xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
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_ipfw.h"
76 #include "opt_ipsec.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 
100 #include <netinet/in.h>
101 #include <netinet/in_kdtrace.h>
102 #include <netinet/in_pcb.h>
103 #include <netinet/in_systm.h>
104 #include <netinet/in_var.h>
105 #include <netinet/ip.h>
106 #include <netinet/ip_icmp.h>
107 #include <netinet/ip6.h>
108 #include <netinet/icmp_var.h>
109 #include <netinet/icmp6.h>
110 #include <netinet/ip_var.h>
111 #include <netinet/udp.h>
112 #include <netinet/udp_var.h>
113 #include <netinet/udplite.h>
114 
115 #include <netinet6/ip6protosw.h>
116 #include <netinet6/ip6_var.h>
117 #include <netinet6/in6_pcb.h>
118 #include <netinet6/udp6_var.h>
119 #include <netinet6/scope6_var.h>
120 
121 #ifdef IPSEC
122 #include <netipsec/ipsec.h>
123 #include <netipsec/ipsec6.h>
124 #endif /* IPSEC */
125 
126 #include <security/mac/mac_framework.h>
127 
128 /*
129  * UDP protocol implementation.
130  * Per RFC 768, August, 1980.
131  */
132 
133 extern struct protosw	inetsw[];
134 static void		udp6_detach(struct socket *so);
135 
136 static void
137 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
138     struct sockaddr_in6 *fromsa)
139 {
140 	struct socket *so;
141 	struct mbuf *opts;
142 
143 	INP_LOCK_ASSERT(inp);
144 
145 #ifdef IPSEC
146 	/* Check AH/ESP integrity. */
147 	if (ipsec6_in_reject(n, inp)) {
148 		m_freem(n);
149 		IPSEC6STAT_INC(ips_in_polvio);
150 		return;
151 	}
152 #endif /* IPSEC */
153 #ifdef MAC
154 	if (mac_inpcb_check_deliver(inp, n) != 0) {
155 		m_freem(n);
156 		return;
157 	}
158 #endif
159 	opts = NULL;
160 	if (inp->inp_flags & INP_CONTROLOPTS ||
161 	    inp->inp_socket->so_options & SO_TIMESTAMP)
162 		ip6_savecontrol(inp, n, &opts);
163 	m_adj(n, off + sizeof(struct udphdr));
164 
165 	so = inp->inp_socket;
166 	SOCKBUF_LOCK(&so->so_rcv);
167 	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
168 	    opts) == 0) {
169 		SOCKBUF_UNLOCK(&so->so_rcv);
170 		m_freem(n);
171 		if (opts)
172 			m_freem(opts);
173 		UDPSTAT_INC(udps_fullsock);
174 	} else
175 		sorwakeup_locked(so);
176 }
177 
178 int
179 udp6_input(struct mbuf **mp, int *offp, int proto)
180 {
181 	struct mbuf *m = *mp;
182 	struct ifnet *ifp;
183 	struct ip6_hdr *ip6;
184 	struct udphdr *uh;
185 	struct inpcb *inp;
186 	struct inpcbinfo *pcbinfo;
187 	struct udpcb *up;
188 	int off = *offp;
189 	int cscov_partial;
190 	int plen, ulen;
191 	struct sockaddr_in6 fromsa;
192 	struct m_tag *fwd_tag;
193 	uint16_t uh_sum;
194 	uint8_t nxt;
195 
196 	ifp = m->m_pkthdr.rcvif;
197 	ip6 = mtod(m, struct ip6_hdr *);
198 
199 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
200 		/* XXX send icmp6 host/port unreach? */
201 		m_freem(m);
202 		return (IPPROTO_DONE);
203 	}
204 
205 #ifndef PULLDOWN_TEST
206 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
207 	ip6 = mtod(m, struct ip6_hdr *);
208 	uh = (struct udphdr *)((caddr_t)ip6 + off);
209 #else
210 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
211 	if (!uh)
212 		return (IPPROTO_DONE);
213 #endif
214 
215 	UDPSTAT_INC(udps_ipackets);
216 
217 	/*
218 	 * Destination port of 0 is illegal, based on RFC768.
219 	 */
220 	if (uh->uh_dport == 0)
221 		goto badunlocked;
222 
223 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
224 	ulen = ntohs((u_short)uh->uh_ulen);
225 
226 	nxt = ip6->ip6_nxt;
227 	cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
228 	if (nxt == IPPROTO_UDPLITE && ulen == 0) {
229 		/* Zero means checksum over the complete packet. */
230 		ulen = plen;
231 		cscov_partial = 0;
232 	}
233 	if (plen != ulen) {
234 		UDPSTAT_INC(udps_badlen);
235 		goto badunlocked;
236 	}
237 
238 	/*
239 	 * Checksum extended UDP header and data.
240 	 */
241 	if (uh->uh_sum == 0) {
242 		if (ulen > plen || ulen < sizeof(struct udphdr)) {
243 			UDPSTAT_INC(udps_nosum);
244 			goto badunlocked;
245 		}
246 	}
247 
248 	if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
249 	    !cscov_partial) {
250 		if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
251 			uh_sum = m->m_pkthdr.csum_data;
252 		else
253 			uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
254 			    m->m_pkthdr.csum_data);
255 		uh_sum ^= 0xffff;
256 	} else
257 		uh_sum = in6_cksum(m, nxt, off, ulen);
258 
259 	if (uh_sum != 0) {
260 		UDPSTAT_INC(udps_badsum);
261 		goto badunlocked;
262 	}
263 
264 	/*
265 	 * Construct sockaddr format source address.
266 	 */
267 	init_sin6(&fromsa, m);
268 	fromsa.sin6_port = uh->uh_sport;
269 
270 	pcbinfo = get_inpcbinfo(nxt);
271 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
272 		struct inpcb *last;
273 		struct inpcbhead *pcblist;
274 		struct ip6_moptions *imo;
275 
276 		INP_INFO_RLOCK(pcbinfo);
277 		/*
278 		 * In the event that laddr should be set to the link-local
279 		 * address (this happens in RIPng), the multicast address
280 		 * specified in the received packet will not match laddr.  To
281 		 * handle this situation, matching is relaxed if the
282 		 * receiving interface is the same as one specified in the
283 		 * socket and if the destination multicast address matches
284 		 * one of the multicast groups specified in the socket.
285 		 */
286 
287 		/*
288 		 * KAME note: traditionally we dropped udpiphdr from mbuf
289 		 * here.  We need udphdr for IPsec processing so we do that
290 		 * later.
291 		 */
292 		pcblist = get_pcblist(nxt);
293 		last = NULL;
294 		LIST_FOREACH(inp, pcblist, inp_list) {
295 			if ((inp->inp_vflag & INP_IPV6) == 0)
296 				continue;
297 			if (inp->inp_lport != uh->uh_dport)
298 				continue;
299 			if (inp->inp_fport != 0 &&
300 			    inp->inp_fport != uh->uh_sport)
301 				continue;
302 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
303 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
304 							&ip6->ip6_dst))
305 					continue;
306 			}
307 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
308 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
309 							&ip6->ip6_src) ||
310 				    inp->inp_fport != uh->uh_sport)
311 					continue;
312 			}
313 
314 			/*
315 			 * XXXRW: Because we weren't holding either the inpcb
316 			 * or the hash lock when we checked for a match
317 			 * before, we should probably recheck now that the
318 			 * inpcb lock is (supposed to be) held.
319 			 */
320 
321 			/*
322 			 * Handle socket delivery policy for any-source
323 			 * and source-specific multicast. [RFC3678]
324 			 */
325 			imo = inp->in6p_moptions;
326 			if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
327 				struct sockaddr_in6	 mcaddr;
328 				int			 blocked;
329 
330 				INP_RLOCK(inp);
331 
332 				bzero(&mcaddr, sizeof(struct sockaddr_in6));
333 				mcaddr.sin6_len = sizeof(struct sockaddr_in6);
334 				mcaddr.sin6_family = AF_INET6;
335 				mcaddr.sin6_addr = ip6->ip6_dst;
336 
337 				blocked = im6o_mc_filter(imo, ifp,
338 					(struct sockaddr *)&mcaddr,
339 					(struct sockaddr *)&fromsa);
340 				if (blocked != MCAST_PASS) {
341 					if (blocked == MCAST_NOTGMEMBER)
342 						IP6STAT_INC(ip6s_notmember);
343 					if (blocked == MCAST_NOTSMEMBER ||
344 					    blocked == MCAST_MUTED)
345 						UDPSTAT_INC(udps_filtermcast);
346 					INP_RUNLOCK(inp); /* XXX */
347 					continue;
348 				}
349 
350 				INP_RUNLOCK(inp);
351 			}
352 			if (last != NULL) {
353 				struct mbuf *n;
354 
355 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
356 					INP_RLOCK(last);
357 					up = intoudpcb(last);
358 					if (up->u_tun_func == NULL) {
359 						udp6_append(last, n, off, &fromsa);
360 					} else {
361 						/*
362 						 * Engage the tunneling
363 						 * protocol we will have to
364 						 * leave the info_lock up,
365 						 * since we are hunting
366 						 * through multiple UDP's.
367 						 *
368 						 */
369 						(*up->u_tun_func)(n, off, last);
370 					}
371 					INP_RUNLOCK(last);
372 				}
373 			}
374 			last = inp;
375 			/*
376 			 * Don't look for additional matches if this one does
377 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
378 			 * socket options set.  This heuristic avoids
379 			 * searching through all pcbs in the common case of a
380 			 * non-shared port.  It assumes that an application
381 			 * will never clear these options after setting them.
382 			 */
383 			if ((last->inp_socket->so_options &
384 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
385 				break;
386 		}
387 
388 		if (last == NULL) {
389 			/*
390 			 * No matching pcb found; discard datagram.  (No need
391 			 * to send an ICMP Port Unreachable for a broadcast
392 			 * or multicast datgram.)
393 			 */
394 			UDPSTAT_INC(udps_noport);
395 			UDPSTAT_INC(udps_noportmcast);
396 			goto badheadlocked;
397 		}
398 		INP_RLOCK(last);
399 		INP_INFO_RUNLOCK(pcbinfo);
400 		up = intoudpcb(last);
401 		UDP_PROBE(receive, NULL, last, ip6, last, uh);
402 		if (up->u_tun_func == NULL) {
403 			udp6_append(last, m, off, &fromsa);
404 		} else {
405 			/*
406 			 * Engage the tunneling protocol.
407 			 */
408 			(*up->u_tun_func)(m, off, last);
409 		}
410 		INP_RUNLOCK(last);
411 		return (IPPROTO_DONE);
412 	}
413 	/*
414 	 * Locate pcb for datagram.
415 	 */
416 
417 	/*
418 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
419 	 */
420 	if ((m->m_flags & M_IP6_NEXTHOP) &&
421 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
422 		struct sockaddr_in6 *next_hop6;
423 
424 		next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
425 
426 		/*
427 		 * Transparently forwarded. Pretend to be the destination.
428 		 * Already got one like this?
429 		 */
430 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
431 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
432 		    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
433 		if (!inp) {
434 			/*
435 			 * It's new.  Try to find the ambushing socket.
436 			 * Because we've rewritten the destination address,
437 			 * any hardware-generated hash is ignored.
438 			 */
439 			inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
440 			    uh->uh_sport, &next_hop6->sin6_addr,
441 			    next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
442 			    uh->uh_dport, INPLOOKUP_WILDCARD |
443 			    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
444 		}
445 		/* Remove the tag from the packet. We don't need it anymore. */
446 		m_tag_delete(m, fwd_tag);
447 		m->m_flags &= ~M_IP6_NEXTHOP;
448 	} else
449 		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
450 		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
451 		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
452 		    m->m_pkthdr.rcvif, m);
453 	if (inp == NULL) {
454 		if (udp_log_in_vain) {
455 			char ip6bufs[INET6_ADDRSTRLEN];
456 			char ip6bufd[INET6_ADDRSTRLEN];
457 
458 			log(LOG_INFO,
459 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
460 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
461 			    ntohs(uh->uh_dport),
462 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
463 			    ntohs(uh->uh_sport));
464 		}
465 		UDPSTAT_INC(udps_noport);
466 		if (m->m_flags & M_MCAST) {
467 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
468 			UDPSTAT_INC(udps_noportmcast);
469 			goto badunlocked;
470 		}
471 		if (V_udp_blackhole)
472 			goto badunlocked;
473 		if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
474 			goto badunlocked;
475 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
476 		return (IPPROTO_DONE);
477 	}
478 	INP_RLOCK_ASSERT(inp);
479 	up = intoudpcb(inp);
480 	if (cscov_partial) {
481 		if (up->u_rxcslen > ulen) {
482 			INP_RUNLOCK(inp);
483 			m_freem(m);
484 			return (IPPROTO_DONE);
485 		}
486 	}
487 	UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
488 	if (up->u_tun_func == NULL) {
489 		udp6_append(inp, m, off, &fromsa);
490 	} else {
491 		/*
492 		 * Engage the tunneling protocol.
493 		 */
494 
495 		(*up->u_tun_func)(m, off, inp);
496 	}
497 	INP_RUNLOCK(inp);
498 	return (IPPROTO_DONE);
499 
500 badheadlocked:
501 	INP_INFO_RUNLOCK(pcbinfo);
502 badunlocked:
503 	if (m)
504 		m_freem(m);
505 	return (IPPROTO_DONE);
506 }
507 
508 static void
509 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
510     struct inpcbinfo *pcbinfo)
511 {
512 	struct udphdr uh;
513 	struct ip6_hdr *ip6;
514 	struct mbuf *m;
515 	int off = 0;
516 	struct ip6ctlparam *ip6cp = NULL;
517 	const struct sockaddr_in6 *sa6_src = NULL;
518 	void *cmdarg;
519 	struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
520 	struct udp_portonly {
521 		u_int16_t uh_sport;
522 		u_int16_t uh_dport;
523 	} *uhp;
524 
525 	if (sa->sa_family != AF_INET6 ||
526 	    sa->sa_len != sizeof(struct sockaddr_in6))
527 		return;
528 
529 	if ((unsigned)cmd >= PRC_NCMDS)
530 		return;
531 	if (PRC_IS_REDIRECT(cmd))
532 		notify = in6_rtchange, d = NULL;
533 	else if (cmd == PRC_HOSTDEAD)
534 		d = NULL;
535 	else if (inet6ctlerrmap[cmd] == 0)
536 		return;
537 
538 	/* if the parameter is from icmp6, decode it. */
539 	if (d != NULL) {
540 		ip6cp = (struct ip6ctlparam *)d;
541 		m = ip6cp->ip6c_m;
542 		ip6 = ip6cp->ip6c_ip6;
543 		off = ip6cp->ip6c_off;
544 		cmdarg = ip6cp->ip6c_cmdarg;
545 		sa6_src = ip6cp->ip6c_src;
546 	} else {
547 		m = NULL;
548 		ip6 = NULL;
549 		cmdarg = NULL;
550 		sa6_src = &sa6_any;
551 	}
552 
553 	if (ip6) {
554 		/*
555 		 * XXX: We assume that when IPV6 is non NULL,
556 		 * M and OFF are valid.
557 		 */
558 
559 		/* Check if we can safely examine src and dst ports. */
560 		if (m->m_pkthdr.len < off + sizeof(*uhp))
561 			return;
562 
563 		bzero(&uh, sizeof(uh));
564 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
565 
566 		(void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
567 		    (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
568 		    cmdarg, notify);
569 	} else
570 		(void)in6_pcbnotify(pcbinfo, sa, 0,
571 		    (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
572 }
573 
574 void
575 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
576 {
577 
578 	return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
579 }
580 
581 void
582 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
583 {
584 
585 	return (udp6_common_ctlinput(cmd, sa, d, &V_ulitecbinfo));
586 }
587 
588 static int
589 udp6_getcred(SYSCTL_HANDLER_ARGS)
590 {
591 	struct xucred xuc;
592 	struct sockaddr_in6 addrs[2];
593 	struct inpcb *inp;
594 	int error;
595 
596 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
597 	if (error)
598 		return (error);
599 
600 	if (req->newlen != sizeof(addrs))
601 		return (EINVAL);
602 	if (req->oldlen != sizeof(struct xucred))
603 		return (EINVAL);
604 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
605 	if (error)
606 		return (error);
607 	if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
608 	    (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
609 		return (error);
610 	}
611 	inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
612 	    addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
613 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
614 	if (inp != NULL) {
615 		INP_RLOCK_ASSERT(inp);
616 		if (inp->inp_socket == NULL)
617 			error = ENOENT;
618 		if (error == 0)
619 			error = cr_canseesocket(req->td->td_ucred,
620 			    inp->inp_socket);
621 		if (error == 0)
622 			cru2x(inp->inp_cred, &xuc);
623 		INP_RUNLOCK(inp);
624 	} else
625 		error = ENOENT;
626 	if (error == 0)
627 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
628 	return (error);
629 }
630 
631 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
632     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
633 
634 static int
635 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
636     struct mbuf *control, struct thread *td)
637 {
638 	u_int32_t ulen = m->m_pkthdr.len;
639 	u_int32_t plen = sizeof(struct udphdr) + ulen;
640 	struct ip6_hdr *ip6;
641 	struct udphdr *udp6;
642 	struct in6_addr *laddr, *faddr, in6a;
643 	struct sockaddr_in6 *sin6 = NULL;
644 	struct ifnet *oifp = NULL;
645 	int cscov_partial = 0;
646 	int scope_ambiguous = 0;
647 	u_short fport;
648 	int error = 0;
649 	uint8_t nxt;
650 	uint16_t cscov = 0;
651 	struct ip6_pktopts *optp, opt;
652 	int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
653 	int flags;
654 	struct sockaddr_in6 tmp;
655 
656 	INP_WLOCK_ASSERT(inp);
657 	INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
658 
659 	if (addr6) {
660 		/* addr6 has been validated in udp6_send(). */
661 		sin6 = (struct sockaddr_in6 *)addr6;
662 
663 		/* protect *sin6 from overwrites */
664 		tmp = *sin6;
665 		sin6 = &tmp;
666 
667 		/*
668 		 * Application should provide a proper zone ID or the use of
669 		 * default zone IDs should be enabled.  Unfortunately, some
670 		 * applications do not behave as it should, so we need a
671 		 * workaround.  Even if an appropriate ID is not determined,
672 		 * we'll see if we can determine the outgoing interface.  If we
673 		 * can, determine the zone ID based on the interface below.
674 		 */
675 		if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
676 			scope_ambiguous = 1;
677 		if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
678 			return (error);
679 	}
680 
681 	if (control) {
682 		if ((error = ip6_setpktopts(control, &opt,
683 		    inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
684 			goto release;
685 		optp = &opt;
686 	} else
687 		optp = inp->in6p_outputopts;
688 
689 	if (sin6) {
690 		faddr = &sin6->sin6_addr;
691 
692 		/*
693 		 * Since we saw no essential reason for calling in_pcbconnect,
694 		 * we get rid of such kind of logic, and call in6_selectsrc
695 		 * and in6_pcbsetport in order to fill in the local address
696 		 * and the local port.
697 		 */
698 		if (sin6->sin6_port == 0) {
699 			error = EADDRNOTAVAIL;
700 			goto release;
701 		}
702 
703 		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
704 			/* how about ::ffff:0.0.0.0 case? */
705 			error = EISCONN;
706 			goto release;
707 		}
708 
709 		fport = sin6->sin6_port; /* allow 0 port */
710 
711 		if (IN6_IS_ADDR_V4MAPPED(faddr)) {
712 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
713 				/*
714 				 * I believe we should explicitly discard the
715 				 * packet when mapped addresses are disabled,
716 				 * rather than send the packet as an IPv6 one.
717 				 * If we chose the latter approach, the packet
718 				 * might be sent out on the wire based on the
719 				 * default route, the situation which we'd
720 				 * probably want to avoid.
721 				 * (20010421 jinmei@kame.net)
722 				 */
723 				error = EINVAL;
724 				goto release;
725 			}
726 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
727 			    !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
728 				/*
729 				 * when remote addr is an IPv4-mapped address,
730 				 * local addr should not be an IPv6 address,
731 				 * since you cannot determine how to map IPv6
732 				 * source address to IPv4.
733 				 */
734 				error = EINVAL;
735 				goto release;
736 			}
737 
738 			af = AF_INET;
739 		}
740 
741 		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
742 			error = in6_selectsrc(sin6, optp, inp, NULL,
743 			    td->td_ucred, &oifp, &in6a);
744 			if (error)
745 				goto release;
746 			if (oifp && scope_ambiguous &&
747 			    (error = in6_setscope(&sin6->sin6_addr,
748 			    oifp, NULL))) {
749 				goto release;
750 			}
751 			laddr = &in6a;
752 		} else
753 			laddr = &inp->in6p_laddr;	/* XXX */
754 		if (laddr == NULL) {
755 			if (error == 0)
756 				error = EADDRNOTAVAIL;
757 			goto release;
758 		}
759 		if (inp->inp_lport == 0 &&
760 		    (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
761 			/* Undo an address bind that may have occurred. */
762 			inp->in6p_laddr = in6addr_any;
763 			goto release;
764 		}
765 	} else {
766 		if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
767 			error = ENOTCONN;
768 			goto release;
769 		}
770 		if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
771 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
772 				/*
773 				 * XXX: this case would happen when the
774 				 * application sets the V6ONLY flag after
775 				 * connecting the foreign address.
776 				 * Such applications should be fixed,
777 				 * so we bark here.
778 				 */
779 				log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
780 				    "option was set for a connected socket\n");
781 				error = EINVAL;
782 				goto release;
783 			} else
784 				af = AF_INET;
785 		}
786 		laddr = &inp->in6p_laddr;
787 		faddr = &inp->in6p_faddr;
788 		fport = inp->inp_fport;
789 	}
790 
791 	if (af == AF_INET)
792 		hlen = sizeof(struct ip);
793 
794 	/*
795 	 * Calculate data length and get a mbuf
796 	 * for UDP and IP6 headers.
797 	 */
798 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
799 	if (m == 0) {
800 		error = ENOBUFS;
801 		goto release;
802 	}
803 
804 	/*
805 	 * Stuff checksum and output datagram.
806 	 */
807 	nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
808 	    IPPROTO_UDP : IPPROTO_UDPLITE;
809 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
810 	udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
811 	udp6->uh_dport = fport;
812 	if (nxt == IPPROTO_UDPLITE) {
813 		struct udpcb *up;
814 
815 		up = intoudpcb(inp);
816 		cscov = up->u_txcslen;
817 		if (cscov >= plen)
818 			cscov = 0;
819 		udp6->uh_ulen = htons(cscov);
820 		/*
821 		 * For UDP-Lite, checksum coverage length of zero means
822 		 * the entire UDPLite packet is covered by the checksum.
823 		 */
824 		cscov_partial = (cscov == 0) ? 0 : 1;
825 	} else if (plen <= 0xffff)
826 		udp6->uh_ulen = htons((u_short)plen);
827 	else
828 		udp6->uh_ulen = 0;
829 	udp6->uh_sum = 0;
830 
831 	switch (af) {
832 	case AF_INET6:
833 		ip6 = mtod(m, struct ip6_hdr *);
834 		ip6->ip6_flow	= inp->inp_flow & IPV6_FLOWINFO_MASK;
835 		ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
836 		ip6->ip6_vfc	|= IPV6_VERSION;
837 		ip6->ip6_plen	= htons((u_short)plen);
838 		ip6->ip6_nxt	= nxt;
839 		ip6->ip6_hlim	= in6_selecthlim(inp, NULL);
840 		ip6->ip6_src	= *laddr;
841 		ip6->ip6_dst	= *faddr;
842 
843 		if (cscov_partial) {
844 			if ((udp6->uh_sum = in6_cksum(m, 0,
845 			    sizeof(struct ip6_hdr), cscov)) == 0)
846 				udp6->uh_sum = 0xffff;
847 		} else {
848 			udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
849 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
850 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
851 		}
852 
853 		flags = 0;
854 
855 		UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
856 		UDPSTAT_INC(udps_opackets);
857 		error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
858 		    NULL, inp);
859 		break;
860 	case AF_INET:
861 		error = EAFNOSUPPORT;
862 		goto release;
863 	}
864 	goto releaseopt;
865 
866 release:
867 	m_freem(m);
868 
869 releaseopt:
870 	if (control) {
871 		ip6_clearpktopts(&opt, -1);
872 		m_freem(control);
873 	}
874 	return (error);
875 }
876 
877 static void
878 udp6_abort(struct socket *so)
879 {
880 	struct inpcb *inp;
881 	struct inpcbinfo *pcbinfo;
882 
883 	pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
884 	inp = sotoinpcb(so);
885 	KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
886 
887 #ifdef INET
888 	if (inp->inp_vflag & INP_IPV4) {
889 		struct pr_usrreqs *pru;
890 
891 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
892 		(*pru->pru_abort)(so);
893 		return;
894 	}
895 #endif
896 
897 	INP_WLOCK(inp);
898 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
899 		INP_HASH_WLOCK(pcbinfo);
900 		in6_pcbdisconnect(inp);
901 		inp->in6p_laddr = in6addr_any;
902 		INP_HASH_WUNLOCK(pcbinfo);
903 		soisdisconnected(so);
904 	}
905 	INP_WUNLOCK(inp);
906 }
907 
908 static int
909 udp6_attach(struct socket *so, int proto, struct thread *td)
910 {
911 	struct inpcb *inp;
912 	struct inpcbinfo *pcbinfo;
913 	int error;
914 
915 	pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
916 	inp = sotoinpcb(so);
917 	KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
918 
919 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
920 		error = soreserve(so, udp_sendspace, udp_recvspace);
921 		if (error)
922 			return (error);
923 	}
924 	INP_INFO_WLOCK(pcbinfo);
925 	error = in_pcballoc(so, pcbinfo);
926 	if (error) {
927 		INP_INFO_WUNLOCK(pcbinfo);
928 		return (error);
929 	}
930 	inp = (struct inpcb *)so->so_pcb;
931 	inp->inp_vflag |= INP_IPV6;
932 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
933 		inp->inp_vflag |= INP_IPV4;
934 	inp->in6p_hops = -1;	/* use kernel default */
935 	inp->in6p_cksum = -1;	/* just to be sure */
936 	/*
937 	 * XXX: ugly!!
938 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
939 	 * because the socket may be bound to an IPv6 wildcard address,
940 	 * which may match an IPv4-mapped IPv6 address.
941 	 */
942 	inp->inp_ip_ttl = V_ip_defttl;
943 
944 	error = udp_newudpcb(inp);
945 	if (error) {
946 		in_pcbdetach(inp);
947 		in_pcbfree(inp);
948 		INP_INFO_WUNLOCK(pcbinfo);
949 		return (error);
950 	}
951 	INP_WUNLOCK(inp);
952 	INP_INFO_WUNLOCK(pcbinfo);
953 	return (0);
954 }
955 
956 static int
957 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
958 {
959 	struct inpcb *inp;
960 	struct inpcbinfo *pcbinfo;
961 	int error;
962 
963 	pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
964 	inp = sotoinpcb(so);
965 	KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
966 
967 	INP_WLOCK(inp);
968 	INP_HASH_WLOCK(pcbinfo);
969 	inp->inp_vflag &= ~INP_IPV4;
970 	inp->inp_vflag |= INP_IPV6;
971 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
972 		struct sockaddr_in6 *sin6_p;
973 
974 		sin6_p = (struct sockaddr_in6 *)nam;
975 
976 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
977 			inp->inp_vflag |= INP_IPV4;
978 #ifdef INET
979 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
980 			struct sockaddr_in sin;
981 
982 			in6_sin6_2_sin(&sin, sin6_p);
983 			inp->inp_vflag |= INP_IPV4;
984 			inp->inp_vflag &= ~INP_IPV6;
985 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
986 			    td->td_ucred);
987 			goto out;
988 		}
989 #endif
990 	}
991 
992 	error = in6_pcbbind(inp, nam, td->td_ucred);
993 #ifdef INET
994 out:
995 #endif
996 	INP_HASH_WUNLOCK(pcbinfo);
997 	INP_WUNLOCK(inp);
998 	return (error);
999 }
1000 
1001 static void
1002 udp6_close(struct socket *so)
1003 {
1004 	struct inpcb *inp;
1005 	struct inpcbinfo *pcbinfo;
1006 
1007 	pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1008 	inp = sotoinpcb(so);
1009 	KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
1010 
1011 #ifdef INET
1012 	if (inp->inp_vflag & INP_IPV4) {
1013 		struct pr_usrreqs *pru;
1014 
1015 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1016 		(*pru->pru_disconnect)(so);
1017 		return;
1018 	}
1019 #endif
1020 	INP_WLOCK(inp);
1021 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1022 		INP_HASH_WLOCK(pcbinfo);
1023 		in6_pcbdisconnect(inp);
1024 		inp->in6p_laddr = in6addr_any;
1025 		INP_HASH_WUNLOCK(pcbinfo);
1026 		soisdisconnected(so);
1027 	}
1028 	INP_WUNLOCK(inp);
1029 }
1030 
1031 static int
1032 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1033 {
1034 	struct inpcb *inp;
1035 	struct inpcbinfo *pcbinfo;
1036 	struct sockaddr_in6 *sin6;
1037 	int error;
1038 
1039 	pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1040 	inp = sotoinpcb(so);
1041 	sin6 = (struct sockaddr_in6 *)nam;
1042 	KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1043 
1044 	/*
1045 	 * XXXRW: Need to clarify locking of v4/v6 flags.
1046 	 */
1047 	INP_WLOCK(inp);
1048 #ifdef INET
1049 	if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1050 		struct sockaddr_in sin;
1051 
1052 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1053 			error = EINVAL;
1054 			goto out;
1055 		}
1056 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1057 			error = EISCONN;
1058 			goto out;
1059 		}
1060 		in6_sin6_2_sin(&sin, sin6);
1061 		inp->inp_vflag |= INP_IPV4;
1062 		inp->inp_vflag &= ~INP_IPV6;
1063 		error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1064 		if (error != 0)
1065 			goto out;
1066 		INP_HASH_WLOCK(pcbinfo);
1067 		error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1068 		    td->td_ucred);
1069 		INP_HASH_WUNLOCK(pcbinfo);
1070 		if (error == 0)
1071 			soisconnected(so);
1072 		goto out;
1073 	}
1074 #endif
1075 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1076 		error = EISCONN;
1077 		goto out;
1078 	}
1079 	inp->inp_vflag &= ~INP_IPV4;
1080 	inp->inp_vflag |= INP_IPV6;
1081 	error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1082 	if (error != 0)
1083 		goto out;
1084 	INP_HASH_WLOCK(pcbinfo);
1085 	error = in6_pcbconnect(inp, nam, td->td_ucred);
1086 	INP_HASH_WUNLOCK(pcbinfo);
1087 	if (error == 0)
1088 		soisconnected(so);
1089 out:
1090 	INP_WUNLOCK(inp);
1091 	return (error);
1092 }
1093 
1094 static void
1095 udp6_detach(struct socket *so)
1096 {
1097 	struct inpcb *inp;
1098 	struct inpcbinfo *pcbinfo;
1099 	struct udpcb *up;
1100 
1101 	pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1102 	inp = sotoinpcb(so);
1103 	KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1104 
1105 	INP_INFO_WLOCK(pcbinfo);
1106 	INP_WLOCK(inp);
1107 	up = intoudpcb(inp);
1108 	KASSERT(up != NULL, ("%s: up == NULL", __func__));
1109 	in_pcbdetach(inp);
1110 	in_pcbfree(inp);
1111 	INP_INFO_WUNLOCK(pcbinfo);
1112 	udp_discardcb(up);
1113 }
1114 
1115 static int
1116 udp6_disconnect(struct socket *so)
1117 {
1118 	struct inpcb *inp;
1119 	struct inpcbinfo *pcbinfo;
1120 	int error;
1121 
1122 	pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1123 	inp = sotoinpcb(so);
1124 	KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1125 
1126 #ifdef INET
1127 	if (inp->inp_vflag & INP_IPV4) {
1128 		struct pr_usrreqs *pru;
1129 
1130 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1131 		(void)(*pru->pru_disconnect)(so);
1132 		return (0);
1133 	}
1134 #endif
1135 
1136 	INP_WLOCK(inp);
1137 
1138 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1139 		error = ENOTCONN;
1140 		goto out;
1141 	}
1142 
1143 	INP_HASH_WLOCK(pcbinfo);
1144 	in6_pcbdisconnect(inp);
1145 	inp->in6p_laddr = in6addr_any;
1146 	INP_HASH_WUNLOCK(pcbinfo);
1147 	SOCK_LOCK(so);
1148 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1149 	SOCK_UNLOCK(so);
1150 out:
1151 	INP_WUNLOCK(inp);
1152 	return (0);
1153 }
1154 
1155 static int
1156 udp6_send(struct socket *so, int flags, struct mbuf *m,
1157     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1158 {
1159 	struct inpcb *inp;
1160 	struct inpcbinfo *pcbinfo;
1161 	int error = 0;
1162 
1163 	pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1164 	inp = sotoinpcb(so);
1165 	KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1166 
1167 	INP_WLOCK(inp);
1168 	if (addr) {
1169 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1170 			error = EINVAL;
1171 			goto bad;
1172 		}
1173 		if (addr->sa_family != AF_INET6) {
1174 			error = EAFNOSUPPORT;
1175 			goto bad;
1176 		}
1177 	}
1178 
1179 #ifdef INET
1180 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1181 		int hasv4addr;
1182 		struct sockaddr_in6 *sin6 = 0;
1183 
1184 		if (addr == 0)
1185 			hasv4addr = (inp->inp_vflag & INP_IPV4);
1186 		else {
1187 			sin6 = (struct sockaddr_in6 *)addr;
1188 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1189 			    ? 1 : 0;
1190 		}
1191 		if (hasv4addr) {
1192 			struct pr_usrreqs *pru;
1193 
1194 			/*
1195 			 * XXXRW: We release UDP-layer locks before calling
1196 			 * udp_send() in order to avoid recursion.  However,
1197 			 * this does mean there is a short window where inp's
1198 			 * fields are unstable.  Could this lead to a
1199 			 * potential race in which the factors causing us to
1200 			 * select the UDPv4 output routine are invalidated?
1201 			 */
1202 			INP_WUNLOCK(inp);
1203 			if (sin6)
1204 				in6_sin6_2_sin_in_sock(addr);
1205 			pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1206 			/* addr will just be freed in sendit(). */
1207 			return ((*pru->pru_send)(so, flags, m, addr, control,
1208 			    td));
1209 		}
1210 	}
1211 #endif
1212 #ifdef MAC
1213 	mac_inpcb_create_mbuf(inp, m);
1214 #endif
1215 	INP_HASH_WLOCK(pcbinfo);
1216 	error = udp6_output(inp, m, addr, control, td);
1217 	INP_HASH_WUNLOCK(pcbinfo);
1218 #ifdef INET
1219 #endif
1220 	INP_WUNLOCK(inp);
1221 	return (error);
1222 
1223 bad:
1224 	INP_WUNLOCK(inp);
1225 	m_freem(m);
1226 	return (error);
1227 }
1228 
1229 struct pr_usrreqs udp6_usrreqs = {
1230 	.pru_abort =		udp6_abort,
1231 	.pru_attach =		udp6_attach,
1232 	.pru_bind =		udp6_bind,
1233 	.pru_connect =		udp6_connect,
1234 	.pru_control =		in6_control,
1235 	.pru_detach =		udp6_detach,
1236 	.pru_disconnect =	udp6_disconnect,
1237 	.pru_peeraddr =		in6_mapped_peeraddr,
1238 	.pru_send =		udp6_send,
1239 	.pru_shutdown =		udp_shutdown,
1240 	.pru_sockaddr =		in6_mapped_sockaddr,
1241 	.pru_soreceive =	soreceive_dgram,
1242 	.pru_sosend =		sosend_dgram,
1243 	.pru_sosetlabel =	in_pcbsosetlabel,
1244 	.pru_close =		udp6_close
1245 };
1246