xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /*	$FreeBSD$	*/
2 /*	$KAME: udp6_usrreq.c,v 1.17 2000/10/13 17:46:21 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
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 project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1989, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *	This product includes software developed by the University of
48  *	California, Berkeley and its contributors.
49  * 4. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
66  */
67 
68 #include "opt_inet.h"
69 #include "opt_inet6.h"
70 #include "opt_ipsec.h"
71 
72 #include <sys/param.h>
73 #include <sys/kernel.h>
74 #include <sys/mbuf.h>
75 #include <sys/protosw.h>
76 #include <sys/socket.h>
77 #include <sys/socketvar.h>
78 #include <sys/sysctl.h>
79 #include <sys/errno.h>
80 #include <sys/stat.h>
81 #include <sys/systm.h>
82 #include <sys/syslog.h>
83 #include <sys/proc.h>
84 
85 #include <net/if.h>
86 #include <net/route.h>
87 #include <net/if_types.h>
88 
89 #include <netinet/in.h>
90 #include <netinet/in_systm.h>
91 #include <netinet/ip.h>
92 #include <netinet/in_pcb.h>
93 #include <netinet/in_var.h>
94 #include <netinet/ip_var.h>
95 #include <netinet/udp.h>
96 #include <netinet/udp_var.h>
97 #include <netinet/ip6.h>
98 #include <netinet6/ip6_var.h>
99 #include <netinet6/in6_pcb.h>
100 #include <netinet/icmp6.h>
101 #include <netinet6/udp6_var.h>
102 #include <netinet6/ip6protosw.h>
103 
104 #ifdef IPSEC
105 #include <netinet6/ipsec.h>
106 #include <netinet6/ipsec6.h>
107 #endif /*IPSEC*/
108 
109 #include "faith.h"
110 
111 /*
112  * UDP protocol inplementation.
113  * Per RFC 768, August, 1980.
114  */
115 
116 extern	struct protosw inetsw[];
117 static	int in6_mcmatch __P((struct inpcb *, struct in6_addr *, struct ifnet *));
118 static	int udp6_detach __P((struct socket *so));
119 
120 static int
121 in6_mcmatch(in6p, ia6, ifp)
122 	struct inpcb *in6p;
123 	register struct in6_addr *ia6;
124 	struct ifnet *ifp;
125 {
126 	struct ip6_moptions *im6o = in6p->in6p_moptions;
127 	struct in6_multi_mship *imm;
128 
129 	if (im6o == NULL)
130 		return 0;
131 
132 	for (imm = im6o->im6o_memberships.lh_first; imm != NULL;
133 	     imm = imm->i6mm_chain.le_next) {
134 		if ((ifp == NULL ||
135 		     imm->i6mm_maddr->in6m_ifp == ifp) &&
136 		    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
137 				       ia6))
138 			return 1;
139 	}
140 	return 0;
141 }
142 
143 int
144 udp6_input(mp, offp, proto)
145 	struct mbuf **mp;
146 	int *offp, proto;
147 {
148 	struct mbuf *m = *mp;
149 	register struct ip6_hdr *ip6;
150 	register struct udphdr *uh;
151 	register struct inpcb *in6p;
152 	struct	mbuf *opts = 0;
153 	int off = *offp;
154 	int plen, ulen;
155 	struct sockaddr_in6 udp_in6;
156 
157 #if defined(NFAITH) && 0 < NFAITH
158 	if (m->m_pkthdr.rcvif) {
159 		if (m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
160 			/* XXX send icmp6 host/port unreach? */
161 			m_freem(m);
162 			return IPPROTO_DONE;
163 		}
164 	}
165 #endif
166 	udpstat.udps_ipackets++;
167 
168 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
169 
170 	ip6 = mtod(m, struct ip6_hdr *);
171 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
172 	uh = (struct udphdr *)((caddr_t)ip6 + off);
173 	ulen = ntohs((u_short)uh->uh_ulen);
174 
175 	if (plen != ulen) {
176 		udpstat.udps_badlen++;
177 		goto bad;
178 	}
179 
180 	/*
181 	 * Checksum extended UDP header and data.
182 	 */
183 	if (uh->uh_sum == 0)
184 		udpstat.udps_nosum++;
185 	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
186 		udpstat.udps_badsum++;
187 		goto bad;
188 	}
189 
190 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
191 		struct	inpcb *last;
192 
193 		/*
194 		 * Deliver a multicast datagram to all sockets
195 		 * for which the local and remote addresses and ports match
196 		 * those of the incoming datagram.  This allows more than
197 		 * one process to receive multicasts on the same port.
198 		 * (This really ought to be done for unicast datagrams as
199 		 * well, but that would cause problems with existing
200 		 * applications that open both address-specific sockets and
201 		 * a wildcard socket listening to the same port -- they would
202 		 * end up receiving duplicates of every unicast datagram.
203 		 * Those applications open the multiple sockets to overcome an
204 		 * inadequacy of the UDP socket interface, but for backwards
205 		 * compatibility we avoid the problem here rather than
206 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
207 		 */
208 
209 		/*
210 		 * In a case that laddr should be set to the link-local
211 		 * address (this happens in RIPng), the multicast address
212 		 * specified in the received packet does not match with
213 		 * laddr. To cure this situation, the matching is relaxed
214 		 * if the receiving interface is the same as one specified
215 		 * in the socket and if the destination multicast address
216 		 * matches one of the multicast groups specified in the socket.
217 		 */
218 
219 		/*
220 		 * Construct sockaddr format source address.
221 		 */
222 		init_sin6(&udp_in6, m); /* general init */
223 		udp_in6.sin6_port = uh->uh_sport;
224 		/*
225 		 * KAME note: usually we drop udphdr from mbuf here.
226 		 * We need udphdr for IPsec processing so we do that later.
227 		 */
228 
229 		/*
230 		 * Locate pcb(s) for datagram.
231 		 * (Algorithm copied from raw_intr().)
232 		 */
233 		last = NULL;
234 		LIST_FOREACH(in6p, &udb, inp_list) {
235 			if ((in6p->inp_vflag & INP_IPV6) == 0)
236 				continue;
237 			if (in6p->in6p_lport != uh->uh_dport)
238 				continue;
239 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
240 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
241 							&ip6->ip6_dst) &&
242 				    !in6_mcmatch(in6p, &ip6->ip6_dst,
243 						 m->m_pkthdr.rcvif))
244 					continue;
245 			}
246 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
247 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
248 							&ip6->ip6_src) ||
249 				   in6p->in6p_fport != uh->uh_sport)
250 					continue;
251 			}
252 
253 			if (last != NULL) {
254 				struct	mbuf *n;
255 
256 #ifdef IPSEC
257 				/*
258 				 * Check AH/ESP integrity.
259 				 */
260 				if (ipsec6_in_reject_so(m, last->inp_socket))
261 					ipsec6stat.in_polvio++;
262 					/* do not inject data into pcb */
263 				else
264 #endif /*IPSEC*/
265 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
266 					/*
267 					 * KAME NOTE: do not
268 					 * m_copy(m, offset, ...) above.
269 					 * sbappendaddr() expects M_PKTHDR,
270 					 * and m_copy() will copy M_PKTHDR
271 					 * only if offset is 0.
272 					 */
273 					if (last->in6p_flags & IN6P_CONTROLOPTS
274 					    || last->in6p_socket->so_options & SO_TIMESTAMP)
275 						ip6_savecontrol(last, &opts,
276 								ip6, n);
277 					m_adj(n, off + sizeof(struct udphdr));
278 					if (sbappendaddr(&last->in6p_socket->so_rcv,
279 							(struct sockaddr *)&udp_in6,
280 							n, opts) == 0) {
281 						m_freem(n);
282 						if (opts)
283 							m_freem(opts);
284 						udpstat.udps_fullsock++;
285 					} else
286 						sorwakeup(last->in6p_socket);
287 					opts = 0;
288 				}
289 			}
290 			last = in6p;
291 			/*
292 			 * Don't look for additional matches if this one does
293 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
294 			 * socket options set.  This heuristic avoids searching
295 			 * through all pcbs in the common case of a non-shared
296 			 * port.  It assumes that an application will never
297 			 * clear these options after setting them.
298 			 */
299 			if ((last->in6p_socket->so_options &
300 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
301 				break;
302 		}
303 
304 		if (last == NULL) {
305 			/*
306 			 * No matching pcb found; discard datagram.
307 			 * (No need to send an ICMP Port Unreachable
308 			 * for a broadcast or multicast datgram.)
309 			 */
310 			udpstat.udps_noport++;
311 			udpstat.udps_noportmcast++;
312 			goto bad;
313 		}
314 #ifdef IPSEC
315 		/*
316 		 * Check AH/ESP integrity.
317 		 */
318 		if (ipsec6_in_reject_so(m, last->inp_socket)) {
319 			ipsec6stat.in_polvio++;
320 			goto bad;
321 		}
322 #endif /*IPSEC*/
323 		if (last->in6p_flags & IN6P_CONTROLOPTS
324 		    || last->in6p_socket->so_options & SO_TIMESTAMP)
325 			ip6_savecontrol(last, &opts, ip6, m);
326 
327 		m_adj(m, off + sizeof(struct udphdr));
328 		if (sbappendaddr(&last->in6p_socket->so_rcv,
329 				(struct sockaddr *)&udp_in6,
330 				m, opts) == 0) {
331 			udpstat.udps_fullsock++;
332 			goto bad;
333 		}
334 		sorwakeup(last->in6p_socket);
335 		return IPPROTO_DONE;
336 	}
337 	/*
338 	 * Locate pcb for datagram.
339 	 */
340 	in6p = in6_pcblookup_hash(&udbinfo, &ip6->ip6_src, uh->uh_sport,
341 				  &ip6->ip6_dst, uh->uh_dport, 1,
342 				  m->m_pkthdr.rcvif);
343 	if (in6p == 0) {
344 		if (log_in_vain) {
345 			char buf[INET6_ADDRSTRLEN];
346 
347 			strcpy(buf, ip6_sprintf(&ip6->ip6_dst));
348 			log(LOG_INFO,
349 			    "Connection attempt to UDP %s:%d from %s:%d\n",
350 			    buf, ntohs(uh->uh_dport),
351 			    ip6_sprintf(&ip6->ip6_src), ntohs(uh->uh_sport));
352 		}
353 		udpstat.udps_noport++;
354 		if (m->m_flags & M_MCAST) {
355 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
356 			udpstat.udps_noportmcast++;
357 			goto bad;
358 		}
359 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
360 		return IPPROTO_DONE;
361 	}
362 #ifdef IPSEC
363 	/*
364 	 * Check AH/ESP integrity.
365 	 */
366 	if (ipsec6_in_reject_so(m, in6p->in6p_socket)) {
367 		ipsec6stat.in_polvio++;
368 		goto bad;
369 	}
370 #endif /*IPSEC*/
371 
372 	/*
373 	 * Construct sockaddr format source address.
374 	 * Stuff source address and datagram in user buffer.
375 	 */
376 	init_sin6(&udp_in6, m); /* general init */
377 	udp_in6.sin6_port = uh->uh_sport;
378 	if (in6p->in6p_flags & IN6P_CONTROLOPTS
379 	    || in6p->in6p_socket->so_options & SO_TIMESTAMP)
380 		ip6_savecontrol(in6p, &opts, ip6, m);
381 	m_adj(m, off + sizeof(struct udphdr));
382 	if (sbappendaddr(&in6p->in6p_socket->so_rcv,
383 			(struct sockaddr *)&udp_in6,
384 			m, opts) == 0) {
385 		udpstat.udps_fullsock++;
386 		goto bad;
387 	}
388 	sorwakeup(in6p->in6p_socket);
389 	return IPPROTO_DONE;
390 bad:
391 	if (m)
392 		m_freem(m);
393 	if (opts)
394 		m_freem(opts);
395 	return IPPROTO_DONE;
396 }
397 
398 void
399 udp6_ctlinput(cmd, sa, d)
400 	int cmd;
401 	struct sockaddr *sa;
402 	void *d;
403 {
404 	register struct udphdr *uhp;
405 	struct udphdr uh;
406 	struct sockaddr_in6 sa6;
407 	struct ip6_hdr *ip6;
408 	struct mbuf *m;
409 	int off = 0;
410 	void (*notify) __P((struct inpcb *, int)) = udp_notify;
411 
412 	if (sa->sa_family != AF_INET6 ||
413 	    sa->sa_len != sizeof(struct sockaddr_in6))
414 		return;
415 
416 	if ((unsigned)cmd >= PRC_NCMDS)
417 		return;
418 	if (PRC_IS_REDIRECT(cmd))
419 		notify = in6_rtchange, d = NULL;
420 	else if (cmd == PRC_HOSTDEAD)
421 		d = NULL;
422 	else if (inet6ctlerrmap[cmd] == 0)
423 		return;
424 
425 	/* if the parameter is from icmp6, decode it. */
426 	if (d != NULL) {
427 		struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d;
428 		m = ip6cp->ip6c_m;
429 		ip6 = ip6cp->ip6c_ip6;
430 		off = ip6cp->ip6c_off;
431 	} else {
432 		m = NULL;
433 		ip6 = NULL;
434 	}
435 
436 	/* translate addresses into internal form */
437 	sa6 = *(struct sockaddr_in6 *)sa;
438 	if (IN6_IS_ADDR_LINKLOCAL(&sa6.sin6_addr) && m && m->m_pkthdr.rcvif)
439 		sa6.sin6_addr.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
440 
441 	if (ip6) {
442 		/*
443 		 * XXX: We assume that when IPV6 is non NULL,
444 		 * M and OFF are valid.
445 		 */
446 		struct in6_addr s;
447 
448 		/* translate addresses into internal form */
449 		memcpy(&s, &ip6->ip6_src, sizeof(s));
450 		if (IN6_IS_ADDR_LINKLOCAL(&s))
451 			s.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
452 
453 		/* check if we can safely examine src and dst ports */
454 		if (m->m_pkthdr.len < off + sizeof(uh))
455 			return;
456 
457 		if (m->m_len < off + sizeof(uh)) {
458 			/*
459 			 * this should be rare case,
460 			 * so we compromise on this copy...
461 			 */
462 			m_copydata(m, off, sizeof(uh), (caddr_t)&uh);
463 			uhp = &uh;
464 		} else
465 			uhp = (struct udphdr *)(mtod(m, caddr_t) + off);
466 		(void) in6_pcbnotify(&udb, (struct sockaddr *)&sa6,
467 				     uhp->uh_dport, &s,
468 				     uhp->uh_sport, cmd, notify);
469 	} else
470 		(void) in6_pcbnotify(&udb, (struct sockaddr *)&sa6, 0,
471 				     &zeroin6_addr, 0, cmd, notify);
472 }
473 
474 static int
475 udp6_getcred(SYSCTL_HANDLER_ARGS)
476 {
477 	struct sockaddr_in6 addrs[2];
478 	struct inpcb *inp;
479 	int error, s;
480 
481 	error = suser(req->p);
482 	if (error)
483 		return (error);
484 
485 	if (req->newlen != sizeof(addrs))
486 		return (EINVAL);
487 	if (req->oldlen != sizeof(struct ucred))
488 		return (EINVAL);
489 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
490 	if (error)
491 		return (error);
492 	s = splnet();
493 	inp = in6_pcblookup_hash(&udbinfo, &addrs[1].sin6_addr,
494 				 addrs[1].sin6_port,
495 				 &addrs[0].sin6_addr, addrs[0].sin6_port,
496 				 1, NULL);
497 	if (!inp || !inp->inp_socket) {
498 		error = ENOENT;
499 		goto out;
500 	}
501 	error = SYSCTL_OUT(req, inp->inp_socket->so_cred,
502 			   sizeof(struct ucred));
503 
504 out:
505 	splx(s);
506 	return (error);
507 }
508 
509 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
510 	    0, 0,
511 	    udp6_getcred, "S,ucred", "Get the ucred of a UDP6 connection");
512 
513 static int
514 udp6_abort(struct socket *so)
515 {
516 	struct inpcb *inp;
517 	int s;
518 
519 	inp = sotoinpcb(so);
520 	if (inp == 0)
521 		return EINVAL;	/* ??? possible? panic instead? */
522 	soisdisconnected(so);
523 	s = splnet();
524 	in6_pcbdetach(inp);
525 	splx(s);
526 	return 0;
527 }
528 
529 static int
530 udp6_attach(struct socket *so, int proto, struct proc *p)
531 {
532 	struct inpcb *inp;
533 	int s, error;
534 
535 	inp = sotoinpcb(so);
536 	if (inp != 0)
537 		return EINVAL;
538 
539 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
540 		error = soreserve(so, udp_sendspace, udp_recvspace);
541 		if (error)
542 			return error;
543 	}
544 	s = splnet();
545 	error = in_pcballoc(so, &udbinfo, p);
546 	splx(s);
547 	if (error)
548 		return error;
549 	inp = (struct inpcb *)so->so_pcb;
550 	inp->inp_vflag |= INP_IPV6;
551 	inp->in6p_hops = -1;	/* use kernel default */
552 	inp->in6p_cksum = -1;	/* just to be sure */
553 	/*
554 	 * XXX: ugly!!
555 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
556 	 * because the socket may be bound to an IPv6 wildcard address,
557 	 * which may match an IPv4-mapped IPv6 address.
558 	 */
559 	inp->inp_ip_ttl = ip_defttl;
560 #ifdef IPSEC
561 	error = ipsec_init_policy(so, &inp->in6p_sp);
562 	if (error != 0) {
563 		in6_pcbdetach(inp);
564 		return (error);
565 	}
566 #endif /*IPSEC*/
567 	return 0;
568 }
569 
570 static int
571 udp6_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
572 {
573 	struct inpcb *inp;
574 	int s, error;
575 
576 	inp = sotoinpcb(so);
577 	if (inp == 0)
578 		return EINVAL;
579 
580 	inp->inp_vflag &= ~INP_IPV4;
581 	inp->inp_vflag |= INP_IPV6;
582 	if ((inp->inp_flags & IN6P_BINDV6ONLY) == 0) {
583 		struct sockaddr_in6 *sin6_p;
584 
585 		sin6_p = (struct sockaddr_in6 *)nam;
586 
587 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
588 			inp->inp_vflag |= INP_IPV4;
589 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
590 			struct sockaddr_in sin;
591 
592 			in6_sin6_2_sin(&sin, sin6_p);
593 			inp->inp_vflag |= INP_IPV4;
594 			inp->inp_vflag &= ~INP_IPV6;
595 			s = splnet();
596 			error = in_pcbbind(inp, (struct sockaddr *)&sin, p);
597 			splx(s);
598 			return error;
599 		}
600 	}
601 
602 	s = splnet();
603 	error = in6_pcbbind(inp, nam, p);
604 	splx(s);
605 	return error;
606 }
607 
608 static int
609 udp6_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
610 {
611 	struct inpcb *inp;
612 	int s, error;
613 
614 	inp = sotoinpcb(so);
615 	if (inp == 0)
616 		return EINVAL;
617 	if ((inp->inp_flags & IN6P_BINDV6ONLY) == 0) {
618 		struct sockaddr_in6 *sin6_p;
619 
620 		sin6_p = (struct sockaddr_in6 *)nam;
621 		if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
622 			struct sockaddr_in sin;
623 
624 			if (inp->inp_faddr.s_addr != INADDR_ANY)
625 				return EISCONN;
626 			in6_sin6_2_sin(&sin, sin6_p);
627 			s = splnet();
628 			error = in_pcbconnect(inp, (struct sockaddr *)&sin, p);
629 			splx(s);
630 			if (error == 0) {
631 				inp->inp_vflag |= INP_IPV4;
632 				inp->inp_vflag &= ~INP_IPV6;
633 				soisconnected(so);
634 			}
635 			return error;
636 		}
637 	}
638 
639 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
640 		return EISCONN;
641 	s = splnet();
642 	error = in6_pcbconnect(inp, nam, p);
643 	if (ip6_auto_flowlabel) {
644 		inp->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
645 		inp->in6p_flowinfo |=
646 			(htonl(ip6_flow_seq++) & IPV6_FLOWLABEL_MASK);
647 	}
648 	splx(s);
649 	if (error == 0) {
650 		inp->inp_vflag &= ~INP_IPV4;
651 		inp->inp_vflag |= INP_IPV6;
652 		soisconnected(so);
653 	}
654 	return error;
655 }
656 
657 static int
658 udp6_detach(struct socket *so)
659 {
660 	struct inpcb *inp;
661 	int s;
662 
663 	inp = sotoinpcb(so);
664 	if (inp == 0)
665 		return EINVAL;
666 	s = splnet();
667 	in6_pcbdetach(inp);
668 	splx(s);
669 	return 0;
670 }
671 
672 static int
673 udp6_disconnect(struct socket *so)
674 {
675 	struct inpcb *inp;
676 	int s;
677 
678 	inp = sotoinpcb(so);
679 	if (inp == 0)
680 		return EINVAL;
681 
682 	if (inp->inp_vflag & INP_IPV4) {
683 		struct pr_usrreqs *pru;
684 
685 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
686 		return ((*pru->pru_disconnect)(so));
687 	}
688 
689 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
690 		return ENOTCONN;
691 
692 	s = splnet();
693 	in6_pcbdisconnect(inp);
694 	inp->in6p_laddr = in6addr_any;
695 	splx(s);
696 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
697 	return 0;
698 }
699 
700 static int
701 udp6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
702 	  struct mbuf *control, struct proc *p)
703 {
704 	struct inpcb *inp;
705 	int error = 0;
706 
707 	inp = sotoinpcb(so);
708 	if (inp == 0) {
709 		error = EINVAL;
710 		goto bad;
711 	}
712 
713 	if (addr) {
714 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
715 			error = EINVAL;
716 			goto bad;
717 		}
718 		if (addr->sa_family != AF_INET6) {
719 			error = EAFNOSUPPORT;
720 			goto bad;
721 		}
722 	}
723 
724 	if (ip6_mapped_addr_on) {
725 		int hasv4addr;
726 		struct sockaddr_in6 *sin6 = 0;
727 
728 		if (addr == 0)
729 			hasv4addr = (inp->inp_vflag & INP_IPV4);
730 		else {
731 			sin6 = (struct sockaddr_in6 *)addr;
732 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
733 				? 1 : 0;
734 		}
735 		if (hasv4addr) {
736 			struct pr_usrreqs *pru;
737 
738 			if (sin6)
739 				in6_sin6_2_sin_in_sock(addr);
740 			pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
741 			error = ((*pru->pru_send)(so, flags, m, addr, control,
742 						  p));
743 			/* addr will just be freed in sendit(). */
744 			return error;
745 		}
746 	}
747 
748 	return udp6_output(inp, m, addr, control, p);
749 
750   bad:
751 	m_freem(m);
752 	return(error);
753 }
754 
755 struct pr_usrreqs udp6_usrreqs = {
756 	udp6_abort, pru_accept_notsupp, udp6_attach, udp6_bind, udp6_connect,
757 	pru_connect2_notsupp, in6_control, udp6_detach, udp6_disconnect,
758 	pru_listen_notsupp, in6_mapped_peeraddr, pru_rcvd_notsupp,
759 	pru_rcvoob_notsupp, udp6_send, pru_sense_null, udp_shutdown,
760 	in6_mapped_sockaddr, sosend, soreceive, sopoll
761 };
762