xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision 7963e4115453c0aa003023386cbbc635de242150)
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 #include "opt_inet.h"
74 #include "opt_inet6.h"
75 #include "opt_ipsec.h"
76 #include "opt_route.h"
77 #include "opt_rss.h"
78 
79 #include <sys/param.h>
80 #include <sys/jail.h>
81 #include <sys/kernel.h>
82 #include <sys/lock.h>
83 #include <sys/mbuf.h>
84 #include <sys/priv.h>
85 #include <sys/proc.h>
86 #include <sys/protosw.h>
87 #include <sys/sdt.h>
88 #include <sys/signalvar.h>
89 #include <sys/socket.h>
90 #include <sys/socketvar.h>
91 #include <sys/sx.h>
92 #include <sys/sysctl.h>
93 #include <sys/syslog.h>
94 #include <sys/systm.h>
95 
96 #include <net/if.h>
97 #include <net/if_var.h>
98 #include <net/if_types.h>
99 #include <net/route.h>
100 #include <net/rss_config.h>
101 
102 #include <netinet/in.h>
103 #include <netinet/in_kdtrace.h>
104 #include <netinet/in_pcb.h>
105 #include <netinet/in_systm.h>
106 #include <netinet/in_var.h>
107 #include <netinet/ip.h>
108 #include <netinet/ip6.h>
109 #include <netinet/icmp6.h>
110 #include <netinet/ip_var.h>
111 #include <netinet/udp.h>
112 #include <netinet/udp_var.h>
113 #include <netinet/udplite.h>
114 
115 #include <netinet6/ip6_var.h>
116 #include <netinet6/in6_fib.h>
117 #include <netinet6/in6_pcb.h>
118 #include <netinet6/in6_rss.h>
119 #include <netinet6/udp6_var.h>
120 #include <netinet6/scope6_var.h>
121 
122 #include <netipsec/ipsec_support.h>
123 
124 #include <security/mac/mac_framework.h>
125 
126 VNET_DEFINE(int, zero_checksum_port) = 0;
127 #define	V_zero_checksum_port	VNET(zero_checksum_port)
128 SYSCTL_INT(_net_inet6_udp6, OID_AUTO, rfc6935_port, CTLFLAG_VNET | CTLFLAG_RW,
129     &VNET_NAME(zero_checksum_port), 0,
130     "Zero UDP checksum allowed for traffic to/from this port.");
131 
132 /*
133  * UDP protocol implementation.
134  * Per RFC 768, August, 1980.
135  */
136 
137 static void		udp6_detach(struct socket *so);
138 
139 static int
140 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
141     struct sockaddr_in6 *fromsa)
142 {
143 	struct socket *so;
144 	struct mbuf *opts = NULL, *tmp_opts;
145 	struct udpcb *up;
146 	bool filtered;
147 
148 	INP_LOCK_ASSERT(inp);
149 
150 	/*
151 	 * Engage the tunneling protocol.
152 	 */
153 	up = intoudpcb(inp);
154 	if (up->u_tun_func != NULL) {
155 		in_pcbref(inp);
156 		INP_RUNLOCK(inp);
157 		filtered = (*up->u_tun_func)(n, off, inp,
158 		    (struct sockaddr *)&fromsa[0], up->u_tun_ctx);
159 		INP_RLOCK(inp);
160 		if (filtered)
161 			return (in_pcbrele_rlocked(inp));
162 	}
163 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
164 	/* Check AH/ESP integrity. */
165 	if (IPSEC_ENABLED(ipv6)) {
166 		if (IPSEC_CHECK_POLICY(ipv6, n, inp) != 0) {
167 			m_freem(n);
168 			return (0);
169 		}
170 	}
171 #endif /* IPSEC */
172 #ifdef MAC
173 	if (mac_inpcb_check_deliver(inp, n) != 0) {
174 		m_freem(n);
175 		return (0);
176 	}
177 #endif
178 	opts = NULL;
179 	if (inp->inp_flags & INP_CONTROLOPTS ||
180 	    inp->inp_socket->so_options & SO_TIMESTAMP)
181 		ip6_savecontrol(inp, n, &opts);
182 	if ((inp->inp_vflag & INP_IPV6) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
183 		tmp_opts = sbcreatecontrol(&fromsa[1],
184 		    sizeof(struct sockaddr_in6), IPV6_ORIGDSTADDR,
185 		    IPPROTO_IPV6, M_NOWAIT);
186                 if (tmp_opts) {
187                         if (opts) {
188                                 tmp_opts->m_next = opts;
189                                 opts = tmp_opts;
190                         } else
191                                 opts = tmp_opts;
192                 }
193 	}
194 	m_adj(n, off + sizeof(struct udphdr));
195 
196 	so = inp->inp_socket;
197 	SOCKBUF_LOCK(&so->so_rcv);
198 	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&fromsa[0], n,
199 	    opts) == 0) {
200 		soroverflow_locked(so);
201 		m_freem(n);
202 		if (opts)
203 			m_freem(opts);
204 		UDPSTAT_INC(udps_fullsock);
205 	} else
206 		sorwakeup_locked(so);
207 	return (0);
208 }
209 
210 struct udp6_multi_match_ctx {
211 	struct ip6_hdr *ip6;
212 	struct udphdr *uh;
213 };
214 
215 static bool
216 udp6_multi_match(const struct inpcb *inp, void *v)
217 {
218 	struct udp6_multi_match_ctx *ctx = v;
219 
220 	if ((inp->inp_vflag & INP_IPV6) == 0)
221 		return(false);
222 	if (inp->inp_lport != ctx->uh->uh_dport)
223 		return(false);
224 	if (inp->inp_fport != 0 && inp->inp_fport != ctx->uh->uh_sport)
225 		return(false);
226 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
227 	    !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ctx->ip6->ip6_dst))
228 		return (false);
229 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
230 	    (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ctx->ip6->ip6_src) ||
231 	    inp->inp_fport != ctx->uh->uh_sport))
232 		return (false);
233 
234 	return (true);
235 }
236 
237 static int
238 udp6_multi_input(struct mbuf *m, int off, int proto,
239     struct sockaddr_in6 *fromsa)
240 {
241 	struct udp6_multi_match_ctx ctx;
242 	struct inpcb_iterator inpi = INP_ITERATOR(udp_get_inpcbinfo(proto),
243 	    INPLOOKUP_RLOCKPCB, udp6_multi_match, &ctx);
244 	struct inpcb *inp;
245 	struct ip6_moptions *imo;
246 	struct mbuf *n;
247 	int appends = 0;
248 
249 	/*
250 	 * In the event that laddr should be set to the link-local
251 	 * address (this happens in RIPng), the multicast address
252 	 * specified in the received packet will not match laddr.  To
253 	 * handle this situation, matching is relaxed if the
254 	 * receiving interface is the same as one specified in the
255 	 * socket and if the destination multicast address matches
256 	 * one of the multicast groups specified in the socket.
257 	 */
258 
259 	/*
260 	 * KAME note: traditionally we dropped udpiphdr from mbuf
261 	 * here.  We need udphdr for IPsec processing so we do that
262 	 * later.
263 	 */
264 	ctx.ip6 = mtod(m, struct ip6_hdr *);
265 	ctx.uh = (struct udphdr *)((char *)ctx.ip6 + off);
266 	while ((inp = inp_next(&inpi)) != NULL) {
267 		INP_RLOCK_ASSERT(inp);
268 		/*
269 		 * XXXRW: Because we weren't holding either the inpcb
270 		 * or the hash lock when we checked for a match
271 		 * before, we should probably recheck now that the
272 		 * inpcb lock is (supposed to be) held.
273 		 */
274 		/*
275 		 * Handle socket delivery policy for any-source
276 		 * and source-specific multicast. [RFC3678]
277 		 */
278 		if ((imo = inp->in6p_moptions) != NULL) {
279 			struct sockaddr_in6	 mcaddr;
280 			int			 blocked;
281 
282 			bzero(&mcaddr, sizeof(struct sockaddr_in6));
283 			mcaddr.sin6_len = sizeof(struct sockaddr_in6);
284 			mcaddr.sin6_family = AF_INET6;
285 			mcaddr.sin6_addr = ctx.ip6->ip6_dst;
286 
287 			blocked = im6o_mc_filter(imo, m->m_pkthdr.rcvif,
288 				(struct sockaddr *)&mcaddr,
289 				(struct sockaddr *)&fromsa[0]);
290 			if (blocked != MCAST_PASS) {
291 				if (blocked == MCAST_NOTGMEMBER)
292 					IP6STAT_INC(ip6s_notmember);
293 				if (blocked == MCAST_NOTSMEMBER ||
294 				    blocked == MCAST_MUTED)
295 					UDPSTAT_INC(udps_filtermcast);
296 				continue;
297 			}
298 		}
299 		if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
300 			if (proto == IPPROTO_UDPLITE)
301 				UDPLITE_PROBE(receive, NULL, inp, ctx.ip6,
302 				    inp, ctx.uh);
303 			else
304 				UDP_PROBE(receive, NULL, inp, ctx.ip6, inp,
305 				    ctx.uh);
306 			if (udp6_append(inp, n, off, fromsa)) {
307 				break;
308 			} else
309 				appends++;
310 		}
311 		/*
312 		 * Don't look for additional matches if this one does
313 		 * not have either the SO_REUSEPORT or SO_REUSEADDR
314 		 * socket options set.  This heuristic avoids
315 		 * searching through all pcbs in the common case of a
316 		 * non-shared port.  It assumes that an application
317 		 * will never clear these options after setting them.
318 		 */
319 		if ((inp->inp_socket->so_options &
320 		     (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0) {
321 			INP_RUNLOCK(inp);
322 			break;
323 		}
324 	}
325 	m_freem(m);
326 
327 	if (appends == 0) {
328 		/*
329 		 * No matching pcb found; discard datagram.  (No need
330 		 * to send an ICMP Port Unreachable for a broadcast
331 		 * or multicast datgram.)
332 		 */
333 		UDPSTAT_INC(udps_noport);
334 		UDPSTAT_INC(udps_noportmcast);
335 	}
336 
337 	return (IPPROTO_DONE);
338 }
339 
340 int
341 udp6_input(struct mbuf **mp, int *offp, int proto)
342 {
343 	struct mbuf *m = *mp;
344 	struct ip6_hdr *ip6;
345 	struct udphdr *uh;
346 	struct inpcb *inp;
347 	struct inpcbinfo *pcbinfo;
348 	struct udpcb *up;
349 	int off = *offp;
350 	int cscov_partial;
351 	int plen, ulen;
352 	struct sockaddr_in6 fromsa[2];
353 	struct m_tag *fwd_tag;
354 	uint16_t uh_sum;
355 	uint8_t nxt;
356 
357 	NET_EPOCH_ASSERT();
358 
359 	if (m->m_len < off + sizeof(struct udphdr)) {
360 		m = m_pullup(m, off + sizeof(struct udphdr));
361 		if (m == NULL) {
362 			IP6STAT_INC(ip6s_exthdrtoolong);
363 			*mp = NULL;
364 			return (IPPROTO_DONE);
365 		}
366 	}
367 	ip6 = mtod(m, struct ip6_hdr *);
368 	uh = (struct udphdr *)((caddr_t)ip6 + off);
369 
370 	UDPSTAT_INC(udps_ipackets);
371 
372 	/*
373 	 * Destination port of 0 is illegal, based on RFC768.
374 	 */
375 	if (uh->uh_dport == 0)
376 		goto badunlocked;
377 
378 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
379 	ulen = ntohs((u_short)uh->uh_ulen);
380 
381 	nxt = proto;
382 	cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
383 	if (nxt == IPPROTO_UDPLITE) {
384 		/* Zero means checksum over the complete packet. */
385 		if (ulen == 0)
386 			ulen = plen;
387 		if (ulen == plen)
388 			cscov_partial = 0;
389 		if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
390 			/* XXX: What is the right UDPLite MIB counter? */
391 			goto badunlocked;
392 		}
393 		if (uh->uh_sum == 0) {
394 			/* XXX: What is the right UDPLite MIB counter? */
395 			goto badunlocked;
396 		}
397 	} else {
398 		if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
399 			UDPSTAT_INC(udps_badlen);
400 			goto badunlocked;
401 		}
402 		if (uh->uh_sum == 0) {
403 			UDPSTAT_INC(udps_nosum);
404 			/*
405 			 * dport 0 was rejected earlier so this is OK even if
406 			 * zero_checksum_port is 0 (which is its default value).
407 			 */
408 			if (ntohs(uh->uh_dport) == V_zero_checksum_port)
409 				goto skip_checksum;
410 			else
411 				goto badunlocked;
412 		}
413 	}
414 
415 	if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
416 	    !cscov_partial) {
417 		if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
418 			uh_sum = m->m_pkthdr.csum_data;
419 		else
420 			uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
421 			    m->m_pkthdr.csum_data);
422 		uh_sum ^= 0xffff;
423 	} else
424 		uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
425 
426 	if (uh_sum != 0) {
427 		UDPSTAT_INC(udps_badsum);
428 		goto badunlocked;
429 	}
430 
431 skip_checksum:
432 	/*
433 	 * Construct sockaddr format source address.
434 	 */
435 	init_sin6(&fromsa[0], m, 0);
436 	fromsa[0].sin6_port = uh->uh_sport;
437 	init_sin6(&fromsa[1], m, 1);
438 	fromsa[1].sin6_port = uh->uh_dport;
439 
440 	pcbinfo = udp_get_inpcbinfo(nxt);
441 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))  {
442 		*mp = NULL;
443 		return (udp6_multi_input(m, off, proto, fromsa));
444 	}
445 
446 	/*
447 	 * Locate pcb for datagram.
448 	 */
449 
450 	/*
451 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
452 	 */
453 	if ((m->m_flags & M_IP6_NEXTHOP) &&
454 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
455 		struct sockaddr_in6 *next_hop6;
456 
457 		next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
458 
459 		/*
460 		 * Transparently forwarded. Pretend to be the destination.
461 		 * Already got one like this?
462 		 */
463 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
464 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
465 		    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
466 		if (!inp) {
467 			/*
468 			 * It's new.  Try to find the ambushing socket.
469 			 * Because we've rewritten the destination address,
470 			 * any hardware-generated hash is ignored.
471 			 */
472 			inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
473 			    uh->uh_sport, &next_hop6->sin6_addr,
474 			    next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
475 			    uh->uh_dport, INPLOOKUP_WILDCARD |
476 			    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
477 		}
478 		/* Remove the tag from the packet. We don't need it anymore. */
479 		m_tag_delete(m, fwd_tag);
480 		m->m_flags &= ~M_IP6_NEXTHOP;
481 	} else
482 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
483 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
484 		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
485 		    m->m_pkthdr.rcvif, m);
486 	if (inp == NULL) {
487 		if (V_udp_log_in_vain) {
488 			char ip6bufs[INET6_ADDRSTRLEN];
489 			char ip6bufd[INET6_ADDRSTRLEN];
490 
491 			log(LOG_INFO,
492 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
493 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
494 			    ntohs(uh->uh_dport),
495 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
496 			    ntohs(uh->uh_sport));
497 		}
498 		if (nxt == IPPROTO_UDPLITE)
499 			UDPLITE_PROBE(receive, NULL, NULL, ip6, NULL, uh);
500 		else
501 			UDP_PROBE(receive, NULL, NULL, ip6, NULL, uh);
502 		UDPSTAT_INC(udps_noport);
503 		if (m->m_flags & M_MCAST) {
504 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
505 			UDPSTAT_INC(udps_noportmcast);
506 			goto badunlocked;
507 		}
508 		if (V_udp_blackhole && (V_udp_blackhole_local ||
509 		    !in6_localaddr(&ip6->ip6_src)))
510 			goto badunlocked;
511 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
512 		*mp = NULL;
513 		return (IPPROTO_DONE);
514 	}
515 	INP_RLOCK_ASSERT(inp);
516 	up = intoudpcb(inp);
517 	if (cscov_partial) {
518 		if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
519 			INP_RUNLOCK(inp);
520 			m_freem(m);
521 			*mp = NULL;
522 			return (IPPROTO_DONE);
523 		}
524 	}
525 	if (nxt == IPPROTO_UDPLITE)
526 		UDPLITE_PROBE(receive, NULL, inp, ip6, inp, uh);
527 	else
528 		UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
529 	if (udp6_append(inp, m, off, fromsa) == 0)
530 		INP_RUNLOCK(inp);
531 	*mp = NULL;
532 	return (IPPROTO_DONE);
533 
534 badunlocked:
535 	m_freem(m);
536 	*mp = NULL;
537 	return (IPPROTO_DONE);
538 }
539 
540 static void
541 udp6_common_ctlinput(struct ip6ctlparam *ip6cp, struct inpcbinfo *pcbinfo)
542 {
543 	struct udphdr uh;
544 	struct ip6_hdr *ip6;
545 	struct mbuf *m;
546 	struct inpcb *inp;
547 	int errno, off = 0;
548 	struct udp_portonly {
549 		u_int16_t uh_sport;
550 		u_int16_t uh_dport;
551 	} *uhp;
552 
553 	if ((errno = icmp6_errmap(ip6cp->ip6c_icmp6)) == 0)
554 		return;
555 
556 	m = ip6cp->ip6c_m;
557 	ip6 = ip6cp->ip6c_ip6;
558 	off = ip6cp->ip6c_off;
559 
560 	/* Check if we can safely examine src and dst ports. */
561 	if (m->m_pkthdr.len < off + sizeof(*uhp))
562 		return;
563 
564 	bzero(&uh, sizeof(uh));
565 	m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
566 
567 	/* Check to see if its tunneled */
568 	inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_dst, uh.uh_dport,
569 	    &ip6->ip6_src, uh.uh_sport, INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
570 	    m->m_pkthdr.rcvif, m);
571 	if (inp != NULL) {
572 		struct udpcb *up;
573 		udp_tun_icmp_t *func;
574 
575 		up = intoudpcb(inp);
576 		func = up->u_icmp_func;
577 		INP_RUNLOCK(inp);
578 		if (func != NULL)
579 			func(ip6cp);
580 	}
581 	in6_pcbnotify(pcbinfo, ip6cp->ip6c_finaldst, uh.uh_dport,
582 	    ip6cp->ip6c_src, uh.uh_sport, errno, ip6cp->ip6c_cmdarg,
583 	    udp_notify);
584 }
585 
586 static void
587 udp6_ctlinput(struct ip6ctlparam *ctl)
588 {
589 
590 	return (udp6_common_ctlinput(ctl, &V_udbinfo));
591 }
592 
593 static void
594 udplite6_ctlinput(struct ip6ctlparam *ctl)
595 {
596 
597 	return (udp6_common_ctlinput(ctl, &V_ulitecbinfo));
598 }
599 
600 static int
601 udp6_getcred(SYSCTL_HANDLER_ARGS)
602 {
603 	struct xucred xuc;
604 	struct sockaddr_in6 addrs[2];
605 	struct epoch_tracker et;
606 	struct inpcb *inp;
607 	int error;
608 
609 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
610 	if (error)
611 		return (error);
612 
613 	if (req->newlen != sizeof(addrs))
614 		return (EINVAL);
615 	if (req->oldlen != sizeof(struct xucred))
616 		return (EINVAL);
617 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
618 	if (error)
619 		return (error);
620 	if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
621 	    (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
622 		return (error);
623 	}
624 	NET_EPOCH_ENTER(et);
625 	inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
626 	    addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
627 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
628 	NET_EPOCH_EXIT(et);
629 	if (inp != NULL) {
630 		INP_RLOCK_ASSERT(inp);
631 		if (inp->inp_socket == NULL)
632 			error = ENOENT;
633 		if (error == 0)
634 			error = cr_canseesocket(req->td->td_ucred,
635 			    inp->inp_socket);
636 		if (error == 0)
637 			cru2x(inp->inp_cred, &xuc);
638 		INP_RUNLOCK(inp);
639 	} else
640 		error = ENOENT;
641 	if (error == 0)
642 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
643 	return (error);
644 }
645 
646 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred,
647     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_MPSAFE,
648     0, 0, udp6_getcred, "S,xucred",
649     "Get the xucred of a UDP6 connection");
650 
651 static int
652 udp6_send(struct socket *so, int flags_arg, struct mbuf *m,
653     struct sockaddr *addr6, struct mbuf *control, struct thread *td)
654 {
655 	struct inpcb *inp;
656 	struct ip6_hdr *ip6;
657 	struct udphdr *udp6;
658 	struct in6_addr *laddr, *faddr, in6a;
659 	struct ip6_pktopts *optp, opt;
660 	struct sockaddr_in6 *sin6, tmp;
661 	struct epoch_tracker et;
662 	int cscov_partial, error, flags, hlen, scope_ambiguous;
663 	u_int32_t ulen, plen;
664 	uint16_t cscov;
665 	u_short fport;
666 	uint8_t nxt;
667 
668 	if (addr6) {
669 		error = 0;
670 		if (addr6->sa_family != AF_INET6)
671 			error = EAFNOSUPPORT;
672 		else if (addr6->sa_len != sizeof(struct sockaddr_in6))
673 			error = EINVAL;
674 		if (__predict_false(error != 0)) {
675 			m_freem(control);
676 			m_freem(m);
677 			return (error);
678 		}
679 	}
680 
681 	sin6 = (struct sockaddr_in6 *)addr6;
682 
683 	/*
684 	 * In contrast to IPv4 we do not validate the max. packet length
685 	 * here due to IPv6 Jumbograms (RFC2675).
686 	 */
687 
688 	scope_ambiguous = 0;
689 	if (sin6) {
690 		/* Protect *addr6 from overwrites. */
691 		tmp = *sin6;
692 		sin6 = &tmp;
693 
694 		/*
695 		 * Application should provide a proper zone ID or the use of
696 		 * default zone IDs should be enabled.  Unfortunately, some
697 		 * applications do not behave as it should, so we need a
698 		 * workaround.  Even if an appropriate ID is not determined,
699 		 * we'll see if we can determine the outgoing interface.  If we
700 		 * can, determine the zone ID based on the interface below.
701 		 */
702 		if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
703 			scope_ambiguous = 1;
704 		if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0) {
705 			if (control)
706 				m_freem(control);
707 			m_freem(m);
708 			return (error);
709 		}
710 	}
711 
712 	inp = sotoinpcb(so);
713 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
714 	/*
715 	 * In the following cases we want a write lock on the inp for either
716 	 * local operations or for possible route cache updates in the IPv6
717 	 * output path:
718 	 * - on connected sockets (sin6 is NULL) for route cache updates,
719 	 * - when we are not bound to an address and source port (it is
720 	 *   in6_pcbsetport() which will require the write lock).
721 	 *
722 	 * We check the inp fields before actually locking the inp, so
723 	 * here exists a race, and we may WLOCK the inp and end with already
724 	 * bound one by other thread. This is fine.
725 	 */
726 	if (sin6 == NULL || (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
727 	    inp->inp_lport == 0))
728 		INP_WLOCK(inp);
729 	else
730 		INP_RLOCK(inp);
731 
732 	nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
733 	    IPPROTO_UDP : IPPROTO_UDPLITE;
734 
735 #ifdef INET
736 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
737 		int hasv4addr;
738 
739 		if (sin6 == NULL)
740 			hasv4addr = (inp->inp_vflag & INP_IPV4);
741 		else
742 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
743 			    ? 1 : 0;
744 		if (hasv4addr) {
745 			/*
746 			 * XXXRW: We release UDP-layer locks before calling
747 			 * udp_send() in order to avoid recursion.  However,
748 			 * this does mean there is a short window where inp's
749 			 * fields are unstable.  Could this lead to a
750 			 * potential race in which the factors causing us to
751 			 * select the UDPv4 output routine are invalidated?
752 			 */
753 			INP_UNLOCK(inp);
754 			if (sin6)
755 				in6_sin6_2_sin_in_sock((struct sockaddr *)sin6);
756 			/* addr will just be freed in sendit(). */
757 			return (udp_send(so, flags_arg | PRUS_IPV6, m,
758 			    (struct sockaddr *)sin6, control, td));
759 		}
760 	} else
761 #endif
762 	if (sin6 && IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
763 		/*
764 		 * Given this is either an IPv6-only socket or no INET is
765 		 * supported we will fail the send if the given destination
766 		 * address is a v4mapped address.
767 		 */
768 		INP_UNLOCK(inp);
769 		m_freem(m);
770 		m_freem(control);
771 		return (EINVAL);
772 	}
773 
774 	NET_EPOCH_ENTER(et);
775 	if (control) {
776 		if ((error = ip6_setpktopts(control, &opt,
777 		    inp->in6p_outputopts, td->td_ucred, nxt)) != 0) {
778 			goto release;
779 		}
780 		optp = &opt;
781 	} else
782 		optp = inp->in6p_outputopts;
783 
784 	if (sin6) {
785 		/*
786 		 * Since we saw no essential reason for calling in_pcbconnect,
787 		 * we get rid of such kind of logic, and call in6_selectsrc
788 		 * and in6_pcbsetport in order to fill in the local address
789 		 * and the local port.
790 		 */
791 		if (sin6->sin6_port == 0) {
792 			error = EADDRNOTAVAIL;
793 			goto release;
794 		}
795 
796 		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
797 			/* how about ::ffff:0.0.0.0 case? */
798 			error = EISCONN;
799 			goto release;
800 		}
801 
802 		/*
803 		 * Given we handle the v4mapped case in the INET block above
804 		 * assert here that it must not happen anymore.
805 		 */
806 		KASSERT(!IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr),
807 		    ("%s: sin6(%p)->sin6_addr is v4mapped which we "
808 		    "should have handled.", __func__, sin6));
809 
810 		/* This only requires read-locking. */
811 		error = in6_selectsrc_socket(sin6, optp, inp,
812 		    td->td_ucred, scope_ambiguous, &in6a, NULL);
813 		if (error)
814 			goto release;
815 		laddr = &in6a;
816 
817 		if (inp->inp_lport == 0) {
818 			struct inpcbinfo *pcbinfo;
819 
820 			INP_WLOCK_ASSERT(inp);
821 
822 			pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
823 			INP_HASH_WLOCK(pcbinfo);
824 			error = in6_pcbsetport(laddr, inp, td->td_ucred);
825 			INP_HASH_WUNLOCK(pcbinfo);
826 			if (error != 0) {
827 				/* Undo an address bind that may have occurred. */
828 				inp->in6p_laddr = in6addr_any;
829 				goto release;
830 			}
831 		}
832 		faddr = &sin6->sin6_addr;
833 		fport = sin6->sin6_port; /* allow 0 port */
834 
835 	} else {
836 		if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
837 			error = ENOTCONN;
838 			goto release;
839 		}
840 		laddr = &inp->in6p_laddr;
841 		faddr = &inp->in6p_faddr;
842 		fport = inp->inp_fport;
843 	}
844 
845 	ulen = m->m_pkthdr.len;
846 	plen = sizeof(struct udphdr) + ulen;
847 	hlen = sizeof(struct ip6_hdr);
848 
849 	/*
850 	 * Calculate data length and get a mbuf
851 	 * for UDP and IP6 headers.
852 	 */
853 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
854 	if (m == NULL) {
855 		error = ENOBUFS;
856 		goto release;
857 	}
858 
859 	/*
860 	 * Stuff checksum and output datagram.
861 	 */
862 	cscov = cscov_partial = 0;
863 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
864 	udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
865 	udp6->uh_dport = fport;
866 	if (nxt == IPPROTO_UDPLITE) {
867 		struct udpcb *up;
868 
869 		up = intoudpcb(inp);
870 		cscov = up->u_txcslen;
871 		if (cscov >= plen)
872 			cscov = 0;
873 		udp6->uh_ulen = htons(cscov);
874 		/*
875 		 * For UDP-Lite, checksum coverage length of zero means
876 		 * the entire UDPLite packet is covered by the checksum.
877 		 */
878 		cscov_partial = (cscov == 0) ? 0 : 1;
879 	} else if (plen <= 0xffff)
880 		udp6->uh_ulen = htons((u_short)plen);
881 	else
882 		udp6->uh_ulen = 0;
883 	udp6->uh_sum = 0;
884 
885 	ip6 = mtod(m, struct ip6_hdr *);
886 	ip6->ip6_flow	= inp->inp_flow & IPV6_FLOWINFO_MASK;
887 	ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
888 	ip6->ip6_vfc	|= IPV6_VERSION;
889 	ip6->ip6_plen	= htons((u_short)plen);
890 	ip6->ip6_nxt	= nxt;
891 	ip6->ip6_hlim	= in6_selecthlim(inp, NULL);
892 	ip6->ip6_src	= *laddr;
893 	ip6->ip6_dst	= *faddr;
894 
895 #ifdef MAC
896 	mac_inpcb_create_mbuf(inp, m);
897 #endif
898 
899 	if (cscov_partial) {
900 		if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
901 		    sizeof(struct ip6_hdr), plen, cscov)) == 0)
902 			udp6->uh_sum = 0xffff;
903 	} else {
904 		udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
905 		m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
906 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
907 	}
908 
909 	flags = 0;
910 #if defined(ROUTE_MPATH) || defined(RSS)
911 	if (CALC_FLOWID_OUTBOUND_SENDTO) {
912 		uint32_t hash_type, hash_val;
913 		uint8_t pr;
914 
915 		pr = inp->inp_socket->so_proto->pr_protocol;
916 
917 		hash_val = fib6_calc_packet_hash(laddr, faddr,
918 		    inp->inp_lport, fport, pr, &hash_type);
919 		m->m_pkthdr.flowid = hash_val;
920 		M_HASHTYPE_SET(m, hash_type);
921 	}
922 	/* do not use inp flowid */
923 	flags |= IP_NODEFAULTFLOWID;
924 #endif
925 
926 	UDPSTAT_INC(udps_opackets);
927 	if (nxt == IPPROTO_UDPLITE)
928 		UDPLITE_PROBE(send, NULL, inp, ip6, inp, udp6);
929 	else
930 		UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
931 	error = ip6_output(m, optp,
932 	    INP_WLOCKED(inp) ? &inp->inp_route6 : NULL, flags,
933 	    inp->in6p_moptions, NULL, inp);
934 	INP_UNLOCK(inp);
935 	NET_EPOCH_EXIT(et);
936 
937 	if (control) {
938 		ip6_clearpktopts(&opt, -1);
939 		m_freem(control);
940 	}
941 	return (error);
942 
943 release:
944 	INP_UNLOCK(inp);
945 	NET_EPOCH_EXIT(et);
946 	if (control) {
947 		ip6_clearpktopts(&opt, -1);
948 		m_freem(control);
949 	}
950 	m_freem(m);
951 
952 	return (error);
953 }
954 
955 static void
956 udp6_abort(struct socket *so)
957 {
958 	struct inpcb *inp;
959 	struct inpcbinfo *pcbinfo;
960 
961 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
962 	inp = sotoinpcb(so);
963 	KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
964 
965 	INP_WLOCK(inp);
966 #ifdef INET
967 	if (inp->inp_vflag & INP_IPV4) {
968 		INP_WUNLOCK(inp);
969 		udp_abort(so);
970 		return;
971 	}
972 #endif
973 
974 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
975 		INP_HASH_WLOCK(pcbinfo);
976 		in6_pcbdisconnect(inp);
977 		INP_HASH_WUNLOCK(pcbinfo);
978 		soisdisconnected(so);
979 	}
980 	INP_WUNLOCK(inp);
981 }
982 
983 static int
984 udp6_attach(struct socket *so, int proto, struct thread *td)
985 {
986 	struct inpcbinfo *pcbinfo;
987 	struct inpcb *inp;
988 	struct udpcb *up;
989 	int error;
990 
991 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
992 	inp = sotoinpcb(so);
993 	KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
994 
995 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
996 		error = soreserve(so, udp_sendspace, udp_recvspace);
997 		if (error)
998 			return (error);
999 	}
1000 	error = in_pcballoc(so, pcbinfo);
1001 	if (error)
1002 		return (error);
1003 	inp = (struct inpcb *)so->so_pcb;
1004 	inp->in6p_cksum = -1;	/* just to be sure */
1005 	/*
1006 	 * XXX: ugly!!
1007 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
1008 	 * because the socket may be bound to an IPv6 wildcard address,
1009 	 * which may match an IPv4-mapped IPv6 address.
1010 	 */
1011 	inp->inp_ip_ttl = V_ip_defttl;
1012 	up = intoudpcb(inp);
1013 	bzero(&up->u_start_zero, u_zero_size);
1014 	INP_WUNLOCK(inp);
1015 	return (0);
1016 }
1017 
1018 static int
1019 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1020 {
1021 	struct sockaddr_in6 *sin6_p;
1022 	struct inpcb *inp;
1023 	struct inpcbinfo *pcbinfo;
1024 	int error;
1025 	u_char vflagsav;
1026 
1027 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1028 	inp = sotoinpcb(so);
1029 	KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
1030 
1031 	if (nam->sa_family != AF_INET6)
1032 		return (EAFNOSUPPORT);
1033 	if (nam->sa_len != sizeof(struct sockaddr_in6))
1034 		return (EINVAL);
1035 
1036 	sin6_p = (struct sockaddr_in6 *)nam;
1037 
1038 	INP_WLOCK(inp);
1039 	INP_HASH_WLOCK(pcbinfo);
1040 	vflagsav = inp->inp_vflag;
1041 	inp->inp_vflag &= ~INP_IPV4;
1042 	inp->inp_vflag |= INP_IPV6;
1043 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1044 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
1045 			inp->inp_vflag |= INP_IPV4;
1046 #ifdef INET
1047 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
1048 			struct sockaddr_in sin;
1049 
1050 			in6_sin6_2_sin(&sin, sin6_p);
1051 			inp->inp_vflag |= INP_IPV4;
1052 			inp->inp_vflag &= ~INP_IPV6;
1053 			error = in_pcbbind(inp, &sin, td->td_ucred);
1054 			goto out;
1055 		}
1056 #endif
1057 	}
1058 
1059 	error = in6_pcbbind(inp, sin6_p, td->td_ucred);
1060 #ifdef INET
1061 out:
1062 #endif
1063 	if (error != 0)
1064 		inp->inp_vflag = vflagsav;
1065 	INP_HASH_WUNLOCK(pcbinfo);
1066 	INP_WUNLOCK(inp);
1067 	return (error);
1068 }
1069 
1070 static void
1071 udp6_close(struct socket *so)
1072 {
1073 	struct inpcb *inp;
1074 	struct inpcbinfo *pcbinfo;
1075 
1076 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1077 	inp = sotoinpcb(so);
1078 	KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
1079 
1080 	INP_WLOCK(inp);
1081 #ifdef INET
1082 	if (inp->inp_vflag & INP_IPV4) {
1083 		INP_WUNLOCK(inp);
1084 		(void)udp_disconnect(so);
1085 		return;
1086 	}
1087 #endif
1088 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1089 		INP_HASH_WLOCK(pcbinfo);
1090 		in6_pcbdisconnect(inp);
1091 		INP_HASH_WUNLOCK(pcbinfo);
1092 		soisdisconnected(so);
1093 	}
1094 	INP_WUNLOCK(inp);
1095 }
1096 
1097 static int
1098 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1099 {
1100 	struct epoch_tracker et;
1101 	struct inpcb *inp;
1102 	struct inpcbinfo *pcbinfo;
1103 	struct sockaddr_in6 *sin6;
1104 	int error;
1105 	u_char vflagsav;
1106 
1107 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1108 	inp = sotoinpcb(so);
1109 	KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1110 
1111 	sin6 = (struct sockaddr_in6 *)nam;
1112 	if (sin6->sin6_family != AF_INET6)
1113 		return (EAFNOSUPPORT);
1114 	if (sin6->sin6_len != sizeof(*sin6))
1115 		return (EINVAL);
1116 
1117 	/*
1118 	 * XXXRW: Need to clarify locking of v4/v6 flags.
1119 	 */
1120 	INP_WLOCK(inp);
1121 #ifdef INET
1122 	if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1123 		struct sockaddr_in sin;
1124 
1125 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1126 			error = EINVAL;
1127 			goto out;
1128 		}
1129 		if ((inp->inp_vflag & INP_IPV4) == 0) {
1130 			error = EAFNOSUPPORT;
1131 			goto out;
1132 		}
1133 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1134 			error = EISCONN;
1135 			goto out;
1136 		}
1137 		in6_sin6_2_sin(&sin, sin6);
1138 		error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1139 		if (error != 0)
1140 			goto out;
1141 		vflagsav = inp->inp_vflag;
1142 		inp->inp_vflag |= INP_IPV4;
1143 		inp->inp_vflag &= ~INP_IPV6;
1144 		NET_EPOCH_ENTER(et);
1145 		INP_HASH_WLOCK(pcbinfo);
1146 		error = in_pcbconnect(inp, &sin, td->td_ucred, true);
1147 		INP_HASH_WUNLOCK(pcbinfo);
1148 		NET_EPOCH_EXIT(et);
1149 		/*
1150 		 * If connect succeeds, mark socket as connected. If
1151 		 * connect fails and socket is unbound, reset inp_vflag
1152 		 * field.
1153 		 */
1154 		if (error == 0)
1155 			soisconnected(so);
1156 		else if (inp->inp_laddr.s_addr == INADDR_ANY &&
1157 		    inp->inp_lport == 0)
1158 			inp->inp_vflag = vflagsav;
1159 		goto out;
1160 	} else {
1161 		if ((inp->inp_vflag & INP_IPV6) == 0) {
1162 			error = EAFNOSUPPORT;
1163 			goto out;
1164 		}
1165 	}
1166 #endif
1167 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1168 		error = EISCONN;
1169 		goto out;
1170 	}
1171 	error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1172 	if (error != 0)
1173 		goto out;
1174 	vflagsav = inp->inp_vflag;
1175 	inp->inp_vflag &= ~INP_IPV4;
1176 	inp->inp_vflag |= INP_IPV6;
1177 	NET_EPOCH_ENTER(et);
1178 	INP_HASH_WLOCK(pcbinfo);
1179 	error = in6_pcbconnect(inp, sin6, td->td_ucred, true);
1180 	INP_HASH_WUNLOCK(pcbinfo);
1181 	NET_EPOCH_EXIT(et);
1182 	/*
1183 	 * If connect succeeds, mark socket as connected. If
1184 	 * connect fails and socket is unbound, reset inp_vflag
1185 	 * field.
1186 	 */
1187 	if (error == 0)
1188 		soisconnected(so);
1189 	else if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
1190 	    inp->inp_lport == 0)
1191 		inp->inp_vflag = vflagsav;
1192 out:
1193 	INP_WUNLOCK(inp);
1194 	return (error);
1195 }
1196 
1197 static void
1198 udp6_detach(struct socket *so)
1199 {
1200 	struct inpcb *inp;
1201 
1202 	inp = sotoinpcb(so);
1203 	KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1204 
1205 	INP_WLOCK(inp);
1206 	in_pcbdetach(inp);
1207 	in_pcbfree(inp);
1208 }
1209 
1210 static int
1211 udp6_disconnect(struct socket *so)
1212 {
1213 	struct inpcb *inp;
1214 	struct inpcbinfo *pcbinfo;
1215 
1216 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1217 	inp = sotoinpcb(so);
1218 	KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1219 
1220 	INP_WLOCK(inp);
1221 #ifdef INET
1222 	if (inp->inp_vflag & INP_IPV4) {
1223 		INP_WUNLOCK(inp);
1224 		(void)udp_disconnect(so);
1225 		return (0);
1226 	}
1227 #endif
1228 
1229 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1230 		INP_WUNLOCK(inp);
1231 		return (ENOTCONN);
1232 	}
1233 
1234 	INP_HASH_WLOCK(pcbinfo);
1235 	in6_pcbdisconnect(inp);
1236 	INP_HASH_WUNLOCK(pcbinfo);
1237 	SOCK_LOCK(so);
1238 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1239 	SOCK_UNLOCK(so);
1240 	INP_WUNLOCK(inp);
1241 	return (0);
1242 }
1243 
1244 #define	UDP6_PROTOSW							\
1245 	.pr_type =		SOCK_DGRAM,				\
1246 	.pr_flags =		PR_ATOMIC|PR_ADDR|PR_CAPATTACH,		\
1247 	.pr_ctloutput =		udp_ctloutput,				\
1248 	.pr_abort =		udp6_abort,				\
1249 	.pr_attach =		udp6_attach,				\
1250 	.pr_bind =		udp6_bind,				\
1251 	.pr_connect =		udp6_connect,				\
1252 	.pr_control =		in6_control,				\
1253 	.pr_detach =		udp6_detach,				\
1254 	.pr_disconnect =	udp6_disconnect,			\
1255 	.pr_peeraddr =		in6_mapped_peeraddr,			\
1256 	.pr_send =		udp6_send,				\
1257 	.pr_shutdown =		udp_shutdown,				\
1258 	.pr_sockaddr =		in6_mapped_sockaddr,			\
1259 	.pr_soreceive =		soreceive_dgram,			\
1260 	.pr_sosend =		sosend_dgram,				\
1261 	.pr_sosetlabel =	in_pcbsosetlabel,			\
1262 	.pr_close =		udp6_close
1263 
1264 struct protosw udp6_protosw = {
1265 	.pr_protocol =		IPPROTO_UDP,
1266 	UDP6_PROTOSW
1267 };
1268 
1269 struct protosw udplite6_protosw = {
1270 	.pr_protocol =		IPPROTO_UDPLITE,
1271 	UDP6_PROTOSW
1272 };
1273 
1274 static void
1275 udp6_init(void *arg __unused)
1276 {
1277 
1278 	IP6PROTO_REGISTER(IPPROTO_UDP, udp6_input, udp6_ctlinput);
1279 	IP6PROTO_REGISTER(IPPROTO_UDPLITE, udp6_input, udplite6_ctlinput);
1280 }
1281 SYSINIT(udp6_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, udp6_init, NULL);
1282