xref: /dragonfly/sys/netinet6/udp6_usrreq.c (revision 984263bc)
1 /*	$FreeBSD: src/sys/netinet6/udp6_usrreq.c,v 1.6.2.13 2003/01/24 05:11:35 sam Exp $	*/
2 /*	$KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei 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 #ifdef FAST_IPSEC
110 #include <netipsec/ipsec.h>
111 #include <netipsec/ipsec6.h>
112 #endif /* FAST_IPSEC */
113 
114 /*
115  * UDP protocol inplementation.
116  * Per RFC 768, August, 1980.
117  */
118 
119 extern	struct protosw inetsw[];
120 static	int in6_mcmatch __P((struct inpcb *, struct in6_addr *, struct ifnet *));
121 static	int udp6_detach __P((struct socket *so));
122 
123 static int
124 in6_mcmatch(in6p, ia6, ifp)
125 	struct inpcb *in6p;
126 	register struct in6_addr *ia6;
127 	struct ifnet *ifp;
128 {
129 	struct ip6_moptions *im6o = in6p->in6p_moptions;
130 	struct in6_multi_mship *imm;
131 
132 	if (im6o == NULL)
133 		return 0;
134 
135 	for (imm = im6o->im6o_memberships.lh_first; imm != NULL;
136 	     imm = imm->i6mm_chain.le_next) {
137 		if ((ifp == NULL ||
138 		     imm->i6mm_maddr->in6m_ifp == ifp) &&
139 		    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
140 				       ia6))
141 			return 1;
142 	}
143 	return 0;
144 }
145 
146 int
147 udp6_input(mp, offp, proto)
148 	struct mbuf **mp;
149 	int *offp, proto;
150 {
151 	struct mbuf *m = *mp;
152 	register struct ip6_hdr *ip6;
153 	register struct udphdr *uh;
154 	register struct inpcb *in6p;
155 	struct  mbuf *opts = NULL;
156 	int off = *offp;
157 	int plen, ulen;
158 	struct sockaddr_in6 udp_in6;
159 
160 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
161 
162 	ip6 = mtod(m, struct ip6_hdr *);
163 
164 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
165 		/* XXX send icmp6 host/port unreach? */
166 		m_freem(m);
167 		return IPPROTO_DONE;
168 	}
169 
170 	udpstat.udps_ipackets++;
171 
172 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
173 	uh = (struct udphdr *)((caddr_t)ip6 + off);
174 	ulen = ntohs((u_short)uh->uh_ulen);
175 
176 	if (plen != ulen) {
177 		udpstat.udps_badlen++;
178 		goto bad;
179 	}
180 
181 	/*
182 	 * Checksum extended UDP header and data.
183 	 */
184 	if (uh->uh_sum == 0)
185 		udpstat.udps_nosum++;
186 	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
187 		udpstat.udps_badsum++;
188 		goto bad;
189 	}
190 
191 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
192 		struct	inpcb *last;
193 
194 		/*
195 		 * Deliver a multicast datagram to all sockets
196 		 * for which the local and remote addresses and ports match
197 		 * those of the incoming datagram.  This allows more than
198 		 * one process to receive multicasts on the same port.
199 		 * (This really ought to be done for unicast datagrams as
200 		 * well, but that would cause problems with existing
201 		 * applications that open both address-specific sockets and
202 		 * a wildcard socket listening to the same port -- they would
203 		 * end up receiving duplicates of every unicast datagram.
204 		 * Those applications open the multiple sockets to overcome an
205 		 * inadequacy of the UDP socket interface, but for backwards
206 		 * compatibility we avoid the problem here rather than
207 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
208 		 */
209 
210 		/*
211 		 * In a case that laddr should be set to the link-local
212 		 * address (this happens in RIPng), the multicast address
213 		 * specified in the received packet does not match with
214 		 * laddr. To cure this situation, the matching is relaxed
215 		 * if the receiving interface is the same as one specified
216 		 * in the socket and if the destination multicast address
217 		 * matches one of the multicast groups specified in the socket.
218 		 */
219 
220 		/*
221 		 * Construct sockaddr format source address.
222 		 */
223 		init_sin6(&udp_in6, m); /* general init */
224 		udp_in6.sin6_port = uh->uh_sport;
225 		/*
226 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
227 		 * We need udphdr for IPsec processing so we do that later.
228 		 */
229 
230 		/*
231 		 * Locate pcb(s) for datagram.
232 		 * (Algorithm copied from raw_intr().)
233 		 */
234 		last = NULL;
235 		LIST_FOREACH(in6p, &udb, inp_list) {
236 			if ((in6p->inp_vflag & INP_IPV6) == 0)
237 				continue;
238 			if (in6p->in6p_lport != uh->uh_dport)
239 				continue;
240 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
241 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
242 							&ip6->ip6_dst) &&
243 				    !in6_mcmatch(in6p, &ip6->ip6_dst,
244 						 m->m_pkthdr.rcvif))
245 					continue;
246 			}
247 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
248 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
249 							&ip6->ip6_src) ||
250 				   in6p->in6p_fport != uh->uh_sport)
251 					continue;
252 			}
253 
254 			if (last != NULL) {
255 				struct	mbuf *n;
256 
257 #ifdef IPSEC
258 				/*
259 				 * Check AH/ESP integrity.
260 				 */
261 				if (ipsec6_in_reject_so(m, last->inp_socket))
262 					ipsec6stat.in_polvio++;
263 					/* do not inject data into pcb */
264 				else
265 #endif /* IPSEC */
266 #ifdef FAST_IPSEC
267 				/*
268 				 * Check AH/ESP integrity.
269 				 */
270 				if (ipsec6_in_reject(m, last))
271 					;
272 				else
273 #endif /* FAST_IPSEC */
274 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
275 					/*
276 					 * KAME NOTE: do not
277 					 * m_copy(m, offset, ...) above.
278 					 * sbappendaddr() expects M_PKTHDR,
279 					 * and m_copy() will copy M_PKTHDR
280 					 * only if offset is 0.
281 					 */
282 					if (last->in6p_flags & IN6P_CONTROLOPTS
283 					    || last->in6p_socket->so_options & SO_TIMESTAMP)
284 						ip6_savecontrol(last, &opts,
285 								ip6, n);
286 
287 					m_adj(n, off + sizeof(struct udphdr));
288 					if (sbappendaddr(&last->in6p_socket->so_rcv,
289 							(struct sockaddr *)&udp_in6,
290 							n, opts) == 0) {
291 						m_freem(n);
292 						if (opts)
293 							m_freem(opts);
294 						udpstat.udps_fullsock++;
295 					} else
296 						sorwakeup(last->in6p_socket);
297 					opts = NULL;
298 				}
299 			}
300 			last = in6p;
301 			/*
302 			 * Don't look for additional matches if this one does
303 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
304 			 * socket options set.  This heuristic avoids searching
305 			 * through all pcbs in the common case of a non-shared
306 			 * port.  It assumes that an application will never
307 			 * clear these options after setting them.
308 			 */
309 			if ((last->in6p_socket->so_options &
310 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
311 				break;
312 		}
313 
314 		if (last == NULL) {
315 			/*
316 			 * No matching pcb found; discard datagram.
317 			 * (No need to send an ICMP Port Unreachable
318 			 * for a broadcast or multicast datgram.)
319 			 */
320 			udpstat.udps_noport++;
321 			udpstat.udps_noportmcast++;
322 			goto bad;
323 		}
324 #ifdef IPSEC
325 		/*
326 		 * Check AH/ESP integrity.
327 		 */
328 		if (ipsec6_in_reject_so(m, last->inp_socket)) {
329 			ipsec6stat.in_polvio++;
330 			goto bad;
331 		}
332 #endif /* IPSEC */
333 #ifdef FAST_IPSEC
334 		/*
335 		 * Check AH/ESP integrity.
336 		 */
337 		if (ipsec6_in_reject(m, last)) {
338 			goto bad;
339 		}
340 #endif /* FAST_IPSEC */
341 		if (last->in6p_flags & IN6P_CONTROLOPTS
342 		    || last->in6p_socket->so_options & SO_TIMESTAMP)
343 			ip6_savecontrol(last, &opts, ip6, m);
344 
345 		m_adj(m, off + sizeof(struct udphdr));
346 		if (sbappendaddr(&last->in6p_socket->so_rcv,
347 				(struct sockaddr *)&udp_in6,
348 				m, opts) == 0) {
349 			udpstat.udps_fullsock++;
350 			goto bad;
351 		}
352 		sorwakeup(last->in6p_socket);
353 		return IPPROTO_DONE;
354 	}
355 	/*
356 	 * Locate pcb for datagram.
357 	 */
358 	in6p = in6_pcblookup_hash(&udbinfo, &ip6->ip6_src, uh->uh_sport,
359 				  &ip6->ip6_dst, uh->uh_dport, 1,
360 				  m->m_pkthdr.rcvif);
361 	if (in6p == 0) {
362 		if (log_in_vain) {
363 			char buf[INET6_ADDRSTRLEN];
364 
365 			strcpy(buf, ip6_sprintf(&ip6->ip6_dst));
366 			log(LOG_INFO,
367 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
368 			    buf, ntohs(uh->uh_dport),
369 			    ip6_sprintf(&ip6->ip6_src), ntohs(uh->uh_sport));
370 		}
371 		udpstat.udps_noport++;
372 		if (m->m_flags & M_MCAST) {
373 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
374 			udpstat.udps_noportmcast++;
375 			goto bad;
376 		}
377 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
378 		return IPPROTO_DONE;
379 	}
380 #ifdef IPSEC
381 	/*
382 	 * Check AH/ESP integrity.
383 	 */
384 	if (ipsec6_in_reject_so(m, in6p->in6p_socket)) {
385 		ipsec6stat.in_polvio++;
386 		goto bad;
387 	}
388 #endif /* IPSEC */
389 #ifdef FAST_IPSEC
390 	/*
391 	 * Check AH/ESP integrity.
392 	 */
393 	if (ipsec6_in_reject(m, in6p)) {
394 		goto bad;
395 	}
396 #endif /* FAST_IPSEC */
397 
398 	/*
399 	 * Construct sockaddr format source address.
400 	 * Stuff source address and datagram in user buffer.
401 	 */
402 	init_sin6(&udp_in6, m); /* general init */
403 	udp_in6.sin6_port = uh->uh_sport;
404 	if (in6p->in6p_flags & IN6P_CONTROLOPTS
405 	    || in6p->in6p_socket->so_options & SO_TIMESTAMP)
406 		ip6_savecontrol(in6p, &opts, ip6, m);
407 	m_adj(m, off + sizeof(struct udphdr));
408 	if (sbappendaddr(&in6p->in6p_socket->so_rcv,
409 			(struct sockaddr *)&udp_in6,
410 			m, opts) == 0) {
411 		udpstat.udps_fullsock++;
412 		goto bad;
413 	}
414 	sorwakeup(in6p->in6p_socket);
415 	return IPPROTO_DONE;
416 bad:
417 	if (m)
418 		m_freem(m);
419 	if (opts)
420 		m_freem(opts);
421 	return IPPROTO_DONE;
422 }
423 
424 void
425 udp6_ctlinput(cmd, sa, d)
426 	int cmd;
427 	struct sockaddr *sa;
428 	void *d;
429 {
430 	struct udphdr uh;
431 	struct ip6_hdr *ip6;
432 	struct mbuf *m;
433 	int off = 0;
434 	struct ip6ctlparam *ip6cp = NULL;
435 	const struct sockaddr_in6 *sa6_src = NULL;
436 	void (*notify) __P((struct inpcb *, int)) = udp_notify;
437 	struct udp_portonly {
438 		u_int16_t uh_sport;
439 		u_int16_t uh_dport;
440 	} *uhp;
441 
442 	if (sa->sa_family != AF_INET6 ||
443 	    sa->sa_len != sizeof(struct sockaddr_in6))
444 		return;
445 
446 	if ((unsigned)cmd >= PRC_NCMDS)
447 		return;
448 	if (PRC_IS_REDIRECT(cmd))
449 		notify = in6_rtchange, d = NULL;
450 	else if (cmd == PRC_HOSTDEAD)
451 		d = NULL;
452 	else if (inet6ctlerrmap[cmd] == 0)
453 		return;
454 
455 	/* if the parameter is from icmp6, decode it. */
456 	if (d != NULL) {
457 		ip6cp = (struct ip6ctlparam *)d;
458 		m = ip6cp->ip6c_m;
459 		ip6 = ip6cp->ip6c_ip6;
460 		off = ip6cp->ip6c_off;
461 		sa6_src = ip6cp->ip6c_src;
462 	} else {
463 		m = NULL;
464 		ip6 = NULL;
465 		sa6_src = &sa6_any;
466 	}
467 
468 	if (ip6) {
469 		/*
470 		 * XXX: We assume that when IPV6 is non NULL,
471 		 * M and OFF are valid.
472 		 */
473 
474 		/* check if we can safely examine src and dst ports */
475 		if (m->m_pkthdr.len < off + sizeof(*uhp))
476 			return;
477 
478 		bzero(&uh, sizeof(uh));
479 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
480 
481 		(void) in6_pcbnotify(&udb, sa, uh.uh_dport,
482 				     (struct sockaddr *)ip6cp->ip6c_src,
483 				     uh.uh_sport, cmd, notify);
484 	} else
485 		(void) in6_pcbnotify(&udb, sa, 0, (struct sockaddr *)sa6_src,
486 				     0, cmd, notify);
487 }
488 
489 static int
490 udp6_getcred(SYSCTL_HANDLER_ARGS)
491 {
492 	struct sockaddr_in6 addrs[2];
493 	struct inpcb *inp;
494 	int error, s;
495 
496 	error = suser(req->p);
497 	if (error)
498 		return (error);
499 
500 	if (req->newlen != sizeof(addrs))
501 		return (EINVAL);
502 	if (req->oldlen != sizeof(struct ucred))
503 		return (EINVAL);
504 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
505 	if (error)
506 		return (error);
507 	s = splnet();
508 	inp = in6_pcblookup_hash(&udbinfo, &addrs[1].sin6_addr,
509 				 addrs[1].sin6_port,
510 				 &addrs[0].sin6_addr, addrs[0].sin6_port,
511 				 1, NULL);
512 	if (!inp || !inp->inp_socket) {
513 		error = ENOENT;
514 		goto out;
515 	}
516 	error = SYSCTL_OUT(req, inp->inp_socket->so_cred,
517 			   sizeof(struct ucred));
518 
519 out:
520 	splx(s);
521 	return (error);
522 }
523 
524 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
525 	    0, 0,
526 	    udp6_getcred, "S,ucred", "Get the ucred of a UDP6 connection");
527 
528 static int
529 udp6_abort(struct socket *so)
530 {
531 	struct inpcb *inp;
532 	int s;
533 
534 	inp = sotoinpcb(so);
535 	if (inp == 0)
536 		return EINVAL;	/* ??? possible? panic instead? */
537 	soisdisconnected(so);
538 	s = splnet();
539 	in6_pcbdetach(inp);
540 	splx(s);
541 	return 0;
542 }
543 
544 static int
545 udp6_attach(struct socket *so, int proto, struct proc *p)
546 {
547 	struct inpcb *inp;
548 	int s, error;
549 
550 	inp = sotoinpcb(so);
551 	if (inp != 0)
552 		return EINVAL;
553 
554 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
555 		error = soreserve(so, udp_sendspace, udp_recvspace);
556 		if (error)
557 			return error;
558 	}
559 	s = splnet();
560 	error = in_pcballoc(so, &udbinfo, p);
561 	splx(s);
562 	if (error)
563 		return error;
564 	inp = (struct inpcb *)so->so_pcb;
565 	inp->inp_vflag |= INP_IPV6;
566 	if (!ip6_v6only)
567 		inp->inp_vflag |= INP_IPV4;
568 	inp->in6p_hops = -1;	/* use kernel default */
569 	inp->in6p_cksum = -1;	/* just to be sure */
570 	/*
571 	 * XXX: ugly!!
572 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
573 	 * because the socket may be bound to an IPv6 wildcard address,
574 	 * which may match an IPv4-mapped IPv6 address.
575 	 */
576 	inp->inp_ip_ttl = ip_defttl;
577 	return 0;
578 }
579 
580 static int
581 udp6_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
582 {
583 	struct inpcb *inp;
584 	int s, error;
585 
586 	inp = sotoinpcb(so);
587 	if (inp == 0)
588 		return EINVAL;
589 
590 	inp->inp_vflag &= ~INP_IPV4;
591 	inp->inp_vflag |= INP_IPV6;
592 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
593 		struct sockaddr_in6 *sin6_p;
594 
595 		sin6_p = (struct sockaddr_in6 *)nam;
596 
597 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
598 			inp->inp_vflag |= INP_IPV4;
599 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
600 			struct sockaddr_in sin;
601 
602 			in6_sin6_2_sin(&sin, sin6_p);
603 			inp->inp_vflag |= INP_IPV4;
604 			inp->inp_vflag &= ~INP_IPV6;
605 			s = splnet();
606 			error = in_pcbbind(inp, (struct sockaddr *)&sin, p);
607 			splx(s);
608 			return error;
609 		}
610 	}
611 
612 	s = splnet();
613 	error = in6_pcbbind(inp, nam, p);
614 	splx(s);
615 	return error;
616 }
617 
618 static int
619 udp6_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
620 {
621 	struct inpcb *inp;
622 	int s, error;
623 
624 	inp = sotoinpcb(so);
625 	if (inp == 0)
626 		return EINVAL;
627 
628 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
629 		struct sockaddr_in6 *sin6_p;
630 
631 		sin6_p = (struct sockaddr_in6 *)nam;
632 		if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
633 			struct sockaddr_in sin;
634 
635 			if (inp->inp_faddr.s_addr != INADDR_ANY)
636 				return EISCONN;
637 			in6_sin6_2_sin(&sin, sin6_p);
638 			s = splnet();
639 			error = in_pcbconnect(inp, (struct sockaddr *)&sin, p);
640 			splx(s);
641 			if (error == 0) {
642 				inp->inp_vflag |= INP_IPV4;
643 				inp->inp_vflag &= ~INP_IPV6;
644 				soisconnected(so);
645 			}
646 			return error;
647 		}
648 	}
649 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
650 		return EISCONN;
651 	s = splnet();
652 	error = in6_pcbconnect(inp, nam, p);
653 	splx(s);
654 	if (error == 0) {
655 		if (!ip6_v6only) { /* should be non mapped addr */
656 			inp->inp_vflag &= ~INP_IPV4;
657 			inp->inp_vflag |= INP_IPV6;
658 		}
659 		soisconnected(so);
660 	}
661 	return error;
662 }
663 
664 static int
665 udp6_detach(struct socket *so)
666 {
667 	struct inpcb *inp;
668 	int s;
669 
670 	inp = sotoinpcb(so);
671 	if (inp == 0)
672 		return EINVAL;
673 	s = splnet();
674 	in6_pcbdetach(inp);
675 	splx(s);
676 	return 0;
677 }
678 
679 static int
680 udp6_disconnect(struct socket *so)
681 {
682 	struct inpcb *inp;
683 	int s;
684 
685 	inp = sotoinpcb(so);
686 	if (inp == 0)
687 		return EINVAL;
688 
689 	if (inp->inp_vflag & INP_IPV4) {
690 		struct pr_usrreqs *pru;
691 
692 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
693 		return ((*pru->pru_disconnect)(so));
694 	}
695 
696 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
697 		return ENOTCONN;
698 
699 	s = splnet();
700 	in6_pcbdisconnect(inp);
701 	inp->in6p_laddr = in6addr_any;
702 	splx(s);
703 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
704 	return 0;
705 }
706 
707 static int
708 udp6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
709 	  struct mbuf *control, struct proc *p)
710 {
711 	struct inpcb *inp;
712 	int error = 0;
713 
714 	inp = sotoinpcb(so);
715 	if (inp == 0) {
716 		error = EINVAL;
717 		goto bad;
718 	}
719 
720 	if (addr) {
721 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
722 			error = EINVAL;
723 			goto bad;
724 		}
725 		if (addr->sa_family != AF_INET6) {
726 			error = EAFNOSUPPORT;
727 			goto bad;
728 		}
729 	}
730 
731 	if (!ip6_v6only) {
732 		int hasv4addr;
733 		struct sockaddr_in6 *sin6 = 0;
734 
735 		if (addr == 0)
736 			hasv4addr = (inp->inp_vflag & INP_IPV4);
737 		else {
738 			sin6 = (struct sockaddr_in6 *)addr;
739 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
740 				? 1 : 0;
741 		}
742 		if (hasv4addr) {
743 			struct pr_usrreqs *pru;
744 
745 			if (sin6)
746 				in6_sin6_2_sin_in_sock(addr);
747 			pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
748 			error = ((*pru->pru_send)(so, flags, m, addr, control,
749 						  p));
750 			/* addr will just be freed in sendit(). */
751 			return error;
752 		}
753 	}
754 
755 	return udp6_output(inp, m, addr, control, p);
756 
757   bad:
758 	m_freem(m);
759 	return(error);
760 }
761 
762 struct pr_usrreqs udp6_usrreqs = {
763 	udp6_abort, pru_accept_notsupp, udp6_attach, udp6_bind, udp6_connect,
764 	pru_connect2_notsupp, in6_control, udp6_detach, udp6_disconnect,
765 	pru_listen_notsupp, in6_mapped_peeraddr, pru_rcvd_notsupp,
766 	pru_rcvoob_notsupp, udp6_send, pru_sense_null, udp_shutdown,
767 	in6_mapped_sockaddr, sosend, soreceive, sopoll
768 };
769