xref: /netbsd-src/sys/netinet6/udp6_usrreq.c (revision f89f6560d453f5e37386cc7938c072d2f528b9fa)
1 /*	$NetBSD: udp6_usrreq.c,v 1.117 2015/04/03 20:01:07 rtr Exp $	*/
2 /*	$KAME: udp6_usrreq.c,v 1.86 2001/05/27 17:33:00 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. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
62  */
63 
64 #include <sys/cdefs.h>
65 __KERNEL_RCSID(0, "$NetBSD: udp6_usrreq.c,v 1.117 2015/04/03 20:01:07 rtr Exp $");
66 
67 #include "opt_inet.h"
68 #include "opt_inet_csum.h"
69 #include "opt_ipsec.h"
70 
71 #include <sys/param.h>
72 #include <sys/mbuf.h>
73 #include <sys/protosw.h>
74 #include <sys/socket.h>
75 #include <sys/socketvar.h>
76 #include <sys/systm.h>
77 #include <sys/proc.h>
78 #include <sys/syslog.h>
79 #include <sys/domain.h>
80 #include <sys/sysctl.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/in_offload.h>
90 #include <netinet/ip.h>
91 #include <netinet/ip_var.h>
92 #include <netinet/in_pcb.h>
93 #include <netinet/udp.h>
94 #include <netinet/udp_var.h>
95 #include <netinet/udp_private.h>
96 
97 #include <netinet/ip6.h>
98 #include <netinet/icmp6.h>
99 #include <netinet6/ip6_var.h>
100 #include <netinet6/ip6_private.h>
101 #include <netinet6/in6_pcb.h>
102 #include <netinet6/udp6_var.h>
103 #include <netinet6/udp6_private.h>
104 #include <netinet6/ip6protosw.h>
105 #include <netinet6/scope6_var.h>
106 
107 #ifdef IPSEC
108 #include <netipsec/ipsec.h>
109 #include <netipsec/ipsec_var.h>
110 #include <netipsec/ipsec_private.h>
111 #ifdef INET6
112 #include <netipsec/ipsec6.h>
113 #endif
114 #endif	/* IPSEC */
115 
116 #include "faith.h"
117 #if defined(NFAITH) && NFAITH > 0
118 #include <net/if_faith.h>
119 #endif
120 
121 /*
122  * UDP protocol implementation.
123  * Per RFC 768, August, 1980.
124  */
125 
126 extern struct inpcbtable udbtable;
127 
128 percpu_t *udp6stat_percpu;
129 
130 /* UDP on IP6 parameters */
131 static int	udp6_sendspace = 9216;	/* really max datagram size */
132 static int	udp6_recvspace = 40 * (1024 + sizeof(struct sockaddr_in6));
133 					/* 40 1K datagrams */
134 
135 static	void udp6_notify(struct in6pcb *, int);
136 static	void sysctl_net_inet6_udp6_setup(struct sysctllog **);
137 
138 #ifdef UDP_CSUM_COUNTERS
139 #include <sys/device.h>
140 struct evcnt udp6_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
141     NULL, "udp6", "hwcsum bad");
142 struct evcnt udp6_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
143     NULL, "udp6", "hwcsum ok");
144 struct evcnt udp6_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
145     NULL, "udp6", "hwcsum data");
146 struct evcnt udp6_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
147     NULL, "udp6", "swcsum");
148 
149 EVCNT_ATTACH_STATIC(udp6_hwcsum_bad);
150 EVCNT_ATTACH_STATIC(udp6_hwcsum_ok);
151 EVCNT_ATTACH_STATIC(udp6_hwcsum_data);
152 EVCNT_ATTACH_STATIC(udp6_swcsum);
153 
154 #define	UDP_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
155 #else
156 #define	UDP_CSUM_COUNTER_INCR(ev)	/* nothing */
157 #endif
158 
159 void
160 udp6_init(void)
161 {
162 	sysctl_net_inet6_udp6_setup(NULL);
163 	udp6stat_percpu = percpu_alloc(sizeof(uint64_t) * UDP6_NSTATS);
164 
165 	udp_init_common();
166 }
167 
168 /*
169  * Notify a udp user of an asynchronous error;
170  * just wake up so that he can collect error status.
171  */
172 static	void
173 udp6_notify(struct in6pcb *in6p, int errno)
174 {
175 	in6p->in6p_socket->so_error = errno;
176 	sorwakeup(in6p->in6p_socket);
177 	sowwakeup(in6p->in6p_socket);
178 }
179 
180 void *
181 udp6_ctlinput(int cmd, const struct sockaddr *sa, void *d)
182 {
183 	struct udphdr uh;
184 	struct ip6_hdr *ip6;
185 	const struct sockaddr_in6 *sa6 = (const struct sockaddr_in6 *)sa;
186 	struct mbuf *m;
187 	int off;
188 	void *cmdarg;
189 	struct ip6ctlparam *ip6cp = NULL;
190 	const struct sockaddr_in6 *sa6_src = NULL;
191 	void (*notify)(struct in6pcb *, int) = udp6_notify;
192 	struct udp_portonly {
193 		u_int16_t uh_sport;
194 		u_int16_t uh_dport;
195 	} *uhp;
196 
197 	if (sa->sa_family != AF_INET6 ||
198 	    sa->sa_len != sizeof(struct sockaddr_in6))
199 		return NULL;
200 
201 	if ((unsigned)cmd >= PRC_NCMDS)
202 		return NULL;
203 	if (PRC_IS_REDIRECT(cmd))
204 		notify = in6_rtchange, d = NULL;
205 	else if (cmd == PRC_HOSTDEAD)
206 		d = NULL;
207 	else if (cmd == PRC_MSGSIZE) {
208 		/* special code is present, see below */
209 		notify = in6_rtchange;
210 	}
211 	else if (inet6ctlerrmap[cmd] == 0)
212 		return NULL;
213 
214 	/* if the parameter is from icmp6, decode it. */
215 	if (d != NULL) {
216 		ip6cp = (struct ip6ctlparam *)d;
217 		m = ip6cp->ip6c_m;
218 		ip6 = ip6cp->ip6c_ip6;
219 		off = ip6cp->ip6c_off;
220 		cmdarg = ip6cp->ip6c_cmdarg;
221 		sa6_src = ip6cp->ip6c_src;
222 	} else {
223 		m = NULL;
224 		ip6 = NULL;
225 		cmdarg = NULL;
226 		sa6_src = &sa6_any;
227 		off = 0;
228 	}
229 
230 	if (ip6) {
231 		/*
232 		 * XXX: We assume that when IPV6 is non NULL,
233 		 * M and OFF are valid.
234 		 */
235 
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 (in6_pcblookup_connect(&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 (in6_pcblookup_bind(&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 			 * in6_pcbnotify(), 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) in6_pcbnotify(&udbtable, sa, uh.uh_dport,
291 		    (const struct sockaddr *)sa6_src, uh.uh_sport, cmd, cmdarg,
292 		    notify);
293 	} else {
294 		(void) in6_pcbnotify(&udbtable, sa, 0,
295 		    (const struct sockaddr *)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 	int family;
306 
307 	family = so->so_proto->pr_domain->dom_family;
308 
309 	s = splsoftnet();
310 	switch (family) {
311 #ifdef INET
312 	case PF_INET:
313 		if (sopt->sopt_level != IPPROTO_UDP) {
314 			error = ip_ctloutput(op, so, sopt);
315 			goto end;
316 		}
317 		break;
318 #endif
319 #ifdef INET6
320 	case PF_INET6:
321 		if (sopt->sopt_level != IPPROTO_UDP) {
322 			error = ip6_ctloutput(op, so, sopt);
323 			goto end;
324 		}
325 		break;
326 #endif
327 	default:
328 		error = EAFNOSUPPORT;
329 		goto end;
330 	}
331 	error = EINVAL;
332 
333 end:
334 	splx(s);
335 	return error;
336 }
337 
338 static void
339 udp6_sendup(struct mbuf *m, int off /* offset of data portion */,
340 	struct sockaddr *src, struct socket *so)
341 {
342 	struct mbuf *opts = NULL;
343 	struct mbuf *n;
344 	struct in6pcb *in6p = NULL;
345 
346 	if (!so)
347 		return;
348 	if (so->so_proto->pr_domain->dom_family != AF_INET6)
349 		return;
350 	in6p = sotoin6pcb(so);
351 
352 #if defined(IPSEC)
353 	/* check AH/ESP integrity. */
354 	if (ipsec_used && so != NULL && ipsec6_in_reject_so(m, so)) {
355 		IPSEC6_STATINC(IPSEC_STAT_IN_POLVIO);
356 		if ((n = m_copypacket(m, M_DONTWAIT)) != NULL)
357 			icmp6_error(n, ICMP6_DST_UNREACH,
358 			    ICMP6_DST_UNREACH_ADMIN, 0);
359 		return;
360 	}
361 #endif /*IPSEC*/
362 
363 	if ((n = m_copypacket(m, M_DONTWAIT)) != NULL) {
364 		if (in6p && (in6p->in6p_flags & IN6P_CONTROLOPTS
365 #ifdef SO_OTIMESTAMP
366 		    || in6p->in6p_socket->so_options & SO_OTIMESTAMP
367 #endif
368 		    || in6p->in6p_socket->so_options & SO_TIMESTAMP)) {
369 			struct ip6_hdr *ip6 = mtod(n, struct ip6_hdr *);
370 			ip6_savecontrol(in6p, &opts, ip6, n);
371 		}
372 
373 		m_adj(n, off);
374 		if (sbappendaddr(&so->so_rcv, src, n, opts) == 0) {
375 			m_freem(n);
376 			if (opts)
377 				m_freem(opts);
378 			so->so_rcv.sb_overflowed++;
379 			UDP6_STATINC(UDP6_STAT_FULLSOCK);
380 		} else
381 			sorwakeup(so);
382 	}
383 }
384 
385 int
386 udp6_realinput(int af, struct sockaddr_in6 *src, struct sockaddr_in6 *dst,
387 	struct mbuf *m, int off)
388 {
389 	u_int16_t sport, dport;
390 	int rcvcnt;
391 	struct in6_addr src6, *dst6;
392 	const struct in_addr *dst4;
393 	struct inpcb_hdr *inph;
394 	struct in6pcb *in6p;
395 
396 	rcvcnt = 0;
397 	off += sizeof(struct udphdr);	/* now, offset of payload */
398 
399 	if (af != AF_INET && af != AF_INET6)
400 		goto bad;
401 	if (src->sin6_family != AF_INET6 || dst->sin6_family != AF_INET6)
402 		goto bad;
403 
404 	src6 = src->sin6_addr;
405 	if (sa6_recoverscope(src) != 0) {
406 		/* XXX: should be impossible. */
407 		goto bad;
408 	}
409 	sport = src->sin6_port;
410 
411 	dport = dst->sin6_port;
412 	dst4 = (struct in_addr *)&dst->sin6_addr.s6_addr[12];
413 	dst6 = &dst->sin6_addr;
414 
415 	if (IN6_IS_ADDR_MULTICAST(dst6) ||
416 	    (af == AF_INET && IN_MULTICAST(dst4->s_addr))) {
417 		/*
418 		 * Deliver a multicast or broadcast datagram to *all* sockets
419 		 * for which the local and remote addresses and ports match
420 		 * those of the incoming datagram.  This allows more than
421 		 * one process to receive multi/broadcasts on the same port.
422 		 * (This really ought to be done for unicast datagrams as
423 		 * well, but that would cause problems with existing
424 		 * applications that open both address-specific sockets and
425 		 * a wildcard socket listening to the same port -- they would
426 		 * end up receiving duplicates of every unicast datagram.
427 		 * Those applications open the multiple sockets to overcome an
428 		 * inadequacy of the UDP socket interface, but for backwards
429 		 * compatibility we avoid the problem here rather than
430 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
431 		 */
432 
433 		/*
434 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
435 		 * we need udpiphdr for IPsec processing so we do that later.
436 		 */
437 		/*
438 		 * Locate pcb(s) for datagram.
439 		 */
440 		TAILQ_FOREACH(inph, &udbtable.inpt_queue, inph_queue) {
441 			in6p = (struct in6pcb *)inph;
442 			if (in6p->in6p_af != AF_INET6)
443 				continue;
444 
445 			if (in6p->in6p_lport != dport)
446 				continue;
447 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
448 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
449 				    dst6))
450 					continue;
451 			} else {
452 				if (IN6_IS_ADDR_V4MAPPED(dst6) &&
453 				    (in6p->in6p_flags & IN6P_IPV6_V6ONLY))
454 					continue;
455 			}
456 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
457 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
458 				    &src6) || in6p->in6p_fport != sport)
459 					continue;
460 			} else {
461 				if (IN6_IS_ADDR_V4MAPPED(&src6) &&
462 				    (in6p->in6p_flags & IN6P_IPV6_V6ONLY))
463 					continue;
464 			}
465 
466 			udp6_sendup(m, off, (struct sockaddr *)src,
467 				in6p->in6p_socket);
468 			rcvcnt++;
469 
470 			/*
471 			 * Don't look for additional matches if this one does
472 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
473 			 * socket options set.  This heuristic avoids searching
474 			 * through all pcbs in the common case of a non-shared
475 			 * port.  It assumes that an application will never
476 			 * clear these options after setting them.
477 			 */
478 			if ((in6p->in6p_socket->so_options &
479 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
480 				break;
481 		}
482 	} else {
483 		/*
484 		 * Locate pcb for datagram.
485 		 */
486 		in6p = in6_pcblookup_connect(&udbtable, &src6, sport, dst6,
487 					     dport, 0, 0);
488 		if (in6p == 0) {
489 			UDP_STATINC(UDP_STAT_PCBHASHMISS);
490 			in6p = in6_pcblookup_bind(&udbtable, dst6, dport, 0);
491 			if (in6p == 0)
492 				return rcvcnt;
493 		}
494 
495 		udp6_sendup(m, off, (struct sockaddr *)src, in6p->in6p_socket);
496 		rcvcnt++;
497 	}
498 
499 bad:
500 	return rcvcnt;
501 }
502 
503 int
504 udp6_input_checksum(struct mbuf *m, const struct udphdr *uh, int off, int len)
505 {
506 
507 	/*
508 	 * XXX it's better to record and check if this mbuf is
509 	 * already checked.
510 	 */
511 
512 	if (__predict_false((m->m_flags & M_LOOP) && !udp_do_loopback_cksum)) {
513 		goto good;
514 	}
515 	if (uh->uh_sum == 0) {
516 		UDP6_STATINC(UDP6_STAT_NOSUM);
517 		goto bad;
518 	}
519 
520 	switch (m->m_pkthdr.csum_flags &
521 	    ((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_UDPv6) |
522 	    M_CSUM_TCP_UDP_BAD | M_CSUM_DATA)) {
523 	case M_CSUM_UDPv6|M_CSUM_TCP_UDP_BAD:
524 		UDP_CSUM_COUNTER_INCR(&udp6_hwcsum_bad);
525 		UDP6_STATINC(UDP6_STAT_BADSUM);
526 		goto bad;
527 
528 #if 0 /* notyet */
529 	case M_CSUM_UDPv6|M_CSUM_DATA:
530 #endif
531 
532 	case M_CSUM_UDPv6:
533 		/* Checksum was okay. */
534 		UDP_CSUM_COUNTER_INCR(&udp6_hwcsum_ok);
535 		break;
536 
537 	default:
538 		/*
539 		 * Need to compute it ourselves.  Maybe skip checksum
540 		 * on loopback interfaces.
541 		 */
542 		UDP_CSUM_COUNTER_INCR(&udp6_swcsum);
543 		if (in6_cksum(m, IPPROTO_UDP, off, len) != 0) {
544 			UDP6_STATINC(UDP6_STAT_BADSUM);
545 			goto bad;
546 		}
547 	}
548 
549 good:
550 	return 0;
551 bad:
552 	return -1;
553 }
554 
555 int
556 udp6_input(struct mbuf **mp, int *offp, int proto)
557 {
558 	struct mbuf *m = *mp;
559 	int off = *offp;
560 	struct sockaddr_in6 src, dst;
561 	struct ip6_hdr *ip6;
562 	struct udphdr *uh;
563 	u_int32_t plen, ulen;
564 
565 	ip6 = mtod(m, struct ip6_hdr *);
566 
567 #if defined(NFAITH) && 0 < NFAITH
568 	if (faithprefix(&ip6->ip6_dst)) {
569 		/* send icmp6 host unreach? */
570 		m_freem(m);
571 		return IPPROTO_DONE;
572 	}
573 #endif
574 
575 	UDP6_STATINC(UDP6_STAT_IPACKETS);
576 
577 	/* check for jumbogram is done in ip6_input.  we can trust pkthdr.len */
578 	plen = m->m_pkthdr.len - off;
579 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(struct udphdr));
580 	if (uh == NULL) {
581 		IP6_STATINC(IP6_STAT_TOOSHORT);
582 		return IPPROTO_DONE;
583 	}
584 	KASSERT(UDP_HDR_ALIGNED_P(uh));
585 	ulen = ntohs((u_short)uh->uh_ulen);
586 	/*
587 	 * RFC2675 section 4: jumbograms will have 0 in the UDP header field,
588 	 * iff payload length > 0xffff.
589 	 */
590 	if (ulen == 0 && plen > 0xffff)
591 		ulen = plen;
592 
593 	if (plen != ulen) {
594 		UDP6_STATINC(UDP6_STAT_BADLEN);
595 		goto bad;
596 	}
597 
598 	/* destination port of 0 is illegal, based on RFC768. */
599 	if (uh->uh_dport == 0)
600 		goto bad;
601 
602 	/* Be proactive about malicious use of IPv4 mapped address */
603 	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
604 	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
605 		/* XXX stat */
606 		goto bad;
607 	}
608 
609 	/*
610 	 * Checksum extended UDP header and data.  Maybe skip checksum
611 	 * on loopback interfaces.
612 	 */
613 	if (udp6_input_checksum(m, uh, off, ulen))
614 		goto bad;
615 
616 	/*
617 	 * Construct source and dst sockaddrs.
618 	 */
619 	memset(&src, 0, sizeof(src));
620 	src.sin6_family = AF_INET6;
621 	src.sin6_len = sizeof(struct sockaddr_in6);
622 	src.sin6_addr = ip6->ip6_src;
623 	src.sin6_port = uh->uh_sport;
624 	memset(&dst, 0, sizeof(dst));
625 	dst.sin6_family = AF_INET6;
626 	dst.sin6_len = sizeof(struct sockaddr_in6);
627 	dst.sin6_addr = ip6->ip6_dst;
628 	dst.sin6_port = uh->uh_dport;
629 
630 	if (udp6_realinput(AF_INET6, &src, &dst, m, off) == 0) {
631 		if (m->m_flags & M_MCAST) {
632 			UDP6_STATINC(UDP6_STAT_NOPORTMCAST);
633 			goto bad;
634 		}
635 		UDP6_STATINC(UDP6_STAT_NOPORT);
636 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
637 		m = NULL;
638 	}
639 
640 bad:
641 	if (m)
642 		m_freem(m);
643 	return IPPROTO_DONE;
644 }
645 
646 static int
647 udp6_attach(struct socket *so, int proto)
648 {
649 	struct in6pcb *in6p;
650 	int s, error;
651 
652 	KASSERT(sotoin6pcb(so) == NULL);
653 	sosetlock(so);
654 
655 	/*
656 	 * MAPPED_ADDR implementation spec:
657 	 *  Always attach for IPv6, and only when necessary for IPv4.
658 	 */
659 	s = splsoftnet();
660 	error = in6_pcballoc(so, &udbtable);
661 	splx(s);
662 	if (error) {
663 		return error;
664 	}
665 	error = soreserve(so, udp6_sendspace, udp6_recvspace);
666 	if (error) {
667 		return error;
668 	}
669 	in6p = sotoin6pcb(so);
670 	in6p->in6p_cksum = -1;	/* just to be sure */
671 
672 	KASSERT(solocked(so));
673 	return 0;
674 }
675 
676 static void
677 udp6_detach(struct socket *so)
678 {
679 	struct in6pcb *in6p = sotoin6pcb(so);
680 	int s;
681 
682 	KASSERT(solocked(so));
683 	KASSERT(in6p != NULL);
684 
685 	s = splsoftnet();
686 	in6_pcbdetach(in6p);
687 	splx(s);
688 }
689 
690 static int
691 udp6_accept(struct socket *so, struct mbuf *nam)
692 {
693 	KASSERT(solocked(so));
694 
695 	return EOPNOTSUPP;
696 }
697 
698 static int
699 udp6_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
700 {
701 	struct in6pcb *in6p = sotoin6pcb(so);
702 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
703 	int error = 0;
704 	int s;
705 
706 	KASSERT(solocked(so));
707 	KASSERT(in6p != NULL);
708 
709 	s = splsoftnet();
710 	error = in6_pcbbind(in6p, sin6, l);
711 	splx(s);
712 	return error;
713 }
714 
715 static int
716 udp6_listen(struct socket *so, struct lwp *l)
717 {
718 	KASSERT(solocked(so));
719 
720 	return EOPNOTSUPP;
721 }
722 
723 static int
724 udp6_connect(struct socket *so, struct mbuf *nam, struct lwp *l)
725 {
726 	struct in6pcb *in6p = sotoin6pcb(so);
727 	int error = 0;
728 	int s;
729 
730 	KASSERT(solocked(so));
731 	KASSERT(in6p != NULL);
732 
733 	if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr))
734 		return EISCONN;
735 	s = splsoftnet();
736 	error = in6_pcbconnect(in6p, nam, l);
737 	splx(s);
738 	if (error == 0)
739 		soisconnected(so);
740 
741 	return error;
742 }
743 
744 static int
745 udp6_connect2(struct socket *so, struct socket *so2)
746 {
747 	KASSERT(solocked(so));
748 
749 	return EOPNOTSUPP;
750 }
751 
752 static int
753 udp6_disconnect(struct socket *so)
754 {
755 	struct in6pcb *in6p = sotoin6pcb(so);
756 	int s;
757 
758 	KASSERT(solocked(so));
759 	KASSERT(in6p != NULL);
760 
761 	if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr))
762 		return ENOTCONN;
763 
764 	s = splsoftnet();
765 	in6_pcbdisconnect(in6p);
766 	memset((void *)&in6p->in6p_laddr, 0, sizeof(in6p->in6p_laddr));
767 	splx(s);
768 
769 	so->so_state &= ~SS_ISCONNECTED;	/* XXX */
770 	in6_pcbstate(in6p, IN6P_BOUND);		/* XXX */
771 	return 0;
772 }
773 
774 static int
775 udp6_shutdown(struct socket *so)
776 {
777 	int s;
778 
779 	s = splsoftnet();
780 	socantsendmore(so);
781 	splx(s);
782 
783 	return 0;
784 }
785 
786 static int
787 udp6_abort(struct socket *so)
788 {
789 	int s;
790 
791 	KASSERT(solocked(so));
792 	KASSERT(sotoin6pcb(so) != NULL);
793 
794 	s = splsoftnet();
795 	soisdisconnected(so);
796 	in6_pcbdetach(sotoin6pcb(so));
797 	splx(s);
798 
799 	return 0;
800 }
801 
802 static int
803 udp6_ioctl(struct socket *so, u_long cmd, void *addr6, struct ifnet *ifp)
804 {
805 	/*
806 	 * MAPPED_ADDR implementation info:
807 	 *  Mapped addr support for PRU_CONTROL is not necessary.
808 	 *  Because typical user of PRU_CONTROL is such as ifconfig,
809 	 *  and they don't associate any addr to their socket.  Then
810 	 *  socket family is only hint about the PRU_CONTROL'ed address
811 	 *  family, especially when getting addrs from kernel.
812 	 *  So AF_INET socket need to be used to control AF_INET addrs,
813 	 *  and AF_INET6 socket for AF_INET6 addrs.
814 	 */
815 	return in6_control(so, cmd, addr6, ifp);
816 }
817 
818 static int
819 udp6_stat(struct socket *so, struct stat *ub)
820 {
821 	KASSERT(solocked(so));
822 
823 	/* stat: don't bother with a blocksize */
824 	return 0;
825 }
826 
827 static int
828 udp6_peeraddr(struct socket *so, struct mbuf *nam)
829 {
830 	KASSERT(solocked(so));
831 	KASSERT(sotoin6pcb(so) != NULL);
832 	KASSERT(nam != NULL);
833 
834 	in6_setpeeraddr(sotoin6pcb(so), nam);
835 	return 0;
836 }
837 
838 static int
839 udp6_sockaddr(struct socket *so, struct mbuf *nam)
840 {
841 	KASSERT(solocked(so));
842 	KASSERT(sotoin6pcb(so) != NULL);
843 	KASSERT(nam != NULL);
844 
845 	in6_setsockaddr(sotoin6pcb(so), nam);
846 	return 0;
847 }
848 
849 static int
850 udp6_rcvd(struct socket *so, int flags, struct lwp *l)
851 {
852 	KASSERT(solocked(so));
853 
854 	return EOPNOTSUPP;
855 }
856 
857 static int
858 udp6_recvoob(struct socket *so, struct mbuf *m, int flags)
859 {
860 	KASSERT(solocked(so));
861 
862 	return EOPNOTSUPP;
863 }
864 
865 static int
866 udp6_send(struct socket *so, struct mbuf *m, struct mbuf *nam,
867     struct mbuf *control, struct lwp *l)
868 {
869 	struct in6pcb *in6p = sotoin6pcb(so);
870 	int error = 0;
871 	int s;
872 
873 	KASSERT(solocked(so));
874 	KASSERT(in6p != NULL);
875 	KASSERT(m != NULL);
876 
877 	s = splsoftnet();
878 	error = udp6_output(in6p, m, nam, control, l);
879 	splx(s);
880 
881 	return error;
882 }
883 
884 static int
885 udp6_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
886 {
887 	KASSERT(solocked(so));
888 
889 	if (m)
890 		m_freem(m);
891 	if (control)
892 		m_freem(control);
893 
894 	return EOPNOTSUPP;
895 }
896 
897 static int
898 udp6_purgeif(struct socket *so, struct ifnet *ifp)
899 {
900 
901 	mutex_enter(softnet_lock);
902 	in6_pcbpurgeif0(&udbtable, ifp);
903 	in6_purgeif(ifp);
904 	in6_pcbpurgeif(&udbtable, ifp);
905 	mutex_exit(softnet_lock);
906 
907 	return 0;
908 }
909 
910 int
911 udp6_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *addr6,
912     struct mbuf *control, struct lwp *l)
913 {
914 	int error = 0;
915 
916 	KASSERT(req != PRU_ATTACH);
917 	KASSERT(req != PRU_DETACH);
918 	KASSERT(req != PRU_ACCEPT);
919 	KASSERT(req != PRU_BIND);
920 	KASSERT(req != PRU_LISTEN);
921 	KASSERT(req != PRU_CONNECT);
922 	KASSERT(req != PRU_CONNECT2);
923 	KASSERT(req != PRU_DISCONNECT);
924 	KASSERT(req != PRU_SHUTDOWN);
925 	KASSERT(req != PRU_ABORT);
926 	KASSERT(req != PRU_CONTROL);
927 	KASSERT(req != PRU_SENSE);
928 	KASSERT(req != PRU_PEERADDR);
929 	KASSERT(req != PRU_SOCKADDR);
930 	KASSERT(req != PRU_RCVD);
931 	KASSERT(req != PRU_RCVOOB);
932 	KASSERT(req != PRU_SEND);
933 	KASSERT(req != PRU_SENDOOB);
934 	KASSERT(req != PRU_PURGEIF);
935 
936 	if (sotoin6pcb(so) == NULL) {
937 		error = EINVAL;
938 		goto release;
939 	}
940 
941 	switch (req) {
942 	case PRU_FASTTIMO:
943 	case PRU_SLOWTIMO:
944 	case PRU_PROTORCV:
945 	case PRU_PROTOSEND:
946 		error = EOPNOTSUPP;
947 		break;
948 
949 	default:
950 		panic("udp6_usrreq");
951 	}
952 
953 release:
954 	if (control != NULL)
955 		m_freem(control);
956 	if (m != NULL)
957 		m_freem(m);
958 	return error;
959 }
960 
961 static int
962 sysctl_net_inet6_udp6_stats(SYSCTLFN_ARGS)
963 {
964 
965 	return (NETSTAT_SYSCTL(udp6stat_percpu, UDP6_NSTATS));
966 }
967 
968 static void
969 sysctl_net_inet6_udp6_setup(struct sysctllog **clog)
970 {
971 
972 	sysctl_createv(clog, 0, NULL, NULL,
973 		       CTLFLAG_PERMANENT,
974 		       CTLTYPE_NODE, "inet6", NULL,
975 		       NULL, 0, NULL, 0,
976 		       CTL_NET, PF_INET6, CTL_EOL);
977 	sysctl_createv(clog, 0, NULL, NULL,
978 		       CTLFLAG_PERMANENT,
979 		       CTLTYPE_NODE, "udp6",
980 		       SYSCTL_DESCR("UDPv6 related settings"),
981 		       NULL, 0, NULL, 0,
982 		       CTL_NET, PF_INET6, IPPROTO_UDP, CTL_EOL);
983 
984 	sysctl_createv(clog, 0, NULL, NULL,
985 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
986 		       CTLTYPE_INT, "sendspace",
987 		       SYSCTL_DESCR("Default UDP send buffer size"),
988 		       NULL, 0, &udp6_sendspace, 0,
989 		       CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_SENDSPACE,
990 		       CTL_EOL);
991 	sysctl_createv(clog, 0, NULL, NULL,
992 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
993 		       CTLTYPE_INT, "recvspace",
994 		       SYSCTL_DESCR("Default UDP receive buffer size"),
995 		       NULL, 0, &udp6_recvspace, 0,
996 		       CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_RECVSPACE,
997 		       CTL_EOL);
998 	sysctl_createv(clog, 0, NULL, NULL,
999 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1000 		       CTLTYPE_INT, "do_loopback_cksum",
1001 		       SYSCTL_DESCR("Perform UDP checksum on loopback"),
1002 		       NULL, 0, &udp_do_loopback_cksum, 0,
1003 		       CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_LOOPBACKCKSUM,
1004 		       CTL_EOL);
1005 	sysctl_createv(clog, 0, NULL, NULL,
1006 		       CTLFLAG_PERMANENT,
1007 		       CTLTYPE_STRUCT, "pcblist",
1008 		       SYSCTL_DESCR("UDP protocol control block list"),
1009 		       sysctl_inpcblist, 0, &udbtable, 0,
1010 		       CTL_NET, PF_INET6, IPPROTO_UDP, CTL_CREATE,
1011 		       CTL_EOL);
1012 	sysctl_createv(clog, 0, NULL, NULL,
1013 		       CTLFLAG_PERMANENT,
1014 		       CTLTYPE_STRUCT, "stats",
1015 		       SYSCTL_DESCR("UDPv6 statistics"),
1016 		       sysctl_net_inet6_udp6_stats, 0, NULL, 0,
1017 		       CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_STATS,
1018 		       CTL_EOL);
1019 }
1020 
1021 void
1022 udp6_statinc(u_int stat)
1023 {
1024 
1025 	KASSERT(stat < UDP6_NSTATS);
1026 	UDP6_STATINC(stat);
1027 }
1028 
1029 PR_WRAP_USRREQS(udp6)
1030 #define	udp6_attach	udp6_attach_wrapper
1031 #define	udp6_detach	udp6_detach_wrapper
1032 #define	udp6_accept	udp6_accept_wrapper
1033 #define	udp6_bind	udp6_bind_wrapper
1034 #define	udp6_listen	udp6_listen_wrapper
1035 #define	udp6_connect	udp6_connect_wrapper
1036 #define	udp6_connect2	udp6_connect2_wrapper
1037 #define	udp6_disconnect	udp6_disconnect_wrapper
1038 #define	udp6_shutdown	udp6_shutdown_wrapper
1039 #define	udp6_abort	udp6_abort_wrapper
1040 #define	udp6_ioctl	udp6_ioctl_wrapper
1041 #define	udp6_stat	udp6_stat_wrapper
1042 #define	udp6_peeraddr	udp6_peeraddr_wrapper
1043 #define	udp6_sockaddr	udp6_sockaddr_wrapper
1044 #define	udp6_rcvd	udp6_rcvd_wrapper
1045 #define	udp6_recvoob	udp6_recvoob_wrapper
1046 #define	udp6_send	udp6_send_wrapper
1047 #define	udp6_sendoob	udp6_sendoob_wrapper
1048 #define	udp6_purgeif	udp6_purgeif_wrapper
1049 #define	udp6_usrreq	udp6_usrreq_wrapper
1050 
1051 const struct pr_usrreqs udp6_usrreqs = {
1052 	.pr_attach	= udp6_attach,
1053 	.pr_detach	= udp6_detach,
1054 	.pr_accept	= udp6_accept,
1055 	.pr_bind	= udp6_bind,
1056 	.pr_listen	= udp6_listen,
1057 	.pr_connect	= udp6_connect,
1058 	.pr_connect2	= udp6_connect2,
1059 	.pr_disconnect	= udp6_disconnect,
1060 	.pr_shutdown	= udp6_shutdown,
1061 	.pr_abort	= udp6_abort,
1062 	.pr_ioctl	= udp6_ioctl,
1063 	.pr_stat	= udp6_stat,
1064 	.pr_peeraddr	= udp6_peeraddr,
1065 	.pr_sockaddr	= udp6_sockaddr,
1066 	.pr_rcvd	= udp6_rcvd,
1067 	.pr_recvoob	= udp6_recvoob,
1068 	.pr_send	= udp6_send,
1069 	.pr_sendoob	= udp6_sendoob,
1070 	.pr_purgeif	= udp6_purgeif,
1071 	.pr_generic	= udp6_usrreq,
1072 };
1073