xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
1 /*	$FreeBSD$	*/
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/errno.h>
74 #include <sys/kernel.h>
75 #include <sys/lock.h>
76 #include <sys/mbuf.h>
77 #include <sys/proc.h>
78 #include <sys/protosw.h>
79 #include <sys/signalvar.h>
80 #include <sys/socket.h>
81 #include <sys/socketvar.h>
82 #include <sys/stat.h>
83 #include <sys/sx.h>
84 #include <sys/sysctl.h>
85 #include <sys/syslog.h>
86 #include <sys/systm.h>
87 
88 #include <net/if.h>
89 #include <net/if_types.h>
90 #include <net/route.h>
91 
92 #include <netinet/in.h>
93 #include <netinet/in_pcb.h>
94 #include <netinet/in_systm.h>
95 #include <netinet/in_var.h>
96 #include <netinet/ip.h>
97 #include <netinet/ip6.h>
98 #include <netinet/icmp6.h>
99 #include <netinet/ip_var.h>
100 #include <netinet/udp.h>
101 #include <netinet/udp_var.h>
102 #include <netinet6/ip6protosw.h>
103 #include <netinet6/ip6_var.h>
104 #include <netinet6/in6_pcb.h>
105 #include <netinet6/udp6_var.h>
106 
107 #ifdef IPSEC
108 #include <netinet6/ipsec.h>
109 #include <netinet6/ipsec6.h>
110 #endif /* IPSEC */
111 
112 #ifdef FAST_IPSEC
113 #include <netipsec/ipsec.h>
114 #include <netipsec/ipsec6.h>
115 #endif /* FAST_IPSEC */
116 
117 /*
118  * UDP protocol inplementation.
119  * Per RFC 768, August, 1980.
120  */
121 
122 extern	struct protosw inetsw[];
123 static	int in6_mcmatch __P((struct inpcb *, struct in6_addr *, struct ifnet *));
124 static	int udp6_detach __P((struct socket *so));
125 
126 static int
127 in6_mcmatch(in6p, ia6, ifp)
128 	struct inpcb *in6p;
129 	register struct in6_addr *ia6;
130 	struct ifnet *ifp;
131 {
132 	struct ip6_moptions *im6o = in6p->in6p_moptions;
133 	struct in6_multi_mship *imm;
134 
135 	if (im6o == NULL)
136 		return 0;
137 
138 	for (imm = im6o->im6o_memberships.lh_first; imm != NULL;
139 	     imm = imm->i6mm_chain.le_next) {
140 		if ((ifp == NULL ||
141 		     imm->i6mm_maddr->in6m_ifp == ifp) &&
142 		    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
143 				       ia6))
144 			return 1;
145 	}
146 	return 0;
147 }
148 
149 int
150 udp6_input(mp, offp, proto)
151 	struct mbuf **mp;
152 	int *offp, proto;
153 {
154 	struct mbuf *m = *mp;
155 	register struct ip6_hdr *ip6;
156 	register struct udphdr *uh;
157 	register struct inpcb *in6p;
158 	struct  mbuf *opts = NULL;
159 	int off = *offp;
160 	int plen, ulen;
161 	struct sockaddr_in6 udp_in6;
162 
163 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
164 
165 	ip6 = mtod(m, struct ip6_hdr *);
166 
167 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
168 		/* XXX send icmp6 host/port unreach? */
169 		m_freem(m);
170 		return IPPROTO_DONE;
171 	}
172 
173 	udpstat.udps_ipackets++;
174 
175 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
176 	uh = (struct udphdr *)((caddr_t)ip6 + off);
177 	ulen = ntohs((u_short)uh->uh_ulen);
178 
179 	if (plen != ulen) {
180 		udpstat.udps_badlen++;
181 		goto bad;
182 	}
183 
184 	/*
185 	 * Checksum extended UDP header and data.
186 	 */
187 	if (uh->uh_sum == 0)
188 		udpstat.udps_nosum++;
189 	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
190 		udpstat.udps_badsum++;
191 		goto bad;
192 	}
193 
194 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
195 		struct	inpcb *last;
196 
197 		/*
198 		 * Deliver a multicast datagram to all sockets
199 		 * for which the local and remote addresses and ports match
200 		 * those of the incoming datagram.  This allows more than
201 		 * one process to receive multicasts on the same port.
202 		 * (This really ought to be done for unicast datagrams as
203 		 * well, but that would cause problems with existing
204 		 * applications that open both address-specific sockets and
205 		 * a wildcard socket listening to the same port -- they would
206 		 * end up receiving duplicates of every unicast datagram.
207 		 * Those applications open the multiple sockets to overcome an
208 		 * inadequacy of the UDP socket interface, but for backwards
209 		 * compatibility we avoid the problem here rather than
210 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
211 		 */
212 
213 		/*
214 		 * In a case that laddr should be set to the link-local
215 		 * address (this happens in RIPng), the multicast address
216 		 * specified in the received packet does not match with
217 		 * laddr. To cure this situation, the matching is relaxed
218 		 * if the receiving interface is the same as one specified
219 		 * in the socket and if the destination multicast address
220 		 * matches one of the multicast groups specified in the socket.
221 		 */
222 
223 		/*
224 		 * Construct sockaddr format source address.
225 		 */
226 		init_sin6(&udp_in6, m); /* general init */
227 		udp_in6.sin6_port = uh->uh_sport;
228 		/*
229 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
230 		 * We need udphdr for IPsec processing so we do that later.
231 		 */
232 
233 		/*
234 		 * Locate pcb(s) for datagram.
235 		 * (Algorithm copied from raw_intr().)
236 		 */
237 		last = NULL;
238 		LIST_FOREACH(in6p, &udb, inp_list) {
239 			if ((in6p->inp_vflag & INP_IPV6) == 0)
240 				continue;
241 			if (in6p->in6p_lport != uh->uh_dport)
242 				continue;
243 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
244 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
245 							&ip6->ip6_dst) &&
246 				    !in6_mcmatch(in6p, &ip6->ip6_dst,
247 						 m->m_pkthdr.rcvif))
248 					continue;
249 			}
250 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
251 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
252 							&ip6->ip6_src) ||
253 				   in6p->in6p_fport != uh->uh_sport)
254 					continue;
255 			}
256 
257 			if (last != NULL) {
258 				struct	mbuf *n;
259 
260 #ifdef IPSEC
261 				/*
262 				 * Check AH/ESP integrity.
263 				 */
264 				if (ipsec6_in_reject(m, last))
265 					ipsec6stat.in_polvio++;
266 					/* do not inject data into pcb */
267 				else
268 #endif /* IPSEC */
269 #ifdef FAST_IPSEC
270 				/*
271 				 * Check AH/ESP integrity.
272 				 */
273 				if (ipsec6_in_reject(m, last))
274 					;
275 				else
276 #endif /* FAST_IPSEC */
277 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
278 					/*
279 					 * KAME NOTE: do not
280 					 * m_copy(m, offset, ...) above.
281 					 * sbappendaddr() expects M_PKTHDR,
282 					 * and m_copy() will copy M_PKTHDR
283 					 * only if offset is 0.
284 					 */
285 					if (last->in6p_flags & IN6P_CONTROLOPTS
286 					    || last->in6p_socket->so_options & SO_TIMESTAMP)
287 						ip6_savecontrol(last, &opts,
288 								ip6, n);
289 
290 					m_adj(n, off + sizeof(struct udphdr));
291 					if (sbappendaddr(&last->in6p_socket->so_rcv,
292 							(struct sockaddr *)&udp_in6,
293 							n, opts) == 0) {
294 						m_freem(n);
295 						if (opts)
296 							m_freem(opts);
297 						udpstat.udps_fullsock++;
298 					} else
299 						sorwakeup(last->in6p_socket);
300 					opts = NULL;
301 				}
302 			}
303 			last = in6p;
304 			/*
305 			 * Don't look for additional matches if this one does
306 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
307 			 * socket options set.  This heuristic avoids searching
308 			 * through all pcbs in the common case of a non-shared
309 			 * port.  It assumes that an application will never
310 			 * clear these options after setting them.
311 			 */
312 			if ((last->in6p_socket->so_options &
313 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
314 				break;
315 		}
316 
317 		if (last == NULL) {
318 			/*
319 			 * No matching pcb found; discard datagram.
320 			 * (No need to send an ICMP Port Unreachable
321 			 * for a broadcast or multicast datgram.)
322 			 */
323 			udpstat.udps_noport++;
324 			udpstat.udps_noportmcast++;
325 			goto bad;
326 		}
327 #ifdef IPSEC
328 		/*
329 		 * Check AH/ESP integrity.
330 		 */
331 		if (ipsec6_in_reject(m, last)) {
332 			ipsec6stat.in_polvio++;
333 			goto bad;
334 		}
335 #endif /* IPSEC */
336 #ifdef FAST_IPSEC
337 		/*
338 		 * Check AH/ESP integrity.
339 		 */
340 		if (ipsec6_in_reject(m, last)) {
341 			goto bad;
342 		}
343 #endif /* FAST_IPSEC */
344 		if (last->in6p_flags & IN6P_CONTROLOPTS
345 		    || last->in6p_socket->so_options & SO_TIMESTAMP)
346 			ip6_savecontrol(last, &opts, ip6, m);
347 
348 		m_adj(m, off + sizeof(struct udphdr));
349 		if (sbappendaddr(&last->in6p_socket->so_rcv,
350 				(struct sockaddr *)&udp_in6,
351 				m, opts) == 0) {
352 			udpstat.udps_fullsock++;
353 			goto bad;
354 		}
355 		sorwakeup(last->in6p_socket);
356 		return IPPROTO_DONE;
357 	}
358 	/*
359 	 * Locate pcb for datagram.
360 	 */
361 	in6p = in6_pcblookup_hash(&udbinfo, &ip6->ip6_src, uh->uh_sport,
362 				  &ip6->ip6_dst, uh->uh_dport, 1,
363 				  m->m_pkthdr.rcvif);
364 	if (in6p == 0) {
365 		if (log_in_vain) {
366 			char buf[INET6_ADDRSTRLEN];
367 
368 			strcpy(buf, ip6_sprintf(&ip6->ip6_dst));
369 			log(LOG_INFO,
370 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
371 			    buf, ntohs(uh->uh_dport),
372 			    ip6_sprintf(&ip6->ip6_src), ntohs(uh->uh_sport));
373 		}
374 		udpstat.udps_noport++;
375 		if (m->m_flags & M_MCAST) {
376 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
377 			udpstat.udps_noportmcast++;
378 			goto bad;
379 		}
380 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
381 		return IPPROTO_DONE;
382 	}
383 #ifdef IPSEC
384 	/*
385 	 * Check AH/ESP integrity.
386 	 */
387 	if (ipsec6_in_reject(m, in6p)) {
388 		ipsec6stat.in_polvio++;
389 		goto bad;
390 	}
391 #endif /* IPSEC */
392 #ifdef FAST_IPSEC
393 	/*
394 	 * Check AH/ESP integrity.
395 	 */
396 	if (ipsec6_in_reject(m, in6p)) {
397 		goto bad;
398 	}
399 #endif /* FAST_IPSEC */
400 
401 	/*
402 	 * Construct sockaddr format source address.
403 	 * Stuff source address and datagram in user buffer.
404 	 */
405 	init_sin6(&udp_in6, m); /* general init */
406 	udp_in6.sin6_port = uh->uh_sport;
407 	if (in6p->in6p_flags & IN6P_CONTROLOPTS
408 	    || in6p->in6p_socket->so_options & SO_TIMESTAMP)
409 		ip6_savecontrol(in6p, &opts, ip6, m);
410 	m_adj(m, off + sizeof(struct udphdr));
411 	if (sbappendaddr(&in6p->in6p_socket->so_rcv,
412 			(struct sockaddr *)&udp_in6,
413 			m, opts) == 0) {
414 		udpstat.udps_fullsock++;
415 		goto bad;
416 	}
417 	sorwakeup(in6p->in6p_socket);
418 	return IPPROTO_DONE;
419 bad:
420 	if (m)
421 		m_freem(m);
422 	if (opts)
423 		m_freem(opts);
424 	return IPPROTO_DONE;
425 }
426 
427 void
428 udp6_ctlinput(cmd, sa, d)
429 	int cmd;
430 	struct sockaddr *sa;
431 	void *d;
432 {
433 	struct udphdr uh;
434 	struct ip6_hdr *ip6;
435 	struct mbuf *m;
436 	int off = 0;
437 	struct ip6ctlparam *ip6cp = NULL;
438 	const struct sockaddr_in6 *sa6_src = NULL;
439 	struct inpcb *(*notify) __P((struct inpcb *, int)) = udp_notify;
440 	struct udp_portonly {
441 		u_int16_t uh_sport;
442 		u_int16_t uh_dport;
443 	} *uhp;
444 
445 	if (sa->sa_family != AF_INET6 ||
446 	    sa->sa_len != sizeof(struct sockaddr_in6))
447 		return;
448 
449 	if ((unsigned)cmd >= PRC_NCMDS)
450 		return;
451 	if (PRC_IS_REDIRECT(cmd))
452 		notify = in6_rtchange, d = NULL;
453 	else if (cmd == PRC_HOSTDEAD)
454 		d = NULL;
455 	else if (inet6ctlerrmap[cmd] == 0)
456 		return;
457 
458 	/* if the parameter is from icmp6, decode it. */
459 	if (d != NULL) {
460 		ip6cp = (struct ip6ctlparam *)d;
461 		m = ip6cp->ip6c_m;
462 		ip6 = ip6cp->ip6c_ip6;
463 		off = ip6cp->ip6c_off;
464 		sa6_src = ip6cp->ip6c_src;
465 	} else {
466 		m = NULL;
467 		ip6 = NULL;
468 		sa6_src = &sa6_any;
469 	}
470 
471 	if (ip6) {
472 		/*
473 		 * XXX: We assume that when IPV6 is non NULL,
474 		 * M and OFF are valid.
475 		 */
476 
477 		/* check if we can safely examine src and dst ports */
478 		if (m->m_pkthdr.len < off + sizeof(*uhp))
479 			return;
480 
481 		bzero(&uh, sizeof(uh));
482 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
483 
484 		(void) in6_pcbnotify(&udb, sa, uh.uh_dport,
485 				     (struct sockaddr *)ip6cp->ip6c_src,
486 				     uh.uh_sport, cmd, notify);
487 	} else
488 		(void) in6_pcbnotify(&udb, sa, 0,
489 				     (const struct sockaddr *)sa6_src,
490 				     0, cmd, notify);
491 }
492 
493 static int
494 udp6_getcred(SYSCTL_HANDLER_ARGS)
495 {
496 	struct xucred xuc;
497 	struct sockaddr_in6 addrs[2];
498 	struct inpcb *inp;
499 	int error, s;
500 
501 	error = suser(req->td);
502 	if (error)
503 		return (error);
504 
505 	if (req->newlen != sizeof(addrs))
506 		return (EINVAL);
507 	if (req->oldlen != sizeof(struct xucred))
508 		return (EINVAL);
509 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
510 	if (error)
511 		return (error);
512 	s = splnet();
513 	inp = in6_pcblookup_hash(&udbinfo, &addrs[1].sin6_addr,
514 				 addrs[1].sin6_port,
515 				 &addrs[0].sin6_addr, addrs[0].sin6_port,
516 				 1, NULL);
517 	if (!inp || !inp->inp_socket) {
518 		error = ENOENT;
519 		goto out;
520 	}
521 	cru2x(inp->inp_socket->so_cred, &xuc);
522 	error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
523 out:
524 	splx(s);
525 	return (error);
526 }
527 
528 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
529 	    0, 0,
530 	    udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
531 
532 static int
533 udp6_abort(struct socket *so)
534 {
535 	struct inpcb *inp;
536 	int s;
537 
538 	inp = sotoinpcb(so);
539 	if (inp == 0)
540 		return EINVAL;	/* ??? possible? panic instead? */
541 	soisdisconnected(so);
542 	s = splnet();
543 	in6_pcbdetach(inp);
544 	splx(s);
545 	return 0;
546 }
547 
548 static int
549 udp6_attach(struct socket *so, int proto, struct thread *td)
550 {
551 	struct inpcb *inp;
552 	int s, error;
553 
554 	inp = sotoinpcb(so);
555 	if (inp != 0)
556 		return EINVAL;
557 
558 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
559 		error = soreserve(so, udp_sendspace, udp_recvspace);
560 		if (error)
561 			return error;
562 	}
563 	s = splnet();
564 	error = in_pcballoc(so, &udbinfo, td);
565 	splx(s);
566 	if (error)
567 		return error;
568 	inp = (struct inpcb *)so->so_pcb;
569 	inp->inp_vflag |= INP_IPV6;
570 	if (!ip6_v6only)
571 		inp->inp_vflag |= INP_IPV4;
572 	inp->in6p_hops = -1;	/* use kernel default */
573 	inp->in6p_cksum = -1;	/* just to be sure */
574 	/*
575 	 * XXX: ugly!!
576 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
577 	 * because the socket may be bound to an IPv6 wildcard address,
578 	 * which may match an IPv4-mapped IPv6 address.
579 	 */
580 	inp->inp_ip_ttl = ip_defttl;
581 	return 0;
582 }
583 
584 static int
585 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
586 {
587 	struct inpcb *inp;
588 	int s, error;
589 
590 	inp = sotoinpcb(so);
591 	if (inp == 0)
592 		return EINVAL;
593 
594 	inp->inp_vflag &= ~INP_IPV4;
595 	inp->inp_vflag |= INP_IPV6;
596 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
597 		struct sockaddr_in6 *sin6_p;
598 
599 		sin6_p = (struct sockaddr_in6 *)nam;
600 
601 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
602 			inp->inp_vflag |= INP_IPV4;
603 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
604 			struct sockaddr_in sin;
605 
606 			in6_sin6_2_sin(&sin, sin6_p);
607 			inp->inp_vflag |= INP_IPV4;
608 			inp->inp_vflag &= ~INP_IPV6;
609 			s = splnet();
610 			error = in_pcbbind(inp, (struct sockaddr *)&sin, td);
611 			splx(s);
612 			return error;
613 		}
614 	}
615 
616 	s = splnet();
617 	error = in6_pcbbind(inp, nam, td);
618 	splx(s);
619 	return error;
620 }
621 
622 static int
623 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
624 {
625 	struct inpcb *inp;
626 	int s, error;
627 
628 	inp = sotoinpcb(so);
629 	if (inp == 0)
630 		return EINVAL;
631 
632 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
633 		struct sockaddr_in6 *sin6_p;
634 
635 		sin6_p = (struct sockaddr_in6 *)nam;
636 		if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
637 			struct sockaddr_in sin;
638 
639 			if (inp->inp_faddr.s_addr != INADDR_ANY)
640 				return EISCONN;
641 			in6_sin6_2_sin(&sin, sin6_p);
642 			s = splnet();
643 			error = in_pcbconnect(inp, (struct sockaddr *)&sin, td);
644 			splx(s);
645 			if (error == 0) {
646 				inp->inp_vflag |= INP_IPV4;
647 				inp->inp_vflag &= ~INP_IPV6;
648 				soisconnected(so);
649 			}
650 			return error;
651 		}
652 	}
653 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
654 		return EISCONN;
655 	s = splnet();
656 	error = in6_pcbconnect(inp, nam, td);
657 	splx(s);
658 	if (error == 0) {
659 		if (!ip6_v6only) { /* should be non mapped addr */
660 			inp->inp_vflag &= ~INP_IPV4;
661 			inp->inp_vflag |= INP_IPV6;
662 		}
663 		soisconnected(so);
664 	}
665 	return error;
666 }
667 
668 static int
669 udp6_detach(struct socket *so)
670 {
671 	struct inpcb *inp;
672 	int s;
673 
674 	inp = sotoinpcb(so);
675 	if (inp == 0)
676 		return EINVAL;
677 	s = splnet();
678 	in6_pcbdetach(inp);
679 	splx(s);
680 	return 0;
681 }
682 
683 static int
684 udp6_disconnect(struct socket *so)
685 {
686 	struct inpcb *inp;
687 	int s;
688 
689 	inp = sotoinpcb(so);
690 	if (inp == 0)
691 		return EINVAL;
692 
693 	if (inp->inp_vflag & INP_IPV4) {
694 		struct pr_usrreqs *pru;
695 
696 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
697 		return ((*pru->pru_disconnect)(so));
698 	}
699 
700 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
701 		return ENOTCONN;
702 
703 	s = splnet();
704 	in6_pcbdisconnect(inp);
705 	inp->in6p_laddr = in6addr_any;
706 	splx(s);
707 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
708 	return 0;
709 }
710 
711 static int
712 udp6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
713 	  struct mbuf *control, struct thread *td)
714 {
715 	struct inpcb *inp;
716 	int error = 0;
717 
718 	inp = sotoinpcb(so);
719 	if (inp == 0) {
720 		error = EINVAL;
721 		goto bad;
722 	}
723 
724 	if (addr) {
725 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
726 			error = EINVAL;
727 			goto bad;
728 		}
729 		if (addr->sa_family != AF_INET6) {
730 			error = EAFNOSUPPORT;
731 			goto bad;
732 		}
733 	}
734 
735 	if (!ip6_v6only) {
736 		int hasv4addr;
737 		struct sockaddr_in6 *sin6 = 0;
738 
739 		if (addr == 0)
740 			hasv4addr = (inp->inp_vflag & INP_IPV4);
741 		else {
742 			sin6 = (struct sockaddr_in6 *)addr;
743 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
744 				? 1 : 0;
745 		}
746 		if (hasv4addr) {
747 			struct pr_usrreqs *pru;
748 
749 			if (sin6)
750 				in6_sin6_2_sin_in_sock(addr);
751 			pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
752 			error = ((*pru->pru_send)(so, flags, m, addr, control,
753 						  td));
754 			/* addr will just be freed in sendit(). */
755 			return error;
756 		}
757 	}
758 
759 	return udp6_output(inp, m, addr, control, td);
760 
761   bad:
762 	m_freem(m);
763 	return(error);
764 }
765 
766 struct pr_usrreqs udp6_usrreqs = {
767 	udp6_abort, pru_accept_notsupp, udp6_attach, udp6_bind, udp6_connect,
768 	pru_connect2_notsupp, in6_control, udp6_detach, udp6_disconnect,
769 	pru_listen_notsupp, in6_mapped_peeraddr, pru_rcvd_notsupp,
770 	pru_rcvoob_notsupp, udp6_send, pru_sense_null, udp_shutdown,
771 	in6_mapped_sockaddr, sosend, soreceive, sopoll
772 };
773