xref: /dragonfly/sys/netinet6/udp6_usrreq.c (revision 4e7eb5cc)
1 /*	$FreeBSD: src/sys/netinet6/udp6_usrreq.c,v 1.6.2.13 2003/01/24 05:11:35 sam Exp $	*/
2 /*	$DragonFly: src/sys/netinet6/udp6_usrreq.c,v 1.9 2003/08/23 11:02:46 rob Exp $	*/
3 /*	$KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1982, 1986, 1989, 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  *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
67  */
68 
69 #include "opt_inet.h"
70 #include "opt_inet6.h"
71 #include "opt_ipsec.h"
72 
73 #include <sys/param.h>
74 #include <sys/kernel.h>
75 #include <sys/mbuf.h>
76 #include <sys/protosw.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #include <sys/sysctl.h>
80 #include <sys/errno.h>
81 #include <sys/stat.h>
82 #include <sys/systm.h>
83 #include <sys/syslog.h>
84 #include <sys/proc.h>
85 
86 #include <net/if.h>
87 #include <net/route.h>
88 #include <net/if_types.h>
89 
90 #include <netinet/in.h>
91 #include <netinet/in_systm.h>
92 #include <netinet/ip.h>
93 #include <netinet/in_pcb.h>
94 #include <netinet/in_var.h>
95 #include <netinet/ip_var.h>
96 #include <netinet/udp.h>
97 #include <netinet/udp_var.h>
98 #include <netinet/ip6.h>
99 #include <netinet6/ip6_var.h>
100 #include <netinet6/in6_pcb.h>
101 #include <netinet/icmp6.h>
102 #include <netinet6/udp6_var.h>
103 #include <netinet6/ip6protosw.h>
104 
105 #ifdef IPSEC
106 #include <netinet6/ipsec.h>
107 #include <netinet6/ipsec6.h>
108 #endif /* IPSEC */
109 
110 #ifdef FAST_IPSEC
111 #include "ipsec.h"
112 #include "ipsec6.h"
113 #endif /* FAST_IPSEC */
114 
115 /*
116  * UDP protocol inplementation.
117  * Per RFC 768, August, 1980.
118  */
119 
120 extern	struct protosw inetsw[];
121 static	int in6_mcmatch (struct inpcb *, struct in6_addr *, struct ifnet *);
122 static	int udp6_detach (struct socket *so);
123 
124 static int
125 in6_mcmatch(in6p, ia6, ifp)
126 	struct inpcb *in6p;
127 	struct in6_addr *ia6;
128 	struct ifnet *ifp;
129 {
130 	struct ip6_moptions *im6o = in6p->in6p_moptions;
131 	struct in6_multi_mship *imm;
132 
133 	if (im6o == NULL)
134 		return 0;
135 
136 	for (imm = im6o->im6o_memberships.lh_first; imm != NULL;
137 	     imm = imm->i6mm_chain.le_next) {
138 		if ((ifp == NULL ||
139 		     imm->i6mm_maddr->in6m_ifp == ifp) &&
140 		    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
141 				       ia6))
142 			return 1;
143 	}
144 	return 0;
145 }
146 
147 int
148 udp6_input(struct mbuf **mp, int *offp, int proto)
149 {
150 	struct mbuf *m = *mp;
151 	struct ip6_hdr *ip6;
152 	struct udphdr *uh;
153 	struct inpcb *in6p;
154 	struct  mbuf *opts = NULL;
155 	int off = *offp;
156 	int plen, ulen;
157 	struct sockaddr_in6 udp_in6;
158 
159 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
160 
161 	ip6 = mtod(m, struct ip6_hdr *);
162 
163 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
164 		/* XXX send icmp6 host/port unreach? */
165 		m_freem(m);
166 		return IPPROTO_DONE;
167 	}
168 
169 	udpstat.udps_ipackets++;
170 
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: traditionally we dropped udpiphdr 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 #ifdef FAST_IPSEC
266 				/*
267 				 * Check AH/ESP integrity.
268 				 */
269 				if (ipsec6_in_reject(m, last))
270 					;
271 				else
272 #endif /* FAST_IPSEC */
273 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
274 					/*
275 					 * KAME NOTE: do not
276 					 * m_copy(m, offset, ...) above.
277 					 * sbappendaddr() expects M_PKTHDR,
278 					 * and m_copy() will copy M_PKTHDR
279 					 * only if offset is 0.
280 					 */
281 					if (last->in6p_flags & IN6P_CONTROLOPTS
282 					    || last->in6p_socket->so_options & SO_TIMESTAMP)
283 						ip6_savecontrol(last, &opts,
284 								ip6, n);
285 
286 					m_adj(n, off + sizeof(struct udphdr));
287 					if (sbappendaddr(&last->in6p_socket->so_rcv,
288 							(struct sockaddr *)&udp_in6,
289 							n, opts) == 0) {
290 						m_freem(n);
291 						if (opts)
292 							m_freem(opts);
293 						udpstat.udps_fullsock++;
294 					} else
295 						sorwakeup(last->in6p_socket);
296 					opts = NULL;
297 				}
298 			}
299 			last = in6p;
300 			/*
301 			 * Don't look for additional matches if this one does
302 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
303 			 * socket options set.  This heuristic avoids searching
304 			 * through all pcbs in the common case of a non-shared
305 			 * port.  It assumes that an application will never
306 			 * clear these options after setting them.
307 			 */
308 			if ((last->in6p_socket->so_options &
309 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
310 				break;
311 		}
312 
313 		if (last == NULL) {
314 			/*
315 			 * No matching pcb found; discard datagram.
316 			 * (No need to send an ICMP Port Unreachable
317 			 * for a broadcast or multicast datgram.)
318 			 */
319 			udpstat.udps_noport++;
320 			udpstat.udps_noportmcast++;
321 			goto bad;
322 		}
323 #ifdef IPSEC
324 		/*
325 		 * Check AH/ESP integrity.
326 		 */
327 		if (ipsec6_in_reject_so(m, last->inp_socket)) {
328 			ipsec6stat.in_polvio++;
329 			goto bad;
330 		}
331 #endif /* IPSEC */
332 #ifdef FAST_IPSEC
333 		/*
334 		 * Check AH/ESP integrity.
335 		 */
336 		if (ipsec6_in_reject(m, last)) {
337 			goto bad;
338 		}
339 #endif /* FAST_IPSEC */
340 		if (last->in6p_flags & IN6P_CONTROLOPTS
341 		    || last->in6p_socket->so_options & SO_TIMESTAMP)
342 			ip6_savecontrol(last, &opts, ip6, m);
343 
344 		m_adj(m, off + sizeof(struct udphdr));
345 		if (sbappendaddr(&last->in6p_socket->so_rcv,
346 				(struct sockaddr *)&udp_in6,
347 				m, opts) == 0) {
348 			udpstat.udps_fullsock++;
349 			goto bad;
350 		}
351 		sorwakeup(last->in6p_socket);
352 		return IPPROTO_DONE;
353 	}
354 	/*
355 	 * Locate pcb for datagram.
356 	 */
357 	in6p = in6_pcblookup_hash(&udbinfo, &ip6->ip6_src, uh->uh_sport,
358 				  &ip6->ip6_dst, uh->uh_dport, 1,
359 				  m->m_pkthdr.rcvif);
360 	if (in6p == 0) {
361 		if (log_in_vain) {
362 			char buf[INET6_ADDRSTRLEN];
363 
364 			strcpy(buf, ip6_sprintf(&ip6->ip6_dst));
365 			log(LOG_INFO,
366 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
367 			    buf, ntohs(uh->uh_dport),
368 			    ip6_sprintf(&ip6->ip6_src), ntohs(uh->uh_sport));
369 		}
370 		udpstat.udps_noport++;
371 		if (m->m_flags & M_MCAST) {
372 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
373 			udpstat.udps_noportmcast++;
374 			goto bad;
375 		}
376 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
377 		return IPPROTO_DONE;
378 	}
379 #ifdef IPSEC
380 	/*
381 	 * Check AH/ESP integrity.
382 	 */
383 	if (ipsec6_in_reject_so(m, in6p->in6p_socket)) {
384 		ipsec6stat.in_polvio++;
385 		goto bad;
386 	}
387 #endif /* IPSEC */
388 #ifdef FAST_IPSEC
389 	/*
390 	 * Check AH/ESP integrity.
391 	 */
392 	if (ipsec6_in_reject(m, in6p)) {
393 		goto bad;
394 	}
395 #endif /* FAST_IPSEC */
396 
397 	/*
398 	 * Construct sockaddr format source address.
399 	 * Stuff source address and datagram in user buffer.
400 	 */
401 	init_sin6(&udp_in6, m); /* general init */
402 	udp_in6.sin6_port = uh->uh_sport;
403 	if (in6p->in6p_flags & IN6P_CONTROLOPTS
404 	    || in6p->in6p_socket->so_options & SO_TIMESTAMP)
405 		ip6_savecontrol(in6p, &opts, ip6, m);
406 	m_adj(m, off + sizeof(struct udphdr));
407 	if (sbappendaddr(&in6p->in6p_socket->so_rcv,
408 			(struct sockaddr *)&udp_in6,
409 			m, opts) == 0) {
410 		udpstat.udps_fullsock++;
411 		goto bad;
412 	}
413 	sorwakeup(in6p->in6p_socket);
414 	return IPPROTO_DONE;
415 bad:
416 	if (m)
417 		m_freem(m);
418 	if (opts)
419 		m_freem(opts);
420 	return IPPROTO_DONE;
421 }
422 
423 void
424 udp6_ctlinput(cmd, sa, d)
425 	int cmd;
426 	struct sockaddr *sa;
427 	void *d;
428 {
429 	struct udphdr uh;
430 	struct ip6_hdr *ip6;
431 	struct mbuf *m;
432 	int off = 0;
433 	struct ip6ctlparam *ip6cp = NULL;
434 	const struct sockaddr_in6 *sa6_src = NULL;
435 	void (*notify) (struct inpcb *, int) = udp_notify;
436 	struct udp_portonly {
437 		u_int16_t uh_sport;
438 		u_int16_t uh_dport;
439 	} *uhp;
440 
441 	if (sa->sa_family != AF_INET6 ||
442 	    sa->sa_len != sizeof(struct sockaddr_in6))
443 		return;
444 
445 	if ((unsigned)cmd >= PRC_NCMDS)
446 		return;
447 	if (PRC_IS_REDIRECT(cmd))
448 		notify = in6_rtchange, d = NULL;
449 	else if (cmd == PRC_HOSTDEAD)
450 		d = NULL;
451 	else if (inet6ctlerrmap[cmd] == 0)
452 		return;
453 
454 	/* if the parameter is from icmp6, decode it. */
455 	if (d != NULL) {
456 		ip6cp = (struct ip6ctlparam *)d;
457 		m = ip6cp->ip6c_m;
458 		ip6 = ip6cp->ip6c_ip6;
459 		off = ip6cp->ip6c_off;
460 		sa6_src = ip6cp->ip6c_src;
461 	} else {
462 		m = NULL;
463 		ip6 = NULL;
464 		sa6_src = &sa6_any;
465 	}
466 
467 	if (ip6) {
468 		/*
469 		 * XXX: We assume that when IPV6 is non NULL,
470 		 * M and OFF are valid.
471 		 */
472 
473 		/* check if we can safely examine src and dst ports */
474 		if (m->m_pkthdr.len < off + sizeof(*uhp))
475 			return;
476 
477 		bzero(&uh, sizeof(uh));
478 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
479 
480 		(void) in6_pcbnotify(&udb, sa, uh.uh_dport,
481 				     (struct sockaddr *)ip6cp->ip6c_src,
482 				     uh.uh_sport, cmd, notify);
483 	} else
484 		(void) in6_pcbnotify(&udb, sa, 0, (const struct sockaddr *)sa6_src,
485 				     0, cmd, notify);
486 }
487 
488 static int
489 udp6_getcred(SYSCTL_HANDLER_ARGS)
490 {
491 	struct sockaddr_in6 addrs[2];
492 	struct inpcb *inp;
493 	int error, s;
494 
495 	error = suser(req->td);
496 	if (error)
497 		return (error);
498 
499 	if (req->newlen != sizeof(addrs))
500 		return (EINVAL);
501 	if (req->oldlen != sizeof(struct ucred))
502 		return (EINVAL);
503 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
504 	if (error)
505 		return (error);
506 	s = splnet();
507 	inp = in6_pcblookup_hash(&udbinfo, &addrs[1].sin6_addr,
508 				 addrs[1].sin6_port,
509 				 &addrs[0].sin6_addr, addrs[0].sin6_port,
510 				 1, NULL);
511 	if (!inp || !inp->inp_socket) {
512 		error = ENOENT;
513 		goto out;
514 	}
515 	error = SYSCTL_OUT(req, inp->inp_socket->so_cred,
516 			   sizeof(struct ucred));
517 
518 out:
519 	splx(s);
520 	return (error);
521 }
522 
523 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
524 	    0, 0,
525 	    udp6_getcred, "S,ucred", "Get the ucred of a UDP6 connection");
526 
527 static int
528 udp6_abort(struct socket *so)
529 {
530 	struct inpcb *inp;
531 	int s;
532 
533 	inp = sotoinpcb(so);
534 	if (inp == 0)
535 		return EINVAL;	/* ??? possible? panic instead? */
536 	soisdisconnected(so);
537 	s = splnet();
538 	in6_pcbdetach(inp);
539 	splx(s);
540 	return 0;
541 }
542 
543 static int
544 udp6_attach(struct socket *so, int proto, struct thread *td)
545 {
546 	struct inpcb *inp;
547 	int s, error;
548 
549 	inp = sotoinpcb(so);
550 	if (inp != 0)
551 		return EINVAL;
552 
553 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
554 		error = soreserve(so, udp_sendspace, udp_recvspace);
555 		if (error)
556 			return error;
557 	}
558 	s = splnet();
559 	error = in_pcballoc(so, &udbinfo, td);
560 	splx(s);
561 	if (error)
562 		return error;
563 	inp = (struct inpcb *)so->so_pcb;
564 	inp->inp_vflag |= INP_IPV6;
565 	if (!ip6_v6only)
566 		inp->inp_vflag |= INP_IPV4;
567 	inp->in6p_hops = -1;	/* use kernel default */
568 	inp->in6p_cksum = -1;	/* just to be sure */
569 	/*
570 	 * XXX: ugly!!
571 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
572 	 * because the socket may be bound to an IPv6 wildcard address,
573 	 * which may match an IPv4-mapped IPv6 address.
574 	 */
575 	inp->inp_ip_ttl = ip_defttl;
576 	return 0;
577 }
578 
579 static int
580 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
581 {
582 	struct inpcb *inp;
583 	int s, error;
584 
585 	inp = sotoinpcb(so);
586 	if (inp == 0)
587 		return EINVAL;
588 
589 	inp->inp_vflag &= ~INP_IPV4;
590 	inp->inp_vflag |= INP_IPV6;
591 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
592 		struct sockaddr_in6 *sin6_p;
593 
594 		sin6_p = (struct sockaddr_in6 *)nam;
595 
596 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
597 			inp->inp_vflag |= INP_IPV4;
598 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
599 			struct sockaddr_in sin;
600 
601 			in6_sin6_2_sin(&sin, sin6_p);
602 			inp->inp_vflag |= INP_IPV4;
603 			inp->inp_vflag &= ~INP_IPV6;
604 			s = splnet();
605 			error = in_pcbbind(inp, (struct sockaddr *)&sin, td);
606 			splx(s);
607 			return error;
608 		}
609 	}
610 
611 	s = splnet();
612 	error = in6_pcbbind(inp, nam, td);
613 	splx(s);
614 	return error;
615 }
616 
617 static int
618 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
619 {
620 	struct inpcb *inp;
621 	int s, error;
622 
623 	inp = sotoinpcb(so);
624 	if (inp == 0)
625 		return EINVAL;
626 
627 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
628 		struct sockaddr_in6 *sin6_p;
629 
630 		sin6_p = (struct sockaddr_in6 *)nam;
631 		if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
632 			struct sockaddr_in sin;
633 
634 			if (inp->inp_faddr.s_addr != INADDR_ANY)
635 				return EISCONN;
636 			in6_sin6_2_sin(&sin, sin6_p);
637 			s = splnet();
638 			error = in_pcbconnect(inp, (struct sockaddr *)&sin, td);
639 			splx(s);
640 			if (error == 0) {
641 				inp->inp_vflag |= INP_IPV4;
642 				inp->inp_vflag &= ~INP_IPV6;
643 				soisconnected(so);
644 			}
645 			return error;
646 		}
647 	}
648 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
649 		return EISCONN;
650 	s = splnet();
651 	error = in6_pcbconnect(inp, nam, td);
652 	splx(s);
653 	if (error == 0) {
654 		if (!ip6_v6only) { /* should be non mapped addr */
655 			inp->inp_vflag &= ~INP_IPV4;
656 			inp->inp_vflag |= INP_IPV6;
657 		}
658 		soisconnected(so);
659 	}
660 	return error;
661 }
662 
663 static int
664 udp6_detach(struct socket *so)
665 {
666 	struct inpcb *inp;
667 	int s;
668 
669 	inp = sotoinpcb(so);
670 	if (inp == 0)
671 		return EINVAL;
672 	s = splnet();
673 	in6_pcbdetach(inp);
674 	splx(s);
675 	return 0;
676 }
677 
678 static int
679 udp6_disconnect(struct socket *so)
680 {
681 	struct inpcb *inp;
682 	int s;
683 
684 	inp = sotoinpcb(so);
685 	if (inp == 0)
686 		return EINVAL;
687 
688 	if (inp->inp_vflag & INP_IPV4) {
689 		struct pr_usrreqs *pru;
690 
691 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
692 		return ((*pru->pru_disconnect)(so));
693 	}
694 
695 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
696 		return ENOTCONN;
697 
698 	s = splnet();
699 	in6_pcbdisconnect(inp);
700 	inp->in6p_laddr = in6addr_any;
701 	splx(s);
702 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
703 	return 0;
704 }
705 
706 static int
707 udp6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
708 	  struct mbuf *control, struct thread *td)
709 {
710 	struct inpcb *inp;
711 	int error = 0;
712 
713 	inp = sotoinpcb(so);
714 	if (inp == 0) {
715 		error = EINVAL;
716 		goto bad;
717 	}
718 
719 	if (addr) {
720 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
721 			error = EINVAL;
722 			goto bad;
723 		}
724 		if (addr->sa_family != AF_INET6) {
725 			error = EAFNOSUPPORT;
726 			goto bad;
727 		}
728 	}
729 
730 	if (!ip6_v6only) {
731 		int hasv4addr;
732 		struct sockaddr_in6 *sin6 = 0;
733 
734 		if (addr == 0)
735 			hasv4addr = (inp->inp_vflag & INP_IPV4);
736 		else {
737 			sin6 = (struct sockaddr_in6 *)addr;
738 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
739 				? 1 : 0;
740 		}
741 		if (hasv4addr) {
742 			struct pr_usrreqs *pru;
743 
744 			if (sin6)
745 				in6_sin6_2_sin_in_sock(addr);
746 			pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
747 			error = ((*pru->pru_send)(so, flags, m, addr,
748 				    control, td));
749 			/* addr will just be freed in sendit(). */
750 			return error;
751 		}
752 	}
753 
754 	return udp6_output(inp, m, addr, control, td);
755 
756   bad:
757 	m_freem(m);
758 	return(error);
759 }
760 
761 struct pr_usrreqs udp6_usrreqs = {
762 	udp6_abort, pru_accept_notsupp, udp6_attach, udp6_bind, udp6_connect,
763 	pru_connect2_notsupp, in6_control, udp6_detach, udp6_disconnect,
764 	pru_listen_notsupp, in6_mapped_peeraddr, pru_rcvd_notsupp,
765 	pru_rcvoob_notsupp, udp6_send, pru_sense_null, udp_shutdown,
766 	in6_mapped_sockaddr, sosend, soreceive, sopoll
767 };
768