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ip6_output.c revision 1.146
      1 /*	$NetBSD: ip6_output.c,v 1.146 2012/03/13 18:40:59 elad Exp $	*/
      2 /*	$KAME: ip6_output.c,v 1.172 2001/03/25 09:55:56 itojun Exp $	*/
      3 
      4 /*
      5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of the project nor the names of its contributors
     17  *    may be used to endorse or promote products derived from this software
     18  *    without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
     21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
     24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     30  * SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * Copyright (c) 1982, 1986, 1988, 1990, 1993
     35  *	The Regents of the University of California.  All rights reserved.
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. Redistributions in binary form must reproduce the above copyright
     43  *    notice, this list of conditions and the following disclaimer in the
     44  *    documentation and/or other materials provided with the distribution.
     45  * 3. Neither the name of the University nor the names of its contributors
     46  *    may be used to endorse or promote products derived from this software
     47  *    without specific prior written permission.
     48  *
     49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     59  * SUCH DAMAGE.
     60  *
     61  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
     62  */
     63 
     64 #include <sys/cdefs.h>
     65 __KERNEL_RCSID(0, "$NetBSD: ip6_output.c,v 1.146 2012/03/13 18:40:59 elad Exp $");
     66 
     67 #include "opt_inet.h"
     68 #include "opt_inet6.h"
     69 #include "opt_ipsec.h"
     70 #include "opt_pfil_hooks.h"
     71 
     72 #include <sys/param.h>
     73 #include <sys/malloc.h>
     74 #include <sys/mbuf.h>
     75 #include <sys/errno.h>
     76 #include <sys/protosw.h>
     77 #include <sys/socket.h>
     78 #include <sys/socketvar.h>
     79 #include <sys/systm.h>
     80 #include <sys/proc.h>
     81 #include <sys/kauth.h>
     82 
     83 #include <net/if.h>
     84 #include <net/route.h>
     85 #ifdef PFIL_HOOKS
     86 #include <net/pfil.h>
     87 #endif
     88 
     89 #include <netinet/in.h>
     90 #include <netinet/in_var.h>
     91 #include <netinet/ip6.h>
     92 #include <netinet/icmp6.h>
     93 #include <netinet/in_offload.h>
     94 #include <netinet6/in6_offload.h>
     95 #include <netinet6/ip6_var.h>
     96 #include <netinet6/ip6_private.h>
     97 #include <netinet6/in6_pcb.h>
     98 #include <netinet6/nd6.h>
     99 #include <netinet6/ip6protosw.h>
    100 #include <netinet6/scope6_var.h>
    101 
    102 #ifdef KAME_IPSEC
    103 #include <netinet6/ipsec.h>
    104 #include <netinet6/ipsec_private.h>
    105 #include <netkey/key.h>
    106 #endif /* KAME_IPSEC */
    107 
    108 #ifdef FAST_IPSEC
    109 #include <netipsec/ipsec.h>
    110 #include <netipsec/ipsec6.h>
    111 #include <netipsec/key.h>
    112 #include <netipsec/xform.h>
    113 #endif
    114 
    115 
    116 #include <net/net_osdep.h>
    117 
    118 #ifdef PFIL_HOOKS
    119 extern struct pfil_head inet6_pfil_hook;	/* XXX */
    120 #endif
    121 
    122 struct ip6_exthdrs {
    123 	struct mbuf *ip6e_ip6;
    124 	struct mbuf *ip6e_hbh;
    125 	struct mbuf *ip6e_dest1;
    126 	struct mbuf *ip6e_rthdr;
    127 	struct mbuf *ip6e_dest2;
    128 };
    129 
    130 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
    131 	kauth_cred_t, int);
    132 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
    133 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *, kauth_cred_t,
    134 	int, int, int);
    135 static int ip6_setmoptions(const struct sockopt *, struct ip6_moptions **);
    136 static int ip6_getmoptions(struct sockopt *, struct ip6_moptions *);
    137 static int ip6_copyexthdr(struct mbuf **, void *, int);
    138 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
    139 	struct ip6_frag **);
    140 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
    141 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
    142 static int ip6_getpmtu(struct route *, struct route *, struct ifnet *,
    143     const struct in6_addr *, u_long *, int *);
    144 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
    145 
    146 #ifdef RFC2292
    147 static int ip6_pcbopts(struct ip6_pktopts **, struct socket *, struct sockopt *);
    148 #endif
    149 
    150 /*
    151  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
    152  * header (with pri, len, nxt, hlim, src, dst).
    153  * This function may modify ver and hlim only.
    154  * The mbuf chain containing the packet will be freed.
    155  * The mbuf opt, if present, will not be freed.
    156  *
    157  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
    158  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
    159  * which is rt_rmx.rmx_mtu.
    160  */
    161 int
    162 ip6_output(
    163     struct mbuf *m0,
    164     struct ip6_pktopts *opt,
    165     struct route *ro,
    166     int flags,
    167     struct ip6_moptions *im6o,
    168     struct socket *so,
    169     struct ifnet **ifpp		/* XXX: just for statistics */
    170 )
    171 {
    172 	struct ip6_hdr *ip6, *mhip6;
    173 	struct ifnet *ifp, *origifp;
    174 	struct mbuf *m = m0;
    175 	int hlen, tlen, len, off;
    176 	bool tso;
    177 	struct route ip6route;
    178 	struct rtentry *rt = NULL;
    179 	const struct sockaddr_in6 *dst = NULL;
    180 	struct sockaddr_in6 src_sa, dst_sa;
    181 	int error = 0;
    182 	struct in6_ifaddr *ia = NULL;
    183 	u_long mtu;
    184 	int alwaysfrag, dontfrag;
    185 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
    186 	struct ip6_exthdrs exthdrs;
    187 	struct in6_addr finaldst, src0, dst0;
    188 	u_int32_t zone;
    189 	struct route *ro_pmtu = NULL;
    190 	int hdrsplit = 0;
    191 	int needipsec = 0;
    192 #ifdef KAME_IPSEC
    193 	int needipsectun = 0;
    194 	struct secpolicy *sp = NULL;
    195 
    196 	ip6 = mtod(m, struct ip6_hdr *);
    197 #endif /* KAME_IPSEC */
    198 #ifdef FAST_IPSEC
    199 	struct secpolicy *sp = NULL;
    200 	int s;
    201 #endif
    202 
    203 	memset(&ip6route, 0, sizeof(ip6route));
    204 
    205 #ifdef  DIAGNOSTIC
    206 	if ((m->m_flags & M_PKTHDR) == 0)
    207 		panic("ip6_output: no HDR");
    208 
    209 	if ((m->m_pkthdr.csum_flags &
    210 	    (M_CSUM_TCPv4|M_CSUM_UDPv4|M_CSUM_TSOv4)) != 0) {
    211 		panic("ip6_output: IPv4 checksum offload flags: %d",
    212 		    m->m_pkthdr.csum_flags);
    213 	}
    214 
    215 	if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) ==
    216 	    (M_CSUM_TCPv6|M_CSUM_UDPv6)) {
    217 		panic("ip6_output: conflicting checksum offload flags: %d",
    218 		    m->m_pkthdr.csum_flags);
    219 	}
    220 #endif
    221 
    222 	M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data, sizeof(struct ip6_hdr));
    223 
    224 #define MAKE_EXTHDR(hp, mp)						\
    225     do {								\
    226 	if (hp) {							\
    227 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
    228 		error = ip6_copyexthdr((mp), (void *)(hp), 		\
    229 		    ((eh)->ip6e_len + 1) << 3);				\
    230 		if (error)						\
    231 			goto freehdrs;					\
    232 	}								\
    233     } while (/*CONSTCOND*/ 0)
    234 
    235 	memset(&exthdrs, 0, sizeof(exthdrs));
    236 	if (opt) {
    237 		/* Hop-by-Hop options header */
    238 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
    239 		/* Destination options header(1st part) */
    240 		MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
    241 		/* Routing header */
    242 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
    243 		/* Destination options header(2nd part) */
    244 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
    245 	}
    246 
    247 #ifdef KAME_IPSEC
    248 	if ((flags & IPV6_FORWARDING) != 0) {
    249 		needipsec = 0;
    250 		goto skippolicycheck;
    251 	}
    252 
    253 	/* get a security policy for this packet */
    254 	if (so == NULL)
    255 		sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
    256 	else {
    257 		if (IPSEC_PCB_SKIP_IPSEC(sotoinpcb_hdr(so)->inph_sp,
    258 					 IPSEC_DIR_OUTBOUND)) {
    259 			needipsec = 0;
    260 			goto skippolicycheck;
    261 		}
    262 		sp = ipsec6_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
    263 	}
    264 
    265 	if (sp == NULL) {
    266 		IPSEC6_STATINC(IPSEC_STAT_OUT_INVAL);
    267 		goto freehdrs;
    268 	}
    269 
    270 	error = 0;
    271 
    272 	/* check policy */
    273 	switch (sp->policy) {
    274 	case IPSEC_POLICY_DISCARD:
    275 		/*
    276 		 * This packet is just discarded.
    277 		 */
    278 		IPSEC6_STATINC(IPSEC_STAT_OUT_POLVIO);
    279 		goto freehdrs;
    280 
    281 	case IPSEC_POLICY_BYPASS:
    282 	case IPSEC_POLICY_NONE:
    283 		/* no need to do IPsec. */
    284 		needipsec = 0;
    285 		break;
    286 
    287 	case IPSEC_POLICY_IPSEC:
    288 		if (sp->req == NULL) {
    289 			/* XXX should be panic ? */
    290 			printf("ip6_output: No IPsec request specified.\n");
    291 			error = EINVAL;
    292 			goto freehdrs;
    293 		}
    294 		needipsec = 1;
    295 		break;
    296 
    297 	case IPSEC_POLICY_ENTRUST:
    298 	default:
    299 		printf("ip6_output: Invalid policy found. %d\n", sp->policy);
    300 	}
    301 
    302   skippolicycheck:;
    303 #endif /* KAME_IPSEC */
    304 
    305 	/*
    306 	 * Calculate the total length of the extension header chain.
    307 	 * Keep the length of the unfragmentable part for fragmentation.
    308 	 */
    309 	optlen = 0;
    310 	if (exthdrs.ip6e_hbh) optlen += exthdrs.ip6e_hbh->m_len;
    311 	if (exthdrs.ip6e_dest1) optlen += exthdrs.ip6e_dest1->m_len;
    312 	if (exthdrs.ip6e_rthdr) optlen += exthdrs.ip6e_rthdr->m_len;
    313 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
    314 	/* NOTE: we don't add AH/ESP length here. do that later. */
    315 	if (exthdrs.ip6e_dest2) optlen += exthdrs.ip6e_dest2->m_len;
    316 
    317 #ifdef FAST_IPSEC
    318 	/* Check the security policy (SP) for the packet */
    319 
    320 	sp = ipsec6_check_policy(m,so,flags,&needipsec,&error);
    321 	if (error != 0) {
    322 		/*
    323 		 * Hack: -EINVAL is used to signal that a packet
    324 		 * should be silently discarded.  This is typically
    325 		 * because we asked key management for an SA and
    326 		 * it was delayed (e.g. kicked up to IKE).
    327 		 */
    328 	if (error == -EINVAL)
    329 		error = 0;
    330 	goto freehdrs;
    331     }
    332 #endif /* FAST_IPSEC */
    333 
    334 
    335 	if (needipsec &&
    336 	    (m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    337 		in6_delayed_cksum(m);
    338 		m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    339 	}
    340 
    341 
    342 	/*
    343 	 * If we need IPsec, or there is at least one extension header,
    344 	 * separate IP6 header from the payload.
    345 	 */
    346 	if ((needipsec || optlen) && !hdrsplit) {
    347 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    348 			m = NULL;
    349 			goto freehdrs;
    350 		}
    351 		m = exthdrs.ip6e_ip6;
    352 		hdrsplit++;
    353 	}
    354 
    355 	/* adjust pointer */
    356 	ip6 = mtod(m, struct ip6_hdr *);
    357 
    358 	/* adjust mbuf packet header length */
    359 	m->m_pkthdr.len += optlen;
    360 	plen = m->m_pkthdr.len - sizeof(*ip6);
    361 
    362 	/* If this is a jumbo payload, insert a jumbo payload option. */
    363 	if (plen > IPV6_MAXPACKET) {
    364 		if (!hdrsplit) {
    365 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    366 				m = NULL;
    367 				goto freehdrs;
    368 			}
    369 			m = exthdrs.ip6e_ip6;
    370 			hdrsplit++;
    371 		}
    372 		/* adjust pointer */
    373 		ip6 = mtod(m, struct ip6_hdr *);
    374 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
    375 			goto freehdrs;
    376 		optlen += 8; /* XXX JUMBOOPTLEN */
    377 		ip6->ip6_plen = 0;
    378 	} else
    379 		ip6->ip6_plen = htons(plen);
    380 
    381 	/*
    382 	 * Concatenate headers and fill in next header fields.
    383 	 * Here we have, on "m"
    384 	 *	IPv6 payload
    385 	 * and we insert headers accordingly.  Finally, we should be getting:
    386 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
    387 	 *
    388 	 * during the header composing process, "m" points to IPv6 header.
    389 	 * "mprev" points to an extension header prior to esp.
    390 	 */
    391 	{
    392 		u_char *nexthdrp = &ip6->ip6_nxt;
    393 		struct mbuf *mprev = m;
    394 
    395 		/*
    396 		 * we treat dest2 specially.  this makes IPsec processing
    397 		 * much easier.  the goal here is to make mprev point the
    398 		 * mbuf prior to dest2.
    399 		 *
    400 		 * result: IPv6 dest2 payload
    401 		 * m and mprev will point to IPv6 header.
    402 		 */
    403 		if (exthdrs.ip6e_dest2) {
    404 			if (!hdrsplit)
    405 				panic("assumption failed: hdr not split");
    406 			exthdrs.ip6e_dest2->m_next = m->m_next;
    407 			m->m_next = exthdrs.ip6e_dest2;
    408 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
    409 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
    410 		}
    411 
    412 #define MAKE_CHAIN(m, mp, p, i)\
    413     do {\
    414 	if (m) {\
    415 		if (!hdrsplit) \
    416 			panic("assumption failed: hdr not split"); \
    417 		*mtod((m), u_char *) = *(p);\
    418 		*(p) = (i);\
    419 		p = mtod((m), u_char *);\
    420 		(m)->m_next = (mp)->m_next;\
    421 		(mp)->m_next = (m);\
    422 		(mp) = (m);\
    423 	}\
    424     } while (/*CONSTCOND*/ 0)
    425 		/*
    426 		 * result: IPv6 hbh dest1 rthdr dest2 payload
    427 		 * m will point to IPv6 header.  mprev will point to the
    428 		 * extension header prior to dest2 (rthdr in the above case).
    429 		 */
    430 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
    431 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
    432 		    IPPROTO_DSTOPTS);
    433 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
    434 		    IPPROTO_ROUTING);
    435 
    436 		M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data,
    437 		    sizeof(struct ip6_hdr) + optlen);
    438 
    439 #ifdef KAME_IPSEC
    440 		if (!needipsec)
    441 			goto skip_ipsec2;
    442 
    443 		/*
    444 		 * pointers after IPsec headers are not valid any more.
    445 		 * other pointers need a great care too.
    446 		 * (IPsec routines should not mangle mbufs prior to AH/ESP)
    447 		 */
    448 		exthdrs.ip6e_dest2 = NULL;
    449 
    450 	    {
    451 		struct ip6_rthdr *rh = NULL;
    452 		int segleft_org = 0;
    453 		struct ipsec_output_state state;
    454 
    455 		if (exthdrs.ip6e_rthdr) {
    456 			rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
    457 			segleft_org = rh->ip6r_segleft;
    458 			rh->ip6r_segleft = 0;
    459 		}
    460 
    461 		memset(&state, 0, sizeof(state));
    462 		state.m = m;
    463 		error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
    464 		    &needipsectun);
    465 		m = state.m;
    466 		if (error) {
    467 			rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
    468 			/* mbuf is already reclaimed in ipsec6_output_trans. */
    469 			m = NULL;
    470 			switch (error) {
    471 			case EHOSTUNREACH:
    472 			case ENETUNREACH:
    473 			case EMSGSIZE:
    474 			case ENOBUFS:
    475 			case ENOMEM:
    476 				break;
    477 			default:
    478 				printf("ip6_output (ipsec): error code %d\n", error);
    479 				/* FALLTHROUGH */
    480 			case ENOENT:
    481 				/* don't show these error codes to the user */
    482 				error = 0;
    483 				break;
    484 			}
    485 			goto bad;
    486 		}
    487 		if (exthdrs.ip6e_rthdr) {
    488 			/* ah6_output doesn't modify mbuf chain */
    489 			rh->ip6r_segleft = segleft_org;
    490 		}
    491 	    }
    492 skip_ipsec2:;
    493 #endif
    494 	}
    495 
    496 	/*
    497 	 * If there is a routing header, replace destination address field
    498 	 * with the first hop of the routing header.
    499 	 */
    500 	if (exthdrs.ip6e_rthdr) {
    501 		struct ip6_rthdr *rh;
    502 		struct ip6_rthdr0 *rh0;
    503 		struct in6_addr *addr;
    504 		struct sockaddr_in6 sa;
    505 
    506 		rh = (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
    507 		    struct ip6_rthdr *));
    508 		finaldst = ip6->ip6_dst;
    509 		switch (rh->ip6r_type) {
    510 		case IPV6_RTHDR_TYPE_0:
    511 			 rh0 = (struct ip6_rthdr0 *)rh;
    512 			 addr = (struct in6_addr *)(rh0 + 1);
    513 
    514 			 /*
    515 			  * construct a sockaddr_in6 form of
    516 			  * the first hop.
    517 			  *
    518 			  * XXX: we may not have enough
    519 			  * information about its scope zone;
    520 			  * there is no standard API to pass
    521 			  * the information from the
    522 			  * application.
    523 			  */
    524 			 sockaddr_in6_init(&sa, addr, 0, 0, 0);
    525 			 if ((error = sa6_embedscope(&sa,
    526 			     ip6_use_defzone)) != 0) {
    527 				 goto bad;
    528 			 }
    529 			 ip6->ip6_dst = sa.sin6_addr;
    530 			 (void)memmove(&addr[0], &addr[1],
    531 			     sizeof(struct in6_addr) *
    532 			     (rh0->ip6r0_segleft - 1));
    533 			 addr[rh0->ip6r0_segleft - 1] = finaldst;
    534 			 /* XXX */
    535 			 in6_clearscope(addr + rh0->ip6r0_segleft - 1);
    536 			 break;
    537 		default:	/* is it possible? */
    538 			 error = EINVAL;
    539 			 goto bad;
    540 		}
    541 	}
    542 
    543 	/* Source address validation */
    544 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
    545 	    (flags & IPV6_UNSPECSRC) == 0) {
    546 		error = EOPNOTSUPP;
    547 		IP6_STATINC(IP6_STAT_BADSCOPE);
    548 		goto bad;
    549 	}
    550 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
    551 		error = EOPNOTSUPP;
    552 		IP6_STATINC(IP6_STAT_BADSCOPE);
    553 		goto bad;
    554 	}
    555 
    556 	IP6_STATINC(IP6_STAT_LOCALOUT);
    557 
    558 	/*
    559 	 * Route packet.
    560 	 */
    561 	/* initialize cached route */
    562 	if (ro == NULL) {
    563 		ro = &ip6route;
    564 	}
    565 	ro_pmtu = ro;
    566 	if (opt && opt->ip6po_rthdr)
    567 		ro = &opt->ip6po_route;
    568 
    569  	/*
    570 	 * if specified, try to fill in the traffic class field.
    571 	 * do not override if a non-zero value is already set.
    572 	 * we check the diffserv field and the ecn field separately.
    573 	 */
    574 	if (opt && opt->ip6po_tclass >= 0) {
    575 		int mask = 0;
    576 
    577 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
    578 			mask |= 0xfc;
    579 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
    580 			mask |= 0x03;
    581 		if (mask != 0)
    582 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
    583 	}
    584 
    585 	/* fill in or override the hop limit field, if necessary. */
    586 	if (opt && opt->ip6po_hlim != -1)
    587 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
    588 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    589 		if (im6o != NULL)
    590 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
    591 		else
    592 			ip6->ip6_hlim = ip6_defmcasthlim;
    593 	}
    594 
    595 #ifdef KAME_IPSEC
    596 	if (needipsec && needipsectun) {
    597 		struct ipsec_output_state state;
    598 
    599 		/*
    600 		 * All the extension headers will become inaccessible
    601 		 * (since they can be encrypted).
    602 		 * Don't panic, we need no more updates to extension headers
    603 		 * on inner IPv6 packet (since they are now encapsulated).
    604 		 *
    605 		 * IPv6 [ESP|AH] IPv6 [extension headers] payload
    606 		 */
    607 		memset(&exthdrs, 0, sizeof(exthdrs));
    608 		exthdrs.ip6e_ip6 = m;
    609 
    610 		memset(&state, 0, sizeof(state));
    611 		state.m = m;
    612 		state.ro = ro;
    613 		state.dst = rtcache_getdst(ro);
    614 
    615 		error = ipsec6_output_tunnel(&state, sp, flags);
    616 
    617 		m = state.m;
    618 		ro_pmtu = ro = state.ro;
    619 		dst = satocsin6(state.dst);
    620 		if (error) {
    621 			/* mbuf is already reclaimed in ipsec6_output_tunnel. */
    622 			m0 = m = NULL;
    623 			m = NULL;
    624 			switch (error) {
    625 			case EHOSTUNREACH:
    626 			case ENETUNREACH:
    627 			case EMSGSIZE:
    628 			case ENOBUFS:
    629 			case ENOMEM:
    630 				break;
    631 			default:
    632 				printf("ip6_output (ipsec): error code %d\n", error);
    633 				/* FALLTHROUGH */
    634 			case ENOENT:
    635 				/* don't show these error codes to the user */
    636 				error = 0;
    637 				break;
    638 			}
    639 			goto bad;
    640 		}
    641 
    642 		exthdrs.ip6e_ip6 = m;
    643 	}
    644 #endif /* KAME_IPSEC */
    645 #ifdef FAST_IPSEC
    646 	if (needipsec) {
    647 		s = splsoftnet();
    648 		error = ipsec6_process_packet(m,sp->req);
    649 
    650 		/*
    651 		 * Preserve KAME behaviour: ENOENT can be returned
    652 		 * when an SA acquire is in progress.  Don't propagate
    653 		 * this to user-level; it confuses applications.
    654 		 * XXX this will go away when the SADB is redone.
    655 		 */
    656 		if (error == ENOENT)
    657 			error = 0;
    658 		splx(s);
    659 		goto done;
    660 	}
    661 #endif /* FAST_IPSEC */
    662 
    663 
    664 
    665 	/* adjust pointer */
    666 	ip6 = mtod(m, struct ip6_hdr *);
    667 
    668 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    669 	if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
    670 	    &ifp, &rt, 0)) != 0) {
    671 		if (ifp != NULL)
    672 			in6_ifstat_inc(ifp, ifs6_out_discard);
    673 		goto bad;
    674 	}
    675 	if (rt == NULL) {
    676 		/*
    677 		 * If in6_selectroute() does not return a route entry,
    678 		 * dst may not have been updated.
    679 		 */
    680 		error = rtcache_setdst(ro, sin6tosa(&dst_sa));
    681 		if (error) {
    682 			goto bad;
    683 		}
    684 	}
    685 
    686 	/*
    687 	 * then rt (for unicast) and ifp must be non-NULL valid values.
    688 	 */
    689 	if ((flags & IPV6_FORWARDING) == 0) {
    690 		/* XXX: the FORWARDING flag can be set for mrouting. */
    691 		in6_ifstat_inc(ifp, ifs6_out_request);
    692 	}
    693 	if (rt != NULL) {
    694 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
    695 		rt->rt_use++;
    696 	}
    697 
    698 	/*
    699 	 * The outgoing interface must be in the zone of source and
    700 	 * destination addresses.  We should use ia_ifp to support the
    701 	 * case of sending packets to an address of our own.
    702 	 */
    703 	if (ia != NULL && ia->ia_ifp)
    704 		origifp = ia->ia_ifp;
    705 	else
    706 		origifp = ifp;
    707 
    708 	src0 = ip6->ip6_src;
    709 	if (in6_setscope(&src0, origifp, &zone))
    710 		goto badscope;
    711 	sockaddr_in6_init(&src_sa, &ip6->ip6_src, 0, 0, 0);
    712 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
    713 		goto badscope;
    714 
    715 	dst0 = ip6->ip6_dst;
    716 	if (in6_setscope(&dst0, origifp, &zone))
    717 		goto badscope;
    718 	/* re-initialize to be sure */
    719 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    720 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id)
    721 		goto badscope;
    722 
    723 	/* scope check is done. */
    724 
    725 	if (rt == NULL || IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    726 		if (dst == NULL)
    727 			dst = satocsin6(rtcache_getdst(ro));
    728 		KASSERT(dst != NULL);
    729 	} else if (opt && rtcache_validate(&opt->ip6po_nextroute) != NULL) {
    730 		/*
    731 		 * The nexthop is explicitly specified by the
    732 		 * application.  We assume the next hop is an IPv6
    733 		 * address.
    734 		 */
    735 		dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
    736 	} else if ((rt->rt_flags & RTF_GATEWAY))
    737 		dst = (struct sockaddr_in6 *)rt->rt_gateway;
    738 	else if (dst == NULL)
    739 		dst = satocsin6(rtcache_getdst(ro));
    740 
    741 	/*
    742 	 * XXXXXX: original code follows:
    743 	 */
    744 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
    745 		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
    746 	else {
    747 		struct	in6_multi *in6m;
    748 
    749 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
    750 
    751 		in6_ifstat_inc(ifp, ifs6_out_mcast);
    752 
    753 		/*
    754 		 * Confirm that the outgoing interface supports multicast.
    755 		 */
    756 		if (!(ifp->if_flags & IFF_MULTICAST)) {
    757 			IP6_STATINC(IP6_STAT_NOROUTE);
    758 			in6_ifstat_inc(ifp, ifs6_out_discard);
    759 			error = ENETUNREACH;
    760 			goto bad;
    761 		}
    762 
    763 		IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
    764 		if (in6m != NULL &&
    765 		   (im6o == NULL || im6o->im6o_multicast_loop)) {
    766 			/*
    767 			 * If we belong to the destination multicast group
    768 			 * on the outgoing interface, and the caller did not
    769 			 * forbid loopback, loop back a copy.
    770 			 */
    771 			KASSERT(dst != NULL);
    772 			ip6_mloopback(ifp, m, dst);
    773 		} else {
    774 			/*
    775 			 * If we are acting as a multicast router, perform
    776 			 * multicast forwarding as if the packet had just
    777 			 * arrived on the interface to which we are about
    778 			 * to send.  The multicast forwarding function
    779 			 * recursively calls this function, using the
    780 			 * IPV6_FORWARDING flag to prevent infinite recursion.
    781 			 *
    782 			 * Multicasts that are looped back by ip6_mloopback(),
    783 			 * above, will be forwarded by the ip6_input() routine,
    784 			 * if necessary.
    785 			 */
    786 			if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
    787 				if (ip6_mforward(ip6, ifp, m) != 0) {
    788 					m_freem(m);
    789 					goto done;
    790 				}
    791 			}
    792 		}
    793 		/*
    794 		 * Multicasts with a hoplimit of zero may be looped back,
    795 		 * above, but must not be transmitted on a network.
    796 		 * Also, multicasts addressed to the loopback interface
    797 		 * are not sent -- the above call to ip6_mloopback() will
    798 		 * loop back a copy if this host actually belongs to the
    799 		 * destination group on the loopback interface.
    800 		 */
    801 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
    802 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
    803 			m_freem(m);
    804 			goto done;
    805 		}
    806 	}
    807 
    808 	/*
    809 	 * Fill the outgoing inteface to tell the upper layer
    810 	 * to increment per-interface statistics.
    811 	 */
    812 	if (ifpp)
    813 		*ifpp = ifp;
    814 
    815 	/* Determine path MTU. */
    816 	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
    817 	    &alwaysfrag)) != 0)
    818 		goto bad;
    819 #ifdef KAME_IPSEC
    820 	if (needipsectun)
    821 		mtu = IPV6_MMTU;
    822 #endif
    823 
    824 	/*
    825 	 * The caller of this function may specify to use the minimum MTU
    826 	 * in some cases.
    827 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
    828 	 * setting.  The logic is a bit complicated; by default, unicast
    829 	 * packets will follow path MTU while multicast packets will be sent at
    830 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
    831 	 * including unicast ones will be sent at the minimum MTU.  Multicast
    832 	 * packets will always be sent at the minimum MTU unless
    833 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
    834 	 * See RFC 3542 for more details.
    835 	 */
    836 	if (mtu > IPV6_MMTU) {
    837 		if ((flags & IPV6_MINMTU))
    838 			mtu = IPV6_MMTU;
    839 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
    840 			mtu = IPV6_MMTU;
    841 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
    842 			 (opt == NULL ||
    843 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
    844 			mtu = IPV6_MMTU;
    845 		}
    846 	}
    847 
    848 	/*
    849 	 * clear embedded scope identifiers if necessary.
    850 	 * in6_clearscope will touch the addresses only when necessary.
    851 	 */
    852 	in6_clearscope(&ip6->ip6_src);
    853 	in6_clearscope(&ip6->ip6_dst);
    854 
    855 	/*
    856 	 * If the outgoing packet contains a hop-by-hop options header,
    857 	 * it must be examined and processed even by the source node.
    858 	 * (RFC 2460, section 4.)
    859 	 */
    860 	if (ip6->ip6_nxt == IPV6_HOPOPTS) {
    861 		u_int32_t dummy1; /* XXX unused */
    862 		u_int32_t dummy2; /* XXX unused */
    863 		int hoff = sizeof(struct ip6_hdr);
    864 
    865 		if (ip6_hopopts_input(&dummy1, &dummy2, &m, &hoff)) {
    866 			/* m was already freed at this point */
    867 			error = EINVAL;/* better error? */
    868 			goto done;
    869 		}
    870 
    871 		ip6 = mtod(m, struct ip6_hdr *);
    872 	}
    873 
    874 #ifdef PFIL_HOOKS
    875 	/*
    876 	 * Run through list of hooks for output packets.
    877 	 */
    878 	if ((error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT)) != 0)
    879 		goto done;
    880 	if (m == NULL)
    881 		goto done;
    882 	ip6 = mtod(m, struct ip6_hdr *);
    883 #endif /* PFIL_HOOKS */
    884 	/*
    885 	 * Send the packet to the outgoing interface.
    886 	 * If necessary, do IPv6 fragmentation before sending.
    887 	 *
    888 	 * the logic here is rather complex:
    889 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
    890 	 * 1-a:	send as is if tlen <= path mtu
    891 	 * 1-b:	fragment if tlen > path mtu
    892 	 *
    893 	 * 2: if user asks us not to fragment (dontfrag == 1)
    894 	 * 2-a:	send as is if tlen <= interface mtu
    895 	 * 2-b:	error if tlen > interface mtu
    896 	 *
    897 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
    898 	 *	always fragment
    899 	 *
    900 	 * 4: if dontfrag == 1 && alwaysfrag == 1
    901 	 *	error, as we cannot handle this conflicting request
    902 	 */
    903 	tlen = m->m_pkthdr.len;
    904 	tso = (m->m_pkthdr.csum_flags & M_CSUM_TSOv6) != 0;
    905 	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
    906 		dontfrag = 1;
    907 	else
    908 		dontfrag = 0;
    909 
    910 	if (dontfrag && alwaysfrag) {	/* case 4 */
    911 		/* conflicting request - can't transmit */
    912 		error = EMSGSIZE;
    913 		goto bad;
    914 	}
    915 	if (dontfrag && (!tso && tlen > IN6_LINKMTU(ifp))) {	/* case 2-b */
    916 		/*
    917 		 * Even if the DONTFRAG option is specified, we cannot send the
    918 		 * packet when the data length is larger than the MTU of the
    919 		 * outgoing interface.
    920 		 * Notify the error by sending IPV6_PATHMTU ancillary data as
    921 		 * well as returning an error code (the latter is not described
    922 		 * in the API spec.)
    923 		 */
    924 		u_int32_t mtu32;
    925 		struct ip6ctlparam ip6cp;
    926 
    927 		mtu32 = (u_int32_t)mtu;
    928 		memset(&ip6cp, 0, sizeof(ip6cp));
    929 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
    930 		pfctlinput2(PRC_MSGSIZE,
    931 		    rtcache_getdst(ro_pmtu), &ip6cp);
    932 
    933 		error = EMSGSIZE;
    934 		goto bad;
    935 	}
    936 
    937 	/*
    938 	 * transmit packet without fragmentation
    939 	 */
    940 	if (dontfrag || (!alwaysfrag && (tlen <= mtu || tso))) {
    941 		/* case 1-a and 2-a */
    942 		struct in6_ifaddr *ia6;
    943 		int sw_csum;
    944 
    945 		ip6 = mtod(m, struct ip6_hdr *);
    946 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
    947 		if (ia6) {
    948 			/* Record statistics for this interface address. */
    949 			ia6->ia_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len;
    950 		}
    951 #ifdef KAME_IPSEC
    952 		/* clean ipsec history once it goes out of the node */
    953 		ipsec_delaux(m);
    954 #endif
    955 
    956 		sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx;
    957 		if ((sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    958 			if (IN6_NEED_CHECKSUM(ifp,
    959 			    sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
    960 				in6_delayed_cksum(m);
    961 			}
    962 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    963 		}
    964 
    965 		KASSERT(dst != NULL);
    966 		if (__predict_true(!tso ||
    967 		    (ifp->if_capenable & IFCAP_TSOv6) != 0)) {
    968 			error = nd6_output(ifp, origifp, m, dst, rt);
    969 		} else {
    970 			error = ip6_tso_output(ifp, origifp, m, dst, rt);
    971 		}
    972 		goto done;
    973 	}
    974 
    975 	if (tso) {
    976 		error = EINVAL; /* XXX */
    977 		goto bad;
    978 	}
    979 
    980 	/*
    981 	 * try to fragment the packet.  case 1-b and 3
    982 	 */
    983 	if (mtu < IPV6_MMTU) {
    984 		/* path MTU cannot be less than IPV6_MMTU */
    985 		error = EMSGSIZE;
    986 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
    987 		goto bad;
    988 	} else if (ip6->ip6_plen == 0) {
    989 		/* jumbo payload cannot be fragmented */
    990 		error = EMSGSIZE;
    991 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
    992 		goto bad;
    993 	} else {
    994 		struct mbuf **mnext, *m_frgpart;
    995 		struct ip6_frag *ip6f;
    996 		u_int32_t id = htonl(ip6_randomid());
    997 		u_char nextproto;
    998 #if 0				/* see below */
    999 		struct ip6ctlparam ip6cp;
   1000 		u_int32_t mtu32;
   1001 #endif
   1002 
   1003 		/*
   1004 		 * Too large for the destination or interface;
   1005 		 * fragment if possible.
   1006 		 * Must be able to put at least 8 bytes per fragment.
   1007 		 */
   1008 		hlen = unfragpartlen;
   1009 		if (mtu > IPV6_MAXPACKET)
   1010 			mtu = IPV6_MAXPACKET;
   1011 
   1012 #if 0
   1013 		/*
   1014 		 * It is believed this code is a leftover from the
   1015 		 * development of the IPV6_RECVPATHMTU sockopt and
   1016 		 * associated work to implement RFC3542.
   1017 		 * It's not entirely clear what the intent of the API
   1018 		 * is at this point, so disable this code for now.
   1019 		 * The IPV6_RECVPATHMTU sockopt and/or IPV6_DONTFRAG
   1020 		 * will send notifications if the application requests.
   1021 		 */
   1022 
   1023 		/* Notify a proper path MTU to applications. */
   1024 		mtu32 = (u_int32_t)mtu;
   1025 		memset(&ip6cp, 0, sizeof(ip6cp));
   1026 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
   1027 		pfctlinput2(PRC_MSGSIZE,
   1028 		    rtcache_getdst(ro_pmtu), &ip6cp);
   1029 #endif
   1030 
   1031 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
   1032 		if (len < 8) {
   1033 			error = EMSGSIZE;
   1034 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
   1035 			goto bad;
   1036 		}
   1037 
   1038 		mnext = &m->m_nextpkt;
   1039 
   1040 		/*
   1041 		 * Change the next header field of the last header in the
   1042 		 * unfragmentable part.
   1043 		 */
   1044 		if (exthdrs.ip6e_rthdr) {
   1045 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
   1046 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
   1047 		} else if (exthdrs.ip6e_dest1) {
   1048 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
   1049 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
   1050 		} else if (exthdrs.ip6e_hbh) {
   1051 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
   1052 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
   1053 		} else {
   1054 			nextproto = ip6->ip6_nxt;
   1055 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
   1056 		}
   1057 
   1058 		if ((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6))
   1059 		    != 0) {
   1060 			if (IN6_NEED_CHECKSUM(ifp,
   1061 			    m->m_pkthdr.csum_flags &
   1062 			    (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
   1063 				in6_delayed_cksum(m);
   1064 			}
   1065 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
   1066 		}
   1067 
   1068 		/*
   1069 		 * Loop through length of segment after first fragment,
   1070 		 * make new header and copy data of each part and link onto
   1071 		 * chain.
   1072 		 */
   1073 		m0 = m;
   1074 		for (off = hlen; off < tlen; off += len) {
   1075 			struct mbuf *mlast;
   1076 
   1077 			MGETHDR(m, M_DONTWAIT, MT_HEADER);
   1078 			if (!m) {
   1079 				error = ENOBUFS;
   1080 				IP6_STATINC(IP6_STAT_ODROPPED);
   1081 				goto sendorfree;
   1082 			}
   1083 			m->m_pkthdr.rcvif = NULL;
   1084 			m->m_flags = m0->m_flags & M_COPYFLAGS;
   1085 			*mnext = m;
   1086 			mnext = &m->m_nextpkt;
   1087 			m->m_data += max_linkhdr;
   1088 			mhip6 = mtod(m, struct ip6_hdr *);
   1089 			*mhip6 = *ip6;
   1090 			m->m_len = sizeof(*mhip6);
   1091 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
   1092 			if (error) {
   1093 				IP6_STATINC(IP6_STAT_ODROPPED);
   1094 				goto sendorfree;
   1095 			}
   1096 			ip6f->ip6f_offlg = htons((u_int16_t)((off - hlen) & ~7));
   1097 			if (off + len >= tlen)
   1098 				len = tlen - off;
   1099 			else
   1100 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
   1101 			mhip6->ip6_plen = htons((u_int16_t)(len + hlen +
   1102 			    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
   1103 			if ((m_frgpart = m_copy(m0, off, len)) == 0) {
   1104 				error = ENOBUFS;
   1105 				IP6_STATINC(IP6_STAT_ODROPPED);
   1106 				goto sendorfree;
   1107 			}
   1108 			for (mlast = m; mlast->m_next; mlast = mlast->m_next)
   1109 				;
   1110 			mlast->m_next = m_frgpart;
   1111 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
   1112 			m->m_pkthdr.rcvif = NULL;
   1113 			ip6f->ip6f_reserved = 0;
   1114 			ip6f->ip6f_ident = id;
   1115 			ip6f->ip6f_nxt = nextproto;
   1116 			IP6_STATINC(IP6_STAT_OFRAGMENTS);
   1117 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
   1118 		}
   1119 
   1120 		in6_ifstat_inc(ifp, ifs6_out_fragok);
   1121 	}
   1122 
   1123 	/*
   1124 	 * Remove leading garbages.
   1125 	 */
   1126 sendorfree:
   1127 	m = m0->m_nextpkt;
   1128 	m0->m_nextpkt = 0;
   1129 	m_freem(m0);
   1130 	for (m0 = m; m; m = m0) {
   1131 		m0 = m->m_nextpkt;
   1132 		m->m_nextpkt = 0;
   1133 		if (error == 0) {
   1134 			struct in6_ifaddr *ia6;
   1135 			ip6 = mtod(m, struct ip6_hdr *);
   1136 			ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
   1137 			if (ia6) {
   1138 				/*
   1139 				 * Record statistics for this interface
   1140 				 * address.
   1141 				 */
   1142 				ia6->ia_ifa.ifa_data.ifad_outbytes +=
   1143 				    m->m_pkthdr.len;
   1144 			}
   1145 #ifdef KAME_IPSEC
   1146 			/* clean ipsec history once it goes out of the node */
   1147 			ipsec_delaux(m);
   1148 #endif
   1149 			KASSERT(dst != NULL);
   1150 			error = nd6_output(ifp, origifp, m, dst, rt);
   1151 		} else
   1152 			m_freem(m);
   1153 	}
   1154 
   1155 	if (error == 0)
   1156 		IP6_STATINC(IP6_STAT_FRAGMENTED);
   1157 
   1158 done:
   1159 	rtcache_free(&ip6route);
   1160 
   1161 #ifdef KAME_IPSEC
   1162 	if (sp != NULL)
   1163 		key_freesp(sp);
   1164 #endif /* KAME_IPSEC */
   1165 #ifdef FAST_IPSEC
   1166 	if (sp != NULL)
   1167 		KEY_FREESP(&sp);
   1168 #endif /* FAST_IPSEC */
   1169 
   1170 
   1171 	return (error);
   1172 
   1173 freehdrs:
   1174 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
   1175 	m_freem(exthdrs.ip6e_dest1);
   1176 	m_freem(exthdrs.ip6e_rthdr);
   1177 	m_freem(exthdrs.ip6e_dest2);
   1178 	/* FALLTHROUGH */
   1179 bad:
   1180 	m_freem(m);
   1181 	goto done;
   1182 badscope:
   1183 	IP6_STATINC(IP6_STAT_BADSCOPE);
   1184 	in6_ifstat_inc(origifp, ifs6_out_discard);
   1185 	if (error == 0)
   1186 		error = EHOSTUNREACH; /* XXX */
   1187 	goto bad;
   1188 }
   1189 
   1190 static int
   1191 ip6_copyexthdr(struct mbuf **mp, void *hdr, int hlen)
   1192 {
   1193 	struct mbuf *m;
   1194 
   1195 	if (hlen > MCLBYTES)
   1196 		return (ENOBUFS); /* XXX */
   1197 
   1198 	MGET(m, M_DONTWAIT, MT_DATA);
   1199 	if (!m)
   1200 		return (ENOBUFS);
   1201 
   1202 	if (hlen > MLEN) {
   1203 		MCLGET(m, M_DONTWAIT);
   1204 		if ((m->m_flags & M_EXT) == 0) {
   1205 			m_free(m);
   1206 			return (ENOBUFS);
   1207 		}
   1208 	}
   1209 	m->m_len = hlen;
   1210 	if (hdr)
   1211 		bcopy(hdr, mtod(m, void *), hlen);
   1212 
   1213 	*mp = m;
   1214 	return (0);
   1215 }
   1216 
   1217 /*
   1218  * Process a delayed payload checksum calculation.
   1219  */
   1220 void
   1221 in6_delayed_cksum(struct mbuf *m)
   1222 {
   1223 	uint16_t csum, offset;
   1224 
   1225 	KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1226 	KASSERT((~m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1227 	KASSERT((m->m_pkthdr.csum_flags
   1228 	    & (M_CSUM_UDPv4|M_CSUM_TCPv4|M_CSUM_TSOv4)) == 0);
   1229 
   1230 	offset = M_CSUM_DATA_IPv6_HL(m->m_pkthdr.csum_data);
   1231 	csum = in6_cksum(m, 0, offset, m->m_pkthdr.len - offset);
   1232 	if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv6) != 0) {
   1233 		csum = 0xffff;
   1234 	}
   1235 
   1236 	offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data);
   1237 	if ((offset + sizeof(csum)) > m->m_len) {
   1238 		m_copyback(m, offset, sizeof(csum), &csum);
   1239 	} else {
   1240 		*(uint16_t *)(mtod(m, char *) + offset) = csum;
   1241 	}
   1242 }
   1243 
   1244 /*
   1245  * Insert jumbo payload option.
   1246  */
   1247 static int
   1248 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
   1249 {
   1250 	struct mbuf *mopt;
   1251 	u_int8_t *optbuf;
   1252 	u_int32_t v;
   1253 
   1254 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
   1255 
   1256 	/*
   1257 	 * If there is no hop-by-hop options header, allocate new one.
   1258 	 * If there is one but it doesn't have enough space to store the
   1259 	 * jumbo payload option, allocate a cluster to store the whole options.
   1260 	 * Otherwise, use it to store the options.
   1261 	 */
   1262 	if (exthdrs->ip6e_hbh == 0) {
   1263 		MGET(mopt, M_DONTWAIT, MT_DATA);
   1264 		if (mopt == 0)
   1265 			return (ENOBUFS);
   1266 		mopt->m_len = JUMBOOPTLEN;
   1267 		optbuf = mtod(mopt, u_int8_t *);
   1268 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
   1269 		exthdrs->ip6e_hbh = mopt;
   1270 	} else {
   1271 		struct ip6_hbh *hbh;
   1272 
   1273 		mopt = exthdrs->ip6e_hbh;
   1274 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
   1275 			/*
   1276 			 * XXX assumption:
   1277 			 * - exthdrs->ip6e_hbh is not referenced from places
   1278 			 *   other than exthdrs.
   1279 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
   1280 			 */
   1281 			int oldoptlen = mopt->m_len;
   1282 			struct mbuf *n;
   1283 
   1284 			/*
   1285 			 * XXX: give up if the whole (new) hbh header does
   1286 			 * not fit even in an mbuf cluster.
   1287 			 */
   1288 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
   1289 				return (ENOBUFS);
   1290 
   1291 			/*
   1292 			 * As a consequence, we must always prepare a cluster
   1293 			 * at this point.
   1294 			 */
   1295 			MGET(n, M_DONTWAIT, MT_DATA);
   1296 			if (n) {
   1297 				MCLGET(n, M_DONTWAIT);
   1298 				if ((n->m_flags & M_EXT) == 0) {
   1299 					m_freem(n);
   1300 					n = NULL;
   1301 				}
   1302 			}
   1303 			if (!n)
   1304 				return (ENOBUFS);
   1305 			n->m_len = oldoptlen + JUMBOOPTLEN;
   1306 			bcopy(mtod(mopt, void *), mtod(n, void *),
   1307 			    oldoptlen);
   1308 			optbuf = mtod(n, u_int8_t *) + oldoptlen;
   1309 			m_freem(mopt);
   1310 			mopt = exthdrs->ip6e_hbh = n;
   1311 		} else {
   1312 			optbuf = mtod(mopt, u_int8_t *) + mopt->m_len;
   1313 			mopt->m_len += JUMBOOPTLEN;
   1314 		}
   1315 		optbuf[0] = IP6OPT_PADN;
   1316 		optbuf[1] = 0;
   1317 
   1318 		/*
   1319 		 * Adjust the header length according to the pad and
   1320 		 * the jumbo payload option.
   1321 		 */
   1322 		hbh = mtod(mopt, struct ip6_hbh *);
   1323 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
   1324 	}
   1325 
   1326 	/* fill in the option. */
   1327 	optbuf[2] = IP6OPT_JUMBO;
   1328 	optbuf[3] = 4;
   1329 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
   1330 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
   1331 
   1332 	/* finally, adjust the packet header length */
   1333 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
   1334 
   1335 	return (0);
   1336 #undef JUMBOOPTLEN
   1337 }
   1338 
   1339 /*
   1340  * Insert fragment header and copy unfragmentable header portions.
   1341  */
   1342 static int
   1343 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
   1344 	struct ip6_frag **frghdrp)
   1345 {
   1346 	struct mbuf *n, *mlast;
   1347 
   1348 	if (hlen > sizeof(struct ip6_hdr)) {
   1349 		n = m_copym(m0, sizeof(struct ip6_hdr),
   1350 		    hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
   1351 		if (n == 0)
   1352 			return (ENOBUFS);
   1353 		m->m_next = n;
   1354 	} else
   1355 		n = m;
   1356 
   1357 	/* Search for the last mbuf of unfragmentable part. */
   1358 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
   1359 		;
   1360 
   1361 	if ((mlast->m_flags & M_EXT) == 0 &&
   1362 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
   1363 		/* use the trailing space of the last mbuf for the fragment hdr */
   1364 		*frghdrp = (struct ip6_frag *)(mtod(mlast, char *) +
   1365 		    mlast->m_len);
   1366 		mlast->m_len += sizeof(struct ip6_frag);
   1367 		m->m_pkthdr.len += sizeof(struct ip6_frag);
   1368 	} else {
   1369 		/* allocate a new mbuf for the fragment header */
   1370 		struct mbuf *mfrg;
   1371 
   1372 		MGET(mfrg, M_DONTWAIT, MT_DATA);
   1373 		if (mfrg == 0)
   1374 			return (ENOBUFS);
   1375 		mfrg->m_len = sizeof(struct ip6_frag);
   1376 		*frghdrp = mtod(mfrg, struct ip6_frag *);
   1377 		mlast->m_next = mfrg;
   1378 	}
   1379 
   1380 	return (0);
   1381 }
   1382 
   1383 static int
   1384 ip6_getpmtu(struct route *ro_pmtu, struct route *ro, struct ifnet *ifp,
   1385     const struct in6_addr *dst, u_long *mtup, int *alwaysfragp)
   1386 {
   1387 	struct rtentry *rt;
   1388 	u_int32_t mtu = 0;
   1389 	int alwaysfrag = 0;
   1390 	int error = 0;
   1391 
   1392 	if (ro_pmtu != ro) {
   1393 		union {
   1394 			struct sockaddr		dst;
   1395 			struct sockaddr_in6	dst6;
   1396 		} u;
   1397 
   1398 		/* The first hop and the final destination may differ. */
   1399 		sockaddr_in6_init(&u.dst6, dst, 0, 0, 0);
   1400 		rt = rtcache_lookup(ro_pmtu, &u.dst);
   1401 	} else
   1402 		rt = rtcache_validate(ro_pmtu);
   1403 	if (rt != NULL) {
   1404 		u_int32_t ifmtu;
   1405 
   1406 		if (ifp == NULL)
   1407 			ifp = rt->rt_ifp;
   1408 		ifmtu = IN6_LINKMTU(ifp);
   1409 		mtu = rt->rt_rmx.rmx_mtu;
   1410 		if (mtu == 0)
   1411 			mtu = ifmtu;
   1412 		else if (mtu < IPV6_MMTU) {
   1413 			/*
   1414 			 * RFC2460 section 5, last paragraph:
   1415 			 * if we record ICMPv6 too big message with
   1416 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
   1417 			 * or smaller, with fragment header attached.
   1418 			 * (fragment header is needed regardless from the
   1419 			 * packet size, for translators to identify packets)
   1420 			 */
   1421 			alwaysfrag = 1;
   1422 			mtu = IPV6_MMTU;
   1423 		} else if (mtu > ifmtu) {
   1424 			/*
   1425 			 * The MTU on the route is larger than the MTU on
   1426 			 * the interface!  This shouldn't happen, unless the
   1427 			 * MTU of the interface has been changed after the
   1428 			 * interface was brought up.  Change the MTU in the
   1429 			 * route to match the interface MTU (as long as the
   1430 			 * field isn't locked).
   1431 			 */
   1432 			mtu = ifmtu;
   1433 			if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
   1434 				rt->rt_rmx.rmx_mtu = mtu;
   1435 		}
   1436 	} else if (ifp) {
   1437 		mtu = IN6_LINKMTU(ifp);
   1438 	} else
   1439 		error = EHOSTUNREACH; /* XXX */
   1440 
   1441 	*mtup = mtu;
   1442 	if (alwaysfragp)
   1443 		*alwaysfragp = alwaysfrag;
   1444 	return (error);
   1445 }
   1446 
   1447 /*
   1448  * IP6 socket option processing.
   1449  */
   1450 int
   1451 ip6_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   1452 {
   1453 	int optdatalen, uproto;
   1454 	void *optdata;
   1455 	struct in6pcb *in6p = sotoin6pcb(so);
   1456 	int error, optval;
   1457 	int level, optname;
   1458 
   1459 	KASSERT(sopt != NULL);
   1460 
   1461 	level = sopt->sopt_level;
   1462 	optname = sopt->sopt_name;
   1463 
   1464 	error = optval = 0;
   1465 	uproto = (int)so->so_proto->pr_protocol;
   1466 
   1467 	if (level != IPPROTO_IPV6) {
   1468 		return ENOPROTOOPT;
   1469 	}
   1470 	switch (op) {
   1471 	case PRCO_SETOPT:
   1472 		switch (optname) {
   1473 #ifdef RFC2292
   1474 		case IPV6_2292PKTOPTIONS:
   1475 			error = ip6_pcbopts(&in6p->in6p_outputopts, so, sopt);
   1476 			break;
   1477 #endif
   1478 
   1479 		/*
   1480 		 * Use of some Hop-by-Hop options or some
   1481 		 * Destination options, might require special
   1482 		 * privilege.  That is, normal applications
   1483 		 * (without special privilege) might be forbidden
   1484 		 * from setting certain options in outgoing packets,
   1485 		 * and might never see certain options in received
   1486 		 * packets. [RFC 2292 Section 6]
   1487 		 * KAME specific note:
   1488 		 *  KAME prevents non-privileged users from sending or
   1489 		 *  receiving ANY hbh/dst options in order to avoid
   1490 		 *  overhead of parsing options in the kernel.
   1491 		 */
   1492 		case IPV6_RECVHOPOPTS:
   1493 		case IPV6_RECVDSTOPTS:
   1494 		case IPV6_RECVRTHDRDSTOPTS:
   1495 			error = kauth_authorize_network(kauth_cred_get(),
   1496 			    KAUTH_NETWORK_IPV6, KAUTH_REQ_NETWORK_IPV6_HOPBYHOP,
   1497 			    NULL, NULL, NULL);
   1498 			if (error)
   1499 				break;
   1500 			/* FALLTHROUGH */
   1501 		case IPV6_UNICAST_HOPS:
   1502 		case IPV6_HOPLIMIT:
   1503 		case IPV6_FAITH:
   1504 
   1505 		case IPV6_RECVPKTINFO:
   1506 		case IPV6_RECVHOPLIMIT:
   1507 		case IPV6_RECVRTHDR:
   1508 		case IPV6_RECVPATHMTU:
   1509 		case IPV6_RECVTCLASS:
   1510 		case IPV6_V6ONLY:
   1511 			error = sockopt_getint(sopt, &optval);
   1512 			if (error)
   1513 				break;
   1514 			switch (optname) {
   1515 			case IPV6_UNICAST_HOPS:
   1516 				if (optval < -1 || optval >= 256)
   1517 					error = EINVAL;
   1518 				else {
   1519 					/* -1 = kernel default */
   1520 					in6p->in6p_hops = optval;
   1521 				}
   1522 				break;
   1523 #define OPTSET(bit) \
   1524 do { \
   1525 if (optval) \
   1526 	in6p->in6p_flags |= (bit); \
   1527 else \
   1528 	in6p->in6p_flags &= ~(bit); \
   1529 } while (/*CONSTCOND*/ 0)
   1530 
   1531 #ifdef RFC2292
   1532 #define OPTSET2292(bit) 			\
   1533 do { 						\
   1534 in6p->in6p_flags |= IN6P_RFC2292; 	\
   1535 if (optval) 				\
   1536 	in6p->in6p_flags |= (bit); 	\
   1537 else 					\
   1538 	in6p->in6p_flags &= ~(bit); 	\
   1539 } while (/*CONSTCOND*/ 0)
   1540 #endif
   1541 
   1542 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
   1543 
   1544 			case IPV6_RECVPKTINFO:
   1545 #ifdef RFC2292
   1546 				/* cannot mix with RFC2292 */
   1547 				if (OPTBIT(IN6P_RFC2292)) {
   1548 					error = EINVAL;
   1549 					break;
   1550 				}
   1551 #endif
   1552 				OPTSET(IN6P_PKTINFO);
   1553 				break;
   1554 
   1555 			case IPV6_HOPLIMIT:
   1556 			{
   1557 				struct ip6_pktopts **optp;
   1558 
   1559 #ifdef RFC2292
   1560 				/* cannot mix with RFC2292 */
   1561 				if (OPTBIT(IN6P_RFC2292)) {
   1562 					error = EINVAL;
   1563 					break;
   1564 				}
   1565 #endif
   1566 				optp = &in6p->in6p_outputopts;
   1567 				error = ip6_pcbopt(IPV6_HOPLIMIT,
   1568 						   (u_char *)&optval,
   1569 						   sizeof(optval),
   1570 						   optp,
   1571 						   kauth_cred_get(), uproto);
   1572 				break;
   1573 			}
   1574 
   1575 			case IPV6_RECVHOPLIMIT:
   1576 #ifdef RFC2292
   1577 				/* cannot mix with RFC2292 */
   1578 				if (OPTBIT(IN6P_RFC2292)) {
   1579 					error = EINVAL;
   1580 					break;
   1581 				}
   1582 #endif
   1583 				OPTSET(IN6P_HOPLIMIT);
   1584 				break;
   1585 
   1586 			case IPV6_RECVHOPOPTS:
   1587 #ifdef RFC2292
   1588 				/* cannot mix with RFC2292 */
   1589 				if (OPTBIT(IN6P_RFC2292)) {
   1590 					error = EINVAL;
   1591 					break;
   1592 				}
   1593 #endif
   1594 				OPTSET(IN6P_HOPOPTS);
   1595 				break;
   1596 
   1597 			case IPV6_RECVDSTOPTS:
   1598 #ifdef RFC2292
   1599 				/* cannot mix with RFC2292 */
   1600 				if (OPTBIT(IN6P_RFC2292)) {
   1601 					error = EINVAL;
   1602 					break;
   1603 				}
   1604 #endif
   1605 				OPTSET(IN6P_DSTOPTS);
   1606 				break;
   1607 
   1608 			case IPV6_RECVRTHDRDSTOPTS:
   1609 #ifdef RFC2292
   1610 				/* cannot mix with RFC2292 */
   1611 				if (OPTBIT(IN6P_RFC2292)) {
   1612 					error = EINVAL;
   1613 					break;
   1614 				}
   1615 #endif
   1616 				OPTSET(IN6P_RTHDRDSTOPTS);
   1617 				break;
   1618 
   1619 			case IPV6_RECVRTHDR:
   1620 #ifdef RFC2292
   1621 				/* cannot mix with RFC2292 */
   1622 				if (OPTBIT(IN6P_RFC2292)) {
   1623 					error = EINVAL;
   1624 					break;
   1625 				}
   1626 #endif
   1627 				OPTSET(IN6P_RTHDR);
   1628 				break;
   1629 
   1630 			case IPV6_FAITH:
   1631 				OPTSET(IN6P_FAITH);
   1632 				break;
   1633 
   1634 			case IPV6_RECVPATHMTU:
   1635 				/*
   1636 				 * We ignore this option for TCP
   1637 				 * sockets.
   1638 				 * (RFC3542 leaves this case
   1639 				 * unspecified.)
   1640 				 */
   1641 				if (uproto != IPPROTO_TCP)
   1642 					OPTSET(IN6P_MTU);
   1643 				break;
   1644 
   1645 			case IPV6_V6ONLY:
   1646 				/*
   1647 				 * make setsockopt(IPV6_V6ONLY)
   1648 				 * available only prior to bind(2).
   1649 				 * see ipng mailing list, Jun 22 2001.
   1650 				 */
   1651 				if (in6p->in6p_lport ||
   1652 				    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
   1653 					error = EINVAL;
   1654 					break;
   1655 				}
   1656 #ifdef INET6_BINDV6ONLY
   1657 				if (!optval)
   1658 					error = EINVAL;
   1659 #else
   1660 				OPTSET(IN6P_IPV6_V6ONLY);
   1661 #endif
   1662 				break;
   1663 			case IPV6_RECVTCLASS:
   1664 #ifdef RFC2292
   1665 				/* cannot mix with RFC2292 XXX */
   1666 				if (OPTBIT(IN6P_RFC2292)) {
   1667 					error = EINVAL;
   1668 					break;
   1669 				}
   1670 #endif
   1671 				OPTSET(IN6P_TCLASS);
   1672 				break;
   1673 
   1674 			}
   1675 			break;
   1676 
   1677 		case IPV6_OTCLASS:
   1678 		{
   1679 			struct ip6_pktopts **optp;
   1680 			u_int8_t tclass;
   1681 
   1682 			error = sockopt_get(sopt, &tclass, sizeof(tclass));
   1683 			if (error)
   1684 				break;
   1685 			optp = &in6p->in6p_outputopts;
   1686 			error = ip6_pcbopt(optname,
   1687 					   (u_char *)&tclass,
   1688 					   sizeof(tclass),
   1689 					   optp,
   1690 					   kauth_cred_get(), uproto);
   1691 			break;
   1692 		}
   1693 
   1694 		case IPV6_TCLASS:
   1695 		case IPV6_DONTFRAG:
   1696 		case IPV6_USE_MIN_MTU:
   1697 			error = sockopt_getint(sopt, &optval);
   1698 			if (error)
   1699 				break;
   1700 			{
   1701 				struct ip6_pktopts **optp;
   1702 				optp = &in6p->in6p_outputopts;
   1703 				error = ip6_pcbopt(optname,
   1704 						   (u_char *)&optval,
   1705 						   sizeof(optval),
   1706 						   optp,
   1707 						   kauth_cred_get(), uproto);
   1708 				break;
   1709 			}
   1710 
   1711 #ifdef RFC2292
   1712 		case IPV6_2292PKTINFO:
   1713 		case IPV6_2292HOPLIMIT:
   1714 		case IPV6_2292HOPOPTS:
   1715 		case IPV6_2292DSTOPTS:
   1716 		case IPV6_2292RTHDR:
   1717 			/* RFC 2292 */
   1718 			error = sockopt_getint(sopt, &optval);
   1719 			if (error)
   1720 				break;
   1721 
   1722 			switch (optname) {
   1723 			case IPV6_2292PKTINFO:
   1724 				OPTSET2292(IN6P_PKTINFO);
   1725 				break;
   1726 			case IPV6_2292HOPLIMIT:
   1727 				OPTSET2292(IN6P_HOPLIMIT);
   1728 				break;
   1729 			case IPV6_2292HOPOPTS:
   1730 				/*
   1731 				 * Check super-user privilege.
   1732 				 * See comments for IPV6_RECVHOPOPTS.
   1733 				 */
   1734 				error =
   1735 				    kauth_authorize_network(kauth_cred_get(),
   1736 				    KAUTH_NETWORK_IPV6,
   1737 				    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL,
   1738 				    NULL, NULL);
   1739 				if (error)
   1740 					return (error);
   1741 				OPTSET2292(IN6P_HOPOPTS);
   1742 				break;
   1743 			case IPV6_2292DSTOPTS:
   1744 				error =
   1745 				    kauth_authorize_network(kauth_cred_get(),
   1746 				    KAUTH_NETWORK_IPV6,
   1747 				    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL,
   1748 				    NULL, NULL);
   1749 				if (error)
   1750 					return (error);
   1751 				OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
   1752 				break;
   1753 			case IPV6_2292RTHDR:
   1754 				OPTSET2292(IN6P_RTHDR);
   1755 				break;
   1756 			}
   1757 			break;
   1758 #endif
   1759 		case IPV6_PKTINFO:
   1760 		case IPV6_HOPOPTS:
   1761 		case IPV6_RTHDR:
   1762 		case IPV6_DSTOPTS:
   1763 		case IPV6_RTHDRDSTOPTS:
   1764 		case IPV6_NEXTHOP: {
   1765 			/* new advanced API (RFC3542) */
   1766 			void *optbuf;
   1767 			int optbuflen;
   1768 			struct ip6_pktopts **optp;
   1769 
   1770 #ifdef RFC2292
   1771 			/* cannot mix with RFC2292 */
   1772 			if (OPTBIT(IN6P_RFC2292)) {
   1773 				error = EINVAL;
   1774 				break;
   1775 			}
   1776 #endif
   1777 
   1778 			optbuflen = sopt->sopt_size;
   1779 			optbuf = malloc(optbuflen, M_IP6OPT, M_NOWAIT);
   1780 			if (optbuf == NULL) {
   1781 				error = ENOBUFS;
   1782 				break;
   1783 			}
   1784 
   1785 			sockopt_get(sopt, optbuf, optbuflen);
   1786 			optp = &in6p->in6p_outputopts;
   1787 			error = ip6_pcbopt(optname, optbuf, optbuflen,
   1788 			    optp, kauth_cred_get(), uproto);
   1789 			break;
   1790 			}
   1791 #undef OPTSET
   1792 
   1793 		case IPV6_MULTICAST_IF:
   1794 		case IPV6_MULTICAST_HOPS:
   1795 		case IPV6_MULTICAST_LOOP:
   1796 		case IPV6_JOIN_GROUP:
   1797 		case IPV6_LEAVE_GROUP:
   1798 			error = ip6_setmoptions(sopt, &in6p->in6p_moptions);
   1799 			break;
   1800 
   1801 		case IPV6_PORTRANGE:
   1802 			error = sockopt_getint(sopt, &optval);
   1803 			if (error)
   1804 				break;
   1805 
   1806 			switch (optval) {
   1807 			case IPV6_PORTRANGE_DEFAULT:
   1808 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1809 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1810 				break;
   1811 
   1812 			case IPV6_PORTRANGE_HIGH:
   1813 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1814 				in6p->in6p_flags |= IN6P_HIGHPORT;
   1815 				break;
   1816 
   1817 			case IPV6_PORTRANGE_LOW:
   1818 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1819 				in6p->in6p_flags |= IN6P_LOWPORT;
   1820 				break;
   1821 
   1822 			default:
   1823 				error = EINVAL;
   1824 				break;
   1825 			}
   1826 			break;
   1827 
   1828 
   1829 #if defined(KAME_IPSEC) || defined(FAST_IPSEC)
   1830 		case IPV6_IPSEC_POLICY:
   1831 			error = ipsec6_set_policy(in6p, optname,
   1832 			    sopt->sopt_data, sopt->sopt_size, kauth_cred_get());
   1833 			break;
   1834 #endif /* IPSEC */
   1835 
   1836 		default:
   1837 			error = ENOPROTOOPT;
   1838 			break;
   1839 		}
   1840 		break;
   1841 
   1842 	case PRCO_GETOPT:
   1843 		switch (optname) {
   1844 #ifdef RFC2292
   1845 		case IPV6_2292PKTOPTIONS:
   1846 			/*
   1847 			 * RFC3542 (effectively) deprecated the
   1848 			 * semantics of the 2292-style pktoptions.
   1849 			 * Since it was not reliable in nature (i.e.,
   1850 			 * applications had to expect the lack of some
   1851 			 * information after all), it would make sense
   1852 			 * to simplify this part by always returning
   1853 			 * empty data.
   1854 			 */
   1855 			break;
   1856 #endif
   1857 
   1858 		case IPV6_RECVHOPOPTS:
   1859 		case IPV6_RECVDSTOPTS:
   1860 		case IPV6_RECVRTHDRDSTOPTS:
   1861 		case IPV6_UNICAST_HOPS:
   1862 		case IPV6_RECVPKTINFO:
   1863 		case IPV6_RECVHOPLIMIT:
   1864 		case IPV6_RECVRTHDR:
   1865 		case IPV6_RECVPATHMTU:
   1866 
   1867 		case IPV6_FAITH:
   1868 		case IPV6_V6ONLY:
   1869 		case IPV6_PORTRANGE:
   1870 		case IPV6_RECVTCLASS:
   1871 			switch (optname) {
   1872 
   1873 			case IPV6_RECVHOPOPTS:
   1874 				optval = OPTBIT(IN6P_HOPOPTS);
   1875 				break;
   1876 
   1877 			case IPV6_RECVDSTOPTS:
   1878 				optval = OPTBIT(IN6P_DSTOPTS);
   1879 				break;
   1880 
   1881 			case IPV6_RECVRTHDRDSTOPTS:
   1882 				optval = OPTBIT(IN6P_RTHDRDSTOPTS);
   1883 				break;
   1884 
   1885 			case IPV6_UNICAST_HOPS:
   1886 				optval = in6p->in6p_hops;
   1887 				break;
   1888 
   1889 			case IPV6_RECVPKTINFO:
   1890 				optval = OPTBIT(IN6P_PKTINFO);
   1891 				break;
   1892 
   1893 			case IPV6_RECVHOPLIMIT:
   1894 				optval = OPTBIT(IN6P_HOPLIMIT);
   1895 				break;
   1896 
   1897 			case IPV6_RECVRTHDR:
   1898 				optval = OPTBIT(IN6P_RTHDR);
   1899 				break;
   1900 
   1901 			case IPV6_RECVPATHMTU:
   1902 				optval = OPTBIT(IN6P_MTU);
   1903 				break;
   1904 
   1905 			case IPV6_FAITH:
   1906 				optval = OPTBIT(IN6P_FAITH);
   1907 				break;
   1908 
   1909 			case IPV6_V6ONLY:
   1910 				optval = OPTBIT(IN6P_IPV6_V6ONLY);
   1911 				break;
   1912 
   1913 			case IPV6_PORTRANGE:
   1914 			    {
   1915 				int flags;
   1916 				flags = in6p->in6p_flags;
   1917 				if (flags & IN6P_HIGHPORT)
   1918 					optval = IPV6_PORTRANGE_HIGH;
   1919 				else if (flags & IN6P_LOWPORT)
   1920 					optval = IPV6_PORTRANGE_LOW;
   1921 				else
   1922 					optval = 0;
   1923 				break;
   1924 			    }
   1925 			case IPV6_RECVTCLASS:
   1926 				optval = OPTBIT(IN6P_TCLASS);
   1927 				break;
   1928 
   1929 			}
   1930 			if (error)
   1931 				break;
   1932 			error = sockopt_setint(sopt, optval);
   1933 			break;
   1934 
   1935 		case IPV6_PATHMTU:
   1936 		    {
   1937 			u_long pmtu = 0;
   1938 			struct ip6_mtuinfo mtuinfo;
   1939 			struct route *ro = &in6p->in6p_route;
   1940 
   1941 			if (!(so->so_state & SS_ISCONNECTED))
   1942 				return (ENOTCONN);
   1943 			/*
   1944 			 * XXX: we dot not consider the case of source
   1945 			 * routing, or optional information to specify
   1946 			 * the outgoing interface.
   1947 			 */
   1948 			error = ip6_getpmtu(ro, NULL, NULL,
   1949 			    &in6p->in6p_faddr, &pmtu, NULL);
   1950 			if (error)
   1951 				break;
   1952 			if (pmtu > IPV6_MAXPACKET)
   1953 				pmtu = IPV6_MAXPACKET;
   1954 
   1955 			memset(&mtuinfo, 0, sizeof(mtuinfo));
   1956 			mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
   1957 			optdata = (void *)&mtuinfo;
   1958 			optdatalen = sizeof(mtuinfo);
   1959 			if (optdatalen > MCLBYTES)
   1960 				return (EMSGSIZE); /* XXX */
   1961 			error = sockopt_set(sopt, optdata, optdatalen);
   1962 			break;
   1963 		    }
   1964 
   1965 #ifdef RFC2292
   1966 		case IPV6_2292PKTINFO:
   1967 		case IPV6_2292HOPLIMIT:
   1968 		case IPV6_2292HOPOPTS:
   1969 		case IPV6_2292RTHDR:
   1970 		case IPV6_2292DSTOPTS:
   1971 			switch (optname) {
   1972 			case IPV6_2292PKTINFO:
   1973 				optval = OPTBIT(IN6P_PKTINFO);
   1974 				break;
   1975 			case IPV6_2292HOPLIMIT:
   1976 				optval = OPTBIT(IN6P_HOPLIMIT);
   1977 				break;
   1978 			case IPV6_2292HOPOPTS:
   1979 				optval = OPTBIT(IN6P_HOPOPTS);
   1980 				break;
   1981 			case IPV6_2292RTHDR:
   1982 				optval = OPTBIT(IN6P_RTHDR);
   1983 				break;
   1984 			case IPV6_2292DSTOPTS:
   1985 				optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
   1986 				break;
   1987 			}
   1988 			error = sockopt_setint(sopt, optval);
   1989 			break;
   1990 #endif
   1991 		case IPV6_PKTINFO:
   1992 		case IPV6_HOPOPTS:
   1993 		case IPV6_RTHDR:
   1994 		case IPV6_DSTOPTS:
   1995 		case IPV6_RTHDRDSTOPTS:
   1996 		case IPV6_NEXTHOP:
   1997 		case IPV6_OTCLASS:
   1998 		case IPV6_TCLASS:
   1999 		case IPV6_DONTFRAG:
   2000 		case IPV6_USE_MIN_MTU:
   2001 			error = ip6_getpcbopt(in6p->in6p_outputopts,
   2002 			    optname, sopt);
   2003 			break;
   2004 
   2005 		case IPV6_MULTICAST_IF:
   2006 		case IPV6_MULTICAST_HOPS:
   2007 		case IPV6_MULTICAST_LOOP:
   2008 		case IPV6_JOIN_GROUP:
   2009 		case IPV6_LEAVE_GROUP:
   2010 			error = ip6_getmoptions(sopt, in6p->in6p_moptions);
   2011 			break;
   2012 
   2013 #if defined(KAME_IPSEC) || defined(FAST_IPSEC)
   2014 		case IPV6_IPSEC_POLICY:
   2015 		    {
   2016 			struct mbuf *m = NULL;
   2017 
   2018 			/* XXX this will return EINVAL as sopt is empty */
   2019 			error = ipsec6_get_policy(in6p, sopt->sopt_data,
   2020 			    sopt->sopt_size, &m);
   2021 			if (!error)
   2022 				error = sockopt_setmbuf(sopt, m);
   2023 
   2024 			break;
   2025 		    }
   2026 #endif /* IPSEC */
   2027 
   2028 		default:
   2029 			error = ENOPROTOOPT;
   2030 			break;
   2031 		}
   2032 		break;
   2033 	}
   2034 	return (error);
   2035 }
   2036 
   2037 int
   2038 ip6_raw_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   2039 {
   2040 	int error = 0, optval;
   2041 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
   2042 	struct in6pcb *in6p = sotoin6pcb(so);
   2043 	int level, optname;
   2044 
   2045 	KASSERT(sopt != NULL);
   2046 
   2047 	level = sopt->sopt_level;
   2048 	optname = sopt->sopt_name;
   2049 
   2050 	if (level != IPPROTO_IPV6) {
   2051 		return ENOPROTOOPT;
   2052 	}
   2053 
   2054 	switch (optname) {
   2055 	case IPV6_CHECKSUM:
   2056 		/*
   2057 		 * For ICMPv6 sockets, no modification allowed for checksum
   2058 		 * offset, permit "no change" values to help existing apps.
   2059 		 *
   2060 		 * XXX RFC3542 says: "An attempt to set IPV6_CHECKSUM
   2061 		 * for an ICMPv6 socket will fail."  The current
   2062 		 * behavior does not meet RFC3542.
   2063 		 */
   2064 		switch (op) {
   2065 		case PRCO_SETOPT:
   2066 			error = sockopt_getint(sopt, &optval);
   2067 			if (error)
   2068 				break;
   2069 			if ((optval % 2) != 0) {
   2070 				/* the API assumes even offset values */
   2071 				error = EINVAL;
   2072 			} else if (so->so_proto->pr_protocol ==
   2073 			    IPPROTO_ICMPV6) {
   2074 				if (optval != icmp6off)
   2075 					error = EINVAL;
   2076 			} else
   2077 				in6p->in6p_cksum = optval;
   2078 			break;
   2079 
   2080 		case PRCO_GETOPT:
   2081 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
   2082 				optval = icmp6off;
   2083 			else
   2084 				optval = in6p->in6p_cksum;
   2085 
   2086 			error = sockopt_setint(sopt, optval);
   2087 			break;
   2088 
   2089 		default:
   2090 			error = EINVAL;
   2091 			break;
   2092 		}
   2093 		break;
   2094 
   2095 	default:
   2096 		error = ENOPROTOOPT;
   2097 		break;
   2098 	}
   2099 
   2100 	return (error);
   2101 }
   2102 
   2103 #ifdef RFC2292
   2104 /*
   2105  * Set up IP6 options in pcb for insertion in output packets or
   2106  * specifying behavior of outgoing packets.
   2107  */
   2108 static int
   2109 ip6_pcbopts(struct ip6_pktopts **pktopt, struct socket *so,
   2110     struct sockopt *sopt)
   2111 {
   2112 	struct ip6_pktopts *opt = *pktopt;
   2113 	struct mbuf *m;
   2114 	int error = 0;
   2115 
   2116 	/* turn off any old options. */
   2117 	if (opt) {
   2118 #ifdef DIAGNOSTIC
   2119 	    if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
   2120 		opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
   2121 		opt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2122 		    printf("ip6_pcbopts: all specified options are cleared.\n");
   2123 #endif
   2124 		ip6_clearpktopts(opt, -1);
   2125 	} else {
   2126 		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
   2127 		if (opt == NULL)
   2128 			return (ENOBUFS);
   2129 	}
   2130 	*pktopt = NULL;
   2131 
   2132 	if (sopt == NULL || sopt->sopt_size == 0) {
   2133 		/*
   2134 		 * Only turning off any previous options, regardless of
   2135 		 * whether the opt is just created or given.
   2136 		 */
   2137 		free(opt, M_IP6OPT);
   2138 		return (0);
   2139 	}
   2140 
   2141 	/*  set options specified by user. */
   2142 	m = sockopt_getmbuf(sopt);
   2143 	if (m == NULL) {
   2144 		free(opt, M_IP6OPT);
   2145 		return (ENOBUFS);
   2146 	}
   2147 
   2148 	error = ip6_setpktopts(m, opt, NULL, kauth_cred_get(),
   2149 	    so->so_proto->pr_protocol);
   2150 	m_freem(m);
   2151 	if (error != 0) {
   2152 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
   2153 		free(opt, M_IP6OPT);
   2154 		return (error);
   2155 	}
   2156 	*pktopt = opt;
   2157 	return (0);
   2158 }
   2159 #endif
   2160 
   2161 /*
   2162  * initialize ip6_pktopts.  beware that there are non-zero default values in
   2163  * the struct.
   2164  */
   2165 void
   2166 ip6_initpktopts(struct ip6_pktopts *opt)
   2167 {
   2168 
   2169 	memset(opt, 0, sizeof(*opt));
   2170 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
   2171 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
   2172 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
   2173 }
   2174 
   2175 #define sin6tosa(sin6)	((struct sockaddr *)(sin6)) /* XXX */
   2176 static int
   2177 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
   2178     kauth_cred_t cred, int uproto)
   2179 {
   2180 	struct ip6_pktopts *opt;
   2181 
   2182 	if (*pktopt == NULL) {
   2183 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
   2184 		    M_NOWAIT);
   2185 		if (*pktopt == NULL)
   2186 			return (ENOBUFS);
   2187 
   2188 		ip6_initpktopts(*pktopt);
   2189 	}
   2190 	opt = *pktopt;
   2191 
   2192 	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
   2193 }
   2194 
   2195 static int
   2196 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
   2197 {
   2198 	void *optdata = NULL;
   2199 	int optdatalen = 0;
   2200 	struct ip6_ext *ip6e;
   2201 	int error = 0;
   2202 	struct in6_pktinfo null_pktinfo;
   2203 	int deftclass = 0, on;
   2204 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
   2205 
   2206 	switch (optname) {
   2207 	case IPV6_PKTINFO:
   2208 		if (pktopt && pktopt->ip6po_pktinfo)
   2209 			optdata = (void *)pktopt->ip6po_pktinfo;
   2210 		else {
   2211 			/* XXX: we don't have to do this every time... */
   2212 			memset(&null_pktinfo, 0, sizeof(null_pktinfo));
   2213 			optdata = (void *)&null_pktinfo;
   2214 		}
   2215 		optdatalen = sizeof(struct in6_pktinfo);
   2216 		break;
   2217 	case IPV6_OTCLASS:
   2218 		/* XXX */
   2219 		return (EINVAL);
   2220 	case IPV6_TCLASS:
   2221 		if (pktopt && pktopt->ip6po_tclass >= 0)
   2222 			optdata = (void *)&pktopt->ip6po_tclass;
   2223 		else
   2224 			optdata = (void *)&deftclass;
   2225 		optdatalen = sizeof(int);
   2226 		break;
   2227 	case IPV6_HOPOPTS:
   2228 		if (pktopt && pktopt->ip6po_hbh) {
   2229 			optdata = (void *)pktopt->ip6po_hbh;
   2230 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
   2231 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2232 		}
   2233 		break;
   2234 	case IPV6_RTHDR:
   2235 		if (pktopt && pktopt->ip6po_rthdr) {
   2236 			optdata = (void *)pktopt->ip6po_rthdr;
   2237 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
   2238 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2239 		}
   2240 		break;
   2241 	case IPV6_RTHDRDSTOPTS:
   2242 		if (pktopt && pktopt->ip6po_dest1) {
   2243 			optdata = (void *)pktopt->ip6po_dest1;
   2244 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
   2245 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2246 		}
   2247 		break;
   2248 	case IPV6_DSTOPTS:
   2249 		if (pktopt && pktopt->ip6po_dest2) {
   2250 			optdata = (void *)pktopt->ip6po_dest2;
   2251 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
   2252 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2253 		}
   2254 		break;
   2255 	case IPV6_NEXTHOP:
   2256 		if (pktopt && pktopt->ip6po_nexthop) {
   2257 			optdata = (void *)pktopt->ip6po_nexthop;
   2258 			optdatalen = pktopt->ip6po_nexthop->sa_len;
   2259 		}
   2260 		break;
   2261 	case IPV6_USE_MIN_MTU:
   2262 		if (pktopt)
   2263 			optdata = (void *)&pktopt->ip6po_minmtu;
   2264 		else
   2265 			optdata = (void *)&defminmtu;
   2266 		optdatalen = sizeof(int);
   2267 		break;
   2268 	case IPV6_DONTFRAG:
   2269 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
   2270 			on = 1;
   2271 		else
   2272 			on = 0;
   2273 		optdata = (void *)&on;
   2274 		optdatalen = sizeof(on);
   2275 		break;
   2276 	default:		/* should not happen */
   2277 #ifdef DIAGNOSTIC
   2278 		panic("ip6_getpcbopt: unexpected option\n");
   2279 #endif
   2280 		return (ENOPROTOOPT);
   2281 	}
   2282 
   2283 	error = sockopt_set(sopt, optdata, optdatalen);
   2284 
   2285 	return (error);
   2286 }
   2287 
   2288 void
   2289 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
   2290 {
   2291 	if (optname == -1 || optname == IPV6_PKTINFO) {
   2292 		if (pktopt->ip6po_pktinfo)
   2293 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
   2294 		pktopt->ip6po_pktinfo = NULL;
   2295 	}
   2296 	if (optname == -1 || optname == IPV6_HOPLIMIT)
   2297 		pktopt->ip6po_hlim = -1;
   2298 	if (optname == -1 || optname == IPV6_TCLASS)
   2299 		pktopt->ip6po_tclass = -1;
   2300 	if (optname == -1 || optname == IPV6_NEXTHOP) {
   2301 		rtcache_free(&pktopt->ip6po_nextroute);
   2302 		if (pktopt->ip6po_nexthop)
   2303 			free(pktopt->ip6po_nexthop, M_IP6OPT);
   2304 		pktopt->ip6po_nexthop = NULL;
   2305 	}
   2306 	if (optname == -1 || optname == IPV6_HOPOPTS) {
   2307 		if (pktopt->ip6po_hbh)
   2308 			free(pktopt->ip6po_hbh, M_IP6OPT);
   2309 		pktopt->ip6po_hbh = NULL;
   2310 	}
   2311 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
   2312 		if (pktopt->ip6po_dest1)
   2313 			free(pktopt->ip6po_dest1, M_IP6OPT);
   2314 		pktopt->ip6po_dest1 = NULL;
   2315 	}
   2316 	if (optname == -1 || optname == IPV6_RTHDR) {
   2317 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2318 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
   2319 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
   2320 		rtcache_free(&pktopt->ip6po_route);
   2321 	}
   2322 	if (optname == -1 || optname == IPV6_DSTOPTS) {
   2323 		if (pktopt->ip6po_dest2)
   2324 			free(pktopt->ip6po_dest2, M_IP6OPT);
   2325 		pktopt->ip6po_dest2 = NULL;
   2326 	}
   2327 }
   2328 
   2329 #define PKTOPT_EXTHDRCPY(type) 					\
   2330 do {								\
   2331 	if (src->type) {					\
   2332 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
   2333 		dst->type = malloc(hlen, M_IP6OPT, canwait);	\
   2334 		if (dst->type == NULL)				\
   2335 			goto bad;				\
   2336 		memcpy(dst->type, src->type, hlen);		\
   2337 	}							\
   2338 } while (/*CONSTCOND*/ 0)
   2339 
   2340 static int
   2341 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
   2342 {
   2343 	dst->ip6po_hlim = src->ip6po_hlim;
   2344 	dst->ip6po_tclass = src->ip6po_tclass;
   2345 	dst->ip6po_flags = src->ip6po_flags;
   2346 	if (src->ip6po_pktinfo) {
   2347 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
   2348 		    M_IP6OPT, canwait);
   2349 		if (dst->ip6po_pktinfo == NULL)
   2350 			goto bad;
   2351 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
   2352 	}
   2353 	if (src->ip6po_nexthop) {
   2354 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
   2355 		    M_IP6OPT, canwait);
   2356 		if (dst->ip6po_nexthop == NULL)
   2357 			goto bad;
   2358 		memcpy(dst->ip6po_nexthop, src->ip6po_nexthop,
   2359 		    src->ip6po_nexthop->sa_len);
   2360 	}
   2361 	PKTOPT_EXTHDRCPY(ip6po_hbh);
   2362 	PKTOPT_EXTHDRCPY(ip6po_dest1);
   2363 	PKTOPT_EXTHDRCPY(ip6po_dest2);
   2364 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
   2365 	return (0);
   2366 
   2367   bad:
   2368 	if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
   2369 	if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
   2370 	if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
   2371 	if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
   2372 	if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
   2373 	if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
   2374 
   2375 	return (ENOBUFS);
   2376 }
   2377 #undef PKTOPT_EXTHDRCPY
   2378 
   2379 struct ip6_pktopts *
   2380 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
   2381 {
   2382 	int error;
   2383 	struct ip6_pktopts *dst;
   2384 
   2385 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
   2386 	if (dst == NULL)
   2387 		return (NULL);
   2388 	ip6_initpktopts(dst);
   2389 
   2390 	if ((error = copypktopts(dst, src, canwait)) != 0) {
   2391 		free(dst, M_IP6OPT);
   2392 		return (NULL);
   2393 	}
   2394 
   2395 	return (dst);
   2396 }
   2397 
   2398 void
   2399 ip6_freepcbopts(struct ip6_pktopts *pktopt)
   2400 {
   2401 	if (pktopt == NULL)
   2402 		return;
   2403 
   2404 	ip6_clearpktopts(pktopt, -1);
   2405 
   2406 	free(pktopt, M_IP6OPT);
   2407 }
   2408 
   2409 /*
   2410  * Set the IP6 multicast options in response to user setsockopt().
   2411  */
   2412 static int
   2413 ip6_setmoptions(const struct sockopt *sopt, struct ip6_moptions **im6op)
   2414 {
   2415 	int error = 0;
   2416 	u_int loop, ifindex;
   2417 	struct ipv6_mreq mreq;
   2418 	struct ifnet *ifp;
   2419 	struct ip6_moptions *im6o = *im6op;
   2420 	struct route ro;
   2421 	struct in6_multi_mship *imm;
   2422 	struct lwp *l = curlwp;	/* XXX */
   2423 
   2424 	if (im6o == NULL) {
   2425 		/*
   2426 		 * No multicast option buffer attached to the pcb;
   2427 		 * allocate one and initialize to default values.
   2428 		 */
   2429 		im6o = malloc(sizeof(*im6o), M_IPMOPTS, M_NOWAIT);
   2430 		if (im6o == NULL)
   2431 			return (ENOBUFS);
   2432 
   2433 		*im6op = im6o;
   2434 		im6o->im6o_multicast_ifp = NULL;
   2435 		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2436 		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
   2437 		LIST_INIT(&im6o->im6o_memberships);
   2438 	}
   2439 
   2440 	switch (sopt->sopt_name) {
   2441 
   2442 	case IPV6_MULTICAST_IF:
   2443 		/*
   2444 		 * Select the interface for outgoing multicast packets.
   2445 		 */
   2446 		error = sockopt_get(sopt, &ifindex, sizeof(ifindex));
   2447 		if (error != 0)
   2448 			break;
   2449 
   2450 		if (ifindex != 0) {
   2451 			if (if_indexlim <= ifindex || !ifindex2ifnet[ifindex]) {
   2452 				error = ENXIO;	/* XXX EINVAL? */
   2453 				break;
   2454 			}
   2455 			ifp = ifindex2ifnet[ifindex];
   2456 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
   2457 				error = EADDRNOTAVAIL;
   2458 				break;
   2459 			}
   2460 		} else
   2461 			ifp = NULL;
   2462 		im6o->im6o_multicast_ifp = ifp;
   2463 		break;
   2464 
   2465 	case IPV6_MULTICAST_HOPS:
   2466 	    {
   2467 		/*
   2468 		 * Set the IP6 hoplimit for outgoing multicast packets.
   2469 		 */
   2470 		int optval;
   2471 
   2472 		error = sockopt_getint(sopt, &optval);
   2473 		if (error != 0)
   2474 			break;
   2475 
   2476 		if (optval < -1 || optval >= 256)
   2477 			error = EINVAL;
   2478 		else if (optval == -1)
   2479 			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2480 		else
   2481 			im6o->im6o_multicast_hlim = optval;
   2482 		break;
   2483 	    }
   2484 
   2485 	case IPV6_MULTICAST_LOOP:
   2486 		/*
   2487 		 * Set the loopback flag for outgoing multicast packets.
   2488 		 * Must be zero or one.
   2489 		 */
   2490 		error = sockopt_get(sopt, &loop, sizeof(loop));
   2491 		if (error != 0)
   2492 			break;
   2493 		if (loop > 1) {
   2494 			error = EINVAL;
   2495 			break;
   2496 		}
   2497 		im6o->im6o_multicast_loop = loop;
   2498 		break;
   2499 
   2500 	case IPV6_JOIN_GROUP:
   2501 		/*
   2502 		 * Add a multicast group membership.
   2503 		 * Group must be a valid IP6 multicast address.
   2504 		 */
   2505 		error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2506 		if (error != 0)
   2507 			break;
   2508 
   2509 		if (IN6_IS_ADDR_UNSPECIFIED(&mreq.ipv6mr_multiaddr)) {
   2510 			/*
   2511 			 * We use the unspecified address to specify to accept
   2512 			 * all multicast addresses. Only super user is allowed
   2513 			 * to do this.
   2514 			 */
   2515 			if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_IPV6,
   2516 			    KAUTH_REQ_NETWORK_IPV6_JOIN_MULTICAST, NULL, NULL, NULL))
   2517 			{
   2518 				error = EACCES;
   2519 				break;
   2520 			}
   2521 		} else if (!IN6_IS_ADDR_MULTICAST(&mreq.ipv6mr_multiaddr)) {
   2522 			error = EINVAL;
   2523 			break;
   2524 		}
   2525 
   2526 		/*
   2527 		 * If no interface was explicitly specified, choose an
   2528 		 * appropriate one according to the given multicast address.
   2529 		 */
   2530 		if (mreq.ipv6mr_interface == 0) {
   2531 			struct rtentry *rt;
   2532 			union {
   2533 				struct sockaddr		dst;
   2534 				struct sockaddr_in6	dst6;
   2535 			} u;
   2536 
   2537 			/*
   2538 			 * Look up the routing table for the
   2539 			 * address, and choose the outgoing interface.
   2540 			 *   XXX: is it a good approach?
   2541 			 */
   2542 			memset(&ro, 0, sizeof(ro));
   2543 			sockaddr_in6_init(&u.dst6, &mreq.ipv6mr_multiaddr, 0,
   2544 			    0, 0);
   2545 			rtcache_setdst(&ro, &u.dst);
   2546 			ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp
   2547 			                                        : NULL;
   2548 			rtcache_free(&ro);
   2549 		} else {
   2550 			/*
   2551 			 * If the interface is specified, validate it.
   2552 			 */
   2553 			if (if_indexlim <= mreq.ipv6mr_interface ||
   2554 			    !ifindex2ifnet[mreq.ipv6mr_interface]) {
   2555 				error = ENXIO;	/* XXX EINVAL? */
   2556 				break;
   2557 			}
   2558 			ifp = ifindex2ifnet[mreq.ipv6mr_interface];
   2559 		}
   2560 
   2561 		/*
   2562 		 * See if we found an interface, and confirm that it
   2563 		 * supports multicast
   2564 		 */
   2565 		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
   2566 			error = EADDRNOTAVAIL;
   2567 			break;
   2568 		}
   2569 
   2570 		if (in6_setscope(&mreq.ipv6mr_multiaddr, ifp, NULL)) {
   2571 			error = EADDRNOTAVAIL; /* XXX: should not happen */
   2572 			break;
   2573 		}
   2574 
   2575 		/*
   2576 		 * See if the membership already exists.
   2577 		 */
   2578 		for (imm = im6o->im6o_memberships.lh_first;
   2579 		     imm != NULL; imm = imm->i6mm_chain.le_next)
   2580 			if (imm->i6mm_maddr->in6m_ifp == ifp &&
   2581 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2582 			    &mreq.ipv6mr_multiaddr))
   2583 				break;
   2584 		if (imm != NULL) {
   2585 			error = EADDRINUSE;
   2586 			break;
   2587 		}
   2588 		/*
   2589 		 * Everything looks good; add a new record to the multicast
   2590 		 * address list for the given interface.
   2591 		 */
   2592 		imm = in6_joingroup(ifp, &mreq.ipv6mr_multiaddr, &error, 0);
   2593 		if (imm == NULL)
   2594 			break;
   2595 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
   2596 		break;
   2597 
   2598 	case IPV6_LEAVE_GROUP:
   2599 		/*
   2600 		 * Drop a multicast group membership.
   2601 		 * Group must be a valid IP6 multicast address.
   2602 		 */
   2603 		error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2604 		if (error != 0)
   2605 			break;
   2606 
   2607 		/*
   2608 		 * If an interface address was specified, get a pointer
   2609 		 * to its ifnet structure.
   2610 		 */
   2611 		if (mreq.ipv6mr_interface != 0) {
   2612 			if (if_indexlim <= mreq.ipv6mr_interface ||
   2613 			    !ifindex2ifnet[mreq.ipv6mr_interface]) {
   2614 				error = ENXIO;	/* XXX EINVAL? */
   2615 				break;
   2616 			}
   2617 			ifp = ifindex2ifnet[mreq.ipv6mr_interface];
   2618 		} else
   2619 			ifp = NULL;
   2620 
   2621 		/* Fill in the scope zone ID */
   2622 		if (ifp) {
   2623 			if (in6_setscope(&mreq.ipv6mr_multiaddr, ifp, NULL)) {
   2624 				/* XXX: should not happen */
   2625 				error = EADDRNOTAVAIL;
   2626 				break;
   2627 			}
   2628 		} else if (mreq.ipv6mr_interface != 0) {
   2629 			/*
   2630 			 * XXX: This case would happens when the (positive)
   2631 			 * index is in the valid range, but the corresponding
   2632 			 * interface has been detached dynamically.  The above
   2633 			 * check probably avoids such case to happen here, but
   2634 			 * we check it explicitly for safety.
   2635 			 */
   2636 			error = EADDRNOTAVAIL;
   2637 			break;
   2638 		} else {	/* ipv6mr_interface == 0 */
   2639 			struct sockaddr_in6 sa6_mc;
   2640 
   2641 			/*
   2642 			 * The API spec says as follows:
   2643 			 *  If the interface index is specified as 0, the
   2644 			 *  system may choose a multicast group membership to
   2645 			 *  drop by matching the multicast address only.
   2646 			 * On the other hand, we cannot disambiguate the scope
   2647 			 * zone unless an interface is provided.  Thus, we
   2648 			 * check if there's ambiguity with the default scope
   2649 			 * zone as the last resort.
   2650 			 */
   2651 			sockaddr_in6_init(&sa6_mc, &mreq.ipv6mr_multiaddr,
   2652 			    0, 0, 0);
   2653 			error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
   2654 			if (error != 0)
   2655 				break;
   2656 			mreq.ipv6mr_multiaddr = sa6_mc.sin6_addr;
   2657 		}
   2658 
   2659 		/*
   2660 		 * Find the membership in the membership list.
   2661 		 */
   2662 		for (imm = im6o->im6o_memberships.lh_first;
   2663 		     imm != NULL; imm = imm->i6mm_chain.le_next) {
   2664 			if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
   2665 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2666 			    &mreq.ipv6mr_multiaddr))
   2667 				break;
   2668 		}
   2669 		if (imm == NULL) {
   2670 			/* Unable to resolve interface */
   2671 			error = EADDRNOTAVAIL;
   2672 			break;
   2673 		}
   2674 		/*
   2675 		 * Give up the multicast address record to which the
   2676 		 * membership points.
   2677 		 */
   2678 		LIST_REMOVE(imm, i6mm_chain);
   2679 		in6_leavegroup(imm);
   2680 		break;
   2681 
   2682 	default:
   2683 		error = EOPNOTSUPP;
   2684 		break;
   2685 	}
   2686 
   2687 	/*
   2688 	 * If all options have default values, no need to keep the mbuf.
   2689 	 */
   2690 	if (im6o->im6o_multicast_ifp == NULL &&
   2691 	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
   2692 	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
   2693 	    im6o->im6o_memberships.lh_first == NULL) {
   2694 		free(*im6op, M_IPMOPTS);
   2695 		*im6op = NULL;
   2696 	}
   2697 
   2698 	return (error);
   2699 }
   2700 
   2701 /*
   2702  * Return the IP6 multicast options in response to user getsockopt().
   2703  */
   2704 static int
   2705 ip6_getmoptions(struct sockopt *sopt, struct ip6_moptions *im6o)
   2706 {
   2707 	u_int optval;
   2708 	int error;
   2709 
   2710 	switch (sopt->sopt_name) {
   2711 	case IPV6_MULTICAST_IF:
   2712 		if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
   2713 			optval = 0;
   2714 		else
   2715 			optval = im6o->im6o_multicast_ifp->if_index;
   2716 
   2717 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2718 		break;
   2719 
   2720 	case IPV6_MULTICAST_HOPS:
   2721 		if (im6o == NULL)
   2722 			optval = ip6_defmcasthlim;
   2723 		else
   2724 			optval = im6o->im6o_multicast_hlim;
   2725 
   2726 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2727 		break;
   2728 
   2729 	case IPV6_MULTICAST_LOOP:
   2730 		if (im6o == NULL)
   2731 			optval = ip6_defmcasthlim;
   2732 		else
   2733 			optval = im6o->im6o_multicast_loop;
   2734 
   2735 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2736 		break;
   2737 
   2738 	default:
   2739 		error = EOPNOTSUPP;
   2740 	}
   2741 
   2742 	return (error);
   2743 }
   2744 
   2745 /*
   2746  * Discard the IP6 multicast options.
   2747  */
   2748 void
   2749 ip6_freemoptions(struct ip6_moptions *im6o)
   2750 {
   2751 	struct in6_multi_mship *imm;
   2752 
   2753 	if (im6o == NULL)
   2754 		return;
   2755 
   2756 	while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
   2757 		LIST_REMOVE(imm, i6mm_chain);
   2758 		in6_leavegroup(imm);
   2759 	}
   2760 	free(im6o, M_IPMOPTS);
   2761 }
   2762 
   2763 /*
   2764  * Set IPv6 outgoing packet options based on advanced API.
   2765  */
   2766 int
   2767 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
   2768 	struct ip6_pktopts *stickyopt, kauth_cred_t cred, int uproto)
   2769 {
   2770 	struct cmsghdr *cm = 0;
   2771 
   2772 	if (control == NULL || opt == NULL)
   2773 		return (EINVAL);
   2774 
   2775 	ip6_initpktopts(opt);
   2776 	if (stickyopt) {
   2777 		int error;
   2778 
   2779 		/*
   2780 		 * If stickyopt is provided, make a local copy of the options
   2781 		 * for this particular packet, then override them by ancillary
   2782 		 * objects.
   2783 		 * XXX: copypktopts() does not copy the cached route to a next
   2784 		 * hop (if any).  This is not very good in terms of efficiency,
   2785 		 * but we can allow this since this option should be rarely
   2786 		 * used.
   2787 		 */
   2788 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
   2789 			return (error);
   2790 	}
   2791 
   2792 	/*
   2793 	 * XXX: Currently, we assume all the optional information is stored
   2794 	 * in a single mbuf.
   2795 	 */
   2796 	if (control->m_next)
   2797 		return (EINVAL);
   2798 
   2799 	/* XXX if cm->cmsg_len is not aligned, control->m_len can become <0 */
   2800 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
   2801 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
   2802 		int error;
   2803 
   2804 		if (control->m_len < CMSG_LEN(0))
   2805 			return (EINVAL);
   2806 
   2807 		cm = mtod(control, struct cmsghdr *);
   2808 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
   2809 			return (EINVAL);
   2810 		if (cm->cmsg_level != IPPROTO_IPV6)
   2811 			continue;
   2812 
   2813 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
   2814 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
   2815 		if (error)
   2816 			return (error);
   2817 	}
   2818 
   2819 	return (0);
   2820 }
   2821 
   2822 /*
   2823  * Set a particular packet option, as a sticky option or an ancillary data
   2824  * item.  "len" can be 0 only when it's a sticky option.
   2825  * We have 4 cases of combination of "sticky" and "cmsg":
   2826  * "sticky=0, cmsg=0": impossible
   2827  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
   2828  * "sticky=1, cmsg=0": RFC3542 socket option
   2829  * "sticky=1, cmsg=1": RFC2292 socket option
   2830  */
   2831 static int
   2832 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
   2833     kauth_cred_t cred, int sticky, int cmsg, int uproto)
   2834 {
   2835 	int minmtupolicy;
   2836 	int error;
   2837 
   2838 	if (!sticky && !cmsg) {
   2839 #ifdef DIAGNOSTIC
   2840 		printf("ip6_setpktopt: impossible case\n");
   2841 #endif
   2842 		return (EINVAL);
   2843 	}
   2844 
   2845 	/*
   2846 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
   2847 	 * not be specified in the context of RFC3542.  Conversely,
   2848 	 * RFC3542 types should not be specified in the context of RFC2292.
   2849 	 */
   2850 	if (!cmsg) {
   2851 		switch (optname) {
   2852 		case IPV6_2292PKTINFO:
   2853 		case IPV6_2292HOPLIMIT:
   2854 		case IPV6_2292NEXTHOP:
   2855 		case IPV6_2292HOPOPTS:
   2856 		case IPV6_2292DSTOPTS:
   2857 		case IPV6_2292RTHDR:
   2858 		case IPV6_2292PKTOPTIONS:
   2859 			return (ENOPROTOOPT);
   2860 		}
   2861 	}
   2862 	if (sticky && cmsg) {
   2863 		switch (optname) {
   2864 		case IPV6_PKTINFO:
   2865 		case IPV6_HOPLIMIT:
   2866 		case IPV6_NEXTHOP:
   2867 		case IPV6_HOPOPTS:
   2868 		case IPV6_DSTOPTS:
   2869 		case IPV6_RTHDRDSTOPTS:
   2870 		case IPV6_RTHDR:
   2871 		case IPV6_USE_MIN_MTU:
   2872 		case IPV6_DONTFRAG:
   2873 		case IPV6_OTCLASS:
   2874 		case IPV6_TCLASS:
   2875 			return (ENOPROTOOPT);
   2876 		}
   2877 	}
   2878 
   2879 	switch (optname) {
   2880 #ifdef RFC2292
   2881 	case IPV6_2292PKTINFO:
   2882 #endif
   2883 	case IPV6_PKTINFO:
   2884 	{
   2885 		struct ifnet *ifp = NULL;
   2886 		struct in6_pktinfo *pktinfo;
   2887 
   2888 		if (len != sizeof(struct in6_pktinfo))
   2889 			return (EINVAL);
   2890 
   2891 		pktinfo = (struct in6_pktinfo *)buf;
   2892 
   2893 		/*
   2894 		 * An application can clear any sticky IPV6_PKTINFO option by
   2895 		 * doing a "regular" setsockopt with ipi6_addr being
   2896 		 * in6addr_any and ipi6_ifindex being zero.
   2897 		 * [RFC 3542, Section 6]
   2898 		 */
   2899 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
   2900 		    pktinfo->ipi6_ifindex == 0 &&
   2901 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2902 			ip6_clearpktopts(opt, optname);
   2903 			break;
   2904 		}
   2905 
   2906 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
   2907 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2908 			return (EINVAL);
   2909 		}
   2910 
   2911 		/* validate the interface index if specified. */
   2912 		if (pktinfo->ipi6_ifindex >= if_indexlim) {
   2913 			 return (ENXIO);
   2914 		}
   2915 		if (pktinfo->ipi6_ifindex) {
   2916 			ifp = ifindex2ifnet[pktinfo->ipi6_ifindex];
   2917 			if (ifp == NULL)
   2918 				return (ENXIO);
   2919 		}
   2920 
   2921 		/*
   2922 		 * We store the address anyway, and let in6_selectsrc()
   2923 		 * validate the specified address.  This is because ipi6_addr
   2924 		 * may not have enough information about its scope zone, and
   2925 		 * we may need additional information (such as outgoing
   2926 		 * interface or the scope zone of a destination address) to
   2927 		 * disambiguate the scope.
   2928 		 * XXX: the delay of the validation may confuse the
   2929 		 * application when it is used as a sticky option.
   2930 		 */
   2931 		if (opt->ip6po_pktinfo == NULL) {
   2932 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
   2933 			    M_IP6OPT, M_NOWAIT);
   2934 			if (opt->ip6po_pktinfo == NULL)
   2935 				return (ENOBUFS);
   2936 		}
   2937 		memcpy(opt->ip6po_pktinfo, pktinfo, sizeof(*pktinfo));
   2938 		break;
   2939 	}
   2940 
   2941 #ifdef RFC2292
   2942 	case IPV6_2292HOPLIMIT:
   2943 #endif
   2944 	case IPV6_HOPLIMIT:
   2945 	{
   2946 		int *hlimp;
   2947 
   2948 		/*
   2949 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
   2950 		 * to simplify the ordering among hoplimit options.
   2951 		 */
   2952 		if (optname == IPV6_HOPLIMIT && sticky)
   2953 			return (ENOPROTOOPT);
   2954 
   2955 		if (len != sizeof(int))
   2956 			return (EINVAL);
   2957 		hlimp = (int *)buf;
   2958 		if (*hlimp < -1 || *hlimp > 255)
   2959 			return (EINVAL);
   2960 
   2961 		opt->ip6po_hlim = *hlimp;
   2962 		break;
   2963 	}
   2964 
   2965 	case IPV6_OTCLASS:
   2966 		if (len != sizeof(u_int8_t))
   2967 			return (EINVAL);
   2968 
   2969 		opt->ip6po_tclass = *(u_int8_t *)buf;
   2970 		break;
   2971 
   2972 	case IPV6_TCLASS:
   2973 	{
   2974 		int tclass;
   2975 
   2976 		if (len != sizeof(int))
   2977 			return (EINVAL);
   2978 		tclass = *(int *)buf;
   2979 		if (tclass < -1 || tclass > 255)
   2980 			return (EINVAL);
   2981 
   2982 		opt->ip6po_tclass = tclass;
   2983 		break;
   2984 	}
   2985 
   2986 #ifdef RFC2292
   2987 	case IPV6_2292NEXTHOP:
   2988 #endif
   2989 	case IPV6_NEXTHOP:
   2990 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   2991 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   2992 		if (error)
   2993 			return (error);
   2994 
   2995 		if (len == 0) {	/* just remove the option */
   2996 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
   2997 			break;
   2998 		}
   2999 
   3000 		/* check if cmsg_len is large enough for sa_len */
   3001 		if (len < sizeof(struct sockaddr) || len < *buf)
   3002 			return (EINVAL);
   3003 
   3004 		switch (((struct sockaddr *)buf)->sa_family) {
   3005 		case AF_INET6:
   3006 		{
   3007 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
   3008 
   3009 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
   3010 				return (EINVAL);
   3011 
   3012 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
   3013 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
   3014 				return (EINVAL);
   3015 			}
   3016 			if ((error = sa6_embedscope(sa6, ip6_use_defzone))
   3017 			    != 0) {
   3018 				return (error);
   3019 			}
   3020 			break;
   3021 		}
   3022 		case AF_LINK:	/* eventually be supported? */
   3023 		default:
   3024 			return (EAFNOSUPPORT);
   3025 		}
   3026 
   3027 		/* turn off the previous option, then set the new option. */
   3028 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3029 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
   3030 		if (opt->ip6po_nexthop == NULL)
   3031 			return (ENOBUFS);
   3032 		memcpy(opt->ip6po_nexthop, buf, *buf);
   3033 		break;
   3034 
   3035 #ifdef RFC2292
   3036 	case IPV6_2292HOPOPTS:
   3037 #endif
   3038 	case IPV6_HOPOPTS:
   3039 	{
   3040 		struct ip6_hbh *hbh;
   3041 		int hbhlen;
   3042 
   3043 		/*
   3044 		 * XXX: We don't allow a non-privileged user to set ANY HbH
   3045 		 * options, since per-option restriction has too much
   3046 		 * overhead.
   3047 		 */
   3048 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3049 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3050 		if (error)
   3051 			return (error);
   3052 
   3053 		if (len == 0) {
   3054 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3055 			break;	/* just remove the option */
   3056 		}
   3057 
   3058 		/* message length validation */
   3059 		if (len < sizeof(struct ip6_hbh))
   3060 			return (EINVAL);
   3061 		hbh = (struct ip6_hbh *)buf;
   3062 		hbhlen = (hbh->ip6h_len + 1) << 3;
   3063 		if (len != hbhlen)
   3064 			return (EINVAL);
   3065 
   3066 		/* turn off the previous option, then set the new option. */
   3067 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3068 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
   3069 		if (opt->ip6po_hbh == NULL)
   3070 			return (ENOBUFS);
   3071 		memcpy(opt->ip6po_hbh, hbh, hbhlen);
   3072 
   3073 		break;
   3074 	}
   3075 
   3076 #ifdef RFC2292
   3077 	case IPV6_2292DSTOPTS:
   3078 #endif
   3079 	case IPV6_DSTOPTS:
   3080 	case IPV6_RTHDRDSTOPTS:
   3081 	{
   3082 		struct ip6_dest *dest, **newdest = NULL;
   3083 		int destlen;
   3084 
   3085 		/* XXX: see the comment for IPV6_HOPOPTS */
   3086 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3087 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3088 		if (error)
   3089 			return (error);
   3090 
   3091 		if (len == 0) {
   3092 			ip6_clearpktopts(opt, optname);
   3093 			break;	/* just remove the option */
   3094 		}
   3095 
   3096 		/* message length validation */
   3097 		if (len < sizeof(struct ip6_dest))
   3098 			return (EINVAL);
   3099 		dest = (struct ip6_dest *)buf;
   3100 		destlen = (dest->ip6d_len + 1) << 3;
   3101 		if (len != destlen)
   3102 			return (EINVAL);
   3103 		/*
   3104 		 * Determine the position that the destination options header
   3105 		 * should be inserted; before or after the routing header.
   3106 		 */
   3107 		switch (optname) {
   3108 		case IPV6_2292DSTOPTS:
   3109 			/*
   3110 			 * The old advanced API is ambiguous on this point.
   3111 			 * Our approach is to determine the position based
   3112 			 * according to the existence of a routing header.
   3113 			 * Note, however, that this depends on the order of the
   3114 			 * extension headers in the ancillary data; the 1st
   3115 			 * part of the destination options header must appear
   3116 			 * before the routing header in the ancillary data,
   3117 			 * too.
   3118 			 * RFC3542 solved the ambiguity by introducing
   3119 			 * separate ancillary data or option types.
   3120 			 */
   3121 			if (opt->ip6po_rthdr == NULL)
   3122 				newdest = &opt->ip6po_dest1;
   3123 			else
   3124 				newdest = &opt->ip6po_dest2;
   3125 			break;
   3126 		case IPV6_RTHDRDSTOPTS:
   3127 			newdest = &opt->ip6po_dest1;
   3128 			break;
   3129 		case IPV6_DSTOPTS:
   3130 			newdest = &opt->ip6po_dest2;
   3131 			break;
   3132 		}
   3133 
   3134 		/* turn off the previous option, then set the new option. */
   3135 		ip6_clearpktopts(opt, optname);
   3136 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
   3137 		if (*newdest == NULL)
   3138 			return (ENOBUFS);
   3139 		memcpy(*newdest, dest, destlen);
   3140 
   3141 		break;
   3142 	}
   3143 
   3144 #ifdef RFC2292
   3145 	case IPV6_2292RTHDR:
   3146 #endif
   3147 	case IPV6_RTHDR:
   3148 	{
   3149 		struct ip6_rthdr *rth;
   3150 		int rthlen;
   3151 
   3152 		if (len == 0) {
   3153 			ip6_clearpktopts(opt, IPV6_RTHDR);
   3154 			break;	/* just remove the option */
   3155 		}
   3156 
   3157 		/* message length validation */
   3158 		if (len < sizeof(struct ip6_rthdr))
   3159 			return (EINVAL);
   3160 		rth = (struct ip6_rthdr *)buf;
   3161 		rthlen = (rth->ip6r_len + 1) << 3;
   3162 		if (len != rthlen)
   3163 			return (EINVAL);
   3164 		switch (rth->ip6r_type) {
   3165 		case IPV6_RTHDR_TYPE_0:
   3166 			if (rth->ip6r_len == 0)	/* must contain one addr */
   3167 				return (EINVAL);
   3168 			if (rth->ip6r_len % 2) /* length must be even */
   3169 				return (EINVAL);
   3170 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
   3171 				return (EINVAL);
   3172 			break;
   3173 		default:
   3174 			return (EINVAL);	/* not supported */
   3175 		}
   3176 		/* turn off the previous option */
   3177 		ip6_clearpktopts(opt, IPV6_RTHDR);
   3178 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
   3179 		if (opt->ip6po_rthdr == NULL)
   3180 			return (ENOBUFS);
   3181 		memcpy(opt->ip6po_rthdr, rth, rthlen);
   3182 		break;
   3183 	}
   3184 
   3185 	case IPV6_USE_MIN_MTU:
   3186 		if (len != sizeof(int))
   3187 			return (EINVAL);
   3188 		minmtupolicy = *(int *)buf;
   3189 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
   3190 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
   3191 		    minmtupolicy != IP6PO_MINMTU_ALL) {
   3192 			return (EINVAL);
   3193 		}
   3194 		opt->ip6po_minmtu = minmtupolicy;
   3195 		break;
   3196 
   3197 	case IPV6_DONTFRAG:
   3198 		if (len != sizeof(int))
   3199 			return (EINVAL);
   3200 
   3201 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
   3202 			/*
   3203 			 * we ignore this option for TCP sockets.
   3204 			 * (RFC3542 leaves this case unspecified.)
   3205 			 */
   3206 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
   3207 		} else
   3208 			opt->ip6po_flags |= IP6PO_DONTFRAG;
   3209 		break;
   3210 
   3211 	default:
   3212 		return (ENOPROTOOPT);
   3213 	} /* end of switch */
   3214 
   3215 	return (0);
   3216 }
   3217 
   3218 /*
   3219  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
   3220  * packet to the input queue of a specified interface.  Note that this
   3221  * calls the output routine of the loopback "driver", but with an interface
   3222  * pointer that might NOT be lo0ifp -- easier than replicating that code here.
   3223  */
   3224 void
   3225 ip6_mloopback(struct ifnet *ifp, struct mbuf *m,
   3226 	const struct sockaddr_in6 *dst)
   3227 {
   3228 	struct mbuf *copym;
   3229 	struct ip6_hdr *ip6;
   3230 
   3231 	copym = m_copy(m, 0, M_COPYALL);
   3232 	if (copym == NULL)
   3233 		return;
   3234 
   3235 	/*
   3236 	 * Make sure to deep-copy IPv6 header portion in case the data
   3237 	 * is in an mbuf cluster, so that we can safely override the IPv6
   3238 	 * header portion later.
   3239 	 */
   3240 	if ((copym->m_flags & M_EXT) != 0 ||
   3241 	    copym->m_len < sizeof(struct ip6_hdr)) {
   3242 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
   3243 		if (copym == NULL)
   3244 			return;
   3245 	}
   3246 
   3247 #ifdef DIAGNOSTIC
   3248 	if (copym->m_len < sizeof(*ip6)) {
   3249 		m_freem(copym);
   3250 		return;
   3251 	}
   3252 #endif
   3253 
   3254 	ip6 = mtod(copym, struct ip6_hdr *);
   3255 	/*
   3256 	 * clear embedded scope identifiers if necessary.
   3257 	 * in6_clearscope will touch the addresses only when necessary.
   3258 	 */
   3259 	in6_clearscope(&ip6->ip6_src);
   3260 	in6_clearscope(&ip6->ip6_dst);
   3261 
   3262 	(void)looutput(ifp, copym, (const struct sockaddr *)dst, NULL);
   3263 }
   3264 
   3265 /*
   3266  * Chop IPv6 header off from the payload.
   3267  */
   3268 static int
   3269 ip6_splithdr(struct mbuf *m,  struct ip6_exthdrs *exthdrs)
   3270 {
   3271 	struct mbuf *mh;
   3272 	struct ip6_hdr *ip6;
   3273 
   3274 	ip6 = mtod(m, struct ip6_hdr *);
   3275 	if (m->m_len > sizeof(*ip6)) {
   3276 		MGETHDR(mh, M_DONTWAIT, MT_HEADER);
   3277 		if (mh == 0) {
   3278 			m_freem(m);
   3279 			return ENOBUFS;
   3280 		}
   3281 		M_MOVE_PKTHDR(mh, m);
   3282 		MH_ALIGN(mh, sizeof(*ip6));
   3283 		m->m_len -= sizeof(*ip6);
   3284 		m->m_data += sizeof(*ip6);
   3285 		mh->m_next = m;
   3286 		m = mh;
   3287 		m->m_len = sizeof(*ip6);
   3288 		bcopy((void *)ip6, mtod(m, void *), sizeof(*ip6));
   3289 	}
   3290 	exthdrs->ip6e_ip6 = m;
   3291 	return 0;
   3292 }
   3293 
   3294 /*
   3295  * Compute IPv6 extension header length.
   3296  */
   3297 int
   3298 ip6_optlen(struct in6pcb *in6p)
   3299 {
   3300 	int len;
   3301 
   3302 	if (!in6p->in6p_outputopts)
   3303 		return 0;
   3304 
   3305 	len = 0;
   3306 #define elen(x) \
   3307     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
   3308 
   3309 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
   3310 	len += elen(in6p->in6p_outputopts->ip6po_dest1);
   3311 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
   3312 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
   3313 	return len;
   3314 #undef elen
   3315 }
   3316