xref: /dragonfly/sys/netinet6/ip6_output.c (revision 755d70b8)
1 /*	$FreeBSD: src/sys/netinet6/ip6_output.c,v 1.13.2.18 2003/01/24 05:11:35 sam Exp $	*/
2 /*	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 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
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  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
62  */
63 
64 #include "opt_ip6fw.h"
65 #include "opt_inet.h"
66 #include "opt_inet6.h"
67 
68 #include <sys/param.h>
69 #include <sys/malloc.h>
70 #include <sys/mbuf.h>
71 #include <sys/errno.h>
72 #include <sys/protosw.h>
73 #include <sys/socket.h>
74 #include <sys/socketvar.h>
75 #include <sys/systm.h>
76 #include <sys/kernel.h>
77 #include <sys/proc.h>
78 #include <sys/priv.h>
79 
80 #include <sys/thread2.h>
81 #include <sys/msgport2.h>
82 
83 #include <net/if.h>
84 #include <net/route.h>
85 #include <net/pfil.h>
86 
87 #include <netinet/in.h>
88 #include <netinet/in_var.h>
89 #include <netinet6/in6_var.h>
90 #include <netinet/ip6.h>
91 #include <netinet/icmp6.h>
92 #include <netinet6/ip6_var.h>
93 #include <netinet/in_pcb.h>
94 #include <netinet6/nd6.h>
95 #include <netinet6/ip6protosw.h>
96 
97 #include <net/ip6fw/ip6_fw.h>
98 
99 #include <net/net_osdep.h>
100 
101 static MALLOC_DEFINE(M_IPMOPTS, "ip6_moptions", "internet multicast options");
102 
103 struct ip6_exthdrs {
104 	struct mbuf *ip6e_ip6;
105 	struct mbuf *ip6e_hbh;
106 	struct mbuf *ip6e_dest1;
107 	struct mbuf *ip6e_rthdr;
108 	struct mbuf *ip6e_dest2;
109 };
110 
111 static int ip6_pcbopt (int, u_char *, int, struct ip6_pktopts **, int);
112 static int ip6_setpktoption (int, u_char *, int, struct ip6_pktopts *,
113 	int, int, int, int);
114 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *, struct socket *,
115 	struct sockopt *);
116 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
117 static int ip6_setmoptions (int, struct ip6_moptions **, struct mbuf *);
118 static int ip6_getmoptions (int, struct ip6_moptions *, struct mbuf **);
119 static int ip6_getpmtu(struct route_in6 *, struct route_in6 *,
120 	struct ifnet *, struct in6_addr *, u_long *, int *);
121 static int copyexthdr (void *, struct mbuf **);
122 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
123 	struct ip6_frag **);
124 static int ip6_insert_jumboopt (struct ip6_exthdrs *, u_int32_t);
125 static struct mbuf *ip6_splithdr (struct mbuf *);
126 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
127 
128 /*
129  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
130  * header (with pri, len, nxt, hlim, src, dst).
131  * This function may modify ver and hlim only.
132  * The mbuf chain containing the packet will be freed.
133  * The mbuf opt, if present, will not be freed.
134  *
135  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
136  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
137  * which is rt_rmx.rmx_mtu.
138  */
139 int
140 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt, struct route_in6 *ro,
141 	   int flags, struct ip6_moptions *im6o,
142 	   struct ifnet **ifpp,		/* XXX: just for statistics */
143 	   struct inpcb *inp)
144 {
145 	struct ip6_hdr *ip6, *mhip6;
146 	struct ifnet *ifp, *origifp;
147 	struct mbuf *m = m0;
148 	struct mbuf *mprev;
149 	u_char *nexthdrp;
150 	int hlen, tlen, len, off;
151 	struct route_in6 ip6route;
152 	struct sockaddr_in6 *dst;
153 	int error = 0;
154 	struct in6_ifaddr *ia = NULL;
155 	u_long mtu;
156 	int alwaysfrag, dontfrag;
157 	u_int32_t optlen, plen = 0, unfragpartlen;
158 	struct ip6_exthdrs exthdrs;
159 	struct in6_addr finaldst;
160 	struct route_in6 *ro_pmtu = NULL;
161 	boolean_t hdrsplit = FALSE;
162 
163 	bzero(&exthdrs, sizeof exthdrs);
164 
165 	if (opt) {
166 		if ((error = copyexthdr(opt->ip6po_hbh, &exthdrs.ip6e_hbh)))
167 			goto freehdrs;
168 		if ((error = copyexthdr(opt->ip6po_dest1, &exthdrs.ip6e_dest1)))
169 			goto freehdrs;
170 		if ((error = copyexthdr(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr)))
171 			goto freehdrs;
172 		if ((error = copyexthdr(opt->ip6po_dest2, &exthdrs.ip6e_dest2)))
173 			goto freehdrs;
174 	}
175 
176 	/*
177 	 * Calculate the total length of the extension header chain.
178 	 * Keep the length of the unfragmentable part for fragmentation.
179 	 */
180 	optlen = m_lengthm(exthdrs.ip6e_hbh, NULL) +
181 	    m_lengthm(exthdrs.ip6e_dest1, NULL) +
182 	    m_lengthm(exthdrs.ip6e_rthdr, NULL);
183 
184 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
185 
186 	/* NOTE: we don't add AH/ESP length here. do that later. */
187 	optlen += m_lengthm(exthdrs.ip6e_dest2, NULL);
188 
189 	/*
190 	 * If there is at least one extension header,
191 	 * separate IP6 header from the payload.
192 	 */
193 	if (optlen && !hdrsplit) {
194 		exthdrs.ip6e_ip6 = ip6_splithdr(m);
195 		if (exthdrs.ip6e_ip6 == NULL) {
196 			error = ENOBUFS;
197 			goto freehdrs;
198 		}
199 		m = exthdrs.ip6e_ip6;
200 		hdrsplit = TRUE;
201 	}
202 
203 	/* adjust pointer */
204 	ip6 = mtod(m, struct ip6_hdr *);
205 
206 	/* adjust mbuf packet header length */
207 	m->m_pkthdr.len += optlen;
208 	plen = m->m_pkthdr.len - sizeof(*ip6);
209 
210 	/* If this is a jumbo payload, insert a jumbo payload option. */
211 	if (plen > IPV6_MAXPACKET) {
212 		if (!hdrsplit) {
213 			exthdrs.ip6e_ip6 = ip6_splithdr(m);
214 			if (exthdrs.ip6e_ip6 == NULL) {
215 				error = ENOBUFS;
216 				goto freehdrs;
217 			}
218 			m = exthdrs.ip6e_ip6;
219 			hdrsplit = TRUE;
220 		}
221 		/* adjust pointer */
222 		ip6 = mtod(m, struct ip6_hdr *);
223 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
224 			goto freehdrs;
225 		ip6->ip6_plen = 0;
226 	} else
227 		ip6->ip6_plen = htons(plen);
228 
229 	/*
230 	 * Concatenate headers and fill in next header fields.
231 	 * Here we have, on "m"
232 	 *	IPv6 payload
233 	 * and we insert headers accordingly.  Finally, we should be getting:
234 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
235 	 *
236 	 * during the header composing process, "m" points to IPv6 header.
237 	 * "mprev" points to an extension header prior to esp.
238 	 */
239 
240 	nexthdrp = &ip6->ip6_nxt;
241 	mprev = m;
242 
243 	/*
244 	 * we treat dest2 specially. the goal here is to make mprev point the
245 	 * mbuf prior to dest2.
246 	 *
247 	 * result: IPv6 dest2 payload
248 	 * m and mprev will point to IPv6 header.
249 	 */
250 	if (exthdrs.ip6e_dest2) {
251 		if (!hdrsplit)
252 			panic("assumption failed: hdr not split");
253 		exthdrs.ip6e_dest2->m_next = m->m_next;
254 		m->m_next = exthdrs.ip6e_dest2;
255 		*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
256 		ip6->ip6_nxt = IPPROTO_DSTOPTS;
257 	}
258 
259 /*
260  * Place m1 after mprev.
261  */
262 #define MAKE_CHAIN(m1, mprev, nexthdrp, i)\
263     do {\
264 	if (m1) {\
265 		if (!hdrsplit)\
266 			panic("assumption failed: hdr not split");\
267 		*mtod(m1, u_char *) = *nexthdrp;\
268 		*nexthdrp = (i);\
269 		nexthdrp = mtod(m1, u_char *);\
270 		m1->m_next = mprev->m_next;\
271 		mprev->m_next = m1;\
272 		mprev = m1;\
273 	}\
274     } while (0)
275 
276 	/*
277 	 * result: IPv6 hbh dest1 rthdr dest2 payload
278 	 * m will point to IPv6 header.  mprev will point to the
279 	 * extension header prior to dest2 (rthdr in the above case).
280 	 */
281 	MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
282 	MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp, IPPROTO_DSTOPTS);
283 	MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp, IPPROTO_ROUTING);
284 
285 	/*
286 	 * If there is a routing header, replace the destination address field
287 	 * with the first hop of the routing header.
288 	 */
289 	if (exthdrs.ip6e_rthdr) {
290 		struct ip6_rthdr *rh;
291 
292 		finaldst = ip6->ip6_dst;
293 		rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
294 		switch (rh->ip6r_type) {
295 		default:	/* is it possible? */
296 			 error = EINVAL;
297 			 goto bad;
298 		}
299 	}
300 
301 	/* Source address validation */
302 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
303 	    !(flags & IPV6_DADOUTPUT)) {
304 		error = EOPNOTSUPP;
305 		ip6stat.ip6s_badscope++;
306 		goto bad;
307 	}
308 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
309 		error = EOPNOTSUPP;
310 		ip6stat.ip6s_badscope++;
311 		goto bad;
312 	}
313 
314 	ip6stat.ip6s_localout++;
315 
316 	/*
317 	 * Route packet.
318 	 */
319 	if (ro == NULL) {
320 		ro = &ip6route;
321 		bzero(ro, sizeof(*ro));
322 	}
323 	ro_pmtu = ro;
324 	if (opt && opt->ip6po_rthdr)
325 		ro = &opt->ip6po_route;
326 	dst = (struct sockaddr_in6 *)&ro->ro_dst;
327 
328 	/*
329 	 * If there is a cached route,
330 	 * check that it is to the same destination
331 	 * and is still up. If not, free it and try again.
332 	 */
333 	if (ro->ro_rt != NULL &&
334 	    (!(ro->ro_rt->rt_flags & RTF_UP) || dst->sin6_family != AF_INET6 ||
335 	     !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_dst))) {
336 		RTFREE(ro->ro_rt);
337 		ro->ro_rt = NULL;
338 	}
339 	if (ro->ro_rt == NULL) {
340 		bzero(dst, sizeof(*dst));
341 		dst->sin6_family = AF_INET6;
342 		dst->sin6_len = sizeof(struct sockaddr_in6);
343 		dst->sin6_addr = ip6->ip6_dst;
344 	}
345 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
346 		/* Unicast */
347 
348 #define ifatoia6(ifa)	((struct in6_ifaddr *)(ifa))
349 #define sin6tosa(sin6)	((struct sockaddr *)(sin6))
350 		/* xxx
351 		 * interface selection comes here
352 		 * if an interface is specified from an upper layer,
353 		 * ifp must point it.
354 		 */
355 		if (ro->ro_rt == NULL) {
356 			/*
357 			 * non-bsdi always clone routes, if parent is
358 			 * PRF_CLONING.
359 			 */
360 			rtalloc((struct route *)ro);
361 		}
362 		if (ro->ro_rt == NULL) {
363 			ip6stat.ip6s_noroute++;
364 			error = EHOSTUNREACH;
365 			/* XXX in6_ifstat_inc(ifp, ifs6_out_discard); */
366 			goto bad;
367 		}
368 		ia = ifatoia6(ro->ro_rt->rt_ifa);
369 		ifp = ro->ro_rt->rt_ifp;
370 		ro->ro_rt->rt_use++;
371 		if (ro->ro_rt->rt_flags & RTF_GATEWAY)
372 			dst = (struct sockaddr_in6 *)ro->ro_rt->rt_gateway;
373 		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
374 
375 		in6_ifstat_inc(ifp, ifs6_out_request);
376 
377 		/*
378 		 * Check if the outgoing interface conflicts with
379 		 * the interface specified by ifi6_ifindex (if specified).
380 		 * Note that loopback interface is always okay.
381 		 * (this may happen when we are sending a packet to one of
382 		 *  our own addresses.)
383 		 */
384 		if (opt && opt->ip6po_pktinfo
385 		 && opt->ip6po_pktinfo->ipi6_ifindex) {
386 			if (!(ifp->if_flags & IFF_LOOPBACK)
387 			 && ifp->if_index != opt->ip6po_pktinfo->ipi6_ifindex) {
388 				ip6stat.ip6s_noroute++;
389 				in6_ifstat_inc(ifp, ifs6_out_discard);
390 				error = EHOSTUNREACH;
391 				goto bad;
392 			}
393 		}
394 
395 		if (opt && opt->ip6po_hlim != -1)
396 			ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
397 	} else {
398 		/* Multicast */
399 		struct	in6_multi *in6m;
400 
401 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
402 
403 		/*
404 		 * See if the caller provided any multicast options
405 		 */
406 		ifp = NULL;
407 		if (im6o != NULL) {
408 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
409 			if (im6o->im6o_multicast_ifp != NULL)
410 				ifp = im6o->im6o_multicast_ifp;
411 		} else
412 			ip6->ip6_hlim = ip6_defmcasthlim;
413 
414 		/*
415 		 * See if the caller provided the outgoing interface
416 		 * as an ancillary data.
417 		 * Boundary check for ifindex is assumed to be already done.
418 		 */
419 		if (opt && opt->ip6po_pktinfo && opt->ip6po_pktinfo->ipi6_ifindex)
420 			ifp = ifindex2ifnet[opt->ip6po_pktinfo->ipi6_ifindex];
421 
422 		/*
423 		 * If the destination is a node-local scope multicast,
424 		 * the packet should be loop-backed only.
425 		 */
426 		if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
427 			/*
428 			 * If the outgoing interface is already specified,
429 			 * it should be a loopback interface.
430 			 */
431 			if (ifp && !(ifp->if_flags & IFF_LOOPBACK)) {
432 				ip6stat.ip6s_badscope++;
433 				error = ENETUNREACH; /* XXX: better error? */
434 				/* XXX correct ifp? */
435 				in6_ifstat_inc(ifp, ifs6_out_discard);
436 				goto bad;
437 			} else {
438 				ifp = loif;
439 			}
440 		}
441 
442 		if (opt && opt->ip6po_hlim != -1)
443 			ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
444 
445 		/*
446 		 * If caller did not provide an interface lookup a
447 		 * default in the routing table.  This is either a
448 		 * default for the speicfied group (i.e. a host
449 		 * route), or a multicast default (a route for the
450 		 * ``net'' ff00::/8).
451 		 */
452 		if (ifp == NULL) {
453 			if (ro->ro_rt == NULL) {
454 				ro->ro_rt =
455 				  rtpurelookup((struct sockaddr *)&ro->ro_dst);
456 			}
457 			if (ro->ro_rt == NULL) {
458 				ip6stat.ip6s_noroute++;
459 				error = EHOSTUNREACH;
460 				/* XXX in6_ifstat_inc(ifp, ifs6_out_discard) */
461 				goto bad;
462 			}
463 			ia = ifatoia6(ro->ro_rt->rt_ifa);
464 			ifp = ro->ro_rt->rt_ifp;
465 			ro->ro_rt->rt_use++;
466 		}
467 
468 		if (!(flags & IPV6_FORWARDING))
469 			in6_ifstat_inc(ifp, ifs6_out_request);
470 		in6_ifstat_inc(ifp, ifs6_out_mcast);
471 
472 		/*
473 		 * Confirm that the outgoing interface supports multicast.
474 		 */
475 		if (!(ifp->if_flags & IFF_MULTICAST)) {
476 			ip6stat.ip6s_noroute++;
477 			in6_ifstat_inc(ifp, ifs6_out_discard);
478 			error = ENETUNREACH;
479 			goto bad;
480 		}
481 		in6m = IN6_LOOKUP_MULTI(&ip6->ip6_dst, ifp);
482 		if (in6m != NULL &&
483 		   (im6o == NULL || im6o->im6o_multicast_loop)) {
484 			/*
485 			 * If we belong to the destination multicast group
486 			 * on the outgoing interface, and the caller did not
487 			 * forbid loopback, loop back a copy.
488 			 */
489 			ip6_mloopback(ifp, m, dst);
490 		} else {
491 			/*
492 			 * If we are acting as a multicast router, perform
493 			 * multicast forwarding as if the packet had just
494 			 * arrived on the interface to which we are about
495 			 * to send.  The multicast forwarding function
496 			 * recursively calls this function, using the
497 			 * IPV6_FORWARDING flag to prevent infinite recursion.
498 			 *
499 			 * Multicasts that are looped back by ip6_mloopback(),
500 			 * above, will be forwarded by the ip6_input() routine,
501 			 * if necessary.
502 			 */
503 			if (ip6_mrouter && !(flags & IPV6_FORWARDING)) {
504 				if (ip6_mforward(ip6, ifp, m) != 0) {
505 					m_freem(m);
506 					goto done;
507 				}
508 			}
509 		}
510 		/*
511 		 * Multicasts with a hoplimit of zero may be looped back,
512 		 * above, but must not be transmitted on a network.
513 		 * Also, multicasts addressed to the loopback interface
514 		 * are not sent -- the above call to ip6_mloopback() will
515 		 * loop back a copy if this host actually belongs to the
516 		 * destination group on the loopback interface.
517 		 */
518 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK)) {
519 			m_freem(m);
520 			goto done;
521 		}
522 	}
523 
524 	/*
525 	 * Fill the outgoing inteface to tell the upper layer
526 	 * to increment per-interface statistics.
527 	 */
528 	if (ifpp)
529 		*ifpp = ifp;
530 
531 	/* Determine path MTU. */
532 	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
533 	    &alwaysfrag)) != 0)
534 		goto bad;
535 
536 	/*
537 	 * The caller of this function may specify to use the minimum MTU
538 	 * in some cases.
539 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
540 	 * setting.  The logic is a bit complicated; by default, unicast
541 	 * packets will follow path MTU while multicast packets will be sent at
542 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
543 	 * including unicast ones will be sent at the minimum MTU.  Multicast
544 	 * packets will always be sent at the minimum MTU unless
545 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
546 	 * See RFC 3542 for more details.
547 	 */
548 	if (mtu > IPV6_MMTU) {
549 		if ((flags & IPV6_MINMTU))
550 			mtu = IPV6_MMTU;
551 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
552 			mtu = IPV6_MMTU;
553 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
554 			 (opt == NULL ||
555 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
556 			mtu = IPV6_MMTU;
557 		}
558 	}
559 
560 	/* Fake scoped addresses */
561 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
562 		/*
563 		 * If source or destination address is a scoped address, and
564 		 * the packet is going to be sent to a loopback interface,
565 		 * we should keep the original interface.
566 		 */
567 
568 		/*
569 		 * XXX: this is a very experimental and temporary solution.
570 		 * We eventually have sockaddr_in6 and use the sin6_scope_id
571 		 * field of the structure here.
572 		 * We rely on the consistency between two scope zone ids
573 		 * of source and destination, which should already be assured.
574 		 * Larger scopes than link will be supported in the future.
575 		 */
576 		origifp = NULL;
577 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
578 			origifp = ifindex2ifnet[ntohs(ip6->ip6_src.s6_addr16[1])];
579 		else if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
580 			origifp = ifindex2ifnet[ntohs(ip6->ip6_dst.s6_addr16[1])];
581 		/*
582 		 * XXX: origifp can be NULL even in those two cases above.
583 		 * For example, if we remove the (only) link-local address
584 		 * from the loopback interface, and try to send a link-local
585 		 * address without link-id information.  Then the source
586 		 * address is ::1, and the destination address is the
587 		 * link-local address with its s6_addr16[1] being zero.
588 		 * What is worse, if the packet goes to the loopback interface
589 		 * by a default rejected route, the null pointer would be
590 		 * passed to looutput, and the kernel would hang.
591 		 * The following last resort would prevent such disaster.
592 		 */
593 		if (origifp == NULL)
594 			origifp = ifp;
595 	}
596 	else
597 		origifp = ifp;
598 	/*
599 	 * clear embedded scope identifiers if necessary.
600 	 * in6_clearscope will touch the addresses only when necessary.
601 	 */
602 	in6_clearscope(&ip6->ip6_src);
603 	in6_clearscope(&ip6->ip6_dst);
604 
605 	/*
606 	 * Check with the firewall...
607 	 */
608 	if (ip6_fw_enable && ip6_fw_chk_ptr) {
609 		u_short port = 0;
610 
611 		m->m_pkthdr.rcvif = NULL;	/* XXX */
612 		/* If ipfw says divert, we have to just drop packet */
613 		if ((*ip6_fw_chk_ptr)(&ip6, ifp, &port, &m)) {
614 			m_freem(m);
615 			goto done;
616 		}
617 		if (!m) {
618 			error = EACCES;
619 			goto done;
620 		}
621 	}
622 
623 	/*
624 	 * If the outgoing packet contains a hop-by-hop options header,
625 	 * it must be examined and processed even by the source node.
626 	 * (RFC 2460, section 4.)
627 	 */
628 	if (exthdrs.ip6e_hbh) {
629 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
630 		u_int32_t dummy1; /* XXX unused */
631 		u_int32_t dummy2; /* XXX unused */
632 
633 #ifdef DIAGNOSTIC
634 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
635 			panic("ip6e_hbh is not continuous");
636 #endif
637 		/*
638 		 *  XXX: if we have to send an ICMPv6 error to the sender,
639 		 *       we need the M_LOOP flag since icmp6_error() expects
640 		 *       the IPv6 and the hop-by-hop options header are
641 		 *       continuous unless the flag is set.
642 		 */
643 		m->m_flags |= M_LOOP;
644 		m->m_pkthdr.rcvif = ifp;
645 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
646 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
647 		    &dummy1, &dummy2) < 0) {
648 			/* m was already freed at this point */
649 			error = EINVAL;/* better error? */
650 			goto done;
651 		}
652 		m->m_flags &= ~M_LOOP; /* XXX */
653 		m->m_pkthdr.rcvif = NULL;
654 	}
655 
656 	/*
657 	 * Run through list of hooks for output packets.
658 	 */
659 	if (pfil_has_hooks(&inet6_pfil_hook)) {
660 		error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT);
661 		if (error != 0 || m == NULL)
662 			goto done;
663 		ip6 = mtod(m, struct ip6_hdr *);
664 	}
665 
666 	/*
667 	 * Send the packet to the outgoing interface.
668 	 * If necessary, do IPv6 fragmentation before sending.
669 	 *
670 	 * the logic here is rather complex:
671 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
672 	 * 1-a:	send as is if tlen <= path mtu
673 	 * 1-b:	fragment if tlen > path mtu
674 	 *
675 	 * 2: if user asks us not to fragment (dontfrag == 1)
676 	 * 2-a:	send as is if tlen <= interface mtu
677 	 * 2-b:	error if tlen > interface mtu
678 	 *
679 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
680 	 *	always fragment
681 	 *
682 	 * 4: if dontfrag == 1 && alwaysfrag == 1
683 	 *	error, as we cannot handle this conflicting request
684 	 */
685 	tlen = m->m_pkthdr.len;
686 
687 	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
688 		dontfrag = 1;
689 	else
690 		dontfrag = 0;
691 	if (dontfrag && alwaysfrag) {	/* case 4 */
692 		/* conflicting request - can't transmit */
693 		error = EMSGSIZE;
694 		goto bad;
695 	}
696 	if (dontfrag && tlen > IN6_LINKMTU(ifp)) {	/* case 2-b */
697 		/*
698 		 * Even if the DONTFRAG option is specified, we cannot send the
699 		 * packet when the data length is larger than the MTU of the
700 		 * outgoing interface.
701 		 * Notify the error by sending IPV6_PATHMTU ancillary data as
702 		 * well as returning an error code (the latter is not described
703 		 * in the API spec.)
704 		 */
705 		u_int32_t mtu32;
706 		struct ip6ctlparam ip6cp;
707 
708 		mtu32 = (u_int32_t)mtu;
709 		bzero(&ip6cp, sizeof(ip6cp));
710 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
711 		kpfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
712 		    (void *)&ip6cp);
713 
714 		error = EMSGSIZE;
715 		goto bad;
716 	}
717 
718 	/*
719 	 * transmit packet without fragmentation
720 	 */
721 	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* case 1-a and 2-a */
722 		struct in6_ifaddr *ia6;
723 
724 		ip6 = mtod(m, struct ip6_hdr *);
725 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
726 		if (ia6) {
727 			/* Record statistics for this interface address. */
728 			IFA_STAT_INC(&ia6->ia_ifa, opackets, 1);
729 			IFA_STAT_INC(&ia6->ia_ifa, obytes, m->m_pkthdr.len);
730 		}
731 		error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
732 		goto done;
733 	}
734 
735 	/*
736 	 * try to fragment the packet.  case 1-b and 3
737 	 */
738 	if (mtu < IPV6_MMTU) {
739 		/*
740 		 * note that path MTU is never less than IPV6_MMTU
741 		 * (see icmp6_input).
742 		 */
743 		error = EMSGSIZE;
744 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
745 		goto bad;
746 	} else if (ip6->ip6_plen == 0) {
747 		/* jumbo payload cannot be fragmented */
748 		error = EMSGSIZE;
749 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
750 		goto bad;
751 	} else {
752 		struct mbuf **mnext, *m_frgpart;
753 		struct ip6_frag *ip6f;
754 		u_int32_t id = htonl(ip6_id++);
755 		u_char nextproto;
756 
757 		/*
758 		 * Too large for the destination or interface;
759 		 * fragment if possible.
760 		 * Must be able to put at least 8 bytes per fragment.
761 		 */
762 		hlen = unfragpartlen;
763 		if (mtu > IPV6_MAXPACKET)
764 			mtu = IPV6_MAXPACKET;
765 
766 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
767 		if (len < 8) {
768 			error = EMSGSIZE;
769 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
770 			goto bad;
771 		}
772 
773 		mnext = &m->m_nextpkt;
774 
775 		/*
776 		 * Change the next header field of the last header in the
777 		 * unfragmentable part.
778 		 */
779 		if (exthdrs.ip6e_rthdr) {
780 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
781 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
782 		} else if (exthdrs.ip6e_dest1) {
783 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
784 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
785 		} else if (exthdrs.ip6e_hbh) {
786 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
787 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
788 		} else {
789 			nextproto = ip6->ip6_nxt;
790 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
791 		}
792 
793 		/*
794 		 * Loop through length of segment after first fragment,
795 		 * make new header and copy data of each part and link onto
796 		 * chain.
797 		 */
798 		m0 = m;
799 		for (off = hlen; off < tlen; off += len) {
800 			MGETHDR(m, M_NOWAIT, MT_HEADER);
801 			if (!m) {
802 				error = ENOBUFS;
803 				ip6stat.ip6s_odropped++;
804 				goto sendorfree;
805 			}
806 			m->m_pkthdr.rcvif = NULL;
807 			m->m_flags = m0->m_flags & M_COPYFLAGS;
808 			*mnext = m;
809 			mnext = &m->m_nextpkt;
810 			m->m_data += max_linkhdr;
811 			mhip6 = mtod(m, struct ip6_hdr *);
812 			*mhip6 = *ip6;
813 			m->m_len = sizeof(*mhip6);
814 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
815 			if (error) {
816 				ip6stat.ip6s_odropped++;
817 				goto sendorfree;
818 			}
819 			ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
820 			if (off + len >= tlen)
821 				len = tlen - off;
822 			else
823 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
824 			mhip6->ip6_plen = htons((u_short)(len + hlen +
825 			    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
826 			if ((m_frgpart = m_copy(m0, off, len)) == NULL) {
827 				error = ENOBUFS;
828 				ip6stat.ip6s_odropped++;
829 				goto sendorfree;
830 			}
831 			m_cat(m, m_frgpart);
832 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
833 			m->m_pkthdr.rcvif = NULL;
834 			ip6f->ip6f_reserved = 0;
835 			ip6f->ip6f_ident = id;
836 			ip6f->ip6f_nxt = nextproto;
837 			ip6stat.ip6s_ofragments++;
838 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
839 		}
840 
841 		in6_ifstat_inc(ifp, ifs6_out_fragok);
842 	}
843 
844 	/*
845 	 * Remove leading garbages.
846 	 */
847 sendorfree:
848 	m = m0->m_nextpkt;
849 	m0->m_nextpkt = NULL;
850 	m_freem(m0);
851 	for (m0 = m; m; m = m0) {
852 		m0 = m->m_nextpkt;
853 		m->m_nextpkt = NULL;
854 		if (error == 0) {
855  			/* Record statistics for this interface address. */
856  			if (ia) {
857  				IFA_STAT_INC(&ia->ia_ifa, opackets, 1);
858  				IFA_STAT_INC(&ia->ia_ifa, obytes,
859 				    m->m_pkthdr.len);
860  			}
861 			error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
862 		} else
863 			m_freem(m);
864 	}
865 
866 	if (error == 0)
867 		ip6stat.ip6s_fragmented++;
868 
869 done:
870 	if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
871 		RTFREE(ro->ro_rt);
872 	} else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
873 		RTFREE(ro_pmtu->ro_rt);
874 	}
875 
876 	return (error);
877 
878 freehdrs:
879 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
880 	m_freem(exthdrs.ip6e_dest1);
881 	m_freem(exthdrs.ip6e_rthdr);
882 	m_freem(exthdrs.ip6e_dest2);
883 	/* FALLTHROUGH */
884 bad:
885 	m_freem(m);
886 	goto done;
887 }
888 
889 static int
890 copyexthdr(void *h, struct mbuf **mp)
891 {
892 	struct ip6_ext *hdr = h;
893 	int hlen;
894 	struct mbuf *m;
895 
896 	if (hdr == NULL)
897 		return 0;
898 
899 	hlen = (hdr->ip6e_len + 1) * 8;
900 	if (hlen > MCLBYTES)
901 		return ENOBUFS;	/* XXX */
902 
903 	m = m_getb(hlen, M_NOWAIT, MT_DATA, 0);
904 	if (!m)
905 		return ENOBUFS;
906 	m->m_len = hlen;
907 
908 	bcopy(hdr, mtod(m, caddr_t), hlen);
909 
910 	*mp = m;
911 	return 0;
912 }
913 
914 /*
915  * Insert jumbo payload option.
916  */
917 static int
918 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
919 {
920 	struct mbuf *mopt;
921 	u_char *optbuf;
922 	u_int32_t v;
923 
924 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
925 
926 	/*
927 	 * If there is no hop-by-hop options header, allocate new one.
928 	 * If there is one but it doesn't have enough space to store the
929 	 * jumbo payload option, allocate a cluster to store the whole options.
930 	 * Otherwise, use it to store the options.
931 	 */
932 	if (exthdrs->ip6e_hbh == NULL) {
933 		MGET(mopt, M_NOWAIT, MT_DATA);
934 		if (mopt == NULL)
935 			return (ENOBUFS);
936 		mopt->m_len = JUMBOOPTLEN;
937 		optbuf = mtod(mopt, u_char *);
938 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
939 		exthdrs->ip6e_hbh = mopt;
940 	} else {
941 		struct ip6_hbh *hbh;
942 
943 		mopt = exthdrs->ip6e_hbh;
944 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
945 			/*
946 			 * XXX assumption:
947 			 * - exthdrs->ip6e_hbh is not referenced from places
948 			 *   other than exthdrs.
949 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
950 			 */
951 			int oldoptlen = mopt->m_len;
952 			struct mbuf *n;
953 
954 			/*
955 			 * XXX: give up if the whole (new) hbh header does
956 			 * not fit even in an mbuf cluster.
957 			 */
958 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
959 				return (ENOBUFS);
960 
961 			/*
962 			 * As a consequence, we must always prepare a cluster
963 			 * at this point.
964 			 */
965 			n = m_getcl(M_NOWAIT, MT_DATA, 0);
966 			if (!n)
967 				return (ENOBUFS);
968 			n->m_len = oldoptlen + JUMBOOPTLEN;
969 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t), oldoptlen);
970 			optbuf = mtod(n, caddr_t) + oldoptlen;
971 			m_freem(mopt);
972 			mopt = exthdrs->ip6e_hbh = n;
973 		} else {
974 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
975 			mopt->m_len += JUMBOOPTLEN;
976 		}
977 		optbuf[0] = IP6OPT_PADN;
978 		optbuf[1] = 1;
979 
980 		/*
981 		 * Adjust the header length according to the pad and
982 		 * the jumbo payload option.
983 		 */
984 		hbh = mtod(mopt, struct ip6_hbh *);
985 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
986 	}
987 
988 	/* fill in the option. */
989 	optbuf[2] = IP6OPT_JUMBO;
990 	optbuf[3] = 4;
991 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
992 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
993 
994 	/* finally, adjust the packet header length */
995 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
996 
997 	return (0);
998 #undef JUMBOOPTLEN
999 }
1000 
1001 /*
1002  * Insert fragment header and copy unfragmentable header portions.
1003  */
1004 static int
1005 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1006 		  struct ip6_frag **frghdrp)
1007 {
1008 	struct mbuf *n, *mlast;
1009 
1010 	if (hlen > sizeof(struct ip6_hdr)) {
1011 		n = m_copym(m0, sizeof(struct ip6_hdr),
1012 			    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1013 		if (n == NULL)
1014 			return (ENOBUFS);
1015 		m->m_next = n;
1016 	} else
1017 		n = m;
1018 
1019 	/* Search for the last mbuf of unfragmentable part. */
1020 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1021 		;
1022 
1023 	if (!(mlast->m_flags & M_EXT) &&
1024 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1025 		/* use the trailing space of the last mbuf for the fragment hdr */
1026 		*frghdrp = (struct ip6_frag *)
1027 		    (mtod(mlast, caddr_t) + mlast->m_len);
1028 		mlast->m_len += sizeof(struct ip6_frag);
1029 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1030 	} else {
1031 		/* allocate a new mbuf for the fragment header */
1032 		struct mbuf *mfrg;
1033 
1034 		MGET(mfrg, M_NOWAIT, MT_DATA);
1035 		if (mfrg == NULL)
1036 			return (ENOBUFS);
1037 		mfrg->m_len = sizeof(struct ip6_frag);
1038 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1039 		mlast->m_next = mfrg;
1040 	}
1041 
1042 	return (0);
1043 }
1044 
1045 static int
1046 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1047     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1048     int *alwaysfragp)
1049 {
1050 	u_int32_t mtu = 0;
1051 	int alwaysfrag = 0;
1052 	int error = 0;
1053 
1054 	if (ro_pmtu != ro) {
1055 		/* The first hop and the final destination may differ. */
1056 		struct sockaddr_in6 *sa6_dst =
1057 		    (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1058 		if (ro_pmtu->ro_rt &&
1059 		    ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1060 		     !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1061 			RTFREE(ro_pmtu->ro_rt);
1062 			ro_pmtu->ro_rt = NULL;
1063 		}
1064 		if (ro_pmtu->ro_rt == NULL) {
1065 			bzero(sa6_dst, sizeof(*sa6_dst));
1066 			sa6_dst->sin6_family = AF_INET6;
1067 			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1068 			sa6_dst->sin6_addr = *dst;
1069 
1070 			rtalloc((struct route *)ro_pmtu);
1071 		}
1072 	}
1073 	if (ro_pmtu->ro_rt) {
1074 		u_int32_t ifmtu;
1075 
1076 		if (ifp == NULL)
1077 			ifp = ro_pmtu->ro_rt->rt_ifp;
1078 		ifmtu = IN6_LINKMTU(ifp);
1079 		mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1080 		if (mtu == 0) {
1081 			mtu = ifmtu;
1082 		} else if (mtu < IPV6_MMTU) {
1083 			/*
1084 			 * RFC2460 section 5, last paragraph:
1085 			 * if we record ICMPv6 too big message with
1086 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1087 			 * or smaller, with framgent header attached.
1088 			 * (fragment header is needed regardless from the
1089 			 * packet size, for translators to identify packets)
1090 			 */
1091 			alwaysfrag = 1;
1092 			mtu = IPV6_MMTU;
1093 		} else if (mtu > ifmtu) {
1094 			/*
1095 			 * The MTU on the route is larger than the MTU on
1096 			 * the interface!  This shouldn't happen, unless the
1097 			 * MTU of the interface has been changed after the
1098 			 * interface was brought up.  Change the MTU in the
1099 			 * route to match the interface MTU (as long as the
1100 			 * field isn't locked).
1101 			 */
1102 			mtu = ifmtu;
1103 			ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1104 		}
1105 	} else if (ifp) {
1106 		mtu = IN6_LINKMTU(ifp);
1107 	} else {
1108 		error = EHOSTUNREACH; /* XXX */
1109 	}
1110 
1111 	*mtup = mtu;
1112 	if (alwaysfragp)
1113 		*alwaysfragp = alwaysfrag;
1114 	return (error);
1115 }
1116 
1117 /*
1118  * IP6 socket option processing.
1119  */
1120 void
1121 ip6_ctloutput_dispatch(netmsg_t msg)
1122 {
1123 	int error;
1124 
1125 	error = ip6_ctloutput(msg->ctloutput.base.nm_so,
1126 			      msg->ctloutput.nm_sopt);
1127 	lwkt_replymsg(&msg->ctloutput.base.lmsg, error);
1128 }
1129 
1130 int
1131 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1132 {
1133 	int optdatalen,uproto;
1134 	int privileged;
1135 	struct inpcb *in6p = so->so_pcb;
1136 	void *optdata;
1137 	int error, optval;
1138 	int level, op, optname;
1139 	int optlen;
1140 	struct thread *td;
1141 
1142 	if (sopt) {
1143 		level = sopt->sopt_level;
1144 		op = sopt->sopt_dir;
1145 		optname = sopt->sopt_name;
1146 		optlen = sopt->sopt_valsize;
1147 		td = sopt->sopt_td;
1148 	} else {
1149 		panic("ip6_ctloutput: arg soopt is NULL");
1150 		/* NOT REACHED */
1151 		td = NULL;
1152 	}
1153 	error = optval = 0;
1154 
1155 	uproto = (int)so->so_proto->pr_protocol;
1156 	privileged = (td == NULL || priv_check(td, PRIV_ROOT)) ? 0 : 1;
1157 
1158 	if (level == IPPROTO_IPV6) {
1159 		switch (op) {
1160 
1161 		case SOPT_SET:
1162 			switch (optname) {
1163 			case IPV6_2292PKTOPTIONS:
1164 #ifdef IPV6_PKTOPTIONS
1165 			case IPV6_PKTOPTIONS:
1166 #endif
1167 			{
1168 				struct mbuf *m;
1169 
1170 				error = soopt_getm(sopt, &m); /* XXX */
1171 				if (error != 0)
1172 					break;
1173 				soopt_to_mbuf(sopt, m); /* XXX */
1174 				error = ip6_pcbopts(&in6p->in6p_outputopts,
1175 						    m, so, sopt);
1176 				m_freem(m); /* XXX */
1177 				break;
1178 			}
1179 
1180 			/*
1181 			 * Use of some Hop-by-Hop options or some
1182 			 * Destination options, might require special
1183 			 * privilege.  That is, normal applications
1184 			 * (without special privilege) might be forbidden
1185 			 * from setting certain options in outgoing packets,
1186 			 * and might never see certain options in received
1187 			 * packets. [RFC 2292 Section 6]
1188 			 * KAME specific note:
1189 			 *  KAME prevents non-privileged users from sending or
1190 			 *  receiving ANY hbh/dst options in order to avoid
1191 			 *  overhead of parsing options in the kernel.
1192 			 */
1193 			case IPV6_RECVHOPOPTS:
1194 			case IPV6_RECVDSTOPTS:
1195 			case IPV6_RECVRTHDRDSTOPTS:
1196 				if (!privileged)
1197 					return (EPERM);
1198 			case IPV6_RECVPKTINFO:
1199 			case IPV6_RECVHOPLIMIT:
1200 			case IPV6_RECVRTHDR:
1201 			case IPV6_RECVPATHMTU:
1202 			case IPV6_RECVTCLASS:
1203 			case IPV6_AUTOFLOWLABEL:
1204 			case IPV6_HOPLIMIT:
1205 			/* FALLTHROUGH */
1206 			case IPV6_UNICAST_HOPS:
1207 
1208 			case IPV6_V6ONLY:
1209 				if (optlen != sizeof(int)) {
1210 					error = EINVAL;
1211 					break;
1212 				}
1213 				error = soopt_to_kbuf(sopt, &optval,
1214 					sizeof optval, sizeof optval);
1215 				if (error)
1216 					break;
1217 				switch (optname) {
1218 
1219 				case IPV6_UNICAST_HOPS:
1220 					if (optval < -1 || optval >= 256)
1221 						error = EINVAL;
1222 					else {
1223 						/* -1 = kernel default */
1224 						in6p->in6p_hops = optval;
1225 					}
1226 					break;
1227 #define OPTSET(bit) \
1228 do { \
1229 	if (optval) \
1230 		in6p->in6p_flags |= (bit); \
1231 	else \
1232 		in6p->in6p_flags &= ~(bit); \
1233 } while (0)
1234 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
1235 /*
1236  * Although changed to RFC3542, It's better to also support RFC2292 API
1237  */
1238 #define OPTSET2292(bit) \
1239 do { \
1240 	in6p->in6p_flags |= IN6P_RFC2292; \
1241 	if (optval) \
1242 		in6p->in6p_flags |= (bit); \
1243 	else \
1244 		in6p->in6p_flags &= ~(bit); \
1245 } while (/*CONSTCOND*/ 0)
1246 
1247 				case IPV6_RECVPKTINFO:
1248 					/* cannot mix with RFC2292 */
1249 					if (OPTBIT(IN6P_RFC2292)) {
1250 						error = EINVAL;
1251 						break;
1252 					}
1253 					OPTSET(IN6P_PKTINFO);
1254 					break;
1255 
1256 				case IPV6_HOPLIMIT:
1257 				{
1258 					struct ip6_pktopts **optp;
1259 
1260 					/* cannot mix with RFC2292 */
1261 					if (OPTBIT(IN6P_RFC2292)) {
1262 						error = EINVAL;
1263 						break;
1264 					}
1265 					optp = &in6p->in6p_outputopts;
1266 					error = ip6_pcbopt(IPV6_HOPLIMIT,
1267 					    (u_char *)&optval, sizeof(optval),
1268 					    optp, uproto);
1269 					break;
1270 				}
1271 
1272 				case IPV6_RECVHOPLIMIT:
1273 					/* cannot mix with RFC2292 */
1274 					if (OPTBIT(IN6P_RFC2292)) {
1275 						error = EINVAL;
1276 						break;
1277 					}
1278 					OPTSET(IN6P_HOPLIMIT);
1279 					break;
1280 
1281 				case IPV6_RECVHOPOPTS:
1282 					/* cannot mix with RFC2292 */
1283 					if (OPTBIT(IN6P_RFC2292)) {
1284 						error = EINVAL;
1285 						break;
1286 					}
1287 					OPTSET(IN6P_HOPOPTS);
1288 					break;
1289 
1290 				case IPV6_RECVDSTOPTS:
1291 					/* cannot mix with RFC2292 */
1292 					if (OPTBIT(IN6P_RFC2292)) {
1293 						error = EINVAL;
1294 						break;
1295 					}
1296 					OPTSET(IN6P_DSTOPTS);
1297 					break;
1298 
1299 				case IPV6_RECVRTHDRDSTOPTS:
1300 					/* cannot mix with RFC2292 */
1301 					if (OPTBIT(IN6P_RFC2292)) {
1302 						error = EINVAL;
1303 						break;
1304 					}
1305 					OPTSET(IN6P_RTHDRDSTOPTS);
1306 					break;
1307 
1308 				case IPV6_RECVRTHDR:
1309 					/* cannot mix with RFC2292 */
1310 					if (OPTBIT(IN6P_RFC2292)) {
1311 						error = EINVAL;
1312 						break;
1313 					}
1314 					OPTSET(IN6P_RTHDR);
1315 					break;
1316 
1317 				case IPV6_RECVPATHMTU:
1318 					/*
1319 					 * We ignore this option for TCP
1320 					 * sockets.
1321 					 * (RFC3542 leaves this case
1322 					 * unspecified.)
1323 					 */
1324 					if (uproto != IPPROTO_TCP)
1325 						OPTSET(IN6P_MTU);
1326 					break;
1327 
1328 				case IPV6_RECVTCLASS:
1329 					/* cannot mix with RFC2292 XXX */
1330 					if (OPTBIT(IN6P_RFC2292)) {
1331 						error = EINVAL;
1332 						break;
1333 					}
1334 					OPTSET(IN6P_TCLASS);
1335 					break;
1336 
1337 				case IPV6_AUTOFLOWLABEL:
1338 					OPTSET(IN6P_AUTOFLOWLABEL);
1339 					break;
1340 
1341 				case IPV6_V6ONLY:
1342 					/*
1343 					 * make setsockopt(IPV6_V6ONLY)
1344 					 * available only prior to bind(2).
1345 					 */
1346 					if (in6p->in6p_lport ||
1347 					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr))
1348 					{
1349 						error = EINVAL;
1350 						break;
1351 					}
1352 					if (!optval) {
1353 						/* Don't allow v4-mapped */
1354 						error = EOPNOTSUPP;
1355 					}
1356 					break;
1357 				}
1358 				break;
1359 
1360 			case IPV6_TCLASS:
1361 			case IPV6_DONTFRAG:
1362 			case IPV6_USE_MIN_MTU:
1363 			case IPV6_PREFER_TEMPADDR:
1364 				if (optlen != sizeof(optval)) {
1365 					error = EINVAL;
1366 					break;
1367 				}
1368 				error = soopt_to_kbuf(sopt, &optval,
1369 					sizeof optval, sizeof optval);
1370 				if (error)
1371 					break;
1372 				{
1373 					struct ip6_pktopts **optp;
1374 					optp = &in6p->in6p_outputopts;
1375 					error = ip6_pcbopt(optname,
1376 					    (u_char *)&optval, sizeof(optval),
1377 					    optp, uproto);
1378 					break;
1379 				}
1380 
1381 			case IPV6_2292PKTINFO:
1382 			case IPV6_2292HOPLIMIT:
1383 			case IPV6_2292HOPOPTS:
1384 			case IPV6_2292DSTOPTS:
1385 			case IPV6_2292RTHDR:
1386 				/* RFC 2292 */
1387 				if (optlen != sizeof(int)) {
1388 					error = EINVAL;
1389 					break;
1390 				}
1391 				error = soopt_to_kbuf(sopt, &optval,
1392 					sizeof optval, sizeof optval);
1393 				if (error)
1394 					break;
1395 				switch (optname) {
1396 				case IPV6_2292PKTINFO:
1397 					OPTSET2292(IN6P_PKTINFO);
1398 					break;
1399 				case IPV6_2292HOPLIMIT:
1400 					OPTSET2292(IN6P_HOPLIMIT);
1401 					break;
1402 				case IPV6_2292HOPOPTS:
1403 					/*
1404 					 * Check super-user privilege.
1405 					 * See comments for IPV6_RECVHOPOPTS.
1406 					 */
1407 					if (!privileged)
1408 						return (EPERM);
1409 					OPTSET2292(IN6P_HOPOPTS);
1410 					break;
1411 				case IPV6_2292DSTOPTS:
1412 					if (!privileged)
1413 						return (EPERM);
1414 					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1415 					break;
1416 				case IPV6_2292RTHDR:
1417 					OPTSET2292(IN6P_RTHDR);
1418 					break;
1419 				}
1420 				break;
1421 
1422 			case IPV6_PKTINFO:
1423 			case IPV6_HOPOPTS:
1424 			case IPV6_RTHDR:
1425 			case IPV6_DSTOPTS:
1426 			case IPV6_RTHDRDSTOPTS:
1427 			case IPV6_NEXTHOP:
1428 			{
1429 				/*
1430 				 * New advanced API (RFC3542)
1431 				 */
1432 				u_char *optbuf;
1433 				u_char optbuf_storage[MCLBYTES];
1434 				int optlen;
1435 				struct ip6_pktopts **optp;
1436 
1437 				/* cannot mix with RFC2292 */
1438 				if (OPTBIT(IN6P_RFC2292)) {
1439 					error = EINVAL;
1440 					break;
1441 				}
1442 
1443 				/*
1444 				 * We only ensure valsize is not too large
1445 				 * here.  Further validation will be done
1446 				 * later.
1447 				 */
1448 				error = soopt_to_kbuf(sopt, optbuf_storage,
1449 				    sizeof(optbuf_storage), 0);
1450 				if (error)
1451 					break;
1452 				optlen = sopt->sopt_valsize;
1453 				optbuf = optbuf_storage;
1454 				optp = &in6p->in6p_outputopts;
1455 				error = ip6_pcbopt(optname, optbuf, optlen,
1456 				    optp, uproto);
1457 				break;
1458 			}
1459 #undef OPTSET
1460 
1461 			case IPV6_MULTICAST_IF:
1462 			case IPV6_MULTICAST_HOPS:
1463 			case IPV6_MULTICAST_LOOP:
1464 			case IPV6_JOIN_GROUP:
1465 			case IPV6_LEAVE_GROUP:
1466 			    {
1467 				struct mbuf *m;
1468 
1469 				if (sopt->sopt_valsize > MLEN) {
1470 					error = EMSGSIZE;
1471 					break;
1472 				}
1473 				/* XXX */
1474 				MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_HEADER);
1475 				if (m == NULL) {
1476 					error = ENOBUFS;
1477 					break;
1478 				}
1479 				m->m_len = sopt->sopt_valsize;
1480 				error = soopt_to_kbuf(sopt, mtod(m, char *),
1481 						    m->m_len, m->m_len);
1482 				error =	ip6_setmoptions(sopt->sopt_name,
1483 							&in6p->in6p_moptions,
1484 							m);
1485 				m_free(m);
1486 			    }
1487 				break;
1488 
1489 			case IPV6_PORTRANGE:
1490 				error = soopt_to_kbuf(sopt, &optval,
1491 				    sizeof optval, sizeof optval);
1492 				if (error)
1493 					break;
1494 
1495 				switch (optval) {
1496 				case IPV6_PORTRANGE_DEFAULT:
1497 					in6p->in6p_flags &= ~(IN6P_LOWPORT);
1498 					in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1499 					break;
1500 
1501 				case IPV6_PORTRANGE_HIGH:
1502 					in6p->in6p_flags &= ~(IN6P_LOWPORT);
1503 					in6p->in6p_flags |= IN6P_HIGHPORT;
1504 					break;
1505 
1506 				case IPV6_PORTRANGE_LOW:
1507 					in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1508 					in6p->in6p_flags |= IN6P_LOWPORT;
1509 					break;
1510 
1511 				default:
1512 					error = EINVAL;
1513 					break;
1514 				}
1515 				break;
1516 
1517 			case IPV6_FW_ADD:
1518 			case IPV6_FW_DEL:
1519 			case IPV6_FW_FLUSH:
1520 			case IPV6_FW_ZERO:
1521 			    {
1522 				struct mbuf *m;
1523 				struct mbuf **mp = &m;
1524 
1525 				if (ip6_fw_ctl_ptr == NULL)
1526 					return EINVAL;
1527 				/* XXX */
1528 				if ((error = soopt_getm(sopt, &m)) != 0)
1529 					break;
1530 				/* XXX */
1531 				soopt_to_mbuf(sopt, m);
1532 				error = (*ip6_fw_ctl_ptr)(optname, mp);
1533 				m = *mp;
1534 			    }
1535 				break;
1536 
1537 			default:
1538 				error = ENOPROTOOPT;
1539 				break;
1540 			}
1541 			break;
1542 
1543 		case SOPT_GET:
1544 			switch (optname) {
1545 			case IPV6_2292PKTOPTIONS:
1546 #ifdef IPV6_PKTOPTIONS
1547 			case IPV6_PKTOPTIONS:
1548 #endif
1549 				/*
1550 				 * RFC3542 (effectively) deprecated the
1551 				 * semantics of the 2292-style pktoptions.
1552 				 * Since it was not reliable in nature (i.e.,
1553 				 * applications had to expect the lack of some
1554 				 * information after all), it would make sense
1555 				 * to simplify this part by always returning
1556 				 * empty data.
1557 				 */
1558 				if (in6p->in6p_options) {
1559 					struct mbuf *m;
1560 					m = m_copym(in6p->in6p_options,
1561 					    0, M_COPYALL, M_WAITOK);
1562 					error = soopt_from_mbuf(sopt, m);
1563 					if (error == 0)
1564 						m_freem(m);
1565 				} else
1566 					sopt->sopt_valsize = 0;
1567 				break;
1568 
1569 			case IPV6_RECVHOPOPTS:
1570 			case IPV6_RECVDSTOPTS:
1571 			case IPV6_RECVRTHDRDSTOPTS:
1572 			case IPV6_UNICAST_HOPS:
1573 			case IPV6_RECVPKTINFO:
1574 			case IPV6_RECVHOPLIMIT:
1575 			case IPV6_RECVRTHDR:
1576 			case IPV6_RECVPATHMTU:
1577 			case IPV6_RECVTCLASS:
1578 			case IPV6_AUTOFLOWLABEL:
1579 			case IPV6_V6ONLY:
1580 			case IPV6_PORTRANGE:
1581 				switch (optname) {
1582 
1583 				case IPV6_RECVHOPOPTS:
1584 					optval = OPTBIT(IN6P_HOPOPTS);
1585 					break;
1586 
1587 				case IPV6_RECVDSTOPTS:
1588 					optval = OPTBIT(IN6P_DSTOPTS);
1589 					break;
1590 
1591 				case IPV6_RECVRTHDRDSTOPTS:
1592 					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1593 					break;
1594 
1595 				case IPV6_RECVPKTINFO:
1596 					optval = OPTBIT(IN6P_PKTINFO);
1597 					break;
1598 
1599 				case IPV6_RECVHOPLIMIT:
1600 					optval = OPTBIT(IN6P_HOPLIMIT);
1601 					break;
1602 
1603 				case IPV6_RECVRTHDR:
1604 					optval = OPTBIT(IN6P_RTHDR);
1605 					break;
1606 
1607 				case IPV6_RECVPATHMTU:
1608 					optval = OPTBIT(IN6P_MTU);
1609 					break;
1610 
1611 				case IPV6_RECVTCLASS:
1612 					optval = OPTBIT(IN6P_TCLASS);
1613 					break;
1614 
1615 				case IPV6_AUTOFLOWLABEL:
1616 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1617 					break;
1618 
1619 
1620 				case IPV6_UNICAST_HOPS:
1621 					optval = in6p->in6p_hops;
1622 					break;
1623 
1624 				case IPV6_V6ONLY:
1625 					optval = 1;
1626 					break;
1627 
1628 				case IPV6_PORTRANGE:
1629 				    {
1630 					int flags;
1631 					flags = in6p->in6p_flags;
1632 					if (flags & IN6P_HIGHPORT)
1633 						optval = IPV6_PORTRANGE_HIGH;
1634 					else if (flags & IN6P_LOWPORT)
1635 						optval = IPV6_PORTRANGE_LOW;
1636 					else
1637 						optval = 0;
1638 					break;
1639 				    }
1640 				}
1641 				soopt_from_kbuf(sopt, &optval,
1642  					sizeof optval);
1643 				break;
1644 
1645 			case IPV6_PATHMTU:
1646 			{
1647 				u_long pmtu = 0;
1648 				struct ip6_mtuinfo mtuinfo;
1649 				struct route_in6 sro;
1650 
1651 				bzero(&sro, sizeof(sro));
1652 
1653 				if (!(so->so_state & SS_ISCONNECTED))
1654 					return (ENOTCONN);
1655 				/*
1656 				 * XXX: we dot not consider the case of source
1657 				 * routing, or optional information to specify
1658 				 * the outgoing interface.
1659 				 */
1660 				error = ip6_getpmtu(&sro, NULL, NULL,
1661 				    &in6p->in6p_faddr, &pmtu, NULL);
1662 				if (sro.ro_rt)
1663 					RTFREE(sro.ro_rt);
1664 				if (error)
1665 					break;
1666 				if (pmtu > IPV6_MAXPACKET)
1667 					pmtu = IPV6_MAXPACKET;
1668 
1669 				bzero(&mtuinfo, sizeof(mtuinfo));
1670 				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1671 				optdata = (void *)&mtuinfo;
1672 				optdatalen = sizeof(mtuinfo);
1673 				soopt_from_kbuf(sopt, optdata,
1674 				    optdatalen);
1675 				break;
1676 			}
1677 
1678 			case IPV6_2292PKTINFO:
1679 			case IPV6_2292HOPLIMIT:
1680 			case IPV6_2292HOPOPTS:
1681 			case IPV6_2292RTHDR:
1682 			case IPV6_2292DSTOPTS:
1683 				if (optname == IPV6_2292HOPOPTS ||
1684 				    optname == IPV6_2292DSTOPTS ||
1685 				    !privileged)
1686 					return (EPERM);
1687 				switch (optname) {
1688 				case IPV6_2292PKTINFO:
1689 					optval = OPTBIT(IN6P_PKTINFO);
1690 					break;
1691 				case IPV6_2292HOPLIMIT:
1692 					optval = OPTBIT(IN6P_HOPLIMIT);
1693 					break;
1694 				case IPV6_2292HOPOPTS:
1695 					if (!privileged)
1696 						return (EPERM);
1697 					optval = OPTBIT(IN6P_HOPOPTS);
1698 					break;
1699 				case IPV6_2292RTHDR:
1700 					optval = OPTBIT(IN6P_RTHDR);
1701 					break;
1702 				case IPV6_2292DSTOPTS:
1703 					if (!privileged)
1704 						return (EPERM);
1705 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1706 					break;
1707 				}
1708 				soopt_from_kbuf(sopt, &optval,
1709  					sizeof optval);
1710 				break;
1711 
1712 			case IPV6_PKTINFO:
1713 			case IPV6_HOPOPTS:
1714 			case IPV6_RTHDR:
1715 			case IPV6_DSTOPTS:
1716 			case IPV6_RTHDRDSTOPTS:
1717 			case IPV6_NEXTHOP:
1718 			case IPV6_TCLASS:
1719 			case IPV6_DONTFRAG:
1720 			case IPV6_USE_MIN_MTU:
1721 			case IPV6_PREFER_TEMPADDR:
1722 				error = ip6_getpcbopt(in6p->in6p_outputopts,
1723 				    optname, sopt);
1724 				break;
1725 
1726 			case IPV6_MULTICAST_IF:
1727 			case IPV6_MULTICAST_HOPS:
1728 			case IPV6_MULTICAST_LOOP:
1729 			case IPV6_JOIN_GROUP:
1730 			case IPV6_LEAVE_GROUP:
1731 			    {
1732 				struct mbuf *m;
1733 				error = ip6_getmoptions(sopt->sopt_name,
1734 				    in6p->in6p_moptions, &m);
1735 				if (error == 0) {
1736 					soopt_from_kbuf(sopt,
1737  					    mtod(m, char *), m->m_len);
1738 				}
1739 				m_freem(m);
1740 			    }
1741 				break;
1742 
1743 			case IPV6_FW_GET:
1744 			  {
1745 				struct mbuf *m;
1746 				struct mbuf **mp = &m;
1747 
1748 				if (ip6_fw_ctl_ptr == NULL)
1749 				{
1750 					return EINVAL;
1751 				}
1752 				error = (*ip6_fw_ctl_ptr)(optname, mp);
1753 				if (error == 0)
1754 					error = soopt_from_mbuf(sopt, m); /* XXX */
1755 				if (error == 0 && m != NULL)
1756 					m_freem(m);
1757 			  }
1758 				break;
1759 
1760 			default:
1761 				error = ENOPROTOOPT;
1762 				break;
1763 			}
1764 			break;
1765 		}
1766 	} else {
1767 		error = EINVAL;
1768 	}
1769 	return (error);
1770 }
1771 
1772 int
1773 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
1774 {
1775 	int error = 0, optval, optlen;
1776 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
1777 	struct in6pcb *in6p = sotoin6pcb(so);
1778 	int level, op, optname;
1779 
1780 	if (sopt) {
1781 		level = sopt->sopt_level;
1782 		op = sopt->sopt_dir;
1783 		optname = sopt->sopt_name;
1784 		optlen = sopt->sopt_valsize;
1785 	} else
1786 		panic("ip6_raw_ctloutput: arg soopt is NULL");
1787 
1788 	if (level != IPPROTO_IPV6) {
1789 		return (EINVAL);
1790 	}
1791 
1792 	switch (optname) {
1793 	case IPV6_CHECKSUM:
1794 		/*
1795 		 * For ICMPv6 sockets, no modification allowed for checksum
1796 		 * offset, permit "no change" values to help existing apps.
1797 		 *
1798 		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
1799 		 * for an ICMPv6 socket will fail."
1800 		 * The current behavior does not meet RFC3542.
1801 		 */
1802 		switch (op) {
1803 		case SOPT_SET:
1804 			if (optlen != sizeof(int)) {
1805 				error = EINVAL;
1806 				break;
1807 			}
1808 			error = soopt_to_kbuf(sopt, &optval,
1809 				    sizeof optval, sizeof optval);
1810 			if (error)
1811 				break;
1812 			if ((optval % 2) != 0) {
1813 				/* the API assumes even offset values */
1814 				error = EINVAL;
1815 			} else if (so->so_proto->pr_protocol ==
1816 			    IPPROTO_ICMPV6) {
1817 				if (optval != icmp6off)
1818 					error = EINVAL;
1819 			} else
1820 				in6p->in6p_cksum = optval;
1821 			break;
1822 
1823 		case SOPT_GET:
1824 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
1825 				optval = icmp6off;
1826 			else
1827 				optval = in6p->in6p_cksum;
1828 
1829 			soopt_from_kbuf(sopt, &optval, sizeof(optval));
1830 			break;
1831 
1832 		default:
1833 			error = EINVAL;
1834 			break;
1835 		}
1836 		break;
1837 
1838 	default:
1839 		error = ENOPROTOOPT;
1840 		break;
1841 	}
1842 
1843 	return (error);
1844 }
1845 
1846 /*
1847  * Set up IP6 options in pcb for insertion in output packets or
1848  * specifying behavior of outgoing packets.
1849  */
1850 static int
1851 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
1852     struct socket *so, struct sockopt *sopt)
1853 {
1854 	int priv = 0;
1855 	struct ip6_pktopts *opt = *pktopt;
1856 	int error = 0;
1857 
1858 	/* turn off any old options. */
1859 	if (opt) {
1860 #ifdef DIAGNOSTIC
1861 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
1862 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
1863 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
1864 			kprintf("ip6_pcbopts: all specified options are cleared.\n");
1865 #endif
1866 		ip6_clearpktopts(opt, -1);
1867 	} else
1868 		opt = kmalloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
1869 	*pktopt = NULL;
1870 
1871 	if (!m || m->m_len == 0) {
1872 		/*
1873 		 * Only turning off any previous options, regardless of
1874 		 * whether the opt is just created or given.
1875 		 */
1876 		kfree(opt, M_IP6OPT);
1877 		return (0);
1878 	}
1879 
1880 	/*  set options specified by user. */
1881 	if ((error = ip6_setpktoptions(m, opt, NULL, so->so_proto->pr_protocol, priv)) != 0) {
1882 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
1883 		kfree(opt, M_IP6OPT);
1884 		return (error);
1885 	}
1886 	*pktopt = opt;
1887 	return (0);
1888 }
1889 
1890 
1891 /*
1892  * Below three functions are introduced by merge to RFC3542
1893  */
1894 
1895 static int
1896 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
1897 {
1898 	void *optdata = NULL;
1899 	int optdatalen = 0;
1900 	struct ip6_ext *ip6e;
1901 	int error = 0;
1902 	struct in6_pktinfo null_pktinfo;
1903 	int deftclass = 0, on;
1904 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
1905 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
1906 
1907 	switch (optname) {
1908 	case IPV6_PKTINFO:
1909 		if (pktopt && pktopt->ip6po_pktinfo)
1910 			optdata = (void *)pktopt->ip6po_pktinfo;
1911 		else {
1912 			/* XXX: we don't have to do this every time... */
1913 			bzero(&null_pktinfo, sizeof(null_pktinfo));
1914 			optdata = (void *)&null_pktinfo;
1915 		}
1916 		optdatalen = sizeof(struct in6_pktinfo);
1917 		break;
1918 	case IPV6_TCLASS:
1919 		if (pktopt && pktopt->ip6po_tclass >= 0)
1920 			optdata = (void *)&pktopt->ip6po_tclass;
1921 		else
1922 			optdata = (void *)&deftclass;
1923 		optdatalen = sizeof(int);
1924 		break;
1925 	case IPV6_HOPOPTS:
1926 		if (pktopt && pktopt->ip6po_hbh) {
1927 			optdata = (void *)pktopt->ip6po_hbh;
1928 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
1929 			optdatalen = (ip6e->ip6e_len + 1) << 3;
1930 		}
1931 		break;
1932 	case IPV6_RTHDR:
1933 		if (pktopt && pktopt->ip6po_rthdr) {
1934 			optdata = (void *)pktopt->ip6po_rthdr;
1935 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
1936 			optdatalen = (ip6e->ip6e_len + 1) << 3;
1937 		}
1938 		break;
1939 	case IPV6_RTHDRDSTOPTS:
1940 		if (pktopt && pktopt->ip6po_dest1) {
1941 			optdata = (void *)pktopt->ip6po_dest1;
1942 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
1943 			optdatalen = (ip6e->ip6e_len + 1) << 3;
1944 		}
1945 		break;
1946 	case IPV6_DSTOPTS:
1947 		if (pktopt && pktopt->ip6po_dest2) {
1948 			optdata = (void *)pktopt->ip6po_dest2;
1949 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
1950 			optdatalen = (ip6e->ip6e_len + 1) << 3;
1951 		}
1952 		break;
1953 	case IPV6_NEXTHOP:
1954 		if (pktopt && pktopt->ip6po_nexthop) {
1955 			optdata = (void *)pktopt->ip6po_nexthop;
1956 			optdatalen = pktopt->ip6po_nexthop->sa_len;
1957 		}
1958 		break;
1959 	case IPV6_USE_MIN_MTU:
1960 		if (pktopt)
1961 			optdata = (void *)&pktopt->ip6po_minmtu;
1962 		else
1963 			optdata = (void *)&defminmtu;
1964 		optdatalen = sizeof(int);
1965 		break;
1966 	case IPV6_DONTFRAG:
1967 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
1968 			on = 1;
1969 		else
1970 			on = 0;
1971 		optdata = (void *)&on;
1972 		optdatalen = sizeof(on);
1973 		break;
1974 	case IPV6_PREFER_TEMPADDR:
1975 		if (pktopt)
1976 			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
1977 		else
1978 			optdata = (void *)&defpreftemp;
1979 		optdatalen = sizeof(int);
1980 		break;
1981 	default:		/* should not happen */
1982 #ifdef DIAGNOSTIC
1983 		panic("ip6_getpcbopt: unexpected option");
1984 #endif
1985 		return (ENOPROTOOPT);
1986 	}
1987 
1988 	soopt_from_kbuf(sopt, optdata, optdatalen);
1989 
1990 	return (error);
1991 }
1992 
1993 /*
1994  * initialize ip6_pktopts.  beware that there are non-zero default values in
1995  * the struct.
1996  */
1997 
1998 static int
1999 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt, int uproto)
2000 {
2001 	struct ip6_pktopts *opt;
2002 	int priv =0;
2003 	if (*pktopt == NULL) {
2004 		*pktopt = kmalloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2005 		init_ip6pktopts(*pktopt);
2006 	}
2007 	opt = *pktopt;
2008 
2009 	return (ip6_setpktoption(optname, buf, len, opt, 1, 0, uproto, priv));
2010 }
2011 
2012 /*
2013  * initialize ip6_pktopts.  beware that there are non-zero default values in
2014  * the struct.
2015  */
2016 void
2017 init_ip6pktopts(struct ip6_pktopts *opt)
2018 {
2019 
2020 	bzero(opt, sizeof(*opt));
2021 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2022 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2023 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2024 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2025 }
2026 
2027 void
2028 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2029 {
2030 	if (pktopt == NULL)
2031 		return;
2032 
2033 	if (optname == -1 || optname == IPV6_PKTINFO) {
2034 		if (pktopt->ip6po_pktinfo)
2035 			kfree(pktopt->ip6po_pktinfo, M_IP6OPT);
2036 		pktopt->ip6po_pktinfo = NULL;
2037 	}
2038 	if (optname == -1 || optname == IPV6_HOPLIMIT)
2039 		pktopt->ip6po_hlim = -1;
2040 	if (optname == -1 || optname == IPV6_TCLASS)
2041 		pktopt->ip6po_tclass = -1;
2042 	if (optname == -1 || optname == IPV6_NEXTHOP) {
2043 		if (pktopt->ip6po_nextroute.ro_rt) {
2044 			RTFREE(pktopt->ip6po_nextroute.ro_rt);
2045 			pktopt->ip6po_nextroute.ro_rt = NULL;
2046 		}
2047 		if (pktopt->ip6po_nexthop)
2048 			kfree(pktopt->ip6po_nexthop, M_IP6OPT);
2049 		pktopt->ip6po_nexthop = NULL;
2050 	}
2051 	if (optname == -1 || optname == IPV6_HOPOPTS) {
2052 		if (pktopt->ip6po_hbh)
2053 			kfree(pktopt->ip6po_hbh, M_IP6OPT);
2054 		pktopt->ip6po_hbh = NULL;
2055 	}
2056 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2057 		if (pktopt->ip6po_dest1)
2058 			kfree(pktopt->ip6po_dest1, M_IP6OPT);
2059 		pktopt->ip6po_dest1 = NULL;
2060 	}
2061 	if (optname == -1 || optname == IPV6_RTHDR) {
2062 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2063 			kfree(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2064 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2065 		if (pktopt->ip6po_route.ro_rt) {
2066 			RTFREE(pktopt->ip6po_route.ro_rt);
2067 			pktopt->ip6po_route.ro_rt = NULL;
2068 		}
2069 	}
2070 	if (optname == -1 || optname == IPV6_DSTOPTS) {
2071 		if (pktopt->ip6po_dest2)
2072 			kfree(pktopt->ip6po_dest2, M_IP6OPT);
2073 		pktopt->ip6po_dest2 = NULL;
2074 	}
2075 }
2076 
2077 #define PKTOPT_EXTHDRCPY(type) \
2078 do {\
2079 	if (src->type) {\
2080 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2081 		dst->type = kmalloc(hlen, M_IP6OPT, canwait);\
2082 		if (dst->type == NULL)\
2083 			goto bad;\
2084 		bcopy(src->type, dst->type, hlen);\
2085 	}\
2086 } while (0)
2087 
2088 struct ip6_pktopts *
2089 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2090 {
2091 	struct ip6_pktopts *dst;
2092 
2093 	if (src == NULL) {
2094 		kprintf("ip6_clearpktopts: invalid argument\n");
2095 		return (NULL);
2096 	}
2097 
2098 	dst = kmalloc(sizeof(*dst), M_IP6OPT, canwait | M_ZERO);
2099 	if (dst == NULL)
2100 		return (NULL);
2101 
2102 	dst->ip6po_hlim = src->ip6po_hlim;
2103 	if (src->ip6po_pktinfo) {
2104 		dst->ip6po_pktinfo = kmalloc(sizeof(*dst->ip6po_pktinfo),
2105 		    M_IP6OPT, canwait);
2106 		if (dst->ip6po_pktinfo == NULL)
2107 			goto bad;
2108 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2109 	}
2110 	if (src->ip6po_nexthop) {
2111 		dst->ip6po_nexthop = kmalloc(src->ip6po_nexthop->sa_len,
2112 		    M_IP6OPT, canwait);
2113 		if (dst->ip6po_nexthop == NULL)
2114 			goto bad;
2115 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2116 		    src->ip6po_nexthop->sa_len);
2117 	}
2118 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2119 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2120 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2121 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2122 	return (dst);
2123 
2124 bad:
2125 	if (dst->ip6po_pktinfo) kfree(dst->ip6po_pktinfo, M_IP6OPT);
2126 	if (dst->ip6po_nexthop) kfree(dst->ip6po_nexthop, M_IP6OPT);
2127 	if (dst->ip6po_hbh) kfree(dst->ip6po_hbh, M_IP6OPT);
2128 	if (dst->ip6po_dest1) kfree(dst->ip6po_dest1, M_IP6OPT);
2129 	if (dst->ip6po_dest2) kfree(dst->ip6po_dest2, M_IP6OPT);
2130 	if (dst->ip6po_rthdr) kfree(dst->ip6po_rthdr, M_IP6OPT);
2131 	kfree(dst, M_IP6OPT);
2132 	return (NULL);
2133 }
2134 
2135 static int
2136 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2137 {
2138 	if (dst == NULL || src == NULL)  {
2139 #ifdef DIAGNOSTIC
2140 		kprintf("ip6_clearpktopts: invalid argument\n");
2141 #endif
2142 		return (EINVAL);
2143 	}
2144 
2145 	dst->ip6po_hlim = src->ip6po_hlim;
2146 	dst->ip6po_tclass = src->ip6po_tclass;
2147 	dst->ip6po_flags = src->ip6po_flags;
2148 	if (src->ip6po_pktinfo) {
2149 		dst->ip6po_pktinfo = kmalloc(sizeof(*dst->ip6po_pktinfo),
2150 		    M_IP6OPT, canwait);
2151 		if (dst->ip6po_pktinfo == NULL)
2152 			goto bad;
2153 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2154 	}
2155 	if (src->ip6po_nexthop) {
2156 		dst->ip6po_nexthop = kmalloc(src->ip6po_nexthop->sa_len,
2157 		    M_IP6OPT, canwait);
2158 		if (dst->ip6po_nexthop == NULL)
2159 			goto bad;
2160 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2161 		    src->ip6po_nexthop->sa_len);
2162 	}
2163 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2164 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2165 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2166 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2167 	return (0);
2168 
2169   bad:
2170 	ip6_clearpktopts(dst, -1);
2171 	return (ENOBUFS);
2172 }
2173 #undef PKTOPT_EXTHDRCPY
2174 
2175 void
2176 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2177 {
2178 	if (pktopt == NULL)
2179 		return;
2180 
2181 	ip6_clearpktopts(pktopt, -1);
2182 
2183 	kfree(pktopt, M_IP6OPT);
2184 }
2185 
2186 /*
2187  * Set the IP6 multicast options in response to user setsockopt().
2188  */
2189 static int
2190 ip6_setmoptions(int optname, struct ip6_moptions **im6op, struct mbuf *m)
2191 {
2192 	int error = 0;
2193 	u_int loop, ifindex;
2194 	struct ipv6_mreq *mreq;
2195 	struct ifnet *ifp;
2196 	struct ip6_moptions *im6o = *im6op;
2197 	struct route_in6 ro;
2198 	struct sockaddr_in6 *dst;
2199 	struct in6_multi_mship *imm;
2200 	struct thread *td = curthread;
2201 
2202 	if (im6o == NULL) {
2203 		/*
2204 		 * No multicast option buffer attached to the pcb;
2205 		 * allocate one and initialize to default values.
2206 		 */
2207 		im6o = (struct ip6_moptions *)
2208 			kmalloc(sizeof(*im6o), M_IPMOPTS, M_WAITOK);
2209 
2210 		*im6op = im6o;
2211 		im6o->im6o_multicast_ifp = NULL;
2212 		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2213 		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
2214 		LIST_INIT(&im6o->im6o_memberships);
2215 	}
2216 
2217 	switch (optname) {
2218 
2219 	case IPV6_MULTICAST_IF:
2220 		/*
2221 		 * Select the interface for outgoing multicast packets.
2222 		 */
2223 		if (m == NULL || m->m_len != sizeof(u_int)) {
2224 			error = EINVAL;
2225 			break;
2226 		}
2227 		bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
2228 		if (ifindex < 0 || if_index < ifindex) {
2229 			error = ENXIO;	/* XXX EINVAL? */
2230 			break;
2231 		}
2232 		ifp = ifindex2ifnet[ifindex];
2233 		if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
2234 			error = EADDRNOTAVAIL;
2235 			break;
2236 		}
2237 		im6o->im6o_multicast_ifp = ifp;
2238 		break;
2239 
2240 	case IPV6_MULTICAST_HOPS:
2241 	    {
2242 		/*
2243 		 * Set the IP6 hoplimit for outgoing multicast packets.
2244 		 */
2245 		int optval;
2246 		if (m == NULL || m->m_len != sizeof(int)) {
2247 			error = EINVAL;
2248 			break;
2249 		}
2250 		bcopy(mtod(m, u_int *), &optval, sizeof(optval));
2251 		if (optval < -1 || optval >= 256)
2252 			error = EINVAL;
2253 		else if (optval == -1)
2254 			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2255 		else
2256 			im6o->im6o_multicast_hlim = optval;
2257 		break;
2258 	    }
2259 
2260 	case IPV6_MULTICAST_LOOP:
2261 		/*
2262 		 * Set the loopback flag for outgoing multicast packets.
2263 		 * Must be zero or one.
2264 		 */
2265 		if (m == NULL || m->m_len != sizeof(u_int)) {
2266 			error = EINVAL;
2267 			break;
2268 		}
2269 		bcopy(mtod(m, u_int *), &loop, sizeof(loop));
2270 		if (loop > 1) {
2271 			error = EINVAL;
2272 			break;
2273 		}
2274 		im6o->im6o_multicast_loop = loop;
2275 		break;
2276 
2277 	case IPV6_JOIN_GROUP:
2278 		/*
2279 		 * Add a multicast group membership.
2280 		 * Group must be a valid IP6 multicast address.
2281 		 */
2282 		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2283 			error = EINVAL;
2284 			break;
2285 		}
2286 		mreq = mtod(m, struct ipv6_mreq *);
2287 		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2288 			/*
2289 			 * We use the unspecified address to specify to accept
2290 			 * all multicast addresses. Only super user is allowed
2291 			 * to do this.
2292 			 */
2293 			if (priv_check(td, PRIV_ROOT)) {
2294 				error = EACCES;
2295 				break;
2296 			}
2297 		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2298 			error = EINVAL;
2299 			break;
2300 		}
2301 
2302 		/*
2303 		 * If the interface is specified, validate it.
2304 		 */
2305 		if (mreq->ipv6mr_interface < 0
2306 		 || if_index < mreq->ipv6mr_interface) {
2307 			error = ENXIO;	/* XXX EINVAL? */
2308 			break;
2309 		}
2310 		/*
2311 		 * If no interface was explicitly specified, choose an
2312 		 * appropriate one according to the given multicast address.
2313 		 */
2314 		if (mreq->ipv6mr_interface == 0) {
2315 			/*
2316 			 * If the multicast address is in node-local scope,
2317 			 * the interface should be a loopback interface.
2318 			 * Otherwise, look up the routing table for the
2319 			 * address, and choose the outgoing interface.
2320 			 *   XXX: is it a good approach?
2321 			 */
2322 			if (IN6_IS_ADDR_MC_INTFACELOCAL(&mreq->ipv6mr_multiaddr)) {
2323 				ifp = loif;
2324 			} else {
2325 				ro.ro_rt = NULL;
2326 				dst = (struct sockaddr_in6 *)&ro.ro_dst;
2327 				bzero(dst, sizeof(*dst));
2328 				dst->sin6_len = sizeof(struct sockaddr_in6);
2329 				dst->sin6_family = AF_INET6;
2330 				dst->sin6_addr = mreq->ipv6mr_multiaddr;
2331 				rtalloc((struct route *)&ro);
2332 				if (ro.ro_rt == NULL) {
2333 					error = EADDRNOTAVAIL;
2334 					break;
2335 				}
2336 				ifp = ro.ro_rt->rt_ifp;
2337 				rtfree(ro.ro_rt);
2338 			}
2339 		} else
2340 			ifp = ifindex2ifnet[mreq->ipv6mr_interface];
2341 
2342 		/*
2343 		 * See if we found an interface, and confirm that it
2344 		 * supports multicast
2345 		 */
2346 		if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
2347 			error = EADDRNOTAVAIL;
2348 			break;
2349 		}
2350 		/*
2351 		 * Put interface index into the multicast address,
2352 		 * if the address has link-local scope.
2353 		 */
2354 		if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
2355 			mreq->ipv6mr_multiaddr.s6_addr16[1]
2356 				= htons(mreq->ipv6mr_interface);
2357 		}
2358 		/*
2359 		 * See if the membership already exists.
2360 		 */
2361 		for (imm = im6o->im6o_memberships.lh_first;
2362 		     imm != NULL; imm = imm->i6mm_chain.le_next)
2363 			if (imm->i6mm_maddr->in6m_ifp == ifp &&
2364 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2365 					       &mreq->ipv6mr_multiaddr))
2366 				break;
2367 		if (imm != NULL) {
2368 			error = EADDRINUSE;
2369 			break;
2370 		}
2371 		/*
2372 		 * Everything looks good; add a new record to the multicast
2373 		 * address list for the given interface.
2374 		 */
2375 		imm = kmalloc(sizeof(*imm), M_IPMADDR, M_WAITOK);
2376 		if ((imm->i6mm_maddr =
2377 		     in6_addmulti(&mreq->ipv6mr_multiaddr, ifp, &error)) == NULL) {
2378 			kfree(imm, M_IPMADDR);
2379 			break;
2380 		}
2381 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
2382 		break;
2383 
2384 	case IPV6_LEAVE_GROUP:
2385 		/*
2386 		 * Drop a multicast group membership.
2387 		 * Group must be a valid IP6 multicast address.
2388 		 */
2389 		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2390 			error = EINVAL;
2391 			break;
2392 		}
2393 		mreq = mtod(m, struct ipv6_mreq *);
2394 		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2395 			if (priv_check(td, PRIV_ROOT)) {
2396 				error = EACCES;
2397 				break;
2398 			}
2399 		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2400 			error = EINVAL;
2401 			break;
2402 		}
2403 		/*
2404 		 * If an interface address was specified, get a pointer
2405 		 * to its ifnet structure.
2406 		 */
2407 		if (mreq->ipv6mr_interface < 0
2408 		 || if_index < mreq->ipv6mr_interface) {
2409 			error = ENXIO;	/* XXX EINVAL? */
2410 			break;
2411 		}
2412 		ifp = ifindex2ifnet[mreq->ipv6mr_interface];
2413 		/*
2414 		 * Put interface index into the multicast address,
2415 		 * if the address has link-local scope.
2416 		 */
2417 		if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
2418 			mreq->ipv6mr_multiaddr.s6_addr16[1]
2419 				= htons(mreq->ipv6mr_interface);
2420 		}
2421 
2422 		/*
2423 		 * Find the membership in the membership list.
2424 		 */
2425 		for (imm = im6o->im6o_memberships.lh_first;
2426 		     imm != NULL; imm = imm->i6mm_chain.le_next) {
2427 			if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
2428 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2429 			    &mreq->ipv6mr_multiaddr))
2430 				break;
2431 		}
2432 		if (imm == NULL) {
2433 			/* Unable to resolve interface */
2434 			error = EADDRNOTAVAIL;
2435 			break;
2436 		}
2437 		/*
2438 		 * Give up the multicast address record to which the
2439 		 * membership points.
2440 		 */
2441 		LIST_REMOVE(imm, i6mm_chain);
2442 		in6_delmulti(imm->i6mm_maddr);
2443 		kfree(imm, M_IPMADDR);
2444 		break;
2445 
2446 	default:
2447 		error = EOPNOTSUPP;
2448 		break;
2449 	}
2450 
2451 	/*
2452 	 * If all options have default values, no need to keep the mbuf.
2453 	 */
2454 	if (im6o->im6o_multicast_ifp == NULL &&
2455 	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
2456 	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
2457 	    im6o->im6o_memberships.lh_first == NULL) {
2458 		kfree(*im6op, M_IPMOPTS);
2459 		*im6op = NULL;
2460 	}
2461 
2462 	return (error);
2463 }
2464 
2465 /*
2466  * Return the IP6 multicast options in response to user getsockopt().
2467  */
2468 static int
2469 ip6_getmoptions(int optname, struct ip6_moptions *im6o, struct mbuf **mp)
2470 {
2471 	u_int *hlim, *loop, *ifindex;
2472 
2473 	*mp = m_get(M_WAITOK, MT_HEADER);		/* XXX */
2474 
2475 	switch (optname) {
2476 
2477 	case IPV6_MULTICAST_IF:
2478 		ifindex = mtod(*mp, u_int *);
2479 		(*mp)->m_len = sizeof(u_int);
2480 		if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
2481 			*ifindex = 0;
2482 		else
2483 			*ifindex = im6o->im6o_multicast_ifp->if_index;
2484 		return (0);
2485 
2486 	case IPV6_MULTICAST_HOPS:
2487 		hlim = mtod(*mp, u_int *);
2488 		(*mp)->m_len = sizeof(u_int);
2489 		if (im6o == NULL)
2490 			*hlim = ip6_defmcasthlim;
2491 		else
2492 			*hlim = im6o->im6o_multicast_hlim;
2493 		return (0);
2494 
2495 	case IPV6_MULTICAST_LOOP:
2496 		loop = mtod(*mp, u_int *);
2497 		(*mp)->m_len = sizeof(u_int);
2498 		if (im6o == NULL)
2499 			*loop = ip6_defmcasthlim;
2500 		else
2501 			*loop = im6o->im6o_multicast_loop;
2502 		return (0);
2503 
2504 	default:
2505 		return (EOPNOTSUPP);
2506 	}
2507 }
2508 
2509 /*
2510  * Discard the IP6 multicast options.
2511  */
2512 void
2513 ip6_freemoptions(struct ip6_moptions *im6o)
2514 {
2515 	struct in6_multi_mship *imm;
2516 
2517 	if (im6o == NULL)
2518 		return;
2519 
2520 	while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
2521 		LIST_REMOVE(imm, i6mm_chain);
2522 		if (imm->i6mm_maddr)
2523 			in6_delmulti(imm->i6mm_maddr);
2524 		kfree(imm, M_IPMADDR);
2525 	}
2526 	kfree(im6o, M_IPMOPTS);
2527 }
2528 
2529 /*
2530  * Set a particular packet option, as a sticky option or an ancillary data
2531  * item.  "len" can be 0 only when it's a sticky option.
2532  * We have 4 cases of combination of "sticky" and "cmsg":
2533  * "sticky=0, cmsg=0": impossible
2534  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2535  * "sticky=1, cmsg=0": RFC3542 socket option
2536  * "sticky=1, cmsg=1": RFC2292 socket option
2537  */
2538 static int
2539 ip6_setpktoption(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2540      int sticky, int cmsg, int uproto, int priv)
2541 {
2542 	int minmtupolicy, preftemp;
2543 	//int error;
2544 
2545 	if (!sticky && !cmsg) {
2546 		kprintf("ip6_setpktoption: impossible case\n");
2547 		return (EINVAL);
2548 	}
2549 
2550 	/*
2551 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2552 	 * not be specified in the context of RFC3542.  Conversely,
2553 	 * RFC3542 types should not be specified in the context of RFC2292.
2554 	 */
2555 	if (!cmsg) {
2556 		switch (optname) {
2557 		case IPV6_2292PKTINFO:
2558 		case IPV6_2292HOPLIMIT:
2559 		case IPV6_2292NEXTHOP:
2560 		case IPV6_2292HOPOPTS:
2561 		case IPV6_2292DSTOPTS:
2562 		case IPV6_2292RTHDR:
2563 		case IPV6_2292PKTOPTIONS:
2564 			return (ENOPROTOOPT);
2565 		}
2566 	}
2567 	if (sticky && cmsg) {
2568 		switch (optname) {
2569 		case IPV6_PKTINFO:
2570 		case IPV6_HOPLIMIT:
2571 		case IPV6_NEXTHOP:
2572 		case IPV6_HOPOPTS:
2573 		case IPV6_DSTOPTS:
2574 		case IPV6_RTHDRDSTOPTS:
2575 		case IPV6_RTHDR:
2576 		case IPV6_USE_MIN_MTU:
2577 		case IPV6_DONTFRAG:
2578 		case IPV6_TCLASS:
2579 		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2580 			return (ENOPROTOOPT);
2581 		}
2582 	}
2583 
2584 	switch (optname) {
2585 	case IPV6_2292PKTINFO:
2586 	case IPV6_PKTINFO:
2587 	{
2588 		struct in6_pktinfo *pktinfo;
2589 		if (len != sizeof(struct in6_pktinfo))
2590 			return (EINVAL);
2591 		pktinfo = (struct in6_pktinfo *)buf;
2592 
2593 		/*
2594 		 * An application can clear any sticky IPV6_PKTINFO option by
2595 		 * doing a "regular" setsockopt with ipi6_addr being
2596 		 * in6addr_any and ipi6_ifindex being zero.
2597 		 * [RFC 3542, Section 6]
2598 		 */
2599 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2600 		    pktinfo->ipi6_ifindex == 0 &&
2601 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2602 			ip6_clearpktopts(opt, optname);
2603 			break;
2604 		}
2605 
2606 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2607 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2608 			return (EINVAL);
2609 		}
2610 
2611 		/* validate the interface index if specified. */
2612 		if (pktinfo->ipi6_ifindex > if_index ||
2613 		    pktinfo->ipi6_ifindex < 0) {
2614 			 return (ENXIO);
2615 		}
2616 		/*
2617 		 * Check if the requested source address is indeed a
2618 		 * unicast address assigned to the node, and can be
2619 		 * used as the packet's source address.
2620 		 */
2621 		if (opt->ip6po_pktinfo != NULL &&
2622 		    !IN6_IS_ADDR_UNSPECIFIED(&opt->ip6po_pktinfo->ipi6_addr)) {
2623 			struct in6_ifaddr *ia6;
2624 			struct sockaddr_in6 sin6;
2625 
2626 			bzero(&sin6, sizeof(sin6));
2627 			sin6.sin6_len = sizeof(sin6);
2628 			sin6.sin6_family = AF_INET6;
2629 			sin6.sin6_addr =
2630 			opt->ip6po_pktinfo->ipi6_addr;
2631 			ia6 = (struct in6_ifaddr *)ifa_ifwithaddr(sin6tosa(&sin6));
2632 			if (ia6 == NULL ||
2633 				(ia6->ia6_flags & (IN6_IFF_ANYCAST |
2634 					IN6_IFF_NOTREADY)) != 0)
2635 			return (EADDRNOTAVAIL);
2636 		}
2637 
2638 		/*
2639 		 * We store the address anyway, and let in6_selectsrc()
2640 		 * validate the specified address.  This is because ipi6_addr
2641 		 * may not have enough information about its scope zone, and
2642 		 * we may need additional information (such as outgoing
2643 		 * interface or the scope zone of a destination address) to
2644 		 * disambiguate the scope.
2645 		 * XXX: the delay of the validation may confuse the
2646 		 * application when it is used as a sticky option.
2647 		 */
2648 		if (opt->ip6po_pktinfo == NULL) {
2649 			opt->ip6po_pktinfo = kmalloc(sizeof(*pktinfo),
2650 			    M_IP6OPT, M_NOWAIT);
2651 			if (opt->ip6po_pktinfo == NULL)
2652 				return (ENOBUFS);
2653 		}
2654 		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2655 		break;
2656 	}
2657 
2658 	case IPV6_2292HOPLIMIT:
2659 	case IPV6_HOPLIMIT:
2660 	{
2661 		int *hlimp;
2662 
2663 		/*
2664 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2665 		 * to simplify the ordering among hoplimit options.
2666 		 */
2667 		if (optname == IPV6_HOPLIMIT && sticky)
2668 			return (ENOPROTOOPT);
2669 
2670 		if (len != sizeof(int))
2671 			return (EINVAL);
2672 		hlimp = (int *)buf;
2673 		if (*hlimp < -1 || *hlimp > 255)
2674 			return (EINVAL);
2675 
2676 		opt->ip6po_hlim = *hlimp;
2677 		break;
2678 	}
2679 
2680 	case IPV6_TCLASS:
2681 	{
2682 		int tclass;
2683 
2684 		if (len != sizeof(int))
2685 			return (EINVAL);
2686 		tclass = *(int *)buf;
2687 		if (tclass < -1 || tclass > 255)
2688 			return (EINVAL);
2689 
2690 		opt->ip6po_tclass = tclass;
2691 		break;
2692 	}
2693 
2694 	case IPV6_2292NEXTHOP:
2695 	case IPV6_NEXTHOP:
2696 		if (!priv)
2697 			return (EPERM);
2698 
2699 		if (len == 0) {	/* just remove the option */
2700 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
2701 			break;
2702 		}
2703 
2704 		/* check if cmsg_len is large enough for sa_len */
2705 		if (len < sizeof(struct sockaddr) || len < *buf)
2706 			return (EINVAL);
2707 
2708 		switch (((struct sockaddr *)buf)->sa_family) {
2709 		case AF_INET6:
2710 		{
2711 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2712 			//int error;
2713 
2714 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2715 				return (EINVAL);
2716 
2717 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2718 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2719 				return (EINVAL);
2720 			}
2721 			break;
2722 		}
2723 		case AF_LINK:	/* should eventually be supported */
2724 		default:
2725 			return (EAFNOSUPPORT);
2726 		}
2727 
2728 		/* turn off the previous option, then set the new option. */
2729 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
2730 		opt->ip6po_nexthop = kmalloc(*buf, M_IP6OPT, M_NOWAIT);
2731 		if (opt->ip6po_nexthop == NULL)
2732 			return (ENOBUFS);
2733 		bcopy(buf, opt->ip6po_nexthop, *buf);
2734 		break;
2735 
2736 	case IPV6_2292HOPOPTS:
2737 	case IPV6_HOPOPTS:
2738 	{
2739 		struct ip6_hbh *hbh;
2740 		int hbhlen;
2741 
2742 		/*
2743 		 * XXX: We don't allow a non-privileged user to set ANY HbH
2744 		 * options, since per-option restriction has too much
2745 		 * overhead.
2746 		 */
2747 		if (!priv)
2748 			return (EPERM);
2749 		if (len == 0) {
2750 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
2751 			break;	/* just remove the option */
2752 		}
2753 
2754 		/* message length validation */
2755 		if (len < sizeof(struct ip6_hbh))
2756 			return (EINVAL);
2757 		hbh = (struct ip6_hbh *)buf;
2758 		hbhlen = (hbh->ip6h_len + 1) << 3;
2759 		if (len != hbhlen)
2760 			return (EINVAL);
2761 
2762 		/* turn off the previous option, then set the new option. */
2763 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
2764 		opt->ip6po_hbh = kmalloc(hbhlen, M_IP6OPT, M_NOWAIT);
2765 		if (opt->ip6po_hbh == NULL)
2766 			return (ENOBUFS);
2767 		bcopy(hbh, opt->ip6po_hbh, hbhlen);
2768 
2769 		break;
2770 	}
2771 
2772 	case IPV6_2292DSTOPTS:
2773 	case IPV6_DSTOPTS:
2774 	case IPV6_RTHDRDSTOPTS:
2775 	{
2776 		struct ip6_dest *dest, **newdest = NULL;
2777 		int destlen;
2778 		if (!priv)
2779 			return (EPERM);
2780 
2781 		if (len == 0) {
2782 			ip6_clearpktopts(opt, optname);
2783 			break;	/* just remove the option */
2784 		}
2785 
2786 		/* message length validation */
2787 		if (len < sizeof(struct ip6_dest))
2788 			return (EINVAL);
2789 		dest = (struct ip6_dest *)buf;
2790 		destlen = (dest->ip6d_len + 1) << 3;
2791 		if (len != destlen)
2792 			return (EINVAL);
2793 
2794 		/*
2795 		 * Determine the position that the destination options header
2796 		 * should be inserted; before or after the routing header.
2797 		 */
2798 		switch (optname) {
2799 		case IPV6_2292DSTOPTS:
2800 			/*
2801 			 * The old advacned API is ambiguous on this point.
2802 			 * Our approach is to determine the position based
2803 			 * according to the existence of a routing header.
2804 			 * Note, however, that this depends on the order of the
2805 			 * extension headers in the ancillary data; the 1st
2806 			 * part of the destination options header must appear
2807 			 * before the routing header in the ancillary data,
2808 			 * too.
2809 			 * RFC3542 solved the ambiguity by introducing
2810 			 * separate ancillary data or option types.
2811 			 */
2812 			if (opt->ip6po_rthdr == NULL)
2813 				newdest = &opt->ip6po_dest1;
2814 			else
2815 				newdest = &opt->ip6po_dest2;
2816 			break;
2817 		case IPV6_RTHDRDSTOPTS:
2818 			newdest = &opt->ip6po_dest1;
2819 			break;
2820 		case IPV6_DSTOPTS:
2821 			newdest = &opt->ip6po_dest2;
2822 			break;
2823 		}
2824 
2825 		/* turn off the previous option, then set the new option. */
2826 		ip6_clearpktopts(opt, optname);
2827 		*newdest = kmalloc(destlen, M_IP6OPT, M_NOWAIT);
2828 		if (*newdest == NULL)
2829 			return (ENOBUFS);
2830 		bcopy(dest, *newdest, destlen);
2831 
2832 		break;
2833 	}
2834 
2835 	case IPV6_2292RTHDR:
2836 	case IPV6_RTHDR:
2837 	{
2838 		struct ip6_rthdr *rth;
2839 		int rthlen;
2840 
2841 		if (len == 0) {
2842 			ip6_clearpktopts(opt, IPV6_RTHDR);
2843 			break;	/* just remove the option */
2844 		}
2845 
2846 		/* message length validation */
2847 		if (len < sizeof(struct ip6_rthdr))
2848 			return (EINVAL);
2849 		rth = (struct ip6_rthdr *)buf;
2850 		rthlen = (rth->ip6r_len + 1) << 3;
2851 		if (len != rthlen)
2852 			return (EINVAL);
2853 
2854 		switch (rth->ip6r_type) {
2855 		default:
2856 			return (EINVAL);	/* not supported */
2857 		}
2858 
2859 		/* turn off the previous option */
2860 		ip6_clearpktopts(opt, IPV6_RTHDR);
2861 		opt->ip6po_rthdr = kmalloc(rthlen, M_IP6OPT, M_NOWAIT);
2862 		if (opt->ip6po_rthdr == NULL)
2863 			return (ENOBUFS);
2864 		bcopy(rth, opt->ip6po_rthdr, rthlen);
2865 
2866 		break;
2867 	}
2868 
2869 	case IPV6_USE_MIN_MTU:
2870 		if (len != sizeof(int))
2871 			return (EINVAL);
2872 		minmtupolicy = *(int *)buf;
2873 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2874 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
2875 		    minmtupolicy != IP6PO_MINMTU_ALL) {
2876 			return (EINVAL);
2877 		}
2878 		opt->ip6po_minmtu = minmtupolicy;
2879 		break;
2880 
2881 	case IPV6_DONTFRAG:
2882 		if (len != sizeof(int))
2883 			return (EINVAL);
2884 
2885 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2886 			/*
2887 			 * we ignore this option for TCP sockets.
2888 			 * (RFC3542 leaves this case unspecified.)
2889 			 */
2890 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2891 		} else
2892 			opt->ip6po_flags |= IP6PO_DONTFRAG;
2893 		break;
2894 
2895 	case IPV6_PREFER_TEMPADDR:
2896 		if (len != sizeof(int))
2897 			return (EINVAL);
2898 		preftemp = *(int *)buf;
2899 		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2900 		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2901 		    preftemp != IP6PO_TEMPADDR_PREFER) {
2902 			return (EINVAL);
2903 		}
2904 		opt->ip6po_prefer_tempaddr = preftemp;
2905 		break;
2906 
2907 	default:
2908 		return (ENOPROTOOPT);
2909 	} /* end of switch */
2910 
2911 	return (0);
2912 }
2913 
2914 
2915 /*
2916  * Set IPv6 outgoing packet options based on advanced API.
2917  */
2918 int
2919 ip6_setpktoptions(struct mbuf *control, struct ip6_pktopts *opt,
2920     struct ip6_pktopts *stickyopt, int uproto, int priv)
2921 {
2922 	struct cmsghdr *cm = NULL;
2923 
2924 	if (control == NULL || opt == NULL)
2925 		return (EINVAL);
2926 
2927 	init_ip6pktopts(opt);
2928 
2929 	/*
2930 	 * XXX: Currently, we assume all the optional information is stored
2931 	 * in a single mbuf.
2932 	 */
2933 	if (stickyopt) {
2934 		int error;
2935 
2936 		/*
2937 		 * If stickyopt is provided, make a local copy of the options
2938 		 * for this particular packet, then override them by ancillary
2939 		 * objects.
2940 		 * XXX: copypktopts() does not copy the cached route to a next
2941 		 * hop (if any).  This is not very good in terms of efficiency,
2942 		 * but we can allow this since this option should be rarely
2943 		 * used.
2944 		 */
2945 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2946 			return (error);
2947 	}
2948 
2949 	/*
2950 	 * XXX: Currently, we assume all the optional information is stored
2951 	 * in a single mbuf.
2952 	 */
2953 	if (control->m_next)
2954 		return (EINVAL);
2955 
2956 	for (; control->m_len; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2957 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2958 		int error;
2959 
2960 		if (control->m_len < CMSG_LEN(0))
2961 			return (EINVAL);
2962 
2963 		cm = mtod(control, struct cmsghdr *);
2964 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2965 			return (EINVAL);
2966 		if (cm->cmsg_level != IPPROTO_IPV6)
2967 			continue;
2968 
2969 		error = ip6_setpktoption(cm->cmsg_type, CMSG_DATA(cm),
2970 		    cm->cmsg_len - CMSG_LEN(0), opt, 0, 1, uproto, priv);
2971 		if (error)
2972 			return (error);
2973 	}
2974 
2975 	return (0);
2976 }
2977 
2978 /*
2979  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2980  * packet to the input queue of a specified interface.  Note that this
2981  * calls the output routine of the loopback "driver", but with an interface
2982  * pointer that might NOT be loif -- easier than replicating that code here.
2983  */
2984 void
2985 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2986 {
2987 	struct mbuf *copym;
2988 	struct ip6_hdr *ip6;
2989 
2990 	copym = m_copy(m, 0, M_COPYALL);
2991 	if (copym == NULL)
2992 		return;
2993 
2994 	/*
2995 	 * Make sure to deep-copy IPv6 header portion in case the data
2996 	 * is in an mbuf cluster, so that we can safely override the IPv6
2997 	 * header portion later.
2998 	 */
2999 	if ((copym->m_flags & M_EXT) != 0 ||
3000 	    copym->m_len < sizeof(struct ip6_hdr)) {
3001 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
3002 		if (copym == NULL)
3003 			return;
3004 	}
3005 
3006 #ifdef DIAGNOSTIC
3007 	if (copym->m_len < sizeof(*ip6)) {
3008 		m_freem(copym);
3009 		return;
3010 	}
3011 #endif
3012 
3013 	ip6 = mtod(copym, struct ip6_hdr *);
3014 	/*
3015 	 * clear embedded scope identifiers if necessary.
3016 	 * in6_clearscope will touch the addresses only when necessary.
3017 	 */
3018 	in6_clearscope(&ip6->ip6_src);
3019 	in6_clearscope(&ip6->ip6_dst);
3020 
3021 	if_simloop(ifp, copym, dst->sin6_family, 0);
3022 }
3023 
3024 /*
3025  * Separate the IPv6 header from the payload into its own mbuf.
3026  *
3027  * Returns the new mbuf chain or the original mbuf if no payload.
3028  * Returns NULL if can't allocate new mbuf for header.
3029  */
3030 static struct mbuf *
3031 ip6_splithdr(struct mbuf *m)
3032 {
3033 	struct mbuf *mh;
3034 
3035 	if (m->m_len <= sizeof(struct ip6_hdr))		/* no payload */
3036 		return (m);
3037 
3038 	MGETHDR(mh, M_NOWAIT, MT_HEADER);
3039 	if (mh == NULL)
3040 		return (NULL);
3041 	mh->m_len = sizeof(struct ip6_hdr);
3042 	M_MOVE_PKTHDR(mh, m);
3043 	MH_ALIGN(mh, sizeof(struct ip6_hdr));
3044 	bcopy(mtod(m, caddr_t), mtod(mh, caddr_t), sizeof(struct ip6_hdr));
3045 	m->m_data += sizeof(struct ip6_hdr);
3046 	m->m_len -= sizeof(struct ip6_hdr);
3047 	mh->m_next = m;
3048 	return (mh);
3049 }
3050 
3051 /*
3052  * Compute IPv6 extension header length.
3053  */
3054 int
3055 ip6_optlen(struct in6pcb *in6p)
3056 {
3057 	int len;
3058 
3059 	if (!in6p->in6p_outputopts)
3060 		return 0;
3061 
3062 	len = 0;
3063 #define elen(x) \
3064     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3065 
3066 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
3067 	if (in6p->in6p_outputopts->ip6po_rthdr)
3068 		/* dest1 is valid with rthdr only */
3069 		len += elen(in6p->in6p_outputopts->ip6po_dest1);
3070 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3071 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
3072 	return len;
3073 #undef elen
3074 }
3075