sys/netinet6/ip6_output.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipfw.h"
  69 #include "opt_ipsec.h"
  70 #include "opt_sctp.h"
  71 #include "opt_route.h"
  72 #include "opt_rss.h"
  73
  74 #include <sys/param.h>
  75 #include <sys/kernel.h>
  76 #include <sys/malloc.h>
  77 #include <sys/mbuf.h>
  78 #include <sys/errno.h>
  79 #include <sys/priv.h>
  80 #include <sys/proc.h>
  81 #include <sys/protosw.h>
  82 #include <sys/socket.h>
  83 #include <sys/socketvar.h>
  84 #include <sys/syslog.h>
  85 #include <sys/ucred.h>
  86
  87 #include <machine/in_cksum.h>
  88
  89 #include <net/if.h>
  90 #include <net/if_var.h>
  91 #include <net/netisr.h>
  92 #include <net/route.h>
  93 #include <net/pfil.h>
  94 #include <net/rss_config.h>
  95 #include <net/vnet.h>
  96
  97 #include <netinet/in.h>
  98 #include <netinet/in_var.h>
  99 #include <netinet/ip_var.h>
 100 #include <netinet6/in6_fib.h>
 101 #include <netinet6/in6_var.h>
 102 #include <netinet/ip6.h>
 103 #include <netinet/icmp6.h>
 104 #include <netinet6/ip6_var.h>
 105 #include <netinet/in_pcb.h>
 106 #include <netinet/tcp_var.h>
 107 #include <netinet6/nd6.h>
 108 #include <netinet6/in6_rss.h>
 109
 110 #ifdef IPSEC
 111 #include <netipsec/ipsec.h>
 112 #include <netipsec/ipsec6.h>
 113 #include <netipsec/key.h>
 114 #include <netinet6/ip6_ipsec.h>
 115 #endif /* IPSEC */
 116 #ifdef SCTP
 117 #include <netinet/sctp.h>
 118 #include <netinet/sctp_crc32.h>
 119 #endif
 120
 121 #include <netinet6/ip6protosw.h>
 122 #include <netinet6/scope6_var.h>
 123
 124 #ifdef FLOWTABLE
 125 #include <net/flowtable.h>
 126 #endif
 127
 128 extern int in6_mcast_loop;
 129
 130 struct ip6_exthdrs {
 131         struct mbuf *ip6e_ip6;
 132         struct mbuf *ip6e_hbh;
 133         struct mbuf *ip6e_dest1;
 134         struct mbuf *ip6e_rthdr;
 135         struct mbuf *ip6e_dest2;
 136 };
 137
 138 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
 139                            struct ucred *, int);
 140 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
 141         struct socket *, struct sockopt *);
 142 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
 143 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
 144         struct ucred *, int, int, int);
 145
 146 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 147 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
 148         struct ip6_frag **);
 149 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 150 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 151 static int ip6_getpmtu(struct route_in6 *, int,
 152         struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
 153 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
 154         u_long *, int *);
 155 static int ip6_getpmtu_ctl(u_int, struct in6_addr *, u_long *);
 156 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 157
 158
 159 /*
 160  * Make an extension header from option data.  hp is the source, and
 161  * mp is the destination.
 162  */
 163 #define MAKE_EXTHDR(hp, mp)                                             \
 164     do {                                                                \
 165         if (hp) {                                                       \
 166                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 167                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 168                     ((eh)->ip6e_len + 1) << 3);                         \
 169                 if (error)                                              \
 170                         goto freehdrs;                                  \
 171         }                                                               \
 172     } while (/*CONSTCOND*/ 0)
 173
 174 /*
 175  * Form a chain of extension headers.
 176  * m is the extension header mbuf
 177  * mp is the previous mbuf in the chain
 178  * p is the next header
 179  * i is the type of option.
 180  */
 181 #define MAKE_CHAIN(m, mp, p, i)\
 182     do {\
 183         if (m) {\
 184                 if (!hdrsplit) \
 185                         panic("assumption failed: hdr not split"); \
 186                 *mtod((m), u_char *) = *(p);\
 187                 *(p) = (i);\
 188                 p = mtod((m), u_char *);\
 189                 (m)->m_next = (mp)->m_next;\
 190                 (mp)->m_next = (m);\
 191                 (mp) = (m);\
 192         }\
 193     } while (/*CONSTCOND*/ 0)
 194
 195 void
 196 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
 197 {
 198         u_short csum;
 199
 200         csum = in_cksum_skip(m, offset + plen, offset);
 201         if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
 202                 csum = 0xffff;
 203         offset += m->m_pkthdr.csum_data;        /* checksum offset */
 204
 205         if (offset + sizeof(u_short) > m->m_len) {
 206                 printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
 207                     "csum_flags=%b\n", __func__, m->m_len, plen, offset,
 208                     (int)m->m_pkthdr.csum_flags, CSUM_BITS);
 209                 /*
 210                  * XXX this should not happen, but if it does, the correct
 211                  * behavior may be to insert the checksum in the appropriate
 212                  * next mbuf in the chain.
 213                  */
 214                 return;
 215         }
 216         *(u_short *)(m->m_data + offset) = csum;
 217 }
 218
 219 int
 220 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
 221     int mtu, uint32_t id)
 222 {
 223         struct mbuf *m, **mnext, *m_frgpart;
 224         struct ip6_hdr *ip6, *mhip6;
 225         struct ip6_frag *ip6f;
 226         int off;
 227         int error;
 228         int tlen = m0->m_pkthdr.len;
 229
 230         m = m0;
 231         ip6 = mtod(m, struct ip6_hdr *);
 232         mnext = &m->m_nextpkt;
 233
 234         for (off = hlen; off < tlen; off += mtu) {
 235                 m = m_gethdr(M_NOWAIT, MT_DATA);
 236                 if (!m) {
 237                         IP6STAT_INC(ip6s_odropped);
 238                         return (ENOBUFS);
 239                 }
 240                 m->m_flags = m0->m_flags & M_COPYFLAGS;
 241                 *mnext = m;
 242                 mnext = &m->m_nextpkt;
 243                 m->m_data += max_linkhdr;
 244                 mhip6 = mtod(m, struct ip6_hdr *);
 245                 *mhip6 = *ip6;
 246                 m->m_len = sizeof(*mhip6);
 247                 error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
 248                 if (error) {
 249                         IP6STAT_INC(ip6s_odropped);
 250                         return (error);
 251                 }
 252                 ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
 253                 if (off + mtu >= tlen)
 254                         mtu = tlen - off;
 255                 else
 256                         ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
 257                 mhip6->ip6_plen = htons((u_short)(mtu + hlen +
 258                     sizeof(*ip6f) - sizeof(struct ip6_hdr)));
 259                 if ((m_frgpart = m_copy(m0, off, mtu)) == 0) {
 260                         IP6STAT_INC(ip6s_odropped);
 261                         return (ENOBUFS);
 262                 }
 263                 m_cat(m, m_frgpart);
 264                 m->m_pkthdr.len = mtu + hlen + sizeof(*ip6f);
 265                 m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
 266                 m->m_pkthdr.rcvif = NULL;
 267                 ip6f->ip6f_reserved = 0;
 268                 ip6f->ip6f_ident = id;
 269                 ip6f->ip6f_nxt = nextproto;
 270                 IP6STAT_INC(ip6s_ofragments);
 271                 in6_ifstat_inc(ifp, ifs6_out_fragcreat);
 272         }
 273
 274         return (0);
 275 }
 276
 277 /*
 278  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 279  * header (with pri, len, nxt, hlim, src, dst).
 280  * This function may modify ver and hlim only.
 281  * The mbuf chain containing the packet will be freed.
 282  * The mbuf opt, if present, will not be freed.
 283  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
 284  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
 285  * then result of route lookup is stored in ro->ro_rt.
 286  *
 287  * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
 288  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 289  * which is rt_mtu.
 290  *
 291  * ifpp - XXX: just for statistics
 292  */
 293 /*
 294  * XXX TODO: no flowid is assigned for outbound flows?
 295  */
 296 int
 297 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 298     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 299     struct ifnet **ifpp, struct inpcb *inp)
 300 {
 301         struct ip6_hdr *ip6;
 302         struct ifnet *ifp, *origifp;
 303         struct mbuf *m = m0;
 304         struct mbuf *mprev = NULL;
 305         int hlen, tlen, len;
 306         struct route_in6 ip6route;
 307         struct rtentry *rt = NULL;
 308         struct sockaddr_in6 *dst, src_sa, dst_sa;
 309         struct in6_addr odst;
 310         int error = 0;
 311         struct in6_ifaddr *ia = NULL;
 312         u_long mtu;
 313         int alwaysfrag, dontfrag;
 314         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 315         struct ip6_exthdrs exthdrs;
 316         struct in6_addr finaldst, src0, dst0;
 317         u_int32_t zone;
 318         struct route_in6 *ro_pmtu = NULL;
 319         int hdrsplit = 0;
 320         int sw_csum, tso;
 321         int needfiblookup;
 322         uint32_t fibnum;
 323         struct m_tag *fwd_tag = NULL;
 324         uint32_t id;
 325
 326         ip6 = mtod(m, struct ip6_hdr *);
 327         if (ip6 == NULL) {
 328                 printf ("ip6 is NULL");
 329                 goto bad;
 330         }
 331
 332         if (inp != NULL) {
 333                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
 334                 if ((flags & IP_NODEFAULTFLOWID) == 0) {
 335                         /* unconditionally set flowid */
 336                         m->m_pkthdr.flowid = inp->inp_flowid;
 337                         M_HASHTYPE_SET(m, inp->inp_flowtype);
 338                 }
 339         }
 340
 341         finaldst = ip6->ip6_dst;
 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 #ifdef IPSEC
 367         /*
 368          * IPSec checking which handles several cases.
 369          * FAST IPSEC: We re-injected the packet.
 370          * XXX: need scope argument.
 371          */
 372         switch(ip6_ipsec_output(&m, inp, &error))
 373         {
 374         case 1:                 /* Bad packet */
 375                 goto freehdrs;
 376         case -1:                /* IPSec done */
 377                 goto done;
 378         case 0:                 /* No IPSec */
 379         default:
 380                 break;
 381         }
 382 #endif /* IPSEC */
 383
 384         /*
 385          * Calculate the total length of the extension header chain.
 386          * Keep the length of the unfragmentable part for fragmentation.
 387          */
 388         optlen = 0;
 389         if (exthdrs.ip6e_hbh)
 390                 optlen += exthdrs.ip6e_hbh->m_len;
 391         if (exthdrs.ip6e_dest1)
 392                 optlen += exthdrs.ip6e_dest1->m_len;
 393         if (exthdrs.ip6e_rthdr)
 394                 optlen += exthdrs.ip6e_rthdr->m_len;
 395         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 396
 397         /* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
 398         if (exthdrs.ip6e_dest2)
 399                 optlen += exthdrs.ip6e_dest2->m_len;
 400
 401         /*
 402          * If there is at least one extension header,
 403          * separate IP6 header from the payload.
 404          */
 405         if (optlen && !hdrsplit) {
 406                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 407                         m = NULL;
 408                         goto freehdrs;
 409                 }
 410                 m = exthdrs.ip6e_ip6;
 411                 hdrsplit++;
 412         }
 413
 414         /* adjust pointer */
 415         ip6 = mtod(m, struct ip6_hdr *);
 416
 417         /* adjust mbuf packet header length */
 418         m->m_pkthdr.len += optlen;
 419         plen = m->m_pkthdr.len - sizeof(*ip6);
 420
 421         /* If this is a jumbo payload, insert a jumbo payload option. */
 422         if (plen > IPV6_MAXPACKET) {
 423                 if (!hdrsplit) {
 424                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 425                                 m = NULL;
 426                                 goto freehdrs;
 427                         }
 428                         m = exthdrs.ip6e_ip6;
 429                         hdrsplit++;
 430                 }
 431                 /* adjust pointer */
 432                 ip6 = mtod(m, struct ip6_hdr *);
 433                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 434                         goto freehdrs;
 435                 ip6->ip6_plen = 0;
 436         } else
 437                 ip6->ip6_plen = htons(plen);
 438
 439         /*
 440          * Concatenate headers and fill in next header fields.
 441          * Here we have, on "m"
 442          *      IPv6 payload
 443          * and we insert headers accordingly.  Finally, we should be getting:
 444          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 445          *
 446          * during the header composing process, "m" points to IPv6 header.
 447          * "mprev" points to an extension header prior to esp.
 448          */
 449         u_char *nexthdrp = &ip6->ip6_nxt;
 450         mprev = m;
 451
 452         /*
 453          * we treat dest2 specially.  this makes IPsec processing
 454          * much easier.  the goal here is to make mprev point the
 455          * mbuf prior to dest2.
 456          *
 457          * result: IPv6 dest2 payload
 458          * m and mprev will point to IPv6 header.
 459          */
 460         if (exthdrs.ip6e_dest2) {
 461                 if (!hdrsplit)
 462                         panic("assumption failed: hdr not split");
 463                 exthdrs.ip6e_dest2->m_next = m->m_next;
 464                 m->m_next = exthdrs.ip6e_dest2;
 465                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 466                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 467         }
 468
 469         /*
 470          * result: IPv6 hbh dest1 rthdr dest2 payload
 471          * m will point to IPv6 header.  mprev will point to the
 472          * extension header prior to dest2 (rthdr in the above case).
 473          */
 474         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 475         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 476                    IPPROTO_DSTOPTS);
 477         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 478                    IPPROTO_ROUTING);
 479
 480         /*
 481          * If there is a routing header, discard the packet.
 482          */
 483         if (exthdrs.ip6e_rthdr) {
 484                  error = EINVAL;
 485                  goto bad;
 486         }
 487
 488         /* Source address validation */
 489         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 490             (flags & IPV6_UNSPECSRC) == 0) {
 491                 error = EOPNOTSUPP;
 492                 IP6STAT_INC(ip6s_badscope);
 493                 goto bad;
 494         }
 495         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 496                 error = EOPNOTSUPP;
 497                 IP6STAT_INC(ip6s_badscope);
 498                 goto bad;
 499         }
 500
 501         IP6STAT_INC(ip6s_localout);
 502
 503         /*
 504          * Route packet.
 505          */
 506         if (ro == 0) {
 507                 ro = &ip6route;
 508                 bzero((caddr_t)ro, sizeof(*ro));
 509         }
 510         ro_pmtu = ro;
 511         if (opt && opt->ip6po_rthdr)
 512                 ro = &opt->ip6po_route;
 513         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 514 #ifdef FLOWTABLE
 515         if (ro->ro_rt == NULL)
 516                 (void )flowtable_lookup(AF_INET6, m, (struct route *)ro);
 517 #endif
 518         fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
 519 again:
 520         /*
 521          * if specified, try to fill in the traffic class field.
 522          * do not override if a non-zero value is already set.
 523          * we check the diffserv field and the ecn field separately.
 524          */
 525         if (opt && opt->ip6po_tclass >= 0) {
 526                 int mask = 0;
 527
 528                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 529                         mask |= 0xfc;
 530                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 531                         mask |= 0x03;
 532                 if (mask != 0)
 533                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 534         }
 535
 536         /* fill in or override the hop limit field, if necessary. */
 537         if (opt && opt->ip6po_hlim != -1)
 538                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 539         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 540                 if (im6o != NULL)
 541                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 542                 else
 543                         ip6->ip6_hlim = V_ip6_defmcasthlim;
 544         }
 545
 546         /* adjust pointer */
 547         ip6 = mtod(m, struct ip6_hdr *);
 548
 549         /*
 550          * Validate route against routing table additions;
 551          * a better/more specific route might have been added.
 552          * Make sure address family is set in route.
 553          */
 554         if (inp) {
 555                 ro->ro_dst.sin6_family = AF_INET6;
 556                 RT_VALIDATE((struct route *)ro, &inp->inp_rt_cookie, fibnum);
 557         }
 558         if (ro->ro_rt && fwd_tag == NULL && (ro->ro_rt->rt_flags & RTF_UP) &&
 559             ro->ro_dst.sin6_family == AF_INET6 &&
 560             IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)) {
 561                 rt = ro->ro_rt;
 562                 ifp = ro->ro_rt->rt_ifp;
 563         } else {
 564                 if (fwd_tag == NULL) {
 565                         bzero(&dst_sa, sizeof(dst_sa));
 566                         dst_sa.sin6_family = AF_INET6;
 567                         dst_sa.sin6_len = sizeof(dst_sa);
 568                         dst_sa.sin6_addr = ip6->ip6_dst;
 569                 }
 570                 error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
 571                     &rt, fibnum);
 572                 if (error != 0) {
 573                         if (ifp != NULL)
 574                                 in6_ifstat_inc(ifp, ifs6_out_discard);
 575                         goto bad;
 576                 }
 577         }
 578         if (rt == NULL) {
 579                 /*
 580                  * If in6_selectroute() does not return a route entry,
 581                  * dst may not have been updated.
 582                  */
 583                 *dst = dst_sa;  /* XXX */
 584         }
 585
 586         /*
 587          * then rt (for unicast) and ifp must be non-NULL valid values.
 588          */
 589         if ((flags & IPV6_FORWARDING) == 0) {
 590                 /* XXX: the FORWARDING flag can be set for mrouting. */
 591                 in6_ifstat_inc(ifp, ifs6_out_request);
 592         }
 593         if (rt != NULL) {
 594                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 595                 counter_u64_add(rt->rt_pksent, 1);
 596         }
 597
 598
 599         /*
 600          * The outgoing interface must be in the zone of source and
 601          * destination addresses.
 602          */
 603         origifp = ifp;
 604
 605         src0 = ip6->ip6_src;
 606         if (in6_setscope(&src0, origifp, &zone))
 607                 goto badscope;
 608         bzero(&src_sa, sizeof(src_sa));
 609         src_sa.sin6_family = AF_INET6;
 610         src_sa.sin6_len = sizeof(src_sa);
 611         src_sa.sin6_addr = ip6->ip6_src;
 612         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 613                 goto badscope;
 614
 615         dst0 = ip6->ip6_dst;
 616         if (in6_setscope(&dst0, origifp, &zone))
 617                 goto badscope;
 618         /* re-initialize to be sure */
 619         bzero(&dst_sa, sizeof(dst_sa));
 620         dst_sa.sin6_family = AF_INET6;
 621         dst_sa.sin6_len = sizeof(dst_sa);
 622         dst_sa.sin6_addr = ip6->ip6_dst;
 623         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 624                 goto badscope;
 625         }
 626
 627         /* We should use ia_ifp to support the case of
 628          * sending packets to an address of our own.
 629          */
 630         if (ia != NULL && ia->ia_ifp)
 631                 ifp = ia->ia_ifp;
 632
 633         /* scope check is done. */
 634         goto routefound;
 635
 636   badscope:
 637         IP6STAT_INC(ip6s_badscope);
 638         in6_ifstat_inc(origifp, ifs6_out_discard);
 639         if (error == 0)
 640                 error = EHOSTUNREACH; /* XXX */
 641         goto bad;
 642
 643   routefound:
 644         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 645                 if (opt && opt->ip6po_nextroute.ro_rt) {
 646                         /*
 647                          * The nexthop is explicitly specified by the
 648                          * application.  We assume the next hop is an IPv6
 649                          * address.
 650                          */
 651                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 652                 }
 653                 else if ((rt->rt_flags & RTF_GATEWAY))
 654                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 655         }
 656
 657         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 658                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 659         } else {
 660                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 661                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 662                 /*
 663                  * Confirm that the outgoing interface supports multicast.
 664                  */
 665                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 666                         IP6STAT_INC(ip6s_noroute);
 667                         in6_ifstat_inc(ifp, ifs6_out_discard);
 668                         error = ENETUNREACH;
 669                         goto bad;
 670                 }
 671                 if ((im6o == NULL && in6_mcast_loop) ||
 672                     (im6o && im6o->im6o_multicast_loop)) {
 673                         /*
 674                          * Loop back multicast datagram if not expressly
 675                          * forbidden to do so, even if we have not joined
 676                          * the address; protocols will filter it later,
 677                          * thus deferring a hash lookup and lock acquisition
 678                          * at the expense of an m_copym().
 679                          */
 680                         ip6_mloopback(ifp, m);
 681                 } else {
 682                         /*
 683                          * If we are acting as a multicast router, perform
 684                          * multicast forwarding as if the packet had just
 685                          * arrived on the interface to which we are about
 686                          * to send.  The multicast forwarding function
 687                          * recursively calls this function, using the
 688                          * IPV6_FORWARDING flag to prevent infinite recursion.
 689                          *
 690                          * Multicasts that are looped back by ip6_mloopback(),
 691                          * above, will be forwarded by the ip6_input() routine,
 692                          * if necessary.
 693                          */
 694                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 695                                 /*
 696                                  * XXX: ip6_mforward expects that rcvif is NULL
 697                                  * when it is called from the originating path.
 698                                  * However, it may not always be the case.
 699                                  */
 700                                 m->m_pkthdr.rcvif = NULL;
 701                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 702                                         m_freem(m);
 703                                         goto done;
 704                                 }
 705                         }
 706                 }
 707                 /*
 708                  * Multicasts with a hoplimit of zero may be looped back,
 709                  * above, but must not be transmitted on a network.
 710                  * Also, multicasts addressed to the loopback interface
 711                  * are not sent -- the above call to ip6_mloopback() will
 712                  * loop back a copy if this host actually belongs to the
 713                  * destination group on the loopback interface.
 714                  */
 715                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 716                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 717                         m_freem(m);
 718                         goto done;
 719                 }
 720         }
 721
 722         /*
 723          * Fill the outgoing inteface to tell the upper layer
 724          * to increment per-interface statistics.
 725          */
 726         if (ifpp)
 727                 *ifpp = ifp;
 728
 729         /* Determine path MTU. */
 730         if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &finaldst, &mtu,
 731             &alwaysfrag, fibnum)) != 0)
 732                 goto bad;
 733
 734         /*
 735          * The caller of this function may specify to use the minimum MTU
 736          * in some cases.
 737          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 738          * setting.  The logic is a bit complicated; by default, unicast
 739          * packets will follow path MTU while multicast packets will be sent at
 740          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 741          * including unicast ones will be sent at the minimum MTU.  Multicast
 742          * packets will always be sent at the minimum MTU unless
 743          * IP6PO_MINMTU_DISABLE is explicitly specified.
 744          * See RFC 3542 for more details.
 745          */
 746         if (mtu > IPV6_MMTU) {
 747                 if ((flags & IPV6_MINMTU))
 748                         mtu = IPV6_MMTU;
 749                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 750                         mtu = IPV6_MMTU;
 751                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 752                          (opt == NULL ||
 753                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 754                         mtu = IPV6_MMTU;
 755                 }
 756         }
 757
 758         /*
 759          * clear embedded scope identifiers if necessary.
 760          * in6_clearscope will touch the addresses only when necessary.
 761          */
 762         in6_clearscope(&ip6->ip6_src);
 763         in6_clearscope(&ip6->ip6_dst);
 764
 765         /*
 766          * If the outgoing packet contains a hop-by-hop options header,
 767          * it must be examined and processed even by the source node.
 768          * (RFC 2460, section 4.)
 769          */
 770         if (exthdrs.ip6e_hbh) {
 771                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 772                 u_int32_t dummy; /* XXX unused */
 773                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 774
 775 #ifdef DIAGNOSTIC
 776                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 777                         panic("ip6e_hbh is not contiguous");
 778 #endif
 779                 /*
 780                  *  XXX: if we have to send an ICMPv6 error to the sender,
 781                  *       we need the M_LOOP flag since icmp6_error() expects
 782                  *       the IPv6 and the hop-by-hop options header are
 783                  *       contiguous unless the flag is set.
 784                  */
 785                 m->m_flags |= M_LOOP;
 786                 m->m_pkthdr.rcvif = ifp;
 787                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 788                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 789                     &dummy, &plen) < 0) {
 790                         /* m was already freed at this point */
 791                         error = EINVAL;/* better error? */
 792                         goto done;
 793                 }
 794                 m->m_flags &= ~M_LOOP; /* XXX */
 795                 m->m_pkthdr.rcvif = NULL;
 796         }
 797
 798         /* Jump over all PFIL processing if hooks are not active. */
 799         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
 800                 goto passout;
 801
 802         odst = ip6->ip6_dst;
 803         /* Run through list of hooks for output packets. */
 804         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 805         if (error != 0 || m == NULL)
 806                 goto done;
 807         ip6 = mtod(m, struct ip6_hdr *);
 808
 809         needfiblookup = 0;
 810         /* See if destination IP address was changed by packet filter. */
 811         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 812                 m->m_flags |= M_SKIP_FIREWALL;
 813                 /* If destination is now ourself drop to ip6_input(). */
 814                 if (in6_localip(&ip6->ip6_dst)) {
 815                         m->m_flags |= M_FASTFWD_OURS;
 816                         if (m->m_pkthdr.rcvif == NULL)
 817                                 m->m_pkthdr.rcvif = V_loif;
 818                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 819                                 m->m_pkthdr.csum_flags |=
 820                                     CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 821                                 m->m_pkthdr.csum_data = 0xffff;
 822                         }
 823 #ifdef SCTP
 824                         if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 825                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 826 #endif
 827                         error = netisr_queue(NETISR_IPV6, m);
 828                         goto done;
 829                 } else
 830                         needfiblookup = 1; /* Redo the routing table lookup. */
 831         }
 832         /* See if fib was changed by packet filter. */
 833         if (fibnum != M_GETFIB(m)) {
 834                 m->m_flags |= M_SKIP_FIREWALL;
 835                 fibnum = M_GETFIB(m);
 836                 RO_RTFREE(ro);
 837                 needfiblookup = 1;
 838         }
 839         if (needfiblookup)
 840                 goto again;
 841
 842         /* See if local, if yes, send it to netisr. */
 843         if (m->m_flags & M_FASTFWD_OURS) {
 844                 if (m->m_pkthdr.rcvif == NULL)
 845                         m->m_pkthdr.rcvif = V_loif;
 846                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 847                         m->m_pkthdr.csum_flags |=
 848                             CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 849                         m->m_pkthdr.csum_data = 0xffff;
 850                 }
 851 #ifdef SCTP
 852                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 853                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 854 #endif
 855                 error = netisr_queue(NETISR_IPV6, m);
 856                 goto done;
 857         }
 858         /* Or forward to some other address? */
 859         if ((m->m_flags & M_IP6_NEXTHOP) &&
 860             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 861                 dst = (struct sockaddr_in6 *)&ro->ro_dst;
 862                 bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
 863                 m->m_flags |= M_SKIP_FIREWALL;
 864                 m->m_flags &= ~M_IP6_NEXTHOP;
 865                 m_tag_delete(m, fwd_tag);
 866                 goto again;
 867         }
 868
 869 passout:
 870         /*
 871          * Send the packet to the outgoing interface.
 872          * If necessary, do IPv6 fragmentation before sending.
 873          *
 874          * the logic here is rather complex:
 875          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 876          * 1-a: send as is if tlen <= path mtu
 877          * 1-b: fragment if tlen > path mtu
 878          *
 879          * 2: if user asks us not to fragment (dontfrag == 1)
 880          * 2-a: send as is if tlen <= interface mtu
 881          * 2-b: error if tlen > interface mtu
 882          *
 883          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 884          *      always fragment
 885          *
 886          * 4: if dontfrag == 1 && alwaysfrag == 1
 887          *      error, as we cannot handle this conflicting request
 888          */
 889         sw_csum = m->m_pkthdr.csum_flags;
 890         if (!hdrsplit) {
 891                 tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
 892                 sw_csum &= ~ifp->if_hwassist;
 893         } else
 894                 tso = 0;
 895         /*
 896          * If we added extension headers, we will not do TSO and calculate the
 897          * checksums ourselves for now.
 898          * XXX-BZ  Need a framework to know when the NIC can handle it, even
 899          * with ext. hdrs.
 900          */
 901         if (sw_csum & CSUM_DELAY_DATA_IPV6) {
 902                 sw_csum &= ~CSUM_DELAY_DATA_IPV6;
 903                 in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
 904         }
 905 #ifdef SCTP
 906         if (sw_csum & CSUM_SCTP_IPV6) {
 907                 sw_csum &= ~CSUM_SCTP_IPV6;
 908                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 909         }
 910 #endif
 911         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
 912         tlen = m->m_pkthdr.len;
 913
 914         if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
 915                 dontfrag = 1;
 916         else
 917                 dontfrag = 0;
 918         if (dontfrag && alwaysfrag) {   /* case 4 */
 919                 /* conflicting request - can't transmit */
 920                 error = EMSGSIZE;
 921                 goto bad;
 922         }
 923         if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {      /* case 2-b */
 924                 /*
 925                  * Even if the DONTFRAG option is specified, we cannot send the
 926                  * packet when the data length is larger than the MTU of the
 927                  * outgoing interface.
 928                  * Notify the error by sending IPV6_PATHMTU ancillary data if
 929                  * application wanted to know the MTU value. Also return an
 930                  * error code (this is not described in the API spec).
 931                  */
 932                 if (inp != NULL)
 933                         ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
 934                 error = EMSGSIZE;
 935                 goto bad;
 936         }
 937
 938         /*
 939          * transmit packet without fragmentation
 940          */
 941         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 942                 struct in6_ifaddr *ia6;
 943
 944                 ip6 = mtod(m, struct ip6_hdr *);
 945                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 946                 if (ia6) {
 947                         /* Record statistics for this interface address. */
 948                         counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
 949                         counter_u64_add(ia6->ia_ifa.ifa_obytes,
 950                             m->m_pkthdr.len);
 951                         ifa_free(&ia6->ia_ifa);
 952                 }
 953                 error = nd6_output_ifp(ifp, origifp, m, dst,
 954                     (struct route *)ro);
 955                 goto done;
 956         }
 957
 958         /*
 959          * try to fragment the packet.  case 1-b and 3
 960          */
 961         if (mtu < IPV6_MMTU) {
 962                 /* path MTU cannot be less than IPV6_MMTU */
 963                 error = EMSGSIZE;
 964                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 965                 goto bad;
 966         } else if (ip6->ip6_plen == 0) {
 967                 /* jumbo payload cannot be fragmented */
 968                 error = EMSGSIZE;
 969                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 970                 goto bad;
 971         } else {
 972                 u_char nextproto;
 973
 974                 /*
 975                  * Too large for the destination or interface;
 976                  * fragment if possible.
 977                  * Must be able to put at least 8 bytes per fragment.
 978                  */
 979                 hlen = unfragpartlen;
 980                 if (mtu > IPV6_MAXPACKET)
 981                         mtu = IPV6_MAXPACKET;
 982
 983                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 984                 if (len < 8) {
 985                         error = EMSGSIZE;
 986                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
 987                         goto bad;
 988                 }
 989
 990                 /*
 991                  * If the interface will not calculate checksums on
 992                  * fragmented packets, then do it here.
 993                  * XXX-BZ handle the hw offloading case.  Need flags.
 994                  */
 995                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 996                         in6_delayed_cksum(m, plen, hlen);
 997                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
 998                 }
 999 #ifdef SCTP
1000                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
1001                         sctp_delayed_cksum(m, hlen);
1002                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
1003                 }
1004 #endif
1005                 /*
1006                  * Change the next header field of the last header in the
1007                  * unfragmentable part.
1008                  */
1009                 if (exthdrs.ip6e_rthdr) {
1010                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1011                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1012                 } else if (exthdrs.ip6e_dest1) {
1013                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1014                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1015                 } else if (exthdrs.ip6e_hbh) {
1016                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1017                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1018                 } else {
1019                         nextproto = ip6->ip6_nxt;
1020                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
1021                 }
1022
1023                 /*
1024                  * Loop through length of segment after first fragment,
1025                  * make new header and copy data of each part and link onto
1026                  * chain.
1027                  */
1028                 m0 = m;
1029                 id = htonl(ip6_randomid());
1030                 if ((error = ip6_fragment(ifp, m, hlen, nextproto, len, id)))
1031                         goto sendorfree;
1032
1033                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1034         }
1035
1036         /*
1037          * Remove leading garbages.
1038          */
1039 sendorfree:
1040         m = m0->m_nextpkt;
1041         m0->m_nextpkt = 0;
1042         m_freem(m0);
1043         for (m0 = m; m; m = m0) {
1044                 m0 = m->m_nextpkt;
1045                 m->m_nextpkt = 0;
1046                 if (error == 0) {
1047                         /* Record statistics for this interface address. */
1048                         if (ia) {
1049                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1050                                 counter_u64_add(ia->ia_ifa.ifa_obytes,
1051                                     m->m_pkthdr.len);
1052                         }
1053                         error = nd6_output_ifp(ifp, origifp, m, dst,
1054                             (struct route *)ro);
1055                 } else
1056                         m_freem(m);
1057         }
1058
1059         if (error == 0)
1060                 IP6STAT_INC(ip6s_fragmented);
1061
1062 done:
1063         if (ro == &ip6route)
1064                 RO_RTFREE(ro);
1065         return (error);
1066
1067 freehdrs:
1068         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1069         m_freem(exthdrs.ip6e_dest1);
1070         m_freem(exthdrs.ip6e_rthdr);
1071         m_freem(exthdrs.ip6e_dest2);
1072         /* FALLTHROUGH */
1073 bad:
1074         if (m)
1075                 m_freem(m);
1076         goto done;
1077 }
1078
1079 static int
1080 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1081 {
1082         struct mbuf *m;
1083
1084         if (hlen > MCLBYTES)
1085                 return (ENOBUFS); /* XXX */
1086
1087         if (hlen > MLEN)
1088                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1089         else
1090                 m = m_get(M_NOWAIT, MT_DATA);
1091         if (m == NULL)
1092                 return (ENOBUFS);
1093         m->m_len = hlen;
1094         if (hdr)
1095                 bcopy(hdr, mtod(m, caddr_t), hlen);
1096
1097         *mp = m;
1098         return (0);
1099 }
1100
1101 /*
1102  * Insert jumbo payload option.
1103  */
1104 static int
1105 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1106 {
1107         struct mbuf *mopt;
1108         u_char *optbuf;
1109         u_int32_t v;
1110
1111 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1112
1113         /*
1114          * If there is no hop-by-hop options header, allocate new one.
1115          * If there is one but it doesn't have enough space to store the
1116          * jumbo payload option, allocate a cluster to store the whole options.
1117          * Otherwise, use it to store the options.
1118          */
1119         if (exthdrs->ip6e_hbh == 0) {
1120                 mopt = m_get(M_NOWAIT, MT_DATA);
1121                 if (mopt == NULL)
1122                         return (ENOBUFS);
1123                 mopt->m_len = JUMBOOPTLEN;
1124                 optbuf = mtod(mopt, u_char *);
1125                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1126                 exthdrs->ip6e_hbh = mopt;
1127         } else {
1128                 struct ip6_hbh *hbh;
1129
1130                 mopt = exthdrs->ip6e_hbh;
1131                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1132                         /*
1133                          * XXX assumption:
1134                          * - exthdrs->ip6e_hbh is not referenced from places
1135                          *   other than exthdrs.
1136                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1137                          */
1138                         int oldoptlen = mopt->m_len;
1139                         struct mbuf *n;
1140
1141                         /*
1142                          * XXX: give up if the whole (new) hbh header does
1143                          * not fit even in an mbuf cluster.
1144                          */
1145                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1146                                 return (ENOBUFS);
1147
1148                         /*
1149                          * As a consequence, we must always prepare a cluster
1150                          * at this point.
1151                          */
1152                         n = m_getcl(M_NOWAIT, MT_DATA, 0);
1153                         if (n == NULL)
1154                                 return (ENOBUFS);
1155                         n->m_len = oldoptlen + JUMBOOPTLEN;
1156                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1157                             oldoptlen);
1158                         optbuf = mtod(n, caddr_t) + oldoptlen;
1159                         m_freem(mopt);
1160                         mopt = exthdrs->ip6e_hbh = n;
1161                 } else {
1162                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1163                         mopt->m_len += JUMBOOPTLEN;
1164                 }
1165                 optbuf[0] = IP6OPT_PADN;
1166                 optbuf[1] = 1;
1167
1168                 /*
1169                  * Adjust the header length according to the pad and
1170                  * the jumbo payload option.
1171                  */
1172                 hbh = mtod(mopt, struct ip6_hbh *);
1173                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1174         }
1175
1176         /* fill in the option. */
1177         optbuf[2] = IP6OPT_JUMBO;
1178         optbuf[3] = 4;
1179         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1180         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1181
1182         /* finally, adjust the packet header length */
1183         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1184
1185         return (0);
1186 #undef JUMBOOPTLEN
1187 }
1188
1189 /*
1190  * Insert fragment header and copy unfragmentable header portions.
1191  */
1192 static int
1193 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1194     struct ip6_frag **frghdrp)
1195 {
1196         struct mbuf *n, *mlast;
1197
1198         if (hlen > sizeof(struct ip6_hdr)) {
1199                 n = m_copym(m0, sizeof(struct ip6_hdr),
1200                     hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1201                 if (n == 0)
1202                         return (ENOBUFS);
1203                 m->m_next = n;
1204         } else
1205                 n = m;
1206
1207         /* Search for the last mbuf of unfragmentable part. */
1208         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1209                 ;
1210
1211         if (M_WRITABLE(mlast) &&
1212             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1213                 /* use the trailing space of the last mbuf for the fragment hdr */
1214                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1215                     mlast->m_len);
1216                 mlast->m_len += sizeof(struct ip6_frag);
1217                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1218         } else {
1219                 /* allocate a new mbuf for the fragment header */
1220                 struct mbuf *mfrg;
1221
1222                 mfrg = m_get(M_NOWAIT, MT_DATA);
1223                 if (mfrg == NULL)
1224                         return (ENOBUFS);
1225                 mfrg->m_len = sizeof(struct ip6_frag);
1226                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1227                 mlast->m_next = mfrg;
1228         }
1229
1230         return (0);
1231 }
1232
1233 /*
1234  * Calculates IPv6 path mtu for destination @dst.
1235  * Resulting MTU is stored in @mtup.
1236  *
1237  * Returns 0 on success.
1238  */
1239 static int
1240 ip6_getpmtu_ctl(u_int fibnum, struct in6_addr *dst, u_long *mtup)
1241 {
1242         struct nhop6_extended nh6;
1243         struct in6_addr kdst;
1244         uint32_t scopeid;
1245         struct ifnet *ifp;
1246         u_long mtu;
1247         int error;
1248
1249         in6_splitscope(dst, &kdst, &scopeid);
1250         if (fib6_lookup_nh_ext(fibnum, &kdst, scopeid, NHR_REF, 0, &nh6) != 0)
1251                 return (EHOSTUNREACH);
1252
1253         ifp = nh6.nh_ifp;
1254         mtu = nh6.nh_mtu;
1255
1256         error = ip6_calcmtu(ifp, dst, mtu, mtup, NULL);
1257         fib6_free_nh_ext(fibnum, &nh6);
1258
1259         return (error);
1260 }
1261
1262 /*
1263  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1264  * and cached data in @ro_pmtu.
1265  * MTU from (successful) route lookup is saved (along with dst)
1266  * inside @ro_pmtu to avoid subsequent route lookups after packet
1267  * filter processing.
1268  *
1269  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1270  * Returns 0 on success.
1271  */
1272 static int
1273 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1274     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1275     int *alwaysfragp, u_int fibnum)
1276 {
1277         struct nhop6_basic nh6;
1278         struct in6_addr kdst;
1279         uint32_t scopeid;
1280         struct sockaddr_in6 *sa6_dst;
1281         u_long mtu;
1282
1283         mtu = 0;
1284         if (do_lookup) {
1285
1286                 /*
1287                  * Here ro_pmtu has final destination address, while
1288                  * ro might represent immediate destination.
1289                  * Use ro_pmtu destination since mtu might differ.
1290                  */
1291                 sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1292                 if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1293                         ro_pmtu->ro_mtu = 0;
1294
1295                 if (ro_pmtu->ro_mtu == 0) {
1296                         bzero(sa6_dst, sizeof(*sa6_dst));
1297                         sa6_dst->sin6_family = AF_INET6;
1298                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1299                         sa6_dst->sin6_addr = *dst;
1300
1301                         in6_splitscope(dst, &kdst, &scopeid);
1302                         if (fib6_lookup_nh_basic(fibnum, &kdst, scopeid, 0, 0,
1303                             &nh6) == 0)
1304                                 ro_pmtu->ro_mtu = nh6.nh_mtu;
1305                 }
1306
1307                 mtu = ro_pmtu->ro_mtu;
1308         }
1309
1310         if (ro_pmtu->ro_rt)
1311                 mtu = ro_pmtu->ro_rt->rt_mtu;
1312
1313         return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp));
1314 }
1315
1316 /*
1317  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1318  * hostcache data for @dst.
1319  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1320  *
1321  * Returns 0 on success.
1322  */
1323 static int
1324 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1325     u_long *mtup, int *alwaysfragp)
1326 {
1327         u_long mtu = 0;
1328         int alwaysfrag = 0;
1329         int error = 0;
1330
1331         if (rt_mtu > 0) {
1332                 u_int32_t ifmtu;
1333                 struct in_conninfo inc;
1334
1335                 bzero(&inc, sizeof(inc));
1336                 inc.inc_flags |= INC_ISIPV6;
1337                 inc.inc6_faddr = *dst;
1338
1339                 ifmtu = IN6_LINKMTU(ifp);
1340                 mtu = tcp_hc_getmtu(&inc);
1341                 if (mtu)
1342                         mtu = min(mtu, rt_mtu);
1343                 else
1344                         mtu = rt_mtu;
1345                 if (mtu == 0)
1346                         mtu = ifmtu;
1347                 else if (mtu < IPV6_MMTU) {
1348                         /*
1349                          * RFC2460 section 5, last paragraph:
1350                          * if we record ICMPv6 too big message with
1351                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1352                          * or smaller, with framgent header attached.
1353                          * (fragment header is needed regardless from the
1354                          * packet size, for translators to identify packets)
1355                          */
1356                         alwaysfrag = 1;
1357                         mtu = IPV6_MMTU;
1358                 }
1359         } else if (ifp) {
1360                 mtu = IN6_LINKMTU(ifp);
1361         } else
1362                 error = EHOSTUNREACH; /* XXX */
1363
1364         *mtup = mtu;
1365         if (alwaysfragp)
1366                 *alwaysfragp = alwaysfrag;
1367         return (error);
1368 }
1369
1370 /*
1371  * IP6 socket option processing.
1372  */
1373 int
1374 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1375 {
1376         int optdatalen, uproto;
1377         void *optdata;
1378         struct inpcb *in6p = sotoinpcb(so);
1379         int error, optval;
1380         int level, op, optname;
1381         int optlen;
1382         struct thread *td;
1383 #ifdef  RSS
1384         uint32_t rss_bucket;
1385         int retval;
1386 #endif
1387
1388         level = sopt->sopt_level;
1389         op = sopt->sopt_dir;
1390         optname = sopt->sopt_name;
1391         optlen = sopt->sopt_valsize;
1392         td = sopt->sopt_td;
1393         error = 0;
1394         optval = 0;
1395         uproto = (int)so->so_proto->pr_protocol;
1396
1397         if (level != IPPROTO_IPV6) {
1398                 error = EINVAL;
1399
1400                 if (sopt->sopt_level == SOL_SOCKET &&
1401                     sopt->sopt_dir == SOPT_SET) {
1402                         switch (sopt->sopt_name) {
1403                         case SO_REUSEADDR:
1404                                 INP_WLOCK(in6p);
1405                                 if ((so->so_options & SO_REUSEADDR) != 0)
1406                                         in6p->inp_flags2 |= INP_REUSEADDR;
1407                                 else
1408                                         in6p->inp_flags2 &= ~INP_REUSEADDR;
1409                                 INP_WUNLOCK(in6p);
1410                                 error = 0;
1411                                 break;
1412                         case SO_REUSEPORT:
1413                                 INP_WLOCK(in6p);
1414                                 if ((so->so_options & SO_REUSEPORT) != 0)
1415                                         in6p->inp_flags2 |= INP_REUSEPORT;
1416                                 else
1417                                         in6p->inp_flags2 &= ~INP_REUSEPORT;
1418                                 INP_WUNLOCK(in6p);
1419                                 error = 0;
1420                                 break;
1421                         case SO_SETFIB:
1422                                 INP_WLOCK(in6p);
1423                                 in6p->inp_inc.inc_fibnum = so->so_fibnum;
1424                                 INP_WUNLOCK(in6p);
1425                                 error = 0;
1426                                 break;
1427                         default:
1428                                 break;
1429                         }
1430                 }
1431         } else {                /* level == IPPROTO_IPV6 */
1432                 switch (op) {
1433
1434                 case SOPT_SET:
1435                         switch (optname) {
1436                         case IPV6_2292PKTOPTIONS:
1437 #ifdef IPV6_PKTOPTIONS
1438                         case IPV6_PKTOPTIONS:
1439 #endif
1440                         {
1441                                 struct mbuf *m;
1442
1443                                 error = soopt_getm(sopt, &m); /* XXX */
1444                                 if (error != 0)
1445                                         break;
1446                                 error = soopt_mcopyin(sopt, m); /* XXX */
1447                                 if (error != 0)
1448                                         break;
1449                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1450                                                     m, so, sopt);
1451                                 m_freem(m); /* XXX */
1452                                 break;
1453                         }
1454
1455                         /*
1456                          * Use of some Hop-by-Hop options or some
1457                          * Destination options, might require special
1458                          * privilege.  That is, normal applications
1459                          * (without special privilege) might be forbidden
1460                          * from setting certain options in outgoing packets,
1461                          * and might never see certain options in received
1462                          * packets. [RFC 2292 Section 6]
1463                          * KAME specific note:
1464                          *  KAME prevents non-privileged users from sending or
1465                          *  receiving ANY hbh/dst options in order to avoid
1466                          *  overhead of parsing options in the kernel.
1467                          */
1468                         case IPV6_RECVHOPOPTS:
1469                         case IPV6_RECVDSTOPTS:
1470                         case IPV6_RECVRTHDRDSTOPTS:
1471                                 if (td != NULL) {
1472                                         error = priv_check(td,
1473                                             PRIV_NETINET_SETHDROPTS);
1474                                         if (error)
1475                                                 break;
1476                                 }
1477                                 /* FALLTHROUGH */
1478                         case IPV6_UNICAST_HOPS:
1479                         case IPV6_HOPLIMIT:
1480
1481                         case IPV6_RECVPKTINFO:
1482                         case IPV6_RECVHOPLIMIT:
1483                         case IPV6_RECVRTHDR:
1484                         case IPV6_RECVPATHMTU:
1485                         case IPV6_RECVTCLASS:
1486                         case IPV6_RECVFLOWID:
1487 #ifdef  RSS
1488                         case IPV6_RECVRSSBUCKETID:
1489 #endif
1490                         case IPV6_V6ONLY:
1491                         case IPV6_AUTOFLOWLABEL:
1492                         case IPV6_BINDANY:
1493                         case IPV6_BINDMULTI:
1494 #ifdef  RSS
1495                         case IPV6_RSS_LISTEN_BUCKET:
1496 #endif
1497                                 if (optname == IPV6_BINDANY && td != NULL) {
1498                                         error = priv_check(td,
1499                                             PRIV_NETINET_BINDANY);
1500                                         if (error)
1501                                                 break;
1502                                 }
1503
1504                                 if (optlen != sizeof(int)) {
1505                                         error = EINVAL;
1506                                         break;
1507                                 }
1508                                 error = sooptcopyin(sopt, &optval,
1509                                         sizeof optval, sizeof optval);
1510                                 if (error)
1511                                         break;
1512                                 switch (optname) {
1513
1514                                 case IPV6_UNICAST_HOPS:
1515                                         if (optval < -1 || optval >= 256)
1516                                                 error = EINVAL;
1517                                         else {
1518                                                 /* -1 = kernel default */
1519                                                 in6p->in6p_hops = optval;
1520                                                 if ((in6p->inp_vflag &
1521                                                      INP_IPV4) != 0)
1522                                                         in6p->inp_ip_ttl = optval;
1523                                         }
1524                                         break;
1525 #define OPTSET(bit) \
1526 do { \
1527         INP_WLOCK(in6p); \
1528         if (optval) \
1529                 in6p->inp_flags |= (bit); \
1530         else \
1531                 in6p->inp_flags &= ~(bit); \
1532         INP_WUNLOCK(in6p); \
1533 } while (/*CONSTCOND*/ 0)
1534 #define OPTSET2292(bit) \
1535 do { \
1536         INP_WLOCK(in6p); \
1537         in6p->inp_flags |= IN6P_RFC2292; \
1538         if (optval) \
1539                 in6p->inp_flags |= (bit); \
1540         else \
1541                 in6p->inp_flags &= ~(bit); \
1542         INP_WUNLOCK(in6p); \
1543 } while (/*CONSTCOND*/ 0)
1544 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1545
1546 #define OPTSET2(bit, val) do {                                          \
1547         INP_WLOCK(in6p);                                                \
1548         if (val)                                                        \
1549                 in6p->inp_flags2 |= bit;                                \
1550         else                                                            \
1551                 in6p->inp_flags2 &= ~bit;                               \
1552         INP_WUNLOCK(in6p);                                              \
1553 } while (0)
1554 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1555
1556                                 case IPV6_RECVPKTINFO:
1557                                         /* cannot mix with RFC2292 */
1558                                         if (OPTBIT(IN6P_RFC2292)) {
1559                                                 error = EINVAL;
1560                                                 break;
1561                                         }
1562                                         OPTSET(IN6P_PKTINFO);
1563                                         break;
1564
1565                                 case IPV6_HOPLIMIT:
1566                                 {
1567                                         struct ip6_pktopts **optp;
1568
1569                                         /* cannot mix with RFC2292 */
1570                                         if (OPTBIT(IN6P_RFC2292)) {
1571                                                 error = EINVAL;
1572                                                 break;
1573                                         }
1574                                         optp = &in6p->in6p_outputopts;
1575                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1576                                             (u_char *)&optval, sizeof(optval),
1577                                             optp, (td != NULL) ? td->td_ucred :
1578                                             NULL, uproto);
1579                                         break;
1580                                 }
1581
1582                                 case IPV6_RECVHOPLIMIT:
1583                                         /* cannot mix with RFC2292 */
1584                                         if (OPTBIT(IN6P_RFC2292)) {
1585                                                 error = EINVAL;
1586                                                 break;
1587                                         }
1588                                         OPTSET(IN6P_HOPLIMIT);
1589                                         break;
1590
1591                                 case IPV6_RECVHOPOPTS:
1592                                         /* cannot mix with RFC2292 */
1593                                         if (OPTBIT(IN6P_RFC2292)) {
1594                                                 error = EINVAL;
1595                                                 break;
1596                                         }
1597                                         OPTSET(IN6P_HOPOPTS);
1598                                         break;
1599
1600                                 case IPV6_RECVDSTOPTS:
1601                                         /* cannot mix with RFC2292 */
1602                                         if (OPTBIT(IN6P_RFC2292)) {
1603                                                 error = EINVAL;
1604                                                 break;
1605                                         }
1606                                         OPTSET(IN6P_DSTOPTS);
1607                                         break;
1608
1609                                 case IPV6_RECVRTHDRDSTOPTS:
1610                                         /* cannot mix with RFC2292 */
1611                                         if (OPTBIT(IN6P_RFC2292)) {
1612                                                 error = EINVAL;
1613                                                 break;
1614                                         }
1615                                         OPTSET(IN6P_RTHDRDSTOPTS);
1616                                         break;
1617
1618                                 case IPV6_RECVRTHDR:
1619                                         /* cannot mix with RFC2292 */
1620                                         if (OPTBIT(IN6P_RFC2292)) {
1621                                                 error = EINVAL;
1622                                                 break;
1623                                         }
1624                                         OPTSET(IN6P_RTHDR);
1625                                         break;
1626
1627                                 case IPV6_RECVPATHMTU:
1628                                         /*
1629                                          * We ignore this option for TCP
1630                                          * sockets.
1631                                          * (RFC3542 leaves this case
1632                                          * unspecified.)
1633                                          */
1634                                         if (uproto != IPPROTO_TCP)
1635                                                 OPTSET(IN6P_MTU);
1636                                         break;
1637
1638                                 case IPV6_RECVFLOWID:
1639                                         OPTSET2(INP_RECVFLOWID, optval);
1640                                         break;
1641
1642 #ifdef  RSS
1643                                 case IPV6_RECVRSSBUCKETID:
1644                                         OPTSET2(INP_RECVRSSBUCKETID, optval);
1645                                         break;
1646 #endif
1647
1648                                 case IPV6_V6ONLY:
1649                                         /*
1650                                          * make setsockopt(IPV6_V6ONLY)
1651                                          * available only prior to bind(2).
1652                                          * see ipng mailing list, Jun 22 2001.
1653                                          */
1654                                         if (in6p->inp_lport ||
1655                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1656                                                 error = EINVAL;
1657                                                 break;
1658                                         }
1659                                         OPTSET(IN6P_IPV6_V6ONLY);
1660                                         if (optval)
1661                                                 in6p->inp_vflag &= ~INP_IPV4;
1662                                         else
1663                                                 in6p->inp_vflag |= INP_IPV4;
1664                                         break;
1665                                 case IPV6_RECVTCLASS:
1666                                         /* cannot mix with RFC2292 XXX */
1667                                         if (OPTBIT(IN6P_RFC2292)) {
1668                                                 error = EINVAL;
1669                                                 break;
1670                                         }
1671                                         OPTSET(IN6P_TCLASS);
1672                                         break;
1673                                 case IPV6_AUTOFLOWLABEL:
1674                                         OPTSET(IN6P_AUTOFLOWLABEL);
1675                                         break;
1676
1677                                 case IPV6_BINDANY:
1678                                         OPTSET(INP_BINDANY);
1679                                         break;
1680
1681                                 case IPV6_BINDMULTI:
1682                                         OPTSET2(INP_BINDMULTI, optval);
1683                                         break;
1684 #ifdef  RSS
1685                                 case IPV6_RSS_LISTEN_BUCKET:
1686                                         if ((optval >= 0) &&
1687                                             (optval < rss_getnumbuckets())) {
1688                                                 in6p->inp_rss_listen_bucket = optval;
1689                                                 OPTSET2(INP_RSS_BUCKET_SET, 1);
1690                                         } else {
1691                                                 error = EINVAL;
1692                                         }
1693                                         break;
1694 #endif
1695                                 }
1696                                 break;
1697
1698                         case IPV6_TCLASS:
1699                         case IPV6_DONTFRAG:
1700                         case IPV6_USE_MIN_MTU:
1701                         case IPV6_PREFER_TEMPADDR:
1702                                 if (optlen != sizeof(optval)) {
1703                                         error = EINVAL;
1704                                         break;
1705                                 }
1706                                 error = sooptcopyin(sopt, &optval,
1707                                         sizeof optval, sizeof optval);
1708                                 if (error)
1709                                         break;
1710                                 {
1711                                         struct ip6_pktopts **optp;
1712                                         optp = &in6p->in6p_outputopts;
1713                                         error = ip6_pcbopt(optname,
1714                                             (u_char *)&optval, sizeof(optval),
1715                                             optp, (td != NULL) ? td->td_ucred :
1716                                             NULL, uproto);
1717                                         break;
1718                                 }
1719
1720                         case IPV6_2292PKTINFO:
1721                         case IPV6_2292HOPLIMIT:
1722                         case IPV6_2292HOPOPTS:
1723                         case IPV6_2292DSTOPTS:
1724                         case IPV6_2292RTHDR:
1725                                 /* RFC 2292 */
1726                                 if (optlen != sizeof(int)) {
1727                                         error = EINVAL;
1728                                         break;
1729                                 }
1730                                 error = sooptcopyin(sopt, &optval,
1731                                         sizeof optval, sizeof optval);
1732                                 if (error)
1733                                         break;
1734                                 switch (optname) {
1735                                 case IPV6_2292PKTINFO:
1736                                         OPTSET2292(IN6P_PKTINFO);
1737                                         break;
1738                                 case IPV6_2292HOPLIMIT:
1739                                         OPTSET2292(IN6P_HOPLIMIT);
1740                                         break;
1741                                 case IPV6_2292HOPOPTS:
1742                                         /*
1743                                          * Check super-user privilege.
1744                                          * See comments for IPV6_RECVHOPOPTS.
1745                                          */
1746                                         if (td != NULL) {
1747                                                 error = priv_check(td,
1748                                                     PRIV_NETINET_SETHDROPTS);
1749                                                 if (error)
1750                                                         return (error);
1751                                         }
1752                                         OPTSET2292(IN6P_HOPOPTS);
1753                                         break;
1754                                 case IPV6_2292DSTOPTS:
1755                                         if (td != NULL) {
1756                                                 error = priv_check(td,
1757                                                     PRIV_NETINET_SETHDROPTS);
1758                                                 if (error)
1759                                                         return (error);
1760                                         }
1761                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1762                                         break;
1763                                 case IPV6_2292RTHDR:
1764                                         OPTSET2292(IN6P_RTHDR);
1765                                         break;
1766                                 }
1767                                 break;
1768                         case IPV6_PKTINFO:
1769                         case IPV6_HOPOPTS:
1770                         case IPV6_RTHDR:
1771                         case IPV6_DSTOPTS:
1772                         case IPV6_RTHDRDSTOPTS:
1773                         case IPV6_NEXTHOP:
1774                         {
1775                                 /* new advanced API (RFC3542) */
1776                                 u_char *optbuf;
1777                                 u_char optbuf_storage[MCLBYTES];
1778                                 int optlen;
1779                                 struct ip6_pktopts **optp;
1780
1781                                 /* cannot mix with RFC2292 */
1782                                 if (OPTBIT(IN6P_RFC2292)) {
1783                                         error = EINVAL;
1784                                         break;
1785                                 }
1786
1787                                 /*
1788                                  * We only ensure valsize is not too large
1789                                  * here.  Further validation will be done
1790                                  * later.
1791                                  */
1792                                 error = sooptcopyin(sopt, optbuf_storage,
1793                                     sizeof(optbuf_storage), 0);
1794                                 if (error)
1795                                         break;
1796                                 optlen = sopt->sopt_valsize;
1797                                 optbuf = optbuf_storage;
1798                                 optp = &in6p->in6p_outputopts;
1799                                 error = ip6_pcbopt(optname, optbuf, optlen,
1800                                     optp, (td != NULL) ? td->td_ucred : NULL,
1801                                     uproto);
1802                                 break;
1803                         }
1804 #undef OPTSET
1805
1806                         case IPV6_MULTICAST_IF:
1807                         case IPV6_MULTICAST_HOPS:
1808                         case IPV6_MULTICAST_LOOP:
1809                         case IPV6_JOIN_GROUP:
1810                         case IPV6_LEAVE_GROUP:
1811                         case IPV6_MSFILTER:
1812                         case MCAST_BLOCK_SOURCE:
1813                         case MCAST_UNBLOCK_SOURCE:
1814                         case MCAST_JOIN_GROUP:
1815                         case MCAST_LEAVE_GROUP:
1816                         case MCAST_JOIN_SOURCE_GROUP:
1817                         case MCAST_LEAVE_SOURCE_GROUP:
1818                                 error = ip6_setmoptions(in6p, sopt);
1819                                 break;
1820
1821                         case IPV6_PORTRANGE:
1822                                 error = sooptcopyin(sopt, &optval,
1823                                     sizeof optval, sizeof optval);
1824                                 if (error)
1825                                         break;
1826
1827                                 INP_WLOCK(in6p);
1828                                 switch (optval) {
1829                                 case IPV6_PORTRANGE_DEFAULT:
1830                                         in6p->inp_flags &= ~(INP_LOWPORT);
1831                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1832                                         break;
1833
1834                                 case IPV6_PORTRANGE_HIGH:
1835                                         in6p->inp_flags &= ~(INP_LOWPORT);
1836                                         in6p->inp_flags |= INP_HIGHPORT;
1837                                         break;
1838
1839                                 case IPV6_PORTRANGE_LOW:
1840                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1841                                         in6p->inp_flags |= INP_LOWPORT;
1842                                         break;
1843
1844                                 default:
1845                                         error = EINVAL;
1846                                         break;
1847                                 }
1848                                 INP_WUNLOCK(in6p);
1849                                 break;
1850
1851 #ifdef IPSEC
1852                         case IPV6_IPSEC_POLICY:
1853                         {
1854                                 caddr_t req;
1855                                 struct mbuf *m;
1856
1857                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1858                                         break;
1859                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1860                                         break;
1861                                 req = mtod(m, caddr_t);
1862                                 error = ipsec_set_policy(in6p, optname, req,
1863                                     m->m_len, (sopt->sopt_td != NULL) ?
1864                                     sopt->sopt_td->td_ucred : NULL);
1865                                 m_freem(m);
1866                                 break;
1867                         }
1868 #endif /* IPSEC */
1869
1870                         default:
1871                                 error = ENOPROTOOPT;
1872                                 break;
1873                         }
1874                         break;
1875
1876                 case SOPT_GET:
1877                         switch (optname) {
1878
1879                         case IPV6_2292PKTOPTIONS:
1880 #ifdef IPV6_PKTOPTIONS
1881                         case IPV6_PKTOPTIONS:
1882 #endif
1883                                 /*
1884                                  * RFC3542 (effectively) deprecated the
1885                                  * semantics of the 2292-style pktoptions.
1886                                  * Since it was not reliable in nature (i.e.,
1887                                  * applications had to expect the lack of some
1888                                  * information after all), it would make sense
1889                                  * to simplify this part by always returning
1890                                  * empty data.
1891                                  */
1892                                 sopt->sopt_valsize = 0;
1893                                 break;
1894
1895                         case IPV6_RECVHOPOPTS:
1896                         case IPV6_RECVDSTOPTS:
1897                         case IPV6_RECVRTHDRDSTOPTS:
1898                         case IPV6_UNICAST_HOPS:
1899                         case IPV6_RECVPKTINFO:
1900                         case IPV6_RECVHOPLIMIT:
1901                         case IPV6_RECVRTHDR:
1902                         case IPV6_RECVPATHMTU:
1903
1904                         case IPV6_V6ONLY:
1905                         case IPV6_PORTRANGE:
1906                         case IPV6_RECVTCLASS:
1907                         case IPV6_AUTOFLOWLABEL:
1908                         case IPV6_BINDANY:
1909                         case IPV6_FLOWID:
1910                         case IPV6_FLOWTYPE:
1911                         case IPV6_RECVFLOWID:
1912 #ifdef  RSS
1913                         case IPV6_RSSBUCKETID:
1914                         case IPV6_RECVRSSBUCKETID:
1915 #endif
1916                         case IPV6_BINDMULTI:
1917                                 switch (optname) {
1918
1919                                 case IPV6_RECVHOPOPTS:
1920                                         optval = OPTBIT(IN6P_HOPOPTS);
1921                                         break;
1922
1923                                 case IPV6_RECVDSTOPTS:
1924                                         optval = OPTBIT(IN6P_DSTOPTS);
1925                                         break;
1926
1927                                 case IPV6_RECVRTHDRDSTOPTS:
1928                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1929                                         break;
1930
1931                                 case IPV6_UNICAST_HOPS:
1932                                         optval = in6p->in6p_hops;
1933                                         break;
1934
1935                                 case IPV6_RECVPKTINFO:
1936                                         optval = OPTBIT(IN6P_PKTINFO);
1937                                         break;
1938
1939                                 case IPV6_RECVHOPLIMIT:
1940                                         optval = OPTBIT(IN6P_HOPLIMIT);
1941                                         break;
1942
1943                                 case IPV6_RECVRTHDR:
1944                                         optval = OPTBIT(IN6P_RTHDR);
1945                                         break;
1946
1947                                 case IPV6_RECVPATHMTU:
1948                                         optval = OPTBIT(IN6P_MTU);
1949                                         break;
1950
1951                                 case IPV6_V6ONLY:
1952                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1953                                         break;
1954
1955                                 case IPV6_PORTRANGE:
1956                                     {
1957                                         int flags;
1958                                         flags = in6p->inp_flags;
1959                                         if (flags & INP_HIGHPORT)
1960                                                 optval = IPV6_PORTRANGE_HIGH;
1961                                         else if (flags & INP_LOWPORT)
1962                                                 optval = IPV6_PORTRANGE_LOW;
1963                                         else
1964                                                 optval = 0;
1965                                         break;
1966                                     }
1967                                 case IPV6_RECVTCLASS:
1968                                         optval = OPTBIT(IN6P_TCLASS);
1969                                         break;
1970
1971                                 case IPV6_AUTOFLOWLABEL:
1972                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1973                                         break;
1974
1975                                 case IPV6_BINDANY:
1976                                         optval = OPTBIT(INP_BINDANY);
1977                                         break;
1978
1979                                 case IPV6_FLOWID:
1980                                         optval = in6p->inp_flowid;
1981                                         break;
1982
1983                                 case IPV6_FLOWTYPE:
1984                                         optval = in6p->inp_flowtype;
1985                                         break;
1986
1987                                 case IPV6_RECVFLOWID:
1988                                         optval = OPTBIT2(INP_RECVFLOWID);
1989                                         break;
1990 #ifdef  RSS
1991                                 case IPV6_RSSBUCKETID:
1992                                         retval =
1993                                             rss_hash2bucket(in6p->inp_flowid,
1994                                             in6p->inp_flowtype,
1995                                             &rss_bucket);
1996                                         if (retval == 0)
1997                                                 optval = rss_bucket;
1998                                         else
1999                                                 error = EINVAL;
2000                                         break;
2001
2002                                 case IPV6_RECVRSSBUCKETID:
2003                                         optval = OPTBIT2(INP_RECVRSSBUCKETID);
2004                                         break;
2005 #endif
2006
2007                                 case IPV6_BINDMULTI:
2008                                         optval = OPTBIT2(INP_BINDMULTI);
2009                                         break;
2010
2011                                 }
2012                                 if (error)
2013                                         break;
2014                                 error = sooptcopyout(sopt, &optval,
2015                                         sizeof optval);
2016                                 break;
2017
2018                         case IPV6_PATHMTU:
2019                         {
2020                                 u_long pmtu = 0;
2021                                 struct ip6_mtuinfo mtuinfo;
2022
2023                                 if (!(so->so_state & SS_ISCONNECTED))
2024                                         return (ENOTCONN);
2025                                 /*
2026                                  * XXX: we dot not consider the case of source
2027                                  * routing, or optional information to specify
2028                                  * the outgoing interface.
2029                                  */
2030                                 error = ip6_getpmtu_ctl(so->so_fibnum,
2031                                     &in6p->in6p_faddr, &pmtu);
2032                                 if (error)
2033                                         break;
2034                                 if (pmtu > IPV6_MAXPACKET)
2035                                         pmtu = IPV6_MAXPACKET;
2036
2037                                 bzero(&mtuinfo, sizeof(mtuinfo));
2038                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2039                                 optdata = (void *)&mtuinfo;
2040                                 optdatalen = sizeof(mtuinfo);
2041                                 error = sooptcopyout(sopt, optdata,
2042                                     optdatalen);
2043                                 break;
2044                         }
2045
2046                         case IPV6_2292PKTINFO:
2047                         case IPV6_2292HOPLIMIT:
2048                         case IPV6_2292HOPOPTS:
2049                         case IPV6_2292RTHDR:
2050                         case IPV6_2292DSTOPTS:
2051                                 switch (optname) {
2052                                 case IPV6_2292PKTINFO:
2053                                         optval = OPTBIT(IN6P_PKTINFO);
2054                                         break;
2055                                 case IPV6_2292HOPLIMIT:
2056                                         optval = OPTBIT(IN6P_HOPLIMIT);
2057                                         break;
2058                                 case IPV6_2292HOPOPTS:
2059                                         optval = OPTBIT(IN6P_HOPOPTS);
2060                                         break;
2061                                 case IPV6_2292RTHDR:
2062                                         optval = OPTBIT(IN6P_RTHDR);
2063                                         break;
2064                                 case IPV6_2292DSTOPTS:
2065                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2066                                         break;
2067                                 }
2068                                 error = sooptcopyout(sopt, &optval,
2069                                     sizeof optval);
2070                                 break;
2071                         case IPV6_PKTINFO:
2072                         case IPV6_HOPOPTS:
2073                         case IPV6_RTHDR:
2074                         case IPV6_DSTOPTS:
2075                         case IPV6_RTHDRDSTOPTS:
2076                         case IPV6_NEXTHOP:
2077                         case IPV6_TCLASS:
2078                         case IPV6_DONTFRAG:
2079                         case IPV6_USE_MIN_MTU:
2080                         case IPV6_PREFER_TEMPADDR:
2081                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
2082                                     optname, sopt);
2083                                 break;
2084
2085                         case IPV6_MULTICAST_IF:
2086                         case IPV6_MULTICAST_HOPS:
2087                         case IPV6_MULTICAST_LOOP:
2088                         case IPV6_MSFILTER:
2089                                 error = ip6_getmoptions(in6p, sopt);
2090                                 break;
2091
2092 #ifdef IPSEC
2093                         case IPV6_IPSEC_POLICY:
2094                           {
2095                                 caddr_t req = NULL;
2096                                 size_t len = 0;
2097                                 struct mbuf *m = NULL;
2098                                 struct mbuf **mp = &m;
2099                                 size_t ovalsize = sopt->sopt_valsize;
2100                                 caddr_t oval = (caddr_t)sopt->sopt_val;
2101
2102                                 error = soopt_getm(sopt, &m); /* XXX */
2103                                 if (error != 0)
2104                                         break;
2105                                 error = soopt_mcopyin(sopt, m); /* XXX */
2106                                 if (error != 0)
2107                                         break;
2108                                 sopt->sopt_valsize = ovalsize;
2109                                 sopt->sopt_val = oval;
2110                                 if (m) {
2111                                         req = mtod(m, caddr_t);
2112                                         len = m->m_len;
2113                                 }
2114                                 error = ipsec_get_policy(in6p, req, len, mp);
2115                                 if (error == 0)
2116                                         error = soopt_mcopyout(sopt, m); /* XXX */
2117                                 if (error == 0 && m)
2118                                         m_freem(m);
2119                                 break;
2120                           }
2121 #endif /* IPSEC */
2122
2123                         default:
2124                                 error = ENOPROTOOPT;
2125                                 break;
2126                         }
2127                         break;
2128                 }
2129         }
2130         return (error);
2131 }
2132
2133 int
2134 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2135 {
2136         int error = 0, optval, optlen;
2137         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2138         struct inpcb *in6p = sotoinpcb(so);
2139         int level, op, optname;
2140
2141         level = sopt->sopt_level;
2142         op = sopt->sopt_dir;
2143         optname = sopt->sopt_name;
2144         optlen = sopt->sopt_valsize;
2145
2146         if (level != IPPROTO_IPV6) {
2147                 return (EINVAL);
2148         }
2149
2150         switch (optname) {
2151         case IPV6_CHECKSUM:
2152                 /*
2153                  * For ICMPv6 sockets, no modification allowed for checksum
2154                  * offset, permit "no change" values to help existing apps.
2155                  *
2156                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2157                  * for an ICMPv6 socket will fail."
2158                  * The current behavior does not meet RFC3542.
2159                  */
2160                 switch (op) {
2161                 case SOPT_SET:
2162                         if (optlen != sizeof(int)) {
2163                                 error = EINVAL;
2164                                 break;
2165                         }
2166                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2167                                             sizeof(optval));
2168                         if (error)
2169                                 break;
2170                         if ((optval % 2) != 0) {
2171                                 /* the API assumes even offset values */
2172                                 error = EINVAL;
2173                         } else if (so->so_proto->pr_protocol ==
2174                             IPPROTO_ICMPV6) {
2175                                 if (optval != icmp6off)
2176                                         error = EINVAL;
2177                         } else
2178                                 in6p->in6p_cksum = optval;
2179                         break;
2180
2181                 case SOPT_GET:
2182                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2183                                 optval = icmp6off;
2184                         else
2185                                 optval = in6p->in6p_cksum;
2186
2187                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2188                         break;
2189
2190                 default:
2191                         error = EINVAL;
2192                         break;
2193                 }
2194                 break;
2195
2196         default:
2197                 error = ENOPROTOOPT;
2198                 break;
2199         }
2200
2201         return (error);
2202 }
2203
2204 /*
2205  * Set up IP6 options in pcb for insertion in output packets or
2206  * specifying behavior of outgoing packets.
2207  */
2208 static int
2209 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2210     struct socket *so, struct sockopt *sopt)
2211 {
2212         struct ip6_pktopts *opt = *pktopt;
2213         int error = 0;
2214         struct thread *td = sopt->sopt_td;
2215
2216         /* turn off any old options. */
2217         if (opt) {
2218 #ifdef DIAGNOSTIC
2219                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2220                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2221                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2222                         printf("ip6_pcbopts: all specified options are cleared.\n");
2223 #endif
2224                 ip6_clearpktopts(opt, -1);
2225         } else
2226                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2227         *pktopt = NULL;
2228
2229         if (!m || m->m_len == 0) {
2230                 /*
2231                  * Only turning off any previous options, regardless of
2232                  * whether the opt is just created or given.
2233                  */
2234                 free(opt, M_IP6OPT);
2235                 return (0);
2236         }
2237
2238         /*  set options specified by user. */
2239         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2240             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2241                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2242                 free(opt, M_IP6OPT);
2243                 return (error);
2244         }
2245         *pktopt = opt;
2246         return (0);
2247 }
2248
2249 /*
2250  * initialize ip6_pktopts.  beware that there are non-zero default values in
2251  * the struct.
2252  */
2253 void
2254 ip6_initpktopts(struct ip6_pktopts *opt)
2255 {
2256
2257         bzero(opt, sizeof(*opt));
2258         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2259         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2260         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2261         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2262 }
2263
2264 static int
2265 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2266     struct ucred *cred, int uproto)
2267 {
2268         struct ip6_pktopts *opt;
2269
2270         if (*pktopt == NULL) {
2271                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2272                     M_WAITOK);
2273                 ip6_initpktopts(*pktopt);
2274         }
2275         opt = *pktopt;
2276
2277         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2278 }
2279
2280 static int
2281 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2282 {
2283         void *optdata = NULL;
2284         int optdatalen = 0;
2285         struct ip6_ext *ip6e;
2286         int error = 0;
2287         struct in6_pktinfo null_pktinfo;
2288         int deftclass = 0, on;
2289         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2290         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2291
2292         switch (optname) {
2293         case IPV6_PKTINFO:
2294                 optdata = (void *)&null_pktinfo;
2295                 if (pktopt && pktopt->ip6po_pktinfo) {
2296                         bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2297                             sizeof(null_pktinfo));
2298                         in6_clearscope(&null_pktinfo.ipi6_addr);
2299                 } else {
2300                         /* XXX: we don't have to do this every time... */
2301                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2302                 }
2303                 optdatalen = sizeof(struct in6_pktinfo);
2304                 break;
2305         case IPV6_TCLASS:
2306                 if (pktopt && pktopt->ip6po_tclass >= 0)
2307                         optdata = (void *)&pktopt->ip6po_tclass;
2308                 else
2309                         optdata = (void *)&deftclass;
2310                 optdatalen = sizeof(int);
2311                 break;
2312         case IPV6_HOPOPTS:
2313                 if (pktopt && pktopt->ip6po_hbh) {
2314                         optdata = (void *)pktopt->ip6po_hbh;
2315                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2316                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2317                 }
2318                 break;
2319         case IPV6_RTHDR:
2320                 if (pktopt && pktopt->ip6po_rthdr) {
2321                         optdata = (void *)pktopt->ip6po_rthdr;
2322                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2323                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2324                 }
2325                 break;
2326         case IPV6_RTHDRDSTOPTS:
2327                 if (pktopt && pktopt->ip6po_dest1) {
2328                         optdata = (void *)pktopt->ip6po_dest1;
2329                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2330                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2331                 }
2332                 break;
2333         case IPV6_DSTOPTS:
2334                 if (pktopt && pktopt->ip6po_dest2) {
2335                         optdata = (void *)pktopt->ip6po_dest2;
2336                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2337                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2338                 }
2339                 break;
2340         case IPV6_NEXTHOP:
2341                 if (pktopt && pktopt->ip6po_nexthop) {
2342                         optdata = (void *)pktopt->ip6po_nexthop;
2343                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2344                 }
2345                 break;
2346         case IPV6_USE_MIN_MTU:
2347                 if (pktopt)
2348                         optdata = (void *)&pktopt->ip6po_minmtu;
2349                 else
2350                         optdata = (void *)&defminmtu;
2351                 optdatalen = sizeof(int);
2352                 break;
2353         case IPV6_DONTFRAG:
2354                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2355                         on = 1;
2356                 else
2357                         on = 0;
2358                 optdata = (void *)&on;
2359                 optdatalen = sizeof(on);
2360                 break;
2361         case IPV6_PREFER_TEMPADDR:
2362                 if (pktopt)
2363                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2364                 else
2365                         optdata = (void *)&defpreftemp;
2366                 optdatalen = sizeof(int);
2367                 break;
2368         default:                /* should not happen */
2369 #ifdef DIAGNOSTIC
2370                 panic("ip6_getpcbopt: unexpected option\n");
2371 #endif
2372                 return (ENOPROTOOPT);
2373         }
2374
2375         error = sooptcopyout(sopt, optdata, optdatalen);
2376
2377         return (error);
2378 }
2379
2380 void
2381 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2382 {
2383         if (pktopt == NULL)
2384                 return;
2385
2386         if (optname == -1 || optname == IPV6_PKTINFO) {
2387                 if (pktopt->ip6po_pktinfo)
2388                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2389                 pktopt->ip6po_pktinfo = NULL;
2390         }
2391         if (optname == -1 || optname == IPV6_HOPLIMIT)
2392                 pktopt->ip6po_hlim = -1;
2393         if (optname == -1 || optname == IPV6_TCLASS)
2394                 pktopt->ip6po_tclass = -1;
2395         if (optname == -1 || optname == IPV6_NEXTHOP) {
2396                 if (pktopt->ip6po_nextroute.ro_rt) {
2397                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2398                         pktopt->ip6po_nextroute.ro_rt = NULL;
2399                 }
2400                 if (pktopt->ip6po_nexthop)
2401                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2402                 pktopt->ip6po_nexthop = NULL;
2403         }
2404         if (optname == -1 || optname == IPV6_HOPOPTS) {
2405                 if (pktopt->ip6po_hbh)
2406                         free(pktopt->ip6po_hbh, M_IP6OPT);
2407                 pktopt->ip6po_hbh = NULL;
2408         }
2409         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2410                 if (pktopt->ip6po_dest1)
2411                         free(pktopt->ip6po_dest1, M_IP6OPT);
2412                 pktopt->ip6po_dest1 = NULL;
2413         }
2414         if (optname == -1 || optname == IPV6_RTHDR) {
2415                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2416                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2417                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2418                 if (pktopt->ip6po_route.ro_rt) {
2419                         RTFREE(pktopt->ip6po_route.ro_rt);
2420                         pktopt->ip6po_route.ro_rt = NULL;
2421                 }
2422         }
2423         if (optname == -1 || optname == IPV6_DSTOPTS) {
2424                 if (pktopt->ip6po_dest2)
2425                         free(pktopt->ip6po_dest2, M_IP6OPT);
2426                 pktopt->ip6po_dest2 = NULL;
2427         }
2428 }
2429
2430 #define PKTOPT_EXTHDRCPY(type) \
2431 do {\
2432         if (src->type) {\
2433                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2434                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2435                 if (dst->type == NULL && canwait == M_NOWAIT)\
2436                         goto bad;\
2437                 bcopy(src->type, dst->type, hlen);\
2438         }\
2439 } while (/*CONSTCOND*/ 0)
2440
2441 static int
2442 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2443 {
2444         if (dst == NULL || src == NULL)  {
2445                 printf("ip6_clearpktopts: invalid argument\n");
2446                 return (EINVAL);
2447         }
2448
2449         dst->ip6po_hlim = src->ip6po_hlim;
2450         dst->ip6po_tclass = src->ip6po_tclass;
2451         dst->ip6po_flags = src->ip6po_flags;
2452         dst->ip6po_minmtu = src->ip6po_minmtu;
2453         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2454         if (src->ip6po_pktinfo) {
2455                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2456                     M_IP6OPT, canwait);
2457                 if (dst->ip6po_pktinfo == NULL)
2458                         goto bad;
2459                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2460         }
2461         if (src->ip6po_nexthop) {
2462                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2463                     M_IP6OPT, canwait);
2464                 if (dst->ip6po_nexthop == NULL)
2465                         goto bad;
2466                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2467                     src->ip6po_nexthop->sa_len);
2468         }
2469         PKTOPT_EXTHDRCPY(ip6po_hbh);
2470         PKTOPT_EXTHDRCPY(ip6po_dest1);
2471         PKTOPT_EXTHDRCPY(ip6po_dest2);
2472         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2473         return (0);
2474
2475   bad:
2476         ip6_clearpktopts(dst, -1);
2477         return (ENOBUFS);
2478 }
2479 #undef PKTOPT_EXTHDRCPY
2480
2481 struct ip6_pktopts *
2482 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2483 {
2484         int error;
2485         struct ip6_pktopts *dst;
2486
2487         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2488         if (dst == NULL)
2489                 return (NULL);
2490         ip6_initpktopts(dst);
2491
2492         if ((error = copypktopts(dst, src, canwait)) != 0) {
2493                 free(dst, M_IP6OPT);
2494                 return (NULL);
2495         }
2496
2497         return (dst);
2498 }
2499
2500 void
2501 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2502 {
2503         if (pktopt == NULL)
2504                 return;
2505
2506         ip6_clearpktopts(pktopt, -1);
2507
2508         free(pktopt, M_IP6OPT);
2509 }
2510
2511 /*
2512  * Set IPv6 outgoing packet options based on advanced API.
2513  */
2514 int
2515 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2516     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2517 {
2518         struct cmsghdr *cm = 0;
2519
2520         if (control == NULL || opt == NULL)
2521                 return (EINVAL);
2522
2523         ip6_initpktopts(opt);
2524         if (stickyopt) {
2525                 int error;
2526
2527                 /*
2528                  * If stickyopt is provided, make a local copy of the options
2529                  * for this particular packet, then override them by ancillary
2530                  * objects.
2531                  * XXX: copypktopts() does not copy the cached route to a next
2532                  * hop (if any).  This is not very good in terms of efficiency,
2533                  * but we can allow this since this option should be rarely
2534                  * used.
2535                  */
2536                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2537                         return (error);
2538         }
2539
2540         /*
2541          * XXX: Currently, we assume all the optional information is stored
2542          * in a single mbuf.
2543          */
2544         if (control->m_next)
2545                 return (EINVAL);
2546
2547         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2548             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2549                 int error;
2550
2551                 if (control->m_len < CMSG_LEN(0))
2552                         return (EINVAL);
2553
2554                 cm = mtod(control, struct cmsghdr *);
2555                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2556                         return (EINVAL);
2557                 if (cm->cmsg_level != IPPROTO_IPV6)
2558                         continue;
2559
2560                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2561                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2562                 if (error)
2563                         return (error);
2564         }
2565
2566         return (0);
2567 }
2568
2569 /*
2570  * Set a particular packet option, as a sticky option or an ancillary data
2571  * item.  "len" can be 0 only when it's a sticky option.
2572  * We have 4 cases of combination of "sticky" and "cmsg":
2573  * "sticky=0, cmsg=0": impossible
2574  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2575  * "sticky=1, cmsg=0": RFC3542 socket option
2576  * "sticky=1, cmsg=1": RFC2292 socket option
2577  */
2578 static int
2579 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2580     struct ucred *cred, int sticky, int cmsg, int uproto)
2581 {
2582         int minmtupolicy, preftemp;
2583         int error;
2584
2585         if (!sticky && !cmsg) {
2586 #ifdef DIAGNOSTIC
2587                 printf("ip6_setpktopt: impossible case\n");
2588 #endif
2589                 return (EINVAL);
2590         }
2591
2592         /*
2593          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2594          * not be specified in the context of RFC3542.  Conversely,
2595          * RFC3542 types should not be specified in the context of RFC2292.
2596          */
2597         if (!cmsg) {
2598                 switch (optname) {
2599                 case IPV6_2292PKTINFO:
2600                 case IPV6_2292HOPLIMIT:
2601                 case IPV6_2292NEXTHOP:
2602                 case IPV6_2292HOPOPTS:
2603                 case IPV6_2292DSTOPTS:
2604                 case IPV6_2292RTHDR:
2605                 case IPV6_2292PKTOPTIONS:
2606                         return (ENOPROTOOPT);
2607                 }
2608         }
2609         if (sticky && cmsg) {
2610                 switch (optname) {
2611                 case IPV6_PKTINFO:
2612                 case IPV6_HOPLIMIT:
2613                 case IPV6_NEXTHOP:
2614                 case IPV6_HOPOPTS:
2615                 case IPV6_DSTOPTS:
2616                 case IPV6_RTHDRDSTOPTS:
2617                 case IPV6_RTHDR:
2618                 case IPV6_USE_MIN_MTU:
2619                 case IPV6_DONTFRAG:
2620                 case IPV6_TCLASS:
2621                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2622                         return (ENOPROTOOPT);
2623                 }
2624         }
2625
2626         switch (optname) {
2627         case IPV6_2292PKTINFO:
2628         case IPV6_PKTINFO:
2629         {
2630                 struct ifnet *ifp = NULL;
2631                 struct in6_pktinfo *pktinfo;
2632
2633                 if (len != sizeof(struct in6_pktinfo))
2634                         return (EINVAL);
2635
2636                 pktinfo = (struct in6_pktinfo *)buf;
2637
2638                 /*
2639                  * An application can clear any sticky IPV6_PKTINFO option by
2640                  * doing a "regular" setsockopt with ipi6_addr being
2641                  * in6addr_any and ipi6_ifindex being zero.
2642                  * [RFC 3542, Section 6]
2643                  */
2644                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2645                     pktinfo->ipi6_ifindex == 0 &&
2646                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2647                         ip6_clearpktopts(opt, optname);
2648                         break;
2649                 }
2650
2651                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2652                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2653                         return (EINVAL);
2654                 }
2655                 if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2656                         return (EINVAL);
2657                 /* validate the interface index if specified. */
2658                 if (pktinfo->ipi6_ifindex > V_if_index)
2659                          return (ENXIO);
2660                 if (pktinfo->ipi6_ifindex) {
2661                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2662                         if (ifp == NULL)
2663                                 return (ENXIO);
2664                 }
2665                 if (ifp != NULL && (
2666                     ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED))
2667                         return (ENETDOWN);
2668
2669                 if (ifp != NULL &&
2670                     !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2671                         struct in6_ifaddr *ia;
2672
2673                         in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2674                         ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2675                         if (ia == NULL)
2676                                 return (EADDRNOTAVAIL);
2677                         ifa_free(&ia->ia_ifa);
2678                 }
2679                 /*
2680                  * We store the address anyway, and let in6_selectsrc()
2681                  * validate the specified address.  This is because ipi6_addr
2682                  * may not have enough information about its scope zone, and
2683                  * we may need additional information (such as outgoing
2684                  * interface or the scope zone of a destination address) to
2685                  * disambiguate the scope.
2686                  * XXX: the delay of the validation may confuse the
2687                  * application when it is used as a sticky option.
2688                  */
2689                 if (opt->ip6po_pktinfo == NULL) {
2690                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2691                             M_IP6OPT, M_NOWAIT);
2692                         if (opt->ip6po_pktinfo == NULL)
2693                                 return (ENOBUFS);
2694                 }
2695                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2696                 break;
2697         }
2698
2699         case IPV6_2292HOPLIMIT:
2700         case IPV6_HOPLIMIT:
2701         {
2702                 int *hlimp;
2703
2704                 /*
2705                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2706                  * to simplify the ordering among hoplimit options.
2707                  */
2708                 if (optname == IPV6_HOPLIMIT && sticky)
2709                         return (ENOPROTOOPT);
2710
2711                 if (len != sizeof(int))
2712                         return (EINVAL);
2713                 hlimp = (int *)buf;
2714                 if (*hlimp < -1 || *hlimp > 255)
2715                         return (EINVAL);
2716
2717                 opt->ip6po_hlim = *hlimp;
2718                 break;
2719         }
2720
2721         case IPV6_TCLASS:
2722         {
2723                 int tclass;
2724
2725                 if (len != sizeof(int))
2726                         return (EINVAL);
2727                 tclass = *(int *)buf;
2728                 if (tclass < -1 || tclass > 255)
2729                         return (EINVAL);
2730
2731                 opt->ip6po_tclass = tclass;
2732                 break;
2733         }
2734
2735         case IPV6_2292NEXTHOP:
2736         case IPV6_NEXTHOP:
2737                 if (cred != NULL) {
2738                         error = priv_check_cred(cred,
2739                             PRIV_NETINET_SETHDROPTS, 0);
2740                         if (error)
2741                                 return (error);
2742                 }
2743
2744                 if (len == 0) { /* just remove the option */
2745                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2746                         break;
2747                 }
2748
2749                 /* check if cmsg_len is large enough for sa_len */
2750                 if (len < sizeof(struct sockaddr) || len < *buf)
2751                         return (EINVAL);
2752
2753                 switch (((struct sockaddr *)buf)->sa_family) {
2754                 case AF_INET6:
2755                 {
2756                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2757                         int error;
2758
2759                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2760                                 return (EINVAL);
2761
2762                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2763                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2764                                 return (EINVAL);
2765                         }
2766                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2767                             != 0) {
2768                                 return (error);
2769                         }
2770                         break;
2771                 }
2772                 case AF_LINK:   /* should eventually be supported */
2773                 default:
2774                         return (EAFNOSUPPORT);
2775                 }
2776
2777                 /* turn off the previous option, then set the new option. */
2778                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2779                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2780                 if (opt->ip6po_nexthop == NULL)
2781                         return (ENOBUFS);
2782                 bcopy(buf, opt->ip6po_nexthop, *buf);
2783                 break;
2784
2785         case IPV6_2292HOPOPTS:
2786         case IPV6_HOPOPTS:
2787         {
2788                 struct ip6_hbh *hbh;
2789                 int hbhlen;
2790
2791                 /*
2792                  * XXX: We don't allow a non-privileged user to set ANY HbH
2793                  * options, since per-option restriction has too much
2794                  * overhead.
2795                  */
2796                 if (cred != NULL) {
2797                         error = priv_check_cred(cred,
2798                             PRIV_NETINET_SETHDROPTS, 0);
2799                         if (error)
2800                                 return (error);
2801                 }
2802
2803                 if (len == 0) {
2804                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2805                         break;  /* just remove the option */
2806                 }
2807
2808                 /* message length validation */
2809                 if (len < sizeof(struct ip6_hbh))
2810                         return (EINVAL);
2811                 hbh = (struct ip6_hbh *)buf;
2812                 hbhlen = (hbh->ip6h_len + 1) << 3;
2813                 if (len != hbhlen)
2814                         return (EINVAL);
2815
2816                 /* turn off the previous option, then set the new option. */
2817                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2818                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2819                 if (opt->ip6po_hbh == NULL)
2820                         return (ENOBUFS);
2821                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2822
2823                 break;
2824         }
2825
2826         case IPV6_2292DSTOPTS:
2827         case IPV6_DSTOPTS:
2828         case IPV6_RTHDRDSTOPTS:
2829         {
2830                 struct ip6_dest *dest, **newdest = NULL;
2831                 int destlen;
2832
2833                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2834                         error = priv_check_cred(cred,
2835                             PRIV_NETINET_SETHDROPTS, 0);
2836                         if (error)
2837                                 return (error);
2838                 }
2839
2840                 if (len == 0) {
2841                         ip6_clearpktopts(opt, optname);
2842                         break;  /* just remove the option */
2843                 }
2844
2845                 /* message length validation */
2846                 if (len < sizeof(struct ip6_dest))
2847                         return (EINVAL);
2848                 dest = (struct ip6_dest *)buf;
2849                 destlen = (dest->ip6d_len + 1) << 3;
2850                 if (len != destlen)
2851                         return (EINVAL);
2852
2853                 /*
2854                  * Determine the position that the destination options header
2855                  * should be inserted; before or after the routing header.
2856                  */
2857                 switch (optname) {
2858                 case IPV6_2292DSTOPTS:
2859                         /*
2860                          * The old advacned API is ambiguous on this point.
2861                          * Our approach is to determine the position based
2862                          * according to the existence of a routing header.
2863                          * Note, however, that this depends on the order of the
2864                          * extension headers in the ancillary data; the 1st
2865                          * part of the destination options header must appear
2866                          * before the routing header in the ancillary data,
2867                          * too.
2868                          * RFC3542 solved the ambiguity by introducing
2869                          * separate ancillary data or option types.
2870                          */
2871                         if (opt->ip6po_rthdr == NULL)
2872                                 newdest = &opt->ip6po_dest1;
2873                         else
2874                                 newdest = &opt->ip6po_dest2;
2875                         break;
2876                 case IPV6_RTHDRDSTOPTS:
2877                         newdest = &opt->ip6po_dest1;
2878                         break;
2879                 case IPV6_DSTOPTS:
2880                         newdest = &opt->ip6po_dest2;
2881                         break;
2882                 }
2883
2884                 /* turn off the previous option, then set the new option. */
2885                 ip6_clearpktopts(opt, optname);
2886                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2887                 if (*newdest == NULL)
2888                         return (ENOBUFS);
2889                 bcopy(dest, *newdest, destlen);
2890
2891                 break;
2892         }
2893
2894         case IPV6_2292RTHDR:
2895         case IPV6_RTHDR:
2896         {
2897                 struct ip6_rthdr *rth;
2898                 int rthlen;
2899
2900                 if (len == 0) {
2901                         ip6_clearpktopts(opt, IPV6_RTHDR);
2902                         break;  /* just remove the option */
2903                 }
2904
2905                 /* message length validation */
2906                 if (len < sizeof(struct ip6_rthdr))
2907                         return (EINVAL);
2908                 rth = (struct ip6_rthdr *)buf;
2909                 rthlen = (rth->ip6r_len + 1) << 3;
2910                 if (len != rthlen)
2911                         return (EINVAL);
2912
2913                 switch (rth->ip6r_type) {
2914                 case IPV6_RTHDR_TYPE_0:
2915                         if (rth->ip6r_len == 0) /* must contain one addr */
2916                                 return (EINVAL);
2917                         if (rth->ip6r_len % 2) /* length must be even */
2918                                 return (EINVAL);
2919                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2920                                 return (EINVAL);
2921                         break;
2922                 default:
2923                         return (EINVAL);        /* not supported */
2924                 }
2925
2926                 /* turn off the previous option */
2927                 ip6_clearpktopts(opt, IPV6_RTHDR);
2928                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2929                 if (opt->ip6po_rthdr == NULL)
2930                         return (ENOBUFS);
2931                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2932
2933                 break;
2934         }
2935
2936         case IPV6_USE_MIN_MTU:
2937                 if (len != sizeof(int))
2938                         return (EINVAL);
2939                 minmtupolicy = *(int *)buf;
2940                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2941                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2942                     minmtupolicy != IP6PO_MINMTU_ALL) {
2943                         return (EINVAL);
2944                 }
2945                 opt->ip6po_minmtu = minmtupolicy;
2946                 break;
2947
2948         case IPV6_DONTFRAG:
2949                 if (len != sizeof(int))
2950                         return (EINVAL);
2951
2952                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2953                         /*
2954                          * we ignore this option for TCP sockets.
2955                          * (RFC3542 leaves this case unspecified.)
2956                          */
2957                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2958                 } else
2959                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2960                 break;
2961
2962         case IPV6_PREFER_TEMPADDR:
2963                 if (len != sizeof(int))
2964                         return (EINVAL);
2965                 preftemp = *(int *)buf;
2966                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2967                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2968                     preftemp != IP6PO_TEMPADDR_PREFER) {
2969                         return (EINVAL);
2970                 }
2971                 opt->ip6po_prefer_tempaddr = preftemp;
2972                 break;
2973
2974         default:
2975                 return (ENOPROTOOPT);
2976         } /* end of switch */
2977
2978         return (0);
2979 }
2980
2981 /*
2982  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2983  * packet to the input queue of a specified interface.  Note that this
2984  * calls the output routine of the loopback "driver", but with an interface
2985  * pointer that might NOT be &loif -- easier than replicating that code here.
2986  */
2987 void
2988 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
2989 {
2990         struct mbuf *copym;
2991         struct ip6_hdr *ip6;
2992
2993         copym = m_copy(m, 0, M_COPYALL);
2994         if (copym == NULL)
2995                 return;
2996
2997         /*
2998          * Make sure to deep-copy IPv6 header portion in case the data
2999          * is in an mbuf cluster, so that we can safely override the IPv6
3000          * header portion later.
3001          */
3002         if (!M_WRITABLE(copym) ||
3003             copym->m_len < sizeof(struct ip6_hdr)) {
3004                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3005                 if (copym == NULL)
3006                         return;
3007         }
3008         ip6 = mtod(copym, struct ip6_hdr *);
3009         /*
3010          * clear embedded scope identifiers if necessary.
3011          * in6_clearscope will touch the addresses only when necessary.
3012          */
3013         in6_clearscope(&ip6->ip6_src);
3014         in6_clearscope(&ip6->ip6_dst);
3015         if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3016                 copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3017                     CSUM_PSEUDO_HDR;
3018                 copym->m_pkthdr.csum_data = 0xffff;
3019         }
3020         if_simloop(ifp, copym, AF_INET6, 0);
3021 }
3022
3023 /*
3024  * Chop IPv6 header off from the payload.
3025  */
3026 static int
3027 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3028 {
3029         struct mbuf *mh;
3030         struct ip6_hdr *ip6;
3031
3032         ip6 = mtod(m, struct ip6_hdr *);
3033         if (m->m_len > sizeof(*ip6)) {
3034                 mh = m_gethdr(M_NOWAIT, MT_DATA);
3035                 if (mh == NULL) {
3036                         m_freem(m);
3037                         return ENOBUFS;
3038                 }
3039                 m_move_pkthdr(mh, m);
3040                 M_ALIGN(mh, sizeof(*ip6));
3041                 m->m_len -= sizeof(*ip6);
3042                 m->m_data += sizeof(*ip6);
3043                 mh->m_next = m;
3044                 m = mh;
3045                 m->m_len = sizeof(*ip6);
3046                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3047         }
3048         exthdrs->ip6e_ip6 = m;
3049         return 0;
3050 }
3051
3052 /*
3053  * Compute IPv6 extension header length.
3054  */
3055 int
3056 ip6_optlen(struct inpcb *in6p)
3057 {
3058         int len;
3059
3060         if (!in6p->in6p_outputopts)
3061                 return 0;
3062
3063         len = 0;
3064 #define elen(x) \
3065     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3066
3067         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3068         if (in6p->in6p_outputopts->ip6po_rthdr)
3069                 /* dest1 is valid with rthdr only */
3070                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3071         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3072         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3073         return len;
3074 #undef elen
3075 }