xref: /dragonfly/sys/netinet/tcp_usrreq.c (revision aafe6ccc)
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  * Allocate socket buffer space.
176  */
177 static int
178 tcp_usr_preattach(struct socket *so, int proto __unused,
179     struct pru_attach_info *ai)
180 {
181 	int error;
182 
183 	if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
184 		error = soreserve(so, tcp_sendspace, tcp_recvspace,
185 				  ai->sb_rlimit);
186 		if (error)
187 			return (error);
188 	}
189 	atomic_set_int(&so->so_rcv.ssb_flags, SSB_AUTOSIZE | SSB_PREALLOC);
190 	atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOSIZE | SSB_PREALLOC);
191 
192 	return 0;
193 }
194 
195 /*
196  * TCP attaches to socket via pru_attach(), reserving space,
197  * and an internet control block.  This socket may move to
198  * other CPU later when we bind/connect.
199  */
200 static void
201 tcp_usr_attach(netmsg_t msg)
202 {
203 	struct socket *so = msg->base.nm_so;
204 	struct pru_attach_info *ai = msg->attach.nm_ai;
205 	int error;
206 	struct inpcb *inp;
207 	struct tcpcb *tp = NULL;
208 	TCPDEBUG0;
209 
210 	inp = so->so_pcb;
211 	KASSERT(inp == NULL, ("tcp socket attached"));
212 	TCPDEBUG1();
213 
214 	error = tcp_attach(so, ai);
215 	if (error)
216 		goto out;
217 
218 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
219 		so->so_linger = TCP_LINGERTIME;
220 	tp = sototcpcb(so);
221 out:
222 	TCPDEBUG2(PRU_ATTACH);
223 	lwkt_replymsg(&msg->lmsg, error);
224 }
225 
226 /*
227  * pru_detach() detaches the TCP protocol from the socket.
228  * If the protocol state is non-embryonic, then can't
229  * do this directly: have to initiate a pru_disconnect(),
230  * which may finish later; embryonic TCB's can just
231  * be discarded here.
232  */
233 static void
234 tcp_usr_detach(netmsg_t msg)
235 {
236 	struct socket *so = msg->base.nm_so;
237 	int error = 0;
238 	struct inpcb *inp;
239 	struct tcpcb *tp;
240 	TCPDEBUG0;
241 
242 	inp = so->so_pcb;
243 
244 	/*
245 	 * If the inp is already detached or never attached, it may have
246 	 * been due to an async close or async attach failure.  Just return
247 	 * as if no error occured.
248 	 */
249 	if (inp) {
250 		tp = intotcpcb(inp);
251 		KASSERT(tp != NULL, ("tcp_usr_detach: tp is NULL"));
252 		TCPDEBUG1();
253 		tp = tcp_disconnect(tp);
254 		TCPDEBUG2(PRU_DETACH);
255 	}
256 	lwkt_replymsg(&msg->lmsg, error);
257 }
258 
259 /*
260  * NOTE: ignore_error is non-zero for certain disconnection races
261  * which we want to silently allow, otherwise close() may return
262  * an unexpected error.
263  *
264  * NOTE: The variables (msg) and (tp) are assumed.
265  */
266 #define	COMMON_START(so, inp, ignore_error)			\
267 	TCPDEBUG0; 						\
268 								\
269 	inp = so->so_pcb; 					\
270 	do {							\
271 		if (inp == NULL) {				\
272 			error = ignore_error ? 0 : EINVAL;	\
273 			tp = NULL;				\
274 			goto out;				\
275 		}						\
276 		tp = intotcpcb(inp);				\
277 		TCPDEBUG1();					\
278 	} while(0)
279 
280 #define COMMON_END1(req, noreply)				\
281 	out: do {						\
282 		TCPDEBUG2(req);					\
283 		if (!(noreply))					\
284 			lwkt_replymsg(&msg->lmsg, error);	\
285 		return;						\
286 	} while(0)
287 
288 #define COMMON_END(req)		COMMON_END1((req), 0)
289 
290 /*
291  * Give the socket an address.
292  */
293 static void
294 tcp_usr_bind(netmsg_t msg)
295 {
296 	struct socket *so = msg->bind.base.nm_so;
297 	struct sockaddr *nam = msg->bind.nm_nam;
298 	struct thread *td = msg->bind.nm_td;
299 	int error = 0;
300 	struct inpcb *inp;
301 	struct tcpcb *tp;
302 	struct sockaddr_in *sinp;
303 
304 	COMMON_START(so, inp, 0);
305 
306 	/*
307 	 * Must check for multicast addresses and disallow binding
308 	 * to them.
309 	 */
310 	sinp = (struct sockaddr_in *)nam;
311 	if (sinp->sin_family == AF_INET &&
312 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
313 		error = EAFNOSUPPORT;
314 		goto out;
315 	}
316 	error = in_pcbbind(inp, nam, td);
317 	if (error)
318 		goto out;
319 
320 	COMMON_END(PRU_BIND);
321 }
322 
323 #ifdef INET6
324 
325 static void
326 tcp6_usr_bind(netmsg_t msg)
327 {
328 	struct socket *so = msg->bind.base.nm_so;
329 	struct sockaddr *nam = msg->bind.nm_nam;
330 	struct thread *td = msg->bind.nm_td;
331 	int error = 0;
332 	struct inpcb *inp;
333 	struct tcpcb *tp;
334 	struct sockaddr_in6 *sin6p;
335 
336 	COMMON_START(so, inp, 0);
337 
338 	/*
339 	 * Must check for multicast addresses and disallow binding
340 	 * to them.
341 	 */
342 	sin6p = (struct sockaddr_in6 *)nam;
343 	if (sin6p->sin6_family == AF_INET6 &&
344 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
345 		error = EAFNOSUPPORT;
346 		goto out;
347 	}
348 	error = in6_pcbbind(inp, nam, td);
349 	if (error)
350 		goto out;
351 	COMMON_END(PRU_BIND);
352 }
353 #endif /* INET6 */
354 
355 struct netmsg_inswildcard {
356 	struct netmsg_base	base;
357 	struct inpcb		*nm_inp;
358 };
359 
360 static void
361 in_pcbinswildcardhash_handler(netmsg_t msg)
362 {
363 	struct netmsg_inswildcard *nm = (struct netmsg_inswildcard *)msg;
364 	int cpu = mycpuid, nextcpu;
365 
366 	in_pcbinswildcardhash_oncpu(nm->nm_inp, &tcbinfo[cpu]);
367 
368 	nextcpu = cpu + 1;
369 	if (nextcpu < ncpus2)
370 		lwkt_forwardmsg(netisr_cpuport(nextcpu), &nm->base.lmsg);
371 	else
372 		lwkt_replymsg(&nm->base.lmsg, 0);
373 }
374 
375 static void
376 tcp_sosetport(struct lwkt_msg *msg, lwkt_port_t port)
377 {
378 	sosetport(((struct netmsg_base *)msg)->nm_so, port);
379 }
380 
381 /*
382  * Prepare to accept connections.
383  */
384 static void
385 tcp_usr_listen(netmsg_t msg)
386 {
387 	struct socket *so = msg->listen.base.nm_so;
388 	struct thread *td = msg->listen.nm_td;
389 	int error = 0;
390 	struct inpcb *inp;
391 	struct tcpcb *tp;
392 	struct netmsg_inswildcard nm;
393 	lwkt_port_t port0 = netisr_cpuport(0);
394 
395 	COMMON_START(so, inp, 0);
396 
397 	if (&curthread->td_msgport != port0) {
398 		lwkt_msg_t lmsg = &msg->listen.base.lmsg;
399 
400 		KASSERT((msg->listen.nm_flags & PRUL_RELINK) == 0,
401 		    ("already asked to relink"));
402 
403 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpuid]);
404 		msg->listen.nm_flags |= PRUL_RELINK;
405 
406 		/* See the related comment in tcp_connect() */
407 		lwkt_setmsg_receipt(lmsg, tcp_sosetport);
408 		lwkt_forwardmsg(port0, lmsg);
409 		/* msg invalid now */
410 		return;
411 	}
412 	KASSERT(so->so_port == port0, ("so_port is not netisr0"));
413 
414 	if (msg->listen.nm_flags & PRUL_RELINK) {
415 		msg->listen.nm_flags &= ~PRUL_RELINK;
416 		in_pcblink(so->so_pcb, &tcbinfo[mycpuid]);
417 	}
418 	KASSERT(inp->inp_pcbinfo == &tcbinfo[0], ("pcbinfo is not tcbinfo0"));
419 
420 	if (tp->t_flags & TF_LISTEN)
421 		goto out;
422 
423 	if (inp->inp_lport == 0) {
424 		error = in_pcbbind(inp, NULL, td);
425 		if (error)
426 			goto out;
427 	}
428 
429 	tp->t_state = TCPS_LISTEN;
430 	tp->t_flags |= TF_LISTEN;
431 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
432 
433 	if (ncpus2 > 1) {
434 		/*
435 		 * Put this inpcb into wildcard hash on other cpus.
436 		 */
437 		ASSERT_INP_NOTINHASH(inp);
438 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
439 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
440 		nm.nm_inp = inp;
441 		lwkt_domsg(netisr_cpuport(1), &nm.base.lmsg, 0);
442 	}
443 	in_pcbinswildcardhash(inp);
444 	COMMON_END(PRU_LISTEN);
445 }
446 
447 #ifdef INET6
448 
449 static void
450 tcp6_usr_listen(netmsg_t msg)
451 {
452 	struct socket *so = msg->listen.base.nm_so;
453 	struct thread *td = msg->listen.nm_td;
454 	int error = 0;
455 	struct inpcb *inp;
456 	struct tcpcb *tp;
457 	struct netmsg_inswildcard nm;
458 
459 	COMMON_START(so, inp, 0);
460 
461 	if (tp->t_flags & TF_LISTEN)
462 		goto out;
463 
464 	if (inp->inp_lport == 0) {
465 		error = in6_pcbbind(inp, NULL, td);
466 		if (error)
467 			goto out;
468 	}
469 
470 	tp->t_state = TCPS_LISTEN;
471 	tp->t_flags |= TF_LISTEN;
472 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
473 
474 	if (ncpus2 > 1) {
475 		/*
476 		 * Put this inpcb into wildcard hash on other cpus.
477 		 */
478 		KKASSERT(so->so_port == netisr_cpuport(0));
479 		ASSERT_IN_NETISR(0);
480 		KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
481 		ASSERT_INP_NOTINHASH(inp);
482 
483 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
484 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
485 		nm.nm_inp = inp;
486 		lwkt_domsg(netisr_cpuport(1), &nm.base.lmsg, 0);
487 	}
488 	in_pcbinswildcardhash(inp);
489 	COMMON_END(PRU_LISTEN);
490 }
491 #endif /* INET6 */
492 
493 /*
494  * Initiate connection to peer.
495  * Create a template for use in transmissions on this connection.
496  * Enter SYN_SENT state, and mark socket as connecting.
497  * Start keep-alive timer, and seed output sequence space.
498  * Send initial segment on connection.
499  */
500 static void
501 tcp_usr_connect(netmsg_t msg)
502 {
503 	struct socket *so = msg->connect.base.nm_so;
504 	struct sockaddr *nam = msg->connect.nm_nam;
505 	struct thread *td = msg->connect.nm_td;
506 	int error = 0;
507 	struct inpcb *inp;
508 	struct tcpcb *tp;
509 	struct sockaddr_in *sinp;
510 
511 	COMMON_START(so, inp, 0);
512 
513 	/*
514 	 * Must disallow TCP ``connections'' to multicast addresses.
515 	 */
516 	sinp = (struct sockaddr_in *)nam;
517 	if (sinp->sin_family == AF_INET
518 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
519 		error = EAFNOSUPPORT;
520 		goto out;
521 	}
522 
523 	if (!prison_remote_ip(td, (struct sockaddr*)sinp)) {
524 		error = EAFNOSUPPORT; /* IPv6 only jail */
525 		goto out;
526 	}
527 
528 	tcp_connect(msg);
529 	/* msg is invalid now */
530 	return;
531 out:
532 	if (msg->connect.nm_m) {
533 		m_freem(msg->connect.nm_m);
534 		msg->connect.nm_m = NULL;
535 	}
536 	if (msg->connect.nm_flags & PRUC_HELDTD)
537 		lwkt_rele(td);
538 	if (error && (msg->connect.nm_flags & PRUC_ASYNC)) {
539 		so->so_error = error;
540 		soisdisconnected(so);
541 	}
542 	lwkt_replymsg(&msg->lmsg, error);
543 }
544 
545 #ifdef INET6
546 
547 static void
548 tcp6_usr_connect(netmsg_t msg)
549 {
550 	struct socket *so = msg->connect.base.nm_so;
551 	struct sockaddr *nam = msg->connect.nm_nam;
552 	struct thread *td = msg->connect.nm_td;
553 	int error = 0;
554 	struct inpcb *inp;
555 	struct tcpcb *tp;
556 	struct sockaddr_in6 *sin6p;
557 
558 	COMMON_START(so, inp, 0);
559 
560 	/*
561 	 * Must disallow TCP ``connections'' to multicast addresses.
562 	 */
563 	sin6p = (struct sockaddr_in6 *)nam;
564 	if (sin6p->sin6_family == AF_INET6
565 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
566 		error = EAFNOSUPPORT;
567 		goto out;
568 	}
569 
570 	if (!prison_remote_ip(td, nam)) {
571 		error = EAFNOSUPPORT; /* IPv4 only jail */
572 		goto out;
573 	}
574 
575 	/* Reject v4-mapped address */
576 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
577 		error = EADDRNOTAVAIL;
578 		goto out;
579 	}
580 
581 	inp->inp_inc.inc_isipv6 = 1;
582 	tcp6_connect(msg);
583 	/* msg is invalid now */
584 	return;
585 out:
586 	if (msg->connect.nm_m) {
587 		m_freem(msg->connect.nm_m);
588 		msg->connect.nm_m = NULL;
589 	}
590 	lwkt_replymsg(&msg->lmsg, error);
591 }
592 
593 #endif /* INET6 */
594 
595 /*
596  * Initiate disconnect from peer.
597  * If connection never passed embryonic stage, just drop;
598  * else if don't need to let data drain, then can just drop anyways,
599  * else have to begin TCP shutdown process: mark socket disconnecting,
600  * drain unread data, state switch to reflect user close, and
601  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
602  * when peer sends FIN and acks ours.
603  *
604  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
605  */
606 static void
607 tcp_usr_disconnect(netmsg_t msg)
608 {
609 	struct socket *so = msg->disconnect.base.nm_so;
610 	int error = 0;
611 	struct inpcb *inp;
612 	struct tcpcb *tp;
613 
614 	COMMON_START(so, inp, 1);
615 	tp = tcp_disconnect(tp);
616 	COMMON_END(PRU_DISCONNECT);
617 }
618 
619 /*
620  * Accept a connection.  Essentially all the work is
621  * done at higher levels; just return the address
622  * of the peer, storing through addr.
623  */
624 static void
625 tcp_usr_accept(netmsg_t msg)
626 {
627 	struct socket *so = msg->accept.base.nm_so;
628 	struct sockaddr **nam = msg->accept.nm_nam;
629 	int error = 0;
630 	struct inpcb *inp;
631 	struct tcpcb *tp = NULL;
632 	TCPDEBUG0;
633 
634 	inp = so->so_pcb;
635 	if (so->so_state & SS_ISDISCONNECTED) {
636 		error = ECONNABORTED;
637 		goto out;
638 	}
639 	if (inp == NULL) {
640 		error = EINVAL;
641 		goto out;
642 	}
643 
644 	tp = intotcpcb(inp);
645 	TCPDEBUG1();
646 	in_setpeeraddr(so, nam);
647 	COMMON_END(PRU_ACCEPT);
648 }
649 
650 #ifdef INET6
651 static void
652 tcp6_usr_accept(netmsg_t msg)
653 {
654 	struct socket *so = msg->accept.base.nm_so;
655 	struct sockaddr **nam = msg->accept.nm_nam;
656 	int error = 0;
657 	struct inpcb *inp;
658 	struct tcpcb *tp = NULL;
659 	TCPDEBUG0;
660 
661 	inp = so->so_pcb;
662 
663 	if (so->so_state & SS_ISDISCONNECTED) {
664 		error = ECONNABORTED;
665 		goto out;
666 	}
667 	if (inp == NULL) {
668 		error = EINVAL;
669 		goto out;
670 	}
671 	tp = intotcpcb(inp);
672 	TCPDEBUG1();
673 	in6_setpeeraddr(so, nam);
674 	COMMON_END(PRU_ACCEPT);
675 }
676 #endif /* INET6 */
677 
678 /*
679  * Mark the connection as being incapable of further output.
680  */
681 static void
682 tcp_usr_shutdown(netmsg_t msg)
683 {
684 	struct socket *so = msg->shutdown.base.nm_so;
685 	int error = 0;
686 	struct inpcb *inp;
687 	struct tcpcb *tp;
688 
689 	COMMON_START(so, inp, 0);
690 	socantsendmore(so);
691 	tp = tcp_usrclosed(tp);
692 	if (tp)
693 		error = tcp_output(tp);
694 	COMMON_END(PRU_SHUTDOWN);
695 }
696 
697 /*
698  * After a receive, possibly send window update to peer.
699  */
700 static void
701 tcp_usr_rcvd(netmsg_t msg)
702 {
703 	struct socket *so = msg->rcvd.base.nm_so;
704 	int error = 0, noreply = 0;
705 	struct inpcb *inp;
706 	struct tcpcb *tp;
707 
708 	COMMON_START(so, inp, 0);
709 
710 	if (msg->rcvd.nm_pru_flags & PRUR_ASYNC) {
711 		noreply = 1;
712 		so_async_rcvd_reply(so);
713 	}
714 	tcp_output(tp);
715 
716 	COMMON_END1(PRU_RCVD, noreply);
717 }
718 
719 /*
720  * Do a send by putting data in output queue and updating urgent
721  * marker if URG set.  Possibly send more data.  Unlike the other
722  * pru_*() routines, the mbuf chains are our responsibility.  We
723  * must either enqueue them or free them.  The other pru_* routines
724  * generally are caller-frees.
725  */
726 static void
727 tcp_usr_send(netmsg_t msg)
728 {
729 	struct socket *so = msg->send.base.nm_so;
730 	int flags = msg->send.nm_flags;
731 	struct mbuf *m = msg->send.nm_m;
732 	int error = 0;
733 	struct inpcb *inp;
734 	struct tcpcb *tp;
735 	TCPDEBUG0;
736 
737 	KKASSERT(msg->send.nm_control == NULL);
738 	KKASSERT(msg->send.nm_addr == NULL);
739 	KKASSERT((flags & PRUS_FREEADDR) == 0);
740 
741 	inp = so->so_pcb;
742 
743 	if (inp == NULL) {
744 		/*
745 		 * OOPS! we lost a race, the TCP session got reset after
746 		 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a
747 		 * network interrupt in the non-critical section of sosend().
748 		 */
749 		m_freem(m);
750 		error = ECONNRESET;	/* XXX EPIPE? */
751 		tp = NULL;
752 		TCPDEBUG1();
753 		goto out;
754 	}
755 	tp = intotcpcb(inp);
756 	TCPDEBUG1();
757 
758 #ifdef foo
759 	/*
760 	 * This is no longer necessary, since:
761 	 * - sosendtcp() has already checked it for us
762 	 * - It does not work with asynchronized send
763 	 */
764 
765 	/*
766 	 * Don't let too much OOB data build up
767 	 */
768 	if (flags & PRUS_OOB) {
769 		if (ssb_space(&so->so_snd) < -512) {
770 			m_freem(m);
771 			error = ENOBUFS;
772 			goto out;
773 		}
774 	}
775 #endif
776 
777 	/*
778 	 * Pump the data into the socket.
779 	 */
780 	if (m) {
781 		ssb_appendstream(&so->so_snd, m);
782 		sowwakeup(so);
783 	}
784 	if (flags & PRUS_OOB) {
785 		/*
786 		 * According to RFC961 (Assigned Protocols),
787 		 * the urgent pointer points to the last octet
788 		 * of urgent data.  We continue, however,
789 		 * to consider it to indicate the first octet
790 		 * of data past the urgent section.
791 		 * Otherwise, snd_up should be one lower.
792 		 */
793 		tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
794 		tp->t_flags |= TF_FORCE;
795 		error = tcp_output(tp);
796 		tp->t_flags &= ~TF_FORCE;
797 	} else {
798 		if (flags & PRUS_EOF) {
799 			/*
800 			 * Close the send side of the connection after
801 			 * the data is sent.
802 			 */
803 			socantsendmore(so);
804 			tp = tcp_usrclosed(tp);
805 		}
806 		if (tp != NULL && !tcp_output_pending(tp)) {
807 			if (flags & PRUS_MORETOCOME)
808 				tp->t_flags |= TF_MORETOCOME;
809 			error = tcp_output_fair(tp);
810 			if (flags & PRUS_MORETOCOME)
811 				tp->t_flags &= ~TF_MORETOCOME;
812 		}
813 	}
814 	COMMON_END1((flags & PRUS_OOB) ? PRU_SENDOOB :
815 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND),
816 		   (flags & PRUS_NOREPLY));
817 }
818 
819 /*
820  * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
821  *	 will sofree() it when we return.
822  */
823 static void
824 tcp_usr_abort(netmsg_t msg)
825 {
826 	struct socket *so = msg->abort.base.nm_so;
827 	int error = 0;
828 	struct inpcb *inp;
829 	struct tcpcb *tp;
830 
831 	COMMON_START(so, inp, 1);
832 	tp = tcp_drop(tp, ECONNABORTED);
833 	COMMON_END(PRU_ABORT);
834 }
835 
836 /*
837  * Receive out-of-band data.
838  */
839 static void
840 tcp_usr_rcvoob(netmsg_t msg)
841 {
842 	struct socket *so = msg->rcvoob.base.nm_so;
843 	struct mbuf *m = msg->rcvoob.nm_m;
844 	int flags = msg->rcvoob.nm_flags;
845 	int error = 0;
846 	struct inpcb *inp;
847 	struct tcpcb *tp;
848 
849 	COMMON_START(so, inp, 0);
850 	if ((so->so_oobmark == 0 &&
851 	     (so->so_state & SS_RCVATMARK) == 0) ||
852 	    so->so_options & SO_OOBINLINE ||
853 	    tp->t_oobflags & TCPOOB_HADDATA) {
854 		error = EINVAL;
855 		goto out;
856 	}
857 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
858 		error = EWOULDBLOCK;
859 		goto out;
860 	}
861 	m->m_len = 1;
862 	*mtod(m, caddr_t) = tp->t_iobc;
863 	if ((flags & MSG_PEEK) == 0)
864 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
865 	COMMON_END(PRU_RCVOOB);
866 }
867 
868 static void
869 tcp_usr_savefaddr(struct socket *so, const struct sockaddr *faddr)
870 {
871 	in_savefaddr(so, faddr);
872 }
873 
874 #ifdef INET6
875 static void
876 tcp6_usr_savefaddr(struct socket *so, const struct sockaddr *faddr)
877 {
878 	in6_savefaddr(so, faddr);
879 }
880 #endif
881 
882 static int
883 tcp_usr_preconnect(struct socket *so, const struct sockaddr *nam,
884     struct thread *td __unused)
885 {
886 	const struct sockaddr_in *sinp;
887 
888 	sinp = (const struct sockaddr_in *)nam;
889 	if (sinp->sin_family == AF_INET &&
890 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
891 		return EAFNOSUPPORT;
892 
893 	soisconnecting(so);
894 	return 0;
895 }
896 
897 /* xxx - should be const */
898 struct pr_usrreqs tcp_usrreqs = {
899 	.pru_abort = tcp_usr_abort,
900 	.pru_accept = tcp_usr_accept,
901 	.pru_attach = tcp_usr_attach,
902 	.pru_bind = tcp_usr_bind,
903 	.pru_connect = tcp_usr_connect,
904 	.pru_connect2 = pr_generic_notsupp,
905 	.pru_control = in_control_dispatch,
906 	.pru_detach = tcp_usr_detach,
907 	.pru_disconnect = tcp_usr_disconnect,
908 	.pru_listen = tcp_usr_listen,
909 	.pru_peeraddr = in_setpeeraddr_dispatch,
910 	.pru_rcvd = tcp_usr_rcvd,
911 	.pru_rcvoob = tcp_usr_rcvoob,
912 	.pru_send = tcp_usr_send,
913 	.pru_sense = pru_sense_null,
914 	.pru_shutdown = tcp_usr_shutdown,
915 	.pru_sockaddr = in_setsockaddr_dispatch,
916 	.pru_sosend = sosendtcp,
917 	.pru_soreceive = sorecvtcp,
918 	.pru_savefaddr = tcp_usr_savefaddr,
919 	.pru_preconnect = tcp_usr_preconnect,
920 	.pru_preattach = tcp_usr_preattach
921 };
922 
923 #ifdef INET6
924 struct pr_usrreqs tcp6_usrreqs = {
925 	.pru_abort = tcp_usr_abort,
926 	.pru_accept = tcp6_usr_accept,
927 	.pru_attach = tcp_usr_attach,
928 	.pru_bind = tcp6_usr_bind,
929 	.pru_connect = tcp6_usr_connect,
930 	.pru_connect2 = pr_generic_notsupp,
931 	.pru_control = in6_control_dispatch,
932 	.pru_detach = tcp_usr_detach,
933 	.pru_disconnect = tcp_usr_disconnect,
934 	.pru_listen = tcp6_usr_listen,
935 	.pru_peeraddr = in6_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 = in6_setsockaddr_dispatch,
942 	.pru_sosend = sosendtcp,
943 	.pru_soreceive = sorecvtcp,
944 	.pru_savefaddr = tcp6_usr_savefaddr
945 };
946 #endif /* INET6 */
947 
948 static int
949 tcp_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf *m,
950 		  struct sockaddr_in *sin, struct sockaddr_in *if_sin)
951 {
952 	struct inpcb *inp = tp->t_inpcb, *oinp;
953 	struct socket *so = inp->inp_socket;
954 	struct route *ro = &inp->inp_route;
955 
956 	KASSERT(inp->inp_pcbinfo == &tcbinfo[mycpu->gd_cpuid],
957 	    ("pcbinfo mismatch"));
958 
959 	oinp = in_pcblookup_hash(inp->inp_pcbinfo,
960 				 sin->sin_addr, sin->sin_port,
961 				 (inp->inp_laddr.s_addr != INADDR_ANY ?
962 				  inp->inp_laddr : if_sin->sin_addr),
963 				inp->inp_lport, 0, NULL);
964 	if (oinp != NULL) {
965 		m_freem(m);
966 		return (EADDRINUSE);
967 	}
968 	if (inp->inp_laddr.s_addr == INADDR_ANY)
969 		inp->inp_laddr = if_sin->sin_addr;
970 	inp->inp_faddr = sin->sin_addr;
971 	inp->inp_fport = sin->sin_port;
972 	in_pcbinsconnhash(inp);
973 
974 	/*
975 	 * We are now on the inpcb's owner CPU, if the cached route was
976 	 * freed because the rtentry's owner CPU is not the current CPU
977 	 * (e.g. in tcp_connect()), then we try to reallocate it here with
978 	 * the hope that a rtentry may be cloned from a RTF_PRCLONING
979 	 * rtentry.
980 	 */
981 	if (!(inp->inp_socket->so_options & SO_DONTROUTE) && /*XXX*/
982 	    ro->ro_rt == NULL) {
983 		bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
984 		ro->ro_dst.sa_family = AF_INET;
985 		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
986 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr =
987 			sin->sin_addr;
988 		rtalloc(ro);
989 	}
990 
991 	/*
992 	 * Now that no more errors can occur, change the protocol processing
993 	 * port to the current thread (which is the correct thread).
994 	 *
995 	 * Create TCP timer message now; we are on the tcpcb's owner
996 	 * CPU/thread.
997 	 */
998 	tcp_create_timermsg(tp, &curthread->td_msgport);
999 
1000 	/*
1001 	 * Compute window scaling to request.  Use a larger scaling then
1002 	 * needed for the initial receive buffer in case the receive buffer
1003 	 * gets expanded.
1004 	 */
1005 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1006 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1007 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1008 	       (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat
1009 	) {
1010 		tp->request_r_scale++;
1011 	}
1012 
1013 	soisconnecting(so);
1014 	tcpstat.tcps_connattempt++;
1015 	tp->t_state = TCPS_SYN_SENT;
1016 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1017 	tp->iss = tcp_new_isn(tp);
1018 	tcp_sendseqinit(tp);
1019 	if (m) {
1020 		ssb_appendstream(&so->so_snd, m);
1021 		m = NULL;
1022 		if (flags & PRUS_OOB)
1023 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1024 	}
1025 
1026 	/*
1027 	 * Close the send side of the connection after
1028 	 * the data is sent if flagged.
1029 	 */
1030 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1031 		socantsendmore(so);
1032 		tp = tcp_usrclosed(tp);
1033 	}
1034 	return (tcp_output(tp));
1035 }
1036 
1037 /*
1038  * Common subroutine to open a TCP connection to remote host specified
1039  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1040  * port number if needed.  Call in_pcbladdr to do the routing and to choose
1041  * a local host address (interface).
1042  * Initialize connection parameters and enter SYN-SENT state.
1043  */
1044 static void
1045 tcp_connect(netmsg_t msg)
1046 {
1047 	struct socket *so = msg->connect.base.nm_so;
1048 	struct sockaddr *nam = msg->connect.nm_nam;
1049 	struct thread *td = msg->connect.nm_td;
1050 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
1051 	struct sockaddr_in *if_sin = NULL;
1052 	struct inpcb *inp;
1053 	struct tcpcb *tp;
1054 	int error;
1055 	lwkt_port_t port;
1056 
1057 	COMMON_START(so, inp, 0);
1058 
1059 	/*
1060 	 * Reconnect our pcb if we have to
1061 	 */
1062 	if (msg->connect.nm_flags & PRUC_RECONNECT) {
1063 		msg->connect.nm_flags &= ~PRUC_RECONNECT;
1064 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1065 	}
1066 
1067 	/*
1068 	 * Bind if we have to
1069 	 */
1070 	if (inp->inp_lport == 0) {
1071 		if (tcp_lport_extension) {
1072 			KKASSERT(inp->inp_laddr.s_addr == INADDR_ANY);
1073 
1074 			error = in_pcbladdr(inp, nam, &if_sin, td);
1075 			if (error)
1076 				goto out;
1077 			inp->inp_laddr.s_addr = if_sin->sin_addr.s_addr;
1078 
1079 			error = in_pcbbind_remote(inp, nam, td);
1080 			if (error)
1081 				goto out;
1082 
1083 			msg->connect.nm_flags |= PRUC_HASLADDR;
1084 		} else {
1085 			error = in_pcbbind(inp, NULL, td);
1086 			if (error)
1087 				goto out;
1088 		}
1089 	}
1090 
1091 	if ((msg->connect.nm_flags & PRUC_HASLADDR) == 0) {
1092 		/*
1093 		 * Calculate the correct protocol processing thread.  The
1094 		 * connect operation must run there.  Set the forwarding
1095 		 * port before we forward the message or it will get bounced
1096 		 * right back to us.
1097 		 */
1098 		error = in_pcbladdr(inp, nam, &if_sin, td);
1099 		if (error)
1100 			goto out;
1101 	}
1102 	KKASSERT(inp->inp_socket == so);
1103 
1104 	port = tcp_addrport(sin->sin_addr.s_addr, sin->sin_port,
1105 			    (inp->inp_laddr.s_addr != INADDR_ANY ?
1106 			     inp->inp_laddr.s_addr : if_sin->sin_addr.s_addr),
1107 			    inp->inp_lport);
1108 
1109 	if (port != &curthread->td_msgport) {
1110 		lwkt_msg_t lmsg = &msg->connect.base.lmsg;
1111 
1112 		/*
1113 		 * in_pcbladdr() may have allocated a route entry for us
1114 		 * on the current CPU, but we need a route entry on the
1115 		 * inpcb's owner CPU, so free it here.
1116 		 */
1117 		in_pcbresetroute(inp);
1118 
1119 		/*
1120 		 * We are moving the protocol processing port the socket
1121 		 * is on, we have to unlink here and re-link on the
1122 		 * target cpu.
1123 		 */
1124 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1125 		msg->connect.nm_flags |= PRUC_RECONNECT;
1126 		msg->connect.base.nm_dispatch = tcp_connect;
1127 
1128 		/*
1129 		 * Use message put done receipt to change this socket's
1130 		 * so_port, i.e. _after_ this message was put onto the
1131 		 * target netisr's msgport but _before_ the message could
1132 		 * be pulled from the target netisr's msgport, so that:
1133 		 * - The upper half (socket code) will not see the new
1134 		 *   msgport before this message reaches the new msgport
1135 		 *   and messages for this socket will be ordered.
1136 		 * - This message will see the new msgport, when its
1137 		 *   handler is called in the target netisr.
1138 		 *
1139 		 * NOTE:
1140 		 * We MUST use messege put done receipt to change this
1141 		 * socket's so_port:
1142 		 * If we changed the so_port in this netisr after the
1143 		 * lwkt_forwardmsg (so messages for this socket will be
1144 		 * ordered) and changed the so_port in the target netisr
1145 		 * at the very beginning of this message's handler, we
1146 		 * would suffer so_port overwritten race, given this
1147 		 * message might be forwarded again.
1148 		 *
1149 		 * NOTE:
1150 		 * This mechanism depends on that the netisr's msgport
1151 		 * is spin msgport (currently it is :).
1152 		 *
1153 		 * If the upper half saw the new msgport before this
1154 		 * message reached the target netisr's msgport, the
1155 		 * messages sent from the upper half could reach the new
1156 		 * msgport before this message, thus there would be
1157 		 * message reordering.  The worst case could be soclose()
1158 		 * saw the new msgport and the detach message could reach
1159 		 * the new msgport before this message, i.e. the inpcb
1160 		 * could have been destroyed when this message was still
1161 		 * pending on or on its way to the new msgport.  Other
1162 		 * weird cases could also happen, e.g. inpcb->inp_pcbinfo,
1163 		 * since we have unlinked this inpcb from the current
1164 		 * pcbinfo first.
1165 		 */
1166 		lwkt_setmsg_receipt(lmsg, tcp_sosetport);
1167 		lwkt_forwardmsg(port, lmsg);
1168 		/* msg invalid now */
1169 		return;
1170 	} else if (msg->connect.nm_flags & PRUC_HELDTD) {
1171 		/*
1172 		 * The original thread is no longer needed; release it.
1173 		 */
1174 		lwkt_rele(td);
1175 		msg->connect.nm_flags &= ~PRUC_HELDTD;
1176 	}
1177 	error = tcp_connect_oncpu(tp, msg->connect.nm_sndflags,
1178 				  msg->connect.nm_m, sin, if_sin);
1179 	msg->connect.nm_m = NULL;
1180 out:
1181 	if (msg->connect.nm_m) {
1182 		m_freem(msg->connect.nm_m);
1183 		msg->connect.nm_m = NULL;
1184 	}
1185 	if (msg->connect.nm_flags & PRUC_HELDTD)
1186 		lwkt_rele(td);
1187 	if (error && (msg->connect.nm_flags & PRUC_ASYNC)) {
1188 		so->so_error = error;
1189 		soisdisconnected(so);
1190 	}
1191 	lwkt_replymsg(&msg->connect.base.lmsg, error);
1192 	/* msg invalid now */
1193 }
1194 
1195 #ifdef INET6
1196 
1197 static void
1198 tcp6_connect(netmsg_t msg)
1199 {
1200 	struct tcpcb *tp;
1201 	struct socket *so = msg->connect.base.nm_so;
1202 	struct sockaddr *nam = msg->connect.nm_nam;
1203 	struct thread *td = msg->connect.nm_td;
1204 	struct inpcb *inp;
1205 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1206 	struct in6_addr *addr6;
1207 	lwkt_port_t port;
1208 	int error;
1209 
1210 	COMMON_START(so, inp, 0);
1211 
1212 	/*
1213 	 * Reconnect our pcb if we have to
1214 	 */
1215 	if (msg->connect.nm_flags & PRUC_RECONNECT) {
1216 		msg->connect.nm_flags &= ~PRUC_RECONNECT;
1217 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1218 	}
1219 
1220 	/*
1221 	 * Bind if we have to
1222 	 */
1223 	if (inp->inp_lport == 0) {
1224 		error = in6_pcbbind(inp, NULL, td);
1225 		if (error)
1226 			goto out;
1227 	}
1228 
1229 	/*
1230 	 * Cannot simply call in_pcbconnect, because there might be an
1231 	 * earlier incarnation of this same connection still in
1232 	 * TIME_WAIT state, creating an ADDRINUSE error.
1233 	 */
1234 	error = in6_pcbladdr(inp, nam, &addr6, td);
1235 	if (error)
1236 		goto out;
1237 
1238 	port = tcp6_addrport();	/* XXX hack for now, always cpu0 */
1239 
1240 	if (port != &curthread->td_msgport) {
1241 		lwkt_msg_t lmsg = &msg->connect.base.lmsg;
1242 
1243 		/*
1244 		 * in_pcbladdr() may have allocated a route entry for us
1245 		 * on the current CPU, but we need a route entry on the
1246 		 * inpcb's owner CPU, so free it here.
1247 		 */
1248 		in_pcbresetroute(inp);
1249 
1250 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1251 		msg->connect.nm_flags |= PRUC_RECONNECT;
1252 		msg->connect.base.nm_dispatch = tcp6_connect;
1253 
1254 		/* See the related comment in tcp_connect() */
1255 		lwkt_setmsg_receipt(lmsg, tcp_sosetport);
1256 		lwkt_forwardmsg(port, lmsg);
1257 		/* msg invalid now */
1258 		return;
1259 	}
1260 	error = tcp6_connect_oncpu(tp, msg->connect.nm_sndflags,
1261 				   &msg->connect.nm_m, sin6, addr6);
1262 	/* nm_m may still be intact */
1263 out:
1264 	if (msg->connect.nm_m) {
1265 		m_freem(msg->connect.nm_m);
1266 		msg->connect.nm_m = NULL;
1267 	}
1268 	lwkt_replymsg(&msg->connect.base.lmsg, error);
1269 	/* msg invalid now */
1270 }
1271 
1272 static int
1273 tcp6_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf **mp,
1274 		   struct sockaddr_in6 *sin6, struct in6_addr *addr6)
1275 {
1276 	struct mbuf *m = *mp;
1277 	struct inpcb *inp = tp->t_inpcb;
1278 	struct socket *so = inp->inp_socket;
1279 	struct inpcb *oinp;
1280 
1281 	/*
1282 	 * Cannot simply call in_pcbconnect, because there might be an
1283 	 * earlier incarnation of this same connection still in
1284 	 * TIME_WAIT state, creating an ADDRINUSE error.
1285 	 */
1286 	oinp = in6_pcblookup_hash(inp->inp_pcbinfo,
1287 				  &sin6->sin6_addr, sin6->sin6_port,
1288 				  (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ?
1289 				      addr6 : &inp->in6p_laddr),
1290 				  inp->inp_lport,  0, NULL);
1291 	if (oinp)
1292 		return (EADDRINUSE);
1293 
1294 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1295 		inp->in6p_laddr = *addr6;
1296 	inp->in6p_faddr = sin6->sin6_addr;
1297 	inp->inp_fport = sin6->sin6_port;
1298 	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != 0)
1299 		inp->in6p_flowinfo = sin6->sin6_flowinfo;
1300 	in_pcbinsconnhash(inp);
1301 
1302 	/*
1303 	 * Now that no more errors can occur, change the protocol processing
1304 	 * port to the current thread (which is the correct thread).
1305 	 *
1306 	 * Create TCP timer message now; we are on the tcpcb's owner
1307 	 * CPU/thread.
1308 	 */
1309 	tcp_create_timermsg(tp, &curthread->td_msgport);
1310 
1311 	/* Compute window scaling to request.  */
1312 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1313 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1314 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1315 	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat) {
1316 		tp->request_r_scale++;
1317 	}
1318 
1319 	soisconnecting(so);
1320 	tcpstat.tcps_connattempt++;
1321 	tp->t_state = TCPS_SYN_SENT;
1322 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1323 	tp->iss = tcp_new_isn(tp);
1324 	tcp_sendseqinit(tp);
1325 	if (m) {
1326 		ssb_appendstream(&so->so_snd, m);
1327 		*mp = NULL;
1328 		if (flags & PRUS_OOB)
1329 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1330 	}
1331 
1332 	/*
1333 	 * Close the send side of the connection after
1334 	 * the data is sent if flagged.
1335 	 */
1336 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1337 		socantsendmore(so);
1338 		tp = tcp_usrclosed(tp);
1339 	}
1340 	return (tcp_output(tp));
1341 }
1342 
1343 #endif /* INET6 */
1344 
1345 /*
1346  * The new sockopt interface makes it possible for us to block in the
1347  * copyin/out step (if we take a page fault).  Taking a page fault while
1348  * in a critical section is probably a Bad Thing.  (Since sockets and pcbs
1349  * both now use TSM, there probably isn't any need for this function to
1350  * run in a critical section any more.  This needs more examination.)
1351  */
1352 void
1353 tcp_ctloutput(netmsg_t msg)
1354 {
1355 	struct socket *so = msg->base.nm_so;
1356 	struct sockopt *sopt = msg->ctloutput.nm_sopt;
1357 	int	error, opt, optval, opthz;
1358 	struct	inpcb *inp;
1359 	struct	tcpcb *tp;
1360 
1361 	error = 0;
1362 	inp = so->so_pcb;
1363 	if (inp == NULL) {
1364 		error = ECONNRESET;
1365 		goto done;
1366 	}
1367 	tp = intotcpcb(inp);
1368 
1369 	/* Get socket's owner cpuid hint */
1370 	if (sopt->sopt_level == SOL_SOCKET &&
1371 	    sopt->sopt_dir == SOPT_GET &&
1372 	    sopt->sopt_name == SO_CPUHINT) {
1373 		if (tp->t_flags & TF_LISTEN) {
1374 			/*
1375 			 * Listen sockets owner cpuid is always 0,
1376 			 * which does not make sense if SO_REUSEPORT
1377 			 * is not set.
1378 			 */
1379 			if (so->so_options & SO_REUSEPORT)
1380 				optval = (inp->inp_lgrpindex & ncpus2_mask);
1381 			else
1382 				optval = -1; /* no hint */
1383 		} else {
1384 			optval = mycpuid;
1385 		}
1386 		soopt_from_kbuf(sopt, &optval, sizeof(optval));
1387 		goto done;
1388 	}
1389 
1390 	if (sopt->sopt_level != IPPROTO_TCP) {
1391 		if (sopt->sopt_level == IPPROTO_IP) {
1392 			switch (sopt->sopt_name) {
1393 			case IP_MULTICAST_IF:
1394 			case IP_MULTICAST_VIF:
1395 			case IP_MULTICAST_TTL:
1396 			case IP_MULTICAST_LOOP:
1397 			case IP_ADD_MEMBERSHIP:
1398 			case IP_DROP_MEMBERSHIP:
1399 				/*
1400 				 * Multicast does not make sense on
1401 				 * TCP sockets.
1402 				 */
1403 				error = EOPNOTSUPP;
1404 				goto done;
1405 			}
1406 		}
1407 #ifdef INET6
1408 		if (INP_CHECK_SOCKAF(so, AF_INET6))
1409 			ip6_ctloutput_dispatch(msg);
1410 		else
1411 #endif /* INET6 */
1412 		ip_ctloutput(msg);
1413 		/* msg invalid now */
1414 		return;
1415 	}
1416 
1417 	switch (sopt->sopt_dir) {
1418 	case SOPT_SET:
1419 		error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1420 				      sizeof optval);
1421 		if (error)
1422 			break;
1423 		switch (sopt->sopt_name) {
1424 		case TCP_FASTKEEP:
1425 			if (optval > 0)
1426 				tp->t_keepidle = tp->t_keepintvl;
1427 			else
1428 				tp->t_keepidle = tcp_keepidle;
1429 			tcp_timer_keep_activity(tp, 0);
1430 			break;
1431 #ifdef TCP_SIGNATURE
1432 		case TCP_SIGNATURE_ENABLE:
1433 			if (tp->t_state == TCPS_CLOSED) {
1434 				/*
1435 				 * This is the only safe state that this
1436 				 * option could be changed.  Some segments
1437 				 * could already have been sent in other
1438 				 * states.
1439 				 */
1440 				if (optval > 0)
1441 					tp->t_flags |= TF_SIGNATURE;
1442 				else
1443 					tp->t_flags &= ~TF_SIGNATURE;
1444 			} else {
1445 				error = EOPNOTSUPP;
1446 			}
1447 			break;
1448 #endif /* TCP_SIGNATURE */
1449 		case TCP_NODELAY:
1450 		case TCP_NOOPT:
1451 			switch (sopt->sopt_name) {
1452 			case TCP_NODELAY:
1453 				opt = TF_NODELAY;
1454 				break;
1455 			case TCP_NOOPT:
1456 				opt = TF_NOOPT;
1457 				break;
1458 			default:
1459 				opt = 0; /* dead code to fool gcc */
1460 				break;
1461 			}
1462 
1463 			if (optval)
1464 				tp->t_flags |= opt;
1465 			else
1466 				tp->t_flags &= ~opt;
1467 			break;
1468 
1469 		case TCP_NOPUSH:
1470 			if (tcp_disable_nopush)
1471 				break;
1472 			if (optval)
1473 				tp->t_flags |= TF_NOPUSH;
1474 			else {
1475 				tp->t_flags &= ~TF_NOPUSH;
1476 				error = tcp_output(tp);
1477 			}
1478 			break;
1479 
1480 		case TCP_MAXSEG:
1481 			/*
1482 			 * Must be between 0 and maxseg.  If the requested
1483 			 * maxseg is too small to satisfy the desired minmss,
1484 			 * pump it up (silently so sysctl modifications of
1485 			 * minmss do not create unexpected program failures).
1486 			 * Handle degenerate cases.
1487 			 */
1488 			if (optval > 0 && optval <= tp->t_maxseg) {
1489 				if (optval + 40 < tcp_minmss) {
1490 					optval = tcp_minmss - 40;
1491 					if (optval < 0)
1492 						optval = 1;
1493 				}
1494 				tp->t_maxseg = optval;
1495 			} else {
1496 				error = EINVAL;
1497 			}
1498 			break;
1499 
1500 		case TCP_KEEPINIT:
1501 			opthz = ((int64_t)optval * hz) / 1000;
1502 			if (opthz >= 1)
1503 				tp->t_keepinit = opthz;
1504 			else
1505 				error = EINVAL;
1506 			break;
1507 
1508 		case TCP_KEEPIDLE:
1509 			opthz = ((int64_t)optval * hz) / 1000;
1510 			if (opthz >= 1) {
1511 				tp->t_keepidle = opthz;
1512 				tcp_timer_keep_activity(tp, 0);
1513 			} else {
1514 				error = EINVAL;
1515 			}
1516 			break;
1517 
1518 		case TCP_KEEPINTVL:
1519 			opthz = ((int64_t)optval * hz) / 1000;
1520 			if (opthz >= 1) {
1521 				tp->t_keepintvl = opthz;
1522 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1523 			} else {
1524 				error = EINVAL;
1525 			}
1526 			break;
1527 
1528 		case TCP_KEEPCNT:
1529 			if (optval > 0) {
1530 				tp->t_keepcnt = optval;
1531 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1532 			} else {
1533 				error = EINVAL;
1534 			}
1535 			break;
1536 
1537 		default:
1538 			error = ENOPROTOOPT;
1539 			break;
1540 		}
1541 		break;
1542 
1543 	case SOPT_GET:
1544 		switch (sopt->sopt_name) {
1545 #ifdef TCP_SIGNATURE
1546 		case TCP_SIGNATURE_ENABLE:
1547 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1548 			break;
1549 #endif /* TCP_SIGNATURE */
1550 		case TCP_NODELAY:
1551 			optval = tp->t_flags & TF_NODELAY;
1552 			break;
1553 		case TCP_MAXSEG:
1554 			optval = tp->t_maxseg;
1555 			break;
1556 		case TCP_NOOPT:
1557 			optval = tp->t_flags & TF_NOOPT;
1558 			break;
1559 		case TCP_NOPUSH:
1560 			optval = tp->t_flags & TF_NOPUSH;
1561 			break;
1562 		case TCP_KEEPINIT:
1563 			optval = ((int64_t)tp->t_keepinit * 1000) / hz;
1564 			break;
1565 		case TCP_KEEPIDLE:
1566 			optval = ((int64_t)tp->t_keepidle * 1000) / hz;
1567 			break;
1568 		case TCP_KEEPINTVL:
1569 			optval = ((int64_t)tp->t_keepintvl * 1000) / hz;
1570 			break;
1571 		case TCP_KEEPCNT:
1572 			optval = tp->t_keepcnt;
1573 			break;
1574 		default:
1575 			error = ENOPROTOOPT;
1576 			break;
1577 		}
1578 		if (error == 0)
1579 			soopt_from_kbuf(sopt, &optval, sizeof optval);
1580 		break;
1581 	}
1582 done:
1583 	lwkt_replymsg(&msg->lmsg, error);
1584 }
1585 
1586 /*
1587  * tcp_sendspace and tcp_recvspace are the default send and receive window
1588  * sizes, respectively.  These are obsolescent (this information should
1589  * be set by the route).
1590  *
1591  * Use a default that does not require tcp window scaling to be turned
1592  * on.  Individual programs or the administrator can increase the default.
1593  */
1594 u_long	tcp_sendspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1595 SYSCTL_INT(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1596     &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1597 u_long	tcp_recvspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1598 SYSCTL_INT(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1599     &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1600 
1601 /*
1602  * Attach TCP protocol to socket, allocating internet protocol control
1603  * block, tcp control block, buffer space, and entering CLOSED state.
1604  */
1605 static int
1606 tcp_attach(struct socket *so, struct pru_attach_info *ai)
1607 {
1608 	struct tcpcb *tp;
1609 	struct inpcb *inp;
1610 	int error;
1611 	int cpu;
1612 #ifdef INET6
1613 	boolean_t isipv6 = INP_CHECK_SOCKAF(so, AF_INET6);
1614 #endif
1615 
1616 	if (ai != NULL) {
1617 		error = tcp_usr_preattach(so, 0 /* don't care */, ai);
1618 		if (error)
1619 			return (error);
1620 	} else {
1621 		/* Post attach; do nothing */
1622 	}
1623 
1624 	cpu = mycpu->gd_cpuid;
1625 
1626 	/*
1627 	 * Set the default pcbinfo.  This will likely change when we
1628 	 * bind/connect.
1629 	 */
1630 	error = in_pcballoc(so, &tcbinfo[cpu]);
1631 	if (error)
1632 		return (error);
1633 	inp = so->so_pcb;
1634 #ifdef INET6
1635 	if (isipv6)
1636 		inp->in6p_hops = -1;	/* use kernel default */
1637 #endif
1638 	tp = tcp_newtcpcb(inp);
1639 	KASSERT(tp != NULL, ("tcp_newtcpcb failed"));
1640 	tp->t_state = TCPS_CLOSED;
1641 	/* Keep a reference for asynchronized pru_rcvd */
1642 	soreference(so);
1643 	return (0);
1644 }
1645 
1646 /*
1647  * Initiate (or continue) disconnect.
1648  * If embryonic state, just send reset (once).
1649  * If in ``let data drain'' option and linger null, just drop.
1650  * Otherwise (hard), mark socket disconnecting and drop
1651  * current input data; switch states based on user close, and
1652  * send segment to peer (with FIN).
1653  */
1654 static struct tcpcb *
1655 tcp_disconnect(struct tcpcb *tp)
1656 {
1657 	struct socket *so = tp->t_inpcb->inp_socket;
1658 
1659 	if (tp->t_state < TCPS_ESTABLISHED) {
1660 		tp = tcp_close(tp);
1661 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1662 		tp = tcp_drop(tp, 0);
1663 	} else {
1664 		lwkt_gettoken(&so->so_rcv.ssb_token);
1665 		soisdisconnecting(so);
1666 		sbflush(&so->so_rcv.sb);
1667 		tp = tcp_usrclosed(tp);
1668 		if (tp)
1669 			tcp_output(tp);
1670 		lwkt_reltoken(&so->so_rcv.ssb_token);
1671 	}
1672 	return (tp);
1673 }
1674 
1675 /*
1676  * User issued close, and wish to trail through shutdown states:
1677  * if never received SYN, just forget it.  If got a SYN from peer,
1678  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1679  * If already got a FIN from peer, then almost done; go to LAST_ACK
1680  * state.  In all other cases, have already sent FIN to peer (e.g.
1681  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1682  * for peer to send FIN or not respond to keep-alives, etc.
1683  * We can let the user exit from the close as soon as the FIN is acked.
1684  */
1685 static struct tcpcb *
1686 tcp_usrclosed(struct tcpcb *tp)
1687 {
1688 
1689 	switch (tp->t_state) {
1690 
1691 	case TCPS_CLOSED:
1692 	case TCPS_LISTEN:
1693 		tp->t_state = TCPS_CLOSED;
1694 		tp = tcp_close(tp);
1695 		break;
1696 
1697 	case TCPS_SYN_SENT:
1698 	case TCPS_SYN_RECEIVED:
1699 		tp->t_flags |= TF_NEEDFIN;
1700 		break;
1701 
1702 	case TCPS_ESTABLISHED:
1703 		tp->t_state = TCPS_FIN_WAIT_1;
1704 		break;
1705 
1706 	case TCPS_CLOSE_WAIT:
1707 		tp->t_state = TCPS_LAST_ACK;
1708 		break;
1709 	}
1710 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1711 		soisdisconnected(tp->t_inpcb->inp_socket);
1712 		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
1713 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1714 			tcp_callout_reset(tp, tp->tt_2msl, tp->t_maxidle,
1715 			    tcp_timer_2msl);
1716 		}
1717 	}
1718 	return (tp);
1719 }
1720