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ip6_output.c revision 1.122
      1 /*	$NetBSD: ip6_output.c,v 1.122 2007/11/01 20:33:57 dyoung 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 1.122 2007/11/01 20:33:57 dyoung 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/in6_pcb.h>
     97 #include <netinet6/nd6.h>
     98 #include <netinet6/ip6protosw.h>
     99 #include <netinet6/scope6_var.h>
    100 
    101 #ifdef IPSEC
    102 #include <netinet6/ipsec.h>
    103 #include <netkey/key.h>
    104 #endif /* IPSEC */
    105 
    106 #ifdef FAST_IPSEC
    107 #include <netipsec/ipsec.h>
    108 #include <netipsec/ipsec6.h>
    109 #include <netipsec/key.h>
    110 #include <netipsec/xform.h>
    111 #endif
    112 
    113 
    114 #include <net/net_osdep.h>
    115 
    116 #ifdef PFIL_HOOKS
    117 extern struct pfil_head inet6_pfil_hook;	/* XXX */
    118 #endif
    119 
    120 struct ip6_exthdrs {
    121 	struct mbuf *ip6e_ip6;
    122 	struct mbuf *ip6e_hbh;
    123 	struct mbuf *ip6e_dest1;
    124 	struct mbuf *ip6e_rthdr;
    125 	struct mbuf *ip6e_dest2;
    126 };
    127 
    128 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
    129 	int, int);
    130 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct mbuf **);
    131 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *, int,
    132 	int, int, int);
    133 static int ip6_setmoptions(int, struct ip6_moptions **, struct mbuf *);
    134 static int ip6_getmoptions(int, struct ip6_moptions *, struct mbuf **);
    135 static int ip6_copyexthdr(struct mbuf **, void *, int);
    136 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
    137 	struct ip6_frag **);
    138 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
    139 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
    140 static int ip6_getpmtu(struct route *, struct route *, struct ifnet *,
    141     const struct in6_addr *, u_long *, int *);
    142 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
    143 
    144 #ifdef RFC2292
    145 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
    146 	struct socket *);
    147 #endif
    148 
    149 #define	IN6_NEED_CHECKSUM(ifp, csum_flags) \
    150 	(__predict_true(((ifp)->if_flags & IFF_LOOPBACK) == 0 || \
    151 	(((csum_flags) & M_CSUM_UDPv6) != 0 && udp_do_loopback_cksum) || \
    152 	(((csum_flags) & M_CSUM_TCPv6) != 0 && tcp_do_loopback_cksum)))
    153 
    154 /*
    155  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
    156  * header (with pri, len, nxt, hlim, src, dst).
    157  * This function may modify ver and hlim only.
    158  * The mbuf chain containing the packet will be freed.
    159  * The mbuf opt, if present, will not be freed.
    160  *
    161  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
    162  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
    163  * which is rt_rmx.rmx_mtu.
    164  */
    165 int
    166 ip6_output(
    167     struct mbuf *m0,
    168     struct ip6_pktopts *opt,
    169     struct route *ro,
    170     int flags,
    171     struct ip6_moptions *im6o,
    172     struct socket *so,
    173     struct ifnet **ifpp		/* XXX: just for statistics */
    174 )
    175 {
    176 	struct ip6_hdr *ip6, *mhip6;
    177 	struct ifnet *ifp, *origifp;
    178 	struct mbuf *m = m0;
    179 	int hlen, tlen, len, off;
    180 	bool tso;
    181 	struct route ip6route;
    182 	struct rtentry *rt = NULL;
    183 	const struct sockaddr_in6 *dst = NULL;
    184 	struct sockaddr_in6 src_sa, dst_sa;
    185 	int error = 0;
    186 	struct in6_ifaddr *ia = NULL;
    187 	u_long mtu;
    188 	int alwaysfrag, dontfrag;
    189 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
    190 	struct ip6_exthdrs exthdrs;
    191 	struct in6_addr finaldst, src0, dst0;
    192 	u_int32_t zone;
    193 	struct route *ro_pmtu = NULL;
    194 	int hdrsplit = 0;
    195 	int needipsec = 0;
    196 #ifdef IPSEC
    197 	int needipsectun = 0;
    198 	struct secpolicy *sp = NULL;
    199 
    200 	ip6 = mtod(m, struct ip6_hdr *);
    201 #endif /* IPSEC */
    202 #ifdef FAST_IPSEC
    203 	struct secpolicy *sp = NULL;
    204 	int s;
    205 #endif
    206 
    207 
    208 #ifdef  DIAGNOSTIC
    209 	if ((m->m_flags & M_PKTHDR) == 0)
    210 		panic("ip6_output: no HDR");
    211 
    212 	if ((m->m_pkthdr.csum_flags &
    213 	    (M_CSUM_TCPv4|M_CSUM_UDPv4|M_CSUM_TSOv4)) != 0) {
    214 		panic("ip6_output: IPv4 checksum offload flags: %d",
    215 		    m->m_pkthdr.csum_flags);
    216 	}
    217 
    218 	if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) ==
    219 	    (M_CSUM_TCPv6|M_CSUM_UDPv6)) {
    220 		panic("ip6_output: conflicting checksum offload flags: %d",
    221 		    m->m_pkthdr.csum_flags);
    222 	}
    223 #endif
    224 
    225 	M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data, sizeof(struct ip6_hdr));
    226 
    227 #define MAKE_EXTHDR(hp, mp)						\
    228     do {								\
    229 	if (hp) {							\
    230 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
    231 		error = ip6_copyexthdr((mp), (void *)(hp), 		\
    232 		    ((eh)->ip6e_len + 1) << 3);				\
    233 		if (error)						\
    234 			goto freehdrs;					\
    235 	}								\
    236     } while (/*CONSTCOND*/ 0)
    237 
    238 	bzero(&exthdrs, sizeof(exthdrs));
    239 	if (opt) {
    240 		/* Hop-by-Hop options header */
    241 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
    242 		/* Destination options header(1st part) */
    243 		MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
    244 		/* Routing header */
    245 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
    246 		/* Destination options header(2nd part) */
    247 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
    248 	}
    249 
    250 #ifdef IPSEC
    251 	if ((flags & IPV6_FORWARDING) != 0) {
    252 		needipsec = 0;
    253 		goto skippolicycheck;
    254 	}
    255 
    256 	/* get a security policy for this packet */
    257 	if (so == NULL)
    258 		sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
    259 	else {
    260 		if (IPSEC_PCB_SKIP_IPSEC(sotoinpcb_hdr(so)->inph_sp,
    261 					 IPSEC_DIR_OUTBOUND)) {
    262 			needipsec = 0;
    263 			goto skippolicycheck;
    264 		}
    265 		sp = ipsec6_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
    266 	}
    267 
    268 	if (sp == NULL) {
    269 		ipsec6stat.out_inval++;
    270 		goto freehdrs;
    271 	}
    272 
    273 	error = 0;
    274 
    275 	/* check policy */
    276 	switch (sp->policy) {
    277 	case IPSEC_POLICY_DISCARD:
    278 		/*
    279 		 * This packet is just discarded.
    280 		 */
    281 		ipsec6stat.out_polvio++;
    282 		goto freehdrs;
    283 
    284 	case IPSEC_POLICY_BYPASS:
    285 	case IPSEC_POLICY_NONE:
    286 		/* no need to do IPsec. */
    287 		needipsec = 0;
    288 		break;
    289 
    290 	case IPSEC_POLICY_IPSEC:
    291 		if (sp->req == NULL) {
    292 			/* XXX should be panic ? */
    293 			printf("ip6_output: No IPsec request specified.\n");
    294 			error = EINVAL;
    295 			goto freehdrs;
    296 		}
    297 		needipsec = 1;
    298 		break;
    299 
    300 	case IPSEC_POLICY_ENTRUST:
    301 	default:
    302 		printf("ip6_output: Invalid policy found. %d\n", sp->policy);
    303 	}
    304 
    305   skippolicycheck:;
    306 #endif /* IPSEC */
    307 
    308 	/*
    309 	 * Calculate the total length of the extension header chain.
    310 	 * Keep the length of the unfragmentable part for fragmentation.
    311 	 */
    312 	optlen = 0;
    313 	if (exthdrs.ip6e_hbh) optlen += exthdrs.ip6e_hbh->m_len;
    314 	if (exthdrs.ip6e_dest1) optlen += exthdrs.ip6e_dest1->m_len;
    315 	if (exthdrs.ip6e_rthdr) optlen += exthdrs.ip6e_rthdr->m_len;
    316 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
    317 	/* NOTE: we don't add AH/ESP length here. do that later. */
    318 	if (exthdrs.ip6e_dest2) optlen += exthdrs.ip6e_dest2->m_len;
    319 
    320 #ifdef FAST_IPSEC
    321 	/* Check the security policy (SP) for the packet */
    322 
    323 	/* XXX For moment, we doesn't support packet with extented action */
    324 	if (optlen !=0)
    325 		goto freehdrs;
    326 
    327 	sp = ipsec6_check_policy(m,so,flags,&needipsec,&error);
    328 	if (error != 0) {
    329 		/*
    330 		 * Hack: -EINVAL is used to signal that a packet
    331 		 * should be silently discarded.  This is typically
    332 		 * because we asked key management for an SA and
    333 		 * it was delayed (e.g. kicked up to IKE).
    334 		 */
    335 	if (error == -EINVAL)
    336 		error = 0;
    337 	goto freehdrs;
    338     }
    339 #endif /* FAST_IPSEC */
    340 
    341 
    342 	if (needipsec &&
    343 	    (m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    344 		in6_delayed_cksum(m);
    345 		m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    346 	}
    347 
    348 
    349 	/*
    350 	 * If we need IPsec, or there is at least one extension header,
    351 	 * separate IP6 header from the payload.
    352 	 */
    353 	if ((needipsec || optlen) && !hdrsplit) {
    354 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    355 			m = NULL;
    356 			goto freehdrs;
    357 		}
    358 		m = exthdrs.ip6e_ip6;
    359 		hdrsplit++;
    360 	}
    361 
    362 	/* adjust pointer */
    363 	ip6 = mtod(m, struct ip6_hdr *);
    364 
    365 	/* adjust mbuf packet header length */
    366 	m->m_pkthdr.len += optlen;
    367 	plen = m->m_pkthdr.len - sizeof(*ip6);
    368 
    369 	/* If this is a jumbo payload, insert a jumbo payload option. */
    370 	if (plen > IPV6_MAXPACKET) {
    371 		if (!hdrsplit) {
    372 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    373 				m = NULL;
    374 				goto freehdrs;
    375 			}
    376 			m = exthdrs.ip6e_ip6;
    377 			hdrsplit++;
    378 		}
    379 		/* adjust pointer */
    380 		ip6 = mtod(m, struct ip6_hdr *);
    381 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
    382 			goto freehdrs;
    383 		optlen += 8; /* XXX JUMBOOPTLEN */
    384 		ip6->ip6_plen = 0;
    385 	} else
    386 		ip6->ip6_plen = htons(plen);
    387 
    388 	/*
    389 	 * Concatenate headers and fill in next header fields.
    390 	 * Here we have, on "m"
    391 	 *	IPv6 payload
    392 	 * and we insert headers accordingly.  Finally, we should be getting:
    393 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
    394 	 *
    395 	 * during the header composing process, "m" points to IPv6 header.
    396 	 * "mprev" points to an extension header prior to esp.
    397 	 */
    398 	{
    399 		u_char *nexthdrp = &ip6->ip6_nxt;
    400 		struct mbuf *mprev = m;
    401 
    402 		/*
    403 		 * we treat dest2 specially.  this makes IPsec processing
    404 		 * much easier.  the goal here is to make mprev point the
    405 		 * mbuf prior to dest2.
    406 		 *
    407 		 * result: IPv6 dest2 payload
    408 		 * m and mprev will point to IPv6 header.
    409 		 */
    410 		if (exthdrs.ip6e_dest2) {
    411 			if (!hdrsplit)
    412 				panic("assumption failed: hdr not split");
    413 			exthdrs.ip6e_dest2->m_next = m->m_next;
    414 			m->m_next = exthdrs.ip6e_dest2;
    415 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
    416 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
    417 		}
    418 
    419 #define MAKE_CHAIN(m, mp, p, i)\
    420     do {\
    421 	if (m) {\
    422 		if (!hdrsplit) \
    423 			panic("assumption failed: hdr not split"); \
    424 		*mtod((m), u_char *) = *(p);\
    425 		*(p) = (i);\
    426 		p = mtod((m), u_char *);\
    427 		(m)->m_next = (mp)->m_next;\
    428 		(mp)->m_next = (m);\
    429 		(mp) = (m);\
    430 	}\
    431     } while (/*CONSTCOND*/ 0)
    432 		/*
    433 		 * result: IPv6 hbh dest1 rthdr dest2 payload
    434 		 * m will point to IPv6 header.  mprev will point to the
    435 		 * extension header prior to dest2 (rthdr in the above case).
    436 		 */
    437 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
    438 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
    439 		    IPPROTO_DSTOPTS);
    440 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
    441 		    IPPROTO_ROUTING);
    442 
    443 		M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data,
    444 		    sizeof(struct ip6_hdr) + optlen);
    445 
    446 #ifdef IPSEC
    447 		if (!needipsec)
    448 			goto skip_ipsec2;
    449 
    450 		/*
    451 		 * pointers after IPsec headers are not valid any more.
    452 		 * other pointers need a great care too.
    453 		 * (IPsec routines should not mangle mbufs prior to AH/ESP)
    454 		 */
    455 		exthdrs.ip6e_dest2 = NULL;
    456 
    457 	    {
    458 		struct ip6_rthdr *rh = NULL;
    459 		int segleft_org = 0;
    460 		struct ipsec_output_state state;
    461 
    462 		if (exthdrs.ip6e_rthdr) {
    463 			rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
    464 			segleft_org = rh->ip6r_segleft;
    465 			rh->ip6r_segleft = 0;
    466 		}
    467 
    468 		bzero(&state, sizeof(state));
    469 		state.m = m;
    470 		error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
    471 		    &needipsectun);
    472 		m = state.m;
    473 		if (error) {
    474 			rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
    475 			/* mbuf is already reclaimed in ipsec6_output_trans. */
    476 			m = NULL;
    477 			switch (error) {
    478 			case EHOSTUNREACH:
    479 			case ENETUNREACH:
    480 			case EMSGSIZE:
    481 			case ENOBUFS:
    482 			case ENOMEM:
    483 				break;
    484 			default:
    485 				printf("ip6_output (ipsec): error code %d\n", error);
    486 				/* FALLTHROUGH */
    487 			case ENOENT:
    488 				/* don't show these error codes to the user */
    489 				error = 0;
    490 				break;
    491 			}
    492 			goto bad;
    493 		}
    494 		if (exthdrs.ip6e_rthdr) {
    495 			/* ah6_output doesn't modify mbuf chain */
    496 			rh->ip6r_segleft = segleft_org;
    497 		}
    498 	    }
    499 skip_ipsec2:;
    500 #endif
    501 	}
    502 
    503 	/*
    504 	 * If there is a routing header, replace destination address field
    505 	 * with the first hop of the routing header.
    506 	 */
    507 	if (exthdrs.ip6e_rthdr) {
    508 		struct ip6_rthdr *rh;
    509 		struct ip6_rthdr0 *rh0;
    510 		struct in6_addr *addr;
    511 		struct sockaddr_in6 sa;
    512 
    513 		rh = (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
    514 		    struct ip6_rthdr *));
    515 		finaldst = ip6->ip6_dst;
    516 		switch (rh->ip6r_type) {
    517 		case IPV6_RTHDR_TYPE_0:
    518 			 rh0 = (struct ip6_rthdr0 *)rh;
    519 			 addr = (struct in6_addr *)(rh0 + 1);
    520 
    521 			 /*
    522 			  * construct a sockaddr_in6 form of
    523 			  * the first hop.
    524 			  *
    525 			  * XXX: we may not have enough
    526 			  * information about its scope zone;
    527 			  * there is no standard API to pass
    528 			  * the information from the
    529 			  * application.
    530 			  */
    531 			 bzero(&sa, sizeof(sa));
    532 			 sa.sin6_family = AF_INET6;
    533 			 sa.sin6_len = sizeof(sa);
    534 			 sa.sin6_addr = addr[0];
    535 			 if ((error = sa6_embedscope(&sa,
    536 			     ip6_use_defzone)) != 0) {
    537 				 goto bad;
    538 			 }
    539 			 ip6->ip6_dst = sa.sin6_addr;
    540 			 (void)memmove(&addr[0], &addr[1],
    541 			     sizeof(struct in6_addr) *
    542 			     (rh0->ip6r0_segleft - 1));
    543 			 addr[rh0->ip6r0_segleft - 1] = finaldst;
    544 			 /* XXX */
    545 			 in6_clearscope(addr + rh0->ip6r0_segleft - 1);
    546 			 break;
    547 		default:	/* is it possible? */
    548 			 error = EINVAL;
    549 			 goto bad;
    550 		}
    551 	}
    552 
    553 	/* Source address validation */
    554 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
    555 	    (flags & IPV6_UNSPECSRC) == 0) {
    556 		error = EOPNOTSUPP;
    557 		ip6stat.ip6s_badscope++;
    558 		goto bad;
    559 	}
    560 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
    561 		error = EOPNOTSUPP;
    562 		ip6stat.ip6s_badscope++;
    563 		goto bad;
    564 	}
    565 
    566 	ip6stat.ip6s_localout++;
    567 
    568 	/*
    569 	 * Route packet.
    570 	 */
    571 	/* initialize cached route */
    572 	if (ro == NULL) {
    573 		memset(&ip6route, 0, sizeof(ip6route));
    574 		ro = &ip6route;
    575 	}
    576 	ro_pmtu = ro;
    577 	if (opt && opt->ip6po_rthdr)
    578 		ro = &opt->ip6po_route;
    579 
    580  	/*
    581 	 * if specified, try to fill in the traffic class field.
    582 	 * do not override if a non-zero value is already set.
    583 	 * we check the diffserv field and the ecn field separately.
    584 	 */
    585 	if (opt && opt->ip6po_tclass >= 0) {
    586 		int mask = 0;
    587 
    588 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
    589 			mask |= 0xfc;
    590 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
    591 			mask |= 0x03;
    592 		if (mask != 0)
    593 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
    594 	}
    595 
    596 	/* fill in or override the hop limit field, if necessary. */
    597 	if (opt && opt->ip6po_hlim != -1)
    598 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
    599 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    600 		if (im6o != NULL)
    601 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
    602 		else
    603 			ip6->ip6_hlim = ip6_defmcasthlim;
    604 	}
    605 
    606 #ifdef IPSEC
    607 	if (needipsec && needipsectun) {
    608 		struct ipsec_output_state state;
    609 
    610 		/*
    611 		 * All the extension headers will become inaccessible
    612 		 * (since they can be encrypted).
    613 		 * Don't panic, we need no more updates to extension headers
    614 		 * on inner IPv6 packet (since they are now encapsulated).
    615 		 *
    616 		 * IPv6 [ESP|AH] IPv6 [extension headers] payload
    617 		 */
    618 		bzero(&exthdrs, sizeof(exthdrs));
    619 		exthdrs.ip6e_ip6 = m;
    620 
    621 		bzero(&state, sizeof(state));
    622 		state.m = m;
    623 		state.ro = ro;
    624 		state.dst = rtcache_getdst(ro);
    625 
    626 		error = ipsec6_output_tunnel(&state, sp, flags);
    627 
    628 		m = state.m;
    629 		ro_pmtu = ro = state.ro;
    630 		dst = satocsin6(state.dst);
    631 		if (error) {
    632 			/* mbuf is already reclaimed in ipsec6_output_tunnel. */
    633 			m0 = m = NULL;
    634 			m = NULL;
    635 			switch (error) {
    636 			case EHOSTUNREACH:
    637 			case ENETUNREACH:
    638 			case EMSGSIZE:
    639 			case ENOBUFS:
    640 			case ENOMEM:
    641 				break;
    642 			default:
    643 				printf("ip6_output (ipsec): error code %d\n", error);
    644 				/* FALLTHROUGH */
    645 			case ENOENT:
    646 				/* don't show these error codes to the user */
    647 				error = 0;
    648 				break;
    649 			}
    650 			goto bad;
    651 		}
    652 
    653 		exthdrs.ip6e_ip6 = m;
    654 	}
    655 #endif /* IPSEC */
    656 #ifdef FAST_IPSEC
    657 	if (needipsec) {
    658 		s = splsoftnet();
    659 		error = ipsec6_process_packet(m,sp->req);
    660 
    661 		/*
    662 		 * Preserve KAME behaviour: ENOENT can be returned
    663 		 * when an SA acquire is in progress.  Don't propagate
    664 		 * this to user-level; it confuses applications.
    665 		 * XXX this will go away when the SADB is redone.
    666 		 */
    667 		if (error == ENOENT)
    668 			error = 0;
    669 		splx(s);
    670 		goto done;
    671 	}
    672 #endif /* FAST_IPSEC */
    673 
    674 
    675 
    676 	/* adjust pointer */
    677 	ip6 = mtod(m, struct ip6_hdr *);
    678 
    679 	bzero(&dst_sa, sizeof(dst_sa));
    680 	dst_sa.sin6_family = AF_INET6;
    681 	dst_sa.sin6_len = sizeof(dst_sa);
    682 	dst_sa.sin6_addr = ip6->ip6_dst;
    683 	if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
    684 	    &ifp, &rt, 0)) != 0) {
    685 		if (ifp != NULL)
    686 			in6_ifstat_inc(ifp, ifs6_out_discard);
    687 		goto bad;
    688 	}
    689 	if (rt == NULL) {
    690 		/*
    691 		 * If in6_selectroute() does not return a route entry,
    692 		 * dst may not have been updated.
    693 		 */
    694 		rtcache_setdst(ro, sin6tosa(&dst_sa));
    695 	}
    696 
    697 	/*
    698 	 * then rt (for unicast) and ifp must be non-NULL valid values.
    699 	 */
    700 	if ((flags & IPV6_FORWARDING) == 0) {
    701 		/* XXX: the FORWARDING flag can be set for mrouting. */
    702 		in6_ifstat_inc(ifp, ifs6_out_request);
    703 	}
    704 	if (rt != NULL) {
    705 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
    706 		rt->rt_use++;
    707 	}
    708 
    709 	/*
    710 	 * The outgoing interface must be in the zone of source and
    711 	 * destination addresses.  We should use ia_ifp to support the
    712 	 * case of sending packets to an address of our own.
    713 	 */
    714 	if (ia != NULL && ia->ia_ifp)
    715 		origifp = ia->ia_ifp;
    716 	else
    717 		origifp = ifp;
    718 
    719 	src0 = ip6->ip6_src;
    720 	if (in6_setscope(&src0, origifp, &zone))
    721 		goto badscope;
    722 	bzero(&src_sa, sizeof(src_sa));
    723 	src_sa.sin6_family = AF_INET6;
    724 	src_sa.sin6_len = sizeof(src_sa);
    725 	src_sa.sin6_addr = ip6->ip6_src;
    726 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
    727 		goto badscope;
    728 
    729 	dst0 = ip6->ip6_dst;
    730 	if (in6_setscope(&dst0, origifp, &zone))
    731 		goto badscope;
    732 	/* re-initialize to be sure */
    733 	bzero(&dst_sa, sizeof(dst_sa));
    734 	dst_sa.sin6_family = AF_INET6;
    735 	dst_sa.sin6_len = sizeof(dst_sa);
    736 	dst_sa.sin6_addr = ip6->ip6_dst;
    737 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id)
    738 		goto badscope;
    739 
    740 	/* scope check is done. */
    741 
    742 	if (rt == NULL || IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    743 		if (dst == NULL)
    744 			dst = satocsin6(rtcache_getdst(ro));
    745 		KASSERT(dst != NULL);
    746 	} else if (opt && opt->ip6po_nextroute.ro_rt != NULL) {
    747 		/*
    748 		 * The nexthop is explicitly specified by the
    749 		 * application.  We assume the next hop is an IPv6
    750 		 * address.
    751 		 */
    752 		dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
    753 	} else if ((rt->rt_flags & RTF_GATEWAY))
    754 		dst = (struct sockaddr_in6 *)rt->rt_gateway;
    755 	else if (dst == NULL)
    756 		dst = satocsin6(rtcache_getdst(ro));
    757 
    758 	/*
    759 	 * XXXXXX: original code follows:
    760 	 */
    761 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
    762 		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
    763 	else {
    764 		struct	in6_multi *in6m;
    765 
    766 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
    767 
    768 		in6_ifstat_inc(ifp, ifs6_out_mcast);
    769 
    770 		/*
    771 		 * Confirm that the outgoing interface supports multicast.
    772 		 */
    773 		if (!(ifp->if_flags & IFF_MULTICAST)) {
    774 			ip6stat.ip6s_noroute++;
    775 			in6_ifstat_inc(ifp, ifs6_out_discard);
    776 			error = ENETUNREACH;
    777 			goto bad;
    778 		}
    779 
    780 		IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
    781 		if (in6m != NULL &&
    782 		   (im6o == NULL || im6o->im6o_multicast_loop)) {
    783 			/*
    784 			 * If we belong to the destination multicast group
    785 			 * on the outgoing interface, and the caller did not
    786 			 * forbid loopback, loop back a copy.
    787 			 */
    788 			KASSERT(dst != NULL);
    789 			ip6_mloopback(ifp, m, dst);
    790 		} else {
    791 			/*
    792 			 * If we are acting as a multicast router, perform
    793 			 * multicast forwarding as if the packet had just
    794 			 * arrived on the interface to which we are about
    795 			 * to send.  The multicast forwarding function
    796 			 * recursively calls this function, using the
    797 			 * IPV6_FORWARDING flag to prevent infinite recursion.
    798 			 *
    799 			 * Multicasts that are looped back by ip6_mloopback(),
    800 			 * above, will be forwarded by the ip6_input() routine,
    801 			 * if necessary.
    802 			 */
    803 			if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
    804 				if (ip6_mforward(ip6, ifp, m) != 0) {
    805 					m_freem(m);
    806 					goto done;
    807 				}
    808 			}
    809 		}
    810 		/*
    811 		 * Multicasts with a hoplimit of zero may be looped back,
    812 		 * above, but must not be transmitted on a network.
    813 		 * Also, multicasts addressed to the loopback interface
    814 		 * are not sent -- the above call to ip6_mloopback() will
    815 		 * loop back a copy if this host actually belongs to the
    816 		 * destination group on the loopback interface.
    817 		 */
    818 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
    819 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
    820 			m_freem(m);
    821 			goto done;
    822 		}
    823 	}
    824 
    825 	/*
    826 	 * Fill the outgoing inteface to tell the upper layer
    827 	 * to increment per-interface statistics.
    828 	 */
    829 	if (ifpp)
    830 		*ifpp = ifp;
    831 
    832 	/* Determine path MTU. */
    833 	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
    834 	    &alwaysfrag)) != 0)
    835 		goto bad;
    836 #ifdef IPSEC
    837 	if (needipsectun)
    838 		mtu = IPV6_MMTU;
    839 #endif
    840 
    841 	/*
    842 	 * The caller of this function may specify to use the minimum MTU
    843 	 * in some cases.
    844 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
    845 	 * setting.  The logic is a bit complicated; by default, unicast
    846 	 * packets will follow path MTU while multicast packets will be sent at
    847 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
    848 	 * including unicast ones will be sent at the minimum MTU.  Multicast
    849 	 * packets will always be sent at the minimum MTU unless
    850 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
    851 	 * See RFC 3542 for more details.
    852 	 */
    853 	if (mtu > IPV6_MMTU) {
    854 		if ((flags & IPV6_MINMTU))
    855 			mtu = IPV6_MMTU;
    856 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
    857 			mtu = IPV6_MMTU;
    858 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
    859 			 (opt == NULL ||
    860 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
    861 			mtu = IPV6_MMTU;
    862 		}
    863 	}
    864 
    865 	/*
    866 	 * clear embedded scope identifiers if necessary.
    867 	 * in6_clearscope will touch the addresses only when necessary.
    868 	 */
    869 	in6_clearscope(&ip6->ip6_src);
    870 	in6_clearscope(&ip6->ip6_dst);
    871 
    872 	/*
    873 	 * If the outgoing packet contains a hop-by-hop options header,
    874 	 * it must be examined and processed even by the source node.
    875 	 * (RFC 2460, section 4.)
    876 	 */
    877 	if (exthdrs.ip6e_hbh) {
    878 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
    879 		u_int32_t dummy1; /* XXX unused */
    880 		u_int32_t dummy2; /* XXX unused */
    881 
    882 		/*
    883 		 *  XXX: if we have to send an ICMPv6 error to the sender,
    884 		 *       we need the M_LOOP flag since icmp6_error() expects
    885 		 *       the IPv6 and the hop-by-hop options header are
    886 		 *       continuous unless the flag is set.
    887 		 */
    888 		m->m_flags |= M_LOOP;
    889 		m->m_pkthdr.rcvif = ifp;
    890 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
    891 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
    892 		    &dummy1, &dummy2) < 0) {
    893 			/* m was already freed at this point */
    894 			error = EINVAL;/* better error? */
    895 			goto done;
    896 		}
    897 		m->m_flags &= ~M_LOOP; /* XXX */
    898 		m->m_pkthdr.rcvif = NULL;
    899 	}
    900 
    901 #ifdef PFIL_HOOKS
    902 	/*
    903 	 * Run through list of hooks for output packets.
    904 	 */
    905 	if ((error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT)) != 0)
    906 		goto done;
    907 	if (m == NULL)
    908 		goto done;
    909 	ip6 = mtod(m, struct ip6_hdr *);
    910 #endif /* PFIL_HOOKS */
    911 	/*
    912 	 * Send the packet to the outgoing interface.
    913 	 * If necessary, do IPv6 fragmentation before sending.
    914 	 *
    915 	 * the logic here is rather complex:
    916 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
    917 	 * 1-a:	send as is if tlen <= path mtu
    918 	 * 1-b:	fragment if tlen > path mtu
    919 	 *
    920 	 * 2: if user asks us not to fragment (dontfrag == 1)
    921 	 * 2-a:	send as is if tlen <= interface mtu
    922 	 * 2-b:	error if tlen > interface mtu
    923 	 *
    924 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
    925 	 *	always fragment
    926 	 *
    927 	 * 4: if dontfrag == 1 && alwaysfrag == 1
    928 	 *	error, as we cannot handle this conflicting request
    929 	 */
    930 	tlen = m->m_pkthdr.len;
    931 	tso = (m->m_pkthdr.csum_flags & M_CSUM_TSOv6) != 0;
    932 	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
    933 		dontfrag = 1;
    934 	else
    935 		dontfrag = 0;
    936 
    937 	if (dontfrag && alwaysfrag) {	/* case 4 */
    938 		/* conflicting request - can't transmit */
    939 		error = EMSGSIZE;
    940 		goto bad;
    941 	}
    942 	if (dontfrag && (!tso && tlen > IN6_LINKMTU(ifp))) {	/* case 2-b */
    943 		/*
    944 		 * Even if the DONTFRAG option is specified, we cannot send the
    945 		 * packet when the data length is larger than the MTU of the
    946 		 * outgoing interface.
    947 		 * Notify the error by sending IPV6_PATHMTU ancillary data as
    948 		 * well as returning an error code (the latter is not described
    949 		 * in the API spec.)
    950 		 */
    951 		u_int32_t mtu32;
    952 		struct ip6ctlparam ip6cp;
    953 
    954 		mtu32 = (u_int32_t)mtu;
    955 		bzero(&ip6cp, sizeof(ip6cp));
    956 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
    957 		pfctlinput2(PRC_MSGSIZE,
    958 		    rtcache_getdst(ro_pmtu), &ip6cp);
    959 
    960 		error = EMSGSIZE;
    961 		goto bad;
    962 	}
    963 
    964 	/*
    965 	 * transmit packet without fragmentation
    966 	 */
    967 	if (dontfrag || (!alwaysfrag && (tlen <= mtu || tso))) {
    968 		/* case 1-a and 2-a */
    969 		struct in6_ifaddr *ia6;
    970 		int sw_csum;
    971 
    972 		ip6 = mtod(m, struct ip6_hdr *);
    973 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
    974 		if (ia6) {
    975 			/* Record statistics for this interface address. */
    976 			ia6->ia_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len;
    977 		}
    978 #ifdef IPSEC
    979 		/* clean ipsec history once it goes out of the node */
    980 		ipsec_delaux(m);
    981 #endif
    982 
    983 		sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx;
    984 		if ((sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    985 			if (IN6_NEED_CHECKSUM(ifp,
    986 			    sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
    987 				in6_delayed_cksum(m);
    988 			}
    989 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    990 		}
    991 
    992 		KASSERT(dst != NULL);
    993 		if (__predict_true(!tso ||
    994 		    (ifp->if_capenable & IFCAP_TSOv6) != 0)) {
    995 			error = nd6_output(ifp, origifp, m, dst, rt);
    996 		} else {
    997 			error = ip6_tso_output(ifp, origifp, m, dst, rt);
    998 		}
    999 		goto done;
   1000 	}
   1001 
   1002 	if (tso) {
   1003 		error = EINVAL; /* XXX */
   1004 		goto bad;
   1005 	}
   1006 
   1007 	/*
   1008 	 * try to fragment the packet.  case 1-b and 3
   1009 	 */
   1010 	if (mtu < IPV6_MMTU) {
   1011 		/* path MTU cannot be less than IPV6_MMTU */
   1012 		error = EMSGSIZE;
   1013 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
   1014 		goto bad;
   1015 	} else if (ip6->ip6_plen == 0) {
   1016 		/* jumbo payload cannot be fragmented */
   1017 		error = EMSGSIZE;
   1018 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
   1019 		goto bad;
   1020 	} else {
   1021 		struct mbuf **mnext, *m_frgpart;
   1022 		struct ip6_frag *ip6f;
   1023 		u_int32_t id = htonl(ip6_randomid());
   1024 		u_char nextproto;
   1025 #if 0				/* see below */
   1026 		struct ip6ctlparam ip6cp;
   1027 		u_int32_t mtu32;
   1028 #endif
   1029 
   1030 		/*
   1031 		 * Too large for the destination or interface;
   1032 		 * fragment if possible.
   1033 		 * Must be able to put at least 8 bytes per fragment.
   1034 		 */
   1035 		hlen = unfragpartlen;
   1036 		if (mtu > IPV6_MAXPACKET)
   1037 			mtu = IPV6_MAXPACKET;
   1038 
   1039 #if 0
   1040 		/*
   1041 		 * It is believed this code is a leftover from the
   1042 		 * development of the IPV6_RECVPATHMTU sockopt and
   1043 		 * associated work to implement RFC3542.
   1044 		 * It's not entirely clear what the intent of the API
   1045 		 * is at this point, so disable this code for now.
   1046 		 * The IPV6_RECVPATHMTU sockopt and/or IPV6_DONTFRAG
   1047 		 * will send notifications if the application requests.
   1048 		 */
   1049 
   1050 		/* Notify a proper path MTU to applications. */
   1051 		mtu32 = (u_int32_t)mtu;
   1052 		bzero(&ip6cp, sizeof(ip6cp));
   1053 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
   1054 		pfctlinput2(PRC_MSGSIZE,
   1055 		    rtcache_getdst(ro_pmtu), &ip6cp);
   1056 #endif
   1057 
   1058 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
   1059 		if (len < 8) {
   1060 			error = EMSGSIZE;
   1061 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
   1062 			goto bad;
   1063 		}
   1064 
   1065 		mnext = &m->m_nextpkt;
   1066 
   1067 		/*
   1068 		 * Change the next header field of the last header in the
   1069 		 * unfragmentable part.
   1070 		 */
   1071 		if (exthdrs.ip6e_rthdr) {
   1072 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
   1073 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
   1074 		} else if (exthdrs.ip6e_dest1) {
   1075 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
   1076 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
   1077 		} else if (exthdrs.ip6e_hbh) {
   1078 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
   1079 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
   1080 		} else {
   1081 			nextproto = ip6->ip6_nxt;
   1082 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
   1083 		}
   1084 
   1085 		if ((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6))
   1086 		    != 0) {
   1087 			if (IN6_NEED_CHECKSUM(ifp,
   1088 			    m->m_pkthdr.csum_flags &
   1089 			    (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
   1090 				in6_delayed_cksum(m);
   1091 			}
   1092 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
   1093 		}
   1094 
   1095 		/*
   1096 		 * Loop through length of segment after first fragment,
   1097 		 * make new header and copy data of each part and link onto
   1098 		 * chain.
   1099 		 */
   1100 		m0 = m;
   1101 		for (off = hlen; off < tlen; off += len) {
   1102 			struct mbuf *mlast;
   1103 
   1104 			MGETHDR(m, M_DONTWAIT, MT_HEADER);
   1105 			if (!m) {
   1106 				error = ENOBUFS;
   1107 				ip6stat.ip6s_odropped++;
   1108 				goto sendorfree;
   1109 			}
   1110 			m->m_pkthdr.rcvif = NULL;
   1111 			m->m_flags = m0->m_flags & M_COPYFLAGS;
   1112 			*mnext = m;
   1113 			mnext = &m->m_nextpkt;
   1114 			m->m_data += max_linkhdr;
   1115 			mhip6 = mtod(m, struct ip6_hdr *);
   1116 			*mhip6 = *ip6;
   1117 			m->m_len = sizeof(*mhip6);
   1118 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
   1119 			if (error) {
   1120 				ip6stat.ip6s_odropped++;
   1121 				goto sendorfree;
   1122 			}
   1123 			ip6f->ip6f_offlg = htons((u_int16_t)((off - hlen) & ~7));
   1124 			if (off + len >= tlen)
   1125 				len = tlen - off;
   1126 			else
   1127 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
   1128 			mhip6->ip6_plen = htons((u_int16_t)(len + hlen +
   1129 			    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
   1130 			if ((m_frgpart = m_copy(m0, off, len)) == 0) {
   1131 				error = ENOBUFS;
   1132 				ip6stat.ip6s_odropped++;
   1133 				goto sendorfree;
   1134 			}
   1135 			for (mlast = m; mlast->m_next; mlast = mlast->m_next)
   1136 				;
   1137 			mlast->m_next = m_frgpart;
   1138 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
   1139 			m->m_pkthdr.rcvif = (struct ifnet *)0;
   1140 			ip6f->ip6f_reserved = 0;
   1141 			ip6f->ip6f_ident = id;
   1142 			ip6f->ip6f_nxt = nextproto;
   1143 			ip6stat.ip6s_ofragments++;
   1144 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
   1145 		}
   1146 
   1147 		in6_ifstat_inc(ifp, ifs6_out_fragok);
   1148 	}
   1149 
   1150 	/*
   1151 	 * Remove leading garbages.
   1152 	 */
   1153 sendorfree:
   1154 	m = m0->m_nextpkt;
   1155 	m0->m_nextpkt = 0;
   1156 	m_freem(m0);
   1157 	for (m0 = m; m; m = m0) {
   1158 		m0 = m->m_nextpkt;
   1159 		m->m_nextpkt = 0;
   1160 		if (error == 0) {
   1161 			struct in6_ifaddr *ia6;
   1162 			ip6 = mtod(m, struct ip6_hdr *);
   1163 			ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
   1164 			if (ia6) {
   1165 				/*
   1166 				 * Record statistics for this interface
   1167 				 * address.
   1168 				 */
   1169 				ia6->ia_ifa.ifa_data.ifad_outbytes +=
   1170 				    m->m_pkthdr.len;
   1171 			}
   1172 #ifdef IPSEC
   1173 			/* clean ipsec history once it goes out of the node */
   1174 			ipsec_delaux(m);
   1175 #endif
   1176 			KASSERT(dst != NULL);
   1177 			error = nd6_output(ifp, origifp, m, dst, rt);
   1178 		} else
   1179 			m_freem(m);
   1180 	}
   1181 
   1182 	if (error == 0)
   1183 		ip6stat.ip6s_fragmented++;
   1184 
   1185 done:
   1186 	/* XXX Second if is invariant? */
   1187 	if (ro == &ip6route)
   1188 		rtcache_free(ro);
   1189 	else if (ro_pmtu == &ip6route)
   1190 		rtcache_free(ro_pmtu);
   1191 
   1192 #ifdef IPSEC
   1193 	if (sp != NULL)
   1194 		key_freesp(sp);
   1195 #endif /* IPSEC */
   1196 #ifdef FAST_IPSEC
   1197 	if (sp != NULL)
   1198 		KEY_FREESP(&sp);
   1199 #endif /* FAST_IPSEC */
   1200 
   1201 
   1202 	return (error);
   1203 
   1204 freehdrs:
   1205 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
   1206 	m_freem(exthdrs.ip6e_dest1);
   1207 	m_freem(exthdrs.ip6e_rthdr);
   1208 	m_freem(exthdrs.ip6e_dest2);
   1209 	/* FALLTHROUGH */
   1210 bad:
   1211 	m_freem(m);
   1212 	goto done;
   1213 badscope:
   1214 	ip6stat.ip6s_badscope++;
   1215 	in6_ifstat_inc(origifp, ifs6_out_discard);
   1216 	if (error == 0)
   1217 		error = EHOSTUNREACH; /* XXX */
   1218 	goto bad;
   1219 }
   1220 
   1221 static int
   1222 ip6_copyexthdr(struct mbuf **mp, void *hdr, int hlen)
   1223 {
   1224 	struct mbuf *m;
   1225 
   1226 	if (hlen > MCLBYTES)
   1227 		return (ENOBUFS); /* XXX */
   1228 
   1229 	MGET(m, M_DONTWAIT, MT_DATA);
   1230 	if (!m)
   1231 		return (ENOBUFS);
   1232 
   1233 	if (hlen > MLEN) {
   1234 		MCLGET(m, M_DONTWAIT);
   1235 		if ((m->m_flags & M_EXT) == 0) {
   1236 			m_free(m);
   1237 			return (ENOBUFS);
   1238 		}
   1239 	}
   1240 	m->m_len = hlen;
   1241 	if (hdr)
   1242 		bcopy(hdr, mtod(m, void *), hlen);
   1243 
   1244 	*mp = m;
   1245 	return (0);
   1246 }
   1247 
   1248 /*
   1249  * Process a delayed payload checksum calculation.
   1250  */
   1251 void
   1252 in6_delayed_cksum(struct mbuf *m)
   1253 {
   1254 	uint16_t csum, offset;
   1255 
   1256 	KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1257 	KASSERT((~m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1258 	KASSERT((m->m_pkthdr.csum_flags
   1259 	    & (M_CSUM_UDPv4|M_CSUM_TCPv4|M_CSUM_TSOv4)) == 0);
   1260 
   1261 	offset = M_CSUM_DATA_IPv6_HL(m->m_pkthdr.csum_data);
   1262 	csum = in6_cksum(m, 0, offset, m->m_pkthdr.len - offset);
   1263 	if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv6) != 0) {
   1264 		csum = 0xffff;
   1265 	}
   1266 
   1267 	offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data);
   1268 	if ((offset + sizeof(csum)) > m->m_len) {
   1269 		m_copyback(m, offset, sizeof(csum), &csum);
   1270 	} else {
   1271 		*(uint16_t *)(mtod(m, char *) + offset) = csum;
   1272 	}
   1273 }
   1274 
   1275 /*
   1276  * Insert jumbo payload option.
   1277  */
   1278 static int
   1279 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
   1280 {
   1281 	struct mbuf *mopt;
   1282 	u_int8_t *optbuf;
   1283 	u_int32_t v;
   1284 
   1285 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
   1286 
   1287 	/*
   1288 	 * If there is no hop-by-hop options header, allocate new one.
   1289 	 * If there is one but it doesn't have enough space to store the
   1290 	 * jumbo payload option, allocate a cluster to store the whole options.
   1291 	 * Otherwise, use it to store the options.
   1292 	 */
   1293 	if (exthdrs->ip6e_hbh == 0) {
   1294 		MGET(mopt, M_DONTWAIT, MT_DATA);
   1295 		if (mopt == 0)
   1296 			return (ENOBUFS);
   1297 		mopt->m_len = JUMBOOPTLEN;
   1298 		optbuf = mtod(mopt, u_int8_t *);
   1299 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
   1300 		exthdrs->ip6e_hbh = mopt;
   1301 	} else {
   1302 		struct ip6_hbh *hbh;
   1303 
   1304 		mopt = exthdrs->ip6e_hbh;
   1305 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
   1306 			/*
   1307 			 * XXX assumption:
   1308 			 * - exthdrs->ip6e_hbh is not referenced from places
   1309 			 *   other than exthdrs.
   1310 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
   1311 			 */
   1312 			int oldoptlen = mopt->m_len;
   1313 			struct mbuf *n;
   1314 
   1315 			/*
   1316 			 * XXX: give up if the whole (new) hbh header does
   1317 			 * not fit even in an mbuf cluster.
   1318 			 */
   1319 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
   1320 				return (ENOBUFS);
   1321 
   1322 			/*
   1323 			 * As a consequence, we must always prepare a cluster
   1324 			 * at this point.
   1325 			 */
   1326 			MGET(n, M_DONTWAIT, MT_DATA);
   1327 			if (n) {
   1328 				MCLGET(n, M_DONTWAIT);
   1329 				if ((n->m_flags & M_EXT) == 0) {
   1330 					m_freem(n);
   1331 					n = NULL;
   1332 				}
   1333 			}
   1334 			if (!n)
   1335 				return (ENOBUFS);
   1336 			n->m_len = oldoptlen + JUMBOOPTLEN;
   1337 			bcopy(mtod(mopt, void *), mtod(n, void *),
   1338 			    oldoptlen);
   1339 			optbuf = mtod(n, u_int8_t *) + oldoptlen;
   1340 			m_freem(mopt);
   1341 			mopt = exthdrs->ip6e_hbh = n;
   1342 		} else {
   1343 			optbuf = mtod(mopt, u_int8_t *) + mopt->m_len;
   1344 			mopt->m_len += JUMBOOPTLEN;
   1345 		}
   1346 		optbuf[0] = IP6OPT_PADN;
   1347 		optbuf[1] = 0;
   1348 
   1349 		/*
   1350 		 * Adjust the header length according to the pad and
   1351 		 * the jumbo payload option.
   1352 		 */
   1353 		hbh = mtod(mopt, struct ip6_hbh *);
   1354 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
   1355 	}
   1356 
   1357 	/* fill in the option. */
   1358 	optbuf[2] = IP6OPT_JUMBO;
   1359 	optbuf[3] = 4;
   1360 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
   1361 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
   1362 
   1363 	/* finally, adjust the packet header length */
   1364 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
   1365 
   1366 	return (0);
   1367 #undef JUMBOOPTLEN
   1368 }
   1369 
   1370 /*
   1371  * Insert fragment header and copy unfragmentable header portions.
   1372  */
   1373 static int
   1374 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
   1375 	struct ip6_frag **frghdrp)
   1376 {
   1377 	struct mbuf *n, *mlast;
   1378 
   1379 	if (hlen > sizeof(struct ip6_hdr)) {
   1380 		n = m_copym(m0, sizeof(struct ip6_hdr),
   1381 		    hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
   1382 		if (n == 0)
   1383 			return (ENOBUFS);
   1384 		m->m_next = n;
   1385 	} else
   1386 		n = m;
   1387 
   1388 	/* Search for the last mbuf of unfragmentable part. */
   1389 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
   1390 		;
   1391 
   1392 	if ((mlast->m_flags & M_EXT) == 0 &&
   1393 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
   1394 		/* use the trailing space of the last mbuf for the fragment hdr */
   1395 		*frghdrp = (struct ip6_frag *)(mtod(mlast, char *) +
   1396 		    mlast->m_len);
   1397 		mlast->m_len += sizeof(struct ip6_frag);
   1398 		m->m_pkthdr.len += sizeof(struct ip6_frag);
   1399 	} else {
   1400 		/* allocate a new mbuf for the fragment header */
   1401 		struct mbuf *mfrg;
   1402 
   1403 		MGET(mfrg, M_DONTWAIT, MT_DATA);
   1404 		if (mfrg == 0)
   1405 			return (ENOBUFS);
   1406 		mfrg->m_len = sizeof(struct ip6_frag);
   1407 		*frghdrp = mtod(mfrg, struct ip6_frag *);
   1408 		mlast->m_next = mfrg;
   1409 	}
   1410 
   1411 	return (0);
   1412 }
   1413 
   1414 static int
   1415 ip6_getpmtu(struct route *ro_pmtu, struct route *ro, struct ifnet *ifp,
   1416     const struct in6_addr *dst, u_long *mtup, int *alwaysfragp)
   1417 {
   1418 	u_int32_t mtu = 0;
   1419 	int alwaysfrag = 0;
   1420 	int error = 0;
   1421 
   1422 	if (ro_pmtu != ro) {
   1423 		union {
   1424 			struct sockaddr		dst;
   1425 			struct sockaddr_in6	dst6;
   1426 		} u;
   1427 
   1428 		/* The first hop and the final destination may differ. */
   1429 		sockaddr_in6_init(&u.dst6, dst, 0, 0, 0);
   1430 		rtcache_lookup(ro_pmtu, &u.dst);
   1431 	}
   1432 	if (ro_pmtu->ro_rt != NULL) {
   1433 		u_int32_t ifmtu;
   1434 
   1435 		if (ifp == NULL)
   1436 			ifp = ro_pmtu->ro_rt->rt_ifp;
   1437 		ifmtu = IN6_LINKMTU(ifp);
   1438 		mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
   1439 		if (mtu == 0)
   1440 			mtu = ifmtu;
   1441 		else if (mtu < IPV6_MMTU) {
   1442 			/*
   1443 			 * RFC2460 section 5, last paragraph:
   1444 			 * if we record ICMPv6 too big message with
   1445 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
   1446 			 * or smaller, with fragment header attached.
   1447 			 * (fragment header is needed regardless from the
   1448 			 * packet size, for translators to identify packets)
   1449 			 */
   1450 			alwaysfrag = 1;
   1451 			mtu = IPV6_MMTU;
   1452 		} else if (mtu > ifmtu) {
   1453 			/*
   1454 			 * The MTU on the route is larger than the MTU on
   1455 			 * the interface!  This shouldn't happen, unless the
   1456 			 * MTU of the interface has been changed after the
   1457 			 * interface was brought up.  Change the MTU in the
   1458 			 * route to match the interface MTU (as long as the
   1459 			 * field isn't locked).
   1460 			 */
   1461 			mtu = ifmtu;
   1462 			if (!(ro_pmtu->ro_rt->rt_rmx.rmx_locks & RTV_MTU))
   1463 				ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
   1464 		}
   1465 	} else if (ifp) {
   1466 		mtu = IN6_LINKMTU(ifp);
   1467 	} else
   1468 		error = EHOSTUNREACH; /* XXX */
   1469 
   1470 	*mtup = mtu;
   1471 	if (alwaysfragp)
   1472 		*alwaysfragp = alwaysfrag;
   1473 	return (error);
   1474 }
   1475 
   1476 /*
   1477  * IP6 socket option processing.
   1478  */
   1479 int
   1480 ip6_ctloutput(int op, struct socket *so, int level, int optname,
   1481     struct mbuf **mp)
   1482 {
   1483 	int privileged, optdatalen, uproto;
   1484 	void *optdata;
   1485 	struct in6pcb *in6p = sotoin6pcb(so);
   1486 	struct mbuf *m = *mp;
   1487 	int error, optval;
   1488 	int optlen;
   1489 	struct lwp *l = curlwp;	/* XXX */
   1490 
   1491 	optlen = m ? m->m_len : 0;
   1492 	error = optval = 0;
   1493 	privileged = (l == 0 || kauth_authorize_generic(l->l_cred,
   1494 	    KAUTH_GENERIC_ISSUSER, NULL)) ? 0 : 1;
   1495 	uproto = (int)so->so_proto->pr_protocol;
   1496 
   1497 	if (level != IPPROTO_IPV6) {
   1498 		if (op == PRCO_SETOPT && *mp)
   1499 			(void)m_free(*mp);
   1500 		return ENOPROTOOPT;
   1501 	}
   1502 	switch (op) {
   1503 	case PRCO_SETOPT:
   1504 		switch (optname) {
   1505 #ifdef RFC2292
   1506 		case IPV6_2292PKTOPTIONS:
   1507 			/* m is freed in ip6_pcbopts */
   1508 			error = ip6_pcbopts(&in6p->in6p_outputopts,
   1509 			    m, so);
   1510 			break;
   1511 #endif
   1512 
   1513 		/*
   1514 		 * Use of some Hop-by-Hop options or some
   1515 		 * Destination options, might require special
   1516 		 * privilege.  That is, normal applications
   1517 		 * (without special privilege) might be forbidden
   1518 		 * from setting certain options in outgoing packets,
   1519 		 * and might never see certain options in received
   1520 		 * packets. [RFC 2292 Section 6]
   1521 		 * KAME specific note:
   1522 		 *  KAME prevents non-privileged users from sending or
   1523 		 *  receiving ANY hbh/dst options in order to avoid
   1524 		 *  overhead of parsing options in the kernel.
   1525 		 */
   1526 		case IPV6_RECVHOPOPTS:
   1527 		case IPV6_RECVDSTOPTS:
   1528 		case IPV6_RECVRTHDRDSTOPTS:
   1529 			if (!privileged) {
   1530 				error = EPERM;
   1531 				break;
   1532 			}
   1533 			/* FALLTHROUGH */
   1534 		case IPV6_UNICAST_HOPS:
   1535 		case IPV6_HOPLIMIT:
   1536 		case IPV6_FAITH:
   1537 
   1538 		case IPV6_RECVPKTINFO:
   1539 		case IPV6_RECVHOPLIMIT:
   1540 		case IPV6_RECVRTHDR:
   1541 		case IPV6_RECVPATHMTU:
   1542 		case IPV6_RECVTCLASS:
   1543 		case IPV6_V6ONLY:
   1544 			if (optlen != sizeof(int)) {
   1545 				error = EINVAL;
   1546 				break;
   1547 			}
   1548 			optval = *mtod(m, int *);
   1549 			switch (optname) {
   1550 
   1551 			case IPV6_UNICAST_HOPS:
   1552 				if (optval < -1 || optval >= 256)
   1553 					error = EINVAL;
   1554 				else {
   1555 					/* -1 = kernel default */
   1556 					in6p->in6p_hops = optval;
   1557 				}
   1558 				break;
   1559 #define OPTSET(bit) \
   1560 do { \
   1561 if (optval) \
   1562 	in6p->in6p_flags |= (bit); \
   1563 else \
   1564 	in6p->in6p_flags &= ~(bit); \
   1565 } while (/*CONSTCOND*/ 0)
   1566 
   1567 #ifdef RFC2292
   1568 #define OPTSET2292(bit) 			\
   1569 do { 						\
   1570 in6p->in6p_flags |= IN6P_RFC2292; 	\
   1571 if (optval) 				\
   1572 	in6p->in6p_flags |= (bit); 	\
   1573 else 					\
   1574 	in6p->in6p_flags &= ~(bit); 	\
   1575 } while (/*CONSTCOND*/ 0)
   1576 #endif
   1577 
   1578 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
   1579 
   1580 			case IPV6_RECVPKTINFO:
   1581 #ifdef RFC2292
   1582 				/* cannot mix with RFC2292 */
   1583 				if (OPTBIT(IN6P_RFC2292)) {
   1584 					error = EINVAL;
   1585 					break;
   1586 				}
   1587 #endif
   1588 				OPTSET(IN6P_PKTINFO);
   1589 				break;
   1590 
   1591 			case IPV6_HOPLIMIT:
   1592 			{
   1593 				struct ip6_pktopts **optp;
   1594 
   1595 #ifdef RFC2292
   1596 				/* cannot mix with RFC2292 */
   1597 				if (OPTBIT(IN6P_RFC2292)) {
   1598 					error = EINVAL;
   1599 					break;
   1600 				}
   1601 #endif
   1602 				optp = &in6p->in6p_outputopts;
   1603 				error = ip6_pcbopt(IPV6_HOPLIMIT,
   1604 						   (u_char *)&optval,
   1605 						   sizeof(optval),
   1606 						   optp,
   1607 						   privileged, uproto);
   1608 				break;
   1609 			}
   1610 
   1611 			case IPV6_RECVHOPLIMIT:
   1612 #ifdef RFC2292
   1613 				/* cannot mix with RFC2292 */
   1614 				if (OPTBIT(IN6P_RFC2292)) {
   1615 					error = EINVAL;
   1616 					break;
   1617 				}
   1618 #endif
   1619 				OPTSET(IN6P_HOPLIMIT);
   1620 				break;
   1621 
   1622 			case IPV6_RECVHOPOPTS:
   1623 #ifdef RFC2292
   1624 				/* cannot mix with RFC2292 */
   1625 				if (OPTBIT(IN6P_RFC2292)) {
   1626 					error = EINVAL;
   1627 					break;
   1628 				}
   1629 #endif
   1630 				OPTSET(IN6P_HOPOPTS);
   1631 				break;
   1632 
   1633 			case IPV6_RECVDSTOPTS:
   1634 #ifdef RFC2292
   1635 				/* cannot mix with RFC2292 */
   1636 				if (OPTBIT(IN6P_RFC2292)) {
   1637 					error = EINVAL;
   1638 					break;
   1639 				}
   1640 #endif
   1641 				OPTSET(IN6P_DSTOPTS);
   1642 				break;
   1643 
   1644 			case IPV6_RECVRTHDRDSTOPTS:
   1645 #ifdef RFC2292
   1646 				/* cannot mix with RFC2292 */
   1647 				if (OPTBIT(IN6P_RFC2292)) {
   1648 					error = EINVAL;
   1649 					break;
   1650 				}
   1651 #endif
   1652 				OPTSET(IN6P_RTHDRDSTOPTS);
   1653 				break;
   1654 
   1655 			case IPV6_RECVRTHDR:
   1656 #ifdef RFC2292
   1657 				/* cannot mix with RFC2292 */
   1658 				if (OPTBIT(IN6P_RFC2292)) {
   1659 					error = EINVAL;
   1660 					break;
   1661 				}
   1662 #endif
   1663 				OPTSET(IN6P_RTHDR);
   1664 				break;
   1665 
   1666 			case IPV6_FAITH:
   1667 				OPTSET(IN6P_FAITH);
   1668 				break;
   1669 
   1670 			case IPV6_RECVPATHMTU:
   1671 				/*
   1672 				 * We ignore this option for TCP
   1673 				 * sockets.
   1674 				 * (RFC3542 leaves this case
   1675 				 * unspecified.)
   1676 				 */
   1677 				if (uproto != IPPROTO_TCP)
   1678 					OPTSET(IN6P_MTU);
   1679 				break;
   1680 
   1681 			case IPV6_V6ONLY:
   1682 				/*
   1683 				 * make setsockopt(IPV6_V6ONLY)
   1684 				 * available only prior to bind(2).
   1685 				 * see ipng mailing list, Jun 22 2001.
   1686 				 */
   1687 				if (in6p->in6p_lport ||
   1688 				    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
   1689 					error = EINVAL;
   1690 					break;
   1691 				}
   1692 #ifdef INET6_BINDV6ONLY
   1693 				if (!optval)
   1694 					error = EINVAL;
   1695 #else
   1696 				OPTSET(IN6P_IPV6_V6ONLY);
   1697 #endif
   1698 				break;
   1699 			case IPV6_RECVTCLASS:
   1700 #ifdef RFC2292
   1701 				/* cannot mix with RFC2292 XXX */
   1702 				if (OPTBIT(IN6P_RFC2292)) {
   1703 					error = EINVAL;
   1704 					break;
   1705 				}
   1706 #endif
   1707 				OPTSET(IN6P_TCLASS);
   1708 				break;
   1709 
   1710 			}
   1711 			break;
   1712 
   1713 		case IPV6_OTCLASS:
   1714 		{
   1715 			struct ip6_pktopts **optp;
   1716 			u_int8_t tclass;
   1717 
   1718 			if (optlen != sizeof(tclass)) {
   1719 				error = EINVAL;
   1720 				break;
   1721 			}
   1722 			tclass = *mtod(m, u_int8_t *);
   1723 			optp = &in6p->in6p_outputopts;
   1724 			error = ip6_pcbopt(optname,
   1725 					   (u_char *)&tclass,
   1726 					   sizeof(tclass),
   1727 					   optp,
   1728 					   privileged, uproto);
   1729 			break;
   1730 		}
   1731 
   1732 		case IPV6_TCLASS:
   1733 		case IPV6_DONTFRAG:
   1734 		case IPV6_USE_MIN_MTU:
   1735 			if (optlen != sizeof(optval)) {
   1736 				error = EINVAL;
   1737 				break;
   1738 			}
   1739 			optval = *mtod(m, int *);
   1740 			{
   1741 				struct ip6_pktopts **optp;
   1742 				optp = &in6p->in6p_outputopts;
   1743 				error = ip6_pcbopt(optname,
   1744 						   (u_char *)&optval,
   1745 						   sizeof(optval),
   1746 						   optp,
   1747 						   privileged, uproto);
   1748 				break;
   1749 			}
   1750 
   1751 #ifdef RFC2292
   1752 		case IPV6_2292PKTINFO:
   1753 		case IPV6_2292HOPLIMIT:
   1754 		case IPV6_2292HOPOPTS:
   1755 		case IPV6_2292DSTOPTS:
   1756 		case IPV6_2292RTHDR:
   1757 			/* RFC 2292 */
   1758 			if (optlen != sizeof(int)) {
   1759 				error = EINVAL;
   1760 				break;
   1761 			}
   1762 			optval = *mtod(m, int *);
   1763 			switch (optname) {
   1764 			case IPV6_2292PKTINFO:
   1765 				OPTSET2292(IN6P_PKTINFO);
   1766 				break;
   1767 			case IPV6_2292HOPLIMIT:
   1768 				OPTSET2292(IN6P_HOPLIMIT);
   1769 				break;
   1770 			case IPV6_2292HOPOPTS:
   1771 				/*
   1772 				 * Check super-user privilege.
   1773 				 * See comments for IPV6_RECVHOPOPTS.
   1774 				 */
   1775 				if (!privileged)
   1776 					return (EPERM);
   1777 				OPTSET2292(IN6P_HOPOPTS);
   1778 				break;
   1779 			case IPV6_2292DSTOPTS:
   1780 				if (!privileged)
   1781 					return (EPERM);
   1782 				OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
   1783 				break;
   1784 			case IPV6_2292RTHDR:
   1785 				OPTSET2292(IN6P_RTHDR);
   1786 				break;
   1787 			}
   1788 			break;
   1789 #endif
   1790 		case IPV6_PKTINFO:
   1791 		case IPV6_HOPOPTS:
   1792 		case IPV6_RTHDR:
   1793 		case IPV6_DSTOPTS:
   1794 		case IPV6_RTHDRDSTOPTS:
   1795 		case IPV6_NEXTHOP:
   1796 		{
   1797 			/* new advanced API (RFC3542) */
   1798 			u_char *optbuf;
   1799 			int optbuflen;
   1800 			struct ip6_pktopts **optp;
   1801 			if (!m) {
   1802 				error = EINVAL;
   1803 				break;
   1804 			}
   1805 
   1806 #ifdef RFC2292
   1807 			/* cannot mix with RFC2292 */
   1808 			if (OPTBIT(IN6P_RFC2292)) {
   1809 				error = EINVAL;
   1810 				break;
   1811 			}
   1812 #endif
   1813 
   1814 			if (m && m->m_next) {
   1815 				error = EINVAL;	/* XXX */
   1816 				break;
   1817 			}
   1818 
   1819 			optbuf = mtod(m, u_char *);
   1820 			optbuflen = m->m_len;
   1821 			optp = &in6p->in6p_outputopts;
   1822 			error = ip6_pcbopt(optname, optbuf, optbuflen,
   1823 			    optp, privileged, uproto);
   1824 			break;
   1825 		}
   1826 #undef OPTSET
   1827 
   1828 		case IPV6_MULTICAST_IF:
   1829 		case IPV6_MULTICAST_HOPS:
   1830 		case IPV6_MULTICAST_LOOP:
   1831 		case IPV6_JOIN_GROUP:
   1832 		case IPV6_LEAVE_GROUP:
   1833 			error = ip6_setmoptions(optname,
   1834 			    &in6p->in6p_moptions, m);
   1835 			break;
   1836 
   1837 		case IPV6_PORTRANGE:
   1838 			if (!m) {
   1839 				error = EINVAL;
   1840 				break;
   1841 			}
   1842 			optval = *mtod(m, int *);
   1843 
   1844 			switch (optval) {
   1845 			case IPV6_PORTRANGE_DEFAULT:
   1846 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1847 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1848 				break;
   1849 
   1850 			case IPV6_PORTRANGE_HIGH:
   1851 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1852 				in6p->in6p_flags |= IN6P_HIGHPORT;
   1853 				break;
   1854 
   1855 			case IPV6_PORTRANGE_LOW:
   1856 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1857 				in6p->in6p_flags |= IN6P_LOWPORT;
   1858 				break;
   1859 
   1860 			default:
   1861 				error = EINVAL;
   1862 				break;
   1863 			}
   1864 			break;
   1865 
   1866 
   1867 #if defined(IPSEC) || defined(FAST_IPSEC)
   1868 		case IPV6_IPSEC_POLICY:
   1869 		{
   1870 			void *req = NULL;
   1871 			size_t len = 0;
   1872 			if (m) {
   1873 				req = mtod(m, void *);
   1874 				len = m->m_len;
   1875 			}
   1876 			error = ipsec6_set_policy(in6p, optname, req,
   1877 						  len, privileged);
   1878 		}
   1879 			break;
   1880 #endif /* IPSEC */
   1881 
   1882 		default:
   1883 			error = ENOPROTOOPT;
   1884 			break;
   1885 		}
   1886 		if (m)
   1887 			(void)m_free(m);
   1888 		break;
   1889 
   1890 	case PRCO_GETOPT:
   1891 		switch (optname) {
   1892 #ifdef RFC2292
   1893 		case IPV6_2292PKTOPTIONS:
   1894 			/*
   1895 			 * RFC3542 (effectively) deprecated the
   1896 			 * semantics of the 2292-style pktoptions.
   1897 			 * Since it was not reliable in nature (i.e.,
   1898 			 * applications had to expect the lack of some
   1899 			 * information after all), it would make sense
   1900 			 * to simplify this part by always returning
   1901 			 * empty data.
   1902 			 */
   1903 			*mp = m_get(M_WAIT, MT_SOOPTS);
   1904 			(*mp)->m_len = 0;
   1905 			break;
   1906 #endif
   1907 
   1908 		case IPV6_RECVHOPOPTS:
   1909 		case IPV6_RECVDSTOPTS:
   1910 		case IPV6_RECVRTHDRDSTOPTS:
   1911 		case IPV6_UNICAST_HOPS:
   1912 		case IPV6_RECVPKTINFO:
   1913 		case IPV6_RECVHOPLIMIT:
   1914 		case IPV6_RECVRTHDR:
   1915 		case IPV6_RECVPATHMTU:
   1916 
   1917 		case IPV6_FAITH:
   1918 		case IPV6_V6ONLY:
   1919 		case IPV6_PORTRANGE:
   1920 		case IPV6_RECVTCLASS:
   1921 			switch (optname) {
   1922 
   1923 			case IPV6_RECVHOPOPTS:
   1924 				optval = OPTBIT(IN6P_HOPOPTS);
   1925 				break;
   1926 
   1927 			case IPV6_RECVDSTOPTS:
   1928 				optval = OPTBIT(IN6P_DSTOPTS);
   1929 				break;
   1930 
   1931 			case IPV6_RECVRTHDRDSTOPTS:
   1932 				optval = OPTBIT(IN6P_RTHDRDSTOPTS);
   1933 				break;
   1934 
   1935 			case IPV6_UNICAST_HOPS:
   1936 				optval = in6p->in6p_hops;
   1937 				break;
   1938 
   1939 			case IPV6_RECVPKTINFO:
   1940 				optval = OPTBIT(IN6P_PKTINFO);
   1941 				break;
   1942 
   1943 			case IPV6_RECVHOPLIMIT:
   1944 				optval = OPTBIT(IN6P_HOPLIMIT);
   1945 				break;
   1946 
   1947 			case IPV6_RECVRTHDR:
   1948 				optval = OPTBIT(IN6P_RTHDR);
   1949 				break;
   1950 
   1951 			case IPV6_RECVPATHMTU:
   1952 				optval = OPTBIT(IN6P_MTU);
   1953 				break;
   1954 
   1955 			case IPV6_FAITH:
   1956 				optval = OPTBIT(IN6P_FAITH);
   1957 				break;
   1958 
   1959 			case IPV6_V6ONLY:
   1960 				optval = OPTBIT(IN6P_IPV6_V6ONLY);
   1961 				break;
   1962 
   1963 			case IPV6_PORTRANGE:
   1964 			    {
   1965 				int flags;
   1966 				flags = in6p->in6p_flags;
   1967 				if (flags & IN6P_HIGHPORT)
   1968 					optval = IPV6_PORTRANGE_HIGH;
   1969 				else if (flags & IN6P_LOWPORT)
   1970 					optval = IPV6_PORTRANGE_LOW;
   1971 				else
   1972 					optval = 0;
   1973 				break;
   1974 			    }
   1975 			case IPV6_RECVTCLASS:
   1976 				optval = OPTBIT(IN6P_TCLASS);
   1977 				break;
   1978 
   1979 			}
   1980 			if (error)
   1981 				break;
   1982 			*mp = m = m_get(M_WAIT, MT_SOOPTS);
   1983 			m->m_len = sizeof(int);
   1984 			*mtod(m, int *) = optval;
   1985 			break;
   1986 
   1987 		case IPV6_PATHMTU:
   1988 		    {
   1989 			u_long pmtu = 0;
   1990 			struct ip6_mtuinfo mtuinfo;
   1991 			struct route *ro = &in6p->in6p_route;
   1992 
   1993 			if (!(so->so_state & SS_ISCONNECTED))
   1994 				return (ENOTCONN);
   1995 			/*
   1996 			 * XXX: we dot not consider the case of source
   1997 			 * routing, or optional information to specify
   1998 			 * the outgoing interface.
   1999 			 */
   2000 			error = ip6_getpmtu(ro, NULL, NULL,
   2001 			    &in6p->in6p_faddr, &pmtu, NULL);
   2002 			if (error)
   2003 				break;
   2004 			if (pmtu > IPV6_MAXPACKET)
   2005 				pmtu = IPV6_MAXPACKET;
   2006 
   2007 			memset(&mtuinfo, 0, sizeof(mtuinfo));
   2008 			mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
   2009 			optdata = (void *)&mtuinfo;
   2010 			optdatalen = sizeof(mtuinfo);
   2011 			if (optdatalen > MCLBYTES)
   2012 				return (EMSGSIZE); /* XXX */
   2013 			*mp = m = m_get(M_WAIT, MT_SOOPTS);
   2014 			if (optdatalen > MLEN)
   2015 				MCLGET(m, M_WAIT);
   2016 			m->m_len = optdatalen;
   2017 			memcpy(mtod(m, void *), optdata, optdatalen);
   2018 			break;
   2019 		    }
   2020 
   2021 #ifdef RFC2292
   2022 		case IPV6_2292PKTINFO:
   2023 		case IPV6_2292HOPLIMIT:
   2024 		case IPV6_2292HOPOPTS:
   2025 		case IPV6_2292RTHDR:
   2026 		case IPV6_2292DSTOPTS:
   2027 			switch (optname) {
   2028 			case IPV6_2292PKTINFO:
   2029 				optval = OPTBIT(IN6P_PKTINFO);
   2030 				break;
   2031 			case IPV6_2292HOPLIMIT:
   2032 				optval = OPTBIT(IN6P_HOPLIMIT);
   2033 				break;
   2034 			case IPV6_2292HOPOPTS:
   2035 				optval = OPTBIT(IN6P_HOPOPTS);
   2036 				break;
   2037 			case IPV6_2292RTHDR:
   2038 				optval = OPTBIT(IN6P_RTHDR);
   2039 				break;
   2040 			case IPV6_2292DSTOPTS:
   2041 				optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
   2042 				break;
   2043 			}
   2044 			*mp = m = m_get(M_WAIT, MT_SOOPTS);
   2045 			m->m_len = sizeof(int);
   2046 			*mtod(m, int *) = optval;
   2047 			break;
   2048 #endif
   2049 		case IPV6_PKTINFO:
   2050 		case IPV6_HOPOPTS:
   2051 		case IPV6_RTHDR:
   2052 		case IPV6_DSTOPTS:
   2053 		case IPV6_RTHDRDSTOPTS:
   2054 		case IPV6_NEXTHOP:
   2055 		case IPV6_OTCLASS:
   2056 		case IPV6_TCLASS:
   2057 		case IPV6_DONTFRAG:
   2058 		case IPV6_USE_MIN_MTU:
   2059 			error = ip6_getpcbopt(in6p->in6p_outputopts,
   2060 			    optname, mp);
   2061 			break;
   2062 
   2063 		case IPV6_MULTICAST_IF:
   2064 		case IPV6_MULTICAST_HOPS:
   2065 		case IPV6_MULTICAST_LOOP:
   2066 		case IPV6_JOIN_GROUP:
   2067 		case IPV6_LEAVE_GROUP:
   2068 			error = ip6_getmoptions(optname,
   2069 			    in6p->in6p_moptions, mp);
   2070 			break;
   2071 
   2072 #if defined(IPSEC) || defined(FAST_IPSEC)
   2073 		case IPV6_IPSEC_POLICY:
   2074 		    {
   2075 			void *req = NULL;
   2076 			size_t len = 0;
   2077 			if (m) {
   2078 				req = mtod(m, void *);
   2079 				len = m->m_len;
   2080 			}
   2081 			error = ipsec6_get_policy(in6p, req, len, mp);
   2082 			break;
   2083 		    }
   2084 #endif /* IPSEC */
   2085 
   2086 
   2087 
   2088 
   2089 		default:
   2090 			error = ENOPROTOOPT;
   2091 			break;
   2092 		}
   2093 		break;
   2094 	}
   2095 	return (error);
   2096 }
   2097 
   2098 int
   2099 ip6_raw_ctloutput(int op, struct socket *so, int level, int optname,
   2100 	struct mbuf **mp)
   2101 {
   2102 	int error = 0, optval, optlen;
   2103 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
   2104 	struct in6pcb *in6p = sotoin6pcb(so);
   2105 	struct mbuf *m = *mp;
   2106 
   2107 	optlen = m ? m->m_len : 0;
   2108 
   2109 	if (level != IPPROTO_IPV6) {
   2110 		if (op == PRCO_SETOPT && *mp)
   2111 			(void)m_free(*mp);
   2112 		return ENOPROTOOPT;
   2113 	}
   2114 
   2115 	switch (optname) {
   2116 	case IPV6_CHECKSUM:
   2117 		/*
   2118 		 * For ICMPv6 sockets, no modification allowed for checksum
   2119 		 * offset, permit "no change" values to help existing apps.
   2120 		 *
   2121 		 * XXX RFC3542 says: "An attempt to set IPV6_CHECKSUM
   2122 		 * for an ICMPv6 socket will fail."  The current
   2123 		 * behavior does not meet RFC3542.
   2124 		 */
   2125 		switch (op) {
   2126 		case PRCO_SETOPT:
   2127 			if (optlen != sizeof(int)) {
   2128 				error = EINVAL;
   2129 				break;
   2130 			}
   2131 			optval = *mtod(m, int *);
   2132 			if ((optval % 2) != 0) {
   2133 				/* the API assumes even offset values */
   2134 				error = EINVAL;
   2135 			} else if (so->so_proto->pr_protocol ==
   2136 			    IPPROTO_ICMPV6) {
   2137 				if (optval != icmp6off)
   2138 					error = EINVAL;
   2139 			} else
   2140 				in6p->in6p_cksum = optval;
   2141 			break;
   2142 
   2143 		case PRCO_GETOPT:
   2144 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
   2145 				optval = icmp6off;
   2146 			else
   2147 				optval = in6p->in6p_cksum;
   2148 
   2149 			*mp = m = m_get(M_WAIT, MT_SOOPTS);
   2150 			m->m_len = sizeof(int);
   2151 			*mtod(m, int *) = optval;
   2152 			break;
   2153 
   2154 		default:
   2155 			error = EINVAL;
   2156 			break;
   2157 		}
   2158 		break;
   2159 
   2160 	default:
   2161 		error = ENOPROTOOPT;
   2162 		break;
   2163 	}
   2164 
   2165 	if (op == PRCO_SETOPT && m)
   2166 		(void)m_free(m);
   2167 
   2168 	return (error);
   2169 }
   2170 
   2171 #ifdef RFC2292
   2172 /*
   2173  * Set up IP6 options in pcb for insertion in output packets or
   2174  * specifying behavior of outgoing packets.
   2175  */
   2176 static int
   2177 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m, struct socket *so)
   2178 {
   2179 	struct ip6_pktopts *opt = *pktopt;
   2180 	int error = 0;
   2181 	struct lwp *l = curlwp;	/* XXX */
   2182 	int priv = 0;
   2183 
   2184 	/* turn off any old options. */
   2185 	if (opt) {
   2186 #ifdef DIAGNOSTIC
   2187 	    if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
   2188 		opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
   2189 		opt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2190 		    printf("ip6_pcbopts: all specified options are cleared.\n");
   2191 #endif
   2192 		ip6_clearpktopts(opt, -1);
   2193 	} else
   2194 		opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
   2195 	*pktopt = NULL;
   2196 
   2197 	if (!m || m->m_len == 0) {
   2198 		/*
   2199 		 * Only turning off any previous options, regardless of
   2200 		 * whether the opt is just created or given.
   2201 		 */
   2202 		free(opt, M_IP6OPT);
   2203 		return (0);
   2204 	}
   2205 
   2206 	/*  set options specified by user. */
   2207 	if (l && !kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER,
   2208 	    NULL))
   2209 		priv = 1;
   2210 	if ((error = ip6_setpktopts(m, opt, NULL, priv,
   2211 	    so->so_proto->pr_protocol)) != 0) {
   2212 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
   2213 		free(opt, M_IP6OPT);
   2214 		return (error);
   2215 	}
   2216 	*pktopt = opt;
   2217 	return (0);
   2218 }
   2219 #endif
   2220 
   2221 /*
   2222  * initialize ip6_pktopts.  beware that there are non-zero default values in
   2223  * the struct.
   2224  */
   2225 void
   2226 ip6_initpktopts(struct ip6_pktopts *opt)
   2227 {
   2228 
   2229 	memset(opt, 0, sizeof(*opt));
   2230 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
   2231 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
   2232 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
   2233 }
   2234 
   2235 #define sin6tosa(sin6)	((struct sockaddr *)(sin6)) /* XXX */
   2236 static int
   2237 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
   2238     int priv, int uproto)
   2239 {
   2240 	struct ip6_pktopts *opt;
   2241 
   2242 	if (*pktopt == NULL) {
   2243 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
   2244 		    M_WAITOK);
   2245 		ip6_initpktopts(*pktopt);
   2246 	}
   2247 	opt = *pktopt;
   2248 
   2249 	return (ip6_setpktopt(optname, buf, len, opt, priv, 1, 0, uproto));
   2250 }
   2251 
   2252 static int
   2253 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct mbuf **mp)
   2254 {
   2255 	void *optdata = NULL;
   2256 	int optdatalen = 0;
   2257 	struct ip6_ext *ip6e;
   2258 	int error = 0;
   2259 	struct in6_pktinfo null_pktinfo;
   2260 	int deftclass = 0, on;
   2261 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
   2262 	struct mbuf *m;
   2263 
   2264 	switch (optname) {
   2265 	case IPV6_PKTINFO:
   2266 		if (pktopt && pktopt->ip6po_pktinfo)
   2267 			optdata = (void *)pktopt->ip6po_pktinfo;
   2268 		else {
   2269 			/* XXX: we don't have to do this every time... */
   2270 			memset(&null_pktinfo, 0, sizeof(null_pktinfo));
   2271 			optdata = (void *)&null_pktinfo;
   2272 		}
   2273 		optdatalen = sizeof(struct in6_pktinfo);
   2274 		break;
   2275 	case IPV6_OTCLASS:
   2276 		/* XXX */
   2277 		return (EINVAL);
   2278 	case IPV6_TCLASS:
   2279 		if (pktopt && pktopt->ip6po_tclass >= 0)
   2280 			optdata = (void *)&pktopt->ip6po_tclass;
   2281 		else
   2282 			optdata = (void *)&deftclass;
   2283 		optdatalen = sizeof(int);
   2284 		break;
   2285 	case IPV6_HOPOPTS:
   2286 		if (pktopt && pktopt->ip6po_hbh) {
   2287 			optdata = (void *)pktopt->ip6po_hbh;
   2288 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
   2289 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2290 		}
   2291 		break;
   2292 	case IPV6_RTHDR:
   2293 		if (pktopt && pktopt->ip6po_rthdr) {
   2294 			optdata = (void *)pktopt->ip6po_rthdr;
   2295 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
   2296 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2297 		}
   2298 		break;
   2299 	case IPV6_RTHDRDSTOPTS:
   2300 		if (pktopt && pktopt->ip6po_dest1) {
   2301 			optdata = (void *)pktopt->ip6po_dest1;
   2302 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
   2303 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2304 		}
   2305 		break;
   2306 	case IPV6_DSTOPTS:
   2307 		if (pktopt && pktopt->ip6po_dest2) {
   2308 			optdata = (void *)pktopt->ip6po_dest2;
   2309 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
   2310 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2311 		}
   2312 		break;
   2313 	case IPV6_NEXTHOP:
   2314 		if (pktopt && pktopt->ip6po_nexthop) {
   2315 			optdata = (void *)pktopt->ip6po_nexthop;
   2316 			optdatalen = pktopt->ip6po_nexthop->sa_len;
   2317 		}
   2318 		break;
   2319 	case IPV6_USE_MIN_MTU:
   2320 		if (pktopt)
   2321 			optdata = (void *)&pktopt->ip6po_minmtu;
   2322 		else
   2323 			optdata = (void *)&defminmtu;
   2324 		optdatalen = sizeof(int);
   2325 		break;
   2326 	case IPV6_DONTFRAG:
   2327 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
   2328 			on = 1;
   2329 		else
   2330 			on = 0;
   2331 		optdata = (void *)&on;
   2332 		optdatalen = sizeof(on);
   2333 		break;
   2334 	default:		/* should not happen */
   2335 #ifdef DIAGNOSTIC
   2336 		panic("ip6_getpcbopt: unexpected option\n");
   2337 #endif
   2338 		return (ENOPROTOOPT);
   2339 	}
   2340 
   2341 	if (optdatalen > MCLBYTES)
   2342 		return (EMSGSIZE); /* XXX */
   2343 	*mp = m = m_get(M_WAIT, MT_SOOPTS);
   2344 	if (optdatalen > MLEN)
   2345 		MCLGET(m, M_WAIT);
   2346 	m->m_len = optdatalen;
   2347 	if (optdatalen)
   2348 		memcpy(mtod(m, void *), optdata, optdatalen);
   2349 
   2350 	return (error);
   2351 }
   2352 
   2353 void
   2354 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
   2355 {
   2356 	if (optname == -1 || optname == IPV6_PKTINFO) {
   2357 		if (pktopt->ip6po_pktinfo)
   2358 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
   2359 		pktopt->ip6po_pktinfo = NULL;
   2360 	}
   2361 	if (optname == -1 || optname == IPV6_HOPLIMIT)
   2362 		pktopt->ip6po_hlim = -1;
   2363 	if (optname == -1 || optname == IPV6_TCLASS)
   2364 		pktopt->ip6po_tclass = -1;
   2365 	if (optname == -1 || optname == IPV6_NEXTHOP) {
   2366 		rtcache_free(&pktopt->ip6po_nextroute);
   2367 		if (pktopt->ip6po_nexthop)
   2368 			free(pktopt->ip6po_nexthop, M_IP6OPT);
   2369 		pktopt->ip6po_nexthop = NULL;
   2370 	}
   2371 	if (optname == -1 || optname == IPV6_HOPOPTS) {
   2372 		if (pktopt->ip6po_hbh)
   2373 			free(pktopt->ip6po_hbh, M_IP6OPT);
   2374 		pktopt->ip6po_hbh = NULL;
   2375 	}
   2376 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
   2377 		if (pktopt->ip6po_dest1)
   2378 			free(pktopt->ip6po_dest1, M_IP6OPT);
   2379 		pktopt->ip6po_dest1 = NULL;
   2380 	}
   2381 	if (optname == -1 || optname == IPV6_RTHDR) {
   2382 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2383 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
   2384 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
   2385 		rtcache_free(&pktopt->ip6po_route);
   2386 	}
   2387 	if (optname == -1 || optname == IPV6_DSTOPTS) {
   2388 		if (pktopt->ip6po_dest2)
   2389 			free(pktopt->ip6po_dest2, M_IP6OPT);
   2390 		pktopt->ip6po_dest2 = NULL;
   2391 	}
   2392 }
   2393 
   2394 #define PKTOPT_EXTHDRCPY(type) 					\
   2395 do {								\
   2396 	if (src->type) {					\
   2397 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
   2398 		dst->type = malloc(hlen, M_IP6OPT, canwait);	\
   2399 		if (dst->type == NULL && canwait == M_NOWAIT)	\
   2400 			goto bad;				\
   2401 		memcpy(dst->type, src->type, hlen);		\
   2402 	}							\
   2403 } while (/*CONSTCOND*/ 0)
   2404 
   2405 static int
   2406 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
   2407 {
   2408 	dst->ip6po_hlim = src->ip6po_hlim;
   2409 	dst->ip6po_tclass = src->ip6po_tclass;
   2410 	dst->ip6po_flags = src->ip6po_flags;
   2411 	if (src->ip6po_pktinfo) {
   2412 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
   2413 		    M_IP6OPT, canwait);
   2414 		if (dst->ip6po_pktinfo == NULL && canwait == M_NOWAIT)
   2415 			goto bad;
   2416 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
   2417 	}
   2418 	if (src->ip6po_nexthop) {
   2419 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
   2420 		    M_IP6OPT, canwait);
   2421 		if (dst->ip6po_nexthop == NULL && canwait == M_NOWAIT)
   2422 			goto bad;
   2423 		memcpy(dst->ip6po_nexthop, src->ip6po_nexthop,
   2424 		    src->ip6po_nexthop->sa_len);
   2425 	}
   2426 	PKTOPT_EXTHDRCPY(ip6po_hbh);
   2427 	PKTOPT_EXTHDRCPY(ip6po_dest1);
   2428 	PKTOPT_EXTHDRCPY(ip6po_dest2);
   2429 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
   2430 	return (0);
   2431 
   2432   bad:
   2433 	if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
   2434 	if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
   2435 	if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
   2436 	if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
   2437 	if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
   2438 	if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
   2439 
   2440 	return (ENOBUFS);
   2441 }
   2442 #undef PKTOPT_EXTHDRCPY
   2443 
   2444 struct ip6_pktopts *
   2445 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
   2446 {
   2447 	int error;
   2448 	struct ip6_pktopts *dst;
   2449 
   2450 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
   2451 	if (dst == NULL && canwait == M_NOWAIT)
   2452 		return (NULL);
   2453 	ip6_initpktopts(dst);
   2454 
   2455 	if ((error = copypktopts(dst, src, canwait)) != 0) {
   2456 		free(dst, M_IP6OPT);
   2457 		return (NULL);
   2458 	}
   2459 
   2460 	return (dst);
   2461 }
   2462 
   2463 void
   2464 ip6_freepcbopts(struct ip6_pktopts *pktopt)
   2465 {
   2466 	if (pktopt == NULL)
   2467 		return;
   2468 
   2469 	ip6_clearpktopts(pktopt, -1);
   2470 
   2471 	free(pktopt, M_IP6OPT);
   2472 }
   2473 
   2474 /*
   2475  * Set the IP6 multicast options in response to user setsockopt().
   2476  */
   2477 static int
   2478 ip6_setmoptions(int optname, struct ip6_moptions **im6op, struct mbuf *m)
   2479 {
   2480 	int error = 0;
   2481 	u_int loop, ifindex;
   2482 	struct ipv6_mreq *mreq;
   2483 	struct ifnet *ifp;
   2484 	struct ip6_moptions *im6o = *im6op;
   2485 	struct route ro;
   2486 	struct in6_multi_mship *imm;
   2487 	struct lwp *l = curlwp;	/* XXX */
   2488 
   2489 	if (im6o == NULL) {
   2490 		/*
   2491 		 * No multicast option buffer attached to the pcb;
   2492 		 * allocate one and initialize to default values.
   2493 		 */
   2494 		im6o = (struct ip6_moptions *)
   2495 			malloc(sizeof(*im6o), M_IPMOPTS, M_WAITOK);
   2496 
   2497 		if (im6o == NULL)
   2498 			return (ENOBUFS);
   2499 		*im6op = im6o;
   2500 		im6o->im6o_multicast_ifp = NULL;
   2501 		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2502 		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
   2503 		LIST_INIT(&im6o->im6o_memberships);
   2504 	}
   2505 
   2506 	switch (optname) {
   2507 
   2508 	case IPV6_MULTICAST_IF:
   2509 		/*
   2510 		 * Select the interface for outgoing multicast packets.
   2511 		 */
   2512 		if (m == NULL || m->m_len != sizeof(u_int)) {
   2513 			error = EINVAL;
   2514 			break;
   2515 		}
   2516 		bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
   2517 		if (ifindex != 0) {
   2518 			if (if_indexlim <= ifindex || !ifindex2ifnet[ifindex]) {
   2519 				error = ENXIO;	/* XXX EINVAL? */
   2520 				break;
   2521 			}
   2522 			ifp = ifindex2ifnet[ifindex];
   2523 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
   2524 				error = EADDRNOTAVAIL;
   2525 				break;
   2526 			}
   2527 		} else
   2528 			ifp = NULL;
   2529 		im6o->im6o_multicast_ifp = ifp;
   2530 		break;
   2531 
   2532 	case IPV6_MULTICAST_HOPS:
   2533 	    {
   2534 		/*
   2535 		 * Set the IP6 hoplimit for outgoing multicast packets.
   2536 		 */
   2537 		int optval;
   2538 		if (m == NULL || m->m_len != sizeof(int)) {
   2539 			error = EINVAL;
   2540 			break;
   2541 		}
   2542 		bcopy(mtod(m, u_int *), &optval, sizeof(optval));
   2543 		if (optval < -1 || optval >= 256)
   2544 			error = EINVAL;
   2545 		else if (optval == -1)
   2546 			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2547 		else
   2548 			im6o->im6o_multicast_hlim = optval;
   2549 		break;
   2550 	    }
   2551 
   2552 	case IPV6_MULTICAST_LOOP:
   2553 		/*
   2554 		 * Set the loopback flag for outgoing multicast packets.
   2555 		 * Must be zero or one.
   2556 		 */
   2557 		if (m == NULL || m->m_len != sizeof(u_int)) {
   2558 			error = EINVAL;
   2559 			break;
   2560 		}
   2561 		bcopy(mtod(m, u_int *), &loop, sizeof(loop));
   2562 		if (loop > 1) {
   2563 			error = EINVAL;
   2564 			break;
   2565 		}
   2566 		im6o->im6o_multicast_loop = loop;
   2567 		break;
   2568 
   2569 	case IPV6_JOIN_GROUP:
   2570 		/*
   2571 		 * Add a multicast group membership.
   2572 		 * Group must be a valid IP6 multicast address.
   2573 		 */
   2574 		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
   2575 			error = EINVAL;
   2576 			break;
   2577 		}
   2578 		mreq = mtod(m, struct ipv6_mreq *);
   2579 		if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
   2580 			/*
   2581 			 * We use the unspecified address to specify to accept
   2582 			 * all multicast addresses. Only super user is allowed
   2583 			 * to do this.
   2584 			 */
   2585 			if (kauth_authorize_generic(l->l_cred,
   2586 			    KAUTH_GENERIC_ISSUSER, NULL))
   2587 			{
   2588 				error = EACCES;
   2589 				break;
   2590 			}
   2591 		} else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
   2592 			error = EINVAL;
   2593 			break;
   2594 		}
   2595 
   2596 		/*
   2597 		 * If no interface was explicitly specified, choose an
   2598 		 * appropriate one according to the given multicast address.
   2599 		 */
   2600 		if (mreq->ipv6mr_interface == 0) {
   2601 			union {
   2602 				struct sockaddr		dst;
   2603 				struct sockaddr_in6	dst6;
   2604 			} u;
   2605 
   2606 			/*
   2607 			 * Look up the routing table for the
   2608 			 * address, and choose the outgoing interface.
   2609 			 *   XXX: is it a good approach?
   2610 			 */
   2611 			memset(&ro, 0, sizeof(ro));
   2612 			sockaddr_in6_init(&u.dst6, &mreq->ipv6mr_multiaddr, 0,
   2613 			    0, 0);
   2614 			rtcache_setdst(&ro, &u.dst);
   2615 			rtcache_init(&ro);
   2616 			ifp = (ro.ro_rt != NULL) ? ro.ro_rt->rt_ifp : NULL;
   2617 			rtcache_free(&ro);
   2618 		} else {
   2619 			/*
   2620 			 * If the interface is specified, validate it.
   2621 			 */
   2622 			if (if_indexlim <= mreq->ipv6mr_interface ||
   2623 			    !ifindex2ifnet[mreq->ipv6mr_interface]) {
   2624 				error = ENXIO;	/* XXX EINVAL? */
   2625 				break;
   2626 			}
   2627 			ifp = ifindex2ifnet[mreq->ipv6mr_interface];
   2628 		}
   2629 
   2630 		/*
   2631 		 * See if we found an interface, and confirm that it
   2632 		 * supports multicast
   2633 		 */
   2634 		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
   2635 			error = EADDRNOTAVAIL;
   2636 			break;
   2637 		}
   2638 
   2639 		if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
   2640 			error = EADDRNOTAVAIL; /* XXX: should not happen */
   2641 			break;
   2642 		}
   2643 
   2644 		/*
   2645 		 * See if the membership already exists.
   2646 		 */
   2647 		for (imm = im6o->im6o_memberships.lh_first;
   2648 		     imm != NULL; imm = imm->i6mm_chain.le_next)
   2649 			if (imm->i6mm_maddr->in6m_ifp == ifp &&
   2650 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2651 			    &mreq->ipv6mr_multiaddr))
   2652 				break;
   2653 		if (imm != NULL) {
   2654 			error = EADDRINUSE;
   2655 			break;
   2656 		}
   2657 		/*
   2658 		 * Everything looks good; add a new record to the multicast
   2659 		 * address list for the given interface.
   2660 		 */
   2661 		imm = in6_joingroup(ifp, &mreq->ipv6mr_multiaddr, &error, 0);
   2662 		if (imm == NULL)
   2663 			break;
   2664 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
   2665 		break;
   2666 
   2667 	case IPV6_LEAVE_GROUP:
   2668 		/*
   2669 		 * Drop a multicast group membership.
   2670 		 * Group must be a valid IP6 multicast address.
   2671 		 */
   2672 		if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
   2673 			error = EINVAL;
   2674 			break;
   2675 		}
   2676 		mreq = mtod(m, struct ipv6_mreq *);
   2677 
   2678 		/*
   2679 		 * If an interface address was specified, get a pointer
   2680 		 * to its ifnet structure.
   2681 		 */
   2682 		if (mreq->ipv6mr_interface != 0) {
   2683 			if (if_indexlim <= mreq->ipv6mr_interface ||
   2684 			    !ifindex2ifnet[mreq->ipv6mr_interface]) {
   2685 				error = ENXIO;	/* XXX EINVAL? */
   2686 				break;
   2687 			}
   2688 			ifp = ifindex2ifnet[mreq->ipv6mr_interface];
   2689 		} else
   2690 			ifp = NULL;
   2691 
   2692 		/* Fill in the scope zone ID */
   2693 		if (ifp) {
   2694 			if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
   2695 				/* XXX: should not happen */
   2696 				error = EADDRNOTAVAIL;
   2697 				break;
   2698 			}
   2699 		} else if (mreq->ipv6mr_interface != 0) {
   2700 			/*
   2701 			 * XXX: This case would happens when the (positive)
   2702 			 * index is in the valid range, but the corresponding
   2703 			 * interface has been detached dynamically.  The above
   2704 			 * check probably avoids such case to happen here, but
   2705 			 * we check it explicitly for safety.
   2706 			 */
   2707 			error = EADDRNOTAVAIL;
   2708 			break;
   2709 		} else {	/* ipv6mr_interface == 0 */
   2710 			struct sockaddr_in6 sa6_mc;
   2711 
   2712 			/*
   2713 			 * The API spec says as follows:
   2714 			 *  If the interface index is specified as 0, the
   2715 			 *  system may choose a multicast group membership to
   2716 			 *  drop by matching the multicast address only.
   2717 			 * On the other hand, we cannot disambiguate the scope
   2718 			 * zone unless an interface is provided.  Thus, we
   2719 			 * check if there's ambiguity with the default scope
   2720 			 * zone as the last resort.
   2721 			 */
   2722 			bzero(&sa6_mc, sizeof(sa6_mc));
   2723 			sa6_mc.sin6_family = AF_INET6;
   2724 			sa6_mc.sin6_len = sizeof(sa6_mc);
   2725 			sa6_mc.sin6_addr = mreq->ipv6mr_multiaddr;
   2726 			error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
   2727 			if (error != 0)
   2728 				break;
   2729 			mreq->ipv6mr_multiaddr = sa6_mc.sin6_addr;
   2730 		}
   2731 
   2732 		/*
   2733 		 * Find the membership in the membership list.
   2734 		 */
   2735 		for (imm = im6o->im6o_memberships.lh_first;
   2736 		     imm != NULL; imm = imm->i6mm_chain.le_next) {
   2737 			if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
   2738 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2739 			    &mreq->ipv6mr_multiaddr))
   2740 				break;
   2741 		}
   2742 		if (imm == NULL) {
   2743 			/* Unable to resolve interface */
   2744 			error = EADDRNOTAVAIL;
   2745 			break;
   2746 		}
   2747 		/*
   2748 		 * Give up the multicast address record to which the
   2749 		 * membership points.
   2750 		 */
   2751 		LIST_REMOVE(imm, i6mm_chain);
   2752 		in6_leavegroup(imm);
   2753 		break;
   2754 
   2755 	default:
   2756 		error = EOPNOTSUPP;
   2757 		break;
   2758 	}
   2759 
   2760 	/*
   2761 	 * If all options have default values, no need to keep the mbuf.
   2762 	 */
   2763 	if (im6o->im6o_multicast_ifp == NULL &&
   2764 	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
   2765 	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
   2766 	    im6o->im6o_memberships.lh_first == NULL) {
   2767 		free(*im6op, M_IPMOPTS);
   2768 		*im6op = NULL;
   2769 	}
   2770 
   2771 	return (error);
   2772 }
   2773 
   2774 /*
   2775  * Return the IP6 multicast options in response to user getsockopt().
   2776  */
   2777 static int
   2778 ip6_getmoptions(int optname, struct ip6_moptions *im6o, struct mbuf **mp)
   2779 {
   2780 	u_int *hlim, *loop, *ifindex;
   2781 
   2782 	*mp = m_get(M_WAIT, MT_SOOPTS);
   2783 
   2784 	switch (optname) {
   2785 
   2786 	case IPV6_MULTICAST_IF:
   2787 		ifindex = mtod(*mp, u_int *);
   2788 		(*mp)->m_len = sizeof(u_int);
   2789 		if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
   2790 			*ifindex = 0;
   2791 		else
   2792 			*ifindex = im6o->im6o_multicast_ifp->if_index;
   2793 		return (0);
   2794 
   2795 	case IPV6_MULTICAST_HOPS:
   2796 		hlim = mtod(*mp, u_int *);
   2797 		(*mp)->m_len = sizeof(u_int);
   2798 		if (im6o == NULL)
   2799 			*hlim = ip6_defmcasthlim;
   2800 		else
   2801 			*hlim = im6o->im6o_multicast_hlim;
   2802 		return (0);
   2803 
   2804 	case IPV6_MULTICAST_LOOP:
   2805 		loop = mtod(*mp, u_int *);
   2806 		(*mp)->m_len = sizeof(u_int);
   2807 		if (im6o == NULL)
   2808 			*loop = ip6_defmcasthlim;
   2809 		else
   2810 			*loop = im6o->im6o_multicast_loop;
   2811 		return (0);
   2812 
   2813 	default:
   2814 		return (EOPNOTSUPP);
   2815 	}
   2816 }
   2817 
   2818 /*
   2819  * Discard the IP6 multicast options.
   2820  */
   2821 void
   2822 ip6_freemoptions(struct ip6_moptions *im6o)
   2823 {
   2824 	struct in6_multi_mship *imm;
   2825 
   2826 	if (im6o == NULL)
   2827 		return;
   2828 
   2829 	while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
   2830 		LIST_REMOVE(imm, i6mm_chain);
   2831 		in6_leavegroup(imm);
   2832 	}
   2833 	free(im6o, M_IPMOPTS);
   2834 }
   2835 
   2836 /*
   2837  * Set IPv6 outgoing packet options based on advanced API.
   2838  */
   2839 int
   2840 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
   2841 	struct ip6_pktopts *stickyopt, int priv, int uproto)
   2842 {
   2843 	struct cmsghdr *cm = 0;
   2844 
   2845 	if (control == NULL || opt == NULL)
   2846 		return (EINVAL);
   2847 
   2848 	ip6_initpktopts(opt);
   2849 	if (stickyopt) {
   2850 		int error;
   2851 
   2852 		/*
   2853 		 * If stickyopt is provided, make a local copy of the options
   2854 		 * for this particular packet, then override them by ancillary
   2855 		 * objects.
   2856 		 * XXX: copypktopts() does not copy the cached route to a next
   2857 		 * hop (if any).  This is not very good in terms of efficiency,
   2858 		 * but we can allow this since this option should be rarely
   2859 		 * used.
   2860 		 */
   2861 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
   2862 			return (error);
   2863 	}
   2864 
   2865 	/*
   2866 	 * XXX: Currently, we assume all the optional information is stored
   2867 	 * in a single mbuf.
   2868 	 */
   2869 	if (control->m_next)
   2870 		return (EINVAL);
   2871 
   2872 	for (; control->m_len; control->m_data += CMSG_ALIGN(cm->cmsg_len),
   2873 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
   2874 		int error;
   2875 
   2876 		if (control->m_len < CMSG_LEN(0))
   2877 			return (EINVAL);
   2878 
   2879 		cm = mtod(control, struct cmsghdr *);
   2880 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
   2881 			return (EINVAL);
   2882 		if (cm->cmsg_level != IPPROTO_IPV6)
   2883 			continue;
   2884 
   2885 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
   2886 		    cm->cmsg_len - CMSG_LEN(0), opt, priv, 0, 1, uproto);
   2887 		if (error)
   2888 			return (error);
   2889 	}
   2890 
   2891 	return (0);
   2892 }
   2893 
   2894 /*
   2895  * Set a particular packet option, as a sticky option or an ancillary data
   2896  * item.  "len" can be 0 only when it's a sticky option.
   2897  * We have 4 cases of combination of "sticky" and "cmsg":
   2898  * "sticky=0, cmsg=0": impossible
   2899  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
   2900  * "sticky=1, cmsg=0": RFC3542 socket option
   2901  * "sticky=1, cmsg=1": RFC2292 socket option
   2902  */
   2903 static int
   2904 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
   2905     int priv, int sticky, int cmsg, int uproto)
   2906 {
   2907 	int minmtupolicy;
   2908 
   2909 	if (!sticky && !cmsg) {
   2910 #ifdef DIAGNOSTIC
   2911 		printf("ip6_setpktopt: impossible case\n");
   2912 #endif
   2913 		return (EINVAL);
   2914 	}
   2915 
   2916 	/*
   2917 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
   2918 	 * not be specified in the context of RFC3542.  Conversely,
   2919 	 * RFC3542 types should not be specified in the context of RFC2292.
   2920 	 */
   2921 	if (!cmsg) {
   2922 		switch (optname) {
   2923 		case IPV6_2292PKTINFO:
   2924 		case IPV6_2292HOPLIMIT:
   2925 		case IPV6_2292NEXTHOP:
   2926 		case IPV6_2292HOPOPTS:
   2927 		case IPV6_2292DSTOPTS:
   2928 		case IPV6_2292RTHDR:
   2929 		case IPV6_2292PKTOPTIONS:
   2930 			return (ENOPROTOOPT);
   2931 		}
   2932 	}
   2933 	if (sticky && cmsg) {
   2934 		switch (optname) {
   2935 		case IPV6_PKTINFO:
   2936 		case IPV6_HOPLIMIT:
   2937 		case IPV6_NEXTHOP:
   2938 		case IPV6_HOPOPTS:
   2939 		case IPV6_DSTOPTS:
   2940 		case IPV6_RTHDRDSTOPTS:
   2941 		case IPV6_RTHDR:
   2942 		case IPV6_USE_MIN_MTU:
   2943 		case IPV6_DONTFRAG:
   2944 		case IPV6_OTCLASS:
   2945 		case IPV6_TCLASS:
   2946 			return (ENOPROTOOPT);
   2947 		}
   2948 	}
   2949 
   2950 	switch (optname) {
   2951 #ifdef RFC2292
   2952 	case IPV6_2292PKTINFO:
   2953 #endif
   2954 	case IPV6_PKTINFO:
   2955 	{
   2956 		struct ifnet *ifp = NULL;
   2957 		struct in6_pktinfo *pktinfo;
   2958 
   2959 		if (len != sizeof(struct in6_pktinfo))
   2960 			return (EINVAL);
   2961 
   2962 		pktinfo = (struct in6_pktinfo *)buf;
   2963 
   2964 		/*
   2965 		 * An application can clear any sticky IPV6_PKTINFO option by
   2966 		 * doing a "regular" setsockopt with ipi6_addr being
   2967 		 * in6addr_any and ipi6_ifindex being zero.
   2968 		 * [RFC 3542, Section 6]
   2969 		 */
   2970 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
   2971 		    pktinfo->ipi6_ifindex == 0 &&
   2972 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2973 			ip6_clearpktopts(opt, optname);
   2974 			break;
   2975 		}
   2976 
   2977 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
   2978 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2979 			return (EINVAL);
   2980 		}
   2981 
   2982 		/* validate the interface index if specified. */
   2983 		if (pktinfo->ipi6_ifindex >= if_indexlim) {
   2984 			 return (ENXIO);
   2985 		}
   2986 		if (pktinfo->ipi6_ifindex) {
   2987 			ifp = ifindex2ifnet[pktinfo->ipi6_ifindex];
   2988 			if (ifp == NULL)
   2989 				return (ENXIO);
   2990 		}
   2991 
   2992 		/*
   2993 		 * We store the address anyway, and let in6_selectsrc()
   2994 		 * validate the specified address.  This is because ipi6_addr
   2995 		 * may not have enough information about its scope zone, and
   2996 		 * we may need additional information (such as outgoing
   2997 		 * interface or the scope zone of a destination address) to
   2998 		 * disambiguate the scope.
   2999 		 * XXX: the delay of the validation may confuse the
   3000 		 * application when it is used as a sticky option.
   3001 		 */
   3002 		if (opt->ip6po_pktinfo == NULL) {
   3003 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
   3004 			    M_IP6OPT, M_NOWAIT);
   3005 			if (opt->ip6po_pktinfo == NULL)
   3006 				return (ENOBUFS);
   3007 		}
   3008 		memcpy(opt->ip6po_pktinfo, pktinfo, sizeof(*pktinfo));
   3009 		break;
   3010 	}
   3011 
   3012 #ifdef RFC2292
   3013 	case IPV6_2292HOPLIMIT:
   3014 #endif
   3015 	case IPV6_HOPLIMIT:
   3016 	{
   3017 		int *hlimp;
   3018 
   3019 		/*
   3020 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
   3021 		 * to simplify the ordering among hoplimit options.
   3022 		 */
   3023 		if (optname == IPV6_HOPLIMIT && sticky)
   3024 			return (ENOPROTOOPT);
   3025 
   3026 		if (len != sizeof(int))
   3027 			return (EINVAL);
   3028 		hlimp = (int *)buf;
   3029 		if (*hlimp < -1 || *hlimp > 255)
   3030 			return (EINVAL);
   3031 
   3032 		opt->ip6po_hlim = *hlimp;
   3033 		break;
   3034 	}
   3035 
   3036 	case IPV6_OTCLASS:
   3037 		if (len != sizeof(u_int8_t))
   3038 			return (EINVAL);
   3039 
   3040 		opt->ip6po_tclass = *(u_int8_t *)buf;
   3041 		break;
   3042 
   3043 	case IPV6_TCLASS:
   3044 	{
   3045 		int tclass;
   3046 
   3047 		if (len != sizeof(int))
   3048 			return (EINVAL);
   3049 		tclass = *(int *)buf;
   3050 		if (tclass < -1 || tclass > 255)
   3051 			return (EINVAL);
   3052 
   3053 		opt->ip6po_tclass = tclass;
   3054 		break;
   3055 	}
   3056 
   3057 #ifdef RFC2292
   3058 	case IPV6_2292NEXTHOP:
   3059 #endif
   3060 	case IPV6_NEXTHOP:
   3061 		if (!priv)
   3062 			return (EPERM);
   3063 
   3064 		if (len == 0) {	/* just remove the option */
   3065 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3066 			break;
   3067 		}
   3068 
   3069 		/* check if cmsg_len is large enough for sa_len */
   3070 		if (len < sizeof(struct sockaddr) || len < *buf)
   3071 			return (EINVAL);
   3072 
   3073 		switch (((struct sockaddr *)buf)->sa_family) {
   3074 		case AF_INET6:
   3075 		{
   3076 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
   3077 			int error;
   3078 
   3079 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
   3080 				return (EINVAL);
   3081 
   3082 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
   3083 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
   3084 				return (EINVAL);
   3085 			}
   3086 			if ((error = sa6_embedscope(sa6, ip6_use_defzone))
   3087 			    != 0) {
   3088 				return (error);
   3089 			}
   3090 			break;
   3091 		}
   3092 		case AF_LINK:	/* eventually be supported? */
   3093 		default:
   3094 			return (EAFNOSUPPORT);
   3095 		}
   3096 
   3097 		/* turn off the previous option, then set the new option. */
   3098 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3099 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
   3100 		if (opt->ip6po_nexthop == NULL)
   3101 			return (ENOBUFS);
   3102 		memcpy(opt->ip6po_nexthop, buf, *buf);
   3103 		break;
   3104 
   3105 #ifdef RFC2292
   3106 	case IPV6_2292HOPOPTS:
   3107 #endif
   3108 	case IPV6_HOPOPTS:
   3109 	{
   3110 		struct ip6_hbh *hbh;
   3111 		int hbhlen;
   3112 
   3113 		/*
   3114 		 * XXX: We don't allow a non-privileged user to set ANY HbH
   3115 		 * options, since per-option restriction has too much
   3116 		 * overhead.
   3117 		 */
   3118 		if (!priv)
   3119 			return (EPERM);
   3120 
   3121 		if (len == 0) {
   3122 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3123 			break;	/* just remove the option */
   3124 		}
   3125 
   3126 		/* message length validation */
   3127 		if (len < sizeof(struct ip6_hbh))
   3128 			return (EINVAL);
   3129 		hbh = (struct ip6_hbh *)buf;
   3130 		hbhlen = (hbh->ip6h_len + 1) << 3;
   3131 		if (len != hbhlen)
   3132 			return (EINVAL);
   3133 
   3134 		/* turn off the previous option, then set the new option. */
   3135 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3136 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
   3137 		if (opt->ip6po_hbh == NULL)
   3138 			return (ENOBUFS);
   3139 		memcpy(opt->ip6po_hbh, hbh, hbhlen);
   3140 
   3141 		break;
   3142 	}
   3143 
   3144 #ifdef RFC2292
   3145 	case IPV6_2292DSTOPTS:
   3146 #endif
   3147 	case IPV6_DSTOPTS:
   3148 	case IPV6_RTHDRDSTOPTS:
   3149 	{
   3150 		struct ip6_dest *dest, **newdest = NULL;
   3151 		int destlen;
   3152 
   3153 		if (!priv)	/* XXX: see the comment for IPV6_HOPOPTS */
   3154 			return (EPERM);
   3155 
   3156 		if (len == 0) {
   3157 			ip6_clearpktopts(opt, optname);
   3158 			break;	/* just remove the option */
   3159 		}
   3160 
   3161 		/* message length validation */
   3162 		if (len < sizeof(struct ip6_dest))
   3163 			return (EINVAL);
   3164 		dest = (struct ip6_dest *)buf;
   3165 		destlen = (dest->ip6d_len + 1) << 3;
   3166 		if (len != destlen)
   3167 			return (EINVAL);
   3168 		/*
   3169 		 * Determine the position that the destination options header
   3170 		 * should be inserted; before or after the routing header.
   3171 		 */
   3172 		switch (optname) {
   3173 		case IPV6_2292DSTOPTS:
   3174 			/*
   3175 			 * The old advanced API is ambiguous on this point.
   3176 			 * Our approach is to determine the position based
   3177 			 * according to the existence of a routing header.
   3178 			 * Note, however, that this depends on the order of the
   3179 			 * extension headers in the ancillary data; the 1st
   3180 			 * part of the destination options header must appear
   3181 			 * before the routing header in the ancillary data,
   3182 			 * too.
   3183 			 * RFC3542 solved the ambiguity by introducing
   3184 			 * separate ancillary data or option types.
   3185 			 */
   3186 			if (opt->ip6po_rthdr == NULL)
   3187 				newdest = &opt->ip6po_dest1;
   3188 			else
   3189 				newdest = &opt->ip6po_dest2;
   3190 			break;
   3191 		case IPV6_RTHDRDSTOPTS:
   3192 			newdest = &opt->ip6po_dest1;
   3193 			break;
   3194 		case IPV6_DSTOPTS:
   3195 			newdest = &opt->ip6po_dest2;
   3196 			break;
   3197 		}
   3198 
   3199 		/* turn off the previous option, then set the new option. */
   3200 		ip6_clearpktopts(opt, optname);
   3201 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
   3202 		if (*newdest == NULL)
   3203 			return (ENOBUFS);
   3204 		memcpy(*newdest, dest, destlen);
   3205 
   3206 		break;
   3207 	}
   3208 
   3209 #ifdef RFC2292
   3210 	case IPV6_2292RTHDR:
   3211 #endif
   3212 	case IPV6_RTHDR:
   3213 	{
   3214 		struct ip6_rthdr *rth;
   3215 		int rthlen;
   3216 
   3217 		if (len == 0) {
   3218 			ip6_clearpktopts(opt, IPV6_RTHDR);
   3219 			break;	/* just remove the option */
   3220 		}
   3221 
   3222 		/* message length validation */
   3223 		if (len < sizeof(struct ip6_rthdr))
   3224 			return (EINVAL);
   3225 		rth = (struct ip6_rthdr *)buf;
   3226 		rthlen = (rth->ip6r_len + 1) << 3;
   3227 		if (len != rthlen)
   3228 			return (EINVAL);
   3229 		switch (rth->ip6r_type) {
   3230 		case IPV6_RTHDR_TYPE_0:
   3231 			if (rth->ip6r_len == 0)	/* must contain one addr */
   3232 				return (EINVAL);
   3233 			if (rth->ip6r_len % 2) /* length must be even */
   3234 				return (EINVAL);
   3235 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
   3236 				return (EINVAL);
   3237 			break;
   3238 		default:
   3239 			return (EINVAL);	/* not supported */
   3240 		}
   3241 		/* turn off the previous option */
   3242 		ip6_clearpktopts(opt, IPV6_RTHDR);
   3243 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
   3244 		if (opt->ip6po_rthdr == NULL)
   3245 			return (ENOBUFS);
   3246 		memcpy(opt->ip6po_rthdr, rth, rthlen);
   3247 		break;
   3248 	}
   3249 
   3250 	case IPV6_USE_MIN_MTU:
   3251 		if (len != sizeof(int))
   3252 			return (EINVAL);
   3253 		minmtupolicy = *(int *)buf;
   3254 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
   3255 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
   3256 		    minmtupolicy != IP6PO_MINMTU_ALL) {
   3257 			return (EINVAL);
   3258 		}
   3259 		opt->ip6po_minmtu = minmtupolicy;
   3260 		break;
   3261 
   3262 	case IPV6_DONTFRAG:
   3263 		if (len != sizeof(int))
   3264 			return (EINVAL);
   3265 
   3266 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
   3267 			/*
   3268 			 * we ignore this option for TCP sockets.
   3269 			 * (RFC3542 leaves this case unspecified.)
   3270 			 */
   3271 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
   3272 		} else
   3273 			opt->ip6po_flags |= IP6PO_DONTFRAG;
   3274 		break;
   3275 
   3276 	default:
   3277 		return (ENOPROTOOPT);
   3278 	} /* end of switch */
   3279 
   3280 	return (0);
   3281 }
   3282 
   3283 /*
   3284  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
   3285  * packet to the input queue of a specified interface.  Note that this
   3286  * calls the output routine of the loopback "driver", but with an interface
   3287  * pointer that might NOT be lo0ifp -- easier than replicating that code here.
   3288  */
   3289 void
   3290 ip6_mloopback(struct ifnet *ifp, struct mbuf *m,
   3291 	const struct sockaddr_in6 *dst)
   3292 {
   3293 	struct mbuf *copym;
   3294 	struct ip6_hdr *ip6;
   3295 
   3296 	copym = m_copy(m, 0, M_COPYALL);
   3297 	if (copym == NULL)
   3298 		return;
   3299 
   3300 	/*
   3301 	 * Make sure to deep-copy IPv6 header portion in case the data
   3302 	 * is in an mbuf cluster, so that we can safely override the IPv6
   3303 	 * header portion later.
   3304 	 */
   3305 	if ((copym->m_flags & M_EXT) != 0 ||
   3306 	    copym->m_len < sizeof(struct ip6_hdr)) {
   3307 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
   3308 		if (copym == NULL)
   3309 			return;
   3310 	}
   3311 
   3312 #ifdef DIAGNOSTIC
   3313 	if (copym->m_len < sizeof(*ip6)) {
   3314 		m_freem(copym);
   3315 		return;
   3316 	}
   3317 #endif
   3318 
   3319 	ip6 = mtod(copym, struct ip6_hdr *);
   3320 	/*
   3321 	 * clear embedded scope identifiers if necessary.
   3322 	 * in6_clearscope will touch the addresses only when necessary.
   3323 	 */
   3324 	in6_clearscope(&ip6->ip6_src);
   3325 	in6_clearscope(&ip6->ip6_dst);
   3326 
   3327 	(void)looutput(ifp, copym, (const struct sockaddr *)dst, NULL);
   3328 }
   3329 
   3330 /*
   3331  * Chop IPv6 header off from the payload.
   3332  */
   3333 static int
   3334 ip6_splithdr(struct mbuf *m,  struct ip6_exthdrs *exthdrs)
   3335 {
   3336 	struct mbuf *mh;
   3337 	struct ip6_hdr *ip6;
   3338 
   3339 	ip6 = mtod(m, struct ip6_hdr *);
   3340 	if (m->m_len > sizeof(*ip6)) {
   3341 		MGETHDR(mh, M_DONTWAIT, MT_HEADER);
   3342 		if (mh == 0) {
   3343 			m_freem(m);
   3344 			return ENOBUFS;
   3345 		}
   3346 		M_MOVE_PKTHDR(mh, m);
   3347 		MH_ALIGN(mh, sizeof(*ip6));
   3348 		m->m_len -= sizeof(*ip6);
   3349 		m->m_data += sizeof(*ip6);
   3350 		mh->m_next = m;
   3351 		m = mh;
   3352 		m->m_len = sizeof(*ip6);
   3353 		bcopy((void *)ip6, mtod(m, void *), sizeof(*ip6));
   3354 	}
   3355 	exthdrs->ip6e_ip6 = m;
   3356 	return 0;
   3357 }
   3358 
   3359 /*
   3360  * Compute IPv6 extension header length.
   3361  */
   3362 int
   3363 ip6_optlen(struct in6pcb *in6p)
   3364 {
   3365 	int len;
   3366 
   3367 	if (!in6p->in6p_outputopts)
   3368 		return 0;
   3369 
   3370 	len = 0;
   3371 #define elen(x) \
   3372     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
   3373 
   3374 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
   3375 	len += elen(in6p->in6p_outputopts->ip6po_dest1);
   3376 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
   3377 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
   3378 	return len;
   3379 #undef elen
   3380 }
   3381