xref: /freebsd/sys/netinet6/ip6_output.c (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
32  */
33 
34 /*-
35  * Copyright (c) 1982, 1986, 1988, 1990, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  *
62  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
63  */
64 
65 #include <sys/cdefs.h>
66 __FBSDID("$FreeBSD$");
67 
68 #include "opt_inet.h"
69 #include "opt_inet6.h"
70 #include "opt_ipsec.h"
71 #include "opt_kern_tls.h"
72 #include "opt_ratelimit.h"
73 #include "opt_route.h"
74 #include "opt_rss.h"
75 #include "opt_sctp.h"
76 
77 #include <sys/param.h>
78 #include <sys/kernel.h>
79 #include <sys/ktls.h>
80 #include <sys/malloc.h>
81 #include <sys/mbuf.h>
82 #include <sys/errno.h>
83 #include <sys/priv.h>
84 #include <sys/proc.h>
85 #include <sys/protosw.h>
86 #include <sys/socket.h>
87 #include <sys/socketvar.h>
88 #include <sys/syslog.h>
89 #include <sys/ucred.h>
90 
91 #include <machine/in_cksum.h>
92 
93 #include <net/if.h>
94 #include <net/if_var.h>
95 #include <net/if_vlan_var.h>
96 #include <net/if_llatbl.h>
97 #include <net/ethernet.h>
98 #include <net/netisr.h>
99 #include <net/route.h>
100 #include <net/route/nhop.h>
101 #include <net/pfil.h>
102 #include <net/rss_config.h>
103 #include <net/vnet.h>
104 
105 #include <netinet/in.h>
106 #include <netinet/in_var.h>
107 #include <netinet/ip_var.h>
108 #include <netinet6/in6_fib.h>
109 #include <netinet6/in6_var.h>
110 #include <netinet/ip6.h>
111 #include <netinet/icmp6.h>
112 #include <netinet6/ip6_var.h>
113 #include <netinet/in_pcb.h>
114 #include <netinet/tcp_var.h>
115 #include <netinet6/nd6.h>
116 #include <netinet6/in6_rss.h>
117 
118 #include <netipsec/ipsec_support.h>
119 #if defined(SCTP) || defined(SCTP_SUPPORT)
120 #include <netinet/sctp.h>
121 #include <netinet/sctp_crc32.h>
122 #endif
123 
124 #include <netinet6/ip6protosw.h>
125 #include <netinet6/scope6_var.h>
126 
127 extern int in6_mcast_loop;
128 
129 struct ip6_exthdrs {
130 	struct mbuf *ip6e_ip6;
131 	struct mbuf *ip6e_hbh;
132 	struct mbuf *ip6e_dest1;
133 	struct mbuf *ip6e_rthdr;
134 	struct mbuf *ip6e_dest2;
135 };
136 
137 static MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
138 
139 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
140 			   struct ucred *, int);
141 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
142 	struct socket *, struct sockopt *);
143 static int ip6_getpcbopt(struct inpcb *, int, struct sockopt *);
144 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
145 	struct ucred *, int, int, int);
146 
147 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
148 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
149 	struct ip6_frag **);
150 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
151 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
152 static int ip6_getpmtu(struct route_in6 *, int,
153 	struct ifnet *, const struct in6_addr *, u_long *, int *, u_int,
154 	u_int);
155 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
156 	u_long *, int *, u_int);
157 static int ip6_getpmtu_ctl(u_int, const struct in6_addr *, u_long *);
158 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
159 
160 /*
161  * Make an extension header from option data.  hp is the source,
162  * mp is the destination, and _ol is the optlen.
163  */
164 #define	MAKE_EXTHDR(hp, mp, _ol)					\
165     do {								\
166 	if (hp) {							\
167 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
168 		error = ip6_copyexthdr((mp), (caddr_t)(hp),		\
169 		    ((eh)->ip6e_len + 1) << 3);				\
170 		if (error)						\
171 			goto freehdrs;					\
172 		(_ol) += (*(mp))->m_len;				\
173 	}								\
174     } while (/*CONSTCOND*/ 0)
175 
176 /*
177  * Form a chain of extension headers.
178  * m is the extension header mbuf
179  * mp is the previous mbuf in the chain
180  * p is the next header
181  * i is the type of option.
182  */
183 #define MAKE_CHAIN(m, mp, p, i)\
184     do {\
185 	if (m) {\
186 		if (!hdrsplit) \
187 			panic("%s:%d: assumption failed: "\
188 			    "hdr not split: hdrsplit %d exthdrs %p",\
189 			    __func__, __LINE__, hdrsplit, &exthdrs);\
190 		*mtod((m), u_char *) = *(p);\
191 		*(p) = (i);\
192 		p = mtod((m), u_char *);\
193 		(m)->m_next = (mp)->m_next;\
194 		(mp)->m_next = (m);\
195 		(mp) = (m);\
196 	}\
197     } while (/*CONSTCOND*/ 0)
198 
199 void
200 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
201 {
202 	u_short csum;
203 
204 	csum = in_cksum_skip(m, offset + plen, offset);
205 	if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
206 		csum = 0xffff;
207 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
208 
209 	if (offset + sizeof(csum) > m->m_len)
210 		m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
211 	else
212 		*(u_short *)mtodo(m, offset) = csum;
213 }
214 
215 static void
216 ip6_output_delayed_csum(struct mbuf *m, struct ifnet *ifp, int csum_flags,
217     int plen, int optlen)
218 {
219 
220 	KASSERT((plen >= optlen), ("%s:%d: plen %d < optlen %d, m %p, ifp %p "
221 	    "csum_flags %#x",
222 	    __func__, __LINE__, plen, optlen, m, ifp, csum_flags));
223 
224 	if (csum_flags & CSUM_DELAY_DATA_IPV6) {
225 		in6_delayed_cksum(m, plen - optlen,
226 		    sizeof(struct ip6_hdr) + optlen);
227 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
228 	}
229 #if defined(SCTP) || defined(SCTP_SUPPORT)
230 	if (csum_flags & CSUM_SCTP_IPV6) {
231 		sctp_delayed_cksum(m, sizeof(struct ip6_hdr) + optlen);
232 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
233 	}
234 #endif
235 }
236 
237 int
238 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
239     int fraglen , uint32_t id)
240 {
241 	struct mbuf *m, **mnext, *m_frgpart;
242 	struct ip6_hdr *ip6, *mhip6;
243 	struct ip6_frag *ip6f;
244 	int off;
245 	int error;
246 	int tlen = m0->m_pkthdr.len;
247 
248 	KASSERT((fraglen % 8 == 0), ("Fragment length must be a multiple of 8"));
249 
250 	m = m0;
251 	ip6 = mtod(m, struct ip6_hdr *);
252 	mnext = &m->m_nextpkt;
253 
254 	for (off = hlen; off < tlen; off += fraglen) {
255 		m = m_gethdr(M_NOWAIT, MT_DATA);
256 		if (!m) {
257 			IP6STAT_INC(ip6s_odropped);
258 			return (ENOBUFS);
259 		}
260 
261 		/*
262 		 * Make sure the complete packet header gets copied
263 		 * from the originating mbuf to the newly created
264 		 * mbuf. This also ensures that existing firewall
265 		 * classification(s), VLAN tags and so on get copied
266 		 * to the resulting fragmented packet(s):
267 		 */
268 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
269 			m_free(m);
270 			IP6STAT_INC(ip6s_odropped);
271 			return (ENOBUFS);
272 		}
273 
274 		*mnext = m;
275 		mnext = &m->m_nextpkt;
276 		m->m_data += max_linkhdr;
277 		mhip6 = mtod(m, struct ip6_hdr *);
278 		*mhip6 = *ip6;
279 		m->m_len = sizeof(*mhip6);
280 		error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
281 		if (error) {
282 			IP6STAT_INC(ip6s_odropped);
283 			return (error);
284 		}
285 		ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
286 		if (off + fraglen >= tlen)
287 			fraglen = tlen - off;
288 		else
289 			ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
290 		mhip6->ip6_plen = htons((u_short)(fraglen + hlen +
291 		    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
292 		if ((m_frgpart = m_copym(m0, off, fraglen, M_NOWAIT)) == NULL) {
293 			IP6STAT_INC(ip6s_odropped);
294 			return (ENOBUFS);
295 		}
296 		m_cat(m, m_frgpart);
297 		m->m_pkthdr.len = fraglen + hlen + sizeof(*ip6f);
298 		ip6f->ip6f_reserved = 0;
299 		ip6f->ip6f_ident = id;
300 		ip6f->ip6f_nxt = nextproto;
301 		IP6STAT_INC(ip6s_ofragments);
302 		in6_ifstat_inc(ifp, ifs6_out_fragcreat);
303 	}
304 
305 	return (0);
306 }
307 
308 static int
309 ip6_output_send(struct inpcb *inp, struct ifnet *ifp, struct ifnet *origifp,
310     struct mbuf *m, struct sockaddr_in6 *dst, struct route_in6 *ro,
311     bool stamp_tag)
312 {
313 #ifdef KERN_TLS
314 	struct ktls_session *tls = NULL;
315 #endif
316 	struct m_snd_tag *mst;
317 	int error;
318 
319 	MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
320 	mst = NULL;
321 
322 #ifdef KERN_TLS
323 	/*
324 	 * If this is an unencrypted TLS record, save a reference to
325 	 * the record.  This local reference is used to call
326 	 * ktls_output_eagain after the mbuf has been freed (thus
327 	 * dropping the mbuf's reference) in if_output.
328 	 */
329 	if (m->m_next != NULL && mbuf_has_tls_session(m->m_next)) {
330 		tls = ktls_hold(m->m_next->m_epg_tls);
331 		mst = tls->snd_tag;
332 
333 		/*
334 		 * If a TLS session doesn't have a valid tag, it must
335 		 * have had an earlier ifp mismatch, so drop this
336 		 * packet.
337 		 */
338 		if (mst == NULL) {
339 			m_freem(m);
340 			error = EAGAIN;
341 			goto done;
342 		}
343 		/*
344 		 * Always stamp tags that include NIC ktls.
345 		 */
346 		stamp_tag = true;
347 	}
348 #endif
349 #ifdef RATELIMIT
350 	if (inp != NULL && mst == NULL) {
351 		if ((inp->inp_flags2 & INP_RATE_LIMIT_CHANGED) != 0 ||
352 		    (inp->inp_snd_tag != NULL &&
353 		    inp->inp_snd_tag->ifp != ifp))
354 			in_pcboutput_txrtlmt(inp, ifp, m);
355 
356 		if (inp->inp_snd_tag != NULL)
357 			mst = inp->inp_snd_tag;
358 	}
359 #endif
360 	if (stamp_tag && mst != NULL) {
361 		KASSERT(m->m_pkthdr.rcvif == NULL,
362 		    ("trying to add a send tag to a forwarded packet"));
363 		if (mst->ifp != ifp) {
364 			m_freem(m);
365 			error = EAGAIN;
366 			goto done;
367 		}
368 
369 		/* stamp send tag on mbuf */
370 		m->m_pkthdr.snd_tag = m_snd_tag_ref(mst);
371 		m->m_pkthdr.csum_flags |= CSUM_SND_TAG;
372 	}
373 
374 	error = nd6_output_ifp(ifp, origifp, m, dst, (struct route *)ro);
375 
376 done:
377 	/* Check for route change invalidating send tags. */
378 #ifdef KERN_TLS
379 	if (tls != NULL) {
380 		if (error == EAGAIN)
381 			error = ktls_output_eagain(inp, tls);
382 		ktls_free(tls);
383 	}
384 #endif
385 #ifdef RATELIMIT
386 	if (error == EAGAIN)
387 		in_pcboutput_eagain(inp);
388 #endif
389 	return (error);
390 }
391 
392 /*
393  * IP6 output.
394  * The packet in mbuf chain m contains a skeletal IP6 header (with pri, len,
395  * nxt, hlim, src, dst).
396  * This function may modify ver and hlim only.
397  * The mbuf chain containing the packet will be freed.
398  * The mbuf opt, if present, will not be freed.
399  * If route_in6 ro is present and has ro_nh initialized, route lookup would be
400  * skipped and ro->ro_nh would be used. If ro is present but ro->ro_nh is NULL,
401  * then result of route lookup is stored in ro->ro_nh.
402  *
403  * Type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and nd_ifinfo.linkmtu
404  * is uint32_t.  So we use u_long to hold largest one, which is rt_mtu.
405  *
406  * ifpp - XXX: just for statistics
407  */
408 int
409 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
410     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
411     struct ifnet **ifpp, struct inpcb *inp)
412 {
413 	struct ip6_hdr *ip6;
414 	struct ifnet *ifp, *origifp;
415 	struct mbuf *m = m0;
416 	struct mbuf *mprev;
417 	struct route_in6 *ro_pmtu;
418 	struct nhop_object *nh;
419 	struct sockaddr_in6 *dst, sin6, src_sa, dst_sa;
420 	struct in6_addr odst;
421 	u_char *nexthdrp;
422 	int tlen, len;
423 	int error = 0;
424 	int vlan_pcp = -1;
425 	struct in6_ifaddr *ia = NULL;
426 	u_long mtu;
427 	int alwaysfrag, dontfrag;
428 	u_int32_t optlen, plen = 0, unfragpartlen;
429 	struct ip6_exthdrs exthdrs;
430 	struct in6_addr src0, dst0;
431 	u_int32_t zone;
432 	bool hdrsplit;
433 	int sw_csum, tso;
434 	int needfiblookup;
435 	uint32_t fibnum;
436 	struct m_tag *fwd_tag = NULL;
437 	uint32_t id;
438 
439 	NET_EPOCH_ASSERT();
440 
441 	if (inp != NULL) {
442 		INP_LOCK_ASSERT(inp);
443 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
444 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
445 			/* Unconditionally set flowid. */
446 			m->m_pkthdr.flowid = inp->inp_flowid;
447 			M_HASHTYPE_SET(m, inp->inp_flowtype);
448 		}
449 		if ((inp->inp_flags2 & INP_2PCP_SET) != 0)
450 			vlan_pcp = (inp->inp_flags2 & INP_2PCP_MASK) >>
451 			    INP_2PCP_SHIFT;
452 #ifdef NUMA
453 		m->m_pkthdr.numa_domain = inp->inp_numa_domain;
454 #endif
455 	}
456 
457 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
458 	/*
459 	 * IPSec checking which handles several cases.
460 	 * FAST IPSEC: We re-injected the packet.
461 	 * XXX: need scope argument.
462 	 */
463 	if (IPSEC_ENABLED(ipv6)) {
464 		if ((error = IPSEC_OUTPUT(ipv6, m, inp)) != 0) {
465 			if (error == EINPROGRESS)
466 				error = 0;
467 			goto done;
468 		}
469 	}
470 #endif /* IPSEC */
471 
472 	/* Source address validation. */
473 	ip6 = mtod(m, struct ip6_hdr *);
474 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
475 	    (flags & IPV6_UNSPECSRC) == 0) {
476 		error = EOPNOTSUPP;
477 		IP6STAT_INC(ip6s_badscope);
478 		goto bad;
479 	}
480 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
481 		error = EOPNOTSUPP;
482 		IP6STAT_INC(ip6s_badscope);
483 		goto bad;
484 	}
485 
486 	/*
487 	 * If we are given packet options to add extension headers prepare them.
488 	 * Calculate the total length of the extension header chain.
489 	 * Keep the length of the unfragmentable part for fragmentation.
490 	 */
491 	bzero(&exthdrs, sizeof(exthdrs));
492 	optlen = 0;
493 	unfragpartlen = sizeof(struct ip6_hdr);
494 	if (opt) {
495 		/* Hop-by-Hop options header. */
496 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh, optlen);
497 
498 		/* Destination options header (1st part). */
499 		if (opt->ip6po_rthdr) {
500 #ifndef RTHDR_SUPPORT_IMPLEMENTED
501 			/*
502 			 * If there is a routing header, discard the packet
503 			 * right away here. RH0/1 are obsolete and we do not
504 			 * currently support RH2/3/4.
505 			 * People trying to use RH253/254 may want to disable
506 			 * this check.
507 			 * The moment we do support any routing header (again)
508 			 * this block should check the routing type more
509 			 * selectively.
510 			 */
511 			error = EINVAL;
512 			goto bad;
513 #endif
514 
515 			/*
516 			 * Destination options header (1st part).
517 			 * This only makes sense with a routing header.
518 			 * See Section 9.2 of RFC 3542.
519 			 * Disabling this part just for MIP6 convenience is
520 			 * a bad idea.  We need to think carefully about a
521 			 * way to make the advanced API coexist with MIP6
522 			 * options, which might automatically be inserted in
523 			 * the kernel.
524 			 */
525 			MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1,
526 			    optlen);
527 		}
528 		/* Routing header. */
529 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr, optlen);
530 
531 		unfragpartlen += optlen;
532 
533 		/*
534 		 * NOTE: we don't add AH/ESP length here (done in
535 		 * ip6_ipsec_output()).
536 		 */
537 
538 		/* Destination options header (2nd part). */
539 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2, optlen);
540 	}
541 
542 	/*
543 	 * If there is at least one extension header,
544 	 * separate IP6 header from the payload.
545 	 */
546 	hdrsplit = false;
547 	if (optlen) {
548 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
549 			m = NULL;
550 			goto freehdrs;
551 		}
552 		m = exthdrs.ip6e_ip6;
553 		ip6 = mtod(m, struct ip6_hdr *);
554 		hdrsplit = true;
555 	}
556 
557 	/* Adjust mbuf packet header length. */
558 	m->m_pkthdr.len += optlen;
559 	plen = m->m_pkthdr.len - sizeof(*ip6);
560 
561 	/* If this is a jumbo payload, insert a jumbo payload option. */
562 	if (plen > IPV6_MAXPACKET) {
563 		if (!hdrsplit) {
564 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
565 				m = NULL;
566 				goto freehdrs;
567 			}
568 			m = exthdrs.ip6e_ip6;
569 			ip6 = mtod(m, struct ip6_hdr *);
570 			hdrsplit = true;
571 		}
572 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
573 			goto freehdrs;
574 		ip6->ip6_plen = 0;
575 	} else
576 		ip6->ip6_plen = htons(plen);
577 	nexthdrp = &ip6->ip6_nxt;
578 
579 	if (optlen) {
580 		/*
581 		 * Concatenate headers and fill in next header fields.
582 		 * Here we have, on "m"
583 		 *	IPv6 payload
584 		 * and we insert headers accordingly.
585 		 * Finally, we should be getting:
586 		 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload].
587 		 *
588 		 * During the header composing process "m" points to IPv6
589 		 * header.  "mprev" points to an extension header prior to esp.
590 		 */
591 		mprev = m;
592 
593 		/*
594 		 * We treat dest2 specially.  This makes IPsec processing
595 		 * much easier.  The goal here is to make mprev point the
596 		 * mbuf prior to dest2.
597 		 *
598 		 * Result: IPv6 dest2 payload.
599 		 * m and mprev will point to IPv6 header.
600 		 */
601 		if (exthdrs.ip6e_dest2) {
602 			if (!hdrsplit)
603 				panic("%s:%d: assumption failed: "
604 				    "hdr not split: hdrsplit %d exthdrs %p",
605 				    __func__, __LINE__, hdrsplit, &exthdrs);
606 			exthdrs.ip6e_dest2->m_next = m->m_next;
607 			m->m_next = exthdrs.ip6e_dest2;
608 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
609 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
610 		}
611 
612 		/*
613 		 * Result: IPv6 hbh dest1 rthdr dest2 payload.
614 		 * m will point to IPv6 header.  mprev will point to the
615 		 * extension header prior to dest2 (rthdr in the above case).
616 		 */
617 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
618 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
619 			   IPPROTO_DSTOPTS);
620 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
621 			   IPPROTO_ROUTING);
622 	}
623 
624 	IP6STAT_INC(ip6s_localout);
625 
626 	/* Route packet. */
627 	ro_pmtu = ro;
628 	if (opt && opt->ip6po_rthdr)
629 		ro = &opt->ip6po_route;
630 	if (ro != NULL)
631 		dst = (struct sockaddr_in6 *)&ro->ro_dst;
632 	else
633 		dst = &sin6;
634 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
635 
636 again:
637 	/*
638 	 * If specified, try to fill in the traffic class field.
639 	 * Do not override if a non-zero value is already set.
640 	 * We check the diffserv field and the ECN field separately.
641 	 */
642 	if (opt && opt->ip6po_tclass >= 0) {
643 		int mask = 0;
644 
645 		if (IPV6_DSCP(ip6) == 0)
646 			mask |= 0xfc;
647 		if (IPV6_ECN(ip6) == 0)
648 			mask |= 0x03;
649 		if (mask != 0)
650 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
651 	}
652 
653 	/* Fill in or override the hop limit field, if necessary. */
654 	if (opt && opt->ip6po_hlim != -1)
655 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
656 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
657 		if (im6o != NULL)
658 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
659 		else
660 			ip6->ip6_hlim = V_ip6_defmcasthlim;
661 	}
662 
663 	if (ro == NULL || ro->ro_nh == NULL) {
664 		bzero(dst, sizeof(*dst));
665 		dst->sin6_family = AF_INET6;
666 		dst->sin6_len = sizeof(*dst);
667 		dst->sin6_addr = ip6->ip6_dst;
668 	}
669 	/*
670 	 * Validate route against routing table changes.
671 	 * Make sure that the address family is set in route.
672 	 */
673 	nh = NULL;
674 	ifp = NULL;
675 	mtu = 0;
676 	if (ro != NULL) {
677 		if (ro->ro_nh != NULL && inp != NULL) {
678 			ro->ro_dst.sin6_family = AF_INET6; /* XXX KASSERT? */
679 			NH_VALIDATE((struct route *)ro, &inp->inp_rt_cookie,
680 			    fibnum);
681 		}
682 		if (ro->ro_nh != NULL && fwd_tag == NULL &&
683 		    (!NH_IS_VALID(ro->ro_nh) ||
684 		    ro->ro_dst.sin6_family != AF_INET6 ||
685 		    !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)))
686 			RO_INVALIDATE_CACHE(ro);
687 
688 		if (ro->ro_nh != NULL && fwd_tag == NULL &&
689 		    ro->ro_dst.sin6_family == AF_INET6 &&
690 		    IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)) {
691 			nh = ro->ro_nh;
692 			ifp = nh->nh_ifp;
693 		} else {
694 			if (ro->ro_lle)
695 				LLE_FREE(ro->ro_lle);	/* zeros ro_lle */
696 			ro->ro_lle = NULL;
697 			if (fwd_tag == NULL) {
698 				bzero(&dst_sa, sizeof(dst_sa));
699 				dst_sa.sin6_family = AF_INET6;
700 				dst_sa.sin6_len = sizeof(dst_sa);
701 				dst_sa.sin6_addr = ip6->ip6_dst;
702 			}
703 			error = in6_selectroute(&dst_sa, opt, im6o, ro, &ifp,
704 			    &nh, fibnum, m->m_pkthdr.flowid);
705 			if (error != 0) {
706 				IP6STAT_INC(ip6s_noroute);
707 				if (ifp != NULL)
708 					in6_ifstat_inc(ifp, ifs6_out_discard);
709 				goto bad;
710 			}
711 			if (ifp != NULL)
712 			    mtu = ifp->if_mtu;
713 		}
714 		if (nh == NULL) {
715 			/*
716 			 * If in6_selectroute() does not return a nexthop
717 			 * dst may not have been updated.
718 			 */
719 			*dst = dst_sa;	/* XXX */
720 		} else {
721 			if (nh->nh_flags & NHF_HOST)
722 			    mtu = nh->nh_mtu;
723 			ia = (struct in6_ifaddr *)(nh->nh_ifa);
724 			counter_u64_add(nh->nh_pksent, 1);
725 		}
726 	} else {
727 		struct nhop_object *nh;
728 		struct in6_addr kdst;
729 		uint32_t scopeid;
730 
731 		if (fwd_tag == NULL) {
732 			bzero(&dst_sa, sizeof(dst_sa));
733 			dst_sa.sin6_family = AF_INET6;
734 			dst_sa.sin6_len = sizeof(dst_sa);
735 			dst_sa.sin6_addr = ip6->ip6_dst;
736 		}
737 
738 		if (IN6_IS_ADDR_MULTICAST(&dst_sa.sin6_addr) &&
739 		    im6o != NULL &&
740 		    (ifp = im6o->im6o_multicast_ifp) != NULL) {
741 			/* We do not need a route lookup. */
742 			*dst = dst_sa;	/* XXX */
743 			goto nonh6lookup;
744 		}
745 
746 		in6_splitscope(&dst_sa.sin6_addr, &kdst, &scopeid);
747 
748 		if (IN6_IS_ADDR_MC_LINKLOCAL(&dst_sa.sin6_addr) ||
749 		    IN6_IS_ADDR_MC_NODELOCAL(&dst_sa.sin6_addr)) {
750 			if (scopeid > 0) {
751 				ifp = in6_getlinkifnet(scopeid);
752 				if (ifp == NULL) {
753 					error = EHOSTUNREACH;
754 					goto bad;
755 				}
756 				*dst = dst_sa;	/* XXX */
757 				goto nonh6lookup;
758 			}
759 		}
760 
761 		nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE,
762 		    m->m_pkthdr.flowid);
763 		if (nh == NULL) {
764 			IP6STAT_INC(ip6s_noroute);
765 			/* No ifp in6_ifstat_inc(ifp, ifs6_out_discard); */
766 			error = EHOSTUNREACH;;
767 			goto bad;
768 		}
769 
770 		ifp = nh->nh_ifp;
771 		mtu = nh->nh_mtu;
772 		ia = ifatoia6(nh->nh_ifa);
773 		if (nh->nh_flags & NHF_GATEWAY)
774 			dst->sin6_addr = nh->gw6_sa.sin6_addr;
775 nonh6lookup:
776 		;
777 	}
778 
779 	/* Then nh (for unicast) and ifp must be non-NULL valid values. */
780 	if ((flags & IPV6_FORWARDING) == 0) {
781 		/* XXX: the FORWARDING flag can be set for mrouting. */
782 		in6_ifstat_inc(ifp, ifs6_out_request);
783 	}
784 
785 	/* Setup data structures for scope ID checks. */
786 	src0 = ip6->ip6_src;
787 	bzero(&src_sa, sizeof(src_sa));
788 	src_sa.sin6_family = AF_INET6;
789 	src_sa.sin6_len = sizeof(src_sa);
790 	src_sa.sin6_addr = ip6->ip6_src;
791 
792 	dst0 = ip6->ip6_dst;
793 	/* Re-initialize to be sure. */
794 	bzero(&dst_sa, sizeof(dst_sa));
795 	dst_sa.sin6_family = AF_INET6;
796 	dst_sa.sin6_len = sizeof(dst_sa);
797 	dst_sa.sin6_addr = ip6->ip6_dst;
798 
799 	/* Check for valid scope ID. */
800 	if (in6_setscope(&src0, ifp, &zone) == 0 &&
801 	    sa6_recoverscope(&src_sa) == 0 && zone == src_sa.sin6_scope_id &&
802 	    in6_setscope(&dst0, ifp, &zone) == 0 &&
803 	    sa6_recoverscope(&dst_sa) == 0 && zone == dst_sa.sin6_scope_id) {
804 		/*
805 		 * The outgoing interface is in the zone of the source
806 		 * and destination addresses.
807 		 *
808 		 * Because the loopback interface cannot receive
809 		 * packets with a different scope ID than its own,
810 		 * there is a trick to pretend the outgoing packet
811 		 * was received by the real network interface, by
812 		 * setting "origifp" different from "ifp". This is
813 		 * only allowed when "ifp" is a loopback network
814 		 * interface. Refer to code in nd6_output_ifp() for
815 		 * more details.
816 		 */
817 		origifp = ifp;
818 
819 		/*
820 		 * We should use ia_ifp to support the case of sending
821 		 * packets to an address of our own.
822 		 */
823 		if (ia != NULL && ia->ia_ifp)
824 			ifp = ia->ia_ifp;
825 
826 	} else if ((ifp->if_flags & IFF_LOOPBACK) == 0 ||
827 	    sa6_recoverscope(&src_sa) != 0 ||
828 	    sa6_recoverscope(&dst_sa) != 0 ||
829 	    dst_sa.sin6_scope_id == 0 ||
830 	    (src_sa.sin6_scope_id != 0 &&
831 	    src_sa.sin6_scope_id != dst_sa.sin6_scope_id) ||
832 	    (origifp = ifnet_byindex(dst_sa.sin6_scope_id)) == NULL) {
833 		/*
834 		 * If the destination network interface is not a
835 		 * loopback interface, or the destination network
836 		 * address has no scope ID, or the source address has
837 		 * a scope ID set which is different from the
838 		 * destination address one, or there is no network
839 		 * interface representing this scope ID, the address
840 		 * pair is considered invalid.
841 		 */
842 		IP6STAT_INC(ip6s_badscope);
843 		in6_ifstat_inc(ifp, ifs6_out_discard);
844 		if (error == 0)
845 			error = EHOSTUNREACH; /* XXX */
846 		goto bad;
847 	}
848 	/* All scope ID checks are successful. */
849 
850 	if (nh && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
851 		if (opt && opt->ip6po_nextroute.ro_nh) {
852 			/*
853 			 * The nexthop is explicitly specified by the
854 			 * application.  We assume the next hop is an IPv6
855 			 * address.
856 			 */
857 			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
858 		}
859 		else if ((nh->nh_flags & NHF_GATEWAY))
860 			dst = &nh->gw6_sa;
861 	}
862 
863 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
864 		m->m_flags &= ~(M_BCAST | M_MCAST); /* Just in case. */
865 	} else {
866 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
867 		in6_ifstat_inc(ifp, ifs6_out_mcast);
868 
869 		/* Confirm that the outgoing interface supports multicast. */
870 		if (!(ifp->if_flags & IFF_MULTICAST)) {
871 			IP6STAT_INC(ip6s_noroute);
872 			in6_ifstat_inc(ifp, ifs6_out_discard);
873 			error = ENETUNREACH;
874 			goto bad;
875 		}
876 		if ((im6o == NULL && in6_mcast_loop) ||
877 		    (im6o && im6o->im6o_multicast_loop)) {
878 			/*
879 			 * Loop back multicast datagram if not expressly
880 			 * forbidden to do so, even if we have not joined
881 			 * the address; protocols will filter it later,
882 			 * thus deferring a hash lookup and lock acquisition
883 			 * at the expense of an m_copym().
884 			 */
885 			ip6_mloopback(ifp, m);
886 		} else {
887 			/*
888 			 * If we are acting as a multicast router, perform
889 			 * multicast forwarding as if the packet had just
890 			 * arrived on the interface to which we are about
891 			 * to send.  The multicast forwarding function
892 			 * recursively calls this function, using the
893 			 * IPV6_FORWARDING flag to prevent infinite recursion.
894 			 *
895 			 * Multicasts that are looped back by ip6_mloopback(),
896 			 * above, will be forwarded by the ip6_input() routine,
897 			 * if necessary.
898 			 */
899 			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
900 				/*
901 				 * XXX: ip6_mforward expects that rcvif is NULL
902 				 * when it is called from the originating path.
903 				 * However, it may not always be the case.
904 				 */
905 				m->m_pkthdr.rcvif = NULL;
906 				if (ip6_mforward(ip6, ifp, m) != 0) {
907 					m_freem(m);
908 					goto done;
909 				}
910 			}
911 		}
912 		/*
913 		 * Multicasts with a hoplimit of zero may be looped back,
914 		 * above, but must not be transmitted on a network.
915 		 * Also, multicasts addressed to the loopback interface
916 		 * are not sent -- the above call to ip6_mloopback() will
917 		 * loop back a copy if this host actually belongs to the
918 		 * destination group on the loopback interface.
919 		 */
920 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
921 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
922 			m_freem(m);
923 			goto done;
924 		}
925 	}
926 
927 	/*
928 	 * Fill the outgoing inteface to tell the upper layer
929 	 * to increment per-interface statistics.
930 	 */
931 	if (ifpp)
932 		*ifpp = ifp;
933 
934 	/* Determine path MTU. */
935 	if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &ip6->ip6_dst,
936 		    &mtu, &alwaysfrag, fibnum, *nexthdrp)) != 0)
937 		goto bad;
938 	KASSERT(mtu > 0, ("%s:%d: mtu %ld, ro_pmtu %p ro %p ifp %p "
939 	    "alwaysfrag %d fibnum %u\n", __func__, __LINE__, mtu, ro_pmtu, ro,
940 	    ifp, alwaysfrag, fibnum));
941 
942 	/*
943 	 * The caller of this function may specify to use the minimum MTU
944 	 * in some cases.
945 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
946 	 * setting.  The logic is a bit complicated; by default, unicast
947 	 * packets will follow path MTU while multicast packets will be sent at
948 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
949 	 * including unicast ones will be sent at the minimum MTU.  Multicast
950 	 * packets will always be sent at the minimum MTU unless
951 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
952 	 * See RFC 3542 for more details.
953 	 */
954 	if (mtu > IPV6_MMTU) {
955 		if ((flags & IPV6_MINMTU))
956 			mtu = IPV6_MMTU;
957 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
958 			mtu = IPV6_MMTU;
959 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
960 			 (opt == NULL ||
961 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
962 			mtu = IPV6_MMTU;
963 		}
964 	}
965 
966 	/*
967 	 * Clear embedded scope identifiers if necessary.
968 	 * in6_clearscope() will touch the addresses only when necessary.
969 	 */
970 	in6_clearscope(&ip6->ip6_src);
971 	in6_clearscope(&ip6->ip6_dst);
972 
973 	/*
974 	 * If the outgoing packet contains a hop-by-hop options header,
975 	 * it must be examined and processed even by the source node.
976 	 * (RFC 2460, section 4.)
977 	 */
978 	if (exthdrs.ip6e_hbh) {
979 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
980 		u_int32_t dummy; /* XXX unused */
981 		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
982 
983 #ifdef DIAGNOSTIC
984 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
985 			panic("ip6e_hbh is not contiguous");
986 #endif
987 		/*
988 		 *  XXX: if we have to send an ICMPv6 error to the sender,
989 		 *       we need the M_LOOP flag since icmp6_error() expects
990 		 *       the IPv6 and the hop-by-hop options header are
991 		 *       contiguous unless the flag is set.
992 		 */
993 		m->m_flags |= M_LOOP;
994 		m->m_pkthdr.rcvif = ifp;
995 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
996 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
997 		    &dummy, &plen) < 0) {
998 			/* m was already freed at this point. */
999 			error = EINVAL;/* better error? */
1000 			goto done;
1001 		}
1002 		m->m_flags &= ~M_LOOP; /* XXX */
1003 		m->m_pkthdr.rcvif = NULL;
1004 	}
1005 
1006 	/* Jump over all PFIL processing if hooks are not active. */
1007 	if (!PFIL_HOOKED_OUT(V_inet6_pfil_head))
1008 		goto passout;
1009 
1010 	odst = ip6->ip6_dst;
1011 	/* Run through list of hooks for output packets. */
1012 	switch (pfil_run_hooks(V_inet6_pfil_head, &m, ifp, PFIL_OUT, inp)) {
1013 	case PFIL_PASS:
1014 		ip6 = mtod(m, struct ip6_hdr *);
1015 		break;
1016 	case PFIL_DROPPED:
1017 		error = EACCES;
1018 		/* FALLTHROUGH */
1019 	case PFIL_CONSUMED:
1020 		goto done;
1021 	}
1022 
1023 	needfiblookup = 0;
1024 	/* See if destination IP address was changed by packet filter. */
1025 	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
1026 		m->m_flags |= M_SKIP_FIREWALL;
1027 		/* If destination is now ourself drop to ip6_input(). */
1028 		if (in6_localip(&ip6->ip6_dst)) {
1029 			m->m_flags |= M_FASTFWD_OURS;
1030 			if (m->m_pkthdr.rcvif == NULL)
1031 				m->m_pkthdr.rcvif = V_loif;
1032 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1033 				m->m_pkthdr.csum_flags |=
1034 				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
1035 				m->m_pkthdr.csum_data = 0xffff;
1036 			}
1037 #if defined(SCTP) || defined(SCTP_SUPPORT)
1038 			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
1039 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
1040 #endif
1041 			error = netisr_queue(NETISR_IPV6, m);
1042 			goto done;
1043 		} else {
1044 			if (ro != NULL)
1045 				RO_INVALIDATE_CACHE(ro);
1046 			needfiblookup = 1; /* Redo the routing table lookup. */
1047 		}
1048 	}
1049 	/* See if fib was changed by packet filter. */
1050 	if (fibnum != M_GETFIB(m)) {
1051 		m->m_flags |= M_SKIP_FIREWALL;
1052 		fibnum = M_GETFIB(m);
1053 		if (ro != NULL)
1054 			RO_INVALIDATE_CACHE(ro);
1055 		needfiblookup = 1;
1056 	}
1057 	if (needfiblookup)
1058 		goto again;
1059 
1060 	/* See if local, if yes, send it to netisr. */
1061 	if (m->m_flags & M_FASTFWD_OURS) {
1062 		if (m->m_pkthdr.rcvif == NULL)
1063 			m->m_pkthdr.rcvif = V_loif;
1064 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1065 			m->m_pkthdr.csum_flags |=
1066 			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
1067 			m->m_pkthdr.csum_data = 0xffff;
1068 		}
1069 #if defined(SCTP) || defined(SCTP_SUPPORT)
1070 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
1071 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
1072 #endif
1073 		error = netisr_queue(NETISR_IPV6, m);
1074 		goto done;
1075 	}
1076 	/* Or forward to some other address? */
1077 	if ((m->m_flags & M_IP6_NEXTHOP) &&
1078 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
1079 		if (ro != NULL)
1080 			dst = (struct sockaddr_in6 *)&ro->ro_dst;
1081 		else
1082 			dst = &sin6;
1083 		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
1084 		m->m_flags |= M_SKIP_FIREWALL;
1085 		m->m_flags &= ~M_IP6_NEXTHOP;
1086 		m_tag_delete(m, fwd_tag);
1087 		goto again;
1088 	}
1089 
1090 passout:
1091 	if (vlan_pcp > -1)
1092 		EVL_APPLY_PRI(m, vlan_pcp);
1093 
1094 	/* Ensure the packet data is mapped if the interface requires it. */
1095 	if ((ifp->if_capenable & IFCAP_MEXTPG) == 0) {
1096 		m = mb_unmapped_to_ext(m);
1097 		if (m == NULL) {
1098 			IP6STAT_INC(ip6s_odropped);
1099 			return (ENOBUFS);
1100 		}
1101 	}
1102 
1103 	/*
1104 	 * Send the packet to the outgoing interface.
1105 	 * If necessary, do IPv6 fragmentation before sending.
1106 	 *
1107 	 * The logic here is rather complex:
1108 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
1109 	 * 1-a:	send as is if tlen <= path mtu
1110 	 * 1-b:	fragment if tlen > path mtu
1111 	 *
1112 	 * 2: if user asks us not to fragment (dontfrag == 1)
1113 	 * 2-a:	send as is if tlen <= interface mtu
1114 	 * 2-b:	error if tlen > interface mtu
1115 	 *
1116 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
1117 	 *	always fragment
1118 	 *
1119 	 * 4: if dontfrag == 1 && alwaysfrag == 1
1120 	 *	error, as we cannot handle this conflicting request.
1121 	 */
1122 	sw_csum = m->m_pkthdr.csum_flags;
1123 	if (!hdrsplit) {
1124 		tso = ((sw_csum & ifp->if_hwassist &
1125 		    (CSUM_TSO | CSUM_INNER_TSO)) != 0) ? 1 : 0;
1126 		sw_csum &= ~ifp->if_hwassist;
1127 	} else
1128 		tso = 0;
1129 	/*
1130 	 * If we added extension headers, we will not do TSO and calculate the
1131 	 * checksums ourselves for now.
1132 	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
1133 	 * with ext. hdrs.
1134 	 */
1135 	ip6_output_delayed_csum(m, ifp, sw_csum, plen, optlen);
1136 	/* XXX-BZ m->m_pkthdr.csum_flags &= ~ifp->if_hwassist; */
1137 	tlen = m->m_pkthdr.len;
1138 
1139 	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
1140 		dontfrag = 1;
1141 	else
1142 		dontfrag = 0;
1143 	if (dontfrag && alwaysfrag) {	/* Case 4. */
1144 		/* Conflicting request - can't transmit. */
1145 		error = EMSGSIZE;
1146 		goto bad;
1147 	}
1148 	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* Case 2-b. */
1149 		/*
1150 		 * Even if the DONTFRAG option is specified, we cannot send the
1151 		 * packet when the data length is larger than the MTU of the
1152 		 * outgoing interface.
1153 		 * Notify the error by sending IPV6_PATHMTU ancillary data if
1154 		 * application wanted to know the MTU value. Also return an
1155 		 * error code (this is not described in the API spec).
1156 		 */
1157 		if (inp != NULL)
1158 			ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
1159 		error = EMSGSIZE;
1160 		goto bad;
1161 	}
1162 
1163 	/* Transmit packet without fragmentation. */
1164 	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* Cases 1-a and 2-a. */
1165 		struct in6_ifaddr *ia6;
1166 
1167 		ip6 = mtod(m, struct ip6_hdr *);
1168 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
1169 		if (ia6) {
1170 			/* Record statistics for this interface address. */
1171 			counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
1172 			counter_u64_add(ia6->ia_ifa.ifa_obytes,
1173 			    m->m_pkthdr.len);
1174 		}
1175 		error = ip6_output_send(inp, ifp, origifp, m, dst, ro,
1176 		    (flags & IP_NO_SND_TAG_RL) ? false : true);
1177 		goto done;
1178 	}
1179 
1180 	/* Try to fragment the packet.  Cases 1-b and 3. */
1181 	if (mtu < IPV6_MMTU) {
1182 		/* Path MTU cannot be less than IPV6_MMTU. */
1183 		error = EMSGSIZE;
1184 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1185 		goto bad;
1186 	} else if (ip6->ip6_plen == 0) {
1187 		/* Jumbo payload cannot be fragmented. */
1188 		error = EMSGSIZE;
1189 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1190 		goto bad;
1191 	} else {
1192 		u_char nextproto;
1193 
1194 		/*
1195 		 * Too large for the destination or interface;
1196 		 * fragment if possible.
1197 		 * Must be able to put at least 8 bytes per fragment.
1198 		 */
1199 		if (mtu > IPV6_MAXPACKET)
1200 			mtu = IPV6_MAXPACKET;
1201 
1202 		len = (mtu - unfragpartlen - sizeof(struct ip6_frag)) & ~7;
1203 		if (len < 8) {
1204 			error = EMSGSIZE;
1205 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
1206 			goto bad;
1207 		}
1208 
1209 		/*
1210 		 * If the interface will not calculate checksums on
1211 		 * fragmented packets, then do it here.
1212 		 * XXX-BZ handle the hw offloading case.  Need flags.
1213 		 */
1214 		ip6_output_delayed_csum(m, ifp, m->m_pkthdr.csum_flags, plen,
1215 		    optlen);
1216 
1217 		/*
1218 		 * Change the next header field of the last header in the
1219 		 * unfragmentable part.
1220 		 */
1221 		if (exthdrs.ip6e_rthdr) {
1222 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1223 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1224 		} else if (exthdrs.ip6e_dest1) {
1225 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1226 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1227 		} else if (exthdrs.ip6e_hbh) {
1228 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1229 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1230 		} else {
1231 			ip6 = mtod(m, struct ip6_hdr *);
1232 			nextproto = ip6->ip6_nxt;
1233 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1234 		}
1235 
1236 		/*
1237 		 * Loop through length of segment after first fragment,
1238 		 * make new header and copy data of each part and link onto
1239 		 * chain.
1240 		 */
1241 		m0 = m;
1242 		id = htonl(ip6_randomid());
1243 		error = ip6_fragment(ifp, m, unfragpartlen, nextproto,len, id);
1244 		if (error != 0)
1245 			goto sendorfree;
1246 
1247 		in6_ifstat_inc(ifp, ifs6_out_fragok);
1248 	}
1249 
1250 	/* Remove leading garbage. */
1251 sendorfree:
1252 	m = m0->m_nextpkt;
1253 	m0->m_nextpkt = 0;
1254 	m_freem(m0);
1255 	for (; m; m = m0) {
1256 		m0 = m->m_nextpkt;
1257 		m->m_nextpkt = 0;
1258 		if (error == 0) {
1259 			/* Record statistics for this interface address. */
1260 			if (ia) {
1261 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1262 				counter_u64_add(ia->ia_ifa.ifa_obytes,
1263 				    m->m_pkthdr.len);
1264 			}
1265 			if (vlan_pcp > -1)
1266 				EVL_APPLY_PRI(m, vlan_pcp);
1267 			error = ip6_output_send(inp, ifp, origifp, m, dst, ro,
1268 			    true);
1269 		} else
1270 			m_freem(m);
1271 	}
1272 
1273 	if (error == 0)
1274 		IP6STAT_INC(ip6s_fragmented);
1275 
1276 done:
1277 	return (error);
1278 
1279 freehdrs:
1280 	m_freem(exthdrs.ip6e_hbh);	/* m_freem() checks if mbuf is NULL. */
1281 	m_freem(exthdrs.ip6e_dest1);
1282 	m_freem(exthdrs.ip6e_rthdr);
1283 	m_freem(exthdrs.ip6e_dest2);
1284 	/* FALLTHROUGH */
1285 bad:
1286 	if (m)
1287 		m_freem(m);
1288 	goto done;
1289 }
1290 
1291 static int
1292 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1293 {
1294 	struct mbuf *m;
1295 
1296 	if (hlen > MCLBYTES)
1297 		return (ENOBUFS); /* XXX */
1298 
1299 	if (hlen > MLEN)
1300 		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1301 	else
1302 		m = m_get(M_NOWAIT, MT_DATA);
1303 	if (m == NULL)
1304 		return (ENOBUFS);
1305 	m->m_len = hlen;
1306 	if (hdr)
1307 		bcopy(hdr, mtod(m, caddr_t), hlen);
1308 
1309 	*mp = m;
1310 	return (0);
1311 }
1312 
1313 /*
1314  * Insert jumbo payload option.
1315  */
1316 static int
1317 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1318 {
1319 	struct mbuf *mopt;
1320 	u_char *optbuf;
1321 	u_int32_t v;
1322 
1323 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1324 
1325 	/*
1326 	 * If there is no hop-by-hop options header, allocate new one.
1327 	 * If there is one but it doesn't have enough space to store the
1328 	 * jumbo payload option, allocate a cluster to store the whole options.
1329 	 * Otherwise, use it to store the options.
1330 	 */
1331 	if (exthdrs->ip6e_hbh == NULL) {
1332 		mopt = m_get(M_NOWAIT, MT_DATA);
1333 		if (mopt == NULL)
1334 			return (ENOBUFS);
1335 		mopt->m_len = JUMBOOPTLEN;
1336 		optbuf = mtod(mopt, u_char *);
1337 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1338 		exthdrs->ip6e_hbh = mopt;
1339 	} else {
1340 		struct ip6_hbh *hbh;
1341 
1342 		mopt = exthdrs->ip6e_hbh;
1343 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1344 			/*
1345 			 * XXX assumption:
1346 			 * - exthdrs->ip6e_hbh is not referenced from places
1347 			 *   other than exthdrs.
1348 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1349 			 */
1350 			int oldoptlen = mopt->m_len;
1351 			struct mbuf *n;
1352 
1353 			/*
1354 			 * XXX: give up if the whole (new) hbh header does
1355 			 * not fit even in an mbuf cluster.
1356 			 */
1357 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1358 				return (ENOBUFS);
1359 
1360 			/*
1361 			 * As a consequence, we must always prepare a cluster
1362 			 * at this point.
1363 			 */
1364 			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1365 			if (n == NULL)
1366 				return (ENOBUFS);
1367 			n->m_len = oldoptlen + JUMBOOPTLEN;
1368 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1369 			    oldoptlen);
1370 			optbuf = mtod(n, caddr_t) + oldoptlen;
1371 			m_freem(mopt);
1372 			mopt = exthdrs->ip6e_hbh = n;
1373 		} else {
1374 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1375 			mopt->m_len += JUMBOOPTLEN;
1376 		}
1377 		optbuf[0] = IP6OPT_PADN;
1378 		optbuf[1] = 1;
1379 
1380 		/*
1381 		 * Adjust the header length according to the pad and
1382 		 * the jumbo payload option.
1383 		 */
1384 		hbh = mtod(mopt, struct ip6_hbh *);
1385 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1386 	}
1387 
1388 	/* fill in the option. */
1389 	optbuf[2] = IP6OPT_JUMBO;
1390 	optbuf[3] = 4;
1391 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1392 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1393 
1394 	/* finally, adjust the packet header length */
1395 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1396 
1397 	return (0);
1398 #undef JUMBOOPTLEN
1399 }
1400 
1401 /*
1402  * Insert fragment header and copy unfragmentable header portions.
1403  */
1404 static int
1405 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1406     struct ip6_frag **frghdrp)
1407 {
1408 	struct mbuf *n, *mlast;
1409 
1410 	if (hlen > sizeof(struct ip6_hdr)) {
1411 		n = m_copym(m0, sizeof(struct ip6_hdr),
1412 		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1413 		if (n == NULL)
1414 			return (ENOBUFS);
1415 		m->m_next = n;
1416 	} else
1417 		n = m;
1418 
1419 	/* Search for the last mbuf of unfragmentable part. */
1420 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1421 		;
1422 
1423 	if (M_WRITABLE(mlast) &&
1424 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1425 		/* use the trailing space of the last mbuf for the fragment hdr */
1426 		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1427 		    mlast->m_len);
1428 		mlast->m_len += sizeof(struct ip6_frag);
1429 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1430 	} else {
1431 		/* allocate a new mbuf for the fragment header */
1432 		struct mbuf *mfrg;
1433 
1434 		mfrg = m_get(M_NOWAIT, MT_DATA);
1435 		if (mfrg == NULL)
1436 			return (ENOBUFS);
1437 		mfrg->m_len = sizeof(struct ip6_frag);
1438 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1439 		mlast->m_next = mfrg;
1440 	}
1441 
1442 	return (0);
1443 }
1444 
1445 /*
1446  * Calculates IPv6 path mtu for destination @dst.
1447  * Resulting MTU is stored in @mtup.
1448  *
1449  * Returns 0 on success.
1450  */
1451 static int
1452 ip6_getpmtu_ctl(u_int fibnum, const struct in6_addr *dst, u_long *mtup)
1453 {
1454 	struct epoch_tracker et;
1455 	struct nhop_object *nh;
1456 	struct in6_addr kdst;
1457 	uint32_t scopeid;
1458 	int error;
1459 
1460 	in6_splitscope(dst, &kdst, &scopeid);
1461 
1462 	NET_EPOCH_ENTER(et);
1463 	nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE, 0);
1464 	if (nh != NULL)
1465 		error = ip6_calcmtu(nh->nh_ifp, dst, nh->nh_mtu, mtup, NULL, 0);
1466 	else
1467 		error = EHOSTUNREACH;
1468 	NET_EPOCH_EXIT(et);
1469 
1470 	return (error);
1471 }
1472 
1473 /*
1474  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1475  * and cached data in @ro_pmtu.
1476  * MTU from (successful) route lookup is saved (along with dst)
1477  * inside @ro_pmtu to avoid subsequent route lookups after packet
1478  * filter processing.
1479  *
1480  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1481  * Returns 0 on success.
1482  */
1483 static int
1484 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1485     struct ifnet *ifp, const struct in6_addr *dst, u_long *mtup,
1486     int *alwaysfragp, u_int fibnum, u_int proto)
1487 {
1488 	struct nhop_object *nh;
1489 	struct in6_addr kdst;
1490 	uint32_t scopeid;
1491 	struct sockaddr_in6 *sa6_dst, sin6;
1492 	u_long mtu;
1493 
1494 	NET_EPOCH_ASSERT();
1495 
1496 	mtu = 0;
1497 	if (ro_pmtu == NULL || do_lookup) {
1498 		/*
1499 		 * Here ro_pmtu has final destination address, while
1500 		 * ro might represent immediate destination.
1501 		 * Use ro_pmtu destination since mtu might differ.
1502 		 */
1503 		if (ro_pmtu != NULL) {
1504 			sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1505 			if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1506 				ro_pmtu->ro_mtu = 0;
1507 		} else
1508 			sa6_dst = &sin6;
1509 
1510 		if (ro_pmtu == NULL || ro_pmtu->ro_mtu == 0) {
1511 			bzero(sa6_dst, sizeof(*sa6_dst));
1512 			sa6_dst->sin6_family = AF_INET6;
1513 			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1514 			sa6_dst->sin6_addr = *dst;
1515 
1516 			in6_splitscope(dst, &kdst, &scopeid);
1517 			nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE, 0);
1518 			if (nh != NULL) {
1519 				mtu = nh->nh_mtu;
1520 				if (ro_pmtu != NULL)
1521 					ro_pmtu->ro_mtu = mtu;
1522 			}
1523 		} else
1524 			mtu = ro_pmtu->ro_mtu;
1525 	}
1526 
1527 	if (ro_pmtu != NULL && ro_pmtu->ro_nh != NULL)
1528 		mtu = ro_pmtu->ro_nh->nh_mtu;
1529 
1530 	return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp, proto));
1531 }
1532 
1533 /*
1534  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1535  * hostcache data for @dst.
1536  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1537  *
1538  * Returns 0 on success.
1539  */
1540 static int
1541 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1542     u_long *mtup, int *alwaysfragp, u_int proto)
1543 {
1544 	u_long mtu = 0;
1545 	int alwaysfrag = 0;
1546 	int error = 0;
1547 
1548 	if (rt_mtu > 0) {
1549 		u_int32_t ifmtu;
1550 		struct in_conninfo inc;
1551 
1552 		bzero(&inc, sizeof(inc));
1553 		inc.inc_flags |= INC_ISIPV6;
1554 		inc.inc6_faddr = *dst;
1555 
1556 		ifmtu = IN6_LINKMTU(ifp);
1557 
1558 		/* TCP is known to react to pmtu changes so skip hc */
1559 		if (proto != IPPROTO_TCP)
1560 			mtu = tcp_hc_getmtu(&inc);
1561 
1562 		if (mtu)
1563 			mtu = min(mtu, rt_mtu);
1564 		else
1565 			mtu = rt_mtu;
1566 		if (mtu == 0)
1567 			mtu = ifmtu;
1568 		else if (mtu < IPV6_MMTU) {
1569 			/*
1570 			 * RFC2460 section 5, last paragraph:
1571 			 * if we record ICMPv6 too big message with
1572 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1573 			 * or smaller, with framgent header attached.
1574 			 * (fragment header is needed regardless from the
1575 			 * packet size, for translators to identify packets)
1576 			 */
1577 			alwaysfrag = 1;
1578 			mtu = IPV6_MMTU;
1579 		}
1580 	} else if (ifp) {
1581 		mtu = IN6_LINKMTU(ifp);
1582 	} else
1583 		error = EHOSTUNREACH; /* XXX */
1584 
1585 	*mtup = mtu;
1586 	if (alwaysfragp)
1587 		*alwaysfragp = alwaysfrag;
1588 	return (error);
1589 }
1590 
1591 /*
1592  * IP6 socket option processing.
1593  */
1594 int
1595 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1596 {
1597 	int optdatalen, uproto;
1598 	void *optdata;
1599 	struct inpcb *inp = sotoinpcb(so);
1600 	int error, optval;
1601 	int level, op, optname;
1602 	int optlen;
1603 	struct thread *td;
1604 #ifdef	RSS
1605 	uint32_t rss_bucket;
1606 	int retval;
1607 #endif
1608 
1609 /*
1610  * Don't use more than a quarter of mbuf clusters.  N.B.:
1611  * nmbclusters is an int, but nmbclusters * MCLBYTES may overflow
1612  * on LP64 architectures, so cast to u_long to avoid undefined
1613  * behavior.  ILP32 architectures cannot have nmbclusters
1614  * large enough to overflow for other reasons.
1615  */
1616 #define IPV6_PKTOPTIONS_MBUF_LIMIT	((u_long)nmbclusters * MCLBYTES / 4)
1617 
1618 	level = sopt->sopt_level;
1619 	op = sopt->sopt_dir;
1620 	optname = sopt->sopt_name;
1621 	optlen = sopt->sopt_valsize;
1622 	td = sopt->sopt_td;
1623 	error = 0;
1624 	optval = 0;
1625 	uproto = (int)so->so_proto->pr_protocol;
1626 
1627 	if (level != IPPROTO_IPV6) {
1628 		error = EINVAL;
1629 
1630 		if (sopt->sopt_level == SOL_SOCKET &&
1631 		    sopt->sopt_dir == SOPT_SET) {
1632 			switch (sopt->sopt_name) {
1633 			case SO_REUSEADDR:
1634 				INP_WLOCK(inp);
1635 				if ((so->so_options & SO_REUSEADDR) != 0)
1636 					inp->inp_flags2 |= INP_REUSEADDR;
1637 				else
1638 					inp->inp_flags2 &= ~INP_REUSEADDR;
1639 				INP_WUNLOCK(inp);
1640 				error = 0;
1641 				break;
1642 			case SO_REUSEPORT:
1643 				INP_WLOCK(inp);
1644 				if ((so->so_options & SO_REUSEPORT) != 0)
1645 					inp->inp_flags2 |= INP_REUSEPORT;
1646 				else
1647 					inp->inp_flags2 &= ~INP_REUSEPORT;
1648 				INP_WUNLOCK(inp);
1649 				error = 0;
1650 				break;
1651 			case SO_REUSEPORT_LB:
1652 				INP_WLOCK(inp);
1653 				if ((so->so_options & SO_REUSEPORT_LB) != 0)
1654 					inp->inp_flags2 |= INP_REUSEPORT_LB;
1655 				else
1656 					inp->inp_flags2 &= ~INP_REUSEPORT_LB;
1657 				INP_WUNLOCK(inp);
1658 				error = 0;
1659 				break;
1660 			case SO_SETFIB:
1661 				INP_WLOCK(inp);
1662 				inp->inp_inc.inc_fibnum = so->so_fibnum;
1663 				INP_WUNLOCK(inp);
1664 				error = 0;
1665 				break;
1666 			case SO_MAX_PACING_RATE:
1667 #ifdef RATELIMIT
1668 				INP_WLOCK(inp);
1669 				inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1670 				INP_WUNLOCK(inp);
1671 				error = 0;
1672 #else
1673 				error = EOPNOTSUPP;
1674 #endif
1675 				break;
1676 			default:
1677 				break;
1678 			}
1679 		}
1680 	} else {		/* level == IPPROTO_IPV6 */
1681 		switch (op) {
1682 		case SOPT_SET:
1683 			switch (optname) {
1684 			case IPV6_2292PKTOPTIONS:
1685 #ifdef IPV6_PKTOPTIONS
1686 			case IPV6_PKTOPTIONS:
1687 #endif
1688 			{
1689 				struct mbuf *m;
1690 
1691 				if (optlen > IPV6_PKTOPTIONS_MBUF_LIMIT) {
1692 					printf("ip6_ctloutput: mbuf limit hit\n");
1693 					error = ENOBUFS;
1694 					break;
1695 				}
1696 
1697 				error = soopt_getm(sopt, &m); /* XXX */
1698 				if (error != 0)
1699 					break;
1700 				error = soopt_mcopyin(sopt, m); /* XXX */
1701 				if (error != 0)
1702 					break;
1703 				INP_WLOCK(inp);
1704 				error = ip6_pcbopts(&inp->in6p_outputopts, m,
1705 				    so, sopt);
1706 				INP_WUNLOCK(inp);
1707 				m_freem(m); /* XXX */
1708 				break;
1709 			}
1710 
1711 			/*
1712 			 * Use of some Hop-by-Hop options or some
1713 			 * Destination options, might require special
1714 			 * privilege.  That is, normal applications
1715 			 * (without special privilege) might be forbidden
1716 			 * from setting certain options in outgoing packets,
1717 			 * and might never see certain options in received
1718 			 * packets. [RFC 2292 Section 6]
1719 			 * KAME specific note:
1720 			 *  KAME prevents non-privileged users from sending or
1721 			 *  receiving ANY hbh/dst options in order to avoid
1722 			 *  overhead of parsing options in the kernel.
1723 			 */
1724 			case IPV6_RECVHOPOPTS:
1725 			case IPV6_RECVDSTOPTS:
1726 			case IPV6_RECVRTHDRDSTOPTS:
1727 				if (td != NULL) {
1728 					error = priv_check(td,
1729 					    PRIV_NETINET_SETHDROPTS);
1730 					if (error)
1731 						break;
1732 				}
1733 				/* FALLTHROUGH */
1734 			case IPV6_UNICAST_HOPS:
1735 			case IPV6_HOPLIMIT:
1736 
1737 			case IPV6_RECVPKTINFO:
1738 			case IPV6_RECVHOPLIMIT:
1739 			case IPV6_RECVRTHDR:
1740 			case IPV6_RECVPATHMTU:
1741 			case IPV6_RECVTCLASS:
1742 			case IPV6_RECVFLOWID:
1743 #ifdef	RSS
1744 			case IPV6_RECVRSSBUCKETID:
1745 #endif
1746 			case IPV6_V6ONLY:
1747 			case IPV6_AUTOFLOWLABEL:
1748 			case IPV6_ORIGDSTADDR:
1749 			case IPV6_BINDANY:
1750 			case IPV6_BINDMULTI:
1751 #ifdef	RSS
1752 			case IPV6_RSS_LISTEN_BUCKET:
1753 #endif
1754 			case IPV6_VLAN_PCP:
1755 				if (optname == IPV6_BINDANY && td != NULL) {
1756 					error = priv_check(td,
1757 					    PRIV_NETINET_BINDANY);
1758 					if (error)
1759 						break;
1760 				}
1761 
1762 				if (optlen != sizeof(int)) {
1763 					error = EINVAL;
1764 					break;
1765 				}
1766 				error = sooptcopyin(sopt, &optval,
1767 					sizeof optval, sizeof optval);
1768 				if (error)
1769 					break;
1770 				switch (optname) {
1771 				case IPV6_UNICAST_HOPS:
1772 					if (optval < -1 || optval >= 256)
1773 						error = EINVAL;
1774 					else {
1775 						/* -1 = kernel default */
1776 						inp->in6p_hops = optval;
1777 						if ((inp->inp_vflag &
1778 						     INP_IPV4) != 0)
1779 							inp->inp_ip_ttl = optval;
1780 					}
1781 					break;
1782 #define OPTSET(bit) \
1783 do { \
1784 	INP_WLOCK(inp); \
1785 	if (optval) \
1786 		inp->inp_flags |= (bit); \
1787 	else \
1788 		inp->inp_flags &= ~(bit); \
1789 	INP_WUNLOCK(inp); \
1790 } while (/*CONSTCOND*/ 0)
1791 #define OPTSET2292(bit) \
1792 do { \
1793 	INP_WLOCK(inp); \
1794 	inp->inp_flags |= IN6P_RFC2292; \
1795 	if (optval) \
1796 		inp->inp_flags |= (bit); \
1797 	else \
1798 		inp->inp_flags &= ~(bit); \
1799 	INP_WUNLOCK(inp); \
1800 } while (/*CONSTCOND*/ 0)
1801 #define OPTBIT(bit) (inp->inp_flags & (bit) ? 1 : 0)
1802 
1803 #define OPTSET2_N(bit, val) do {					\
1804 	if (val)							\
1805 		inp->inp_flags2 |= bit;					\
1806 	else								\
1807 		inp->inp_flags2 &= ~bit;				\
1808 } while (0)
1809 #define OPTSET2(bit, val) do {						\
1810 	INP_WLOCK(inp);							\
1811 	OPTSET2_N(bit, val);						\
1812 	INP_WUNLOCK(inp);						\
1813 } while (0)
1814 #define OPTBIT2(bit) (inp->inp_flags2 & (bit) ? 1 : 0)
1815 #define OPTSET2292_EXCLUSIVE(bit)					\
1816 do {									\
1817 	INP_WLOCK(inp);							\
1818 	if (OPTBIT(IN6P_RFC2292)) {					\
1819 		error = EINVAL;						\
1820 	} else {							\
1821 		if (optval)						\
1822 			inp->inp_flags |= (bit);			\
1823 		else							\
1824 			inp->inp_flags &= ~(bit);			\
1825 	}								\
1826 	INP_WUNLOCK(inp);						\
1827 } while (/*CONSTCOND*/ 0)
1828 
1829 				case IPV6_RECVPKTINFO:
1830 					OPTSET2292_EXCLUSIVE(IN6P_PKTINFO);
1831 					break;
1832 
1833 				case IPV6_HOPLIMIT:
1834 				{
1835 					struct ip6_pktopts **optp;
1836 
1837 					/* cannot mix with RFC2292 */
1838 					if (OPTBIT(IN6P_RFC2292)) {
1839 						error = EINVAL;
1840 						break;
1841 					}
1842 					INP_WLOCK(inp);
1843 					if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1844 						INP_WUNLOCK(inp);
1845 						return (ECONNRESET);
1846 					}
1847 					optp = &inp->in6p_outputopts;
1848 					error = ip6_pcbopt(IPV6_HOPLIMIT,
1849 					    (u_char *)&optval, sizeof(optval),
1850 					    optp, (td != NULL) ? td->td_ucred :
1851 					    NULL, uproto);
1852 					INP_WUNLOCK(inp);
1853 					break;
1854 				}
1855 
1856 				case IPV6_RECVHOPLIMIT:
1857 					OPTSET2292_EXCLUSIVE(IN6P_HOPLIMIT);
1858 					break;
1859 
1860 				case IPV6_RECVHOPOPTS:
1861 					OPTSET2292_EXCLUSIVE(IN6P_HOPOPTS);
1862 					break;
1863 
1864 				case IPV6_RECVDSTOPTS:
1865 					OPTSET2292_EXCLUSIVE(IN6P_DSTOPTS);
1866 					break;
1867 
1868 				case IPV6_RECVRTHDRDSTOPTS:
1869 					OPTSET2292_EXCLUSIVE(IN6P_RTHDRDSTOPTS);
1870 					break;
1871 
1872 				case IPV6_RECVRTHDR:
1873 					OPTSET2292_EXCLUSIVE(IN6P_RTHDR);
1874 					break;
1875 
1876 				case IPV6_RECVPATHMTU:
1877 					/*
1878 					 * We ignore this option for TCP
1879 					 * sockets.
1880 					 * (RFC3542 leaves this case
1881 					 * unspecified.)
1882 					 */
1883 					if (uproto != IPPROTO_TCP)
1884 						OPTSET(IN6P_MTU);
1885 					break;
1886 
1887 				case IPV6_RECVFLOWID:
1888 					OPTSET2(INP_RECVFLOWID, optval);
1889 					break;
1890 
1891 #ifdef	RSS
1892 				case IPV6_RECVRSSBUCKETID:
1893 					OPTSET2(INP_RECVRSSBUCKETID, optval);
1894 					break;
1895 #endif
1896 
1897 				case IPV6_V6ONLY:
1898 					INP_WLOCK(inp);
1899 					if (inp->inp_lport ||
1900 					    !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
1901 						/*
1902 						 * The socket is already bound.
1903 						 */
1904 						INP_WUNLOCK(inp);
1905 						error = EINVAL;
1906 						break;
1907 					}
1908 					if (optval) {
1909 						inp->inp_flags |= IN6P_IPV6_V6ONLY;
1910 						inp->inp_vflag &= ~INP_IPV4;
1911 					} else {
1912 						inp->inp_flags &= ~IN6P_IPV6_V6ONLY;
1913 						inp->inp_vflag |= INP_IPV4;
1914 					}
1915 					INP_WUNLOCK(inp);
1916 					break;
1917 				case IPV6_RECVTCLASS:
1918 					/* cannot mix with RFC2292 XXX */
1919 					OPTSET2292_EXCLUSIVE(IN6P_TCLASS);
1920 					break;
1921 				case IPV6_AUTOFLOWLABEL:
1922 					OPTSET(IN6P_AUTOFLOWLABEL);
1923 					break;
1924 
1925 				case IPV6_ORIGDSTADDR:
1926 					OPTSET2(INP_ORIGDSTADDR, optval);
1927 					break;
1928 				case IPV6_BINDANY:
1929 					OPTSET(INP_BINDANY);
1930 					break;
1931 
1932 				case IPV6_BINDMULTI:
1933 					OPTSET2(INP_BINDMULTI, optval);
1934 					break;
1935 #ifdef	RSS
1936 				case IPV6_RSS_LISTEN_BUCKET:
1937 					if ((optval >= 0) &&
1938 					    (optval < rss_getnumbuckets())) {
1939 						INP_WLOCK(inp);
1940 						inp->inp_rss_listen_bucket = optval;
1941 						OPTSET2_N(INP_RSS_BUCKET_SET, 1);
1942 						INP_WUNLOCK(inp);
1943 					} else {
1944 						error = EINVAL;
1945 					}
1946 					break;
1947 #endif
1948 				case IPV6_VLAN_PCP:
1949 					if ((optval >= -1) && (optval <=
1950 					    (INP_2PCP_MASK >> INP_2PCP_SHIFT))) {
1951 						if (optval == -1) {
1952 							INP_WLOCK(inp);
1953 							inp->inp_flags2 &=
1954 							    ~(INP_2PCP_SET |
1955 							    INP_2PCP_MASK);
1956 							INP_WUNLOCK(inp);
1957 						} else {
1958 							INP_WLOCK(inp);
1959 							inp->inp_flags2 |=
1960 							    INP_2PCP_SET;
1961 							inp->inp_flags2 &=
1962 							    ~INP_2PCP_MASK;
1963 							inp->inp_flags2 |=
1964 							    optval <<
1965 							    INP_2PCP_SHIFT;
1966 							INP_WUNLOCK(inp);
1967 						}
1968 					} else
1969 						error = EINVAL;
1970 					break;
1971 				}
1972 				break;
1973 
1974 			case IPV6_TCLASS:
1975 			case IPV6_DONTFRAG:
1976 			case IPV6_USE_MIN_MTU:
1977 			case IPV6_PREFER_TEMPADDR:
1978 				if (optlen != sizeof(optval)) {
1979 					error = EINVAL;
1980 					break;
1981 				}
1982 				error = sooptcopyin(sopt, &optval,
1983 					sizeof optval, sizeof optval);
1984 				if (error)
1985 					break;
1986 				{
1987 					struct ip6_pktopts **optp;
1988 					INP_WLOCK(inp);
1989 					if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1990 						INP_WUNLOCK(inp);
1991 						return (ECONNRESET);
1992 					}
1993 					optp = &inp->in6p_outputopts;
1994 					error = ip6_pcbopt(optname,
1995 					    (u_char *)&optval, sizeof(optval),
1996 					    optp, (td != NULL) ? td->td_ucred :
1997 					    NULL, uproto);
1998 					INP_WUNLOCK(inp);
1999 					break;
2000 				}
2001 
2002 			case IPV6_2292PKTINFO:
2003 			case IPV6_2292HOPLIMIT:
2004 			case IPV6_2292HOPOPTS:
2005 			case IPV6_2292DSTOPTS:
2006 			case IPV6_2292RTHDR:
2007 				/* RFC 2292 */
2008 				if (optlen != sizeof(int)) {
2009 					error = EINVAL;
2010 					break;
2011 				}
2012 				error = sooptcopyin(sopt, &optval,
2013 					sizeof optval, sizeof optval);
2014 				if (error)
2015 					break;
2016 				switch (optname) {
2017 				case IPV6_2292PKTINFO:
2018 					OPTSET2292(IN6P_PKTINFO);
2019 					break;
2020 				case IPV6_2292HOPLIMIT:
2021 					OPTSET2292(IN6P_HOPLIMIT);
2022 					break;
2023 				case IPV6_2292HOPOPTS:
2024 					/*
2025 					 * Check super-user privilege.
2026 					 * See comments for IPV6_RECVHOPOPTS.
2027 					 */
2028 					if (td != NULL) {
2029 						error = priv_check(td,
2030 						    PRIV_NETINET_SETHDROPTS);
2031 						if (error)
2032 							return (error);
2033 					}
2034 					OPTSET2292(IN6P_HOPOPTS);
2035 					break;
2036 				case IPV6_2292DSTOPTS:
2037 					if (td != NULL) {
2038 						error = priv_check(td,
2039 						    PRIV_NETINET_SETHDROPTS);
2040 						if (error)
2041 							return (error);
2042 					}
2043 					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
2044 					break;
2045 				case IPV6_2292RTHDR:
2046 					OPTSET2292(IN6P_RTHDR);
2047 					break;
2048 				}
2049 				break;
2050 			case IPV6_PKTINFO:
2051 			case IPV6_HOPOPTS:
2052 			case IPV6_RTHDR:
2053 			case IPV6_DSTOPTS:
2054 			case IPV6_RTHDRDSTOPTS:
2055 			case IPV6_NEXTHOP:
2056 			{
2057 				/* new advanced API (RFC3542) */
2058 				u_char *optbuf;
2059 				u_char optbuf_storage[MCLBYTES];
2060 				int optlen;
2061 				struct ip6_pktopts **optp;
2062 
2063 				/* cannot mix with RFC2292 */
2064 				if (OPTBIT(IN6P_RFC2292)) {
2065 					error = EINVAL;
2066 					break;
2067 				}
2068 
2069 				/*
2070 				 * We only ensure valsize is not too large
2071 				 * here.  Further validation will be done
2072 				 * later.
2073 				 */
2074 				error = sooptcopyin(sopt, optbuf_storage,
2075 				    sizeof(optbuf_storage), 0);
2076 				if (error)
2077 					break;
2078 				optlen = sopt->sopt_valsize;
2079 				optbuf = optbuf_storage;
2080 				INP_WLOCK(inp);
2081 				if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
2082 					INP_WUNLOCK(inp);
2083 					return (ECONNRESET);
2084 				}
2085 				optp = &inp->in6p_outputopts;
2086 				error = ip6_pcbopt(optname, optbuf, optlen,
2087 				    optp, (td != NULL) ? td->td_ucred : NULL,
2088 				    uproto);
2089 				INP_WUNLOCK(inp);
2090 				break;
2091 			}
2092 #undef OPTSET
2093 
2094 			case IPV6_MULTICAST_IF:
2095 			case IPV6_MULTICAST_HOPS:
2096 			case IPV6_MULTICAST_LOOP:
2097 			case IPV6_JOIN_GROUP:
2098 			case IPV6_LEAVE_GROUP:
2099 			case IPV6_MSFILTER:
2100 			case MCAST_BLOCK_SOURCE:
2101 			case MCAST_UNBLOCK_SOURCE:
2102 			case MCAST_JOIN_GROUP:
2103 			case MCAST_LEAVE_GROUP:
2104 			case MCAST_JOIN_SOURCE_GROUP:
2105 			case MCAST_LEAVE_SOURCE_GROUP:
2106 				error = ip6_setmoptions(inp, sopt);
2107 				break;
2108 
2109 			case IPV6_PORTRANGE:
2110 				error = sooptcopyin(sopt, &optval,
2111 				    sizeof optval, sizeof optval);
2112 				if (error)
2113 					break;
2114 
2115 				INP_WLOCK(inp);
2116 				switch (optval) {
2117 				case IPV6_PORTRANGE_DEFAULT:
2118 					inp->inp_flags &= ~(INP_LOWPORT);
2119 					inp->inp_flags &= ~(INP_HIGHPORT);
2120 					break;
2121 
2122 				case IPV6_PORTRANGE_HIGH:
2123 					inp->inp_flags &= ~(INP_LOWPORT);
2124 					inp->inp_flags |= INP_HIGHPORT;
2125 					break;
2126 
2127 				case IPV6_PORTRANGE_LOW:
2128 					inp->inp_flags &= ~(INP_HIGHPORT);
2129 					inp->inp_flags |= INP_LOWPORT;
2130 					break;
2131 
2132 				default:
2133 					error = EINVAL;
2134 					break;
2135 				}
2136 				INP_WUNLOCK(inp);
2137 				break;
2138 
2139 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2140 			case IPV6_IPSEC_POLICY:
2141 				if (IPSEC_ENABLED(ipv6)) {
2142 					error = IPSEC_PCBCTL(ipv6, inp, sopt);
2143 					break;
2144 				}
2145 				/* FALLTHROUGH */
2146 #endif /* IPSEC */
2147 
2148 			default:
2149 				error = ENOPROTOOPT;
2150 				break;
2151 			}
2152 			break;
2153 
2154 		case SOPT_GET:
2155 			switch (optname) {
2156 			case IPV6_2292PKTOPTIONS:
2157 #ifdef IPV6_PKTOPTIONS
2158 			case IPV6_PKTOPTIONS:
2159 #endif
2160 				/*
2161 				 * RFC3542 (effectively) deprecated the
2162 				 * semantics of the 2292-style pktoptions.
2163 				 * Since it was not reliable in nature (i.e.,
2164 				 * applications had to expect the lack of some
2165 				 * information after all), it would make sense
2166 				 * to simplify this part by always returning
2167 				 * empty data.
2168 				 */
2169 				sopt->sopt_valsize = 0;
2170 				break;
2171 
2172 			case IPV6_RECVHOPOPTS:
2173 			case IPV6_RECVDSTOPTS:
2174 			case IPV6_RECVRTHDRDSTOPTS:
2175 			case IPV6_UNICAST_HOPS:
2176 			case IPV6_RECVPKTINFO:
2177 			case IPV6_RECVHOPLIMIT:
2178 			case IPV6_RECVRTHDR:
2179 			case IPV6_RECVPATHMTU:
2180 
2181 			case IPV6_V6ONLY:
2182 			case IPV6_PORTRANGE:
2183 			case IPV6_RECVTCLASS:
2184 			case IPV6_AUTOFLOWLABEL:
2185 			case IPV6_BINDANY:
2186 			case IPV6_FLOWID:
2187 			case IPV6_FLOWTYPE:
2188 			case IPV6_RECVFLOWID:
2189 #ifdef	RSS
2190 			case IPV6_RSSBUCKETID:
2191 			case IPV6_RECVRSSBUCKETID:
2192 #endif
2193 			case IPV6_BINDMULTI:
2194 			case IPV6_VLAN_PCP:
2195 				switch (optname) {
2196 				case IPV6_RECVHOPOPTS:
2197 					optval = OPTBIT(IN6P_HOPOPTS);
2198 					break;
2199 
2200 				case IPV6_RECVDSTOPTS:
2201 					optval = OPTBIT(IN6P_DSTOPTS);
2202 					break;
2203 
2204 				case IPV6_RECVRTHDRDSTOPTS:
2205 					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
2206 					break;
2207 
2208 				case IPV6_UNICAST_HOPS:
2209 					optval = inp->in6p_hops;
2210 					break;
2211 
2212 				case IPV6_RECVPKTINFO:
2213 					optval = OPTBIT(IN6P_PKTINFO);
2214 					break;
2215 
2216 				case IPV6_RECVHOPLIMIT:
2217 					optval = OPTBIT(IN6P_HOPLIMIT);
2218 					break;
2219 
2220 				case IPV6_RECVRTHDR:
2221 					optval = OPTBIT(IN6P_RTHDR);
2222 					break;
2223 
2224 				case IPV6_RECVPATHMTU:
2225 					optval = OPTBIT(IN6P_MTU);
2226 					break;
2227 
2228 				case IPV6_V6ONLY:
2229 					optval = OPTBIT(IN6P_IPV6_V6ONLY);
2230 					break;
2231 
2232 				case IPV6_PORTRANGE:
2233 				    {
2234 					int flags;
2235 					flags = inp->inp_flags;
2236 					if (flags & INP_HIGHPORT)
2237 						optval = IPV6_PORTRANGE_HIGH;
2238 					else if (flags & INP_LOWPORT)
2239 						optval = IPV6_PORTRANGE_LOW;
2240 					else
2241 						optval = 0;
2242 					break;
2243 				    }
2244 				case IPV6_RECVTCLASS:
2245 					optval = OPTBIT(IN6P_TCLASS);
2246 					break;
2247 
2248 				case IPV6_AUTOFLOWLABEL:
2249 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2250 					break;
2251 
2252 				case IPV6_ORIGDSTADDR:
2253 					optval = OPTBIT2(INP_ORIGDSTADDR);
2254 					break;
2255 
2256 				case IPV6_BINDANY:
2257 					optval = OPTBIT(INP_BINDANY);
2258 					break;
2259 
2260 				case IPV6_FLOWID:
2261 					optval = inp->inp_flowid;
2262 					break;
2263 
2264 				case IPV6_FLOWTYPE:
2265 					optval = inp->inp_flowtype;
2266 					break;
2267 
2268 				case IPV6_RECVFLOWID:
2269 					optval = OPTBIT2(INP_RECVFLOWID);
2270 					break;
2271 #ifdef	RSS
2272 				case IPV6_RSSBUCKETID:
2273 					retval =
2274 					    rss_hash2bucket(inp->inp_flowid,
2275 					    inp->inp_flowtype,
2276 					    &rss_bucket);
2277 					if (retval == 0)
2278 						optval = rss_bucket;
2279 					else
2280 						error = EINVAL;
2281 					break;
2282 
2283 				case IPV6_RECVRSSBUCKETID:
2284 					optval = OPTBIT2(INP_RECVRSSBUCKETID);
2285 					break;
2286 #endif
2287 
2288 				case IPV6_BINDMULTI:
2289 					optval = OPTBIT2(INP_BINDMULTI);
2290 					break;
2291 
2292 				case IPV6_VLAN_PCP:
2293 					if (OPTBIT2(INP_2PCP_SET)) {
2294 						optval = (inp->inp_flags2 &
2295 							    INP_2PCP_MASK) >>
2296 							    INP_2PCP_SHIFT;
2297 					} else {
2298 						optval = -1;
2299 					}
2300 					break;
2301 				}
2302 
2303 				if (error)
2304 					break;
2305 				error = sooptcopyout(sopt, &optval,
2306 					sizeof optval);
2307 				break;
2308 
2309 			case IPV6_PATHMTU:
2310 			{
2311 				u_long pmtu = 0;
2312 				struct ip6_mtuinfo mtuinfo;
2313 				struct in6_addr addr;
2314 
2315 				if (!(so->so_state & SS_ISCONNECTED))
2316 					return (ENOTCONN);
2317 				/*
2318 				 * XXX: we dot not consider the case of source
2319 				 * routing, or optional information to specify
2320 				 * the outgoing interface.
2321 				 * Copy faddr out of inp to avoid holding lock
2322 				 * on inp during route lookup.
2323 				 */
2324 				INP_RLOCK(inp);
2325 				bcopy(&inp->in6p_faddr, &addr, sizeof(addr));
2326 				INP_RUNLOCK(inp);
2327 				error = ip6_getpmtu_ctl(so->so_fibnum,
2328 				    &addr, &pmtu);
2329 				if (error)
2330 					break;
2331 				if (pmtu > IPV6_MAXPACKET)
2332 					pmtu = IPV6_MAXPACKET;
2333 
2334 				bzero(&mtuinfo, sizeof(mtuinfo));
2335 				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2336 				optdata = (void *)&mtuinfo;
2337 				optdatalen = sizeof(mtuinfo);
2338 				error = sooptcopyout(sopt, optdata,
2339 				    optdatalen);
2340 				break;
2341 			}
2342 
2343 			case IPV6_2292PKTINFO:
2344 			case IPV6_2292HOPLIMIT:
2345 			case IPV6_2292HOPOPTS:
2346 			case IPV6_2292RTHDR:
2347 			case IPV6_2292DSTOPTS:
2348 				switch (optname) {
2349 				case IPV6_2292PKTINFO:
2350 					optval = OPTBIT(IN6P_PKTINFO);
2351 					break;
2352 				case IPV6_2292HOPLIMIT:
2353 					optval = OPTBIT(IN6P_HOPLIMIT);
2354 					break;
2355 				case IPV6_2292HOPOPTS:
2356 					optval = OPTBIT(IN6P_HOPOPTS);
2357 					break;
2358 				case IPV6_2292RTHDR:
2359 					optval = OPTBIT(IN6P_RTHDR);
2360 					break;
2361 				case IPV6_2292DSTOPTS:
2362 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2363 					break;
2364 				}
2365 				error = sooptcopyout(sopt, &optval,
2366 				    sizeof optval);
2367 				break;
2368 			case IPV6_PKTINFO:
2369 			case IPV6_HOPOPTS:
2370 			case IPV6_RTHDR:
2371 			case IPV6_DSTOPTS:
2372 			case IPV6_RTHDRDSTOPTS:
2373 			case IPV6_NEXTHOP:
2374 			case IPV6_TCLASS:
2375 			case IPV6_DONTFRAG:
2376 			case IPV6_USE_MIN_MTU:
2377 			case IPV6_PREFER_TEMPADDR:
2378 				error = ip6_getpcbopt(inp, optname, sopt);
2379 				break;
2380 
2381 			case IPV6_MULTICAST_IF:
2382 			case IPV6_MULTICAST_HOPS:
2383 			case IPV6_MULTICAST_LOOP:
2384 			case IPV6_MSFILTER:
2385 				error = ip6_getmoptions(inp, sopt);
2386 				break;
2387 
2388 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2389 			case IPV6_IPSEC_POLICY:
2390 				if (IPSEC_ENABLED(ipv6)) {
2391 					error = IPSEC_PCBCTL(ipv6, inp, sopt);
2392 					break;
2393 				}
2394 				/* FALLTHROUGH */
2395 #endif /* IPSEC */
2396 			default:
2397 				error = ENOPROTOOPT;
2398 				break;
2399 			}
2400 			break;
2401 		}
2402 	}
2403 	return (error);
2404 }
2405 
2406 int
2407 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2408 {
2409 	int error = 0, optval, optlen;
2410 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2411 	struct inpcb *inp = sotoinpcb(so);
2412 	int level, op, optname;
2413 
2414 	level = sopt->sopt_level;
2415 	op = sopt->sopt_dir;
2416 	optname = sopt->sopt_name;
2417 	optlen = sopt->sopt_valsize;
2418 
2419 	if (level != IPPROTO_IPV6) {
2420 		return (EINVAL);
2421 	}
2422 
2423 	switch (optname) {
2424 	case IPV6_CHECKSUM:
2425 		/*
2426 		 * For ICMPv6 sockets, no modification allowed for checksum
2427 		 * offset, permit "no change" values to help existing apps.
2428 		 *
2429 		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2430 		 * for an ICMPv6 socket will fail."
2431 		 * The current behavior does not meet RFC3542.
2432 		 */
2433 		switch (op) {
2434 		case SOPT_SET:
2435 			if (optlen != sizeof(int)) {
2436 				error = EINVAL;
2437 				break;
2438 			}
2439 			error = sooptcopyin(sopt, &optval, sizeof(optval),
2440 					    sizeof(optval));
2441 			if (error)
2442 				break;
2443 			if (optval < -1 || (optval % 2) != 0) {
2444 				/*
2445 				 * The API assumes non-negative even offset
2446 				 * values or -1 as a special value.
2447 				 */
2448 				error = EINVAL;
2449 			} else if (so->so_proto->pr_protocol ==
2450 			    IPPROTO_ICMPV6) {
2451 				if (optval != icmp6off)
2452 					error = EINVAL;
2453 			} else
2454 				inp->in6p_cksum = optval;
2455 			break;
2456 
2457 		case SOPT_GET:
2458 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2459 				optval = icmp6off;
2460 			else
2461 				optval = inp->in6p_cksum;
2462 
2463 			error = sooptcopyout(sopt, &optval, sizeof(optval));
2464 			break;
2465 
2466 		default:
2467 			error = EINVAL;
2468 			break;
2469 		}
2470 		break;
2471 
2472 	default:
2473 		error = ENOPROTOOPT;
2474 		break;
2475 	}
2476 
2477 	return (error);
2478 }
2479 
2480 /*
2481  * Set up IP6 options in pcb for insertion in output packets or
2482  * specifying behavior of outgoing packets.
2483  */
2484 static int
2485 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2486     struct socket *so, struct sockopt *sopt)
2487 {
2488 	struct ip6_pktopts *opt = *pktopt;
2489 	int error = 0;
2490 	struct thread *td = sopt->sopt_td;
2491 	struct epoch_tracker et;
2492 
2493 	/* turn off any old options. */
2494 	if (opt) {
2495 #ifdef DIAGNOSTIC
2496 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2497 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2498 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2499 			printf("ip6_pcbopts: all specified options are cleared.\n");
2500 #endif
2501 		ip6_clearpktopts(opt, -1);
2502 	} else {
2503 		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
2504 		if (opt == NULL)
2505 			return (ENOMEM);
2506 	}
2507 	*pktopt = NULL;
2508 
2509 	if (!m || m->m_len == 0) {
2510 		/*
2511 		 * Only turning off any previous options, regardless of
2512 		 * whether the opt is just created or given.
2513 		 */
2514 		free(opt, M_IP6OPT);
2515 		return (0);
2516 	}
2517 
2518 	/*  set options specified by user. */
2519 	NET_EPOCH_ENTER(et);
2520 	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2521 	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2522 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2523 		free(opt, M_IP6OPT);
2524 		NET_EPOCH_EXIT(et);
2525 		return (error);
2526 	}
2527 	NET_EPOCH_EXIT(et);
2528 	*pktopt = opt;
2529 	return (0);
2530 }
2531 
2532 /*
2533  * initialize ip6_pktopts.  beware that there are non-zero default values in
2534  * the struct.
2535  */
2536 void
2537 ip6_initpktopts(struct ip6_pktopts *opt)
2538 {
2539 
2540 	bzero(opt, sizeof(*opt));
2541 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2542 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2543 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2544 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2545 }
2546 
2547 static int
2548 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2549     struct ucred *cred, int uproto)
2550 {
2551 	struct epoch_tracker et;
2552 	struct ip6_pktopts *opt;
2553 	int ret;
2554 
2555 	if (*pktopt == NULL) {
2556 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2557 		    M_NOWAIT);
2558 		if (*pktopt == NULL)
2559 			return (ENOBUFS);
2560 		ip6_initpktopts(*pktopt);
2561 	}
2562 	opt = *pktopt;
2563 
2564 	NET_EPOCH_ENTER(et);
2565 	ret = ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto);
2566 	NET_EPOCH_EXIT(et);
2567 
2568 	return (ret);
2569 }
2570 
2571 #define GET_PKTOPT_VAR(field, lenexpr) do {					\
2572 	if (pktopt && pktopt->field) {						\
2573 		INP_RUNLOCK(inp);						\
2574 		optdata = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK);		\
2575 		malloc_optdata = true;						\
2576 		INP_RLOCK(inp);							\
2577 		if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {		\
2578 			INP_RUNLOCK(inp);					\
2579 			free(optdata, M_TEMP);					\
2580 			return (ECONNRESET);					\
2581 		}								\
2582 		pktopt = inp->in6p_outputopts;					\
2583 		if (pktopt && pktopt->field) {					\
2584 			optdatalen = min(lenexpr, sopt->sopt_valsize);		\
2585 			bcopy(pktopt->field, optdata, optdatalen);		\
2586 		} else {							\
2587 			free(optdata, M_TEMP);					\
2588 			optdata = NULL;						\
2589 			malloc_optdata = false;					\
2590 		}								\
2591 	}									\
2592 } while(0)
2593 
2594 #define GET_PKTOPT_EXT_HDR(field) GET_PKTOPT_VAR(field,				\
2595 	(((struct ip6_ext *)pktopt->field)->ip6e_len + 1) << 3)
2596 
2597 #define GET_PKTOPT_SOCKADDR(field) GET_PKTOPT_VAR(field,			\
2598 	pktopt->field->sa_len)
2599 
2600 static int
2601 ip6_getpcbopt(struct inpcb *inp, int optname, struct sockopt *sopt)
2602 {
2603 	void *optdata = NULL;
2604 	bool malloc_optdata = false;
2605 	int optdatalen = 0;
2606 	int error = 0;
2607 	struct in6_pktinfo null_pktinfo;
2608 	int deftclass = 0, on;
2609 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2610 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2611 	struct ip6_pktopts *pktopt;
2612 
2613 	INP_RLOCK(inp);
2614 	pktopt = inp->in6p_outputopts;
2615 
2616 	switch (optname) {
2617 	case IPV6_PKTINFO:
2618 		optdata = (void *)&null_pktinfo;
2619 		if (pktopt && pktopt->ip6po_pktinfo) {
2620 			bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2621 			    sizeof(null_pktinfo));
2622 			in6_clearscope(&null_pktinfo.ipi6_addr);
2623 		} else {
2624 			/* XXX: we don't have to do this every time... */
2625 			bzero(&null_pktinfo, sizeof(null_pktinfo));
2626 		}
2627 		optdatalen = sizeof(struct in6_pktinfo);
2628 		break;
2629 	case IPV6_TCLASS:
2630 		if (pktopt && pktopt->ip6po_tclass >= 0)
2631 			deftclass = pktopt->ip6po_tclass;
2632 		optdata = (void *)&deftclass;
2633 		optdatalen = sizeof(int);
2634 		break;
2635 	case IPV6_HOPOPTS:
2636 		GET_PKTOPT_EXT_HDR(ip6po_hbh);
2637 		break;
2638 	case IPV6_RTHDR:
2639 		GET_PKTOPT_EXT_HDR(ip6po_rthdr);
2640 		break;
2641 	case IPV6_RTHDRDSTOPTS:
2642 		GET_PKTOPT_EXT_HDR(ip6po_dest1);
2643 		break;
2644 	case IPV6_DSTOPTS:
2645 		GET_PKTOPT_EXT_HDR(ip6po_dest2);
2646 		break;
2647 	case IPV6_NEXTHOP:
2648 		GET_PKTOPT_SOCKADDR(ip6po_nexthop);
2649 		break;
2650 	case IPV6_USE_MIN_MTU:
2651 		if (pktopt)
2652 			defminmtu = pktopt->ip6po_minmtu;
2653 		optdata = (void *)&defminmtu;
2654 		optdatalen = sizeof(int);
2655 		break;
2656 	case IPV6_DONTFRAG:
2657 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2658 			on = 1;
2659 		else
2660 			on = 0;
2661 		optdata = (void *)&on;
2662 		optdatalen = sizeof(on);
2663 		break;
2664 	case IPV6_PREFER_TEMPADDR:
2665 		if (pktopt)
2666 			defpreftemp = pktopt->ip6po_prefer_tempaddr;
2667 		optdata = (void *)&defpreftemp;
2668 		optdatalen = sizeof(int);
2669 		break;
2670 	default:		/* should not happen */
2671 #ifdef DIAGNOSTIC
2672 		panic("ip6_getpcbopt: unexpected option\n");
2673 #endif
2674 		INP_RUNLOCK(inp);
2675 		return (ENOPROTOOPT);
2676 	}
2677 	INP_RUNLOCK(inp);
2678 
2679 	error = sooptcopyout(sopt, optdata, optdatalen);
2680 	if (malloc_optdata)
2681 		free(optdata, M_TEMP);
2682 
2683 	return (error);
2684 }
2685 
2686 void
2687 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2688 {
2689 	if (pktopt == NULL)
2690 		return;
2691 
2692 	if (optname == -1 || optname == IPV6_PKTINFO) {
2693 		if (pktopt->ip6po_pktinfo)
2694 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2695 		pktopt->ip6po_pktinfo = NULL;
2696 	}
2697 	if (optname == -1 || optname == IPV6_HOPLIMIT)
2698 		pktopt->ip6po_hlim = -1;
2699 	if (optname == -1 || optname == IPV6_TCLASS)
2700 		pktopt->ip6po_tclass = -1;
2701 	if (optname == -1 || optname == IPV6_NEXTHOP) {
2702 		if (pktopt->ip6po_nextroute.ro_nh) {
2703 			NH_FREE(pktopt->ip6po_nextroute.ro_nh);
2704 			pktopt->ip6po_nextroute.ro_nh = NULL;
2705 		}
2706 		if (pktopt->ip6po_nexthop)
2707 			free(pktopt->ip6po_nexthop, M_IP6OPT);
2708 		pktopt->ip6po_nexthop = NULL;
2709 	}
2710 	if (optname == -1 || optname == IPV6_HOPOPTS) {
2711 		if (pktopt->ip6po_hbh)
2712 			free(pktopt->ip6po_hbh, M_IP6OPT);
2713 		pktopt->ip6po_hbh = NULL;
2714 	}
2715 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2716 		if (pktopt->ip6po_dest1)
2717 			free(pktopt->ip6po_dest1, M_IP6OPT);
2718 		pktopt->ip6po_dest1 = NULL;
2719 	}
2720 	if (optname == -1 || optname == IPV6_RTHDR) {
2721 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2722 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2723 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2724 		if (pktopt->ip6po_route.ro_nh) {
2725 			NH_FREE(pktopt->ip6po_route.ro_nh);
2726 			pktopt->ip6po_route.ro_nh = NULL;
2727 		}
2728 	}
2729 	if (optname == -1 || optname == IPV6_DSTOPTS) {
2730 		if (pktopt->ip6po_dest2)
2731 			free(pktopt->ip6po_dest2, M_IP6OPT);
2732 		pktopt->ip6po_dest2 = NULL;
2733 	}
2734 }
2735 
2736 #define PKTOPT_EXTHDRCPY(type) \
2737 do {\
2738 	if (src->type) {\
2739 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2740 		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2741 		if (dst->type == NULL)\
2742 			goto bad;\
2743 		bcopy(src->type, dst->type, hlen);\
2744 	}\
2745 } while (/*CONSTCOND*/ 0)
2746 
2747 static int
2748 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2749 {
2750 	if (dst == NULL || src == NULL)  {
2751 		printf("ip6_clearpktopts: invalid argument\n");
2752 		return (EINVAL);
2753 	}
2754 
2755 	dst->ip6po_hlim = src->ip6po_hlim;
2756 	dst->ip6po_tclass = src->ip6po_tclass;
2757 	dst->ip6po_flags = src->ip6po_flags;
2758 	dst->ip6po_minmtu = src->ip6po_minmtu;
2759 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2760 	if (src->ip6po_pktinfo) {
2761 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2762 		    M_IP6OPT, canwait);
2763 		if (dst->ip6po_pktinfo == NULL)
2764 			goto bad;
2765 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2766 	}
2767 	if (src->ip6po_nexthop) {
2768 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2769 		    M_IP6OPT, canwait);
2770 		if (dst->ip6po_nexthop == NULL)
2771 			goto bad;
2772 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2773 		    src->ip6po_nexthop->sa_len);
2774 	}
2775 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2776 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2777 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2778 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2779 	return (0);
2780 
2781   bad:
2782 	ip6_clearpktopts(dst, -1);
2783 	return (ENOBUFS);
2784 }
2785 #undef PKTOPT_EXTHDRCPY
2786 
2787 struct ip6_pktopts *
2788 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2789 {
2790 	int error;
2791 	struct ip6_pktopts *dst;
2792 
2793 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2794 	if (dst == NULL)
2795 		return (NULL);
2796 	ip6_initpktopts(dst);
2797 
2798 	if ((error = copypktopts(dst, src, canwait)) != 0) {
2799 		free(dst, M_IP6OPT);
2800 		return (NULL);
2801 	}
2802 
2803 	return (dst);
2804 }
2805 
2806 void
2807 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2808 {
2809 	if (pktopt == NULL)
2810 		return;
2811 
2812 	ip6_clearpktopts(pktopt, -1);
2813 
2814 	free(pktopt, M_IP6OPT);
2815 }
2816 
2817 /*
2818  * Set IPv6 outgoing packet options based on advanced API.
2819  */
2820 int
2821 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2822     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2823 {
2824 	struct cmsghdr *cm = NULL;
2825 
2826 	if (control == NULL || opt == NULL)
2827 		return (EINVAL);
2828 
2829 	/*
2830 	 * ip6_setpktopt can call ifnet_byindex(), so it's imperative that we
2831 	 * are in the network epoch here.
2832 	 */
2833 	NET_EPOCH_ASSERT();
2834 
2835 	ip6_initpktopts(opt);
2836 	if (stickyopt) {
2837 		int error;
2838 
2839 		/*
2840 		 * If stickyopt is provided, make a local copy of the options
2841 		 * for this particular packet, then override them by ancillary
2842 		 * objects.
2843 		 * XXX: copypktopts() does not copy the cached route to a next
2844 		 * hop (if any).  This is not very good in terms of efficiency,
2845 		 * but we can allow this since this option should be rarely
2846 		 * used.
2847 		 */
2848 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2849 			return (error);
2850 	}
2851 
2852 	/*
2853 	 * XXX: Currently, we assume all the optional information is stored
2854 	 * in a single mbuf.
2855 	 */
2856 	if (control->m_next)
2857 		return (EINVAL);
2858 
2859 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2860 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2861 		int error;
2862 
2863 		if (control->m_len < CMSG_LEN(0))
2864 			return (EINVAL);
2865 
2866 		cm = mtod(control, struct cmsghdr *);
2867 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2868 			return (EINVAL);
2869 		if (cm->cmsg_level != IPPROTO_IPV6)
2870 			continue;
2871 
2872 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2873 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2874 		if (error)
2875 			return (error);
2876 	}
2877 
2878 	return (0);
2879 }
2880 
2881 /*
2882  * Set a particular packet option, as a sticky option or an ancillary data
2883  * item.  "len" can be 0 only when it's a sticky option.
2884  * We have 4 cases of combination of "sticky" and "cmsg":
2885  * "sticky=0, cmsg=0": impossible
2886  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2887  * "sticky=1, cmsg=0": RFC3542 socket option
2888  * "sticky=1, cmsg=1": RFC2292 socket option
2889  */
2890 static int
2891 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2892     struct ucred *cred, int sticky, int cmsg, int uproto)
2893 {
2894 	int minmtupolicy, preftemp;
2895 	int error;
2896 
2897 	NET_EPOCH_ASSERT();
2898 
2899 	if (!sticky && !cmsg) {
2900 #ifdef DIAGNOSTIC
2901 		printf("ip6_setpktopt: impossible case\n");
2902 #endif
2903 		return (EINVAL);
2904 	}
2905 
2906 	/*
2907 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2908 	 * not be specified in the context of RFC3542.  Conversely,
2909 	 * RFC3542 types should not be specified in the context of RFC2292.
2910 	 */
2911 	if (!cmsg) {
2912 		switch (optname) {
2913 		case IPV6_2292PKTINFO:
2914 		case IPV6_2292HOPLIMIT:
2915 		case IPV6_2292NEXTHOP:
2916 		case IPV6_2292HOPOPTS:
2917 		case IPV6_2292DSTOPTS:
2918 		case IPV6_2292RTHDR:
2919 		case IPV6_2292PKTOPTIONS:
2920 			return (ENOPROTOOPT);
2921 		}
2922 	}
2923 	if (sticky && cmsg) {
2924 		switch (optname) {
2925 		case IPV6_PKTINFO:
2926 		case IPV6_HOPLIMIT:
2927 		case IPV6_NEXTHOP:
2928 		case IPV6_HOPOPTS:
2929 		case IPV6_DSTOPTS:
2930 		case IPV6_RTHDRDSTOPTS:
2931 		case IPV6_RTHDR:
2932 		case IPV6_USE_MIN_MTU:
2933 		case IPV6_DONTFRAG:
2934 		case IPV6_TCLASS:
2935 		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2936 			return (ENOPROTOOPT);
2937 		}
2938 	}
2939 
2940 	switch (optname) {
2941 	case IPV6_2292PKTINFO:
2942 	case IPV6_PKTINFO:
2943 	{
2944 		struct ifnet *ifp = NULL;
2945 		struct in6_pktinfo *pktinfo;
2946 
2947 		if (len != sizeof(struct in6_pktinfo))
2948 			return (EINVAL);
2949 
2950 		pktinfo = (struct in6_pktinfo *)buf;
2951 
2952 		/*
2953 		 * An application can clear any sticky IPV6_PKTINFO option by
2954 		 * doing a "regular" setsockopt with ipi6_addr being
2955 		 * in6addr_any and ipi6_ifindex being zero.
2956 		 * [RFC 3542, Section 6]
2957 		 */
2958 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2959 		    pktinfo->ipi6_ifindex == 0 &&
2960 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2961 			ip6_clearpktopts(opt, optname);
2962 			break;
2963 		}
2964 
2965 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2966 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2967 			return (EINVAL);
2968 		}
2969 		if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2970 			return (EINVAL);
2971 		/* validate the interface index if specified. */
2972 		if (pktinfo->ipi6_ifindex) {
2973 			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2974 			if (ifp == NULL)
2975 				return (ENXIO);
2976 		}
2977 		if (ifp != NULL && (ifp->if_afdata[AF_INET6] == NULL ||
2978 		    (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0))
2979 			return (ENETDOWN);
2980 
2981 		if (ifp != NULL &&
2982 		    !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2983 			struct in6_ifaddr *ia;
2984 
2985 			in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2986 			ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2987 			if (ia == NULL)
2988 				return (EADDRNOTAVAIL);
2989 			ifa_free(&ia->ia_ifa);
2990 		}
2991 		/*
2992 		 * We store the address anyway, and let in6_selectsrc()
2993 		 * validate the specified address.  This is because ipi6_addr
2994 		 * may not have enough information about its scope zone, and
2995 		 * we may need additional information (such as outgoing
2996 		 * interface or the scope zone of a destination address) to
2997 		 * disambiguate the scope.
2998 		 * XXX: the delay of the validation may confuse the
2999 		 * application when it is used as a sticky option.
3000 		 */
3001 		if (opt->ip6po_pktinfo == NULL) {
3002 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
3003 			    M_IP6OPT, M_NOWAIT);
3004 			if (opt->ip6po_pktinfo == NULL)
3005 				return (ENOBUFS);
3006 		}
3007 		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
3008 		break;
3009 	}
3010 
3011 	case IPV6_2292HOPLIMIT:
3012 	case IPV6_HOPLIMIT:
3013 	{
3014 		int *hlimp;
3015 
3016 		/*
3017 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
3018 		 * to simplify the ordering among hoplimit options.
3019 		 */
3020 		if (optname == IPV6_HOPLIMIT && sticky)
3021 			return (ENOPROTOOPT);
3022 
3023 		if (len != sizeof(int))
3024 			return (EINVAL);
3025 		hlimp = (int *)buf;
3026 		if (*hlimp < -1 || *hlimp > 255)
3027 			return (EINVAL);
3028 
3029 		opt->ip6po_hlim = *hlimp;
3030 		break;
3031 	}
3032 
3033 	case IPV6_TCLASS:
3034 	{
3035 		int tclass;
3036 
3037 		if (len != sizeof(int))
3038 			return (EINVAL);
3039 		tclass = *(int *)buf;
3040 		if (tclass < -1 || tclass > 255)
3041 			return (EINVAL);
3042 
3043 		opt->ip6po_tclass = tclass;
3044 		break;
3045 	}
3046 
3047 	case IPV6_2292NEXTHOP:
3048 	case IPV6_NEXTHOP:
3049 		if (cred != NULL) {
3050 			error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
3051 			if (error)
3052 				return (error);
3053 		}
3054 
3055 		if (len == 0) {	/* just remove the option */
3056 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
3057 			break;
3058 		}
3059 
3060 		/* check if cmsg_len is large enough for sa_len */
3061 		if (len < sizeof(struct sockaddr) || len < *buf)
3062 			return (EINVAL);
3063 
3064 		switch (((struct sockaddr *)buf)->sa_family) {
3065 		case AF_INET6:
3066 		{
3067 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
3068 			int error;
3069 
3070 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
3071 				return (EINVAL);
3072 
3073 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
3074 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
3075 				return (EINVAL);
3076 			}
3077 			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
3078 			    != 0) {
3079 				return (error);
3080 			}
3081 			break;
3082 		}
3083 		case AF_LINK:	/* should eventually be supported */
3084 		default:
3085 			return (EAFNOSUPPORT);
3086 		}
3087 
3088 		/* turn off the previous option, then set the new option. */
3089 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
3090 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
3091 		if (opt->ip6po_nexthop == NULL)
3092 			return (ENOBUFS);
3093 		bcopy(buf, opt->ip6po_nexthop, *buf);
3094 		break;
3095 
3096 	case IPV6_2292HOPOPTS:
3097 	case IPV6_HOPOPTS:
3098 	{
3099 		struct ip6_hbh *hbh;
3100 		int hbhlen;
3101 
3102 		/*
3103 		 * XXX: We don't allow a non-privileged user to set ANY HbH
3104 		 * options, since per-option restriction has too much
3105 		 * overhead.
3106 		 */
3107 		if (cred != NULL) {
3108 			error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
3109 			if (error)
3110 				return (error);
3111 		}
3112 
3113 		if (len == 0) {
3114 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
3115 			break;	/* just remove the option */
3116 		}
3117 
3118 		/* message length validation */
3119 		if (len < sizeof(struct ip6_hbh))
3120 			return (EINVAL);
3121 		hbh = (struct ip6_hbh *)buf;
3122 		hbhlen = (hbh->ip6h_len + 1) << 3;
3123 		if (len != hbhlen)
3124 			return (EINVAL);
3125 
3126 		/* turn off the previous option, then set the new option. */
3127 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
3128 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
3129 		if (opt->ip6po_hbh == NULL)
3130 			return (ENOBUFS);
3131 		bcopy(hbh, opt->ip6po_hbh, hbhlen);
3132 
3133 		break;
3134 	}
3135 
3136 	case IPV6_2292DSTOPTS:
3137 	case IPV6_DSTOPTS:
3138 	case IPV6_RTHDRDSTOPTS:
3139 	{
3140 		struct ip6_dest *dest, **newdest = NULL;
3141 		int destlen;
3142 
3143 		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
3144 			error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
3145 			if (error)
3146 				return (error);
3147 		}
3148 
3149 		if (len == 0) {
3150 			ip6_clearpktopts(opt, optname);
3151 			break;	/* just remove the option */
3152 		}
3153 
3154 		/* message length validation */
3155 		if (len < sizeof(struct ip6_dest))
3156 			return (EINVAL);
3157 		dest = (struct ip6_dest *)buf;
3158 		destlen = (dest->ip6d_len + 1) << 3;
3159 		if (len != destlen)
3160 			return (EINVAL);
3161 
3162 		/*
3163 		 * Determine the position that the destination options header
3164 		 * should be inserted; before or after the routing header.
3165 		 */
3166 		switch (optname) {
3167 		case IPV6_2292DSTOPTS:
3168 			/*
3169 			 * The old advacned API is ambiguous on this point.
3170 			 * Our approach is to determine the position based
3171 			 * according to the existence of a routing header.
3172 			 * Note, however, that this depends on the order of the
3173 			 * extension headers in the ancillary data; the 1st
3174 			 * part of the destination options header must appear
3175 			 * before the routing header in the ancillary data,
3176 			 * too.
3177 			 * RFC3542 solved the ambiguity by introducing
3178 			 * separate ancillary data or option types.
3179 			 */
3180 			if (opt->ip6po_rthdr == NULL)
3181 				newdest = &opt->ip6po_dest1;
3182 			else
3183 				newdest = &opt->ip6po_dest2;
3184 			break;
3185 		case IPV6_RTHDRDSTOPTS:
3186 			newdest = &opt->ip6po_dest1;
3187 			break;
3188 		case IPV6_DSTOPTS:
3189 			newdest = &opt->ip6po_dest2;
3190 			break;
3191 		}
3192 
3193 		/* turn off the previous option, then set the new option. */
3194 		ip6_clearpktopts(opt, optname);
3195 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
3196 		if (*newdest == NULL)
3197 			return (ENOBUFS);
3198 		bcopy(dest, *newdest, destlen);
3199 
3200 		break;
3201 	}
3202 
3203 	case IPV6_2292RTHDR:
3204 	case IPV6_RTHDR:
3205 	{
3206 		struct ip6_rthdr *rth;
3207 		int rthlen;
3208 
3209 		if (len == 0) {
3210 			ip6_clearpktopts(opt, IPV6_RTHDR);
3211 			break;	/* just remove the option */
3212 		}
3213 
3214 		/* message length validation */
3215 		if (len < sizeof(struct ip6_rthdr))
3216 			return (EINVAL);
3217 		rth = (struct ip6_rthdr *)buf;
3218 		rthlen = (rth->ip6r_len + 1) << 3;
3219 		if (len != rthlen)
3220 			return (EINVAL);
3221 
3222 		switch (rth->ip6r_type) {
3223 		case IPV6_RTHDR_TYPE_0:
3224 			if (rth->ip6r_len == 0)	/* must contain one addr */
3225 				return (EINVAL);
3226 			if (rth->ip6r_len % 2) /* length must be even */
3227 				return (EINVAL);
3228 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
3229 				return (EINVAL);
3230 			break;
3231 		default:
3232 			return (EINVAL);	/* not supported */
3233 		}
3234 
3235 		/* turn off the previous option */
3236 		ip6_clearpktopts(opt, IPV6_RTHDR);
3237 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
3238 		if (opt->ip6po_rthdr == NULL)
3239 			return (ENOBUFS);
3240 		bcopy(rth, opt->ip6po_rthdr, rthlen);
3241 
3242 		break;
3243 	}
3244 
3245 	case IPV6_USE_MIN_MTU:
3246 		if (len != sizeof(int))
3247 			return (EINVAL);
3248 		minmtupolicy = *(int *)buf;
3249 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3250 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
3251 		    minmtupolicy != IP6PO_MINMTU_ALL) {
3252 			return (EINVAL);
3253 		}
3254 		opt->ip6po_minmtu = minmtupolicy;
3255 		break;
3256 
3257 	case IPV6_DONTFRAG:
3258 		if (len != sizeof(int))
3259 			return (EINVAL);
3260 
3261 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3262 			/*
3263 			 * we ignore this option for TCP sockets.
3264 			 * (RFC3542 leaves this case unspecified.)
3265 			 */
3266 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3267 		} else
3268 			opt->ip6po_flags |= IP6PO_DONTFRAG;
3269 		break;
3270 
3271 	case IPV6_PREFER_TEMPADDR:
3272 		if (len != sizeof(int))
3273 			return (EINVAL);
3274 		preftemp = *(int *)buf;
3275 		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3276 		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3277 		    preftemp != IP6PO_TEMPADDR_PREFER) {
3278 			return (EINVAL);
3279 		}
3280 		opt->ip6po_prefer_tempaddr = preftemp;
3281 		break;
3282 
3283 	default:
3284 		return (ENOPROTOOPT);
3285 	} /* end of switch */
3286 
3287 	return (0);
3288 }
3289 
3290 /*
3291  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3292  * packet to the input queue of a specified interface.  Note that this
3293  * calls the output routine of the loopback "driver", but with an interface
3294  * pointer that might NOT be &loif -- easier than replicating that code here.
3295  */
3296 void
3297 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
3298 {
3299 	struct mbuf *copym;
3300 	struct ip6_hdr *ip6;
3301 
3302 	copym = m_copym(m, 0, M_COPYALL, M_NOWAIT);
3303 	if (copym == NULL)
3304 		return;
3305 
3306 	/*
3307 	 * Make sure to deep-copy IPv6 header portion in case the data
3308 	 * is in an mbuf cluster, so that we can safely override the IPv6
3309 	 * header portion later.
3310 	 */
3311 	if (!M_WRITABLE(copym) ||
3312 	    copym->m_len < sizeof(struct ip6_hdr)) {
3313 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
3314 		if (copym == NULL)
3315 			return;
3316 	}
3317 	ip6 = mtod(copym, struct ip6_hdr *);
3318 	/*
3319 	 * clear embedded scope identifiers if necessary.
3320 	 * in6_clearscope will touch the addresses only when necessary.
3321 	 */
3322 	in6_clearscope(&ip6->ip6_src);
3323 	in6_clearscope(&ip6->ip6_dst);
3324 	if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3325 		copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3326 		    CSUM_PSEUDO_HDR;
3327 		copym->m_pkthdr.csum_data = 0xffff;
3328 	}
3329 	if_simloop(ifp, copym, AF_INET6, 0);
3330 }
3331 
3332 /*
3333  * Chop IPv6 header off from the payload.
3334  */
3335 static int
3336 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3337 {
3338 	struct mbuf *mh;
3339 	struct ip6_hdr *ip6;
3340 
3341 	ip6 = mtod(m, struct ip6_hdr *);
3342 	if (m->m_len > sizeof(*ip6)) {
3343 		mh = m_gethdr(M_NOWAIT, MT_DATA);
3344 		if (mh == NULL) {
3345 			m_freem(m);
3346 			return ENOBUFS;
3347 		}
3348 		m_move_pkthdr(mh, m);
3349 		M_ALIGN(mh, sizeof(*ip6));
3350 		m->m_len -= sizeof(*ip6);
3351 		m->m_data += sizeof(*ip6);
3352 		mh->m_next = m;
3353 		m = mh;
3354 		m->m_len = sizeof(*ip6);
3355 		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3356 	}
3357 	exthdrs->ip6e_ip6 = m;
3358 	return 0;
3359 }
3360 
3361 /*
3362  * Compute IPv6 extension header length.
3363  */
3364 int
3365 ip6_optlen(struct inpcb *inp)
3366 {
3367 	int len;
3368 
3369 	if (!inp->in6p_outputopts)
3370 		return 0;
3371 
3372 	len = 0;
3373 #define elen(x) \
3374     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3375 
3376 	len += elen(inp->in6p_outputopts->ip6po_hbh);
3377 	if (inp->in6p_outputopts->ip6po_rthdr)
3378 		/* dest1 is valid with rthdr only */
3379 		len += elen(inp->in6p_outputopts->ip6po_dest1);
3380 	len += elen(inp->in6p_outputopts->ip6po_rthdr);
3381 	len += elen(inp->in6p_outputopts->ip6po_dest2);
3382 	return len;
3383 #undef elen
3384 }
3385