xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision b0b1dbdd)
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  * 3. 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 = NULL, *tmp_opts;
141 	struct udpcb *up;
142 
143 	INP_LOCK_ASSERT(inp);
144 
145 	/*
146 	 * Engage the tunneling protocol.
147 	 */
148 	up = intoudpcb(inp);
149 	if (up->u_tun_func != NULL) {
150 		in_pcbref(inp);
151 		INP_RUNLOCK(inp);
152 		(*up->u_tun_func)(n, off, inp, (struct sockaddr *)&fromsa[0],
153 		    up->u_tun_ctx);
154 		INP_RLOCK(inp);
155 		return (in_pcbrele_rlocked(inp));
156 	}
157 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
158 	/* Check AH/ESP integrity. */
159 	if (IPSEC_ENABLED(ipv6)) {
160 		if (IPSEC_CHECK_POLICY(ipv6, n, inp) != 0) {
161 			m_freem(n);
162 			return (0);
163 		}
164 	}
165 #endif /* IPSEC */
166 #ifdef MAC
167 	if (mac_inpcb_check_deliver(inp, n) != 0) {
168 		m_freem(n);
169 		return (0);
170 	}
171 #endif
172 	opts = NULL;
173 	if (inp->inp_flags & INP_CONTROLOPTS ||
174 	    inp->inp_socket->so_options & SO_TIMESTAMP)
175 		ip6_savecontrol(inp, n, &opts);
176 	if ((inp->inp_vflag & INP_IPV6) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
177 		tmp_opts = sbcreatecontrol((caddr_t)&fromsa[1],
178                         sizeof(struct sockaddr_in6), IPV6_ORIGDSTADDR, IPPROTO_IPV6);
179                 if (tmp_opts) {
180                         if (opts) {
181                                 tmp_opts->m_next = opts;
182                                 opts = tmp_opts;
183                         } else
184                                 opts = tmp_opts;
185                 }
186 
187 	}
188 	m_adj(n, off + sizeof(struct udphdr));
189 
190 	so = inp->inp_socket;
191 	SOCKBUF_LOCK(&so->so_rcv);
192 	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&fromsa[0], n,
193 	    opts) == 0) {
194 		SOCKBUF_UNLOCK(&so->so_rcv);
195 		m_freem(n);
196 		if (opts)
197 			m_freem(opts);
198 		UDPSTAT_INC(udps_fullsock);
199 	} else
200 		sorwakeup_locked(so);
201 	return (0);
202 }
203 
204 int
205 udp6_input(struct mbuf **mp, int *offp, int proto)
206 {
207 	struct mbuf *m = *mp;
208 	struct ifnet *ifp;
209 	struct ip6_hdr *ip6;
210 	struct udphdr *uh;
211 	struct inpcb *inp;
212 	struct inpcbinfo *pcbinfo;
213 	struct udpcb *up;
214 	int off = *offp;
215 	int cscov_partial;
216 	int plen, ulen;
217 	struct sockaddr_in6 fromsa[2];
218 	struct m_tag *fwd_tag;
219 	uint16_t uh_sum;
220 	uint8_t nxt;
221 
222 	ifp = m->m_pkthdr.rcvif;
223 	ip6 = mtod(m, struct ip6_hdr *);
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 #endif
234 
235 	UDPSTAT_INC(udps_ipackets);
236 
237 	/*
238 	 * Destination port of 0 is illegal, based on RFC768.
239 	 */
240 	if (uh->uh_dport == 0)
241 		goto badunlocked;
242 
243 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
244 	ulen = ntohs((u_short)uh->uh_ulen);
245 
246 	nxt = proto;
247 	cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
248 	if (nxt == IPPROTO_UDPLITE) {
249 		/* Zero means checksum over the complete packet. */
250 		if (ulen == 0)
251 			ulen = plen;
252 		if (ulen == plen)
253 			cscov_partial = 0;
254 		if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
255 			/* XXX: What is the right UDPLite MIB counter? */
256 			goto badunlocked;
257 		}
258 		if (uh->uh_sum == 0) {
259 			/* XXX: What is the right UDPLite MIB counter? */
260 			goto badunlocked;
261 		}
262 	} else {
263 		if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
264 			UDPSTAT_INC(udps_badlen);
265 			goto badunlocked;
266 		}
267 		if (uh->uh_sum == 0) {
268 			UDPSTAT_INC(udps_nosum);
269 			goto badunlocked;
270 		}
271 	}
272 
273 	if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
274 	    !cscov_partial) {
275 		if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
276 			uh_sum = m->m_pkthdr.csum_data;
277 		else
278 			uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
279 			    m->m_pkthdr.csum_data);
280 		uh_sum ^= 0xffff;
281 	} else
282 		uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
283 
284 	if (uh_sum != 0) {
285 		UDPSTAT_INC(udps_badsum);
286 		goto badunlocked;
287 	}
288 
289 	/*
290 	 * Construct sockaddr format source address.
291 	 */
292 	init_sin6(&fromsa[0], m, 0);
293 	fromsa[0].sin6_port = uh->uh_sport;
294 	init_sin6(&fromsa[1], m, 1);
295 	fromsa[1].sin6_port = uh->uh_dport;
296 
297 	pcbinfo = udp_get_inpcbinfo(nxt);
298 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
299 		struct inpcb *last;
300 		struct inpcbhead *pcblist;
301 		struct ip6_moptions *imo;
302 
303 		INP_INFO_RLOCK(pcbinfo);
304 		/*
305 		 * In the event that laddr should be set to the link-local
306 		 * address (this happens in RIPng), the multicast address
307 		 * specified in the received packet will not match laddr.  To
308 		 * handle this situation, matching is relaxed if the
309 		 * receiving interface is the same as one specified in the
310 		 * socket and if the destination multicast address matches
311 		 * one of the multicast groups specified in the socket.
312 		 */
313 
314 		/*
315 		 * KAME note: traditionally we dropped udpiphdr from mbuf
316 		 * here.  We need udphdr for IPsec processing so we do that
317 		 * later.
318 		 */
319 		pcblist = udp_get_pcblist(nxt);
320 		last = NULL;
321 		LIST_FOREACH(inp, pcblist, inp_list) {
322 			if ((inp->inp_vflag & INP_IPV6) == 0)
323 				continue;
324 			if (inp->inp_lport != uh->uh_dport)
325 				continue;
326 			if (inp->inp_fport != 0 &&
327 			    inp->inp_fport != uh->uh_sport)
328 				continue;
329 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
330 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
331 							&ip6->ip6_dst))
332 					continue;
333 			}
334 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
335 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
336 							&ip6->ip6_src) ||
337 				    inp->inp_fport != uh->uh_sport)
338 					continue;
339 			}
340 
341 			/*
342 			 * XXXRW: Because we weren't holding either the inpcb
343 			 * or the hash lock when we checked for a match
344 			 * before, we should probably recheck now that the
345 			 * inpcb lock is (supposed to be) held.
346 			 */
347 
348 			/*
349 			 * Handle socket delivery policy for any-source
350 			 * and source-specific multicast. [RFC3678]
351 			 */
352 			imo = inp->in6p_moptions;
353 			if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
354 				struct sockaddr_in6	 mcaddr;
355 				int			 blocked;
356 
357 				INP_RLOCK(inp);
358 
359 				bzero(&mcaddr, sizeof(struct sockaddr_in6));
360 				mcaddr.sin6_len = sizeof(struct sockaddr_in6);
361 				mcaddr.sin6_family = AF_INET6;
362 				mcaddr.sin6_addr = ip6->ip6_dst;
363 
364 				blocked = im6o_mc_filter(imo, ifp,
365 					(struct sockaddr *)&mcaddr,
366 					(struct sockaddr *)&fromsa[0]);
367 				if (blocked != MCAST_PASS) {
368 					if (blocked == MCAST_NOTGMEMBER)
369 						IP6STAT_INC(ip6s_notmember);
370 					if (blocked == MCAST_NOTSMEMBER ||
371 					    blocked == MCAST_MUTED)
372 						UDPSTAT_INC(udps_filtermcast);
373 					INP_RUNLOCK(inp); /* XXX */
374 					continue;
375 				}
376 
377 				INP_RUNLOCK(inp);
378 			}
379 			if (last != NULL) {
380 				struct mbuf *n;
381 
382 				if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) !=
383 				    NULL) {
384 					INP_RLOCK(last);
385 					UDP_PROBE(receive, NULL, last, ip6,
386 					    last, uh);
387 					if (udp6_append(last, n, off, fromsa))
388 						goto inp_lost;
389 					INP_RUNLOCK(last);
390 				}
391 			}
392 			last = inp;
393 			/*
394 			 * Don't look for additional matches if this one does
395 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
396 			 * socket options set.  This heuristic avoids
397 			 * searching through all pcbs in the common case of a
398 			 * non-shared port.  It assumes that an application
399 			 * will never clear these options after setting them.
400 			 */
401 			if ((last->inp_socket->so_options &
402 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
403 				break;
404 		}
405 
406 		if (last == NULL) {
407 			/*
408 			 * No matching pcb found; discard datagram.  (No need
409 			 * to send an ICMP Port Unreachable for a broadcast
410 			 * or multicast datgram.)
411 			 */
412 			UDPSTAT_INC(udps_noport);
413 			UDPSTAT_INC(udps_noportmcast);
414 			goto badheadlocked;
415 		}
416 		INP_RLOCK(last);
417 		INP_INFO_RUNLOCK(pcbinfo);
418 		UDP_PROBE(receive, NULL, last, ip6, last, uh);
419 		if (udp6_append(last, m, off, fromsa) == 0)
420 			INP_RUNLOCK(last);
421 	inp_lost:
422 		return (IPPROTO_DONE);
423 	}
424 	/*
425 	 * Locate pcb for datagram.
426 	 */
427 
428 	/*
429 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
430 	 */
431 	if ((m->m_flags & M_IP6_NEXTHOP) &&
432 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
433 		struct sockaddr_in6 *next_hop6;
434 
435 		next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
436 
437 		/*
438 		 * Transparently forwarded. Pretend to be the destination.
439 		 * Already got one like this?
440 		 */
441 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
442 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
443 		    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
444 		if (!inp) {
445 			/*
446 			 * It's new.  Try to find the ambushing socket.
447 			 * Because we've rewritten the destination address,
448 			 * any hardware-generated hash is ignored.
449 			 */
450 			inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
451 			    uh->uh_sport, &next_hop6->sin6_addr,
452 			    next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
453 			    uh->uh_dport, INPLOOKUP_WILDCARD |
454 			    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
455 		}
456 		/* Remove the tag from the packet. We don't need it anymore. */
457 		m_tag_delete(m, fwd_tag);
458 		m->m_flags &= ~M_IP6_NEXTHOP;
459 	} else
460 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
461 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
462 		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
463 		    m->m_pkthdr.rcvif, m);
464 	if (inp == NULL) {
465 		if (udp_log_in_vain) {
466 			char ip6bufs[INET6_ADDRSTRLEN];
467 			char ip6bufd[INET6_ADDRSTRLEN];
468 
469 			log(LOG_INFO,
470 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
471 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
472 			    ntohs(uh->uh_dport),
473 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
474 			    ntohs(uh->uh_sport));
475 		}
476 		UDPSTAT_INC(udps_noport);
477 		if (m->m_flags & M_MCAST) {
478 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
479 			UDPSTAT_INC(udps_noportmcast);
480 			goto badunlocked;
481 		}
482 		if (V_udp_blackhole)
483 			goto badunlocked;
484 		if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
485 			goto badunlocked;
486 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
487 		return (IPPROTO_DONE);
488 	}
489 	INP_RLOCK_ASSERT(inp);
490 	up = intoudpcb(inp);
491 	if (cscov_partial) {
492 		if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
493 			INP_RUNLOCK(inp);
494 			m_freem(m);
495 			return (IPPROTO_DONE);
496 		}
497 	}
498 	UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
499 	if (udp6_append(inp, m, off, fromsa) == 0)
500 		INP_RUNLOCK(inp);
501 	return (IPPROTO_DONE);
502 
503 badheadlocked:
504 	INP_INFO_RUNLOCK(pcbinfo);
505 badunlocked:
506 	if (m)
507 		m_freem(m);
508 	return (IPPROTO_DONE);
509 }
510 
511 static void
512 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
513     struct inpcbinfo *pcbinfo)
514 {
515 	struct udphdr uh;
516 	struct ip6_hdr *ip6;
517 	struct mbuf *m;
518 	int off = 0;
519 	struct ip6ctlparam *ip6cp = NULL;
520 	const struct sockaddr_in6 *sa6_src = NULL;
521 	void *cmdarg;
522 	struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
523 	struct udp_portonly {
524 		u_int16_t uh_sport;
525 		u_int16_t uh_dport;
526 	} *uhp;
527 
528 	if (sa->sa_family != AF_INET6 ||
529 	    sa->sa_len != sizeof(struct sockaddr_in6))
530 		return;
531 
532 	if ((unsigned)cmd >= PRC_NCMDS)
533 		return;
534 	if (PRC_IS_REDIRECT(cmd))
535 		notify = in6_rtchange, d = NULL;
536 	else if (cmd == PRC_HOSTDEAD)
537 		d = NULL;
538 	else if (inet6ctlerrmap[cmd] == 0)
539 		return;
540 
541 	/* if the parameter is from icmp6, decode it. */
542 	if (d != NULL) {
543 		ip6cp = (struct ip6ctlparam *)d;
544 		m = ip6cp->ip6c_m;
545 		ip6 = ip6cp->ip6c_ip6;
546 		off = ip6cp->ip6c_off;
547 		cmdarg = ip6cp->ip6c_cmdarg;
548 		sa6_src = ip6cp->ip6c_src;
549 	} else {
550 		m = NULL;
551 		ip6 = NULL;
552 		cmdarg = NULL;
553 		sa6_src = &sa6_any;
554 	}
555 
556 	if (ip6) {
557 		/*
558 		 * XXX: We assume that when IPV6 is non NULL,
559 		 * M and OFF are valid.
560 		 */
561 
562 		/* Check if we can safely examine src and dst ports. */
563 		if (m->m_pkthdr.len < off + sizeof(*uhp))
564 			return;
565 
566 		bzero(&uh, sizeof(uh));
567 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
568 
569 		if (!PRC_IS_REDIRECT(cmd)) {
570 			/* Check to see if its tunneled */
571 			struct inpcb *inp;
572 			inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_dst,
573 			    uh.uh_dport, &ip6->ip6_src, uh.uh_sport,
574 			    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
575 			    m->m_pkthdr.rcvif, m);
576 			if (inp != NULL) {
577 				struct udpcb *up;
578 
579 				up = intoudpcb(inp);
580 				if (up->u_icmp_func) {
581 					/* Yes it is. */
582 					INP_RUNLOCK(inp);
583 					(*up->u_icmp_func)(cmd, (struct sockaddr *)ip6cp->ip6c_src,
584 					      d, up->u_tun_ctx);
585 					return;
586 				} else {
587 					/* Can't find it. */
588 					INP_RUNLOCK(inp);
589 				}
590 			}
591 		}
592 		(void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
593 		    (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
594 		    cmdarg, notify);
595 	} else
596 		(void)in6_pcbnotify(pcbinfo, sa, 0,
597 		    (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
598 }
599 
600 void
601 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
602 {
603 
604 	return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
605 }
606 
607 void
608 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
609 {
610 
611 	return (udp6_common_ctlinput(cmd, sa, d, &V_ulitecbinfo));
612 }
613 
614 static int
615 udp6_getcred(SYSCTL_HANDLER_ARGS)
616 {
617 	struct xucred xuc;
618 	struct sockaddr_in6 addrs[2];
619 	struct inpcb *inp;
620 	int error;
621 
622 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
623 	if (error)
624 		return (error);
625 
626 	if (req->newlen != sizeof(addrs))
627 		return (EINVAL);
628 	if (req->oldlen != sizeof(struct xucred))
629 		return (EINVAL);
630 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
631 	if (error)
632 		return (error);
633 	if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
634 	    (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
635 		return (error);
636 	}
637 	inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
638 	    addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
639 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
640 	if (inp != NULL) {
641 		INP_RLOCK_ASSERT(inp);
642 		if (inp->inp_socket == NULL)
643 			error = ENOENT;
644 		if (error == 0)
645 			error = cr_canseesocket(req->td->td_ucred,
646 			    inp->inp_socket);
647 		if (error == 0)
648 			cru2x(inp->inp_cred, &xuc);
649 		INP_RUNLOCK(inp);
650 	} else
651 		error = ENOENT;
652 	if (error == 0)
653 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
654 	return (error);
655 }
656 
657 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
658     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
659 
660 static int
661 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
662     struct mbuf *control, struct thread *td)
663 {
664 	u_int32_t ulen = m->m_pkthdr.len;
665 	u_int32_t plen = sizeof(struct udphdr) + ulen;
666 	struct ip6_hdr *ip6;
667 	struct udphdr *udp6;
668 	struct in6_addr *laddr, *faddr, in6a;
669 	struct sockaddr_in6 *sin6 = NULL;
670 	int cscov_partial = 0;
671 	int scope_ambiguous = 0;
672 	u_short fport;
673 	int error = 0;
674 	uint8_t nxt;
675 	uint16_t cscov = 0;
676 	struct ip6_pktopts *optp, opt;
677 	int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
678 	int flags;
679 	struct sockaddr_in6 tmp;
680 
681 	INP_WLOCK_ASSERT(inp);
682 	INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
683 
684 	if (addr6) {
685 		/* addr6 has been validated in udp6_send(). */
686 		sin6 = (struct sockaddr_in6 *)addr6;
687 
688 		/* protect *sin6 from overwrites */
689 		tmp = *sin6;
690 		sin6 = &tmp;
691 
692 		/*
693 		 * Application should provide a proper zone ID or the use of
694 		 * default zone IDs should be enabled.  Unfortunately, some
695 		 * applications do not behave as it should, so we need a
696 		 * workaround.  Even if an appropriate ID is not determined,
697 		 * we'll see if we can determine the outgoing interface.  If we
698 		 * can, determine the zone ID based on the interface below.
699 		 */
700 		if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
701 			scope_ambiguous = 1;
702 		if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
703 			return (error);
704 	}
705 
706 	nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
707 	    IPPROTO_UDP : IPPROTO_UDPLITE;
708 	if (control) {
709 		if ((error = ip6_setpktopts(control, &opt,
710 		    inp->in6p_outputopts, td->td_ucred, nxt)) != 0)
711 			goto release;
712 		optp = &opt;
713 	} else
714 		optp = inp->in6p_outputopts;
715 
716 	if (sin6) {
717 		faddr = &sin6->sin6_addr;
718 
719 		/*
720 		 * Since we saw no essential reason for calling in_pcbconnect,
721 		 * we get rid of such kind of logic, and call in6_selectsrc
722 		 * and in6_pcbsetport in order to fill in the local address
723 		 * and the local port.
724 		 */
725 		if (sin6->sin6_port == 0) {
726 			error = EADDRNOTAVAIL;
727 			goto release;
728 		}
729 
730 		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
731 			/* how about ::ffff:0.0.0.0 case? */
732 			error = EISCONN;
733 			goto release;
734 		}
735 
736 		fport = sin6->sin6_port; /* allow 0 port */
737 
738 		if (IN6_IS_ADDR_V4MAPPED(faddr)) {
739 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
740 				/*
741 				 * I believe we should explicitly discard the
742 				 * packet when mapped addresses are disabled,
743 				 * rather than send the packet as an IPv6 one.
744 				 * If we chose the latter approach, the packet
745 				 * might be sent out on the wire based on the
746 				 * default route, the situation which we'd
747 				 * probably want to avoid.
748 				 * (20010421 jinmei@kame.net)
749 				 */
750 				error = EINVAL;
751 				goto release;
752 			}
753 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
754 			    !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
755 				/*
756 				 * when remote addr is an IPv4-mapped address,
757 				 * local addr should not be an IPv6 address,
758 				 * since you cannot determine how to map IPv6
759 				 * source address to IPv4.
760 				 */
761 				error = EINVAL;
762 				goto release;
763 			}
764 
765 			af = AF_INET;
766 		}
767 
768 		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
769 			error = in6_selectsrc_socket(sin6, optp, inp,
770 			    td->td_ucred, scope_ambiguous, &in6a, NULL);
771 			if (error)
772 				goto release;
773 			laddr = &in6a;
774 		} else
775 			laddr = &inp->in6p_laddr;	/* XXX */
776 		if (laddr == NULL) {
777 			if (error == 0)
778 				error = EADDRNOTAVAIL;
779 			goto release;
780 		}
781 		if (inp->inp_lport == 0 &&
782 		    (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
783 			/* Undo an address bind that may have occurred. */
784 			inp->in6p_laddr = in6addr_any;
785 			goto release;
786 		}
787 	} else {
788 		if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
789 			error = ENOTCONN;
790 			goto release;
791 		}
792 		if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
793 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
794 				/*
795 				 * XXX: this case would happen when the
796 				 * application sets the V6ONLY flag after
797 				 * connecting the foreign address.
798 				 * Such applications should be fixed,
799 				 * so we bark here.
800 				 */
801 				log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
802 				    "option was set for a connected socket\n");
803 				error = EINVAL;
804 				goto release;
805 			} else
806 				af = AF_INET;
807 		}
808 		laddr = &inp->in6p_laddr;
809 		faddr = &inp->in6p_faddr;
810 		fport = inp->inp_fport;
811 	}
812 
813 	if (af == AF_INET)
814 		hlen = sizeof(struct ip);
815 
816 	/*
817 	 * Calculate data length and get a mbuf
818 	 * for UDP and IP6 headers.
819 	 */
820 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
821 	if (m == NULL) {
822 		error = ENOBUFS;
823 		goto release;
824 	}
825 
826 	/*
827 	 * Stuff checksum and output datagram.
828 	 */
829 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
830 	udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
831 	udp6->uh_dport = fport;
832 	if (nxt == IPPROTO_UDPLITE) {
833 		struct udpcb *up;
834 
835 		up = intoudpcb(inp);
836 		cscov = up->u_txcslen;
837 		if (cscov >= plen)
838 			cscov = 0;
839 		udp6->uh_ulen = htons(cscov);
840 		/*
841 		 * For UDP-Lite, checksum coverage length of zero means
842 		 * the entire UDPLite packet is covered by the checksum.
843 		 */
844 		cscov_partial = (cscov == 0) ? 0 : 1;
845 	} else if (plen <= 0xffff)
846 		udp6->uh_ulen = htons((u_short)plen);
847 	else
848 		udp6->uh_ulen = 0;
849 	udp6->uh_sum = 0;
850 
851 	switch (af) {
852 	case AF_INET6:
853 		ip6 = mtod(m, struct ip6_hdr *);
854 		ip6->ip6_flow	= inp->inp_flow & IPV6_FLOWINFO_MASK;
855 		ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
856 		ip6->ip6_vfc	|= IPV6_VERSION;
857 		ip6->ip6_plen	= htons((u_short)plen);
858 		ip6->ip6_nxt	= nxt;
859 		ip6->ip6_hlim	= in6_selecthlim(inp, NULL);
860 		ip6->ip6_src	= *laddr;
861 		ip6->ip6_dst	= *faddr;
862 
863 		if (cscov_partial) {
864 			if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
865 			    sizeof(struct ip6_hdr), plen, cscov)) == 0)
866 				udp6->uh_sum = 0xffff;
867 		} else {
868 			udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
869 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
870 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
871 		}
872 
873 #ifdef	RSS
874 		{
875 			uint32_t hash_val, hash_type;
876 			uint8_t pr;
877 
878 			pr = inp->inp_socket->so_proto->pr_protocol;
879 			/*
880 			 * Calculate an appropriate RSS hash for UDP and
881 			 * UDP Lite.
882 			 *
883 			 * The called function will take care of figuring out
884 			 * whether a 2-tuple or 4-tuple hash is required based
885 			 * on the currently configured scheme.
886 			 *
887 			 * Later later on connected socket values should be
888 			 * cached in the inpcb and reused, rather than constantly
889 			 * re-calculating it.
890 			 *
891 			 * UDP Lite is a different protocol number and will
892 			 * likely end up being hashed as a 2-tuple until
893 			 * RSS / NICs grow UDP Lite protocol awareness.
894 			 */
895 			if (rss_proto_software_hash_v6(faddr, laddr, fport,
896 			    inp->inp_lport, pr, &hash_val, &hash_type) == 0) {
897 				m->m_pkthdr.flowid = hash_val;
898 				M_HASHTYPE_SET(m, hash_type);
899 			}
900 		}
901 #endif
902 		flags = 0;
903 #ifdef	RSS
904 		/*
905 		 * Don't override with the inp cached flowid.
906 		 *
907 		 * Until the whole UDP path is vetted, it may actually
908 		 * be incorrect.
909 		 */
910 		flags |= IP_NODEFAULTFLOWID;
911 #endif
912 
913 		UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
914 		UDPSTAT_INC(udps_opackets);
915 		error = ip6_output(m, optp, &inp->inp_route6, flags,
916 		    inp->in6p_moptions, NULL, inp);
917 		break;
918 	case AF_INET:
919 		error = EAFNOSUPPORT;
920 		goto release;
921 	}
922 	goto releaseopt;
923 
924 release:
925 	m_freem(m);
926 
927 releaseopt:
928 	if (control) {
929 		ip6_clearpktopts(&opt, -1);
930 		m_freem(control);
931 	}
932 	return (error);
933 }
934 
935 static void
936 udp6_abort(struct socket *so)
937 {
938 	struct inpcb *inp;
939 	struct inpcbinfo *pcbinfo;
940 
941 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
942 	inp = sotoinpcb(so);
943 	KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
944 
945 	INP_WLOCK(inp);
946 #ifdef INET
947 	if (inp->inp_vflag & INP_IPV4) {
948 		struct pr_usrreqs *pru;
949 		uint8_t nxt;
950 
951 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
952 		    IPPROTO_UDP : IPPROTO_UDPLITE;
953 		INP_WUNLOCK(inp);
954 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
955 		(*pru->pru_abort)(so);
956 		return;
957 	}
958 #endif
959 
960 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
961 		INP_HASH_WLOCK(pcbinfo);
962 		in6_pcbdisconnect(inp);
963 		inp->in6p_laddr = in6addr_any;
964 		INP_HASH_WUNLOCK(pcbinfo);
965 		soisdisconnected(so);
966 	}
967 	INP_WUNLOCK(inp);
968 }
969 
970 static int
971 udp6_attach(struct socket *so, int proto, struct thread *td)
972 {
973 	struct inpcb *inp;
974 	struct inpcbinfo *pcbinfo;
975 	int error;
976 
977 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
978 	inp = sotoinpcb(so);
979 	KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
980 
981 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
982 		error = soreserve(so, udp_sendspace, udp_recvspace);
983 		if (error)
984 			return (error);
985 	}
986 	INP_INFO_WLOCK(pcbinfo);
987 	error = in_pcballoc(so, pcbinfo);
988 	if (error) {
989 		INP_INFO_WUNLOCK(pcbinfo);
990 		return (error);
991 	}
992 	inp = (struct inpcb *)so->so_pcb;
993 	inp->inp_vflag |= INP_IPV6;
994 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
995 		inp->inp_vflag |= INP_IPV4;
996 	inp->in6p_hops = -1;	/* use kernel default */
997 	inp->in6p_cksum = -1;	/* just to be sure */
998 	/*
999 	 * XXX: ugly!!
1000 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
1001 	 * because the socket may be bound to an IPv6 wildcard address,
1002 	 * which may match an IPv4-mapped IPv6 address.
1003 	 */
1004 	inp->inp_ip_ttl = V_ip_defttl;
1005 
1006 	error = udp_newudpcb(inp);
1007 	if (error) {
1008 		in_pcbdetach(inp);
1009 		in_pcbfree(inp);
1010 		INP_INFO_WUNLOCK(pcbinfo);
1011 		return (error);
1012 	}
1013 	INP_WUNLOCK(inp);
1014 	INP_INFO_WUNLOCK(pcbinfo);
1015 	return (0);
1016 }
1017 
1018 static int
1019 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1020 {
1021 	struct inpcb *inp;
1022 	struct inpcbinfo *pcbinfo;
1023 	int error;
1024 
1025 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1026 	inp = sotoinpcb(so);
1027 	KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
1028 
1029 	INP_WLOCK(inp);
1030 	INP_HASH_WLOCK(pcbinfo);
1031 	inp->inp_vflag &= ~INP_IPV4;
1032 	inp->inp_vflag |= INP_IPV6;
1033 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1034 		struct sockaddr_in6 *sin6_p;
1035 
1036 		sin6_p = (struct sockaddr_in6 *)nam;
1037 
1038 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
1039 			inp->inp_vflag |= INP_IPV4;
1040 #ifdef INET
1041 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
1042 			struct sockaddr_in sin;
1043 
1044 			in6_sin6_2_sin(&sin, sin6_p);
1045 			inp->inp_vflag |= INP_IPV4;
1046 			inp->inp_vflag &= ~INP_IPV6;
1047 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
1048 			    td->td_ucred);
1049 			goto out;
1050 		}
1051 #endif
1052 	}
1053 
1054 	error = in6_pcbbind(inp, nam, td->td_ucred);
1055 #ifdef INET
1056 out:
1057 #endif
1058 	INP_HASH_WUNLOCK(pcbinfo);
1059 	INP_WUNLOCK(inp);
1060 	return (error);
1061 }
1062 
1063 static void
1064 udp6_close(struct socket *so)
1065 {
1066 	struct inpcb *inp;
1067 	struct inpcbinfo *pcbinfo;
1068 
1069 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1070 	inp = sotoinpcb(so);
1071 	KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
1072 
1073 	INP_WLOCK(inp);
1074 #ifdef INET
1075 	if (inp->inp_vflag & INP_IPV4) {
1076 		struct pr_usrreqs *pru;
1077 		uint8_t nxt;
1078 
1079 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1080 		    IPPROTO_UDP : IPPROTO_UDPLITE;
1081 		INP_WUNLOCK(inp);
1082 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1083 		(*pru->pru_disconnect)(so);
1084 		return;
1085 	}
1086 #endif
1087 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1088 		INP_HASH_WLOCK(pcbinfo);
1089 		in6_pcbdisconnect(inp);
1090 		inp->in6p_laddr = in6addr_any;
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 inpcb *inp;
1101 	struct inpcbinfo *pcbinfo;
1102 	struct sockaddr_in6 *sin6;
1103 	int error;
1104 
1105 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1106 	inp = sotoinpcb(so);
1107 	sin6 = (struct sockaddr_in6 *)nam;
1108 	KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1109 
1110 	/*
1111 	 * XXXRW: Need to clarify locking of v4/v6 flags.
1112 	 */
1113 	INP_WLOCK(inp);
1114 #ifdef INET
1115 	if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1116 		struct sockaddr_in sin;
1117 
1118 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1119 			error = EINVAL;
1120 			goto out;
1121 		}
1122 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1123 			error = EISCONN;
1124 			goto out;
1125 		}
1126 		in6_sin6_2_sin(&sin, sin6);
1127 		inp->inp_vflag |= INP_IPV4;
1128 		inp->inp_vflag &= ~INP_IPV6;
1129 		error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1130 		if (error != 0)
1131 			goto out;
1132 		INP_HASH_WLOCK(pcbinfo);
1133 		error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1134 		    td->td_ucred);
1135 		INP_HASH_WUNLOCK(pcbinfo);
1136 		if (error == 0)
1137 			soisconnected(so);
1138 		goto out;
1139 	}
1140 #endif
1141 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1142 		error = EISCONN;
1143 		goto out;
1144 	}
1145 	inp->inp_vflag &= ~INP_IPV4;
1146 	inp->inp_vflag |= INP_IPV6;
1147 	error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1148 	if (error != 0)
1149 		goto out;
1150 	INP_HASH_WLOCK(pcbinfo);
1151 	error = in6_pcbconnect(inp, nam, td->td_ucred);
1152 	INP_HASH_WUNLOCK(pcbinfo);
1153 	if (error == 0)
1154 		soisconnected(so);
1155 out:
1156 	INP_WUNLOCK(inp);
1157 	return (error);
1158 }
1159 
1160 static void
1161 udp6_detach(struct socket *so)
1162 {
1163 	struct inpcb *inp;
1164 	struct inpcbinfo *pcbinfo;
1165 	struct udpcb *up;
1166 
1167 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1168 	inp = sotoinpcb(so);
1169 	KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1170 
1171 	INP_INFO_WLOCK(pcbinfo);
1172 	INP_WLOCK(inp);
1173 	up = intoudpcb(inp);
1174 	KASSERT(up != NULL, ("%s: up == NULL", __func__));
1175 	in_pcbdetach(inp);
1176 	in_pcbfree(inp);
1177 	INP_INFO_WUNLOCK(pcbinfo);
1178 	udp_discardcb(up);
1179 }
1180 
1181 static int
1182 udp6_disconnect(struct socket *so)
1183 {
1184 	struct inpcb *inp;
1185 	struct inpcbinfo *pcbinfo;
1186 	int error;
1187 
1188 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1189 	inp = sotoinpcb(so);
1190 	KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1191 
1192 	INP_WLOCK(inp);
1193 #ifdef INET
1194 	if (inp->inp_vflag & INP_IPV4) {
1195 		struct pr_usrreqs *pru;
1196 		uint8_t nxt;
1197 
1198 		nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1199 		    IPPROTO_UDP : IPPROTO_UDPLITE;
1200 		INP_WUNLOCK(inp);
1201 		pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1202 		(void)(*pru->pru_disconnect)(so);
1203 		return (0);
1204 	}
1205 #endif
1206 
1207 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1208 		error = ENOTCONN;
1209 		goto out;
1210 	}
1211 
1212 	INP_HASH_WLOCK(pcbinfo);
1213 	in6_pcbdisconnect(inp);
1214 	inp->in6p_laddr = in6addr_any;
1215 	INP_HASH_WUNLOCK(pcbinfo);
1216 	SOCK_LOCK(so);
1217 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1218 	SOCK_UNLOCK(so);
1219 out:
1220 	INP_WUNLOCK(inp);
1221 	return (0);
1222 }
1223 
1224 static int
1225 udp6_send(struct socket *so, int flags, struct mbuf *m,
1226     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1227 {
1228 	struct inpcb *inp;
1229 	struct inpcbinfo *pcbinfo;
1230 	int error = 0;
1231 
1232 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1233 	inp = sotoinpcb(so);
1234 	KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1235 
1236 	INP_WLOCK(inp);
1237 	if (addr) {
1238 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1239 			error = EINVAL;
1240 			goto bad;
1241 		}
1242 		if (addr->sa_family != AF_INET6) {
1243 			error = EAFNOSUPPORT;
1244 			goto bad;
1245 		}
1246 	}
1247 
1248 #ifdef INET
1249 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1250 		int hasv4addr;
1251 		struct sockaddr_in6 *sin6 = NULL;
1252 
1253 		if (addr == NULL)
1254 			hasv4addr = (inp->inp_vflag & INP_IPV4);
1255 		else {
1256 			sin6 = (struct sockaddr_in6 *)addr;
1257 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1258 			    ? 1 : 0;
1259 		}
1260 		if (hasv4addr) {
1261 			struct pr_usrreqs *pru;
1262 			uint8_t nxt;
1263 
1264 			nxt = (inp->inp_socket->so_proto->pr_protocol ==
1265 			    IPPROTO_UDP) ? IPPROTO_UDP : IPPROTO_UDPLITE;
1266 			/*
1267 			 * XXXRW: We release UDP-layer locks before calling
1268 			 * udp_send() in order to avoid recursion.  However,
1269 			 * this does mean there is a short window where inp's
1270 			 * fields are unstable.  Could this lead to a
1271 			 * potential race in which the factors causing us to
1272 			 * select the UDPv4 output routine are invalidated?
1273 			 */
1274 			INP_WUNLOCK(inp);
1275 			if (sin6)
1276 				in6_sin6_2_sin_in_sock(addr);
1277 			pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1278 			/* addr will just be freed in sendit(). */
1279 			return ((*pru->pru_send)(so, flags, m, addr, control,
1280 			    td));
1281 		}
1282 	}
1283 #endif
1284 #ifdef MAC
1285 	mac_inpcb_create_mbuf(inp, m);
1286 #endif
1287 	INP_HASH_WLOCK(pcbinfo);
1288 	error = udp6_output(inp, m, addr, control, td);
1289 	INP_HASH_WUNLOCK(pcbinfo);
1290 	INP_WUNLOCK(inp);
1291 	return (error);
1292 
1293 bad:
1294 	INP_WUNLOCK(inp);
1295 	m_freem(m);
1296 	return (error);
1297 }
1298 
1299 struct pr_usrreqs udp6_usrreqs = {
1300 	.pru_abort =		udp6_abort,
1301 	.pru_attach =		udp6_attach,
1302 	.pru_bind =		udp6_bind,
1303 	.pru_connect =		udp6_connect,
1304 	.pru_control =		in6_control,
1305 	.pru_detach =		udp6_detach,
1306 	.pru_disconnect =	udp6_disconnect,
1307 	.pru_peeraddr =		in6_mapped_peeraddr,
1308 	.pru_send =		udp6_send,
1309 	.pru_shutdown =		udp_shutdown,
1310 	.pru_sockaddr =		in6_mapped_sockaddr,
1311 	.pru_soreceive =	soreceive_dgram,
1312 	.pru_sosend =		sosend_dgram,
1313 	.pru_sosetlabel =	in_pcbsosetlabel,
1314 	.pru_close =		udp6_close
1315 };
1316