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/vnet.h>
  95
  96 #include <netinet/in.h>
  97 #include <netinet/in_var.h>
  98 #include <netinet/ip_var.h>
  99 #include <netinet6/in6_var.h>
 100 #include <netinet/ip6.h>
 101 #include <netinet/icmp6.h>
 102 #include <netinet6/ip6_var.h>
 103 #include <netinet/in_pcb.h>
 104 #include <netinet/tcp_var.h>
 105 #include <netinet6/nd6.h>
 106 #include <netinet/in_rss.h>
 107
 108 #ifdef IPSEC
 109 #include <netipsec/ipsec.h>
 110 #include <netipsec/ipsec6.h>
 111 #include <netipsec/key.h>
 112 #include <netinet6/ip6_ipsec.h>
 113 #endif /* IPSEC */
 114 #ifdef SCTP
 115 #include <netinet/sctp.h>
 116 #include <netinet/sctp_crc32.h>
 117 #endif
 118
 119 #include <netinet6/ip6protosw.h>
 120 #include <netinet6/scope6_var.h>
 121
 122 #ifdef FLOWTABLE
 123 #include <net/flowtable.h>
 124 #endif
 125
 126 extern int in6_mcast_loop;
 127
 128 struct ip6_exthdrs {
 129         struct mbuf *ip6e_ip6;
 130         struct mbuf *ip6e_hbh;
 131         struct mbuf *ip6e_dest1;
 132         struct mbuf *ip6e_rthdr;
 133         struct mbuf *ip6e_dest2;
 134 };
 135
 136 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
 137                            struct ucred *, int);
 138 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
 139         struct socket *, struct sockopt *);
 140 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
 141 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
 142         struct ucred *, int, int, int);
 143
 144 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 145 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
 146         struct ip6_frag **);
 147 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 148 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 149 static int ip6_getpmtu(struct route_in6 *, struct route_in6 *,
 150         struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
 151 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 152
 153
 154 /*
 155  * Make an extension header from option data.  hp is the source, and
 156  * mp is the destination.
 157  */
 158 #define MAKE_EXTHDR(hp, mp)                                             \
 159     do {                                                                \
 160         if (hp) {                                                       \
 161                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 162                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 163                     ((eh)->ip6e_len + 1) << 3);                         \
 164                 if (error)                                              \
 165                         goto freehdrs;                                  \
 166         }                                                               \
 167     } while (/*CONSTCOND*/ 0)
 168
 169 /*
 170  * Form a chain of extension headers.
 171  * m is the extension header mbuf
 172  * mp is the previous mbuf in the chain
 173  * p is the next header
 174  * i is the type of option.
 175  */
 176 #define MAKE_CHAIN(m, mp, p, i)\
 177     do {\
 178         if (m) {\
 179                 if (!hdrsplit) \
 180                         panic("assumption failed: hdr not split"); \
 181                 *mtod((m), u_char *) = *(p);\
 182                 *(p) = (i);\
 183                 p = mtod((m), u_char *);\
 184                 (m)->m_next = (mp)->m_next;\
 185                 (mp)->m_next = (m);\
 186                 (mp) = (m);\
 187         }\
 188     } while (/*CONSTCOND*/ 0)
 189
 190 void
 191 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
 192 {
 193         u_short csum;
 194
 195         csum = in_cksum_skip(m, offset + plen, offset);
 196         if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
 197                 csum = 0xffff;
 198         offset += m->m_pkthdr.csum_data;        /* checksum offset */
 199
 200         if (offset + sizeof(u_short) > m->m_len) {
 201                 printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
 202                     "csum_flags=%b\n", __func__, m->m_len, plen, offset,
 203                     (int)m->m_pkthdr.csum_flags, CSUM_BITS);
 204                 /*
 205                  * XXX this should not happen, but if it does, the correct
 206                  * behavior may be to insert the checksum in the appropriate
 207                  * next mbuf in the chain.
 208                  */
 209                 return;
 210         }
 211         *(u_short *)(m->m_data + offset) = csum;
 212 }
 213
 214 /*
 215  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 216  * header (with pri, len, nxt, hlim, src, dst).
 217  * This function may modify ver and hlim only.
 218  * The mbuf chain containing the packet will be freed.
 219  * The mbuf opt, if present, will not be freed.
 220  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
 221  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
 222  * then result of route lookup is stored in ro->ro_rt.
 223  *
 224  * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
 225  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 226  * which is rt_mtu.
 227  *
 228  * ifpp - XXX: just for statistics
 229  */
 230 /*
 231  * XXX TODO: no flowid is assigned for outbound flows?
 232  */
 233 int
 234 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 235     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 236     struct ifnet **ifpp, struct inpcb *inp)
 237 {
 238         struct ip6_hdr *ip6, *mhip6;
 239         struct ifnet *ifp, *origifp;
 240         struct mbuf *m = m0;
 241         struct mbuf *mprev = NULL;
 242         int hlen, tlen, len, off;
 243         struct route_in6 ip6route;
 244         struct rtentry *rt = NULL;
 245         struct sockaddr_in6 *dst, src_sa, dst_sa;
 246         struct in6_addr odst;
 247         int error = 0;
 248         struct in6_ifaddr *ia = NULL;
 249         u_long mtu;
 250         int alwaysfrag, dontfrag;
 251         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 252         struct ip6_exthdrs exthdrs;
 253         struct in6_addr finaldst, src0, dst0;
 254         u_int32_t zone;
 255         struct route_in6 *ro_pmtu = NULL;
 256         int hdrsplit = 0;
 257         int sw_csum, tso;
 258         int needfiblookup;
 259         uint32_t fibnum;
 260         struct m_tag *fwd_tag = NULL;
 261
 262         ip6 = mtod(m, struct ip6_hdr *);
 263         if (ip6 == NULL) {
 264                 printf ("ip6 is NULL");
 265                 goto bad;
 266         }
 267
 268         if (inp != NULL) {
 269                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
 270                 if (((flags & IP_NODEFAULTFLOWID) == 0) &&
 271                 (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID))) {
 272                         m->m_pkthdr.flowid = inp->inp_flowid;
 273                         m->m_flags |= M_FLOWID;
 274                 }
 275         }
 276
 277         finaldst = ip6->ip6_dst;
 278         bzero(&exthdrs, sizeof(exthdrs));
 279         if (opt) {
 280                 /* Hop-by-Hop options header */
 281                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 282                 /* Destination options header(1st part) */
 283                 if (opt->ip6po_rthdr) {
 284                         /*
 285                          * Destination options header(1st part)
 286                          * This only makes sense with a routing header.
 287                          * See Section 9.2 of RFC 3542.
 288                          * Disabling this part just for MIP6 convenience is
 289                          * a bad idea.  We need to think carefully about a
 290                          * way to make the advanced API coexist with MIP6
 291                          * options, which might automatically be inserted in
 292                          * the kernel.
 293                          */
 294                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 295                 }
 296                 /* Routing header */
 297                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 298                 /* Destination options header(2nd part) */
 299                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 300         }
 301
 302 #ifdef IPSEC
 303         /*
 304          * IPSec checking which handles several cases.
 305          * FAST IPSEC: We re-injected the packet.
 306          */
 307         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp))
 308         {
 309         case 1:                 /* Bad packet */
 310                 goto freehdrs;
 311         case -1:                /* IPSec done */
 312                 goto done;
 313         case 0:                 /* No IPSec */
 314         default:
 315                 break;
 316         }
 317 #endif /* IPSEC */
 318
 319         /*
 320          * Calculate the total length of the extension header chain.
 321          * Keep the length of the unfragmentable part for fragmentation.
 322          */
 323         optlen = 0;
 324         if (exthdrs.ip6e_hbh)
 325                 optlen += exthdrs.ip6e_hbh->m_len;
 326         if (exthdrs.ip6e_dest1)
 327                 optlen += exthdrs.ip6e_dest1->m_len;
 328         if (exthdrs.ip6e_rthdr)
 329                 optlen += exthdrs.ip6e_rthdr->m_len;
 330         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 331
 332         /* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
 333         if (exthdrs.ip6e_dest2)
 334                 optlen += exthdrs.ip6e_dest2->m_len;
 335
 336         /*
 337          * If there is at least one extension header,
 338          * separate IP6 header from the payload.
 339          */
 340         if (optlen && !hdrsplit) {
 341                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 342                         m = NULL;
 343                         goto freehdrs;
 344                 }
 345                 m = exthdrs.ip6e_ip6;
 346                 hdrsplit++;
 347         }
 348
 349         /* adjust pointer */
 350         ip6 = mtod(m, struct ip6_hdr *);
 351
 352         /* adjust mbuf packet header length */
 353         m->m_pkthdr.len += optlen;
 354         plen = m->m_pkthdr.len - sizeof(*ip6);
 355
 356         /* If this is a jumbo payload, insert a jumbo payload option. */
 357         if (plen > IPV6_MAXPACKET) {
 358                 if (!hdrsplit) {
 359                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 360                                 m = NULL;
 361                                 goto freehdrs;
 362                         }
 363                         m = exthdrs.ip6e_ip6;
 364                         hdrsplit++;
 365                 }
 366                 /* adjust pointer */
 367                 ip6 = mtod(m, struct ip6_hdr *);
 368                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 369                         goto freehdrs;
 370                 ip6->ip6_plen = 0;
 371         } else
 372                 ip6->ip6_plen = htons(plen);
 373
 374         /*
 375          * Concatenate headers and fill in next header fields.
 376          * Here we have, on "m"
 377          *      IPv6 payload
 378          * and we insert headers accordingly.  Finally, we should be getting:
 379          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 380          *
 381          * during the header composing process, "m" points to IPv6 header.
 382          * "mprev" points to an extension header prior to esp.
 383          */
 384         u_char *nexthdrp = &ip6->ip6_nxt;
 385         mprev = m;
 386
 387         /*
 388          * we treat dest2 specially.  this makes IPsec processing
 389          * much easier.  the goal here is to make mprev point the
 390          * mbuf prior to dest2.
 391          *
 392          * result: IPv6 dest2 payload
 393          * m and mprev will point to IPv6 header.
 394          */
 395         if (exthdrs.ip6e_dest2) {
 396                 if (!hdrsplit)
 397                         panic("assumption failed: hdr not split");
 398                 exthdrs.ip6e_dest2->m_next = m->m_next;
 399                 m->m_next = exthdrs.ip6e_dest2;
 400                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 401                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 402         }
 403
 404         /*
 405          * result: IPv6 hbh dest1 rthdr dest2 payload
 406          * m will point to IPv6 header.  mprev will point to the
 407          * extension header prior to dest2 (rthdr in the above case).
 408          */
 409         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 410         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 411                    IPPROTO_DSTOPTS);
 412         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 413                    IPPROTO_ROUTING);
 414
 415         /*
 416          * If there is a routing header, discard the packet.
 417          */
 418         if (exthdrs.ip6e_rthdr) {
 419                  error = EINVAL;
 420                  goto bad;
 421         }
 422
 423         /* Source address validation */
 424         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 425             (flags & IPV6_UNSPECSRC) == 0) {
 426                 error = EOPNOTSUPP;
 427                 IP6STAT_INC(ip6s_badscope);
 428                 goto bad;
 429         }
 430         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 431                 error = EOPNOTSUPP;
 432                 IP6STAT_INC(ip6s_badscope);
 433                 goto bad;
 434         }
 435
 436         IP6STAT_INC(ip6s_localout);
 437
 438         /*
 439          * Route packet.
 440          */
 441         if (ro == 0) {
 442                 ro = &ip6route;
 443                 bzero((caddr_t)ro, sizeof(*ro));
 444         }
 445         ro_pmtu = ro;
 446         if (opt && opt->ip6po_rthdr)
 447                 ro = &opt->ip6po_route;
 448         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 449 #ifdef FLOWTABLE
 450         if (ro->ro_rt == NULL)
 451                 (void )flowtable_lookup(AF_INET6, m, (struct route *)ro);
 452 #endif
 453         fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
 454 again:
 455         /*
 456          * if specified, try to fill in the traffic class field.
 457          * do not override if a non-zero value is already set.
 458          * we check the diffserv field and the ecn field separately.
 459          */
 460         if (opt && opt->ip6po_tclass >= 0) {
 461                 int mask = 0;
 462
 463                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 464                         mask |= 0xfc;
 465                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 466                         mask |= 0x03;
 467                 if (mask != 0)
 468                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 469         }
 470
 471         /* fill in or override the hop limit field, if necessary. */
 472         if (opt && opt->ip6po_hlim != -1)
 473                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 474         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 475                 if (im6o != NULL)
 476                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 477                 else
 478                         ip6->ip6_hlim = V_ip6_defmcasthlim;
 479         }
 480
 481         /* adjust pointer */
 482         ip6 = mtod(m, struct ip6_hdr *);
 483
 484         if (ro->ro_rt && fwd_tag == NULL) {
 485                 rt = ro->ro_rt;
 486                 ifp = ro->ro_rt->rt_ifp;
 487         } else {
 488                 if (fwd_tag == NULL) {
 489                         bzero(&dst_sa, sizeof(dst_sa));
 490                         dst_sa.sin6_family = AF_INET6;
 491                         dst_sa.sin6_len = sizeof(dst_sa);
 492                         dst_sa.sin6_addr = ip6->ip6_dst;
 493                 }
 494                 error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
 495                     &rt, fibnum);
 496                 if (error != 0) {
 497                         if (ifp != NULL)
 498                                 in6_ifstat_inc(ifp, ifs6_out_discard);
 499                         goto bad;
 500                 }
 501         }
 502         if (rt == NULL) {
 503                 /*
 504                  * If in6_selectroute() does not return a route entry,
 505                  * dst may not have been updated.
 506                  */
 507                 *dst = dst_sa;  /* XXX */
 508         }
 509
 510         /*
 511          * then rt (for unicast) and ifp must be non-NULL valid values.
 512          */
 513         if ((flags & IPV6_FORWARDING) == 0) {
 514                 /* XXX: the FORWARDING flag can be set for mrouting. */
 515                 in6_ifstat_inc(ifp, ifs6_out_request);
 516         }
 517         if (rt != NULL) {
 518                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 519                 counter_u64_add(rt->rt_pksent, 1);
 520         }
 521
 522
 523         /*
 524          * The outgoing interface must be in the zone of source and
 525          * destination addresses.
 526          */
 527         origifp = ifp;
 528
 529         src0 = ip6->ip6_src;
 530         if (in6_setscope(&src0, origifp, &zone))
 531                 goto badscope;
 532         bzero(&src_sa, sizeof(src_sa));
 533         src_sa.sin6_family = AF_INET6;
 534         src_sa.sin6_len = sizeof(src_sa);
 535         src_sa.sin6_addr = ip6->ip6_src;
 536         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 537                 goto badscope;
 538
 539         dst0 = ip6->ip6_dst;
 540         if (in6_setscope(&dst0, origifp, &zone))
 541                 goto badscope;
 542         /* re-initialize to be sure */
 543         bzero(&dst_sa, sizeof(dst_sa));
 544         dst_sa.sin6_family = AF_INET6;
 545         dst_sa.sin6_len = sizeof(dst_sa);
 546         dst_sa.sin6_addr = ip6->ip6_dst;
 547         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 548                 goto badscope;
 549         }
 550
 551         /* We should use ia_ifp to support the case of
 552          * sending packets to an address of our own.
 553          */
 554         if (ia != NULL && ia->ia_ifp)
 555                 ifp = ia->ia_ifp;
 556
 557         /* scope check is done. */
 558         goto routefound;
 559
 560   badscope:
 561         IP6STAT_INC(ip6s_badscope);
 562         in6_ifstat_inc(origifp, ifs6_out_discard);
 563         if (error == 0)
 564                 error = EHOSTUNREACH; /* XXX */
 565         goto bad;
 566
 567   routefound:
 568         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 569                 if (opt && opt->ip6po_nextroute.ro_rt) {
 570                         /*
 571                          * The nexthop is explicitly specified by the
 572                          * application.  We assume the next hop is an IPv6
 573                          * address.
 574                          */
 575                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 576                 }
 577                 else if ((rt->rt_flags & RTF_GATEWAY))
 578                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 579         }
 580
 581         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 582                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 583         } else {
 584                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 585                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 586                 /*
 587                  * Confirm that the outgoing interface supports multicast.
 588                  */
 589                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 590                         IP6STAT_INC(ip6s_noroute);
 591                         in6_ifstat_inc(ifp, ifs6_out_discard);
 592                         error = ENETUNREACH;
 593                         goto bad;
 594                 }
 595                 if ((im6o == NULL && in6_mcast_loop) ||
 596                     (im6o && im6o->im6o_multicast_loop)) {
 597                         /*
 598                          * Loop back multicast datagram if not expressly
 599                          * forbidden to do so, even if we have not joined
 600                          * the address; protocols will filter it later,
 601                          * thus deferring a hash lookup and lock acquisition
 602                          * at the expense of an m_copym().
 603                          */
 604                         ip6_mloopback(ifp, m, dst);
 605                 } else {
 606                         /*
 607                          * If we are acting as a multicast router, perform
 608                          * multicast forwarding as if the packet had just
 609                          * arrived on the interface to which we are about
 610                          * to send.  The multicast forwarding function
 611                          * recursively calls this function, using the
 612                          * IPV6_FORWARDING flag to prevent infinite recursion.
 613                          *
 614                          * Multicasts that are looped back by ip6_mloopback(),
 615                          * above, will be forwarded by the ip6_input() routine,
 616                          * if necessary.
 617                          */
 618                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 619                                 /*
 620                                  * XXX: ip6_mforward expects that rcvif is NULL
 621                                  * when it is called from the originating path.
 622                                  * However, it may not always be the case.
 623                                  */
 624                                 m->m_pkthdr.rcvif = NULL;
 625                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 626                                         m_freem(m);
 627                                         goto done;
 628                                 }
 629                         }
 630                 }
 631                 /*
 632                  * Multicasts with a hoplimit of zero may be looped back,
 633                  * above, but must not be transmitted on a network.
 634                  * Also, multicasts addressed to the loopback interface
 635                  * are not sent -- the above call to ip6_mloopback() will
 636                  * loop back a copy if this host actually belongs to the
 637                  * destination group on the loopback interface.
 638                  */
 639                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 640                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 641                         m_freem(m);
 642                         goto done;
 643                 }
 644         }
 645
 646         /*
 647          * Fill the outgoing inteface to tell the upper layer
 648          * to increment per-interface statistics.
 649          */
 650         if (ifpp)
 651                 *ifpp = ifp;
 652
 653         /* Determine path MTU. */
 654         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
 655             &alwaysfrag, fibnum)) != 0)
 656                 goto bad;
 657
 658         /*
 659          * The caller of this function may specify to use the minimum MTU
 660          * in some cases.
 661          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 662          * setting.  The logic is a bit complicated; by default, unicast
 663          * packets will follow path MTU while multicast packets will be sent at
 664          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 665          * including unicast ones will be sent at the minimum MTU.  Multicast
 666          * packets will always be sent at the minimum MTU unless
 667          * IP6PO_MINMTU_DISABLE is explicitly specified.
 668          * See RFC 3542 for more details.
 669          */
 670         if (mtu > IPV6_MMTU) {
 671                 if ((flags & IPV6_MINMTU))
 672                         mtu = IPV6_MMTU;
 673                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 674                         mtu = IPV6_MMTU;
 675                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 676                          (opt == NULL ||
 677                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 678                         mtu = IPV6_MMTU;
 679                 }
 680         }
 681
 682         /*
 683          * clear embedded scope identifiers if necessary.
 684          * in6_clearscope will touch the addresses only when necessary.
 685          */
 686         in6_clearscope(&ip6->ip6_src);
 687         in6_clearscope(&ip6->ip6_dst);
 688
 689         /*
 690          * If the outgoing packet contains a hop-by-hop options header,
 691          * it must be examined and processed even by the source node.
 692          * (RFC 2460, section 4.)
 693          */
 694         if (exthdrs.ip6e_hbh) {
 695                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 696                 u_int32_t dummy; /* XXX unused */
 697                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 698
 699 #ifdef DIAGNOSTIC
 700                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 701                         panic("ip6e_hbh is not contiguous");
 702 #endif
 703                 /*
 704                  *  XXX: if we have to send an ICMPv6 error to the sender,
 705                  *       we need the M_LOOP flag since icmp6_error() expects
 706                  *       the IPv6 and the hop-by-hop options header are
 707                  *       contiguous unless the flag is set.
 708                  */
 709                 m->m_flags |= M_LOOP;
 710                 m->m_pkthdr.rcvif = ifp;
 711                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 712                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 713                     &dummy, &plen) < 0) {
 714                         /* m was already freed at this point */
 715                         error = EINVAL;/* better error? */
 716                         goto done;
 717                 }
 718                 m->m_flags &= ~M_LOOP; /* XXX */
 719                 m->m_pkthdr.rcvif = NULL;
 720         }
 721
 722         /* Jump over all PFIL processing if hooks are not active. */
 723         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
 724                 goto passout;
 725
 726         odst = ip6->ip6_dst;
 727         /* Run through list of hooks for output packets. */
 728         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 729         if (error != 0 || m == NULL)
 730                 goto done;
 731         ip6 = mtod(m, struct ip6_hdr *);
 732
 733         needfiblookup = 0;
 734         /* See if destination IP address was changed by packet filter. */
 735         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 736                 m->m_flags |= M_SKIP_FIREWALL;
 737                 /* If destination is now ourself drop to ip6_input(). */
 738                 if (in6_localip(&ip6->ip6_dst)) {
 739                         m->m_flags |= M_FASTFWD_OURS;
 740                         if (m->m_pkthdr.rcvif == NULL)
 741                                 m->m_pkthdr.rcvif = V_loif;
 742                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 743                                 m->m_pkthdr.csum_flags |=
 744                                     CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 745                                 m->m_pkthdr.csum_data = 0xffff;
 746                         }
 747 #ifdef SCTP
 748                         if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 749                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 750 #endif
 751                         error = netisr_queue(NETISR_IPV6, m);
 752                         goto done;
 753                 } else
 754                         needfiblookup = 1; /* Redo the routing table lookup. */
 755         }
 756         /* See if fib was changed by packet filter. */
 757         if (fibnum != M_GETFIB(m)) {
 758                 m->m_flags |= M_SKIP_FIREWALL;
 759                 fibnum = M_GETFIB(m);
 760                 RO_RTFREE(ro);
 761                 needfiblookup = 1;
 762         }
 763         if (needfiblookup)
 764                 goto again;
 765
 766         /* See if local, if yes, send it to netisr. */
 767         if (m->m_flags & M_FASTFWD_OURS) {
 768                 if (m->m_pkthdr.rcvif == NULL)
 769                         m->m_pkthdr.rcvif = V_loif;
 770                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 771                         m->m_pkthdr.csum_flags |=
 772                             CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 773                         m->m_pkthdr.csum_data = 0xffff;
 774                 }
 775 #ifdef SCTP
 776                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 777                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 778 #endif
 779                 error = netisr_queue(NETISR_IPV6, m);
 780                 goto done;
 781         }
 782         /* Or forward to some other address? */
 783         if ((m->m_flags & M_IP6_NEXTHOP) &&
 784             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 785                 dst = (struct sockaddr_in6 *)&ro->ro_dst;
 786                 bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
 787                 m->m_flags |= M_SKIP_FIREWALL;
 788                 m->m_flags &= ~M_IP6_NEXTHOP;
 789                 m_tag_delete(m, fwd_tag);
 790                 goto again;
 791         }
 792
 793 passout:
 794         /*
 795          * Send the packet to the outgoing interface.
 796          * If necessary, do IPv6 fragmentation before sending.
 797          *
 798          * the logic here is rather complex:
 799          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 800          * 1-a: send as is if tlen <= path mtu
 801          * 1-b: fragment if tlen > path mtu
 802          *
 803          * 2: if user asks us not to fragment (dontfrag == 1)
 804          * 2-a: send as is if tlen <= interface mtu
 805          * 2-b: error if tlen > interface mtu
 806          *
 807          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 808          *      always fragment
 809          *
 810          * 4: if dontfrag == 1 && alwaysfrag == 1
 811          *      error, as we cannot handle this conflicting request
 812          */
 813         sw_csum = m->m_pkthdr.csum_flags;
 814         if (!hdrsplit) {
 815                 tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
 816                 sw_csum &= ~ifp->if_hwassist;
 817         } else
 818                 tso = 0;
 819         /*
 820          * If we added extension headers, we will not do TSO and calculate the
 821          * checksums ourselves for now.
 822          * XXX-BZ  Need a framework to know when the NIC can handle it, even
 823          * with ext. hdrs.
 824          */
 825         if (sw_csum & CSUM_DELAY_DATA_IPV6) {
 826                 sw_csum &= ~CSUM_DELAY_DATA_IPV6;
 827                 in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
 828         }
 829 #ifdef SCTP
 830         if (sw_csum & CSUM_SCTP_IPV6) {
 831                 sw_csum &= ~CSUM_SCTP_IPV6;
 832                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 833         }
 834 #endif
 835         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
 836         tlen = m->m_pkthdr.len;
 837
 838         if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
 839                 dontfrag = 1;
 840         else
 841                 dontfrag = 0;
 842         if (dontfrag && alwaysfrag) {   /* case 4 */
 843                 /* conflicting request - can't transmit */
 844                 error = EMSGSIZE;
 845                 goto bad;
 846         }
 847         if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {      /* case 2-b */
 848                 /*
 849                  * Even if the DONTFRAG option is specified, we cannot send the
 850                  * packet when the data length is larger than the MTU of the
 851                  * outgoing interface.
 852                  * Notify the error by sending IPV6_PATHMTU ancillary data as
 853                  * well as returning an error code (the latter is not described
 854                  * in the API spec.)
 855                  */
 856                 u_int32_t mtu32;
 857                 struct ip6ctlparam ip6cp;
 858
 859                 mtu32 = (u_int32_t)mtu;
 860                 bzero(&ip6cp, sizeof(ip6cp));
 861                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
 862                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
 863                     (void *)&ip6cp);
 864
 865                 error = EMSGSIZE;
 866                 goto bad;
 867         }
 868
 869         /*
 870          * transmit packet without fragmentation
 871          */
 872         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 873                 struct in6_ifaddr *ia6;
 874
 875                 ip6 = mtod(m, struct ip6_hdr *);
 876                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 877                 if (ia6) {
 878                         /* Record statistics for this interface address. */
 879                         counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
 880                         counter_u64_add(ia6->ia_ifa.ifa_obytes,
 881                             m->m_pkthdr.len);
 882                         ifa_free(&ia6->ia_ifa);
 883                 }
 884                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
 885                 goto done;
 886         }
 887
 888         /*
 889          * try to fragment the packet.  case 1-b and 3
 890          */
 891         if (mtu < IPV6_MMTU) {
 892                 /* path MTU cannot be less than IPV6_MMTU */
 893                 error = EMSGSIZE;
 894                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 895                 goto bad;
 896         } else if (ip6->ip6_plen == 0) {
 897                 /* jumbo payload cannot be fragmented */
 898                 error = EMSGSIZE;
 899                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 900                 goto bad;
 901         } else {
 902                 struct mbuf **mnext, *m_frgpart;
 903                 struct ip6_frag *ip6f;
 904                 u_int32_t id = htonl(ip6_randomid());
 905                 u_char nextproto;
 906
 907                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
 908
 909                 /*
 910                  * Too large for the destination or interface;
 911                  * fragment if possible.
 912                  * Must be able to put at least 8 bytes per fragment.
 913                  */
 914                 hlen = unfragpartlen;
 915                 if (mtu > IPV6_MAXPACKET)
 916                         mtu = IPV6_MAXPACKET;
 917
 918                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 919                 if (len < 8) {
 920                         error = EMSGSIZE;
 921                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
 922                         goto bad;
 923                 }
 924
 925                 /*
 926                  * Verify that we have any chance at all of being able to queue
 927                  *      the packet or packet fragments
 928                  */
 929                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
 930                     < tlen  /* - hlen */)) {
 931                         error = ENOBUFS;
 932                         IP6STAT_INC(ip6s_odropped);
 933                         goto bad;
 934                 }
 935
 936
 937                 /*
 938                  * If the interface will not calculate checksums on
 939                  * fragmented packets, then do it here.
 940                  * XXX-BZ handle the hw offloading case.  Need flags.
 941                  */
 942                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 943                         in6_delayed_cksum(m, plen, hlen);
 944                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
 945                 }
 946 #ifdef SCTP
 947                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
 948                         sctp_delayed_cksum(m, hlen);
 949                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
 950                 }
 951 #endif
 952                 mnext = &m->m_nextpkt;
 953
 954                 /*
 955                  * Change the next header field of the last header in the
 956                  * unfragmentable part.
 957                  */
 958                 if (exthdrs.ip6e_rthdr) {
 959                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
 960                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
 961                 } else if (exthdrs.ip6e_dest1) {
 962                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
 963                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
 964                 } else if (exthdrs.ip6e_hbh) {
 965                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
 966                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
 967                 } else {
 968                         nextproto = ip6->ip6_nxt;
 969                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
 970                 }
 971
 972                 /*
 973                  * Loop through length of segment after first fragment,
 974                  * make new header and copy data of each part and link onto
 975                  * chain.
 976                  */
 977                 m0 = m;
 978                 for (off = hlen; off < tlen; off += len) {
 979                         m = m_gethdr(M_NOWAIT, MT_DATA);
 980                         if (!m) {
 981                                 error = ENOBUFS;
 982                                 IP6STAT_INC(ip6s_odropped);
 983                                 goto sendorfree;
 984                         }
 985                         m->m_flags = m0->m_flags & M_COPYFLAGS;
 986                         *mnext = m;
 987                         mnext = &m->m_nextpkt;
 988                         m->m_data += max_linkhdr;
 989                         mhip6 = mtod(m, struct ip6_hdr *);
 990                         *mhip6 = *ip6;
 991                         m->m_len = sizeof(*mhip6);
 992                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
 993                         if (error) {
 994                                 IP6STAT_INC(ip6s_odropped);
 995                                 goto sendorfree;
 996                         }
 997                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
 998                         if (off + len >= tlen)
 999                                 len = tlen - off;
1000                         else
1001                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1002                         mhip6->ip6_plen = htons((u_short)(len + hlen +
1003                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1004                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1005                                 error = ENOBUFS;
1006                                 IP6STAT_INC(ip6s_odropped);
1007                                 goto sendorfree;
1008                         }
1009                         m_cat(m, m_frgpart);
1010                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1011                         m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
1012                         m->m_pkthdr.rcvif = NULL;
1013                         ip6f->ip6f_reserved = 0;
1014                         ip6f->ip6f_ident = id;
1015                         ip6f->ip6f_nxt = nextproto;
1016                         IP6STAT_INC(ip6s_ofragments);
1017                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1018                 }
1019
1020                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1021         }
1022
1023         /*
1024          * Remove leading garbages.
1025          */
1026 sendorfree:
1027         m = m0->m_nextpkt;
1028         m0->m_nextpkt = 0;
1029         m_freem(m0);
1030         for (m0 = m; m; m = m0) {
1031                 m0 = m->m_nextpkt;
1032                 m->m_nextpkt = 0;
1033                 if (error == 0) {
1034                         /* Record statistics for this interface address. */
1035                         if (ia) {
1036                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1037                                 counter_u64_add(ia->ia_ifa.ifa_obytes,
1038                                     m->m_pkthdr.len);
1039                         }
1040                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1041                 } else
1042                         m_freem(m);
1043         }
1044
1045         if (error == 0)
1046                 IP6STAT_INC(ip6s_fragmented);
1047
1048 done:
1049         if (ro == &ip6route)
1050                 RO_RTFREE(ro);
1051         if (ro_pmtu == &ip6route)
1052                 RO_RTFREE(ro_pmtu);
1053         return (error);
1054
1055 freehdrs:
1056         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1057         m_freem(exthdrs.ip6e_dest1);
1058         m_freem(exthdrs.ip6e_rthdr);
1059         m_freem(exthdrs.ip6e_dest2);
1060         /* FALLTHROUGH */
1061 bad:
1062         if (m)
1063                 m_freem(m);
1064         goto done;
1065 }
1066
1067 static int
1068 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1069 {
1070         struct mbuf *m;
1071
1072         if (hlen > MCLBYTES)
1073                 return (ENOBUFS); /* XXX */
1074
1075         if (hlen > MLEN)
1076                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1077         else
1078                 m = m_get(M_NOWAIT, MT_DATA);
1079         if (m == NULL)
1080                 return (ENOBUFS);
1081         m->m_len = hlen;
1082         if (hdr)
1083                 bcopy(hdr, mtod(m, caddr_t), hlen);
1084
1085         *mp = m;
1086         return (0);
1087 }
1088
1089 /*
1090  * Insert jumbo payload option.
1091  */
1092 static int
1093 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1094 {
1095         struct mbuf *mopt;
1096         u_char *optbuf;
1097         u_int32_t v;
1098
1099 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1100
1101         /*
1102          * If there is no hop-by-hop options header, allocate new one.
1103          * If there is one but it doesn't have enough space to store the
1104          * jumbo payload option, allocate a cluster to store the whole options.
1105          * Otherwise, use it to store the options.
1106          */
1107         if (exthdrs->ip6e_hbh == 0) {
1108                 mopt = m_get(M_NOWAIT, MT_DATA);
1109                 if (mopt == NULL)
1110                         return (ENOBUFS);
1111                 mopt->m_len = JUMBOOPTLEN;
1112                 optbuf = mtod(mopt, u_char *);
1113                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1114                 exthdrs->ip6e_hbh = mopt;
1115         } else {
1116                 struct ip6_hbh *hbh;
1117
1118                 mopt = exthdrs->ip6e_hbh;
1119                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1120                         /*
1121                          * XXX assumption:
1122                          * - exthdrs->ip6e_hbh is not referenced from places
1123                          *   other than exthdrs.
1124                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1125                          */
1126                         int oldoptlen = mopt->m_len;
1127                         struct mbuf *n;
1128
1129                         /*
1130                          * XXX: give up if the whole (new) hbh header does
1131                          * not fit even in an mbuf cluster.
1132                          */
1133                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1134                                 return (ENOBUFS);
1135
1136                         /*
1137                          * As a consequence, we must always prepare a cluster
1138                          * at this point.
1139                          */
1140                         n = m_getcl(M_NOWAIT, MT_DATA, 0);
1141                         if (n == NULL)
1142                                 return (ENOBUFS);
1143                         n->m_len = oldoptlen + JUMBOOPTLEN;
1144                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1145                             oldoptlen);
1146                         optbuf = mtod(n, caddr_t) + oldoptlen;
1147                         m_freem(mopt);
1148                         mopt = exthdrs->ip6e_hbh = n;
1149                 } else {
1150                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1151                         mopt->m_len += JUMBOOPTLEN;
1152                 }
1153                 optbuf[0] = IP6OPT_PADN;
1154                 optbuf[1] = 1;
1155
1156                 /*
1157                  * Adjust the header length according to the pad and
1158                  * the jumbo payload option.
1159                  */
1160                 hbh = mtod(mopt, struct ip6_hbh *);
1161                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1162         }
1163
1164         /* fill in the option. */
1165         optbuf[2] = IP6OPT_JUMBO;
1166         optbuf[3] = 4;
1167         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1168         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1169
1170         /* finally, adjust the packet header length */
1171         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1172
1173         return (0);
1174 #undef JUMBOOPTLEN
1175 }
1176
1177 /*
1178  * Insert fragment header and copy unfragmentable header portions.
1179  */
1180 static int
1181 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1182     struct ip6_frag **frghdrp)
1183 {
1184         struct mbuf *n, *mlast;
1185
1186         if (hlen > sizeof(struct ip6_hdr)) {
1187                 n = m_copym(m0, sizeof(struct ip6_hdr),
1188                     hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1189                 if (n == 0)
1190                         return (ENOBUFS);
1191                 m->m_next = n;
1192         } else
1193                 n = m;
1194
1195         /* Search for the last mbuf of unfragmentable part. */
1196         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1197                 ;
1198
1199         if (M_WRITABLE(mlast) &&
1200             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1201                 /* use the trailing space of the last mbuf for the fragment hdr */
1202                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1203                     mlast->m_len);
1204                 mlast->m_len += sizeof(struct ip6_frag);
1205                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1206         } else {
1207                 /* allocate a new mbuf for the fragment header */
1208                 struct mbuf *mfrg;
1209
1210                 mfrg = m_get(M_NOWAIT, MT_DATA);
1211                 if (mfrg == NULL)
1212                         return (ENOBUFS);
1213                 mfrg->m_len = sizeof(struct ip6_frag);
1214                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1215                 mlast->m_next = mfrg;
1216         }
1217
1218         return (0);
1219 }
1220
1221 static int
1222 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1223     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1224     int *alwaysfragp, u_int fibnum)
1225 {
1226         u_int32_t mtu = 0;
1227         int alwaysfrag = 0;
1228         int error = 0;
1229
1230         if (ro_pmtu != ro) {
1231                 /* The first hop and the final destination may differ. */
1232                 struct sockaddr_in6 *sa6_dst =
1233                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1234                 if (ro_pmtu->ro_rt &&
1235                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1236                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1237                         RTFREE(ro_pmtu->ro_rt);
1238                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
1239                 }
1240                 if (ro_pmtu->ro_rt == NULL) {
1241                         bzero(sa6_dst, sizeof(*sa6_dst));
1242                         sa6_dst->sin6_family = AF_INET6;
1243                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1244                         sa6_dst->sin6_addr = *dst;
1245
1246                         in6_rtalloc(ro_pmtu, fibnum);
1247                 }
1248         }
1249         if (ro_pmtu->ro_rt) {
1250                 u_int32_t ifmtu;
1251                 struct in_conninfo inc;
1252
1253                 bzero(&inc, sizeof(inc));
1254                 inc.inc_flags |= INC_ISIPV6;
1255                 inc.inc6_faddr = *dst;
1256
1257                 if (ifp == NULL)
1258                         ifp = ro_pmtu->ro_rt->rt_ifp;
1259                 ifmtu = IN6_LINKMTU(ifp);
1260                 mtu = tcp_hc_getmtu(&inc);
1261                 if (mtu)
1262                         mtu = min(mtu, ro_pmtu->ro_rt->rt_mtu);
1263                 else
1264                         mtu = ro_pmtu->ro_rt->rt_mtu;
1265                 if (mtu == 0)
1266                         mtu = ifmtu;
1267                 else if (mtu < IPV6_MMTU) {
1268                         /*
1269                          * RFC2460 section 5, last paragraph:
1270                          * if we record ICMPv6 too big message with
1271                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1272                          * or smaller, with framgent header attached.
1273                          * (fragment header is needed regardless from the
1274                          * packet size, for translators to identify packets)
1275                          */
1276                         alwaysfrag = 1;
1277                         mtu = IPV6_MMTU;
1278                 } else if (mtu > ifmtu) {
1279                         /*
1280                          * The MTU on the route is larger than the MTU on
1281                          * the interface!  This shouldn't happen, unless the
1282                          * MTU of the interface has been changed after the
1283                          * interface was brought up.  Change the MTU in the
1284                          * route to match the interface MTU (as long as the
1285                          * field isn't locked).
1286                          */
1287                         mtu = ifmtu;
1288                         ro_pmtu->ro_rt->rt_mtu = mtu;
1289                 }
1290         } else if (ifp) {
1291                 mtu = IN6_LINKMTU(ifp);
1292         } else
1293                 error = EHOSTUNREACH; /* XXX */
1294
1295         *mtup = mtu;
1296         if (alwaysfragp)
1297                 *alwaysfragp = alwaysfrag;
1298         return (error);
1299 }
1300
1301 /*
1302  * IP6 socket option processing.
1303  */
1304 int
1305 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1306 {
1307         int optdatalen, uproto;
1308         void *optdata;
1309         struct inpcb *in6p = sotoinpcb(so);
1310         int error, optval;
1311         int level, op, optname;
1312         int optlen;
1313         struct thread *td;
1314 #ifdef  RSS
1315         uint32_t rss_bucket;
1316         int retval;
1317 #endif
1318
1319         level = sopt->sopt_level;
1320         op = sopt->sopt_dir;
1321         optname = sopt->sopt_name;
1322         optlen = sopt->sopt_valsize;
1323         td = sopt->sopt_td;
1324         error = 0;
1325         optval = 0;
1326         uproto = (int)so->so_proto->pr_protocol;
1327
1328         if (level != IPPROTO_IPV6) {
1329                 error = EINVAL;
1330
1331                 if (sopt->sopt_level == SOL_SOCKET &&
1332                     sopt->sopt_dir == SOPT_SET) {
1333                         switch (sopt->sopt_name) {
1334                         case SO_REUSEADDR:
1335                                 INP_WLOCK(in6p);
1336                                 if ((so->so_options & SO_REUSEADDR) != 0)
1337                                         in6p->inp_flags2 |= INP_REUSEADDR;
1338                                 else
1339                                         in6p->inp_flags2 &= ~INP_REUSEADDR;
1340                                 INP_WUNLOCK(in6p);
1341                                 error = 0;
1342                                 break;
1343                         case SO_REUSEPORT:
1344                                 INP_WLOCK(in6p);
1345                                 if ((so->so_options & SO_REUSEPORT) != 0)
1346                                         in6p->inp_flags2 |= INP_REUSEPORT;
1347                                 else
1348                                         in6p->inp_flags2 &= ~INP_REUSEPORT;
1349                                 INP_WUNLOCK(in6p);
1350                                 error = 0;
1351                                 break;
1352                         case SO_SETFIB:
1353                                 INP_WLOCK(in6p);
1354                                 in6p->inp_inc.inc_fibnum = so->so_fibnum;
1355                                 INP_WUNLOCK(in6p);
1356                                 error = 0;
1357                                 break;
1358                         default:
1359                                 break;
1360                         }
1361                 }
1362         } else {                /* level == IPPROTO_IPV6 */
1363                 switch (op) {
1364
1365                 case SOPT_SET:
1366                         switch (optname) {
1367                         case IPV6_2292PKTOPTIONS:
1368 #ifdef IPV6_PKTOPTIONS
1369                         case IPV6_PKTOPTIONS:
1370 #endif
1371                         {
1372                                 struct mbuf *m;
1373
1374                                 error = soopt_getm(sopt, &m); /* XXX */
1375                                 if (error != 0)
1376                                         break;
1377                                 error = soopt_mcopyin(sopt, m); /* XXX */
1378                                 if (error != 0)
1379                                         break;
1380                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1381                                                     m, so, sopt);
1382                                 m_freem(m); /* XXX */
1383                                 break;
1384                         }
1385
1386                         /*
1387                          * Use of some Hop-by-Hop options or some
1388                          * Destination options, might require special
1389                          * privilege.  That is, normal applications
1390                          * (without special privilege) might be forbidden
1391                          * from setting certain options in outgoing packets,
1392                          * and might never see certain options in received
1393                          * packets. [RFC 2292 Section 6]
1394                          * KAME specific note:
1395                          *  KAME prevents non-privileged users from sending or
1396                          *  receiving ANY hbh/dst options in order to avoid
1397                          *  overhead of parsing options in the kernel.
1398                          */
1399                         case IPV6_RECVHOPOPTS:
1400                         case IPV6_RECVDSTOPTS:
1401                         case IPV6_RECVRTHDRDSTOPTS:
1402                                 if (td != NULL) {
1403                                         error = priv_check(td,
1404                                             PRIV_NETINET_SETHDROPTS);
1405                                         if (error)
1406                                                 break;
1407                                 }
1408                                 /* FALLTHROUGH */
1409                         case IPV6_UNICAST_HOPS:
1410                         case IPV6_HOPLIMIT:
1411                         case IPV6_FAITH:
1412
1413                         case IPV6_RECVPKTINFO:
1414                         case IPV6_RECVHOPLIMIT:
1415                         case IPV6_RECVRTHDR:
1416                         case IPV6_RECVPATHMTU:
1417                         case IPV6_RECVTCLASS:
1418                         case IPV6_V6ONLY:
1419                         case IPV6_AUTOFLOWLABEL:
1420                         case IPV6_BINDANY:
1421                         case IPV6_BINDMULTI:
1422 #ifdef  RSS
1423                         case IPV6_RSS_LISTEN_BUCKET:
1424 #endif
1425                                 if (optname == IPV6_BINDANY && td != NULL) {
1426                                         error = priv_check(td,
1427                                             PRIV_NETINET_BINDANY);
1428                                         if (error)
1429                                                 break;
1430                                 }
1431
1432                                 if (optlen != sizeof(int)) {
1433                                         error = EINVAL;
1434                                         break;
1435                                 }
1436                                 error = sooptcopyin(sopt, &optval,
1437                                         sizeof optval, sizeof optval);
1438                                 if (error)
1439                                         break;
1440                                 switch (optname) {
1441
1442                                 case IPV6_UNICAST_HOPS:
1443                                         if (optval < -1 || optval >= 256)
1444                                                 error = EINVAL;
1445                                         else {
1446                                                 /* -1 = kernel default */
1447                                                 in6p->in6p_hops = optval;
1448                                                 if ((in6p->inp_vflag &
1449                                                      INP_IPV4) != 0)
1450                                                         in6p->inp_ip_ttl = optval;
1451                                         }
1452                                         break;
1453 #define OPTSET(bit) \
1454 do { \
1455         INP_WLOCK(in6p); \
1456         if (optval) \
1457                 in6p->inp_flags |= (bit); \
1458         else \
1459                 in6p->inp_flags &= ~(bit); \
1460         INP_WUNLOCK(in6p); \
1461 } while (/*CONSTCOND*/ 0)
1462 #define OPTSET2292(bit) \
1463 do { \
1464         INP_WLOCK(in6p); \
1465         in6p->inp_flags |= IN6P_RFC2292; \
1466         if (optval) \
1467                 in6p->inp_flags |= (bit); \
1468         else \
1469                 in6p->inp_flags &= ~(bit); \
1470         INP_WUNLOCK(in6p); \
1471 } while (/*CONSTCOND*/ 0)
1472 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1473
1474 #define OPTSET2(bit, val) do {                                          \
1475         INP_WLOCK(in6p);                                                \
1476         if (val)                                                        \
1477                 in6p->inp_flags2 |= bit;                                \
1478         else                                                            \
1479                 in6p->inp_flags2 &= ~bit;                               \
1480         INP_WUNLOCK(in6p);                                              \
1481 } while (0)
1482 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1483
1484                                 case IPV6_RECVPKTINFO:
1485                                         /* cannot mix with RFC2292 */
1486                                         if (OPTBIT(IN6P_RFC2292)) {
1487                                                 error = EINVAL;
1488                                                 break;
1489                                         }
1490                                         OPTSET(IN6P_PKTINFO);
1491                                         break;
1492
1493                                 case IPV6_HOPLIMIT:
1494                                 {
1495                                         struct ip6_pktopts **optp;
1496
1497                                         /* cannot mix with RFC2292 */
1498                                         if (OPTBIT(IN6P_RFC2292)) {
1499                                                 error = EINVAL;
1500                                                 break;
1501                                         }
1502                                         optp = &in6p->in6p_outputopts;
1503                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1504                                             (u_char *)&optval, sizeof(optval),
1505                                             optp, (td != NULL) ? td->td_ucred :
1506                                             NULL, uproto);
1507                                         break;
1508                                 }
1509
1510                                 case IPV6_RECVHOPLIMIT:
1511                                         /* cannot mix with RFC2292 */
1512                                         if (OPTBIT(IN6P_RFC2292)) {
1513                                                 error = EINVAL;
1514                                                 break;
1515                                         }
1516                                         OPTSET(IN6P_HOPLIMIT);
1517                                         break;
1518
1519                                 case IPV6_RECVHOPOPTS:
1520                                         /* cannot mix with RFC2292 */
1521                                         if (OPTBIT(IN6P_RFC2292)) {
1522                                                 error = EINVAL;
1523                                                 break;
1524                                         }
1525                                         OPTSET(IN6P_HOPOPTS);
1526                                         break;
1527
1528                                 case IPV6_RECVDSTOPTS:
1529                                         /* cannot mix with RFC2292 */
1530                                         if (OPTBIT(IN6P_RFC2292)) {
1531                                                 error = EINVAL;
1532                                                 break;
1533                                         }
1534                                         OPTSET(IN6P_DSTOPTS);
1535                                         break;
1536
1537                                 case IPV6_RECVRTHDRDSTOPTS:
1538                                         /* cannot mix with RFC2292 */
1539                                         if (OPTBIT(IN6P_RFC2292)) {
1540                                                 error = EINVAL;
1541                                                 break;
1542                                         }
1543                                         OPTSET(IN6P_RTHDRDSTOPTS);
1544                                         break;
1545
1546                                 case IPV6_RECVRTHDR:
1547                                         /* cannot mix with RFC2292 */
1548                                         if (OPTBIT(IN6P_RFC2292)) {
1549                                                 error = EINVAL;
1550                                                 break;
1551                                         }
1552                                         OPTSET(IN6P_RTHDR);
1553                                         break;
1554
1555                                 case IPV6_FAITH:
1556                                         OPTSET(INP_FAITH);
1557                                         break;
1558
1559                                 case IPV6_RECVPATHMTU:
1560                                         /*
1561                                          * We ignore this option for TCP
1562                                          * sockets.
1563                                          * (RFC3542 leaves this case
1564                                          * unspecified.)
1565                                          */
1566                                         if (uproto != IPPROTO_TCP)
1567                                                 OPTSET(IN6P_MTU);
1568                                         break;
1569
1570                                 case IPV6_V6ONLY:
1571                                         /*
1572                                          * make setsockopt(IPV6_V6ONLY)
1573                                          * available only prior to bind(2).
1574                                          * see ipng mailing list, Jun 22 2001.
1575                                          */
1576                                         if (in6p->inp_lport ||
1577                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1578                                                 error = EINVAL;
1579                                                 break;
1580                                         }
1581                                         OPTSET(IN6P_IPV6_V6ONLY);
1582                                         if (optval)
1583                                                 in6p->inp_vflag &= ~INP_IPV4;
1584                                         else
1585                                                 in6p->inp_vflag |= INP_IPV4;
1586                                         break;
1587                                 case IPV6_RECVTCLASS:
1588                                         /* cannot mix with RFC2292 XXX */
1589                                         if (OPTBIT(IN6P_RFC2292)) {
1590                                                 error = EINVAL;
1591                                                 break;
1592                                         }
1593                                         OPTSET(IN6P_TCLASS);
1594                                         break;
1595                                 case IPV6_AUTOFLOWLABEL:
1596                                         OPTSET(IN6P_AUTOFLOWLABEL);
1597                                         break;
1598
1599                                 case IPV6_BINDANY:
1600                                         OPTSET(INP_BINDANY);
1601                                         break;
1602
1603                                 case IPV6_BINDMULTI:
1604                                         OPTSET2(INP_BINDMULTI, optval);
1605                                         break;
1606 #ifdef  RSS
1607                                 case IPV6_RSS_LISTEN_BUCKET:
1608                                         if ((optval >= 0) &&
1609                                             (optval < rss_getnumbuckets())) {
1610                                                 in6p->inp_rss_listen_bucket = optval;
1611                                                 OPTSET2(INP_RSS_BUCKET_SET, 1);
1612                                         } else {
1613                                                 error = EINVAL;
1614                                         }
1615                                         break;
1616 #endif
1617                                 }
1618                                 break;
1619
1620                         case IPV6_TCLASS:
1621                         case IPV6_DONTFRAG:
1622                         case IPV6_USE_MIN_MTU:
1623                         case IPV6_PREFER_TEMPADDR:
1624                                 if (optlen != sizeof(optval)) {
1625                                         error = EINVAL;
1626                                         break;
1627                                 }
1628                                 error = sooptcopyin(sopt, &optval,
1629                                         sizeof optval, sizeof optval);
1630                                 if (error)
1631                                         break;
1632                                 {
1633                                         struct ip6_pktopts **optp;
1634                                         optp = &in6p->in6p_outputopts;
1635                                         error = ip6_pcbopt(optname,
1636                                             (u_char *)&optval, sizeof(optval),
1637                                             optp, (td != NULL) ? td->td_ucred :
1638                                             NULL, uproto);
1639                                         break;
1640                                 }
1641
1642                         case IPV6_2292PKTINFO:
1643                         case IPV6_2292HOPLIMIT:
1644                         case IPV6_2292HOPOPTS:
1645                         case IPV6_2292DSTOPTS:
1646                         case IPV6_2292RTHDR:
1647                                 /* RFC 2292 */
1648                                 if (optlen != sizeof(int)) {
1649                                         error = EINVAL;
1650                                         break;
1651                                 }
1652                                 error = sooptcopyin(sopt, &optval,
1653                                         sizeof optval, sizeof optval);
1654                                 if (error)
1655                                         break;
1656                                 switch (optname) {
1657                                 case IPV6_2292PKTINFO:
1658                                         OPTSET2292(IN6P_PKTINFO);
1659                                         break;
1660                                 case IPV6_2292HOPLIMIT:
1661                                         OPTSET2292(IN6P_HOPLIMIT);
1662                                         break;
1663                                 case IPV6_2292HOPOPTS:
1664                                         /*
1665                                          * Check super-user privilege.
1666                                          * See comments for IPV6_RECVHOPOPTS.
1667                                          */
1668                                         if (td != NULL) {
1669                                                 error = priv_check(td,
1670                                                     PRIV_NETINET_SETHDROPTS);
1671                                                 if (error)
1672                                                         return (error);
1673                                         }
1674                                         OPTSET2292(IN6P_HOPOPTS);
1675                                         break;
1676                                 case IPV6_2292DSTOPTS:
1677                                         if (td != NULL) {
1678                                                 error = priv_check(td,
1679                                                     PRIV_NETINET_SETHDROPTS);
1680                                                 if (error)
1681                                                         return (error);
1682                                         }
1683                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1684                                         break;
1685                                 case IPV6_2292RTHDR:
1686                                         OPTSET2292(IN6P_RTHDR);
1687                                         break;
1688                                 }
1689                                 break;
1690                         case IPV6_PKTINFO:
1691                         case IPV6_HOPOPTS:
1692                         case IPV6_RTHDR:
1693                         case IPV6_DSTOPTS:
1694                         case IPV6_RTHDRDSTOPTS:
1695                         case IPV6_NEXTHOP:
1696                         {
1697                                 /* new advanced API (RFC3542) */
1698                                 u_char *optbuf;
1699                                 u_char optbuf_storage[MCLBYTES];
1700                                 int optlen;
1701                                 struct ip6_pktopts **optp;
1702
1703                                 /* cannot mix with RFC2292 */
1704                                 if (OPTBIT(IN6P_RFC2292)) {
1705                                         error = EINVAL;
1706                                         break;
1707                                 }
1708
1709                                 /*
1710                                  * We only ensure valsize is not too large
1711                                  * here.  Further validation will be done
1712                                  * later.
1713                                  */
1714                                 error = sooptcopyin(sopt, optbuf_storage,
1715                                     sizeof(optbuf_storage), 0);
1716                                 if (error)
1717                                         break;
1718                                 optlen = sopt->sopt_valsize;
1719                                 optbuf = optbuf_storage;
1720                                 optp = &in6p->in6p_outputopts;
1721                                 error = ip6_pcbopt(optname, optbuf, optlen,
1722                                     optp, (td != NULL) ? td->td_ucred : NULL,
1723                                     uproto);
1724                                 break;
1725                         }
1726 #undef OPTSET
1727
1728                         case IPV6_MULTICAST_IF:
1729                         case IPV6_MULTICAST_HOPS:
1730                         case IPV6_MULTICAST_LOOP:
1731                         case IPV6_JOIN_GROUP:
1732                         case IPV6_LEAVE_GROUP:
1733                         case IPV6_MSFILTER:
1734                         case MCAST_BLOCK_SOURCE:
1735                         case MCAST_UNBLOCK_SOURCE:
1736                         case MCAST_JOIN_GROUP:
1737                         case MCAST_LEAVE_GROUP:
1738                         case MCAST_JOIN_SOURCE_GROUP:
1739                         case MCAST_LEAVE_SOURCE_GROUP:
1740                                 error = ip6_setmoptions(in6p, sopt);
1741                                 break;
1742
1743                         case IPV6_PORTRANGE:
1744                                 error = sooptcopyin(sopt, &optval,
1745                                     sizeof optval, sizeof optval);
1746                                 if (error)
1747                                         break;
1748
1749                                 INP_WLOCK(in6p);
1750                                 switch (optval) {
1751                                 case IPV6_PORTRANGE_DEFAULT:
1752                                         in6p->inp_flags &= ~(INP_LOWPORT);
1753                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1754                                         break;
1755
1756                                 case IPV6_PORTRANGE_HIGH:
1757                                         in6p->inp_flags &= ~(INP_LOWPORT);
1758                                         in6p->inp_flags |= INP_HIGHPORT;
1759                                         break;
1760
1761                                 case IPV6_PORTRANGE_LOW:
1762                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1763                                         in6p->inp_flags |= INP_LOWPORT;
1764                                         break;
1765
1766                                 default:
1767                                         error = EINVAL;
1768                                         break;
1769                                 }
1770                                 INP_WUNLOCK(in6p);
1771                                 break;
1772
1773 #ifdef IPSEC
1774                         case IPV6_IPSEC_POLICY:
1775                         {
1776                                 caddr_t req;
1777                                 struct mbuf *m;
1778
1779                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1780                                         break;
1781                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1782                                         break;
1783                                 req = mtod(m, caddr_t);
1784                                 error = ipsec_set_policy(in6p, optname, req,
1785                                     m->m_len, (sopt->sopt_td != NULL) ?
1786                                     sopt->sopt_td->td_ucred : NULL);
1787                                 m_freem(m);
1788                                 break;
1789                         }
1790 #endif /* IPSEC */
1791
1792                         default:
1793                                 error = ENOPROTOOPT;
1794                                 break;
1795                         }
1796                         break;
1797
1798                 case SOPT_GET:
1799                         switch (optname) {
1800
1801                         case IPV6_2292PKTOPTIONS:
1802 #ifdef IPV6_PKTOPTIONS
1803                         case IPV6_PKTOPTIONS:
1804 #endif
1805                                 /*
1806                                  * RFC3542 (effectively) deprecated the
1807                                  * semantics of the 2292-style pktoptions.
1808                                  * Since it was not reliable in nature (i.e.,
1809                                  * applications had to expect the lack of some
1810                                  * information after all), it would make sense
1811                                  * to simplify this part by always returning
1812                                  * empty data.
1813                                  */
1814                                 sopt->sopt_valsize = 0;
1815                                 break;
1816
1817                         case IPV6_RECVHOPOPTS:
1818                         case IPV6_RECVDSTOPTS:
1819                         case IPV6_RECVRTHDRDSTOPTS:
1820                         case IPV6_UNICAST_HOPS:
1821                         case IPV6_RECVPKTINFO:
1822                         case IPV6_RECVHOPLIMIT:
1823                         case IPV6_RECVRTHDR:
1824                         case IPV6_RECVPATHMTU:
1825
1826                         case IPV6_FAITH:
1827                         case IPV6_V6ONLY:
1828                         case IPV6_PORTRANGE:
1829                         case IPV6_RECVTCLASS:
1830                         case IPV6_AUTOFLOWLABEL:
1831                         case IPV6_BINDANY:
1832                         case IPV6_FLOWID:
1833                         case IPV6_FLOWTYPE:
1834 #ifdef  RSS
1835                         case IPV6_RSSBUCKETID:
1836 #endif
1837                                 switch (optname) {
1838
1839                                 case IPV6_RECVHOPOPTS:
1840                                         optval = OPTBIT(IN6P_HOPOPTS);
1841                                         break;
1842
1843                                 case IPV6_RECVDSTOPTS:
1844                                         optval = OPTBIT(IN6P_DSTOPTS);
1845                                         break;
1846
1847                                 case IPV6_RECVRTHDRDSTOPTS:
1848                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1849                                         break;
1850
1851                                 case IPV6_UNICAST_HOPS:
1852                                         optval = in6p->in6p_hops;
1853                                         break;
1854
1855                                 case IPV6_RECVPKTINFO:
1856                                         optval = OPTBIT(IN6P_PKTINFO);
1857                                         break;
1858
1859                                 case IPV6_RECVHOPLIMIT:
1860                                         optval = OPTBIT(IN6P_HOPLIMIT);
1861                                         break;
1862
1863                                 case IPV6_RECVRTHDR:
1864                                         optval = OPTBIT(IN6P_RTHDR);
1865                                         break;
1866
1867                                 case IPV6_RECVPATHMTU:
1868                                         optval = OPTBIT(IN6P_MTU);
1869                                         break;
1870
1871                                 case IPV6_FAITH:
1872                                         optval = OPTBIT(INP_FAITH);
1873                                         break;
1874
1875                                 case IPV6_V6ONLY:
1876                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1877                                         break;
1878
1879                                 case IPV6_PORTRANGE:
1880                                     {
1881                                         int flags;
1882                                         flags = in6p->inp_flags;
1883                                         if (flags & INP_HIGHPORT)
1884                                                 optval = IPV6_PORTRANGE_HIGH;
1885                                         else if (flags & INP_LOWPORT)
1886                                                 optval = IPV6_PORTRANGE_LOW;
1887                                         else
1888                                                 optval = 0;
1889                                         break;
1890                                     }
1891                                 case IPV6_RECVTCLASS:
1892                                         optval = OPTBIT(IN6P_TCLASS);
1893                                         break;
1894
1895                                 case IPV6_AUTOFLOWLABEL:
1896                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1897                                         break;
1898
1899                                 case IPV6_BINDANY:
1900                                         optval = OPTBIT(INP_BINDANY);
1901                                         break;
1902
1903                                 case IPV6_FLOWID:
1904                                         optval = in6p->inp_flowid;
1905                                         break;
1906
1907                                 case IPV6_FLOWTYPE:
1908                                         optval = in6p->inp_flowtype;
1909                                         break;
1910 #ifdef  RSS
1911                                 case IPV6_RSSBUCKETID:
1912                                         retval =
1913                                             rss_hash2bucket(in6p->inp_flowid,
1914                                             in6p->inp_flowtype,
1915                                             &rss_bucket);
1916                                         if (retval == 0)
1917                                                 optval = rss_bucket;
1918                                         else
1919                                                 error = EINVAL;
1920                                         break;
1921 #endif
1922
1923                                 case IPV6_BINDMULTI:
1924                                         optval = OPTBIT2(INP_BINDMULTI);
1925                                         break;
1926
1927                                 }
1928                                 if (error)
1929                                         break;
1930                                 error = sooptcopyout(sopt, &optval,
1931                                         sizeof optval);
1932                                 break;
1933
1934                         case IPV6_PATHMTU:
1935                         {
1936                                 u_long pmtu = 0;
1937                                 struct ip6_mtuinfo mtuinfo;
1938                                 struct route_in6 sro;
1939
1940                                 bzero(&sro, sizeof(sro));
1941
1942                                 if (!(so->so_state & SS_ISCONNECTED))
1943                                         return (ENOTCONN);
1944                                 /*
1945                                  * XXX: we dot not consider the case of source
1946                                  * routing, or optional information to specify
1947                                  * the outgoing interface.
1948                                  */
1949                                 error = ip6_getpmtu(&sro, NULL, NULL,
1950                                     &in6p->in6p_faddr, &pmtu, NULL,
1951                                     so->so_fibnum);
1952                                 if (sro.ro_rt)
1953                                         RTFREE(sro.ro_rt);
1954                                 if (error)
1955                                         break;
1956                                 if (pmtu > IPV6_MAXPACKET)
1957                                         pmtu = IPV6_MAXPACKET;
1958
1959                                 bzero(&mtuinfo, sizeof(mtuinfo));
1960                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1961                                 optdata = (void *)&mtuinfo;
1962                                 optdatalen = sizeof(mtuinfo);
1963                                 error = sooptcopyout(sopt, optdata,
1964                                     optdatalen);
1965                                 break;
1966                         }
1967
1968                         case IPV6_2292PKTINFO:
1969                         case IPV6_2292HOPLIMIT:
1970                         case IPV6_2292HOPOPTS:
1971                         case IPV6_2292RTHDR:
1972                         case IPV6_2292DSTOPTS:
1973                                 switch (optname) {
1974                                 case IPV6_2292PKTINFO:
1975                                         optval = OPTBIT(IN6P_PKTINFO);
1976                                         break;
1977                                 case IPV6_2292HOPLIMIT:
1978                                         optval = OPTBIT(IN6P_HOPLIMIT);
1979                                         break;
1980                                 case IPV6_2292HOPOPTS:
1981                                         optval = OPTBIT(IN6P_HOPOPTS);
1982                                         break;
1983                                 case IPV6_2292RTHDR:
1984                                         optval = OPTBIT(IN6P_RTHDR);
1985                                         break;
1986                                 case IPV6_2292DSTOPTS:
1987                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1988                                         break;
1989                                 }
1990                                 error = sooptcopyout(sopt, &optval,
1991                                     sizeof optval);
1992                                 break;
1993                         case IPV6_PKTINFO:
1994                         case IPV6_HOPOPTS:
1995                         case IPV6_RTHDR:
1996                         case IPV6_DSTOPTS:
1997                         case IPV6_RTHDRDSTOPTS:
1998                         case IPV6_NEXTHOP:
1999                         case IPV6_TCLASS:
2000                         case IPV6_DONTFRAG:
2001                         case IPV6_USE_MIN_MTU:
2002                         case IPV6_PREFER_TEMPADDR:
2003                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
2004                                     optname, sopt);
2005                                 break;
2006
2007                         case IPV6_MULTICAST_IF:
2008                         case IPV6_MULTICAST_HOPS:
2009                         case IPV6_MULTICAST_LOOP:
2010                         case IPV6_MSFILTER:
2011                                 error = ip6_getmoptions(in6p, sopt);
2012                                 break;
2013
2014 #ifdef IPSEC
2015                         case IPV6_IPSEC_POLICY:
2016                           {
2017                                 caddr_t req = NULL;
2018                                 size_t len = 0;
2019                                 struct mbuf *m = NULL;
2020                                 struct mbuf **mp = &m;
2021                                 size_t ovalsize = sopt->sopt_valsize;
2022                                 caddr_t oval = (caddr_t)sopt->sopt_val;
2023
2024                                 error = soopt_getm(sopt, &m); /* XXX */
2025                                 if (error != 0)
2026                                         break;
2027                                 error = soopt_mcopyin(sopt, m); /* XXX */
2028                                 if (error != 0)
2029                                         break;
2030                                 sopt->sopt_valsize = ovalsize;
2031                                 sopt->sopt_val = oval;
2032                                 if (m) {
2033                                         req = mtod(m, caddr_t);
2034                                         len = m->m_len;
2035                                 }
2036                                 error = ipsec_get_policy(in6p, req, len, mp);
2037                                 if (error == 0)
2038                                         error = soopt_mcopyout(sopt, m); /* XXX */
2039                                 if (error == 0 && m)
2040                                         m_freem(m);
2041                                 break;
2042                           }
2043 #endif /* IPSEC */
2044
2045                         default:
2046                                 error = ENOPROTOOPT;
2047                                 break;
2048                         }
2049                         break;
2050                 }
2051         }
2052         return (error);
2053 }
2054
2055 int
2056 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2057 {
2058         int error = 0, optval, optlen;
2059         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2060         struct inpcb *in6p = sotoinpcb(so);
2061         int level, op, optname;
2062
2063         level = sopt->sopt_level;
2064         op = sopt->sopt_dir;
2065         optname = sopt->sopt_name;
2066         optlen = sopt->sopt_valsize;
2067
2068         if (level != IPPROTO_IPV6) {
2069                 return (EINVAL);
2070         }
2071
2072         switch (optname) {
2073         case IPV6_CHECKSUM:
2074                 /*
2075                  * For ICMPv6 sockets, no modification allowed for checksum
2076                  * offset, permit "no change" values to help existing apps.
2077                  *
2078                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2079                  * for an ICMPv6 socket will fail."
2080                  * The current behavior does not meet RFC3542.
2081                  */
2082                 switch (op) {
2083                 case SOPT_SET:
2084                         if (optlen != sizeof(int)) {
2085                                 error = EINVAL;
2086                                 break;
2087                         }
2088                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2089                                             sizeof(optval));
2090                         if (error)
2091                                 break;
2092                         if ((optval % 2) != 0) {
2093                                 /* the API assumes even offset values */
2094                                 error = EINVAL;
2095                         } else if (so->so_proto->pr_protocol ==
2096                             IPPROTO_ICMPV6) {
2097                                 if (optval != icmp6off)
2098                                         error = EINVAL;
2099                         } else
2100                                 in6p->in6p_cksum = optval;
2101                         break;
2102
2103                 case SOPT_GET:
2104                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2105                                 optval = icmp6off;
2106                         else
2107                                 optval = in6p->in6p_cksum;
2108
2109                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2110                         break;
2111
2112                 default:
2113                         error = EINVAL;
2114                         break;
2115                 }
2116                 break;
2117
2118         default:
2119                 error = ENOPROTOOPT;
2120                 break;
2121         }
2122
2123         return (error);
2124 }
2125
2126 /*
2127  * Set up IP6 options in pcb for insertion in output packets or
2128  * specifying behavior of outgoing packets.
2129  */
2130 static int
2131 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2132     struct socket *so, struct sockopt *sopt)
2133 {
2134         struct ip6_pktopts *opt = *pktopt;
2135         int error = 0;
2136         struct thread *td = sopt->sopt_td;
2137
2138         /* turn off any old options. */
2139         if (opt) {
2140 #ifdef DIAGNOSTIC
2141                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2142                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2143                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2144                         printf("ip6_pcbopts: all specified options are cleared.\n");
2145 #endif
2146                 ip6_clearpktopts(opt, -1);
2147         } else
2148                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2149         *pktopt = NULL;
2150
2151         if (!m || m->m_len == 0) {
2152                 /*
2153                  * Only turning off any previous options, regardless of
2154                  * whether the opt is just created or given.
2155                  */
2156                 free(opt, M_IP6OPT);
2157                 return (0);
2158         }
2159
2160         /*  set options specified by user. */
2161         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2162             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2163                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2164                 free(opt, M_IP6OPT);
2165                 return (error);
2166         }
2167         *pktopt = opt;
2168         return (0);
2169 }
2170
2171 /*
2172  * initialize ip6_pktopts.  beware that there are non-zero default values in
2173  * the struct.
2174  */
2175 void
2176 ip6_initpktopts(struct ip6_pktopts *opt)
2177 {
2178
2179         bzero(opt, sizeof(*opt));
2180         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2181         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2182         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2183         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2184 }
2185
2186 static int
2187 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2188     struct ucred *cred, int uproto)
2189 {
2190         struct ip6_pktopts *opt;
2191
2192         if (*pktopt == NULL) {
2193                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2194                     M_WAITOK);
2195                 ip6_initpktopts(*pktopt);
2196         }
2197         opt = *pktopt;
2198
2199         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2200 }
2201
2202 static int
2203 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2204 {
2205         void *optdata = NULL;
2206         int optdatalen = 0;
2207         struct ip6_ext *ip6e;
2208         int error = 0;
2209         struct in6_pktinfo null_pktinfo;
2210         int deftclass = 0, on;
2211         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2212         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2213
2214         switch (optname) {
2215         case IPV6_PKTINFO:
2216                 if (pktopt && pktopt->ip6po_pktinfo)
2217                         optdata = (void *)pktopt->ip6po_pktinfo;
2218                 else {
2219                         /* XXX: we don't have to do this every time... */
2220                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2221                         optdata = (void *)&null_pktinfo;
2222                 }
2223                 optdatalen = sizeof(struct in6_pktinfo);
2224                 break;
2225         case IPV6_TCLASS:
2226                 if (pktopt && pktopt->ip6po_tclass >= 0)
2227                         optdata = (void *)&pktopt->ip6po_tclass;
2228                 else
2229                         optdata = (void *)&deftclass;
2230                 optdatalen = sizeof(int);
2231                 break;
2232         case IPV6_HOPOPTS:
2233                 if (pktopt && pktopt->ip6po_hbh) {
2234                         optdata = (void *)pktopt->ip6po_hbh;
2235                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2236                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2237                 }
2238                 break;
2239         case IPV6_RTHDR:
2240                 if (pktopt && pktopt->ip6po_rthdr) {
2241                         optdata = (void *)pktopt->ip6po_rthdr;
2242                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2243                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2244                 }
2245                 break;
2246         case IPV6_RTHDRDSTOPTS:
2247                 if (pktopt && pktopt->ip6po_dest1) {
2248                         optdata = (void *)pktopt->ip6po_dest1;
2249                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2250                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2251                 }
2252                 break;
2253         case IPV6_DSTOPTS:
2254                 if (pktopt && pktopt->ip6po_dest2) {
2255                         optdata = (void *)pktopt->ip6po_dest2;
2256                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2257                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2258                 }
2259                 break;
2260         case IPV6_NEXTHOP:
2261                 if (pktopt && pktopt->ip6po_nexthop) {
2262                         optdata = (void *)pktopt->ip6po_nexthop;
2263                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2264                 }
2265                 break;
2266         case IPV6_USE_MIN_MTU:
2267                 if (pktopt)
2268                         optdata = (void *)&pktopt->ip6po_minmtu;
2269                 else
2270                         optdata = (void *)&defminmtu;
2271                 optdatalen = sizeof(int);
2272                 break;
2273         case IPV6_DONTFRAG:
2274                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2275                         on = 1;
2276                 else
2277                         on = 0;
2278                 optdata = (void *)&on;
2279                 optdatalen = sizeof(on);
2280                 break;
2281         case IPV6_PREFER_TEMPADDR:
2282                 if (pktopt)
2283                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2284                 else
2285                         optdata = (void *)&defpreftemp;
2286                 optdatalen = sizeof(int);
2287                 break;
2288         default:                /* should not happen */
2289 #ifdef DIAGNOSTIC
2290                 panic("ip6_getpcbopt: unexpected option\n");
2291 #endif
2292                 return (ENOPROTOOPT);
2293         }
2294
2295         error = sooptcopyout(sopt, optdata, optdatalen);
2296
2297         return (error);
2298 }
2299
2300 void
2301 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2302 {
2303         if (pktopt == NULL)
2304                 return;
2305
2306         if (optname == -1 || optname == IPV6_PKTINFO) {
2307                 if (pktopt->ip6po_pktinfo)
2308                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2309                 pktopt->ip6po_pktinfo = NULL;
2310         }
2311         if (optname == -1 || optname == IPV6_HOPLIMIT)
2312                 pktopt->ip6po_hlim = -1;
2313         if (optname == -1 || optname == IPV6_TCLASS)
2314                 pktopt->ip6po_tclass = -1;
2315         if (optname == -1 || optname == IPV6_NEXTHOP) {
2316                 if (pktopt->ip6po_nextroute.ro_rt) {
2317                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2318                         pktopt->ip6po_nextroute.ro_rt = NULL;
2319                 }
2320                 if (pktopt->ip6po_nexthop)
2321                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2322                 pktopt->ip6po_nexthop = NULL;
2323         }
2324         if (optname == -1 || optname == IPV6_HOPOPTS) {
2325                 if (pktopt->ip6po_hbh)
2326                         free(pktopt->ip6po_hbh, M_IP6OPT);
2327                 pktopt->ip6po_hbh = NULL;
2328         }
2329         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2330                 if (pktopt->ip6po_dest1)
2331                         free(pktopt->ip6po_dest1, M_IP6OPT);
2332                 pktopt->ip6po_dest1 = NULL;
2333         }
2334         if (optname == -1 || optname == IPV6_RTHDR) {
2335                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2336                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2337                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2338                 if (pktopt->ip6po_route.ro_rt) {
2339                         RTFREE(pktopt->ip6po_route.ro_rt);
2340                         pktopt->ip6po_route.ro_rt = NULL;
2341                 }
2342         }
2343         if (optname == -1 || optname == IPV6_DSTOPTS) {
2344                 if (pktopt->ip6po_dest2)
2345                         free(pktopt->ip6po_dest2, M_IP6OPT);
2346                 pktopt->ip6po_dest2 = NULL;
2347         }
2348 }
2349
2350 #define PKTOPT_EXTHDRCPY(type) \
2351 do {\
2352         if (src->type) {\
2353                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2354                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2355                 if (dst->type == NULL && canwait == M_NOWAIT)\
2356                         goto bad;\
2357                 bcopy(src->type, dst->type, hlen);\
2358         }\
2359 } while (/*CONSTCOND*/ 0)
2360
2361 static int
2362 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2363 {
2364         if (dst == NULL || src == NULL)  {
2365                 printf("ip6_clearpktopts: invalid argument\n");
2366                 return (EINVAL);
2367         }
2368
2369         dst->ip6po_hlim = src->ip6po_hlim;
2370         dst->ip6po_tclass = src->ip6po_tclass;
2371         dst->ip6po_flags = src->ip6po_flags;
2372         dst->ip6po_minmtu = src->ip6po_minmtu;
2373         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2374         if (src->ip6po_pktinfo) {
2375                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2376                     M_IP6OPT, canwait);
2377                 if (dst->ip6po_pktinfo == NULL)
2378                         goto bad;
2379                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2380         }
2381         if (src->ip6po_nexthop) {
2382                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2383                     M_IP6OPT, canwait);
2384                 if (dst->ip6po_nexthop == NULL)
2385                         goto bad;
2386                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2387                     src->ip6po_nexthop->sa_len);
2388         }
2389         PKTOPT_EXTHDRCPY(ip6po_hbh);
2390         PKTOPT_EXTHDRCPY(ip6po_dest1);
2391         PKTOPT_EXTHDRCPY(ip6po_dest2);
2392         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2393         return (0);
2394
2395   bad:
2396         ip6_clearpktopts(dst, -1);
2397         return (ENOBUFS);
2398 }
2399 #undef PKTOPT_EXTHDRCPY
2400
2401 struct ip6_pktopts *
2402 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2403 {
2404         int error;
2405         struct ip6_pktopts *dst;
2406
2407         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2408         if (dst == NULL)
2409                 return (NULL);
2410         ip6_initpktopts(dst);
2411
2412         if ((error = copypktopts(dst, src, canwait)) != 0) {
2413                 free(dst, M_IP6OPT);
2414                 return (NULL);
2415         }
2416
2417         return (dst);
2418 }
2419
2420 void
2421 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2422 {
2423         if (pktopt == NULL)
2424                 return;
2425
2426         ip6_clearpktopts(pktopt, -1);
2427
2428         free(pktopt, M_IP6OPT);
2429 }
2430
2431 /*
2432  * Set IPv6 outgoing packet options based on advanced API.
2433  */
2434 int
2435 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2436     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2437 {
2438         struct cmsghdr *cm = 0;
2439
2440         if (control == NULL || opt == NULL)
2441                 return (EINVAL);
2442
2443         ip6_initpktopts(opt);
2444         if (stickyopt) {
2445                 int error;
2446
2447                 /*
2448                  * If stickyopt is provided, make a local copy of the options
2449                  * for this particular packet, then override them by ancillary
2450                  * objects.
2451                  * XXX: copypktopts() does not copy the cached route to a next
2452                  * hop (if any).  This is not very good in terms of efficiency,
2453                  * but we can allow this since this option should be rarely
2454                  * used.
2455                  */
2456                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2457                         return (error);
2458         }
2459
2460         /*
2461          * XXX: Currently, we assume all the optional information is stored
2462          * in a single mbuf.
2463          */
2464         if (control->m_next)
2465                 return (EINVAL);
2466
2467         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2468             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2469                 int error;
2470
2471                 if (control->m_len < CMSG_LEN(0))
2472                         return (EINVAL);
2473
2474                 cm = mtod(control, struct cmsghdr *);
2475                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2476                         return (EINVAL);
2477                 if (cm->cmsg_level != IPPROTO_IPV6)
2478                         continue;
2479
2480                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2481                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2482                 if (error)
2483                         return (error);
2484         }
2485
2486         return (0);
2487 }
2488
2489 /*
2490  * Set a particular packet option, as a sticky option or an ancillary data
2491  * item.  "len" can be 0 only when it's a sticky option.
2492  * We have 4 cases of combination of "sticky" and "cmsg":
2493  * "sticky=0, cmsg=0": impossible
2494  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2495  * "sticky=1, cmsg=0": RFC3542 socket option
2496  * "sticky=1, cmsg=1": RFC2292 socket option
2497  */
2498 static int
2499 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2500     struct ucred *cred, int sticky, int cmsg, int uproto)
2501 {
2502         int minmtupolicy, preftemp;
2503         int error;
2504
2505         if (!sticky && !cmsg) {
2506 #ifdef DIAGNOSTIC
2507                 printf("ip6_setpktopt: impossible case\n");
2508 #endif
2509                 return (EINVAL);
2510         }
2511
2512         /*
2513          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2514          * not be specified in the context of RFC3542.  Conversely,
2515          * RFC3542 types should not be specified in the context of RFC2292.
2516          */
2517         if (!cmsg) {
2518                 switch (optname) {
2519                 case IPV6_2292PKTINFO:
2520                 case IPV6_2292HOPLIMIT:
2521                 case IPV6_2292NEXTHOP:
2522                 case IPV6_2292HOPOPTS:
2523                 case IPV6_2292DSTOPTS:
2524                 case IPV6_2292RTHDR:
2525                 case IPV6_2292PKTOPTIONS:
2526                         return (ENOPROTOOPT);
2527                 }
2528         }
2529         if (sticky && cmsg) {
2530                 switch (optname) {
2531                 case IPV6_PKTINFO:
2532                 case IPV6_HOPLIMIT:
2533                 case IPV6_NEXTHOP:
2534                 case IPV6_HOPOPTS:
2535                 case IPV6_DSTOPTS:
2536                 case IPV6_RTHDRDSTOPTS:
2537                 case IPV6_RTHDR:
2538                 case IPV6_USE_MIN_MTU:
2539                 case IPV6_DONTFRAG:
2540                 case IPV6_TCLASS:
2541                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2542                         return (ENOPROTOOPT);
2543                 }
2544         }
2545
2546         switch (optname) {
2547         case IPV6_2292PKTINFO:
2548         case IPV6_PKTINFO:
2549         {
2550                 struct ifnet *ifp = NULL;
2551                 struct in6_pktinfo *pktinfo;
2552
2553                 if (len != sizeof(struct in6_pktinfo))
2554                         return (EINVAL);
2555
2556                 pktinfo = (struct in6_pktinfo *)buf;
2557
2558                 /*
2559                  * An application can clear any sticky IPV6_PKTINFO option by
2560                  * doing a "regular" setsockopt with ipi6_addr being
2561                  * in6addr_any and ipi6_ifindex being zero.
2562                  * [RFC 3542, Section 6]
2563                  */
2564                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2565                     pktinfo->ipi6_ifindex == 0 &&
2566                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2567                         ip6_clearpktopts(opt, optname);
2568                         break;
2569                 }
2570
2571                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2572                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2573                         return (EINVAL);
2574                 }
2575                 if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2576                         return (EINVAL);
2577                 /* validate the interface index if specified. */
2578                 if (pktinfo->ipi6_ifindex > V_if_index)
2579                          return (ENXIO);
2580                 if (pktinfo->ipi6_ifindex) {
2581                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2582                         if (ifp == NULL)
2583                                 return (ENXIO);
2584                 }
2585                 if (ifp != NULL && (
2586                     ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED))
2587                         return (ENETDOWN);
2588
2589                 if (ifp != NULL &&
2590                     !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2591                         struct in6_ifaddr *ia;
2592
2593                         ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2594                         if (ia == NULL)
2595                                 return (EADDRNOTAVAIL);
2596                         ifa_free(&ia->ia_ifa);
2597                 }
2598                 /*
2599                  * We store the address anyway, and let in6_selectsrc()
2600                  * validate the specified address.  This is because ipi6_addr
2601                  * may not have enough information about its scope zone, and
2602                  * we may need additional information (such as outgoing
2603                  * interface or the scope zone of a destination address) to
2604                  * disambiguate the scope.
2605                  * XXX: the delay of the validation may confuse the
2606                  * application when it is used as a sticky option.
2607                  */
2608                 if (opt->ip6po_pktinfo == NULL) {
2609                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2610                             M_IP6OPT, M_NOWAIT);
2611                         if (opt->ip6po_pktinfo == NULL)
2612                                 return (ENOBUFS);
2613                 }
2614                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2615                 break;
2616         }
2617
2618         case IPV6_2292HOPLIMIT:
2619         case IPV6_HOPLIMIT:
2620         {
2621                 int *hlimp;
2622
2623                 /*
2624                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2625                  * to simplify the ordering among hoplimit options.
2626                  */
2627                 if (optname == IPV6_HOPLIMIT && sticky)
2628                         return (ENOPROTOOPT);
2629
2630                 if (len != sizeof(int))
2631                         return (EINVAL);
2632                 hlimp = (int *)buf;
2633                 if (*hlimp < -1 || *hlimp > 255)
2634                         return (EINVAL);
2635
2636                 opt->ip6po_hlim = *hlimp;
2637                 break;
2638         }
2639
2640         case IPV6_TCLASS:
2641         {
2642                 int tclass;
2643
2644                 if (len != sizeof(int))
2645                         return (EINVAL);
2646                 tclass = *(int *)buf;
2647                 if (tclass < -1 || tclass > 255)
2648                         return (EINVAL);
2649
2650                 opt->ip6po_tclass = tclass;
2651                 break;
2652         }
2653
2654         case IPV6_2292NEXTHOP:
2655         case IPV6_NEXTHOP:
2656                 if (cred != NULL) {
2657                         error = priv_check_cred(cred,
2658                             PRIV_NETINET_SETHDROPTS, 0);
2659                         if (error)
2660                                 return (error);
2661                 }
2662
2663                 if (len == 0) { /* just remove the option */
2664                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2665                         break;
2666                 }
2667
2668                 /* check if cmsg_len is large enough for sa_len */
2669                 if (len < sizeof(struct sockaddr) || len < *buf)
2670                         return (EINVAL);
2671
2672                 switch (((struct sockaddr *)buf)->sa_family) {
2673                 case AF_INET6:
2674                 {
2675                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2676                         int error;
2677
2678                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2679                                 return (EINVAL);
2680
2681                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2682                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2683                                 return (EINVAL);
2684                         }
2685                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2686                             != 0) {
2687                                 return (error);
2688                         }
2689                         break;
2690                 }
2691                 case AF_LINK:   /* should eventually be supported */
2692                 default:
2693                         return (EAFNOSUPPORT);
2694                 }
2695
2696                 /* turn off the previous option, then set the new option. */
2697                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2698                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2699                 if (opt->ip6po_nexthop == NULL)
2700                         return (ENOBUFS);
2701                 bcopy(buf, opt->ip6po_nexthop, *buf);
2702                 break;
2703
2704         case IPV6_2292HOPOPTS:
2705         case IPV6_HOPOPTS:
2706         {
2707                 struct ip6_hbh *hbh;
2708                 int hbhlen;
2709
2710                 /*
2711                  * XXX: We don't allow a non-privileged user to set ANY HbH
2712                  * options, since per-option restriction has too much
2713                  * overhead.
2714                  */
2715                 if (cred != NULL) {
2716                         error = priv_check_cred(cred,
2717                             PRIV_NETINET_SETHDROPTS, 0);
2718                         if (error)
2719                                 return (error);
2720                 }
2721
2722                 if (len == 0) {
2723                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2724                         break;  /* just remove the option */
2725                 }
2726
2727                 /* message length validation */
2728                 if (len < sizeof(struct ip6_hbh))
2729                         return (EINVAL);
2730                 hbh = (struct ip6_hbh *)buf;
2731                 hbhlen = (hbh->ip6h_len + 1) << 3;
2732                 if (len != hbhlen)
2733                         return (EINVAL);
2734
2735                 /* turn off the previous option, then set the new option. */
2736                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2737                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2738                 if (opt->ip6po_hbh == NULL)
2739                         return (ENOBUFS);
2740                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2741
2742                 break;
2743         }
2744
2745         case IPV6_2292DSTOPTS:
2746         case IPV6_DSTOPTS:
2747         case IPV6_RTHDRDSTOPTS:
2748         {
2749                 struct ip6_dest *dest, **newdest = NULL;
2750                 int destlen;
2751
2752                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2753                         error = priv_check_cred(cred,
2754                             PRIV_NETINET_SETHDROPTS, 0);
2755                         if (error)
2756                                 return (error);
2757                 }
2758
2759                 if (len == 0) {
2760                         ip6_clearpktopts(opt, optname);
2761                         break;  /* just remove the option */
2762                 }
2763
2764                 /* message length validation */
2765                 if (len < sizeof(struct ip6_dest))
2766                         return (EINVAL);
2767                 dest = (struct ip6_dest *)buf;
2768                 destlen = (dest->ip6d_len + 1) << 3;
2769                 if (len != destlen)
2770                         return (EINVAL);
2771
2772                 /*
2773                  * Determine the position that the destination options header
2774                  * should be inserted; before or after the routing header.
2775                  */
2776                 switch (optname) {
2777                 case IPV6_2292DSTOPTS:
2778                         /*
2779                          * The old advacned API is ambiguous on this point.
2780                          * Our approach is to determine the position based
2781                          * according to the existence of a routing header.
2782                          * Note, however, that this depends on the order of the
2783                          * extension headers in the ancillary data; the 1st
2784                          * part of the destination options header must appear
2785                          * before the routing header in the ancillary data,
2786                          * too.
2787                          * RFC3542 solved the ambiguity by introducing
2788                          * separate ancillary data or option types.
2789                          */
2790                         if (opt->ip6po_rthdr == NULL)
2791                                 newdest = &opt->ip6po_dest1;
2792                         else
2793                                 newdest = &opt->ip6po_dest2;
2794                         break;
2795                 case IPV6_RTHDRDSTOPTS:
2796                         newdest = &opt->ip6po_dest1;
2797                         break;
2798                 case IPV6_DSTOPTS:
2799                         newdest = &opt->ip6po_dest2;
2800                         break;
2801                 }
2802
2803                 /* turn off the previous option, then set the new option. */
2804                 ip6_clearpktopts(opt, optname);
2805                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2806                 if (*newdest == NULL)
2807                         return (ENOBUFS);
2808                 bcopy(dest, *newdest, destlen);
2809
2810                 break;
2811         }
2812
2813         case IPV6_2292RTHDR:
2814         case IPV6_RTHDR:
2815         {
2816                 struct ip6_rthdr *rth;
2817                 int rthlen;
2818
2819                 if (len == 0) {
2820                         ip6_clearpktopts(opt, IPV6_RTHDR);
2821                         break;  /* just remove the option */
2822                 }
2823
2824                 /* message length validation */
2825                 if (len < sizeof(struct ip6_rthdr))
2826                         return (EINVAL);
2827                 rth = (struct ip6_rthdr *)buf;
2828                 rthlen = (rth->ip6r_len + 1) << 3;
2829                 if (len != rthlen)
2830                         return (EINVAL);
2831
2832                 switch (rth->ip6r_type) {
2833                 case IPV6_RTHDR_TYPE_0:
2834                         if (rth->ip6r_len == 0) /* must contain one addr */
2835                                 return (EINVAL);
2836                         if (rth->ip6r_len % 2) /* length must be even */
2837                                 return (EINVAL);
2838                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2839                                 return (EINVAL);
2840                         break;
2841                 default:
2842                         return (EINVAL);        /* not supported */
2843                 }
2844
2845                 /* turn off the previous option */
2846                 ip6_clearpktopts(opt, IPV6_RTHDR);
2847                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2848                 if (opt->ip6po_rthdr == NULL)
2849                         return (ENOBUFS);
2850                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2851
2852                 break;
2853         }
2854
2855         case IPV6_USE_MIN_MTU:
2856                 if (len != sizeof(int))
2857                         return (EINVAL);
2858                 minmtupolicy = *(int *)buf;
2859                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2860                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2861                     minmtupolicy != IP6PO_MINMTU_ALL) {
2862                         return (EINVAL);
2863                 }
2864                 opt->ip6po_minmtu = minmtupolicy;
2865                 break;
2866
2867         case IPV6_DONTFRAG:
2868                 if (len != sizeof(int))
2869                         return (EINVAL);
2870
2871                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2872                         /*
2873                          * we ignore this option for TCP sockets.
2874                          * (RFC3542 leaves this case unspecified.)
2875                          */
2876                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2877                 } else
2878                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2879                 break;
2880
2881         case IPV6_PREFER_TEMPADDR:
2882                 if (len != sizeof(int))
2883                         return (EINVAL);
2884                 preftemp = *(int *)buf;
2885                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2886                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2887                     preftemp != IP6PO_TEMPADDR_PREFER) {
2888                         return (EINVAL);
2889                 }
2890                 opt->ip6po_prefer_tempaddr = preftemp;
2891                 break;
2892
2893         default:
2894                 return (ENOPROTOOPT);
2895         } /* end of switch */
2896
2897         return (0);
2898 }
2899
2900 /*
2901  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2902  * packet to the input queue of a specified interface.  Note that this
2903  * calls the output routine of the loopback "driver", but with an interface
2904  * pointer that might NOT be &loif -- easier than replicating that code here.
2905  */
2906 void
2907 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
2908 {
2909         struct mbuf *copym;
2910         struct ip6_hdr *ip6;
2911
2912         copym = m_copy(m, 0, M_COPYALL);
2913         if (copym == NULL)
2914                 return;
2915
2916         /*
2917          * Make sure to deep-copy IPv6 header portion in case the data
2918          * is in an mbuf cluster, so that we can safely override the IPv6
2919          * header portion later.
2920          */
2921         if (!M_WRITABLE(copym) ||
2922             copym->m_len < sizeof(struct ip6_hdr)) {
2923                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
2924                 if (copym == NULL)
2925                         return;
2926         }
2927
2928 #ifdef DIAGNOSTIC
2929         if (copym->m_len < sizeof(*ip6)) {
2930                 m_freem(copym);
2931                 return;
2932         }
2933 #endif
2934
2935         ip6 = mtod(copym, struct ip6_hdr *);
2936         /*
2937          * clear embedded scope identifiers if necessary.
2938          * in6_clearscope will touch the addresses only when necessary.
2939          */
2940         in6_clearscope(&ip6->ip6_src);
2941         in6_clearscope(&ip6->ip6_dst);
2942
2943         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
2944 }
2945
2946 /*
2947  * Chop IPv6 header off from the payload.
2948  */
2949 static int
2950 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
2951 {
2952         struct mbuf *mh;
2953         struct ip6_hdr *ip6;
2954
2955         ip6 = mtod(m, struct ip6_hdr *);
2956         if (m->m_len > sizeof(*ip6)) {
2957                 mh = m_gethdr(M_NOWAIT, MT_DATA);
2958                 if (mh == NULL) {
2959                         m_freem(m);
2960                         return ENOBUFS;
2961                 }
2962                 m_move_pkthdr(mh, m);
2963                 MH_ALIGN(mh, sizeof(*ip6));
2964                 m->m_len -= sizeof(*ip6);
2965                 m->m_data += sizeof(*ip6);
2966                 mh->m_next = m;
2967                 m = mh;
2968                 m->m_len = sizeof(*ip6);
2969                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
2970         }
2971         exthdrs->ip6e_ip6 = m;
2972         return 0;
2973 }
2974
2975 /*
2976  * Compute IPv6 extension header length.
2977  */
2978 int
2979 ip6_optlen(struct inpcb *in6p)
2980 {
2981         int len;
2982
2983         if (!in6p->in6p_outputopts)
2984                 return 0;
2985
2986         len = 0;
2987 #define elen(x) \
2988     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
2989
2990         len += elen(in6p->in6p_outputopts->ip6po_hbh);
2991         if (in6p->in6p_outputopts->ip6po_rthdr)
2992                 /* dest1 is valid with rthdr only */
2993                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
2994         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
2995         len += elen(in6p->in6p_outputopts->ip6po_dest2);
2996         return len;
2997 #undef elen
2998 }