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: stable/10/sys/netinet6/ip6_output.c 343139 2019-01-18 08:59:00Z hselasky $");
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	KASSERT(( mtu % 8 == 0), ("Fragment length must be a multiple of 8"));
223
224	m = m0;
225	ip6 = mtod(m, struct ip6_hdr *);
226	mnext = &m->m_nextpkt;
227
228	for (off = hlen; off < tlen; off += mtu) {
229		m = m_gethdr(M_NOWAIT, MT_DATA);
230		if (!m) {
231			IP6STAT_INC(ip6s_odropped);
232			return (ENOBUFS);
233		}
234		m->m_flags = m0->m_flags & M_COPYFLAGS;
235		*mnext = m;
236		mnext = &m->m_nextpkt;
237		m->m_data += max_linkhdr;
238		mhip6 = mtod(m, struct ip6_hdr *);
239		*mhip6 = *ip6;
240		m->m_len = sizeof(*mhip6);
241		error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
242		if (error) {
243			IP6STAT_INC(ip6s_odropped);
244			return (error);
245		}
246		ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
247		if (off + mtu >= tlen)
248			mtu = tlen - off;
249		else
250			ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
251		mhip6->ip6_plen = htons((u_short)(mtu + hlen +
252		    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
253		if ((m_frgpart = m_copy(m0, off, mtu)) == 0) {
254			IP6STAT_INC(ip6s_odropped);
255			return (ENOBUFS);
256		}
257		m_cat(m, m_frgpart);
258		m->m_pkthdr.len = mtu + hlen + sizeof(*ip6f);
259		m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
260		m->m_pkthdr.rcvif = NULL;
261		ip6f->ip6f_reserved = 0;
262		ip6f->ip6f_ident = id;
263		ip6f->ip6f_nxt = nextproto;
264		IP6STAT_INC(ip6s_ofragments);
265		in6_ifstat_inc(ifp, ifs6_out_fragcreat);
266	}
267
268	return (0);
269}
270
271/*
272 * IP6 output. The packet in mbuf chain m contains a skeletal IP6
273 * header (with pri, len, nxt, hlim, src, dst).
274 * This function may modify ver and hlim only.
275 * The mbuf chain containing the packet will be freed.
276 * The mbuf opt, if present, will not be freed.
277 * If route_in6 ro is present and has ro_rt initialized, route lookup would be
278 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
279 * then result of route lookup is stored in ro->ro_rt.
280 *
281 * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
282 * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
283 * which is rt_mtu.
284 *
285 * ifpp - XXX: just for statistics
286 */
287int
288ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
289    struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
290    struct ifnet **ifpp, struct inpcb *inp)
291{
292	struct ip6_hdr *ip6;
293	struct ifnet *ifp, *origifp;
294	struct mbuf *m = m0;
295	struct mbuf *mprev = NULL;
296	int hlen, tlen, len;
297	struct route_in6 ip6route;
298	struct rtentry *rt = NULL;
299	struct sockaddr_in6 *dst, src_sa, dst_sa;
300	struct in6_addr odst;
301	int error = 0;
302	struct in6_ifaddr *ia = NULL;
303	u_long mtu;
304	int alwaysfrag, dontfrag;
305	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
306	struct ip6_exthdrs exthdrs;
307	struct in6_addr finaldst, src0, dst0;
308	u_int32_t zone;
309	struct route_in6 *ro_pmtu = NULL;
310	int hdrsplit = 0;
311	int sw_csum, tso;
312	struct m_tag *fwd_tag = NULL;
313	uint32_t id;
314
315	ip6 = mtod(m, struct ip6_hdr *);
316	if (ip6 == NULL) {
317		printf ("ip6 is NULL");
318		goto bad;
319	}
320
321	if (inp != NULL)
322		M_SETFIB(m, inp->inp_inc.inc_fibnum);
323
324	finaldst = ip6->ip6_dst;
325	bzero(&exthdrs, sizeof(exthdrs));
326	if (opt) {
327		/* Hop-by-Hop options header */
328		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
329		/* Destination options header(1st part) */
330		if (opt->ip6po_rthdr) {
331			/*
332			 * Destination options header(1st part)
333			 * This only makes sense with a routing header.
334			 * See Section 9.2 of RFC 3542.
335			 * Disabling this part just for MIP6 convenience is
336			 * a bad idea.  We need to think carefully about a
337			 * way to make the advanced API coexist with MIP6
338			 * options, which might automatically be inserted in
339			 * the kernel.
340			 */
341			MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
342		}
343		/* Routing header */
344		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
345		/* Destination options header(2nd part) */
346		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
347	}
348
349#ifdef IPSEC
350	/*
351	 * IPSec checking which handles several cases.
352	 * FAST IPSEC: We re-injected the packet.
353	 */
354	switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp))
355	{
356	case 1:                 /* Bad packet */
357		goto freehdrs;
358	case -1:                /* IPSec done */
359		goto done;
360	case 0:                 /* No IPSec */
361	default:
362		break;
363	}
364#endif /* IPSEC */
365
366	/*
367	 * Calculate the total length of the extension header chain.
368	 * Keep the length of the unfragmentable part for fragmentation.
369	 */
370	optlen = 0;
371	if (exthdrs.ip6e_hbh)
372		optlen += exthdrs.ip6e_hbh->m_len;
373	if (exthdrs.ip6e_dest1)
374		optlen += exthdrs.ip6e_dest1->m_len;
375	if (exthdrs.ip6e_rthdr)
376		optlen += exthdrs.ip6e_rthdr->m_len;
377	unfragpartlen = optlen + sizeof(struct ip6_hdr);
378
379	/* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
380	if (exthdrs.ip6e_dest2)
381		optlen += exthdrs.ip6e_dest2->m_len;
382
383	/*
384	 * If there is at least one extension header,
385	 * separate IP6 header from the payload.
386	 */
387	if (optlen && !hdrsplit) {
388		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
389			m = NULL;
390			goto freehdrs;
391		}
392		m = exthdrs.ip6e_ip6;
393		hdrsplit++;
394	}
395
396	/* adjust pointer */
397	ip6 = mtod(m, struct ip6_hdr *);
398
399	/* adjust mbuf packet header length */
400	m->m_pkthdr.len += optlen;
401	plen = m->m_pkthdr.len - sizeof(*ip6);
402
403	/* If this is a jumbo payload, insert a jumbo payload option. */
404	if (plen > IPV6_MAXPACKET) {
405		if (!hdrsplit) {
406			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
407				m = NULL;
408				goto freehdrs;
409			}
410			m = exthdrs.ip6e_ip6;
411			hdrsplit++;
412		}
413		/* adjust pointer */
414		ip6 = mtod(m, struct ip6_hdr *);
415		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
416			goto freehdrs;
417		ip6->ip6_plen = 0;
418	} else
419		ip6->ip6_plen = htons(plen);
420
421	/*
422	 * Concatenate headers and fill in next header fields.
423	 * Here we have, on "m"
424	 *	IPv6 payload
425	 * and we insert headers accordingly.  Finally, we should be getting:
426	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
427	 *
428	 * during the header composing process, "m" points to IPv6 header.
429	 * "mprev" points to an extension header prior to esp.
430	 */
431	u_char *nexthdrp = &ip6->ip6_nxt;
432	mprev = m;
433
434	/*
435	 * we treat dest2 specially.  this makes IPsec processing
436	 * much easier.  the goal here is to make mprev point the
437	 * mbuf prior to dest2.
438	 *
439	 * result: IPv6 dest2 payload
440	 * m and mprev will point to IPv6 header.
441	 */
442	if (exthdrs.ip6e_dest2) {
443		if (!hdrsplit)
444			panic("assumption failed: hdr not split");
445		exthdrs.ip6e_dest2->m_next = m->m_next;
446		m->m_next = exthdrs.ip6e_dest2;
447		*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
448		ip6->ip6_nxt = IPPROTO_DSTOPTS;
449	}
450
451	/*
452	 * result: IPv6 hbh dest1 rthdr dest2 payload
453	 * m will point to IPv6 header.  mprev will point to the
454	 * extension header prior to dest2 (rthdr in the above case).
455	 */
456	MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
457	MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
458		   IPPROTO_DSTOPTS);
459	MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
460		   IPPROTO_ROUTING);
461
462	/*
463	 * If there is a routing header, discard the packet.
464	 */
465	if (exthdrs.ip6e_rthdr) {
466		 error = EINVAL;
467		 goto bad;
468	}
469
470	/* Source address validation */
471	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
472	    (flags & IPV6_UNSPECSRC) == 0) {
473		error = EOPNOTSUPP;
474		IP6STAT_INC(ip6s_badscope);
475		goto bad;
476	}
477	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
478		error = EOPNOTSUPP;
479		IP6STAT_INC(ip6s_badscope);
480		goto bad;
481	}
482
483	IP6STAT_INC(ip6s_localout);
484
485	/*
486	 * Route packet.
487	 */
488	if (ro == 0) {
489		ro = &ip6route;
490		bzero((caddr_t)ro, sizeof(*ro));
491	}
492	ro_pmtu = ro;
493	if (opt && opt->ip6po_rthdr)
494		ro = &opt->ip6po_route;
495	dst = (struct sockaddr_in6 *)&ro->ro_dst;
496#ifdef FLOWTABLE
497	if (ro->ro_rt == NULL)
498		(void )flowtable_lookup(AF_INET6, m, (struct route *)ro);
499#endif
500again:
501	/*
502	 * if specified, try to fill in the traffic class field.
503	 * do not override if a non-zero value is already set.
504	 * we check the diffserv field and the ecn field separately.
505	 */
506	if (opt && opt->ip6po_tclass >= 0) {
507		int mask = 0;
508
509		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
510			mask |= 0xfc;
511		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
512			mask |= 0x03;
513		if (mask != 0)
514			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
515	}
516
517	/* fill in or override the hop limit field, if necessary. */
518	if (opt && opt->ip6po_hlim != -1)
519		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
520	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
521		if (im6o != NULL)
522			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
523		else
524			ip6->ip6_hlim = V_ip6_defmcasthlim;
525	}
526
527	/* adjust pointer */
528	ip6 = mtod(m, struct ip6_hdr *);
529
530	if (ro->ro_rt && fwd_tag == NULL) {
531		rt = ro->ro_rt;
532		ifp = ro->ro_rt->rt_ifp;
533	} else {
534		if (fwd_tag == NULL) {
535			bzero(&dst_sa, sizeof(dst_sa));
536			dst_sa.sin6_family = AF_INET6;
537			dst_sa.sin6_len = sizeof(dst_sa);
538			dst_sa.sin6_addr = ip6->ip6_dst;
539		}
540		error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
541		    &rt, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
542		if (error != 0) {
543			if (ifp != NULL)
544				in6_ifstat_inc(ifp, ifs6_out_discard);
545			goto bad;
546		}
547	}
548	if (rt == NULL) {
549		/*
550		 * If in6_selectroute() does not return a route entry,
551		 * dst may not have been updated.
552		 */
553		*dst = dst_sa;	/* XXX */
554	}
555
556	/*
557	 * then rt (for unicast) and ifp must be non-NULL valid values.
558	 */
559	if ((flags & IPV6_FORWARDING) == 0) {
560		/* XXX: the FORWARDING flag can be set for mrouting. */
561		in6_ifstat_inc(ifp, ifs6_out_request);
562	}
563	if (rt != NULL) {
564		ia = (struct in6_ifaddr *)(rt->rt_ifa);
565		counter_u64_add(rt->rt_pksent, 1);
566	}
567
568	/* Setup data structures for scope ID checks. */
569	src0 = ip6->ip6_src;
570	bzero(&src_sa, sizeof(src_sa));
571	src_sa.sin6_family = AF_INET6;
572	src_sa.sin6_len = sizeof(src_sa);
573	src_sa.sin6_addr = ip6->ip6_src;
574
575	dst0 = ip6->ip6_dst;
576	/* re-initialize to be sure */
577	bzero(&dst_sa, sizeof(dst_sa));
578	dst_sa.sin6_family = AF_INET6;
579	dst_sa.sin6_len = sizeof(dst_sa);
580	dst_sa.sin6_addr = ip6->ip6_dst;
581
582	/* Check for valid scope ID. */
583	if (in6_setscope(&src0, ifp, &zone) == 0 &&
584	    sa6_recoverscope(&src_sa) == 0 && zone == src_sa.sin6_scope_id &&
585	    in6_setscope(&dst0, ifp, &zone) == 0 &&
586	    sa6_recoverscope(&dst_sa) == 0 && zone == dst_sa.sin6_scope_id) {
587		/*
588		 * The outgoing interface is in the zone of the source
589		 * and destination addresses.
590		 *
591		 * Because the loopback interface cannot receive
592		 * packets with a different scope ID than its own,
593		 * there is a trick is to pretend the outgoing packet
594		 * was received by the real network interface, by
595		 * setting "origifp" different from "ifp". This is
596		 * only allowed when "ifp" is a loopback network
597		 * interface. Refer to code in nd6_output_ifp() for
598		 * more details.
599		 */
600		origifp = ifp;
601
602		/*
603		 * We should use ia_ifp to support the case of sending
604		 * packets to an address of our own.
605		 */
606		if (ia != NULL && ia->ia_ifp)
607			ifp = ia->ia_ifp;
608
609	} else if ((ifp->if_flags & IFF_LOOPBACK) == 0 ||
610	    sa6_recoverscope(&src_sa) != 0 ||
611	    sa6_recoverscope(&dst_sa) != 0 ||
612	    dst_sa.sin6_scope_id == 0 ||
613	    (src_sa.sin6_scope_id != 0 &&
614	    src_sa.sin6_scope_id != dst_sa.sin6_scope_id) ||
615	    (origifp = ifnet_byindex(dst_sa.sin6_scope_id)) == NULL) {
616		/*
617		 * If the destination network interface is not a
618		 * loopback interface, or the destination network
619		 * address has no scope ID, or the source address has
620		 * a scope ID set which is different from the
621		 * destination address one, or there is no network
622		 * interface representing this scope ID, the address
623		 * pair is considered invalid.
624		 */
625		IP6STAT_INC(ip6s_badscope);
626		in6_ifstat_inc(ifp, ifs6_out_discard);
627		if (error == 0)
628			error = EHOSTUNREACH; /* XXX */
629		goto bad;
630	}
631
632	/* All scope ID checks are successful. */
633
634	if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
635		if (opt && opt->ip6po_nextroute.ro_rt) {
636			/*
637			 * The nexthop is explicitly specified by the
638			 * application.  We assume the next hop is an IPv6
639			 * address.
640			 */
641			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
642		}
643		else if ((rt->rt_flags & RTF_GATEWAY))
644			dst = (struct sockaddr_in6 *)rt->rt_gateway;
645	}
646
647	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
648		m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
649	} else {
650		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
651		in6_ifstat_inc(ifp, ifs6_out_mcast);
652		/*
653		 * Confirm that the outgoing interface supports multicast.
654		 */
655		if (!(ifp->if_flags & IFF_MULTICAST)) {
656			IP6STAT_INC(ip6s_noroute);
657			in6_ifstat_inc(ifp, ifs6_out_discard);
658			error = ENETUNREACH;
659			goto bad;
660		}
661		if ((im6o == NULL && in6_mcast_loop) ||
662		    (im6o && im6o->im6o_multicast_loop)) {
663			/*
664			 * Loop back multicast datagram if not expressly
665			 * forbidden to do so, even if we have not joined
666			 * the address; protocols will filter it later,
667			 * thus deferring a hash lookup and lock acquisition
668			 * at the expense of an m_copym().
669			 */
670			ip6_mloopback(ifp, m, dst);
671		} else {
672			/*
673			 * If we are acting as a multicast router, perform
674			 * multicast forwarding as if the packet had just
675			 * arrived on the interface to which we are about
676			 * to send.  The multicast forwarding function
677			 * recursively calls this function, using the
678			 * IPV6_FORWARDING flag to prevent infinite recursion.
679			 *
680			 * Multicasts that are looped back by ip6_mloopback(),
681			 * above, will be forwarded by the ip6_input() routine,
682			 * if necessary.
683			 */
684			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
685				/*
686				 * XXX: ip6_mforward expects that rcvif is NULL
687				 * when it is called from the originating path.
688				 * However, it may not always be the case.
689				 */
690				m->m_pkthdr.rcvif = NULL;
691				if (ip6_mforward(ip6, ifp, m) != 0) {
692					m_freem(m);
693					goto done;
694				}
695			}
696		}
697		/*
698		 * Multicasts with a hoplimit of zero may be looped back,
699		 * above, but must not be transmitted on a network.
700		 * Also, multicasts addressed to the loopback interface
701		 * are not sent -- the above call to ip6_mloopback() will
702		 * loop back a copy if this host actually belongs to the
703		 * destination group on the loopback interface.
704		 */
705		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
706		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
707			m_freem(m);
708			goto done;
709		}
710	}
711
712	/*
713	 * Fill the outgoing inteface to tell the upper layer
714	 * to increment per-interface statistics.
715	 */
716	if (ifpp)
717		*ifpp = ifp;
718
719	/* Determine path MTU. */
720	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
721	    &alwaysfrag, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m))) != 0)
722		goto bad;
723
724	/*
725	 * The caller of this function may specify to use the minimum MTU
726	 * in some cases.
727	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
728	 * setting.  The logic is a bit complicated; by default, unicast
729	 * packets will follow path MTU while multicast packets will be sent at
730	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
731	 * including unicast ones will be sent at the minimum MTU.  Multicast
732	 * packets will always be sent at the minimum MTU unless
733	 * IP6PO_MINMTU_DISABLE is explicitly specified.
734	 * See RFC 3542 for more details.
735	 */
736	if (mtu > IPV6_MMTU) {
737		if ((flags & IPV6_MINMTU))
738			mtu = IPV6_MMTU;
739		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
740			mtu = IPV6_MMTU;
741		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
742			 (opt == NULL ||
743			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
744			mtu = IPV6_MMTU;
745		}
746	}
747
748	/*
749	 * clear embedded scope identifiers if necessary.
750	 * in6_clearscope will touch the addresses only when necessary.
751	 */
752	in6_clearscope(&ip6->ip6_src);
753	in6_clearscope(&ip6->ip6_dst);
754
755	/*
756	 * If the outgoing packet contains a hop-by-hop options header,
757	 * it must be examined and processed even by the source node.
758	 * (RFC 2460, section 4.)
759	 */
760	if (exthdrs.ip6e_hbh) {
761		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
762		u_int32_t dummy; /* XXX unused */
763		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
764
765#ifdef DIAGNOSTIC
766		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
767			panic("ip6e_hbh is not contiguous");
768#endif
769		/*
770		 *  XXX: if we have to send an ICMPv6 error to the sender,
771		 *       we need the M_LOOP flag since icmp6_error() expects
772		 *       the IPv6 and the hop-by-hop options header are
773		 *       contiguous unless the flag is set.
774		 */
775		m->m_flags |= M_LOOP;
776		m->m_pkthdr.rcvif = ifp;
777		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
778		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
779		    &dummy, &plen) < 0) {
780			/* m was already freed at this point */
781			error = EINVAL;/* better error? */
782			goto done;
783		}
784		m->m_flags &= ~M_LOOP; /* XXX */
785		m->m_pkthdr.rcvif = NULL;
786	}
787
788	/* Jump over all PFIL processing if hooks are not active. */
789	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
790		goto passout;
791
792	odst = ip6->ip6_dst;
793	/* Run through list of hooks for output packets. */
794	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
795	if (error != 0 || m == NULL)
796		goto done;
797	ip6 = mtod(m, struct ip6_hdr *);
798
799	/* See if destination IP address was changed by packet filter. */
800	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
801		m->m_flags |= M_SKIP_FIREWALL;
802		/* If destination is now ourself drop to ip6_input(). */
803		if (in6_localip(&ip6->ip6_dst)) {
804			m->m_flags |= M_FASTFWD_OURS;
805			if (m->m_pkthdr.rcvif == NULL)
806				m->m_pkthdr.rcvif = V_loif;
807			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
808				m->m_pkthdr.csum_flags |=
809				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
810				m->m_pkthdr.csum_data = 0xffff;
811			}
812#ifdef SCTP
813			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
814				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
815#endif
816			error = netisr_queue(NETISR_IPV6, m);
817			goto done;
818		} else
819			goto again;	/* Redo the routing table lookup. */
820	}
821
822	/* See if local, if yes, send it to netisr. */
823	if (m->m_flags & M_FASTFWD_OURS) {
824		if (m->m_pkthdr.rcvif == NULL)
825			m->m_pkthdr.rcvif = V_loif;
826		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
827			m->m_pkthdr.csum_flags |=
828			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
829			m->m_pkthdr.csum_data = 0xffff;
830		}
831#ifdef SCTP
832		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
833			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
834#endif
835		error = netisr_queue(NETISR_IPV6, m);
836		goto done;
837	}
838	/* Or forward to some other address? */
839	if ((m->m_flags & M_IP6_NEXTHOP) &&
840	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
841		dst = (struct sockaddr_in6 *)&ro->ro_dst;
842		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
843		m->m_flags |= M_SKIP_FIREWALL;
844		m->m_flags &= ~M_IP6_NEXTHOP;
845		m_tag_delete(m, fwd_tag);
846		goto again;
847	}
848
849passout:
850	/*
851	 * Send the packet to the outgoing interface.
852	 * If necessary, do IPv6 fragmentation before sending.
853	 *
854	 * the logic here is rather complex:
855	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
856	 * 1-a:	send as is if tlen <= path mtu
857	 * 1-b:	fragment if tlen > path mtu
858	 *
859	 * 2: if user asks us not to fragment (dontfrag == 1)
860	 * 2-a:	send as is if tlen <= interface mtu
861	 * 2-b:	error if tlen > interface mtu
862	 *
863	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
864	 *	always fragment
865	 *
866	 * 4: if dontfrag == 1 && alwaysfrag == 1
867	 *	error, as we cannot handle this conflicting request
868	 */
869	sw_csum = m->m_pkthdr.csum_flags;
870	if (!hdrsplit) {
871		tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
872		sw_csum &= ~ifp->if_hwassist;
873	} else
874		tso = 0;
875	/*
876	 * If we added extension headers, we will not do TSO and calculate the
877	 * checksums ourselves for now.
878	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
879	 * with ext. hdrs.
880	 */
881	if (sw_csum & CSUM_DELAY_DATA_IPV6) {
882		sw_csum &= ~CSUM_DELAY_DATA_IPV6;
883		in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
884	}
885#ifdef SCTP
886	if (sw_csum & CSUM_SCTP_IPV6) {
887		sw_csum &= ~CSUM_SCTP_IPV6;
888		sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
889	}
890#endif
891	m->m_pkthdr.csum_flags &= ifp->if_hwassist;
892	tlen = m->m_pkthdr.len;
893
894	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
895		dontfrag = 1;
896	else
897		dontfrag = 0;
898	if (dontfrag && alwaysfrag) {	/* case 4 */
899		/* conflicting request - can't transmit */
900		error = EMSGSIZE;
901		goto bad;
902	}
903	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* case 2-b */
904		/*
905		 * Even if the DONTFRAG option is specified, we cannot send the
906		 * packet when the data length is larger than the MTU of the
907		 * outgoing interface.
908		 * Notify the error by sending IPV6_PATHMTU ancillary data if
909		 * application wanted to know the MTU value. Also return an
910		 * error code (this is not described in the API spec).
911		 */
912		if (inp != NULL)
913			ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
914		error = EMSGSIZE;
915		goto bad;
916	}
917
918	/*
919	 * transmit packet without fragmentation
920	 */
921	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* case 1-a and 2-a */
922		struct in6_ifaddr *ia6;
923
924		ip6 = mtod(m, struct ip6_hdr *);
925		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
926		if (ia6) {
927			/* Record statistics for this interface address. */
928			ia6->ia_ifa.if_opackets++;
929			ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
930			ifa_free(&ia6->ia_ifa);
931		}
932		error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
933		goto done;
934	}
935
936	/*
937	 * try to fragment the packet.  case 1-b and 3
938	 */
939	if (mtu < IPV6_MMTU) {
940		/* path MTU cannot be less than IPV6_MMTU */
941		error = EMSGSIZE;
942		in6_ifstat_inc(ifp, ifs6_out_fragfail);
943		goto bad;
944	} else if (ip6->ip6_plen == 0) {
945		/* jumbo payload cannot be fragmented */
946		error = EMSGSIZE;
947		in6_ifstat_inc(ifp, ifs6_out_fragfail);
948		goto bad;
949	} else {
950		u_char nextproto;
951
952		int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
953
954		/*
955		 * Too large for the destination or interface;
956		 * fragment if possible.
957		 * Must be able to put at least 8 bytes per fragment.
958		 */
959		hlen = unfragpartlen;
960		if (mtu > IPV6_MAXPACKET)
961			mtu = IPV6_MAXPACKET;
962
963		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
964		if (len < 8) {
965			error = EMSGSIZE;
966			in6_ifstat_inc(ifp, ifs6_out_fragfail);
967			goto bad;
968		}
969
970		/*
971		 * Verify that we have any chance at all of being able to queue
972		 *      the packet or packet fragments
973		 */
974		if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
975		    < tlen  /* - hlen */)) {
976			error = ENOBUFS;
977			IP6STAT_INC(ip6s_odropped);
978			goto bad;
979		}
980
981
982		/*
983		 * If the interface will not calculate checksums on
984		 * fragmented packets, then do it here.
985		 * XXX-BZ handle the hw offloading case.  Need flags.
986		 */
987		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
988			in6_delayed_cksum(m, plen, hlen);
989			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
990		}
991#ifdef SCTP
992		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
993			sctp_delayed_cksum(m, hlen);
994			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
995		}
996#endif
997		/*
998		 * Change the next header field of the last header in the
999		 * unfragmentable part.
1000		 */
1001		if (exthdrs.ip6e_rthdr) {
1002			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1003			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1004		} else if (exthdrs.ip6e_dest1) {
1005			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1006			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1007		} else if (exthdrs.ip6e_hbh) {
1008			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1009			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1010		} else {
1011			nextproto = ip6->ip6_nxt;
1012			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1013		}
1014
1015		/*
1016		 * Loop through length of segment after first fragment,
1017		 * make new header and copy data of each part and link onto
1018		 * chain.
1019		 */
1020		m0 = m;
1021		id = htonl(ip6_randomid());
1022		if ((error = ip6_fragment(ifp, m, hlen, nextproto, len, id)))
1023			goto sendorfree;
1024
1025		in6_ifstat_inc(ifp, ifs6_out_fragok);
1026	}
1027
1028	/*
1029	 * Remove leading garbages.
1030	 */
1031sendorfree:
1032	m = m0->m_nextpkt;
1033	m0->m_nextpkt = 0;
1034	m_freem(m0);
1035	for (m0 = m; m; m = m0) {
1036		m0 = m->m_nextpkt;
1037		m->m_nextpkt = 0;
1038		if (error == 0) {
1039			/* Record statistics for this interface address. */
1040			if (ia) {
1041				ia->ia_ifa.if_opackets++;
1042				ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1043			}
1044			error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1045		} else
1046			m_freem(m);
1047	}
1048
1049	if (error == 0)
1050		IP6STAT_INC(ip6s_fragmented);
1051
1052done:
1053	if (ro == &ip6route)
1054		RO_RTFREE(ro);
1055	if (ro_pmtu == &ip6route)
1056		RO_RTFREE(ro_pmtu);
1057	return (error);
1058
1059freehdrs:
1060	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
1061	m_freem(exthdrs.ip6e_dest1);
1062	m_freem(exthdrs.ip6e_rthdr);
1063	m_freem(exthdrs.ip6e_dest2);
1064	/* FALLTHROUGH */
1065bad:
1066	if (m)
1067		m_freem(m);
1068	goto done;
1069}
1070
1071static int
1072ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1073{
1074	struct mbuf *m;
1075
1076	if (hlen > MCLBYTES)
1077		return (ENOBUFS); /* XXX */
1078
1079	if (hlen > MLEN)
1080		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1081	else
1082		m = m_get(M_NOWAIT, MT_DATA);
1083	if (m == NULL)
1084		return (ENOBUFS);
1085	m->m_len = hlen;
1086	if (hdr)
1087		bcopy(hdr, mtod(m, caddr_t), hlen);
1088
1089	*mp = m;
1090	return (0);
1091}
1092
1093/*
1094 * Insert jumbo payload option.
1095 */
1096static int
1097ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1098{
1099	struct mbuf *mopt;
1100	u_char *optbuf;
1101	u_int32_t v;
1102
1103#define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1104
1105	/*
1106	 * If there is no hop-by-hop options header, allocate new one.
1107	 * If there is one but it doesn't have enough space to store the
1108	 * jumbo payload option, allocate a cluster to store the whole options.
1109	 * Otherwise, use it to store the options.
1110	 */
1111	if (exthdrs->ip6e_hbh == 0) {
1112		mopt = m_get(M_NOWAIT, MT_DATA);
1113		if (mopt == NULL)
1114			return (ENOBUFS);
1115		mopt->m_len = JUMBOOPTLEN;
1116		optbuf = mtod(mopt, u_char *);
1117		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1118		exthdrs->ip6e_hbh = mopt;
1119	} else {
1120		struct ip6_hbh *hbh;
1121
1122		mopt = exthdrs->ip6e_hbh;
1123		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1124			/*
1125			 * XXX assumption:
1126			 * - exthdrs->ip6e_hbh is not referenced from places
1127			 *   other than exthdrs.
1128			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1129			 */
1130			int oldoptlen = mopt->m_len;
1131			struct mbuf *n;
1132
1133			/*
1134			 * XXX: give up if the whole (new) hbh header does
1135			 * not fit even in an mbuf cluster.
1136			 */
1137			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1138				return (ENOBUFS);
1139
1140			/*
1141			 * As a consequence, we must always prepare a cluster
1142			 * at this point.
1143			 */
1144			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1145			if (n == NULL)
1146				return (ENOBUFS);
1147			n->m_len = oldoptlen + JUMBOOPTLEN;
1148			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1149			    oldoptlen);
1150			optbuf = mtod(n, caddr_t) + oldoptlen;
1151			m_freem(mopt);
1152			mopt = exthdrs->ip6e_hbh = n;
1153		} else {
1154			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1155			mopt->m_len += JUMBOOPTLEN;
1156		}
1157		optbuf[0] = IP6OPT_PADN;
1158		optbuf[1] = 1;
1159
1160		/*
1161		 * Adjust the header length according to the pad and
1162		 * the jumbo payload option.
1163		 */
1164		hbh = mtod(mopt, struct ip6_hbh *);
1165		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1166	}
1167
1168	/* fill in the option. */
1169	optbuf[2] = IP6OPT_JUMBO;
1170	optbuf[3] = 4;
1171	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1172	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1173
1174	/* finally, adjust the packet header length */
1175	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1176
1177	return (0);
1178#undef JUMBOOPTLEN
1179}
1180
1181/*
1182 * Insert fragment header and copy unfragmentable header portions.
1183 */
1184static int
1185ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1186    struct ip6_frag **frghdrp)
1187{
1188	struct mbuf *n, *mlast;
1189
1190	if (hlen > sizeof(struct ip6_hdr)) {
1191		n = m_copym(m0, sizeof(struct ip6_hdr),
1192		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1193		if (n == 0)
1194			return (ENOBUFS);
1195		m->m_next = n;
1196	} else
1197		n = m;
1198
1199	/* Search for the last mbuf of unfragmentable part. */
1200	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1201		;
1202
1203	if ((mlast->m_flags & M_EXT) == 0 &&
1204	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1205		/* use the trailing space of the last mbuf for the fragment hdr */
1206		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1207		    mlast->m_len);
1208		mlast->m_len += sizeof(struct ip6_frag);
1209		m->m_pkthdr.len += sizeof(struct ip6_frag);
1210	} else {
1211		/* allocate a new mbuf for the fragment header */
1212		struct mbuf *mfrg;
1213
1214		mfrg = m_get(M_NOWAIT, MT_DATA);
1215		if (mfrg == NULL)
1216			return (ENOBUFS);
1217		mfrg->m_len = sizeof(struct ip6_frag);
1218		*frghdrp = mtod(mfrg, struct ip6_frag *);
1219		mlast->m_next = mfrg;
1220	}
1221
1222	return (0);
1223}
1224
1225static int
1226ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1227    struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1228    int *alwaysfragp, u_int fibnum)
1229{
1230	u_int32_t mtu = 0;
1231	int alwaysfrag = 0;
1232	int error = 0;
1233
1234	if (ro_pmtu != ro) {
1235		/* The first hop and the final destination may differ. */
1236		struct sockaddr_in6 *sa6_dst =
1237		    (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1238		if (ro_pmtu->ro_rt &&
1239		    ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1240		     !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1241			RTFREE(ro_pmtu->ro_rt);
1242			ro_pmtu->ro_rt = (struct rtentry *)NULL;
1243		}
1244		if (ro_pmtu->ro_rt == NULL) {
1245			bzero(sa6_dst, sizeof(*sa6_dst));
1246			sa6_dst->sin6_family = AF_INET6;
1247			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1248			sa6_dst->sin6_addr = *dst;
1249
1250			in6_rtalloc(ro_pmtu, fibnum);
1251		}
1252	}
1253	if (ro_pmtu->ro_rt) {
1254		u_int32_t ifmtu;
1255		struct in_conninfo inc;
1256
1257		bzero(&inc, sizeof(inc));
1258		inc.inc_flags |= INC_ISIPV6;
1259		inc.inc6_faddr = *dst;
1260
1261		if (ifp == NULL)
1262			ifp = ro_pmtu->ro_rt->rt_ifp;
1263		ifmtu = IN6_LINKMTU(ifp);
1264		mtu = tcp_hc_getmtu(&inc);
1265		if (mtu)
1266			mtu = min(mtu, ro_pmtu->ro_rt->rt_mtu);
1267		else
1268			mtu = ro_pmtu->ro_rt->rt_mtu;
1269		if (mtu == 0)
1270			mtu = ifmtu;
1271		else if (mtu < IPV6_MMTU) {
1272			/*
1273			 * RFC2460 section 5, last paragraph:
1274			 * if we record ICMPv6 too big message with
1275			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1276			 * or smaller, with framgent header attached.
1277			 * (fragment header is needed regardless from the
1278			 * packet size, for translators to identify packets)
1279			 */
1280			alwaysfrag = 1;
1281			mtu = IPV6_MMTU;
1282		} else if (mtu > ifmtu) {
1283			/*
1284			 * The MTU on the route is larger than the MTU on
1285			 * the interface!  This shouldn't happen, unless the
1286			 * MTU of the interface has been changed after the
1287			 * interface was brought up.  Change the MTU in the
1288			 * route to match the interface MTU (as long as the
1289			 * field isn't locked).
1290			 */
1291			mtu = ifmtu;
1292			ro_pmtu->ro_rt->rt_mtu = mtu;
1293		}
1294	} else if (ifp) {
1295		mtu = IN6_LINKMTU(ifp);
1296	} else
1297		error = EHOSTUNREACH; /* XXX */
1298
1299	*mtup = mtu;
1300	if (alwaysfragp)
1301		*alwaysfragp = alwaysfrag;
1302	return (error);
1303}
1304
1305/*
1306 * IP6 socket option processing.
1307 */
1308int
1309ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1310{
1311	int optdatalen, uproto;
1312	void *optdata;
1313	struct inpcb *in6p = sotoinpcb(so);
1314	int error, optval;
1315	int level, op, optname;
1316	int optlen;
1317	struct thread *td;
1318
1319	level = sopt->sopt_level;
1320	op = sopt->sopt_dir;
1321	optname = sopt->sopt_name;
1322	optlen = sopt->sopt_valsize;
1323	td = sopt->sopt_td;
1324	error = 0;
1325	optval = 0;
1326	uproto = (int)so->so_proto->pr_protocol;
1327
1328	if (level != IPPROTO_IPV6) {
1329		error = EINVAL;
1330
1331		if (sopt->sopt_level == SOL_SOCKET &&
1332		    sopt->sopt_dir == SOPT_SET) {
1333			switch (sopt->sopt_name) {
1334			case SO_REUSEADDR:
1335				INP_WLOCK(in6p);
1336				if ((so->so_options & SO_REUSEADDR) != 0)
1337					in6p->inp_flags2 |= INP_REUSEADDR;
1338				else
1339					in6p->inp_flags2 &= ~INP_REUSEADDR;
1340				INP_WUNLOCK(in6p);
1341				error = 0;
1342				break;
1343			case SO_REUSEPORT:
1344				INP_WLOCK(in6p);
1345				if ((so->so_options & SO_REUSEPORT) != 0)
1346					in6p->inp_flags2 |= INP_REUSEPORT;
1347				else
1348					in6p->inp_flags2 &= ~INP_REUSEPORT;
1349				INP_WUNLOCK(in6p);
1350				error = 0;
1351				break;
1352			case SO_SETFIB:
1353				INP_WLOCK(in6p);
1354				in6p->inp_inc.inc_fibnum = so->so_fibnum;
1355				INP_WUNLOCK(in6p);
1356				error = 0;
1357				break;
1358			default:
1359				break;
1360			}
1361		}
1362	} else {		/* level == IPPROTO_IPV6 */
1363		switch (op) {
1364
1365		case SOPT_SET:
1366			switch (optname) {
1367			case IPV6_2292PKTOPTIONS:
1368#ifdef IPV6_PKTOPTIONS
1369			case IPV6_PKTOPTIONS:
1370#endif
1371			{
1372				struct mbuf *m;
1373
1374				error = soopt_getm(sopt, &m); /* XXX */
1375				if (error != 0)
1376					break;
1377				error = soopt_mcopyin(sopt, m); /* XXX */
1378				if (error != 0)
1379					break;
1380				error = ip6_pcbopts(&in6p->in6p_outputopts,
1381						    m, so, sopt);
1382				m_freem(m); /* XXX */
1383				break;
1384			}
1385
1386			/*
1387			 * Use of some Hop-by-Hop options or some
1388			 * Destination options, might require special
1389			 * privilege.  That is, normal applications
1390			 * (without special privilege) might be forbidden
1391			 * from setting certain options in outgoing packets,
1392			 * and might never see certain options in received
1393			 * packets. [RFC 2292 Section 6]
1394			 * KAME specific note:
1395			 *  KAME prevents non-privileged users from sending or
1396			 *  receiving ANY hbh/dst options in order to avoid
1397			 *  overhead of parsing options in the kernel.
1398			 */
1399			case IPV6_RECVHOPOPTS:
1400			case IPV6_RECVDSTOPTS:
1401			case IPV6_RECVRTHDRDSTOPTS:
1402				if (td != NULL) {
1403					error = priv_check(td,
1404					    PRIV_NETINET_SETHDROPTS);
1405					if (error)
1406						break;
1407				}
1408				/* FALLTHROUGH */
1409			case IPV6_UNICAST_HOPS:
1410			case IPV6_HOPLIMIT:
1411			case IPV6_FAITH:
1412
1413			case IPV6_RECVPKTINFO:
1414			case IPV6_RECVHOPLIMIT:
1415			case IPV6_RECVRTHDR:
1416			case IPV6_RECVPATHMTU:
1417			case IPV6_RECVTCLASS:
1418			case IPV6_V6ONLY:
1419			case IPV6_AUTOFLOWLABEL:
1420			case IPV6_BINDANY:
1421				if (optname == IPV6_BINDANY && td != NULL) {
1422					error = priv_check(td,
1423					    PRIV_NETINET_BINDANY);
1424					if (error)
1425						break;
1426				}
1427
1428				if (optlen != sizeof(int)) {
1429					error = EINVAL;
1430					break;
1431				}
1432				error = sooptcopyin(sopt, &optval,
1433					sizeof optval, sizeof optval);
1434				if (error)
1435					break;
1436				switch (optname) {
1437
1438				case IPV6_UNICAST_HOPS:
1439					if (optval < -1 || optval >= 256)
1440						error = EINVAL;
1441					else {
1442						/* -1 = kernel default */
1443						in6p->in6p_hops = optval;
1444						if ((in6p->inp_vflag &
1445						     INP_IPV4) != 0)
1446							in6p->inp_ip_ttl = optval;
1447					}
1448					break;
1449#define OPTSET(bit) \
1450do { \
1451	INP_WLOCK(in6p); \
1452	if (optval) \
1453		in6p->inp_flags |= (bit); \
1454	else \
1455		in6p->inp_flags &= ~(bit); \
1456	INP_WUNLOCK(in6p); \
1457} while (/*CONSTCOND*/ 0)
1458#define OPTSET2292(bit) \
1459do { \
1460	INP_WLOCK(in6p); \
1461	in6p->inp_flags |= IN6P_RFC2292; \
1462	if (optval) \
1463		in6p->inp_flags |= (bit); \
1464	else \
1465		in6p->inp_flags &= ~(bit); \
1466	INP_WUNLOCK(in6p); \
1467} while (/*CONSTCOND*/ 0)
1468#define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1469
1470				case IPV6_RECVPKTINFO:
1471					/* cannot mix with RFC2292 */
1472					if (OPTBIT(IN6P_RFC2292)) {
1473						error = EINVAL;
1474						break;
1475					}
1476					OPTSET(IN6P_PKTINFO);
1477					break;
1478
1479				case IPV6_HOPLIMIT:
1480				{
1481					struct ip6_pktopts **optp;
1482
1483					/* cannot mix with RFC2292 */
1484					if (OPTBIT(IN6P_RFC2292)) {
1485						error = EINVAL;
1486						break;
1487					}
1488					optp = &in6p->in6p_outputopts;
1489					error = ip6_pcbopt(IPV6_HOPLIMIT,
1490					    (u_char *)&optval, sizeof(optval),
1491					    optp, (td != NULL) ? td->td_ucred :
1492					    NULL, uproto);
1493					break;
1494				}
1495
1496				case IPV6_RECVHOPLIMIT:
1497					/* cannot mix with RFC2292 */
1498					if (OPTBIT(IN6P_RFC2292)) {
1499						error = EINVAL;
1500						break;
1501					}
1502					OPTSET(IN6P_HOPLIMIT);
1503					break;
1504
1505				case IPV6_RECVHOPOPTS:
1506					/* cannot mix with RFC2292 */
1507					if (OPTBIT(IN6P_RFC2292)) {
1508						error = EINVAL;
1509						break;
1510					}
1511					OPTSET(IN6P_HOPOPTS);
1512					break;
1513
1514				case IPV6_RECVDSTOPTS:
1515					/* cannot mix with RFC2292 */
1516					if (OPTBIT(IN6P_RFC2292)) {
1517						error = EINVAL;
1518						break;
1519					}
1520					OPTSET(IN6P_DSTOPTS);
1521					break;
1522
1523				case IPV6_RECVRTHDRDSTOPTS:
1524					/* cannot mix with RFC2292 */
1525					if (OPTBIT(IN6P_RFC2292)) {
1526						error = EINVAL;
1527						break;
1528					}
1529					OPTSET(IN6P_RTHDRDSTOPTS);
1530					break;
1531
1532				case IPV6_RECVRTHDR:
1533					/* cannot mix with RFC2292 */
1534					if (OPTBIT(IN6P_RFC2292)) {
1535						error = EINVAL;
1536						break;
1537					}
1538					OPTSET(IN6P_RTHDR);
1539					break;
1540
1541				case IPV6_FAITH:
1542					OPTSET(INP_FAITH);
1543					break;
1544
1545				case IPV6_RECVPATHMTU:
1546					/*
1547					 * We ignore this option for TCP
1548					 * sockets.
1549					 * (RFC3542 leaves this case
1550					 * unspecified.)
1551					 */
1552					if (uproto != IPPROTO_TCP)
1553						OPTSET(IN6P_MTU);
1554					break;
1555
1556				case IPV6_V6ONLY:
1557					/*
1558					 * make setsockopt(IPV6_V6ONLY)
1559					 * available only prior to bind(2).
1560					 * see ipng mailing list, Jun 22 2001.
1561					 */
1562					if (in6p->inp_lport ||
1563					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1564						error = EINVAL;
1565						break;
1566					}
1567					OPTSET(IN6P_IPV6_V6ONLY);
1568					if (optval)
1569						in6p->inp_vflag &= ~INP_IPV4;
1570					else
1571						in6p->inp_vflag |= INP_IPV4;
1572					break;
1573				case IPV6_RECVTCLASS:
1574					/* cannot mix with RFC2292 XXX */
1575					if (OPTBIT(IN6P_RFC2292)) {
1576						error = EINVAL;
1577						break;
1578					}
1579					OPTSET(IN6P_TCLASS);
1580					break;
1581				case IPV6_AUTOFLOWLABEL:
1582					OPTSET(IN6P_AUTOFLOWLABEL);
1583					break;
1584
1585				case IPV6_BINDANY:
1586					OPTSET(INP_BINDANY);
1587					break;
1588				}
1589				break;
1590
1591			case IPV6_TCLASS:
1592			case IPV6_DONTFRAG:
1593			case IPV6_USE_MIN_MTU:
1594			case IPV6_PREFER_TEMPADDR:
1595				if (optlen != sizeof(optval)) {
1596					error = EINVAL;
1597					break;
1598				}
1599				error = sooptcopyin(sopt, &optval,
1600					sizeof optval, sizeof optval);
1601				if (error)
1602					break;
1603				{
1604					struct ip6_pktopts **optp;
1605					optp = &in6p->in6p_outputopts;
1606					error = ip6_pcbopt(optname,
1607					    (u_char *)&optval, sizeof(optval),
1608					    optp, (td != NULL) ? td->td_ucred :
1609					    NULL, uproto);
1610					break;
1611				}
1612
1613			case IPV6_2292PKTINFO:
1614			case IPV6_2292HOPLIMIT:
1615			case IPV6_2292HOPOPTS:
1616			case IPV6_2292DSTOPTS:
1617			case IPV6_2292RTHDR:
1618				/* RFC 2292 */
1619				if (optlen != sizeof(int)) {
1620					error = EINVAL;
1621					break;
1622				}
1623				error = sooptcopyin(sopt, &optval,
1624					sizeof optval, sizeof optval);
1625				if (error)
1626					break;
1627				switch (optname) {
1628				case IPV6_2292PKTINFO:
1629					OPTSET2292(IN6P_PKTINFO);
1630					break;
1631				case IPV6_2292HOPLIMIT:
1632					OPTSET2292(IN6P_HOPLIMIT);
1633					break;
1634				case IPV6_2292HOPOPTS:
1635					/*
1636					 * Check super-user privilege.
1637					 * See comments for IPV6_RECVHOPOPTS.
1638					 */
1639					if (td != NULL) {
1640						error = priv_check(td,
1641						    PRIV_NETINET_SETHDROPTS);
1642						if (error)
1643							return (error);
1644					}
1645					OPTSET2292(IN6P_HOPOPTS);
1646					break;
1647				case IPV6_2292DSTOPTS:
1648					if (td != NULL) {
1649						error = priv_check(td,
1650						    PRIV_NETINET_SETHDROPTS);
1651						if (error)
1652							return (error);
1653					}
1654					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1655					break;
1656				case IPV6_2292RTHDR:
1657					OPTSET2292(IN6P_RTHDR);
1658					break;
1659				}
1660				break;
1661			case IPV6_PKTINFO:
1662			case IPV6_HOPOPTS:
1663			case IPV6_RTHDR:
1664			case IPV6_DSTOPTS:
1665			case IPV6_RTHDRDSTOPTS:
1666			case IPV6_NEXTHOP:
1667			{
1668				/* new advanced API (RFC3542) */
1669				u_char *optbuf;
1670				u_char optbuf_storage[MCLBYTES];
1671				int optlen;
1672				struct ip6_pktopts **optp;
1673
1674				/* cannot mix with RFC2292 */
1675				if (OPTBIT(IN6P_RFC2292)) {
1676					error = EINVAL;
1677					break;
1678				}
1679
1680				/*
1681				 * We only ensure valsize is not too large
1682				 * here.  Further validation will be done
1683				 * later.
1684				 */
1685				error = sooptcopyin(sopt, optbuf_storage,
1686				    sizeof(optbuf_storage), 0);
1687				if (error)
1688					break;
1689				optlen = sopt->sopt_valsize;
1690				optbuf = optbuf_storage;
1691				optp = &in6p->in6p_outputopts;
1692				error = ip6_pcbopt(optname, optbuf, optlen,
1693				    optp, (td != NULL) ? td->td_ucred : NULL,
1694				    uproto);
1695				break;
1696			}
1697#undef OPTSET
1698
1699			case IPV6_MULTICAST_IF:
1700			case IPV6_MULTICAST_HOPS:
1701			case IPV6_MULTICAST_LOOP:
1702			case IPV6_JOIN_GROUP:
1703			case IPV6_LEAVE_GROUP:
1704			case IPV6_MSFILTER:
1705			case MCAST_BLOCK_SOURCE:
1706			case MCAST_UNBLOCK_SOURCE:
1707			case MCAST_JOIN_GROUP:
1708			case MCAST_LEAVE_GROUP:
1709			case MCAST_JOIN_SOURCE_GROUP:
1710			case MCAST_LEAVE_SOURCE_GROUP:
1711				error = ip6_setmoptions(in6p, sopt);
1712				break;
1713
1714			case IPV6_PORTRANGE:
1715				error = sooptcopyin(sopt, &optval,
1716				    sizeof optval, sizeof optval);
1717				if (error)
1718					break;
1719
1720				INP_WLOCK(in6p);
1721				switch (optval) {
1722				case IPV6_PORTRANGE_DEFAULT:
1723					in6p->inp_flags &= ~(INP_LOWPORT);
1724					in6p->inp_flags &= ~(INP_HIGHPORT);
1725					break;
1726
1727				case IPV6_PORTRANGE_HIGH:
1728					in6p->inp_flags &= ~(INP_LOWPORT);
1729					in6p->inp_flags |= INP_HIGHPORT;
1730					break;
1731
1732				case IPV6_PORTRANGE_LOW:
1733					in6p->inp_flags &= ~(INP_HIGHPORT);
1734					in6p->inp_flags |= INP_LOWPORT;
1735					break;
1736
1737				default:
1738					error = EINVAL;
1739					break;
1740				}
1741				INP_WUNLOCK(in6p);
1742				break;
1743
1744#ifdef IPSEC
1745			case IPV6_IPSEC_POLICY:
1746			{
1747				caddr_t req;
1748				struct mbuf *m;
1749
1750				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1751					break;
1752				if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1753					break;
1754				req = mtod(m, caddr_t);
1755				error = ipsec_set_policy(in6p, optname, req,
1756				    m->m_len, (sopt->sopt_td != NULL) ?
1757				    sopt->sopt_td->td_ucred : NULL);
1758				m_freem(m);
1759				break;
1760			}
1761#endif /* IPSEC */
1762
1763			default:
1764				error = ENOPROTOOPT;
1765				break;
1766			}
1767			break;
1768
1769		case SOPT_GET:
1770			switch (optname) {
1771
1772			case IPV6_2292PKTOPTIONS:
1773#ifdef IPV6_PKTOPTIONS
1774			case IPV6_PKTOPTIONS:
1775#endif
1776				/*
1777				 * RFC3542 (effectively) deprecated the
1778				 * semantics of the 2292-style pktoptions.
1779				 * Since it was not reliable in nature (i.e.,
1780				 * applications had to expect the lack of some
1781				 * information after all), it would make sense
1782				 * to simplify this part by always returning
1783				 * empty data.
1784				 */
1785				sopt->sopt_valsize = 0;
1786				break;
1787
1788			case IPV6_RECVHOPOPTS:
1789			case IPV6_RECVDSTOPTS:
1790			case IPV6_RECVRTHDRDSTOPTS:
1791			case IPV6_UNICAST_HOPS:
1792			case IPV6_RECVPKTINFO:
1793			case IPV6_RECVHOPLIMIT:
1794			case IPV6_RECVRTHDR:
1795			case IPV6_RECVPATHMTU:
1796
1797			case IPV6_FAITH:
1798			case IPV6_V6ONLY:
1799			case IPV6_PORTRANGE:
1800			case IPV6_RECVTCLASS:
1801			case IPV6_AUTOFLOWLABEL:
1802			case IPV6_BINDANY:
1803				switch (optname) {
1804
1805				case IPV6_RECVHOPOPTS:
1806					optval = OPTBIT(IN6P_HOPOPTS);
1807					break;
1808
1809				case IPV6_RECVDSTOPTS:
1810					optval = OPTBIT(IN6P_DSTOPTS);
1811					break;
1812
1813				case IPV6_RECVRTHDRDSTOPTS:
1814					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1815					break;
1816
1817				case IPV6_UNICAST_HOPS:
1818					optval = in6p->in6p_hops;
1819					break;
1820
1821				case IPV6_RECVPKTINFO:
1822					optval = OPTBIT(IN6P_PKTINFO);
1823					break;
1824
1825				case IPV6_RECVHOPLIMIT:
1826					optval = OPTBIT(IN6P_HOPLIMIT);
1827					break;
1828
1829				case IPV6_RECVRTHDR:
1830					optval = OPTBIT(IN6P_RTHDR);
1831					break;
1832
1833				case IPV6_RECVPATHMTU:
1834					optval = OPTBIT(IN6P_MTU);
1835					break;
1836
1837				case IPV6_FAITH:
1838					optval = OPTBIT(INP_FAITH);
1839					break;
1840
1841				case IPV6_V6ONLY:
1842					optval = OPTBIT(IN6P_IPV6_V6ONLY);
1843					break;
1844
1845				case IPV6_PORTRANGE:
1846				    {
1847					int flags;
1848					flags = in6p->inp_flags;
1849					if (flags & INP_HIGHPORT)
1850						optval = IPV6_PORTRANGE_HIGH;
1851					else if (flags & INP_LOWPORT)
1852						optval = IPV6_PORTRANGE_LOW;
1853					else
1854						optval = 0;
1855					break;
1856				    }
1857				case IPV6_RECVTCLASS:
1858					optval = OPTBIT(IN6P_TCLASS);
1859					break;
1860
1861				case IPV6_AUTOFLOWLABEL:
1862					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1863					break;
1864
1865				case IPV6_BINDANY:
1866					optval = OPTBIT(INP_BINDANY);
1867					break;
1868				}
1869				if (error)
1870					break;
1871				error = sooptcopyout(sopt, &optval,
1872					sizeof optval);
1873				break;
1874
1875			case IPV6_PATHMTU:
1876			{
1877				u_long pmtu = 0;
1878				struct ip6_mtuinfo mtuinfo;
1879				struct route_in6 sro;
1880
1881				bzero(&sro, sizeof(sro));
1882
1883				if (!(so->so_state & SS_ISCONNECTED))
1884					return (ENOTCONN);
1885				/*
1886				 * XXX: we dot not consider the case of source
1887				 * routing, or optional information to specify
1888				 * the outgoing interface.
1889				 */
1890				error = ip6_getpmtu(&sro, NULL, NULL,
1891				    &in6p->in6p_faddr, &pmtu, NULL,
1892				    so->so_fibnum);
1893				if (sro.ro_rt)
1894					RTFREE(sro.ro_rt);
1895				if (error)
1896					break;
1897				if (pmtu > IPV6_MAXPACKET)
1898					pmtu = IPV6_MAXPACKET;
1899
1900				bzero(&mtuinfo, sizeof(mtuinfo));
1901				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1902				optdata = (void *)&mtuinfo;
1903				optdatalen = sizeof(mtuinfo);
1904				error = sooptcopyout(sopt, optdata,
1905				    optdatalen);
1906				break;
1907			}
1908
1909			case IPV6_2292PKTINFO:
1910			case IPV6_2292HOPLIMIT:
1911			case IPV6_2292HOPOPTS:
1912			case IPV6_2292RTHDR:
1913			case IPV6_2292DSTOPTS:
1914				switch (optname) {
1915				case IPV6_2292PKTINFO:
1916					optval = OPTBIT(IN6P_PKTINFO);
1917					break;
1918				case IPV6_2292HOPLIMIT:
1919					optval = OPTBIT(IN6P_HOPLIMIT);
1920					break;
1921				case IPV6_2292HOPOPTS:
1922					optval = OPTBIT(IN6P_HOPOPTS);
1923					break;
1924				case IPV6_2292RTHDR:
1925					optval = OPTBIT(IN6P_RTHDR);
1926					break;
1927				case IPV6_2292DSTOPTS:
1928					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1929					break;
1930				}
1931				error = sooptcopyout(sopt, &optval,
1932				    sizeof optval);
1933				break;
1934			case IPV6_PKTINFO:
1935			case IPV6_HOPOPTS:
1936			case IPV6_RTHDR:
1937			case IPV6_DSTOPTS:
1938			case IPV6_RTHDRDSTOPTS:
1939			case IPV6_NEXTHOP:
1940			case IPV6_TCLASS:
1941			case IPV6_DONTFRAG:
1942			case IPV6_USE_MIN_MTU:
1943			case IPV6_PREFER_TEMPADDR:
1944				error = ip6_getpcbopt(in6p->in6p_outputopts,
1945				    optname, sopt);
1946				break;
1947
1948			case IPV6_MULTICAST_IF:
1949			case IPV6_MULTICAST_HOPS:
1950			case IPV6_MULTICAST_LOOP:
1951			case IPV6_MSFILTER:
1952				error = ip6_getmoptions(in6p, sopt);
1953				break;
1954
1955#ifdef IPSEC
1956			case IPV6_IPSEC_POLICY:
1957			  {
1958				caddr_t req = NULL;
1959				size_t len = 0;
1960				struct mbuf *m = NULL;
1961				struct mbuf **mp = &m;
1962				size_t ovalsize = sopt->sopt_valsize;
1963				caddr_t oval = (caddr_t)sopt->sopt_val;
1964
1965				error = soopt_getm(sopt, &m); /* XXX */
1966				if (error != 0)
1967					break;
1968				error = soopt_mcopyin(sopt, m); /* XXX */
1969				if (error != 0)
1970					break;
1971				sopt->sopt_valsize = ovalsize;
1972				sopt->sopt_val = oval;
1973				if (m) {
1974					req = mtod(m, caddr_t);
1975					len = m->m_len;
1976				}
1977				error = ipsec_get_policy(in6p, req, len, mp);
1978				if (error == 0)
1979					error = soopt_mcopyout(sopt, m); /* XXX */
1980				if (error == 0 && m)
1981					m_freem(m);
1982				break;
1983			  }
1984#endif /* IPSEC */
1985
1986			default:
1987				error = ENOPROTOOPT;
1988				break;
1989			}
1990			break;
1991		}
1992	}
1993	return (error);
1994}
1995
1996int
1997ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
1998{
1999	int error = 0, optval, optlen;
2000	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2001	struct inpcb *in6p = sotoinpcb(so);
2002	int level, op, optname;
2003
2004	level = sopt->sopt_level;
2005	op = sopt->sopt_dir;
2006	optname = sopt->sopt_name;
2007	optlen = sopt->sopt_valsize;
2008
2009	if (level != IPPROTO_IPV6) {
2010		return (EINVAL);
2011	}
2012
2013	switch (optname) {
2014	case IPV6_CHECKSUM:
2015		/*
2016		 * For ICMPv6 sockets, no modification allowed for checksum
2017		 * offset, permit "no change" values to help existing apps.
2018		 *
2019		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2020		 * for an ICMPv6 socket will fail."
2021		 * The current behavior does not meet RFC3542.
2022		 */
2023		switch (op) {
2024		case SOPT_SET:
2025			if (optlen != sizeof(int)) {
2026				error = EINVAL;
2027				break;
2028			}
2029			error = sooptcopyin(sopt, &optval, sizeof(optval),
2030					    sizeof(optval));
2031			if (error)
2032				break;
2033			if ((optval % 2) != 0) {
2034				/* the API assumes even offset values */
2035				error = EINVAL;
2036			} else if (so->so_proto->pr_protocol ==
2037			    IPPROTO_ICMPV6) {
2038				if (optval != icmp6off)
2039					error = EINVAL;
2040			} else
2041				in6p->in6p_cksum = optval;
2042			break;
2043
2044		case SOPT_GET:
2045			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2046				optval = icmp6off;
2047			else
2048				optval = in6p->in6p_cksum;
2049
2050			error = sooptcopyout(sopt, &optval, sizeof(optval));
2051			break;
2052
2053		default:
2054			error = EINVAL;
2055			break;
2056		}
2057		break;
2058
2059	default:
2060		error = ENOPROTOOPT;
2061		break;
2062	}
2063
2064	return (error);
2065}
2066
2067/*
2068 * Set up IP6 options in pcb for insertion in output packets or
2069 * specifying behavior of outgoing packets.
2070 */
2071static int
2072ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2073    struct socket *so, struct sockopt *sopt)
2074{
2075	struct ip6_pktopts *opt = *pktopt;
2076	int error = 0;
2077	struct thread *td = sopt->sopt_td;
2078
2079	/* turn off any old options. */
2080	if (opt) {
2081#ifdef DIAGNOSTIC
2082		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2083		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2084		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2085			printf("ip6_pcbopts: all specified options are cleared.\n");
2086#endif
2087		ip6_clearpktopts(opt, -1);
2088	} else
2089		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2090	*pktopt = NULL;
2091
2092	if (!m || m->m_len == 0) {
2093		/*
2094		 * Only turning off any previous options, regardless of
2095		 * whether the opt is just created or given.
2096		 */
2097		free(opt, M_IP6OPT);
2098		return (0);
2099	}
2100
2101	/*  set options specified by user. */
2102	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2103	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2104		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2105		free(opt, M_IP6OPT);
2106		return (error);
2107	}
2108	*pktopt = opt;
2109	return (0);
2110}
2111
2112/*
2113 * initialize ip6_pktopts.  beware that there are non-zero default values in
2114 * the struct.
2115 */
2116void
2117ip6_initpktopts(struct ip6_pktopts *opt)
2118{
2119
2120	bzero(opt, sizeof(*opt));
2121	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2122	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2123	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2124	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2125}
2126
2127static int
2128ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2129    struct ucred *cred, int uproto)
2130{
2131	struct ip6_pktopts *opt;
2132
2133	if (*pktopt == NULL) {
2134		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2135		    M_WAITOK);
2136		ip6_initpktopts(*pktopt);
2137	}
2138	opt = *pktopt;
2139
2140	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2141}
2142
2143static int
2144ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2145{
2146	void *optdata = NULL;
2147	int optdatalen = 0;
2148	struct ip6_ext *ip6e;
2149	int error = 0;
2150	struct in6_pktinfo null_pktinfo;
2151	int deftclass = 0, on;
2152	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2153	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2154
2155	switch (optname) {
2156	case IPV6_PKTINFO:
2157		if (pktopt && pktopt->ip6po_pktinfo)
2158			optdata = (void *)pktopt->ip6po_pktinfo;
2159		else {
2160			/* XXX: we don't have to do this every time... */
2161			bzero(&null_pktinfo, sizeof(null_pktinfo));
2162			optdata = (void *)&null_pktinfo;
2163		}
2164		optdatalen = sizeof(struct in6_pktinfo);
2165		break;
2166	case IPV6_TCLASS:
2167		if (pktopt && pktopt->ip6po_tclass >= 0)
2168			optdata = (void *)&pktopt->ip6po_tclass;
2169		else
2170			optdata = (void *)&deftclass;
2171		optdatalen = sizeof(int);
2172		break;
2173	case IPV6_HOPOPTS:
2174		if (pktopt && pktopt->ip6po_hbh) {
2175			optdata = (void *)pktopt->ip6po_hbh;
2176			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2177			optdatalen = (ip6e->ip6e_len + 1) << 3;
2178		}
2179		break;
2180	case IPV6_RTHDR:
2181		if (pktopt && pktopt->ip6po_rthdr) {
2182			optdata = (void *)pktopt->ip6po_rthdr;
2183			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2184			optdatalen = (ip6e->ip6e_len + 1) << 3;
2185		}
2186		break;
2187	case IPV6_RTHDRDSTOPTS:
2188		if (pktopt && pktopt->ip6po_dest1) {
2189			optdata = (void *)pktopt->ip6po_dest1;
2190			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2191			optdatalen = (ip6e->ip6e_len + 1) << 3;
2192		}
2193		break;
2194	case IPV6_DSTOPTS:
2195		if (pktopt && pktopt->ip6po_dest2) {
2196			optdata = (void *)pktopt->ip6po_dest2;
2197			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2198			optdatalen = (ip6e->ip6e_len + 1) << 3;
2199		}
2200		break;
2201	case IPV6_NEXTHOP:
2202		if (pktopt && pktopt->ip6po_nexthop) {
2203			optdata = (void *)pktopt->ip6po_nexthop;
2204			optdatalen = pktopt->ip6po_nexthop->sa_len;
2205		}
2206		break;
2207	case IPV6_USE_MIN_MTU:
2208		if (pktopt)
2209			optdata = (void *)&pktopt->ip6po_minmtu;
2210		else
2211			optdata = (void *)&defminmtu;
2212		optdatalen = sizeof(int);
2213		break;
2214	case IPV6_DONTFRAG:
2215		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2216			on = 1;
2217		else
2218			on = 0;
2219		optdata = (void *)&on;
2220		optdatalen = sizeof(on);
2221		break;
2222	case IPV6_PREFER_TEMPADDR:
2223		if (pktopt)
2224			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2225		else
2226			optdata = (void *)&defpreftemp;
2227		optdatalen = sizeof(int);
2228		break;
2229	default:		/* should not happen */
2230#ifdef DIAGNOSTIC
2231		panic("ip6_getpcbopt: unexpected option\n");
2232#endif
2233		return (ENOPROTOOPT);
2234	}
2235
2236	error = sooptcopyout(sopt, optdata, optdatalen);
2237
2238	return (error);
2239}
2240
2241void
2242ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2243{
2244	if (pktopt == NULL)
2245		return;
2246
2247	if (optname == -1 || optname == IPV6_PKTINFO) {
2248		if (pktopt->ip6po_pktinfo)
2249			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2250		pktopt->ip6po_pktinfo = NULL;
2251	}
2252	if (optname == -1 || optname == IPV6_HOPLIMIT)
2253		pktopt->ip6po_hlim = -1;
2254	if (optname == -1 || optname == IPV6_TCLASS)
2255		pktopt->ip6po_tclass = -1;
2256	if (optname == -1 || optname == IPV6_NEXTHOP) {
2257		if (pktopt->ip6po_nextroute.ro_rt) {
2258			RTFREE(pktopt->ip6po_nextroute.ro_rt);
2259			pktopt->ip6po_nextroute.ro_rt = NULL;
2260		}
2261		if (pktopt->ip6po_nexthop)
2262			free(pktopt->ip6po_nexthop, M_IP6OPT);
2263		pktopt->ip6po_nexthop = NULL;
2264	}
2265	if (optname == -1 || optname == IPV6_HOPOPTS) {
2266		if (pktopt->ip6po_hbh)
2267			free(pktopt->ip6po_hbh, M_IP6OPT);
2268		pktopt->ip6po_hbh = NULL;
2269	}
2270	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2271		if (pktopt->ip6po_dest1)
2272			free(pktopt->ip6po_dest1, M_IP6OPT);
2273		pktopt->ip6po_dest1 = NULL;
2274	}
2275	if (optname == -1 || optname == IPV6_RTHDR) {
2276		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2277			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2278		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2279		if (pktopt->ip6po_route.ro_rt) {
2280			RTFREE(pktopt->ip6po_route.ro_rt);
2281			pktopt->ip6po_route.ro_rt = NULL;
2282		}
2283	}
2284	if (optname == -1 || optname == IPV6_DSTOPTS) {
2285		if (pktopt->ip6po_dest2)
2286			free(pktopt->ip6po_dest2, M_IP6OPT);
2287		pktopt->ip6po_dest2 = NULL;
2288	}
2289}
2290
2291#define PKTOPT_EXTHDRCPY(type) \
2292do {\
2293	if (src->type) {\
2294		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2295		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2296		if (dst->type == NULL && canwait == M_NOWAIT)\
2297			goto bad;\
2298		bcopy(src->type, dst->type, hlen);\
2299	}\
2300} while (/*CONSTCOND*/ 0)
2301
2302static int
2303copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2304{
2305	if (dst == NULL || src == NULL)  {
2306		printf("ip6_clearpktopts: invalid argument\n");
2307		return (EINVAL);
2308	}
2309
2310	dst->ip6po_hlim = src->ip6po_hlim;
2311	dst->ip6po_tclass = src->ip6po_tclass;
2312	dst->ip6po_flags = src->ip6po_flags;
2313	dst->ip6po_minmtu = src->ip6po_minmtu;
2314	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2315	if (src->ip6po_pktinfo) {
2316		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2317		    M_IP6OPT, canwait);
2318		if (dst->ip6po_pktinfo == NULL)
2319			goto bad;
2320		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2321	}
2322	if (src->ip6po_nexthop) {
2323		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2324		    M_IP6OPT, canwait);
2325		if (dst->ip6po_nexthop == NULL)
2326			goto bad;
2327		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2328		    src->ip6po_nexthop->sa_len);
2329	}
2330	PKTOPT_EXTHDRCPY(ip6po_hbh);
2331	PKTOPT_EXTHDRCPY(ip6po_dest1);
2332	PKTOPT_EXTHDRCPY(ip6po_dest2);
2333	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2334	return (0);
2335
2336  bad:
2337	ip6_clearpktopts(dst, -1);
2338	return (ENOBUFS);
2339}
2340#undef PKTOPT_EXTHDRCPY
2341
2342struct ip6_pktopts *
2343ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2344{
2345	int error;
2346	struct ip6_pktopts *dst;
2347
2348	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2349	if (dst == NULL)
2350		return (NULL);
2351	ip6_initpktopts(dst);
2352
2353	if ((error = copypktopts(dst, src, canwait)) != 0) {
2354		free(dst, M_IP6OPT);
2355		return (NULL);
2356	}
2357
2358	return (dst);
2359}
2360
2361void
2362ip6_freepcbopts(struct ip6_pktopts *pktopt)
2363{
2364	if (pktopt == NULL)
2365		return;
2366
2367	ip6_clearpktopts(pktopt, -1);
2368
2369	free(pktopt, M_IP6OPT);
2370}
2371
2372/*
2373 * Set IPv6 outgoing packet options based on advanced API.
2374 */
2375int
2376ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2377    struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2378{
2379	struct cmsghdr *cm = 0;
2380
2381	if (control == NULL || opt == NULL)
2382		return (EINVAL);
2383
2384	ip6_initpktopts(opt);
2385	if (stickyopt) {
2386		int error;
2387
2388		/*
2389		 * If stickyopt is provided, make a local copy of the options
2390		 * for this particular packet, then override them by ancillary
2391		 * objects.
2392		 * XXX: copypktopts() does not copy the cached route to a next
2393		 * hop (if any).  This is not very good in terms of efficiency,
2394		 * but we can allow this since this option should be rarely
2395		 * used.
2396		 */
2397		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2398			return (error);
2399	}
2400
2401	/*
2402	 * XXX: Currently, we assume all the optional information is stored
2403	 * in a single mbuf.
2404	 */
2405	if (control->m_next)
2406		return (EINVAL);
2407
2408	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2409	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2410		int error;
2411
2412		if (control->m_len < CMSG_LEN(0))
2413			return (EINVAL);
2414
2415		cm = mtod(control, struct cmsghdr *);
2416		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2417			return (EINVAL);
2418		if (cm->cmsg_level != IPPROTO_IPV6)
2419			continue;
2420
2421		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2422		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2423		if (error)
2424			return (error);
2425	}
2426
2427	return (0);
2428}
2429
2430/*
2431 * Set a particular packet option, as a sticky option or an ancillary data
2432 * item.  "len" can be 0 only when it's a sticky option.
2433 * We have 4 cases of combination of "sticky" and "cmsg":
2434 * "sticky=0, cmsg=0": impossible
2435 * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2436 * "sticky=1, cmsg=0": RFC3542 socket option
2437 * "sticky=1, cmsg=1": RFC2292 socket option
2438 */
2439static int
2440ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2441    struct ucred *cred, int sticky, int cmsg, int uproto)
2442{
2443	int minmtupolicy, preftemp;
2444	int error;
2445
2446	if (!sticky && !cmsg) {
2447#ifdef DIAGNOSTIC
2448		printf("ip6_setpktopt: impossible case\n");
2449#endif
2450		return (EINVAL);
2451	}
2452
2453	/*
2454	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2455	 * not be specified in the context of RFC3542.  Conversely,
2456	 * RFC3542 types should not be specified in the context of RFC2292.
2457	 */
2458	if (!cmsg) {
2459		switch (optname) {
2460		case IPV6_2292PKTINFO:
2461		case IPV6_2292HOPLIMIT:
2462		case IPV6_2292NEXTHOP:
2463		case IPV6_2292HOPOPTS:
2464		case IPV6_2292DSTOPTS:
2465		case IPV6_2292RTHDR:
2466		case IPV6_2292PKTOPTIONS:
2467			return (ENOPROTOOPT);
2468		}
2469	}
2470	if (sticky && cmsg) {
2471		switch (optname) {
2472		case IPV6_PKTINFO:
2473		case IPV6_HOPLIMIT:
2474		case IPV6_NEXTHOP:
2475		case IPV6_HOPOPTS:
2476		case IPV6_DSTOPTS:
2477		case IPV6_RTHDRDSTOPTS:
2478		case IPV6_RTHDR:
2479		case IPV6_USE_MIN_MTU:
2480		case IPV6_DONTFRAG:
2481		case IPV6_TCLASS:
2482		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2483			return (ENOPROTOOPT);
2484		}
2485	}
2486
2487	switch (optname) {
2488	case IPV6_2292PKTINFO:
2489	case IPV6_PKTINFO:
2490	{
2491		struct ifnet *ifp = NULL;
2492		struct in6_pktinfo *pktinfo;
2493
2494		if (len != sizeof(struct in6_pktinfo))
2495			return (EINVAL);
2496
2497		pktinfo = (struct in6_pktinfo *)buf;
2498
2499		/*
2500		 * An application can clear any sticky IPV6_PKTINFO option by
2501		 * doing a "regular" setsockopt with ipi6_addr being
2502		 * in6addr_any and ipi6_ifindex being zero.
2503		 * [RFC 3542, Section 6]
2504		 */
2505		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2506		    pktinfo->ipi6_ifindex == 0 &&
2507		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2508			ip6_clearpktopts(opt, optname);
2509			break;
2510		}
2511
2512		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2513		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2514			return (EINVAL);
2515		}
2516
2517		/* validate the interface index if specified. */
2518		if (pktinfo->ipi6_ifindex > V_if_index ||
2519		    pktinfo->ipi6_ifindex < 0) {
2520			 return (ENXIO);
2521		}
2522		if (pktinfo->ipi6_ifindex) {
2523			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2524			if (ifp == NULL)
2525				return (ENXIO);
2526		}
2527
2528		/*
2529		 * We store the address anyway, and let in6_selectsrc()
2530		 * validate the specified address.  This is because ipi6_addr
2531		 * may not have enough information about its scope zone, and
2532		 * we may need additional information (such as outgoing
2533		 * interface or the scope zone of a destination address) to
2534		 * disambiguate the scope.
2535		 * XXX: the delay of the validation may confuse the
2536		 * application when it is used as a sticky option.
2537		 */
2538		if (opt->ip6po_pktinfo == NULL) {
2539			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2540			    M_IP6OPT, M_NOWAIT);
2541			if (opt->ip6po_pktinfo == NULL)
2542				return (ENOBUFS);
2543		}
2544		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2545		break;
2546	}
2547
2548	case IPV6_2292HOPLIMIT:
2549	case IPV6_HOPLIMIT:
2550	{
2551		int *hlimp;
2552
2553		/*
2554		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2555		 * to simplify the ordering among hoplimit options.
2556		 */
2557		if (optname == IPV6_HOPLIMIT && sticky)
2558			return (ENOPROTOOPT);
2559
2560		if (len != sizeof(int))
2561			return (EINVAL);
2562		hlimp = (int *)buf;
2563		if (*hlimp < -1 || *hlimp > 255)
2564			return (EINVAL);
2565
2566		opt->ip6po_hlim = *hlimp;
2567		break;
2568	}
2569
2570	case IPV6_TCLASS:
2571	{
2572		int tclass;
2573
2574		if (len != sizeof(int))
2575			return (EINVAL);
2576		tclass = *(int *)buf;
2577		if (tclass < -1 || tclass > 255)
2578			return (EINVAL);
2579
2580		opt->ip6po_tclass = tclass;
2581		break;
2582	}
2583
2584	case IPV6_2292NEXTHOP:
2585	case IPV6_NEXTHOP:
2586		if (cred != NULL) {
2587			error = priv_check_cred(cred,
2588			    PRIV_NETINET_SETHDROPTS, 0);
2589			if (error)
2590				return (error);
2591		}
2592
2593		if (len == 0) {	/* just remove the option */
2594			ip6_clearpktopts(opt, IPV6_NEXTHOP);
2595			break;
2596		}
2597
2598		/* check if cmsg_len is large enough for sa_len */
2599		if (len < sizeof(struct sockaddr) || len < *buf)
2600			return (EINVAL);
2601
2602		switch (((struct sockaddr *)buf)->sa_family) {
2603		case AF_INET6:
2604		{
2605			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2606			int error;
2607
2608			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2609				return (EINVAL);
2610
2611			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2612			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2613				return (EINVAL);
2614			}
2615			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2616			    != 0) {
2617				return (error);
2618			}
2619			break;
2620		}
2621		case AF_LINK:	/* should eventually be supported */
2622		default:
2623			return (EAFNOSUPPORT);
2624		}
2625
2626		/* turn off the previous option, then set the new option. */
2627		ip6_clearpktopts(opt, IPV6_NEXTHOP);
2628		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2629		if (opt->ip6po_nexthop == NULL)
2630			return (ENOBUFS);
2631		bcopy(buf, opt->ip6po_nexthop, *buf);
2632		break;
2633
2634	case IPV6_2292HOPOPTS:
2635	case IPV6_HOPOPTS:
2636	{
2637		struct ip6_hbh *hbh;
2638		int hbhlen;
2639
2640		/*
2641		 * XXX: We don't allow a non-privileged user to set ANY HbH
2642		 * options, since per-option restriction has too much
2643		 * overhead.
2644		 */
2645		if (cred != NULL) {
2646			error = priv_check_cred(cred,
2647			    PRIV_NETINET_SETHDROPTS, 0);
2648			if (error)
2649				return (error);
2650		}
2651
2652		if (len == 0) {
2653			ip6_clearpktopts(opt, IPV6_HOPOPTS);
2654			break;	/* just remove the option */
2655		}
2656
2657		/* message length validation */
2658		if (len < sizeof(struct ip6_hbh))
2659			return (EINVAL);
2660		hbh = (struct ip6_hbh *)buf;
2661		hbhlen = (hbh->ip6h_len + 1) << 3;
2662		if (len != hbhlen)
2663			return (EINVAL);
2664
2665		/* turn off the previous option, then set the new option. */
2666		ip6_clearpktopts(opt, IPV6_HOPOPTS);
2667		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2668		if (opt->ip6po_hbh == NULL)
2669			return (ENOBUFS);
2670		bcopy(hbh, opt->ip6po_hbh, hbhlen);
2671
2672		break;
2673	}
2674
2675	case IPV6_2292DSTOPTS:
2676	case IPV6_DSTOPTS:
2677	case IPV6_RTHDRDSTOPTS:
2678	{
2679		struct ip6_dest *dest, **newdest = NULL;
2680		int destlen;
2681
2682		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2683			error = priv_check_cred(cred,
2684			    PRIV_NETINET_SETHDROPTS, 0);
2685			if (error)
2686				return (error);
2687		}
2688
2689		if (len == 0) {
2690			ip6_clearpktopts(opt, optname);
2691			break;	/* just remove the option */
2692		}
2693
2694		/* message length validation */
2695		if (len < sizeof(struct ip6_dest))
2696			return (EINVAL);
2697		dest = (struct ip6_dest *)buf;
2698		destlen = (dest->ip6d_len + 1) << 3;
2699		if (len != destlen)
2700			return (EINVAL);
2701
2702		/*
2703		 * Determine the position that the destination options header
2704		 * should be inserted; before or after the routing header.
2705		 */
2706		switch (optname) {
2707		case IPV6_2292DSTOPTS:
2708			/*
2709			 * The old advacned API is ambiguous on this point.
2710			 * Our approach is to determine the position based
2711			 * according to the existence of a routing header.
2712			 * Note, however, that this depends on the order of the
2713			 * extension headers in the ancillary data; the 1st
2714			 * part of the destination options header must appear
2715			 * before the routing header in the ancillary data,
2716			 * too.
2717			 * RFC3542 solved the ambiguity by introducing
2718			 * separate ancillary data or option types.
2719			 */
2720			if (opt->ip6po_rthdr == NULL)
2721				newdest = &opt->ip6po_dest1;
2722			else
2723				newdest = &opt->ip6po_dest2;
2724			break;
2725		case IPV6_RTHDRDSTOPTS:
2726			newdest = &opt->ip6po_dest1;
2727			break;
2728		case IPV6_DSTOPTS:
2729			newdest = &opt->ip6po_dest2;
2730			break;
2731		}
2732
2733		/* turn off the previous option, then set the new option. */
2734		ip6_clearpktopts(opt, optname);
2735		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2736		if (*newdest == NULL)
2737			return (ENOBUFS);
2738		bcopy(dest, *newdest, destlen);
2739
2740		break;
2741	}
2742
2743	case IPV6_2292RTHDR:
2744	case IPV6_RTHDR:
2745	{
2746		struct ip6_rthdr *rth;
2747		int rthlen;
2748
2749		if (len == 0) {
2750			ip6_clearpktopts(opt, IPV6_RTHDR);
2751			break;	/* just remove the option */
2752		}
2753
2754		/* message length validation */
2755		if (len < sizeof(struct ip6_rthdr))
2756			return (EINVAL);
2757		rth = (struct ip6_rthdr *)buf;
2758		rthlen = (rth->ip6r_len + 1) << 3;
2759		if (len != rthlen)
2760			return (EINVAL);
2761
2762		switch (rth->ip6r_type) {
2763		case IPV6_RTHDR_TYPE_0:
2764			if (rth->ip6r_len == 0)	/* must contain one addr */
2765				return (EINVAL);
2766			if (rth->ip6r_len % 2) /* length must be even */
2767				return (EINVAL);
2768			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2769				return (EINVAL);
2770			break;
2771		default:
2772			return (EINVAL);	/* not supported */
2773		}
2774
2775		/* turn off the previous option */
2776		ip6_clearpktopts(opt, IPV6_RTHDR);
2777		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2778		if (opt->ip6po_rthdr == NULL)
2779			return (ENOBUFS);
2780		bcopy(rth, opt->ip6po_rthdr, rthlen);
2781
2782		break;
2783	}
2784
2785	case IPV6_USE_MIN_MTU:
2786		if (len != sizeof(int))
2787			return (EINVAL);
2788		minmtupolicy = *(int *)buf;
2789		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2790		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
2791		    minmtupolicy != IP6PO_MINMTU_ALL) {
2792			return (EINVAL);
2793		}
2794		opt->ip6po_minmtu = minmtupolicy;
2795		break;
2796
2797	case IPV6_DONTFRAG:
2798		if (len != sizeof(int))
2799			return (EINVAL);
2800
2801		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2802			/*
2803			 * we ignore this option for TCP sockets.
2804			 * (RFC3542 leaves this case unspecified.)
2805			 */
2806			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2807		} else
2808			opt->ip6po_flags |= IP6PO_DONTFRAG;
2809		break;
2810
2811	case IPV6_PREFER_TEMPADDR:
2812		if (len != sizeof(int))
2813			return (EINVAL);
2814		preftemp = *(int *)buf;
2815		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2816		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2817		    preftemp != IP6PO_TEMPADDR_PREFER) {
2818			return (EINVAL);
2819		}
2820		opt->ip6po_prefer_tempaddr = preftemp;
2821		break;
2822
2823	default:
2824		return (ENOPROTOOPT);
2825	} /* end of switch */
2826
2827	return (0);
2828}
2829
2830/*
2831 * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2832 * packet to the input queue of a specified interface.  Note that this
2833 * calls the output routine of the loopback "driver", but with an interface
2834 * pointer that might NOT be &loif -- easier than replicating that code here.
2835 */
2836void
2837ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2838{
2839	struct mbuf *copym;
2840	struct ip6_hdr *ip6;
2841
2842	copym = m_copy(m, 0, M_COPYALL);
2843	if (copym == NULL)
2844		return;
2845
2846	/*
2847	 * Make sure to deep-copy IPv6 header portion in case the data
2848	 * is in an mbuf cluster, so that we can safely override the IPv6
2849	 * header portion later.
2850	 */
2851	if ((copym->m_flags & M_EXT) != 0 ||
2852	    copym->m_len < sizeof(struct ip6_hdr)) {
2853		copym = m_pullup(copym, sizeof(struct ip6_hdr));
2854		if (copym == NULL)
2855			return;
2856	}
2857	ip6 = mtod(copym, struct ip6_hdr *);
2858	/*
2859	 * clear embedded scope identifiers if necessary.
2860	 * in6_clearscope will touch the addresses only when necessary.
2861	 */
2862	in6_clearscope(&ip6->ip6_src);
2863	in6_clearscope(&ip6->ip6_dst);
2864	if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
2865		copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
2866		    CSUM_PSEUDO_HDR;
2867		copym->m_pkthdr.csum_data = 0xffff;
2868	}
2869	(void)if_simloop(ifp, copym, dst->sin6_family, 0);
2870}
2871
2872/*
2873 * Chop IPv6 header off from the payload.
2874 */
2875static int
2876ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
2877{
2878	struct mbuf *mh;
2879	struct ip6_hdr *ip6;
2880
2881	ip6 = mtod(m, struct ip6_hdr *);
2882	if (m->m_len > sizeof(*ip6)) {
2883		mh = m_gethdr(M_NOWAIT, MT_DATA);
2884		if (mh == NULL) {
2885			m_freem(m);
2886			return ENOBUFS;
2887		}
2888		m_move_pkthdr(mh, m);
2889		MH_ALIGN(mh, sizeof(*ip6));
2890		m->m_len -= sizeof(*ip6);
2891		m->m_data += sizeof(*ip6);
2892		mh->m_next = m;
2893		m = mh;
2894		m->m_len = sizeof(*ip6);
2895		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
2896	}
2897	exthdrs->ip6e_ip6 = m;
2898	return 0;
2899}
2900
2901/*
2902 * Compute IPv6 extension header length.
2903 */
2904int
2905ip6_optlen(struct inpcb *in6p)
2906{
2907	int len;
2908
2909	if (!in6p->in6p_outputopts)
2910		return 0;
2911
2912	len = 0;
2913#define elen(x) \
2914    (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
2915
2916	len += elen(in6p->in6p_outputopts->ip6po_hbh);
2917	if (in6p->in6p_outputopts->ip6po_rthdr)
2918		/* dest1 is valid with rthdr only */
2919		len += elen(in6p->in6p_outputopts->ip6po_dest1);
2920	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
2921	len += elen(in6p->in6p_outputopts->ip6po_dest2);
2922	return len;
2923#undef elen
2924}
2925