xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision efe3b0de1438e7a8473d92f2be57072394559e3c)
1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * Copyright (c) 2010-2011 Juniper Networks, Inc.
4  * Copyright (c) 2014 Kevin Lo
5  * All rights reserved.
6  *
7  * Portions of this software were developed by Robert N. M. Watson under
8  * contract to Juniper Networks, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the project nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	$KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei Exp $
35  *	$KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $
36  */
37 
38 /*-
39  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
40  *	The Regents of the University of California.
41  * All rights reserved.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 4. Neither the name of the University nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
68  */
69 
70 #include <sys/cdefs.h>
71 __FBSDID("$FreeBSD$");
72 
73 #include "opt_inet.h"
74 #include "opt_inet6.h"
75 #include "opt_ipsec.h"
76 #include "opt_rss.h"
77 
78 #include <sys/param.h>
79 #include <sys/jail.h>
80 #include <sys/kernel.h>
81 #include <sys/lock.h>
82 #include <sys/mbuf.h>
83 #include <sys/priv.h>
84 #include <sys/proc.h>
85 #include <sys/protosw.h>
86 #include <sys/sdt.h>
87 #include <sys/signalvar.h>
88 #include <sys/socket.h>
89 #include <sys/socketvar.h>
90 #include <sys/sx.h>
91 #include <sys/sysctl.h>
92 #include <sys/syslog.h>
93 #include <sys/systm.h>
94 
95 #include <net/if.h>
96 #include <net/if_var.h>
97 #include <net/if_types.h>
98 #include <net/route.h>
99 #include <net/rss_config.h>
100 
101 #include <netinet/in.h>
102 #include <netinet/in_kdtrace.h>
103 #include <netinet/in_pcb.h>
104 #include <netinet/in_systm.h>
105 #include <netinet/in_var.h>
106 #include <netinet/ip.h>
107 #include <netinet/ip_icmp.h>
108 #include <netinet/ip6.h>
109 #include <netinet/icmp_var.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;
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,
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 	m_adj(n, off + sizeof(struct udphdr));
177 
178 	so = inp->inp_socket;
179 	SOCKBUF_LOCK(&so->so_rcv);
180 	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
181 	    opts) == 0) {
182 		SOCKBUF_UNLOCK(&so->so_rcv);
183 		m_freem(n);
184 		if (opts)
185 			m_freem(opts);
186 		UDPSTAT_INC(udps_fullsock);
187 	} else
188 		sorwakeup_locked(so);
189 	return (0);
190 }
191 
192 int
193 udp6_input(struct mbuf **mp, int *offp, int proto)
194 {
195 	struct mbuf *m = *mp;
196 	struct ifnet *ifp;
197 	struct ip6_hdr *ip6;
198 	struct udphdr *uh;
199 	struct inpcb *inp;
200 	struct inpcbinfo *pcbinfo;
201 	struct udpcb *up;
202 	int off = *offp;
203 	int cscov_partial;
204 	int plen, ulen;
205 	struct sockaddr_in6 fromsa;
206 	struct m_tag *fwd_tag;
207 	uint16_t uh_sum;
208 	uint8_t nxt;
209 
210 	ifp = m->m_pkthdr.rcvif;
211 	ip6 = mtod(m, struct ip6_hdr *);
212 
213 #ifndef PULLDOWN_TEST
214 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
215 	ip6 = mtod(m, struct ip6_hdr *);
216 	uh = (struct udphdr *)((caddr_t)ip6 + off);
217 #else
218 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
219 	if (!uh)
220 		return (IPPROTO_DONE);
221 #endif
222 
223 	UDPSTAT_INC(udps_ipackets);
224 
225 	/*
226 	 * Destination port of 0 is illegal, based on RFC768.
227 	 */
228 	if (uh->uh_dport == 0)
229 		goto badunlocked;
230 
231 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
232 	ulen = ntohs((u_short)uh->uh_ulen);
233 
234 	nxt = proto;
235 	cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
236 	if (nxt == IPPROTO_UDPLITE) {
237 		/* Zero means checksum over the complete packet. */
238 		if (ulen == 0)
239 			ulen = plen;
240 		if (ulen == plen)
241 			cscov_partial = 0;
242 		if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
243 			/* XXX: What is the right UDPLite MIB counter? */
244 			goto badunlocked;
245 		}
246 		if (uh->uh_sum == 0) {
247 			/* XXX: What is the right UDPLite MIB counter? */
248 			goto badunlocked;
249 		}
250 	} else {
251 		if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
252 			UDPSTAT_INC(udps_badlen);
253 			goto badunlocked;
254 		}
255 		if (uh->uh_sum == 0) {
256 			UDPSTAT_INC(udps_nosum);
257 			goto badunlocked;
258 		}
259 	}
260 
261 	if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
262 	    !cscov_partial) {
263 		if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
264 			uh_sum = m->m_pkthdr.csum_data;
265 		else
266 			uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
267 			    m->m_pkthdr.csum_data);
268 		uh_sum ^= 0xffff;
269 	} else
270 		uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
271 
272 	if (uh_sum != 0) {
273 		UDPSTAT_INC(udps_badsum);
274 		goto badunlocked;
275 	}
276 
277 	/*
278 	 * Construct sockaddr format source address.
279 	 */
280 	init_sin6(&fromsa, m);
281 	fromsa.sin6_port = uh->uh_sport;
282 
283 	pcbinfo = udp_get_inpcbinfo(nxt);
284 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
285 		struct inpcb *last;
286 		struct inpcbhead *pcblist;
287 		struct ip6_moptions *imo;
288 
289 		INP_INFO_RLOCK(pcbinfo);
290 		/*
291 		 * In the event that laddr should be set to the link-local
292 		 * address (this happens in RIPng), the multicast address
293 		 * specified in the received packet will not match laddr.  To
294 		 * handle this situation, matching is relaxed if the
295 		 * receiving interface is the same as one specified in the
296 		 * socket and if the destination multicast address matches
297 		 * one of the multicast groups specified in the socket.
298 		 */
299 
300 		/*
301 		 * KAME note: traditionally we dropped udpiphdr from mbuf
302 		 * here.  We need udphdr for IPsec processing so we do that
303 		 * later.
304 		 */
305 		pcblist = udp_get_pcblist(nxt);
306 		last = NULL;
307 		LIST_FOREACH(inp, pcblist, inp_list) {
308 			if ((inp->inp_vflag & INP_IPV6) == 0)
309 				continue;
310 			if (inp->inp_lport != uh->uh_dport)
311 				continue;
312 			if (inp->inp_fport != 0 &&
313 			    inp->inp_fport != uh->uh_sport)
314 				continue;
315 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
316 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
317 							&ip6->ip6_dst))
318 					continue;
319 			}
320 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
321 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
322 							&ip6->ip6_src) ||
323 				    inp->inp_fport != uh->uh_sport)
324 					continue;
325 			}
326 
327 			/*
328 			 * XXXRW: Because we weren't holding either the inpcb
329 			 * or the hash lock when we checked for a match
330 			 * before, we should probably recheck now that the
331 			 * inpcb lock is (supposed to be) held.
332 			 */
333 
334 			/*
335 			 * Handle socket delivery policy for any-source
336 			 * and source-specific multicast. [RFC3678]
337 			 */
338 			imo = inp->in6p_moptions;
339 			if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
340 				struct sockaddr_in6	 mcaddr;
341 				int			 blocked;
342 
343 				INP_RLOCK(inp);
344 
345 				bzero(&mcaddr, sizeof(struct sockaddr_in6));
346 				mcaddr.sin6_len = sizeof(struct sockaddr_in6);
347 				mcaddr.sin6_family = AF_INET6;
348 				mcaddr.sin6_addr = ip6->ip6_dst;
349 
350 				blocked = im6o_mc_filter(imo, ifp,
351 					(struct sockaddr *)&mcaddr,
352 					(struct sockaddr *)&fromsa);
353 				if (blocked != MCAST_PASS) {
354 					if (blocked == MCAST_NOTGMEMBER)
355 						IP6STAT_INC(ip6s_notmember);
356 					if (blocked == MCAST_NOTSMEMBER ||
357 					    blocked == MCAST_MUTED)
358 						UDPSTAT_INC(udps_filtermcast);
359 					INP_RUNLOCK(inp); /* XXX */
360 					continue;
361 				}
362 
363 				INP_RUNLOCK(inp);
364 			}
365 			if (last != NULL) {
366 				struct mbuf *n;
367 
368 				if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) !=
369 				    NULL) {
370 					INP_RLOCK(last);
371 					UDP_PROBE(receive, NULL, last, ip6,
372 					    last, uh);
373 					if (udp6_append(last, n, off, &fromsa))
374 						goto inp_lost;
375 					INP_RUNLOCK(last);
376 				}
377 			}
378 			last = inp;
379 			/*
380 			 * Don't look for additional matches if this one does
381 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
382 			 * socket options set.  This heuristic avoids
383 			 * searching through all pcbs in the common case of a
384 			 * non-shared port.  It assumes that an application
385 			 * will never clear these options after setting them.
386 			 */
387 			if ((last->inp_socket->so_options &
388 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
389 				break;
390 		}
391 
392 		if (last == NULL) {
393 			/*
394 			 * No matching pcb found; discard datagram.  (No need
395 			 * to send an ICMP Port Unreachable for a broadcast
396 			 * or multicast datgram.)
397 			 */
398 			UDPSTAT_INC(udps_noport);
399 			UDPSTAT_INC(udps_noportmcast);
400 			goto badheadlocked;
401 		}
402 		INP_RLOCK(last);
403 		INP_INFO_RUNLOCK(pcbinfo);
404 		UDP_PROBE(receive, NULL, last, ip6, last, uh);
405 		if (udp6_append(last, m, off, &fromsa) == 0)
406 			INP_RUNLOCK(last);
407 	inp_lost:
408 		return (IPPROTO_DONE);
409 	}
410 	/*
411 	 * Locate pcb for datagram.
412 	 */
413 
414 	/*
415 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
416 	 */
417 	if ((m->m_flags & M_IP6_NEXTHOP) &&
418 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
419 		struct sockaddr_in6 *next_hop6;
420 
421 		next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
422 
423 		/*
424 		 * Transparently forwarded. Pretend to be the destination.
425 		 * Already got one like this?
426 		 */
427 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
428 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
429 		    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
430 		if (!inp) {
431 			/*
432 			 * It's new.  Try to find the ambushing socket.
433 			 * Because we've rewritten the destination address,
434 			 * any hardware-generated hash is ignored.
435 			 */
436 			inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
437 			    uh->uh_sport, &next_hop6->sin6_addr,
438 			    next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
439 			    uh->uh_dport, INPLOOKUP_WILDCARD |
440 			    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
441 		}
442 		/* Remove the tag from the packet. We don't need it anymore. */
443 		m_tag_delete(m, fwd_tag);
444 		m->m_flags &= ~M_IP6_NEXTHOP;
445 	} else
446 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
447 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
448 		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
449 		    m->m_pkthdr.rcvif, m);
450 	if (inp == NULL) {
451 		if (udp_log_in_vain) {
452 			char ip6bufs[INET6_ADDRSTRLEN];
453 			char ip6bufd[INET6_ADDRSTRLEN];
454 
455 			log(LOG_INFO,
456 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
457 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
458 			    ntohs(uh->uh_dport),
459 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
460 			    ntohs(uh->uh_sport));
461 		}
462 		UDPSTAT_INC(udps_noport);
463 		if (m->m_flags & M_MCAST) {
464 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
465 			UDPSTAT_INC(udps_noportmcast);
466 			goto badunlocked;
467 		}
468 		if (V_udp_blackhole)
469 			goto badunlocked;
470 		if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
471 			goto badunlocked;
472 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
473 		return (IPPROTO_DONE);
474 	}
475 	INP_RLOCK_ASSERT(inp);
476 	up = intoudpcb(inp);
477 	if (cscov_partial) {
478 		if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
479 			INP_RUNLOCK(inp);
480 			m_freem(m);
481 			return (IPPROTO_DONE);
482 		}
483 	}
484 	UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
485 	if (udp6_append(inp, m, off, &fromsa) == 0)
486 		INP_RUNLOCK(inp);
487 	return (IPPROTO_DONE);
488 
489 badheadlocked:
490 	INP_INFO_RUNLOCK(pcbinfo);
491 badunlocked:
492 	if (m)
493 		m_freem(m);
494 	return (IPPROTO_DONE);
495 }
496 
497 static void
498 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
499     struct inpcbinfo *pcbinfo)
500 {
501 	struct udphdr uh;
502 	struct ip6_hdr *ip6;
503 	struct mbuf *m;
504 	int off = 0;
505 	struct ip6ctlparam *ip6cp = NULL;
506 	const struct sockaddr_in6 *sa6_src = NULL;
507 	void *cmdarg;
508 	struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
509 	struct udp_portonly {
510 		u_int16_t uh_sport;
511 		u_int16_t uh_dport;
512 	} *uhp;
513 
514 	if (sa->sa_family != AF_INET6 ||
515 	    sa->sa_len != sizeof(struct sockaddr_in6))
516 		return;
517 
518 	if ((unsigned)cmd >= PRC_NCMDS)
519 		return;
520 	if (PRC_IS_REDIRECT(cmd))
521 		notify = in6_rtchange, d = NULL;
522 	else if (cmd == PRC_HOSTDEAD)
523 		d = NULL;
524 	else if (inet6ctlerrmap[cmd] == 0)
525 		return;
526 
527 	/* if the parameter is from icmp6, decode it. */
528 	if (d != NULL) {
529 		ip6cp = (struct ip6ctlparam *)d;
530 		m = ip6cp->ip6c_m;
531 		ip6 = ip6cp->ip6c_ip6;
532 		off = ip6cp->ip6c_off;
533 		cmdarg = ip6cp->ip6c_cmdarg;
534 		sa6_src = ip6cp->ip6c_src;
535 	} else {
536 		m = NULL;
537 		ip6 = NULL;
538 		cmdarg = NULL;
539 		sa6_src = &sa6_any;
540 	}
541 
542 	if (ip6) {
543 		/*
544 		 * XXX: We assume that when IPV6 is non NULL,
545 		 * M and OFF are valid.
546 		 */
547 
548 		/* Check if we can safely examine src and dst ports. */
549 		if (m->m_pkthdr.len < off + sizeof(*uhp))
550 			return;
551 
552 		bzero(&uh, sizeof(uh));
553 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
554 
555 		if (!PRC_IS_REDIRECT(cmd)) {
556 			/* Check to see if its tunneled */
557 			struct inpcb *inp;
558 			inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_dst,
559 			    uh.uh_dport, &ip6->ip6_src, uh.uh_sport,
560 			    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
561 			    m->m_pkthdr.rcvif, m);
562 			if (inp != NULL) {
563 				struct udpcb *up;
564 
565 				up = intoudpcb(inp);
566 				if (up->u_icmp_func) {
567 					/* Yes it is. */
568 					INP_RUNLOCK(inp);
569 					(*up->u_icmp_func)(cmd, (struct sockaddr *)ip6cp->ip6c_src,
570 					      d, up->u_tun_ctx);
571 					return;
572 				} else {
573 					/* Can't find it. */
574 					INP_RUNLOCK(inp);
575 				}
576 			}
577 		}
578 		(void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
579 		    (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
580 		    cmdarg, notify);
581 	} else
582 		(void)in6_pcbnotify(pcbinfo, sa, 0,
583 		    (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
584 }
585 
586 void
587 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
588 {
589 
590 	return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
591 }
592 
593 void
594 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
595 {
596 
597 	return (udp6_common_ctlinput(cmd, sa, d, &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 inpcb *inp;
606 	int error;
607 
608 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
609 	if (error)
610 		return (error);
611 
612 	if (req->newlen != sizeof(addrs))
613 		return (EINVAL);
614 	if (req->oldlen != sizeof(struct xucred))
615 		return (EINVAL);
616 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
617 	if (error)
618 		return (error);
619 	if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
620 	    (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
621 		return (error);
622 	}
623 	inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
624 	    addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
625 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
626 	if (inp != NULL) {
627 		INP_RLOCK_ASSERT(inp);
628 		if (inp->inp_socket == NULL)
629 			error = ENOENT;
630 		if (error == 0)
631 			error = cr_canseesocket(req->td->td_ucred,
632 			    inp->inp_socket);
633 		if (error == 0)
634 			cru2x(inp->inp_cred, &xuc);
635 		INP_RUNLOCK(inp);
636 	} else
637 		error = ENOENT;
638 	if (error == 0)
639 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
640 	return (error);
641 }
642 
643 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
644     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
645 
646 static int
647 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
648     struct mbuf *control, struct thread *td)
649 {
650 	u_int32_t ulen = m->m_pkthdr.len;
651 	u_int32_t plen = sizeof(struct udphdr) + ulen;
652 	struct ip6_hdr *ip6;
653 	struct udphdr *udp6;
654 	struct in6_addr *laddr, *faddr, in6a;
655 	struct sockaddr_in6 *sin6 = NULL;
656 	int cscov_partial = 0;
657 	int scope_ambiguous = 0;
658 	u_short fport;
659 	int error = 0;
660 	uint8_t nxt;
661 	uint16_t cscov = 0;
662 	struct ip6_pktopts *optp, opt;
663 	int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
664 	int flags;
665 	struct sockaddr_in6 tmp;
666 
667 	INP_WLOCK_ASSERT(inp);
668 	INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
669 
670 	if (addr6) {
671 		/* addr6 has been validated in udp6_send(). */
672 		sin6 = (struct sockaddr_in6 *)addr6;
673 
674 		/* protect *sin6 from overwrites */
675 		tmp = *sin6;
676 		sin6 = &tmp;
677 
678 		/*
679 		 * Application should provide a proper zone ID or the use of
680 		 * default zone IDs should be enabled.  Unfortunately, some
681 		 * applications do not behave as it should, so we need a
682 		 * workaround.  Even if an appropriate ID is not determined,
683 		 * we'll see if we can determine the outgoing interface.  If we
684 		 * can, determine the zone ID based on the interface below.
685 		 */
686 		if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
687 			scope_ambiguous = 1;
688 		if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
689 			return (error);
690 	}
691 
692 	nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
693 	    IPPROTO_UDP : IPPROTO_UDPLITE;
694 	if (control) {
695 		if ((error = ip6_setpktopts(control, &opt,
696 		    inp->in6p_outputopts, td->td_ucred, nxt)) != 0)
697 			goto release;
698 		optp = &opt;
699 	} else
700 		optp = inp->in6p_outputopts;
701 
702 	if (sin6) {
703 		faddr = &sin6->sin6_addr;
704 
705 		/*
706 		 * Since we saw no essential reason for calling in_pcbconnect,
707 		 * we get rid of such kind of logic, and call in6_selectsrc
708 		 * and in6_pcbsetport in order to fill in the local address
709 		 * and the local port.
710 		 */
711 		if (sin6->sin6_port == 0) {
712 			error = EADDRNOTAVAIL;
713 			goto release;
714 		}
715 
716 		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
717 			/* how about ::ffff:0.0.0.0 case? */
718 			error = EISCONN;
719 			goto release;
720 		}
721 
722 		fport = sin6->sin6_port; /* allow 0 port */
723 
724 		if (IN6_IS_ADDR_V4MAPPED(faddr)) {
725 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
726 				/*
727 				 * I believe we should explicitly discard the
728 				 * packet when mapped addresses are disabled,
729 				 * rather than send the packet as an IPv6 one.
730 				 * If we chose the latter approach, the packet
731 				 * might be sent out on the wire based on the
732 				 * default route, the situation which we'd
733 				 * probably want to avoid.
734 				 * (20010421 jinmei@kame.net)
735 				 */
736 				error = EINVAL;
737 				goto release;
738 			}
739 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
740 			    !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
741 				/*
742 				 * when remote addr is an IPv4-mapped address,
743 				 * local addr should not be an IPv6 address,
744 				 * since you cannot determine how to map IPv6
745 				 * source address to IPv4.
746 				 */
747 				error = EINVAL;
748 				goto release;
749 			}
750 
751 			af = AF_INET;
752 		}
753 
754 		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
755 			error = in6_selectsrc_socket(sin6, optp, inp,
756 			    td->td_ucred, scope_ambiguous, &in6a, NULL);
757 			if (error)
758 				goto release;
759 			laddr = &in6a;
760 		} else
761 			laddr = &inp->in6p_laddr;	/* XXX */
762 		if (laddr == NULL) {
763 			if (error == 0)
764 				error = EADDRNOTAVAIL;
765 			goto release;
766 		}
767 		if (inp->inp_lport == 0 &&
768 		    (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
769 			/* Undo an address bind that may have occurred. */
770 			inp->in6p_laddr = in6addr_any;
771 			goto release;
772 		}
773 	} else {
774 		if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
775 			error = ENOTCONN;
776 			goto release;
777 		}
778 		if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
779 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
780 				/*
781 				 * XXX: this case would happen when the
782 				 * application sets the V6ONLY flag after
783 				 * connecting the foreign address.
784 				 * Such applications should be fixed,
785 				 * so we bark here.
786 				 */
787 				log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
788 				    "option was set for a connected socket\n");
789 				error = EINVAL;
790 				goto release;
791 			} else
792 				af = AF_INET;
793 		}
794 		laddr = &inp->in6p_laddr;
795 		faddr = &inp->in6p_faddr;
796 		fport = inp->inp_fport;
797 	}
798 
799 	if (af == AF_INET)
800 		hlen = sizeof(struct ip);
801 
802 	/*
803 	 * Calculate data length and get a mbuf
804 	 * for UDP and IP6 headers.
805 	 */
806 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
807 	if (m == NULL) {
808 		error = ENOBUFS;
809 		goto release;
810 	}
811 
812 	/*
813 	 * Stuff checksum and output datagram.
814 	 */
815 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
816 	udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
817 	udp6->uh_dport = fport;
818 	if (nxt == IPPROTO_UDPLITE) {
819 		struct udpcb *up;
820 
821 		up = intoudpcb(inp);
822 		cscov = up->u_txcslen;
823 		if (cscov >= plen)
824 			cscov = 0;
825 		udp6->uh_ulen = htons(cscov);
826 		/*
827 		 * For UDP-Lite, checksum coverage length of zero means
828 		 * the entire UDPLite packet is covered by the checksum.
829 		 */
830 		cscov_partial = (cscov == 0) ? 0 : 1;
831 	} else if (plen <= 0xffff)
832 		udp6->uh_ulen = htons((u_short)plen);
833 	else
834 		udp6->uh_ulen = 0;
835 	udp6->uh_sum = 0;
836 
837 	switch (af) {
838 	case AF_INET6:
839 		ip6 = mtod(m, struct ip6_hdr *);
840 		ip6->ip6_flow	= inp->inp_flow & IPV6_FLOWINFO_MASK;
841 		ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
842 		ip6->ip6_vfc	|= IPV6_VERSION;
843 		ip6->ip6_plen	= htons((u_short)plen);
844 		ip6->ip6_nxt	= nxt;
845 		ip6->ip6_hlim	= in6_selecthlim(inp, NULL);
846 		ip6->ip6_src	= *laddr;
847 		ip6->ip6_dst	= *faddr;
848 
849 		if (cscov_partial) {
850 			if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
851 			    sizeof(struct ip6_hdr), plen, cscov)) == 0)
852 				udp6->uh_sum = 0xffff;
853 		} else {
854 			udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
855 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
856 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
857 		}
858 
859 #ifdef	RSS
860 		{
861 			uint32_t hash_val, hash_type;
862 			uint8_t pr;
863 
864 			pr = inp->inp_socket->so_proto->pr_protocol;
865 			/*
866 			 * Calculate an appropriate RSS hash for UDP and
867 			 * UDP Lite.
868 			 *
869 			 * The called function will take care of figuring out
870 			 * whether a 2-tuple or 4-tuple hash is required based
871 			 * on the currently configured scheme.
872 			 *
873 			 * Later later on connected socket values should be
874 			 * cached in the inpcb and reused, rather than constantly
875 			 * re-calculating it.
876 			 *
877 			 * UDP Lite is a different protocol number and will
878 			 * likely end up being hashed as a 2-tuple until
879 			 * RSS / NICs grow UDP Lite protocol awareness.
880 			 */
881 			if (rss_proto_software_hash_v6(faddr, laddr, fport,
882 			    inp->inp_lport, pr, &hash_val, &hash_type) == 0) {
883 				m->m_pkthdr.flowid = hash_val;
884 				M_HASHTYPE_SET(m, hash_type);
885 			}
886 		}
887 #endif
888 		flags = 0;
889 #ifdef	RSS
890 		/*
891 		 * Don't override with the inp cached flowid.
892 		 *
893 		 * Until the whole UDP path is vetted, it may actually
894 		 * be incorrect.
895 		 */
896 		flags |= IP_NODEFAULTFLOWID;
897 #endif
898 
899 		UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
900 		UDPSTAT_INC(udps_opackets);
901 		error = ip6_output(m, optp, &inp->inp_route6, flags,
902 		    inp->in6p_moptions, NULL, inp);
903 		break;
904 	case AF_INET:
905 		error = EAFNOSUPPORT;
906 		goto release;
907 	}
908 	goto releaseopt;
909 
910 release:
911 	m_freem(m);
912 
913 releaseopt:
914 	if (control) {
915 		ip6_clearpktopts(&opt, -1);
916 		m_freem(control);
917 	}
918 	return (error);
919 }
920 
921 static void
922 udp6_abort(struct socket *so)
923 {
924 	struct inpcb *inp;
925 	struct inpcbinfo *pcbinfo;
926 
927 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
928 	inp = sotoinpcb(so);
929 	KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
930 
931 	INP_WLOCK(inp);
932 #ifdef INET
933 	if (inp->inp_vflag & INP_IPV4) {
934 		struct pr_usrreqs *pru;
935 		uint8_t nxt;
936 
937 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
938 		    IPPROTO_UDP : IPPROTO_UDPLITE;
939 		INP_WUNLOCK(inp);
940 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
941 		(*pru->pru_abort)(so);
942 		return;
943 	}
944 #endif
945 
946 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
947 		INP_HASH_WLOCK(pcbinfo);
948 		in6_pcbdisconnect(inp);
949 		inp->in6p_laddr = in6addr_any;
950 		INP_HASH_WUNLOCK(pcbinfo);
951 		soisdisconnected(so);
952 	}
953 	INP_WUNLOCK(inp);
954 }
955 
956 static int
957 udp6_attach(struct socket *so, int proto, struct thread *td)
958 {
959 	struct inpcb *inp;
960 	struct inpcbinfo *pcbinfo;
961 	int error;
962 
963 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
964 	inp = sotoinpcb(so);
965 	KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
966 
967 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
968 		error = soreserve(so, udp_sendspace, udp_recvspace);
969 		if (error)
970 			return (error);
971 	}
972 	INP_INFO_WLOCK(pcbinfo);
973 	error = in_pcballoc(so, pcbinfo);
974 	if (error) {
975 		INP_INFO_WUNLOCK(pcbinfo);
976 		return (error);
977 	}
978 	inp = (struct inpcb *)so->so_pcb;
979 	inp->inp_vflag |= INP_IPV6;
980 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
981 		inp->inp_vflag |= INP_IPV4;
982 	inp->in6p_hops = -1;	/* use kernel default */
983 	inp->in6p_cksum = -1;	/* just to be sure */
984 	/*
985 	 * XXX: ugly!!
986 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
987 	 * because the socket may be bound to an IPv6 wildcard address,
988 	 * which may match an IPv4-mapped IPv6 address.
989 	 */
990 	inp->inp_ip_ttl = V_ip_defttl;
991 
992 	error = udp_newudpcb(inp);
993 	if (error) {
994 		in_pcbdetach(inp);
995 		in_pcbfree(inp);
996 		INP_INFO_WUNLOCK(pcbinfo);
997 		return (error);
998 	}
999 	INP_WUNLOCK(inp);
1000 	INP_INFO_WUNLOCK(pcbinfo);
1001 	return (0);
1002 }
1003 
1004 static int
1005 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1006 {
1007 	struct inpcb *inp;
1008 	struct inpcbinfo *pcbinfo;
1009 	int error;
1010 
1011 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1012 	inp = sotoinpcb(so);
1013 	KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
1014 
1015 	INP_WLOCK(inp);
1016 	INP_HASH_WLOCK(pcbinfo);
1017 	inp->inp_vflag &= ~INP_IPV4;
1018 	inp->inp_vflag |= INP_IPV6;
1019 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1020 		struct sockaddr_in6 *sin6_p;
1021 
1022 		sin6_p = (struct sockaddr_in6 *)nam;
1023 
1024 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
1025 			inp->inp_vflag |= INP_IPV4;
1026 #ifdef INET
1027 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
1028 			struct sockaddr_in sin;
1029 
1030 			in6_sin6_2_sin(&sin, sin6_p);
1031 			inp->inp_vflag |= INP_IPV4;
1032 			inp->inp_vflag &= ~INP_IPV6;
1033 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
1034 			    td->td_ucred);
1035 			goto out;
1036 		}
1037 #endif
1038 	}
1039 
1040 	error = in6_pcbbind(inp, nam, td->td_ucred);
1041 #ifdef INET
1042 out:
1043 #endif
1044 	INP_HASH_WUNLOCK(pcbinfo);
1045 	INP_WUNLOCK(inp);
1046 	return (error);
1047 }
1048 
1049 static void
1050 udp6_close(struct socket *so)
1051 {
1052 	struct inpcb *inp;
1053 	struct inpcbinfo *pcbinfo;
1054 
1055 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1056 	inp = sotoinpcb(so);
1057 	KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
1058 
1059 	INP_WLOCK(inp);
1060 #ifdef INET
1061 	if (inp->inp_vflag & INP_IPV4) {
1062 		struct pr_usrreqs *pru;
1063 		uint8_t nxt;
1064 
1065 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1066 		    IPPROTO_UDP : IPPROTO_UDPLITE;
1067 		INP_WUNLOCK(inp);
1068 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1069 		(*pru->pru_disconnect)(so);
1070 		return;
1071 	}
1072 #endif
1073 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1074 		INP_HASH_WLOCK(pcbinfo);
1075 		in6_pcbdisconnect(inp);
1076 		inp->in6p_laddr = in6addr_any;
1077 		INP_HASH_WUNLOCK(pcbinfo);
1078 		soisdisconnected(so);
1079 	}
1080 	INP_WUNLOCK(inp);
1081 }
1082 
1083 static int
1084 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1085 {
1086 	struct inpcb *inp;
1087 	struct inpcbinfo *pcbinfo;
1088 	struct sockaddr_in6 *sin6;
1089 	int error;
1090 
1091 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1092 	inp = sotoinpcb(so);
1093 	sin6 = (struct sockaddr_in6 *)nam;
1094 	KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1095 
1096 	/*
1097 	 * XXXRW: Need to clarify locking of v4/v6 flags.
1098 	 */
1099 	INP_WLOCK(inp);
1100 #ifdef INET
1101 	if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1102 		struct sockaddr_in sin;
1103 
1104 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1105 			error = EINVAL;
1106 			goto out;
1107 		}
1108 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1109 			error = EISCONN;
1110 			goto out;
1111 		}
1112 		in6_sin6_2_sin(&sin, sin6);
1113 		inp->inp_vflag |= INP_IPV4;
1114 		inp->inp_vflag &= ~INP_IPV6;
1115 		error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1116 		if (error != 0)
1117 			goto out;
1118 		INP_HASH_WLOCK(pcbinfo);
1119 		error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1120 		    td->td_ucred);
1121 		INP_HASH_WUNLOCK(pcbinfo);
1122 		if (error == 0)
1123 			soisconnected(so);
1124 		goto out;
1125 	}
1126 #endif
1127 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1128 		error = EISCONN;
1129 		goto out;
1130 	}
1131 	inp->inp_vflag &= ~INP_IPV4;
1132 	inp->inp_vflag |= INP_IPV6;
1133 	error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1134 	if (error != 0)
1135 		goto out;
1136 	INP_HASH_WLOCK(pcbinfo);
1137 	error = in6_pcbconnect(inp, nam, td->td_ucred);
1138 	INP_HASH_WUNLOCK(pcbinfo);
1139 	if (error == 0)
1140 		soisconnected(so);
1141 out:
1142 	INP_WUNLOCK(inp);
1143 	return (error);
1144 }
1145 
1146 static void
1147 udp6_detach(struct socket *so)
1148 {
1149 	struct inpcb *inp;
1150 	struct inpcbinfo *pcbinfo;
1151 	struct udpcb *up;
1152 
1153 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1154 	inp = sotoinpcb(so);
1155 	KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1156 
1157 	INP_INFO_WLOCK(pcbinfo);
1158 	INP_WLOCK(inp);
1159 	up = intoudpcb(inp);
1160 	KASSERT(up != NULL, ("%s: up == NULL", __func__));
1161 	in_pcbdetach(inp);
1162 	in_pcbfree(inp);
1163 	INP_INFO_WUNLOCK(pcbinfo);
1164 	udp_discardcb(up);
1165 }
1166 
1167 static int
1168 udp6_disconnect(struct socket *so)
1169 {
1170 	struct inpcb *inp;
1171 	struct inpcbinfo *pcbinfo;
1172 	int error;
1173 
1174 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1175 	inp = sotoinpcb(so);
1176 	KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1177 
1178 	INP_WLOCK(inp);
1179 #ifdef INET
1180 	if (inp->inp_vflag & INP_IPV4) {
1181 		struct pr_usrreqs *pru;
1182 		uint8_t nxt;
1183 
1184 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1185 		    IPPROTO_UDP : IPPROTO_UDPLITE;
1186 		INP_WUNLOCK(inp);
1187 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1188 		(void)(*pru->pru_disconnect)(so);
1189 		return (0);
1190 	}
1191 #endif
1192 
1193 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1194 		error = ENOTCONN;
1195 		goto out;
1196 	}
1197 
1198 	INP_HASH_WLOCK(pcbinfo);
1199 	in6_pcbdisconnect(inp);
1200 	inp->in6p_laddr = in6addr_any;
1201 	INP_HASH_WUNLOCK(pcbinfo);
1202 	SOCK_LOCK(so);
1203 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1204 	SOCK_UNLOCK(so);
1205 out:
1206 	INP_WUNLOCK(inp);
1207 	return (0);
1208 }
1209 
1210 static int
1211 udp6_send(struct socket *so, int flags, struct mbuf *m,
1212     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1213 {
1214 	struct inpcb *inp;
1215 	struct inpcbinfo *pcbinfo;
1216 	int error = 0;
1217 
1218 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1219 	inp = sotoinpcb(so);
1220 	KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1221 
1222 	INP_WLOCK(inp);
1223 	if (addr) {
1224 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1225 			error = EINVAL;
1226 			goto bad;
1227 		}
1228 		if (addr->sa_family != AF_INET6) {
1229 			error = EAFNOSUPPORT;
1230 			goto bad;
1231 		}
1232 	}
1233 
1234 #ifdef INET
1235 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1236 		int hasv4addr;
1237 		struct sockaddr_in6 *sin6 = NULL;
1238 
1239 		if (addr == NULL)
1240 			hasv4addr = (inp->inp_vflag & INP_IPV4);
1241 		else {
1242 			sin6 = (struct sockaddr_in6 *)addr;
1243 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1244 			    ? 1 : 0;
1245 		}
1246 		if (hasv4addr) {
1247 			struct pr_usrreqs *pru;
1248 			uint8_t nxt;
1249 
1250 			nxt = (inp->inp_socket->so_proto->pr_protocol ==
1251 			    IPPROTO_UDP) ? IPPROTO_UDP : IPPROTO_UDPLITE;
1252 			/*
1253 			 * XXXRW: We release UDP-layer locks before calling
1254 			 * udp_send() in order to avoid recursion.  However,
1255 			 * this does mean there is a short window where inp's
1256 			 * fields are unstable.  Could this lead to a
1257 			 * potential race in which the factors causing us to
1258 			 * select the UDPv4 output routine are invalidated?
1259 			 */
1260 			INP_WUNLOCK(inp);
1261 			if (sin6)
1262 				in6_sin6_2_sin_in_sock(addr);
1263 			pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1264 			/* addr will just be freed in sendit(). */
1265 			return ((*pru->pru_send)(so, flags, m, addr, control,
1266 			    td));
1267 		}
1268 	}
1269 #endif
1270 #ifdef MAC
1271 	mac_inpcb_create_mbuf(inp, m);
1272 #endif
1273 	INP_HASH_WLOCK(pcbinfo);
1274 	error = udp6_output(inp, m, addr, control, td);
1275 	INP_HASH_WUNLOCK(pcbinfo);
1276 	INP_WUNLOCK(inp);
1277 	return (error);
1278 
1279 bad:
1280 	INP_WUNLOCK(inp);
1281 	m_freem(m);
1282 	return (error);
1283 }
1284 
1285 struct pr_usrreqs udp6_usrreqs = {
1286 	.pru_abort =		udp6_abort,
1287 	.pru_attach =		udp6_attach,
1288 	.pru_bind =		udp6_bind,
1289 	.pru_connect =		udp6_connect,
1290 	.pru_control =		in6_control,
1291 	.pru_detach =		udp6_detach,
1292 	.pru_disconnect =	udp6_disconnect,
1293 	.pru_peeraddr =		in6_mapped_peeraddr,
1294 	.pru_send =		udp6_send,
1295 	.pru_shutdown =		udp_shutdown,
1296 	.pru_sockaddr =		in6_mapped_sockaddr,
1297 	.pru_soreceive =	soreceive_dgram,
1298 	.pru_sosend =		sosend_dgram,
1299 	.pru_sosetlabel =	in_pcbsosetlabel,
1300 	.pru_close =		udp6_close
1301 };
1302