xref: /dragonfly/sys/netinet6/udp6_usrreq.c (revision 6e285212)
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 1.2 2003/06/17 04:28:53 dillon 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 <netipsec/ipsec.h>
112 #include <netipsec/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 __P((struct inpcb *, struct in6_addr *, struct ifnet *));
122 static	int udp6_detach __P((struct socket *so));
123 
124 static int
125 in6_mcmatch(in6p, ia6, ifp)
126 	struct inpcb *in6p;
127 	register 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(mp, offp, proto)
149 	struct mbuf **mp;
150 	int *offp, proto;
151 {
152 	struct mbuf *m = *mp;
153 	register struct ip6_hdr *ip6;
154 	register struct udphdr *uh;
155 	register struct inpcb *in6p;
156 	struct  mbuf *opts = NULL;
157 	int off = *offp;
158 	int plen, ulen;
159 	struct sockaddr_in6 udp_in6;
160 
161 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
162 
163 	ip6 = mtod(m, struct ip6_hdr *);
164 
165 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
166 		/* XXX send icmp6 host/port unreach? */
167 		m_freem(m);
168 		return IPPROTO_DONE;
169 	}
170 
171 	udpstat.udps_ipackets++;
172 
173 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
174 	uh = (struct udphdr *)((caddr_t)ip6 + off);
175 	ulen = ntohs((u_short)uh->uh_ulen);
176 
177 	if (plen != ulen) {
178 		udpstat.udps_badlen++;
179 		goto bad;
180 	}
181 
182 	/*
183 	 * Checksum extended UDP header and data.
184 	 */
185 	if (uh->uh_sum == 0)
186 		udpstat.udps_nosum++;
187 	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
188 		udpstat.udps_badsum++;
189 		goto bad;
190 	}
191 
192 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
193 		struct	inpcb *last;
194 
195 		/*
196 		 * Deliver a multicast datagram to all sockets
197 		 * for which the local and remote addresses and ports match
198 		 * those of the incoming datagram.  This allows more than
199 		 * one process to receive multicasts on the same port.
200 		 * (This really ought to be done for unicast datagrams as
201 		 * well, but that would cause problems with existing
202 		 * applications that open both address-specific sockets and
203 		 * a wildcard socket listening to the same port -- they would
204 		 * end up receiving duplicates of every unicast datagram.
205 		 * Those applications open the multiple sockets to overcome an
206 		 * inadequacy of the UDP socket interface, but for backwards
207 		 * compatibility we avoid the problem here rather than
208 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
209 		 */
210 
211 		/*
212 		 * In a case that laddr should be set to the link-local
213 		 * address (this happens in RIPng), the multicast address
214 		 * specified in the received packet does not match with
215 		 * laddr. To cure this situation, the matching is relaxed
216 		 * if the receiving interface is the same as one specified
217 		 * in the socket and if the destination multicast address
218 		 * matches one of the multicast groups specified in the socket.
219 		 */
220 
221 		/*
222 		 * Construct sockaddr format source address.
223 		 */
224 		init_sin6(&udp_in6, m); /* general init */
225 		udp_in6.sin6_port = uh->uh_sport;
226 		/*
227 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
228 		 * We need udphdr for IPsec processing so we do that later.
229 		 */
230 
231 		/*
232 		 * Locate pcb(s) for datagram.
233 		 * (Algorithm copied from raw_intr().)
234 		 */
235 		last = NULL;
236 		LIST_FOREACH(in6p, &udb, inp_list) {
237 			if ((in6p->inp_vflag & INP_IPV6) == 0)
238 				continue;
239 			if (in6p->in6p_lport != uh->uh_dport)
240 				continue;
241 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
242 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
243 							&ip6->ip6_dst) &&
244 				    !in6_mcmatch(in6p, &ip6->ip6_dst,
245 						 m->m_pkthdr.rcvif))
246 					continue;
247 			}
248 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
249 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
250 							&ip6->ip6_src) ||
251 				   in6p->in6p_fport != uh->uh_sport)
252 					continue;
253 			}
254 
255 			if (last != NULL) {
256 				struct	mbuf *n;
257 
258 #ifdef IPSEC
259 				/*
260 				 * Check AH/ESP integrity.
261 				 */
262 				if (ipsec6_in_reject_so(m, last->inp_socket))
263 					ipsec6stat.in_polvio++;
264 					/* do not inject data into pcb */
265 				else
266 #endif /* IPSEC */
267 #ifdef FAST_IPSEC
268 				/*
269 				 * Check AH/ESP integrity.
270 				 */
271 				if (ipsec6_in_reject(m, last))
272 					;
273 				else
274 #endif /* FAST_IPSEC */
275 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
276 					/*
277 					 * KAME NOTE: do not
278 					 * m_copy(m, offset, ...) above.
279 					 * sbappendaddr() expects M_PKTHDR,
280 					 * and m_copy() will copy M_PKTHDR
281 					 * only if offset is 0.
282 					 */
283 					if (last->in6p_flags & IN6P_CONTROLOPTS
284 					    || last->in6p_socket->so_options & SO_TIMESTAMP)
285 						ip6_savecontrol(last, &opts,
286 								ip6, n);
287 
288 					m_adj(n, off + sizeof(struct udphdr));
289 					if (sbappendaddr(&last->in6p_socket->so_rcv,
290 							(struct sockaddr *)&udp_in6,
291 							n, opts) == 0) {
292 						m_freem(n);
293 						if (opts)
294 							m_freem(opts);
295 						udpstat.udps_fullsock++;
296 					} else
297 						sorwakeup(last->in6p_socket);
298 					opts = NULL;
299 				}
300 			}
301 			last = in6p;
302 			/*
303 			 * Don't look for additional matches if this one does
304 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
305 			 * socket options set.  This heuristic avoids searching
306 			 * through all pcbs in the common case of a non-shared
307 			 * port.  It assumes that an application will never
308 			 * clear these options after setting them.
309 			 */
310 			if ((last->in6p_socket->so_options &
311 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
312 				break;
313 		}
314 
315 		if (last == NULL) {
316 			/*
317 			 * No matching pcb found; discard datagram.
318 			 * (No need to send an ICMP Port Unreachable
319 			 * for a broadcast or multicast datgram.)
320 			 */
321 			udpstat.udps_noport++;
322 			udpstat.udps_noportmcast++;
323 			goto bad;
324 		}
325 #ifdef IPSEC
326 		/*
327 		 * Check AH/ESP integrity.
328 		 */
329 		if (ipsec6_in_reject_so(m, last->inp_socket)) {
330 			ipsec6stat.in_polvio++;
331 			goto bad;
332 		}
333 #endif /* IPSEC */
334 #ifdef FAST_IPSEC
335 		/*
336 		 * Check AH/ESP integrity.
337 		 */
338 		if (ipsec6_in_reject(m, last)) {
339 			goto bad;
340 		}
341 #endif /* FAST_IPSEC */
342 		if (last->in6p_flags & IN6P_CONTROLOPTS
343 		    || last->in6p_socket->so_options & SO_TIMESTAMP)
344 			ip6_savecontrol(last, &opts, ip6, m);
345 
346 		m_adj(m, off + sizeof(struct udphdr));
347 		if (sbappendaddr(&last->in6p_socket->so_rcv,
348 				(struct sockaddr *)&udp_in6,
349 				m, opts) == 0) {
350 			udpstat.udps_fullsock++;
351 			goto bad;
352 		}
353 		sorwakeup(last->in6p_socket);
354 		return IPPROTO_DONE;
355 	}
356 	/*
357 	 * Locate pcb for datagram.
358 	 */
359 	in6p = in6_pcblookup_hash(&udbinfo, &ip6->ip6_src, uh->uh_sport,
360 				  &ip6->ip6_dst, uh->uh_dport, 1,
361 				  m->m_pkthdr.rcvif);
362 	if (in6p == 0) {
363 		if (log_in_vain) {
364 			char buf[INET6_ADDRSTRLEN];
365 
366 			strcpy(buf, ip6_sprintf(&ip6->ip6_dst));
367 			log(LOG_INFO,
368 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
369 			    buf, ntohs(uh->uh_dport),
370 			    ip6_sprintf(&ip6->ip6_src), ntohs(uh->uh_sport));
371 		}
372 		udpstat.udps_noport++;
373 		if (m->m_flags & M_MCAST) {
374 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
375 			udpstat.udps_noportmcast++;
376 			goto bad;
377 		}
378 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
379 		return IPPROTO_DONE;
380 	}
381 #ifdef IPSEC
382 	/*
383 	 * Check AH/ESP integrity.
384 	 */
385 	if (ipsec6_in_reject_so(m, in6p->in6p_socket)) {
386 		ipsec6stat.in_polvio++;
387 		goto bad;
388 	}
389 #endif /* IPSEC */
390 #ifdef FAST_IPSEC
391 	/*
392 	 * Check AH/ESP integrity.
393 	 */
394 	if (ipsec6_in_reject(m, in6p)) {
395 		goto bad;
396 	}
397 #endif /* FAST_IPSEC */
398 
399 	/*
400 	 * Construct sockaddr format source address.
401 	 * Stuff source address and datagram in user buffer.
402 	 */
403 	init_sin6(&udp_in6, m); /* general init */
404 	udp_in6.sin6_port = uh->uh_sport;
405 	if (in6p->in6p_flags & IN6P_CONTROLOPTS
406 	    || in6p->in6p_socket->so_options & SO_TIMESTAMP)
407 		ip6_savecontrol(in6p, &opts, ip6, m);
408 	m_adj(m, off + sizeof(struct udphdr));
409 	if (sbappendaddr(&in6p->in6p_socket->so_rcv,
410 			(struct sockaddr *)&udp_in6,
411 			m, opts) == 0) {
412 		udpstat.udps_fullsock++;
413 		goto bad;
414 	}
415 	sorwakeup(in6p->in6p_socket);
416 	return IPPROTO_DONE;
417 bad:
418 	if (m)
419 		m_freem(m);
420 	if (opts)
421 		m_freem(opts);
422 	return IPPROTO_DONE;
423 }
424 
425 void
426 udp6_ctlinput(cmd, sa, d)
427 	int cmd;
428 	struct sockaddr *sa;
429 	void *d;
430 {
431 	struct udphdr uh;
432 	struct ip6_hdr *ip6;
433 	struct mbuf *m;
434 	int off = 0;
435 	struct ip6ctlparam *ip6cp = NULL;
436 	const struct sockaddr_in6 *sa6_src = NULL;
437 	void (*notify) __P((struct inpcb *, int)) = udp_notify;
438 	struct udp_portonly {
439 		u_int16_t uh_sport;
440 		u_int16_t uh_dport;
441 	} *uhp;
442 
443 	if (sa->sa_family != AF_INET6 ||
444 	    sa->sa_len != sizeof(struct sockaddr_in6))
445 		return;
446 
447 	if ((unsigned)cmd >= PRC_NCMDS)
448 		return;
449 	if (PRC_IS_REDIRECT(cmd))
450 		notify = in6_rtchange, d = NULL;
451 	else if (cmd == PRC_HOSTDEAD)
452 		d = NULL;
453 	else if (inet6ctlerrmap[cmd] == 0)
454 		return;
455 
456 	/* if the parameter is from icmp6, decode it. */
457 	if (d != NULL) {
458 		ip6cp = (struct ip6ctlparam *)d;
459 		m = ip6cp->ip6c_m;
460 		ip6 = ip6cp->ip6c_ip6;
461 		off = ip6cp->ip6c_off;
462 		sa6_src = ip6cp->ip6c_src;
463 	} else {
464 		m = NULL;
465 		ip6 = NULL;
466 		sa6_src = &sa6_any;
467 	}
468 
469 	if (ip6) {
470 		/*
471 		 * XXX: We assume that when IPV6 is non NULL,
472 		 * M and OFF are valid.
473 		 */
474 
475 		/* check if we can safely examine src and dst ports */
476 		if (m->m_pkthdr.len < off + sizeof(*uhp))
477 			return;
478 
479 		bzero(&uh, sizeof(uh));
480 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
481 
482 		(void) in6_pcbnotify(&udb, sa, uh.uh_dport,
483 				     (struct sockaddr *)ip6cp->ip6c_src,
484 				     uh.uh_sport, cmd, notify);
485 	} else
486 		(void) in6_pcbnotify(&udb, sa, 0, (struct sockaddr *)sa6_src,
487 				     0, cmd, notify);
488 }
489 
490 static int
491 udp6_getcred(SYSCTL_HANDLER_ARGS)
492 {
493 	struct sockaddr_in6 addrs[2];
494 	struct inpcb *inp;
495 	int error, s;
496 
497 	error = suser(req->p);
498 	if (error)
499 		return (error);
500 
501 	if (req->newlen != sizeof(addrs))
502 		return (EINVAL);
503 	if (req->oldlen != sizeof(struct ucred))
504 		return (EINVAL);
505 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
506 	if (error)
507 		return (error);
508 	s = splnet();
509 	inp = in6_pcblookup_hash(&udbinfo, &addrs[1].sin6_addr,
510 				 addrs[1].sin6_port,
511 				 &addrs[0].sin6_addr, addrs[0].sin6_port,
512 				 1, NULL);
513 	if (!inp || !inp->inp_socket) {
514 		error = ENOENT;
515 		goto out;
516 	}
517 	error = SYSCTL_OUT(req, inp->inp_socket->so_cred,
518 			   sizeof(struct ucred));
519 
520 out:
521 	splx(s);
522 	return (error);
523 }
524 
525 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
526 	    0, 0,
527 	    udp6_getcred, "S,ucred", "Get the ucred of a UDP6 connection");
528 
529 static int
530 udp6_abort(struct socket *so)
531 {
532 	struct inpcb *inp;
533 	int s;
534 
535 	inp = sotoinpcb(so);
536 	if (inp == 0)
537 		return EINVAL;	/* ??? possible? panic instead? */
538 	soisdisconnected(so);
539 	s = splnet();
540 	in6_pcbdetach(inp);
541 	splx(s);
542 	return 0;
543 }
544 
545 static int
546 udp6_attach(struct socket *so, int proto, struct proc *p)
547 {
548 	struct inpcb *inp;
549 	int s, error;
550 
551 	inp = sotoinpcb(so);
552 	if (inp != 0)
553 		return EINVAL;
554 
555 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
556 		error = soreserve(so, udp_sendspace, udp_recvspace);
557 		if (error)
558 			return error;
559 	}
560 	s = splnet();
561 	error = in_pcballoc(so, &udbinfo, p);
562 	splx(s);
563 	if (error)
564 		return error;
565 	inp = (struct inpcb *)so->so_pcb;
566 	inp->inp_vflag |= INP_IPV6;
567 	if (!ip6_v6only)
568 		inp->inp_vflag |= INP_IPV4;
569 	inp->in6p_hops = -1;	/* use kernel default */
570 	inp->in6p_cksum = -1;	/* just to be sure */
571 	/*
572 	 * XXX: ugly!!
573 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
574 	 * because the socket may be bound to an IPv6 wildcard address,
575 	 * which may match an IPv4-mapped IPv6 address.
576 	 */
577 	inp->inp_ip_ttl = ip_defttl;
578 	return 0;
579 }
580 
581 static int
582 udp6_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
583 {
584 	struct inpcb *inp;
585 	int s, error;
586 
587 	inp = sotoinpcb(so);
588 	if (inp == 0)
589 		return EINVAL;
590 
591 	inp->inp_vflag &= ~INP_IPV4;
592 	inp->inp_vflag |= INP_IPV6;
593 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
594 		struct sockaddr_in6 *sin6_p;
595 
596 		sin6_p = (struct sockaddr_in6 *)nam;
597 
598 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
599 			inp->inp_vflag |= INP_IPV4;
600 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
601 			struct sockaddr_in sin;
602 
603 			in6_sin6_2_sin(&sin, sin6_p);
604 			inp->inp_vflag |= INP_IPV4;
605 			inp->inp_vflag &= ~INP_IPV6;
606 			s = splnet();
607 			error = in_pcbbind(inp, (struct sockaddr *)&sin, p);
608 			splx(s);
609 			return error;
610 		}
611 	}
612 
613 	s = splnet();
614 	error = in6_pcbbind(inp, nam, p);
615 	splx(s);
616 	return error;
617 }
618 
619 static int
620 udp6_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
621 {
622 	struct inpcb *inp;
623 	int s, error;
624 
625 	inp = sotoinpcb(so);
626 	if (inp == 0)
627 		return EINVAL;
628 
629 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
630 		struct sockaddr_in6 *sin6_p;
631 
632 		sin6_p = (struct sockaddr_in6 *)nam;
633 		if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
634 			struct sockaddr_in sin;
635 
636 			if (inp->inp_faddr.s_addr != INADDR_ANY)
637 				return EISCONN;
638 			in6_sin6_2_sin(&sin, sin6_p);
639 			s = splnet();
640 			error = in_pcbconnect(inp, (struct sockaddr *)&sin, p);
641 			splx(s);
642 			if (error == 0) {
643 				inp->inp_vflag |= INP_IPV4;
644 				inp->inp_vflag &= ~INP_IPV6;
645 				soisconnected(so);
646 			}
647 			return error;
648 		}
649 	}
650 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
651 		return EISCONN;
652 	s = splnet();
653 	error = in6_pcbconnect(inp, nam, p);
654 	splx(s);
655 	if (error == 0) {
656 		if (!ip6_v6only) { /* should be non mapped addr */
657 			inp->inp_vflag &= ~INP_IPV4;
658 			inp->inp_vflag |= INP_IPV6;
659 		}
660 		soisconnected(so);
661 	}
662 	return error;
663 }
664 
665 static int
666 udp6_detach(struct socket *so)
667 {
668 	struct inpcb *inp;
669 	int s;
670 
671 	inp = sotoinpcb(so);
672 	if (inp == 0)
673 		return EINVAL;
674 	s = splnet();
675 	in6_pcbdetach(inp);
676 	splx(s);
677 	return 0;
678 }
679 
680 static int
681 udp6_disconnect(struct socket *so)
682 {
683 	struct inpcb *inp;
684 	int s;
685 
686 	inp = sotoinpcb(so);
687 	if (inp == 0)
688 		return EINVAL;
689 
690 	if (inp->inp_vflag & INP_IPV4) {
691 		struct pr_usrreqs *pru;
692 
693 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
694 		return ((*pru->pru_disconnect)(so));
695 	}
696 
697 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
698 		return ENOTCONN;
699 
700 	s = splnet();
701 	in6_pcbdisconnect(inp);
702 	inp->in6p_laddr = in6addr_any;
703 	splx(s);
704 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
705 	return 0;
706 }
707 
708 static int
709 udp6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
710 	  struct mbuf *control, struct proc *p)
711 {
712 	struct inpcb *inp;
713 	int error = 0;
714 
715 	inp = sotoinpcb(so);
716 	if (inp == 0) {
717 		error = EINVAL;
718 		goto bad;
719 	}
720 
721 	if (addr) {
722 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
723 			error = EINVAL;
724 			goto bad;
725 		}
726 		if (addr->sa_family != AF_INET6) {
727 			error = EAFNOSUPPORT;
728 			goto bad;
729 		}
730 	}
731 
732 	if (!ip6_v6only) {
733 		int hasv4addr;
734 		struct sockaddr_in6 *sin6 = 0;
735 
736 		if (addr == 0)
737 			hasv4addr = (inp->inp_vflag & INP_IPV4);
738 		else {
739 			sin6 = (struct sockaddr_in6 *)addr;
740 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
741 				? 1 : 0;
742 		}
743 		if (hasv4addr) {
744 			struct pr_usrreqs *pru;
745 
746 			if (sin6)
747 				in6_sin6_2_sin_in_sock(addr);
748 			pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
749 			error = ((*pru->pru_send)(so, flags, m, addr, control,
750 						  p));
751 			/* addr will just be freed in sendit(). */
752 			return error;
753 		}
754 	}
755 
756 	return udp6_output(inp, m, addr, control, p);
757 
758   bad:
759 	m_freem(m);
760 	return(error);
761 }
762 
763 struct pr_usrreqs udp6_usrreqs = {
764 	udp6_abort, pru_accept_notsupp, udp6_attach, udp6_bind, udp6_connect,
765 	pru_connect2_notsupp, in6_control, udp6_detach, udp6_disconnect,
766 	pru_listen_notsupp, in6_mapped_peeraddr, pru_rcvd_notsupp,
767 	pru_rcvoob_notsupp, udp6_send, pru_sense_null, udp_shutdown,
768 	in6_mapped_sockaddr, sosend, soreceive, sopoll
769 };
770