *nam = msg->bind.nm_nam;
310 	struct thread *td = msg->bind.nm_td;
311 	int error = 0;
312 	struct inpcb *inp;
313 	struct tcpcb *tp;
314 	struct sockaddr_in6 *sin6p;
315 
316 	COMMON_START(so, inp, 0);
317 
318 	/*
319 	 * Must check for multicast addresses and disallow binding
320 	 * to them.
321 	 */
322 	sin6p = (struct sockaddr_in6 *)nam;
323 	if (sin6p->sin6_family == AF_INET6 &&
324 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
325 		error = EAFNOSUPPORT;
326 		goto out;
327 	}
328 	inp->inp_vflag &= ~INP_IPV4;
329 	inp->inp_vflag |= INP_IPV6;
330 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
331 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
332 			inp->inp_vflag |= INP_IPV4;
333 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
334 			struct sockaddr_in sin;
335 
336 			in6_sin6_2_sin(&sin, sin6p);
337 			inp->inp_vflag |= INP_IPV4;
338 			inp->inp_vflag &= ~INP_IPV6;
339 			error = in_pcbbind(inp, (struct sockaddr *)&sin, td);
340 			goto out;
341 		}
342 	}
343 	error = in6_pcbbind(inp, nam, td);
344 	if (error)
345 		goto out;
346 	COMMON_END(PRU_BIND);
347 }
348 #endif /* INET6 */
349 
350 #ifdef SMP
351 
352 struct netmsg_inswildcard {
353 	struct netmsg_base	base;
354 	struct inpcb		*nm_inp;
355 };
356 
357 static void
358 in_pcbinswildcardhash_handler(netmsg_t msg)
359 {
360 	struct netmsg_inswildcard *nm = (struct netmsg_inswildcard *)msg;
361 	int cpu = mycpuid, nextcpu;
362 
363 	in_pcbinswildcardhash_oncpu(nm->nm_inp, &tcbinfo[cpu]);
364 
365 	nextcpu = cpu + 1;
366 	if (nextcpu < ncpus2)
367 		lwkt_forwardmsg(cpu_portfn(nextcpu), &nm->base.lmsg);
368 	else
369 		lwkt_replymsg(&nm->base.lmsg, 0);
370 }
371 
372 #endif
373 
374 /*
375  * Prepare to accept connections.
376  */
377 static void
378 tcp_usr_listen(netmsg_t msg)
379 {
380 	struct socket *so = msg->listen.base.nm_so;
381 	struct thread *td = msg->listen.nm_td;
382 	int error = 0;
383 	struct inpcb *inp;
384 	struct tcpcb *tp;
385 #ifdef SMP
386 	struct netmsg_inswildcard nm;
387 #endif
388 
389 	COMMON_START(so, inp, 0);
390 
391 	if (tp->t_flags & TF_LISTEN)
392 		goto out;
393 
394 	if (inp->inp_lport == 0) {
395 		error = in_pcbbind(inp, NULL, td);
396 		if (error)
397 			goto out;
398 	}
399 
400 	tp->t_state = TCPS_LISTEN;
401 	tp->t_flags |= TF_LISTEN;
402 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
403 
404 #ifdef SMP
405 	if (ncpus > 1) {
406 		/*
407 		 * We have to set the flag because we can't have other cpus
408 		 * messing with our inp's flags.
409 		 */
410 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
411 			("already on connhash\n"));
412 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
413 			("already on wildcardhash\n"));
414 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
415 			("already on MP wildcardhash\n"));
416 		inp->inp_flags |= INP_WILDCARD_MP;
417 
418 		KKASSERT(so->so_port == cpu_portfn(0));
419 		KKASSERT(&curthread->td_msgport == cpu_portfn(0));
420 		KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
421 
422 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
423 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
424 		nm.nm_inp = inp;
425 		lwkt_domsg(cpu_portfn(1), &nm.base.lmsg, 0);
426 	}
427 #endif
428 	in_pcbinswildcardhash(inp);
429 	COMMON_END(PRU_LISTEN);
430 }
431 
432 #ifdef INET6
433 
434 static void
435 tcp6_usr_listen(netmsg_t msg)
436 {
437 	struct socket *so = msg->listen.base.nm_so;
438 	struct thread *td = msg->listen.nm_td;
439 	int error = 0;
440 	struct inpcb *inp;
441 	struct tcpcb *tp;
442 #ifdef SMP
443 	struct netmsg_inswildcard nm;
444 #endif
445 
446 	COMMON_START(so, inp, 0);
447 
448 	if (tp->t_flags & TF_LISTEN)
449 		goto out;
450 
451 	if (inp->inp_lport == 0) {
452 		if (!(inp->inp_flags & IN6P_IPV6_V6ONLY))
453 			inp->inp_vflag |= INP_IPV4;
454 		else
455 			inp->inp_vflag &= ~INP_IPV4;
456 		error = in6_pcbbind(inp, NULL, td);
457 		if (error)
458 			goto out;
459 	}
460 
461 	tp->t_state = TCPS_LISTEN;
462 	tp->t_flags |= TF_LISTEN;
463 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
464 
465 #ifdef SMP
466 	if (ncpus > 1) {
467 		/*
468 		 * We have to set the flag because we can't have other cpus
469 		 * messing with our inp's flags.
470 		 */
471 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
472 			("already on connhash\n"));
473 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
474 			("already on wildcardhash\n"));
475 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
476 			("already on MP wildcardhash\n"));
477 		inp->inp_flags |= INP_WILDCARD_MP;
478 
479 		KKASSERT(so->so_port == cpu_portfn(0));
480 		KKASSERT(&curthread->td_msgport == cpu_portfn(0));
481 		KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
482 
483 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
484 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
485 		nm.nm_inp = inp;
486 		lwkt_domsg(cpu_portfn(1), &nm.base.lmsg, 0);
487 	}
488 #endif
489 	in_pcbinswildcardhash(inp);
490 	COMMON_END(PRU_LISTEN);
491 }
492 #endif /* INET6 */
493 
494 /*
495  * Initiate connection to peer.
496  * Create a template for use in transmissions on this connection.
497  * Enter SYN_SENT state, and mark socket as connecting.
498  * Start keep-alive timer, and seed output sequence space.
499  * Send initial segment on connection.
500  */
501 static void
502 tcp_usr_connect(netmsg_t msg)
503 {
504 	struct socket *so = msg->connect.base.nm_so;
505 	struct sockaddr *nam = msg->connect.nm_nam;
506 	struct thread *td = msg->connect.nm_td;
507 	int error = 0;
508 	struct inpcb *inp;
509 	struct tcpcb *tp;
510 	struct sockaddr_in *sinp;
511 
512 	COMMON_START(so, inp, 0);
513 
514 	/*
515 	 * Must disallow TCP ``connections'' to multicast addresses.
516 	 */
517 	sinp = (struct sockaddr_in *)nam;
518 	if (sinp->sin_family == AF_INET
519 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
520 		error = EAFNOSUPPORT;
521 		goto out;
522 	}
523 
524 	if (!prison_remote_ip(td, (struct sockaddr*)sinp)) {
525 		error = EAFNOSUPPORT; /* IPv6 only jail */
526 		goto out;
527 	}
528 
529 	tcp_connect(msg);
530 	/* msg is invalid now */
531 	return;
532 out:
533 	if (msg->connect.nm_m) {
534 		m_freem(msg->connect.nm_m);
535 		msg->connect.nm_m = NULL;
536 	}
537 	lwkt_replymsg(&msg->lmsg, error);
538 }
539 
540 #ifdef INET6
541 
542 static void
543 tcp6_usr_connect(netmsg_t msg)
544 {
545 	struct socket *so = msg->connect.base.nm_so;
546 	struct sockaddr *nam = msg->connect.nm_nam;
547 	struct thread *td = msg->connect.nm_td;
548 	int error = 0;
549 	struct inpcb *inp;
550 	struct tcpcb *tp;
551 	struct sockaddr_in6 *sin6p;
552 
553 	COMMON_START(so, inp, 0);
554 
555 	/*
556 	 * Must disallow TCP ``connections'' to multicast addresses.
557 	 */
558 	sin6p = (struct sockaddr_in6 *)nam;
559 	if (sin6p->sin6_family == AF_INET6
560 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
561 		error = EAFNOSUPPORT;
562 		goto out;
563 	}
564 
565 	if (!prison_remote_ip(td, nam)) {
566 		error = EAFNOSUPPORT; /* IPv4 only jail */
567 		goto out;
568 	}
569 
570 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
571 		struct sockaddr_in *sinp;
572 
573 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
574 			error = EINVAL;
575 			goto out;
576 		}
577 		sinp = kmalloc(sizeof(*sinp), M_LWKTMSG, M_INTWAIT);
578 		in6_sin6_2_sin(sinp, sin6p);
579 		inp->inp_vflag |= INP_IPV4;
580 		inp->inp_vflag &= ~INP_IPV6;
581 		msg->connect.nm_nam = (struct sockaddr *)sinp;
582 		msg->connect.nm_reconnect |= NMSG_RECONNECT_NAMALLOC;
583 		tcp_connect(msg);
584 		/* msg is invalid now */
585 		return;
586 	}
587 	inp->inp_vflag &= ~INP_IPV4;
588 	inp->inp_vflag |= INP_IPV6;
589 	inp->inp_inc.inc_isipv6 = 1;
590 
591 	msg->connect.nm_reconnect |= NMSG_RECONNECT_FALLBACK;
592 	tcp6_connect(msg);
593 	/* msg is invalid now */
594 	return;
595 out:
596 	if (msg->connect.nm_m) {
597 		m_freem(msg->connect.nm_m);
598 		msg->connect.nm_m = NULL;
599 	}
600 	lwkt_replymsg(&msg->lmsg, error);
601 }
602 
603 #endif /* INET6 */
604 
605 /*
606  * Initiate disconnect from peer.
607  * If connection never passed embryonic stage, just drop;
608  * else if don't need to let data drain, then can just drop anyways,
609  * else have to begin TCP shutdown process: mark socket disconnecting,
610  * drain unread data, state switch to reflect user close, and
611  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
612  * when peer sends FIN and acks ours.
613  *
614  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
615  */
616 static void
617 tcp_usr_disconnect(netmsg_t msg)
618 {
619 	struct socket *so = msg->disconnect.base.nm_so;
620 	int error = 0;
621 	struct inpcb *inp;
622 	struct tcpcb *tp;
623 
624 	COMMON_START(so, inp, 1);
625 	tp = tcp_disconnect(tp);
626 	COMMON_END(PRU_DISCONNECT);
627 }
628 
629 /*
630  * Accept a connection.  Essentially all the work is
631  * done at higher levels; just return the address
632  * of the peer, storing through addr.
633  */
634 static void
635 tcp_usr_accept(netmsg_t msg)
636 {
637 	struct socket *so = msg->accept.base.nm_so;
638 	struct sockaddr **nam = msg->accept.nm_nam;
639 	int error = 0;
640 	struct inpcb *inp;
641 	struct tcpcb *tp = NULL;
642 	TCPDEBUG0;
643 
644 	inp = so->so_pcb;
645 	if (so->so_state & SS_ISDISCONNECTED) {
646 		error = ECONNABORTED;
647 		goto out;
648 	}
649 	if (inp == 0) {
650 		error = EINVAL;
651 		goto out;
652 	}
653 
654 	tp = intotcpcb(inp);
655 	TCPDEBUG1();
656 	in_setpeeraddr(so, nam);
657 	COMMON_END(PRU_ACCEPT);
658 }
659 
660 #ifdef INET6
661 static void
662 tcp6_usr_accept(netmsg_t msg)
663 {
664 	struct socket *so = msg->accept.base.nm_so;
665 	struct sockaddr **nam = msg->accept.nm_nam;
666 	int error = 0;
667 	struct inpcb *inp;
668 	struct tcpcb *tp = NULL;
669 	TCPDEBUG0;
670 
671 	inp = so->so_pcb;
672 
673 	if (so->so_state & SS_ISDISCONNECTED) {
674 		error = ECONNABORTED;
675 		goto out;
676 	}
677 	if (inp == 0) {
678 		error = EINVAL;
679 		goto out;
680 	}
681 	tp = intotcpcb(inp);
682 	TCPDEBUG1();
683 	in6_mapped_peeraddr(so, nam);
684 	COMMON_END(PRU_ACCEPT);
685 }
686 #endif /* INET6 */
687 /*
688  * Mark the connection as being incapable of further output.
689  */
690 static void
691 tcp_usr_shutdown(netmsg_t msg)
692 {
693 	struct socket *so = msg->shutdown.base.nm_so;
694 	int error = 0;
695 	struct inpcb *inp;
696 	struct tcpcb *tp;
697 
698 	COMMON_START(so, inp, 0);
699 	socantsendmore(so);
700 	tp = tcp_usrclosed(tp);
701 	if (tp)
702 		error = tcp_output(tp);
703 	COMMON_END(PRU_SHUTDOWN);
704 }
705 
706 /*
707  * After a receive, possibly send window update to peer.
708  */
709 static void
710 tcp_usr_rcvd(netmsg_t msg)
711 {
712 	struct socket *so = msg->rcvd.base.nm_so;
713 	int error = 0;
714 	struct inpcb *inp;
715 	struct tcpcb *tp;
716 
717 	COMMON_START(so, inp, 0);
718 	tcp_output(tp);
719 	COMMON_END(PRU_RCVD);
720 }
721 
722 /*
723  * Do a send by putting data in output queue and updating urgent
724  * marker if URG set.  Possibly send more data.  Unlike the other
725  * pru_*() routines, the mbuf chains are our responsibility.  We
726  * must either enqueue them or free them.  The other pru_* routines
727  * generally are caller-frees.
728  */
729 static void
730 tcp_usr_send(netmsg_t msg)
731 {
732 	struct socket *so = msg->send.base.nm_so;
733 	int flags = msg->send.nm_flags;
734 	struct mbuf *m = msg->send.nm_m;
735 	struct mbuf *control = msg->send.nm_control;
736 	int error = 0;
737 	struct inpcb *inp;
738 	struct tcpcb *tp;
739 	TCPDEBUG0;
740 
741 	KKASSERT(control == NULL);
742 
743 	inp = so->so_pcb;
744 
745 	if (inp == NULL) {
746 		/*
747 		 * OOPS! we lost a race, the TCP session got reset after
748 		 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a
749 		 * network interrupt in the non-critical section of sosend().
750 		 */
751 		m_freem(m);
752 		error = ECONNRESET;	/* XXX EPIPE? */
753 		tp = NULL;
754 		TCPDEBUG1();
755 		goto out;
756 	}
757 	tp = intotcpcb(inp);
758 	TCPDEBUG1();
759 
760 	/*
761 	 * Don't let too much OOB data build up
762 	 */
763 	if (flags & PRUS_OOB) {
764 		if (ssb_space(&so->so_snd) < -512) {
765 			m_freem(m);
766 			error = ENOBUFS;
767 			goto out;
768 		}
769 	}
770 
771 	/*
772 	 * Pump the data into the socket.
773 	 */
774 	if (m)
775 		ssb_appendstream(&so->so_snd, m);
776 	if (flags & PRUS_OOB) {
777 		/*
778 		 * According to RFC961 (Assigned Protocols),
779 		 * the urgent pointer points to the last octet
780 		 * of urgent data.  We continue, however,
781 		 * to consider it to indicate the first octet
782 		 * of data past the urgent section.
783 		 * Otherwise, snd_up should be one lower.
784 		 */
785 		tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
786 		tp->t_flags |= TF_FORCE;
787 		error = tcp_output(tp);
788 		tp->t_flags &= ~TF_FORCE;
789 	} else {
790 		if (flags & PRUS_EOF) {
791 			/*
792 			 * Close the send side of the connection after
793 			 * the data is sent.
794 			 */
795 			socantsendmore(so);
796 			tp = tcp_usrclosed(tp);
797 		}
798 		if (tp != NULL) {
799 			if (flags & PRUS_MORETOCOME)
800 				tp->t_flags |= TF_MORETOCOME;
801 			error = tcp_output(tp);
802 			if (flags & PRUS_MORETOCOME)
803 				tp->t_flags &= ~TF_MORETOCOME;
804 		}
805 	}
806 	COMMON_END1((flags & PRUS_OOB) ? PRU_SENDOOB :
807 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND),
808 		   (flags & PRUS_NOREPLY));
809 }
810 
811 /*
812  * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
813  *	 will sofree() it when we return.
814  */
815 static void
816 tcp_usr_abort(netmsg_t msg)
817 {
818 	struct socket *so = msg->abort.base.nm_so;
819 	int error = 0;
820 	struct inpcb *inp;
821 	struct tcpcb *tp;
822 
823 	COMMON_START(so, inp, 1);
824 	tp = tcp_drop(tp, ECONNABORTED);
825 	COMMON_END(PRU_ABORT);
826 }
827 
828 /*
829  * Receive out-of-band data.
830  */
831 static void
832 tcp_usr_rcvoob(netmsg_t msg)
833 {
834 	struct socket *so = msg->rcvoob.base.nm_so;
835 	struct mbuf *m = msg->rcvoob.nm_m;
836 	int flags = msg->rcvoob.nm_flags;
837 	int error = 0;
838 	struct inpcb *inp;
839 	struct tcpcb *tp;
840 
841 	COMMON_START(so, inp, 0);
842 	if ((so->so_oobmark == 0 &&
843 	     (so->so_state & SS_RCVATMARK) == 0) ||
844 	    so->so_options & SO_OOBINLINE ||
845 	    tp->t_oobflags & TCPOOB_HADDATA) {
846 		error = EINVAL;
847 		goto out;
848 	}
849 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
850 		error = EWOULDBLOCK;
851 		goto out;
852 	}
853 	m->m_len = 1;
854 	*mtod(m, caddr_t) = tp->t_iobc;
855 	if ((flags & MSG_PEEK) == 0)
856 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
857 	COMMON_END(PRU_RCVOOB);
858 }
859 
860 /* xxx - should be const */
861 struct pr_usrreqs tcp_usrreqs = {
862 	.pru_abort = tcp_usr_abort,
863 	.pru_accept = tcp_usr_accept,
864 	.pru_attach = tcp_usr_attach,
865 	.pru_bind = tcp_usr_bind,
866 	.pru_connect = tcp_usr_connect,
867 	.pru_connect2 = pr_generic_notsupp,
868 	.pru_control = in_control_dispatch,
869 	.pru_detach = tcp_usr_detach,
870 	.pru_disconnect = tcp_usr_disconnect,
871 	.pru_listen = tcp_usr_listen,
872 	.pru_peeraddr = in_setpeeraddr_dispatch,
873 	.pru_rcvd = tcp_usr_rcvd,
874 	.pru_rcvoob = tcp_usr_rcvoob,
875 	.pru_send = tcp_usr_send,
876 	.pru_sense = pru_sense_null,
877 	.pru_shutdown = tcp_usr_shutdown,
878 	.pru_sockaddr = in_setsockaddr_dispatch,
879 	.pru_sosend = sosendtcp,
880 	.pru_soreceive = soreceive
881 };
882 
883 #ifdef INET6
884 struct pr_usrreqs tcp6_usrreqs = {
885 	.pru_abort = tcp_usr_abort,
886 	.pru_accept = tcp6_usr_accept,
887 	.pru_attach = tcp_usr_attach,
888 	.pru_bind = tcp6_usr_bind,
889 	.pru_connect = tcp6_usr_connect,
890 	.pru_connect2 = pr_generic_notsupp,
891 	.pru_control = in6_control_dispatch,
892 	.pru_detach = tcp_usr_detach,
893 	.pru_disconnect = tcp_usr_disconnect,
894 	.pru_listen = tcp6_usr_listen,
895 	.pru_peeraddr = in6_mapped_peeraddr_dispatch,
896 	.pru_rcvd = tcp_usr_rcvd,
897 	.pru_rcvoob = tcp_usr_rcvoob,
898 	.pru_send = tcp_usr_send,
899 	.pru_sense = pru_sense_null,
900 	.pru_shutdown = tcp_usr_shutdown,
901 	.pru_sockaddr = in6_mapped_sockaddr_dispatch,
902 	.pru_sosend = sosendtcp,
903 	.pru_soreceive = soreceive
904 };
905 #endif /* INET6 */
906 
907 static int
908 tcp_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf *m,
909 		  struct sockaddr_in *sin, struct sockaddr_in *if_sin)
910 {
911 	struct inpcb *inp = tp->t_inpcb, *oinp;
912 	struct socket *so = inp->inp_socket;
913 	struct route *ro = &inp->inp_route;
914 
915 	oinp = in_pcblookup_hash(&tcbinfo[mycpu->gd_cpuid],
916 				 sin->sin_addr, sin->sin_port,
917 				 (inp->inp_laddr.s_addr != INADDR_ANY ?
918 				  inp->inp_laddr : if_sin->sin_addr),
919 				inp->inp_lport, 0, NULL);
920 	if (oinp != NULL) {
921 		m_freem(m);
922 		return (EADDRINUSE);
923 	}
924 	if (inp->inp_laddr.s_addr == INADDR_ANY)
925 		inp->inp_laddr = if_sin->sin_addr;
926 	inp->inp_faddr = sin->sin_addr;
927 	inp->inp_fport = sin->sin_port;
928 	inp->inp_cpcbinfo = &tcbinfo[mycpu->gd_cpuid];
929 	in_pcbinsconnhash(inp);
930 
931 	/*
932 	 * We are now on the inpcb's owner CPU, if the cached route was
933 	 * freed because the rtentry's owner CPU is not the current CPU
934 	 * (e.g. in tcp_connect()), then we try to reallocate it here with
935 	 * the hope that a rtentry may be cloned from a RTF_PRCLONING
936 	 * rtentry.
937 	 */
938 	if (!(inp->inp_socket->so_options & SO_DONTROUTE) && /*XXX*/
939 	    ro->ro_rt == NULL) {
940 		bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
941 		ro->ro_dst.sa_family = AF_INET;
942 		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
943 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr =
944 			sin->sin_addr;
945 		rtalloc(ro);
946 	}
947 
948 	/*
949 	 * Now that no more errors can occur, change the protocol processing
950 	 * port to the current thread (which is the correct thread).
951 	 *
952 	 * Create TCP timer message now; we are on the tcpcb's owner
953 	 * CPU/thread.
954 	 */
955 	tcp_create_timermsg(tp, &curthread->td_msgport);
956 
957 	/*
958 	 * Compute window scaling to request.  Use a larger scaling then
959 	 * needed for the initial receive buffer in case the receive buffer
960 	 * gets expanded.
961 	 */
962 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
963 		tp->request_r_scale = TCP_MIN_WINSHIFT;
964 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
965 	       (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat
966 	) {
967 		tp->request_r_scale++;
968 	}
969 
970 	soisconnecting(so);
971 	tcpstat.tcps_connattempt++;
972 	tp->t_state = TCPS_SYN_SENT;
973 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
974 	tp->iss = tcp_new_isn(tp);
975 	tcp_sendseqinit(tp);
976 	if (m) {
977 		ssb_appendstream(&so->so_snd, m);
978 		m = NULL;
979 		if (flags & PRUS_OOB)
980 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
981 	}
982 
983 	/*
984 	 * Close the send side of the connection after
985 	 * the data is sent if flagged.
986 	 */
987 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
988 		socantsendmore(so);
989 		tp = tcp_usrclosed(tp);
990 	}
991 	return (tcp_output(tp));
992 }
993 
994 /*
995  * Common subroutine to open a TCP connection to remote host specified
996  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
997  * port number if needed.  Call in_pcbladdr to do the routing and to choose
998  * a local host address (interface).
999  * Initialize connection parameters and enter SYN-SENT state.
1000  */
1001 static void
1002 tcp_connect(netmsg_t msg)
1003 {
1004 	struct socket *so = msg->connect.base.nm_so;
1005 	struct sockaddr *nam = msg->connect.nm_nam;
1006 	struct thread *td = msg->connect.nm_td;
1007 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
1008 	struct sockaddr_in *if_sin;
1009 	struct inpcb *inp;
1010 	struct tcpcb *tp;
1011 	int error, calc_laddr = 1;
1012 #ifdef SMP
1013 	lwkt_port_t port;
1014 #endif
1015 
1016 	COMMON_START(so, inp, 0);
1017 
1018 	/*
1019 	 * Reconnect our pcb if we have to
1020 	 */
1021 	if (msg->connect.nm_reconnect & NMSG_RECONNECT_RECONNECT) {
1022 		msg->connect.nm_reconnect &= ~NMSG_RECONNECT_RECONNECT;
1023 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1024 	}
1025 
1026 	/*
1027 	 * Bind if we have to
1028 	 */
1029 	if (inp->inp_lport == 0) {
1030 		if (tcp_lport_extension) {
1031 			KKASSERT(inp->inp_laddr.s_addr == INADDR_ANY);
1032 
1033 			error = in_pcbladdr(inp, nam, &if_sin, td);
1034 			if (error)
1035 				goto out;
1036 			inp->inp_laddr.s_addr = if_sin->sin_addr.s_addr;
1037 
1038 			error = in_pcbconn_bind(inp, nam, td);
1039 			if (error)
1040 				goto out;
1041 
1042 			calc_laddr = 0;
1043 		} else {
1044 			error = in_pcbbind(inp, NULL, td);
1045 			if (error)
1046 				goto out;
1047 		}
1048 	}
1049 
1050 	if (calc_laddr) {
1051 		/*
1052 		 * Calculate the correct protocol processing thread.  The
1053 		 * connect operation must run there.  Set the forwarding
1054 		 * port before we forward the message or it will get bounced
1055 		 * right back to us.
1056 		 */
1057 		error = in_pcbladdr(inp, nam, &if_sin, td);
1058 		if (error)
1059 			goto out;
1060 	}
1061 	KKASSERT(inp->inp_socket == so);
1062 
1063 #ifdef SMP
1064 	port = tcp_addrport(sin->sin_addr.s_addr, sin->sin_port,
1065 			    (inp->inp_laddr.s_addr ?
1066 			     inp->inp_laddr.s_addr : if_sin->sin_addr.s_addr),
1067 			    inp->inp_lport);
1068 
1069 	if (port != &curthread->td_msgport) {
1070 		struct route *ro = &inp->inp_route;
1071 
1072 		/*
1073 		 * in_pcbladdr() may have allocated a route entry for us
1074 		 * on the current CPU, but we need a route entry on the
1075 		 * inpcb's owner CPU, so free it here.
1076 		 */
1077 		if (ro->ro_rt != NULL)
1078 			RTFREE(ro->ro_rt);
1079 		bzero(ro, sizeof(*ro));
1080 
1081 		/*
1082 		 * We are moving the protocol processing port the socket
1083 		 * is on, we have to unlink here and re-link on the
1084 		 * target cpu.
1085 		 */
1086 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1087 		sosetport(so, port);
1088 		msg->connect.nm_reconnect |= NMSG_RECONNECT_RECONNECT;
1089 		msg->connect.base.nm_dispatch = tcp_connect;
1090 
1091 		lwkt_forwardmsg(port, &msg->connect.base.lmsg);
1092 		/* msg invalid now */
1093 		return;
1094 	}
1095 #else
1096 	KKASSERT(so->so_port == &curthread->td_msgport);
1097 #endif
1098 	error = tcp_connect_oncpu(tp, msg->connect.nm_flags,
1099 				  msg->connect.nm_m, sin, if_sin);
1100 	msg->connect.nm_m = NULL;
1101 out:
1102 	if (msg->connect.nm_m) {
1103 		m_freem(msg->connect.nm_m);
1104 		msg->connect.nm_m = NULL;
1105 	}
1106 	if (msg->connect.nm_reconnect & NMSG_RECONNECT_NAMALLOC) {
1107 		kfree(msg->connect.nm_nam, M_LWKTMSG);
1108 		msg->connect.nm_nam = NULL;
1109 	}
1110 	lwkt_replymsg(&msg->connect.base.lmsg, error);
1111 	/* msg invalid now */
1112 }
1113 
1114 #ifdef INET6
1115 
1116 static void
1117 tcp6_connect(netmsg_t msg)
1118 {
1119 	struct tcpcb *tp;
1120 	struct socket *so = msg->connect.base.nm_so;
1121 	struct sockaddr *nam = msg->connect.nm_nam;
1122 	struct thread *td = msg->connect.nm_td;
1123 	struct inpcb *inp;
1124 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1125 	struct in6_addr *addr6;
1126 #ifdef SMP
1127 	lwkt_port_t port;
1128 #endif
1129 	int error;
1130 
1131 	COMMON_START(so, inp, 0);
1132 
1133 	/*
1134 	 * Reconnect our pcb if we have to
1135 	 */
1136 	if (msg->connect.nm_reconnect & NMSG_RECONNECT_RECONNECT) {
1137 		msg->connect.nm_reconnect &= ~NMSG_RECONNECT_RECONNECT;
1138 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1139 	}
1140 
1141 	/*
1142 	 * Bind if we have to
1143 	 */
1144 	if (inp->inp_lport == 0) {
1145 		error = in6_pcbbind(inp, NULL, td);
1146 		if (error)
1147 			goto out;
1148 	}
1149 
1150 	/*
1151 	 * Cannot simply call in_pcbconnect, because there might be an
1152 	 * earlier incarnation of this same connection still in
1153 	 * TIME_WAIT state, creating an ADDRINUSE error.
1154 	 */
1155 	error = in6_pcbladdr(inp, nam, &addr6, td);
1156 	if (error)
1157 		goto out;
1158 
1159 #ifdef SMP
1160 	port = tcp6_addrport();	/* XXX hack for now, always cpu0 */
1161 
1162 	if (port != &curthread->td_msgport) {
1163 		struct route *ro = &inp->inp_route;
1164 
1165 		/*
1166 		 * in_pcbladdr() may have allocated a route entry for us
1167 		 * on the current CPU, but we need a route entry on the
1168 		 * inpcb's owner CPU, so free it here.
1169 		 */
1170 		if (ro->ro_rt != NULL)
1171 			RTFREE(ro->ro_rt);
1172 		bzero(ro, sizeof(*ro));
1173 
1174 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1175 		sosetport(so, port);
1176 		msg->connect.nm_reconnect |= NMSG_RECONNECT_RECONNECT;
1177 		msg->connect.base.nm_dispatch = tcp6_connect;
1178 
1179 		lwkt_forwardmsg(port, &msg->connect.base.lmsg);
1180 		/* msg invalid now */
1181 		return;
1182 	}
1183 #endif
1184 	error = tcp6_connect_oncpu(tp, msg->connect.nm_flags,
1185 				   &msg->connect.nm_m, sin6, addr6);
1186 	/* nm_m may still be intact */
1187 out:
1188 	if (error && (msg->connect.nm_reconnect & NMSG_RECONNECT_FALLBACK)) {
1189 		tcp_connect(msg);
1190 		/* msg invalid now */
1191 	} else {
1192 		if (msg->connect.nm_m) {
1193 			m_freem(msg->connect.nm_m);
1194 			msg->connect.nm_m = NULL;
1195 		}
1196 		if (msg->connect.nm_reconnect & NMSG_RECONNECT_NAMALLOC) {
1197 			kfree(msg->connect.nm_nam, M_LWKTMSG);
1198 			msg->connect.nm_nam = NULL;
1199 		}
1200 		lwkt_replymsg(&msg->connect.base.lmsg, error);
1201 		/* msg invalid now */
1202 	}
1203 }
1204 
1205 static int
1206 tcp6_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf **mp,
1207 		   struct sockaddr_in6 *sin6, struct in6_addr *addr6)
1208 {
1209 	struct mbuf *m = *mp;
1210 	struct inpcb *inp = tp->t_inpcb;
1211 	struct socket *so = inp->inp_socket;
1212 	struct inpcb *oinp;
1213 
1214 	/*
1215 	 * Cannot simply call in_pcbconnect, because there might be an
1216 	 * earlier incarnation of this same connection still in
1217 	 * TIME_WAIT state, creating an ADDRINUSE error.
1218 	 */
1219 	oinp = in6_pcblookup_hash(inp->inp_cpcbinfo,
1220 				  &sin6->sin6_addr, sin6->sin6_port,
1221 				  (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ?
1222 				      addr6 : &inp->in6p_laddr),
1223 				  inp->inp_lport,  0, NULL);
1224 	if (oinp)
1225 		return (EADDRINUSE);
1226 
1227 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1228 		inp->in6p_laddr = *addr6;
1229 	inp->in6p_faddr = sin6->sin6_addr;
1230 	inp->inp_fport = sin6->sin6_port;
1231 	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != 0)
1232 		inp->in6p_flowinfo = sin6->sin6_flowinfo;
1233 	in_pcbinsconnhash(inp);
1234 
1235 	/*
1236 	 * Now that no more errors can occur, change the protocol processing
1237 	 * port to the current thread (which is the correct thread).
1238 	 *
1239 	 * Create TCP timer message now; we are on the tcpcb's owner
1240 	 * CPU/thread.
1241 	 */
1242 	tcp_create_timermsg(tp, &curthread->td_msgport);
1243 
1244 	/* Compute window scaling to request.  */
1245 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1246 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1247 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1248 	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat) {
1249 		tp->request_r_scale++;
1250 	}
1251 
1252 	soisconnecting(so);
1253 	tcpstat.tcps_connattempt++;
1254 	tp->t_state = TCPS_SYN_SENT;
1255 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1256 	tp->iss = tcp_new_isn(tp);
1257 	tcp_sendseqinit(tp);
1258 	if (m) {
1259 		ssb_appendstream(&so->so_snd, m);
1260 		*mp = NULL;
1261 		if (flags & PRUS_OOB)
1262 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1263 	}
1264 
1265 	/*
1266 	 * Close the send side of the connection after
1267 	 * the data is sent if flagged.
1268 	 */
1269 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1270 		socantsendmore(so);
1271 		tp = tcp_usrclosed(tp);
1272 	}
1273 	return (tcp_output(tp));
1274 }
1275 
1276 #endif /* INET6 */
1277 
1278 /*
1279  * The new sockopt interface makes it possible for us to block in the
1280  * copyin/out step (if we take a page fault).  Taking a page fault while
1281  * in a critical section is probably a Bad Thing.  (Since sockets and pcbs
1282  * both now use TSM, there probably isn't any need for this function to
1283  * run in a critical section any more.  This needs more examination.)
1284  */
1285 void
1286 tcp_ctloutput(netmsg_t msg)
1287 {
1288 	struct socket *so = msg->base.nm_so;
1289 	struct sockopt *sopt = msg->ctloutput.nm_sopt;
1290 	int	error, opt, optval, opthz;
1291 	struct	inpcb *inp;
1292 	struct	tcpcb *tp;
1293 
1294 	error = 0;
1295 	inp = so->so_pcb;
1296 	if (inp == NULL) {
1297 		error = ECONNRESET;
1298 		goto done;
1299 	}
1300 
1301 	if (sopt->sopt_level != IPPROTO_TCP) {
1302 #ifdef INET6
1303 		if (INP_CHECK_SOCKAF(so, AF_INET6))
1304 			ip6_ctloutput_dispatch(msg);
1305 		else
1306 #endif /* INET6 */
1307 		ip_ctloutput(msg);
1308 		/* msg invalid now */
1309 		return;
1310 	}
1311 	tp = intotcpcb(inp);
1312 
1313 	switch (sopt->sopt_dir) {
1314 	case SOPT_SET:
1315 		error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1316 				      sizeof optval);
1317 		if (error)
1318 			break;
1319 		switch (sopt->sopt_name) {
1320 		case TCP_FASTKEEP:
1321 			if (optval > 0) {
1322 				if ((tp->t_flags & TF_FASTKEEP) == 0) {
1323 					tp->t_flags |= TF_FASTKEEP;
1324 					tcp_timer_keep_activity(tp, 0);
1325 				}
1326 			} else {
1327 				tp->t_flags &= ~TF_FASTKEEP;
1328 			}
1329 			break;
1330 #ifdef TCP_SIGNATURE
1331 		case TCP_SIGNATURE_ENABLE:
1332 			if (optval > 0)
1333 				tp->t_flags |= TF_SIGNATURE;
1334 			else
1335 				tp->t_flags &= ~TF_SIGNATURE;
1336 			break;
1337 #endif /* TCP_SIGNATURE */
1338 		case TCP_NODELAY:
1339 		case TCP_NOOPT:
1340 			switch (sopt->sopt_name) {
1341 			case TCP_NODELAY:
1342 				opt = TF_NODELAY;
1343 				break;
1344 			case TCP_NOOPT:
1345 				opt = TF_NOOPT;
1346 				break;
1347 			default:
1348 				opt = 0; /* dead code to fool gcc */
1349 				break;
1350 			}
1351 
1352 			if (optval)
1353 				tp->t_flags |= opt;
1354 			else
1355 				tp->t_flags &= ~opt;
1356 			break;
1357 
1358 		case TCP_NOPUSH:
1359 			if (optval)
1360 				tp->t_flags |= TF_NOPUSH;
1361 			else {
1362 				tp->t_flags &= ~TF_NOPUSH;
1363 				error = tcp_output(tp);
1364 			}
1365 			break;
1366 
1367 		case TCP_MAXSEG:
1368 			/*
1369 			 * Must be between 0 and maxseg.  If the requested
1370 			 * maxseg is too small to satisfy the desired minmss,
1371 			 * pump it up (silently so sysctl modifications of
1372 			 * minmss do not create unexpected program failures).
1373 			 * Handle degenerate cases.
1374 			 */
1375 			if (optval > 0 && optval <= tp->t_maxseg) {
1376 				if (optval + 40 < tcp_minmss) {
1377 					optval = tcp_minmss - 40;
1378 					if (optval < 0)
1379 						optval = 1;
1380 				}
1381 				tp->t_maxseg = optval;
1382 			} else {
1383 				error = EINVAL;
1384 			}
1385 			break;
1386 
1387 		case TCP_KEEPINIT:
1388 			opthz = ((int64_t)optval * hz) / 1000;
1389 			if (opthz >= 1)
1390 				tp->t_keepinit = opthz;
1391 			else
1392 				error = EINVAL;
1393 			break;
1394 
1395 		case TCP_KEEPIDLE:
1396 			opthz = ((int64_t)optval * hz) / 1000;
1397 			if (opthz >= 1)
1398 				tp->t_keepidle = opthz;
1399 			else
1400 				error = EINVAL;
1401 			break;
1402 
1403 		case TCP_KEEPINTVL:
1404 			opthz = ((int64_t)optval * hz) / 1000;
1405 			if (opthz >= 1) {
1406 				tp->t_keepintvl = opthz;
1407 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1408 			} else {
1409 				error = EINVAL;
1410 			}
1411 			break;
1412 
1413 		case TCP_KEEPCNT:
1414 			if (optval > 0) {
1415 				tp->t_keepcnt = optval;
1416 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1417 			} else {
1418 				error = EINVAL;
1419 			}
1420 			break;
1421 
1422 		default:
1423 			error = ENOPROTOOPT;
1424 			break;
1425 		}
1426 		break;
1427 
1428 	case SOPT_GET:
1429 		switch (sopt->sopt_name) {
1430 #ifdef TCP_SIGNATURE
1431 		case TCP_SIGNATURE_ENABLE:
1432 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1433 			break;
1434 #endif /* TCP_SIGNATURE */
1435 		case TCP_NODELAY:
1436 			optval = tp->t_flags & TF_NODELAY;
1437 			break;
1438 		case TCP_MAXSEG:
1439 			optval = tp->t_maxseg;
1440 			break;
1441 		case TCP_NOOPT:
1442 			optval = tp->t_flags & TF_NOOPT;
1443 			break;
1444 		case TCP_NOPUSH:
1445 			optval = tp->t_flags & TF_NOPUSH;
1446 			break;
1447 		case TCP_KEEPINIT:
1448 			optval = ((int64_t)tp->t_keepinit * 1000) / hz;
1449 			break;
1450 		case TCP_KEEPIDLE:
1451 			optval = ((int64_t)tp->t_keepidle * 1000) / hz;
1452 			break;
1453 		case TCP_KEEPINTVL:
1454 			optval = ((int64_t)tp->t_keepintvl * 1000) / hz;
1455 			break;
1456 		case TCP_KEEPCNT:
1457 			optval = tp->t_keepcnt;
1458 			break;
1459 		default:
1460 			error = ENOPROTOOPT;
1461 			break;
1462 		}
1463 		if (error == 0)
1464 			soopt_from_kbuf(sopt, &optval, sizeof optval);
1465 		break;
1466 	}
1467 done:
1468 	lwkt_replymsg(&msg->lmsg, error);
1469 }
1470 
1471 /*
1472  * tcp_sendspace and tcp_recvspace are the default send and receive window
1473  * sizes, respectively.  These are obsolescent (this information should
1474  * be set by the route).
1475  *
1476  * Use a default that does not require tcp window scaling to be turned
1477  * on.  Individual programs or the administrator can increase the default.
1478  */
1479 u_long	tcp_sendspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1480 SYSCTL_INT(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1481     &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1482 u_long	tcp_recvspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1483 SYSCTL_INT(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1484     &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1485 
1486 /*
1487  * Attach TCP protocol to socket, allocating internet protocol control
1488  * block, tcp control block, bufer space, and entering LISTEN state
1489  * if to accept connections.
1490  */
1491 static int
1492 tcp_attach(struct socket *so, struct pru_attach_info *ai)
1493 {
1494 	struct tcpcb *tp;
1495 	struct inpcb *inp;
1496 	int error;
1497 	int cpu;
1498 #ifdef INET6
1499 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
1500 #endif
1501 
1502 	if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
1503 		lwkt_gettoken(&so->so_rcv.ssb_token);
1504 		error = soreserve(so, tcp_sendspace, tcp_recvspace,
1505 				  ai->sb_rlimit);
1506 		lwkt_reltoken(&so->so_rcv.ssb_token);
1507 		if (error)
1508 			return (error);
1509 	}
1510 	atomic_set_int(&so->so_rcv.ssb_flags, SSB_AUTOSIZE);
1511 	atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOSIZE);
1512 	cpu = mycpu->gd_cpuid;
1513 
1514 	/*
1515 	 * Set the default port for protocol processing. This will likely
1516 	 * change when we connect.
1517 	 */
1518 	error = in_pcballoc(so, &tcbinfo[cpu]);
1519 	if (error)
1520 		return (error);
1521 	inp = so->so_pcb;
1522 #ifdef INET6
1523 	if (isipv6) {
1524 		inp->inp_vflag |= INP_IPV6;
1525 		inp->in6p_hops = -1;	/* use kernel default */
1526 	}
1527 	else
1528 #endif
1529 	inp->inp_vflag |= INP_IPV4;
1530 	tp = tcp_newtcpcb(inp);
1531 	if (tp == NULL) {
1532 		/*
1533 		 * Make sure the socket is destroyed by the pcbdetach.
1534 		 */
1535 		soreference(so);
1536 #ifdef INET6
1537 		if (isipv6)
1538 			in6_pcbdetach(inp);
1539 		else
1540 #endif
1541 		in_pcbdetach(inp);
1542 		sofree(so);	/* from ref above */
1543 		return (ENOBUFS);
1544 	}
1545 	tp->t_state = TCPS_CLOSED;
1546 	return (0);
1547 }
1548 
1549 /*
1550  * Initiate (or continue) disconnect.
1551  * If embryonic state, just send reset (once).
1552  * If in ``let data drain'' option and linger null, just drop.
1553  * Otherwise (hard), mark socket disconnecting and drop
1554  * current input data; switch states based on user close, and
1555  * send segment to peer (with FIN).
1556  */
1557 static struct tcpcb *
1558 tcp_disconnect(struct tcpcb *tp)
1559 {
1560 	struct socket *so = tp->t_inpcb->inp_socket;
1561 
1562 	if (tp->t_state < TCPS_ESTABLISHED) {
1563 		tp = tcp_close(tp);
1564 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1565 		tp = tcp_drop(tp, 0);
1566 	} else {
1567 		lwkt_gettoken(&so->so_rcv.ssb_token);
1568 		soisdisconnecting(so);
1569 		sbflush(&so->so_rcv.sb);
1570 		tp = tcp_usrclosed(tp);
1571 		if (tp)
1572 			tcp_output(tp);
1573 		lwkt_reltoken(&so->so_rcv.ssb_token);
1574 	}
1575 	return (tp);
1576 }
1577 
1578 /*
1579  * User issued close, and wish to trail through shutdown states:
1580  * if never received SYN, just forget it.  If got a SYN from peer,
1581  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1582  * If already got a FIN from peer, then almost done; go to LAST_ACK
1583  * state.  In all other cases, have already sent FIN to peer (e.g.
1584  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1585  * for peer to send FIN or not respond to keep-alives, etc.
1586  * We can let the user exit from the close as soon as the FIN is acked.
1587  */
1588 static struct tcpcb *
1589 tcp_usrclosed(struct tcpcb *tp)
1590 {
1591 
1592 	switch (tp->t_state) {
1593 
1594 	case TCPS_CLOSED:
1595 	case TCPS_LISTEN:
1596 		tp->t_state = TCPS_CLOSED;
1597 		tp = tcp_close(tp);
1598 		break;
1599 
1600 	case TCPS_SYN_SENT:
1601 	case TCPS_SYN_RECEIVED:
1602 		tp->t_flags |= TF_NEEDFIN;
1603 		break;
1604 
1605 	case TCPS_ESTABLISHED:
1606 		tp->t_state = TCPS_FIN_WAIT_1;
1607 		break;
1608 
1609 	case TCPS_CLOSE_WAIT:
1610 		tp->t_state = TCPS_LAST_ACK;
1611 		break;
1612 	}
1613 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1614 		soisdisconnected(tp->t_inpcb->inp_socket);
1615 		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
1616 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1617 			tcp_callout_reset(tp, tp->tt_2msl, tp->t_maxidle,
1618 			    tcp_timer_2msl);
1619 		}
1620 	}
1621 	return (tp);
1622 }
1623