1/*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
30 */
31
32/*-
33 * Copyright (c) 1982, 1986, 1988, 1990, 1993
34 *	The Regents of the University of California.  All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 *    notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 *    notice, this list of conditions and the following disclaimer in the
43 *    documentation and/or other materials provided with the distribution.
44 * 4. Neither the name of the University nor the names of its contributors
45 *    may be used to endorse or promote products derived from this software
46 *    without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
61 */
62
63#include <sys/cdefs.h>
64__FBSDID("$FreeBSD: releng/10.3/sys/netinet6/ip6_output.c 284572 2015-06-18 20:40:36Z kp $");
65
66#include "opt_inet.h"
67#include "opt_inet6.h"
68#include "opt_ipfw.h"
69#include "opt_ipsec.h"
70#include "opt_sctp.h"
71#include "opt_route.h"
72
73#include <sys/param.h>
74#include <sys/kernel.h>
75#include <sys/malloc.h>
76#include <sys/mbuf.h>
77#include <sys/errno.h>
78#include <sys/priv.h>
79#include <sys/proc.h>
80#include <sys/protosw.h>
81#include <sys/socket.h>
82#include <sys/socketvar.h>
83#include <sys/syslog.h>
84#include <sys/ucred.h>
85
86#include <machine/in_cksum.h>
87
88#include <net/if.h>
89#include <net/netisr.h>
90#include <net/route.h>
91#include <net/pfil.h>
92#include <net/vnet.h>
93
94#include <netinet/in.h>
95#include <netinet/in_var.h>
96#include <netinet/ip_var.h>
97#include <netinet6/in6_var.h>
98#include <netinet/ip6.h>
99#include <netinet/icmp6.h>
100#include <netinet6/ip6_var.h>
101#include <netinet/in_pcb.h>
102#include <netinet/tcp_var.h>
103#include <netinet6/nd6.h>
104
105#ifdef IPSEC
106#include <netipsec/ipsec.h>
107#include <netipsec/ipsec6.h>
108#include <netipsec/key.h>
109#include <netinet6/ip6_ipsec.h>
110#endif /* IPSEC */
111#ifdef SCTP
112#include <netinet/sctp.h>
113#include <netinet/sctp_crc32.h>
114#endif
115
116#include <netinet6/ip6protosw.h>
117#include <netinet6/scope6_var.h>
118
119#ifdef FLOWTABLE
120#include <net/flowtable.h>
121#endif
122
123extern int in6_mcast_loop;
124
125struct ip6_exthdrs {
126	struct mbuf *ip6e_ip6;
127	struct mbuf *ip6e_hbh;
128	struct mbuf *ip6e_dest1;
129	struct mbuf *ip6e_rthdr;
130	struct mbuf *ip6e_dest2;
131};
132
133static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
134			   struct ucred *, int);
135static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
136	struct socket *, struct sockopt *);
137static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
138static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
139	struct ucred *, int, int, int);
140
141static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
142static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
143	struct ip6_frag **);
144static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
145static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
146static int ip6_getpmtu(struct route_in6 *, struct route_in6 *,
147	struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
148static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
149
150
151/*
152 * Make an extension header from option data.  hp is the source, and
153 * mp is the destination.
154 */
155#define MAKE_EXTHDR(hp, mp)						\
156    do {								\
157	if (hp) {							\
158		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
159		error = ip6_copyexthdr((mp), (caddr_t)(hp),		\
160		    ((eh)->ip6e_len + 1) << 3);				\
161		if (error)						\
162			goto freehdrs;					\
163	}								\
164    } while (/*CONSTCOND*/ 0)
165
166/*
167 * Form a chain of extension headers.
168 * m is the extension header mbuf
169 * mp is the previous mbuf in the chain
170 * p is the next header
171 * i is the type of option.
172 */
173#define MAKE_CHAIN(m, mp, p, i)\
174    do {\
175	if (m) {\
176		if (!hdrsplit) \
177			panic("assumption failed: hdr not split"); \
178		*mtod((m), u_char *) = *(p);\
179		*(p) = (i);\
180		p = mtod((m), u_char *);\
181		(m)->m_next = (mp)->m_next;\
182		(mp)->m_next = (m);\
183		(mp) = (m);\
184	}\
185    } while (/*CONSTCOND*/ 0)
186
187void
188in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
189{
190	u_short csum;
191
192	csum = in_cksum_skip(m, offset + plen, offset);
193	if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
194		csum = 0xffff;
195	offset += m->m_pkthdr.csum_data;	/* checksum offset */
196
197	if (offset + sizeof(u_short) > m->m_len) {
198		printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
199		    "csum_flags=%b\n", __func__, m->m_len, plen, offset,
200		    (int)m->m_pkthdr.csum_flags, CSUM_BITS);
201		/*
202		 * XXX this should not happen, but if it does, the correct
203		 * behavior may be to insert the checksum in the appropriate
204		 * next mbuf in the chain.
205		 */
206		return;
207	}
208	*(u_short *)(m->m_data + offset) = csum;
209}
210
211int
212ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
213    int mtu, uint32_t id)
214{
215	struct mbuf *m, **mnext, *m_frgpart;
216	struct ip6_hdr *ip6, *mhip6;
217	struct ip6_frag *ip6f;
218	int off;
219	int error;
220	int tlen = m0->m_pkthdr.len;
221
222	m = m0;
223	ip6 = mtod(m, struct ip6_hdr *);
224	mnext = &m->m_nextpkt;
225
226	for (off = hlen; off < tlen; off += mtu) {
227		m = m_gethdr(M_NOWAIT, MT_DATA);
228		if (!m) {
229			IP6STAT_INC(ip6s_odropped);
230			return (ENOBUFS);
231		}
232		m->m_flags = m0->m_flags & M_COPYFLAGS;
233		*mnext = m;
234		mnext = &m->m_nextpkt;
235		m->m_data += max_linkhdr;
236		mhip6 = mtod(m, struct ip6_hdr *);
237		*mhip6 = *ip6;
238		m->m_len = sizeof(*mhip6);
239		error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
240		if (error) {
241			IP6STAT_INC(ip6s_odropped);
242			return (error);
243		}
244		ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
245		if (off + mtu >= tlen)
246			mtu = tlen - off;
247		else
248			ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
249		mhip6->ip6_plen = htons((u_short)(mtu + hlen +
250		    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
251		if ((m_frgpart = m_copy(m0, off, mtu)) == 0) {
252			IP6STAT_INC(ip6s_odropped);
253			return (ENOBUFS);
254		}
255		m_cat(m, m_frgpart);
256		m->m_pkthdr.len = mtu + hlen + sizeof(*ip6f);
257		m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
258		m->m_pkthdr.rcvif = NULL;
259		ip6f->ip6f_reserved = 0;
260		ip6f->ip6f_ident = id;
261		ip6f->ip6f_nxt = nextproto;
262		IP6STAT_INC(ip6s_ofragments);
263		in6_ifstat_inc(ifp, ifs6_out_fragcreat);
264	}
265
266	return (0);
267}
268
269/*
270 * IP6 output. The packet in mbuf chain m contains a skeletal IP6
271 * header (with pri, len, nxt, hlim, src, dst).
272 * This function may modify ver and hlim only.
273 * The mbuf chain containing the packet will be freed.
274 * The mbuf opt, if present, will not be freed.
275 * If route_in6 ro is present and has ro_rt initialized, route lookup would be
276 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
277 * then result of route lookup is stored in ro->ro_rt.
278 *
279 * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
280 * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
281 * which is rt_mtu.
282 *
283 * ifpp - XXX: just for statistics
284 */
285int
286ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
287    struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
288    struct ifnet **ifpp, struct inpcb *inp)
289{
290	struct ip6_hdr *ip6;
291	struct ifnet *ifp, *origifp;
292	struct mbuf *m = m0;
293	struct mbuf *mprev = NULL;
294	int hlen, tlen, len;
295	struct route_in6 ip6route;
296	struct rtentry *rt = NULL;
297	struct sockaddr_in6 *dst, src_sa, dst_sa;
298	struct in6_addr odst;
299	int error = 0;
300	struct in6_ifaddr *ia = NULL;
301	u_long mtu;
302	int alwaysfrag, dontfrag;
303	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
304	struct ip6_exthdrs exthdrs;
305	struct in6_addr finaldst, src0, dst0;
306	u_int32_t zone;
307	struct route_in6 *ro_pmtu = NULL;
308	int hdrsplit = 0;
309	int sw_csum, tso;
310	struct m_tag *fwd_tag = NULL;
311	uint32_t id;
312
313	ip6 = mtod(m, struct ip6_hdr *);
314	if (ip6 == NULL) {
315		printf ("ip6 is NULL");
316		goto bad;
317	}
318
319	if (inp != NULL)
320		M_SETFIB(m, inp->inp_inc.inc_fibnum);
321
322	finaldst = ip6->ip6_dst;
323	bzero(&exthdrs, sizeof(exthdrs));
324	if (opt) {
325		/* Hop-by-Hop options header */
326		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
327		/* Destination options header(1st part) */
328		if (opt->ip6po_rthdr) {
329			/*
330			 * Destination options header(1st part)
331			 * This only makes sense with a routing header.
332			 * See Section 9.2 of RFC 3542.
333			 * Disabling this part just for MIP6 convenience is
334			 * a bad idea.  We need to think carefully about a
335			 * way to make the advanced API coexist with MIP6
336			 * options, which might automatically be inserted in
337			 * the kernel.
338			 */
339			MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
340		}
341		/* Routing header */
342		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
343		/* Destination options header(2nd part) */
344		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
345	}
346
347#ifdef IPSEC
348	/*
349	 * IPSec checking which handles several cases.
350	 * FAST IPSEC: We re-injected the packet.
351	 */
352	switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp))
353	{
354	case 1:                 /* Bad packet */
355		goto freehdrs;
356	case -1:                /* IPSec done */
357		goto done;
358	case 0:                 /* No IPSec */
359	default:
360		break;
361	}
362#endif /* IPSEC */
363
364	/*
365	 * Calculate the total length of the extension header chain.
366	 * Keep the length of the unfragmentable part for fragmentation.
367	 */
368	optlen = 0;
369	if (exthdrs.ip6e_hbh)
370		optlen += exthdrs.ip6e_hbh->m_len;
371	if (exthdrs.ip6e_dest1)
372		optlen += exthdrs.ip6e_dest1->m_len;
373	if (exthdrs.ip6e_rthdr)
374		optlen += exthdrs.ip6e_rthdr->m_len;
375	unfragpartlen = optlen + sizeof(struct ip6_hdr);
376
377	/* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
378	if (exthdrs.ip6e_dest2)
379		optlen += exthdrs.ip6e_dest2->m_len;
380
381	/*
382	 * If there is at least one extension header,
383	 * separate IP6 header from the payload.
384	 */
385	if (optlen && !hdrsplit) {
386		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
387			m = NULL;
388			goto freehdrs;
389		}
390		m = exthdrs.ip6e_ip6;
391		hdrsplit++;
392	}
393
394	/* adjust pointer */
395	ip6 = mtod(m, struct ip6_hdr *);
396
397	/* adjust mbuf packet header length */
398	m->m_pkthdr.len += optlen;
399	plen = m->m_pkthdr.len - sizeof(*ip6);
400
401	/* If this is a jumbo payload, insert a jumbo payload option. */
402	if (plen > IPV6_MAXPACKET) {
403		if (!hdrsplit) {
404			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
405				m = NULL;
406				goto freehdrs;
407			}
408			m = exthdrs.ip6e_ip6;
409			hdrsplit++;
410		}
411		/* adjust pointer */
412		ip6 = mtod(m, struct ip6_hdr *);
413		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
414			goto freehdrs;
415		ip6->ip6_plen = 0;
416	} else
417		ip6->ip6_plen = htons(plen);
418
419	/*
420	 * Concatenate headers and fill in next header fields.
421	 * Here we have, on "m"
422	 *	IPv6 payload
423	 * and we insert headers accordingly.  Finally, we should be getting:
424	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
425	 *
426	 * during the header composing process, "m" points to IPv6 header.
427	 * "mprev" points to an extension header prior to esp.
428	 */
429	u_char *nexthdrp = &ip6->ip6_nxt;
430	mprev = m;
431
432	/*
433	 * we treat dest2 specially.  this makes IPsec processing
434	 * much easier.  the goal here is to make mprev point the
435	 * mbuf prior to dest2.
436	 *
437	 * result: IPv6 dest2 payload
438	 * m and mprev will point to IPv6 header.
439	 */
440	if (exthdrs.ip6e_dest2) {
441		if (!hdrsplit)
442			panic("assumption failed: hdr not split");
443		exthdrs.ip6e_dest2->m_next = m->m_next;
444		m->m_next = exthdrs.ip6e_dest2;
445		*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
446		ip6->ip6_nxt = IPPROTO_DSTOPTS;
447	}
448
449	/*
450	 * result: IPv6 hbh dest1 rthdr dest2 payload
451	 * m will point to IPv6 header.  mprev will point to the
452	 * extension header prior to dest2 (rthdr in the above case).
453	 */
454	MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
455	MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
456		   IPPROTO_DSTOPTS);
457	MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
458		   IPPROTO_ROUTING);
459
460	/*
461	 * If there is a routing header, discard the packet.
462	 */
463	if (exthdrs.ip6e_rthdr) {
464		 error = EINVAL;
465		 goto bad;
466	}
467
468	/* Source address validation */
469	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
470	    (flags & IPV6_UNSPECSRC) == 0) {
471		error = EOPNOTSUPP;
472		IP6STAT_INC(ip6s_badscope);
473		goto bad;
474	}
475	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
476		error = EOPNOTSUPP;
477		IP6STAT_INC(ip6s_badscope);
478		goto bad;
479	}
480
481	IP6STAT_INC(ip6s_localout);
482
483	/*
484	 * Route packet.
485	 */
486	if (ro == 0) {
487		ro = &ip6route;
488		bzero((caddr_t)ro, sizeof(*ro));
489	}
490	ro_pmtu = ro;
491	if (opt && opt->ip6po_rthdr)
492		ro = &opt->ip6po_route;
493	dst = (struct sockaddr_in6 *)&ro->ro_dst;
494#ifdef FLOWTABLE
495	if (ro->ro_rt == NULL)
496		(void )flowtable_lookup(AF_INET6, m, (struct route *)ro);
497#endif
498again:
499	/*
500	 * if specified, try to fill in the traffic class field.
501	 * do not override if a non-zero value is already set.
502	 * we check the diffserv field and the ecn field separately.
503	 */
504	if (opt && opt->ip6po_tclass >= 0) {
505		int mask = 0;
506
507		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
508			mask |= 0xfc;
509		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
510			mask |= 0x03;
511		if (mask != 0)
512			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
513	}
514
515	/* fill in or override the hop limit field, if necessary. */
516	if (opt && opt->ip6po_hlim != -1)
517		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
518	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
519		if (im6o != NULL)
520			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
521		else
522			ip6->ip6_hlim = V_ip6_defmcasthlim;
523	}
524
525	/* adjust pointer */
526	ip6 = mtod(m, struct ip6_hdr *);
527
528	if (ro->ro_rt && fwd_tag == NULL) {
529		rt = ro->ro_rt;
530		ifp = ro->ro_rt->rt_ifp;
531	} else {
532		if (fwd_tag == NULL) {
533			bzero(&dst_sa, sizeof(dst_sa));
534			dst_sa.sin6_family = AF_INET6;
535			dst_sa.sin6_len = sizeof(dst_sa);
536			dst_sa.sin6_addr = ip6->ip6_dst;
537		}
538		error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
539		    &rt, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
540		if (error != 0) {
541			if (ifp != NULL)
542				in6_ifstat_inc(ifp, ifs6_out_discard);
543			goto bad;
544		}
545	}
546	if (rt == NULL) {
547		/*
548		 * If in6_selectroute() does not return a route entry,
549		 * dst may not have been updated.
550		 */
551		*dst = dst_sa;	/* XXX */
552	}
553
554	/*
555	 * then rt (for unicast) and ifp must be non-NULL valid values.
556	 */
557	if ((flags & IPV6_FORWARDING) == 0) {
558		/* XXX: the FORWARDING flag can be set for mrouting. */
559		in6_ifstat_inc(ifp, ifs6_out_request);
560	}
561	if (rt != NULL) {
562		ia = (struct in6_ifaddr *)(rt->rt_ifa);
563		counter_u64_add(rt->rt_pksent, 1);
564	}
565
566
567	/*
568	 * The outgoing interface must be in the zone of source and
569	 * destination addresses.
570	 */
571	origifp = ifp;
572
573	src0 = ip6->ip6_src;
574	if (in6_setscope(&src0, origifp, &zone))
575		goto badscope;
576	bzero(&src_sa, sizeof(src_sa));
577	src_sa.sin6_family = AF_INET6;
578	src_sa.sin6_len = sizeof(src_sa);
579	src_sa.sin6_addr = ip6->ip6_src;
580	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
581		goto badscope;
582
583	dst0 = ip6->ip6_dst;
584	if (in6_setscope(&dst0, origifp, &zone))
585		goto badscope;
586	/* re-initialize to be sure */
587	bzero(&dst_sa, sizeof(dst_sa));
588	dst_sa.sin6_family = AF_INET6;
589	dst_sa.sin6_len = sizeof(dst_sa);
590	dst_sa.sin6_addr = ip6->ip6_dst;
591	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
592		goto badscope;
593	}
594
595	/* We should use ia_ifp to support the case of
596	 * sending packets to an address of our own.
597	 */
598	if (ia != NULL && ia->ia_ifp)
599		ifp = ia->ia_ifp;
600
601	/* scope check is done. */
602	goto routefound;
603
604  badscope:
605	IP6STAT_INC(ip6s_badscope);
606	in6_ifstat_inc(origifp, ifs6_out_discard);
607	if (error == 0)
608		error = EHOSTUNREACH; /* XXX */
609	goto bad;
610
611  routefound:
612	if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
613		if (opt && opt->ip6po_nextroute.ro_rt) {
614			/*
615			 * The nexthop is explicitly specified by the
616			 * application.  We assume the next hop is an IPv6
617			 * address.
618			 */
619			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
620		}
621		else if ((rt->rt_flags & RTF_GATEWAY))
622			dst = (struct sockaddr_in6 *)rt->rt_gateway;
623	}
624
625	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
626		m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
627	} else {
628		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
629		in6_ifstat_inc(ifp, ifs6_out_mcast);
630		/*
631		 * Confirm that the outgoing interface supports multicast.
632		 */
633		if (!(ifp->if_flags & IFF_MULTICAST)) {
634			IP6STAT_INC(ip6s_noroute);
635			in6_ifstat_inc(ifp, ifs6_out_discard);
636			error = ENETUNREACH;
637			goto bad;
638		}
639		if ((im6o == NULL && in6_mcast_loop) ||
640		    (im6o && im6o->im6o_multicast_loop)) {
641			/*
642			 * Loop back multicast datagram if not expressly
643			 * forbidden to do so, even if we have not joined
644			 * the address; protocols will filter it later,
645			 * thus deferring a hash lookup and lock acquisition
646			 * at the expense of an m_copym().
647			 */
648			ip6_mloopback(ifp, m, dst);
649		} else {
650			/*
651			 * If we are acting as a multicast router, perform
652			 * multicast forwarding as if the packet had just
653			 * arrived on the interface to which we are about
654			 * to send.  The multicast forwarding function
655			 * recursively calls this function, using the
656			 * IPV6_FORWARDING flag to prevent infinite recursion.
657			 *
658			 * Multicasts that are looped back by ip6_mloopback(),
659			 * above, will be forwarded by the ip6_input() routine,
660			 * if necessary.
661			 */
662			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
663				/*
664				 * XXX: ip6_mforward expects that rcvif is NULL
665				 * when it is called from the originating path.
666				 * However, it may not always be the case.
667				 */
668				m->m_pkthdr.rcvif = NULL;
669				if (ip6_mforward(ip6, ifp, m) != 0) {
670					m_freem(m);
671					goto done;
672				}
673			}
674		}
675		/*
676		 * Multicasts with a hoplimit of zero may be looped back,
677		 * above, but must not be transmitted on a network.
678		 * Also, multicasts addressed to the loopback interface
679		 * are not sent -- the above call to ip6_mloopback() will
680		 * loop back a copy if this host actually belongs to the
681		 * destination group on the loopback interface.
682		 */
683		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
684		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
685			m_freem(m);
686			goto done;
687		}
688	}
689
690	/*
691	 * Fill the outgoing inteface to tell the upper layer
692	 * to increment per-interface statistics.
693	 */
694	if (ifpp)
695		*ifpp = ifp;
696
697	/* Determine path MTU. */
698	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
699	    &alwaysfrag, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m))) != 0)
700		goto bad;
701
702	/*
703	 * The caller of this function may specify to use the minimum MTU
704	 * in some cases.
705	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
706	 * setting.  The logic is a bit complicated; by default, unicast
707	 * packets will follow path MTU while multicast packets will be sent at
708	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
709	 * including unicast ones will be sent at the minimum MTU.  Multicast
710	 * packets will always be sent at the minimum MTU unless
711	 * IP6PO_MINMTU_DISABLE is explicitly specified.
712	 * See RFC 3542 for more details.
713	 */
714	if (mtu > IPV6_MMTU) {
715		if ((flags & IPV6_MINMTU))
716			mtu = IPV6_MMTU;
717		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
718			mtu = IPV6_MMTU;
719		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
720			 (opt == NULL ||
721			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
722			mtu = IPV6_MMTU;
723		}
724	}
725
726	/*
727	 * clear embedded scope identifiers if necessary.
728	 * in6_clearscope will touch the addresses only when necessary.
729	 */
730	in6_clearscope(&ip6->ip6_src);
731	in6_clearscope(&ip6->ip6_dst);
732
733	/*
734	 * If the outgoing packet contains a hop-by-hop options header,
735	 * it must be examined and processed even by the source node.
736	 * (RFC 2460, section 4.)
737	 */
738	if (exthdrs.ip6e_hbh) {
739		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
740		u_int32_t dummy; /* XXX unused */
741		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
742
743#ifdef DIAGNOSTIC
744		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
745			panic("ip6e_hbh is not contiguous");
746#endif
747		/*
748		 *  XXX: if we have to send an ICMPv6 error to the sender,
749		 *       we need the M_LOOP flag since icmp6_error() expects
750		 *       the IPv6 and the hop-by-hop options header are
751		 *       contiguous unless the flag is set.
752		 */
753		m->m_flags |= M_LOOP;
754		m->m_pkthdr.rcvif = ifp;
755		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
756		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
757		    &dummy, &plen) < 0) {
758			/* m was already freed at this point */
759			error = EINVAL;/* better error? */
760			goto done;
761		}
762		m->m_flags &= ~M_LOOP; /* XXX */
763		m->m_pkthdr.rcvif = NULL;
764	}
765
766	/* Jump over all PFIL processing if hooks are not active. */
767	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
768		goto passout;
769
770	odst = ip6->ip6_dst;
771	/* Run through list of hooks for output packets. */
772	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
773	if (error != 0 || m == NULL)
774		goto done;
775	ip6 = mtod(m, struct ip6_hdr *);
776
777	/* See if destination IP address was changed by packet filter. */
778	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
779		m->m_flags |= M_SKIP_FIREWALL;
780		/* If destination is now ourself drop to ip6_input(). */
781		if (in6_localip(&ip6->ip6_dst)) {
782			m->m_flags |= M_FASTFWD_OURS;
783			if (m->m_pkthdr.rcvif == NULL)
784				m->m_pkthdr.rcvif = V_loif;
785			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
786				m->m_pkthdr.csum_flags |=
787				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
788				m->m_pkthdr.csum_data = 0xffff;
789			}
790#ifdef SCTP
791			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
792				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
793#endif
794			error = netisr_queue(NETISR_IPV6, m);
795			goto done;
796		} else
797			goto again;	/* Redo the routing table lookup. */
798	}
799
800	/* See if local, if yes, send it to netisr. */
801	if (m->m_flags & M_FASTFWD_OURS) {
802		if (m->m_pkthdr.rcvif == NULL)
803			m->m_pkthdr.rcvif = V_loif;
804		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
805			m->m_pkthdr.csum_flags |=
806			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
807			m->m_pkthdr.csum_data = 0xffff;
808		}
809#ifdef SCTP
810		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
811			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
812#endif
813		error = netisr_queue(NETISR_IPV6, m);
814		goto done;
815	}
816	/* Or forward to some other address? */
817	if ((m->m_flags & M_IP6_NEXTHOP) &&
818	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
819		dst = (struct sockaddr_in6 *)&ro->ro_dst;
820		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
821		m->m_flags |= M_SKIP_FIREWALL;
822		m->m_flags &= ~M_IP6_NEXTHOP;
823		m_tag_delete(m, fwd_tag);
824		goto again;
825	}
826
827passout:
828	/*
829	 * Send the packet to the outgoing interface.
830	 * If necessary, do IPv6 fragmentation before sending.
831	 *
832	 * the logic here is rather complex:
833	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
834	 * 1-a:	send as is if tlen <= path mtu
835	 * 1-b:	fragment if tlen > path mtu
836	 *
837	 * 2: if user asks us not to fragment (dontfrag == 1)
838	 * 2-a:	send as is if tlen <= interface mtu
839	 * 2-b:	error if tlen > interface mtu
840	 *
841	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
842	 *	always fragment
843	 *
844	 * 4: if dontfrag == 1 && alwaysfrag == 1
845	 *	error, as we cannot handle this conflicting request
846	 */
847	sw_csum = m->m_pkthdr.csum_flags;
848	if (!hdrsplit) {
849		tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
850		sw_csum &= ~ifp->if_hwassist;
851	} else
852		tso = 0;
853	/*
854	 * If we added extension headers, we will not do TSO and calculate the
855	 * checksums ourselves for now.
856	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
857	 * with ext. hdrs.
858	 */
859	if (sw_csum & CSUM_DELAY_DATA_IPV6) {
860		sw_csum &= ~CSUM_DELAY_DATA_IPV6;
861		in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
862	}
863#ifdef SCTP
864	if (sw_csum & CSUM_SCTP_IPV6) {
865		sw_csum &= ~CSUM_SCTP_IPV6;
866		sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
867	}
868#endif
869	m->m_pkthdr.csum_flags &= ifp->if_hwassist;
870	tlen = m->m_pkthdr.len;
871
872	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
873		dontfrag = 1;
874	else
875		dontfrag = 0;
876	if (dontfrag && alwaysfrag) {	/* case 4 */
877		/* conflicting request - can't transmit */
878		error = EMSGSIZE;
879		goto bad;
880	}
881	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* case 2-b */
882		/*
883		 * Even if the DONTFRAG option is specified, we cannot send the
884		 * packet when the data length is larger than the MTU of the
885		 * outgoing interface.
886		 * Notify the error by sending IPV6_PATHMTU ancillary data if
887		 * application wanted to know the MTU value. Also return an
888		 * error code (this is not described in the API spec).
889		 */
890		if (inp != NULL)
891			ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
892		error = EMSGSIZE;
893		goto bad;
894	}
895
896	/*
897	 * transmit packet without fragmentation
898	 */
899	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* case 1-a and 2-a */
900		struct in6_ifaddr *ia6;
901
902		ip6 = mtod(m, struct ip6_hdr *);
903		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
904		if (ia6) {
905			/* Record statistics for this interface address. */
906			ia6->ia_ifa.if_opackets++;
907			ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
908			ifa_free(&ia6->ia_ifa);
909		}
910		error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
911		goto done;
912	}
913
914	/*
915	 * try to fragment the packet.  case 1-b and 3
916	 */
917	if (mtu < IPV6_MMTU) {
918		/* path MTU cannot be less than IPV6_MMTU */
919		error = EMSGSIZE;
920		in6_ifstat_inc(ifp, ifs6_out_fragfail);
921		goto bad;
922	} else if (ip6->ip6_plen == 0) {
923		/* jumbo payload cannot be fragmented */
924		error = EMSGSIZE;
925		in6_ifstat_inc(ifp, ifs6_out_fragfail);
926		goto bad;
927	} else {
928		u_char nextproto;
929
930		int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
931
932		/*
933		 * Too large for the destination or interface;
934		 * fragment if possible.
935		 * Must be able to put at least 8 bytes per fragment.
936		 */
937		hlen = unfragpartlen;
938		if (mtu > IPV6_MAXPACKET)
939			mtu = IPV6_MAXPACKET;
940
941		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
942		if (len < 8) {
943			error = EMSGSIZE;
944			in6_ifstat_inc(ifp, ifs6_out_fragfail);
945			goto bad;
946		}
947
948		/*
949		 * Verify that we have any chance at all of being able to queue
950		 *      the packet or packet fragments
951		 */
952		if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
953		    < tlen  /* - hlen */)) {
954			error = ENOBUFS;
955			IP6STAT_INC(ip6s_odropped);
956			goto bad;
957		}
958
959
960		/*
961		 * If the interface will not calculate checksums on
962		 * fragmented packets, then do it here.
963		 * XXX-BZ handle the hw offloading case.  Need flags.
964		 */
965		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
966			in6_delayed_cksum(m, plen, hlen);
967			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
968		}
969#ifdef SCTP
970		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
971			sctp_delayed_cksum(m, hlen);
972			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
973		}
974#endif
975		/*
976		 * Change the next header field of the last header in the
977		 * unfragmentable part.
978		 */
979		if (exthdrs.ip6e_rthdr) {
980			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
981			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
982		} else if (exthdrs.ip6e_dest1) {
983			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
984			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
985		} else if (exthdrs.ip6e_hbh) {
986			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
987			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
988		} else {
989			nextproto = ip6->ip6_nxt;
990			ip6->ip6_nxt = IPPROTO_FRAGMENT;
991		}
992
993		/*
994		 * Loop through length of segment after first fragment,
995		 * make new header and copy data of each part and link onto
996		 * chain.
997		 */
998		m0 = m;
999		id = htonl(ip6_randomid());
1000		if ((error = ip6_fragment(ifp, m, hlen, nextproto, len, id)))
1001			goto sendorfree;
1002
1003		in6_ifstat_inc(ifp, ifs6_out_fragok);
1004	}
1005
1006	/*
1007	 * Remove leading garbages.
1008	 */
1009sendorfree:
1010	m = m0->m_nextpkt;
1011	m0->m_nextpkt = 0;
1012	m_freem(m0);
1013	for (m0 = m; m; m = m0) {
1014		m0 = m->m_nextpkt;
1015		m->m_nextpkt = 0;
1016		if (error == 0) {
1017			/* Record statistics for this interface address. */
1018			if (ia) {
1019				ia->ia_ifa.if_opackets++;
1020				ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1021			}
1022			error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1023		} else
1024			m_freem(m);
1025	}
1026
1027	if (error == 0)
1028		IP6STAT_INC(ip6s_fragmented);
1029
1030done:
1031	if (ro == &ip6route)
1032		RO_RTFREE(ro);
1033	if (ro_pmtu == &ip6route)
1034		RO_RTFREE(ro_pmtu);
1035	return (error);
1036
1037freehdrs:
1038	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
1039	m_freem(exthdrs.ip6e_dest1);
1040	m_freem(exthdrs.ip6e_rthdr);
1041	m_freem(exthdrs.ip6e_dest2);
1042	/* FALLTHROUGH */
1043bad:
1044	if (m)
1045		m_freem(m);
1046	goto done;
1047}
1048
1049static int
1050ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1051{
1052	struct mbuf *m;
1053
1054	if (hlen > MCLBYTES)
1055		return (ENOBUFS); /* XXX */
1056
1057	if (hlen > MLEN)
1058		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1059	else
1060		m = m_get(M_NOWAIT, MT_DATA);
1061	if (m == NULL)
1062		return (ENOBUFS);
1063	m->m_len = hlen;
1064	if (hdr)
1065		bcopy(hdr, mtod(m, caddr_t), hlen);
1066
1067	*mp = m;
1068	return (0);
1069}
1070
1071/*
1072 * Insert jumbo payload option.
1073 */
1074static int
1075ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1076{
1077	struct mbuf *mopt;
1078	u_char *optbuf;
1079	u_int32_t v;
1080
1081#define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1082
1083	/*
1084	 * If there is no hop-by-hop options header, allocate new one.
1085	 * If there is one but it doesn't have enough space to store the
1086	 * jumbo payload option, allocate a cluster to store the whole options.
1087	 * Otherwise, use it to store the options.
1088	 */
1089	if (exthdrs->ip6e_hbh == 0) {
1090		mopt = m_get(M_NOWAIT, MT_DATA);
1091		if (mopt == NULL)
1092			return (ENOBUFS);
1093		mopt->m_len = JUMBOOPTLEN;
1094		optbuf = mtod(mopt, u_char *);
1095		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1096		exthdrs->ip6e_hbh = mopt;
1097	} else {
1098		struct ip6_hbh *hbh;
1099
1100		mopt = exthdrs->ip6e_hbh;
1101		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1102			/*
1103			 * XXX assumption:
1104			 * - exthdrs->ip6e_hbh is not referenced from places
1105			 *   other than exthdrs.
1106			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1107			 */
1108			int oldoptlen = mopt->m_len;
1109			struct mbuf *n;
1110
1111			/*
1112			 * XXX: give up if the whole (new) hbh header does
1113			 * not fit even in an mbuf cluster.
1114			 */
1115			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1116				return (ENOBUFS);
1117
1118			/*
1119			 * As a consequence, we must always prepare a cluster
1120			 * at this point.
1121			 */
1122			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1123			if (n == NULL)
1124				return (ENOBUFS);
1125			n->m_len = oldoptlen + JUMBOOPTLEN;
1126			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1127			    oldoptlen);
1128			optbuf = mtod(n, caddr_t) + oldoptlen;
1129			m_freem(mopt);
1130			mopt = exthdrs->ip6e_hbh = n;
1131		} else {
1132			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1133			mopt->m_len += JUMBOOPTLEN;
1134		}
1135		optbuf[0] = IP6OPT_PADN;
1136		optbuf[1] = 1;
1137
1138		/*
1139		 * Adjust the header length according to the pad and
1140		 * the jumbo payload option.
1141		 */
1142		hbh = mtod(mopt, struct ip6_hbh *);
1143		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1144	}
1145
1146	/* fill in the option. */
1147	optbuf[2] = IP6OPT_JUMBO;
1148	optbuf[3] = 4;
1149	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1150	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1151
1152	/* finally, adjust the packet header length */
1153	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1154
1155	return (0);
1156#undef JUMBOOPTLEN
1157}
1158
1159/*
1160 * Insert fragment header and copy unfragmentable header portions.
1161 */
1162static int
1163ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1164    struct ip6_frag **frghdrp)
1165{
1166	struct mbuf *n, *mlast;
1167
1168	if (hlen > sizeof(struct ip6_hdr)) {
1169		n = m_copym(m0, sizeof(struct ip6_hdr),
1170		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1171		if (n == 0)
1172			return (ENOBUFS);
1173		m->m_next = n;
1174	} else
1175		n = m;
1176
1177	/* Search for the last mbuf of unfragmentable part. */
1178	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1179		;
1180
1181	if ((mlast->m_flags & M_EXT) == 0 &&
1182	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1183		/* use the trailing space of the last mbuf for the fragment hdr */
1184		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1185		    mlast->m_len);
1186		mlast->m_len += sizeof(struct ip6_frag);
1187		m->m_pkthdr.len += sizeof(struct ip6_frag);
1188	} else {
1189		/* allocate a new mbuf for the fragment header */
1190		struct mbuf *mfrg;
1191
1192		mfrg = m_get(M_NOWAIT, MT_DATA);
1193		if (mfrg == NULL)
1194			return (ENOBUFS);
1195		mfrg->m_len = sizeof(struct ip6_frag);
1196		*frghdrp = mtod(mfrg, struct ip6_frag *);
1197		mlast->m_next = mfrg;
1198	}
1199
1200	return (0);
1201}
1202
1203static int
1204ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1205    struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1206    int *alwaysfragp, u_int fibnum)
1207{
1208	u_int32_t mtu = 0;
1209	int alwaysfrag = 0;
1210	int error = 0;
1211
1212	if (ro_pmtu != ro) {
1213		/* The first hop and the final destination may differ. */
1214		struct sockaddr_in6 *sa6_dst =
1215		    (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1216		if (ro_pmtu->ro_rt &&
1217		    ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1218		     !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1219			RTFREE(ro_pmtu->ro_rt);
1220			ro_pmtu->ro_rt = (struct rtentry *)NULL;
1221		}
1222		if (ro_pmtu->ro_rt == NULL) {
1223			bzero(sa6_dst, sizeof(*sa6_dst));
1224			sa6_dst->sin6_family = AF_INET6;
1225			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1226			sa6_dst->sin6_addr = *dst;
1227
1228			in6_rtalloc(ro_pmtu, fibnum);
1229		}
1230	}
1231	if (ro_pmtu->ro_rt) {
1232		u_int32_t ifmtu;
1233		struct in_conninfo inc;
1234
1235		bzero(&inc, sizeof(inc));
1236		inc.inc_flags |= INC_ISIPV6;
1237		inc.inc6_faddr = *dst;
1238
1239		if (ifp == NULL)
1240			ifp = ro_pmtu->ro_rt->rt_ifp;
1241		ifmtu = IN6_LINKMTU(ifp);
1242		mtu = tcp_hc_getmtu(&inc);
1243		if (mtu)
1244			mtu = min(mtu, ro_pmtu->ro_rt->rt_mtu);
1245		else
1246			mtu = ro_pmtu->ro_rt->rt_mtu;
1247		if (mtu == 0)
1248			mtu = ifmtu;
1249		else if (mtu < IPV6_MMTU) {
1250			/*
1251			 * RFC2460 section 5, last paragraph:
1252			 * if we record ICMPv6 too big message with
1253			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1254			 * or smaller, with framgent header attached.
1255			 * (fragment header is needed regardless from the
1256			 * packet size, for translators to identify packets)
1257			 */
1258			alwaysfrag = 1;
1259			mtu = IPV6_MMTU;
1260		} else if (mtu > ifmtu) {
1261			/*
1262			 * The MTU on the route is larger than the MTU on
1263			 * the interface!  This shouldn't happen, unless the
1264			 * MTU of the interface has been changed after the
1265			 * interface was brought up.  Change the MTU in the
1266			 * route to match the interface MTU (as long as the
1267			 * field isn't locked).
1268			 */
1269			mtu = ifmtu;
1270			ro_pmtu->ro_rt->rt_mtu = mtu;
1271		}
1272	} else if (ifp) {
1273		mtu = IN6_LINKMTU(ifp);
1274	} else
1275		error = EHOSTUNREACH; /* XXX */
1276
1277	*mtup = mtu;
1278	if (alwaysfragp)
1279		*alwaysfragp = alwaysfrag;
1280	return (error);
1281}
1282
1283/*
1284 * IP6 socket option processing.
1285 */
1286int
1287ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1288{
1289	int optdatalen, uproto;
1290	void *optdata;
1291	struct inpcb *in6p = sotoinpcb(so);
1292	int error, optval;
1293	int level, op, optname;
1294	int optlen;
1295	struct thread *td;
1296
1297	level = sopt->sopt_level;
1298	op = sopt->sopt_dir;
1299	optname = sopt->sopt_name;
1300	optlen = sopt->sopt_valsize;
1301	td = sopt->sopt_td;
1302	error = 0;
1303	optval = 0;
1304	uproto = (int)so->so_proto->pr_protocol;
1305
1306	if (level != IPPROTO_IPV6) {
1307		error = EINVAL;
1308
1309		if (sopt->sopt_level == SOL_SOCKET &&
1310		    sopt->sopt_dir == SOPT_SET) {
1311			switch (sopt->sopt_name) {
1312			case SO_REUSEADDR:
1313				INP_WLOCK(in6p);
1314				if ((so->so_options & SO_REUSEADDR) != 0)
1315					in6p->inp_flags2 |= INP_REUSEADDR;
1316				else
1317					in6p->inp_flags2 &= ~INP_REUSEADDR;
1318				INP_WUNLOCK(in6p);
1319				error = 0;
1320				break;
1321			case SO_REUSEPORT:
1322				INP_WLOCK(in6p);
1323				if ((so->so_options & SO_REUSEPORT) != 0)
1324					in6p->inp_flags2 |= INP_REUSEPORT;
1325				else
1326					in6p->inp_flags2 &= ~INP_REUSEPORT;
1327				INP_WUNLOCK(in6p);
1328				error = 0;
1329				break;
1330			case SO_SETFIB:
1331				INP_WLOCK(in6p);
1332				in6p->inp_inc.inc_fibnum = so->so_fibnum;
1333				INP_WUNLOCK(in6p);
1334				error = 0;
1335				break;
1336			default:
1337				break;
1338			}
1339		}
1340	} else {		/* level == IPPROTO_IPV6 */
1341		switch (op) {
1342
1343		case SOPT_SET:
1344			switch (optname) {
1345			case IPV6_2292PKTOPTIONS:
1346#ifdef IPV6_PKTOPTIONS
1347			case IPV6_PKTOPTIONS:
1348#endif
1349			{
1350				struct mbuf *m;
1351
1352				error = soopt_getm(sopt, &m); /* XXX */
1353				if (error != 0)
1354					break;
1355				error = soopt_mcopyin(sopt, m); /* XXX */
1356				if (error != 0)
1357					break;
1358				error = ip6_pcbopts(&in6p->in6p_outputopts,
1359						    m, so, sopt);
1360				m_freem(m); /* XXX */
1361				break;
1362			}
1363
1364			/*
1365			 * Use of some Hop-by-Hop options or some
1366			 * Destination options, might require special
1367			 * privilege.  That is, normal applications
1368			 * (without special privilege) might be forbidden
1369			 * from setting certain options in outgoing packets,
1370			 * and might never see certain options in received
1371			 * packets. [RFC 2292 Section 6]
1372			 * KAME specific note:
1373			 *  KAME prevents non-privileged users from sending or
1374			 *  receiving ANY hbh/dst options in order to avoid
1375			 *  overhead of parsing options in the kernel.
1376			 */
1377			case IPV6_RECVHOPOPTS:
1378			case IPV6_RECVDSTOPTS:
1379			case IPV6_RECVRTHDRDSTOPTS:
1380				if (td != NULL) {
1381					error = priv_check(td,
1382					    PRIV_NETINET_SETHDROPTS);
1383					if (error)
1384						break;
1385				}
1386				/* FALLTHROUGH */
1387			case IPV6_UNICAST_HOPS:
1388			case IPV6_HOPLIMIT:
1389			case IPV6_FAITH:
1390
1391			case IPV6_RECVPKTINFO:
1392			case IPV6_RECVHOPLIMIT:
1393			case IPV6_RECVRTHDR:
1394			case IPV6_RECVPATHMTU:
1395			case IPV6_RECVTCLASS:
1396			case IPV6_V6ONLY:
1397			case IPV6_AUTOFLOWLABEL:
1398			case IPV6_BINDANY:
1399				if (optname == IPV6_BINDANY && td != NULL) {
1400					error = priv_check(td,
1401					    PRIV_NETINET_BINDANY);
1402					if (error)
1403						break;
1404				}
1405
1406				if (optlen != sizeof(int)) {
1407					error = EINVAL;
1408					break;
1409				}
1410				error = sooptcopyin(sopt, &optval,
1411					sizeof optval, sizeof optval);
1412				if (error)
1413					break;
1414				switch (optname) {
1415
1416				case IPV6_UNICAST_HOPS:
1417					if (optval < -1 || optval >= 256)
1418						error = EINVAL;
1419					else {
1420						/* -1 = kernel default */
1421						in6p->in6p_hops = optval;
1422						if ((in6p->inp_vflag &
1423						     INP_IPV4) != 0)
1424							in6p->inp_ip_ttl = optval;
1425					}
1426					break;
1427#define OPTSET(bit) \
1428do { \
1429	INP_WLOCK(in6p); \
1430	if (optval) \
1431		in6p->inp_flags |= (bit); \
1432	else \
1433		in6p->inp_flags &= ~(bit); \
1434	INP_WUNLOCK(in6p); \
1435} while (/*CONSTCOND*/ 0)
1436#define OPTSET2292(bit) \
1437do { \
1438	INP_WLOCK(in6p); \
1439	in6p->inp_flags |= IN6P_RFC2292; \
1440	if (optval) \
1441		in6p->inp_flags |= (bit); \
1442	else \
1443		in6p->inp_flags &= ~(bit); \
1444	INP_WUNLOCK(in6p); \
1445} while (/*CONSTCOND*/ 0)
1446#define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1447
1448				case IPV6_RECVPKTINFO:
1449					/* cannot mix with RFC2292 */
1450					if (OPTBIT(IN6P_RFC2292)) {
1451						error = EINVAL;
1452						break;
1453					}
1454					OPTSET(IN6P_PKTINFO);
1455					break;
1456
1457				case IPV6_HOPLIMIT:
1458				{
1459					struct ip6_pktopts **optp;
1460
1461					/* cannot mix with RFC2292 */
1462					if (OPTBIT(IN6P_RFC2292)) {
1463						error = EINVAL;
1464						break;
1465					}
1466					optp = &in6p->in6p_outputopts;
1467					error = ip6_pcbopt(IPV6_HOPLIMIT,
1468					    (u_char *)&optval, sizeof(optval),
1469					    optp, (td != NULL) ? td->td_ucred :
1470					    NULL, uproto);
1471					break;
1472				}
1473
1474				case IPV6_RECVHOPLIMIT:
1475					/* cannot mix with RFC2292 */
1476					if (OPTBIT(IN6P_RFC2292)) {
1477						error = EINVAL;
1478						break;
1479					}
1480					OPTSET(IN6P_HOPLIMIT);
1481					break;
1482
1483				case IPV6_RECVHOPOPTS:
1484					/* cannot mix with RFC2292 */
1485					if (OPTBIT(IN6P_RFC2292)) {
1486						error = EINVAL;
1487						break;
1488					}
1489					OPTSET(IN6P_HOPOPTS);
1490					break;
1491
1492				case IPV6_RECVDSTOPTS:
1493					/* cannot mix with RFC2292 */
1494					if (OPTBIT(IN6P_RFC2292)) {
1495						error = EINVAL;
1496						break;
1497					}
1498					OPTSET(IN6P_DSTOPTS);
1499					break;
1500
1501				case IPV6_RECVRTHDRDSTOPTS:
1502					/* cannot mix with RFC2292 */
1503					if (OPTBIT(IN6P_RFC2292)) {
1504						error = EINVAL;
1505						break;
1506					}
1507					OPTSET(IN6P_RTHDRDSTOPTS);
1508					break;
1509
1510				case IPV6_RECVRTHDR:
1511					/* cannot mix with RFC2292 */
1512					if (OPTBIT(IN6P_RFC2292)) {
1513						error = EINVAL;
1514						break;
1515					}
1516					OPTSET(IN6P_RTHDR);
1517					break;
1518
1519				case IPV6_FAITH:
1520					OPTSET(INP_FAITH);
1521					break;
1522
1523				case IPV6_RECVPATHMTU:
1524					/*
1525					 * We ignore this option for TCP
1526					 * sockets.
1527					 * (RFC3542 leaves this case
1528					 * unspecified.)
1529					 */
1530					if (uproto != IPPROTO_TCP)
1531						OPTSET(IN6P_MTU);
1532					break;
1533
1534				case IPV6_V6ONLY:
1535					/*
1536					 * make setsockopt(IPV6_V6ONLY)
1537					 * available only prior to bind(2).
1538					 * see ipng mailing list, Jun 22 2001.
1539					 */
1540					if (in6p->inp_lport ||
1541					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1542						error = EINVAL;
1543						break;
1544					}
1545					OPTSET(IN6P_IPV6_V6ONLY);
1546					if (optval)
1547						in6p->inp_vflag &= ~INP_IPV4;
1548					else
1549						in6p->inp_vflag |= INP_IPV4;
1550					break;
1551				case IPV6_RECVTCLASS:
1552					/* cannot mix with RFC2292 XXX */
1553					if (OPTBIT(IN6P_RFC2292)) {
1554						error = EINVAL;
1555						break;
1556					}
1557					OPTSET(IN6P_TCLASS);
1558					break;
1559				case IPV6_AUTOFLOWLABEL:
1560					OPTSET(IN6P_AUTOFLOWLABEL);
1561					break;
1562
1563				case IPV6_BINDANY:
1564					OPTSET(INP_BINDANY);
1565					break;
1566				}
1567				break;
1568
1569			case IPV6_TCLASS:
1570			case IPV6_DONTFRAG:
1571			case IPV6_USE_MIN_MTU:
1572			case IPV6_PREFER_TEMPADDR:
1573				if (optlen != sizeof(optval)) {
1574					error = EINVAL;
1575					break;
1576				}
1577				error = sooptcopyin(sopt, &optval,
1578					sizeof optval, sizeof optval);
1579				if (error)
1580					break;
1581				{
1582					struct ip6_pktopts **optp;
1583					optp = &in6p->in6p_outputopts;
1584					error = ip6_pcbopt(optname,
1585					    (u_char *)&optval, sizeof(optval),
1586					    optp, (td != NULL) ? td->td_ucred :
1587					    NULL, uproto);
1588					break;
1589				}
1590
1591			case IPV6_2292PKTINFO:
1592			case IPV6_2292HOPLIMIT:
1593			case IPV6_2292HOPOPTS:
1594			case IPV6_2292DSTOPTS:
1595			case IPV6_2292RTHDR:
1596				/* RFC 2292 */
1597				if (optlen != sizeof(int)) {
1598					error = EINVAL;
1599					break;
1600				}
1601				error = sooptcopyin(sopt, &optval,
1602					sizeof optval, sizeof optval);
1603				if (error)
1604					break;
1605				switch (optname) {
1606				case IPV6_2292PKTINFO:
1607					OPTSET2292(IN6P_PKTINFO);
1608					break;
1609				case IPV6_2292HOPLIMIT:
1610					OPTSET2292(IN6P_HOPLIMIT);
1611					break;
1612				case IPV6_2292HOPOPTS:
1613					/*
1614					 * Check super-user privilege.
1615					 * See comments for IPV6_RECVHOPOPTS.
1616					 */
1617					if (td != NULL) {
1618						error = priv_check(td,
1619						    PRIV_NETINET_SETHDROPTS);
1620						if (error)
1621							return (error);
1622					}
1623					OPTSET2292(IN6P_HOPOPTS);
1624					break;
1625				case IPV6_2292DSTOPTS:
1626					if (td != NULL) {
1627						error = priv_check(td,
1628						    PRIV_NETINET_SETHDROPTS);
1629						if (error)
1630							return (error);
1631					}
1632					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1633					break;
1634				case IPV6_2292RTHDR:
1635					OPTSET2292(IN6P_RTHDR);
1636					break;
1637				}
1638				break;
1639			case IPV6_PKTINFO:
1640			case IPV6_HOPOPTS:
1641			case IPV6_RTHDR:
1642			case IPV6_DSTOPTS:
1643			case IPV6_RTHDRDSTOPTS:
1644			case IPV6_NEXTHOP:
1645			{
1646				/* new advanced API (RFC3542) */
1647				u_char *optbuf;
1648				u_char optbuf_storage[MCLBYTES];
1649				int optlen;
1650				struct ip6_pktopts **optp;
1651
1652				/* cannot mix with RFC2292 */
1653				if (OPTBIT(IN6P_RFC2292)) {
1654					error = EINVAL;
1655					break;
1656				}
1657
1658				/*
1659				 * We only ensure valsize is not too large
1660				 * here.  Further validation will be done
1661				 * later.
1662				 */
1663				error = sooptcopyin(sopt, optbuf_storage,
1664				    sizeof(optbuf_storage), 0);
1665				if (error)
1666					break;
1667				optlen = sopt->sopt_valsize;
1668				optbuf = optbuf_storage;
1669				optp = &in6p->in6p_outputopts;
1670				error = ip6_pcbopt(optname, optbuf, optlen,
1671				    optp, (td != NULL) ? td->td_ucred : NULL,
1672				    uproto);
1673				break;
1674			}
1675#undef OPTSET
1676
1677			case IPV6_MULTICAST_IF:
1678			case IPV6_MULTICAST_HOPS:
1679			case IPV6_MULTICAST_LOOP:
1680			case IPV6_JOIN_GROUP:
1681			case IPV6_LEAVE_GROUP:
1682			case IPV6_MSFILTER:
1683			case MCAST_BLOCK_SOURCE:
1684			case MCAST_UNBLOCK_SOURCE:
1685			case MCAST_JOIN_GROUP:
1686			case MCAST_LEAVE_GROUP:
1687			case MCAST_JOIN_SOURCE_GROUP:
1688			case MCAST_LEAVE_SOURCE_GROUP:
1689				error = ip6_setmoptions(in6p, sopt);
1690				break;
1691
1692			case IPV6_PORTRANGE:
1693				error = sooptcopyin(sopt, &optval,
1694				    sizeof optval, sizeof optval);
1695				if (error)
1696					break;
1697
1698				INP_WLOCK(in6p);
1699				switch (optval) {
1700				case IPV6_PORTRANGE_DEFAULT:
1701					in6p->inp_flags &= ~(INP_LOWPORT);
1702					in6p->inp_flags &= ~(INP_HIGHPORT);
1703					break;
1704
1705				case IPV6_PORTRANGE_HIGH:
1706					in6p->inp_flags &= ~(INP_LOWPORT);
1707					in6p->inp_flags |= INP_HIGHPORT;
1708					break;
1709
1710				case IPV6_PORTRANGE_LOW:
1711					in6p->inp_flags &= ~(INP_HIGHPORT);
1712					in6p->inp_flags |= INP_LOWPORT;
1713					break;
1714
1715				default:
1716					error = EINVAL;
1717					break;
1718				}
1719				INP_WUNLOCK(in6p);
1720				break;
1721
1722#ifdef IPSEC
1723			case IPV6_IPSEC_POLICY:
1724			{
1725				caddr_t req;
1726				struct mbuf *m;
1727
1728				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1729					break;
1730				if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1731					break;
1732				req = mtod(m, caddr_t);
1733				error = ipsec_set_policy(in6p, optname, req,
1734				    m->m_len, (sopt->sopt_td != NULL) ?
1735				    sopt->sopt_td->td_ucred : NULL);
1736				m_freem(m);
1737				break;
1738			}
1739#endif /* IPSEC */
1740
1741			default:
1742				error = ENOPROTOOPT;
1743				break;
1744			}
1745			break;
1746
1747		case SOPT_GET:
1748			switch (optname) {
1749
1750			case IPV6_2292PKTOPTIONS:
1751#ifdef IPV6_PKTOPTIONS
1752			case IPV6_PKTOPTIONS:
1753#endif
1754				/*
1755				 * RFC3542 (effectively) deprecated the
1756				 * semantics of the 2292-style pktoptions.
1757				 * Since it was not reliable in nature (i.e.,
1758				 * applications had to expect the lack of some
1759				 * information after all), it would make sense
1760				 * to simplify this part by always returning
1761				 * empty data.
1762				 */
1763				sopt->sopt_valsize = 0;
1764				break;
1765
1766			case IPV6_RECVHOPOPTS:
1767			case IPV6_RECVDSTOPTS:
1768			case IPV6_RECVRTHDRDSTOPTS:
1769			case IPV6_UNICAST_HOPS:
1770			case IPV6_RECVPKTINFO:
1771			case IPV6_RECVHOPLIMIT:
1772			case IPV6_RECVRTHDR:
1773			case IPV6_RECVPATHMTU:
1774
1775			case IPV6_FAITH:
1776			case IPV6_V6ONLY:
1777			case IPV6_PORTRANGE:
1778			case IPV6_RECVTCLASS:
1779			case IPV6_AUTOFLOWLABEL:
1780			case IPV6_BINDANY:
1781				switch (optname) {
1782
1783				case IPV6_RECVHOPOPTS:
1784					optval = OPTBIT(IN6P_HOPOPTS);
1785					break;
1786
1787				case IPV6_RECVDSTOPTS:
1788					optval = OPTBIT(IN6P_DSTOPTS);
1789					break;
1790
1791				case IPV6_RECVRTHDRDSTOPTS:
1792					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1793					break;
1794
1795				case IPV6_UNICAST_HOPS:
1796					optval = in6p->in6p_hops;
1797					break;
1798
1799				case IPV6_RECVPKTINFO:
1800					optval = OPTBIT(IN6P_PKTINFO);
1801					break;
1802
1803				case IPV6_RECVHOPLIMIT:
1804					optval = OPTBIT(IN6P_HOPLIMIT);
1805					break;
1806
1807				case IPV6_RECVRTHDR:
1808					optval = OPTBIT(IN6P_RTHDR);
1809					break;
1810
1811				case IPV6_RECVPATHMTU:
1812					optval = OPTBIT(IN6P_MTU);
1813					break;
1814
1815				case IPV6_FAITH:
1816					optval = OPTBIT(INP_FAITH);
1817					break;
1818
1819				case IPV6_V6ONLY:
1820					optval = OPTBIT(IN6P_IPV6_V6ONLY);
1821					break;
1822
1823				case IPV6_PORTRANGE:
1824				    {
1825					int flags;
1826					flags = in6p->inp_flags;
1827					if (flags & INP_HIGHPORT)
1828						optval = IPV6_PORTRANGE_HIGH;
1829					else if (flags & INP_LOWPORT)
1830						optval = IPV6_PORTRANGE_LOW;
1831					else
1832						optval = 0;
1833					break;
1834				    }
1835				case IPV6_RECVTCLASS:
1836					optval = OPTBIT(IN6P_TCLASS);
1837					break;
1838
1839				case IPV6_AUTOFLOWLABEL:
1840					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1841					break;
1842
1843				case IPV6_BINDANY:
1844					optval = OPTBIT(INP_BINDANY);
1845					break;
1846				}
1847				if (error)
1848					break;
1849				error = sooptcopyout(sopt, &optval,
1850					sizeof optval);
1851				break;
1852
1853			case IPV6_PATHMTU:
1854			{
1855				u_long pmtu = 0;
1856				struct ip6_mtuinfo mtuinfo;
1857				struct route_in6 sro;
1858
1859				bzero(&sro, sizeof(sro));
1860
1861				if (!(so->so_state & SS_ISCONNECTED))
1862					return (ENOTCONN);
1863				/*
1864				 * XXX: we dot not consider the case of source
1865				 * routing, or optional information to specify
1866				 * the outgoing interface.
1867				 */
1868				error = ip6_getpmtu(&sro, NULL, NULL,
1869				    &in6p->in6p_faddr, &pmtu, NULL,
1870				    so->so_fibnum);
1871				if (sro.ro_rt)
1872					RTFREE(sro.ro_rt);
1873				if (error)
1874					break;
1875				if (pmtu > IPV6_MAXPACKET)
1876					pmtu = IPV6_MAXPACKET;
1877
1878				bzero(&mtuinfo, sizeof(mtuinfo));
1879				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1880				optdata = (void *)&mtuinfo;
1881				optdatalen = sizeof(mtuinfo);
1882				error = sooptcopyout(sopt, optdata,
1883				    optdatalen);
1884				break;
1885			}
1886
1887			case IPV6_2292PKTINFO:
1888			case IPV6_2292HOPLIMIT:
1889			case IPV6_2292HOPOPTS:
1890			case IPV6_2292RTHDR:
1891			case IPV6_2292DSTOPTS:
1892				switch (optname) {
1893				case IPV6_2292PKTINFO:
1894					optval = OPTBIT(IN6P_PKTINFO);
1895					break;
1896				case IPV6_2292HOPLIMIT:
1897					optval = OPTBIT(IN6P_HOPLIMIT);
1898					break;
1899				case IPV6_2292HOPOPTS:
1900					optval = OPTBIT(IN6P_HOPOPTS);
1901					break;
1902				case IPV6_2292RTHDR:
1903					optval = OPTBIT(IN6P_RTHDR);
1904					break;
1905				case IPV6_2292DSTOPTS:
1906					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1907					break;
1908				}
1909				error = sooptcopyout(sopt, &optval,
1910				    sizeof optval);
1911				break;
1912			case IPV6_PKTINFO:
1913			case IPV6_HOPOPTS:
1914			case IPV6_RTHDR:
1915			case IPV6_DSTOPTS:
1916			case IPV6_RTHDRDSTOPTS:
1917			case IPV6_NEXTHOP:
1918			case IPV6_TCLASS:
1919			case IPV6_DONTFRAG:
1920			case IPV6_USE_MIN_MTU:
1921			case IPV6_PREFER_TEMPADDR:
1922				error = ip6_getpcbopt(in6p->in6p_outputopts,
1923				    optname, sopt);
1924				break;
1925
1926			case IPV6_MULTICAST_IF:
1927			case IPV6_MULTICAST_HOPS:
1928			case IPV6_MULTICAST_LOOP:
1929			case IPV6_MSFILTER:
1930				error = ip6_getmoptions(in6p, sopt);
1931				break;
1932
1933#ifdef IPSEC
1934			case IPV6_IPSEC_POLICY:
1935			  {
1936				caddr_t req = NULL;
1937				size_t len = 0;
1938				struct mbuf *m = NULL;
1939				struct mbuf **mp = &m;
1940				size_t ovalsize = sopt->sopt_valsize;
1941				caddr_t oval = (caddr_t)sopt->sopt_val;
1942
1943				error = soopt_getm(sopt, &m); /* XXX */
1944				if (error != 0)
1945					break;
1946				error = soopt_mcopyin(sopt, m); /* XXX */
1947				if (error != 0)
1948					break;
1949				sopt->sopt_valsize = ovalsize;
1950				sopt->sopt_val = oval;
1951				if (m) {
1952					req = mtod(m, caddr_t);
1953					len = m->m_len;
1954				}
1955				error = ipsec_get_policy(in6p, req, len, mp);
1956				if (error == 0)
1957					error = soopt_mcopyout(sopt, m); /* XXX */
1958				if (error == 0 && m)
1959					m_freem(m);
1960				break;
1961			  }
1962#endif /* IPSEC */
1963
1964			default:
1965				error = ENOPROTOOPT;
1966				break;
1967			}
1968			break;
1969		}
1970	}
1971	return (error);
1972}
1973
1974int
1975ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
1976{
1977	int error = 0, optval, optlen;
1978	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
1979	struct inpcb *in6p = sotoinpcb(so);
1980	int level, op, optname;
1981
1982	level = sopt->sopt_level;
1983	op = sopt->sopt_dir;
1984	optname = sopt->sopt_name;
1985	optlen = sopt->sopt_valsize;
1986
1987	if (level != IPPROTO_IPV6) {
1988		return (EINVAL);
1989	}
1990
1991	switch (optname) {
1992	case IPV6_CHECKSUM:
1993		/*
1994		 * For ICMPv6 sockets, no modification allowed for checksum
1995		 * offset, permit "no change" values to help existing apps.
1996		 *
1997		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
1998		 * for an ICMPv6 socket will fail."
1999		 * The current behavior does not meet RFC3542.
2000		 */
2001		switch (op) {
2002		case SOPT_SET:
2003			if (optlen != sizeof(int)) {
2004				error = EINVAL;
2005				break;
2006			}
2007			error = sooptcopyin(sopt, &optval, sizeof(optval),
2008					    sizeof(optval));
2009			if (error)
2010				break;
2011			if ((optval % 2) != 0) {
2012				/* the API assumes even offset values */
2013				error = EINVAL;
2014			} else if (so->so_proto->pr_protocol ==
2015			    IPPROTO_ICMPV6) {
2016				if (optval != icmp6off)
2017					error = EINVAL;
2018			} else
2019				in6p->in6p_cksum = optval;
2020			break;
2021
2022		case SOPT_GET:
2023			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2024				optval = icmp6off;
2025			else
2026				optval = in6p->in6p_cksum;
2027
2028			error = sooptcopyout(sopt, &optval, sizeof(optval));
2029			break;
2030
2031		default:
2032			error = EINVAL;
2033			break;
2034		}
2035		break;
2036
2037	default:
2038		error = ENOPROTOOPT;
2039		break;
2040	}
2041
2042	return (error);
2043}
2044
2045/*
2046 * Set up IP6 options in pcb for insertion in output packets or
2047 * specifying behavior of outgoing packets.
2048 */
2049static int
2050ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2051    struct socket *so, struct sockopt *sopt)
2052{
2053	struct ip6_pktopts *opt = *pktopt;
2054	int error = 0;
2055	struct thread *td = sopt->sopt_td;
2056
2057	/* turn off any old options. */
2058	if (opt) {
2059#ifdef DIAGNOSTIC
2060		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2061		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2062		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2063			printf("ip6_pcbopts: all specified options are cleared.\n");
2064#endif
2065		ip6_clearpktopts(opt, -1);
2066	} else
2067		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2068	*pktopt = NULL;
2069
2070	if (!m || m->m_len == 0) {
2071		/*
2072		 * Only turning off any previous options, regardless of
2073		 * whether the opt is just created or given.
2074		 */
2075		free(opt, M_IP6OPT);
2076		return (0);
2077	}
2078
2079	/*  set options specified by user. */
2080	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2081	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2082		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2083		free(opt, M_IP6OPT);
2084		return (error);
2085	}
2086	*pktopt = opt;
2087	return (0);
2088}
2089
2090/*
2091 * initialize ip6_pktopts.  beware that there are non-zero default values in
2092 * the struct.
2093 */
2094void
2095ip6_initpktopts(struct ip6_pktopts *opt)
2096{
2097
2098	bzero(opt, sizeof(*opt));
2099	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2100	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2101	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2102	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2103}
2104
2105static int
2106ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2107    struct ucred *cred, int uproto)
2108{
2109	struct ip6_pktopts *opt;
2110
2111	if (*pktopt == NULL) {
2112		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2113		    M_WAITOK);
2114		ip6_initpktopts(*pktopt);
2115	}
2116	opt = *pktopt;
2117
2118	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2119}
2120
2121static int
2122ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2123{
2124	void *optdata = NULL;
2125	int optdatalen = 0;
2126	struct ip6_ext *ip6e;
2127	int error = 0;
2128	struct in6_pktinfo null_pktinfo;
2129	int deftclass = 0, on;
2130	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2131	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2132
2133	switch (optname) {
2134	case IPV6_PKTINFO:
2135		if (pktopt && pktopt->ip6po_pktinfo)
2136			optdata = (void *)pktopt->ip6po_pktinfo;
2137		else {
2138			/* XXX: we don't have to do this every time... */
2139			bzero(&null_pktinfo, sizeof(null_pktinfo));
2140			optdata = (void *)&null_pktinfo;
2141		}
2142		optdatalen = sizeof(struct in6_pktinfo);
2143		break;
2144	case IPV6_TCLASS:
2145		if (pktopt && pktopt->ip6po_tclass >= 0)
2146			optdata = (void *)&pktopt->ip6po_tclass;
2147		else
2148			optdata = (void *)&deftclass;
2149		optdatalen = sizeof(int);
2150		break;
2151	case IPV6_HOPOPTS:
2152		if (pktopt && pktopt->ip6po_hbh) {
2153			optdata = (void *)pktopt->ip6po_hbh;
2154			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2155			optdatalen = (ip6e->ip6e_len + 1) << 3;
2156		}
2157		break;
2158	case IPV6_RTHDR:
2159		if (pktopt && pktopt->ip6po_rthdr) {
2160			optdata = (void *)pktopt->ip6po_rthdr;
2161			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2162			optdatalen = (ip6e->ip6e_len + 1) << 3;
2163		}
2164		break;
2165	case IPV6_RTHDRDSTOPTS:
2166		if (pktopt && pktopt->ip6po_dest1) {
2167			optdata = (void *)pktopt->ip6po_dest1;
2168			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2169			optdatalen = (ip6e->ip6e_len + 1) << 3;
2170		}
2171		break;
2172	case IPV6_DSTOPTS:
2173		if (pktopt && pktopt->ip6po_dest2) {
2174			optdata = (void *)pktopt->ip6po_dest2;
2175			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2176			optdatalen = (ip6e->ip6e_len + 1) << 3;
2177		}
2178		break;
2179	case IPV6_NEXTHOP:
2180		if (pktopt && pktopt->ip6po_nexthop) {
2181			optdata = (void *)pktopt->ip6po_nexthop;
2182			optdatalen = pktopt->ip6po_nexthop->sa_len;
2183		}
2184		break;
2185	case IPV6_USE_MIN_MTU:
2186		if (pktopt)
2187			optdata = (void *)&pktopt->ip6po_minmtu;
2188		else
2189			optdata = (void *)&defminmtu;
2190		optdatalen = sizeof(int);
2191		break;
2192	case IPV6_DONTFRAG:
2193		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2194			on = 1;
2195		else
2196			on = 0;
2197		optdata = (void *)&on;
2198		optdatalen = sizeof(on);
2199		break;
2200	case IPV6_PREFER_TEMPADDR:
2201		if (pktopt)
2202			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2203		else
2204			optdata = (void *)&defpreftemp;
2205		optdatalen = sizeof(int);
2206		break;
2207	default:		/* should not happen */
2208#ifdef DIAGNOSTIC
2209		panic("ip6_getpcbopt: unexpected option\n");
2210#endif
2211		return (ENOPROTOOPT);
2212	}
2213
2214	error = sooptcopyout(sopt, optdata, optdatalen);
2215
2216	return (error);
2217}
2218
2219void
2220ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2221{
2222	if (pktopt == NULL)
2223		return;
2224
2225	if (optname == -1 || optname == IPV6_PKTINFO) {
2226		if (pktopt->ip6po_pktinfo)
2227			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2228		pktopt->ip6po_pktinfo = NULL;
2229	}
2230	if (optname == -1 || optname == IPV6_HOPLIMIT)
2231		pktopt->ip6po_hlim = -1;
2232	if (optname == -1 || optname == IPV6_TCLASS)
2233		pktopt->ip6po_tclass = -1;
2234	if (optname == -1 || optname == IPV6_NEXTHOP) {
2235		if (pktopt->ip6po_nextroute.ro_rt) {
2236			RTFREE(pktopt->ip6po_nextroute.ro_rt);
2237			pktopt->ip6po_nextroute.ro_rt = NULL;
2238		}
2239		if (pktopt->ip6po_nexthop)
2240			free(pktopt->ip6po_nexthop, M_IP6OPT);
2241		pktopt->ip6po_nexthop = NULL;
2242	}
2243	if (optname == -1 || optname == IPV6_HOPOPTS) {
2244		if (pktopt->ip6po_hbh)
2245			free(pktopt->ip6po_hbh, M_IP6OPT);
2246		pktopt->ip6po_hbh = NULL;
2247	}
2248	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2249		if (pktopt->ip6po_dest1)
2250			free(pktopt->ip6po_dest1, M_IP6OPT);
2251		pktopt->ip6po_dest1 = NULL;
2252	}
2253	if (optname == -1 || optname == IPV6_RTHDR) {
2254		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2255			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2256		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2257		if (pktopt->ip6po_route.ro_rt) {
2258			RTFREE(pktopt->ip6po_route.ro_rt);
2259			pktopt->ip6po_route.ro_rt = NULL;
2260		}
2261	}
2262	if (optname == -1 || optname == IPV6_DSTOPTS) {
2263		if (pktopt->ip6po_dest2)
2264			free(pktopt->ip6po_dest2, M_IP6OPT);
2265		pktopt->ip6po_dest2 = NULL;
2266	}
2267}
2268
2269#define PKTOPT_EXTHDRCPY(type) \
2270do {\
2271	if (src->type) {\
2272		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2273		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2274		if (dst->type == NULL && canwait == M_NOWAIT)\
2275			goto bad;\
2276		bcopy(src->type, dst->type, hlen);\
2277	}\
2278} while (/*CONSTCOND*/ 0)
2279
2280static int
2281copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2282{
2283	if (dst == NULL || src == NULL)  {
2284		printf("ip6_clearpktopts: invalid argument\n");
2285		return (EINVAL);
2286	}
2287
2288	dst->ip6po_hlim = src->ip6po_hlim;
2289	dst->ip6po_tclass = src->ip6po_tclass;
2290	dst->ip6po_flags = src->ip6po_flags;
2291	dst->ip6po_minmtu = src->ip6po_minmtu;
2292	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2293	if (src->ip6po_pktinfo) {
2294		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2295		    M_IP6OPT, canwait);
2296		if (dst->ip6po_pktinfo == NULL)
2297			goto bad;
2298		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2299	}
2300	if (src->ip6po_nexthop) {
2301		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2302		    M_IP6OPT, canwait);
2303		if (dst->ip6po_nexthop == NULL)
2304			goto bad;
2305		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2306		    src->ip6po_nexthop->sa_len);
2307	}
2308	PKTOPT_EXTHDRCPY(ip6po_hbh);
2309	PKTOPT_EXTHDRCPY(ip6po_dest1);
2310	PKTOPT_EXTHDRCPY(ip6po_dest2);
2311	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2312	return (0);
2313
2314  bad:
2315	ip6_clearpktopts(dst, -1);
2316	return (ENOBUFS);
2317}
2318#undef PKTOPT_EXTHDRCPY
2319
2320struct ip6_pktopts *
2321ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2322{
2323	int error;
2324	struct ip6_pktopts *dst;
2325
2326	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2327	if (dst == NULL)
2328		return (NULL);
2329	ip6_initpktopts(dst);
2330
2331	if ((error = copypktopts(dst, src, canwait)) != 0) {
2332		free(dst, M_IP6OPT);
2333		return (NULL);
2334	}
2335
2336	return (dst);
2337}
2338
2339void
2340ip6_freepcbopts(struct ip6_pktopts *pktopt)
2341{
2342	if (pktopt == NULL)
2343		return;
2344
2345	ip6_clearpktopts(pktopt, -1);
2346
2347	free(pktopt, M_IP6OPT);
2348}
2349
2350/*
2351 * Set IPv6 outgoing packet options based on advanced API.
2352 */
2353int
2354ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2355    struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2356{
2357	struct cmsghdr *cm = 0;
2358
2359	if (control == NULL || opt == NULL)
2360		return (EINVAL);
2361
2362	ip6_initpktopts(opt);
2363	if (stickyopt) {
2364		int error;
2365
2366		/*
2367		 * If stickyopt is provided, make a local copy of the options
2368		 * for this particular packet, then override them by ancillary
2369		 * objects.
2370		 * XXX: copypktopts() does not copy the cached route to a next
2371		 * hop (if any).  This is not very good in terms of efficiency,
2372		 * but we can allow this since this option should be rarely
2373		 * used.
2374		 */
2375		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2376			return (error);
2377	}
2378
2379	/*
2380	 * XXX: Currently, we assume all the optional information is stored
2381	 * in a single mbuf.
2382	 */
2383	if (control->m_next)
2384		return (EINVAL);
2385
2386	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2387	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2388		int error;
2389
2390		if (control->m_len < CMSG_LEN(0))
2391			return (EINVAL);
2392
2393		cm = mtod(control, struct cmsghdr *);
2394		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2395			return (EINVAL);
2396		if (cm->cmsg_level != IPPROTO_IPV6)
2397			continue;
2398
2399		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2400		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2401		if (error)
2402			return (error);
2403	}
2404
2405	return (0);
2406}
2407
2408/*
2409 * Set a particular packet option, as a sticky option or an ancillary data
2410 * item.  "len" can be 0 only when it's a sticky option.
2411 * We have 4 cases of combination of "sticky" and "cmsg":
2412 * "sticky=0, cmsg=0": impossible
2413 * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2414 * "sticky=1, cmsg=0": RFC3542 socket option
2415 * "sticky=1, cmsg=1": RFC2292 socket option
2416 */
2417static int
2418ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2419    struct ucred *cred, int sticky, int cmsg, int uproto)
2420{
2421	int minmtupolicy, preftemp;
2422	int error;
2423
2424	if (!sticky && !cmsg) {
2425#ifdef DIAGNOSTIC
2426		printf("ip6_setpktopt: impossible case\n");
2427#endif
2428		return (EINVAL);
2429	}
2430
2431	/*
2432	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2433	 * not be specified in the context of RFC3542.  Conversely,
2434	 * RFC3542 types should not be specified in the context of RFC2292.
2435	 */
2436	if (!cmsg) {
2437		switch (optname) {
2438		case IPV6_2292PKTINFO:
2439		case IPV6_2292HOPLIMIT:
2440		case IPV6_2292NEXTHOP:
2441		case IPV6_2292HOPOPTS:
2442		case IPV6_2292DSTOPTS:
2443		case IPV6_2292RTHDR:
2444		case IPV6_2292PKTOPTIONS:
2445			return (ENOPROTOOPT);
2446		}
2447	}
2448	if (sticky && cmsg) {
2449		switch (optname) {
2450		case IPV6_PKTINFO:
2451		case IPV6_HOPLIMIT:
2452		case IPV6_NEXTHOP:
2453		case IPV6_HOPOPTS:
2454		case IPV6_DSTOPTS:
2455		case IPV6_RTHDRDSTOPTS:
2456		case IPV6_RTHDR:
2457		case IPV6_USE_MIN_MTU:
2458		case IPV6_DONTFRAG:
2459		case IPV6_TCLASS:
2460		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2461			return (ENOPROTOOPT);
2462		}
2463	}
2464
2465	switch (optname) {
2466	case IPV6_2292PKTINFO:
2467	case IPV6_PKTINFO:
2468	{
2469		struct ifnet *ifp = NULL;
2470		struct in6_pktinfo *pktinfo;
2471
2472		if (len != sizeof(struct in6_pktinfo))
2473			return (EINVAL);
2474
2475		pktinfo = (struct in6_pktinfo *)buf;
2476
2477		/*
2478		 * An application can clear any sticky IPV6_PKTINFO option by
2479		 * doing a "regular" setsockopt with ipi6_addr being
2480		 * in6addr_any and ipi6_ifindex being zero.
2481		 * [RFC 3542, Section 6]
2482		 */
2483		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2484		    pktinfo->ipi6_ifindex == 0 &&
2485		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2486			ip6_clearpktopts(opt, optname);
2487			break;
2488		}
2489
2490		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2491		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2492			return (EINVAL);
2493		}
2494
2495		/* validate the interface index if specified. */
2496		if (pktinfo->ipi6_ifindex > V_if_index ||
2497		    pktinfo->ipi6_ifindex < 0) {
2498			 return (ENXIO);
2499		}
2500		if (pktinfo->ipi6_ifindex) {
2501			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2502			if (ifp == NULL)
2503				return (ENXIO);
2504		}
2505
2506		/*
2507		 * We store the address anyway, and let in6_selectsrc()
2508		 * validate the specified address.  This is because ipi6_addr
2509		 * may not have enough information about its scope zone, and
2510		 * we may need additional information (such as outgoing
2511		 * interface or the scope zone of a destination address) to
2512		 * disambiguate the scope.
2513		 * XXX: the delay of the validation may confuse the
2514		 * application when it is used as a sticky option.
2515		 */
2516		if (opt->ip6po_pktinfo == NULL) {
2517			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2518			    M_IP6OPT, M_NOWAIT);
2519			if (opt->ip6po_pktinfo == NULL)
2520				return (ENOBUFS);
2521		}
2522		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2523		break;
2524	}
2525
2526	case IPV6_2292HOPLIMIT:
2527	case IPV6_HOPLIMIT:
2528	{
2529		int *hlimp;
2530
2531		/*
2532		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2533		 * to simplify the ordering among hoplimit options.
2534		 */
2535		if (optname == IPV6_HOPLIMIT && sticky)
2536			return (ENOPROTOOPT);
2537
2538		if (len != sizeof(int))
2539			return (EINVAL);
2540		hlimp = (int *)buf;
2541		if (*hlimp < -1 || *hlimp > 255)
2542			return (EINVAL);
2543
2544		opt->ip6po_hlim = *hlimp;
2545		break;
2546	}
2547
2548	case IPV6_TCLASS:
2549	{
2550		int tclass;
2551
2552		if (len != sizeof(int))
2553			return (EINVAL);
2554		tclass = *(int *)buf;
2555		if (tclass < -1 || tclass > 255)
2556			return (EINVAL);
2557
2558		opt->ip6po_tclass = tclass;
2559		break;
2560	}
2561
2562	case IPV6_2292NEXTHOP:
2563	case IPV6_NEXTHOP:
2564		if (cred != NULL) {
2565			error = priv_check_cred(cred,
2566			    PRIV_NETINET_SETHDROPTS, 0);
2567			if (error)
2568				return (error);
2569		}
2570
2571		if (len == 0) {	/* just remove the option */
2572			ip6_clearpktopts(opt, IPV6_NEXTHOP);
2573			break;
2574		}
2575
2576		/* check if cmsg_len is large enough for sa_len */
2577		if (len < sizeof(struct sockaddr) || len < *buf)
2578			return (EINVAL);
2579
2580		switch (((struct sockaddr *)buf)->sa_family) {
2581		case AF_INET6:
2582		{
2583			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2584			int error;
2585
2586			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2587				return (EINVAL);
2588
2589			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2590			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2591				return (EINVAL);
2592			}
2593			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2594			    != 0) {
2595				return (error);
2596			}
2597			break;
2598		}
2599		case AF_LINK:	/* should eventually be supported */
2600		default:
2601			return (EAFNOSUPPORT);
2602		}
2603
2604		/* turn off the previous option, then set the new option. */
2605		ip6_clearpktopts(opt, IPV6_NEXTHOP);
2606		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2607		if (opt->ip6po_nexthop == NULL)
2608			return (ENOBUFS);
2609		bcopy(buf, opt->ip6po_nexthop, *buf);
2610		break;
2611
2612	case IPV6_2292HOPOPTS:
2613	case IPV6_HOPOPTS:
2614	{
2615		struct ip6_hbh *hbh;
2616		int hbhlen;
2617
2618		/*
2619		 * XXX: We don't allow a non-privileged user to set ANY HbH
2620		 * options, since per-option restriction has too much
2621		 * overhead.
2622		 */
2623		if (cred != NULL) {
2624			error = priv_check_cred(cred,
2625			    PRIV_NETINET_SETHDROPTS, 0);
2626			if (error)
2627				return (error);
2628		}
2629
2630		if (len == 0) {
2631			ip6_clearpktopts(opt, IPV6_HOPOPTS);
2632			break;	/* just remove the option */
2633		}
2634
2635		/* message length validation */
2636		if (len < sizeof(struct ip6_hbh))
2637			return (EINVAL);
2638		hbh = (struct ip6_hbh *)buf;
2639		hbhlen = (hbh->ip6h_len + 1) << 3;
2640		if (len != hbhlen)
2641			return (EINVAL);
2642
2643		/* turn off the previous option, then set the new option. */
2644		ip6_clearpktopts(opt, IPV6_HOPOPTS);
2645		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2646		if (opt->ip6po_hbh == NULL)
2647			return (ENOBUFS);
2648		bcopy(hbh, opt->ip6po_hbh, hbhlen);
2649
2650		break;
2651	}
2652
2653	case IPV6_2292DSTOPTS:
2654	case IPV6_DSTOPTS:
2655	case IPV6_RTHDRDSTOPTS:
2656	{
2657		struct ip6_dest *dest, **newdest = NULL;
2658		int destlen;
2659
2660		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2661			error = priv_check_cred(cred,
2662			    PRIV_NETINET_SETHDROPTS, 0);
2663			if (error)
2664				return (error);
2665		}
2666
2667		if (len == 0) {
2668			ip6_clearpktopts(opt, optname);
2669			break;	/* just remove the option */
2670		}
2671
2672		/* message length validation */
2673		if (len < sizeof(struct ip6_dest))
2674			return (EINVAL);
2675		dest = (struct ip6_dest *)buf;
2676		destlen = (dest->ip6d_len + 1) << 3;
2677		if (len != destlen)
2678			return (EINVAL);
2679
2680		/*
2681		 * Determine the position that the destination options header
2682		 * should be inserted; before or after the routing header.
2683		 */
2684		switch (optname) {
2685		case IPV6_2292DSTOPTS:
2686			/*
2687			 * The old advacned API is ambiguous on this point.
2688			 * Our approach is to determine the position based
2689			 * according to the existence of a routing header.
2690			 * Note, however, that this depends on the order of the
2691			 * extension headers in the ancillary data; the 1st
2692			 * part of the destination options header must appear
2693			 * before the routing header in the ancillary data,
2694			 * too.
2695			 * RFC3542 solved the ambiguity by introducing
2696			 * separate ancillary data or option types.
2697			 */
2698			if (opt->ip6po_rthdr == NULL)
2699				newdest = &opt->ip6po_dest1;
2700			else
2701				newdest = &opt->ip6po_dest2;
2702			break;
2703		case IPV6_RTHDRDSTOPTS:
2704			newdest = &opt->ip6po_dest1;
2705			break;
2706		case IPV6_DSTOPTS:
2707			newdest = &opt->ip6po_dest2;
2708			break;
2709		}
2710
2711		/* turn off the previous option, then set the new option. */
2712		ip6_clearpktopts(opt, optname);
2713		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2714		if (*newdest == NULL)
2715			return (ENOBUFS);
2716		bcopy(dest, *newdest, destlen);
2717
2718		break;
2719	}
2720
2721	case IPV6_2292RTHDR:
2722	case IPV6_RTHDR:
2723	{
2724		struct ip6_rthdr *rth;
2725		int rthlen;
2726
2727		if (len == 0) {
2728			ip6_clearpktopts(opt, IPV6_RTHDR);
2729			break;	/* just remove the option */
2730		}
2731
2732		/* message length validation */
2733		if (len < sizeof(struct ip6_rthdr))
2734			return (EINVAL);
2735		rth = (struct ip6_rthdr *)buf;
2736		rthlen = (rth->ip6r_len + 1) << 3;
2737		if (len != rthlen)
2738			return (EINVAL);
2739
2740		switch (rth->ip6r_type) {
2741		case IPV6_RTHDR_TYPE_0:
2742			if (rth->ip6r_len == 0)	/* must contain one addr */
2743				return (EINVAL);
2744			if (rth->ip6r_len % 2) /* length must be even */
2745				return (EINVAL);
2746			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2747				return (EINVAL);
2748			break;
2749		default:
2750			return (EINVAL);	/* not supported */
2751		}
2752
2753		/* turn off the previous option */
2754		ip6_clearpktopts(opt, IPV6_RTHDR);
2755		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2756		if (opt->ip6po_rthdr == NULL)
2757			return (ENOBUFS);
2758		bcopy(rth, opt->ip6po_rthdr, rthlen);
2759
2760		break;
2761	}
2762
2763	case IPV6_USE_MIN_MTU:
2764		if (len != sizeof(int))
2765			return (EINVAL);
2766		minmtupolicy = *(int *)buf;
2767		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2768		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
2769		    minmtupolicy != IP6PO_MINMTU_ALL) {
2770			return (EINVAL);
2771		}
2772		opt->ip6po_minmtu = minmtupolicy;
2773		break;
2774
2775	case IPV6_DONTFRAG:
2776		if (len != sizeof(int))
2777			return (EINVAL);
2778
2779		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2780			/*
2781			 * we ignore this option for TCP sockets.
2782			 * (RFC3542 leaves this case unspecified.)
2783			 */
2784			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2785		} else
2786			opt->ip6po_flags |= IP6PO_DONTFRAG;
2787		break;
2788
2789	case IPV6_PREFER_TEMPADDR:
2790		if (len != sizeof(int))
2791			return (EINVAL);
2792		preftemp = *(int *)buf;
2793		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2794		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2795		    preftemp != IP6PO_TEMPADDR_PREFER) {
2796			return (EINVAL);
2797		}
2798		opt->ip6po_prefer_tempaddr = preftemp;
2799		break;
2800
2801	default:
2802		return (ENOPROTOOPT);
2803	} /* end of switch */
2804
2805	return (0);
2806}
2807
2808/*
2809 * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2810 * packet to the input queue of a specified interface.  Note that this
2811 * calls the output routine of the loopback "driver", but with an interface
2812 * pointer that might NOT be &loif -- easier than replicating that code here.
2813 */
2814void
2815ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2816{
2817	struct mbuf *copym;
2818	struct ip6_hdr *ip6;
2819
2820	copym = m_copy(m, 0, M_COPYALL);
2821	if (copym == NULL)
2822		return;
2823
2824	/*
2825	 * Make sure to deep-copy IPv6 header portion in case the data
2826	 * is in an mbuf cluster, so that we can safely override the IPv6
2827	 * header portion later.
2828	 */
2829	if ((copym->m_flags & M_EXT) != 0 ||
2830	    copym->m_len < sizeof(struct ip6_hdr)) {
2831		copym = m_pullup(copym, sizeof(struct ip6_hdr));
2832		if (copym == NULL)
2833			return;
2834	}
2835	ip6 = mtod(copym, struct ip6_hdr *);
2836	/*
2837	 * clear embedded scope identifiers if necessary.
2838	 * in6_clearscope will touch the addresses only when necessary.
2839	 */
2840	in6_clearscope(&ip6->ip6_src);
2841	in6_clearscope(&ip6->ip6_dst);
2842	if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
2843		copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
2844		    CSUM_PSEUDO_HDR;
2845		copym->m_pkthdr.csum_data = 0xffff;
2846	}
2847	(void)if_simloop(ifp, copym, dst->sin6_family, 0);
2848}
2849
2850/*
2851 * Chop IPv6 header off from the payload.
2852 */
2853static int
2854ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
2855{
2856	struct mbuf *mh;
2857	struct ip6_hdr *ip6;
2858
2859	ip6 = mtod(m, struct ip6_hdr *);
2860	if (m->m_len > sizeof(*ip6)) {
2861		mh = m_gethdr(M_NOWAIT, MT_DATA);
2862		if (mh == NULL) {
2863			m_freem(m);
2864			return ENOBUFS;
2865		}
2866		m_move_pkthdr(mh, m);
2867		MH_ALIGN(mh, sizeof(*ip6));
2868		m->m_len -= sizeof(*ip6);
2869		m->m_data += sizeof(*ip6);
2870		mh->m_next = m;
2871		m = mh;
2872		m->m_len = sizeof(*ip6);
2873		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
2874	}
2875	exthdrs->ip6e_ip6 = m;
2876	return 0;
2877}
2878
2879/*
2880 * Compute IPv6 extension header length.
2881 */
2882int
2883ip6_optlen(struct inpcb *in6p)
2884{
2885	int len;
2886
2887	if (!in6p->in6p_outputopts)
2888		return 0;
2889
2890	len = 0;
2891#define elen(x) \
2892    (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
2893
2894	len += elen(in6p->in6p_outputopts->ip6po_hbh);
2895	if (in6p->in6p_outputopts->ip6po_rthdr)
2896		/* dest1 is valid with rthdr only */
2897		len += elen(in6p->in6p_outputopts->ip6po_dest1);
2898	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
2899	len += elen(in6p->in6p_outputopts->ip6po_dest2);
2900	return len;
2901#undef elen
2902}
2903