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ip6_output.c revision 1.141
      1 /*	$NetBSD: ip6_output.c,v 1.141 2011/12/19 11:59:58 drochner 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 1.141 2011/12/19 11:59:58 drochner Exp $");
     66 
     67 #include "opt_inet.h"
     68 #include "opt_inet6.h"
     69 #include "opt_ipsec.h"
     70 #include "opt_pfil_hooks.h"
     71 
     72 #include <sys/param.h>
     73 #include <sys/malloc.h>
     74 #include <sys/mbuf.h>
     75 #include <sys/errno.h>
     76 #include <sys/protosw.h>
     77 #include <sys/socket.h>
     78 #include <sys/socketvar.h>
     79 #include <sys/systm.h>
     80 #include <sys/proc.h>
     81 #include <sys/kauth.h>
     82 
     83 #include <net/if.h>
     84 #include <net/route.h>
     85 #ifdef PFIL_HOOKS
     86 #include <net/pfil.h>
     87 #endif
     88 
     89 #include <netinet/in.h>
     90 #include <netinet/in_var.h>
     91 #include <netinet/ip6.h>
     92 #include <netinet/icmp6.h>
     93 #include <netinet/in_offload.h>
     94 #include <netinet6/in6_offload.h>
     95 #include <netinet6/ip6_var.h>
     96 #include <netinet6/ip6_private.h>
     97 #include <netinet6/in6_pcb.h>
     98 #include <netinet6/nd6.h>
     99 #include <netinet6/ip6protosw.h>
    100 #include <netinet6/scope6_var.h>
    101 
    102 #ifdef KAME_IPSEC
    103 #include <netinet6/ipsec.h>
    104 #include <netinet6/ipsec_private.h>
    105 #include <netkey/key.h>
    106 #endif /* KAME_IPSEC */
    107 
    108 #ifdef FAST_IPSEC
    109 #include <netipsec/ipsec.h>
    110 #include <netipsec/ipsec6.h>
    111 #include <netipsec/key.h>
    112 #include <netipsec/xform.h>
    113 #endif
    114 
    115 
    116 #include <net/net_osdep.h>
    117 
    118 #ifdef PFIL_HOOKS
    119 extern struct pfil_head inet6_pfil_hook;	/* XXX */
    120 #endif
    121 
    122 struct ip6_exthdrs {
    123 	struct mbuf *ip6e_ip6;
    124 	struct mbuf *ip6e_hbh;
    125 	struct mbuf *ip6e_dest1;
    126 	struct mbuf *ip6e_rthdr;
    127 	struct mbuf *ip6e_dest2;
    128 };
    129 
    130 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
    131 	kauth_cred_t, int);
    132 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
    133 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *, kauth_cred_t,
    134 	int, int, int);
    135 static int ip6_setmoptions(const struct sockopt *, struct ip6_moptions **);
    136 static int ip6_getmoptions(struct sockopt *, struct ip6_moptions *);
    137 static int ip6_copyexthdr(struct mbuf **, void *, int);
    138 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
    139 	struct ip6_frag **);
    140 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
    141 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
    142 static int ip6_getpmtu(struct route *, struct route *, struct ifnet *,
    143     const struct in6_addr *, u_long *, int *);
    144 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
    145 
    146 #ifdef RFC2292
    147 static int ip6_pcbopts(struct ip6_pktopts **, struct socket *, struct sockopt *);
    148 #endif
    149 
    150 /*
    151  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
    152  * header (with pri, len, nxt, hlim, src, dst).
    153  * This function may modify ver and hlim only.
    154  * The mbuf chain containing the packet will be freed.
    155  * The mbuf opt, if present, will not be freed.
    156  *
    157  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
    158  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
    159  * which is rt_rmx.rmx_mtu.
    160  */
    161 int
    162 ip6_output(
    163     struct mbuf *m0,
    164     struct ip6_pktopts *opt,
    165     struct route *ro,
    166     int flags,
    167     struct ip6_moptions *im6o,
    168     struct socket *so,
    169     struct ifnet **ifpp		/* XXX: just for statistics */
    170 )
    171 {
    172 	struct ip6_hdr *ip6, *mhip6;
    173 	struct ifnet *ifp, *origifp;
    174 	struct mbuf *m = m0;
    175 	int hlen, tlen, len, off;
    176 	bool tso;
    177 	struct route ip6route;
    178 	struct rtentry *rt = NULL;
    179 	const struct sockaddr_in6 *dst = NULL;
    180 	struct sockaddr_in6 src_sa, dst_sa;
    181 	int error = 0;
    182 	struct in6_ifaddr *ia = NULL;
    183 	u_long mtu;
    184 	int alwaysfrag, dontfrag;
    185 	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
    186 	struct ip6_exthdrs exthdrs;
    187 	struct in6_addr finaldst, src0, dst0;
    188 	u_int32_t zone;
    189 	struct route *ro_pmtu = NULL;
    190 	int hdrsplit = 0;
    191 	int needipsec = 0;
    192 #ifdef KAME_IPSEC
    193 	int needipsectun = 0;
    194 	struct secpolicy *sp = NULL;
    195 
    196 	ip6 = mtod(m, struct ip6_hdr *);
    197 #endif /* KAME_IPSEC */
    198 #ifdef FAST_IPSEC
    199 	struct secpolicy *sp = NULL;
    200 	int s;
    201 #endif
    202 
    203 	memset(&ip6route, 0, sizeof(ip6route));
    204 
    205 #ifdef  DIAGNOSTIC
    206 	if ((m->m_flags & M_PKTHDR) == 0)
    207 		panic("ip6_output: no HDR");
    208 
    209 	if ((m->m_pkthdr.csum_flags &
    210 	    (M_CSUM_TCPv4|M_CSUM_UDPv4|M_CSUM_TSOv4)) != 0) {
    211 		panic("ip6_output: IPv4 checksum offload flags: %d",
    212 		    m->m_pkthdr.csum_flags);
    213 	}
    214 
    215 	if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) ==
    216 	    (M_CSUM_TCPv6|M_CSUM_UDPv6)) {
    217 		panic("ip6_output: conflicting checksum offload flags: %d",
    218 		    m->m_pkthdr.csum_flags);
    219 	}
    220 #endif
    221 
    222 	M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data, sizeof(struct ip6_hdr));
    223 
    224 #define MAKE_EXTHDR(hp, mp)						\
    225     do {								\
    226 	if (hp) {							\
    227 		struct ip6_ext *eh = (struct ip6_ext *)(hp);		\
    228 		error = ip6_copyexthdr((mp), (void *)(hp), 		\
    229 		    ((eh)->ip6e_len + 1) << 3);				\
    230 		if (error)						\
    231 			goto freehdrs;					\
    232 	}								\
    233     } while (/*CONSTCOND*/ 0)
    234 
    235 	memset(&exthdrs, 0, sizeof(exthdrs));
    236 	if (opt) {
    237 		/* Hop-by-Hop options header */
    238 		MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
    239 		/* Destination options header(1st part) */
    240 		MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
    241 		/* Routing header */
    242 		MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
    243 		/* Destination options header(2nd part) */
    244 		MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
    245 	}
    246 
    247 #ifdef KAME_IPSEC
    248 	if ((flags & IPV6_FORWARDING) != 0) {
    249 		needipsec = 0;
    250 		goto skippolicycheck;
    251 	}
    252 
    253 	/* get a security policy for this packet */
    254 	if (so == NULL)
    255 		sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
    256 	else {
    257 		if (IPSEC_PCB_SKIP_IPSEC(sotoinpcb_hdr(so)->inph_sp,
    258 					 IPSEC_DIR_OUTBOUND)) {
    259 			needipsec = 0;
    260 			goto skippolicycheck;
    261 		}
    262 		sp = ipsec6_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
    263 	}
    264 
    265 	if (sp == NULL) {
    266 		IPSEC6_STATINC(IPSEC_STAT_OUT_INVAL);
    267 		goto freehdrs;
    268 	}
    269 
    270 	error = 0;
    271 
    272 	/* check policy */
    273 	switch (sp->policy) {
    274 	case IPSEC_POLICY_DISCARD:
    275 		/*
    276 		 * This packet is just discarded.
    277 		 */
    278 		IPSEC6_STATINC(IPSEC_STAT_OUT_POLVIO);
    279 		goto freehdrs;
    280 
    281 	case IPSEC_POLICY_BYPASS:
    282 	case IPSEC_POLICY_NONE:
    283 		/* no need to do IPsec. */
    284 		needipsec = 0;
    285 		break;
    286 
    287 	case IPSEC_POLICY_IPSEC:
    288 		if (sp->req == NULL) {
    289 			/* XXX should be panic ? */
    290 			printf("ip6_output: No IPsec request specified.\n");
    291 			error = EINVAL;
    292 			goto freehdrs;
    293 		}
    294 		needipsec = 1;
    295 		break;
    296 
    297 	case IPSEC_POLICY_ENTRUST:
    298 	default:
    299 		printf("ip6_output: Invalid policy found. %d\n", sp->policy);
    300 	}
    301 
    302   skippolicycheck:;
    303 #endif /* KAME_IPSEC */
    304 
    305 	/*
    306 	 * Calculate the total length of the extension header chain.
    307 	 * Keep the length of the unfragmentable part for fragmentation.
    308 	 */
    309 	optlen = 0;
    310 	if (exthdrs.ip6e_hbh) optlen += exthdrs.ip6e_hbh->m_len;
    311 	if (exthdrs.ip6e_dest1) optlen += exthdrs.ip6e_dest1->m_len;
    312 	if (exthdrs.ip6e_rthdr) optlen += exthdrs.ip6e_rthdr->m_len;
    313 	unfragpartlen = optlen + sizeof(struct ip6_hdr);
    314 	/* NOTE: we don't add AH/ESP length here. do that later. */
    315 	if (exthdrs.ip6e_dest2) optlen += exthdrs.ip6e_dest2->m_len;
    316 
    317 #ifdef FAST_IPSEC
    318 	/* Check the security policy (SP) for the packet */
    319 
    320 	/* XXX For moment, we doesn't support packet with extented action */
    321 	if (optlen !=0)
    322 		goto freehdrs;
    323 
    324 	sp = ipsec6_check_policy(m,so,flags,&needipsec,&error);
    325 	if (error != 0) {
    326 		/*
    327 		 * Hack: -EINVAL is used to signal that a packet
    328 		 * should be silently discarded.  This is typically
    329 		 * because we asked key management for an SA and
    330 		 * it was delayed (e.g. kicked up to IKE).
    331 		 */
    332 	if (error == -EINVAL)
    333 		error = 0;
    334 	goto freehdrs;
    335     }
    336 #endif /* FAST_IPSEC */
    337 
    338 
    339 	if (needipsec &&
    340 	    (m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    341 		in6_delayed_cksum(m);
    342 		m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    343 	}
    344 
    345 
    346 	/*
    347 	 * If we need IPsec, or there is at least one extension header,
    348 	 * separate IP6 header from the payload.
    349 	 */
    350 	if ((needipsec || optlen) && !hdrsplit) {
    351 		if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    352 			m = NULL;
    353 			goto freehdrs;
    354 		}
    355 		m = exthdrs.ip6e_ip6;
    356 		hdrsplit++;
    357 	}
    358 
    359 	/* adjust pointer */
    360 	ip6 = mtod(m, struct ip6_hdr *);
    361 
    362 	/* adjust mbuf packet header length */
    363 	m->m_pkthdr.len += optlen;
    364 	plen = m->m_pkthdr.len - sizeof(*ip6);
    365 
    366 	/* If this is a jumbo payload, insert a jumbo payload option. */
    367 	if (plen > IPV6_MAXPACKET) {
    368 		if (!hdrsplit) {
    369 			if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
    370 				m = NULL;
    371 				goto freehdrs;
    372 			}
    373 			m = exthdrs.ip6e_ip6;
    374 			hdrsplit++;
    375 		}
    376 		/* adjust pointer */
    377 		ip6 = mtod(m, struct ip6_hdr *);
    378 		if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
    379 			goto freehdrs;
    380 		optlen += 8; /* XXX JUMBOOPTLEN */
    381 		ip6->ip6_plen = 0;
    382 	} else
    383 		ip6->ip6_plen = htons(plen);
    384 
    385 	/*
    386 	 * Concatenate headers and fill in next header fields.
    387 	 * Here we have, on "m"
    388 	 *	IPv6 payload
    389 	 * and we insert headers accordingly.  Finally, we should be getting:
    390 	 *	IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
    391 	 *
    392 	 * during the header composing process, "m" points to IPv6 header.
    393 	 * "mprev" points to an extension header prior to esp.
    394 	 */
    395 	{
    396 		u_char *nexthdrp = &ip6->ip6_nxt;
    397 		struct mbuf *mprev = m;
    398 
    399 		/*
    400 		 * we treat dest2 specially.  this makes IPsec processing
    401 		 * much easier.  the goal here is to make mprev point the
    402 		 * mbuf prior to dest2.
    403 		 *
    404 		 * result: IPv6 dest2 payload
    405 		 * m and mprev will point to IPv6 header.
    406 		 */
    407 		if (exthdrs.ip6e_dest2) {
    408 			if (!hdrsplit)
    409 				panic("assumption failed: hdr not split");
    410 			exthdrs.ip6e_dest2->m_next = m->m_next;
    411 			m->m_next = exthdrs.ip6e_dest2;
    412 			*mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
    413 			ip6->ip6_nxt = IPPROTO_DSTOPTS;
    414 		}
    415 
    416 #define MAKE_CHAIN(m, mp, p, i)\
    417     do {\
    418 	if (m) {\
    419 		if (!hdrsplit) \
    420 			panic("assumption failed: hdr not split"); \
    421 		*mtod((m), u_char *) = *(p);\
    422 		*(p) = (i);\
    423 		p = mtod((m), u_char *);\
    424 		(m)->m_next = (mp)->m_next;\
    425 		(mp)->m_next = (m);\
    426 		(mp) = (m);\
    427 	}\
    428     } while (/*CONSTCOND*/ 0)
    429 		/*
    430 		 * result: IPv6 hbh dest1 rthdr dest2 payload
    431 		 * m will point to IPv6 header.  mprev will point to the
    432 		 * extension header prior to dest2 (rthdr in the above case).
    433 		 */
    434 		MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
    435 		MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
    436 		    IPPROTO_DSTOPTS);
    437 		MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
    438 		    IPPROTO_ROUTING);
    439 
    440 		M_CSUM_DATA_IPv6_HL_SET(m->m_pkthdr.csum_data,
    441 		    sizeof(struct ip6_hdr) + optlen);
    442 
    443 #ifdef KAME_IPSEC
    444 		if (!needipsec)
    445 			goto skip_ipsec2;
    446 
    447 		/*
    448 		 * pointers after IPsec headers are not valid any more.
    449 		 * other pointers need a great care too.
    450 		 * (IPsec routines should not mangle mbufs prior to AH/ESP)
    451 		 */
    452 		exthdrs.ip6e_dest2 = NULL;
    453 
    454 	    {
    455 		struct ip6_rthdr *rh = NULL;
    456 		int segleft_org = 0;
    457 		struct ipsec_output_state state;
    458 
    459 		if (exthdrs.ip6e_rthdr) {
    460 			rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
    461 			segleft_org = rh->ip6r_segleft;
    462 			rh->ip6r_segleft = 0;
    463 		}
    464 
    465 		memset(&state, 0, sizeof(state));
    466 		state.m = m;
    467 		error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
    468 		    &needipsectun);
    469 		m = state.m;
    470 		if (error) {
    471 			rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
    472 			/* mbuf is already reclaimed in ipsec6_output_trans. */
    473 			m = NULL;
    474 			switch (error) {
    475 			case EHOSTUNREACH:
    476 			case ENETUNREACH:
    477 			case EMSGSIZE:
    478 			case ENOBUFS:
    479 			case ENOMEM:
    480 				break;
    481 			default:
    482 				printf("ip6_output (ipsec): error code %d\n", error);
    483 				/* FALLTHROUGH */
    484 			case ENOENT:
    485 				/* don't show these error codes to the user */
    486 				error = 0;
    487 				break;
    488 			}
    489 			goto bad;
    490 		}
    491 		if (exthdrs.ip6e_rthdr) {
    492 			/* ah6_output doesn't modify mbuf chain */
    493 			rh->ip6r_segleft = segleft_org;
    494 		}
    495 	    }
    496 skip_ipsec2:;
    497 #endif
    498 	}
    499 
    500 	/*
    501 	 * If there is a routing header, replace destination address field
    502 	 * with the first hop of the routing header.
    503 	 */
    504 	if (exthdrs.ip6e_rthdr) {
    505 		struct ip6_rthdr *rh;
    506 		struct ip6_rthdr0 *rh0;
    507 		struct in6_addr *addr;
    508 		struct sockaddr_in6 sa;
    509 
    510 		rh = (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
    511 		    struct ip6_rthdr *));
    512 		finaldst = ip6->ip6_dst;
    513 		switch (rh->ip6r_type) {
    514 		case IPV6_RTHDR_TYPE_0:
    515 			 rh0 = (struct ip6_rthdr0 *)rh;
    516 			 addr = (struct in6_addr *)(rh0 + 1);
    517 
    518 			 /*
    519 			  * construct a sockaddr_in6 form of
    520 			  * the first hop.
    521 			  *
    522 			  * XXX: we may not have enough
    523 			  * information about its scope zone;
    524 			  * there is no standard API to pass
    525 			  * the information from the
    526 			  * application.
    527 			  */
    528 			 sockaddr_in6_init(&sa, addr, 0, 0, 0);
    529 			 if ((error = sa6_embedscope(&sa,
    530 			     ip6_use_defzone)) != 0) {
    531 				 goto bad;
    532 			 }
    533 			 ip6->ip6_dst = sa.sin6_addr;
    534 			 (void)memmove(&addr[0], &addr[1],
    535 			     sizeof(struct in6_addr) *
    536 			     (rh0->ip6r0_segleft - 1));
    537 			 addr[rh0->ip6r0_segleft - 1] = finaldst;
    538 			 /* XXX */
    539 			 in6_clearscope(addr + rh0->ip6r0_segleft - 1);
    540 			 break;
    541 		default:	/* is it possible? */
    542 			 error = EINVAL;
    543 			 goto bad;
    544 		}
    545 	}
    546 
    547 	/* Source address validation */
    548 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
    549 	    (flags & IPV6_UNSPECSRC) == 0) {
    550 		error = EOPNOTSUPP;
    551 		IP6_STATINC(IP6_STAT_BADSCOPE);
    552 		goto bad;
    553 	}
    554 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
    555 		error = EOPNOTSUPP;
    556 		IP6_STATINC(IP6_STAT_BADSCOPE);
    557 		goto bad;
    558 	}
    559 
    560 	IP6_STATINC(IP6_STAT_LOCALOUT);
    561 
    562 	/*
    563 	 * Route packet.
    564 	 */
    565 	/* initialize cached route */
    566 	if (ro == NULL) {
    567 		ro = &ip6route;
    568 	}
    569 	ro_pmtu = ro;
    570 	if (opt && opt->ip6po_rthdr)
    571 		ro = &opt->ip6po_route;
    572 
    573  	/*
    574 	 * if specified, try to fill in the traffic class field.
    575 	 * do not override if a non-zero value is already set.
    576 	 * we check the diffserv field and the ecn field separately.
    577 	 */
    578 	if (opt && opt->ip6po_tclass >= 0) {
    579 		int mask = 0;
    580 
    581 		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
    582 			mask |= 0xfc;
    583 		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
    584 			mask |= 0x03;
    585 		if (mask != 0)
    586 			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
    587 	}
    588 
    589 	/* fill in or override the hop limit field, if necessary. */
    590 	if (opt && opt->ip6po_hlim != -1)
    591 		ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
    592 	else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    593 		if (im6o != NULL)
    594 			ip6->ip6_hlim = im6o->im6o_multicast_hlim;
    595 		else
    596 			ip6->ip6_hlim = ip6_defmcasthlim;
    597 	}
    598 
    599 #ifdef KAME_IPSEC
    600 	if (needipsec && needipsectun) {
    601 		struct ipsec_output_state state;
    602 
    603 		/*
    604 		 * All the extension headers will become inaccessible
    605 		 * (since they can be encrypted).
    606 		 * Don't panic, we need no more updates to extension headers
    607 		 * on inner IPv6 packet (since they are now encapsulated).
    608 		 *
    609 		 * IPv6 [ESP|AH] IPv6 [extension headers] payload
    610 		 */
    611 		memset(&exthdrs, 0, sizeof(exthdrs));
    612 		exthdrs.ip6e_ip6 = m;
    613 
    614 		memset(&state, 0, sizeof(state));
    615 		state.m = m;
    616 		state.ro = ro;
    617 		state.dst = rtcache_getdst(ro);
    618 
    619 		error = ipsec6_output_tunnel(&state, sp, flags);
    620 
    621 		m = state.m;
    622 		ro_pmtu = ro = state.ro;
    623 		dst = satocsin6(state.dst);
    624 		if (error) {
    625 			/* mbuf is already reclaimed in ipsec6_output_tunnel. */
    626 			m0 = m = NULL;
    627 			m = NULL;
    628 			switch (error) {
    629 			case EHOSTUNREACH:
    630 			case ENETUNREACH:
    631 			case EMSGSIZE:
    632 			case ENOBUFS:
    633 			case ENOMEM:
    634 				break;
    635 			default:
    636 				printf("ip6_output (ipsec): error code %d\n", error);
    637 				/* FALLTHROUGH */
    638 			case ENOENT:
    639 				/* don't show these error codes to the user */
    640 				error = 0;
    641 				break;
    642 			}
    643 			goto bad;
    644 		}
    645 
    646 		exthdrs.ip6e_ip6 = m;
    647 	}
    648 #endif /* KAME_IPSEC */
    649 #ifdef FAST_IPSEC
    650 	if (needipsec) {
    651 		s = splsoftnet();
    652 		error = ipsec6_process_packet(m,sp->req);
    653 
    654 		/*
    655 		 * Preserve KAME behaviour: ENOENT can be returned
    656 		 * when an SA acquire is in progress.  Don't propagate
    657 		 * this to user-level; it confuses applications.
    658 		 * XXX this will go away when the SADB is redone.
    659 		 */
    660 		if (error == ENOENT)
    661 			error = 0;
    662 		splx(s);
    663 		goto done;
    664 	}
    665 #endif /* FAST_IPSEC */
    666 
    667 
    668 
    669 	/* adjust pointer */
    670 	ip6 = mtod(m, struct ip6_hdr *);
    671 
    672 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    673 	if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
    674 	    &ifp, &rt, 0)) != 0) {
    675 		if (ifp != NULL)
    676 			in6_ifstat_inc(ifp, ifs6_out_discard);
    677 		goto bad;
    678 	}
    679 	if (rt == NULL) {
    680 		/*
    681 		 * If in6_selectroute() does not return a route entry,
    682 		 * dst may not have been updated.
    683 		 */
    684 		rtcache_setdst(ro, sin6tosa(&dst_sa));
    685 	}
    686 
    687 	/*
    688 	 * then rt (for unicast) and ifp must be non-NULL valid values.
    689 	 */
    690 	if ((flags & IPV6_FORWARDING) == 0) {
    691 		/* XXX: the FORWARDING flag can be set for mrouting. */
    692 		in6_ifstat_inc(ifp, ifs6_out_request);
    693 	}
    694 	if (rt != NULL) {
    695 		ia = (struct in6_ifaddr *)(rt->rt_ifa);
    696 		rt->rt_use++;
    697 	}
    698 
    699 	/*
    700 	 * The outgoing interface must be in the zone of source and
    701 	 * destination addresses.  We should use ia_ifp to support the
    702 	 * case of sending packets to an address of our own.
    703 	 */
    704 	if (ia != NULL && ia->ia_ifp)
    705 		origifp = ia->ia_ifp;
    706 	else
    707 		origifp = ifp;
    708 
    709 	src0 = ip6->ip6_src;
    710 	if (in6_setscope(&src0, origifp, &zone))
    711 		goto badscope;
    712 	sockaddr_in6_init(&src_sa, &ip6->ip6_src, 0, 0, 0);
    713 	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
    714 		goto badscope;
    715 
    716 	dst0 = ip6->ip6_dst;
    717 	if (in6_setscope(&dst0, origifp, &zone))
    718 		goto badscope;
    719 	/* re-initialize to be sure */
    720 	sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
    721 	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id)
    722 		goto badscope;
    723 
    724 	/* scope check is done. */
    725 
    726 	if (rt == NULL || IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
    727 		if (dst == NULL)
    728 			dst = satocsin6(rtcache_getdst(ro));
    729 		KASSERT(dst != NULL);
    730 	} else if (opt && rtcache_validate(&opt->ip6po_nextroute) != NULL) {
    731 		/*
    732 		 * The nexthop is explicitly specified by the
    733 		 * application.  We assume the next hop is an IPv6
    734 		 * address.
    735 		 */
    736 		dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
    737 	} else if ((rt->rt_flags & RTF_GATEWAY))
    738 		dst = (struct sockaddr_in6 *)rt->rt_gateway;
    739 	else if (dst == NULL)
    740 		dst = satocsin6(rtcache_getdst(ro));
    741 
    742 	/*
    743 	 * XXXXXX: original code follows:
    744 	 */
    745 	if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
    746 		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */
    747 	else {
    748 		struct	in6_multi *in6m;
    749 
    750 		m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
    751 
    752 		in6_ifstat_inc(ifp, ifs6_out_mcast);
    753 
    754 		/*
    755 		 * Confirm that the outgoing interface supports multicast.
    756 		 */
    757 		if (!(ifp->if_flags & IFF_MULTICAST)) {
    758 			IP6_STATINC(IP6_STAT_NOROUTE);
    759 			in6_ifstat_inc(ifp, ifs6_out_discard);
    760 			error = ENETUNREACH;
    761 			goto bad;
    762 		}
    763 
    764 		IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
    765 		if (in6m != NULL &&
    766 		   (im6o == NULL || im6o->im6o_multicast_loop)) {
    767 			/*
    768 			 * If we belong to the destination multicast group
    769 			 * on the outgoing interface, and the caller did not
    770 			 * forbid loopback, loop back a copy.
    771 			 */
    772 			KASSERT(dst != NULL);
    773 			ip6_mloopback(ifp, m, dst);
    774 		} else {
    775 			/*
    776 			 * If we are acting as a multicast router, perform
    777 			 * multicast forwarding as if the packet had just
    778 			 * arrived on the interface to which we are about
    779 			 * to send.  The multicast forwarding function
    780 			 * recursively calls this function, using the
    781 			 * IPV6_FORWARDING flag to prevent infinite recursion.
    782 			 *
    783 			 * Multicasts that are looped back by ip6_mloopback(),
    784 			 * above, will be forwarded by the ip6_input() routine,
    785 			 * if necessary.
    786 			 */
    787 			if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
    788 				if (ip6_mforward(ip6, ifp, m) != 0) {
    789 					m_freem(m);
    790 					goto done;
    791 				}
    792 			}
    793 		}
    794 		/*
    795 		 * Multicasts with a hoplimit of zero may be looped back,
    796 		 * above, but must not be transmitted on a network.
    797 		 * Also, multicasts addressed to the loopback interface
    798 		 * are not sent -- the above call to ip6_mloopback() will
    799 		 * loop back a copy if this host actually belongs to the
    800 		 * destination group on the loopback interface.
    801 		 */
    802 		if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
    803 		    IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
    804 			m_freem(m);
    805 			goto done;
    806 		}
    807 	}
    808 
    809 	/*
    810 	 * Fill the outgoing inteface to tell the upper layer
    811 	 * to increment per-interface statistics.
    812 	 */
    813 	if (ifpp)
    814 		*ifpp = ifp;
    815 
    816 	/* Determine path MTU. */
    817 	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
    818 	    &alwaysfrag)) != 0)
    819 		goto bad;
    820 #ifdef KAME_IPSEC
    821 	if (needipsectun)
    822 		mtu = IPV6_MMTU;
    823 #endif
    824 
    825 	/*
    826 	 * The caller of this function may specify to use the minimum MTU
    827 	 * in some cases.
    828 	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
    829 	 * setting.  The logic is a bit complicated; by default, unicast
    830 	 * packets will follow path MTU while multicast packets will be sent at
    831 	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
    832 	 * including unicast ones will be sent at the minimum MTU.  Multicast
    833 	 * packets will always be sent at the minimum MTU unless
    834 	 * IP6PO_MINMTU_DISABLE is explicitly specified.
    835 	 * See RFC 3542 for more details.
    836 	 */
    837 	if (mtu > IPV6_MMTU) {
    838 		if ((flags & IPV6_MINMTU))
    839 			mtu = IPV6_MMTU;
    840 		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
    841 			mtu = IPV6_MMTU;
    842 		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
    843 			 (opt == NULL ||
    844 			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
    845 			mtu = IPV6_MMTU;
    846 		}
    847 	}
    848 
    849 	/*
    850 	 * clear embedded scope identifiers if necessary.
    851 	 * in6_clearscope will touch the addresses only when necessary.
    852 	 */
    853 	in6_clearscope(&ip6->ip6_src);
    854 	in6_clearscope(&ip6->ip6_dst);
    855 
    856 	/*
    857 	 * If the outgoing packet contains a hop-by-hop options header,
    858 	 * it must be examined and processed even by the source node.
    859 	 * (RFC 2460, section 4.)
    860 	 */
    861 	if (exthdrs.ip6e_hbh) {
    862 		struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
    863 		u_int32_t dummy1; /* XXX unused */
    864 		u_int32_t dummy2; /* XXX unused */
    865 
    866 		/*
    867 		 *  XXX: if we have to send an ICMPv6 error to the sender,
    868 		 *       we need the M_LOOP flag since icmp6_error() expects
    869 		 *       the IPv6 and the hop-by-hop options header are
    870 		 *       continuous unless the flag is set.
    871 		 */
    872 		m->m_flags |= M_LOOP;
    873 		m->m_pkthdr.rcvif = ifp;
    874 		if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
    875 		    ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
    876 		    &dummy1, &dummy2) < 0) {
    877 			/* m was already freed at this point */
    878 			error = EINVAL;/* better error? */
    879 			goto done;
    880 		}
    881 		m->m_flags &= ~M_LOOP; /* XXX */
    882 		m->m_pkthdr.rcvif = NULL;
    883 	}
    884 
    885 #ifdef PFIL_HOOKS
    886 	/*
    887 	 * Run through list of hooks for output packets.
    888 	 */
    889 	if ((error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT)) != 0)
    890 		goto done;
    891 	if (m == NULL)
    892 		goto done;
    893 	ip6 = mtod(m, struct ip6_hdr *);
    894 #endif /* PFIL_HOOKS */
    895 	/*
    896 	 * Send the packet to the outgoing interface.
    897 	 * If necessary, do IPv6 fragmentation before sending.
    898 	 *
    899 	 * the logic here is rather complex:
    900 	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
    901 	 * 1-a:	send as is if tlen <= path mtu
    902 	 * 1-b:	fragment if tlen > path mtu
    903 	 *
    904 	 * 2: if user asks us not to fragment (dontfrag == 1)
    905 	 * 2-a:	send as is if tlen <= interface mtu
    906 	 * 2-b:	error if tlen > interface mtu
    907 	 *
    908 	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
    909 	 *	always fragment
    910 	 *
    911 	 * 4: if dontfrag == 1 && alwaysfrag == 1
    912 	 *	error, as we cannot handle this conflicting request
    913 	 */
    914 	tlen = m->m_pkthdr.len;
    915 	tso = (m->m_pkthdr.csum_flags & M_CSUM_TSOv6) != 0;
    916 	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
    917 		dontfrag = 1;
    918 	else
    919 		dontfrag = 0;
    920 
    921 	if (dontfrag && alwaysfrag) {	/* case 4 */
    922 		/* conflicting request - can't transmit */
    923 		error = EMSGSIZE;
    924 		goto bad;
    925 	}
    926 	if (dontfrag && (!tso && tlen > IN6_LINKMTU(ifp))) {	/* case 2-b */
    927 		/*
    928 		 * Even if the DONTFRAG option is specified, we cannot send the
    929 		 * packet when the data length is larger than the MTU of the
    930 		 * outgoing interface.
    931 		 * Notify the error by sending IPV6_PATHMTU ancillary data as
    932 		 * well as returning an error code (the latter is not described
    933 		 * in the API spec.)
    934 		 */
    935 		u_int32_t mtu32;
    936 		struct ip6ctlparam ip6cp;
    937 
    938 		mtu32 = (u_int32_t)mtu;
    939 		memset(&ip6cp, 0, sizeof(ip6cp));
    940 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
    941 		pfctlinput2(PRC_MSGSIZE,
    942 		    rtcache_getdst(ro_pmtu), &ip6cp);
    943 
    944 		error = EMSGSIZE;
    945 		goto bad;
    946 	}
    947 
    948 	/*
    949 	 * transmit packet without fragmentation
    950 	 */
    951 	if (dontfrag || (!alwaysfrag && (tlen <= mtu || tso))) {
    952 		/* case 1-a and 2-a */
    953 		struct in6_ifaddr *ia6;
    954 		int sw_csum;
    955 
    956 		ip6 = mtod(m, struct ip6_hdr *);
    957 		ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
    958 		if (ia6) {
    959 			/* Record statistics for this interface address. */
    960 			ia6->ia_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len;
    961 		}
    962 #ifdef KAME_IPSEC
    963 		/* clean ipsec history once it goes out of the node */
    964 		ipsec_delaux(m);
    965 #endif
    966 
    967 		sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx;
    968 		if ((sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0) {
    969 			if (IN6_NEED_CHECKSUM(ifp,
    970 			    sw_csum & (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
    971 				in6_delayed_cksum(m);
    972 			}
    973 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
    974 		}
    975 
    976 		KASSERT(dst != NULL);
    977 		if (__predict_true(!tso ||
    978 		    (ifp->if_capenable & IFCAP_TSOv6) != 0)) {
    979 			error = nd6_output(ifp, origifp, m, dst, rt);
    980 		} else {
    981 			error = ip6_tso_output(ifp, origifp, m, dst, rt);
    982 		}
    983 		goto done;
    984 	}
    985 
    986 	if (tso) {
    987 		error = EINVAL; /* XXX */
    988 		goto bad;
    989 	}
    990 
    991 	/*
    992 	 * try to fragment the packet.  case 1-b and 3
    993 	 */
    994 	if (mtu < IPV6_MMTU) {
    995 		/* path MTU cannot be less than IPV6_MMTU */
    996 		error = EMSGSIZE;
    997 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
    998 		goto bad;
    999 	} else if (ip6->ip6_plen == 0) {
   1000 		/* jumbo payload cannot be fragmented */
   1001 		error = EMSGSIZE;
   1002 		in6_ifstat_inc(ifp, ifs6_out_fragfail);
   1003 		goto bad;
   1004 	} else {
   1005 		struct mbuf **mnext, *m_frgpart;
   1006 		struct ip6_frag *ip6f;
   1007 		u_int32_t id = htonl(ip6_randomid());
   1008 		u_char nextproto;
   1009 #if 0				/* see below */
   1010 		struct ip6ctlparam ip6cp;
   1011 		u_int32_t mtu32;
   1012 #endif
   1013 
   1014 		/*
   1015 		 * Too large for the destination or interface;
   1016 		 * fragment if possible.
   1017 		 * Must be able to put at least 8 bytes per fragment.
   1018 		 */
   1019 		hlen = unfragpartlen;
   1020 		if (mtu > IPV6_MAXPACKET)
   1021 			mtu = IPV6_MAXPACKET;
   1022 
   1023 #if 0
   1024 		/*
   1025 		 * It is believed this code is a leftover from the
   1026 		 * development of the IPV6_RECVPATHMTU sockopt and
   1027 		 * associated work to implement RFC3542.
   1028 		 * It's not entirely clear what the intent of the API
   1029 		 * is at this point, so disable this code for now.
   1030 		 * The IPV6_RECVPATHMTU sockopt and/or IPV6_DONTFRAG
   1031 		 * will send notifications if the application requests.
   1032 		 */
   1033 
   1034 		/* Notify a proper path MTU to applications. */
   1035 		mtu32 = (u_int32_t)mtu;
   1036 		memset(&ip6cp, 0, sizeof(ip6cp));
   1037 		ip6cp.ip6c_cmdarg = (void *)&mtu32;
   1038 		pfctlinput2(PRC_MSGSIZE,
   1039 		    rtcache_getdst(ro_pmtu), &ip6cp);
   1040 #endif
   1041 
   1042 		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
   1043 		if (len < 8) {
   1044 			error = EMSGSIZE;
   1045 			in6_ifstat_inc(ifp, ifs6_out_fragfail);
   1046 			goto bad;
   1047 		}
   1048 
   1049 		mnext = &m->m_nextpkt;
   1050 
   1051 		/*
   1052 		 * Change the next header field of the last header in the
   1053 		 * unfragmentable part.
   1054 		 */
   1055 		if (exthdrs.ip6e_rthdr) {
   1056 			nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
   1057 			*mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
   1058 		} else if (exthdrs.ip6e_dest1) {
   1059 			nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
   1060 			*mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
   1061 		} else if (exthdrs.ip6e_hbh) {
   1062 			nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
   1063 			*mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
   1064 		} else {
   1065 			nextproto = ip6->ip6_nxt;
   1066 			ip6->ip6_nxt = IPPROTO_FRAGMENT;
   1067 		}
   1068 
   1069 		if ((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6))
   1070 		    != 0) {
   1071 			if (IN6_NEED_CHECKSUM(ifp,
   1072 			    m->m_pkthdr.csum_flags &
   1073 			    (M_CSUM_UDPv6|M_CSUM_TCPv6))) {
   1074 				in6_delayed_cksum(m);
   1075 			}
   1076 			m->m_pkthdr.csum_flags &= ~(M_CSUM_UDPv6|M_CSUM_TCPv6);
   1077 		}
   1078 
   1079 		/*
   1080 		 * Loop through length of segment after first fragment,
   1081 		 * make new header and copy data of each part and link onto
   1082 		 * chain.
   1083 		 */
   1084 		m0 = m;
   1085 		for (off = hlen; off < tlen; off += len) {
   1086 			struct mbuf *mlast;
   1087 
   1088 			MGETHDR(m, M_DONTWAIT, MT_HEADER);
   1089 			if (!m) {
   1090 				error = ENOBUFS;
   1091 				IP6_STATINC(IP6_STAT_ODROPPED);
   1092 				goto sendorfree;
   1093 			}
   1094 			m->m_pkthdr.rcvif = NULL;
   1095 			m->m_flags = m0->m_flags & M_COPYFLAGS;
   1096 			*mnext = m;
   1097 			mnext = &m->m_nextpkt;
   1098 			m->m_data += max_linkhdr;
   1099 			mhip6 = mtod(m, struct ip6_hdr *);
   1100 			*mhip6 = *ip6;
   1101 			m->m_len = sizeof(*mhip6);
   1102 			error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
   1103 			if (error) {
   1104 				IP6_STATINC(IP6_STAT_ODROPPED);
   1105 				goto sendorfree;
   1106 			}
   1107 			ip6f->ip6f_offlg = htons((u_int16_t)((off - hlen) & ~7));
   1108 			if (off + len >= tlen)
   1109 				len = tlen - off;
   1110 			else
   1111 				ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
   1112 			mhip6->ip6_plen = htons((u_int16_t)(len + hlen +
   1113 			    sizeof(*ip6f) - sizeof(struct ip6_hdr)));
   1114 			if ((m_frgpart = m_copy(m0, off, len)) == 0) {
   1115 				error = ENOBUFS;
   1116 				IP6_STATINC(IP6_STAT_ODROPPED);
   1117 				goto sendorfree;
   1118 			}
   1119 			for (mlast = m; mlast->m_next; mlast = mlast->m_next)
   1120 				;
   1121 			mlast->m_next = m_frgpart;
   1122 			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
   1123 			m->m_pkthdr.rcvif = (struct ifnet *)0;
   1124 			ip6f->ip6f_reserved = 0;
   1125 			ip6f->ip6f_ident = id;
   1126 			ip6f->ip6f_nxt = nextproto;
   1127 			IP6_STATINC(IP6_STAT_OFRAGMENTS);
   1128 			in6_ifstat_inc(ifp, ifs6_out_fragcreat);
   1129 		}
   1130 
   1131 		in6_ifstat_inc(ifp, ifs6_out_fragok);
   1132 	}
   1133 
   1134 	/*
   1135 	 * Remove leading garbages.
   1136 	 */
   1137 sendorfree:
   1138 	m = m0->m_nextpkt;
   1139 	m0->m_nextpkt = 0;
   1140 	m_freem(m0);
   1141 	for (m0 = m; m; m = m0) {
   1142 		m0 = m->m_nextpkt;
   1143 		m->m_nextpkt = 0;
   1144 		if (error == 0) {
   1145 			struct in6_ifaddr *ia6;
   1146 			ip6 = mtod(m, struct ip6_hdr *);
   1147 			ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
   1148 			if (ia6) {
   1149 				/*
   1150 				 * Record statistics for this interface
   1151 				 * address.
   1152 				 */
   1153 				ia6->ia_ifa.ifa_data.ifad_outbytes +=
   1154 				    m->m_pkthdr.len;
   1155 			}
   1156 #ifdef KAME_IPSEC
   1157 			/* clean ipsec history once it goes out of the node */
   1158 			ipsec_delaux(m);
   1159 #endif
   1160 			KASSERT(dst != NULL);
   1161 			error = nd6_output(ifp, origifp, m, dst, rt);
   1162 		} else
   1163 			m_freem(m);
   1164 	}
   1165 
   1166 	if (error == 0)
   1167 		IP6_STATINC(IP6_STAT_FRAGMENTED);
   1168 
   1169 done:
   1170 	rtcache_free(&ip6route);
   1171 
   1172 #ifdef KAME_IPSEC
   1173 	if (sp != NULL)
   1174 		key_freesp(sp);
   1175 #endif /* KAME_IPSEC */
   1176 #ifdef FAST_IPSEC
   1177 	if (sp != NULL)
   1178 		KEY_FREESP(&sp);
   1179 #endif /* FAST_IPSEC */
   1180 
   1181 
   1182 	return (error);
   1183 
   1184 freehdrs:
   1185 	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
   1186 	m_freem(exthdrs.ip6e_dest1);
   1187 	m_freem(exthdrs.ip6e_rthdr);
   1188 	m_freem(exthdrs.ip6e_dest2);
   1189 	/* FALLTHROUGH */
   1190 bad:
   1191 	m_freem(m);
   1192 	goto done;
   1193 badscope:
   1194 	IP6_STATINC(IP6_STAT_BADSCOPE);
   1195 	in6_ifstat_inc(origifp, ifs6_out_discard);
   1196 	if (error == 0)
   1197 		error = EHOSTUNREACH; /* XXX */
   1198 	goto bad;
   1199 }
   1200 
   1201 static int
   1202 ip6_copyexthdr(struct mbuf **mp, void *hdr, int hlen)
   1203 {
   1204 	struct mbuf *m;
   1205 
   1206 	if (hlen > MCLBYTES)
   1207 		return (ENOBUFS); /* XXX */
   1208 
   1209 	MGET(m, M_DONTWAIT, MT_DATA);
   1210 	if (!m)
   1211 		return (ENOBUFS);
   1212 
   1213 	if (hlen > MLEN) {
   1214 		MCLGET(m, M_DONTWAIT);
   1215 		if ((m->m_flags & M_EXT) == 0) {
   1216 			m_free(m);
   1217 			return (ENOBUFS);
   1218 		}
   1219 	}
   1220 	m->m_len = hlen;
   1221 	if (hdr)
   1222 		bcopy(hdr, mtod(m, void *), hlen);
   1223 
   1224 	*mp = m;
   1225 	return (0);
   1226 }
   1227 
   1228 /*
   1229  * Process a delayed payload checksum calculation.
   1230  */
   1231 void
   1232 in6_delayed_cksum(struct mbuf *m)
   1233 {
   1234 	uint16_t csum, offset;
   1235 
   1236 	KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1237 	KASSERT((~m->m_pkthdr.csum_flags & (M_CSUM_UDPv6|M_CSUM_TCPv6)) != 0);
   1238 	KASSERT((m->m_pkthdr.csum_flags
   1239 	    & (M_CSUM_UDPv4|M_CSUM_TCPv4|M_CSUM_TSOv4)) == 0);
   1240 
   1241 	offset = M_CSUM_DATA_IPv6_HL(m->m_pkthdr.csum_data);
   1242 	csum = in6_cksum(m, 0, offset, m->m_pkthdr.len - offset);
   1243 	if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv6) != 0) {
   1244 		csum = 0xffff;
   1245 	}
   1246 
   1247 	offset += M_CSUM_DATA_IPv6_OFFSET(m->m_pkthdr.csum_data);
   1248 	if ((offset + sizeof(csum)) > m->m_len) {
   1249 		m_copyback(m, offset, sizeof(csum), &csum);
   1250 	} else {
   1251 		*(uint16_t *)(mtod(m, char *) + offset) = csum;
   1252 	}
   1253 }
   1254 
   1255 /*
   1256  * Insert jumbo payload option.
   1257  */
   1258 static int
   1259 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
   1260 {
   1261 	struct mbuf *mopt;
   1262 	u_int8_t *optbuf;
   1263 	u_int32_t v;
   1264 
   1265 #define JUMBOOPTLEN	8	/* length of jumbo payload option and padding */
   1266 
   1267 	/*
   1268 	 * If there is no hop-by-hop options header, allocate new one.
   1269 	 * If there is one but it doesn't have enough space to store the
   1270 	 * jumbo payload option, allocate a cluster to store the whole options.
   1271 	 * Otherwise, use it to store the options.
   1272 	 */
   1273 	if (exthdrs->ip6e_hbh == 0) {
   1274 		MGET(mopt, M_DONTWAIT, MT_DATA);
   1275 		if (mopt == 0)
   1276 			return (ENOBUFS);
   1277 		mopt->m_len = JUMBOOPTLEN;
   1278 		optbuf = mtod(mopt, u_int8_t *);
   1279 		optbuf[1] = 0;	/* = ((JUMBOOPTLEN) >> 3) - 1 */
   1280 		exthdrs->ip6e_hbh = mopt;
   1281 	} else {
   1282 		struct ip6_hbh *hbh;
   1283 
   1284 		mopt = exthdrs->ip6e_hbh;
   1285 		if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
   1286 			/*
   1287 			 * XXX assumption:
   1288 			 * - exthdrs->ip6e_hbh is not referenced from places
   1289 			 *   other than exthdrs.
   1290 			 * - exthdrs->ip6e_hbh is not an mbuf chain.
   1291 			 */
   1292 			int oldoptlen = mopt->m_len;
   1293 			struct mbuf *n;
   1294 
   1295 			/*
   1296 			 * XXX: give up if the whole (new) hbh header does
   1297 			 * not fit even in an mbuf cluster.
   1298 			 */
   1299 			if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
   1300 				return (ENOBUFS);
   1301 
   1302 			/*
   1303 			 * As a consequence, we must always prepare a cluster
   1304 			 * at this point.
   1305 			 */
   1306 			MGET(n, M_DONTWAIT, MT_DATA);
   1307 			if (n) {
   1308 				MCLGET(n, M_DONTWAIT);
   1309 				if ((n->m_flags & M_EXT) == 0) {
   1310 					m_freem(n);
   1311 					n = NULL;
   1312 				}
   1313 			}
   1314 			if (!n)
   1315 				return (ENOBUFS);
   1316 			n->m_len = oldoptlen + JUMBOOPTLEN;
   1317 			bcopy(mtod(mopt, void *), mtod(n, void *),
   1318 			    oldoptlen);
   1319 			optbuf = mtod(n, u_int8_t *) + oldoptlen;
   1320 			m_freem(mopt);
   1321 			mopt = exthdrs->ip6e_hbh = n;
   1322 		} else {
   1323 			optbuf = mtod(mopt, u_int8_t *) + mopt->m_len;
   1324 			mopt->m_len += JUMBOOPTLEN;
   1325 		}
   1326 		optbuf[0] = IP6OPT_PADN;
   1327 		optbuf[1] = 0;
   1328 
   1329 		/*
   1330 		 * Adjust the header length according to the pad and
   1331 		 * the jumbo payload option.
   1332 		 */
   1333 		hbh = mtod(mopt, struct ip6_hbh *);
   1334 		hbh->ip6h_len += (JUMBOOPTLEN >> 3);
   1335 	}
   1336 
   1337 	/* fill in the option. */
   1338 	optbuf[2] = IP6OPT_JUMBO;
   1339 	optbuf[3] = 4;
   1340 	v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
   1341 	bcopy(&v, &optbuf[4], sizeof(u_int32_t));
   1342 
   1343 	/* finally, adjust the packet header length */
   1344 	exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
   1345 
   1346 	return (0);
   1347 #undef JUMBOOPTLEN
   1348 }
   1349 
   1350 /*
   1351  * Insert fragment header and copy unfragmentable header portions.
   1352  */
   1353 static int
   1354 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
   1355 	struct ip6_frag **frghdrp)
   1356 {
   1357 	struct mbuf *n, *mlast;
   1358 
   1359 	if (hlen > sizeof(struct ip6_hdr)) {
   1360 		n = m_copym(m0, sizeof(struct ip6_hdr),
   1361 		    hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
   1362 		if (n == 0)
   1363 			return (ENOBUFS);
   1364 		m->m_next = n;
   1365 	} else
   1366 		n = m;
   1367 
   1368 	/* Search for the last mbuf of unfragmentable part. */
   1369 	for (mlast = n; mlast->m_next; mlast = mlast->m_next)
   1370 		;
   1371 
   1372 	if ((mlast->m_flags & M_EXT) == 0 &&
   1373 	    M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
   1374 		/* use the trailing space of the last mbuf for the fragment hdr */
   1375 		*frghdrp = (struct ip6_frag *)(mtod(mlast, char *) +
   1376 		    mlast->m_len);
   1377 		mlast->m_len += sizeof(struct ip6_frag);
   1378 		m->m_pkthdr.len += sizeof(struct ip6_frag);
   1379 	} else {
   1380 		/* allocate a new mbuf for the fragment header */
   1381 		struct mbuf *mfrg;
   1382 
   1383 		MGET(mfrg, M_DONTWAIT, MT_DATA);
   1384 		if (mfrg == 0)
   1385 			return (ENOBUFS);
   1386 		mfrg->m_len = sizeof(struct ip6_frag);
   1387 		*frghdrp = mtod(mfrg, struct ip6_frag *);
   1388 		mlast->m_next = mfrg;
   1389 	}
   1390 
   1391 	return (0);
   1392 }
   1393 
   1394 static int
   1395 ip6_getpmtu(struct route *ro_pmtu, struct route *ro, struct ifnet *ifp,
   1396     const struct in6_addr *dst, u_long *mtup, int *alwaysfragp)
   1397 {
   1398 	struct rtentry *rt;
   1399 	u_int32_t mtu = 0;
   1400 	int alwaysfrag = 0;
   1401 	int error = 0;
   1402 
   1403 	if (ro_pmtu != ro) {
   1404 		union {
   1405 			struct sockaddr		dst;
   1406 			struct sockaddr_in6	dst6;
   1407 		} u;
   1408 
   1409 		/* The first hop and the final destination may differ. */
   1410 		sockaddr_in6_init(&u.dst6, dst, 0, 0, 0);
   1411 		rt = rtcache_lookup(ro_pmtu, &u.dst);
   1412 	} else
   1413 		rt = rtcache_validate(ro_pmtu);
   1414 	if (rt != NULL) {
   1415 		u_int32_t ifmtu;
   1416 
   1417 		if (ifp == NULL)
   1418 			ifp = rt->rt_ifp;
   1419 		ifmtu = IN6_LINKMTU(ifp);
   1420 		mtu = rt->rt_rmx.rmx_mtu;
   1421 		if (mtu == 0)
   1422 			mtu = ifmtu;
   1423 		else if (mtu < IPV6_MMTU) {
   1424 			/*
   1425 			 * RFC2460 section 5, last paragraph:
   1426 			 * if we record ICMPv6 too big message with
   1427 			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
   1428 			 * or smaller, with fragment header attached.
   1429 			 * (fragment header is needed regardless from the
   1430 			 * packet size, for translators to identify packets)
   1431 			 */
   1432 			alwaysfrag = 1;
   1433 			mtu = IPV6_MMTU;
   1434 		} else if (mtu > ifmtu) {
   1435 			/*
   1436 			 * The MTU on the route is larger than the MTU on
   1437 			 * the interface!  This shouldn't happen, unless the
   1438 			 * MTU of the interface has been changed after the
   1439 			 * interface was brought up.  Change the MTU in the
   1440 			 * route to match the interface MTU (as long as the
   1441 			 * field isn't locked).
   1442 			 */
   1443 			mtu = ifmtu;
   1444 			if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
   1445 				rt->rt_rmx.rmx_mtu = mtu;
   1446 		}
   1447 	} else if (ifp) {
   1448 		mtu = IN6_LINKMTU(ifp);
   1449 	} else
   1450 		error = EHOSTUNREACH; /* XXX */
   1451 
   1452 	*mtup = mtu;
   1453 	if (alwaysfragp)
   1454 		*alwaysfragp = alwaysfrag;
   1455 	return (error);
   1456 }
   1457 
   1458 /*
   1459  * IP6 socket option processing.
   1460  */
   1461 int
   1462 ip6_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   1463 {
   1464 	int optdatalen, uproto;
   1465 	void *optdata;
   1466 	struct in6pcb *in6p = sotoin6pcb(so);
   1467 	int error, optval;
   1468 	int level, optname;
   1469 
   1470 	KASSERT(sopt != NULL);
   1471 
   1472 	level = sopt->sopt_level;
   1473 	optname = sopt->sopt_name;
   1474 
   1475 	error = optval = 0;
   1476 	uproto = (int)so->so_proto->pr_protocol;
   1477 
   1478 	if (level != IPPROTO_IPV6) {
   1479 		return ENOPROTOOPT;
   1480 	}
   1481 	switch (op) {
   1482 	case PRCO_SETOPT:
   1483 		switch (optname) {
   1484 #ifdef RFC2292
   1485 		case IPV6_2292PKTOPTIONS:
   1486 			error = ip6_pcbopts(&in6p->in6p_outputopts, so, sopt);
   1487 			break;
   1488 #endif
   1489 
   1490 		/*
   1491 		 * Use of some Hop-by-Hop options or some
   1492 		 * Destination options, might require special
   1493 		 * privilege.  That is, normal applications
   1494 		 * (without special privilege) might be forbidden
   1495 		 * from setting certain options in outgoing packets,
   1496 		 * and might never see certain options in received
   1497 		 * packets. [RFC 2292 Section 6]
   1498 		 * KAME specific note:
   1499 		 *  KAME prevents non-privileged users from sending or
   1500 		 *  receiving ANY hbh/dst options in order to avoid
   1501 		 *  overhead of parsing options in the kernel.
   1502 		 */
   1503 		case IPV6_RECVHOPOPTS:
   1504 		case IPV6_RECVDSTOPTS:
   1505 		case IPV6_RECVRTHDRDSTOPTS:
   1506 			error = kauth_authorize_generic(kauth_cred_get(),
   1507 			    KAUTH_GENERIC_ISSUSER, NULL);
   1508 			if (error)
   1509 				break;
   1510 			/* FALLTHROUGH */
   1511 		case IPV6_UNICAST_HOPS:
   1512 		case IPV6_HOPLIMIT:
   1513 		case IPV6_FAITH:
   1514 
   1515 		case IPV6_RECVPKTINFO:
   1516 		case IPV6_RECVHOPLIMIT:
   1517 		case IPV6_RECVRTHDR:
   1518 		case IPV6_RECVPATHMTU:
   1519 		case IPV6_RECVTCLASS:
   1520 		case IPV6_V6ONLY:
   1521 			error = sockopt_getint(sopt, &optval);
   1522 			if (error)
   1523 				break;
   1524 			switch (optname) {
   1525 			case IPV6_UNICAST_HOPS:
   1526 				if (optval < -1 || optval >= 256)
   1527 					error = EINVAL;
   1528 				else {
   1529 					/* -1 = kernel default */
   1530 					in6p->in6p_hops = optval;
   1531 				}
   1532 				break;
   1533 #define OPTSET(bit) \
   1534 do { \
   1535 if (optval) \
   1536 	in6p->in6p_flags |= (bit); \
   1537 else \
   1538 	in6p->in6p_flags &= ~(bit); \
   1539 } while (/*CONSTCOND*/ 0)
   1540 
   1541 #ifdef RFC2292
   1542 #define OPTSET2292(bit) 			\
   1543 do { 						\
   1544 in6p->in6p_flags |= IN6P_RFC2292; 	\
   1545 if (optval) 				\
   1546 	in6p->in6p_flags |= (bit); 	\
   1547 else 					\
   1548 	in6p->in6p_flags &= ~(bit); 	\
   1549 } while (/*CONSTCOND*/ 0)
   1550 #endif
   1551 
   1552 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
   1553 
   1554 			case IPV6_RECVPKTINFO:
   1555 #ifdef RFC2292
   1556 				/* cannot mix with RFC2292 */
   1557 				if (OPTBIT(IN6P_RFC2292)) {
   1558 					error = EINVAL;
   1559 					break;
   1560 				}
   1561 #endif
   1562 				OPTSET(IN6P_PKTINFO);
   1563 				break;
   1564 
   1565 			case IPV6_HOPLIMIT:
   1566 			{
   1567 				struct ip6_pktopts **optp;
   1568 
   1569 #ifdef RFC2292
   1570 				/* cannot mix with RFC2292 */
   1571 				if (OPTBIT(IN6P_RFC2292)) {
   1572 					error = EINVAL;
   1573 					break;
   1574 				}
   1575 #endif
   1576 				optp = &in6p->in6p_outputopts;
   1577 				error = ip6_pcbopt(IPV6_HOPLIMIT,
   1578 						   (u_char *)&optval,
   1579 						   sizeof(optval),
   1580 						   optp,
   1581 						   kauth_cred_get(), uproto);
   1582 				break;
   1583 			}
   1584 
   1585 			case IPV6_RECVHOPLIMIT:
   1586 #ifdef RFC2292
   1587 				/* cannot mix with RFC2292 */
   1588 				if (OPTBIT(IN6P_RFC2292)) {
   1589 					error = EINVAL;
   1590 					break;
   1591 				}
   1592 #endif
   1593 				OPTSET(IN6P_HOPLIMIT);
   1594 				break;
   1595 
   1596 			case IPV6_RECVHOPOPTS:
   1597 #ifdef RFC2292
   1598 				/* cannot mix with RFC2292 */
   1599 				if (OPTBIT(IN6P_RFC2292)) {
   1600 					error = EINVAL;
   1601 					break;
   1602 				}
   1603 #endif
   1604 				OPTSET(IN6P_HOPOPTS);
   1605 				break;
   1606 
   1607 			case IPV6_RECVDSTOPTS:
   1608 #ifdef RFC2292
   1609 				/* cannot mix with RFC2292 */
   1610 				if (OPTBIT(IN6P_RFC2292)) {
   1611 					error = EINVAL;
   1612 					break;
   1613 				}
   1614 #endif
   1615 				OPTSET(IN6P_DSTOPTS);
   1616 				break;
   1617 
   1618 			case IPV6_RECVRTHDRDSTOPTS:
   1619 #ifdef RFC2292
   1620 				/* cannot mix with RFC2292 */
   1621 				if (OPTBIT(IN6P_RFC2292)) {
   1622 					error = EINVAL;
   1623 					break;
   1624 				}
   1625 #endif
   1626 				OPTSET(IN6P_RTHDRDSTOPTS);
   1627 				break;
   1628 
   1629 			case IPV6_RECVRTHDR:
   1630 #ifdef RFC2292
   1631 				/* cannot mix with RFC2292 */
   1632 				if (OPTBIT(IN6P_RFC2292)) {
   1633 					error = EINVAL;
   1634 					break;
   1635 				}
   1636 #endif
   1637 				OPTSET(IN6P_RTHDR);
   1638 				break;
   1639 
   1640 			case IPV6_FAITH:
   1641 				OPTSET(IN6P_FAITH);
   1642 				break;
   1643 
   1644 			case IPV6_RECVPATHMTU:
   1645 				/*
   1646 				 * We ignore this option for TCP
   1647 				 * sockets.
   1648 				 * (RFC3542 leaves this case
   1649 				 * unspecified.)
   1650 				 */
   1651 				if (uproto != IPPROTO_TCP)
   1652 					OPTSET(IN6P_MTU);
   1653 				break;
   1654 
   1655 			case IPV6_V6ONLY:
   1656 				/*
   1657 				 * make setsockopt(IPV6_V6ONLY)
   1658 				 * available only prior to bind(2).
   1659 				 * see ipng mailing list, Jun 22 2001.
   1660 				 */
   1661 				if (in6p->in6p_lport ||
   1662 				    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
   1663 					error = EINVAL;
   1664 					break;
   1665 				}
   1666 #ifdef INET6_BINDV6ONLY
   1667 				if (!optval)
   1668 					error = EINVAL;
   1669 #else
   1670 				OPTSET(IN6P_IPV6_V6ONLY);
   1671 #endif
   1672 				break;
   1673 			case IPV6_RECVTCLASS:
   1674 #ifdef RFC2292
   1675 				/* cannot mix with RFC2292 XXX */
   1676 				if (OPTBIT(IN6P_RFC2292)) {
   1677 					error = EINVAL;
   1678 					break;
   1679 				}
   1680 #endif
   1681 				OPTSET(IN6P_TCLASS);
   1682 				break;
   1683 
   1684 			}
   1685 			break;
   1686 
   1687 		case IPV6_OTCLASS:
   1688 		{
   1689 			struct ip6_pktopts **optp;
   1690 			u_int8_t tclass;
   1691 
   1692 			error = sockopt_get(sopt, &tclass, sizeof(tclass));
   1693 			if (error)
   1694 				break;
   1695 			optp = &in6p->in6p_outputopts;
   1696 			error = ip6_pcbopt(optname,
   1697 					   (u_char *)&tclass,
   1698 					   sizeof(tclass),
   1699 					   optp,
   1700 					   kauth_cred_get(), uproto);
   1701 			break;
   1702 		}
   1703 
   1704 		case IPV6_TCLASS:
   1705 		case IPV6_DONTFRAG:
   1706 		case IPV6_USE_MIN_MTU:
   1707 			error = sockopt_getint(sopt, &optval);
   1708 			if (error)
   1709 				break;
   1710 			{
   1711 				struct ip6_pktopts **optp;
   1712 				optp = &in6p->in6p_outputopts;
   1713 				error = ip6_pcbopt(optname,
   1714 						   (u_char *)&optval,
   1715 						   sizeof(optval),
   1716 						   optp,
   1717 						   kauth_cred_get(), uproto);
   1718 				break;
   1719 			}
   1720 
   1721 #ifdef RFC2292
   1722 		case IPV6_2292PKTINFO:
   1723 		case IPV6_2292HOPLIMIT:
   1724 		case IPV6_2292HOPOPTS:
   1725 		case IPV6_2292DSTOPTS:
   1726 		case IPV6_2292RTHDR:
   1727 			/* RFC 2292 */
   1728 			error = sockopt_getint(sopt, &optval);
   1729 			if (error)
   1730 				break;
   1731 
   1732 			switch (optname) {
   1733 			case IPV6_2292PKTINFO:
   1734 				OPTSET2292(IN6P_PKTINFO);
   1735 				break;
   1736 			case IPV6_2292HOPLIMIT:
   1737 				OPTSET2292(IN6P_HOPLIMIT);
   1738 				break;
   1739 			case IPV6_2292HOPOPTS:
   1740 				/*
   1741 				 * Check super-user privilege.
   1742 				 * See comments for IPV6_RECVHOPOPTS.
   1743 				 */
   1744 				error =
   1745 				    kauth_authorize_generic(kauth_cred_get(),
   1746 				    KAUTH_GENERIC_ISSUSER, NULL);
   1747 				if (error)
   1748 					return (error);
   1749 				OPTSET2292(IN6P_HOPOPTS);
   1750 				break;
   1751 			case IPV6_2292DSTOPTS:
   1752 				error =
   1753 				    kauth_authorize_generic(kauth_cred_get(),
   1754 				    KAUTH_GENERIC_ISSUSER, NULL);
   1755 				if (error)
   1756 					return (error);
   1757 				OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
   1758 				break;
   1759 			case IPV6_2292RTHDR:
   1760 				OPTSET2292(IN6P_RTHDR);
   1761 				break;
   1762 			}
   1763 			break;
   1764 #endif
   1765 		case IPV6_PKTINFO:
   1766 		case IPV6_HOPOPTS:
   1767 		case IPV6_RTHDR:
   1768 		case IPV6_DSTOPTS:
   1769 		case IPV6_RTHDRDSTOPTS:
   1770 		case IPV6_NEXTHOP: {
   1771 			/* new advanced API (RFC3542) */
   1772 			void *optbuf;
   1773 			int optbuflen;
   1774 			struct ip6_pktopts **optp;
   1775 
   1776 #ifdef RFC2292
   1777 			/* cannot mix with RFC2292 */
   1778 			if (OPTBIT(IN6P_RFC2292)) {
   1779 				error = EINVAL;
   1780 				break;
   1781 			}
   1782 #endif
   1783 
   1784 			optbuflen = sopt->sopt_size;
   1785 			optbuf = malloc(optbuflen, M_IP6OPT, M_NOWAIT);
   1786 			if (optbuf == NULL) {
   1787 				error = ENOBUFS;
   1788 				break;
   1789 			}
   1790 
   1791 			sockopt_get(sopt, optbuf, optbuflen);
   1792 			optp = &in6p->in6p_outputopts;
   1793 			error = ip6_pcbopt(optname, optbuf, optbuflen,
   1794 			    optp, kauth_cred_get(), uproto);
   1795 			break;
   1796 			}
   1797 #undef OPTSET
   1798 
   1799 		case IPV6_MULTICAST_IF:
   1800 		case IPV6_MULTICAST_HOPS:
   1801 		case IPV6_MULTICAST_LOOP:
   1802 		case IPV6_JOIN_GROUP:
   1803 		case IPV6_LEAVE_GROUP:
   1804 			error = ip6_setmoptions(sopt, &in6p->in6p_moptions);
   1805 			break;
   1806 
   1807 		case IPV6_PORTRANGE:
   1808 			error = sockopt_getint(sopt, &optval);
   1809 			if (error)
   1810 				break;
   1811 
   1812 			switch (optval) {
   1813 			case IPV6_PORTRANGE_DEFAULT:
   1814 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1815 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1816 				break;
   1817 
   1818 			case IPV6_PORTRANGE_HIGH:
   1819 				in6p->in6p_flags &= ~(IN6P_LOWPORT);
   1820 				in6p->in6p_flags |= IN6P_HIGHPORT;
   1821 				break;
   1822 
   1823 			case IPV6_PORTRANGE_LOW:
   1824 				in6p->in6p_flags &= ~(IN6P_HIGHPORT);
   1825 				in6p->in6p_flags |= IN6P_LOWPORT;
   1826 				break;
   1827 
   1828 			default:
   1829 				error = EINVAL;
   1830 				break;
   1831 			}
   1832 			break;
   1833 
   1834 
   1835 #if defined(KAME_IPSEC) || defined(FAST_IPSEC)
   1836 		case IPV6_IPSEC_POLICY:
   1837 			error = ipsec6_set_policy(in6p, optname,
   1838 			    sopt->sopt_data, sopt->sopt_size, kauth_cred_get());
   1839 			break;
   1840 #endif /* IPSEC */
   1841 
   1842 		default:
   1843 			error = ENOPROTOOPT;
   1844 			break;
   1845 		}
   1846 		break;
   1847 
   1848 	case PRCO_GETOPT:
   1849 		switch (optname) {
   1850 #ifdef RFC2292
   1851 		case IPV6_2292PKTOPTIONS:
   1852 			/*
   1853 			 * RFC3542 (effectively) deprecated the
   1854 			 * semantics of the 2292-style pktoptions.
   1855 			 * Since it was not reliable in nature (i.e.,
   1856 			 * applications had to expect the lack of some
   1857 			 * information after all), it would make sense
   1858 			 * to simplify this part by always returning
   1859 			 * empty data.
   1860 			 */
   1861 			break;
   1862 #endif
   1863 
   1864 		case IPV6_RECVHOPOPTS:
   1865 		case IPV6_RECVDSTOPTS:
   1866 		case IPV6_RECVRTHDRDSTOPTS:
   1867 		case IPV6_UNICAST_HOPS:
   1868 		case IPV6_RECVPKTINFO:
   1869 		case IPV6_RECVHOPLIMIT:
   1870 		case IPV6_RECVRTHDR:
   1871 		case IPV6_RECVPATHMTU:
   1872 
   1873 		case IPV6_FAITH:
   1874 		case IPV6_V6ONLY:
   1875 		case IPV6_PORTRANGE:
   1876 		case IPV6_RECVTCLASS:
   1877 			switch (optname) {
   1878 
   1879 			case IPV6_RECVHOPOPTS:
   1880 				optval = OPTBIT(IN6P_HOPOPTS);
   1881 				break;
   1882 
   1883 			case IPV6_RECVDSTOPTS:
   1884 				optval = OPTBIT(IN6P_DSTOPTS);
   1885 				break;
   1886 
   1887 			case IPV6_RECVRTHDRDSTOPTS:
   1888 				optval = OPTBIT(IN6P_RTHDRDSTOPTS);
   1889 				break;
   1890 
   1891 			case IPV6_UNICAST_HOPS:
   1892 				optval = in6p->in6p_hops;
   1893 				break;
   1894 
   1895 			case IPV6_RECVPKTINFO:
   1896 				optval = OPTBIT(IN6P_PKTINFO);
   1897 				break;
   1898 
   1899 			case IPV6_RECVHOPLIMIT:
   1900 				optval = OPTBIT(IN6P_HOPLIMIT);
   1901 				break;
   1902 
   1903 			case IPV6_RECVRTHDR:
   1904 				optval = OPTBIT(IN6P_RTHDR);
   1905 				break;
   1906 
   1907 			case IPV6_RECVPATHMTU:
   1908 				optval = OPTBIT(IN6P_MTU);
   1909 				break;
   1910 
   1911 			case IPV6_FAITH:
   1912 				optval = OPTBIT(IN6P_FAITH);
   1913 				break;
   1914 
   1915 			case IPV6_V6ONLY:
   1916 				optval = OPTBIT(IN6P_IPV6_V6ONLY);
   1917 				break;
   1918 
   1919 			case IPV6_PORTRANGE:
   1920 			    {
   1921 				int flags;
   1922 				flags = in6p->in6p_flags;
   1923 				if (flags & IN6P_HIGHPORT)
   1924 					optval = IPV6_PORTRANGE_HIGH;
   1925 				else if (flags & IN6P_LOWPORT)
   1926 					optval = IPV6_PORTRANGE_LOW;
   1927 				else
   1928 					optval = 0;
   1929 				break;
   1930 			    }
   1931 			case IPV6_RECVTCLASS:
   1932 				optval = OPTBIT(IN6P_TCLASS);
   1933 				break;
   1934 
   1935 			}
   1936 			if (error)
   1937 				break;
   1938 			error = sockopt_setint(sopt, optval);
   1939 			break;
   1940 
   1941 		case IPV6_PATHMTU:
   1942 		    {
   1943 			u_long pmtu = 0;
   1944 			struct ip6_mtuinfo mtuinfo;
   1945 			struct route *ro = &in6p->in6p_route;
   1946 
   1947 			if (!(so->so_state & SS_ISCONNECTED))
   1948 				return (ENOTCONN);
   1949 			/*
   1950 			 * XXX: we dot not consider the case of source
   1951 			 * routing, or optional information to specify
   1952 			 * the outgoing interface.
   1953 			 */
   1954 			error = ip6_getpmtu(ro, NULL, NULL,
   1955 			    &in6p->in6p_faddr, &pmtu, NULL);
   1956 			if (error)
   1957 				break;
   1958 			if (pmtu > IPV6_MAXPACKET)
   1959 				pmtu = IPV6_MAXPACKET;
   1960 
   1961 			memset(&mtuinfo, 0, sizeof(mtuinfo));
   1962 			mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
   1963 			optdata = (void *)&mtuinfo;
   1964 			optdatalen = sizeof(mtuinfo);
   1965 			if (optdatalen > MCLBYTES)
   1966 				return (EMSGSIZE); /* XXX */
   1967 			error = sockopt_set(sopt, optdata, optdatalen);
   1968 			break;
   1969 		    }
   1970 
   1971 #ifdef RFC2292
   1972 		case IPV6_2292PKTINFO:
   1973 		case IPV6_2292HOPLIMIT:
   1974 		case IPV6_2292HOPOPTS:
   1975 		case IPV6_2292RTHDR:
   1976 		case IPV6_2292DSTOPTS:
   1977 			switch (optname) {
   1978 			case IPV6_2292PKTINFO:
   1979 				optval = OPTBIT(IN6P_PKTINFO);
   1980 				break;
   1981 			case IPV6_2292HOPLIMIT:
   1982 				optval = OPTBIT(IN6P_HOPLIMIT);
   1983 				break;
   1984 			case IPV6_2292HOPOPTS:
   1985 				optval = OPTBIT(IN6P_HOPOPTS);
   1986 				break;
   1987 			case IPV6_2292RTHDR:
   1988 				optval = OPTBIT(IN6P_RTHDR);
   1989 				break;
   1990 			case IPV6_2292DSTOPTS:
   1991 				optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
   1992 				break;
   1993 			}
   1994 			error = sockopt_setint(sopt, optval);
   1995 			break;
   1996 #endif
   1997 		case IPV6_PKTINFO:
   1998 		case IPV6_HOPOPTS:
   1999 		case IPV6_RTHDR:
   2000 		case IPV6_DSTOPTS:
   2001 		case IPV6_RTHDRDSTOPTS:
   2002 		case IPV6_NEXTHOP:
   2003 		case IPV6_OTCLASS:
   2004 		case IPV6_TCLASS:
   2005 		case IPV6_DONTFRAG:
   2006 		case IPV6_USE_MIN_MTU:
   2007 			error = ip6_getpcbopt(in6p->in6p_outputopts,
   2008 			    optname, sopt);
   2009 			break;
   2010 
   2011 		case IPV6_MULTICAST_IF:
   2012 		case IPV6_MULTICAST_HOPS:
   2013 		case IPV6_MULTICAST_LOOP:
   2014 		case IPV6_JOIN_GROUP:
   2015 		case IPV6_LEAVE_GROUP:
   2016 			error = ip6_getmoptions(sopt, in6p->in6p_moptions);
   2017 			break;
   2018 
   2019 #if defined(KAME_IPSEC) || defined(FAST_IPSEC)
   2020 		case IPV6_IPSEC_POLICY:
   2021 		    {
   2022 			struct mbuf *m = NULL;
   2023 
   2024 			/* XXX this will return EINVAL as sopt is empty */
   2025 			error = ipsec6_get_policy(in6p, sopt->sopt_data,
   2026 			    sopt->sopt_size, &m);
   2027 			if (!error)
   2028 				error = sockopt_setmbuf(sopt, m);
   2029 
   2030 			break;
   2031 		    }
   2032 #endif /* IPSEC */
   2033 
   2034 		default:
   2035 			error = ENOPROTOOPT;
   2036 			break;
   2037 		}
   2038 		break;
   2039 	}
   2040 	return (error);
   2041 }
   2042 
   2043 int
   2044 ip6_raw_ctloutput(int op, struct socket *so, struct sockopt *sopt)
   2045 {
   2046 	int error = 0, optval;
   2047 	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
   2048 	struct in6pcb *in6p = sotoin6pcb(so);
   2049 	int level, optname;
   2050 
   2051 	KASSERT(sopt != NULL);
   2052 
   2053 	level = sopt->sopt_level;
   2054 	optname = sopt->sopt_name;
   2055 
   2056 	if (level != IPPROTO_IPV6) {
   2057 		return ENOPROTOOPT;
   2058 	}
   2059 
   2060 	switch (optname) {
   2061 	case IPV6_CHECKSUM:
   2062 		/*
   2063 		 * For ICMPv6 sockets, no modification allowed for checksum
   2064 		 * offset, permit "no change" values to help existing apps.
   2065 		 *
   2066 		 * XXX RFC3542 says: "An attempt to set IPV6_CHECKSUM
   2067 		 * for an ICMPv6 socket will fail."  The current
   2068 		 * behavior does not meet RFC3542.
   2069 		 */
   2070 		switch (op) {
   2071 		case PRCO_SETOPT:
   2072 			error = sockopt_getint(sopt, &optval);
   2073 			if (error)
   2074 				break;
   2075 			if ((optval % 2) != 0) {
   2076 				/* the API assumes even offset values */
   2077 				error = EINVAL;
   2078 			} else if (so->so_proto->pr_protocol ==
   2079 			    IPPROTO_ICMPV6) {
   2080 				if (optval != icmp6off)
   2081 					error = EINVAL;
   2082 			} else
   2083 				in6p->in6p_cksum = optval;
   2084 			break;
   2085 
   2086 		case PRCO_GETOPT:
   2087 			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
   2088 				optval = icmp6off;
   2089 			else
   2090 				optval = in6p->in6p_cksum;
   2091 
   2092 			error = sockopt_setint(sopt, optval);
   2093 			break;
   2094 
   2095 		default:
   2096 			error = EINVAL;
   2097 			break;
   2098 		}
   2099 		break;
   2100 
   2101 	default:
   2102 		error = ENOPROTOOPT;
   2103 		break;
   2104 	}
   2105 
   2106 	return (error);
   2107 }
   2108 
   2109 #ifdef RFC2292
   2110 /*
   2111  * Set up IP6 options in pcb for insertion in output packets or
   2112  * specifying behavior of outgoing packets.
   2113  */
   2114 static int
   2115 ip6_pcbopts(struct ip6_pktopts **pktopt, struct socket *so,
   2116     struct sockopt *sopt)
   2117 {
   2118 	struct ip6_pktopts *opt = *pktopt;
   2119 	struct mbuf *m;
   2120 	int error = 0;
   2121 
   2122 	/* turn off any old options. */
   2123 	if (opt) {
   2124 #ifdef DIAGNOSTIC
   2125 	    if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
   2126 		opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
   2127 		opt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2128 		    printf("ip6_pcbopts: all specified options are cleared.\n");
   2129 #endif
   2130 		ip6_clearpktopts(opt, -1);
   2131 	} else {
   2132 		opt = malloc(sizeof(*opt), M_IP6OPT, M_NOWAIT);
   2133 		if (opt == NULL)
   2134 			return (ENOBUFS);
   2135 	}
   2136 	*pktopt = NULL;
   2137 
   2138 	if (sopt == NULL || sopt->sopt_size == 0) {
   2139 		/*
   2140 		 * Only turning off any previous options, regardless of
   2141 		 * whether the opt is just created or given.
   2142 		 */
   2143 		free(opt, M_IP6OPT);
   2144 		return (0);
   2145 	}
   2146 
   2147 	/*  set options specified by user. */
   2148 	m = sockopt_getmbuf(sopt);
   2149 	if (m == NULL) {
   2150 		free(opt, M_IP6OPT);
   2151 		return (ENOBUFS);
   2152 	}
   2153 
   2154 	error = ip6_setpktopts(m, opt, NULL, kauth_cred_get(),
   2155 	    so->so_proto->pr_protocol);
   2156 	m_freem(m);
   2157 	if (error != 0) {
   2158 		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
   2159 		free(opt, M_IP6OPT);
   2160 		return (error);
   2161 	}
   2162 	*pktopt = opt;
   2163 	return (0);
   2164 }
   2165 #endif
   2166 
   2167 /*
   2168  * initialize ip6_pktopts.  beware that there are non-zero default values in
   2169  * the struct.
   2170  */
   2171 void
   2172 ip6_initpktopts(struct ip6_pktopts *opt)
   2173 {
   2174 
   2175 	memset(opt, 0, sizeof(*opt));
   2176 	opt->ip6po_hlim = -1;	/* -1 means default hop limit */
   2177 	opt->ip6po_tclass = -1;	/* -1 means default traffic class */
   2178 	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
   2179 }
   2180 
   2181 #define sin6tosa(sin6)	((struct sockaddr *)(sin6)) /* XXX */
   2182 static int
   2183 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
   2184     kauth_cred_t cred, int uproto)
   2185 {
   2186 	struct ip6_pktopts *opt;
   2187 
   2188 	if (*pktopt == NULL) {
   2189 		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
   2190 		    M_NOWAIT);
   2191 		if (*pktopt == NULL)
   2192 			return (ENOBUFS);
   2193 
   2194 		ip6_initpktopts(*pktopt);
   2195 	}
   2196 	opt = *pktopt;
   2197 
   2198 	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
   2199 }
   2200 
   2201 static int
   2202 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
   2203 {
   2204 	void *optdata = NULL;
   2205 	int optdatalen = 0;
   2206 	struct ip6_ext *ip6e;
   2207 	int error = 0;
   2208 	struct in6_pktinfo null_pktinfo;
   2209 	int deftclass = 0, on;
   2210 	int defminmtu = IP6PO_MINMTU_MCASTONLY;
   2211 
   2212 	switch (optname) {
   2213 	case IPV6_PKTINFO:
   2214 		if (pktopt && pktopt->ip6po_pktinfo)
   2215 			optdata = (void *)pktopt->ip6po_pktinfo;
   2216 		else {
   2217 			/* XXX: we don't have to do this every time... */
   2218 			memset(&null_pktinfo, 0, sizeof(null_pktinfo));
   2219 			optdata = (void *)&null_pktinfo;
   2220 		}
   2221 		optdatalen = sizeof(struct in6_pktinfo);
   2222 		break;
   2223 	case IPV6_OTCLASS:
   2224 		/* XXX */
   2225 		return (EINVAL);
   2226 	case IPV6_TCLASS:
   2227 		if (pktopt && pktopt->ip6po_tclass >= 0)
   2228 			optdata = (void *)&pktopt->ip6po_tclass;
   2229 		else
   2230 			optdata = (void *)&deftclass;
   2231 		optdatalen = sizeof(int);
   2232 		break;
   2233 	case IPV6_HOPOPTS:
   2234 		if (pktopt && pktopt->ip6po_hbh) {
   2235 			optdata = (void *)pktopt->ip6po_hbh;
   2236 			ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
   2237 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2238 		}
   2239 		break;
   2240 	case IPV6_RTHDR:
   2241 		if (pktopt && pktopt->ip6po_rthdr) {
   2242 			optdata = (void *)pktopt->ip6po_rthdr;
   2243 			ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
   2244 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2245 		}
   2246 		break;
   2247 	case IPV6_RTHDRDSTOPTS:
   2248 		if (pktopt && pktopt->ip6po_dest1) {
   2249 			optdata = (void *)pktopt->ip6po_dest1;
   2250 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
   2251 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2252 		}
   2253 		break;
   2254 	case IPV6_DSTOPTS:
   2255 		if (pktopt && pktopt->ip6po_dest2) {
   2256 			optdata = (void *)pktopt->ip6po_dest2;
   2257 			ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
   2258 			optdatalen = (ip6e->ip6e_len + 1) << 3;
   2259 		}
   2260 		break;
   2261 	case IPV6_NEXTHOP:
   2262 		if (pktopt && pktopt->ip6po_nexthop) {
   2263 			optdata = (void *)pktopt->ip6po_nexthop;
   2264 			optdatalen = pktopt->ip6po_nexthop->sa_len;
   2265 		}
   2266 		break;
   2267 	case IPV6_USE_MIN_MTU:
   2268 		if (pktopt)
   2269 			optdata = (void *)&pktopt->ip6po_minmtu;
   2270 		else
   2271 			optdata = (void *)&defminmtu;
   2272 		optdatalen = sizeof(int);
   2273 		break;
   2274 	case IPV6_DONTFRAG:
   2275 		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
   2276 			on = 1;
   2277 		else
   2278 			on = 0;
   2279 		optdata = (void *)&on;
   2280 		optdatalen = sizeof(on);
   2281 		break;
   2282 	default:		/* should not happen */
   2283 #ifdef DIAGNOSTIC
   2284 		panic("ip6_getpcbopt: unexpected option\n");
   2285 #endif
   2286 		return (ENOPROTOOPT);
   2287 	}
   2288 
   2289 	error = sockopt_set(sopt, optdata, optdatalen);
   2290 
   2291 	return (error);
   2292 }
   2293 
   2294 void
   2295 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
   2296 {
   2297 	if (optname == -1 || optname == IPV6_PKTINFO) {
   2298 		if (pktopt->ip6po_pktinfo)
   2299 			free(pktopt->ip6po_pktinfo, M_IP6OPT);
   2300 		pktopt->ip6po_pktinfo = NULL;
   2301 	}
   2302 	if (optname == -1 || optname == IPV6_HOPLIMIT)
   2303 		pktopt->ip6po_hlim = -1;
   2304 	if (optname == -1 || optname == IPV6_TCLASS)
   2305 		pktopt->ip6po_tclass = -1;
   2306 	if (optname == -1 || optname == IPV6_NEXTHOP) {
   2307 		rtcache_free(&pktopt->ip6po_nextroute);
   2308 		if (pktopt->ip6po_nexthop)
   2309 			free(pktopt->ip6po_nexthop, M_IP6OPT);
   2310 		pktopt->ip6po_nexthop = NULL;
   2311 	}
   2312 	if (optname == -1 || optname == IPV6_HOPOPTS) {
   2313 		if (pktopt->ip6po_hbh)
   2314 			free(pktopt->ip6po_hbh, M_IP6OPT);
   2315 		pktopt->ip6po_hbh = NULL;
   2316 	}
   2317 	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
   2318 		if (pktopt->ip6po_dest1)
   2319 			free(pktopt->ip6po_dest1, M_IP6OPT);
   2320 		pktopt->ip6po_dest1 = NULL;
   2321 	}
   2322 	if (optname == -1 || optname == IPV6_RTHDR) {
   2323 		if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
   2324 			free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
   2325 		pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
   2326 		rtcache_free(&pktopt->ip6po_route);
   2327 	}
   2328 	if (optname == -1 || optname == IPV6_DSTOPTS) {
   2329 		if (pktopt->ip6po_dest2)
   2330 			free(pktopt->ip6po_dest2, M_IP6OPT);
   2331 		pktopt->ip6po_dest2 = NULL;
   2332 	}
   2333 }
   2334 
   2335 #define PKTOPT_EXTHDRCPY(type) 					\
   2336 do {								\
   2337 	if (src->type) {					\
   2338 		int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
   2339 		dst->type = malloc(hlen, M_IP6OPT, canwait);	\
   2340 		if (dst->type == NULL && canwait == M_NOWAIT)	\
   2341 			goto bad;				\
   2342 		memcpy(dst->type, src->type, hlen);		\
   2343 	}							\
   2344 } while (/*CONSTCOND*/ 0)
   2345 
   2346 static int
   2347 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
   2348 {
   2349 	dst->ip6po_hlim = src->ip6po_hlim;
   2350 	dst->ip6po_tclass = src->ip6po_tclass;
   2351 	dst->ip6po_flags = src->ip6po_flags;
   2352 	if (src->ip6po_pktinfo) {
   2353 		dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
   2354 		    M_IP6OPT, canwait);
   2355 		if (dst->ip6po_pktinfo == NULL && canwait == M_NOWAIT)
   2356 			goto bad;
   2357 		*dst->ip6po_pktinfo = *src->ip6po_pktinfo;
   2358 	}
   2359 	if (src->ip6po_nexthop) {
   2360 		dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
   2361 		    M_IP6OPT, canwait);
   2362 		if (dst->ip6po_nexthop == NULL && canwait == M_NOWAIT)
   2363 			goto bad;
   2364 		memcpy(dst->ip6po_nexthop, src->ip6po_nexthop,
   2365 		    src->ip6po_nexthop->sa_len);
   2366 	}
   2367 	PKTOPT_EXTHDRCPY(ip6po_hbh);
   2368 	PKTOPT_EXTHDRCPY(ip6po_dest1);
   2369 	PKTOPT_EXTHDRCPY(ip6po_dest2);
   2370 	PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
   2371 	return (0);
   2372 
   2373   bad:
   2374 	if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
   2375 	if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
   2376 	if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
   2377 	if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
   2378 	if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
   2379 	if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
   2380 
   2381 	return (ENOBUFS);
   2382 }
   2383 #undef PKTOPT_EXTHDRCPY
   2384 
   2385 struct ip6_pktopts *
   2386 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
   2387 {
   2388 	int error;
   2389 	struct ip6_pktopts *dst;
   2390 
   2391 	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
   2392 	if (dst == NULL && canwait == M_NOWAIT)
   2393 		return (NULL);
   2394 	ip6_initpktopts(dst);
   2395 
   2396 	if ((error = copypktopts(dst, src, canwait)) != 0) {
   2397 		free(dst, M_IP6OPT);
   2398 		return (NULL);
   2399 	}
   2400 
   2401 	return (dst);
   2402 }
   2403 
   2404 void
   2405 ip6_freepcbopts(struct ip6_pktopts *pktopt)
   2406 {
   2407 	if (pktopt == NULL)
   2408 		return;
   2409 
   2410 	ip6_clearpktopts(pktopt, -1);
   2411 
   2412 	free(pktopt, M_IP6OPT);
   2413 }
   2414 
   2415 /*
   2416  * Set the IP6 multicast options in response to user setsockopt().
   2417  */
   2418 static int
   2419 ip6_setmoptions(const struct sockopt *sopt, struct ip6_moptions **im6op)
   2420 {
   2421 	int error = 0;
   2422 	u_int loop, ifindex;
   2423 	struct ipv6_mreq mreq;
   2424 	struct ifnet *ifp;
   2425 	struct ip6_moptions *im6o = *im6op;
   2426 	struct route ro;
   2427 	struct in6_multi_mship *imm;
   2428 	struct lwp *l = curlwp;	/* XXX */
   2429 
   2430 	if (im6o == NULL) {
   2431 		/*
   2432 		 * No multicast option buffer attached to the pcb;
   2433 		 * allocate one and initialize to default values.
   2434 		 */
   2435 		im6o = malloc(sizeof(*im6o), M_IPMOPTS, M_NOWAIT);
   2436 		if (im6o == NULL)
   2437 			return (ENOBUFS);
   2438 
   2439 		*im6op = im6o;
   2440 		im6o->im6o_multicast_ifp = NULL;
   2441 		im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2442 		im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
   2443 		LIST_INIT(&im6o->im6o_memberships);
   2444 	}
   2445 
   2446 	switch (sopt->sopt_name) {
   2447 
   2448 	case IPV6_MULTICAST_IF:
   2449 		/*
   2450 		 * Select the interface for outgoing multicast packets.
   2451 		 */
   2452 		error = sockopt_get(sopt, &ifindex, sizeof(ifindex));
   2453 		if (error != 0)
   2454 			break;
   2455 
   2456 		if (ifindex != 0) {
   2457 			if (if_indexlim <= ifindex || !ifindex2ifnet[ifindex]) {
   2458 				error = ENXIO;	/* XXX EINVAL? */
   2459 				break;
   2460 			}
   2461 			ifp = ifindex2ifnet[ifindex];
   2462 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
   2463 				error = EADDRNOTAVAIL;
   2464 				break;
   2465 			}
   2466 		} else
   2467 			ifp = NULL;
   2468 		im6o->im6o_multicast_ifp = ifp;
   2469 		break;
   2470 
   2471 	case IPV6_MULTICAST_HOPS:
   2472 	    {
   2473 		/*
   2474 		 * Set the IP6 hoplimit for outgoing multicast packets.
   2475 		 */
   2476 		int optval;
   2477 
   2478 		error = sockopt_getint(sopt, &optval);
   2479 		if (error != 0)
   2480 			break;
   2481 
   2482 		if (optval < -1 || optval >= 256)
   2483 			error = EINVAL;
   2484 		else if (optval == -1)
   2485 			im6o->im6o_multicast_hlim = ip6_defmcasthlim;
   2486 		else
   2487 			im6o->im6o_multicast_hlim = optval;
   2488 		break;
   2489 	    }
   2490 
   2491 	case IPV6_MULTICAST_LOOP:
   2492 		/*
   2493 		 * Set the loopback flag for outgoing multicast packets.
   2494 		 * Must be zero or one.
   2495 		 */
   2496 		error = sockopt_get(sopt, &loop, sizeof(loop));
   2497 		if (error != 0)
   2498 			break;
   2499 		if (loop > 1) {
   2500 			error = EINVAL;
   2501 			break;
   2502 		}
   2503 		im6o->im6o_multicast_loop = loop;
   2504 		break;
   2505 
   2506 	case IPV6_JOIN_GROUP:
   2507 		/*
   2508 		 * Add a multicast group membership.
   2509 		 * Group must be a valid IP6 multicast address.
   2510 		 */
   2511 		error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2512 		if (error != 0)
   2513 			break;
   2514 
   2515 		if (IN6_IS_ADDR_UNSPECIFIED(&mreq.ipv6mr_multiaddr)) {
   2516 			/*
   2517 			 * We use the unspecified address to specify to accept
   2518 			 * all multicast addresses. Only super user is allowed
   2519 			 * to do this.
   2520 			 */
   2521 			if (kauth_authorize_generic(l->l_cred,
   2522 			    KAUTH_GENERIC_ISSUSER, NULL))
   2523 			{
   2524 				error = EACCES;
   2525 				break;
   2526 			}
   2527 		} else if (!IN6_IS_ADDR_MULTICAST(&mreq.ipv6mr_multiaddr)) {
   2528 			error = EINVAL;
   2529 			break;
   2530 		}
   2531 
   2532 		/*
   2533 		 * If no interface was explicitly specified, choose an
   2534 		 * appropriate one according to the given multicast address.
   2535 		 */
   2536 		if (mreq.ipv6mr_interface == 0) {
   2537 			struct rtentry *rt;
   2538 			union {
   2539 				struct sockaddr		dst;
   2540 				struct sockaddr_in6	dst6;
   2541 			} u;
   2542 
   2543 			/*
   2544 			 * Look up the routing table for the
   2545 			 * address, and choose the outgoing interface.
   2546 			 *   XXX: is it a good approach?
   2547 			 */
   2548 			memset(&ro, 0, sizeof(ro));
   2549 			sockaddr_in6_init(&u.dst6, &mreq.ipv6mr_multiaddr, 0,
   2550 			    0, 0);
   2551 			rtcache_setdst(&ro, &u.dst);
   2552 			ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp
   2553 			                                        : NULL;
   2554 			rtcache_free(&ro);
   2555 		} else {
   2556 			/*
   2557 			 * If the interface is specified, validate it.
   2558 			 */
   2559 			if (if_indexlim <= mreq.ipv6mr_interface ||
   2560 			    !ifindex2ifnet[mreq.ipv6mr_interface]) {
   2561 				error = ENXIO;	/* XXX EINVAL? */
   2562 				break;
   2563 			}
   2564 			ifp = ifindex2ifnet[mreq.ipv6mr_interface];
   2565 		}
   2566 
   2567 		/*
   2568 		 * See if we found an interface, and confirm that it
   2569 		 * supports multicast
   2570 		 */
   2571 		if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
   2572 			error = EADDRNOTAVAIL;
   2573 			break;
   2574 		}
   2575 
   2576 		if (in6_setscope(&mreq.ipv6mr_multiaddr, ifp, NULL)) {
   2577 			error = EADDRNOTAVAIL; /* XXX: should not happen */
   2578 			break;
   2579 		}
   2580 
   2581 		/*
   2582 		 * See if the membership already exists.
   2583 		 */
   2584 		for (imm = im6o->im6o_memberships.lh_first;
   2585 		     imm != NULL; imm = imm->i6mm_chain.le_next)
   2586 			if (imm->i6mm_maddr->in6m_ifp == ifp &&
   2587 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2588 			    &mreq.ipv6mr_multiaddr))
   2589 				break;
   2590 		if (imm != NULL) {
   2591 			error = EADDRINUSE;
   2592 			break;
   2593 		}
   2594 		/*
   2595 		 * Everything looks good; add a new record to the multicast
   2596 		 * address list for the given interface.
   2597 		 */
   2598 		imm = in6_joingroup(ifp, &mreq.ipv6mr_multiaddr, &error, 0);
   2599 		if (imm == NULL)
   2600 			break;
   2601 		LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
   2602 		break;
   2603 
   2604 	case IPV6_LEAVE_GROUP:
   2605 		/*
   2606 		 * Drop a multicast group membership.
   2607 		 * Group must be a valid IP6 multicast address.
   2608 		 */
   2609 		error = sockopt_get(sopt, &mreq, sizeof(mreq));
   2610 		if (error != 0)
   2611 			break;
   2612 
   2613 		/*
   2614 		 * If an interface address was specified, get a pointer
   2615 		 * to its ifnet structure.
   2616 		 */
   2617 		if (mreq.ipv6mr_interface != 0) {
   2618 			if (if_indexlim <= mreq.ipv6mr_interface ||
   2619 			    !ifindex2ifnet[mreq.ipv6mr_interface]) {
   2620 				error = ENXIO;	/* XXX EINVAL? */
   2621 				break;
   2622 			}
   2623 			ifp = ifindex2ifnet[mreq.ipv6mr_interface];
   2624 		} else
   2625 			ifp = NULL;
   2626 
   2627 		/* Fill in the scope zone ID */
   2628 		if (ifp) {
   2629 			if (in6_setscope(&mreq.ipv6mr_multiaddr, ifp, NULL)) {
   2630 				/* XXX: should not happen */
   2631 				error = EADDRNOTAVAIL;
   2632 				break;
   2633 			}
   2634 		} else if (mreq.ipv6mr_interface != 0) {
   2635 			/*
   2636 			 * XXX: This case would happens when the (positive)
   2637 			 * index is in the valid range, but the corresponding
   2638 			 * interface has been detached dynamically.  The above
   2639 			 * check probably avoids such case to happen here, but
   2640 			 * we check it explicitly for safety.
   2641 			 */
   2642 			error = EADDRNOTAVAIL;
   2643 			break;
   2644 		} else {	/* ipv6mr_interface == 0 */
   2645 			struct sockaddr_in6 sa6_mc;
   2646 
   2647 			/*
   2648 			 * The API spec says as follows:
   2649 			 *  If the interface index is specified as 0, the
   2650 			 *  system may choose a multicast group membership to
   2651 			 *  drop by matching the multicast address only.
   2652 			 * On the other hand, we cannot disambiguate the scope
   2653 			 * zone unless an interface is provided.  Thus, we
   2654 			 * check if there's ambiguity with the default scope
   2655 			 * zone as the last resort.
   2656 			 */
   2657 			sockaddr_in6_init(&sa6_mc, &mreq.ipv6mr_multiaddr,
   2658 			    0, 0, 0);
   2659 			error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
   2660 			if (error != 0)
   2661 				break;
   2662 			mreq.ipv6mr_multiaddr = sa6_mc.sin6_addr;
   2663 		}
   2664 
   2665 		/*
   2666 		 * Find the membership in the membership list.
   2667 		 */
   2668 		for (imm = im6o->im6o_memberships.lh_first;
   2669 		     imm != NULL; imm = imm->i6mm_chain.le_next) {
   2670 			if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
   2671 			    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
   2672 			    &mreq.ipv6mr_multiaddr))
   2673 				break;
   2674 		}
   2675 		if (imm == NULL) {
   2676 			/* Unable to resolve interface */
   2677 			error = EADDRNOTAVAIL;
   2678 			break;
   2679 		}
   2680 		/*
   2681 		 * Give up the multicast address record to which the
   2682 		 * membership points.
   2683 		 */
   2684 		LIST_REMOVE(imm, i6mm_chain);
   2685 		in6_leavegroup(imm);
   2686 		break;
   2687 
   2688 	default:
   2689 		error = EOPNOTSUPP;
   2690 		break;
   2691 	}
   2692 
   2693 	/*
   2694 	 * If all options have default values, no need to keep the mbuf.
   2695 	 */
   2696 	if (im6o->im6o_multicast_ifp == NULL &&
   2697 	    im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
   2698 	    im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
   2699 	    im6o->im6o_memberships.lh_first == NULL) {
   2700 		free(*im6op, M_IPMOPTS);
   2701 		*im6op = NULL;
   2702 	}
   2703 
   2704 	return (error);
   2705 }
   2706 
   2707 /*
   2708  * Return the IP6 multicast options in response to user getsockopt().
   2709  */
   2710 static int
   2711 ip6_getmoptions(struct sockopt *sopt, struct ip6_moptions *im6o)
   2712 {
   2713 	u_int optval;
   2714 	int error;
   2715 
   2716 	switch (sopt->sopt_name) {
   2717 	case IPV6_MULTICAST_IF:
   2718 		if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
   2719 			optval = 0;
   2720 		else
   2721 			optval = im6o->im6o_multicast_ifp->if_index;
   2722 
   2723 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2724 		break;
   2725 
   2726 	case IPV6_MULTICAST_HOPS:
   2727 		if (im6o == NULL)
   2728 			optval = ip6_defmcasthlim;
   2729 		else
   2730 			optval = im6o->im6o_multicast_hlim;
   2731 
   2732 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2733 		break;
   2734 
   2735 	case IPV6_MULTICAST_LOOP:
   2736 		if (im6o == NULL)
   2737 			optval = ip6_defmcasthlim;
   2738 		else
   2739 			optval = im6o->im6o_multicast_loop;
   2740 
   2741 		error = sockopt_set(sopt, &optval, sizeof(optval));
   2742 		break;
   2743 
   2744 	default:
   2745 		error = EOPNOTSUPP;
   2746 	}
   2747 
   2748 	return (error);
   2749 }
   2750 
   2751 /*
   2752  * Discard the IP6 multicast options.
   2753  */
   2754 void
   2755 ip6_freemoptions(struct ip6_moptions *im6o)
   2756 {
   2757 	struct in6_multi_mship *imm;
   2758 
   2759 	if (im6o == NULL)
   2760 		return;
   2761 
   2762 	while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
   2763 		LIST_REMOVE(imm, i6mm_chain);
   2764 		in6_leavegroup(imm);
   2765 	}
   2766 	free(im6o, M_IPMOPTS);
   2767 }
   2768 
   2769 /*
   2770  * Set IPv6 outgoing packet options based on advanced API.
   2771  */
   2772 int
   2773 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
   2774 	struct ip6_pktopts *stickyopt, kauth_cred_t cred, int uproto)
   2775 {
   2776 	struct cmsghdr *cm = 0;
   2777 
   2778 	if (control == NULL || opt == NULL)
   2779 		return (EINVAL);
   2780 
   2781 	ip6_initpktopts(opt);
   2782 	if (stickyopt) {
   2783 		int error;
   2784 
   2785 		/*
   2786 		 * If stickyopt is provided, make a local copy of the options
   2787 		 * for this particular packet, then override them by ancillary
   2788 		 * objects.
   2789 		 * XXX: copypktopts() does not copy the cached route to a next
   2790 		 * hop (if any).  This is not very good in terms of efficiency,
   2791 		 * but we can allow this since this option should be rarely
   2792 		 * used.
   2793 		 */
   2794 		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
   2795 			return (error);
   2796 	}
   2797 
   2798 	/*
   2799 	 * XXX: Currently, we assume all the optional information is stored
   2800 	 * in a single mbuf.
   2801 	 */
   2802 	if (control->m_next)
   2803 		return (EINVAL);
   2804 
   2805 	/* XXX if cm->cmsg_len is not aligned, control->m_len can become <0 */
   2806 	for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
   2807 	    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
   2808 		int error;
   2809 
   2810 		if (control->m_len < CMSG_LEN(0))
   2811 			return (EINVAL);
   2812 
   2813 		cm = mtod(control, struct cmsghdr *);
   2814 		if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
   2815 			return (EINVAL);
   2816 		if (cm->cmsg_level != IPPROTO_IPV6)
   2817 			continue;
   2818 
   2819 		error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
   2820 		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
   2821 		if (error)
   2822 			return (error);
   2823 	}
   2824 
   2825 	return (0);
   2826 }
   2827 
   2828 /*
   2829  * Set a particular packet option, as a sticky option or an ancillary data
   2830  * item.  "len" can be 0 only when it's a sticky option.
   2831  * We have 4 cases of combination of "sticky" and "cmsg":
   2832  * "sticky=0, cmsg=0": impossible
   2833  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
   2834  * "sticky=1, cmsg=0": RFC3542 socket option
   2835  * "sticky=1, cmsg=1": RFC2292 socket option
   2836  */
   2837 static int
   2838 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
   2839     kauth_cred_t cred, int sticky, int cmsg, int uproto)
   2840 {
   2841 	int minmtupolicy;
   2842 	int error;
   2843 
   2844 	if (!sticky && !cmsg) {
   2845 #ifdef DIAGNOSTIC
   2846 		printf("ip6_setpktopt: impossible case\n");
   2847 #endif
   2848 		return (EINVAL);
   2849 	}
   2850 
   2851 	/*
   2852 	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
   2853 	 * not be specified in the context of RFC3542.  Conversely,
   2854 	 * RFC3542 types should not be specified in the context of RFC2292.
   2855 	 */
   2856 	if (!cmsg) {
   2857 		switch (optname) {
   2858 		case IPV6_2292PKTINFO:
   2859 		case IPV6_2292HOPLIMIT:
   2860 		case IPV6_2292NEXTHOP:
   2861 		case IPV6_2292HOPOPTS:
   2862 		case IPV6_2292DSTOPTS:
   2863 		case IPV6_2292RTHDR:
   2864 		case IPV6_2292PKTOPTIONS:
   2865 			return (ENOPROTOOPT);
   2866 		}
   2867 	}
   2868 	if (sticky && cmsg) {
   2869 		switch (optname) {
   2870 		case IPV6_PKTINFO:
   2871 		case IPV6_HOPLIMIT:
   2872 		case IPV6_NEXTHOP:
   2873 		case IPV6_HOPOPTS:
   2874 		case IPV6_DSTOPTS:
   2875 		case IPV6_RTHDRDSTOPTS:
   2876 		case IPV6_RTHDR:
   2877 		case IPV6_USE_MIN_MTU:
   2878 		case IPV6_DONTFRAG:
   2879 		case IPV6_OTCLASS:
   2880 		case IPV6_TCLASS:
   2881 			return (ENOPROTOOPT);
   2882 		}
   2883 	}
   2884 
   2885 	switch (optname) {
   2886 #ifdef RFC2292
   2887 	case IPV6_2292PKTINFO:
   2888 #endif
   2889 	case IPV6_PKTINFO:
   2890 	{
   2891 		struct ifnet *ifp = NULL;
   2892 		struct in6_pktinfo *pktinfo;
   2893 
   2894 		if (len != sizeof(struct in6_pktinfo))
   2895 			return (EINVAL);
   2896 
   2897 		pktinfo = (struct in6_pktinfo *)buf;
   2898 
   2899 		/*
   2900 		 * An application can clear any sticky IPV6_PKTINFO option by
   2901 		 * doing a "regular" setsockopt with ipi6_addr being
   2902 		 * in6addr_any and ipi6_ifindex being zero.
   2903 		 * [RFC 3542, Section 6]
   2904 		 */
   2905 		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
   2906 		    pktinfo->ipi6_ifindex == 0 &&
   2907 		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2908 			ip6_clearpktopts(opt, optname);
   2909 			break;
   2910 		}
   2911 
   2912 		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
   2913 		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
   2914 			return (EINVAL);
   2915 		}
   2916 
   2917 		/* validate the interface index if specified. */
   2918 		if (pktinfo->ipi6_ifindex >= if_indexlim) {
   2919 			 return (ENXIO);
   2920 		}
   2921 		if (pktinfo->ipi6_ifindex) {
   2922 			ifp = ifindex2ifnet[pktinfo->ipi6_ifindex];
   2923 			if (ifp == NULL)
   2924 				return (ENXIO);
   2925 		}
   2926 
   2927 		/*
   2928 		 * We store the address anyway, and let in6_selectsrc()
   2929 		 * validate the specified address.  This is because ipi6_addr
   2930 		 * may not have enough information about its scope zone, and
   2931 		 * we may need additional information (such as outgoing
   2932 		 * interface or the scope zone of a destination address) to
   2933 		 * disambiguate the scope.
   2934 		 * XXX: the delay of the validation may confuse the
   2935 		 * application when it is used as a sticky option.
   2936 		 */
   2937 		if (opt->ip6po_pktinfo == NULL) {
   2938 			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
   2939 			    M_IP6OPT, M_NOWAIT);
   2940 			if (opt->ip6po_pktinfo == NULL)
   2941 				return (ENOBUFS);
   2942 		}
   2943 		memcpy(opt->ip6po_pktinfo, pktinfo, sizeof(*pktinfo));
   2944 		break;
   2945 	}
   2946 
   2947 #ifdef RFC2292
   2948 	case IPV6_2292HOPLIMIT:
   2949 #endif
   2950 	case IPV6_HOPLIMIT:
   2951 	{
   2952 		int *hlimp;
   2953 
   2954 		/*
   2955 		 * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
   2956 		 * to simplify the ordering among hoplimit options.
   2957 		 */
   2958 		if (optname == IPV6_HOPLIMIT && sticky)
   2959 			return (ENOPROTOOPT);
   2960 
   2961 		if (len != sizeof(int))
   2962 			return (EINVAL);
   2963 		hlimp = (int *)buf;
   2964 		if (*hlimp < -1 || *hlimp > 255)
   2965 			return (EINVAL);
   2966 
   2967 		opt->ip6po_hlim = *hlimp;
   2968 		break;
   2969 	}
   2970 
   2971 	case IPV6_OTCLASS:
   2972 		if (len != sizeof(u_int8_t))
   2973 			return (EINVAL);
   2974 
   2975 		opt->ip6po_tclass = *(u_int8_t *)buf;
   2976 		break;
   2977 
   2978 	case IPV6_TCLASS:
   2979 	{
   2980 		int tclass;
   2981 
   2982 		if (len != sizeof(int))
   2983 			return (EINVAL);
   2984 		tclass = *(int *)buf;
   2985 		if (tclass < -1 || tclass > 255)
   2986 			return (EINVAL);
   2987 
   2988 		opt->ip6po_tclass = tclass;
   2989 		break;
   2990 	}
   2991 
   2992 #ifdef RFC2292
   2993 	case IPV6_2292NEXTHOP:
   2994 #endif
   2995 	case IPV6_NEXTHOP:
   2996 		error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER,
   2997 		    NULL);
   2998 		if (error)
   2999 			return (error);
   3000 
   3001 		if (len == 0) {	/* just remove the option */
   3002 			ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3003 			break;
   3004 		}
   3005 
   3006 		/* check if cmsg_len is large enough for sa_len */
   3007 		if (len < sizeof(struct sockaddr) || len < *buf)
   3008 			return (EINVAL);
   3009 
   3010 		switch (((struct sockaddr *)buf)->sa_family) {
   3011 		case AF_INET6:
   3012 		{
   3013 			struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
   3014 
   3015 			if (sa6->sin6_len != sizeof(struct sockaddr_in6))
   3016 				return (EINVAL);
   3017 
   3018 			if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
   3019 			    IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
   3020 				return (EINVAL);
   3021 			}
   3022 			if ((error = sa6_embedscope(sa6, ip6_use_defzone))
   3023 			    != 0) {
   3024 				return (error);
   3025 			}
   3026 			break;
   3027 		}
   3028 		case AF_LINK:	/* eventually be supported? */
   3029 		default:
   3030 			return (EAFNOSUPPORT);
   3031 		}
   3032 
   3033 		/* turn off the previous option, then set the new option. */
   3034 		ip6_clearpktopts(opt, IPV6_NEXTHOP);
   3035 		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
   3036 		if (opt->ip6po_nexthop == NULL)
   3037 			return (ENOBUFS);
   3038 		memcpy(opt->ip6po_nexthop, buf, *buf);
   3039 		break;
   3040 
   3041 #ifdef RFC2292
   3042 	case IPV6_2292HOPOPTS:
   3043 #endif
   3044 	case IPV6_HOPOPTS:
   3045 	{
   3046 		struct ip6_hbh *hbh;
   3047 		int hbhlen;
   3048 
   3049 		/*
   3050 		 * XXX: We don't allow a non-privileged user to set ANY HbH
   3051 		 * options, since per-option restriction has too much
   3052 		 * overhead.
   3053 		 */
   3054 		error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER,
   3055 		    NULL);
   3056 		if (error)
   3057 			return (error);
   3058 
   3059 		if (len == 0) {
   3060 			ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3061 			break;	/* just remove the option */
   3062 		}
   3063 
   3064 		/* message length validation */
   3065 		if (len < sizeof(struct ip6_hbh))
   3066 			return (EINVAL);
   3067 		hbh = (struct ip6_hbh *)buf;
   3068 		hbhlen = (hbh->ip6h_len + 1) << 3;
   3069 		if (len != hbhlen)
   3070 			return (EINVAL);
   3071 
   3072 		/* turn off the previous option, then set the new option. */
   3073 		ip6_clearpktopts(opt, IPV6_HOPOPTS);
   3074 		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
   3075 		if (opt->ip6po_hbh == NULL)
   3076 			return (ENOBUFS);
   3077 		memcpy(opt->ip6po_hbh, hbh, hbhlen);
   3078 
   3079 		break;
   3080 	}
   3081 
   3082 #ifdef RFC2292
   3083 	case IPV6_2292DSTOPTS:
   3084 #endif
   3085 	case IPV6_DSTOPTS:
   3086 	case IPV6_RTHDRDSTOPTS:
   3087 	{
   3088 		struct ip6_dest *dest, **newdest = NULL;
   3089 		int destlen;
   3090 
   3091 		/* XXX: see the comment for IPV6_HOPOPTS */
   3092 		error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER,
   3093 		    NULL);
   3094 		if (error)
   3095 			return (error);
   3096 
   3097 		if (len == 0) {
   3098 			ip6_clearpktopts(opt, optname);
   3099 			break;	/* just remove the option */
   3100 		}
   3101 
   3102 		/* message length validation */
   3103 		if (len < sizeof(struct ip6_dest))
   3104 			return (EINVAL);
   3105 		dest = (struct ip6_dest *)buf;
   3106 		destlen = (dest->ip6d_len + 1) << 3;
   3107 		if (len != destlen)
   3108 			return (EINVAL);
   3109 		/*
   3110 		 * Determine the position that the destination options header
   3111 		 * should be inserted; before or after the routing header.
   3112 		 */
   3113 		switch (optname) {
   3114 		case IPV6_2292DSTOPTS:
   3115 			/*
   3116 			 * The old advanced API is ambiguous on this point.
   3117 			 * Our approach is to determine the position based
   3118 			 * according to the existence of a routing header.
   3119 			 * Note, however, that this depends on the order of the
   3120 			 * extension headers in the ancillary data; the 1st
   3121 			 * part of the destination options header must appear
   3122 			 * before the routing header in the ancillary data,
   3123 			 * too.
   3124 			 * RFC3542 solved the ambiguity by introducing
   3125 			 * separate ancillary data or option types.
   3126 			 */
   3127 			if (opt->ip6po_rthdr == NULL)
   3128 				newdest = &opt->ip6po_dest1;
   3129 			else
   3130 				newdest = &opt->ip6po_dest2;
   3131 			break;
   3132 		case IPV6_RTHDRDSTOPTS:
   3133 			newdest = &opt->ip6po_dest1;
   3134 			break;
   3135 		case IPV6_DSTOPTS:
   3136 			newdest = &opt->ip6po_dest2;
   3137 			break;
   3138 		}
   3139 
   3140 		/* turn off the previous option, then set the new option. */
   3141 		ip6_clearpktopts(opt, optname);
   3142 		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
   3143 		if (*newdest == NULL)
   3144 			return (ENOBUFS);
   3145 		memcpy(*newdest, dest, destlen);
   3146 
   3147 		break;
   3148 	}
   3149 
   3150 #ifdef RFC2292
   3151 	case IPV6_2292RTHDR:
   3152 #endif
   3153 	case IPV6_RTHDR:
   3154 	{
   3155 		struct ip6_rthdr *rth;
   3156 		int rthlen;
   3157 
   3158 		if (len == 0) {
   3159 			ip6_clearpktopts(opt, IPV6_RTHDR);
   3160 			break;	/* just remove the option */
   3161 		}
   3162 
   3163 		/* message length validation */
   3164 		if (len < sizeof(struct ip6_rthdr))
   3165 			return (EINVAL);
   3166 		rth = (struct ip6_rthdr *)buf;
   3167 		rthlen = (rth->ip6r_len + 1) << 3;
   3168 		if (len != rthlen)
   3169 			return (EINVAL);
   3170 		switch (rth->ip6r_type) {
   3171 		case IPV6_RTHDR_TYPE_0:
   3172 			if (rth->ip6r_len == 0)	/* must contain one addr */
   3173 				return (EINVAL);
   3174 			if (rth->ip6r_len % 2) /* length must be even */
   3175 				return (EINVAL);
   3176 			if (rth->ip6r_len / 2 != rth->ip6r_segleft)
   3177 				return (EINVAL);
   3178 			break;
   3179 		default:
   3180 			return (EINVAL);	/* not supported */
   3181 		}
   3182 		/* turn off the previous option */
   3183 		ip6_clearpktopts(opt, IPV6_RTHDR);
   3184 		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
   3185 		if (opt->ip6po_rthdr == NULL)
   3186 			return (ENOBUFS);
   3187 		memcpy(opt->ip6po_rthdr, rth, rthlen);
   3188 		break;
   3189 	}
   3190 
   3191 	case IPV6_USE_MIN_MTU:
   3192 		if (len != sizeof(int))
   3193 			return (EINVAL);
   3194 		minmtupolicy = *(int *)buf;
   3195 		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
   3196 		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
   3197 		    minmtupolicy != IP6PO_MINMTU_ALL) {
   3198 			return (EINVAL);
   3199 		}
   3200 		opt->ip6po_minmtu = minmtupolicy;
   3201 		break;
   3202 
   3203 	case IPV6_DONTFRAG:
   3204 		if (len != sizeof(int))
   3205 			return (EINVAL);
   3206 
   3207 		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
   3208 			/*
   3209 			 * we ignore this option for TCP sockets.
   3210 			 * (RFC3542 leaves this case unspecified.)
   3211 			 */
   3212 			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
   3213 		} else
   3214 			opt->ip6po_flags |= IP6PO_DONTFRAG;
   3215 		break;
   3216 
   3217 	default:
   3218 		return (ENOPROTOOPT);
   3219 	} /* end of switch */
   3220 
   3221 	return (0);
   3222 }
   3223 
   3224 /*
   3225  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
   3226  * packet to the input queue of a specified interface.  Note that this
   3227  * calls the output routine of the loopback "driver", but with an interface
   3228  * pointer that might NOT be lo0ifp -- easier than replicating that code here.
   3229  */
   3230 void
   3231 ip6_mloopback(struct ifnet *ifp, struct mbuf *m,
   3232 	const struct sockaddr_in6 *dst)
   3233 {
   3234 	struct mbuf *copym;
   3235 	struct ip6_hdr *ip6;
   3236 
   3237 	copym = m_copy(m, 0, M_COPYALL);
   3238 	if (copym == NULL)
   3239 		return;
   3240 
   3241 	/*
   3242 	 * Make sure to deep-copy IPv6 header portion in case the data
   3243 	 * is in an mbuf cluster, so that we can safely override the IPv6
   3244 	 * header portion later.
   3245 	 */
   3246 	if ((copym->m_flags & M_EXT) != 0 ||
   3247 	    copym->m_len < sizeof(struct ip6_hdr)) {
   3248 		copym = m_pullup(copym, sizeof(struct ip6_hdr));
   3249 		if (copym == NULL)
   3250 			return;
   3251 	}
   3252 
   3253 #ifdef DIAGNOSTIC
   3254 	if (copym->m_len < sizeof(*ip6)) {
   3255 		m_freem(copym);
   3256 		return;
   3257 	}
   3258 #endif
   3259 
   3260 	ip6 = mtod(copym, struct ip6_hdr *);
   3261 	/*
   3262 	 * clear embedded scope identifiers if necessary.
   3263 	 * in6_clearscope will touch the addresses only when necessary.
   3264 	 */
   3265 	in6_clearscope(&ip6->ip6_src);
   3266 	in6_clearscope(&ip6->ip6_dst);
   3267 
   3268 	(void)looutput(ifp, copym, (const struct sockaddr *)dst, NULL);
   3269 }
   3270 
   3271 /*
   3272  * Chop IPv6 header off from the payload.
   3273  */
   3274 static int
   3275 ip6_splithdr(struct mbuf *m,  struct ip6_exthdrs *exthdrs)
   3276 {
   3277 	struct mbuf *mh;
   3278 	struct ip6_hdr *ip6;
   3279 
   3280 	ip6 = mtod(m, struct ip6_hdr *);
   3281 	if (m->m_len > sizeof(*ip6)) {
   3282 		MGETHDR(mh, M_DONTWAIT, MT_HEADER);
   3283 		if (mh == 0) {
   3284 			m_freem(m);
   3285 			return ENOBUFS;
   3286 		}
   3287 		M_MOVE_PKTHDR(mh, m);
   3288 		MH_ALIGN(mh, sizeof(*ip6));
   3289 		m->m_len -= sizeof(*ip6);
   3290 		m->m_data += sizeof(*ip6);
   3291 		mh->m_next = m;
   3292 		m = mh;
   3293 		m->m_len = sizeof(*ip6);
   3294 		bcopy((void *)ip6, mtod(m, void *), sizeof(*ip6));
   3295 	}
   3296 	exthdrs->ip6e_ip6 = m;
   3297 	return 0;
   3298 }
   3299 
   3300 /*
   3301  * Compute IPv6 extension header length.
   3302  */
   3303 int
   3304 ip6_optlen(struct in6pcb *in6p)
   3305 {
   3306 	int len;
   3307 
   3308 	if (!in6p->in6p_outputopts)
   3309 		return 0;
   3310 
   3311 	len = 0;
   3312 #define elen(x) \
   3313     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
   3314 
   3315 	len += elen(in6p->in6p_outputopts->ip6po_hbh);
   3316 	len += elen(in6p->in6p_outputopts->ip6po_dest1);
   3317 	len += elen(in6p->in6p_outputopts->ip6po_rthdr);
   3318 	len += elen(in6p->in6p_outputopts->ip6po_dest2);
   3319 	return len;
   3320 #undef elen
   3321 }
   3322