ip6_output.c revision 106259
1/*	$FreeBSD: head/sys/netinet6/ip6_output.c 106259 2002-10-31 19:45:48Z ume $	*/
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. All advertising materials mentioning features or use of this software
46 *    must display the following acknowledgement:
47 *	This product includes software developed by the University of
48 *	California, Berkeley and its contributors.
49 * 4. Neither the name of the University nor the names of its contributors
50 *    may be used to endorse or promote products derived from this software
51 *    without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 *
65 *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
66 */
67
68#include "opt_ip6fw.h"
69#include "opt_inet.h"
70#include "opt_inet6.h"
71#include "opt_ipsec.h"
72#include "opt_pfil_hooks.h"
73
74#include <sys/param.h>
75#include <sys/malloc.h>
76#include <sys/mbuf.h>
77#include <sys/proc.h>
78#include <sys/errno.h>
79#include <sys/protosw.h>
80#include <sys/socket.h>
81#include <sys/socketvar.h>
82#include <sys/systm.h>
83#include <sys/kernel.h>
84
85#include <net/if.h>
86#include <net/route.h>
87#ifdef PFIL_HOOKS
88#include <net/pfil.h>
89#endif
90
91#include <netinet/in.h>
92#include <netinet/in_var.h>
93#include <netinet6/in6_var.h>
94#include <netinet/ip6.h>
95#include <netinet/icmp6.h>
96#include <netinet6/ip6_var.h>
97#include <netinet/in_pcb.h>
98#include <netinet6/nd6.h>
99
100#ifdef IPSEC
101#include <netinet6/ipsec.h>
102#ifdef INET6
103#include <netinet6/ipsec6.h>
104#endif
105#include <netkey/key.h>
106#endif /* IPSEC */
107
108#ifdef FAST_IPSEC
109#include <netipsec/ipsec.h>
110#include <netipsec/ipsec6.h>
111#include <netipsec/key.h>
112#endif /* FAST_IPSEC */
113
114#include <netinet6/ip6_fw.h>
115
116#include <net/net_osdep.h>
117
118#include <netinet6/ip6protosw.h>
119
120static MALLOC_DEFINE(M_IPMOPTS, "ip6_moptions", "internet multicast options");
121
122struct ip6_exthdrs {
123	struct mbuf *ip6e_ip6;
124	struct mbuf *ip6e_hbh;
125	struct mbuf *ip6e_dest1;
126	struct mbuf *ip6e_rthdr;
127	struct mbuf *ip6e_dest2;
128};
129
130static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
131			    struct socket *, struct sockopt *sopt));
132static int ip6_setmoptions __P((int, struct ip6_moptions **, struct mbuf *));
133static int ip6_getmoptions __P((int, struct ip6_moptions *, struct mbuf **));
134static int ip6_copyexthdr __P((struct mbuf **, caddr_t, int));
135static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
136				  struct ip6_frag **));
137static int ip6_insert_jumboopt __P((struct ip6_exthdrs *, u_int32_t));
138static int ip6_splithdr __P((struct mbuf *, struct ip6_exthdrs *));
139
140/*
141 * IP6 output. The packet in mbuf chain m contains a skeletal IP6
142 * header (with pri, len, nxt, hlim, src, dst).
143 * This function may modify ver and hlim only.
144 * The mbuf chain containing the packet will be freed.
145 * The mbuf opt, if present, will not be freed.
146 *
147 * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
148 * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
149 * which is rt_rmx.rmx_mtu.
150 */
151int
152ip6_output(m0, opt, ro, flags, im6o, ifpp, inp)
153	struct mbuf *m0;
154	struct ip6_pktopts *opt;
155	struct route_in6 *ro;
156	int flags;
157	struct ip6_moptions *im6o;
158	struct ifnet **ifpp;		/* XXX: just for statistics */
159	struct inpcb *inp;
160{
161	struct ip6_hdr *ip6, *mhip6;
162	struct ifnet *ifp, *origifp;
163	struct mbuf *m = m0;
164	int hlen, tlen, len, off;
165	struct route_in6 ip6route;
166	struct sockaddr_in6 *dst;
167	int error = 0;
168	struct in6_ifaddr *ia = NULL;
169	u_long mtu;
170	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
171	struct ip6_exthdrs exthdrs;
172	struct in6_addr finaldst;
173	struct route_in6 *ro_pmtu = NULL;
174	int hdrsplit = 0;
175	int needipsec = 0;
176#ifdef PFIL_HOOKS
177	struct packet_filter_hook *pfh;
178	struct mbuf *m1;
179	int rv;
180#endif /* PFIL_HOOKS */
181#ifdef IPSEC
182	int needipsectun = 0;
183	struct secpolicy *sp = NULL;
184	struct socket *so = inp ? inp->inp_socket : NULL;
185
186	ip6 = mtod(m, struct ip6_hdr *);
187#endif /* IPSEC */
188#ifdef FAST_IPSEC
189	int needipsectun = 0;
190	struct secpolicy *sp = NULL;
191
192	ip6 = mtod(m, struct ip6_hdr *);
193#endif /* FAST_IPSEC */
194
195#define MAKE_EXTHDR(hp, mp)						\
196    do {								\
197	if (hp) {							\
198		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
199		error = ip6_copyexthdr((mp), (caddr_t)(hp), 		\
200				       ((eh)->ip6e_len + 1) << 3);	\
201		if (error)						\
202			goto freehdrs;					\
203	}								\
204    } while (0)
205
206	bzero(&exthdrs, sizeof(exthdrs));
207
208	if (opt) {
209		/* Hop-by-Hop options header */
210		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
211		/* Destination options header(1st part) */
212		MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
213		/* Routing header */
214		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
215		/* Destination options header(2nd part) */
216		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
217	}
218
219#ifdef IPSEC
220	/* get a security policy for this packet */
221	if (so == NULL)
222		sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
223	else
224		sp = ipsec6_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
225
226	if (sp == NULL) {
227		ipsec6stat.out_inval++;
228		goto freehdrs;
229	}
230
231	error = 0;
232
233	/* check policy */
234	switch (sp->policy) {
235	case IPSEC_POLICY_DISCARD:
236		/*
237		 * This packet is just discarded.
238		 */
239		ipsec6stat.out_polvio++;
240		goto freehdrs;
241
242	case IPSEC_POLICY_BYPASS:
243	case IPSEC_POLICY_NONE:
244		/* no need to do IPsec. */
245		needipsec = 0;
246		break;
247
248	case IPSEC_POLICY_IPSEC:
249		if (sp->req == NULL) {
250			/* acquire a policy */
251			error = key_spdacquire(sp);
252			goto freehdrs;
253		}
254		needipsec = 1;
255		break;
256
257	case IPSEC_POLICY_ENTRUST:
258	default:
259		printf("ip6_output: Invalid policy found. %d\n", sp->policy);
260	}
261#endif /* IPSEC */
262#ifdef FAST_IPSEC
263	/* get a security policy for this packet */
264	if (inp == NULL)
265		sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
266	else
267		sp = ipsec_getpolicybysock(m, IPSEC_DIR_OUTBOUND, inp, &error);
268
269	if (sp == NULL) {
270		newipsecstat.ips_out_inval++;
271		goto freehdrs;
272	}
273
274	error = 0;
275
276	/* check policy */
277	switch (sp->policy) {
278	case IPSEC_POLICY_DISCARD:
279		/*
280		 * This packet is just discarded.
281		 */
282		newipsecstat.ips_out_polvio++;
283		goto freehdrs;
284
285	case IPSEC_POLICY_BYPASS:
286	case IPSEC_POLICY_NONE:
287		/* no need to do IPsec. */
288		needipsec = 0;
289		break;
290
291	case IPSEC_POLICY_IPSEC:
292		if (sp->req == NULL) {
293			/* acquire a policy */
294			error = key_spdacquire(sp);
295			goto freehdrs;
296		}
297		needipsec = 1;
298		break;
299
300	case IPSEC_POLICY_ENTRUST:
301	default:
302		printf("ip6_output: Invalid policy found. %d\n", sp->policy);
303	}
304#endif /* FAST_IPSEC */
305
306	/*
307	 * Calculate the total length of the extension header chain.
308	 * Keep the length of the unfragmentable part for fragmentation.
309	 */
310	optlen = 0;
311	if (exthdrs.ip6e_hbh) optlen += exthdrs.ip6e_hbh->m_len;
312	if (exthdrs.ip6e_dest1) optlen += exthdrs.ip6e_dest1->m_len;
313	if (exthdrs.ip6e_rthdr) optlen += exthdrs.ip6e_rthdr->m_len;
314	unfragpartlen = optlen + sizeof(struct ip6_hdr);
315	/* NOTE: we don't add AH/ESP length here. do that later. */
316	if (exthdrs.ip6e_dest2) optlen += exthdrs.ip6e_dest2->m_len;
317
318	/*
319	 * If we need IPsec, or there is at least one extension header,
320	 * separate IP6 header from the payload.
321	 */
322	if ((needipsec || optlen) && !hdrsplit) {
323		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
324			m = NULL;
325			goto freehdrs;
326		}
327		m = exthdrs.ip6e_ip6;
328		hdrsplit++;
329	}
330
331	/* adjust pointer */
332	ip6 = mtod(m, struct ip6_hdr *);
333
334	/* adjust mbuf packet header length */
335	m->m_pkthdr.len += optlen;
336	plen = m->m_pkthdr.len - sizeof(*ip6);
337
338	/* If this is a jumbo payload, insert a jumbo payload option. */
339	if (plen > IPV6_MAXPACKET) {
340		if (!hdrsplit) {
341			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
342				m = NULL;
343				goto freehdrs;
344			}
345			m = exthdrs.ip6e_ip6;
346			hdrsplit++;
347		}
348		/* adjust pointer */
349		ip6 = mtod(m, struct ip6_hdr *);
350		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
351			goto freehdrs;
352		ip6->ip6_plen = 0;
353	} else
354		ip6->ip6_plen = htons(plen);
355
356	/*
357	 * Concatenate headers and fill in next header fields.
358	 * Here we have, on "m"
359	 *	IPv6 payload
360	 * and we insert headers accordingly.  Finally, we should be getting:
361	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
362	 *
363	 * during the header composing process, "m" points to IPv6 header.
364	 * "mprev" points to an extension header prior to esp.
365	 */
366	{
367		u_char *nexthdrp = &ip6->ip6_nxt;
368		struct mbuf *mprev = m;
369
370		/*
371		 * we treat dest2 specially.  this makes IPsec processing
372		 * much easier.  the goal here is to make mprev point the
373		 * mbuf prior to dest2.
374		 *
375		 * result: IPv6 dest2 payload
376		 * m and mprev will point to IPv6 header.
377		 */
378		if (exthdrs.ip6e_dest2) {
379			if (!hdrsplit)
380				panic("assumption failed: hdr not split");
381			exthdrs.ip6e_dest2->m_next = m->m_next;
382			m->m_next = exthdrs.ip6e_dest2;
383			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
384			ip6->ip6_nxt = IPPROTO_DSTOPTS;
385		}
386
387#define MAKE_CHAIN(m, mp, p, i)\
388    do {\
389	if (m) {\
390		if (!hdrsplit) \
391			panic("assumption failed: hdr not split"); \
392		*mtod((m), u_char *) = *(p);\
393		*(p) = (i);\
394		p = mtod((m), u_char *);\
395		(m)->m_next = (mp)->m_next;\
396		(mp)->m_next = (m);\
397		(mp) = (m);\
398	}\
399    } while (0)
400		/*
401		 * result: IPv6 hbh dest1 rthdr dest2 payload
402		 * m will point to IPv6 header.  mprev will point to the
403		 * extension header prior to dest2 (rthdr in the above case).
404		 */
405		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev,
406			   nexthdrp, IPPROTO_HOPOPTS);
407		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev,
408			   nexthdrp, IPPROTO_DSTOPTS);
409		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev,
410			   nexthdrp, IPPROTO_ROUTING);
411
412#if defined(IPSEC) || defined(FAST_IPSEC)
413		if (!needipsec)
414			goto skip_ipsec2;
415
416		/*
417		 * pointers after IPsec headers are not valid any more.
418		 * other pointers need a great care too.
419		 * (IPsec routines should not mangle mbufs prior to AH/ESP)
420		 */
421		exthdrs.ip6e_dest2 = NULL;
422
423	    {
424		struct ip6_rthdr *rh = NULL;
425		int segleft_org = 0;
426		struct ipsec_output_state state;
427
428		if (exthdrs.ip6e_rthdr) {
429			rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
430			segleft_org = rh->ip6r_segleft;
431			rh->ip6r_segleft = 0;
432		}
433
434		bzero(&state, sizeof(state));
435		state.m = m;
436		error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
437			&needipsectun);
438		m = state.m;
439		if (error) {
440			/* mbuf is already reclaimed in ipsec6_output_trans. */
441			m = NULL;
442			switch (error) {
443			case EHOSTUNREACH:
444			case ENETUNREACH:
445			case EMSGSIZE:
446			case ENOBUFS:
447			case ENOMEM:
448				break;
449			default:
450				printf("ip6_output (ipsec): error code %d\n", error);
451				/* fall through */
452			case ENOENT:
453				/* don't show these error codes to the user */
454				error = 0;
455				break;
456			}
457			goto bad;
458		}
459		if (exthdrs.ip6e_rthdr) {
460			/* ah6_output doesn't modify mbuf chain */
461			rh->ip6r_segleft = segleft_org;
462		}
463	    }
464skip_ipsec2:;
465#endif
466	}
467
468	/*
469	 * If there is a routing header, replace destination address field
470	 * with the first hop of the routing header.
471	 */
472	if (exthdrs.ip6e_rthdr) {
473		struct ip6_rthdr *rh =
474			(struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
475						  struct ip6_rthdr *));
476		struct ip6_rthdr0 *rh0;
477
478		finaldst = ip6->ip6_dst;
479		switch (rh->ip6r_type) {
480		case IPV6_RTHDR_TYPE_0:
481			 rh0 = (struct ip6_rthdr0 *)rh;
482			 ip6->ip6_dst = rh0->ip6r0_addr[0];
483			 bcopy((caddr_t)&rh0->ip6r0_addr[1],
484			       (caddr_t)&rh0->ip6r0_addr[0],
485			       sizeof(struct in6_addr)*(rh0->ip6r0_segleft - 1)
486				 );
487			 rh0->ip6r0_addr[rh0->ip6r0_segleft - 1] = finaldst;
488			 break;
489		default:	/* is it possible? */
490			 error = EINVAL;
491			 goto bad;
492		}
493	}
494
495	/* Source address validation */
496	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
497	    (flags & IPV6_DADOUTPUT) == 0) {
498		error = EOPNOTSUPP;
499		ip6stat.ip6s_badscope++;
500		goto bad;
501	}
502	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
503		error = EOPNOTSUPP;
504		ip6stat.ip6s_badscope++;
505		goto bad;
506	}
507
508	ip6stat.ip6s_localout++;
509
510	/*
511	 * Route packet.
512	 */
513	if (ro == 0) {
514		ro = &ip6route;
515		bzero((caddr_t)ro, sizeof(*ro));
516	}
517	ro_pmtu = ro;
518	if (opt && opt->ip6po_rthdr)
519		ro = &opt->ip6po_route;
520	dst = (struct sockaddr_in6 *)&ro->ro_dst;
521	/*
522	 * If there is a cached route,
523	 * check that it is to the same destination
524	 * and is still up. If not, free it and try again.
525	 */
526	if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
527			 dst->sin6_family != AF_INET6 ||
528			 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_dst))) {
529		RTFREE(ro->ro_rt);
530		ro->ro_rt = (struct rtentry *)0;
531	}
532	if (ro->ro_rt == 0) {
533		bzero(dst, sizeof(*dst));
534		dst->sin6_family = AF_INET6;
535		dst->sin6_len = sizeof(struct sockaddr_in6);
536		dst->sin6_addr = ip6->ip6_dst;
537#ifdef SCOPEDROUTING
538		/* XXX: sin6_scope_id should already be fixed at this point */
539		if (IN6_IS_SCOPE_LINKLOCAL(&dst->sin6_addr))
540			dst->sin6_scope_id = ntohs(dst->sin6_addr.s6_addr16[1]);
541#endif
542	}
543#if defined(IPSEC) || defined(FAST_IPSEC)
544	if (needipsec && needipsectun) {
545		struct ipsec_output_state state;
546
547		/*
548		 * All the extension headers will become inaccessible
549		 * (since they can be encrypted).
550		 * Don't panic, we need no more updates to extension headers
551		 * on inner IPv6 packet (since they are now encapsulated).
552		 *
553		 * IPv6 [ESP|AH] IPv6 [extension headers] payload
554		 */
555		bzero(&exthdrs, sizeof(exthdrs));
556		exthdrs.ip6e_ip6 = m;
557
558		bzero(&state, sizeof(state));
559		state.m = m;
560		state.ro = (struct route *)ro;
561		state.dst = (struct sockaddr *)dst;
562
563		error = ipsec6_output_tunnel(&state, sp, flags);
564
565		m = state.m;
566		ro = (struct route_in6 *)state.ro;
567		dst = (struct sockaddr_in6 *)state.dst;
568		if (error) {
569			/* mbuf is already reclaimed in ipsec6_output_tunnel. */
570			m0 = m = NULL;
571			m = NULL;
572			switch (error) {
573			case EHOSTUNREACH:
574			case ENETUNREACH:
575			case EMSGSIZE:
576			case ENOBUFS:
577			case ENOMEM:
578				break;
579			default:
580				printf("ip6_output (ipsec): error code %d\n", error);
581				/* fall through */
582			case ENOENT:
583				/* don't show these error codes to the user */
584				error = 0;
585				break;
586			}
587			goto bad;
588		}
589
590		exthdrs.ip6e_ip6 = m;
591	}
592#endif /* IPSEC */
593
594	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
595		/* Unicast */
596
597#define ifatoia6(ifa)	((struct in6_ifaddr *)(ifa))
598#define sin6tosa(sin6)	((struct sockaddr *)(sin6))
599		/* xxx
600		 * interface selection comes here
601		 * if an interface is specified from an upper layer,
602		 * ifp must point it.
603		 */
604		if (ro->ro_rt == 0) {
605			/*
606			 * non-bsdi always clone routes, if parent is
607			 * PRF_CLONING.
608			 */
609			rtalloc((struct route *)ro);
610		}
611		if (ro->ro_rt == 0) {
612			ip6stat.ip6s_noroute++;
613			error = EHOSTUNREACH;
614			/* XXX in6_ifstat_inc(ifp, ifs6_out_discard); */
615			goto bad;
616		}
617		ia = ifatoia6(ro->ro_rt->rt_ifa);
618		ifp = ro->ro_rt->rt_ifp;
619		ro->ro_rt->rt_use++;
620		if (ro->ro_rt->rt_flags & RTF_GATEWAY)
621			dst = (struct sockaddr_in6 *)ro->ro_rt->rt_gateway;
622		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
623
624		in6_ifstat_inc(ifp, ifs6_out_request);
625
626		/*
627		 * Check if the outgoing interface conflicts with
628		 * the interface specified by ifi6_ifindex (if specified).
629		 * Note that loopback interface is always okay.
630		 * (this may happen when we are sending a packet to one of
631		 *  our own addresses.)
632		 */
633		if (opt && opt->ip6po_pktinfo
634		 && opt->ip6po_pktinfo->ipi6_ifindex) {
635			if (!(ifp->if_flags & IFF_LOOPBACK)
636			 && ifp->if_index != opt->ip6po_pktinfo->ipi6_ifindex) {
637				ip6stat.ip6s_noroute++;
638				in6_ifstat_inc(ifp, ifs6_out_discard);
639				error = EHOSTUNREACH;
640				goto bad;
641			}
642		}
643
644		if (opt && opt->ip6po_hlim != -1)
645			ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
646	} else {
647		/* Multicast */
648		struct	in6_multi *in6m;
649
650		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
651
652		/*
653		 * See if the caller provided any multicast options
654		 */
655		ifp = NULL;
656		if (im6o != NULL) {
657			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
658			if (im6o->im6o_multicast_ifp != NULL)
659				ifp = im6o->im6o_multicast_ifp;
660		} else
661			ip6->ip6_hlim = ip6_defmcasthlim;
662
663		/*
664		 * See if the caller provided the outgoing interface
665		 * as an ancillary data.
666		 * Boundary check for ifindex is assumed to be already done.
667		 */
668		if (opt && opt->ip6po_pktinfo && opt->ip6po_pktinfo->ipi6_ifindex)
669			ifp = ifnet_byindex(opt->ip6po_pktinfo->ipi6_ifindex);
670
671		/*
672		 * If the destination is a node-local scope multicast,
673		 * the packet should be loop-backed only.
674		 */
675		if (IN6_IS_ADDR_MC_NODELOCAL(&ip6->ip6_dst)) {
676			/*
677			 * If the outgoing interface is already specified,
678			 * it should be a loopback interface.
679			 */
680			if (ifp && (ifp->if_flags & IFF_LOOPBACK) == 0) {
681				ip6stat.ip6s_badscope++;
682				error = ENETUNREACH; /* XXX: better error? */
683				/* XXX correct ifp? */
684				in6_ifstat_inc(ifp, ifs6_out_discard);
685				goto bad;
686			} else {
687				ifp = &loif[0];
688			}
689		}
690
691		if (opt && opt->ip6po_hlim != -1)
692			ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
693
694		/*
695		 * If caller did not provide an interface lookup a
696		 * default in the routing table.  This is either a
697		 * default for the speicfied group (i.e. a host
698		 * route), or a multicast default (a route for the
699		 * ``net'' ff00::/8).
700		 */
701		if (ifp == NULL) {
702			if (ro->ro_rt == 0) {
703				ro->ro_rt = rtalloc1((struct sockaddr *)
704						&ro->ro_dst, 0, 0UL);
705			}
706			if (ro->ro_rt == 0) {
707				ip6stat.ip6s_noroute++;
708				error = EHOSTUNREACH;
709				/* XXX in6_ifstat_inc(ifp, ifs6_out_discard) */
710				goto bad;
711			}
712			ia = ifatoia6(ro->ro_rt->rt_ifa);
713			ifp = ro->ro_rt->rt_ifp;
714			ro->ro_rt->rt_use++;
715		}
716
717		if ((flags & IPV6_FORWARDING) == 0)
718			in6_ifstat_inc(ifp, ifs6_out_request);
719		in6_ifstat_inc(ifp, ifs6_out_mcast);
720
721		/*
722		 * Confirm that the outgoing interface supports multicast.
723		 */
724		if ((ifp->if_flags & IFF_MULTICAST) == 0) {
725			ip6stat.ip6s_noroute++;
726			in6_ifstat_inc(ifp, ifs6_out_discard);
727			error = ENETUNREACH;
728			goto bad;
729		}
730		IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
731		if (in6m != NULL &&
732		   (im6o == NULL || im6o->im6o_multicast_loop)) {
733			/*
734			 * If we belong to the destination multicast group
735			 * on the outgoing interface, and the caller did not
736			 * forbid loopback, loop back a copy.
737			 */
738			ip6_mloopback(ifp, m, dst);
739		} else {
740			/*
741			 * If we are acting as a multicast router, perform
742			 * multicast forwarding as if the packet had just
743			 * arrived on the interface to which we are about
744			 * to send.  The multicast forwarding function
745			 * recursively calls this function, using the
746			 * IPV6_FORWARDING flag to prevent infinite recursion.
747			 *
748			 * Multicasts that are looped back by ip6_mloopback(),
749			 * above, will be forwarded by the ip6_input() routine,
750			 * if necessary.
751			 */
752			if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
753				if (ip6_mforward(ip6, ifp, m) != 0) {
754					m_freem(m);
755					goto done;
756				}
757			}
758		}
759		/*
760		 * Multicasts with a hoplimit of zero may be looped back,
761		 * above, but must not be transmitted on a network.
762		 * Also, multicasts addressed to the loopback interface
763		 * are not sent -- the above call to ip6_mloopback() will
764		 * loop back a copy if this host actually belongs to the
765		 * destination group on the loopback interface.
766		 */
767		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK)) {
768			m_freem(m);
769			goto done;
770		}
771	}
772
773	/*
774	 * Fill the outgoing inteface to tell the upper layer
775	 * to increment per-interface statistics.
776	 */
777	if (ifpp)
778		*ifpp = ifp;
779
780	/*
781	 * Determine path MTU.
782	 */
783	if (ro_pmtu != ro) {
784		/* The first hop and the final destination may differ. */
785		struct sockaddr_in6 *sin6_fin =
786			(struct sockaddr_in6 *)&ro_pmtu->ro_dst;
787		if (ro_pmtu->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
788				       !IN6_ARE_ADDR_EQUAL(&sin6_fin->sin6_addr,
789							   &finaldst))) {
790			RTFREE(ro_pmtu->ro_rt);
791			ro_pmtu->ro_rt = (struct rtentry *)0;
792		}
793		if (ro_pmtu->ro_rt == 0) {
794			bzero(sin6_fin, sizeof(*sin6_fin));
795			sin6_fin->sin6_family = AF_INET6;
796			sin6_fin->sin6_len = sizeof(struct sockaddr_in6);
797			sin6_fin->sin6_addr = finaldst;
798
799			rtalloc((struct route *)ro_pmtu);
800		}
801	}
802	if (ro_pmtu->ro_rt != NULL) {
803		u_int32_t ifmtu = nd_ifinfo[ifp->if_index].linkmtu;
804
805		mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
806		if (mtu > ifmtu || mtu == 0) {
807			/*
808			 * The MTU on the route is larger than the MTU on
809			 * the interface!  This shouldn't happen, unless the
810			 * MTU of the interface has been changed after the
811			 * interface was brought up.  Change the MTU in the
812			 * route to match the interface MTU (as long as the
813			 * field isn't locked).
814			 *
815			 * if MTU on the route is 0, we need to fix the MTU.
816			 * this case happens with path MTU discovery timeouts.
817			 */
818			 mtu = ifmtu;
819			 if ((ro_pmtu->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0)
820				 ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu; /* XXX */
821		}
822	} else {
823		mtu = nd_ifinfo[ifp->if_index].linkmtu;
824	}
825
826	/*
827	 * advanced API (IPV6_USE_MIN_MTU) overrides mtu setting
828	 */
829	if ((flags & IPV6_MINMTU) != 0 && mtu > IPV6_MMTU)
830		mtu = IPV6_MMTU;
831
832	/* Fake scoped addresses */
833	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
834		/*
835		 * If source or destination address is a scoped address, and
836		 * the packet is going to be sent to a loopback interface,
837		 * we should keep the original interface.
838		 */
839
840		/*
841		 * XXX: this is a very experimental and temporary solution.
842		 * We eventually have sockaddr_in6 and use the sin6_scope_id
843		 * field of the structure here.
844		 * We rely on the consistency between two scope zone ids
845		 * of source and destination, which should already be assured.
846		 * Larger scopes than link will be supported in the future.
847		 */
848		origifp = NULL;
849		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
850			origifp = ifnet_byindex(ntohs(ip6->ip6_src.s6_addr16[1]));
851		else if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
852			origifp = ifnet_byindex(ntohs(ip6->ip6_dst.s6_addr16[1]));
853		/*
854		 * XXX: origifp can be NULL even in those two cases above.
855		 * For example, if we remove the (only) link-local address
856		 * from the loopback interface, and try to send a link-local
857		 * address without link-id information.  Then the source
858		 * address is ::1, and the destination address is the
859		 * link-local address with its s6_addr16[1] being zero.
860		 * What is worse, if the packet goes to the loopback interface
861		 * by a default rejected route, the null pointer would be
862		 * passed to looutput, and the kernel would hang.
863		 * The following last resort would prevent such disaster.
864		 */
865		if (origifp == NULL)
866			origifp = ifp;
867	}
868	else
869		origifp = ifp;
870#ifndef SCOPEDROUTING
871	/*
872	 * clear embedded scope identifiers if necessary.
873	 * in6_clearscope will touch the addresses only when necessary.
874	 */
875	in6_clearscope(&ip6->ip6_src);
876	in6_clearscope(&ip6->ip6_dst);
877#endif
878
879	/*
880	 * Check with the firewall...
881	 */
882        if (ip6_fw_enable && ip6_fw_chk_ptr) {
883		u_short port = 0;
884		m->m_pkthdr.rcvif = NULL;	/* XXX */
885		/* If ipfw says divert, we have to just drop packet */
886		if ((*ip6_fw_chk_ptr)(&ip6, ifp, &port, &m)) {
887			m_freem(m);
888			goto done;
889		}
890		if (!m) {
891			error = EACCES;
892			goto done;
893		}
894	}
895
896	/*
897	 * If the outgoing packet contains a hop-by-hop options header,
898	 * it must be examined and processed even by the source node.
899	 * (RFC 2460, section 4.)
900	 */
901	if (exthdrs.ip6e_hbh) {
902		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
903		u_int32_t dummy1; /* XXX unused */
904		u_int32_t dummy2; /* XXX unused */
905
906#ifdef DIAGNOSTIC
907		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
908			panic("ip6e_hbh is not continuous");
909#endif
910		/*
911		 *  XXX: if we have to send an ICMPv6 error to the sender,
912		 *       we need the M_LOOP flag since icmp6_error() expects
913		 *       the IPv6 and the hop-by-hop options header are
914		 *       continuous unless the flag is set.
915		 */
916		m->m_flags |= M_LOOP;
917		m->m_pkthdr.rcvif = ifp;
918		if (ip6_process_hopopts(m,
919					(u_int8_t *)(hbh + 1),
920					((hbh->ip6h_len + 1) << 3) -
921					sizeof(struct ip6_hbh),
922					&dummy1, &dummy2) < 0) {
923			/* m was already freed at this point */
924			error = EINVAL;/* better error? */
925			goto done;
926		}
927		m->m_flags &= ~M_LOOP; /* XXX */
928		m->m_pkthdr.rcvif = NULL;
929	}
930
931#ifdef PFIL_HOOKS
932	/*
933	 * Run through list of hooks for output packets.
934	 */
935	m1 = m;
936	pfh = pfil_hook_get(PFIL_OUT, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh);
937	for (; pfh; pfh = pfh->pfil_link.tqe_next)
938		if (pfh->pfil_func) {
939			rv = pfh->pfil_func(ip6, sizeof(*ip6), ifp, 1, &m1);
940			if (rv) {
941				error = EHOSTUNREACH;
942				goto done;
943			}
944			m = m1;
945			if (m == NULL)
946				goto done;
947			ip6 = mtod(m, struct ip6_hdr *);
948		}
949#endif /* PFIL_HOOKS */
950	/*
951	 * Send the packet to the outgoing interface.
952	 * If necessary, do IPv6 fragmentation before sending.
953	 */
954	tlen = m->m_pkthdr.len;
955	if (tlen <= mtu
956#ifdef notyet
957	    /*
958	     * On any link that cannot convey a 1280-octet packet in one piece,
959	     * link-specific fragmentation and reassembly must be provided at
960	     * a layer below IPv6. [RFC 2460, sec.5]
961	     * Thus if the interface has ability of link-level fragmentation,
962	     * we can just send the packet even if the packet size is
963	     * larger than the link's MTU.
964	     * XXX: IFF_FRAGMENTABLE (or such) flag has not been defined yet...
965	     */
966
967	    || ifp->if_flags & IFF_FRAGMENTABLE
968#endif
969	    )
970	{
971 		/* Record statistics for this interface address. */
972 		if (ia && !(flags & IPV6_FORWARDING)) {
973 			ia->ia_ifa.if_opackets++;
974 			ia->ia_ifa.if_obytes += m->m_pkthdr.len;
975 		}
976#ifdef IPSEC
977		/* clean ipsec history once it goes out of the node */
978		ipsec_delaux(m);
979#endif
980		error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
981		goto done;
982	} else if (mtu < IPV6_MMTU) {
983		/*
984		 * note that path MTU is never less than IPV6_MMTU
985		 * (see icmp6_input).
986		 */
987		error = EMSGSIZE;
988		in6_ifstat_inc(ifp, ifs6_out_fragfail);
989		goto bad;
990	} else if (ip6->ip6_plen == 0) { /* jumbo payload cannot be fragmented */
991		error = EMSGSIZE;
992		in6_ifstat_inc(ifp, ifs6_out_fragfail);
993		goto bad;
994	} else {
995		struct mbuf **mnext, *m_frgpart;
996		struct ip6_frag *ip6f;
997		u_int32_t id = htonl(ip6_id++);
998		u_char nextproto;
999
1000		/*
1001		 * Too large for the destination or interface;
1002		 * fragment if possible.
1003		 * Must be able to put at least 8 bytes per fragment.
1004		 */
1005		hlen = unfragpartlen;
1006		if (mtu > IPV6_MAXPACKET)
1007			mtu = IPV6_MAXPACKET;
1008
1009		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
1010		if (len < 8) {
1011			error = EMSGSIZE;
1012			in6_ifstat_inc(ifp, ifs6_out_fragfail);
1013			goto bad;
1014		}
1015
1016		mnext = &m->m_nextpkt;
1017
1018		/*
1019		 * Change the next header field of the last header in the
1020		 * unfragmentable part.
1021		 */
1022		if (exthdrs.ip6e_rthdr) {
1023			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1024			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1025		} else if (exthdrs.ip6e_dest1) {
1026			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1027			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1028		} else if (exthdrs.ip6e_hbh) {
1029			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1030			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1031		} else {
1032			nextproto = ip6->ip6_nxt;
1033			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1034		}
1035
1036		/*
1037		 * Loop through length of segment after first fragment,
1038		 * make new header and copy data of each part and link onto
1039		 * chain.
1040		 */
1041		m0 = m;
1042		for (off = hlen; off < tlen; off += len) {
1043			MGETHDR(m, M_DONTWAIT, MT_HEADER);
1044			if (!m) {
1045				error = ENOBUFS;
1046				ip6stat.ip6s_odropped++;
1047				goto sendorfree;
1048			}
1049			m->m_pkthdr.rcvif = NULL;
1050			m->m_flags = m0->m_flags & M_COPYFLAGS;
1051			*mnext = m;
1052			mnext = &m->m_nextpkt;
1053			m->m_data += max_linkhdr;
1054			mhip6 = mtod(m, struct ip6_hdr *);
1055			*mhip6 = *ip6;
1056			m->m_len = sizeof(*mhip6);
1057 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1058 			if (error) {
1059				ip6stat.ip6s_odropped++;
1060				goto sendorfree;
1061			}
1062			ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1063			if (off + len >= tlen)
1064				len = tlen - off;
1065			else
1066				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1067			mhip6->ip6_plen = htons((u_short)(len + hlen +
1068							  sizeof(*ip6f) -
1069							  sizeof(struct ip6_hdr)));
1070			if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1071				error = ENOBUFS;
1072				ip6stat.ip6s_odropped++;
1073				goto sendorfree;
1074			}
1075			m_cat(m, m_frgpart);
1076			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1077			m->m_pkthdr.rcvif = (struct ifnet *)0;
1078			ip6f->ip6f_reserved = 0;
1079			ip6f->ip6f_ident = id;
1080			ip6f->ip6f_nxt = nextproto;
1081			ip6stat.ip6s_ofragments++;
1082			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1083		}
1084
1085		in6_ifstat_inc(ifp, ifs6_out_fragok);
1086	}
1087
1088	/*
1089	 * Remove leading garbages.
1090	 */
1091sendorfree:
1092	m = m0->m_nextpkt;
1093	m0->m_nextpkt = 0;
1094	m_freem(m0);
1095	for (m0 = m; m; m = m0) {
1096		m0 = m->m_nextpkt;
1097		m->m_nextpkt = 0;
1098		if (error == 0) {
1099 			/* Record statistics for this interface address. */
1100 			if (ia) {
1101 				ia->ia_ifa.if_opackets++;
1102 				ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1103 			}
1104#ifdef IPSEC
1105			/* clean ipsec history once it goes out of the node */
1106			ipsec_delaux(m);
1107#endif
1108			error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1109		} else
1110			m_freem(m);
1111	}
1112
1113	if (error == 0)
1114		ip6stat.ip6s_fragmented++;
1115
1116done:
1117	if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
1118		RTFREE(ro->ro_rt);
1119	} else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
1120		RTFREE(ro_pmtu->ro_rt);
1121	}
1122
1123#ifdef IPSEC
1124	if (sp != NULL)
1125		key_freesp(sp);
1126#endif /* IPSEC */
1127#ifdef FAST_IPSEC
1128	if (sp != NULL)
1129		KEY_FREESP(&sp);
1130#endif /* FAST_IPSEC */
1131
1132	return(error);
1133
1134freehdrs:
1135	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
1136	m_freem(exthdrs.ip6e_dest1);
1137	m_freem(exthdrs.ip6e_rthdr);
1138	m_freem(exthdrs.ip6e_dest2);
1139	/* fall through */
1140bad:
1141	m_freem(m);
1142	goto done;
1143}
1144
1145static int
1146ip6_copyexthdr(mp, hdr, hlen)
1147	struct mbuf **mp;
1148	caddr_t hdr;
1149	int hlen;
1150{
1151	struct mbuf *m;
1152
1153	if (hlen > MCLBYTES)
1154		return(ENOBUFS); /* XXX */
1155
1156	MGET(m, M_DONTWAIT, MT_DATA);
1157	if (!m)
1158		return(ENOBUFS);
1159
1160	if (hlen > MLEN) {
1161		MCLGET(m, M_DONTWAIT);
1162		if ((m->m_flags & M_EXT) == 0) {
1163			m_free(m);
1164			return(ENOBUFS);
1165		}
1166	}
1167	m->m_len = hlen;
1168	if (hdr)
1169		bcopy(hdr, mtod(m, caddr_t), hlen);
1170
1171	*mp = m;
1172	return(0);
1173}
1174
1175/*
1176 * Insert jumbo payload option.
1177 */
1178static int
1179ip6_insert_jumboopt(exthdrs, plen)
1180	struct ip6_exthdrs *exthdrs;
1181	u_int32_t plen;
1182{
1183	struct mbuf *mopt;
1184	u_char *optbuf;
1185	u_int32_t v;
1186
1187#define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1188
1189	/*
1190	 * If there is no hop-by-hop options header, allocate new one.
1191	 * If there is one but it doesn't have enough space to store the
1192	 * jumbo payload option, allocate a cluster to store the whole options.
1193	 * Otherwise, use it to store the options.
1194	 */
1195	if (exthdrs->ip6e_hbh == 0) {
1196		MGET(mopt, M_DONTWAIT, MT_DATA);
1197		if (mopt == 0)
1198			return(ENOBUFS);
1199		mopt->m_len = JUMBOOPTLEN;
1200		optbuf = mtod(mopt, u_char *);
1201		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1202		exthdrs->ip6e_hbh = mopt;
1203	} else {
1204		struct ip6_hbh *hbh;
1205
1206		mopt = exthdrs->ip6e_hbh;
1207		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1208			/*
1209			 * XXX assumption:
1210			 * - exthdrs->ip6e_hbh is not referenced from places
1211			 *   other than exthdrs.
1212			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1213			 */
1214			int oldoptlen = mopt->m_len;
1215			struct mbuf *n;
1216
1217			/*
1218			 * XXX: give up if the whole (new) hbh header does
1219			 * not fit even in an mbuf cluster.
1220			 */
1221			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1222				return(ENOBUFS);
1223
1224			/*
1225			 * As a consequence, we must always prepare a cluster
1226			 * at this point.
1227			 */
1228			MGET(n, M_DONTWAIT, MT_DATA);
1229			if (n) {
1230				MCLGET(n, M_DONTWAIT);
1231				if ((n->m_flags & M_EXT) == 0) {
1232					m_freem(n);
1233					n = NULL;
1234				}
1235			}
1236			if (!n)
1237				return(ENOBUFS);
1238			n->m_len = oldoptlen + JUMBOOPTLEN;
1239			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1240			      oldoptlen);
1241			optbuf = mtod(n, caddr_t) + oldoptlen;
1242			m_freem(mopt);
1243			mopt = exthdrs->ip6e_hbh = n;
1244		} else {
1245			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1246			mopt->m_len += JUMBOOPTLEN;
1247		}
1248		optbuf[0] = IP6OPT_PADN;
1249		optbuf[1] = 1;
1250
1251		/*
1252		 * Adjust the header length according to the pad and
1253		 * the jumbo payload option.
1254		 */
1255		hbh = mtod(mopt, struct ip6_hbh *);
1256		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1257	}
1258
1259	/* fill in the option. */
1260	optbuf[2] = IP6OPT_JUMBO;
1261	optbuf[3] = 4;
1262	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1263	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1264
1265	/* finally, adjust the packet header length */
1266	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1267
1268	return(0);
1269#undef JUMBOOPTLEN
1270}
1271
1272/*
1273 * Insert fragment header and copy unfragmentable header portions.
1274 */
1275static int
1276ip6_insertfraghdr(m0, m, hlen, frghdrp)
1277	struct mbuf *m0, *m;
1278	int hlen;
1279	struct ip6_frag **frghdrp;
1280{
1281	struct mbuf *n, *mlast;
1282
1283	if (hlen > sizeof(struct ip6_hdr)) {
1284		n = m_copym(m0, sizeof(struct ip6_hdr),
1285			    hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
1286		if (n == 0)
1287			return(ENOBUFS);
1288		m->m_next = n;
1289	} else
1290		n = m;
1291
1292	/* Search for the last mbuf of unfragmentable part. */
1293	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1294		;
1295
1296	if ((mlast->m_flags & M_EXT) == 0 &&
1297	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1298		/* use the trailing space of the last mbuf for the fragment hdr */
1299		*frghdrp =
1300			(struct ip6_frag *)(mtod(mlast, caddr_t) + mlast->m_len);
1301		mlast->m_len += sizeof(struct ip6_frag);
1302		m->m_pkthdr.len += sizeof(struct ip6_frag);
1303	} else {
1304		/* allocate a new mbuf for the fragment header */
1305		struct mbuf *mfrg;
1306
1307		MGET(mfrg, M_DONTWAIT, MT_DATA);
1308		if (mfrg == 0)
1309			return(ENOBUFS);
1310		mfrg->m_len = sizeof(struct ip6_frag);
1311		*frghdrp = mtod(mfrg, struct ip6_frag *);
1312		mlast->m_next = mfrg;
1313	}
1314
1315	return(0);
1316}
1317
1318/*
1319 * IP6 socket option processing.
1320 */
1321int
1322ip6_ctloutput(so, sopt)
1323	struct socket *so;
1324	struct sockopt *sopt;
1325{
1326	int privileged;
1327	struct inpcb *in6p = sotoinpcb(so);
1328	int error, optval;
1329	int level, op, optname;
1330	int optlen;
1331	struct thread *td;
1332
1333	if (sopt) {
1334		level = sopt->sopt_level;
1335		op = sopt->sopt_dir;
1336		optname = sopt->sopt_name;
1337		optlen = sopt->sopt_valsize;
1338		td = sopt->sopt_td;
1339	} else {
1340		panic("ip6_ctloutput: arg soopt is NULL");
1341	}
1342	error = optval = 0;
1343
1344	privileged = (td == 0 || suser(td)) ? 0 : 1;
1345
1346	if (level == IPPROTO_IPV6) {
1347		switch (op) {
1348
1349		case SOPT_SET:
1350			switch (optname) {
1351			case IPV6_PKTOPTIONS:
1352			{
1353				struct mbuf *m;
1354
1355				error = soopt_getm(sopt, &m); /* XXX */
1356				if (error != 0)
1357					break;
1358				error = soopt_mcopyin(sopt, m); /* XXX */
1359				if (error != 0)
1360					break;
1361				error = ip6_pcbopts(&in6p->in6p_outputopts,
1362						    m, so, sopt);
1363				m_freem(m); /* XXX */
1364				break;
1365			}
1366
1367			/*
1368			 * Use of some Hop-by-Hop options or some
1369			 * Destination options, might require special
1370			 * privilege.  That is, normal applications
1371			 * (without special privilege) might be forbidden
1372			 * from setting certain options in outgoing packets,
1373			 * and might never see certain options in received
1374			 * packets. [RFC 2292 Section 6]
1375			 * KAME specific note:
1376			 *  KAME prevents non-privileged users from sending or
1377			 *  receiving ANY hbh/dst options in order to avoid
1378			 *  overhead of parsing options in the kernel.
1379			 */
1380			case IPV6_UNICAST_HOPS:
1381			case IPV6_CHECKSUM:
1382			case IPV6_FAITH:
1383
1384			case IPV6_V6ONLY:
1385				if (optlen != sizeof(int)) {
1386					error = EINVAL;
1387					break;
1388				}
1389				error = sooptcopyin(sopt, &optval,
1390					sizeof optval, sizeof optval);
1391				if (error)
1392					break;
1393				switch (optname) {
1394
1395				case IPV6_UNICAST_HOPS:
1396					if (optval < -1 || optval >= 256)
1397						error = EINVAL;
1398					else {
1399						/* -1 = kernel default */
1400						in6p->in6p_hops = optval;
1401
1402						if ((in6p->in6p_vflag &
1403						     INP_IPV4) != 0)
1404							in6p->inp_ip_ttl = optval;
1405					}
1406					break;
1407#define OPTSET(bit) \
1408do { \
1409	if (optval) \
1410		in6p->in6p_flags |= (bit); \
1411	else \
1412		in6p->in6p_flags &= ~(bit); \
1413} while (0)
1414#define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
1415
1416				case IPV6_CHECKSUM:
1417					in6p->in6p_cksum = optval;
1418					break;
1419
1420				case IPV6_FAITH:
1421					OPTSET(IN6P_FAITH);
1422					break;
1423
1424				case IPV6_V6ONLY:
1425					/*
1426					 * make setsockopt(IPV6_V6ONLY)
1427					 * available only prior to bind(2).
1428					 * see ipng mailing list, Jun 22 2001.
1429					 */
1430					if (in6p->in6p_lport ||
1431					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr))
1432					{
1433						error = EINVAL;
1434						break;
1435					}
1436					OPTSET(IN6P_IPV6_V6ONLY);
1437					if (optval)
1438						in6p->in6p_vflag &= ~INP_IPV4;
1439					else
1440						in6p->in6p_vflag |= INP_IPV4;
1441					break;
1442				}
1443				break;
1444
1445			case IPV6_PKTINFO:
1446			case IPV6_HOPLIMIT:
1447			case IPV6_HOPOPTS:
1448			case IPV6_DSTOPTS:
1449			case IPV6_RTHDR:
1450				/* RFC 2292 */
1451				if (optlen != sizeof(int)) {
1452					error = EINVAL;
1453					break;
1454				}
1455				error = sooptcopyin(sopt, &optval,
1456					sizeof optval, sizeof optval);
1457				if (error)
1458					break;
1459				switch (optname) {
1460				case IPV6_PKTINFO:
1461					OPTSET(IN6P_PKTINFO);
1462					break;
1463				case IPV6_HOPLIMIT:
1464					OPTSET(IN6P_HOPLIMIT);
1465					break;
1466				case IPV6_HOPOPTS:
1467					/*
1468					 * Check super-user privilege.
1469					 * See comments for IPV6_RECVHOPOPTS.
1470					 */
1471					if (!privileged)
1472						return(EPERM);
1473					OPTSET(IN6P_HOPOPTS);
1474					break;
1475				case IPV6_DSTOPTS:
1476					if (!privileged)
1477						return(EPERM);
1478					OPTSET(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1479					break;
1480				case IPV6_RTHDR:
1481					OPTSET(IN6P_RTHDR);
1482					break;
1483				}
1484				break;
1485#undef OPTSET
1486
1487			case IPV6_MULTICAST_IF:
1488			case IPV6_MULTICAST_HOPS:
1489			case IPV6_MULTICAST_LOOP:
1490			case IPV6_JOIN_GROUP:
1491			case IPV6_LEAVE_GROUP:
1492			    {
1493				struct mbuf *m;
1494				if (sopt->sopt_valsize > MLEN) {
1495					error = EMSGSIZE;
1496					break;
1497				}
1498				/* XXX */
1499				MGET(m, sopt->sopt_td ? M_TRYWAIT : M_DONTWAIT, MT_HEADER);
1500				if (m == 0) {
1501					error = ENOBUFS;
1502					break;
1503				}
1504				m->m_len = sopt->sopt_valsize;
1505				error = sooptcopyin(sopt, mtod(m, char *),
1506						    m->m_len, m->m_len);
1507				error =	ip6_setmoptions(sopt->sopt_name,
1508							&in6p->in6p_moptions,
1509							m);
1510				(void)m_free(m);
1511			    }
1512				break;
1513
1514			case IPV6_PORTRANGE:
1515				error = sooptcopyin(sopt, &optval,
1516				    sizeof optval, sizeof optval);
1517				if (error)
1518					break;
1519
1520				switch (optval) {
1521				case IPV6_PORTRANGE_DEFAULT:
1522					in6p->in6p_flags &= ~(IN6P_LOWPORT);
1523					in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1524					break;
1525
1526				case IPV6_PORTRANGE_HIGH:
1527					in6p->in6p_flags &= ~(IN6P_LOWPORT);
1528					in6p->in6p_flags |= IN6P_HIGHPORT;
1529					break;
1530
1531				case IPV6_PORTRANGE_LOW:
1532					in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1533					in6p->in6p_flags |= IN6P_LOWPORT;
1534					break;
1535
1536				default:
1537					error = EINVAL;
1538					break;
1539				}
1540				break;
1541
1542#if defined(IPSEC) || defined(FAST_IPSEC)
1543			case IPV6_IPSEC_POLICY:
1544			    {
1545				caddr_t req = NULL;
1546				size_t len = 0;
1547				struct mbuf *m;
1548
1549				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1550					break;
1551				if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1552					break;
1553				if (m) {
1554					req = mtod(m, caddr_t);
1555					len = m->m_len;
1556				}
1557				error = ipsec6_set_policy(in6p, optname, req,
1558				                          len, privileged);
1559				m_freem(m);
1560			    }
1561				break;
1562#endif /* KAME IPSEC */
1563
1564			case IPV6_FW_ADD:
1565			case IPV6_FW_DEL:
1566			case IPV6_FW_FLUSH:
1567			case IPV6_FW_ZERO:
1568			    {
1569				struct mbuf *m;
1570				struct mbuf **mp = &m;
1571
1572				if (ip6_fw_ctl_ptr == NULL)
1573					return EINVAL;
1574				/* XXX */
1575				if ((error = soopt_getm(sopt, &m)) != 0)
1576					break;
1577				/* XXX */
1578				if ((error = soopt_mcopyin(sopt, m)) != 0)
1579					break;
1580				error = (*ip6_fw_ctl_ptr)(optname, mp);
1581				m = *mp;
1582			    }
1583				break;
1584
1585			default:
1586				error = ENOPROTOOPT;
1587				break;
1588			}
1589			break;
1590
1591		case SOPT_GET:
1592			switch (optname) {
1593
1594			case IPV6_PKTOPTIONS:
1595				if (in6p->in6p_options) {
1596					struct mbuf *m;
1597					m = m_copym(in6p->in6p_options,
1598					    0, M_COPYALL, M_TRYWAIT);
1599					error = soopt_mcopyout(sopt, m);
1600					if (error == 0)
1601						m_freem(m);
1602				} else
1603					sopt->sopt_valsize = 0;
1604				break;
1605
1606			case IPV6_UNICAST_HOPS:
1607			case IPV6_CHECKSUM:
1608
1609			case IPV6_FAITH:
1610			case IPV6_V6ONLY:
1611			case IPV6_PORTRANGE:
1612				switch (optname) {
1613
1614				case IPV6_UNICAST_HOPS:
1615					optval = in6p->in6p_hops;
1616					break;
1617
1618				case IPV6_CHECKSUM:
1619					optval = in6p->in6p_cksum;
1620					break;
1621
1622				case IPV6_FAITH:
1623					optval = OPTBIT(IN6P_FAITH);
1624					break;
1625
1626				case IPV6_V6ONLY:
1627					optval = OPTBIT(IN6P_IPV6_V6ONLY);
1628					break;
1629
1630				case IPV6_PORTRANGE:
1631				    {
1632					int flags;
1633					flags = in6p->in6p_flags;
1634					if (flags & IN6P_HIGHPORT)
1635						optval = IPV6_PORTRANGE_HIGH;
1636					else if (flags & IN6P_LOWPORT)
1637						optval = IPV6_PORTRANGE_LOW;
1638					else
1639						optval = 0;
1640					break;
1641				    }
1642				}
1643				error = sooptcopyout(sopt, &optval,
1644					sizeof optval);
1645				break;
1646
1647			case IPV6_PKTINFO:
1648			case IPV6_HOPLIMIT:
1649			case IPV6_HOPOPTS:
1650			case IPV6_RTHDR:
1651			case IPV6_DSTOPTS:
1652				if (optname == IPV6_HOPOPTS ||
1653				    optname == IPV6_DSTOPTS ||
1654				    !privileged)
1655					return(EPERM);
1656				switch (optname) {
1657				case IPV6_PKTINFO:
1658					optval = OPTBIT(IN6P_PKTINFO);
1659					break;
1660				case IPV6_HOPLIMIT:
1661					optval = OPTBIT(IN6P_HOPLIMIT);
1662					break;
1663				case IPV6_HOPOPTS:
1664					if (!privileged)
1665						return(EPERM);
1666					optval = OPTBIT(IN6P_HOPOPTS);
1667					break;
1668				case IPV6_RTHDR:
1669					optval = OPTBIT(IN6P_RTHDR);
1670					break;
1671				case IPV6_DSTOPTS:
1672					if (!privileged)
1673						return(EPERM);
1674					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1675					break;
1676				}
1677				error = sooptcopyout(sopt, &optval,
1678					sizeof optval);
1679				break;
1680
1681			case IPV6_MULTICAST_IF:
1682			case IPV6_MULTICAST_HOPS:
1683			case IPV6_MULTICAST_LOOP:
1684			case IPV6_JOIN_GROUP:
1685			case IPV6_LEAVE_GROUP:
1686			    {
1687				struct mbuf *m;
1688				error = ip6_getmoptions(sopt->sopt_name,
1689						in6p->in6p_moptions, &m);
1690				if (error == 0)
1691					error = sooptcopyout(sopt,
1692						mtod(m, char *), m->m_len);
1693				m_freem(m);
1694			    }
1695				break;
1696
1697#if defined(IPSEC) || defined(FAST_IPSEC)
1698			case IPV6_IPSEC_POLICY:
1699			  {
1700				caddr_t req = NULL;
1701				size_t len = 0;
1702				struct mbuf *m = NULL;
1703				struct mbuf **mp = &m;
1704
1705				error = soopt_getm(sopt, &m); /* XXX */
1706				if (error != 0)
1707					break;
1708				error = soopt_mcopyin(sopt, m); /* XXX */
1709				if (error != 0)
1710					break;
1711				if (m) {
1712					req = mtod(m, caddr_t);
1713					len = m->m_len;
1714				}
1715				error = ipsec6_get_policy(in6p, req, len, mp);
1716				if (error == 0)
1717					error = soopt_mcopyout(sopt, m); /*XXX*/
1718				if (error == 0 && m)
1719					m_freem(m);
1720				break;
1721			  }
1722#endif /* KAME IPSEC */
1723
1724			case IPV6_FW_GET:
1725			  {
1726				struct mbuf *m;
1727				struct mbuf **mp = &m;
1728
1729				if (ip6_fw_ctl_ptr == NULL)
1730			        {
1731					return EINVAL;
1732				}
1733				error = (*ip6_fw_ctl_ptr)(optname, mp);
1734				if (error == 0)
1735					error = soopt_mcopyout(sopt, m); /* XXX */
1736				if (error == 0 && m)
1737					m_freem(m);
1738			  }
1739				break;
1740
1741			default:
1742				error = ENOPROTOOPT;
1743				break;
1744			}
1745			break;
1746		}
1747	} else {
1748		error = EINVAL;
1749	}
1750	return(error);
1751}
1752
1753/*
1754 * Set up IP6 options in pcb for insertion in output packets or
1755 * specifying behavior of outgoing packets.
1756 */
1757static int
1758ip6_pcbopts(pktopt, m, so, sopt)
1759	struct ip6_pktopts **pktopt;
1760	struct mbuf *m;
1761	struct socket *so;
1762	struct sockopt *sopt;
1763{
1764	struct ip6_pktopts *opt = *pktopt;
1765	int error = 0;
1766	struct thread *td = sopt->sopt_td;
1767	int priv = 0;
1768
1769	/* turn off any old options. */
1770	if (opt) {
1771#ifdef DIAGNOSTIC
1772		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
1773		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
1774		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
1775			printf("ip6_pcbopts: all specified options are cleared.\n");
1776#endif
1777		ip6_clearpktopts(opt, 1, -1);
1778	} else
1779		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
1780	*pktopt = NULL;
1781
1782	if (!m || m->m_len == 0) {
1783		/*
1784		 * Only turning off any previous options, regardless of
1785		 * whether the opt is just created or given.
1786		 */
1787		free(opt, M_IP6OPT);
1788		return(0);
1789	}
1790
1791	/*  set options specified by user. */
1792	if (td && !suser(td))
1793		priv = 1;
1794	if ((error = ip6_setpktoptions(m, opt, priv, 1)) != 0) {
1795		ip6_clearpktopts(opt, 1, -1); /* XXX: discard all options */
1796		free(opt, M_IP6OPT);
1797		return(error);
1798	}
1799	*pktopt = opt;
1800	return(0);
1801}
1802
1803/*
1804 * initialize ip6_pktopts.  beware that there are non-zero default values in
1805 * the struct.
1806 */
1807void
1808init_ip6pktopts(opt)
1809	struct ip6_pktopts *opt;
1810{
1811
1812	bzero(opt, sizeof(*opt));
1813	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
1814}
1815
1816void
1817ip6_clearpktopts(pktopt, needfree, optname)
1818	struct ip6_pktopts *pktopt;
1819	int needfree, optname;
1820{
1821	if (pktopt == NULL)
1822		return;
1823
1824	if (optname == -1) {
1825		if (needfree && pktopt->ip6po_pktinfo)
1826			free(pktopt->ip6po_pktinfo, M_IP6OPT);
1827		pktopt->ip6po_pktinfo = NULL;
1828	}
1829	if (optname == -1)
1830		pktopt->ip6po_hlim = -1;
1831	if (optname == -1) {
1832		if (needfree && pktopt->ip6po_nexthop)
1833			free(pktopt->ip6po_nexthop, M_IP6OPT);
1834		pktopt->ip6po_nexthop = NULL;
1835	}
1836	if (optname == -1) {
1837		if (needfree && pktopt->ip6po_hbh)
1838			free(pktopt->ip6po_hbh, M_IP6OPT);
1839		pktopt->ip6po_hbh = NULL;
1840	}
1841	if (optname == -1) {
1842		if (needfree && pktopt->ip6po_dest1)
1843			free(pktopt->ip6po_dest1, M_IP6OPT);
1844		pktopt->ip6po_dest1 = NULL;
1845	}
1846	if (optname == -1) {
1847		if (needfree && pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
1848			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
1849		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
1850		if (pktopt->ip6po_route.ro_rt) {
1851			RTFREE(pktopt->ip6po_route.ro_rt);
1852			pktopt->ip6po_route.ro_rt = NULL;
1853		}
1854	}
1855	if (optname == -1) {
1856		if (needfree && pktopt->ip6po_dest2)
1857			free(pktopt->ip6po_dest2, M_IP6OPT);
1858		pktopt->ip6po_dest2 = NULL;
1859	}
1860}
1861
1862#define PKTOPT_EXTHDRCPY(type) \
1863do {\
1864	if (src->type) {\
1865		int hlen =\
1866			(((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
1867		dst->type = malloc(hlen, M_IP6OPT, canwait);\
1868		if (dst->type == NULL && canwait == M_NOWAIT)\
1869			goto bad;\
1870		bcopy(src->type, dst->type, hlen);\
1871	}\
1872} while (0)
1873
1874struct ip6_pktopts *
1875ip6_copypktopts(src, canwait)
1876	struct ip6_pktopts *src;
1877	int canwait;
1878{
1879	struct ip6_pktopts *dst;
1880
1881	if (src == NULL) {
1882		printf("ip6_clearpktopts: invalid argument\n");
1883		return(NULL);
1884	}
1885
1886	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
1887	if (dst == NULL && canwait == M_NOWAIT)
1888		return (NULL);
1889	bzero(dst, sizeof(*dst));
1890
1891	dst->ip6po_hlim = src->ip6po_hlim;
1892	if (src->ip6po_pktinfo) {
1893		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
1894					    M_IP6OPT, canwait);
1895		if (dst->ip6po_pktinfo == NULL && canwait == M_NOWAIT)
1896			goto bad;
1897		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
1898	}
1899	if (src->ip6po_nexthop) {
1900		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
1901					    M_IP6OPT, canwait);
1902		if (dst->ip6po_nexthop == NULL && canwait == M_NOWAIT)
1903			goto bad;
1904		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
1905		      src->ip6po_nexthop->sa_len);
1906	}
1907	PKTOPT_EXTHDRCPY(ip6po_hbh);
1908	PKTOPT_EXTHDRCPY(ip6po_dest1);
1909	PKTOPT_EXTHDRCPY(ip6po_dest2);
1910	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
1911	return(dst);
1912
1913  bad:
1914	if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
1915	if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
1916	if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
1917	if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
1918	if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
1919	if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
1920	free(dst, M_IP6OPT);
1921	return(NULL);
1922}
1923#undef PKTOPT_EXTHDRCPY
1924
1925void
1926ip6_freepcbopts(pktopt)
1927	struct ip6_pktopts *pktopt;
1928{
1929	if (pktopt == NULL)
1930		return;
1931
1932	ip6_clearpktopts(pktopt, 1, -1);
1933
1934	free(pktopt, M_IP6OPT);
1935}
1936
1937/*
1938 * Set the IP6 multicast options in response to user setsockopt().
1939 */
1940static int
1941ip6_setmoptions(optname, im6op, m)
1942	int optname;
1943	struct ip6_moptions **im6op;
1944	struct mbuf *m;
1945{
1946	int error = 0;
1947	u_int loop, ifindex;
1948	struct ipv6_mreq *mreq;
1949	struct ifnet *ifp;
1950	struct ip6_moptions *im6o = *im6op;
1951	struct route_in6 ro;
1952	struct sockaddr_in6 *dst;
1953	struct in6_multi_mship *imm;
1954	struct thread *td = curthread;	/* XXX */
1955
1956	if (im6o == NULL) {
1957		/*
1958		 * No multicast option buffer attached to the pcb;
1959		 * allocate one and initialize to default values.
1960		 */
1961		im6o = (struct ip6_moptions *)
1962			malloc(sizeof(*im6o), M_IPMOPTS, M_WAITOK);
1963
1964		if (im6o == NULL)
1965			return(ENOBUFS);
1966		*im6op = im6o;
1967		im6o->im6o_multicast_ifp = NULL;
1968		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
1969		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
1970		LIST_INIT(&im6o->im6o_memberships);
1971	}
1972
1973	switch (optname) {
1974
1975	case IPV6_MULTICAST_IF:
1976		/*
1977		 * Select the interface for outgoing multicast packets.
1978		 */
1979		if (m == NULL || m->m_len != sizeof(u_int)) {
1980			error = EINVAL;
1981			break;
1982		}
1983		bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
1984		if (ifindex < 0 || if_index < ifindex) {
1985			error = ENXIO;	/* XXX EINVAL? */
1986			break;
1987		}
1988		ifp = ifnet_byindex(ifindex);
1989		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
1990			error = EADDRNOTAVAIL;
1991			break;
1992		}
1993		im6o->im6o_multicast_ifp = ifp;
1994		break;
1995
1996	case IPV6_MULTICAST_HOPS:
1997	    {
1998		/*
1999		 * Set the IP6 hoplimit for outgoing multicast packets.
2000		 */
2001		int optval;
2002		if (m == NULL || m->m_len != sizeof(int)) {
2003			error = EINVAL;
2004			break;
2005		}
2006		bcopy(mtod(m, u_int *), &optval, sizeof(optval));
2007		if (optval < -1 || optval >= 256)
2008			error = EINVAL;
2009		else if (optval == -1)
2010			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2011		else
2012			im6o->im6o_multicast_hlim = optval;
2013		break;
2014	    }
2015
2016	case IPV6_MULTICAST_LOOP:
2017		/*
2018		 * Set the loopback flag for outgoing multicast packets.
2019		 * Must be zero or one.
2020		 */
2021		if (m == NULL || m->m_len != sizeof(u_int)) {
2022			error = EINVAL;
2023			break;
2024		}
2025		bcopy(mtod(m, u_int *), &loop, sizeof(loop));
2026		if (loop > 1) {
2027			error = EINVAL;
2028			break;
2029		}
2030		im6o->im6o_multicast_loop = loop;
2031		break;
2032
2033	case IPV6_JOIN_GROUP:
2034		/*
2035		 * Add a multicast group membership.
2036		 * Group must be a valid IP6 multicast address.
2037		 */
2038		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2039			error = EINVAL;
2040			break;
2041		}
2042		mreq = mtod(m, struct ipv6_mreq *);
2043		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2044			/*
2045			 * We use the unspecified address to specify to accept
2046			 * all multicast addresses. Only super user is allowed
2047			 * to do this.
2048			 */
2049			if (suser(td))
2050			{
2051				error = EACCES;
2052				break;
2053			}
2054		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2055			error = EINVAL;
2056			break;
2057		}
2058
2059		/*
2060		 * If the interface is specified, validate it.
2061		 */
2062		if (mreq->ipv6mr_interface < 0
2063		 || if_index < mreq->ipv6mr_interface) {
2064			error = ENXIO;	/* XXX EINVAL? */
2065			break;
2066		}
2067		/*
2068		 * If no interface was explicitly specified, choose an
2069		 * appropriate one according to the given multicast address.
2070		 */
2071		if (mreq->ipv6mr_interface == 0) {
2072			/*
2073			 * If the multicast address is in node-local scope,
2074			 * the interface should be a loopback interface.
2075			 * Otherwise, look up the routing table for the
2076			 * address, and choose the outgoing interface.
2077			 *   XXX: is it a good approach?
2078			 */
2079			if (IN6_IS_ADDR_MC_NODELOCAL(&mreq->ipv6mr_multiaddr)) {
2080				ifp = &loif[0];
2081			} else {
2082				ro.ro_rt = NULL;
2083				dst = (struct sockaddr_in6 *)&ro.ro_dst;
2084				bzero(dst, sizeof(*dst));
2085				dst->sin6_len = sizeof(struct sockaddr_in6);
2086				dst->sin6_family = AF_INET6;
2087				dst->sin6_addr = mreq->ipv6mr_multiaddr;
2088				rtalloc((struct route *)&ro);
2089				if (ro.ro_rt == NULL) {
2090					error = EADDRNOTAVAIL;
2091					break;
2092				}
2093				ifp = ro.ro_rt->rt_ifp;
2094				rtfree(ro.ro_rt);
2095			}
2096		} else
2097			ifp = ifnet_byindex(mreq->ipv6mr_interface);
2098
2099		/*
2100		 * See if we found an interface, and confirm that it
2101		 * supports multicast
2102		 */
2103		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
2104			error = EADDRNOTAVAIL;
2105			break;
2106		}
2107		/*
2108		 * Put interface index into the multicast address,
2109		 * if the address has link-local scope.
2110		 */
2111		if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
2112			mreq->ipv6mr_multiaddr.s6_addr16[1]
2113				= htons(mreq->ipv6mr_interface);
2114		}
2115		/*
2116		 * See if the membership already exists.
2117		 */
2118		for (imm = im6o->im6o_memberships.lh_first;
2119		     imm != NULL; imm = imm->i6mm_chain.le_next)
2120			if (imm->i6mm_maddr->in6m_ifp == ifp &&
2121			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2122					       &mreq->ipv6mr_multiaddr))
2123				break;
2124		if (imm != NULL) {
2125			error = EADDRINUSE;
2126			break;
2127		}
2128		/*
2129		 * Everything looks good; add a new record to the multicast
2130		 * address list for the given interface.
2131		 */
2132		imm = malloc(sizeof(*imm), M_IPMADDR, M_WAITOK);
2133		if (imm == NULL) {
2134			error = ENOBUFS;
2135			break;
2136		}
2137		if ((imm->i6mm_maddr =
2138		     in6_addmulti(&mreq->ipv6mr_multiaddr, ifp, &error)) == NULL) {
2139			free(imm, M_IPMADDR);
2140			break;
2141		}
2142		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
2143		break;
2144
2145	case IPV6_LEAVE_GROUP:
2146		/*
2147		 * Drop a multicast group membership.
2148		 * Group must be a valid IP6 multicast address.
2149		 */
2150		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2151			error = EINVAL;
2152			break;
2153		}
2154		mreq = mtod(m, struct ipv6_mreq *);
2155		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2156			if (suser(td)) {
2157				error = EACCES;
2158				break;
2159			}
2160		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2161			error = EINVAL;
2162			break;
2163		}
2164		/*
2165		 * If an interface address was specified, get a pointer
2166		 * to its ifnet structure.
2167		 */
2168		if (mreq->ipv6mr_interface < 0
2169		 || if_index < mreq->ipv6mr_interface) {
2170			error = ENXIO;	/* XXX EINVAL? */
2171			break;
2172		}
2173		ifp = ifnet_byindex(mreq->ipv6mr_interface);
2174		/*
2175		 * Put interface index into the multicast address,
2176		 * if the address has link-local scope.
2177		 */
2178		if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
2179			mreq->ipv6mr_multiaddr.s6_addr16[1]
2180				= htons(mreq->ipv6mr_interface);
2181		}
2182		/*
2183		 * Find the membership in the membership list.
2184		 */
2185		for (imm = im6o->im6o_memberships.lh_first;
2186		     imm != NULL; imm = imm->i6mm_chain.le_next) {
2187			if ((ifp == NULL ||
2188			     imm->i6mm_maddr->in6m_ifp == ifp) &&
2189			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2190					       &mreq->ipv6mr_multiaddr))
2191				break;
2192		}
2193		if (imm == NULL) {
2194			/* Unable to resolve interface */
2195			error = EADDRNOTAVAIL;
2196			break;
2197		}
2198		/*
2199		 * Give up the multicast address record to which the
2200		 * membership points.
2201		 */
2202		LIST_REMOVE(imm, i6mm_chain);
2203		in6_delmulti(imm->i6mm_maddr);
2204		free(imm, M_IPMADDR);
2205		break;
2206
2207	default:
2208		error = EOPNOTSUPP;
2209		break;
2210	}
2211
2212	/*
2213	 * If all options have default values, no need to keep the mbuf.
2214	 */
2215	if (im6o->im6o_multicast_ifp == NULL &&
2216	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
2217	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
2218	    im6o->im6o_memberships.lh_first == NULL) {
2219		free(*im6op, M_IPMOPTS);
2220		*im6op = NULL;
2221	}
2222
2223	return(error);
2224}
2225
2226/*
2227 * Return the IP6 multicast options in response to user getsockopt().
2228 */
2229static int
2230ip6_getmoptions(optname, im6o, mp)
2231	int optname;
2232	struct ip6_moptions *im6o;
2233	struct mbuf **mp;
2234{
2235	u_int *hlim, *loop, *ifindex;
2236
2237	*mp = m_get(M_TRYWAIT, MT_HEADER);		/* XXX */
2238
2239	switch (optname) {
2240
2241	case IPV6_MULTICAST_IF:
2242		ifindex = mtod(*mp, u_int *);
2243		(*mp)->m_len = sizeof(u_int);
2244		if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
2245			*ifindex = 0;
2246		else
2247			*ifindex = im6o->im6o_multicast_ifp->if_index;
2248		return(0);
2249
2250	case IPV6_MULTICAST_HOPS:
2251		hlim = mtod(*mp, u_int *);
2252		(*mp)->m_len = sizeof(u_int);
2253		if (im6o == NULL)
2254			*hlim = ip6_defmcasthlim;
2255		else
2256			*hlim = im6o->im6o_multicast_hlim;
2257		return(0);
2258
2259	case IPV6_MULTICAST_LOOP:
2260		loop = mtod(*mp, u_int *);
2261		(*mp)->m_len = sizeof(u_int);
2262		if (im6o == NULL)
2263			*loop = ip6_defmcasthlim;
2264		else
2265			*loop = im6o->im6o_multicast_loop;
2266		return(0);
2267
2268	default:
2269		return(EOPNOTSUPP);
2270	}
2271}
2272
2273/*
2274 * Discard the IP6 multicast options.
2275 */
2276void
2277ip6_freemoptions(im6o)
2278	struct ip6_moptions *im6o;
2279{
2280	struct in6_multi_mship *imm;
2281
2282	if (im6o == NULL)
2283		return;
2284
2285	while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
2286		LIST_REMOVE(imm, i6mm_chain);
2287		if (imm->i6mm_maddr)
2288			in6_delmulti(imm->i6mm_maddr);
2289		free(imm, M_IPMADDR);
2290	}
2291	free(im6o, M_IPMOPTS);
2292}
2293
2294/*
2295 * Set IPv6 outgoing packet options based on advanced API.
2296 */
2297int
2298ip6_setpktoptions(control, opt, priv, needcopy)
2299	struct mbuf *control;
2300	struct ip6_pktopts *opt;
2301	int priv, needcopy;
2302{
2303	struct cmsghdr *cm = 0;
2304
2305	if (control == 0 || opt == 0)
2306		return(EINVAL);
2307
2308	init_ip6pktopts(opt);
2309
2310	/*
2311	 * XXX: Currently, we assume all the optional information is stored
2312	 * in a single mbuf.
2313	 */
2314	if (control->m_next)
2315		return(EINVAL);
2316
2317	for (; control->m_len; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2318		     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2319		cm = mtod(control, struct cmsghdr *);
2320		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2321			return(EINVAL);
2322		if (cm->cmsg_level != IPPROTO_IPV6)
2323			continue;
2324
2325		/*
2326		 * XXX should check if RFC2292 API is mixed with 2292bis API
2327		 */
2328		switch (cm->cmsg_type) {
2329		case IPV6_PKTINFO:
2330			if (cm->cmsg_len != CMSG_LEN(sizeof(struct in6_pktinfo)))
2331				return(EINVAL);
2332			if (needcopy) {
2333				/* XXX: Is it really WAITOK? */
2334				opt->ip6po_pktinfo =
2335					malloc(sizeof(struct in6_pktinfo),
2336					       M_IP6OPT, M_WAITOK);
2337				bcopy(CMSG_DATA(cm), opt->ip6po_pktinfo,
2338				    sizeof(struct in6_pktinfo));
2339			} else
2340				opt->ip6po_pktinfo =
2341					(struct in6_pktinfo *)CMSG_DATA(cm);
2342			if (opt->ip6po_pktinfo->ipi6_ifindex &&
2343			    IN6_IS_ADDR_LINKLOCAL(&opt->ip6po_pktinfo->ipi6_addr))
2344				opt->ip6po_pktinfo->ipi6_addr.s6_addr16[1] =
2345					htons(opt->ip6po_pktinfo->ipi6_ifindex);
2346
2347			if (opt->ip6po_pktinfo->ipi6_ifindex > if_index
2348			 || opt->ip6po_pktinfo->ipi6_ifindex < 0) {
2349				return(ENXIO);
2350			}
2351
2352			/*
2353			 * Check if the requested source address is indeed a
2354			 * unicast address assigned to the node, and can be
2355			 * used as the packet's source address.
2356			 */
2357			if (!IN6_IS_ADDR_UNSPECIFIED(&opt->ip6po_pktinfo->ipi6_addr)) {
2358				struct in6_ifaddr *ia6;
2359				struct sockaddr_in6 sin6;
2360
2361				bzero(&sin6, sizeof(sin6));
2362				sin6.sin6_len = sizeof(sin6);
2363				sin6.sin6_family = AF_INET6;
2364				sin6.sin6_addr =
2365					opt->ip6po_pktinfo->ipi6_addr;
2366				ia6 = (struct in6_ifaddr *)ifa_ifwithaddr(sin6tosa(&sin6));
2367				if (ia6 == NULL ||
2368				    (ia6->ia6_flags & (IN6_IFF_ANYCAST |
2369						       IN6_IFF_NOTREADY)) != 0)
2370					return(EADDRNOTAVAIL);
2371			}
2372			break;
2373
2374		case IPV6_HOPLIMIT:
2375			if (cm->cmsg_len != CMSG_LEN(sizeof(int)))
2376				return(EINVAL);
2377
2378			opt->ip6po_hlim = *(int *)CMSG_DATA(cm);
2379			if (opt->ip6po_hlim < -1 || opt->ip6po_hlim > 255)
2380				return(EINVAL);
2381			break;
2382
2383		case IPV6_NEXTHOP:
2384			if (!priv)
2385				return(EPERM);
2386
2387			if (cm->cmsg_len < sizeof(u_char) ||
2388			    /* check if cmsg_len is large enough for sa_len */
2389			    cm->cmsg_len < CMSG_LEN(*CMSG_DATA(cm)))
2390				return(EINVAL);
2391
2392			if (needcopy) {
2393				opt->ip6po_nexthop =
2394					malloc(*CMSG_DATA(cm),
2395					       M_IP6OPT, M_WAITOK);
2396				bcopy(CMSG_DATA(cm),
2397				      opt->ip6po_nexthop,
2398				      *CMSG_DATA(cm));
2399			} else
2400				opt->ip6po_nexthop =
2401					(struct sockaddr *)CMSG_DATA(cm);
2402			break;
2403
2404		case IPV6_HOPOPTS:
2405		{
2406			struct ip6_hbh *hbh;
2407			int hbhlen;
2408
2409			if (cm->cmsg_len < CMSG_LEN(sizeof(struct ip6_hbh)))
2410				return(EINVAL);
2411			hbh = (struct ip6_hbh *)CMSG_DATA(cm);
2412			hbhlen = (hbh->ip6h_len + 1) << 3;
2413			if (cm->cmsg_len != CMSG_LEN(hbhlen))
2414				return(EINVAL);
2415
2416			if (needcopy) {
2417				opt->ip6po_hbh =
2418					malloc(hbhlen, M_IP6OPT, M_WAITOK);
2419				bcopy(hbh, opt->ip6po_hbh, hbhlen);
2420			} else
2421				opt->ip6po_hbh = hbh;
2422			break;
2423		}
2424
2425		case IPV6_DSTOPTS:
2426		{
2427			struct ip6_dest *dest, **newdest;
2428			int destlen;
2429
2430			if (cm->cmsg_len < CMSG_LEN(sizeof(struct ip6_dest)))
2431				return(EINVAL);
2432			dest = (struct ip6_dest *)CMSG_DATA(cm);
2433			destlen = (dest->ip6d_len + 1) << 3;
2434			if (cm->cmsg_len != CMSG_LEN(destlen))
2435				return(EINVAL);
2436
2437			/*
2438			 * The old advacned API is ambiguous on this
2439			 * point. Our approach is to determine the
2440			 * position based according to the existence
2441			 * of a routing header. Note, however, that
2442			 * this depends on the order of the extension
2443			 * headers in the ancillary data; the 1st part
2444			 * of the destination options header must
2445			 * appear before the routing header in the
2446			 * ancillary data, too.
2447			 * RFC2292bis solved the ambiguity by
2448			 * introducing separate cmsg types.
2449			 */
2450			if (opt->ip6po_rthdr == NULL)
2451				newdest = &opt->ip6po_dest1;
2452			else
2453				newdest = &opt->ip6po_dest2;
2454
2455			if (needcopy) {
2456				*newdest = malloc(destlen, M_IP6OPT, M_WAITOK);
2457				bcopy(dest, *newdest, destlen);
2458			} else
2459				*newdest = dest;
2460
2461			break;
2462		}
2463
2464		case IPV6_RTHDR:
2465		{
2466			struct ip6_rthdr *rth;
2467			int rthlen;
2468
2469			if (cm->cmsg_len < CMSG_LEN(sizeof(struct ip6_rthdr)))
2470				return(EINVAL);
2471			rth = (struct ip6_rthdr *)CMSG_DATA(cm);
2472			rthlen = (rth->ip6r_len + 1) << 3;
2473			if (cm->cmsg_len != CMSG_LEN(rthlen))
2474				return(EINVAL);
2475
2476			switch (rth->ip6r_type) {
2477			case IPV6_RTHDR_TYPE_0:
2478				/* must contain one addr */
2479				if (rth->ip6r_len == 0)
2480					return(EINVAL);
2481				/* length must be even */
2482				if (rth->ip6r_len % 2)
2483					return(EINVAL);
2484				if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2485					return(EINVAL);
2486				break;
2487			default:
2488				return(EINVAL);	/* not supported */
2489			}
2490
2491			if (needcopy) {
2492				opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT,
2493							  M_WAITOK);
2494				bcopy(rth, opt->ip6po_rthdr, rthlen);
2495			} else
2496				opt->ip6po_rthdr = rth;
2497
2498			break;
2499		}
2500
2501		default:
2502			return(ENOPROTOOPT);
2503		}
2504	}
2505
2506	return(0);
2507}
2508
2509/*
2510 * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2511 * packet to the input queue of a specified interface.  Note that this
2512 * calls the output routine of the loopback "driver", but with an interface
2513 * pointer that might NOT be &loif -- easier than replicating that code here.
2514 */
2515void
2516ip6_mloopback(ifp, m, dst)
2517	struct ifnet *ifp;
2518	struct mbuf *m;
2519	struct sockaddr_in6 *dst;
2520{
2521	struct mbuf *copym;
2522	struct ip6_hdr *ip6;
2523
2524	copym = m_copy(m, 0, M_COPYALL);
2525	if (copym == NULL)
2526		return;
2527
2528	/*
2529	 * Make sure to deep-copy IPv6 header portion in case the data
2530	 * is in an mbuf cluster, so that we can safely override the IPv6
2531	 * header portion later.
2532	 */
2533	if ((copym->m_flags & M_EXT) != 0 ||
2534	    copym->m_len < sizeof(struct ip6_hdr)) {
2535		copym = m_pullup(copym, sizeof(struct ip6_hdr));
2536		if (copym == NULL)
2537			return;
2538	}
2539
2540#ifdef DIAGNOSTIC
2541	if (copym->m_len < sizeof(*ip6)) {
2542		m_freem(copym);
2543		return;
2544	}
2545#endif
2546
2547	ip6 = mtod(copym, struct ip6_hdr *);
2548#ifndef SCOPEDROUTING
2549	/*
2550	 * clear embedded scope identifiers if necessary.
2551	 * in6_clearscope will touch the addresses only when necessary.
2552	 */
2553	in6_clearscope(&ip6->ip6_src);
2554	in6_clearscope(&ip6->ip6_dst);
2555#endif
2556
2557	(void)if_simloop(ifp, copym, dst->sin6_family, 0);
2558}
2559
2560/*
2561 * Chop IPv6 header off from the payload.
2562 */
2563static int
2564ip6_splithdr(m, exthdrs)
2565	struct mbuf *m;
2566	struct ip6_exthdrs *exthdrs;
2567{
2568	struct mbuf *mh;
2569	struct ip6_hdr *ip6;
2570
2571	ip6 = mtod(m, struct ip6_hdr *);
2572	if (m->m_len > sizeof(*ip6)) {
2573		MGETHDR(mh, M_DONTWAIT, MT_HEADER);
2574		if (mh == 0) {
2575			m_freem(m);
2576			return ENOBUFS;
2577		}
2578		M_COPY_PKTHDR(mh, m);
2579		MH_ALIGN(mh, sizeof(*ip6));
2580		m->m_flags &= ~M_PKTHDR;
2581		m->m_len -= sizeof(*ip6);
2582		m->m_data += sizeof(*ip6);
2583		mh->m_next = m;
2584		m = mh;
2585		m->m_len = sizeof(*ip6);
2586		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
2587	}
2588	exthdrs->ip6e_ip6 = m;
2589	return 0;
2590}
2591
2592/*
2593 * Compute IPv6 extension header length.
2594 */
2595int
2596ip6_optlen(in6p)
2597	struct in6pcb *in6p;
2598{
2599	int len;
2600
2601	if (!in6p->in6p_outputopts)
2602		return 0;
2603
2604	len = 0;
2605#define elen(x) \
2606    (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
2607
2608	len += elen(in6p->in6p_outputopts->ip6po_hbh);
2609	if (in6p->in6p_outputopts->ip6po_rthdr)
2610		/* dest1 is valid with rthdr only */
2611		len += elen(in6p->in6p_outputopts->ip6po_dest1);
2612	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
2613	len += elen(in6p->in6p_outputopts->ip6po_dest2);
2614	return len;
2615#undef elen
2616}
2617