xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision 780fb4a2fa9a9aee5ac48a60b790f567c0dc13e9)
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 epoch_tracker et;
218 	struct sockaddr_in6 fromsa[2];
219 	struct m_tag *fwd_tag;
220 	uint16_t uh_sum;
221 	uint8_t nxt;
222 
223 	ifp = m->m_pkthdr.rcvif;
224 
225 #ifndef PULLDOWN_TEST
226 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
227 	ip6 = mtod(m, struct ip6_hdr *);
228 	uh = (struct udphdr *)((caddr_t)ip6 + off);
229 #else
230 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
231 	if (!uh)
232 		return (IPPROTO_DONE);
233 	ip6 = mtod(m, struct ip6_hdr *);
234 #endif
235 
236 	UDPSTAT_INC(udps_ipackets);
237 
238 	/*
239 	 * Destination port of 0 is illegal, based on RFC768.
240 	 */
241 	if (uh->uh_dport == 0)
242 		goto badunlocked;
243 
244 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
245 	ulen = ntohs((u_short)uh->uh_ulen);
246 
247 	nxt = proto;
248 	cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
249 	if (nxt == IPPROTO_UDPLITE) {
250 		/* Zero means checksum over the complete packet. */
251 		if (ulen == 0)
252 			ulen = plen;
253 		if (ulen == plen)
254 			cscov_partial = 0;
255 		if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
256 			/* XXX: What is the right UDPLite MIB counter? */
257 			goto badunlocked;
258 		}
259 		if (uh->uh_sum == 0) {
260 			/* XXX: What is the right UDPLite MIB counter? */
261 			goto badunlocked;
262 		}
263 	} else {
264 		if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
265 			UDPSTAT_INC(udps_badlen);
266 			goto badunlocked;
267 		}
268 		if (uh->uh_sum == 0) {
269 			UDPSTAT_INC(udps_nosum);
270 			goto badunlocked;
271 		}
272 	}
273 
274 	if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
275 	    !cscov_partial) {
276 		if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
277 			uh_sum = m->m_pkthdr.csum_data;
278 		else
279 			uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
280 			    m->m_pkthdr.csum_data);
281 		uh_sum ^= 0xffff;
282 	} else
283 		uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
284 
285 	if (uh_sum != 0) {
286 		UDPSTAT_INC(udps_badsum);
287 		goto badunlocked;
288 	}
289 
290 	/*
291 	 * Construct sockaddr format source address.
292 	 */
293 	init_sin6(&fromsa[0], m, 0);
294 	fromsa[0].sin6_port = uh->uh_sport;
295 	init_sin6(&fromsa[1], m, 1);
296 	fromsa[1].sin6_port = uh->uh_dport;
297 
298 	pcbinfo = udp_get_inpcbinfo(nxt);
299 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
300 		struct inpcb *last;
301 		struct inpcbhead *pcblist;
302 		struct ip6_moptions *imo;
303 
304 		INP_INFO_RLOCK_ET(pcbinfo, et);
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 						UDP_PROBE(receive, NULL, last, ip6,
392 					        last, uh);
393 						if (udp6_append(last, n, off, fromsa))
394 							goto inp_lost;
395 					}
396 					INP_RUNLOCK(last);
397 				}
398 			}
399 			last = inp;
400 			/*
401 			 * Don't look for additional matches if this one does
402 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
403 			 * socket options set.  This heuristic avoids
404 			 * searching through all pcbs in the common case of a
405 			 * non-shared port.  It assumes that an application
406 			 * will never clear these options after setting them.
407 			 */
408 			if ((last->inp_socket->so_options &
409 			     (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0)
410 				break;
411 		}
412 
413 		if (last == NULL) {
414 			/*
415 			 * No matching pcb found; discard datagram.  (No need
416 			 * to send an ICMP Port Unreachable for a broadcast
417 			 * or multicast datgram.)
418 			 */
419 			UDPSTAT_INC(udps_noport);
420 			UDPSTAT_INC(udps_noportmcast);
421 			goto badheadlocked;
422 		}
423 		INP_RLOCK(last);
424 		if (__predict_true(last->inp_flags2 & INP_FREED) == 0) {
425 			UDP_PROBE(receive, NULL, last, ip6, last, uh);
426 			if (udp6_append(last, m, off, fromsa) == 0)
427 				INP_RUNLOCK(last);
428 		} else
429 			INP_RUNLOCK(last);
430 		INP_INFO_RUNLOCK_ET(pcbinfo, et);
431 	inp_lost:
432 		return (IPPROTO_DONE);
433 	}
434 	/*
435 	 * Locate pcb for datagram.
436 	 */
437 
438 	/*
439 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
440 	 */
441 	if ((m->m_flags & M_IP6_NEXTHOP) &&
442 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
443 		struct sockaddr_in6 *next_hop6;
444 
445 		next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
446 
447 		/*
448 		 * Transparently forwarded. Pretend to be the destination.
449 		 * Already got one like this?
450 		 */
451 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
452 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
453 		    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
454 		if (!inp) {
455 			/*
456 			 * It's new.  Try to find the ambushing socket.
457 			 * Because we've rewritten the destination address,
458 			 * any hardware-generated hash is ignored.
459 			 */
460 			inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
461 			    uh->uh_sport, &next_hop6->sin6_addr,
462 			    next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
463 			    uh->uh_dport, INPLOOKUP_WILDCARD |
464 			    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
465 		}
466 		/* Remove the tag from the packet. We don't need it anymore. */
467 		m_tag_delete(m, fwd_tag);
468 		m->m_flags &= ~M_IP6_NEXTHOP;
469 	} else
470 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
471 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
472 		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
473 		    m->m_pkthdr.rcvif, m);
474 	if (inp == NULL) {
475 		if (udp_log_in_vain) {
476 			char ip6bufs[INET6_ADDRSTRLEN];
477 			char ip6bufd[INET6_ADDRSTRLEN];
478 
479 			log(LOG_INFO,
480 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
481 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
482 			    ntohs(uh->uh_dport),
483 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
484 			    ntohs(uh->uh_sport));
485 		}
486 		UDPSTAT_INC(udps_noport);
487 		if (m->m_flags & M_MCAST) {
488 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
489 			UDPSTAT_INC(udps_noportmcast);
490 			goto badunlocked;
491 		}
492 		if (V_udp_blackhole)
493 			goto badunlocked;
494 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
495 		return (IPPROTO_DONE);
496 	}
497 	INP_RLOCK_ASSERT(inp);
498 	up = intoudpcb(inp);
499 	if (cscov_partial) {
500 		if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
501 			INP_RUNLOCK(inp);
502 			m_freem(m);
503 			return (IPPROTO_DONE);
504 		}
505 	}
506 	UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
507 	if (udp6_append(inp, m, off, fromsa) == 0)
508 		INP_RUNLOCK(inp);
509 	return (IPPROTO_DONE);
510 
511 badheadlocked:
512 	INP_INFO_RUNLOCK_ET(pcbinfo, et);
513 badunlocked:
514 	if (m)
515 		m_freem(m);
516 	return (IPPROTO_DONE);
517 }
518 
519 static void
520 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
521     struct inpcbinfo *pcbinfo)
522 {
523 	struct udphdr uh;
524 	struct ip6_hdr *ip6;
525 	struct mbuf *m;
526 	int off = 0;
527 	struct ip6ctlparam *ip6cp = NULL;
528 	const struct sockaddr_in6 *sa6_src = NULL;
529 	void *cmdarg;
530 	struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
531 	struct udp_portonly {
532 		u_int16_t uh_sport;
533 		u_int16_t uh_dport;
534 	} *uhp;
535 
536 	if (sa->sa_family != AF_INET6 ||
537 	    sa->sa_len != sizeof(struct sockaddr_in6))
538 		return;
539 
540 	if ((unsigned)cmd >= PRC_NCMDS)
541 		return;
542 	if (PRC_IS_REDIRECT(cmd))
543 		notify = in6_rtchange, d = NULL;
544 	else if (cmd == PRC_HOSTDEAD)
545 		d = NULL;
546 	else if (inet6ctlerrmap[cmd] == 0)
547 		return;
548 
549 	/* if the parameter is from icmp6, decode it. */
550 	if (d != NULL) {
551 		ip6cp = (struct ip6ctlparam *)d;
552 		m = ip6cp->ip6c_m;
553 		ip6 = ip6cp->ip6c_ip6;
554 		off = ip6cp->ip6c_off;
555 		cmdarg = ip6cp->ip6c_cmdarg;
556 		sa6_src = ip6cp->ip6c_src;
557 	} else {
558 		m = NULL;
559 		ip6 = NULL;
560 		cmdarg = NULL;
561 		sa6_src = &sa6_any;
562 	}
563 
564 	if (ip6) {
565 		/*
566 		 * XXX: We assume that when IPV6 is non NULL,
567 		 * M and OFF are valid.
568 		 */
569 
570 		/* Check if we can safely examine src and dst ports. */
571 		if (m->m_pkthdr.len < off + sizeof(*uhp))
572 			return;
573 
574 		bzero(&uh, sizeof(uh));
575 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
576 
577 		if (!PRC_IS_REDIRECT(cmd)) {
578 			/* Check to see if its tunneled */
579 			struct inpcb *inp;
580 			inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_dst,
581 			    uh.uh_dport, &ip6->ip6_src, uh.uh_sport,
582 			    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
583 			    m->m_pkthdr.rcvif, m);
584 			if (inp != NULL) {
585 				struct udpcb *up;
586 
587 				up = intoudpcb(inp);
588 				if (up->u_icmp_func) {
589 					/* Yes it is. */
590 					INP_RUNLOCK(inp);
591 					(*up->u_icmp_func)(cmd, (struct sockaddr *)ip6cp->ip6c_src,
592 					      d, up->u_tun_ctx);
593 					return;
594 				} else {
595 					/* Can't find it. */
596 					INP_RUNLOCK(inp);
597 				}
598 			}
599 		}
600 		(void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
601 		    (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
602 		    cmdarg, notify);
603 	} else
604 		(void)in6_pcbnotify(pcbinfo, sa, 0,
605 		    (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
606 }
607 
608 void
609 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
610 {
611 
612 	return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
613 }
614 
615 void
616 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
617 {
618 
619 	return (udp6_common_ctlinput(cmd, sa, d, &V_ulitecbinfo));
620 }
621 
622 static int
623 udp6_getcred(SYSCTL_HANDLER_ARGS)
624 {
625 	struct xucred xuc;
626 	struct sockaddr_in6 addrs[2];
627 	struct inpcb *inp;
628 	int error;
629 
630 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
631 	if (error)
632 		return (error);
633 
634 	if (req->newlen != sizeof(addrs))
635 		return (EINVAL);
636 	if (req->oldlen != sizeof(struct xucred))
637 		return (EINVAL);
638 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
639 	if (error)
640 		return (error);
641 	if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
642 	    (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
643 		return (error);
644 	}
645 	inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
646 	    addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
647 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
648 	if (inp != NULL) {
649 		INP_RLOCK_ASSERT(inp);
650 		if (inp->inp_socket == NULL)
651 			error = ENOENT;
652 		if (error == 0)
653 			error = cr_canseesocket(req->td->td_ucred,
654 			    inp->inp_socket);
655 		if (error == 0)
656 			cru2x(inp->inp_cred, &xuc);
657 		INP_RUNLOCK(inp);
658 	} else
659 		error = ENOENT;
660 	if (error == 0)
661 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
662 	return (error);
663 }
664 
665 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
666     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
667 
668 static int
669 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
670     struct mbuf *control, struct thread *td)
671 {
672 	u_int32_t ulen = m->m_pkthdr.len;
673 	u_int32_t plen = sizeof(struct udphdr) + ulen;
674 	struct ip6_hdr *ip6;
675 	struct udphdr *udp6;
676 	struct in6_addr *laddr, *faddr, in6a;
677 	struct sockaddr_in6 *sin6 = NULL;
678 	int cscov_partial = 0;
679 	int scope_ambiguous = 0;
680 	u_short fport;
681 	int error = 0;
682 	uint8_t nxt;
683 	uint16_t cscov = 0;
684 	struct ip6_pktopts *optp, opt;
685 	int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
686 	int flags;
687 	struct sockaddr_in6 tmp;
688 
689 	INP_WLOCK_ASSERT(inp);
690 	INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
691 
692 	if (addr6) {
693 		/* addr6 has been validated in udp6_send(). */
694 		sin6 = (struct sockaddr_in6 *)addr6;
695 
696 		/* protect *sin6 from overwrites */
697 		tmp = *sin6;
698 		sin6 = &tmp;
699 
700 		/*
701 		 * Application should provide a proper zone ID or the use of
702 		 * default zone IDs should be enabled.  Unfortunately, some
703 		 * applications do not behave as it should, so we need a
704 		 * workaround.  Even if an appropriate ID is not determined,
705 		 * we'll see if we can determine the outgoing interface.  If we
706 		 * can, determine the zone ID based on the interface below.
707 		 */
708 		if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
709 			scope_ambiguous = 1;
710 		if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
711 			return (error);
712 	}
713 
714 	nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
715 	    IPPROTO_UDP : IPPROTO_UDPLITE;
716 	if (control) {
717 		if ((error = ip6_setpktopts(control, &opt,
718 		    inp->in6p_outputopts, td->td_ucred, nxt)) != 0)
719 			goto release;
720 		optp = &opt;
721 	} else
722 		optp = inp->in6p_outputopts;
723 
724 	if (sin6) {
725 		faddr = &sin6->sin6_addr;
726 
727 		/*
728 		 * Since we saw no essential reason for calling in_pcbconnect,
729 		 * we get rid of such kind of logic, and call in6_selectsrc
730 		 * and in6_pcbsetport in order to fill in the local address
731 		 * and the local port.
732 		 */
733 		if (sin6->sin6_port == 0) {
734 			error = EADDRNOTAVAIL;
735 			goto release;
736 		}
737 
738 		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
739 			/* how about ::ffff:0.0.0.0 case? */
740 			error = EISCONN;
741 			goto release;
742 		}
743 
744 		fport = sin6->sin6_port; /* allow 0 port */
745 
746 		if (IN6_IS_ADDR_V4MAPPED(faddr)) {
747 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
748 				/*
749 				 * I believe we should explicitly discard the
750 				 * packet when mapped addresses are disabled,
751 				 * rather than send the packet as an IPv6 one.
752 				 * If we chose the latter approach, the packet
753 				 * might be sent out on the wire based on the
754 				 * default route, the situation which we'd
755 				 * probably want to avoid.
756 				 * (20010421 jinmei@kame.net)
757 				 */
758 				error = EINVAL;
759 				goto release;
760 			}
761 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
762 			    !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
763 				/*
764 				 * when remote addr is an IPv4-mapped address,
765 				 * local addr should not be an IPv6 address,
766 				 * since you cannot determine how to map IPv6
767 				 * source address to IPv4.
768 				 */
769 				error = EINVAL;
770 				goto release;
771 			}
772 
773 			af = AF_INET;
774 		}
775 
776 		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
777 			error = in6_selectsrc_socket(sin6, optp, inp,
778 			    td->td_ucred, scope_ambiguous, &in6a, NULL);
779 			if (error)
780 				goto release;
781 			laddr = &in6a;
782 		} else
783 			laddr = &inp->in6p_laddr;	/* XXX */
784 		if (laddr == NULL) {
785 			if (error == 0)
786 				error = EADDRNOTAVAIL;
787 			goto release;
788 		}
789 		if (inp->inp_lport == 0 &&
790 		    (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
791 			/* Undo an address bind that may have occurred. */
792 			inp->in6p_laddr = in6addr_any;
793 			goto release;
794 		}
795 	} else {
796 		if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
797 			error = ENOTCONN;
798 			goto release;
799 		}
800 		if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
801 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
802 				/*
803 				 * XXX: this case would happen when the
804 				 * application sets the V6ONLY flag after
805 				 * connecting the foreign address.
806 				 * Such applications should be fixed,
807 				 * so we bark here.
808 				 */
809 				log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
810 				    "option was set for a connected socket\n");
811 				error = EINVAL;
812 				goto release;
813 			} else
814 				af = AF_INET;
815 		}
816 		laddr = &inp->in6p_laddr;
817 		faddr = &inp->in6p_faddr;
818 		fport = inp->inp_fport;
819 	}
820 
821 	if (af == AF_INET)
822 		hlen = sizeof(struct ip);
823 
824 	/*
825 	 * Calculate data length and get a mbuf
826 	 * for UDP and IP6 headers.
827 	 */
828 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
829 	if (m == NULL) {
830 		error = ENOBUFS;
831 		goto release;
832 	}
833 
834 	/*
835 	 * Stuff checksum and output datagram.
836 	 */
837 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
838 	udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
839 	udp6->uh_dport = fport;
840 	if (nxt == IPPROTO_UDPLITE) {
841 		struct udpcb *up;
842 
843 		up = intoudpcb(inp);
844 		cscov = up->u_txcslen;
845 		if (cscov >= plen)
846 			cscov = 0;
847 		udp6->uh_ulen = htons(cscov);
848 		/*
849 		 * For UDP-Lite, checksum coverage length of zero means
850 		 * the entire UDPLite packet is covered by the checksum.
851 		 */
852 		cscov_partial = (cscov == 0) ? 0 : 1;
853 	} else if (plen <= 0xffff)
854 		udp6->uh_ulen = htons((u_short)plen);
855 	else
856 		udp6->uh_ulen = 0;
857 	udp6->uh_sum = 0;
858 
859 	switch (af) {
860 	case AF_INET6:
861 		ip6 = mtod(m, struct ip6_hdr *);
862 		ip6->ip6_flow	= inp->inp_flow & IPV6_FLOWINFO_MASK;
863 		ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
864 		ip6->ip6_vfc	|= IPV6_VERSION;
865 		ip6->ip6_plen	= htons((u_short)plen);
866 		ip6->ip6_nxt	= nxt;
867 		ip6->ip6_hlim	= in6_selecthlim(inp, NULL);
868 		ip6->ip6_src	= *laddr;
869 		ip6->ip6_dst	= *faddr;
870 
871 		if (cscov_partial) {
872 			if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
873 			    sizeof(struct ip6_hdr), plen, cscov)) == 0)
874 				udp6->uh_sum = 0xffff;
875 		} else {
876 			udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
877 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
878 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
879 		}
880 
881 #ifdef	RSS
882 		{
883 			uint32_t hash_val, hash_type;
884 			uint8_t pr;
885 
886 			pr = inp->inp_socket->so_proto->pr_protocol;
887 			/*
888 			 * Calculate an appropriate RSS hash for UDP and
889 			 * UDP Lite.
890 			 *
891 			 * The called function will take care of figuring out
892 			 * whether a 2-tuple or 4-tuple hash is required based
893 			 * on the currently configured scheme.
894 			 *
895 			 * Later later on connected socket values should be
896 			 * cached in the inpcb and reused, rather than constantly
897 			 * re-calculating it.
898 			 *
899 			 * UDP Lite is a different protocol number and will
900 			 * likely end up being hashed as a 2-tuple until
901 			 * RSS / NICs grow UDP Lite protocol awareness.
902 			 */
903 			if (rss_proto_software_hash_v6(faddr, laddr, fport,
904 			    inp->inp_lport, pr, &hash_val, &hash_type) == 0) {
905 				m->m_pkthdr.flowid = hash_val;
906 				M_HASHTYPE_SET(m, hash_type);
907 			}
908 		}
909 #endif
910 		flags = 0;
911 #ifdef	RSS
912 		/*
913 		 * Don't override with the inp cached flowid.
914 		 *
915 		 * Until the whole UDP path is vetted, it may actually
916 		 * be incorrect.
917 		 */
918 		flags |= IP_NODEFAULTFLOWID;
919 #endif
920 
921 		UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
922 		UDPSTAT_INC(udps_opackets);
923 		error = ip6_output(m, optp, &inp->inp_route6, flags,
924 		    inp->in6p_moptions, NULL, inp);
925 		break;
926 	case AF_INET:
927 		error = EAFNOSUPPORT;
928 		goto release;
929 	}
930 	goto releaseopt;
931 
932 release:
933 	m_freem(m);
934 
935 releaseopt:
936 	if (control) {
937 		ip6_clearpktopts(&opt, -1);
938 		m_freem(control);
939 	}
940 	return (error);
941 }
942 
943 static void
944 udp6_abort(struct socket *so)
945 {
946 	struct inpcb *inp;
947 	struct inpcbinfo *pcbinfo;
948 
949 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
950 	inp = sotoinpcb(so);
951 	KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
952 
953 	INP_WLOCK(inp);
954 #ifdef INET
955 	if (inp->inp_vflag & INP_IPV4) {
956 		struct pr_usrreqs *pru;
957 		uint8_t nxt;
958 
959 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
960 		    IPPROTO_UDP : IPPROTO_UDPLITE;
961 		INP_WUNLOCK(inp);
962 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
963 		(*pru->pru_abort)(so);
964 		return;
965 	}
966 #endif
967 
968 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
969 		INP_HASH_WLOCK(pcbinfo);
970 		in6_pcbdisconnect(inp);
971 		inp->in6p_laddr = in6addr_any;
972 		INP_HASH_WUNLOCK(pcbinfo);
973 		soisdisconnected(so);
974 	}
975 	INP_WUNLOCK(inp);
976 }
977 
978 static int
979 udp6_attach(struct socket *so, int proto, struct thread *td)
980 {
981 	struct inpcb *inp;
982 	struct inpcbinfo *pcbinfo;
983 	int error;
984 
985 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
986 	inp = sotoinpcb(so);
987 	KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
988 
989 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
990 		error = soreserve(so, udp_sendspace, udp_recvspace);
991 		if (error)
992 			return (error);
993 	}
994 	INP_INFO_WLOCK(pcbinfo);
995 	error = in_pcballoc(so, pcbinfo);
996 	if (error) {
997 		INP_INFO_WUNLOCK(pcbinfo);
998 		return (error);
999 	}
1000 	inp = (struct inpcb *)so->so_pcb;
1001 	inp->inp_vflag |= INP_IPV6;
1002 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
1003 		inp->inp_vflag |= INP_IPV4;
1004 	inp->in6p_hops = -1;	/* use kernel default */
1005 	inp->in6p_cksum = -1;	/* just to be sure */
1006 	/*
1007 	 * XXX: ugly!!
1008 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
1009 	 * because the socket may be bound to an IPv6 wildcard address,
1010 	 * which may match an IPv4-mapped IPv6 address.
1011 	 */
1012 	inp->inp_ip_ttl = V_ip_defttl;
1013 
1014 	error = udp_newudpcb(inp);
1015 	if (error) {
1016 		in_pcbdetach(inp);
1017 		in_pcbfree(inp);
1018 		INP_INFO_WUNLOCK(pcbinfo);
1019 		return (error);
1020 	}
1021 	INP_WUNLOCK(inp);
1022 	INP_INFO_WUNLOCK(pcbinfo);
1023 	return (0);
1024 }
1025 
1026 static int
1027 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1028 {
1029 	struct inpcb *inp;
1030 	struct inpcbinfo *pcbinfo;
1031 	int error;
1032 
1033 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1034 	inp = sotoinpcb(so);
1035 	KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
1036 
1037 	INP_WLOCK(inp);
1038 	INP_HASH_WLOCK(pcbinfo);
1039 	inp->inp_vflag &= ~INP_IPV4;
1040 	inp->inp_vflag |= INP_IPV6;
1041 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1042 		struct sockaddr_in6 *sin6_p;
1043 
1044 		sin6_p = (struct sockaddr_in6 *)nam;
1045 
1046 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
1047 			inp->inp_vflag |= INP_IPV4;
1048 #ifdef INET
1049 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
1050 			struct sockaddr_in sin;
1051 
1052 			in6_sin6_2_sin(&sin, sin6_p);
1053 			inp->inp_vflag |= INP_IPV4;
1054 			inp->inp_vflag &= ~INP_IPV6;
1055 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
1056 			    td->td_ucred);
1057 			goto out;
1058 		}
1059 #endif
1060 	}
1061 
1062 	error = in6_pcbbind(inp, nam, td->td_ucred);
1063 #ifdef INET
1064 out:
1065 #endif
1066 	INP_HASH_WUNLOCK(pcbinfo);
1067 	INP_WUNLOCK(inp);
1068 	return (error);
1069 }
1070 
1071 static void
1072 udp6_close(struct socket *so)
1073 {
1074 	struct inpcb *inp;
1075 	struct inpcbinfo *pcbinfo;
1076 
1077 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1078 	inp = sotoinpcb(so);
1079 	KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
1080 
1081 	INP_WLOCK(inp);
1082 #ifdef INET
1083 	if (inp->inp_vflag & INP_IPV4) {
1084 		struct pr_usrreqs *pru;
1085 		uint8_t nxt;
1086 
1087 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1088 		    IPPROTO_UDP : IPPROTO_UDPLITE;
1089 		INP_WUNLOCK(inp);
1090 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1091 		(*pru->pru_disconnect)(so);
1092 		return;
1093 	}
1094 #endif
1095 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1096 		INP_HASH_WLOCK(pcbinfo);
1097 		in6_pcbdisconnect(inp);
1098 		inp->in6p_laddr = in6addr_any;
1099 		INP_HASH_WUNLOCK(pcbinfo);
1100 		soisdisconnected(so);
1101 	}
1102 	INP_WUNLOCK(inp);
1103 }
1104 
1105 static int
1106 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1107 {
1108 	struct inpcb *inp;
1109 	struct inpcbinfo *pcbinfo;
1110 	struct sockaddr_in6 *sin6;
1111 	int error;
1112 
1113 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1114 	inp = sotoinpcb(so);
1115 	sin6 = (struct sockaddr_in6 *)nam;
1116 	KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1117 
1118 	/*
1119 	 * XXXRW: Need to clarify locking of v4/v6 flags.
1120 	 */
1121 	INP_WLOCK(inp);
1122 #ifdef INET
1123 	if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1124 		struct sockaddr_in sin;
1125 
1126 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1127 			error = EINVAL;
1128 			goto out;
1129 		}
1130 		if ((inp->inp_vflag & INP_IPV4) == 0) {
1131 			error = EAFNOSUPPORT;
1132 			goto out;
1133 		}
1134 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1135 			error = EISCONN;
1136 			goto out;
1137 		}
1138 		in6_sin6_2_sin(&sin, sin6);
1139 		inp->inp_vflag |= INP_IPV4;
1140 		inp->inp_vflag &= ~INP_IPV6;
1141 		error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1142 		if (error != 0)
1143 			goto out;
1144 		INP_HASH_WLOCK(pcbinfo);
1145 		error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1146 		    td->td_ucred);
1147 		INP_HASH_WUNLOCK(pcbinfo);
1148 		if (error == 0)
1149 			soisconnected(so);
1150 		goto out;
1151 	} else {
1152 		if ((inp->inp_vflag & INP_IPV6) == 0) {
1153 			error = EAFNOSUPPORT;
1154 			goto out;
1155 		}
1156 	}
1157 #endif
1158 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1159 		error = EISCONN;
1160 		goto out;
1161 	}
1162 	inp->inp_vflag &= ~INP_IPV4;
1163 	inp->inp_vflag |= INP_IPV6;
1164 	error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1165 	if (error != 0)
1166 		goto out;
1167 	INP_HASH_WLOCK(pcbinfo);
1168 	error = in6_pcbconnect(inp, nam, td->td_ucred);
1169 	INP_HASH_WUNLOCK(pcbinfo);
1170 	if (error == 0)
1171 		soisconnected(so);
1172 out:
1173 	INP_WUNLOCK(inp);
1174 	return (error);
1175 }
1176 
1177 static void
1178 udp6_detach(struct socket *so)
1179 {
1180 	struct inpcb *inp;
1181 	struct inpcbinfo *pcbinfo;
1182 	struct udpcb *up;
1183 
1184 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1185 	inp = sotoinpcb(so);
1186 	KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1187 
1188 	INP_INFO_WLOCK(pcbinfo);
1189 	INP_WLOCK(inp);
1190 	up = intoudpcb(inp);
1191 	KASSERT(up != NULL, ("%s: up == NULL", __func__));
1192 	in_pcbdetach(inp);
1193 	in_pcbfree(inp);
1194 	INP_INFO_WUNLOCK(pcbinfo);
1195 	udp_discardcb(up);
1196 }
1197 
1198 static int
1199 udp6_disconnect(struct socket *so)
1200 {
1201 	struct inpcb *inp;
1202 	struct inpcbinfo *pcbinfo;
1203 
1204 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1205 	inp = sotoinpcb(so);
1206 	KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1207 
1208 	INP_WLOCK(inp);
1209 #ifdef INET
1210 	if (inp->inp_vflag & INP_IPV4) {
1211 		struct pr_usrreqs *pru;
1212 		uint8_t nxt;
1213 
1214 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1215 		    IPPROTO_UDP : IPPROTO_UDPLITE;
1216 		INP_WUNLOCK(inp);
1217 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1218 		(void)(*pru->pru_disconnect)(so);
1219 		return (0);
1220 	}
1221 #endif
1222 
1223 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1224 		INP_WUNLOCK(inp);
1225 		return (ENOTCONN);
1226 	}
1227 
1228 	INP_HASH_WLOCK(pcbinfo);
1229 	in6_pcbdisconnect(inp);
1230 	inp->in6p_laddr = in6addr_any;
1231 	INP_HASH_WUNLOCK(pcbinfo);
1232 	SOCK_LOCK(so);
1233 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1234 	SOCK_UNLOCK(so);
1235 	INP_WUNLOCK(inp);
1236 	return (0);
1237 }
1238 
1239 static int
1240 udp6_send(struct socket *so, int flags, struct mbuf *m,
1241     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1242 {
1243 	struct inpcb *inp;
1244 	struct inpcbinfo *pcbinfo;
1245 	int error = 0;
1246 
1247 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1248 	inp = sotoinpcb(so);
1249 	KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1250 
1251 	INP_WLOCK(inp);
1252 	if (addr) {
1253 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1254 			error = EINVAL;
1255 			goto bad;
1256 		}
1257 		if (addr->sa_family != AF_INET6) {
1258 			error = EAFNOSUPPORT;
1259 			goto bad;
1260 		}
1261 	}
1262 
1263 #ifdef INET
1264 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1265 		int hasv4addr;
1266 		struct sockaddr_in6 *sin6 = NULL;
1267 
1268 		if (addr == NULL)
1269 			hasv4addr = (inp->inp_vflag & INP_IPV4);
1270 		else {
1271 			sin6 = (struct sockaddr_in6 *)addr;
1272 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1273 			    ? 1 : 0;
1274 		}
1275 		if (hasv4addr) {
1276 			struct pr_usrreqs *pru;
1277 			uint8_t nxt;
1278 
1279 			nxt = (inp->inp_socket->so_proto->pr_protocol ==
1280 			    IPPROTO_UDP) ? IPPROTO_UDP : IPPROTO_UDPLITE;
1281 			/*
1282 			 * XXXRW: We release UDP-layer locks before calling
1283 			 * udp_send() in order to avoid recursion.  However,
1284 			 * this does mean there is a short window where inp's
1285 			 * fields are unstable.  Could this lead to a
1286 			 * potential race in which the factors causing us to
1287 			 * select the UDPv4 output routine are invalidated?
1288 			 */
1289 			INP_WUNLOCK(inp);
1290 			if (sin6)
1291 				in6_sin6_2_sin_in_sock(addr);
1292 			pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1293 			/* addr will just be freed in sendit(). */
1294 			return ((*pru->pru_send)(so, flags, m, addr, control,
1295 			    td));
1296 		}
1297 	}
1298 #endif
1299 #ifdef MAC
1300 	mac_inpcb_create_mbuf(inp, m);
1301 #endif
1302 	INP_HASH_WLOCK(pcbinfo);
1303 	error = udp6_output(inp, m, addr, control, td);
1304 	INP_HASH_WUNLOCK(pcbinfo);
1305 	INP_WUNLOCK(inp);
1306 	return (error);
1307 
1308 bad:
1309 	INP_WUNLOCK(inp);
1310 	m_freem(m);
1311 	return (error);
1312 }
1313 
1314 struct pr_usrreqs udp6_usrreqs = {
1315 	.pru_abort =		udp6_abort,
1316 	.pru_attach =		udp6_attach,
1317 	.pru_bind =		udp6_bind,
1318 	.pru_connect =		udp6_connect,
1319 	.pru_control =		in6_control,
1320 	.pru_detach =		udp6_detach,
1321 	.pru_disconnect =	udp6_disconnect,
1322 	.pru_peeraddr =		in6_mapped_peeraddr,
1323 	.pru_send =		udp6_send,
1324 	.pru_shutdown =		udp_shutdown,
1325 	.pru_sockaddr =		in6_mapped_sockaddr,
1326 	.pru_soreceive =	soreceive_dgram,
1327 	.pru_sosend =		sosend_dgram,
1328 	.pru_sosetlabel =	in_pcbsosetlabel,
1329 	.pru_close =		udp6_close
1330 };
1331