xref: /dflybsd-src/sys/netinet/tcp_usrreq.c (revision 45be1c61ffc4ced70f698da62c2f88fe6792f339)
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 static void
378 tcp_sosetport(struct lwkt_msg *msg, lwkt_port_t port)
379 {
380 	sosetport(((struct netmsg_base *)msg)->nm_so, port);
381 }
382 
383 /*
384  * Prepare to accept connections.
385  */
386 static void
387 tcp_usr_listen(netmsg_t msg)
388 {
389 	struct socket *so = msg->listen.base.nm_so;
390 	struct thread *td = msg->listen.nm_td;
391 	int error = 0;
392 	struct inpcb *inp;
393 	struct tcpcb *tp;
394 	struct netmsg_inswildcard nm;
395 	lwkt_port_t port0 = netisr_cpuport(0);
396 
397 	COMMON_START(so, inp, 0);
398 
399 	if (&curthread->td_msgport != port0) {
400 		lwkt_msg_t lmsg = &msg->listen.base.lmsg;
401 
402 		KASSERT((msg->listen.nm_flags & PRUL_RELINK) == 0,
403 		    ("already asked to relink"));
404 
405 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpuid]);
406 		msg->listen.nm_flags |= PRUL_RELINK;
407 
408 		/* See the related comment in tcp_connect() */
409 		lwkt_setmsg_receipt(lmsg, tcp_sosetport);
410 		lwkt_forwardmsg(port0, lmsg);
411 		/* msg invalid now */
412 		return;
413 	}
414 	KASSERT(so->so_port == port0, ("so_port is not netisr0"));
415 
416 	if (msg->listen.nm_flags & PRUL_RELINK) {
417 		msg->listen.nm_flags &= ~PRUL_RELINK;
418 		in_pcblink(so->so_pcb, &tcbinfo[mycpuid]);
419 	}
420 	KASSERT(inp->inp_pcbinfo == &tcbinfo[0], ("pcbinfo is not tcbinfo0"));
421 
422 	if (tp->t_flags & TF_LISTEN)
423 		goto out;
424 
425 	if (inp->inp_lport == 0) {
426 		error = in_pcbbind(inp, NULL, td);
427 		if (error)
428 			goto out;
429 	}
430 
431 	tp->t_state = TCPS_LISTEN;
432 	tp->t_flags |= TF_LISTEN;
433 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
434 
435 	if (ncpus > 1) {
436 		/*
437 		 * We have to set the flag because we can't have other cpus
438 		 * messing with our inp's flags.
439 		 */
440 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
441 			("already on connhash"));
442 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
443 			("already on wildcardhash"));
444 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
445 			("already on MP wildcardhash"));
446 		inp->inp_flags |= INP_WILDCARD_MP;
447 
448 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
449 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
450 		nm.nm_inp = inp;
451 		lwkt_domsg(netisr_cpuport(1), &nm.base.lmsg, 0);
452 	}
453 	in_pcbinswildcardhash(inp);
454 	COMMON_END(PRU_LISTEN);
455 }
456 
457 #ifdef INET6
458 
459 static void
460 tcp6_usr_listen(netmsg_t msg)
461 {
462 	struct socket *so = msg->listen.base.nm_so;
463 	struct thread *td = msg->listen.nm_td;
464 	int error = 0;
465 	struct inpcb *inp;
466 	struct tcpcb *tp;
467 	struct netmsg_inswildcard nm;
468 
469 	COMMON_START(so, inp, 0);
470 
471 	if (tp->t_flags & TF_LISTEN)
472 		goto out;
473 
474 	if (inp->inp_lport == 0) {
475 		if (!(inp->inp_flags & IN6P_IPV6_V6ONLY))
476 			inp->inp_vflag |= INP_IPV4;
477 		else
478 			inp->inp_vflag &= ~INP_IPV4;
479 		error = in6_pcbbind(inp, NULL, td);
480 		if (error)
481 			goto out;
482 	}
483 
484 	tp->t_state = TCPS_LISTEN;
485 	tp->t_flags |= TF_LISTEN;
486 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
487 
488 	if (ncpus > 1) {
489 		/*
490 		 * We have to set the flag because we can't have other cpus
491 		 * messing with our inp's flags.
492 		 */
493 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
494 			("already on connhash"));
495 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
496 			("already on wildcardhash"));
497 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
498 			("already on MP wildcardhash"));
499 		inp->inp_flags |= INP_WILDCARD_MP;
500 
501 		KKASSERT(so->so_port == netisr_cpuport(0));
502 		KKASSERT(&curthread->td_msgport == netisr_cpuport(0));
503 		KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
504 
505 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
506 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
507 		nm.nm_inp = inp;
508 		lwkt_domsg(netisr_cpuport(1), &nm.base.lmsg, 0);
509 	}
510 	in_pcbinswildcardhash(inp);
511 	COMMON_END(PRU_LISTEN);
512 }
513 #endif /* INET6 */
514 
515 /*
516  * Initiate connection to peer.
517  * Create a template for use in transmissions on this connection.
518  * Enter SYN_SENT state, and mark socket as connecting.
519  * Start keep-alive timer, and seed output sequence space.
520  * Send initial segment on connection.
521  */
522 static void
523 tcp_usr_connect(netmsg_t msg)
524 {
525 	struct socket *so = msg->connect.base.nm_so;
526 	struct sockaddr *nam = msg->connect.nm_nam;
527 	struct thread *td = msg->connect.nm_td;
528 	int error = 0;
529 	struct inpcb *inp;
530 	struct tcpcb *tp;
531 	struct sockaddr_in *sinp;
532 
533 	COMMON_START(so, inp, 0);
534 
535 	/*
536 	 * Must disallow TCP ``connections'' to multicast addresses.
537 	 */
538 	sinp = (struct sockaddr_in *)nam;
539 	if (sinp->sin_family == AF_INET
540 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
541 		error = EAFNOSUPPORT;
542 		goto out;
543 	}
544 
545 	if (!prison_remote_ip(td, (struct sockaddr*)sinp)) {
546 		error = EAFNOSUPPORT; /* IPv6 only jail */
547 		goto out;
548 	}
549 
550 	tcp_connect(msg);
551 	/* msg is invalid now */
552 	return;
553 out:
554 	if (msg->connect.nm_m) {
555 		m_freem(msg->connect.nm_m);
556 		msg->connect.nm_m = NULL;
557 	}
558 	if (msg->connect.nm_flags & PRUC_HELDTD)
559 		lwkt_rele(td);
560 	if (error && (msg->connect.nm_flags & PRUC_ASYNC)) {
561 		so->so_error = error;
562 		soisdisconnected(so);
563 	}
564 	lwkt_replymsg(&msg->lmsg, error);
565 }
566 
567 #ifdef INET6
568 
569 static void
570 tcp6_usr_connect(netmsg_t msg)
571 {
572 	struct socket *so = msg->connect.base.nm_so;
573 	struct sockaddr *nam = msg->connect.nm_nam;
574 	struct thread *td = msg->connect.nm_td;
575 	int error = 0;
576 	struct inpcb *inp;
577 	struct tcpcb *tp;
578 	struct sockaddr_in6 *sin6p;
579 
580 	COMMON_START(so, inp, 0);
581 
582 	/*
583 	 * Must disallow TCP ``connections'' to multicast addresses.
584 	 */
585 	sin6p = (struct sockaddr_in6 *)nam;
586 	if (sin6p->sin6_family == AF_INET6
587 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
588 		error = EAFNOSUPPORT;
589 		goto out;
590 	}
591 
592 	if (!prison_remote_ip(td, nam)) {
593 		error = EAFNOSUPPORT; /* IPv4 only jail */
594 		goto out;
595 	}
596 
597 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
598 		struct sockaddr_in *sinp;
599 
600 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
601 			error = EINVAL;
602 			goto out;
603 		}
604 		sinp = kmalloc(sizeof(*sinp), M_LWKTMSG, M_INTWAIT);
605 		in6_sin6_2_sin(sinp, sin6p);
606 		inp->inp_vflag |= INP_IPV4;
607 		inp->inp_vflag &= ~INP_IPV6;
608 		msg->connect.nm_nam = (struct sockaddr *)sinp;
609 		msg->connect.nm_flags |= PRUC_NAMALLOC;
610 		tcp_connect(msg);
611 		/* msg is invalid now */
612 		return;
613 	}
614 	inp->inp_vflag &= ~INP_IPV4;
615 	inp->inp_vflag |= INP_IPV6;
616 	inp->inp_inc.inc_isipv6 = 1;
617 
618 	msg->connect.nm_flags |= PRUC_FALLBACK;
619 	tcp6_connect(msg);
620 	/* msg is invalid now */
621 	return;
622 out:
623 	if (msg->connect.nm_m) {
624 		m_freem(msg->connect.nm_m);
625 		msg->connect.nm_m = NULL;
626 	}
627 	lwkt_replymsg(&msg->lmsg, error);
628 }
629 
630 #endif /* INET6 */
631 
632 /*
633  * Initiate disconnect from peer.
634  * If connection never passed embryonic stage, just drop;
635  * else if don't need to let data drain, then can just drop anyways,
636  * else have to begin TCP shutdown process: mark socket disconnecting,
637  * drain unread data, state switch to reflect user close, and
638  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
639  * when peer sends FIN and acks ours.
640  *
641  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
642  */
643 static void
644 tcp_usr_disconnect(netmsg_t msg)
645 {
646 	struct socket *so = msg->disconnect.base.nm_so;
647 	int error = 0;
648 	struct inpcb *inp;
649 	struct tcpcb *tp;
650 
651 	COMMON_START(so, inp, 1);
652 	tp = tcp_disconnect(tp);
653 	COMMON_END(PRU_DISCONNECT);
654 }
655 
656 /*
657  * Accept a connection.  Essentially all the work is
658  * done at higher levels; just return the address
659  * of the peer, storing through addr.
660  */
661 static void
662 tcp_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 	if (so->so_state & SS_ISDISCONNECTED) {
673 		error = ECONNABORTED;
674 		goto out;
675 	}
676 	if (inp == 0) {
677 		error = EINVAL;
678 		goto out;
679 	}
680 
681 	tp = intotcpcb(inp);
682 	TCPDEBUG1();
683 	in_setpeeraddr(so, nam);
684 	COMMON_END(PRU_ACCEPT);
685 }
686 
687 #ifdef INET6
688 static void
689 tcp6_usr_accept(netmsg_t msg)
690 {
691 	struct socket *so = msg->accept.base.nm_so;
692 	struct sockaddr **nam = msg->accept.nm_nam;
693 	int error = 0;
694 	struct inpcb *inp;
695 	struct tcpcb *tp = NULL;
696 	TCPDEBUG0;
697 
698 	inp = so->so_pcb;
699 
700 	if (so->so_state & SS_ISDISCONNECTED) {
701 		error = ECONNABORTED;
702 		goto out;
703 	}
704 	if (inp == 0) {
705 		error = EINVAL;
706 		goto out;
707 	}
708 	tp = intotcpcb(inp);
709 	TCPDEBUG1();
710 	in6_mapped_peeraddr(so, nam);
711 	COMMON_END(PRU_ACCEPT);
712 }
713 #endif /* INET6 */
714 /*
715  * Mark the connection as being incapable of further output.
716  */
717 static void
718 tcp_usr_shutdown(netmsg_t msg)
719 {
720 	struct socket *so = msg->shutdown.base.nm_so;
721 	int error = 0;
722 	struct inpcb *inp;
723 	struct tcpcb *tp;
724 
725 	COMMON_START(so, inp, 0);
726 	socantsendmore(so);
727 	tp = tcp_usrclosed(tp);
728 	if (tp)
729 		error = tcp_output(tp);
730 	COMMON_END(PRU_SHUTDOWN);
731 }
732 
733 /*
734  * After a receive, possibly send window update to peer.
735  */
736 static void
737 tcp_usr_rcvd(netmsg_t msg)
738 {
739 	struct socket *so = msg->rcvd.base.nm_so;
740 	int error = 0, noreply = 0;
741 	struct inpcb *inp;
742 	struct tcpcb *tp;
743 
744 	COMMON_START(so, inp, 0);
745 
746 	if (msg->rcvd.nm_pru_flags & PRUR_ASYNC) {
747 		noreply = 1;
748 		so_async_rcvd_reply(so);
749 	}
750 	tcp_output(tp);
751 
752 	COMMON_END1(PRU_RCVD, noreply);
753 }
754 
755 /*
756  * Do a send by putting data in output queue and updating urgent
757  * marker if URG set.  Possibly send more data.  Unlike the other
758  * pru_*() routines, the mbuf chains are our responsibility.  We
759  * must either enqueue them or free them.  The other pru_* routines
760  * generally are caller-frees.
761  */
762 static void
763 tcp_usr_send(netmsg_t msg)
764 {
765 	struct socket *so = msg->send.base.nm_so;
766 	int flags = msg->send.nm_flags;
767 	struct mbuf *m = msg->send.nm_m;
768 	int error = 0;
769 	struct inpcb *inp;
770 	struct tcpcb *tp;
771 	TCPDEBUG0;
772 
773 	KKASSERT(msg->send.nm_control == NULL);
774 	KKASSERT(msg->send.nm_addr == NULL);
775 	KKASSERT((flags & PRUS_FREEADDR) == 0);
776 
777 	inp = so->so_pcb;
778 
779 	if (inp == NULL) {
780 		/*
781 		 * OOPS! we lost a race, the TCP session got reset after
782 		 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a
783 		 * network interrupt in the non-critical section of sosend().
784 		 */
785 		m_freem(m);
786 		error = ECONNRESET;	/* XXX EPIPE? */
787 		tp = NULL;
788 		TCPDEBUG1();
789 		goto out;
790 	}
791 	tp = intotcpcb(inp);
792 	TCPDEBUG1();
793 
794 #ifdef foo
795 	/*
796 	 * This is no longer necessary, since:
797 	 * - sosendtcp() has already checked it for us
798 	 * - It does not work with asynchronized send
799 	 */
800 
801 	/*
802 	 * Don't let too much OOB data build up
803 	 */
804 	if (flags & PRUS_OOB) {
805 		if (ssb_space(&so->so_snd) < -512) {
806 			m_freem(m);
807 			error = ENOBUFS;
808 			goto out;
809 		}
810 	}
811 #endif
812 
813 	/*
814 	 * Pump the data into the socket.
815 	 */
816 	if (m) {
817 		ssb_appendstream(&so->so_snd, m);
818 		sowwakeup(so);
819 	}
820 	if (flags & PRUS_OOB) {
821 		/*
822 		 * According to RFC961 (Assigned Protocols),
823 		 * the urgent pointer points to the last octet
824 		 * of urgent data.  We continue, however,
825 		 * to consider it to indicate the first octet
826 		 * of data past the urgent section.
827 		 * Otherwise, snd_up should be one lower.
828 		 */
829 		tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
830 		tp->t_flags |= TF_FORCE;
831 		error = tcp_output(tp);
832 		tp->t_flags &= ~TF_FORCE;
833 	} else {
834 		if (flags & PRUS_EOF) {
835 			/*
836 			 * Close the send side of the connection after
837 			 * the data is sent.
838 			 */
839 			socantsendmore(so);
840 			tp = tcp_usrclosed(tp);
841 		}
842 		if (tp != NULL && !tcp_output_pending(tp)) {
843 			if (flags & PRUS_MORETOCOME)
844 				tp->t_flags |= TF_MORETOCOME;
845 			error = tcp_output_fair(tp);
846 			if (flags & PRUS_MORETOCOME)
847 				tp->t_flags &= ~TF_MORETOCOME;
848 		}
849 	}
850 	COMMON_END1((flags & PRUS_OOB) ? PRU_SENDOOB :
851 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND),
852 		   (flags & PRUS_NOREPLY));
853 }
854 
855 /*
856  * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
857  *	 will sofree() it when we return.
858  */
859 static void
860 tcp_usr_abort(netmsg_t msg)
861 {
862 	struct socket *so = msg->abort.base.nm_so;
863 	int error = 0;
864 	struct inpcb *inp;
865 	struct tcpcb *tp;
866 
867 	COMMON_START(so, inp, 1);
868 	tp = tcp_drop(tp, ECONNABORTED);
869 	COMMON_END(PRU_ABORT);
870 }
871 
872 /*
873  * Receive out-of-band data.
874  */
875 static void
876 tcp_usr_rcvoob(netmsg_t msg)
877 {
878 	struct socket *so = msg->rcvoob.base.nm_so;
879 	struct mbuf *m = msg->rcvoob.nm_m;
880 	int flags = msg->rcvoob.nm_flags;
881 	int error = 0;
882 	struct inpcb *inp;
883 	struct tcpcb *tp;
884 
885 	COMMON_START(so, inp, 0);
886 	if ((so->so_oobmark == 0 &&
887 	     (so->so_state & SS_RCVATMARK) == 0) ||
888 	    so->so_options & SO_OOBINLINE ||
889 	    tp->t_oobflags & TCPOOB_HADDATA) {
890 		error = EINVAL;
891 		goto out;
892 	}
893 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
894 		error = EWOULDBLOCK;
895 		goto out;
896 	}
897 	m->m_len = 1;
898 	*mtod(m, caddr_t) = tp->t_iobc;
899 	if ((flags & MSG_PEEK) == 0)
900 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
901 	COMMON_END(PRU_RCVOOB);
902 }
903 
904 static void
905 tcp_usr_savefaddr(struct socket *so, const struct sockaddr *faddr)
906 {
907 	in_savefaddr(so, faddr);
908 }
909 
910 #ifdef INET6
911 static void
912 tcp6_usr_savefaddr(struct socket *so, const struct sockaddr *faddr)
913 {
914 	in6_mapped_savefaddr(so, faddr);
915 }
916 #endif
917 
918 static int
919 tcp_usr_preconnect(struct socket *so, const struct sockaddr *nam,
920     struct thread *td __unused)
921 {
922 	const struct sockaddr_in *sinp;
923 
924 	sinp = (const struct sockaddr_in *)nam;
925 	if (sinp->sin_family == AF_INET &&
926 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
927 		return EAFNOSUPPORT;
928 
929 	soisconnecting(so);
930 	return 0;
931 }
932 
933 /* xxx - should be const */
934 struct pr_usrreqs tcp_usrreqs = {
935 	.pru_abort = tcp_usr_abort,
936 	.pru_accept = tcp_usr_accept,
937 	.pru_attach = tcp_usr_attach,
938 	.pru_bind = tcp_usr_bind,
939 	.pru_connect = tcp_usr_connect,
940 	.pru_connect2 = pr_generic_notsupp,
941 	.pru_control = in_control_dispatch,
942 	.pru_detach = tcp_usr_detach,
943 	.pru_disconnect = tcp_usr_disconnect,
944 	.pru_listen = tcp_usr_listen,
945 	.pru_peeraddr = in_setpeeraddr_dispatch,
946 	.pru_rcvd = tcp_usr_rcvd,
947 	.pru_rcvoob = tcp_usr_rcvoob,
948 	.pru_send = tcp_usr_send,
949 	.pru_sense = pru_sense_null,
950 	.pru_shutdown = tcp_usr_shutdown,
951 	.pru_sockaddr = in_setsockaddr_dispatch,
952 	.pru_sosend = sosendtcp,
953 	.pru_soreceive = sorecvtcp,
954 	.pru_savefaddr = tcp_usr_savefaddr,
955 	.pru_preconnect = tcp_usr_preconnect
956 };
957 
958 #ifdef INET6
959 struct pr_usrreqs tcp6_usrreqs = {
960 	.pru_abort = tcp_usr_abort,
961 	.pru_accept = tcp6_usr_accept,
962 	.pru_attach = tcp_usr_attach,
963 	.pru_bind = tcp6_usr_bind,
964 	.pru_connect = tcp6_usr_connect,
965 	.pru_connect2 = pr_generic_notsupp,
966 	.pru_control = in6_control_dispatch,
967 	.pru_detach = tcp_usr_detach,
968 	.pru_disconnect = tcp_usr_disconnect,
969 	.pru_listen = tcp6_usr_listen,
970 	.pru_peeraddr = in6_mapped_peeraddr_dispatch,
971 	.pru_rcvd = tcp_usr_rcvd,
972 	.pru_rcvoob = tcp_usr_rcvoob,
973 	.pru_send = tcp_usr_send,
974 	.pru_sense = pru_sense_null,
975 	.pru_shutdown = tcp_usr_shutdown,
976 	.pru_sockaddr = in6_mapped_sockaddr_dispatch,
977 	.pru_sosend = sosendtcp,
978 	.pru_soreceive = sorecvtcp,
979 	.pru_savefaddr = tcp6_usr_savefaddr
980 };
981 #endif /* INET6 */
982 
983 static int
984 tcp_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf *m,
985 		  struct sockaddr_in *sin, struct sockaddr_in *if_sin)
986 {
987 	struct inpcb *inp = tp->t_inpcb, *oinp;
988 	struct socket *so = inp->inp_socket;
989 	struct route *ro = &inp->inp_route;
990 
991 	KASSERT(inp->inp_pcbinfo == &tcbinfo[mycpu->gd_cpuid],
992 	    ("pcbinfo mismatch"));
993 
994 	oinp = in_pcblookup_hash(inp->inp_pcbinfo,
995 				 sin->sin_addr, sin->sin_port,
996 				 (inp->inp_laddr.s_addr != INADDR_ANY ?
997 				  inp->inp_laddr : if_sin->sin_addr),
998 				inp->inp_lport, 0, NULL);
999 	if (oinp != NULL) {
1000 		m_freem(m);
1001 		return (EADDRINUSE);
1002 	}
1003 	if (inp->inp_laddr.s_addr == INADDR_ANY)
1004 		inp->inp_laddr = if_sin->sin_addr;
1005 	inp->inp_faddr = sin->sin_addr;
1006 	inp->inp_fport = sin->sin_port;
1007 	in_pcbinsconnhash(inp);
1008 
1009 	/*
1010 	 * We are now on the inpcb's owner CPU, if the cached route was
1011 	 * freed because the rtentry's owner CPU is not the current CPU
1012 	 * (e.g. in tcp_connect()), then we try to reallocate it here with
1013 	 * the hope that a rtentry may be cloned from a RTF_PRCLONING
1014 	 * rtentry.
1015 	 */
1016 	if (!(inp->inp_socket->so_options & SO_DONTROUTE) && /*XXX*/
1017 	    ro->ro_rt == NULL) {
1018 		bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
1019 		ro->ro_dst.sa_family = AF_INET;
1020 		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
1021 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr =
1022 			sin->sin_addr;
1023 		rtalloc(ro);
1024 	}
1025 
1026 	/*
1027 	 * Now that no more errors can occur, change the protocol processing
1028 	 * port to the current thread (which is the correct thread).
1029 	 *
1030 	 * Create TCP timer message now; we are on the tcpcb's owner
1031 	 * CPU/thread.
1032 	 */
1033 	tcp_create_timermsg(tp, &curthread->td_msgport);
1034 
1035 	/*
1036 	 * Compute window scaling to request.  Use a larger scaling then
1037 	 * needed for the initial receive buffer in case the receive buffer
1038 	 * gets expanded.
1039 	 */
1040 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1041 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1042 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1043 	       (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat
1044 	) {
1045 		tp->request_r_scale++;
1046 	}
1047 
1048 	soisconnecting(so);
1049 	tcpstat.tcps_connattempt++;
1050 	tp->t_state = TCPS_SYN_SENT;
1051 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1052 	tp->iss = tcp_new_isn(tp);
1053 	tcp_sendseqinit(tp);
1054 	if (m) {
1055 		ssb_appendstream(&so->so_snd, m);
1056 		m = NULL;
1057 		if (flags & PRUS_OOB)
1058 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1059 	}
1060 
1061 	/*
1062 	 * Close the send side of the connection after
1063 	 * the data is sent if flagged.
1064 	 */
1065 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1066 		socantsendmore(so);
1067 		tp = tcp_usrclosed(tp);
1068 	}
1069 	return (tcp_output(tp));
1070 }
1071 
1072 /*
1073  * Common subroutine to open a TCP connection to remote host specified
1074  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1075  * port number if needed.  Call in_pcbladdr to do the routing and to choose
1076  * a local host address (interface).
1077  * Initialize connection parameters and enter SYN-SENT state.
1078  */
1079 static void
1080 tcp_connect(netmsg_t msg)
1081 {
1082 	struct socket *so = msg->connect.base.nm_so;
1083 	struct sockaddr *nam = msg->connect.nm_nam;
1084 	struct thread *td = msg->connect.nm_td;
1085 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
1086 	struct sockaddr_in *if_sin = NULL;
1087 	struct inpcb *inp;
1088 	struct tcpcb *tp;
1089 	int error;
1090 	lwkt_port_t port;
1091 
1092 	COMMON_START(so, inp, 0);
1093 
1094 	/*
1095 	 * Reconnect our pcb if we have to
1096 	 */
1097 	if (msg->connect.nm_flags & PRUC_RECONNECT) {
1098 		msg->connect.nm_flags &= ~PRUC_RECONNECT;
1099 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1100 	}
1101 
1102 	/*
1103 	 * Bind if we have to
1104 	 */
1105 	if (inp->inp_lport == 0) {
1106 		if (tcp_lport_extension) {
1107 			KKASSERT(inp->inp_laddr.s_addr == INADDR_ANY);
1108 
1109 			error = in_pcbladdr(inp, nam, &if_sin, td);
1110 			if (error)
1111 				goto out;
1112 			inp->inp_laddr.s_addr = if_sin->sin_addr.s_addr;
1113 
1114 			error = in_pcbbind_remote(inp, nam, td);
1115 			if (error)
1116 				goto out;
1117 
1118 			msg->connect.nm_flags |= PRUC_HASLADDR;
1119 		} else {
1120 			error = in_pcbbind(inp, NULL, td);
1121 			if (error)
1122 				goto out;
1123 		}
1124 	}
1125 
1126 	if ((msg->connect.nm_flags & PRUC_HASLADDR) == 0) {
1127 		/*
1128 		 * Calculate the correct protocol processing thread.  The
1129 		 * connect operation must run there.  Set the forwarding
1130 		 * port before we forward the message or it will get bounced
1131 		 * right back to us.
1132 		 */
1133 		error = in_pcbladdr(inp, nam, &if_sin, td);
1134 		if (error)
1135 			goto out;
1136 	}
1137 	KKASSERT(inp->inp_socket == so);
1138 
1139 	port = tcp_addrport(sin->sin_addr.s_addr, sin->sin_port,
1140 			    (inp->inp_laddr.s_addr != INADDR_ANY ?
1141 			     inp->inp_laddr.s_addr : if_sin->sin_addr.s_addr),
1142 			    inp->inp_lport);
1143 
1144 	if (port != &curthread->td_msgport) {
1145 		struct route *ro = &inp->inp_route;
1146 		lwkt_msg_t lmsg = &msg->connect.base.lmsg;
1147 
1148 		/*
1149 		 * in_pcbladdr() may have allocated a route entry for us
1150 		 * on the current CPU, but we need a route entry on the
1151 		 * inpcb's owner CPU, so free it here.
1152 		 */
1153 		if (ro->ro_rt != NULL)
1154 			RTFREE(ro->ro_rt);
1155 		bzero(ro, sizeof(*ro));
1156 
1157 		/*
1158 		 * We are moving the protocol processing port the socket
1159 		 * is on, we have to unlink here and re-link on the
1160 		 * target cpu.
1161 		 */
1162 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1163 		msg->connect.nm_flags |= PRUC_RECONNECT;
1164 		msg->connect.base.nm_dispatch = tcp_connect;
1165 
1166 		/*
1167 		 * Use message put done receipt to change this socket's
1168 		 * so_port, i.e. _after_ this message was put onto the
1169 		 * target netisr's msgport but _before_ the message could
1170 		 * be pulled from the target netisr's msgport, so that:
1171 		 * - The upper half (socket code) will not see the new
1172 		 *   msgport before this message reaches the new msgport
1173 		 *   and messages for this socket will be ordered.
1174 		 * - This message will see the new msgport, when its
1175 		 *   handler is called in the target netisr.
1176 		 *
1177 		 * NOTE:
1178 		 * We MUST use messege put done receipt to change this
1179 		 * socket's so_port:
1180 		 * If we changed the so_port in this netisr after the
1181 		 * lwkt_forwardmsg (so messages for this socket will be
1182 		 * ordered) and changed the so_port in the target netisr
1183 		 * at the very beginning of this message's handler, we
1184 		 * would suffer so_port overwritten race, given this
1185 		 * message might be forwarded again.
1186 		 *
1187 		 * NOTE:
1188 		 * This mechanism depends on that the netisr's msgport
1189 		 * is spin msgport (currently it is :).
1190 		 *
1191 		 * If the upper half saw the new msgport before this
1192 		 * message reached the target netisr's msgport, the
1193 		 * messages sent from the upper half could reach the new
1194 		 * msgport before this message, thus there would be
1195 		 * message reordering.  The worst case could be soclose()
1196 		 * saw the new msgport and the detach message could reach
1197 		 * the new msgport before this message, i.e. the inpcb
1198 		 * could have been destroyed when this message was still
1199 		 * pending on or on its way to the new msgport.  Other
1200 		 * weird cases could also happen, e.g. inpcb->inp_pcbinfo,
1201 		 * since we have unlinked this inpcb from the current
1202 		 * pcbinfo first.
1203 		 */
1204 		lwkt_setmsg_receipt(lmsg, tcp_sosetport);
1205 		lwkt_forwardmsg(port, lmsg);
1206 		/* msg invalid now */
1207 		return;
1208 	} else if (msg->connect.nm_flags & PRUC_HELDTD) {
1209 		/*
1210 		 * The original thread is no longer needed; release it.
1211 		 */
1212 		lwkt_rele(td);
1213 		msg->connect.nm_flags &= ~PRUC_HELDTD;
1214 	}
1215 	error = tcp_connect_oncpu(tp, msg->connect.nm_sndflags,
1216 				  msg->connect.nm_m, sin, if_sin);
1217 	msg->connect.nm_m = NULL;
1218 out:
1219 	if (msg->connect.nm_m) {
1220 		m_freem(msg->connect.nm_m);
1221 		msg->connect.nm_m = NULL;
1222 	}
1223 	if (msg->connect.nm_flags & PRUC_NAMALLOC) {
1224 		kfree(msg->connect.nm_nam, M_LWKTMSG);
1225 		msg->connect.nm_nam = NULL;
1226 	}
1227 	if (msg->connect.nm_flags & PRUC_HELDTD)
1228 		lwkt_rele(td);
1229 	if (error && (msg->connect.nm_flags & PRUC_ASYNC)) {
1230 		so->so_error = error;
1231 		soisdisconnected(so);
1232 	}
1233 	lwkt_replymsg(&msg->connect.base.lmsg, error);
1234 	/* msg invalid now */
1235 }
1236 
1237 #ifdef INET6
1238 
1239 static void
1240 tcp6_connect(netmsg_t msg)
1241 {
1242 	struct tcpcb *tp;
1243 	struct socket *so = msg->connect.base.nm_so;
1244 	struct sockaddr *nam = msg->connect.nm_nam;
1245 	struct thread *td = msg->connect.nm_td;
1246 	struct inpcb *inp;
1247 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1248 	struct in6_addr *addr6;
1249 	lwkt_port_t port;
1250 	int error;
1251 
1252 	COMMON_START(so, inp, 0);
1253 
1254 	/*
1255 	 * Reconnect our pcb if we have to
1256 	 */
1257 	if (msg->connect.nm_flags & PRUC_RECONNECT) {
1258 		msg->connect.nm_flags &= ~PRUC_RECONNECT;
1259 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1260 	}
1261 
1262 	/*
1263 	 * Bind if we have to
1264 	 */
1265 	if (inp->inp_lport == 0) {
1266 		error = in6_pcbbind(inp, NULL, td);
1267 		if (error)
1268 			goto out;
1269 	}
1270 
1271 	/*
1272 	 * Cannot simply call in_pcbconnect, because there might be an
1273 	 * earlier incarnation of this same connection still in
1274 	 * TIME_WAIT state, creating an ADDRINUSE error.
1275 	 */
1276 	error = in6_pcbladdr(inp, nam, &addr6, td);
1277 	if (error)
1278 		goto out;
1279 
1280 	port = tcp6_addrport();	/* XXX hack for now, always cpu0 */
1281 
1282 	if (port != &curthread->td_msgport) {
1283 		struct route *ro = &inp->inp_route;
1284 		lwkt_msg_t lmsg = &msg->connect.base.lmsg;
1285 
1286 		/*
1287 		 * in_pcbladdr() may have allocated a route entry for us
1288 		 * on the current CPU, but we need a route entry on the
1289 		 * inpcb's owner CPU, so free it here.
1290 		 */
1291 		if (ro->ro_rt != NULL)
1292 			RTFREE(ro->ro_rt);
1293 		bzero(ro, sizeof(*ro));
1294 
1295 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1296 		msg->connect.nm_flags |= PRUC_RECONNECT;
1297 		msg->connect.base.nm_dispatch = tcp6_connect;
1298 
1299 		/* See the related comment in tcp_connect() */
1300 		lwkt_setmsg_receipt(lmsg, tcp_sosetport);
1301 		lwkt_forwardmsg(port, lmsg);
1302 		/* msg invalid now */
1303 		return;
1304 	}
1305 	error = tcp6_connect_oncpu(tp, msg->connect.nm_sndflags,
1306 				   &msg->connect.nm_m, sin6, addr6);
1307 	/* nm_m may still be intact */
1308 out:
1309 	if (error && (msg->connect.nm_flags & PRUC_FALLBACK)) {
1310 		tcp_connect(msg);
1311 		/* msg invalid now */
1312 	} else {
1313 		if (msg->connect.nm_m) {
1314 			m_freem(msg->connect.nm_m);
1315 			msg->connect.nm_m = NULL;
1316 		}
1317 		if (msg->connect.nm_flags & PRUC_NAMALLOC) {
1318 			kfree(msg->connect.nm_nam, M_LWKTMSG);
1319 			msg->connect.nm_nam = NULL;
1320 		}
1321 		lwkt_replymsg(&msg->connect.base.lmsg, error);
1322 		/* msg invalid now */
1323 	}
1324 }
1325 
1326 static int
1327 tcp6_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf **mp,
1328 		   struct sockaddr_in6 *sin6, struct in6_addr *addr6)
1329 {
1330 	struct mbuf *m = *mp;
1331 	struct inpcb *inp = tp->t_inpcb;
1332 	struct socket *so = inp->inp_socket;
1333 	struct inpcb *oinp;
1334 
1335 	/*
1336 	 * Cannot simply call in_pcbconnect, because there might be an
1337 	 * earlier incarnation of this same connection still in
1338 	 * TIME_WAIT state, creating an ADDRINUSE error.
1339 	 */
1340 	oinp = in6_pcblookup_hash(inp->inp_pcbinfo,
1341 				  &sin6->sin6_addr, sin6->sin6_port,
1342 				  (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ?
1343 				      addr6 : &inp->in6p_laddr),
1344 				  inp->inp_lport,  0, NULL);
1345 	if (oinp)
1346 		return (EADDRINUSE);
1347 
1348 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1349 		inp->in6p_laddr = *addr6;
1350 	inp->in6p_faddr = sin6->sin6_addr;
1351 	inp->inp_fport = sin6->sin6_port;
1352 	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != 0)
1353 		inp->in6p_flowinfo = sin6->sin6_flowinfo;
1354 	in_pcbinsconnhash(inp);
1355 
1356 	/*
1357 	 * Now that no more errors can occur, change the protocol processing
1358 	 * port to the current thread (which is the correct thread).
1359 	 *
1360 	 * Create TCP timer message now; we are on the tcpcb's owner
1361 	 * CPU/thread.
1362 	 */
1363 	tcp_create_timermsg(tp, &curthread->td_msgport);
1364 
1365 	/* Compute window scaling to request.  */
1366 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1367 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1368 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1369 	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat) {
1370 		tp->request_r_scale++;
1371 	}
1372 
1373 	soisconnecting(so);
1374 	tcpstat.tcps_connattempt++;
1375 	tp->t_state = TCPS_SYN_SENT;
1376 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1377 	tp->iss = tcp_new_isn(tp);
1378 	tcp_sendseqinit(tp);
1379 	if (m) {
1380 		ssb_appendstream(&so->so_snd, m);
1381 		*mp = NULL;
1382 		if (flags & PRUS_OOB)
1383 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1384 	}
1385 
1386 	/*
1387 	 * Close the send side of the connection after
1388 	 * the data is sent if flagged.
1389 	 */
1390 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1391 		socantsendmore(so);
1392 		tp = tcp_usrclosed(tp);
1393 	}
1394 	return (tcp_output(tp));
1395 }
1396 
1397 #endif /* INET6 */
1398 
1399 /*
1400  * The new sockopt interface makes it possible for us to block in the
1401  * copyin/out step (if we take a page fault).  Taking a page fault while
1402  * in a critical section is probably a Bad Thing.  (Since sockets and pcbs
1403  * both now use TSM, there probably isn't any need for this function to
1404  * run in a critical section any more.  This needs more examination.)
1405  */
1406 void
1407 tcp_ctloutput(netmsg_t msg)
1408 {
1409 	struct socket *so = msg->base.nm_so;
1410 	struct sockopt *sopt = msg->ctloutput.nm_sopt;
1411 	int	error, opt, optval, opthz;
1412 	struct	inpcb *inp;
1413 	struct	tcpcb *tp;
1414 
1415 	error = 0;
1416 	inp = so->so_pcb;
1417 	if (inp == NULL) {
1418 		error = ECONNRESET;
1419 		goto done;
1420 	}
1421 
1422 	if (sopt->sopt_level != IPPROTO_TCP) {
1423 		switch (sopt->sopt_name) {
1424 		case IP_MULTICAST_IF:
1425 		case IP_MULTICAST_VIF:
1426 		case IP_MULTICAST_TTL:
1427 		case IP_MULTICAST_LOOP:
1428 		case IP_ADD_MEMBERSHIP:
1429 		case IP_DROP_MEMBERSHIP:
1430 			/*
1431 			 * Multicast does not make sense on TCP sockets.
1432 			 */
1433 			error = EOPNOTSUPP;
1434 			goto done;
1435 		}
1436 #ifdef INET6
1437 		if (INP_CHECK_SOCKAF(so, AF_INET6))
1438 			ip6_ctloutput_dispatch(msg);
1439 		else
1440 #endif /* INET6 */
1441 		ip_ctloutput(msg);
1442 		/* msg invalid now */
1443 		return;
1444 	}
1445 	tp = intotcpcb(inp);
1446 
1447 	switch (sopt->sopt_dir) {
1448 	case SOPT_SET:
1449 		error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1450 				      sizeof optval);
1451 		if (error)
1452 			break;
1453 		switch (sopt->sopt_name) {
1454 		case TCP_FASTKEEP:
1455 			if (optval > 0)
1456 				tp->t_keepidle = tp->t_keepintvl;
1457 			else
1458 				tp->t_keepidle = tcp_keepidle;
1459 			tcp_timer_keep_activity(tp, 0);
1460 			break;
1461 #ifdef TCP_SIGNATURE
1462 		case TCP_SIGNATURE_ENABLE:
1463 			if (tp->t_state == TCPS_CLOSED) {
1464 				/*
1465 				 * This is the only safe state that this
1466 				 * option could be changed.  Some segments
1467 				 * could already have been sent in other
1468 				 * states.
1469 				 */
1470 				if (optval > 0)
1471 					tp->t_flags |= TF_SIGNATURE;
1472 				else
1473 					tp->t_flags &= ~TF_SIGNATURE;
1474 			} else {
1475 				error = EOPNOTSUPP;
1476 			}
1477 			break;
1478 #endif /* TCP_SIGNATURE */
1479 		case TCP_NODELAY:
1480 		case TCP_NOOPT:
1481 			switch (sopt->sopt_name) {
1482 			case TCP_NODELAY:
1483 				opt = TF_NODELAY;
1484 				break;
1485 			case TCP_NOOPT:
1486 				opt = TF_NOOPT;
1487 				break;
1488 			default:
1489 				opt = 0; /* dead code to fool gcc */
1490 				break;
1491 			}
1492 
1493 			if (optval)
1494 				tp->t_flags |= opt;
1495 			else
1496 				tp->t_flags &= ~opt;
1497 			break;
1498 
1499 		case TCP_NOPUSH:
1500 			if (tcp_disable_nopush)
1501 				break;
1502 			if (optval)
1503 				tp->t_flags |= TF_NOPUSH;
1504 			else {
1505 				tp->t_flags &= ~TF_NOPUSH;
1506 				error = tcp_output(tp);
1507 			}
1508 			break;
1509 
1510 		case TCP_MAXSEG:
1511 			/*
1512 			 * Must be between 0 and maxseg.  If the requested
1513 			 * maxseg is too small to satisfy the desired minmss,
1514 			 * pump it up (silently so sysctl modifications of
1515 			 * minmss do not create unexpected program failures).
1516 			 * Handle degenerate cases.
1517 			 */
1518 			if (optval > 0 && optval <= tp->t_maxseg) {
1519 				if (optval + 40 < tcp_minmss) {
1520 					optval = tcp_minmss - 40;
1521 					if (optval < 0)
1522 						optval = 1;
1523 				}
1524 				tp->t_maxseg = optval;
1525 			} else {
1526 				error = EINVAL;
1527 			}
1528 			break;
1529 
1530 		case TCP_KEEPINIT:
1531 			opthz = ((int64_t)optval * hz) / 1000;
1532 			if (opthz >= 1)
1533 				tp->t_keepinit = opthz;
1534 			else
1535 				error = EINVAL;
1536 			break;
1537 
1538 		case TCP_KEEPIDLE:
1539 			opthz = ((int64_t)optval * hz) / 1000;
1540 			if (opthz >= 1) {
1541 				tp->t_keepidle = opthz;
1542 				tcp_timer_keep_activity(tp, 0);
1543 			} else {
1544 				error = EINVAL;
1545 			}
1546 			break;
1547 
1548 		case TCP_KEEPINTVL:
1549 			opthz = ((int64_t)optval * hz) / 1000;
1550 			if (opthz >= 1) {
1551 				tp->t_keepintvl = opthz;
1552 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1553 			} else {
1554 				error = EINVAL;
1555 			}
1556 			break;
1557 
1558 		case TCP_KEEPCNT:
1559 			if (optval > 0) {
1560 				tp->t_keepcnt = optval;
1561 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1562 			} else {
1563 				error = EINVAL;
1564 			}
1565 			break;
1566 
1567 		default:
1568 			error = ENOPROTOOPT;
1569 			break;
1570 		}
1571 		break;
1572 
1573 	case SOPT_GET:
1574 		switch (sopt->sopt_name) {
1575 #ifdef TCP_SIGNATURE
1576 		case TCP_SIGNATURE_ENABLE:
1577 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1578 			break;
1579 #endif /* TCP_SIGNATURE */
1580 		case TCP_NODELAY:
1581 			optval = tp->t_flags & TF_NODELAY;
1582 			break;
1583 		case TCP_MAXSEG:
1584 			optval = tp->t_maxseg;
1585 			break;
1586 		case TCP_NOOPT:
1587 			optval = tp->t_flags & TF_NOOPT;
1588 			break;
1589 		case TCP_NOPUSH:
1590 			optval = tp->t_flags & TF_NOPUSH;
1591 			break;
1592 		case TCP_KEEPINIT:
1593 			optval = ((int64_t)tp->t_keepinit * 1000) / hz;
1594 			break;
1595 		case TCP_KEEPIDLE:
1596 			optval = ((int64_t)tp->t_keepidle * 1000) / hz;
1597 			break;
1598 		case TCP_KEEPINTVL:
1599 			optval = ((int64_t)tp->t_keepintvl * 1000) / hz;
1600 			break;
1601 		case TCP_KEEPCNT:
1602 			optval = tp->t_keepcnt;
1603 			break;
1604 		default:
1605 			error = ENOPROTOOPT;
1606 			break;
1607 		}
1608 		if (error == 0)
1609 			soopt_from_kbuf(sopt, &optval, sizeof optval);
1610 		break;
1611 	}
1612 done:
1613 	lwkt_replymsg(&msg->lmsg, error);
1614 }
1615 
1616 /*
1617  * tcp_sendspace and tcp_recvspace are the default send and receive window
1618  * sizes, respectively.  These are obsolescent (this information should
1619  * be set by the route).
1620  *
1621  * Use a default that does not require tcp window scaling to be turned
1622  * on.  Individual programs or the administrator can increase the default.
1623  */
1624 u_long	tcp_sendspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1625 SYSCTL_INT(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1626     &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1627 u_long	tcp_recvspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1628 SYSCTL_INT(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1629     &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1630 
1631 /*
1632  * Attach TCP protocol to socket, allocating internet protocol control
1633  * block, tcp control block, buffer space, and entering CLOSED state.
1634  */
1635 static int
1636 tcp_attach(struct socket *so, struct pru_attach_info *ai)
1637 {
1638 	struct tcpcb *tp;
1639 	struct inpcb *inp;
1640 	int error;
1641 	int cpu;
1642 #ifdef INET6
1643 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
1644 #endif
1645 
1646 	if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
1647 		lwkt_gettoken(&so->so_rcv.ssb_token);
1648 		error = soreserve(so, tcp_sendspace, tcp_recvspace,
1649 				  ai->sb_rlimit);
1650 		lwkt_reltoken(&so->so_rcv.ssb_token);
1651 		if (error)
1652 			return (error);
1653 	}
1654 	atomic_set_int(&so->so_rcv.ssb_flags, SSB_AUTOSIZE | SSB_PREALLOC);
1655 	atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOSIZE | SSB_PREALLOC);
1656 	cpu = mycpu->gd_cpuid;
1657 
1658 	/*
1659 	 * Set the default port for protocol processing. This will likely
1660 	 * change when we connect.
1661 	 */
1662 	error = in_pcballoc(so, &tcbinfo[cpu]);
1663 	if (error)
1664 		return (error);
1665 	inp = so->so_pcb;
1666 #ifdef INET6
1667 	if (isipv6) {
1668 		inp->inp_vflag |= INP_IPV6;
1669 		inp->in6p_hops = -1;	/* use kernel default */
1670 	}
1671 	else
1672 #endif
1673 	inp->inp_vflag |= INP_IPV4;
1674 	tp = tcp_newtcpcb(inp);
1675 	if (tp == NULL) {
1676 		/*
1677 		 * Make sure the socket is destroyed by the pcbdetach.
1678 		 */
1679 		soreference(so);
1680 #ifdef INET6
1681 		if (isipv6)
1682 			in6_pcbdetach(inp);
1683 		else
1684 #endif
1685 		in_pcbdetach(inp);
1686 		sofree(so);	/* from ref above */
1687 		return (ENOBUFS);
1688 	}
1689 	tp->t_state = TCPS_CLOSED;
1690 	/* Keep a reference for asynchronized pru_rcvd */
1691 	soreference(so);
1692 	return (0);
1693 }
1694 
1695 /*
1696  * Initiate (or continue) disconnect.
1697  * If embryonic state, just send reset (once).
1698  * If in ``let data drain'' option and linger null, just drop.
1699  * Otherwise (hard), mark socket disconnecting and drop
1700  * current input data; switch states based on user close, and
1701  * send segment to peer (with FIN).
1702  */
1703 static struct tcpcb *
1704 tcp_disconnect(struct tcpcb *tp)
1705 {
1706 	struct socket *so = tp->t_inpcb->inp_socket;
1707 
1708 	if (tp->t_state < TCPS_ESTABLISHED) {
1709 		tp = tcp_close(tp);
1710 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1711 		tp = tcp_drop(tp, 0);
1712 	} else {
1713 		lwkt_gettoken(&so->so_rcv.ssb_token);
1714 		soisdisconnecting(so);
1715 		sbflush(&so->so_rcv.sb);
1716 		tp = tcp_usrclosed(tp);
1717 		if (tp)
1718 			tcp_output(tp);
1719 		lwkt_reltoken(&so->so_rcv.ssb_token);
1720 	}
1721 	return (tp);
1722 }
1723 
1724 /*
1725  * User issued close, and wish to trail through shutdown states:
1726  * if never received SYN, just forget it.  If got a SYN from peer,
1727  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1728  * If already got a FIN from peer, then almost done; go to LAST_ACK
1729  * state.  In all other cases, have already sent FIN to peer (e.g.
1730  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1731  * for peer to send FIN or not respond to keep-alives, etc.
1732  * We can let the user exit from the close as soon as the FIN is acked.
1733  */
1734 static struct tcpcb *
1735 tcp_usrclosed(struct tcpcb *tp)
1736 {
1737 
1738 	switch (tp->t_state) {
1739 
1740 	case TCPS_CLOSED:
1741 	case TCPS_LISTEN:
1742 		tp->t_state = TCPS_CLOSED;
1743 		tp = tcp_close(tp);
1744 		break;
1745 
1746 	case TCPS_SYN_SENT:
1747 	case TCPS_SYN_RECEIVED:
1748 		tp->t_flags |= TF_NEEDFIN;
1749 		break;
1750 
1751 	case TCPS_ESTABLISHED:
1752 		tp->t_state = TCPS_FIN_WAIT_1;
1753 		break;
1754 
1755 	case TCPS_CLOSE_WAIT:
1756 		tp->t_state = TCPS_LAST_ACK;
1757 		break;
1758 	}
1759 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1760 		soisdisconnected(tp->t_inpcb->inp_socket);
1761 		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
1762 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1763 			tcp_callout_reset(tp, tp->tt_2msl, tp->t_maxidle,
1764 			    tcp_timer_2msl);
1765 		}
1766 	}
1767 	return (tp);
1768 }
1769