xref: /dragonfly/sys/netinet/tcp_usrreq.c (revision cfd1aba3)
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. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  *
62  *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
63  * $FreeBSD: src/sys/netinet/tcp_usrreq.c,v 1.51.2.17 2002/10/11 11:46:44 ume Exp $
64  */
65 
66 #include "opt_ipsec.h"
67 #include "opt_inet.h"
68 #include "opt_inet6.h"
69 #include "opt_tcpdebug.h"
70 
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/kernel.h>
74 #include <sys/malloc.h>
75 #include <sys/sysctl.h>
76 #include <sys/globaldata.h>
77 #include <sys/thread.h>
78 
79 #include <sys/mbuf.h>
80 #ifdef INET6
81 #include <sys/domain.h>
82 #endif /* INET6 */
83 #include <sys/socket.h>
84 #include <sys/socketvar.h>
85 #include <sys/socketops.h>
86 #include <sys/protosw.h>
87 
88 #include <sys/thread2.h>
89 #include <sys/msgport2.h>
90 #include <sys/socketvar2.h>
91 
92 #include <net/if.h>
93 #include <net/netisr.h>
94 #include <net/route.h>
95 
96 #include <net/netmsg2.h>
97 #include <net/netisr2.h>
98 
99 #include <netinet/in.h>
100 #include <netinet/in_systm.h>
101 #ifdef INET6
102 #include <netinet/ip6.h>
103 #endif
104 #include <netinet/in_pcb.h>
105 #ifdef INET6
106 #include <netinet6/in6_pcb.h>
107 #endif
108 #include <netinet/in_var.h>
109 #include <netinet/ip_var.h>
110 #ifdef INET6
111 #include <netinet6/ip6_var.h>
112 #include <netinet6/tcp6_var.h>
113 #endif
114 #include <netinet/tcp.h>
115 #include <netinet/tcp_fsm.h>
116 #include <netinet/tcp_seq.h>
117 #include <netinet/tcp_timer.h>
118 #include <netinet/tcp_timer2.h>
119 #include <netinet/tcp_var.h>
120 #include <netinet/tcpip.h>
121 #ifdef TCPDEBUG
122 #include <netinet/tcp_debug.h>
123 #endif
124 
125 #ifdef IPSEC
126 #include <netinet6/ipsec.h>
127 #endif /*IPSEC*/
128 
129 /*
130  * TCP protocol interface to socket abstraction.
131  */
132 extern	char *tcpstates[];	/* XXX ??? */
133 
134 static int	tcp_attach (struct socket *, struct pru_attach_info *);
135 static void	tcp_connect (netmsg_t msg);
136 #ifdef INET6
137 static void	tcp6_connect (netmsg_t msg);
138 static int	tcp6_connect_oncpu(struct tcpcb *tp, int flags,
139 				struct mbuf **mp,
140 				struct sockaddr_in6 *sin6,
141 				struct in6_addr *addr6);
142 #endif /* INET6 */
143 static struct tcpcb *
144 		tcp_disconnect (struct tcpcb *);
145 static struct tcpcb *
146 		tcp_usrclosed (struct tcpcb *);
147 
148 #ifdef TCPDEBUG
149 #define	TCPDEBUG0	int ostate = 0
150 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
151 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
152 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
153 #else
154 #define	TCPDEBUG0
155 #define	TCPDEBUG1()
156 #define	TCPDEBUG2(req)
157 #endif
158 
159 static int	tcp_lport_extension = 1;
160 SYSCTL_INT(_net_inet_tcp, OID_AUTO, lportext, CTLFLAG_RW,
161     &tcp_lport_extension, 0, "");
162 
163 /*
164  * For some ill optimized programs, which try to use TCP_NOPUSH
165  * to improve performance, will have small amount of data sits
166  * in the sending buffer.  These small amount of data will _not_
167  * be pushed into the network until more data are written into
168  * the socket or the socket write side is shutdown.
169  */
170 static int	tcp_disable_nopush = 1;
171 SYSCTL_INT(_net_inet_tcp, OID_AUTO, disable_nopush, CTLFLAG_RW,
172     &tcp_disable_nopush, 0, "TCP_NOPUSH socket option will have no effect");
173 
174 /*
175  * TCP attaches to socket via pru_attach(), reserving space,
176  * and an internet control block.  This is likely occuring on
177  * cpu0 and may have to move later when we bind/connect.
178  */
179 static void
180 tcp_usr_attach(netmsg_t msg)
181 {
182 	struct socket *so = msg->base.nm_so;
183 	struct pru_attach_info *ai = msg->attach.nm_ai;
184 	int error;
185 	struct inpcb *inp;
186 	struct tcpcb *tp = NULL;
187 	TCPDEBUG0;
188 
189 	soreference(so);
190 	inp = so->so_pcb;
191 	TCPDEBUG1();
192 	if (inp) {
193 		error = EISCONN;
194 		goto out;
195 	}
196 
197 	error = tcp_attach(so, ai);
198 	if (error)
199 		goto out;
200 
201 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
202 		so->so_linger = TCP_LINGERTIME;
203 	tp = sototcpcb(so);
204 out:
205 	sofree(so);		/* from ref above */
206 	TCPDEBUG2(PRU_ATTACH);
207 	lwkt_replymsg(&msg->lmsg, error);
208 }
209 
210 /*
211  * pru_detach() detaches the TCP protocol from the socket.
212  * If the protocol state is non-embryonic, then can't
213  * do this directly: have to initiate a pru_disconnect(),
214  * which may finish later; embryonic TCB's can just
215  * be discarded here.
216  */
217 static void
218 tcp_usr_detach(netmsg_t msg)
219 {
220 	struct socket *so = msg->base.nm_so;
221 	int error = 0;
222 	struct inpcb *inp;
223 	struct tcpcb *tp;
224 	TCPDEBUG0;
225 
226 	inp = so->so_pcb;
227 
228 	/*
229 	 * If the inp is already detached it may have been due to an async
230 	 * close.  Just return as if no error occured.
231 	 *
232 	 * It's possible for the tcpcb (tp) to disconnect from the inp due
233 	 * to tcp_drop()->tcp_close() being called.  This may occur *after*
234 	 * the detach message has been queued so we may find a NULL tp here.
235 	 */
236 	if (inp) {
237 		if ((tp = intotcpcb(inp)) != NULL) {
238 			TCPDEBUG1();
239 			tp = tcp_disconnect(tp);
240 			TCPDEBUG2(PRU_DETACH);
241 		}
242 	}
243 	lwkt_replymsg(&msg->lmsg, error);
244 }
245 
246 /*
247  * NOTE: ignore_error is non-zero for certain disconnection races
248  * which we want to silently allow, otherwise close() may return
249  * an unexpected error.
250  *
251  * NOTE: The variables (msg) and (tp) are assumed.
252  */
253 #define	COMMON_START(so, inp, ignore_error)			\
254 	TCPDEBUG0; 						\
255 								\
256 	inp = so->so_pcb; 					\
257 	do {							\
258 		 if (inp == NULL) {				\
259 			error = ignore_error ? 0 : EINVAL;	\
260 			tp = NULL;				\
261 			goto out;				\
262 		 }						\
263 		 tp = intotcpcb(inp);				\
264 		 TCPDEBUG1();					\
265 	} while(0)
266 
267 #define COMMON_END1(req, noreply)				\
268 	out: do {						\
269 		TCPDEBUG2(req);					\
270 		if (!(noreply))					\
271 			lwkt_replymsg(&msg->lmsg, error);	\
272 		return;						\
273 	} while(0)
274 
275 #define COMMON_END(req)		COMMON_END1((req), 0)
276 
277 /*
278  * Give the socket an address.
279  */
280 static void
281 tcp_usr_bind(netmsg_t msg)
282 {
283 	struct socket *so = msg->bind.base.nm_so;
284 	struct sockaddr *nam = msg->bind.nm_nam;
285 	struct thread *td = msg->bind.nm_td;
286 	int error = 0;
287 	struct inpcb *inp;
288 	struct tcpcb *tp;
289 	struct sockaddr_in *sinp;
290 
291 	COMMON_START(so, inp, 0);
292 
293 	/*
294 	 * Must check for multicast addresses and disallow binding
295 	 * to them.
296 	 */
297 	sinp = (struct sockaddr_in *)nam;
298 	if (sinp->sin_family == AF_INET &&
299 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
300 		error = EAFNOSUPPORT;
301 		goto out;
302 	}
303 	error = in_pcbbind(inp, nam, td);
304 	if (error)
305 		goto out;
306 	COMMON_END(PRU_BIND);
307 
308 }
309 
310 #ifdef INET6
311 
312 static void
313 tcp6_usr_bind(netmsg_t msg)
314 {
315 	struct socket *so = msg->bind.base.nm_so;
316 	struct sockaddr *nam = msg->bind.nm_nam;
317 	struct thread *td = msg->bind.nm_td;
318 	int error = 0;
319 	struct inpcb *inp;
320 	struct tcpcb *tp;
321 	struct sockaddr_in6 *sin6p;
322 
323 	COMMON_START(so, inp, 0);
324 
325 	/*
326 	 * Must check for multicast addresses and disallow binding
327 	 * to them.
328 	 */
329 	sin6p = (struct sockaddr_in6 *)nam;
330 	if (sin6p->sin6_family == AF_INET6 &&
331 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
332 		error = EAFNOSUPPORT;
333 		goto out;
334 	}
335 	inp->inp_vflag &= ~INP_IPV4;
336 	inp->inp_vflag |= INP_IPV6;
337 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
338 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
339 			inp->inp_vflag |= INP_IPV4;
340 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
341 			struct sockaddr_in sin;
342 
343 			in6_sin6_2_sin(&sin, sin6p);
344 			inp->inp_vflag |= INP_IPV4;
345 			inp->inp_vflag &= ~INP_IPV6;
346 			error = in_pcbbind(inp, (struct sockaddr *)&sin, td);
347 			goto out;
348 		}
349 	}
350 	error = in6_pcbbind(inp, nam, td);
351 	if (error)
352 		goto out;
353 	COMMON_END(PRU_BIND);
354 }
355 #endif /* INET6 */
356 
357 struct netmsg_inswildcard {
358 	struct netmsg_base	base;
359 	struct inpcb		*nm_inp;
360 };
361 
362 static void
363 in_pcbinswildcardhash_handler(netmsg_t msg)
364 {
365 	struct netmsg_inswildcard *nm = (struct netmsg_inswildcard *)msg;
366 	int cpu = mycpuid, nextcpu;
367 
368 	in_pcbinswildcardhash_oncpu(nm->nm_inp, &tcbinfo[cpu]);
369 
370 	nextcpu = cpu + 1;
371 	if (nextcpu < ncpus2)
372 		lwkt_forwardmsg(netisr_cpuport(nextcpu), &nm->base.lmsg);
373 	else
374 		lwkt_replymsg(&nm->base.lmsg, 0);
375 }
376 
377 /*
378  * Prepare to accept connections.
379  */
380 static void
381 tcp_usr_listen(netmsg_t msg)
382 {
383 	struct socket *so = msg->listen.base.nm_so;
384 	struct thread *td = msg->listen.nm_td;
385 	int error = 0;
386 	struct inpcb *inp;
387 	struct tcpcb *tp;
388 	struct netmsg_inswildcard nm;
389 	lwkt_port_t port0 = netisr_cpuport(0);
390 
391 	COMMON_START(so, inp, 0);
392 
393 	if (&curthread->td_msgport != port0) {
394 		KASSERT((msg->listen.nm_flags & PRUL_RELINK) == 0,
395 		    ("already asked to relink"));
396 
397 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpuid]);
398 		sosetport(so, port0);
399 		msg->listen.nm_flags |= PRUL_RELINK;
400 
401 		lwkt_forwardmsg(port0, &msg->listen.base.lmsg);
402 		/* msg invalid now */
403 		return;
404 	}
405 	KASSERT(so->so_port == port0, ("so_port is not netisr0"));
406 
407 	if (msg->listen.nm_flags & PRUL_RELINK) {
408 		msg->listen.nm_flags &= ~PRUL_RELINK;
409 		in_pcblink(so->so_pcb, &tcbinfo[mycpuid]);
410 	}
411 	KASSERT(inp->inp_pcbinfo == &tcbinfo[0], ("pcbinfo is not tcbinfo0"));
412 	KASSERT(inp->inp_cpcbinfo == &tcbinfo[0], ("cpcbinfo is not tcbinfo0"));
413 
414 	if (tp->t_flags & TF_LISTEN)
415 		goto out;
416 
417 	if (inp->inp_lport == 0) {
418 		error = in_pcbbind(inp, NULL, td);
419 		if (error)
420 			goto out;
421 	}
422 
423 	tp->t_state = TCPS_LISTEN;
424 	tp->t_flags |= TF_LISTEN;
425 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
426 
427 	if (ncpus > 1) {
428 		/*
429 		 * We have to set the flag because we can't have other cpus
430 		 * messing with our inp's flags.
431 		 */
432 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
433 			("already on connhash"));
434 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
435 			("already on wildcardhash"));
436 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
437 			("already on MP wildcardhash"));
438 		inp->inp_flags |= INP_WILDCARD_MP;
439 
440 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
441 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
442 		nm.nm_inp = inp;
443 		lwkt_domsg(netisr_cpuport(1), &nm.base.lmsg, 0);
444 	}
445 	in_pcbinswildcardhash(inp);
446 	COMMON_END(PRU_LISTEN);
447 }
448 
449 #ifdef INET6
450 
451 static void
452 tcp6_usr_listen(netmsg_t msg)
453 {
454 	struct socket *so = msg->listen.base.nm_so;
455 	struct thread *td = msg->listen.nm_td;
456 	int error = 0;
457 	struct inpcb *inp;
458 	struct tcpcb *tp;
459 	struct netmsg_inswildcard nm;
460 
461 	COMMON_START(so, inp, 0);
462 
463 	if (tp->t_flags & TF_LISTEN)
464 		goto out;
465 
466 	if (inp->inp_lport == 0) {
467 		if (!(inp->inp_flags & IN6P_IPV6_V6ONLY))
468 			inp->inp_vflag |= INP_IPV4;
469 		else
470 			inp->inp_vflag &= ~INP_IPV4;
471 		error = in6_pcbbind(inp, NULL, td);
472 		if (error)
473 			goto out;
474 	}
475 
476 	tp->t_state = TCPS_LISTEN;
477 	tp->t_flags |= TF_LISTEN;
478 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
479 
480 	if (ncpus > 1) {
481 		/*
482 		 * We have to set the flag because we can't have other cpus
483 		 * messing with our inp's flags.
484 		 */
485 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
486 			("already on connhash"));
487 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
488 			("already on wildcardhash"));
489 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
490 			("already on MP wildcardhash"));
491 		inp->inp_flags |= INP_WILDCARD_MP;
492 
493 		KKASSERT(so->so_port == netisr_cpuport(0));
494 		KKASSERT(&curthread->td_msgport == netisr_cpuport(0));
495 		KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
496 
497 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
498 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
499 		nm.nm_inp = inp;
500 		lwkt_domsg(netisr_cpuport(1), &nm.base.lmsg, 0);
501 	}
502 	in_pcbinswildcardhash(inp);
503 	COMMON_END(PRU_LISTEN);
504 }
505 #endif /* INET6 */
506 
507 /*
508  * Initiate connection to peer.
509  * Create a template for use in transmissions on this connection.
510  * Enter SYN_SENT state, and mark socket as connecting.
511  * Start keep-alive timer, and seed output sequence space.
512  * Send initial segment on connection.
513  */
514 static void
515 tcp_usr_connect(netmsg_t msg)
516 {
517 	struct socket *so = msg->connect.base.nm_so;
518 	struct sockaddr *nam = msg->connect.nm_nam;
519 	struct thread *td = msg->connect.nm_td;
520 	int error = 0;
521 	struct inpcb *inp;
522 	struct tcpcb *tp;
523 	struct sockaddr_in *sinp;
524 
525 	COMMON_START(so, inp, 0);
526 
527 	/*
528 	 * Must disallow TCP ``connections'' to multicast addresses.
529 	 */
530 	sinp = (struct sockaddr_in *)nam;
531 	if (sinp->sin_family == AF_INET
532 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
533 		error = EAFNOSUPPORT;
534 		goto out;
535 	}
536 
537 	if (!prison_remote_ip(td, (struct sockaddr*)sinp)) {
538 		error = EAFNOSUPPORT; /* IPv6 only jail */
539 		goto out;
540 	}
541 
542 	tcp_connect(msg);
543 	/* msg is invalid now */
544 	return;
545 out:
546 	if (msg->connect.nm_m) {
547 		m_freem(msg->connect.nm_m);
548 		msg->connect.nm_m = NULL;
549 	}
550 	if (msg->connect.nm_flags & PRUC_HELDTD)
551 		lwkt_rele(td);
552 	if (error && (msg->connect.nm_flags & PRUC_ASYNC)) {
553 		so->so_error = error;
554 		soisdisconnected(so);
555 	}
556 	lwkt_replymsg(&msg->lmsg, error);
557 }
558 
559 #ifdef INET6
560 
561 static void
562 tcp6_usr_connect(netmsg_t msg)
563 {
564 	struct socket *so = msg->connect.base.nm_so;
565 	struct sockaddr *nam = msg->connect.nm_nam;
566 	struct thread *td = msg->connect.nm_td;
567 	int error = 0;
568 	struct inpcb *inp;
569 	struct tcpcb *tp;
570 	struct sockaddr_in6 *sin6p;
571 
572 	COMMON_START(so, inp, 0);
573 
574 	/*
575 	 * Must disallow TCP ``connections'' to multicast addresses.
576 	 */
577 	sin6p = (struct sockaddr_in6 *)nam;
578 	if (sin6p->sin6_family == AF_INET6
579 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
580 		error = EAFNOSUPPORT;
581 		goto out;
582 	}
583 
584 	if (!prison_remote_ip(td, nam)) {
585 		error = EAFNOSUPPORT; /* IPv4 only jail */
586 		goto out;
587 	}
588 
589 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
590 		struct sockaddr_in *sinp;
591 
592 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
593 			error = EINVAL;
594 			goto out;
595 		}
596 		sinp = kmalloc(sizeof(*sinp), M_LWKTMSG, M_INTWAIT);
597 		in6_sin6_2_sin(sinp, sin6p);
598 		inp->inp_vflag |= INP_IPV4;
599 		inp->inp_vflag &= ~INP_IPV6;
600 		msg->connect.nm_nam = (struct sockaddr *)sinp;
601 		msg->connect.nm_flags |= PRUC_NAMALLOC;
602 		tcp_connect(msg);
603 		/* msg is invalid now */
604 		return;
605 	}
606 	inp->inp_vflag &= ~INP_IPV4;
607 	inp->inp_vflag |= INP_IPV6;
608 	inp->inp_inc.inc_isipv6 = 1;
609 
610 	msg->connect.nm_flags |= PRUC_FALLBACK;
611 	tcp6_connect(msg);
612 	/* msg is invalid now */
613 	return;
614 out:
615 	if (msg->connect.nm_m) {
616 		m_freem(msg->connect.nm_m);
617 		msg->connect.nm_m = NULL;
618 	}
619 	lwkt_replymsg(&msg->lmsg, error);
620 }
621 
622 #endif /* INET6 */
623 
624 /*
625  * Initiate disconnect from peer.
626  * If connection never passed embryonic stage, just drop;
627  * else if don't need to let data drain, then can just drop anyways,
628  * else have to begin TCP shutdown process: mark socket disconnecting,
629  * drain unread data, state switch to reflect user close, and
630  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
631  * when peer sends FIN and acks ours.
632  *
633  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
634  */
635 static void
636 tcp_usr_disconnect(netmsg_t msg)
637 {
638 	struct socket *so = msg->disconnect.base.nm_so;
639 	int error = 0;
640 	struct inpcb *inp;
641 	struct tcpcb *tp;
642 
643 	COMMON_START(so, inp, 1);
644 	tp = tcp_disconnect(tp);
645 	COMMON_END(PRU_DISCONNECT);
646 }
647 
648 /*
649  * Accept a connection.  Essentially all the work is
650  * done at higher levels; just return the address
651  * of the peer, storing through addr.
652  */
653 static void
654 tcp_usr_accept(netmsg_t msg)
655 {
656 	struct socket *so = msg->accept.base.nm_so;
657 	struct sockaddr **nam = msg->accept.nm_nam;
658 	int error = 0;
659 	struct inpcb *inp;
660 	struct tcpcb *tp = NULL;
661 	TCPDEBUG0;
662 
663 	inp = so->so_pcb;
664 	if (so->so_state & SS_ISDISCONNECTED) {
665 		error = ECONNABORTED;
666 		goto out;
667 	}
668 	if (inp == 0) {
669 		error = EINVAL;
670 		goto out;
671 	}
672 
673 	tp = intotcpcb(inp);
674 	TCPDEBUG1();
675 	in_setpeeraddr(so, nam);
676 	COMMON_END(PRU_ACCEPT);
677 }
678 
679 #ifdef INET6
680 static void
681 tcp6_usr_accept(netmsg_t msg)
682 {
683 	struct socket *so = msg->accept.base.nm_so;
684 	struct sockaddr **nam = msg->accept.nm_nam;
685 	int error = 0;
686 	struct inpcb *inp;
687 	struct tcpcb *tp = NULL;
688 	TCPDEBUG0;
689 
690 	inp = so->so_pcb;
691 
692 	if (so->so_state & SS_ISDISCONNECTED) {
693 		error = ECONNABORTED;
694 		goto out;
695 	}
696 	if (inp == 0) {
697 		error = EINVAL;
698 		goto out;
699 	}
700 	tp = intotcpcb(inp);
701 	TCPDEBUG1();
702 	in6_mapped_peeraddr(so, nam);
703 	COMMON_END(PRU_ACCEPT);
704 }
705 #endif /* INET6 */
706 /*
707  * Mark the connection as being incapable of further output.
708  */
709 static void
710 tcp_usr_shutdown(netmsg_t msg)
711 {
712 	struct socket *so = msg->shutdown.base.nm_so;
713 	int error = 0;
714 	struct inpcb *inp;
715 	struct tcpcb *tp;
716 
717 	COMMON_START(so, inp, 0);
718 	socantsendmore(so);
719 	tp = tcp_usrclosed(tp);
720 	if (tp)
721 		error = tcp_output(tp);
722 	COMMON_END(PRU_SHUTDOWN);
723 }
724 
725 /*
726  * After a receive, possibly send window update to peer.
727  */
728 static void
729 tcp_usr_rcvd(netmsg_t msg)
730 {
731 	struct socket *so = msg->rcvd.base.nm_so;
732 	int error = 0, noreply = 0;
733 	struct inpcb *inp;
734 	struct tcpcb *tp;
735 
736 	COMMON_START(so, inp, 0);
737 
738 	if (msg->rcvd.nm_pru_flags & PRUR_ASYNC) {
739 		noreply = 1;
740 		so_async_rcvd_reply(so);
741 	}
742 	tcp_output(tp);
743 
744 	COMMON_END1(PRU_RCVD, noreply);
745 }
746 
747 /*
748  * Do a send by putting data in output queue and updating urgent
749  * marker if URG set.  Possibly send more data.  Unlike the other
750  * pru_*() routines, the mbuf chains are our responsibility.  We
751  * must either enqueue them or free them.  The other pru_* routines
752  * generally are caller-frees.
753  */
754 static void
755 tcp_usr_send(netmsg_t msg)
756 {
757 	struct socket *so = msg->send.base.nm_so;
758 	int flags = msg->send.nm_flags;
759 	struct mbuf *m = msg->send.nm_m;
760 	int error = 0;
761 	struct inpcb *inp;
762 	struct tcpcb *tp;
763 	TCPDEBUG0;
764 
765 	KKASSERT(msg->send.nm_control == NULL);
766 	KKASSERT(msg->send.nm_addr == NULL);
767 	KKASSERT((flags & PRUS_FREEADDR) == 0);
768 
769 	inp = so->so_pcb;
770 
771 	if (inp == NULL) {
772 		/*
773 		 * OOPS! we lost a race, the TCP session got reset after
774 		 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a
775 		 * network interrupt in the non-critical section of sosend().
776 		 */
777 		m_freem(m);
778 		error = ECONNRESET;	/* XXX EPIPE? */
779 		tp = NULL;
780 		TCPDEBUG1();
781 		goto out;
782 	}
783 	tp = intotcpcb(inp);
784 	TCPDEBUG1();
785 
786 #ifdef foo
787 	/*
788 	 * This is no longer necessary, since:
789 	 * - sosendtcp() has already checked it for us
790 	 * - It does not work with asynchronized send
791 	 */
792 
793 	/*
794 	 * Don't let too much OOB data build up
795 	 */
796 	if (flags & PRUS_OOB) {
797 		if (ssb_space(&so->so_snd) < -512) {
798 			m_freem(m);
799 			error = ENOBUFS;
800 			goto out;
801 		}
802 	}
803 #endif
804 
805 	/*
806 	 * Pump the data into the socket.
807 	 */
808 	if (m)
809 		ssb_appendstream(&so->so_snd, m);
810 	if (flags & PRUS_OOB) {
811 		/*
812 		 * According to RFC961 (Assigned Protocols),
813 		 * the urgent pointer points to the last octet
814 		 * of urgent data.  We continue, however,
815 		 * to consider it to indicate the first octet
816 		 * of data past the urgent section.
817 		 * Otherwise, snd_up should be one lower.
818 		 */
819 		tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
820 		tp->t_flags |= TF_FORCE;
821 		error = tcp_output(tp);
822 		tp->t_flags &= ~TF_FORCE;
823 	} else {
824 		if (flags & PRUS_EOF) {
825 			/*
826 			 * Close the send side of the connection after
827 			 * the data is sent.
828 			 */
829 			socantsendmore(so);
830 			tp = tcp_usrclosed(tp);
831 		}
832 		if (tp != NULL && !tcp_output_pending(tp)) {
833 			if (flags & PRUS_MORETOCOME)
834 				tp->t_flags |= TF_MORETOCOME;
835 			error = tcp_output_fair(tp);
836 			if (flags & PRUS_MORETOCOME)
837 				tp->t_flags &= ~TF_MORETOCOME;
838 		}
839 	}
840 	COMMON_END1((flags & PRUS_OOB) ? PRU_SENDOOB :
841 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND),
842 		   (flags & PRUS_NOREPLY));
843 }
844 
845 /*
846  * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
847  *	 will sofree() it when we return.
848  */
849 static void
850 tcp_usr_abort(netmsg_t msg)
851 {
852 	struct socket *so = msg->abort.base.nm_so;
853 	int error = 0;
854 	struct inpcb *inp;
855 	struct tcpcb *tp;
856 
857 	COMMON_START(so, inp, 1);
858 	tp = tcp_drop(tp, ECONNABORTED);
859 	COMMON_END(PRU_ABORT);
860 }
861 
862 /*
863  * Receive out-of-band data.
864  */
865 static void
866 tcp_usr_rcvoob(netmsg_t msg)
867 {
868 	struct socket *so = msg->rcvoob.base.nm_so;
869 	struct mbuf *m = msg->rcvoob.nm_m;
870 	int flags = msg->rcvoob.nm_flags;
871 	int error = 0;
872 	struct inpcb *inp;
873 	struct tcpcb *tp;
874 
875 	COMMON_START(so, inp, 0);
876 	if ((so->so_oobmark == 0 &&
877 	     (so->so_state & SS_RCVATMARK) == 0) ||
878 	    so->so_options & SO_OOBINLINE ||
879 	    tp->t_oobflags & TCPOOB_HADDATA) {
880 		error = EINVAL;
881 		goto out;
882 	}
883 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
884 		error = EWOULDBLOCK;
885 		goto out;
886 	}
887 	m->m_len = 1;
888 	*mtod(m, caddr_t) = tp->t_iobc;
889 	if ((flags & MSG_PEEK) == 0)
890 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
891 	COMMON_END(PRU_RCVOOB);
892 }
893 
894 static void
895 tcp_usr_savefaddr(struct socket *so, const struct sockaddr *faddr)
896 {
897 	in_savefaddr(so, faddr);
898 }
899 
900 #ifdef INET6
901 static void
902 tcp6_usr_savefaddr(struct socket *so, const struct sockaddr *faddr)
903 {
904 	in6_mapped_savefaddr(so, faddr);
905 }
906 #endif
907 
908 static int
909 tcp_usr_preconnect(struct socket *so, const struct sockaddr *nam,
910     struct thread *td __unused)
911 {
912 	const struct sockaddr_in *sinp;
913 
914 	sinp = (const struct sockaddr_in *)nam;
915 	if (sinp->sin_family == AF_INET &&
916 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
917 		return EAFNOSUPPORT;
918 
919 	soisconnecting(so);
920 	return 0;
921 }
922 
923 /* xxx - should be const */
924 struct pr_usrreqs tcp_usrreqs = {
925 	.pru_abort = tcp_usr_abort,
926 	.pru_accept = tcp_usr_accept,
927 	.pru_attach = tcp_usr_attach,
928 	.pru_bind = tcp_usr_bind,
929 	.pru_connect = tcp_usr_connect,
930 	.pru_connect2 = pr_generic_notsupp,
931 	.pru_control = in_control_dispatch,
932 	.pru_detach = tcp_usr_detach,
933 	.pru_disconnect = tcp_usr_disconnect,
934 	.pru_listen = tcp_usr_listen,
935 	.pru_peeraddr = in_setpeeraddr_dispatch,
936 	.pru_rcvd = tcp_usr_rcvd,
937 	.pru_rcvoob = tcp_usr_rcvoob,
938 	.pru_send = tcp_usr_send,
939 	.pru_sense = pru_sense_null,
940 	.pru_shutdown = tcp_usr_shutdown,
941 	.pru_sockaddr = in_setsockaddr_dispatch,
942 	.pru_sosend = sosendtcp,
943 	.pru_soreceive = sorecvtcp,
944 	.pru_savefaddr = tcp_usr_savefaddr,
945 	.pru_preconnect = tcp_usr_preconnect
946 };
947 
948 #ifdef INET6
949 struct pr_usrreqs tcp6_usrreqs = {
950 	.pru_abort = tcp_usr_abort,
951 	.pru_accept = tcp6_usr_accept,
952 	.pru_attach = tcp_usr_attach,
953 	.pru_bind = tcp6_usr_bind,
954 	.pru_connect = tcp6_usr_connect,
955 	.pru_connect2 = pr_generic_notsupp,
956 	.pru_control = in6_control_dispatch,
957 	.pru_detach = tcp_usr_detach,
958 	.pru_disconnect = tcp_usr_disconnect,
959 	.pru_listen = tcp6_usr_listen,
960 	.pru_peeraddr = in6_mapped_peeraddr_dispatch,
961 	.pru_rcvd = tcp_usr_rcvd,
962 	.pru_rcvoob = tcp_usr_rcvoob,
963 	.pru_send = tcp_usr_send,
964 	.pru_sense = pru_sense_null,
965 	.pru_shutdown = tcp_usr_shutdown,
966 	.pru_sockaddr = in6_mapped_sockaddr_dispatch,
967 	.pru_sosend = sosendtcp,
968 	.pru_soreceive = sorecvtcp,
969 	.pru_savefaddr = tcp6_usr_savefaddr
970 };
971 #endif /* INET6 */
972 
973 static int
974 tcp_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf *m,
975 		  struct sockaddr_in *sin, struct sockaddr_in *if_sin)
976 {
977 	struct inpcb *inp = tp->t_inpcb, *oinp;
978 	struct socket *so = inp->inp_socket;
979 	struct route *ro = &inp->inp_route;
980 
981 	KASSERT(inp->inp_cpcbinfo == &tcbinfo[mycpu->gd_cpuid],
982 	    ("cpcbinfo mismatch"));
983 
984 	oinp = in_pcblookup_hash(inp->inp_cpcbinfo,
985 				 sin->sin_addr, sin->sin_port,
986 				 (inp->inp_laddr.s_addr != INADDR_ANY ?
987 				  inp->inp_laddr : if_sin->sin_addr),
988 				inp->inp_lport, 0, NULL);
989 	if (oinp != NULL) {
990 		m_freem(m);
991 		return (EADDRINUSE);
992 	}
993 	if (inp->inp_laddr.s_addr == INADDR_ANY)
994 		inp->inp_laddr = if_sin->sin_addr;
995 	inp->inp_faddr = sin->sin_addr;
996 	inp->inp_fport = sin->sin_port;
997 	in_pcbinsconnhash(inp);
998 
999 	/*
1000 	 * We are now on the inpcb's owner CPU, if the cached route was
1001 	 * freed because the rtentry's owner CPU is not the current CPU
1002 	 * (e.g. in tcp_connect()), then we try to reallocate it here with
1003 	 * the hope that a rtentry may be cloned from a RTF_PRCLONING
1004 	 * rtentry.
1005 	 */
1006 	if (!(inp->inp_socket->so_options & SO_DONTROUTE) && /*XXX*/
1007 	    ro->ro_rt == NULL) {
1008 		bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
1009 		ro->ro_dst.sa_family = AF_INET;
1010 		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
1011 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr =
1012 			sin->sin_addr;
1013 		rtalloc(ro);
1014 	}
1015 
1016 	/*
1017 	 * Now that no more errors can occur, change the protocol processing
1018 	 * port to the current thread (which is the correct thread).
1019 	 *
1020 	 * Create TCP timer message now; we are on the tcpcb's owner
1021 	 * CPU/thread.
1022 	 */
1023 	tcp_create_timermsg(tp, &curthread->td_msgport);
1024 
1025 	/*
1026 	 * Compute window scaling to request.  Use a larger scaling then
1027 	 * needed for the initial receive buffer in case the receive buffer
1028 	 * gets expanded.
1029 	 */
1030 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1031 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1032 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1033 	       (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat
1034 	) {
1035 		tp->request_r_scale++;
1036 	}
1037 
1038 	soisconnecting(so);
1039 	tcpstat.tcps_connattempt++;
1040 	tp->t_state = TCPS_SYN_SENT;
1041 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1042 	tp->iss = tcp_new_isn(tp);
1043 	tcp_sendseqinit(tp);
1044 	if (m) {
1045 		ssb_appendstream(&so->so_snd, m);
1046 		m = NULL;
1047 		if (flags & PRUS_OOB)
1048 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1049 	}
1050 
1051 	/*
1052 	 * Close the send side of the connection after
1053 	 * the data is sent if flagged.
1054 	 */
1055 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1056 		socantsendmore(so);
1057 		tp = tcp_usrclosed(tp);
1058 	}
1059 	return (tcp_output(tp));
1060 }
1061 
1062 /*
1063  * Common subroutine to open a TCP connection to remote host specified
1064  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1065  * port number if needed.  Call in_pcbladdr to do the routing and to choose
1066  * a local host address (interface).
1067  * Initialize connection parameters and enter SYN-SENT state.
1068  */
1069 static void
1070 tcp_connect(netmsg_t msg)
1071 {
1072 	struct socket *so = msg->connect.base.nm_so;
1073 	struct sockaddr *nam = msg->connect.nm_nam;
1074 	struct thread *td = msg->connect.nm_td;
1075 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
1076 	struct sockaddr_in *if_sin;
1077 	struct inpcb *inp;
1078 	struct tcpcb *tp;
1079 	int error, calc_laddr = 1;
1080 	lwkt_port_t port;
1081 
1082 	COMMON_START(so, inp, 0);
1083 
1084 	/*
1085 	 * Reconnect our pcb if we have to
1086 	 */
1087 	if (msg->connect.nm_flags & PRUC_RECONNECT) {
1088 		msg->connect.nm_flags &= ~PRUC_RECONNECT;
1089 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1090 	}
1091 
1092 	/*
1093 	 * Bind if we have to
1094 	 */
1095 	if (inp->inp_lport == 0) {
1096 		if (tcp_lport_extension) {
1097 			KKASSERT(inp->inp_laddr.s_addr == INADDR_ANY);
1098 
1099 			error = in_pcbladdr(inp, nam, &if_sin, td);
1100 			if (error)
1101 				goto out;
1102 			inp->inp_laddr.s_addr = if_sin->sin_addr.s_addr;
1103 
1104 			error = in_pcbsetlport_remote(inp, nam, td);
1105 			if (error)
1106 				goto out;
1107 
1108 			calc_laddr = 0;
1109 		} else {
1110 			error = in_pcbbind(inp, NULL, td);
1111 			if (error)
1112 				goto out;
1113 		}
1114 	}
1115 
1116 	if (calc_laddr) {
1117 		/*
1118 		 * Calculate the correct protocol processing thread.  The
1119 		 * connect operation must run there.  Set the forwarding
1120 		 * port before we forward the message or it will get bounced
1121 		 * right back to us.
1122 		 */
1123 		error = in_pcbladdr(inp, nam, &if_sin, td);
1124 		if (error)
1125 			goto out;
1126 	}
1127 	KKASSERT(inp->inp_socket == so);
1128 
1129 	port = tcp_addrport(sin->sin_addr.s_addr, sin->sin_port,
1130 			    (inp->inp_laddr.s_addr ?
1131 			     inp->inp_laddr.s_addr : if_sin->sin_addr.s_addr),
1132 			    inp->inp_lport);
1133 
1134 	if (port != &curthread->td_msgport) {
1135 		struct route *ro = &inp->inp_route;
1136 
1137 		/*
1138 		 * in_pcbladdr() may have allocated a route entry for us
1139 		 * on the current CPU, but we need a route entry on the
1140 		 * inpcb's owner CPU, so free it here.
1141 		 */
1142 		if (ro->ro_rt != NULL)
1143 			RTFREE(ro->ro_rt);
1144 		bzero(ro, sizeof(*ro));
1145 
1146 		/*
1147 		 * We are moving the protocol processing port the socket
1148 		 * is on, we have to unlink here and re-link on the
1149 		 * target cpu.
1150 		 */
1151 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1152 		sosetport(so, port);
1153 		msg->connect.nm_flags |= PRUC_RECONNECT;
1154 		msg->connect.base.nm_dispatch = tcp_connect;
1155 
1156 		lwkt_forwardmsg(port, &msg->connect.base.lmsg);
1157 		/* msg invalid now */
1158 		return;
1159 	} else if (msg->connect.nm_flags & PRUC_HELDTD) {
1160 		/*
1161 		 * The original thread is no longer needed; release it.
1162 		 */
1163 		lwkt_rele(td);
1164 		msg->connect.nm_flags &= ~PRUC_HELDTD;
1165 	}
1166 	error = tcp_connect_oncpu(tp, msg->connect.nm_sndflags,
1167 				  msg->connect.nm_m, sin, if_sin);
1168 	msg->connect.nm_m = NULL;
1169 out:
1170 	if (msg->connect.nm_m) {
1171 		m_freem(msg->connect.nm_m);
1172 		msg->connect.nm_m = NULL;
1173 	}
1174 	if (msg->connect.nm_flags & PRUC_NAMALLOC) {
1175 		kfree(msg->connect.nm_nam, M_LWKTMSG);
1176 		msg->connect.nm_nam = NULL;
1177 	}
1178 	if (msg->connect.nm_flags & PRUC_HELDTD)
1179 		lwkt_rele(td);
1180 	if (error && (msg->connect.nm_flags & PRUC_ASYNC)) {
1181 		so->so_error = error;
1182 		soisdisconnected(so);
1183 	}
1184 	lwkt_replymsg(&msg->connect.base.lmsg, error);
1185 	/* msg invalid now */
1186 }
1187 
1188 #ifdef INET6
1189 
1190 static void
1191 tcp6_connect(netmsg_t msg)
1192 {
1193 	struct tcpcb *tp;
1194 	struct socket *so = msg->connect.base.nm_so;
1195 	struct sockaddr *nam = msg->connect.nm_nam;
1196 	struct thread *td = msg->connect.nm_td;
1197 	struct inpcb *inp;
1198 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1199 	struct in6_addr *addr6;
1200 	lwkt_port_t port;
1201 	int error;
1202 
1203 	COMMON_START(so, inp, 0);
1204 
1205 	/*
1206 	 * Reconnect our pcb if we have to
1207 	 */
1208 	if (msg->connect.nm_flags & PRUC_RECONNECT) {
1209 		msg->connect.nm_flags &= ~PRUC_RECONNECT;
1210 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1211 	}
1212 
1213 	/*
1214 	 * Bind if we have to
1215 	 */
1216 	if (inp->inp_lport == 0) {
1217 		error = in6_pcbbind(inp, NULL, td);
1218 		if (error)
1219 			goto out;
1220 	}
1221 
1222 	/*
1223 	 * Cannot simply call in_pcbconnect, because there might be an
1224 	 * earlier incarnation of this same connection still in
1225 	 * TIME_WAIT state, creating an ADDRINUSE error.
1226 	 */
1227 	error = in6_pcbladdr(inp, nam, &addr6, td);
1228 	if (error)
1229 		goto out;
1230 
1231 	port = tcp6_addrport();	/* XXX hack for now, always cpu0 */
1232 
1233 	if (port != &curthread->td_msgport) {
1234 		struct route *ro = &inp->inp_route;
1235 
1236 		/*
1237 		 * in_pcbladdr() may have allocated a route entry for us
1238 		 * on the current CPU, but we need a route entry on the
1239 		 * inpcb's owner CPU, so free it here.
1240 		 */
1241 		if (ro->ro_rt != NULL)
1242 			RTFREE(ro->ro_rt);
1243 		bzero(ro, sizeof(*ro));
1244 
1245 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1246 		sosetport(so, port);
1247 		msg->connect.nm_flags |= PRUC_RECONNECT;
1248 		msg->connect.base.nm_dispatch = tcp6_connect;
1249 
1250 		lwkt_forwardmsg(port, &msg->connect.base.lmsg);
1251 		/* msg invalid now */
1252 		return;
1253 	}
1254 	error = tcp6_connect_oncpu(tp, msg->connect.nm_sndflags,
1255 				   &msg->connect.nm_m, sin6, addr6);
1256 	/* nm_m may still be intact */
1257 out:
1258 	if (error && (msg->connect.nm_flags & PRUC_FALLBACK)) {
1259 		tcp_connect(msg);
1260 		/* msg invalid now */
1261 	} else {
1262 		if (msg->connect.nm_m) {
1263 			m_freem(msg->connect.nm_m);
1264 			msg->connect.nm_m = NULL;
1265 		}
1266 		if (msg->connect.nm_flags & PRUC_NAMALLOC) {
1267 			kfree(msg->connect.nm_nam, M_LWKTMSG);
1268 			msg->connect.nm_nam = NULL;
1269 		}
1270 		lwkt_replymsg(&msg->connect.base.lmsg, error);
1271 		/* msg invalid now */
1272 	}
1273 }
1274 
1275 static int
1276 tcp6_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf **mp,
1277 		   struct sockaddr_in6 *sin6, struct in6_addr *addr6)
1278 {
1279 	struct mbuf *m = *mp;
1280 	struct inpcb *inp = tp->t_inpcb;
1281 	struct socket *so = inp->inp_socket;
1282 	struct inpcb *oinp;
1283 
1284 	/*
1285 	 * Cannot simply call in_pcbconnect, because there might be an
1286 	 * earlier incarnation of this same connection still in
1287 	 * TIME_WAIT state, creating an ADDRINUSE error.
1288 	 */
1289 	oinp = in6_pcblookup_hash(inp->inp_cpcbinfo,
1290 				  &sin6->sin6_addr, sin6->sin6_port,
1291 				  (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ?
1292 				      addr6 : &inp->in6p_laddr),
1293 				  inp->inp_lport,  0, NULL);
1294 	if (oinp)
1295 		return (EADDRINUSE);
1296 
1297 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1298 		inp->in6p_laddr = *addr6;
1299 	inp->in6p_faddr = sin6->sin6_addr;
1300 	inp->inp_fport = sin6->sin6_port;
1301 	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != 0)
1302 		inp->in6p_flowinfo = sin6->sin6_flowinfo;
1303 	in_pcbinsconnhash(inp);
1304 
1305 	/*
1306 	 * Now that no more errors can occur, change the protocol processing
1307 	 * port to the current thread (which is the correct thread).
1308 	 *
1309 	 * Create TCP timer message now; we are on the tcpcb's owner
1310 	 * CPU/thread.
1311 	 */
1312 	tcp_create_timermsg(tp, &curthread->td_msgport);
1313 
1314 	/* Compute window scaling to request.  */
1315 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1316 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1317 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1318 	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat) {
1319 		tp->request_r_scale++;
1320 	}
1321 
1322 	soisconnecting(so);
1323 	tcpstat.tcps_connattempt++;
1324 	tp->t_state = TCPS_SYN_SENT;
1325 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1326 	tp->iss = tcp_new_isn(tp);
1327 	tcp_sendseqinit(tp);
1328 	if (m) {
1329 		ssb_appendstream(&so->so_snd, m);
1330 		*mp = NULL;
1331 		if (flags & PRUS_OOB)
1332 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1333 	}
1334 
1335 	/*
1336 	 * Close the send side of the connection after
1337 	 * the data is sent if flagged.
1338 	 */
1339 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1340 		socantsendmore(so);
1341 		tp = tcp_usrclosed(tp);
1342 	}
1343 	return (tcp_output(tp));
1344 }
1345 
1346 #endif /* INET6 */
1347 
1348 /*
1349  * The new sockopt interface makes it possible for us to block in the
1350  * copyin/out step (if we take a page fault).  Taking a page fault while
1351  * in a critical section is probably a Bad Thing.  (Since sockets and pcbs
1352  * both now use TSM, there probably isn't any need for this function to
1353  * run in a critical section any more.  This needs more examination.)
1354  */
1355 void
1356 tcp_ctloutput(netmsg_t msg)
1357 {
1358 	struct socket *so = msg->base.nm_so;
1359 	struct sockopt *sopt = msg->ctloutput.nm_sopt;
1360 	int	error, opt, optval, opthz;
1361 	struct	inpcb *inp;
1362 	struct	tcpcb *tp;
1363 
1364 	error = 0;
1365 	inp = so->so_pcb;
1366 	if (inp == NULL) {
1367 		error = ECONNRESET;
1368 		goto done;
1369 	}
1370 
1371 	if (sopt->sopt_level != IPPROTO_TCP) {
1372 #ifdef INET6
1373 		if (INP_CHECK_SOCKAF(so, AF_INET6))
1374 			ip6_ctloutput_dispatch(msg);
1375 		else
1376 #endif /* INET6 */
1377 		ip_ctloutput(msg);
1378 		/* msg invalid now */
1379 		return;
1380 	}
1381 	tp = intotcpcb(inp);
1382 
1383 	switch (sopt->sopt_dir) {
1384 	case SOPT_SET:
1385 		error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1386 				      sizeof optval);
1387 		if (error)
1388 			break;
1389 		switch (sopt->sopt_name) {
1390 		case TCP_FASTKEEP:
1391 			if (optval > 0)
1392 				tp->t_keepidle = tp->t_keepintvl;
1393 			else
1394 				tp->t_keepidle = tcp_keepidle;
1395 			tcp_timer_keep_activity(tp, 0);
1396 			break;
1397 #ifdef TCP_SIGNATURE
1398 		case TCP_SIGNATURE_ENABLE:
1399 			if (tp->t_state == TCPS_CLOSED) {
1400 				/*
1401 				 * This is the only safe state that this
1402 				 * option could be changed.  Some segments
1403 				 * could already have been sent in other
1404 				 * states.
1405 				 */
1406 				if (optval > 0)
1407 					tp->t_flags |= TF_SIGNATURE;
1408 				else
1409 					tp->t_flags &= ~TF_SIGNATURE;
1410 			} else {
1411 				error = EOPNOTSUPP;
1412 			}
1413 			break;
1414 #endif /* TCP_SIGNATURE */
1415 		case TCP_NODELAY:
1416 		case TCP_NOOPT:
1417 			switch (sopt->sopt_name) {
1418 			case TCP_NODELAY:
1419 				opt = TF_NODELAY;
1420 				break;
1421 			case TCP_NOOPT:
1422 				opt = TF_NOOPT;
1423 				break;
1424 			default:
1425 				opt = 0; /* dead code to fool gcc */
1426 				break;
1427 			}
1428 
1429 			if (optval)
1430 				tp->t_flags |= opt;
1431 			else
1432 				tp->t_flags &= ~opt;
1433 			break;
1434 
1435 		case TCP_NOPUSH:
1436 			if (tcp_disable_nopush)
1437 				break;
1438 			if (optval)
1439 				tp->t_flags |= TF_NOPUSH;
1440 			else {
1441 				tp->t_flags &= ~TF_NOPUSH;
1442 				error = tcp_output(tp);
1443 			}
1444 			break;
1445 
1446 		case TCP_MAXSEG:
1447 			/*
1448 			 * Must be between 0 and maxseg.  If the requested
1449 			 * maxseg is too small to satisfy the desired minmss,
1450 			 * pump it up (silently so sysctl modifications of
1451 			 * minmss do not create unexpected program failures).
1452 			 * Handle degenerate cases.
1453 			 */
1454 			if (optval > 0 && optval <= tp->t_maxseg) {
1455 				if (optval + 40 < tcp_minmss) {
1456 					optval = tcp_minmss - 40;
1457 					if (optval < 0)
1458 						optval = 1;
1459 				}
1460 				tp->t_maxseg = optval;
1461 			} else {
1462 				error = EINVAL;
1463 			}
1464 			break;
1465 
1466 		case TCP_KEEPINIT:
1467 			opthz = ((int64_t)optval * hz) / 1000;
1468 			if (opthz >= 1)
1469 				tp->t_keepinit = opthz;
1470 			else
1471 				error = EINVAL;
1472 			break;
1473 
1474 		case TCP_KEEPIDLE:
1475 			opthz = ((int64_t)optval * hz) / 1000;
1476 			if (opthz >= 1) {
1477 				tp->t_keepidle = opthz;
1478 				tcp_timer_keep_activity(tp, 0);
1479 			} else {
1480 				error = EINVAL;
1481 			}
1482 			break;
1483 
1484 		case TCP_KEEPINTVL:
1485 			opthz = ((int64_t)optval * hz) / 1000;
1486 			if (opthz >= 1) {
1487 				tp->t_keepintvl = opthz;
1488 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1489 			} else {
1490 				error = EINVAL;
1491 			}
1492 			break;
1493 
1494 		case TCP_KEEPCNT:
1495 			if (optval > 0) {
1496 				tp->t_keepcnt = optval;
1497 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1498 			} else {
1499 				error = EINVAL;
1500 			}
1501 			break;
1502 
1503 		default:
1504 			error = ENOPROTOOPT;
1505 			break;
1506 		}
1507 		break;
1508 
1509 	case SOPT_GET:
1510 		switch (sopt->sopt_name) {
1511 #ifdef TCP_SIGNATURE
1512 		case TCP_SIGNATURE_ENABLE:
1513 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1514 			break;
1515 #endif /* TCP_SIGNATURE */
1516 		case TCP_NODELAY:
1517 			optval = tp->t_flags & TF_NODELAY;
1518 			break;
1519 		case TCP_MAXSEG:
1520 			optval = tp->t_maxseg;
1521 			break;
1522 		case TCP_NOOPT:
1523 			optval = tp->t_flags & TF_NOOPT;
1524 			break;
1525 		case TCP_NOPUSH:
1526 			optval = tp->t_flags & TF_NOPUSH;
1527 			break;
1528 		case TCP_KEEPINIT:
1529 			optval = ((int64_t)tp->t_keepinit * 1000) / hz;
1530 			break;
1531 		case TCP_KEEPIDLE:
1532 			optval = ((int64_t)tp->t_keepidle * 1000) / hz;
1533 			break;
1534 		case TCP_KEEPINTVL:
1535 			optval = ((int64_t)tp->t_keepintvl * 1000) / hz;
1536 			break;
1537 		case TCP_KEEPCNT:
1538 			optval = tp->t_keepcnt;
1539 			break;
1540 		default:
1541 			error = ENOPROTOOPT;
1542 			break;
1543 		}
1544 		if (error == 0)
1545 			soopt_from_kbuf(sopt, &optval, sizeof optval);
1546 		break;
1547 	}
1548 done:
1549 	lwkt_replymsg(&msg->lmsg, error);
1550 }
1551 
1552 /*
1553  * tcp_sendspace and tcp_recvspace are the default send and receive window
1554  * sizes, respectively.  These are obsolescent (this information should
1555  * be set by the route).
1556  *
1557  * Use a default that does not require tcp window scaling to be turned
1558  * on.  Individual programs or the administrator can increase the default.
1559  */
1560 u_long	tcp_sendspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1561 SYSCTL_INT(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1562     &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1563 u_long	tcp_recvspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1564 SYSCTL_INT(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1565     &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1566 
1567 /*
1568  * Attach TCP protocol to socket, allocating internet protocol control
1569  * block, tcp control block, buffer space, and entering CLOSED state.
1570  */
1571 static int
1572 tcp_attach(struct socket *so, struct pru_attach_info *ai)
1573 {
1574 	struct tcpcb *tp;
1575 	struct inpcb *inp;
1576 	int error;
1577 	int cpu;
1578 #ifdef INET6
1579 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
1580 #endif
1581 
1582 	if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
1583 		lwkt_gettoken(&so->so_rcv.ssb_token);
1584 		error = soreserve(so, tcp_sendspace, tcp_recvspace,
1585 				  ai->sb_rlimit);
1586 		lwkt_reltoken(&so->so_rcv.ssb_token);
1587 		if (error)
1588 			return (error);
1589 	}
1590 	atomic_set_int(&so->so_rcv.ssb_flags, SSB_AUTOSIZE);
1591 	atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOSIZE);
1592 	cpu = mycpu->gd_cpuid;
1593 
1594 	/*
1595 	 * Set the default port for protocol processing. This will likely
1596 	 * change when we connect.
1597 	 */
1598 	error = in_pcballoc(so, &tcbinfo[cpu]);
1599 	if (error)
1600 		return (error);
1601 	inp = so->so_pcb;
1602 #ifdef INET6
1603 	if (isipv6) {
1604 		inp->inp_vflag |= INP_IPV6;
1605 		inp->in6p_hops = -1;	/* use kernel default */
1606 	}
1607 	else
1608 #endif
1609 	inp->inp_vflag |= INP_IPV4;
1610 	tp = tcp_newtcpcb(inp);
1611 	if (tp == NULL) {
1612 		/*
1613 		 * Make sure the socket is destroyed by the pcbdetach.
1614 		 */
1615 		soreference(so);
1616 #ifdef INET6
1617 		if (isipv6)
1618 			in6_pcbdetach(inp);
1619 		else
1620 #endif
1621 		in_pcbdetach(inp);
1622 		sofree(so);	/* from ref above */
1623 		return (ENOBUFS);
1624 	}
1625 	tp->t_state = TCPS_CLOSED;
1626 	/* Keep a reference for asynchronized pru_rcvd */
1627 	soreference(so);
1628 	return (0);
1629 }
1630 
1631 /*
1632  * Initiate (or continue) disconnect.
1633  * If embryonic state, just send reset (once).
1634  * If in ``let data drain'' option and linger null, just drop.
1635  * Otherwise (hard), mark socket disconnecting and drop
1636  * current input data; switch states based on user close, and
1637  * send segment to peer (with FIN).
1638  */
1639 static struct tcpcb *
1640 tcp_disconnect(struct tcpcb *tp)
1641 {
1642 	struct socket *so = tp->t_inpcb->inp_socket;
1643 
1644 	if (tp->t_state < TCPS_ESTABLISHED) {
1645 		tp = tcp_close(tp);
1646 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1647 		tp = tcp_drop(tp, 0);
1648 	} else {
1649 		lwkt_gettoken(&so->so_rcv.ssb_token);
1650 		soisdisconnecting(so);
1651 		sbflush(&so->so_rcv.sb);
1652 		tp = tcp_usrclosed(tp);
1653 		if (tp)
1654 			tcp_output(tp);
1655 		lwkt_reltoken(&so->so_rcv.ssb_token);
1656 	}
1657 	return (tp);
1658 }
1659 
1660 /*
1661  * User issued close, and wish to trail through shutdown states:
1662  * if never received SYN, just forget it.  If got a SYN from peer,
1663  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1664  * If already got a FIN from peer, then almost done; go to LAST_ACK
1665  * state.  In all other cases, have already sent FIN to peer (e.g.
1666  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1667  * for peer to send FIN or not respond to keep-alives, etc.
1668  * We can let the user exit from the close as soon as the FIN is acked.
1669  */
1670 static struct tcpcb *
1671 tcp_usrclosed(struct tcpcb *tp)
1672 {
1673 
1674 	switch (tp->t_state) {
1675 
1676 	case TCPS_CLOSED:
1677 	case TCPS_LISTEN:
1678 		tp->t_state = TCPS_CLOSED;
1679 		tp = tcp_close(tp);
1680 		break;
1681 
1682 	case TCPS_SYN_SENT:
1683 	case TCPS_SYN_RECEIVED:
1684 		tp->t_flags |= TF_NEEDFIN;
1685 		break;
1686 
1687 	case TCPS_ESTABLISHED:
1688 		tp->t_state = TCPS_FIN_WAIT_1;
1689 		break;
1690 
1691 	case TCPS_CLOSE_WAIT:
1692 		tp->t_state = TCPS_LAST_ACK;
1693 		break;
1694 	}
1695 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1696 		soisdisconnected(tp->t_inpcb->inp_socket);
1697 		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
1698 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1699 			tcp_callout_reset(tp, tp->tt_2msl, tp->t_maxidle,
1700 			    tcp_timer_2msl);
1701 		}
1702 	}
1703 	return (tp);
1704 }
1705