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ip6_output.c revision 1.150.2.4
      1 /*	$NetBSD: ip6_output.c,v 1.150.2.4 2017/12/03 11:39:04 jdolecek 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 1.150.2.4 2017/12/03 11:39:04 jdolecek 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 #include <netipsec/xform.h>
    108 #endif
    109 
    110 
    111 #include <net/net_osdep.h>
    112 
    113 extern pfil_head_t *inet6_pfil_hook;	/* XXX */
    114 
    115 struct ip6_exthdrs {
    116 	struct mbuf *ip6e_ip6;
    117 	struct mbuf *ip6e_hbh;
    118 	struct mbuf *ip6e_dest1;
    119 	struct mbuf *ip6e_rthdr;
    120 	struct mbuf *ip6e_dest2;
    121 };
    122 
    123 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
    124 	kauth_cred_t, int);
    125 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
    126 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *, kauth_cred_t,
    127 	int, int, int);
    128 static int ip6_setmoptions(const struct sockopt *, struct in6pcb *);
    129 static int ip6_getmoptions(struct sockopt *, struct in6pcb *);
    130 static int ip6_copyexthdr(struct mbuf **, void *, int);
    131 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
    132 	struct ip6_frag **);
    133 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
    134 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
    135 static int ip6_getpmtu(struct rtentry *, struct ifnet *, u_long *, int *);
    136 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
    137 static int ip6_ifaddrvalid(const struct in6_addr *, const struct in6_addr *);
    138 static int ip6_handle_rthdr(struct ip6_rthdr *, struct ip6_hdr *);
    139 
    140 #ifdef RFC2292
    141 static int ip6_pcbopts(struct ip6_pktopts **, struct socket *, struct sockopt *);
    142 #endif
    143 
    144 static int
    145 ip6_handle_rthdr(struct ip6_rthdr *rh, struct ip6_hdr *ip6)
    146 {
    147 	struct ip6_rthdr0 *rh0;
    148 	struct in6_addr *addr;
    149 	struct sockaddr_in6 sa;
    150 	int error = 0;
    151 
    152 	switch (rh->ip6r_type) {
    153 	case IPV6_RTHDR_TYPE_0:
    154 		 rh0 = (struct ip6_rthdr0 *)rh;
    155 		 addr = (struct in6_addr *)(rh0 + 1);
    156 
    157 		 /*
    158 		  * construct a sockaddr_in6 form of the first hop.
    159 		  *
    160 		  * XXX we may not have enough information about its scope zone;
    161 		  * there is no standard API to pass the information from the
    162 		  * application.
    163 		  */
    164 		 sockaddr_in6_init(&sa, addr, 0, 0, 0);
    165 		 error = sa6_embedscope(&sa, ip6_use_defzone);
    166 		 if (error != 0)
    167 			 break;
    168 		 (void)memmove(&addr[0], &addr[1],
    169 		     sizeof(struct in6_addr) * (rh0->ip6r0_segleft - 1));
    170 		 addr[rh0->ip6r0_segleft - 1] = ip6->ip6_dst;
    171 		 ip6->ip6_dst = sa.sin6_addr;
    172 		 /* XXX */
    173 		 in6_clearscope(addr + rh0->ip6r0_segleft - 1);
    174 		 break;
    175 	default:	/* is it possible? */
    176 		 error = EINVAL;
    177 	}
    178 
    179 	return error;
    180 }
    181 
    182 /*
    183  * Send an IP packet to a host.
    184  */
    185 int
    186 ip6_if_output(struct ifnet * const ifp, struct ifnet * const origifp,
    187     struct mbuf * const m,
    188     const struct sockaddr_in6 * const dst, const struct rtentry *rt)
    189 {
    190 	int error = 0;
    191 
    192 	if (rt != NULL) {
    193 		error = rt_check_reject_route(rt, ifp);
    194 		if (error != 0) {
    195 			m_freem(m);
    196 			return error;
    197 		}
    198 	}
    199 
    200 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
    201 		error = if_output_lock(ifp, origifp, m, sin6tocsa(dst), rt);
    202 	else
    203 		error = if_output_lock(ifp, ifp, m, sin6tocsa(dst), rt);
    204 	return error;
    205 }
    206 
    207 /*
    208  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
    209  * header (with pri, len, nxt, hlim, src, dst).
    210  * This function may modify ver and hlim only.
    211  * The mbuf chain containing the packet will be freed.
    212  * The mbuf opt, if present, will not be freed.
    213  *
    214  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
    215  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
    216  * which is rt_rmx.rmx_mtu.
    217  */
    218 int
    219 ip6_output(
    220     struct mbuf *m0,
    221     struct ip6_pktopts *opt,
    222     struct route *ro,
    223     int flags,
    224     struct ip6_moptions *im6o,
    225     struct in6pcb *in6p,
    226     struct ifnet **ifpp		/* XXX: just for statistics */
    227 )
    228 {
    229 	struct ip6_hdr *ip6, *mhip6;
    230 	struct ifnet *ifp = NULL, *origifp = NULL;
    231 	struct mbuf *m = m0;
    232 	int hlen, tlen, len, off;
    233 	bool tso;
    234 	struct route ip6route;
    235 	struct rtentry *rt = NULL, *rt_pmtu;
    236 	const struct sockaddr_in6 *dst;
    237 	struct sockaddr_in6 src_sa, dst_sa;
    238 	int error = 0;
    239 	struct in6_ifaddr *ia = NULL;
    240 	u_long mtu;
    241 	int alwaysfrag, dontfrag;
    242 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
    243 	struct ip6_exthdrs exthdrs;
    244 	struct in6_addr finaldst, src0, dst0;
    245 	u_int32_t zone;
    246 	struct route *ro_pmtu = NULL;
    247 	int hdrsplit = 0;
    248 	int needipsec = 0;
    249 #ifdef IPSEC
    250 	struct secpolicy *sp = NULL;
    251 #endif
    252 	struct psref psref, psref_ia;
    253 	int bound = curlwp_bind();
    254 	bool release_psref_ia = false;
    255 
    256 #ifdef  DIAGNOSTIC
    257 	if ((m->m_flags & M_PKTHDR) == 0)
    258 		panic("ip6_output: no HDR");
    259 
    260 	if ((m->m_pkthdr.csum_flags &
    261 	    (M_CSUM_TCPv4|M_CSUM_UDPv4|M_CSUM_TSOv4)) != 0) {
    262 		panic("ip6_output: IPv4 checksum offload flags: %d",
    263 		    m->m_pkthdr.csum_flags);
    264 	}
    265 
    266 	if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) ==
    267 	    (M_CSUM_TCPv6|M_CSUM_UDPv6)) {
    268 		panic("ip6_output: conflicting checksum offload flags: %d",
    269 		    m->m_pkthdr.csum_flags);
    270 	}
    271 #endif
    272 
    273 	M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data, sizeof(struct ip6_hdr));
    274 
    275 #define MAKE_EXTHDR(hp, mp)						\
    276     do {								\
    277 	if (hp) {							\
    278 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
    279 		error = ip6_copyexthdr((mp), (void *)(hp), 		\
    280 		    ((eh)->ip6e_len + 1) << 3);				\
    281 		if (error)						\
    282 			goto freehdrs;					\
    283 	}								\
    284     } while (/*CONSTCOND*/ 0)
    285 
    286 	memset(&exthdrs, 0, sizeof(exthdrs));
    287 	if (opt) {
    288 		/* Hop-by-Hop options header */
    289 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
    290 		/* Destination options header(1st part) */
    291 		MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
    292 		/* Routing header */
    293 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
    294 		/* Destination options header(2nd part) */
    295 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
    296 	}
    297 
    298 	/*
    299 	 * Calculate the total length of the extension header chain.
    300 	 * Keep the length of the unfragmentable part for fragmentation.
    301 	 */
    302 	optlen = 0;
    303 	if (exthdrs.ip6e_hbh) optlen += exthdrs.ip6e_hbh->m_len;
    304 	if (exthdrs.ip6e_dest1) optlen += exthdrs.ip6e_dest1->m_len;
    305 	if (exthdrs.ip6e_rthdr) 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) optlen += exthdrs.ip6e_dest2->m_len;
    309 
    310 #ifdef IPSEC
    311 	if (ipsec_used) {
    312 		/* Check the security policy (SP) for the packet */
    313 
    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 /* IPSEC */
    328 
    329 
    330 	if (needipsec &&
    331 	    (m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    332 		in6_delayed_cksum(m);
    333 		m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    334 	}
    335 
    336 
    337 	/*
    338 	 * If we need IPsec, or there is at least one extension header,
    339 	 * separate IP6 header from the payload.
    340 	 */
    341 	if ((needipsec || optlen) && !hdrsplit) {
    342 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    343 			m = NULL;
    344 			goto freehdrs;
    345 		}
    346 		m = exthdrs.ip6e_ip6;
    347 		hdrsplit++;
    348 	}
    349 
    350 	/* adjust pointer */
    351 	ip6 = mtod(m, struct ip6_hdr *);
    352 
    353 	/* adjust mbuf packet header length */
    354 	m->m_pkthdr.len += optlen;
    355 	plen = m->m_pkthdr.len - sizeof(*ip6);
    356 
    357 	/* If this is a jumbo payload, insert a jumbo payload option. */
    358 	if (plen > IPV6_MAXPACKET) {
    359 		if (!hdrsplit) {
    360 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    361 				m = NULL;
    362 				goto freehdrs;
    363 			}
    364 			m = exthdrs.ip6e_ip6;
    365 			hdrsplit++;
    366 		}
    367 		/* adjust pointer */
    368 		ip6 = mtod(m, struct ip6_hdr *);
    369 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
    370 			goto freehdrs;
    371 		optlen += 8; /* XXX JUMBOOPTLEN */
    372 		ip6->ip6_plen = 0;
    373 	} else
    374 		ip6->ip6_plen = htons(plen);
    375 
    376 	/*
    377 	 * Concatenate headers and fill in next header fields.
    378 	 * Here we have, on "m"
    379 	 *	IPv6 payload
    380 	 * and we insert headers accordingly.  Finally, we should be getting:
    381 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
    382 	 *
    383 	 * during the header composing process, "m" points to IPv6 header.
    384 	 * "mprev" points to an extension header prior to esp.
    385 	 */
    386 	{
    387 		u_char *nexthdrp = &ip6->ip6_nxt;
    388 		struct mbuf *mprev = m;
    389 
    390 		/*
    391 		 * we treat dest2 specially.  this makes IPsec processing
    392 		 * much easier.  the goal here is to make mprev point the
    393 		 * mbuf prior to dest2.
    394 		 *
    395 		 * result: IPv6 dest2 payload
    396 		 * m and mprev will point to IPv6 header.
    397 		 */
    398 		if (exthdrs.ip6e_dest2) {
    399 			if (!hdrsplit)
    400 				panic("assumption failed: hdr not split");
    401 			exthdrs.ip6e_dest2->m_next = m->m_next;
    402 			m->m_next = exthdrs.ip6e_dest2;
    403 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
    404 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
    405 		}
    406 
    407 #define MAKE_CHAIN(m, mp, p, i)\
    408     do {\
    409 	if (m) {\
    410 		if (!hdrsplit) \
    411 			panic("assumption failed: hdr not split"); \
    412 		*mtod((m), u_char *) = *(p);\
    413 		*(p) = (i);\
    414 		p = mtod((m), u_char *);\
    415 		(m)->m_next = (mp)->m_next;\
    416 		(mp)->m_next = (m);\
    417 		(mp) = (m);\
    418 	}\
    419     } while (/*CONSTCOND*/ 0)
    420 		/*
    421 		 * result: IPv6 hbh dest1 rthdr dest2 payload
    422 		 * m will point to IPv6 header.  mprev will point to the
    423 		 * extension header prior to dest2 (rthdr in the above case).
    424 		 */
    425 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
    426 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
    427 		    IPPROTO_DSTOPTS);
    428 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
    429 		    IPPROTO_ROUTING);
    430 
    431 		M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data,
    432 		    sizeof(struct ip6_hdr) + optlen);
    433 	}
    434 
    435 	/* Need to save for pmtu */
    436 	finaldst = ip6->ip6_dst;
    437 
    438 	/*
    439 	 * If there is a routing header, replace destination address field
    440 	 * with the first hop of the routing header.
    441 	 */
    442 	if (exthdrs.ip6e_rthdr) {
    443 		struct ip6_rthdr *rh;
    444 
    445 		rh = (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
    446 		    struct ip6_rthdr *));
    447 
    448 		error = ip6_handle_rthdr(rh, ip6);
    449 		if (error != 0)
    450 			goto bad;
    451 	}
    452 
    453 	/* Source address validation */
    454 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
    455 	    (flags & IPV6_UNSPECSRC) == 0) {
    456 		error = EOPNOTSUPP;
    457 		IP6_STATINC(IP6_STAT_BADSCOPE);
    458 		goto bad;
    459 	}
    460 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
    461 		error = EOPNOTSUPP;
    462 		IP6_STATINC(IP6_STAT_BADSCOPE);
    463 		goto bad;
    464 	}
    465 
    466 	IP6_STATINC(IP6_STAT_LOCALOUT);
    467 
    468 	/*
    469 	 * Route packet.
    470 	 */
    471 	/* initialize cached route */
    472 	if (ro == NULL) {
    473 		memset(&ip6route, 0, sizeof(ip6route));
    474 		ro = &ip6route;
    475 	}
    476 	ro_pmtu = ro;
    477 	if (opt && opt->ip6po_rthdr)
    478 		ro = &opt->ip6po_route;
    479 
    480  	/*
    481 	 * if specified, try to fill in the traffic class field.
    482 	 * do not override if a non-zero value is already set.
    483 	 * we check the diffserv field and the ecn field separately.
    484 	 */
    485 	if (opt && opt->ip6po_tclass >= 0) {
    486 		int mask = 0;
    487 
    488 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
    489 			mask |= 0xfc;
    490 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
    491 			mask |= 0x03;
    492 		if (mask != 0)
    493 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
    494 	}
    495 
    496 	/* fill in or override the hop limit field, if necessary. */
    497 	if (opt && opt->ip6po_hlim != -1)
    498 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
    499 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    500 		if (im6o != NULL)
    501 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
    502 		else
    503 			ip6->ip6_hlim = ip6_defmcasthlim;
    504 	}
    505 
    506 #ifdef IPSEC
    507 	if (needipsec) {
    508 		int s = splsoftnet();
    509 		error = ipsec6_process_packet(m, sp->req);
    510 
    511 		/*
    512 		 * Preserve KAME behaviour: ENOENT can be returned
    513 		 * when an SA acquire is in progress.  Don't propagate
    514 		 * this to user-level; it confuses applications.
    515 		 * XXX this will go away when the SADB is redone.
    516 		 */
    517 		if (error == ENOENT)
    518 			error = 0;
    519 		splx(s);
    520 		goto done;
    521 	}
    522 #endif /* IPSEC */
    523 
    524 	/* adjust pointer */
    525 	ip6 = mtod(m, struct ip6_hdr *);
    526 
    527 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    528 
    529 	/* We do not need a route for multicast */
    530 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    531 		struct in6_pktinfo *pi = NULL;
    532 
    533 		/*
    534 		 * If the outgoing interface for the address is specified by
    535 		 * the caller, use it.
    536 		 */
    537 		if (opt && (pi = opt->ip6po_pktinfo) != NULL) {
    538 			/* XXX boundary check is assumed to be already done. */
    539 			ifp = if_get_byindex(pi->ipi6_ifindex, &psref);
    540 		} else if (im6o != NULL) {
    541 			ifp = if_get_byindex(im6o->im6o_multicast_if_index,
    542 			    &psref);
    543 		}
    544 	}
    545 
    546 	if (ifp == NULL) {
    547 		error = in6_selectroute(&dst_sa, opt, &ro, &rt, true);
    548 		if (error != 0)
    549 			goto bad;
    550 		ifp = if_get_byindex(rt->rt_ifp->if_index, &psref);
    551 	}
    552 
    553 	if (rt == NULL) {
    554 		/*
    555 		 * If in6_selectroute() does not return a route entry,
    556 		 * dst may not have been updated.
    557 		 */
    558 		error = rtcache_setdst(ro, sin6tosa(&dst_sa));
    559 		if (error) {
    560 			goto bad;
    561 		}
    562 	}
    563 
    564 	/*
    565 	 * then rt (for unicast) and ifp must be non-NULL valid values.
    566 	 */
    567 	if ((flags & IPV6_FORWARDING) == 0) {
    568 		/* XXX: the FORWARDING flag can be set for mrouting. */
    569 		in6_ifstat_inc(ifp, ifs6_out_request);
    570 	}
    571 	if (rt != NULL) {
    572 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
    573 		rt->rt_use++;
    574 	}
    575 
    576 	/*
    577 	 * The outgoing interface must be in the zone of source and
    578 	 * destination addresses.  We should use ia_ifp to support the
    579 	 * case of sending packets to an address of our own.
    580 	 */
    581 	if (ia != NULL && ia->ia_ifp) {
    582 		origifp = ia->ia_ifp;
    583 		if (if_is_deactivated(origifp))
    584 			goto bad;
    585 		if_acquire(origifp, &psref_ia);
    586 		release_psref_ia = true;
    587 	} else
    588 		origifp = ifp;
    589 
    590 	src0 = ip6->ip6_src;
    591 	if (in6_setscope(&src0, origifp, &zone))
    592 		goto badscope;
    593 	sockaddr_in6_init(&src_sa, &ip6->ip6_src, 0, 0, 0);
    594 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
    595 		goto badscope;
    596 
    597 	dst0 = ip6->ip6_dst;
    598 	if (in6_setscope(&dst0, origifp, &zone))
    599 		goto badscope;
    600 	/* re-initialize to be sure */
    601 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    602 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id)
    603 		goto badscope;
    604 
    605 	/* scope check is done. */
    606 
    607 	/* Ensure we only send from a valid address. */
    608 	if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
    609 	    (error = ip6_ifaddrvalid(&src0, &dst0)) != 0)
    610 	{
    611 		char ip6buf[INET6_ADDRSTRLEN];
    612 		nd6log(LOG_ERR,
    613 		    "refusing to send from invalid address %s (pid %d)\n",
    614 		    IN6_PRINT(ip6buf, &src0), curproc->p_pid);
    615 		IP6_STATINC(IP6_STAT_ODROPPED);
    616 		in6_ifstat_inc(origifp, ifs6_out_discard);
    617 		if (error == 1)
    618 			/*
    619 			 * Address exists, but is tentative or detached.
    620 			 * We can't send from it because it's invalid,
    621 			 * so we drop the packet.
    622 			 */
    623 			error = 0;
    624 		else
    625 			error = EADDRNOTAVAIL;
    626 		goto bad;
    627 	}
    628 
    629 	if (rt != NULL && (rt->rt_flags & RTF_GATEWAY) &&
    630 	    !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
    631 		dst = satocsin6(rt->rt_gateway);
    632 	else
    633 		dst = satocsin6(rtcache_getdst(ro));
    634 
    635 	/*
    636 	 * XXXXXX: original code follows:
    637 	 */
    638 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
    639 		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
    640 	else {
    641 		bool ingroup;
    642 
    643 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
    644 
    645 		in6_ifstat_inc(ifp, ifs6_out_mcast);
    646 
    647 		/*
    648 		 * Confirm that the outgoing interface supports multicast.
    649 		 */
    650 		if (!(ifp->if_flags & IFF_MULTICAST)) {
    651 			IP6_STATINC(IP6_STAT_NOROUTE);
    652 			in6_ifstat_inc(ifp, ifs6_out_discard);
    653 			error = ENETUNREACH;
    654 			goto bad;
    655 		}
    656 
    657 		ingroup = in6_multi_group(&ip6->ip6_dst, ifp);
    658 		if (ingroup && (im6o == NULL || im6o->im6o_multicast_loop)) {
    659 			/*
    660 			 * If we belong to the destination multicast group
    661 			 * on the outgoing interface, and the caller did not
    662 			 * forbid loopback, loop back a copy.
    663 			 */
    664 			KASSERT(dst != NULL);
    665 			ip6_mloopback(ifp, m, dst);
    666 		} else {
    667 			/*
    668 			 * If we are acting as a multicast router, perform
    669 			 * multicast forwarding as if the packet had just
    670 			 * arrived on the interface to which we are about
    671 			 * to send.  The multicast forwarding function
    672 			 * recursively calls this function, using the
    673 			 * IPV6_FORWARDING flag to prevent infinite recursion.
    674 			 *
    675 			 * Multicasts that are looped back by ip6_mloopback(),
    676 			 * above, will be forwarded by the ip6_input() routine,
    677 			 * if necessary.
    678 			 */
    679 			if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
    680 				if (ip6_mforward(ip6, ifp, m) != 0) {
    681 					m_freem(m);
    682 					goto done;
    683 				}
    684 			}
    685 		}
    686 		/*
    687 		 * Multicasts with a hoplimit of zero may be looped back,
    688 		 * above, but must not be transmitted on a network.
    689 		 * Also, multicasts addressed to the loopback interface
    690 		 * are not sent -- the above call to ip6_mloopback() will
    691 		 * loop back a copy if this host actually belongs to the
    692 		 * destination group on the loopback interface.
    693 		 */
    694 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
    695 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
    696 			m_freem(m);
    697 			goto done;
    698 		}
    699 	}
    700 
    701 	/*
    702 	 * Fill the outgoing inteface to tell the upper layer
    703 	 * to increment per-interface statistics.
    704 	 */
    705 	if (ifpp)
    706 		*ifpp = ifp;
    707 
    708 	/* Determine path MTU. */
    709 	/*
    710 	 * ro_pmtu represent final destination while
    711 	 * ro might represent immediate destination.
    712 	 * Use ro_pmtu destination since MTU might differ.
    713 	 */
    714 	if (ro_pmtu != ro) {
    715 		union {
    716 			struct sockaddr		dst;
    717 			struct sockaddr_in6	dst6;
    718 		} u;
    719 
    720 		/* ro_pmtu may not have a cache */
    721 		sockaddr_in6_init(&u.dst6, &finaldst, 0, 0, 0);
    722 		rt_pmtu = rtcache_lookup(ro_pmtu, &u.dst);
    723 	} else
    724 		rt_pmtu = rt;
    725 	error = ip6_getpmtu(rt_pmtu, ifp, &mtu, &alwaysfrag);
    726 	if (rt_pmtu != NULL && rt_pmtu != rt)
    727 		rtcache_unref(rt_pmtu, ro_pmtu);
    728 	if (error != 0)
    729 		goto bad;
    730 
    731 	/*
    732 	 * The caller of this function may specify to use the minimum MTU
    733 	 * in some cases.
    734 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
    735 	 * setting.  The logic is a bit complicated; by default, unicast
    736 	 * packets will follow path MTU while multicast packets will be sent at
    737 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
    738 	 * including unicast ones will be sent at the minimum MTU.  Multicast
    739 	 * packets will always be sent at the minimum MTU unless
    740 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
    741 	 * See RFC 3542 for more details.
    742 	 */
    743 	if (mtu > IPV6_MMTU) {
    744 		if ((flags & IPV6_MINMTU))
    745 			mtu = IPV6_MMTU;
    746 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
    747 			mtu = IPV6_MMTU;
    748 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
    749 			 (opt == NULL ||
    750 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
    751 			mtu = IPV6_MMTU;
    752 		}
    753 	}
    754 
    755 	/*
    756 	 * clear embedded scope identifiers if necessary.
    757 	 * in6_clearscope will touch the addresses only when necessary.
    758 	 */
    759 	in6_clearscope(&ip6->ip6_src);
    760 	in6_clearscope(&ip6->ip6_dst);
    761 
    762 	/*
    763 	 * If the outgoing packet contains a hop-by-hop options header,
    764 	 * it must be examined and processed even by the source node.
    765 	 * (RFC 2460, section 4.)
    766 	 */
    767 	if (ip6->ip6_nxt == IPV6_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;/* better error? */
    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 		struct mbuf **mnext, *m_frgpart;
    900 		struct ip6_frag *ip6f;
    901 		u_int32_t id = htonl(ip6_randomid());
    902 		u_char nextproto;
    903 #if 0				/* see below */
    904 		struct ip6ctlparam ip6cp;
    905 		u_int32_t mtu32;
    906 #endif
    907 
    908 		/*
    909 		 * Too large for the destination or interface;
    910 		 * fragment if possible.
    911 		 * Must be able to put at least 8 bytes per fragment.
    912 		 */
    913 		hlen = unfragpartlen;
    914 		if (mtu > IPV6_MAXPACKET)
    915 			mtu = IPV6_MAXPACKET;
    916 
    917 #if 0
    918 		/*
    919 		 * It is believed this code is a leftover from the
    920 		 * development of the IPV6_RECVPATHMTU sockopt and
    921 		 * associated work to implement RFC3542.
    922 		 * It's not entirely clear what the intent of the API
    923 		 * is at this point, so disable this code for now.
    924 		 * The IPV6_RECVPATHMTU sockopt and/or IPV6_DONTFRAG
    925 		 * will send notifications if the application requests.
    926 		 */
    927 
    928 		/* Notify a proper path MTU to applications. */
    929 		mtu32 = (u_int32_t)mtu;
    930 		memset(&ip6cp, 0, sizeof(ip6cp));
    931 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
    932 		pfctlinput2(PRC_MSGSIZE,
    933 		    rtcache_getdst(ro_pmtu), &ip6cp);
    934 #endif
    935 
    936 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
    937 		if (len < 8) {
    938 			error = EMSGSIZE;
    939 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
    940 			goto bad;
    941 		}
    942 
    943 		mnext = &m->m_nextpkt;
    944 
    945 		/*
    946 		 * Change the next header field of the last header in the
    947 		 * unfragmentable part.
    948 		 */
    949 		if (exthdrs.ip6e_rthdr) {
    950 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
    951 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
    952 		} else if (exthdrs.ip6e_dest1) {
    953 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
    954 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
    955 		} else if (exthdrs.ip6e_hbh) {
    956 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
    957 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
    958 		} else {
    959 			nextproto = ip6->ip6_nxt;
    960 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
    961 		}
    962 
    963 		if ((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6))
    964 		    != 0) {
    965 			if (IN6_NEED_CHECKSUM(ifp,
    966 			    m->m_pkthdr.csum_flags &
    967 			    (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
    968 				in6_delayed_cksum(m);
    969 			}
    970 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    971 		}
    972 
    973 		/*
    974 		 * Loop through length of segment after first fragment,
    975 		 * make new header and copy data of each part and link onto
    976 		 * chain.
    977 		 */
    978 		m0 = m;
    979 		for (off = hlen; off < tlen; off += len) {
    980 			struct mbuf *mlast;
    981 
    982 			MGETHDR(m, M_DONTWAIT, MT_HEADER);
    983 			if (!m) {
    984 				error = ENOBUFS;
    985 				IP6_STATINC(IP6_STAT_ODROPPED);
    986 				goto sendorfree;
    987 			}
    988 			m_reset_rcvif(m);
    989 			m->m_flags = m0->m_flags & M_COPYFLAGS;
    990 			*mnext = m;
    991 			mnext = &m->m_nextpkt;
    992 			m->m_data += max_linkhdr;
    993 			mhip6 = mtod(m, struct ip6_hdr *);
    994 			*mhip6 = *ip6;
    995 			m->m_len = sizeof(*mhip6);
    996 			/*
    997 			 * ip6f must be valid if error is 0.  But how
    998 			 * can a compiler be expected to infer this?
    999 			 */
   1000 			ip6f = NULL;
   1001 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
   1002 			if (error) {
   1003 				IP6_STATINC(IP6_STAT_ODROPPED);
   1004 				goto sendorfree;
   1005 			}
   1006 			ip6f->ip6f_offlg = htons((u_int16_t)((off - hlen) & ~7));
   1007 			if (off + len >= tlen)
   1008 				len = tlen - off;
   1009 			else
   1010 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
   1011 			mhip6->ip6_plen = htons((u_int16_t)(len + hlen +
   1012 			    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
   1013 			if ((m_frgpart = m_copy(m0, off, len)) == 0) {
   1014 				error = ENOBUFS;
   1015 				IP6_STATINC(IP6_STAT_ODROPPED);
   1016 				goto sendorfree;
   1017 			}
   1018 			for (mlast = m; mlast->m_next; mlast = mlast->m_next)
   1019 				;
   1020 			mlast->m_next = m_frgpart;
   1021 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
   1022 			m_reset_rcvif(m);
   1023 			ip6f->ip6f_reserved = 0;
   1024 			ip6f->ip6f_ident = id;
   1025 			ip6f->ip6f_nxt = nextproto;
   1026 			IP6_STATINC(IP6_STAT_OFRAGMENTS);
   1027 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
   1028 		}
   1029 
   1030 		in6_ifstat_inc(ifp, ifs6_out_fragok);
   1031 	}
   1032 
   1033 	/*
   1034 	 * Remove leading garbages.
   1035 	 */
   1036 sendorfree:
   1037 	m = m0->m_nextpkt;
   1038 	m0->m_nextpkt = 0;
   1039 	m_freem(m0);
   1040 	for (m0 = m; m; m = m0) {
   1041 		m0 = m->m_nextpkt;
   1042 		m->m_nextpkt = 0;
   1043 		if (error == 0) {
   1044 			struct in6_ifaddr *ia6;
   1045 			int s;
   1046 			ip6 = mtod(m, struct ip6_hdr *);
   1047 			s = pserialize_read_enter();
   1048 			ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
   1049 			if (ia6) {
   1050 				/*
   1051 				 * Record statistics for this interface
   1052 				 * address.
   1053 				 */
   1054 				ia6->ia_ifa.ifa_data.ifad_outbytes +=
   1055 				    m->m_pkthdr.len;
   1056 			}
   1057 			pserialize_read_exit(s);
   1058 			KASSERT(dst != NULL);
   1059 			error = ip6_if_output(ifp, origifp, m, dst, rt);
   1060 		} else
   1061 			m_freem(m);
   1062 	}
   1063 
   1064 	if (error == 0)
   1065 		IP6_STATINC(IP6_STAT_FRAGMENTED);
   1066 
   1067 done:
   1068 	rtcache_unref(rt, ro);
   1069 	if (ro == &ip6route)
   1070 		rtcache_free(&ip6route);
   1071 
   1072 #ifdef IPSEC
   1073 	if (sp != NULL)
   1074 		KEY_SP_UNREF(&sp);
   1075 #endif /* IPSEC */
   1076 
   1077 	if_put(ifp, &psref);
   1078 	if (release_psref_ia)
   1079 		if_put(origifp, &psref_ia);
   1080 	curlwp_bindx(bound);
   1081 
   1082 	return (error);
   1083 
   1084 freehdrs:
   1085 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
   1086 	m_freem(exthdrs.ip6e_dest1);
   1087 	m_freem(exthdrs.ip6e_rthdr);
   1088 	m_freem(exthdrs.ip6e_dest2);
   1089 	/* FALLTHROUGH */
   1090 bad:
   1091 	m_freem(m);
   1092 	goto done;
   1093 badscope:
   1094 	IP6_STATINC(IP6_STAT_BADSCOPE);
   1095 	in6_ifstat_inc(origifp, ifs6_out_discard);
   1096 	if (error == 0)
   1097 		error = EHOSTUNREACH; /* XXX */
   1098 	goto bad;
   1099 }
   1100 
   1101 static int
   1102 ip6_copyexthdr(struct mbuf **mp, void *hdr, int hlen)
   1103 {
   1104 	struct mbuf *m;
   1105 
   1106 	if (hlen > MCLBYTES)
   1107 		return (ENOBUFS); /* XXX */
   1108 
   1109 	MGET(m, M_DONTWAIT, MT_DATA);
   1110 	if (!m)
   1111 		return (ENOBUFS);
   1112 
   1113 	if (hlen > MLEN) {
   1114 		MCLGET(m, M_DONTWAIT);
   1115 		if ((m->m_flags & M_EXT) == 0) {
   1116 			m_free(m);
   1117 			return (ENOBUFS);
   1118 		}
   1119 	}
   1120 	m->m_len = hlen;
   1121 	if (hdr)
   1122 		bcopy(hdr, mtod(m, void *), hlen);
   1123 
   1124 	*mp = m;
   1125 	return (0);
   1126 }
   1127 
   1128 /*
   1129  * Process a delayed payload checksum calculation.
   1130  */
   1131 void
   1132 in6_delayed_cksum(struct mbuf *m)
   1133 {
   1134 	uint16_t csum, offset;
   1135 
   1136 	KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1137 	KASSERT((~m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1138 	KASSERT((m->m_pkthdr.csum_flags
   1139 	    & (M_CSUM_UDPv4|M_CSUM_TCPv4|M_CSUM_TSOv4)) == 0);
   1140 
   1141 	offset = M_CSUM_DATA_IPv6_HL(m->m_pkthdr.csum_data);
   1142 	csum = in6_cksum(m, 0, offset, m->m_pkthdr.len - offset);
   1143 	if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv6) != 0) {
   1144 		csum = 0xffff;
   1145 	}
   1146 
   1147 	offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data);
   1148 	if ((offset + sizeof(csum)) > m->m_len) {
   1149 		m_copyback(m, offset, sizeof(csum), &csum);
   1150 	} else {
   1151 		*(uint16_t *)(mtod(m, char *) + offset) = csum;
   1152 	}
   1153 }
   1154 
   1155 /*
   1156  * Insert jumbo payload option.
   1157  */
   1158 static int
   1159 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
   1160 {
   1161 	struct mbuf *mopt;
   1162 	u_int8_t *optbuf;
   1163 	u_int32_t v;
   1164 
   1165 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
   1166 
   1167 	/*
   1168 	 * If there is no hop-by-hop options header, allocate new one.
   1169 	 * If there is one but it doesn't have enough space to store the
   1170 	 * jumbo payload option, allocate a cluster to store the whole options.
   1171 	 * Otherwise, use it to store the options.
   1172 	 */
   1173 	if (exthdrs->ip6e_hbh == 0) {
   1174 		MGET(mopt, M_DONTWAIT, MT_DATA);
   1175 		if (mopt == 0)
   1176 			return (ENOBUFS);
   1177 		mopt->m_len = JUMBOOPTLEN;
   1178 		optbuf = mtod(mopt, u_int8_t *);
   1179 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
   1180 		exthdrs->ip6e_hbh = mopt;
   1181 	} else {
   1182 		struct ip6_hbh *hbh;
   1183 
   1184 		mopt = exthdrs->ip6e_hbh;
   1185 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
   1186 			/*
   1187 			 * XXX assumption:
   1188 			 * - exthdrs->ip6e_hbh is not referenced from places
   1189 			 *   other than exthdrs.
   1190 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
   1191 			 */
   1192 			int oldoptlen = mopt->m_len;
   1193 			struct mbuf *n;
   1194 
   1195 			/*
   1196 			 * XXX: give up if the whole (new) hbh header does
   1197 			 * not fit even in an mbuf cluster.
   1198 			 */
   1199 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
   1200 				return (ENOBUFS);
   1201 
   1202 			/*
   1203 			 * As a consequence, we must always prepare a cluster
   1204 			 * at this point.
   1205 			 */
   1206 			MGET(n, M_DONTWAIT, MT_DATA);
   1207 			if (n) {
   1208 				MCLGET(n, M_DONTWAIT);
   1209 				if ((n->m_flags & M_EXT) == 0) {
   1210 					m_freem(n);
   1211 					n = NULL;
   1212 				}
   1213 			}
   1214 			if (!n)
   1215 				return (ENOBUFS);
   1216 			n->m_len = oldoptlen + JUMBOOPTLEN;
   1217 			bcopy(mtod(mopt, void *), mtod(n, void *),
   1218 			    oldoptlen);
   1219 			optbuf = mtod(n, u_int8_t *) + oldoptlen;
   1220 			m_freem(mopt);
   1221 			mopt = exthdrs->ip6e_hbh = n;
   1222 		} else {
   1223 			optbuf = mtod(mopt, u_int8_t *) + mopt->m_len;
   1224 			mopt->m_len += JUMBOOPTLEN;
   1225 		}
   1226 		optbuf[0] = IP6OPT_PADN;
   1227 		optbuf[1] = 0;
   1228 
   1229 		/*
   1230 		 * Adjust the header length according to the pad and
   1231 		 * the jumbo payload option.
   1232 		 */
   1233 		hbh = mtod(mopt, struct ip6_hbh *);
   1234 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
   1235 	}
   1236 
   1237 	/* fill in the option. */
   1238 	optbuf[2] = IP6OPT_JUMBO;
   1239 	optbuf[3] = 4;
   1240 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
   1241 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
   1242 
   1243 	/* finally, adjust the packet header length */
   1244 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
   1245 
   1246 	return (0);
   1247 #undef JUMBOOPTLEN
   1248 }
   1249 
   1250 /*
   1251  * Insert fragment header and copy unfragmentable header portions.
   1252  *
   1253  * *frghdrp will not be read, and it is guaranteed that either an
   1254  * error is returned or that *frghdrp will point to space allocated
   1255  * for the fragment header.
   1256  */
   1257 static int
   1258 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
   1259 	struct ip6_frag **frghdrp)
   1260 {
   1261 	struct mbuf *n, *mlast;
   1262 
   1263 	if (hlen > sizeof(struct ip6_hdr)) {
   1264 		n = m_copym(m0, sizeof(struct ip6_hdr),
   1265 		    hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
   1266 		if (n == 0)
   1267 			return (ENOBUFS);
   1268 		m->m_next = n;
   1269 	} else
   1270 		n = m;
   1271 
   1272 	/* Search for the last mbuf of unfragmentable part. */
   1273 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
   1274 		;
   1275 
   1276 	if ((mlast->m_flags & M_EXT) == 0 &&
   1277 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
   1278 		/* use the trailing space of the last mbuf for the fragment hdr */
   1279 		*frghdrp = (struct ip6_frag *)(mtod(mlast, char *) +
   1280 		    mlast->m_len);
   1281 		mlast->m_len += sizeof(struct ip6_frag);
   1282 		m->m_pkthdr.len += sizeof(struct ip6_frag);
   1283 	} else {
   1284 		/* allocate a new mbuf for the fragment header */
   1285 		struct mbuf *mfrg;
   1286 
   1287 		MGET(mfrg, M_DONTWAIT, MT_DATA);
   1288 		if (mfrg == 0)
   1289 			return (ENOBUFS);
   1290 		mfrg->m_len = sizeof(struct ip6_frag);
   1291 		*frghdrp = mtod(mfrg, struct ip6_frag *);
   1292 		mlast->m_next = mfrg;
   1293 	}
   1294 
   1295 	return (0);
   1296 }
   1297 
   1298 static int
   1299 ip6_getpmtu(struct rtentry *rt, struct ifnet *ifp, u_long *mtup,
   1300     int *alwaysfragp)
   1301 {
   1302 	u_int32_t mtu = 0;
   1303 	int alwaysfrag = 0;
   1304 	int error = 0;
   1305 
   1306 	if (rt != NULL) {
   1307 		u_int32_t ifmtu;
   1308 
   1309 		if (ifp == NULL)
   1310 			ifp = rt->rt_ifp;
   1311 		ifmtu = IN6_LINKMTU(ifp);
   1312 		mtu = rt->rt_rmx.rmx_mtu;
   1313 		if (mtu == 0)
   1314 			mtu = ifmtu;
   1315 		else if (mtu < IPV6_MMTU) {
   1316 			/*
   1317 			 * RFC2460 section 5, last paragraph:
   1318 			 * if we record ICMPv6 too big message with
   1319 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
   1320 			 * or smaller, with fragment header attached.
   1321 			 * (fragment header is needed regardless from the
   1322 			 * packet size, for translators to identify packets)
   1323 			 */
   1324 			alwaysfrag = 1;
   1325 			mtu = IPV6_MMTU;
   1326 		} else if (mtu > ifmtu) {
   1327 			/*
   1328 			 * The MTU on the route is larger than the MTU on
   1329 			 * the interface!  This shouldn't happen, unless the
   1330 			 * MTU of the interface has been changed after the
   1331 			 * interface was brought up.  Change the MTU in the
   1332 			 * route to match the interface MTU (as long as the
   1333 			 * field isn't locked).
   1334 			 */
   1335 			mtu = ifmtu;
   1336 			if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
   1337 				rt->rt_rmx.rmx_mtu = mtu;
   1338 		}
   1339 	} else if (ifp) {
   1340 		mtu = IN6_LINKMTU(ifp);
   1341 	} else
   1342 		error = EHOSTUNREACH; /* XXX */
   1343 
   1344 	*mtup = mtu;
   1345 	if (alwaysfragp)
   1346 		*alwaysfragp = alwaysfrag;
   1347 	return (error);
   1348 }
   1349 
   1350 /*
   1351  * IP6 socket option processing.
   1352  */
   1353 int
   1354 ip6_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   1355 {
   1356 	int optdatalen, uproto;
   1357 	void *optdata;
   1358 	struct in6pcb *in6p = sotoin6pcb(so);
   1359 	struct ip_moptions **mopts;
   1360 	int error, optval;
   1361 	int level, optname;
   1362 
   1363 	KASSERT(solocked(so));
   1364 	KASSERT(sopt != NULL);
   1365 
   1366 	level = sopt->sopt_level;
   1367 	optname = sopt->sopt_name;
   1368 
   1369 	error = optval = 0;
   1370 	uproto = (int)so->so_proto->pr_protocol;
   1371 
   1372 	switch (level) {
   1373 	case IPPROTO_IP:
   1374 		switch (optname) {
   1375 		case IP_ADD_MEMBERSHIP:
   1376 		case IP_DROP_MEMBERSHIP:
   1377 		case IP_MULTICAST_IF:
   1378 		case IP_MULTICAST_LOOP:
   1379 		case IP_MULTICAST_TTL:
   1380 			mopts = &in6p->in6p_v4moptions;
   1381 			switch (op) {
   1382 			case PRCO_GETOPT:
   1383 				return ip_getmoptions(*mopts, sopt);
   1384 			case PRCO_SETOPT:
   1385 				return ip_setmoptions(mopts, sopt);
   1386 			default:
   1387 				return EINVAL;
   1388 			}
   1389 		default:
   1390 			return ENOPROTOOPT;
   1391 		}
   1392 	case IPPROTO_IPV6:
   1393 		break;
   1394 	default:
   1395 		return ENOPROTOOPT;
   1396 	}
   1397 	switch (op) {
   1398 	case PRCO_SETOPT:
   1399 		switch (optname) {
   1400 #ifdef RFC2292
   1401 		case IPV6_2292PKTOPTIONS:
   1402 			error = ip6_pcbopts(&in6p->in6p_outputopts, so, sopt);
   1403 			break;
   1404 #endif
   1405 
   1406 		/*
   1407 		 * Use of some Hop-by-Hop options or some
   1408 		 * Destination options, might require special
   1409 		 * privilege.  That is, normal applications
   1410 		 * (without special privilege) might be forbidden
   1411 		 * from setting certain options in outgoing packets,
   1412 		 * and might never see certain options in received
   1413 		 * packets. [RFC 2292 Section 6]
   1414 		 * KAME specific note:
   1415 		 *  KAME prevents non-privileged users from sending or
   1416 		 *  receiving ANY hbh/dst options in order to avoid
   1417 		 *  overhead of parsing options in the kernel.
   1418 		 */
   1419 		case IPV6_RECVHOPOPTS:
   1420 		case IPV6_RECVDSTOPTS:
   1421 		case IPV6_RECVRTHDRDSTOPTS:
   1422 			error = kauth_authorize_network(kauth_cred_get(),
   1423 			    KAUTH_NETWORK_IPV6, KAUTH_REQ_NETWORK_IPV6_HOPBYHOP,
   1424 			    NULL, NULL, NULL);
   1425 			if (error)
   1426 				break;
   1427 			/* FALLTHROUGH */
   1428 		case IPV6_UNICAST_HOPS:
   1429 		case IPV6_HOPLIMIT:
   1430 		case IPV6_FAITH:
   1431 
   1432 		case IPV6_RECVPKTINFO:
   1433 		case IPV6_RECVHOPLIMIT:
   1434 		case IPV6_RECVRTHDR:
   1435 		case IPV6_RECVPATHMTU:
   1436 		case IPV6_RECVTCLASS:
   1437 		case IPV6_V6ONLY:
   1438 			error = sockopt_getint(sopt, &optval);
   1439 			if (error)
   1440 				break;
   1441 			switch (optname) {
   1442 			case IPV6_UNICAST_HOPS:
   1443 				if (optval < -1 || optval >= 256)
   1444 					error = EINVAL;
   1445 				else {
   1446 					/* -1 = kernel default */
   1447 					in6p->in6p_hops = optval;
   1448 				}
   1449 				break;
   1450 #define OPTSET(bit) \
   1451 do { \
   1452 if (optval) \
   1453 	in6p->in6p_flags |= (bit); \
   1454 else \
   1455 	in6p->in6p_flags &= ~(bit); \
   1456 } while (/*CONSTCOND*/ 0)
   1457 
   1458 #ifdef RFC2292
   1459 #define OPTSET2292(bit) 			\
   1460 do { 						\
   1461 in6p->in6p_flags |= IN6P_RFC2292; 	\
   1462 if (optval) 				\
   1463 	in6p->in6p_flags |= (bit); 	\
   1464 else 					\
   1465 	in6p->in6p_flags &= ~(bit); 	\
   1466 } while (/*CONSTCOND*/ 0)
   1467 #endif
   1468 
   1469 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
   1470 
   1471 			case IPV6_RECVPKTINFO:
   1472 #ifdef RFC2292
   1473 				/* cannot mix with RFC2292 */
   1474 				if (OPTBIT(IN6P_RFC2292)) {
   1475 					error = EINVAL;
   1476 					break;
   1477 				}
   1478 #endif
   1479 				OPTSET(IN6P_PKTINFO);
   1480 				break;
   1481 
   1482 			case IPV6_HOPLIMIT:
   1483 			{
   1484 				struct ip6_pktopts **optp;
   1485 
   1486 #ifdef RFC2292
   1487 				/* cannot mix with RFC2292 */
   1488 				if (OPTBIT(IN6P_RFC2292)) {
   1489 					error = EINVAL;
   1490 					break;
   1491 				}
   1492 #endif
   1493 				optp = &in6p->in6p_outputopts;
   1494 				error = ip6_pcbopt(IPV6_HOPLIMIT,
   1495 						   (u_char *)&optval,
   1496 						   sizeof(optval),
   1497 						   optp,
   1498 						   kauth_cred_get(), uproto);
   1499 				break;
   1500 			}
   1501 
   1502 			case IPV6_RECVHOPLIMIT:
   1503 #ifdef RFC2292
   1504 				/* cannot mix with RFC2292 */
   1505 				if (OPTBIT(IN6P_RFC2292)) {
   1506 					error = EINVAL;
   1507 					break;
   1508 				}
   1509 #endif
   1510 				OPTSET(IN6P_HOPLIMIT);
   1511 				break;
   1512 
   1513 			case IPV6_RECVHOPOPTS:
   1514 #ifdef RFC2292
   1515 				/* cannot mix with RFC2292 */
   1516 				if (OPTBIT(IN6P_RFC2292)) {
   1517 					error = EINVAL;
   1518 					break;
   1519 				}
   1520 #endif
   1521 				OPTSET(IN6P_HOPOPTS);
   1522 				break;
   1523 
   1524 			case IPV6_RECVDSTOPTS:
   1525 #ifdef RFC2292
   1526 				/* cannot mix with RFC2292 */
   1527 				if (OPTBIT(IN6P_RFC2292)) {
   1528 					error = EINVAL;
   1529 					break;
   1530 				}
   1531 #endif
   1532 				OPTSET(IN6P_DSTOPTS);
   1533 				break;
   1534 
   1535 			case IPV6_RECVRTHDRDSTOPTS:
   1536 #ifdef RFC2292
   1537 				/* cannot mix with RFC2292 */
   1538 				if (OPTBIT(IN6P_RFC2292)) {
   1539 					error = EINVAL;
   1540 					break;
   1541 				}
   1542 #endif
   1543 				OPTSET(IN6P_RTHDRDSTOPTS);
   1544 				break;
   1545 
   1546 			case IPV6_RECVRTHDR:
   1547 #ifdef RFC2292
   1548 				/* cannot mix with RFC2292 */
   1549 				if (OPTBIT(IN6P_RFC2292)) {
   1550 					error = EINVAL;
   1551 					break;
   1552 				}
   1553 #endif
   1554 				OPTSET(IN6P_RTHDR);
   1555 				break;
   1556 
   1557 			case IPV6_FAITH:
   1558 				OPTSET(IN6P_FAITH);
   1559 				break;
   1560 
   1561 			case IPV6_RECVPATHMTU:
   1562 				/*
   1563 				 * We ignore this option for TCP
   1564 				 * sockets.
   1565 				 * (RFC3542 leaves this case
   1566 				 * unspecified.)
   1567 				 */
   1568 				if (uproto != IPPROTO_TCP)
   1569 					OPTSET(IN6P_MTU);
   1570 				break;
   1571 
   1572 			case IPV6_V6ONLY:
   1573 				/*
   1574 				 * make setsockopt(IPV6_V6ONLY)
   1575 				 * available only prior to bind(2).
   1576 				 * see ipng mailing list, Jun 22 2001.
   1577 				 */
   1578 				if (in6p->in6p_lport ||
   1579 				    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
   1580 					error = EINVAL;
   1581 					break;
   1582 				}
   1583 #ifdef INET6_BINDV6ONLY
   1584 				if (!optval)
   1585 					error = EINVAL;
   1586 #else
   1587 				OPTSET(IN6P_IPV6_V6ONLY);
   1588 #endif
   1589 				break;
   1590 			case IPV6_RECVTCLASS:
   1591 #ifdef RFC2292
   1592 				/* cannot mix with RFC2292 XXX */
   1593 				if (OPTBIT(IN6P_RFC2292)) {
   1594 					error = EINVAL;
   1595 					break;
   1596 				}
   1597 #endif
   1598 				OPTSET(IN6P_TCLASS);
   1599 				break;
   1600 
   1601 			}
   1602 			break;
   1603 
   1604 		case IPV6_OTCLASS:
   1605 		{
   1606 			struct ip6_pktopts **optp;
   1607 			u_int8_t tclass;
   1608 
   1609 			error = sockopt_get(sopt, &tclass, sizeof(tclass));
   1610 			if (error)
   1611 				break;
   1612 			optp = &in6p->in6p_outputopts;
   1613 			error = ip6_pcbopt(optname,
   1614 					   (u_char *)&tclass,
   1615 					   sizeof(tclass),
   1616 					   optp,
   1617 					   kauth_cred_get(), uproto);
   1618 			break;
   1619 		}
   1620 
   1621 		case IPV6_TCLASS:
   1622 		case IPV6_DONTFRAG:
   1623 		case IPV6_USE_MIN_MTU:
   1624 		case IPV6_PREFER_TEMPADDR:
   1625 			error = sockopt_getint(sopt, &optval);
   1626 			if (error)
   1627 				break;
   1628 			{
   1629 				struct ip6_pktopts **optp;
   1630 				optp = &in6p->in6p_outputopts;
   1631 				error = ip6_pcbopt(optname,
   1632 						   (u_char *)&optval,
   1633 						   sizeof(optval),
   1634 						   optp,
   1635 						   kauth_cred_get(), uproto);
   1636 				break;
   1637 			}
   1638 
   1639 #ifdef RFC2292
   1640 		case IPV6_2292PKTINFO:
   1641 		case IPV6_2292HOPLIMIT:
   1642 		case IPV6_2292HOPOPTS:
   1643 		case IPV6_2292DSTOPTS:
   1644 		case IPV6_2292RTHDR:
   1645 			/* RFC 2292 */
   1646 			error = sockopt_getint(sopt, &optval);
   1647 			if (error)
   1648 				break;
   1649 
   1650 			switch (optname) {
   1651 			case IPV6_2292PKTINFO:
   1652 				OPTSET2292(IN6P_PKTINFO);
   1653 				break;
   1654 			case IPV6_2292HOPLIMIT:
   1655 				OPTSET2292(IN6P_HOPLIMIT);
   1656 				break;
   1657 			case IPV6_2292HOPOPTS:
   1658 				/*
   1659 				 * Check super-user privilege.
   1660 				 * See comments for IPV6_RECVHOPOPTS.
   1661 				 */
   1662 				error =
   1663 				    kauth_authorize_network(kauth_cred_get(),
   1664 				    KAUTH_NETWORK_IPV6,
   1665 				    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL,
   1666 				    NULL, NULL);
   1667 				if (error)
   1668 					return (error);
   1669 				OPTSET2292(IN6P_HOPOPTS);
   1670 				break;
   1671 			case IPV6_2292DSTOPTS:
   1672 				error =
   1673 				    kauth_authorize_network(kauth_cred_get(),
   1674 				    KAUTH_NETWORK_IPV6,
   1675 				    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL,
   1676 				    NULL, NULL);
   1677 				if (error)
   1678 					return (error);
   1679 				OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
   1680 				break;
   1681 			case IPV6_2292RTHDR:
   1682 				OPTSET2292(IN6P_RTHDR);
   1683 				break;
   1684 			}
   1685 			break;
   1686 #endif
   1687 		case IPV6_PKTINFO:
   1688 		case IPV6_HOPOPTS:
   1689 		case IPV6_RTHDR:
   1690 		case IPV6_DSTOPTS:
   1691 		case IPV6_RTHDRDSTOPTS:
   1692 		case IPV6_NEXTHOP: {
   1693 			/* new advanced API (RFC3542) */
   1694 			void *optbuf;
   1695 			int optbuflen;
   1696 			struct ip6_pktopts **optp;
   1697 
   1698 #ifdef RFC2292
   1699 			/* cannot mix with RFC2292 */
   1700 			if (OPTBIT(IN6P_RFC2292)) {
   1701 				error = EINVAL;
   1702 				break;
   1703 			}
   1704 #endif
   1705 
   1706 			optbuflen = sopt->sopt_size;
   1707 			optbuf = malloc(optbuflen, M_IP6OPT, M_NOWAIT);
   1708 			if (optbuf == NULL) {
   1709 				error = ENOBUFS;
   1710 				break;
   1711 			}
   1712 
   1713 			error = sockopt_get(sopt, optbuf, optbuflen);
   1714 			if (error) {
   1715 				free(optbuf, M_IP6OPT);
   1716 				break;
   1717 			}
   1718 			optp = &in6p->in6p_outputopts;
   1719 			error = ip6_pcbopt(optname, optbuf, optbuflen,
   1720 			    optp, kauth_cred_get(), uproto);
   1721 
   1722 			free(optbuf, M_IP6OPT);
   1723 			break;
   1724 			}
   1725 #undef OPTSET
   1726 
   1727 		case IPV6_MULTICAST_IF:
   1728 		case IPV6_MULTICAST_HOPS:
   1729 		case IPV6_MULTICAST_LOOP:
   1730 		case IPV6_JOIN_GROUP:
   1731 		case IPV6_LEAVE_GROUP:
   1732 			error = ip6_setmoptions(sopt, in6p);
   1733 			break;
   1734 
   1735 		case IPV6_PORTRANGE:
   1736 			error = sockopt_getint(sopt, &optval);
   1737 			if (error)
   1738 				break;
   1739 
   1740 			switch (optval) {
   1741 			case IPV6_PORTRANGE_DEFAULT:
   1742 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1743 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1744 				break;
   1745 
   1746 			case IPV6_PORTRANGE_HIGH:
   1747 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1748 				in6p->in6p_flags |= IN6P_HIGHPORT;
   1749 				break;
   1750 
   1751 			case IPV6_PORTRANGE_LOW:
   1752 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1753 				in6p->in6p_flags |= IN6P_LOWPORT;
   1754 				break;
   1755 
   1756 			default:
   1757 				error = EINVAL;
   1758 				break;
   1759 			}
   1760 			break;
   1761 
   1762 		case IPV6_PORTALGO:
   1763 			error = sockopt_getint(sopt, &optval);
   1764 			if (error)
   1765 				break;
   1766 
   1767 			error = portalgo_algo_index_select(
   1768 			    (struct inpcb_hdr *)in6p, optval);
   1769 			break;
   1770 
   1771 #if defined(IPSEC)
   1772 		case IPV6_IPSEC_POLICY:
   1773 			if (ipsec_enabled) {
   1774 				error = ipsec6_set_policy(in6p, optname,
   1775 				    sopt->sopt_data, sopt->sopt_size,
   1776 				    kauth_cred_get());
   1777 				break;
   1778 			}
   1779 			/*FALLTHROUGH*/
   1780 #endif /* IPSEC */
   1781 
   1782 		default:
   1783 			error = ENOPROTOOPT;
   1784 			break;
   1785 		}
   1786 		break;
   1787 
   1788 	case PRCO_GETOPT:
   1789 		switch (optname) {
   1790 #ifdef RFC2292
   1791 		case IPV6_2292PKTOPTIONS:
   1792 			/*
   1793 			 * RFC3542 (effectively) deprecated the
   1794 			 * semantics of the 2292-style pktoptions.
   1795 			 * Since it was not reliable in nature (i.e.,
   1796 			 * applications had to expect the lack of some
   1797 			 * information after all), it would make sense
   1798 			 * to simplify this part by always returning
   1799 			 * empty data.
   1800 			 */
   1801 			break;
   1802 #endif
   1803 
   1804 		case IPV6_RECVHOPOPTS:
   1805 		case IPV6_RECVDSTOPTS:
   1806 		case IPV6_RECVRTHDRDSTOPTS:
   1807 		case IPV6_UNICAST_HOPS:
   1808 		case IPV6_RECVPKTINFO:
   1809 		case IPV6_RECVHOPLIMIT:
   1810 		case IPV6_RECVRTHDR:
   1811 		case IPV6_RECVPATHMTU:
   1812 
   1813 		case IPV6_FAITH:
   1814 		case IPV6_V6ONLY:
   1815 		case IPV6_PORTRANGE:
   1816 		case IPV6_RECVTCLASS:
   1817 			switch (optname) {
   1818 
   1819 			case IPV6_RECVHOPOPTS:
   1820 				optval = OPTBIT(IN6P_HOPOPTS);
   1821 				break;
   1822 
   1823 			case IPV6_RECVDSTOPTS:
   1824 				optval = OPTBIT(IN6P_DSTOPTS);
   1825 				break;
   1826 
   1827 			case IPV6_RECVRTHDRDSTOPTS:
   1828 				optval = OPTBIT(IN6P_RTHDRDSTOPTS);
   1829 				break;
   1830 
   1831 			case IPV6_UNICAST_HOPS:
   1832 				optval = in6p->in6p_hops;
   1833 				break;
   1834 
   1835 			case IPV6_RECVPKTINFO:
   1836 				optval = OPTBIT(IN6P_PKTINFO);
   1837 				break;
   1838 
   1839 			case IPV6_RECVHOPLIMIT:
   1840 				optval = OPTBIT(IN6P_HOPLIMIT);
   1841 				break;
   1842 
   1843 			case IPV6_RECVRTHDR:
   1844 				optval = OPTBIT(IN6P_RTHDR);
   1845 				break;
   1846 
   1847 			case IPV6_RECVPATHMTU:
   1848 				optval = OPTBIT(IN6P_MTU);
   1849 				break;
   1850 
   1851 			case IPV6_FAITH:
   1852 				optval = OPTBIT(IN6P_FAITH);
   1853 				break;
   1854 
   1855 			case IPV6_V6ONLY:
   1856 				optval = OPTBIT(IN6P_IPV6_V6ONLY);
   1857 				break;
   1858 
   1859 			case IPV6_PORTRANGE:
   1860 			    {
   1861 				int flags;
   1862 				flags = in6p->in6p_flags;
   1863 				if (flags & IN6P_HIGHPORT)
   1864 					optval = IPV6_PORTRANGE_HIGH;
   1865 				else if (flags & IN6P_LOWPORT)
   1866 					optval = IPV6_PORTRANGE_LOW;
   1867 				else
   1868 					optval = 0;
   1869 				break;
   1870 			    }
   1871 			case IPV6_RECVTCLASS:
   1872 				optval = OPTBIT(IN6P_TCLASS);
   1873 				break;
   1874 
   1875 			}
   1876 			if (error)
   1877 				break;
   1878 			error = sockopt_setint(sopt, optval);
   1879 			break;
   1880 
   1881 		case IPV6_PATHMTU:
   1882 		    {
   1883 			u_long pmtu = 0;
   1884 			struct ip6_mtuinfo mtuinfo;
   1885 			struct route *ro = &in6p->in6p_route;
   1886 			struct rtentry *rt;
   1887 			union {
   1888 				struct sockaddr		dst;
   1889 				struct sockaddr_in6	dst6;
   1890 			} u;
   1891 
   1892 			if (!(so->so_state & SS_ISCONNECTED))
   1893 				return (ENOTCONN);
   1894 			/*
   1895 			 * XXX: we dot not consider the case of source
   1896 			 * routing, or optional information to specify
   1897 			 * the outgoing interface.
   1898 			 */
   1899 			sockaddr_in6_init(&u.dst6, &in6p->in6p_faddr, 0, 0, 0);
   1900 			rt = rtcache_lookup(ro, &u.dst);
   1901 			error = ip6_getpmtu(rt, NULL, &pmtu, NULL);
   1902 			rtcache_unref(rt, ro);
   1903 			if (error)
   1904 				break;
   1905 			if (pmtu > IPV6_MAXPACKET)
   1906 				pmtu = IPV6_MAXPACKET;
   1907 
   1908 			memset(&mtuinfo, 0, sizeof(mtuinfo));
   1909 			mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
   1910 			optdata = (void *)&mtuinfo;
   1911 			optdatalen = sizeof(mtuinfo);
   1912 			if (optdatalen > MCLBYTES)
   1913 				return (EMSGSIZE); /* XXX */
   1914 			error = sockopt_set(sopt, optdata, optdatalen);
   1915 			break;
   1916 		    }
   1917 
   1918 #ifdef RFC2292
   1919 		case IPV6_2292PKTINFO:
   1920 		case IPV6_2292HOPLIMIT:
   1921 		case IPV6_2292HOPOPTS:
   1922 		case IPV6_2292RTHDR:
   1923 		case IPV6_2292DSTOPTS:
   1924 			switch (optname) {
   1925 			case IPV6_2292PKTINFO:
   1926 				optval = OPTBIT(IN6P_PKTINFO);
   1927 				break;
   1928 			case IPV6_2292HOPLIMIT:
   1929 				optval = OPTBIT(IN6P_HOPLIMIT);
   1930 				break;
   1931 			case IPV6_2292HOPOPTS:
   1932 				optval = OPTBIT(IN6P_HOPOPTS);
   1933 				break;
   1934 			case IPV6_2292RTHDR:
   1935 				optval = OPTBIT(IN6P_RTHDR);
   1936 				break;
   1937 			case IPV6_2292DSTOPTS:
   1938 				optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
   1939 				break;
   1940 			}
   1941 			error = sockopt_setint(sopt, optval);
   1942 			break;
   1943 #endif
   1944 		case IPV6_PKTINFO:
   1945 		case IPV6_HOPOPTS:
   1946 		case IPV6_RTHDR:
   1947 		case IPV6_DSTOPTS:
   1948 		case IPV6_RTHDRDSTOPTS:
   1949 		case IPV6_NEXTHOP:
   1950 		case IPV6_OTCLASS:
   1951 		case IPV6_TCLASS:
   1952 		case IPV6_DONTFRAG:
   1953 		case IPV6_USE_MIN_MTU:
   1954 		case IPV6_PREFER_TEMPADDR:
   1955 			error = ip6_getpcbopt(in6p->in6p_outputopts,
   1956 			    optname, sopt);
   1957 			break;
   1958 
   1959 		case IPV6_MULTICAST_IF:
   1960 		case IPV6_MULTICAST_HOPS:
   1961 		case IPV6_MULTICAST_LOOP:
   1962 		case IPV6_JOIN_GROUP:
   1963 		case IPV6_LEAVE_GROUP:
   1964 			error = ip6_getmoptions(sopt, in6p);
   1965 			break;
   1966 
   1967 		case IPV6_PORTALGO:
   1968 			optval = ((struct inpcb_hdr *)in6p)->inph_portalgo;
   1969 			error = sockopt_setint(sopt, optval);
   1970 			break;
   1971 
   1972 #if defined(IPSEC)
   1973 		case IPV6_IPSEC_POLICY:
   1974 			if (ipsec_used) {
   1975 				struct mbuf *m = NULL;
   1976 
   1977 				/*
   1978 				 * XXX: this will return EINVAL as sopt is
   1979 				 * empty
   1980 				 */
   1981 				error = ipsec6_get_policy(in6p, sopt->sopt_data,
   1982 				    sopt->sopt_size, &m);
   1983 				if (!error)
   1984 					error = sockopt_setmbuf(sopt, m);
   1985 				break;
   1986 			}
   1987 			/*FALLTHROUGH*/
   1988 #endif /* IPSEC */
   1989 
   1990 		default:
   1991 			error = ENOPROTOOPT;
   1992 			break;
   1993 		}
   1994 		break;
   1995 	}
   1996 	return (error);
   1997 }
   1998 
   1999 int
   2000 ip6_raw_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   2001 {
   2002 	int error = 0, optval;
   2003 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
   2004 	struct in6pcb *in6p = sotoin6pcb(so);
   2005 	int level, optname;
   2006 
   2007 	KASSERT(sopt != NULL);
   2008 
   2009 	level = sopt->sopt_level;
   2010 	optname = sopt->sopt_name;
   2011 
   2012 	if (level != IPPROTO_IPV6) {
   2013 		return ENOPROTOOPT;
   2014 	}
   2015 
   2016 	switch (optname) {
   2017 	case IPV6_CHECKSUM:
   2018 		/*
   2019 		 * For ICMPv6 sockets, no modification allowed for checksum
   2020 		 * offset, permit "no change" values to help existing apps.
   2021 		 *
   2022 		 * XXX RFC3542 says: "An attempt to set IPV6_CHECKSUM
   2023 		 * for an ICMPv6 socket will fail."  The current
   2024 		 * behavior does not meet RFC3542.
   2025 		 */
   2026 		switch (op) {
   2027 		case PRCO_SETOPT:
   2028 			error = sockopt_getint(sopt, &optval);
   2029 			if (error)
   2030 				break;
   2031 			if ((optval % 2) != 0) {
   2032 				/* the API assumes even offset values */
   2033 				error = EINVAL;
   2034 			} else if (so->so_proto->pr_protocol ==
   2035 			    IPPROTO_ICMPV6) {
   2036 				if (optval != icmp6off)
   2037 					error = EINVAL;
   2038 			} else
   2039 				in6p->in6p_cksum = optval;
   2040 			break;
   2041 
   2042 		case PRCO_GETOPT:
   2043 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
   2044 				optval = icmp6off;
   2045 			else
   2046 				optval = in6p->in6p_cksum;
   2047 
   2048 			error = sockopt_setint(sopt, optval);
   2049 			break;
   2050 
   2051 		default:
   2052 			error = EINVAL;
   2053 			break;
   2054 		}
   2055 		break;
   2056 
   2057 	default:
   2058 		error = ENOPROTOOPT;
   2059 		break;
   2060 	}
   2061 
   2062 	return (error);
   2063 }
   2064 
   2065 #ifdef RFC2292
   2066 /*
   2067  * Set up IP6 options in pcb for insertion in output packets or
   2068  * specifying behavior of outgoing packets.
   2069  */
   2070 static int
   2071 ip6_pcbopts(struct ip6_pktopts **pktopt, struct socket *so,
   2072     struct sockopt *sopt)
   2073 {
   2074 	struct ip6_pktopts *opt = *pktopt;
   2075 	struct mbuf *m;
   2076 	int error = 0;
   2077 
   2078 	KASSERT(solocked(so));
   2079 
   2080 	/* turn off any old options. */
   2081 	if (opt) {
   2082 #ifdef DIAGNOSTIC
   2083 	    if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
   2084 		opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
   2085 		opt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2086 		    printf("ip6_pcbopts: all specified options are cleared.\n");
   2087 #endif
   2088 		ip6_clearpktopts(opt, -1);
   2089 	} else {
   2090 		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
   2091 		if (opt == NULL)
   2092 			return (ENOBUFS);
   2093 	}
   2094 	*pktopt = NULL;
   2095 
   2096 	if (sopt == NULL || sopt->sopt_size == 0) {
   2097 		/*
   2098 		 * Only turning off any previous options, regardless of
   2099 		 * whether the opt is just created or given.
   2100 		 */
   2101 		free(opt, M_IP6OPT);
   2102 		return (0);
   2103 	}
   2104 
   2105 	/*  set options specified by user. */
   2106 	m = sockopt_getmbuf(sopt);
   2107 	if (m == NULL) {
   2108 		free(opt, M_IP6OPT);
   2109 		return (ENOBUFS);
   2110 	}
   2111 
   2112 	error = ip6_setpktopts(m, opt, NULL, kauth_cred_get(),
   2113 	    so->so_proto->pr_protocol);
   2114 	m_freem(m);
   2115 	if (error != 0) {
   2116 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
   2117 		free(opt, M_IP6OPT);
   2118 		return (error);
   2119 	}
   2120 	*pktopt = opt;
   2121 	return (0);
   2122 }
   2123 #endif
   2124 
   2125 /*
   2126  * initialize ip6_pktopts.  beware that there are non-zero default values in
   2127  * the struct.
   2128  */
   2129 void
   2130 ip6_initpktopts(struct ip6_pktopts *opt)
   2131 {
   2132 
   2133 	memset(opt, 0, sizeof(*opt));
   2134 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
   2135 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
   2136 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
   2137 	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
   2138 }
   2139 
   2140 #define sin6tosa(sin6)	((struct sockaddr *)(sin6)) /* XXX */
   2141 static int
   2142 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
   2143     kauth_cred_t cred, int uproto)
   2144 {
   2145 	struct ip6_pktopts *opt;
   2146 
   2147 	if (*pktopt == NULL) {
   2148 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
   2149 		    M_NOWAIT);
   2150 		if (*pktopt == NULL)
   2151 			return (ENOBUFS);
   2152 
   2153 		ip6_initpktopts(*pktopt);
   2154 	}
   2155 	opt = *pktopt;
   2156 
   2157 	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
   2158 }
   2159 
   2160 static int
   2161 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
   2162 {
   2163 	void *optdata = NULL;
   2164 	int optdatalen = 0;
   2165 	struct ip6_ext *ip6e;
   2166 	int error = 0;
   2167 	struct in6_pktinfo null_pktinfo;
   2168 	int deftclass = 0, on;
   2169 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
   2170 	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
   2171 
   2172 	switch (optname) {
   2173 	case IPV6_PKTINFO:
   2174 		if (pktopt && pktopt->ip6po_pktinfo)
   2175 			optdata = (void *)pktopt->ip6po_pktinfo;
   2176 		else {
   2177 			/* XXX: we don't have to do this every time... */
   2178 			memset(&null_pktinfo, 0, sizeof(null_pktinfo));
   2179 			optdata = (void *)&null_pktinfo;
   2180 		}
   2181 		optdatalen = sizeof(struct in6_pktinfo);
   2182 		break;
   2183 	case IPV6_OTCLASS:
   2184 		/* XXX */
   2185 		return (EINVAL);
   2186 	case IPV6_TCLASS:
   2187 		if (pktopt && pktopt->ip6po_tclass >= 0)
   2188 			optdata = (void *)&pktopt->ip6po_tclass;
   2189 		else
   2190 			optdata = (void *)&deftclass;
   2191 		optdatalen = sizeof(int);
   2192 		break;
   2193 	case IPV6_HOPOPTS:
   2194 		if (pktopt && pktopt->ip6po_hbh) {
   2195 			optdata = (void *)pktopt->ip6po_hbh;
   2196 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
   2197 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2198 		}
   2199 		break;
   2200 	case IPV6_RTHDR:
   2201 		if (pktopt && pktopt->ip6po_rthdr) {
   2202 			optdata = (void *)pktopt->ip6po_rthdr;
   2203 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
   2204 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2205 		}
   2206 		break;
   2207 	case IPV6_RTHDRDSTOPTS:
   2208 		if (pktopt && pktopt->ip6po_dest1) {
   2209 			optdata = (void *)pktopt->ip6po_dest1;
   2210 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
   2211 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2212 		}
   2213 		break;
   2214 	case IPV6_DSTOPTS:
   2215 		if (pktopt && pktopt->ip6po_dest2) {
   2216 			optdata = (void *)pktopt->ip6po_dest2;
   2217 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
   2218 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2219 		}
   2220 		break;
   2221 	case IPV6_NEXTHOP:
   2222 		if (pktopt && pktopt->ip6po_nexthop) {
   2223 			optdata = (void *)pktopt->ip6po_nexthop;
   2224 			optdatalen = pktopt->ip6po_nexthop->sa_len;
   2225 		}
   2226 		break;
   2227 	case IPV6_USE_MIN_MTU:
   2228 		if (pktopt)
   2229 			optdata = (void *)&pktopt->ip6po_minmtu;
   2230 		else
   2231 			optdata = (void *)&defminmtu;
   2232 		optdatalen = sizeof(int);
   2233 		break;
   2234 	case IPV6_DONTFRAG:
   2235 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
   2236 			on = 1;
   2237 		else
   2238 			on = 0;
   2239 		optdata = (void *)&on;
   2240 		optdatalen = sizeof(on);
   2241 		break;
   2242 	case IPV6_PREFER_TEMPADDR:
   2243 		if (pktopt)
   2244 			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
   2245 		else
   2246 			optdata = (void *)&defpreftemp;
   2247 		optdatalen = sizeof(int);
   2248 		break;
   2249 	default:		/* should not happen */
   2250 #ifdef DIAGNOSTIC
   2251 		panic("ip6_getpcbopt: unexpected option\n");
   2252 #endif
   2253 		return (ENOPROTOOPT);
   2254 	}
   2255 
   2256 	error = sockopt_set(sopt, optdata, optdatalen);
   2257 
   2258 	return (error);
   2259 }
   2260 
   2261 void
   2262 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
   2263 {
   2264 	if (optname == -1 || optname == IPV6_PKTINFO) {
   2265 		if (pktopt->ip6po_pktinfo)
   2266 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
   2267 		pktopt->ip6po_pktinfo = NULL;
   2268 	}
   2269 	if (optname == -1 || optname == IPV6_HOPLIMIT)
   2270 		pktopt->ip6po_hlim = -1;
   2271 	if (optname == -1 || optname == IPV6_TCLASS)
   2272 		pktopt->ip6po_tclass = -1;
   2273 	if (optname == -1 || optname == IPV6_NEXTHOP) {
   2274 		rtcache_free(&pktopt->ip6po_nextroute);
   2275 		if (pktopt->ip6po_nexthop)
   2276 			free(pktopt->ip6po_nexthop, M_IP6OPT);
   2277 		pktopt->ip6po_nexthop = NULL;
   2278 	}
   2279 	if (optname == -1 || optname == IPV6_HOPOPTS) {
   2280 		if (pktopt->ip6po_hbh)
   2281 			free(pktopt->ip6po_hbh, M_IP6OPT);
   2282 		pktopt->ip6po_hbh = NULL;
   2283 	}
   2284 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
   2285 		if (pktopt->ip6po_dest1)
   2286 			free(pktopt->ip6po_dest1, M_IP6OPT);
   2287 		pktopt->ip6po_dest1 = NULL;
   2288 	}
   2289 	if (optname == -1 || optname == IPV6_RTHDR) {
   2290 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2291 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
   2292 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
   2293 		rtcache_free(&pktopt->ip6po_route);
   2294 	}
   2295 	if (optname == -1 || optname == IPV6_DSTOPTS) {
   2296 		if (pktopt->ip6po_dest2)
   2297 			free(pktopt->ip6po_dest2, M_IP6OPT);
   2298 		pktopt->ip6po_dest2 = NULL;
   2299 	}
   2300 }
   2301 
   2302 #define PKTOPT_EXTHDRCPY(type) 					\
   2303 do {								\
   2304 	if (src->type) {					\
   2305 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
   2306 		dst->type = malloc(hlen, M_IP6OPT, canwait);	\
   2307 		if (dst->type == NULL)				\
   2308 			goto bad;				\
   2309 		memcpy(dst->type, src->type, hlen);		\
   2310 	}							\
   2311 } while (/*CONSTCOND*/ 0)
   2312 
   2313 static int
   2314 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
   2315 {
   2316 	dst->ip6po_hlim = src->ip6po_hlim;
   2317 	dst->ip6po_tclass = src->ip6po_tclass;
   2318 	dst->ip6po_flags = src->ip6po_flags;
   2319 	dst->ip6po_minmtu = src->ip6po_minmtu;
   2320 	dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
   2321 	if (src->ip6po_pktinfo) {
   2322 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
   2323 		    M_IP6OPT, canwait);
   2324 		if (dst->ip6po_pktinfo == NULL)
   2325 			goto bad;
   2326 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
   2327 	}
   2328 	if (src->ip6po_nexthop) {
   2329 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
   2330 		    M_IP6OPT, canwait);
   2331 		if (dst->ip6po_nexthop == NULL)
   2332 			goto bad;
   2333 		memcpy(dst->ip6po_nexthop, src->ip6po_nexthop,
   2334 		    src->ip6po_nexthop->sa_len);
   2335 	}
   2336 	PKTOPT_EXTHDRCPY(ip6po_hbh);
   2337 	PKTOPT_EXTHDRCPY(ip6po_dest1);
   2338 	PKTOPT_EXTHDRCPY(ip6po_dest2);
   2339 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
   2340 	return (0);
   2341 
   2342   bad:
   2343 	if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
   2344 	if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
   2345 	if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
   2346 	if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
   2347 	if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
   2348 	if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
   2349 
   2350 	return (ENOBUFS);
   2351 }
   2352 #undef PKTOPT_EXTHDRCPY
   2353 
   2354 struct ip6_pktopts *
   2355 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
   2356 {
   2357 	int error;
   2358 	struct ip6_pktopts *dst;
   2359 
   2360 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
   2361 	if (dst == NULL)
   2362 		return (NULL);
   2363 	ip6_initpktopts(dst);
   2364 
   2365 	if ((error = copypktopts(dst, src, canwait)) != 0) {
   2366 		free(dst, M_IP6OPT);
   2367 		return (NULL);
   2368 	}
   2369 
   2370 	return (dst);
   2371 }
   2372 
   2373 void
   2374 ip6_freepcbopts(struct ip6_pktopts *pktopt)
   2375 {
   2376 	if (pktopt == NULL)
   2377 		return;
   2378 
   2379 	ip6_clearpktopts(pktopt, -1);
   2380 
   2381 	free(pktopt, M_IP6OPT);
   2382 }
   2383 
   2384 int
   2385 ip6_get_membership(const struct sockopt *sopt, struct ifnet **ifp,
   2386     struct psref *psref, void *v, size_t l)
   2387 {
   2388 	struct ipv6_mreq mreq;
   2389 	int error;
   2390 	struct in6_addr *ia = &mreq.ipv6mr_multiaddr;
   2391 	struct in_addr *ia4 = (void *)&ia->s6_addr32[3];
   2392 
   2393 	error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2394 	if (error != 0)
   2395 		return error;
   2396 
   2397 	if (IN6_IS_ADDR_UNSPECIFIED(ia)) {
   2398 		/*
   2399 		 * We use the unspecified address to specify to accept
   2400 		 * all multicast addresses. Only super user is allowed
   2401 		 * to do this.
   2402 		 */
   2403 		if (kauth_authorize_network(curlwp->l_cred, KAUTH_NETWORK_IPV6,
   2404 		    KAUTH_REQ_NETWORK_IPV6_JOIN_MULTICAST, NULL, NULL, NULL))
   2405 			return EACCES;
   2406 	} else if (IN6_IS_ADDR_V4MAPPED(ia)) {
   2407 		// Don't bother if we are not going to use ifp.
   2408 		if (l == sizeof(*ia)) {
   2409 			memcpy(v, ia, l);
   2410 			return 0;
   2411 		}
   2412 	} else if (!IN6_IS_ADDR_MULTICAST(ia)) {
   2413 		return EINVAL;
   2414 	}
   2415 
   2416 	/*
   2417 	 * If no interface was explicitly specified, choose an
   2418 	 * appropriate one according to the given multicast address.
   2419 	 */
   2420 	if (mreq.ipv6mr_interface == 0) {
   2421 		struct rtentry *rt;
   2422 		union {
   2423 			struct sockaddr		dst;
   2424 			struct sockaddr_in	dst4;
   2425 			struct sockaddr_in6	dst6;
   2426 		} u;
   2427 		struct route ro;
   2428 
   2429 		/*
   2430 		 * Look up the routing table for the
   2431 		 * address, and choose the outgoing interface.
   2432 		 *   XXX: is it a good approach?
   2433 		 */
   2434 		memset(&ro, 0, sizeof(ro));
   2435 		if (IN6_IS_ADDR_V4MAPPED(ia))
   2436 			sockaddr_in_init(&u.dst4, ia4, 0);
   2437 		else
   2438 			sockaddr_in6_init(&u.dst6, ia, 0, 0, 0);
   2439 		error = rtcache_setdst(&ro, &u.dst);
   2440 		if (error != 0)
   2441 			return error;
   2442 		rt = rtcache_init(&ro);
   2443 		*ifp = rt != NULL ?
   2444 		    if_get_byindex(rt->rt_ifp->if_index, psref) : NULL;
   2445 		rtcache_unref(rt, &ro);
   2446 		rtcache_free(&ro);
   2447 	} else {
   2448 		/*
   2449 		 * If the interface is specified, validate it.
   2450 		 */
   2451 		*ifp = if_get_byindex(mreq.ipv6mr_interface, psref);
   2452 		if (*ifp == NULL)
   2453 			return ENXIO;	/* XXX EINVAL? */
   2454 	}
   2455 	if (sizeof(*ia) == l)
   2456 		memcpy(v, ia, l);
   2457 	else
   2458 		memcpy(v, ia4, l);
   2459 	return 0;
   2460 }
   2461 
   2462 /*
   2463  * Set the IP6 multicast options in response to user setsockopt().
   2464  */
   2465 static int
   2466 ip6_setmoptions(const struct sockopt *sopt, struct in6pcb *in6p)
   2467 {
   2468 	int error = 0;
   2469 	u_int loop, ifindex;
   2470 	struct ipv6_mreq mreq;
   2471 	struct in6_addr ia;
   2472 	struct ifnet *ifp;
   2473 	struct ip6_moptions *im6o = in6p->in6p_moptions;
   2474 	struct in6_multi_mship *imm;
   2475 
   2476 	KASSERT(in6p_locked(in6p));
   2477 
   2478 	if (im6o == NULL) {
   2479 		/*
   2480 		 * No multicast option buffer attached to the pcb;
   2481 		 * allocate one and initialize to default values.
   2482 		 */
   2483 		im6o = malloc(sizeof(*im6o), M_IPMOPTS, M_NOWAIT);
   2484 		if (im6o == NULL)
   2485 			return (ENOBUFS);
   2486 		in6p->in6p_moptions = im6o;
   2487 		im6o->im6o_multicast_if_index = 0;
   2488 		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2489 		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
   2490 		LIST_INIT(&im6o->im6o_memberships);
   2491 	}
   2492 
   2493 	switch (sopt->sopt_name) {
   2494 
   2495 	case IPV6_MULTICAST_IF: {
   2496 		int s;
   2497 		/*
   2498 		 * Select the interface for outgoing multicast packets.
   2499 		 */
   2500 		error = sockopt_get(sopt, &ifindex, sizeof(ifindex));
   2501 		if (error != 0)
   2502 			break;
   2503 
   2504 		s = pserialize_read_enter();
   2505 		if (ifindex != 0) {
   2506 			if ((ifp = if_byindex(ifindex)) == NULL) {
   2507 				pserialize_read_exit(s);
   2508 				error = ENXIO;	/* XXX EINVAL? */
   2509 				break;
   2510 			}
   2511 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
   2512 				pserialize_read_exit(s);
   2513 				error = EADDRNOTAVAIL;
   2514 				break;
   2515 			}
   2516 		} else
   2517 			ifp = NULL;
   2518 		im6o->im6o_multicast_if_index = if_get_index(ifp);
   2519 		pserialize_read_exit(s);
   2520 		break;
   2521 	    }
   2522 
   2523 	case IPV6_MULTICAST_HOPS:
   2524 	    {
   2525 		/*
   2526 		 * Set the IP6 hoplimit for outgoing multicast packets.
   2527 		 */
   2528 		int optval;
   2529 
   2530 		error = sockopt_getint(sopt, &optval);
   2531 		if (error != 0)
   2532 			break;
   2533 
   2534 		if (optval < -1 || optval >= 256)
   2535 			error = EINVAL;
   2536 		else if (optval == -1)
   2537 			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2538 		else
   2539 			im6o->im6o_multicast_hlim = optval;
   2540 		break;
   2541 	    }
   2542 
   2543 	case IPV6_MULTICAST_LOOP:
   2544 		/*
   2545 		 * Set the loopback flag for outgoing multicast packets.
   2546 		 * Must be zero or one.
   2547 		 */
   2548 		error = sockopt_get(sopt, &loop, sizeof(loop));
   2549 		if (error != 0)
   2550 			break;
   2551 		if (loop > 1) {
   2552 			error = EINVAL;
   2553 			break;
   2554 		}
   2555 		im6o->im6o_multicast_loop = loop;
   2556 		break;
   2557 
   2558 	case IPV6_JOIN_GROUP: {
   2559 		int bound;
   2560 		struct psref psref;
   2561 		/*
   2562 		 * Add a multicast group membership.
   2563 		 * Group must be a valid IP6 multicast address.
   2564 		 */
   2565 		bound = curlwp_bind();
   2566 		ifp = NULL;
   2567 		error = ip6_get_membership(sopt, &ifp, &psref, &ia, sizeof(ia));
   2568 		if (error != 0) {
   2569 			KASSERT(ifp == NULL);
   2570 			curlwp_bindx(bound);
   2571 			return error;
   2572 		}
   2573 
   2574 		if (IN6_IS_ADDR_V4MAPPED(&ia)) {
   2575 			error = ip_setmoptions(&in6p->in6p_v4moptions, sopt);
   2576 			goto put_break;
   2577 		}
   2578 		/*
   2579 		 * See if we found an interface, and confirm that it
   2580 		 * supports multicast
   2581 		 */
   2582 		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
   2583 			error = EADDRNOTAVAIL;
   2584 			goto put_break;
   2585 		}
   2586 
   2587 		if (in6_setscope(&ia, ifp, NULL)) {
   2588 			error = EADDRNOTAVAIL; /* XXX: should not happen */
   2589 			goto put_break;
   2590 		}
   2591 
   2592 		/*
   2593 		 * See if the membership already exists.
   2594 		 */
   2595 		LIST_FOREACH(imm, &im6o->im6o_memberships, i6mm_chain) {
   2596 			if (imm->i6mm_maddr->in6m_ifp == ifp &&
   2597 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2598 			    &ia))
   2599 				goto put_break;
   2600 		}
   2601 		if (imm != NULL) {
   2602 			error = EADDRINUSE;
   2603 			goto put_break;
   2604 		}
   2605 		/*
   2606 		 * Everything looks good; add a new record to the multicast
   2607 		 * address list for the given interface.
   2608 		 */
   2609 		imm = in6_joingroup(ifp, &ia, &error, 0);
   2610 		if (imm == NULL)
   2611 			goto put_break;
   2612 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
   2613 	    put_break:
   2614 		if_put(ifp, &psref);
   2615 		curlwp_bindx(bound);
   2616 		break;
   2617 	    }
   2618 
   2619 	case IPV6_LEAVE_GROUP:
   2620 		/*
   2621 		 * Drop a multicast group membership.
   2622 		 * Group must be a valid IP6 multicast address.
   2623 		 */
   2624 		error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2625 		if (error != 0)
   2626 			break;
   2627 
   2628 		if (IN6_IS_ADDR_V4MAPPED(&mreq.ipv6mr_multiaddr)) {
   2629 			error = ip_setmoptions(&in6p->in6p_v4moptions, sopt);
   2630 			break;
   2631 		}
   2632 		/*
   2633 		 * If an interface address was specified, get a pointer
   2634 		 * to its ifnet structure.
   2635 		 */
   2636 		if (mreq.ipv6mr_interface != 0) {
   2637 			if ((ifp = if_byindex(mreq.ipv6mr_interface)) == NULL) {
   2638 				error = ENXIO;	/* XXX EINVAL? */
   2639 				break;
   2640 			}
   2641 		} else
   2642 			ifp = NULL;
   2643 
   2644 		/* Fill in the scope zone ID */
   2645 		if (ifp) {
   2646 			if (in6_setscope(&mreq.ipv6mr_multiaddr, ifp, NULL)) {
   2647 				/* XXX: should not happen */
   2648 				error = EADDRNOTAVAIL;
   2649 				break;
   2650 			}
   2651 		} else if (mreq.ipv6mr_interface != 0) {
   2652 			/*
   2653 			 * XXX: This case would happens when the (positive)
   2654 			 * index is in the valid range, but the corresponding
   2655 			 * interface has been detached dynamically.  The above
   2656 			 * check probably avoids such case to happen here, but
   2657 			 * we check it explicitly for safety.
   2658 			 */
   2659 			error = EADDRNOTAVAIL;
   2660 			break;
   2661 		} else {	/* ipv6mr_interface == 0 */
   2662 			struct sockaddr_in6 sa6_mc;
   2663 
   2664 			/*
   2665 			 * The API spec says as follows:
   2666 			 *  If the interface index is specified as 0, the
   2667 			 *  system may choose a multicast group membership to
   2668 			 *  drop by matching the multicast address only.
   2669 			 * On the other hand, we cannot disambiguate the scope
   2670 			 * zone unless an interface is provided.  Thus, we
   2671 			 * check if there's ambiguity with the default scope
   2672 			 * zone as the last resort.
   2673 			 */
   2674 			sockaddr_in6_init(&sa6_mc, &mreq.ipv6mr_multiaddr,
   2675 			    0, 0, 0);
   2676 			error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
   2677 			if (error != 0)
   2678 				break;
   2679 			mreq.ipv6mr_multiaddr = sa6_mc.sin6_addr;
   2680 		}
   2681 
   2682 		/*
   2683 		 * Find the membership in the membership list.
   2684 		 */
   2685 		LIST_FOREACH(imm, &im6o->im6o_memberships, i6mm_chain) {
   2686 			if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
   2687 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2688 			    &mreq.ipv6mr_multiaddr))
   2689 				break;
   2690 		}
   2691 		if (imm == NULL) {
   2692 			/* Unable to resolve interface */
   2693 			error = EADDRNOTAVAIL;
   2694 			break;
   2695 		}
   2696 		/*
   2697 		 * Give up the multicast address record to which the
   2698 		 * membership points.
   2699 		 */
   2700 		LIST_REMOVE(imm, i6mm_chain);
   2701 		in6_leavegroup(imm);
   2702 		break;
   2703 
   2704 	default:
   2705 		error = EOPNOTSUPP;
   2706 		break;
   2707 	}
   2708 
   2709 	/*
   2710 	 * If all options have default values, no need to keep the mbuf.
   2711 	 */
   2712 	if (im6o->im6o_multicast_if_index == 0 &&
   2713 	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
   2714 	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
   2715 	    LIST_EMPTY(&im6o->im6o_memberships)) {
   2716 		free(in6p->in6p_moptions, M_IPMOPTS);
   2717 		in6p->in6p_moptions = NULL;
   2718 	}
   2719 
   2720 	return (error);
   2721 }
   2722 
   2723 /*
   2724  * Return the IP6 multicast options in response to user getsockopt().
   2725  */
   2726 static int
   2727 ip6_getmoptions(struct sockopt *sopt, struct in6pcb *in6p)
   2728 {
   2729 	u_int optval;
   2730 	int error;
   2731 	struct ip6_moptions *im6o = in6p->in6p_moptions;
   2732 
   2733 	switch (sopt->sopt_name) {
   2734 	case IPV6_MULTICAST_IF:
   2735 		if (im6o == NULL || im6o->im6o_multicast_if_index == 0)
   2736 			optval = 0;
   2737 		else
   2738 			optval = im6o->im6o_multicast_if_index;
   2739 
   2740 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2741 		break;
   2742 
   2743 	case IPV6_MULTICAST_HOPS:
   2744 		if (im6o == NULL)
   2745 			optval = ip6_defmcasthlim;
   2746 		else
   2747 			optval = im6o->im6o_multicast_hlim;
   2748 
   2749 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2750 		break;
   2751 
   2752 	case IPV6_MULTICAST_LOOP:
   2753 		if (im6o == NULL)
   2754 			optval = IPV6_DEFAULT_MULTICAST_LOOP;
   2755 		else
   2756 			optval = im6o->im6o_multicast_loop;
   2757 
   2758 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2759 		break;
   2760 
   2761 	default:
   2762 		error = EOPNOTSUPP;
   2763 	}
   2764 
   2765 	return (error);
   2766 }
   2767 
   2768 /*
   2769  * Discard the IP6 multicast options.
   2770  */
   2771 void
   2772 ip6_freemoptions(struct ip6_moptions *im6o)
   2773 {
   2774 	struct in6_multi_mship *imm, *nimm;
   2775 
   2776 	if (im6o == NULL)
   2777 		return;
   2778 
   2779 	/* The owner of im6o (in6p) should be protected by solock */
   2780 	LIST_FOREACH_SAFE(imm, &im6o->im6o_memberships, i6mm_chain, nimm) {
   2781 		LIST_REMOVE(imm, i6mm_chain);
   2782 		in6_leavegroup(imm);
   2783 	}
   2784 	free(im6o, M_IPMOPTS);
   2785 }
   2786 
   2787 /*
   2788  * Set IPv6 outgoing packet options based on advanced API.
   2789  */
   2790 int
   2791 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
   2792 	struct ip6_pktopts *stickyopt, kauth_cred_t cred, int uproto)
   2793 {
   2794 	struct cmsghdr *cm = 0;
   2795 
   2796 	if (control == NULL || opt == NULL)
   2797 		return (EINVAL);
   2798 
   2799 	ip6_initpktopts(opt);
   2800 	if (stickyopt) {
   2801 		int error;
   2802 
   2803 		/*
   2804 		 * If stickyopt is provided, make a local copy of the options
   2805 		 * for this particular packet, then override them by ancillary
   2806 		 * objects.
   2807 		 * XXX: copypktopts() does not copy the cached route to a next
   2808 		 * hop (if any).  This is not very good in terms of efficiency,
   2809 		 * but we can allow this since this option should be rarely
   2810 		 * used.
   2811 		 */
   2812 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
   2813 			return (error);
   2814 	}
   2815 
   2816 	/*
   2817 	 * XXX: Currently, we assume all the optional information is stored
   2818 	 * in a single mbuf.
   2819 	 */
   2820 	if (control->m_next)
   2821 		return (EINVAL);
   2822 
   2823 	/* XXX if cm->cmsg_len is not aligned, control->m_len can become <0 */
   2824 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
   2825 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
   2826 		int error;
   2827 
   2828 		if (control->m_len < CMSG_LEN(0))
   2829 			return (EINVAL);
   2830 
   2831 		cm = mtod(control, struct cmsghdr *);
   2832 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
   2833 			return (EINVAL);
   2834 		if (cm->cmsg_level != IPPROTO_IPV6)
   2835 			continue;
   2836 
   2837 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
   2838 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
   2839 		if (error)
   2840 			return (error);
   2841 	}
   2842 
   2843 	return (0);
   2844 }
   2845 
   2846 /*
   2847  * Set a particular packet option, as a sticky option or an ancillary data
   2848  * item.  "len" can be 0 only when it's a sticky option.
   2849  * We have 4 cases of combination of "sticky" and "cmsg":
   2850  * "sticky=0, cmsg=0": impossible
   2851  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
   2852  * "sticky=1, cmsg=0": RFC3542 socket option
   2853  * "sticky=1, cmsg=1": RFC2292 socket option
   2854  */
   2855 static int
   2856 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
   2857     kauth_cred_t cred, int sticky, int cmsg, int uproto)
   2858 {
   2859 	int minmtupolicy;
   2860 	int error;
   2861 
   2862 	if (!sticky && !cmsg) {
   2863 #ifdef DIAGNOSTIC
   2864 		printf("ip6_setpktopt: impossible case\n");
   2865 #endif
   2866 		return (EINVAL);
   2867 	}
   2868 
   2869 	/*
   2870 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
   2871 	 * not be specified in the context of RFC3542.  Conversely,
   2872 	 * RFC3542 types should not be specified in the context of RFC2292.
   2873 	 */
   2874 	if (!cmsg) {
   2875 		switch (optname) {
   2876 		case IPV6_2292PKTINFO:
   2877 		case IPV6_2292HOPLIMIT:
   2878 		case IPV6_2292NEXTHOP:
   2879 		case IPV6_2292HOPOPTS:
   2880 		case IPV6_2292DSTOPTS:
   2881 		case IPV6_2292RTHDR:
   2882 		case IPV6_2292PKTOPTIONS:
   2883 			return (ENOPROTOOPT);
   2884 		}
   2885 	}
   2886 	if (sticky && cmsg) {
   2887 		switch (optname) {
   2888 		case IPV6_PKTINFO:
   2889 		case IPV6_HOPLIMIT:
   2890 		case IPV6_NEXTHOP:
   2891 		case IPV6_HOPOPTS:
   2892 		case IPV6_DSTOPTS:
   2893 		case IPV6_RTHDRDSTOPTS:
   2894 		case IPV6_RTHDR:
   2895 		case IPV6_USE_MIN_MTU:
   2896 		case IPV6_DONTFRAG:
   2897 		case IPV6_OTCLASS:
   2898 		case IPV6_TCLASS:
   2899 		case IPV6_PREFER_TEMPADDR: /* XXX not an RFC3542 option */
   2900 			return (ENOPROTOOPT);
   2901 		}
   2902 	}
   2903 
   2904 	switch (optname) {
   2905 #ifdef RFC2292
   2906 	case IPV6_2292PKTINFO:
   2907 #endif
   2908 	case IPV6_PKTINFO:
   2909 	{
   2910 		struct in6_pktinfo *pktinfo;
   2911 
   2912 		if (len != sizeof(struct in6_pktinfo))
   2913 			return (EINVAL);
   2914 
   2915 		pktinfo = (struct in6_pktinfo *)buf;
   2916 
   2917 		/*
   2918 		 * An application can clear any sticky IPV6_PKTINFO option by
   2919 		 * doing a "regular" setsockopt with ipi6_addr being
   2920 		 * in6addr_any and ipi6_ifindex being zero.
   2921 		 * [RFC 3542, Section 6]
   2922 		 */
   2923 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
   2924 		    pktinfo->ipi6_ifindex == 0 &&
   2925 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2926 			ip6_clearpktopts(opt, optname);
   2927 			break;
   2928 		}
   2929 
   2930 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
   2931 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2932 			return (EINVAL);
   2933 		}
   2934 
   2935 		/* Validate the interface index if specified. */
   2936 		if (pktinfo->ipi6_ifindex) {
   2937 			struct ifnet *ifp;
   2938 			int s = pserialize_read_enter();
   2939 			ifp = if_byindex(pktinfo->ipi6_ifindex);
   2940 			if (ifp == NULL) {
   2941 				pserialize_read_exit(s);
   2942 				return ENXIO;
   2943 			}
   2944 			pserialize_read_exit(s);
   2945 		}
   2946 
   2947 		/*
   2948 		 * We store the address anyway, and let in6_selectsrc()
   2949 		 * validate the specified address.  This is because ipi6_addr
   2950 		 * may not have enough information about its scope zone, and
   2951 		 * we may need additional information (such as outgoing
   2952 		 * interface or the scope zone of a destination address) to
   2953 		 * disambiguate the scope.
   2954 		 * XXX: the delay of the validation may confuse the
   2955 		 * application when it is used as a sticky option.
   2956 		 */
   2957 		if (opt->ip6po_pktinfo == NULL) {
   2958 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
   2959 			    M_IP6OPT, M_NOWAIT);
   2960 			if (opt->ip6po_pktinfo == NULL)
   2961 				return (ENOBUFS);
   2962 		}
   2963 		memcpy(opt->ip6po_pktinfo, pktinfo, sizeof(*pktinfo));
   2964 		break;
   2965 	}
   2966 
   2967 #ifdef RFC2292
   2968 	case IPV6_2292HOPLIMIT:
   2969 #endif
   2970 	case IPV6_HOPLIMIT:
   2971 	{
   2972 		int *hlimp;
   2973 
   2974 		/*
   2975 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
   2976 		 * to simplify the ordering among hoplimit options.
   2977 		 */
   2978 		if (optname == IPV6_HOPLIMIT && sticky)
   2979 			return (ENOPROTOOPT);
   2980 
   2981 		if (len != sizeof(int))
   2982 			return (EINVAL);
   2983 		hlimp = (int *)buf;
   2984 		if (*hlimp < -1 || *hlimp > 255)
   2985 			return (EINVAL);
   2986 
   2987 		opt->ip6po_hlim = *hlimp;
   2988 		break;
   2989 	}
   2990 
   2991 	case IPV6_OTCLASS:
   2992 		if (len != sizeof(u_int8_t))
   2993 			return (EINVAL);
   2994 
   2995 		opt->ip6po_tclass = *(u_int8_t *)buf;
   2996 		break;
   2997 
   2998 	case IPV6_TCLASS:
   2999 	{
   3000 		int tclass;
   3001 
   3002 		if (len != sizeof(int))
   3003 			return (EINVAL);
   3004 		tclass = *(int *)buf;
   3005 		if (tclass < -1 || tclass > 255)
   3006 			return (EINVAL);
   3007 
   3008 		opt->ip6po_tclass = tclass;
   3009 		break;
   3010 	}
   3011 
   3012 #ifdef RFC2292
   3013 	case IPV6_2292NEXTHOP:
   3014 #endif
   3015 	case IPV6_NEXTHOP:
   3016 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3017 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3018 		if (error)
   3019 			return (error);
   3020 
   3021 		if (len == 0) {	/* just remove the option */
   3022 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3023 			break;
   3024 		}
   3025 
   3026 		/* check if cmsg_len is large enough for sa_len */
   3027 		if (len < sizeof(struct sockaddr) || len < *buf)
   3028 			return (EINVAL);
   3029 
   3030 		switch (((struct sockaddr *)buf)->sa_family) {
   3031 		case AF_INET6:
   3032 		{
   3033 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
   3034 
   3035 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
   3036 				return (EINVAL);
   3037 
   3038 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
   3039 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
   3040 				return (EINVAL);
   3041 			}
   3042 			if ((error = sa6_embedscope(sa6, ip6_use_defzone))
   3043 			    != 0) {
   3044 				return (error);
   3045 			}
   3046 			break;
   3047 		}
   3048 		case AF_LINK:	/* eventually be supported? */
   3049 		default:
   3050 			return (EAFNOSUPPORT);
   3051 		}
   3052 
   3053 		/* turn off the previous option, then set the new option. */
   3054 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3055 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
   3056 		if (opt->ip6po_nexthop == NULL)
   3057 			return (ENOBUFS);
   3058 		memcpy(opt->ip6po_nexthop, buf, *buf);
   3059 		break;
   3060 
   3061 #ifdef RFC2292
   3062 	case IPV6_2292HOPOPTS:
   3063 #endif
   3064 	case IPV6_HOPOPTS:
   3065 	{
   3066 		struct ip6_hbh *hbh;
   3067 		int hbhlen;
   3068 
   3069 		/*
   3070 		 * XXX: We don't allow a non-privileged user to set ANY HbH
   3071 		 * options, since per-option restriction has too much
   3072 		 * overhead.
   3073 		 */
   3074 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3075 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3076 		if (error)
   3077 			return (error);
   3078 
   3079 		if (len == 0) {
   3080 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3081 			break;	/* just remove the option */
   3082 		}
   3083 
   3084 		/* message length validation */
   3085 		if (len < sizeof(struct ip6_hbh))
   3086 			return (EINVAL);
   3087 		hbh = (struct ip6_hbh *)buf;
   3088 		hbhlen = (hbh->ip6h_len + 1) << 3;
   3089 		if (len != hbhlen)
   3090 			return (EINVAL);
   3091 
   3092 		/* turn off the previous option, then set the new option. */
   3093 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3094 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
   3095 		if (opt->ip6po_hbh == NULL)
   3096 			return (ENOBUFS);
   3097 		memcpy(opt->ip6po_hbh, hbh, hbhlen);
   3098 
   3099 		break;
   3100 	}
   3101 
   3102 #ifdef RFC2292
   3103 	case IPV6_2292DSTOPTS:
   3104 #endif
   3105 	case IPV6_DSTOPTS:
   3106 	case IPV6_RTHDRDSTOPTS:
   3107 	{
   3108 		struct ip6_dest *dest, **newdest = NULL;
   3109 		int destlen;
   3110 
   3111 		/* XXX: see the comment for IPV6_HOPOPTS */
   3112 		error = kauth_authorize_network(cred, KAUTH_NETWORK_IPV6,
   3113 		    KAUTH_REQ_NETWORK_IPV6_HOPBYHOP, NULL, NULL, NULL);
   3114 		if (error)
   3115 			return (error);
   3116 
   3117 		if (len == 0) {
   3118 			ip6_clearpktopts(opt, optname);
   3119 			break;	/* just remove the option */
   3120 		}
   3121 
   3122 		/* message length validation */
   3123 		if (len < sizeof(struct ip6_dest))
   3124 			return (EINVAL);
   3125 		dest = (struct ip6_dest *)buf;
   3126 		destlen = (dest->ip6d_len + 1) << 3;
   3127 		if (len != destlen)
   3128 			return (EINVAL);
   3129 		/*
   3130 		 * Determine the position that the destination options header
   3131 		 * should be inserted; before or after the routing header.
   3132 		 */
   3133 		switch (optname) {
   3134 		case IPV6_2292DSTOPTS:
   3135 			/*
   3136 			 * The old advanced API is ambiguous on this point.
   3137 			 * Our approach is to determine the position based
   3138 			 * according to the existence of a routing header.
   3139 			 * Note, however, that this depends on the order of the
   3140 			 * extension headers in the ancillary data; the 1st
   3141 			 * part of the destination options header must appear
   3142 			 * before the routing header in the ancillary data,
   3143 			 * too.
   3144 			 * RFC3542 solved the ambiguity by introducing
   3145 			 * separate ancillary data or option types.
   3146 			 */
   3147 			if (opt->ip6po_rthdr == NULL)
   3148 				newdest = &opt->ip6po_dest1;
   3149 			else
   3150 				newdest = &opt->ip6po_dest2;
   3151 			break;
   3152 		case IPV6_RTHDRDSTOPTS:
   3153 			newdest = &opt->ip6po_dest1;
   3154 			break;
   3155 		case IPV6_DSTOPTS:
   3156 			newdest = &opt->ip6po_dest2;
   3157 			break;
   3158 		}
   3159 
   3160 		/* turn off the previous option, then set the new option. */
   3161 		ip6_clearpktopts(opt, optname);
   3162 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
   3163 		if (*newdest == NULL)
   3164 			return (ENOBUFS);
   3165 		memcpy(*newdest, dest, destlen);
   3166 
   3167 		break;
   3168 	}
   3169 
   3170 #ifdef RFC2292
   3171 	case IPV6_2292RTHDR:
   3172 #endif
   3173 	case IPV6_RTHDR:
   3174 	{
   3175 		struct ip6_rthdr *rth;
   3176 		int rthlen;
   3177 
   3178 		if (len == 0) {
   3179 			ip6_clearpktopts(opt, IPV6_RTHDR);
   3180 			break;	/* just remove the option */
   3181 		}
   3182 
   3183 		/* message length validation */
   3184 		if (len < sizeof(struct ip6_rthdr))
   3185 			return (EINVAL);
   3186 		rth = (struct ip6_rthdr *)buf;
   3187 		rthlen = (rth->ip6r_len + 1) << 3;
   3188 		if (len != rthlen)
   3189 			return (EINVAL);
   3190 		switch (rth->ip6r_type) {
   3191 		case IPV6_RTHDR_TYPE_0:
   3192 			if (rth->ip6r_len == 0)	/* must contain one addr */
   3193 				return (EINVAL);
   3194 			if (rth->ip6r_len % 2) /* length must be even */
   3195 				return (EINVAL);
   3196 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
   3197 				return (EINVAL);
   3198 			break;
   3199 		default:
   3200 			return (EINVAL);	/* not supported */
   3201 		}
   3202 		/* turn off the previous option */
   3203 		ip6_clearpktopts(opt, IPV6_RTHDR);
   3204 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
   3205 		if (opt->ip6po_rthdr == NULL)
   3206 			return (ENOBUFS);
   3207 		memcpy(opt->ip6po_rthdr, rth, rthlen);
   3208 		break;
   3209 	}
   3210 
   3211 	case IPV6_USE_MIN_MTU:
   3212 		if (len != sizeof(int))
   3213 			return (EINVAL);
   3214 		minmtupolicy = *(int *)buf;
   3215 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
   3216 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
   3217 		    minmtupolicy != IP6PO_MINMTU_ALL) {
   3218 			return (EINVAL);
   3219 		}
   3220 		opt->ip6po_minmtu = minmtupolicy;
   3221 		break;
   3222 
   3223 	case IPV6_DONTFRAG:
   3224 		if (len != sizeof(int))
   3225 			return (EINVAL);
   3226 
   3227 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
   3228 			/*
   3229 			 * we ignore this option for TCP sockets.
   3230 			 * (RFC3542 leaves this case unspecified.)
   3231 			 */
   3232 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
   3233 		} else
   3234 			opt->ip6po_flags |= IP6PO_DONTFRAG;
   3235 		break;
   3236 
   3237 	case IPV6_PREFER_TEMPADDR:
   3238 	{
   3239 		int preftemp;
   3240 
   3241 		if (len != sizeof(int))
   3242 			return (EINVAL);
   3243 		preftemp = *(int *)buf;
   3244 		switch (preftemp) {
   3245 		case IP6PO_TEMPADDR_SYSTEM:
   3246 		case IP6PO_TEMPADDR_NOTPREFER:
   3247 		case IP6PO_TEMPADDR_PREFER:
   3248 			break;
   3249 		default:
   3250 			return (EINVAL);
   3251 		}
   3252 		opt->ip6po_prefer_tempaddr = preftemp;
   3253 		break;
   3254 	}
   3255 
   3256 	default:
   3257 		return (ENOPROTOOPT);
   3258 	} /* end of switch */
   3259 
   3260 	return (0);
   3261 }
   3262 
   3263 /*
   3264  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
   3265  * packet to the input queue of a specified interface.  Note that this
   3266  * calls the output routine of the loopback "driver", but with an interface
   3267  * pointer that might NOT be lo0ifp -- easier than replicating that code here.
   3268  */
   3269 void
   3270 ip6_mloopback(struct ifnet *ifp, struct mbuf *m,
   3271 	const struct sockaddr_in6 *dst)
   3272 {
   3273 	struct mbuf *copym;
   3274 	struct ip6_hdr *ip6;
   3275 
   3276 	copym = m_copy(m, 0, M_COPYALL);
   3277 	if (copym == NULL)
   3278 		return;
   3279 
   3280 	/*
   3281 	 * Make sure to deep-copy IPv6 header portion in case the data
   3282 	 * is in an mbuf cluster, so that we can safely override the IPv6
   3283 	 * header portion later.
   3284 	 */
   3285 	if ((copym->m_flags & M_EXT) != 0 ||
   3286 	    copym->m_len < sizeof(struct ip6_hdr)) {
   3287 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
   3288 		if (copym == NULL)
   3289 			return;
   3290 	}
   3291 
   3292 #ifdef DIAGNOSTIC
   3293 	if (copym->m_len < sizeof(*ip6)) {
   3294 		m_freem(copym);
   3295 		return;
   3296 	}
   3297 #endif
   3298 
   3299 	ip6 = mtod(copym, struct ip6_hdr *);
   3300 	/*
   3301 	 * clear embedded scope identifiers if necessary.
   3302 	 * in6_clearscope will touch the addresses only when necessary.
   3303 	 */
   3304 	in6_clearscope(&ip6->ip6_src);
   3305 	in6_clearscope(&ip6->ip6_dst);
   3306 
   3307 	(void)looutput(ifp, copym, (const struct sockaddr *)dst, NULL);
   3308 }
   3309 
   3310 /*
   3311  * Chop IPv6 header off from the payload.
   3312  */
   3313 static int
   3314 ip6_splithdr(struct mbuf *m,  struct ip6_exthdrs *exthdrs)
   3315 {
   3316 	struct mbuf *mh;
   3317 	struct ip6_hdr *ip6;
   3318 
   3319 	ip6 = mtod(m, struct ip6_hdr *);
   3320 	if (m->m_len > sizeof(*ip6)) {
   3321 		MGETHDR(mh, M_DONTWAIT, MT_HEADER);
   3322 		if (mh == 0) {
   3323 			m_freem(m);
   3324 			return ENOBUFS;
   3325 		}
   3326 		M_MOVE_PKTHDR(mh, m);
   3327 		MH_ALIGN(mh, sizeof(*ip6));
   3328 		m->m_len -= sizeof(*ip6);
   3329 		m->m_data += sizeof(*ip6);
   3330 		mh->m_next = m;
   3331 		m = mh;
   3332 		m->m_len = sizeof(*ip6);
   3333 		bcopy((void *)ip6, mtod(m, void *), sizeof(*ip6));
   3334 	}
   3335 	exthdrs->ip6e_ip6 = m;
   3336 	return 0;
   3337 }
   3338 
   3339 /*
   3340  * Compute IPv6 extension header length.
   3341  */
   3342 int
   3343 ip6_optlen(struct in6pcb *in6p)
   3344 {
   3345 	int len;
   3346 
   3347 	if (!in6p->in6p_outputopts)
   3348 		return 0;
   3349 
   3350 	len = 0;
   3351 #define elen(x) \
   3352     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
   3353 
   3354 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
   3355 	len += elen(in6p->in6p_outputopts->ip6po_dest1);
   3356 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
   3357 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
   3358 	return len;
   3359 #undef elen
   3360 }
   3361 
   3362 /*
   3363  * Ensure sending address is valid.
   3364  * Returns 0 on success, -1 if an error should be sent back or 1
   3365  * if the packet could be dropped without error (protocol dependent).
   3366  */
   3367 static int
   3368 ip6_ifaddrvalid(const struct in6_addr *src, const struct in6_addr *dst)
   3369 {
   3370 	struct sockaddr_in6 sin6;
   3371 	int s, error;
   3372 	struct ifaddr *ifa;
   3373 	struct in6_ifaddr *ia6;
   3374 
   3375 	if (IN6_IS_ADDR_UNSPECIFIED(src))
   3376 		return 0;
   3377 
   3378 	memset(&sin6, 0, sizeof(sin6));
   3379 	sin6.sin6_family = AF_INET6;
   3380 	sin6.sin6_len = sizeof(sin6);
   3381 	sin6.sin6_addr = *src;
   3382 
   3383 	s = pserialize_read_enter();
   3384 	ifa = ifa_ifwithaddr(sin6tosa(&sin6));
   3385 	if ((ia6 = ifatoia6(ifa)) == NULL ||
   3386 	    ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_DUPLICATED))
   3387 		error = -1;
   3388 	else if (ia6->ia6_flags & IN6_IFF_TENTATIVE)
   3389 		error = 1;
   3390 	else if (ia6->ia6_flags & IN6_IFF_DETACHED &&
   3391 	    (sin6.sin6_addr = *dst, ifa_ifwithaddr(sin6tosa(&sin6)) == NULL))
   3392 		/* Allow internal traffic to DETACHED addresses */
   3393 		error = 1;
   3394 	else
   3395 		error = 0;
   3396 	pserialize_read_exit(s);
   3397 
   3398 	return error;
   3399 }
   3400