xref: /dflybsd-src/sys/netinet/tcp_usrreq.c (revision 93bffecadc0caefc46f12b736eab0e62c2b6f42e)
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  * $DragonFly: src/sys/netinet/tcp_usrreq.c,v 1.51 2008/09/29 20:52:23 dillon Exp $
69  */
70 
71 #include "opt_ipsec.h"
72 #include "opt_inet.h"
73 #include "opt_inet6.h"
74 #include "opt_tcpdebug.h"
75 
76 #include <sys/param.h>
77 #include <sys/systm.h>
78 #include <sys/kernel.h>
79 #include <sys/malloc.h>
80 #include <sys/sysctl.h>
81 #include <sys/globaldata.h>
82 #include <sys/thread.h>
83 
84 #include <sys/mbuf.h>
85 #ifdef INET6
86 #include <sys/domain.h>
87 #endif /* INET6 */
88 #include <sys/socket.h>
89 #include <sys/socketvar.h>
90 #include <sys/protosw.h>
91 
92 #include <sys/thread2.h>
93 #include <sys/msgport2.h>
94 #include <sys/socketvar2.h>
95 
96 #include <net/if.h>
97 #include <net/netisr.h>
98 #include <net/route.h>
99 
100 #include <net/netmsg2.h>
101 
102 #include <netinet/in.h>
103 #include <netinet/in_systm.h>
104 #ifdef INET6
105 #include <netinet/ip6.h>
106 #endif
107 #include <netinet/in_pcb.h>
108 #ifdef INET6
109 #include <netinet6/in6_pcb.h>
110 #endif
111 #include <netinet/in_var.h>
112 #include <netinet/ip_var.h>
113 #ifdef INET6
114 #include <netinet6/ip6_var.h>
115 #include <netinet6/tcp6_var.h>
116 #endif
117 #include <netinet/tcp.h>
118 #include <netinet/tcp_fsm.h>
119 #include <netinet/tcp_seq.h>
120 #include <netinet/tcp_timer.h>
121 #include <netinet/tcp_timer2.h>
122 #include <netinet/tcp_var.h>
123 #include <netinet/tcpip.h>
124 #ifdef TCPDEBUG
125 #include <netinet/tcp_debug.h>
126 #endif
127 
128 #ifdef IPSEC
129 #include <netinet6/ipsec.h>
130 #endif /*IPSEC*/
131 
132 /*
133  * TCP protocol interface to socket abstraction.
134  */
135 extern	char *tcpstates[];	/* XXX ??? */
136 
137 static int	tcp_attach (struct socket *, struct pru_attach_info *);
138 static int	tcp_connect (struct tcpcb *, int flags, struct mbuf *m,
139 				struct sockaddr *, struct thread *);
140 #ifdef INET6
141 static int	tcp6_connect (struct tcpcb *, int flags, struct mbuf *m,
142 				struct sockaddr *, struct thread *);
143 static int	tcp6_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf *m,
144 				struct sockaddr_in6 *sin6,
145 				struct in6_addr *addr6);
146 #endif /* INET6 */
147 static struct tcpcb *
148 		tcp_disconnect (struct tcpcb *);
149 static struct tcpcb *
150 		tcp_usrclosed (struct tcpcb *);
151 
152 #ifdef TCPDEBUG
153 #define	TCPDEBUG0	int ostate = 0
154 #define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
155 #define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
156 				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
157 #else
158 #define	TCPDEBUG0
159 #define	TCPDEBUG1()
160 #define	TCPDEBUG2(req)
161 #endif
162 
163 /*
164  * TCP attaches to socket via pru_attach(), reserving space,
165  * and an internet control block.
166  */
167 static int
168 tcp_usr_attach(struct socket *so, int proto, struct pru_attach_info *ai)
169 {
170 	int error;
171 	struct inpcb *inp;
172 	struct tcpcb *tp = 0;
173 	TCPDEBUG0;
174 
175 	soreference(so);
176 	inp = so->so_pcb;
177 	TCPDEBUG1();
178 	if (inp) {
179 		error = EISCONN;
180 		goto out;
181 	}
182 
183 	error = tcp_attach(so, ai);
184 	if (error)
185 		goto out;
186 
187 	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
188 		so->so_linger = TCP_LINGERTIME;
189 	tp = sototcpcb(so);
190 out:
191 	sofree(so);		/* from ref above */
192 	TCPDEBUG2(PRU_ATTACH);
193 	return error;
194 }
195 
196 /*
197  * pru_detach() detaches the TCP protocol from the socket.
198  * If the protocol state is non-embryonic, then can't
199  * do this directly: have to initiate a pru_disconnect(),
200  * which may finish later; embryonic TCB's can just
201  * be discarded here.
202  */
203 static int
204 tcp_usr_detach(struct socket *so)
205 {
206 	int error = 0;
207 	struct inpcb *inp;
208 	struct tcpcb *tp;
209 	TCPDEBUG0;
210 
211 	inp = so->so_pcb;
212 
213 	/*
214 	 * If the inp is already detached it may have been due to an async
215 	 * close.  Just return as if no error occured.
216 	 */
217 	if (inp == NULL)
218 		return 0;
219 
220 	/*
221 	 * It's possible for the tcpcb (tp) to disconnect from the inp due
222 	 * to tcp_drop()->tcp_close() being called.  This may occur *after*
223 	 * the detach message has been queued so we may find a NULL tp here.
224 	 */
225 	if ((tp = intotcpcb(inp)) != NULL) {
226 		TCPDEBUG1();
227 		tp = tcp_disconnect(tp);
228 		TCPDEBUG2(PRU_DETACH);
229 	}
230 	return error;
231 }
232 
233 /*
234  * Note: ignore_error is non-zero for certain disconnection races
235  * which we want to silently allow, otherwise close() may return
236  * an unexpected error.
237  */
238 #define	COMMON_START(so, inp, ignore_error)			\
239 	TCPDEBUG0; 		\
240 				\
241 	inp = so->so_pcb; 	\
242 	do {			\
243 		 if (inp == NULL) {				\
244 			 return (ignore_error ? 0 : EINVAL);	\
245 		 }						\
246 		 tp = intotcpcb(inp);				\
247 		 TCPDEBUG1();					\
248 	} while(0)
249 
250 #define COMMON_END(req)	out: TCPDEBUG2(req); return error; goto out
251 
252 /*
253  * Give the socket an address.
254  */
255 static int
256 tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
257 {
258 	int error = 0;
259 	struct inpcb *inp;
260 	struct tcpcb *tp;
261 	struct sockaddr_in *sinp;
262 
263 	COMMON_START(so, inp, 0);
264 
265 	/*
266 	 * Must check for multicast addresses and disallow binding
267 	 * to them.
268 	 */
269 	sinp = (struct sockaddr_in *)nam;
270 	if (sinp->sin_family == AF_INET &&
271 	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
272 		error = EAFNOSUPPORT;
273 		goto out;
274 	}
275 	error = in_pcbbind(inp, nam, td);
276 	if (error)
277 		goto out;
278 	COMMON_END(PRU_BIND);
279 
280 }
281 
282 #ifdef INET6
283 static int
284 tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
285 {
286 	int error = 0;
287 	struct inpcb *inp;
288 	struct tcpcb *tp;
289 	struct sockaddr_in6 *sin6p;
290 
291 	COMMON_START(so, inp, 0);
292 
293 	/*
294 	 * Must check for multicast addresses and disallow binding
295 	 * to them.
296 	 */
297 	sin6p = (struct sockaddr_in6 *)nam;
298 	if (sin6p->sin6_family == AF_INET6 &&
299 	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
300 		error = EAFNOSUPPORT;
301 		goto out;
302 	}
303 	inp->inp_vflag &= ~INP_IPV4;
304 	inp->inp_vflag |= INP_IPV6;
305 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
306 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
307 			inp->inp_vflag |= INP_IPV4;
308 		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
309 			struct sockaddr_in sin;
310 
311 			in6_sin6_2_sin(&sin, sin6p);
312 			inp->inp_vflag |= INP_IPV4;
313 			inp->inp_vflag &= ~INP_IPV6;
314 			error = in_pcbbind(inp, (struct sockaddr *)&sin, td);
315 			goto out;
316 		}
317 	}
318 	error = in6_pcbbind(inp, nam, td);
319 	if (error)
320 		goto out;
321 	COMMON_END(PRU_BIND);
322 }
323 #endif /* INET6 */
324 
325 #ifdef SMP
326 struct netmsg_inswildcard {
327 	struct netmsg		nm_netmsg;
328 	struct inpcb		*nm_inp;
329 	struct inpcbinfo	*nm_pcbinfo;
330 };
331 
332 static void
333 in_pcbinswildcardhash_handler(struct netmsg *msg0)
334 {
335 	struct netmsg_inswildcard *msg = (struct netmsg_inswildcard *)msg0;
336 
337 	in_pcbinswildcardhash_oncpu(msg->nm_inp, msg->nm_pcbinfo);
338 	lwkt_replymsg(&msg->nm_netmsg.nm_lmsg, 0);
339 }
340 #endif
341 
342 /*
343  * Prepare to accept connections.
344  */
345 static int
346 tcp_usr_listen(struct socket *so, struct thread *td)
347 {
348 	int error = 0;
349 	struct inpcb *inp;
350 	struct tcpcb *tp;
351 #ifdef SMP
352 	int cpu;
353 #endif
354 
355 	COMMON_START(so, inp, 0);
356 	if (inp->inp_lport == 0) {
357 		error = in_pcbbind(inp, NULL, td);
358 		if (error != 0)
359 			goto out;
360 	}
361 
362 	tp->t_state = TCPS_LISTEN;
363 	tp->tt_msg = NULL; /* Catch any invalid timer usage */
364 #ifdef SMP
365 	/*
366 	 * We have to set the flag because we can't have other cpus
367 	 * messing with our inp's flags.
368 	 */
369 	inp->inp_flags |= INP_WILDCARD_MP;
370 	for (cpu = 0; cpu < ncpus2; cpu++) {
371 		struct netmsg_inswildcard *msg;
372 
373 		if (cpu == mycpu->gd_cpuid) {
374 			in_pcbinswildcardhash(inp);
375 			continue;
376 		}
377 
378 		msg = kmalloc(sizeof(struct netmsg_inswildcard), M_LWKTMSG,
379 			      M_INTWAIT);
380 		netmsg_init(&msg->nm_netmsg, NULL, &netisr_afree_rport,
381 			    0, in_pcbinswildcardhash_handler);
382 		msg->nm_inp = inp;
383 		msg->nm_pcbinfo = &tcbinfo[cpu];
384 		lwkt_sendmsg(cpu_portfn(cpu), &msg->nm_netmsg.nm_lmsg);
385 	}
386 #else
387 	in_pcbinswildcardhash(inp);
388 #endif
389 	COMMON_END(PRU_LISTEN);
390 }
391 
392 #ifdef INET6
393 static int
394 tcp6_usr_listen(struct socket *so, struct thread *td)
395 {
396 	int error = 0;
397 	struct inpcb *inp;
398 	struct tcpcb *tp;
399 #ifdef SMP
400 	int cpu;
401 #endif
402 
403 	COMMON_START(so, inp, 0);
404 	if (inp->inp_lport == 0) {
405 		if (!(inp->inp_flags & IN6P_IPV6_V6ONLY))
406 			inp->inp_vflag |= INP_IPV4;
407 		else
408 			inp->inp_vflag &= ~INP_IPV4;
409 		error = in6_pcbbind(inp, NULL, td);
410 	}
411 	if (error == 0)
412 		tp->t_state = TCPS_LISTEN;
413 #ifdef SMP
414 	/*
415 	 * We have to set the flag because we can't have other cpus
416 	 * messing with our inp's flags.
417 	 */
418 	inp->inp_flags |= INP_WILDCARD_MP;
419 	for (cpu = 0; cpu < ncpus2; cpu++) {
420 		struct netmsg_inswildcard *msg;
421 
422 		if (cpu == mycpu->gd_cpuid) {
423 			in_pcbinswildcardhash(inp);
424 			continue;
425 		}
426 
427 		msg = kmalloc(sizeof(struct netmsg_inswildcard), M_LWKTMSG,
428 			      M_INTWAIT);
429 		netmsg_init(&msg->nm_netmsg, NULL, &netisr_afree_rport,
430 			    0, in_pcbinswildcardhash_handler);
431 		msg->nm_inp = inp;
432 		msg->nm_pcbinfo = &tcbinfo[cpu];
433 		lwkt_sendmsg(cpu_portfn(cpu), &msg->nm_netmsg.nm_lmsg);
434 	}
435 #else
436 	in_pcbinswildcardhash(inp);
437 #endif
438 	COMMON_END(PRU_LISTEN);
439 }
440 #endif /* INET6 */
441 
442 /*
443  * Initiate connection to peer.
444  * Create a template for use in transmissions on this connection.
445  * Enter SYN_SENT state, and mark socket as connecting.
446  * Start keep-alive timer, and seed output sequence space.
447  * Send initial segment on connection.
448  */
449 static int
450 tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
451 {
452 	int error = 0;
453 	struct inpcb *inp;
454 	struct tcpcb *tp;
455 	struct sockaddr_in *sinp;
456 
457 	COMMON_START(so, inp, 0);
458 
459 	/*
460 	 * Must disallow TCP ``connections'' to multicast addresses.
461 	 */
462 	sinp = (struct sockaddr_in *)nam;
463 	if (sinp->sin_family == AF_INET
464 	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
465 		error = EAFNOSUPPORT;
466 		goto out;
467 	}
468 
469 	if (!prison_remote_ip(td, (struct sockaddr*)sinp)) {
470 		error = EAFNOSUPPORT; /* IPv6 only jail */
471 		goto out;
472 	}
473 
474 	if ((error = tcp_connect(tp, 0, NULL, nam, td)) != 0)
475 		goto out;
476 	COMMON_END(PRU_CONNECT);
477 }
478 
479 #ifdef INET6
480 static int
481 tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
482 {
483 	int error = 0;
484 	struct inpcb *inp;
485 	struct tcpcb *tp;
486 	struct sockaddr_in6 *sin6p;
487 
488 	COMMON_START(so, inp, 0);
489 
490 	/*
491 	 * Must disallow TCP ``connections'' to multicast addresses.
492 	 */
493 	sin6p = (struct sockaddr_in6 *)nam;
494 	if (sin6p->sin6_family == AF_INET6
495 	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
496 		error = EAFNOSUPPORT;
497 		goto out;
498 	}
499 
500 	if (!prison_remote_ip(td, nam)) {
501 		error = EAFNOSUPPORT; /* IPv4 only jail */
502 		goto out;
503 	}
504 
505 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
506 		struct sockaddr_in sin;
507 
508 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
509 			error = EINVAL;
510 			goto out;
511 		}
512 
513 		in6_sin6_2_sin(&sin, sin6p);
514 		inp->inp_vflag |= INP_IPV4;
515 		inp->inp_vflag &= ~INP_IPV6;
516 		error = tcp_connect(tp, 0, NULL, (struct sockaddr *)&sin, td);
517 		if (error)
518 			goto out;
519 		goto out;
520 	}
521 	inp->inp_vflag &= ~INP_IPV4;
522 	inp->inp_vflag |= INP_IPV6;
523 	inp->inp_inc.inc_isipv6 = 1;
524 	if ((error = tcp6_connect(tp, 0, NULL, nam, td)) != 0)
525 		goto out;
526 	error = tcp_output(tp);
527 	COMMON_END(PRU_CONNECT);
528 }
529 #endif /* INET6 */
530 
531 /*
532  * Initiate disconnect from peer.
533  * If connection never passed embryonic stage, just drop;
534  * else if don't need to let data drain, then can just drop anyways,
535  * else have to begin TCP shutdown process: mark socket disconnecting,
536  * drain unread data, state switch to reflect user close, and
537  * send segment (e.g. FIN) to peer.  Socket will be really disconnected
538  * when peer sends FIN and acks ours.
539  *
540  * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
541  */
542 static int
543 tcp_usr_disconnect(struct socket *so)
544 {
545 	int error = 0;
546 	struct inpcb *inp;
547 	struct tcpcb *tp;
548 
549 	COMMON_START(so, inp, 1);
550 	tp = tcp_disconnect(tp);
551 	COMMON_END(PRU_DISCONNECT);
552 }
553 
554 /*
555  * Accept a connection.  Essentially all the work is
556  * done at higher levels; just return the address
557  * of the peer, storing through addr.
558  */
559 static int
560 tcp_usr_accept(struct socket *so, struct sockaddr **nam)
561 {
562 	int error = 0;
563 	struct inpcb *inp;
564 	struct tcpcb *tp = NULL;
565 	TCPDEBUG0;
566 
567 	inp = so->so_pcb;
568 	if (so->so_state & SS_ISDISCONNECTED) {
569 		error = ECONNABORTED;
570 		goto out;
571 	}
572 	if (inp == 0)
573 		return (EINVAL);
574 
575 	tp = intotcpcb(inp);
576 	TCPDEBUG1();
577 	in_setpeeraddr(so, nam);
578 	COMMON_END(PRU_ACCEPT);
579 }
580 
581 #ifdef INET6
582 static int
583 tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
584 {
585 	int error = 0;
586 	struct inpcb *inp;
587 	struct tcpcb *tp = NULL;
588 	TCPDEBUG0;
589 
590 	inp = so->so_pcb;
591 
592 	if (so->so_state & SS_ISDISCONNECTED) {
593 		error = ECONNABORTED;
594 		goto out;
595 	}
596 	if (inp == 0)
597 		return (EINVAL);
598 	tp = intotcpcb(inp);
599 	TCPDEBUG1();
600 	in6_mapped_peeraddr(so, nam);
601 	COMMON_END(PRU_ACCEPT);
602 }
603 #endif /* INET6 */
604 /*
605  * Mark the connection as being incapable of further output.
606  */
607 static int
608 tcp_usr_shutdown(struct socket *so)
609 {
610 	int error = 0;
611 	struct inpcb *inp;
612 	struct tcpcb *tp;
613 
614 	COMMON_START(so, inp, 0);
615 	socantsendmore(so);
616 	tp = tcp_usrclosed(tp);
617 	if (tp)
618 		error = tcp_output(tp);
619 	COMMON_END(PRU_SHUTDOWN);
620 }
621 
622 /*
623  * After a receive, possibly send window update to peer.
624  */
625 static int
626 tcp_usr_rcvd(struct socket *so, int flags)
627 {
628 	int error = 0;
629 	struct inpcb *inp;
630 	struct tcpcb *tp;
631 
632 	COMMON_START(so, inp, 0);
633 	tcp_output(tp);
634 	COMMON_END(PRU_RCVD);
635 }
636 
637 /*
638  * Do a send by putting data in output queue and updating urgent
639  * marker if URG set.  Possibly send more data.  Unlike the other
640  * pru_*() routines, the mbuf chains are our responsibility.  We
641  * must either enqueue them or free them.  The other pru_* routines
642  * generally are caller-frees.
643  */
644 static int
645 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
646 	     struct sockaddr *nam, struct mbuf *control, struct thread *td)
647 {
648 	int error = 0;
649 	struct inpcb *inp;
650 	struct tcpcb *tp;
651 #ifdef INET6
652 	int isipv6;
653 #endif
654 	TCPDEBUG0;
655 
656 	inp = so->so_pcb;
657 
658 	if (inp == NULL) {
659 		/*
660 		 * OOPS! we lost a race, the TCP session got reset after
661 		 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a
662 		 * network interrupt in the non-critical section of sosend().
663 		 */
664 		m_freem(m);
665 		if (control)
666 			m_freem(control);
667 		error = ECONNRESET;	/* XXX EPIPE? */
668 		tp = NULL;
669 		TCPDEBUG1();
670 		goto out;
671 	}
672 #ifdef INET6
673 	isipv6 = nam && nam->sa_family == AF_INET6;
674 #endif /* INET6 */
675 	tp = intotcpcb(inp);
676 	TCPDEBUG1();
677 	if (control) {
678 		/* TCP doesn't do control messages (rights, creds, etc) */
679 		if (control->m_len) {
680 			m_freem(control);
681 			m_freem(m);
682 			error = EINVAL;
683 			goto out;
684 		}
685 		m_freem(control);	/* empty control, just free it */
686 	}
687 
688 	/*
689 	 * Don't let too much OOB data build up
690 	 */
691 	if (flags & PRUS_OOB) {
692 		if (ssb_space(&so->so_snd) < -512) {
693 			m_freem(m);
694 			error = ENOBUFS;
695 			goto out;
696 		}
697 	}
698 
699 	/*
700 	 * Do implied connect if not yet connected.  Any data sent
701 	 * with the connect is handled by tcp_connect() and friends.
702 	 *
703 	 * NOTE!  PROTOCOL THREAD MAY BE CHANGED BY THE CONNECT!
704 	 */
705 	if (nam && tp->t_state < TCPS_SYN_SENT) {
706 #ifdef INET6
707 		if (isipv6)
708 			error = tcp6_connect(tp, flags, m, nam, td);
709 		else
710 #endif /* INET6 */
711 		error = tcp_connect(tp, flags, m, nam, td);
712 #if 0
713 		/* WTF is this doing here? */
714 		tp->snd_wnd = TTCP_CLIENT_SND_WND;
715 		tcp_mss(tp, -1);
716 #endif
717 		goto out;
718 	}
719 
720 	/*
721 	 * Pump the data into the socket.
722 	 */
723 	if (m)
724 		ssb_appendstream(&so->so_snd, m);
725 	if (flags & PRUS_OOB) {
726 		/*
727 		 * According to RFC961 (Assigned Protocols),
728 		 * the urgent pointer points to the last octet
729 		 * of urgent data.  We continue, however,
730 		 * to consider it to indicate the first octet
731 		 * of data past the urgent section.
732 		 * Otherwise, snd_up should be one lower.
733 		 */
734 		tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
735 		tp->t_flags |= TF_FORCE;
736 		error = tcp_output(tp);
737 		tp->t_flags &= ~TF_FORCE;
738 	} else {
739 		if (flags & PRUS_EOF) {
740 			/*
741 			 * Close the send side of the connection after
742 			 * the data is sent.
743 			 */
744 			socantsendmore(so);
745 			tp = tcp_usrclosed(tp);
746 		}
747 		if (tp != NULL) {
748 			if (flags & PRUS_MORETOCOME)
749 				tp->t_flags |= TF_MORETOCOME;
750 			error = tcp_output(tp);
751 			if (flags & PRUS_MORETOCOME)
752 				tp->t_flags &= ~TF_MORETOCOME;
753 		}
754 	}
755 	COMMON_END((flags & PRUS_OOB) ? PRU_SENDOOB :
756 		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
757 }
758 
759 /*
760  * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
761  *	 will sofree() it when we return.
762  */
763 static int
764 tcp_usr_abort(struct socket *so)
765 {
766 	int error = 0;
767 	struct inpcb *inp;
768 	struct tcpcb *tp;
769 
770 	COMMON_START(so, inp, 1);
771 	tp = tcp_drop(tp, ECONNABORTED);
772 	COMMON_END(PRU_ABORT);
773 }
774 
775 /*
776  * Receive out-of-band data.
777  */
778 static int
779 tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
780 {
781 	int error = 0;
782 	struct inpcb *inp;
783 	struct tcpcb *tp;
784 
785 	COMMON_START(so, inp, 0);
786 	if ((so->so_oobmark == 0 &&
787 	     (so->so_state & SS_RCVATMARK) == 0) ||
788 	    so->so_options & SO_OOBINLINE ||
789 	    tp->t_oobflags & TCPOOB_HADDATA) {
790 		error = EINVAL;
791 		goto out;
792 	}
793 	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
794 		error = EWOULDBLOCK;
795 		goto out;
796 	}
797 	m->m_len = 1;
798 	*mtod(m, caddr_t) = tp->t_iobc;
799 	if ((flags & MSG_PEEK) == 0)
800 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
801 	COMMON_END(PRU_RCVOOB);
802 }
803 
804 /* xxx - should be const */
805 struct pr_usrreqs tcp_usrreqs = {
806 	.pru_abort = tcp_usr_abort,
807 	.pru_accept = tcp_usr_accept,
808 	.pru_attach = tcp_usr_attach,
809 	.pru_bind = tcp_usr_bind,
810 	.pru_connect = tcp_usr_connect,
811 	.pru_connect2 = pru_connect2_notsupp,
812 	.pru_control = in_control,
813 	.pru_detach = tcp_usr_detach,
814 	.pru_disconnect = tcp_usr_disconnect,
815 	.pru_listen = tcp_usr_listen,
816 	.pru_peeraddr = in_setpeeraddr,
817 	.pru_rcvd = tcp_usr_rcvd,
818 	.pru_rcvoob = tcp_usr_rcvoob,
819 	.pru_send = tcp_usr_send,
820 	.pru_sense = pru_sense_null,
821 	.pru_shutdown = tcp_usr_shutdown,
822 	.pru_sockaddr = in_setsockaddr,
823 	.pru_sosend = sosend,
824 	.pru_soreceive = soreceive
825 };
826 
827 #ifdef INET6
828 struct pr_usrreqs tcp6_usrreqs = {
829 	.pru_abort = tcp_usr_abort,
830 	.pru_accept = tcp6_usr_accept,
831 	.pru_attach = tcp_usr_attach,
832 	.pru_bind = tcp6_usr_bind,
833 	.pru_connect = tcp6_usr_connect,
834 	.pru_connect2 = pru_connect2_notsupp,
835 	.pru_control = in6_control,
836 	.pru_detach = tcp_usr_detach,
837 	.pru_disconnect = tcp_usr_disconnect,
838 	.pru_listen = tcp6_usr_listen,
839 	.pru_peeraddr = in6_mapped_peeraddr,
840 	.pru_rcvd = tcp_usr_rcvd,
841 	.pru_rcvoob = tcp_usr_rcvoob,
842 	.pru_send = tcp_usr_send,
843 	.pru_sense = pru_sense_null,
844 	.pru_shutdown = tcp_usr_shutdown,
845 	.pru_sockaddr = in6_mapped_sockaddr,
846 	.pru_sosend = sosend,
847 	.pru_soreceive = soreceive
848 };
849 #endif /* INET6 */
850 
851 static int
852 tcp_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf *m,
853 		  struct sockaddr_in *sin, struct sockaddr_in *if_sin)
854 {
855 	struct inpcb *inp = tp->t_inpcb, *oinp;
856 	struct socket *so = inp->inp_socket;
857 	struct route *ro = &inp->inp_route;
858 
859 	oinp = in_pcblookup_hash(&tcbinfo[mycpu->gd_cpuid],
860 	    sin->sin_addr, sin->sin_port,
861 	    inp->inp_laddr.s_addr != INADDR_ANY ?
862 		inp->inp_laddr : if_sin->sin_addr,
863 	    inp->inp_lport, 0, NULL);
864 	if (oinp != NULL) {
865 		m_freem(m);
866 		return (EADDRINUSE);
867 	}
868 	if (inp->inp_laddr.s_addr == INADDR_ANY)
869 		inp->inp_laddr = if_sin->sin_addr;
870 	inp->inp_faddr = sin->sin_addr;
871 	inp->inp_fport = sin->sin_port;
872 	inp->inp_cpcbinfo = &tcbinfo[mycpu->gd_cpuid];
873 	in_pcbinsconnhash(inp);
874 
875 	/*
876 	 * We are now on the inpcb's owner CPU, if the cached route was
877 	 * freed because the rtentry's owner CPU is not the current CPU
878 	 * (e.g. in tcp_connect()), then we try to reallocate it here with
879 	 * the hope that a rtentry may be cloned from a RTF_PRCLONING
880 	 * rtentry.
881 	 */
882 	if (!(inp->inp_socket->so_options & SO_DONTROUTE) && /*XXX*/
883 	    ro->ro_rt == NULL) {
884 		bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
885 		ro->ro_dst.sa_family = AF_INET;
886 		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
887 		((struct sockaddr_in *)&ro->ro_dst)->sin_addr =
888 			sin->sin_addr;
889 		rtalloc(ro);
890 	}
891 
892 	/*
893 	 * Now that no more errors can occur, change the protocol processing
894 	 * port to the current thread (which is the correct thread).
895 	 *
896 	 * Create TCP timer message now; we are on the tcpcb's owner
897 	 * CPU/thread.
898 	 */
899 	sosetport(so, &curthread->td_msgport);
900 	tcp_create_timermsg(tp, &curthread->td_msgport);
901 
902 	/*
903 	 * Compute window scaling to request.  Use a larger scaling then
904 	 * needed for the initial receive buffer in case the receive buffer
905 	 * gets expanded.
906 	 */
907 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
908 		tp->request_r_scale = TCP_MIN_WINSHIFT;
909 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
910 	       (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat
911 	) {
912 		tp->request_r_scale++;
913 	}
914 
915 	soisconnecting(so);
916 	tcpstat.tcps_connattempt++;
917 	tp->t_state = TCPS_SYN_SENT;
918 	tcp_callout_reset(tp, tp->tt_keep, tcp_keepinit, tcp_timer_keep);
919 	tp->iss = tcp_new_isn(tp);
920 	tcp_sendseqinit(tp);
921 	if (m) {
922 		ssb_appendstream(&so->so_snd, m);
923 		m = NULL;
924 		if (flags & PRUS_OOB)
925 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
926 	}
927 
928 	/*
929 	 * Close the send side of the connection after
930 	 * the data is sent if flagged.
931 	 */
932 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
933 		socantsendmore(so);
934 		tp = tcp_usrclosed(tp);
935 	}
936 	return (tcp_output(tp));
937 }
938 
939 #ifdef SMP
940 
941 struct netmsg_tcp_connect {
942 	struct netmsg		nm_netmsg;
943 	struct tcpcb		*nm_tp;
944 	struct sockaddr_in	*nm_sin;
945 	struct sockaddr_in	*nm_ifsin;
946 	int			nm_flags;
947 	struct mbuf		*nm_m;
948 };
949 
950 static void
951 tcp_connect_handler(netmsg_t netmsg)
952 {
953 	struct netmsg_tcp_connect *msg = (void *)netmsg;
954 	int error;
955 
956 	error = tcp_connect_oncpu(msg->nm_tp, msg->nm_flags, msg->nm_m,
957 				  msg->nm_sin, msg->nm_ifsin);
958 	lwkt_replymsg(&msg->nm_netmsg.nm_lmsg, error);
959 }
960 
961 struct netmsg_tcp6_connect {
962 	struct netmsg		nm_netmsg;
963 	struct tcpcb		*nm_tp;
964 	struct sockaddr_in6	*nm_sin6;
965 	struct in6_addr		*nm_addr6;
966 	int			nm_flags;
967 	struct mbuf		*nm_m;
968 };
969 
970 #ifdef INET6
971 static void
972 tcp6_connect_handler(netmsg_t netmsg)
973 {
974 	struct netmsg_tcp6_connect *msg = (void *)netmsg;
975 	int error;
976 
977 	error = tcp6_connect_oncpu(msg->nm_tp, msg->nm_flags, msg->nm_m,
978 				   msg->nm_sin6, msg->nm_addr6);
979 	lwkt_replymsg(&msg->nm_netmsg.nm_lmsg, error);
980 }
981 #endif
982 
983 #endif /* SMP */
984 
985 /*
986  * Common subroutine to open a TCP connection to remote host specified
987  * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
988  * port number if needed.  Call in_pcbladdr to do the routing and to choose
989  * a local host address (interface).
990  * Initialize connection parameters and enter SYN-SENT state.
991  */
992 static int
993 tcp_connect(struct tcpcb *tp, int flags, struct mbuf *m,
994 	    struct sockaddr *nam, struct thread *td)
995 {
996 	struct inpcb *inp = tp->t_inpcb;
997 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
998 	struct sockaddr_in *if_sin;
999 	int error;
1000 #ifdef SMP
1001 	lwkt_port_t port;
1002 #endif
1003 
1004 	/*
1005 	 * Bind if we have to
1006 	 */
1007 	if (inp->inp_lport == 0) {
1008 		error = in_pcbbind(inp, NULL, td);
1009 		if (error) {
1010 			m_freem(m);
1011 			return (error);
1012 		}
1013 	}
1014 
1015 	/*
1016 	 * Calculate the correct protocol processing thread.  The connect
1017 	 * operation must run there.
1018 	 */
1019 	error = in_pcbladdr(inp, nam, &if_sin, td);
1020 	if (error) {
1021 		m_freem(m);
1022 		return (error);
1023 	}
1024 
1025 #ifdef SMP
1026 	port = tcp_addrport(sin->sin_addr.s_addr, sin->sin_port,
1027 	    inp->inp_laddr.s_addr ?
1028 		inp->inp_laddr.s_addr : if_sin->sin_addr.s_addr,
1029 	    inp->inp_lport);
1030 
1031 	if (port != &curthread->td_msgport) {
1032 		struct netmsg_tcp_connect msg;
1033 		struct route *ro = &inp->inp_route;
1034 
1035 		/*
1036 		 * in_pcbladdr() may have allocated a route entry for us
1037 		 * on the current CPU, but we need a route entry on the
1038 		 * inpcb's owner CPU, so free it here.
1039 		 */
1040 		if (ro->ro_rt != NULL)
1041 			RTFREE(ro->ro_rt);
1042 		bzero(ro, sizeof(*ro));
1043 
1044 		/*
1045 		 * NOTE: We haven't set so->so_port yet do not pass so
1046 		 *	 to netmsg_init() or it will be improperly forwarded.
1047 		 */
1048 		netmsg_init(&msg.nm_netmsg, NULL, &curthread->td_msgport,
1049 			    0, tcp_connect_handler);
1050 		msg.nm_tp = tp;
1051 		msg.nm_sin = sin;
1052 		msg.nm_ifsin = if_sin;
1053 		msg.nm_flags = flags;
1054 		msg.nm_m = m;
1055 		error = lwkt_domsg(port, &msg.nm_netmsg.nm_lmsg, 0);
1056 	} else {
1057 		error = tcp_connect_oncpu(tp, flags, m, sin, if_sin);
1058 	}
1059 #else
1060 	error = tcp_connect_oncpu(tp, flags, m, sin, if_sin);
1061 #endif
1062 	return (error);
1063 }
1064 
1065 #ifdef INET6
1066 
1067 static int
1068 tcp6_connect(struct tcpcb *tp, int flags, struct mbuf *m,
1069 	     struct sockaddr *nam, struct thread *td)
1070 {
1071 	struct inpcb *inp = tp->t_inpcb;
1072 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1073 	struct in6_addr *addr6;
1074 #ifdef SMP
1075 	lwkt_port_t port;
1076 #endif
1077 	int error;
1078 
1079 	if (inp->inp_lport == 0) {
1080 		error = in6_pcbbind(inp, NULL, td);
1081 		if (error) {
1082 			m_freem(m);
1083 			return (error);
1084 		}
1085 	}
1086 
1087 	/*
1088 	 * Cannot simply call in_pcbconnect, because there might be an
1089 	 * earlier incarnation of this same connection still in
1090 	 * TIME_WAIT state, creating an ADDRINUSE error.
1091 	 */
1092 	error = in6_pcbladdr(inp, nam, &addr6, td);
1093 	if (error) {
1094 		m_freem(m);
1095 		return (error);
1096 	}
1097 
1098 #ifdef SMP
1099 	port = tcp6_addrport();	/* XXX hack for now, always cpu0 */
1100 
1101 	if (port != &curthread->td_msgport) {
1102 		struct netmsg_tcp6_connect msg;
1103 		struct route *ro = &inp->inp_route;
1104 
1105 		/*
1106 		 * in_pcbladdr() may have allocated a route entry for us
1107 		 * on the current CPU, but we need a route entry on the
1108 		 * inpcb's owner CPU, so free it here.
1109 		 */
1110 		if (ro->ro_rt != NULL)
1111 			RTFREE(ro->ro_rt);
1112 		bzero(ro, sizeof(*ro));
1113 
1114 		netmsg_init(&msg.nm_netmsg, NULL, &curthread->td_msgport,
1115 			    0, tcp6_connect_handler);
1116 		msg.nm_tp = tp;
1117 		msg.nm_sin6 = sin6;
1118 		msg.nm_addr6 = addr6;
1119 		msg.nm_flags = flags;
1120 		msg.nm_m = m;
1121 		error = lwkt_domsg(port, &msg.nm_netmsg.nm_lmsg, 0);
1122 	} else {
1123 		error = tcp6_connect_oncpu(tp, flags, m, sin6, addr6);
1124 	}
1125 #else
1126 	error = tcp6_connect_oncpu(tp, flags, m, sin6, addr6);
1127 #endif
1128 	return (error);
1129 }
1130 
1131 static int
1132 tcp6_connect_oncpu(struct tcpcb *tp, int flags, struct mbuf *m,
1133 		   struct sockaddr_in6 *sin6, struct in6_addr *addr6)
1134 {
1135 	struct inpcb *inp = tp->t_inpcb;
1136 	struct socket *so = inp->inp_socket;
1137 	struct inpcb *oinp;
1138 
1139 	/*
1140 	 * Cannot simply call in_pcbconnect, because there might be an
1141 	 * earlier incarnation of this same connection still in
1142 	 * TIME_WAIT state, creating an ADDRINUSE error.
1143 	 */
1144 	oinp = in6_pcblookup_hash(inp->inp_cpcbinfo,
1145 				  &sin6->sin6_addr, sin6->sin6_port,
1146 				  IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ?
1147 				      addr6 : &inp->in6p_laddr,
1148 				  inp->inp_lport,  0, NULL);
1149 	if (oinp) {
1150 		m_freem(m);
1151 		return (EADDRINUSE);
1152 	}
1153 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
1154 		inp->in6p_laddr = *addr6;
1155 	inp->in6p_faddr = sin6->sin6_addr;
1156 	inp->inp_fport = sin6->sin6_port;
1157 	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != 0)
1158 		inp->in6p_flowinfo = sin6->sin6_flowinfo;
1159 	in_pcbinsconnhash(inp);
1160 
1161 	/*
1162 	 * Now that no more errors can occur, change the protocol processing
1163 	 * port to the current thread (which is the correct thread).
1164 	 *
1165 	 * Create TCP timer message now; we are on the tcpcb's owner
1166 	 * CPU/thread.
1167 	 */
1168 	sosetport(so, &curthread->td_msgport);
1169 	tcp_create_timermsg(tp, &curthread->td_msgport);
1170 
1171 	/* Compute window scaling to request.  */
1172 	if (tp->request_r_scale < TCP_MIN_WINSHIFT)
1173 		tp->request_r_scale = TCP_MIN_WINSHIFT;
1174 	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
1175 	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.ssb_hiwat) {
1176 		tp->request_r_scale++;
1177 	}
1178 
1179 	soisconnecting(so);
1180 	tcpstat.tcps_connattempt++;
1181 	tp->t_state = TCPS_SYN_SENT;
1182 	tcp_callout_reset(tp, tp->tt_keep, tcp_keepinit, tcp_timer_keep);
1183 	tp->iss = tcp_new_isn(tp);
1184 	tcp_sendseqinit(tp);
1185 	if (m) {
1186 		ssb_appendstream(&so->so_snd, m);
1187 		m = NULL;
1188 		if (flags & PRUS_OOB)
1189 			tp->snd_up = tp->snd_una + so->so_snd.ssb_cc;
1190 	}
1191 
1192 	/*
1193 	 * Close the send side of the connection after
1194 	 * the data is sent if flagged.
1195 	 */
1196 	if ((flags & (PRUS_OOB|PRUS_EOF)) == PRUS_EOF) {
1197 		socantsendmore(so);
1198 		tp = tcp_usrclosed(tp);
1199 	}
1200 	return (tcp_output(tp));
1201 }
1202 
1203 #endif /* INET6 */
1204 
1205 /*
1206  * The new sockopt interface makes it possible for us to block in the
1207  * copyin/out step (if we take a page fault).  Taking a page fault while
1208  * in a critical section is probably a Bad Thing.  (Since sockets and pcbs
1209  * both now use TSM, there probably isn't any need for this function to
1210  * run in a critical section any more.  This needs more examination.)
1211  */
1212 int
1213 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
1214 {
1215 	int	error, opt, optval;
1216 	struct	inpcb *inp;
1217 	struct	tcpcb *tp;
1218 
1219 	error = 0;
1220 	inp = so->so_pcb;
1221 	if (inp == NULL)
1222 		return (ECONNRESET);
1223 
1224 	if (sopt->sopt_level != IPPROTO_TCP) {
1225 #ifdef INET6
1226 		if (INP_CHECK_SOCKAF(so, AF_INET6))
1227 			error = ip6_ctloutput(so, sopt);
1228 		else
1229 #endif /* INET6 */
1230 		error = ip_ctloutput(so, sopt);
1231 		return (error);
1232 	}
1233 	tp = intotcpcb(inp);
1234 
1235 	switch (sopt->sopt_dir) {
1236 	case SOPT_SET:
1237 		error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1238 				      sizeof optval);
1239 		if (error)
1240 			break;
1241 		switch (sopt->sopt_name) {
1242 #ifdef TCP_SIGNATURE
1243 		case TCP_SIGNATURE_ENABLE:
1244 			if (optval > 0)
1245 				tp->t_flags |= TF_SIGNATURE;
1246 			else
1247 				tp->t_flags &= ~TF_SIGNATURE;
1248 			break;
1249 #endif /* TCP_SIGNATURE */
1250 		case TCP_NODELAY:
1251 		case TCP_NOOPT:
1252 			switch (sopt->sopt_name) {
1253 			case TCP_NODELAY:
1254 				opt = TF_NODELAY;
1255 				break;
1256 			case TCP_NOOPT:
1257 				opt = TF_NOOPT;
1258 				break;
1259 			default:
1260 				opt = 0; /* dead code to fool gcc */
1261 				break;
1262 			}
1263 
1264 			if (optval)
1265 				tp->t_flags |= opt;
1266 			else
1267 				tp->t_flags &= ~opt;
1268 			break;
1269 
1270 		case TCP_NOPUSH:
1271 			if (optval)
1272 				tp->t_flags |= TF_NOPUSH;
1273 			else {
1274 				tp->t_flags &= ~TF_NOPUSH;
1275 				error = tcp_output(tp);
1276 			}
1277 			break;
1278 
1279 		case TCP_MAXSEG:
1280 			/*
1281 			 * Must be between 0 and maxseg.  If the requested
1282 			 * maxseg is too small to satisfy the desired minmss,
1283 			 * pump it up (silently so sysctl modifications of
1284 			 * minmss do not create unexpected program failures).
1285 			 * Handle degenerate cases.
1286 			 */
1287 			if (optval > 0 && optval <= tp->t_maxseg) {
1288 				if (optval + 40 < tcp_minmss) {
1289 					optval = tcp_minmss - 40;
1290 					if (optval < 0)
1291 						optval = 1;
1292 				}
1293 				tp->t_maxseg = optval;
1294 			} else {
1295 				error = EINVAL;
1296 			}
1297 			break;
1298 
1299 		default:
1300 			error = ENOPROTOOPT;
1301 			break;
1302 		}
1303 		break;
1304 
1305 	case SOPT_GET:
1306 		switch (sopt->sopt_name) {
1307 #ifdef TCP_SIGNATURE
1308 		case TCP_SIGNATURE_ENABLE:
1309 			optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
1310 			break;
1311 #endif /* TCP_SIGNATURE */
1312 		case TCP_NODELAY:
1313 			optval = tp->t_flags & TF_NODELAY;
1314 			break;
1315 		case TCP_MAXSEG:
1316 			optval = tp->t_maxseg;
1317 			break;
1318 		case TCP_NOOPT:
1319 			optval = tp->t_flags & TF_NOOPT;
1320 			break;
1321 		case TCP_NOPUSH:
1322 			optval = tp->t_flags & TF_NOPUSH;
1323 			break;
1324 		default:
1325 			error = ENOPROTOOPT;
1326 			break;
1327 		}
1328 		if (error == 0)
1329 			soopt_from_kbuf(sopt, &optval, sizeof optval);
1330 		break;
1331 	}
1332 	return (error);
1333 }
1334 
1335 /*
1336  * tcp_sendspace and tcp_recvspace are the default send and receive window
1337  * sizes, respectively.  These are obsolescent (this information should
1338  * be set by the route).
1339  *
1340  * Use a default that does not require tcp window scaling to be turned
1341  * on.  Individual programs or the administrator can increase the default.
1342  */
1343 u_long	tcp_sendspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1344 SYSCTL_INT(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
1345     &tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
1346 u_long	tcp_recvspace = 57344;	/* largest multiple of PAGE_SIZE < 64k */
1347 SYSCTL_INT(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
1348     &tcp_recvspace , 0, "Maximum incoming TCP datagram size");
1349 
1350 /*
1351  * Attach TCP protocol to socket, allocating
1352  * internet protocol control block, tcp control block,
1353  * bufer space, and entering LISTEN state if to accept connections.
1354  */
1355 static int
1356 tcp_attach(struct socket *so, struct pru_attach_info *ai)
1357 {
1358 	struct tcpcb *tp;
1359 	struct inpcb *inp;
1360 	int error;
1361 	int cpu;
1362 #ifdef INET6
1363 	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
1364 #endif
1365 
1366 	if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
1367 		lwkt_gettoken(&so->so_rcv.ssb_token);
1368 		error = soreserve(so, tcp_sendspace, tcp_recvspace,
1369 				  ai->sb_rlimit);
1370 		lwkt_reltoken(&so->so_rcv.ssb_token);
1371 		if (error)
1372 			return (error);
1373 	}
1374 	atomic_set_int(&so->so_rcv.ssb_flags, SSB_AUTOSIZE);
1375 	atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOSIZE);
1376 	cpu = mycpu->gd_cpuid;
1377 	error = in_pcballoc(so, &tcbinfo[cpu]);
1378 	if (error)
1379 		return (error);
1380 	inp = so->so_pcb;
1381 #ifdef INET6
1382 	if (isipv6) {
1383 		inp->inp_vflag |= INP_IPV6;
1384 		inp->in6p_hops = -1;	/* use kernel default */
1385 	}
1386 	else
1387 #endif
1388 	inp->inp_vflag |= INP_IPV4;
1389 	tp = tcp_newtcpcb(inp);
1390 	if (tp == NULL) {
1391 		/*
1392 		 * Make sure the socket is destroyed by the pcbdetach.
1393 		 */
1394 		soreference(so);
1395 #ifdef INET6
1396 		if (isipv6)
1397 			in6_pcbdetach(inp);
1398 		else
1399 #endif
1400 		in_pcbdetach(inp);
1401 		sofree(so);	/* from ref above */
1402 		return (ENOBUFS);
1403 	}
1404 	tp->t_state = TCPS_CLOSED;
1405 	so->so_port = tcp_soport_attach(so);
1406 	return (0);
1407 }
1408 
1409 /*
1410  * Initiate (or continue) disconnect.
1411  * If embryonic state, just send reset (once).
1412  * If in ``let data drain'' option and linger null, just drop.
1413  * Otherwise (hard), mark socket disconnecting and drop
1414  * current input data; switch states based on user close, and
1415  * send segment to peer (with FIN).
1416  */
1417 static struct tcpcb *
1418 tcp_disconnect(struct tcpcb *tp)
1419 {
1420 	struct socket *so = tp->t_inpcb->inp_socket;
1421 
1422 	if (tp->t_state < TCPS_ESTABLISHED) {
1423 		tp = tcp_close(tp);
1424 	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
1425 		tp = tcp_drop(tp, 0);
1426 	} else {
1427 		lwkt_gettoken(&so->so_rcv.ssb_token);
1428 		soisdisconnecting(so);
1429 		sbflush(&so->so_rcv.sb);
1430 		tp = tcp_usrclosed(tp);
1431 		if (tp)
1432 			tcp_output(tp);
1433 		lwkt_reltoken(&so->so_rcv.ssb_token);
1434 	}
1435 	return (tp);
1436 }
1437 
1438 /*
1439  * User issued close, and wish to trail through shutdown states:
1440  * if never received SYN, just forget it.  If got a SYN from peer,
1441  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
1442  * If already got a FIN from peer, then almost done; go to LAST_ACK
1443  * state.  In all other cases, have already sent FIN to peer (e.g.
1444  * after PRU_SHUTDOWN), and just have to play tedious game waiting
1445  * for peer to send FIN or not respond to keep-alives, etc.
1446  * We can let the user exit from the close as soon as the FIN is acked.
1447  */
1448 static struct tcpcb *
1449 tcp_usrclosed(struct tcpcb *tp)
1450 {
1451 
1452 	switch (tp->t_state) {
1453 
1454 	case TCPS_CLOSED:
1455 	case TCPS_LISTEN:
1456 		tp->t_state = TCPS_CLOSED;
1457 		tp = tcp_close(tp);
1458 		break;
1459 
1460 	case TCPS_SYN_SENT:
1461 	case TCPS_SYN_RECEIVED:
1462 		tp->t_flags |= TF_NEEDFIN;
1463 		break;
1464 
1465 	case TCPS_ESTABLISHED:
1466 		tp->t_state = TCPS_FIN_WAIT_1;
1467 		break;
1468 
1469 	case TCPS_CLOSE_WAIT:
1470 		tp->t_state = TCPS_LAST_ACK;
1471 		break;
1472 	}
1473 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
1474 		soisdisconnected(tp->t_inpcb->inp_socket);
1475 		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
1476 		if (tp->t_state == TCPS_FIN_WAIT_2) {
1477 			tcp_callout_reset(tp, tp->tt_2msl, tcp_maxidle,
1478 			    tcp_timer_2msl);
1479 		}
1480 	}
1481 	return (tp);
1482 }
1483