xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision 74bf4e164ba5851606a27d4feff27717452583e5)
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  * 4. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
62  */
63 
64 #include "opt_inet.h"
65 #include "opt_inet6.h"
66 #include "opt_ipsec.h"
67 
68 #include <sys/param.h>
69 #include <sys/errno.h>
70 #include <sys/kernel.h>
71 #include <sys/lock.h>
72 #include <sys/mbuf.h>
73 #include <sys/proc.h>
74 #include <sys/protosw.h>
75 #include <sys/signalvar.h>
76 #include <sys/socket.h>
77 #include <sys/socketvar.h>
78 #include <sys/stat.h>
79 #include <sys/sx.h>
80 #include <sys/sysctl.h>
81 #include <sys/syslog.h>
82 #include <sys/systm.h>
83 
84 #include <net/if.h>
85 #include <net/if_types.h>
86 #include <net/route.h>
87 
88 #include <netinet/in.h>
89 #include <netinet/in_pcb.h>
90 #include <netinet/in_systm.h>
91 #include <netinet/in_var.h>
92 #include <netinet/ip.h>
93 #include <netinet/ip6.h>
94 #include <netinet/icmp6.h>
95 #include <netinet/ip_var.h>
96 #include <netinet/udp.h>
97 #include <netinet/udp_var.h>
98 #include <netinet6/ip6protosw.h>
99 #include <netinet6/ip6_var.h>
100 #include <netinet6/in6_pcb.h>
101 #include <netinet6/udp6_var.h>
102 
103 #ifdef IPSEC
104 #include <netinet6/ipsec.h>
105 #include <netinet6/ipsec6.h>
106 #endif /* IPSEC */
107 
108 #ifdef FAST_IPSEC
109 #include <netipsec/ipsec.h>
110 #include <netipsec/ipsec6.h>
111 #endif /* FAST_IPSEC */
112 
113 /*
114  * UDP protocol inplementation.
115  * Per RFC 768, August, 1980.
116  */
117 
118 extern	struct protosw inetsw[];
119 static	int udp6_detach __P((struct socket *so));
120 
121 int
122 udp6_input(mp, offp, proto)
123 	struct mbuf **mp;
124 	int *offp, proto;
125 {
126 	struct mbuf *m = *mp, *opts;
127 	register struct ip6_hdr *ip6;
128 	register struct udphdr *uh;
129 	register struct inpcb *in6p;
130 	int off = *offp;
131 	int plen, ulen;
132 	struct sockaddr_in6 fromsa;
133 
134 	opts = NULL;
135 
136 	ip6 = mtod(m, struct ip6_hdr *);
137 
138 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
139 		/* XXX send icmp6 host/port unreach? */
140 		m_freem(m);
141 		return IPPROTO_DONE;
142 	}
143 
144 #ifndef PULLDOWN_TEST
145 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
146 	ip6 = mtod(m, struct ip6_hdr *);
147 	uh = (struct udphdr *)((caddr_t)ip6 + off);
148 #else
149 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
150 	if (!uh)
151 		return IPPROTO_DONE;
152 #endif
153 
154 	udpstat.udps_ipackets++;
155 
156 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
157 	ulen = ntohs((u_short)uh->uh_ulen);
158 
159 	if (plen != ulen) {
160 		udpstat.udps_badlen++;
161 		goto bad;
162 	}
163 
164 	/*
165 	 * Checksum extended UDP header and data.
166 	 */
167 	if (uh->uh_sum == 0) {
168 		udpstat.udps_nosum++;
169 		goto bad;
170 	}
171 	if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
172 		udpstat.udps_badsum++;
173 		goto bad;
174 	}
175 
176 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
177 		struct	inpcb *last;
178 
179 		/*
180 		 * Deliver a multicast datagram to all sockets
181 		 * for which the local and remote addresses and ports match
182 		 * those of the incoming datagram.  This allows more than
183 		 * one process to receive multicasts on the same port.
184 		 * (This really ought to be done for unicast datagrams as
185 		 * well, but that would cause problems with existing
186 		 * applications that open both address-specific sockets and
187 		 * a wildcard socket listening to the same port -- they would
188 		 * end up receiving duplicates of every unicast datagram.
189 		 * Those applications open the multiple sockets to overcome an
190 		 * inadequacy of the UDP socket interface, but for backwards
191 		 * compatibility we avoid the problem here rather than
192 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
193 		 */
194 
195 		/*
196 		 * In a case that laddr should be set to the link-local
197 		 * address (this happens in RIPng), the multicast address
198 		 * specified in the received packet does not match with
199 		 * laddr. To cure this situation, the matching is relaxed
200 		 * if the receiving interface is the same as one specified
201 		 * in the socket and if the destination multicast address
202 		 * matches one of the multicast groups specified in the socket.
203 		 */
204 
205 		/*
206 		 * Construct sockaddr format source address.
207 		 */
208 		init_sin6(&fromsa, m);
209 		fromsa.sin6_port = uh->uh_sport;
210 		/*
211 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
212 		 * We need udphdr for IPsec processing so we do that later.
213 		 */
214 
215 		/*
216 		 * Locate pcb(s) for datagram.
217 		 * (Algorithm copied from raw_intr().)
218 		 */
219 		last = NULL;
220 		LIST_FOREACH(in6p, &udb, inp_list) {
221 			if ((in6p->inp_vflag & INP_IPV6) == 0)
222 				continue;
223 			if (in6p->in6p_lport != uh->uh_dport)
224 				continue;
225 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
226 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
227 							&ip6->ip6_dst))
228 					continue;
229 			}
230 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
231 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
232 							&ip6->ip6_src) ||
233 				    in6p->in6p_fport != uh->uh_sport)
234 					continue;
235 			}
236 
237 			if (last != NULL) {
238 				struct mbuf *n;
239 
240 #if defined(IPSEC) || defined(FAST_IPSEC)
241 				/*
242 				 * Check AH/ESP integrity.
243 				 */
244 				if (ipsec6_in_reject(m, last)) {
245 #ifdef IPSEC
246 					ipsec6stat.in_polvio++;
247 #endif /* IPSEC */
248 					/* do not inject data into pcb */
249 				} else
250 #endif /*IPSEC || FAST_IPSEC*/
251 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
252 					/*
253 					 * KAME NOTE: do not
254 					 * m_copy(m, offset, ...) above.
255 					 * sbappendaddr() expects M_PKTHDR,
256 					 * and m_copy() will copy M_PKTHDR
257 					 * only if offset is 0.
258 					 */
259 					if (last->in6p_flags & IN6P_CONTROLOPTS
260 					    || last->in6p_socket->so_options & SO_TIMESTAMP)
261 						ip6_savecontrol(last, n, &opts);
262 
263 					m_adj(n, off + sizeof(struct udphdr));
264 					if (sbappendaddr(&last->in6p_socket->so_rcv,
265 							(struct sockaddr *)&fromsa,
266 							n, opts) == 0) {
267 						m_freem(n);
268 						if (opts)
269 							m_freem(opts);
270 						udpstat.udps_fullsock++;
271 					} else
272 						sorwakeup(last->in6p_socket);
273 					opts = NULL;
274 				}
275 			}
276 			last = in6p;
277 			/*
278 			 * Don't look for additional matches if this one does
279 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
280 			 * socket options set.  This heuristic avoids searching
281 			 * through all pcbs in the common case of a non-shared
282 			 * port.  It assumes that an application will never
283 			 * clear these options after setting them.
284 			 */
285 			if ((last->in6p_socket->so_options &
286 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
287 				break;
288 		}
289 
290 		if (last == NULL) {
291 			/*
292 			 * No matching pcb found; discard datagram.
293 			 * (No need to send an ICMP Port Unreachable
294 			 * for a broadcast or multicast datgram.)
295 			 */
296 			udpstat.udps_noport++;
297 			udpstat.udps_noportmcast++;
298 			goto bad;
299 		}
300 #if defined(IPSEC) || defined(FAST_IPSEC)
301 		/*
302 		 * Check AH/ESP integrity.
303 		 */
304 		if (ipsec6_in_reject(m, last)) {
305 #ifdef IPSEC
306 			ipsec6stat.in_polvio++;
307 #endif /* IPSEC */
308 			goto bad;
309 		}
310 #endif /*IPSEC || FAST_IPSEC*/
311 		if (last->in6p_flags & IN6P_CONTROLOPTS
312 		    || last->in6p_socket->so_options & SO_TIMESTAMP)
313 			ip6_savecontrol(last, m, &opts);
314 
315 		m_adj(m, off + sizeof(struct udphdr));
316 		if (sbappendaddr(&last->in6p_socket->so_rcv,
317 				(struct sockaddr *)&fromsa,
318 				m, opts) == 0) {
319 			udpstat.udps_fullsock++;
320 			goto bad;
321 		}
322 		sorwakeup(last->in6p_socket);
323 		return IPPROTO_DONE;
324 	}
325 	/*
326 	 * Locate pcb for datagram.
327 	 */
328 	in6p = in6_pcblookup_hash(&udbinfo, &ip6->ip6_src, uh->uh_sport,
329 				  &ip6->ip6_dst, uh->uh_dport, 1,
330 				  m->m_pkthdr.rcvif);
331 	if (in6p == 0) {
332 		if (log_in_vain) {
333 			char buf[INET6_ADDRSTRLEN];
334 
335 			strcpy(buf, ip6_sprintf(&ip6->ip6_dst));
336 			log(LOG_INFO,
337 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
338 			    buf, ntohs(uh->uh_dport),
339 			    ip6_sprintf(&ip6->ip6_src), ntohs(uh->uh_sport));
340 		}
341 		udpstat.udps_noport++;
342 		if (m->m_flags & M_MCAST) {
343 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
344 			udpstat.udps_noportmcast++;
345 			goto bad;
346 		}
347 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
348 		return IPPROTO_DONE;
349 	}
350 #if defined(IPSEC) || defined(FAST_IPSEC)
351 	/*
352 	 * Check AH/ESP integrity.
353 	 */
354 	if (ipsec6_in_reject(m, in6p)) {
355 #ifdef IPSEC
356 		ipsec6stat.in_polvio++;
357 #endif /* IPSEC */
358 		goto bad;
359 	}
360 #endif /*IPSEC || FAST_IPSEC*/
361 
362 	/*
363 	 * Construct sockaddr format source address.
364 	 * Stuff source address and datagram in user buffer.
365 	 */
366 	init_sin6(&fromsa, m);
367 	fromsa.sin6_port = uh->uh_sport;
368 	if (in6p->in6p_flags & IN6P_CONTROLOPTS
369 	    || in6p->in6p_socket->so_options & SO_TIMESTAMP)
370 		ip6_savecontrol(in6p, m, &opts);
371 	m_adj(m, off + sizeof(struct udphdr));
372 	if (sbappendaddr(&in6p->in6p_socket->so_rcv,
373 			(struct sockaddr *)&fromsa, m, opts) == 0) {
374 		udpstat.udps_fullsock++;
375 		goto bad;
376 	}
377 	sorwakeup(in6p->in6p_socket);
378 	return IPPROTO_DONE;
379 bad:
380 	if (m)
381 		m_freem(m);
382 	if (opts)
383 		m_freem(opts);
384 	return IPPROTO_DONE;
385 }
386 
387 void
388 udp6_ctlinput(cmd, sa, d)
389 	int cmd;
390 	struct sockaddr *sa;
391 	void *d;
392 {
393 	struct udphdr uh;
394 	struct ip6_hdr *ip6;
395 	struct mbuf *m;
396 	int off = 0;
397 	struct ip6ctlparam *ip6cp = NULL;
398 	const struct sockaddr_in6 *sa6_src = NULL;
399 	void *cmdarg;
400 	struct inpcb *(*notify) __P((struct inpcb *, int)) = udp_notify;
401 	struct udp_portonly {
402 		u_int16_t uh_sport;
403 		u_int16_t uh_dport;
404 	} *uhp;
405 
406 	if (sa->sa_family != AF_INET6 ||
407 	    sa->sa_len != sizeof(struct sockaddr_in6))
408 		return;
409 
410 	if ((unsigned)cmd >= PRC_NCMDS)
411 		return;
412 	if (PRC_IS_REDIRECT(cmd))
413 		notify = in6_rtchange, d = NULL;
414 	else if (cmd == PRC_HOSTDEAD)
415 		d = NULL;
416 	else if (inet6ctlerrmap[cmd] == 0)
417 		return;
418 
419 	/* if the parameter is from icmp6, decode it. */
420 	if (d != NULL) {
421 		ip6cp = (struct ip6ctlparam *)d;
422 		m = ip6cp->ip6c_m;
423 		ip6 = ip6cp->ip6c_ip6;
424 		off = ip6cp->ip6c_off;
425 		cmdarg = ip6cp->ip6c_cmdarg;
426 		sa6_src = ip6cp->ip6c_src;
427 	} else {
428 		m = NULL;
429 		ip6 = NULL;
430 		cmdarg = NULL;
431 		sa6_src = &sa6_any;
432 	}
433 
434 	if (ip6) {
435 		/*
436 		 * XXX: We assume that when IPV6 is non NULL,
437 		 * M and OFF are valid.
438 		 */
439 
440 		/* check if we can safely examine src and dst ports */
441 		if (m->m_pkthdr.len < off + sizeof(*uhp))
442 			return;
443 
444 		bzero(&uh, sizeof(uh));
445 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
446 
447 		(void) in6_pcbnotify(&udbinfo, sa, uh.uh_dport,
448 				     (struct sockaddr *)ip6cp->ip6c_src,
449 				     uh.uh_sport, cmd, cmdarg, notify);
450 	} else
451 		(void) in6_pcbnotify(&udbinfo, sa, 0,
452 				     (const struct sockaddr *)sa6_src,
453 				     0, cmd, cmdarg, notify);
454 }
455 
456 static int
457 udp6_getcred(SYSCTL_HANDLER_ARGS)
458 {
459 	struct xucred xuc;
460 	struct sockaddr_in6 addrs[2];
461 	struct inpcb *inp;
462 	int error, s;
463 
464 	error = suser(req->td);
465 	if (error)
466 		return (error);
467 
468 	if (req->newlen != sizeof(addrs))
469 		return (EINVAL);
470 	if (req->oldlen != sizeof(struct xucred))
471 		return (EINVAL);
472 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
473 	if (error)
474 		return (error);
475 	s = splnet();
476 	inp = in6_pcblookup_hash(&udbinfo, &addrs[1].sin6_addr,
477 				 addrs[1].sin6_port,
478 				 &addrs[0].sin6_addr, addrs[0].sin6_port,
479 				 1, NULL);
480 	if (!inp || !inp->inp_socket) {
481 		error = ENOENT;
482 		goto out;
483 	}
484 	cru2x(inp->inp_socket->so_cred, &xuc);
485 	error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
486 out:
487 	splx(s);
488 	return (error);
489 }
490 
491 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
492 	    0, 0,
493 	    udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
494 
495 static int
496 udp6_abort(struct socket *so)
497 {
498 	struct inpcb *inp;
499 	int s;
500 
501 	inp = sotoinpcb(so);
502 	if (inp == 0)
503 		return EINVAL;	/* ??? possible? panic instead? */
504 	soisdisconnected(so);
505 	s = splnet();
506 	in6_pcbdetach(inp);
507 	splx(s);
508 	return 0;
509 }
510 
511 static int
512 udp6_attach(struct socket *so, int proto, struct thread *td)
513 {
514 	struct inpcb *inp;
515 	int s, error;
516 
517 	INP_INFO_WLOCK(&udbinfo);
518 	inp = sotoinpcb(so);
519 	if (inp != 0) {
520 		INP_INFO_WUNLOCK(&udbinfo);
521 		return EINVAL;
522 	}
523 
524 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
525 		error = soreserve(so, udp_sendspace, udp_recvspace);
526 		if (error) {
527 			INP_INFO_WUNLOCK(&udbinfo);
528 			return error;
529 		}
530 	}
531 	s = splnet();
532 	error = in_pcballoc(so, &udbinfo, "udp6inp");
533 	splx(s);
534 	if (error) {
535 		INP_INFO_WUNLOCK(&udbinfo);
536 		return error;
537 	}
538 	inp = (struct inpcb *)so->so_pcb;
539 	INP_LOCK(inp);
540 	INP_INFO_WUNLOCK(&udbinfo);
541 	inp->inp_vflag |= INP_IPV6;
542 	if (!ip6_v6only)
543 		inp->inp_vflag |= INP_IPV4;
544 	inp->in6p_hops = -1;	/* use kernel default */
545 	inp->in6p_cksum = -1;	/* just to be sure */
546 	/*
547 	 * XXX: ugly!!
548 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
549 	 * because the socket may be bound to an IPv6 wildcard address,
550 	 * which may match an IPv4-mapped IPv6 address.
551 	 */
552 	inp->inp_ip_ttl = ip_defttl;
553 	INP_UNLOCK(inp);
554 	return 0;
555 }
556 
557 static int
558 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
559 {
560 	struct inpcb *inp;
561 	int s, error;
562 
563 	INP_INFO_WLOCK(&udbinfo);
564 	inp = sotoinpcb(so);
565 	if (inp == 0) {
566 		INP_INFO_WUNLOCK(&udbinfo);
567 		return EINVAL;
568 	}
569 	INP_LOCK(inp);
570 
571 	inp->inp_vflag &= ~INP_IPV4;
572 	inp->inp_vflag |= INP_IPV6;
573 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
574 		struct sockaddr_in6 *sin6_p;
575 
576 		sin6_p = (struct sockaddr_in6 *)nam;
577 
578 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
579 			inp->inp_vflag |= INP_IPV4;
580 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
581 			struct sockaddr_in sin;
582 
583 			in6_sin6_2_sin(&sin, sin6_p);
584 			inp->inp_vflag |= INP_IPV4;
585 			inp->inp_vflag &= ~INP_IPV6;
586 			s = splnet();
587 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
588 			    td->td_ucred);
589 			goto out;
590 		}
591 	}
592 
593 	s = splnet();
594 	error = in6_pcbbind(inp, nam, td->td_ucred);
595 out:
596 	INP_UNLOCK(inp);
597 	INP_INFO_WUNLOCK(&udbinfo);
598 	splx(s);
599 	return error;
600 }
601 
602 static int
603 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
604 {
605 	struct inpcb *inp;
606 	int s, error;
607 
608 	INP_INFO_WLOCK(&udbinfo);
609 	inp = sotoinpcb(so);
610 	if (inp == 0) {
611 		INP_INFO_WUNLOCK(&udbinfo);
612 		return EINVAL;
613 	}
614 	INP_LOCK(inp);
615 
616 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
617 		struct sockaddr_in6 *sin6_p;
618 
619 		sin6_p = (struct sockaddr_in6 *)nam;
620 		if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
621 			struct sockaddr_in sin;
622 
623 			if (inp->inp_faddr.s_addr != INADDR_ANY)
624 				return EISCONN;
625 			in6_sin6_2_sin(&sin, sin6_p);
626 			s = splnet();
627 			error = in_pcbconnect(inp, (struct sockaddr *)&sin,
628 			    td->td_ucred);
629 			splx(s);
630 			if (error == 0) {
631 				inp->inp_vflag |= INP_IPV4;
632 				inp->inp_vflag &= ~INP_IPV6;
633 				soisconnected(so);
634 			}
635 			goto out;
636 		}
637 	}
638 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
639 		error = EISCONN;
640 		goto out;
641 	}
642 	s = splnet();
643 	error = in6_pcbconnect(inp, nam, td->td_ucred);
644 	splx(s);
645 	if (error == 0) {
646 		if (!ip6_v6only) { /* should be non mapped addr */
647 			inp->inp_vflag &= ~INP_IPV4;
648 			inp->inp_vflag |= INP_IPV6;
649 		}
650 		soisconnected(so);
651 	}
652 out:
653 	INP_UNLOCK(inp);
654 	INP_INFO_WUNLOCK(&udbinfo);
655 	return error;
656 }
657 
658 static int
659 udp6_detach(struct socket *so)
660 {
661 	struct inpcb *inp;
662 	int s;
663 
664 	INP_INFO_WLOCK(&udbinfo);
665 	inp = sotoinpcb(so);
666 	if (inp == 0) {
667 		INP_INFO_WUNLOCK(&udbinfo);
668 		return EINVAL;
669 	}
670 	INP_LOCK(inp);
671 	s = splnet();
672 	in6_pcbdetach(inp);
673 	splx(s);
674 	INP_INFO_WUNLOCK(&udbinfo);
675 	return 0;
676 }
677 
678 static int
679 udp6_disconnect(struct socket *so)
680 {
681 	struct inpcb *inp;
682 	int error, s;
683 
684 	INP_INFO_WLOCK(&udbinfo);
685 	inp = sotoinpcb(so);
686 	if (inp == 0) {
687 		INP_INFO_WUNLOCK(&udbinfo);
688 		return EINVAL;
689 	}
690 	INP_LOCK(inp);
691 
692 #ifdef INET
693 	if (inp->inp_vflag & INP_IPV4) {
694 		struct pr_usrreqs *pru;
695 
696 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
697 		error = (*pru->pru_disconnect)(so);
698 		goto out;
699 	}
700 #endif
701 
702 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
703 		error = ENOTCONN;
704 		goto out;
705 	}
706 
707 	s = splnet();
708 	in6_pcbdisconnect(inp);
709 	inp->in6p_laddr = in6addr_any;
710 	splx(s);
711 	/* XXXRW: so_state locking? */
712 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
713 out:
714 	INP_UNLOCK(inp);
715 	INP_INFO_WUNLOCK(&udbinfo);
716 	return 0;
717 }
718 
719 static int
720 udp6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
721 	  struct mbuf *control, struct thread *td)
722 {
723 	struct inpcb *inp;
724 	int error = 0;
725 
726 	INP_INFO_WLOCK(&udbinfo);
727 	inp = sotoinpcb(so);
728 	if (inp == 0) {
729 		INP_INFO_WUNLOCK(&udbinfo);
730 		m_freem(m);
731 		return EINVAL;
732 	}
733 	INP_LOCK(inp);
734 
735 	if (addr) {
736 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
737 			error = EINVAL;
738 			goto bad;
739 		}
740 		if (addr->sa_family != AF_INET6) {
741 			error = EAFNOSUPPORT;
742 			goto bad;
743 		}
744 	}
745 
746 #ifdef INET
747 	if (!ip6_v6only) {
748 		int hasv4addr;
749 		struct sockaddr_in6 *sin6 = 0;
750 
751 		if (addr == 0)
752 			hasv4addr = (inp->inp_vflag & INP_IPV4);
753 		else {
754 			sin6 = (struct sockaddr_in6 *)addr;
755 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
756 				? 1 : 0;
757 		}
758 		if (hasv4addr) {
759 			struct pr_usrreqs *pru;
760 
761 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
762 				/*
763 				 * since a user of this socket set the
764 				 * IPV6_V6ONLY flag, we discard this
765 				 * datagram destined to a v4 addr.
766 				 */
767 				error = EINVAL;
768 				goto out;
769 			}
770 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
771 			    !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
772 				/*
773 				 * when remote addr is IPv4-mapped
774 				 * address, local addr should not be
775 				 * an IPv6 address; since you cannot
776 				 * determine how to map IPv6 source
777 				 * address to IPv4.
778 				 */
779 				error = EINVAL;
780 				goto out;
781 			}
782 			if (sin6)
783 				in6_sin6_2_sin_in_sock(addr);
784 			pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
785 			error = ((*pru->pru_send)(so, flags, m, addr, control,
786 						  td));
787 			/* addr will just be freed in sendit(). */
788 			goto out;
789 		}
790 	}
791 #endif
792 
793 	error = udp6_output(inp, m, addr, control, td);
794 out:
795 	INP_UNLOCK(inp);
796 	INP_INFO_WUNLOCK(&udbinfo);
797 	return error;
798 
799   bad:
800 	INP_UNLOCK(inp);
801 	INP_INFO_WUNLOCK(&udbinfo);
802 	m_freem(m);
803 	return (error);
804 }
805 
806 struct pr_usrreqs udp6_usrreqs = {
807 	udp6_abort, pru_accept_notsupp, udp6_attach, udp6_bind, udp6_connect,
808 	pru_connect2_notsupp, in6_control, udp6_detach, udp6_disconnect,
809 	pru_listen_notsupp, in6_mapped_peeraddr, pru_rcvd_notsupp,
810 	pru_rcvoob_notsupp, udp6_send, pru_sense_null, udp_shutdown,
811 	in6_mapped_sockaddr, sosend, soreceive, sopoll, in_pcbsosetlabel
812 };
813