xref: /freebsd/sys/netinet6/ip6_output.c (revision 7d536dc855c85c15bf45f033d108a61b1f3cecc3)
1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
30  */
31 
32 /*-
33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 4. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
61  */
62 
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65 
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipfw.h"
69 #include "opt_ipsec.h"
70 #include "opt_sctp.h"
71 #include "opt_route.h"
72 #include "opt_rss.h"
73 
74 #include <sys/param.h>
75 #include <sys/kernel.h>
76 #include <sys/malloc.h>
77 #include <sys/mbuf.h>
78 #include <sys/errno.h>
79 #include <sys/priv.h>
80 #include <sys/proc.h>
81 #include <sys/protosw.h>
82 #include <sys/socket.h>
83 #include <sys/socketvar.h>
84 #include <sys/syslog.h>
85 #include <sys/ucred.h>
86 
87 #include <machine/in_cksum.h>
88 
89 #include <net/if.h>
90 #include <net/if_var.h>
91 #include <net/netisr.h>
92 #include <net/route.h>
93 #include <net/pfil.h>
94 #include <net/rss_config.h>
95 #include <net/vnet.h>
96 
97 #include <netinet/in.h>
98 #include <netinet/in_var.h>
99 #include <netinet/ip_var.h>
100 #include <netinet6/in6_fib.h>
101 #include <netinet6/in6_var.h>
102 #include <netinet/ip6.h>
103 #include <netinet/icmp6.h>
104 #include <netinet6/ip6_var.h>
105 #include <netinet/in_pcb.h>
106 #include <netinet/tcp_var.h>
107 #include <netinet6/nd6.h>
108 #include <netinet6/in6_rss.h>
109 
110 #ifdef IPSEC
111 #include <netipsec/ipsec.h>
112 #include <netipsec/ipsec6.h>
113 #include <netipsec/key.h>
114 #include <netinet6/ip6_ipsec.h>
115 #endif /* IPSEC */
116 #ifdef SCTP
117 #include <netinet/sctp.h>
118 #include <netinet/sctp_crc32.h>
119 #endif
120 
121 #include <netinet6/ip6protosw.h>
122 #include <netinet6/scope6_var.h>
123 
124 #ifdef FLOWTABLE
125 #include <net/flowtable.h>
126 #endif
127 
128 extern int in6_mcast_loop;
129 
130 struct ip6_exthdrs {
131 	struct mbuf *ip6e_ip6;
132 	struct mbuf *ip6e_hbh;
133 	struct mbuf *ip6e_dest1;
134 	struct mbuf *ip6e_rthdr;
135 	struct mbuf *ip6e_dest2;
136 };
137 
138 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
139 			   struct ucred *, int);
140 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
141 	struct socket *, struct sockopt *);
142 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
143 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
144 	struct ucred *, int, int, int);
145 
146 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
147 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
148 	struct ip6_frag **);
149 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
150 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
151 static int ip6_getpmtu(struct route_in6 *, int,
152 	struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
153 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
154 	u_long *, int *);
155 static int ip6_getpmtu_ctl(u_int, struct in6_addr *, u_long *);
156 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
157 
158 
159 /*
160  * Make an extension header from option data.  hp is the source, and
161  * mp is the destination.
162  */
163 #define MAKE_EXTHDR(hp, mp)						\
164     do {								\
165 	if (hp) {							\
166 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
167 		error = ip6_copyexthdr((mp), (caddr_t)(hp),		\
168 		    ((eh)->ip6e_len + 1) << 3);				\
169 		if (error)						\
170 			goto freehdrs;					\
171 	}								\
172     } while (/*CONSTCOND*/ 0)
173 
174 /*
175  * Form a chain of extension headers.
176  * m is the extension header mbuf
177  * mp is the previous mbuf in the chain
178  * p is the next header
179  * i is the type of option.
180  */
181 #define MAKE_CHAIN(m, mp, p, i)\
182     do {\
183 	if (m) {\
184 		if (!hdrsplit) \
185 			panic("assumption failed: hdr not split"); \
186 		*mtod((m), u_char *) = *(p);\
187 		*(p) = (i);\
188 		p = mtod((m), u_char *);\
189 		(m)->m_next = (mp)->m_next;\
190 		(mp)->m_next = (m);\
191 		(mp) = (m);\
192 	}\
193     } while (/*CONSTCOND*/ 0)
194 
195 void
196 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
197 {
198 	u_short csum;
199 
200 	csum = in_cksum_skip(m, offset + plen, offset);
201 	if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
202 		csum = 0xffff;
203 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
204 
205 	if (offset + sizeof(u_short) > m->m_len) {
206 		printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
207 		    "csum_flags=%b\n", __func__, m->m_len, plen, offset,
208 		    (int)m->m_pkthdr.csum_flags, CSUM_BITS);
209 		/*
210 		 * XXX this should not happen, but if it does, the correct
211 		 * behavior may be to insert the checksum in the appropriate
212 		 * next mbuf in the chain.
213 		 */
214 		return;
215 	}
216 	*(u_short *)(m->m_data + offset) = csum;
217 }
218 
219 int
220 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
221     int mtu, uint32_t id)
222 {
223 	struct mbuf *m, **mnext, *m_frgpart;
224 	struct ip6_hdr *ip6, *mhip6;
225 	struct ip6_frag *ip6f;
226 	int off;
227 	int error;
228 	int tlen = m0->m_pkthdr.len;
229 
230 	m = m0;
231 	ip6 = mtod(m, struct ip6_hdr *);
232 	mnext = &m->m_nextpkt;
233 
234 	for (off = hlen; off < tlen; off += mtu) {
235 		m = m_gethdr(M_NOWAIT, MT_DATA);
236 		if (!m) {
237 			IP6STAT_INC(ip6s_odropped);
238 			return (ENOBUFS);
239 		}
240 		m->m_flags = m0->m_flags & M_COPYFLAGS;
241 		*mnext = m;
242 		mnext = &m->m_nextpkt;
243 		m->m_data += max_linkhdr;
244 		mhip6 = mtod(m, struct ip6_hdr *);
245 		*mhip6 = *ip6;
246 		m->m_len = sizeof(*mhip6);
247 		error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
248 		if (error) {
249 			IP6STAT_INC(ip6s_odropped);
250 			return (error);
251 		}
252 		ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
253 		if (off + mtu >= tlen)
254 			mtu = tlen - off;
255 		else
256 			ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
257 		mhip6->ip6_plen = htons((u_short)(mtu + hlen +
258 		    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
259 		if ((m_frgpart = m_copy(m0, off, mtu)) == 0) {
260 			IP6STAT_INC(ip6s_odropped);
261 			return (ENOBUFS);
262 		}
263 		m_cat(m, m_frgpart);
264 		m->m_pkthdr.len = mtu + hlen + sizeof(*ip6f);
265 		m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
266 		m->m_pkthdr.rcvif = NULL;
267 		ip6f->ip6f_reserved = 0;
268 		ip6f->ip6f_ident = id;
269 		ip6f->ip6f_nxt = nextproto;
270 		IP6STAT_INC(ip6s_ofragments);
271 		in6_ifstat_inc(ifp, ifs6_out_fragcreat);
272 	}
273 
274 	return (0);
275 }
276 
277 /*
278  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
279  * header (with pri, len, nxt, hlim, src, dst).
280  * This function may modify ver and hlim only.
281  * The mbuf chain containing the packet will be freed.
282  * The mbuf opt, if present, will not be freed.
283  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
284  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
285  * then result of route lookup is stored in ro->ro_rt.
286  *
287  * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
288  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
289  * which is rt_mtu.
290  *
291  * ifpp - XXX: just for statistics
292  */
293 /*
294  * XXX TODO: no flowid is assigned for outbound flows?
295  */
296 int
297 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
298     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
299     struct ifnet **ifpp, struct inpcb *inp)
300 {
301 	struct ip6_hdr *ip6;
302 	struct ifnet *ifp, *origifp;
303 	struct mbuf *m = m0;
304 	struct mbuf *mprev = NULL;
305 	int hlen, tlen, len;
306 	struct route_in6 ip6route;
307 	struct rtentry *rt = NULL;
308 	struct sockaddr_in6 *dst, src_sa, dst_sa;
309 	struct in6_addr odst;
310 	int error = 0;
311 	struct in6_ifaddr *ia = NULL;
312 	u_long mtu;
313 	int alwaysfrag, dontfrag;
314 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
315 	struct ip6_exthdrs exthdrs;
316 	struct in6_addr finaldst, src0, dst0;
317 	u_int32_t zone;
318 	struct route_in6 *ro_pmtu = NULL;
319 	int hdrsplit = 0;
320 	int sw_csum, tso;
321 	int needfiblookup;
322 	uint32_t fibnum;
323 	struct m_tag *fwd_tag = NULL;
324 	uint32_t id;
325 
326 	ip6 = mtod(m, struct ip6_hdr *);
327 	if (ip6 == NULL) {
328 		printf ("ip6 is NULL");
329 		goto bad;
330 	}
331 
332 	if (inp != NULL) {
333 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
334 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
335 			/* unconditionally set flowid */
336 			m->m_pkthdr.flowid = inp->inp_flowid;
337 			M_HASHTYPE_SET(m, inp->inp_flowtype);
338 		}
339 	}
340 
341 	finaldst = ip6->ip6_dst;
342 	bzero(&exthdrs, sizeof(exthdrs));
343 	if (opt) {
344 		/* Hop-by-Hop options header */
345 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
346 		/* Destination options header(1st part) */
347 		if (opt->ip6po_rthdr) {
348 			/*
349 			 * Destination options header(1st part)
350 			 * This only makes sense with a routing header.
351 			 * See Section 9.2 of RFC 3542.
352 			 * Disabling this part just for MIP6 convenience is
353 			 * a bad idea.  We need to think carefully about a
354 			 * way to make the advanced API coexist with MIP6
355 			 * options, which might automatically be inserted in
356 			 * the kernel.
357 			 */
358 			MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
359 		}
360 		/* Routing header */
361 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
362 		/* Destination options header(2nd part) */
363 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
364 	}
365 
366 #ifdef IPSEC
367 	/*
368 	 * IPSec checking which handles several cases.
369 	 * FAST IPSEC: We re-injected the packet.
370 	 * XXX: need scope argument.
371 	 */
372 	switch(ip6_ipsec_output(&m, inp, &error))
373 	{
374 	case 1:                 /* Bad packet */
375 		goto freehdrs;
376 	case -1:                /* IPSec done */
377 		goto done;
378 	case 0:                 /* No IPSec */
379 	default:
380 		break;
381 	}
382 #endif /* IPSEC */
383 
384 	/*
385 	 * Calculate the total length of the extension header chain.
386 	 * Keep the length of the unfragmentable part for fragmentation.
387 	 */
388 	optlen = 0;
389 	if (exthdrs.ip6e_hbh)
390 		optlen += exthdrs.ip6e_hbh->m_len;
391 	if (exthdrs.ip6e_dest1)
392 		optlen += exthdrs.ip6e_dest1->m_len;
393 	if (exthdrs.ip6e_rthdr)
394 		optlen += exthdrs.ip6e_rthdr->m_len;
395 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
396 
397 	/* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
398 	if (exthdrs.ip6e_dest2)
399 		optlen += exthdrs.ip6e_dest2->m_len;
400 
401 	/*
402 	 * If there is at least one extension header,
403 	 * separate IP6 header from the payload.
404 	 */
405 	if (optlen && !hdrsplit) {
406 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
407 			m = NULL;
408 			goto freehdrs;
409 		}
410 		m = exthdrs.ip6e_ip6;
411 		hdrsplit++;
412 	}
413 
414 	/* adjust pointer */
415 	ip6 = mtod(m, struct ip6_hdr *);
416 
417 	/* adjust mbuf packet header length */
418 	m->m_pkthdr.len += optlen;
419 	plen = m->m_pkthdr.len - sizeof(*ip6);
420 
421 	/* If this is a jumbo payload, insert a jumbo payload option. */
422 	if (plen > IPV6_MAXPACKET) {
423 		if (!hdrsplit) {
424 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
425 				m = NULL;
426 				goto freehdrs;
427 			}
428 			m = exthdrs.ip6e_ip6;
429 			hdrsplit++;
430 		}
431 		/* adjust pointer */
432 		ip6 = mtod(m, struct ip6_hdr *);
433 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
434 			goto freehdrs;
435 		ip6->ip6_plen = 0;
436 	} else
437 		ip6->ip6_plen = htons(plen);
438 
439 	/*
440 	 * Concatenate headers and fill in next header fields.
441 	 * Here we have, on "m"
442 	 *	IPv6 payload
443 	 * and we insert headers accordingly.  Finally, we should be getting:
444 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
445 	 *
446 	 * during the header composing process, "m" points to IPv6 header.
447 	 * "mprev" points to an extension header prior to esp.
448 	 */
449 	u_char *nexthdrp = &ip6->ip6_nxt;
450 	mprev = m;
451 
452 	/*
453 	 * we treat dest2 specially.  this makes IPsec processing
454 	 * much easier.  the goal here is to make mprev point the
455 	 * mbuf prior to dest2.
456 	 *
457 	 * result: IPv6 dest2 payload
458 	 * m and mprev will point to IPv6 header.
459 	 */
460 	if (exthdrs.ip6e_dest2) {
461 		if (!hdrsplit)
462 			panic("assumption failed: hdr not split");
463 		exthdrs.ip6e_dest2->m_next = m->m_next;
464 		m->m_next = exthdrs.ip6e_dest2;
465 		*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
466 		ip6->ip6_nxt = IPPROTO_DSTOPTS;
467 	}
468 
469 	/*
470 	 * result: IPv6 hbh dest1 rthdr dest2 payload
471 	 * m will point to IPv6 header.  mprev will point to the
472 	 * extension header prior to dest2 (rthdr in the above case).
473 	 */
474 	MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
475 	MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
476 		   IPPROTO_DSTOPTS);
477 	MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
478 		   IPPROTO_ROUTING);
479 
480 	/*
481 	 * If there is a routing header, discard the packet.
482 	 */
483 	if (exthdrs.ip6e_rthdr) {
484 		 error = EINVAL;
485 		 goto bad;
486 	}
487 
488 	/* Source address validation */
489 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
490 	    (flags & IPV6_UNSPECSRC) == 0) {
491 		error = EOPNOTSUPP;
492 		IP6STAT_INC(ip6s_badscope);
493 		goto bad;
494 	}
495 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
496 		error = EOPNOTSUPP;
497 		IP6STAT_INC(ip6s_badscope);
498 		goto bad;
499 	}
500 
501 	IP6STAT_INC(ip6s_localout);
502 
503 	/*
504 	 * Route packet.
505 	 */
506 	if (ro == 0) {
507 		ro = &ip6route;
508 		bzero((caddr_t)ro, sizeof(*ro));
509 	}
510 	ro_pmtu = ro;
511 	if (opt && opt->ip6po_rthdr)
512 		ro = &opt->ip6po_route;
513 	dst = (struct sockaddr_in6 *)&ro->ro_dst;
514 #ifdef FLOWTABLE
515 	if (ro->ro_rt == NULL)
516 		(void )flowtable_lookup(AF_INET6, m, (struct route *)ro);
517 #endif
518 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
519 again:
520 	/*
521 	 * if specified, try to fill in the traffic class field.
522 	 * do not override if a non-zero value is already set.
523 	 * we check the diffserv field and the ecn field separately.
524 	 */
525 	if (opt && opt->ip6po_tclass >= 0) {
526 		int mask = 0;
527 
528 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
529 			mask |= 0xfc;
530 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
531 			mask |= 0x03;
532 		if (mask != 0)
533 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
534 	}
535 
536 	/* fill in or override the hop limit field, if necessary. */
537 	if (opt && opt->ip6po_hlim != -1)
538 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
539 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
540 		if (im6o != NULL)
541 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
542 		else
543 			ip6->ip6_hlim = V_ip6_defmcasthlim;
544 	}
545 
546 	/* adjust pointer */
547 	ip6 = mtod(m, struct ip6_hdr *);
548 
549 	if (ro->ro_rt && fwd_tag == NULL) {
550 		rt = ro->ro_rt;
551 		ifp = ro->ro_rt->rt_ifp;
552 	} else {
553 		if (fwd_tag == NULL) {
554 			bzero(&dst_sa, sizeof(dst_sa));
555 			dst_sa.sin6_family = AF_INET6;
556 			dst_sa.sin6_len = sizeof(dst_sa);
557 			dst_sa.sin6_addr = ip6->ip6_dst;
558 		}
559 		error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
560 		    &rt, fibnum);
561 		if (error != 0) {
562 			if (ifp != NULL)
563 				in6_ifstat_inc(ifp, ifs6_out_discard);
564 			goto bad;
565 		}
566 	}
567 	if (rt == NULL) {
568 		/*
569 		 * If in6_selectroute() does not return a route entry,
570 		 * dst may not have been updated.
571 		 */
572 		*dst = dst_sa;	/* XXX */
573 	}
574 
575 	/*
576 	 * then rt (for unicast) and ifp must be non-NULL valid values.
577 	 */
578 	if ((flags & IPV6_FORWARDING) == 0) {
579 		/* XXX: the FORWARDING flag can be set for mrouting. */
580 		in6_ifstat_inc(ifp, ifs6_out_request);
581 	}
582 	if (rt != NULL) {
583 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
584 		counter_u64_add(rt->rt_pksent, 1);
585 	}
586 
587 
588 	/*
589 	 * The outgoing interface must be in the zone of source and
590 	 * destination addresses.
591 	 */
592 	origifp = ifp;
593 
594 	src0 = ip6->ip6_src;
595 	if (in6_setscope(&src0, origifp, &zone))
596 		goto badscope;
597 	bzero(&src_sa, sizeof(src_sa));
598 	src_sa.sin6_family = AF_INET6;
599 	src_sa.sin6_len = sizeof(src_sa);
600 	src_sa.sin6_addr = ip6->ip6_src;
601 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
602 		goto badscope;
603 
604 	dst0 = ip6->ip6_dst;
605 	if (in6_setscope(&dst0, origifp, &zone))
606 		goto badscope;
607 	/* re-initialize to be sure */
608 	bzero(&dst_sa, sizeof(dst_sa));
609 	dst_sa.sin6_family = AF_INET6;
610 	dst_sa.sin6_len = sizeof(dst_sa);
611 	dst_sa.sin6_addr = ip6->ip6_dst;
612 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
613 		goto badscope;
614 	}
615 
616 	/* We should use ia_ifp to support the case of
617 	 * sending packets to an address of our own.
618 	 */
619 	if (ia != NULL && ia->ia_ifp)
620 		ifp = ia->ia_ifp;
621 
622 	/* scope check is done. */
623 	goto routefound;
624 
625   badscope:
626 	IP6STAT_INC(ip6s_badscope);
627 	in6_ifstat_inc(origifp, ifs6_out_discard);
628 	if (error == 0)
629 		error = EHOSTUNREACH; /* XXX */
630 	goto bad;
631 
632   routefound:
633 	if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
634 		if (opt && opt->ip6po_nextroute.ro_rt) {
635 			/*
636 			 * The nexthop is explicitly specified by the
637 			 * application.  We assume the next hop is an IPv6
638 			 * address.
639 			 */
640 			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
641 		}
642 		else if ((rt->rt_flags & RTF_GATEWAY))
643 			dst = (struct sockaddr_in6 *)rt->rt_gateway;
644 	}
645 
646 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
647 		m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
648 	} else {
649 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
650 		in6_ifstat_inc(ifp, ifs6_out_mcast);
651 		/*
652 		 * Confirm that the outgoing interface supports multicast.
653 		 */
654 		if (!(ifp->if_flags & IFF_MULTICAST)) {
655 			IP6STAT_INC(ip6s_noroute);
656 			in6_ifstat_inc(ifp, ifs6_out_discard);
657 			error = ENETUNREACH;
658 			goto bad;
659 		}
660 		if ((im6o == NULL && in6_mcast_loop) ||
661 		    (im6o && im6o->im6o_multicast_loop)) {
662 			/*
663 			 * Loop back multicast datagram if not expressly
664 			 * forbidden to do so, even if we have not joined
665 			 * the address; protocols will filter it later,
666 			 * thus deferring a hash lookup and lock acquisition
667 			 * at the expense of an m_copym().
668 			 */
669 			ip6_mloopback(ifp, m);
670 		} else {
671 			/*
672 			 * If we are acting as a multicast router, perform
673 			 * multicast forwarding as if the packet had just
674 			 * arrived on the interface to which we are about
675 			 * to send.  The multicast forwarding function
676 			 * recursively calls this function, using the
677 			 * IPV6_FORWARDING flag to prevent infinite recursion.
678 			 *
679 			 * Multicasts that are looped back by ip6_mloopback(),
680 			 * above, will be forwarded by the ip6_input() routine,
681 			 * if necessary.
682 			 */
683 			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
684 				/*
685 				 * XXX: ip6_mforward expects that rcvif is NULL
686 				 * when it is called from the originating path.
687 				 * However, it may not always be the case.
688 				 */
689 				m->m_pkthdr.rcvif = NULL;
690 				if (ip6_mforward(ip6, ifp, m) != 0) {
691 					m_freem(m);
692 					goto done;
693 				}
694 			}
695 		}
696 		/*
697 		 * Multicasts with a hoplimit of zero may be looped back,
698 		 * above, but must not be transmitted on a network.
699 		 * Also, multicasts addressed to the loopback interface
700 		 * are not sent -- the above call to ip6_mloopback() will
701 		 * loop back a copy if this host actually belongs to the
702 		 * destination group on the loopback interface.
703 		 */
704 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
705 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
706 			m_freem(m);
707 			goto done;
708 		}
709 	}
710 
711 	/*
712 	 * Fill the outgoing inteface to tell the upper layer
713 	 * to increment per-interface statistics.
714 	 */
715 	if (ifpp)
716 		*ifpp = ifp;
717 
718 	/* Determine path MTU. */
719 	if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &finaldst, &mtu,
720 	    &alwaysfrag, fibnum)) != 0)
721 		goto bad;
722 
723 	/*
724 	 * The caller of this function may specify to use the minimum MTU
725 	 * in some cases.
726 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
727 	 * setting.  The logic is a bit complicated; by default, unicast
728 	 * packets will follow path MTU while multicast packets will be sent at
729 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
730 	 * including unicast ones will be sent at the minimum MTU.  Multicast
731 	 * packets will always be sent at the minimum MTU unless
732 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
733 	 * See RFC 3542 for more details.
734 	 */
735 	if (mtu > IPV6_MMTU) {
736 		if ((flags & IPV6_MINMTU))
737 			mtu = IPV6_MMTU;
738 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
739 			mtu = IPV6_MMTU;
740 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
741 			 (opt == NULL ||
742 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
743 			mtu = IPV6_MMTU;
744 		}
745 	}
746 
747 	/*
748 	 * clear embedded scope identifiers if necessary.
749 	 * in6_clearscope will touch the addresses only when necessary.
750 	 */
751 	in6_clearscope(&ip6->ip6_src);
752 	in6_clearscope(&ip6->ip6_dst);
753 
754 	/*
755 	 * If the outgoing packet contains a hop-by-hop options header,
756 	 * it must be examined and processed even by the source node.
757 	 * (RFC 2460, section 4.)
758 	 */
759 	if (exthdrs.ip6e_hbh) {
760 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
761 		u_int32_t dummy; /* XXX unused */
762 		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
763 
764 #ifdef DIAGNOSTIC
765 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
766 			panic("ip6e_hbh is not contiguous");
767 #endif
768 		/*
769 		 *  XXX: if we have to send an ICMPv6 error to the sender,
770 		 *       we need the M_LOOP flag since icmp6_error() expects
771 		 *       the IPv6 and the hop-by-hop options header are
772 		 *       contiguous unless the flag is set.
773 		 */
774 		m->m_flags |= M_LOOP;
775 		m->m_pkthdr.rcvif = ifp;
776 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
777 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
778 		    &dummy, &plen) < 0) {
779 			/* m was already freed at this point */
780 			error = EINVAL;/* better error? */
781 			goto done;
782 		}
783 		m->m_flags &= ~M_LOOP; /* XXX */
784 		m->m_pkthdr.rcvif = NULL;
785 	}
786 
787 	/* Jump over all PFIL processing if hooks are not active. */
788 	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
789 		goto passout;
790 
791 	odst = ip6->ip6_dst;
792 	/* Run through list of hooks for output packets. */
793 	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
794 	if (error != 0 || m == NULL)
795 		goto done;
796 	ip6 = mtod(m, struct ip6_hdr *);
797 
798 	needfiblookup = 0;
799 	/* See if destination IP address was changed by packet filter. */
800 	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
801 		m->m_flags |= M_SKIP_FIREWALL;
802 		/* If destination is now ourself drop to ip6_input(). */
803 		if (in6_localip(&ip6->ip6_dst)) {
804 			m->m_flags |= M_FASTFWD_OURS;
805 			if (m->m_pkthdr.rcvif == NULL)
806 				m->m_pkthdr.rcvif = V_loif;
807 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
808 				m->m_pkthdr.csum_flags |=
809 				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
810 				m->m_pkthdr.csum_data = 0xffff;
811 			}
812 #ifdef SCTP
813 			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
814 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
815 #endif
816 			error = netisr_queue(NETISR_IPV6, m);
817 			goto done;
818 		} else
819 			needfiblookup = 1; /* Redo the routing table lookup. */
820 	}
821 	/* See if fib was changed by packet filter. */
822 	if (fibnum != M_GETFIB(m)) {
823 		m->m_flags |= M_SKIP_FIREWALL;
824 		fibnum = M_GETFIB(m);
825 		RO_RTFREE(ro);
826 		needfiblookup = 1;
827 	}
828 	if (needfiblookup)
829 		goto again;
830 
831 	/* See if local, if yes, send it to netisr. */
832 	if (m->m_flags & M_FASTFWD_OURS) {
833 		if (m->m_pkthdr.rcvif == NULL)
834 			m->m_pkthdr.rcvif = V_loif;
835 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
836 			m->m_pkthdr.csum_flags |=
837 			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
838 			m->m_pkthdr.csum_data = 0xffff;
839 		}
840 #ifdef SCTP
841 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
842 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
843 #endif
844 		error = netisr_queue(NETISR_IPV6, m);
845 		goto done;
846 	}
847 	/* Or forward to some other address? */
848 	if ((m->m_flags & M_IP6_NEXTHOP) &&
849 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
850 		dst = (struct sockaddr_in6 *)&ro->ro_dst;
851 		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
852 		m->m_flags |= M_SKIP_FIREWALL;
853 		m->m_flags &= ~M_IP6_NEXTHOP;
854 		m_tag_delete(m, fwd_tag);
855 		goto again;
856 	}
857 
858 passout:
859 	/*
860 	 * Send the packet to the outgoing interface.
861 	 * If necessary, do IPv6 fragmentation before sending.
862 	 *
863 	 * the logic here is rather complex:
864 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
865 	 * 1-a:	send as is if tlen <= path mtu
866 	 * 1-b:	fragment if tlen > path mtu
867 	 *
868 	 * 2: if user asks us not to fragment (dontfrag == 1)
869 	 * 2-a:	send as is if tlen <= interface mtu
870 	 * 2-b:	error if tlen > interface mtu
871 	 *
872 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
873 	 *	always fragment
874 	 *
875 	 * 4: if dontfrag == 1 && alwaysfrag == 1
876 	 *	error, as we cannot handle this conflicting request
877 	 */
878 	sw_csum = m->m_pkthdr.csum_flags;
879 	if (!hdrsplit) {
880 		tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
881 		sw_csum &= ~ifp->if_hwassist;
882 	} else
883 		tso = 0;
884 	/*
885 	 * If we added extension headers, we will not do TSO and calculate the
886 	 * checksums ourselves for now.
887 	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
888 	 * with ext. hdrs.
889 	 */
890 	if (sw_csum & CSUM_DELAY_DATA_IPV6) {
891 		sw_csum &= ~CSUM_DELAY_DATA_IPV6;
892 		in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
893 	}
894 #ifdef SCTP
895 	if (sw_csum & CSUM_SCTP_IPV6) {
896 		sw_csum &= ~CSUM_SCTP_IPV6;
897 		sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
898 	}
899 #endif
900 	m->m_pkthdr.csum_flags &= ifp->if_hwassist;
901 	tlen = m->m_pkthdr.len;
902 
903 	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
904 		dontfrag = 1;
905 	else
906 		dontfrag = 0;
907 	if (dontfrag && alwaysfrag) {	/* case 4 */
908 		/* conflicting request - can't transmit */
909 		error = EMSGSIZE;
910 		goto bad;
911 	}
912 	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* case 2-b */
913 		/*
914 		 * Even if the DONTFRAG option is specified, we cannot send the
915 		 * packet when the data length is larger than the MTU of the
916 		 * outgoing interface.
917 		 * Notify the error by sending IPV6_PATHMTU ancillary data if
918 		 * application wanted to know the MTU value. Also return an
919 		 * error code (this is not described in the API spec).
920 		 */
921 		if (inp != NULL)
922 			ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
923 		error = EMSGSIZE;
924 		goto bad;
925 	}
926 
927 	/*
928 	 * transmit packet without fragmentation
929 	 */
930 	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* case 1-a and 2-a */
931 		struct in6_ifaddr *ia6;
932 
933 		ip6 = mtod(m, struct ip6_hdr *);
934 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
935 		if (ia6) {
936 			/* Record statistics for this interface address. */
937 			counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
938 			counter_u64_add(ia6->ia_ifa.ifa_obytes,
939 			    m->m_pkthdr.len);
940 			ifa_free(&ia6->ia_ifa);
941 		}
942 		error = nd6_output_ifp(ifp, origifp, m, dst, NULL);
943 		goto done;
944 	}
945 
946 	/*
947 	 * try to fragment the packet.  case 1-b and 3
948 	 */
949 	if (mtu < IPV6_MMTU) {
950 		/* path MTU cannot be less than IPV6_MMTU */
951 		error = EMSGSIZE;
952 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
953 		goto bad;
954 	} else if (ip6->ip6_plen == 0) {
955 		/* jumbo payload cannot be fragmented */
956 		error = EMSGSIZE;
957 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
958 		goto bad;
959 	} else {
960 		u_char nextproto;
961 
962 		/*
963 		 * Too large for the destination or interface;
964 		 * fragment if possible.
965 		 * Must be able to put at least 8 bytes per fragment.
966 		 */
967 		hlen = unfragpartlen;
968 		if (mtu > IPV6_MAXPACKET)
969 			mtu = IPV6_MAXPACKET;
970 
971 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
972 		if (len < 8) {
973 			error = EMSGSIZE;
974 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
975 			goto bad;
976 		}
977 
978 		/*
979 		 * If the interface will not calculate checksums on
980 		 * fragmented packets, then do it here.
981 		 * XXX-BZ handle the hw offloading case.  Need flags.
982 		 */
983 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
984 			in6_delayed_cksum(m, plen, hlen);
985 			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
986 		}
987 #ifdef SCTP
988 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
989 			sctp_delayed_cksum(m, hlen);
990 			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
991 		}
992 #endif
993 		/*
994 		 * Change the next header field of the last header in the
995 		 * unfragmentable part.
996 		 */
997 		if (exthdrs.ip6e_rthdr) {
998 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
999 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1000 		} else if (exthdrs.ip6e_dest1) {
1001 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1002 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1003 		} else if (exthdrs.ip6e_hbh) {
1004 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1005 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1006 		} else {
1007 			nextproto = ip6->ip6_nxt;
1008 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1009 		}
1010 
1011 		/*
1012 		 * Loop through length of segment after first fragment,
1013 		 * make new header and copy data of each part and link onto
1014 		 * chain.
1015 		 */
1016 		m0 = m;
1017 		id = htonl(ip6_randomid());
1018 		if ((error = ip6_fragment(ifp, m, hlen, nextproto, len, id)))
1019 			goto sendorfree;
1020 
1021 		in6_ifstat_inc(ifp, ifs6_out_fragok);
1022 	}
1023 
1024 	/*
1025 	 * Remove leading garbages.
1026 	 */
1027 sendorfree:
1028 	m = m0->m_nextpkt;
1029 	m0->m_nextpkt = 0;
1030 	m_freem(m0);
1031 	for (m0 = m; m; m = m0) {
1032 		m0 = m->m_nextpkt;
1033 		m->m_nextpkt = 0;
1034 		if (error == 0) {
1035 			/* Record statistics for this interface address. */
1036 			if (ia) {
1037 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1038 				counter_u64_add(ia->ia_ifa.ifa_obytes,
1039 				    m->m_pkthdr.len);
1040 			}
1041 			error = nd6_output_ifp(ifp, origifp, m, dst, NULL);
1042 		} else
1043 			m_freem(m);
1044 	}
1045 
1046 	if (error == 0)
1047 		IP6STAT_INC(ip6s_fragmented);
1048 
1049 done:
1050 	if (ro == &ip6route)
1051 		RO_RTFREE(ro);
1052 	return (error);
1053 
1054 freehdrs:
1055 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
1056 	m_freem(exthdrs.ip6e_dest1);
1057 	m_freem(exthdrs.ip6e_rthdr);
1058 	m_freem(exthdrs.ip6e_dest2);
1059 	/* FALLTHROUGH */
1060 bad:
1061 	if (m)
1062 		m_freem(m);
1063 	goto done;
1064 }
1065 
1066 static int
1067 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1068 {
1069 	struct mbuf *m;
1070 
1071 	if (hlen > MCLBYTES)
1072 		return (ENOBUFS); /* XXX */
1073 
1074 	if (hlen > MLEN)
1075 		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1076 	else
1077 		m = m_get(M_NOWAIT, MT_DATA);
1078 	if (m == NULL)
1079 		return (ENOBUFS);
1080 	m->m_len = hlen;
1081 	if (hdr)
1082 		bcopy(hdr, mtod(m, caddr_t), hlen);
1083 
1084 	*mp = m;
1085 	return (0);
1086 }
1087 
1088 /*
1089  * Insert jumbo payload option.
1090  */
1091 static int
1092 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1093 {
1094 	struct mbuf *mopt;
1095 	u_char *optbuf;
1096 	u_int32_t v;
1097 
1098 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1099 
1100 	/*
1101 	 * If there is no hop-by-hop options header, allocate new one.
1102 	 * If there is one but it doesn't have enough space to store the
1103 	 * jumbo payload option, allocate a cluster to store the whole options.
1104 	 * Otherwise, use it to store the options.
1105 	 */
1106 	if (exthdrs->ip6e_hbh == 0) {
1107 		mopt = m_get(M_NOWAIT, MT_DATA);
1108 		if (mopt == NULL)
1109 			return (ENOBUFS);
1110 		mopt->m_len = JUMBOOPTLEN;
1111 		optbuf = mtod(mopt, u_char *);
1112 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1113 		exthdrs->ip6e_hbh = mopt;
1114 	} else {
1115 		struct ip6_hbh *hbh;
1116 
1117 		mopt = exthdrs->ip6e_hbh;
1118 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1119 			/*
1120 			 * XXX assumption:
1121 			 * - exthdrs->ip6e_hbh is not referenced from places
1122 			 *   other than exthdrs.
1123 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1124 			 */
1125 			int oldoptlen = mopt->m_len;
1126 			struct mbuf *n;
1127 
1128 			/*
1129 			 * XXX: give up if the whole (new) hbh header does
1130 			 * not fit even in an mbuf cluster.
1131 			 */
1132 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1133 				return (ENOBUFS);
1134 
1135 			/*
1136 			 * As a consequence, we must always prepare a cluster
1137 			 * at this point.
1138 			 */
1139 			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1140 			if (n == NULL)
1141 				return (ENOBUFS);
1142 			n->m_len = oldoptlen + JUMBOOPTLEN;
1143 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1144 			    oldoptlen);
1145 			optbuf = mtod(n, caddr_t) + oldoptlen;
1146 			m_freem(mopt);
1147 			mopt = exthdrs->ip6e_hbh = n;
1148 		} else {
1149 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1150 			mopt->m_len += JUMBOOPTLEN;
1151 		}
1152 		optbuf[0] = IP6OPT_PADN;
1153 		optbuf[1] = 1;
1154 
1155 		/*
1156 		 * Adjust the header length according to the pad and
1157 		 * the jumbo payload option.
1158 		 */
1159 		hbh = mtod(mopt, struct ip6_hbh *);
1160 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1161 	}
1162 
1163 	/* fill in the option. */
1164 	optbuf[2] = IP6OPT_JUMBO;
1165 	optbuf[3] = 4;
1166 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1167 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1168 
1169 	/* finally, adjust the packet header length */
1170 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1171 
1172 	return (0);
1173 #undef JUMBOOPTLEN
1174 }
1175 
1176 /*
1177  * Insert fragment header and copy unfragmentable header portions.
1178  */
1179 static int
1180 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1181     struct ip6_frag **frghdrp)
1182 {
1183 	struct mbuf *n, *mlast;
1184 
1185 	if (hlen > sizeof(struct ip6_hdr)) {
1186 		n = m_copym(m0, sizeof(struct ip6_hdr),
1187 		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1188 		if (n == 0)
1189 			return (ENOBUFS);
1190 		m->m_next = n;
1191 	} else
1192 		n = m;
1193 
1194 	/* Search for the last mbuf of unfragmentable part. */
1195 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1196 		;
1197 
1198 	if (M_WRITABLE(mlast) &&
1199 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1200 		/* use the trailing space of the last mbuf for the fragment hdr */
1201 		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1202 		    mlast->m_len);
1203 		mlast->m_len += sizeof(struct ip6_frag);
1204 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1205 	} else {
1206 		/* allocate a new mbuf for the fragment header */
1207 		struct mbuf *mfrg;
1208 
1209 		mfrg = m_get(M_NOWAIT, MT_DATA);
1210 		if (mfrg == NULL)
1211 			return (ENOBUFS);
1212 		mfrg->m_len = sizeof(struct ip6_frag);
1213 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1214 		mlast->m_next = mfrg;
1215 	}
1216 
1217 	return (0);
1218 }
1219 
1220 /*
1221  * Calculates IPv6 path mtu for destination @dst.
1222  * Resulting MTU is stored in @mtup.
1223  *
1224  * Returns 0 on success.
1225  */
1226 static int
1227 ip6_getpmtu_ctl(u_int fibnum, struct in6_addr *dst, u_long *mtup)
1228 {
1229 	struct nhop6_extended nh6;
1230 	struct in6_addr kdst;
1231 	uint32_t scopeid;
1232 	struct ifnet *ifp;
1233 	u_long mtu;
1234 	int error;
1235 
1236 	in6_splitscope(dst, &kdst, &scopeid);
1237 	if (fib6_lookup_nh_ext(fibnum, &kdst, scopeid, NHR_REF, 0, &nh6) != 0)
1238 		return (EHOSTUNREACH);
1239 
1240 	ifp = nh6.nh_ifp;
1241 	mtu = nh6.nh_mtu;
1242 
1243 	error = ip6_calcmtu(ifp, dst, mtu, mtup, NULL);
1244 	fib6_free_nh_ext(fibnum, &nh6);
1245 
1246 	return (error);
1247 }
1248 
1249 /*
1250  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1251  * and cached data in @ro_pmtu.
1252  * MTU from (successful) route lookup is saved (along with dst)
1253  * inside @ro_pmtu to avoid subsequent route lookups after packet
1254  * filter processing.
1255  *
1256  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1257  * Returns 0 on success.
1258  */
1259 static int
1260 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1261     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1262     int *alwaysfragp, u_int fibnum)
1263 {
1264 	struct nhop6_basic nh6;
1265 	struct in6_addr kdst;
1266 	uint32_t scopeid;
1267 	struct sockaddr_in6 *sa6_dst;
1268 	u_long mtu;
1269 
1270 	mtu = 0;
1271 	if (do_lookup) {
1272 
1273 		/*
1274 		 * Here ro_pmtu has final destination address, while
1275 		 * ro might represent immediate destination.
1276 		 * Use ro_pmtu destination since mtu might differ.
1277 		 */
1278 		sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1279 		if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1280 			ro_pmtu->ro_mtu = 0;
1281 
1282 		if (ro_pmtu->ro_mtu == 0) {
1283 			bzero(sa6_dst, sizeof(*sa6_dst));
1284 			sa6_dst->sin6_family = AF_INET6;
1285 			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1286 			sa6_dst->sin6_addr = *dst;
1287 
1288 			in6_splitscope(dst, &kdst, &scopeid);
1289 			if (fib6_lookup_nh_basic(fibnum, &kdst, scopeid, 0, 0,
1290 			    &nh6) == 0)
1291 				ro_pmtu->ro_mtu = nh6.nh_mtu;
1292 		}
1293 
1294 		mtu = ro_pmtu->ro_mtu;
1295 	}
1296 
1297 	if (ro_pmtu->ro_rt)
1298 		mtu = ro_pmtu->ro_rt->rt_mtu;
1299 
1300 	return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp));
1301 }
1302 
1303 /*
1304  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1305  * hostcache data for @dst.
1306  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1307  *
1308  * Returns 0 on success.
1309  */
1310 static int
1311 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1312     u_long *mtup, int *alwaysfragp)
1313 {
1314 	u_long mtu = 0;
1315 	int alwaysfrag = 0;
1316 	int error = 0;
1317 
1318 	if (rt_mtu > 0) {
1319 		u_int32_t ifmtu;
1320 		struct in_conninfo inc;
1321 
1322 		bzero(&inc, sizeof(inc));
1323 		inc.inc_flags |= INC_ISIPV6;
1324 		inc.inc6_faddr = *dst;
1325 
1326 		ifmtu = IN6_LINKMTU(ifp);
1327 		mtu = tcp_hc_getmtu(&inc);
1328 		if (mtu)
1329 			mtu = min(mtu, rt_mtu);
1330 		else
1331 			mtu = rt_mtu;
1332 		if (mtu == 0)
1333 			mtu = ifmtu;
1334 		else if (mtu < IPV6_MMTU) {
1335 			/*
1336 			 * RFC2460 section 5, last paragraph:
1337 			 * if we record ICMPv6 too big message with
1338 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1339 			 * or smaller, with framgent header attached.
1340 			 * (fragment header is needed regardless from the
1341 			 * packet size, for translators to identify packets)
1342 			 */
1343 			alwaysfrag = 1;
1344 			mtu = IPV6_MMTU;
1345 		}
1346 	} else if (ifp) {
1347 		mtu = IN6_LINKMTU(ifp);
1348 	} else
1349 		error = EHOSTUNREACH; /* XXX */
1350 
1351 	*mtup = mtu;
1352 	if (alwaysfragp)
1353 		*alwaysfragp = alwaysfrag;
1354 	return (error);
1355 }
1356 
1357 /*
1358  * IP6 socket option processing.
1359  */
1360 int
1361 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1362 {
1363 	int optdatalen, uproto;
1364 	void *optdata;
1365 	struct inpcb *in6p = sotoinpcb(so);
1366 	int error, optval;
1367 	int level, op, optname;
1368 	int optlen;
1369 	struct thread *td;
1370 #ifdef	RSS
1371 	uint32_t rss_bucket;
1372 	int retval;
1373 #endif
1374 
1375 	level = sopt->sopt_level;
1376 	op = sopt->sopt_dir;
1377 	optname = sopt->sopt_name;
1378 	optlen = sopt->sopt_valsize;
1379 	td = sopt->sopt_td;
1380 	error = 0;
1381 	optval = 0;
1382 	uproto = (int)so->so_proto->pr_protocol;
1383 
1384 	if (level != IPPROTO_IPV6) {
1385 		error = EINVAL;
1386 
1387 		if (sopt->sopt_level == SOL_SOCKET &&
1388 		    sopt->sopt_dir == SOPT_SET) {
1389 			switch (sopt->sopt_name) {
1390 			case SO_REUSEADDR:
1391 				INP_WLOCK(in6p);
1392 				if ((so->so_options & SO_REUSEADDR) != 0)
1393 					in6p->inp_flags2 |= INP_REUSEADDR;
1394 				else
1395 					in6p->inp_flags2 &= ~INP_REUSEADDR;
1396 				INP_WUNLOCK(in6p);
1397 				error = 0;
1398 				break;
1399 			case SO_REUSEPORT:
1400 				INP_WLOCK(in6p);
1401 				if ((so->so_options & SO_REUSEPORT) != 0)
1402 					in6p->inp_flags2 |= INP_REUSEPORT;
1403 				else
1404 					in6p->inp_flags2 &= ~INP_REUSEPORT;
1405 				INP_WUNLOCK(in6p);
1406 				error = 0;
1407 				break;
1408 			case SO_SETFIB:
1409 				INP_WLOCK(in6p);
1410 				in6p->inp_inc.inc_fibnum = so->so_fibnum;
1411 				INP_WUNLOCK(in6p);
1412 				error = 0;
1413 				break;
1414 			default:
1415 				break;
1416 			}
1417 		}
1418 	} else {		/* level == IPPROTO_IPV6 */
1419 		switch (op) {
1420 
1421 		case SOPT_SET:
1422 			switch (optname) {
1423 			case IPV6_2292PKTOPTIONS:
1424 #ifdef IPV6_PKTOPTIONS
1425 			case IPV6_PKTOPTIONS:
1426 #endif
1427 			{
1428 				struct mbuf *m;
1429 
1430 				error = soopt_getm(sopt, &m); /* XXX */
1431 				if (error != 0)
1432 					break;
1433 				error = soopt_mcopyin(sopt, m); /* XXX */
1434 				if (error != 0)
1435 					break;
1436 				error = ip6_pcbopts(&in6p->in6p_outputopts,
1437 						    m, so, sopt);
1438 				m_freem(m); /* XXX */
1439 				break;
1440 			}
1441 
1442 			/*
1443 			 * Use of some Hop-by-Hop options or some
1444 			 * Destination options, might require special
1445 			 * privilege.  That is, normal applications
1446 			 * (without special privilege) might be forbidden
1447 			 * from setting certain options in outgoing packets,
1448 			 * and might never see certain options in received
1449 			 * packets. [RFC 2292 Section 6]
1450 			 * KAME specific note:
1451 			 *  KAME prevents non-privileged users from sending or
1452 			 *  receiving ANY hbh/dst options in order to avoid
1453 			 *  overhead of parsing options in the kernel.
1454 			 */
1455 			case IPV6_RECVHOPOPTS:
1456 			case IPV6_RECVDSTOPTS:
1457 			case IPV6_RECVRTHDRDSTOPTS:
1458 				if (td != NULL) {
1459 					error = priv_check(td,
1460 					    PRIV_NETINET_SETHDROPTS);
1461 					if (error)
1462 						break;
1463 				}
1464 				/* FALLTHROUGH */
1465 			case IPV6_UNICAST_HOPS:
1466 			case IPV6_HOPLIMIT:
1467 
1468 			case IPV6_RECVPKTINFO:
1469 			case IPV6_RECVHOPLIMIT:
1470 			case IPV6_RECVRTHDR:
1471 			case IPV6_RECVPATHMTU:
1472 			case IPV6_RECVTCLASS:
1473 			case IPV6_RECVFLOWID:
1474 #ifdef	RSS
1475 			case IPV6_RECVRSSBUCKETID:
1476 #endif
1477 			case IPV6_V6ONLY:
1478 			case IPV6_AUTOFLOWLABEL:
1479 			case IPV6_BINDANY:
1480 			case IPV6_BINDMULTI:
1481 #ifdef	RSS
1482 			case IPV6_RSS_LISTEN_BUCKET:
1483 #endif
1484 				if (optname == IPV6_BINDANY && td != NULL) {
1485 					error = priv_check(td,
1486 					    PRIV_NETINET_BINDANY);
1487 					if (error)
1488 						break;
1489 				}
1490 
1491 				if (optlen != sizeof(int)) {
1492 					error = EINVAL;
1493 					break;
1494 				}
1495 				error = sooptcopyin(sopt, &optval,
1496 					sizeof optval, sizeof optval);
1497 				if (error)
1498 					break;
1499 				switch (optname) {
1500 
1501 				case IPV6_UNICAST_HOPS:
1502 					if (optval < -1 || optval >= 256)
1503 						error = EINVAL;
1504 					else {
1505 						/* -1 = kernel default */
1506 						in6p->in6p_hops = optval;
1507 						if ((in6p->inp_vflag &
1508 						     INP_IPV4) != 0)
1509 							in6p->inp_ip_ttl = optval;
1510 					}
1511 					break;
1512 #define OPTSET(bit) \
1513 do { \
1514 	INP_WLOCK(in6p); \
1515 	if (optval) \
1516 		in6p->inp_flags |= (bit); \
1517 	else \
1518 		in6p->inp_flags &= ~(bit); \
1519 	INP_WUNLOCK(in6p); \
1520 } while (/*CONSTCOND*/ 0)
1521 #define OPTSET2292(bit) \
1522 do { \
1523 	INP_WLOCK(in6p); \
1524 	in6p->inp_flags |= IN6P_RFC2292; \
1525 	if (optval) \
1526 		in6p->inp_flags |= (bit); \
1527 	else \
1528 		in6p->inp_flags &= ~(bit); \
1529 	INP_WUNLOCK(in6p); \
1530 } while (/*CONSTCOND*/ 0)
1531 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1532 
1533 #define OPTSET2(bit, val) do {						\
1534 	INP_WLOCK(in6p);						\
1535 	if (val)							\
1536 		in6p->inp_flags2 |= bit;				\
1537 	else								\
1538 		in6p->inp_flags2 &= ~bit;				\
1539 	INP_WUNLOCK(in6p);						\
1540 } while (0)
1541 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1542 
1543 				case IPV6_RECVPKTINFO:
1544 					/* cannot mix with RFC2292 */
1545 					if (OPTBIT(IN6P_RFC2292)) {
1546 						error = EINVAL;
1547 						break;
1548 					}
1549 					OPTSET(IN6P_PKTINFO);
1550 					break;
1551 
1552 				case IPV6_HOPLIMIT:
1553 				{
1554 					struct ip6_pktopts **optp;
1555 
1556 					/* cannot mix with RFC2292 */
1557 					if (OPTBIT(IN6P_RFC2292)) {
1558 						error = EINVAL;
1559 						break;
1560 					}
1561 					optp = &in6p->in6p_outputopts;
1562 					error = ip6_pcbopt(IPV6_HOPLIMIT,
1563 					    (u_char *)&optval, sizeof(optval),
1564 					    optp, (td != NULL) ? td->td_ucred :
1565 					    NULL, uproto);
1566 					break;
1567 				}
1568 
1569 				case IPV6_RECVHOPLIMIT:
1570 					/* cannot mix with RFC2292 */
1571 					if (OPTBIT(IN6P_RFC2292)) {
1572 						error = EINVAL;
1573 						break;
1574 					}
1575 					OPTSET(IN6P_HOPLIMIT);
1576 					break;
1577 
1578 				case IPV6_RECVHOPOPTS:
1579 					/* cannot mix with RFC2292 */
1580 					if (OPTBIT(IN6P_RFC2292)) {
1581 						error = EINVAL;
1582 						break;
1583 					}
1584 					OPTSET(IN6P_HOPOPTS);
1585 					break;
1586 
1587 				case IPV6_RECVDSTOPTS:
1588 					/* cannot mix with RFC2292 */
1589 					if (OPTBIT(IN6P_RFC2292)) {
1590 						error = EINVAL;
1591 						break;
1592 					}
1593 					OPTSET(IN6P_DSTOPTS);
1594 					break;
1595 
1596 				case IPV6_RECVRTHDRDSTOPTS:
1597 					/* cannot mix with RFC2292 */
1598 					if (OPTBIT(IN6P_RFC2292)) {
1599 						error = EINVAL;
1600 						break;
1601 					}
1602 					OPTSET(IN6P_RTHDRDSTOPTS);
1603 					break;
1604 
1605 				case IPV6_RECVRTHDR:
1606 					/* cannot mix with RFC2292 */
1607 					if (OPTBIT(IN6P_RFC2292)) {
1608 						error = EINVAL;
1609 						break;
1610 					}
1611 					OPTSET(IN6P_RTHDR);
1612 					break;
1613 
1614 				case IPV6_RECVPATHMTU:
1615 					/*
1616 					 * We ignore this option for TCP
1617 					 * sockets.
1618 					 * (RFC3542 leaves this case
1619 					 * unspecified.)
1620 					 */
1621 					if (uproto != IPPROTO_TCP)
1622 						OPTSET(IN6P_MTU);
1623 					break;
1624 
1625 				case IPV6_RECVFLOWID:
1626 					OPTSET2(INP_RECVFLOWID, optval);
1627 					break;
1628 
1629 #ifdef	RSS
1630 				case IPV6_RECVRSSBUCKETID:
1631 					OPTSET2(INP_RECVRSSBUCKETID, optval);
1632 					break;
1633 #endif
1634 
1635 				case IPV6_V6ONLY:
1636 					/*
1637 					 * make setsockopt(IPV6_V6ONLY)
1638 					 * available only prior to bind(2).
1639 					 * see ipng mailing list, Jun 22 2001.
1640 					 */
1641 					if (in6p->inp_lport ||
1642 					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1643 						error = EINVAL;
1644 						break;
1645 					}
1646 					OPTSET(IN6P_IPV6_V6ONLY);
1647 					if (optval)
1648 						in6p->inp_vflag &= ~INP_IPV4;
1649 					else
1650 						in6p->inp_vflag |= INP_IPV4;
1651 					break;
1652 				case IPV6_RECVTCLASS:
1653 					/* cannot mix with RFC2292 XXX */
1654 					if (OPTBIT(IN6P_RFC2292)) {
1655 						error = EINVAL;
1656 						break;
1657 					}
1658 					OPTSET(IN6P_TCLASS);
1659 					break;
1660 				case IPV6_AUTOFLOWLABEL:
1661 					OPTSET(IN6P_AUTOFLOWLABEL);
1662 					break;
1663 
1664 				case IPV6_BINDANY:
1665 					OPTSET(INP_BINDANY);
1666 					break;
1667 
1668 				case IPV6_BINDMULTI:
1669 					OPTSET2(INP_BINDMULTI, optval);
1670 					break;
1671 #ifdef	RSS
1672 				case IPV6_RSS_LISTEN_BUCKET:
1673 					if ((optval >= 0) &&
1674 					    (optval < rss_getnumbuckets())) {
1675 						in6p->inp_rss_listen_bucket = optval;
1676 						OPTSET2(INP_RSS_BUCKET_SET, 1);
1677 					} else {
1678 						error = EINVAL;
1679 					}
1680 					break;
1681 #endif
1682 				}
1683 				break;
1684 
1685 			case IPV6_TCLASS:
1686 			case IPV6_DONTFRAG:
1687 			case IPV6_USE_MIN_MTU:
1688 			case IPV6_PREFER_TEMPADDR:
1689 				if (optlen != sizeof(optval)) {
1690 					error = EINVAL;
1691 					break;
1692 				}
1693 				error = sooptcopyin(sopt, &optval,
1694 					sizeof optval, sizeof optval);
1695 				if (error)
1696 					break;
1697 				{
1698 					struct ip6_pktopts **optp;
1699 					optp = &in6p->in6p_outputopts;
1700 					error = ip6_pcbopt(optname,
1701 					    (u_char *)&optval, sizeof(optval),
1702 					    optp, (td != NULL) ? td->td_ucred :
1703 					    NULL, uproto);
1704 					break;
1705 				}
1706 
1707 			case IPV6_2292PKTINFO:
1708 			case IPV6_2292HOPLIMIT:
1709 			case IPV6_2292HOPOPTS:
1710 			case IPV6_2292DSTOPTS:
1711 			case IPV6_2292RTHDR:
1712 				/* RFC 2292 */
1713 				if (optlen != sizeof(int)) {
1714 					error = EINVAL;
1715 					break;
1716 				}
1717 				error = sooptcopyin(sopt, &optval,
1718 					sizeof optval, sizeof optval);
1719 				if (error)
1720 					break;
1721 				switch (optname) {
1722 				case IPV6_2292PKTINFO:
1723 					OPTSET2292(IN6P_PKTINFO);
1724 					break;
1725 				case IPV6_2292HOPLIMIT:
1726 					OPTSET2292(IN6P_HOPLIMIT);
1727 					break;
1728 				case IPV6_2292HOPOPTS:
1729 					/*
1730 					 * Check super-user privilege.
1731 					 * See comments for IPV6_RECVHOPOPTS.
1732 					 */
1733 					if (td != NULL) {
1734 						error = priv_check(td,
1735 						    PRIV_NETINET_SETHDROPTS);
1736 						if (error)
1737 							return (error);
1738 					}
1739 					OPTSET2292(IN6P_HOPOPTS);
1740 					break;
1741 				case IPV6_2292DSTOPTS:
1742 					if (td != NULL) {
1743 						error = priv_check(td,
1744 						    PRIV_NETINET_SETHDROPTS);
1745 						if (error)
1746 							return (error);
1747 					}
1748 					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1749 					break;
1750 				case IPV6_2292RTHDR:
1751 					OPTSET2292(IN6P_RTHDR);
1752 					break;
1753 				}
1754 				break;
1755 			case IPV6_PKTINFO:
1756 			case IPV6_HOPOPTS:
1757 			case IPV6_RTHDR:
1758 			case IPV6_DSTOPTS:
1759 			case IPV6_RTHDRDSTOPTS:
1760 			case IPV6_NEXTHOP:
1761 			{
1762 				/* new advanced API (RFC3542) */
1763 				u_char *optbuf;
1764 				u_char optbuf_storage[MCLBYTES];
1765 				int optlen;
1766 				struct ip6_pktopts **optp;
1767 
1768 				/* cannot mix with RFC2292 */
1769 				if (OPTBIT(IN6P_RFC2292)) {
1770 					error = EINVAL;
1771 					break;
1772 				}
1773 
1774 				/*
1775 				 * We only ensure valsize is not too large
1776 				 * here.  Further validation will be done
1777 				 * later.
1778 				 */
1779 				error = sooptcopyin(sopt, optbuf_storage,
1780 				    sizeof(optbuf_storage), 0);
1781 				if (error)
1782 					break;
1783 				optlen = sopt->sopt_valsize;
1784 				optbuf = optbuf_storage;
1785 				optp = &in6p->in6p_outputopts;
1786 				error = ip6_pcbopt(optname, optbuf, optlen,
1787 				    optp, (td != NULL) ? td->td_ucred : NULL,
1788 				    uproto);
1789 				break;
1790 			}
1791 #undef OPTSET
1792 
1793 			case IPV6_MULTICAST_IF:
1794 			case IPV6_MULTICAST_HOPS:
1795 			case IPV6_MULTICAST_LOOP:
1796 			case IPV6_JOIN_GROUP:
1797 			case IPV6_LEAVE_GROUP:
1798 			case IPV6_MSFILTER:
1799 			case MCAST_BLOCK_SOURCE:
1800 			case MCAST_UNBLOCK_SOURCE:
1801 			case MCAST_JOIN_GROUP:
1802 			case MCAST_LEAVE_GROUP:
1803 			case MCAST_JOIN_SOURCE_GROUP:
1804 			case MCAST_LEAVE_SOURCE_GROUP:
1805 				error = ip6_setmoptions(in6p, sopt);
1806 				break;
1807 
1808 			case IPV6_PORTRANGE:
1809 				error = sooptcopyin(sopt, &optval,
1810 				    sizeof optval, sizeof optval);
1811 				if (error)
1812 					break;
1813 
1814 				INP_WLOCK(in6p);
1815 				switch (optval) {
1816 				case IPV6_PORTRANGE_DEFAULT:
1817 					in6p->inp_flags &= ~(INP_LOWPORT);
1818 					in6p->inp_flags &= ~(INP_HIGHPORT);
1819 					break;
1820 
1821 				case IPV6_PORTRANGE_HIGH:
1822 					in6p->inp_flags &= ~(INP_LOWPORT);
1823 					in6p->inp_flags |= INP_HIGHPORT;
1824 					break;
1825 
1826 				case IPV6_PORTRANGE_LOW:
1827 					in6p->inp_flags &= ~(INP_HIGHPORT);
1828 					in6p->inp_flags |= INP_LOWPORT;
1829 					break;
1830 
1831 				default:
1832 					error = EINVAL;
1833 					break;
1834 				}
1835 				INP_WUNLOCK(in6p);
1836 				break;
1837 
1838 #ifdef IPSEC
1839 			case IPV6_IPSEC_POLICY:
1840 			{
1841 				caddr_t req;
1842 				struct mbuf *m;
1843 
1844 				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1845 					break;
1846 				if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1847 					break;
1848 				req = mtod(m, caddr_t);
1849 				error = ipsec_set_policy(in6p, optname, req,
1850 				    m->m_len, (sopt->sopt_td != NULL) ?
1851 				    sopt->sopt_td->td_ucred : NULL);
1852 				m_freem(m);
1853 				break;
1854 			}
1855 #endif /* IPSEC */
1856 
1857 			default:
1858 				error = ENOPROTOOPT;
1859 				break;
1860 			}
1861 			break;
1862 
1863 		case SOPT_GET:
1864 			switch (optname) {
1865 
1866 			case IPV6_2292PKTOPTIONS:
1867 #ifdef IPV6_PKTOPTIONS
1868 			case IPV6_PKTOPTIONS:
1869 #endif
1870 				/*
1871 				 * RFC3542 (effectively) deprecated the
1872 				 * semantics of the 2292-style pktoptions.
1873 				 * Since it was not reliable in nature (i.e.,
1874 				 * applications had to expect the lack of some
1875 				 * information after all), it would make sense
1876 				 * to simplify this part by always returning
1877 				 * empty data.
1878 				 */
1879 				sopt->sopt_valsize = 0;
1880 				break;
1881 
1882 			case IPV6_RECVHOPOPTS:
1883 			case IPV6_RECVDSTOPTS:
1884 			case IPV6_RECVRTHDRDSTOPTS:
1885 			case IPV6_UNICAST_HOPS:
1886 			case IPV6_RECVPKTINFO:
1887 			case IPV6_RECVHOPLIMIT:
1888 			case IPV6_RECVRTHDR:
1889 			case IPV6_RECVPATHMTU:
1890 
1891 			case IPV6_V6ONLY:
1892 			case IPV6_PORTRANGE:
1893 			case IPV6_RECVTCLASS:
1894 			case IPV6_AUTOFLOWLABEL:
1895 			case IPV6_BINDANY:
1896 			case IPV6_FLOWID:
1897 			case IPV6_FLOWTYPE:
1898 			case IPV6_RECVFLOWID:
1899 #ifdef	RSS
1900 			case IPV6_RSSBUCKETID:
1901 			case IPV6_RECVRSSBUCKETID:
1902 #endif
1903 			case IPV6_BINDMULTI:
1904 				switch (optname) {
1905 
1906 				case IPV6_RECVHOPOPTS:
1907 					optval = OPTBIT(IN6P_HOPOPTS);
1908 					break;
1909 
1910 				case IPV6_RECVDSTOPTS:
1911 					optval = OPTBIT(IN6P_DSTOPTS);
1912 					break;
1913 
1914 				case IPV6_RECVRTHDRDSTOPTS:
1915 					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1916 					break;
1917 
1918 				case IPV6_UNICAST_HOPS:
1919 					optval = in6p->in6p_hops;
1920 					break;
1921 
1922 				case IPV6_RECVPKTINFO:
1923 					optval = OPTBIT(IN6P_PKTINFO);
1924 					break;
1925 
1926 				case IPV6_RECVHOPLIMIT:
1927 					optval = OPTBIT(IN6P_HOPLIMIT);
1928 					break;
1929 
1930 				case IPV6_RECVRTHDR:
1931 					optval = OPTBIT(IN6P_RTHDR);
1932 					break;
1933 
1934 				case IPV6_RECVPATHMTU:
1935 					optval = OPTBIT(IN6P_MTU);
1936 					break;
1937 
1938 				case IPV6_V6ONLY:
1939 					optval = OPTBIT(IN6P_IPV6_V6ONLY);
1940 					break;
1941 
1942 				case IPV6_PORTRANGE:
1943 				    {
1944 					int flags;
1945 					flags = in6p->inp_flags;
1946 					if (flags & INP_HIGHPORT)
1947 						optval = IPV6_PORTRANGE_HIGH;
1948 					else if (flags & INP_LOWPORT)
1949 						optval = IPV6_PORTRANGE_LOW;
1950 					else
1951 						optval = 0;
1952 					break;
1953 				    }
1954 				case IPV6_RECVTCLASS:
1955 					optval = OPTBIT(IN6P_TCLASS);
1956 					break;
1957 
1958 				case IPV6_AUTOFLOWLABEL:
1959 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1960 					break;
1961 
1962 				case IPV6_BINDANY:
1963 					optval = OPTBIT(INP_BINDANY);
1964 					break;
1965 
1966 				case IPV6_FLOWID:
1967 					optval = in6p->inp_flowid;
1968 					break;
1969 
1970 				case IPV6_FLOWTYPE:
1971 					optval = in6p->inp_flowtype;
1972 					break;
1973 
1974 				case IPV6_RECVFLOWID:
1975 					optval = OPTBIT2(INP_RECVFLOWID);
1976 					break;
1977 #ifdef	RSS
1978 				case IPV6_RSSBUCKETID:
1979 					retval =
1980 					    rss_hash2bucket(in6p->inp_flowid,
1981 					    in6p->inp_flowtype,
1982 					    &rss_bucket);
1983 					if (retval == 0)
1984 						optval = rss_bucket;
1985 					else
1986 						error = EINVAL;
1987 					break;
1988 
1989 				case IPV6_RECVRSSBUCKETID:
1990 					optval = OPTBIT2(INP_RECVRSSBUCKETID);
1991 					break;
1992 #endif
1993 
1994 				case IPV6_BINDMULTI:
1995 					optval = OPTBIT2(INP_BINDMULTI);
1996 					break;
1997 
1998 				}
1999 				if (error)
2000 					break;
2001 				error = sooptcopyout(sopt, &optval,
2002 					sizeof optval);
2003 				break;
2004 
2005 			case IPV6_PATHMTU:
2006 			{
2007 				u_long pmtu = 0;
2008 				struct ip6_mtuinfo mtuinfo;
2009 
2010 				if (!(so->so_state & SS_ISCONNECTED))
2011 					return (ENOTCONN);
2012 				/*
2013 				 * XXX: we dot not consider the case of source
2014 				 * routing, or optional information to specify
2015 				 * the outgoing interface.
2016 				 */
2017 				error = ip6_getpmtu_ctl(so->so_fibnum,
2018 				    &in6p->in6p_faddr, &pmtu);
2019 				if (error)
2020 					break;
2021 				if (pmtu > IPV6_MAXPACKET)
2022 					pmtu = IPV6_MAXPACKET;
2023 
2024 				bzero(&mtuinfo, sizeof(mtuinfo));
2025 				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2026 				optdata = (void *)&mtuinfo;
2027 				optdatalen = sizeof(mtuinfo);
2028 				error = sooptcopyout(sopt, optdata,
2029 				    optdatalen);
2030 				break;
2031 			}
2032 
2033 			case IPV6_2292PKTINFO:
2034 			case IPV6_2292HOPLIMIT:
2035 			case IPV6_2292HOPOPTS:
2036 			case IPV6_2292RTHDR:
2037 			case IPV6_2292DSTOPTS:
2038 				switch (optname) {
2039 				case IPV6_2292PKTINFO:
2040 					optval = OPTBIT(IN6P_PKTINFO);
2041 					break;
2042 				case IPV6_2292HOPLIMIT:
2043 					optval = OPTBIT(IN6P_HOPLIMIT);
2044 					break;
2045 				case IPV6_2292HOPOPTS:
2046 					optval = OPTBIT(IN6P_HOPOPTS);
2047 					break;
2048 				case IPV6_2292RTHDR:
2049 					optval = OPTBIT(IN6P_RTHDR);
2050 					break;
2051 				case IPV6_2292DSTOPTS:
2052 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2053 					break;
2054 				}
2055 				error = sooptcopyout(sopt, &optval,
2056 				    sizeof optval);
2057 				break;
2058 			case IPV6_PKTINFO:
2059 			case IPV6_HOPOPTS:
2060 			case IPV6_RTHDR:
2061 			case IPV6_DSTOPTS:
2062 			case IPV6_RTHDRDSTOPTS:
2063 			case IPV6_NEXTHOP:
2064 			case IPV6_TCLASS:
2065 			case IPV6_DONTFRAG:
2066 			case IPV6_USE_MIN_MTU:
2067 			case IPV6_PREFER_TEMPADDR:
2068 				error = ip6_getpcbopt(in6p->in6p_outputopts,
2069 				    optname, sopt);
2070 				break;
2071 
2072 			case IPV6_MULTICAST_IF:
2073 			case IPV6_MULTICAST_HOPS:
2074 			case IPV6_MULTICAST_LOOP:
2075 			case IPV6_MSFILTER:
2076 				error = ip6_getmoptions(in6p, sopt);
2077 				break;
2078 
2079 #ifdef IPSEC
2080 			case IPV6_IPSEC_POLICY:
2081 			  {
2082 				caddr_t req = NULL;
2083 				size_t len = 0;
2084 				struct mbuf *m = NULL;
2085 				struct mbuf **mp = &m;
2086 				size_t ovalsize = sopt->sopt_valsize;
2087 				caddr_t oval = (caddr_t)sopt->sopt_val;
2088 
2089 				error = soopt_getm(sopt, &m); /* XXX */
2090 				if (error != 0)
2091 					break;
2092 				error = soopt_mcopyin(sopt, m); /* XXX */
2093 				if (error != 0)
2094 					break;
2095 				sopt->sopt_valsize = ovalsize;
2096 				sopt->sopt_val = oval;
2097 				if (m) {
2098 					req = mtod(m, caddr_t);
2099 					len = m->m_len;
2100 				}
2101 				error = ipsec_get_policy(in6p, req, len, mp);
2102 				if (error == 0)
2103 					error = soopt_mcopyout(sopt, m); /* XXX */
2104 				if (error == 0 && m)
2105 					m_freem(m);
2106 				break;
2107 			  }
2108 #endif /* IPSEC */
2109 
2110 			default:
2111 				error = ENOPROTOOPT;
2112 				break;
2113 			}
2114 			break;
2115 		}
2116 	}
2117 	return (error);
2118 }
2119 
2120 int
2121 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2122 {
2123 	int error = 0, optval, optlen;
2124 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2125 	struct inpcb *in6p = sotoinpcb(so);
2126 	int level, op, optname;
2127 
2128 	level = sopt->sopt_level;
2129 	op = sopt->sopt_dir;
2130 	optname = sopt->sopt_name;
2131 	optlen = sopt->sopt_valsize;
2132 
2133 	if (level != IPPROTO_IPV6) {
2134 		return (EINVAL);
2135 	}
2136 
2137 	switch (optname) {
2138 	case IPV6_CHECKSUM:
2139 		/*
2140 		 * For ICMPv6 sockets, no modification allowed for checksum
2141 		 * offset, permit "no change" values to help existing apps.
2142 		 *
2143 		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2144 		 * for an ICMPv6 socket will fail."
2145 		 * The current behavior does not meet RFC3542.
2146 		 */
2147 		switch (op) {
2148 		case SOPT_SET:
2149 			if (optlen != sizeof(int)) {
2150 				error = EINVAL;
2151 				break;
2152 			}
2153 			error = sooptcopyin(sopt, &optval, sizeof(optval),
2154 					    sizeof(optval));
2155 			if (error)
2156 				break;
2157 			if ((optval % 2) != 0) {
2158 				/* the API assumes even offset values */
2159 				error = EINVAL;
2160 			} else if (so->so_proto->pr_protocol ==
2161 			    IPPROTO_ICMPV6) {
2162 				if (optval != icmp6off)
2163 					error = EINVAL;
2164 			} else
2165 				in6p->in6p_cksum = optval;
2166 			break;
2167 
2168 		case SOPT_GET:
2169 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2170 				optval = icmp6off;
2171 			else
2172 				optval = in6p->in6p_cksum;
2173 
2174 			error = sooptcopyout(sopt, &optval, sizeof(optval));
2175 			break;
2176 
2177 		default:
2178 			error = EINVAL;
2179 			break;
2180 		}
2181 		break;
2182 
2183 	default:
2184 		error = ENOPROTOOPT;
2185 		break;
2186 	}
2187 
2188 	return (error);
2189 }
2190 
2191 /*
2192  * Set up IP6 options in pcb for insertion in output packets or
2193  * specifying behavior of outgoing packets.
2194  */
2195 static int
2196 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2197     struct socket *so, struct sockopt *sopt)
2198 {
2199 	struct ip6_pktopts *opt = *pktopt;
2200 	int error = 0;
2201 	struct thread *td = sopt->sopt_td;
2202 
2203 	/* turn off any old options. */
2204 	if (opt) {
2205 #ifdef DIAGNOSTIC
2206 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2207 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2208 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2209 			printf("ip6_pcbopts: all specified options are cleared.\n");
2210 #endif
2211 		ip6_clearpktopts(opt, -1);
2212 	} else
2213 		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2214 	*pktopt = NULL;
2215 
2216 	if (!m || m->m_len == 0) {
2217 		/*
2218 		 * Only turning off any previous options, regardless of
2219 		 * whether the opt is just created or given.
2220 		 */
2221 		free(opt, M_IP6OPT);
2222 		return (0);
2223 	}
2224 
2225 	/*  set options specified by user. */
2226 	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2227 	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2228 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2229 		free(opt, M_IP6OPT);
2230 		return (error);
2231 	}
2232 	*pktopt = opt;
2233 	return (0);
2234 }
2235 
2236 /*
2237  * initialize ip6_pktopts.  beware that there are non-zero default values in
2238  * the struct.
2239  */
2240 void
2241 ip6_initpktopts(struct ip6_pktopts *opt)
2242 {
2243 
2244 	bzero(opt, sizeof(*opt));
2245 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2246 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2247 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2248 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2249 }
2250 
2251 static int
2252 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2253     struct ucred *cred, int uproto)
2254 {
2255 	struct ip6_pktopts *opt;
2256 
2257 	if (*pktopt == NULL) {
2258 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2259 		    M_WAITOK);
2260 		ip6_initpktopts(*pktopt);
2261 	}
2262 	opt = *pktopt;
2263 
2264 	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2265 }
2266 
2267 static int
2268 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2269 {
2270 	void *optdata = NULL;
2271 	int optdatalen = 0;
2272 	struct ip6_ext *ip6e;
2273 	int error = 0;
2274 	struct in6_pktinfo null_pktinfo;
2275 	int deftclass = 0, on;
2276 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2277 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2278 
2279 	switch (optname) {
2280 	case IPV6_PKTINFO:
2281 		optdata = (void *)&null_pktinfo;
2282 		if (pktopt && pktopt->ip6po_pktinfo) {
2283 			bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2284 			    sizeof(null_pktinfo));
2285 			in6_clearscope(&null_pktinfo.ipi6_addr);
2286 		} else {
2287 			/* XXX: we don't have to do this every time... */
2288 			bzero(&null_pktinfo, sizeof(null_pktinfo));
2289 		}
2290 		optdatalen = sizeof(struct in6_pktinfo);
2291 		break;
2292 	case IPV6_TCLASS:
2293 		if (pktopt && pktopt->ip6po_tclass >= 0)
2294 			optdata = (void *)&pktopt->ip6po_tclass;
2295 		else
2296 			optdata = (void *)&deftclass;
2297 		optdatalen = sizeof(int);
2298 		break;
2299 	case IPV6_HOPOPTS:
2300 		if (pktopt && pktopt->ip6po_hbh) {
2301 			optdata = (void *)pktopt->ip6po_hbh;
2302 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2303 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2304 		}
2305 		break;
2306 	case IPV6_RTHDR:
2307 		if (pktopt && pktopt->ip6po_rthdr) {
2308 			optdata = (void *)pktopt->ip6po_rthdr;
2309 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2310 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2311 		}
2312 		break;
2313 	case IPV6_RTHDRDSTOPTS:
2314 		if (pktopt && pktopt->ip6po_dest1) {
2315 			optdata = (void *)pktopt->ip6po_dest1;
2316 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2317 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2318 		}
2319 		break;
2320 	case IPV6_DSTOPTS:
2321 		if (pktopt && pktopt->ip6po_dest2) {
2322 			optdata = (void *)pktopt->ip6po_dest2;
2323 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2324 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2325 		}
2326 		break;
2327 	case IPV6_NEXTHOP:
2328 		if (pktopt && pktopt->ip6po_nexthop) {
2329 			optdata = (void *)pktopt->ip6po_nexthop;
2330 			optdatalen = pktopt->ip6po_nexthop->sa_len;
2331 		}
2332 		break;
2333 	case IPV6_USE_MIN_MTU:
2334 		if (pktopt)
2335 			optdata = (void *)&pktopt->ip6po_minmtu;
2336 		else
2337 			optdata = (void *)&defminmtu;
2338 		optdatalen = sizeof(int);
2339 		break;
2340 	case IPV6_DONTFRAG:
2341 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2342 			on = 1;
2343 		else
2344 			on = 0;
2345 		optdata = (void *)&on;
2346 		optdatalen = sizeof(on);
2347 		break;
2348 	case IPV6_PREFER_TEMPADDR:
2349 		if (pktopt)
2350 			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2351 		else
2352 			optdata = (void *)&defpreftemp;
2353 		optdatalen = sizeof(int);
2354 		break;
2355 	default:		/* should not happen */
2356 #ifdef DIAGNOSTIC
2357 		panic("ip6_getpcbopt: unexpected option\n");
2358 #endif
2359 		return (ENOPROTOOPT);
2360 	}
2361 
2362 	error = sooptcopyout(sopt, optdata, optdatalen);
2363 
2364 	return (error);
2365 }
2366 
2367 void
2368 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2369 {
2370 	if (pktopt == NULL)
2371 		return;
2372 
2373 	if (optname == -1 || optname == IPV6_PKTINFO) {
2374 		if (pktopt->ip6po_pktinfo)
2375 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2376 		pktopt->ip6po_pktinfo = NULL;
2377 	}
2378 	if (optname == -1 || optname == IPV6_HOPLIMIT)
2379 		pktopt->ip6po_hlim = -1;
2380 	if (optname == -1 || optname == IPV6_TCLASS)
2381 		pktopt->ip6po_tclass = -1;
2382 	if (optname == -1 || optname == IPV6_NEXTHOP) {
2383 		if (pktopt->ip6po_nextroute.ro_rt) {
2384 			RTFREE(pktopt->ip6po_nextroute.ro_rt);
2385 			pktopt->ip6po_nextroute.ro_rt = NULL;
2386 		}
2387 		if (pktopt->ip6po_nexthop)
2388 			free(pktopt->ip6po_nexthop, M_IP6OPT);
2389 		pktopt->ip6po_nexthop = NULL;
2390 	}
2391 	if (optname == -1 || optname == IPV6_HOPOPTS) {
2392 		if (pktopt->ip6po_hbh)
2393 			free(pktopt->ip6po_hbh, M_IP6OPT);
2394 		pktopt->ip6po_hbh = NULL;
2395 	}
2396 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2397 		if (pktopt->ip6po_dest1)
2398 			free(pktopt->ip6po_dest1, M_IP6OPT);
2399 		pktopt->ip6po_dest1 = NULL;
2400 	}
2401 	if (optname == -1 || optname == IPV6_RTHDR) {
2402 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2403 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2404 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2405 		if (pktopt->ip6po_route.ro_rt) {
2406 			RTFREE(pktopt->ip6po_route.ro_rt);
2407 			pktopt->ip6po_route.ro_rt = NULL;
2408 		}
2409 	}
2410 	if (optname == -1 || optname == IPV6_DSTOPTS) {
2411 		if (pktopt->ip6po_dest2)
2412 			free(pktopt->ip6po_dest2, M_IP6OPT);
2413 		pktopt->ip6po_dest2 = NULL;
2414 	}
2415 }
2416 
2417 #define PKTOPT_EXTHDRCPY(type) \
2418 do {\
2419 	if (src->type) {\
2420 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2421 		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2422 		if (dst->type == NULL && canwait == M_NOWAIT)\
2423 			goto bad;\
2424 		bcopy(src->type, dst->type, hlen);\
2425 	}\
2426 } while (/*CONSTCOND*/ 0)
2427 
2428 static int
2429 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2430 {
2431 	if (dst == NULL || src == NULL)  {
2432 		printf("ip6_clearpktopts: invalid argument\n");
2433 		return (EINVAL);
2434 	}
2435 
2436 	dst->ip6po_hlim = src->ip6po_hlim;
2437 	dst->ip6po_tclass = src->ip6po_tclass;
2438 	dst->ip6po_flags = src->ip6po_flags;
2439 	dst->ip6po_minmtu = src->ip6po_minmtu;
2440 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2441 	if (src->ip6po_pktinfo) {
2442 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2443 		    M_IP6OPT, canwait);
2444 		if (dst->ip6po_pktinfo == NULL)
2445 			goto bad;
2446 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2447 	}
2448 	if (src->ip6po_nexthop) {
2449 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2450 		    M_IP6OPT, canwait);
2451 		if (dst->ip6po_nexthop == NULL)
2452 			goto bad;
2453 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2454 		    src->ip6po_nexthop->sa_len);
2455 	}
2456 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2457 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2458 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2459 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2460 	return (0);
2461 
2462   bad:
2463 	ip6_clearpktopts(dst, -1);
2464 	return (ENOBUFS);
2465 }
2466 #undef PKTOPT_EXTHDRCPY
2467 
2468 struct ip6_pktopts *
2469 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2470 {
2471 	int error;
2472 	struct ip6_pktopts *dst;
2473 
2474 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2475 	if (dst == NULL)
2476 		return (NULL);
2477 	ip6_initpktopts(dst);
2478 
2479 	if ((error = copypktopts(dst, src, canwait)) != 0) {
2480 		free(dst, M_IP6OPT);
2481 		return (NULL);
2482 	}
2483 
2484 	return (dst);
2485 }
2486 
2487 void
2488 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2489 {
2490 	if (pktopt == NULL)
2491 		return;
2492 
2493 	ip6_clearpktopts(pktopt, -1);
2494 
2495 	free(pktopt, M_IP6OPT);
2496 }
2497 
2498 /*
2499  * Set IPv6 outgoing packet options based on advanced API.
2500  */
2501 int
2502 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2503     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2504 {
2505 	struct cmsghdr *cm = 0;
2506 
2507 	if (control == NULL || opt == NULL)
2508 		return (EINVAL);
2509 
2510 	ip6_initpktopts(opt);
2511 	if (stickyopt) {
2512 		int error;
2513 
2514 		/*
2515 		 * If stickyopt is provided, make a local copy of the options
2516 		 * for this particular packet, then override them by ancillary
2517 		 * objects.
2518 		 * XXX: copypktopts() does not copy the cached route to a next
2519 		 * hop (if any).  This is not very good in terms of efficiency,
2520 		 * but we can allow this since this option should be rarely
2521 		 * used.
2522 		 */
2523 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2524 			return (error);
2525 	}
2526 
2527 	/*
2528 	 * XXX: Currently, we assume all the optional information is stored
2529 	 * in a single mbuf.
2530 	 */
2531 	if (control->m_next)
2532 		return (EINVAL);
2533 
2534 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2535 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2536 		int error;
2537 
2538 		if (control->m_len < CMSG_LEN(0))
2539 			return (EINVAL);
2540 
2541 		cm = mtod(control, struct cmsghdr *);
2542 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2543 			return (EINVAL);
2544 		if (cm->cmsg_level != IPPROTO_IPV6)
2545 			continue;
2546 
2547 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2548 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2549 		if (error)
2550 			return (error);
2551 	}
2552 
2553 	return (0);
2554 }
2555 
2556 /*
2557  * Set a particular packet option, as a sticky option or an ancillary data
2558  * item.  "len" can be 0 only when it's a sticky option.
2559  * We have 4 cases of combination of "sticky" and "cmsg":
2560  * "sticky=0, cmsg=0": impossible
2561  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2562  * "sticky=1, cmsg=0": RFC3542 socket option
2563  * "sticky=1, cmsg=1": RFC2292 socket option
2564  */
2565 static int
2566 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2567     struct ucred *cred, int sticky, int cmsg, int uproto)
2568 {
2569 	int minmtupolicy, preftemp;
2570 	int error;
2571 
2572 	if (!sticky && !cmsg) {
2573 #ifdef DIAGNOSTIC
2574 		printf("ip6_setpktopt: impossible case\n");
2575 #endif
2576 		return (EINVAL);
2577 	}
2578 
2579 	/*
2580 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2581 	 * not be specified in the context of RFC3542.  Conversely,
2582 	 * RFC3542 types should not be specified in the context of RFC2292.
2583 	 */
2584 	if (!cmsg) {
2585 		switch (optname) {
2586 		case IPV6_2292PKTINFO:
2587 		case IPV6_2292HOPLIMIT:
2588 		case IPV6_2292NEXTHOP:
2589 		case IPV6_2292HOPOPTS:
2590 		case IPV6_2292DSTOPTS:
2591 		case IPV6_2292RTHDR:
2592 		case IPV6_2292PKTOPTIONS:
2593 			return (ENOPROTOOPT);
2594 		}
2595 	}
2596 	if (sticky && cmsg) {
2597 		switch (optname) {
2598 		case IPV6_PKTINFO:
2599 		case IPV6_HOPLIMIT:
2600 		case IPV6_NEXTHOP:
2601 		case IPV6_HOPOPTS:
2602 		case IPV6_DSTOPTS:
2603 		case IPV6_RTHDRDSTOPTS:
2604 		case IPV6_RTHDR:
2605 		case IPV6_USE_MIN_MTU:
2606 		case IPV6_DONTFRAG:
2607 		case IPV6_TCLASS:
2608 		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2609 			return (ENOPROTOOPT);
2610 		}
2611 	}
2612 
2613 	switch (optname) {
2614 	case IPV6_2292PKTINFO:
2615 	case IPV6_PKTINFO:
2616 	{
2617 		struct ifnet *ifp = NULL;
2618 		struct in6_pktinfo *pktinfo;
2619 
2620 		if (len != sizeof(struct in6_pktinfo))
2621 			return (EINVAL);
2622 
2623 		pktinfo = (struct in6_pktinfo *)buf;
2624 
2625 		/*
2626 		 * An application can clear any sticky IPV6_PKTINFO option by
2627 		 * doing a "regular" setsockopt with ipi6_addr being
2628 		 * in6addr_any and ipi6_ifindex being zero.
2629 		 * [RFC 3542, Section 6]
2630 		 */
2631 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2632 		    pktinfo->ipi6_ifindex == 0 &&
2633 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2634 			ip6_clearpktopts(opt, optname);
2635 			break;
2636 		}
2637 
2638 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2639 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2640 			return (EINVAL);
2641 		}
2642 		if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2643 			return (EINVAL);
2644 		/* validate the interface index if specified. */
2645 		if (pktinfo->ipi6_ifindex > V_if_index)
2646 			 return (ENXIO);
2647 		if (pktinfo->ipi6_ifindex) {
2648 			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2649 			if (ifp == NULL)
2650 				return (ENXIO);
2651 		}
2652 		if (ifp != NULL && (
2653 		    ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED))
2654 			return (ENETDOWN);
2655 
2656 		if (ifp != NULL &&
2657 		    !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2658 			struct in6_ifaddr *ia;
2659 
2660 			in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2661 			ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2662 			if (ia == NULL)
2663 				return (EADDRNOTAVAIL);
2664 			ifa_free(&ia->ia_ifa);
2665 		}
2666 		/*
2667 		 * We store the address anyway, and let in6_selectsrc()
2668 		 * validate the specified address.  This is because ipi6_addr
2669 		 * may not have enough information about its scope zone, and
2670 		 * we may need additional information (such as outgoing
2671 		 * interface or the scope zone of a destination address) to
2672 		 * disambiguate the scope.
2673 		 * XXX: the delay of the validation may confuse the
2674 		 * application when it is used as a sticky option.
2675 		 */
2676 		if (opt->ip6po_pktinfo == NULL) {
2677 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2678 			    M_IP6OPT, M_NOWAIT);
2679 			if (opt->ip6po_pktinfo == NULL)
2680 				return (ENOBUFS);
2681 		}
2682 		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2683 		break;
2684 	}
2685 
2686 	case IPV6_2292HOPLIMIT:
2687 	case IPV6_HOPLIMIT:
2688 	{
2689 		int *hlimp;
2690 
2691 		/*
2692 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2693 		 * to simplify the ordering among hoplimit options.
2694 		 */
2695 		if (optname == IPV6_HOPLIMIT && sticky)
2696 			return (ENOPROTOOPT);
2697 
2698 		if (len != sizeof(int))
2699 			return (EINVAL);
2700 		hlimp = (int *)buf;
2701 		if (*hlimp < -1 || *hlimp > 255)
2702 			return (EINVAL);
2703 
2704 		opt->ip6po_hlim = *hlimp;
2705 		break;
2706 	}
2707 
2708 	case IPV6_TCLASS:
2709 	{
2710 		int tclass;
2711 
2712 		if (len != sizeof(int))
2713 			return (EINVAL);
2714 		tclass = *(int *)buf;
2715 		if (tclass < -1 || tclass > 255)
2716 			return (EINVAL);
2717 
2718 		opt->ip6po_tclass = tclass;
2719 		break;
2720 	}
2721 
2722 	case IPV6_2292NEXTHOP:
2723 	case IPV6_NEXTHOP:
2724 		if (cred != NULL) {
2725 			error = priv_check_cred(cred,
2726 			    PRIV_NETINET_SETHDROPTS, 0);
2727 			if (error)
2728 				return (error);
2729 		}
2730 
2731 		if (len == 0) {	/* just remove the option */
2732 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
2733 			break;
2734 		}
2735 
2736 		/* check if cmsg_len is large enough for sa_len */
2737 		if (len < sizeof(struct sockaddr) || len < *buf)
2738 			return (EINVAL);
2739 
2740 		switch (((struct sockaddr *)buf)->sa_family) {
2741 		case AF_INET6:
2742 		{
2743 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2744 			int error;
2745 
2746 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2747 				return (EINVAL);
2748 
2749 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2750 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2751 				return (EINVAL);
2752 			}
2753 			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2754 			    != 0) {
2755 				return (error);
2756 			}
2757 			break;
2758 		}
2759 		case AF_LINK:	/* should eventually be supported */
2760 		default:
2761 			return (EAFNOSUPPORT);
2762 		}
2763 
2764 		/* turn off the previous option, then set the new option. */
2765 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
2766 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2767 		if (opt->ip6po_nexthop == NULL)
2768 			return (ENOBUFS);
2769 		bcopy(buf, opt->ip6po_nexthop, *buf);
2770 		break;
2771 
2772 	case IPV6_2292HOPOPTS:
2773 	case IPV6_HOPOPTS:
2774 	{
2775 		struct ip6_hbh *hbh;
2776 		int hbhlen;
2777 
2778 		/*
2779 		 * XXX: We don't allow a non-privileged user to set ANY HbH
2780 		 * options, since per-option restriction has too much
2781 		 * overhead.
2782 		 */
2783 		if (cred != NULL) {
2784 			error = priv_check_cred(cred,
2785 			    PRIV_NETINET_SETHDROPTS, 0);
2786 			if (error)
2787 				return (error);
2788 		}
2789 
2790 		if (len == 0) {
2791 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
2792 			break;	/* just remove the option */
2793 		}
2794 
2795 		/* message length validation */
2796 		if (len < sizeof(struct ip6_hbh))
2797 			return (EINVAL);
2798 		hbh = (struct ip6_hbh *)buf;
2799 		hbhlen = (hbh->ip6h_len + 1) << 3;
2800 		if (len != hbhlen)
2801 			return (EINVAL);
2802 
2803 		/* turn off the previous option, then set the new option. */
2804 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
2805 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2806 		if (opt->ip6po_hbh == NULL)
2807 			return (ENOBUFS);
2808 		bcopy(hbh, opt->ip6po_hbh, hbhlen);
2809 
2810 		break;
2811 	}
2812 
2813 	case IPV6_2292DSTOPTS:
2814 	case IPV6_DSTOPTS:
2815 	case IPV6_RTHDRDSTOPTS:
2816 	{
2817 		struct ip6_dest *dest, **newdest = NULL;
2818 		int destlen;
2819 
2820 		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2821 			error = priv_check_cred(cred,
2822 			    PRIV_NETINET_SETHDROPTS, 0);
2823 			if (error)
2824 				return (error);
2825 		}
2826 
2827 		if (len == 0) {
2828 			ip6_clearpktopts(opt, optname);
2829 			break;	/* just remove the option */
2830 		}
2831 
2832 		/* message length validation */
2833 		if (len < sizeof(struct ip6_dest))
2834 			return (EINVAL);
2835 		dest = (struct ip6_dest *)buf;
2836 		destlen = (dest->ip6d_len + 1) << 3;
2837 		if (len != destlen)
2838 			return (EINVAL);
2839 
2840 		/*
2841 		 * Determine the position that the destination options header
2842 		 * should be inserted; before or after the routing header.
2843 		 */
2844 		switch (optname) {
2845 		case IPV6_2292DSTOPTS:
2846 			/*
2847 			 * The old advacned API is ambiguous on this point.
2848 			 * Our approach is to determine the position based
2849 			 * according to the existence of a routing header.
2850 			 * Note, however, that this depends on the order of the
2851 			 * extension headers in the ancillary data; the 1st
2852 			 * part of the destination options header must appear
2853 			 * before the routing header in the ancillary data,
2854 			 * too.
2855 			 * RFC3542 solved the ambiguity by introducing
2856 			 * separate ancillary data or option types.
2857 			 */
2858 			if (opt->ip6po_rthdr == NULL)
2859 				newdest = &opt->ip6po_dest1;
2860 			else
2861 				newdest = &opt->ip6po_dest2;
2862 			break;
2863 		case IPV6_RTHDRDSTOPTS:
2864 			newdest = &opt->ip6po_dest1;
2865 			break;
2866 		case IPV6_DSTOPTS:
2867 			newdest = &opt->ip6po_dest2;
2868 			break;
2869 		}
2870 
2871 		/* turn off the previous option, then set the new option. */
2872 		ip6_clearpktopts(opt, optname);
2873 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2874 		if (*newdest == NULL)
2875 			return (ENOBUFS);
2876 		bcopy(dest, *newdest, destlen);
2877 
2878 		break;
2879 	}
2880 
2881 	case IPV6_2292RTHDR:
2882 	case IPV6_RTHDR:
2883 	{
2884 		struct ip6_rthdr *rth;
2885 		int rthlen;
2886 
2887 		if (len == 0) {
2888 			ip6_clearpktopts(opt, IPV6_RTHDR);
2889 			break;	/* just remove the option */
2890 		}
2891 
2892 		/* message length validation */
2893 		if (len < sizeof(struct ip6_rthdr))
2894 			return (EINVAL);
2895 		rth = (struct ip6_rthdr *)buf;
2896 		rthlen = (rth->ip6r_len + 1) << 3;
2897 		if (len != rthlen)
2898 			return (EINVAL);
2899 
2900 		switch (rth->ip6r_type) {
2901 		case IPV6_RTHDR_TYPE_0:
2902 			if (rth->ip6r_len == 0)	/* must contain one addr */
2903 				return (EINVAL);
2904 			if (rth->ip6r_len % 2) /* length must be even */
2905 				return (EINVAL);
2906 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2907 				return (EINVAL);
2908 			break;
2909 		default:
2910 			return (EINVAL);	/* not supported */
2911 		}
2912 
2913 		/* turn off the previous option */
2914 		ip6_clearpktopts(opt, IPV6_RTHDR);
2915 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2916 		if (opt->ip6po_rthdr == NULL)
2917 			return (ENOBUFS);
2918 		bcopy(rth, opt->ip6po_rthdr, rthlen);
2919 
2920 		break;
2921 	}
2922 
2923 	case IPV6_USE_MIN_MTU:
2924 		if (len != sizeof(int))
2925 			return (EINVAL);
2926 		minmtupolicy = *(int *)buf;
2927 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2928 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
2929 		    minmtupolicy != IP6PO_MINMTU_ALL) {
2930 			return (EINVAL);
2931 		}
2932 		opt->ip6po_minmtu = minmtupolicy;
2933 		break;
2934 
2935 	case IPV6_DONTFRAG:
2936 		if (len != sizeof(int))
2937 			return (EINVAL);
2938 
2939 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2940 			/*
2941 			 * we ignore this option for TCP sockets.
2942 			 * (RFC3542 leaves this case unspecified.)
2943 			 */
2944 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2945 		} else
2946 			opt->ip6po_flags |= IP6PO_DONTFRAG;
2947 		break;
2948 
2949 	case IPV6_PREFER_TEMPADDR:
2950 		if (len != sizeof(int))
2951 			return (EINVAL);
2952 		preftemp = *(int *)buf;
2953 		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2954 		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2955 		    preftemp != IP6PO_TEMPADDR_PREFER) {
2956 			return (EINVAL);
2957 		}
2958 		opt->ip6po_prefer_tempaddr = preftemp;
2959 		break;
2960 
2961 	default:
2962 		return (ENOPROTOOPT);
2963 	} /* end of switch */
2964 
2965 	return (0);
2966 }
2967 
2968 /*
2969  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2970  * packet to the input queue of a specified interface.  Note that this
2971  * calls the output routine of the loopback "driver", but with an interface
2972  * pointer that might NOT be &loif -- easier than replicating that code here.
2973  */
2974 void
2975 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
2976 {
2977 	struct mbuf *copym;
2978 	struct ip6_hdr *ip6;
2979 
2980 	copym = m_copy(m, 0, M_COPYALL);
2981 	if (copym == NULL)
2982 		return;
2983 
2984 	/*
2985 	 * Make sure to deep-copy IPv6 header portion in case the data
2986 	 * is in an mbuf cluster, so that we can safely override the IPv6
2987 	 * header portion later.
2988 	 */
2989 	if (!M_WRITABLE(copym) ||
2990 	    copym->m_len < sizeof(struct ip6_hdr)) {
2991 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
2992 		if (copym == NULL)
2993 			return;
2994 	}
2995 	ip6 = mtod(copym, struct ip6_hdr *);
2996 	/*
2997 	 * clear embedded scope identifiers if necessary.
2998 	 * in6_clearscope will touch the addresses only when necessary.
2999 	 */
3000 	in6_clearscope(&ip6->ip6_src);
3001 	in6_clearscope(&ip6->ip6_dst);
3002 	if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3003 		copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3004 		    CSUM_PSEUDO_HDR;
3005 		copym->m_pkthdr.csum_data = 0xffff;
3006 	}
3007 	if_simloop(ifp, copym, AF_INET6, 0);
3008 }
3009 
3010 /*
3011  * Chop IPv6 header off from the payload.
3012  */
3013 static int
3014 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3015 {
3016 	struct mbuf *mh;
3017 	struct ip6_hdr *ip6;
3018 
3019 	ip6 = mtod(m, struct ip6_hdr *);
3020 	if (m->m_len > sizeof(*ip6)) {
3021 		mh = m_gethdr(M_NOWAIT, MT_DATA);
3022 		if (mh == NULL) {
3023 			m_freem(m);
3024 			return ENOBUFS;
3025 		}
3026 		m_move_pkthdr(mh, m);
3027 		M_ALIGN(mh, sizeof(*ip6));
3028 		m->m_len -= sizeof(*ip6);
3029 		m->m_data += sizeof(*ip6);
3030 		mh->m_next = m;
3031 		m = mh;
3032 		m->m_len = sizeof(*ip6);
3033 		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3034 	}
3035 	exthdrs->ip6e_ip6 = m;
3036 	return 0;
3037 }
3038 
3039 /*
3040  * Compute IPv6 extension header length.
3041  */
3042 int
3043 ip6_optlen(struct inpcb *in6p)
3044 {
3045 	int len;
3046 
3047 	if (!in6p->in6p_outputopts)
3048 		return 0;
3049 
3050 	len = 0;
3051 #define elen(x) \
3052     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3053 
3054 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
3055 	if (in6p->in6p_outputopts->ip6po_rthdr)
3056 		/* dest1 is valid with rthdr only */
3057 		len += elen(in6p->in6p_outputopts->ip6po_dest1);
3058 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3059 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
3060 	return len;
3061 #undef elen
3062 }
3063