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_ratelimit.h"
71#include "opt_ipsec.h"
72#include "opt_sctp.h"
73#include "opt_route.h"
74#include "opt_rss.h"
75
76#include <sys/param.h>
77#include <sys/kernel.h>
78#include <sys/malloc.h>
79#include <sys/mbuf.h>
80#include <sys/errno.h>
81#include <sys/priv.h>
82#include <sys/proc.h>
83#include <sys/protosw.h>
84#include <sys/socket.h>
85#include <sys/socketvar.h>
86#include <sys/syslog.h>
87#include <sys/ucred.h>
88
89#include <machine/in_cksum.h>
90
91#include <net/if.h>
92#include <net/if_var.h>
93#include <net/if_vlan_var.h>
94#include <net/if_llatbl.h>
95#include <net/ethernet.h>
96#include <net/netisr.h>
97#include <net/route.h>
98#include <net/pfil.h>
99#include <net/rss_config.h>
100#include <net/vnet.h>
101
102#include <netinet/in.h>
103#include <netinet/in_var.h>
104#include <netinet/ip_var.h>
105#include <netinet6/in6_fib.h>
106#include <netinet6/in6_var.h>
107#include <netinet/ip6.h>
108#include <netinet/icmp6.h>
109#include <netinet6/ip6_var.h>
110#include <netinet/in_pcb.h>
111#include <netinet/tcp_var.h>
112#include <netinet6/nd6.h>
113#include <netinet6/in6_rss.h>
114
115#include <netipsec/ipsec_support.h>
116#if defined(SCTP) || defined(SCTP_SUPPORT)
117#include <netinet/sctp.h>
118#include <netinet/sctp_crc32.h>
119#endif
120
121#include <netinet6/ip6protosw.h>
122#include <netinet6/scope6_var.h>
123
124extern int in6_mcast_loop;
125
126struct ip6_exthdrs {
127	struct mbuf *ip6e_ip6;
128	struct mbuf *ip6e_hbh;
129	struct mbuf *ip6e_dest1;
130	struct mbuf *ip6e_rthdr;
131	struct mbuf *ip6e_dest2;
132};
133
134static MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
135
136static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
137			   struct ucred *, int);
138static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
139	struct socket *, struct sockopt *);
140static int ip6_getpcbopt(struct inpcb *, int, struct sockopt *);
141static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
142	struct ucred *, int, int, int);
143
144static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
145static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
146	struct ip6_frag **);
147static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
148static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
149static int ip6_getpmtu(struct route_in6 *, int,
150	struct ifnet *, const struct in6_addr *, u_long *, int *, u_int,
151	u_int);
152static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
153	u_long *, int *, u_int);
154static int ip6_getpmtu_ctl(u_int, const struct in6_addr *, u_long *);
155static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
156
157
158/*
159 * Make an extension header from option data.  hp is the source,
160 * mp is the destination, and _ol is the optlen.
161 */
162#define	MAKE_EXTHDR(hp, mp, _ol)					\
163    do {								\
164	if (hp) {							\
165		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
166		error = ip6_copyexthdr((mp), (caddr_t)(hp),		\
167		    ((eh)->ip6e_len + 1) << 3);				\
168		if (error)						\
169			goto freehdrs;					\
170		(_ol) += (*(mp))->m_len;				\
171	}								\
172    } while (/*CONSTCOND*/ 0)
173
174/*
175 * Form a chain of extension headers.
176 * m is the extension header mbuf
177 * mp is the previous mbuf in the chain
178 * p is the next header
179 * i is the type of option.
180 */
181#define MAKE_CHAIN(m, mp, p, i)\
182    do {\
183	if (m) {\
184		if (!hdrsplit) \
185			panic("%s:%d: assumption failed: "\
186			    "hdr not split: hdrsplit %d exthdrs %p",\
187			    __func__, __LINE__, hdrsplit, &exthdrs);\
188		*mtod((m), u_char *) = *(p);\
189		*(p) = (i);\
190		p = mtod((m), u_char *);\
191		(m)->m_next = (mp)->m_next;\
192		(mp)->m_next = (m);\
193		(mp) = (m);\
194	}\
195    } while (/*CONSTCOND*/ 0)
196
197void
198in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
199{
200	u_short csum;
201
202	csum = in_cksum_skip(m, offset + plen, offset);
203	if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
204		csum = 0xffff;
205	offset += m->m_pkthdr.csum_data;	/* checksum offset */
206
207	if (offset + sizeof(csum) > m->m_len)
208		m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
209	else
210		*(u_short *)mtodo(m, offset) = csum;
211}
212
213static int
214ip6_output_delayed_csum(struct mbuf *m, struct ifnet *ifp, int csum_flags,
215    int plen, int optlen, bool frag __unused)
216{
217
218	KASSERT((plen >= optlen), ("%s:%d: plen %d < optlen %d, m %p, ifp %p "
219	    "csum_flags %#x frag %d\n",
220	    __func__, __LINE__, plen, optlen, m, ifp, csum_flags, frag));
221
222	if ((csum_flags & CSUM_DELAY_DATA_IPV6) ||
223#if defined(SCTP) || defined(SCTP_SUPPORT)
224	    (csum_flags & CSUM_SCTP_IPV6) ||
225#endif
226	    false) {
227		if (csum_flags & CSUM_DELAY_DATA_IPV6) {
228			in6_delayed_cksum(m, plen - optlen,
229			    sizeof(struct ip6_hdr) + optlen);
230			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
231		}
232#if defined(SCTP) || defined(SCTP_SUPPORT)
233		if (csum_flags & CSUM_SCTP_IPV6) {
234			sctp_delayed_cksum(m, sizeof(struct ip6_hdr) + optlen);
235			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
236		}
237#endif
238	}
239
240	return (0);
241}
242
243int
244ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
245    int fraglen , uint32_t id)
246{
247	struct mbuf *m, **mnext, *m_frgpart;
248	struct ip6_hdr *ip6, *mhip6;
249	struct ip6_frag *ip6f;
250	int off;
251	int error;
252	int tlen = m0->m_pkthdr.len;
253
254	KASSERT((fraglen % 8 == 0), ("Fragment length must be a multiple of 8"));
255
256	m = m0;
257	ip6 = mtod(m, struct ip6_hdr *);
258	mnext = &m->m_nextpkt;
259
260	for (off = hlen; off < tlen; off += fraglen) {
261		m = m_gethdr(M_NOWAIT, MT_DATA);
262		if (!m) {
263			IP6STAT_INC(ip6s_odropped);
264			return (ENOBUFS);
265		}
266
267		/*
268		 * Make sure the complete packet header gets copied
269		 * from the originating mbuf to the newly created
270		 * mbuf. This also ensures that existing firewall
271		 * classification(s), VLAN tags and so on get copied
272		 * to the resulting fragmented packet(s):
273		 */
274		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
275			m_free(m);
276			IP6STAT_INC(ip6s_odropped);
277			return (ENOBUFS);
278		}
279
280		*mnext = m;
281		mnext = &m->m_nextpkt;
282		m->m_data += max_linkhdr;
283		mhip6 = mtod(m, struct ip6_hdr *);
284		*mhip6 = *ip6;
285		m->m_len = sizeof(*mhip6);
286		error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
287		if (error) {
288			IP6STAT_INC(ip6s_odropped);
289			return (error);
290		}
291		ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
292		if (off + fraglen >= tlen)
293			fraglen = tlen - off;
294		else
295			ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
296		mhip6->ip6_plen = htons((u_short)(fraglen + hlen +
297		    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
298		if ((m_frgpart = m_copym(m0, off, fraglen, M_NOWAIT)) == NULL) {
299			IP6STAT_INC(ip6s_odropped);
300			return (ENOBUFS);
301		}
302		m_cat(m, m_frgpart);
303		m->m_pkthdr.len = fraglen + hlen + sizeof(*ip6f);
304		ip6f->ip6f_reserved = 0;
305		ip6f->ip6f_ident = id;
306		ip6f->ip6f_nxt = nextproto;
307		IP6STAT_INC(ip6s_ofragments);
308		in6_ifstat_inc(ifp, ifs6_out_fragcreat);
309	}
310
311	return (0);
312}
313
314/*
315 * IP6 output.
316 * The packet in mbuf chain m contains a skeletal IP6 header (with pri, len,
317 * nxt, hlim, src, dst).
318 * This function may modify ver and hlim only.
319 * The mbuf chain containing the packet will be freed.
320 * The mbuf opt, if present, will not be freed.
321 * If route_in6 ro is present and has ro_rt initialized, route lookup would be
322 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
323 * then result of route lookup is stored in ro->ro_rt.
324 *
325 * Type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and nd_ifinfo.linkmtu
326 * is uint32_t.  So we use u_long to hold largest one, which is rt_mtu.
327 *
328 * ifpp - XXX: just for statistics
329 */
330/*
331 * XXX TODO: no flowid is assigned for outbound flows?
332 */
333int
334ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
335    struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
336    struct ifnet **ifpp, struct inpcb *inp)
337{
338	struct ip6_hdr *ip6;
339	struct ifnet *ifp, *origifp;
340	struct mbuf *m = m0;
341	struct mbuf *mprev;
342	int tlen, len;
343	struct route_in6 ip6route;
344	struct rtentry *rt = NULL;
345	struct sockaddr_in6 *dst, src_sa, dst_sa;
346	struct in6_addr odst;
347	u_char *nexthdrp;
348	int error = 0;
349	int vlan_pcp = -1;
350	struct in6_ifaddr *ia = NULL;
351	u_long mtu;
352	int alwaysfrag, dontfrag;
353	u_int32_t optlen, plen = 0, unfragpartlen;
354	struct ip6_exthdrs exthdrs;
355	struct in6_addr src0, dst0;
356	u_int32_t zone;
357	struct route_in6 *ro_pmtu = NULL;
358	bool hdrsplit;
359	int sw_csum, tso;
360	int needfiblookup;
361	uint32_t fibnum;
362	struct m_tag *fwd_tag = NULL;
363	uint32_t id;
364
365	if (inp != NULL) {
366		INP_LOCK_ASSERT(inp);
367		M_SETFIB(m, inp->inp_inc.inc_fibnum);
368		if ((flags & IP_NODEFAULTFLOWID) == 0) {
369			/* Unconditionally set flowid. */
370			m->m_pkthdr.flowid = inp->inp_flowid;
371			M_HASHTYPE_SET(m, inp->inp_flowtype);
372		}
373		if ((inp->inp_flags2 & INP_2PCP_SET) != 0)
374			vlan_pcp = (inp->inp_flags2 & INP_2PCP_MASK) >>
375			    INP_2PCP_SHIFT;
376	}
377
378#if defined(IPSEC) || defined(IPSEC_SUPPORT)
379	/*
380	 * IPSec checking which handles several cases.
381	 * FAST IPSEC: We re-injected the packet.
382	 * XXX: need scope argument.
383	 */
384	if (IPSEC_ENABLED(ipv6)) {
385		if ((error = IPSEC_OUTPUT(ipv6, m, inp)) != 0) {
386			if (error == EINPROGRESS)
387				error = 0;
388			goto done;
389		}
390	}
391#endif /* IPSEC */
392
393	/* Source address validation. */
394	ip6 = mtod(m, struct ip6_hdr *);
395	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
396	    (flags & IPV6_UNSPECSRC) == 0) {
397		error = EOPNOTSUPP;
398		IP6STAT_INC(ip6s_badscope);
399		goto bad;
400	}
401	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
402		error = EOPNOTSUPP;
403		IP6STAT_INC(ip6s_badscope);
404		goto bad;
405	}
406
407	/*
408	 * If we are given packet options to add extension headers prepare them.
409	 * Calculate the total length of the extension header chain.
410	 * Keep the length of the unfragmentable part for fragmentation.
411	 */
412	bzero(&exthdrs, sizeof(exthdrs));
413	optlen = 0;
414	unfragpartlen = sizeof(struct ip6_hdr);
415	if (opt) {
416		/* Hop-by-Hop options header. */
417		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh, optlen);
418
419		/* Destination options header (1st part). */
420		if (opt->ip6po_rthdr) {
421#ifndef RTHDR_SUPPORT_IMPLEMENTED
422			/*
423			 * If there is a routing header, discard the packet
424			 * right away here. RH0/1 are obsolete and we do not
425			 * currently support RH2/3/4.
426			 * People trying to use RH253/254 may want to disable
427			 * this check.
428			 * The moment we do support any routing header (again)
429			 * this block should check the routing type more
430			 * selectively.
431			 */
432			error = EINVAL;
433			goto bad;
434#endif
435
436			/*
437			 * Destination options header (1st part).
438			 * This only makes sense with a routing header.
439			 * See Section 9.2 of RFC 3542.
440			 * Disabling this part just for MIP6 convenience is
441			 * a bad idea.  We need to think carefully about a
442			 * way to make the advanced API coexist with MIP6
443			 * options, which might automatically be inserted in
444			 * the kernel.
445			 */
446			MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1,
447			    optlen);
448		}
449		/* Routing header. */
450		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr, optlen);
451
452		unfragpartlen += optlen;
453
454		/*
455		 * NOTE: we don't add AH/ESP length here (done in
456		 * ip6_ipsec_output()).
457		 */
458
459		/* Destination options header (2nd part). */
460		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2, optlen);
461	}
462
463	/*
464	 * If there is at least one extension header,
465	 * separate IP6 header from the payload.
466	 */
467	hdrsplit = false;
468	if (optlen) {
469		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
470			m = NULL;
471			goto freehdrs;
472		}
473		m = exthdrs.ip6e_ip6;
474		ip6 = mtod(m, struct ip6_hdr *);
475		hdrsplit = true;
476	}
477
478	/* Adjust mbuf packet header length. */
479	m->m_pkthdr.len += optlen;
480	plen = m->m_pkthdr.len - sizeof(*ip6);
481
482	/* If this is a jumbo payload, insert a jumbo payload option. */
483	if (plen > IPV6_MAXPACKET) {
484		if (!hdrsplit) {
485			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
486				m = NULL;
487				goto freehdrs;
488			}
489			m = exthdrs.ip6e_ip6;
490			ip6 = mtod(m, struct ip6_hdr *);
491			hdrsplit = true;
492		}
493		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
494			goto freehdrs;
495		ip6->ip6_plen = 0;
496	} else
497		ip6->ip6_plen = htons(plen);
498	nexthdrp = &ip6->ip6_nxt;
499
500	if (optlen) {
501		/*
502		 * Concatenate headers and fill in next header fields.
503		 * Here we have, on "m"
504		 *	IPv6 payload
505		 * and we insert headers accordingly.
506		 * Finally, we should be getting:
507		 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload].
508		 *
509		 * During the header composing process "m" points to IPv6
510		 * header.  "mprev" points to an extension header prior to esp.
511		 */
512		mprev = m;
513
514		/*
515		 * We treat dest2 specially.  This makes IPsec processing
516		 * much easier.  The goal here is to make mprev point the
517		 * mbuf prior to dest2.
518		 *
519		 * Result: IPv6 dest2 payload.
520		 * m and mprev will point to IPv6 header.
521		 */
522		if (exthdrs.ip6e_dest2) {
523			if (!hdrsplit)
524				panic("%s:%d: assumption failed: "
525				    "hdr not split: hdrsplit %d exthdrs %p",
526				    __func__, __LINE__, hdrsplit, &exthdrs);
527			exthdrs.ip6e_dest2->m_next = m->m_next;
528			m->m_next = exthdrs.ip6e_dest2;
529			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
530			ip6->ip6_nxt = IPPROTO_DSTOPTS;
531		}
532
533		/*
534		 * Result: IPv6 hbh dest1 rthdr dest2 payload.
535		 * m will point to IPv6 header.  mprev will point to the
536		 * extension header prior to dest2 (rthdr in the above case).
537		 */
538		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
539		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
540			   IPPROTO_DSTOPTS);
541		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
542			   IPPROTO_ROUTING);
543	}
544
545	IP6STAT_INC(ip6s_localout);
546
547	/* Route packet. */
548	if (ro == NULL) {
549		ro = &ip6route;
550		bzero((caddr_t)ro, sizeof(*ro));
551	}
552	ro_pmtu = ro;
553	if (opt && opt->ip6po_rthdr)
554		ro = &opt->ip6po_route;
555	dst = (struct sockaddr_in6 *)&ro->ro_dst;
556	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
557again:
558	/*
559	 * If specified, try to fill in the traffic class field.
560	 * Do not override if a non-zero value is already set.
561	 * We check the diffserv field and the ECN field separately.
562	 */
563	if (opt && opt->ip6po_tclass >= 0) {
564		int mask = 0;
565
566		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
567			mask |= 0xfc;
568		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
569			mask |= 0x03;
570		if (mask != 0)
571			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
572	}
573
574	/* Fill in or override the hop limit field, if necessary. */
575	if (opt && opt->ip6po_hlim != -1)
576		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
577	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
578		if (im6o != NULL)
579			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
580		else
581			ip6->ip6_hlim = V_ip6_defmcasthlim;
582	}
583	/*
584	 * Validate route against routing table additions;
585	 * a better/more specific route might have been added.
586	 * Make sure that the address family is set in route.
587	 */
588	if (inp) {
589		ro->ro_dst.sin6_family = AF_INET6;
590		RT_VALIDATE((struct route *)ro, &inp->inp_rt_cookie, fibnum);
591	}
592	if (ro->ro_rt && fwd_tag == NULL && (ro->ro_rt->rt_flags & RTF_UP) &&
593	    ro->ro_dst.sin6_family == AF_INET6 &&
594	    IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)) {
595		rt = ro->ro_rt;
596		ifp = ro->ro_rt->rt_ifp;
597	} else {
598		if (ro->ro_lle)
599			LLE_FREE(ro->ro_lle);	/* zeros ro_lle */
600		ro->ro_lle = NULL;
601		if (fwd_tag == NULL) {
602			bzero(&dst_sa, sizeof(dst_sa));
603			dst_sa.sin6_family = AF_INET6;
604			dst_sa.sin6_len = sizeof(dst_sa);
605			dst_sa.sin6_addr = ip6->ip6_dst;
606		}
607		error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
608		    &rt, fibnum);
609		if (error != 0) {
610			if (ifp != NULL)
611				in6_ifstat_inc(ifp, ifs6_out_discard);
612			goto bad;
613		}
614	}
615	if (rt == NULL) {
616		/*
617		 * If in6_selectroute() does not return a route entry
618		 * dst may not have been updated.
619		 */
620		*dst = dst_sa;	/* XXX */
621	}
622
623	/* Then rt (for unicast) and ifp must be non-NULL valid values. */
624	if ((flags & IPV6_FORWARDING) == 0) {
625		/* XXX: the FORWARDING flag can be set for mrouting. */
626		in6_ifstat_inc(ifp, ifs6_out_request);
627	}
628	if (rt != NULL) {
629		ia = (struct in6_ifaddr *)(rt->rt_ifa);
630		counter_u64_add(rt->rt_pksent, 1);
631	}
632
633	/* Setup data structures for scope ID checks. */
634	src0 = ip6->ip6_src;
635	bzero(&src_sa, sizeof(src_sa));
636	src_sa.sin6_family = AF_INET6;
637	src_sa.sin6_len = sizeof(src_sa);
638	src_sa.sin6_addr = ip6->ip6_src;
639
640	dst0 = ip6->ip6_dst;
641	/* Re-initialize to be sure. */
642	bzero(&dst_sa, sizeof(dst_sa));
643	dst_sa.sin6_family = AF_INET6;
644	dst_sa.sin6_len = sizeof(dst_sa);
645	dst_sa.sin6_addr = ip6->ip6_dst;
646
647	/* Check for valid scope ID. */
648	if (in6_setscope(&src0, ifp, &zone) == 0 &&
649	    sa6_recoverscope(&src_sa) == 0 && zone == src_sa.sin6_scope_id &&
650	    in6_setscope(&dst0, ifp, &zone) == 0 &&
651	    sa6_recoverscope(&dst_sa) == 0 && zone == dst_sa.sin6_scope_id) {
652		/*
653		 * The outgoing interface is in the zone of the source
654		 * and destination addresses.
655		 *
656		 * Because the loopback interface cannot receive
657		 * packets with a different scope ID than its own,
658		 * there is a trick to pretend the outgoing packet
659		 * was received by the real network interface, by
660		 * setting "origifp" different from "ifp". This is
661		 * only allowed when "ifp" is a loopback network
662		 * interface. Refer to code in nd6_output_ifp() for
663		 * more details.
664		 */
665		origifp = ifp;
666
667		/*
668		 * We should use ia_ifp to support the case of sending
669		 * packets to an address of our own.
670		 */
671		if (ia != NULL && ia->ia_ifp)
672			ifp = ia->ia_ifp;
673
674	} else if ((ifp->if_flags & IFF_LOOPBACK) == 0 ||
675	    sa6_recoverscope(&src_sa) != 0 ||
676	    sa6_recoverscope(&dst_sa) != 0 ||
677	    dst_sa.sin6_scope_id == 0 ||
678	    (src_sa.sin6_scope_id != 0 &&
679	    src_sa.sin6_scope_id != dst_sa.sin6_scope_id) ||
680	    (origifp = ifnet_byindex(dst_sa.sin6_scope_id)) == NULL) {
681		/*
682		 * If the destination network interface is not a
683		 * loopback interface, or the destination network
684		 * address has no scope ID, or the source address has
685		 * a scope ID set which is different from the
686		 * destination address one, or there is no network
687		 * interface representing this scope ID, the address
688		 * pair is considered invalid.
689		 */
690		IP6STAT_INC(ip6s_badscope);
691		in6_ifstat_inc(ifp, ifs6_out_discard);
692		if (error == 0)
693			error = EHOSTUNREACH; /* XXX */
694		goto bad;
695	}
696	/* All scope ID checks are successful. */
697
698	if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
699		if (opt && opt->ip6po_nextroute.ro_rt) {
700			/*
701			 * The nexthop is explicitly specified by the
702			 * application.  We assume the next hop is an IPv6
703			 * address.
704			 */
705			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
706		}
707		else if ((rt->rt_flags & RTF_GATEWAY))
708			dst = (struct sockaddr_in6 *)rt->rt_gateway;
709	}
710
711	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
712		m->m_flags &= ~(M_BCAST | M_MCAST); /* Just in case. */
713	} else {
714		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
715		in6_ifstat_inc(ifp, ifs6_out_mcast);
716
717		/* Confirm that the outgoing interface supports multicast. */
718		if (!(ifp->if_flags & IFF_MULTICAST)) {
719			IP6STAT_INC(ip6s_noroute);
720			in6_ifstat_inc(ifp, ifs6_out_discard);
721			error = ENETUNREACH;
722			goto bad;
723		}
724		if ((im6o == NULL && in6_mcast_loop) ||
725		    (im6o && im6o->im6o_multicast_loop)) {
726			/*
727			 * Loop back multicast datagram if not expressly
728			 * forbidden to do so, even if we have not joined
729			 * the address; protocols will filter it later,
730			 * thus deferring a hash lookup and lock acquisition
731			 * at the expense of an m_copym().
732			 */
733			ip6_mloopback(ifp, m);
734		} else {
735			/*
736			 * If we are acting as a multicast router, perform
737			 * multicast forwarding as if the packet had just
738			 * arrived on the interface to which we are about
739			 * to send.  The multicast forwarding function
740			 * recursively calls this function, using the
741			 * IPV6_FORWARDING flag to prevent infinite recursion.
742			 *
743			 * Multicasts that are looped back by ip6_mloopback(),
744			 * above, will be forwarded by the ip6_input() routine,
745			 * if necessary.
746			 */
747			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
748				/*
749				 * XXX: ip6_mforward expects that rcvif is NULL
750				 * when it is called from the originating path.
751				 * However, it may not always be the case.
752				 */
753				m->m_pkthdr.rcvif = NULL;
754				if (ip6_mforward(ip6, ifp, m) != 0) {
755					m_freem(m);
756					goto done;
757				}
758			}
759		}
760		/*
761		 * Multicasts with a hoplimit of zero may be looped back,
762		 * above, but must not be transmitted on a network.
763		 * Also, multicasts addressed to the loopback interface
764		 * are not sent -- the above call to ip6_mloopback() will
765		 * loop back a copy if this host actually belongs to the
766		 * destination group on the loopback interface.
767		 */
768		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
769		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
770			m_freem(m);
771			goto done;
772		}
773	}
774
775	/*
776	 * Fill the outgoing inteface to tell the upper layer
777	 * to increment per-interface statistics.
778	 */
779	if (ifpp)
780		*ifpp = ifp;
781
782	/* Determine path MTU. */
783	if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &ip6->ip6_dst,
784		    &mtu, &alwaysfrag, fibnum, *nexthdrp)) != 0)
785		goto bad;
786
787	/*
788	 * The caller of this function may specify to use the minimum MTU
789	 * in some cases.
790	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
791	 * setting.  The logic is a bit complicated; by default, unicast
792	 * packets will follow path MTU while multicast packets will be sent at
793	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
794	 * including unicast ones will be sent at the minimum MTU.  Multicast
795	 * packets will always be sent at the minimum MTU unless
796	 * IP6PO_MINMTU_DISABLE is explicitly specified.
797	 * See RFC 3542 for more details.
798	 */
799	if (mtu > IPV6_MMTU) {
800		if ((flags & IPV6_MINMTU))
801			mtu = IPV6_MMTU;
802		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
803			mtu = IPV6_MMTU;
804		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
805			 (opt == NULL ||
806			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
807			mtu = IPV6_MMTU;
808		}
809	}
810
811	/*
812	 * Clear embedded scope identifiers if necessary.
813	 * in6_clearscope() will touch the addresses only when necessary.
814	 */
815	in6_clearscope(&ip6->ip6_src);
816	in6_clearscope(&ip6->ip6_dst);
817
818	/*
819	 * If the outgoing packet contains a hop-by-hop options header,
820	 * it must be examined and processed even by the source node.
821	 * (RFC 2460, section 4.)
822	 */
823	if (exthdrs.ip6e_hbh) {
824		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
825		u_int32_t dummy; /* XXX unused */
826		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
827
828#ifdef DIAGNOSTIC
829		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
830			panic("ip6e_hbh is not contiguous");
831#endif
832		/*
833		 *  XXX: if we have to send an ICMPv6 error to the sender,
834		 *       we need the M_LOOP flag since icmp6_error() expects
835		 *       the IPv6 and the hop-by-hop options header are
836		 *       contiguous unless the flag is set.
837		 */
838		m->m_flags |= M_LOOP;
839		m->m_pkthdr.rcvif = ifp;
840		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
841		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
842		    &dummy, &plen) < 0) {
843			/* m was already freed at this point. */
844			error = EINVAL;/* better error? */
845			goto done;
846		}
847		m->m_flags &= ~M_LOOP; /* XXX */
848		m->m_pkthdr.rcvif = NULL;
849	}
850
851	/* Jump over all PFIL processing if hooks are not active. */
852	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
853		goto passout;
854
855	odst = ip6->ip6_dst;
856	/* Run through list of hooks for output packets. */
857	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, 0, inp);
858	if (error != 0 || m == NULL)
859		goto done;
860	/* adjust pointer */
861	ip6 = mtod(m, struct ip6_hdr *);
862
863	needfiblookup = 0;
864	/* See if destination IP address was changed by packet filter. */
865	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
866		m->m_flags |= M_SKIP_FIREWALL;
867		/* If destination is now ourself drop to ip6_input(). */
868		if (in6_localip(&ip6->ip6_dst)) {
869			m->m_flags |= M_FASTFWD_OURS;
870			if (m->m_pkthdr.rcvif == NULL)
871				m->m_pkthdr.rcvif = V_loif;
872			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
873				m->m_pkthdr.csum_flags |=
874				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
875				m->m_pkthdr.csum_data = 0xffff;
876			}
877#if defined(SCTP) || defined(SCTP_SUPPORT)
878			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
879				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
880#endif
881			error = netisr_queue(NETISR_IPV6, m);
882			goto done;
883		} else {
884			RO_INVALIDATE_CACHE(ro);
885			needfiblookup = 1; /* Redo the routing table lookup. */
886		}
887	}
888	/* See if fib was changed by packet filter. */
889	if (fibnum != M_GETFIB(m)) {
890		m->m_flags |= M_SKIP_FIREWALL;
891		fibnum = M_GETFIB(m);
892		RO_INVALIDATE_CACHE(ro);
893		needfiblookup = 1;
894	}
895	if (needfiblookup)
896		goto again;
897
898	/* See if local, if yes, send it to netisr. */
899	if (m->m_flags & M_FASTFWD_OURS) {
900		if (m->m_pkthdr.rcvif == NULL)
901			m->m_pkthdr.rcvif = V_loif;
902		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
903			m->m_pkthdr.csum_flags |=
904			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
905			m->m_pkthdr.csum_data = 0xffff;
906		}
907#if defined(SCTP) || defined(SCTP_SUPPORT)
908		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
909			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
910#endif
911		error = netisr_queue(NETISR_IPV6, m);
912		goto done;
913	}
914	/* Or forward to some other address? */
915	if ((m->m_flags & M_IP6_NEXTHOP) &&
916	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
917		dst = (struct sockaddr_in6 *)&ro->ro_dst;
918		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
919		m->m_flags |= M_SKIP_FIREWALL;
920		m->m_flags &= ~M_IP6_NEXTHOP;
921		m_tag_delete(m, fwd_tag);
922		goto again;
923	}
924
925passout:
926	if (vlan_pcp > -1)
927		EVL_APPLY_PRI(m, vlan_pcp);
928	/*
929	 * Send the packet to the outgoing interface.
930	 * If necessary, do IPv6 fragmentation before sending.
931	 *
932	 * The logic here is rather complex:
933	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
934	 * 1-a:	send as is if tlen <= path mtu
935	 * 1-b:	fragment if tlen > path mtu
936	 *
937	 * 2: if user asks us not to fragment (dontfrag == 1)
938	 * 2-a:	send as is if tlen <= interface mtu
939	 * 2-b:	error if tlen > interface mtu
940	 *
941	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
942	 *	always fragment
943	 *
944	 * 4: if dontfrag == 1 && alwaysfrag == 1
945	 *	error, as we cannot handle this conflicting request.
946	 */
947	sw_csum = m->m_pkthdr.csum_flags;
948	if (!hdrsplit) {
949		tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
950		sw_csum &= ~ifp->if_hwassist;
951	} else
952		tso = 0;
953	/*
954	 * If we added extension headers, we will not do TSO and calculate the
955	 * checksums ourselves for now.
956	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
957	 * with ext. hdrs.
958	 */
959	error = ip6_output_delayed_csum(m, ifp, sw_csum, plen, optlen, false);
960	if (error != 0)
961		goto bad;
962	/* XXX-BZ m->m_pkthdr.csum_flags &= ~ifp->if_hwassist; */
963	tlen = m->m_pkthdr.len;
964
965	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
966		dontfrag = 1;
967	else
968		dontfrag = 0;
969	if (dontfrag && alwaysfrag) {	/* Case 4. */
970		/* Conflicting request - can't transmit. */
971		error = EMSGSIZE;
972		goto bad;
973	}
974	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* Case 2-b. */
975		/*
976		 * Even if the DONTFRAG option is specified, we cannot send the
977		 * packet when the data length is larger than the MTU of the
978		 * outgoing interface.
979		 * Notify the error by sending IPV6_PATHMTU ancillary data if
980		 * application wanted to know the MTU value. Also return an
981		 * error code (this is not described in the API spec).
982		 */
983		if (inp != NULL)
984			ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
985		error = EMSGSIZE;
986		goto bad;
987	}
988
989	/* Transmit packet without fragmentation. */
990	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* Cases 1-a and 2-a. */
991		struct in6_ifaddr *ia6;
992
993		ip6 = mtod(m, struct ip6_hdr *);
994		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
995		if (ia6) {
996			/* Record statistics for this interface address. */
997			counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
998			counter_u64_add(ia6->ia_ifa.ifa_obytes,
999			    m->m_pkthdr.len);
1000			ifa_free(&ia6->ia_ifa);
1001		}
1002#ifdef RATELIMIT
1003		if (inp != NULL) {
1004			if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
1005				in_pcboutput_txrtlmt(inp, ifp, m);
1006			/* stamp send tag on mbuf */
1007			m->m_pkthdr.snd_tag = inp->inp_snd_tag;
1008			m->m_pkthdr.csum_flags |= CSUM_SND_TAG;
1009		} else {
1010			m->m_pkthdr.snd_tag = NULL;
1011		}
1012#endif
1013		error = nd6_output_ifp(ifp, origifp, m, dst,
1014		    (struct route *)ro);
1015#ifdef RATELIMIT
1016		/* check for route change */
1017		if (error == EAGAIN)
1018			in_pcboutput_eagain(inp);
1019#endif
1020		goto done;
1021	}
1022
1023	/* Try to fragment the packet.  Cases 1-b and 3. */
1024	if (mtu < IPV6_MMTU) {
1025		/* Path MTU cannot be less than IPV6_MMTU. */
1026		error = EMSGSIZE;
1027		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1028		goto bad;
1029	} else if (ip6->ip6_plen == 0) {
1030		/* Jumbo payload cannot be fragmented. */
1031		error = EMSGSIZE;
1032		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1033		goto bad;
1034	} else {
1035		u_char nextproto;
1036
1037		/*
1038		 * Too large for the destination or interface;
1039		 * fragment if possible.
1040		 * Must be able to put at least 8 bytes per fragment.
1041		 */
1042		if (mtu > IPV6_MAXPACKET)
1043			mtu = IPV6_MAXPACKET;
1044
1045		len = (mtu - unfragpartlen - sizeof(struct ip6_frag)) & ~7;
1046		if (len < 8) {
1047			error = EMSGSIZE;
1048			in6_ifstat_inc(ifp, ifs6_out_fragfail);
1049			goto bad;
1050		}
1051
1052		/*
1053		 * If the interface will not calculate checksums on
1054		 * fragmented packets, then do it here.
1055		 * XXX-BZ handle the hw offloading case.  Need flags.
1056		 */
1057		error = ip6_output_delayed_csum(m, ifp, m->m_pkthdr.csum_flags,
1058		    plen, optlen, true);
1059		if (error != 0)
1060			goto bad;
1061
1062		/*
1063		 * Change the next header field of the last header in the
1064		 * unfragmentable part.
1065		 */
1066		if (exthdrs.ip6e_rthdr) {
1067			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1068			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1069		} else if (exthdrs.ip6e_dest1) {
1070			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1071			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1072		} else if (exthdrs.ip6e_hbh) {
1073			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1074			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1075		} else {
1076			ip6 = mtod(m, struct ip6_hdr *);
1077			nextproto = ip6->ip6_nxt;
1078			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1079		}
1080
1081		/*
1082		 * Loop through length of segment after first fragment,
1083		 * make new header and copy data of each part and link onto
1084		 * chain.
1085		 */
1086		m0 = m;
1087		id = htonl(ip6_randomid());
1088		error = ip6_fragment(ifp, m, unfragpartlen, nextproto,len, id);
1089		if (error != 0)
1090			goto sendorfree;
1091
1092		in6_ifstat_inc(ifp, ifs6_out_fragok);
1093	}
1094
1095	/* Remove leading garbage. */
1096sendorfree:
1097	m = m0->m_nextpkt;
1098	m0->m_nextpkt = 0;
1099	m_freem(m0);
1100	for (; m; m = m0) {
1101		m0 = m->m_nextpkt;
1102		m->m_nextpkt = 0;
1103		if (error == 0) {
1104			/* Record statistics for this interface address. */
1105			if (ia) {
1106				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1107				counter_u64_add(ia->ia_ifa.ifa_obytes,
1108				    m->m_pkthdr.len);
1109			}
1110#ifdef RATELIMIT
1111			if (inp != NULL) {
1112				if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
1113					in_pcboutput_txrtlmt(inp, ifp, m);
1114				/* stamp send tag on mbuf */
1115				m->m_pkthdr.snd_tag = inp->inp_snd_tag;
1116				m->m_pkthdr.csum_flags |= CSUM_SND_TAG;
1117			} else {
1118				m->m_pkthdr.snd_tag = NULL;
1119			}
1120#endif
1121			if (vlan_pcp > -1)
1122				EVL_APPLY_PRI(m, vlan_pcp);
1123			error = nd6_output_ifp(ifp, origifp, m, dst,
1124			    (struct route *)ro);
1125#ifdef RATELIMIT
1126			/* check for route change */
1127			if (error == EAGAIN)
1128				in_pcboutput_eagain(inp);
1129#endif
1130		} else
1131			m_freem(m);
1132	}
1133
1134	if (error == 0)
1135		IP6STAT_INC(ip6s_fragmented);
1136
1137done:
1138	if (ro == &ip6route)
1139		RO_RTFREE(ro);
1140	return (error);
1141
1142freehdrs:
1143	m_freem(exthdrs.ip6e_hbh);	/* m_freem() checks if mbuf is NULL. */
1144	m_freem(exthdrs.ip6e_dest1);
1145	m_freem(exthdrs.ip6e_rthdr);
1146	m_freem(exthdrs.ip6e_dest2);
1147	/* FALLTHROUGH */
1148bad:
1149	if (m)
1150		m_freem(m);
1151	goto done;
1152}
1153
1154static int
1155ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1156{
1157	struct mbuf *m;
1158
1159	if (hlen > MCLBYTES)
1160		return (ENOBUFS); /* XXX */
1161
1162	if (hlen > MLEN)
1163		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1164	else
1165		m = m_get(M_NOWAIT, MT_DATA);
1166	if (m == NULL)
1167		return (ENOBUFS);
1168	m->m_len = hlen;
1169	if (hdr)
1170		bcopy(hdr, mtod(m, caddr_t), hlen);
1171
1172	*mp = m;
1173	return (0);
1174}
1175
1176/*
1177 * Insert jumbo payload option.
1178 */
1179static int
1180ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1181{
1182	struct mbuf *mopt;
1183	u_char *optbuf;
1184	u_int32_t v;
1185
1186#define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1187
1188	/*
1189	 * If there is no hop-by-hop options header, allocate new one.
1190	 * If there is one but it doesn't have enough space to store the
1191	 * jumbo payload option, allocate a cluster to store the whole options.
1192	 * Otherwise, use it to store the options.
1193	 */
1194	if (exthdrs->ip6e_hbh == NULL) {
1195		mopt = m_get(M_NOWAIT, MT_DATA);
1196		if (mopt == NULL)
1197			return (ENOBUFS);
1198		mopt->m_len = JUMBOOPTLEN;
1199		optbuf = mtod(mopt, u_char *);
1200		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1201		exthdrs->ip6e_hbh = mopt;
1202	} else {
1203		struct ip6_hbh *hbh;
1204
1205		mopt = exthdrs->ip6e_hbh;
1206		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1207			/*
1208			 * XXX assumption:
1209			 * - exthdrs->ip6e_hbh is not referenced from places
1210			 *   other than exthdrs.
1211			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1212			 */
1213			int oldoptlen = mopt->m_len;
1214			struct mbuf *n;
1215
1216			/*
1217			 * XXX: give up if the whole (new) hbh header does
1218			 * not fit even in an mbuf cluster.
1219			 */
1220			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1221				return (ENOBUFS);
1222
1223			/*
1224			 * As a consequence, we must always prepare a cluster
1225			 * at this point.
1226			 */
1227			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1228			if (n == NULL)
1229				return (ENOBUFS);
1230			n->m_len = oldoptlen + JUMBOOPTLEN;
1231			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1232			    oldoptlen);
1233			optbuf = mtod(n, caddr_t) + oldoptlen;
1234			m_freem(mopt);
1235			mopt = exthdrs->ip6e_hbh = n;
1236		} else {
1237			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1238			mopt->m_len += JUMBOOPTLEN;
1239		}
1240		optbuf[0] = IP6OPT_PADN;
1241		optbuf[1] = 1;
1242
1243		/*
1244		 * Adjust the header length according to the pad and
1245		 * the jumbo payload option.
1246		 */
1247		hbh = mtod(mopt, struct ip6_hbh *);
1248		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1249	}
1250
1251	/* fill in the option. */
1252	optbuf[2] = IP6OPT_JUMBO;
1253	optbuf[3] = 4;
1254	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1255	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1256
1257	/* finally, adjust the packet header length */
1258	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1259
1260	return (0);
1261#undef JUMBOOPTLEN
1262}
1263
1264/*
1265 * Insert fragment header and copy unfragmentable header portions.
1266 */
1267static int
1268ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1269    struct ip6_frag **frghdrp)
1270{
1271	struct mbuf *n, *mlast;
1272
1273	if (hlen > sizeof(struct ip6_hdr)) {
1274		n = m_copym(m0, sizeof(struct ip6_hdr),
1275		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1276		if (n == NULL)
1277			return (ENOBUFS);
1278		m->m_next = n;
1279	} else
1280		n = m;
1281
1282	/* Search for the last mbuf of unfragmentable part. */
1283	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1284		;
1285
1286	if (M_WRITABLE(mlast) &&
1287	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1288		/* use the trailing space of the last mbuf for the fragment hdr */
1289		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1290		    mlast->m_len);
1291		mlast->m_len += sizeof(struct ip6_frag);
1292		m->m_pkthdr.len += sizeof(struct ip6_frag);
1293	} else {
1294		/* allocate a new mbuf for the fragment header */
1295		struct mbuf *mfrg;
1296
1297		mfrg = m_get(M_NOWAIT, MT_DATA);
1298		if (mfrg == NULL)
1299			return (ENOBUFS);
1300		mfrg->m_len = sizeof(struct ip6_frag);
1301		*frghdrp = mtod(mfrg, struct ip6_frag *);
1302		mlast->m_next = mfrg;
1303	}
1304
1305	return (0);
1306}
1307
1308/*
1309 * Calculates IPv6 path mtu for destination @dst.
1310 * Resulting MTU is stored in @mtup.
1311 *
1312 * Returns 0 on success.
1313 */
1314static int
1315ip6_getpmtu_ctl(u_int fibnum, const struct in6_addr *dst, u_long *mtup)
1316{
1317	struct nhop6_extended nh6;
1318	struct in6_addr kdst;
1319	uint32_t scopeid;
1320	struct ifnet *ifp;
1321	u_long mtu;
1322	int error;
1323
1324	in6_splitscope(dst, &kdst, &scopeid);
1325	if (fib6_lookup_nh_ext(fibnum, &kdst, scopeid, NHR_REF, 0, &nh6) != 0)
1326		return (EHOSTUNREACH);
1327
1328	ifp = nh6.nh_ifp;
1329	mtu = nh6.nh_mtu;
1330
1331	error = ip6_calcmtu(ifp, dst, mtu, mtup, NULL, 0);
1332	fib6_free_nh_ext(fibnum, &nh6);
1333
1334	return (error);
1335}
1336
1337/*
1338 * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1339 * and cached data in @ro_pmtu.
1340 * MTU from (successful) route lookup is saved (along with dst)
1341 * inside @ro_pmtu to avoid subsequent route lookups after packet
1342 * filter processing.
1343 *
1344 * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1345 * Returns 0 on success.
1346 */
1347static int
1348ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1349    struct ifnet *ifp, const struct in6_addr *dst, u_long *mtup,
1350    int *alwaysfragp, u_int fibnum, u_int proto)
1351{
1352	struct nhop6_basic nh6;
1353	struct in6_addr kdst;
1354	uint32_t scopeid;
1355	struct sockaddr_in6 *sa6_dst;
1356	u_long mtu;
1357
1358	mtu = 0;
1359	if (do_lookup) {
1360
1361		/*
1362		 * Here ro_pmtu has final destination address, while
1363		 * ro might represent immediate destination.
1364		 * Use ro_pmtu destination since mtu might differ.
1365		 */
1366		sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1367		if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1368			ro_pmtu->ro_mtu = 0;
1369
1370		if (ro_pmtu->ro_mtu == 0) {
1371			bzero(sa6_dst, sizeof(*sa6_dst));
1372			sa6_dst->sin6_family = AF_INET6;
1373			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1374			sa6_dst->sin6_addr = *dst;
1375
1376			in6_splitscope(dst, &kdst, &scopeid);
1377			if (fib6_lookup_nh_basic(fibnum, &kdst, scopeid, 0, 0,
1378			    &nh6) == 0)
1379				ro_pmtu->ro_mtu = nh6.nh_mtu;
1380		}
1381
1382		mtu = ro_pmtu->ro_mtu;
1383	}
1384
1385	if (ro_pmtu->ro_rt)
1386		mtu = ro_pmtu->ro_rt->rt_mtu;
1387
1388	return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp, proto));
1389}
1390
1391/*
1392 * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1393 * hostcache data for @dst.
1394 * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1395 *
1396 * Returns 0 on success.
1397 */
1398static int
1399ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1400    u_long *mtup, int *alwaysfragp, u_int proto)
1401{
1402	u_long mtu = 0;
1403	int alwaysfrag = 0;
1404	int error = 0;
1405
1406	if (rt_mtu > 0) {
1407		u_int32_t ifmtu;
1408		struct in_conninfo inc;
1409
1410		bzero(&inc, sizeof(inc));
1411		inc.inc_flags |= INC_ISIPV6;
1412		inc.inc6_faddr = *dst;
1413
1414		ifmtu = IN6_LINKMTU(ifp);
1415
1416		/* TCP is known to react to pmtu changes so skip hc */
1417		if (proto != IPPROTO_TCP)
1418			mtu = tcp_hc_getmtu(&inc);
1419
1420		if (mtu)
1421			mtu = min(mtu, rt_mtu);
1422		else
1423			mtu = rt_mtu;
1424		if (mtu == 0)
1425			mtu = ifmtu;
1426		else if (mtu < IPV6_MMTU) {
1427			/*
1428			 * RFC2460 section 5, last paragraph:
1429			 * if we record ICMPv6 too big message with
1430			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1431			 * or smaller, with framgent header attached.
1432			 * (fragment header is needed regardless from the
1433			 * packet size, for translators to identify packets)
1434			 */
1435			alwaysfrag = 1;
1436			mtu = IPV6_MMTU;
1437		}
1438	} else if (ifp) {
1439		mtu = IN6_LINKMTU(ifp);
1440	} else
1441		error = EHOSTUNREACH; /* XXX */
1442
1443	*mtup = mtu;
1444	if (alwaysfragp)
1445		*alwaysfragp = alwaysfrag;
1446	return (error);
1447}
1448
1449/*
1450 * IP6 socket option processing.
1451 */
1452int
1453ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1454{
1455	int optdatalen, uproto;
1456	void *optdata;
1457	struct inpcb *inp = sotoinpcb(so);
1458	int error, optval;
1459	int level, op, optname;
1460	int optlen;
1461	struct thread *td;
1462#ifdef	RSS
1463	uint32_t rss_bucket;
1464	int retval;
1465#endif
1466
1467/*
1468 * Don't use more than a quarter of mbuf clusters.  N.B.:
1469 * nmbclusters is an int, but nmbclusters * MCLBYTES may overflow
1470 * on LP64 architectures, so cast to u_long to avoid undefined
1471 * behavior.  ILP32 architectures cannot have nmbclusters
1472 * large enough to overflow for other reasons.
1473 */
1474#define IPV6_PKTOPTIONS_MBUF_LIMIT	((u_long)nmbclusters * MCLBYTES / 4)
1475
1476	level = sopt->sopt_level;
1477	op = sopt->sopt_dir;
1478	optname = sopt->sopt_name;
1479	optlen = sopt->sopt_valsize;
1480	td = sopt->sopt_td;
1481	error = 0;
1482	optval = 0;
1483	uproto = (int)so->so_proto->pr_protocol;
1484
1485	if (level != IPPROTO_IPV6) {
1486		error = EINVAL;
1487
1488		if (sopt->sopt_level == SOL_SOCKET &&
1489		    sopt->sopt_dir == SOPT_SET) {
1490			switch (sopt->sopt_name) {
1491			case SO_REUSEADDR:
1492				INP_WLOCK(inp);
1493				if ((so->so_options & SO_REUSEADDR) != 0)
1494					inp->inp_flags2 |= INP_REUSEADDR;
1495				else
1496					inp->inp_flags2 &= ~INP_REUSEADDR;
1497				INP_WUNLOCK(inp);
1498				error = 0;
1499				break;
1500			case SO_REUSEPORT:
1501				INP_WLOCK(inp);
1502				if ((so->so_options & SO_REUSEPORT) != 0)
1503					inp->inp_flags2 |= INP_REUSEPORT;
1504				else
1505					inp->inp_flags2 &= ~INP_REUSEPORT;
1506				INP_WUNLOCK(inp);
1507				error = 0;
1508				break;
1509			case SO_REUSEPORT_LB:
1510				INP_WLOCK(inp);
1511				if ((so->so_options & SO_REUSEPORT_LB) != 0)
1512					inp->inp_flags2 |= INP_REUSEPORT_LB;
1513				else
1514					inp->inp_flags2 &= ~INP_REUSEPORT_LB;
1515				INP_WUNLOCK(inp);
1516				error = 0;
1517				break;
1518			case SO_SETFIB:
1519				INP_WLOCK(inp);
1520				inp->inp_inc.inc_fibnum = so->so_fibnum;
1521				INP_WUNLOCK(inp);
1522				error = 0;
1523				break;
1524			case SO_MAX_PACING_RATE:
1525#ifdef RATELIMIT
1526				INP_WLOCK(inp);
1527				inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1528				INP_WUNLOCK(inp);
1529				error = 0;
1530#else
1531				error = EOPNOTSUPP;
1532#endif
1533				break;
1534			default:
1535				break;
1536			}
1537		}
1538	} else {		/* level == IPPROTO_IPV6 */
1539		switch (op) {
1540
1541		case SOPT_SET:
1542			switch (optname) {
1543			case IPV6_2292PKTOPTIONS:
1544#ifdef IPV6_PKTOPTIONS
1545			case IPV6_PKTOPTIONS:
1546#endif
1547			{
1548				struct mbuf *m;
1549
1550				if (optlen > IPV6_PKTOPTIONS_MBUF_LIMIT) {
1551					printf("ip6_ctloutput: mbuf limit hit\n");
1552					error = ENOBUFS;
1553					break;
1554				}
1555
1556				error = soopt_getm(sopt, &m); /* XXX */
1557				if (error != 0)
1558					break;
1559				error = soopt_mcopyin(sopt, m); /* XXX */
1560				if (error != 0)
1561					break;
1562				INP_WLOCK(inp);
1563				error = ip6_pcbopts(&inp->in6p_outputopts, m,
1564				    so, sopt);
1565				INP_WUNLOCK(inp);
1566				m_freem(m); /* XXX */
1567				break;
1568			}
1569
1570			/*
1571			 * Use of some Hop-by-Hop options or some
1572			 * Destination options, might require special
1573			 * privilege.  That is, normal applications
1574			 * (without special privilege) might be forbidden
1575			 * from setting certain options in outgoing packets,
1576			 * and might never see certain options in received
1577			 * packets. [RFC 2292 Section 6]
1578			 * KAME specific note:
1579			 *  KAME prevents non-privileged users from sending or
1580			 *  receiving ANY hbh/dst options in order to avoid
1581			 *  overhead of parsing options in the kernel.
1582			 */
1583			case IPV6_RECVHOPOPTS:
1584			case IPV6_RECVDSTOPTS:
1585			case IPV6_RECVRTHDRDSTOPTS:
1586				if (td != NULL) {
1587					error = priv_check(td,
1588					    PRIV_NETINET_SETHDROPTS);
1589					if (error)
1590						break;
1591				}
1592				/* FALLTHROUGH */
1593			case IPV6_UNICAST_HOPS:
1594			case IPV6_HOPLIMIT:
1595
1596			case IPV6_RECVPKTINFO:
1597			case IPV6_RECVHOPLIMIT:
1598			case IPV6_RECVRTHDR:
1599			case IPV6_RECVPATHMTU:
1600			case IPV6_RECVTCLASS:
1601			case IPV6_RECVFLOWID:
1602#ifdef	RSS
1603			case IPV6_RECVRSSBUCKETID:
1604#endif
1605			case IPV6_V6ONLY:
1606			case IPV6_AUTOFLOWLABEL:
1607			case IPV6_ORIGDSTADDR:
1608			case IPV6_BINDANY:
1609			case IPV6_BINDMULTI:
1610#ifdef	RSS
1611			case IPV6_RSS_LISTEN_BUCKET:
1612#endif
1613			case IPV6_VLAN_PCP:
1614				if (optname == IPV6_BINDANY && td != NULL) {
1615					error = priv_check(td,
1616					    PRIV_NETINET_BINDANY);
1617					if (error)
1618						break;
1619				}
1620
1621				if (optlen != sizeof(int)) {
1622					error = EINVAL;
1623					break;
1624				}
1625				error = sooptcopyin(sopt, &optval,
1626					sizeof optval, sizeof optval);
1627				if (error)
1628					break;
1629				switch (optname) {
1630
1631				case IPV6_UNICAST_HOPS:
1632					if (optval < -1 || optval >= 256)
1633						error = EINVAL;
1634					else {
1635						/* -1 = kernel default */
1636						inp->in6p_hops = optval;
1637						if ((inp->inp_vflag &
1638						     INP_IPV4) != 0)
1639							inp->inp_ip_ttl = optval;
1640					}
1641					break;
1642#define OPTSET(bit) \
1643do { \
1644	INP_WLOCK(inp); \
1645	if (optval) \
1646		inp->inp_flags |= (bit); \
1647	else \
1648		inp->inp_flags &= ~(bit); \
1649	INP_WUNLOCK(inp); \
1650} while (/*CONSTCOND*/ 0)
1651#define OPTSET2292(bit) \
1652do { \
1653	INP_WLOCK(inp); \
1654	inp->inp_flags |= IN6P_RFC2292; \
1655	if (optval) \
1656		inp->inp_flags |= (bit); \
1657	else \
1658		inp->inp_flags &= ~(bit); \
1659	INP_WUNLOCK(inp); \
1660} while (/*CONSTCOND*/ 0)
1661#define OPTBIT(bit) (inp->inp_flags & (bit) ? 1 : 0)
1662
1663#define OPTSET2_N(bit, val) do {					\
1664	if (val)							\
1665		inp->inp_flags2 |= bit;					\
1666	else								\
1667		inp->inp_flags2 &= ~bit;				\
1668} while (0)
1669#define OPTSET2(bit, val) do {						\
1670	INP_WLOCK(inp);							\
1671	OPTSET2_N(bit, val);						\
1672	INP_WUNLOCK(inp);						\
1673} while (0)
1674#define OPTBIT2(bit) (inp->inp_flags2 & (bit) ? 1 : 0)
1675#define OPTSET2292_EXCLUSIVE(bit)					\
1676do {									\
1677	INP_WLOCK(inp);							\
1678	if (OPTBIT(IN6P_RFC2292)) {					\
1679		error = EINVAL;						\
1680	} else {							\
1681		if (optval)						\
1682			inp->inp_flags |= (bit);			\
1683		else							\
1684			inp->inp_flags &= ~(bit);			\
1685	}								\
1686	INP_WUNLOCK(inp);						\
1687} while (/*CONSTCOND*/ 0)
1688
1689				case IPV6_RECVPKTINFO:
1690					OPTSET2292_EXCLUSIVE(IN6P_PKTINFO);
1691					break;
1692
1693				case IPV6_HOPLIMIT:
1694				{
1695					struct ip6_pktopts **optp;
1696
1697					/* cannot mix with RFC2292 */
1698					if (OPTBIT(IN6P_RFC2292)) {
1699						error = EINVAL;
1700						break;
1701					}
1702					INP_WLOCK(inp);
1703					if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1704						INP_WUNLOCK(inp);
1705						return (ECONNRESET);
1706					}
1707					optp = &inp->in6p_outputopts;
1708					error = ip6_pcbopt(IPV6_HOPLIMIT,
1709					    (u_char *)&optval, sizeof(optval),
1710					    optp, (td != NULL) ? td->td_ucred :
1711					    NULL, uproto);
1712					INP_WUNLOCK(inp);
1713					break;
1714				}
1715
1716				case IPV6_RECVHOPLIMIT:
1717					OPTSET2292_EXCLUSIVE(IN6P_HOPLIMIT);
1718					break;
1719
1720				case IPV6_RECVHOPOPTS:
1721					OPTSET2292_EXCLUSIVE(IN6P_HOPOPTS);
1722					break;
1723
1724				case IPV6_RECVDSTOPTS:
1725					OPTSET2292_EXCLUSIVE(IN6P_DSTOPTS);
1726					break;
1727
1728				case IPV6_RECVRTHDRDSTOPTS:
1729					OPTSET2292_EXCLUSIVE(IN6P_RTHDRDSTOPTS);
1730					break;
1731
1732				case IPV6_RECVRTHDR:
1733					OPTSET2292_EXCLUSIVE(IN6P_RTHDR);
1734					break;
1735
1736				case IPV6_RECVPATHMTU:
1737					/*
1738					 * We ignore this option for TCP
1739					 * sockets.
1740					 * (RFC3542 leaves this case
1741					 * unspecified.)
1742					 */
1743					if (uproto != IPPROTO_TCP)
1744						OPTSET(IN6P_MTU);
1745					break;
1746
1747				case IPV6_RECVFLOWID:
1748					OPTSET2(INP_RECVFLOWID, optval);
1749					break;
1750
1751#ifdef	RSS
1752				case IPV6_RECVRSSBUCKETID:
1753					OPTSET2(INP_RECVRSSBUCKETID, optval);
1754					break;
1755#endif
1756
1757				case IPV6_V6ONLY:
1758					/*
1759					 * make setsockopt(IPV6_V6ONLY)
1760					 * available only prior to bind(2).
1761					 * see ipng mailing list, Jun 22 2001.
1762					 */
1763					if (inp->inp_lport ||
1764					    !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
1765						error = EINVAL;
1766						break;
1767					}
1768					OPTSET(IN6P_IPV6_V6ONLY);
1769					if (optval)
1770						inp->inp_vflag &= ~INP_IPV4;
1771					else
1772						inp->inp_vflag |= INP_IPV4;
1773					break;
1774				case IPV6_RECVTCLASS:
1775					/* cannot mix with RFC2292 XXX */
1776					OPTSET2292_EXCLUSIVE(IN6P_TCLASS);
1777					break;
1778				case IPV6_AUTOFLOWLABEL:
1779					OPTSET(IN6P_AUTOFLOWLABEL);
1780					break;
1781
1782				case IPV6_ORIGDSTADDR:
1783					OPTSET2(INP_ORIGDSTADDR, optval);
1784					break;
1785				case IPV6_BINDANY:
1786					OPTSET(INP_BINDANY);
1787					break;
1788
1789				case IPV6_BINDMULTI:
1790					OPTSET2(INP_BINDMULTI, optval);
1791					break;
1792#ifdef	RSS
1793				case IPV6_RSS_LISTEN_BUCKET:
1794					if ((optval >= 0) &&
1795					    (optval < rss_getnumbuckets())) {
1796						INP_WLOCK(inp);
1797						inp->inp_rss_listen_bucket = optval;
1798						OPTSET2_N(INP_RSS_BUCKET_SET, 1);
1799						INP_WUNLOCK(inp);
1800					} else {
1801						error = EINVAL;
1802					}
1803					break;
1804#endif
1805				case IPV6_VLAN_PCP:
1806					if ((optval >= -1) && (optval <=
1807					    (INP_2PCP_MASK >> INP_2PCP_SHIFT))) {
1808						if (optval == -1) {
1809							INP_WLOCK(inp);
1810							inp->inp_flags2 &=
1811							    ~(INP_2PCP_SET |
1812							    INP_2PCP_MASK);
1813							INP_WUNLOCK(inp);
1814						} else {
1815							INP_WLOCK(inp);
1816							inp->inp_flags2 |=
1817							    INP_2PCP_SET;
1818							inp->inp_flags2 &=
1819							    ~INP_2PCP_MASK;
1820							inp->inp_flags2 |=
1821							    optval <<
1822							    INP_2PCP_SHIFT;
1823							INP_WUNLOCK(inp);
1824						}
1825					} else
1826						error = EINVAL;
1827					break;
1828				}
1829				break;
1830
1831			case IPV6_TCLASS:
1832			case IPV6_DONTFRAG:
1833			case IPV6_USE_MIN_MTU:
1834			case IPV6_PREFER_TEMPADDR:
1835				if (optlen != sizeof(optval)) {
1836					error = EINVAL;
1837					break;
1838				}
1839				error = sooptcopyin(sopt, &optval,
1840					sizeof optval, sizeof optval);
1841				if (error)
1842					break;
1843				{
1844					struct ip6_pktopts **optp;
1845					INP_WLOCK(inp);
1846					if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1847						INP_WUNLOCK(inp);
1848						return (ECONNRESET);
1849					}
1850					optp = &inp->in6p_outputopts;
1851					error = ip6_pcbopt(optname,
1852					    (u_char *)&optval, sizeof(optval),
1853					    optp, (td != NULL) ? td->td_ucred :
1854					    NULL, uproto);
1855					INP_WUNLOCK(inp);
1856					break;
1857				}
1858
1859			case IPV6_2292PKTINFO:
1860			case IPV6_2292HOPLIMIT:
1861			case IPV6_2292HOPOPTS:
1862			case IPV6_2292DSTOPTS:
1863			case IPV6_2292RTHDR:
1864				/* RFC 2292 */
1865				if (optlen != sizeof(int)) {
1866					error = EINVAL;
1867					break;
1868				}
1869				error = sooptcopyin(sopt, &optval,
1870					sizeof optval, sizeof optval);
1871				if (error)
1872					break;
1873				switch (optname) {
1874				case IPV6_2292PKTINFO:
1875					OPTSET2292(IN6P_PKTINFO);
1876					break;
1877				case IPV6_2292HOPLIMIT:
1878					OPTSET2292(IN6P_HOPLIMIT);
1879					break;
1880				case IPV6_2292HOPOPTS:
1881					/*
1882					 * Check super-user privilege.
1883					 * See comments for IPV6_RECVHOPOPTS.
1884					 */
1885					if (td != NULL) {
1886						error = priv_check(td,
1887						    PRIV_NETINET_SETHDROPTS);
1888						if (error)
1889							return (error);
1890					}
1891					OPTSET2292(IN6P_HOPOPTS);
1892					break;
1893				case IPV6_2292DSTOPTS:
1894					if (td != NULL) {
1895						error = priv_check(td,
1896						    PRIV_NETINET_SETHDROPTS);
1897						if (error)
1898							return (error);
1899					}
1900					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1901					break;
1902				case IPV6_2292RTHDR:
1903					OPTSET2292(IN6P_RTHDR);
1904					break;
1905				}
1906				break;
1907			case IPV6_PKTINFO:
1908			case IPV6_HOPOPTS:
1909			case IPV6_RTHDR:
1910			case IPV6_DSTOPTS:
1911			case IPV6_RTHDRDSTOPTS:
1912			case IPV6_NEXTHOP:
1913			{
1914				/* new advanced API (RFC3542) */
1915				u_char *optbuf;
1916				u_char optbuf_storage[MCLBYTES];
1917				int optlen;
1918				struct ip6_pktopts **optp;
1919
1920				/* cannot mix with RFC2292 */
1921				if (OPTBIT(IN6P_RFC2292)) {
1922					error = EINVAL;
1923					break;
1924				}
1925
1926				/*
1927				 * We only ensure valsize is not too large
1928				 * here.  Further validation will be done
1929				 * later.
1930				 */
1931				error = sooptcopyin(sopt, optbuf_storage,
1932				    sizeof(optbuf_storage), 0);
1933				if (error)
1934					break;
1935				optlen = sopt->sopt_valsize;
1936				optbuf = optbuf_storage;
1937				INP_WLOCK(inp);
1938				if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1939					INP_WUNLOCK(inp);
1940					return (ECONNRESET);
1941				}
1942				optp = &inp->in6p_outputopts;
1943				error = ip6_pcbopt(optname, optbuf, optlen,
1944				    optp, (td != NULL) ? td->td_ucred : NULL,
1945				    uproto);
1946				INP_WUNLOCK(inp);
1947				break;
1948			}
1949#undef OPTSET
1950
1951			case IPV6_MULTICAST_IF:
1952			case IPV6_MULTICAST_HOPS:
1953			case IPV6_MULTICAST_LOOP:
1954			case IPV6_JOIN_GROUP:
1955			case IPV6_LEAVE_GROUP:
1956			case IPV6_MSFILTER:
1957			case MCAST_BLOCK_SOURCE:
1958			case MCAST_UNBLOCK_SOURCE:
1959			case MCAST_JOIN_GROUP:
1960			case MCAST_LEAVE_GROUP:
1961			case MCAST_JOIN_SOURCE_GROUP:
1962			case MCAST_LEAVE_SOURCE_GROUP:
1963				error = ip6_setmoptions(inp, sopt);
1964				break;
1965
1966			case IPV6_PORTRANGE:
1967				error = sooptcopyin(sopt, &optval,
1968				    sizeof optval, sizeof optval);
1969				if (error)
1970					break;
1971
1972				INP_WLOCK(inp);
1973				switch (optval) {
1974				case IPV6_PORTRANGE_DEFAULT:
1975					inp->inp_flags &= ~(INP_LOWPORT);
1976					inp->inp_flags &= ~(INP_HIGHPORT);
1977					break;
1978
1979				case IPV6_PORTRANGE_HIGH:
1980					inp->inp_flags &= ~(INP_LOWPORT);
1981					inp->inp_flags |= INP_HIGHPORT;
1982					break;
1983
1984				case IPV6_PORTRANGE_LOW:
1985					inp->inp_flags &= ~(INP_HIGHPORT);
1986					inp->inp_flags |= INP_LOWPORT;
1987					break;
1988
1989				default:
1990					error = EINVAL;
1991					break;
1992				}
1993				INP_WUNLOCK(inp);
1994				break;
1995
1996#if defined(IPSEC) || defined(IPSEC_SUPPORT)
1997			case IPV6_IPSEC_POLICY:
1998				if (IPSEC_ENABLED(ipv6)) {
1999					error = IPSEC_PCBCTL(ipv6, inp, sopt);
2000					break;
2001				}
2002				/* FALLTHROUGH */
2003#endif /* IPSEC */
2004
2005			default:
2006				error = ENOPROTOOPT;
2007				break;
2008			}
2009			break;
2010
2011		case SOPT_GET:
2012			switch (optname) {
2013
2014			case IPV6_2292PKTOPTIONS:
2015#ifdef IPV6_PKTOPTIONS
2016			case IPV6_PKTOPTIONS:
2017#endif
2018				/*
2019				 * RFC3542 (effectively) deprecated the
2020				 * semantics of the 2292-style pktoptions.
2021				 * Since it was not reliable in nature (i.e.,
2022				 * applications had to expect the lack of some
2023				 * information after all), it would make sense
2024				 * to simplify this part by always returning
2025				 * empty data.
2026				 */
2027				sopt->sopt_valsize = 0;
2028				break;
2029
2030			case IPV6_RECVHOPOPTS:
2031			case IPV6_RECVDSTOPTS:
2032			case IPV6_RECVRTHDRDSTOPTS:
2033			case IPV6_UNICAST_HOPS:
2034			case IPV6_RECVPKTINFO:
2035			case IPV6_RECVHOPLIMIT:
2036			case IPV6_RECVRTHDR:
2037			case IPV6_RECVPATHMTU:
2038
2039			case IPV6_V6ONLY:
2040			case IPV6_PORTRANGE:
2041			case IPV6_RECVTCLASS:
2042			case IPV6_AUTOFLOWLABEL:
2043			case IPV6_BINDANY:
2044			case IPV6_FLOWID:
2045			case IPV6_FLOWTYPE:
2046			case IPV6_RECVFLOWID:
2047#ifdef	RSS
2048			case IPV6_RSSBUCKETID:
2049			case IPV6_RECVRSSBUCKETID:
2050#endif
2051			case IPV6_BINDMULTI:
2052			case IPV6_VLAN_PCP:
2053				switch (optname) {
2054
2055				case IPV6_RECVHOPOPTS:
2056					optval = OPTBIT(IN6P_HOPOPTS);
2057					break;
2058
2059				case IPV6_RECVDSTOPTS:
2060					optval = OPTBIT(IN6P_DSTOPTS);
2061					break;
2062
2063				case IPV6_RECVRTHDRDSTOPTS:
2064					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
2065					break;
2066
2067				case IPV6_UNICAST_HOPS:
2068					optval = inp->in6p_hops;
2069					break;
2070
2071				case IPV6_RECVPKTINFO:
2072					optval = OPTBIT(IN6P_PKTINFO);
2073					break;
2074
2075				case IPV6_RECVHOPLIMIT:
2076					optval = OPTBIT(IN6P_HOPLIMIT);
2077					break;
2078
2079				case IPV6_RECVRTHDR:
2080					optval = OPTBIT(IN6P_RTHDR);
2081					break;
2082
2083				case IPV6_RECVPATHMTU:
2084					optval = OPTBIT(IN6P_MTU);
2085					break;
2086
2087				case IPV6_V6ONLY:
2088					optval = OPTBIT(IN6P_IPV6_V6ONLY);
2089					break;
2090
2091				case IPV6_PORTRANGE:
2092				    {
2093					int flags;
2094					flags = inp->inp_flags;
2095					if (flags & INP_HIGHPORT)
2096						optval = IPV6_PORTRANGE_HIGH;
2097					else if (flags & INP_LOWPORT)
2098						optval = IPV6_PORTRANGE_LOW;
2099					else
2100						optval = 0;
2101					break;
2102				    }
2103				case IPV6_RECVTCLASS:
2104					optval = OPTBIT(IN6P_TCLASS);
2105					break;
2106
2107				case IPV6_AUTOFLOWLABEL:
2108					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2109					break;
2110
2111				case IPV6_ORIGDSTADDR:
2112					optval = OPTBIT2(INP_ORIGDSTADDR);
2113					break;
2114
2115				case IPV6_BINDANY:
2116					optval = OPTBIT(INP_BINDANY);
2117					break;
2118
2119				case IPV6_FLOWID:
2120					optval = inp->inp_flowid;
2121					break;
2122
2123				case IPV6_FLOWTYPE:
2124					optval = inp->inp_flowtype;
2125					break;
2126
2127				case IPV6_RECVFLOWID:
2128					optval = OPTBIT2(INP_RECVFLOWID);
2129					break;
2130#ifdef	RSS
2131				case IPV6_RSSBUCKETID:
2132					retval =
2133					    rss_hash2bucket(inp->inp_flowid,
2134					    inp->inp_flowtype,
2135					    &rss_bucket);
2136					if (retval == 0)
2137						optval = rss_bucket;
2138					else
2139						error = EINVAL;
2140					break;
2141
2142				case IPV6_RECVRSSBUCKETID:
2143					optval = OPTBIT2(INP_RECVRSSBUCKETID);
2144					break;
2145#endif
2146
2147				case IPV6_BINDMULTI:
2148					optval = OPTBIT2(INP_BINDMULTI);
2149					break;
2150
2151				case IPV6_VLAN_PCP:
2152					if (OPTBIT2(INP_2PCP_SET)) {
2153						optval = (inp->inp_flags2 &
2154							    INP_2PCP_MASK) >>
2155							    INP_2PCP_SHIFT;
2156					} else {
2157						optval = -1;
2158					}
2159					break;
2160				}
2161
2162				if (error)
2163					break;
2164				error = sooptcopyout(sopt, &optval,
2165					sizeof optval);
2166				break;
2167
2168			case IPV6_PATHMTU:
2169			{
2170				u_long pmtu = 0;
2171				struct ip6_mtuinfo mtuinfo;
2172				struct in6_addr addr;
2173
2174				if (!(so->so_state & SS_ISCONNECTED))
2175					return (ENOTCONN);
2176				/*
2177				 * XXX: we dot not consider the case of source
2178				 * routing, or optional information to specify
2179				 * the outgoing interface.
2180				 * Copy faddr out of inp to avoid holding lock
2181				 * on inp during route lookup.
2182				 */
2183				INP_RLOCK(inp);
2184				bcopy(&inp->in6p_faddr, &addr, sizeof(addr));
2185				INP_RUNLOCK(inp);
2186				error = ip6_getpmtu_ctl(so->so_fibnum,
2187				    &addr, &pmtu);
2188				if (error)
2189					break;
2190				if (pmtu > IPV6_MAXPACKET)
2191					pmtu = IPV6_MAXPACKET;
2192
2193				bzero(&mtuinfo, sizeof(mtuinfo));
2194				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2195				optdata = (void *)&mtuinfo;
2196				optdatalen = sizeof(mtuinfo);
2197				error = sooptcopyout(sopt, optdata,
2198				    optdatalen);
2199				break;
2200			}
2201
2202			case IPV6_2292PKTINFO:
2203			case IPV6_2292HOPLIMIT:
2204			case IPV6_2292HOPOPTS:
2205			case IPV6_2292RTHDR:
2206			case IPV6_2292DSTOPTS:
2207				switch (optname) {
2208				case IPV6_2292PKTINFO:
2209					optval = OPTBIT(IN6P_PKTINFO);
2210					break;
2211				case IPV6_2292HOPLIMIT:
2212					optval = OPTBIT(IN6P_HOPLIMIT);
2213					break;
2214				case IPV6_2292HOPOPTS:
2215					optval = OPTBIT(IN6P_HOPOPTS);
2216					break;
2217				case IPV6_2292RTHDR:
2218					optval = OPTBIT(IN6P_RTHDR);
2219					break;
2220				case IPV6_2292DSTOPTS:
2221					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2222					break;
2223				}
2224				error = sooptcopyout(sopt, &optval,
2225				    sizeof optval);
2226				break;
2227			case IPV6_PKTINFO:
2228			case IPV6_HOPOPTS:
2229			case IPV6_RTHDR:
2230			case IPV6_DSTOPTS:
2231			case IPV6_RTHDRDSTOPTS:
2232			case IPV6_NEXTHOP:
2233			case IPV6_TCLASS:
2234			case IPV6_DONTFRAG:
2235			case IPV6_USE_MIN_MTU:
2236			case IPV6_PREFER_TEMPADDR:
2237				error = ip6_getpcbopt(inp, optname, sopt);
2238				break;
2239
2240			case IPV6_MULTICAST_IF:
2241			case IPV6_MULTICAST_HOPS:
2242			case IPV6_MULTICAST_LOOP:
2243			case IPV6_MSFILTER:
2244				error = ip6_getmoptions(inp, sopt);
2245				break;
2246
2247#if defined(IPSEC) || defined(IPSEC_SUPPORT)
2248			case IPV6_IPSEC_POLICY:
2249				if (IPSEC_ENABLED(ipv6)) {
2250					error = IPSEC_PCBCTL(ipv6, inp, sopt);
2251					break;
2252				}
2253				/* FALLTHROUGH */
2254#endif /* IPSEC */
2255			default:
2256				error = ENOPROTOOPT;
2257				break;
2258			}
2259			break;
2260		}
2261	}
2262	return (error);
2263}
2264
2265int
2266ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2267{
2268	int error = 0, optval, optlen;
2269	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2270	struct inpcb *inp = sotoinpcb(so);
2271	int level, op, optname;
2272
2273	level = sopt->sopt_level;
2274	op = sopt->sopt_dir;
2275	optname = sopt->sopt_name;
2276	optlen = sopt->sopt_valsize;
2277
2278	if (level != IPPROTO_IPV6) {
2279		return (EINVAL);
2280	}
2281
2282	switch (optname) {
2283	case IPV6_CHECKSUM:
2284		/*
2285		 * For ICMPv6 sockets, no modification allowed for checksum
2286		 * offset, permit "no change" values to help existing apps.
2287		 *
2288		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2289		 * for an ICMPv6 socket will fail."
2290		 * The current behavior does not meet RFC3542.
2291		 */
2292		switch (op) {
2293		case SOPT_SET:
2294			if (optlen != sizeof(int)) {
2295				error = EINVAL;
2296				break;
2297			}
2298			error = sooptcopyin(sopt, &optval, sizeof(optval),
2299					    sizeof(optval));
2300			if (error)
2301				break;
2302			if (optval < -1 || (optval % 2) != 0) {
2303				/*
2304				 * The API assumes non-negative even offset
2305				 * values or -1 as a special value.
2306				 */
2307				error = EINVAL;
2308			} else if (so->so_proto->pr_protocol ==
2309			    IPPROTO_ICMPV6) {
2310				if (optval != icmp6off)
2311					error = EINVAL;
2312			} else
2313				inp->in6p_cksum = optval;
2314			break;
2315
2316		case SOPT_GET:
2317			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2318				optval = icmp6off;
2319			else
2320				optval = inp->in6p_cksum;
2321
2322			error = sooptcopyout(sopt, &optval, sizeof(optval));
2323			break;
2324
2325		default:
2326			error = EINVAL;
2327			break;
2328		}
2329		break;
2330
2331	default:
2332		error = ENOPROTOOPT;
2333		break;
2334	}
2335
2336	return (error);
2337}
2338
2339/*
2340 * Set up IP6 options in pcb for insertion in output packets or
2341 * specifying behavior of outgoing packets.
2342 */
2343static int
2344ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2345    struct socket *so, struct sockopt *sopt)
2346{
2347	struct ip6_pktopts *opt = *pktopt;
2348	int error = 0;
2349	struct thread *td = sopt->sopt_td;
2350
2351	/* turn off any old options. */
2352	if (opt) {
2353#ifdef DIAGNOSTIC
2354		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2355		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2356		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2357			printf("ip6_pcbopts: all specified options are cleared.\n");
2358#endif
2359		ip6_clearpktopts(opt, -1);
2360	} else {
2361		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
2362		if (opt == NULL)
2363			return (ENOMEM);
2364	}
2365	*pktopt = NULL;
2366
2367	if (!m || m->m_len == 0) {
2368		/*
2369		 * Only turning off any previous options, regardless of
2370		 * whether the opt is just created or given.
2371		 */
2372		free(opt, M_IP6OPT);
2373		return (0);
2374	}
2375
2376	/*  set options specified by user. */
2377	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2378	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2379		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2380		free(opt, M_IP6OPT);
2381		return (error);
2382	}
2383	*pktopt = opt;
2384	return (0);
2385}
2386
2387/*
2388 * initialize ip6_pktopts.  beware that there are non-zero default values in
2389 * the struct.
2390 */
2391void
2392ip6_initpktopts(struct ip6_pktopts *opt)
2393{
2394
2395	bzero(opt, sizeof(*opt));
2396	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2397	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2398	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2399	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2400}
2401
2402static int
2403ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2404    struct ucred *cred, int uproto)
2405{
2406	struct ip6_pktopts *opt;
2407
2408	if (*pktopt == NULL) {
2409		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2410		    M_NOWAIT);
2411		if (*pktopt == NULL)
2412			return (ENOBUFS);
2413		ip6_initpktopts(*pktopt);
2414	}
2415	opt = *pktopt;
2416
2417	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2418}
2419
2420#define GET_PKTOPT_VAR(field, lenexpr) do {					\
2421	if (pktopt && pktopt->field) {						\
2422		INP_RUNLOCK(inp);						\
2423		optdata = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK);		\
2424		malloc_optdata = true;						\
2425		INP_RLOCK(inp);							\
2426		if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {		\
2427			INP_RUNLOCK(inp);					\
2428			free(optdata, M_TEMP);					\
2429			return (ECONNRESET);					\
2430		}								\
2431		pktopt = inp->in6p_outputopts;					\
2432		if (pktopt && pktopt->field) {					\
2433			optdatalen = min(lenexpr, sopt->sopt_valsize);		\
2434			bcopy(&pktopt->field, optdata, optdatalen);		\
2435		} else {							\
2436			free(optdata, M_TEMP);					\
2437			optdata = NULL;						\
2438			malloc_optdata = false;					\
2439		}								\
2440	}									\
2441} while(0)
2442
2443#define GET_PKTOPT_EXT_HDR(field) GET_PKTOPT_VAR(field,				\
2444	(((struct ip6_ext *)pktopt->field)->ip6e_len + 1) << 3)
2445
2446#define GET_PKTOPT_SOCKADDR(field) GET_PKTOPT_VAR(field,			\
2447	pktopt->field->sa_len)
2448
2449static int
2450ip6_getpcbopt(struct inpcb *inp, int optname, struct sockopt *sopt)
2451{
2452	void *optdata = NULL;
2453	bool malloc_optdata = false;
2454	int optdatalen = 0;
2455	int error = 0;
2456	struct in6_pktinfo null_pktinfo;
2457	int deftclass = 0, on;
2458	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2459	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2460	struct ip6_pktopts *pktopt;
2461
2462	INP_RLOCK(inp);
2463	pktopt = inp->in6p_outputopts;
2464
2465	switch (optname) {
2466	case IPV6_PKTINFO:
2467		optdata = (void *)&null_pktinfo;
2468		if (pktopt && pktopt->ip6po_pktinfo) {
2469			bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2470			    sizeof(null_pktinfo));
2471			in6_clearscope(&null_pktinfo.ipi6_addr);
2472		} else {
2473			/* XXX: we don't have to do this every time... */
2474			bzero(&null_pktinfo, sizeof(null_pktinfo));
2475		}
2476		optdatalen = sizeof(struct in6_pktinfo);
2477		break;
2478	case IPV6_TCLASS:
2479		if (pktopt && pktopt->ip6po_tclass >= 0)
2480			deftclass = pktopt->ip6po_tclass;
2481		optdata = (void *)&deftclass;
2482		optdatalen = sizeof(int);
2483		break;
2484	case IPV6_HOPOPTS:
2485		GET_PKTOPT_EXT_HDR(ip6po_hbh);
2486		break;
2487	case IPV6_RTHDR:
2488		GET_PKTOPT_EXT_HDR(ip6po_rthdr);
2489		break;
2490	case IPV6_RTHDRDSTOPTS:
2491		GET_PKTOPT_EXT_HDR(ip6po_dest1);
2492		break;
2493	case IPV6_DSTOPTS:
2494		GET_PKTOPT_EXT_HDR(ip6po_dest2);
2495		break;
2496	case IPV6_NEXTHOP:
2497		GET_PKTOPT_SOCKADDR(ip6po_nexthop);
2498		break;
2499	case IPV6_USE_MIN_MTU:
2500		if (pktopt)
2501			defminmtu = pktopt->ip6po_minmtu;
2502		optdata = (void *)&defminmtu;
2503		optdatalen = sizeof(int);
2504		break;
2505	case IPV6_DONTFRAG:
2506		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2507			on = 1;
2508		else
2509			on = 0;
2510		optdata = (void *)&on;
2511		optdatalen = sizeof(on);
2512		break;
2513	case IPV6_PREFER_TEMPADDR:
2514		if (pktopt)
2515			defpreftemp = pktopt->ip6po_prefer_tempaddr;
2516		optdata = (void *)&defpreftemp;
2517		optdatalen = sizeof(int);
2518		break;
2519	default:		/* should not happen */
2520#ifdef DIAGNOSTIC
2521		panic("ip6_getpcbopt: unexpected option\n");
2522#endif
2523		INP_RUNLOCK(inp);
2524		return (ENOPROTOOPT);
2525	}
2526	INP_RUNLOCK(inp);
2527
2528	error = sooptcopyout(sopt, optdata, optdatalen);
2529	if (malloc_optdata)
2530		free(optdata, M_TEMP);
2531
2532	return (error);
2533}
2534
2535void
2536ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2537{
2538	if (pktopt == NULL)
2539		return;
2540
2541	if (optname == -1 || optname == IPV6_PKTINFO) {
2542		if (pktopt->ip6po_pktinfo)
2543			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2544		pktopt->ip6po_pktinfo = NULL;
2545	}
2546	if (optname == -1 || optname == IPV6_HOPLIMIT)
2547		pktopt->ip6po_hlim = -1;
2548	if (optname == -1 || optname == IPV6_TCLASS)
2549		pktopt->ip6po_tclass = -1;
2550	if (optname == -1 || optname == IPV6_NEXTHOP) {
2551		if (pktopt->ip6po_nextroute.ro_rt) {
2552			RTFREE(pktopt->ip6po_nextroute.ro_rt);
2553			pktopt->ip6po_nextroute.ro_rt = NULL;
2554		}
2555		if (pktopt->ip6po_nexthop)
2556			free(pktopt->ip6po_nexthop, M_IP6OPT);
2557		pktopt->ip6po_nexthop = NULL;
2558	}
2559	if (optname == -1 || optname == IPV6_HOPOPTS) {
2560		if (pktopt->ip6po_hbh)
2561			free(pktopt->ip6po_hbh, M_IP6OPT);
2562		pktopt->ip6po_hbh = NULL;
2563	}
2564	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2565		if (pktopt->ip6po_dest1)
2566			free(pktopt->ip6po_dest1, M_IP6OPT);
2567		pktopt->ip6po_dest1 = NULL;
2568	}
2569	if (optname == -1 || optname == IPV6_RTHDR) {
2570		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2571			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2572		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2573		if (pktopt->ip6po_route.ro_rt) {
2574			RTFREE(pktopt->ip6po_route.ro_rt);
2575			pktopt->ip6po_route.ro_rt = NULL;
2576		}
2577	}
2578	if (optname == -1 || optname == IPV6_DSTOPTS) {
2579		if (pktopt->ip6po_dest2)
2580			free(pktopt->ip6po_dest2, M_IP6OPT);
2581		pktopt->ip6po_dest2 = NULL;
2582	}
2583}
2584
2585#define PKTOPT_EXTHDRCPY(type) \
2586do {\
2587	if (src->type) {\
2588		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2589		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2590		if (dst->type == NULL)\
2591			goto bad;\
2592		bcopy(src->type, dst->type, hlen);\
2593	}\
2594} while (/*CONSTCOND*/ 0)
2595
2596static int
2597copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2598{
2599	if (dst == NULL || src == NULL)  {
2600		printf("ip6_clearpktopts: invalid argument\n");
2601		return (EINVAL);
2602	}
2603
2604	dst->ip6po_hlim = src->ip6po_hlim;
2605	dst->ip6po_tclass = src->ip6po_tclass;
2606	dst->ip6po_flags = src->ip6po_flags;
2607	dst->ip6po_minmtu = src->ip6po_minmtu;
2608	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2609	if (src->ip6po_pktinfo) {
2610		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2611		    M_IP6OPT, canwait);
2612		if (dst->ip6po_pktinfo == NULL)
2613			goto bad;
2614		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2615	}
2616	if (src->ip6po_nexthop) {
2617		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2618		    M_IP6OPT, canwait);
2619		if (dst->ip6po_nexthop == NULL)
2620			goto bad;
2621		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2622		    src->ip6po_nexthop->sa_len);
2623	}
2624	PKTOPT_EXTHDRCPY(ip6po_hbh);
2625	PKTOPT_EXTHDRCPY(ip6po_dest1);
2626	PKTOPT_EXTHDRCPY(ip6po_dest2);
2627	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2628	return (0);
2629
2630  bad:
2631	ip6_clearpktopts(dst, -1);
2632	return (ENOBUFS);
2633}
2634#undef PKTOPT_EXTHDRCPY
2635
2636struct ip6_pktopts *
2637ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2638{
2639	int error;
2640	struct ip6_pktopts *dst;
2641
2642	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2643	if (dst == NULL)
2644		return (NULL);
2645	ip6_initpktopts(dst);
2646
2647	if ((error = copypktopts(dst, src, canwait)) != 0) {
2648		free(dst, M_IP6OPT);
2649		return (NULL);
2650	}
2651
2652	return (dst);
2653}
2654
2655void
2656ip6_freepcbopts(struct ip6_pktopts *pktopt)
2657{
2658	if (pktopt == NULL)
2659		return;
2660
2661	ip6_clearpktopts(pktopt, -1);
2662
2663	free(pktopt, M_IP6OPT);
2664}
2665
2666/*
2667 * Set IPv6 outgoing packet options based on advanced API.
2668 */
2669int
2670ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2671    struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2672{
2673	struct cmsghdr *cm = NULL;
2674
2675	if (control == NULL || opt == NULL)
2676		return (EINVAL);
2677
2678	ip6_initpktopts(opt);
2679	if (stickyopt) {
2680		int error;
2681
2682		/*
2683		 * If stickyopt is provided, make a local copy of the options
2684		 * for this particular packet, then override them by ancillary
2685		 * objects.
2686		 * XXX: copypktopts() does not copy the cached route to a next
2687		 * hop (if any).  This is not very good in terms of efficiency,
2688		 * but we can allow this since this option should be rarely
2689		 * used.
2690		 */
2691		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2692			return (error);
2693	}
2694
2695	/*
2696	 * XXX: Currently, we assume all the optional information is stored
2697	 * in a single mbuf.
2698	 */
2699	if (control->m_next)
2700		return (EINVAL);
2701
2702	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2703	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2704		int error;
2705
2706		if (control->m_len < CMSG_LEN(0))
2707			return (EINVAL);
2708
2709		cm = mtod(control, struct cmsghdr *);
2710		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2711			return (EINVAL);
2712		if (cm->cmsg_level != IPPROTO_IPV6)
2713			continue;
2714
2715		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2716		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2717		if (error)
2718			return (error);
2719	}
2720
2721	return (0);
2722}
2723
2724/*
2725 * Set a particular packet option, as a sticky option or an ancillary data
2726 * item.  "len" can be 0 only when it's a sticky option.
2727 * We have 4 cases of combination of "sticky" and "cmsg":
2728 * "sticky=0, cmsg=0": impossible
2729 * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2730 * "sticky=1, cmsg=0": RFC3542 socket option
2731 * "sticky=1, cmsg=1": RFC2292 socket option
2732 */
2733static int
2734ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2735    struct ucred *cred, int sticky, int cmsg, int uproto)
2736{
2737	int minmtupolicy, preftemp;
2738	int error;
2739
2740	if (!sticky && !cmsg) {
2741#ifdef DIAGNOSTIC
2742		printf("ip6_setpktopt: impossible case\n");
2743#endif
2744		return (EINVAL);
2745	}
2746
2747	/*
2748	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2749	 * not be specified in the context of RFC3542.  Conversely,
2750	 * RFC3542 types should not be specified in the context of RFC2292.
2751	 */
2752	if (!cmsg) {
2753		switch (optname) {
2754		case IPV6_2292PKTINFO:
2755		case IPV6_2292HOPLIMIT:
2756		case IPV6_2292NEXTHOP:
2757		case IPV6_2292HOPOPTS:
2758		case IPV6_2292DSTOPTS:
2759		case IPV6_2292RTHDR:
2760		case IPV6_2292PKTOPTIONS:
2761			return (ENOPROTOOPT);
2762		}
2763	}
2764	if (sticky && cmsg) {
2765		switch (optname) {
2766		case IPV6_PKTINFO:
2767		case IPV6_HOPLIMIT:
2768		case IPV6_NEXTHOP:
2769		case IPV6_HOPOPTS:
2770		case IPV6_DSTOPTS:
2771		case IPV6_RTHDRDSTOPTS:
2772		case IPV6_RTHDR:
2773		case IPV6_USE_MIN_MTU:
2774		case IPV6_DONTFRAG:
2775		case IPV6_TCLASS:
2776		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2777			return (ENOPROTOOPT);
2778		}
2779	}
2780
2781	switch (optname) {
2782	case IPV6_2292PKTINFO:
2783	case IPV6_PKTINFO:
2784	{
2785		struct ifnet *ifp = NULL;
2786		struct in6_pktinfo *pktinfo;
2787
2788		if (len != sizeof(struct in6_pktinfo))
2789			return (EINVAL);
2790
2791		pktinfo = (struct in6_pktinfo *)buf;
2792
2793		/*
2794		 * An application can clear any sticky IPV6_PKTINFO option by
2795		 * doing a "regular" setsockopt with ipi6_addr being
2796		 * in6addr_any and ipi6_ifindex being zero.
2797		 * [RFC 3542, Section 6]
2798		 */
2799		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2800		    pktinfo->ipi6_ifindex == 0 &&
2801		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2802			ip6_clearpktopts(opt, optname);
2803			break;
2804		}
2805
2806		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2807		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2808			return (EINVAL);
2809		}
2810		if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2811			return (EINVAL);
2812		/* validate the interface index if specified. */
2813		if (pktinfo->ipi6_ifindex > V_if_index)
2814			 return (ENXIO);
2815		if (pktinfo->ipi6_ifindex) {
2816			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2817			if (ifp == NULL)
2818				return (ENXIO);
2819		}
2820		if (ifp != NULL && (ifp->if_afdata[AF_INET6] == NULL ||
2821		    (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0))
2822			return (ENETDOWN);
2823
2824		if (ifp != NULL &&
2825		    !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2826			struct in6_ifaddr *ia;
2827
2828			in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2829			ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2830			if (ia == NULL)
2831				return (EADDRNOTAVAIL);
2832			ifa_free(&ia->ia_ifa);
2833		}
2834		/*
2835		 * We store the address anyway, and let in6_selectsrc()
2836		 * validate the specified address.  This is because ipi6_addr
2837		 * may not have enough information about its scope zone, and
2838		 * we may need additional information (such as outgoing
2839		 * interface or the scope zone of a destination address) to
2840		 * disambiguate the scope.
2841		 * XXX: the delay of the validation may confuse the
2842		 * application when it is used as a sticky option.
2843		 */
2844		if (opt->ip6po_pktinfo == NULL) {
2845			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2846			    M_IP6OPT, M_NOWAIT);
2847			if (opt->ip6po_pktinfo == NULL)
2848				return (ENOBUFS);
2849		}
2850		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2851		break;
2852	}
2853
2854	case IPV6_2292HOPLIMIT:
2855	case IPV6_HOPLIMIT:
2856	{
2857		int *hlimp;
2858
2859		/*
2860		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2861		 * to simplify the ordering among hoplimit options.
2862		 */
2863		if (optname == IPV6_HOPLIMIT && sticky)
2864			return (ENOPROTOOPT);
2865
2866		if (len != sizeof(int))
2867			return (EINVAL);
2868		hlimp = (int *)buf;
2869		if (*hlimp < -1 || *hlimp > 255)
2870			return (EINVAL);
2871
2872		opt->ip6po_hlim = *hlimp;
2873		break;
2874	}
2875
2876	case IPV6_TCLASS:
2877	{
2878		int tclass;
2879
2880		if (len != sizeof(int))
2881			return (EINVAL);
2882		tclass = *(int *)buf;
2883		if (tclass < -1 || tclass > 255)
2884			return (EINVAL);
2885
2886		opt->ip6po_tclass = tclass;
2887		break;
2888	}
2889
2890	case IPV6_2292NEXTHOP:
2891	case IPV6_NEXTHOP:
2892		if (cred != NULL) {
2893			error = priv_check_cred(cred,
2894			    PRIV_NETINET_SETHDROPTS, 0);
2895			if (error)
2896				return (error);
2897		}
2898
2899		if (len == 0) {	/* just remove the option */
2900			ip6_clearpktopts(opt, IPV6_NEXTHOP);
2901			break;
2902		}
2903
2904		/* check if cmsg_len is large enough for sa_len */
2905		if (len < sizeof(struct sockaddr) || len < *buf)
2906			return (EINVAL);
2907
2908		switch (((struct sockaddr *)buf)->sa_family) {
2909		case AF_INET6:
2910		{
2911			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2912			int error;
2913
2914			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2915				return (EINVAL);
2916
2917			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2918			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2919				return (EINVAL);
2920			}
2921			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2922			    != 0) {
2923				return (error);
2924			}
2925			break;
2926		}
2927		case AF_LINK:	/* should eventually be supported */
2928		default:
2929			return (EAFNOSUPPORT);
2930		}
2931
2932		/* turn off the previous option, then set the new option. */
2933		ip6_clearpktopts(opt, IPV6_NEXTHOP);
2934		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2935		if (opt->ip6po_nexthop == NULL)
2936			return (ENOBUFS);
2937		bcopy(buf, opt->ip6po_nexthop, *buf);
2938		break;
2939
2940	case IPV6_2292HOPOPTS:
2941	case IPV6_HOPOPTS:
2942	{
2943		struct ip6_hbh *hbh;
2944		int hbhlen;
2945
2946		/*
2947		 * XXX: We don't allow a non-privileged user to set ANY HbH
2948		 * options, since per-option restriction has too much
2949		 * overhead.
2950		 */
2951		if (cred != NULL) {
2952			error = priv_check_cred(cred,
2953			    PRIV_NETINET_SETHDROPTS, 0);
2954			if (error)
2955				return (error);
2956		}
2957
2958		if (len == 0) {
2959			ip6_clearpktopts(opt, IPV6_HOPOPTS);
2960			break;	/* just remove the option */
2961		}
2962
2963		/* message length validation */
2964		if (len < sizeof(struct ip6_hbh))
2965			return (EINVAL);
2966		hbh = (struct ip6_hbh *)buf;
2967		hbhlen = (hbh->ip6h_len + 1) << 3;
2968		if (len != hbhlen)
2969			return (EINVAL);
2970
2971		/* turn off the previous option, then set the new option. */
2972		ip6_clearpktopts(opt, IPV6_HOPOPTS);
2973		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2974		if (opt->ip6po_hbh == NULL)
2975			return (ENOBUFS);
2976		bcopy(hbh, opt->ip6po_hbh, hbhlen);
2977
2978		break;
2979	}
2980
2981	case IPV6_2292DSTOPTS:
2982	case IPV6_DSTOPTS:
2983	case IPV6_RTHDRDSTOPTS:
2984	{
2985		struct ip6_dest *dest, **newdest = NULL;
2986		int destlen;
2987
2988		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2989			error = priv_check_cred(cred,
2990			    PRIV_NETINET_SETHDROPTS, 0);
2991			if (error)
2992				return (error);
2993		}
2994
2995		if (len == 0) {
2996			ip6_clearpktopts(opt, optname);
2997			break;	/* just remove the option */
2998		}
2999
3000		/* message length validation */
3001		if (len < sizeof(struct ip6_dest))
3002			return (EINVAL);
3003		dest = (struct ip6_dest *)buf;
3004		destlen = (dest->ip6d_len + 1) << 3;
3005		if (len != destlen)
3006			return (EINVAL);
3007
3008		/*
3009		 * Determine the position that the destination options header
3010		 * should be inserted; before or after the routing header.
3011		 */
3012		switch (optname) {
3013		case IPV6_2292DSTOPTS:
3014			/*
3015			 * The old advacned API is ambiguous on this point.
3016			 * Our approach is to determine the position based
3017			 * according to the existence of a routing header.
3018			 * Note, however, that this depends on the order of the
3019			 * extension headers in the ancillary data; the 1st
3020			 * part of the destination options header must appear
3021			 * before the routing header in the ancillary data,
3022			 * too.
3023			 * RFC3542 solved the ambiguity by introducing
3024			 * separate ancillary data or option types.
3025			 */
3026			if (opt->ip6po_rthdr == NULL)
3027				newdest = &opt->ip6po_dest1;
3028			else
3029				newdest = &opt->ip6po_dest2;
3030			break;
3031		case IPV6_RTHDRDSTOPTS:
3032			newdest = &opt->ip6po_dest1;
3033			break;
3034		case IPV6_DSTOPTS:
3035			newdest = &opt->ip6po_dest2;
3036			break;
3037		}
3038
3039		/* turn off the previous option, then set the new option. */
3040		ip6_clearpktopts(opt, optname);
3041		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
3042		if (*newdest == NULL)
3043			return (ENOBUFS);
3044		bcopy(dest, *newdest, destlen);
3045
3046		break;
3047	}
3048
3049	case IPV6_2292RTHDR:
3050	case IPV6_RTHDR:
3051	{
3052		struct ip6_rthdr *rth;
3053		int rthlen;
3054
3055		if (len == 0) {
3056			ip6_clearpktopts(opt, IPV6_RTHDR);
3057			break;	/* just remove the option */
3058		}
3059
3060		/* message length validation */
3061		if (len < sizeof(struct ip6_rthdr))
3062			return (EINVAL);
3063		rth = (struct ip6_rthdr *)buf;
3064		rthlen = (rth->ip6r_len + 1) << 3;
3065		if (len != rthlen)
3066			return (EINVAL);
3067
3068		switch (rth->ip6r_type) {
3069		case IPV6_RTHDR_TYPE_0:
3070			if (rth->ip6r_len == 0)	/* must contain one addr */
3071				return (EINVAL);
3072			if (rth->ip6r_len % 2) /* length must be even */
3073				return (EINVAL);
3074			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
3075				return (EINVAL);
3076			break;
3077		default:
3078			return (EINVAL);	/* not supported */
3079		}
3080
3081		/* turn off the previous option */
3082		ip6_clearpktopts(opt, IPV6_RTHDR);
3083		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
3084		if (opt->ip6po_rthdr == NULL)
3085			return (ENOBUFS);
3086		bcopy(rth, opt->ip6po_rthdr, rthlen);
3087
3088		break;
3089	}
3090
3091	case IPV6_USE_MIN_MTU:
3092		if (len != sizeof(int))
3093			return (EINVAL);
3094		minmtupolicy = *(int *)buf;
3095		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3096		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
3097		    minmtupolicy != IP6PO_MINMTU_ALL) {
3098			return (EINVAL);
3099		}
3100		opt->ip6po_minmtu = minmtupolicy;
3101		break;
3102
3103	case IPV6_DONTFRAG:
3104		if (len != sizeof(int))
3105			return (EINVAL);
3106
3107		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3108			/*
3109			 * we ignore this option for TCP sockets.
3110			 * (RFC3542 leaves this case unspecified.)
3111			 */
3112			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3113		} else
3114			opt->ip6po_flags |= IP6PO_DONTFRAG;
3115		break;
3116
3117	case IPV6_PREFER_TEMPADDR:
3118		if (len != sizeof(int))
3119			return (EINVAL);
3120		preftemp = *(int *)buf;
3121		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3122		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3123		    preftemp != IP6PO_TEMPADDR_PREFER) {
3124			return (EINVAL);
3125		}
3126		opt->ip6po_prefer_tempaddr = preftemp;
3127		break;
3128
3129	default:
3130		return (ENOPROTOOPT);
3131	} /* end of switch */
3132
3133	return (0);
3134}
3135
3136/*
3137 * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3138 * packet to the input queue of a specified interface.  Note that this
3139 * calls the output routine of the loopback "driver", but with an interface
3140 * pointer that might NOT be &loif -- easier than replicating that code here.
3141 */
3142void
3143ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
3144{
3145	struct mbuf *copym;
3146	struct ip6_hdr *ip6;
3147
3148	copym = m_copym(m, 0, M_COPYALL, M_NOWAIT);
3149	if (copym == NULL)
3150		return;
3151
3152	/*
3153	 * Make sure to deep-copy IPv6 header portion in case the data
3154	 * is in an mbuf cluster, so that we can safely override the IPv6
3155	 * header portion later.
3156	 */
3157	if (!M_WRITABLE(copym) ||
3158	    copym->m_len < sizeof(struct ip6_hdr)) {
3159		copym = m_pullup(copym, sizeof(struct ip6_hdr));
3160		if (copym == NULL)
3161			return;
3162	}
3163	ip6 = mtod(copym, struct ip6_hdr *);
3164	/*
3165	 * clear embedded scope identifiers if necessary.
3166	 * in6_clearscope will touch the addresses only when necessary.
3167	 */
3168	in6_clearscope(&ip6->ip6_src);
3169	in6_clearscope(&ip6->ip6_dst);
3170	if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3171		copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3172		    CSUM_PSEUDO_HDR;
3173		copym->m_pkthdr.csum_data = 0xffff;
3174	}
3175	if_simloop(ifp, copym, AF_INET6, 0);
3176}
3177
3178/*
3179 * Chop IPv6 header off from the payload.
3180 */
3181static int
3182ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3183{
3184	struct mbuf *mh;
3185	struct ip6_hdr *ip6;
3186
3187	ip6 = mtod(m, struct ip6_hdr *);
3188	if (m->m_len > sizeof(*ip6)) {
3189		mh = m_gethdr(M_NOWAIT, MT_DATA);
3190		if (mh == NULL) {
3191			m_freem(m);
3192			return ENOBUFS;
3193		}
3194		m_move_pkthdr(mh, m);
3195		M_ALIGN(mh, sizeof(*ip6));
3196		m->m_len -= sizeof(*ip6);
3197		m->m_data += sizeof(*ip6);
3198		mh->m_next = m;
3199		m = mh;
3200		m->m_len = sizeof(*ip6);
3201		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3202	}
3203	exthdrs->ip6e_ip6 = m;
3204	return 0;
3205}
3206
3207/*
3208 * Compute IPv6 extension header length.
3209 */
3210int
3211ip6_optlen(struct inpcb *inp)
3212{
3213	int len;
3214
3215	if (!inp->in6p_outputopts)
3216		return 0;
3217
3218	len = 0;
3219#define elen(x) \
3220    (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3221
3222	len += elen(inp->in6p_outputopts->ip6po_hbh);
3223	if (inp->in6p_outputopts->ip6po_rthdr)
3224		/* dest1 is valid with rthdr only */
3225		len += elen(inp->in6p_outputopts->ip6po_dest1);
3226	len += elen(inp->in6p_outputopts->ip6po_rthdr);
3227	len += elen(inp->in6p_outputopts->ip6po_dest2);
3228	return len;
3229#undef elen
3230}
3231