xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision ee2ea5ceafed78a5bd9810beb9e3ca927180c226)
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 /*
113  * UDP protocol inplementation.
114  * Per RFC 768, August, 1980.
115  */
116 
117 extern	struct protosw inetsw[];
118 static	int in6_mcmatch __P((struct inpcb *, struct in6_addr *, struct ifnet *));
119 static	int udp6_detach __P((struct socket *so));
120 
121 static int
122 in6_mcmatch(in6p, ia6, ifp)
123 	struct inpcb *in6p;
124 	register struct in6_addr *ia6;
125 	struct ifnet *ifp;
126 {
127 	struct ip6_moptions *im6o = in6p->in6p_moptions;
128 	struct in6_multi_mship *imm;
129 
130 	if (im6o == NULL)
131 		return 0;
132 
133 	for (imm = im6o->im6o_memberships.lh_first; imm != NULL;
134 	     imm = imm->i6mm_chain.le_next) {
135 		if ((ifp == NULL ||
136 		     imm->i6mm_maddr->in6m_ifp == ifp) &&
137 		    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
138 				       ia6))
139 			return 1;
140 	}
141 	return 0;
142 }
143 
144 int
145 udp6_input(mp, offp, proto)
146 	struct mbuf **mp;
147 	int *offp, proto;
148 {
149 	struct mbuf *m = *mp;
150 	register struct ip6_hdr *ip6;
151 	register struct udphdr *uh;
152 	register struct inpcb *in6p;
153 	struct  mbuf *opts = NULL;
154 	int off = *offp;
155 	int plen, ulen;
156 	struct sockaddr_in6 udp_in6;
157 
158 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
159 
160 	ip6 = mtod(m, struct ip6_hdr *);
161 
162 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
163 		/* XXX send icmp6 host/port unreach? */
164 		m_freem(m);
165 		return IPPROTO_DONE;
166 	}
167 
168 	udpstat.udps_ipackets++;
169 
170 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
171 	uh = (struct udphdr *)((caddr_t)ip6 + off);
172 	ulen = ntohs((u_short)uh->uh_ulen);
173 
174 	if (plen != ulen) {
175 		udpstat.udps_badlen++;
176 		goto bad;
177 	}
178 
179 	/*
180 	 * Checksum extended UDP header and data.
181 	 */
182 	if (uh->uh_sum == 0)
183 		udpstat.udps_nosum++;
184 	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
185 		udpstat.udps_badsum++;
186 		goto bad;
187 	}
188 
189 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
190 		struct	inpcb *last;
191 
192 		/*
193 		 * Deliver a multicast datagram to all sockets
194 		 * for which the local and remote addresses and ports match
195 		 * those of the incoming datagram.  This allows more than
196 		 * one process to receive multicasts on the same port.
197 		 * (This really ought to be done for unicast datagrams as
198 		 * well, but that would cause problems with existing
199 		 * applications that open both address-specific sockets and
200 		 * a wildcard socket listening to the same port -- they would
201 		 * end up receiving duplicates of every unicast datagram.
202 		 * Those applications open the multiple sockets to overcome an
203 		 * inadequacy of the UDP socket interface, but for backwards
204 		 * compatibility we avoid the problem here rather than
205 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
206 		 */
207 
208 		/*
209 		 * In a case that laddr should be set to the link-local
210 		 * address (this happens in RIPng), the multicast address
211 		 * specified in the received packet does not match with
212 		 * laddr. To cure this situation, the matching is relaxed
213 		 * if the receiving interface is the same as one specified
214 		 * in the socket and if the destination multicast address
215 		 * matches one of the multicast groups specified in the socket.
216 		 */
217 
218 		/*
219 		 * Construct sockaddr format source address.
220 		 */
221 		init_sin6(&udp_in6, m); /* general init */
222 		udp_in6.sin6_port = uh->uh_sport;
223 		/*
224 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
225 		 * We need udphdr for IPsec processing so we do that later.
226 		 */
227 
228 		/*
229 		 * Locate pcb(s) for datagram.
230 		 * (Algorithm copied from raw_intr().)
231 		 */
232 		last = NULL;
233 		LIST_FOREACH(in6p, &udb, inp_list) {
234 			if ((in6p->inp_vflag & INP_IPV6) == 0)
235 				continue;
236 			if (in6p->in6p_lport != uh->uh_dport)
237 				continue;
238 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
239 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
240 							&ip6->ip6_dst) &&
241 				    !in6_mcmatch(in6p, &ip6->ip6_dst,
242 						 m->m_pkthdr.rcvif))
243 					continue;
244 			}
245 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
246 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
247 							&ip6->ip6_src) ||
248 				   in6p->in6p_fport != uh->uh_sport)
249 					continue;
250 			}
251 
252 			if (last != NULL) {
253 				struct	mbuf *n;
254 
255 #ifdef IPSEC
256 				/*
257 				 * Check AH/ESP integrity.
258 				 */
259 				if (ipsec6_in_reject_so(m, last->inp_socket))
260 					ipsec6stat.in_polvio++;
261 					/* do not inject data into pcb */
262 				else
263 #endif /* IPSEC */
264 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
265 					/*
266 					 * KAME NOTE: do not
267 					 * m_copy(m, offset, ...) above.
268 					 * sbappendaddr() expects M_PKTHDR,
269 					 * and m_copy() will copy M_PKTHDR
270 					 * only if offset is 0.
271 					 */
272 					if (last->in6p_flags & IN6P_CONTROLOPTS
273 					    || last->in6p_socket->so_options & SO_TIMESTAMP)
274 						ip6_savecontrol(last, &opts,
275 								ip6, n);
276 
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 = NULL;
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 	struct udphdr uh;
405 	struct ip6_hdr *ip6;
406 	struct mbuf *m;
407 	int off = 0;
408 	struct ip6ctlparam *ip6cp = NULL;
409 	const struct sockaddr_in6 *sa6_src = NULL;
410 	void (*notify) __P((struct inpcb *, int)) = udp_notify;
411 	struct udp_portonly {
412 		u_int16_t uh_sport;
413 		u_int16_t uh_dport;
414 	} *uhp;
415 
416 	if (sa->sa_family != AF_INET6 ||
417 	    sa->sa_len != sizeof(struct sockaddr_in6))
418 		return;
419 
420 	if ((unsigned)cmd >= PRC_NCMDS)
421 		return;
422 	if (PRC_IS_REDIRECT(cmd))
423 		notify = in6_rtchange, d = NULL;
424 	else if (cmd == PRC_HOSTDEAD)
425 		d = NULL;
426 	else if (inet6ctlerrmap[cmd] == 0)
427 		return;
428 
429 	/* if the parameter is from icmp6, decode it. */
430 	if (d != NULL) {
431 		ip6cp = (struct ip6ctlparam *)d;
432 		m = ip6cp->ip6c_m;
433 		ip6 = ip6cp->ip6c_ip6;
434 		off = ip6cp->ip6c_off;
435 		sa6_src = ip6cp->ip6c_src;
436 	} else {
437 		m = NULL;
438 		ip6 = NULL;
439 		sa6_src = &sa6_any;
440 	}
441 
442 	if (ip6) {
443 		/*
444 		 * XXX: We assume that when IPV6 is non NULL,
445 		 * M and OFF are valid.
446 		 */
447 
448 		/* check if we can safely examine src and dst ports */
449 		if (m->m_pkthdr.len < off + sizeof(*uhp))
450 			return;
451 
452 		bzero(&uh, sizeof(uh));
453 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
454 
455 		(void) in6_pcbnotify(&udb, sa, uh.uh_dport,
456 				     (struct sockaddr *)ip6cp->ip6c_src,
457 				     uh.uh_sport, cmd, notify);
458 	} else
459 		(void) in6_pcbnotify(&udb, sa, 0,
460 				     (const struct sockaddr *)sa6_src,
461 				     0, cmd, notify);
462 }
463 
464 static int
465 udp6_getcred(SYSCTL_HANDLER_ARGS)
466 {
467 	struct xucred xuc;
468 	struct sockaddr_in6 addrs[2];
469 	struct inpcb *inp;
470 	int error, s;
471 
472 	error = suser(req->td);
473 	if (error)
474 		return (error);
475 
476 	if (req->newlen != sizeof(addrs))
477 		return (EINVAL);
478 	if (req->oldlen != sizeof(struct xucred))
479 		return (EINVAL);
480 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
481 	if (error)
482 		return (error);
483 	s = splnet();
484 	inp = in6_pcblookup_hash(&udbinfo, &addrs[1].sin6_addr,
485 				 addrs[1].sin6_port,
486 				 &addrs[0].sin6_addr, addrs[0].sin6_port,
487 				 1, NULL);
488 	if (!inp || !inp->inp_socket) {
489 		error = ENOENT;
490 		goto out;
491 	}
492 	cru2x(inp->inp_socket->so_cred, &xuc);
493 	error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
494 out:
495 	splx(s);
496 	return (error);
497 }
498 
499 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
500 	    0, 0,
501 	    udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
502 
503 static int
504 udp6_abort(struct socket *so)
505 {
506 	struct inpcb *inp;
507 	int s;
508 
509 	inp = sotoinpcb(so);
510 	if (inp == 0)
511 		return EINVAL;	/* ??? possible? panic instead? */
512 	soisdisconnected(so);
513 	s = splnet();
514 	in6_pcbdetach(inp);
515 	splx(s);
516 	return 0;
517 }
518 
519 static int
520 udp6_attach(struct socket *so, int proto, struct thread *td)
521 {
522 	struct inpcb *inp;
523 	int s, error;
524 
525 	inp = sotoinpcb(so);
526 	if (inp != 0)
527 		return EINVAL;
528 
529 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
530 		error = soreserve(so, udp_sendspace, udp_recvspace);
531 		if (error)
532 			return error;
533 	}
534 	s = splnet();
535 	error = in_pcballoc(so, &udbinfo, td);
536 	splx(s);
537 	if (error)
538 		return error;
539 	inp = (struct inpcb *)so->so_pcb;
540 	inp->inp_vflag |= INP_IPV6;
541 	inp->in6p_hops = -1;	/* use kernel default */
542 	inp->in6p_cksum = -1;	/* just to be sure */
543 	/*
544 	 * XXX: ugly!!
545 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
546 	 * because the socket may be bound to an IPv6 wildcard address,
547 	 * which may match an IPv4-mapped IPv6 address.
548 	 */
549 	inp->inp_ip_ttl = ip_defttl;
550 	return 0;
551 }
552 
553 static int
554 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
555 {
556 	struct inpcb *inp;
557 	int s, error;
558 
559 	inp = sotoinpcb(so);
560 	if (inp == 0)
561 		return EINVAL;
562 
563 	inp->inp_vflag &= ~INP_IPV4;
564 	inp->inp_vflag |= INP_IPV6;
565 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
566 		struct sockaddr_in6 *sin6_p;
567 
568 		sin6_p = (struct sockaddr_in6 *)nam;
569 
570 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
571 			inp->inp_vflag |= INP_IPV4;
572 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
573 			struct sockaddr_in sin;
574 
575 			in6_sin6_2_sin(&sin, sin6_p);
576 			inp->inp_vflag |= INP_IPV4;
577 			inp->inp_vflag &= ~INP_IPV6;
578 			s = splnet();
579 			error = in_pcbbind(inp, (struct sockaddr *)&sin, td);
580 			splx(s);
581 			return error;
582 		}
583 	}
584 
585 	s = splnet();
586 	error = in6_pcbbind(inp, nam, td);
587 	splx(s);
588 	return error;
589 }
590 
591 static int
592 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
593 {
594 	struct inpcb *inp;
595 	int s, error;
596 
597 	inp = sotoinpcb(so);
598 	if (inp == 0)
599 		return EINVAL;
600 
601 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
602 		struct sockaddr_in6 *sin6_p;
603 
604 		sin6_p = (struct sockaddr_in6 *)nam;
605 		if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
606 			struct sockaddr_in sin;
607 
608 			if (inp->inp_faddr.s_addr != INADDR_ANY)
609 				return EISCONN;
610 			in6_sin6_2_sin(&sin, sin6_p);
611 			s = splnet();
612 			error = in_pcbconnect(inp, (struct sockaddr *)&sin, td);
613 			splx(s);
614 			if (error == 0) {
615 				inp->inp_vflag |= INP_IPV4;
616 				inp->inp_vflag &= ~INP_IPV6;
617 				soisconnected(so);
618 			}
619 			return error;
620 		}
621 	}
622 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
623 		return EISCONN;
624 	s = splnet();
625 	error = in6_pcbconnect(inp, nam, td);
626 	splx(s);
627 	if (error == 0) {
628 		if (ip6_mapped_addr_on) { /* should be non mapped addr */
629 			inp->inp_vflag &= ~INP_IPV4;
630 			inp->inp_vflag |= INP_IPV6;
631 		}
632 		soisconnected(so);
633 	}
634 	return error;
635 }
636 
637 static int
638 udp6_detach(struct socket *so)
639 {
640 	struct inpcb *inp;
641 	int s;
642 
643 	inp = sotoinpcb(so);
644 	if (inp == 0)
645 		return EINVAL;
646 	s = splnet();
647 	in6_pcbdetach(inp);
648 	splx(s);
649 	return 0;
650 }
651 
652 static int
653 udp6_disconnect(struct socket *so)
654 {
655 	struct inpcb *inp;
656 	int s;
657 
658 	inp = sotoinpcb(so);
659 	if (inp == 0)
660 		return EINVAL;
661 
662 	if (inp->inp_vflag & INP_IPV4) {
663 		struct pr_usrreqs *pru;
664 
665 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
666 		return ((*pru->pru_disconnect)(so));
667 	}
668 
669 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
670 		return ENOTCONN;
671 
672 	s = splnet();
673 	in6_pcbdisconnect(inp);
674 	inp->in6p_laddr = in6addr_any;
675 	splx(s);
676 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
677 	return 0;
678 }
679 
680 static int
681 udp6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
682 	  struct mbuf *control, struct thread *td)
683 {
684 	struct inpcb *inp;
685 	int error = 0;
686 
687 	inp = sotoinpcb(so);
688 	if (inp == 0) {
689 		error = EINVAL;
690 		goto bad;
691 	}
692 
693 	if (addr) {
694 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
695 			error = EINVAL;
696 			goto bad;
697 		}
698 		if (addr->sa_family != AF_INET6) {
699 			error = EAFNOSUPPORT;
700 			goto bad;
701 		}
702 	}
703 
704 	if (ip6_mapped_addr_on) {
705 		int hasv4addr;
706 		struct sockaddr_in6 *sin6 = 0;
707 
708 		if (addr == 0)
709 			hasv4addr = (inp->inp_vflag & INP_IPV4);
710 		else {
711 			sin6 = (struct sockaddr_in6 *)addr;
712 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
713 				? 1 : 0;
714 		}
715 		if (hasv4addr) {
716 			struct pr_usrreqs *pru;
717 
718 			if (sin6)
719 				in6_sin6_2_sin_in_sock(addr);
720 			pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
721 			error = ((*pru->pru_send)(so, flags, m, addr, control,
722 						  td));
723 			/* addr will just be freed in sendit(). */
724 			return error;
725 		}
726 	}
727 
728 	return udp6_output(inp, m, addr, control, td);
729 
730   bad:
731 	m_freem(m);
732 	return(error);
733 }
734 
735 struct pr_usrreqs udp6_usrreqs = {
736 	udp6_abort, pru_accept_notsupp, udp6_attach, udp6_bind, udp6_connect,
737 	pru_connect2_notsupp, in6_control, udp6_detach, udp6_disconnect,
738 	pru_listen_notsupp, in6_mapped_peeraddr, pru_rcvd_notsupp,
739 	pru_rcvoob_notsupp, udp6_send, pru_sense_null, udp_shutdown,
740 	in6_mapped_sockaddr, sosend, soreceive, sopoll
741 };
742