xref: /dflybsd-src/sys/netinet/tcp_usrreq.c (revision 1e0f138c92f6a795c71ff7fb75d2bb7e7097db33)
1 /*
2  * Copyright (c) 2003, 2004 Jeffrey M. Hsu.  All rights reserved.
3  * Copyright (c) 2003, 2004 The DragonFly Project.  All rights reserved.
4  *
5  * This code is derived from software contributed to The DragonFly Project
6  * by Jeffrey M. Hsu.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of The DragonFly Project nor the names of its
17  *    contributors may be used to endorse or promote products derived
18  *    from this software without specific, prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1982, 1986, 1988, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *	This product includes software developed by the University of
49  *	California, Berkeley and its contributors.
50  * 4. Neither the name of the University nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64  * SUCH DAMAGE.
65  *
66  *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
67  * $FreeBSD: src/sys/netinet/tcp_usrreq.c,v 1.51.2.17 2002/10/11 11:46:44 ume Exp $
68  */
69 
70 #include "opt_ipsec.h"
71 #include "opt_inet.h"
72 #include "opt_inet6.h"
73 #include "opt_tcpdebug.h"
74 
75 #include <sys/param.h>
76 #include <sys/systm.h>
77 #include <sys/kernel.h>
78 #include <sys/malloc.h>
79 #include <sys/sysctl.h>
80 #include <sys/globaldata.h>
81 #include <sys/thread.h>
82 
83 #include <sys/mbuf.h>
84 #ifdef INET6
85 #include <sys/domain.h>
86 #endif /* INET6 */
87 #include <sys/socket.h>
88 #include <sys/socketvar.h>
89 #include <sys/protosw.h>
90 
91 #include <sys/thread2.h>
92 #include <sys/msgport2.h>
93 #include <sys/socketvar2.h>
94 
95 #include <net/if.h>
96 #include <net/netisr.h>
97 #include <net/route.h>
98 
99 #include <net/netmsg2.h>
100 
101 #include <netinet/in.h>
102 #include <netinet/in_systm.h>
103 #ifdef INET6
104 #include <netinet/ip6.h>
105 #endif
106 #include <netinet/in_pcb.h>
107 #ifdef INET6
108 #include <netinet6/in6_pcb.h>
109 #endif
110 #include <netinet/in_var.h>
111 #include <netinet/ip_var.h>
112 #ifdef INET6
113 #include <netinet6/ip6_var.h>
114 #include <netinet6/tcp6_var.h>
115 #endif
116 #include <netinet/tcp.h>
117 #include <netinet/tcp_fsm.h>
118 #include <netinet/tcp_seq.h>
119 #include <netinet/tcp_timer.h>
120 #include <netinet/tcp_timer2.h>
121 #include <netinet/tcp_var.h>
122 #include <netinet/tcpip.h>
123 #ifdef TCPDEBUG
124 #include <netinet/tcp_debug.h>
125 #endif
126 
127 #ifdef IPSEC
128 #include <netinet6/ipsec.h>
129 #endif /*IPSEC*/
130 
131 /*
132  * TCP protocol interface to socket abstraction.
133  */
134 extern	char *tcpstates[];	/* XXX ??? */
135 
136 static int	tcp_attach (struct socket *, struct pru_attach_info *);
137 static void	tcp_connect (netmsg_t msg);
138 #ifdef INET6
139 static void	tcp6_connect (netmsg_t msg);
140 static int	tcp6_connect_oncpu(struct tcpcb *tp, int flags,
141 				struct mbuf **mp,
142 				struct sockaddr_in6 *sin6,
143 				struct in6_addr *addr6);
144 #endif /* INET6 */
145 static struct tcpcb *
146 		tcp_disconnect (struct tcpcb *);
147 static struct tcpcb *
148 		tcp_usrclosed (struct tcpcb *);
149 
150 #ifdef TCPDEBUG
151 #define	TCPDEBUG0	int ostate = 0
152 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
153 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
154 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
155 #else
156 #define	TCPDEBUG0
157 #define	TCPDEBUG1()
158 #define	TCPDEBUG2(req)
159 #endif
160 
161 static int	tcp_lport_extension = 1;
162 SYSCTL_INT(_net_inet_tcp, OID_AUTO, lportext, CTLFLAG_RW,
163     &tcp_lport_extension, 0, "");
164 
165 /*
166  * For some ill optimized programs, which try to use TCP_NOPUSH
167  * to improve performance, will have small amount of data sits
168  * in the sending buffer.  These small amount of data will _not_
169  * be pushed into the network until more data are written into
170  * the socket or the socket write side is shutdown.
171  */
172 static int	tcp_disable_nopush = 1;
173 SYSCTL_INT(_net_inet_tcp, OID_AUTO, disable_nopush, CTLFLAG_RW,
174     &tcp_disable_nopush, 0, "TCP_NOPUSH socket option will have no effect");
175 
176 /*
177  * TCP attaches to socket via pru_attach(), reserving space,
178  * and an internet control block.  This is likely occuring on
179  * cpu0 and may have to move later when we bind/connect.
180  */
181 static void
182 tcp_usr_attach(netmsg_t msg)
183 {
184 	struct socket *so = msg->base.nm_so;
185 	struct pru_attach_info *ai = msg->attach.nm_ai;
186 	int error;
187 	struct inpcb *inp;
188 	struct tcpcb *tp = NULL;
189 	TCPDEBUG0;
190 
191 	soreference(so);
192 	inp = so->so_pcb;
193 	TCPDEBUG1();
194 	if (inp) {
195 		error = EISCONN;
196 		goto out;
197 	}
198 
199 	error = tcp_attach(so, ai);
200 	if (error)
201 		goto out;
202 
203 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
204 		so->so_linger = TCP_LINGERTIME;
205 	tp = sototcpcb(so);
206 out:
207 	sofree(so);		/* from ref above */
208 	TCPDEBUG2(PRU_ATTACH);
209 	lwkt_replymsg(&msg->lmsg, error);
210 }
211 
212 /*
213  * pru_detach() detaches the TCP protocol from the socket.
214  * If the protocol state is non-embryonic, then can't
215  * do this directly: have to initiate a pru_disconnect(),
216  * which may finish later; embryonic TCB's can just
217  * be discarded here.
218  */
219 static void
220 tcp_usr_detach(netmsg_t msg)
221 {
222 	struct socket *so = msg->base.nm_so;
223 	int error = 0;
224 	struct inpcb *inp;
225 	struct tcpcb *tp;
226 	TCPDEBUG0;
227 
228 	inp = so->so_pcb;
229 
230 	/*
231 	 * If the inp is already detached it may have been due to an async
232 	 * close.  Just return as if no error occured.
233 	 *
234 	 * It's possible for the tcpcb (tp) to disconnect from the inp due
235 	 * to tcp_drop()->tcp_close() being called.  This may occur *after*
236 	 * the detach message has been queued so we may find a NULL tp here.
237 	 */
238 	if (inp) {
239 		if ((tp = intotcpcb(inp)) != NULL) {
240 			TCPDEBUG1();
241 			tp = tcp_disconnect(tp);
242 			TCPDEBUG2(PRU_DETACH);
243 		}
244 	}
245 	lwkt_replymsg(&msg->lmsg, error);
246 }
247 
248 /*
249  * NOTE: ignore_error is non-zero for certain disconnection races
250  * which we want to silently allow, otherwise close() may return
251  * an unexpected error.
252  *
253  * NOTE: The variables (msg) and (tp) are assumed.
254  */
255 #define	COMMON_START(so, inp, ignore_error)			\
256 	TCPDEBUG0; 						\
257 								\
258 	inp = so->so_pcb; 					\
259 	do {							\
260 		 if (inp == NULL) {				\
261 			error = ignore_error ? 0 : EINVAL;	\
262 			tp = NULL;				\
263 			goto out;				\
264 		 }						\
265 		 tp = intotcpcb(inp);				\
266 		 TCPDEBUG1();					\
267 	} while(0)
268 
269 #define COMMON_END1(req, noreply)				\
270 	out: do {						\
271 		TCPDEBUG2(req);					\
272 		if (!(noreply))					\
273 			lwkt_replymsg(&msg->lmsg, error);	\
274 		return;						\
275 	} while(0)
276 
277 #define COMMON_END(req)		COMMON_END1((req), 0)
278 
279 /*
280  * Give the socket an address.
281  */
282 static void
283 tcp_usr_bind(netmsg_t msg)
284 {
285 	struct socket *so = msg->bind.base.nm_so;
286 	struct sockaddr *nam = msg->bind.nm_nam;
287 	struct thread *td = msg->bind.nm_td;
288 	int error = 0;
289 	struct inpcb *inp;
290 	struct tcpcb *tp;
291 	struct sockaddr_in *sinp;
292 
293 	COMMON_START(so, inp, 0);
294 
295 	/*
296 	 * Must check for multicast addresses and disallow binding
297 	 * to them.
298 	 */
299 	sinp = (struct sockaddr_in *)nam;
300 	if (sinp->sin_family == AF_INET &&
301 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
302 		error = EAFNOSUPPORT;
303 		goto out;
304 	}
305 	error = in_pcbbind(inp, nam, td);
306 	if (error)
307 		goto out;
308 	COMMON_END(PRU_BIND);
309 
310 }
311 
312 #ifdef INET6
313 
314 static void
315 tcp6_usr_bind(netmsg_t msg)
316 {
317 	struct socket *so = msg->bind.base.nm_so;
318 	struct sockaddr *nam = msg->bind.nm_nam;
319 	struct thread *td = msg->bind.nm_td;
320 	int error = 0;
321 	struct inpcb *inp;
322 	struct tcpcb *tp;
323 	struct sockaddr_in6 *sin6p;
324 
325 	COMMON_START(so, inp, 0);
326 
327 	/*
328 	 * Must check for multicast addresses and disallow binding
329 	 * to them.
330 	 */
331 	sin6p = (struct sockaddr_in6 *)nam;
332 	if (sin6p->sin6_family == AF_INET6 &&
333 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
334 		error = EAFNOSUPPORT;
335 		goto out;
336 	}
337 	inp->inp_vflag &= ~INP_IPV4;
338 	inp->inp_vflag |= INP_IPV6;
339 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
340 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
341 			inp->inp_vflag |= INP_IPV4;
342 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
343 			struct sockaddr_in sin;
344 
345 			in6_sin6_2_sin(&sin, sin6p);
346 			inp->inp_vflag |= INP_IPV4;
347 			inp->inp_vflag &= ~INP_IPV6;
348 			error = in_pcbbind(inp, (struct sockaddr *)&sin, td);
349 			goto out;
350 		}
351 	}
352 	error = in6_pcbbind(inp, nam, td);
353 	if (error)
354 		goto out;
355 	COMMON_END(PRU_BIND);
356 }
357 #endif /* INET6 */
358 
359 #ifdef SMP
360 
361 struct netmsg_inswildcard {
362 	struct netmsg_base	base;
363 	struct inpcb		*nm_inp;
364 };
365 
366 static void
367 in_pcbinswildcardhash_handler(netmsg_t msg)
368 {
369 	struct netmsg_inswildcard *nm = (struct netmsg_inswildcard *)msg;
370 	int cpu = mycpuid, nextcpu;
371 
372 	in_pcbinswildcardhash_oncpu(nm->nm_inp, &tcbinfo[cpu]);
373 
374 	nextcpu = cpu + 1;
375 	if (nextcpu < ncpus2)
376 		lwkt_forwardmsg(cpu_portfn(nextcpu), &nm->base.lmsg);
377 	else
378 		lwkt_replymsg(&nm->base.lmsg, 0);
379 }
380 
381 #endif
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 #ifdef SMP
395 	struct netmsg_inswildcard nm;
396 #endif
397 
398 	COMMON_START(so, inp, 0);
399 
400 	if (tp->t_flags & TF_LISTEN)
401 		goto out;
402 
403 	if (inp->inp_lport == 0) {
404 		error = in_pcbbind(inp, NULL, td);
405 		if (error)
406 			goto out;
407 	}
408 
409 	tp->t_state = TCPS_LISTEN;
410 	tp->t_flags |= TF_LISTEN;
411 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
412 
413 #ifdef SMP
414 	if (ncpus > 1) {
415 		/*
416 		 * We have to set the flag because we can't have other cpus
417 		 * messing with our inp's flags.
418 		 */
419 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
420 			("already on connhash"));
421 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
422 			("already on wildcardhash"));
423 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
424 			("already on MP wildcardhash"));
425 		inp->inp_flags |= INP_WILDCARD_MP;
426 
427 		KKASSERT(so->so_port == cpu_portfn(0));
428 		KKASSERT(&curthread->td_msgport == cpu_portfn(0));
429 		KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
430 
431 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
432 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
433 		nm.nm_inp = inp;
434 		lwkt_domsg(cpu_portfn(1), &nm.base.lmsg, 0);
435 	}
436 #endif
437 	in_pcbinswildcardhash(inp);
438 	COMMON_END(PRU_LISTEN);
439 }
440 
441 #ifdef INET6
442 
443 static void
444 tcp6_usr_listen(netmsg_t msg)
445 {
446 	struct socket *so = msg->listen.base.nm_so;
447 	struct thread *td = msg->listen.nm_td;
448 	int error = 0;
449 	struct inpcb *inp;
450 	struct tcpcb *tp;
451 #ifdef SMP
452 	struct netmsg_inswildcard nm;
453 #endif
454 
455 	COMMON_START(so, inp, 0);
456 
457 	if (tp->t_flags & TF_LISTEN)
458 		goto out;
459 
460 	if (inp->inp_lport == 0) {
461 		if (!(inp->inp_flags & IN6P_IPV6_V6ONLY))
462 			inp->inp_vflag |= INP_IPV4;
463 		else
464 			inp->inp_vflag &= ~INP_IPV4;
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 #ifdef SMP
475 	if (ncpus > 1) {
476 		/*
477 		 * We have to set the flag because we can't have other cpus
478 		 * messing with our inp's flags.
479 		 */
480 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
481 			("already on connhash"));
482 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
483 			("already on wildcardhash"));
484 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
485 			("already on MP wildcardhash"));
486 		inp->inp_flags |= INP_WILDCARD_MP;
487 
488 		KKASSERT(so->so_port == cpu_portfn(0));
489 		KKASSERT(&curthread->td_msgport == cpu_portfn(0));
490 		KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
491 
492 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
493 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
494 		nm.nm_inp = inp;
495 		lwkt_domsg(cpu_portfn(1), &nm.base.lmsg, 0);
496 	}
497 #endif
498 	in_pcbinswildcardhash(inp);
499 	COMMON_END(PRU_LISTEN);
500 }
501 #endif /* INET6 */
502 
503 /*
504  * Initiate connection to peer.
505  * Create a template for use in transmissions on this connection.
506  * Enter SYN_SENT state, and mark socket as connecting.
507  * Start keep-alive timer, and seed output sequence space.
508  * Send initial segment on connection.
509  */
510 static void
511 tcp_usr_connect(netmsg_t msg)
512 {
513 	struct socket *so = msg->connect.base.nm_so;
514 	struct sockaddr *nam = msg->connect.nm_nam;
515 	struct thread *td = msg->connect.nm_td;
516 	int error = 0;
517 	struct inpcb *inp;
518 	struct tcpcb *tp;
519 	struct sockaddr_in *sinp;
520 
521 	COMMON_START(so, inp, 0);
522 
523 	/*
524 	 * Must disallow TCP ``connections'' to multicast addresses.
525 	 */
526 	sinp = (struct sockaddr_in *)nam;
527 	if (sinp->sin_family == AF_INET
528 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
529 		error = EAFNOSUPPORT;
530 		goto out;
531 	}
532 
533 	if (!prison_remote_ip(td, (struct sockaddr*)sinp)) {
534 		error = EAFNOSUPPORT; /* IPv6 only jail */
535 		goto out;
536 	}
537 
538 	tcp_connect(msg);
539 	/* msg is invalid now */
540 	return;
541 out:
542 	if (msg->connect.nm_m) {
543 		m_freem(msg->connect.nm_m);
544 		msg->connect.nm_m = NULL;
545 	}
546 	lwkt_replymsg(&msg->lmsg, error);
547 }
548 
549 #ifdef INET6
550 
551 static void
552 tcp6_usr_connect(netmsg_t msg)
553 {
554 	struct socket *so = msg->connect.base.nm_so;
555 	struct sockaddr *nam = msg->connect.nm_nam;
556 	struct thread *td = msg->connect.nm_td;
557 	int error = 0;
558 	struct inpcb *inp;
559 	struct tcpcb *tp;
560 	struct sockaddr_in6 *sin6p;
561 
562 	COMMON_START(so, inp, 0);
563 
564 	/*
565 	 * Must disallow TCP ``connections'' to multicast addresses.
566 	 */
567 	sin6p = (struct sockaddr_in6 *)nam;
568 	if (sin6p->sin6_family == AF_INET6
569 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
570 		error = EAFNOSUPPORT;
571 		goto out;
572 	}
573 
574 	if (!prison_remote_ip(td, nam)) {
575 		error = EAFNOSUPPORT; /* IPv4 only jail */
576 		goto out;
577 	}
578 
579 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
580 		struct sockaddr_in *sinp;
581 
582 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
583 			error = EINVAL;
584 			goto out;
585 		}
586 		sinp = kmalloc(sizeof(*sinp), M_LWKTMSG, M_INTWAIT);
587 		in6_sin6_2_sin(sinp, sin6p);
588 		inp->inp_vflag |= INP_IPV4;
589 		inp->inp_vflag &= ~INP_IPV6;
590 		msg->connect.nm_nam = (struct sockaddr *)sinp;
591 		msg->connect.nm_reconnect |= NMSG_RECONNECT_NAMALLOC;
592 		tcp_connect(msg);
593 		/* msg is invalid now */
594 		return;
595 	}
596 	inp->inp_vflag &= ~INP_IPV4;
597 	inp->inp_vflag |= INP_IPV6;
598 	inp->inp_inc.inc_isipv6 = 1;
599 
600 	msg->connect.nm_reconnect |= NMSG_RECONNECT_FALLBACK;
601 	tcp6_connect(msg);
602 	/* msg is invalid now */
603 	return;
604 out:
605 	if (msg->connect.nm_m) {
606 		m_freem(msg->connect.nm_m);
607 		msg->connect.nm_m = NULL;
608 	}
609 	lwkt_replymsg(&msg->lmsg, error);
610 }
611 
612 #endif /* INET6 */
613 
614 /*
615  * Initiate disconnect from peer.
616  * If connection never passed embryonic stage, just drop;
617  * else if don't need to let data drain, then can just drop anyways,
618  * else have to begin TCP shutdown process: mark socket disconnecting,
619  * drain unread data, state switch to reflect user close, and
620  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
621  * when peer sends FIN and acks ours.
622  *
623  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
624  */
625 static void
626 tcp_usr_disconnect(netmsg_t msg)
627 {
628 	struct socket *so = msg->disconnect.base.nm_so;
629 	int error = 0;
630 	struct inpcb *inp;
631 	struct tcpcb *tp;
632 
633 	COMMON_START(so, inp, 1);
634 	tp = tcp_disconnect(tp);
635 	COMMON_END(PRU_DISCONNECT);
636 }
637 
638 /*
639  * Accept a connection.  Essentially all the work is
640  * done at higher levels; just return the address
641  * of the peer, storing through addr.
642  */
643 static void
644 tcp_usr_accept(netmsg_t msg)
645 {
646 	struct socket *so = msg->accept.base.nm_so;
647 	struct sockaddr **nam = msg->accept.nm_nam;
648 	int error = 0;
649 	struct inpcb *inp;
650 	struct tcpcb *tp = NULL;
651 	TCPDEBUG0;
652 
653 	inp = so->so_pcb;
654 	if (so->so_state & SS_ISDISCONNECTED) {
655 		error = ECONNABORTED;
656 		goto out;
657 	}
658 	if (inp == 0) {
659 		error = EINVAL;
660 		goto out;
661 	}
662 
663 	tp = intotcpcb(inp);
664 	TCPDEBUG1();
665 	in_setpeeraddr(so, nam);
666 	COMMON_END(PRU_ACCEPT);
667 }
668 
669 #ifdef INET6
670 static void
671 tcp6_usr_accept(netmsg_t msg)
672 {
673 	struct socket *so = msg->accept.base.nm_so;
674 	struct sockaddr **nam = msg->accept.nm_nam;
675 	int error = 0;
676 	struct inpcb *inp;
677 	struct tcpcb *tp = NULL;
678 	TCPDEBUG0;
679 
680 	inp = so->so_pcb;
681 
682 	if (so->so_state & SS_ISDISCONNECTED) {
683 		error = ECONNABORTED;
684 		goto out;
685 	}
686 	if (inp == 0) {
687 		error = EINVAL;
688 		goto out;
689 	}
690 	tp = intotcpcb(inp);
691 	TCPDEBUG1();
692 	in6_mapped_peeraddr(so, nam);
693 	COMMON_END(PRU_ACCEPT);
694 }
695 #endif /* INET6 */
696 /*
697  * Mark the connection as being incapable of further output.
698  */
699 static void
700 tcp_usr_shutdown(netmsg_t msg)
701 {
702 	struct socket *so = msg->shutdown.base.nm_so;
703 	int error = 0;
704 	struct inpcb *inp;
705 	struct tcpcb *tp;
706 
707 	COMMON_START(so, inp, 0);
708 	socantsendmore(so);
709 	tp = tcp_usrclosed(tp);
710 	if (tp)
711 		error = tcp_output(tp);
712 	COMMON_END(PRU_SHUTDOWN);
713 }
714 
715 /*
716  * After a receive, possibly send window update to peer.
717  */
718 static void
719 tcp_usr_rcvd(netmsg_t msg)
720 {
721 	struct socket *so = msg->rcvd.base.nm_so;
722 	int error = 0;
723 	struct inpcb *inp;
724 	struct tcpcb *tp;
725 
726 	COMMON_START(so, inp, 0);
727 	tcp_output(tp);
728 	COMMON_END(PRU_RCVD);
729 }
730 
731 /*
732  * Do a send by putting data in output queue and updating urgent
733  * marker if URG set.  Possibly send more data.  Unlike the other
734  * pru_*() routines, the mbuf chains are our responsibility.  We
735  * must either enqueue them or free them.  The other pru_* routines
736  * generally are caller-frees.
737  */
738 static void
739 tcp_usr_send(netmsg_t msg)
740 {
741 	struct socket *so = msg->send.base.nm_so;
742 	int flags = msg->send.nm_flags;
743 	struct mbuf *m = msg->send.nm_m;
744 	int error = 0;
745 	struct inpcb *inp;
746 	struct tcpcb *tp;
747 	TCPDEBUG0;
748 
749 	KKASSERT(msg->send.nm_control == NULL);
750 	KKASSERT(msg->send.nm_addr == NULL);
751 	KKASSERT((flags & PRUS_FREEADDR) == 0);
752 
753 	inp = so->so_pcb;
754 
755 	if (inp == NULL) {
756 		/*
757 		 * OOPS! we lost a race, the TCP session got reset after
758 		 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a
759 		 * network interrupt in the non-critical section of sosend().
760 		 */
761 		m_freem(m);
762 		error = ECONNRESET;	/* XXX EPIPE? */
763 		tp = NULL;
764 		TCPDEBUG1();
765 		goto out;
766 	}
767 	tp = intotcpcb(inp);
768 	TCPDEBUG1();
769 
770 #ifdef foo
771 	/*
772 	 * This is no longer necessary, since:
773 	 * - sosendtcp() has already checked it for us
774 	 * - It does not work with asynchronized send
775 	 */
776 
777 	/*
778 	 * Don't let too much OOB data build up
779 	 */
780 	if (flags & PRUS_OOB) {
781 		if (ssb_space(&so->so_snd) < -512) {
782 			m_freem(m);
783 			error = ENOBUFS;
784 			goto out;
785 		}
786 	}
787 #endif
788 
789 	/*
790 	 * Pump the data into the socket.
791 	 */
792 	if (m)
793 		ssb_appendstream(&so->so_snd, m);
794 	if (flags & PRUS_OOB) {
795 		/*
796 		 * According to RFC961 (Assigned Protocols),
797 		 * the urgent pointer points to the last octet
798 		 * of urgent data.  We continue, however,
799 		 * to consider it to indicate the first octet
800 		 * of data past the urgent section.
801 		 * Otherwise, snd_up should be one lower.
802 		 */
803 		tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
804 		tp->t_flags |= TF_FORCE;
805 		error = tcp_output(tp);
806 		tp->t_flags &= ~TF_FORCE;
807 	} else {
808 		if (flags & PRUS_EOF) {
809 			/*
810 			 * Close the send side of the connection after
811 			 * the data is sent.
812 			 */
813 			socantsendmore(so);
814 			tp = tcp_usrclosed(tp);
815 		}
816 		if (tp != NULL) {
817 			if (flags & PRUS_MORETOCOME)
818 				tp->t_flags |= TF_MORETOCOME;
819 			error = tcp_output(tp);
820 			if (flags & PRUS_MORETOCOME)
821 				tp->t_flags &= ~TF_MORETOCOME;
822 		}
823 	}
824 	COMMON_END1((flags & PRUS_OOB) ? PRU_SENDOOB :
825 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND),
826 		   (flags & PRUS_NOREPLY));
827 }
828 
829 /*
830  * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
831  *	 will sofree() it when we return.
832  */
833 static void
834 tcp_usr_abort(netmsg_t msg)
835 {
836 	struct socket *so = msg->abort.base.nm_so;
837 	int error = 0;
838 	struct inpcb *inp;
839 	struct tcpcb *tp;
840 
841 	COMMON_START(so, inp, 1);
842 	tp = tcp_drop(tp, ECONNABORTED);
843 	COMMON_END(PRU_ABORT);
844 }
845 
846 /*
847  * Receive out-of-band data.
848  */
849 static void
850 tcp_usr_rcvoob(netmsg_t msg)
851 {
852 	struct socket *so = msg->rcvoob.base.nm_so;
853 	struct mbuf *m = msg->rcvoob.nm_m;
854 	int flags = msg->rcvoob.nm_flags;
855 	int error = 0;
856 	struct inpcb *inp;
857 	struct tcpcb *tp;
858 
859 	COMMON_START(so, inp, 0);
860 	if ((so->so_oobmark == 0 &&
861 	     (so->so_state & SS_RCVATMARK) == 0) ||
862 	    so->so_options & SO_OOBINLINE ||
863 	    tp->t_oobflags & TCPOOB_HADDATA) {
864 		error = EINVAL;
865 		goto out;
866 	}
867 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
868 		error = EWOULDBLOCK;
869 		goto out;
870 	}
871 	m->m_len = 1;
872 	*mtod(m, caddr_t) = tp->t_iobc;
873 	if ((flags & MSG_PEEK) == 0)
874 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
875 	COMMON_END(PRU_RCVOOB);
876 }
877 
878 static void
879 tcp_usr_savefaddr(struct socket *so, const struct sockaddr *faddr)
880 {
881 	in_savefaddr(so, faddr);
882 }
883 
884 #ifdef INET6
885 static void
886 tcp6_usr_savefaddr(struct socket *so, const struct sockaddr *faddr)
887 {
888 	in6_mapped_savefaddr(so, faddr);
889 }
890 #endif
891 
892 /* xxx - should be const */
893 struct pr_usrreqs tcp_usrreqs = {
894 	.pru_abort = tcp_usr_abort,
895 	.pru_accept = tcp_usr_accept,
896 	.pru_attach = tcp_usr_attach,
897 	.pru_bind = tcp_usr_bind,
898 	.pru_connect = tcp_usr_connect,
899 	.pru_connect2 = pr_generic_notsupp,
900 	.pru_control = in_control_dispatch,
901 	.pru_detach = tcp_usr_detach,
902 	.pru_disconnect = tcp_usr_disconnect,
903 	.pru_listen = tcp_usr_listen,
904 	.pru_peeraddr = in_setpeeraddr_dispatch,
905 	.pru_rcvd = tcp_usr_rcvd,
906 	.pru_rcvoob = tcp_usr_rcvoob,
907 	.pru_send = tcp_usr_send,
908 	.pru_sense = pru_sense_null,
909 	.pru_shutdown = tcp_usr_shutdown,
910 	.pru_sockaddr = in_setsockaddr_dispatch,
911 	.pru_sosend = sosendtcp,
912 	.pru_soreceive = soreceive,
913 	.pru_savefaddr = tcp_usr_savefaddr
914 };
915 
916 #ifdef INET6
917 struct pr_usrreqs tcp6_usrreqs = {
918 	.pru_abort = tcp_usr_abort,
919 	.pru_accept = tcp6_usr_accept,
920 	.pru_attach = tcp_usr_attach,
921 	.pru_bind = tcp6_usr_bind,
922 	.pru_connect = tcp6_usr_connect,
923 	.pru_connect2 = pr_generic_notsupp,
924 	.pru_control = in6_control_dispatch,
925 	.pru_detach = tcp_usr_detach,
926 	.pru_disconnect = tcp_usr_disconnect,
927 	.pru_listen = tcp6_usr_listen,
928 	.pru_peeraddr = in6_mapped_peeraddr_dispatch,
929 	.pru_rcvd = tcp_usr_rcvd,
930 	.pru_rcvoob = tcp_usr_rcvoob,
931 	.pru_send = tcp_usr_send,
932 	.pru_sense = pru_sense_null,
933 	.pru_shutdown = tcp_usr_shutdown,
934 	.pru_sockaddr = in6_mapped_sockaddr_dispatch,
935 	.pru_sosend = sosendtcp,
936 	.pru_soreceive = soreceive,
937 	.pru_savefaddr = tcp6_usr_savefaddr
938 };
939 #endif /* INET6 */
940 
941 static int
942 tcp_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf *m,
943 		  struct sockaddr_in *sin, struct sockaddr_in *if_sin)
944 {
945 	struct inpcb *inp = tp->t_inpcb, *oinp;
946 	struct socket *so = inp->inp_socket;
947 	struct route *ro = &inp->inp_route;
948 
949 	oinp = in_pcblookup_hash(&tcbinfo[mycpu->gd_cpuid],
950 				 sin->sin_addr, sin->sin_port,
951 				 (inp->inp_laddr.s_addr != INADDR_ANY ?
952 				  inp->inp_laddr : if_sin->sin_addr),
953 				inp->inp_lport, 0, NULL);
954 	if (oinp != NULL) {
955 		m_freem(m);
956 		return (EADDRINUSE);
957 	}
958 	if (inp->inp_laddr.s_addr == INADDR_ANY)
959 		inp->inp_laddr = if_sin->sin_addr;
960 	inp->inp_faddr = sin->sin_addr;
961 	inp->inp_fport = sin->sin_port;
962 	inp->inp_cpcbinfo = &tcbinfo[mycpu->gd_cpuid];
963 	in_pcbinsconnhash(inp);
964 
965 	/*
966 	 * We are now on the inpcb's owner CPU, if the cached route was
967 	 * freed because the rtentry's owner CPU is not the current CPU
968 	 * (e.g. in tcp_connect()), then we try to reallocate it here with
969 	 * the hope that a rtentry may be cloned from a RTF_PRCLONING
970 	 * rtentry.
971 	 */
972 	if (!(inp->inp_socket->so_options & SO_DONTROUTE) && /*XXX*/
973 	    ro->ro_rt == NULL) {
974 		bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
975 		ro->ro_dst.sa_family = AF_INET;
976 		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
977 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr =
978 			sin->sin_addr;
979 		rtalloc(ro);
980 	}
981 
982 	/*
983 	 * Now that no more errors can occur, change the protocol processing
984 	 * port to the current thread (which is the correct thread).
985 	 *
986 	 * Create TCP timer message now; we are on the tcpcb's owner
987 	 * CPU/thread.
988 	 */
989 	tcp_create_timermsg(tp, &curthread->td_msgport);
990 
991 	/*
992 	 * Compute window scaling to request.  Use a larger scaling then
993 	 * needed for the initial receive buffer in case the receive buffer
994 	 * gets expanded.
995 	 */
996 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
997 		tp->request_r_scale = TCP_MIN_WINSHIFT;
998 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
999 	       (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat
1000 	) {
1001 		tp->request_r_scale++;
1002 	}
1003 
1004 	soisconnecting(so);
1005 	tcpstat.tcps_connattempt++;
1006 	tp->t_state = TCPS_SYN_SENT;
1007 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1008 	tp->iss = tcp_new_isn(tp);
1009 	tcp_sendseqinit(tp);
1010 	if (m) {
1011 		ssb_appendstream(&so->so_snd, m);
1012 		m = NULL;
1013 		if (flags & PRUS_OOB)
1014 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1015 	}
1016 
1017 	/*
1018 	 * Close the send side of the connection after
1019 	 * the data is sent if flagged.
1020 	 */
1021 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1022 		socantsendmore(so);
1023 		tp = tcp_usrclosed(tp);
1024 	}
1025 	return (tcp_output(tp));
1026 }
1027 
1028 /*
1029  * Common subroutine to open a TCP connection to remote host specified
1030  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
1031  * port number if needed.  Call in_pcbladdr to do the routing and to choose
1032  * a local host address (interface).
1033  * Initialize connection parameters and enter SYN-SENT state.
1034  */
1035 static void
1036 tcp_connect(netmsg_t msg)
1037 {
1038 	struct socket *so = msg->connect.base.nm_so;
1039 	struct sockaddr *nam = msg->connect.nm_nam;
1040 	struct thread *td = msg->connect.nm_td;
1041 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
1042 	struct sockaddr_in *if_sin;
1043 	struct inpcb *inp;
1044 	struct tcpcb *tp;
1045 	int error, calc_laddr = 1;
1046 #ifdef SMP
1047 	lwkt_port_t port;
1048 #endif
1049 
1050 	COMMON_START(so, inp, 0);
1051 
1052 	/*
1053 	 * Reconnect our pcb if we have to
1054 	 */
1055 	if (msg->connect.nm_reconnect & NMSG_RECONNECT_RECONNECT) {
1056 		msg->connect.nm_reconnect &= ~NMSG_RECONNECT_RECONNECT;
1057 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1058 	}
1059 
1060 	/*
1061 	 * Bind if we have to
1062 	 */
1063 	if (inp->inp_lport == 0) {
1064 		if (tcp_lport_extension) {
1065 			KKASSERT(inp->inp_laddr.s_addr == INADDR_ANY);
1066 
1067 			error = in_pcbladdr(inp, nam, &if_sin, td);
1068 			if (error)
1069 				goto out;
1070 			inp->inp_laddr.s_addr = if_sin->sin_addr.s_addr;
1071 
1072 			error = in_pcbconn_bind(inp, nam, td);
1073 			if (error)
1074 				goto out;
1075 
1076 			calc_laddr = 0;
1077 		} else {
1078 			error = in_pcbbind(inp, NULL, td);
1079 			if (error)
1080 				goto out;
1081 		}
1082 	}
1083 
1084 	if (calc_laddr) {
1085 		/*
1086 		 * Calculate the correct protocol processing thread.  The
1087 		 * connect operation must run there.  Set the forwarding
1088 		 * port before we forward the message or it will get bounced
1089 		 * right back to us.
1090 		 */
1091 		error = in_pcbladdr(inp, nam, &if_sin, td);
1092 		if (error)
1093 			goto out;
1094 	}
1095 	KKASSERT(inp->inp_socket == so);
1096 
1097 #ifdef SMP
1098 	port = tcp_addrport(sin->sin_addr.s_addr, sin->sin_port,
1099 			    (inp->inp_laddr.s_addr ?
1100 			     inp->inp_laddr.s_addr : if_sin->sin_addr.s_addr),
1101 			    inp->inp_lport);
1102 
1103 	if (port != &curthread->td_msgport) {
1104 		struct route *ro = &inp->inp_route;
1105 
1106 		/*
1107 		 * in_pcbladdr() may have allocated a route entry for us
1108 		 * on the current CPU, but we need a route entry on the
1109 		 * inpcb's owner CPU, so free it here.
1110 		 */
1111 		if (ro->ro_rt != NULL)
1112 			RTFREE(ro->ro_rt);
1113 		bzero(ro, sizeof(*ro));
1114 
1115 		/*
1116 		 * We are moving the protocol processing port the socket
1117 		 * is on, we have to unlink here and re-link on the
1118 		 * target cpu.
1119 		 */
1120 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1121 		sosetport(so, port);
1122 		msg->connect.nm_reconnect |= NMSG_RECONNECT_RECONNECT;
1123 		msg->connect.base.nm_dispatch = tcp_connect;
1124 
1125 		lwkt_forwardmsg(port, &msg->connect.base.lmsg);
1126 		/* msg invalid now */
1127 		return;
1128 	}
1129 #else
1130 	KKASSERT(so->so_port == &curthread->td_msgport);
1131 #endif
1132 	error = tcp_connect_oncpu(tp, msg->connect.nm_flags,
1133 				  msg->connect.nm_m, sin, if_sin);
1134 	msg->connect.nm_m = NULL;
1135 out:
1136 	if (msg->connect.nm_m) {
1137 		m_freem(msg->connect.nm_m);
1138 		msg->connect.nm_m = NULL;
1139 	}
1140 	if (msg->connect.nm_reconnect & NMSG_RECONNECT_NAMALLOC) {
1141 		kfree(msg->connect.nm_nam, M_LWKTMSG);
1142 		msg->connect.nm_nam = NULL;
1143 	}
1144 	lwkt_replymsg(&msg->connect.base.lmsg, error);
1145 	/* msg invalid now */
1146 }
1147 
1148 #ifdef INET6
1149 
1150 static void
1151 tcp6_connect(netmsg_t msg)
1152 {
1153 	struct tcpcb *tp;
1154 	struct socket *so = msg->connect.base.nm_so;
1155 	struct sockaddr *nam = msg->connect.nm_nam;
1156 	struct thread *td = msg->connect.nm_td;
1157 	struct inpcb *inp;
1158 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1159 	struct in6_addr *addr6;
1160 #ifdef SMP
1161 	lwkt_port_t port;
1162 #endif
1163 	int error;
1164 
1165 	COMMON_START(so, inp, 0);
1166 
1167 	/*
1168 	 * Reconnect our pcb if we have to
1169 	 */
1170 	if (msg->connect.nm_reconnect & NMSG_RECONNECT_RECONNECT) {
1171 		msg->connect.nm_reconnect &= ~NMSG_RECONNECT_RECONNECT;
1172 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1173 	}
1174 
1175 	/*
1176 	 * Bind if we have to
1177 	 */
1178 	if (inp->inp_lport == 0) {
1179 		error = in6_pcbbind(inp, NULL, td);
1180 		if (error)
1181 			goto out;
1182 	}
1183 
1184 	/*
1185 	 * Cannot simply call in_pcbconnect, because there might be an
1186 	 * earlier incarnation of this same connection still in
1187 	 * TIME_WAIT state, creating an ADDRINUSE error.
1188 	 */
1189 	error = in6_pcbladdr(inp, nam, &addr6, td);
1190 	if (error)
1191 		goto out;
1192 
1193 #ifdef SMP
1194 	port = tcp6_addrport();	/* XXX hack for now, always cpu0 */
1195 
1196 	if (port != &curthread->td_msgport) {
1197 		struct route *ro = &inp->inp_route;
1198 
1199 		/*
1200 		 * in_pcbladdr() may have allocated a route entry for us
1201 		 * on the current CPU, but we need a route entry on the
1202 		 * inpcb's owner CPU, so free it here.
1203 		 */
1204 		if (ro->ro_rt != NULL)
1205 			RTFREE(ro->ro_rt);
1206 		bzero(ro, sizeof(*ro));
1207 
1208 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1209 		sosetport(so, port);
1210 		msg->connect.nm_reconnect |= NMSG_RECONNECT_RECONNECT;
1211 		msg->connect.base.nm_dispatch = tcp6_connect;
1212 
1213 		lwkt_forwardmsg(port, &msg->connect.base.lmsg);
1214 		/* msg invalid now */
1215 		return;
1216 	}
1217 #endif
1218 	error = tcp6_connect_oncpu(tp, msg->connect.nm_flags,
1219 				   &msg->connect.nm_m, sin6, addr6);
1220 	/* nm_m may still be intact */
1221 out:
1222 	if (error && (msg->connect.nm_reconnect & NMSG_RECONNECT_FALLBACK)) {
1223 		tcp_connect(msg);
1224 		/* msg invalid now */
1225 	} else {
1226 		if (msg->connect.nm_m) {
1227 			m_freem(msg->connect.nm_m);
1228 			msg->connect.nm_m = NULL;
1229 		}
1230 		if (msg->connect.nm_reconnect & NMSG_RECONNECT_NAMALLOC) {
1231 			kfree(msg->connect.nm_nam, M_LWKTMSG);
1232 			msg->connect.nm_nam = NULL;
1233 		}
1234 		lwkt_replymsg(&msg->connect.base.lmsg, error);
1235 		/* msg invalid now */
1236 	}
1237 }
1238 
1239 static int
1240 tcp6_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf **mp,
1241 		   struct sockaddr_in6 *sin6, struct in6_addr *addr6)
1242 {
1243 	struct mbuf *m = *mp;
1244 	struct inpcb *inp = tp->t_inpcb;
1245 	struct socket *so = inp->inp_socket;
1246 	struct inpcb *oinp;
1247 
1248 	/*
1249 	 * Cannot simply call in_pcbconnect, because there might be an
1250 	 * earlier incarnation of this same connection still in
1251 	 * TIME_WAIT state, creating an ADDRINUSE error.
1252 	 */
1253 	oinp = in6_pcblookup_hash(inp->inp_cpcbinfo,
1254 				  &sin6->sin6_addr, sin6->sin6_port,
1255 				  (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ?
1256 				      addr6 : &inp->in6p_laddr),
1257 				  inp->inp_lport,  0, NULL);
1258 	if (oinp)
1259 		return (EADDRINUSE);
1260 
1261 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1262 		inp->in6p_laddr = *addr6;
1263 	inp->in6p_faddr = sin6->sin6_addr;
1264 	inp->inp_fport = sin6->sin6_port;
1265 	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != 0)
1266 		inp->in6p_flowinfo = sin6->sin6_flowinfo;
1267 	in_pcbinsconnhash(inp);
1268 
1269 	/*
1270 	 * Now that no more errors can occur, change the protocol processing
1271 	 * port to the current thread (which is the correct thread).
1272 	 *
1273 	 * Create TCP timer message now; we are on the tcpcb's owner
1274 	 * CPU/thread.
1275 	 */
1276 	tcp_create_timermsg(tp, &curthread->td_msgport);
1277 
1278 	/* Compute window scaling to request.  */
1279 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1280 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1281 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1282 	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat) {
1283 		tp->request_r_scale++;
1284 	}
1285 
1286 	soisconnecting(so);
1287 	tcpstat.tcps_connattempt++;
1288 	tp->t_state = TCPS_SYN_SENT;
1289 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1290 	tp->iss = tcp_new_isn(tp);
1291 	tcp_sendseqinit(tp);
1292 	if (m) {
1293 		ssb_appendstream(&so->so_snd, m);
1294 		*mp = NULL;
1295 		if (flags & PRUS_OOB)
1296 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1297 	}
1298 
1299 	/*
1300 	 * Close the send side of the connection after
1301 	 * the data is sent if flagged.
1302 	 */
1303 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1304 		socantsendmore(so);
1305 		tp = tcp_usrclosed(tp);
1306 	}
1307 	return (tcp_output(tp));
1308 }
1309 
1310 #endif /* INET6 */
1311 
1312 /*
1313  * The new sockopt interface makes it possible for us to block in the
1314  * copyin/out step (if we take a page fault).  Taking a page fault while
1315  * in a critical section is probably a Bad Thing.  (Since sockets and pcbs
1316  * both now use TSM, there probably isn't any need for this function to
1317  * run in a critical section any more.  This needs more examination.)
1318  */
1319 void
1320 tcp_ctloutput(netmsg_t msg)
1321 {
1322 	struct socket *so = msg->base.nm_so;
1323 	struct sockopt *sopt = msg->ctloutput.nm_sopt;
1324 	int	error, opt, optval, opthz;
1325 	struct	inpcb *inp;
1326 	struct	tcpcb *tp;
1327 
1328 	error = 0;
1329 	inp = so->so_pcb;
1330 	if (inp == NULL) {
1331 		error = ECONNRESET;
1332 		goto done;
1333 	}
1334 
1335 	if (sopt->sopt_level != IPPROTO_TCP) {
1336 #ifdef INET6
1337 		if (INP_CHECK_SOCKAF(so, AF_INET6))
1338 			ip6_ctloutput_dispatch(msg);
1339 		else
1340 #endif /* INET6 */
1341 		ip_ctloutput(msg);
1342 		/* msg invalid now */
1343 		return;
1344 	}
1345 	tp = intotcpcb(inp);
1346 
1347 	switch (sopt->sopt_dir) {
1348 	case SOPT_SET:
1349 		error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1350 				      sizeof optval);
1351 		if (error)
1352 			break;
1353 		switch (sopt->sopt_name) {
1354 		case TCP_FASTKEEP:
1355 			if (optval > 0)
1356 				tp->t_keepidle = tp->t_keepintvl;
1357 			else
1358 				tp->t_keepidle = tcp_keepidle;
1359 			tcp_timer_keep_activity(tp, 0);
1360 			break;
1361 #ifdef TCP_SIGNATURE
1362 		case TCP_SIGNATURE_ENABLE:
1363 			if (tp->t_state == TCPS_CLOSED) {
1364 				/*
1365 				 * This is the only safe state that this
1366 				 * option could be changed.  Some segments
1367 				 * could already have been sent in other
1368 				 * states.
1369 				 */
1370 				if (optval > 0)
1371 					tp->t_flags |= TF_SIGNATURE;
1372 				else
1373 					tp->t_flags &= ~TF_SIGNATURE;
1374 			} else {
1375 				error = EOPNOTSUPP;
1376 			}
1377 			break;
1378 #endif /* TCP_SIGNATURE */
1379 		case TCP_NODELAY:
1380 		case TCP_NOOPT:
1381 			switch (sopt->sopt_name) {
1382 			case TCP_NODELAY:
1383 				opt = TF_NODELAY;
1384 				break;
1385 			case TCP_NOOPT:
1386 				opt = TF_NOOPT;
1387 				break;
1388 			default:
1389 				opt = 0; /* dead code to fool gcc */
1390 				break;
1391 			}
1392 
1393 			if (optval)
1394 				tp->t_flags |= opt;
1395 			else
1396 				tp->t_flags &= ~opt;
1397 			break;
1398 
1399 		case TCP_NOPUSH:
1400 			if (tcp_disable_nopush)
1401 				break;
1402 			if (optval)
1403 				tp->t_flags |= TF_NOPUSH;
1404 			else {
1405 				tp->t_flags &= ~TF_NOPUSH;
1406 				error = tcp_output(tp);
1407 			}
1408 			break;
1409 
1410 		case TCP_MAXSEG:
1411 			/*
1412 			 * Must be between 0 and maxseg.  If the requested
1413 			 * maxseg is too small to satisfy the desired minmss,
1414 			 * pump it up (silently so sysctl modifications of
1415 			 * minmss do not create unexpected program failures).
1416 			 * Handle degenerate cases.
1417 			 */
1418 			if (optval > 0 && optval <= tp->t_maxseg) {
1419 				if (optval + 40 < tcp_minmss) {
1420 					optval = tcp_minmss - 40;
1421 					if (optval < 0)
1422 						optval = 1;
1423 				}
1424 				tp->t_maxseg = optval;
1425 			} else {
1426 				error = EINVAL;
1427 			}
1428 			break;
1429 
1430 		case TCP_KEEPINIT:
1431 			opthz = ((int64_t)optval * hz) / 1000;
1432 			if (opthz >= 1)
1433 				tp->t_keepinit = opthz;
1434 			else
1435 				error = EINVAL;
1436 			break;
1437 
1438 		case TCP_KEEPIDLE:
1439 			opthz = ((int64_t)optval * hz) / 1000;
1440 			if (opthz >= 1) {
1441 				tp->t_keepidle = opthz;
1442 				tcp_timer_keep_activity(tp, 0);
1443 			} else {
1444 				error = EINVAL;
1445 			}
1446 			break;
1447 
1448 		case TCP_KEEPINTVL:
1449 			opthz = ((int64_t)optval * hz) / 1000;
1450 			if (opthz >= 1) {
1451 				tp->t_keepintvl = opthz;
1452 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1453 			} else {
1454 				error = EINVAL;
1455 			}
1456 			break;
1457 
1458 		case TCP_KEEPCNT:
1459 			if (optval > 0) {
1460 				tp->t_keepcnt = optval;
1461 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1462 			} else {
1463 				error = EINVAL;
1464 			}
1465 			break;
1466 
1467 		default:
1468 			error = ENOPROTOOPT;
1469 			break;
1470 		}
1471 		break;
1472 
1473 	case SOPT_GET:
1474 		switch (sopt->sopt_name) {
1475 #ifdef TCP_SIGNATURE
1476 		case TCP_SIGNATURE_ENABLE:
1477 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1478 			break;
1479 #endif /* TCP_SIGNATURE */
1480 		case TCP_NODELAY:
1481 			optval = tp->t_flags & TF_NODELAY;
1482 			break;
1483 		case TCP_MAXSEG:
1484 			optval = tp->t_maxseg;
1485 			break;
1486 		case TCP_NOOPT:
1487 			optval = tp->t_flags & TF_NOOPT;
1488 			break;
1489 		case TCP_NOPUSH:
1490 			optval = tp->t_flags & TF_NOPUSH;
1491 			break;
1492 		case TCP_KEEPINIT:
1493 			optval = ((int64_t)tp->t_keepinit * 1000) / hz;
1494 			break;
1495 		case TCP_KEEPIDLE:
1496 			optval = ((int64_t)tp->t_keepidle * 1000) / hz;
1497 			break;
1498 		case TCP_KEEPINTVL:
1499 			optval = ((int64_t)tp->t_keepintvl * 1000) / hz;
1500 			break;
1501 		case TCP_KEEPCNT:
1502 			optval = tp->t_keepcnt;
1503 			break;
1504 		default:
1505 			error = ENOPROTOOPT;
1506 			break;
1507 		}
1508 		if (error == 0)
1509 			soopt_from_kbuf(sopt, &optval, sizeof optval);
1510 		break;
1511 	}
1512 done:
1513 	lwkt_replymsg(&msg->lmsg, error);
1514 }
1515 
1516 /*
1517  * tcp_sendspace and tcp_recvspace are the default send and receive window
1518  * sizes, respectively.  These are obsolescent (this information should
1519  * be set by the route).
1520  *
1521  * Use a default that does not require tcp window scaling to be turned
1522  * on.  Individual programs or the administrator can increase the default.
1523  */
1524 u_long	tcp_sendspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1525 SYSCTL_INT(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1526     &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1527 u_long	tcp_recvspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1528 SYSCTL_INT(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1529     &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1530 
1531 /*
1532  * Attach TCP protocol to socket, allocating internet protocol control
1533  * block, tcp control block, bufer space, and entering LISTEN state
1534  * if to accept connections.
1535  */
1536 static int
1537 tcp_attach(struct socket *so, struct pru_attach_info *ai)
1538 {
1539 	struct tcpcb *tp;
1540 	struct inpcb *inp;
1541 	int error;
1542 	int cpu;
1543 #ifdef INET6
1544 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
1545 #endif
1546 
1547 	if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
1548 		lwkt_gettoken(&so->so_rcv.ssb_token);
1549 		error = soreserve(so, tcp_sendspace, tcp_recvspace,
1550 				  ai->sb_rlimit);
1551 		lwkt_reltoken(&so->so_rcv.ssb_token);
1552 		if (error)
1553 			return (error);
1554 	}
1555 	atomic_set_int(&so->so_rcv.ssb_flags, SSB_AUTOSIZE);
1556 	atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOSIZE);
1557 	cpu = mycpu->gd_cpuid;
1558 
1559 	/*
1560 	 * Set the default port for protocol processing. This will likely
1561 	 * change when we connect.
1562 	 */
1563 	error = in_pcballoc(so, &tcbinfo[cpu]);
1564 	if (error)
1565 		return (error);
1566 	inp = so->so_pcb;
1567 #ifdef INET6
1568 	if (isipv6) {
1569 		inp->inp_vflag |= INP_IPV6;
1570 		inp->in6p_hops = -1;	/* use kernel default */
1571 	}
1572 	else
1573 #endif
1574 	inp->inp_vflag |= INP_IPV4;
1575 	tp = tcp_newtcpcb(inp);
1576 	if (tp == NULL) {
1577 		/*
1578 		 * Make sure the socket is destroyed by the pcbdetach.
1579 		 */
1580 		soreference(so);
1581 #ifdef INET6
1582 		if (isipv6)
1583 			in6_pcbdetach(inp);
1584 		else
1585 #endif
1586 		in_pcbdetach(inp);
1587 		sofree(so);	/* from ref above */
1588 		return (ENOBUFS);
1589 	}
1590 	tp->t_state = TCPS_CLOSED;
1591 	return (0);
1592 }
1593 
1594 /*
1595  * Initiate (or continue) disconnect.
1596  * If embryonic state, just send reset (once).
1597  * If in ``let data drain'' option and linger null, just drop.
1598  * Otherwise (hard), mark socket disconnecting and drop
1599  * current input data; switch states based on user close, and
1600  * send segment to peer (with FIN).
1601  */
1602 static struct tcpcb *
1603 tcp_disconnect(struct tcpcb *tp)
1604 {
1605 	struct socket *so = tp->t_inpcb->inp_socket;
1606 
1607 	if (tp->t_state < TCPS_ESTABLISHED) {
1608 		tp = tcp_close(tp);
1609 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1610 		tp = tcp_drop(tp, 0);
1611 	} else {
1612 		lwkt_gettoken(&so->so_rcv.ssb_token);
1613 		soisdisconnecting(so);
1614 		sbflush(&so->so_rcv.sb);
1615 		tp = tcp_usrclosed(tp);
1616 		if (tp)
1617 			tcp_output(tp);
1618 		lwkt_reltoken(&so->so_rcv.ssb_token);
1619 	}
1620 	return (tp);
1621 }
1622 
1623 /*
1624  * User issued close, and wish to trail through shutdown states:
1625  * if never received SYN, just forget it.  If got a SYN from peer,
1626  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1627  * If already got a FIN from peer, then almost done; go to LAST_ACK
1628  * state.  In all other cases, have already sent FIN to peer (e.g.
1629  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1630  * for peer to send FIN or not respond to keep-alives, etc.
1631  * We can let the user exit from the close as soon as the FIN is acked.
1632  */
1633 static struct tcpcb *
1634 tcp_usrclosed(struct tcpcb *tp)
1635 {
1636 
1637 	switch (tp->t_state) {
1638 
1639 	case TCPS_CLOSED:
1640 	case TCPS_LISTEN:
1641 		tp->t_state = TCPS_CLOSED;
1642 		tp = tcp_close(tp);
1643 		break;
1644 
1645 	case TCPS_SYN_SENT:
1646 	case TCPS_SYN_RECEIVED:
1647 		tp->t_flags |= TF_NEEDFIN;
1648 		break;
1649 
1650 	case TCPS_ESTABLISHED:
1651 		tp->t_state = TCPS_FIN_WAIT_1;
1652 		break;
1653 
1654 	case TCPS_CLOSE_WAIT:
1655 		tp->t_state = TCPS_LAST_ACK;
1656 		break;
1657 	}
1658 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1659 		soisdisconnected(tp->t_inpcb->inp_socket);
1660 		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
1661 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1662 			tcp_callout_reset(tp, tp->tt_2msl, tp->t_maxidle,
1663 			    tcp_timer_2msl);
1664 		}
1665 	}
1666 	return (tp);
1667 }
1668