Home | History | Annotate | Line # | Download | only in netinet6
ip6_output.c revision 1.203.2.2
      1 /*	$NetBSD: ip6_output.c,v 1.203.2.2 2018/05/02 07:20:23 pgoyette 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 1.203.2.2 2018/05/02 07:20:23 pgoyette Exp $");
     66 
     67 #ifdef _KERNEL_OPT
     68 #include "opt_inet.h"
     69 #include "opt_inet6.h"
     70 #include "opt_ipsec.h"
     71 #endif
     72 
     73 #include <sys/param.h>
     74 #include <sys/malloc.h>
     75 #include <sys/mbuf.h>
     76 #include <sys/errno.h>
     77 #include <sys/socket.h>
     78 #include <sys/socketvar.h>
     79 #include <sys/syslog.h>
     80 #include <sys/systm.h>
     81 #include <sys/proc.h>
     82 #include <sys/kauth.h>
     83 
     84 #include <net/if.h>
     85 #include <net/route.h>
     86 #include <net/pfil.h>
     87 
     88 #include <netinet/in.h>
     89 #include <netinet/in_var.h>
     90 #include <netinet/ip6.h>
     91 #include <netinet/ip_var.h>
     92 #include <netinet/icmp6.h>
     93 #include <netinet/in_offload.h>
     94 #include <netinet/portalgo.h>
     95 #include <netinet6/in6_offload.h>
     96 #include <netinet6/ip6_var.h>
     97 #include <netinet6/ip6_private.h>
     98 #include <netinet6/in6_pcb.h>
     99 #include <netinet6/nd6.h>
    100 #include <netinet6/ip6protosw.h>
    101 #include <netinet6/scope6_var.h>
    102 
    103 #ifdef IPSEC
    104 #include <netipsec/ipsec.h>
    105 #include <netipsec/ipsec6.h>
    106 #include <netipsec/key.h>
    107 #endif
    108 
    109 extern pfil_head_t *inet6_pfil_hook;	/* XXX */
    110 
    111 struct ip6_exthdrs {
    112 	struct mbuf *ip6e_ip6;
    113 	struct mbuf *ip6e_hbh;
    114 	struct mbuf *ip6e_dest1;
    115 	struct mbuf *ip6e_rthdr;
    116 	struct mbuf *ip6e_dest2;
    117 };
    118 
    119 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
    120 	kauth_cred_t, int);
    121 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
    122 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *, kauth_cred_t,
    123 	int, int, int);
    124 static int ip6_setmoptions(const struct sockopt *, struct in6pcb *);
    125 static int ip6_getmoptions(struct sockopt *, struct in6pcb *);
    126 static int ip6_copyexthdr(struct mbuf **, void *, int);
    127 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
    128 	struct ip6_frag **);
    129 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
    130 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
    131 static int ip6_getpmtu(struct rtentry *, struct ifnet *, u_long *, int *);
    132 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
    133 static int ip6_ifaddrvalid(const struct in6_addr *, const struct in6_addr *);
    134 static int ip6_handle_rthdr(struct ip6_rthdr *, struct ip6_hdr *);
    135 
    136 #ifdef RFC2292
    137 static int ip6_pcbopts(struct ip6_pktopts **, struct socket *, struct sockopt *);
    138 #endif
    139 
    140 static int
    141 ip6_handle_rthdr(struct ip6_rthdr *rh, struct ip6_hdr *ip6)
    142 {
    143 	int error = 0;
    144 
    145 	switch (rh->ip6r_type) {
    146 	case IPV6_RTHDR_TYPE_0:
    147 		/* Dropped, RFC5095. */
    148 	default:	/* is it possible? */
    149 		error = EINVAL;
    150 	}
    151 
    152 	return error;
    153 }
    154 
    155 /*
    156  * Send an IP packet to a host.
    157  */
    158 int
    159 ip6_if_output(struct ifnet * const ifp, struct ifnet * const origifp,
    160     struct mbuf * const m, const struct sockaddr_in6 * const dst,
    161     const struct rtentry *rt)
    162 {
    163 	int error = 0;
    164 
    165 	if (rt != NULL) {
    166 		error = rt_check_reject_route(rt, ifp);
    167 		if (error != 0) {
    168 			m_freem(m);
    169 			return error;
    170 		}
    171 	}
    172 
    173 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
    174 		error = if_output_lock(ifp, origifp, m, sin6tocsa(dst), rt);
    175 	else
    176 		error = if_output_lock(ifp, ifp, m, sin6tocsa(dst), rt);
    177 	return error;
    178 }
    179 
    180 /*
    181  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
    182  * header (with pri, len, nxt, hlim, src, dst).
    183  *
    184  * This function may modify ver and hlim only. The mbuf chain containing the
    185  * packet will be freed. The mbuf opt, if present, will not be freed.
    186  *
    187  * Type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
    188  * nd_ifinfo.linkmtu is u_int32_t. So we use u_long to hold largest one,
    189  * which is rt_rmx.rmx_mtu.
    190  */
    191 int
    192 ip6_output(
    193     struct mbuf *m0,
    194     struct ip6_pktopts *opt,
    195     struct route *ro,
    196     int flags,
    197     struct ip6_moptions *im6o,
    198     struct in6pcb *in6p,
    199     struct ifnet **ifpp		/* XXX: just for statistics */
    200 )
    201 {
    202 	struct ip6_hdr *ip6, *mhip6;
    203 	struct ifnet *ifp = NULL, *origifp = NULL;
    204 	struct mbuf *m = m0;
    205 	int tlen, len, off;
    206 	bool tso;
    207 	struct route ip6route;
    208 	struct rtentry *rt = NULL, *rt_pmtu;
    209 	const struct sockaddr_in6 *dst;
    210 	struct sockaddr_in6 src_sa, dst_sa;
    211 	int error = 0;
    212 	struct in6_ifaddr *ia = NULL;
    213 	u_long mtu;
    214 	int alwaysfrag, dontfrag;
    215 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
    216 	struct ip6_exthdrs exthdrs;
    217 	struct in6_addr finaldst, src0, dst0;
    218 	u_int32_t zone;
    219 	struct route *ro_pmtu = NULL;
    220 	int hdrsplit = 0;
    221 	int needipsec = 0;
    222 #ifdef IPSEC
    223 	struct secpolicy *sp = NULL;
    224 #endif
    225 	struct psref psref, psref_ia;
    226 	int bound = curlwp_bind();
    227 	bool release_psref_ia = false;
    228 
    229 #ifdef DIAGNOSTIC
    230 	if ((m->m_flags & M_PKTHDR) == 0)
    231 		panic("ip6_output: no HDR");
    232 	if ((m->m_pkthdr.csum_flags &
    233 	    (M_CSUM_TCPv4|M_CSUM_UDPv4|M_CSUM_TSOv4)) != 0) {
    234 		panic("ip6_output: IPv4 checksum offload flags: %d",
    235 		    m->m_pkthdr.csum_flags);
    236 	}
    237 	if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) ==
    238 	    (M_CSUM_TCPv6|M_CSUM_UDPv6)) {
    239 		panic("ip6_output: conflicting checksum offload flags: %d",
    240 		    m->m_pkthdr.csum_flags);
    241 	}
    242 #endif
    243 
    244 	M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data, sizeof(struct ip6_hdr));
    245 
    246 #define MAKE_EXTHDR(hp, mp)						\
    247     do {								\
    248 	if (hp) {							\
    249 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
    250 		error = ip6_copyexthdr((mp), (void *)(hp), 		\
    251 		    ((eh)->ip6e_len + 1) << 3);				\
    252 		if (error)						\
    253 			goto freehdrs;					\
    254 	}								\
    255     } while (/*CONSTCOND*/ 0)
    256 
    257 	memset(&exthdrs, 0, sizeof(exthdrs));
    258 	if (opt) {
    259 		/* Hop-by-Hop options header */
    260 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
    261 		/* Destination options header (1st part) */
    262 		MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
    263 		/* Routing header */
    264 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
    265 		/* Destination options header (2nd part) */
    266 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
    267 	}
    268 
    269 	/*
    270 	 * Calculate the total length of the extension header chain.
    271 	 * Keep the length of the unfragmentable part for fragmentation.
    272 	 */
    273 	optlen = 0;
    274 	if (exthdrs.ip6e_hbh)
    275 		optlen += exthdrs.ip6e_hbh->m_len;
    276 	if (exthdrs.ip6e_dest1)
    277 		optlen += exthdrs.ip6e_dest1->m_len;
    278 	if (exthdrs.ip6e_rthdr)
    279 		optlen += exthdrs.ip6e_rthdr->m_len;
    280 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
    281 	/* NOTE: we don't add AH/ESP length here. do that later. */
    282 	if (exthdrs.ip6e_dest2)
    283 		optlen += exthdrs.ip6e_dest2->m_len;
    284 
    285 #ifdef IPSEC
    286 	if (ipsec_used) {
    287 		/* Check the security policy (SP) for the packet */
    288 		sp = ipsec6_check_policy(m, in6p, flags, &needipsec, &error);
    289 		if (error != 0) {
    290 			/*
    291 			 * Hack: -EINVAL is used to signal that a packet
    292 			 * should be silently discarded.  This is typically
    293 			 * because we asked key management for an SA and
    294 			 * it was delayed (e.g. kicked up to IKE).
    295 			 */
    296 			if (error == -EINVAL)
    297 				error = 0;
    298 			goto freehdrs;
    299 		}
    300 	}
    301 #endif
    302 
    303 	if (needipsec &&
    304 	    (m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    305 		in6_delayed_cksum(m);
    306 		m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    307 	}
    308 
    309 	/*
    310 	 * If we need IPsec, or there is at least one extension header,
    311 	 * separate IP6 header from the payload.
    312 	 */
    313 	if ((needipsec || optlen) && !hdrsplit) {
    314 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    315 			m = NULL;
    316 			goto freehdrs;
    317 		}
    318 		m = exthdrs.ip6e_ip6;
    319 		hdrsplit++;
    320 	}
    321 
    322 	/* adjust pointer */
    323 	ip6 = mtod(m, struct ip6_hdr *);
    324 
    325 	/* adjust mbuf packet header length */
    326 	m->m_pkthdr.len += optlen;
    327 	plen = m->m_pkthdr.len - sizeof(*ip6);
    328 
    329 	/* If this is a jumbo payload, insert a jumbo payload option. */
    330 	if (plen > IPV6_MAXPACKET) {
    331 		if (!hdrsplit) {
    332 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    333 				m = NULL;
    334 				goto freehdrs;
    335 			}
    336 			m = exthdrs.ip6e_ip6;
    337 			hdrsplit++;
    338 		}
    339 		/* adjust pointer */
    340 		ip6 = mtod(m, struct ip6_hdr *);
    341 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
    342 			goto freehdrs;
    343 		optlen += 8; /* XXX JUMBOOPTLEN */
    344 		ip6->ip6_plen = 0;
    345 	} else
    346 		ip6->ip6_plen = htons(plen);
    347 
    348 	/*
    349 	 * Concatenate headers and fill in next header fields.
    350 	 * Here we have, on "m"
    351 	 *	IPv6 payload
    352 	 * and we insert headers accordingly.  Finally, we should be getting:
    353 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
    354 	 *
    355 	 * during the header composing process, "m" points to IPv6 header.
    356 	 * "mprev" points to an extension header prior to esp.
    357 	 */
    358 	{
    359 		u_char *nexthdrp = &ip6->ip6_nxt;
    360 		struct mbuf *mprev = m;
    361 
    362 		/*
    363 		 * we treat dest2 specially.  this makes IPsec processing
    364 		 * much easier.  the goal here is to make mprev point the
    365 		 * mbuf prior to dest2.
    366 		 *
    367 		 * result: IPv6 dest2 payload
    368 		 * m and mprev will point to IPv6 header.
    369 		 */
    370 		if (exthdrs.ip6e_dest2) {
    371 			if (!hdrsplit)
    372 				panic("assumption failed: hdr not split");
    373 			exthdrs.ip6e_dest2->m_next = m->m_next;
    374 			m->m_next = exthdrs.ip6e_dest2;
    375 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
    376 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
    377 		}
    378 
    379 #define MAKE_CHAIN(m, mp, p, i)\
    380     do {\
    381 	if (m) {\
    382 		if (!hdrsplit) \
    383 			panic("assumption failed: hdr not split"); \
    384 		*mtod((m), u_char *) = *(p);\
    385 		*(p) = (i);\
    386 		p = mtod((m), u_char *);\
    387 		(m)->m_next = (mp)->m_next;\
    388 		(mp)->m_next = (m);\
    389 		(mp) = (m);\
    390 	}\
    391     } while (/*CONSTCOND*/ 0)
    392 		/*
    393 		 * result: IPv6 hbh dest1 rthdr dest2 payload
    394 		 * m will point to IPv6 header.  mprev will point to the
    395 		 * extension header prior to dest2 (rthdr in the above case).
    396 		 */
    397 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
    398 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
    399 		    IPPROTO_DSTOPTS);
    400 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
    401 		    IPPROTO_ROUTING);
    402 
    403 		M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data,
    404 		    sizeof(struct ip6_hdr) + optlen);
    405 	}
    406 
    407 	/* Need to save for pmtu */
    408 	finaldst = ip6->ip6_dst;
    409 
    410 	/*
    411 	 * If there is a routing header, replace destination address field
    412 	 * with the first hop of the routing header.
    413 	 */
    414 	if (exthdrs.ip6e_rthdr) {
    415 		struct ip6_rthdr *rh;
    416 
    417 		rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
    418 
    419 		error = ip6_handle_rthdr(rh, ip6);
    420 		if (error != 0)
    421 			goto bad;
    422 	}
    423 
    424 	/* Source address validation */
    425 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
    426 	    (flags & IPV6_UNSPECSRC) == 0) {
    427 		error = EOPNOTSUPP;
    428 		IP6_STATINC(IP6_STAT_BADSCOPE);
    429 		goto bad;
    430 	}
    431 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
    432 		error = EOPNOTSUPP;
    433 		IP6_STATINC(IP6_STAT_BADSCOPE);
    434 		goto bad;
    435 	}
    436 
    437 	IP6_STATINC(IP6_STAT_LOCALOUT);
    438 
    439 	/*
    440 	 * Route packet.
    441 	 */
    442 	/* initialize cached route */
    443 	if (ro == NULL) {
    444 		memset(&ip6route, 0, sizeof(ip6route));
    445 		ro = &ip6route;
    446 	}
    447 	ro_pmtu = ro;
    448 	if (opt && opt->ip6po_rthdr)
    449 		ro = &opt->ip6po_route;
    450 
    451 	/*
    452 	 * if specified, try to fill in the traffic class field.
    453 	 * do not override if a non-zero value is already set.
    454 	 * we check the diffserv field and the ecn field separately.
    455 	 */
    456 	if (opt && opt->ip6po_tclass >= 0) {
    457 		int mask = 0;
    458 
    459 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
    460 			mask |= 0xfc;
    461 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
    462 			mask |= 0x03;
    463 		if (mask != 0)
    464 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
    465 	}
    466 
    467 	/* fill in or override the hop limit field, if necessary. */
    468 	if (opt && opt->ip6po_hlim != -1)
    469 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
    470 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    471 		if (im6o != NULL)
    472 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
    473 		else
    474 			ip6->ip6_hlim = ip6_defmcasthlim;
    475 	}
    476 
    477 #ifdef IPSEC
    478 	if (needipsec) {
    479 		int s = splsoftnet();
    480 		error = ipsec6_process_packet(m, sp->req);
    481 		splx(s);
    482 
    483 		/*
    484 		 * Preserve KAME behaviour: ENOENT can be returned
    485 		 * when an SA acquire is in progress.  Don't propagate
    486 		 * this to user-level; it confuses applications.
    487 		 * XXX this will go away when the SADB is redone.
    488 		 */
    489 		if (error == ENOENT)
    490 			error = 0;
    491 
    492 		goto done;
    493 	}
    494 #endif
    495 
    496 	/* adjust pointer */
    497 	ip6 = mtod(m, struct ip6_hdr *);
    498 
    499 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    500 
    501 	/* We do not need a route for multicast */
    502 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    503 		struct in6_pktinfo *pi = NULL;
    504 
    505 		/*
    506 		 * If the outgoing interface for the address is specified by
    507 		 * the caller, use it.
    508 		 */
    509 		if (opt && (pi = opt->ip6po_pktinfo) != NULL) {
    510 			/* XXX boundary check is assumed to be already done. */
    511 			ifp = if_get_byindex(pi->ipi6_ifindex, &psref);
    512 		} else if (im6o != NULL) {
    513 			ifp = if_get_byindex(im6o->im6o_multicast_if_index,
    514 			    &psref);
    515 		}
    516 	}
    517 
    518 	if (ifp == NULL) {
    519 		error = in6_selectroute(&dst_sa, opt, &ro, &rt, true);
    520 		if (error != 0)
    521 			goto bad;
    522 		ifp = if_get_byindex(rt->rt_ifp->if_index, &psref);
    523 	}
    524 
    525 	if (rt == NULL) {
    526 		/*
    527 		 * If in6_selectroute() does not return a route entry,
    528 		 * dst may not have been updated.
    529 		 */
    530 		error = rtcache_setdst(ro, sin6tosa(&dst_sa));
    531 		if (error) {
    532 			goto bad;
    533 		}
    534 	}
    535 
    536 	/*
    537 	 * then rt (for unicast) and ifp must be non-NULL valid values.
    538 	 */
    539 	if ((flags & IPV6_FORWARDING) == 0) {
    540 		/* XXX: the FORWARDING flag can be set for mrouting. */
    541 		in6_ifstat_inc(ifp, ifs6_out_request);
    542 	}
    543 	if (rt != NULL) {
    544 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
    545 		rt->rt_use++;
    546 	}
    547 
    548 	/*
    549 	 * The outgoing interface must be in the zone of source and
    550 	 * destination addresses.  We should use ia_ifp to support the
    551 	 * case of sending packets to an address of our own.
    552 	 */
    553 	if (ia != NULL && ia->ia_ifp) {
    554 		origifp = ia->ia_ifp;
    555 		if (if_is_deactivated(origifp))
    556 			goto bad;
    557 		if_acquire(origifp, &psref_ia);
    558 		release_psref_ia = true;
    559 	} else
    560 		origifp = ifp;
    561 
    562 	src0 = ip6->ip6_src;
    563 	if (in6_setscope(&src0, origifp, &zone))
    564 		goto badscope;
    565 	sockaddr_in6_init(&src_sa, &ip6->ip6_src, 0, 0, 0);
    566 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
    567 		goto badscope;
    568 
    569 	dst0 = ip6->ip6_dst;
    570 	if (in6_setscope(&dst0, origifp, &zone))
    571 		goto badscope;
    572 	/* re-initialize to be sure */
    573 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    574 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id)
    575 		goto badscope;
    576 
    577 	/* scope check is done. */
    578 
    579 	/* Ensure we only send from a valid address. */
    580 	if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
    581 	    (error = ip6_ifaddrvalid(&src0, &dst0)) != 0)
    582 	{
    583 		char ip6buf[INET6_ADDRSTRLEN];
    584 		nd6log(LOG_ERR,
    585 		    "refusing to send from invalid address %s (pid %d)\n",
    586 		    IN6_PRINT(ip6buf, &src0), curproc->p_pid);
    587 		IP6_STATINC(IP6_STAT_ODROPPED);
    588 		in6_ifstat_inc(origifp, ifs6_out_discard);
    589 		if (error == 1)
    590 			/*
    591 			 * Address exists, but is tentative or detached.
    592 			 * We can't send from it because it's invalid,
    593 			 * so we drop the packet.
    594 			 */
    595 			error = 0;
    596 		else
    597 			error = EADDRNOTAVAIL;
    598 		goto bad;
    599 	}
    600 
    601 	if (rt != NULL && (rt->rt_flags & RTF_GATEWAY) &&
    602 	    !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
    603 		dst = satocsin6(rt->rt_gateway);
    604 	else
    605 		dst = satocsin6(rtcache_getdst(ro));
    606 
    607 	/*
    608 	 * XXXXXX: original code follows:
    609 	 */
    610 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
    611 		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
    612 	else {
    613 		bool ingroup;
    614 
    615 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
    616 
    617 		in6_ifstat_inc(ifp, ifs6_out_mcast);
    618 
    619 		/*
    620 		 * Confirm that the outgoing interface supports multicast.
    621 		 */
    622 		if (!(ifp->if_flags & IFF_MULTICAST)) {
    623 			IP6_STATINC(IP6_STAT_NOROUTE);
    624 			in6_ifstat_inc(ifp, ifs6_out_discard);
    625 			error = ENETUNREACH;
    626 			goto bad;
    627 		}
    628 
    629 		ingroup = in6_multi_group(&ip6->ip6_dst, ifp);
    630 		if (ingroup && (im6o == NULL || im6o->im6o_multicast_loop)) {
    631 			/*
    632 			 * If we belong to the destination multicast group
    633 			 * on the outgoing interface, and the caller did not
    634 			 * forbid loopback, loop back a copy.
    635 			 */
    636 			KASSERT(dst != NULL);
    637 			ip6_mloopback(ifp, m, dst);
    638 		} else {
    639 			/*
    640 			 * If we are acting as a multicast router, perform
    641 			 * multicast forwarding as if the packet had just
    642 			 * arrived on the interface to which we are about
    643 			 * to send.  The multicast forwarding function
    644 			 * recursively calls this function, using the
    645 			 * IPV6_FORWARDING flag to prevent infinite recursion.
    646 			 *
    647 			 * Multicasts that are looped back by ip6_mloopback(),
    648 			 * above, will be forwarded by the ip6_input() routine,
    649 			 * if necessary.
    650 			 */
    651 			if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
    652 				if (ip6_mforward(ip6, ifp, m) != 0) {
    653 					m_freem(m);
    654 					goto done;
    655 				}
    656 			}
    657 		}
    658 		/*
    659 		 * Multicasts with a hoplimit of zero may be looped back,
    660 		 * above, but must not be transmitted on a network.
    661 		 * Also, multicasts addressed to the loopback interface
    662 		 * are not sent -- the above call to ip6_mloopback() will
    663 		 * loop back a copy if this host actually belongs to the
    664 		 * destination group on the loopback interface.
    665 		 */
    666 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
    667 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
    668 			m_freem(m);
    669 			goto done;
    670 		}
    671 	}
    672 
    673 	/*
    674 	 * Fill the outgoing inteface to tell the upper layer
    675 	 * to increment per-interface statistics.
    676 	 */
    677 	if (ifpp)
    678 		*ifpp = ifp;
    679 
    680 	/* Determine path MTU. */
    681 	/*
    682 	 * ro_pmtu represent final destination while
    683 	 * ro might represent immediate destination.
    684 	 * Use ro_pmtu destination since MTU might differ.
    685 	 */
    686 	if (ro_pmtu != ro) {
    687 		union {
    688 			struct sockaddr		dst;
    689 			struct sockaddr_in6	dst6;
    690 		} u;
    691 
    692 		/* ro_pmtu may not have a cache */
    693 		sockaddr_in6_init(&u.dst6, &finaldst, 0, 0, 0);
    694 		rt_pmtu = rtcache_lookup(ro_pmtu, &u.dst);
    695 	} else
    696 		rt_pmtu = rt;
    697 	error = ip6_getpmtu(rt_pmtu, ifp, &mtu, &alwaysfrag);
    698 	if (rt_pmtu != NULL && rt_pmtu != rt)
    699 		rtcache_unref(rt_pmtu, ro_pmtu);
    700 	if (error != 0)
    701 		goto bad;
    702 
    703 	/*
    704 	 * The caller of this function may specify to use the minimum MTU
    705 	 * in some cases.
    706 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
    707 	 * setting.  The logic is a bit complicated; by default, unicast
    708 	 * packets will follow path MTU while multicast packets will be sent at
    709 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
    710 	 * including unicast ones will be sent at the minimum MTU.  Multicast
    711 	 * packets will always be sent at the minimum MTU unless
    712 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
    713 	 * See RFC 3542 for more details.
    714 	 */
    715 	if (mtu > IPV6_MMTU) {
    716 		if ((flags & IPV6_MINMTU))
    717 			mtu = IPV6_MMTU;
    718 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
    719 			mtu = IPV6_MMTU;
    720 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
    721 			 (opt == NULL ||
    722 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
    723 			mtu = IPV6_MMTU;
    724 		}
    725 	}
    726 
    727 	/*
    728 	 * clear embedded scope identifiers if necessary.
    729 	 * in6_clearscope will touch the addresses only when necessary.
    730 	 */
    731 	in6_clearscope(&ip6->ip6_src);
    732 	in6_clearscope(&ip6->ip6_dst);
    733 
    734 	/*
    735 	 * If the outgoing packet contains a hop-by-hop options header,
    736 	 * it must be examined and processed even by the source node.
    737 	 * (RFC 2460, section 4.)
    738 	 *
    739 	 * XXX Is this really necessary?
    740 	 */
    741 	if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
    742 		u_int32_t dummy1; /* XXX unused */
    743 		u_int32_t dummy2; /* XXX unused */
    744 		int hoff = sizeof(struct ip6_hdr);
    745 
    746 		if (ip6_hopopts_input(&dummy1, &dummy2, &m, &hoff)) {
    747 			/* m was already freed at this point */
    748 			error = EINVAL;
    749 			goto done;
    750 		}
    751 
    752 		ip6 = mtod(m, struct ip6_hdr *);
    753 	}
    754 
    755 	/*
    756 	 * Run through list of hooks for output packets.
    757 	 */
    758 	if ((error = pfil_run_hooks(inet6_pfil_hook, &m, ifp, PFIL_OUT)) != 0)
    759 		goto done;
    760 	if (m == NULL)
    761 		goto done;
    762 	ip6 = mtod(m, struct ip6_hdr *);
    763 
    764 	/*
    765 	 * Send the packet to the outgoing interface.
    766 	 * If necessary, do IPv6 fragmentation before sending.
    767 	 *
    768 	 * the logic here is rather complex:
    769 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
    770 	 * 1-a:	send as is if tlen <= path mtu
    771 	 * 1-b:	fragment if tlen > path mtu
    772 	 *
    773 	 * 2: if user asks us not to fragment (dontfrag == 1)
    774 	 * 2-a:	send as is if tlen <= interface mtu
    775 	 * 2-b:	error if tlen > interface mtu
    776 	 *
    777 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
    778 	 *	always fragment
    779 	 *
    780 	 * 4: if dontfrag == 1 && alwaysfrag == 1
    781 	 *	error, as we cannot handle this conflicting request
    782 	 */
    783 	tlen = m->m_pkthdr.len;
    784 	tso = (m->m_pkthdr.csum_flags & M_CSUM_TSOv6) != 0;
    785 	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
    786 		dontfrag = 1;
    787 	else
    788 		dontfrag = 0;
    789 
    790 	if (dontfrag && alwaysfrag) {	/* case 4 */
    791 		/* conflicting request - can't transmit */
    792 		error = EMSGSIZE;
    793 		goto bad;
    794 	}
    795 	if (dontfrag && (!tso && tlen > IN6_LINKMTU(ifp))) {	/* case 2-b */
    796 		/*
    797 		 * Even if the DONTFRAG option is specified, we cannot send the
    798 		 * packet when the data length is larger than the MTU of the
    799 		 * outgoing interface.
    800 		 * Notify the error by sending IPV6_PATHMTU ancillary data as
    801 		 * well as returning an error code (the latter is not described
    802 		 * in the API spec.)
    803 		 */
    804 		u_int32_t mtu32;
    805 		struct ip6ctlparam ip6cp;
    806 
    807 		mtu32 = (u_int32_t)mtu;
    808 		memset(&ip6cp, 0, sizeof(ip6cp));
    809 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
    810 		pfctlinput2(PRC_MSGSIZE,
    811 		    rtcache_getdst(ro_pmtu), &ip6cp);
    812 
    813 		error = EMSGSIZE;
    814 		goto bad;
    815 	}
    816 
    817 	/*
    818 	 * transmit packet without fragmentation
    819 	 */
    820 	if (dontfrag || (!alwaysfrag && (tlen <= mtu || tso))) {
    821 		/* case 1-a and 2-a */
    822 		struct in6_ifaddr *ia6;
    823 		int sw_csum;
    824 		int s;
    825 
    826 		ip6 = mtod(m, struct ip6_hdr *);
    827 		s = pserialize_read_enter();
    828 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
    829 		if (ia6) {
    830 			/* Record statistics for this interface address. */
    831 			ia6->ia_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len;
    832 		}
    833 		pserialize_read_exit(s);
    834 
    835 		sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx;
    836 		if ((sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    837 			if (IN6_NEED_CHECKSUM(ifp,
    838 			    sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
    839 				in6_delayed_cksum(m);
    840 			}
    841 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    842 		}
    843 
    844 		KASSERT(dst != NULL);
    845 		if (__predict_true(!tso ||
    846 		    (ifp->if_capenable & IFCAP_TSOv6) != 0)) {
    847 			error = ip6_if_output(ifp, origifp, m, dst, rt);
    848 		} else {
    849 			error = ip6_tso_output(ifp, origifp, m, dst, rt);
    850 		}
    851 		goto done;
    852 	}
    853 
    854 	if (tso) {
    855 		error = EINVAL; /* XXX */
    856 		goto bad;
    857 	}
    858 
    859 	/*
    860 	 * try to fragment the packet.  case 1-b and 3
    861 	 */
    862 	if (mtu < IPV6_MMTU) {
    863 		/* path MTU cannot be less than IPV6_MMTU */
    864 		error = EMSGSIZE;
    865 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
    866 		goto bad;
    867 	} else if (ip6->ip6_plen == 0) {
    868 		/* jumbo payload cannot be fragmented */
    869 		error = EMSGSIZE;
    870 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
    871 		goto bad;
    872 	} else {
    873 		const u_int32_t id = htonl(ip6_randomid());
    874 		struct mbuf **mnext, *m_frgpart;
    875 		const int hlen = unfragpartlen;
    876 		struct ip6_frag *ip6f;
    877 		u_char nextproto;
    878 #if 0		/* see below */
    879 		struct ip6ctlparam ip6cp;
    880 		u_int32_t mtu32;
    881 #endif
    882 
    883 		if (mtu > IPV6_MAXPACKET)
    884 			mtu = IPV6_MAXPACKET;
    885 
    886 #if 0
    887 		/*
    888 		 * It is believed this code is a leftover from the
    889 		 * development of the IPV6_RECVPATHMTU sockopt and
    890 		 * associated work to implement RFC3542.
    891 		 * It's not entirely clear what the intent of the API
    892 		 * is at this point, so disable this code for now.
    893 		 * The IPV6_RECVPATHMTU sockopt and/or IPV6_DONTFRAG
    894 		 * will send notifications if the application requests.
    895 		 */
    896 
    897 		/* Notify a proper path MTU to applications. */
    898 		mtu32 = (u_int32_t)mtu;
    899 		memset(&ip6cp, 0, sizeof(ip6cp));
    900 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
    901 		pfctlinput2(PRC_MSGSIZE,
    902 		    rtcache_getdst(ro_pmtu), &ip6cp);
    903 #endif
    904 
    905 		/*
    906 		 * Must be able to put at least 8 bytes per fragment.
    907 		 */
    908 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
    909 		if (len < 8) {
    910 			error = EMSGSIZE;
    911 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
    912 			goto bad;
    913 		}
    914 
    915 		mnext = &m->m_nextpkt;
    916 
    917 		/*
    918 		 * Change the next header field of the last header in the
    919 		 * unfragmentable part.
    920 		 */
    921 		if (exthdrs.ip6e_rthdr) {
    922 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
    923 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
    924 		} else if (exthdrs.ip6e_dest1) {
    925 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
    926 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
    927 		} else if (exthdrs.ip6e_hbh) {
    928 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
    929 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
    930 		} else {
    931 			nextproto = ip6->ip6_nxt;
    932 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
    933 		}
    934 
    935 		if ((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6))
    936 		    != 0) {
    937 			if (IN6_NEED_CHECKSUM(ifp,
    938 			    m->m_pkthdr.csum_flags &
    939 			    (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
    940 				in6_delayed_cksum(m);
    941 			}
    942 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    943 		}
    944 
    945 		/*
    946 		 * Loop through length of segment after first fragment,
    947 		 * make new header and copy data of each part and link onto
    948 		 * chain.
    949 		 */
    950 		m0 = m;
    951 		for (off = hlen; off < tlen; off += len) {
    952 			struct mbuf *mlast;
    953 
    954 			MGETHDR(m, M_DONTWAIT, MT_HEADER);
    955 			if (!m) {
    956 				error = ENOBUFS;
    957 				IP6_STATINC(IP6_STAT_ODROPPED);
    958 				goto sendorfree;
    959 			}
    960 			m_reset_rcvif(m);
    961 			m->m_flags = m0->m_flags & M_COPYFLAGS;
    962 			*mnext = m;
    963 			mnext = &m->m_nextpkt;
    964 			m->m_data += max_linkhdr;
    965 			mhip6 = mtod(m, struct ip6_hdr *);
    966 			*mhip6 = *ip6;
    967 			m->m_len = sizeof(*mhip6);
    968 
    969 			ip6f = NULL;
    970 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
    971 			if (error) {
    972 				IP6_STATINC(IP6_STAT_ODROPPED);
    973 				goto sendorfree;
    974 			}
    975 
    976 			/* Fill in the Frag6 Header */
    977 			ip6f->ip6f_offlg = htons((u_int16_t)((off - hlen) & ~7));
    978 			if (off + len >= tlen)
    979 				len = tlen - off;
    980 			else
    981 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
    982 			ip6f->ip6f_reserved = 0;
    983 			ip6f->ip6f_ident = id;
    984 			ip6f->ip6f_nxt = nextproto;
    985 
    986 			mhip6->ip6_plen = htons((u_int16_t)(len + hlen +
    987 			    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
    988 			if ((m_frgpart = m_copym(m0, off, len, M_DONTWAIT)) == NULL) {
    989 				error = ENOBUFS;
    990 				IP6_STATINC(IP6_STAT_ODROPPED);
    991 				goto sendorfree;
    992 			}
    993 			for (mlast = m; mlast->m_next; mlast = mlast->m_next)
    994 				;
    995 			mlast->m_next = m_frgpart;
    996 
    997 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
    998 			m_reset_rcvif(m);
    999 			IP6_STATINC(IP6_STAT_OFRAGMENTS);
   1000 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
   1001 		}
   1002 
   1003 		in6_ifstat_inc(ifp, ifs6_out_fragok);
   1004 	}
   1005 
   1006 sendorfree:
   1007 	m = m0->m_nextpkt;
   1008 	m0->m_nextpkt = 0;
   1009 	m_freem(m0);
   1010 	for (m0 = m; m; m = m0) {
   1011 		m0 = m->m_nextpkt;
   1012 		m->m_nextpkt = 0;
   1013 		if (error == 0) {
   1014 			struct in6_ifaddr *ia6;
   1015 			int s;
   1016 			ip6 = mtod(m, struct ip6_hdr *);
   1017 			s = pserialize_read_enter();
   1018 			ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
   1019 			if (ia6) {
   1020 				/*
   1021 				 * Record statistics for this interface
   1022 				 * address.
   1023 				 */
   1024 				ia6->ia_ifa.ifa_data.ifad_outbytes +=
   1025 				    m->m_pkthdr.len;
   1026 			}
   1027 			pserialize_read_exit(s);
   1028 			KASSERT(dst != NULL);
   1029 			error = ip6_if_output(ifp, origifp, m, dst, rt);
   1030 		} else
   1031 			m_freem(m);
   1032 	}
   1033 
   1034 	if (error == 0)
   1035 		IP6_STATINC(IP6_STAT_FRAGMENTED);
   1036 
   1037 done:
   1038 	rtcache_unref(rt, ro);
   1039 	if (ro == &ip6route)
   1040 		rtcache_free(&ip6route);
   1041 #ifdef IPSEC
   1042 	if (sp != NULL)
   1043 		KEY_SP_UNREF(&sp);
   1044 #endif
   1045 	if_put(ifp, &psref);
   1046 	if (release_psref_ia)
   1047 		if_put(origifp, &psref_ia);
   1048 	curlwp_bindx(bound);
   1049 
   1050 	return error;
   1051 
   1052 freehdrs:
   1053 	m_freem(exthdrs.ip6e_hbh);
   1054 	m_freem(exthdrs.ip6e_dest1);
   1055 	m_freem(exthdrs.ip6e_rthdr);
   1056 	m_freem(exthdrs.ip6e_dest2);
   1057 	/* FALLTHROUGH */
   1058 bad:
   1059 	m_freem(m);
   1060 	goto done;
   1061 
   1062 badscope:
   1063 	IP6_STATINC(IP6_STAT_BADSCOPE);
   1064 	in6_ifstat_inc(origifp, ifs6_out_discard);
   1065 	if (error == 0)
   1066 		error = EHOSTUNREACH; /* XXX */
   1067 	goto bad;
   1068 }
   1069 
   1070 static int
   1071 ip6_copyexthdr(struct mbuf **mp, void *hdr, int hlen)
   1072 {
   1073 	struct mbuf *m;
   1074 
   1075 	if (hlen > MCLBYTES)
   1076 		return ENOBUFS; /* XXX */
   1077 
   1078 	MGET(m, M_DONTWAIT, MT_DATA);
   1079 	if (!m)
   1080 		return ENOBUFS;
   1081 
   1082 	if (hlen > MLEN) {
   1083 		MCLGET(m, M_DONTWAIT);
   1084 		if ((m->m_flags & M_EXT) == 0) {
   1085 			m_free(m);
   1086 			return ENOBUFS;
   1087 		}
   1088 	}
   1089 	m->m_len = hlen;
   1090 	if (hdr)
   1091 		memcpy(mtod(m, void *), hdr, hlen);
   1092 
   1093 	*mp = m;
   1094 	return 0;
   1095 }
   1096 
   1097 /*
   1098  * Process a delayed payload checksum calculation.
   1099  */
   1100 void
   1101 in6_delayed_cksum(struct mbuf *m)
   1102 {
   1103 	uint16_t csum, offset;
   1104 
   1105 	KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1106 	KASSERT((~m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1107 	KASSERT((m->m_pkthdr.csum_flags
   1108 	    & (M_CSUM_UDPv4|M_CSUM_TCPv4|M_CSUM_TSOv4)) == 0);
   1109 
   1110 	offset = M_CSUM_DATA_IPv6_HL(m->m_pkthdr.csum_data);
   1111 	csum = in6_cksum(m, 0, offset, m->m_pkthdr.len - offset);
   1112 	if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv6) != 0) {
   1113 		csum = 0xffff;
   1114 	}
   1115 
   1116 	offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data);
   1117 	if ((offset + sizeof(csum)) > m->m_len) {
   1118 		m_copyback(m, offset, sizeof(csum), &csum);
   1119 	} else {
   1120 		*(uint16_t *)(mtod(m, char *) + offset) = csum;
   1121 	}
   1122 }
   1123 
   1124 /*
   1125  * Insert jumbo payload option.
   1126  */
   1127 static int
   1128 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
   1129 {
   1130 	struct mbuf *mopt;
   1131 	u_int8_t *optbuf;
   1132 	u_int32_t v;
   1133 
   1134 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
   1135 
   1136 	/*
   1137 	 * If there is no hop-by-hop options header, allocate new one.
   1138 	 * If there is one but it doesn't have enough space to store the
   1139 	 * jumbo payload option, allocate a cluster to store the whole options.
   1140 	 * Otherwise, use it to store the options.
   1141 	 */
   1142 	if (exthdrs->ip6e_hbh == NULL) {
   1143 		MGET(mopt, M_DONTWAIT, MT_DATA);
   1144 		if (mopt == 0)
   1145 			return (ENOBUFS);
   1146 		mopt->m_len = JUMBOOPTLEN;
   1147 		optbuf = mtod(mopt, u_int8_t *);
   1148 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
   1149 		exthdrs->ip6e_hbh = mopt;
   1150 	} else {
   1151 		struct ip6_hbh *hbh;
   1152 
   1153 		mopt = exthdrs->ip6e_hbh;
   1154 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
   1155 			const int oldoptlen = mopt->m_len;
   1156 			struct mbuf *n;
   1157 
   1158 			/*
   1159 			 * Assumptions:
   1160 			 * - exthdrs->ip6e_hbh is not referenced from places
   1161 			 *   other than exthdrs.
   1162 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
   1163 			 */
   1164 			KASSERT(mopt->m_next == NULL);
   1165 
   1166 			/*
   1167 			 * Give up if the whole (new) hbh header does not fit
   1168 			 * even in an mbuf cluster.
   1169 			 */
   1170 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
   1171 				return ENOBUFS;
   1172 
   1173 			/*
   1174 			 * At this point, we must always prepare a cluster.
   1175 			 */
   1176 			MGET(n, M_DONTWAIT, MT_DATA);
   1177 			if (n) {
   1178 				MCLGET(n, M_DONTWAIT);
   1179 				if ((n->m_flags & M_EXT) == 0) {
   1180 					m_freem(n);
   1181 					n = NULL;
   1182 				}
   1183 			}
   1184 			if (!n)
   1185 				return ENOBUFS;
   1186 
   1187 			n->m_len = oldoptlen + JUMBOOPTLEN;
   1188 			bcopy(mtod(mopt, void *), mtod(n, void *),
   1189 			    oldoptlen);
   1190 			optbuf = mtod(n, u_int8_t *) + oldoptlen;
   1191 			m_freem(mopt);
   1192 			mopt = exthdrs->ip6e_hbh = n;
   1193 		} else {
   1194 			optbuf = mtod(mopt, u_int8_t *) + mopt->m_len;
   1195 			mopt->m_len += JUMBOOPTLEN;
   1196 		}
   1197 		optbuf[0] = IP6OPT_PADN;
   1198 		optbuf[1] = 0;
   1199 
   1200 		/*
   1201 		 * Adjust the header length according to the pad and
   1202 		 * the jumbo payload option.
   1203 		 */
   1204 		hbh = mtod(mopt, struct ip6_hbh *);
   1205 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
   1206 	}
   1207 
   1208 	/* fill in the option. */
   1209 	optbuf[2] = IP6OPT_JUMBO;
   1210 	optbuf[3] = 4;
   1211 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
   1212 	memcpy(&optbuf[4], &v, sizeof(u_int32_t));
   1213 
   1214 	/* finally, adjust the packet header length */
   1215 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
   1216 
   1217 	return 0;
   1218 #undef JUMBOOPTLEN
   1219 }
   1220 
   1221 /*
   1222  * Insert fragment header and copy unfragmentable header portions.
   1223  *
   1224  * *frghdrp will not be read, and it is guaranteed that either an
   1225  * error is returned or that *frghdrp will point to space allocated
   1226  * for the fragment header.
   1227  *
   1228  * On entry, m contains:
   1229  *     IPv6 Header
   1230  * On exit, it contains:
   1231  *     IPv6 Header -> Unfragmentable Part -> Frag6 Header
   1232  */
   1233 static int
   1234 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
   1235 	struct ip6_frag **frghdrp)
   1236 {
   1237 	struct mbuf *n, *mlast;
   1238 
   1239 	if (hlen > sizeof(struct ip6_hdr)) {
   1240 		n = m_copym(m0, sizeof(struct ip6_hdr),
   1241 		    hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
   1242 		if (n == NULL)
   1243 			return ENOBUFS;
   1244 		m->m_next = n;
   1245 	} else
   1246 		n = m;
   1247 
   1248 	/* Search for the last mbuf of unfragmentable part. */
   1249 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
   1250 		;
   1251 
   1252 	if ((mlast->m_flags & M_EXT) == 0 &&
   1253 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
   1254 		/* use the trailing space of the last mbuf for the fragment hdr */
   1255 		*frghdrp = (struct ip6_frag *)(mtod(mlast, char *) +
   1256 		    mlast->m_len);
   1257 		mlast->m_len += sizeof(struct ip6_frag);
   1258 	} else {
   1259 		/* allocate a new mbuf for the fragment header */
   1260 		struct mbuf *mfrg;
   1261 
   1262 		MGET(mfrg, M_DONTWAIT, MT_DATA);
   1263 		if (mfrg == NULL)
   1264 			return ENOBUFS;
   1265 		mfrg->m_len = sizeof(struct ip6_frag);
   1266 		*frghdrp = mtod(mfrg, struct ip6_frag *);
   1267 		mlast->m_next = mfrg;
   1268 	}
   1269 
   1270 	return 0;
   1271 }
   1272 
   1273 static int
   1274 ip6_getpmtu(struct rtentry *rt, struct ifnet *ifp, u_long *mtup,
   1275     int *alwaysfragp)
   1276 {
   1277 	u_int32_t mtu = 0;
   1278 	int alwaysfrag = 0;
   1279 	int error = 0;
   1280 
   1281 	if (rt != NULL) {
   1282 		u_int32_t ifmtu;
   1283 
   1284 		if (ifp == NULL)
   1285 			ifp = rt->rt_ifp;
   1286 		ifmtu = IN6_LINKMTU(ifp);
   1287 		mtu = rt->rt_rmx.rmx_mtu;
   1288 		if (mtu == 0)
   1289 			mtu = ifmtu;
   1290 		else if (mtu < IPV6_MMTU) {
   1291 			/*
   1292 			 * RFC2460 section 5, last paragraph:
   1293 			 * if we record ICMPv6 too big message with
   1294 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
   1295 			 * or smaller, with fragment header attached.
   1296 			 * (fragment header is needed regardless from the
   1297 			 * packet size, for translators to identify packets)
   1298 			 */
   1299 			alwaysfrag = 1;
   1300 			mtu = IPV6_MMTU;
   1301 		} else if (mtu > ifmtu) {
   1302 			/*
   1303 			 * The MTU on the route is larger than the MTU on
   1304 			 * the interface!  This shouldn't happen, unless the
   1305 			 * MTU of the interface has been changed after the
   1306 			 * interface was brought up.  Change the MTU in the
   1307 			 * route to match the interface MTU (as long as the
   1308 			 * field isn't locked).
   1309 			 */
   1310 			mtu = ifmtu;
   1311 			if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
   1312 				rt->rt_rmx.rmx_mtu = mtu;
   1313 		}
   1314 	} else if (ifp) {
   1315 		mtu = IN6_LINKMTU(ifp);
   1316 	} else
   1317 		error = EHOSTUNREACH; /* XXX */
   1318 
   1319 	*mtup = mtu;
   1320 	if (alwaysfragp)
   1321 		*alwaysfragp = alwaysfrag;
   1322 	return (error);
   1323 }
   1324 
   1325 /*
   1326  * IP6 socket option processing.
   1327  */
   1328 int
   1329 ip6_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   1330 {
   1331 	int optdatalen, uproto;
   1332 	void *optdata;
   1333 	struct in6pcb *in6p = sotoin6pcb(so);
   1334 	struct ip_moptions **mopts;
   1335 	int error, optval;
   1336 	int level, optname;
   1337 
   1338 	KASSERT(solocked(so));
   1339 	KASSERT(sopt != NULL);
   1340 
   1341 	level = sopt->sopt_level;
   1342 	optname = sopt->sopt_name;
   1343 
   1344 	error = optval = 0;
   1345 	uproto = (int)so->so_proto->pr_protocol;
   1346 
   1347 	switch (level) {
   1348 	case IPPROTO_IP:
   1349 		switch (optname) {
   1350 		case IP_ADD_MEMBERSHIP:
   1351 		case IP_DROP_MEMBERSHIP:
   1352 		case IP_MULTICAST_IF:
   1353 		case IP_MULTICAST_LOOP:
   1354 		case IP_MULTICAST_TTL:
   1355 			mopts = &in6p->in6p_v4moptions;
   1356 			switch (op) {
   1357 			case PRCO_GETOPT:
   1358 				return ip_getmoptions(*mopts, sopt);
   1359 			case PRCO_SETOPT:
   1360 				return ip_setmoptions(mopts, sopt);
   1361 			default:
   1362 				return EINVAL;
   1363 			}
   1364 		default:
   1365 			return ENOPROTOOPT;
   1366 		}
   1367 	case IPPROTO_IPV6:
   1368 		break;
   1369 	default:
   1370 		return ENOPROTOOPT;
   1371 	}
   1372 	switch (op) {
   1373 	case PRCO_SETOPT:
   1374 		switch (optname) {
   1375 #ifdef RFC2292
   1376 		case IPV6_2292PKTOPTIONS:
   1377 			error = ip6_pcbopts(&in6p->in6p_outputopts, so, sopt);
   1378 			break;
   1379 #endif
   1380 
   1381 		/*
   1382 		 * Use of some Hop-by-Hop options or some
   1383 		 * Destination options, might require special
   1384 		 * privilege.  That is, normal applications
   1385 		 * (without special privilege) might be forbidden
   1386 		 * from setting certain options in outgoing packets,
   1387 		 * and might never see certain options in received
   1388 		 * packets. [RFC 2292 Section 6]
   1389 		 * KAME specific note:
   1390 		 *  KAME prevents non-privileged users from sending or
   1391 		 *  receiving ANY hbh/dst options in order to avoid
   1392 		 *  overhead of parsing options in the kernel.
   1393 		 */
   1394 		case IPV6_RECVHOPOPTS:
   1395 		case IPV6_RECVDSTOPTS:
   1396 		case IPV6_RECVRTHDRDSTOPTS:
   1397 			error = kauth_authorize_network(kauth_cred_get(),
   1398 			    KAUTH_NETWORK_IPV6, KAUTH_REQ_NETWORK_IPV6_HOPBYHOP,
   1399 			    NULL, NULL, NULL);
   1400 			if (error)
   1401 				break;
   1402 			/* FALLTHROUGH */
   1403 		case IPV6_UNICAST_HOPS:
   1404 		case IPV6_HOPLIMIT:
   1405 		case IPV6_FAITH:
   1406 
   1407 		case IPV6_RECVPKTINFO:
   1408 		case IPV6_RECVHOPLIMIT:
   1409 		case IPV6_RECVRTHDR:
   1410 		case IPV6_RECVPATHMTU:
   1411 		case IPV6_RECVTCLASS:
   1412 		case IPV6_V6ONLY:
   1413 			error = sockopt_getint(sopt, &optval);
   1414 			if (error)
   1415 				break;
   1416 			switch (optname) {
   1417 			case IPV6_UNICAST_HOPS:
   1418 				if (optval < -1 || optval >= 256)
   1419 					error = EINVAL;
   1420 				else {
   1421 					/* -1 = kernel default */
   1422 					in6p->in6p_hops = optval;
   1423 				}
   1424 				break;
   1425 #define OPTSET(bit) \
   1426 do { \
   1427 if (optval) \
   1428 	in6p->in6p_flags |= (bit); \
   1429 else \
   1430 	in6p->in6p_flags &= ~(bit); \
   1431 } while (/*CONSTCOND*/ 0)
   1432 
   1433 #ifdef RFC2292
   1434 #define OPTSET2292(bit) 			\
   1435 do { 						\
   1436 in6p->in6p_flags |= IN6P_RFC2292; 	\
   1437 if (optval) 				\
   1438 	in6p->in6p_flags |= (bit); 	\
   1439 else 					\
   1440 	in6p->in6p_flags &= ~(bit); 	\
   1441 } while (/*CONSTCOND*/ 0)
   1442 #endif
   1443 
   1444 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
   1445 
   1446 			case IPV6_RECVPKTINFO:
   1447 #ifdef RFC2292
   1448 				/* cannot mix with RFC2292 */
   1449 				if (OPTBIT(IN6P_RFC2292)) {
   1450 					error = EINVAL;
   1451 					break;
   1452 				}
   1453 #endif
   1454 				OPTSET(IN6P_PKTINFO);
   1455 				break;
   1456 
   1457 			case IPV6_HOPLIMIT:
   1458 			{
   1459 				struct ip6_pktopts **optp;
   1460 
   1461 #ifdef RFC2292
   1462 				/* cannot mix with RFC2292 */
   1463 				if (OPTBIT(IN6P_RFC2292)) {
   1464 					error = EINVAL;
   1465 					break;
   1466 				}
   1467 #endif
   1468 				optp = &in6p->in6p_outputopts;
   1469 				error = ip6_pcbopt(IPV6_HOPLIMIT,
   1470 						   (u_char *)&optval,
   1471 						   sizeof(optval),
   1472 						   optp,
   1473 						   kauth_cred_get(), uproto);
   1474 				break;
   1475 			}
   1476 
   1477 			case IPV6_RECVHOPLIMIT:
   1478 #ifdef RFC2292
   1479 				/* cannot mix with RFC2292 */
   1480 				if (OPTBIT(IN6P_RFC2292)) {
   1481 					error = EINVAL;
   1482 					break;
   1483 				}
   1484 #endif
   1485 				OPTSET(IN6P_HOPLIMIT);
   1486 				break;
   1487 
   1488 			case IPV6_RECVHOPOPTS:
   1489 #ifdef RFC2292
   1490 				/* cannot mix with RFC2292 */
   1491 				if (OPTBIT(IN6P_RFC2292)) {
   1492 					error = EINVAL;
   1493 					break;
   1494 				}
   1495 #endif
   1496 				OPTSET(IN6P_HOPOPTS);
   1497 				break;
   1498 
   1499 			case IPV6_RECVDSTOPTS:
   1500 #ifdef RFC2292
   1501 				/* cannot mix with RFC2292 */
   1502 				if (OPTBIT(IN6P_RFC2292)) {
   1503 					error = EINVAL;
   1504 					break;
   1505 				}
   1506 #endif
   1507 				OPTSET(IN6P_DSTOPTS);
   1508 				break;
   1509 
   1510 			case IPV6_RECVRTHDRDSTOPTS:
   1511 #ifdef RFC2292
   1512 				/* cannot mix with RFC2292 */
   1513 				if (OPTBIT(IN6P_RFC2292)) {
   1514 					error = EINVAL;
   1515 					break;
   1516 				}
   1517 #endif
   1518 				OPTSET(IN6P_RTHDRDSTOPTS);
   1519 				break;
   1520 
   1521 			case IPV6_RECVRTHDR:
   1522 #ifdef RFC2292
   1523 				/* cannot mix with RFC2292 */
   1524 				if (OPTBIT(IN6P_RFC2292)) {
   1525 					error = EINVAL;
   1526 					break;
   1527 				}
   1528 #endif
   1529 				OPTSET(IN6P_RTHDR);
   1530 				break;
   1531 
   1532 			case IPV6_FAITH:
   1533 				OPTSET(IN6P_FAITH);
   1534 				break;
   1535 
   1536 			case IPV6_RECVPATHMTU:
   1537 				/*
   1538 				 * We ignore this option for TCP
   1539 				 * sockets.
   1540 				 * (RFC3542 leaves this case
   1541 				 * unspecified.)
   1542 				 */
   1543 				if (uproto != IPPROTO_TCP)
   1544 					OPTSET(IN6P_MTU);
   1545 				break;
   1546 
   1547 			case IPV6_V6ONLY:
   1548 				/*
   1549 				 * make setsockopt(IPV6_V6ONLY)
   1550 				 * available only prior to bind(2).
   1551 				 * see ipng mailing list, Jun 22 2001.
   1552 				 */
   1553 				if (in6p->in6p_lport ||
   1554 				    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
   1555 					error = EINVAL;
   1556 					break;
   1557 				}
   1558 #ifdef INET6_BINDV6ONLY
   1559 				if (!optval)
   1560 					error = EINVAL;
   1561 #else
   1562 				OPTSET(IN6P_IPV6_V6ONLY);
   1563 #endif
   1564 				break;
   1565 			case IPV6_RECVTCLASS:
   1566 #ifdef RFC2292
   1567 				/* cannot mix with RFC2292 XXX */
   1568 				if (OPTBIT(IN6P_RFC2292)) {
   1569 					error = EINVAL;
   1570 					break;
   1571 				}
   1572 #endif
   1573 				OPTSET(IN6P_TCLASS);
   1574 				break;
   1575 
   1576 			}
   1577 			break;
   1578 
   1579 		case IPV6_OTCLASS:
   1580 		{
   1581 			struct ip6_pktopts **optp;
   1582 			u_int8_t tclass;
   1583 
   1584 			error = sockopt_get(sopt, &tclass, sizeof(tclass));
   1585 			if (error)
   1586 				break;
   1587 			optp = &in6p->in6p_outputopts;
   1588 			error = ip6_pcbopt(optname,
   1589 					   (u_char *)&tclass,
   1590 					   sizeof(tclass),
   1591 					   optp,
   1592 					   kauth_cred_get(), uproto);
   1593 			break;
   1594 		}
   1595 
   1596 		case IPV6_TCLASS:
   1597 		case IPV6_DONTFRAG:
   1598 		case IPV6_USE_MIN_MTU:
   1599 		case IPV6_PREFER_TEMPADDR:
   1600 			error = sockopt_getint(sopt, &optval);
   1601 			if (error)
   1602 				break;
   1603 			{
   1604 				struct ip6_pktopts **optp;
   1605 				optp = &in6p->in6p_outputopts;
   1606 				error = ip6_pcbopt(optname,
   1607 						   (u_char *)&optval,
   1608 						   sizeof(optval),
   1609 						   optp,
   1610 						   kauth_cred_get(), uproto);
   1611 				break;
   1612 			}
   1613 
   1614 #ifdef RFC2292
   1615 		case IPV6_2292PKTINFO:
   1616 		case IPV6_2292HOPLIMIT:
   1617 		case IPV6_2292HOPOPTS:
   1618 		case IPV6_2292DSTOPTS:
   1619 		case IPV6_2292RTHDR:
   1620 			/* RFC 2292 */
   1621 			error = sockopt_getint(sopt, &optval);
   1622 			if (error)
   1623 				break;
   1624 
   1625 			switch (optname) {
   1626 			case IPV6_2292PKTINFO:
   1627 				OPTSET2292(IN6P_PKTINFO);
   1628 				break;
   1629 			case IPV6_2292HOPLIMIT:
   1630 				OPTSET2292(IN6P_HOPLIMIT);
   1631 				break;
   1632 			case IPV6_2292HOPOPTS:
   1633 				/*
   1634 				 * Check super-user privilege.
   1635 				 * See comments for IPV6_RECVHOPOPTS.
   1636 				 */
   1637 				error =
   1638 				    kauth_authorize_network(kauth_cred_get(),
   1639 				    KAUTH_NETWORK_IPV6,
   1640 				    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL,
   1641 				    NULL, NULL);
   1642 				if (error)
   1643 					return (error);
   1644 				OPTSET2292(IN6P_HOPOPTS);
   1645 				break;
   1646 			case IPV6_2292DSTOPTS:
   1647 				error =
   1648 				    kauth_authorize_network(kauth_cred_get(),
   1649 				    KAUTH_NETWORK_IPV6,
   1650 				    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL,
   1651 				    NULL, NULL);
   1652 				if (error)
   1653 					return (error);
   1654 				OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
   1655 				break;
   1656 			case IPV6_2292RTHDR:
   1657 				OPTSET2292(IN6P_RTHDR);
   1658 				break;
   1659 			}
   1660 			break;
   1661 #endif
   1662 		case IPV6_PKTINFO:
   1663 		case IPV6_HOPOPTS:
   1664 		case IPV6_RTHDR:
   1665 		case IPV6_DSTOPTS:
   1666 		case IPV6_RTHDRDSTOPTS:
   1667 		case IPV6_NEXTHOP: {
   1668 			/* new advanced API (RFC3542) */
   1669 			void *optbuf;
   1670 			int optbuflen;
   1671 			struct ip6_pktopts **optp;
   1672 
   1673 #ifdef RFC2292
   1674 			/* cannot mix with RFC2292 */
   1675 			if (OPTBIT(IN6P_RFC2292)) {
   1676 				error = EINVAL;
   1677 				break;
   1678 			}
   1679 #endif
   1680 
   1681 			optbuflen = sopt->sopt_size;
   1682 			optbuf = malloc(optbuflen, M_IP6OPT, M_NOWAIT);
   1683 			if (optbuf == NULL) {
   1684 				error = ENOBUFS;
   1685 				break;
   1686 			}
   1687 
   1688 			error = sockopt_get(sopt, optbuf, optbuflen);
   1689 			if (error) {
   1690 				free(optbuf, M_IP6OPT);
   1691 				break;
   1692 			}
   1693 			optp = &in6p->in6p_outputopts;
   1694 			error = ip6_pcbopt(optname, optbuf, optbuflen,
   1695 			    optp, kauth_cred_get(), uproto);
   1696 
   1697 			free(optbuf, M_IP6OPT);
   1698 			break;
   1699 			}
   1700 #undef OPTSET
   1701 
   1702 		case IPV6_MULTICAST_IF:
   1703 		case IPV6_MULTICAST_HOPS:
   1704 		case IPV6_MULTICAST_LOOP:
   1705 		case IPV6_JOIN_GROUP:
   1706 		case IPV6_LEAVE_GROUP:
   1707 			error = ip6_setmoptions(sopt, in6p);
   1708 			break;
   1709 
   1710 		case IPV6_PORTRANGE:
   1711 			error = sockopt_getint(sopt, &optval);
   1712 			if (error)
   1713 				break;
   1714 
   1715 			switch (optval) {
   1716 			case IPV6_PORTRANGE_DEFAULT:
   1717 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1718 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1719 				break;
   1720 
   1721 			case IPV6_PORTRANGE_HIGH:
   1722 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1723 				in6p->in6p_flags |= IN6P_HIGHPORT;
   1724 				break;
   1725 
   1726 			case IPV6_PORTRANGE_LOW:
   1727 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1728 				in6p->in6p_flags |= IN6P_LOWPORT;
   1729 				break;
   1730 
   1731 			default:
   1732 				error = EINVAL;
   1733 				break;
   1734 			}
   1735 			break;
   1736 
   1737 		case IPV6_PORTALGO:
   1738 			error = sockopt_getint(sopt, &optval);
   1739 			if (error)
   1740 				break;
   1741 
   1742 			error = portalgo_algo_index_select(
   1743 			    (struct inpcb_hdr *)in6p, optval);
   1744 			break;
   1745 
   1746 #if defined(IPSEC)
   1747 		case IPV6_IPSEC_POLICY:
   1748 			if (ipsec_enabled) {
   1749 				error = ipsec_set_policy(in6p,
   1750 				    sopt->sopt_data, sopt->sopt_size,
   1751 				    kauth_cred_get());
   1752 				break;
   1753 			}
   1754 			/*FALLTHROUGH*/
   1755 #endif /* IPSEC */
   1756 
   1757 		default:
   1758 			error = ENOPROTOOPT;
   1759 			break;
   1760 		}
   1761 		break;
   1762 
   1763 	case PRCO_GETOPT:
   1764 		switch (optname) {
   1765 #ifdef RFC2292
   1766 		case IPV6_2292PKTOPTIONS:
   1767 			/*
   1768 			 * RFC3542 (effectively) deprecated the
   1769 			 * semantics of the 2292-style pktoptions.
   1770 			 * Since it was not reliable in nature (i.e.,
   1771 			 * applications had to expect the lack of some
   1772 			 * information after all), it would make sense
   1773 			 * to simplify this part by always returning
   1774 			 * empty data.
   1775 			 */
   1776 			break;
   1777 #endif
   1778 
   1779 		case IPV6_RECVHOPOPTS:
   1780 		case IPV6_RECVDSTOPTS:
   1781 		case IPV6_RECVRTHDRDSTOPTS:
   1782 		case IPV6_UNICAST_HOPS:
   1783 		case IPV6_RECVPKTINFO:
   1784 		case IPV6_RECVHOPLIMIT:
   1785 		case IPV6_RECVRTHDR:
   1786 		case IPV6_RECVPATHMTU:
   1787 
   1788 		case IPV6_FAITH:
   1789 		case IPV6_V6ONLY:
   1790 		case IPV6_PORTRANGE:
   1791 		case IPV6_RECVTCLASS:
   1792 			switch (optname) {
   1793 
   1794 			case IPV6_RECVHOPOPTS:
   1795 				optval = OPTBIT(IN6P_HOPOPTS);
   1796 				break;
   1797 
   1798 			case IPV6_RECVDSTOPTS:
   1799 				optval = OPTBIT(IN6P_DSTOPTS);
   1800 				break;
   1801 
   1802 			case IPV6_RECVRTHDRDSTOPTS:
   1803 				optval = OPTBIT(IN6P_RTHDRDSTOPTS);
   1804 				break;
   1805 
   1806 			case IPV6_UNICAST_HOPS:
   1807 				optval = in6p->in6p_hops;
   1808 				break;
   1809 
   1810 			case IPV6_RECVPKTINFO:
   1811 				optval = OPTBIT(IN6P_PKTINFO);
   1812 				break;
   1813 
   1814 			case IPV6_RECVHOPLIMIT:
   1815 				optval = OPTBIT(IN6P_HOPLIMIT);
   1816 				break;
   1817 
   1818 			case IPV6_RECVRTHDR:
   1819 				optval = OPTBIT(IN6P_RTHDR);
   1820 				break;
   1821 
   1822 			case IPV6_RECVPATHMTU:
   1823 				optval = OPTBIT(IN6P_MTU);
   1824 				break;
   1825 
   1826 			case IPV6_FAITH:
   1827 				optval = OPTBIT(IN6P_FAITH);
   1828 				break;
   1829 
   1830 			case IPV6_V6ONLY:
   1831 				optval = OPTBIT(IN6P_IPV6_V6ONLY);
   1832 				break;
   1833 
   1834 			case IPV6_PORTRANGE:
   1835 			    {
   1836 				int flags;
   1837 				flags = in6p->in6p_flags;
   1838 				if (flags & IN6P_HIGHPORT)
   1839 					optval = IPV6_PORTRANGE_HIGH;
   1840 				else if (flags & IN6P_LOWPORT)
   1841 					optval = IPV6_PORTRANGE_LOW;
   1842 				else
   1843 					optval = 0;
   1844 				break;
   1845 			    }
   1846 			case IPV6_RECVTCLASS:
   1847 				optval = OPTBIT(IN6P_TCLASS);
   1848 				break;
   1849 
   1850 			}
   1851 			if (error)
   1852 				break;
   1853 			error = sockopt_setint(sopt, optval);
   1854 			break;
   1855 
   1856 		case IPV6_PATHMTU:
   1857 		    {
   1858 			u_long pmtu = 0;
   1859 			struct ip6_mtuinfo mtuinfo;
   1860 			struct route *ro = &in6p->in6p_route;
   1861 			struct rtentry *rt;
   1862 			union {
   1863 				struct sockaddr		dst;
   1864 				struct sockaddr_in6	dst6;
   1865 			} u;
   1866 
   1867 			if (!(so->so_state & SS_ISCONNECTED))
   1868 				return (ENOTCONN);
   1869 			/*
   1870 			 * XXX: we dot not consider the case of source
   1871 			 * routing, or optional information to specify
   1872 			 * the outgoing interface.
   1873 			 */
   1874 			sockaddr_in6_init(&u.dst6, &in6p->in6p_faddr, 0, 0, 0);
   1875 			rt = rtcache_lookup(ro, &u.dst);
   1876 			error = ip6_getpmtu(rt, NULL, &pmtu, NULL);
   1877 			rtcache_unref(rt, ro);
   1878 			if (error)
   1879 				break;
   1880 			if (pmtu > IPV6_MAXPACKET)
   1881 				pmtu = IPV6_MAXPACKET;
   1882 
   1883 			memset(&mtuinfo, 0, sizeof(mtuinfo));
   1884 			mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
   1885 			optdata = (void *)&mtuinfo;
   1886 			optdatalen = sizeof(mtuinfo);
   1887 			if (optdatalen > MCLBYTES)
   1888 				return (EMSGSIZE); /* XXX */
   1889 			error = sockopt_set(sopt, optdata, optdatalen);
   1890 			break;
   1891 		    }
   1892 
   1893 #ifdef RFC2292
   1894 		case IPV6_2292PKTINFO:
   1895 		case IPV6_2292HOPLIMIT:
   1896 		case IPV6_2292HOPOPTS:
   1897 		case IPV6_2292RTHDR:
   1898 		case IPV6_2292DSTOPTS:
   1899 			switch (optname) {
   1900 			case IPV6_2292PKTINFO:
   1901 				optval = OPTBIT(IN6P_PKTINFO);
   1902 				break;
   1903 			case IPV6_2292HOPLIMIT:
   1904 				optval = OPTBIT(IN6P_HOPLIMIT);
   1905 				break;
   1906 			case IPV6_2292HOPOPTS:
   1907 				optval = OPTBIT(IN6P_HOPOPTS);
   1908 				break;
   1909 			case IPV6_2292RTHDR:
   1910 				optval = OPTBIT(IN6P_RTHDR);
   1911 				break;
   1912 			case IPV6_2292DSTOPTS:
   1913 				optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
   1914 				break;
   1915 			}
   1916 			error = sockopt_setint(sopt, optval);
   1917 			break;
   1918 #endif
   1919 		case IPV6_PKTINFO:
   1920 		case IPV6_HOPOPTS:
   1921 		case IPV6_RTHDR:
   1922 		case IPV6_DSTOPTS:
   1923 		case IPV6_RTHDRDSTOPTS:
   1924 		case IPV6_NEXTHOP:
   1925 		case IPV6_OTCLASS:
   1926 		case IPV6_TCLASS:
   1927 		case IPV6_DONTFRAG:
   1928 		case IPV6_USE_MIN_MTU:
   1929 		case IPV6_PREFER_TEMPADDR:
   1930 			error = ip6_getpcbopt(in6p->in6p_outputopts,
   1931 			    optname, sopt);
   1932 			break;
   1933 
   1934 		case IPV6_MULTICAST_IF:
   1935 		case IPV6_MULTICAST_HOPS:
   1936 		case IPV6_MULTICAST_LOOP:
   1937 		case IPV6_JOIN_GROUP:
   1938 		case IPV6_LEAVE_GROUP:
   1939 			error = ip6_getmoptions(sopt, in6p);
   1940 			break;
   1941 
   1942 		case IPV6_PORTALGO:
   1943 			optval = ((struct inpcb_hdr *)in6p)->inph_portalgo;
   1944 			error = sockopt_setint(sopt, optval);
   1945 			break;
   1946 
   1947 #if defined(IPSEC)
   1948 		case IPV6_IPSEC_POLICY:
   1949 			if (ipsec_used) {
   1950 				struct mbuf *m = NULL;
   1951 
   1952 				/*
   1953 				 * XXX: this will return EINVAL as sopt is
   1954 				 * empty
   1955 				 */
   1956 				error = ipsec_get_policy(in6p, sopt->sopt_data,
   1957 				    sopt->sopt_size, &m);
   1958 				if (!error)
   1959 					error = sockopt_setmbuf(sopt, m);
   1960 				break;
   1961 			}
   1962 			/*FALLTHROUGH*/
   1963 #endif /* IPSEC */
   1964 
   1965 		default:
   1966 			error = ENOPROTOOPT;
   1967 			break;
   1968 		}
   1969 		break;
   1970 	}
   1971 	return (error);
   1972 }
   1973 
   1974 int
   1975 ip6_raw_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   1976 {
   1977 	int error = 0, optval;
   1978 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
   1979 	struct in6pcb *in6p = sotoin6pcb(so);
   1980 	int level, optname;
   1981 
   1982 	KASSERT(sopt != NULL);
   1983 
   1984 	level = sopt->sopt_level;
   1985 	optname = sopt->sopt_name;
   1986 
   1987 	if (level != IPPROTO_IPV6) {
   1988 		return ENOPROTOOPT;
   1989 	}
   1990 
   1991 	switch (optname) {
   1992 	case IPV6_CHECKSUM:
   1993 		/*
   1994 		 * For ICMPv6 sockets, no modification allowed for checksum
   1995 		 * offset, permit "no change" values to help existing apps.
   1996 		 *
   1997 		 * XXX RFC3542 says: "An attempt to set IPV6_CHECKSUM
   1998 		 * for an ICMPv6 socket will fail."  The current
   1999 		 * behavior does not meet RFC3542.
   2000 		 */
   2001 		switch (op) {
   2002 		case PRCO_SETOPT:
   2003 			error = sockopt_getint(sopt, &optval);
   2004 			if (error)
   2005 				break;
   2006 			if ((optval % 2) != 0) {
   2007 				/* the API assumes even offset values */
   2008 				error = EINVAL;
   2009 			} else if (so->so_proto->pr_protocol ==
   2010 			    IPPROTO_ICMPV6) {
   2011 				if (optval != icmp6off)
   2012 					error = EINVAL;
   2013 			} else
   2014 				in6p->in6p_cksum = optval;
   2015 			break;
   2016 
   2017 		case PRCO_GETOPT:
   2018 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
   2019 				optval = icmp6off;
   2020 			else
   2021 				optval = in6p->in6p_cksum;
   2022 
   2023 			error = sockopt_setint(sopt, optval);
   2024 			break;
   2025 
   2026 		default:
   2027 			error = EINVAL;
   2028 			break;
   2029 		}
   2030 		break;
   2031 
   2032 	default:
   2033 		error = ENOPROTOOPT;
   2034 		break;
   2035 	}
   2036 
   2037 	return (error);
   2038 }
   2039 
   2040 #ifdef RFC2292
   2041 /*
   2042  * Set up IP6 options in pcb for insertion in output packets or
   2043  * specifying behavior of outgoing packets.
   2044  */
   2045 static int
   2046 ip6_pcbopts(struct ip6_pktopts **pktopt, struct socket *so,
   2047     struct sockopt *sopt)
   2048 {
   2049 	struct ip6_pktopts *opt = *pktopt;
   2050 	struct mbuf *m;
   2051 	int error = 0;
   2052 
   2053 	KASSERT(solocked(so));
   2054 
   2055 	/* turn off any old options. */
   2056 	if (opt) {
   2057 #ifdef DIAGNOSTIC
   2058 	    if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
   2059 		opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
   2060 		opt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2061 		    printf("ip6_pcbopts: all specified options are cleared.\n");
   2062 #endif
   2063 		ip6_clearpktopts(opt, -1);
   2064 	} else {
   2065 		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
   2066 		if (opt == NULL)
   2067 			return (ENOBUFS);
   2068 	}
   2069 	*pktopt = NULL;
   2070 
   2071 	if (sopt == NULL || sopt->sopt_size == 0) {
   2072 		/*
   2073 		 * Only turning off any previous options, regardless of
   2074 		 * whether the opt is just created or given.
   2075 		 */
   2076 		free(opt, M_IP6OPT);
   2077 		return (0);
   2078 	}
   2079 
   2080 	/*  set options specified by user. */
   2081 	m = sockopt_getmbuf(sopt);
   2082 	if (m == NULL) {
   2083 		free(opt, M_IP6OPT);
   2084 		return (ENOBUFS);
   2085 	}
   2086 
   2087 	error = ip6_setpktopts(m, opt, NULL, kauth_cred_get(),
   2088 	    so->so_proto->pr_protocol);
   2089 	m_freem(m);
   2090 	if (error != 0) {
   2091 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
   2092 		free(opt, M_IP6OPT);
   2093 		return (error);
   2094 	}
   2095 	*pktopt = opt;
   2096 	return (0);
   2097 }
   2098 #endif
   2099 
   2100 /*
   2101  * initialize ip6_pktopts.  beware that there are non-zero default values in
   2102  * the struct.
   2103  */
   2104 void
   2105 ip6_initpktopts(struct ip6_pktopts *opt)
   2106 {
   2107 
   2108 	memset(opt, 0, sizeof(*opt));
   2109 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
   2110 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
   2111 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
   2112 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
   2113 }
   2114 
   2115 #define sin6tosa(sin6)	((struct sockaddr *)(sin6)) /* XXX */
   2116 static int
   2117 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
   2118     kauth_cred_t cred, int uproto)
   2119 {
   2120 	struct ip6_pktopts *opt;
   2121 
   2122 	if (*pktopt == NULL) {
   2123 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
   2124 		    M_NOWAIT);
   2125 		if (*pktopt == NULL)
   2126 			return (ENOBUFS);
   2127 
   2128 		ip6_initpktopts(*pktopt);
   2129 	}
   2130 	opt = *pktopt;
   2131 
   2132 	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
   2133 }
   2134 
   2135 static int
   2136 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
   2137 {
   2138 	void *optdata = NULL;
   2139 	int optdatalen = 0;
   2140 	struct ip6_ext *ip6e;
   2141 	int error = 0;
   2142 	struct in6_pktinfo null_pktinfo;
   2143 	int deftclass = 0, on;
   2144 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
   2145 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
   2146 
   2147 	switch (optname) {
   2148 	case IPV6_PKTINFO:
   2149 		if (pktopt && pktopt->ip6po_pktinfo)
   2150 			optdata = (void *)pktopt->ip6po_pktinfo;
   2151 		else {
   2152 			/* XXX: we don't have to do this every time... */
   2153 			memset(&null_pktinfo, 0, sizeof(null_pktinfo));
   2154 			optdata = (void *)&null_pktinfo;
   2155 		}
   2156 		optdatalen = sizeof(struct in6_pktinfo);
   2157 		break;
   2158 	case IPV6_OTCLASS:
   2159 		/* XXX */
   2160 		return (EINVAL);
   2161 	case IPV6_TCLASS:
   2162 		if (pktopt && pktopt->ip6po_tclass >= 0)
   2163 			optdata = (void *)&pktopt->ip6po_tclass;
   2164 		else
   2165 			optdata = (void *)&deftclass;
   2166 		optdatalen = sizeof(int);
   2167 		break;
   2168 	case IPV6_HOPOPTS:
   2169 		if (pktopt && pktopt->ip6po_hbh) {
   2170 			optdata = (void *)pktopt->ip6po_hbh;
   2171 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
   2172 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2173 		}
   2174 		break;
   2175 	case IPV6_RTHDR:
   2176 		if (pktopt && pktopt->ip6po_rthdr) {
   2177 			optdata = (void *)pktopt->ip6po_rthdr;
   2178 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
   2179 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2180 		}
   2181 		break;
   2182 	case IPV6_RTHDRDSTOPTS:
   2183 		if (pktopt && pktopt->ip6po_dest1) {
   2184 			optdata = (void *)pktopt->ip6po_dest1;
   2185 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
   2186 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2187 		}
   2188 		break;
   2189 	case IPV6_DSTOPTS:
   2190 		if (pktopt && pktopt->ip6po_dest2) {
   2191 			optdata = (void *)pktopt->ip6po_dest2;
   2192 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
   2193 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2194 		}
   2195 		break;
   2196 	case IPV6_NEXTHOP:
   2197 		if (pktopt && pktopt->ip6po_nexthop) {
   2198 			optdata = (void *)pktopt->ip6po_nexthop;
   2199 			optdatalen = pktopt->ip6po_nexthop->sa_len;
   2200 		}
   2201 		break;
   2202 	case IPV6_USE_MIN_MTU:
   2203 		if (pktopt)
   2204 			optdata = (void *)&pktopt->ip6po_minmtu;
   2205 		else
   2206 			optdata = (void *)&defminmtu;
   2207 		optdatalen = sizeof(int);
   2208 		break;
   2209 	case IPV6_DONTFRAG:
   2210 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
   2211 			on = 1;
   2212 		else
   2213 			on = 0;
   2214 		optdata = (void *)&on;
   2215 		optdatalen = sizeof(on);
   2216 		break;
   2217 	case IPV6_PREFER_TEMPADDR:
   2218 		if (pktopt)
   2219 			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
   2220 		else
   2221 			optdata = (void *)&defpreftemp;
   2222 		optdatalen = sizeof(int);
   2223 		break;
   2224 	default:		/* should not happen */
   2225 #ifdef DIAGNOSTIC
   2226 		panic("ip6_getpcbopt: unexpected option\n");
   2227 #endif
   2228 		return (ENOPROTOOPT);
   2229 	}
   2230 
   2231 	error = sockopt_set(sopt, optdata, optdatalen);
   2232 
   2233 	return (error);
   2234 }
   2235 
   2236 void
   2237 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
   2238 {
   2239 	if (optname == -1 || optname == IPV6_PKTINFO) {
   2240 		if (pktopt->ip6po_pktinfo)
   2241 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
   2242 		pktopt->ip6po_pktinfo = NULL;
   2243 	}
   2244 	if (optname == -1 || optname == IPV6_HOPLIMIT)
   2245 		pktopt->ip6po_hlim = -1;
   2246 	if (optname == -1 || optname == IPV6_TCLASS)
   2247 		pktopt->ip6po_tclass = -1;
   2248 	if (optname == -1 || optname == IPV6_NEXTHOP) {
   2249 		rtcache_free(&pktopt->ip6po_nextroute);
   2250 		if (pktopt->ip6po_nexthop)
   2251 			free(pktopt->ip6po_nexthop, M_IP6OPT);
   2252 		pktopt->ip6po_nexthop = NULL;
   2253 	}
   2254 	if (optname == -1 || optname == IPV6_HOPOPTS) {
   2255 		if (pktopt->ip6po_hbh)
   2256 			free(pktopt->ip6po_hbh, M_IP6OPT);
   2257 		pktopt->ip6po_hbh = NULL;
   2258 	}
   2259 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
   2260 		if (pktopt->ip6po_dest1)
   2261 			free(pktopt->ip6po_dest1, M_IP6OPT);
   2262 		pktopt->ip6po_dest1 = NULL;
   2263 	}
   2264 	if (optname == -1 || optname == IPV6_RTHDR) {
   2265 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2266 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
   2267 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
   2268 		rtcache_free(&pktopt->ip6po_route);
   2269 	}
   2270 	if (optname == -1 || optname == IPV6_DSTOPTS) {
   2271 		if (pktopt->ip6po_dest2)
   2272 			free(pktopt->ip6po_dest2, M_IP6OPT);
   2273 		pktopt->ip6po_dest2 = NULL;
   2274 	}
   2275 }
   2276 
   2277 #define PKTOPT_EXTHDRCPY(type) 					\
   2278 do {								\
   2279 	if (src->type) {					\
   2280 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
   2281 		dst->type = malloc(hlen, M_IP6OPT, canwait);	\
   2282 		if (dst->type == NULL)				\
   2283 			goto bad;				\
   2284 		memcpy(dst->type, src->type, hlen);		\
   2285 	}							\
   2286 } while (/*CONSTCOND*/ 0)
   2287 
   2288 static int
   2289 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
   2290 {
   2291 	dst->ip6po_hlim = src->ip6po_hlim;
   2292 	dst->ip6po_tclass = src->ip6po_tclass;
   2293 	dst->ip6po_flags = src->ip6po_flags;
   2294 	dst->ip6po_minmtu = src->ip6po_minmtu;
   2295 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
   2296 	if (src->ip6po_pktinfo) {
   2297 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
   2298 		    M_IP6OPT, canwait);
   2299 		if (dst->ip6po_pktinfo == NULL)
   2300 			goto bad;
   2301 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
   2302 	}
   2303 	if (src->ip6po_nexthop) {
   2304 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
   2305 		    M_IP6OPT, canwait);
   2306 		if (dst->ip6po_nexthop == NULL)
   2307 			goto bad;
   2308 		memcpy(dst->ip6po_nexthop, src->ip6po_nexthop,
   2309 		    src->ip6po_nexthop->sa_len);
   2310 	}
   2311 	PKTOPT_EXTHDRCPY(ip6po_hbh);
   2312 	PKTOPT_EXTHDRCPY(ip6po_dest1);
   2313 	PKTOPT_EXTHDRCPY(ip6po_dest2);
   2314 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
   2315 	return (0);
   2316 
   2317   bad:
   2318 	if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
   2319 	if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
   2320 	if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
   2321 	if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
   2322 	if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
   2323 	if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
   2324 
   2325 	return (ENOBUFS);
   2326 }
   2327 #undef PKTOPT_EXTHDRCPY
   2328 
   2329 struct ip6_pktopts *
   2330 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
   2331 {
   2332 	int error;
   2333 	struct ip6_pktopts *dst;
   2334 
   2335 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
   2336 	if (dst == NULL)
   2337 		return (NULL);
   2338 	ip6_initpktopts(dst);
   2339 
   2340 	if ((error = copypktopts(dst, src, canwait)) != 0) {
   2341 		free(dst, M_IP6OPT);
   2342 		return (NULL);
   2343 	}
   2344 
   2345 	return (dst);
   2346 }
   2347 
   2348 void
   2349 ip6_freepcbopts(struct ip6_pktopts *pktopt)
   2350 {
   2351 	if (pktopt == NULL)
   2352 		return;
   2353 
   2354 	ip6_clearpktopts(pktopt, -1);
   2355 
   2356 	free(pktopt, M_IP6OPT);
   2357 }
   2358 
   2359 int
   2360 ip6_get_membership(const struct sockopt *sopt, struct ifnet **ifp,
   2361     struct psref *psref, void *v, size_t l)
   2362 {
   2363 	struct ipv6_mreq mreq;
   2364 	int error;
   2365 	struct in6_addr *ia = &mreq.ipv6mr_multiaddr;
   2366 	struct in_addr *ia4 = (void *)&ia->s6_addr32[3];
   2367 
   2368 	error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2369 	if (error != 0)
   2370 		return error;
   2371 
   2372 	if (IN6_IS_ADDR_UNSPECIFIED(ia)) {
   2373 		/*
   2374 		 * We use the unspecified address to specify to accept
   2375 		 * all multicast addresses. Only super user is allowed
   2376 		 * to do this.
   2377 		 */
   2378 		if (kauth_authorize_network(curlwp->l_cred, KAUTH_NETWORK_IPV6,
   2379 		    KAUTH_REQ_NETWORK_IPV6_JOIN_MULTICAST, NULL, NULL, NULL))
   2380 			return EACCES;
   2381 	} else if (IN6_IS_ADDR_V4MAPPED(ia)) {
   2382 		// Don't bother if we are not going to use ifp.
   2383 		if (l == sizeof(*ia)) {
   2384 			memcpy(v, ia, l);
   2385 			return 0;
   2386 		}
   2387 	} else if (!IN6_IS_ADDR_MULTICAST(ia)) {
   2388 		return EINVAL;
   2389 	}
   2390 
   2391 	/*
   2392 	 * If no interface was explicitly specified, choose an
   2393 	 * appropriate one according to the given multicast address.
   2394 	 */
   2395 	if (mreq.ipv6mr_interface == 0) {
   2396 		struct rtentry *rt;
   2397 		union {
   2398 			struct sockaddr		dst;
   2399 			struct sockaddr_in	dst4;
   2400 			struct sockaddr_in6	dst6;
   2401 		} u;
   2402 		struct route ro;
   2403 
   2404 		/*
   2405 		 * Look up the routing table for the
   2406 		 * address, and choose the outgoing interface.
   2407 		 *   XXX: is it a good approach?
   2408 		 */
   2409 		memset(&ro, 0, sizeof(ro));
   2410 		if (IN6_IS_ADDR_V4MAPPED(ia))
   2411 			sockaddr_in_init(&u.dst4, ia4, 0);
   2412 		else
   2413 			sockaddr_in6_init(&u.dst6, ia, 0, 0, 0);
   2414 		error = rtcache_setdst(&ro, &u.dst);
   2415 		if (error != 0)
   2416 			return error;
   2417 		rt = rtcache_init(&ro);
   2418 		*ifp = rt != NULL ?
   2419 		    if_get_byindex(rt->rt_ifp->if_index, psref) : NULL;
   2420 		rtcache_unref(rt, &ro);
   2421 		rtcache_free(&ro);
   2422 	} else {
   2423 		/*
   2424 		 * If the interface is specified, validate it.
   2425 		 */
   2426 		*ifp = if_get_byindex(mreq.ipv6mr_interface, psref);
   2427 		if (*ifp == NULL)
   2428 			return ENXIO;	/* XXX EINVAL? */
   2429 	}
   2430 	if (sizeof(*ia) == l)
   2431 		memcpy(v, ia, l);
   2432 	else
   2433 		memcpy(v, ia4, l);
   2434 	return 0;
   2435 }
   2436 
   2437 /*
   2438  * Set the IP6 multicast options in response to user setsockopt().
   2439  */
   2440 static int
   2441 ip6_setmoptions(const struct sockopt *sopt, struct in6pcb *in6p)
   2442 {
   2443 	int error = 0;
   2444 	u_int loop, ifindex;
   2445 	struct ipv6_mreq mreq;
   2446 	struct in6_addr ia;
   2447 	struct ifnet *ifp;
   2448 	struct ip6_moptions *im6o = in6p->in6p_moptions;
   2449 	struct in6_multi_mship *imm;
   2450 
   2451 	KASSERT(in6p_locked(in6p));
   2452 
   2453 	if (im6o == NULL) {
   2454 		/*
   2455 		 * No multicast option buffer attached to the pcb;
   2456 		 * allocate one and initialize to default values.
   2457 		 */
   2458 		im6o = malloc(sizeof(*im6o), M_IPMOPTS, M_NOWAIT);
   2459 		if (im6o == NULL)
   2460 			return (ENOBUFS);
   2461 		in6p->in6p_moptions = im6o;
   2462 		im6o->im6o_multicast_if_index = 0;
   2463 		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2464 		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
   2465 		LIST_INIT(&im6o->im6o_memberships);
   2466 	}
   2467 
   2468 	switch (sopt->sopt_name) {
   2469 
   2470 	case IPV6_MULTICAST_IF: {
   2471 		int s;
   2472 		/*
   2473 		 * Select the interface for outgoing multicast packets.
   2474 		 */
   2475 		error = sockopt_get(sopt, &ifindex, sizeof(ifindex));
   2476 		if (error != 0)
   2477 			break;
   2478 
   2479 		s = pserialize_read_enter();
   2480 		if (ifindex != 0) {
   2481 			if ((ifp = if_byindex(ifindex)) == NULL) {
   2482 				pserialize_read_exit(s);
   2483 				error = ENXIO;	/* XXX EINVAL? */
   2484 				break;
   2485 			}
   2486 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
   2487 				pserialize_read_exit(s);
   2488 				error = EADDRNOTAVAIL;
   2489 				break;
   2490 			}
   2491 		} else
   2492 			ifp = NULL;
   2493 		im6o->im6o_multicast_if_index = if_get_index(ifp);
   2494 		pserialize_read_exit(s);
   2495 		break;
   2496 	    }
   2497 
   2498 	case IPV6_MULTICAST_HOPS:
   2499 	    {
   2500 		/*
   2501 		 * Set the IP6 hoplimit for outgoing multicast packets.
   2502 		 */
   2503 		int optval;
   2504 
   2505 		error = sockopt_getint(sopt, &optval);
   2506 		if (error != 0)
   2507 			break;
   2508 
   2509 		if (optval < -1 || optval >= 256)
   2510 			error = EINVAL;
   2511 		else if (optval == -1)
   2512 			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2513 		else
   2514 			im6o->im6o_multicast_hlim = optval;
   2515 		break;
   2516 	    }
   2517 
   2518 	case IPV6_MULTICAST_LOOP:
   2519 		/*
   2520 		 * Set the loopback flag for outgoing multicast packets.
   2521 		 * Must be zero or one.
   2522 		 */
   2523 		error = sockopt_get(sopt, &loop, sizeof(loop));
   2524 		if (error != 0)
   2525 			break;
   2526 		if (loop > 1) {
   2527 			error = EINVAL;
   2528 			break;
   2529 		}
   2530 		im6o->im6o_multicast_loop = loop;
   2531 		break;
   2532 
   2533 	case IPV6_JOIN_GROUP: {
   2534 		int bound;
   2535 		struct psref psref;
   2536 		/*
   2537 		 * Add a multicast group membership.
   2538 		 * Group must be a valid IP6 multicast address.
   2539 		 */
   2540 		bound = curlwp_bind();
   2541 		ifp = NULL;
   2542 		error = ip6_get_membership(sopt, &ifp, &psref, &ia, sizeof(ia));
   2543 		if (error != 0) {
   2544 			KASSERT(ifp == NULL);
   2545 			curlwp_bindx(bound);
   2546 			return error;
   2547 		}
   2548 
   2549 		if (IN6_IS_ADDR_V4MAPPED(&ia)) {
   2550 			error = ip_setmoptions(&in6p->in6p_v4moptions, sopt);
   2551 			goto put_break;
   2552 		}
   2553 		/*
   2554 		 * See if we found an interface, and confirm that it
   2555 		 * supports multicast
   2556 		 */
   2557 		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
   2558 			error = EADDRNOTAVAIL;
   2559 			goto put_break;
   2560 		}
   2561 
   2562 		if (in6_setscope(&ia, ifp, NULL)) {
   2563 			error = EADDRNOTAVAIL; /* XXX: should not happen */
   2564 			goto put_break;
   2565 		}
   2566 
   2567 		/*
   2568 		 * See if the membership already exists.
   2569 		 */
   2570 		LIST_FOREACH(imm, &im6o->im6o_memberships, i6mm_chain) {
   2571 			if (imm->i6mm_maddr->in6m_ifp == ifp &&
   2572 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2573 			    &ia))
   2574 				goto put_break;
   2575 		}
   2576 		if (imm != NULL) {
   2577 			error = EADDRINUSE;
   2578 			goto put_break;
   2579 		}
   2580 		/*
   2581 		 * Everything looks good; add a new record to the multicast
   2582 		 * address list for the given interface.
   2583 		 */
   2584 		IFNET_LOCK(ifp);
   2585 		imm = in6_joingroup(ifp, &ia, &error, 0);
   2586 		IFNET_UNLOCK(ifp);
   2587 		if (imm == NULL)
   2588 			goto put_break;
   2589 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
   2590 	    put_break:
   2591 		if_put(ifp, &psref);
   2592 		curlwp_bindx(bound);
   2593 		break;
   2594 	    }
   2595 
   2596 	case IPV6_LEAVE_GROUP: {
   2597 		struct ifnet *in6m_ifp;
   2598 		/*
   2599 		 * Drop a multicast group membership.
   2600 		 * Group must be a valid IP6 multicast address.
   2601 		 */
   2602 		error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2603 		if (error != 0)
   2604 			break;
   2605 
   2606 		if (IN6_IS_ADDR_V4MAPPED(&mreq.ipv6mr_multiaddr)) {
   2607 			error = ip_setmoptions(&in6p->in6p_v4moptions, sopt);
   2608 			break;
   2609 		}
   2610 		/*
   2611 		 * If an interface address was specified, get a pointer
   2612 		 * to its ifnet structure.
   2613 		 */
   2614 		if (mreq.ipv6mr_interface != 0) {
   2615 			if ((ifp = if_byindex(mreq.ipv6mr_interface)) == NULL) {
   2616 				error = ENXIO;	/* XXX EINVAL? */
   2617 				break;
   2618 			}
   2619 		} else
   2620 			ifp = NULL;
   2621 
   2622 		/* Fill in the scope zone ID */
   2623 		if (ifp) {
   2624 			if (in6_setscope(&mreq.ipv6mr_multiaddr, ifp, NULL)) {
   2625 				/* XXX: should not happen */
   2626 				error = EADDRNOTAVAIL;
   2627 				break;
   2628 			}
   2629 		} else if (mreq.ipv6mr_interface != 0) {
   2630 			/*
   2631 			 * XXX: This case would happens when the (positive)
   2632 			 * index is in the valid range, but the corresponding
   2633 			 * interface has been detached dynamically.  The above
   2634 			 * check probably avoids such case to happen here, but
   2635 			 * we check it explicitly for safety.
   2636 			 */
   2637 			error = EADDRNOTAVAIL;
   2638 			break;
   2639 		} else {	/* ipv6mr_interface == 0 */
   2640 			struct sockaddr_in6 sa6_mc;
   2641 
   2642 			/*
   2643 			 * The API spec says as follows:
   2644 			 *  If the interface index is specified as 0, the
   2645 			 *  system may choose a multicast group membership to
   2646 			 *  drop by matching the multicast address only.
   2647 			 * On the other hand, we cannot disambiguate the scope
   2648 			 * zone unless an interface is provided.  Thus, we
   2649 			 * check if there's ambiguity with the default scope
   2650 			 * zone as the last resort.
   2651 			 */
   2652 			sockaddr_in6_init(&sa6_mc, &mreq.ipv6mr_multiaddr,
   2653 			    0, 0, 0);
   2654 			error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
   2655 			if (error != 0)
   2656 				break;
   2657 			mreq.ipv6mr_multiaddr = sa6_mc.sin6_addr;
   2658 		}
   2659 
   2660 		/*
   2661 		 * Find the membership in the membership list.
   2662 		 */
   2663 		LIST_FOREACH(imm, &im6o->im6o_memberships, i6mm_chain) {
   2664 			if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
   2665 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2666 			    &mreq.ipv6mr_multiaddr))
   2667 				break;
   2668 		}
   2669 		if (imm == NULL) {
   2670 			/* Unable to resolve interface */
   2671 			error = EADDRNOTAVAIL;
   2672 			break;
   2673 		}
   2674 		/*
   2675 		 * Give up the multicast address record to which the
   2676 		 * membership points.
   2677 		 */
   2678 		LIST_REMOVE(imm, i6mm_chain);
   2679 		in6m_ifp = imm->i6mm_maddr->in6m_ifp;
   2680 		IFNET_LOCK(in6m_ifp);
   2681 		in6_leavegroup(imm);
   2682 		/* in6m_ifp should not leave thanks to in6p_lock */
   2683 		IFNET_UNLOCK(in6m_ifp);
   2684 		break;
   2685 	    }
   2686 
   2687 	default:
   2688 		error = EOPNOTSUPP;
   2689 		break;
   2690 	}
   2691 
   2692 	/*
   2693 	 * If all options have default values, no need to keep the mbuf.
   2694 	 */
   2695 	if (im6o->im6o_multicast_if_index == 0 &&
   2696 	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
   2697 	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
   2698 	    LIST_EMPTY(&im6o->im6o_memberships)) {
   2699 		free(in6p->in6p_moptions, M_IPMOPTS);
   2700 		in6p->in6p_moptions = NULL;
   2701 	}
   2702 
   2703 	return (error);
   2704 }
   2705 
   2706 /*
   2707  * Return the IP6 multicast options in response to user getsockopt().
   2708  */
   2709 static int
   2710 ip6_getmoptions(struct sockopt *sopt, struct in6pcb *in6p)
   2711 {
   2712 	u_int optval;
   2713 	int error;
   2714 	struct ip6_moptions *im6o = in6p->in6p_moptions;
   2715 
   2716 	switch (sopt->sopt_name) {
   2717 	case IPV6_MULTICAST_IF:
   2718 		if (im6o == NULL || im6o->im6o_multicast_if_index == 0)
   2719 			optval = 0;
   2720 		else
   2721 			optval = im6o->im6o_multicast_if_index;
   2722 
   2723 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2724 		break;
   2725 
   2726 	case IPV6_MULTICAST_HOPS:
   2727 		if (im6o == NULL)
   2728 			optval = ip6_defmcasthlim;
   2729 		else
   2730 			optval = im6o->im6o_multicast_hlim;
   2731 
   2732 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2733 		break;
   2734 
   2735 	case IPV6_MULTICAST_LOOP:
   2736 		if (im6o == NULL)
   2737 			optval = IPV6_DEFAULT_MULTICAST_LOOP;
   2738 		else
   2739 			optval = im6o->im6o_multicast_loop;
   2740 
   2741 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2742 		break;
   2743 
   2744 	default:
   2745 		error = EOPNOTSUPP;
   2746 	}
   2747 
   2748 	return (error);
   2749 }
   2750 
   2751 /*
   2752  * Discard the IP6 multicast options.
   2753  */
   2754 void
   2755 ip6_freemoptions(struct ip6_moptions *im6o)
   2756 {
   2757 	struct in6_multi_mship *imm, *nimm;
   2758 
   2759 	if (im6o == NULL)
   2760 		return;
   2761 
   2762 	/* The owner of im6o (in6p) should be protected by solock */
   2763 	LIST_FOREACH_SAFE(imm, &im6o->im6o_memberships, i6mm_chain, nimm) {
   2764 		struct ifnet *ifp;
   2765 
   2766 		LIST_REMOVE(imm, i6mm_chain);
   2767 
   2768 		ifp = imm->i6mm_maddr->in6m_ifp;
   2769 		IFNET_LOCK(ifp);
   2770 		in6_leavegroup(imm);
   2771 		/* ifp should not leave thanks to solock */
   2772 		IFNET_UNLOCK(ifp);
   2773 	}
   2774 	free(im6o, M_IPMOPTS);
   2775 }
   2776 
   2777 /*
   2778  * Set IPv6 outgoing packet options based on advanced API.
   2779  */
   2780 int
   2781 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
   2782 	struct ip6_pktopts *stickyopt, kauth_cred_t cred, int uproto)
   2783 {
   2784 	struct cmsghdr *cm = 0;
   2785 
   2786 	if (control == NULL || opt == NULL)
   2787 		return (EINVAL);
   2788 
   2789 	ip6_initpktopts(opt);
   2790 	if (stickyopt) {
   2791 		int error;
   2792 
   2793 		/*
   2794 		 * If stickyopt is provided, make a local copy of the options
   2795 		 * for this particular packet, then override them by ancillary
   2796 		 * objects.
   2797 		 * XXX: copypktopts() does not copy the cached route to a next
   2798 		 * hop (if any).  This is not very good in terms of efficiency,
   2799 		 * but we can allow this since this option should be rarely
   2800 		 * used.
   2801 		 */
   2802 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
   2803 			return (error);
   2804 	}
   2805 
   2806 	/*
   2807 	 * XXX: Currently, we assume all the optional information is stored
   2808 	 * in a single mbuf.
   2809 	 */
   2810 	if (control->m_next)
   2811 		return (EINVAL);
   2812 
   2813 	/* XXX if cm->cmsg_len is not aligned, control->m_len can become <0 */
   2814 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
   2815 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
   2816 		int error;
   2817 
   2818 		if (control->m_len < CMSG_LEN(0))
   2819 			return (EINVAL);
   2820 
   2821 		cm = mtod(control, struct cmsghdr *);
   2822 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
   2823 			return (EINVAL);
   2824 		if (cm->cmsg_level != IPPROTO_IPV6)
   2825 			continue;
   2826 
   2827 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
   2828 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
   2829 		if (error)
   2830 			return (error);
   2831 	}
   2832 
   2833 	return (0);
   2834 }
   2835 
   2836 /*
   2837  * Set a particular packet option, as a sticky option or an ancillary data
   2838  * item.  "len" can be 0 only when it's a sticky option.
   2839  * We have 4 cases of combination of "sticky" and "cmsg":
   2840  * "sticky=0, cmsg=0": impossible
   2841  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
   2842  * "sticky=1, cmsg=0": RFC3542 socket option
   2843  * "sticky=1, cmsg=1": RFC2292 socket option
   2844  */
   2845 static int
   2846 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
   2847     kauth_cred_t cred, int sticky, int cmsg, int uproto)
   2848 {
   2849 	int minmtupolicy;
   2850 	int error;
   2851 
   2852 	if (!sticky && !cmsg) {
   2853 #ifdef DIAGNOSTIC
   2854 		printf("ip6_setpktopt: impossible case\n");
   2855 #endif
   2856 		return (EINVAL);
   2857 	}
   2858 
   2859 	/*
   2860 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
   2861 	 * not be specified in the context of RFC3542.  Conversely,
   2862 	 * RFC3542 types should not be specified in the context of RFC2292.
   2863 	 */
   2864 	if (!cmsg) {
   2865 		switch (optname) {
   2866 		case IPV6_2292PKTINFO:
   2867 		case IPV6_2292HOPLIMIT:
   2868 		case IPV6_2292NEXTHOP:
   2869 		case IPV6_2292HOPOPTS:
   2870 		case IPV6_2292DSTOPTS:
   2871 		case IPV6_2292RTHDR:
   2872 		case IPV6_2292PKTOPTIONS:
   2873 			return (ENOPROTOOPT);
   2874 		}
   2875 	}
   2876 	if (sticky && cmsg) {
   2877 		switch (optname) {
   2878 		case IPV6_PKTINFO:
   2879 		case IPV6_HOPLIMIT:
   2880 		case IPV6_NEXTHOP:
   2881 		case IPV6_HOPOPTS:
   2882 		case IPV6_DSTOPTS:
   2883 		case IPV6_RTHDRDSTOPTS:
   2884 		case IPV6_RTHDR:
   2885 		case IPV6_USE_MIN_MTU:
   2886 		case IPV6_DONTFRAG:
   2887 		case IPV6_OTCLASS:
   2888 		case IPV6_TCLASS:
   2889 		case IPV6_PREFER_TEMPADDR: /* XXX not an RFC3542 option */
   2890 			return (ENOPROTOOPT);
   2891 		}
   2892 	}
   2893 
   2894 	switch (optname) {
   2895 #ifdef RFC2292
   2896 	case IPV6_2292PKTINFO:
   2897 #endif
   2898 	case IPV6_PKTINFO:
   2899 	{
   2900 		struct in6_pktinfo *pktinfo;
   2901 
   2902 		if (len != sizeof(struct in6_pktinfo))
   2903 			return (EINVAL);
   2904 
   2905 		pktinfo = (struct in6_pktinfo *)buf;
   2906 
   2907 		/*
   2908 		 * An application can clear any sticky IPV6_PKTINFO option by
   2909 		 * doing a "regular" setsockopt with ipi6_addr being
   2910 		 * in6addr_any and ipi6_ifindex being zero.
   2911 		 * [RFC 3542, Section 6]
   2912 		 */
   2913 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
   2914 		    pktinfo->ipi6_ifindex == 0 &&
   2915 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2916 			ip6_clearpktopts(opt, optname);
   2917 			break;
   2918 		}
   2919 
   2920 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
   2921 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2922 			return (EINVAL);
   2923 		}
   2924 
   2925 		/* Validate the interface index if specified. */
   2926 		if (pktinfo->ipi6_ifindex) {
   2927 			struct ifnet *ifp;
   2928 			int s = pserialize_read_enter();
   2929 			ifp = if_byindex(pktinfo->ipi6_ifindex);
   2930 			if (ifp == NULL) {
   2931 				pserialize_read_exit(s);
   2932 				return ENXIO;
   2933 			}
   2934 			pserialize_read_exit(s);
   2935 		}
   2936 
   2937 		/*
   2938 		 * We store the address anyway, and let in6_selectsrc()
   2939 		 * validate the specified address.  This is because ipi6_addr
   2940 		 * may not have enough information about its scope zone, and
   2941 		 * we may need additional information (such as outgoing
   2942 		 * interface or the scope zone of a destination address) to
   2943 		 * disambiguate the scope.
   2944 		 * XXX: the delay of the validation may confuse the
   2945 		 * application when it is used as a sticky option.
   2946 		 */
   2947 		if (opt->ip6po_pktinfo == NULL) {
   2948 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
   2949 			    M_IP6OPT, M_NOWAIT);
   2950 			if (opt->ip6po_pktinfo == NULL)
   2951 				return (ENOBUFS);
   2952 		}
   2953 		memcpy(opt->ip6po_pktinfo, pktinfo, sizeof(*pktinfo));
   2954 		break;
   2955 	}
   2956 
   2957 #ifdef RFC2292
   2958 	case IPV6_2292HOPLIMIT:
   2959 #endif
   2960 	case IPV6_HOPLIMIT:
   2961 	{
   2962 		int *hlimp;
   2963 
   2964 		/*
   2965 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
   2966 		 * to simplify the ordering among hoplimit options.
   2967 		 */
   2968 		if (optname == IPV6_HOPLIMIT && sticky)
   2969 			return (ENOPROTOOPT);
   2970 
   2971 		if (len != sizeof(int))
   2972 			return (EINVAL);
   2973 		hlimp = (int *)buf;
   2974 		if (*hlimp < -1 || *hlimp > 255)
   2975 			return (EINVAL);
   2976 
   2977 		opt->ip6po_hlim = *hlimp;
   2978 		break;
   2979 	}
   2980 
   2981 	case IPV6_OTCLASS:
   2982 		if (len != sizeof(u_int8_t))
   2983 			return (EINVAL);
   2984 
   2985 		opt->ip6po_tclass = *(u_int8_t *)buf;
   2986 		break;
   2987 
   2988 	case IPV6_TCLASS:
   2989 	{
   2990 		int tclass;
   2991 
   2992 		if (len != sizeof(int))
   2993 			return (EINVAL);
   2994 		tclass = *(int *)buf;
   2995 		if (tclass < -1 || tclass > 255)
   2996 			return (EINVAL);
   2997 
   2998 		opt->ip6po_tclass = tclass;
   2999 		break;
   3000 	}
   3001 
   3002 #ifdef RFC2292
   3003 	case IPV6_2292NEXTHOP:
   3004 #endif
   3005 	case IPV6_NEXTHOP:
   3006 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3007 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3008 		if (error)
   3009 			return (error);
   3010 
   3011 		if (len == 0) {	/* just remove the option */
   3012 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3013 			break;
   3014 		}
   3015 
   3016 		/* check if cmsg_len is large enough for sa_len */
   3017 		if (len < sizeof(struct sockaddr) || len < *buf)
   3018 			return (EINVAL);
   3019 
   3020 		switch (((struct sockaddr *)buf)->sa_family) {
   3021 		case AF_INET6:
   3022 		{
   3023 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
   3024 
   3025 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
   3026 				return (EINVAL);
   3027 
   3028 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
   3029 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
   3030 				return (EINVAL);
   3031 			}
   3032 			if ((error = sa6_embedscope(sa6, ip6_use_defzone))
   3033 			    != 0) {
   3034 				return (error);
   3035 			}
   3036 			break;
   3037 		}
   3038 		case AF_LINK:	/* eventually be supported? */
   3039 		default:
   3040 			return (EAFNOSUPPORT);
   3041 		}
   3042 
   3043 		/* turn off the previous option, then set the new option. */
   3044 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3045 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
   3046 		if (opt->ip6po_nexthop == NULL)
   3047 			return (ENOBUFS);
   3048 		memcpy(opt->ip6po_nexthop, buf, *buf);
   3049 		break;
   3050 
   3051 #ifdef RFC2292
   3052 	case IPV6_2292HOPOPTS:
   3053 #endif
   3054 	case IPV6_HOPOPTS:
   3055 	{
   3056 		struct ip6_hbh *hbh;
   3057 		int hbhlen;
   3058 
   3059 		/*
   3060 		 * XXX: We don't allow a non-privileged user to set ANY HbH
   3061 		 * options, since per-option restriction has too much
   3062 		 * overhead.
   3063 		 */
   3064 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3065 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3066 		if (error)
   3067 			return (error);
   3068 
   3069 		if (len == 0) {
   3070 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3071 			break;	/* just remove the option */
   3072 		}
   3073 
   3074 		/* message length validation */
   3075 		if (len < sizeof(struct ip6_hbh))
   3076 			return (EINVAL);
   3077 		hbh = (struct ip6_hbh *)buf;
   3078 		hbhlen = (hbh->ip6h_len + 1) << 3;
   3079 		if (len != hbhlen)
   3080 			return (EINVAL);
   3081 
   3082 		/* turn off the previous option, then set the new option. */
   3083 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3084 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
   3085 		if (opt->ip6po_hbh == NULL)
   3086 			return (ENOBUFS);
   3087 		memcpy(opt->ip6po_hbh, hbh, hbhlen);
   3088 
   3089 		break;
   3090 	}
   3091 
   3092 #ifdef RFC2292
   3093 	case IPV6_2292DSTOPTS:
   3094 #endif
   3095 	case IPV6_DSTOPTS:
   3096 	case IPV6_RTHDRDSTOPTS:
   3097 	{
   3098 		struct ip6_dest *dest, **newdest = NULL;
   3099 		int destlen;
   3100 
   3101 		/* XXX: see the comment for IPV6_HOPOPTS */
   3102 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3103 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3104 		if (error)
   3105 			return (error);
   3106 
   3107 		if (len == 0) {
   3108 			ip6_clearpktopts(opt, optname);
   3109 			break;	/* just remove the option */
   3110 		}
   3111 
   3112 		/* message length validation */
   3113 		if (len < sizeof(struct ip6_dest))
   3114 			return (EINVAL);
   3115 		dest = (struct ip6_dest *)buf;
   3116 		destlen = (dest->ip6d_len + 1) << 3;
   3117 		if (len != destlen)
   3118 			return (EINVAL);
   3119 		/*
   3120 		 * Determine the position that the destination options header
   3121 		 * should be inserted; before or after the routing header.
   3122 		 */
   3123 		switch (optname) {
   3124 		case IPV6_2292DSTOPTS:
   3125 			/*
   3126 			 * The old advanced API is ambiguous on this point.
   3127 			 * Our approach is to determine the position based
   3128 			 * according to the existence of a routing header.
   3129 			 * Note, however, that this depends on the order of the
   3130 			 * extension headers in the ancillary data; the 1st
   3131 			 * part of the destination options header must appear
   3132 			 * before the routing header in the ancillary data,
   3133 			 * too.
   3134 			 * RFC3542 solved the ambiguity by introducing
   3135 			 * separate ancillary data or option types.
   3136 			 */
   3137 			if (opt->ip6po_rthdr == NULL)
   3138 				newdest = &opt->ip6po_dest1;
   3139 			else
   3140 				newdest = &opt->ip6po_dest2;
   3141 			break;
   3142 		case IPV6_RTHDRDSTOPTS:
   3143 			newdest = &opt->ip6po_dest1;
   3144 			break;
   3145 		case IPV6_DSTOPTS:
   3146 			newdest = &opt->ip6po_dest2;
   3147 			break;
   3148 		}
   3149 
   3150 		/* turn off the previous option, then set the new option. */
   3151 		ip6_clearpktopts(opt, optname);
   3152 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
   3153 		if (*newdest == NULL)
   3154 			return (ENOBUFS);
   3155 		memcpy(*newdest, dest, destlen);
   3156 
   3157 		break;
   3158 	}
   3159 
   3160 #ifdef RFC2292
   3161 	case IPV6_2292RTHDR:
   3162 #endif
   3163 	case IPV6_RTHDR:
   3164 	{
   3165 		struct ip6_rthdr *rth;
   3166 		int rthlen;
   3167 
   3168 		if (len == 0) {
   3169 			ip6_clearpktopts(opt, IPV6_RTHDR);
   3170 			break;	/* just remove the option */
   3171 		}
   3172 
   3173 		/* message length validation */
   3174 		if (len < sizeof(struct ip6_rthdr))
   3175 			return (EINVAL);
   3176 		rth = (struct ip6_rthdr *)buf;
   3177 		rthlen = (rth->ip6r_len + 1) << 3;
   3178 		if (len != rthlen)
   3179 			return (EINVAL);
   3180 		switch (rth->ip6r_type) {
   3181 		case IPV6_RTHDR_TYPE_0:
   3182 			/* Dropped, RFC5095. */
   3183 		default:
   3184 			return (EINVAL);	/* not supported */
   3185 		}
   3186 		/* turn off the previous option */
   3187 		ip6_clearpktopts(opt, IPV6_RTHDR);
   3188 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
   3189 		if (opt->ip6po_rthdr == NULL)
   3190 			return (ENOBUFS);
   3191 		memcpy(opt->ip6po_rthdr, rth, rthlen);
   3192 		break;
   3193 	}
   3194 
   3195 	case IPV6_USE_MIN_MTU:
   3196 		if (len != sizeof(int))
   3197 			return (EINVAL);
   3198 		minmtupolicy = *(int *)buf;
   3199 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
   3200 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
   3201 		    minmtupolicy != IP6PO_MINMTU_ALL) {
   3202 			return (EINVAL);
   3203 		}
   3204 		opt->ip6po_minmtu = minmtupolicy;
   3205 		break;
   3206 
   3207 	case IPV6_DONTFRAG:
   3208 		if (len != sizeof(int))
   3209 			return (EINVAL);
   3210 
   3211 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
   3212 			/*
   3213 			 * we ignore this option for TCP sockets.
   3214 			 * (RFC3542 leaves this case unspecified.)
   3215 			 */
   3216 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
   3217 		} else
   3218 			opt->ip6po_flags |= IP6PO_DONTFRAG;
   3219 		break;
   3220 
   3221 	case IPV6_PREFER_TEMPADDR:
   3222 	{
   3223 		int preftemp;
   3224 
   3225 		if (len != sizeof(int))
   3226 			return (EINVAL);
   3227 		preftemp = *(int *)buf;
   3228 		switch (preftemp) {
   3229 		case IP6PO_TEMPADDR_SYSTEM:
   3230 		case IP6PO_TEMPADDR_NOTPREFER:
   3231 		case IP6PO_TEMPADDR_PREFER:
   3232 			break;
   3233 		default:
   3234 			return (EINVAL);
   3235 		}
   3236 		opt->ip6po_prefer_tempaddr = preftemp;
   3237 		break;
   3238 	}
   3239 
   3240 	default:
   3241 		return (ENOPROTOOPT);
   3242 	} /* end of switch */
   3243 
   3244 	return (0);
   3245 }
   3246 
   3247 /*
   3248  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
   3249  * packet to the input queue of a specified interface.  Note that this
   3250  * calls the output routine of the loopback "driver", but with an interface
   3251  * pointer that might NOT be lo0ifp -- easier than replicating that code here.
   3252  */
   3253 void
   3254 ip6_mloopback(struct ifnet *ifp, struct mbuf *m,
   3255 	const struct sockaddr_in6 *dst)
   3256 {
   3257 	struct mbuf *copym;
   3258 	struct ip6_hdr *ip6;
   3259 
   3260 	copym = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
   3261 	if (copym == NULL)
   3262 		return;
   3263 
   3264 	/*
   3265 	 * Make sure to deep-copy IPv6 header portion in case the data
   3266 	 * is in an mbuf cluster, so that we can safely override the IPv6
   3267 	 * header portion later.
   3268 	 */
   3269 	if ((copym->m_flags & M_EXT) != 0 ||
   3270 	    copym->m_len < sizeof(struct ip6_hdr)) {
   3271 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
   3272 		if (copym == NULL)
   3273 			return;
   3274 	}
   3275 
   3276 #ifdef DIAGNOSTIC
   3277 	if (copym->m_len < sizeof(*ip6)) {
   3278 		m_freem(copym);
   3279 		return;
   3280 	}
   3281 #endif
   3282 
   3283 	ip6 = mtod(copym, struct ip6_hdr *);
   3284 	/*
   3285 	 * clear embedded scope identifiers if necessary.
   3286 	 * in6_clearscope will touch the addresses only when necessary.
   3287 	 */
   3288 	in6_clearscope(&ip6->ip6_src);
   3289 	in6_clearscope(&ip6->ip6_dst);
   3290 
   3291 	(void)looutput(ifp, copym, (const struct sockaddr *)dst, NULL);
   3292 }
   3293 
   3294 /*
   3295  * Chop IPv6 header off from the payload.
   3296  */
   3297 static int
   3298 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
   3299 {
   3300 	struct mbuf *mh;
   3301 	struct ip6_hdr *ip6;
   3302 
   3303 	ip6 = mtod(m, struct ip6_hdr *);
   3304 	if (m->m_len > sizeof(*ip6)) {
   3305 		MGETHDR(mh, M_DONTWAIT, MT_HEADER);
   3306 		if (mh == NULL) {
   3307 			m_freem(m);
   3308 			return ENOBUFS;
   3309 		}
   3310 		M_MOVE_PKTHDR(mh, m);
   3311 		MH_ALIGN(mh, sizeof(*ip6));
   3312 		m->m_len -= sizeof(*ip6);
   3313 		m->m_data += sizeof(*ip6);
   3314 		mh->m_next = m;
   3315 		mh->m_len = sizeof(*ip6);
   3316 		memcpy(mtod(mh, void *), (void *)ip6, sizeof(*ip6));
   3317 		m = mh;
   3318 	}
   3319 	exthdrs->ip6e_ip6 = m;
   3320 	return 0;
   3321 }
   3322 
   3323 /*
   3324  * Compute IPv6 extension header length.
   3325  */
   3326 int
   3327 ip6_optlen(struct in6pcb *in6p)
   3328 {
   3329 	int len;
   3330 
   3331 	if (!in6p->in6p_outputopts)
   3332 		return 0;
   3333 
   3334 	len = 0;
   3335 #define elen(x) \
   3336     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
   3337 
   3338 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
   3339 	len += elen(in6p->in6p_outputopts->ip6po_dest1);
   3340 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
   3341 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
   3342 	return len;
   3343 #undef elen
   3344 }
   3345 
   3346 /*
   3347  * Ensure sending address is valid.
   3348  * Returns 0 on success, -1 if an error should be sent back or 1
   3349  * if the packet could be dropped without error (protocol dependent).
   3350  */
   3351 static int
   3352 ip6_ifaddrvalid(const struct in6_addr *src, const struct in6_addr *dst)
   3353 {
   3354 	struct sockaddr_in6 sin6;
   3355 	int s, error;
   3356 	struct ifaddr *ifa;
   3357 	struct in6_ifaddr *ia6;
   3358 
   3359 	if (IN6_IS_ADDR_UNSPECIFIED(src))
   3360 		return 0;
   3361 
   3362 	memset(&sin6, 0, sizeof(sin6));
   3363 	sin6.sin6_family = AF_INET6;
   3364 	sin6.sin6_len = sizeof(sin6);
   3365 	sin6.sin6_addr = *src;
   3366 
   3367 	s = pserialize_read_enter();
   3368 	ifa = ifa_ifwithaddr(sin6tosa(&sin6));
   3369 	if ((ia6 = ifatoia6(ifa)) == NULL ||
   3370 	    ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_DUPLICATED))
   3371 		error = -1;
   3372 	else if (ia6->ia6_flags & IN6_IFF_TENTATIVE)
   3373 		error = 1;
   3374 	else if (ia6->ia6_flags & IN6_IFF_DETACHED &&
   3375 	    (sin6.sin6_addr = *dst, ifa_ifwithaddr(sin6tosa(&sin6)) == NULL))
   3376 		/* Allow internal traffic to DETACHED addresses */
   3377 		error = 1;
   3378 	else
   3379 		error = 0;
   3380 	pserialize_read_exit(s);
   3381 
   3382 	return error;
   3383 }
   3384