xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision adc56f5a383771f594829b7db9c263b6f0dcf1bd)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * Copyright (c) 2010-2011 Juniper Networks, Inc.
6  * Copyright (c) 2014 Kevin Lo
7  * All rights reserved.
8  *
9  * Portions of this software were developed by Robert N. M. Watson under
10  * contract to Juniper Networks, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the project nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	$KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei Exp $
37  *	$KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $
38  */
39 
40 /*-
41  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
42  *	The Regents of the University of California.
43  * All rights reserved.
44  *
45  * Redistribution and use in source and binary forms, with or without
46  * modification, are permitted provided that the following conditions
47  * are met:
48  * 1. Redistributions of source code must retain the above copyright
49  *    notice, this list of conditions and the following disclaimer.
50  * 2. Redistributions in binary form must reproduce the above copyright
51  *    notice, this list of conditions and the following disclaimer in the
52  *    documentation and/or other materials provided with the distribution.
53  * 3. Neither the name of the University nor the names of its contributors
54  *    may be used to endorse or promote products derived from this software
55  *    without specific prior written permission.
56  *
57  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
58  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
59  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
60  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
61  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
62  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
63  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
64  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
65  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
66  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67  * SUCH DAMAGE.
68  *
69  *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
70  */
71 
72 #include <sys/cdefs.h>
73 __FBSDID("$FreeBSD$");
74 
75 #include "opt_inet.h"
76 #include "opt_inet6.h"
77 #include "opt_ipsec.h"
78 #include "opt_rss.h"
79 
80 #include <sys/param.h>
81 #include <sys/jail.h>
82 #include <sys/kernel.h>
83 #include <sys/lock.h>
84 #include <sys/mbuf.h>
85 #include <sys/priv.h>
86 #include <sys/proc.h>
87 #include <sys/protosw.h>
88 #include <sys/sdt.h>
89 #include <sys/signalvar.h>
90 #include <sys/socket.h>
91 #include <sys/socketvar.h>
92 #include <sys/sx.h>
93 #include <sys/sysctl.h>
94 #include <sys/syslog.h>
95 #include <sys/systm.h>
96 
97 #include <net/if.h>
98 #include <net/if_var.h>
99 #include <net/if_types.h>
100 #include <net/route.h>
101 #include <net/rss_config.h>
102 
103 #include <netinet/in.h>
104 #include <netinet/in_kdtrace.h>
105 #include <netinet/in_pcb.h>
106 #include <netinet/in_systm.h>
107 #include <netinet/in_var.h>
108 #include <netinet/ip.h>
109 #include <netinet/ip6.h>
110 #include <netinet/icmp6.h>
111 #include <netinet/ip_var.h>
112 #include <netinet/udp.h>
113 #include <netinet/udp_var.h>
114 #include <netinet/udplite.h>
115 
116 #include <netinet6/ip6protosw.h>
117 #include <netinet6/ip6_var.h>
118 #include <netinet6/in6_pcb.h>
119 #include <netinet6/in6_rss.h>
120 #include <netinet6/udp6_var.h>
121 #include <netinet6/scope6_var.h>
122 
123 #include <netipsec/ipsec_support.h>
124 
125 #include <security/mac/mac_framework.h>
126 
127 /*
128  * UDP protocol implementation.
129  * Per RFC 768, August, 1980.
130  */
131 
132 extern struct protosw	inetsw[];
133 static void		udp6_detach(struct socket *so);
134 
135 static int
136 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
137     struct sockaddr_in6 *fromsa)
138 {
139 	struct socket *so;
140 	struct mbuf *opts = NULL, *tmp_opts;
141 	struct udpcb *up;
142 
143 	INP_LOCK_ASSERT(inp);
144 
145 	/*
146 	 * Engage the tunneling protocol.
147 	 */
148 	up = intoudpcb(inp);
149 	if (up->u_tun_func != NULL) {
150 		in_pcbref(inp);
151 		INP_RUNLOCK(inp);
152 		(*up->u_tun_func)(n, off, inp, (struct sockaddr *)&fromsa[0],
153 		    up->u_tun_ctx);
154 		INP_RLOCK(inp);
155 		return (in_pcbrele_rlocked(inp));
156 	}
157 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
158 	/* Check AH/ESP integrity. */
159 	if (IPSEC_ENABLED(ipv6)) {
160 		if (IPSEC_CHECK_POLICY(ipv6, n, inp) != 0) {
161 			m_freem(n);
162 			return (0);
163 		}
164 	}
165 #endif /* IPSEC */
166 #ifdef MAC
167 	if (mac_inpcb_check_deliver(inp, n) != 0) {
168 		m_freem(n);
169 		return (0);
170 	}
171 #endif
172 	opts = NULL;
173 	if (inp->inp_flags & INP_CONTROLOPTS ||
174 	    inp->inp_socket->so_options & SO_TIMESTAMP)
175 		ip6_savecontrol(inp, n, &opts);
176 	if ((inp->inp_vflag & INP_IPV6) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
177 		tmp_opts = sbcreatecontrol((caddr_t)&fromsa[1],
178                         sizeof(struct sockaddr_in6), IPV6_ORIGDSTADDR, IPPROTO_IPV6);
179                 if (tmp_opts) {
180                         if (opts) {
181                                 tmp_opts->m_next = opts;
182                                 opts = tmp_opts;
183                         } else
184                                 opts = tmp_opts;
185                 }
186 
187 	}
188 	m_adj(n, off + sizeof(struct udphdr));
189 
190 	so = inp->inp_socket;
191 	SOCKBUF_LOCK(&so->so_rcv);
192 	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&fromsa[0], n,
193 	    opts) == 0) {
194 		SOCKBUF_UNLOCK(&so->so_rcv);
195 		m_freem(n);
196 		if (opts)
197 			m_freem(opts);
198 		UDPSTAT_INC(udps_fullsock);
199 	} else
200 		sorwakeup_locked(so);
201 	return (0);
202 }
203 
204 int
205 udp6_input(struct mbuf **mp, int *offp, int proto)
206 {
207 	struct mbuf *m = *mp;
208 	struct ifnet *ifp;
209 	struct ip6_hdr *ip6;
210 	struct udphdr *uh;
211 	struct inpcb *inp;
212 	struct inpcbinfo *pcbinfo;
213 	struct udpcb *up;
214 	int off = *offp;
215 	int cscov_partial;
216 	int plen, ulen;
217 	struct sockaddr_in6 fromsa[2];
218 	struct m_tag *fwd_tag;
219 	uint16_t uh_sum;
220 	uint8_t nxt;
221 
222 	NET_EPOCH_ASSERT();
223 
224 	ifp = m->m_pkthdr.rcvif;
225 
226 	if (m->m_len < off + sizeof(struct udphdr)) {
227 		m = m_pullup(m, off + sizeof(struct udphdr));
228 		if (m == NULL) {
229 			IP6STAT_INC(ip6s_exthdrtoolong);
230 			*mp = NULL;
231 			return (IPPROTO_DONE);
232 		}
233 	}
234 	ip6 = mtod(m, struct ip6_hdr *);
235 	uh = (struct udphdr *)((caddr_t)ip6 + off);
236 
237 	UDPSTAT_INC(udps_ipackets);
238 
239 	/*
240 	 * Destination port of 0 is illegal, based on RFC768.
241 	 */
242 	if (uh->uh_dport == 0)
243 		goto badunlocked;
244 
245 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
246 	ulen = ntohs((u_short)uh->uh_ulen);
247 
248 	nxt = proto;
249 	cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
250 	if (nxt == IPPROTO_UDPLITE) {
251 		/* Zero means checksum over the complete packet. */
252 		if (ulen == 0)
253 			ulen = plen;
254 		if (ulen == plen)
255 			cscov_partial = 0;
256 		if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
257 			/* XXX: What is the right UDPLite MIB counter? */
258 			goto badunlocked;
259 		}
260 		if (uh->uh_sum == 0) {
261 			/* XXX: What is the right UDPLite MIB counter? */
262 			goto badunlocked;
263 		}
264 	} else {
265 		if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
266 			UDPSTAT_INC(udps_badlen);
267 			goto badunlocked;
268 		}
269 		if (uh->uh_sum == 0) {
270 			UDPSTAT_INC(udps_nosum);
271 			goto badunlocked;
272 		}
273 	}
274 
275 	if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
276 	    !cscov_partial) {
277 		if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
278 			uh_sum = m->m_pkthdr.csum_data;
279 		else
280 			uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
281 			    m->m_pkthdr.csum_data);
282 		uh_sum ^= 0xffff;
283 	} else
284 		uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
285 
286 	if (uh_sum != 0) {
287 		UDPSTAT_INC(udps_badsum);
288 		goto badunlocked;
289 	}
290 
291 	/*
292 	 * Construct sockaddr format source address.
293 	 */
294 	init_sin6(&fromsa[0], m, 0);
295 	fromsa[0].sin6_port = uh->uh_sport;
296 	init_sin6(&fromsa[1], m, 1);
297 	fromsa[1].sin6_port = uh->uh_dport;
298 
299 	pcbinfo = udp_get_inpcbinfo(nxt);
300 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
301 		struct inpcb *last;
302 		struct inpcbhead *pcblist;
303 		struct ip6_moptions *imo;
304 
305 		/*
306 		 * In the event that laddr should be set to the link-local
307 		 * address (this happens in RIPng), the multicast address
308 		 * specified in the received packet will not match laddr.  To
309 		 * handle this situation, matching is relaxed if the
310 		 * receiving interface is the same as one specified in the
311 		 * socket and if the destination multicast address matches
312 		 * one of the multicast groups specified in the socket.
313 		 */
314 
315 		/*
316 		 * KAME note: traditionally we dropped udpiphdr from mbuf
317 		 * here.  We need udphdr for IPsec processing so we do that
318 		 * later.
319 		 */
320 		pcblist = udp_get_pcblist(nxt);
321 		last = NULL;
322 		CK_LIST_FOREACH(inp, pcblist, inp_list) {
323 			if ((inp->inp_vflag & INP_IPV6) == 0)
324 				continue;
325 			if (inp->inp_lport != uh->uh_dport)
326 				continue;
327 			if (inp->inp_fport != 0 &&
328 			    inp->inp_fport != uh->uh_sport)
329 				continue;
330 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
331 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
332 							&ip6->ip6_dst))
333 					continue;
334 			}
335 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
336 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
337 							&ip6->ip6_src) ||
338 				    inp->inp_fport != uh->uh_sport)
339 					continue;
340 			}
341 
342 			/*
343 			 * XXXRW: Because we weren't holding either the inpcb
344 			 * or the hash lock when we checked for a match
345 			 * before, we should probably recheck now that the
346 			 * inpcb lock is (supposed to be) held.
347 			 */
348 
349 			/*
350 			 * Handle socket delivery policy for any-source
351 			 * and source-specific multicast. [RFC3678]
352 			 */
353 			imo = inp->in6p_moptions;
354 			if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
355 				struct sockaddr_in6	 mcaddr;
356 				int			 blocked;
357 
358 				INP_RLOCK(inp);
359 				if (__predict_false(inp->inp_flags2 & INP_FREED)) {
360 					INP_RUNLOCK(inp);
361 					continue;
362 				}
363 
364 				bzero(&mcaddr, sizeof(struct sockaddr_in6));
365 				mcaddr.sin6_len = sizeof(struct sockaddr_in6);
366 				mcaddr.sin6_family = AF_INET6;
367 				mcaddr.sin6_addr = ip6->ip6_dst;
368 
369 				blocked = im6o_mc_filter(imo, ifp,
370 					(struct sockaddr *)&mcaddr,
371 					(struct sockaddr *)&fromsa[0]);
372 				if (blocked != MCAST_PASS) {
373 					if (blocked == MCAST_NOTGMEMBER)
374 						IP6STAT_INC(ip6s_notmember);
375 					if (blocked == MCAST_NOTSMEMBER ||
376 					    blocked == MCAST_MUTED)
377 						UDPSTAT_INC(udps_filtermcast);
378 					INP_RUNLOCK(inp); /* XXX */
379 					continue;
380 				}
381 
382 				INP_RUNLOCK(inp);
383 			}
384 			if (last != NULL) {
385 				struct mbuf *n;
386 
387 				if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) !=
388 				    NULL) {
389 					INP_RLOCK(last);
390 					if (__predict_true(last->inp_flags2 & INP_FREED) == 0) {
391 						if (nxt == IPPROTO_UDPLITE)
392 							UDPLITE_PROBE(receive, NULL, last,
393 							    ip6, last, uh);
394 						else
395 							UDP_PROBE(receive, NULL, last,
396 							    ip6, last, uh);
397 						if (udp6_append(last, n, off, fromsa)) {
398 							/* XXX-BZ do we leak m here? */
399 							*mp = NULL;
400 							return (IPPROTO_DONE);
401 						}
402 					}
403 					INP_RUNLOCK(last);
404 				}
405 			}
406 			last = inp;
407 			/*
408 			 * Don't look for additional matches if this one does
409 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
410 			 * socket options set.  This heuristic avoids
411 			 * searching through all pcbs in the common case of a
412 			 * non-shared port.  It assumes that an application
413 			 * will never clear these options after setting them.
414 			 */
415 			if ((last->inp_socket->so_options &
416 			     (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0)
417 				break;
418 		}
419 
420 		if (last == NULL) {
421 			/*
422 			 * No matching pcb found; discard datagram.  (No need
423 			 * to send an ICMP Port Unreachable for a broadcast
424 			 * or multicast datgram.)
425 			 */
426 			UDPSTAT_INC(udps_noport);
427 			UDPSTAT_INC(udps_noportmcast);
428 			goto badunlocked;
429 		}
430 		INP_RLOCK(last);
431 		if (__predict_true(last->inp_flags2 & INP_FREED) == 0) {
432 			if (nxt == IPPROTO_UDPLITE)
433 				UDPLITE_PROBE(receive, NULL, last, ip6, last, uh);
434 			else
435 				UDP_PROBE(receive, NULL, last, ip6, last, uh);
436 			if (udp6_append(last, m, off, fromsa) == 0)
437 				INP_RUNLOCK(last);
438 		} else
439 			INP_RUNLOCK(last);
440 		*mp = NULL;
441 		return (IPPROTO_DONE);
442 	}
443 	/*
444 	 * Locate pcb for datagram.
445 	 */
446 
447 	/*
448 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
449 	 */
450 	if ((m->m_flags & M_IP6_NEXTHOP) &&
451 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
452 		struct sockaddr_in6 *next_hop6;
453 
454 		next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
455 
456 		/*
457 		 * Transparently forwarded. Pretend to be the destination.
458 		 * Already got one like this?
459 		 */
460 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
461 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
462 		    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
463 		if (!inp) {
464 			/*
465 			 * It's new.  Try to find the ambushing socket.
466 			 * Because we've rewritten the destination address,
467 			 * any hardware-generated hash is ignored.
468 			 */
469 			inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
470 			    uh->uh_sport, &next_hop6->sin6_addr,
471 			    next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
472 			    uh->uh_dport, INPLOOKUP_WILDCARD |
473 			    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
474 		}
475 		/* Remove the tag from the packet. We don't need it anymore. */
476 		m_tag_delete(m, fwd_tag);
477 		m->m_flags &= ~M_IP6_NEXTHOP;
478 	} else
479 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
480 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
481 		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
482 		    m->m_pkthdr.rcvif, m);
483 	if (inp == NULL) {
484 		if (udp_log_in_vain) {
485 			char ip6bufs[INET6_ADDRSTRLEN];
486 			char ip6bufd[INET6_ADDRSTRLEN];
487 
488 			log(LOG_INFO,
489 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
490 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
491 			    ntohs(uh->uh_dport),
492 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
493 			    ntohs(uh->uh_sport));
494 		}
495 		if (nxt == IPPROTO_UDPLITE)
496 			UDPLITE_PROBE(receive, NULL, NULL, ip6, NULL, uh);
497 		else
498 			UDP_PROBE(receive, NULL, NULL, ip6, NULL, uh);
499 		UDPSTAT_INC(udps_noport);
500 		if (m->m_flags & M_MCAST) {
501 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
502 			UDPSTAT_INC(udps_noportmcast);
503 			goto badunlocked;
504 		}
505 		if (V_udp_blackhole)
506 			goto badunlocked;
507 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
508 		*mp = NULL;
509 		return (IPPROTO_DONE);
510 	}
511 	INP_RLOCK_ASSERT(inp);
512 	up = intoudpcb(inp);
513 	if (cscov_partial) {
514 		if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
515 			INP_RUNLOCK(inp);
516 			m_freem(m);
517 			*mp = NULL;
518 			return (IPPROTO_DONE);
519 		}
520 	}
521 	if (nxt == IPPROTO_UDPLITE)
522 		UDPLITE_PROBE(receive, NULL, inp, ip6, inp, uh);
523 	else
524 		UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
525 	if (udp6_append(inp, m, off, fromsa) == 0)
526 		INP_RUNLOCK(inp);
527 	*mp = NULL;
528 	return (IPPROTO_DONE);
529 
530 badunlocked:
531 	if (m)
532 		m_freem(m);
533 	*mp = NULL;
534 	return (IPPROTO_DONE);
535 }
536 
537 static void
538 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
539     struct inpcbinfo *pcbinfo)
540 {
541 	struct udphdr uh;
542 	struct ip6_hdr *ip6;
543 	struct mbuf *m;
544 	int off = 0;
545 	struct ip6ctlparam *ip6cp = NULL;
546 	const struct sockaddr_in6 *sa6_src = NULL;
547 	void *cmdarg;
548 	struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
549 	struct udp_portonly {
550 		u_int16_t uh_sport;
551 		u_int16_t uh_dport;
552 	} *uhp;
553 
554 	if (sa->sa_family != AF_INET6 ||
555 	    sa->sa_len != sizeof(struct sockaddr_in6))
556 		return;
557 
558 	if ((unsigned)cmd >= PRC_NCMDS)
559 		return;
560 	if (PRC_IS_REDIRECT(cmd))
561 		notify = in6_rtchange, d = NULL;
562 	else if (cmd == PRC_HOSTDEAD)
563 		d = NULL;
564 	else if (inet6ctlerrmap[cmd] == 0)
565 		return;
566 
567 	/* if the parameter is from icmp6, decode it. */
568 	if (d != NULL) {
569 		ip6cp = (struct ip6ctlparam *)d;
570 		m = ip6cp->ip6c_m;
571 		ip6 = ip6cp->ip6c_ip6;
572 		off = ip6cp->ip6c_off;
573 		cmdarg = ip6cp->ip6c_cmdarg;
574 		sa6_src = ip6cp->ip6c_src;
575 	} else {
576 		m = NULL;
577 		ip6 = NULL;
578 		cmdarg = NULL;
579 		sa6_src = &sa6_any;
580 	}
581 
582 	if (ip6) {
583 		/*
584 		 * XXX: We assume that when IPV6 is non NULL,
585 		 * M and OFF are valid.
586 		 */
587 
588 		/* Check if we can safely examine src and dst ports. */
589 		if (m->m_pkthdr.len < off + sizeof(*uhp))
590 			return;
591 
592 		bzero(&uh, sizeof(uh));
593 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
594 
595 		if (!PRC_IS_REDIRECT(cmd)) {
596 			/* Check to see if its tunneled */
597 			struct inpcb *inp;
598 			inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_dst,
599 			    uh.uh_dport, &ip6->ip6_src, uh.uh_sport,
600 			    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
601 			    m->m_pkthdr.rcvif, m);
602 			if (inp != NULL) {
603 				struct udpcb *up;
604 
605 				up = intoudpcb(inp);
606 				if (up->u_icmp_func) {
607 					/* Yes it is. */
608 					INP_RUNLOCK(inp);
609 					(*up->u_icmp_func)(cmd, (struct sockaddr *)ip6cp->ip6c_src,
610 					      d, up->u_tun_ctx);
611 					return;
612 				} else {
613 					/* Can't find it. */
614 					INP_RUNLOCK(inp);
615 				}
616 			}
617 		}
618 		(void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
619 		    (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
620 		    cmdarg, notify);
621 	} else
622 		(void)in6_pcbnotify(pcbinfo, sa, 0,
623 		    (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
624 }
625 
626 void
627 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
628 {
629 
630 	return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
631 }
632 
633 void
634 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
635 {
636 
637 	return (udp6_common_ctlinput(cmd, sa, d, &V_ulitecbinfo));
638 }
639 
640 static int
641 udp6_getcred(SYSCTL_HANDLER_ARGS)
642 {
643 	struct xucred xuc;
644 	struct sockaddr_in6 addrs[2];
645 	struct epoch_tracker et;
646 	struct inpcb *inp;
647 	int error;
648 
649 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
650 	if (error)
651 		return (error);
652 
653 	if (req->newlen != sizeof(addrs))
654 		return (EINVAL);
655 	if (req->oldlen != sizeof(struct xucred))
656 		return (EINVAL);
657 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
658 	if (error)
659 		return (error);
660 	if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
661 	    (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
662 		return (error);
663 	}
664 	NET_EPOCH_ENTER(et);
665 	inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
666 	    addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
667 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
668 	NET_EPOCH_EXIT(et);
669 	if (inp != NULL) {
670 		INP_RLOCK_ASSERT(inp);
671 		if (inp->inp_socket == NULL)
672 			error = ENOENT;
673 		if (error == 0)
674 			error = cr_canseesocket(req->td->td_ucred,
675 			    inp->inp_socket);
676 		if (error == 0)
677 			cru2x(inp->inp_cred, &xuc);
678 		INP_RUNLOCK(inp);
679 	} else
680 		error = ENOENT;
681 	if (error == 0)
682 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
683 	return (error);
684 }
685 
686 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
687     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
688 
689 static int
690 udp6_output(struct socket *so, int flags_arg, struct mbuf *m,
691     struct sockaddr *addr6, struct mbuf *control, struct thread *td)
692 {
693 	struct inpcb *inp;
694 	struct ip6_hdr *ip6;
695 	struct udphdr *udp6;
696 	struct in6_addr *laddr, *faddr, in6a;
697 	struct ip6_pktopts *optp, opt;
698 	struct sockaddr_in6 *sin6, tmp;
699 	struct epoch_tracker et;
700 	int cscov_partial, error, flags, hlen, scope_ambiguous;
701 	u_int32_t ulen, plen;
702 	uint16_t cscov;
703 	u_short fport;
704 	uint8_t nxt;
705 
706 	/* addr6 has been validated in udp6_send(). */
707 	sin6 = (struct sockaddr_in6 *)addr6;
708 
709 	/*
710 	 * In contrast to to IPv4 we do not validate the max. packet length
711 	 * here due to IPv6 Jumbograms (RFC2675).
712 	 */
713 
714 	scope_ambiguous = 0;
715 	if (sin6) {
716 		/* Protect *addr6 from overwrites. */
717 		tmp = *sin6;
718 		sin6 = &tmp;
719 
720 		/*
721 		 * Application should provide a proper zone ID or the use of
722 		 * default zone IDs should be enabled.  Unfortunately, some
723 		 * applications do not behave as it should, so we need a
724 		 * workaround.  Even if an appropriate ID is not determined,
725 		 * we'll see if we can determine the outgoing interface.  If we
726 		 * can, determine the zone ID based on the interface below.
727 		 */
728 		if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
729 			scope_ambiguous = 1;
730 		if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0) {
731 			if (control)
732 				m_freem(control);
733 			m_freem(m);
734 			return (error);
735 		}
736 	}
737 
738 	inp = sotoinpcb(so);
739 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
740 	/*
741 	 * In the following cases we want a write lock on the inp for either
742 	 * local operations or for possible route cache updates in the IPv6
743 	 * output path:
744 	 * - on connected sockets (sin6 is NULL) for route cache updates,
745 	 * - when we are not bound to an address and source port (it is
746 	 *   in6_pcbsetport() which will require the write lock).
747 	 *
748 	 * We check the inp fields before actually locking the inp, so
749 	 * here exists a race, and we may WLOCK the inp and end with already
750 	 * bound one by other thread. This is fine.
751 	 */
752 	if (sin6 == NULL || (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
753 	    inp->inp_lport == 0))
754 		INP_WLOCK(inp);
755 	else
756 		INP_RLOCK(inp);
757 
758 	nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
759 	    IPPROTO_UDP : IPPROTO_UDPLITE;
760 
761 #ifdef INET
762 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
763 		int hasv4addr;
764 
765 		if (sin6 == NULL)
766 			hasv4addr = (inp->inp_vflag & INP_IPV4);
767 		else
768 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
769 			    ? 1 : 0;
770 		if (hasv4addr) {
771 			struct pr_usrreqs *pru;
772 
773 			/*
774 			 * XXXRW: We release UDP-layer locks before calling
775 			 * udp_send() in order to avoid recursion.  However,
776 			 * this does mean there is a short window where inp's
777 			 * fields are unstable.  Could this lead to a
778 			 * potential race in which the factors causing us to
779 			 * select the UDPv4 output routine are invalidated?
780 			 */
781 			INP_UNLOCK(inp);
782 			if (sin6)
783 				in6_sin6_2_sin_in_sock((struct sockaddr *)sin6);
784 			pru = inetsw[ip_protox[nxt]].pr_usrreqs;
785 			/* addr will just be freed in sendit(). */
786 			return ((*pru->pru_send)(so, flags_arg, m,
787 			    (struct sockaddr *)sin6, control, td));
788 		}
789 	} else
790 #endif
791 	if (sin6 && IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
792 		/*
793 		 * Given this is either an IPv6-only socket or no INET is
794 		 * supported we will fail the send if the given destination
795 		 * address is a v4mapped address.
796 		 *
797 		 * XXXGL: do we leak m and control?
798 		 */
799 		INP_UNLOCK(inp);
800 		return (EINVAL);
801 	}
802 
803 	if (control) {
804 		if ((error = ip6_setpktopts(control, &opt,
805 		    inp->in6p_outputopts, td->td_ucred, nxt)) != 0) {
806 			INP_UNLOCK(inp);
807 			ip6_clearpktopts(&opt, -1);
808 			if (control)
809 				m_freem(control);
810 			m_freem(m);
811 			return (error);
812 		}
813 		optp = &opt;
814 	} else
815 		optp = inp->in6p_outputopts;
816 
817 	NET_EPOCH_ENTER(et);
818 	if (sin6) {
819 
820 		/*
821 		 * Since we saw no essential reason for calling in_pcbconnect,
822 		 * we get rid of such kind of logic, and call in6_selectsrc
823 		 * and in6_pcbsetport in order to fill in the local address
824 		 * and the local port.
825 		 */
826 		if (sin6->sin6_port == 0) {
827 			error = EADDRNOTAVAIL;
828 			goto release;
829 		}
830 
831 		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
832 			/* how about ::ffff:0.0.0.0 case? */
833 			error = EISCONN;
834 			goto release;
835 		}
836 
837 		/*
838 		 * Given we handle the v4mapped case in the INET block above
839 		 * assert here that it must not happen anymore.
840 		 */
841 		KASSERT(!IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr),
842 		    ("%s: sin6(%p)->sin6_addr is v4mapped which we "
843 		    "should have handled.", __func__, sin6));
844 
845 		/* This only requires read-locking. */
846 		error = in6_selectsrc_socket(sin6, optp, inp,
847 		    td->td_ucred, scope_ambiguous, &in6a, NULL);
848 		if (error)
849 			goto release;
850 		laddr = &in6a;
851 
852 		if (inp->inp_lport == 0) {
853 			struct inpcbinfo *pcbinfo;
854 
855 			INP_WLOCK_ASSERT(inp);
856 
857 			pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
858 			INP_HASH_WLOCK(pcbinfo);
859 			error = in6_pcbsetport(laddr, inp, td->td_ucred);
860 			INP_HASH_WUNLOCK(pcbinfo);
861 			if (error != 0) {
862 				/* Undo an address bind that may have occurred. */
863 				inp->in6p_laddr = in6addr_any;
864 				goto release;
865 			}
866 		}
867 		faddr = &sin6->sin6_addr;
868 		fport = sin6->sin6_port; /* allow 0 port */
869 
870 	} else {
871 		if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
872 			error = ENOTCONN;
873 			goto release;
874 		}
875 		laddr = &inp->in6p_laddr;
876 		faddr = &inp->in6p_faddr;
877 		fport = inp->inp_fport;
878 	}
879 
880 	ulen = m->m_pkthdr.len;
881 	plen = sizeof(struct udphdr) + ulen;
882 	hlen = sizeof(struct ip6_hdr);
883 
884 	/*
885 	 * Calculate data length and get a mbuf
886 	 * for UDP and IP6 headers.
887 	 */
888 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
889 	if (m == NULL) {
890 		error = ENOBUFS;
891 		goto release;
892 	}
893 
894 	/*
895 	 * Stuff checksum and output datagram.
896 	 */
897 	cscov = cscov_partial = 0;
898 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
899 	udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
900 	udp6->uh_dport = fport;
901 	if (nxt == IPPROTO_UDPLITE) {
902 		struct udpcb *up;
903 
904 		up = intoudpcb(inp);
905 		cscov = up->u_txcslen;
906 		if (cscov >= plen)
907 			cscov = 0;
908 		udp6->uh_ulen = htons(cscov);
909 		/*
910 		 * For UDP-Lite, checksum coverage length of zero means
911 		 * the entire UDPLite packet is covered by the checksum.
912 		 */
913 		cscov_partial = (cscov == 0) ? 0 : 1;
914 	} else if (plen <= 0xffff)
915 		udp6->uh_ulen = htons((u_short)plen);
916 	else
917 		udp6->uh_ulen = 0;
918 	udp6->uh_sum = 0;
919 
920 	ip6 = mtod(m, struct ip6_hdr *);
921 	ip6->ip6_flow	= inp->inp_flow & IPV6_FLOWINFO_MASK;
922 	ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
923 	ip6->ip6_vfc	|= IPV6_VERSION;
924 	ip6->ip6_plen	= htons((u_short)plen);
925 	ip6->ip6_nxt	= nxt;
926 	ip6->ip6_hlim	= in6_selecthlim(inp, NULL);
927 	ip6->ip6_src	= *laddr;
928 	ip6->ip6_dst	= *faddr;
929 
930 #ifdef MAC
931 	mac_inpcb_create_mbuf(inp, m);
932 #endif
933 
934 	if (cscov_partial) {
935 		if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
936 		    sizeof(struct ip6_hdr), plen, cscov)) == 0)
937 			udp6->uh_sum = 0xffff;
938 	} else {
939 		udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
940 		m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
941 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
942 	}
943 
944 	flags = 0;
945 #ifdef	RSS
946 	{
947 		uint32_t hash_val, hash_type;
948 		uint8_t pr;
949 
950 		pr = inp->inp_socket->so_proto->pr_protocol;
951 		/*
952 		 * Calculate an appropriate RSS hash for UDP and
953 		 * UDP Lite.
954 		 *
955 		 * The called function will take care of figuring out
956 		 * whether a 2-tuple or 4-tuple hash is required based
957 		 * on the currently configured scheme.
958 		 *
959 		 * Later later on connected socket values should be
960 		 * cached in the inpcb and reused, rather than constantly
961 		 * re-calculating it.
962 		 *
963 		 * UDP Lite is a different protocol number and will
964 		 * likely end up being hashed as a 2-tuple until
965 		 * RSS / NICs grow UDP Lite protocol awareness.
966 		 */
967 		if (rss_proto_software_hash_v6(faddr, laddr, fport,
968 		    inp->inp_lport, pr, &hash_val, &hash_type) == 0) {
969 			m->m_pkthdr.flowid = hash_val;
970 			M_HASHTYPE_SET(m, hash_type);
971 		}
972 
973 		/*
974 		 * Don't override with the inp cached flowid.
975 		 *
976 		 * Until the whole UDP path is vetted, it may actually
977 		 * be incorrect.
978 		 */
979 		flags |= IP_NODEFAULTFLOWID;
980 	}
981 #endif
982 
983 	UDPSTAT_INC(udps_opackets);
984 	if (nxt == IPPROTO_UDPLITE)
985 		UDPLITE_PROBE(send, NULL, inp, ip6, inp, udp6);
986 	else
987 		UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
988 	error = ip6_output(m, optp,
989 	    INP_WLOCKED(inp) ? &inp->inp_route6 : NULL, flags,
990 	    inp->in6p_moptions, NULL, inp);
991 	INP_UNLOCK(inp);
992 	NET_EPOCH_EXIT(et);
993 
994 	if (control) {
995 		ip6_clearpktopts(&opt, -1);
996 		m_freem(control);
997 	}
998 	return (error);
999 
1000 release:
1001 	INP_UNLOCK(inp);
1002 	NET_EPOCH_EXIT(et);
1003 	if (control) {
1004 		ip6_clearpktopts(&opt, -1);
1005 		m_freem(control);
1006 	}
1007 	m_freem(m);
1008 
1009 	return (error);
1010 }
1011 
1012 static void
1013 udp6_abort(struct socket *so)
1014 {
1015 	struct inpcb *inp;
1016 	struct inpcbinfo *pcbinfo;
1017 
1018 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1019 	inp = sotoinpcb(so);
1020 	KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
1021 
1022 	INP_WLOCK(inp);
1023 #ifdef INET
1024 	if (inp->inp_vflag & INP_IPV4) {
1025 		struct pr_usrreqs *pru;
1026 		uint8_t nxt;
1027 
1028 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1029 		    IPPROTO_UDP : IPPROTO_UDPLITE;
1030 		INP_WUNLOCK(inp);
1031 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1032 		(*pru->pru_abort)(so);
1033 		return;
1034 	}
1035 #endif
1036 
1037 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1038 		INP_HASH_WLOCK(pcbinfo);
1039 		in6_pcbdisconnect(inp);
1040 		inp->in6p_laddr = in6addr_any;
1041 		INP_HASH_WUNLOCK(pcbinfo);
1042 		soisdisconnected(so);
1043 	}
1044 	INP_WUNLOCK(inp);
1045 }
1046 
1047 static int
1048 udp6_attach(struct socket *so, int proto, struct thread *td)
1049 {
1050 	struct inpcb *inp;
1051 	struct inpcbinfo *pcbinfo;
1052 	int error;
1053 
1054 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1055 	inp = sotoinpcb(so);
1056 	KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
1057 
1058 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1059 		error = soreserve(so, udp_sendspace, udp_recvspace);
1060 		if (error)
1061 			return (error);
1062 	}
1063 	INP_INFO_WLOCK(pcbinfo);
1064 	error = in_pcballoc(so, pcbinfo);
1065 	if (error) {
1066 		INP_INFO_WUNLOCK(pcbinfo);
1067 		return (error);
1068 	}
1069 	inp = (struct inpcb *)so->so_pcb;
1070 	inp->inp_vflag |= INP_IPV6;
1071 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
1072 		inp->inp_vflag |= INP_IPV4;
1073 	inp->in6p_hops = -1;	/* use kernel default */
1074 	inp->in6p_cksum = -1;	/* just to be sure */
1075 	/*
1076 	 * XXX: ugly!!
1077 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
1078 	 * because the socket may be bound to an IPv6 wildcard address,
1079 	 * which may match an IPv4-mapped IPv6 address.
1080 	 */
1081 	inp->inp_ip_ttl = V_ip_defttl;
1082 
1083 	error = udp_newudpcb(inp);
1084 	if (error) {
1085 		in_pcbdetach(inp);
1086 		in_pcbfree(inp);
1087 		INP_INFO_WUNLOCK(pcbinfo);
1088 		return (error);
1089 	}
1090 	INP_WUNLOCK(inp);
1091 	INP_INFO_WUNLOCK(pcbinfo);
1092 	return (0);
1093 }
1094 
1095 static int
1096 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1097 {
1098 	struct inpcb *inp;
1099 	struct inpcbinfo *pcbinfo;
1100 	int error;
1101 	u_char vflagsav;
1102 
1103 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1104 	inp = sotoinpcb(so);
1105 	KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
1106 
1107 	INP_WLOCK(inp);
1108 	INP_HASH_WLOCK(pcbinfo);
1109 	vflagsav = inp->inp_vflag;
1110 	inp->inp_vflag &= ~INP_IPV4;
1111 	inp->inp_vflag |= INP_IPV6;
1112 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1113 		struct sockaddr_in6 *sin6_p;
1114 
1115 		sin6_p = (struct sockaddr_in6 *)nam;
1116 
1117 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
1118 			inp->inp_vflag |= INP_IPV4;
1119 #ifdef INET
1120 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
1121 			struct sockaddr_in sin;
1122 
1123 			in6_sin6_2_sin(&sin, sin6_p);
1124 			inp->inp_vflag |= INP_IPV4;
1125 			inp->inp_vflag &= ~INP_IPV6;
1126 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
1127 			    td->td_ucred);
1128 			goto out;
1129 		}
1130 #endif
1131 	}
1132 
1133 	error = in6_pcbbind(inp, nam, td->td_ucred);
1134 #ifdef INET
1135 out:
1136 #endif
1137 	if (error != 0)
1138 		inp->inp_vflag = vflagsav;
1139 	INP_HASH_WUNLOCK(pcbinfo);
1140 	INP_WUNLOCK(inp);
1141 	return (error);
1142 }
1143 
1144 static void
1145 udp6_close(struct socket *so)
1146 {
1147 	struct inpcb *inp;
1148 	struct inpcbinfo *pcbinfo;
1149 
1150 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1151 	inp = sotoinpcb(so);
1152 	KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
1153 
1154 	INP_WLOCK(inp);
1155 #ifdef INET
1156 	if (inp->inp_vflag & INP_IPV4) {
1157 		struct pr_usrreqs *pru;
1158 		uint8_t nxt;
1159 
1160 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1161 		    IPPROTO_UDP : IPPROTO_UDPLITE;
1162 		INP_WUNLOCK(inp);
1163 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1164 		(*pru->pru_disconnect)(so);
1165 		return;
1166 	}
1167 #endif
1168 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1169 		INP_HASH_WLOCK(pcbinfo);
1170 		in6_pcbdisconnect(inp);
1171 		inp->in6p_laddr = in6addr_any;
1172 		INP_HASH_WUNLOCK(pcbinfo);
1173 		soisdisconnected(so);
1174 	}
1175 	INP_WUNLOCK(inp);
1176 }
1177 
1178 static int
1179 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1180 {
1181 	struct inpcb *inp;
1182 	struct inpcbinfo *pcbinfo;
1183 	struct sockaddr_in6 *sin6;
1184 	int error;
1185 	u_char vflagsav;
1186 
1187 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1188 	inp = sotoinpcb(so);
1189 	sin6 = (struct sockaddr_in6 *)nam;
1190 	KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1191 
1192 	/*
1193 	 * XXXRW: Need to clarify locking of v4/v6 flags.
1194 	 */
1195 	INP_WLOCK(inp);
1196 #ifdef INET
1197 	if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1198 		struct sockaddr_in sin;
1199 
1200 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1201 			error = EINVAL;
1202 			goto out;
1203 		}
1204 		if ((inp->inp_vflag & INP_IPV4) == 0) {
1205 			error = EAFNOSUPPORT;
1206 			goto out;
1207 		}
1208 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1209 			error = EISCONN;
1210 			goto out;
1211 		}
1212 		in6_sin6_2_sin(&sin, sin6);
1213 		error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1214 		if (error != 0)
1215 			goto out;
1216 		vflagsav = inp->inp_vflag;
1217 		inp->inp_vflag |= INP_IPV4;
1218 		inp->inp_vflag &= ~INP_IPV6;
1219 		INP_HASH_WLOCK(pcbinfo);
1220 		error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1221 		    td->td_ucred);
1222 		INP_HASH_WUNLOCK(pcbinfo);
1223 		/*
1224 		 * If connect succeeds, mark socket as connected. If
1225 		 * connect fails and socket is unbound, reset inp_vflag
1226 		 * field.
1227 		 */
1228 		if (error == 0)
1229 			soisconnected(so);
1230 		else if (inp->inp_laddr.s_addr == INADDR_ANY &&
1231 		    inp->inp_lport == 0)
1232 			inp->inp_vflag = vflagsav;
1233 		goto out;
1234 	} else {
1235 		if ((inp->inp_vflag & INP_IPV6) == 0) {
1236 			error = EAFNOSUPPORT;
1237 			goto out;
1238 		}
1239 	}
1240 #endif
1241 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1242 		error = EISCONN;
1243 		goto out;
1244 	}
1245 	error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1246 	if (error != 0)
1247 		goto out;
1248 	vflagsav = inp->inp_vflag;
1249 	inp->inp_vflag &= ~INP_IPV4;
1250 	inp->inp_vflag |= INP_IPV6;
1251 	INP_HASH_WLOCK(pcbinfo);
1252 	error = in6_pcbconnect(inp, nam, td->td_ucred);
1253 	INP_HASH_WUNLOCK(pcbinfo);
1254 	/*
1255 	 * If connect succeeds, mark socket as connected. If
1256 	 * connect fails and socket is unbound, reset inp_vflag
1257 	 * field.
1258 	 */
1259 	if (error == 0)
1260 		soisconnected(so);
1261 	else if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
1262 	    inp->inp_lport == 0)
1263 		inp->inp_vflag = vflagsav;
1264 out:
1265 	INP_WUNLOCK(inp);
1266 	return (error);
1267 }
1268 
1269 static void
1270 udp6_detach(struct socket *so)
1271 {
1272 	struct inpcb *inp;
1273 	struct inpcbinfo *pcbinfo;
1274 	struct udpcb *up;
1275 
1276 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1277 	inp = sotoinpcb(so);
1278 	KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1279 
1280 	INP_INFO_WLOCK(pcbinfo);
1281 	INP_WLOCK(inp);
1282 	up = intoudpcb(inp);
1283 	KASSERT(up != NULL, ("%s: up == NULL", __func__));
1284 	in_pcbdetach(inp);
1285 	in_pcbfree(inp);
1286 	INP_INFO_WUNLOCK(pcbinfo);
1287 	udp_discardcb(up);
1288 }
1289 
1290 static int
1291 udp6_disconnect(struct socket *so)
1292 {
1293 	struct inpcb *inp;
1294 	struct inpcbinfo *pcbinfo;
1295 
1296 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1297 	inp = sotoinpcb(so);
1298 	KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1299 
1300 	INP_WLOCK(inp);
1301 #ifdef INET
1302 	if (inp->inp_vflag & INP_IPV4) {
1303 		struct pr_usrreqs *pru;
1304 		uint8_t nxt;
1305 
1306 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1307 		    IPPROTO_UDP : IPPROTO_UDPLITE;
1308 		INP_WUNLOCK(inp);
1309 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1310 		(void)(*pru->pru_disconnect)(so);
1311 		return (0);
1312 	}
1313 #endif
1314 
1315 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1316 		INP_WUNLOCK(inp);
1317 		return (ENOTCONN);
1318 	}
1319 
1320 	INP_HASH_WLOCK(pcbinfo);
1321 	in6_pcbdisconnect(inp);
1322 	inp->in6p_laddr = in6addr_any;
1323 	INP_HASH_WUNLOCK(pcbinfo);
1324 	SOCK_LOCK(so);
1325 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1326 	SOCK_UNLOCK(so);
1327 	INP_WUNLOCK(inp);
1328 	return (0);
1329 }
1330 
1331 static int
1332 udp6_send(struct socket *so, int flags, struct mbuf *m,
1333     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1334 {
1335 	int error;
1336 
1337 	if (addr) {
1338 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1339 			error = EINVAL;
1340 			goto bad;
1341 		}
1342 		if (addr->sa_family != AF_INET6) {
1343 			error = EAFNOSUPPORT;
1344 			goto bad;
1345 		}
1346 	}
1347 
1348 	return (udp6_output(so, flags, m, addr, control, td));
1349 
1350 bad:
1351 	if (control)
1352 		m_freem(control);
1353 	m_freem(m);
1354 	return (error);
1355 }
1356 
1357 struct pr_usrreqs udp6_usrreqs = {
1358 	.pru_abort =		udp6_abort,
1359 	.pru_attach =		udp6_attach,
1360 	.pru_bind =		udp6_bind,
1361 	.pru_connect =		udp6_connect,
1362 	.pru_control =		in6_control,
1363 	.pru_detach =		udp6_detach,
1364 	.pru_disconnect =	udp6_disconnect,
1365 	.pru_peeraddr =		in6_mapped_peeraddr,
1366 	.pru_send =		udp6_send,
1367 	.pru_shutdown =		udp_shutdown,
1368 	.pru_sockaddr =		in6_mapped_sockaddr,
1369 	.pru_soreceive =	soreceive_dgram,
1370 	.pru_sosend =		sosend_dgram,
1371 	.pru_sosetlabel =	in_pcbsosetlabel,
1372 	.pru_close =		udp6_close
1373 };
1374