xref: /freebsd/sys/netinet6/ip6_output.c (revision 5abd6fdcfa8cd6bdce99672b3a421d9313870472)
1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
30  */
31 
32 /*-
33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 4. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
61  */
62 
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65 
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipfw.h"
69 #include "opt_ipsec.h"
70 #include "opt_sctp.h"
71 #include "opt_route.h"
72 
73 #include <sys/param.h>
74 #include <sys/kernel.h>
75 #include <sys/malloc.h>
76 #include <sys/mbuf.h>
77 #include <sys/errno.h>
78 #include <sys/priv.h>
79 #include <sys/proc.h>
80 #include <sys/protosw.h>
81 #include <sys/socket.h>
82 #include <sys/socketvar.h>
83 #include <sys/syslog.h>
84 #include <sys/ucred.h>
85 
86 #include <machine/in_cksum.h>
87 
88 #include <net/if.h>
89 #include <net/if_var.h>
90 #include <net/netisr.h>
91 #include <net/route.h>
92 #include <net/pfil.h>
93 #include <net/vnet.h>
94 
95 #include <netinet/in.h>
96 #include <netinet/in_var.h>
97 #include <netinet/ip_var.h>
98 #include <netinet6/in6_var.h>
99 #include <netinet/ip6.h>
100 #include <netinet/icmp6.h>
101 #include <netinet6/ip6_var.h>
102 #include <netinet/in_pcb.h>
103 #include <netinet/tcp_var.h>
104 #include <netinet6/nd6.h>
105 
106 #ifdef IPSEC
107 #include <netipsec/ipsec.h>
108 #include <netipsec/ipsec6.h>
109 #include <netipsec/key.h>
110 #include <netinet6/ip6_ipsec.h>
111 #endif /* IPSEC */
112 #ifdef SCTP
113 #include <netinet/sctp.h>
114 #include <netinet/sctp_crc32.h>
115 #endif
116 
117 #include <netinet6/ip6protosw.h>
118 #include <netinet6/scope6_var.h>
119 
120 #ifdef FLOWTABLE
121 #include <net/flowtable.h>
122 #endif
123 
124 extern int in6_mcast_loop;
125 
126 struct ip6_exthdrs {
127 	struct mbuf *ip6e_ip6;
128 	struct mbuf *ip6e_hbh;
129 	struct mbuf *ip6e_dest1;
130 	struct mbuf *ip6e_rthdr;
131 	struct mbuf *ip6e_dest2;
132 };
133 
134 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
135 			   struct ucred *, int);
136 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
137 	struct socket *, struct sockopt *);
138 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
139 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
140 	struct ucred *, int, int, int);
141 
142 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
143 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
144 	struct ip6_frag **);
145 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
146 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
147 static int ip6_getpmtu(struct route_in6 *, struct route_in6 *,
148 	struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
149 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
150 
151 
152 /*
153  * Make an extension header from option data.  hp is the source, and
154  * mp is the destination.
155  */
156 #define MAKE_EXTHDR(hp, mp)						\
157     do {								\
158 	if (hp) {							\
159 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
160 		error = ip6_copyexthdr((mp), (caddr_t)(hp),		\
161 		    ((eh)->ip6e_len + 1) << 3);				\
162 		if (error)						\
163 			goto freehdrs;					\
164 	}								\
165     } while (/*CONSTCOND*/ 0)
166 
167 /*
168  * Form a chain of extension headers.
169  * m is the extension header mbuf
170  * mp is the previous mbuf in the chain
171  * p is the next header
172  * i is the type of option.
173  */
174 #define MAKE_CHAIN(m, mp, p, i)\
175     do {\
176 	if (m) {\
177 		if (!hdrsplit) \
178 			panic("assumption failed: hdr not split"); \
179 		*mtod((m), u_char *) = *(p);\
180 		*(p) = (i);\
181 		p = mtod((m), u_char *);\
182 		(m)->m_next = (mp)->m_next;\
183 		(mp)->m_next = (m);\
184 		(mp) = (m);\
185 	}\
186     } while (/*CONSTCOND*/ 0)
187 
188 static void
189 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
190 {
191 	u_short csum;
192 
193 	csum = in_cksum_skip(m, offset + plen, offset);
194 	if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
195 		csum = 0xffff;
196 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
197 
198 	if (offset + sizeof(u_short) > m->m_len) {
199 		printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
200 		    "csum_flags=%b\n", __func__, m->m_len, plen, offset,
201 		    (int)m->m_pkthdr.csum_flags, CSUM_BITS);
202 		/*
203 		 * XXX this should not happen, but if it does, the correct
204 		 * behavior may be to insert the checksum in the appropriate
205 		 * next mbuf in the chain.
206 		 */
207 		return;
208 	}
209 	*(u_short *)(m->m_data + offset) = csum;
210 }
211 
212 /*
213  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
214  * header (with pri, len, nxt, hlim, src, dst).
215  * This function may modify ver and hlim only.
216  * The mbuf chain containing the packet will be freed.
217  * The mbuf opt, if present, will not be freed.
218  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
219  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
220  * then result of route lookup is stored in ro->ro_rt.
221  *
222  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
223  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
224  * which is rt_rmx.rmx_mtu.
225  *
226  * ifpp - XXX: just for statistics
227  */
228 int
229 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
230     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
231     struct ifnet **ifpp, struct inpcb *inp)
232 {
233 	struct ip6_hdr *ip6, *mhip6;
234 	struct ifnet *ifp, *origifp;
235 	struct mbuf *m = m0;
236 	struct mbuf *mprev = NULL;
237 	int hlen, tlen, len, off;
238 	struct route_in6 ip6route;
239 	struct rtentry *rt = NULL;
240 	struct sockaddr_in6 *dst, src_sa, dst_sa;
241 	struct in6_addr odst;
242 	int error = 0;
243 	struct in6_ifaddr *ia = NULL;
244 	u_long mtu;
245 	int alwaysfrag, dontfrag;
246 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
247 	struct ip6_exthdrs exthdrs;
248 	struct in6_addr finaldst, src0, dst0;
249 	u_int32_t zone;
250 	struct route_in6 *ro_pmtu = NULL;
251 	int hdrsplit = 0;
252 	int needipsec = 0;
253 	int sw_csum, tso;
254 #ifdef IPSEC
255 	struct ipsec_output_state state;
256 	struct ip6_rthdr *rh = NULL;
257 	int needipsectun = 0;
258 	int segleft_org = 0;
259 	struct secpolicy *sp = NULL;
260 #endif /* IPSEC */
261 	struct m_tag *fwd_tag = NULL;
262 
263 	ip6 = mtod(m, struct ip6_hdr *);
264 	if (ip6 == NULL) {
265 		printf ("ip6 is NULL");
266 		goto bad;
267 	}
268 
269 	if (inp != NULL)
270 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
271 
272 	finaldst = ip6->ip6_dst;
273 	bzero(&exthdrs, sizeof(exthdrs));
274 	if (opt) {
275 		/* Hop-by-Hop options header */
276 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
277 		/* Destination options header(1st part) */
278 		if (opt->ip6po_rthdr) {
279 			/*
280 			 * Destination options header(1st part)
281 			 * This only makes sense with a routing header.
282 			 * See Section 9.2 of RFC 3542.
283 			 * Disabling this part just for MIP6 convenience is
284 			 * a bad idea.  We need to think carefully about a
285 			 * way to make the advanced API coexist with MIP6
286 			 * options, which might automatically be inserted in
287 			 * the kernel.
288 			 */
289 			MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
290 		}
291 		/* Routing header */
292 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
293 		/* Destination options header(2nd part) */
294 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
295 	}
296 
297 #ifdef IPSEC
298 	/*
299 	 * IPSec checking which handles several cases.
300 	 * FAST IPSEC: We re-injected the packet.
301 	 */
302 	switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
303 	{
304 	case 1:                 /* Bad packet */
305 		goto freehdrs;
306 	case -1:                /* Do IPSec */
307 		needipsec = 1;
308 		/*
309 		 * Do delayed checksums now, as we may send before returning.
310 		 */
311 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
312 			plen = m->m_pkthdr.len - sizeof(*ip6);
313 			in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
314 			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
315 		}
316 #ifdef SCTP
317 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
318 			sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
319 			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
320 		}
321 #endif
322 	case 0:                 /* No IPSec */
323 	default:
324 		break;
325 	}
326 #endif /* IPSEC */
327 
328 	/*
329 	 * Calculate the total length of the extension header chain.
330 	 * Keep the length of the unfragmentable part for fragmentation.
331 	 */
332 	optlen = 0;
333 	if (exthdrs.ip6e_hbh)
334 		optlen += exthdrs.ip6e_hbh->m_len;
335 	if (exthdrs.ip6e_dest1)
336 		optlen += exthdrs.ip6e_dest1->m_len;
337 	if (exthdrs.ip6e_rthdr)
338 		optlen += exthdrs.ip6e_rthdr->m_len;
339 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
340 
341 	/* NOTE: we don't add AH/ESP length here. do that later. */
342 	if (exthdrs.ip6e_dest2)
343 		optlen += exthdrs.ip6e_dest2->m_len;
344 
345 	/*
346 	 * If we need IPsec, or there is at least one extension header,
347 	 * separate IP6 header from the payload.
348 	 */
349 	if ((needipsec || optlen) && !hdrsplit) {
350 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
351 			m = NULL;
352 			goto freehdrs;
353 		}
354 		m = exthdrs.ip6e_ip6;
355 		hdrsplit++;
356 	}
357 
358 	/* adjust pointer */
359 	ip6 = mtod(m, struct ip6_hdr *);
360 
361 	/* adjust mbuf packet header length */
362 	m->m_pkthdr.len += optlen;
363 	plen = m->m_pkthdr.len - sizeof(*ip6);
364 
365 	/* If this is a jumbo payload, insert a jumbo payload option. */
366 	if (plen > IPV6_MAXPACKET) {
367 		if (!hdrsplit) {
368 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
369 				m = NULL;
370 				goto freehdrs;
371 			}
372 			m = exthdrs.ip6e_ip6;
373 			hdrsplit++;
374 		}
375 		/* adjust pointer */
376 		ip6 = mtod(m, struct ip6_hdr *);
377 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
378 			goto freehdrs;
379 		ip6->ip6_plen = 0;
380 	} else
381 		ip6->ip6_plen = htons(plen);
382 
383 	/*
384 	 * Concatenate headers and fill in next header fields.
385 	 * Here we have, on "m"
386 	 *	IPv6 payload
387 	 * and we insert headers accordingly.  Finally, we should be getting:
388 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
389 	 *
390 	 * during the header composing process, "m" points to IPv6 header.
391 	 * "mprev" points to an extension header prior to esp.
392 	 */
393 	u_char *nexthdrp = &ip6->ip6_nxt;
394 	mprev = m;
395 
396 	/*
397 	 * we treat dest2 specially.  this makes IPsec processing
398 	 * much easier.  the goal here is to make mprev point the
399 	 * mbuf prior to dest2.
400 	 *
401 	 * result: IPv6 dest2 payload
402 	 * m and mprev will point to IPv6 header.
403 	 */
404 	if (exthdrs.ip6e_dest2) {
405 		if (!hdrsplit)
406 			panic("assumption failed: hdr not split");
407 		exthdrs.ip6e_dest2->m_next = m->m_next;
408 		m->m_next = exthdrs.ip6e_dest2;
409 		*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
410 		ip6->ip6_nxt = IPPROTO_DSTOPTS;
411 	}
412 
413 	/*
414 	 * result: IPv6 hbh dest1 rthdr dest2 payload
415 	 * m will point to IPv6 header.  mprev will point to the
416 	 * extension header prior to dest2 (rthdr in the above case).
417 	 */
418 	MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
419 	MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
420 		   IPPROTO_DSTOPTS);
421 	MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
422 		   IPPROTO_ROUTING);
423 
424 #ifdef IPSEC
425 	if (!needipsec)
426 		goto skip_ipsec2;
427 
428 	/*
429 	 * pointers after IPsec headers are not valid any more.
430 	 * other pointers need a great care too.
431 	 * (IPsec routines should not mangle mbufs prior to AH/ESP)
432 	 */
433 	exthdrs.ip6e_dest2 = NULL;
434 
435 	if (exthdrs.ip6e_rthdr) {
436 		rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
437 		segleft_org = rh->ip6r_segleft;
438 		rh->ip6r_segleft = 0;
439 	}
440 
441 	bzero(&state, sizeof(state));
442 	state.m = m;
443 	error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
444 				    &needipsectun);
445 	m = state.m;
446 	if (error == EJUSTRETURN) {
447 		/*
448 		 * We had a SP with a level of 'use' and no SA. We
449 		 * will just continue to process the packet without
450 		 * IPsec processing.
451 		 */
452 		;
453 	} else if (error) {
454 		/* mbuf is already reclaimed in ipsec6_output_trans. */
455 		m = NULL;
456 		switch (error) {
457 		case EHOSTUNREACH:
458 		case ENETUNREACH:
459 		case EMSGSIZE:
460 		case ENOBUFS:
461 		case ENOMEM:
462 			break;
463 		default:
464 			printf("[%s:%d] (ipsec): error code %d\n",
465 			    __func__, __LINE__, error);
466 			/* FALLTHROUGH */
467 		case ENOENT:
468 			/* don't show these error codes to the user */
469 			error = 0;
470 			break;
471 		}
472 		goto bad;
473 	} else if (!needipsectun) {
474 		/*
475 		 * In the FAST IPSec case we have already
476 		 * re-injected the packet and it has been freed
477 		 * by the ipsec_done() function.  So, just clean
478 		 * up after ourselves.
479 		 */
480 		m = NULL;
481 		goto done;
482 	}
483 	if (exthdrs.ip6e_rthdr) {
484 		/* ah6_output doesn't modify mbuf chain */
485 		rh->ip6r_segleft = segleft_org;
486 	}
487 skip_ipsec2:;
488 #endif /* IPSEC */
489 
490 	/*
491 	 * If there is a routing header, discard the packet.
492 	 */
493 	if (exthdrs.ip6e_rthdr) {
494 		 error = EINVAL;
495 		 goto bad;
496 	}
497 
498 	/* Source address validation */
499 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
500 	    (flags & IPV6_UNSPECSRC) == 0) {
501 		error = EOPNOTSUPP;
502 		IP6STAT_INC(ip6s_badscope);
503 		goto bad;
504 	}
505 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
506 		error = EOPNOTSUPP;
507 		IP6STAT_INC(ip6s_badscope);
508 		goto bad;
509 	}
510 
511 	IP6STAT_INC(ip6s_localout);
512 
513 	/*
514 	 * Route packet.
515 	 */
516 	if (ro == 0) {
517 		ro = &ip6route;
518 		bzero((caddr_t)ro, sizeof(*ro));
519 	}
520 	ro_pmtu = ro;
521 	if (opt && opt->ip6po_rthdr)
522 		ro = &opt->ip6po_route;
523 	dst = (struct sockaddr_in6 *)&ro->ro_dst;
524 #ifdef FLOWTABLE
525 	if (ro->ro_rt == NULL) {
526 		struct flentry *fle;
527 
528 		/*
529 		 * The flow table returns route entries valid for up to 30
530 		 * seconds; we rely on the remainder of ip_output() taking no
531 		 * longer than that long for the stability of ro_rt.  The
532 		 * flow ID assignment must have happened before this point.
533 		 */
534 		fle = flowtable_lookup_mbuf(V_ip6_ft, m, AF_INET6);
535 		if (fle != NULL)
536 			flow_to_route_in6(fle, ro);
537 	}
538 #endif
539 again:
540 	/*
541 	 * if specified, try to fill in the traffic class field.
542 	 * do not override if a non-zero value is already set.
543 	 * we check the diffserv field and the ecn field separately.
544 	 */
545 	if (opt && opt->ip6po_tclass >= 0) {
546 		int mask = 0;
547 
548 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
549 			mask |= 0xfc;
550 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
551 			mask |= 0x03;
552 		if (mask != 0)
553 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
554 	}
555 
556 	/* fill in or override the hop limit field, if necessary. */
557 	if (opt && opt->ip6po_hlim != -1)
558 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
559 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
560 		if (im6o != NULL)
561 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
562 		else
563 			ip6->ip6_hlim = V_ip6_defmcasthlim;
564 	}
565 
566 #ifdef IPSEC
567 	/*
568 	 * We may re-inject packets into the stack here.
569 	 */
570 	if (needipsec && needipsectun) {
571 		struct ipsec_output_state state;
572 
573 		/*
574 		 * All the extension headers will become inaccessible
575 		 * (since they can be encrypted).
576 		 * Don't panic, we need no more updates to extension headers
577 		 * on inner IPv6 packet (since they are now encapsulated).
578 		 *
579 		 * IPv6 [ESP|AH] IPv6 [extension headers] payload
580 		 */
581 		bzero(&exthdrs, sizeof(exthdrs));
582 		exthdrs.ip6e_ip6 = m;
583 
584 		bzero(&state, sizeof(state));
585 		state.m = m;
586 		state.ro = (struct route *)ro;
587 		state.dst = (struct sockaddr *)dst;
588 
589 		error = ipsec6_output_tunnel(&state, sp, flags);
590 
591 		m = state.m;
592 		ro = (struct route_in6 *)state.ro;
593 		dst = (struct sockaddr_in6 *)state.dst;
594 		if (error == EJUSTRETURN) {
595 			/*
596 			 * We had a SP with a level of 'use' and no SA. We
597 			 * will just continue to process the packet without
598 			 * IPsec processing.
599 			 */
600 			;
601 		} else if (error) {
602 			/* mbuf is already reclaimed in ipsec6_output_tunnel. */
603 			m0 = m = NULL;
604 			m = NULL;
605 			switch (error) {
606 			case EHOSTUNREACH:
607 			case ENETUNREACH:
608 			case EMSGSIZE:
609 			case ENOBUFS:
610 			case ENOMEM:
611 				break;
612 			default:
613 				printf("[%s:%d] (ipsec): error code %d\n",
614 				    __func__, __LINE__, error);
615 				/* FALLTHROUGH */
616 			case ENOENT:
617 				/* don't show these error codes to the user */
618 				error = 0;
619 				break;
620 			}
621 			goto bad;
622 		} else {
623 			/*
624 			 * In the FAST IPSec case we have already
625 			 * re-injected the packet and it has been freed
626 			 * by the ipsec_done() function.  So, just clean
627 			 * up after ourselves.
628 			 */
629 			m = NULL;
630 			goto done;
631 		}
632 
633 		exthdrs.ip6e_ip6 = m;
634 	}
635 #endif /* IPSEC */
636 
637 	/* adjust pointer */
638 	ip6 = mtod(m, struct ip6_hdr *);
639 
640 	if (ro->ro_rt && fwd_tag == NULL) {
641 		rt = ro->ro_rt;
642 		ifp = ro->ro_rt->rt_ifp;
643 	} else {
644 		if (fwd_tag == NULL) {
645 			bzero(&dst_sa, sizeof(dst_sa));
646 			dst_sa.sin6_family = AF_INET6;
647 			dst_sa.sin6_len = sizeof(dst_sa);
648 			dst_sa.sin6_addr = ip6->ip6_dst;
649 		}
650 		error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
651 		    &rt, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
652 		if (error != 0) {
653 			if (ifp != NULL)
654 				in6_ifstat_inc(ifp, ifs6_out_discard);
655 			goto bad;
656 		}
657 	}
658 	if (rt == NULL) {
659 		/*
660 		 * If in6_selectroute() does not return a route entry,
661 		 * dst may not have been updated.
662 		 */
663 		*dst = dst_sa;	/* XXX */
664 	}
665 
666 	/*
667 	 * then rt (for unicast) and ifp must be non-NULL valid values.
668 	 */
669 	if ((flags & IPV6_FORWARDING) == 0) {
670 		/* XXX: the FORWARDING flag can be set for mrouting. */
671 		in6_ifstat_inc(ifp, ifs6_out_request);
672 	}
673 	if (rt != NULL) {
674 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
675 		rt->rt_use++;
676 	}
677 
678 
679 	/*
680 	 * The outgoing interface must be in the zone of source and
681 	 * destination addresses.
682 	 */
683 	origifp = ifp;
684 
685 	src0 = ip6->ip6_src;
686 	if (in6_setscope(&src0, origifp, &zone))
687 		goto badscope;
688 	bzero(&src_sa, sizeof(src_sa));
689 	src_sa.sin6_family = AF_INET6;
690 	src_sa.sin6_len = sizeof(src_sa);
691 	src_sa.sin6_addr = ip6->ip6_src;
692 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
693 		goto badscope;
694 
695 	dst0 = ip6->ip6_dst;
696 	if (in6_setscope(&dst0, origifp, &zone))
697 		goto badscope;
698 	/* re-initialize to be sure */
699 	bzero(&dst_sa, sizeof(dst_sa));
700 	dst_sa.sin6_family = AF_INET6;
701 	dst_sa.sin6_len = sizeof(dst_sa);
702 	dst_sa.sin6_addr = ip6->ip6_dst;
703 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
704 		goto badscope;
705 	}
706 
707 	/* We should use ia_ifp to support the case of
708 	 * sending packets to an address of our own.
709 	 */
710 	if (ia != NULL && ia->ia_ifp)
711 		ifp = ia->ia_ifp;
712 
713 	/* scope check is done. */
714 	goto routefound;
715 
716   badscope:
717 	IP6STAT_INC(ip6s_badscope);
718 	in6_ifstat_inc(origifp, ifs6_out_discard);
719 	if (error == 0)
720 		error = EHOSTUNREACH; /* XXX */
721 	goto bad;
722 
723   routefound:
724 	if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
725 		if (opt && opt->ip6po_nextroute.ro_rt) {
726 			/*
727 			 * The nexthop is explicitly specified by the
728 			 * application.  We assume the next hop is an IPv6
729 			 * address.
730 			 */
731 			dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
732 		}
733 		else if ((rt->rt_flags & RTF_GATEWAY))
734 			dst = (struct sockaddr_in6 *)rt->rt_gateway;
735 	}
736 
737 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
738 		m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
739 	} else {
740 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
741 		in6_ifstat_inc(ifp, ifs6_out_mcast);
742 		/*
743 		 * Confirm that the outgoing interface supports multicast.
744 		 */
745 		if (!(ifp->if_flags & IFF_MULTICAST)) {
746 			IP6STAT_INC(ip6s_noroute);
747 			in6_ifstat_inc(ifp, ifs6_out_discard);
748 			error = ENETUNREACH;
749 			goto bad;
750 		}
751 		if ((im6o == NULL && in6_mcast_loop) ||
752 		    (im6o && im6o->im6o_multicast_loop)) {
753 			/*
754 			 * Loop back multicast datagram if not expressly
755 			 * forbidden to do so, even if we have not joined
756 			 * the address; protocols will filter it later,
757 			 * thus deferring a hash lookup and lock acquisition
758 			 * at the expense of an m_copym().
759 			 */
760 			ip6_mloopback(ifp, m, dst);
761 		} else {
762 			/*
763 			 * If we are acting as a multicast router, perform
764 			 * multicast forwarding as if the packet had just
765 			 * arrived on the interface to which we are about
766 			 * to send.  The multicast forwarding function
767 			 * recursively calls this function, using the
768 			 * IPV6_FORWARDING flag to prevent infinite recursion.
769 			 *
770 			 * Multicasts that are looped back by ip6_mloopback(),
771 			 * above, will be forwarded by the ip6_input() routine,
772 			 * if necessary.
773 			 */
774 			if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
775 				/*
776 				 * XXX: ip6_mforward expects that rcvif is NULL
777 				 * when it is called from the originating path.
778 				 * However, it may not always be the case.
779 				 */
780 				m->m_pkthdr.rcvif = NULL;
781 				if (ip6_mforward(ip6, ifp, m) != 0) {
782 					m_freem(m);
783 					goto done;
784 				}
785 			}
786 		}
787 		/*
788 		 * Multicasts with a hoplimit of zero may be looped back,
789 		 * above, but must not be transmitted on a network.
790 		 * Also, multicasts addressed to the loopback interface
791 		 * are not sent -- the above call to ip6_mloopback() will
792 		 * loop back a copy if this host actually belongs to the
793 		 * destination group on the loopback interface.
794 		 */
795 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
796 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
797 			m_freem(m);
798 			goto done;
799 		}
800 	}
801 
802 	/*
803 	 * Fill the outgoing inteface to tell the upper layer
804 	 * to increment per-interface statistics.
805 	 */
806 	if (ifpp)
807 		*ifpp = ifp;
808 
809 	/* Determine path MTU. */
810 	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
811 	    &alwaysfrag, inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m))) != 0)
812 		goto bad;
813 
814 	/*
815 	 * The caller of this function may specify to use the minimum MTU
816 	 * in some cases.
817 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
818 	 * setting.  The logic is a bit complicated; by default, unicast
819 	 * packets will follow path MTU while multicast packets will be sent at
820 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
821 	 * including unicast ones will be sent at the minimum MTU.  Multicast
822 	 * packets will always be sent at the minimum MTU unless
823 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
824 	 * See RFC 3542 for more details.
825 	 */
826 	if (mtu > IPV6_MMTU) {
827 		if ((flags & IPV6_MINMTU))
828 			mtu = IPV6_MMTU;
829 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
830 			mtu = IPV6_MMTU;
831 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
832 			 (opt == NULL ||
833 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
834 			mtu = IPV6_MMTU;
835 		}
836 	}
837 
838 	/*
839 	 * clear embedded scope identifiers if necessary.
840 	 * in6_clearscope will touch the addresses only when necessary.
841 	 */
842 	in6_clearscope(&ip6->ip6_src);
843 	in6_clearscope(&ip6->ip6_dst);
844 
845 	/*
846 	 * If the outgoing packet contains a hop-by-hop options header,
847 	 * it must be examined and processed even by the source node.
848 	 * (RFC 2460, section 4.)
849 	 */
850 	if (exthdrs.ip6e_hbh) {
851 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
852 		u_int32_t dummy; /* XXX unused */
853 		u_int32_t plen = 0; /* XXX: ip6_process will check the value */
854 
855 #ifdef DIAGNOSTIC
856 		if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
857 			panic("ip6e_hbh is not contiguous");
858 #endif
859 		/*
860 		 *  XXX: if we have to send an ICMPv6 error to the sender,
861 		 *       we need the M_LOOP flag since icmp6_error() expects
862 		 *       the IPv6 and the hop-by-hop options header are
863 		 *       contiguous unless the flag is set.
864 		 */
865 		m->m_flags |= M_LOOP;
866 		m->m_pkthdr.rcvif = ifp;
867 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
868 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
869 		    &dummy, &plen) < 0) {
870 			/* m was already freed at this point */
871 			error = EINVAL;/* better error? */
872 			goto done;
873 		}
874 		m->m_flags &= ~M_LOOP; /* XXX */
875 		m->m_pkthdr.rcvif = NULL;
876 	}
877 
878 	/* Jump over all PFIL processing if hooks are not active. */
879 	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
880 		goto passout;
881 
882 	odst = ip6->ip6_dst;
883 	/* Run through list of hooks for output packets. */
884 	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
885 	if (error != 0 || m == NULL)
886 		goto done;
887 	ip6 = mtod(m, struct ip6_hdr *);
888 
889 	/* See if destination IP address was changed by packet filter. */
890 	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
891 		m->m_flags |= M_SKIP_FIREWALL;
892 		/* If destination is now ourself drop to ip6_input(). */
893 		if (in6_localip(&ip6->ip6_dst)) {
894 			m->m_flags |= M_FASTFWD_OURS;
895 			if (m->m_pkthdr.rcvif == NULL)
896 				m->m_pkthdr.rcvif = V_loif;
897 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
898 				m->m_pkthdr.csum_flags |=
899 				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
900 				m->m_pkthdr.csum_data = 0xffff;
901 			}
902 #ifdef SCTP
903 			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
904 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
905 #endif
906 			error = netisr_queue(NETISR_IPV6, m);
907 			goto done;
908 		} else
909 			goto again;	/* Redo the routing table lookup. */
910 	}
911 
912 	/* See if local, if yes, send it to netisr. */
913 	if (m->m_flags & M_FASTFWD_OURS) {
914 		if (m->m_pkthdr.rcvif == NULL)
915 			m->m_pkthdr.rcvif = V_loif;
916 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
917 			m->m_pkthdr.csum_flags |=
918 			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
919 			m->m_pkthdr.csum_data = 0xffff;
920 		}
921 #ifdef SCTP
922 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
923 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
924 #endif
925 		error = netisr_queue(NETISR_IPV6, m);
926 		goto done;
927 	}
928 	/* Or forward to some other address? */
929 	if ((m->m_flags & M_IP6_NEXTHOP) &&
930 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
931 		dst = (struct sockaddr_in6 *)&ro->ro_dst;
932 		bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
933 		m->m_flags |= M_SKIP_FIREWALL;
934 		m->m_flags &= ~M_IP6_NEXTHOP;
935 		m_tag_delete(m, fwd_tag);
936 		goto again;
937 	}
938 
939 passout:
940 	/*
941 	 * Send the packet to the outgoing interface.
942 	 * If necessary, do IPv6 fragmentation before sending.
943 	 *
944 	 * the logic here is rather complex:
945 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
946 	 * 1-a:	send as is if tlen <= path mtu
947 	 * 1-b:	fragment if tlen > path mtu
948 	 *
949 	 * 2: if user asks us not to fragment (dontfrag == 1)
950 	 * 2-a:	send as is if tlen <= interface mtu
951 	 * 2-b:	error if tlen > interface mtu
952 	 *
953 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
954 	 *	always fragment
955 	 *
956 	 * 4: if dontfrag == 1 && alwaysfrag == 1
957 	 *	error, as we cannot handle this conflicting request
958 	 */
959 	sw_csum = m->m_pkthdr.csum_flags;
960 	if (!hdrsplit) {
961 		tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
962 		sw_csum &= ~ifp->if_hwassist;
963 	} else
964 		tso = 0;
965 	/*
966 	 * If we added extension headers, we will not do TSO and calculate the
967 	 * checksums ourselves for now.
968 	 * XXX-BZ  Need a framework to know when the NIC can handle it, even
969 	 * with ext. hdrs.
970 	 */
971 	if (sw_csum & CSUM_DELAY_DATA_IPV6) {
972 		sw_csum &= ~CSUM_DELAY_DATA_IPV6;
973 		in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
974 	}
975 #ifdef SCTP
976 	if (sw_csum & CSUM_SCTP_IPV6) {
977 		sw_csum &= ~CSUM_SCTP_IPV6;
978 		sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
979 	}
980 #endif
981 	m->m_pkthdr.csum_flags &= ifp->if_hwassist;
982 	tlen = m->m_pkthdr.len;
983 
984 	if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
985 		dontfrag = 1;
986 	else
987 		dontfrag = 0;
988 	if (dontfrag && alwaysfrag) {	/* case 4 */
989 		/* conflicting request - can't transmit */
990 		error = EMSGSIZE;
991 		goto bad;
992 	}
993 	if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {	/* case 2-b */
994 		/*
995 		 * Even if the DONTFRAG option is specified, we cannot send the
996 		 * packet when the data length is larger than the MTU of the
997 		 * outgoing interface.
998 		 * Notify the error by sending IPV6_PATHMTU ancillary data as
999 		 * well as returning an error code (the latter is not described
1000 		 * in the API spec.)
1001 		 */
1002 		u_int32_t mtu32;
1003 		struct ip6ctlparam ip6cp;
1004 
1005 		mtu32 = (u_int32_t)mtu;
1006 		bzero(&ip6cp, sizeof(ip6cp));
1007 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
1008 		pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
1009 		    (void *)&ip6cp);
1010 
1011 		error = EMSGSIZE;
1012 		goto bad;
1013 	}
1014 
1015 	/*
1016 	 * transmit packet without fragmentation
1017 	 */
1018 	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* case 1-a and 2-a */
1019 		struct in6_ifaddr *ia6;
1020 
1021 		ip6 = mtod(m, struct ip6_hdr *);
1022 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
1023 		if (ia6) {
1024 			/* Record statistics for this interface address. */
1025 			counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
1026 			counter_u64_add(ia6->ia_ifa.ifa_obytes,
1027 			    m->m_pkthdr.len);
1028 			ifa_free(&ia6->ia_ifa);
1029 		}
1030 		error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1031 		goto done;
1032 	}
1033 
1034 	/*
1035 	 * try to fragment the packet.  case 1-b and 3
1036 	 */
1037 	if (mtu < IPV6_MMTU) {
1038 		/* path MTU cannot be less than IPV6_MMTU */
1039 		error = EMSGSIZE;
1040 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1041 		goto bad;
1042 	} else if (ip6->ip6_plen == 0) {
1043 		/* jumbo payload cannot be fragmented */
1044 		error = EMSGSIZE;
1045 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
1046 		goto bad;
1047 	} else {
1048 		struct mbuf **mnext, *m_frgpart;
1049 		struct ip6_frag *ip6f;
1050 		u_int32_t id = htonl(ip6_randomid());
1051 		u_char nextproto;
1052 
1053 		int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
1054 
1055 		/*
1056 		 * Too large for the destination or interface;
1057 		 * fragment if possible.
1058 		 * Must be able to put at least 8 bytes per fragment.
1059 		 */
1060 		hlen = unfragpartlen;
1061 		if (mtu > IPV6_MAXPACKET)
1062 			mtu = IPV6_MAXPACKET;
1063 
1064 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
1065 		if (len < 8) {
1066 			error = EMSGSIZE;
1067 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
1068 			goto bad;
1069 		}
1070 
1071 		/*
1072 		 * Verify that we have any chance at all of being able to queue
1073 		 *      the packet or packet fragments
1074 		 */
1075 		if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
1076 		    < tlen  /* - hlen */)) {
1077 			error = ENOBUFS;
1078 			IP6STAT_INC(ip6s_odropped);
1079 			goto bad;
1080 		}
1081 
1082 
1083 		/*
1084 		 * If the interface will not calculate checksums on
1085 		 * fragmented packets, then do it here.
1086 		 * XXX-BZ handle the hw offloading case.  Need flags.
1087 		 */
1088 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1089 			in6_delayed_cksum(m, plen, hlen);
1090 			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
1091 		}
1092 #ifdef SCTP
1093 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
1094 			sctp_delayed_cksum(m, hlen);
1095 			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
1096 		}
1097 #endif
1098 		mnext = &m->m_nextpkt;
1099 
1100 		/*
1101 		 * Change the next header field of the last header in the
1102 		 * unfragmentable part.
1103 		 */
1104 		if (exthdrs.ip6e_rthdr) {
1105 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1106 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1107 		} else if (exthdrs.ip6e_dest1) {
1108 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1109 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1110 		} else if (exthdrs.ip6e_hbh) {
1111 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1112 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1113 		} else {
1114 			nextproto = ip6->ip6_nxt;
1115 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
1116 		}
1117 
1118 		/*
1119 		 * Loop through length of segment after first fragment,
1120 		 * make new header and copy data of each part and link onto
1121 		 * chain.
1122 		 */
1123 		m0 = m;
1124 		for (off = hlen; off < tlen; off += len) {
1125 			m = m_gethdr(M_NOWAIT, MT_DATA);
1126 			if (!m) {
1127 				error = ENOBUFS;
1128 				IP6STAT_INC(ip6s_odropped);
1129 				goto sendorfree;
1130 			}
1131 			m->m_flags = m0->m_flags & M_COPYFLAGS;
1132 			*mnext = m;
1133 			mnext = &m->m_nextpkt;
1134 			m->m_data += max_linkhdr;
1135 			mhip6 = mtod(m, struct ip6_hdr *);
1136 			*mhip6 = *ip6;
1137 			m->m_len = sizeof(*mhip6);
1138 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1139 			if (error) {
1140 				IP6STAT_INC(ip6s_odropped);
1141 				goto sendorfree;
1142 			}
1143 			ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1144 			if (off + len >= tlen)
1145 				len = tlen - off;
1146 			else
1147 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1148 			mhip6->ip6_plen = htons((u_short)(len + hlen +
1149 			    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1150 			if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1151 				error = ENOBUFS;
1152 				IP6STAT_INC(ip6s_odropped);
1153 				goto sendorfree;
1154 			}
1155 			m_cat(m, m_frgpart);
1156 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1157 			m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
1158 			m->m_pkthdr.rcvif = NULL;
1159 			ip6f->ip6f_reserved = 0;
1160 			ip6f->ip6f_ident = id;
1161 			ip6f->ip6f_nxt = nextproto;
1162 			IP6STAT_INC(ip6s_ofragments);
1163 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1164 		}
1165 
1166 		in6_ifstat_inc(ifp, ifs6_out_fragok);
1167 	}
1168 
1169 	/*
1170 	 * Remove leading garbages.
1171 	 */
1172 sendorfree:
1173 	m = m0->m_nextpkt;
1174 	m0->m_nextpkt = 0;
1175 	m_freem(m0);
1176 	for (m0 = m; m; m = m0) {
1177 		m0 = m->m_nextpkt;
1178 		m->m_nextpkt = 0;
1179 		if (error == 0) {
1180 			/* Record statistics for this interface address. */
1181 			if (ia) {
1182 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1183 				counter_u64_add(ia->ia_ifa.ifa_obytes,
1184 				    m->m_pkthdr.len);
1185 			}
1186 			error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1187 		} else
1188 			m_freem(m);
1189 	}
1190 
1191 	if (error == 0)
1192 		IP6STAT_INC(ip6s_fragmented);
1193 
1194 done:
1195 	if (ro == &ip6route)
1196 		RO_RTFREE(ro);
1197 	if (ro_pmtu == &ip6route)
1198 		RO_RTFREE(ro_pmtu);
1199 #ifdef IPSEC
1200 	if (sp != NULL)
1201 		KEY_FREESP(&sp);
1202 #endif
1203 
1204 	return (error);
1205 
1206 freehdrs:
1207 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
1208 	m_freem(exthdrs.ip6e_dest1);
1209 	m_freem(exthdrs.ip6e_rthdr);
1210 	m_freem(exthdrs.ip6e_dest2);
1211 	/* FALLTHROUGH */
1212 bad:
1213 	if (m)
1214 		m_freem(m);
1215 	goto done;
1216 }
1217 
1218 static int
1219 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1220 {
1221 	struct mbuf *m;
1222 
1223 	if (hlen > MCLBYTES)
1224 		return (ENOBUFS); /* XXX */
1225 
1226 	if (hlen > MLEN)
1227 		m = m_getcl(M_NOWAIT, MT_DATA, 0);
1228 	else
1229 		m = m_get(M_NOWAIT, MT_DATA);
1230 	if (m == NULL)
1231 		return (ENOBUFS);
1232 	m->m_len = hlen;
1233 	if (hdr)
1234 		bcopy(hdr, mtod(m, caddr_t), hlen);
1235 
1236 	*mp = m;
1237 	return (0);
1238 }
1239 
1240 /*
1241  * Insert jumbo payload option.
1242  */
1243 static int
1244 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1245 {
1246 	struct mbuf *mopt;
1247 	u_char *optbuf;
1248 	u_int32_t v;
1249 
1250 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
1251 
1252 	/*
1253 	 * If there is no hop-by-hop options header, allocate new one.
1254 	 * If there is one but it doesn't have enough space to store the
1255 	 * jumbo payload option, allocate a cluster to store the whole options.
1256 	 * Otherwise, use it to store the options.
1257 	 */
1258 	if (exthdrs->ip6e_hbh == 0) {
1259 		mopt = m_get(M_NOWAIT, MT_DATA);
1260 		if (mopt == NULL)
1261 			return (ENOBUFS);
1262 		mopt->m_len = JUMBOOPTLEN;
1263 		optbuf = mtod(mopt, u_char *);
1264 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
1265 		exthdrs->ip6e_hbh = mopt;
1266 	} else {
1267 		struct ip6_hbh *hbh;
1268 
1269 		mopt = exthdrs->ip6e_hbh;
1270 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1271 			/*
1272 			 * XXX assumption:
1273 			 * - exthdrs->ip6e_hbh is not referenced from places
1274 			 *   other than exthdrs.
1275 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
1276 			 */
1277 			int oldoptlen = mopt->m_len;
1278 			struct mbuf *n;
1279 
1280 			/*
1281 			 * XXX: give up if the whole (new) hbh header does
1282 			 * not fit even in an mbuf cluster.
1283 			 */
1284 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1285 				return (ENOBUFS);
1286 
1287 			/*
1288 			 * As a consequence, we must always prepare a cluster
1289 			 * at this point.
1290 			 */
1291 			n = m_getcl(M_NOWAIT, MT_DATA, 0);
1292 			if (n == NULL)
1293 				return (ENOBUFS);
1294 			n->m_len = oldoptlen + JUMBOOPTLEN;
1295 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1296 			    oldoptlen);
1297 			optbuf = mtod(n, caddr_t) + oldoptlen;
1298 			m_freem(mopt);
1299 			mopt = exthdrs->ip6e_hbh = n;
1300 		} else {
1301 			optbuf = mtod(mopt, u_char *) + mopt->m_len;
1302 			mopt->m_len += JUMBOOPTLEN;
1303 		}
1304 		optbuf[0] = IP6OPT_PADN;
1305 		optbuf[1] = 1;
1306 
1307 		/*
1308 		 * Adjust the header length according to the pad and
1309 		 * the jumbo payload option.
1310 		 */
1311 		hbh = mtod(mopt, struct ip6_hbh *);
1312 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1313 	}
1314 
1315 	/* fill in the option. */
1316 	optbuf[2] = IP6OPT_JUMBO;
1317 	optbuf[3] = 4;
1318 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1319 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1320 
1321 	/* finally, adjust the packet header length */
1322 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1323 
1324 	return (0);
1325 #undef JUMBOOPTLEN
1326 }
1327 
1328 /*
1329  * Insert fragment header and copy unfragmentable header portions.
1330  */
1331 static int
1332 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1333     struct ip6_frag **frghdrp)
1334 {
1335 	struct mbuf *n, *mlast;
1336 
1337 	if (hlen > sizeof(struct ip6_hdr)) {
1338 		n = m_copym(m0, sizeof(struct ip6_hdr),
1339 		    hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1340 		if (n == 0)
1341 			return (ENOBUFS);
1342 		m->m_next = n;
1343 	} else
1344 		n = m;
1345 
1346 	/* Search for the last mbuf of unfragmentable part. */
1347 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1348 		;
1349 
1350 	if ((mlast->m_flags & M_EXT) == 0 &&
1351 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1352 		/* use the trailing space of the last mbuf for the fragment hdr */
1353 		*frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1354 		    mlast->m_len);
1355 		mlast->m_len += sizeof(struct ip6_frag);
1356 		m->m_pkthdr.len += sizeof(struct ip6_frag);
1357 	} else {
1358 		/* allocate a new mbuf for the fragment header */
1359 		struct mbuf *mfrg;
1360 
1361 		mfrg = m_get(M_NOWAIT, MT_DATA);
1362 		if (mfrg == NULL)
1363 			return (ENOBUFS);
1364 		mfrg->m_len = sizeof(struct ip6_frag);
1365 		*frghdrp = mtod(mfrg, struct ip6_frag *);
1366 		mlast->m_next = mfrg;
1367 	}
1368 
1369 	return (0);
1370 }
1371 
1372 static int
1373 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1374     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1375     int *alwaysfragp, u_int fibnum)
1376 {
1377 	u_int32_t mtu = 0;
1378 	int alwaysfrag = 0;
1379 	int error = 0;
1380 
1381 	if (ro_pmtu != ro) {
1382 		/* The first hop and the final destination may differ. */
1383 		struct sockaddr_in6 *sa6_dst =
1384 		    (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1385 		if (ro_pmtu->ro_rt &&
1386 		    ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1387 		     !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1388 			RTFREE(ro_pmtu->ro_rt);
1389 			ro_pmtu->ro_rt = (struct rtentry *)NULL;
1390 		}
1391 		if (ro_pmtu->ro_rt == NULL) {
1392 			bzero(sa6_dst, sizeof(*sa6_dst));
1393 			sa6_dst->sin6_family = AF_INET6;
1394 			sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1395 			sa6_dst->sin6_addr = *dst;
1396 
1397 			in6_rtalloc(ro_pmtu, fibnum);
1398 		}
1399 	}
1400 	if (ro_pmtu->ro_rt) {
1401 		u_int32_t ifmtu;
1402 		struct in_conninfo inc;
1403 
1404 		bzero(&inc, sizeof(inc));
1405 		inc.inc_flags |= INC_ISIPV6;
1406 		inc.inc6_faddr = *dst;
1407 
1408 		if (ifp == NULL)
1409 			ifp = ro_pmtu->ro_rt->rt_ifp;
1410 		ifmtu = IN6_LINKMTU(ifp);
1411 		mtu = tcp_hc_getmtu(&inc);
1412 		if (mtu)
1413 			mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
1414 		else
1415 			mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1416 		if (mtu == 0)
1417 			mtu = ifmtu;
1418 		else if (mtu < IPV6_MMTU) {
1419 			/*
1420 			 * RFC2460 section 5, last paragraph:
1421 			 * if we record ICMPv6 too big message with
1422 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1423 			 * or smaller, with framgent header attached.
1424 			 * (fragment header is needed regardless from the
1425 			 * packet size, for translators to identify packets)
1426 			 */
1427 			alwaysfrag = 1;
1428 			mtu = IPV6_MMTU;
1429 		} else if (mtu > ifmtu) {
1430 			/*
1431 			 * The MTU on the route is larger than the MTU on
1432 			 * the interface!  This shouldn't happen, unless the
1433 			 * MTU of the interface has been changed after the
1434 			 * interface was brought up.  Change the MTU in the
1435 			 * route to match the interface MTU (as long as the
1436 			 * field isn't locked).
1437 			 */
1438 			mtu = ifmtu;
1439 			ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1440 		}
1441 	} else if (ifp) {
1442 		mtu = IN6_LINKMTU(ifp);
1443 	} else
1444 		error = EHOSTUNREACH; /* XXX */
1445 
1446 	*mtup = mtu;
1447 	if (alwaysfragp)
1448 		*alwaysfragp = alwaysfrag;
1449 	return (error);
1450 }
1451 
1452 /*
1453  * IP6 socket option processing.
1454  */
1455 int
1456 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1457 {
1458 	int optdatalen, uproto;
1459 	void *optdata;
1460 	struct inpcb *in6p = sotoinpcb(so);
1461 	int error, optval;
1462 	int level, op, optname;
1463 	int optlen;
1464 	struct thread *td;
1465 
1466 	level = sopt->sopt_level;
1467 	op = sopt->sopt_dir;
1468 	optname = sopt->sopt_name;
1469 	optlen = sopt->sopt_valsize;
1470 	td = sopt->sopt_td;
1471 	error = 0;
1472 	optval = 0;
1473 	uproto = (int)so->so_proto->pr_protocol;
1474 
1475 	if (level != IPPROTO_IPV6) {
1476 		error = EINVAL;
1477 
1478 		if (sopt->sopt_level == SOL_SOCKET &&
1479 		    sopt->sopt_dir == SOPT_SET) {
1480 			switch (sopt->sopt_name) {
1481 			case SO_REUSEADDR:
1482 				INP_WLOCK(in6p);
1483 				if ((so->so_options & SO_REUSEADDR) != 0)
1484 					in6p->inp_flags2 |= INP_REUSEADDR;
1485 				else
1486 					in6p->inp_flags2 &= ~INP_REUSEADDR;
1487 				INP_WUNLOCK(in6p);
1488 				error = 0;
1489 				break;
1490 			case SO_REUSEPORT:
1491 				INP_WLOCK(in6p);
1492 				if ((so->so_options & SO_REUSEPORT) != 0)
1493 					in6p->inp_flags2 |= INP_REUSEPORT;
1494 				else
1495 					in6p->inp_flags2 &= ~INP_REUSEPORT;
1496 				INP_WUNLOCK(in6p);
1497 				error = 0;
1498 				break;
1499 			case SO_SETFIB:
1500 				INP_WLOCK(in6p);
1501 				in6p->inp_inc.inc_fibnum = so->so_fibnum;
1502 				INP_WUNLOCK(in6p);
1503 				error = 0;
1504 				break;
1505 			default:
1506 				break;
1507 			}
1508 		}
1509 	} else {		/* level == IPPROTO_IPV6 */
1510 		switch (op) {
1511 
1512 		case SOPT_SET:
1513 			switch (optname) {
1514 			case IPV6_2292PKTOPTIONS:
1515 #ifdef IPV6_PKTOPTIONS
1516 			case IPV6_PKTOPTIONS:
1517 #endif
1518 			{
1519 				struct mbuf *m;
1520 
1521 				error = soopt_getm(sopt, &m); /* XXX */
1522 				if (error != 0)
1523 					break;
1524 				error = soopt_mcopyin(sopt, m); /* XXX */
1525 				if (error != 0)
1526 					break;
1527 				error = ip6_pcbopts(&in6p->in6p_outputopts,
1528 						    m, so, sopt);
1529 				m_freem(m); /* XXX */
1530 				break;
1531 			}
1532 
1533 			/*
1534 			 * Use of some Hop-by-Hop options or some
1535 			 * Destination options, might require special
1536 			 * privilege.  That is, normal applications
1537 			 * (without special privilege) might be forbidden
1538 			 * from setting certain options in outgoing packets,
1539 			 * and might never see certain options in received
1540 			 * packets. [RFC 2292 Section 6]
1541 			 * KAME specific note:
1542 			 *  KAME prevents non-privileged users from sending or
1543 			 *  receiving ANY hbh/dst options in order to avoid
1544 			 *  overhead of parsing options in the kernel.
1545 			 */
1546 			case IPV6_RECVHOPOPTS:
1547 			case IPV6_RECVDSTOPTS:
1548 			case IPV6_RECVRTHDRDSTOPTS:
1549 				if (td != NULL) {
1550 					error = priv_check(td,
1551 					    PRIV_NETINET_SETHDROPTS);
1552 					if (error)
1553 						break;
1554 				}
1555 				/* FALLTHROUGH */
1556 			case IPV6_UNICAST_HOPS:
1557 			case IPV6_HOPLIMIT:
1558 			case IPV6_FAITH:
1559 
1560 			case IPV6_RECVPKTINFO:
1561 			case IPV6_RECVHOPLIMIT:
1562 			case IPV6_RECVRTHDR:
1563 			case IPV6_RECVPATHMTU:
1564 			case IPV6_RECVTCLASS:
1565 			case IPV6_V6ONLY:
1566 			case IPV6_AUTOFLOWLABEL:
1567 			case IPV6_BINDANY:
1568 				if (optname == IPV6_BINDANY && td != NULL) {
1569 					error = priv_check(td,
1570 					    PRIV_NETINET_BINDANY);
1571 					if (error)
1572 						break;
1573 				}
1574 
1575 				if (optlen != sizeof(int)) {
1576 					error = EINVAL;
1577 					break;
1578 				}
1579 				error = sooptcopyin(sopt, &optval,
1580 					sizeof optval, sizeof optval);
1581 				if (error)
1582 					break;
1583 				switch (optname) {
1584 
1585 				case IPV6_UNICAST_HOPS:
1586 					if (optval < -1 || optval >= 256)
1587 						error = EINVAL;
1588 					else {
1589 						/* -1 = kernel default */
1590 						in6p->in6p_hops = optval;
1591 						if ((in6p->inp_vflag &
1592 						     INP_IPV4) != 0)
1593 							in6p->inp_ip_ttl = optval;
1594 					}
1595 					break;
1596 #define OPTSET(bit) \
1597 do { \
1598 	INP_WLOCK(in6p); \
1599 	if (optval) \
1600 		in6p->inp_flags |= (bit); \
1601 	else \
1602 		in6p->inp_flags &= ~(bit); \
1603 	INP_WUNLOCK(in6p); \
1604 } while (/*CONSTCOND*/ 0)
1605 #define OPTSET2292(bit) \
1606 do { \
1607 	INP_WLOCK(in6p); \
1608 	in6p->inp_flags |= IN6P_RFC2292; \
1609 	if (optval) \
1610 		in6p->inp_flags |= (bit); \
1611 	else \
1612 		in6p->inp_flags &= ~(bit); \
1613 	INP_WUNLOCK(in6p); \
1614 } while (/*CONSTCOND*/ 0)
1615 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1616 
1617 				case IPV6_RECVPKTINFO:
1618 					/* cannot mix with RFC2292 */
1619 					if (OPTBIT(IN6P_RFC2292)) {
1620 						error = EINVAL;
1621 						break;
1622 					}
1623 					OPTSET(IN6P_PKTINFO);
1624 					break;
1625 
1626 				case IPV6_HOPLIMIT:
1627 				{
1628 					struct ip6_pktopts **optp;
1629 
1630 					/* cannot mix with RFC2292 */
1631 					if (OPTBIT(IN6P_RFC2292)) {
1632 						error = EINVAL;
1633 						break;
1634 					}
1635 					optp = &in6p->in6p_outputopts;
1636 					error = ip6_pcbopt(IPV6_HOPLIMIT,
1637 					    (u_char *)&optval, sizeof(optval),
1638 					    optp, (td != NULL) ? td->td_ucred :
1639 					    NULL, uproto);
1640 					break;
1641 				}
1642 
1643 				case IPV6_RECVHOPLIMIT:
1644 					/* cannot mix with RFC2292 */
1645 					if (OPTBIT(IN6P_RFC2292)) {
1646 						error = EINVAL;
1647 						break;
1648 					}
1649 					OPTSET(IN6P_HOPLIMIT);
1650 					break;
1651 
1652 				case IPV6_RECVHOPOPTS:
1653 					/* cannot mix with RFC2292 */
1654 					if (OPTBIT(IN6P_RFC2292)) {
1655 						error = EINVAL;
1656 						break;
1657 					}
1658 					OPTSET(IN6P_HOPOPTS);
1659 					break;
1660 
1661 				case IPV6_RECVDSTOPTS:
1662 					/* cannot mix with RFC2292 */
1663 					if (OPTBIT(IN6P_RFC2292)) {
1664 						error = EINVAL;
1665 						break;
1666 					}
1667 					OPTSET(IN6P_DSTOPTS);
1668 					break;
1669 
1670 				case IPV6_RECVRTHDRDSTOPTS:
1671 					/* cannot mix with RFC2292 */
1672 					if (OPTBIT(IN6P_RFC2292)) {
1673 						error = EINVAL;
1674 						break;
1675 					}
1676 					OPTSET(IN6P_RTHDRDSTOPTS);
1677 					break;
1678 
1679 				case IPV6_RECVRTHDR:
1680 					/* cannot mix with RFC2292 */
1681 					if (OPTBIT(IN6P_RFC2292)) {
1682 						error = EINVAL;
1683 						break;
1684 					}
1685 					OPTSET(IN6P_RTHDR);
1686 					break;
1687 
1688 				case IPV6_FAITH:
1689 					OPTSET(INP_FAITH);
1690 					break;
1691 
1692 				case IPV6_RECVPATHMTU:
1693 					/*
1694 					 * We ignore this option for TCP
1695 					 * sockets.
1696 					 * (RFC3542 leaves this case
1697 					 * unspecified.)
1698 					 */
1699 					if (uproto != IPPROTO_TCP)
1700 						OPTSET(IN6P_MTU);
1701 					break;
1702 
1703 				case IPV6_V6ONLY:
1704 					/*
1705 					 * make setsockopt(IPV6_V6ONLY)
1706 					 * available only prior to bind(2).
1707 					 * see ipng mailing list, Jun 22 2001.
1708 					 */
1709 					if (in6p->inp_lport ||
1710 					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1711 						error = EINVAL;
1712 						break;
1713 					}
1714 					OPTSET(IN6P_IPV6_V6ONLY);
1715 					if (optval)
1716 						in6p->inp_vflag &= ~INP_IPV4;
1717 					else
1718 						in6p->inp_vflag |= INP_IPV4;
1719 					break;
1720 				case IPV6_RECVTCLASS:
1721 					/* cannot mix with RFC2292 XXX */
1722 					if (OPTBIT(IN6P_RFC2292)) {
1723 						error = EINVAL;
1724 						break;
1725 					}
1726 					OPTSET(IN6P_TCLASS);
1727 					break;
1728 				case IPV6_AUTOFLOWLABEL:
1729 					OPTSET(IN6P_AUTOFLOWLABEL);
1730 					break;
1731 
1732 				case IPV6_BINDANY:
1733 					OPTSET(INP_BINDANY);
1734 					break;
1735 				}
1736 				break;
1737 
1738 			case IPV6_TCLASS:
1739 			case IPV6_DONTFRAG:
1740 			case IPV6_USE_MIN_MTU:
1741 			case IPV6_PREFER_TEMPADDR:
1742 				if (optlen != sizeof(optval)) {
1743 					error = EINVAL;
1744 					break;
1745 				}
1746 				error = sooptcopyin(sopt, &optval,
1747 					sizeof optval, sizeof optval);
1748 				if (error)
1749 					break;
1750 				{
1751 					struct ip6_pktopts **optp;
1752 					optp = &in6p->in6p_outputopts;
1753 					error = ip6_pcbopt(optname,
1754 					    (u_char *)&optval, sizeof(optval),
1755 					    optp, (td != NULL) ? td->td_ucred :
1756 					    NULL, uproto);
1757 					break;
1758 				}
1759 
1760 			case IPV6_2292PKTINFO:
1761 			case IPV6_2292HOPLIMIT:
1762 			case IPV6_2292HOPOPTS:
1763 			case IPV6_2292DSTOPTS:
1764 			case IPV6_2292RTHDR:
1765 				/* RFC 2292 */
1766 				if (optlen != sizeof(int)) {
1767 					error = EINVAL;
1768 					break;
1769 				}
1770 				error = sooptcopyin(sopt, &optval,
1771 					sizeof optval, sizeof optval);
1772 				if (error)
1773 					break;
1774 				switch (optname) {
1775 				case IPV6_2292PKTINFO:
1776 					OPTSET2292(IN6P_PKTINFO);
1777 					break;
1778 				case IPV6_2292HOPLIMIT:
1779 					OPTSET2292(IN6P_HOPLIMIT);
1780 					break;
1781 				case IPV6_2292HOPOPTS:
1782 					/*
1783 					 * Check super-user privilege.
1784 					 * See comments for IPV6_RECVHOPOPTS.
1785 					 */
1786 					if (td != NULL) {
1787 						error = priv_check(td,
1788 						    PRIV_NETINET_SETHDROPTS);
1789 						if (error)
1790 							return (error);
1791 					}
1792 					OPTSET2292(IN6P_HOPOPTS);
1793 					break;
1794 				case IPV6_2292DSTOPTS:
1795 					if (td != NULL) {
1796 						error = priv_check(td,
1797 						    PRIV_NETINET_SETHDROPTS);
1798 						if (error)
1799 							return (error);
1800 					}
1801 					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1802 					break;
1803 				case IPV6_2292RTHDR:
1804 					OPTSET2292(IN6P_RTHDR);
1805 					break;
1806 				}
1807 				break;
1808 			case IPV6_PKTINFO:
1809 			case IPV6_HOPOPTS:
1810 			case IPV6_RTHDR:
1811 			case IPV6_DSTOPTS:
1812 			case IPV6_RTHDRDSTOPTS:
1813 			case IPV6_NEXTHOP:
1814 			{
1815 				/* new advanced API (RFC3542) */
1816 				u_char *optbuf;
1817 				u_char optbuf_storage[MCLBYTES];
1818 				int optlen;
1819 				struct ip6_pktopts **optp;
1820 
1821 				/* cannot mix with RFC2292 */
1822 				if (OPTBIT(IN6P_RFC2292)) {
1823 					error = EINVAL;
1824 					break;
1825 				}
1826 
1827 				/*
1828 				 * We only ensure valsize is not too large
1829 				 * here.  Further validation will be done
1830 				 * later.
1831 				 */
1832 				error = sooptcopyin(sopt, optbuf_storage,
1833 				    sizeof(optbuf_storage), 0);
1834 				if (error)
1835 					break;
1836 				optlen = sopt->sopt_valsize;
1837 				optbuf = optbuf_storage;
1838 				optp = &in6p->in6p_outputopts;
1839 				error = ip6_pcbopt(optname, optbuf, optlen,
1840 				    optp, (td != NULL) ? td->td_ucred : NULL,
1841 				    uproto);
1842 				break;
1843 			}
1844 #undef OPTSET
1845 
1846 			case IPV6_MULTICAST_IF:
1847 			case IPV6_MULTICAST_HOPS:
1848 			case IPV6_MULTICAST_LOOP:
1849 			case IPV6_JOIN_GROUP:
1850 			case IPV6_LEAVE_GROUP:
1851 			case IPV6_MSFILTER:
1852 			case MCAST_BLOCK_SOURCE:
1853 			case MCAST_UNBLOCK_SOURCE:
1854 			case MCAST_JOIN_GROUP:
1855 			case MCAST_LEAVE_GROUP:
1856 			case MCAST_JOIN_SOURCE_GROUP:
1857 			case MCAST_LEAVE_SOURCE_GROUP:
1858 				error = ip6_setmoptions(in6p, sopt);
1859 				break;
1860 
1861 			case IPV6_PORTRANGE:
1862 				error = sooptcopyin(sopt, &optval,
1863 				    sizeof optval, sizeof optval);
1864 				if (error)
1865 					break;
1866 
1867 				INP_WLOCK(in6p);
1868 				switch (optval) {
1869 				case IPV6_PORTRANGE_DEFAULT:
1870 					in6p->inp_flags &= ~(INP_LOWPORT);
1871 					in6p->inp_flags &= ~(INP_HIGHPORT);
1872 					break;
1873 
1874 				case IPV6_PORTRANGE_HIGH:
1875 					in6p->inp_flags &= ~(INP_LOWPORT);
1876 					in6p->inp_flags |= INP_HIGHPORT;
1877 					break;
1878 
1879 				case IPV6_PORTRANGE_LOW:
1880 					in6p->inp_flags &= ~(INP_HIGHPORT);
1881 					in6p->inp_flags |= INP_LOWPORT;
1882 					break;
1883 
1884 				default:
1885 					error = EINVAL;
1886 					break;
1887 				}
1888 				INP_WUNLOCK(in6p);
1889 				break;
1890 
1891 #ifdef IPSEC
1892 			case IPV6_IPSEC_POLICY:
1893 			{
1894 				caddr_t req;
1895 				struct mbuf *m;
1896 
1897 				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1898 					break;
1899 				if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1900 					break;
1901 				req = mtod(m, caddr_t);
1902 				error = ipsec_set_policy(in6p, optname, req,
1903 				    m->m_len, (sopt->sopt_td != NULL) ?
1904 				    sopt->sopt_td->td_ucred : NULL);
1905 				m_freem(m);
1906 				break;
1907 			}
1908 #endif /* IPSEC */
1909 
1910 			default:
1911 				error = ENOPROTOOPT;
1912 				break;
1913 			}
1914 			break;
1915 
1916 		case SOPT_GET:
1917 			switch (optname) {
1918 
1919 			case IPV6_2292PKTOPTIONS:
1920 #ifdef IPV6_PKTOPTIONS
1921 			case IPV6_PKTOPTIONS:
1922 #endif
1923 				/*
1924 				 * RFC3542 (effectively) deprecated the
1925 				 * semantics of the 2292-style pktoptions.
1926 				 * Since it was not reliable in nature (i.e.,
1927 				 * applications had to expect the lack of some
1928 				 * information after all), it would make sense
1929 				 * to simplify this part by always returning
1930 				 * empty data.
1931 				 */
1932 				sopt->sopt_valsize = 0;
1933 				break;
1934 
1935 			case IPV6_RECVHOPOPTS:
1936 			case IPV6_RECVDSTOPTS:
1937 			case IPV6_RECVRTHDRDSTOPTS:
1938 			case IPV6_UNICAST_HOPS:
1939 			case IPV6_RECVPKTINFO:
1940 			case IPV6_RECVHOPLIMIT:
1941 			case IPV6_RECVRTHDR:
1942 			case IPV6_RECVPATHMTU:
1943 
1944 			case IPV6_FAITH:
1945 			case IPV6_V6ONLY:
1946 			case IPV6_PORTRANGE:
1947 			case IPV6_RECVTCLASS:
1948 			case IPV6_AUTOFLOWLABEL:
1949 			case IPV6_BINDANY:
1950 				switch (optname) {
1951 
1952 				case IPV6_RECVHOPOPTS:
1953 					optval = OPTBIT(IN6P_HOPOPTS);
1954 					break;
1955 
1956 				case IPV6_RECVDSTOPTS:
1957 					optval = OPTBIT(IN6P_DSTOPTS);
1958 					break;
1959 
1960 				case IPV6_RECVRTHDRDSTOPTS:
1961 					optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1962 					break;
1963 
1964 				case IPV6_UNICAST_HOPS:
1965 					optval = in6p->in6p_hops;
1966 					break;
1967 
1968 				case IPV6_RECVPKTINFO:
1969 					optval = OPTBIT(IN6P_PKTINFO);
1970 					break;
1971 
1972 				case IPV6_RECVHOPLIMIT:
1973 					optval = OPTBIT(IN6P_HOPLIMIT);
1974 					break;
1975 
1976 				case IPV6_RECVRTHDR:
1977 					optval = OPTBIT(IN6P_RTHDR);
1978 					break;
1979 
1980 				case IPV6_RECVPATHMTU:
1981 					optval = OPTBIT(IN6P_MTU);
1982 					break;
1983 
1984 				case IPV6_FAITH:
1985 					optval = OPTBIT(INP_FAITH);
1986 					break;
1987 
1988 				case IPV6_V6ONLY:
1989 					optval = OPTBIT(IN6P_IPV6_V6ONLY);
1990 					break;
1991 
1992 				case IPV6_PORTRANGE:
1993 				    {
1994 					int flags;
1995 					flags = in6p->inp_flags;
1996 					if (flags & INP_HIGHPORT)
1997 						optval = IPV6_PORTRANGE_HIGH;
1998 					else if (flags & INP_LOWPORT)
1999 						optval = IPV6_PORTRANGE_LOW;
2000 					else
2001 						optval = 0;
2002 					break;
2003 				    }
2004 				case IPV6_RECVTCLASS:
2005 					optval = OPTBIT(IN6P_TCLASS);
2006 					break;
2007 
2008 				case IPV6_AUTOFLOWLABEL:
2009 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2010 					break;
2011 
2012 				case IPV6_BINDANY:
2013 					optval = OPTBIT(INP_BINDANY);
2014 					break;
2015 				}
2016 				if (error)
2017 					break;
2018 				error = sooptcopyout(sopt, &optval,
2019 					sizeof optval);
2020 				break;
2021 
2022 			case IPV6_PATHMTU:
2023 			{
2024 				u_long pmtu = 0;
2025 				struct ip6_mtuinfo mtuinfo;
2026 				struct route_in6 sro;
2027 
2028 				bzero(&sro, sizeof(sro));
2029 
2030 				if (!(so->so_state & SS_ISCONNECTED))
2031 					return (ENOTCONN);
2032 				/*
2033 				 * XXX: we dot not consider the case of source
2034 				 * routing, or optional information to specify
2035 				 * the outgoing interface.
2036 				 */
2037 				error = ip6_getpmtu(&sro, NULL, NULL,
2038 				    &in6p->in6p_faddr, &pmtu, NULL,
2039 				    so->so_fibnum);
2040 				if (sro.ro_rt)
2041 					RTFREE(sro.ro_rt);
2042 				if (error)
2043 					break;
2044 				if (pmtu > IPV6_MAXPACKET)
2045 					pmtu = IPV6_MAXPACKET;
2046 
2047 				bzero(&mtuinfo, sizeof(mtuinfo));
2048 				mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2049 				optdata = (void *)&mtuinfo;
2050 				optdatalen = sizeof(mtuinfo);
2051 				error = sooptcopyout(sopt, optdata,
2052 				    optdatalen);
2053 				break;
2054 			}
2055 
2056 			case IPV6_2292PKTINFO:
2057 			case IPV6_2292HOPLIMIT:
2058 			case IPV6_2292HOPOPTS:
2059 			case IPV6_2292RTHDR:
2060 			case IPV6_2292DSTOPTS:
2061 				switch (optname) {
2062 				case IPV6_2292PKTINFO:
2063 					optval = OPTBIT(IN6P_PKTINFO);
2064 					break;
2065 				case IPV6_2292HOPLIMIT:
2066 					optval = OPTBIT(IN6P_HOPLIMIT);
2067 					break;
2068 				case IPV6_2292HOPOPTS:
2069 					optval = OPTBIT(IN6P_HOPOPTS);
2070 					break;
2071 				case IPV6_2292RTHDR:
2072 					optval = OPTBIT(IN6P_RTHDR);
2073 					break;
2074 				case IPV6_2292DSTOPTS:
2075 					optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2076 					break;
2077 				}
2078 				error = sooptcopyout(sopt, &optval,
2079 				    sizeof optval);
2080 				break;
2081 			case IPV6_PKTINFO:
2082 			case IPV6_HOPOPTS:
2083 			case IPV6_RTHDR:
2084 			case IPV6_DSTOPTS:
2085 			case IPV6_RTHDRDSTOPTS:
2086 			case IPV6_NEXTHOP:
2087 			case IPV6_TCLASS:
2088 			case IPV6_DONTFRAG:
2089 			case IPV6_USE_MIN_MTU:
2090 			case IPV6_PREFER_TEMPADDR:
2091 				error = ip6_getpcbopt(in6p->in6p_outputopts,
2092 				    optname, sopt);
2093 				break;
2094 
2095 			case IPV6_MULTICAST_IF:
2096 			case IPV6_MULTICAST_HOPS:
2097 			case IPV6_MULTICAST_LOOP:
2098 			case IPV6_MSFILTER:
2099 				error = ip6_getmoptions(in6p, sopt);
2100 				break;
2101 
2102 #ifdef IPSEC
2103 			case IPV6_IPSEC_POLICY:
2104 			  {
2105 				caddr_t req = NULL;
2106 				size_t len = 0;
2107 				struct mbuf *m = NULL;
2108 				struct mbuf **mp = &m;
2109 				size_t ovalsize = sopt->sopt_valsize;
2110 				caddr_t oval = (caddr_t)sopt->sopt_val;
2111 
2112 				error = soopt_getm(sopt, &m); /* XXX */
2113 				if (error != 0)
2114 					break;
2115 				error = soopt_mcopyin(sopt, m); /* XXX */
2116 				if (error != 0)
2117 					break;
2118 				sopt->sopt_valsize = ovalsize;
2119 				sopt->sopt_val = oval;
2120 				if (m) {
2121 					req = mtod(m, caddr_t);
2122 					len = m->m_len;
2123 				}
2124 				error = ipsec_get_policy(in6p, req, len, mp);
2125 				if (error == 0)
2126 					error = soopt_mcopyout(sopt, m); /* XXX */
2127 				if (error == 0 && m)
2128 					m_freem(m);
2129 				break;
2130 			  }
2131 #endif /* IPSEC */
2132 
2133 			default:
2134 				error = ENOPROTOOPT;
2135 				break;
2136 			}
2137 			break;
2138 		}
2139 	}
2140 	return (error);
2141 }
2142 
2143 int
2144 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2145 {
2146 	int error = 0, optval, optlen;
2147 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2148 	struct inpcb *in6p = sotoinpcb(so);
2149 	int level, op, optname;
2150 
2151 	level = sopt->sopt_level;
2152 	op = sopt->sopt_dir;
2153 	optname = sopt->sopt_name;
2154 	optlen = sopt->sopt_valsize;
2155 
2156 	if (level != IPPROTO_IPV6) {
2157 		return (EINVAL);
2158 	}
2159 
2160 	switch (optname) {
2161 	case IPV6_CHECKSUM:
2162 		/*
2163 		 * For ICMPv6 sockets, no modification allowed for checksum
2164 		 * offset, permit "no change" values to help existing apps.
2165 		 *
2166 		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2167 		 * for an ICMPv6 socket will fail."
2168 		 * The current behavior does not meet RFC3542.
2169 		 */
2170 		switch (op) {
2171 		case SOPT_SET:
2172 			if (optlen != sizeof(int)) {
2173 				error = EINVAL;
2174 				break;
2175 			}
2176 			error = sooptcopyin(sopt, &optval, sizeof(optval),
2177 					    sizeof(optval));
2178 			if (error)
2179 				break;
2180 			if ((optval % 2) != 0) {
2181 				/* the API assumes even offset values */
2182 				error = EINVAL;
2183 			} else if (so->so_proto->pr_protocol ==
2184 			    IPPROTO_ICMPV6) {
2185 				if (optval != icmp6off)
2186 					error = EINVAL;
2187 			} else
2188 				in6p->in6p_cksum = optval;
2189 			break;
2190 
2191 		case SOPT_GET:
2192 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2193 				optval = icmp6off;
2194 			else
2195 				optval = in6p->in6p_cksum;
2196 
2197 			error = sooptcopyout(sopt, &optval, sizeof(optval));
2198 			break;
2199 
2200 		default:
2201 			error = EINVAL;
2202 			break;
2203 		}
2204 		break;
2205 
2206 	default:
2207 		error = ENOPROTOOPT;
2208 		break;
2209 	}
2210 
2211 	return (error);
2212 }
2213 
2214 /*
2215  * Set up IP6 options in pcb for insertion in output packets or
2216  * specifying behavior of outgoing packets.
2217  */
2218 static int
2219 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2220     struct socket *so, struct sockopt *sopt)
2221 {
2222 	struct ip6_pktopts *opt = *pktopt;
2223 	int error = 0;
2224 	struct thread *td = sopt->sopt_td;
2225 
2226 	/* turn off any old options. */
2227 	if (opt) {
2228 #ifdef DIAGNOSTIC
2229 		if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2230 		    opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2231 		    opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2232 			printf("ip6_pcbopts: all specified options are cleared.\n");
2233 #endif
2234 		ip6_clearpktopts(opt, -1);
2235 	} else
2236 		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2237 	*pktopt = NULL;
2238 
2239 	if (!m || m->m_len == 0) {
2240 		/*
2241 		 * Only turning off any previous options, regardless of
2242 		 * whether the opt is just created or given.
2243 		 */
2244 		free(opt, M_IP6OPT);
2245 		return (0);
2246 	}
2247 
2248 	/*  set options specified by user. */
2249 	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2250 	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2251 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2252 		free(opt, M_IP6OPT);
2253 		return (error);
2254 	}
2255 	*pktopt = opt;
2256 	return (0);
2257 }
2258 
2259 /*
2260  * initialize ip6_pktopts.  beware that there are non-zero default values in
2261  * the struct.
2262  */
2263 void
2264 ip6_initpktopts(struct ip6_pktopts *opt)
2265 {
2266 
2267 	bzero(opt, sizeof(*opt));
2268 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
2269 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
2270 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2271 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2272 }
2273 
2274 static int
2275 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2276     struct ucred *cred, int uproto)
2277 {
2278 	struct ip6_pktopts *opt;
2279 
2280 	if (*pktopt == NULL) {
2281 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2282 		    M_WAITOK);
2283 		ip6_initpktopts(*pktopt);
2284 	}
2285 	opt = *pktopt;
2286 
2287 	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2288 }
2289 
2290 static int
2291 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2292 {
2293 	void *optdata = NULL;
2294 	int optdatalen = 0;
2295 	struct ip6_ext *ip6e;
2296 	int error = 0;
2297 	struct in6_pktinfo null_pktinfo;
2298 	int deftclass = 0, on;
2299 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
2300 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2301 
2302 	switch (optname) {
2303 	case IPV6_PKTINFO:
2304 		if (pktopt && pktopt->ip6po_pktinfo)
2305 			optdata = (void *)pktopt->ip6po_pktinfo;
2306 		else {
2307 			/* XXX: we don't have to do this every time... */
2308 			bzero(&null_pktinfo, sizeof(null_pktinfo));
2309 			optdata = (void *)&null_pktinfo;
2310 		}
2311 		optdatalen = sizeof(struct in6_pktinfo);
2312 		break;
2313 	case IPV6_TCLASS:
2314 		if (pktopt && pktopt->ip6po_tclass >= 0)
2315 			optdata = (void *)&pktopt->ip6po_tclass;
2316 		else
2317 			optdata = (void *)&deftclass;
2318 		optdatalen = sizeof(int);
2319 		break;
2320 	case IPV6_HOPOPTS:
2321 		if (pktopt && pktopt->ip6po_hbh) {
2322 			optdata = (void *)pktopt->ip6po_hbh;
2323 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2324 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2325 		}
2326 		break;
2327 	case IPV6_RTHDR:
2328 		if (pktopt && pktopt->ip6po_rthdr) {
2329 			optdata = (void *)pktopt->ip6po_rthdr;
2330 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2331 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2332 		}
2333 		break;
2334 	case IPV6_RTHDRDSTOPTS:
2335 		if (pktopt && pktopt->ip6po_dest1) {
2336 			optdata = (void *)pktopt->ip6po_dest1;
2337 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2338 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2339 		}
2340 		break;
2341 	case IPV6_DSTOPTS:
2342 		if (pktopt && pktopt->ip6po_dest2) {
2343 			optdata = (void *)pktopt->ip6po_dest2;
2344 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2345 			optdatalen = (ip6e->ip6e_len + 1) << 3;
2346 		}
2347 		break;
2348 	case IPV6_NEXTHOP:
2349 		if (pktopt && pktopt->ip6po_nexthop) {
2350 			optdata = (void *)pktopt->ip6po_nexthop;
2351 			optdatalen = pktopt->ip6po_nexthop->sa_len;
2352 		}
2353 		break;
2354 	case IPV6_USE_MIN_MTU:
2355 		if (pktopt)
2356 			optdata = (void *)&pktopt->ip6po_minmtu;
2357 		else
2358 			optdata = (void *)&defminmtu;
2359 		optdatalen = sizeof(int);
2360 		break;
2361 	case IPV6_DONTFRAG:
2362 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2363 			on = 1;
2364 		else
2365 			on = 0;
2366 		optdata = (void *)&on;
2367 		optdatalen = sizeof(on);
2368 		break;
2369 	case IPV6_PREFER_TEMPADDR:
2370 		if (pktopt)
2371 			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2372 		else
2373 			optdata = (void *)&defpreftemp;
2374 		optdatalen = sizeof(int);
2375 		break;
2376 	default:		/* should not happen */
2377 #ifdef DIAGNOSTIC
2378 		panic("ip6_getpcbopt: unexpected option\n");
2379 #endif
2380 		return (ENOPROTOOPT);
2381 	}
2382 
2383 	error = sooptcopyout(sopt, optdata, optdatalen);
2384 
2385 	return (error);
2386 }
2387 
2388 void
2389 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2390 {
2391 	if (pktopt == NULL)
2392 		return;
2393 
2394 	if (optname == -1 || optname == IPV6_PKTINFO) {
2395 		if (pktopt->ip6po_pktinfo)
2396 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
2397 		pktopt->ip6po_pktinfo = NULL;
2398 	}
2399 	if (optname == -1 || optname == IPV6_HOPLIMIT)
2400 		pktopt->ip6po_hlim = -1;
2401 	if (optname == -1 || optname == IPV6_TCLASS)
2402 		pktopt->ip6po_tclass = -1;
2403 	if (optname == -1 || optname == IPV6_NEXTHOP) {
2404 		if (pktopt->ip6po_nextroute.ro_rt) {
2405 			RTFREE(pktopt->ip6po_nextroute.ro_rt);
2406 			pktopt->ip6po_nextroute.ro_rt = NULL;
2407 		}
2408 		if (pktopt->ip6po_nexthop)
2409 			free(pktopt->ip6po_nexthop, M_IP6OPT);
2410 		pktopt->ip6po_nexthop = NULL;
2411 	}
2412 	if (optname == -1 || optname == IPV6_HOPOPTS) {
2413 		if (pktopt->ip6po_hbh)
2414 			free(pktopt->ip6po_hbh, M_IP6OPT);
2415 		pktopt->ip6po_hbh = NULL;
2416 	}
2417 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2418 		if (pktopt->ip6po_dest1)
2419 			free(pktopt->ip6po_dest1, M_IP6OPT);
2420 		pktopt->ip6po_dest1 = NULL;
2421 	}
2422 	if (optname == -1 || optname == IPV6_RTHDR) {
2423 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2424 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2425 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2426 		if (pktopt->ip6po_route.ro_rt) {
2427 			RTFREE(pktopt->ip6po_route.ro_rt);
2428 			pktopt->ip6po_route.ro_rt = NULL;
2429 		}
2430 	}
2431 	if (optname == -1 || optname == IPV6_DSTOPTS) {
2432 		if (pktopt->ip6po_dest2)
2433 			free(pktopt->ip6po_dest2, M_IP6OPT);
2434 		pktopt->ip6po_dest2 = NULL;
2435 	}
2436 }
2437 
2438 #define PKTOPT_EXTHDRCPY(type) \
2439 do {\
2440 	if (src->type) {\
2441 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2442 		dst->type = malloc(hlen, M_IP6OPT, canwait);\
2443 		if (dst->type == NULL && canwait == M_NOWAIT)\
2444 			goto bad;\
2445 		bcopy(src->type, dst->type, hlen);\
2446 	}\
2447 } while (/*CONSTCOND*/ 0)
2448 
2449 static int
2450 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2451 {
2452 	if (dst == NULL || src == NULL)  {
2453 		printf("ip6_clearpktopts: invalid argument\n");
2454 		return (EINVAL);
2455 	}
2456 
2457 	dst->ip6po_hlim = src->ip6po_hlim;
2458 	dst->ip6po_tclass = src->ip6po_tclass;
2459 	dst->ip6po_flags = src->ip6po_flags;
2460 	dst->ip6po_minmtu = src->ip6po_minmtu;
2461 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2462 	if (src->ip6po_pktinfo) {
2463 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2464 		    M_IP6OPT, canwait);
2465 		if (dst->ip6po_pktinfo == NULL)
2466 			goto bad;
2467 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2468 	}
2469 	if (src->ip6po_nexthop) {
2470 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2471 		    M_IP6OPT, canwait);
2472 		if (dst->ip6po_nexthop == NULL)
2473 			goto bad;
2474 		bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2475 		    src->ip6po_nexthop->sa_len);
2476 	}
2477 	PKTOPT_EXTHDRCPY(ip6po_hbh);
2478 	PKTOPT_EXTHDRCPY(ip6po_dest1);
2479 	PKTOPT_EXTHDRCPY(ip6po_dest2);
2480 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2481 	return (0);
2482 
2483   bad:
2484 	ip6_clearpktopts(dst, -1);
2485 	return (ENOBUFS);
2486 }
2487 #undef PKTOPT_EXTHDRCPY
2488 
2489 struct ip6_pktopts *
2490 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2491 {
2492 	int error;
2493 	struct ip6_pktopts *dst;
2494 
2495 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2496 	if (dst == NULL)
2497 		return (NULL);
2498 	ip6_initpktopts(dst);
2499 
2500 	if ((error = copypktopts(dst, src, canwait)) != 0) {
2501 		free(dst, M_IP6OPT);
2502 		return (NULL);
2503 	}
2504 
2505 	return (dst);
2506 }
2507 
2508 void
2509 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2510 {
2511 	if (pktopt == NULL)
2512 		return;
2513 
2514 	ip6_clearpktopts(pktopt, -1);
2515 
2516 	free(pktopt, M_IP6OPT);
2517 }
2518 
2519 /*
2520  * Set IPv6 outgoing packet options based on advanced API.
2521  */
2522 int
2523 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2524     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2525 {
2526 	struct cmsghdr *cm = 0;
2527 
2528 	if (control == NULL || opt == NULL)
2529 		return (EINVAL);
2530 
2531 	ip6_initpktopts(opt);
2532 	if (stickyopt) {
2533 		int error;
2534 
2535 		/*
2536 		 * If stickyopt is provided, make a local copy of the options
2537 		 * for this particular packet, then override them by ancillary
2538 		 * objects.
2539 		 * XXX: copypktopts() does not copy the cached route to a next
2540 		 * hop (if any).  This is not very good in terms of efficiency,
2541 		 * but we can allow this since this option should be rarely
2542 		 * used.
2543 		 */
2544 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2545 			return (error);
2546 	}
2547 
2548 	/*
2549 	 * XXX: Currently, we assume all the optional information is stored
2550 	 * in a single mbuf.
2551 	 */
2552 	if (control->m_next)
2553 		return (EINVAL);
2554 
2555 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2556 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2557 		int error;
2558 
2559 		if (control->m_len < CMSG_LEN(0))
2560 			return (EINVAL);
2561 
2562 		cm = mtod(control, struct cmsghdr *);
2563 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2564 			return (EINVAL);
2565 		if (cm->cmsg_level != IPPROTO_IPV6)
2566 			continue;
2567 
2568 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2569 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2570 		if (error)
2571 			return (error);
2572 	}
2573 
2574 	return (0);
2575 }
2576 
2577 /*
2578  * Set a particular packet option, as a sticky option or an ancillary data
2579  * item.  "len" can be 0 only when it's a sticky option.
2580  * We have 4 cases of combination of "sticky" and "cmsg":
2581  * "sticky=0, cmsg=0": impossible
2582  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2583  * "sticky=1, cmsg=0": RFC3542 socket option
2584  * "sticky=1, cmsg=1": RFC2292 socket option
2585  */
2586 static int
2587 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2588     struct ucred *cred, int sticky, int cmsg, int uproto)
2589 {
2590 	int minmtupolicy, preftemp;
2591 	int error;
2592 
2593 	if (!sticky && !cmsg) {
2594 #ifdef DIAGNOSTIC
2595 		printf("ip6_setpktopt: impossible case\n");
2596 #endif
2597 		return (EINVAL);
2598 	}
2599 
2600 	/*
2601 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2602 	 * not be specified in the context of RFC3542.  Conversely,
2603 	 * RFC3542 types should not be specified in the context of RFC2292.
2604 	 */
2605 	if (!cmsg) {
2606 		switch (optname) {
2607 		case IPV6_2292PKTINFO:
2608 		case IPV6_2292HOPLIMIT:
2609 		case IPV6_2292NEXTHOP:
2610 		case IPV6_2292HOPOPTS:
2611 		case IPV6_2292DSTOPTS:
2612 		case IPV6_2292RTHDR:
2613 		case IPV6_2292PKTOPTIONS:
2614 			return (ENOPROTOOPT);
2615 		}
2616 	}
2617 	if (sticky && cmsg) {
2618 		switch (optname) {
2619 		case IPV6_PKTINFO:
2620 		case IPV6_HOPLIMIT:
2621 		case IPV6_NEXTHOP:
2622 		case IPV6_HOPOPTS:
2623 		case IPV6_DSTOPTS:
2624 		case IPV6_RTHDRDSTOPTS:
2625 		case IPV6_RTHDR:
2626 		case IPV6_USE_MIN_MTU:
2627 		case IPV6_DONTFRAG:
2628 		case IPV6_TCLASS:
2629 		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2630 			return (ENOPROTOOPT);
2631 		}
2632 	}
2633 
2634 	switch (optname) {
2635 	case IPV6_2292PKTINFO:
2636 	case IPV6_PKTINFO:
2637 	{
2638 		struct ifnet *ifp = NULL;
2639 		struct in6_pktinfo *pktinfo;
2640 
2641 		if (len != sizeof(struct in6_pktinfo))
2642 			return (EINVAL);
2643 
2644 		pktinfo = (struct in6_pktinfo *)buf;
2645 
2646 		/*
2647 		 * An application can clear any sticky IPV6_PKTINFO option by
2648 		 * doing a "regular" setsockopt with ipi6_addr being
2649 		 * in6addr_any and ipi6_ifindex being zero.
2650 		 * [RFC 3542, Section 6]
2651 		 */
2652 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2653 		    pktinfo->ipi6_ifindex == 0 &&
2654 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2655 			ip6_clearpktopts(opt, optname);
2656 			break;
2657 		}
2658 
2659 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2660 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2661 			return (EINVAL);
2662 		}
2663 
2664 		/* validate the interface index if specified. */
2665 		if (pktinfo->ipi6_ifindex > V_if_index)
2666 			 return (ENXIO);
2667 		if (pktinfo->ipi6_ifindex) {
2668 			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2669 			if (ifp == NULL)
2670 				return (ENXIO);
2671 		}
2672 
2673 		/*
2674 		 * We store the address anyway, and let in6_selectsrc()
2675 		 * validate the specified address.  This is because ipi6_addr
2676 		 * may not have enough information about its scope zone, and
2677 		 * we may need additional information (such as outgoing
2678 		 * interface or the scope zone of a destination address) to
2679 		 * disambiguate the scope.
2680 		 * XXX: the delay of the validation may confuse the
2681 		 * application when it is used as a sticky option.
2682 		 */
2683 		if (opt->ip6po_pktinfo == NULL) {
2684 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2685 			    M_IP6OPT, M_NOWAIT);
2686 			if (opt->ip6po_pktinfo == NULL)
2687 				return (ENOBUFS);
2688 		}
2689 		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2690 		break;
2691 	}
2692 
2693 	case IPV6_2292HOPLIMIT:
2694 	case IPV6_HOPLIMIT:
2695 	{
2696 		int *hlimp;
2697 
2698 		/*
2699 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2700 		 * to simplify the ordering among hoplimit options.
2701 		 */
2702 		if (optname == IPV6_HOPLIMIT && sticky)
2703 			return (ENOPROTOOPT);
2704 
2705 		if (len != sizeof(int))
2706 			return (EINVAL);
2707 		hlimp = (int *)buf;
2708 		if (*hlimp < -1 || *hlimp > 255)
2709 			return (EINVAL);
2710 
2711 		opt->ip6po_hlim = *hlimp;
2712 		break;
2713 	}
2714 
2715 	case IPV6_TCLASS:
2716 	{
2717 		int tclass;
2718 
2719 		if (len != sizeof(int))
2720 			return (EINVAL);
2721 		tclass = *(int *)buf;
2722 		if (tclass < -1 || tclass > 255)
2723 			return (EINVAL);
2724 
2725 		opt->ip6po_tclass = tclass;
2726 		break;
2727 	}
2728 
2729 	case IPV6_2292NEXTHOP:
2730 	case IPV6_NEXTHOP:
2731 		if (cred != NULL) {
2732 			error = priv_check_cred(cred,
2733 			    PRIV_NETINET_SETHDROPTS, 0);
2734 			if (error)
2735 				return (error);
2736 		}
2737 
2738 		if (len == 0) {	/* just remove the option */
2739 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
2740 			break;
2741 		}
2742 
2743 		/* check if cmsg_len is large enough for sa_len */
2744 		if (len < sizeof(struct sockaddr) || len < *buf)
2745 			return (EINVAL);
2746 
2747 		switch (((struct sockaddr *)buf)->sa_family) {
2748 		case AF_INET6:
2749 		{
2750 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2751 			int error;
2752 
2753 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2754 				return (EINVAL);
2755 
2756 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2757 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2758 				return (EINVAL);
2759 			}
2760 			if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2761 			    != 0) {
2762 				return (error);
2763 			}
2764 			break;
2765 		}
2766 		case AF_LINK:	/* should eventually be supported */
2767 		default:
2768 			return (EAFNOSUPPORT);
2769 		}
2770 
2771 		/* turn off the previous option, then set the new option. */
2772 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
2773 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2774 		if (opt->ip6po_nexthop == NULL)
2775 			return (ENOBUFS);
2776 		bcopy(buf, opt->ip6po_nexthop, *buf);
2777 		break;
2778 
2779 	case IPV6_2292HOPOPTS:
2780 	case IPV6_HOPOPTS:
2781 	{
2782 		struct ip6_hbh *hbh;
2783 		int hbhlen;
2784 
2785 		/*
2786 		 * XXX: We don't allow a non-privileged user to set ANY HbH
2787 		 * options, since per-option restriction has too much
2788 		 * overhead.
2789 		 */
2790 		if (cred != NULL) {
2791 			error = priv_check_cred(cred,
2792 			    PRIV_NETINET_SETHDROPTS, 0);
2793 			if (error)
2794 				return (error);
2795 		}
2796 
2797 		if (len == 0) {
2798 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
2799 			break;	/* just remove the option */
2800 		}
2801 
2802 		/* message length validation */
2803 		if (len < sizeof(struct ip6_hbh))
2804 			return (EINVAL);
2805 		hbh = (struct ip6_hbh *)buf;
2806 		hbhlen = (hbh->ip6h_len + 1) << 3;
2807 		if (len != hbhlen)
2808 			return (EINVAL);
2809 
2810 		/* turn off the previous option, then set the new option. */
2811 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
2812 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2813 		if (opt->ip6po_hbh == NULL)
2814 			return (ENOBUFS);
2815 		bcopy(hbh, opt->ip6po_hbh, hbhlen);
2816 
2817 		break;
2818 	}
2819 
2820 	case IPV6_2292DSTOPTS:
2821 	case IPV6_DSTOPTS:
2822 	case IPV6_RTHDRDSTOPTS:
2823 	{
2824 		struct ip6_dest *dest, **newdest = NULL;
2825 		int destlen;
2826 
2827 		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2828 			error = priv_check_cred(cred,
2829 			    PRIV_NETINET_SETHDROPTS, 0);
2830 			if (error)
2831 				return (error);
2832 		}
2833 
2834 		if (len == 0) {
2835 			ip6_clearpktopts(opt, optname);
2836 			break;	/* just remove the option */
2837 		}
2838 
2839 		/* message length validation */
2840 		if (len < sizeof(struct ip6_dest))
2841 			return (EINVAL);
2842 		dest = (struct ip6_dest *)buf;
2843 		destlen = (dest->ip6d_len + 1) << 3;
2844 		if (len != destlen)
2845 			return (EINVAL);
2846 
2847 		/*
2848 		 * Determine the position that the destination options header
2849 		 * should be inserted; before or after the routing header.
2850 		 */
2851 		switch (optname) {
2852 		case IPV6_2292DSTOPTS:
2853 			/*
2854 			 * The old advacned API is ambiguous on this point.
2855 			 * Our approach is to determine the position based
2856 			 * according to the existence of a routing header.
2857 			 * Note, however, that this depends on the order of the
2858 			 * extension headers in the ancillary data; the 1st
2859 			 * part of the destination options header must appear
2860 			 * before the routing header in the ancillary data,
2861 			 * too.
2862 			 * RFC3542 solved the ambiguity by introducing
2863 			 * separate ancillary data or option types.
2864 			 */
2865 			if (opt->ip6po_rthdr == NULL)
2866 				newdest = &opt->ip6po_dest1;
2867 			else
2868 				newdest = &opt->ip6po_dest2;
2869 			break;
2870 		case IPV6_RTHDRDSTOPTS:
2871 			newdest = &opt->ip6po_dest1;
2872 			break;
2873 		case IPV6_DSTOPTS:
2874 			newdest = &opt->ip6po_dest2;
2875 			break;
2876 		}
2877 
2878 		/* turn off the previous option, then set the new option. */
2879 		ip6_clearpktopts(opt, optname);
2880 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2881 		if (*newdest == NULL)
2882 			return (ENOBUFS);
2883 		bcopy(dest, *newdest, destlen);
2884 
2885 		break;
2886 	}
2887 
2888 	case IPV6_2292RTHDR:
2889 	case IPV6_RTHDR:
2890 	{
2891 		struct ip6_rthdr *rth;
2892 		int rthlen;
2893 
2894 		if (len == 0) {
2895 			ip6_clearpktopts(opt, IPV6_RTHDR);
2896 			break;	/* just remove the option */
2897 		}
2898 
2899 		/* message length validation */
2900 		if (len < sizeof(struct ip6_rthdr))
2901 			return (EINVAL);
2902 		rth = (struct ip6_rthdr *)buf;
2903 		rthlen = (rth->ip6r_len + 1) << 3;
2904 		if (len != rthlen)
2905 			return (EINVAL);
2906 
2907 		switch (rth->ip6r_type) {
2908 		case IPV6_RTHDR_TYPE_0:
2909 			if (rth->ip6r_len == 0)	/* must contain one addr */
2910 				return (EINVAL);
2911 			if (rth->ip6r_len % 2) /* length must be even */
2912 				return (EINVAL);
2913 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2914 				return (EINVAL);
2915 			break;
2916 		default:
2917 			return (EINVAL);	/* not supported */
2918 		}
2919 
2920 		/* turn off the previous option */
2921 		ip6_clearpktopts(opt, IPV6_RTHDR);
2922 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2923 		if (opt->ip6po_rthdr == NULL)
2924 			return (ENOBUFS);
2925 		bcopy(rth, opt->ip6po_rthdr, rthlen);
2926 
2927 		break;
2928 	}
2929 
2930 	case IPV6_USE_MIN_MTU:
2931 		if (len != sizeof(int))
2932 			return (EINVAL);
2933 		minmtupolicy = *(int *)buf;
2934 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2935 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
2936 		    minmtupolicy != IP6PO_MINMTU_ALL) {
2937 			return (EINVAL);
2938 		}
2939 		opt->ip6po_minmtu = minmtupolicy;
2940 		break;
2941 
2942 	case IPV6_DONTFRAG:
2943 		if (len != sizeof(int))
2944 			return (EINVAL);
2945 
2946 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2947 			/*
2948 			 * we ignore this option for TCP sockets.
2949 			 * (RFC3542 leaves this case unspecified.)
2950 			 */
2951 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2952 		} else
2953 			opt->ip6po_flags |= IP6PO_DONTFRAG;
2954 		break;
2955 
2956 	case IPV6_PREFER_TEMPADDR:
2957 		if (len != sizeof(int))
2958 			return (EINVAL);
2959 		preftemp = *(int *)buf;
2960 		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2961 		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2962 		    preftemp != IP6PO_TEMPADDR_PREFER) {
2963 			return (EINVAL);
2964 		}
2965 		opt->ip6po_prefer_tempaddr = preftemp;
2966 		break;
2967 
2968 	default:
2969 		return (ENOPROTOOPT);
2970 	} /* end of switch */
2971 
2972 	return (0);
2973 }
2974 
2975 /*
2976  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2977  * packet to the input queue of a specified interface.  Note that this
2978  * calls the output routine of the loopback "driver", but with an interface
2979  * pointer that might NOT be &loif -- easier than replicating that code here.
2980  */
2981 void
2982 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2983 {
2984 	struct mbuf *copym;
2985 	struct ip6_hdr *ip6;
2986 
2987 	copym = m_copy(m, 0, M_COPYALL);
2988 	if (copym == NULL)
2989 		return;
2990 
2991 	/*
2992 	 * Make sure to deep-copy IPv6 header portion in case the data
2993 	 * is in an mbuf cluster, so that we can safely override the IPv6
2994 	 * header portion later.
2995 	 */
2996 	if ((copym->m_flags & M_EXT) != 0 ||
2997 	    copym->m_len < sizeof(struct ip6_hdr)) {
2998 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
2999 		if (copym == NULL)
3000 			return;
3001 	}
3002 
3003 #ifdef DIAGNOSTIC
3004 	if (copym->m_len < sizeof(*ip6)) {
3005 		m_freem(copym);
3006 		return;
3007 	}
3008 #endif
3009 
3010 	ip6 = mtod(copym, struct ip6_hdr *);
3011 	/*
3012 	 * clear embedded scope identifiers if necessary.
3013 	 * in6_clearscope will touch the addresses only when necessary.
3014 	 */
3015 	in6_clearscope(&ip6->ip6_src);
3016 	in6_clearscope(&ip6->ip6_dst);
3017 
3018 	(void)if_simloop(ifp, copym, dst->sin6_family, 0);
3019 }
3020 
3021 /*
3022  * Chop IPv6 header off from the payload.
3023  */
3024 static int
3025 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3026 {
3027 	struct mbuf *mh;
3028 	struct ip6_hdr *ip6;
3029 
3030 	ip6 = mtod(m, struct ip6_hdr *);
3031 	if (m->m_len > sizeof(*ip6)) {
3032 		mh = m_gethdr(M_NOWAIT, MT_DATA);
3033 		if (mh == NULL) {
3034 			m_freem(m);
3035 			return ENOBUFS;
3036 		}
3037 		m_move_pkthdr(mh, m);
3038 		MH_ALIGN(mh, sizeof(*ip6));
3039 		m->m_len -= sizeof(*ip6);
3040 		m->m_data += sizeof(*ip6);
3041 		mh->m_next = m;
3042 		m = mh;
3043 		m->m_len = sizeof(*ip6);
3044 		bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3045 	}
3046 	exthdrs->ip6e_ip6 = m;
3047 	return 0;
3048 }
3049 
3050 /*
3051  * Compute IPv6 extension header length.
3052  */
3053 int
3054 ip6_optlen(struct inpcb *in6p)
3055 {
3056 	int len;
3057 
3058 	if (!in6p->in6p_outputopts)
3059 		return 0;
3060 
3061 	len = 0;
3062 #define elen(x) \
3063     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3064 
3065 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
3066 	if (in6p->in6p_outputopts->ip6po_rthdr)
3067 		/* dest1 is valid with rthdr only */
3068 		len += elen(in6p->in6p_outputopts->ip6po_dest1);
3069 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3070 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
3071 	return len;
3072 #undef elen
3073 }
3074