sys/netinet6/ip6_output.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
  32  */
  33
  34 /*-
  35  * Copyright (c) 1982, 1986, 1988, 1990, 1993
  36  *      The Regents of the University of California.  All rights reserved.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  63  */
  64
  65 #include <sys/cdefs.h>
  66 __FBSDID("$FreeBSD$");
  67
  68 #include "opt_inet.h"
  69 #include "opt_inet6.h"
  70 #include "opt_ratelimit.h"
  71 #include "opt_ipsec.h"
  72 #include "opt_sctp.h"
  73 #include "opt_route.h"
  74 #include "opt_rss.h"
  75
  76 #include <sys/param.h>
  77 #include <sys/kernel.h>
  78 #include <sys/malloc.h>
  79 #include <sys/mbuf.h>
  80 #include <sys/errno.h>
  81 #include <sys/priv.h>
  82 #include <sys/proc.h>
  83 #include <sys/protosw.h>
  84 #include <sys/socket.h>
  85 #include <sys/socketvar.h>
  86 #include <sys/syslog.h>
  87 #include <sys/ucred.h>
  88
  89 #include <machine/in_cksum.h>
  90
  91 #include <net/if.h>
  92 #include <net/if_var.h>
  93 #include <net/if_llatbl.h>
  94 #include <net/netisr.h>
  95 #include <net/route.h>
  96 #include <net/pfil.h>
  97 #include <net/rss_config.h>
  98 #include <net/vnet.h>
  99
 100 #include <netinet/in.h>
 101 #include <netinet/in_var.h>
 102 #include <netinet/ip_var.h>
 103 #include <netinet6/in6_fib.h>
 104 #include <netinet6/in6_var.h>
 105 #include <netinet/ip6.h>
 106 #include <netinet/icmp6.h>
 107 #include <netinet6/ip6_var.h>
 108 #include <netinet/in_pcb.h>
 109 #include <netinet/tcp_var.h>
 110 #include <netinet6/nd6.h>
 111 #include <netinet6/in6_rss.h>
 112
 113 #include <netipsec/ipsec_support.h>
 114 #ifdef SCTP
 115 #include <netinet/sctp.h>
 116 #include <netinet/sctp_crc32.h>
 117 #endif
 118
 119 #include <netinet6/ip6protosw.h>
 120 #include <netinet6/scope6_var.h>
 121
 122 extern int in6_mcast_loop;
 123
 124 struct ip6_exthdrs {
 125         struct mbuf *ip6e_ip6;
 126         struct mbuf *ip6e_hbh;
 127         struct mbuf *ip6e_dest1;
 128         struct mbuf *ip6e_rthdr;
 129         struct mbuf *ip6e_dest2;
 130 };
 131
 132 static MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
 133
 134 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
 135                            struct ucred *, int);
 136 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
 137         struct socket *, struct sockopt *);
 138 static int ip6_getpcbopt(struct inpcb *, int, struct sockopt *);
 139 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
 140         struct ucred *, int, int, int);
 141
 142 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 143 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
 144         struct ip6_frag **);
 145 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 146 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 147 static int ip6_getpmtu(struct route_in6 *, int,
 148         struct ifnet *, const struct in6_addr *, u_long *, int *, u_int,
 149         u_int);
 150 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
 151         u_long *, int *, u_int);
 152 static int ip6_getpmtu_ctl(u_int, const struct in6_addr *, u_long *);
 153 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 154
 155
 156 /*
 157  * Make an extension header from option data.  hp is the source, and
 158  * mp is the destination.
 159  */
 160 #define MAKE_EXTHDR(hp, mp)                                             \
 161     do {                                                                \
 162         if (hp) {                                                       \
 163                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 164                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 165                     ((eh)->ip6e_len + 1) << 3);                         \
 166                 if (error)                                              \
 167                         goto freehdrs;                                  \
 168         }                                                               \
 169     } while (/*CONSTCOND*/ 0)
 170
 171 /*
 172  * Form a chain of extension headers.
 173  * m is the extension header mbuf
 174  * mp is the previous mbuf in the chain
 175  * p is the next header
 176  * i is the type of option.
 177  */
 178 #define MAKE_CHAIN(m, mp, p, i)\
 179     do {\
 180         if (m) {\
 181                 if (!hdrsplit) \
 182                         panic("assumption failed: hdr not split"); \
 183                 *mtod((m), u_char *) = *(p);\
 184                 *(p) = (i);\
 185                 p = mtod((m), u_char *);\
 186                 (m)->m_next = (mp)->m_next;\
 187                 (mp)->m_next = (m);\
 188                 (mp) = (m);\
 189         }\
 190     } while (/*CONSTCOND*/ 0)
 191
 192 void
 193 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
 194 {
 195         u_short csum;
 196
 197         csum = in_cksum_skip(m, offset + plen, offset);
 198         if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
 199                 csum = 0xffff;
 200         offset += m->m_pkthdr.csum_data;        /* checksum offset */
 201
 202         if (offset + sizeof(csum) > m->m_len)
 203                 m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
 204         else
 205                 *(u_short *)mtodo(m, offset) = csum;
 206 }
 207
 208 int
 209 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
 210     int fraglen , uint32_t id)
 211 {
 212         struct mbuf *m, **mnext, *m_frgpart;
 213         struct ip6_hdr *ip6, *mhip6;
 214         struct ip6_frag *ip6f;
 215         int off;
 216         int error;
 217         int tlen = m0->m_pkthdr.len;
 218
 219         KASSERT((fraglen % 8 == 0), ("Fragment length must be a multiple of 8"));
 220
 221         m = m0;
 222         ip6 = mtod(m, struct ip6_hdr *);
 223         mnext = &m->m_nextpkt;
 224
 225         for (off = hlen; off < tlen; off += fraglen) {
 226                 m = m_gethdr(M_NOWAIT, MT_DATA);
 227                 if (!m) {
 228                         IP6STAT_INC(ip6s_odropped);
 229                         return (ENOBUFS);
 230                 }
 231                 m->m_flags = m0->m_flags & M_COPYFLAGS;
 232                 *mnext = m;
 233                 mnext = &m->m_nextpkt;
 234                 m->m_data += max_linkhdr;
 235                 mhip6 = mtod(m, struct ip6_hdr *);
 236                 *mhip6 = *ip6;
 237                 m->m_len = sizeof(*mhip6);
 238                 error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
 239                 if (error) {
 240                         IP6STAT_INC(ip6s_odropped);
 241                         return (error);
 242                 }
 243                 ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
 244                 if (off + fraglen >= tlen)
 245                         fraglen = tlen - off;
 246                 else
 247                         ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
 248                 mhip6->ip6_plen = htons((u_short)(fraglen + hlen +
 249                     sizeof(*ip6f) - sizeof(struct ip6_hdr)));
 250                 if ((m_frgpart = m_copym(m0, off, fraglen, M_NOWAIT)) == NULL) {
 251                         IP6STAT_INC(ip6s_odropped);
 252                         return (ENOBUFS);
 253                 }
 254                 m_cat(m, m_frgpart);
 255                 m->m_pkthdr.len = fraglen + hlen + sizeof(*ip6f);
 256                 m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
 257                 m->m_pkthdr.rcvif = NULL;
 258                 ip6f->ip6f_reserved = 0;
 259                 ip6f->ip6f_ident = id;
 260                 ip6f->ip6f_nxt = nextproto;
 261                 IP6STAT_INC(ip6s_ofragments);
 262                 in6_ifstat_inc(ifp, ifs6_out_fragcreat);
 263         }
 264
 265         return (0);
 266 }
 267
 268 /*
 269  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 270  * header (with pri, len, nxt, hlim, src, dst).
 271  * This function may modify ver and hlim only.
 272  * The mbuf chain containing the packet will be freed.
 273  * The mbuf opt, if present, will not be freed.
 274  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
 275  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
 276  * then result of route lookup is stored in ro->ro_rt.
 277  *
 278  * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
 279  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 280  * which is rt_mtu.
 281  *
 282  * ifpp - XXX: just for statistics
 283  */
 284 /*
 285  * XXX TODO: no flowid is assigned for outbound flows?
 286  */
 287 int
 288 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 289     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 290     struct ifnet **ifpp, struct inpcb *inp)
 291 {
 292         struct ip6_hdr *ip6;
 293         struct ifnet *ifp, *origifp;
 294         struct mbuf *m = m0;
 295         struct mbuf *mprev = NULL;
 296         int hlen, tlen, len;
 297         struct route_in6 ip6route;
 298         struct rtentry *rt = NULL;
 299         struct sockaddr_in6 *dst, src_sa, dst_sa;
 300         struct in6_addr odst;
 301         int error = 0;
 302         struct in6_ifaddr *ia = NULL;
 303         u_long mtu;
 304         int alwaysfrag, dontfrag;
 305         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 306         struct ip6_exthdrs exthdrs;
 307         struct in6_addr src0, dst0;
 308         u_int32_t zone;
 309         struct route_in6 *ro_pmtu = NULL;
 310         int hdrsplit = 0;
 311         int sw_csum, tso;
 312         int needfiblookup;
 313         uint32_t fibnum;
 314         struct m_tag *fwd_tag = NULL;
 315         uint32_t id;
 316
 317         if (inp != NULL) {
 318                 INP_LOCK_ASSERT(inp);
 319                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
 320                 if ((flags & IP_NODEFAULTFLOWID) == 0) {
 321                         /* unconditionally set flowid */
 322                         m->m_pkthdr.flowid = inp->inp_flowid;
 323                         M_HASHTYPE_SET(m, inp->inp_flowtype);
 324                 }
 325         }
 326
 327 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 328         /*
 329          * IPSec checking which handles several cases.
 330          * FAST IPSEC: We re-injected the packet.
 331          * XXX: need scope argument.
 332          */
 333         if (IPSEC_ENABLED(ipv6)) {
 334                 if ((error = IPSEC_OUTPUT(ipv6, m, inp)) != 0) {
 335                         if (error == EINPROGRESS)
 336                                 error = 0;
 337                         goto done;
 338                 }
 339         }
 340 #endif /* IPSEC */
 341
 342         bzero(&exthdrs, sizeof(exthdrs));
 343         if (opt) {
 344                 /* Hop-by-Hop options header */
 345                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 346                 /* Destination options header(1st part) */
 347                 if (opt->ip6po_rthdr) {
 348                         /*
 349                          * Destination options header(1st part)
 350                          * This only makes sense with a routing header.
 351                          * See Section 9.2 of RFC 3542.
 352                          * Disabling this part just for MIP6 convenience is
 353                          * a bad idea.  We need to think carefully about a
 354                          * way to make the advanced API coexist with MIP6
 355                          * options, which might automatically be inserted in
 356                          * the kernel.
 357                          */
 358                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 359                 }
 360                 /* Routing header */
 361                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 362                 /* Destination options header(2nd part) */
 363                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 364         }
 365
 366         /*
 367          * Calculate the total length of the extension header chain.
 368          * Keep the length of the unfragmentable part for fragmentation.
 369          */
 370         optlen = 0;
 371         if (exthdrs.ip6e_hbh)
 372                 optlen += exthdrs.ip6e_hbh->m_len;
 373         if (exthdrs.ip6e_dest1)
 374                 optlen += exthdrs.ip6e_dest1->m_len;
 375         if (exthdrs.ip6e_rthdr)
 376                 optlen += exthdrs.ip6e_rthdr->m_len;
 377         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 378
 379         /* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
 380         if (exthdrs.ip6e_dest2)
 381                 optlen += exthdrs.ip6e_dest2->m_len;
 382
 383         /*
 384          * If there is at least one extension header,
 385          * separate IP6 header from the payload.
 386          */
 387         if (optlen && !hdrsplit) {
 388                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 389                         m = NULL;
 390                         goto freehdrs;
 391                 }
 392                 m = exthdrs.ip6e_ip6;
 393                 hdrsplit++;
 394         }
 395
 396         ip6 = mtod(m, struct ip6_hdr *);
 397
 398         /* adjust mbuf packet header length */
 399         m->m_pkthdr.len += optlen;
 400         plen = m->m_pkthdr.len - sizeof(*ip6);
 401
 402         /* If this is a jumbo payload, insert a jumbo payload option. */
 403         if (plen > IPV6_MAXPACKET) {
 404                 if (!hdrsplit) {
 405                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 406                                 m = NULL;
 407                                 goto freehdrs;
 408                         }
 409                         m = exthdrs.ip6e_ip6;
 410                         hdrsplit++;
 411                 }
 412                 /* adjust pointer */
 413                 ip6 = mtod(m, struct ip6_hdr *);
 414                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 415                         goto freehdrs;
 416                 ip6->ip6_plen = 0;
 417         } else
 418                 ip6->ip6_plen = htons(plen);
 419
 420         /*
 421          * Concatenate headers and fill in next header fields.
 422          * Here we have, on "m"
 423          *      IPv6 payload
 424          * and we insert headers accordingly.  Finally, we should be getting:
 425          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 426          *
 427          * during the header composing process, "m" points to IPv6 header.
 428          * "mprev" points to an extension header prior to esp.
 429          */
 430         u_char *nexthdrp = &ip6->ip6_nxt;
 431         mprev = m;
 432
 433         /*
 434          * we treat dest2 specially.  this makes IPsec processing
 435          * much easier.  the goal here is to make mprev point the
 436          * mbuf prior to dest2.
 437          *
 438          * result: IPv6 dest2 payload
 439          * m and mprev will point to IPv6 header.
 440          */
 441         if (exthdrs.ip6e_dest2) {
 442                 if (!hdrsplit)
 443                         panic("assumption failed: hdr not split");
 444                 exthdrs.ip6e_dest2->m_next = m->m_next;
 445                 m->m_next = exthdrs.ip6e_dest2;
 446                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 447                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 448         }
 449
 450         /*
 451          * result: IPv6 hbh dest1 rthdr dest2 payload
 452          * m will point to IPv6 header.  mprev will point to the
 453          * extension header prior to dest2 (rthdr in the above case).
 454          */
 455         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 456         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 457                    IPPROTO_DSTOPTS);
 458         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 459                    IPPROTO_ROUTING);
 460
 461         /*
 462          * If there is a routing header, discard the packet.
 463          */
 464         if (exthdrs.ip6e_rthdr) {
 465                  error = EINVAL;
 466                  goto bad;
 467         }
 468
 469         /* Source address validation */
 470         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 471             (flags & IPV6_UNSPECSRC) == 0) {
 472                 error = EOPNOTSUPP;
 473                 IP6STAT_INC(ip6s_badscope);
 474                 goto bad;
 475         }
 476         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 477                 error = EOPNOTSUPP;
 478                 IP6STAT_INC(ip6s_badscope);
 479                 goto bad;
 480         }
 481
 482         IP6STAT_INC(ip6s_localout);
 483
 484         /*
 485          * Route packet.
 486          */
 487         if (ro == NULL) {
 488                 ro = &ip6route;
 489                 bzero((caddr_t)ro, sizeof(*ro));
 490         }
 491         ro_pmtu = ro;
 492         if (opt && opt->ip6po_rthdr)
 493                 ro = &opt->ip6po_route;
 494         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 495         fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
 496 again:
 497         /*
 498          * if specified, try to fill in the traffic class field.
 499          * do not override if a non-zero value is already set.
 500          * we check the diffserv field and the ecn field separately.
 501          */
 502         if (opt && opt->ip6po_tclass >= 0) {
 503                 int mask = 0;
 504
 505                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 506                         mask |= 0xfc;
 507                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 508                         mask |= 0x03;
 509                 if (mask != 0)
 510                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 511         }
 512
 513         /* fill in or override the hop limit field, if necessary. */
 514         if (opt && opt->ip6po_hlim != -1)
 515                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 516         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 517                 if (im6o != NULL)
 518                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 519                 else
 520                         ip6->ip6_hlim = V_ip6_defmcasthlim;
 521         }
 522         /*
 523          * Validate route against routing table additions;
 524          * a better/more specific route might have been added.
 525          * Make sure address family is set in route.
 526          */
 527         if (inp) {
 528                 ro->ro_dst.sin6_family = AF_INET6;
 529                 RT_VALIDATE((struct route *)ro, &inp->inp_rt_cookie, fibnum);
 530         }
 531         if (ro->ro_rt && fwd_tag == NULL && (ro->ro_rt->rt_flags & RTF_UP) &&
 532             ro->ro_dst.sin6_family == AF_INET6 &&
 533             IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)) {
 534                 rt = ro->ro_rt;
 535                 ifp = ro->ro_rt->rt_ifp;
 536         } else {
 537                 if (ro->ro_lle)
 538                         LLE_FREE(ro->ro_lle);   /* zeros ro_lle */
 539                 ro->ro_lle = NULL;
 540                 if (fwd_tag == NULL) {
 541                         bzero(&dst_sa, sizeof(dst_sa));
 542                         dst_sa.sin6_family = AF_INET6;
 543                         dst_sa.sin6_len = sizeof(dst_sa);
 544                         dst_sa.sin6_addr = ip6->ip6_dst;
 545                 }
 546                 error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
 547                     &rt, fibnum);
 548                 if (error != 0) {
 549                         if (ifp != NULL)
 550                                 in6_ifstat_inc(ifp, ifs6_out_discard);
 551                         goto bad;
 552                 }
 553         }
 554         if (rt == NULL) {
 555                 /*
 556                  * If in6_selectroute() does not return a route entry,
 557                  * dst may not have been updated.
 558                  */
 559                 *dst = dst_sa;  /* XXX */
 560         }
 561
 562         /*
 563          * then rt (for unicast) and ifp must be non-NULL valid values.
 564          */
 565         if ((flags & IPV6_FORWARDING) == 0) {
 566                 /* XXX: the FORWARDING flag can be set for mrouting. */
 567                 in6_ifstat_inc(ifp, ifs6_out_request);
 568         }
 569         if (rt != NULL) {
 570                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 571                 counter_u64_add(rt->rt_pksent, 1);
 572         }
 573
 574         /* Setup data structures for scope ID checks. */
 575         src0 = ip6->ip6_src;
 576         bzero(&src_sa, sizeof(src_sa));
 577         src_sa.sin6_family = AF_INET6;
 578         src_sa.sin6_len = sizeof(src_sa);
 579         src_sa.sin6_addr = ip6->ip6_src;
 580
 581         dst0 = ip6->ip6_dst;
 582         /* re-initialize to be sure */
 583         bzero(&dst_sa, sizeof(dst_sa));
 584         dst_sa.sin6_family = AF_INET6;
 585         dst_sa.sin6_len = sizeof(dst_sa);
 586         dst_sa.sin6_addr = ip6->ip6_dst;
 587
 588         /* Check for valid scope ID. */
 589         if (in6_setscope(&src0, ifp, &zone) == 0 &&
 590             sa6_recoverscope(&src_sa) == 0 && zone == src_sa.sin6_scope_id &&
 591             in6_setscope(&dst0, ifp, &zone) == 0 &&
 592             sa6_recoverscope(&dst_sa) == 0 && zone == dst_sa.sin6_scope_id) {
 593                 /*
 594                  * The outgoing interface is in the zone of the source
 595                  * and destination addresses.
 596                  *
 597                  * Because the loopback interface cannot receive
 598                  * packets with a different scope ID than its own,
 599                  * there is a trick is to pretend the outgoing packet
 600                  * was received by the real network interface, by
 601                  * setting "origifp" different from "ifp". This is
 602                  * only allowed when "ifp" is a loopback network
 603                  * interface. Refer to code in nd6_output_ifp() for
 604                  * more details.
 605                  */
 606                 origifp = ifp;
 607
 608                 /*
 609                  * We should use ia_ifp to support the case of sending
 610                  * packets to an address of our own.
 611                  */
 612                 if (ia != NULL && ia->ia_ifp)
 613                         ifp = ia->ia_ifp;
 614
 615         } else if ((ifp->if_flags & IFF_LOOPBACK) == 0 ||
 616             sa6_recoverscope(&src_sa) != 0 ||
 617             sa6_recoverscope(&dst_sa) != 0 ||
 618             dst_sa.sin6_scope_id == 0 ||
 619             (src_sa.sin6_scope_id != 0 &&
 620             src_sa.sin6_scope_id != dst_sa.sin6_scope_id) ||
 621             (origifp = ifnet_byindex(dst_sa.sin6_scope_id)) == NULL) {
 622                 /*
 623                  * If the destination network interface is not a
 624                  * loopback interface, or the destination network
 625                  * address has no scope ID, or the source address has
 626                  * a scope ID set which is different from the
 627                  * destination address one, or there is no network
 628                  * interface representing this scope ID, the address
 629                  * pair is considered invalid.
 630                  */
 631                 IP6STAT_INC(ip6s_badscope);
 632                 in6_ifstat_inc(ifp, ifs6_out_discard);
 633                 if (error == 0)
 634                         error = EHOSTUNREACH; /* XXX */
 635                 goto bad;
 636         }
 637
 638         /* All scope ID checks are successful. */
 639
 640         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 641                 if (opt && opt->ip6po_nextroute.ro_rt) {
 642                         /*
 643                          * The nexthop is explicitly specified by the
 644                          * application.  We assume the next hop is an IPv6
 645                          * address.
 646                          */
 647                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 648                 }
 649                 else if ((rt->rt_flags & RTF_GATEWAY))
 650                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 651         }
 652
 653         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 654                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 655         } else {
 656                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 657                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 658                 /*
 659                  * Confirm that the outgoing interface supports multicast.
 660                  */
 661                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 662                         IP6STAT_INC(ip6s_noroute);
 663                         in6_ifstat_inc(ifp, ifs6_out_discard);
 664                         error = ENETUNREACH;
 665                         goto bad;
 666                 }
 667                 if ((im6o == NULL && in6_mcast_loop) ||
 668                     (im6o && im6o->im6o_multicast_loop)) {
 669                         /*
 670                          * Loop back multicast datagram if not expressly
 671                          * forbidden to do so, even if we have not joined
 672                          * the address; protocols will filter it later,
 673                          * thus deferring a hash lookup and lock acquisition
 674                          * at the expense of an m_copym().
 675                          */
 676                         ip6_mloopback(ifp, m);
 677                 } else {
 678                         /*
 679                          * If we are acting as a multicast router, perform
 680                          * multicast forwarding as if the packet had just
 681                          * arrived on the interface to which we are about
 682                          * to send.  The multicast forwarding function
 683                          * recursively calls this function, using the
 684                          * IPV6_FORWARDING flag to prevent infinite recursion.
 685                          *
 686                          * Multicasts that are looped back by ip6_mloopback(),
 687                          * above, will be forwarded by the ip6_input() routine,
 688                          * if necessary.
 689                          */
 690                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 691                                 /*
 692                                  * XXX: ip6_mforward expects that rcvif is NULL
 693                                  * when it is called from the originating path.
 694                                  * However, it may not always be the case.
 695                                  */
 696                                 m->m_pkthdr.rcvif = NULL;
 697                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 698                                         m_freem(m);
 699                                         goto done;
 700                                 }
 701                         }
 702                 }
 703                 /*
 704                  * Multicasts with a hoplimit of zero may be looped back,
 705                  * above, but must not be transmitted on a network.
 706                  * Also, multicasts addressed to the loopback interface
 707                  * are not sent -- the above call to ip6_mloopback() will
 708                  * loop back a copy if this host actually belongs to the
 709                  * destination group on the loopback interface.
 710                  */
 711                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 712                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 713                         m_freem(m);
 714                         goto done;
 715                 }
 716         }
 717
 718         /*
 719          * Fill the outgoing inteface to tell the upper layer
 720          * to increment per-interface statistics.
 721          */
 722         if (ifpp)
 723                 *ifpp = ifp;
 724
 725         /* Determine path MTU. */
 726         if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &ip6->ip6_dst,
 727                     &mtu, &alwaysfrag, fibnum, *nexthdrp)) != 0)
 728                 goto bad;
 729
 730         /*
 731          * The caller of this function may specify to use the minimum MTU
 732          * in some cases.
 733          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 734          * setting.  The logic is a bit complicated; by default, unicast
 735          * packets will follow path MTU while multicast packets will be sent at
 736          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 737          * including unicast ones will be sent at the minimum MTU.  Multicast
 738          * packets will always be sent at the minimum MTU unless
 739          * IP6PO_MINMTU_DISABLE is explicitly specified.
 740          * See RFC 3542 for more details.
 741          */
 742         if (mtu > IPV6_MMTU) {
 743                 if ((flags & IPV6_MINMTU))
 744                         mtu = IPV6_MMTU;
 745                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 746                         mtu = IPV6_MMTU;
 747                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 748                          (opt == NULL ||
 749                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 750                         mtu = IPV6_MMTU;
 751                 }
 752         }
 753
 754         /*
 755          * clear embedded scope identifiers if necessary.
 756          * in6_clearscope will touch the addresses only when necessary.
 757          */
 758         in6_clearscope(&ip6->ip6_src);
 759         in6_clearscope(&ip6->ip6_dst);
 760
 761         /*
 762          * If the outgoing packet contains a hop-by-hop options header,
 763          * it must be examined and processed even by the source node.
 764          * (RFC 2460, section 4.)
 765          */
 766         if (exthdrs.ip6e_hbh) {
 767                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 768                 u_int32_t dummy; /* XXX unused */
 769                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 770
 771 #ifdef DIAGNOSTIC
 772                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 773                         panic("ip6e_hbh is not contiguous");
 774 #endif
 775                 /*
 776                  *  XXX: if we have to send an ICMPv6 error to the sender,
 777                  *       we need the M_LOOP flag since icmp6_error() expects
 778                  *       the IPv6 and the hop-by-hop options header are
 779                  *       contiguous unless the flag is set.
 780                  */
 781                 m->m_flags |= M_LOOP;
 782                 m->m_pkthdr.rcvif = ifp;
 783                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 784                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 785                     &dummy, &plen) < 0) {
 786                         /* m was already freed at this point */
 787                         error = EINVAL;/* better error? */
 788                         goto done;
 789                 }
 790                 m->m_flags &= ~M_LOOP; /* XXX */
 791                 m->m_pkthdr.rcvif = NULL;
 792         }
 793
 794         /* Jump over all PFIL processing if hooks are not active. */
 795         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
 796                 goto passout;
 797
 798         odst = ip6->ip6_dst;
 799         /* Run through list of hooks for output packets. */
 800         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, 0, inp);
 801         if (error != 0 || m == NULL)
 802                 goto done;
 803         /* adjust pointer */
 804         ip6 = mtod(m, struct ip6_hdr *);
 805
 806         needfiblookup = 0;
 807         /* See if destination IP address was changed by packet filter. */
 808         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 809                 m->m_flags |= M_SKIP_FIREWALL;
 810                 /* If destination is now ourself drop to ip6_input(). */
 811                 if (in6_localip(&ip6->ip6_dst)) {
 812                         m->m_flags |= M_FASTFWD_OURS;
 813                         if (m->m_pkthdr.rcvif == NULL)
 814                                 m->m_pkthdr.rcvif = V_loif;
 815                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 816                                 m->m_pkthdr.csum_flags |=
 817                                     CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 818                                 m->m_pkthdr.csum_data = 0xffff;
 819                         }
 820 #ifdef SCTP
 821                         if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 822                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 823 #endif
 824                         error = netisr_queue(NETISR_IPV6, m);
 825                         goto done;
 826                 } else {
 827                         RO_INVALIDATE_CACHE(ro);
 828                         needfiblookup = 1; /* Redo the routing table lookup. */
 829                 }
 830         }
 831         /* See if fib was changed by packet filter. */
 832         if (fibnum != M_GETFIB(m)) {
 833                 m->m_flags |= M_SKIP_FIREWALL;
 834                 fibnum = M_GETFIB(m);
 835                 RO_INVALIDATE_CACHE(ro);
 836                 needfiblookup = 1;
 837         }
 838         if (needfiblookup)
 839                 goto again;
 840
 841         /* See if local, if yes, send it to netisr. */
 842         if (m->m_flags & M_FASTFWD_OURS) {
 843                 if (m->m_pkthdr.rcvif == NULL)
 844                         m->m_pkthdr.rcvif = V_loif;
 845                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 846                         m->m_pkthdr.csum_flags |=
 847                             CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 848                         m->m_pkthdr.csum_data = 0xffff;
 849                 }
 850 #ifdef SCTP
 851                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 852                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 853 #endif
 854                 error = netisr_queue(NETISR_IPV6, m);
 855                 goto done;
 856         }
 857         /* Or forward to some other address? */
 858         if ((m->m_flags & M_IP6_NEXTHOP) &&
 859             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 860                 dst = (struct sockaddr_in6 *)&ro->ro_dst;
 861                 bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
 862                 m->m_flags |= M_SKIP_FIREWALL;
 863                 m->m_flags &= ~M_IP6_NEXTHOP;
 864                 m_tag_delete(m, fwd_tag);
 865                 goto again;
 866         }
 867
 868 passout:
 869         /*
 870          * Send the packet to the outgoing interface.
 871          * If necessary, do IPv6 fragmentation before sending.
 872          *
 873          * the logic here is rather complex:
 874          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 875          * 1-a: send as is if tlen <= path mtu
 876          * 1-b: fragment if tlen > path mtu
 877          *
 878          * 2: if user asks us not to fragment (dontfrag == 1)
 879          * 2-a: send as is if tlen <= interface mtu
 880          * 2-b: error if tlen > interface mtu
 881          *
 882          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 883          *      always fragment
 884          *
 885          * 4: if dontfrag == 1 && alwaysfrag == 1
 886          *      error, as we cannot handle this conflicting request
 887          */
 888         sw_csum = m->m_pkthdr.csum_flags;
 889         if (!hdrsplit) {
 890                 tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
 891                 sw_csum &= ~ifp->if_hwassist;
 892         } else
 893                 tso = 0;
 894         /*
 895          * If we added extension headers, we will not do TSO and calculate the
 896          * checksums ourselves for now.
 897          * XXX-BZ  Need a framework to know when the NIC can handle it, even
 898          * with ext. hdrs.
 899          */
 900         if (sw_csum & CSUM_DELAY_DATA_IPV6) {
 901                 sw_csum &= ~CSUM_DELAY_DATA_IPV6;
 902                 in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
 903         }
 904 #ifdef SCTP
 905         if (sw_csum & CSUM_SCTP_IPV6) {
 906                 sw_csum &= ~CSUM_SCTP_IPV6;
 907                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 908         }
 909 #endif
 910         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
 911         tlen = m->m_pkthdr.len;
 912
 913         if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
 914                 dontfrag = 1;
 915         else
 916                 dontfrag = 0;
 917         if (dontfrag && alwaysfrag) {   /* case 4 */
 918                 /* conflicting request - can't transmit */
 919                 error = EMSGSIZE;
 920                 goto bad;
 921         }
 922         if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {      /* case 2-b */
 923                 /*
 924                  * Even if the DONTFRAG option is specified, we cannot send the
 925                  * packet when the data length is larger than the MTU of the
 926                  * outgoing interface.
 927                  * Notify the error by sending IPV6_PATHMTU ancillary data if
 928                  * application wanted to know the MTU value. Also return an
 929                  * error code (this is not described in the API spec).
 930                  */
 931                 if (inp != NULL)
 932                         ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
 933                 error = EMSGSIZE;
 934                 goto bad;
 935         }
 936
 937         /*
 938          * transmit packet without fragmentation
 939          */
 940         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 941                 struct in6_ifaddr *ia6;
 942
 943                 ip6 = mtod(m, struct ip6_hdr *);
 944                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 945                 if (ia6) {
 946                         /* Record statistics for this interface address. */
 947                         counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
 948                         counter_u64_add(ia6->ia_ifa.ifa_obytes,
 949                             m->m_pkthdr.len);
 950                         ifa_free(&ia6->ia_ifa);
 951                 }
 952 #ifdef RATELIMIT
 953                 if (inp != NULL) {
 954                         if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
 955                                 in_pcboutput_txrtlmt(inp, ifp, m);
 956                         /* stamp send tag on mbuf */
 957                         m->m_pkthdr.snd_tag = inp->inp_snd_tag;
 958                 } else {
 959                         m->m_pkthdr.snd_tag = NULL;
 960                 }
 961 #endif
 962                 error = nd6_output_ifp(ifp, origifp, m, dst,
 963                     (struct route *)ro);
 964 #ifdef RATELIMIT
 965                 /* check for route change */
 966                 if (error == EAGAIN)
 967                         in_pcboutput_eagain(inp);
 968 #endif
 969                 goto done;
 970         }
 971
 972         /*
 973          * try to fragment the packet.  case 1-b and 3
 974          */
 975         if (mtu < IPV6_MMTU) {
 976                 /* path MTU cannot be less than IPV6_MMTU */
 977                 error = EMSGSIZE;
 978                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 979                 goto bad;
 980         } else if (ip6->ip6_plen == 0) {
 981                 /* jumbo payload cannot be fragmented */
 982                 error = EMSGSIZE;
 983                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 984                 goto bad;
 985         } else {
 986                 u_char nextproto;
 987
 988                 /*
 989                  * Too large for the destination or interface;
 990                  * fragment if possible.
 991                  * Must be able to put at least 8 bytes per fragment.
 992                  */
 993                 hlen = unfragpartlen;
 994                 if (mtu > IPV6_MAXPACKET)
 995                         mtu = IPV6_MAXPACKET;
 996
 997                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 998                 if (len < 8) {
 999                         error = EMSGSIZE;
1000                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
1001                         goto bad;
1002                 }
1003
1004                 /*
1005                  * If the interface will not calculate checksums on
1006                  * fragmented packets, then do it here.
1007                  * XXX-BZ handle the hw offloading case.  Need flags.
1008                  */
1009                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1010                         in6_delayed_cksum(m, plen, hlen);
1011                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
1012                 }
1013 #ifdef SCTP
1014                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
1015                         sctp_delayed_cksum(m, hlen);
1016                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
1017                 }
1018 #endif
1019                 /*
1020                  * Change the next header field of the last header in the
1021                  * unfragmentable part.
1022                  */
1023                 if (exthdrs.ip6e_rthdr) {
1024                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1025                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1026                 } else if (exthdrs.ip6e_dest1) {
1027                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1028                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1029                 } else if (exthdrs.ip6e_hbh) {
1030                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1031                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1032                 } else {
1033                         nextproto = ip6->ip6_nxt;
1034                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
1035                 }
1036
1037                 /*
1038                  * Loop through length of segment after first fragment,
1039                  * make new header and copy data of each part and link onto
1040                  * chain.
1041                  */
1042                 m0 = m;
1043                 id = htonl(ip6_randomid());
1044                 if ((error = ip6_fragment(ifp, m, hlen, nextproto, len, id)))
1045                         goto sendorfree;
1046
1047                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1048         }
1049
1050         /*
1051          * Remove leading garbages.
1052          */
1053 sendorfree:
1054         m = m0->m_nextpkt;
1055         m0->m_nextpkt = 0;
1056         m_freem(m0);
1057         for (; m; m = m0) {
1058                 m0 = m->m_nextpkt;
1059                 m->m_nextpkt = 0;
1060                 if (error == 0) {
1061                         /* Record statistics for this interface address. */
1062                         if (ia) {
1063                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1064                                 counter_u64_add(ia->ia_ifa.ifa_obytes,
1065                                     m->m_pkthdr.len);
1066                         }
1067 #ifdef RATELIMIT
1068                         if (inp != NULL) {
1069                                 if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
1070                                         in_pcboutput_txrtlmt(inp, ifp, m);
1071                                 /* stamp send tag on mbuf */
1072                                 m->m_pkthdr.snd_tag = inp->inp_snd_tag;
1073                         } else {
1074                                 m->m_pkthdr.snd_tag = NULL;
1075                         }
1076 #endif
1077                         error = nd6_output_ifp(ifp, origifp, m, dst,
1078                             (struct route *)ro);
1079 #ifdef RATELIMIT
1080                         /* check for route change */
1081                         if (error == EAGAIN)
1082                                 in_pcboutput_eagain(inp);
1083 #endif
1084                 } else
1085                         m_freem(m);
1086         }
1087
1088         if (error == 0)
1089                 IP6STAT_INC(ip6s_fragmented);
1090
1091 done:
1092         if (ro == &ip6route)
1093                 RO_RTFREE(ro);
1094         return (error);
1095
1096 freehdrs:
1097         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1098         m_freem(exthdrs.ip6e_dest1);
1099         m_freem(exthdrs.ip6e_rthdr);
1100         m_freem(exthdrs.ip6e_dest2);
1101         /* FALLTHROUGH */
1102 bad:
1103         if (m)
1104                 m_freem(m);
1105         goto done;
1106 }
1107
1108 static int
1109 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1110 {
1111         struct mbuf *m;
1112
1113         if (hlen > MCLBYTES)
1114                 return (ENOBUFS); /* XXX */
1115
1116         if (hlen > MLEN)
1117                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1118         else
1119                 m = m_get(M_NOWAIT, MT_DATA);
1120         if (m == NULL)
1121                 return (ENOBUFS);
1122         m->m_len = hlen;
1123         if (hdr)
1124                 bcopy(hdr, mtod(m, caddr_t), hlen);
1125
1126         *mp = m;
1127         return (0);
1128 }
1129
1130 /*
1131  * Insert jumbo payload option.
1132  */
1133 static int
1134 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1135 {
1136         struct mbuf *mopt;
1137         u_char *optbuf;
1138         u_int32_t v;
1139
1140 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1141
1142         /*
1143          * If there is no hop-by-hop options header, allocate new one.
1144          * If there is one but it doesn't have enough space to store the
1145          * jumbo payload option, allocate a cluster to store the whole options.
1146          * Otherwise, use it to store the options.
1147          */
1148         if (exthdrs->ip6e_hbh == NULL) {
1149                 mopt = m_get(M_NOWAIT, MT_DATA);
1150                 if (mopt == NULL)
1151                         return (ENOBUFS);
1152                 mopt->m_len = JUMBOOPTLEN;
1153                 optbuf = mtod(mopt, u_char *);
1154                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1155                 exthdrs->ip6e_hbh = mopt;
1156         } else {
1157                 struct ip6_hbh *hbh;
1158
1159                 mopt = exthdrs->ip6e_hbh;
1160                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1161                         /*
1162                          * XXX assumption:
1163                          * - exthdrs->ip6e_hbh is not referenced from places
1164                          *   other than exthdrs.
1165                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1166                          */
1167                         int oldoptlen = mopt->m_len;
1168                         struct mbuf *n;
1169
1170                         /*
1171                          * XXX: give up if the whole (new) hbh header does
1172                          * not fit even in an mbuf cluster.
1173                          */
1174                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1175                                 return (ENOBUFS);
1176
1177                         /*
1178                          * As a consequence, we must always prepare a cluster
1179                          * at this point.
1180                          */
1181                         n = m_getcl(M_NOWAIT, MT_DATA, 0);
1182                         if (n == NULL)
1183                                 return (ENOBUFS);
1184                         n->m_len = oldoptlen + JUMBOOPTLEN;
1185                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1186                             oldoptlen);
1187                         optbuf = mtod(n, caddr_t) + oldoptlen;
1188                         m_freem(mopt);
1189                         mopt = exthdrs->ip6e_hbh = n;
1190                 } else {
1191                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1192                         mopt->m_len += JUMBOOPTLEN;
1193                 }
1194                 optbuf[0] = IP6OPT_PADN;
1195                 optbuf[1] = 1;
1196
1197                 /*
1198                  * Adjust the header length according to the pad and
1199                  * the jumbo payload option.
1200                  */
1201                 hbh = mtod(mopt, struct ip6_hbh *);
1202                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1203         }
1204
1205         /* fill in the option. */
1206         optbuf[2] = IP6OPT_JUMBO;
1207         optbuf[3] = 4;
1208         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1209         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1210
1211         /* finally, adjust the packet header length */
1212         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1213
1214         return (0);
1215 #undef JUMBOOPTLEN
1216 }
1217
1218 /*
1219  * Insert fragment header and copy unfragmentable header portions.
1220  */
1221 static int
1222 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1223     struct ip6_frag **frghdrp)
1224 {
1225         struct mbuf *n, *mlast;
1226
1227         if (hlen > sizeof(struct ip6_hdr)) {
1228                 n = m_copym(m0, sizeof(struct ip6_hdr),
1229                     hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1230                 if (n == NULL)
1231                         return (ENOBUFS);
1232                 m->m_next = n;
1233         } else
1234                 n = m;
1235
1236         /* Search for the last mbuf of unfragmentable part. */
1237         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1238                 ;
1239
1240         if (M_WRITABLE(mlast) &&
1241             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1242                 /* use the trailing space of the last mbuf for the fragment hdr */
1243                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1244                     mlast->m_len);
1245                 mlast->m_len += sizeof(struct ip6_frag);
1246                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1247         } else {
1248                 /* allocate a new mbuf for the fragment header */
1249                 struct mbuf *mfrg;
1250
1251                 mfrg = m_get(M_NOWAIT, MT_DATA);
1252                 if (mfrg == NULL)
1253                         return (ENOBUFS);
1254                 mfrg->m_len = sizeof(struct ip6_frag);
1255                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1256                 mlast->m_next = mfrg;
1257         }
1258
1259         return (0);
1260 }
1261
1262 /*
1263  * Calculates IPv6 path mtu for destination @dst.
1264  * Resulting MTU is stored in @mtup.
1265  *
1266  * Returns 0 on success.
1267  */
1268 static int
1269 ip6_getpmtu_ctl(u_int fibnum, const struct in6_addr *dst, u_long *mtup)
1270 {
1271         struct nhop6_extended nh6;
1272         struct in6_addr kdst;
1273         uint32_t scopeid;
1274         struct ifnet *ifp;
1275         u_long mtu;
1276         int error;
1277
1278         in6_splitscope(dst, &kdst, &scopeid);
1279         if (fib6_lookup_nh_ext(fibnum, &kdst, scopeid, NHR_REF, 0, &nh6) != 0)
1280                 return (EHOSTUNREACH);
1281
1282         ifp = nh6.nh_ifp;
1283         mtu = nh6.nh_mtu;
1284
1285         error = ip6_calcmtu(ifp, dst, mtu, mtup, NULL, 0);
1286         fib6_free_nh_ext(fibnum, &nh6);
1287
1288         return (error);
1289 }
1290
1291 /*
1292  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1293  * and cached data in @ro_pmtu.
1294  * MTU from (successful) route lookup is saved (along with dst)
1295  * inside @ro_pmtu to avoid subsequent route lookups after packet
1296  * filter processing.
1297  *
1298  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1299  * Returns 0 on success.
1300  */
1301 static int
1302 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1303     struct ifnet *ifp, const struct in6_addr *dst, u_long *mtup,
1304     int *alwaysfragp, u_int fibnum, u_int proto)
1305 {
1306         struct nhop6_basic nh6;
1307         struct in6_addr kdst;
1308         uint32_t scopeid;
1309         struct sockaddr_in6 *sa6_dst;
1310         u_long mtu;
1311
1312         mtu = 0;
1313         if (do_lookup) {
1314
1315                 /*
1316                  * Here ro_pmtu has final destination address, while
1317                  * ro might represent immediate destination.
1318                  * Use ro_pmtu destination since mtu might differ.
1319                  */
1320                 sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1321                 if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1322                         ro_pmtu->ro_mtu = 0;
1323
1324                 if (ro_pmtu->ro_mtu == 0) {
1325                         bzero(sa6_dst, sizeof(*sa6_dst));
1326                         sa6_dst->sin6_family = AF_INET6;
1327                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1328                         sa6_dst->sin6_addr = *dst;
1329
1330                         in6_splitscope(dst, &kdst, &scopeid);
1331                         if (fib6_lookup_nh_basic(fibnum, &kdst, scopeid, 0, 0,
1332                             &nh6) == 0)
1333                                 ro_pmtu->ro_mtu = nh6.nh_mtu;
1334                 }
1335
1336                 mtu = ro_pmtu->ro_mtu;
1337         }
1338
1339         if (ro_pmtu->ro_rt)
1340                 mtu = ro_pmtu->ro_rt->rt_mtu;
1341
1342         return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp, proto));
1343 }
1344
1345 /*
1346  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1347  * hostcache data for @dst.
1348  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1349  *
1350  * Returns 0 on success.
1351  */
1352 static int
1353 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1354     u_long *mtup, int *alwaysfragp, u_int proto)
1355 {
1356         u_long mtu = 0;
1357         int alwaysfrag = 0;
1358         int error = 0;
1359
1360         if (rt_mtu > 0) {
1361                 u_int32_t ifmtu;
1362                 struct in_conninfo inc;
1363
1364                 bzero(&inc, sizeof(inc));
1365                 inc.inc_flags |= INC_ISIPV6;
1366                 inc.inc6_faddr = *dst;
1367
1368                 ifmtu = IN6_LINKMTU(ifp);
1369
1370                 /* TCP is known to react to pmtu changes so skip hc */
1371                 if (proto != IPPROTO_TCP)
1372                         mtu = tcp_hc_getmtu(&inc);
1373
1374                 if (mtu)
1375                         mtu = min(mtu, rt_mtu);
1376                 else
1377                         mtu = rt_mtu;
1378                 if (mtu == 0)
1379                         mtu = ifmtu;
1380                 else if (mtu < IPV6_MMTU) {
1381                         /*
1382                          * RFC2460 section 5, last paragraph:
1383                          * if we record ICMPv6 too big message with
1384                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1385                          * or smaller, with framgent header attached.
1386                          * (fragment header is needed regardless from the
1387                          * packet size, for translators to identify packets)
1388                          */
1389                         alwaysfrag = 1;
1390                         mtu = IPV6_MMTU;
1391                 }
1392         } else if (ifp) {
1393                 mtu = IN6_LINKMTU(ifp);
1394         } else
1395                 error = EHOSTUNREACH; /* XXX */
1396
1397         *mtup = mtu;
1398         if (alwaysfragp)
1399                 *alwaysfragp = alwaysfrag;
1400         return (error);
1401 }
1402
1403 /*
1404  * IP6 socket option processing.
1405  */
1406 int
1407 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1408 {
1409         int optdatalen, uproto;
1410         void *optdata;
1411         struct inpcb *in6p = sotoinpcb(so);
1412         int error, optval;
1413         int level, op, optname;
1414         int optlen;
1415         struct thread *td;
1416 #ifdef  RSS
1417         uint32_t rss_bucket;
1418         int retval;
1419 #endif
1420
1421 /*
1422  * Don't use more than a quarter of mbuf clusters.  N.B.:
1423  * nmbclusters is an int, but nmbclusters * MCLBYTES may overflow
1424  * on LP64 architectures, so cast to u_long to avoid undefined
1425  * behavior.  ILP32 architectures cannot have nmbclusters
1426  * large enough to overflow for other reasons.
1427  */
1428 #define IPV6_PKTOPTIONS_MBUF_LIMIT      ((u_long)nmbclusters * MCLBYTES / 4)
1429
1430         level = sopt->sopt_level;
1431         op = sopt->sopt_dir;
1432         optname = sopt->sopt_name;
1433         optlen = sopt->sopt_valsize;
1434         td = sopt->sopt_td;
1435         error = 0;
1436         optval = 0;
1437         uproto = (int)so->so_proto->pr_protocol;
1438
1439         if (level != IPPROTO_IPV6) {
1440                 error = EINVAL;
1441
1442                 if (sopt->sopt_level == SOL_SOCKET &&
1443                     sopt->sopt_dir == SOPT_SET) {
1444                         switch (sopt->sopt_name) {
1445                         case SO_REUSEADDR:
1446                                 INP_WLOCK(in6p);
1447                                 if ((so->so_options & SO_REUSEADDR) != 0)
1448                                         in6p->inp_flags2 |= INP_REUSEADDR;
1449                                 else
1450                                         in6p->inp_flags2 &= ~INP_REUSEADDR;
1451                                 INP_WUNLOCK(in6p);
1452                                 error = 0;
1453                                 break;
1454                         case SO_REUSEPORT:
1455                                 INP_WLOCK(in6p);
1456                                 if ((so->so_options & SO_REUSEPORT) != 0)
1457                                         in6p->inp_flags2 |= INP_REUSEPORT;
1458                                 else
1459                                         in6p->inp_flags2 &= ~INP_REUSEPORT;
1460                                 INP_WUNLOCK(in6p);
1461                                 error = 0;
1462                                 break;
1463                         case SO_REUSEPORT_LB:
1464                                 INP_WLOCK(in6p);
1465                                 if ((so->so_options & SO_REUSEPORT_LB) != 0)
1466                                         in6p->inp_flags2 |= INP_REUSEPORT_LB;
1467                                 else
1468                                         in6p->inp_flags2 &= ~INP_REUSEPORT_LB;
1469                                 INP_WUNLOCK(in6p);
1470                                 error = 0;
1471                                 break;
1472                         case SO_SETFIB:
1473                                 INP_WLOCK(in6p);
1474                                 in6p->inp_inc.inc_fibnum = so->so_fibnum;
1475                                 INP_WUNLOCK(in6p);
1476                                 error = 0;
1477                                 break;
1478                         case SO_MAX_PACING_RATE:
1479 #ifdef RATELIMIT
1480                                 INP_WLOCK(in6p);
1481                                 in6p->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1482                                 INP_WUNLOCK(in6p);
1483                                 error = 0;
1484 #else
1485                                 error = EOPNOTSUPP;
1486 #endif
1487                                 break;
1488                         default:
1489                                 break;
1490                         }
1491                 }
1492         } else {                /* level == IPPROTO_IPV6 */
1493                 switch (op) {
1494
1495                 case SOPT_SET:
1496                         switch (optname) {
1497                         case IPV6_2292PKTOPTIONS:
1498 #ifdef IPV6_PKTOPTIONS
1499                         case IPV6_PKTOPTIONS:
1500 #endif
1501                         {
1502                                 struct mbuf *m;
1503
1504                                 if (optlen > IPV6_PKTOPTIONS_MBUF_LIMIT) {
1505                                         printf("ip6_ctloutput: mbuf limit hit\n");
1506                                         error = ENOBUFS;
1507                                         break;
1508                                 }
1509
1510                                 error = soopt_getm(sopt, &m); /* XXX */
1511                                 if (error != 0)
1512                                         break;
1513                                 error = soopt_mcopyin(sopt, m); /* XXX */
1514                                 if (error != 0)
1515                                         break;
1516                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1517                                                     m, so, sopt);
1518                                 m_freem(m); /* XXX */
1519                                 break;
1520                         }
1521
1522                         /*
1523                          * Use of some Hop-by-Hop options or some
1524                          * Destination options, might require special
1525                          * privilege.  That is, normal applications
1526                          * (without special privilege) might be forbidden
1527                          * from setting certain options in outgoing packets,
1528                          * and might never see certain options in received
1529                          * packets. [RFC 2292 Section 6]
1530                          * KAME specific note:
1531                          *  KAME prevents non-privileged users from sending or
1532                          *  receiving ANY hbh/dst options in order to avoid
1533                          *  overhead of parsing options in the kernel.
1534                          */
1535                         case IPV6_RECVHOPOPTS:
1536                         case IPV6_RECVDSTOPTS:
1537                         case IPV6_RECVRTHDRDSTOPTS:
1538                                 if (td != NULL) {
1539                                         error = priv_check(td,
1540                                             PRIV_NETINET_SETHDROPTS);
1541                                         if (error)
1542                                                 break;
1543                                 }
1544                                 /* FALLTHROUGH */
1545                         case IPV6_UNICAST_HOPS:
1546                         case IPV6_HOPLIMIT:
1547
1548                         case IPV6_RECVPKTINFO:
1549                         case IPV6_RECVHOPLIMIT:
1550                         case IPV6_RECVRTHDR:
1551                         case IPV6_RECVPATHMTU:
1552                         case IPV6_RECVTCLASS:
1553                         case IPV6_RECVFLOWID:
1554 #ifdef  RSS
1555                         case IPV6_RECVRSSBUCKETID:
1556 #endif
1557                         case IPV6_V6ONLY:
1558                         case IPV6_AUTOFLOWLABEL:
1559                         case IPV6_ORIGDSTADDR:
1560                         case IPV6_BINDANY:
1561                         case IPV6_BINDMULTI:
1562 #ifdef  RSS
1563                         case IPV6_RSS_LISTEN_BUCKET:
1564 #endif
1565                                 if (optname == IPV6_BINDANY && td != NULL) {
1566                                         error = priv_check(td,
1567                                             PRIV_NETINET_BINDANY);
1568                                         if (error)
1569                                                 break;
1570                                 }
1571
1572                                 if (optlen != sizeof(int)) {
1573                                         error = EINVAL;
1574                                         break;
1575                                 }
1576                                 error = sooptcopyin(sopt, &optval,
1577                                         sizeof optval, sizeof optval);
1578                                 if (error)
1579                                         break;
1580                                 switch (optname) {
1581
1582                                 case IPV6_UNICAST_HOPS:
1583                                         if (optval < -1 || optval >= 256)
1584                                                 error = EINVAL;
1585                                         else {
1586                                                 /* -1 = kernel default */
1587                                                 in6p->in6p_hops = optval;
1588                                                 if ((in6p->inp_vflag &
1589                                                      INP_IPV4) != 0)
1590                                                         in6p->inp_ip_ttl = optval;
1591                                         }
1592                                         break;
1593 #define OPTSET(bit) \
1594 do { \
1595         INP_WLOCK(in6p); \
1596         if (optval) \
1597                 in6p->inp_flags |= (bit); \
1598         else \
1599                 in6p->inp_flags &= ~(bit); \
1600         INP_WUNLOCK(in6p); \
1601 } while (/*CONSTCOND*/ 0)
1602 #define OPTSET2292(bit) \
1603 do { \
1604         INP_WLOCK(in6p); \
1605         in6p->inp_flags |= IN6P_RFC2292; \
1606         if (optval) \
1607                 in6p->inp_flags |= (bit); \
1608         else \
1609                 in6p->inp_flags &= ~(bit); \
1610         INP_WUNLOCK(in6p); \
1611 } while (/*CONSTCOND*/ 0)
1612 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1613
1614 #define OPTSET2_N(bit, val) do {                                        \
1615         if (val)                                                        \
1616                 in6p->inp_flags2 |= bit;                                \
1617         else                                                            \
1618                 in6p->inp_flags2 &= ~bit;                               \
1619 } while (0)
1620 #define OPTSET2(bit, val) do {                                          \
1621         INP_WLOCK(in6p);                                                \
1622         OPTSET2_N(bit, val);                                            \
1623         INP_WUNLOCK(in6p);                                              \
1624 } while (0)
1625 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1626 #define OPTSET2292_EXCLUSIVE(bit)                                       \
1627 do {                                                                    \
1628         INP_WLOCK(in6p);                                                \
1629         if (OPTBIT(IN6P_RFC2292)) {                                     \
1630                 error = EINVAL;                                         \
1631         } else {                                                        \
1632                 if (optval)                                             \
1633                         in6p->inp_flags |= (bit);                       \
1634                 else                                                    \
1635                         in6p->inp_flags &= ~(bit);                      \
1636         }                                                               \
1637         INP_WUNLOCK(in6p);                                              \
1638 } while (/*CONSTCOND*/ 0)
1639
1640                                 case IPV6_RECVPKTINFO:
1641                                         OPTSET2292_EXCLUSIVE(IN6P_PKTINFO);
1642                                         break;
1643
1644                                 case IPV6_HOPLIMIT:
1645                                 {
1646                                         struct ip6_pktopts **optp;
1647
1648                                         /* cannot mix with RFC2292 */
1649                                         if (OPTBIT(IN6P_RFC2292)) {
1650                                                 error = EINVAL;
1651                                                 break;
1652                                         }
1653                                         INP_WLOCK(in6p);
1654                                         if (in6p->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1655                                                 INP_WUNLOCK(in6p);
1656                                                 return (ECONNRESET);
1657                                         }
1658                                         optp = &in6p->in6p_outputopts;
1659                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1660                                             (u_char *)&optval, sizeof(optval),
1661                                             optp, (td != NULL) ? td->td_ucred :
1662                                             NULL, uproto);
1663                                         INP_WUNLOCK(in6p);
1664                                         break;
1665                                 }
1666
1667                                 case IPV6_RECVHOPLIMIT:
1668                                         OPTSET2292_EXCLUSIVE(IN6P_HOPLIMIT);
1669                                         break;
1670
1671                                 case IPV6_RECVHOPOPTS:
1672                                         OPTSET2292_EXCLUSIVE(IN6P_HOPOPTS);
1673                                         break;
1674
1675                                 case IPV6_RECVDSTOPTS:
1676                                         OPTSET2292_EXCLUSIVE(IN6P_DSTOPTS);
1677                                         break;
1678
1679                                 case IPV6_RECVRTHDRDSTOPTS:
1680                                         OPTSET2292_EXCLUSIVE(IN6P_RTHDRDSTOPTS);
1681                                         break;
1682
1683                                 case IPV6_RECVRTHDR:
1684                                         OPTSET2292_EXCLUSIVE(IN6P_RTHDR);
1685                                         break;
1686
1687                                 case IPV6_RECVPATHMTU:
1688                                         /*
1689                                          * We ignore this option for TCP
1690                                          * sockets.
1691                                          * (RFC3542 leaves this case
1692                                          * unspecified.)
1693                                          */
1694                                         if (uproto != IPPROTO_TCP)
1695                                                 OPTSET(IN6P_MTU);
1696                                         break;
1697
1698                                 case IPV6_RECVFLOWID:
1699                                         OPTSET2(INP_RECVFLOWID, optval);
1700                                         break;
1701
1702 #ifdef  RSS
1703                                 case IPV6_RECVRSSBUCKETID:
1704                                         OPTSET2(INP_RECVRSSBUCKETID, optval);
1705                                         break;
1706 #endif
1707
1708                                 case IPV6_V6ONLY:
1709                                         /*
1710                                          * make setsockopt(IPV6_V6ONLY)
1711                                          * available only prior to bind(2).
1712                                          * see ipng mailing list, Jun 22 2001.
1713                                          */
1714                                         if (in6p->inp_lport ||
1715                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1716                                                 error = EINVAL;
1717                                                 break;
1718                                         }
1719                                         OPTSET(IN6P_IPV6_V6ONLY);
1720                                         if (optval)
1721                                                 in6p->inp_vflag &= ~INP_IPV4;
1722                                         else
1723                                                 in6p->inp_vflag |= INP_IPV4;
1724                                         break;
1725                                 case IPV6_RECVTCLASS:
1726                                         /* cannot mix with RFC2292 XXX */
1727                                         OPTSET2292_EXCLUSIVE(IN6P_TCLASS);
1728                                         break;
1729                                 case IPV6_AUTOFLOWLABEL:
1730                                         OPTSET(IN6P_AUTOFLOWLABEL);
1731                                         break;
1732
1733                                 case IPV6_ORIGDSTADDR:
1734                                         OPTSET2(INP_ORIGDSTADDR, optval);
1735                                         break;
1736                                 case IPV6_BINDANY:
1737                                         OPTSET(INP_BINDANY);
1738                                         break;
1739
1740                                 case IPV6_BINDMULTI:
1741                                         OPTSET2(INP_BINDMULTI, optval);
1742                                         break;
1743 #ifdef  RSS
1744                                 case IPV6_RSS_LISTEN_BUCKET:
1745                                         if ((optval >= 0) &&
1746                                             (optval < rss_getnumbuckets())) {
1747                                                 INP_WLOCK(in6p);
1748                                                 in6p->inp_rss_listen_bucket = optval;
1749                                                 OPTSET2_N(INP_RSS_BUCKET_SET, 1);
1750                                                 INP_WUNLOCK(in6p);
1751                                         } else {
1752                                                 error = EINVAL;
1753                                         }
1754                                         break;
1755 #endif
1756                                 }
1757                                 break;
1758
1759                         case IPV6_TCLASS:
1760                         case IPV6_DONTFRAG:
1761                         case IPV6_USE_MIN_MTU:
1762                         case IPV6_PREFER_TEMPADDR:
1763                                 if (optlen != sizeof(optval)) {
1764                                         error = EINVAL;
1765                                         break;
1766                                 }
1767                                 error = sooptcopyin(sopt, &optval,
1768                                         sizeof optval, sizeof optval);
1769                                 if (error)
1770                                         break;
1771                                 {
1772                                         struct ip6_pktopts **optp;
1773                                         INP_WLOCK(in6p);
1774                                         if (in6p->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1775                                                 INP_WUNLOCK(in6p);
1776                                                 return (ECONNRESET);
1777                                         }
1778                                         optp = &in6p->in6p_outputopts;
1779                                         error = ip6_pcbopt(optname,
1780                                             (u_char *)&optval, sizeof(optval),
1781                                             optp, (td != NULL) ? td->td_ucred :
1782                                             NULL, uproto);
1783                                         INP_WUNLOCK(in6p);
1784                                         break;
1785                                 }
1786
1787                         case IPV6_2292PKTINFO:
1788                         case IPV6_2292HOPLIMIT:
1789                         case IPV6_2292HOPOPTS:
1790                         case IPV6_2292DSTOPTS:
1791                         case IPV6_2292RTHDR:
1792                                 /* RFC 2292 */
1793                                 if (optlen != sizeof(int)) {
1794                                         error = EINVAL;
1795                                         break;
1796                                 }
1797                                 error = sooptcopyin(sopt, &optval,
1798                                         sizeof optval, sizeof optval);
1799                                 if (error)
1800                                         break;
1801                                 switch (optname) {
1802                                 case IPV6_2292PKTINFO:
1803                                         OPTSET2292(IN6P_PKTINFO);
1804                                         break;
1805                                 case IPV6_2292HOPLIMIT:
1806                                         OPTSET2292(IN6P_HOPLIMIT);
1807                                         break;
1808                                 case IPV6_2292HOPOPTS:
1809                                         /*
1810                                          * Check super-user privilege.
1811                                          * See comments for IPV6_RECVHOPOPTS.
1812                                          */
1813                                         if (td != NULL) {
1814                                                 error = priv_check(td,
1815                                                     PRIV_NETINET_SETHDROPTS);
1816                                                 if (error)
1817                                                         return (error);
1818                                         }
1819                                         OPTSET2292(IN6P_HOPOPTS);
1820                                         break;
1821                                 case IPV6_2292DSTOPTS:
1822                                         if (td != NULL) {
1823                                                 error = priv_check(td,
1824                                                     PRIV_NETINET_SETHDROPTS);
1825                                                 if (error)
1826                                                         return (error);
1827                                         }
1828                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1829                                         break;
1830                                 case IPV6_2292RTHDR:
1831                                         OPTSET2292(IN6P_RTHDR);
1832                                         break;
1833                                 }
1834                                 break;
1835                         case IPV6_PKTINFO:
1836                         case IPV6_HOPOPTS:
1837                         case IPV6_RTHDR:
1838                         case IPV6_DSTOPTS:
1839                         case IPV6_RTHDRDSTOPTS:
1840                         case IPV6_NEXTHOP:
1841                         {
1842                                 /* new advanced API (RFC3542) */
1843                                 u_char *optbuf;
1844                                 u_char optbuf_storage[MCLBYTES];
1845                                 int optlen;
1846                                 struct ip6_pktopts **optp;
1847
1848                                 /* cannot mix with RFC2292 */
1849                                 if (OPTBIT(IN6P_RFC2292)) {
1850                                         error = EINVAL;
1851                                         break;
1852                                 }
1853
1854                                 /*
1855                                  * We only ensure valsize is not too large
1856                                  * here.  Further validation will be done
1857                                  * later.
1858                                  */
1859                                 error = sooptcopyin(sopt, optbuf_storage,
1860                                     sizeof(optbuf_storage), 0);
1861                                 if (error)
1862                                         break;
1863                                 optlen = sopt->sopt_valsize;
1864                                 optbuf = optbuf_storage;
1865                                 INP_WLOCK(in6p);
1866                                 if (in6p->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
1867                                         INP_WUNLOCK(in6p);
1868                                         return (ECONNRESET);
1869                                 }
1870                                 optp = &in6p->in6p_outputopts;
1871                                 error = ip6_pcbopt(optname, optbuf, optlen,
1872                                     optp, (td != NULL) ? td->td_ucred : NULL,
1873                                     uproto);
1874                                 INP_WUNLOCK(in6p);
1875                                 break;
1876                         }
1877 #undef OPTSET
1878
1879                         case IPV6_MULTICAST_IF:
1880                         case IPV6_MULTICAST_HOPS:
1881                         case IPV6_MULTICAST_LOOP:
1882                         case IPV6_JOIN_GROUP:
1883                         case IPV6_LEAVE_GROUP:
1884                         case IPV6_MSFILTER:
1885                         case MCAST_BLOCK_SOURCE:
1886                         case MCAST_UNBLOCK_SOURCE:
1887                         case MCAST_JOIN_GROUP:
1888                         case MCAST_LEAVE_GROUP:
1889                         case MCAST_JOIN_SOURCE_GROUP:
1890                         case MCAST_LEAVE_SOURCE_GROUP:
1891                                 error = ip6_setmoptions(in6p, sopt);
1892                                 break;
1893
1894                         case IPV6_PORTRANGE:
1895                                 error = sooptcopyin(sopt, &optval,
1896                                     sizeof optval, sizeof optval);
1897                                 if (error)
1898                                         break;
1899
1900                                 INP_WLOCK(in6p);
1901                                 switch (optval) {
1902                                 case IPV6_PORTRANGE_DEFAULT:
1903                                         in6p->inp_flags &= ~(INP_LOWPORT);
1904                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1905                                         break;
1906
1907                                 case IPV6_PORTRANGE_HIGH:
1908                                         in6p->inp_flags &= ~(INP_LOWPORT);
1909                                         in6p->inp_flags |= INP_HIGHPORT;
1910                                         break;
1911
1912                                 case IPV6_PORTRANGE_LOW:
1913                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1914                                         in6p->inp_flags |= INP_LOWPORT;
1915                                         break;
1916
1917                                 default:
1918                                         error = EINVAL;
1919                                         break;
1920                                 }
1921                                 INP_WUNLOCK(in6p);
1922                                 break;
1923
1924 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1925                         case IPV6_IPSEC_POLICY:
1926                                 if (IPSEC_ENABLED(ipv6)) {
1927                                         error = IPSEC_PCBCTL(ipv6, in6p, sopt);
1928                                         break;
1929                                 }
1930                                 /* FALLTHROUGH */
1931 #endif /* IPSEC */
1932
1933                         default:
1934                                 error = ENOPROTOOPT;
1935                                 break;
1936                         }
1937                         break;
1938
1939                 case SOPT_GET:
1940                         switch (optname) {
1941
1942                         case IPV6_2292PKTOPTIONS:
1943 #ifdef IPV6_PKTOPTIONS
1944                         case IPV6_PKTOPTIONS:
1945 #endif
1946                                 /*
1947                                  * RFC3542 (effectively) deprecated the
1948                                  * semantics of the 2292-style pktoptions.
1949                                  * Since it was not reliable in nature (i.e.,
1950                                  * applications had to expect the lack of some
1951                                  * information after all), it would make sense
1952                                  * to simplify this part by always returning
1953                                  * empty data.
1954                                  */
1955                                 sopt->sopt_valsize = 0;
1956                                 break;
1957
1958                         case IPV6_RECVHOPOPTS:
1959                         case IPV6_RECVDSTOPTS:
1960                         case IPV6_RECVRTHDRDSTOPTS:
1961                         case IPV6_UNICAST_HOPS:
1962                         case IPV6_RECVPKTINFO:
1963                         case IPV6_RECVHOPLIMIT:
1964                         case IPV6_RECVRTHDR:
1965                         case IPV6_RECVPATHMTU:
1966
1967                         case IPV6_V6ONLY:
1968                         case IPV6_PORTRANGE:
1969                         case IPV6_RECVTCLASS:
1970                         case IPV6_AUTOFLOWLABEL:
1971                         case IPV6_BINDANY:
1972                         case IPV6_FLOWID:
1973                         case IPV6_FLOWTYPE:
1974                         case IPV6_RECVFLOWID:
1975 #ifdef  RSS
1976                         case IPV6_RSSBUCKETID:
1977                         case IPV6_RECVRSSBUCKETID:
1978 #endif
1979                         case IPV6_BINDMULTI:
1980                                 switch (optname) {
1981
1982                                 case IPV6_RECVHOPOPTS:
1983                                         optval = OPTBIT(IN6P_HOPOPTS);
1984                                         break;
1985
1986                                 case IPV6_RECVDSTOPTS:
1987                                         optval = OPTBIT(IN6P_DSTOPTS);
1988                                         break;
1989
1990                                 case IPV6_RECVRTHDRDSTOPTS:
1991                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1992                                         break;
1993
1994                                 case IPV6_UNICAST_HOPS:
1995                                         optval = in6p->in6p_hops;
1996                                         break;
1997
1998                                 case IPV6_RECVPKTINFO:
1999                                         optval = OPTBIT(IN6P_PKTINFO);
2000                                         break;
2001
2002                                 case IPV6_RECVHOPLIMIT:
2003                                         optval = OPTBIT(IN6P_HOPLIMIT);
2004                                         break;
2005
2006                                 case IPV6_RECVRTHDR:
2007                                         optval = OPTBIT(IN6P_RTHDR);
2008                                         break;
2009
2010                                 case IPV6_RECVPATHMTU:
2011                                         optval = OPTBIT(IN6P_MTU);
2012                                         break;
2013
2014                                 case IPV6_V6ONLY:
2015                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
2016                                         break;
2017
2018                                 case IPV6_PORTRANGE:
2019                                     {
2020                                         int flags;
2021                                         flags = in6p->inp_flags;
2022                                         if (flags & INP_HIGHPORT)
2023                                                 optval = IPV6_PORTRANGE_HIGH;
2024                                         else if (flags & INP_LOWPORT)
2025                                                 optval = IPV6_PORTRANGE_LOW;
2026                                         else
2027                                                 optval = 0;
2028                                         break;
2029                                     }
2030                                 case IPV6_RECVTCLASS:
2031                                         optval = OPTBIT(IN6P_TCLASS);
2032                                         break;
2033
2034                                 case IPV6_AUTOFLOWLABEL:
2035                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2036                                         break;
2037
2038                                 case IPV6_ORIGDSTADDR:
2039                                         optval = OPTBIT2(INP_ORIGDSTADDR);
2040                                         break;
2041
2042                                 case IPV6_BINDANY:
2043                                         optval = OPTBIT(INP_BINDANY);
2044                                         break;
2045
2046                                 case IPV6_FLOWID:
2047                                         optval = in6p->inp_flowid;
2048                                         break;
2049
2050                                 case IPV6_FLOWTYPE:
2051                                         optval = in6p->inp_flowtype;
2052                                         break;
2053
2054                                 case IPV6_RECVFLOWID:
2055                                         optval = OPTBIT2(INP_RECVFLOWID);
2056                                         break;
2057 #ifdef  RSS
2058                                 case IPV6_RSSBUCKETID:
2059                                         retval =
2060                                             rss_hash2bucket(in6p->inp_flowid,
2061                                             in6p->inp_flowtype,
2062                                             &rss_bucket);
2063                                         if (retval == 0)
2064                                                 optval = rss_bucket;
2065                                         else
2066                                                 error = EINVAL;
2067                                         break;
2068
2069                                 case IPV6_RECVRSSBUCKETID:
2070                                         optval = OPTBIT2(INP_RECVRSSBUCKETID);
2071                                         break;
2072 #endif
2073
2074                                 case IPV6_BINDMULTI:
2075                                         optval = OPTBIT2(INP_BINDMULTI);
2076                                         break;
2077
2078                                 }
2079                                 if (error)
2080                                         break;
2081                                 error = sooptcopyout(sopt, &optval,
2082                                         sizeof optval);
2083                                 break;
2084
2085                         case IPV6_PATHMTU:
2086                         {
2087                                 u_long pmtu = 0;
2088                                 struct ip6_mtuinfo mtuinfo;
2089                                 struct in6_addr addr;
2090
2091                                 if (!(so->so_state & SS_ISCONNECTED))
2092                                         return (ENOTCONN);
2093                                 /*
2094                                  * XXX: we dot not consider the case of source
2095                                  * routing, or optional information to specify
2096                                  * the outgoing interface.
2097                                  * Copy faddr out of in6p to avoid holding lock
2098                                  * on inp during route lookup.
2099                                  */
2100                                 INP_RLOCK(in6p);
2101                                 bcopy(&in6p->in6p_faddr, &addr, sizeof(addr));
2102                                 INP_RUNLOCK(in6p);
2103                                 error = ip6_getpmtu_ctl(so->so_fibnum,
2104                                     &addr, &pmtu);
2105                                 if (error)
2106                                         break;
2107                                 if (pmtu > IPV6_MAXPACKET)
2108                                         pmtu = IPV6_MAXPACKET;
2109
2110                                 bzero(&mtuinfo, sizeof(mtuinfo));
2111                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2112                                 optdata = (void *)&mtuinfo;
2113                                 optdatalen = sizeof(mtuinfo);
2114                                 error = sooptcopyout(sopt, optdata,
2115                                     optdatalen);
2116                                 break;
2117                         }
2118
2119                         case IPV6_2292PKTINFO:
2120                         case IPV6_2292HOPLIMIT:
2121                         case IPV6_2292HOPOPTS:
2122                         case IPV6_2292RTHDR:
2123                         case IPV6_2292DSTOPTS:
2124                                 switch (optname) {
2125                                 case IPV6_2292PKTINFO:
2126                                         optval = OPTBIT(IN6P_PKTINFO);
2127                                         break;
2128                                 case IPV6_2292HOPLIMIT:
2129                                         optval = OPTBIT(IN6P_HOPLIMIT);
2130                                         break;
2131                                 case IPV6_2292HOPOPTS:
2132                                         optval = OPTBIT(IN6P_HOPOPTS);
2133                                         break;
2134                                 case IPV6_2292RTHDR:
2135                                         optval = OPTBIT(IN6P_RTHDR);
2136                                         break;
2137                                 case IPV6_2292DSTOPTS:
2138                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2139                                         break;
2140                                 }
2141                                 error = sooptcopyout(sopt, &optval,
2142                                     sizeof optval);
2143                                 break;
2144                         case IPV6_PKTINFO:
2145                         case IPV6_HOPOPTS:
2146                         case IPV6_RTHDR:
2147                         case IPV6_DSTOPTS:
2148                         case IPV6_RTHDRDSTOPTS:
2149                         case IPV6_NEXTHOP:
2150                         case IPV6_TCLASS:
2151                         case IPV6_DONTFRAG:
2152                         case IPV6_USE_MIN_MTU:
2153                         case IPV6_PREFER_TEMPADDR:
2154                                 error = ip6_getpcbopt(in6p, optname, sopt);
2155                                 break;
2156
2157                         case IPV6_MULTICAST_IF:
2158                         case IPV6_MULTICAST_HOPS:
2159                         case IPV6_MULTICAST_LOOP:
2160                         case IPV6_MSFILTER:
2161                                 error = ip6_getmoptions(in6p, sopt);
2162                                 break;
2163
2164 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2165                         case IPV6_IPSEC_POLICY:
2166                                 if (IPSEC_ENABLED(ipv6)) {
2167                                         error = IPSEC_PCBCTL(ipv6, in6p, sopt);
2168                                         break;
2169                                 }
2170                                 /* FALLTHROUGH */
2171 #endif /* IPSEC */
2172                         default:
2173                                 error = ENOPROTOOPT;
2174                                 break;
2175                         }
2176                         break;
2177                 }
2178         }
2179         return (error);
2180 }
2181
2182 int
2183 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2184 {
2185         int error = 0, optval, optlen;
2186         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2187         struct inpcb *in6p = sotoinpcb(so);
2188         int level, op, optname;
2189
2190         level = sopt->sopt_level;
2191         op = sopt->sopt_dir;
2192         optname = sopt->sopt_name;
2193         optlen = sopt->sopt_valsize;
2194
2195         if (level != IPPROTO_IPV6) {
2196                 return (EINVAL);
2197         }
2198
2199         switch (optname) {
2200         case IPV6_CHECKSUM:
2201                 /*
2202                  * For ICMPv6 sockets, no modification allowed for checksum
2203                  * offset, permit "no change" values to help existing apps.
2204                  *
2205                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2206                  * for an ICMPv6 socket will fail."
2207                  * The current behavior does not meet RFC3542.
2208                  */
2209                 switch (op) {
2210                 case SOPT_SET:
2211                         if (optlen != sizeof(int)) {
2212                                 error = EINVAL;
2213                                 break;
2214                         }
2215                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2216                                             sizeof(optval));
2217                         if (error)
2218                                 break;
2219                         if ((optval % 2) != 0) {
2220                                 /* the API assumes even offset values */
2221                                 error = EINVAL;
2222                         } else if (so->so_proto->pr_protocol ==
2223                             IPPROTO_ICMPV6) {
2224                                 if (optval != icmp6off)
2225                                         error = EINVAL;
2226                         } else
2227                                 in6p->in6p_cksum = optval;
2228                         break;
2229
2230                 case SOPT_GET:
2231                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2232                                 optval = icmp6off;
2233                         else
2234                                 optval = in6p->in6p_cksum;
2235
2236                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2237                         break;
2238
2239                 default:
2240                         error = EINVAL;
2241                         break;
2242                 }
2243                 break;
2244
2245         default:
2246                 error = ENOPROTOOPT;
2247                 break;
2248         }
2249
2250         return (error);
2251 }
2252
2253 /*
2254  * Set up IP6 options in pcb for insertion in output packets or
2255  * specifying behavior of outgoing packets.
2256  */
2257 static int
2258 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2259     struct socket *so, struct sockopt *sopt)
2260 {
2261         struct ip6_pktopts *opt = *pktopt;
2262         int error = 0;
2263         struct thread *td = sopt->sopt_td;
2264
2265         /* turn off any old options. */
2266         if (opt) {
2267 #ifdef DIAGNOSTIC
2268                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2269                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2270                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2271                         printf("ip6_pcbopts: all specified options are cleared.\n");
2272 #endif
2273                 ip6_clearpktopts(opt, -1);
2274         } else
2275                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2276         *pktopt = NULL;
2277
2278         if (!m || m->m_len == 0) {
2279                 /*
2280                  * Only turning off any previous options, regardless of
2281                  * whether the opt is just created or given.
2282                  */
2283                 free(opt, M_IP6OPT);
2284                 return (0);
2285         }
2286
2287         /*  set options specified by user. */
2288         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2289             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2290                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2291                 free(opt, M_IP6OPT);
2292                 return (error);
2293         }
2294         *pktopt = opt;
2295         return (0);
2296 }
2297
2298 /*
2299  * initialize ip6_pktopts.  beware that there are non-zero default values in
2300  * the struct.
2301  */
2302 void
2303 ip6_initpktopts(struct ip6_pktopts *opt)
2304 {
2305
2306         bzero(opt, sizeof(*opt));
2307         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2308         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2309         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2310         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2311 }
2312
2313 static int
2314 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2315     struct ucred *cred, int uproto)
2316 {
2317         struct ip6_pktopts *opt;
2318
2319         if (*pktopt == NULL) {
2320                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2321                     M_NOWAIT);
2322                 if (*pktopt == NULL)
2323                         return (ENOBUFS);
2324                 ip6_initpktopts(*pktopt);
2325         }
2326         opt = *pktopt;
2327
2328         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2329 }
2330
2331 #define GET_PKTOPT_VAR(field, lenexpr) do {                                     \
2332         if (pktopt && pktopt->field) {                                          \
2333                 INP_RUNLOCK(in6p);                                              \
2334                 optdata = malloc(sopt->sopt_valsize, M_TEMP, M_WAITOK);         \
2335                 malloc_optdata = true;                                          \
2336                 INP_RLOCK(in6p);                                                \
2337                 if (in6p->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {           \
2338                         INP_RUNLOCK(in6p);                                      \
2339                         free(optdata, M_TEMP);                                  \
2340                         return (ECONNRESET);                                    \
2341                 }                                                               \
2342                 pktopt = in6p->in6p_outputopts;                                 \
2343                 if (pktopt && pktopt->field) {                                  \
2344                         optdatalen = min(lenexpr, sopt->sopt_valsize);          \
2345                         bcopy(&pktopt->field, optdata, optdatalen);             \
2346                 } else {                                                        \
2347                         free(optdata, M_TEMP);                                  \
2348                         optdata = NULL;                                         \
2349                         malloc_optdata = false;                                 \
2350                 }                                                               \
2351         }                                                                       \
2352 } while(0)
2353
2354 #define GET_PKTOPT_EXT_HDR(field) GET_PKTOPT_VAR(field,                         \
2355         (((struct ip6_ext *)pktopt->field)->ip6e_len + 1) << 3)
2356
2357 #define GET_PKTOPT_SOCKADDR(field) GET_PKTOPT_VAR(field,                        \
2358         pktopt->field->sa_len)
2359
2360 static int
2361 ip6_getpcbopt(struct inpcb *in6p, int optname, struct sockopt *sopt)
2362 {
2363         void *optdata = NULL;
2364         bool malloc_optdata = false;
2365         int optdatalen = 0;
2366         int error = 0;
2367         struct in6_pktinfo null_pktinfo;
2368         int deftclass = 0, on;
2369         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2370         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2371         struct ip6_pktopts *pktopt;
2372
2373         INP_RLOCK(in6p);
2374         pktopt = in6p->in6p_outputopts;
2375
2376         switch (optname) {
2377         case IPV6_PKTINFO:
2378                 optdata = (void *)&null_pktinfo;
2379                 if (pktopt && pktopt->ip6po_pktinfo) {
2380                         bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2381                             sizeof(null_pktinfo));
2382                         in6_clearscope(&null_pktinfo.ipi6_addr);
2383                 } else {
2384                         /* XXX: we don't have to do this every time... */
2385                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2386                 }
2387                 optdatalen = sizeof(struct in6_pktinfo);
2388                 break;
2389         case IPV6_TCLASS:
2390                 if (pktopt && pktopt->ip6po_tclass >= 0)
2391                         deftclass = pktopt->ip6po_tclass;
2392                 optdata = (void *)&deftclass;
2393                 optdatalen = sizeof(int);
2394                 break;
2395         case IPV6_HOPOPTS:
2396                 GET_PKTOPT_EXT_HDR(ip6po_hbh);
2397                 break;
2398         case IPV6_RTHDR:
2399                 GET_PKTOPT_EXT_HDR(ip6po_rthdr);
2400                 break;
2401         case IPV6_RTHDRDSTOPTS:
2402                 GET_PKTOPT_EXT_HDR(ip6po_dest1);
2403                 break;
2404         case IPV6_DSTOPTS:
2405                 GET_PKTOPT_EXT_HDR(ip6po_dest2);
2406                 break;
2407         case IPV6_NEXTHOP:
2408                 GET_PKTOPT_SOCKADDR(ip6po_nexthop);
2409                 break;
2410         case IPV6_USE_MIN_MTU:
2411                 if (pktopt)
2412                         defminmtu = pktopt->ip6po_minmtu;
2413                 optdata = (void *)&defminmtu;
2414                 optdatalen = sizeof(int);
2415                 break;
2416         case IPV6_DONTFRAG:
2417                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2418                         on = 1;
2419                 else
2420                         on = 0;
2421                 optdata = (void *)&on;
2422                 optdatalen = sizeof(on);
2423                 break;
2424         case IPV6_PREFER_TEMPADDR:
2425                 if (pktopt)
2426                         defpreftemp = pktopt->ip6po_prefer_tempaddr;
2427                 optdata = (void *)&defpreftemp;
2428                 optdatalen = sizeof(int);
2429                 break;
2430         default:                /* should not happen */
2431 #ifdef DIAGNOSTIC
2432                 panic("ip6_getpcbopt: unexpected option\n");
2433 #endif
2434                 INP_RUNLOCK(in6p);
2435                 return (ENOPROTOOPT);
2436         }
2437         INP_RUNLOCK(in6p);
2438
2439         error = sooptcopyout(sopt, optdata, optdatalen);
2440         if (malloc_optdata)
2441                 free(optdata, M_TEMP);
2442
2443         return (error);
2444 }
2445
2446 void
2447 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2448 {
2449         if (pktopt == NULL)
2450                 return;
2451
2452         if (optname == -1 || optname == IPV6_PKTINFO) {
2453                 if (pktopt->ip6po_pktinfo)
2454                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2455                 pktopt->ip6po_pktinfo = NULL;
2456         }
2457         if (optname == -1 || optname == IPV6_HOPLIMIT)
2458                 pktopt->ip6po_hlim = -1;
2459         if (optname == -1 || optname == IPV6_TCLASS)
2460                 pktopt->ip6po_tclass = -1;
2461         if (optname == -1 || optname == IPV6_NEXTHOP) {
2462                 if (pktopt->ip6po_nextroute.ro_rt) {
2463                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2464                         pktopt->ip6po_nextroute.ro_rt = NULL;
2465                 }
2466                 if (pktopt->ip6po_nexthop)
2467                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2468                 pktopt->ip6po_nexthop = NULL;
2469         }
2470         if (optname == -1 || optname == IPV6_HOPOPTS) {
2471                 if (pktopt->ip6po_hbh)
2472                         free(pktopt->ip6po_hbh, M_IP6OPT);
2473                 pktopt->ip6po_hbh = NULL;
2474         }
2475         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2476                 if (pktopt->ip6po_dest1)
2477                         free(pktopt->ip6po_dest1, M_IP6OPT);
2478                 pktopt->ip6po_dest1 = NULL;
2479         }
2480         if (optname == -1 || optname == IPV6_RTHDR) {
2481                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2482                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2483                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2484                 if (pktopt->ip6po_route.ro_rt) {
2485                         RTFREE(pktopt->ip6po_route.ro_rt);
2486                         pktopt->ip6po_route.ro_rt = NULL;
2487                 }
2488         }
2489         if (optname == -1 || optname == IPV6_DSTOPTS) {
2490                 if (pktopt->ip6po_dest2)
2491                         free(pktopt->ip6po_dest2, M_IP6OPT);
2492                 pktopt->ip6po_dest2 = NULL;
2493         }
2494 }
2495
2496 #define PKTOPT_EXTHDRCPY(type) \
2497 do {\
2498         if (src->type) {\
2499                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2500                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2501                 if (dst->type == NULL)\
2502                         goto bad;\
2503                 bcopy(src->type, dst->type, hlen);\
2504         }\
2505 } while (/*CONSTCOND*/ 0)
2506
2507 static int
2508 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2509 {
2510         if (dst == NULL || src == NULL)  {
2511                 printf("ip6_clearpktopts: invalid argument\n");
2512                 return (EINVAL);
2513         }
2514
2515         dst->ip6po_hlim = src->ip6po_hlim;
2516         dst->ip6po_tclass = src->ip6po_tclass;
2517         dst->ip6po_flags = src->ip6po_flags;
2518         dst->ip6po_minmtu = src->ip6po_minmtu;
2519         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2520         if (src->ip6po_pktinfo) {
2521                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2522                     M_IP6OPT, canwait);
2523                 if (dst->ip6po_pktinfo == NULL)
2524                         goto bad;
2525                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2526         }
2527         if (src->ip6po_nexthop) {
2528                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2529                     M_IP6OPT, canwait);
2530                 if (dst->ip6po_nexthop == NULL)
2531                         goto bad;
2532                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2533                     src->ip6po_nexthop->sa_len);
2534         }
2535         PKTOPT_EXTHDRCPY(ip6po_hbh);
2536         PKTOPT_EXTHDRCPY(ip6po_dest1);
2537         PKTOPT_EXTHDRCPY(ip6po_dest2);
2538         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2539         return (0);
2540
2541   bad:
2542         ip6_clearpktopts(dst, -1);
2543         return (ENOBUFS);
2544 }
2545 #undef PKTOPT_EXTHDRCPY
2546
2547 struct ip6_pktopts *
2548 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2549 {
2550         int error;
2551         struct ip6_pktopts *dst;
2552
2553         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2554         if (dst == NULL)
2555                 return (NULL);
2556         ip6_initpktopts(dst);
2557
2558         if ((error = copypktopts(dst, src, canwait)) != 0) {
2559                 free(dst, M_IP6OPT);
2560                 return (NULL);
2561         }
2562
2563         return (dst);
2564 }
2565
2566 void
2567 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2568 {
2569         if (pktopt == NULL)
2570                 return;
2571
2572         ip6_clearpktopts(pktopt, -1);
2573
2574         free(pktopt, M_IP6OPT);
2575 }
2576
2577 /*
2578  * Set IPv6 outgoing packet options based on advanced API.
2579  */
2580 int
2581 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2582     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2583 {
2584         struct cmsghdr *cm = NULL;
2585
2586         if (control == NULL || opt == NULL)
2587                 return (EINVAL);
2588
2589         ip6_initpktopts(opt);
2590         if (stickyopt) {
2591                 int error;
2592
2593                 /*
2594                  * If stickyopt is provided, make a local copy of the options
2595                  * for this particular packet, then override them by ancillary
2596                  * objects.
2597                  * XXX: copypktopts() does not copy the cached route to a next
2598                  * hop (if any).  This is not very good in terms of efficiency,
2599                  * but we can allow this since this option should be rarely
2600                  * used.
2601                  */
2602                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2603                         return (error);
2604         }
2605
2606         /*
2607          * XXX: Currently, we assume all the optional information is stored
2608          * in a single mbuf.
2609          */
2610         if (control->m_next)
2611                 return (EINVAL);
2612
2613         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2614             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2615                 int error;
2616
2617                 if (control->m_len < CMSG_LEN(0))
2618                         return (EINVAL);
2619
2620                 cm = mtod(control, struct cmsghdr *);
2621                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2622                         return (EINVAL);
2623                 if (cm->cmsg_level != IPPROTO_IPV6)
2624                         continue;
2625
2626                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2627                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2628                 if (error)
2629                         return (error);
2630         }
2631
2632         return (0);
2633 }
2634
2635 /*
2636  * Set a particular packet option, as a sticky option or an ancillary data
2637  * item.  "len" can be 0 only when it's a sticky option.
2638  * We have 4 cases of combination of "sticky" and "cmsg":
2639  * "sticky=0, cmsg=0": impossible
2640  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2641  * "sticky=1, cmsg=0": RFC3542 socket option
2642  * "sticky=1, cmsg=1": RFC2292 socket option
2643  */
2644 static int
2645 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2646     struct ucred *cred, int sticky, int cmsg, int uproto)
2647 {
2648         int minmtupolicy, preftemp;
2649         int error;
2650
2651         if (!sticky && !cmsg) {
2652 #ifdef DIAGNOSTIC
2653                 printf("ip6_setpktopt: impossible case\n");
2654 #endif
2655                 return (EINVAL);
2656         }
2657
2658         /*
2659          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2660          * not be specified in the context of RFC3542.  Conversely,
2661          * RFC3542 types should not be specified in the context of RFC2292.
2662          */
2663         if (!cmsg) {
2664                 switch (optname) {
2665                 case IPV6_2292PKTINFO:
2666                 case IPV6_2292HOPLIMIT:
2667                 case IPV6_2292NEXTHOP:
2668                 case IPV6_2292HOPOPTS:
2669                 case IPV6_2292DSTOPTS:
2670                 case IPV6_2292RTHDR:
2671                 case IPV6_2292PKTOPTIONS:
2672                         return (ENOPROTOOPT);
2673                 }
2674         }
2675         if (sticky && cmsg) {
2676                 switch (optname) {
2677                 case IPV6_PKTINFO:
2678                 case IPV6_HOPLIMIT:
2679                 case IPV6_NEXTHOP:
2680                 case IPV6_HOPOPTS:
2681                 case IPV6_DSTOPTS:
2682                 case IPV6_RTHDRDSTOPTS:
2683                 case IPV6_RTHDR:
2684                 case IPV6_USE_MIN_MTU:
2685                 case IPV6_DONTFRAG:
2686                 case IPV6_TCLASS:
2687                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2688                         return (ENOPROTOOPT);
2689                 }
2690         }
2691
2692         switch (optname) {
2693         case IPV6_2292PKTINFO:
2694         case IPV6_PKTINFO:
2695         {
2696                 struct ifnet *ifp = NULL;
2697                 struct in6_pktinfo *pktinfo;
2698
2699                 if (len != sizeof(struct in6_pktinfo))
2700                         return (EINVAL);
2701
2702                 pktinfo = (struct in6_pktinfo *)buf;
2703
2704                 /*
2705                  * An application can clear any sticky IPV6_PKTINFO option by
2706                  * doing a "regular" setsockopt with ipi6_addr being
2707                  * in6addr_any and ipi6_ifindex being zero.
2708                  * [RFC 3542, Section 6]
2709                  */
2710                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2711                     pktinfo->ipi6_ifindex == 0 &&
2712                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2713                         ip6_clearpktopts(opt, optname);
2714                         break;
2715                 }
2716
2717                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2718                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2719                         return (EINVAL);
2720                 }
2721                 if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2722                         return (EINVAL);
2723                 /* validate the interface index if specified. */
2724                 if (pktinfo->ipi6_ifindex > V_if_index)
2725                          return (ENXIO);
2726                 if (pktinfo->ipi6_ifindex) {
2727                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2728                         if (ifp == NULL)
2729                                 return (ENXIO);
2730                 }
2731                 if (ifp != NULL && (ifp->if_afdata[AF_INET6] == NULL ||
2732                     (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0))
2733                         return (ENETDOWN);
2734
2735                 if (ifp != NULL &&
2736                     !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2737                         struct in6_ifaddr *ia;
2738
2739                         in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2740                         ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2741                         if (ia == NULL)
2742                                 return (EADDRNOTAVAIL);
2743                         ifa_free(&ia->ia_ifa);
2744                 }
2745                 /*
2746                  * We store the address anyway, and let in6_selectsrc()
2747                  * validate the specified address.  This is because ipi6_addr
2748                  * may not have enough information about its scope zone, and
2749                  * we may need additional information (such as outgoing
2750                  * interface or the scope zone of a destination address) to
2751                  * disambiguate the scope.
2752                  * XXX: the delay of the validation may confuse the
2753                  * application when it is used as a sticky option.
2754                  */
2755                 if (opt->ip6po_pktinfo == NULL) {
2756                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2757                             M_IP6OPT, M_NOWAIT);
2758                         if (opt->ip6po_pktinfo == NULL)
2759                                 return (ENOBUFS);
2760                 }
2761                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2762                 break;
2763         }
2764
2765         case IPV6_2292HOPLIMIT:
2766         case IPV6_HOPLIMIT:
2767         {
2768                 int *hlimp;
2769
2770                 /*
2771                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2772                  * to simplify the ordering among hoplimit options.
2773                  */
2774                 if (optname == IPV6_HOPLIMIT && sticky)
2775                         return (ENOPROTOOPT);
2776
2777                 if (len != sizeof(int))
2778                         return (EINVAL);
2779                 hlimp = (int *)buf;
2780                 if (*hlimp < -1 || *hlimp > 255)
2781                         return (EINVAL);
2782
2783                 opt->ip6po_hlim = *hlimp;
2784                 break;
2785         }
2786
2787         case IPV6_TCLASS:
2788         {
2789                 int tclass;
2790
2791                 if (len != sizeof(int))
2792                         return (EINVAL);
2793                 tclass = *(int *)buf;
2794                 if (tclass < -1 || tclass > 255)
2795                         return (EINVAL);
2796
2797                 opt->ip6po_tclass = tclass;
2798                 break;
2799         }
2800
2801         case IPV6_2292NEXTHOP:
2802         case IPV6_NEXTHOP:
2803                 if (cred != NULL) {
2804                         error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
2805                         if (error)
2806                                 return (error);
2807                 }
2808
2809                 if (len == 0) { /* just remove the option */
2810                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2811                         break;
2812                 }
2813
2814                 /* check if cmsg_len is large enough for sa_len */
2815                 if (len < sizeof(struct sockaddr) || len < *buf)
2816                         return (EINVAL);
2817
2818                 switch (((struct sockaddr *)buf)->sa_family) {
2819                 case AF_INET6:
2820                 {
2821                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2822                         int error;
2823
2824                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2825                                 return (EINVAL);
2826
2827                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2828                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2829                                 return (EINVAL);
2830                         }
2831                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2832                             != 0) {
2833                                 return (error);
2834                         }
2835                         break;
2836                 }
2837                 case AF_LINK:   /* should eventually be supported */
2838                 default:
2839                         return (EAFNOSUPPORT);
2840                 }
2841
2842                 /* turn off the previous option, then set the new option. */
2843                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2844                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2845                 if (opt->ip6po_nexthop == NULL)
2846                         return (ENOBUFS);
2847                 bcopy(buf, opt->ip6po_nexthop, *buf);
2848                 break;
2849
2850         case IPV6_2292HOPOPTS:
2851         case IPV6_HOPOPTS:
2852         {
2853                 struct ip6_hbh *hbh;
2854                 int hbhlen;
2855
2856                 /*
2857                  * XXX: We don't allow a non-privileged user to set ANY HbH
2858                  * options, since per-option restriction has too much
2859                  * overhead.
2860                  */
2861                 if (cred != NULL) {
2862                         error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
2863                         if (error)
2864                                 return (error);
2865                 }
2866
2867                 if (len == 0) {
2868                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2869                         break;  /* just remove the option */
2870                 }
2871
2872                 /* message length validation */
2873                 if (len < sizeof(struct ip6_hbh))
2874                         return (EINVAL);
2875                 hbh = (struct ip6_hbh *)buf;
2876                 hbhlen = (hbh->ip6h_len + 1) << 3;
2877                 if (len != hbhlen)
2878                         return (EINVAL);
2879
2880                 /* turn off the previous option, then set the new option. */
2881                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2882                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2883                 if (opt->ip6po_hbh == NULL)
2884                         return (ENOBUFS);
2885                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2886
2887                 break;
2888         }
2889
2890         case IPV6_2292DSTOPTS:
2891         case IPV6_DSTOPTS:
2892         case IPV6_RTHDRDSTOPTS:
2893         {
2894                 struct ip6_dest *dest, **newdest = NULL;
2895                 int destlen;
2896
2897                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2898                         error = priv_check_cred(cred, PRIV_NETINET_SETHDROPTS);
2899                         if (error)
2900                                 return (error);
2901                 }
2902
2903                 if (len == 0) {
2904                         ip6_clearpktopts(opt, optname);
2905                         break;  /* just remove the option */
2906                 }
2907
2908                 /* message length validation */
2909                 if (len < sizeof(struct ip6_dest))
2910                         return (EINVAL);
2911                 dest = (struct ip6_dest *)buf;
2912                 destlen = (dest->ip6d_len + 1) << 3;
2913                 if (len != destlen)
2914                         return (EINVAL);
2915
2916                 /*
2917                  * Determine the position that the destination options header
2918                  * should be inserted; before or after the routing header.
2919                  */
2920                 switch (optname) {
2921                 case IPV6_2292DSTOPTS:
2922                         /*
2923                          * The old advacned API is ambiguous on this point.
2924                          * Our approach is to determine the position based
2925                          * according to the existence of a routing header.
2926                          * Note, however, that this depends on the order of the
2927                          * extension headers in the ancillary data; the 1st
2928                          * part of the destination options header must appear
2929                          * before the routing header in the ancillary data,
2930                          * too.
2931                          * RFC3542 solved the ambiguity by introducing
2932                          * separate ancillary data or option types.
2933                          */
2934                         if (opt->ip6po_rthdr == NULL)
2935                                 newdest = &opt->ip6po_dest1;
2936                         else
2937                                 newdest = &opt->ip6po_dest2;
2938                         break;
2939                 case IPV6_RTHDRDSTOPTS:
2940                         newdest = &opt->ip6po_dest1;
2941                         break;
2942                 case IPV6_DSTOPTS:
2943                         newdest = &opt->ip6po_dest2;
2944                         break;
2945                 }
2946
2947                 /* turn off the previous option, then set the new option. */
2948                 ip6_clearpktopts(opt, optname);
2949                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2950                 if (*newdest == NULL)
2951                         return (ENOBUFS);
2952                 bcopy(dest, *newdest, destlen);
2953
2954                 break;
2955         }
2956
2957         case IPV6_2292RTHDR:
2958         case IPV6_RTHDR:
2959         {
2960                 struct ip6_rthdr *rth;
2961                 int rthlen;
2962
2963                 if (len == 0) {
2964                         ip6_clearpktopts(opt, IPV6_RTHDR);
2965                         break;  /* just remove the option */
2966                 }
2967
2968                 /* message length validation */
2969                 if (len < sizeof(struct ip6_rthdr))
2970                         return (EINVAL);
2971                 rth = (struct ip6_rthdr *)buf;
2972                 rthlen = (rth->ip6r_len + 1) << 3;
2973                 if (len != rthlen)
2974                         return (EINVAL);
2975
2976                 switch (rth->ip6r_type) {
2977                 case IPV6_RTHDR_TYPE_0:
2978                         if (rth->ip6r_len == 0) /* must contain one addr */
2979                                 return (EINVAL);
2980                         if (rth->ip6r_len % 2) /* length must be even */
2981                                 return (EINVAL);
2982                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2983                                 return (EINVAL);
2984                         break;
2985                 default:
2986                         return (EINVAL);        /* not supported */
2987                 }
2988
2989                 /* turn off the previous option */
2990                 ip6_clearpktopts(opt, IPV6_RTHDR);
2991                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2992                 if (opt->ip6po_rthdr == NULL)
2993                         return (ENOBUFS);
2994                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2995
2996                 break;
2997         }
2998
2999         case IPV6_USE_MIN_MTU:
3000                 if (len != sizeof(int))
3001                         return (EINVAL);
3002                 minmtupolicy = *(int *)buf;
3003                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3004                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
3005                     minmtupolicy != IP6PO_MINMTU_ALL) {
3006                         return (EINVAL);
3007                 }
3008                 opt->ip6po_minmtu = minmtupolicy;
3009                 break;
3010
3011         case IPV6_DONTFRAG:
3012                 if (len != sizeof(int))
3013                         return (EINVAL);
3014
3015                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3016                         /*
3017                          * we ignore this option for TCP sockets.
3018                          * (RFC3542 leaves this case unspecified.)
3019                          */
3020                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3021                 } else
3022                         opt->ip6po_flags |= IP6PO_DONTFRAG;
3023                 break;
3024
3025         case IPV6_PREFER_TEMPADDR:
3026                 if (len != sizeof(int))
3027                         return (EINVAL);
3028                 preftemp = *(int *)buf;
3029                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3030                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3031                     preftemp != IP6PO_TEMPADDR_PREFER) {
3032                         return (EINVAL);
3033                 }
3034                 opt->ip6po_prefer_tempaddr = preftemp;
3035                 break;
3036
3037         default:
3038                 return (ENOPROTOOPT);
3039         } /* end of switch */
3040
3041         return (0);
3042 }
3043
3044 /*
3045  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3046  * packet to the input queue of a specified interface.  Note that this
3047  * calls the output routine of the loopback "driver", but with an interface
3048  * pointer that might NOT be &loif -- easier than replicating that code here.
3049  */
3050 void
3051 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
3052 {
3053         struct mbuf *copym;
3054         struct ip6_hdr *ip6;
3055
3056         copym = m_copym(m, 0, M_COPYALL, M_NOWAIT);
3057         if (copym == NULL)
3058                 return;
3059
3060         /*
3061          * Make sure to deep-copy IPv6 header portion in case the data
3062          * is in an mbuf cluster, so that we can safely override the IPv6
3063          * header portion later.
3064          */
3065         if (!M_WRITABLE(copym) ||
3066             copym->m_len < sizeof(struct ip6_hdr)) {
3067                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3068                 if (copym == NULL)
3069                         return;
3070         }
3071         ip6 = mtod(copym, struct ip6_hdr *);
3072         /*
3073          * clear embedded scope identifiers if necessary.
3074          * in6_clearscope will touch the addresses only when necessary.
3075          */
3076         in6_clearscope(&ip6->ip6_src);
3077         in6_clearscope(&ip6->ip6_dst);
3078         if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3079                 copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3080                     CSUM_PSEUDO_HDR;
3081                 copym->m_pkthdr.csum_data = 0xffff;
3082         }
3083         if_simloop(ifp, copym, AF_INET6, 0);
3084 }
3085
3086 /*
3087  * Chop IPv6 header off from the payload.
3088  */
3089 static int
3090 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3091 {
3092         struct mbuf *mh;
3093         struct ip6_hdr *ip6;
3094
3095         ip6 = mtod(m, struct ip6_hdr *);
3096         if (m->m_len > sizeof(*ip6)) {
3097                 mh = m_gethdr(M_NOWAIT, MT_DATA);
3098                 if (mh == NULL) {
3099                         m_freem(m);
3100                         return ENOBUFS;
3101                 }
3102                 m_move_pkthdr(mh, m);
3103                 M_ALIGN(mh, sizeof(*ip6));
3104                 m->m_len -= sizeof(*ip6);
3105                 m->m_data += sizeof(*ip6);
3106                 mh->m_next = m;
3107                 m = mh;
3108                 m->m_len = sizeof(*ip6);
3109                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3110         }
3111         exthdrs->ip6e_ip6 = m;
3112         return 0;
3113 }
3114
3115 /*
3116  * Compute IPv6 extension header length.
3117  */
3118 int
3119 ip6_optlen(struct inpcb *in6p)
3120 {
3121         int len;
3122
3123         if (!in6p->in6p_outputopts)
3124                 return 0;
3125
3126         len = 0;
3127 #define elen(x) \
3128     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3129
3130         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3131         if (in6p->in6p_outputopts->ip6po_rthdr)
3132                 /* dest1 is valid with rthdr only */
3133                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3134         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3135         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3136         return len;
3137 #undef elen
3138 }