xref: /freebsd/sys/netinet6/udp6_usrreq.c (revision b28624fde638caadd4a89f50c9b7e7da0f98c4d2)
1 /*	$KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei Exp $	*/
2 /*	$KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei 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, 1988, 1990, 1993, 1995
35  *	The Regents of the University of California.
36  * 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  * 4. 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_usrreq.c	8.6 (Berkeley) 5/23/95
63  * $FreeBSD$
64  */
65 
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipsec.h"
69 #include "opt_mac.h"
70 
71 #include <sys/param.h>
72 #include <sys/kernel.h>
73 #include <sys/lock.h>
74 #include <sys/mbuf.h>
75 #include <sys/priv.h>
76 #include <sys/proc.h>
77 #include <sys/protosw.h>
78 #include <sys/signalvar.h>
79 #include <sys/socket.h>
80 #include <sys/socketvar.h>
81 #include <sys/sx.h>
82 #include <sys/sysctl.h>
83 #include <sys/syslog.h>
84 #include <sys/systm.h>
85 
86 #include <net/if.h>
87 #include <net/if_types.h>
88 #include <net/route.h>
89 
90 #include <netinet/in.h>
91 #include <netinet/in_pcb.h>
92 #include <netinet/in_systm.h>
93 #include <netinet/in_var.h>
94 #include <netinet/ip.h>
95 #include <netinet/ip_icmp.h>
96 #include <netinet/ip6.h>
97 #include <netinet/icmp_var.h>
98 #include <netinet/icmp6.h>
99 #include <netinet/ip_var.h>
100 #include <netinet/udp.h>
101 #include <netinet/udp_var.h>
102 #include <netinet6/ip6protosw.h>
103 #include <netinet6/ip6_var.h>
104 #include <netinet6/in6_pcb.h>
105 #include <netinet6/udp6_var.h>
106 #include <netinet6/scope6_var.h>
107 
108 #ifdef IPSEC
109 #include <netipsec/ipsec.h>
110 #include <netipsec/ipsec6.h>
111 #endif /* IPSEC */
112 
113 #include <security/mac/mac_framework.h>
114 
115 /*
116  * UDP protocol implementation.
117  * Per RFC 768, August, 1980.
118  */
119 
120 extern struct protosw	inetsw[];
121 static void		udp6_detach(struct socket *so);
122 
123 static void
124 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
125     struct sockaddr_in6 *fromsa)
126 {
127 	struct socket *so;
128 	struct mbuf *opts;
129 
130 	INP_LOCK_ASSERT(inp);
131 
132 #ifdef IPSEC
133 	/* Check AH/ESP integrity. */
134 	if (ipsec6_in_reject(n, inp)) {
135 		m_freem(n);
136 		ipsec6stat.in_polvio++;
137 		return;
138 	}
139 #endif /* IPSEC */
140 #ifdef MAC
141 	if (mac_check_inpcb_deliver(inp, n) != 0) {
142 		m_freem(n);
143 		return;
144 	}
145 #endif
146 	opts = NULL;
147 	if (inp->in6p_flags & IN6P_CONTROLOPTS ||
148 	    inp->inp_socket->so_options & SO_TIMESTAMP)
149 		ip6_savecontrol(inp, n, &opts);
150 	m_adj(n, off + sizeof(struct udphdr));
151 
152 	so = inp->inp_socket;
153 	SOCKBUF_LOCK(&so->so_rcv);
154 	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
155 	    opts) == 0) {
156 		SOCKBUF_UNLOCK(&so->so_rcv);
157 		m_freem(n);
158 		if (opts)
159 			m_freem(opts);
160 		udpstat.udps_fullsock++;
161 	} else
162 		sorwakeup_locked(so);
163 }
164 
165 int
166 udp6_input(struct mbuf **mp, int *offp, int proto)
167 {
168 	struct mbuf *m = *mp;
169 	struct ip6_hdr *ip6;
170 	struct udphdr *uh;
171 	struct inpcb *inp;
172 	int off = *offp;
173 	int plen, ulen;
174 	struct sockaddr_in6 fromsa;
175 
176 	ip6 = mtod(m, struct ip6_hdr *);
177 
178 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
179 		/* XXX send icmp6 host/port unreach? */
180 		m_freem(m);
181 		return (IPPROTO_DONE);
182 	}
183 
184 #ifndef PULLDOWN_TEST
185 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
186 	ip6 = mtod(m, struct ip6_hdr *);
187 	uh = (struct udphdr *)((caddr_t)ip6 + off);
188 #else
189 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
190 	if (!uh)
191 		return (IPPROTO_DONE);
192 #endif
193 
194 	udpstat.udps_ipackets++;
195 
196 	/*
197 	 * Destination port of 0 is illegal, based on RFC768.
198 	 */
199 	if (uh->uh_dport == 0)
200 		goto badunlocked;
201 
202 	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
203 	ulen = ntohs((u_short)uh->uh_ulen);
204 
205 	if (plen != ulen) {
206 		udpstat.udps_badlen++;
207 		goto badunlocked;
208 	}
209 
210 	/*
211 	 * Checksum extended UDP header and data.
212 	 */
213 	if (uh->uh_sum == 0) {
214 		udpstat.udps_nosum++;
215 		goto badunlocked;
216 	}
217 	if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
218 		udpstat.udps_badsum++;
219 		goto badunlocked;
220 	}
221 
222 	/*
223 	 * Construct sockaddr format source address.
224 	 */
225 	init_sin6(&fromsa, m);
226 	fromsa.sin6_port = uh->uh_sport;
227 
228 	INP_INFO_RLOCK(&udbinfo);
229 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
230 		struct inpcb *last;
231 
232 		/*
233 		 * In the event that laddr should be set to the link-local
234 		 * address (this happens in RIPng), the multicast address
235 		 * specified in the received packet will not match laddr.  To
236 		 * handle this situation, matching is relaxed if the
237 		 * receiving interface is the same as one specified in the
238 		 * socket and if the destination multicast address matches
239 		 * one of the multicast groups specified in the socket.
240 		 */
241 
242 		/*
243 		 * KAME note: traditionally we dropped udpiphdr from mbuf
244 		 * here.  We need udphdr for IPsec processing so we do that
245 		 * later.
246 		 */
247 		last = NULL;
248 		LIST_FOREACH(inp, &udb, inp_list) {
249 			if ((inp->inp_vflag & INP_IPV6) == 0)
250 				continue;
251 			if (inp->in6p_lport != uh->uh_dport)
252 				continue;
253 			/*
254 			 * XXX: Do not check source port of incoming datagram
255 			 * unless inp_connect() has been called to bind the
256 			 * fport part of the 4-tuple; the source could be
257 			 * trying to talk to us with an ephemeral port.
258 			 */
259 			if (inp->inp_fport != 0 &&
260 			    inp->inp_fport != uh->uh_sport)
261 				continue;
262 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
263 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
264 							&ip6->ip6_dst))
265 					continue;
266 			}
267 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
268 				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
269 							&ip6->ip6_src) ||
270 				    inp->in6p_fport != uh->uh_sport)
271 					continue;
272 			}
273 
274 			if (last != NULL) {
275 				struct mbuf *n;
276 
277 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
278 					INP_LOCK(last);
279 					udp6_append(last, n, off, &fromsa);
280 					INP_UNLOCK(last);
281 				}
282 			}
283 			last = inp;
284 			/*
285 			 * Don't look for additional matches if this one does
286 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
287 			 * socket options set.  This heuristic avoids
288 			 * searching through all pcbs in the common case of a
289 			 * non-shared port.  It assumes that an application
290 			 * will never clear these options after setting them.
291 			 */
292 			if ((last->inp_socket->so_options &
293 			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
294 				break;
295 		}
296 
297 		if (last == NULL) {
298 			/*
299 			 * No matching pcb found; discard datagram.  (No need
300 			 * to send an ICMP Port Unreachable for a broadcast
301 			 * or multicast datgram.)
302 			 */
303 			udpstat.udps_noport++;
304 			udpstat.udps_noportmcast++;
305 			goto badheadlocked;
306 		}
307 		INP_LOCK(last);
308 		udp6_append(last, m, off, &fromsa);
309 		INP_UNLOCK(last);
310 		INP_INFO_RUNLOCK(&udbinfo);
311 		return (IPPROTO_DONE);
312 	}
313 	/*
314 	 * Locate pcb for datagram.
315 	 */
316 	inp = in6_pcblookup_hash(&udbinfo, &ip6->ip6_src, uh->uh_sport,
317 	    &ip6->ip6_dst, uh->uh_dport, 1, m->m_pkthdr.rcvif);
318 	if (inp == NULL) {
319 		if (udp_log_in_vain) {
320 			char ip6bufs[INET6_ADDRSTRLEN];
321 			char ip6bufd[INET6_ADDRSTRLEN];
322 
323 			log(LOG_INFO,
324 			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
325 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
326 			    ntohs(uh->uh_dport),
327 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
328 			    ntohs(uh->uh_sport));
329 		}
330 		udpstat.udps_noport++;
331 		if (m->m_flags & M_MCAST) {
332 			printf("UDP6: M_MCAST is set in a unicast packet.\n");
333 			udpstat.udps_noportmcast++;
334 			goto badheadlocked;
335 		}
336 		INP_INFO_RUNLOCK(&udbinfo);
337 		if (udp_blackhole)
338 			goto badunlocked;
339 		if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
340 			goto badunlocked;
341 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
342 		return (IPPROTO_DONE);
343 	}
344 	INP_LOCK(inp);
345 	udp6_append(inp, m, off, &fromsa);
346 	INP_UNLOCK(inp);
347 	INP_INFO_RUNLOCK(&udbinfo);
348 	return (IPPROTO_DONE);
349 
350 badheadlocked:
351 	INP_INFO_RUNLOCK(&udbinfo);
352 badunlocked:
353 	if (m)
354 		m_freem(m);
355 	return (IPPROTO_DONE);
356 }
357 
358 void
359 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
360 {
361 	struct udphdr uh;
362 	struct ip6_hdr *ip6;
363 	struct mbuf *m;
364 	int off = 0;
365 	struct ip6ctlparam *ip6cp = NULL;
366 	const struct sockaddr_in6 *sa6_src = NULL;
367 	void *cmdarg;
368 	struct inpcb *(*notify) __P((struct inpcb *, int)) = udp_notify;
369 	struct udp_portonly {
370 		u_int16_t uh_sport;
371 		u_int16_t uh_dport;
372 	} *uhp;
373 
374 	if (sa->sa_family != AF_INET6 ||
375 	    sa->sa_len != sizeof(struct sockaddr_in6))
376 		return;
377 
378 	if ((unsigned)cmd >= PRC_NCMDS)
379 		return;
380 	if (PRC_IS_REDIRECT(cmd))
381 		notify = in6_rtchange, d = NULL;
382 	else if (cmd == PRC_HOSTDEAD)
383 		d = NULL;
384 	else if (inet6ctlerrmap[cmd] == 0)
385 		return;
386 
387 	/* if the parameter is from icmp6, decode it. */
388 	if (d != NULL) {
389 		ip6cp = (struct ip6ctlparam *)d;
390 		m = ip6cp->ip6c_m;
391 		ip6 = ip6cp->ip6c_ip6;
392 		off = ip6cp->ip6c_off;
393 		cmdarg = ip6cp->ip6c_cmdarg;
394 		sa6_src = ip6cp->ip6c_src;
395 	} else {
396 		m = NULL;
397 		ip6 = NULL;
398 		cmdarg = NULL;
399 		sa6_src = &sa6_any;
400 	}
401 
402 	if (ip6) {
403 		/*
404 		 * XXX: We assume that when IPV6 is non NULL,
405 		 * M and OFF are valid.
406 		 */
407 
408 		/* Check if we can safely examine src and dst ports. */
409 		if (m->m_pkthdr.len < off + sizeof(*uhp))
410 			return;
411 
412 		bzero(&uh, sizeof(uh));
413 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
414 
415 		(void) in6_pcbnotify(&udbinfo, sa, uh.uh_dport,
416 		    (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
417 		    cmdarg, notify);
418 	} else
419 		(void) in6_pcbnotify(&udbinfo, sa, 0,
420 		    (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
421 }
422 
423 static int
424 udp6_getcred(SYSCTL_HANDLER_ARGS)
425 {
426 	struct xucred xuc;
427 	struct sockaddr_in6 addrs[2];
428 	struct inpcb *inp;
429 	int error;
430 
431 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
432 	if (error)
433 		return (error);
434 
435 	if (req->newlen != sizeof(addrs))
436 		return (EINVAL);
437 	if (req->oldlen != sizeof(struct xucred))
438 		return (EINVAL);
439 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
440 	if (error)
441 		return (error);
442 	if ((error = sa6_embedscope(&addrs[0], ip6_use_defzone)) != 0 ||
443 	    (error = sa6_embedscope(&addrs[1], ip6_use_defzone)) != 0) {
444 		return (error);
445 	}
446 	INP_INFO_RLOCK(&udbinfo);
447 	inp = in6_pcblookup_hash(&udbinfo, &addrs[1].sin6_addr,
448 	    addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port, 1,
449 	    NULL);
450 	if (inp == NULL) {
451 		INP_INFO_RUNLOCK(&udbinfo);
452 		return (ENOENT);
453 	}
454 	INP_LOCK(inp);
455 	if (inp->inp_socket == NULL) {
456 		error = ENOENT;
457 		goto out;
458 	}
459 	error = cr_canseesocket(req->td->td_ucred, inp->inp_socket);
460 	if (error)
461 		goto out;
462 	cru2x(inp->inp_socket->so_cred, &xuc);
463 out:
464 	INP_UNLOCK(inp);
465 	INP_INFO_RUNLOCK(&udbinfo);
466 	if (error == 0)
467 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
468 	return (error);
469 }
470 
471 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
472     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
473 
474 static int
475 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
476     struct mbuf *control, struct thread *td)
477 {
478 	u_int32_t ulen = m->m_pkthdr.len;
479 	u_int32_t plen = sizeof(struct udphdr) + ulen;
480 	struct ip6_hdr *ip6;
481 	struct udphdr *udp6;
482 	struct in6_addr *laddr, *faddr;
483 	struct sockaddr_in6 *sin6 = NULL;
484 	struct ifnet *oifp = NULL;
485 	int scope_ambiguous = 0;
486 	u_short fport;
487 	int error = 0;
488 	struct ip6_pktopts *optp, opt;
489 	int priv;
490 	int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
491 	int flags;
492 	struct sockaddr_in6 tmp;
493 
494 	INP_LOCK_ASSERT(inp);
495 
496 	priv = 0;
497 	if (td && !suser(td))
498 		priv = 1;
499 
500 	if (addr6) {
501 		/* addr6 has been validated in udp6_send(). */
502 		sin6 = (struct sockaddr_in6 *)addr6;
503 
504 		/* protect *sin6 from overwrites */
505 		tmp = *sin6;
506 		sin6 = &tmp;
507 
508 		/*
509 		 * Application should provide a proper zone ID or the use of
510 		 * default zone IDs should be enabled.  Unfortunately, some
511 		 * applications do not behave as it should, so we need a
512 		 * workaround.  Even if an appropriate ID is not determined,
513 		 * we'll see if we can determine the outgoing interface.  If we
514 		 * can, determine the zone ID based on the interface below.
515 		 */
516 		if (sin6->sin6_scope_id == 0 && !ip6_use_defzone)
517 			scope_ambiguous = 1;
518 		if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
519 			return (error);
520 	}
521 
522 	if (control) {
523 		if ((error = ip6_setpktopts(control, &opt,
524 		    inp->in6p_outputopts, priv, IPPROTO_UDP)) != 0)
525 			goto release;
526 		optp = &opt;
527 	} else
528 		optp = inp->in6p_outputopts;
529 
530 	if (sin6) {
531 		faddr = &sin6->sin6_addr;
532 
533 		/*
534 		 * IPv4 version of udp_output calls in_pcbconnect in this case,
535 		 * which needs splnet and affects performance.
536 		 * Since we saw no essential reason for calling in_pcbconnect,
537 		 * we get rid of such kind of logic, and call in6_selectsrc
538 		 * and in6_pcbsetport in order to fill in the local address
539 		 * and the local port.
540 		 */
541 		if (sin6->sin6_port == 0) {
542 			error = EADDRNOTAVAIL;
543 			goto release;
544 		}
545 
546 		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
547 			/* how about ::ffff:0.0.0.0 case? */
548 			error = EISCONN;
549 			goto release;
550 		}
551 
552 		fport = sin6->sin6_port; /* allow 0 port */
553 
554 		if (IN6_IS_ADDR_V4MAPPED(faddr)) {
555 			if ((inp->in6p_flags & IN6P_IPV6_V6ONLY)) {
556 				/*
557 				 * I believe we should explicitly discard the
558 				 * packet when mapped addresses are disabled,
559 				 * rather than send the packet as an IPv6 one.
560 				 * If we chose the latter approach, the packet
561 				 * might be sent out on the wire based on the
562 				 * default route, the situation which we'd
563 				 * probably want to avoid.
564 				 * (20010421 jinmei@kame.net)
565 				 */
566 				error = EINVAL;
567 				goto release;
568 			}
569 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
570 			    !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
571 				/*
572 				 * when remote addr is an IPv4-mapped address,
573 				 * local addr should not be an IPv6 address,
574 				 * since you cannot determine how to map IPv6
575 				 * source address to IPv4.
576 				 */
577 				error = EINVAL;
578 				goto release;
579 			}
580 
581 			af = AF_INET;
582 		}
583 
584 		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
585 			laddr = in6_selectsrc(sin6, optp, inp->in6p_moptions,
586 			    NULL, &inp->in6p_laddr, &oifp, &error);
587 			if (oifp && scope_ambiguous &&
588 			    (error = in6_setscope(&sin6->sin6_addr,
589 			    oifp, NULL))) {
590 				goto release;
591 			}
592 		} else
593 			laddr = &inp->in6p_laddr;	/* XXX */
594 		if (laddr == NULL) {
595 			if (error == 0)
596 				error = EADDRNOTAVAIL;
597 			goto release;
598 		}
599 		if (inp->in6p_lport == 0 &&
600 		    (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0)
601 			goto release;
602 	} else {
603 		if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
604 			error = ENOTCONN;
605 			goto release;
606 		}
607 		if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
608 			if ((inp->in6p_flags & IN6P_IPV6_V6ONLY)) {
609 				/*
610 				 * XXX: this case would happen when the
611 				 * application sets the V6ONLY flag after
612 				 * connecting the foreign address.
613 				 * Such applications should be fixed,
614 				 * so we bark here.
615 				 */
616 				log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
617 				    "option was set for a connected socket\n");
618 				error = EINVAL;
619 				goto release;
620 			} else
621 				af = AF_INET;
622 		}
623 		laddr = &inp->in6p_laddr;
624 		faddr = &inp->in6p_faddr;
625 		fport = inp->in6p_fport;
626 	}
627 
628 	if (af == AF_INET)
629 		hlen = sizeof(struct ip);
630 
631 	/*
632 	 * Calculate data length and get a mbuf
633 	 * for UDP and IP6 headers.
634 	 */
635 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
636 	if (m == 0) {
637 		error = ENOBUFS;
638 		goto release;
639 	}
640 
641 	/*
642 	 * Stuff checksum and output datagram.
643 	 */
644 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
645 	udp6->uh_sport = inp->in6p_lport; /* lport is always set in the PCB */
646 	udp6->uh_dport = fport;
647 	if (plen <= 0xffff)
648 		udp6->uh_ulen = htons((u_short)plen);
649 	else
650 		udp6->uh_ulen = 0;
651 	udp6->uh_sum = 0;
652 
653 	switch (af) {
654 	case AF_INET6:
655 		ip6 = mtod(m, struct ip6_hdr *);
656 		ip6->ip6_flow	= inp->in6p_flowinfo & IPV6_FLOWINFO_MASK;
657 		ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
658 		ip6->ip6_vfc	|= IPV6_VERSION;
659 #if 0				/* ip6_plen will be filled in ip6_output. */
660 		ip6->ip6_plen	= htons((u_short)plen);
661 #endif
662 		ip6->ip6_nxt	= IPPROTO_UDP;
663 		ip6->ip6_hlim	= in6_selecthlim(inp, NULL);
664 		ip6->ip6_src	= *laddr;
665 		ip6->ip6_dst	= *faddr;
666 
667 		if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
668 				sizeof(struct ip6_hdr), plen)) == 0) {
669 			udp6->uh_sum = 0xffff;
670 		}
671 
672 		flags = 0;
673 
674 		udpstat.udps_opackets++;
675 		error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
676 		    NULL, inp);
677 		break;
678 	case AF_INET:
679 		error = EAFNOSUPPORT;
680 		goto release;
681 	}
682 	goto releaseopt;
683 
684 release:
685 	m_freem(m);
686 
687 releaseopt:
688 	if (control) {
689 		ip6_clearpktopts(&opt, -1);
690 		m_freem(control);
691 	}
692 	return (error);
693 }
694 
695 static void
696 udp6_abort(struct socket *so)
697 {
698 	struct inpcb *inp;
699 
700 	inp = sotoinpcb(so);
701 	KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
702 
703 #ifdef INET
704 	if (inp->inp_vflag & INP_IPV4) {
705 		struct pr_usrreqs *pru;
706 
707 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
708 		(*pru->pru_abort)(so);
709 		return;
710 	}
711 #endif
712 
713 	INP_INFO_WLOCK(&udbinfo);
714 	INP_LOCK(inp);
715 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
716 		in6_pcbdisconnect(inp);
717 		inp->in6p_laddr = in6addr_any;
718 		soisdisconnected(so);
719 	}
720 	INP_UNLOCK(inp);
721 	INP_INFO_WUNLOCK(&udbinfo);
722 }
723 
724 static int
725 udp6_attach(struct socket *so, int proto, struct thread *td)
726 {
727 	struct inpcb *inp;
728 	int error;
729 
730 	inp = sotoinpcb(so);
731 	KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
732 
733 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
734 		error = soreserve(so, udp_sendspace, udp_recvspace);
735 		if (error)
736 			return (error);
737 	}
738 	INP_INFO_WLOCK(&udbinfo);
739 	error = in_pcballoc(so, &udbinfo);
740 	if (error) {
741 		INP_INFO_WUNLOCK(&udbinfo);
742 		return (error);
743 	}
744 	inp = (struct inpcb *)so->so_pcb;
745 	INP_INFO_WUNLOCK(&udbinfo);
746 	inp->inp_vflag |= INP_IPV6;
747 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
748 		inp->inp_vflag |= INP_IPV4;
749 	inp->in6p_hops = -1;	/* use kernel default */
750 	inp->in6p_cksum = -1;	/* just to be sure */
751 	/*
752 	 * XXX: ugly!!
753 	 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
754 	 * because the socket may be bound to an IPv6 wildcard address,
755 	 * which may match an IPv4-mapped IPv6 address.
756 	 */
757 	inp->inp_ip_ttl = ip_defttl;
758 	INP_UNLOCK(inp);
759 	return (0);
760 }
761 
762 static int
763 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
764 {
765 	struct inpcb *inp;
766 	int error;
767 
768 	inp = sotoinpcb(so);
769 	KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
770 
771 	INP_INFO_WLOCK(&udbinfo);
772 	INP_LOCK(inp);
773 	inp->inp_vflag &= ~INP_IPV4;
774 	inp->inp_vflag |= INP_IPV6;
775 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
776 		struct sockaddr_in6 *sin6_p;
777 
778 		sin6_p = (struct sockaddr_in6 *)nam;
779 
780 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
781 			inp->inp_vflag |= INP_IPV4;
782 		else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
783 			struct sockaddr_in sin;
784 
785 			in6_sin6_2_sin(&sin, sin6_p);
786 			inp->inp_vflag |= INP_IPV4;
787 			inp->inp_vflag &= ~INP_IPV6;
788 			error = in_pcbbind(inp, (struct sockaddr *)&sin,
789 			    td->td_ucred);
790 			goto out;
791 		}
792 	}
793 
794 	error = in6_pcbbind(inp, nam, td->td_ucred);
795 out:
796 	INP_UNLOCK(inp);
797 	INP_INFO_WUNLOCK(&udbinfo);
798 	return (error);
799 }
800 
801 static void
802 udp6_close(struct socket *so)
803 {
804 	struct inpcb *inp;
805 
806 	inp = sotoinpcb(so);
807 	KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
808 
809 #ifdef INET
810 	if (inp->inp_vflag & INP_IPV4) {
811 		struct pr_usrreqs *pru;
812 
813 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
814 		(*pru->pru_disconnect)(so);
815 		return;
816 	}
817 #endif
818 	INP_INFO_WLOCK(&udbinfo);
819 	INP_LOCK(inp);
820 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
821 		in6_pcbdisconnect(inp);
822 		inp->in6p_laddr = in6addr_any;
823 		soisdisconnected(so);
824 	}
825 	INP_UNLOCK(inp);
826 	INP_INFO_WUNLOCK(&udbinfo);
827 }
828 
829 static int
830 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
831 {
832 	struct inpcb *inp;
833 	int error;
834 
835 	inp = sotoinpcb(so);
836 	KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
837 
838 	INP_INFO_WLOCK(&udbinfo);
839 	INP_LOCK(inp);
840 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
841 		struct sockaddr_in6 *sin6_p;
842 
843 		sin6_p = (struct sockaddr_in6 *)nam;
844 		if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
845 			struct sockaddr_in sin;
846 
847 			if (inp->inp_faddr.s_addr != INADDR_ANY) {
848 				error = EISCONN;
849 				goto out;
850 			}
851 			in6_sin6_2_sin(&sin, sin6_p);
852 			error = in_pcbconnect(inp, (struct sockaddr *)&sin,
853 			    td->td_ucred);
854 			if (error == 0) {
855 				inp->inp_vflag |= INP_IPV4;
856 				inp->inp_vflag &= ~INP_IPV6;
857 				soisconnected(so);
858 			}
859 			goto out;
860 		}
861 	}
862 	if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
863 		error = EISCONN;
864 		goto out;
865 	}
866 	error = in6_pcbconnect(inp, nam, td->td_ucred);
867 	if (error == 0) {
868 		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
869 			/* should be non mapped addr */
870 			inp->inp_vflag &= ~INP_IPV4;
871 			inp->inp_vflag |= INP_IPV6;
872 		}
873 		soisconnected(so);
874 	}
875 out:
876 	INP_UNLOCK(inp);
877 	INP_INFO_WUNLOCK(&udbinfo);
878 	return (error);
879 }
880 
881 static void
882 udp6_detach(struct socket *so)
883 {
884 	struct inpcb *inp;
885 
886 	inp = sotoinpcb(so);
887 	KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
888 
889 	INP_INFO_WLOCK(&udbinfo);
890 	INP_LOCK(inp);
891 	in6_pcbdetach(inp);
892 	in6_pcbfree(inp);
893 	INP_INFO_WUNLOCK(&udbinfo);
894 }
895 
896 static int
897 udp6_disconnect(struct socket *so)
898 {
899 	struct inpcb *inp;
900 	int error;
901 
902 	inp = sotoinpcb(so);
903 	KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
904 
905 	INP_INFO_WLOCK(&udbinfo);
906 	INP_LOCK(inp);
907 
908 #ifdef INET
909 	if (inp->inp_vflag & INP_IPV4) {
910 		struct pr_usrreqs *pru;
911 
912 		pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
913 		error = (*pru->pru_disconnect)(so);
914 		goto out;
915 	}
916 #endif
917 
918 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
919 		error = ENOTCONN;
920 		goto out;
921 	}
922 
923 	in6_pcbdisconnect(inp);
924 	inp->in6p_laddr = in6addr_any;
925 	/* XXXRW: so_state locking? */
926 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
927 out:
928 	INP_UNLOCK(inp);
929 	INP_INFO_WUNLOCK(&udbinfo);
930 	return (0);
931 }
932 
933 static int
934 udp6_send(struct socket *so, int flags, struct mbuf *m,
935     struct sockaddr *addr, struct mbuf *control, struct thread *td)
936 {
937 	struct inpcb *inp;
938 	int error = 0;
939 
940 	inp = sotoinpcb(so);
941 	KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
942 
943 	INP_INFO_WLOCK(&udbinfo);
944 	INP_LOCK(inp);
945 	if (addr) {
946 		if (addr->sa_len != sizeof(struct sockaddr_in6)) {
947 			error = EINVAL;
948 			goto bad;
949 		}
950 		if (addr->sa_family != AF_INET6) {
951 			error = EAFNOSUPPORT;
952 			goto bad;
953 		}
954 	}
955 
956 #ifdef INET
957 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
958 		int hasv4addr;
959 		struct sockaddr_in6 *sin6 = 0;
960 
961 		if (addr == 0)
962 			hasv4addr = (inp->inp_vflag & INP_IPV4);
963 		else {
964 			sin6 = (struct sockaddr_in6 *)addr;
965 			hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
966 			    ? 1 : 0;
967 		}
968 		if (hasv4addr) {
969 			struct pr_usrreqs *pru;
970 
971 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
972 			    !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
973 				/*
974 				 * When remote addr is IPv4-mapped address,
975 				 * local addr should not be an IPv6 address;
976 				 * since you cannot determine how to map IPv6
977 				 * source address to IPv4.
978 				 */
979 				error = EINVAL;
980 				goto out;
981 			}
982 			if (sin6)
983 				in6_sin6_2_sin_in_sock(addr);
984 			pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
985 			error = ((*pru->pru_send)(so, flags, m, addr, control,
986 			    td));
987 			/* addr will just be freed in sendit(). */
988 			goto out;
989 		}
990 	}
991 #endif
992 #ifdef MAC
993 	mac_create_mbuf_from_inpcb(inp, m);
994 #endif
995 	error = udp6_output(inp, m, addr, control, td);
996 out:
997 	INP_UNLOCK(inp);
998 	INP_INFO_WUNLOCK(&udbinfo);
999 	return (error);
1000 
1001 bad:
1002 	INP_UNLOCK(inp);
1003 	INP_INFO_WUNLOCK(&udbinfo);
1004 	m_freem(m);
1005 	return (error);
1006 }
1007 
1008 struct pr_usrreqs udp6_usrreqs = {
1009 	.pru_abort =		udp6_abort,
1010 	.pru_attach =		udp6_attach,
1011 	.pru_bind =		udp6_bind,
1012 	.pru_connect =		udp6_connect,
1013 	.pru_control =		in6_control,
1014 	.pru_detach =		udp6_detach,
1015 	.pru_disconnect =	udp6_disconnect,
1016 	.pru_peeraddr =		in6_mapped_peeraddr,
1017 	.pru_send =		udp6_send,
1018 	.pru_shutdown =		udp_shutdown,
1019 	.pru_sockaddr =		in6_mapped_sockaddr,
1020 	.pru_sosetlabel =	in_pcbsosetlabel,
1021 	.pru_close =		udp6_close
1022 };
1023