xref: /dragonfly/sys/netinet6/ip6_output.c (revision 6bd457ed)
1 /*	$FreeBSD: src/sys/netinet6/ip6_output.c,v 1.13.2.18 2003/01/24 05:11:35 sam Exp $	*/
2 /*	$DragonFly: src/sys/netinet6/ip6_output.c,v 1.18 2005/02/08 22:56:19 hsu Exp $	*/
3 /*	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1982, 1986, 1988, 1990, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *	This product includes software developed by the University of
49  *	California, Berkeley and its contributors.
50  * 4. Neither the name of the University nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64  * SUCH DAMAGE.
65  *
66  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
67  */
68 
69 #include "opt_ip6fw.h"
70 #include "opt_inet.h"
71 #include "opt_inet6.h"
72 #include "opt_ipsec.h"
73 
74 #include <sys/param.h>
75 #include <sys/malloc.h>
76 #include <sys/mbuf.h>
77 #include <sys/errno.h>
78 #include <sys/protosw.h>
79 #include <sys/socket.h>
80 #include <sys/socketvar.h>
81 #include <sys/systm.h>
82 #include <sys/kernel.h>
83 #include <sys/proc.h>
84 
85 #include <net/if.h>
86 #include <net/route.h>
87 #include <net/pfil.h>
88 
89 #include <netinet/in.h>
90 #include <netinet/in_var.h>
91 #include <netinet6/in6_var.h>
92 #include <netinet/ip6.h>
93 #include <netinet/icmp6.h>
94 #include <netinet6/ip6_var.h>
95 #include <netinet/in_pcb.h>
96 #include <netinet6/nd6.h>
97 
98 #ifdef IPSEC
99 #include <netinet6/ipsec.h>
100 #ifdef INET6
101 #include <netinet6/ipsec6.h>
102 #endif
103 #include <netproto/key/key.h>
104 #endif /* IPSEC */
105 
106 #ifdef FAST_IPSEC
107 #include <netproto/ipsec/ipsec.h>
108 #include <netproto/ipsec/ipsec6.h>
109 #include <netproto/ipsec/key.h>
110 #endif /* FAST_IPSEC */
111 
112 #include <net/ip6fw/ip6_fw.h>
113 
114 #include <net/net_osdep.h>
115 
116 static MALLOC_DEFINE(M_IPMOPTS, "ip6_moptions", "internet multicast options");
117 
118 struct ip6_exthdrs {
119 	struct mbuf *ip6e_ip6;
120 	struct mbuf *ip6e_hbh;
121 	struct mbuf *ip6e_dest1;
122 	struct mbuf *ip6e_rthdr;
123 	struct mbuf *ip6e_dest2;
124 };
125 
126 static int ip6_pcbopts (struct ip6_pktopts **, struct mbuf *,
127 			    struct socket *, struct sockopt *sopt);
128 static int ip6_setmoptions (int, struct ip6_moptions **, struct mbuf *);
129 static int ip6_getmoptions (int, struct ip6_moptions *, struct mbuf **);
130 static int ip6_copyexthdr (struct mbuf **, caddr_t, int);
131 static int ip6_insertfraghdr (struct mbuf *, struct mbuf *, int,
132 				  struct ip6_frag **);
133 static int ip6_insert_jumboopt (struct ip6_exthdrs *, u_int32_t);
134 static int ip6_splithdr (struct mbuf *, struct ip6_exthdrs *);
135 
136 /*
137  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
138  * header (with pri, len, nxt, hlim, src, dst).
139  * This function may modify ver and hlim only.
140  * The mbuf chain containing the packet will be freed.
141  * The mbuf opt, if present, will not be freed.
142  *
143  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
144  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
145  * which is rt_rmx.rmx_mtu.
146  */
147 int
148 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt, struct route_in6 *ro,
149 	   int flags, struct ip6_moptions *im6o,
150 	   struct ifnet **ifpp,		/* XXX: just for statistics */
151 	   struct inpcb *inp)
152 {
153 	struct ip6_hdr *ip6, *mhip6;
154 	struct ifnet *ifp, *origifp;
155 	struct mbuf *m = m0;
156 	int hlen, tlen, len, off;
157 	struct route_in6 ip6route;
158 	struct sockaddr_in6 *dst;
159 	int error = 0;
160 	struct in6_ifaddr *ia = NULL;
161 	u_long mtu;
162 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
163 	struct ip6_exthdrs exthdrs;
164 	struct in6_addr finaldst;
165 	struct route_in6 *ro_pmtu = NULL;
166 	int hdrsplit = 0;
167 	int needipsec = 0;
168 #ifdef IPSEC
169 	int needipsectun = 0;
170 	struct secpolicy *sp = NULL;
171 	struct socket *so = inp ? inp->inp_socket : NULL;
172 
173 	ip6 = mtod(m, struct ip6_hdr *);
174 #endif /* IPSEC */
175 #ifdef FAST_IPSEC
176 	int needipsectun = 0;
177 	struct secpolicy *sp = NULL;
178 
179 	ip6 = mtod(m, struct ip6_hdr *);
180 #endif /* FAST_IPSEC */
181 
182 #define MAKE_EXTHDR(hp, mp)						\
183     do {								\
184 	if (hp) {							\
185 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
186 		error = ip6_copyexthdr((mp), (caddr_t)(hp), 		\
187 				       ((eh)->ip6e_len + 1) << 3);	\
188 		if (error)						\
189 			goto freehdrs;					\
190 	}								\
191     } while (0)
192 
193 	bzero(&exthdrs, sizeof(exthdrs));
194 
195 	if (opt) {
196 		/* Hop-by-Hop options header */
197 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
198 		/* Destination options header(1st part) */
199 		MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
200 		/* Routing header */
201 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
202 		/* Destination options header(2nd part) */
203 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
204 	}
205 
206 #ifdef IPSEC
207 	/* get a security policy for this packet */
208 	if (so == NULL)
209 		sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
210 	else
211 		sp = ipsec6_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
212 
213 	if (sp == NULL) {
214 		ipsec6stat.out_inval++;
215 		goto freehdrs;
216 	}
217 
218 	error = 0;
219 
220 	/* check policy */
221 	switch (sp->policy) {
222 	case IPSEC_POLICY_DISCARD:
223 		/*
224 		 * This packet is just discarded.
225 		 */
226 		ipsec6stat.out_polvio++;
227 		goto freehdrs;
228 
229 	case IPSEC_POLICY_BYPASS:
230 	case IPSEC_POLICY_NONE:
231 		/* no need to do IPsec. */
232 		needipsec = 0;
233 		break;
234 
235 	case IPSEC_POLICY_IPSEC:
236 		if (sp->req == NULL) {
237 			/* acquire a policy */
238 			error = key_spdacquire(sp);
239 			goto freehdrs;
240 		}
241 		needipsec = 1;
242 		break;
243 
244 	case IPSEC_POLICY_ENTRUST:
245 	default:
246 		printf("ip6_output: Invalid policy found. %d\n", sp->policy);
247 	}
248 #endif /* IPSEC */
249 #ifdef FAST_IPSEC
250 	/* get a security policy for this packet */
251 	if (inp == NULL)
252 		sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
253 	else
254 		sp = ipsec_getpolicybysock(m, IPSEC_DIR_OUTBOUND, inp, &error);
255 
256 	if (sp == NULL) {
257 		newipsecstat.ips_out_inval++;
258 		goto freehdrs;
259 	}
260 
261 	error = 0;
262 
263 	/* check policy */
264 	switch (sp->policy) {
265 	case IPSEC_POLICY_DISCARD:
266 		/*
267 		 * This packet is just discarded.
268 		 */
269 		newipsecstat.ips_out_polvio++;
270 		goto freehdrs;
271 
272 	case IPSEC_POLICY_BYPASS:
273 	case IPSEC_POLICY_NONE:
274 		/* no need to do IPsec. */
275 		needipsec = 0;
276 		break;
277 
278 	case IPSEC_POLICY_IPSEC:
279 		if (sp->req == NULL) {
280 			/* acquire a policy */
281 			error = key_spdacquire(sp);
282 			goto freehdrs;
283 		}
284 		needipsec = 1;
285 		break;
286 
287 	case IPSEC_POLICY_ENTRUST:
288 	default:
289 		printf("ip6_output: Invalid policy found. %d\n", sp->policy);
290 	}
291 #endif /* FAST_IPSEC */
292 
293 	/*
294 	 * Calculate the total length of the extension header chain.
295 	 * Keep the length of the unfragmentable part for fragmentation.
296 	 */
297 	optlen = 0;
298 	if (exthdrs.ip6e_hbh) optlen += exthdrs.ip6e_hbh->m_len;
299 	if (exthdrs.ip6e_dest1) optlen += exthdrs.ip6e_dest1->m_len;
300 	if (exthdrs.ip6e_rthdr) optlen += exthdrs.ip6e_rthdr->m_len;
301 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
302 	/* NOTE: we don't add AH/ESP length here. do that later. */
303 	if (exthdrs.ip6e_dest2) optlen += exthdrs.ip6e_dest2->m_len;
304 
305 	/*
306 	 * If we need IPsec, or there is at least one extension header,
307 	 * separate IP6 header from the payload.
308 	 */
309 	if ((needipsec || optlen) && !hdrsplit) {
310 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
311 			m = NULL;
312 			goto freehdrs;
313 		}
314 		m = exthdrs.ip6e_ip6;
315 		hdrsplit++;
316 	}
317 
318 	/* adjust pointer */
319 	ip6 = mtod(m, struct ip6_hdr *);
320 
321 	/* adjust mbuf packet header length */
322 	m->m_pkthdr.len += optlen;
323 	plen = m->m_pkthdr.len - sizeof(*ip6);
324 
325 	/* If this is a jumbo payload, insert a jumbo payload option. */
326 	if (plen > IPV6_MAXPACKET) {
327 		if (!hdrsplit) {
328 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
329 				m = NULL;
330 				goto freehdrs;
331 			}
332 			m = exthdrs.ip6e_ip6;
333 			hdrsplit++;
334 		}
335 		/* adjust pointer */
336 		ip6 = mtod(m, struct ip6_hdr *);
337 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
338 			goto freehdrs;
339 		ip6->ip6_plen = 0;
340 	} else
341 		ip6->ip6_plen = htons(plen);
342 
343 	/*
344 	 * Concatenate headers and fill in next header fields.
345 	 * Here we have, on "m"
346 	 *	IPv6 payload
347 	 * and we insert headers accordingly.  Finally, we should be getting:
348 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
349 	 *
350 	 * during the header composing process, "m" points to IPv6 header.
351 	 * "mprev" points to an extension header prior to esp.
352 	 */
353 	{
354 		u_char *nexthdrp = &ip6->ip6_nxt;
355 		struct mbuf *mprev = m;
356 
357 		/*
358 		 * we treat dest2 specially.  this makes IPsec processing
359 		 * much easier.  the goal here is to make mprev point the
360 		 * mbuf prior to dest2.
361 		 *
362 		 * result: IPv6 dest2 payload
363 		 * m and mprev will point to IPv6 header.
364 		 */
365 		if (exthdrs.ip6e_dest2) {
366 			if (!hdrsplit)
367 				panic("assumption failed: hdr not split");
368 			exthdrs.ip6e_dest2->m_next = m->m_next;
369 			m->m_next = exthdrs.ip6e_dest2;
370 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
371 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
372 		}
373 
374 #define MAKE_CHAIN(m, mp, p, i)\
375     do {\
376 	if (m) {\
377 		if (!hdrsplit) \
378 			panic("assumption failed: hdr not split"); \
379 		*mtod((m), u_char *) = *(p);\
380 		*(p) = (i);\
381 		p = mtod((m), u_char *);\
382 		(m)->m_next = (mp)->m_next;\
383 		(mp)->m_next = (m);\
384 		(mp) = (m);\
385 	}\
386     } while (0)
387 		/*
388 		 * result: IPv6 hbh dest1 rthdr dest2 payload
389 		 * m will point to IPv6 header.  mprev will point to the
390 		 * extension header prior to dest2 (rthdr in the above case).
391 		 */
392 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev,
393 			   nexthdrp, IPPROTO_HOPOPTS);
394 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev,
395 			   nexthdrp, IPPROTO_DSTOPTS);
396 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev,
397 			   nexthdrp, IPPROTO_ROUTING);
398 
399 #if defined(IPSEC) || defined(FAST_IPSEC)
400 		if (!needipsec)
401 			goto skip_ipsec2;
402 
403 		/*
404 		 * pointers after IPsec headers are not valid any more.
405 		 * other pointers need a great care too.
406 		 * (IPsec routines should not mangle mbufs prior to AH/ESP)
407 		 */
408 		exthdrs.ip6e_dest2 = NULL;
409 
410 	    {
411 		struct ip6_rthdr *rh = NULL;
412 		int segleft_org = 0;
413 		struct ipsec_output_state state;
414 
415 		if (exthdrs.ip6e_rthdr) {
416 			rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
417 			segleft_org = rh->ip6r_segleft;
418 			rh->ip6r_segleft = 0;
419 		}
420 
421 		bzero(&state, sizeof(state));
422 		state.m = m;
423 		error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
424 			&needipsectun);
425 		m = state.m;
426 		if (error) {
427 			/* mbuf is already reclaimed in ipsec6_output_trans. */
428 			m = NULL;
429 			switch (error) {
430 			case EHOSTUNREACH:
431 			case ENETUNREACH:
432 			case EMSGSIZE:
433 			case ENOBUFS:
434 			case ENOMEM:
435 				break;
436 			default:
437 				printf("ip6_output (ipsec): error code %d\n", error);
438 				/* fall through */
439 			case ENOENT:
440 				/* don't show these error codes to the user */
441 				error = 0;
442 				break;
443 			}
444 			goto bad;
445 		}
446 		if (exthdrs.ip6e_rthdr) {
447 			/* ah6_output doesn't modify mbuf chain */
448 			rh->ip6r_segleft = segleft_org;
449 		}
450 	    }
451 skip_ipsec2:;
452 #endif
453 	}
454 
455 	/*
456 	 * If there is a routing header, replace destination address field
457 	 * with the first hop of the routing header.
458 	 */
459 	if (exthdrs.ip6e_rthdr) {
460 		struct ip6_rthdr *rh =
461 			(struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
462 						  struct ip6_rthdr *));
463 		struct ip6_rthdr0 *rh0;
464 
465 		finaldst = ip6->ip6_dst;
466 		switch (rh->ip6r_type) {
467 		case IPV6_RTHDR_TYPE_0:
468 			 rh0 = (struct ip6_rthdr0 *)rh;
469 			 ip6->ip6_dst = rh0->ip6r0_addr[0];
470 			 bcopy((caddr_t)&rh0->ip6r0_addr[1],
471 			       (caddr_t)&rh0->ip6r0_addr[0],
472 			       sizeof(struct in6_addr)*(rh0->ip6r0_segleft - 1)
473 				 );
474 			 rh0->ip6r0_addr[rh0->ip6r0_segleft - 1] = finaldst;
475 			 break;
476 		default:	/* is it possible? */
477 			 error = EINVAL;
478 			 goto bad;
479 		}
480 	}
481 
482 	/* Source address validation */
483 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
484 	    (flags & IPV6_DADOUTPUT) == 0) {
485 		error = EOPNOTSUPP;
486 		ip6stat.ip6s_badscope++;
487 		goto bad;
488 	}
489 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
490 		error = EOPNOTSUPP;
491 		ip6stat.ip6s_badscope++;
492 		goto bad;
493 	}
494 
495 	ip6stat.ip6s_localout++;
496 
497 	/*
498 	 * Route packet.
499 	 */
500 	if (ro == 0) {
501 		ro = &ip6route;
502 		bzero((caddr_t)ro, sizeof(*ro));
503 	}
504 	ro_pmtu = ro;
505 	if (opt && opt->ip6po_rthdr)
506 		ro = &opt->ip6po_route;
507 	dst = (struct sockaddr_in6 *)&ro->ro_dst;
508 	/*
509 	 * If there is a cached route,
510 	 * check that it is to the same destination
511 	 * and is still up. If not, free it and try again.
512 	 */
513 	if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
514 			 dst->sin6_family != AF_INET6 ||
515 			 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_dst))) {
516 		RTFREE(ro->ro_rt);
517 		ro->ro_rt = (struct rtentry *)0;
518 	}
519 	if (ro->ro_rt == 0) {
520 		bzero(dst, sizeof(*dst));
521 		dst->sin6_family = AF_INET6;
522 		dst->sin6_len = sizeof(struct sockaddr_in6);
523 		dst->sin6_addr = ip6->ip6_dst;
524 	}
525 #if defined(IPSEC) || defined(FAST_IPSEC)
526 	if (needipsec && needipsectun) {
527 		struct ipsec_output_state state;
528 
529 		/*
530 		 * All the extension headers will become inaccessible
531 		 * (since they can be encrypted).
532 		 * Don't panic, we need no more updates to extension headers
533 		 * on inner IPv6 packet (since they are now encapsulated).
534 		 *
535 		 * IPv6 [ESP|AH] IPv6 [extension headers] payload
536 		 */
537 		bzero(&exthdrs, sizeof(exthdrs));
538 		exthdrs.ip6e_ip6 = m;
539 
540 		bzero(&state, sizeof(state));
541 		state.m = m;
542 		state.ro = (struct route *)ro;
543 		state.dst = (struct sockaddr *)dst;
544 
545 		error = ipsec6_output_tunnel(&state, sp, flags);
546 
547 		m = state.m;
548 		ro = (struct route_in6 *)state.ro;
549 		dst = (struct sockaddr_in6 *)state.dst;
550 		if (error) {
551 			/* mbuf is already reclaimed in ipsec6_output_tunnel. */
552 			m0 = m = NULL;
553 			m = NULL;
554 			switch (error) {
555 			case EHOSTUNREACH:
556 			case ENETUNREACH:
557 			case EMSGSIZE:
558 			case ENOBUFS:
559 			case ENOMEM:
560 				break;
561 			default:
562 				printf("ip6_output (ipsec): error code %d\n", error);
563 				/* fall through */
564 			case ENOENT:
565 				/* don't show these error codes to the user */
566 				error = 0;
567 				break;
568 			}
569 			goto bad;
570 		}
571 
572 		exthdrs.ip6e_ip6 = m;
573 	}
574 #endif /* IPSEC */
575 
576 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
577 		/* Unicast */
578 
579 #define ifatoia6(ifa)	((struct in6_ifaddr *)(ifa))
580 #define sin6tosa(sin6)	((struct sockaddr *)(sin6))
581 		/* xxx
582 		 * interface selection comes here
583 		 * if an interface is specified from an upper layer,
584 		 * ifp must point it.
585 		 */
586 		if (ro->ro_rt == 0) {
587 			/*
588 			 * non-bsdi always clone routes, if parent is
589 			 * PRF_CLONING.
590 			 */
591 			rtalloc((struct route *)ro);
592 		}
593 		if (ro->ro_rt == 0) {
594 			ip6stat.ip6s_noroute++;
595 			error = EHOSTUNREACH;
596 			/* XXX in6_ifstat_inc(ifp, ifs6_out_discard); */
597 			goto bad;
598 		}
599 		ia = ifatoia6(ro->ro_rt->rt_ifa);
600 		ifp = ro->ro_rt->rt_ifp;
601 		ro->ro_rt->rt_use++;
602 		if (ro->ro_rt->rt_flags & RTF_GATEWAY)
603 			dst = (struct sockaddr_in6 *)ro->ro_rt->rt_gateway;
604 		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
605 
606 		in6_ifstat_inc(ifp, ifs6_out_request);
607 
608 		/*
609 		 * Check if the outgoing interface conflicts with
610 		 * the interface specified by ifi6_ifindex (if specified).
611 		 * Note that loopback interface is always okay.
612 		 * (this may happen when we are sending a packet to one of
613 		 *  our own addresses.)
614 		 */
615 		if (opt && opt->ip6po_pktinfo
616 		 && opt->ip6po_pktinfo->ipi6_ifindex) {
617 			if (!(ifp->if_flags & IFF_LOOPBACK)
618 			 && ifp->if_index != opt->ip6po_pktinfo->ipi6_ifindex) {
619 				ip6stat.ip6s_noroute++;
620 				in6_ifstat_inc(ifp, ifs6_out_discard);
621 				error = EHOSTUNREACH;
622 				goto bad;
623 			}
624 		}
625 
626 		if (opt && opt->ip6po_hlim != -1)
627 			ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
628 	} else {
629 		/* Multicast */
630 		struct	in6_multi *in6m;
631 
632 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
633 
634 		/*
635 		 * See if the caller provided any multicast options
636 		 */
637 		ifp = NULL;
638 		if (im6o != NULL) {
639 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
640 			if (im6o->im6o_multicast_ifp != NULL)
641 				ifp = im6o->im6o_multicast_ifp;
642 		} else
643 			ip6->ip6_hlim = ip6_defmcasthlim;
644 
645 		/*
646 		 * See if the caller provided the outgoing interface
647 		 * as an ancillary data.
648 		 * Boundary check for ifindex is assumed to be already done.
649 		 */
650 		if (opt && opt->ip6po_pktinfo && opt->ip6po_pktinfo->ipi6_ifindex)
651 			ifp = ifindex2ifnet[opt->ip6po_pktinfo->ipi6_ifindex];
652 
653 		/*
654 		 * If the destination is a node-local scope multicast,
655 		 * the packet should be loop-backed only.
656 		 */
657 		if (IN6_IS_ADDR_MC_NODELOCAL(&ip6->ip6_dst)) {
658 			/*
659 			 * If the outgoing interface is already specified,
660 			 * it should be a loopback interface.
661 			 */
662 			if (ifp && (ifp->if_flags & IFF_LOOPBACK) == 0) {
663 				ip6stat.ip6s_badscope++;
664 				error = ENETUNREACH; /* XXX: better error? */
665 				/* XXX correct ifp? */
666 				in6_ifstat_inc(ifp, ifs6_out_discard);
667 				goto bad;
668 			} else {
669 				ifp = &loif[0];
670 			}
671 		}
672 
673 		if (opt && opt->ip6po_hlim != -1)
674 			ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
675 
676 		/*
677 		 * If caller did not provide an interface lookup a
678 		 * default in the routing table.  This is either a
679 		 * default for the speicfied group (i.e. a host
680 		 * route), or a multicast default (a route for the
681 		 * ``net'' ff00::/8).
682 		 */
683 		if (ifp == NULL) {
684 			if (ro->ro_rt == NULL) {
685 				ro->ro_rt =
686 				  rtpurelookup((struct sockaddr *)&ro->ro_dst);
687 			}
688 			if (ro->ro_rt == NULL) {
689 				ip6stat.ip6s_noroute++;
690 				error = EHOSTUNREACH;
691 				/* XXX in6_ifstat_inc(ifp, ifs6_out_discard) */
692 				goto bad;
693 			}
694 			ia = ifatoia6(ro->ro_rt->rt_ifa);
695 			ifp = ro->ro_rt->rt_ifp;
696 			ro->ro_rt->rt_use++;
697 		}
698 
699 		if ((flags & IPV6_FORWARDING) == 0)
700 			in6_ifstat_inc(ifp, ifs6_out_request);
701 		in6_ifstat_inc(ifp, ifs6_out_mcast);
702 
703 		/*
704 		 * Confirm that the outgoing interface supports multicast.
705 		 */
706 		if ((ifp->if_flags & IFF_MULTICAST) == 0) {
707 			ip6stat.ip6s_noroute++;
708 			in6_ifstat_inc(ifp, ifs6_out_discard);
709 			error = ENETUNREACH;
710 			goto bad;
711 		}
712 		IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
713 		if (in6m != NULL &&
714 		   (im6o == NULL || im6o->im6o_multicast_loop)) {
715 			/*
716 			 * If we belong to the destination multicast group
717 			 * on the outgoing interface, and the caller did not
718 			 * forbid loopback, loop back a copy.
719 			 */
720 			ip6_mloopback(ifp, m, dst);
721 		} else {
722 			/*
723 			 * If we are acting as a multicast router, perform
724 			 * multicast forwarding as if the packet had just
725 			 * arrived on the interface to which we are about
726 			 * to send.  The multicast forwarding function
727 			 * recursively calls this function, using the
728 			 * IPV6_FORWARDING flag to prevent infinite recursion.
729 			 *
730 			 * Multicasts that are looped back by ip6_mloopback(),
731 			 * above, will be forwarded by the ip6_input() routine,
732 			 * if necessary.
733 			 */
734 			if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
735 				if (ip6_mforward(ip6, ifp, m) != 0) {
736 					m_freem(m);
737 					goto done;
738 				}
739 			}
740 		}
741 		/*
742 		 * Multicasts with a hoplimit of zero may be looped back,
743 		 * above, but must not be transmitted on a network.
744 		 * Also, multicasts addressed to the loopback interface
745 		 * are not sent -- the above call to ip6_mloopback() will
746 		 * loop back a copy if this host actually belongs to the
747 		 * destination group on the loopback interface.
748 		 */
749 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK)) {
750 			m_freem(m);
751 			goto done;
752 		}
753 	}
754 
755 	/*
756 	 * Fill the outgoing inteface to tell the upper layer
757 	 * to increment per-interface statistics.
758 	 */
759 	if (ifpp)
760 		*ifpp = ifp;
761 
762 	/*
763 	 * Determine path MTU.
764 	 */
765 	if (ro_pmtu != ro) {
766 		/* The first hop and the final destination may differ. */
767 		struct sockaddr_in6 *sin6_fin =
768 			(struct sockaddr_in6 *)&ro_pmtu->ro_dst;
769 
770 		if (ro_pmtu->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
771 				       !IN6_ARE_ADDR_EQUAL(&sin6_fin->sin6_addr,
772 							   &finaldst))) {
773 			RTFREE(ro_pmtu->ro_rt);
774 			ro_pmtu->ro_rt = (struct rtentry *)0;
775 		}
776 		if (ro_pmtu->ro_rt == 0) {
777 			bzero(sin6_fin, sizeof(*sin6_fin));
778 			sin6_fin->sin6_family = AF_INET6;
779 			sin6_fin->sin6_len = sizeof(struct sockaddr_in6);
780 			sin6_fin->sin6_addr = finaldst;
781 
782 			rtalloc((struct route *)ro_pmtu);
783 		}
784 	}
785 	if (ro_pmtu->ro_rt != NULL) {
786 		u_int32_t ifmtu = ND_IFINFO(ifp)->linkmtu;
787 
788 		mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
789 		if (mtu > ifmtu || mtu == 0) {
790 			/*
791 			 * The MTU on the route is larger than the MTU on
792 			 * the interface!  This shouldn't happen, unless the
793 			 * MTU of the interface has been changed after the
794 			 * interface was brought up.  Change the MTU in the
795 			 * route to match the interface MTU (as long as the
796 			 * field isn't locked).
797 			 *
798 			 * if MTU on the route is 0, we need to fix the MTU.
799 			 * this case happens with path MTU discovery timeouts.
800 			 */
801 			 mtu = ifmtu;
802 			 if ((ro_pmtu->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0)
803 				 ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu; /* XXX */
804 		}
805 	} else {
806 		mtu = ND_IFINFO(ifp)->linkmtu;
807 	}
808 
809 	/*
810 	 * advanced API (IPV6_USE_MIN_MTU) overrides mtu setting
811 	 */
812 	if ((flags & IPV6_MINMTU) != 0 && mtu > IPV6_MMTU)
813 		mtu = IPV6_MMTU;
814 
815 	/* Fake scoped addresses */
816 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
817 		/*
818 		 * If source or destination address is a scoped address, and
819 		 * the packet is going to be sent to a loopback interface,
820 		 * we should keep the original interface.
821 		 */
822 
823 		/*
824 		 * XXX: this is a very experimental and temporary solution.
825 		 * We eventually have sockaddr_in6 and use the sin6_scope_id
826 		 * field of the structure here.
827 		 * We rely on the consistency between two scope zone ids
828 		 * of source and destination, which should already be assured.
829 		 * Larger scopes than link will be supported in the future.
830 		 */
831 		origifp = NULL;
832 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
833 			origifp = ifindex2ifnet[ntohs(ip6->ip6_src.s6_addr16[1])];
834 		else if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
835 			origifp = ifindex2ifnet[ntohs(ip6->ip6_dst.s6_addr16[1])];
836 		/*
837 		 * XXX: origifp can be NULL even in those two cases above.
838 		 * For example, if we remove the (only) link-local address
839 		 * from the loopback interface, and try to send a link-local
840 		 * address without link-id information.  Then the source
841 		 * address is ::1, and the destination address is the
842 		 * link-local address with its s6_addr16[1] being zero.
843 		 * What is worse, if the packet goes to the loopback interface
844 		 * by a default rejected route, the null pointer would be
845 		 * passed to looutput, and the kernel would hang.
846 		 * The following last resort would prevent such disaster.
847 		 */
848 		if (origifp == NULL)
849 			origifp = ifp;
850 	}
851 	else
852 		origifp = ifp;
853 	/*
854 	 * clear embedded scope identifiers if necessary.
855 	 * in6_clearscope will touch the addresses only when necessary.
856 	 */
857 	in6_clearscope(&ip6->ip6_src);
858 	in6_clearscope(&ip6->ip6_dst);
859 
860 	/*
861 	 * Check with the firewall...
862 	 */
863 	if (ip6_fw_enable && ip6_fw_chk_ptr) {
864 		u_short port = 0;
865 		m->m_pkthdr.rcvif = NULL;	/* XXX */
866 		/* If ipfw says divert, we have to just drop packet */
867 		if ((*ip6_fw_chk_ptr)(&ip6, ifp, &port, &m)) {
868 			m_freem(m);
869 			goto done;
870 		}
871 		if (!m) {
872 			error = EACCES;
873 			goto done;
874 		}
875 	}
876 
877 	/*
878 	 * If the outgoing packet contains a hop-by-hop options header,
879 	 * it must be examined and processed even by the source node.
880 	 * (RFC 2460, section 4.)
881 	 */
882 	if (exthdrs.ip6e_hbh) {
883 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
884 		u_int32_t dummy1; /* XXX unused */
885 		u_int32_t dummy2; /* XXX unused */
886 
887 #ifdef DIAGNOSTIC
888 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
889 			panic("ip6e_hbh is not continuous");
890 #endif
891 		/*
892 		 *  XXX: if we have to send an ICMPv6 error to the sender,
893 		 *       we need the M_LOOP flag since icmp6_error() expects
894 		 *       the IPv6 and the hop-by-hop options header are
895 		 *       continuous unless the flag is set.
896 		 */
897 		m->m_flags |= M_LOOP;
898 		m->m_pkthdr.rcvif = ifp;
899 		if (ip6_process_hopopts(m,
900 					(u_int8_t *)(hbh + 1),
901 					((hbh->ip6h_len + 1) << 3) -
902 					sizeof(struct ip6_hbh),
903 					&dummy1, &dummy2) < 0) {
904 			/* m was already freed at this point */
905 			error = EINVAL;/* better error? */
906 			goto done;
907 		}
908 		m->m_flags &= ~M_LOOP; /* XXX */
909 		m->m_pkthdr.rcvif = NULL;
910 	}
911 
912 	/*
913 	 * Run through list of hooks for output packets.
914 	 */
915 	if (pfil_has_hooks(&inet6_pfil_hook)) {
916 		error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT);
917 		if (error != 0 || m == NULL)
918 			goto done;
919 		ip6 = mtod(m, struct ip6_hdr *);
920 	}
921 
922 	/*
923 	 * Send the packet to the outgoing interface.
924 	 * If necessary, do IPv6 fragmentation before sending.
925 	 */
926 	tlen = m->m_pkthdr.len;
927 	if (tlen <= mtu
928 #ifdef notyet
929 	    /*
930 	     * On any link that cannot convey a 1280-octet packet in one piece,
931 	     * link-specific fragmentation and reassembly must be provided at
932 	     * a layer below IPv6. [RFC 2460, sec.5]
933 	     * Thus if the interface has ability of link-level fragmentation,
934 	     * we can just send the packet even if the packet size is
935 	     * larger than the link's MTU.
936 	     * XXX: IFF_FRAGMENTABLE (or such) flag has not been defined yet...
937 	     */
938 
939 	    || ifp->if_flags & IFF_FRAGMENTABLE
940 #endif
941 	    )
942 	{
943  		/* Record statistics for this interface address. */
944  		if (ia && !(flags & IPV6_FORWARDING)) {
945  			ia->ia_ifa.if_opackets++;
946  			ia->ia_ifa.if_obytes += m->m_pkthdr.len;
947  		}
948 #ifdef IPSEC
949 		/* clean ipsec history once it goes out of the node */
950 		ipsec_delaux(m);
951 #endif
952 		error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
953 		goto done;
954 	} else if (mtu < IPV6_MMTU) {
955 		/*
956 		 * note that path MTU is never less than IPV6_MMTU
957 		 * (see icmp6_input).
958 		 */
959 		error = EMSGSIZE;
960 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
961 		goto bad;
962 	} else if (ip6->ip6_plen == 0) { /* jumbo payload cannot be fragmented */
963 		error = EMSGSIZE;
964 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
965 		goto bad;
966 	} else {
967 		struct mbuf **mnext, *m_frgpart;
968 		struct ip6_frag *ip6f;
969 		u_int32_t id = htonl(ip6_id++);
970 		u_char nextproto;
971 
972 		/*
973 		 * Too large for the destination or interface;
974 		 * fragment if possible.
975 		 * Must be able to put at least 8 bytes per fragment.
976 		 */
977 		hlen = unfragpartlen;
978 		if (mtu > IPV6_MAXPACKET)
979 			mtu = IPV6_MAXPACKET;
980 
981 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
982 		if (len < 8) {
983 			error = EMSGSIZE;
984 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
985 			goto bad;
986 		}
987 
988 		mnext = &m->m_nextpkt;
989 
990 		/*
991 		 * Change the next header field of the last header in the
992 		 * unfragmentable part.
993 		 */
994 		if (exthdrs.ip6e_rthdr) {
995 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
996 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
997 		} else if (exthdrs.ip6e_dest1) {
998 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
999 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1000 		} else if (exthdrs.ip6e_hbh) {
1001 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1002 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1003 		} else {
1004 			nextproto = ip6->ip6_nxt;
1005 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1006 		}
1007 
1008 		/*
1009 		 * Loop through length of segment after first fragment,
1010 		 * make new header and copy data of each part and link onto
1011 		 * chain.
1012 		 */
1013 		m0 = m;
1014 		for (off = hlen; off < tlen; off += len) {
1015 			MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1016 			if (!m) {
1017 				error = ENOBUFS;
1018 				ip6stat.ip6s_odropped++;
1019 				goto sendorfree;
1020 			}
1021 			m->m_pkthdr.rcvif = NULL;
1022 			m->m_flags = m0->m_flags & M_COPYFLAGS;
1023 			*mnext = m;
1024 			mnext = &m->m_nextpkt;
1025 			m->m_data += max_linkhdr;
1026 			mhip6 = mtod(m, struct ip6_hdr *);
1027 			*mhip6 = *ip6;
1028 			m->m_len = sizeof(*mhip6);
1029  			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1030  			if (error) {
1031 				ip6stat.ip6s_odropped++;
1032 				goto sendorfree;
1033 			}
1034 			ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1035 			if (off + len >= tlen)
1036 				len = tlen - off;
1037 			else
1038 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1039 			mhip6->ip6_plen = htons((u_short)(len + hlen +
1040 							  sizeof(*ip6f) -
1041 							  sizeof(struct ip6_hdr)));
1042 			if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1043 				error = ENOBUFS;
1044 				ip6stat.ip6s_odropped++;
1045 				goto sendorfree;
1046 			}
1047 			m_cat(m, m_frgpart);
1048 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1049 			m->m_pkthdr.rcvif = (struct ifnet *)0;
1050 			ip6f->ip6f_reserved = 0;
1051 			ip6f->ip6f_ident = id;
1052 			ip6f->ip6f_nxt = nextproto;
1053 			ip6stat.ip6s_ofragments++;
1054 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1055 		}
1056 
1057 		in6_ifstat_inc(ifp, ifs6_out_fragok);
1058 	}
1059 
1060 	/*
1061 	 * Remove leading garbages.
1062 	 */
1063 sendorfree:
1064 	m = m0->m_nextpkt;
1065 	m0->m_nextpkt = 0;
1066 	m_freem(m0);
1067 	for (m0 = m; m; m = m0) {
1068 		m0 = m->m_nextpkt;
1069 		m->m_nextpkt = 0;
1070 		if (error == 0) {
1071  			/* Record statistics for this interface address. */
1072  			if (ia) {
1073  				ia->ia_ifa.if_opackets++;
1074  				ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1075  			}
1076 #ifdef IPSEC
1077 			/* clean ipsec history once it goes out of the node */
1078 			ipsec_delaux(m);
1079 #endif
1080 			error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1081 		} else
1082 			m_freem(m);
1083 	}
1084 
1085 	if (error == 0)
1086 		ip6stat.ip6s_fragmented++;
1087 
1088 done:
1089 	if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
1090 		RTFREE(ro->ro_rt);
1091 	} else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
1092 		RTFREE(ro_pmtu->ro_rt);
1093 	}
1094 
1095 #ifdef IPSEC
1096 	if (sp != NULL)
1097 		key_freesp(sp);
1098 #endif /* IPSEC */
1099 #ifdef FAST_IPSEC
1100 	if (sp != NULL)
1101 		KEY_FREESP(&sp);
1102 #endif /* FAST_IPSEC */
1103 
1104 	return(error);
1105 
1106 freehdrs:
1107 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
1108 	m_freem(exthdrs.ip6e_dest1);
1109 	m_freem(exthdrs.ip6e_rthdr);
1110 	m_freem(exthdrs.ip6e_dest2);
1111 	/* fall through */
1112 bad:
1113 	m_freem(m);
1114 	goto done;
1115 }
1116 
1117 static int
1118 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1119 {
1120 	struct mbuf *m;
1121 
1122 	if (hlen > MCLBYTES)
1123 		return(ENOBUFS); /* XXX */
1124 
1125 	MGET(m, MB_DONTWAIT, MT_DATA);
1126 	if (!m)
1127 		return(ENOBUFS);
1128 
1129 	if (hlen > MLEN) {
1130 		MCLGET(m, MB_DONTWAIT);
1131 		if ((m->m_flags & M_EXT) == 0) {
1132 			m_free(m);
1133 			return(ENOBUFS);
1134 		}
1135 	}
1136 	m->m_len = hlen;
1137 	if (hdr)
1138 		bcopy(hdr, mtod(m, caddr_t), hlen);
1139 
1140 	*mp = m;
1141 	return(0);
1142 }
1143 
1144 /*
1145  * Insert jumbo payload option.
1146  */
1147 static int
1148 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1149 {
1150 	struct mbuf *mopt;
1151 	u_char *optbuf;
1152 	u_int32_t v;
1153 
1154 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1155 
1156 	/*
1157 	 * If there is no hop-by-hop options header, allocate new one.
1158 	 * If there is one but it doesn't have enough space to store the
1159 	 * jumbo payload option, allocate a cluster to store the whole options.
1160 	 * Otherwise, use it to store the options.
1161 	 */
1162 	if (exthdrs->ip6e_hbh == 0) {
1163 		MGET(mopt, MB_DONTWAIT, MT_DATA);
1164 		if (mopt == 0)
1165 			return(ENOBUFS);
1166 		mopt->m_len = JUMBOOPTLEN;
1167 		optbuf = mtod(mopt, u_char *);
1168 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1169 		exthdrs->ip6e_hbh = mopt;
1170 	} else {
1171 		struct ip6_hbh *hbh;
1172 
1173 		mopt = exthdrs->ip6e_hbh;
1174 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1175 			/*
1176 			 * XXX assumption:
1177 			 * - exthdrs->ip6e_hbh is not referenced from places
1178 			 *   other than exthdrs.
1179 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1180 			 */
1181 			int oldoptlen = mopt->m_len;
1182 			struct mbuf *n;
1183 
1184 			/*
1185 			 * XXX: give up if the whole (new) hbh header does
1186 			 * not fit even in an mbuf cluster.
1187 			 */
1188 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1189 				return(ENOBUFS);
1190 
1191 			/*
1192 			 * As a consequence, we must always prepare a cluster
1193 			 * at this point.
1194 			 */
1195 			MGET(n, MB_DONTWAIT, MT_DATA);
1196 			if (n) {
1197 				MCLGET(n, MB_DONTWAIT);
1198 				if ((n->m_flags & M_EXT) == 0) {
1199 					m_freem(n);
1200 					n = NULL;
1201 				}
1202 			}
1203 			if (!n)
1204 				return(ENOBUFS);
1205 			n->m_len = oldoptlen + JUMBOOPTLEN;
1206 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1207 			      oldoptlen);
1208 			optbuf = mtod(n, caddr_t) + oldoptlen;
1209 			m_freem(mopt);
1210 			mopt = exthdrs->ip6e_hbh = n;
1211 		} else {
1212 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1213 			mopt->m_len += JUMBOOPTLEN;
1214 		}
1215 		optbuf[0] = IP6OPT_PADN;
1216 		optbuf[1] = 1;
1217 
1218 		/*
1219 		 * Adjust the header length according to the pad and
1220 		 * the jumbo payload option.
1221 		 */
1222 		hbh = mtod(mopt, struct ip6_hbh *);
1223 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1224 	}
1225 
1226 	/* fill in the option. */
1227 	optbuf[2] = IP6OPT_JUMBO;
1228 	optbuf[3] = 4;
1229 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1230 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1231 
1232 	/* finally, adjust the packet header length */
1233 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1234 
1235 	return(0);
1236 #undef JUMBOOPTLEN
1237 }
1238 
1239 /*
1240  * Insert fragment header and copy unfragmentable header portions.
1241  */
1242 static int
1243 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1244 		  struct ip6_frag **frghdrp)
1245 {
1246 	struct mbuf *n, *mlast;
1247 
1248 	if (hlen > sizeof(struct ip6_hdr)) {
1249 		n = m_copym(m0, sizeof(struct ip6_hdr),
1250 			    hlen - sizeof(struct ip6_hdr), MB_DONTWAIT);
1251 		if (n == 0)
1252 			return(ENOBUFS);
1253 		m->m_next = n;
1254 	} else
1255 		n = m;
1256 
1257 	/* Search for the last mbuf of unfragmentable part. */
1258 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1259 		;
1260 
1261 	if ((mlast->m_flags & M_EXT) == 0 &&
1262 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1263 		/* use the trailing space of the last mbuf for the fragment hdr */
1264 		*frghdrp =
1265 			(struct ip6_frag *)(mtod(mlast, caddr_t) + mlast->m_len);
1266 		mlast->m_len += sizeof(struct ip6_frag);
1267 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1268 	} else {
1269 		/* allocate a new mbuf for the fragment header */
1270 		struct mbuf *mfrg;
1271 
1272 		MGET(mfrg, MB_DONTWAIT, MT_DATA);
1273 		if (mfrg == 0)
1274 			return(ENOBUFS);
1275 		mfrg->m_len = sizeof(struct ip6_frag);
1276 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1277 		mlast->m_next = mfrg;
1278 	}
1279 
1280 	return(0);
1281 }
1282 
1283 /*
1284  * IP6 socket option processing.
1285  */
1286 int
1287 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1288 {
1289 	int privileged;
1290 	struct inpcb *in6p = so->so_pcb;
1291 	int error, optval;
1292 	int level, op, optname;
1293 	int optlen;
1294 	struct thread *td;
1295 
1296 	if (sopt) {
1297 		level = sopt->sopt_level;
1298 		op = sopt->sopt_dir;
1299 		optname = sopt->sopt_name;
1300 		optlen = sopt->sopt_valsize;
1301 		td = sopt->sopt_td;
1302 	} else {
1303 		panic("ip6_ctloutput: arg soopt is NULL");
1304 		/* NOT REACHED */
1305 		td = NULL;
1306 	}
1307 	error = optval = 0;
1308 
1309 	privileged = (td == NULL || suser(td)) ? 0 : 1;
1310 
1311 	if (level == IPPROTO_IPV6) {
1312 		switch (op) {
1313 
1314 		case SOPT_SET:
1315 			switch (optname) {
1316 			case IPV6_PKTOPTIONS:
1317 			{
1318 				struct mbuf *m;
1319 
1320 				error = soopt_getm(sopt, &m); /* XXX */
1321 				if (error != NULL)
1322 					break;
1323 				error = soopt_mcopyin(sopt, m); /* XXX */
1324 				if (error != NULL)
1325 					break;
1326 				error = ip6_pcbopts(&in6p->in6p_outputopts,
1327 						    m, so, sopt);
1328 				m_freem(m); /* XXX */
1329 				break;
1330 			}
1331 
1332 			/*
1333 			 * Use of some Hop-by-Hop options or some
1334 			 * Destination options, might require special
1335 			 * privilege.  That is, normal applications
1336 			 * (without special privilege) might be forbidden
1337 			 * from setting certain options in outgoing packets,
1338 			 * and might never see certain options in received
1339 			 * packets. [RFC 2292 Section 6]
1340 			 * KAME specific note:
1341 			 *  KAME prevents non-privileged users from sending or
1342 			 *  receiving ANY hbh/dst options in order to avoid
1343 			 *  overhead of parsing options in the kernel.
1344 			 */
1345 			case IPV6_UNICAST_HOPS:
1346 			case IPV6_CHECKSUM:
1347 			case IPV6_FAITH:
1348 
1349 			case IPV6_V6ONLY:
1350 				if (optlen != sizeof(int)) {
1351 					error = EINVAL;
1352 					break;
1353 				}
1354 				error = sooptcopyin(sopt, &optval,
1355 					sizeof optval, sizeof optval);
1356 				if (error)
1357 					break;
1358 				switch (optname) {
1359 
1360 				case IPV6_UNICAST_HOPS:
1361 					if (optval < -1 || optval >= 256)
1362 						error = EINVAL;
1363 					else {
1364 						/* -1 = kernel default */
1365 						in6p->in6p_hops = optval;
1366 
1367 						if ((in6p->in6p_vflag &
1368 						     INP_IPV4) != 0)
1369 							in6p->inp_ip_ttl = optval;
1370 					}
1371 					break;
1372 #define OPTSET(bit) \
1373 do { \
1374 	if (optval) \
1375 		in6p->in6p_flags |= (bit); \
1376 	else \
1377 		in6p->in6p_flags &= ~(bit); \
1378 } while (0)
1379 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
1380 
1381 				case IPV6_CHECKSUM:
1382 					in6p->in6p_cksum = optval;
1383 					break;
1384 
1385 				case IPV6_FAITH:
1386 					OPTSET(IN6P_FAITH);
1387 					break;
1388 
1389 				case IPV6_V6ONLY:
1390 					/*
1391 					 * make setsockopt(IPV6_V6ONLY)
1392 					 * available only prior to bind(2).
1393 					 * see ipng mailing list, Jun 22 2001.
1394 					 */
1395 					if (in6p->in6p_lport ||
1396 					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr))
1397 					{
1398 						error = EINVAL;
1399 						break;
1400 					}
1401 					OPTSET(IN6P_IPV6_V6ONLY);
1402 					if (optval)
1403 						in6p->in6p_vflag &= ~INP_IPV4;
1404 					else
1405 						in6p->in6p_vflag |= INP_IPV4;
1406 					break;
1407 				}
1408 				break;
1409 
1410 			case IPV6_PKTINFO:
1411 			case IPV6_HOPLIMIT:
1412 			case IPV6_HOPOPTS:
1413 			case IPV6_DSTOPTS:
1414 			case IPV6_RTHDR:
1415 				/* RFC 2292 */
1416 				if (optlen != sizeof(int)) {
1417 					error = EINVAL;
1418 					break;
1419 				}
1420 				error = sooptcopyin(sopt, &optval,
1421 					sizeof optval, sizeof optval);
1422 				if (error)
1423 					break;
1424 				switch (optname) {
1425 				case IPV6_PKTINFO:
1426 					OPTSET(IN6P_PKTINFO);
1427 					break;
1428 				case IPV6_HOPLIMIT:
1429 					OPTSET(IN6P_HOPLIMIT);
1430 					break;
1431 				case IPV6_HOPOPTS:
1432 					/*
1433 					 * Check super-user privilege.
1434 					 * See comments for IPV6_RECVHOPOPTS.
1435 					 */
1436 					if (!privileged)
1437 						return(EPERM);
1438 					OPTSET(IN6P_HOPOPTS);
1439 					break;
1440 				case IPV6_DSTOPTS:
1441 					if (!privileged)
1442 						return(EPERM);
1443 					OPTSET(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1444 					break;
1445 				case IPV6_RTHDR:
1446 					OPTSET(IN6P_RTHDR);
1447 					break;
1448 				}
1449 				break;
1450 #undef OPTSET
1451 
1452 			case IPV6_MULTICAST_IF:
1453 			case IPV6_MULTICAST_HOPS:
1454 			case IPV6_MULTICAST_LOOP:
1455 			case IPV6_JOIN_GROUP:
1456 			case IPV6_LEAVE_GROUP:
1457 			    {
1458 				struct mbuf *m;
1459 				if (sopt->sopt_valsize > MLEN) {
1460 					error = EMSGSIZE;
1461 					break;
1462 				}
1463 				/* XXX */
1464 				MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER);
1465 				if (m == 0) {
1466 					error = ENOBUFS;
1467 					break;
1468 				}
1469 				m->m_len = sopt->sopt_valsize;
1470 				error = sooptcopyin(sopt, mtod(m, char *),
1471 						    m->m_len, m->m_len);
1472 				error =	ip6_setmoptions(sopt->sopt_name,
1473 							&in6p->in6p_moptions,
1474 							m);
1475 				(void)m_free(m);
1476 			    }
1477 				break;
1478 
1479 			case IPV6_PORTRANGE:
1480 				error = sooptcopyin(sopt, &optval,
1481 				    sizeof optval, sizeof optval);
1482 				if (error)
1483 					break;
1484 
1485 				switch (optval) {
1486 				case IPV6_PORTRANGE_DEFAULT:
1487 					in6p->in6p_flags &= ~(IN6P_LOWPORT);
1488 					in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1489 					break;
1490 
1491 				case IPV6_PORTRANGE_HIGH:
1492 					in6p->in6p_flags &= ~(IN6P_LOWPORT);
1493 					in6p->in6p_flags |= IN6P_HIGHPORT;
1494 					break;
1495 
1496 				case IPV6_PORTRANGE_LOW:
1497 					in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1498 					in6p->in6p_flags |= IN6P_LOWPORT;
1499 					break;
1500 
1501 				default:
1502 					error = EINVAL;
1503 					break;
1504 				}
1505 				break;
1506 
1507 #if defined(IPSEC) || defined(FAST_IPSEC)
1508 			case IPV6_IPSEC_POLICY:
1509 			    {
1510 				caddr_t req = NULL;
1511 				size_t len = 0;
1512 				struct mbuf *m;
1513 
1514 				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1515 					break;
1516 				if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1517 					break;
1518 				if (m) {
1519 					req = mtod(m, caddr_t);
1520 					len = m->m_len;
1521 				}
1522 				error = ipsec6_set_policy(in6p, optname, req,
1523 							  len, privileged);
1524 				m_freem(m);
1525 			    }
1526 				break;
1527 #endif /* KAME IPSEC */
1528 
1529 			case IPV6_FW_ADD:
1530 			case IPV6_FW_DEL:
1531 			case IPV6_FW_FLUSH:
1532 			case IPV6_FW_ZERO:
1533 			    {
1534 				struct mbuf *m;
1535 				struct mbuf **mp = &m;
1536 
1537 				if (ip6_fw_ctl_ptr == NULL)
1538 					return EINVAL;
1539 				/* XXX */
1540 				if ((error = soopt_getm(sopt, &m)) != 0)
1541 					break;
1542 				/* XXX */
1543 				if ((error = soopt_mcopyin(sopt, m)) != 0)
1544 					break;
1545 				error = (*ip6_fw_ctl_ptr)(optname, mp);
1546 				m = *mp;
1547 			    }
1548 				break;
1549 
1550 			default:
1551 				error = ENOPROTOOPT;
1552 				break;
1553 			}
1554 			break;
1555 
1556 		case SOPT_GET:
1557 			switch (optname) {
1558 
1559 			case IPV6_PKTOPTIONS:
1560 				if (in6p->in6p_options) {
1561 					struct mbuf *m;
1562 					m = m_copym(in6p->in6p_options,
1563 					    0, M_COPYALL, MB_WAIT);
1564 					error = soopt_mcopyout(sopt, m);
1565 					if (error == 0)
1566 						m_freem(m);
1567 				} else
1568 					sopt->sopt_valsize = 0;
1569 				break;
1570 
1571 			case IPV6_UNICAST_HOPS:
1572 			case IPV6_CHECKSUM:
1573 
1574 			case IPV6_FAITH:
1575 			case IPV6_V6ONLY:
1576 			case IPV6_PORTRANGE:
1577 				switch (optname) {
1578 
1579 				case IPV6_UNICAST_HOPS:
1580 					optval = in6p->in6p_hops;
1581 					break;
1582 
1583 				case IPV6_CHECKSUM:
1584 					optval = in6p->in6p_cksum;
1585 					break;
1586 
1587 				case IPV6_FAITH:
1588 					optval = OPTBIT(IN6P_FAITH);
1589 					break;
1590 
1591 				case IPV6_V6ONLY:
1592 					optval = OPTBIT(IN6P_IPV6_V6ONLY);
1593 					break;
1594 
1595 				case IPV6_PORTRANGE:
1596 				    {
1597 					int flags;
1598 					flags = in6p->in6p_flags;
1599 					if (flags & IN6P_HIGHPORT)
1600 						optval = IPV6_PORTRANGE_HIGH;
1601 					else if (flags & IN6P_LOWPORT)
1602 						optval = IPV6_PORTRANGE_LOW;
1603 					else
1604 						optval = 0;
1605 					break;
1606 				    }
1607 				}
1608 				error = sooptcopyout(sopt, &optval,
1609 					sizeof optval);
1610 				break;
1611 
1612 			case IPV6_PKTINFO:
1613 			case IPV6_HOPLIMIT:
1614 			case IPV6_HOPOPTS:
1615 			case IPV6_RTHDR:
1616 			case IPV6_DSTOPTS:
1617 				if (optname == IPV6_HOPOPTS ||
1618 				    optname == IPV6_DSTOPTS ||
1619 				    !privileged)
1620 					return(EPERM);
1621 				switch (optname) {
1622 				case IPV6_PKTINFO:
1623 					optval = OPTBIT(IN6P_PKTINFO);
1624 					break;
1625 				case IPV6_HOPLIMIT:
1626 					optval = OPTBIT(IN6P_HOPLIMIT);
1627 					break;
1628 				case IPV6_HOPOPTS:
1629 					if (!privileged)
1630 						return(EPERM);
1631 					optval = OPTBIT(IN6P_HOPOPTS);
1632 					break;
1633 				case IPV6_RTHDR:
1634 					optval = OPTBIT(IN6P_RTHDR);
1635 					break;
1636 				case IPV6_DSTOPTS:
1637 					if (!privileged)
1638 						return(EPERM);
1639 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1640 					break;
1641 				}
1642 				error = sooptcopyout(sopt, &optval,
1643 					sizeof optval);
1644 				break;
1645 
1646 			case IPV6_MULTICAST_IF:
1647 			case IPV6_MULTICAST_HOPS:
1648 			case IPV6_MULTICAST_LOOP:
1649 			case IPV6_JOIN_GROUP:
1650 			case IPV6_LEAVE_GROUP:
1651 			    {
1652 				struct mbuf *m;
1653 				error = ip6_getmoptions(sopt->sopt_name,
1654 						in6p->in6p_moptions, &m);
1655 				if (error == 0)
1656 					error = sooptcopyout(sopt,
1657 						mtod(m, char *), m->m_len);
1658 				m_freem(m);
1659 			    }
1660 				break;
1661 
1662 #if defined(IPSEC) || defined(FAST_IPSEC)
1663 			case IPV6_IPSEC_POLICY:
1664 			  {
1665 				caddr_t req = NULL;
1666 				size_t len = 0;
1667 				struct mbuf *m = NULL;
1668 				struct mbuf **mp = &m;
1669 
1670 				error = soopt_getm(sopt, &m); /* XXX */
1671 				if (error != NULL)
1672 					break;
1673 				error = soopt_mcopyin(sopt, m); /* XXX */
1674 				if (error != NULL)
1675 					break;
1676 				if (m) {
1677 					req = mtod(m, caddr_t);
1678 					len = m->m_len;
1679 				}
1680 				error = ipsec6_get_policy(in6p, req, len, mp);
1681 				if (error == 0)
1682 					error = soopt_mcopyout(sopt, m); /*XXX*/
1683 				if (error == 0 && m)
1684 					m_freem(m);
1685 				break;
1686 			  }
1687 #endif /* KAME IPSEC */
1688 
1689 			case IPV6_FW_GET:
1690 			  {
1691 				struct mbuf *m;
1692 				struct mbuf **mp = &m;
1693 
1694 				if (ip6_fw_ctl_ptr == NULL)
1695 				{
1696 					return EINVAL;
1697 				}
1698 				error = (*ip6_fw_ctl_ptr)(optname, mp);
1699 				if (error == 0)
1700 					error = soopt_mcopyout(sopt, m); /* XXX */
1701 				if (error == 0 && m)
1702 					m_freem(m);
1703 			  }
1704 				break;
1705 
1706 			default:
1707 				error = ENOPROTOOPT;
1708 				break;
1709 			}
1710 			break;
1711 		}
1712 	} else {
1713 		error = EINVAL;
1714 	}
1715 	return(error);
1716 }
1717 
1718 /*
1719  * Set up IP6 options in pcb for insertion in output packets or
1720  * specifying behavior of outgoing packets.
1721  */
1722 static int
1723 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m, struct socket *so,
1724 	    struct sockopt *sopt)
1725 {
1726 	struct ip6_pktopts *opt = *pktopt;
1727 	int error = 0;
1728 	struct thread *td = sopt->sopt_td;
1729 	int priv = 0;
1730 
1731 	/* turn off any old options. */
1732 	if (opt) {
1733 #ifdef DIAGNOSTIC
1734 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
1735 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
1736 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
1737 			printf("ip6_pcbopts: all specified options are cleared.\n");
1738 #endif
1739 		ip6_clearpktopts(opt, 1, -1);
1740 	} else
1741 		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
1742 	*pktopt = NULL;
1743 
1744 	if (!m || m->m_len == 0) {
1745 		/*
1746 		 * Only turning off any previous options, regardless of
1747 		 * whether the opt is just created or given.
1748 		 */
1749 		free(opt, M_IP6OPT);
1750 		return(0);
1751 	}
1752 
1753 	/*  set options specified by user. */
1754 	if (suser(td) == 0)
1755 		priv = 1;
1756 	if ((error = ip6_setpktoptions(m, opt, priv, 1)) != 0) {
1757 		ip6_clearpktopts(opt, 1, -1); /* XXX: discard all options */
1758 		free(opt, M_IP6OPT);
1759 		return(error);
1760 	}
1761 	*pktopt = opt;
1762 	return(0);
1763 }
1764 
1765 /*
1766  * initialize ip6_pktopts.  beware that there are non-zero default values in
1767  * the struct.
1768  */
1769 void
1770 init_ip6pktopts(struct ip6_pktopts *opt)
1771 {
1772 
1773 	bzero(opt, sizeof(*opt));
1774 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
1775 }
1776 
1777 void
1778 ip6_clearpktopts(struct ip6_pktopts *pktopt, int needfree, int optname)
1779 {
1780 	if (pktopt == NULL)
1781 		return;
1782 
1783 	if (optname == -1) {
1784 		if (needfree && pktopt->ip6po_pktinfo)
1785 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
1786 		pktopt->ip6po_pktinfo = NULL;
1787 	}
1788 	if (optname == -1)
1789 		pktopt->ip6po_hlim = -1;
1790 	if (optname == -1) {
1791 		if (needfree && pktopt->ip6po_nexthop)
1792 			free(pktopt->ip6po_nexthop, M_IP6OPT);
1793 		pktopt->ip6po_nexthop = NULL;
1794 	}
1795 	if (optname == -1) {
1796 		if (needfree && pktopt->ip6po_hbh)
1797 			free(pktopt->ip6po_hbh, M_IP6OPT);
1798 		pktopt->ip6po_hbh = NULL;
1799 	}
1800 	if (optname == -1) {
1801 		if (needfree && pktopt->ip6po_dest1)
1802 			free(pktopt->ip6po_dest1, M_IP6OPT);
1803 		pktopt->ip6po_dest1 = NULL;
1804 	}
1805 	if (optname == -1) {
1806 		if (needfree && pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
1807 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
1808 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
1809 		if (pktopt->ip6po_route.ro_rt) {
1810 			RTFREE(pktopt->ip6po_route.ro_rt);
1811 			pktopt->ip6po_route.ro_rt = NULL;
1812 		}
1813 	}
1814 	if (optname == -1) {
1815 		if (needfree && pktopt->ip6po_dest2)
1816 			free(pktopt->ip6po_dest2, M_IP6OPT);
1817 		pktopt->ip6po_dest2 = NULL;
1818 	}
1819 }
1820 
1821 #define PKTOPT_EXTHDRCPY(type) \
1822 do {\
1823 	if (src->type) {\
1824 		int hlen =\
1825 			(((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
1826 		dst->type = malloc(hlen, M_IP6OPT, canwait);\
1827 		if (dst->type == NULL && canwait == M_NOWAIT)\
1828 			goto bad;\
1829 		bcopy(src->type, dst->type, hlen);\
1830 	}\
1831 } while (0)
1832 
1833 struct ip6_pktopts *
1834 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
1835 {
1836 	struct ip6_pktopts *dst;
1837 
1838 	if (src == NULL) {
1839 		printf("ip6_clearpktopts: invalid argument\n");
1840 		return(NULL);
1841 	}
1842 
1843 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
1844 	if (dst == NULL && canwait == M_NOWAIT)
1845 		return (NULL);
1846 	bzero(dst, sizeof(*dst));
1847 
1848 	dst->ip6po_hlim = src->ip6po_hlim;
1849 	if (src->ip6po_pktinfo) {
1850 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
1851 					    M_IP6OPT, canwait);
1852 		if (dst->ip6po_pktinfo == NULL && canwait == M_NOWAIT)
1853 			goto bad;
1854 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
1855 	}
1856 	if (src->ip6po_nexthop) {
1857 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
1858 					    M_IP6OPT, canwait);
1859 		if (dst->ip6po_nexthop == NULL && canwait == M_NOWAIT)
1860 			goto bad;
1861 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
1862 		      src->ip6po_nexthop->sa_len);
1863 	}
1864 	PKTOPT_EXTHDRCPY(ip6po_hbh);
1865 	PKTOPT_EXTHDRCPY(ip6po_dest1);
1866 	PKTOPT_EXTHDRCPY(ip6po_dest2);
1867 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
1868 	return(dst);
1869 
1870   bad:
1871 	if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
1872 	if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
1873 	if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
1874 	if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
1875 	if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
1876 	if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
1877 	free(dst, M_IP6OPT);
1878 	return(NULL);
1879 }
1880 #undef PKTOPT_EXTHDRCPY
1881 
1882 void
1883 ip6_freepcbopts(struct ip6_pktopts *pktopt)
1884 {
1885 	if (pktopt == NULL)
1886 		return;
1887 
1888 	ip6_clearpktopts(pktopt, 1, -1);
1889 
1890 	free(pktopt, M_IP6OPT);
1891 }
1892 
1893 /*
1894  * Set the IP6 multicast options in response to user setsockopt().
1895  */
1896 static int
1897 ip6_setmoptions(int optname, struct ip6_moptions **im6op, struct mbuf *m)
1898 {
1899 	int error = 0;
1900 	u_int loop, ifindex;
1901 	struct ipv6_mreq *mreq;
1902 	struct ifnet *ifp;
1903 	struct ip6_moptions *im6o = *im6op;
1904 	struct route_in6 ro;
1905 	struct sockaddr_in6 *dst;
1906 	struct in6_multi_mship *imm;
1907 	struct thread *td = curthread;	/* XXX */
1908 
1909 	if (im6o == NULL) {
1910 		/*
1911 		 * No multicast option buffer attached to the pcb;
1912 		 * allocate one and initialize to default values.
1913 		 */
1914 		im6o = (struct ip6_moptions *)
1915 			malloc(sizeof(*im6o), M_IPMOPTS, M_WAITOK);
1916 
1917 		if (im6o == NULL)
1918 			return(ENOBUFS);
1919 		*im6op = im6o;
1920 		im6o->im6o_multicast_ifp = NULL;
1921 		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
1922 		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
1923 		LIST_INIT(&im6o->im6o_memberships);
1924 	}
1925 
1926 	switch (optname) {
1927 
1928 	case IPV6_MULTICAST_IF:
1929 		/*
1930 		 * Select the interface for outgoing multicast packets.
1931 		 */
1932 		if (m == NULL || m->m_len != sizeof(u_int)) {
1933 			error = EINVAL;
1934 			break;
1935 		}
1936 		bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
1937 		if (ifindex < 0 || if_index < ifindex) {
1938 			error = ENXIO;	/* XXX EINVAL? */
1939 			break;
1940 		}
1941 		ifp = ifindex2ifnet[ifindex];
1942 		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
1943 			error = EADDRNOTAVAIL;
1944 			break;
1945 		}
1946 		im6o->im6o_multicast_ifp = ifp;
1947 		break;
1948 
1949 	case IPV6_MULTICAST_HOPS:
1950 	    {
1951 		/*
1952 		 * Set the IP6 hoplimit for outgoing multicast packets.
1953 		 */
1954 		int optval;
1955 		if (m == NULL || m->m_len != sizeof(int)) {
1956 			error = EINVAL;
1957 			break;
1958 		}
1959 		bcopy(mtod(m, u_int *), &optval, sizeof(optval));
1960 		if (optval < -1 || optval >= 256)
1961 			error = EINVAL;
1962 		else if (optval == -1)
1963 			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
1964 		else
1965 			im6o->im6o_multicast_hlim = optval;
1966 		break;
1967 	    }
1968 
1969 	case IPV6_MULTICAST_LOOP:
1970 		/*
1971 		 * Set the loopback flag for outgoing multicast packets.
1972 		 * Must be zero or one.
1973 		 */
1974 		if (m == NULL || m->m_len != sizeof(u_int)) {
1975 			error = EINVAL;
1976 			break;
1977 		}
1978 		bcopy(mtod(m, u_int *), &loop, sizeof(loop));
1979 		if (loop > 1) {
1980 			error = EINVAL;
1981 			break;
1982 		}
1983 		im6o->im6o_multicast_loop = loop;
1984 		break;
1985 
1986 	case IPV6_JOIN_GROUP:
1987 		/*
1988 		 * Add a multicast group membership.
1989 		 * Group must be a valid IP6 multicast address.
1990 		 */
1991 		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
1992 			error = EINVAL;
1993 			break;
1994 		}
1995 		mreq = mtod(m, struct ipv6_mreq *);
1996 		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
1997 			/*
1998 			 * We use the unspecified address to specify to accept
1999 			 * all multicast addresses. Only super user is allowed
2000 			 * to do this.
2001 			 */
2002 			if (suser(td))
2003 			{
2004 				error = EACCES;
2005 				break;
2006 			}
2007 		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2008 			error = EINVAL;
2009 			break;
2010 		}
2011 
2012 		/*
2013 		 * If the interface is specified, validate it.
2014 		 */
2015 		if (mreq->ipv6mr_interface < 0
2016 		 || if_index < mreq->ipv6mr_interface) {
2017 			error = ENXIO;	/* XXX EINVAL? */
2018 			break;
2019 		}
2020 		/*
2021 		 * If no interface was explicitly specified, choose an
2022 		 * appropriate one according to the given multicast address.
2023 		 */
2024 		if (mreq->ipv6mr_interface == 0) {
2025 			/*
2026 			 * If the multicast address is in node-local scope,
2027 			 * the interface should be a loopback interface.
2028 			 * Otherwise, look up the routing table for the
2029 			 * address, and choose the outgoing interface.
2030 			 *   XXX: is it a good approach?
2031 			 */
2032 			if (IN6_IS_ADDR_MC_NODELOCAL(&mreq->ipv6mr_multiaddr)) {
2033 				ifp = &loif[0];
2034 			} else {
2035 				ro.ro_rt = NULL;
2036 				dst = (struct sockaddr_in6 *)&ro.ro_dst;
2037 				bzero(dst, sizeof(*dst));
2038 				dst->sin6_len = sizeof(struct sockaddr_in6);
2039 				dst->sin6_family = AF_INET6;
2040 				dst->sin6_addr = mreq->ipv6mr_multiaddr;
2041 				rtalloc((struct route *)&ro);
2042 				if (ro.ro_rt == NULL) {
2043 					error = EADDRNOTAVAIL;
2044 					break;
2045 				}
2046 				ifp = ro.ro_rt->rt_ifp;
2047 				rtfree(ro.ro_rt);
2048 			}
2049 		} else
2050 			ifp = ifindex2ifnet[mreq->ipv6mr_interface];
2051 
2052 		/*
2053 		 * See if we found an interface, and confirm that it
2054 		 * supports multicast
2055 		 */
2056 		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
2057 			error = EADDRNOTAVAIL;
2058 			break;
2059 		}
2060 		/*
2061 		 * Put interface index into the multicast address,
2062 		 * if the address has link-local scope.
2063 		 */
2064 		if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
2065 			mreq->ipv6mr_multiaddr.s6_addr16[1]
2066 				= htons(mreq->ipv6mr_interface);
2067 		}
2068 		/*
2069 		 * See if the membership already exists.
2070 		 */
2071 		for (imm = im6o->im6o_memberships.lh_first;
2072 		     imm != NULL; imm = imm->i6mm_chain.le_next)
2073 			if (imm->i6mm_maddr->in6m_ifp == ifp &&
2074 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2075 					       &mreq->ipv6mr_multiaddr))
2076 				break;
2077 		if (imm != NULL) {
2078 			error = EADDRINUSE;
2079 			break;
2080 		}
2081 		/*
2082 		 * Everything looks good; add a new record to the multicast
2083 		 * address list for the given interface.
2084 		 */
2085 		imm = malloc(sizeof(*imm), M_IPMADDR, M_WAITOK);
2086 		if (imm == NULL) {
2087 			error = ENOBUFS;
2088 			break;
2089 		}
2090 		if ((imm->i6mm_maddr =
2091 		     in6_addmulti(&mreq->ipv6mr_multiaddr, ifp, &error)) == NULL) {
2092 			free(imm, M_IPMADDR);
2093 			break;
2094 		}
2095 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
2096 		break;
2097 
2098 	case IPV6_LEAVE_GROUP:
2099 		/*
2100 		 * Drop a multicast group membership.
2101 		 * Group must be a valid IP6 multicast address.
2102 		 */
2103 		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2104 			error = EINVAL;
2105 			break;
2106 		}
2107 		mreq = mtod(m, struct ipv6_mreq *);
2108 		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2109 			if (suser(td)) {
2110 				error = EACCES;
2111 				break;
2112 			}
2113 		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2114 			error = EINVAL;
2115 			break;
2116 		}
2117 		/*
2118 		 * If an interface address was specified, get a pointer
2119 		 * to its ifnet structure.
2120 		 */
2121 		if (mreq->ipv6mr_interface < 0
2122 		 || if_index < mreq->ipv6mr_interface) {
2123 			error = ENXIO;	/* XXX EINVAL? */
2124 			break;
2125 		}
2126 		ifp = ifindex2ifnet[mreq->ipv6mr_interface];
2127 		/*
2128 		 * Put interface index into the multicast address,
2129 		 * if the address has link-local scope.
2130 		 */
2131 		if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
2132 			mreq->ipv6mr_multiaddr.s6_addr16[1]
2133 				= htons(mreq->ipv6mr_interface);
2134 		}
2135 		/*
2136 		 * Find the membership in the membership list.
2137 		 */
2138 		for (imm = im6o->im6o_memberships.lh_first;
2139 		     imm != NULL; imm = imm->i6mm_chain.le_next) {
2140 			if ((ifp == NULL ||
2141 			     imm->i6mm_maddr->in6m_ifp == ifp) &&
2142 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2143 					       &mreq->ipv6mr_multiaddr))
2144 				break;
2145 		}
2146 		if (imm == NULL) {
2147 			/* Unable to resolve interface */
2148 			error = EADDRNOTAVAIL;
2149 			break;
2150 		}
2151 		/*
2152 		 * Give up the multicast address record to which the
2153 		 * membership points.
2154 		 */
2155 		LIST_REMOVE(imm, i6mm_chain);
2156 		in6_delmulti(imm->i6mm_maddr);
2157 		free(imm, M_IPMADDR);
2158 		break;
2159 
2160 	default:
2161 		error = EOPNOTSUPP;
2162 		break;
2163 	}
2164 
2165 	/*
2166 	 * If all options have default values, no need to keep the mbuf.
2167 	 */
2168 	if (im6o->im6o_multicast_ifp == NULL &&
2169 	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
2170 	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
2171 	    im6o->im6o_memberships.lh_first == NULL) {
2172 		free(*im6op, M_IPMOPTS);
2173 		*im6op = NULL;
2174 	}
2175 
2176 	return(error);
2177 }
2178 
2179 /*
2180  * Return the IP6 multicast options in response to user getsockopt().
2181  */
2182 static int
2183 ip6_getmoptions(int optname, struct ip6_moptions *im6o, struct mbuf **mp)
2184 {
2185 	u_int *hlim, *loop, *ifindex;
2186 
2187 	*mp = m_get(MB_WAIT, MT_HEADER);		/* XXX */
2188 
2189 	switch (optname) {
2190 
2191 	case IPV6_MULTICAST_IF:
2192 		ifindex = mtod(*mp, u_int *);
2193 		(*mp)->m_len = sizeof(u_int);
2194 		if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
2195 			*ifindex = 0;
2196 		else
2197 			*ifindex = im6o->im6o_multicast_ifp->if_index;
2198 		return(0);
2199 
2200 	case IPV6_MULTICAST_HOPS:
2201 		hlim = mtod(*mp, u_int *);
2202 		(*mp)->m_len = sizeof(u_int);
2203 		if (im6o == NULL)
2204 			*hlim = ip6_defmcasthlim;
2205 		else
2206 			*hlim = im6o->im6o_multicast_hlim;
2207 		return(0);
2208 
2209 	case IPV6_MULTICAST_LOOP:
2210 		loop = mtod(*mp, u_int *);
2211 		(*mp)->m_len = sizeof(u_int);
2212 		if (im6o == NULL)
2213 			*loop = ip6_defmcasthlim;
2214 		else
2215 			*loop = im6o->im6o_multicast_loop;
2216 		return(0);
2217 
2218 	default:
2219 		return(EOPNOTSUPP);
2220 	}
2221 }
2222 
2223 /*
2224  * Discard the IP6 multicast options.
2225  */
2226 void
2227 ip6_freemoptions(struct ip6_moptions *im6o)
2228 {
2229 	struct in6_multi_mship *imm;
2230 
2231 	if (im6o == NULL)
2232 		return;
2233 
2234 	while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
2235 		LIST_REMOVE(imm, i6mm_chain);
2236 		if (imm->i6mm_maddr)
2237 			in6_delmulti(imm->i6mm_maddr);
2238 		free(imm, M_IPMADDR);
2239 	}
2240 	free(im6o, M_IPMOPTS);
2241 }
2242 
2243 /*
2244  * Set IPv6 outgoing packet options based on advanced API.
2245  */
2246 int
2247 ip6_setpktoptions(struct mbuf *control, struct ip6_pktopts *opt, int priv,
2248 		  int needcopy)
2249 {
2250 	struct cmsghdr *cm = 0;
2251 
2252 	if (control == 0 || opt == 0)
2253 		return(EINVAL);
2254 
2255 	init_ip6pktopts(opt);
2256 
2257 	/*
2258 	 * XXX: Currently, we assume all the optional information is stored
2259 	 * in a single mbuf.
2260 	 */
2261 	if (control->m_next)
2262 		return(EINVAL);
2263 
2264 	for (; control->m_len; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2265 		     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2266 		cm = mtod(control, struct cmsghdr *);
2267 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2268 			return(EINVAL);
2269 		if (cm->cmsg_level != IPPROTO_IPV6)
2270 			continue;
2271 
2272 		/*
2273 		 * XXX should check if RFC2292 API is mixed with 2292bis API
2274 		 */
2275 		switch (cm->cmsg_type) {
2276 		case IPV6_PKTINFO:
2277 			if (cm->cmsg_len != CMSG_LEN(sizeof(struct in6_pktinfo)))
2278 				return(EINVAL);
2279 			if (needcopy) {
2280 				/* XXX: Is it really WAITOK? */
2281 				opt->ip6po_pktinfo =
2282 					malloc(sizeof(struct in6_pktinfo),
2283 					       M_IP6OPT, M_WAITOK);
2284 				bcopy(CMSG_DATA(cm), opt->ip6po_pktinfo,
2285 				    sizeof(struct in6_pktinfo));
2286 			} else
2287 				opt->ip6po_pktinfo =
2288 					(struct in6_pktinfo *)CMSG_DATA(cm);
2289 			if (opt->ip6po_pktinfo->ipi6_ifindex &&
2290 			    IN6_IS_ADDR_LINKLOCAL(&opt->ip6po_pktinfo->ipi6_addr))
2291 				opt->ip6po_pktinfo->ipi6_addr.s6_addr16[1] =
2292 					htons(opt->ip6po_pktinfo->ipi6_ifindex);
2293 
2294 			if (opt->ip6po_pktinfo->ipi6_ifindex > if_index
2295 			 || opt->ip6po_pktinfo->ipi6_ifindex < 0) {
2296 				return(ENXIO);
2297 			}
2298 
2299 			/*
2300 			 * Check if the requested source address is indeed a
2301 			 * unicast address assigned to the node, and can be
2302 			 * used as the packet's source address.
2303 			 */
2304 			if (!IN6_IS_ADDR_UNSPECIFIED(&opt->ip6po_pktinfo->ipi6_addr)) {
2305 				struct in6_ifaddr *ia6;
2306 				struct sockaddr_in6 sin6;
2307 
2308 				bzero(&sin6, sizeof(sin6));
2309 				sin6.sin6_len = sizeof(sin6);
2310 				sin6.sin6_family = AF_INET6;
2311 				sin6.sin6_addr =
2312 					opt->ip6po_pktinfo->ipi6_addr;
2313 				ia6 = (struct in6_ifaddr *)ifa_ifwithaddr(sin6tosa(&sin6));
2314 				if (ia6 == NULL ||
2315 				    (ia6->ia6_flags & (IN6_IFF_ANYCAST |
2316 						       IN6_IFF_NOTREADY)) != 0)
2317 					return(EADDRNOTAVAIL);
2318 			}
2319 			break;
2320 
2321 		case IPV6_HOPLIMIT:
2322 			if (cm->cmsg_len != CMSG_LEN(sizeof(int)))
2323 				return(EINVAL);
2324 
2325 			opt->ip6po_hlim = *(int *)CMSG_DATA(cm);
2326 			if (opt->ip6po_hlim < -1 || opt->ip6po_hlim > 255)
2327 				return(EINVAL);
2328 			break;
2329 
2330 		case IPV6_NEXTHOP:
2331 			if (!priv)
2332 				return(EPERM);
2333 
2334 			if (cm->cmsg_len < sizeof(u_char) ||
2335 			    /* check if cmsg_len is large enough for sa_len */
2336 			    cm->cmsg_len < CMSG_LEN(*CMSG_DATA(cm)))
2337 				return(EINVAL);
2338 
2339 			if (needcopy) {
2340 				opt->ip6po_nexthop =
2341 					malloc(*CMSG_DATA(cm),
2342 					       M_IP6OPT, M_WAITOK);
2343 				bcopy(CMSG_DATA(cm),
2344 				      opt->ip6po_nexthop,
2345 				      *CMSG_DATA(cm));
2346 			} else
2347 				opt->ip6po_nexthop =
2348 					(struct sockaddr *)CMSG_DATA(cm);
2349 			break;
2350 
2351 		case IPV6_HOPOPTS:
2352 		{
2353 			struct ip6_hbh *hbh;
2354 			int hbhlen;
2355 
2356 			if (cm->cmsg_len < CMSG_LEN(sizeof(struct ip6_hbh)))
2357 				return(EINVAL);
2358 			hbh = (struct ip6_hbh *)CMSG_DATA(cm);
2359 			hbhlen = (hbh->ip6h_len + 1) << 3;
2360 			if (cm->cmsg_len != CMSG_LEN(hbhlen))
2361 				return(EINVAL);
2362 
2363 			if (needcopy) {
2364 				opt->ip6po_hbh =
2365 					malloc(hbhlen, M_IP6OPT, M_WAITOK);
2366 				bcopy(hbh, opt->ip6po_hbh, hbhlen);
2367 			} else
2368 				opt->ip6po_hbh = hbh;
2369 			break;
2370 		}
2371 
2372 		case IPV6_DSTOPTS:
2373 		{
2374 			struct ip6_dest *dest, **newdest;
2375 			int destlen;
2376 
2377 			if (cm->cmsg_len < CMSG_LEN(sizeof(struct ip6_dest)))
2378 				return(EINVAL);
2379 			dest = (struct ip6_dest *)CMSG_DATA(cm);
2380 			destlen = (dest->ip6d_len + 1) << 3;
2381 			if (cm->cmsg_len != CMSG_LEN(destlen))
2382 				return(EINVAL);
2383 
2384 			/*
2385 			 * The old advacned API is ambiguous on this
2386 			 * point. Our approach is to determine the
2387 			 * position based according to the existence
2388 			 * of a routing header. Note, however, that
2389 			 * this depends on the order of the extension
2390 			 * headers in the ancillary data; the 1st part
2391 			 * of the destination options header must
2392 			 * appear before the routing header in the
2393 			 * ancillary data, too.
2394 			 * RFC2292bis solved the ambiguity by
2395 			 * introducing separate cmsg types.
2396 			 */
2397 			if (opt->ip6po_rthdr == NULL)
2398 				newdest = &opt->ip6po_dest1;
2399 			else
2400 				newdest = &opt->ip6po_dest2;
2401 
2402 			if (needcopy) {
2403 				*newdest = malloc(destlen, M_IP6OPT, M_WAITOK);
2404 				bcopy(dest, *newdest, destlen);
2405 			} else
2406 				*newdest = dest;
2407 
2408 			break;
2409 		}
2410 
2411 		case IPV6_RTHDR:
2412 		{
2413 			struct ip6_rthdr *rth;
2414 			int rthlen;
2415 
2416 			if (cm->cmsg_len < CMSG_LEN(sizeof(struct ip6_rthdr)))
2417 				return(EINVAL);
2418 			rth = (struct ip6_rthdr *)CMSG_DATA(cm);
2419 			rthlen = (rth->ip6r_len + 1) << 3;
2420 			if (cm->cmsg_len != CMSG_LEN(rthlen))
2421 				return(EINVAL);
2422 
2423 			switch (rth->ip6r_type) {
2424 			case IPV6_RTHDR_TYPE_0:
2425 				/* must contain one addr */
2426 				if (rth->ip6r_len == 0)
2427 					return(EINVAL);
2428 				/* length must be even */
2429 				if (rth->ip6r_len % 2)
2430 					return(EINVAL);
2431 				if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2432 					return(EINVAL);
2433 				break;
2434 			default:
2435 				return(EINVAL);	/* not supported */
2436 			}
2437 
2438 			if (needcopy) {
2439 				opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT,
2440 							  M_WAITOK);
2441 				bcopy(rth, opt->ip6po_rthdr, rthlen);
2442 			} else
2443 				opt->ip6po_rthdr = rth;
2444 
2445 			break;
2446 		}
2447 
2448 		default:
2449 			return(ENOPROTOOPT);
2450 		}
2451 	}
2452 
2453 	return(0);
2454 }
2455 
2456 /*
2457  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2458  * packet to the input queue of a specified interface.  Note that this
2459  * calls the output routine of the loopback "driver", but with an interface
2460  * pointer that might NOT be &loif -- easier than replicating that code here.
2461  */
2462 void
2463 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2464 {
2465 	struct mbuf *copym;
2466 	struct ip6_hdr *ip6;
2467 
2468 	copym = m_copy(m, 0, M_COPYALL);
2469 	if (copym == NULL)
2470 		return;
2471 
2472 	/*
2473 	 * Make sure to deep-copy IPv6 header portion in case the data
2474 	 * is in an mbuf cluster, so that we can safely override the IPv6
2475 	 * header portion later.
2476 	 */
2477 	if ((copym->m_flags & M_EXT) != 0 ||
2478 	    copym->m_len < sizeof(struct ip6_hdr)) {
2479 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
2480 		if (copym == NULL)
2481 			return;
2482 	}
2483 
2484 #ifdef DIAGNOSTIC
2485 	if (copym->m_len < sizeof(*ip6)) {
2486 		m_freem(copym);
2487 		return;
2488 	}
2489 #endif
2490 
2491 	ip6 = mtod(copym, struct ip6_hdr *);
2492 	/*
2493 	 * clear embedded scope identifiers if necessary.
2494 	 * in6_clearscope will touch the addresses only when necessary.
2495 	 */
2496 	in6_clearscope(&ip6->ip6_src);
2497 	in6_clearscope(&ip6->ip6_dst);
2498 
2499 	(void)if_simloop(ifp, copym, dst->sin6_family, NULL);
2500 }
2501 
2502 /*
2503  * Chop IPv6 header off from the payload.
2504  */
2505 static int
2506 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
2507 {
2508 	struct mbuf *mh;
2509 	struct ip6_hdr *ip6;
2510 
2511 	ip6 = mtod(m, struct ip6_hdr *);
2512 	if (m->m_len > sizeof(*ip6)) {
2513 		MGETHDR(mh, MB_DONTWAIT, MT_HEADER);
2514 		if (mh == 0) {
2515 			m_freem(m);
2516 			return ENOBUFS;
2517 		}
2518 		M_MOVE_PKTHDR(mh, m);
2519 		MH_ALIGN(mh, sizeof(*ip6));
2520 		m->m_len -= sizeof(*ip6);
2521 		m->m_data += sizeof(*ip6);
2522 		mh->m_next = m;
2523 		m = mh;
2524 		m->m_len = sizeof(*ip6);
2525 		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
2526 	}
2527 	exthdrs->ip6e_ip6 = m;
2528 	return 0;
2529 }
2530 
2531 /*
2532  * Compute IPv6 extension header length.
2533  */
2534 int
2535 ip6_optlen(struct in6pcb *in6p)
2536 {
2537 	int len;
2538 
2539 	if (!in6p->in6p_outputopts)
2540 		return 0;
2541 
2542 	len = 0;
2543 #define elen(x) \
2544     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
2545 
2546 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
2547 	if (in6p->in6p_outputopts->ip6po_rthdr)
2548 		/* dest1 is valid with rthdr only */
2549 		len += elen(in6p->in6p_outputopts->ip6po_dest1);
2550 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
2551 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
2552 	return len;
2553 #undef elen
2554 }
2555