xref: /netbsd-src/sys/netinet6/udp6_usrreq.c (revision ccd9df534e375a4366c5b55f23782053c7a98d82)
1 /* $NetBSD: udp6_usrreq.c,v 1.155 2024/07/05 04:31:54 rin Exp $ */
2 /* $KAME: udp6_usrreq.c,v 1.86 2001/05/27 17:33:00 itojun Exp $ */
3 /* $KAME: udp6_output.c,v 1.43 2001/10/15 09:19:52 itojun Exp $ */
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1982, 1986, 1989, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  *
62  *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
63  */
64 
65 #include <sys/cdefs.h>
66 __KERNEL_RCSID(0, "$NetBSD: udp6_usrreq.c,v 1.155 2024/07/05 04:31:54 rin Exp $");
67 
68 #ifdef _KERNEL_OPT
69 #include "opt_inet.h"
70 #include "opt_inet_csum.h"
71 #include "opt_ipsec.h"
72 #include "opt_net_mpsafe.h"
73 #endif
74 
75 #include <sys/param.h>
76 #include <sys/mbuf.h>
77 #include <sys/protosw.h>
78 #include <sys/socket.h>
79 #include <sys/socketvar.h>
80 #include <sys/systm.h>
81 #include <sys/proc.h>
82 #include <sys/syslog.h>
83 #include <sys/domain.h>
84 #include <sys/sysctl.h>
85 
86 #include <net/if.h>
87 #include <net/if_types.h>
88 
89 #include <netinet/in.h>
90 #include <netinet/in_var.h>
91 #include <netinet/in_systm.h>
92 #include <netinet/in_offload.h>
93 #include <netinet/ip.h>
94 #include <netinet/ip_var.h>
95 #include <netinet/in_pcb.h>
96 #include <netinet/udp.h>
97 #include <netinet/udp_var.h>
98 #include <netinet/udp_private.h>
99 
100 #include <netinet/ip6.h>
101 #include <netinet/icmp6.h>
102 #include <netinet6/ip6_var.h>
103 #include <netinet6/ip6_private.h>
104 #include <netinet6/in6_pcb.h>
105 #include <netinet6/udp6_var.h>
106 #include <netinet6/udp6_private.h>
107 #include <netinet6/ip6protosw.h>
108 #include <netinet6/scope6_var.h>
109 
110 #ifdef IPSEC
111 #include <netipsec/ipsec.h>
112 #include <netipsec/esp.h>
113 #ifdef INET6
114 #include <netipsec/ipsec6.h>
115 #endif
116 #endif
117 
118 #include "faith.h"
119 #if defined(NFAITH) && NFAITH > 0
120 #include <net/if_faith.h>
121 #endif
122 
123 /*
124  * UDP protocol implementation.
125  * Per RFC 768, August, 1980.
126  */
127 
128 extern struct inpcbtable udbtable;
129 
130 percpu_t *udp6stat_percpu;
131 
132 /* UDP on IP6 parameters */
133 static int udp6_sendspace = 9216;	/* really max datagram size */
134 static int udp6_recvspace = 40 * (1024 + sizeof(struct sockaddr_in6));
135 					/* 40 1K datagrams */
136 
137 static void udp6_notify(struct inpcb *, int);
138 static void sysctl_net_inet6_udp6_setup(struct sysctllog **);
139 #ifdef IPSEC
140 static int udp6_espinudp(struct mbuf **, int);
141 #endif
142 
143 #ifdef UDP_CSUM_COUNTERS
144 #include <sys/device.h>
145 struct evcnt udp6_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
146     NULL, "udp6", "hwcsum bad");
147 struct evcnt udp6_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
148     NULL, "udp6", "hwcsum ok");
149 struct evcnt udp6_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
150     NULL, "udp6", "hwcsum data");
151 struct evcnt udp6_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
152     NULL, "udp6", "swcsum");
153 
154 EVCNT_ATTACH_STATIC(udp6_hwcsum_bad);
155 EVCNT_ATTACH_STATIC(udp6_hwcsum_ok);
156 EVCNT_ATTACH_STATIC(udp6_hwcsum_data);
157 EVCNT_ATTACH_STATIC(udp6_swcsum);
158 
159 #define	UDP_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
160 #else
161 #define	UDP_CSUM_COUNTER_INCR(ev)	/* nothing */
162 #endif
163 
164 void
165 udp6_init(void)
166 {
167 	sysctl_net_inet6_udp6_setup(NULL);
168 	udp6stat_percpu = percpu_alloc(sizeof(uint64_t) * UDP6_NSTATS);
169 
170 	udp_init_common();
171 }
172 
173 /*
174  * Notify a udp user of an asynchronous error;
175  * just wake up so that he can collect error status.
176  */
177 static	void
178 udp6_notify(struct inpcb *inp, int errno)
179 {
180 	inp->inp_socket->so_error = errno;
181 	sorwakeup(inp->inp_socket);
182 	sowwakeup(inp->inp_socket);
183 }
184 
185 void *
186 udp6_ctlinput(int cmd, const struct sockaddr *sa, void *d)
187 {
188 	struct udphdr uh;
189 	struct ip6_hdr *ip6;
190 	const struct sockaddr_in6 *sa6 = (const struct sockaddr_in6 *)sa;
191 	struct mbuf *m;
192 	int off;
193 	void *cmdarg;
194 	struct ip6ctlparam *ip6cp = NULL;
195 	const struct sockaddr_in6 *sa6_src = NULL;
196 	void (*notify)(struct inpcb *, int) = udp6_notify;
197 	struct udp_portonly {
198 		u_int16_t uh_sport;
199 		u_int16_t uh_dport;
200 	} *uhp;
201 
202 	if (sa->sa_family != AF_INET6 ||
203 	    sa->sa_len != sizeof(struct sockaddr_in6))
204 		return NULL;
205 
206 	if ((unsigned)cmd >= PRC_NCMDS)
207 		return NULL;
208 	if (PRC_IS_REDIRECT(cmd))
209 		notify = in6pcb_rtchange, d = NULL;
210 	else if (cmd == PRC_HOSTDEAD)
211 		d = NULL;
212 	else if (cmd == PRC_MSGSIZE) {
213 		/* special code is present, see below */
214 		notify = in6pcb_rtchange;
215 	}
216 	else if (inet6ctlerrmap[cmd] == 0)
217 		return NULL;
218 
219 	/* if the parameter is from icmp6, decode it. */
220 	if (d != NULL) {
221 		ip6cp = (struct ip6ctlparam *)d;
222 		m = ip6cp->ip6c_m;
223 		ip6 = ip6cp->ip6c_ip6;
224 		off = ip6cp->ip6c_off;
225 		cmdarg = ip6cp->ip6c_cmdarg;
226 		sa6_src = ip6cp->ip6c_src;
227 	} else {
228 		m = NULL;
229 		ip6 = NULL;
230 		cmdarg = NULL;
231 		sa6_src = &sa6_any;
232 		off = 0;
233 	}
234 
235 	if (ip6) {
236 		/* check if we can safely examine src and dst ports */
237 		if (m->m_pkthdr.len < off + sizeof(*uhp)) {
238 			if (cmd == PRC_MSGSIZE)
239 				icmp6_mtudisc_update((struct ip6ctlparam *)d, 0);
240 			return NULL;
241 		}
242 
243 		memset(&uh, 0, sizeof(uh));
244 		m_copydata(m, off, sizeof(*uhp), (void *)&uh);
245 
246 		if (cmd == PRC_MSGSIZE) {
247 			int valid = 0;
248 
249 			/*
250 			 * Check to see if we have a valid UDP socket
251 			 * corresponding to the address in the ICMPv6 message
252 			 * payload.
253 			 */
254 			if (in6pcb_lookup(&udbtable, &sa6->sin6_addr,
255 			    uh.uh_dport, (const struct in6_addr *)&sa6_src->sin6_addr,
256 			    uh.uh_sport, 0, 0))
257 				valid++;
258 #if 0
259 			/*
260 			 * As the use of sendto(2) is fairly popular,
261 			 * we may want to allow non-connected pcb too.
262 			 * But it could be too weak against attacks...
263 			 * We should at least check if the local address (= s)
264 			 * is really ours.
265 			 */
266 			else if (in6pcb_lookup_bound(&udbtable, &sa6->sin6_addr,
267 			    uh.uh_dport, 0))
268 				valid++;
269 #endif
270 
271 			/*
272 			 * Depending on the value of "valid" and routing table
273 			 * size (mtudisc_{hi,lo}wat), we will:
274 			 * - recalculate the new MTU and create the
275 			 *   corresponding routing entry, or
276 			 * - ignore the MTU change notification.
277 			 */
278 			icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
279 
280 			/*
281 			 * regardless of if we called
282 			 * icmp6_mtudisc_update(), we need to call
283 			 * in6pcb_notify(), to notify path MTU change
284 			 * to the userland (RFC3542), because some
285 			 * unconnected sockets may share the same
286 			 * destination and want to know the path MTU.
287 			 */
288 		}
289 
290 		(void)in6pcb_notify(&udbtable, sa, uh.uh_dport,
291 		    sin6tocsa(sa6_src), uh.uh_sport, cmd, cmdarg,
292 		    notify);
293 	} else {
294 		(void)in6pcb_notify(&udbtable, sa, 0,
295 		    sin6tocsa(sa6_src), 0, cmd, cmdarg, notify);
296 	}
297 	return NULL;
298 }
299 
300 int
301 udp6_ctloutput(int op, struct socket *so, struct sockopt *sopt)
302 {
303 	int s;
304 	int error = 0;
305 	struct inpcb *inp;
306 	int family;
307 	int optval;
308 
309 	family = so->so_proto->pr_domain->dom_family;
310 
311 	s = splsoftnet();
312 	switch (family) {
313 #ifdef INET
314 	case PF_INET:
315 		if (sopt->sopt_level != IPPROTO_UDP) {
316 			error = ip_ctloutput(op, so, sopt);
317 			goto end;
318 		}
319 		break;
320 #endif
321 #ifdef INET6
322 	case PF_INET6:
323 		if (sopt->sopt_level != IPPROTO_UDP) {
324 			error = ip6_ctloutput(op, so, sopt);
325 			goto end;
326 		}
327 		break;
328 #endif
329 	default:
330 		error = EAFNOSUPPORT;
331 		goto end;
332 	}
333 
334 	switch (op) {
335 	case PRCO_SETOPT:
336 		inp = sotoinpcb(so);
337 
338 		switch (sopt->sopt_name) {
339 		case UDP_ENCAP:
340 			error = sockopt_getint(sopt, &optval);
341 			if (error)
342 				break;
343 
344 			switch(optval) {
345 			case 0:
346 				inp->inp_flags &= ~IN6P_ESPINUDP;
347 				break;
348 
349 			case UDP_ENCAP_ESPINUDP:
350 				inp->inp_flags |= IN6P_ESPINUDP;
351 				break;
352 
353 			default:
354 				error = EINVAL;
355 				break;
356 			}
357 			break;
358 
359 		default:
360 			error = ENOPROTOOPT;
361 			break;
362 		}
363 		break;
364 
365 	default:
366 		error = EINVAL;
367 		break;
368 	}
369 
370 end:
371 	splx(s);
372 	return error;
373 }
374 
375 static void
376 udp6_sendup(struct mbuf *m, int off /* offset of data portion */,
377     struct sockaddr *src, struct socket *so)
378 {
379 	struct mbuf *opts = NULL;
380 	struct mbuf *n;
381 	struct inpcb *inp;
382 
383 	KASSERT(so != NULL);
384 	KASSERT(so->so_proto->pr_domain->dom_family == AF_INET6);
385 	inp = sotoinpcb(so);
386 	KASSERT(inp != NULL);
387 
388 #if defined(IPSEC)
389 	if (ipsec_used && ipsec_in_reject(m, inp)) {
390 		if ((n = m_copypacket(m, M_DONTWAIT)) != NULL)
391 			icmp6_error(n, ICMP6_DST_UNREACH,
392 			    ICMP6_DST_UNREACH_ADMIN, 0);
393 		return;
394 	}
395 #endif
396 
397 	if ((n = m_copypacket(m, M_DONTWAIT)) != NULL) {
398 		if (inp->inp_flags & IN6P_CONTROLOPTS ||
399 		    SOOPT_TIMESTAMP(inp->inp_socket->so_options)) {
400 			struct ip6_hdr *ip6 = mtod(n, struct ip6_hdr *);
401 			ip6_savecontrol(inp, &opts, ip6, n);
402 		}
403 
404 		m_adj(n, off);
405 		if (sbappendaddr(&so->so_rcv, src, n, opts) == 0) {
406 			m_freem(n);
407 			m_freem(opts);
408 			UDP6_STATINC(UDP6_STAT_FULLSOCK);
409 			soroverflow(so);
410 		} else
411 			sorwakeup(so);
412 	}
413 }
414 
415 int
416 udp6_realinput(int af, struct sockaddr_in6 *src, struct sockaddr_in6 *dst,
417     struct mbuf **mp, int off)
418 {
419 	u_int16_t sport, dport;
420 	int rcvcnt;
421 	struct in6_addr src6, *dst6;
422 	const struct in_addr *dst4;
423 	struct inpcb *inp;
424 	struct mbuf *m = *mp;
425 
426 	rcvcnt = 0;
427 	off += sizeof(struct udphdr);	/* now, offset of payload */
428 
429 	if (af != AF_INET && af != AF_INET6)
430 		goto bad;
431 	if (src->sin6_family != AF_INET6 || dst->sin6_family != AF_INET6)
432 		goto bad;
433 
434 	src6 = src->sin6_addr;
435 	if (sa6_recoverscope(src) != 0) {
436 		/* XXX: should be impossible. */
437 		goto bad;
438 	}
439 	sport = src->sin6_port;
440 
441 	dport = dst->sin6_port;
442 	dst4 = (struct in_addr *)&dst->sin6_addr.s6_addr[12];
443 	dst6 = &dst->sin6_addr;
444 
445 	if (IN6_IS_ADDR_MULTICAST(dst6) ||
446 	    (af == AF_INET && IN_MULTICAST(dst4->s_addr))) {
447 		/*
448 		 * Deliver a multicast or broadcast datagram to *all* sockets
449 		 * for which the local and remote addresses and ports match
450 		 * those of the incoming datagram.  This allows more than
451 		 * one process to receive multi/broadcasts on the same port.
452 		 * (This really ought to be done for unicast datagrams as
453 		 * well, but that would cause problems with existing
454 		 * applications that open both address-specific sockets and
455 		 * a wildcard socket listening to the same port -- they would
456 		 * end up receiving duplicates of every unicast datagram.
457 		 * Those applications open the multiple sockets to overcome an
458 		 * inadequacy of the UDP socket interface, but for backwards
459 		 * compatibility we avoid the problem here rather than
460 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
461 		 */
462 
463 		/*
464 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
465 		 * we need udpiphdr for IPsec processing so we do that later.
466 		 */
467 		/*
468 		 * Locate pcb(s) for datagram.
469 		 */
470 		TAILQ_FOREACH(inp, &udbtable.inpt_queue, inp_queue) {
471 			if (inp->inp_af != AF_INET6)
472 				continue;
473 
474 			if (inp->inp_lport != dport)
475 				continue;
476 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp))) {
477 				if (!IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp),
478 				    dst6))
479 					continue;
480 			} else {
481 				if (IN6_IS_ADDR_V4MAPPED(dst6) &&
482 				    (inp->inp_flags & IN6P_IPV6_V6ONLY))
483 					continue;
484 			}
485 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp))) {
486 				if (!IN6_ARE_ADDR_EQUAL(&in6p_faddr(inp),
487 				    &src6) || inp->inp_fport != sport)
488 					continue;
489 			} else {
490 				if (IN6_IS_ADDR_V4MAPPED(&src6) &&
491 				    (inp->inp_flags & IN6P_IPV6_V6ONLY))
492 					continue;
493 			}
494 
495 			udp6_sendup(m, off, sin6tosa(src), inp->inp_socket);
496 			rcvcnt++;
497 
498 			/*
499 			 * Don't look for additional matches if this one does
500 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
501 			 * socket options set.  This heuristic avoids searching
502 			 * through all pcbs in the common case of a non-shared
503 			 * port.  It assumes that an application will never
504 			 * clear these options after setting them.
505 			 */
506 			if ((inp->inp_socket->so_options &
507 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
508 				break;
509 		}
510 	} else {
511 		/*
512 		 * Locate pcb for datagram.
513 		 */
514 		inp = in6pcb_lookup(&udbtable, &src6, sport, dst6,
515 					     dport, 0, 0);
516 		if (inp == NULL) {
517 			UDP_STATINC(UDP_STAT_PCBHASHMISS);
518 			inp = in6pcb_lookup_bound(&udbtable, dst6, dport, 0);
519 			if (inp == NULL)
520 				return rcvcnt;
521 		}
522 
523 #ifdef IPSEC
524 		/* Handle ESP over UDP */
525 		if (inp->inp_flags & IN6P_ESPINUDP) {
526 			switch (udp6_espinudp(mp, off)) {
527 			case -1: /* Error, m was freed */
528 				rcvcnt = -1;
529 				goto bad;
530 
531 			case 1: /* ESP over UDP */
532 				rcvcnt++;
533 				goto bad;
534 
535 			case 0: /* plain UDP */
536 			default: /* Unexpected */
537 				/*
538 				 * Normal UDP processing will take place,
539 				 * m may have changed.
540 				 */
541 				m = *mp;
542 				break;
543 			}
544 		}
545 #endif
546 
547 		if (inp->inp_overudp_cb != NULL) {
548 			int ret;
549 			ret = inp->inp_overudp_cb(mp, off, inp->inp_socket,
550 			    sin6tosa(src), inp->inp_overudp_arg);
551 			switch (ret) {
552 			case -1: /* Error, m was freed */
553 				rcvcnt = -1;
554 				goto bad;
555 
556 			case 1: /* Foo over UDP */
557 				KASSERT(*mp == NULL);
558 				rcvcnt++;
559 				goto bad;
560 
561 			case 0: /* plain UDP */
562 			default: /* Unexpected */
563 				/*
564 				 * Normal UDP processing will take place,
565 				 * m may have changed.
566 				 */
567 				break;
568 			}
569 		}
570 
571 		udp6_sendup(m, off, sin6tosa(src), inp->inp_socket);
572 		rcvcnt++;
573 	}
574 
575 bad:
576 	return rcvcnt;
577 }
578 
579 int
580 udp6_input_checksum(struct mbuf *m, const struct udphdr *uh, int off, int len)
581 {
582 
583 	/*
584 	 * XXX it's better to record and check if this mbuf is
585 	 * already checked.
586 	 */
587 
588 	if (__predict_false((m->m_flags & M_LOOP) && !udp_do_loopback_cksum)) {
589 		goto good;
590 	}
591 	if (uh->uh_sum == 0) {
592 		UDP6_STATINC(UDP6_STAT_NOSUM);
593 		goto bad;
594 	}
595 
596 	switch (m->m_pkthdr.csum_flags &
597 	    ((m_get_rcvif_NOMPSAFE(m)->if_csum_flags_rx & M_CSUM_UDPv6) |
598 	    M_CSUM_TCP_UDP_BAD | M_CSUM_DATA)) {
599 	case M_CSUM_UDPv6|M_CSUM_TCP_UDP_BAD:
600 		UDP_CSUM_COUNTER_INCR(&udp6_hwcsum_bad);
601 		UDP6_STATINC(UDP6_STAT_BADSUM);
602 		goto bad;
603 
604 #if 0 /* notyet */
605 	case M_CSUM_UDPv6|M_CSUM_DATA:
606 #endif
607 
608 	case M_CSUM_UDPv6:
609 		/* Checksum was okay. */
610 		UDP_CSUM_COUNTER_INCR(&udp6_hwcsum_ok);
611 		break;
612 
613 	default:
614 		/*
615 		 * Need to compute it ourselves.  Maybe skip checksum
616 		 * on loopback interfaces.
617 		 */
618 		UDP_CSUM_COUNTER_INCR(&udp6_swcsum);
619 		if (in6_cksum(m, IPPROTO_UDP, off, len) != 0) {
620 			UDP6_STATINC(UDP6_STAT_BADSUM);
621 			goto bad;
622 		}
623 	}
624 
625 good:
626 	return 0;
627 bad:
628 	return -1;
629 }
630 
631 int
632 udp6_input(struct mbuf **mp, int *offp, int proto)
633 {
634 	struct mbuf *m = *mp;
635 	int off = *offp;
636 	struct sockaddr_in6 src, dst;
637 	struct ip6_hdr *ip6;
638 	struct udphdr *uh;
639 	u_int32_t plen, ulen;
640 
641 	ip6 = mtod(m, struct ip6_hdr *);
642 
643 #if defined(NFAITH) && 0 < NFAITH
644 	if (faithprefix(&ip6->ip6_dst)) {
645 		/* send icmp6 host unreach? */
646 		m_freem(m);
647 		return IPPROTO_DONE;
648 	}
649 #endif
650 
651 	UDP6_STATINC(UDP6_STAT_IPACKETS);
652 
653 	/* Check for jumbogram is done in ip6_input. We can trust pkthdr.len. */
654 	plen = m->m_pkthdr.len - off;
655 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(struct udphdr));
656 	if (uh == NULL) {
657 		IP6_STATINC(IP6_STAT_TOOSHORT);
658 		return IPPROTO_DONE;
659 	}
660 
661 	/*
662 	 * Enforce alignment requirements that are violated in
663 	 * some cases, see kern/50766 for details.
664 	 */
665 	if (ACCESSIBLE_POINTER(uh, struct udphdr) == 0) {
666 		m = m_copyup(m, off + sizeof(struct udphdr), 0);
667 		if (m == NULL) {
668 			IP6_STATINC(IP6_STAT_TOOSHORT);
669 			return IPPROTO_DONE;
670 		}
671 		ip6 = mtod(m, struct ip6_hdr *);
672 		uh = (struct udphdr *)(mtod(m, char *) + off);
673 	}
674 	KASSERT(ACCESSIBLE_POINTER(uh, struct udphdr));
675 	ulen = ntohs((u_short)uh->uh_ulen);
676 
677 	/*
678 	 * RFC2675 section 4: jumbograms will have 0 in the UDP header field,
679 	 * iff payload length > 0xffff.
680 	 */
681 	if (ulen == 0 && plen > 0xffff)
682 		ulen = plen;
683 
684 	if (plen != ulen) {
685 		UDP6_STATINC(UDP6_STAT_BADLEN);
686 		goto bad;
687 	}
688 
689 	/* destination port of 0 is illegal, based on RFC768. */
690 	if (uh->uh_dport == 0)
691 		goto bad;
692 
693 	/*
694 	 * Checksum extended UDP header and data.  Maybe skip checksum
695 	 * on loopback interfaces.
696 	 */
697 	if (udp6_input_checksum(m, uh, off, ulen))
698 		goto bad;
699 
700 	/*
701 	 * Construct source and dst sockaddrs.
702 	 */
703 	memset(&src, 0, sizeof(src));
704 	src.sin6_family = AF_INET6;
705 	src.sin6_len = sizeof(struct sockaddr_in6);
706 	src.sin6_addr = ip6->ip6_src;
707 	src.sin6_port = uh->uh_sport;
708 	memset(&dst, 0, sizeof(dst));
709 	dst.sin6_family = AF_INET6;
710 	dst.sin6_len = sizeof(struct sockaddr_in6);
711 	dst.sin6_addr = ip6->ip6_dst;
712 	dst.sin6_port = uh->uh_dport;
713 
714 	if (udp6_realinput(AF_INET6, &src, &dst, &m, off) == 0) {
715 		if (m->m_flags & M_MCAST) {
716 			UDP6_STATINC(UDP6_STAT_NOPORTMCAST);
717 			goto bad;
718 		}
719 		UDP6_STATINC(UDP6_STAT_NOPORT);
720 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
721 		m = NULL;
722 	}
723 
724 bad:
725 	m_freem(m);
726 	return IPPROTO_DONE;
727 }
728 
729 int
730 udp6_output(struct inpcb * const inp, struct mbuf *m,
731     struct sockaddr_in6 * const addr6, struct mbuf * const control,
732     struct lwp * const l)
733 {
734 	u_int32_t ulen = m->m_pkthdr.len;
735 	u_int32_t plen = sizeof(struct udphdr) + ulen;
736 	struct ip6_hdr *ip6;
737 	struct udphdr *udp6;
738 	struct in6_addr _laddr, *laddr, *faddr;
739 	struct in6_addr laddr_mapped; /* XXX ugly */
740 	struct sockaddr_in6 *sin6 = NULL;
741 	struct ifnet *oifp = NULL;
742 	int scope_ambiguous = 0;
743 	u_int16_t fport;
744 	int error = 0;
745 	struct ip6_pktopts *optp = NULL;
746 	struct ip6_pktopts opt;
747 	int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
748 #ifdef INET
749 	struct ip *ip;
750 	struct udpiphdr *ui;
751 	int flags = 0;
752 #endif
753 	struct sockaddr_in6 tmp;
754 
755 	if (addr6) {
756 		sin6 = addr6;
757 		if (sin6->sin6_len != sizeof(*sin6)) {
758 			error = EINVAL;
759 			goto release;
760 		}
761 		if (sin6->sin6_family != AF_INET6) {
762 			error = EAFNOSUPPORT;
763 			goto release;
764 		}
765 
766 		/* protect *sin6 from overwrites */
767 		tmp = *sin6;
768 		sin6 = &tmp;
769 
770 		/*
771 		 * Application should provide a proper zone ID or the use of
772 		 * default zone IDs should be enabled.  Unfortunately, some
773 		 * applications do not behave as it should, so we need a
774 		 * workaround.  Even if an appropriate ID is not determined,
775 		 * we'll see if we can determine the outgoing interface.  If we
776 		 * can, determine the zone ID based on the interface below.
777 		 */
778 		if (sin6->sin6_scope_id == 0 && !ip6_use_defzone)
779 			scope_ambiguous = 1;
780 		if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
781 			goto release;
782 	}
783 
784 	if (control) {
785 		if (__predict_false(l == NULL)) {
786 			panic("%s: control but no lwp", __func__);
787 		}
788 		if ((error = ip6_setpktopts(control, &opt,
789 		    in6p_outputopts(inp), l->l_cred, IPPROTO_UDP)) != 0)
790 			goto release;
791 		optp = &opt;
792 	} else
793 		optp = in6p_outputopts(inp);
794 
795 
796 	if (sin6) {
797 		/*
798 		 * Slightly different than v4 version in that we call
799 		 * in6_selectsrc and in6pcb_set_port to fill in the local
800 		 * address and port rather than inpcb_connect. inpcb_connect
801 		 * sets inp_faddr which causes EISCONN below to be hit on
802 		 * subsequent sendto.
803 		 */
804 		if (sin6->sin6_port == 0) {
805 			error = EADDRNOTAVAIL;
806 			goto release;
807 		}
808 
809 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp))) {
810 			/* how about ::ffff:0.0.0.0 case? */
811 			error = EISCONN;
812 			goto release;
813 		}
814 
815 		faddr = &sin6->sin6_addr;
816 		fport = sin6->sin6_port; /* allow 0 port */
817 
818 		if (IN6_IS_ADDR_V4MAPPED(faddr)) {
819 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
820 				/*
821 				 * I believe we should explicitly discard the
822 				 * packet when mapped addresses are disabled,
823 				 * rather than send the packet as an IPv6 one.
824 				 * If we chose the latter approach, the packet
825 				 * might be sent out on the wire based on the
826 				 * default route, the situation which we'd
827 				 * probably want to avoid.
828 				 * (20010421 jinmei@kame.net)
829 				 */
830 				error = EINVAL;
831 				goto release;
832 			}
833 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp)) &&
834 			    !IN6_IS_ADDR_V4MAPPED(&in6p_laddr(inp))) {
835 				/*
836 				 * when remote addr is an IPv4-mapped address,
837 				 * local addr should not be an IPv6 address,
838 				 * since you cannot determine how to map IPv6
839 				 * source address to IPv4.
840 				 */
841 				error = EINVAL;
842 				goto release;
843 			}
844 
845 			af = AF_INET;
846 		}
847 
848 		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
849 			struct psref psref;
850 			int bound = curlwp_bind();
851 
852 			error = in6_selectsrc(sin6, optp,
853 			    in6p_moptions(inp),
854 			    &inp->inp_route,
855 			    &in6p_laddr(inp), &oifp, &psref, &_laddr);
856 			if (error)
857 				laddr = NULL;
858 			else
859 				laddr = &_laddr;
860 			if (oifp && scope_ambiguous &&
861 			    (error = in6_setscope(&sin6->sin6_addr,
862 			    oifp, NULL))) {
863 				if_put(oifp, &psref);
864 				curlwp_bindx(bound);
865 				goto release;
866 			}
867 			if_put(oifp, &psref);
868 			curlwp_bindx(bound);
869 		} else {
870 			/*
871 			 * XXX: freebsd[34] does not have in_selectsrc, but
872 			 * we can omit the whole part because freebsd4 calls
873 			 * udp_output() directly in this case, and thus we'll
874 			 * never see this path.
875 			 */
876 			if (IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp))) {
877 				struct sockaddr_in sin_dst;
878 				struct in_addr ina;
879 				struct in_ifaddr *ia4;
880 				struct psref _psref;
881 				int bound;
882 
883 				memcpy(&ina, &faddr->s6_addr[12], sizeof(ina));
884 				sockaddr_in_init(&sin_dst, &ina, 0);
885 				bound = curlwp_bind();
886 				ia4 = in_selectsrc(&sin_dst, &inp->inp_route,
887 				    inp->inp_socket->so_options, NULL,
888 				    &error, &_psref);
889 				if (ia4 == NULL) {
890 					curlwp_bindx(bound);
891 					if (error == 0)
892 						error = EADDRNOTAVAIL;
893 					goto release;
894 				}
895 				memset(&laddr_mapped, 0, sizeof(laddr_mapped));
896 				laddr_mapped.s6_addr16[5] = 0xffff; /* ugly */
897 				memcpy(&laddr_mapped.s6_addr[12],
898 				      &IA_SIN(ia4)->sin_addr,
899 				      sizeof(IA_SIN(ia4)->sin_addr));
900 				ia4_release(ia4, &_psref);
901 				curlwp_bindx(bound);
902 				laddr = &laddr_mapped;
903 			} else
904 			{
905 				laddr = &in6p_laddr(inp);	/* XXX */
906 			}
907 		}
908 		if (laddr == NULL) {
909 			if (error == 0)
910 				error = EADDRNOTAVAIL;
911 			goto release;
912 		}
913 		if (inp->inp_lport == 0) {
914 			/*
915 			 * Craft a sockaddr_in6 for the local endpoint. Use the
916 			 * "any" as a base, set the address, and recover the
917 			 * scope.
918 			 */
919 			struct sockaddr_in6 lsin6 =
920 			    *((const struct sockaddr_in6 *)inp->inp_socket->so_proto->pr_domain->dom_sa_any);
921 			lsin6.sin6_addr = *laddr;
922 			error = sa6_recoverscope(&lsin6);
923 			if (error)
924 				goto release;
925 
926 			error = in6pcb_set_port(&lsin6, inp, l);
927 
928 			if (error) {
929 				in6p_laddr(inp) = in6addr_any;
930 				goto release;
931 			}
932 		}
933 	} else {
934 		if (IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp))) {
935 			error = ENOTCONN;
936 			goto release;
937 		}
938 		if (IN6_IS_ADDR_V4MAPPED(&in6p_faddr(inp))) {
939 			if ((inp->inp_flags & IN6P_IPV6_V6ONLY))
940 			{
941 				/*
942 				 * XXX: this case would happen when the
943 				 * application sets the V6ONLY flag after
944 				 * connecting the foreign address.
945 				 * Such applications should be fixed,
946 				 * so we bark here.
947 				 */
948 				log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
949 				    "option was set for a connected socket\n");
950 				error = EINVAL;
951 				goto release;
952 			} else
953 				af = AF_INET;
954 		}
955 		laddr = &in6p_laddr(inp);
956 		faddr = &in6p_faddr(inp);
957 		fport = inp->inp_fport;
958 	}
959 
960 	if (af == AF_INET)
961 		hlen = sizeof(struct ip);
962 
963 	/*
964 	 * Calculate data length and get a mbuf
965 	 * for UDP and IP6 headers.
966 	 */
967 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
968 	if (m == NULL) {
969 		error = ENOBUFS;
970 		goto release;
971 	}
972 
973 	/*
974 	 * Stuff checksum and output datagram.
975 	 */
976 	udp6 = (struct udphdr *)(mtod(m, char *) + hlen);
977 	udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
978 	udp6->uh_dport = fport;
979 	if (plen <= 0xffff)
980 		udp6->uh_ulen = htons((u_int16_t)plen);
981 	else
982 		udp6->uh_ulen = 0;
983 	udp6->uh_sum = 0;
984 
985 	switch (af) {
986 	case AF_INET6:
987 		ip6 = mtod(m, struct ip6_hdr *);
988 		ip6->ip6_flow	= in6p_flowinfo(inp) & IPV6_FLOWINFO_MASK;
989 		ip6->ip6_vfc 	&= ~IPV6_VERSION_MASK;
990 		ip6->ip6_vfc 	|= IPV6_VERSION;
991 #if 0		/* ip6_plen will be filled in ip6_output. */
992 		ip6->ip6_plen	= htons((u_int16_t)plen);
993 #endif
994 		ip6->ip6_nxt	= IPPROTO_UDP;
995 		ip6->ip6_hlim	= in6pcb_selecthlim_rt(inp);
996 		ip6->ip6_src	= *laddr;
997 		ip6->ip6_dst	= *faddr;
998 
999 		udp6->uh_sum = in6_cksum_phdr(laddr, faddr,
1000 		    htonl(plen), htonl(IPPROTO_UDP));
1001 		m->m_pkthdr.csum_flags = M_CSUM_UDPv6;
1002 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1003 
1004 		UDP6_STATINC(UDP6_STAT_OPACKETS);
1005 		error = ip6_output(m, optp, &inp->inp_route, 0,
1006 		    in6p_moptions(inp), inp, NULL);
1007 		break;
1008 	case AF_INET:
1009 #ifdef INET
1010 		/* can't transmit jumbogram over IPv4 */
1011 		if (plen > 0xffff) {
1012 			error = EMSGSIZE;
1013 			goto release;
1014 		}
1015 
1016 		ip = mtod(m, struct ip *);
1017 		ui = (struct udpiphdr *)ip;
1018 		memset(ui->ui_x1, 0, sizeof(ui->ui_x1));
1019 		ui->ui_pr = IPPROTO_UDP;
1020 		ui->ui_len = htons(plen);
1021 		memcpy(&ui->ui_src, &laddr->s6_addr[12], sizeof(ui->ui_src));
1022 		ui->ui_ulen = ui->ui_len;
1023 
1024 		flags = (inp->inp_socket->so_options &
1025 			 (SO_DONTROUTE | SO_BROADCAST));
1026 		memcpy(&ui->ui_dst, &faddr->s6_addr[12], sizeof(ui->ui_dst));
1027 
1028 		udp6->uh_sum = in_cksum(m, hlen + plen);
1029 		if (udp6->uh_sum == 0)
1030 			udp6->uh_sum = 0xffff;
1031 
1032 		ip->ip_len = htons(hlen + plen);
1033 		ip->ip_ttl = in6pcb_selecthlim(inp, NULL); /* XXX */
1034 		ip->ip_tos = 0;	/* XXX */
1035 
1036 		UDP_STATINC(UDP_STAT_OPACKETS);
1037 		error = ip_output(m, NULL, &inp->inp_route, flags /* XXX */,
1038 		    inp->inp_moptions, NULL);
1039 		break;
1040 #else
1041 		error = EAFNOSUPPORT;
1042 		goto release;
1043 #endif
1044 	}
1045 	goto releaseopt;
1046 
1047 release:
1048 	m_freem(m);
1049 
1050 releaseopt:
1051 	if (control) {
1052 		if (optp == &opt)
1053 			ip6_clearpktopts(&opt, -1);
1054 		m_freem(control);
1055 	}
1056 	return (error);
1057 }
1058 
1059 static int
1060 udp6_attach(struct socket *so, int proto)
1061 {
1062 	struct inpcb *inp;
1063 	int s, error;
1064 
1065 	KASSERT(sotoinpcb(so) == NULL);
1066 	sosetlock(so);
1067 
1068 	error = soreserve(so, udp6_sendspace, udp6_recvspace);
1069 	if (error) {
1070 		return error;
1071 	}
1072 
1073 	/*
1074 	 * MAPPED_ADDR implementation spec:
1075 	 *  Always attach for IPv6, and only when necessary for IPv4.
1076 	 */
1077 	s = splsoftnet();
1078 	error = inpcb_create(so, &udbtable);
1079 	splx(s);
1080 	if (error) {
1081 		return error;
1082 	}
1083 
1084 	inp = sotoinpcb(so);
1085 	in6p_cksum(inp) = -1;	/* just to be sure */
1086 
1087 	KASSERT(solocked(so));
1088 	return 0;
1089 }
1090 
1091 static void
1092 udp6_detach(struct socket *so)
1093 {
1094 	struct inpcb *inp = sotoinpcb(so);
1095 	int s;
1096 
1097 	KASSERT(solocked(so));
1098 	KASSERT(inp != NULL);
1099 
1100 	s = splsoftnet();
1101 	inpcb_destroy(inp);
1102 	splx(s);
1103 }
1104 
1105 static int
1106 udp6_accept(struct socket *so, struct sockaddr *nam)
1107 {
1108 	KASSERT(solocked(so));
1109 
1110 	return EOPNOTSUPP;
1111 }
1112 
1113 static int
1114 udp6_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
1115 {
1116 	struct inpcb *inp = sotoinpcb(so);
1117 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
1118 	int error = 0;
1119 	int s;
1120 
1121 	KASSERT(solocked(so));
1122 	KASSERT(inp != NULL);
1123 
1124 	s = splsoftnet();
1125 	error = in6pcb_bind(inp, sin6, l);
1126 	splx(s);
1127 	return error;
1128 }
1129 
1130 static int
1131 udp6_listen(struct socket *so, struct lwp *l)
1132 {
1133 	KASSERT(solocked(so));
1134 
1135 	return EOPNOTSUPP;
1136 }
1137 
1138 static int
1139 udp6_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
1140 {
1141 	struct inpcb *inp = sotoinpcb(so);
1142 	int error = 0;
1143 	int s;
1144 
1145 	KASSERT(solocked(so));
1146 	KASSERT(inp != NULL);
1147 
1148 	if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp)))
1149 		return EISCONN;
1150 	s = splsoftnet();
1151 	error = in6pcb_connect(inp, (struct sockaddr_in6 *)nam, l);
1152 	splx(s);
1153 	if (error == 0)
1154 		soisconnected(so);
1155 
1156 	return error;
1157 }
1158 
1159 static int
1160 udp6_connect2(struct socket *so, struct socket *so2)
1161 {
1162 	KASSERT(solocked(so));
1163 
1164 	return EOPNOTSUPP;
1165 }
1166 
1167 static int
1168 udp6_disconnect(struct socket *so)
1169 {
1170 	struct inpcb *inp = sotoinpcb(so);
1171 	int s;
1172 
1173 	KASSERT(solocked(so));
1174 	KASSERT(inp != NULL);
1175 
1176 	if (IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp)))
1177 		return ENOTCONN;
1178 
1179 	s = splsoftnet();
1180 	in6pcb_disconnect(inp);
1181 	memset((void *)&in6p_laddr(inp), 0, sizeof(in6p_laddr(inp)));
1182 	splx(s);
1183 
1184 	so->so_state &= ~SS_ISCONNECTED;	/* XXX */
1185 	in6pcb_set_state(inp, INP_BOUND);		/* XXX */
1186 	return 0;
1187 }
1188 
1189 static int
1190 udp6_shutdown(struct socket *so)
1191 {
1192 	int s;
1193 
1194 	s = splsoftnet();
1195 	socantsendmore(so);
1196 	splx(s);
1197 
1198 	return 0;
1199 }
1200 
1201 static int
1202 udp6_abort(struct socket *so)
1203 {
1204 	int s;
1205 
1206 	KASSERT(solocked(so));
1207 	KASSERT(sotoinpcb(so) != NULL);
1208 
1209 	s = splsoftnet();
1210 	soisdisconnected(so);
1211 	inpcb_destroy(sotoinpcb(so));
1212 	splx(s);
1213 
1214 	return 0;
1215 }
1216 
1217 static int
1218 udp6_ioctl(struct socket *so, u_long cmd, void *addr6, struct ifnet *ifp)
1219 {
1220 	/*
1221 	 * MAPPED_ADDR implementation info:
1222 	 *  Mapped addr support for PRU_CONTROL is not necessary.
1223 	 *  Because typical user of PRU_CONTROL is such as ifconfig,
1224 	 *  and they don't associate any addr to their socket.  Then
1225 	 *  socket family is only hint about the PRU_CONTROL'ed address
1226 	 *  family, especially when getting addrs from kernel.
1227 	 *  So AF_INET socket need to be used to control AF_INET addrs,
1228 	 *  and AF_INET6 socket for AF_INET6 addrs.
1229 	 */
1230 	return in6_control(so, cmd, addr6, ifp);
1231 }
1232 
1233 static int
1234 udp6_stat(struct socket *so, struct stat *ub)
1235 {
1236 	KASSERT(solocked(so));
1237 
1238 	/* stat: don't bother with a blocksize */
1239 	return 0;
1240 }
1241 
1242 static int
1243 udp6_peeraddr(struct socket *so, struct sockaddr *nam)
1244 {
1245 	KASSERT(solocked(so));
1246 	KASSERT(sotoinpcb(so) != NULL);
1247 	KASSERT(nam != NULL);
1248 
1249 	in6pcb_fetch_peeraddr(sotoinpcb(so), (struct sockaddr_in6 *)nam);
1250 	return 0;
1251 }
1252 
1253 static int
1254 udp6_sockaddr(struct socket *so, struct sockaddr *nam)
1255 {
1256 	KASSERT(solocked(so));
1257 	KASSERT(sotoinpcb(so) != NULL);
1258 	KASSERT(nam != NULL);
1259 
1260 	in6pcb_fetch_sockaddr(sotoinpcb(so), (struct sockaddr_in6 *)nam);
1261 	return 0;
1262 }
1263 
1264 static int
1265 udp6_rcvd(struct socket *so, int flags, struct lwp *l)
1266 {
1267 	KASSERT(solocked(so));
1268 
1269 	return EOPNOTSUPP;
1270 }
1271 
1272 static int
1273 udp6_recvoob(struct socket *so, struct mbuf *m, int flags)
1274 {
1275 	KASSERT(solocked(so));
1276 
1277 	return EOPNOTSUPP;
1278 }
1279 
1280 static int
1281 udp6_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
1282     struct mbuf *control, struct lwp *l)
1283 {
1284 	struct inpcb *inp = sotoinpcb(so);
1285 	int error = 0;
1286 	int s;
1287 
1288 	KASSERT(solocked(so));
1289 	KASSERT(inp != NULL);
1290 	KASSERT(m != NULL);
1291 
1292 	s = splsoftnet();
1293 	error = udp6_output(inp, m, (struct sockaddr_in6 *)nam, control, l);
1294 	splx(s);
1295 
1296 	return error;
1297 }
1298 
1299 static int
1300 udp6_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
1301 {
1302 	KASSERT(solocked(so));
1303 
1304 	m_freem(m);
1305 	m_freem(control);
1306 
1307 	return EOPNOTSUPP;
1308 }
1309 
1310 static int
1311 udp6_purgeif(struct socket *so, struct ifnet *ifp)
1312 {
1313 
1314 	mutex_enter(softnet_lock);
1315 	in6pcb_purgeif0(&udbtable, ifp);
1316 #ifdef NET_MPSAFE
1317 	mutex_exit(softnet_lock);
1318 #endif
1319 	in6_purgeif(ifp);
1320 #ifdef NET_MPSAFE
1321 	mutex_enter(softnet_lock);
1322 #endif
1323 	in6pcb_purgeif(&udbtable, ifp);
1324 	mutex_exit(softnet_lock);
1325 
1326 	return 0;
1327 }
1328 
1329 static int
1330 sysctl_net_inet6_udp6_stats(SYSCTLFN_ARGS)
1331 {
1332 
1333 	return (NETSTAT_SYSCTL(udp6stat_percpu, UDP6_NSTATS));
1334 }
1335 
1336 static void
1337 sysctl_net_inet6_udp6_setup(struct sysctllog **clog)
1338 {
1339 
1340 	sysctl_createv(clog, 0, NULL, NULL,
1341 		       CTLFLAG_PERMANENT,
1342 		       CTLTYPE_NODE, "inet6", NULL,
1343 		       NULL, 0, NULL, 0,
1344 		       CTL_NET, PF_INET6, CTL_EOL);
1345 	sysctl_createv(clog, 0, NULL, NULL,
1346 		       CTLFLAG_PERMANENT,
1347 		       CTLTYPE_NODE, "udp6",
1348 		       SYSCTL_DESCR("UDPv6 related settings"),
1349 		       NULL, 0, NULL, 0,
1350 		       CTL_NET, PF_INET6, IPPROTO_UDP, CTL_EOL);
1351 
1352 	sysctl_createv(clog, 0, NULL, NULL,
1353 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1354 		       CTLTYPE_INT, "sendspace",
1355 		       SYSCTL_DESCR("Default UDP send buffer size"),
1356 		       NULL, 0, &udp6_sendspace, 0,
1357 		       CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_SENDSPACE,
1358 		       CTL_EOL);
1359 	sysctl_createv(clog, 0, NULL, NULL,
1360 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1361 		       CTLTYPE_INT, "recvspace",
1362 		       SYSCTL_DESCR("Default UDP receive buffer size"),
1363 		       NULL, 0, &udp6_recvspace, 0,
1364 		       CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_RECVSPACE,
1365 		       CTL_EOL);
1366 	sysctl_createv(clog, 0, NULL, NULL,
1367 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1368 		       CTLTYPE_INT, "do_loopback_cksum",
1369 		       SYSCTL_DESCR("Perform UDP checksum on loopback"),
1370 		       NULL, 0, &udp_do_loopback_cksum, 0,
1371 		       CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_LOOPBACKCKSUM,
1372 		       CTL_EOL);
1373 	sysctl_createv(clog, 0, NULL, NULL,
1374 		       CTLFLAG_PERMANENT,
1375 		       CTLTYPE_STRUCT, "pcblist",
1376 		       SYSCTL_DESCR("UDP protocol control block list"),
1377 		       sysctl_inpcblist, 0, &udbtable, 0,
1378 		       CTL_NET, PF_INET6, IPPROTO_UDP, CTL_CREATE,
1379 		       CTL_EOL);
1380 	sysctl_createv(clog, 0, NULL, NULL,
1381 		       CTLFLAG_PERMANENT,
1382 		       CTLTYPE_STRUCT, "stats",
1383 		       SYSCTL_DESCR("UDPv6 statistics"),
1384 		       sysctl_net_inet6_udp6_stats, 0, NULL, 0,
1385 		       CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_STATS,
1386 		       CTL_EOL);
1387 }
1388 
1389 void
1390 udp6_statinc(u_int stat)
1391 {
1392 
1393 	KASSERT(stat < UDP6_NSTATS);
1394 	UDP6_STATINC(stat);
1395 }
1396 
1397 #ifdef IPSEC
1398 /*
1399  * Returns:
1400  *     1 if the packet was processed
1401  *     0 if normal UDP processing should take place
1402  *    -1 if an error occurred and m was freed
1403  */
1404 static int
1405 udp6_espinudp(struct mbuf **mp, int off)
1406 {
1407 	const size_t skip = sizeof(struct udphdr);
1408 	size_t len;
1409 	void *data;
1410 	size_t minlen;
1411 	int ip6hdrlen;
1412 	struct ip6_hdr *ip6;
1413 	struct m_tag *tag;
1414 	struct udphdr *udphdr;
1415 	u_int16_t sport, dport;
1416 	struct mbuf *m = *mp;
1417 	uint32_t *marker;
1418 
1419 	/*
1420 	 * Collapse the mbuf chain if the first mbuf is too short
1421 	 * The longest case is: UDP + non ESP marker + ESP
1422 	 */
1423 	minlen = off + sizeof(u_int64_t) + sizeof(struct esp);
1424 	if (minlen > m->m_pkthdr.len)
1425 		minlen = m->m_pkthdr.len;
1426 
1427 	if (m->m_len < minlen) {
1428 		if ((*mp = m_pullup(m, minlen)) == NULL) {
1429 			return -1;
1430 		}
1431 		m = *mp;
1432 	}
1433 
1434 	len = m->m_len - off;
1435 	data = mtod(m, char *) + off;
1436 
1437 	/* Ignore keepalive packets */
1438 	if ((len == 1) && (*(unsigned char *)data == 0xff)) {
1439 		m_freem(m);
1440 		*mp = NULL; /* avoid any further processing by caller ... */
1441 		return 1;
1442 	}
1443 
1444 	/* Handle Non-ESP marker (32bit). If zero, then IKE. */
1445 	marker = (uint32_t *)data;
1446 	if (len <= sizeof(uint32_t))
1447 		return 0;
1448 	if (marker[0] == 0)
1449 		return 0;
1450 
1451 	/*
1452 	 * Get the UDP ports. They are handled in network
1453 	 * order everywhere in IPSEC_NAT_T code.
1454 	 */
1455 	udphdr = (struct udphdr *)((char *)data - skip);
1456 	sport = udphdr->uh_sport;
1457 	dport = udphdr->uh_dport;
1458 
1459 	/*
1460 	 * Remove the UDP header (and possibly the non ESP marker)
1461 	 * IPv6 header length is ip6hdrlen
1462 	 * Before:
1463 	 *   <---- off --->
1464 	 *   +-----+------+-----+
1465 	 *   | IP6 |  UDP | ESP |
1466 	 *   +-----+------+-----+
1467 	 *         <-skip->
1468 	 * After:
1469 	 *          +-----+-----+
1470 	 *          | IP6 | ESP |
1471 	 *          +-----+-----+
1472 	 *   <-skip->
1473 	 */
1474 	ip6hdrlen = off - sizeof(struct udphdr);
1475 	memmove(mtod(m, char *) + skip, mtod(m, void *), ip6hdrlen);
1476 	m_adj(m, skip);
1477 
1478 	ip6 = mtod(m, struct ip6_hdr *);
1479 	ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - skip);
1480 	ip6->ip6_nxt = IPPROTO_ESP;
1481 
1482 	/*
1483 	 * We have modified the packet - it is now ESP, so we should not
1484 	 * return to UDP processing ...
1485 	 *
1486 	 * Add a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1487 	 * the source UDP port. This is required if we want
1488 	 * to select the right SPD for multiple hosts behind
1489 	 * same NAT
1490 	 */
1491 	if ((tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1492 	    sizeof(sport) + sizeof(dport), M_DONTWAIT)) == NULL) {
1493 		m_freem(m);
1494 		return -1;
1495 	}
1496 	((u_int16_t *)(tag + 1))[0] = sport;
1497 	((u_int16_t *)(tag + 1))[1] = dport;
1498 	m_tag_prepend(m, tag);
1499 
1500 	if (ipsec_used)
1501 		ipsec6_common_input(&m, &ip6hdrlen, IPPROTO_ESP);
1502 	else
1503 		m_freem(m);
1504 
1505 	/* We handled it, it shouldn't be handled by UDP */
1506 	*mp = NULL; /* avoid free by caller ... */
1507 	return 1;
1508 }
1509 #endif /* IPSEC */
1510 
1511 PR_WRAP_USRREQS(udp6)
1512 #define	udp6_attach	udp6_attach_wrapper
1513 #define	udp6_detach	udp6_detach_wrapper
1514 #define	udp6_accept	udp6_accept_wrapper
1515 #define	udp6_bind	udp6_bind_wrapper
1516 #define	udp6_listen	udp6_listen_wrapper
1517 #define	udp6_connect	udp6_connect_wrapper
1518 #define	udp6_connect2	udp6_connect2_wrapper
1519 #define	udp6_disconnect	udp6_disconnect_wrapper
1520 #define	udp6_shutdown	udp6_shutdown_wrapper
1521 #define	udp6_abort	udp6_abort_wrapper
1522 #define	udp6_ioctl	udp6_ioctl_wrapper
1523 #define	udp6_stat	udp6_stat_wrapper
1524 #define	udp6_peeraddr	udp6_peeraddr_wrapper
1525 #define	udp6_sockaddr	udp6_sockaddr_wrapper
1526 #define	udp6_rcvd	udp6_rcvd_wrapper
1527 #define	udp6_recvoob	udp6_recvoob_wrapper
1528 #define	udp6_send	udp6_send_wrapper
1529 #define	udp6_sendoob	udp6_sendoob_wrapper
1530 #define	udp6_purgeif	udp6_purgeif_wrapper
1531 
1532 const struct pr_usrreqs udp6_usrreqs = {
1533 	.pr_attach	= udp6_attach,
1534 	.pr_detach	= udp6_detach,
1535 	.pr_accept	= udp6_accept,
1536 	.pr_bind	= udp6_bind,
1537 	.pr_listen	= udp6_listen,
1538 	.pr_connect	= udp6_connect,
1539 	.pr_connect2	= udp6_connect2,
1540 	.pr_disconnect	= udp6_disconnect,
1541 	.pr_shutdown	= udp6_shutdown,
1542 	.pr_abort	= udp6_abort,
1543 	.pr_ioctl	= udp6_ioctl,
1544 	.pr_stat	= udp6_stat,
1545 	.pr_peeraddr	= udp6_peeraddr,
1546 	.pr_sockaddr	= udp6_sockaddr,
1547 	.pr_rcvd	= udp6_rcvd,
1548 	.pr_recvoob	= udp6_recvoob,
1549 	.pr_send	= udp6_send,
1550 	.pr_sendoob	= udp6_sendoob,
1551 	.pr_purgeif	= udp6_purgeif,
1552 };
1553