xref: /dragonfly/sys/netinet/tcp_usrreq.c (revision a563ca70)
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 
163 SYSCTL_INT(_net_inet_tcp, OID_AUTO, lportext, CTLFLAG_RW,
164     &tcp_lport_extension, 0, "");
165 
166 /*
167  * TCP attaches to socket via pru_attach(), reserving space,
168  * and an internet control block.  This is likely occuring on
169  * cpu0 and may have to move later when we bind/connect.
170  */
171 static void
172 tcp_usr_attach(netmsg_t msg)
173 {
174 	struct socket *so = msg->base.nm_so;
175 	struct pru_attach_info *ai = msg->attach.nm_ai;
176 	int error;
177 	struct inpcb *inp;
178 	struct tcpcb *tp = 0;
179 	TCPDEBUG0;
180 
181 	soreference(so);
182 	inp = so->so_pcb;
183 	TCPDEBUG1();
184 	if (inp) {
185 		error = EISCONN;
186 		goto out;
187 	}
188 
189 	error = tcp_attach(so, ai);
190 	if (error)
191 		goto out;
192 
193 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
194 		so->so_linger = TCP_LINGERTIME;
195 	tp = sototcpcb(so);
196 out:
197 	sofree(so);		/* from ref above */
198 	TCPDEBUG2(PRU_ATTACH);
199 	lwkt_replymsg(&msg->lmsg, error);
200 }
201 
202 /*
203  * pru_detach() detaches the TCP protocol from the socket.
204  * If the protocol state is non-embryonic, then can't
205  * do this directly: have to initiate a pru_disconnect(),
206  * which may finish later; embryonic TCB's can just
207  * be discarded here.
208  */
209 static void
210 tcp_usr_detach(netmsg_t msg)
211 {
212 	struct socket *so = msg->base.nm_so;
213 	int error = 0;
214 	struct inpcb *inp;
215 	struct tcpcb *tp;
216 	TCPDEBUG0;
217 
218 	inp = so->so_pcb;
219 
220 	/*
221 	 * If the inp is already detached it may have been due to an async
222 	 * close.  Just return as if no error occured.
223 	 *
224 	 * It's possible for the tcpcb (tp) to disconnect from the inp due
225 	 * to tcp_drop()->tcp_close() being called.  This may occur *after*
226 	 * the detach message has been queued so we may find a NULL tp here.
227 	 */
228 	if (inp) {
229 		if ((tp = intotcpcb(inp)) != NULL) {
230 			TCPDEBUG1();
231 			tp = tcp_disconnect(tp);
232 			TCPDEBUG2(PRU_DETACH);
233 		}
234 	}
235 	lwkt_replymsg(&msg->lmsg, error);
236 }
237 
238 /*
239  * NOTE: ignore_error is non-zero for certain disconnection races
240  * which we want to silently allow, otherwise close() may return
241  * an unexpected error.
242  *
243  * NOTE: The variables (msg) and (tp) are assumed.
244  */
245 #define	COMMON_START(so, inp, ignore_error)			\
246 	TCPDEBUG0; 						\
247 								\
248 	inp = so->so_pcb; 					\
249 	do {							\
250 		 if (inp == NULL) {				\
251 			error = ignore_error ? 0 : EINVAL;	\
252 			tp = NULL;				\
253 			goto out;				\
254 		 }						\
255 		 tp = intotcpcb(inp);				\
256 		 TCPDEBUG1();					\
257 	} while(0)
258 
259 #define COMMON_END1(req, noreply)				\
260 	out: do {						\
261 		TCPDEBUG2(req);					\
262 		if (!(noreply))					\
263 			lwkt_replymsg(&msg->lmsg, error);	\
264 		return;						\
265 	} while(0)
266 
267 #define COMMON_END(req)		COMMON_END1((req), 0)
268 
269 /*
270  * Give the socket an address.
271  */
272 static void
273 tcp_usr_bind(netmsg_t msg)
274 {
275 	struct socket *so = msg->bind.base.nm_so;
276 	struct sockaddr *nam = msg->bind.nm_nam;
277 	struct thread *td = msg->bind.nm_td;
278 	int error = 0;
279 	struct inpcb *inp;
280 	struct tcpcb *tp;
281 	struct sockaddr_in *sinp;
282 
283 	COMMON_START(so, inp, 0);
284 
285 	/*
286 	 * Must check for multicast addresses and disallow binding
287 	 * to them.
288 	 */
289 	sinp = (struct sockaddr_in *)nam;
290 	if (sinp->sin_family == AF_INET &&
291 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
292 		error = EAFNOSUPPORT;
293 		goto out;
294 	}
295 	error = in_pcbbind(inp, nam, td);
296 	if (error)
297 		goto out;
298 	COMMON_END(PRU_BIND);
299 
300 }
301 
302 #ifdef INET6
303 
304 static void
305 tcp6_usr_bind(netmsg_t msg)
306 {
307 	struct socket *so = msg->bind.base.nm_so;
308 	struct sockaddr *nam = msg->bind.nm_nam;
309 	struct thread *td = msg->bind.nm_td;
310 	int error = 0;
311 	struct inpcb *inp;
312 	struct tcpcb *tp;
313 	struct sockaddr_in6 *sin6p;
314 
315 	COMMON_START(so, inp, 0);
316 
317 	/*
318 	 * Must check for multicast addresses and disallow binding
319 	 * to them.
320 	 */
321 	sin6p = (struct sockaddr_in6 *)nam;
322 	if (sin6p->sin6_family == AF_INET6 &&
323 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
324 		error = EAFNOSUPPORT;
325 		goto out;
326 	}
327 	inp->inp_vflag &= ~INP_IPV4;
328 	inp->inp_vflag |= INP_IPV6;
329 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
330 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
331 			inp->inp_vflag |= INP_IPV4;
332 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
333 			struct sockaddr_in sin;
334 
335 			in6_sin6_2_sin(&sin, sin6p);
336 			inp->inp_vflag |= INP_IPV4;
337 			inp->inp_vflag &= ~INP_IPV6;
338 			error = in_pcbbind(inp, (struct sockaddr *)&sin, td);
339 			goto out;
340 		}
341 	}
342 	error = in6_pcbbind(inp, nam, td);
343 	if (error)
344 		goto out;
345 	COMMON_END(PRU_BIND);
346 }
347 #endif /* INET6 */
348 
349 #ifdef SMP
350 
351 struct netmsg_inswildcard {
352 	struct netmsg_base	base;
353 	struct inpcb		*nm_inp;
354 };
355 
356 static void
357 in_pcbinswildcardhash_handler(netmsg_t msg)
358 {
359 	struct netmsg_inswildcard *nm = (struct netmsg_inswildcard *)msg;
360 	int cpu = mycpuid, nextcpu;
361 
362 	in_pcbinswildcardhash_oncpu(nm->nm_inp, &tcbinfo[cpu]);
363 
364 	nextcpu = cpu + 1;
365 	if (nextcpu < ncpus2)
366 		lwkt_forwardmsg(cpu_portfn(nextcpu), &nm->base.lmsg);
367 	else
368 		lwkt_replymsg(&nm->base.lmsg, 0);
369 }
370 
371 #endif
372 
373 /*
374  * Prepare to accept connections.
375  */
376 static void
377 tcp_usr_listen(netmsg_t msg)
378 {
379 	struct socket *so = msg->listen.base.nm_so;
380 	struct thread *td = msg->listen.nm_td;
381 	int error = 0;
382 	struct inpcb *inp;
383 	struct tcpcb *tp;
384 #ifdef SMP
385 	struct netmsg_inswildcard nm;
386 #endif
387 
388 	COMMON_START(so, inp, 0);
389 
390 	if (tp->t_flags & TF_LISTEN)
391 		goto out;
392 
393 	if (inp->inp_lport == 0) {
394 		error = in_pcbbind(inp, NULL, td);
395 		if (error)
396 			goto out;
397 	}
398 
399 	tp->t_state = TCPS_LISTEN;
400 	tp->t_flags |= TF_LISTEN;
401 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
402 
403 #ifdef SMP
404 	if (ncpus > 1) {
405 		/*
406 		 * We have to set the flag because we can't have other cpus
407 		 * messing with our inp's flags.
408 		 */
409 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
410 			("already on connhash\n"));
411 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
412 			("already on wildcardhash\n"));
413 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
414 			("already on MP wildcardhash\n"));
415 		inp->inp_flags |= INP_WILDCARD_MP;
416 
417 		KKASSERT(so->so_port == cpu_portfn(0));
418 		KKASSERT(&curthread->td_msgport == cpu_portfn(0));
419 		KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
420 
421 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
422 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
423 		nm.nm_inp = inp;
424 		lwkt_domsg(cpu_portfn(1), &nm.base.lmsg, 0);
425 	}
426 #endif
427 	in_pcbinswildcardhash(inp);
428 	COMMON_END(PRU_LISTEN);
429 }
430 
431 #ifdef INET6
432 
433 static void
434 tcp6_usr_listen(netmsg_t msg)
435 {
436 	struct socket *so = msg->listen.base.nm_so;
437 	struct thread *td = msg->listen.nm_td;
438 	int error = 0;
439 	struct inpcb *inp;
440 	struct tcpcb *tp;
441 #ifdef SMP
442 	struct netmsg_inswildcard nm;
443 #endif
444 
445 	COMMON_START(so, inp, 0);
446 
447 	if (tp->t_flags & TF_LISTEN)
448 		goto out;
449 
450 	if (inp->inp_lport == 0) {
451 		if (!(inp->inp_flags & IN6P_IPV6_V6ONLY))
452 			inp->inp_vflag |= INP_IPV4;
453 		else
454 			inp->inp_vflag &= ~INP_IPV4;
455 		error = in6_pcbbind(inp, NULL, td);
456 		if (error)
457 			goto out;
458 	}
459 
460 	tp->t_state = TCPS_LISTEN;
461 	tp->t_flags |= TF_LISTEN;
462 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
463 
464 #ifdef SMP
465 	if (ncpus > 1) {
466 		/*
467 		 * We have to set the flag because we can't have other cpus
468 		 * messing with our inp's flags.
469 		 */
470 		KASSERT(!(inp->inp_flags & INP_CONNECTED),
471 			("already on connhash\n"));
472 		KASSERT(!(inp->inp_flags & INP_WILDCARD),
473 			("already on wildcardhash\n"));
474 		KASSERT(!(inp->inp_flags & INP_WILDCARD_MP),
475 			("already on MP wildcardhash\n"));
476 		inp->inp_flags |= INP_WILDCARD_MP;
477 
478 		KKASSERT(so->so_port == cpu_portfn(0));
479 		KKASSERT(&curthread->td_msgport == cpu_portfn(0));
480 		KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
481 
482 		netmsg_init(&nm.base, NULL, &curthread->td_msgport,
483 			    MSGF_PRIORITY, in_pcbinswildcardhash_handler);
484 		nm.nm_inp = inp;
485 		lwkt_domsg(cpu_portfn(1), &nm.base.lmsg, 0);
486 	}
487 #endif
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 	lwkt_replymsg(&msg->lmsg, error);
537 }
538 
539 #ifdef INET6
540 
541 static void
542 tcp6_usr_connect(netmsg_t msg)
543 {
544 	struct socket *so = msg->connect.base.nm_so;
545 	struct sockaddr *nam = msg->connect.nm_nam;
546 	struct thread *td = msg->connect.nm_td;
547 	int error = 0;
548 	struct inpcb *inp;
549 	struct tcpcb *tp;
550 	struct sockaddr_in6 *sin6p;
551 
552 	COMMON_START(so, inp, 0);
553 
554 	/*
555 	 * Must disallow TCP ``connections'' to multicast addresses.
556 	 */
557 	sin6p = (struct sockaddr_in6 *)nam;
558 	if (sin6p->sin6_family == AF_INET6
559 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
560 		error = EAFNOSUPPORT;
561 		goto out;
562 	}
563 
564 	if (!prison_remote_ip(td, nam)) {
565 		error = EAFNOSUPPORT; /* IPv4 only jail */
566 		goto out;
567 	}
568 
569 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
570 		struct sockaddr_in *sinp;
571 
572 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
573 			error = EINVAL;
574 			goto out;
575 		}
576 		sinp = kmalloc(sizeof(*sinp), M_LWKTMSG, M_INTWAIT);
577 		in6_sin6_2_sin(sinp, sin6p);
578 		inp->inp_vflag |= INP_IPV4;
579 		inp->inp_vflag &= ~INP_IPV6;
580 		msg->connect.nm_nam = (struct sockaddr *)sinp;
581 		msg->connect.nm_reconnect |= NMSG_RECONNECT_NAMALLOC;
582 		tcp_connect(msg);
583 		/* msg is invalid now */
584 		return;
585 	}
586 	inp->inp_vflag &= ~INP_IPV4;
587 	inp->inp_vflag |= INP_IPV6;
588 	inp->inp_inc.inc_isipv6 = 1;
589 
590 	msg->connect.nm_reconnect |= NMSG_RECONNECT_FALLBACK;
591 	tcp6_connect(msg);
592 	/* msg is invalid now */
593 	return;
594 out:
595 	if (msg->connect.nm_m) {
596 		m_freem(msg->connect.nm_m);
597 		msg->connect.nm_m = NULL;
598 	}
599 	lwkt_replymsg(&msg->lmsg, error);
600 }
601 
602 #endif /* INET6 */
603 
604 /*
605  * Initiate disconnect from peer.
606  * If connection never passed embryonic stage, just drop;
607  * else if don't need to let data drain, then can just drop anyways,
608  * else have to begin TCP shutdown process: mark socket disconnecting,
609  * drain unread data, state switch to reflect user close, and
610  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
611  * when peer sends FIN and acks ours.
612  *
613  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
614  */
615 static void
616 tcp_usr_disconnect(netmsg_t msg)
617 {
618 	struct socket *so = msg->disconnect.base.nm_so;
619 	int error = 0;
620 	struct inpcb *inp;
621 	struct tcpcb *tp;
622 
623 	COMMON_START(so, inp, 1);
624 	tp = tcp_disconnect(tp);
625 	COMMON_END(PRU_DISCONNECT);
626 }
627 
628 /*
629  * Accept a connection.  Essentially all the work is
630  * done at higher levels; just return the address
631  * of the peer, storing through addr.
632  */
633 static void
634 tcp_usr_accept(netmsg_t msg)
635 {
636 	struct socket *so = msg->accept.base.nm_so;
637 	struct sockaddr **nam = msg->accept.nm_nam;
638 	int error = 0;
639 	struct inpcb *inp;
640 	struct tcpcb *tp = NULL;
641 	TCPDEBUG0;
642 
643 	inp = so->so_pcb;
644 	if (so->so_state & SS_ISDISCONNECTED) {
645 		error = ECONNABORTED;
646 		goto out;
647 	}
648 	if (inp == 0) {
649 		error = EINVAL;
650 		goto out;
651 	}
652 
653 	tp = intotcpcb(inp);
654 	TCPDEBUG1();
655 	in_setpeeraddr(so, nam);
656 	COMMON_END(PRU_ACCEPT);
657 }
658 
659 #ifdef INET6
660 static void
661 tcp6_usr_accept(netmsg_t msg)
662 {
663 	struct socket *so = msg->accept.base.nm_so;
664 	struct sockaddr **nam = msg->accept.nm_nam;
665 	int error = 0;
666 	struct inpcb *inp;
667 	struct tcpcb *tp = NULL;
668 	TCPDEBUG0;
669 
670 	inp = so->so_pcb;
671 
672 	if (so->so_state & SS_ISDISCONNECTED) {
673 		error = ECONNABORTED;
674 		goto out;
675 	}
676 	if (inp == 0) {
677 		error = EINVAL;
678 		goto out;
679 	}
680 	tp = intotcpcb(inp);
681 	TCPDEBUG1();
682 	in6_mapped_peeraddr(so, nam);
683 	COMMON_END(PRU_ACCEPT);
684 }
685 #endif /* INET6 */
686 /*
687  * Mark the connection as being incapable of further output.
688  */
689 static void
690 tcp_usr_shutdown(netmsg_t msg)
691 {
692 	struct socket *so = msg->shutdown.base.nm_so;
693 	int error = 0;
694 	struct inpcb *inp;
695 	struct tcpcb *tp;
696 
697 	COMMON_START(so, inp, 0);
698 	socantsendmore(so);
699 	tp = tcp_usrclosed(tp);
700 	if (tp)
701 		error = tcp_output(tp);
702 	COMMON_END(PRU_SHUTDOWN);
703 }
704 
705 /*
706  * After a receive, possibly send window update to peer.
707  */
708 static void
709 tcp_usr_rcvd(netmsg_t msg)
710 {
711 	struct socket *so = msg->rcvd.base.nm_so;
712 	int error = 0;
713 	struct inpcb *inp;
714 	struct tcpcb *tp;
715 
716 	COMMON_START(so, inp, 0);
717 	tcp_output(tp);
718 	COMMON_END(PRU_RCVD);
719 }
720 
721 /*
722  * Do a send by putting data in output queue and updating urgent
723  * marker if URG set.  Possibly send more data.  Unlike the other
724  * pru_*() routines, the mbuf chains are our responsibility.  We
725  * must either enqueue them or free them.  The other pru_* routines
726  * generally are caller-frees.
727  */
728 static void
729 tcp_usr_send(netmsg_t msg)
730 {
731 	struct socket *so = msg->send.base.nm_so;
732 	int flags = msg->send.nm_flags;
733 	struct mbuf *m = msg->send.nm_m;
734 	struct mbuf *control __debugvar = msg->send.nm_control;
735 	int error = 0;
736 	struct inpcb *inp;
737 	struct tcpcb *tp;
738 	TCPDEBUG0;
739 
740 	KKASSERT(control == NULL);
741 
742 	inp = so->so_pcb;
743 
744 	if (inp == NULL) {
745 		/*
746 		 * OOPS! we lost a race, the TCP session got reset after
747 		 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a
748 		 * network interrupt in the non-critical section of sosend().
749 		 */
750 		m_freem(m);
751 		error = ECONNRESET;	/* XXX EPIPE? */
752 		tp = NULL;
753 		TCPDEBUG1();
754 		goto out;
755 	}
756 	tp = intotcpcb(inp);
757 	TCPDEBUG1();
758 
759 	/*
760 	 * Don't let too much OOB data build up
761 	 */
762 	if (flags & PRUS_OOB) {
763 		if (ssb_space(&so->so_snd) < -512) {
764 			m_freem(m);
765 			error = ENOBUFS;
766 			goto out;
767 		}
768 	}
769 
770 	/*
771 	 * Pump the data into the socket.
772 	 */
773 	if (m)
774 		ssb_appendstream(&so->so_snd, m);
775 	if (flags & PRUS_OOB) {
776 		/*
777 		 * According to RFC961 (Assigned Protocols),
778 		 * the urgent pointer points to the last octet
779 		 * of urgent data.  We continue, however,
780 		 * to consider it to indicate the first octet
781 		 * of data past the urgent section.
782 		 * Otherwise, snd_up should be one lower.
783 		 */
784 		tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
785 		tp->t_flags |= TF_FORCE;
786 		error = tcp_output(tp);
787 		tp->t_flags &= ~TF_FORCE;
788 	} else {
789 		if (flags & PRUS_EOF) {
790 			/*
791 			 * Close the send side of the connection after
792 			 * the data is sent.
793 			 */
794 			socantsendmore(so);
795 			tp = tcp_usrclosed(tp);
796 		}
797 		if (tp != NULL) {
798 			if (flags & PRUS_MORETOCOME)
799 				tp->t_flags |= TF_MORETOCOME;
800 			error = tcp_output(tp);
801 			if (flags & PRUS_MORETOCOME)
802 				tp->t_flags &= ~TF_MORETOCOME;
803 		}
804 	}
805 	COMMON_END1((flags & PRUS_OOB) ? PRU_SENDOOB :
806 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND),
807 		   (flags & PRUS_NOREPLY));
808 }
809 
810 /*
811  * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
812  *	 will sofree() it when we return.
813  */
814 static void
815 tcp_usr_abort(netmsg_t msg)
816 {
817 	struct socket *so = msg->abort.base.nm_so;
818 	int error = 0;
819 	struct inpcb *inp;
820 	struct tcpcb *tp;
821 
822 	COMMON_START(so, inp, 1);
823 	tp = tcp_drop(tp, ECONNABORTED);
824 	COMMON_END(PRU_ABORT);
825 }
826 
827 /*
828  * Receive out-of-band data.
829  */
830 static void
831 tcp_usr_rcvoob(netmsg_t msg)
832 {
833 	struct socket *so = msg->rcvoob.base.nm_so;
834 	struct mbuf *m = msg->rcvoob.nm_m;
835 	int flags = msg->rcvoob.nm_flags;
836 	int error = 0;
837 	struct inpcb *inp;
838 	struct tcpcb *tp;
839 
840 	COMMON_START(so, inp, 0);
841 	if ((so->so_oobmark == 0 &&
842 	     (so->so_state & SS_RCVATMARK) == 0) ||
843 	    so->so_options & SO_OOBINLINE ||
844 	    tp->t_oobflags & TCPOOB_HADDATA) {
845 		error = EINVAL;
846 		goto out;
847 	}
848 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
849 		error = EWOULDBLOCK;
850 		goto out;
851 	}
852 	m->m_len = 1;
853 	*mtod(m, caddr_t) = tp->t_iobc;
854 	if ((flags & MSG_PEEK) == 0)
855 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
856 	COMMON_END(PRU_RCVOOB);
857 }
858 
859 /* xxx - should be const */
860 struct pr_usrreqs tcp_usrreqs = {
861 	.pru_abort = tcp_usr_abort,
862 	.pru_accept = tcp_usr_accept,
863 	.pru_attach = tcp_usr_attach,
864 	.pru_bind = tcp_usr_bind,
865 	.pru_connect = tcp_usr_connect,
866 	.pru_connect2 = pr_generic_notsupp,
867 	.pru_control = in_control_dispatch,
868 	.pru_detach = tcp_usr_detach,
869 	.pru_disconnect = tcp_usr_disconnect,
870 	.pru_listen = tcp_usr_listen,
871 	.pru_peeraddr = in_setpeeraddr_dispatch,
872 	.pru_rcvd = tcp_usr_rcvd,
873 	.pru_rcvoob = tcp_usr_rcvoob,
874 	.pru_send = tcp_usr_send,
875 	.pru_sense = pru_sense_null,
876 	.pru_shutdown = tcp_usr_shutdown,
877 	.pru_sockaddr = in_setsockaddr_dispatch,
878 	.pru_sosend = sosendtcp,
879 	.pru_soreceive = soreceive
880 };
881 
882 #ifdef INET6
883 struct pr_usrreqs tcp6_usrreqs = {
884 	.pru_abort = tcp_usr_abort,
885 	.pru_accept = tcp6_usr_accept,
886 	.pru_attach = tcp_usr_attach,
887 	.pru_bind = tcp6_usr_bind,
888 	.pru_connect = tcp6_usr_connect,
889 	.pru_connect2 = pr_generic_notsupp,
890 	.pru_control = in6_control_dispatch,
891 	.pru_detach = tcp_usr_detach,
892 	.pru_disconnect = tcp_usr_disconnect,
893 	.pru_listen = tcp6_usr_listen,
894 	.pru_peeraddr = in6_mapped_peeraddr_dispatch,
895 	.pru_rcvd = tcp_usr_rcvd,
896 	.pru_rcvoob = tcp_usr_rcvoob,
897 	.pru_send = tcp_usr_send,
898 	.pru_sense = pru_sense_null,
899 	.pru_shutdown = tcp_usr_shutdown,
900 	.pru_sockaddr = in6_mapped_sockaddr_dispatch,
901 	.pru_sosend = sosendtcp,
902 	.pru_soreceive = soreceive
903 };
904 #endif /* INET6 */
905 
906 static int
907 tcp_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf *m,
908 		  struct sockaddr_in *sin, struct sockaddr_in *if_sin)
909 {
910 	struct inpcb *inp = tp->t_inpcb, *oinp;
911 	struct socket *so = inp->inp_socket;
912 	struct route *ro = &inp->inp_route;
913 
914 	oinp = in_pcblookup_hash(&tcbinfo[mycpu->gd_cpuid],
915 				 sin->sin_addr, sin->sin_port,
916 				 (inp->inp_laddr.s_addr != INADDR_ANY ?
917 				  inp->inp_laddr : if_sin->sin_addr),
918 				inp->inp_lport, 0, NULL);
919 	if (oinp != NULL) {
920 		m_freem(m);
921 		return (EADDRINUSE);
922 	}
923 	if (inp->inp_laddr.s_addr == INADDR_ANY)
924 		inp->inp_laddr = if_sin->sin_addr;
925 	inp->inp_faddr = sin->sin_addr;
926 	inp->inp_fport = sin->sin_port;
927 	inp->inp_cpcbinfo = &tcbinfo[mycpu->gd_cpuid];
928 	in_pcbinsconnhash(inp);
929 
930 	/*
931 	 * We are now on the inpcb's owner CPU, if the cached route was
932 	 * freed because the rtentry's owner CPU is not the current CPU
933 	 * (e.g. in tcp_connect()), then we try to reallocate it here with
934 	 * the hope that a rtentry may be cloned from a RTF_PRCLONING
935 	 * rtentry.
936 	 */
937 	if (!(inp->inp_socket->so_options & SO_DONTROUTE) && /*XXX*/
938 	    ro->ro_rt == NULL) {
939 		bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
940 		ro->ro_dst.sa_family = AF_INET;
941 		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
942 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr =
943 			sin->sin_addr;
944 		rtalloc(ro);
945 	}
946 
947 	/*
948 	 * Now that no more errors can occur, change the protocol processing
949 	 * port to the current thread (which is the correct thread).
950 	 *
951 	 * Create TCP timer message now; we are on the tcpcb's owner
952 	 * CPU/thread.
953 	 */
954 	tcp_create_timermsg(tp, &curthread->td_msgport);
955 
956 	/*
957 	 * Compute window scaling to request.  Use a larger scaling then
958 	 * needed for the initial receive buffer in case the receive buffer
959 	 * gets expanded.
960 	 */
961 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
962 		tp->request_r_scale = TCP_MIN_WINSHIFT;
963 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
964 	       (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat
965 	) {
966 		tp->request_r_scale++;
967 	}
968 
969 	soisconnecting(so);
970 	tcpstat.tcps_connattempt++;
971 	tp->t_state = TCPS_SYN_SENT;
972 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
973 	tp->iss = tcp_new_isn(tp);
974 	tcp_sendseqinit(tp);
975 	if (m) {
976 		ssb_appendstream(&so->so_snd, m);
977 		m = NULL;
978 		if (flags & PRUS_OOB)
979 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
980 	}
981 
982 	/*
983 	 * Close the send side of the connection after
984 	 * the data is sent if flagged.
985 	 */
986 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
987 		socantsendmore(so);
988 		tp = tcp_usrclosed(tp);
989 	}
990 	return (tcp_output(tp));
991 }
992 
993 /*
994  * Common subroutine to open a TCP connection to remote host specified
995  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
996  * port number if needed.  Call in_pcbladdr to do the routing and to choose
997  * a local host address (interface).
998  * Initialize connection parameters and enter SYN-SENT state.
999  */
1000 static void
1001 tcp_connect(netmsg_t msg)
1002 {
1003 	struct socket *so = msg->connect.base.nm_so;
1004 	struct sockaddr *nam = msg->connect.nm_nam;
1005 	struct thread *td = msg->connect.nm_td;
1006 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
1007 	struct sockaddr_in *if_sin;
1008 	struct inpcb *inp;
1009 	struct tcpcb *tp;
1010 	int error, calc_laddr = 1;
1011 #ifdef SMP
1012 	lwkt_port_t port;
1013 #endif
1014 
1015 	COMMON_START(so, inp, 0);
1016 
1017 	/*
1018 	 * Reconnect our pcb if we have to
1019 	 */
1020 	if (msg->connect.nm_reconnect & NMSG_RECONNECT_RECONNECT) {
1021 		msg->connect.nm_reconnect &= ~NMSG_RECONNECT_RECONNECT;
1022 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1023 	}
1024 
1025 	/*
1026 	 * Bind if we have to
1027 	 */
1028 	if (inp->inp_lport == 0) {
1029 		if (tcp_lport_extension) {
1030 			KKASSERT(inp->inp_laddr.s_addr == INADDR_ANY);
1031 
1032 			error = in_pcbladdr(inp, nam, &if_sin, td);
1033 			if (error)
1034 				goto out;
1035 			inp->inp_laddr.s_addr = if_sin->sin_addr.s_addr;
1036 
1037 			error = in_pcbconn_bind(inp, nam, td);
1038 			if (error)
1039 				goto out;
1040 
1041 			calc_laddr = 0;
1042 		} else {
1043 			error = in_pcbbind(inp, NULL, td);
1044 			if (error)
1045 				goto out;
1046 		}
1047 	}
1048 
1049 	if (calc_laddr) {
1050 		/*
1051 		 * Calculate the correct protocol processing thread.  The
1052 		 * connect operation must run there.  Set the forwarding
1053 		 * port before we forward the message or it will get bounced
1054 		 * right back to us.
1055 		 */
1056 		error = in_pcbladdr(inp, nam, &if_sin, td);
1057 		if (error)
1058 			goto out;
1059 	}
1060 	KKASSERT(inp->inp_socket == so);
1061 
1062 #ifdef SMP
1063 	port = tcp_addrport(sin->sin_addr.s_addr, sin->sin_port,
1064 			    (inp->inp_laddr.s_addr ?
1065 			     inp->inp_laddr.s_addr : if_sin->sin_addr.s_addr),
1066 			    inp->inp_lport);
1067 
1068 	if (port != &curthread->td_msgport) {
1069 		struct route *ro = &inp->inp_route;
1070 
1071 		/*
1072 		 * in_pcbladdr() may have allocated a route entry for us
1073 		 * on the current CPU, but we need a route entry on the
1074 		 * inpcb's owner CPU, so free it here.
1075 		 */
1076 		if (ro->ro_rt != NULL)
1077 			RTFREE(ro->ro_rt);
1078 		bzero(ro, sizeof(*ro));
1079 
1080 		/*
1081 		 * We are moving the protocol processing port the socket
1082 		 * is on, we have to unlink here and re-link on the
1083 		 * target cpu.
1084 		 */
1085 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1086 		sosetport(so, port);
1087 		msg->connect.nm_reconnect |= NMSG_RECONNECT_RECONNECT;
1088 		msg->connect.base.nm_dispatch = tcp_connect;
1089 
1090 		lwkt_forwardmsg(port, &msg->connect.base.lmsg);
1091 		/* msg invalid now */
1092 		return;
1093 	}
1094 #else
1095 	KKASSERT(so->so_port == &curthread->td_msgport);
1096 #endif
1097 	error = tcp_connect_oncpu(tp, msg->connect.nm_flags,
1098 				  msg->connect.nm_m, sin, if_sin);
1099 	msg->connect.nm_m = NULL;
1100 out:
1101 	if (msg->connect.nm_m) {
1102 		m_freem(msg->connect.nm_m);
1103 		msg->connect.nm_m = NULL;
1104 	}
1105 	if (msg->connect.nm_reconnect & NMSG_RECONNECT_NAMALLOC) {
1106 		kfree(msg->connect.nm_nam, M_LWKTMSG);
1107 		msg->connect.nm_nam = NULL;
1108 	}
1109 	lwkt_replymsg(&msg->connect.base.lmsg, error);
1110 	/* msg invalid now */
1111 }
1112 
1113 #ifdef INET6
1114 
1115 static void
1116 tcp6_connect(netmsg_t msg)
1117 {
1118 	struct tcpcb *tp;
1119 	struct socket *so = msg->connect.base.nm_so;
1120 	struct sockaddr *nam = msg->connect.nm_nam;
1121 	struct thread *td = msg->connect.nm_td;
1122 	struct inpcb *inp;
1123 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1124 	struct in6_addr *addr6;
1125 #ifdef SMP
1126 	lwkt_port_t port;
1127 #endif
1128 	int error;
1129 
1130 	COMMON_START(so, inp, 0);
1131 
1132 	/*
1133 	 * Reconnect our pcb if we have to
1134 	 */
1135 	if (msg->connect.nm_reconnect & NMSG_RECONNECT_RECONNECT) {
1136 		msg->connect.nm_reconnect &= ~NMSG_RECONNECT_RECONNECT;
1137 		in_pcblink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1138 	}
1139 
1140 	/*
1141 	 * Bind if we have to
1142 	 */
1143 	if (inp->inp_lport == 0) {
1144 		error = in6_pcbbind(inp, NULL, td);
1145 		if (error)
1146 			goto out;
1147 	}
1148 
1149 	/*
1150 	 * Cannot simply call in_pcbconnect, because there might be an
1151 	 * earlier incarnation of this same connection still in
1152 	 * TIME_WAIT state, creating an ADDRINUSE error.
1153 	 */
1154 	error = in6_pcbladdr(inp, nam, &addr6, td);
1155 	if (error)
1156 		goto out;
1157 
1158 #ifdef SMP
1159 	port = tcp6_addrport();	/* XXX hack for now, always cpu0 */
1160 
1161 	if (port != &curthread->td_msgport) {
1162 		struct route *ro = &inp->inp_route;
1163 
1164 		/*
1165 		 * in_pcbladdr() may have allocated a route entry for us
1166 		 * on the current CPU, but we need a route entry on the
1167 		 * inpcb's owner CPU, so free it here.
1168 		 */
1169 		if (ro->ro_rt != NULL)
1170 			RTFREE(ro->ro_rt);
1171 		bzero(ro, sizeof(*ro));
1172 
1173 		in_pcbunlink(so->so_pcb, &tcbinfo[mycpu->gd_cpuid]);
1174 		sosetport(so, port);
1175 		msg->connect.nm_reconnect |= NMSG_RECONNECT_RECONNECT;
1176 		msg->connect.base.nm_dispatch = tcp6_connect;
1177 
1178 		lwkt_forwardmsg(port, &msg->connect.base.lmsg);
1179 		/* msg invalid now */
1180 		return;
1181 	}
1182 #endif
1183 	error = tcp6_connect_oncpu(tp, msg->connect.nm_flags,
1184 				   &msg->connect.nm_m, sin6, addr6);
1185 	/* nm_m may still be intact */
1186 out:
1187 	if (error && (msg->connect.nm_reconnect & NMSG_RECONNECT_FALLBACK)) {
1188 		tcp_connect(msg);
1189 		/* msg invalid now */
1190 	} else {
1191 		if (msg->connect.nm_m) {
1192 			m_freem(msg->connect.nm_m);
1193 			msg->connect.nm_m = NULL;
1194 		}
1195 		if (msg->connect.nm_reconnect & NMSG_RECONNECT_NAMALLOC) {
1196 			kfree(msg->connect.nm_nam, M_LWKTMSG);
1197 			msg->connect.nm_nam = NULL;
1198 		}
1199 		lwkt_replymsg(&msg->connect.base.lmsg, error);
1200 		/* msg invalid now */
1201 	}
1202 }
1203 
1204 static int
1205 tcp6_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf **mp,
1206 		   struct sockaddr_in6 *sin6, struct in6_addr *addr6)
1207 {
1208 	struct mbuf *m = *mp;
1209 	struct inpcb *inp = tp->t_inpcb;
1210 	struct socket *so = inp->inp_socket;
1211 	struct inpcb *oinp;
1212 
1213 	/*
1214 	 * Cannot simply call in_pcbconnect, because there might be an
1215 	 * earlier incarnation of this same connection still in
1216 	 * TIME_WAIT state, creating an ADDRINUSE error.
1217 	 */
1218 	oinp = in6_pcblookup_hash(inp->inp_cpcbinfo,
1219 				  &sin6->sin6_addr, sin6->sin6_port,
1220 				  (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ?
1221 				      addr6 : &inp->in6p_laddr),
1222 				  inp->inp_lport,  0, NULL);
1223 	if (oinp)
1224 		return (EADDRINUSE);
1225 
1226 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1227 		inp->in6p_laddr = *addr6;
1228 	inp->in6p_faddr = sin6->sin6_addr;
1229 	inp->inp_fport = sin6->sin6_port;
1230 	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != 0)
1231 		inp->in6p_flowinfo = sin6->sin6_flowinfo;
1232 	in_pcbinsconnhash(inp);
1233 
1234 	/*
1235 	 * Now that no more errors can occur, change the protocol processing
1236 	 * port to the current thread (which is the correct thread).
1237 	 *
1238 	 * Create TCP timer message now; we are on the tcpcb's owner
1239 	 * CPU/thread.
1240 	 */
1241 	tcp_create_timermsg(tp, &curthread->td_msgport);
1242 
1243 	/* Compute window scaling to request.  */
1244 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1245 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1246 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1247 	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat) {
1248 		tp->request_r_scale++;
1249 	}
1250 
1251 	soisconnecting(so);
1252 	tcpstat.tcps_connattempt++;
1253 	tp->t_state = TCPS_SYN_SENT;
1254 	tcp_callout_reset(tp, tp->tt_keep, tp->t_keepinit, tcp_timer_keep);
1255 	tp->iss = tcp_new_isn(tp);
1256 	tcp_sendseqinit(tp);
1257 	if (m) {
1258 		ssb_appendstream(&so->so_snd, m);
1259 		*mp = NULL;
1260 		if (flags & PRUS_OOB)
1261 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1262 	}
1263 
1264 	/*
1265 	 * Close the send side of the connection after
1266 	 * the data is sent if flagged.
1267 	 */
1268 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1269 		socantsendmore(so);
1270 		tp = tcp_usrclosed(tp);
1271 	}
1272 	return (tcp_output(tp));
1273 }
1274 
1275 #endif /* INET6 */
1276 
1277 /*
1278  * The new sockopt interface makes it possible for us to block in the
1279  * copyin/out step (if we take a page fault).  Taking a page fault while
1280  * in a critical section is probably a Bad Thing.  (Since sockets and pcbs
1281  * both now use TSM, there probably isn't any need for this function to
1282  * run in a critical section any more.  This needs more examination.)
1283  */
1284 void
1285 tcp_ctloutput(netmsg_t msg)
1286 {
1287 	struct socket *so = msg->base.nm_so;
1288 	struct sockopt *sopt = msg->ctloutput.nm_sopt;
1289 	int	error, opt, optval, opthz;
1290 	struct	inpcb *inp;
1291 	struct	tcpcb *tp;
1292 
1293 	error = 0;
1294 	inp = so->so_pcb;
1295 	if (inp == NULL) {
1296 		error = ECONNRESET;
1297 		goto done;
1298 	}
1299 
1300 	if (sopt->sopt_level != IPPROTO_TCP) {
1301 #ifdef INET6
1302 		if (INP_CHECK_SOCKAF(so, AF_INET6))
1303 			ip6_ctloutput_dispatch(msg);
1304 		else
1305 #endif /* INET6 */
1306 		ip_ctloutput(msg);
1307 		/* msg invalid now */
1308 		return;
1309 	}
1310 	tp = intotcpcb(inp);
1311 
1312 	switch (sopt->sopt_dir) {
1313 	case SOPT_SET:
1314 		error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1315 				      sizeof optval);
1316 		if (error)
1317 			break;
1318 		switch (sopt->sopt_name) {
1319 		case TCP_FASTKEEP:
1320 			if (optval > 0) {
1321 				if ((tp->t_flags & TF_FASTKEEP) == 0) {
1322 					tp->t_flags |= TF_FASTKEEP;
1323 					tcp_timer_keep_activity(tp, 0);
1324 				}
1325 			} else {
1326 				tp->t_flags &= ~TF_FASTKEEP;
1327 			}
1328 			break;
1329 #ifdef TCP_SIGNATURE
1330 		case TCP_SIGNATURE_ENABLE:
1331 			if (optval > 0)
1332 				tp->t_flags |= TF_SIGNATURE;
1333 			else
1334 				tp->t_flags &= ~TF_SIGNATURE;
1335 			break;
1336 #endif /* TCP_SIGNATURE */
1337 		case TCP_NODELAY:
1338 		case TCP_NOOPT:
1339 			switch (sopt->sopt_name) {
1340 			case TCP_NODELAY:
1341 				opt = TF_NODELAY;
1342 				break;
1343 			case TCP_NOOPT:
1344 				opt = TF_NOOPT;
1345 				break;
1346 			default:
1347 				opt = 0; /* dead code to fool gcc */
1348 				break;
1349 			}
1350 
1351 			if (optval)
1352 				tp->t_flags |= opt;
1353 			else
1354 				tp->t_flags &= ~opt;
1355 			break;
1356 
1357 		case TCP_NOPUSH:
1358 			if (optval)
1359 				tp->t_flags |= TF_NOPUSH;
1360 			else {
1361 				tp->t_flags &= ~TF_NOPUSH;
1362 				error = tcp_output(tp);
1363 			}
1364 			break;
1365 
1366 		case TCP_MAXSEG:
1367 			/*
1368 			 * Must be between 0 and maxseg.  If the requested
1369 			 * maxseg is too small to satisfy the desired minmss,
1370 			 * pump it up (silently so sysctl modifications of
1371 			 * minmss do not create unexpected program failures).
1372 			 * Handle degenerate cases.
1373 			 */
1374 			if (optval > 0 && optval <= tp->t_maxseg) {
1375 				if (optval + 40 < tcp_minmss) {
1376 					optval = tcp_minmss - 40;
1377 					if (optval < 0)
1378 						optval = 1;
1379 				}
1380 				tp->t_maxseg = optval;
1381 			} else {
1382 				error = EINVAL;
1383 			}
1384 			break;
1385 
1386 		case TCP_KEEPINIT:
1387 			opthz = ((int64_t)optval * hz) / 1000;
1388 			if (opthz >= 1)
1389 				tp->t_keepinit = opthz;
1390 			else
1391 				error = EINVAL;
1392 			break;
1393 
1394 		case TCP_KEEPIDLE:
1395 			opthz = ((int64_t)optval * hz) / 1000;
1396 			if (opthz >= 1)
1397 				tp->t_keepidle = opthz;
1398 			else
1399 				error = EINVAL;
1400 			break;
1401 
1402 		case TCP_KEEPINTVL:
1403 			opthz = ((int64_t)optval * hz) / 1000;
1404 			if (opthz >= 1) {
1405 				tp->t_keepintvl = opthz;
1406 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1407 			} else {
1408 				error = EINVAL;
1409 			}
1410 			break;
1411 
1412 		case TCP_KEEPCNT:
1413 			if (optval > 0) {
1414 				tp->t_keepcnt = optval;
1415 				tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
1416 			} else {
1417 				error = EINVAL;
1418 			}
1419 			break;
1420 
1421 		default:
1422 			error = ENOPROTOOPT;
1423 			break;
1424 		}
1425 		break;
1426 
1427 	case SOPT_GET:
1428 		switch (sopt->sopt_name) {
1429 #ifdef TCP_SIGNATURE
1430 		case TCP_SIGNATURE_ENABLE:
1431 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1432 			break;
1433 #endif /* TCP_SIGNATURE */
1434 		case TCP_NODELAY:
1435 			optval = tp->t_flags & TF_NODELAY;
1436 			break;
1437 		case TCP_MAXSEG:
1438 			optval = tp->t_maxseg;
1439 			break;
1440 		case TCP_NOOPT:
1441 			optval = tp->t_flags & TF_NOOPT;
1442 			break;
1443 		case TCP_NOPUSH:
1444 			optval = tp->t_flags & TF_NOPUSH;
1445 			break;
1446 		case TCP_KEEPINIT:
1447 			optval = ((int64_t)tp->t_keepinit * 1000) / hz;
1448 			break;
1449 		case TCP_KEEPIDLE:
1450 			optval = ((int64_t)tp->t_keepidle * 1000) / hz;
1451 			break;
1452 		case TCP_KEEPINTVL:
1453 			optval = ((int64_t)tp->t_keepintvl * 1000) / hz;
1454 			break;
1455 		case TCP_KEEPCNT:
1456 			optval = tp->t_keepcnt;
1457 			break;
1458 		default:
1459 			error = ENOPROTOOPT;
1460 			break;
1461 		}
1462 		if (error == 0)
1463 			soopt_from_kbuf(sopt, &optval, sizeof optval);
1464 		break;
1465 	}
1466 done:
1467 	lwkt_replymsg(&msg->lmsg, error);
1468 }
1469 
1470 /*
1471  * tcp_sendspace and tcp_recvspace are the default send and receive window
1472  * sizes, respectively.  These are obsolescent (this information should
1473  * be set by the route).
1474  *
1475  * Use a default that does not require tcp window scaling to be turned
1476  * on.  Individual programs or the administrator can increase the default.
1477  */
1478 u_long	tcp_sendspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1479 SYSCTL_INT(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1480     &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1481 u_long	tcp_recvspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1482 SYSCTL_INT(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1483     &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1484 
1485 /*
1486  * Attach TCP protocol to socket, allocating internet protocol control
1487  * block, tcp control block, bufer space, and entering LISTEN state
1488  * if to accept connections.
1489  */
1490 static int
1491 tcp_attach(struct socket *so, struct pru_attach_info *ai)
1492 {
1493 	struct tcpcb *tp;
1494 	struct inpcb *inp;
1495 	int error;
1496 	int cpu;
1497 #ifdef INET6
1498 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
1499 #endif
1500 
1501 	if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
1502 		lwkt_gettoken(&so->so_rcv.ssb_token);
1503 		error = soreserve(so, tcp_sendspace, tcp_recvspace,
1504 				  ai->sb_rlimit);
1505 		lwkt_reltoken(&so->so_rcv.ssb_token);
1506 		if (error)
1507 			return (error);
1508 	}
1509 	atomic_set_int(&so->so_rcv.ssb_flags, SSB_AUTOSIZE);
1510 	atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOSIZE);
1511 	cpu = mycpu->gd_cpuid;
1512 
1513 	/*
1514 	 * Set the default port for protocol processing. This will likely
1515 	 * change when we connect.
1516 	 */
1517 	error = in_pcballoc(so, &tcbinfo[cpu]);
1518 	if (error)
1519 		return (error);
1520 	inp = so->so_pcb;
1521 #ifdef INET6
1522 	if (isipv6) {
1523 		inp->inp_vflag |= INP_IPV6;
1524 		inp->in6p_hops = -1;	/* use kernel default */
1525 	}
1526 	else
1527 #endif
1528 	inp->inp_vflag |= INP_IPV4;
1529 	tp = tcp_newtcpcb(inp);
1530 	if (tp == NULL) {
1531 		/*
1532 		 * Make sure the socket is destroyed by the pcbdetach.
1533 		 */
1534 		soreference(so);
1535 #ifdef INET6
1536 		if (isipv6)
1537 			in6_pcbdetach(inp);
1538 		else
1539 #endif
1540 		in_pcbdetach(inp);
1541 		sofree(so);	/* from ref above */
1542 		return (ENOBUFS);
1543 	}
1544 	tp->t_state = TCPS_CLOSED;
1545 	return (0);
1546 }
1547 
1548 /*
1549  * Initiate (or continue) disconnect.
1550  * If embryonic state, just send reset (once).
1551  * If in ``let data drain'' option and linger null, just drop.
1552  * Otherwise (hard), mark socket disconnecting and drop
1553  * current input data; switch states based on user close, and
1554  * send segment to peer (with FIN).
1555  */
1556 static struct tcpcb *
1557 tcp_disconnect(struct tcpcb *tp)
1558 {
1559 	struct socket *so = tp->t_inpcb->inp_socket;
1560 
1561 	if (tp->t_state < TCPS_ESTABLISHED) {
1562 		tp = tcp_close(tp);
1563 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1564 		tp = tcp_drop(tp, 0);
1565 	} else {
1566 		lwkt_gettoken(&so->so_rcv.ssb_token);
1567 		soisdisconnecting(so);
1568 		sbflush(&so->so_rcv.sb);
1569 		tp = tcp_usrclosed(tp);
1570 		if (tp)
1571 			tcp_output(tp);
1572 		lwkt_reltoken(&so->so_rcv.ssb_token);
1573 	}
1574 	return (tp);
1575 }
1576 
1577 /*
1578  * User issued close, and wish to trail through shutdown states:
1579  * if never received SYN, just forget it.  If got a SYN from peer,
1580  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1581  * If already got a FIN from peer, then almost done; go to LAST_ACK
1582  * state.  In all other cases, have already sent FIN to peer (e.g.
1583  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1584  * for peer to send FIN or not respond to keep-alives, etc.
1585  * We can let the user exit from the close as soon as the FIN is acked.
1586  */
1587 static struct tcpcb *
1588 tcp_usrclosed(struct tcpcb *tp)
1589 {
1590 
1591 	switch (tp->t_state) {
1592 
1593 	case TCPS_CLOSED:
1594 	case TCPS_LISTEN:
1595 		tp->t_state = TCPS_CLOSED;
1596 		tp = tcp_close(tp);
1597 		break;
1598 
1599 	case TCPS_SYN_SENT:
1600 	case TCPS_SYN_RECEIVED:
1601 		tp->t_flags |= TF_NEEDFIN;
1602 		break;
1603 
1604 	case TCPS_ESTABLISHED:
1605 		tp->t_state = TCPS_FIN_WAIT_1;
1606 		break;
1607 
1608 	case TCPS_CLOSE_WAIT:
1609 		tp->t_state = TCPS_LAST_ACK;
1610 		break;
1611 	}
1612 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1613 		soisdisconnected(tp->t_inpcb->inp_socket);
1614 		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
1615 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1616 			tcp_callout_reset(tp, tp->tt_2msl, tp->t_maxidle,
1617 			    tcp_timer_2msl);
1618 		}
1619 	}
1620 	return (tp);
1621 }
1622