xref: /dragonfly/sys/netinet6/ip6_output.c (revision ee48961f)
1 /*	$FreeBSD: src/sys/netinet6/ip6_output.c,v 1.13.2.18 2003/01/24 05:11:35 sam Exp $	*/
2 /*	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1988, 1990, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
62  */
63 
64 #include "opt_ip6fw.h"
65 #include "opt_inet.h"
66 #include "opt_inet6.h"
67 #include "opt_ipsec.h"
68 
69 #include <sys/param.h>
70 #include <sys/malloc.h>
71 #include <sys/mbuf.h>
72 #include <sys/errno.h>
73 #include <sys/protosw.h>
74 #include <sys/socket.h>
75 #include <sys/socketvar.h>
76 #include <sys/systm.h>
77 #include <sys/kernel.h>
78 #include <sys/proc.h>
79 #include <sys/priv.h>
80 
81 #include <sys/thread2.h>
82 #include <sys/msgport2.h>
83 
84 #include <net/if.h>
85 #include <net/route.h>
86 #include <net/pfil.h>
87 
88 #include <netinet/in.h>
89 #include <netinet/in_var.h>
90 #include <netinet6/in6_var.h>
91 #include <netinet/ip6.h>
92 #include <netinet/icmp6.h>
93 #include <netinet6/ip6_var.h>
94 #include <netinet/in_pcb.h>
95 #include <netinet6/nd6.h>
96 #include <netinet6/ip6protosw.h>
97 
98 #ifdef IPSEC
99 #include <netinet6/ipsec.h>
100 #ifdef INET6
101 #include <netinet6/ipsec6.h>
102 #endif
103 #include <netproto/key/key.h>
104 #endif /* IPSEC */
105 
106 #ifdef FAST_IPSEC
107 #include <netproto/ipsec/ipsec.h>
108 #include <netproto/ipsec/ipsec6.h>
109 #include <netproto/ipsec/key.h>
110 #endif
111 
112 #include <net/ip6fw/ip6_fw.h>
113 
114 #include <net/net_osdep.h>
115 
116 static MALLOC_DEFINE(M_IPMOPTS, "ip6_moptions", "internet multicast options");
117 
118 struct ip6_exthdrs {
119 	struct mbuf *ip6e_ip6;
120 	struct mbuf *ip6e_hbh;
121 	struct mbuf *ip6e_dest1;
122 	struct mbuf *ip6e_rthdr;
123 	struct mbuf *ip6e_dest2;
124 };
125 
126 static int ip6_pcbopt (int, u_char *, int, struct ip6_pktopts **, int);
127 static int ip6_setpktoption (int, u_char *, int, struct ip6_pktopts *,
128 	 int, int, int, int);
129 static int ip6_pcbopts (struct ip6_pktopts **, struct mbuf *,
130 			    struct socket *, struct sockopt *);
131 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
132 static int ip6_setmoptions (int, struct ip6_moptions **, struct mbuf *);
133 static int ip6_getmoptions (int, struct ip6_moptions *, struct mbuf **);
134 static int ip6_getpmtu(struct route_in6 *, struct route_in6 *,
135 	struct ifnet *, struct in6_addr *, u_long *, int *);
136 static int copyexthdr (void *, struct mbuf **);
137 static int ip6_insertfraghdr (struct mbuf *, struct mbuf *, int,
138 				  struct ip6_frag **);
139 static int ip6_insert_jumboopt (struct ip6_exthdrs *, u_int32_t);
140 static struct mbuf *ip6_splithdr (struct mbuf *);
141 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
142 
143 /*
144  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
145  * header (with pri, len, nxt, hlim, src, dst).
146  * This function may modify ver and hlim only.
147  * The mbuf chain containing the packet will be freed.
148  * The mbuf opt, if present, will not be freed.
149  *
150  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
151  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
152  * which is rt_rmx.rmx_mtu.
153  */
154 int
155 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt, struct route_in6 *ro,
156 	   int flags, struct ip6_moptions *im6o,
157 	   struct ifnet **ifpp,		/* XXX: just for statistics */
158 	   struct inpcb *inp)
159 {
160 	struct ip6_hdr *ip6, *mhip6;
161 	struct ifnet *ifp, *origifp;
162 	struct mbuf *m = m0;
163 	struct mbuf *mprev;
164 	u_char *nexthdrp;
165 	int hlen, tlen, len, off;
166 	struct route_in6 ip6route;
167 	struct sockaddr_in6 *dst;
168 	int error = 0;
169 	struct in6_ifaddr *ia = NULL;
170 	u_long mtu;
171 	int alwaysfrag, dontfrag;
172 	u_int32_t optlen, plen = 0, unfragpartlen;
173 	struct ip6_exthdrs exthdrs;
174 	struct in6_addr finaldst;
175 	struct route_in6 *ro_pmtu = NULL;
176 	boolean_t hdrsplit = FALSE;
177 	boolean_t needipsec = FALSE;
178 #ifdef IPSEC
179 	boolean_t needipsectun = FALSE;
180 	struct secpolicy *sp = NULL;
181 	struct socket *so = inp ? inp->inp_socket : NULL;
182 
183 	ip6 = mtod(m, struct ip6_hdr *);
184 #endif
185 #ifdef FAST_IPSEC
186 	boolean_t needipsectun = FALSE;
187 	struct secpolicy *sp = NULL;
188 
189 	ip6 = mtod(m, struct ip6_hdr *);
190 #endif
191 
192 	bzero(&exthdrs, sizeof exthdrs);
193 
194 	if (opt) {
195 		if ((error = copyexthdr(opt->ip6po_hbh, &exthdrs.ip6e_hbh)))
196 			goto freehdrs;
197 		if ((error = copyexthdr(opt->ip6po_dest1, &exthdrs.ip6e_dest1)))
198 			goto freehdrs;
199 		if ((error = copyexthdr(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr)))
200 			goto freehdrs;
201 		if ((error = copyexthdr(opt->ip6po_dest2, &exthdrs.ip6e_dest2)))
202 			goto freehdrs;
203 	}
204 
205 #ifdef IPSEC
206 	/* get a security policy for this packet */
207 	if (so == NULL)
208 		sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
209 	else
210 		sp = ipsec6_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
211 
212 	if (sp == NULL) {
213 		ipsec6stat.out_inval++;
214 		goto freehdrs;
215 	}
216 
217 	error = 0;
218 
219 	/* check policy */
220 	switch (sp->policy) {
221 	case IPSEC_POLICY_DISCARD:
222 		/*
223 		 * This packet is just discarded.
224 		 */
225 		ipsec6stat.out_polvio++;
226 		goto freehdrs;
227 
228 	case IPSEC_POLICY_BYPASS:
229 	case IPSEC_POLICY_NONE:
230 		/* no need to do IPsec. */
231 		needipsec = FALSE;
232 		break;
233 
234 	case IPSEC_POLICY_IPSEC:
235 		if (sp->req == NULL) {
236 			error = key_spdacquire(sp);	/* acquire a policy */
237 			goto freehdrs;
238 		}
239 		needipsec = TRUE;
240 		break;
241 
242 	case IPSEC_POLICY_ENTRUST:
243 	default:
244 		kprintf("ip6_output: Invalid policy found. %d\n", sp->policy);
245 	}
246 #endif /* IPSEC */
247 #ifdef FAST_IPSEC
248 	/* get a security policy for this packet */
249 	if (inp == NULL)
250 		sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
251 	else
252 		sp = ipsec_getpolicybysock(m, IPSEC_DIR_OUTBOUND, inp, &error);
253 
254 	if (sp == NULL) {
255 		newipsecstat.ips_out_inval++;
256 		goto freehdrs;
257 	}
258 
259 	error = 0;
260 
261 	/* check policy */
262 	switch (sp->policy) {
263 	case IPSEC_POLICY_DISCARD:
264 		/*
265 		 * This packet is just discarded.
266 		 */
267 		newipsecstat.ips_out_polvio++;
268 		goto freehdrs;
269 
270 	case IPSEC_POLICY_BYPASS:
271 	case IPSEC_POLICY_NONE:
272 		/* no need to do IPsec. */
273 		needipsec = FALSE;
274 		break;
275 
276 	case IPSEC_POLICY_IPSEC:
277 		if (sp->req == NULL) {
278 			error = key_spdacquire(sp);	/* acquire a policy */
279 			goto freehdrs;
280 		}
281 		needipsec = TRUE;
282 		break;
283 
284 	case IPSEC_POLICY_ENTRUST:
285 	default:
286 		kprintf("ip6_output: Invalid policy found. %d\n", sp->policy);
287 	}
288 #endif /* FAST_IPSEC */
289 
290 	/*
291 	 * Calculate the total length of the extension header chain.
292 	 * Keep the length of the unfragmentable part for fragmentation.
293 	 */
294 	optlen = m_lengthm(exthdrs.ip6e_hbh, NULL) +
295 	    m_lengthm(exthdrs.ip6e_dest1, NULL) +
296 	    m_lengthm(exthdrs.ip6e_rthdr, NULL);
297 
298 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
299 
300 	/* NOTE: we don't add AH/ESP length here. do that later. */
301 	optlen += m_lengthm(exthdrs.ip6e_dest2, NULL);
302 
303 	/*
304 	 * If we need IPsec, or there is at least one extension header,
305 	 * separate IP6 header from the payload.
306 	 */
307 	if ((needipsec || optlen) && !hdrsplit) {
308 		exthdrs.ip6e_ip6 = ip6_splithdr(m);
309 		if (exthdrs.ip6e_ip6 == NULL) {
310 			error = ENOBUFS;
311 			goto freehdrs;
312 		}
313 		m = exthdrs.ip6e_ip6;
314 		hdrsplit = TRUE;
315 	}
316 
317 	/* adjust pointer */
318 	ip6 = mtod(m, struct ip6_hdr *);
319 
320 	/* adjust mbuf packet header length */
321 	m->m_pkthdr.len += optlen;
322 	plen = m->m_pkthdr.len - sizeof(*ip6);
323 
324 	/* If this is a jumbo payload, insert a jumbo payload option. */
325 	if (plen > IPV6_MAXPACKET) {
326 		if (!hdrsplit) {
327 			exthdrs.ip6e_ip6 = ip6_splithdr(m);
328 			if (exthdrs.ip6e_ip6 == NULL) {
329 				error = ENOBUFS;
330 				goto freehdrs;
331 			}
332 			m = exthdrs.ip6e_ip6;
333 			hdrsplit = TRUE;
334 		}
335 		/* adjust pointer */
336 		ip6 = mtod(m, struct ip6_hdr *);
337 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
338 			goto freehdrs;
339 		ip6->ip6_plen = 0;
340 	} else
341 		ip6->ip6_plen = htons(plen);
342 
343 	/*
344 	 * Concatenate headers and fill in next header fields.
345 	 * Here we have, on "m"
346 	 *	IPv6 payload
347 	 * and we insert headers accordingly.  Finally, we should be getting:
348 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
349 	 *
350 	 * during the header composing process, "m" points to IPv6 header.
351 	 * "mprev" points to an extension header prior to esp.
352 	 */
353 
354 	nexthdrp = &ip6->ip6_nxt;
355 	mprev = m;
356 
357 	/*
358 	 * we treat dest2 specially.  this makes IPsec processing
359 	 * much easier.  the goal here is to make mprev point the
360 	 * mbuf prior to dest2.
361 	 *
362 	 * result: IPv6 dest2 payload
363 	 * m and mprev will point to IPv6 header.
364 	 */
365 	if (exthdrs.ip6e_dest2) {
366 		if (!hdrsplit)
367 			panic("assumption failed: hdr not split");
368 		exthdrs.ip6e_dest2->m_next = m->m_next;
369 		m->m_next = exthdrs.ip6e_dest2;
370 		*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
371 		ip6->ip6_nxt = IPPROTO_DSTOPTS;
372 	}
373 
374 /*
375  * Place m1 after mprev.
376  */
377 #define MAKE_CHAIN(m1, mprev, nexthdrp, i)\
378     do {\
379 	if (m1) {\
380 		if (!hdrsplit)\
381 			panic("assumption failed: hdr not split");\
382 		*mtod(m1, u_char *) = *nexthdrp;\
383 		*nexthdrp = (i);\
384 		nexthdrp = mtod(m1, u_char *);\
385 		m1->m_next = mprev->m_next;\
386 		mprev->m_next = m1;\
387 		mprev = m1;\
388 	}\
389     } while (0)
390 
391 	/*
392 	 * result: IPv6 hbh dest1 rthdr dest2 payload
393 	 * m will point to IPv6 header.  mprev will point to the
394 	 * extension header prior to dest2 (rthdr in the above case).
395 	 */
396 	MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
397 	MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp, IPPROTO_DSTOPTS);
398 	MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp, IPPROTO_ROUTING);
399 
400 #if defined(IPSEC) || defined(FAST_IPSEC)
401 	if (needipsec) {
402 		struct ipsec_output_state state;
403 		int segleft_org = 0;
404 		struct ip6_rthdr *rh = NULL;
405 
406 		/*
407 		 * pointers after IPsec headers are not valid any more.
408 		 * other pointers need a great care too.
409 		 * (IPsec routines should not mangle mbufs prior to AH/ESP)
410 		 */
411 		exthdrs.ip6e_dest2 = NULL;
412 
413 		if (exthdrs.ip6e_rthdr) {
414 			rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
415 			segleft_org = rh->ip6r_segleft;
416 			rh->ip6r_segleft = 0;
417 		}
418 
419 		bzero(&state, sizeof state);
420 		state.m = m;
421 		error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
422 					    &needipsectun);
423 		m = state.m;
424 		if (error) {
425 			/* mbuf is already reclaimed in ipsec6_output_trans. */
426 			m = NULL;
427 			switch (error) {
428 			case EHOSTUNREACH:
429 			case ENETUNREACH:
430 			case EMSGSIZE:
431 			case ENOBUFS:
432 			case ENOMEM:
433 				break;
434 			default:
435 				kprintf("ip6_output (ipsec): error code %d\n",
436 				       error);
437 				/* fall through */
438 			case ENOENT:
439 				/* don't show these error codes to the user */
440 				error = 0;
441 				break;
442 			}
443 			goto bad;
444 		}
445 		if (exthdrs.ip6e_rthdr) {
446 			/* ah6_output doesn't modify mbuf chain */
447 			rh->ip6r_segleft = segleft_org;
448 		}
449 	}
450 #endif
451 
452 	/*
453 	 * If there is a routing header, replace destination address field
454 	 * with the first hop of the routing header.
455 	 */
456 	if (exthdrs.ip6e_rthdr) {
457 		struct ip6_rthdr *rh;
458 
459 		finaldst = ip6->ip6_dst;
460 		rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
461 		switch (rh->ip6r_type) {
462 		default:	/* is it possible? */
463 			 error = EINVAL;
464 			 goto bad;
465 		}
466 	}
467 
468 	/* Source address validation */
469 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
470 	    !(flags & IPV6_DADOUTPUT)) {
471 		error = EOPNOTSUPP;
472 		ip6stat.ip6s_badscope++;
473 		goto bad;
474 	}
475 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
476 		error = EOPNOTSUPP;
477 		ip6stat.ip6s_badscope++;
478 		goto bad;
479 	}
480 
481 	ip6stat.ip6s_localout++;
482 
483 	/*
484 	 * Route packet.
485 	 */
486 	if (ro == NULL) {
487 		ro = &ip6route;
488 		bzero(ro, sizeof(*ro));
489 	}
490 	ro_pmtu = ro;
491 	if (opt && opt->ip6po_rthdr)
492 		ro = &opt->ip6po_route;
493 	dst = (struct sockaddr_in6 *)&ro->ro_dst;
494 	/*
495 	 * If there is a cached route,
496 	 * check that it is to the same destination
497 	 * and is still up. If not, free it and try again.
498 	 */
499 	if (ro->ro_rt != NULL &&
500 	    (!(ro->ro_rt->rt_flags & RTF_UP) || dst->sin6_family != AF_INET6 ||
501 	     !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_dst))) {
502 		RTFREE(ro->ro_rt);
503 		ro->ro_rt = NULL;
504 	}
505 	if (ro->ro_rt == NULL) {
506 		bzero(dst, sizeof(*dst));
507 		dst->sin6_family = AF_INET6;
508 		dst->sin6_len = sizeof(struct sockaddr_in6);
509 		dst->sin6_addr = ip6->ip6_dst;
510 	}
511 #if defined(IPSEC) || defined(FAST_IPSEC)
512 	if (needipsec && needipsectun) {
513 		struct ipsec_output_state state;
514 
515 		/*
516 		 * All the extension headers will become inaccessible
517 		 * (since they can be encrypted).
518 		 * Don't panic, we need no more updates to extension headers
519 		 * on inner IPv6 packet (since they are now encapsulated).
520 		 *
521 		 * IPv6 [ESP|AH] IPv6 [extension headers] payload
522 		 */
523 		bzero(&exthdrs, sizeof(exthdrs));
524 		exthdrs.ip6e_ip6 = m;
525 
526 		bzero(&state, sizeof(state));
527 		state.m = m;
528 		state.ro = (struct route *)ro;
529 		state.dst = (struct sockaddr *)dst;
530 
531 		error = ipsec6_output_tunnel(&state, sp, flags);
532 
533 		m = state.m;
534 		ro = (struct route_in6 *)state.ro;
535 		dst = (struct sockaddr_in6 *)state.dst;
536 		if (error) {
537 			/* mbuf is already reclaimed in ipsec6_output_tunnel. */
538 			m0 = m = NULL;
539 			m = NULL;
540 			switch (error) {
541 			case EHOSTUNREACH:
542 			case ENETUNREACH:
543 			case EMSGSIZE:
544 			case ENOBUFS:
545 			case ENOMEM:
546 				break;
547 			default:
548 				kprintf("ip6_output (ipsec): error code %d\n", error);
549 				/* fall through */
550 			case ENOENT:
551 				/* don't show these error codes to the user */
552 				error = 0;
553 				break;
554 			}
555 			goto bad;
556 		}
557 
558 		exthdrs.ip6e_ip6 = m;
559 	}
560 #endif
561 
562 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
563 		/* Unicast */
564 
565 #define ifatoia6(ifa)	((struct in6_ifaddr *)(ifa))
566 #define sin6tosa(sin6)	((struct sockaddr *)(sin6))
567 		/* xxx
568 		 * interface selection comes here
569 		 * if an interface is specified from an upper layer,
570 		 * ifp must point it.
571 		 */
572 		if (ro->ro_rt == NULL) {
573 			/*
574 			 * non-bsdi always clone routes, if parent is
575 			 * PRF_CLONING.
576 			 */
577 			rtalloc((struct route *)ro);
578 		}
579 		if (ro->ro_rt == NULL) {
580 			ip6stat.ip6s_noroute++;
581 			error = EHOSTUNREACH;
582 			/* XXX in6_ifstat_inc(ifp, ifs6_out_discard); */
583 			goto bad;
584 		}
585 		ia = ifatoia6(ro->ro_rt->rt_ifa);
586 		ifp = ro->ro_rt->rt_ifp;
587 		ro->ro_rt->rt_use++;
588 		if (ro->ro_rt->rt_flags & RTF_GATEWAY)
589 			dst = (struct sockaddr_in6 *)ro->ro_rt->rt_gateway;
590 		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
591 
592 		in6_ifstat_inc(ifp, ifs6_out_request);
593 
594 		/*
595 		 * Check if the outgoing interface conflicts with
596 		 * the interface specified by ifi6_ifindex (if specified).
597 		 * Note that loopback interface is always okay.
598 		 * (this may happen when we are sending a packet to one of
599 		 *  our own addresses.)
600 		 */
601 		if (opt && opt->ip6po_pktinfo
602 		 && opt->ip6po_pktinfo->ipi6_ifindex) {
603 			if (!(ifp->if_flags & IFF_LOOPBACK)
604 			 && ifp->if_index != opt->ip6po_pktinfo->ipi6_ifindex) {
605 				ip6stat.ip6s_noroute++;
606 				in6_ifstat_inc(ifp, ifs6_out_discard);
607 				error = EHOSTUNREACH;
608 				goto bad;
609 			}
610 		}
611 
612 		if (opt && opt->ip6po_hlim != -1)
613 			ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
614 	} else {
615 		/* Multicast */
616 		struct	in6_multi *in6m;
617 
618 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
619 
620 		/*
621 		 * See if the caller provided any multicast options
622 		 */
623 		ifp = NULL;
624 		if (im6o != NULL) {
625 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
626 			if (im6o->im6o_multicast_ifp != NULL)
627 				ifp = im6o->im6o_multicast_ifp;
628 		} else
629 			ip6->ip6_hlim = ip6_defmcasthlim;
630 
631 		/*
632 		 * See if the caller provided the outgoing interface
633 		 * as an ancillary data.
634 		 * Boundary check for ifindex is assumed to be already done.
635 		 */
636 		if (opt && opt->ip6po_pktinfo && opt->ip6po_pktinfo->ipi6_ifindex)
637 			ifp = ifindex2ifnet[opt->ip6po_pktinfo->ipi6_ifindex];
638 
639 		/*
640 		 * If the destination is a node-local scope multicast,
641 		 * the packet should be loop-backed only.
642 		 */
643 		if (IN6_IS_ADDR_MC_NODELOCAL(&ip6->ip6_dst)) {
644 			/*
645 			 * If the outgoing interface is already specified,
646 			 * it should be a loopback interface.
647 			 */
648 			if (ifp && !(ifp->if_flags & IFF_LOOPBACK)) {
649 				ip6stat.ip6s_badscope++;
650 				error = ENETUNREACH; /* XXX: better error? */
651 				/* XXX correct ifp? */
652 				in6_ifstat_inc(ifp, ifs6_out_discard);
653 				goto bad;
654 			} else {
655 				ifp = &loif[0];
656 			}
657 		}
658 
659 		if (opt && opt->ip6po_hlim != -1)
660 			ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
661 
662 		/*
663 		 * If caller did not provide an interface lookup a
664 		 * default in the routing table.  This is either a
665 		 * default for the speicfied group (i.e. a host
666 		 * route), or a multicast default (a route for the
667 		 * ``net'' ff00::/8).
668 		 */
669 		if (ifp == NULL) {
670 			if (ro->ro_rt == NULL) {
671 				ro->ro_rt =
672 				  rtpurelookup((struct sockaddr *)&ro->ro_dst);
673 			}
674 			if (ro->ro_rt == NULL) {
675 				ip6stat.ip6s_noroute++;
676 				error = EHOSTUNREACH;
677 				/* XXX in6_ifstat_inc(ifp, ifs6_out_discard) */
678 				goto bad;
679 			}
680 			ia = ifatoia6(ro->ro_rt->rt_ifa);
681 			ifp = ro->ro_rt->rt_ifp;
682 			ro->ro_rt->rt_use++;
683 		}
684 
685 		if (!(flags & IPV6_FORWARDING))
686 			in6_ifstat_inc(ifp, ifs6_out_request);
687 		in6_ifstat_inc(ifp, ifs6_out_mcast);
688 
689 		/*
690 		 * Confirm that the outgoing interface supports multicast.
691 		 */
692 		if (!(ifp->if_flags & IFF_MULTICAST)) {
693 			ip6stat.ip6s_noroute++;
694 			in6_ifstat_inc(ifp, ifs6_out_discard);
695 			error = ENETUNREACH;
696 			goto bad;
697 		}
698 		IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
699 		if (in6m != NULL &&
700 		   (im6o == NULL || im6o->im6o_multicast_loop)) {
701 			/*
702 			 * If we belong to the destination multicast group
703 			 * on the outgoing interface, and the caller did not
704 			 * forbid loopback, loop back a copy.
705 			 */
706 			ip6_mloopback(ifp, m, dst);
707 		} else {
708 			/*
709 			 * If we are acting as a multicast router, perform
710 			 * multicast forwarding as if the packet had just
711 			 * arrived on the interface to which we are about
712 			 * to send.  The multicast forwarding function
713 			 * recursively calls this function, using the
714 			 * IPV6_FORWARDING flag to prevent infinite recursion.
715 			 *
716 			 * Multicasts that are looped back by ip6_mloopback(),
717 			 * above, will be forwarded by the ip6_input() routine,
718 			 * if necessary.
719 			 */
720 			if (ip6_mrouter && !(flags & IPV6_FORWARDING)) {
721 				if (ip6_mforward(ip6, ifp, m) != 0) {
722 					m_freem(m);
723 					goto done;
724 				}
725 			}
726 		}
727 		/*
728 		 * Multicasts with a hoplimit of zero may be looped back,
729 		 * above, but must not be transmitted on a network.
730 		 * Also, multicasts addressed to the loopback interface
731 		 * are not sent -- the above call to ip6_mloopback() will
732 		 * loop back a copy if this host actually belongs to the
733 		 * destination group on the loopback interface.
734 		 */
735 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK)) {
736 			m_freem(m);
737 			goto done;
738 		}
739 	}
740 
741 	/*
742 	 * Fill the outgoing inteface to tell the upper layer
743 	 * to increment per-interface statistics.
744 	 */
745 	if (ifpp)
746 		*ifpp = ifp;
747 
748 	/* Determine path MTU. */
749 	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
750 	    &alwaysfrag)) != 0)
751 		goto bad;
752 
753 	/*
754 	 * The caller of this function may specify to use the minimum MTU
755 	 * in some cases.
756 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
757 	 * setting.  The logic is a bit complicated; by default, unicast
758 	 * packets will follow path MTU while multicast packets will be sent at
759 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
760 	 * including unicast ones will be sent at the minimum MTU.  Multicast
761 	 * packets will always be sent at the minimum MTU unless
762 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
763 	 * See RFC 3542 for more details.
764 	 */
765 	if (mtu > IPV6_MMTU) {
766 		if ((flags & IPV6_MINMTU))
767 			mtu = IPV6_MMTU;
768 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
769 			mtu = IPV6_MMTU;
770 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
771 			 (opt == NULL ||
772 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
773 			mtu = IPV6_MMTU;
774 		}
775 	}
776 
777 	/* Fake scoped addresses */
778 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
779 		/*
780 		 * If source or destination address is a scoped address, and
781 		 * the packet is going to be sent to a loopback interface,
782 		 * we should keep the original interface.
783 		 */
784 
785 		/*
786 		 * XXX: this is a very experimental and temporary solution.
787 		 * We eventually have sockaddr_in6 and use the sin6_scope_id
788 		 * field of the structure here.
789 		 * We rely on the consistency between two scope zone ids
790 		 * of source and destination, which should already be assured.
791 		 * Larger scopes than link will be supported in the future.
792 		 */
793 		origifp = NULL;
794 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
795 			origifp = ifindex2ifnet[ntohs(ip6->ip6_src.s6_addr16[1])];
796 		else if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
797 			origifp = ifindex2ifnet[ntohs(ip6->ip6_dst.s6_addr16[1])];
798 		/*
799 		 * XXX: origifp can be NULL even in those two cases above.
800 		 * For example, if we remove the (only) link-local address
801 		 * from the loopback interface, and try to send a link-local
802 		 * address without link-id information.  Then the source
803 		 * address is ::1, and the destination address is the
804 		 * link-local address with its s6_addr16[1] being zero.
805 		 * What is worse, if the packet goes to the loopback interface
806 		 * by a default rejected route, the null pointer would be
807 		 * passed to looutput, and the kernel would hang.
808 		 * The following last resort would prevent such disaster.
809 		 */
810 		if (origifp == NULL)
811 			origifp = ifp;
812 	}
813 	else
814 		origifp = ifp;
815 	/*
816 	 * clear embedded scope identifiers if necessary.
817 	 * in6_clearscope will touch the addresses only when necessary.
818 	 */
819 	in6_clearscope(&ip6->ip6_src);
820 	in6_clearscope(&ip6->ip6_dst);
821 
822 	/*
823 	 * Check with the firewall...
824 	 */
825 	if (ip6_fw_enable && ip6_fw_chk_ptr) {
826 		u_short port = 0;
827 
828 		m->m_pkthdr.rcvif = NULL;	/* XXX */
829 		/* If ipfw says divert, we have to just drop packet */
830 		if ((*ip6_fw_chk_ptr)(&ip6, ifp, &port, &m)) {
831 			m_freem(m);
832 			goto done;
833 		}
834 		if (!m) {
835 			error = EACCES;
836 			goto done;
837 		}
838 	}
839 
840 	/*
841 	 * If the outgoing packet contains a hop-by-hop options header,
842 	 * it must be examined and processed even by the source node.
843 	 * (RFC 2460, section 4.)
844 	 */
845 	if (exthdrs.ip6e_hbh) {
846 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
847 		u_int32_t dummy1; /* XXX unused */
848 		u_int32_t dummy2; /* XXX unused */
849 
850 #ifdef DIAGNOSTIC
851 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
852 			panic("ip6e_hbh is not continuous");
853 #endif
854 		/*
855 		 *  XXX: if we have to send an ICMPv6 error to the sender,
856 		 *       we need the M_LOOP flag since icmp6_error() expects
857 		 *       the IPv6 and the hop-by-hop options header are
858 		 *       continuous unless the flag is set.
859 		 */
860 		m->m_flags |= M_LOOP;
861 		m->m_pkthdr.rcvif = ifp;
862 		if (ip6_process_hopopts(m,
863 					(u_int8_t *)(hbh + 1),
864 					((hbh->ip6h_len + 1) << 3) -
865 					sizeof(struct ip6_hbh),
866 					&dummy1, &dummy2) < 0) {
867 			/* m was already freed at this point */
868 			error = EINVAL;/* better error? */
869 			goto done;
870 		}
871 		m->m_flags &= ~M_LOOP; /* XXX */
872 		m->m_pkthdr.rcvif = NULL;
873 	}
874 
875 	/*
876 	 * Run through list of hooks for output packets.
877 	 */
878 	if (pfil_has_hooks(&inet6_pfil_hook)) {
879 		error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT);
880 		if (error != 0 || m == NULL)
881 			goto done;
882 		ip6 = mtod(m, struct ip6_hdr *);
883 	}
884 
885 	/*
886 	 * Send the packet to the outgoing interface.
887 	 * If necessary, do IPv6 fragmentation before sending.
888 	 *
889 	 * the logic here is rather complex:
890 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
891 	 * 1-a:	send as is if tlen <= path mtu
892 	 * 1-b:	fragment if tlen > path mtu
893 	 *
894 	 * 2: if user asks us not to fragment (dontfrag == 1)
895 	 * 2-a:	send as is if tlen <= interface mtu
896 	 * 2-b:	error if tlen > interface mtu
897 	 *
898 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
899 	 *	always fragment
900 	 *
901 	 * 4: if dontfrag == 1 && alwaysfrag == 1
902 	 *	error, as we cannot handle this conflicting request
903 	 */
904 	tlen = m->m_pkthdr.len;
905 
906 	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
907 		dontfrag = 1;
908 	else
909 		dontfrag = 0;
910 	if (dontfrag && alwaysfrag) {	/* case 4 */
911 		/* conflicting request - can't transmit */
912 		error = EMSGSIZE;
913 		goto bad;
914 	}
915 	if (dontfrag && tlen > IN6_LINKMTU(ifp)) {	/* case 2-b */
916 		/*
917 		 * Even if the DONTFRAG option is specified, we cannot send the
918 		 * packet when the data length is larger than the MTU of the
919 		 * outgoing interface.
920 		 * Notify the error by sending IPV6_PATHMTU ancillary data as
921 		 * well as returning an error code (the latter is not described
922 		 * in the API spec.)
923 		 */
924 		u_int32_t mtu32;
925 		struct ip6ctlparam ip6cp;
926 
927 		mtu32 = (u_int32_t)mtu;
928 		bzero(&ip6cp, sizeof(ip6cp));
929 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
930 		kpfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
931 		    (void *)&ip6cp);
932 
933 		error = EMSGSIZE;
934 		goto bad;
935 	}
936 
937 	/*
938 	 * transmit packet without fragmentation
939 	 */
940 	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* case 1-a and 2-a */
941 		struct in6_ifaddr *ia6;
942 
943 		ip6 = mtod(m, struct ip6_hdr *);
944 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
945 		if (ia6) {
946 			/* Record statistics for this interface address. */
947 			IFA_STAT_INC(&ia6->ia_ifa, opackets, 1);
948 			IFA_STAT_INC(&ia6->ia_ifa, obytes, m->m_pkthdr.len);
949 		}
950 #ifdef IPSEC
951 		/* clean ipsec history once it goes out of the node */
952 		ipsec_delaux(m);
953 #endif
954 		error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
955 		goto done;
956 	}
957 
958 	/*
959 	 * try to fragment the packet.  case 1-b and 3
960 	 */
961 	if (mtu < IPV6_MMTU) {
962 		/*
963 		 * note that path MTU is never less than IPV6_MMTU
964 		 * (see icmp6_input).
965 		 */
966 		error = EMSGSIZE;
967 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
968 		goto bad;
969 	} else if (ip6->ip6_plen == 0) { /* jumbo payload cannot be fragmented */
970 		error = EMSGSIZE;
971 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
972 		goto bad;
973 	} else {
974 		struct mbuf **mnext, *m_frgpart;
975 		struct ip6_frag *ip6f;
976 		u_int32_t id = htonl(ip6_id++);
977 		u_char nextproto;
978 
979 		/*
980 		 * Too large for the destination or interface;
981 		 * fragment if possible.
982 		 * Must be able to put at least 8 bytes per fragment.
983 		 */
984 		hlen = unfragpartlen;
985 		if (mtu > IPV6_MAXPACKET)
986 			mtu = IPV6_MAXPACKET;
987 
988 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
989 		if (len < 8) {
990 			error = EMSGSIZE;
991 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
992 			goto bad;
993 		}
994 
995 		mnext = &m->m_nextpkt;
996 
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 		for (off = hlen; off < tlen; off += len) {
1022 			MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1023 			if (!m) {
1024 				error = ENOBUFS;
1025 				ip6stat.ip6s_odropped++;
1026 				goto sendorfree;
1027 			}
1028 			m->m_pkthdr.rcvif = NULL;
1029 			m->m_flags = m0->m_flags & M_COPYFLAGS;
1030 			*mnext = m;
1031 			mnext = &m->m_nextpkt;
1032 			m->m_data += max_linkhdr;
1033 			mhip6 = mtod(m, struct ip6_hdr *);
1034 			*mhip6 = *ip6;
1035 			m->m_len = sizeof(*mhip6);
1036  			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1037  			if (error) {
1038 				ip6stat.ip6s_odropped++;
1039 				goto sendorfree;
1040 			}
1041 			ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1042 			if (off + len >= tlen)
1043 				len = tlen - off;
1044 			else
1045 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1046 			mhip6->ip6_plen = htons((u_short)(len + hlen +
1047 							  sizeof(*ip6f) -
1048 							  sizeof(struct ip6_hdr)));
1049 			if ((m_frgpart = m_copy(m0, off, len)) == NULL) {
1050 				error = ENOBUFS;
1051 				ip6stat.ip6s_odropped++;
1052 				goto sendorfree;
1053 			}
1054 			m_cat(m, m_frgpart);
1055 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1056 			m->m_pkthdr.rcvif = NULL;
1057 			ip6f->ip6f_reserved = 0;
1058 			ip6f->ip6f_ident = id;
1059 			ip6f->ip6f_nxt = nextproto;
1060 			ip6stat.ip6s_ofragments++;
1061 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1062 		}
1063 
1064 		in6_ifstat_inc(ifp, ifs6_out_fragok);
1065 	}
1066 
1067 	/*
1068 	 * Remove leading garbages.
1069 	 */
1070 sendorfree:
1071 	m = m0->m_nextpkt;
1072 	m0->m_nextpkt = NULL;
1073 	m_freem(m0);
1074 	for (m0 = m; m; m = m0) {
1075 		m0 = m->m_nextpkt;
1076 		m->m_nextpkt = NULL;
1077 		if (error == 0) {
1078  			/* Record statistics for this interface address. */
1079  			if (ia) {
1080  				IFA_STAT_INC(&ia->ia_ifa, opackets, 1);
1081  				IFA_STAT_INC(&ia->ia_ifa, obytes,
1082 				    m->m_pkthdr.len);
1083  			}
1084 #ifdef IPSEC
1085 			/* clean ipsec history once it goes out of the node */
1086 			ipsec_delaux(m);
1087 #endif
1088 			error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1089 		} else
1090 			m_freem(m);
1091 	}
1092 
1093 	if (error == 0)
1094 		ip6stat.ip6s_fragmented++;
1095 
1096 done:
1097 	if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
1098 		RTFREE(ro->ro_rt);
1099 	} else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
1100 		RTFREE(ro_pmtu->ro_rt);
1101 	}
1102 
1103 #ifdef IPSEC
1104 	if (sp != NULL)
1105 		key_freesp(sp);
1106 #endif
1107 #ifdef FAST_IPSEC
1108 	if (sp != NULL)
1109 		KEY_FREESP(&sp);
1110 #endif
1111 
1112 	return (error);
1113 
1114 freehdrs:
1115 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
1116 	m_freem(exthdrs.ip6e_dest1);
1117 	m_freem(exthdrs.ip6e_rthdr);
1118 	m_freem(exthdrs.ip6e_dest2);
1119 	/* fall through */
1120 bad:
1121 	m_freem(m);
1122 	goto done;
1123 }
1124 
1125 static int
1126 copyexthdr(void *h, struct mbuf **mp)
1127 {
1128 	struct ip6_ext *hdr = h;
1129 	int hlen;
1130 	struct mbuf *m;
1131 
1132 	if (hdr == NULL)
1133 		return 0;
1134 
1135 	hlen = (hdr->ip6e_len + 1) * 8;
1136 	if (hlen > MCLBYTES)
1137 		return ENOBUFS;	/* XXX */
1138 
1139 	m = m_getb(hlen, MB_DONTWAIT, MT_DATA, 0);
1140 	if (!m)
1141 		return ENOBUFS;
1142 	m->m_len = hlen;
1143 
1144 	bcopy(hdr, mtod(m, caddr_t), hlen);
1145 
1146 	*mp = m;
1147 	return 0;
1148 }
1149 
1150 /*
1151  * Insert jumbo payload option.
1152  */
1153 static int
1154 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1155 {
1156 	struct mbuf *mopt;
1157 	u_char *optbuf;
1158 	u_int32_t v;
1159 
1160 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1161 
1162 	/*
1163 	 * If there is no hop-by-hop options header, allocate new one.
1164 	 * If there is one but it doesn't have enough space to store the
1165 	 * jumbo payload option, allocate a cluster to store the whole options.
1166 	 * Otherwise, use it to store the options.
1167 	 */
1168 	if (exthdrs->ip6e_hbh == NULL) {
1169 		MGET(mopt, MB_DONTWAIT, MT_DATA);
1170 		if (mopt == NULL)
1171 			return (ENOBUFS);
1172 		mopt->m_len = JUMBOOPTLEN;
1173 		optbuf = mtod(mopt, u_char *);
1174 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1175 		exthdrs->ip6e_hbh = mopt;
1176 	} else {
1177 		struct ip6_hbh *hbh;
1178 
1179 		mopt = exthdrs->ip6e_hbh;
1180 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1181 			/*
1182 			 * XXX assumption:
1183 			 * - exthdrs->ip6e_hbh is not referenced from places
1184 			 *   other than exthdrs.
1185 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1186 			 */
1187 			int oldoptlen = mopt->m_len;
1188 			struct mbuf *n;
1189 
1190 			/*
1191 			 * XXX: give up if the whole (new) hbh header does
1192 			 * not fit even in an mbuf cluster.
1193 			 */
1194 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1195 				return (ENOBUFS);
1196 
1197 			/*
1198 			 * As a consequence, we must always prepare a cluster
1199 			 * at this point.
1200 			 */
1201 			n = m_getcl(MB_DONTWAIT, MT_DATA, 0);
1202 			if (!n)
1203 				return (ENOBUFS);
1204 			n->m_len = oldoptlen + JUMBOOPTLEN;
1205 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t), oldoptlen);
1206 			optbuf = mtod(n, caddr_t) + oldoptlen;
1207 			m_freem(mopt);
1208 			mopt = exthdrs->ip6e_hbh = n;
1209 		} else {
1210 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1211 			mopt->m_len += JUMBOOPTLEN;
1212 		}
1213 		optbuf[0] = IP6OPT_PADN;
1214 		optbuf[1] = 1;
1215 
1216 		/*
1217 		 * Adjust the header length according to the pad and
1218 		 * the jumbo payload option.
1219 		 */
1220 		hbh = mtod(mopt, struct ip6_hbh *);
1221 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1222 	}
1223 
1224 	/* fill in the option. */
1225 	optbuf[2] = IP6OPT_JUMBO;
1226 	optbuf[3] = 4;
1227 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1228 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1229 
1230 	/* finally, adjust the packet header length */
1231 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1232 
1233 	return (0);
1234 #undef JUMBOOPTLEN
1235 }
1236 
1237 /*
1238  * Insert fragment header and copy unfragmentable header portions.
1239  */
1240 static int
1241 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1242 		  struct ip6_frag **frghdrp)
1243 {
1244 	struct mbuf *n, *mlast;
1245 
1246 	if (hlen > sizeof(struct ip6_hdr)) {
1247 		n = m_copym(m0, sizeof(struct ip6_hdr),
1248 			    hlen - sizeof(struct ip6_hdr), MB_DONTWAIT);
1249 		if (n == NULL)
1250 			return (ENOBUFS);
1251 		m->m_next = n;
1252 	} else
1253 		n = m;
1254 
1255 	/* Search for the last mbuf of unfragmentable part. */
1256 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1257 		;
1258 
1259 	if (!(mlast->m_flags & M_EXT) &&
1260 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1261 		/* use the trailing space of the last mbuf for the fragment hdr */
1262 		*frghdrp =
1263 			(struct ip6_frag *)(mtod(mlast, caddr_t) + mlast->m_len);
1264 		mlast->m_len += sizeof(struct ip6_frag);
1265 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1266 	} else {
1267 		/* allocate a new mbuf for the fragment header */
1268 		struct mbuf *mfrg;
1269 
1270 		MGET(mfrg, MB_DONTWAIT, MT_DATA);
1271 		if (mfrg == NULL)
1272 			return (ENOBUFS);
1273 		mfrg->m_len = sizeof(struct ip6_frag);
1274 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1275 		mlast->m_next = mfrg;
1276 	}
1277 
1278 	return (0);
1279 }
1280 
1281 static int
1282 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1283     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1284     int *alwaysfragp)
1285 {
1286 	u_int32_t mtu = 0;
1287 	int alwaysfrag = 0;
1288 	int error = 0;
1289 
1290 	if (ro_pmtu != ro) {
1291 		/* The first hop and the final destination may differ. */
1292 		struct sockaddr_in6 *sa6_dst =
1293 		    (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1294 		if (ro_pmtu->ro_rt &&
1295 		    ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1296 		     !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1297 			RTFREE(ro_pmtu->ro_rt);
1298 			ro_pmtu->ro_rt = NULL;
1299 		}
1300 		if (ro_pmtu->ro_rt == NULL) {
1301 			bzero(sa6_dst, sizeof(*sa6_dst));
1302 			sa6_dst->sin6_family = AF_INET6;
1303 			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1304 			sa6_dst->sin6_addr = *dst;
1305 
1306 			rtalloc((struct route *)ro_pmtu);
1307 		}
1308 	}
1309 	if (ro_pmtu->ro_rt) {
1310 		u_int32_t ifmtu;
1311 		struct in_conninfo inc;
1312 
1313 		bzero(&inc, sizeof(inc));
1314 		inc.inc_flags = 1; /* IPv6 */
1315 		inc.inc6_faddr = *dst;
1316 
1317 		if (ifp == NULL)
1318 			ifp = ro_pmtu->ro_rt->rt_ifp;
1319 		ifmtu = IN6_LINKMTU(ifp);
1320 		mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1321 		if (mtu == 0)
1322 			mtu = ifmtu;
1323 		else if (mtu < IPV6_MMTU) {
1324 			/*
1325 			 * RFC2460 section 5, last paragraph:
1326 			 * if we record ICMPv6 too big message with
1327 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1328 			 * or smaller, with framgent header attached.
1329 			 * (fragment header is needed regardless from the
1330 			 * packet size, for translators to identify packets)
1331 			 */
1332 			alwaysfrag = 1;
1333 			mtu = IPV6_MMTU;
1334 		} else if (mtu > ifmtu) {
1335 			/*
1336 			 * The MTU on the route is larger than the MTU on
1337 			 * the interface!  This shouldn't happen, unless the
1338 			 * MTU of the interface has been changed after the
1339 			 * interface was brought up.  Change the MTU in the
1340 			 * route to match the interface MTU (as long as the
1341 			 * field isn't locked).
1342 			 */
1343 			mtu = ifmtu;
1344 			ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1345 		}
1346 	} else if (ifp) {
1347 		mtu = IN6_LINKMTU(ifp);
1348 	} else
1349 		error = EHOSTUNREACH; /* XXX */
1350 
1351 	*mtup = mtu;
1352 	if (alwaysfragp)
1353 		*alwaysfragp = alwaysfrag;
1354 	return (error);
1355 }
1356 
1357 /*
1358  * IP6 socket option processing.
1359  */
1360 void
1361 ip6_ctloutput_dispatch(netmsg_t msg)
1362 {
1363 	int error;
1364 
1365 	error = ip6_ctloutput(msg->ctloutput.base.nm_so,
1366 			      msg->ctloutput.nm_sopt);
1367 	lwkt_replymsg(&msg->ctloutput.base.lmsg, error);
1368 }
1369 
1370 int
1371 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1372 {
1373 	int optdatalen,uproto;
1374 	int privileged;
1375 	struct inpcb *in6p = so->so_pcb;
1376 	void *optdata;
1377 	int error, optval;
1378 	int level, op, optname;
1379 	int optlen;
1380 	struct thread *td;
1381 
1382 	if (sopt) {
1383 		level = sopt->sopt_level;
1384 		op = sopt->sopt_dir;
1385 		optname = sopt->sopt_name;
1386 		optlen = sopt->sopt_valsize;
1387 		td = sopt->sopt_td;
1388 	} else {
1389 		panic("ip6_ctloutput: arg soopt is NULL");
1390 		/* NOT REACHED */
1391 		td = NULL;
1392 	}
1393 	error = optval = 0;
1394 
1395 	uproto = (int)so->so_proto->pr_protocol;
1396 	privileged = (td == NULL || priv_check(td, PRIV_ROOT)) ? 0 : 1;
1397 
1398 	if (level == IPPROTO_IPV6) {
1399 		switch (op) {
1400 
1401 		case SOPT_SET:
1402 			switch (optname) {
1403 			case IPV6_2292PKTOPTIONS:
1404 #ifdef IPV6_PKTOPTIONS
1405 			case IPV6_PKTOPTIONS:
1406 #endif
1407 			{
1408 				struct mbuf *m;
1409 
1410 				error = soopt_getm(sopt, &m); /* XXX */
1411 				if (error != 0)
1412 					break;
1413 				soopt_to_mbuf(sopt, m); /* XXX */
1414 				error = ip6_pcbopts(&in6p->in6p_outputopts,
1415 						    m, so, sopt);
1416 				m_freem(m); /* XXX */
1417 				break;
1418 			}
1419 
1420 			/*
1421 			 * Use of some Hop-by-Hop options or some
1422 			 * Destination options, might require special
1423 			 * privilege.  That is, normal applications
1424 			 * (without special privilege) might be forbidden
1425 			 * from setting certain options in outgoing packets,
1426 			 * and might never see certain options in received
1427 			 * packets. [RFC 2292 Section 6]
1428 			 * KAME specific note:
1429 			 *  KAME prevents non-privileged users from sending or
1430 			 *  receiving ANY hbh/dst options in order to avoid
1431 			 *  overhead of parsing options in the kernel.
1432 			 */
1433 			case IPV6_RECVHOPOPTS:
1434 			case IPV6_RECVDSTOPTS:
1435 			case IPV6_RECVRTHDRDSTOPTS:
1436 				if (!privileged)
1437 					return (EPERM);
1438 			case IPV6_RECVPKTINFO:
1439 			case IPV6_RECVHOPLIMIT:
1440 			case IPV6_RECVRTHDR:
1441 			case IPV6_RECVPATHMTU:
1442 			case IPV6_RECVTCLASS:
1443 			case IPV6_AUTOFLOWLABEL:
1444 			case IPV6_HOPLIMIT:
1445 			/* FALLTHROUGH */
1446 			case IPV6_UNICAST_HOPS:
1447 			case IPV6_FAITH:
1448 
1449 			case IPV6_V6ONLY:
1450 				if (optlen != sizeof(int)) {
1451 					error = EINVAL;
1452 					break;
1453 				}
1454 				error = soopt_to_kbuf(sopt, &optval,
1455 					sizeof optval, sizeof optval);
1456 				if (error)
1457 					break;
1458 				switch (optname) {
1459 
1460 				case IPV6_UNICAST_HOPS:
1461 					if (optval < -1 || optval >= 256)
1462 						error = EINVAL;
1463 					else {
1464 						/* -1 = kernel default */
1465 						in6p->in6p_hops = optval;
1466 
1467 						if ((in6p->in6p_vflag &
1468 						     INP_IPV4) != 0)
1469 							in6p->inp_ip_ttl = optval;
1470 					}
1471 					break;
1472 #define OPTSET(bit) \
1473 do { \
1474 	if (optval) \
1475 		in6p->in6p_flags |= (bit); \
1476 	else \
1477 		in6p->in6p_flags &= ~(bit); \
1478 } while (0)
1479 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
1480 /*
1481  * Although changed to RFC3542, It's better to also support RFC2292 API
1482  */
1483 #define OPTSET2292(bit) \
1484 do { \
1485 	in6p->in6p_flags |= IN6P_RFC2292; \
1486 	if (optval) \
1487 		in6p->in6p_flags |= (bit); \
1488 	else \
1489 		in6p->in6p_flags &= ~(bit); \
1490 } while (/*CONSTCOND*/ 0)
1491 
1492 				case IPV6_RECVPKTINFO:
1493 					/* cannot mix with RFC2292 */
1494 					if (OPTBIT(IN6P_RFC2292)) {
1495 						error = EINVAL;
1496 						break;
1497 					}
1498 					OPTSET(IN6P_PKTINFO);
1499 					break;
1500 
1501 				case IPV6_HOPLIMIT:
1502 				{
1503 					struct ip6_pktopts **optp;
1504 
1505 					/* cannot mix with RFC2292 */
1506 					if (OPTBIT(IN6P_RFC2292)) {
1507 						error = EINVAL;
1508 						break;
1509 					}
1510 					optp = &in6p->in6p_outputopts;
1511 					error = ip6_pcbopt(IPV6_HOPLIMIT,
1512 					    (u_char *)&optval, sizeof(optval),
1513 					    optp, uproto);
1514 					break;
1515 				}
1516 
1517 				case IPV6_RECVHOPLIMIT:
1518 					/* cannot mix with RFC2292 */
1519 					if (OPTBIT(IN6P_RFC2292)) {
1520 						error = EINVAL;
1521 						break;
1522 					}
1523 					OPTSET(IN6P_HOPLIMIT);
1524 					break;
1525 
1526 				case IPV6_RECVHOPOPTS:
1527 					/* cannot mix with RFC2292 */
1528 					if (OPTBIT(IN6P_RFC2292)) {
1529 						error = EINVAL;
1530 						break;
1531 					}
1532 					OPTSET(IN6P_HOPOPTS);
1533 					break;
1534 
1535 				case IPV6_RECVDSTOPTS:
1536 					/* cannot mix with RFC2292 */
1537 					if (OPTBIT(IN6P_RFC2292)) {
1538 						error = EINVAL;
1539 						break;
1540 					}
1541 					OPTSET(IN6P_DSTOPTS);
1542 					break;
1543 
1544 				case IPV6_RECVRTHDRDSTOPTS:
1545 					/* cannot mix with RFC2292 */
1546 					if (OPTBIT(IN6P_RFC2292)) {
1547 						error = EINVAL;
1548 						break;
1549 					}
1550 					OPTSET(IN6P_RTHDRDSTOPTS);
1551 					break;
1552 
1553 				case IPV6_RECVRTHDR:
1554 					/* cannot mix with RFC2292 */
1555 					if (OPTBIT(IN6P_RFC2292)) {
1556 						error = EINVAL;
1557 						break;
1558 					}
1559 					OPTSET(IN6P_RTHDR);
1560 					break;
1561 
1562 				case IPV6_RECVPATHMTU:
1563 					/*
1564 					 * We ignore this option for TCP
1565 					 * sockets.
1566 					 * (RFC3542 leaves this case
1567 					 * unspecified.)
1568 					 */
1569 					if (uproto != IPPROTO_TCP)
1570 						OPTSET(IN6P_MTU);
1571 					break;
1572 
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 
1582 				case IPV6_AUTOFLOWLABEL:
1583 					OPTSET(IN6P_AUTOFLOWLABEL);
1584 					break;
1585 
1586 				case IPV6_FAITH:
1587 					OPTSET(IN6P_FAITH);
1588 					break;
1589 
1590 				case IPV6_V6ONLY:
1591 					/*
1592 					 * make setsockopt(IPV6_V6ONLY)
1593 					 * available only prior to bind(2).
1594 					 */
1595 					if (in6p->in6p_lport ||
1596 					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr))
1597 					{
1598 						error = EINVAL;
1599 						break;
1600 					}
1601 					OPTSET(IN6P_IPV6_V6ONLY);
1602 					if (optval)
1603 						in6p->in6p_vflag &= ~INP_IPV4;
1604 					else
1605 						in6p->in6p_vflag |= INP_IPV4;
1606 					break;
1607 				}
1608 				break;
1609 
1610 			case IPV6_TCLASS:
1611 			case IPV6_DONTFRAG:
1612 			case IPV6_USE_MIN_MTU:
1613 			case IPV6_PREFER_TEMPADDR:
1614 				if (optlen != sizeof(optval)) {
1615 					error = EINVAL;
1616 					break;
1617 				}
1618 				error = soopt_to_kbuf(sopt, &optval,
1619 					sizeof optval, sizeof optval);
1620 				if (error)
1621 					break;
1622 				{
1623 					struct ip6_pktopts **optp;
1624 					optp = &in6p->in6p_outputopts;
1625 					error = ip6_pcbopt(optname,
1626 					    (u_char *)&optval, sizeof(optval),
1627 					    optp, uproto);
1628 					break;
1629 				}
1630 
1631 			case IPV6_2292PKTINFO:
1632 			case IPV6_2292HOPLIMIT:
1633 			case IPV6_2292HOPOPTS:
1634 			case IPV6_2292DSTOPTS:
1635 			case IPV6_2292RTHDR:
1636 				/* RFC 2292 */
1637 				if (optlen != sizeof(int)) {
1638 					error = EINVAL;
1639 					break;
1640 				}
1641 				error = soopt_to_kbuf(sopt, &optval,
1642 					sizeof optval, sizeof optval);
1643 				if (error)
1644 					break;
1645 				switch (optname) {
1646 				case IPV6_2292PKTINFO:
1647 					OPTSET2292(IN6P_PKTINFO);
1648 					break;
1649 				case IPV6_2292HOPLIMIT:
1650 					OPTSET2292(IN6P_HOPLIMIT);
1651 					break;
1652 				case IPV6_2292HOPOPTS:
1653 					/*
1654 					 * Check super-user privilege.
1655 					 * See comments for IPV6_RECVHOPOPTS.
1656 					 */
1657 					if (!privileged)
1658 						return (EPERM);
1659 					OPTSET2292(IN6P_HOPOPTS);
1660 					break;
1661 				case IPV6_2292DSTOPTS:
1662 					if (!privileged)
1663 						return (EPERM);
1664 					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1665 					break;
1666 				case IPV6_2292RTHDR:
1667 					OPTSET2292(IN6P_RTHDR);
1668 					break;
1669 				}
1670 				break;
1671 
1672 			case IPV6_PKTINFO:
1673 			case IPV6_HOPOPTS:
1674 			case IPV6_RTHDR:
1675 			case IPV6_DSTOPTS:
1676 			case IPV6_RTHDRDSTOPTS:
1677 			case IPV6_NEXTHOP:
1678 			{
1679 				/*
1680 				 * New advanced API (RFC3542)
1681 				 */
1682 				u_char *optbuf;
1683 				u_char optbuf_storage[MCLBYTES];
1684 				int optlen;
1685 				struct ip6_pktopts **optp;
1686 
1687 				/* cannot mix with RFC2292 */
1688 				if (OPTBIT(IN6P_RFC2292)) {
1689 					error = EINVAL;
1690 					break;
1691 				}
1692 
1693 				/*
1694 				 * We only ensure valsize is not too large
1695 				 * here.  Further validation will be done
1696 				 * later.
1697 				 */
1698 				error = soopt_to_kbuf(sopt, optbuf_storage,
1699 				    sizeof(optbuf_storage), 0);
1700 				if (error)
1701 					break;
1702 				optlen = sopt->sopt_valsize;
1703 				optbuf = optbuf_storage;
1704 				optp = &in6p->in6p_outputopts;
1705 				error = ip6_pcbopt(optname, optbuf, optlen,
1706 				    optp, uproto);
1707 				break;
1708 			}
1709 #undef OPTSET
1710 
1711 			case IPV6_MULTICAST_IF:
1712 			case IPV6_MULTICAST_HOPS:
1713 			case IPV6_MULTICAST_LOOP:
1714 			case IPV6_JOIN_GROUP:
1715 			case IPV6_LEAVE_GROUP:
1716 			    {
1717 				struct mbuf *m;
1718 				if (sopt->sopt_valsize > MLEN) {
1719 					error = EMSGSIZE;
1720 					break;
1721 				}
1722 				/* XXX */
1723 				MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER);
1724 				if (m == NULL) {
1725 					error = ENOBUFS;
1726 					break;
1727 				}
1728 				m->m_len = sopt->sopt_valsize;
1729 				error = soopt_to_kbuf(sopt, mtod(m, char *),
1730 						    m->m_len, m->m_len);
1731 				error =	ip6_setmoptions(sopt->sopt_name,
1732 							&in6p->in6p_moptions,
1733 							m);
1734 				m_free(m);
1735 			    }
1736 				break;
1737 
1738 			case IPV6_PORTRANGE:
1739 				error = soopt_to_kbuf(sopt, &optval,
1740 				    sizeof optval, sizeof optval);
1741 				if (error)
1742 					break;
1743 
1744 				switch (optval) {
1745 				case IPV6_PORTRANGE_DEFAULT:
1746 					in6p->in6p_flags &= ~(IN6P_LOWPORT);
1747 					in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1748 					break;
1749 
1750 				case IPV6_PORTRANGE_HIGH:
1751 					in6p->in6p_flags &= ~(IN6P_LOWPORT);
1752 					in6p->in6p_flags |= IN6P_HIGHPORT;
1753 					break;
1754 
1755 				case IPV6_PORTRANGE_LOW:
1756 					in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1757 					in6p->in6p_flags |= IN6P_LOWPORT;
1758 					break;
1759 
1760 				default:
1761 					error = EINVAL;
1762 					break;
1763 				}
1764 				break;
1765 
1766 #if defined(IPSEC) || defined(FAST_IPSEC)
1767 			case IPV6_IPSEC_POLICY:
1768 			    {
1769 				caddr_t req = NULL;
1770 				size_t len = 0;
1771 				struct mbuf *m;
1772 
1773 				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1774 					break;
1775 				soopt_to_mbuf(sopt, m);		/* XXX */
1776 				if (m) {
1777 					req = mtod(m, caddr_t);
1778 					len = m->m_len;
1779 				}
1780 				error = ipsec6_set_policy(in6p, optname, req,
1781 							  len, privileged);
1782 				m_freem(m);
1783 			    }
1784 				break;
1785 #endif /* KAME IPSEC */
1786 
1787 			case IPV6_FW_ADD:
1788 			case IPV6_FW_DEL:
1789 			case IPV6_FW_FLUSH:
1790 			case IPV6_FW_ZERO:
1791 			    {
1792 				struct mbuf *m;
1793 				struct mbuf **mp = &m;
1794 
1795 				if (ip6_fw_ctl_ptr == NULL)
1796 					return EINVAL;
1797 				/* XXX */
1798 				if ((error = soopt_getm(sopt, &m)) != 0)
1799 					break;
1800 				/* XXX */
1801 				soopt_to_mbuf(sopt, m);
1802 				error = (*ip6_fw_ctl_ptr)(optname, mp);
1803 				m = *mp;
1804 			    }
1805 				break;
1806 
1807 			default:
1808 				error = ENOPROTOOPT;
1809 				break;
1810 			}
1811 			break;
1812 
1813 		case SOPT_GET:
1814 			switch (optname) {
1815 			case IPV6_2292PKTOPTIONS:
1816 #ifdef IPV6_PKTOPTIONS
1817 			case IPV6_PKTOPTIONS:
1818 #endif
1819 				/*
1820 				 * RFC3542 (effectively) deprecated the
1821 				 * semantics of the 2292-style pktoptions.
1822 				 * Since it was not reliable in nature (i.e.,
1823 				 * applications had to expect the lack of some
1824 				 * information after all), it would make sense
1825 				 * to simplify this part by always returning
1826 				 * empty data.
1827 				 */
1828 				if (in6p->in6p_options) {
1829 					struct mbuf *m;
1830 					m = m_copym(in6p->in6p_options,
1831 					    0, M_COPYALL, MB_WAIT);
1832 					error = soopt_from_mbuf(sopt, m);
1833 					if (error == 0)
1834 						m_freem(m);
1835 				} else
1836 					sopt->sopt_valsize = 0;
1837 				break;
1838 
1839 			case IPV6_RECVHOPOPTS:
1840 			case IPV6_RECVDSTOPTS:
1841 			case IPV6_RECVRTHDRDSTOPTS:
1842 			case IPV6_UNICAST_HOPS:
1843 			case IPV6_RECVPKTINFO:
1844 			case IPV6_RECVHOPLIMIT:
1845 			case IPV6_RECVRTHDR:
1846 			case IPV6_RECVPATHMTU:
1847 			case IPV6_RECVTCLASS:
1848 			case IPV6_AUTOFLOWLABEL:
1849 			case IPV6_FAITH:
1850 			case IPV6_V6ONLY:
1851 			case IPV6_PORTRANGE:
1852 				switch (optname) {
1853 
1854 				case IPV6_RECVHOPOPTS:
1855 					optval = OPTBIT(IN6P_HOPOPTS);
1856 					break;
1857 
1858 				case IPV6_RECVDSTOPTS:
1859 					optval = OPTBIT(IN6P_DSTOPTS);
1860 					break;
1861 
1862 				case IPV6_RECVRTHDRDSTOPTS:
1863 					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1864 					break;
1865 
1866 				case IPV6_RECVPKTINFO:
1867 					optval = OPTBIT(IN6P_PKTINFO);
1868 					break;
1869 
1870 				case IPV6_RECVHOPLIMIT:
1871 					optval = OPTBIT(IN6P_HOPLIMIT);
1872 					break;
1873 
1874 				case IPV6_RECVRTHDR:
1875 					optval = OPTBIT(IN6P_RTHDR);
1876 					break;
1877 
1878 				case IPV6_RECVPATHMTU:
1879 					optval = OPTBIT(IN6P_MTU);
1880 					break;
1881 
1882 				case IPV6_RECVTCLASS:
1883 					optval = OPTBIT(IN6P_TCLASS);
1884 					break;
1885 
1886 				case IPV6_AUTOFLOWLABEL:
1887 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1888 					break;
1889 
1890 
1891 				case IPV6_UNICAST_HOPS:
1892 					optval = in6p->in6p_hops;
1893 					break;
1894 
1895 				case IPV6_FAITH:
1896 					optval = OPTBIT(IN6P_FAITH);
1897 					break;
1898 
1899 				case IPV6_V6ONLY:
1900 					optval = OPTBIT(IN6P_IPV6_V6ONLY);
1901 					break;
1902 
1903 				case IPV6_PORTRANGE:
1904 				    {
1905 					int flags;
1906 					flags = in6p->in6p_flags;
1907 					if (flags & IN6P_HIGHPORT)
1908 						optval = IPV6_PORTRANGE_HIGH;
1909 					else if (flags & IN6P_LOWPORT)
1910 						optval = IPV6_PORTRANGE_LOW;
1911 					else
1912 						optval = 0;
1913 					break;
1914 				    }
1915 				}
1916 				soopt_from_kbuf(sopt, &optval,
1917  					sizeof optval);
1918 				break;
1919 
1920 			case IPV6_PATHMTU:
1921 			{
1922 				u_long pmtu = 0;
1923 				struct ip6_mtuinfo mtuinfo;
1924 				struct route_in6 sro;
1925 
1926 				bzero(&sro, sizeof(sro));
1927 
1928 				if (!(so->so_state & SS_ISCONNECTED))
1929 					return (ENOTCONN);
1930 				/*
1931 				 * XXX: we dot not consider the case of source
1932 				 * routing, or optional information to specify
1933 				 * the outgoing interface.
1934 				 */
1935 				error = ip6_getpmtu(&sro, NULL, NULL,
1936 				    &in6p->in6p_faddr, &pmtu, NULL);
1937 				if (sro.ro_rt)
1938 					RTFREE(sro.ro_rt);
1939 				if (error)
1940 					break;
1941 				if (pmtu > IPV6_MAXPACKET)
1942 					pmtu = IPV6_MAXPACKET;
1943 
1944 				bzero(&mtuinfo, sizeof(mtuinfo));
1945 				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1946 				optdata = (void *)&mtuinfo;
1947 				optdatalen = sizeof(mtuinfo);
1948 				soopt_from_kbuf(sopt, optdata,
1949 				    optdatalen);
1950 				break;
1951 			}
1952 
1953 			case IPV6_2292PKTINFO:
1954 			case IPV6_2292HOPLIMIT:
1955 			case IPV6_2292HOPOPTS:
1956 			case IPV6_2292RTHDR:
1957 			case IPV6_2292DSTOPTS:
1958 				if (optname == IPV6_2292HOPOPTS ||
1959 				    optname == IPV6_2292DSTOPTS ||
1960 				    !privileged)
1961 					return (EPERM);
1962 				switch (optname) {
1963 				case IPV6_2292PKTINFO:
1964 					optval = OPTBIT(IN6P_PKTINFO);
1965 					break;
1966 				case IPV6_2292HOPLIMIT:
1967 					optval = OPTBIT(IN6P_HOPLIMIT);
1968 					break;
1969 				case IPV6_2292HOPOPTS:
1970 					if (!privileged)
1971 						return (EPERM);
1972 					optval = OPTBIT(IN6P_HOPOPTS);
1973 					break;
1974 				case IPV6_2292RTHDR:
1975 					optval = OPTBIT(IN6P_RTHDR);
1976 					break;
1977 				case IPV6_2292DSTOPTS:
1978 					if (!privileged)
1979 						return (EPERM);
1980 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1981 					break;
1982 				}
1983 				soopt_from_kbuf(sopt, &optval,
1984  					sizeof optval);
1985 				break;
1986 
1987 			case IPV6_PKTINFO:
1988 			case IPV6_HOPOPTS:
1989 			case IPV6_RTHDR:
1990 			case IPV6_DSTOPTS:
1991 			case IPV6_RTHDRDSTOPTS:
1992 			case IPV6_NEXTHOP:
1993 			case IPV6_TCLASS:
1994 			case IPV6_DONTFRAG:
1995 			case IPV6_USE_MIN_MTU:
1996 			case IPV6_PREFER_TEMPADDR:
1997 				error = ip6_getpcbopt(in6p->in6p_outputopts,
1998 				    optname, sopt);
1999 				break;
2000 
2001 			case IPV6_MULTICAST_IF:
2002 			case IPV6_MULTICAST_HOPS:
2003 			case IPV6_MULTICAST_LOOP:
2004 			case IPV6_JOIN_GROUP:
2005 			case IPV6_LEAVE_GROUP:
2006 			    {
2007 				struct mbuf *m;
2008 				error = ip6_getmoptions(sopt->sopt_name,
2009 						in6p->in6p_moptions, &m);
2010 				if (error == 0)
2011 					soopt_from_kbuf(sopt,
2012  						mtod(m, char *), m->m_len);
2013 				m_freem(m);
2014 			    }
2015 				break;
2016 
2017 #if defined(IPSEC) || defined(FAST_IPSEC)
2018 			case IPV6_IPSEC_POLICY:
2019 			  {
2020 				caddr_t req = NULL;
2021 				size_t len = 0;
2022 				struct mbuf *m = NULL;
2023 				struct mbuf **mp = &m;
2024 
2025 				error = soopt_getm(sopt, &m); /* XXX */
2026 				if (error != 0)
2027 					break;
2028 				soopt_to_mbuf(sopt, m); /* XXX */
2029 				if (m) {
2030 					req = mtod(m, caddr_t);
2031 					len = m->m_len;
2032 				}
2033 				error = ipsec6_get_policy(in6p, req, len, mp);
2034 				if (error == 0)
2035 					error = soopt_from_mbuf(sopt, m); /*XXX*/
2036 				if (error == 0 && m != NULL)
2037 					m_freem(m);
2038 				break;
2039 			  }
2040 #endif /* KAME IPSEC */
2041 
2042 			case IPV6_FW_GET:
2043 			  {
2044 				struct mbuf *m;
2045 				struct mbuf **mp = &m;
2046 
2047 				if (ip6_fw_ctl_ptr == NULL)
2048 				{
2049 					return EINVAL;
2050 				}
2051 				error = (*ip6_fw_ctl_ptr)(optname, mp);
2052 				if (error == 0)
2053 					error = soopt_from_mbuf(sopt, m); /* XXX */
2054 				if (error == 0 && m != NULL)
2055 					m_freem(m);
2056 			  }
2057 				break;
2058 
2059 			default:
2060 				error = ENOPROTOOPT;
2061 				break;
2062 			}
2063 			break;
2064 		}
2065 	} else {
2066 		error = EINVAL;
2067 	}
2068 	return (error);
2069 }
2070 
2071 int
2072 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2073 {
2074 	int error = 0, optval, optlen;
2075 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2076 	struct in6pcb *in6p = sotoin6pcb(so);
2077 	int level, op, optname;
2078 
2079 	if (sopt) {
2080 		level = sopt->sopt_level;
2081 		op = sopt->sopt_dir;
2082 		optname = sopt->sopt_name;
2083 		optlen = sopt->sopt_valsize;
2084 	} else
2085 		panic("ip6_raw_ctloutput: arg soopt is NULL");
2086 
2087 	if (level != IPPROTO_IPV6) {
2088 		return (EINVAL);
2089 	}
2090 
2091 	switch (optname) {
2092 	case IPV6_CHECKSUM:
2093 		/*
2094 		 * For ICMPv6 sockets, no modification allowed for checksum
2095 		 * offset, permit "no change" values to help existing apps.
2096 		 *
2097 		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2098 		 * for an ICMPv6 socket will fail."
2099 		 * The current behavior does not meet RFC3542.
2100 		 */
2101 		switch (op) {
2102 		case SOPT_SET:
2103 			if (optlen != sizeof(int)) {
2104 				error = EINVAL;
2105 				break;
2106 			}
2107 			error = soopt_to_kbuf(sopt, &optval,
2108 				    sizeof optval, sizeof optval);
2109 			if (error)
2110 				break;
2111 			if ((optval % 2) != 0) {
2112 				/* the API assumes even offset values */
2113 				error = EINVAL;
2114 			} else if (so->so_proto->pr_protocol ==
2115 			    IPPROTO_ICMPV6) {
2116 				if (optval != icmp6off)
2117 					error = EINVAL;
2118 			} else
2119 				in6p->in6p_cksum = optval;
2120 			break;
2121 
2122 		case SOPT_GET:
2123 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2124 				optval = icmp6off;
2125 			else
2126 				optval = in6p->in6p_cksum;
2127 
2128 			soopt_from_kbuf(sopt, &optval, sizeof(optval));
2129 			break;
2130 
2131 		default:
2132 			error = EINVAL;
2133 			break;
2134 		}
2135 		break;
2136 
2137 	default:
2138 		error = ENOPROTOOPT;
2139 		break;
2140 	}
2141 
2142 	return (error);
2143 }
2144 
2145 /*
2146  * Set up IP6 options in pcb for insertion in output packets or
2147  * specifying behavior of outgoing packets.
2148  */
2149 static int
2150 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2151     struct socket *so, struct sockopt *sopt)
2152 {
2153 	int priv = 0;
2154 	struct ip6_pktopts *opt = *pktopt;
2155 	int error = 0;
2156 
2157 	/* turn off any old options. */
2158 	if (opt) {
2159 #ifdef DIAGNOSTIC
2160 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2161 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2162 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2163 			kprintf("ip6_pcbopts: all specified options are cleared.\n");
2164 #endif
2165 		ip6_clearpktopts(opt, -1);
2166 	} else
2167 		opt = kmalloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2168 	*pktopt = NULL;
2169 
2170 	if (!m || m->m_len == 0) {
2171 		/*
2172 		 * Only turning off any previous options, regardless of
2173 		 * whether the opt is just created or given.
2174 		 */
2175 		kfree(opt, M_IP6OPT);
2176 		return (0);
2177 	}
2178 
2179 	/*  set options specified by user. */
2180 	if ((error = ip6_setpktoptions(m, opt, NULL, so->so_proto->pr_protocol, priv)) != 0) {
2181 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2182 		kfree(opt, M_IP6OPT);
2183 		return (error);
2184 	}
2185 	*pktopt = opt;
2186 	return (0);
2187 }
2188 
2189 
2190 /*
2191  * Below three functions are introduced by merge to RFC3542
2192  */
2193 
2194 static int
2195 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2196 {
2197 	void *optdata = NULL;
2198 	int optdatalen = 0;
2199 	struct ip6_ext *ip6e;
2200 	int error = 0;
2201 	struct in6_pktinfo null_pktinfo;
2202 	int deftclass = 0, on;
2203 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2204 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2205 
2206 	switch (optname) {
2207 	case IPV6_PKTINFO:
2208 		if (pktopt && pktopt->ip6po_pktinfo)
2209 			optdata = (void *)pktopt->ip6po_pktinfo;
2210 		else {
2211 			/* XXX: we don't have to do this every time... */
2212 			bzero(&null_pktinfo, sizeof(null_pktinfo));
2213 			optdata = (void *)&null_pktinfo;
2214 		}
2215 		optdatalen = sizeof(struct in6_pktinfo);
2216 		break;
2217 	case IPV6_TCLASS:
2218 		if (pktopt && pktopt->ip6po_tclass >= 0)
2219 			optdata = (void *)&pktopt->ip6po_tclass;
2220 		else
2221 			optdata = (void *)&deftclass;
2222 		optdatalen = sizeof(int);
2223 		break;
2224 	case IPV6_HOPOPTS:
2225 		if (pktopt && pktopt->ip6po_hbh) {
2226 			optdata = (void *)pktopt->ip6po_hbh;
2227 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2228 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2229 		}
2230 		break;
2231 	case IPV6_RTHDR:
2232 		if (pktopt && pktopt->ip6po_rthdr) {
2233 			optdata = (void *)pktopt->ip6po_rthdr;
2234 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2235 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2236 		}
2237 		break;
2238 	case IPV6_RTHDRDSTOPTS:
2239 		if (pktopt && pktopt->ip6po_dest1) {
2240 			optdata = (void *)pktopt->ip6po_dest1;
2241 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2242 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2243 		}
2244 		break;
2245 	case IPV6_DSTOPTS:
2246 		if (pktopt && pktopt->ip6po_dest2) {
2247 			optdata = (void *)pktopt->ip6po_dest2;
2248 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2249 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2250 		}
2251 		break;
2252 	case IPV6_NEXTHOP:
2253 		if (pktopt && pktopt->ip6po_nexthop) {
2254 			optdata = (void *)pktopt->ip6po_nexthop;
2255 			optdatalen = pktopt->ip6po_nexthop->sa_len;
2256 		}
2257 		break;
2258 	case IPV6_USE_MIN_MTU:
2259 		if (pktopt)
2260 			optdata = (void *)&pktopt->ip6po_minmtu;
2261 		else
2262 			optdata = (void *)&defminmtu;
2263 		optdatalen = sizeof(int);
2264 		break;
2265 	case IPV6_DONTFRAG:
2266 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2267 			on = 1;
2268 		else
2269 			on = 0;
2270 		optdata = (void *)&on;
2271 		optdatalen = sizeof(on);
2272 		break;
2273 	case IPV6_PREFER_TEMPADDR:
2274 		if (pktopt)
2275 			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2276 		else
2277 			optdata = (void *)&defpreftemp;
2278 		optdatalen = sizeof(int);
2279 		break;
2280 	default:		/* should not happen */
2281 #ifdef DIAGNOSTIC
2282 		panic("ip6_getpcbopt: unexpected option");
2283 #endif
2284 		return (ENOPROTOOPT);
2285 	}
2286 
2287 	soopt_from_kbuf(sopt, optdata, optdatalen);
2288 
2289 	return (error);
2290 }
2291 
2292 /*
2293  * initialize ip6_pktopts.  beware that there are non-zero default values in
2294  * the struct.
2295  */
2296 
2297 static int
2298 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt, int uproto)
2299 {
2300 	struct ip6_pktopts *opt;
2301 	int priv =0;
2302 	if (*pktopt == NULL) {
2303 		*pktopt = kmalloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2304 		init_ip6pktopts(*pktopt);
2305 	}
2306 	opt = *pktopt;
2307 
2308 	return (ip6_setpktoption(optname, buf, len, opt, 1, 0, uproto, priv));
2309 }
2310 
2311 /*
2312  * initialize ip6_pktopts.  beware that there are non-zero default values in
2313  * the struct.
2314  */
2315 void
2316 init_ip6pktopts(struct ip6_pktopts *opt)
2317 {
2318 
2319 	bzero(opt, sizeof(*opt));
2320 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2321 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2322 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2323 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2324 }
2325 
2326 void
2327 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2328 {
2329 	if (pktopt == NULL)
2330 		return;
2331 
2332 	if (optname == -1 || optname == IPV6_PKTINFO) {
2333 		if (pktopt->ip6po_pktinfo)
2334 			kfree(pktopt->ip6po_pktinfo, M_IP6OPT);
2335 		pktopt->ip6po_pktinfo = NULL;
2336 	}
2337 	if (optname == -1 || optname == IPV6_HOPLIMIT)
2338 		pktopt->ip6po_hlim = -1;
2339 	if (optname == -1 || optname == IPV6_TCLASS)
2340 		pktopt->ip6po_tclass = -1;
2341 	if (optname == -1 || optname == IPV6_NEXTHOP) {
2342 		if (pktopt->ip6po_nextroute.ro_rt) {
2343 			RTFREE(pktopt->ip6po_nextroute.ro_rt);
2344 			pktopt->ip6po_nextroute.ro_rt = NULL;
2345 		}
2346 		if (pktopt->ip6po_nexthop)
2347 			kfree(pktopt->ip6po_nexthop, M_IP6OPT);
2348 		pktopt->ip6po_nexthop = NULL;
2349 	}
2350 	if (optname == -1 || optname == IPV6_HOPOPTS) {
2351 		if (pktopt->ip6po_hbh)
2352 			kfree(pktopt->ip6po_hbh, M_IP6OPT);
2353 		pktopt->ip6po_hbh = NULL;
2354 	}
2355 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2356 		if (pktopt->ip6po_dest1)
2357 			kfree(pktopt->ip6po_dest1, M_IP6OPT);
2358 		pktopt->ip6po_dest1 = NULL;
2359 	}
2360 	if (optname == -1 || optname == IPV6_RTHDR) {
2361 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2362 			kfree(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2363 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2364 		if (pktopt->ip6po_route.ro_rt) {
2365 			RTFREE(pktopt->ip6po_route.ro_rt);
2366 			pktopt->ip6po_route.ro_rt = NULL;
2367 		}
2368 	}
2369 	if (optname == -1 || optname == IPV6_DSTOPTS) {
2370 		if (pktopt->ip6po_dest2)
2371 			kfree(pktopt->ip6po_dest2, M_IP6OPT);
2372 		pktopt->ip6po_dest2 = NULL;
2373 	}
2374 }
2375 
2376 #define PKTOPT_EXTHDRCPY(type) \
2377 do {\
2378 	if (src->type) {\
2379 		int hlen =\
2380 			(((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2381 		dst->type = kmalloc(hlen, M_IP6OPT, canwait);\
2382 		if (dst->type == NULL)\
2383 			goto bad;\
2384 		bcopy(src->type, dst->type, hlen);\
2385 	}\
2386 } while (0)
2387 
2388 struct ip6_pktopts *
2389 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2390 {
2391 	struct ip6_pktopts *dst;
2392 
2393 	if (src == NULL) {
2394 		kprintf("ip6_clearpktopts: invalid argument\n");
2395 		return (NULL);
2396 	}
2397 
2398 	dst = kmalloc(sizeof(*dst), M_IP6OPT, canwait | M_ZERO);
2399 	if (dst == NULL)
2400 		return (NULL);
2401 
2402 	dst->ip6po_hlim = src->ip6po_hlim;
2403 	if (src->ip6po_pktinfo) {
2404 		dst->ip6po_pktinfo = kmalloc(sizeof(*dst->ip6po_pktinfo),
2405 					    M_IP6OPT, canwait);
2406 		if (dst->ip6po_pktinfo == NULL)
2407 			goto bad;
2408 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2409 	}
2410 	if (src->ip6po_nexthop) {
2411 		dst->ip6po_nexthop = kmalloc(src->ip6po_nexthop->sa_len,
2412 					    M_IP6OPT, canwait);
2413 		if (dst->ip6po_nexthop == NULL)
2414 			goto bad;
2415 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2416 		      src->ip6po_nexthop->sa_len);
2417 	}
2418 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2419 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2420 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2421 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2422 	return (dst);
2423 
2424 bad:
2425 	if (dst->ip6po_pktinfo) kfree(dst->ip6po_pktinfo, M_IP6OPT);
2426 	if (dst->ip6po_nexthop) kfree(dst->ip6po_nexthop, M_IP6OPT);
2427 	if (dst->ip6po_hbh) kfree(dst->ip6po_hbh, M_IP6OPT);
2428 	if (dst->ip6po_dest1) kfree(dst->ip6po_dest1, M_IP6OPT);
2429 	if (dst->ip6po_dest2) kfree(dst->ip6po_dest2, M_IP6OPT);
2430 	if (dst->ip6po_rthdr) kfree(dst->ip6po_rthdr, M_IP6OPT);
2431 	kfree(dst, M_IP6OPT);
2432 	return (NULL);
2433 }
2434 
2435 static int
2436 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2437 {
2438 	if (dst == NULL || src == NULL)  {
2439 #ifdef DIAGNOSTIC
2440 		kprintf("ip6_clearpktopts: invalid argument\n");
2441 #endif
2442 		return (EINVAL);
2443 	}
2444 
2445 	dst->ip6po_hlim = src->ip6po_hlim;
2446 	dst->ip6po_tclass = src->ip6po_tclass;
2447 	dst->ip6po_flags = src->ip6po_flags;
2448 	if (src->ip6po_pktinfo) {
2449 		dst->ip6po_pktinfo = kmalloc(sizeof(*dst->ip6po_pktinfo),
2450 		    M_IP6OPT, canwait);
2451 		if (dst->ip6po_pktinfo == NULL)
2452 			goto bad;
2453 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2454 	}
2455 	if (src->ip6po_nexthop) {
2456 		dst->ip6po_nexthop = kmalloc(src->ip6po_nexthop->sa_len,
2457 		    M_IP6OPT, canwait);
2458 		if (dst->ip6po_nexthop == NULL)
2459 			goto bad;
2460 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2461 		    src->ip6po_nexthop->sa_len);
2462 	}
2463 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2464 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2465 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2466 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2467 	return (0);
2468 
2469   bad:
2470 	ip6_clearpktopts(dst, -1);
2471 	return (ENOBUFS);
2472 }
2473 #undef PKTOPT_EXTHDRCPY
2474 
2475 void
2476 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2477 {
2478 	if (pktopt == NULL)
2479 		return;
2480 
2481 	ip6_clearpktopts(pktopt, -1);
2482 
2483 	kfree(pktopt, M_IP6OPT);
2484 }
2485 
2486 /*
2487  * Set the IP6 multicast options in response to user setsockopt().
2488  */
2489 static int
2490 ip6_setmoptions(int optname, struct ip6_moptions **im6op, struct mbuf *m)
2491 {
2492 	int error = 0;
2493 	u_int loop, ifindex;
2494 	struct ipv6_mreq *mreq;
2495 	struct ifnet *ifp;
2496 	struct ip6_moptions *im6o = *im6op;
2497 	struct route_in6 ro;
2498 	struct sockaddr_in6 *dst;
2499 	struct in6_multi_mship *imm;
2500 	struct thread *td = curthread;	/* XXX */
2501 
2502 	if (im6o == NULL) {
2503 		/*
2504 		 * No multicast option buffer attached to the pcb;
2505 		 * allocate one and initialize to default values.
2506 		 */
2507 		im6o = (struct ip6_moptions *)
2508 			kmalloc(sizeof(*im6o), M_IPMOPTS, M_WAITOK);
2509 
2510 		*im6op = im6o;
2511 		im6o->im6o_multicast_ifp = NULL;
2512 		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2513 		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
2514 		LIST_INIT(&im6o->im6o_memberships);
2515 	}
2516 
2517 	switch (optname) {
2518 
2519 	case IPV6_MULTICAST_IF:
2520 		/*
2521 		 * Select the interface for outgoing multicast packets.
2522 		 */
2523 		if (m == NULL || m->m_len != sizeof(u_int)) {
2524 			error = EINVAL;
2525 			break;
2526 		}
2527 		bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
2528 		if (ifindex < 0 || if_index < ifindex) {
2529 			error = ENXIO;	/* XXX EINVAL? */
2530 			break;
2531 		}
2532 		ifp = ifindex2ifnet[ifindex];
2533 		if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
2534 			error = EADDRNOTAVAIL;
2535 			break;
2536 		}
2537 		im6o->im6o_multicast_ifp = ifp;
2538 		break;
2539 
2540 	case IPV6_MULTICAST_HOPS:
2541 	    {
2542 		/*
2543 		 * Set the IP6 hoplimit for outgoing multicast packets.
2544 		 */
2545 		int optval;
2546 		if (m == NULL || m->m_len != sizeof(int)) {
2547 			error = EINVAL;
2548 			break;
2549 		}
2550 		bcopy(mtod(m, u_int *), &optval, sizeof(optval));
2551 		if (optval < -1 || optval >= 256)
2552 			error = EINVAL;
2553 		else if (optval == -1)
2554 			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2555 		else
2556 			im6o->im6o_multicast_hlim = optval;
2557 		break;
2558 	    }
2559 
2560 	case IPV6_MULTICAST_LOOP:
2561 		/*
2562 		 * Set the loopback flag for outgoing multicast packets.
2563 		 * Must be zero or one.
2564 		 */
2565 		if (m == NULL || m->m_len != sizeof(u_int)) {
2566 			error = EINVAL;
2567 			break;
2568 		}
2569 		bcopy(mtod(m, u_int *), &loop, sizeof(loop));
2570 		if (loop > 1) {
2571 			error = EINVAL;
2572 			break;
2573 		}
2574 		im6o->im6o_multicast_loop = loop;
2575 		break;
2576 
2577 	case IPV6_JOIN_GROUP:
2578 		/*
2579 		 * Add a multicast group membership.
2580 		 * Group must be a valid IP6 multicast address.
2581 		 */
2582 		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2583 			error = EINVAL;
2584 			break;
2585 		}
2586 		mreq = mtod(m, struct ipv6_mreq *);
2587 		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2588 			/*
2589 			 * We use the unspecified address to specify to accept
2590 			 * all multicast addresses. Only super user is allowed
2591 			 * to do this.
2592 			 */
2593 			if (priv_check(td, PRIV_ROOT))
2594 			{
2595 				error = EACCES;
2596 				break;
2597 			}
2598 		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2599 			error = EINVAL;
2600 			break;
2601 		}
2602 
2603 		/*
2604 		 * If the interface is specified, validate it.
2605 		 */
2606 		if (mreq->ipv6mr_interface < 0
2607 		 || if_index < mreq->ipv6mr_interface) {
2608 			error = ENXIO;	/* XXX EINVAL? */
2609 			break;
2610 		}
2611 		/*
2612 		 * If no interface was explicitly specified, choose an
2613 		 * appropriate one according to the given multicast address.
2614 		 */
2615 		if (mreq->ipv6mr_interface == 0) {
2616 			/*
2617 			 * If the multicast address is in node-local scope,
2618 			 * the interface should be a loopback interface.
2619 			 * Otherwise, look up the routing table for the
2620 			 * address, and choose the outgoing interface.
2621 			 *   XXX: is it a good approach?
2622 			 */
2623 			if (IN6_IS_ADDR_MC_NODELOCAL(&mreq->ipv6mr_multiaddr)) {
2624 				ifp = &loif[0];
2625 			} else {
2626 				ro.ro_rt = NULL;
2627 				dst = (struct sockaddr_in6 *)&ro.ro_dst;
2628 				bzero(dst, sizeof(*dst));
2629 				dst->sin6_len = sizeof(struct sockaddr_in6);
2630 				dst->sin6_family = AF_INET6;
2631 				dst->sin6_addr = mreq->ipv6mr_multiaddr;
2632 				rtalloc((struct route *)&ro);
2633 				if (ro.ro_rt == NULL) {
2634 					error = EADDRNOTAVAIL;
2635 					break;
2636 				}
2637 				ifp = ro.ro_rt->rt_ifp;
2638 				rtfree(ro.ro_rt);
2639 			}
2640 		} else
2641 			ifp = ifindex2ifnet[mreq->ipv6mr_interface];
2642 
2643 		/*
2644 		 * See if we found an interface, and confirm that it
2645 		 * supports multicast
2646 		 */
2647 		if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
2648 			error = EADDRNOTAVAIL;
2649 			break;
2650 		}
2651 		/*
2652 		 * Put interface index into the multicast address,
2653 		 * if the address has link-local scope.
2654 		 */
2655 		if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
2656 			mreq->ipv6mr_multiaddr.s6_addr16[1]
2657 				= htons(mreq->ipv6mr_interface);
2658 		}
2659 		/*
2660 		 * See if the membership already exists.
2661 		 */
2662 		for (imm = im6o->im6o_memberships.lh_first;
2663 		     imm != NULL; imm = imm->i6mm_chain.le_next)
2664 			if (imm->i6mm_maddr->in6m_ifp == ifp &&
2665 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2666 					       &mreq->ipv6mr_multiaddr))
2667 				break;
2668 		if (imm != NULL) {
2669 			error = EADDRINUSE;
2670 			break;
2671 		}
2672 		/*
2673 		 * Everything looks good; add a new record to the multicast
2674 		 * address list for the given interface.
2675 		 */
2676 		imm = kmalloc(sizeof(*imm), M_IPMADDR, M_WAITOK);
2677 		if ((imm->i6mm_maddr =
2678 		     in6_addmulti(&mreq->ipv6mr_multiaddr, ifp, &error)) == NULL) {
2679 			kfree(imm, M_IPMADDR);
2680 			break;
2681 		}
2682 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
2683 		break;
2684 
2685 	case IPV6_LEAVE_GROUP:
2686 		/*
2687 		 * Drop a multicast group membership.
2688 		 * Group must be a valid IP6 multicast address.
2689 		 */
2690 		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2691 			error = EINVAL;
2692 			break;
2693 		}
2694 		mreq = mtod(m, struct ipv6_mreq *);
2695 		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2696 			if (priv_check(td, PRIV_ROOT)) {
2697 				error = EACCES;
2698 				break;
2699 			}
2700 		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2701 			error = EINVAL;
2702 			break;
2703 		}
2704 		/*
2705 		 * If an interface address was specified, get a pointer
2706 		 * to its ifnet structure.
2707 		 */
2708 		if (mreq->ipv6mr_interface < 0
2709 		 || if_index < mreq->ipv6mr_interface) {
2710 			error = ENXIO;	/* XXX EINVAL? */
2711 			break;
2712 		}
2713 		ifp = ifindex2ifnet[mreq->ipv6mr_interface];
2714 		/*
2715 		 * Put interface index into the multicast address,
2716 		 * if the address has link-local scope.
2717 		 */
2718 		if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
2719 			mreq->ipv6mr_multiaddr.s6_addr16[1]
2720 				= htons(mreq->ipv6mr_interface);
2721 		}
2722 		/*
2723 		 * Find the membership in the membership list.
2724 		 */
2725 		for (imm = im6o->im6o_memberships.lh_first;
2726 		     imm != NULL; imm = imm->i6mm_chain.le_next) {
2727 			if ((ifp == NULL ||
2728 			     imm->i6mm_maddr->in6m_ifp == ifp) &&
2729 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2730 					       &mreq->ipv6mr_multiaddr))
2731 				break;
2732 		}
2733 		if (imm == NULL) {
2734 			/* Unable to resolve interface */
2735 			error = EADDRNOTAVAIL;
2736 			break;
2737 		}
2738 		/*
2739 		 * Give up the multicast address record to which the
2740 		 * membership points.
2741 		 */
2742 		LIST_REMOVE(imm, i6mm_chain);
2743 		in6_delmulti(imm->i6mm_maddr);
2744 		kfree(imm, M_IPMADDR);
2745 		break;
2746 
2747 	default:
2748 		error = EOPNOTSUPP;
2749 		break;
2750 	}
2751 
2752 	/*
2753 	 * If all options have default values, no need to keep the mbuf.
2754 	 */
2755 	if (im6o->im6o_multicast_ifp == NULL &&
2756 	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
2757 	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
2758 	    im6o->im6o_memberships.lh_first == NULL) {
2759 		kfree(*im6op, M_IPMOPTS);
2760 		*im6op = NULL;
2761 	}
2762 
2763 	return (error);
2764 }
2765 
2766 /*
2767  * Return the IP6 multicast options in response to user getsockopt().
2768  */
2769 static int
2770 ip6_getmoptions(int optname, struct ip6_moptions *im6o, struct mbuf **mp)
2771 {
2772 	u_int *hlim, *loop, *ifindex;
2773 
2774 	*mp = m_get(MB_WAIT, MT_HEADER);		/* XXX */
2775 
2776 	switch (optname) {
2777 
2778 	case IPV6_MULTICAST_IF:
2779 		ifindex = mtod(*mp, u_int *);
2780 		(*mp)->m_len = sizeof(u_int);
2781 		if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
2782 			*ifindex = 0;
2783 		else
2784 			*ifindex = im6o->im6o_multicast_ifp->if_index;
2785 		return (0);
2786 
2787 	case IPV6_MULTICAST_HOPS:
2788 		hlim = mtod(*mp, u_int *);
2789 		(*mp)->m_len = sizeof(u_int);
2790 		if (im6o == NULL)
2791 			*hlim = ip6_defmcasthlim;
2792 		else
2793 			*hlim = im6o->im6o_multicast_hlim;
2794 		return (0);
2795 
2796 	case IPV6_MULTICAST_LOOP:
2797 		loop = mtod(*mp, u_int *);
2798 		(*mp)->m_len = sizeof(u_int);
2799 		if (im6o == NULL)
2800 			*loop = ip6_defmcasthlim;
2801 		else
2802 			*loop = im6o->im6o_multicast_loop;
2803 		return (0);
2804 
2805 	default:
2806 		return (EOPNOTSUPP);
2807 	}
2808 }
2809 
2810 /*
2811  * Discard the IP6 multicast options.
2812  */
2813 void
2814 ip6_freemoptions(struct ip6_moptions *im6o)
2815 {
2816 	struct in6_multi_mship *imm;
2817 
2818 	if (im6o == NULL)
2819 		return;
2820 
2821 	while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
2822 		LIST_REMOVE(imm, i6mm_chain);
2823 		if (imm->i6mm_maddr)
2824 			in6_delmulti(imm->i6mm_maddr);
2825 		kfree(imm, M_IPMADDR);
2826 	}
2827 	kfree(im6o, M_IPMOPTS);
2828 }
2829 
2830 /*
2831  * Set a particular packet option, as a sticky option or an ancillary data
2832  * item.  "len" can be 0 only when it's a sticky option.
2833  * We have 4 cases of combination of "sticky" and "cmsg":
2834  * "sticky=0, cmsg=0": impossible
2835  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2836  * "sticky=1, cmsg=0": RFC3542 socket option
2837  * "sticky=1, cmsg=1": RFC2292 socket option
2838  */
2839 static int
2840 ip6_setpktoption(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2841      int sticky, int cmsg, int uproto, int priv)
2842 {
2843 	int minmtupolicy, preftemp;
2844 	//int error;
2845 
2846 	if (!sticky && !cmsg) {
2847 		kprintf("ip6_setpktoption: impossible case\n");
2848 		return (EINVAL);
2849 	}
2850 
2851 	/*
2852 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2853 	 * not be specified in the context of RFC3542.  Conversely,
2854 	 * RFC3542 types should not be specified in the context of RFC2292.
2855 	 */
2856 	if (!cmsg) {
2857 		switch (optname) {
2858 		case IPV6_2292PKTINFO:
2859 		case IPV6_2292HOPLIMIT:
2860 		case IPV6_2292NEXTHOP:
2861 		case IPV6_2292HOPOPTS:
2862 		case IPV6_2292DSTOPTS:
2863 		case IPV6_2292RTHDR:
2864 		case IPV6_2292PKTOPTIONS:
2865 			return (ENOPROTOOPT);
2866 		}
2867 	}
2868 	if (sticky && cmsg) {
2869 		switch (optname) {
2870 		case IPV6_PKTINFO:
2871 		case IPV6_HOPLIMIT:
2872 		case IPV6_NEXTHOP:
2873 		case IPV6_HOPOPTS:
2874 		case IPV6_DSTOPTS:
2875 		case IPV6_RTHDRDSTOPTS:
2876 		case IPV6_RTHDR:
2877 		case IPV6_USE_MIN_MTU:
2878 		case IPV6_DONTFRAG:
2879 		case IPV6_TCLASS:
2880 		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2881 			return (ENOPROTOOPT);
2882 		}
2883 	}
2884 
2885 	switch (optname) {
2886 	case IPV6_2292PKTINFO:
2887 	case IPV6_PKTINFO:
2888 	{
2889 		struct in6_pktinfo *pktinfo;
2890 		if (len != sizeof(struct in6_pktinfo))
2891 			return (EINVAL);
2892 		pktinfo = (struct in6_pktinfo *)buf;
2893 
2894 		/*
2895 		 * An application can clear any sticky IPV6_PKTINFO option by
2896 		 * doing a "regular" setsockopt with ipi6_addr being
2897 		 * in6addr_any and ipi6_ifindex being zero.
2898 		 * [RFC 3542, Section 6]
2899 		 */
2900 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2901 		    pktinfo->ipi6_ifindex == 0 &&
2902 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2903 			ip6_clearpktopts(opt, optname);
2904 			break;
2905 		}
2906 
2907 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2908 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2909 			return (EINVAL);
2910 		}
2911 
2912 		/* validate the interface index if specified. */
2913 		if (pktinfo->ipi6_ifindex > if_index ||
2914 		    pktinfo->ipi6_ifindex < 0) {
2915 			 return (ENXIO);
2916 		}
2917 		/*
2918 		 * Check if the requested source address is indeed a
2919 		 * unicast address assigned to the node, and can be
2920 		 * used as the packet's source address.
2921 		 */
2922 		if (opt->ip6po_pktinfo != NULL &&
2923 		    !IN6_IS_ADDR_UNSPECIFIED(&opt->ip6po_pktinfo->ipi6_addr)) {
2924 			struct in6_ifaddr *ia6;
2925 			struct sockaddr_in6 sin6;
2926 
2927 			bzero(&sin6, sizeof(sin6));
2928 			sin6.sin6_len = sizeof(sin6);
2929 			sin6.sin6_family = AF_INET6;
2930 			sin6.sin6_addr =
2931 			opt->ip6po_pktinfo->ipi6_addr;
2932 			ia6 = (struct in6_ifaddr *)ifa_ifwithaddr(sin6tosa(&sin6));
2933 			if (ia6 == NULL ||
2934 				(ia6->ia6_flags & (IN6_IFF_ANYCAST |
2935 					IN6_IFF_NOTREADY)) != 0)
2936 			return (EADDRNOTAVAIL);
2937 		}
2938 
2939 		/*
2940 		 * We store the address anyway, and let in6_selectsrc()
2941 		 * validate the specified address.  This is because ipi6_addr
2942 		 * may not have enough information about its scope zone, and
2943 		 * we may need additional information (such as outgoing
2944 		 * interface or the scope zone of a destination address) to
2945 		 * disambiguate the scope.
2946 		 * XXX: the delay of the validation may confuse the
2947 		 * application when it is used as a sticky option.
2948 		 */
2949 		if (opt->ip6po_pktinfo == NULL) {
2950 			opt->ip6po_pktinfo = kmalloc(sizeof(*pktinfo),
2951 			    M_IP6OPT, M_NOWAIT);
2952 			if (opt->ip6po_pktinfo == NULL)
2953 				return (ENOBUFS);
2954 		}
2955 		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2956 		break;
2957 	}
2958 
2959 	case IPV6_2292HOPLIMIT:
2960 	case IPV6_HOPLIMIT:
2961 	{
2962 		int *hlimp;
2963 
2964 		/*
2965 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2966 		 * to simplify the ordering among hoplimit options.
2967 		 */
2968 		if (optname == IPV6_HOPLIMIT && sticky)
2969 			return (ENOPROTOOPT);
2970 
2971 		if (len != sizeof(int))
2972 			return (EINVAL);
2973 		hlimp = (int *)buf;
2974 		if (*hlimp < -1 || *hlimp > 255)
2975 			return (EINVAL);
2976 
2977 		opt->ip6po_hlim = *hlimp;
2978 		break;
2979 	}
2980 
2981 	case IPV6_TCLASS:
2982 	{
2983 		int tclass;
2984 
2985 		if (len != sizeof(int))
2986 			return (EINVAL);
2987 		tclass = *(int *)buf;
2988 		if (tclass < -1 || tclass > 255)
2989 			return (EINVAL);
2990 
2991 		opt->ip6po_tclass = tclass;
2992 		break;
2993 	}
2994 
2995 	case IPV6_2292NEXTHOP:
2996 	case IPV6_NEXTHOP:
2997 		if (!priv)
2998 			return (EPERM);
2999 
3000 		if (len == 0) {	/* just remove the option */
3001 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
3002 			break;
3003 		}
3004 
3005 		/* check if cmsg_len is large enough for sa_len */
3006 		if (len < sizeof(struct sockaddr) || len < *buf)
3007 			return (EINVAL);
3008 
3009 		switch (((struct sockaddr *)buf)->sa_family) {
3010 		case AF_INET6:
3011 		{
3012 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
3013 			//int error;
3014 
3015 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
3016 				return (EINVAL);
3017 
3018 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
3019 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
3020 				return (EINVAL);
3021 			}
3022 			break;
3023 		}
3024 		case AF_LINK:	/* should eventually be supported */
3025 		default:
3026 			return (EAFNOSUPPORT);
3027 		}
3028 
3029 		/* turn off the previous option, then set the new option. */
3030 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
3031 		opt->ip6po_nexthop = kmalloc(*buf, M_IP6OPT, M_NOWAIT);
3032 		if (opt->ip6po_nexthop == NULL)
3033 			return (ENOBUFS);
3034 		bcopy(buf, opt->ip6po_nexthop, *buf);
3035 		break;
3036 
3037 	case IPV6_2292HOPOPTS:
3038 	case IPV6_HOPOPTS:
3039 	{
3040 		struct ip6_hbh *hbh;
3041 		int hbhlen;
3042 
3043 		/*
3044 		 * XXX: We don't allow a non-privileged user to set ANY HbH
3045 		 * options, since per-option restriction has too much
3046 		 * overhead.
3047 		 */
3048 		if (!priv)
3049 			return (EPERM);
3050 		if (len == 0) {
3051 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
3052 			break;	/* just remove the option */
3053 		}
3054 
3055 		/* message length validation */
3056 		if (len < sizeof(struct ip6_hbh))
3057 			return (EINVAL);
3058 		hbh = (struct ip6_hbh *)buf;
3059 		hbhlen = (hbh->ip6h_len + 1) << 3;
3060 		if (len != hbhlen)
3061 			return (EINVAL);
3062 
3063 		/* turn off the previous option, then set the new option. */
3064 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
3065 		opt->ip6po_hbh = kmalloc(hbhlen, M_IP6OPT, M_NOWAIT);
3066 		if (opt->ip6po_hbh == NULL)
3067 			return (ENOBUFS);
3068 		bcopy(hbh, opt->ip6po_hbh, hbhlen);
3069 
3070 		break;
3071 	}
3072 
3073 	case IPV6_2292DSTOPTS:
3074 	case IPV6_DSTOPTS:
3075 	case IPV6_RTHDRDSTOPTS:
3076 	{
3077 		struct ip6_dest *dest, **newdest = NULL;
3078 		int destlen;
3079 		if (!priv)
3080 			return (EPERM);
3081 
3082 		if (len == 0) {
3083 			ip6_clearpktopts(opt, optname);
3084 			break;	/* just remove the option */
3085 		}
3086 
3087 		/* message length validation */
3088 		if (len < sizeof(struct ip6_dest))
3089 			return (EINVAL);
3090 		dest = (struct ip6_dest *)buf;
3091 		destlen = (dest->ip6d_len + 1) << 3;
3092 		if (len != destlen)
3093 			return (EINVAL);
3094 
3095 		/*
3096 		 * Determine the position that the destination options header
3097 		 * should be inserted; before or after the routing header.
3098 		 */
3099 		switch (optname) {
3100 		case IPV6_2292DSTOPTS:
3101 			/*
3102 			 * The old advacned API is ambiguous on this point.
3103 			 * Our approach is to determine the position based
3104 			 * according to the existence of a routing header.
3105 			 * Note, however, that this depends on the order of the
3106 			 * extension headers in the ancillary data; the 1st
3107 			 * part of the destination options header must appear
3108 			 * before the routing header in the ancillary data,
3109 			 * too.
3110 			 * RFC3542 solved the ambiguity by introducing
3111 			 * separate ancillary data or option types.
3112 			 */
3113 			if (opt->ip6po_rthdr == NULL)
3114 				newdest = &opt->ip6po_dest1;
3115 			else
3116 				newdest = &opt->ip6po_dest2;
3117 			break;
3118 		case IPV6_RTHDRDSTOPTS:
3119 			newdest = &opt->ip6po_dest1;
3120 			break;
3121 		case IPV6_DSTOPTS:
3122 			newdest = &opt->ip6po_dest2;
3123 			break;
3124 		}
3125 
3126 		/* turn off the previous option, then set the new option. */
3127 		ip6_clearpktopts(opt, optname);
3128 		*newdest = kmalloc(destlen, M_IP6OPT, M_NOWAIT);
3129 		if (*newdest == NULL)
3130 			return (ENOBUFS);
3131 		bcopy(dest, *newdest, destlen);
3132 
3133 		break;
3134 	}
3135 
3136 	case IPV6_2292RTHDR:
3137 	case IPV6_RTHDR:
3138 	{
3139 		struct ip6_rthdr *rth;
3140 		int rthlen;
3141 
3142 		if (len == 0) {
3143 			ip6_clearpktopts(opt, IPV6_RTHDR);
3144 			break;	/* just remove the option */
3145 		}
3146 
3147 		/* message length validation */
3148 		if (len < sizeof(struct ip6_rthdr))
3149 			return (EINVAL);
3150 		rth = (struct ip6_rthdr *)buf;
3151 		rthlen = (rth->ip6r_len + 1) << 3;
3152 		if (len != rthlen)
3153 			return (EINVAL);
3154 
3155 		switch (rth->ip6r_type) {
3156 		default:
3157 			return (EINVAL);	/* not supported */
3158 		}
3159 
3160 		/* turn off the previous option */
3161 		ip6_clearpktopts(opt, IPV6_RTHDR);
3162 		opt->ip6po_rthdr = kmalloc(rthlen, M_IP6OPT, M_NOWAIT);
3163 		if (opt->ip6po_rthdr == NULL)
3164 			return (ENOBUFS);
3165 		bcopy(rth, opt->ip6po_rthdr, rthlen);
3166 
3167 		break;
3168 	}
3169 
3170 	case IPV6_USE_MIN_MTU:
3171 		if (len != sizeof(int))
3172 			return (EINVAL);
3173 		minmtupolicy = *(int *)buf;
3174 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3175 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
3176 		    minmtupolicy != IP6PO_MINMTU_ALL) {
3177 			return (EINVAL);
3178 		}
3179 		opt->ip6po_minmtu = minmtupolicy;
3180 		break;
3181 
3182 	case IPV6_DONTFRAG:
3183 		if (len != sizeof(int))
3184 			return (EINVAL);
3185 
3186 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3187 			/*
3188 			 * we ignore this option for TCP sockets.
3189 			 * (RFC3542 leaves this case unspecified.)
3190 			 */
3191 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3192 		} else
3193 			opt->ip6po_flags |= IP6PO_DONTFRAG;
3194 		break;
3195 
3196 	case IPV6_PREFER_TEMPADDR:
3197 		if (len != sizeof(int))
3198 			return (EINVAL);
3199 		preftemp = *(int *)buf;
3200 		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3201 		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3202 		    preftemp != IP6PO_TEMPADDR_PREFER) {
3203 			return (EINVAL);
3204 		}
3205 		opt->ip6po_prefer_tempaddr = preftemp;
3206 		break;
3207 
3208 	default:
3209 		return (ENOPROTOOPT);
3210 	} /* end of switch */
3211 
3212 	return (0);
3213 }
3214 
3215 
3216 /*
3217  * Set IPv6 outgoing packet options based on advanced API.
3218  */
3219 int
3220 ip6_setpktoptions(struct mbuf *control, struct ip6_pktopts *opt,
3221     struct ip6_pktopts *stickyopt, int uproto, int priv)
3222 {
3223 	struct cmsghdr *cm = NULL;
3224 
3225 	if (control == NULL || opt == NULL)
3226 		return (EINVAL);
3227 
3228 	init_ip6pktopts(opt);
3229 
3230 	/*
3231 	 * XXX: Currently, we assume all the optional information is stored
3232 	 * in a single mbuf.
3233 	 */
3234 	if (stickyopt) {
3235 		int error;
3236 
3237 		/*
3238 		 * If stickyopt is provided, make a local copy of the options
3239 		 * for this particular packet, then override them by ancillary
3240 		 * objects.
3241 		 * XXX: copypktopts() does not copy the cached route to a next
3242 		 * hop (if any).  This is not very good in terms of efficiency,
3243 		 * but we can allow this since this option should be rarely
3244 		 * used.
3245 		 */
3246 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
3247 			return (error);
3248 	}
3249 
3250 	/*
3251 	 * XXX: Currently, we assume all the optional information is stored
3252 	 * in a single mbuf.
3253 	 */
3254 	if (control->m_next)
3255 		return (EINVAL);
3256 
3257 	for (; control->m_len; control->m_data += CMSG_ALIGN(cm->cmsg_len),
3258 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
3259 		int error;
3260 
3261 		if (control->m_len < CMSG_LEN(0))
3262 			return (EINVAL);
3263 
3264 		cm = mtod(control, struct cmsghdr *);
3265 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
3266 			return (EINVAL);
3267 		if (cm->cmsg_level != IPPROTO_IPV6)
3268 			continue;
3269 
3270 		error = ip6_setpktoption(cm->cmsg_type, CMSG_DATA(cm),
3271 		    cm->cmsg_len - CMSG_LEN(0), opt, 0, 1, uproto, priv);
3272 		if (error)
3273 			return (error);
3274 	}
3275 
3276 	return (0);
3277 }
3278 
3279 /*
3280  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3281  * packet to the input queue of a specified interface.  Note that this
3282  * calls the output routine of the loopback "driver", but with an interface
3283  * pointer that might NOT be &loif -- easier than replicating that code here.
3284  */
3285 void
3286 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
3287 {
3288 	struct mbuf *copym;
3289 	struct ip6_hdr *ip6;
3290 
3291 	copym = m_copy(m, 0, M_COPYALL);
3292 	if (copym == NULL)
3293 		return;
3294 
3295 	/*
3296 	 * Make sure to deep-copy IPv6 header portion in case the data
3297 	 * is in an mbuf cluster, so that we can safely override the IPv6
3298 	 * header portion later.
3299 	 */
3300 	if ((copym->m_flags & M_EXT) != 0 ||
3301 	    copym->m_len < sizeof(struct ip6_hdr)) {
3302 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
3303 		if (copym == NULL)
3304 			return;
3305 	}
3306 
3307 #ifdef DIAGNOSTIC
3308 	if (copym->m_len < sizeof(*ip6)) {
3309 		m_freem(copym);
3310 		return;
3311 	}
3312 #endif
3313 
3314 	ip6 = mtod(copym, struct ip6_hdr *);
3315 	/*
3316 	 * clear embedded scope identifiers if necessary.
3317 	 * in6_clearscope will touch the addresses only when necessary.
3318 	 */
3319 	in6_clearscope(&ip6->ip6_src);
3320 	in6_clearscope(&ip6->ip6_dst);
3321 
3322 	if_simloop(ifp, copym, dst->sin6_family, 0);
3323 }
3324 
3325 /*
3326  * Separate the IPv6 header from the payload into its own mbuf.
3327  *
3328  * Returns the new mbuf chain or the original mbuf if no payload.
3329  * Returns NULL if can't allocate new mbuf for header.
3330  */
3331 static struct mbuf *
3332 ip6_splithdr(struct mbuf *m)
3333 {
3334 	struct mbuf *mh;
3335 
3336 	if (m->m_len <= sizeof(struct ip6_hdr))		/* no payload */
3337 		return (m);
3338 
3339 	MGETHDR(mh, MB_DONTWAIT, MT_HEADER);
3340 	if (mh == NULL)
3341 		return (NULL);
3342 	mh->m_len = sizeof(struct ip6_hdr);
3343 	M_MOVE_PKTHDR(mh, m);
3344 	MH_ALIGN(mh, sizeof(struct ip6_hdr));
3345 	bcopy(mtod(m, caddr_t), mtod(mh, caddr_t), sizeof(struct ip6_hdr));
3346 	m->m_data += sizeof(struct ip6_hdr);
3347 	m->m_len -= sizeof(struct ip6_hdr);
3348 	mh->m_next = m;
3349 	return (mh);
3350 }
3351 
3352 /*
3353  * Compute IPv6 extension header length.
3354  */
3355 int
3356 ip6_optlen(struct in6pcb *in6p)
3357 {
3358 	int len;
3359 
3360 	if (!in6p->in6p_outputopts)
3361 		return 0;
3362 
3363 	len = 0;
3364 #define elen(x) \
3365     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3366 
3367 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
3368 	if (in6p->in6p_outputopts->ip6po_rthdr)
3369 		/* dest1 is valid with rthdr only */
3370 		len += elen(in6p->in6p_outputopts->ip6po_dest1);
3371 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3372 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
3373 	return len;
3374 #undef elen
3375 }
3376