xref: /freebsd/sys/netinet6/ip6_output.c (revision 2f834a0b41079f9be4dc33ff877d50a5fba869d4)
1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
30  */
31 
32 /*-
33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 4. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
61  */
62 
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65 
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipfw.h"
69 #include "opt_ipsec.h"
70 #include "opt_sctp.h"
71 #include "opt_route.h"
72 #include "opt_rss.h"
73 
74 #include <sys/param.h>
75 #include <sys/kernel.h>
76 #include <sys/malloc.h>
77 #include <sys/mbuf.h>
78 #include <sys/errno.h>
79 #include <sys/priv.h>
80 #include <sys/proc.h>
81 #include <sys/protosw.h>
82 #include <sys/socket.h>
83 #include <sys/socketvar.h>
84 #include <sys/syslog.h>
85 #include <sys/ucred.h>
86 
87 #include <machine/in_cksum.h>
88 
89 #include <net/if.h>
90 #include <net/if_var.h>
91 #include <net/netisr.h>
92 #include <net/route.h>
93 #include <net/pfil.h>
94 #include <net/vnet.h>
95 
96 #include <netinet/in.h>
97 #include <netinet/in_var.h>
98 #include <netinet/ip_var.h>
99 #include <netinet6/in6_var.h>
100 #include <netinet/ip6.h>
101 #include <netinet/icmp6.h>
102 #include <netinet6/ip6_var.h>
103 #include <netinet/in_pcb.h>
104 #include <netinet/tcp_var.h>
105 #include <netinet6/nd6.h>
106 #include <netinet/in_rss.h>
107 
108 #ifdef IPSEC
109 #include <netipsec/ipsec.h>
110 #include <netipsec/ipsec6.h>
111 #include <netipsec/key.h>
112 #include <netinet6/ip6_ipsec.h>
113 #endif /* IPSEC */
114 #ifdef SCTP
115 #include <netinet/sctp.h>
116 #include <netinet/sctp_crc32.h>
117 #endif
118 
119 #include <netinet6/ip6protosw.h>
120 #include <netinet6/scope6_var.h>
121 
122 #ifdef FLOWTABLE
123 #include <net/flowtable.h>
124 #endif
125 
126 extern int in6_mcast_loop;
127 
128 struct ip6_exthdrs {
129 	struct mbuf *ip6e_ip6;
130 	struct mbuf *ip6e_hbh;
131 	struct mbuf *ip6e_dest1;
132 	struct mbuf *ip6e_rthdr;
133 	struct mbuf *ip6e_dest2;
134 };
135 
136 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
137 			   struct ucred *, int);
138 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
139 	struct socket *, struct sockopt *);
140 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
141 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
142 	struct ucred *, int, int, int);
143 
144 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
145 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
146 	struct ip6_frag **);
147 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
148 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
149 static int ip6_getpmtu(struct route_in6 *, struct route_in6 *,
150 	struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
151 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
152 
153 
154 /*
155  * Make an extension header from option data.  hp is the source, and
156  * mp is the destination.
157  */
158 #define MAKE_EXTHDR(hp, mp)						\
159     do {								\
160 	if (hp) {							\
161 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
162 		error = ip6_copyexthdr((mp), (caddr_t)(hp),		\
163 		    ((eh)->ip6e_len + 1) << 3);				\
164 		if (error)						\
165 			goto freehdrs;					\
166 	}								\
167     } while (/*CONSTCOND*/ 0)
168 
169 /*
170  * Form a chain of extension headers.
171  * m is the extension header mbuf
172  * mp is the previous mbuf in the chain
173  * p is the next header
174  * i is the type of option.
175  */
176 #define MAKE_CHAIN(m, mp, p, i)\
177     do {\
178 	if (m) {\
179 		if (!hdrsplit) \
180 			panic("assumption failed: hdr not split"); \
181 		*mtod((m), u_char *) = *(p);\
182 		*(p) = (i);\
183 		p = mtod((m), u_char *);\
184 		(m)->m_next = (mp)->m_next;\
185 		(mp)->m_next = (m);\
186 		(mp) = (m);\
187 	}\
188     } while (/*CONSTCOND*/ 0)
189 
190 void
191 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
192 {
193 	u_short csum;
194 
195 	csum = in_cksum_skip(m, offset + plen, offset);
196 	if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
197 		csum = 0xffff;
198 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
199 
200 	if (offset + sizeof(u_short) > m->m_len) {
201 		printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
202 		    "csum_flags=%b\n", __func__, m->m_len, plen, offset,
203 		    (int)m->m_pkthdr.csum_flags, CSUM_BITS);
204 		/*
205 		 * XXX this should not happen, but if it does, the correct
206 		 * behavior may be to insert the checksum in the appropriate
207 		 * next mbuf in the chain.
208 		 */
209 		return;
210 	}
211 	*(u_short *)(m->m_data + offset) = csum;
212 }
213 
214 /*
215  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
216  * header (with pri, len, nxt, hlim, src, dst).
217  * This function may modify ver and hlim only.
218  * The mbuf chain containing the packet will be freed.
219  * The mbuf opt, if present, will not be freed.
220  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
221  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
222  * then result of route lookup is stored in ro->ro_rt.
223  *
224  * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
225  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
226  * which is rt_mtu.
227  *
228  * ifpp - XXX: just for statistics
229  */
230 /*
231  * XXX TODO: no flowid is assigned for outbound flows?
232  */
233 int
234 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
235     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
236     struct ifnet **ifpp, struct inpcb *inp)
237 {
238 	struct ip6_hdr *ip6, *mhip6;
239 	struct ifnet *ifp, *origifp;
240 	struct mbuf *m = m0;
241 	struct mbuf *mprev = NULL;
242 	int hlen, tlen, len, off;
243 	struct route_in6 ip6route;
244 	struct rtentry *rt = NULL;
245 	struct sockaddr_in6 *dst, src_sa, dst_sa;
246 	struct in6_addr odst;
247 	int error = 0;
248 	struct in6_ifaddr *ia = NULL;
249 	u_long mtu;
250 	int alwaysfrag, dontfrag;
251 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
252 	struct ip6_exthdrs exthdrs;
253 	struct in6_addr finaldst, src0, dst0;
254 	u_int32_t zone;
255 	struct route_in6 *ro_pmtu = NULL;
256 	int hdrsplit = 0;
257 	int sw_csum, tso;
258 	int needfiblookup;
259 	uint32_t fibnum;
260 	struct m_tag *fwd_tag = NULL;
261 
262 	ip6 = mtod(m, struct ip6_hdr *);
263 	if (ip6 == NULL) {
264 		printf ("ip6 is NULL");
265 		goto bad;
266 	}
267 
268 	if (inp != NULL) {
269 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
270 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
271 			/* unconditionally set flowid */
272 			m->m_pkthdr.flowid = inp->inp_flowid;
273 			M_HASHTYPE_SET(m, inp->inp_flowtype);
274 		}
275 	}
276 
277 	finaldst = ip6->ip6_dst;
278 	bzero(&exthdrs, sizeof(exthdrs));
279 	if (opt) {
280 		/* Hop-by-Hop options header */
281 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
282 		/* Destination options header(1st part) */
283 		if (opt->ip6po_rthdr) {
284 			/*
285 			 * Destination options header(1st part)
286 			 * This only makes sense with a routing header.
287 			 * See Section 9.2 of RFC 3542.
288 			 * Disabling this part just for MIP6 convenience is
289 			 * a bad idea.  We need to think carefully about a
290 			 * way to make the advanced API coexist with MIP6
291 			 * options, which might automatically be inserted in
292 			 * the kernel.
293 			 */
294 			MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
295 		}
296 		/* Routing header */
297 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
298 		/* Destination options header(2nd part) */
299 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
300 	}
301 
302 #ifdef IPSEC
303 	/*
304 	 * IPSec checking which handles several cases.
305 	 * FAST IPSEC: We re-injected the packet.
306 	 * XXX: need scope argument.
307 	 */
308 	switch(ip6_ipsec_output(&m, inp, &error))
309 	{
310 	case 1:                 /* Bad packet */
311 		goto freehdrs;
312 	case -1:                /* IPSec done */
313 		goto done;
314 	case 0:                 /* No IPSec */
315 	default:
316 		break;
317 	}
318 #endif /* IPSEC */
319 
320 	/*
321 	 * Calculate the total length of the extension header chain.
322 	 * Keep the length of the unfragmentable part for fragmentation.
323 	 */
324 	optlen = 0;
325 	if (exthdrs.ip6e_hbh)
326 		optlen += exthdrs.ip6e_hbh->m_len;
327 	if (exthdrs.ip6e_dest1)
328 		optlen += exthdrs.ip6e_dest1->m_len;
329 	if (exthdrs.ip6e_rthdr)
330 		optlen += exthdrs.ip6e_rthdr->m_len;
331 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
332 
333 	/* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
334 	if (exthdrs.ip6e_dest2)
335 		optlen += exthdrs.ip6e_dest2->m_len;
336 
337 	/*
338 	 * If there is at least one extension header,
339 	 * separate IP6 header from the payload.
340 	 */
341 	if (optlen && !hdrsplit) {
342 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
343 			m = NULL;
344 			goto freehdrs;
345 		}
346 		m = exthdrs.ip6e_ip6;
347 		hdrsplit++;
348 	}
349 
350 	/* adjust pointer */
351 	ip6 = mtod(m, struct ip6_hdr *);
352 
353 	/* adjust mbuf packet header length */
354 	m->m_pkthdr.len += optlen;
355 	plen = m->m_pkthdr.len - sizeof(*ip6);
356 
357 	/* If this is a jumbo payload, insert a jumbo payload option. */
358 	if (plen > IPV6_MAXPACKET) {
359 		if (!hdrsplit) {
360 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
361 				m = NULL;
362 				goto freehdrs;
363 			}
364 			m = exthdrs.ip6e_ip6;
365 			hdrsplit++;
366 		}
367 		/* adjust pointer */
368 		ip6 = mtod(m, struct ip6_hdr *);
369 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
370 			goto freehdrs;
371 		ip6->ip6_plen = 0;
372 	} else
373 		ip6->ip6_plen = htons(plen);
374 
375 	/*
376 	 * Concatenate headers and fill in next header fields.
377 	 * Here we have, on "m"
378 	 *	IPv6 payload
379 	 * and we insert headers accordingly.  Finally, we should be getting:
380 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
381 	 *
382 	 * during the header composing process, "m" points to IPv6 header.
383 	 * "mprev" points to an extension header prior to esp.
384 	 */
385 	u_char *nexthdrp = &ip6->ip6_nxt;
386 	mprev = m;
387 
388 	/*
389 	 * we treat dest2 specially.  this makes IPsec processing
390 	 * much easier.  the goal here is to make mprev point the
391 	 * mbuf prior to dest2.
392 	 *
393 	 * result: IPv6 dest2 payload
394 	 * m and mprev will point to IPv6 header.
395 	 */
396 	if (exthdrs.ip6e_dest2) {
397 		if (!hdrsplit)
398 			panic("assumption failed: hdr not split");
399 		exthdrs.ip6e_dest2->m_next = m->m_next;
400 		m->m_next = exthdrs.ip6e_dest2;
401 		*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
402 		ip6->ip6_nxt = IPPROTO_DSTOPTS;
403 	}
404 
405 	/*
406 	 * result: IPv6 hbh dest1 rthdr dest2 payload
407 	 * m will point to IPv6 header.  mprev will point to the
408 	 * extension header prior to dest2 (rthdr in the above case).
409 	 */
410 	MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
411 	MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
412 		   IPPROTO_DSTOPTS);
413 	MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
414 		   IPPROTO_ROUTING);
415 
416 	/*
417 	 * If there is a routing header, discard the packet.
418 	 */
419 	if (exthdrs.ip6e_rthdr) {
420 		 error = EINVAL;
421 		 goto bad;
422 	}
423 
424 	/* Source address validation */
425 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
426 	    (flags & IPV6_UNSPECSRC) == 0) {
427 		error = EOPNOTSUPP;
428 		IP6STAT_INC(ip6s_badscope);
429 		goto bad;
430 	}
431 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
432 		error = EOPNOTSUPP;
433 		IP6STAT_INC(ip6s_badscope);
434 		goto bad;
435 	}
436 
437 	IP6STAT_INC(ip6s_localout);
438 
439 	/*
440 	 * Route packet.
441 	 */
442 	if (ro == 0) {
443 		ro = &ip6route;
444 		bzero((caddr_t)ro, sizeof(*ro));
445 	}
446 	ro_pmtu = ro;
447 	if (opt && opt->ip6po_rthdr)
448 		ro = &opt->ip6po_route;
449 	dst = (struct sockaddr_in6 *)&ro->ro_dst;
450 #ifdef FLOWTABLE
451 	if (ro->ro_rt == NULL)
452 		(void )flowtable_lookup(AF_INET6, m, (struct route *)ro);
453 #endif
454 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
455 again:
456 	/*
457 	 * if specified, try to fill in the traffic class field.
458 	 * do not override if a non-zero value is already set.
459 	 * we check the diffserv field and the ecn field separately.
460 	 */
461 	if (opt && opt->ip6po_tclass >= 0) {
462 		int mask = 0;
463 
464 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
465 			mask |= 0xfc;
466 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
467 			mask |= 0x03;
468 		if (mask != 0)
469 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
470 	}
471 
472 	/* fill in or override the hop limit field, if necessary. */
473 	if (opt && opt->ip6po_hlim != -1)
474 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
475 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
476 		if (im6o != NULL)
477 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
478 		else
479 			ip6->ip6_hlim = V_ip6_defmcasthlim;
480 	}
481 
482 	/* adjust pointer */
483 	ip6 = mtod(m, struct ip6_hdr *);
484 
485 	if (ro->ro_rt && fwd_tag == NULL) {
486 		rt = ro->ro_rt;
487 		ifp = ro->ro_rt->rt_ifp;
488 	} else {
489 		if (fwd_tag == NULL) {
490 			bzero(&dst_sa, sizeof(dst_sa));
491 			dst_sa.sin6_family = AF_INET6;
492 			dst_sa.sin6_len = sizeof(dst_sa);
493 			dst_sa.sin6_addr = ip6->ip6_dst;
494 		}
495 		error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
496 		    &rt, fibnum);
497 		if (error != 0) {
498 			if (ifp != NULL)
499 				in6_ifstat_inc(ifp, ifs6_out_discard);
500 			goto bad;
501 		}
502 	}
503 	if (rt == NULL) {
504 		/*
505 		 * If in6_selectroute() does not return a route entry,
506 		 * dst may not have been updated.
507 		 */
508 		*dst = dst_sa;	/* XXX */
509 	}
510 
511 	/*
512 	 * then rt (for unicast) and ifp must be non-NULL valid values.
513 	 */
514 	if ((flags & IPV6_FORWARDING) == 0) {
515 		/* XXX: the FORWARDING flag can be set for mrouting. */
516 		in6_ifstat_inc(ifp, ifs6_out_request);
517 	}
518 	if (rt != NULL) {
519 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
520 		counter_u64_add(rt->rt_pksent, 1);
521 	}
522 
523 
524 	/*
525 	 * The outgoing interface must be in the zone of source and
526 	 * destination addresses.
527 	 */
528 	origifp = ifp;
529 
530 	src0 = ip6->ip6_src;
531 	if (in6_setscope(&src0, origifp, &zone))
532 		goto badscope;
533 	bzero(&src_sa, sizeof(src_sa));
534 	src_sa.sin6_family = AF_INET6;
535 	src_sa.sin6_len = sizeof(src_sa);
536 	src_sa.sin6_addr = ip6->ip6_src;
537 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
538 		goto badscope;
539 
540 	dst0 = ip6->ip6_dst;
541 	if (in6_setscope(&dst0, origifp, &zone))
542 		goto badscope;
543 	/* re-initialize to be sure */
544 	bzero(&dst_sa, sizeof(dst_sa));
545 	dst_sa.sin6_family = AF_INET6;
546 	dst_sa.sin6_len = sizeof(dst_sa);
547 	dst_sa.sin6_addr = ip6->ip6_dst;
548 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
549 		goto badscope;
550 	}
551 
552 	/* We should use ia_ifp to support the case of
553 	 * sending packets to an address of our own.
554 	 */
555 	if (ia != NULL && ia->ia_ifp)
556 		ifp = ia->ia_ifp;
557 
558 	/* scope check is done. */
559 	goto routefound;
560 
561   badscope:
562 	IP6STAT_INC(ip6s_badscope);
563 	in6_ifstat_inc(origifp, ifs6_out_discard);
564 	if (error == 0)
565 		error = EHOSTUNREACH; /* XXX */
566 	goto bad;
567 
568   routefound:
569 	if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
570 		if (opt && opt->ip6po_nextroute.ro_rt) {
571 			/*
572 			 * The nexthop is explicitly specified by the
573 			 * application.  We assume the next hop is an IPv6
574 			 * address.
575 			 */
576 			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
577 		}
578 		else if ((rt->rt_flags & RTF_GATEWAY))
579 			dst = (struct sockaddr_in6 *)rt->rt_gateway;
580 	}
581 
582 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
583 		m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
584 	} else {
585 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
586 		in6_ifstat_inc(ifp, ifs6_out_mcast);
587 		/*
588 		 * Confirm that the outgoing interface supports multicast.
589 		 */
590 		if (!(ifp->if_flags & IFF_MULTICAST)) {
591 			IP6STAT_INC(ip6s_noroute);
592 			in6_ifstat_inc(ifp, ifs6_out_discard);
593 			error = ENETUNREACH;
594 			goto bad;
595 		}
596 		if ((im6o == NULL && in6_mcast_loop) ||
597 		    (im6o && im6o->im6o_multicast_loop)) {
598 			/*
599 			 * Loop back multicast datagram if not expressly
600 			 * forbidden to do so, even if we have not joined
601 			 * the address; protocols will filter it later,
602 			 * thus deferring a hash lookup and lock acquisition
603 			 * at the expense of an m_copym().
604 			 */
605 			ip6_mloopback(ifp, m, dst);
606 		} else {
607 			/*
608 			 * If we are acting as a multicast router, perform
609 			 * multicast forwarding as if the packet had just
610 			 * arrived on the interface to which we are about
611 			 * to send.  The multicast forwarding function
612 			 * recursively calls this function, using the
613 			 * IPV6_FORWARDING flag to prevent infinite recursion.
614 			 *
615 			 * Multicasts that are looped back by ip6_mloopback(),
616 			 * above, will be forwarded by the ip6_input() routine,
617 			 * if necessary.
618 			 */
619 			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
620 				/*
621 				 * XXX: ip6_mforward expects that rcvif is NULL
622 				 * when it is called from the originating path.
623 				 * However, it may not always be the case.
624 				 */
625 				m->m_pkthdr.rcvif = NULL;
626 				if (ip6_mforward(ip6, ifp, m) != 0) {
627 					m_freem(m);
628 					goto done;
629 				}
630 			}
631 		}
632 		/*
633 		 * Multicasts with a hoplimit of zero may be looped back,
634 		 * above, but must not be transmitted on a network.
635 		 * Also, multicasts addressed to the loopback interface
636 		 * are not sent -- the above call to ip6_mloopback() will
637 		 * loop back a copy if this host actually belongs to the
638 		 * destination group on the loopback interface.
639 		 */
640 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
641 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
642 			m_freem(m);
643 			goto done;
644 		}
645 	}
646 
647 	/*
648 	 * Fill the outgoing inteface to tell the upper layer
649 	 * to increment per-interface statistics.
650 	 */
651 	if (ifpp)
652 		*ifpp = ifp;
653 
654 	/* Determine path MTU. */
655 	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
656 	    &alwaysfrag, fibnum)) != 0)
657 		goto bad;
658 
659 	/*
660 	 * The caller of this function may specify to use the minimum MTU
661 	 * in some cases.
662 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
663 	 * setting.  The logic is a bit complicated; by default, unicast
664 	 * packets will follow path MTU while multicast packets will be sent at
665 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
666 	 * including unicast ones will be sent at the minimum MTU.  Multicast
667 	 * packets will always be sent at the minimum MTU unless
668 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
669 	 * See RFC 3542 for more details.
670 	 */
671 	if (mtu > IPV6_MMTU) {
672 		if ((flags & IPV6_MINMTU))
673 			mtu = IPV6_MMTU;
674 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
675 			mtu = IPV6_MMTU;
676 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
677 			 (opt == NULL ||
678 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
679 			mtu = IPV6_MMTU;
680 		}
681 	}
682 
683 	/*
684 	 * clear embedded scope identifiers if necessary.
685 	 * in6_clearscope will touch the addresses only when necessary.
686 	 */
687 	in6_clearscope(&ip6->ip6_src);
688 	in6_clearscope(&ip6->ip6_dst);
689 
690 	/*
691 	 * If the outgoing packet contains a hop-by-hop options header,
692 	 * it must be examined and processed even by the source node.
693 	 * (RFC 2460, section 4.)
694 	 */
695 	if (exthdrs.ip6e_hbh) {
696 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
697 		u_int32_t dummy; /* XXX unused */
698 		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
699 
700 #ifdef DIAGNOSTIC
701 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
702 			panic("ip6e_hbh is not contiguous");
703 #endif
704 		/*
705 		 *  XXX: if we have to send an ICMPv6 error to the sender,
706 		 *       we need the M_LOOP flag since icmp6_error() expects
707 		 *       the IPv6 and the hop-by-hop options header are
708 		 *       contiguous unless the flag is set.
709 		 */
710 		m->m_flags |= M_LOOP;
711 		m->m_pkthdr.rcvif = ifp;
712 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
713 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
714 		    &dummy, &plen) < 0) {
715 			/* m was already freed at this point */
716 			error = EINVAL;/* better error? */
717 			goto done;
718 		}
719 		m->m_flags &= ~M_LOOP; /* XXX */
720 		m->m_pkthdr.rcvif = NULL;
721 	}
722 
723 	/* Jump over all PFIL processing if hooks are not active. */
724 	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
725 		goto passout;
726 
727 	odst = ip6->ip6_dst;
728 	/* Run through list of hooks for output packets. */
729 	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
730 	if (error != 0 || m == NULL)
731 		goto done;
732 	ip6 = mtod(m, struct ip6_hdr *);
733 
734 	needfiblookup = 0;
735 	/* See if destination IP address was changed by packet filter. */
736 	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
737 		m->m_flags |= M_SKIP_FIREWALL;
738 		/* If destination is now ourself drop to ip6_input(). */
739 		if (in6_localip(&ip6->ip6_dst)) {
740 			m->m_flags |= M_FASTFWD_OURS;
741 			if (m->m_pkthdr.rcvif == NULL)
742 				m->m_pkthdr.rcvif = V_loif;
743 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
744 				m->m_pkthdr.csum_flags |=
745 				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
746 				m->m_pkthdr.csum_data = 0xffff;
747 			}
748 #ifdef SCTP
749 			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
750 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
751 #endif
752 			error = netisr_queue(NETISR_IPV6, m);
753 			goto done;
754 		} else
755 			needfiblookup = 1; /* Redo the routing table lookup. */
756 	}
757 	/* See if fib was changed by packet filter. */
758 	if (fibnum != M_GETFIB(m)) {
759 		m->m_flags |= M_SKIP_FIREWALL;
760 		fibnum = M_GETFIB(m);
761 		RO_RTFREE(ro);
762 		needfiblookup = 1;
763 	}
764 	if (needfiblookup)
765 		goto again;
766 
767 	/* See if local, if yes, send it to netisr. */
768 	if (m->m_flags & M_FASTFWD_OURS) {
769 		if (m->m_pkthdr.rcvif == NULL)
770 			m->m_pkthdr.rcvif = V_loif;
771 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
772 			m->m_pkthdr.csum_flags |=
773 			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
774 			m->m_pkthdr.csum_data = 0xffff;
775 		}
776 #ifdef SCTP
777 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
778 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
779 #endif
780 		error = netisr_queue(NETISR_IPV6, m);
781 		goto done;
782 	}
783 	/* Or forward to some other address? */
784 	if ((m->m_flags & M_IP6_NEXTHOP) &&
785 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
786 		dst = (struct sockaddr_in6 *)&ro->ro_dst;
787 		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
788 		m->m_flags |= M_SKIP_FIREWALL;
789 		m->m_flags &= ~M_IP6_NEXTHOP;
790 		m_tag_delete(m, fwd_tag);
791 		goto again;
792 	}
793 
794 passout:
795 	/*
796 	 * Send the packet to the outgoing interface.
797 	 * If necessary, do IPv6 fragmentation before sending.
798 	 *
799 	 * the logic here is rather complex:
800 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
801 	 * 1-a:	send as is if tlen <= path mtu
802 	 * 1-b:	fragment if tlen > path mtu
803 	 *
804 	 * 2: if user asks us not to fragment (dontfrag == 1)
805 	 * 2-a:	send as is if tlen <= interface mtu
806 	 * 2-b:	error if tlen > interface mtu
807 	 *
808 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
809 	 *	always fragment
810 	 *
811 	 * 4: if dontfrag == 1 && alwaysfrag == 1
812 	 *	error, as we cannot handle this conflicting request
813 	 */
814 	sw_csum = m->m_pkthdr.csum_flags;
815 	if (!hdrsplit) {
816 		tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
817 		sw_csum &= ~ifp->if_hwassist;
818 	} else
819 		tso = 0;
820 	/*
821 	 * If we added extension headers, we will not do TSO and calculate the
822 	 * checksums ourselves for now.
823 	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
824 	 * with ext. hdrs.
825 	 */
826 	if (sw_csum & CSUM_DELAY_DATA_IPV6) {
827 		sw_csum &= ~CSUM_DELAY_DATA_IPV6;
828 		in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
829 	}
830 #ifdef SCTP
831 	if (sw_csum & CSUM_SCTP_IPV6) {
832 		sw_csum &= ~CSUM_SCTP_IPV6;
833 		sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
834 	}
835 #endif
836 	m->m_pkthdr.csum_flags &= ifp->if_hwassist;
837 	tlen = m->m_pkthdr.len;
838 
839 	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
840 		dontfrag = 1;
841 	else
842 		dontfrag = 0;
843 	if (dontfrag && alwaysfrag) {	/* case 4 */
844 		/* conflicting request - can't transmit */
845 		error = EMSGSIZE;
846 		goto bad;
847 	}
848 	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* case 2-b */
849 		/*
850 		 * Even if the DONTFRAG option is specified, we cannot send the
851 		 * packet when the data length is larger than the MTU of the
852 		 * outgoing interface.
853 		 * Notify the error by sending IPV6_PATHMTU ancillary data as
854 		 * well as returning an error code (the latter is not described
855 		 * in the API spec.)
856 		 */
857 		u_int32_t mtu32;
858 		struct ip6ctlparam ip6cp;
859 
860 		mtu32 = (u_int32_t)mtu;
861 		bzero(&ip6cp, sizeof(ip6cp));
862 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
863 		pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
864 		    (void *)&ip6cp);
865 
866 		error = EMSGSIZE;
867 		goto bad;
868 	}
869 
870 	/*
871 	 * transmit packet without fragmentation
872 	 */
873 	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* case 1-a and 2-a */
874 		struct in6_ifaddr *ia6;
875 
876 		ip6 = mtod(m, struct ip6_hdr *);
877 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
878 		if (ia6) {
879 			/* Record statistics for this interface address. */
880 			counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
881 			counter_u64_add(ia6->ia_ifa.ifa_obytes,
882 			    m->m_pkthdr.len);
883 			ifa_free(&ia6->ia_ifa);
884 		}
885 		error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
886 		goto done;
887 	}
888 
889 	/*
890 	 * try to fragment the packet.  case 1-b and 3
891 	 */
892 	if (mtu < IPV6_MMTU) {
893 		/* path MTU cannot be less than IPV6_MMTU */
894 		error = EMSGSIZE;
895 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
896 		goto bad;
897 	} else if (ip6->ip6_plen == 0) {
898 		/* jumbo payload cannot be fragmented */
899 		error = EMSGSIZE;
900 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
901 		goto bad;
902 	} else {
903 		struct mbuf **mnext, *m_frgpart;
904 		struct ip6_frag *ip6f;
905 		u_int32_t id = htonl(ip6_randomid());
906 		u_char nextproto;
907 
908 		int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
909 
910 		/*
911 		 * Too large for the destination or interface;
912 		 * fragment if possible.
913 		 * Must be able to put at least 8 bytes per fragment.
914 		 */
915 		hlen = unfragpartlen;
916 		if (mtu > IPV6_MAXPACKET)
917 			mtu = IPV6_MAXPACKET;
918 
919 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
920 		if (len < 8) {
921 			error = EMSGSIZE;
922 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
923 			goto bad;
924 		}
925 
926 		/*
927 		 * Verify that we have any chance at all of being able to queue
928 		 *      the packet or packet fragments
929 		 */
930 		if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
931 		    < tlen  /* - hlen */)) {
932 			error = ENOBUFS;
933 			IP6STAT_INC(ip6s_odropped);
934 			goto bad;
935 		}
936 
937 
938 		/*
939 		 * If the interface will not calculate checksums on
940 		 * fragmented packets, then do it here.
941 		 * XXX-BZ handle the hw offloading case.  Need flags.
942 		 */
943 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
944 			in6_delayed_cksum(m, plen, hlen);
945 			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
946 		}
947 #ifdef SCTP
948 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
949 			sctp_delayed_cksum(m, hlen);
950 			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
951 		}
952 #endif
953 		mnext = &m->m_nextpkt;
954 
955 		/*
956 		 * Change the next header field of the last header in the
957 		 * unfragmentable part.
958 		 */
959 		if (exthdrs.ip6e_rthdr) {
960 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
961 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
962 		} else if (exthdrs.ip6e_dest1) {
963 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
964 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
965 		} else if (exthdrs.ip6e_hbh) {
966 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
967 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
968 		} else {
969 			nextproto = ip6->ip6_nxt;
970 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
971 		}
972 
973 		/*
974 		 * Loop through length of segment after first fragment,
975 		 * make new header and copy data of each part and link onto
976 		 * chain.
977 		 */
978 		m0 = m;
979 		for (off = hlen; off < tlen; off += len) {
980 			m = m_gethdr(M_NOWAIT, MT_DATA);
981 			if (!m) {
982 				error = ENOBUFS;
983 				IP6STAT_INC(ip6s_odropped);
984 				goto sendorfree;
985 			}
986 			m->m_flags = m0->m_flags & M_COPYFLAGS;
987 			*mnext = m;
988 			mnext = &m->m_nextpkt;
989 			m->m_data += max_linkhdr;
990 			mhip6 = mtod(m, struct ip6_hdr *);
991 			*mhip6 = *ip6;
992 			m->m_len = sizeof(*mhip6);
993 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
994 			if (error) {
995 				IP6STAT_INC(ip6s_odropped);
996 				goto sendorfree;
997 			}
998 			ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
999 			if (off + len >= tlen)
1000 				len = tlen - off;
1001 			else
1002 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1003 			mhip6->ip6_plen = htons((u_short)(len + hlen +
1004 			    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1005 			if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1006 				error = ENOBUFS;
1007 				IP6STAT_INC(ip6s_odropped);
1008 				goto sendorfree;
1009 			}
1010 			m_cat(m, m_frgpart);
1011 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1012 			m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
1013 			m->m_pkthdr.rcvif = NULL;
1014 			ip6f->ip6f_reserved = 0;
1015 			ip6f->ip6f_ident = id;
1016 			ip6f->ip6f_nxt = nextproto;
1017 			IP6STAT_INC(ip6s_ofragments);
1018 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1019 		}
1020 
1021 		in6_ifstat_inc(ifp, ifs6_out_fragok);
1022 	}
1023 
1024 	/*
1025 	 * Remove leading garbages.
1026 	 */
1027 sendorfree:
1028 	m = m0->m_nextpkt;
1029 	m0->m_nextpkt = 0;
1030 	m_freem(m0);
1031 	for (m0 = m; m; m = m0) {
1032 		m0 = m->m_nextpkt;
1033 		m->m_nextpkt = 0;
1034 		if (error == 0) {
1035 			/* Record statistics for this interface address. */
1036 			if (ia) {
1037 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1038 				counter_u64_add(ia->ia_ifa.ifa_obytes,
1039 				    m->m_pkthdr.len);
1040 			}
1041 			error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1042 		} else
1043 			m_freem(m);
1044 	}
1045 
1046 	if (error == 0)
1047 		IP6STAT_INC(ip6s_fragmented);
1048 
1049 done:
1050 	if (ro == &ip6route)
1051 		RO_RTFREE(ro);
1052 	if (ro_pmtu == &ip6route)
1053 		RO_RTFREE(ro_pmtu);
1054 	return (error);
1055 
1056 freehdrs:
1057 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
1058 	m_freem(exthdrs.ip6e_dest1);
1059 	m_freem(exthdrs.ip6e_rthdr);
1060 	m_freem(exthdrs.ip6e_dest2);
1061 	/* FALLTHROUGH */
1062 bad:
1063 	if (m)
1064 		m_freem(m);
1065 	goto done;
1066 }
1067 
1068 static int
1069 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1070 {
1071 	struct mbuf *m;
1072 
1073 	if (hlen > MCLBYTES)
1074 		return (ENOBUFS); /* XXX */
1075 
1076 	if (hlen > MLEN)
1077 		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1078 	else
1079 		m = m_get(M_NOWAIT, MT_DATA);
1080 	if (m == NULL)
1081 		return (ENOBUFS);
1082 	m->m_len = hlen;
1083 	if (hdr)
1084 		bcopy(hdr, mtod(m, caddr_t), hlen);
1085 
1086 	*mp = m;
1087 	return (0);
1088 }
1089 
1090 /*
1091  * Insert jumbo payload option.
1092  */
1093 static int
1094 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1095 {
1096 	struct mbuf *mopt;
1097 	u_char *optbuf;
1098 	u_int32_t v;
1099 
1100 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1101 
1102 	/*
1103 	 * If there is no hop-by-hop options header, allocate new one.
1104 	 * If there is one but it doesn't have enough space to store the
1105 	 * jumbo payload option, allocate a cluster to store the whole options.
1106 	 * Otherwise, use it to store the options.
1107 	 */
1108 	if (exthdrs->ip6e_hbh == 0) {
1109 		mopt = m_get(M_NOWAIT, MT_DATA);
1110 		if (mopt == NULL)
1111 			return (ENOBUFS);
1112 		mopt->m_len = JUMBOOPTLEN;
1113 		optbuf = mtod(mopt, u_char *);
1114 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1115 		exthdrs->ip6e_hbh = mopt;
1116 	} else {
1117 		struct ip6_hbh *hbh;
1118 
1119 		mopt = exthdrs->ip6e_hbh;
1120 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1121 			/*
1122 			 * XXX assumption:
1123 			 * - exthdrs->ip6e_hbh is not referenced from places
1124 			 *   other than exthdrs.
1125 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1126 			 */
1127 			int oldoptlen = mopt->m_len;
1128 			struct mbuf *n;
1129 
1130 			/*
1131 			 * XXX: give up if the whole (new) hbh header does
1132 			 * not fit even in an mbuf cluster.
1133 			 */
1134 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1135 				return (ENOBUFS);
1136 
1137 			/*
1138 			 * As a consequence, we must always prepare a cluster
1139 			 * at this point.
1140 			 */
1141 			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1142 			if (n == NULL)
1143 				return (ENOBUFS);
1144 			n->m_len = oldoptlen + JUMBOOPTLEN;
1145 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1146 			    oldoptlen);
1147 			optbuf = mtod(n, caddr_t) + oldoptlen;
1148 			m_freem(mopt);
1149 			mopt = exthdrs->ip6e_hbh = n;
1150 		} else {
1151 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1152 			mopt->m_len += JUMBOOPTLEN;
1153 		}
1154 		optbuf[0] = IP6OPT_PADN;
1155 		optbuf[1] = 1;
1156 
1157 		/*
1158 		 * Adjust the header length according to the pad and
1159 		 * the jumbo payload option.
1160 		 */
1161 		hbh = mtod(mopt, struct ip6_hbh *);
1162 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1163 	}
1164 
1165 	/* fill in the option. */
1166 	optbuf[2] = IP6OPT_JUMBO;
1167 	optbuf[3] = 4;
1168 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1169 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1170 
1171 	/* finally, adjust the packet header length */
1172 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1173 
1174 	return (0);
1175 #undef JUMBOOPTLEN
1176 }
1177 
1178 /*
1179  * Insert fragment header and copy unfragmentable header portions.
1180  */
1181 static int
1182 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1183     struct ip6_frag **frghdrp)
1184 {
1185 	struct mbuf *n, *mlast;
1186 
1187 	if (hlen > sizeof(struct ip6_hdr)) {
1188 		n = m_copym(m0, sizeof(struct ip6_hdr),
1189 		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1190 		if (n == 0)
1191 			return (ENOBUFS);
1192 		m->m_next = n;
1193 	} else
1194 		n = m;
1195 
1196 	/* Search for the last mbuf of unfragmentable part. */
1197 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1198 		;
1199 
1200 	if (M_WRITABLE(mlast) &&
1201 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1202 		/* use the trailing space of the last mbuf for the fragment hdr */
1203 		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1204 		    mlast->m_len);
1205 		mlast->m_len += sizeof(struct ip6_frag);
1206 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1207 	} else {
1208 		/* allocate a new mbuf for the fragment header */
1209 		struct mbuf *mfrg;
1210 
1211 		mfrg = m_get(M_NOWAIT, MT_DATA);
1212 		if (mfrg == NULL)
1213 			return (ENOBUFS);
1214 		mfrg->m_len = sizeof(struct ip6_frag);
1215 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1216 		mlast->m_next = mfrg;
1217 	}
1218 
1219 	return (0);
1220 }
1221 
1222 static int
1223 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1224     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1225     int *alwaysfragp, u_int fibnum)
1226 {
1227 	u_int32_t mtu = 0;
1228 	int alwaysfrag = 0;
1229 	int error = 0;
1230 
1231 	if (ro_pmtu != ro) {
1232 		/* The first hop and the final destination may differ. */
1233 		struct sockaddr_in6 *sa6_dst =
1234 		    (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1235 		if (ro_pmtu->ro_rt &&
1236 		    ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1237 		     !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1238 			RTFREE(ro_pmtu->ro_rt);
1239 			ro_pmtu->ro_rt = (struct rtentry *)NULL;
1240 		}
1241 		if (ro_pmtu->ro_rt == NULL) {
1242 			bzero(sa6_dst, sizeof(*sa6_dst));
1243 			sa6_dst->sin6_family = AF_INET6;
1244 			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1245 			sa6_dst->sin6_addr = *dst;
1246 
1247 			in6_rtalloc(ro_pmtu, fibnum);
1248 		}
1249 	}
1250 	if (ro_pmtu->ro_rt) {
1251 		u_int32_t ifmtu;
1252 		struct in_conninfo inc;
1253 
1254 		bzero(&inc, sizeof(inc));
1255 		inc.inc_flags |= INC_ISIPV6;
1256 		inc.inc6_faddr = *dst;
1257 
1258 		if (ifp == NULL)
1259 			ifp = ro_pmtu->ro_rt->rt_ifp;
1260 		ifmtu = IN6_LINKMTU(ifp);
1261 		mtu = tcp_hc_getmtu(&inc);
1262 		if (mtu)
1263 			mtu = min(mtu, ro_pmtu->ro_rt->rt_mtu);
1264 		else
1265 			mtu = ro_pmtu->ro_rt->rt_mtu;
1266 		if (mtu == 0)
1267 			mtu = ifmtu;
1268 		else if (mtu < IPV6_MMTU) {
1269 			/*
1270 			 * RFC2460 section 5, last paragraph:
1271 			 * if we record ICMPv6 too big message with
1272 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1273 			 * or smaller, with framgent header attached.
1274 			 * (fragment header is needed regardless from the
1275 			 * packet size, for translators to identify packets)
1276 			 */
1277 			alwaysfrag = 1;
1278 			mtu = IPV6_MMTU;
1279 		}
1280 	} else if (ifp) {
1281 		mtu = IN6_LINKMTU(ifp);
1282 	} else
1283 		error = EHOSTUNREACH; /* XXX */
1284 
1285 	*mtup = mtu;
1286 	if (alwaysfragp)
1287 		*alwaysfragp = alwaysfrag;
1288 	return (error);
1289 }
1290 
1291 /*
1292  * IP6 socket option processing.
1293  */
1294 int
1295 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1296 {
1297 	int optdatalen, uproto;
1298 	void *optdata;
1299 	struct inpcb *in6p = sotoinpcb(so);
1300 	int error, optval;
1301 	int level, op, optname;
1302 	int optlen;
1303 	struct thread *td;
1304 #ifdef	RSS
1305 	uint32_t rss_bucket;
1306 	int retval;
1307 #endif
1308 
1309 	level = sopt->sopt_level;
1310 	op = sopt->sopt_dir;
1311 	optname = sopt->sopt_name;
1312 	optlen = sopt->sopt_valsize;
1313 	td = sopt->sopt_td;
1314 	error = 0;
1315 	optval = 0;
1316 	uproto = (int)so->so_proto->pr_protocol;
1317 
1318 	if (level != IPPROTO_IPV6) {
1319 		error = EINVAL;
1320 
1321 		if (sopt->sopt_level == SOL_SOCKET &&
1322 		    sopt->sopt_dir == SOPT_SET) {
1323 			switch (sopt->sopt_name) {
1324 			case SO_REUSEADDR:
1325 				INP_WLOCK(in6p);
1326 				if ((so->so_options & SO_REUSEADDR) != 0)
1327 					in6p->inp_flags2 |= INP_REUSEADDR;
1328 				else
1329 					in6p->inp_flags2 &= ~INP_REUSEADDR;
1330 				INP_WUNLOCK(in6p);
1331 				error = 0;
1332 				break;
1333 			case SO_REUSEPORT:
1334 				INP_WLOCK(in6p);
1335 				if ((so->so_options & SO_REUSEPORT) != 0)
1336 					in6p->inp_flags2 |= INP_REUSEPORT;
1337 				else
1338 					in6p->inp_flags2 &= ~INP_REUSEPORT;
1339 				INP_WUNLOCK(in6p);
1340 				error = 0;
1341 				break;
1342 			case SO_SETFIB:
1343 				INP_WLOCK(in6p);
1344 				in6p->inp_inc.inc_fibnum = so->so_fibnum;
1345 				INP_WUNLOCK(in6p);
1346 				error = 0;
1347 				break;
1348 			default:
1349 				break;
1350 			}
1351 		}
1352 	} else {		/* level == IPPROTO_IPV6 */
1353 		switch (op) {
1354 
1355 		case SOPT_SET:
1356 			switch (optname) {
1357 			case IPV6_2292PKTOPTIONS:
1358 #ifdef IPV6_PKTOPTIONS
1359 			case IPV6_PKTOPTIONS:
1360 #endif
1361 			{
1362 				struct mbuf *m;
1363 
1364 				error = soopt_getm(sopt, &m); /* XXX */
1365 				if (error != 0)
1366 					break;
1367 				error = soopt_mcopyin(sopt, m); /* XXX */
1368 				if (error != 0)
1369 					break;
1370 				error = ip6_pcbopts(&in6p->in6p_outputopts,
1371 						    m, so, sopt);
1372 				m_freem(m); /* XXX */
1373 				break;
1374 			}
1375 
1376 			/*
1377 			 * Use of some Hop-by-Hop options or some
1378 			 * Destination options, might require special
1379 			 * privilege.  That is, normal applications
1380 			 * (without special privilege) might be forbidden
1381 			 * from setting certain options in outgoing packets,
1382 			 * and might never see certain options in received
1383 			 * packets. [RFC 2292 Section 6]
1384 			 * KAME specific note:
1385 			 *  KAME prevents non-privileged users from sending or
1386 			 *  receiving ANY hbh/dst options in order to avoid
1387 			 *  overhead of parsing options in the kernel.
1388 			 */
1389 			case IPV6_RECVHOPOPTS:
1390 			case IPV6_RECVDSTOPTS:
1391 			case IPV6_RECVRTHDRDSTOPTS:
1392 				if (td != NULL) {
1393 					error = priv_check(td,
1394 					    PRIV_NETINET_SETHDROPTS);
1395 					if (error)
1396 						break;
1397 				}
1398 				/* FALLTHROUGH */
1399 			case IPV6_UNICAST_HOPS:
1400 			case IPV6_HOPLIMIT:
1401 
1402 			case IPV6_RECVPKTINFO:
1403 			case IPV6_RECVHOPLIMIT:
1404 			case IPV6_RECVRTHDR:
1405 			case IPV6_RECVPATHMTU:
1406 			case IPV6_RECVTCLASS:
1407 			case IPV6_V6ONLY:
1408 			case IPV6_AUTOFLOWLABEL:
1409 			case IPV6_BINDANY:
1410 			case IPV6_BINDMULTI:
1411 #ifdef	RSS
1412 			case IPV6_RSS_LISTEN_BUCKET:
1413 #endif
1414 				if (optname == IPV6_BINDANY && td != NULL) {
1415 					error = priv_check(td,
1416 					    PRIV_NETINET_BINDANY);
1417 					if (error)
1418 						break;
1419 				}
1420 
1421 				if (optlen != sizeof(int)) {
1422 					error = EINVAL;
1423 					break;
1424 				}
1425 				error = sooptcopyin(sopt, &optval,
1426 					sizeof optval, sizeof optval);
1427 				if (error)
1428 					break;
1429 				switch (optname) {
1430 
1431 				case IPV6_UNICAST_HOPS:
1432 					if (optval < -1 || optval >= 256)
1433 						error = EINVAL;
1434 					else {
1435 						/* -1 = kernel default */
1436 						in6p->in6p_hops = optval;
1437 						if ((in6p->inp_vflag &
1438 						     INP_IPV4) != 0)
1439 							in6p->inp_ip_ttl = optval;
1440 					}
1441 					break;
1442 #define OPTSET(bit) \
1443 do { \
1444 	INP_WLOCK(in6p); \
1445 	if (optval) \
1446 		in6p->inp_flags |= (bit); \
1447 	else \
1448 		in6p->inp_flags &= ~(bit); \
1449 	INP_WUNLOCK(in6p); \
1450 } while (/*CONSTCOND*/ 0)
1451 #define OPTSET2292(bit) \
1452 do { \
1453 	INP_WLOCK(in6p); \
1454 	in6p->inp_flags |= IN6P_RFC2292; \
1455 	if (optval) \
1456 		in6p->inp_flags |= (bit); \
1457 	else \
1458 		in6p->inp_flags &= ~(bit); \
1459 	INP_WUNLOCK(in6p); \
1460 } while (/*CONSTCOND*/ 0)
1461 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1462 
1463 #define OPTSET2(bit, val) do {						\
1464 	INP_WLOCK(in6p);						\
1465 	if (val)							\
1466 		in6p->inp_flags2 |= bit;				\
1467 	else								\
1468 		in6p->inp_flags2 &= ~bit;				\
1469 	INP_WUNLOCK(in6p);						\
1470 } while (0)
1471 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1472 
1473 				case IPV6_RECVPKTINFO:
1474 					/* cannot mix with RFC2292 */
1475 					if (OPTBIT(IN6P_RFC2292)) {
1476 						error = EINVAL;
1477 						break;
1478 					}
1479 					OPTSET(IN6P_PKTINFO);
1480 					break;
1481 
1482 				case IPV6_HOPLIMIT:
1483 				{
1484 					struct ip6_pktopts **optp;
1485 
1486 					/* cannot mix with RFC2292 */
1487 					if (OPTBIT(IN6P_RFC2292)) {
1488 						error = EINVAL;
1489 						break;
1490 					}
1491 					optp = &in6p->in6p_outputopts;
1492 					error = ip6_pcbopt(IPV6_HOPLIMIT,
1493 					    (u_char *)&optval, sizeof(optval),
1494 					    optp, (td != NULL) ? td->td_ucred :
1495 					    NULL, uproto);
1496 					break;
1497 				}
1498 
1499 				case IPV6_RECVHOPLIMIT:
1500 					/* cannot mix with RFC2292 */
1501 					if (OPTBIT(IN6P_RFC2292)) {
1502 						error = EINVAL;
1503 						break;
1504 					}
1505 					OPTSET(IN6P_HOPLIMIT);
1506 					break;
1507 
1508 				case IPV6_RECVHOPOPTS:
1509 					/* cannot mix with RFC2292 */
1510 					if (OPTBIT(IN6P_RFC2292)) {
1511 						error = EINVAL;
1512 						break;
1513 					}
1514 					OPTSET(IN6P_HOPOPTS);
1515 					break;
1516 
1517 				case IPV6_RECVDSTOPTS:
1518 					/* cannot mix with RFC2292 */
1519 					if (OPTBIT(IN6P_RFC2292)) {
1520 						error = EINVAL;
1521 						break;
1522 					}
1523 					OPTSET(IN6P_DSTOPTS);
1524 					break;
1525 
1526 				case IPV6_RECVRTHDRDSTOPTS:
1527 					/* cannot mix with RFC2292 */
1528 					if (OPTBIT(IN6P_RFC2292)) {
1529 						error = EINVAL;
1530 						break;
1531 					}
1532 					OPTSET(IN6P_RTHDRDSTOPTS);
1533 					break;
1534 
1535 				case IPV6_RECVRTHDR:
1536 					/* cannot mix with RFC2292 */
1537 					if (OPTBIT(IN6P_RFC2292)) {
1538 						error = EINVAL;
1539 						break;
1540 					}
1541 					OPTSET(IN6P_RTHDR);
1542 					break;
1543 
1544 				case IPV6_RECVPATHMTU:
1545 					/*
1546 					 * We ignore this option for TCP
1547 					 * sockets.
1548 					 * (RFC3542 leaves this case
1549 					 * unspecified.)
1550 					 */
1551 					if (uproto != IPPROTO_TCP)
1552 						OPTSET(IN6P_MTU);
1553 					break;
1554 
1555 				case IPV6_V6ONLY:
1556 					/*
1557 					 * make setsockopt(IPV6_V6ONLY)
1558 					 * available only prior to bind(2).
1559 					 * see ipng mailing list, Jun 22 2001.
1560 					 */
1561 					if (in6p->inp_lport ||
1562 					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1563 						error = EINVAL;
1564 						break;
1565 					}
1566 					OPTSET(IN6P_IPV6_V6ONLY);
1567 					if (optval)
1568 						in6p->inp_vflag &= ~INP_IPV4;
1569 					else
1570 						in6p->inp_vflag |= INP_IPV4;
1571 					break;
1572 				case IPV6_RECVTCLASS:
1573 					/* cannot mix with RFC2292 XXX */
1574 					if (OPTBIT(IN6P_RFC2292)) {
1575 						error = EINVAL;
1576 						break;
1577 					}
1578 					OPTSET(IN6P_TCLASS);
1579 					break;
1580 				case IPV6_AUTOFLOWLABEL:
1581 					OPTSET(IN6P_AUTOFLOWLABEL);
1582 					break;
1583 
1584 				case IPV6_BINDANY:
1585 					OPTSET(INP_BINDANY);
1586 					break;
1587 
1588 				case IPV6_BINDMULTI:
1589 					OPTSET2(INP_BINDMULTI, optval);
1590 					break;
1591 #ifdef	RSS
1592 				case IPV6_RSS_LISTEN_BUCKET:
1593 					if ((optval >= 0) &&
1594 					    (optval < rss_getnumbuckets())) {
1595 						in6p->inp_rss_listen_bucket = optval;
1596 						OPTSET2(INP_RSS_BUCKET_SET, 1);
1597 					} else {
1598 						error = EINVAL;
1599 					}
1600 					break;
1601 #endif
1602 				}
1603 				break;
1604 
1605 			case IPV6_TCLASS:
1606 			case IPV6_DONTFRAG:
1607 			case IPV6_USE_MIN_MTU:
1608 			case IPV6_PREFER_TEMPADDR:
1609 				if (optlen != sizeof(optval)) {
1610 					error = EINVAL;
1611 					break;
1612 				}
1613 				error = sooptcopyin(sopt, &optval,
1614 					sizeof optval, sizeof optval);
1615 				if (error)
1616 					break;
1617 				{
1618 					struct ip6_pktopts **optp;
1619 					optp = &in6p->in6p_outputopts;
1620 					error = ip6_pcbopt(optname,
1621 					    (u_char *)&optval, sizeof(optval),
1622 					    optp, (td != NULL) ? td->td_ucred :
1623 					    NULL, uproto);
1624 					break;
1625 				}
1626 
1627 			case IPV6_2292PKTINFO:
1628 			case IPV6_2292HOPLIMIT:
1629 			case IPV6_2292HOPOPTS:
1630 			case IPV6_2292DSTOPTS:
1631 			case IPV6_2292RTHDR:
1632 				/* RFC 2292 */
1633 				if (optlen != sizeof(int)) {
1634 					error = EINVAL;
1635 					break;
1636 				}
1637 				error = sooptcopyin(sopt, &optval,
1638 					sizeof optval, sizeof optval);
1639 				if (error)
1640 					break;
1641 				switch (optname) {
1642 				case IPV6_2292PKTINFO:
1643 					OPTSET2292(IN6P_PKTINFO);
1644 					break;
1645 				case IPV6_2292HOPLIMIT:
1646 					OPTSET2292(IN6P_HOPLIMIT);
1647 					break;
1648 				case IPV6_2292HOPOPTS:
1649 					/*
1650 					 * Check super-user privilege.
1651 					 * See comments for IPV6_RECVHOPOPTS.
1652 					 */
1653 					if (td != NULL) {
1654 						error = priv_check(td,
1655 						    PRIV_NETINET_SETHDROPTS);
1656 						if (error)
1657 							return (error);
1658 					}
1659 					OPTSET2292(IN6P_HOPOPTS);
1660 					break;
1661 				case IPV6_2292DSTOPTS:
1662 					if (td != NULL) {
1663 						error = priv_check(td,
1664 						    PRIV_NETINET_SETHDROPTS);
1665 						if (error)
1666 							return (error);
1667 					}
1668 					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1669 					break;
1670 				case IPV6_2292RTHDR:
1671 					OPTSET2292(IN6P_RTHDR);
1672 					break;
1673 				}
1674 				break;
1675 			case IPV6_PKTINFO:
1676 			case IPV6_HOPOPTS:
1677 			case IPV6_RTHDR:
1678 			case IPV6_DSTOPTS:
1679 			case IPV6_RTHDRDSTOPTS:
1680 			case IPV6_NEXTHOP:
1681 			{
1682 				/* new advanced API (RFC3542) */
1683 				u_char *optbuf;
1684 				u_char optbuf_storage[MCLBYTES];
1685 				int optlen;
1686 				struct ip6_pktopts **optp;
1687 
1688 				/* cannot mix with RFC2292 */
1689 				if (OPTBIT(IN6P_RFC2292)) {
1690 					error = EINVAL;
1691 					break;
1692 				}
1693 
1694 				/*
1695 				 * We only ensure valsize is not too large
1696 				 * here.  Further validation will be done
1697 				 * later.
1698 				 */
1699 				error = sooptcopyin(sopt, optbuf_storage,
1700 				    sizeof(optbuf_storage), 0);
1701 				if (error)
1702 					break;
1703 				optlen = sopt->sopt_valsize;
1704 				optbuf = optbuf_storage;
1705 				optp = &in6p->in6p_outputopts;
1706 				error = ip6_pcbopt(optname, optbuf, optlen,
1707 				    optp, (td != NULL) ? td->td_ucred : NULL,
1708 				    uproto);
1709 				break;
1710 			}
1711 #undef OPTSET
1712 
1713 			case IPV6_MULTICAST_IF:
1714 			case IPV6_MULTICAST_HOPS:
1715 			case IPV6_MULTICAST_LOOP:
1716 			case IPV6_JOIN_GROUP:
1717 			case IPV6_LEAVE_GROUP:
1718 			case IPV6_MSFILTER:
1719 			case MCAST_BLOCK_SOURCE:
1720 			case MCAST_UNBLOCK_SOURCE:
1721 			case MCAST_JOIN_GROUP:
1722 			case MCAST_LEAVE_GROUP:
1723 			case MCAST_JOIN_SOURCE_GROUP:
1724 			case MCAST_LEAVE_SOURCE_GROUP:
1725 				error = ip6_setmoptions(in6p, sopt);
1726 				break;
1727 
1728 			case IPV6_PORTRANGE:
1729 				error = sooptcopyin(sopt, &optval,
1730 				    sizeof optval, sizeof optval);
1731 				if (error)
1732 					break;
1733 
1734 				INP_WLOCK(in6p);
1735 				switch (optval) {
1736 				case IPV6_PORTRANGE_DEFAULT:
1737 					in6p->inp_flags &= ~(INP_LOWPORT);
1738 					in6p->inp_flags &= ~(INP_HIGHPORT);
1739 					break;
1740 
1741 				case IPV6_PORTRANGE_HIGH:
1742 					in6p->inp_flags &= ~(INP_LOWPORT);
1743 					in6p->inp_flags |= INP_HIGHPORT;
1744 					break;
1745 
1746 				case IPV6_PORTRANGE_LOW:
1747 					in6p->inp_flags &= ~(INP_HIGHPORT);
1748 					in6p->inp_flags |= INP_LOWPORT;
1749 					break;
1750 
1751 				default:
1752 					error = EINVAL;
1753 					break;
1754 				}
1755 				INP_WUNLOCK(in6p);
1756 				break;
1757 
1758 #ifdef IPSEC
1759 			case IPV6_IPSEC_POLICY:
1760 			{
1761 				caddr_t req;
1762 				struct mbuf *m;
1763 
1764 				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1765 					break;
1766 				if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1767 					break;
1768 				req = mtod(m, caddr_t);
1769 				error = ipsec_set_policy(in6p, optname, req,
1770 				    m->m_len, (sopt->sopt_td != NULL) ?
1771 				    sopt->sopt_td->td_ucred : NULL);
1772 				m_freem(m);
1773 				break;
1774 			}
1775 #endif /* IPSEC */
1776 
1777 			default:
1778 				error = ENOPROTOOPT;
1779 				break;
1780 			}
1781 			break;
1782 
1783 		case SOPT_GET:
1784 			switch (optname) {
1785 
1786 			case IPV6_2292PKTOPTIONS:
1787 #ifdef IPV6_PKTOPTIONS
1788 			case IPV6_PKTOPTIONS:
1789 #endif
1790 				/*
1791 				 * RFC3542 (effectively) deprecated the
1792 				 * semantics of the 2292-style pktoptions.
1793 				 * Since it was not reliable in nature (i.e.,
1794 				 * applications had to expect the lack of some
1795 				 * information after all), it would make sense
1796 				 * to simplify this part by always returning
1797 				 * empty data.
1798 				 */
1799 				sopt->sopt_valsize = 0;
1800 				break;
1801 
1802 			case IPV6_RECVHOPOPTS:
1803 			case IPV6_RECVDSTOPTS:
1804 			case IPV6_RECVRTHDRDSTOPTS:
1805 			case IPV6_UNICAST_HOPS:
1806 			case IPV6_RECVPKTINFO:
1807 			case IPV6_RECVHOPLIMIT:
1808 			case IPV6_RECVRTHDR:
1809 			case IPV6_RECVPATHMTU:
1810 
1811 			case IPV6_V6ONLY:
1812 			case IPV6_PORTRANGE:
1813 			case IPV6_RECVTCLASS:
1814 			case IPV6_AUTOFLOWLABEL:
1815 			case IPV6_BINDANY:
1816 			case IPV6_FLOWID:
1817 			case IPV6_FLOWTYPE:
1818 #ifdef	RSS
1819 			case IPV6_RSSBUCKETID:
1820 #endif
1821 				switch (optname) {
1822 
1823 				case IPV6_RECVHOPOPTS:
1824 					optval = OPTBIT(IN6P_HOPOPTS);
1825 					break;
1826 
1827 				case IPV6_RECVDSTOPTS:
1828 					optval = OPTBIT(IN6P_DSTOPTS);
1829 					break;
1830 
1831 				case IPV6_RECVRTHDRDSTOPTS:
1832 					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1833 					break;
1834 
1835 				case IPV6_UNICAST_HOPS:
1836 					optval = in6p->in6p_hops;
1837 					break;
1838 
1839 				case IPV6_RECVPKTINFO:
1840 					optval = OPTBIT(IN6P_PKTINFO);
1841 					break;
1842 
1843 				case IPV6_RECVHOPLIMIT:
1844 					optval = OPTBIT(IN6P_HOPLIMIT);
1845 					break;
1846 
1847 				case IPV6_RECVRTHDR:
1848 					optval = OPTBIT(IN6P_RTHDR);
1849 					break;
1850 
1851 				case IPV6_RECVPATHMTU:
1852 					optval = OPTBIT(IN6P_MTU);
1853 					break;
1854 
1855 				case IPV6_V6ONLY:
1856 					optval = OPTBIT(IN6P_IPV6_V6ONLY);
1857 					break;
1858 
1859 				case IPV6_PORTRANGE:
1860 				    {
1861 					int flags;
1862 					flags = in6p->inp_flags;
1863 					if (flags & INP_HIGHPORT)
1864 						optval = IPV6_PORTRANGE_HIGH;
1865 					else if (flags & INP_LOWPORT)
1866 						optval = IPV6_PORTRANGE_LOW;
1867 					else
1868 						optval = 0;
1869 					break;
1870 				    }
1871 				case IPV6_RECVTCLASS:
1872 					optval = OPTBIT(IN6P_TCLASS);
1873 					break;
1874 
1875 				case IPV6_AUTOFLOWLABEL:
1876 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1877 					break;
1878 
1879 				case IPV6_BINDANY:
1880 					optval = OPTBIT(INP_BINDANY);
1881 					break;
1882 
1883 				case IPV6_FLOWID:
1884 					optval = in6p->inp_flowid;
1885 					break;
1886 
1887 				case IPV6_FLOWTYPE:
1888 					optval = in6p->inp_flowtype;
1889 					break;
1890 #ifdef	RSS
1891 				case IPV6_RSSBUCKETID:
1892 					retval =
1893 					    rss_hash2bucket(in6p->inp_flowid,
1894 					    in6p->inp_flowtype,
1895 					    &rss_bucket);
1896 					if (retval == 0)
1897 						optval = rss_bucket;
1898 					else
1899 						error = EINVAL;
1900 					break;
1901 #endif
1902 
1903 				case IPV6_BINDMULTI:
1904 					optval = OPTBIT2(INP_BINDMULTI);
1905 					break;
1906 
1907 				}
1908 				if (error)
1909 					break;
1910 				error = sooptcopyout(sopt, &optval,
1911 					sizeof optval);
1912 				break;
1913 
1914 			case IPV6_PATHMTU:
1915 			{
1916 				u_long pmtu = 0;
1917 				struct ip6_mtuinfo mtuinfo;
1918 				struct route_in6 sro;
1919 
1920 				bzero(&sro, sizeof(sro));
1921 
1922 				if (!(so->so_state & SS_ISCONNECTED))
1923 					return (ENOTCONN);
1924 				/*
1925 				 * XXX: we dot not consider the case of source
1926 				 * routing, or optional information to specify
1927 				 * the outgoing interface.
1928 				 */
1929 				error = ip6_getpmtu(&sro, NULL, NULL,
1930 				    &in6p->in6p_faddr, &pmtu, NULL,
1931 				    so->so_fibnum);
1932 				if (sro.ro_rt)
1933 					RTFREE(sro.ro_rt);
1934 				if (error)
1935 					break;
1936 				if (pmtu > IPV6_MAXPACKET)
1937 					pmtu = IPV6_MAXPACKET;
1938 
1939 				bzero(&mtuinfo, sizeof(mtuinfo));
1940 				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1941 				optdata = (void *)&mtuinfo;
1942 				optdatalen = sizeof(mtuinfo);
1943 				error = sooptcopyout(sopt, optdata,
1944 				    optdatalen);
1945 				break;
1946 			}
1947 
1948 			case IPV6_2292PKTINFO:
1949 			case IPV6_2292HOPLIMIT:
1950 			case IPV6_2292HOPOPTS:
1951 			case IPV6_2292RTHDR:
1952 			case IPV6_2292DSTOPTS:
1953 				switch (optname) {
1954 				case IPV6_2292PKTINFO:
1955 					optval = OPTBIT(IN6P_PKTINFO);
1956 					break;
1957 				case IPV6_2292HOPLIMIT:
1958 					optval = OPTBIT(IN6P_HOPLIMIT);
1959 					break;
1960 				case IPV6_2292HOPOPTS:
1961 					optval = OPTBIT(IN6P_HOPOPTS);
1962 					break;
1963 				case IPV6_2292RTHDR:
1964 					optval = OPTBIT(IN6P_RTHDR);
1965 					break;
1966 				case IPV6_2292DSTOPTS:
1967 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1968 					break;
1969 				}
1970 				error = sooptcopyout(sopt, &optval,
1971 				    sizeof optval);
1972 				break;
1973 			case IPV6_PKTINFO:
1974 			case IPV6_HOPOPTS:
1975 			case IPV6_RTHDR:
1976 			case IPV6_DSTOPTS:
1977 			case IPV6_RTHDRDSTOPTS:
1978 			case IPV6_NEXTHOP:
1979 			case IPV6_TCLASS:
1980 			case IPV6_DONTFRAG:
1981 			case IPV6_USE_MIN_MTU:
1982 			case IPV6_PREFER_TEMPADDR:
1983 				error = ip6_getpcbopt(in6p->in6p_outputopts,
1984 				    optname, sopt);
1985 				break;
1986 
1987 			case IPV6_MULTICAST_IF:
1988 			case IPV6_MULTICAST_HOPS:
1989 			case IPV6_MULTICAST_LOOP:
1990 			case IPV6_MSFILTER:
1991 				error = ip6_getmoptions(in6p, sopt);
1992 				break;
1993 
1994 #ifdef IPSEC
1995 			case IPV6_IPSEC_POLICY:
1996 			  {
1997 				caddr_t req = NULL;
1998 				size_t len = 0;
1999 				struct mbuf *m = NULL;
2000 				struct mbuf **mp = &m;
2001 				size_t ovalsize = sopt->sopt_valsize;
2002 				caddr_t oval = (caddr_t)sopt->sopt_val;
2003 
2004 				error = soopt_getm(sopt, &m); /* XXX */
2005 				if (error != 0)
2006 					break;
2007 				error = soopt_mcopyin(sopt, m); /* XXX */
2008 				if (error != 0)
2009 					break;
2010 				sopt->sopt_valsize = ovalsize;
2011 				sopt->sopt_val = oval;
2012 				if (m) {
2013 					req = mtod(m, caddr_t);
2014 					len = m->m_len;
2015 				}
2016 				error = ipsec_get_policy(in6p, req, len, mp);
2017 				if (error == 0)
2018 					error = soopt_mcopyout(sopt, m); /* XXX */
2019 				if (error == 0 && m)
2020 					m_freem(m);
2021 				break;
2022 			  }
2023 #endif /* IPSEC */
2024 
2025 			default:
2026 				error = ENOPROTOOPT;
2027 				break;
2028 			}
2029 			break;
2030 		}
2031 	}
2032 	return (error);
2033 }
2034 
2035 int
2036 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2037 {
2038 	int error = 0, optval, optlen;
2039 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2040 	struct inpcb *in6p = sotoinpcb(so);
2041 	int level, op, optname;
2042 
2043 	level = sopt->sopt_level;
2044 	op = sopt->sopt_dir;
2045 	optname = sopt->sopt_name;
2046 	optlen = sopt->sopt_valsize;
2047 
2048 	if (level != IPPROTO_IPV6) {
2049 		return (EINVAL);
2050 	}
2051 
2052 	switch (optname) {
2053 	case IPV6_CHECKSUM:
2054 		/*
2055 		 * For ICMPv6 sockets, no modification allowed for checksum
2056 		 * offset, permit "no change" values to help existing apps.
2057 		 *
2058 		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2059 		 * for an ICMPv6 socket will fail."
2060 		 * The current behavior does not meet RFC3542.
2061 		 */
2062 		switch (op) {
2063 		case SOPT_SET:
2064 			if (optlen != sizeof(int)) {
2065 				error = EINVAL;
2066 				break;
2067 			}
2068 			error = sooptcopyin(sopt, &optval, sizeof(optval),
2069 					    sizeof(optval));
2070 			if (error)
2071 				break;
2072 			if ((optval % 2) != 0) {
2073 				/* the API assumes even offset values */
2074 				error = EINVAL;
2075 			} else if (so->so_proto->pr_protocol ==
2076 			    IPPROTO_ICMPV6) {
2077 				if (optval != icmp6off)
2078 					error = EINVAL;
2079 			} else
2080 				in6p->in6p_cksum = optval;
2081 			break;
2082 
2083 		case SOPT_GET:
2084 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2085 				optval = icmp6off;
2086 			else
2087 				optval = in6p->in6p_cksum;
2088 
2089 			error = sooptcopyout(sopt, &optval, sizeof(optval));
2090 			break;
2091 
2092 		default:
2093 			error = EINVAL;
2094 			break;
2095 		}
2096 		break;
2097 
2098 	default:
2099 		error = ENOPROTOOPT;
2100 		break;
2101 	}
2102 
2103 	return (error);
2104 }
2105 
2106 /*
2107  * Set up IP6 options in pcb for insertion in output packets or
2108  * specifying behavior of outgoing packets.
2109  */
2110 static int
2111 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2112     struct socket *so, struct sockopt *sopt)
2113 {
2114 	struct ip6_pktopts *opt = *pktopt;
2115 	int error = 0;
2116 	struct thread *td = sopt->sopt_td;
2117 
2118 	/* turn off any old options. */
2119 	if (opt) {
2120 #ifdef DIAGNOSTIC
2121 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2122 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2123 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2124 			printf("ip6_pcbopts: all specified options are cleared.\n");
2125 #endif
2126 		ip6_clearpktopts(opt, -1);
2127 	} else
2128 		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2129 	*pktopt = NULL;
2130 
2131 	if (!m || m->m_len == 0) {
2132 		/*
2133 		 * Only turning off any previous options, regardless of
2134 		 * whether the opt is just created or given.
2135 		 */
2136 		free(opt, M_IP6OPT);
2137 		return (0);
2138 	}
2139 
2140 	/*  set options specified by user. */
2141 	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2142 	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2143 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2144 		free(opt, M_IP6OPT);
2145 		return (error);
2146 	}
2147 	*pktopt = opt;
2148 	return (0);
2149 }
2150 
2151 /*
2152  * initialize ip6_pktopts.  beware that there are non-zero default values in
2153  * the struct.
2154  */
2155 void
2156 ip6_initpktopts(struct ip6_pktopts *opt)
2157 {
2158 
2159 	bzero(opt, sizeof(*opt));
2160 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2161 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2162 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2163 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2164 }
2165 
2166 static int
2167 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2168     struct ucred *cred, int uproto)
2169 {
2170 	struct ip6_pktopts *opt;
2171 
2172 	if (*pktopt == NULL) {
2173 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2174 		    M_WAITOK);
2175 		ip6_initpktopts(*pktopt);
2176 	}
2177 	opt = *pktopt;
2178 
2179 	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2180 }
2181 
2182 static int
2183 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2184 {
2185 	void *optdata = NULL;
2186 	int optdatalen = 0;
2187 	struct ip6_ext *ip6e;
2188 	int error = 0;
2189 	struct in6_pktinfo null_pktinfo;
2190 	int deftclass = 0, on;
2191 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2192 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2193 
2194 	switch (optname) {
2195 	case IPV6_PKTINFO:
2196 		if (pktopt && pktopt->ip6po_pktinfo)
2197 			optdata = (void *)pktopt->ip6po_pktinfo;
2198 		else {
2199 			/* XXX: we don't have to do this every time... */
2200 			bzero(&null_pktinfo, sizeof(null_pktinfo));
2201 			optdata = (void *)&null_pktinfo;
2202 		}
2203 		optdatalen = sizeof(struct in6_pktinfo);
2204 		break;
2205 	case IPV6_TCLASS:
2206 		if (pktopt && pktopt->ip6po_tclass >= 0)
2207 			optdata = (void *)&pktopt->ip6po_tclass;
2208 		else
2209 			optdata = (void *)&deftclass;
2210 		optdatalen = sizeof(int);
2211 		break;
2212 	case IPV6_HOPOPTS:
2213 		if (pktopt && pktopt->ip6po_hbh) {
2214 			optdata = (void *)pktopt->ip6po_hbh;
2215 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2216 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2217 		}
2218 		break;
2219 	case IPV6_RTHDR:
2220 		if (pktopt && pktopt->ip6po_rthdr) {
2221 			optdata = (void *)pktopt->ip6po_rthdr;
2222 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2223 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2224 		}
2225 		break;
2226 	case IPV6_RTHDRDSTOPTS:
2227 		if (pktopt && pktopt->ip6po_dest1) {
2228 			optdata = (void *)pktopt->ip6po_dest1;
2229 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2230 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2231 		}
2232 		break;
2233 	case IPV6_DSTOPTS:
2234 		if (pktopt && pktopt->ip6po_dest2) {
2235 			optdata = (void *)pktopt->ip6po_dest2;
2236 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2237 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2238 		}
2239 		break;
2240 	case IPV6_NEXTHOP:
2241 		if (pktopt && pktopt->ip6po_nexthop) {
2242 			optdata = (void *)pktopt->ip6po_nexthop;
2243 			optdatalen = pktopt->ip6po_nexthop->sa_len;
2244 		}
2245 		break;
2246 	case IPV6_USE_MIN_MTU:
2247 		if (pktopt)
2248 			optdata = (void *)&pktopt->ip6po_minmtu;
2249 		else
2250 			optdata = (void *)&defminmtu;
2251 		optdatalen = sizeof(int);
2252 		break;
2253 	case IPV6_DONTFRAG:
2254 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2255 			on = 1;
2256 		else
2257 			on = 0;
2258 		optdata = (void *)&on;
2259 		optdatalen = sizeof(on);
2260 		break;
2261 	case IPV6_PREFER_TEMPADDR:
2262 		if (pktopt)
2263 			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2264 		else
2265 			optdata = (void *)&defpreftemp;
2266 		optdatalen = sizeof(int);
2267 		break;
2268 	default:		/* should not happen */
2269 #ifdef DIAGNOSTIC
2270 		panic("ip6_getpcbopt: unexpected option\n");
2271 #endif
2272 		return (ENOPROTOOPT);
2273 	}
2274 
2275 	error = sooptcopyout(sopt, optdata, optdatalen);
2276 
2277 	return (error);
2278 }
2279 
2280 void
2281 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2282 {
2283 	if (pktopt == NULL)
2284 		return;
2285 
2286 	if (optname == -1 || optname == IPV6_PKTINFO) {
2287 		if (pktopt->ip6po_pktinfo)
2288 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2289 		pktopt->ip6po_pktinfo = NULL;
2290 	}
2291 	if (optname == -1 || optname == IPV6_HOPLIMIT)
2292 		pktopt->ip6po_hlim = -1;
2293 	if (optname == -1 || optname == IPV6_TCLASS)
2294 		pktopt->ip6po_tclass = -1;
2295 	if (optname == -1 || optname == IPV6_NEXTHOP) {
2296 		if (pktopt->ip6po_nextroute.ro_rt) {
2297 			RTFREE(pktopt->ip6po_nextroute.ro_rt);
2298 			pktopt->ip6po_nextroute.ro_rt = NULL;
2299 		}
2300 		if (pktopt->ip6po_nexthop)
2301 			free(pktopt->ip6po_nexthop, M_IP6OPT);
2302 		pktopt->ip6po_nexthop = NULL;
2303 	}
2304 	if (optname == -1 || optname == IPV6_HOPOPTS) {
2305 		if (pktopt->ip6po_hbh)
2306 			free(pktopt->ip6po_hbh, M_IP6OPT);
2307 		pktopt->ip6po_hbh = NULL;
2308 	}
2309 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2310 		if (pktopt->ip6po_dest1)
2311 			free(pktopt->ip6po_dest1, M_IP6OPT);
2312 		pktopt->ip6po_dest1 = NULL;
2313 	}
2314 	if (optname == -1 || optname == IPV6_RTHDR) {
2315 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2316 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2317 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2318 		if (pktopt->ip6po_route.ro_rt) {
2319 			RTFREE(pktopt->ip6po_route.ro_rt);
2320 			pktopt->ip6po_route.ro_rt = NULL;
2321 		}
2322 	}
2323 	if (optname == -1 || optname == IPV6_DSTOPTS) {
2324 		if (pktopt->ip6po_dest2)
2325 			free(pktopt->ip6po_dest2, M_IP6OPT);
2326 		pktopt->ip6po_dest2 = NULL;
2327 	}
2328 }
2329 
2330 #define PKTOPT_EXTHDRCPY(type) \
2331 do {\
2332 	if (src->type) {\
2333 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2334 		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2335 		if (dst->type == NULL && canwait == M_NOWAIT)\
2336 			goto bad;\
2337 		bcopy(src->type, dst->type, hlen);\
2338 	}\
2339 } while (/*CONSTCOND*/ 0)
2340 
2341 static int
2342 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2343 {
2344 	if (dst == NULL || src == NULL)  {
2345 		printf("ip6_clearpktopts: invalid argument\n");
2346 		return (EINVAL);
2347 	}
2348 
2349 	dst->ip6po_hlim = src->ip6po_hlim;
2350 	dst->ip6po_tclass = src->ip6po_tclass;
2351 	dst->ip6po_flags = src->ip6po_flags;
2352 	dst->ip6po_minmtu = src->ip6po_minmtu;
2353 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2354 	if (src->ip6po_pktinfo) {
2355 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2356 		    M_IP6OPT, canwait);
2357 		if (dst->ip6po_pktinfo == NULL)
2358 			goto bad;
2359 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2360 	}
2361 	if (src->ip6po_nexthop) {
2362 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2363 		    M_IP6OPT, canwait);
2364 		if (dst->ip6po_nexthop == NULL)
2365 			goto bad;
2366 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2367 		    src->ip6po_nexthop->sa_len);
2368 	}
2369 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2370 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2371 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2372 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2373 	return (0);
2374 
2375   bad:
2376 	ip6_clearpktopts(dst, -1);
2377 	return (ENOBUFS);
2378 }
2379 #undef PKTOPT_EXTHDRCPY
2380 
2381 struct ip6_pktopts *
2382 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2383 {
2384 	int error;
2385 	struct ip6_pktopts *dst;
2386 
2387 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2388 	if (dst == NULL)
2389 		return (NULL);
2390 	ip6_initpktopts(dst);
2391 
2392 	if ((error = copypktopts(dst, src, canwait)) != 0) {
2393 		free(dst, M_IP6OPT);
2394 		return (NULL);
2395 	}
2396 
2397 	return (dst);
2398 }
2399 
2400 void
2401 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2402 {
2403 	if (pktopt == NULL)
2404 		return;
2405 
2406 	ip6_clearpktopts(pktopt, -1);
2407 
2408 	free(pktopt, M_IP6OPT);
2409 }
2410 
2411 /*
2412  * Set IPv6 outgoing packet options based on advanced API.
2413  */
2414 int
2415 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2416     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2417 {
2418 	struct cmsghdr *cm = 0;
2419 
2420 	if (control == NULL || opt == NULL)
2421 		return (EINVAL);
2422 
2423 	ip6_initpktopts(opt);
2424 	if (stickyopt) {
2425 		int error;
2426 
2427 		/*
2428 		 * If stickyopt is provided, make a local copy of the options
2429 		 * for this particular packet, then override them by ancillary
2430 		 * objects.
2431 		 * XXX: copypktopts() does not copy the cached route to a next
2432 		 * hop (if any).  This is not very good in terms of efficiency,
2433 		 * but we can allow this since this option should be rarely
2434 		 * used.
2435 		 */
2436 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2437 			return (error);
2438 	}
2439 
2440 	/*
2441 	 * XXX: Currently, we assume all the optional information is stored
2442 	 * in a single mbuf.
2443 	 */
2444 	if (control->m_next)
2445 		return (EINVAL);
2446 
2447 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2448 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2449 		int error;
2450 
2451 		if (control->m_len < CMSG_LEN(0))
2452 			return (EINVAL);
2453 
2454 		cm = mtod(control, struct cmsghdr *);
2455 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2456 			return (EINVAL);
2457 		if (cm->cmsg_level != IPPROTO_IPV6)
2458 			continue;
2459 
2460 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2461 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2462 		if (error)
2463 			return (error);
2464 	}
2465 
2466 	return (0);
2467 }
2468 
2469 /*
2470  * Set a particular packet option, as a sticky option or an ancillary data
2471  * item.  "len" can be 0 only when it's a sticky option.
2472  * We have 4 cases of combination of "sticky" and "cmsg":
2473  * "sticky=0, cmsg=0": impossible
2474  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2475  * "sticky=1, cmsg=0": RFC3542 socket option
2476  * "sticky=1, cmsg=1": RFC2292 socket option
2477  */
2478 static int
2479 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2480     struct ucred *cred, int sticky, int cmsg, int uproto)
2481 {
2482 	int minmtupolicy, preftemp;
2483 	int error;
2484 
2485 	if (!sticky && !cmsg) {
2486 #ifdef DIAGNOSTIC
2487 		printf("ip6_setpktopt: impossible case\n");
2488 #endif
2489 		return (EINVAL);
2490 	}
2491 
2492 	/*
2493 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2494 	 * not be specified in the context of RFC3542.  Conversely,
2495 	 * RFC3542 types should not be specified in the context of RFC2292.
2496 	 */
2497 	if (!cmsg) {
2498 		switch (optname) {
2499 		case IPV6_2292PKTINFO:
2500 		case IPV6_2292HOPLIMIT:
2501 		case IPV6_2292NEXTHOP:
2502 		case IPV6_2292HOPOPTS:
2503 		case IPV6_2292DSTOPTS:
2504 		case IPV6_2292RTHDR:
2505 		case IPV6_2292PKTOPTIONS:
2506 			return (ENOPROTOOPT);
2507 		}
2508 	}
2509 	if (sticky && cmsg) {
2510 		switch (optname) {
2511 		case IPV6_PKTINFO:
2512 		case IPV6_HOPLIMIT:
2513 		case IPV6_NEXTHOP:
2514 		case IPV6_HOPOPTS:
2515 		case IPV6_DSTOPTS:
2516 		case IPV6_RTHDRDSTOPTS:
2517 		case IPV6_RTHDR:
2518 		case IPV6_USE_MIN_MTU:
2519 		case IPV6_DONTFRAG:
2520 		case IPV6_TCLASS:
2521 		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2522 			return (ENOPROTOOPT);
2523 		}
2524 	}
2525 
2526 	switch (optname) {
2527 	case IPV6_2292PKTINFO:
2528 	case IPV6_PKTINFO:
2529 	{
2530 		struct ifnet *ifp = NULL;
2531 		struct in6_pktinfo *pktinfo;
2532 
2533 		if (len != sizeof(struct in6_pktinfo))
2534 			return (EINVAL);
2535 
2536 		pktinfo = (struct in6_pktinfo *)buf;
2537 
2538 		/*
2539 		 * An application can clear any sticky IPV6_PKTINFO option by
2540 		 * doing a "regular" setsockopt with ipi6_addr being
2541 		 * in6addr_any and ipi6_ifindex being zero.
2542 		 * [RFC 3542, Section 6]
2543 		 */
2544 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2545 		    pktinfo->ipi6_ifindex == 0 &&
2546 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2547 			ip6_clearpktopts(opt, optname);
2548 			break;
2549 		}
2550 
2551 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2552 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2553 			return (EINVAL);
2554 		}
2555 		if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2556 			return (EINVAL);
2557 		/* validate the interface index if specified. */
2558 		if (pktinfo->ipi6_ifindex > V_if_index)
2559 			 return (ENXIO);
2560 		if (pktinfo->ipi6_ifindex) {
2561 			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2562 			if (ifp == NULL)
2563 				return (ENXIO);
2564 		}
2565 		if (ifp != NULL && (
2566 		    ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED))
2567 			return (ENETDOWN);
2568 
2569 		if (ifp != NULL &&
2570 		    !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2571 			struct in6_ifaddr *ia;
2572 
2573 			ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2574 			if (ia == NULL)
2575 				return (EADDRNOTAVAIL);
2576 			ifa_free(&ia->ia_ifa);
2577 		}
2578 		/*
2579 		 * We store the address anyway, and let in6_selectsrc()
2580 		 * validate the specified address.  This is because ipi6_addr
2581 		 * may not have enough information about its scope zone, and
2582 		 * we may need additional information (such as outgoing
2583 		 * interface or the scope zone of a destination address) to
2584 		 * disambiguate the scope.
2585 		 * XXX: the delay of the validation may confuse the
2586 		 * application when it is used as a sticky option.
2587 		 */
2588 		if (opt->ip6po_pktinfo == NULL) {
2589 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2590 			    M_IP6OPT, M_NOWAIT);
2591 			if (opt->ip6po_pktinfo == NULL)
2592 				return (ENOBUFS);
2593 		}
2594 		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2595 		break;
2596 	}
2597 
2598 	case IPV6_2292HOPLIMIT:
2599 	case IPV6_HOPLIMIT:
2600 	{
2601 		int *hlimp;
2602 
2603 		/*
2604 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2605 		 * to simplify the ordering among hoplimit options.
2606 		 */
2607 		if (optname == IPV6_HOPLIMIT && sticky)
2608 			return (ENOPROTOOPT);
2609 
2610 		if (len != sizeof(int))
2611 			return (EINVAL);
2612 		hlimp = (int *)buf;
2613 		if (*hlimp < -1 || *hlimp > 255)
2614 			return (EINVAL);
2615 
2616 		opt->ip6po_hlim = *hlimp;
2617 		break;
2618 	}
2619 
2620 	case IPV6_TCLASS:
2621 	{
2622 		int tclass;
2623 
2624 		if (len != sizeof(int))
2625 			return (EINVAL);
2626 		tclass = *(int *)buf;
2627 		if (tclass < -1 || tclass > 255)
2628 			return (EINVAL);
2629 
2630 		opt->ip6po_tclass = tclass;
2631 		break;
2632 	}
2633 
2634 	case IPV6_2292NEXTHOP:
2635 	case IPV6_NEXTHOP:
2636 		if (cred != NULL) {
2637 			error = priv_check_cred(cred,
2638 			    PRIV_NETINET_SETHDROPTS, 0);
2639 			if (error)
2640 				return (error);
2641 		}
2642 
2643 		if (len == 0) {	/* just remove the option */
2644 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
2645 			break;
2646 		}
2647 
2648 		/* check if cmsg_len is large enough for sa_len */
2649 		if (len < sizeof(struct sockaddr) || len < *buf)
2650 			return (EINVAL);
2651 
2652 		switch (((struct sockaddr *)buf)->sa_family) {
2653 		case AF_INET6:
2654 		{
2655 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2656 			int error;
2657 
2658 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2659 				return (EINVAL);
2660 
2661 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2662 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2663 				return (EINVAL);
2664 			}
2665 			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2666 			    != 0) {
2667 				return (error);
2668 			}
2669 			break;
2670 		}
2671 		case AF_LINK:	/* should eventually be supported */
2672 		default:
2673 			return (EAFNOSUPPORT);
2674 		}
2675 
2676 		/* turn off the previous option, then set the new option. */
2677 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
2678 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2679 		if (opt->ip6po_nexthop == NULL)
2680 			return (ENOBUFS);
2681 		bcopy(buf, opt->ip6po_nexthop, *buf);
2682 		break;
2683 
2684 	case IPV6_2292HOPOPTS:
2685 	case IPV6_HOPOPTS:
2686 	{
2687 		struct ip6_hbh *hbh;
2688 		int hbhlen;
2689 
2690 		/*
2691 		 * XXX: We don't allow a non-privileged user to set ANY HbH
2692 		 * options, since per-option restriction has too much
2693 		 * overhead.
2694 		 */
2695 		if (cred != NULL) {
2696 			error = priv_check_cred(cred,
2697 			    PRIV_NETINET_SETHDROPTS, 0);
2698 			if (error)
2699 				return (error);
2700 		}
2701 
2702 		if (len == 0) {
2703 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
2704 			break;	/* just remove the option */
2705 		}
2706 
2707 		/* message length validation */
2708 		if (len < sizeof(struct ip6_hbh))
2709 			return (EINVAL);
2710 		hbh = (struct ip6_hbh *)buf;
2711 		hbhlen = (hbh->ip6h_len + 1) << 3;
2712 		if (len != hbhlen)
2713 			return (EINVAL);
2714 
2715 		/* turn off the previous option, then set the new option. */
2716 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
2717 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2718 		if (opt->ip6po_hbh == NULL)
2719 			return (ENOBUFS);
2720 		bcopy(hbh, opt->ip6po_hbh, hbhlen);
2721 
2722 		break;
2723 	}
2724 
2725 	case IPV6_2292DSTOPTS:
2726 	case IPV6_DSTOPTS:
2727 	case IPV6_RTHDRDSTOPTS:
2728 	{
2729 		struct ip6_dest *dest, **newdest = NULL;
2730 		int destlen;
2731 
2732 		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2733 			error = priv_check_cred(cred,
2734 			    PRIV_NETINET_SETHDROPTS, 0);
2735 			if (error)
2736 				return (error);
2737 		}
2738 
2739 		if (len == 0) {
2740 			ip6_clearpktopts(opt, optname);
2741 			break;	/* just remove the option */
2742 		}
2743 
2744 		/* message length validation */
2745 		if (len < sizeof(struct ip6_dest))
2746 			return (EINVAL);
2747 		dest = (struct ip6_dest *)buf;
2748 		destlen = (dest->ip6d_len + 1) << 3;
2749 		if (len != destlen)
2750 			return (EINVAL);
2751 
2752 		/*
2753 		 * Determine the position that the destination options header
2754 		 * should be inserted; before or after the routing header.
2755 		 */
2756 		switch (optname) {
2757 		case IPV6_2292DSTOPTS:
2758 			/*
2759 			 * The old advacned API is ambiguous on this point.
2760 			 * Our approach is to determine the position based
2761 			 * according to the existence of a routing header.
2762 			 * Note, however, that this depends on the order of the
2763 			 * extension headers in the ancillary data; the 1st
2764 			 * part of the destination options header must appear
2765 			 * before the routing header in the ancillary data,
2766 			 * too.
2767 			 * RFC3542 solved the ambiguity by introducing
2768 			 * separate ancillary data or option types.
2769 			 */
2770 			if (opt->ip6po_rthdr == NULL)
2771 				newdest = &opt->ip6po_dest1;
2772 			else
2773 				newdest = &opt->ip6po_dest2;
2774 			break;
2775 		case IPV6_RTHDRDSTOPTS:
2776 			newdest = &opt->ip6po_dest1;
2777 			break;
2778 		case IPV6_DSTOPTS:
2779 			newdest = &opt->ip6po_dest2;
2780 			break;
2781 		}
2782 
2783 		/* turn off the previous option, then set the new option. */
2784 		ip6_clearpktopts(opt, optname);
2785 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2786 		if (*newdest == NULL)
2787 			return (ENOBUFS);
2788 		bcopy(dest, *newdest, destlen);
2789 
2790 		break;
2791 	}
2792 
2793 	case IPV6_2292RTHDR:
2794 	case IPV6_RTHDR:
2795 	{
2796 		struct ip6_rthdr *rth;
2797 		int rthlen;
2798 
2799 		if (len == 0) {
2800 			ip6_clearpktopts(opt, IPV6_RTHDR);
2801 			break;	/* just remove the option */
2802 		}
2803 
2804 		/* message length validation */
2805 		if (len < sizeof(struct ip6_rthdr))
2806 			return (EINVAL);
2807 		rth = (struct ip6_rthdr *)buf;
2808 		rthlen = (rth->ip6r_len + 1) << 3;
2809 		if (len != rthlen)
2810 			return (EINVAL);
2811 
2812 		switch (rth->ip6r_type) {
2813 		case IPV6_RTHDR_TYPE_0:
2814 			if (rth->ip6r_len == 0)	/* must contain one addr */
2815 				return (EINVAL);
2816 			if (rth->ip6r_len % 2) /* length must be even */
2817 				return (EINVAL);
2818 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2819 				return (EINVAL);
2820 			break;
2821 		default:
2822 			return (EINVAL);	/* not supported */
2823 		}
2824 
2825 		/* turn off the previous option */
2826 		ip6_clearpktopts(opt, IPV6_RTHDR);
2827 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2828 		if (opt->ip6po_rthdr == NULL)
2829 			return (ENOBUFS);
2830 		bcopy(rth, opt->ip6po_rthdr, rthlen);
2831 
2832 		break;
2833 	}
2834 
2835 	case IPV6_USE_MIN_MTU:
2836 		if (len != sizeof(int))
2837 			return (EINVAL);
2838 		minmtupolicy = *(int *)buf;
2839 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2840 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
2841 		    minmtupolicy != IP6PO_MINMTU_ALL) {
2842 			return (EINVAL);
2843 		}
2844 		opt->ip6po_minmtu = minmtupolicy;
2845 		break;
2846 
2847 	case IPV6_DONTFRAG:
2848 		if (len != sizeof(int))
2849 			return (EINVAL);
2850 
2851 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2852 			/*
2853 			 * we ignore this option for TCP sockets.
2854 			 * (RFC3542 leaves this case unspecified.)
2855 			 */
2856 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2857 		} else
2858 			opt->ip6po_flags |= IP6PO_DONTFRAG;
2859 		break;
2860 
2861 	case IPV6_PREFER_TEMPADDR:
2862 		if (len != sizeof(int))
2863 			return (EINVAL);
2864 		preftemp = *(int *)buf;
2865 		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2866 		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2867 		    preftemp != IP6PO_TEMPADDR_PREFER) {
2868 			return (EINVAL);
2869 		}
2870 		opt->ip6po_prefer_tempaddr = preftemp;
2871 		break;
2872 
2873 	default:
2874 		return (ENOPROTOOPT);
2875 	} /* end of switch */
2876 
2877 	return (0);
2878 }
2879 
2880 /*
2881  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2882  * packet to the input queue of a specified interface.  Note that this
2883  * calls the output routine of the loopback "driver", but with an interface
2884  * pointer that might NOT be &loif -- easier than replicating that code here.
2885  */
2886 void
2887 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2888 {
2889 	struct mbuf *copym;
2890 	struct ip6_hdr *ip6;
2891 
2892 	copym = m_copy(m, 0, M_COPYALL);
2893 	if (copym == NULL)
2894 		return;
2895 
2896 	/*
2897 	 * Make sure to deep-copy IPv6 header portion in case the data
2898 	 * is in an mbuf cluster, so that we can safely override the IPv6
2899 	 * header portion later.
2900 	 */
2901 	if (!M_WRITABLE(copym) ||
2902 	    copym->m_len < sizeof(struct ip6_hdr)) {
2903 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
2904 		if (copym == NULL)
2905 			return;
2906 	}
2907 
2908 #ifdef DIAGNOSTIC
2909 	if (copym->m_len < sizeof(*ip6)) {
2910 		m_freem(copym);
2911 		return;
2912 	}
2913 #endif
2914 
2915 	ip6 = mtod(copym, struct ip6_hdr *);
2916 	/*
2917 	 * clear embedded scope identifiers if necessary.
2918 	 * in6_clearscope will touch the addresses only when necessary.
2919 	 */
2920 	in6_clearscope(&ip6->ip6_src);
2921 	in6_clearscope(&ip6->ip6_dst);
2922 
2923 	(void)if_simloop(ifp, copym, dst->sin6_family, 0);
2924 }
2925 
2926 /*
2927  * Chop IPv6 header off from the payload.
2928  */
2929 static int
2930 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
2931 {
2932 	struct mbuf *mh;
2933 	struct ip6_hdr *ip6;
2934 
2935 	ip6 = mtod(m, struct ip6_hdr *);
2936 	if (m->m_len > sizeof(*ip6)) {
2937 		mh = m_gethdr(M_NOWAIT, MT_DATA);
2938 		if (mh == NULL) {
2939 			m_freem(m);
2940 			return ENOBUFS;
2941 		}
2942 		m_move_pkthdr(mh, m);
2943 		MH_ALIGN(mh, sizeof(*ip6));
2944 		m->m_len -= sizeof(*ip6);
2945 		m->m_data += sizeof(*ip6);
2946 		mh->m_next = m;
2947 		m = mh;
2948 		m->m_len = sizeof(*ip6);
2949 		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
2950 	}
2951 	exthdrs->ip6e_ip6 = m;
2952 	return 0;
2953 }
2954 
2955 /*
2956  * Compute IPv6 extension header length.
2957  */
2958 int
2959 ip6_optlen(struct inpcb *in6p)
2960 {
2961 	int len;
2962 
2963 	if (!in6p->in6p_outputopts)
2964 		return 0;
2965 
2966 	len = 0;
2967 #define elen(x) \
2968     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
2969 
2970 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
2971 	if (in6p->in6p_outputopts->ip6po_rthdr)
2972 		/* dest1 is valid with rthdr only */
2973 		len += elen(in6p->in6p_outputopts->ip6po_dest1);
2974 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
2975 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
2976 	return len;
2977 #undef elen
2978 }
2979