xref: /netbsd-src/sys/netinet6/udp6_usrreq.c (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1 /*	$NetBSD: udp6_usrreq.c,v 1.32 2000/07/07 15:54:19 itojun Exp $	*/
2 /*	$KAME: udp6_usrreq.c,v 1.55 2000/06/13 11:40:15 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1989, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *	This product includes software developed by the University of
48  *	California, Berkeley and its contributors.
49  * 4. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
66  */
67 
68 #include "opt_ipsec.h"
69 
70 #include <sys/param.h>
71 #include <sys/malloc.h>
72 #include <sys/mbuf.h>
73 #include <sys/protosw.h>
74 #include <sys/socket.h>
75 #include <sys/socketvar.h>
76 #include <sys/errno.h>
77 #include <sys/stat.h>
78 #include <sys/systm.h>
79 #include <sys/proc.h>
80 #include <sys/syslog.h>
81 
82 #include <net/if.h>
83 #include <net/route.h>
84 #include <net/if_types.h>
85 
86 #include <netinet/in.h>
87 #include <netinet/in_var.h>
88 #include <netinet/in_systm.h>
89 #include <netinet/ip.h>
90 #include <netinet/ip_var.h>
91 #include <netinet/in_pcb.h>
92 #include <netinet/udp.h>
93 #include <netinet/udp_var.h>
94 #include <netinet/ip6.h>
95 #include <netinet6/ip6_var.h>
96 #include <netinet6/in6_pcb.h>
97 #include <netinet/icmp6.h>
98 #include <netinet6/udp6_var.h>
99 #include <netinet6/ip6protosw.h>
100 
101 #ifdef IPSEC
102 #include <netinet6/ipsec.h>
103 #endif /*IPSEC*/
104 
105 #include "faith.h"
106 
107 /*
108  * UDP protocol inplementation.
109  * Per RFC 768, August, 1980.
110  */
111 
112 struct	in6pcb *udp6_last_in6pcb = &udb6;
113 
114 #ifdef UDP6
115 static	int in6_mcmatch __P((struct in6pcb *, struct in6_addr *, struct ifnet *));
116 #endif
117 static	void udp6_detach __P((struct in6pcb *));
118 static	void udp6_notify __P((struct in6pcb *, int));
119 
120 void
121 udp6_init()
122 {
123 	udb6.in6p_next = udb6.in6p_prev = &udb6;
124 }
125 
126 #ifdef UDP6
127 static int
128 in6_mcmatch(in6p, ia6, ifp)
129 	struct in6pcb *in6p;
130 	register struct in6_addr *ia6;
131 	struct ifnet *ifp;
132 {
133 	struct ip6_moptions *im6o = in6p->in6p_moptions;
134 	struct in6_multi_mship *imm;
135 
136 	if (im6o == NULL)
137 		return 0;
138 
139 	for (imm = im6o->im6o_memberships.lh_first; imm != NULL;
140 	     imm = imm->i6mm_chain.le_next) {
141 		if ((ifp == NULL ||
142 		     imm->i6mm_maddr->in6m_ifp == ifp) &&
143 		    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
144 				       ia6))
145 			return 1;
146 	}
147 	return 0;
148 }
149 
150 int
151 udp6_input(mp, offp, proto)
152 	struct mbuf **mp;
153 	int *offp, proto;
154 {
155 	struct mbuf *m = *mp;
156 	register struct ip6_hdr *ip6;
157 	register struct udphdr *uh;
158 	register struct in6pcb *in6p;
159 	struct	mbuf *opts = 0;
160 	int off = *offp;
161 	u_int32_t plen, ulen;
162 	struct sockaddr_in6 udp_in6;
163 
164 #if defined(NFAITH) && 0 < NFAITH
165 	if (m->m_pkthdr.rcvif) {
166 		if (m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
167 			/* send icmp6 host unreach? */
168 			m_freem(m);
169 			return IPPROTO_DONE;
170 		}
171 	}
172 #endif
173 	udp6stat.udp6s_ipackets++;
174 
175 	ip6 = mtod(m, struct ip6_hdr *);
176 	/* check for jumbogram is done in ip6_input.  we can trust pkthdr.len */
177 	plen = m->m_pkthdr.len - off;
178 #ifndef PULLDOWN_TEST
179 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
180 	uh = (struct udphdr *)((caddr_t)ip6 + off);
181 #else
182 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(struct udphdr));
183 	if (uh == NULL) {
184 		udp6stat.udp6s_hdrops++;
185 		return IPPROTO_DONE;
186 	}
187 #endif
188 	ulen = ntohs((u_short)uh->uh_ulen);
189 	/*
190 	 * RFC2675 section 4: jumbograms will have 0 in the UDP header field,
191 	 * iff payload length > 0xffff.
192 	 */
193 	if (ulen == 0 && plen > 0xffff)
194 		ulen = plen;
195 
196 	if (plen != ulen) {
197 		udp6stat.udp6s_badlen++;
198 		goto bad;
199 	}
200 
201 	/* destination port of 0 is illegal, based on RFC768. */
202 	if (uh->uh_dport == 0)
203 		goto bad;
204 
205 	/* Be proactive about malicious use of IPv4 mapped address */
206 	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
207 	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
208 		/* XXX stat */
209 		goto bad;
210 	}
211 
212 	/*
213 	 * Checksum extended UDP header and data.
214 	 */
215 	if (uh->uh_sum == 0)
216 		udp6stat.udp6s_nosum++;
217 	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
218 		udp6stat.udp6s_badsum++;
219 		goto bad;
220 	}
221 
222 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
223 		struct	in6pcb *last;
224 
225 		/*
226 		 * Deliver a multicast datagram to all sockets
227 		 * for which the local and remote addresses and ports match
228 		 * those of the incoming datagram.  This allows more than
229 		 * one process to receive multicasts on the same port.
230 		 * (This really ought to be done for unicast datagrams as
231 		 * well, but that would cause problems with existing
232 		 * applications that open both address-specific sockets and
233 		 * a wildcard socket listening to the same port -- they would
234 		 * end up receiving duplicates of every unicast datagram.
235 		 * Those applications open the multiple sockets to overcome an
236 		 * inadequacy of the UDP socket interface, but for backwards
237 		 * compatibility we avoid the problem here rather than
238 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
239 		 */
240 
241 		/*
242 		 * In a case that laddr should be set to the link-local
243 		 * address (this happens in RIPng), the multicast address
244 		 * specified in the received packet does not match with
245 		 * laddr. To cure this situation, the matching is relaxed
246 		 * if the receiving interface is the same as one specified
247 		 * in the socket and if the destination multicast address
248 		 * matches one of the multicast groups specified in the socket.
249 		 */
250 
251 		/*
252 		 * Construct sockaddr format source address.
253 		 */
254 		bzero(&udp_in6, sizeof(udp_in6));
255 		udp_in6.sin6_len = sizeof(struct sockaddr_in6);
256 		udp_in6.sin6_family = AF_INET6;
257 		udp_in6.sin6_port = uh->uh_sport;
258 #if 0 /*XXX inbound flowinfo */
259 		udp_in6.sin6_flowinfo = ip6->ip6_flow & IPV6_FLOWINFO_MASK;
260 #endif
261 		/* KAME hack: recover scopeid */
262 		(void)in6_recoverscope(&udp_in6, &ip6->ip6_src,
263 		    m->m_pkthdr.rcvif);
264 
265 		/*
266 		 * KAME note: usually we drop udphdr from mbuf here.
267 		 * We need udphdr for IPsec processing so we do that later.
268 		 */
269 
270 		/*
271 		 * Locate pcb(s) for datagram.
272 		 * (Algorithm copied from raw_intr().)
273 		 */
274 		last = NULL;
275 		for (in6p = udb6.in6p_next;
276 		     in6p != &udb6;
277 		     in6p = in6p->in6p_next) {
278 			if (in6p->in6p_lport != uh->uh_dport)
279 				continue;
280 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
281 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
282 							&ip6->ip6_dst) &&
283 				    !in6_mcmatch(in6p, &ip6->ip6_dst,
284 						 m->m_pkthdr.rcvif))
285 					continue;
286 			}
287 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
288 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
289 							&ip6->ip6_src) ||
290 				   in6p->in6p_fport != uh->uh_sport)
291 					continue;
292 			}
293 
294 			if (last != NULL) {
295 				struct	mbuf *n;
296 
297 #ifdef IPSEC
298 				/*
299 				 * Check AH/ESP integrity.
300 				 */
301 				if (ipsec6_in_reject(m, last)) {
302 					ipsec6stat.in_polvio++;
303 					/* do not inject data into pcb */
304 				} else
305 #endif /*IPSEC*/
306 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
307 					/*
308 					 * KAME NOTE: do not
309 					 * m_copy(m, offset, ...) above.
310 					 * sbappendaddr() expects M_PKTHDR,
311 					 * and m_copy() will copy M_PKTHDR
312 					 * only if offset is 0.
313 					 */
314 					if (last->in6p_flags & IN6P_CONTROLOPTS
315 					 || last->in6p_socket->so_options & SO_TIMESTAMP) {
316 						ip6_savecontrol(last, &opts,
317 								ip6, n);
318 					}
319 
320 					m_adj(n, off + sizeof(struct udphdr));
321 					if (sbappendaddr(&last->in6p_socket->so_rcv,
322 							(struct sockaddr *)&udp_in6,
323 							n, opts) == 0) {
324 						m_freem(n);
325 						if (opts)
326 							m_freem(opts);
327 						udp6stat.udp6s_fullsock++;
328 					} else
329 						sorwakeup(last->in6p_socket);
330 					opts = 0;
331 				}
332 			}
333 			last = in6p;
334 			/*
335 			 * Don't look for additional matches if this one does
336 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
337 			 * socket options set.  This heuristic avoids searching
338 			 * through all pcbs in the common case of a non-shared
339 			 * port.  It assumes that an application will never
340 			 * clear these options after setting them.
341 			 */
342 			if ((last->in6p_socket->so_options &
343 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
344 				break;
345 		}
346 
347 		if (last == NULL) {
348 			/*
349 			 * No matching pcb found; discard datagram.
350 			 * (No need to send an ICMP Port Unreachable
351 			 * for a broadcast or multicast datgram.)
352 			 */
353 			udp6stat.udp6s_noport++;
354 			udp6stat.udp6s_noportmcast++;
355 			goto bad;
356 		}
357 #ifdef IPSEC
358 		/*
359 		 * Check AH/ESP integrity.
360 		 */
361 		if (last != NULL && ipsec6_in_reject(m, last)) {
362 			ipsec6stat.in_polvio++;
363 			goto bad;
364 		}
365 #endif /*IPSEC*/
366 		if (last->in6p_flags & IN6P_CONTROLOPTS
367 		 || last->in6p_socket->so_options & SO_TIMESTAMP) {
368 			ip6_savecontrol(last, &opts, ip6, m);
369 		}
370 
371 		m_adj(m, off + sizeof(struct udphdr));
372 		if (sbappendaddr(&last->in6p_socket->so_rcv,
373 				(struct sockaddr *)&udp_in6,
374 				m, opts) == 0) {
375 			udp6stat.udp6s_fullsock++;
376 			goto bad;
377 		}
378 		sorwakeup(last->in6p_socket);
379 		return IPPROTO_DONE;
380 	}
381 	/*
382 	 * Locate pcb for datagram.
383 	 */
384 	in6p = udp6_last_in6pcb;
385 	if (in6p->in6p_lport != uh->uh_dport ||
386 	   in6p->in6p_fport != uh->uh_sport ||
387 	   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src) ||
388 	   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) {
389 		in6p = in6_pcblookup(&udb6,
390 				     &ip6->ip6_src, uh->uh_sport,
391 				     &ip6->ip6_dst, uh->uh_dport,
392 				     IN6PLOOKUP_WILDCARD);
393 		if (in6p)
394 			udp6_last_in6pcb = in6p;
395 		udp6stat.udp6ps_pcbcachemiss++;
396 	}
397 	if (in6p == 0) {
398 		udp6stat.udp6s_noport++;
399 		if (m->m_flags & M_MCAST) {
400 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
401 			udp6stat.udp6s_noportmcast++;
402 			goto bad;
403 		}
404 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
405 		return IPPROTO_DONE;
406 	}
407 #ifdef IPSEC
408 	/*
409 	 * Check AH/ESP integrity.
410 	 */
411 	if (in6p != NULL && ipsec6_in_reject(m, in6p)) {
412 		ipsec6stat.in_polvio++;
413 		goto bad;
414 	}
415 #endif /*IPSEC*/
416 
417 	/*
418 	 * Construct sockaddr format source address.
419 	 * Stuff source address and datagram in user buffer.
420 	 */
421 	bzero(&udp_in6, sizeof(udp_in6));
422 	udp_in6.sin6_len = sizeof(struct sockaddr_in6);
423 	udp_in6.sin6_family = AF_INET6;
424 	udp_in6.sin6_port = uh->uh_sport;
425 	/* KAME hack: recover scopeid */
426 	(void)in6_recoverscope(&udp_in6, &ip6->ip6_src, m->m_pkthdr.rcvif);
427 	if (in6p->in6p_flags & IN6P_CONTROLOPTS
428 	 || in6p->in6p_socket->so_options & SO_TIMESTAMP) {
429 		ip6_savecontrol(in6p, &opts, ip6, m);
430 	}
431 
432 	m_adj(m, off + sizeof(struct udphdr));
433 	if (sbappendaddr(&in6p->in6p_socket->so_rcv,
434 			(struct sockaddr *)&udp_in6,
435 			m, opts) == 0) {
436 		udp6stat.udp6s_fullsock++;
437 		goto bad;
438 	}
439 	sorwakeup(in6p->in6p_socket);
440 	return IPPROTO_DONE;
441 bad:
442 	if (m)
443 		m_freem(m);
444 	if (opts)
445 		m_freem(opts);
446 	return IPPROTO_DONE;
447 }
448 #endif
449 
450 /*
451  * Notify a udp user of an asynchronous error;
452  * just wake up so that he can collect error status.
453  */
454 static	void
455 udp6_notify(in6p, errno)
456 	register struct in6pcb *in6p;
457 	int errno;
458 {
459 	in6p->in6p_socket->so_error = errno;
460 	sorwakeup(in6p->in6p_socket);
461 	sowwakeup(in6p->in6p_socket);
462 }
463 
464 void
465 udp6_ctlinput(cmd, sa, d)
466 	int cmd;
467 	struct sockaddr *sa;
468 	void *d;
469 {
470 	register struct udphdr *uhp;
471 	struct udphdr uh;
472 	struct sockaddr_in6 sa6;
473 	register struct ip6_hdr *ip6;
474 	struct mbuf *m;
475 	int off;
476 	void (*notify) __P((struct in6pcb *, int)) = udp6_notify;
477 
478 	if (sa->sa_family != AF_INET6 ||
479 	    sa->sa_len != sizeof(struct sockaddr_in6))
480 		return;
481 
482 	if ((unsigned)cmd >= PRC_NCMDS)
483 		return;
484 	if (PRC_IS_REDIRECT(cmd))
485 		notify = in6_rtchange, d = NULL;
486 	else if (cmd == PRC_HOSTDEAD)
487 		d = NULL;
488 	else if (inet6ctlerrmap[cmd] == 0)
489 		return;
490 
491 	/* if the parameter is from icmp6, decode it. */
492 	if (d != NULL) {
493 		struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d;
494 		m = ip6cp->ip6c_m;
495 		ip6 = ip6cp->ip6c_ip6;
496 		off = ip6cp->ip6c_off;
497 	} else {
498 		m = NULL;
499 		ip6 = NULL;
500 	}
501 
502 	/* translate addresses into internal form */
503 	sa6 = *(struct sockaddr_in6 *)sa;
504 	if (IN6_IS_ADDR_LINKLOCAL(&sa6.sin6_addr) && m && m->m_pkthdr.rcvif)
505 		sa6.sin6_addr.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
506 
507 	if (ip6) {
508 		/*
509 		 * XXX: We assume that when IPV6 is non NULL,
510 		 * M and OFF are valid.
511 		 */
512 		struct in6_addr s;
513 
514 		/* translate addresses into internal form */
515 		memcpy(&s, &ip6->ip6_src, sizeof(s));
516 		if (IN6_IS_ADDR_LINKLOCAL(&s))
517 			s.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
518 
519 		if (m->m_len < off + sizeof(uh)) {
520 			/*
521 			 * this should be rare case,
522 			 * so we compromise on this copy...
523 			 */
524 			m_copydata(m, off, sizeof(uh), (caddr_t)&uh);
525 			uhp = &uh;
526 		} else
527 			uhp = (struct udphdr *)(mtod(m, caddr_t) + off);
528 		(void) in6_pcbnotify(&udb6, (struct sockaddr *)&sa6,
529 					uhp->uh_dport, &s,
530 					uhp->uh_sport, cmd, notify);
531 	} else {
532 		(void) in6_pcbnotify(&udb6, (struct sockaddr *)&sa6, 0,
533 					&zeroin6_addr, 0, cmd, notify);
534 	}
535 }
536 
537 int
538 udp6_output(in6p, m, addr6, control, p)
539 	register struct in6pcb *in6p;
540 	register struct mbuf *m;
541 	struct mbuf *addr6, *control;
542 	struct proc *p;
543 {
544 	register u_int32_t ulen = m->m_pkthdr.len;
545 	u_int32_t plen = sizeof(struct udphdr) + ulen;
546 	struct ip6_hdr *ip6;
547 	struct udphdr *udp6;
548 	struct	in6_addr *laddr, *faddr;
549 	u_short fport;
550 	int error = 0;
551 	struct ip6_pktopts opt, *stickyopt = in6p->in6p_outputopts;
552 	int priv;
553 	int af, hlen;
554 #ifdef INET
555 	struct ip *ip;
556 #endif
557 	struct sockaddr_in6 tmp;
558 
559 	priv = 0;
560 	if (p && !suser(p->p_ucred, &p->p_acflag))
561 		priv = 1;
562 	if (control) {
563 		if ((error = ip6_setpktoptions(control, &opt, priv)) != 0)
564 			goto release;
565 		in6p->in6p_outputopts = &opt;
566 	}
567 
568 	if (addr6) {
569 		/*
570 		 * IPv4 version of udp_output calls in_pcbconnect in this case,
571 		 * which needs splnet and affects performance.
572 		 * Since we saw no essential reason for calling in_pcbconnect,
573 		 * we get rid of such kind of logic, and call in6_selectsrc
574 		 * and In6_pcbsetport in order to fill in the local address
575 		 * and the local port.
576 		 */
577 		struct sockaddr_in6 *sin6 = mtod(addr6, struct sockaddr_in6 *);
578 
579 		if (addr6->m_len != sizeof(*sin6)) {
580 			error = EINVAL;
581 			goto release;
582 		}
583 		if (sin6->sin6_family != AF_INET6) {
584 			error = EAFNOSUPPORT;
585 			goto release;
586 		}
587 		if (sin6->sin6_port == 0) {
588 			error = EADDRNOTAVAIL;
589 			goto release;
590 		}
591 
592 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
593 			error = EISCONN;
594 			goto release;
595 		}
596 
597 		/* protect *sin6 from overwrites */
598 		tmp = *sin6;
599 		sin6 = &tmp;
600 
601 		faddr = &sin6->sin6_addr;
602 		fport = sin6->sin6_port; /* allow 0 port */
603 
604 		/* KAME hack: embed scopeid */
605 		if (in6_embedscope(&sin6->sin6_addr, sin6, in6p, NULL) != 0) {
606 			error = EINVAL;
607 			goto release;
608 		}
609 
610 		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
611 			laddr = in6_selectsrc(sin6, in6p->in6p_outputopts,
612 					      in6p->in6p_moptions,
613 					      &in6p->in6p_route,
614 					      &in6p->in6p_laddr, &error);
615 		} else
616 			laddr = &in6p->in6p_laddr;	/*XXX*/
617 		if (laddr == NULL) {
618 			if (error == 0)
619 				error = EADDRNOTAVAIL;
620 			goto release;
621 		}
622 		if (in6p->in6p_lport == 0 &&
623 		    (error = in6_pcbsetport(laddr, in6p)) != 0)
624 			goto release;
625 	} else {
626 		if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
627 			error = ENOTCONN;
628 			goto release;
629 		}
630 		laddr = &in6p->in6p_laddr;
631 		faddr = &in6p->in6p_faddr;
632 		fport = in6p->in6p_fport;
633 	}
634 
635 	if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
636 		af = AF_INET6;
637 		hlen = sizeof(struct ip6_hdr);
638 	} else {
639 		af = AF_INET;
640 		hlen = sizeof(struct ip);
641 	}
642 
643 	/*
644 	 * Calculate data length and get a mbuf
645 	 * for UDP and IP6 headers.
646 	 */
647 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
648 	if (m == 0) {
649 		error = ENOBUFS;
650 		goto release;
651 	}
652 
653 	/*
654 	 * Stuff checksum and output datagram.
655 	 */
656 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
657 	udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
658 	udp6->uh_dport = fport;
659 	if (plen <= 0xffff)
660 		udp6->uh_ulen = htons((u_short)plen);
661 	else
662 		udp6->uh_ulen = 0;
663 	udp6->uh_sum = 0;
664 
665 	switch (af) {
666 	case AF_INET6:
667 		ip6 = mtod(m, struct ip6_hdr *);
668 		ip6->ip6_flow	= in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK;
669 		ip6->ip6_vfc 	&= ~IPV6_VERSION_MASK;
670 		ip6->ip6_vfc 	|= IPV6_VERSION;
671 #if 0				/* ip6_plen will be filled in ip6_output. */
672 		ip6->ip6_plen	= htons((u_short)plen);
673 #endif
674 		ip6->ip6_nxt	= IPPROTO_UDP;
675 		ip6->ip6_hlim	= in6_selecthlim(in6p,
676 						 in6p->in6p_route.ro_rt ?
677 						 in6p->in6p_route.ro_rt->rt_ifp : NULL);
678 		ip6->ip6_src	= *laddr;
679 		ip6->ip6_dst	= *faddr;
680 
681 		if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
682 				sizeof(struct ip6_hdr), plen)) == 0) {
683 			udp6->uh_sum = 0xffff;
684 		}
685 
686 		udp6stat.udp6s_opackets++;
687 #ifdef IPSEC
688 		ipsec_setsocket(m, in6p->in6p_socket);
689 #endif /*IPSEC*/
690 		error = ip6_output(m, in6p->in6p_outputopts, &in6p->in6p_route,
691 			    0, in6p->in6p_moptions, NULL);
692 		break;
693 	case AF_INET:
694 #ifdef INET
695 		/* can't transmit jumbogram over IPv4 */
696 		if (plen > 0xffff) {
697 			error = EMSGSIZE;
698 			goto release;
699 		}
700 
701 		ip = mtod(m, struct ip *);
702 
703 		ip->ip_len = plen;
704 		ip->ip_p = IPPROTO_UDP;
705 		ip->ip_ttl = in6p->in6p_hops;	/*XXX*/
706 		ip->ip_tos = 0;			/*XXX*/
707 		bcopy(&laddr->s6_addr[12], &ip->ip_src, sizeof(ip->ip_src));
708 		bcopy(&faddr->s6_addr[12], &ip->ip_dst, sizeof(ip->ip_dst));
709 
710 		udp6->uh_sum = 0;
711 		if ((udp6->uh_sum = in_cksum(m, ulen)) == 0)
712 			udp6->uh_sum = 0xffff;
713 
714 		udpstat.udps_opackets++;
715 #ifdef IPSEC
716 		ipsec_setsocket(m, NULL);	/*XXX*/
717 #endif /*IPSEC*/
718 		error = ip_output(m, NULL, &in6p->in6p_route, 0 /*XXX*/);
719 		break;
720 #else
721 		error = EAFNOSUPPORT;
722 		goto release;
723 #endif
724 	}
725 	goto releaseopt;
726 
727 release:
728 	m_freem(m);
729 
730 releaseopt:
731 	if (control) {
732 		in6p->in6p_outputopts = stickyopt;
733 		m_freem(control);
734 	}
735 	return(error);
736 }
737 
738 extern	int udp6_sendspace;
739 extern	int udp6_recvspace;
740 
741 int
742 udp6_usrreq(so, req, m, addr6, control, p)
743 	struct socket *so;
744 	int req;
745 	struct mbuf *m, *addr6, *control;
746 	struct proc *p;
747 {
748 	struct	in6pcb *in6p = sotoin6pcb(so);
749 	int	error = 0;
750 	int	s;
751 
752 	/*
753 	 * MAPPED_ADDR implementation info:
754 	 *  Mapped addr support for PRU_CONTROL is not necessary.
755 	 *  Because typical user of PRU_CONTROL is such as ifconfig,
756 	 *  and they don't associate any addr to their socket.  Then
757 	 *  socket family is only hint about the PRU_CONTROL'ed address
758 	 *  family, especially when getting addrs from kernel.
759 	 *  So AF_INET socket need to be used to control AF_INET addrs,
760 	 *  and AF_INET6 socket for AF_INET6 addrs.
761 	 */
762 	if (req == PRU_CONTROL)
763 		return(in6_control(so, (u_long)m, (caddr_t)addr6,
764 				   (struct ifnet *)control, p));
765 
766 	if (req == PRU_PURGEIF) {
767 		in6_purgeif((struct ifnet *)control);
768 		in6_pcbpurgeif(&udb6, (struct ifnet *)control);
769 		return (0);
770 	}
771 
772 	if (in6p == NULL && req != PRU_ATTACH) {
773 		error = EINVAL;
774 		goto release;
775 	}
776 
777 	switch (req) {
778 	case PRU_ATTACH:
779 		/*
780 		 * MAPPED_ADDR implementation spec:
781 		 *  Always attach for IPv6,
782 		 *  and only when necessary for IPv4.
783 		 */
784 		if (in6p != NULL) {
785 			error = EINVAL;
786 			break;
787 		}
788 		s = splsoftnet();
789 		error = in6_pcballoc(so, &udb6);
790 		splx(s);
791 		if (error)
792 			break;
793 		error = soreserve(so, udp6_sendspace, udp6_recvspace);
794 		if (error)
795 			break;
796 		in6p = sotoin6pcb(so);
797 		in6p->in6p_cksum = -1;	/* just to be sure */
798 #ifdef IPSEC
799 		error = ipsec_init_policy(so, &in6p->in6p_sp);
800 		if (error != 0) {
801 			in6_pcbdetach(in6p);
802 			break;
803 		}
804 #endif /*IPSEC*/
805 		break;
806 
807 	case PRU_DETACH:
808 		udp6_detach(in6p);
809 		break;
810 
811 	case PRU_BIND:
812 		s = splsoftnet();
813 		error = in6_pcbbind(in6p, addr6, p);
814 		splx(s);
815 		break;
816 
817 	case PRU_LISTEN:
818 		error = EOPNOTSUPP;
819 		break;
820 
821 	case PRU_CONNECT:
822 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
823 			error = EISCONN;
824 			break;
825 		}
826 		s = splsoftnet();
827 		error = in6_pcbconnect(in6p, addr6);
828 		if (ip6_auto_flowlabel) {
829 			in6p->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
830 			in6p->in6p_flowinfo |=
831 				(htonl(ip6_flow_seq++) & IPV6_FLOWLABEL_MASK);
832 		}
833 		splx(s);
834 		if (error == 0)
835 			soisconnected(so);
836 		break;
837 
838 	case PRU_CONNECT2:
839 		error = EOPNOTSUPP;
840 		break;
841 
842 	case PRU_ACCEPT:
843 		error = EOPNOTSUPP;
844 		break;
845 
846 	case PRU_DISCONNECT:
847 		if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
848 			error = ENOTCONN;
849 			break;
850 		}
851 		s = splsoftnet();
852 		in6_pcbdisconnect(in6p);
853 		bzero((caddr_t)&in6p->in6p_laddr, sizeof(in6p->in6p_laddr));
854 		splx(s);
855 		so->so_state &= ~SS_ISCONNECTED;		/* XXX */
856 		break;
857 
858 	case PRU_SHUTDOWN:
859 		socantsendmore(so);
860 		break;
861 
862 	case PRU_SEND:
863 		return(udp6_output(in6p, m, addr6, control, p));
864 
865 	case PRU_ABORT:
866 		soisdisconnected(so);
867 		udp6_detach(in6p);
868 		break;
869 
870 	case PRU_SOCKADDR:
871 		in6_setsockaddr(in6p, addr6);
872 		break;
873 
874 	case PRU_PEERADDR:
875 		in6_setpeeraddr(in6p, addr6);
876 		break;
877 
878 	case PRU_SENSE:
879 		/*
880 		 * stat: don't bother with a blocksize
881 		 */
882 		return(0);
883 
884 	case PRU_SENDOOB:
885 	case PRU_FASTTIMO:
886 	case PRU_SLOWTIMO:
887 	case PRU_PROTORCV:
888 	case PRU_PROTOSEND:
889 		error = EOPNOTSUPP;
890 		break;
891 
892 	case PRU_RCVD:
893 	case PRU_RCVOOB:
894 		return(EOPNOTSUPP);	/* do not free mbuf's */
895 
896 	default:
897 		panic("udp6_usrreq");
898 	}
899 
900 release:
901 	if (control) {
902 		printf("udp control data unexpectedly retained\n");
903 		m_freem(control);
904 	}
905 	if (m)
906 		m_freem(m);
907 	return(error);
908 }
909 
910 static void
911 udp6_detach(in6p)
912 	struct in6pcb *in6p;
913 {
914 	int s = splsoftnet();
915 
916 	if (in6p == udp6_last_in6pcb)
917 		udp6_last_in6pcb = &udb6;
918 	in6_pcbdetach(in6p);
919 	splx(s);
920 }
921 
922 #include <uvm/uvm_extern.h>
923 #include <sys/sysctl.h>
924 
925 int
926 udp6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
927 	int *name;
928 	u_int namelen;
929 	void *oldp;
930 	size_t *oldlenp;
931 	void *newp;
932 	size_t newlen;
933 {
934 	/* All sysctl names at this level are terminal. */
935 	if (namelen != 1)
936 		return ENOTDIR;
937 
938 	switch (name[0]) {
939 
940 	case UDP6CTL_SENDSPACE:
941 		return sysctl_int(oldp, oldlenp, newp, newlen,
942 		    &udp6_sendspace);
943 	case UDP6CTL_RECVSPACE:
944 		return sysctl_int(oldp, oldlenp, newp, newlen,
945 		    &udp6_recvspace);
946 	default:
947 		return ENOPROTOOPT;
948 	}
949 	/* NOTREACHED */
950 }
951