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ip6_output.c revision 1.204
      1 /*	$NetBSD: ip6_output.c,v 1.204 2018/04/18 07:17:49 maxv 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 1.204 2018/04/18 07:17:49 maxv 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 
    110 #include <net/net_osdep.h>
    111 
    112 extern pfil_head_t *inet6_pfil_hook;	/* XXX */
    113 
    114 struct ip6_exthdrs {
    115 	struct mbuf *ip6e_ip6;
    116 	struct mbuf *ip6e_hbh;
    117 	struct mbuf *ip6e_dest1;
    118 	struct mbuf *ip6e_rthdr;
    119 	struct mbuf *ip6e_dest2;
    120 };
    121 
    122 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
    123 	kauth_cred_t, int);
    124 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
    125 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *, kauth_cred_t,
    126 	int, int, int);
    127 static int ip6_setmoptions(const struct sockopt *, struct in6pcb *);
    128 static int ip6_getmoptions(struct sockopt *, struct in6pcb *);
    129 static int ip6_copyexthdr(struct mbuf **, void *, int);
    130 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
    131 	struct ip6_frag **);
    132 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
    133 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
    134 static int ip6_getpmtu(struct rtentry *, struct ifnet *, u_long *, int *);
    135 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
    136 static int ip6_ifaddrvalid(const struct in6_addr *, const struct in6_addr *);
    137 static int ip6_handle_rthdr(struct ip6_rthdr *, struct ip6_hdr *);
    138 
    139 #ifdef RFC2292
    140 static int ip6_pcbopts(struct ip6_pktopts **, struct socket *, struct sockopt *);
    141 #endif
    142 
    143 static int
    144 ip6_handle_rthdr(struct ip6_rthdr *rh, struct ip6_hdr *ip6)
    145 {
    146 	struct ip6_rthdr0 *rh0;
    147 	struct in6_addr *addr;
    148 	struct sockaddr_in6 sa;
    149 	int error = 0;
    150 
    151 	switch (rh->ip6r_type) {
    152 	case IPV6_RTHDR_TYPE_0:
    153 		rh0 = (struct ip6_rthdr0 *)rh;
    154 		addr = (struct in6_addr *)(rh0 + 1);
    155 
    156 		/*
    157 		 * construct a sockaddr_in6 form of the first hop.
    158 		 *
    159 		 * XXX we may not have enough information about its scope zone;
    160 		 * there is no standard API to pass the information from the
    161 		 * application.
    162 		 */
    163 		sockaddr_in6_init(&sa, addr, 0, 0, 0);
    164 		error = sa6_embedscope(&sa, ip6_use_defzone);
    165 		if (error != 0)
    166 			break;
    167 		memmove(&addr[0], &addr[1],
    168 		    sizeof(struct in6_addr) * (rh0->ip6r0_segleft - 1));
    169 		addr[rh0->ip6r0_segleft - 1] = ip6->ip6_dst;
    170 		ip6->ip6_dst = sa.sin6_addr;
    171 		/* XXX */
    172 		in6_clearscope(addr + rh0->ip6r0_segleft - 1);
    173 		break;
    174 	default:	/* is it possible? */
    175 		error = EINVAL;
    176 	}
    177 
    178 	return error;
    179 }
    180 
    181 /*
    182  * Send an IP packet to a host.
    183  */
    184 int
    185 ip6_if_output(struct ifnet * const ifp, struct ifnet * const origifp,
    186     struct mbuf * const m, const struct sockaddr_in6 * const dst,
    187     const struct rtentry *rt)
    188 {
    189 	int error = 0;
    190 
    191 	if (rt != NULL) {
    192 		error = rt_check_reject_route(rt, ifp);
    193 		if (error != 0) {
    194 			m_freem(m);
    195 			return error;
    196 		}
    197 	}
    198 
    199 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
    200 		error = if_output_lock(ifp, origifp, m, sin6tocsa(dst), rt);
    201 	else
    202 		error = if_output_lock(ifp, ifp, m, sin6tocsa(dst), rt);
    203 	return error;
    204 }
    205 
    206 /*
    207  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
    208  * header (with pri, len, nxt, hlim, src, dst).
    209  *
    210  * This function may modify ver and hlim only. The mbuf chain containing the
    211  * packet will be freed. The mbuf opt, if present, will not be freed.
    212  *
    213  * Type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
    214  * nd_ifinfo.linkmtu is u_int32_t. So we use u_long to hold largest one,
    215  * which is rt_rmx.rmx_mtu.
    216  */
    217 int
    218 ip6_output(
    219     struct mbuf *m0,
    220     struct ip6_pktopts *opt,
    221     struct route *ro,
    222     int flags,
    223     struct ip6_moptions *im6o,
    224     struct in6pcb *in6p,
    225     struct ifnet **ifpp		/* XXX: just for statistics */
    226 )
    227 {
    228 	struct ip6_hdr *ip6, *mhip6;
    229 	struct ifnet *ifp = NULL, *origifp = NULL;
    230 	struct mbuf *m = m0;
    231 	int tlen, len, off;
    232 	bool tso;
    233 	struct route ip6route;
    234 	struct rtentry *rt = NULL, *rt_pmtu;
    235 	const struct sockaddr_in6 *dst;
    236 	struct sockaddr_in6 src_sa, dst_sa;
    237 	int error = 0;
    238 	struct in6_ifaddr *ia = NULL;
    239 	u_long mtu;
    240 	int alwaysfrag, dontfrag;
    241 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
    242 	struct ip6_exthdrs exthdrs;
    243 	struct in6_addr finaldst, src0, dst0;
    244 	u_int32_t zone;
    245 	struct route *ro_pmtu = NULL;
    246 	int hdrsplit = 0;
    247 	int needipsec = 0;
    248 #ifdef IPSEC
    249 	struct secpolicy *sp = NULL;
    250 #endif
    251 	struct psref psref, psref_ia;
    252 	int bound = curlwp_bind();
    253 	bool release_psref_ia = false;
    254 
    255 #ifdef DIAGNOSTIC
    256 	if ((m->m_flags & M_PKTHDR) == 0)
    257 		panic("ip6_output: no HDR");
    258 	if ((m->m_pkthdr.csum_flags &
    259 	    (M_CSUM_TCPv4|M_CSUM_UDPv4|M_CSUM_TSOv4)) != 0) {
    260 		panic("ip6_output: IPv4 checksum offload flags: %d",
    261 		    m->m_pkthdr.csum_flags);
    262 	}
    263 	if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) ==
    264 	    (M_CSUM_TCPv6|M_CSUM_UDPv6)) {
    265 		panic("ip6_output: conflicting checksum offload flags: %d",
    266 		    m->m_pkthdr.csum_flags);
    267 	}
    268 #endif
    269 
    270 	M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data, sizeof(struct ip6_hdr));
    271 
    272 #define MAKE_EXTHDR(hp, mp)						\
    273     do {								\
    274 	if (hp) {							\
    275 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
    276 		error = ip6_copyexthdr((mp), (void *)(hp), 		\
    277 		    ((eh)->ip6e_len + 1) << 3);				\
    278 		if (error)						\
    279 			goto freehdrs;					\
    280 	}								\
    281     } while (/*CONSTCOND*/ 0)
    282 
    283 	memset(&exthdrs, 0, sizeof(exthdrs));
    284 	if (opt) {
    285 		/* Hop-by-Hop options header */
    286 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
    287 		/* Destination options header (1st part) */
    288 		MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
    289 		/* Routing header */
    290 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
    291 		/* Destination options header (2nd part) */
    292 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
    293 	}
    294 
    295 	/*
    296 	 * Calculate the total length of the extension header chain.
    297 	 * Keep the length of the unfragmentable part for fragmentation.
    298 	 */
    299 	optlen = 0;
    300 	if (exthdrs.ip6e_hbh)
    301 		optlen += exthdrs.ip6e_hbh->m_len;
    302 	if (exthdrs.ip6e_dest1)
    303 		optlen += exthdrs.ip6e_dest1->m_len;
    304 	if (exthdrs.ip6e_rthdr)
    305 		optlen += exthdrs.ip6e_rthdr->m_len;
    306 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
    307 	/* NOTE: we don't add AH/ESP length here. do that later. */
    308 	if (exthdrs.ip6e_dest2)
    309 		optlen += exthdrs.ip6e_dest2->m_len;
    310 
    311 #ifdef IPSEC
    312 	if (ipsec_used) {
    313 		/* Check the security policy (SP) for the packet */
    314 		sp = ipsec6_check_policy(m, in6p, flags, &needipsec, &error);
    315 		if (error != 0) {
    316 			/*
    317 			 * Hack: -EINVAL is used to signal that a packet
    318 			 * should be silently discarded.  This is typically
    319 			 * because we asked key management for an SA and
    320 			 * it was delayed (e.g. kicked up to IKE).
    321 			 */
    322 			if (error == -EINVAL)
    323 				error = 0;
    324 			goto freehdrs;
    325 		}
    326 	}
    327 #endif
    328 
    329 	if (needipsec &&
    330 	    (m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    331 		in6_delayed_cksum(m);
    332 		m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    333 	}
    334 
    335 	/*
    336 	 * If we need IPsec, or there is at least one extension header,
    337 	 * separate IP6 header from the payload.
    338 	 */
    339 	if ((needipsec || optlen) && !hdrsplit) {
    340 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    341 			m = NULL;
    342 			goto freehdrs;
    343 		}
    344 		m = exthdrs.ip6e_ip6;
    345 		hdrsplit++;
    346 	}
    347 
    348 	/* adjust pointer */
    349 	ip6 = mtod(m, struct ip6_hdr *);
    350 
    351 	/* adjust mbuf packet header length */
    352 	m->m_pkthdr.len += optlen;
    353 	plen = m->m_pkthdr.len - sizeof(*ip6);
    354 
    355 	/* If this is a jumbo payload, insert a jumbo payload option. */
    356 	if (plen > IPV6_MAXPACKET) {
    357 		if (!hdrsplit) {
    358 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    359 				m = NULL;
    360 				goto freehdrs;
    361 			}
    362 			m = exthdrs.ip6e_ip6;
    363 			hdrsplit++;
    364 		}
    365 		/* adjust pointer */
    366 		ip6 = mtod(m, struct ip6_hdr *);
    367 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
    368 			goto freehdrs;
    369 		optlen += 8; /* XXX JUMBOOPTLEN */
    370 		ip6->ip6_plen = 0;
    371 	} else
    372 		ip6->ip6_plen = htons(plen);
    373 
    374 	/*
    375 	 * Concatenate headers and fill in next header fields.
    376 	 * Here we have, on "m"
    377 	 *	IPv6 payload
    378 	 * and we insert headers accordingly.  Finally, we should be getting:
    379 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
    380 	 *
    381 	 * during the header composing process, "m" points to IPv6 header.
    382 	 * "mprev" points to an extension header prior to esp.
    383 	 */
    384 	{
    385 		u_char *nexthdrp = &ip6->ip6_nxt;
    386 		struct mbuf *mprev = m;
    387 
    388 		/*
    389 		 * we treat dest2 specially.  this makes IPsec processing
    390 		 * much easier.  the goal here is to make mprev point the
    391 		 * mbuf prior to dest2.
    392 		 *
    393 		 * result: IPv6 dest2 payload
    394 		 * m and mprev will point to IPv6 header.
    395 		 */
    396 		if (exthdrs.ip6e_dest2) {
    397 			if (!hdrsplit)
    398 				panic("assumption failed: hdr not split");
    399 			exthdrs.ip6e_dest2->m_next = m->m_next;
    400 			m->m_next = exthdrs.ip6e_dest2;
    401 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
    402 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
    403 		}
    404 
    405 #define MAKE_CHAIN(m, mp, p, i)\
    406     do {\
    407 	if (m) {\
    408 		if (!hdrsplit) \
    409 			panic("assumption failed: hdr not split"); \
    410 		*mtod((m), u_char *) = *(p);\
    411 		*(p) = (i);\
    412 		p = mtod((m), u_char *);\
    413 		(m)->m_next = (mp)->m_next;\
    414 		(mp)->m_next = (m);\
    415 		(mp) = (m);\
    416 	}\
    417     } while (/*CONSTCOND*/ 0)
    418 		/*
    419 		 * result: IPv6 hbh dest1 rthdr dest2 payload
    420 		 * m will point to IPv6 header.  mprev will point to the
    421 		 * extension header prior to dest2 (rthdr in the above case).
    422 		 */
    423 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
    424 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
    425 		    IPPROTO_DSTOPTS);
    426 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
    427 		    IPPROTO_ROUTING);
    428 
    429 		M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data,
    430 		    sizeof(struct ip6_hdr) + optlen);
    431 	}
    432 
    433 	/* Need to save for pmtu */
    434 	finaldst = ip6->ip6_dst;
    435 
    436 	/*
    437 	 * If there is a routing header, replace destination address field
    438 	 * with the first hop of the routing header.
    439 	 */
    440 	if (exthdrs.ip6e_rthdr) {
    441 		struct ip6_rthdr *rh;
    442 
    443 		rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
    444 
    445 		error = ip6_handle_rthdr(rh, ip6);
    446 		if (error != 0)
    447 			goto bad;
    448 	}
    449 
    450 	/* Source address validation */
    451 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
    452 	    (flags & IPV6_UNSPECSRC) == 0) {
    453 		error = EOPNOTSUPP;
    454 		IP6_STATINC(IP6_STAT_BADSCOPE);
    455 		goto bad;
    456 	}
    457 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
    458 		error = EOPNOTSUPP;
    459 		IP6_STATINC(IP6_STAT_BADSCOPE);
    460 		goto bad;
    461 	}
    462 
    463 	IP6_STATINC(IP6_STAT_LOCALOUT);
    464 
    465 	/*
    466 	 * Route packet.
    467 	 */
    468 	/* initialize cached route */
    469 	if (ro == NULL) {
    470 		memset(&ip6route, 0, sizeof(ip6route));
    471 		ro = &ip6route;
    472 	}
    473 	ro_pmtu = ro;
    474 	if (opt && opt->ip6po_rthdr)
    475 		ro = &opt->ip6po_route;
    476 
    477 	/*
    478 	 * if specified, try to fill in the traffic class field.
    479 	 * do not override if a non-zero value is already set.
    480 	 * we check the diffserv field and the ecn field separately.
    481 	 */
    482 	if (opt && opt->ip6po_tclass >= 0) {
    483 		int mask = 0;
    484 
    485 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
    486 			mask |= 0xfc;
    487 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
    488 			mask |= 0x03;
    489 		if (mask != 0)
    490 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
    491 	}
    492 
    493 	/* fill in or override the hop limit field, if necessary. */
    494 	if (opt && opt->ip6po_hlim != -1)
    495 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
    496 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    497 		if (im6o != NULL)
    498 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
    499 		else
    500 			ip6->ip6_hlim = ip6_defmcasthlim;
    501 	}
    502 
    503 #ifdef IPSEC
    504 	if (needipsec) {
    505 		int s = splsoftnet();
    506 		error = ipsec6_process_packet(m, sp->req);
    507 		splx(s);
    508 
    509 		/*
    510 		 * Preserve KAME behaviour: ENOENT can be returned
    511 		 * when an SA acquire is in progress.  Don't propagate
    512 		 * this to user-level; it confuses applications.
    513 		 * XXX this will go away when the SADB is redone.
    514 		 */
    515 		if (error == ENOENT)
    516 			error = 0;
    517 
    518 		goto done;
    519 	}
    520 #endif
    521 
    522 	/* adjust pointer */
    523 	ip6 = mtod(m, struct ip6_hdr *);
    524 
    525 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    526 
    527 	/* We do not need a route for multicast */
    528 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    529 		struct in6_pktinfo *pi = NULL;
    530 
    531 		/*
    532 		 * If the outgoing interface for the address is specified by
    533 		 * the caller, use it.
    534 		 */
    535 		if (opt && (pi = opt->ip6po_pktinfo) != NULL) {
    536 			/* XXX boundary check is assumed to be already done. */
    537 			ifp = if_get_byindex(pi->ipi6_ifindex, &psref);
    538 		} else if (im6o != NULL) {
    539 			ifp = if_get_byindex(im6o->im6o_multicast_if_index,
    540 			    &psref);
    541 		}
    542 	}
    543 
    544 	if (ifp == NULL) {
    545 		error = in6_selectroute(&dst_sa, opt, &ro, &rt, true);
    546 		if (error != 0)
    547 			goto bad;
    548 		ifp = if_get_byindex(rt->rt_ifp->if_index, &psref);
    549 	}
    550 
    551 	if (rt == NULL) {
    552 		/*
    553 		 * If in6_selectroute() does not return a route entry,
    554 		 * dst may not have been updated.
    555 		 */
    556 		error = rtcache_setdst(ro, sin6tosa(&dst_sa));
    557 		if (error) {
    558 			goto bad;
    559 		}
    560 	}
    561 
    562 	/*
    563 	 * then rt (for unicast) and ifp must be non-NULL valid values.
    564 	 */
    565 	if ((flags & IPV6_FORWARDING) == 0) {
    566 		/* XXX: the FORWARDING flag can be set for mrouting. */
    567 		in6_ifstat_inc(ifp, ifs6_out_request);
    568 	}
    569 	if (rt != NULL) {
    570 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
    571 		rt->rt_use++;
    572 	}
    573 
    574 	/*
    575 	 * The outgoing interface must be in the zone of source and
    576 	 * destination addresses.  We should use ia_ifp to support the
    577 	 * case of sending packets to an address of our own.
    578 	 */
    579 	if (ia != NULL && ia->ia_ifp) {
    580 		origifp = ia->ia_ifp;
    581 		if (if_is_deactivated(origifp))
    582 			goto bad;
    583 		if_acquire(origifp, &psref_ia);
    584 		release_psref_ia = true;
    585 	} else
    586 		origifp = ifp;
    587 
    588 	src0 = ip6->ip6_src;
    589 	if (in6_setscope(&src0, origifp, &zone))
    590 		goto badscope;
    591 	sockaddr_in6_init(&src_sa, &ip6->ip6_src, 0, 0, 0);
    592 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
    593 		goto badscope;
    594 
    595 	dst0 = ip6->ip6_dst;
    596 	if (in6_setscope(&dst0, origifp, &zone))
    597 		goto badscope;
    598 	/* re-initialize to be sure */
    599 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    600 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id)
    601 		goto badscope;
    602 
    603 	/* scope check is done. */
    604 
    605 	/* Ensure we only send from a valid address. */
    606 	if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
    607 	    (error = ip6_ifaddrvalid(&src0, &dst0)) != 0)
    608 	{
    609 		char ip6buf[INET6_ADDRSTRLEN];
    610 		nd6log(LOG_ERR,
    611 		    "refusing to send from invalid address %s (pid %d)\n",
    612 		    IN6_PRINT(ip6buf, &src0), curproc->p_pid);
    613 		IP6_STATINC(IP6_STAT_ODROPPED);
    614 		in6_ifstat_inc(origifp, ifs6_out_discard);
    615 		if (error == 1)
    616 			/*
    617 			 * Address exists, but is tentative or detached.
    618 			 * We can't send from it because it's invalid,
    619 			 * so we drop the packet.
    620 			 */
    621 			error = 0;
    622 		else
    623 			error = EADDRNOTAVAIL;
    624 		goto bad;
    625 	}
    626 
    627 	if (rt != NULL && (rt->rt_flags & RTF_GATEWAY) &&
    628 	    !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
    629 		dst = satocsin6(rt->rt_gateway);
    630 	else
    631 		dst = satocsin6(rtcache_getdst(ro));
    632 
    633 	/*
    634 	 * XXXXXX: original code follows:
    635 	 */
    636 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
    637 		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
    638 	else {
    639 		bool ingroup;
    640 
    641 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
    642 
    643 		in6_ifstat_inc(ifp, ifs6_out_mcast);
    644 
    645 		/*
    646 		 * Confirm that the outgoing interface supports multicast.
    647 		 */
    648 		if (!(ifp->if_flags & IFF_MULTICAST)) {
    649 			IP6_STATINC(IP6_STAT_NOROUTE);
    650 			in6_ifstat_inc(ifp, ifs6_out_discard);
    651 			error = ENETUNREACH;
    652 			goto bad;
    653 		}
    654 
    655 		ingroup = in6_multi_group(&ip6->ip6_dst, ifp);
    656 		if (ingroup && (im6o == NULL || im6o->im6o_multicast_loop)) {
    657 			/*
    658 			 * If we belong to the destination multicast group
    659 			 * on the outgoing interface, and the caller did not
    660 			 * forbid loopback, loop back a copy.
    661 			 */
    662 			KASSERT(dst != NULL);
    663 			ip6_mloopback(ifp, m, dst);
    664 		} else {
    665 			/*
    666 			 * If we are acting as a multicast router, perform
    667 			 * multicast forwarding as if the packet had just
    668 			 * arrived on the interface to which we are about
    669 			 * to send.  The multicast forwarding function
    670 			 * recursively calls this function, using the
    671 			 * IPV6_FORWARDING flag to prevent infinite recursion.
    672 			 *
    673 			 * Multicasts that are looped back by ip6_mloopback(),
    674 			 * above, will be forwarded by the ip6_input() routine,
    675 			 * if necessary.
    676 			 */
    677 			if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
    678 				if (ip6_mforward(ip6, ifp, m) != 0) {
    679 					m_freem(m);
    680 					goto done;
    681 				}
    682 			}
    683 		}
    684 		/*
    685 		 * Multicasts with a hoplimit of zero may be looped back,
    686 		 * above, but must not be transmitted on a network.
    687 		 * Also, multicasts addressed to the loopback interface
    688 		 * are not sent -- the above call to ip6_mloopback() will
    689 		 * loop back a copy if this host actually belongs to the
    690 		 * destination group on the loopback interface.
    691 		 */
    692 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
    693 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
    694 			m_freem(m);
    695 			goto done;
    696 		}
    697 	}
    698 
    699 	/*
    700 	 * Fill the outgoing inteface to tell the upper layer
    701 	 * to increment per-interface statistics.
    702 	 */
    703 	if (ifpp)
    704 		*ifpp = ifp;
    705 
    706 	/* Determine path MTU. */
    707 	/*
    708 	 * ro_pmtu represent final destination while
    709 	 * ro might represent immediate destination.
    710 	 * Use ro_pmtu destination since MTU might differ.
    711 	 */
    712 	if (ro_pmtu != ro) {
    713 		union {
    714 			struct sockaddr		dst;
    715 			struct sockaddr_in6	dst6;
    716 		} u;
    717 
    718 		/* ro_pmtu may not have a cache */
    719 		sockaddr_in6_init(&u.dst6, &finaldst, 0, 0, 0);
    720 		rt_pmtu = rtcache_lookup(ro_pmtu, &u.dst);
    721 	} else
    722 		rt_pmtu = rt;
    723 	error = ip6_getpmtu(rt_pmtu, ifp, &mtu, &alwaysfrag);
    724 	if (rt_pmtu != NULL && rt_pmtu != rt)
    725 		rtcache_unref(rt_pmtu, ro_pmtu);
    726 	if (error != 0)
    727 		goto bad;
    728 
    729 	/*
    730 	 * The caller of this function may specify to use the minimum MTU
    731 	 * in some cases.
    732 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
    733 	 * setting.  The logic is a bit complicated; by default, unicast
    734 	 * packets will follow path MTU while multicast packets will be sent at
    735 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
    736 	 * including unicast ones will be sent at the minimum MTU.  Multicast
    737 	 * packets will always be sent at the minimum MTU unless
    738 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
    739 	 * See RFC 3542 for more details.
    740 	 */
    741 	if (mtu > IPV6_MMTU) {
    742 		if ((flags & IPV6_MINMTU))
    743 			mtu = IPV6_MMTU;
    744 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
    745 			mtu = IPV6_MMTU;
    746 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
    747 			 (opt == NULL ||
    748 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
    749 			mtu = IPV6_MMTU;
    750 		}
    751 	}
    752 
    753 	/*
    754 	 * clear embedded scope identifiers if necessary.
    755 	 * in6_clearscope will touch the addresses only when necessary.
    756 	 */
    757 	in6_clearscope(&ip6->ip6_src);
    758 	in6_clearscope(&ip6->ip6_dst);
    759 
    760 	/*
    761 	 * If the outgoing packet contains a hop-by-hop options header,
    762 	 * it must be examined and processed even by the source node.
    763 	 * (RFC 2460, section 4.)
    764 	 *
    765 	 * XXX Is this really necessary?
    766 	 */
    767 	if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
    768 		u_int32_t dummy1; /* XXX unused */
    769 		u_int32_t dummy2; /* XXX unused */
    770 		int hoff = sizeof(struct ip6_hdr);
    771 
    772 		if (ip6_hopopts_input(&dummy1, &dummy2, &m, &hoff)) {
    773 			/* m was already freed at this point */
    774 			error = EINVAL;
    775 			goto done;
    776 		}
    777 
    778 		ip6 = mtod(m, struct ip6_hdr *);
    779 	}
    780 
    781 	/*
    782 	 * Run through list of hooks for output packets.
    783 	 */
    784 	if ((error = pfil_run_hooks(inet6_pfil_hook, &m, ifp, PFIL_OUT)) != 0)
    785 		goto done;
    786 	if (m == NULL)
    787 		goto done;
    788 	ip6 = mtod(m, struct ip6_hdr *);
    789 
    790 	/*
    791 	 * Send the packet to the outgoing interface.
    792 	 * If necessary, do IPv6 fragmentation before sending.
    793 	 *
    794 	 * the logic here is rather complex:
    795 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
    796 	 * 1-a:	send as is if tlen <= path mtu
    797 	 * 1-b:	fragment if tlen > path mtu
    798 	 *
    799 	 * 2: if user asks us not to fragment (dontfrag == 1)
    800 	 * 2-a:	send as is if tlen <= interface mtu
    801 	 * 2-b:	error if tlen > interface mtu
    802 	 *
    803 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
    804 	 *	always fragment
    805 	 *
    806 	 * 4: if dontfrag == 1 && alwaysfrag == 1
    807 	 *	error, as we cannot handle this conflicting request
    808 	 */
    809 	tlen = m->m_pkthdr.len;
    810 	tso = (m->m_pkthdr.csum_flags & M_CSUM_TSOv6) != 0;
    811 	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
    812 		dontfrag = 1;
    813 	else
    814 		dontfrag = 0;
    815 
    816 	if (dontfrag && alwaysfrag) {	/* case 4 */
    817 		/* conflicting request - can't transmit */
    818 		error = EMSGSIZE;
    819 		goto bad;
    820 	}
    821 	if (dontfrag && (!tso && tlen > IN6_LINKMTU(ifp))) {	/* case 2-b */
    822 		/*
    823 		 * Even if the DONTFRAG option is specified, we cannot send the
    824 		 * packet when the data length is larger than the MTU of the
    825 		 * outgoing interface.
    826 		 * Notify the error by sending IPV6_PATHMTU ancillary data as
    827 		 * well as returning an error code (the latter is not described
    828 		 * in the API spec.)
    829 		 */
    830 		u_int32_t mtu32;
    831 		struct ip6ctlparam ip6cp;
    832 
    833 		mtu32 = (u_int32_t)mtu;
    834 		memset(&ip6cp, 0, sizeof(ip6cp));
    835 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
    836 		pfctlinput2(PRC_MSGSIZE,
    837 		    rtcache_getdst(ro_pmtu), &ip6cp);
    838 
    839 		error = EMSGSIZE;
    840 		goto bad;
    841 	}
    842 
    843 	/*
    844 	 * transmit packet without fragmentation
    845 	 */
    846 	if (dontfrag || (!alwaysfrag && (tlen <= mtu || tso))) {
    847 		/* case 1-a and 2-a */
    848 		struct in6_ifaddr *ia6;
    849 		int sw_csum;
    850 		int s;
    851 
    852 		ip6 = mtod(m, struct ip6_hdr *);
    853 		s = pserialize_read_enter();
    854 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
    855 		if (ia6) {
    856 			/* Record statistics for this interface address. */
    857 			ia6->ia_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len;
    858 		}
    859 		pserialize_read_exit(s);
    860 
    861 		sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx;
    862 		if ((sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    863 			if (IN6_NEED_CHECKSUM(ifp,
    864 			    sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
    865 				in6_delayed_cksum(m);
    866 			}
    867 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    868 		}
    869 
    870 		KASSERT(dst != NULL);
    871 		if (__predict_true(!tso ||
    872 		    (ifp->if_capenable & IFCAP_TSOv6) != 0)) {
    873 			error = ip6_if_output(ifp, origifp, m, dst, rt);
    874 		} else {
    875 			error = ip6_tso_output(ifp, origifp, m, dst, rt);
    876 		}
    877 		goto done;
    878 	}
    879 
    880 	if (tso) {
    881 		error = EINVAL; /* XXX */
    882 		goto bad;
    883 	}
    884 
    885 	/*
    886 	 * try to fragment the packet.  case 1-b and 3
    887 	 */
    888 	if (mtu < IPV6_MMTU) {
    889 		/* path MTU cannot be less than IPV6_MMTU */
    890 		error = EMSGSIZE;
    891 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
    892 		goto bad;
    893 	} else if (ip6->ip6_plen == 0) {
    894 		/* jumbo payload cannot be fragmented */
    895 		error = EMSGSIZE;
    896 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
    897 		goto bad;
    898 	} else {
    899 		const u_int32_t id = htonl(ip6_randomid());
    900 		struct mbuf **mnext, *m_frgpart;
    901 		const int hlen = unfragpartlen;
    902 		struct ip6_frag *ip6f;
    903 		u_char nextproto;
    904 #if 0		/* see below */
    905 		struct ip6ctlparam ip6cp;
    906 		u_int32_t mtu32;
    907 #endif
    908 
    909 		if (mtu > IPV6_MAXPACKET)
    910 			mtu = IPV6_MAXPACKET;
    911 
    912 #if 0
    913 		/*
    914 		 * It is believed this code is a leftover from the
    915 		 * development of the IPV6_RECVPATHMTU sockopt and
    916 		 * associated work to implement RFC3542.
    917 		 * It's not entirely clear what the intent of the API
    918 		 * is at this point, so disable this code for now.
    919 		 * The IPV6_RECVPATHMTU sockopt and/or IPV6_DONTFRAG
    920 		 * will send notifications if the application requests.
    921 		 */
    922 
    923 		/* Notify a proper path MTU to applications. */
    924 		mtu32 = (u_int32_t)mtu;
    925 		memset(&ip6cp, 0, sizeof(ip6cp));
    926 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
    927 		pfctlinput2(PRC_MSGSIZE,
    928 		    rtcache_getdst(ro_pmtu), &ip6cp);
    929 #endif
    930 
    931 		/*
    932 		 * Must be able to put at least 8 bytes per fragment.
    933 		 */
    934 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
    935 		if (len < 8) {
    936 			error = EMSGSIZE;
    937 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
    938 			goto bad;
    939 		}
    940 
    941 		mnext = &m->m_nextpkt;
    942 
    943 		/*
    944 		 * Change the next header field of the last header in the
    945 		 * unfragmentable part.
    946 		 */
    947 		if (exthdrs.ip6e_rthdr) {
    948 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
    949 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
    950 		} else if (exthdrs.ip6e_dest1) {
    951 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
    952 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
    953 		} else if (exthdrs.ip6e_hbh) {
    954 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
    955 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
    956 		} else {
    957 			nextproto = ip6->ip6_nxt;
    958 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
    959 		}
    960 
    961 		if ((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6))
    962 		    != 0) {
    963 			if (IN6_NEED_CHECKSUM(ifp,
    964 			    m->m_pkthdr.csum_flags &
    965 			    (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
    966 				in6_delayed_cksum(m);
    967 			}
    968 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    969 		}
    970 
    971 		/*
    972 		 * Loop through length of segment after first fragment,
    973 		 * make new header and copy data of each part and link onto
    974 		 * chain.
    975 		 */
    976 		m0 = m;
    977 		for (off = hlen; off < tlen; off += len) {
    978 			struct mbuf *mlast;
    979 
    980 			MGETHDR(m, M_DONTWAIT, MT_HEADER);
    981 			if (!m) {
    982 				error = ENOBUFS;
    983 				IP6_STATINC(IP6_STAT_ODROPPED);
    984 				goto sendorfree;
    985 			}
    986 			m_reset_rcvif(m);
    987 			m->m_flags = m0->m_flags & M_COPYFLAGS;
    988 			*mnext = m;
    989 			mnext = &m->m_nextpkt;
    990 			m->m_data += max_linkhdr;
    991 			mhip6 = mtod(m, struct ip6_hdr *);
    992 			*mhip6 = *ip6;
    993 			m->m_len = sizeof(*mhip6);
    994 
    995 			ip6f = NULL;
    996 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
    997 			if (error) {
    998 				IP6_STATINC(IP6_STAT_ODROPPED);
    999 				goto sendorfree;
   1000 			}
   1001 
   1002 			/* Fill in the Frag6 Header */
   1003 			ip6f->ip6f_offlg = htons((u_int16_t)((off - hlen) & ~7));
   1004 			if (off + len >= tlen)
   1005 				len = tlen - off;
   1006 			else
   1007 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
   1008 			ip6f->ip6f_reserved = 0;
   1009 			ip6f->ip6f_ident = id;
   1010 			ip6f->ip6f_nxt = nextproto;
   1011 
   1012 			mhip6->ip6_plen = htons((u_int16_t)(len + hlen +
   1013 			    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
   1014 			if ((m_frgpart = m_copy(m0, off, len)) == NULL) {
   1015 				error = ENOBUFS;
   1016 				IP6_STATINC(IP6_STAT_ODROPPED);
   1017 				goto sendorfree;
   1018 			}
   1019 			for (mlast = m; mlast->m_next; mlast = mlast->m_next)
   1020 				;
   1021 			mlast->m_next = m_frgpart;
   1022 
   1023 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
   1024 			m_reset_rcvif(m);
   1025 			IP6_STATINC(IP6_STAT_OFRAGMENTS);
   1026 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
   1027 		}
   1028 
   1029 		in6_ifstat_inc(ifp, ifs6_out_fragok);
   1030 	}
   1031 
   1032 sendorfree:
   1033 	m = m0->m_nextpkt;
   1034 	m0->m_nextpkt = 0;
   1035 	m_freem(m0);
   1036 	for (m0 = m; m; m = m0) {
   1037 		m0 = m->m_nextpkt;
   1038 		m->m_nextpkt = 0;
   1039 		if (error == 0) {
   1040 			struct in6_ifaddr *ia6;
   1041 			int s;
   1042 			ip6 = mtod(m, struct ip6_hdr *);
   1043 			s = pserialize_read_enter();
   1044 			ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
   1045 			if (ia6) {
   1046 				/*
   1047 				 * Record statistics for this interface
   1048 				 * address.
   1049 				 */
   1050 				ia6->ia_ifa.ifa_data.ifad_outbytes +=
   1051 				    m->m_pkthdr.len;
   1052 			}
   1053 			pserialize_read_exit(s);
   1054 			KASSERT(dst != NULL);
   1055 			error = ip6_if_output(ifp, origifp, m, dst, rt);
   1056 		} else
   1057 			m_freem(m);
   1058 	}
   1059 
   1060 	if (error == 0)
   1061 		IP6_STATINC(IP6_STAT_FRAGMENTED);
   1062 
   1063 done:
   1064 	rtcache_unref(rt, ro);
   1065 	if (ro == &ip6route)
   1066 		rtcache_free(&ip6route);
   1067 #ifdef IPSEC
   1068 	if (sp != NULL)
   1069 		KEY_SP_UNREF(&sp);
   1070 #endif
   1071 	if_put(ifp, &psref);
   1072 	if (release_psref_ia)
   1073 		if_put(origifp, &psref_ia);
   1074 	curlwp_bindx(bound);
   1075 
   1076 	return error;
   1077 
   1078 freehdrs:
   1079 	m_freem(exthdrs.ip6e_hbh);
   1080 	m_freem(exthdrs.ip6e_dest1);
   1081 	m_freem(exthdrs.ip6e_rthdr);
   1082 	m_freem(exthdrs.ip6e_dest2);
   1083 	/* FALLTHROUGH */
   1084 bad:
   1085 	m_freem(m);
   1086 	goto done;
   1087 
   1088 badscope:
   1089 	IP6_STATINC(IP6_STAT_BADSCOPE);
   1090 	in6_ifstat_inc(origifp, ifs6_out_discard);
   1091 	if (error == 0)
   1092 		error = EHOSTUNREACH; /* XXX */
   1093 	goto bad;
   1094 }
   1095 
   1096 static int
   1097 ip6_copyexthdr(struct mbuf **mp, void *hdr, int hlen)
   1098 {
   1099 	struct mbuf *m;
   1100 
   1101 	if (hlen > MCLBYTES)
   1102 		return ENOBUFS; /* XXX */
   1103 
   1104 	MGET(m, M_DONTWAIT, MT_DATA);
   1105 	if (!m)
   1106 		return ENOBUFS;
   1107 
   1108 	if (hlen > MLEN) {
   1109 		MCLGET(m, M_DONTWAIT);
   1110 		if ((m->m_flags & M_EXT) == 0) {
   1111 			m_free(m);
   1112 			return ENOBUFS;
   1113 		}
   1114 	}
   1115 	m->m_len = hlen;
   1116 	if (hdr)
   1117 		memcpy(mtod(m, void *), hdr, hlen);
   1118 
   1119 	*mp = m;
   1120 	return 0;
   1121 }
   1122 
   1123 /*
   1124  * Process a delayed payload checksum calculation.
   1125  */
   1126 void
   1127 in6_delayed_cksum(struct mbuf *m)
   1128 {
   1129 	uint16_t csum, offset;
   1130 
   1131 	KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1132 	KASSERT((~m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1133 	KASSERT((m->m_pkthdr.csum_flags
   1134 	    & (M_CSUM_UDPv4|M_CSUM_TCPv4|M_CSUM_TSOv4)) == 0);
   1135 
   1136 	offset = M_CSUM_DATA_IPv6_HL(m->m_pkthdr.csum_data);
   1137 	csum = in6_cksum(m, 0, offset, m->m_pkthdr.len - offset);
   1138 	if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv6) != 0) {
   1139 		csum = 0xffff;
   1140 	}
   1141 
   1142 	offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data);
   1143 	if ((offset + sizeof(csum)) > m->m_len) {
   1144 		m_copyback(m, offset, sizeof(csum), &csum);
   1145 	} else {
   1146 		*(uint16_t *)(mtod(m, char *) + offset) = csum;
   1147 	}
   1148 }
   1149 
   1150 /*
   1151  * Insert jumbo payload option.
   1152  */
   1153 static int
   1154 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
   1155 {
   1156 	struct mbuf *mopt;
   1157 	u_int8_t *optbuf;
   1158 	u_int32_t v;
   1159 
   1160 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
   1161 
   1162 	/*
   1163 	 * If there is no hop-by-hop options header, allocate new one.
   1164 	 * If there is one but it doesn't have enough space to store the
   1165 	 * jumbo payload option, allocate a cluster to store the whole options.
   1166 	 * Otherwise, use it to store the options.
   1167 	 */
   1168 	if (exthdrs->ip6e_hbh == NULL) {
   1169 		MGET(mopt, M_DONTWAIT, MT_DATA);
   1170 		if (mopt == 0)
   1171 			return (ENOBUFS);
   1172 		mopt->m_len = JUMBOOPTLEN;
   1173 		optbuf = mtod(mopt, u_int8_t *);
   1174 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
   1175 		exthdrs->ip6e_hbh = mopt;
   1176 	} else {
   1177 		struct ip6_hbh *hbh;
   1178 
   1179 		mopt = exthdrs->ip6e_hbh;
   1180 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
   1181 			const int oldoptlen = mopt->m_len;
   1182 			struct mbuf *n;
   1183 
   1184 			/*
   1185 			 * Assumptions:
   1186 			 * - exthdrs->ip6e_hbh is not referenced from places
   1187 			 *   other than exthdrs.
   1188 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
   1189 			 */
   1190 			KASSERT(mopt->m_next == NULL);
   1191 
   1192 			/*
   1193 			 * Give up if the whole (new) hbh header does not fit
   1194 			 * even in an mbuf cluster.
   1195 			 */
   1196 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
   1197 				return ENOBUFS;
   1198 
   1199 			/*
   1200 			 * At this point, we must always prepare a cluster.
   1201 			 */
   1202 			MGET(n, M_DONTWAIT, MT_DATA);
   1203 			if (n) {
   1204 				MCLGET(n, M_DONTWAIT);
   1205 				if ((n->m_flags & M_EXT) == 0) {
   1206 					m_freem(n);
   1207 					n = NULL;
   1208 				}
   1209 			}
   1210 			if (!n)
   1211 				return ENOBUFS;
   1212 
   1213 			n->m_len = oldoptlen + JUMBOOPTLEN;
   1214 			bcopy(mtod(mopt, void *), mtod(n, void *),
   1215 			    oldoptlen);
   1216 			optbuf = mtod(n, u_int8_t *) + oldoptlen;
   1217 			m_freem(mopt);
   1218 			mopt = exthdrs->ip6e_hbh = n;
   1219 		} else {
   1220 			optbuf = mtod(mopt, u_int8_t *) + mopt->m_len;
   1221 			mopt->m_len += JUMBOOPTLEN;
   1222 		}
   1223 		optbuf[0] = IP6OPT_PADN;
   1224 		optbuf[1] = 0;
   1225 
   1226 		/*
   1227 		 * Adjust the header length according to the pad and
   1228 		 * the jumbo payload option.
   1229 		 */
   1230 		hbh = mtod(mopt, struct ip6_hbh *);
   1231 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
   1232 	}
   1233 
   1234 	/* fill in the option. */
   1235 	optbuf[2] = IP6OPT_JUMBO;
   1236 	optbuf[3] = 4;
   1237 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
   1238 	memcpy(&optbuf[4], &v, sizeof(u_int32_t));
   1239 
   1240 	/* finally, adjust the packet header length */
   1241 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
   1242 
   1243 	return 0;
   1244 #undef JUMBOOPTLEN
   1245 }
   1246 
   1247 /*
   1248  * Insert fragment header and copy unfragmentable header portions.
   1249  *
   1250  * *frghdrp will not be read, and it is guaranteed that either an
   1251  * error is returned or that *frghdrp will point to space allocated
   1252  * for the fragment header.
   1253  *
   1254  * On entry, m contains:
   1255  *     IPv6 Header
   1256  * On exit, it contains:
   1257  *     IPv6 Header -> Unfragmentable Part -> Frag6 Header
   1258  */
   1259 static int
   1260 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
   1261 	struct ip6_frag **frghdrp)
   1262 {
   1263 	struct mbuf *n, *mlast;
   1264 
   1265 	if (hlen > sizeof(struct ip6_hdr)) {
   1266 		n = m_copym(m0, sizeof(struct ip6_hdr),
   1267 		    hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
   1268 		if (n == NULL)
   1269 			return ENOBUFS;
   1270 		m->m_next = n;
   1271 	} else
   1272 		n = m;
   1273 
   1274 	/* Search for the last mbuf of unfragmentable part. */
   1275 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
   1276 		;
   1277 
   1278 	if ((mlast->m_flags & M_EXT) == 0 &&
   1279 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
   1280 		/* use the trailing space of the last mbuf for the fragment hdr */
   1281 		*frghdrp = (struct ip6_frag *)(mtod(mlast, char *) +
   1282 		    mlast->m_len);
   1283 		mlast->m_len += sizeof(struct ip6_frag);
   1284 	} else {
   1285 		/* allocate a new mbuf for the fragment header */
   1286 		struct mbuf *mfrg;
   1287 
   1288 		MGET(mfrg, M_DONTWAIT, MT_DATA);
   1289 		if (mfrg == NULL)
   1290 			return ENOBUFS;
   1291 		mfrg->m_len = sizeof(struct ip6_frag);
   1292 		*frghdrp = mtod(mfrg, struct ip6_frag *);
   1293 		mlast->m_next = mfrg;
   1294 	}
   1295 
   1296 	return 0;
   1297 }
   1298 
   1299 static int
   1300 ip6_getpmtu(struct rtentry *rt, struct ifnet *ifp, u_long *mtup,
   1301     int *alwaysfragp)
   1302 {
   1303 	u_int32_t mtu = 0;
   1304 	int alwaysfrag = 0;
   1305 	int error = 0;
   1306 
   1307 	if (rt != NULL) {
   1308 		u_int32_t ifmtu;
   1309 
   1310 		if (ifp == NULL)
   1311 			ifp = rt->rt_ifp;
   1312 		ifmtu = IN6_LINKMTU(ifp);
   1313 		mtu = rt->rt_rmx.rmx_mtu;
   1314 		if (mtu == 0)
   1315 			mtu = ifmtu;
   1316 		else if (mtu < IPV6_MMTU) {
   1317 			/*
   1318 			 * RFC2460 section 5, last paragraph:
   1319 			 * if we record ICMPv6 too big message with
   1320 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
   1321 			 * or smaller, with fragment header attached.
   1322 			 * (fragment header is needed regardless from the
   1323 			 * packet size, for translators to identify packets)
   1324 			 */
   1325 			alwaysfrag = 1;
   1326 			mtu = IPV6_MMTU;
   1327 		} else if (mtu > ifmtu) {
   1328 			/*
   1329 			 * The MTU on the route is larger than the MTU on
   1330 			 * the interface!  This shouldn't happen, unless the
   1331 			 * MTU of the interface has been changed after the
   1332 			 * interface was brought up.  Change the MTU in the
   1333 			 * route to match the interface MTU (as long as the
   1334 			 * field isn't locked).
   1335 			 */
   1336 			mtu = ifmtu;
   1337 			if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
   1338 				rt->rt_rmx.rmx_mtu = mtu;
   1339 		}
   1340 	} else if (ifp) {
   1341 		mtu = IN6_LINKMTU(ifp);
   1342 	} else
   1343 		error = EHOSTUNREACH; /* XXX */
   1344 
   1345 	*mtup = mtu;
   1346 	if (alwaysfragp)
   1347 		*alwaysfragp = alwaysfrag;
   1348 	return (error);
   1349 }
   1350 
   1351 /*
   1352  * IP6 socket option processing.
   1353  */
   1354 int
   1355 ip6_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   1356 {
   1357 	int optdatalen, uproto;
   1358 	void *optdata;
   1359 	struct in6pcb *in6p = sotoin6pcb(so);
   1360 	struct ip_moptions **mopts;
   1361 	int error, optval;
   1362 	int level, optname;
   1363 
   1364 	KASSERT(solocked(so));
   1365 	KASSERT(sopt != NULL);
   1366 
   1367 	level = sopt->sopt_level;
   1368 	optname = sopt->sopt_name;
   1369 
   1370 	error = optval = 0;
   1371 	uproto = (int)so->so_proto->pr_protocol;
   1372 
   1373 	switch (level) {
   1374 	case IPPROTO_IP:
   1375 		switch (optname) {
   1376 		case IP_ADD_MEMBERSHIP:
   1377 		case IP_DROP_MEMBERSHIP:
   1378 		case IP_MULTICAST_IF:
   1379 		case IP_MULTICAST_LOOP:
   1380 		case IP_MULTICAST_TTL:
   1381 			mopts = &in6p->in6p_v4moptions;
   1382 			switch (op) {
   1383 			case PRCO_GETOPT:
   1384 				return ip_getmoptions(*mopts, sopt);
   1385 			case PRCO_SETOPT:
   1386 				return ip_setmoptions(mopts, sopt);
   1387 			default:
   1388 				return EINVAL;
   1389 			}
   1390 		default:
   1391 			return ENOPROTOOPT;
   1392 		}
   1393 	case IPPROTO_IPV6:
   1394 		break;
   1395 	default:
   1396 		return ENOPROTOOPT;
   1397 	}
   1398 	switch (op) {
   1399 	case PRCO_SETOPT:
   1400 		switch (optname) {
   1401 #ifdef RFC2292
   1402 		case IPV6_2292PKTOPTIONS:
   1403 			error = ip6_pcbopts(&in6p->in6p_outputopts, so, sopt);
   1404 			break;
   1405 #endif
   1406 
   1407 		/*
   1408 		 * Use of some Hop-by-Hop options or some
   1409 		 * Destination options, might require special
   1410 		 * privilege.  That is, normal applications
   1411 		 * (without special privilege) might be forbidden
   1412 		 * from setting certain options in outgoing packets,
   1413 		 * and might never see certain options in received
   1414 		 * packets. [RFC 2292 Section 6]
   1415 		 * KAME specific note:
   1416 		 *  KAME prevents non-privileged users from sending or
   1417 		 *  receiving ANY hbh/dst options in order to avoid
   1418 		 *  overhead of parsing options in the kernel.
   1419 		 */
   1420 		case IPV6_RECVHOPOPTS:
   1421 		case IPV6_RECVDSTOPTS:
   1422 		case IPV6_RECVRTHDRDSTOPTS:
   1423 			error = kauth_authorize_network(kauth_cred_get(),
   1424 			    KAUTH_NETWORK_IPV6, KAUTH_REQ_NETWORK_IPV6_HOPBYHOP,
   1425 			    NULL, NULL, NULL);
   1426 			if (error)
   1427 				break;
   1428 			/* FALLTHROUGH */
   1429 		case IPV6_UNICAST_HOPS:
   1430 		case IPV6_HOPLIMIT:
   1431 		case IPV6_FAITH:
   1432 
   1433 		case IPV6_RECVPKTINFO:
   1434 		case IPV6_RECVHOPLIMIT:
   1435 		case IPV6_RECVRTHDR:
   1436 		case IPV6_RECVPATHMTU:
   1437 		case IPV6_RECVTCLASS:
   1438 		case IPV6_V6ONLY:
   1439 			error = sockopt_getint(sopt, &optval);
   1440 			if (error)
   1441 				break;
   1442 			switch (optname) {
   1443 			case IPV6_UNICAST_HOPS:
   1444 				if (optval < -1 || optval >= 256)
   1445 					error = EINVAL;
   1446 				else {
   1447 					/* -1 = kernel default */
   1448 					in6p->in6p_hops = optval;
   1449 				}
   1450 				break;
   1451 #define OPTSET(bit) \
   1452 do { \
   1453 if (optval) \
   1454 	in6p->in6p_flags |= (bit); \
   1455 else \
   1456 	in6p->in6p_flags &= ~(bit); \
   1457 } while (/*CONSTCOND*/ 0)
   1458 
   1459 #ifdef RFC2292
   1460 #define OPTSET2292(bit) 			\
   1461 do { 						\
   1462 in6p->in6p_flags |= IN6P_RFC2292; 	\
   1463 if (optval) 				\
   1464 	in6p->in6p_flags |= (bit); 	\
   1465 else 					\
   1466 	in6p->in6p_flags &= ~(bit); 	\
   1467 } while (/*CONSTCOND*/ 0)
   1468 #endif
   1469 
   1470 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
   1471 
   1472 			case IPV6_RECVPKTINFO:
   1473 #ifdef RFC2292
   1474 				/* cannot mix with RFC2292 */
   1475 				if (OPTBIT(IN6P_RFC2292)) {
   1476 					error = EINVAL;
   1477 					break;
   1478 				}
   1479 #endif
   1480 				OPTSET(IN6P_PKTINFO);
   1481 				break;
   1482 
   1483 			case IPV6_HOPLIMIT:
   1484 			{
   1485 				struct ip6_pktopts **optp;
   1486 
   1487 #ifdef RFC2292
   1488 				/* cannot mix with RFC2292 */
   1489 				if (OPTBIT(IN6P_RFC2292)) {
   1490 					error = EINVAL;
   1491 					break;
   1492 				}
   1493 #endif
   1494 				optp = &in6p->in6p_outputopts;
   1495 				error = ip6_pcbopt(IPV6_HOPLIMIT,
   1496 						   (u_char *)&optval,
   1497 						   sizeof(optval),
   1498 						   optp,
   1499 						   kauth_cred_get(), uproto);
   1500 				break;
   1501 			}
   1502 
   1503 			case IPV6_RECVHOPLIMIT:
   1504 #ifdef RFC2292
   1505 				/* cannot mix with RFC2292 */
   1506 				if (OPTBIT(IN6P_RFC2292)) {
   1507 					error = EINVAL;
   1508 					break;
   1509 				}
   1510 #endif
   1511 				OPTSET(IN6P_HOPLIMIT);
   1512 				break;
   1513 
   1514 			case IPV6_RECVHOPOPTS:
   1515 #ifdef RFC2292
   1516 				/* cannot mix with RFC2292 */
   1517 				if (OPTBIT(IN6P_RFC2292)) {
   1518 					error = EINVAL;
   1519 					break;
   1520 				}
   1521 #endif
   1522 				OPTSET(IN6P_HOPOPTS);
   1523 				break;
   1524 
   1525 			case IPV6_RECVDSTOPTS:
   1526 #ifdef RFC2292
   1527 				/* cannot mix with RFC2292 */
   1528 				if (OPTBIT(IN6P_RFC2292)) {
   1529 					error = EINVAL;
   1530 					break;
   1531 				}
   1532 #endif
   1533 				OPTSET(IN6P_DSTOPTS);
   1534 				break;
   1535 
   1536 			case IPV6_RECVRTHDRDSTOPTS:
   1537 #ifdef RFC2292
   1538 				/* cannot mix with RFC2292 */
   1539 				if (OPTBIT(IN6P_RFC2292)) {
   1540 					error = EINVAL;
   1541 					break;
   1542 				}
   1543 #endif
   1544 				OPTSET(IN6P_RTHDRDSTOPTS);
   1545 				break;
   1546 
   1547 			case IPV6_RECVRTHDR:
   1548 #ifdef RFC2292
   1549 				/* cannot mix with RFC2292 */
   1550 				if (OPTBIT(IN6P_RFC2292)) {
   1551 					error = EINVAL;
   1552 					break;
   1553 				}
   1554 #endif
   1555 				OPTSET(IN6P_RTHDR);
   1556 				break;
   1557 
   1558 			case IPV6_FAITH:
   1559 				OPTSET(IN6P_FAITH);
   1560 				break;
   1561 
   1562 			case IPV6_RECVPATHMTU:
   1563 				/*
   1564 				 * We ignore this option for TCP
   1565 				 * sockets.
   1566 				 * (RFC3542 leaves this case
   1567 				 * unspecified.)
   1568 				 */
   1569 				if (uproto != IPPROTO_TCP)
   1570 					OPTSET(IN6P_MTU);
   1571 				break;
   1572 
   1573 			case IPV6_V6ONLY:
   1574 				/*
   1575 				 * make setsockopt(IPV6_V6ONLY)
   1576 				 * available only prior to bind(2).
   1577 				 * see ipng mailing list, Jun 22 2001.
   1578 				 */
   1579 				if (in6p->in6p_lport ||
   1580 				    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
   1581 					error = EINVAL;
   1582 					break;
   1583 				}
   1584 #ifdef INET6_BINDV6ONLY
   1585 				if (!optval)
   1586 					error = EINVAL;
   1587 #else
   1588 				OPTSET(IN6P_IPV6_V6ONLY);
   1589 #endif
   1590 				break;
   1591 			case IPV6_RECVTCLASS:
   1592 #ifdef RFC2292
   1593 				/* cannot mix with RFC2292 XXX */
   1594 				if (OPTBIT(IN6P_RFC2292)) {
   1595 					error = EINVAL;
   1596 					break;
   1597 				}
   1598 #endif
   1599 				OPTSET(IN6P_TCLASS);
   1600 				break;
   1601 
   1602 			}
   1603 			break;
   1604 
   1605 		case IPV6_OTCLASS:
   1606 		{
   1607 			struct ip6_pktopts **optp;
   1608 			u_int8_t tclass;
   1609 
   1610 			error = sockopt_get(sopt, &tclass, sizeof(tclass));
   1611 			if (error)
   1612 				break;
   1613 			optp = &in6p->in6p_outputopts;
   1614 			error = ip6_pcbopt(optname,
   1615 					   (u_char *)&tclass,
   1616 					   sizeof(tclass),
   1617 					   optp,
   1618 					   kauth_cred_get(), uproto);
   1619 			break;
   1620 		}
   1621 
   1622 		case IPV6_TCLASS:
   1623 		case IPV6_DONTFRAG:
   1624 		case IPV6_USE_MIN_MTU:
   1625 		case IPV6_PREFER_TEMPADDR:
   1626 			error = sockopt_getint(sopt, &optval);
   1627 			if (error)
   1628 				break;
   1629 			{
   1630 				struct ip6_pktopts **optp;
   1631 				optp = &in6p->in6p_outputopts;
   1632 				error = ip6_pcbopt(optname,
   1633 						   (u_char *)&optval,
   1634 						   sizeof(optval),
   1635 						   optp,
   1636 						   kauth_cred_get(), uproto);
   1637 				break;
   1638 			}
   1639 
   1640 #ifdef RFC2292
   1641 		case IPV6_2292PKTINFO:
   1642 		case IPV6_2292HOPLIMIT:
   1643 		case IPV6_2292HOPOPTS:
   1644 		case IPV6_2292DSTOPTS:
   1645 		case IPV6_2292RTHDR:
   1646 			/* RFC 2292 */
   1647 			error = sockopt_getint(sopt, &optval);
   1648 			if (error)
   1649 				break;
   1650 
   1651 			switch (optname) {
   1652 			case IPV6_2292PKTINFO:
   1653 				OPTSET2292(IN6P_PKTINFO);
   1654 				break;
   1655 			case IPV6_2292HOPLIMIT:
   1656 				OPTSET2292(IN6P_HOPLIMIT);
   1657 				break;
   1658 			case IPV6_2292HOPOPTS:
   1659 				/*
   1660 				 * Check super-user privilege.
   1661 				 * See comments for IPV6_RECVHOPOPTS.
   1662 				 */
   1663 				error =
   1664 				    kauth_authorize_network(kauth_cred_get(),
   1665 				    KAUTH_NETWORK_IPV6,
   1666 				    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL,
   1667 				    NULL, NULL);
   1668 				if (error)
   1669 					return (error);
   1670 				OPTSET2292(IN6P_HOPOPTS);
   1671 				break;
   1672 			case IPV6_2292DSTOPTS:
   1673 				error =
   1674 				    kauth_authorize_network(kauth_cred_get(),
   1675 				    KAUTH_NETWORK_IPV6,
   1676 				    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL,
   1677 				    NULL, NULL);
   1678 				if (error)
   1679 					return (error);
   1680 				OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
   1681 				break;
   1682 			case IPV6_2292RTHDR:
   1683 				OPTSET2292(IN6P_RTHDR);
   1684 				break;
   1685 			}
   1686 			break;
   1687 #endif
   1688 		case IPV6_PKTINFO:
   1689 		case IPV6_HOPOPTS:
   1690 		case IPV6_RTHDR:
   1691 		case IPV6_DSTOPTS:
   1692 		case IPV6_RTHDRDSTOPTS:
   1693 		case IPV6_NEXTHOP: {
   1694 			/* new advanced API (RFC3542) */
   1695 			void *optbuf;
   1696 			int optbuflen;
   1697 			struct ip6_pktopts **optp;
   1698 
   1699 #ifdef RFC2292
   1700 			/* cannot mix with RFC2292 */
   1701 			if (OPTBIT(IN6P_RFC2292)) {
   1702 				error = EINVAL;
   1703 				break;
   1704 			}
   1705 #endif
   1706 
   1707 			optbuflen = sopt->sopt_size;
   1708 			optbuf = malloc(optbuflen, M_IP6OPT, M_NOWAIT);
   1709 			if (optbuf == NULL) {
   1710 				error = ENOBUFS;
   1711 				break;
   1712 			}
   1713 
   1714 			error = sockopt_get(sopt, optbuf, optbuflen);
   1715 			if (error) {
   1716 				free(optbuf, M_IP6OPT);
   1717 				break;
   1718 			}
   1719 			optp = &in6p->in6p_outputopts;
   1720 			error = ip6_pcbopt(optname, optbuf, optbuflen,
   1721 			    optp, kauth_cred_get(), uproto);
   1722 
   1723 			free(optbuf, M_IP6OPT);
   1724 			break;
   1725 			}
   1726 #undef OPTSET
   1727 
   1728 		case IPV6_MULTICAST_IF:
   1729 		case IPV6_MULTICAST_HOPS:
   1730 		case IPV6_MULTICAST_LOOP:
   1731 		case IPV6_JOIN_GROUP:
   1732 		case IPV6_LEAVE_GROUP:
   1733 			error = ip6_setmoptions(sopt, in6p);
   1734 			break;
   1735 
   1736 		case IPV6_PORTRANGE:
   1737 			error = sockopt_getint(sopt, &optval);
   1738 			if (error)
   1739 				break;
   1740 
   1741 			switch (optval) {
   1742 			case IPV6_PORTRANGE_DEFAULT:
   1743 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1744 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1745 				break;
   1746 
   1747 			case IPV6_PORTRANGE_HIGH:
   1748 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1749 				in6p->in6p_flags |= IN6P_HIGHPORT;
   1750 				break;
   1751 
   1752 			case IPV6_PORTRANGE_LOW:
   1753 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1754 				in6p->in6p_flags |= IN6P_LOWPORT;
   1755 				break;
   1756 
   1757 			default:
   1758 				error = EINVAL;
   1759 				break;
   1760 			}
   1761 			break;
   1762 
   1763 		case IPV6_PORTALGO:
   1764 			error = sockopt_getint(sopt, &optval);
   1765 			if (error)
   1766 				break;
   1767 
   1768 			error = portalgo_algo_index_select(
   1769 			    (struct inpcb_hdr *)in6p, optval);
   1770 			break;
   1771 
   1772 #if defined(IPSEC)
   1773 		case IPV6_IPSEC_POLICY:
   1774 			if (ipsec_enabled) {
   1775 				error = ipsec_set_policy(in6p, optname,
   1776 				    sopt->sopt_data, sopt->sopt_size,
   1777 				    kauth_cred_get());
   1778 				break;
   1779 			}
   1780 			/*FALLTHROUGH*/
   1781 #endif /* IPSEC */
   1782 
   1783 		default:
   1784 			error = ENOPROTOOPT;
   1785 			break;
   1786 		}
   1787 		break;
   1788 
   1789 	case PRCO_GETOPT:
   1790 		switch (optname) {
   1791 #ifdef RFC2292
   1792 		case IPV6_2292PKTOPTIONS:
   1793 			/*
   1794 			 * RFC3542 (effectively) deprecated the
   1795 			 * semantics of the 2292-style pktoptions.
   1796 			 * Since it was not reliable in nature (i.e.,
   1797 			 * applications had to expect the lack of some
   1798 			 * information after all), it would make sense
   1799 			 * to simplify this part by always returning
   1800 			 * empty data.
   1801 			 */
   1802 			break;
   1803 #endif
   1804 
   1805 		case IPV6_RECVHOPOPTS:
   1806 		case IPV6_RECVDSTOPTS:
   1807 		case IPV6_RECVRTHDRDSTOPTS:
   1808 		case IPV6_UNICAST_HOPS:
   1809 		case IPV6_RECVPKTINFO:
   1810 		case IPV6_RECVHOPLIMIT:
   1811 		case IPV6_RECVRTHDR:
   1812 		case IPV6_RECVPATHMTU:
   1813 
   1814 		case IPV6_FAITH:
   1815 		case IPV6_V6ONLY:
   1816 		case IPV6_PORTRANGE:
   1817 		case IPV6_RECVTCLASS:
   1818 			switch (optname) {
   1819 
   1820 			case IPV6_RECVHOPOPTS:
   1821 				optval = OPTBIT(IN6P_HOPOPTS);
   1822 				break;
   1823 
   1824 			case IPV6_RECVDSTOPTS:
   1825 				optval = OPTBIT(IN6P_DSTOPTS);
   1826 				break;
   1827 
   1828 			case IPV6_RECVRTHDRDSTOPTS:
   1829 				optval = OPTBIT(IN6P_RTHDRDSTOPTS);
   1830 				break;
   1831 
   1832 			case IPV6_UNICAST_HOPS:
   1833 				optval = in6p->in6p_hops;
   1834 				break;
   1835 
   1836 			case IPV6_RECVPKTINFO:
   1837 				optval = OPTBIT(IN6P_PKTINFO);
   1838 				break;
   1839 
   1840 			case IPV6_RECVHOPLIMIT:
   1841 				optval = OPTBIT(IN6P_HOPLIMIT);
   1842 				break;
   1843 
   1844 			case IPV6_RECVRTHDR:
   1845 				optval = OPTBIT(IN6P_RTHDR);
   1846 				break;
   1847 
   1848 			case IPV6_RECVPATHMTU:
   1849 				optval = OPTBIT(IN6P_MTU);
   1850 				break;
   1851 
   1852 			case IPV6_FAITH:
   1853 				optval = OPTBIT(IN6P_FAITH);
   1854 				break;
   1855 
   1856 			case IPV6_V6ONLY:
   1857 				optval = OPTBIT(IN6P_IPV6_V6ONLY);
   1858 				break;
   1859 
   1860 			case IPV6_PORTRANGE:
   1861 			    {
   1862 				int flags;
   1863 				flags = in6p->in6p_flags;
   1864 				if (flags & IN6P_HIGHPORT)
   1865 					optval = IPV6_PORTRANGE_HIGH;
   1866 				else if (flags & IN6P_LOWPORT)
   1867 					optval = IPV6_PORTRANGE_LOW;
   1868 				else
   1869 					optval = 0;
   1870 				break;
   1871 			    }
   1872 			case IPV6_RECVTCLASS:
   1873 				optval = OPTBIT(IN6P_TCLASS);
   1874 				break;
   1875 
   1876 			}
   1877 			if (error)
   1878 				break;
   1879 			error = sockopt_setint(sopt, optval);
   1880 			break;
   1881 
   1882 		case IPV6_PATHMTU:
   1883 		    {
   1884 			u_long pmtu = 0;
   1885 			struct ip6_mtuinfo mtuinfo;
   1886 			struct route *ro = &in6p->in6p_route;
   1887 			struct rtentry *rt;
   1888 			union {
   1889 				struct sockaddr		dst;
   1890 				struct sockaddr_in6	dst6;
   1891 			} u;
   1892 
   1893 			if (!(so->so_state & SS_ISCONNECTED))
   1894 				return (ENOTCONN);
   1895 			/*
   1896 			 * XXX: we dot not consider the case of source
   1897 			 * routing, or optional information to specify
   1898 			 * the outgoing interface.
   1899 			 */
   1900 			sockaddr_in6_init(&u.dst6, &in6p->in6p_faddr, 0, 0, 0);
   1901 			rt = rtcache_lookup(ro, &u.dst);
   1902 			error = ip6_getpmtu(rt, NULL, &pmtu, NULL);
   1903 			rtcache_unref(rt, ro);
   1904 			if (error)
   1905 				break;
   1906 			if (pmtu > IPV6_MAXPACKET)
   1907 				pmtu = IPV6_MAXPACKET;
   1908 
   1909 			memset(&mtuinfo, 0, sizeof(mtuinfo));
   1910 			mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
   1911 			optdata = (void *)&mtuinfo;
   1912 			optdatalen = sizeof(mtuinfo);
   1913 			if (optdatalen > MCLBYTES)
   1914 				return (EMSGSIZE); /* XXX */
   1915 			error = sockopt_set(sopt, optdata, optdatalen);
   1916 			break;
   1917 		    }
   1918 
   1919 #ifdef RFC2292
   1920 		case IPV6_2292PKTINFO:
   1921 		case IPV6_2292HOPLIMIT:
   1922 		case IPV6_2292HOPOPTS:
   1923 		case IPV6_2292RTHDR:
   1924 		case IPV6_2292DSTOPTS:
   1925 			switch (optname) {
   1926 			case IPV6_2292PKTINFO:
   1927 				optval = OPTBIT(IN6P_PKTINFO);
   1928 				break;
   1929 			case IPV6_2292HOPLIMIT:
   1930 				optval = OPTBIT(IN6P_HOPLIMIT);
   1931 				break;
   1932 			case IPV6_2292HOPOPTS:
   1933 				optval = OPTBIT(IN6P_HOPOPTS);
   1934 				break;
   1935 			case IPV6_2292RTHDR:
   1936 				optval = OPTBIT(IN6P_RTHDR);
   1937 				break;
   1938 			case IPV6_2292DSTOPTS:
   1939 				optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
   1940 				break;
   1941 			}
   1942 			error = sockopt_setint(sopt, optval);
   1943 			break;
   1944 #endif
   1945 		case IPV6_PKTINFO:
   1946 		case IPV6_HOPOPTS:
   1947 		case IPV6_RTHDR:
   1948 		case IPV6_DSTOPTS:
   1949 		case IPV6_RTHDRDSTOPTS:
   1950 		case IPV6_NEXTHOP:
   1951 		case IPV6_OTCLASS:
   1952 		case IPV6_TCLASS:
   1953 		case IPV6_DONTFRAG:
   1954 		case IPV6_USE_MIN_MTU:
   1955 		case IPV6_PREFER_TEMPADDR:
   1956 			error = ip6_getpcbopt(in6p->in6p_outputopts,
   1957 			    optname, sopt);
   1958 			break;
   1959 
   1960 		case IPV6_MULTICAST_IF:
   1961 		case IPV6_MULTICAST_HOPS:
   1962 		case IPV6_MULTICAST_LOOP:
   1963 		case IPV6_JOIN_GROUP:
   1964 		case IPV6_LEAVE_GROUP:
   1965 			error = ip6_getmoptions(sopt, in6p);
   1966 			break;
   1967 
   1968 		case IPV6_PORTALGO:
   1969 			optval = ((struct inpcb_hdr *)in6p)->inph_portalgo;
   1970 			error = sockopt_setint(sopt, optval);
   1971 			break;
   1972 
   1973 #if defined(IPSEC)
   1974 		case IPV6_IPSEC_POLICY:
   1975 			if (ipsec_used) {
   1976 				struct mbuf *m = NULL;
   1977 
   1978 				/*
   1979 				 * XXX: this will return EINVAL as sopt is
   1980 				 * empty
   1981 				 */
   1982 				error = ipsec_get_policy(in6p, sopt->sopt_data,
   1983 				    sopt->sopt_size, &m);
   1984 				if (!error)
   1985 					error = sockopt_setmbuf(sopt, m);
   1986 				break;
   1987 			}
   1988 			/*FALLTHROUGH*/
   1989 #endif /* IPSEC */
   1990 
   1991 		default:
   1992 			error = ENOPROTOOPT;
   1993 			break;
   1994 		}
   1995 		break;
   1996 	}
   1997 	return (error);
   1998 }
   1999 
   2000 int
   2001 ip6_raw_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   2002 {
   2003 	int error = 0, optval;
   2004 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
   2005 	struct in6pcb *in6p = sotoin6pcb(so);
   2006 	int level, optname;
   2007 
   2008 	KASSERT(sopt != NULL);
   2009 
   2010 	level = sopt->sopt_level;
   2011 	optname = sopt->sopt_name;
   2012 
   2013 	if (level != IPPROTO_IPV6) {
   2014 		return ENOPROTOOPT;
   2015 	}
   2016 
   2017 	switch (optname) {
   2018 	case IPV6_CHECKSUM:
   2019 		/*
   2020 		 * For ICMPv6 sockets, no modification allowed for checksum
   2021 		 * offset, permit "no change" values to help existing apps.
   2022 		 *
   2023 		 * XXX RFC3542 says: "An attempt to set IPV6_CHECKSUM
   2024 		 * for an ICMPv6 socket will fail."  The current
   2025 		 * behavior does not meet RFC3542.
   2026 		 */
   2027 		switch (op) {
   2028 		case PRCO_SETOPT:
   2029 			error = sockopt_getint(sopt, &optval);
   2030 			if (error)
   2031 				break;
   2032 			if ((optval % 2) != 0) {
   2033 				/* the API assumes even offset values */
   2034 				error = EINVAL;
   2035 			} else if (so->so_proto->pr_protocol ==
   2036 			    IPPROTO_ICMPV6) {
   2037 				if (optval != icmp6off)
   2038 					error = EINVAL;
   2039 			} else
   2040 				in6p->in6p_cksum = optval;
   2041 			break;
   2042 
   2043 		case PRCO_GETOPT:
   2044 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
   2045 				optval = icmp6off;
   2046 			else
   2047 				optval = in6p->in6p_cksum;
   2048 
   2049 			error = sockopt_setint(sopt, optval);
   2050 			break;
   2051 
   2052 		default:
   2053 			error = EINVAL;
   2054 			break;
   2055 		}
   2056 		break;
   2057 
   2058 	default:
   2059 		error = ENOPROTOOPT;
   2060 		break;
   2061 	}
   2062 
   2063 	return (error);
   2064 }
   2065 
   2066 #ifdef RFC2292
   2067 /*
   2068  * Set up IP6 options in pcb for insertion in output packets or
   2069  * specifying behavior of outgoing packets.
   2070  */
   2071 static int
   2072 ip6_pcbopts(struct ip6_pktopts **pktopt, struct socket *so,
   2073     struct sockopt *sopt)
   2074 {
   2075 	struct ip6_pktopts *opt = *pktopt;
   2076 	struct mbuf *m;
   2077 	int error = 0;
   2078 
   2079 	KASSERT(solocked(so));
   2080 
   2081 	/* turn off any old options. */
   2082 	if (opt) {
   2083 #ifdef DIAGNOSTIC
   2084 	    if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
   2085 		opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
   2086 		opt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2087 		    printf("ip6_pcbopts: all specified options are cleared.\n");
   2088 #endif
   2089 		ip6_clearpktopts(opt, -1);
   2090 	} else {
   2091 		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
   2092 		if (opt == NULL)
   2093 			return (ENOBUFS);
   2094 	}
   2095 	*pktopt = NULL;
   2096 
   2097 	if (sopt == NULL || sopt->sopt_size == 0) {
   2098 		/*
   2099 		 * Only turning off any previous options, regardless of
   2100 		 * whether the opt is just created or given.
   2101 		 */
   2102 		free(opt, M_IP6OPT);
   2103 		return (0);
   2104 	}
   2105 
   2106 	/*  set options specified by user. */
   2107 	m = sockopt_getmbuf(sopt);
   2108 	if (m == NULL) {
   2109 		free(opt, M_IP6OPT);
   2110 		return (ENOBUFS);
   2111 	}
   2112 
   2113 	error = ip6_setpktopts(m, opt, NULL, kauth_cred_get(),
   2114 	    so->so_proto->pr_protocol);
   2115 	m_freem(m);
   2116 	if (error != 0) {
   2117 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
   2118 		free(opt, M_IP6OPT);
   2119 		return (error);
   2120 	}
   2121 	*pktopt = opt;
   2122 	return (0);
   2123 }
   2124 #endif
   2125 
   2126 /*
   2127  * initialize ip6_pktopts.  beware that there are non-zero default values in
   2128  * the struct.
   2129  */
   2130 void
   2131 ip6_initpktopts(struct ip6_pktopts *opt)
   2132 {
   2133 
   2134 	memset(opt, 0, sizeof(*opt));
   2135 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
   2136 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
   2137 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
   2138 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
   2139 }
   2140 
   2141 #define sin6tosa(sin6)	((struct sockaddr *)(sin6)) /* XXX */
   2142 static int
   2143 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
   2144     kauth_cred_t cred, int uproto)
   2145 {
   2146 	struct ip6_pktopts *opt;
   2147 
   2148 	if (*pktopt == NULL) {
   2149 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
   2150 		    M_NOWAIT);
   2151 		if (*pktopt == NULL)
   2152 			return (ENOBUFS);
   2153 
   2154 		ip6_initpktopts(*pktopt);
   2155 	}
   2156 	opt = *pktopt;
   2157 
   2158 	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
   2159 }
   2160 
   2161 static int
   2162 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
   2163 {
   2164 	void *optdata = NULL;
   2165 	int optdatalen = 0;
   2166 	struct ip6_ext *ip6e;
   2167 	int error = 0;
   2168 	struct in6_pktinfo null_pktinfo;
   2169 	int deftclass = 0, on;
   2170 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
   2171 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
   2172 
   2173 	switch (optname) {
   2174 	case IPV6_PKTINFO:
   2175 		if (pktopt && pktopt->ip6po_pktinfo)
   2176 			optdata = (void *)pktopt->ip6po_pktinfo;
   2177 		else {
   2178 			/* XXX: we don't have to do this every time... */
   2179 			memset(&null_pktinfo, 0, sizeof(null_pktinfo));
   2180 			optdata = (void *)&null_pktinfo;
   2181 		}
   2182 		optdatalen = sizeof(struct in6_pktinfo);
   2183 		break;
   2184 	case IPV6_OTCLASS:
   2185 		/* XXX */
   2186 		return (EINVAL);
   2187 	case IPV6_TCLASS:
   2188 		if (pktopt && pktopt->ip6po_tclass >= 0)
   2189 			optdata = (void *)&pktopt->ip6po_tclass;
   2190 		else
   2191 			optdata = (void *)&deftclass;
   2192 		optdatalen = sizeof(int);
   2193 		break;
   2194 	case IPV6_HOPOPTS:
   2195 		if (pktopt && pktopt->ip6po_hbh) {
   2196 			optdata = (void *)pktopt->ip6po_hbh;
   2197 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
   2198 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2199 		}
   2200 		break;
   2201 	case IPV6_RTHDR:
   2202 		if (pktopt && pktopt->ip6po_rthdr) {
   2203 			optdata = (void *)pktopt->ip6po_rthdr;
   2204 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
   2205 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2206 		}
   2207 		break;
   2208 	case IPV6_RTHDRDSTOPTS:
   2209 		if (pktopt && pktopt->ip6po_dest1) {
   2210 			optdata = (void *)pktopt->ip6po_dest1;
   2211 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
   2212 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2213 		}
   2214 		break;
   2215 	case IPV6_DSTOPTS:
   2216 		if (pktopt && pktopt->ip6po_dest2) {
   2217 			optdata = (void *)pktopt->ip6po_dest2;
   2218 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
   2219 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2220 		}
   2221 		break;
   2222 	case IPV6_NEXTHOP:
   2223 		if (pktopt && pktopt->ip6po_nexthop) {
   2224 			optdata = (void *)pktopt->ip6po_nexthop;
   2225 			optdatalen = pktopt->ip6po_nexthop->sa_len;
   2226 		}
   2227 		break;
   2228 	case IPV6_USE_MIN_MTU:
   2229 		if (pktopt)
   2230 			optdata = (void *)&pktopt->ip6po_minmtu;
   2231 		else
   2232 			optdata = (void *)&defminmtu;
   2233 		optdatalen = sizeof(int);
   2234 		break;
   2235 	case IPV6_DONTFRAG:
   2236 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
   2237 			on = 1;
   2238 		else
   2239 			on = 0;
   2240 		optdata = (void *)&on;
   2241 		optdatalen = sizeof(on);
   2242 		break;
   2243 	case IPV6_PREFER_TEMPADDR:
   2244 		if (pktopt)
   2245 			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
   2246 		else
   2247 			optdata = (void *)&defpreftemp;
   2248 		optdatalen = sizeof(int);
   2249 		break;
   2250 	default:		/* should not happen */
   2251 #ifdef DIAGNOSTIC
   2252 		panic("ip6_getpcbopt: unexpected option\n");
   2253 #endif
   2254 		return (ENOPROTOOPT);
   2255 	}
   2256 
   2257 	error = sockopt_set(sopt, optdata, optdatalen);
   2258 
   2259 	return (error);
   2260 }
   2261 
   2262 void
   2263 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
   2264 {
   2265 	if (optname == -1 || optname == IPV6_PKTINFO) {
   2266 		if (pktopt->ip6po_pktinfo)
   2267 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
   2268 		pktopt->ip6po_pktinfo = NULL;
   2269 	}
   2270 	if (optname == -1 || optname == IPV6_HOPLIMIT)
   2271 		pktopt->ip6po_hlim = -1;
   2272 	if (optname == -1 || optname == IPV6_TCLASS)
   2273 		pktopt->ip6po_tclass = -1;
   2274 	if (optname == -1 || optname == IPV6_NEXTHOP) {
   2275 		rtcache_free(&pktopt->ip6po_nextroute);
   2276 		if (pktopt->ip6po_nexthop)
   2277 			free(pktopt->ip6po_nexthop, M_IP6OPT);
   2278 		pktopt->ip6po_nexthop = NULL;
   2279 	}
   2280 	if (optname == -1 || optname == IPV6_HOPOPTS) {
   2281 		if (pktopt->ip6po_hbh)
   2282 			free(pktopt->ip6po_hbh, M_IP6OPT);
   2283 		pktopt->ip6po_hbh = NULL;
   2284 	}
   2285 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
   2286 		if (pktopt->ip6po_dest1)
   2287 			free(pktopt->ip6po_dest1, M_IP6OPT);
   2288 		pktopt->ip6po_dest1 = NULL;
   2289 	}
   2290 	if (optname == -1 || optname == IPV6_RTHDR) {
   2291 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2292 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
   2293 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
   2294 		rtcache_free(&pktopt->ip6po_route);
   2295 	}
   2296 	if (optname == -1 || optname == IPV6_DSTOPTS) {
   2297 		if (pktopt->ip6po_dest2)
   2298 			free(pktopt->ip6po_dest2, M_IP6OPT);
   2299 		pktopt->ip6po_dest2 = NULL;
   2300 	}
   2301 }
   2302 
   2303 #define PKTOPT_EXTHDRCPY(type) 					\
   2304 do {								\
   2305 	if (src->type) {					\
   2306 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
   2307 		dst->type = malloc(hlen, M_IP6OPT, canwait);	\
   2308 		if (dst->type == NULL)				\
   2309 			goto bad;				\
   2310 		memcpy(dst->type, src->type, hlen);		\
   2311 	}							\
   2312 } while (/*CONSTCOND*/ 0)
   2313 
   2314 static int
   2315 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
   2316 {
   2317 	dst->ip6po_hlim = src->ip6po_hlim;
   2318 	dst->ip6po_tclass = src->ip6po_tclass;
   2319 	dst->ip6po_flags = src->ip6po_flags;
   2320 	dst->ip6po_minmtu = src->ip6po_minmtu;
   2321 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
   2322 	if (src->ip6po_pktinfo) {
   2323 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
   2324 		    M_IP6OPT, canwait);
   2325 		if (dst->ip6po_pktinfo == NULL)
   2326 			goto bad;
   2327 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
   2328 	}
   2329 	if (src->ip6po_nexthop) {
   2330 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
   2331 		    M_IP6OPT, canwait);
   2332 		if (dst->ip6po_nexthop == NULL)
   2333 			goto bad;
   2334 		memcpy(dst->ip6po_nexthop, src->ip6po_nexthop,
   2335 		    src->ip6po_nexthop->sa_len);
   2336 	}
   2337 	PKTOPT_EXTHDRCPY(ip6po_hbh);
   2338 	PKTOPT_EXTHDRCPY(ip6po_dest1);
   2339 	PKTOPT_EXTHDRCPY(ip6po_dest2);
   2340 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
   2341 	return (0);
   2342 
   2343   bad:
   2344 	if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
   2345 	if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
   2346 	if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
   2347 	if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
   2348 	if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
   2349 	if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
   2350 
   2351 	return (ENOBUFS);
   2352 }
   2353 #undef PKTOPT_EXTHDRCPY
   2354 
   2355 struct ip6_pktopts *
   2356 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
   2357 {
   2358 	int error;
   2359 	struct ip6_pktopts *dst;
   2360 
   2361 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
   2362 	if (dst == NULL)
   2363 		return (NULL);
   2364 	ip6_initpktopts(dst);
   2365 
   2366 	if ((error = copypktopts(dst, src, canwait)) != 0) {
   2367 		free(dst, M_IP6OPT);
   2368 		return (NULL);
   2369 	}
   2370 
   2371 	return (dst);
   2372 }
   2373 
   2374 void
   2375 ip6_freepcbopts(struct ip6_pktopts *pktopt)
   2376 {
   2377 	if (pktopt == NULL)
   2378 		return;
   2379 
   2380 	ip6_clearpktopts(pktopt, -1);
   2381 
   2382 	free(pktopt, M_IP6OPT);
   2383 }
   2384 
   2385 int
   2386 ip6_get_membership(const struct sockopt *sopt, struct ifnet **ifp,
   2387     struct psref *psref, void *v, size_t l)
   2388 {
   2389 	struct ipv6_mreq mreq;
   2390 	int error;
   2391 	struct in6_addr *ia = &mreq.ipv6mr_multiaddr;
   2392 	struct in_addr *ia4 = (void *)&ia->s6_addr32[3];
   2393 
   2394 	error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2395 	if (error != 0)
   2396 		return error;
   2397 
   2398 	if (IN6_IS_ADDR_UNSPECIFIED(ia)) {
   2399 		/*
   2400 		 * We use the unspecified address to specify to accept
   2401 		 * all multicast addresses. Only super user is allowed
   2402 		 * to do this.
   2403 		 */
   2404 		if (kauth_authorize_network(curlwp->l_cred, KAUTH_NETWORK_IPV6,
   2405 		    KAUTH_REQ_NETWORK_IPV6_JOIN_MULTICAST, NULL, NULL, NULL))
   2406 			return EACCES;
   2407 	} else if (IN6_IS_ADDR_V4MAPPED(ia)) {
   2408 		// Don't bother if we are not going to use ifp.
   2409 		if (l == sizeof(*ia)) {
   2410 			memcpy(v, ia, l);
   2411 			return 0;
   2412 		}
   2413 	} else if (!IN6_IS_ADDR_MULTICAST(ia)) {
   2414 		return EINVAL;
   2415 	}
   2416 
   2417 	/*
   2418 	 * If no interface was explicitly specified, choose an
   2419 	 * appropriate one according to the given multicast address.
   2420 	 */
   2421 	if (mreq.ipv6mr_interface == 0) {
   2422 		struct rtentry *rt;
   2423 		union {
   2424 			struct sockaddr		dst;
   2425 			struct sockaddr_in	dst4;
   2426 			struct sockaddr_in6	dst6;
   2427 		} u;
   2428 		struct route ro;
   2429 
   2430 		/*
   2431 		 * Look up the routing table for the
   2432 		 * address, and choose the outgoing interface.
   2433 		 *   XXX: is it a good approach?
   2434 		 */
   2435 		memset(&ro, 0, sizeof(ro));
   2436 		if (IN6_IS_ADDR_V4MAPPED(ia))
   2437 			sockaddr_in_init(&u.dst4, ia4, 0);
   2438 		else
   2439 			sockaddr_in6_init(&u.dst6, ia, 0, 0, 0);
   2440 		error = rtcache_setdst(&ro, &u.dst);
   2441 		if (error != 0)
   2442 			return error;
   2443 		rt = rtcache_init(&ro);
   2444 		*ifp = rt != NULL ?
   2445 		    if_get_byindex(rt->rt_ifp->if_index, psref) : NULL;
   2446 		rtcache_unref(rt, &ro);
   2447 		rtcache_free(&ro);
   2448 	} else {
   2449 		/*
   2450 		 * If the interface is specified, validate it.
   2451 		 */
   2452 		*ifp = if_get_byindex(mreq.ipv6mr_interface, psref);
   2453 		if (*ifp == NULL)
   2454 			return ENXIO;	/* XXX EINVAL? */
   2455 	}
   2456 	if (sizeof(*ia) == l)
   2457 		memcpy(v, ia, l);
   2458 	else
   2459 		memcpy(v, ia4, l);
   2460 	return 0;
   2461 }
   2462 
   2463 /*
   2464  * Set the IP6 multicast options in response to user setsockopt().
   2465  */
   2466 static int
   2467 ip6_setmoptions(const struct sockopt *sopt, struct in6pcb *in6p)
   2468 {
   2469 	int error = 0;
   2470 	u_int loop, ifindex;
   2471 	struct ipv6_mreq mreq;
   2472 	struct in6_addr ia;
   2473 	struct ifnet *ifp;
   2474 	struct ip6_moptions *im6o = in6p->in6p_moptions;
   2475 	struct in6_multi_mship *imm;
   2476 
   2477 	KASSERT(in6p_locked(in6p));
   2478 
   2479 	if (im6o == NULL) {
   2480 		/*
   2481 		 * No multicast option buffer attached to the pcb;
   2482 		 * allocate one and initialize to default values.
   2483 		 */
   2484 		im6o = malloc(sizeof(*im6o), M_IPMOPTS, M_NOWAIT);
   2485 		if (im6o == NULL)
   2486 			return (ENOBUFS);
   2487 		in6p->in6p_moptions = im6o;
   2488 		im6o->im6o_multicast_if_index = 0;
   2489 		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2490 		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
   2491 		LIST_INIT(&im6o->im6o_memberships);
   2492 	}
   2493 
   2494 	switch (sopt->sopt_name) {
   2495 
   2496 	case IPV6_MULTICAST_IF: {
   2497 		int s;
   2498 		/*
   2499 		 * Select the interface for outgoing multicast packets.
   2500 		 */
   2501 		error = sockopt_get(sopt, &ifindex, sizeof(ifindex));
   2502 		if (error != 0)
   2503 			break;
   2504 
   2505 		s = pserialize_read_enter();
   2506 		if (ifindex != 0) {
   2507 			if ((ifp = if_byindex(ifindex)) == NULL) {
   2508 				pserialize_read_exit(s);
   2509 				error = ENXIO;	/* XXX EINVAL? */
   2510 				break;
   2511 			}
   2512 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
   2513 				pserialize_read_exit(s);
   2514 				error = EADDRNOTAVAIL;
   2515 				break;
   2516 			}
   2517 		} else
   2518 			ifp = NULL;
   2519 		im6o->im6o_multicast_if_index = if_get_index(ifp);
   2520 		pserialize_read_exit(s);
   2521 		break;
   2522 	    }
   2523 
   2524 	case IPV6_MULTICAST_HOPS:
   2525 	    {
   2526 		/*
   2527 		 * Set the IP6 hoplimit for outgoing multicast packets.
   2528 		 */
   2529 		int optval;
   2530 
   2531 		error = sockopt_getint(sopt, &optval);
   2532 		if (error != 0)
   2533 			break;
   2534 
   2535 		if (optval < -1 || optval >= 256)
   2536 			error = EINVAL;
   2537 		else if (optval == -1)
   2538 			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2539 		else
   2540 			im6o->im6o_multicast_hlim = optval;
   2541 		break;
   2542 	    }
   2543 
   2544 	case IPV6_MULTICAST_LOOP:
   2545 		/*
   2546 		 * Set the loopback flag for outgoing multicast packets.
   2547 		 * Must be zero or one.
   2548 		 */
   2549 		error = sockopt_get(sopt, &loop, sizeof(loop));
   2550 		if (error != 0)
   2551 			break;
   2552 		if (loop > 1) {
   2553 			error = EINVAL;
   2554 			break;
   2555 		}
   2556 		im6o->im6o_multicast_loop = loop;
   2557 		break;
   2558 
   2559 	case IPV6_JOIN_GROUP: {
   2560 		int bound;
   2561 		struct psref psref;
   2562 		/*
   2563 		 * Add a multicast group membership.
   2564 		 * Group must be a valid IP6 multicast address.
   2565 		 */
   2566 		bound = curlwp_bind();
   2567 		ifp = NULL;
   2568 		error = ip6_get_membership(sopt, &ifp, &psref, &ia, sizeof(ia));
   2569 		if (error != 0) {
   2570 			KASSERT(ifp == NULL);
   2571 			curlwp_bindx(bound);
   2572 			return error;
   2573 		}
   2574 
   2575 		if (IN6_IS_ADDR_V4MAPPED(&ia)) {
   2576 			error = ip_setmoptions(&in6p->in6p_v4moptions, sopt);
   2577 			goto put_break;
   2578 		}
   2579 		/*
   2580 		 * See if we found an interface, and confirm that it
   2581 		 * supports multicast
   2582 		 */
   2583 		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
   2584 			error = EADDRNOTAVAIL;
   2585 			goto put_break;
   2586 		}
   2587 
   2588 		if (in6_setscope(&ia, ifp, NULL)) {
   2589 			error = EADDRNOTAVAIL; /* XXX: should not happen */
   2590 			goto put_break;
   2591 		}
   2592 
   2593 		/*
   2594 		 * See if the membership already exists.
   2595 		 */
   2596 		LIST_FOREACH(imm, &im6o->im6o_memberships, i6mm_chain) {
   2597 			if (imm->i6mm_maddr->in6m_ifp == ifp &&
   2598 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2599 			    &ia))
   2600 				goto put_break;
   2601 		}
   2602 		if (imm != NULL) {
   2603 			error = EADDRINUSE;
   2604 			goto put_break;
   2605 		}
   2606 		/*
   2607 		 * Everything looks good; add a new record to the multicast
   2608 		 * address list for the given interface.
   2609 		 */
   2610 		IFNET_LOCK(ifp);
   2611 		imm = in6_joingroup(ifp, &ia, &error, 0);
   2612 		IFNET_UNLOCK(ifp);
   2613 		if (imm == NULL)
   2614 			goto put_break;
   2615 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
   2616 	    put_break:
   2617 		if_put(ifp, &psref);
   2618 		curlwp_bindx(bound);
   2619 		break;
   2620 	    }
   2621 
   2622 	case IPV6_LEAVE_GROUP: {
   2623 		struct ifnet *in6m_ifp;
   2624 		/*
   2625 		 * Drop a multicast group membership.
   2626 		 * Group must be a valid IP6 multicast address.
   2627 		 */
   2628 		error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2629 		if (error != 0)
   2630 			break;
   2631 
   2632 		if (IN6_IS_ADDR_V4MAPPED(&mreq.ipv6mr_multiaddr)) {
   2633 			error = ip_setmoptions(&in6p->in6p_v4moptions, sopt);
   2634 			break;
   2635 		}
   2636 		/*
   2637 		 * If an interface address was specified, get a pointer
   2638 		 * to its ifnet structure.
   2639 		 */
   2640 		if (mreq.ipv6mr_interface != 0) {
   2641 			if ((ifp = if_byindex(mreq.ipv6mr_interface)) == NULL) {
   2642 				error = ENXIO;	/* XXX EINVAL? */
   2643 				break;
   2644 			}
   2645 		} else
   2646 			ifp = NULL;
   2647 
   2648 		/* Fill in the scope zone ID */
   2649 		if (ifp) {
   2650 			if (in6_setscope(&mreq.ipv6mr_multiaddr, ifp, NULL)) {
   2651 				/* XXX: should not happen */
   2652 				error = EADDRNOTAVAIL;
   2653 				break;
   2654 			}
   2655 		} else if (mreq.ipv6mr_interface != 0) {
   2656 			/*
   2657 			 * XXX: This case would happens when the (positive)
   2658 			 * index is in the valid range, but the corresponding
   2659 			 * interface has been detached dynamically.  The above
   2660 			 * check probably avoids such case to happen here, but
   2661 			 * we check it explicitly for safety.
   2662 			 */
   2663 			error = EADDRNOTAVAIL;
   2664 			break;
   2665 		} else {	/* ipv6mr_interface == 0 */
   2666 			struct sockaddr_in6 sa6_mc;
   2667 
   2668 			/*
   2669 			 * The API spec says as follows:
   2670 			 *  If the interface index is specified as 0, the
   2671 			 *  system may choose a multicast group membership to
   2672 			 *  drop by matching the multicast address only.
   2673 			 * On the other hand, we cannot disambiguate the scope
   2674 			 * zone unless an interface is provided.  Thus, we
   2675 			 * check if there's ambiguity with the default scope
   2676 			 * zone as the last resort.
   2677 			 */
   2678 			sockaddr_in6_init(&sa6_mc, &mreq.ipv6mr_multiaddr,
   2679 			    0, 0, 0);
   2680 			error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
   2681 			if (error != 0)
   2682 				break;
   2683 			mreq.ipv6mr_multiaddr = sa6_mc.sin6_addr;
   2684 		}
   2685 
   2686 		/*
   2687 		 * Find the membership in the membership list.
   2688 		 */
   2689 		LIST_FOREACH(imm, &im6o->im6o_memberships, i6mm_chain) {
   2690 			if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
   2691 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2692 			    &mreq.ipv6mr_multiaddr))
   2693 				break;
   2694 		}
   2695 		if (imm == NULL) {
   2696 			/* Unable to resolve interface */
   2697 			error = EADDRNOTAVAIL;
   2698 			break;
   2699 		}
   2700 		/*
   2701 		 * Give up the multicast address record to which the
   2702 		 * membership points.
   2703 		 */
   2704 		LIST_REMOVE(imm, i6mm_chain);
   2705 		in6m_ifp = imm->i6mm_maddr->in6m_ifp;
   2706 		IFNET_LOCK(in6m_ifp);
   2707 		in6_leavegroup(imm);
   2708 		/* in6m_ifp should not leave thanks to in6p_lock */
   2709 		IFNET_UNLOCK(in6m_ifp);
   2710 		break;
   2711 	    }
   2712 
   2713 	default:
   2714 		error = EOPNOTSUPP;
   2715 		break;
   2716 	}
   2717 
   2718 	/*
   2719 	 * If all options have default values, no need to keep the mbuf.
   2720 	 */
   2721 	if (im6o->im6o_multicast_if_index == 0 &&
   2722 	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
   2723 	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
   2724 	    LIST_EMPTY(&im6o->im6o_memberships)) {
   2725 		free(in6p->in6p_moptions, M_IPMOPTS);
   2726 		in6p->in6p_moptions = NULL;
   2727 	}
   2728 
   2729 	return (error);
   2730 }
   2731 
   2732 /*
   2733  * Return the IP6 multicast options in response to user getsockopt().
   2734  */
   2735 static int
   2736 ip6_getmoptions(struct sockopt *sopt, struct in6pcb *in6p)
   2737 {
   2738 	u_int optval;
   2739 	int error;
   2740 	struct ip6_moptions *im6o = in6p->in6p_moptions;
   2741 
   2742 	switch (sopt->sopt_name) {
   2743 	case IPV6_MULTICAST_IF:
   2744 		if (im6o == NULL || im6o->im6o_multicast_if_index == 0)
   2745 			optval = 0;
   2746 		else
   2747 			optval = im6o->im6o_multicast_if_index;
   2748 
   2749 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2750 		break;
   2751 
   2752 	case IPV6_MULTICAST_HOPS:
   2753 		if (im6o == NULL)
   2754 			optval = ip6_defmcasthlim;
   2755 		else
   2756 			optval = im6o->im6o_multicast_hlim;
   2757 
   2758 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2759 		break;
   2760 
   2761 	case IPV6_MULTICAST_LOOP:
   2762 		if (im6o == NULL)
   2763 			optval = IPV6_DEFAULT_MULTICAST_LOOP;
   2764 		else
   2765 			optval = im6o->im6o_multicast_loop;
   2766 
   2767 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2768 		break;
   2769 
   2770 	default:
   2771 		error = EOPNOTSUPP;
   2772 	}
   2773 
   2774 	return (error);
   2775 }
   2776 
   2777 /*
   2778  * Discard the IP6 multicast options.
   2779  */
   2780 void
   2781 ip6_freemoptions(struct ip6_moptions *im6o)
   2782 {
   2783 	struct in6_multi_mship *imm, *nimm;
   2784 
   2785 	if (im6o == NULL)
   2786 		return;
   2787 
   2788 	/* The owner of im6o (in6p) should be protected by solock */
   2789 	LIST_FOREACH_SAFE(imm, &im6o->im6o_memberships, i6mm_chain, nimm) {
   2790 		struct ifnet *ifp;
   2791 
   2792 		LIST_REMOVE(imm, i6mm_chain);
   2793 
   2794 		ifp = imm->i6mm_maddr->in6m_ifp;
   2795 		IFNET_LOCK(ifp);
   2796 		in6_leavegroup(imm);
   2797 		/* ifp should not leave thanks to solock */
   2798 		IFNET_UNLOCK(ifp);
   2799 	}
   2800 	free(im6o, M_IPMOPTS);
   2801 }
   2802 
   2803 /*
   2804  * Set IPv6 outgoing packet options based on advanced API.
   2805  */
   2806 int
   2807 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
   2808 	struct ip6_pktopts *stickyopt, kauth_cred_t cred, int uproto)
   2809 {
   2810 	struct cmsghdr *cm = 0;
   2811 
   2812 	if (control == NULL || opt == NULL)
   2813 		return (EINVAL);
   2814 
   2815 	ip6_initpktopts(opt);
   2816 	if (stickyopt) {
   2817 		int error;
   2818 
   2819 		/*
   2820 		 * If stickyopt is provided, make a local copy of the options
   2821 		 * for this particular packet, then override them by ancillary
   2822 		 * objects.
   2823 		 * XXX: copypktopts() does not copy the cached route to a next
   2824 		 * hop (if any).  This is not very good in terms of efficiency,
   2825 		 * but we can allow this since this option should be rarely
   2826 		 * used.
   2827 		 */
   2828 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
   2829 			return (error);
   2830 	}
   2831 
   2832 	/*
   2833 	 * XXX: Currently, we assume all the optional information is stored
   2834 	 * in a single mbuf.
   2835 	 */
   2836 	if (control->m_next)
   2837 		return (EINVAL);
   2838 
   2839 	/* XXX if cm->cmsg_len is not aligned, control->m_len can become <0 */
   2840 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
   2841 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
   2842 		int error;
   2843 
   2844 		if (control->m_len < CMSG_LEN(0))
   2845 			return (EINVAL);
   2846 
   2847 		cm = mtod(control, struct cmsghdr *);
   2848 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
   2849 			return (EINVAL);
   2850 		if (cm->cmsg_level != IPPROTO_IPV6)
   2851 			continue;
   2852 
   2853 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
   2854 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
   2855 		if (error)
   2856 			return (error);
   2857 	}
   2858 
   2859 	return (0);
   2860 }
   2861 
   2862 /*
   2863  * Set a particular packet option, as a sticky option or an ancillary data
   2864  * item.  "len" can be 0 only when it's a sticky option.
   2865  * We have 4 cases of combination of "sticky" and "cmsg":
   2866  * "sticky=0, cmsg=0": impossible
   2867  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
   2868  * "sticky=1, cmsg=0": RFC3542 socket option
   2869  * "sticky=1, cmsg=1": RFC2292 socket option
   2870  */
   2871 static int
   2872 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
   2873     kauth_cred_t cred, int sticky, int cmsg, int uproto)
   2874 {
   2875 	int minmtupolicy;
   2876 	int error;
   2877 
   2878 	if (!sticky && !cmsg) {
   2879 #ifdef DIAGNOSTIC
   2880 		printf("ip6_setpktopt: impossible case\n");
   2881 #endif
   2882 		return (EINVAL);
   2883 	}
   2884 
   2885 	/*
   2886 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
   2887 	 * not be specified in the context of RFC3542.  Conversely,
   2888 	 * RFC3542 types should not be specified in the context of RFC2292.
   2889 	 */
   2890 	if (!cmsg) {
   2891 		switch (optname) {
   2892 		case IPV6_2292PKTINFO:
   2893 		case IPV6_2292HOPLIMIT:
   2894 		case IPV6_2292NEXTHOP:
   2895 		case IPV6_2292HOPOPTS:
   2896 		case IPV6_2292DSTOPTS:
   2897 		case IPV6_2292RTHDR:
   2898 		case IPV6_2292PKTOPTIONS:
   2899 			return (ENOPROTOOPT);
   2900 		}
   2901 	}
   2902 	if (sticky && cmsg) {
   2903 		switch (optname) {
   2904 		case IPV6_PKTINFO:
   2905 		case IPV6_HOPLIMIT:
   2906 		case IPV6_NEXTHOP:
   2907 		case IPV6_HOPOPTS:
   2908 		case IPV6_DSTOPTS:
   2909 		case IPV6_RTHDRDSTOPTS:
   2910 		case IPV6_RTHDR:
   2911 		case IPV6_USE_MIN_MTU:
   2912 		case IPV6_DONTFRAG:
   2913 		case IPV6_OTCLASS:
   2914 		case IPV6_TCLASS:
   2915 		case IPV6_PREFER_TEMPADDR: /* XXX not an RFC3542 option */
   2916 			return (ENOPROTOOPT);
   2917 		}
   2918 	}
   2919 
   2920 	switch (optname) {
   2921 #ifdef RFC2292
   2922 	case IPV6_2292PKTINFO:
   2923 #endif
   2924 	case IPV6_PKTINFO:
   2925 	{
   2926 		struct in6_pktinfo *pktinfo;
   2927 
   2928 		if (len != sizeof(struct in6_pktinfo))
   2929 			return (EINVAL);
   2930 
   2931 		pktinfo = (struct in6_pktinfo *)buf;
   2932 
   2933 		/*
   2934 		 * An application can clear any sticky IPV6_PKTINFO option by
   2935 		 * doing a "regular" setsockopt with ipi6_addr being
   2936 		 * in6addr_any and ipi6_ifindex being zero.
   2937 		 * [RFC 3542, Section 6]
   2938 		 */
   2939 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
   2940 		    pktinfo->ipi6_ifindex == 0 &&
   2941 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2942 			ip6_clearpktopts(opt, optname);
   2943 			break;
   2944 		}
   2945 
   2946 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
   2947 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2948 			return (EINVAL);
   2949 		}
   2950 
   2951 		/* Validate the interface index if specified. */
   2952 		if (pktinfo->ipi6_ifindex) {
   2953 			struct ifnet *ifp;
   2954 			int s = pserialize_read_enter();
   2955 			ifp = if_byindex(pktinfo->ipi6_ifindex);
   2956 			if (ifp == NULL) {
   2957 				pserialize_read_exit(s);
   2958 				return ENXIO;
   2959 			}
   2960 			pserialize_read_exit(s);
   2961 		}
   2962 
   2963 		/*
   2964 		 * We store the address anyway, and let in6_selectsrc()
   2965 		 * validate the specified address.  This is because ipi6_addr
   2966 		 * may not have enough information about its scope zone, and
   2967 		 * we may need additional information (such as outgoing
   2968 		 * interface or the scope zone of a destination address) to
   2969 		 * disambiguate the scope.
   2970 		 * XXX: the delay of the validation may confuse the
   2971 		 * application when it is used as a sticky option.
   2972 		 */
   2973 		if (opt->ip6po_pktinfo == NULL) {
   2974 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
   2975 			    M_IP6OPT, M_NOWAIT);
   2976 			if (opt->ip6po_pktinfo == NULL)
   2977 				return (ENOBUFS);
   2978 		}
   2979 		memcpy(opt->ip6po_pktinfo, pktinfo, sizeof(*pktinfo));
   2980 		break;
   2981 	}
   2982 
   2983 #ifdef RFC2292
   2984 	case IPV6_2292HOPLIMIT:
   2985 #endif
   2986 	case IPV6_HOPLIMIT:
   2987 	{
   2988 		int *hlimp;
   2989 
   2990 		/*
   2991 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
   2992 		 * to simplify the ordering among hoplimit options.
   2993 		 */
   2994 		if (optname == IPV6_HOPLIMIT && sticky)
   2995 			return (ENOPROTOOPT);
   2996 
   2997 		if (len != sizeof(int))
   2998 			return (EINVAL);
   2999 		hlimp = (int *)buf;
   3000 		if (*hlimp < -1 || *hlimp > 255)
   3001 			return (EINVAL);
   3002 
   3003 		opt->ip6po_hlim = *hlimp;
   3004 		break;
   3005 	}
   3006 
   3007 	case IPV6_OTCLASS:
   3008 		if (len != sizeof(u_int8_t))
   3009 			return (EINVAL);
   3010 
   3011 		opt->ip6po_tclass = *(u_int8_t *)buf;
   3012 		break;
   3013 
   3014 	case IPV6_TCLASS:
   3015 	{
   3016 		int tclass;
   3017 
   3018 		if (len != sizeof(int))
   3019 			return (EINVAL);
   3020 		tclass = *(int *)buf;
   3021 		if (tclass < -1 || tclass > 255)
   3022 			return (EINVAL);
   3023 
   3024 		opt->ip6po_tclass = tclass;
   3025 		break;
   3026 	}
   3027 
   3028 #ifdef RFC2292
   3029 	case IPV6_2292NEXTHOP:
   3030 #endif
   3031 	case IPV6_NEXTHOP:
   3032 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3033 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3034 		if (error)
   3035 			return (error);
   3036 
   3037 		if (len == 0) {	/* just remove the option */
   3038 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3039 			break;
   3040 		}
   3041 
   3042 		/* check if cmsg_len is large enough for sa_len */
   3043 		if (len < sizeof(struct sockaddr) || len < *buf)
   3044 			return (EINVAL);
   3045 
   3046 		switch (((struct sockaddr *)buf)->sa_family) {
   3047 		case AF_INET6:
   3048 		{
   3049 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
   3050 
   3051 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
   3052 				return (EINVAL);
   3053 
   3054 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
   3055 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
   3056 				return (EINVAL);
   3057 			}
   3058 			if ((error = sa6_embedscope(sa6, ip6_use_defzone))
   3059 			    != 0) {
   3060 				return (error);
   3061 			}
   3062 			break;
   3063 		}
   3064 		case AF_LINK:	/* eventually be supported? */
   3065 		default:
   3066 			return (EAFNOSUPPORT);
   3067 		}
   3068 
   3069 		/* turn off the previous option, then set the new option. */
   3070 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3071 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
   3072 		if (opt->ip6po_nexthop == NULL)
   3073 			return (ENOBUFS);
   3074 		memcpy(opt->ip6po_nexthop, buf, *buf);
   3075 		break;
   3076 
   3077 #ifdef RFC2292
   3078 	case IPV6_2292HOPOPTS:
   3079 #endif
   3080 	case IPV6_HOPOPTS:
   3081 	{
   3082 		struct ip6_hbh *hbh;
   3083 		int hbhlen;
   3084 
   3085 		/*
   3086 		 * XXX: We don't allow a non-privileged user to set ANY HbH
   3087 		 * options, since per-option restriction has too much
   3088 		 * overhead.
   3089 		 */
   3090 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3091 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3092 		if (error)
   3093 			return (error);
   3094 
   3095 		if (len == 0) {
   3096 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3097 			break;	/* just remove the option */
   3098 		}
   3099 
   3100 		/* message length validation */
   3101 		if (len < sizeof(struct ip6_hbh))
   3102 			return (EINVAL);
   3103 		hbh = (struct ip6_hbh *)buf;
   3104 		hbhlen = (hbh->ip6h_len + 1) << 3;
   3105 		if (len != hbhlen)
   3106 			return (EINVAL);
   3107 
   3108 		/* turn off the previous option, then set the new option. */
   3109 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3110 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
   3111 		if (opt->ip6po_hbh == NULL)
   3112 			return (ENOBUFS);
   3113 		memcpy(opt->ip6po_hbh, hbh, hbhlen);
   3114 
   3115 		break;
   3116 	}
   3117 
   3118 #ifdef RFC2292
   3119 	case IPV6_2292DSTOPTS:
   3120 #endif
   3121 	case IPV6_DSTOPTS:
   3122 	case IPV6_RTHDRDSTOPTS:
   3123 	{
   3124 		struct ip6_dest *dest, **newdest = NULL;
   3125 		int destlen;
   3126 
   3127 		/* XXX: see the comment for IPV6_HOPOPTS */
   3128 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3129 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3130 		if (error)
   3131 			return (error);
   3132 
   3133 		if (len == 0) {
   3134 			ip6_clearpktopts(opt, optname);
   3135 			break;	/* just remove the option */
   3136 		}
   3137 
   3138 		/* message length validation */
   3139 		if (len < sizeof(struct ip6_dest))
   3140 			return (EINVAL);
   3141 		dest = (struct ip6_dest *)buf;
   3142 		destlen = (dest->ip6d_len + 1) << 3;
   3143 		if (len != destlen)
   3144 			return (EINVAL);
   3145 		/*
   3146 		 * Determine the position that the destination options header
   3147 		 * should be inserted; before or after the routing header.
   3148 		 */
   3149 		switch (optname) {
   3150 		case IPV6_2292DSTOPTS:
   3151 			/*
   3152 			 * The old advanced API is ambiguous on this point.
   3153 			 * Our approach is to determine the position based
   3154 			 * according to the existence of a routing header.
   3155 			 * Note, however, that this depends on the order of the
   3156 			 * extension headers in the ancillary data; the 1st
   3157 			 * part of the destination options header must appear
   3158 			 * before the routing header in the ancillary data,
   3159 			 * too.
   3160 			 * RFC3542 solved the ambiguity by introducing
   3161 			 * separate ancillary data or option types.
   3162 			 */
   3163 			if (opt->ip6po_rthdr == NULL)
   3164 				newdest = &opt->ip6po_dest1;
   3165 			else
   3166 				newdest = &opt->ip6po_dest2;
   3167 			break;
   3168 		case IPV6_RTHDRDSTOPTS:
   3169 			newdest = &opt->ip6po_dest1;
   3170 			break;
   3171 		case IPV6_DSTOPTS:
   3172 			newdest = &opt->ip6po_dest2;
   3173 			break;
   3174 		}
   3175 
   3176 		/* turn off the previous option, then set the new option. */
   3177 		ip6_clearpktopts(opt, optname);
   3178 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
   3179 		if (*newdest == NULL)
   3180 			return (ENOBUFS);
   3181 		memcpy(*newdest, dest, destlen);
   3182 
   3183 		break;
   3184 	}
   3185 
   3186 #ifdef RFC2292
   3187 	case IPV6_2292RTHDR:
   3188 #endif
   3189 	case IPV6_RTHDR:
   3190 	{
   3191 		struct ip6_rthdr *rth;
   3192 		int rthlen;
   3193 
   3194 		if (len == 0) {
   3195 			ip6_clearpktopts(opt, IPV6_RTHDR);
   3196 			break;	/* just remove the option */
   3197 		}
   3198 
   3199 		/* message length validation */
   3200 		if (len < sizeof(struct ip6_rthdr))
   3201 			return (EINVAL);
   3202 		rth = (struct ip6_rthdr *)buf;
   3203 		rthlen = (rth->ip6r_len + 1) << 3;
   3204 		if (len != rthlen)
   3205 			return (EINVAL);
   3206 		switch (rth->ip6r_type) {
   3207 		case IPV6_RTHDR_TYPE_0:
   3208 			if (rth->ip6r_len == 0)	/* must contain one addr */
   3209 				return (EINVAL);
   3210 			if (rth->ip6r_len % 2) /* length must be even */
   3211 				return (EINVAL);
   3212 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
   3213 				return (EINVAL);
   3214 			break;
   3215 		default:
   3216 			return (EINVAL);	/* not supported */
   3217 		}
   3218 		/* turn off the previous option */
   3219 		ip6_clearpktopts(opt, IPV6_RTHDR);
   3220 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
   3221 		if (opt->ip6po_rthdr == NULL)
   3222 			return (ENOBUFS);
   3223 		memcpy(opt->ip6po_rthdr, rth, rthlen);
   3224 		break;
   3225 	}
   3226 
   3227 	case IPV6_USE_MIN_MTU:
   3228 		if (len != sizeof(int))
   3229 			return (EINVAL);
   3230 		minmtupolicy = *(int *)buf;
   3231 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
   3232 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
   3233 		    minmtupolicy != IP6PO_MINMTU_ALL) {
   3234 			return (EINVAL);
   3235 		}
   3236 		opt->ip6po_minmtu = minmtupolicy;
   3237 		break;
   3238 
   3239 	case IPV6_DONTFRAG:
   3240 		if (len != sizeof(int))
   3241 			return (EINVAL);
   3242 
   3243 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
   3244 			/*
   3245 			 * we ignore this option for TCP sockets.
   3246 			 * (RFC3542 leaves this case unspecified.)
   3247 			 */
   3248 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
   3249 		} else
   3250 			opt->ip6po_flags |= IP6PO_DONTFRAG;
   3251 		break;
   3252 
   3253 	case IPV6_PREFER_TEMPADDR:
   3254 	{
   3255 		int preftemp;
   3256 
   3257 		if (len != sizeof(int))
   3258 			return (EINVAL);
   3259 		preftemp = *(int *)buf;
   3260 		switch (preftemp) {
   3261 		case IP6PO_TEMPADDR_SYSTEM:
   3262 		case IP6PO_TEMPADDR_NOTPREFER:
   3263 		case IP6PO_TEMPADDR_PREFER:
   3264 			break;
   3265 		default:
   3266 			return (EINVAL);
   3267 		}
   3268 		opt->ip6po_prefer_tempaddr = preftemp;
   3269 		break;
   3270 	}
   3271 
   3272 	default:
   3273 		return (ENOPROTOOPT);
   3274 	} /* end of switch */
   3275 
   3276 	return (0);
   3277 }
   3278 
   3279 /*
   3280  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
   3281  * packet to the input queue of a specified interface.  Note that this
   3282  * calls the output routine of the loopback "driver", but with an interface
   3283  * pointer that might NOT be lo0ifp -- easier than replicating that code here.
   3284  */
   3285 void
   3286 ip6_mloopback(struct ifnet *ifp, struct mbuf *m,
   3287 	const struct sockaddr_in6 *dst)
   3288 {
   3289 	struct mbuf *copym;
   3290 	struct ip6_hdr *ip6;
   3291 
   3292 	copym = m_copy(m, 0, M_COPYALL);
   3293 	if (copym == NULL)
   3294 		return;
   3295 
   3296 	/*
   3297 	 * Make sure to deep-copy IPv6 header portion in case the data
   3298 	 * is in an mbuf cluster, so that we can safely override the IPv6
   3299 	 * header portion later.
   3300 	 */
   3301 	if ((copym->m_flags & M_EXT) != 0 ||
   3302 	    copym->m_len < sizeof(struct ip6_hdr)) {
   3303 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
   3304 		if (copym == NULL)
   3305 			return;
   3306 	}
   3307 
   3308 #ifdef DIAGNOSTIC
   3309 	if (copym->m_len < sizeof(*ip6)) {
   3310 		m_freem(copym);
   3311 		return;
   3312 	}
   3313 #endif
   3314 
   3315 	ip6 = mtod(copym, struct ip6_hdr *);
   3316 	/*
   3317 	 * clear embedded scope identifiers if necessary.
   3318 	 * in6_clearscope will touch the addresses only when necessary.
   3319 	 */
   3320 	in6_clearscope(&ip6->ip6_src);
   3321 	in6_clearscope(&ip6->ip6_dst);
   3322 
   3323 	(void)looutput(ifp, copym, (const struct sockaddr *)dst, NULL);
   3324 }
   3325 
   3326 /*
   3327  * Chop IPv6 header off from the payload.
   3328  */
   3329 static int
   3330 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
   3331 {
   3332 	struct mbuf *mh;
   3333 	struct ip6_hdr *ip6;
   3334 
   3335 	ip6 = mtod(m, struct ip6_hdr *);
   3336 	if (m->m_len > sizeof(*ip6)) {
   3337 		MGETHDR(mh, M_DONTWAIT, MT_HEADER);
   3338 		if (mh == NULL) {
   3339 			m_freem(m);
   3340 			return ENOBUFS;
   3341 		}
   3342 		M_MOVE_PKTHDR(mh, m);
   3343 		MH_ALIGN(mh, sizeof(*ip6));
   3344 		m->m_len -= sizeof(*ip6);
   3345 		m->m_data += sizeof(*ip6);
   3346 		mh->m_next = m;
   3347 		mh->m_len = sizeof(*ip6);
   3348 		memcpy(mtod(mh, void *), (void *)ip6, sizeof(*ip6));
   3349 		m = mh;
   3350 	}
   3351 	exthdrs->ip6e_ip6 = m;
   3352 	return 0;
   3353 }
   3354 
   3355 /*
   3356  * Compute IPv6 extension header length.
   3357  */
   3358 int
   3359 ip6_optlen(struct in6pcb *in6p)
   3360 {
   3361 	int len;
   3362 
   3363 	if (!in6p->in6p_outputopts)
   3364 		return 0;
   3365 
   3366 	len = 0;
   3367 #define elen(x) \
   3368     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
   3369 
   3370 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
   3371 	len += elen(in6p->in6p_outputopts->ip6po_dest1);
   3372 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
   3373 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
   3374 	return len;
   3375 #undef elen
   3376 }
   3377 
   3378 /*
   3379  * Ensure sending address is valid.
   3380  * Returns 0 on success, -1 if an error should be sent back or 1
   3381  * if the packet could be dropped without error (protocol dependent).
   3382  */
   3383 static int
   3384 ip6_ifaddrvalid(const struct in6_addr *src, const struct in6_addr *dst)
   3385 {
   3386 	struct sockaddr_in6 sin6;
   3387 	int s, error;
   3388 	struct ifaddr *ifa;
   3389 	struct in6_ifaddr *ia6;
   3390 
   3391 	if (IN6_IS_ADDR_UNSPECIFIED(src))
   3392 		return 0;
   3393 
   3394 	memset(&sin6, 0, sizeof(sin6));
   3395 	sin6.sin6_family = AF_INET6;
   3396 	sin6.sin6_len = sizeof(sin6);
   3397 	sin6.sin6_addr = *src;
   3398 
   3399 	s = pserialize_read_enter();
   3400 	ifa = ifa_ifwithaddr(sin6tosa(&sin6));
   3401 	if ((ia6 = ifatoia6(ifa)) == NULL ||
   3402 	    ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_DUPLICATED))
   3403 		error = -1;
   3404 	else if (ia6->ia6_flags & IN6_IFF_TENTATIVE)
   3405 		error = 1;
   3406 	else if (ia6->ia6_flags & IN6_IFF_DETACHED &&
   3407 	    (sin6.sin6_addr = *dst, ifa_ifwithaddr(sin6tosa(&sin6)) == NULL))
   3408 		/* Allow internal traffic to DETACHED addresses */
   3409 		error = 1;
   3410 	else
   3411 		error = 0;
   3412 	pserialize_read_exit(s);
   3413 
   3414 	return error;
   3415 }
   3416