sys/netinet6/ip6_output.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipfw.h"
  69 #include "opt_ipsec.h"
  70 #include "opt_sctp.h"
  71 #include "opt_route.h"
  72 #include "opt_rss.h"
  73
  74 #include <sys/param.h>
  75 #include <sys/kernel.h>
  76 #include <sys/malloc.h>
  77 #include <sys/mbuf.h>
  78 #include <sys/errno.h>
  79 #include <sys/priv.h>
  80 #include <sys/proc.h>
  81 #include <sys/protosw.h>
  82 #include <sys/socket.h>
  83 #include <sys/socketvar.h>
  84 #include <sys/syslog.h>
  85 #include <sys/ucred.h>
  86
  87 #include <machine/in_cksum.h>
  88
  89 #include <net/if.h>
  90 #include <net/if_var.h>
  91 #include <net/netisr.h>
  92 #include <net/route.h>
  93 #include <net/pfil.h>
  94 #include <net/rss_config.h>
  95 #include <net/vnet.h>
  96
  97 #include <netinet/in.h>
  98 #include <netinet/in_var.h>
  99 #include <netinet/ip_var.h>
 100 #include <netinet6/in6_fib.h>
 101 #include <netinet6/in6_var.h>
 102 #include <netinet/ip6.h>
 103 #include <netinet/icmp6.h>
 104 #include <netinet6/ip6_var.h>
 105 #include <netinet/in_pcb.h>
 106 #include <netinet/tcp_var.h>
 107 #include <netinet6/nd6.h>
 108 #include <netinet6/in6_rss.h>
 109
 110 #ifdef IPSEC
 111 #include <netipsec/ipsec.h>
 112 #include <netipsec/ipsec6.h>
 113 #include <netipsec/key.h>
 114 #include <netinet6/ip6_ipsec.h>
 115 #endif /* IPSEC */
 116 #ifdef SCTP
 117 #include <netinet/sctp.h>
 118 #include <netinet/sctp_crc32.h>
 119 #endif
 120
 121 #include <netinet6/ip6protosw.h>
 122 #include <netinet6/scope6_var.h>
 123
 124 #ifdef FLOWTABLE
 125 #include <net/flowtable.h>
 126 #endif
 127
 128 extern int in6_mcast_loop;
 129
 130 struct ip6_exthdrs {
 131         struct mbuf *ip6e_ip6;
 132         struct mbuf *ip6e_hbh;
 133         struct mbuf *ip6e_dest1;
 134         struct mbuf *ip6e_rthdr;
 135         struct mbuf *ip6e_dest2;
 136 };
 137
 138 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
 139                            struct ucred *, int);
 140 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
 141         struct socket *, struct sockopt *);
 142 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
 143 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
 144         struct ucred *, int, int, int);
 145
 146 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 147 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
 148         struct ip6_frag **);
 149 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 150 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 151 static int ip6_getpmtu(struct route_in6 *, int,
 152         struct ifnet *, struct in6_addr *, u_long *, int *, u_int);
 153 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
 154         u_long *, int *);
 155 static int ip6_getpmtu_ctl(u_int, struct in6_addr *, u_long *);
 156 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 157
 158
 159 /*
 160  * Make an extension header from option data.  hp is the source, and
 161  * mp is the destination.
 162  */
 163 #define MAKE_EXTHDR(hp, mp)                                             \
 164     do {                                                                \
 165         if (hp) {                                                       \
 166                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 167                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 168                     ((eh)->ip6e_len + 1) << 3);                         \
 169                 if (error)                                              \
 170                         goto freehdrs;                                  \
 171         }                                                               \
 172     } while (/*CONSTCOND*/ 0)
 173
 174 /*
 175  * Form a chain of extension headers.
 176  * m is the extension header mbuf
 177  * mp is the previous mbuf in the chain
 178  * p is the next header
 179  * i is the type of option.
 180  */
 181 #define MAKE_CHAIN(m, mp, p, i)\
 182     do {\
 183         if (m) {\
 184                 if (!hdrsplit) \
 185                         panic("assumption failed: hdr not split"); \
 186                 *mtod((m), u_char *) = *(p);\
 187                 *(p) = (i);\
 188                 p = mtod((m), u_char *);\
 189                 (m)->m_next = (mp)->m_next;\
 190                 (mp)->m_next = (m);\
 191                 (mp) = (m);\
 192         }\
 193     } while (/*CONSTCOND*/ 0)
 194
 195 void
 196 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
 197 {
 198         u_short csum;
 199
 200         csum = in_cksum_skip(m, offset + plen, offset);
 201         if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
 202                 csum = 0xffff;
 203         offset += m->m_pkthdr.csum_data;        /* checksum offset */
 204
 205         if (offset + sizeof(u_short) > m->m_len) {
 206                 printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
 207                     "csum_flags=%b\n", __func__, m->m_len, plen, offset,
 208                     (int)m->m_pkthdr.csum_flags, CSUM_BITS);
 209                 /*
 210                  * XXX this should not happen, but if it does, the correct
 211                  * behavior may be to insert the checksum in the appropriate
 212                  * next mbuf in the chain.
 213                  */
 214                 return;
 215         }
 216         *(u_short *)(m->m_data + offset) = csum;
 217 }
 218
 219 int
 220 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
 221     int mtu, uint32_t id)
 222 {
 223         struct mbuf *m, **mnext, *m_frgpart;
 224         struct ip6_hdr *ip6, *mhip6;
 225         struct ip6_frag *ip6f;
 226         int off;
 227         int error;
 228         int tlen = m0->m_pkthdr.len;
 229
 230         m = m0;
 231         ip6 = mtod(m, struct ip6_hdr *);
 232         mnext = &m->m_nextpkt;
 233
 234         for (off = hlen; off < tlen; off += mtu) {
 235                 m = m_gethdr(M_NOWAIT, MT_DATA);
 236                 if (!m) {
 237                         IP6STAT_INC(ip6s_odropped);
 238                         return (ENOBUFS);
 239                 }
 240                 m->m_flags = m0->m_flags & M_COPYFLAGS;
 241                 *mnext = m;
 242                 mnext = &m->m_nextpkt;
 243                 m->m_data += max_linkhdr;
 244                 mhip6 = mtod(m, struct ip6_hdr *);
 245                 *mhip6 = *ip6;
 246                 m->m_len = sizeof(*mhip6);
 247                 error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
 248                 if (error) {
 249                         IP6STAT_INC(ip6s_odropped);
 250                         return (error);
 251                 }
 252                 ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
 253                 if (off + mtu >= tlen)
 254                         mtu = tlen - off;
 255                 else
 256                         ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
 257                 mhip6->ip6_plen = htons((u_short)(mtu + hlen +
 258                     sizeof(*ip6f) - sizeof(struct ip6_hdr)));
 259                 if ((m_frgpart = m_copy(m0, off, mtu)) == 0) {
 260                         IP6STAT_INC(ip6s_odropped);
 261                         return (ENOBUFS);
 262                 }
 263                 m_cat(m, m_frgpart);
 264                 m->m_pkthdr.len = mtu + hlen + sizeof(*ip6f);
 265                 m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
 266                 m->m_pkthdr.rcvif = NULL;
 267                 ip6f->ip6f_reserved = 0;
 268                 ip6f->ip6f_ident = id;
 269                 ip6f->ip6f_nxt = nextproto;
 270                 IP6STAT_INC(ip6s_ofragments);
 271                 in6_ifstat_inc(ifp, ifs6_out_fragcreat);
 272         }
 273
 274         return (0);
 275 }
 276
 277 /*
 278  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 279  * header (with pri, len, nxt, hlim, src, dst).
 280  * This function may modify ver and hlim only.
 281  * The mbuf chain containing the packet will be freed.
 282  * The mbuf opt, if present, will not be freed.
 283  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
 284  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
 285  * then result of route lookup is stored in ro->ro_rt.
 286  *
 287  * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
 288  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 289  * which is rt_mtu.
 290  *
 291  * ifpp - XXX: just for statistics
 292  */
 293 /*
 294  * XXX TODO: no flowid is assigned for outbound flows?
 295  */
 296 int
 297 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 298     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 299     struct ifnet **ifpp, struct inpcb *inp)
 300 {
 301         struct ip6_hdr *ip6;
 302         struct ifnet *ifp, *origifp;
 303         struct mbuf *m = m0;
 304         struct mbuf *mprev = NULL;
 305         int hlen, tlen, len;
 306         struct route_in6 ip6route;
 307         struct rtentry *rt = NULL;
 308         struct sockaddr_in6 *dst, src_sa, dst_sa;
 309         struct in6_addr odst;
 310         int error = 0;
 311         struct in6_ifaddr *ia = NULL;
 312         u_long mtu;
 313         int alwaysfrag, dontfrag;
 314         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 315         struct ip6_exthdrs exthdrs;
 316         struct in6_addr finaldst, src0, dst0;
 317         u_int32_t zone;
 318         struct route_in6 *ro_pmtu = NULL;
 319         int hdrsplit = 0;
 320         int sw_csum, tso;
 321         int needfiblookup;
 322         uint32_t fibnum;
 323         struct m_tag *fwd_tag = NULL;
 324         uint32_t id;
 325
 326         ip6 = mtod(m, struct ip6_hdr *);
 327         if (ip6 == NULL) {
 328                 printf ("ip6 is NULL");
 329                 goto bad;
 330         }
 331
 332         if (inp != NULL) {
 333                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
 334                 if ((flags & IP_NODEFAULTFLOWID) == 0) {
 335                         /* unconditionally set flowid */
 336                         m->m_pkthdr.flowid = inp->inp_flowid;
 337                         M_HASHTYPE_SET(m, inp->inp_flowtype);
 338                 }
 339         }
 340
 341         finaldst = ip6->ip6_dst;
 342         bzero(&exthdrs, sizeof(exthdrs));
 343         if (opt) {
 344                 /* Hop-by-Hop options header */
 345                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 346                 /* Destination options header(1st part) */
 347                 if (opt->ip6po_rthdr) {
 348                         /*
 349                          * Destination options header(1st part)
 350                          * This only makes sense with a routing header.
 351                          * See Section 9.2 of RFC 3542.
 352                          * Disabling this part just for MIP6 convenience is
 353                          * a bad idea.  We need to think carefully about a
 354                          * way to make the advanced API coexist with MIP6
 355                          * options, which might automatically be inserted in
 356                          * the kernel.
 357                          */
 358                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 359                 }
 360                 /* Routing header */
 361                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 362                 /* Destination options header(2nd part) */
 363                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 364         }
 365
 366 #ifdef IPSEC
 367         /*
 368          * IPSec checking which handles several cases.
 369          * FAST IPSEC: We re-injected the packet.
 370          * XXX: need scope argument.
 371          */
 372         switch(ip6_ipsec_output(&m, inp, &error))
 373         {
 374         case 1:                 /* Bad packet */
 375                 goto freehdrs;
 376         case -1:                /* IPSec done */
 377                 goto done;
 378         case 0:                 /* No IPSec */
 379         default:
 380                 break;
 381         }
 382 #endif /* IPSEC */
 383
 384         /*
 385          * Calculate the total length of the extension header chain.
 386          * Keep the length of the unfragmentable part for fragmentation.
 387          */
 388         optlen = 0;
 389         if (exthdrs.ip6e_hbh)
 390                 optlen += exthdrs.ip6e_hbh->m_len;
 391         if (exthdrs.ip6e_dest1)
 392                 optlen += exthdrs.ip6e_dest1->m_len;
 393         if (exthdrs.ip6e_rthdr)
 394                 optlen += exthdrs.ip6e_rthdr->m_len;
 395         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 396
 397         /* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
 398         if (exthdrs.ip6e_dest2)
 399                 optlen += exthdrs.ip6e_dest2->m_len;
 400
 401         /*
 402          * If there is at least one extension header,
 403          * separate IP6 header from the payload.
 404          */
 405         if (optlen && !hdrsplit) {
 406                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 407                         m = NULL;
 408                         goto freehdrs;
 409                 }
 410                 m = exthdrs.ip6e_ip6;
 411                 hdrsplit++;
 412         }
 413
 414         /* adjust pointer */
 415         ip6 = mtod(m, struct ip6_hdr *);
 416
 417         /* adjust mbuf packet header length */
 418         m->m_pkthdr.len += optlen;
 419         plen = m->m_pkthdr.len - sizeof(*ip6);
 420
 421         /* If this is a jumbo payload, insert a jumbo payload option. */
 422         if (plen > IPV6_MAXPACKET) {
 423                 if (!hdrsplit) {
 424                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 425                                 m = NULL;
 426                                 goto freehdrs;
 427                         }
 428                         m = exthdrs.ip6e_ip6;
 429                         hdrsplit++;
 430                 }
 431                 /* adjust pointer */
 432                 ip6 = mtod(m, struct ip6_hdr *);
 433                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 434                         goto freehdrs;
 435                 ip6->ip6_plen = 0;
 436         } else
 437                 ip6->ip6_plen = htons(plen);
 438
 439         /*
 440          * Concatenate headers and fill in next header fields.
 441          * Here we have, on "m"
 442          *      IPv6 payload
 443          * and we insert headers accordingly.  Finally, we should be getting:
 444          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 445          *
 446          * during the header composing process, "m" points to IPv6 header.
 447          * "mprev" points to an extension header prior to esp.
 448          */
 449         u_char *nexthdrp = &ip6->ip6_nxt;
 450         mprev = m;
 451
 452         /*
 453          * we treat dest2 specially.  this makes IPsec processing
 454          * much easier.  the goal here is to make mprev point the
 455          * mbuf prior to dest2.
 456          *
 457          * result: IPv6 dest2 payload
 458          * m and mprev will point to IPv6 header.
 459          */
 460         if (exthdrs.ip6e_dest2) {
 461                 if (!hdrsplit)
 462                         panic("assumption failed: hdr not split");
 463                 exthdrs.ip6e_dest2->m_next = m->m_next;
 464                 m->m_next = exthdrs.ip6e_dest2;
 465                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 466                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 467         }
 468
 469         /*
 470          * result: IPv6 hbh dest1 rthdr dest2 payload
 471          * m will point to IPv6 header.  mprev will point to the
 472          * extension header prior to dest2 (rthdr in the above case).
 473          */
 474         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 475         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 476                    IPPROTO_DSTOPTS);
 477         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 478                    IPPROTO_ROUTING);
 479
 480         /*
 481          * If there is a routing header, discard the packet.
 482          */
 483         if (exthdrs.ip6e_rthdr) {
 484                  error = EINVAL;
 485                  goto bad;
 486         }
 487
 488         /* Source address validation */
 489         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 490             (flags & IPV6_UNSPECSRC) == 0) {
 491                 error = EOPNOTSUPP;
 492                 IP6STAT_INC(ip6s_badscope);
 493                 goto bad;
 494         }
 495         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 496                 error = EOPNOTSUPP;
 497                 IP6STAT_INC(ip6s_badscope);
 498                 goto bad;
 499         }
 500
 501         IP6STAT_INC(ip6s_localout);
 502
 503         /*
 504          * Route packet.
 505          */
 506         if (ro == 0) {
 507                 ro = &ip6route;
 508                 bzero((caddr_t)ro, sizeof(*ro));
 509         }
 510         ro_pmtu = ro;
 511         if (opt && opt->ip6po_rthdr)
 512                 ro = &opt->ip6po_route;
 513         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 514 #ifdef FLOWTABLE
 515         if (ro->ro_rt == NULL)
 516                 (void )flowtable_lookup(AF_INET6, m, (struct route *)ro);
 517 #endif
 518         fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
 519 again:
 520         /*
 521          * if specified, try to fill in the traffic class field.
 522          * do not override if a non-zero value is already set.
 523          * we check the diffserv field and the ecn field separately.
 524          */
 525         if (opt && opt->ip6po_tclass >= 0) {
 526                 int mask = 0;
 527
 528                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 529                         mask |= 0xfc;
 530                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 531                         mask |= 0x03;
 532                 if (mask != 0)
 533                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 534         }
 535
 536         /* fill in or override the hop limit field, if necessary. */
 537         if (opt && opt->ip6po_hlim != -1)
 538                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 539         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 540                 if (im6o != NULL)
 541                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 542                 else
 543                         ip6->ip6_hlim = V_ip6_defmcasthlim;
 544         }
 545
 546         /* adjust pointer */
 547         ip6 = mtod(m, struct ip6_hdr *);
 548
 549         if (ro->ro_rt && fwd_tag == NULL) {
 550                 rt = ro->ro_rt;
 551                 ifp = ro->ro_rt->rt_ifp;
 552         } else {
 553                 if (fwd_tag == NULL) {
 554                         bzero(&dst_sa, sizeof(dst_sa));
 555                         dst_sa.sin6_family = AF_INET6;
 556                         dst_sa.sin6_len = sizeof(dst_sa);
 557                         dst_sa.sin6_addr = ip6->ip6_dst;
 558                 }
 559                 error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
 560                     &rt, fibnum);
 561                 if (error != 0) {
 562                         if (ifp != NULL)
 563                                 in6_ifstat_inc(ifp, ifs6_out_discard);
 564                         goto bad;
 565                 }
 566         }
 567         if (rt == NULL) {
 568                 /*
 569                  * If in6_selectroute() does not return a route entry,
 570                  * dst may not have been updated.
 571                  */
 572                 *dst = dst_sa;  /* XXX */
 573         }
 574
 575         /*
 576          * then rt (for unicast) and ifp must be non-NULL valid values.
 577          */
 578         if ((flags & IPV6_FORWARDING) == 0) {
 579                 /* XXX: the FORWARDING flag can be set for mrouting. */
 580                 in6_ifstat_inc(ifp, ifs6_out_request);
 581         }
 582         if (rt != NULL) {
 583                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 584                 counter_u64_add(rt->rt_pksent, 1);
 585         }
 586
 587
 588         /*
 589          * The outgoing interface must be in the zone of source and
 590          * destination addresses.
 591          */
 592         origifp = ifp;
 593
 594         src0 = ip6->ip6_src;
 595         if (in6_setscope(&src0, origifp, &zone))
 596                 goto badscope;
 597         bzero(&src_sa, sizeof(src_sa));
 598         src_sa.sin6_family = AF_INET6;
 599         src_sa.sin6_len = sizeof(src_sa);
 600         src_sa.sin6_addr = ip6->ip6_src;
 601         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 602                 goto badscope;
 603
 604         dst0 = ip6->ip6_dst;
 605         if (in6_setscope(&dst0, origifp, &zone))
 606                 goto badscope;
 607         /* re-initialize to be sure */
 608         bzero(&dst_sa, sizeof(dst_sa));
 609         dst_sa.sin6_family = AF_INET6;
 610         dst_sa.sin6_len = sizeof(dst_sa);
 611         dst_sa.sin6_addr = ip6->ip6_dst;
 612         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 613                 goto badscope;
 614         }
 615
 616         /* We should use ia_ifp to support the case of
 617          * sending packets to an address of our own.
 618          */
 619         if (ia != NULL && ia->ia_ifp)
 620                 ifp = ia->ia_ifp;
 621
 622         /* scope check is done. */
 623         goto routefound;
 624
 625   badscope:
 626         IP6STAT_INC(ip6s_badscope);
 627         in6_ifstat_inc(origifp, ifs6_out_discard);
 628         if (error == 0)
 629                 error = EHOSTUNREACH; /* XXX */
 630         goto bad;
 631
 632   routefound:
 633         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 634                 if (opt && opt->ip6po_nextroute.ro_rt) {
 635                         /*
 636                          * The nexthop is explicitly specified by the
 637                          * application.  We assume the next hop is an IPv6
 638                          * address.
 639                          */
 640                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 641                 }
 642                 else if ((rt->rt_flags & RTF_GATEWAY))
 643                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 644         }
 645
 646         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 647                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 648         } else {
 649                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 650                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 651                 /*
 652                  * Confirm that the outgoing interface supports multicast.
 653                  */
 654                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 655                         IP6STAT_INC(ip6s_noroute);
 656                         in6_ifstat_inc(ifp, ifs6_out_discard);
 657                         error = ENETUNREACH;
 658                         goto bad;
 659                 }
 660                 if ((im6o == NULL && in6_mcast_loop) ||
 661                     (im6o && im6o->im6o_multicast_loop)) {
 662                         /*
 663                          * Loop back multicast datagram if not expressly
 664                          * forbidden to do so, even if we have not joined
 665                          * the address; protocols will filter it later,
 666                          * thus deferring a hash lookup and lock acquisition
 667                          * at the expense of an m_copym().
 668                          */
 669                         ip6_mloopback(ifp, m);
 670                 } else {
 671                         /*
 672                          * If we are acting as a multicast router, perform
 673                          * multicast forwarding as if the packet had just
 674                          * arrived on the interface to which we are about
 675                          * to send.  The multicast forwarding function
 676                          * recursively calls this function, using the
 677                          * IPV6_FORWARDING flag to prevent infinite recursion.
 678                          *
 679                          * Multicasts that are looped back by ip6_mloopback(),
 680                          * above, will be forwarded by the ip6_input() routine,
 681                          * if necessary.
 682                          */
 683                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 684                                 /*
 685                                  * XXX: ip6_mforward expects that rcvif is NULL
 686                                  * when it is called from the originating path.
 687                                  * However, it may not always be the case.
 688                                  */
 689                                 m->m_pkthdr.rcvif = NULL;
 690                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 691                                         m_freem(m);
 692                                         goto done;
 693                                 }
 694                         }
 695                 }
 696                 /*
 697                  * Multicasts with a hoplimit of zero may be looped back,
 698                  * above, but must not be transmitted on a network.
 699                  * Also, multicasts addressed to the loopback interface
 700                  * are not sent -- the above call to ip6_mloopback() will
 701                  * loop back a copy if this host actually belongs to the
 702                  * destination group on the loopback interface.
 703                  */
 704                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 705                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 706                         m_freem(m);
 707                         goto done;
 708                 }
 709         }
 710
 711         /*
 712          * Fill the outgoing inteface to tell the upper layer
 713          * to increment per-interface statistics.
 714          */
 715         if (ifpp)
 716                 *ifpp = ifp;
 717
 718         /* Determine path MTU. */
 719         if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &finaldst, &mtu,
 720             &alwaysfrag, fibnum)) != 0)
 721                 goto bad;
 722
 723         /*
 724          * The caller of this function may specify to use the minimum MTU
 725          * in some cases.
 726          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 727          * setting.  The logic is a bit complicated; by default, unicast
 728          * packets will follow path MTU while multicast packets will be sent at
 729          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 730          * including unicast ones will be sent at the minimum MTU.  Multicast
 731          * packets will always be sent at the minimum MTU unless
 732          * IP6PO_MINMTU_DISABLE is explicitly specified.
 733          * See RFC 3542 for more details.
 734          */
 735         if (mtu > IPV6_MMTU) {
 736                 if ((flags & IPV6_MINMTU))
 737                         mtu = IPV6_MMTU;
 738                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 739                         mtu = IPV6_MMTU;
 740                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 741                          (opt == NULL ||
 742                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 743                         mtu = IPV6_MMTU;
 744                 }
 745         }
 746
 747         /*
 748          * clear embedded scope identifiers if necessary.
 749          * in6_clearscope will touch the addresses only when necessary.
 750          */
 751         in6_clearscope(&ip6->ip6_src);
 752         in6_clearscope(&ip6->ip6_dst);
 753
 754         /*
 755          * If the outgoing packet contains a hop-by-hop options header,
 756          * it must be examined and processed even by the source node.
 757          * (RFC 2460, section 4.)
 758          */
 759         if (exthdrs.ip6e_hbh) {
 760                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 761                 u_int32_t dummy; /* XXX unused */
 762                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 763
 764 #ifdef DIAGNOSTIC
 765                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 766                         panic("ip6e_hbh is not contiguous");
 767 #endif
 768                 /*
 769                  *  XXX: if we have to send an ICMPv6 error to the sender,
 770                  *       we need the M_LOOP flag since icmp6_error() expects
 771                  *       the IPv6 and the hop-by-hop options header are
 772                  *       contiguous unless the flag is set.
 773                  */
 774                 m->m_flags |= M_LOOP;
 775                 m->m_pkthdr.rcvif = ifp;
 776                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 777                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 778                     &dummy, &plen) < 0) {
 779                         /* m was already freed at this point */
 780                         error = EINVAL;/* better error? */
 781                         goto done;
 782                 }
 783                 m->m_flags &= ~M_LOOP; /* XXX */
 784                 m->m_pkthdr.rcvif = NULL;
 785         }
 786
 787         /* Jump over all PFIL processing if hooks are not active. */
 788         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
 789                 goto passout;
 790
 791         odst = ip6->ip6_dst;
 792         /* Run through list of hooks for output packets. */
 793         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 794         if (error != 0 || m == NULL)
 795                 goto done;
 796         ip6 = mtod(m, struct ip6_hdr *);
 797
 798         needfiblookup = 0;
 799         /* See if destination IP address was changed by packet filter. */
 800         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 801                 m->m_flags |= M_SKIP_FIREWALL;
 802                 /* If destination is now ourself drop to ip6_input(). */
 803                 if (in6_localip(&ip6->ip6_dst)) {
 804                         m->m_flags |= M_FASTFWD_OURS;
 805                         if (m->m_pkthdr.rcvif == NULL)
 806                                 m->m_pkthdr.rcvif = V_loif;
 807                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 808                                 m->m_pkthdr.csum_flags |=
 809                                     CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 810                                 m->m_pkthdr.csum_data = 0xffff;
 811                         }
 812 #ifdef SCTP
 813                         if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 814                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 815 #endif
 816                         error = netisr_queue(NETISR_IPV6, m);
 817                         goto done;
 818                 } else
 819                         needfiblookup = 1; /* Redo the routing table lookup. */
 820         }
 821         /* See if fib was changed by packet filter. */
 822         if (fibnum != M_GETFIB(m)) {
 823                 m->m_flags |= M_SKIP_FIREWALL;
 824                 fibnum = M_GETFIB(m);
 825                 RO_RTFREE(ro);
 826                 needfiblookup = 1;
 827         }
 828         if (needfiblookup)
 829                 goto again;
 830
 831         /* See if local, if yes, send it to netisr. */
 832         if (m->m_flags & M_FASTFWD_OURS) {
 833                 if (m->m_pkthdr.rcvif == NULL)
 834                         m->m_pkthdr.rcvif = V_loif;
 835                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 836                         m->m_pkthdr.csum_flags |=
 837                             CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 838                         m->m_pkthdr.csum_data = 0xffff;
 839                 }
 840 #ifdef SCTP
 841                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 842                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 843 #endif
 844                 error = netisr_queue(NETISR_IPV6, m);
 845                 goto done;
 846         }
 847         /* Or forward to some other address? */
 848         if ((m->m_flags & M_IP6_NEXTHOP) &&
 849             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 850                 dst = (struct sockaddr_in6 *)&ro->ro_dst;
 851                 bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
 852                 m->m_flags |= M_SKIP_FIREWALL;
 853                 m->m_flags &= ~M_IP6_NEXTHOP;
 854                 m_tag_delete(m, fwd_tag);
 855                 goto again;
 856         }
 857
 858 passout:
 859         /*
 860          * Send the packet to the outgoing interface.
 861          * If necessary, do IPv6 fragmentation before sending.
 862          *
 863          * the logic here is rather complex:
 864          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 865          * 1-a: send as is if tlen <= path mtu
 866          * 1-b: fragment if tlen > path mtu
 867          *
 868          * 2: if user asks us not to fragment (dontfrag == 1)
 869          * 2-a: send as is if tlen <= interface mtu
 870          * 2-b: error if tlen > interface mtu
 871          *
 872          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 873          *      always fragment
 874          *
 875          * 4: if dontfrag == 1 && alwaysfrag == 1
 876          *      error, as we cannot handle this conflicting request
 877          */
 878         sw_csum = m->m_pkthdr.csum_flags;
 879         if (!hdrsplit) {
 880                 tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
 881                 sw_csum &= ~ifp->if_hwassist;
 882         } else
 883                 tso = 0;
 884         /*
 885          * If we added extension headers, we will not do TSO and calculate the
 886          * checksums ourselves for now.
 887          * XXX-BZ  Need a framework to know when the NIC can handle it, even
 888          * with ext. hdrs.
 889          */
 890         if (sw_csum & CSUM_DELAY_DATA_IPV6) {
 891                 sw_csum &= ~CSUM_DELAY_DATA_IPV6;
 892                 in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
 893         }
 894 #ifdef SCTP
 895         if (sw_csum & CSUM_SCTP_IPV6) {
 896                 sw_csum &= ~CSUM_SCTP_IPV6;
 897                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 898         }
 899 #endif
 900         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
 901         tlen = m->m_pkthdr.len;
 902
 903         if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
 904                 dontfrag = 1;
 905         else
 906                 dontfrag = 0;
 907         if (dontfrag && alwaysfrag) {   /* case 4 */
 908                 /* conflicting request - can't transmit */
 909                 error = EMSGSIZE;
 910                 goto bad;
 911         }
 912         if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {      /* case 2-b */
 913                 /*
 914                  * Even if the DONTFRAG option is specified, we cannot send the
 915                  * packet when the data length is larger than the MTU of the
 916                  * outgoing interface.
 917                  * Notify the error by sending IPV6_PATHMTU ancillary data if
 918                  * application wanted to know the MTU value. Also return an
 919                  * error code (this is not described in the API spec).
 920                  */
 921                 if (inp != NULL)
 922                         ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
 923                 error = EMSGSIZE;
 924                 goto bad;
 925         }
 926
 927         /*
 928          * transmit packet without fragmentation
 929          */
 930         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 931                 struct in6_ifaddr *ia6;
 932
 933                 ip6 = mtod(m, struct ip6_hdr *);
 934                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 935                 if (ia6) {
 936                         /* Record statistics for this interface address. */
 937                         counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
 938                         counter_u64_add(ia6->ia_ifa.ifa_obytes,
 939                             m->m_pkthdr.len);
 940                         ifa_free(&ia6->ia_ifa);
 941                 }
 942                 error = nd6_output_ifp(ifp, origifp, m, dst, NULL);
 943                 goto done;
 944         }
 945
 946         /*
 947          * try to fragment the packet.  case 1-b and 3
 948          */
 949         if (mtu < IPV6_MMTU) {
 950                 /* path MTU cannot be less than IPV6_MMTU */
 951                 error = EMSGSIZE;
 952                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 953                 goto bad;
 954         } else if (ip6->ip6_plen == 0) {
 955                 /* jumbo payload cannot be fragmented */
 956                 error = EMSGSIZE;
 957                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 958                 goto bad;
 959         } else {
 960                 u_char nextproto;
 961
 962                 /*
 963                  * Too large for the destination or interface;
 964                  * fragment if possible.
 965                  * Must be able to put at least 8 bytes per fragment.
 966                  */
 967                 hlen = unfragpartlen;
 968                 if (mtu > IPV6_MAXPACKET)
 969                         mtu = IPV6_MAXPACKET;
 970
 971                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 972                 if (len < 8) {
 973                         error = EMSGSIZE;
 974                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
 975                         goto bad;
 976                 }
 977
 978                 /*
 979                  * If the interface will not calculate checksums on
 980                  * fragmented packets, then do it here.
 981                  * XXX-BZ handle the hw offloading case.  Need flags.
 982                  */
 983                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 984                         in6_delayed_cksum(m, plen, hlen);
 985                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
 986                 }
 987 #ifdef SCTP
 988                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
 989                         sctp_delayed_cksum(m, hlen);
 990                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
 991                 }
 992 #endif
 993                 /*
 994                  * Change the next header field of the last header in the
 995                  * unfragmentable part.
 996                  */
 997                 if (exthdrs.ip6e_rthdr) {
 998                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
 999                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1000                 } else if (exthdrs.ip6e_dest1) {
1001                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1002                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1003                 } else if (exthdrs.ip6e_hbh) {
1004                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1005                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1006                 } else {
1007                         nextproto = ip6->ip6_nxt;
1008                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
1009                 }
1010
1011                 /*
1012                  * Loop through length of segment after first fragment,
1013                  * make new header and copy data of each part and link onto
1014                  * chain.
1015                  */
1016                 m0 = m;
1017                 id = htonl(ip6_randomid());
1018                 if ((error = ip6_fragment(ifp, m, hlen, nextproto, len, id)))
1019                         goto sendorfree;
1020
1021                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1022         }
1023
1024         /*
1025          * Remove leading garbages.
1026          */
1027 sendorfree:
1028         m = m0->m_nextpkt;
1029         m0->m_nextpkt = 0;
1030         m_freem(m0);
1031         for (m0 = m; m; m = m0) {
1032                 m0 = m->m_nextpkt;
1033                 m->m_nextpkt = 0;
1034                 if (error == 0) {
1035                         /* Record statistics for this interface address. */
1036                         if (ia) {
1037                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1038                                 counter_u64_add(ia->ia_ifa.ifa_obytes,
1039                                     m->m_pkthdr.len);
1040                         }
1041                         error = nd6_output_ifp(ifp, origifp, m, dst, NULL);
1042                 } else
1043                         m_freem(m);
1044         }
1045
1046         if (error == 0)
1047                 IP6STAT_INC(ip6s_fragmented);
1048
1049 done:
1050         if (ro == &ip6route)
1051                 RO_RTFREE(ro);
1052         return (error);
1053
1054 freehdrs:
1055         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1056         m_freem(exthdrs.ip6e_dest1);
1057         m_freem(exthdrs.ip6e_rthdr);
1058         m_freem(exthdrs.ip6e_dest2);
1059         /* FALLTHROUGH */
1060 bad:
1061         if (m)
1062                 m_freem(m);
1063         goto done;
1064 }
1065
1066 static int
1067 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1068 {
1069         struct mbuf *m;
1070
1071         if (hlen > MCLBYTES)
1072                 return (ENOBUFS); /* XXX */
1073
1074         if (hlen > MLEN)
1075                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1076         else
1077                 m = m_get(M_NOWAIT, MT_DATA);
1078         if (m == NULL)
1079                 return (ENOBUFS);
1080         m->m_len = hlen;
1081         if (hdr)
1082                 bcopy(hdr, mtod(m, caddr_t), hlen);
1083
1084         *mp = m;
1085         return (0);
1086 }
1087
1088 /*
1089  * Insert jumbo payload option.
1090  */
1091 static int
1092 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1093 {
1094         struct mbuf *mopt;
1095         u_char *optbuf;
1096         u_int32_t v;
1097
1098 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1099
1100         /*
1101          * If there is no hop-by-hop options header, allocate new one.
1102          * If there is one but it doesn't have enough space to store the
1103          * jumbo payload option, allocate a cluster to store the whole options.
1104          * Otherwise, use it to store the options.
1105          */
1106         if (exthdrs->ip6e_hbh == 0) {
1107                 mopt = m_get(M_NOWAIT, MT_DATA);
1108                 if (mopt == NULL)
1109                         return (ENOBUFS);
1110                 mopt->m_len = JUMBOOPTLEN;
1111                 optbuf = mtod(mopt, u_char *);
1112                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1113                 exthdrs->ip6e_hbh = mopt;
1114         } else {
1115                 struct ip6_hbh *hbh;
1116
1117                 mopt = exthdrs->ip6e_hbh;
1118                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1119                         /*
1120                          * XXX assumption:
1121                          * - exthdrs->ip6e_hbh is not referenced from places
1122                          *   other than exthdrs.
1123                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1124                          */
1125                         int oldoptlen = mopt->m_len;
1126                         struct mbuf *n;
1127
1128                         /*
1129                          * XXX: give up if the whole (new) hbh header does
1130                          * not fit even in an mbuf cluster.
1131                          */
1132                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1133                                 return (ENOBUFS);
1134
1135                         /*
1136                          * As a consequence, we must always prepare a cluster
1137                          * at this point.
1138                          */
1139                         n = m_getcl(M_NOWAIT, MT_DATA, 0);
1140                         if (n == NULL)
1141                                 return (ENOBUFS);
1142                         n->m_len = oldoptlen + JUMBOOPTLEN;
1143                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1144                             oldoptlen);
1145                         optbuf = mtod(n, caddr_t) + oldoptlen;
1146                         m_freem(mopt);
1147                         mopt = exthdrs->ip6e_hbh = n;
1148                 } else {
1149                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1150                         mopt->m_len += JUMBOOPTLEN;
1151                 }
1152                 optbuf[0] = IP6OPT_PADN;
1153                 optbuf[1] = 1;
1154
1155                 /*
1156                  * Adjust the header length according to the pad and
1157                  * the jumbo payload option.
1158                  */
1159                 hbh = mtod(mopt, struct ip6_hbh *);
1160                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1161         }
1162
1163         /* fill in the option. */
1164         optbuf[2] = IP6OPT_JUMBO;
1165         optbuf[3] = 4;
1166         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1167         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1168
1169         /* finally, adjust the packet header length */
1170         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1171
1172         return (0);
1173 #undef JUMBOOPTLEN
1174 }
1175
1176 /*
1177  * Insert fragment header and copy unfragmentable header portions.
1178  */
1179 static int
1180 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1181     struct ip6_frag **frghdrp)
1182 {
1183         struct mbuf *n, *mlast;
1184
1185         if (hlen > sizeof(struct ip6_hdr)) {
1186                 n = m_copym(m0, sizeof(struct ip6_hdr),
1187                     hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1188                 if (n == 0)
1189                         return (ENOBUFS);
1190                 m->m_next = n;
1191         } else
1192                 n = m;
1193
1194         /* Search for the last mbuf of unfragmentable part. */
1195         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1196                 ;
1197
1198         if (M_WRITABLE(mlast) &&
1199             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1200                 /* use the trailing space of the last mbuf for the fragment hdr */
1201                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1202                     mlast->m_len);
1203                 mlast->m_len += sizeof(struct ip6_frag);
1204                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1205         } else {
1206                 /* allocate a new mbuf for the fragment header */
1207                 struct mbuf *mfrg;
1208
1209                 mfrg = m_get(M_NOWAIT, MT_DATA);
1210                 if (mfrg == NULL)
1211                         return (ENOBUFS);
1212                 mfrg->m_len = sizeof(struct ip6_frag);
1213                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1214                 mlast->m_next = mfrg;
1215         }
1216
1217         return (0);
1218 }
1219
1220 /*
1221  * Calculates IPv6 path mtu for destination @dst.
1222  * Resulting MTU is stored in @mtup.
1223  *
1224  * Returns 0 on success.
1225  */
1226 static int
1227 ip6_getpmtu_ctl(u_int fibnum, struct in6_addr *dst, u_long *mtup)
1228 {
1229         struct nhop6_extended nh6;
1230         struct in6_addr kdst;
1231         uint32_t scopeid;
1232         struct ifnet *ifp;
1233         u_long mtu;
1234         int error;
1235
1236         in6_splitscope(dst, &kdst, &scopeid);
1237         if (fib6_lookup_nh_ext(fibnum, &kdst, scopeid, NHR_REF, 0, &nh6) != 0)
1238                 return (EHOSTUNREACH);
1239
1240         ifp = nh6.nh_ifp;
1241         mtu = nh6.nh_mtu;
1242
1243         error = ip6_calcmtu(ifp, dst, mtu, mtup, NULL);
1244         fib6_free_nh_ext(fibnum, &nh6);
1245
1246         return (error);
1247 }
1248
1249 /*
1250  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1251  * and cached data in @ro_pmtu.
1252  * MTU from (successful) route lookup is saved (along with dst)
1253  * inside @ro_pmtu to avoid subsequent route lookups after packet
1254  * filter processing.
1255  *
1256  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1257  * Returns 0 on success.
1258  */
1259 static int
1260 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1261     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1262     int *alwaysfragp, u_int fibnum)
1263 {
1264         struct nhop6_basic nh6;
1265         struct in6_addr kdst;
1266         uint32_t scopeid;
1267         struct sockaddr_in6 *sa6_dst;
1268         u_long mtu;
1269
1270         mtu = 0;
1271         if (do_lookup) {
1272
1273                 /*
1274                  * Here ro_pmtu has final destination address, while
1275                  * ro might represent immediate destination.
1276                  * Use ro_pmtu destination since mtu might differ.
1277                  */
1278                 sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1279                 if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1280                         ro_pmtu->ro_mtu = 0;
1281
1282                 if (ro_pmtu->ro_mtu == 0) {
1283                         bzero(sa6_dst, sizeof(*sa6_dst));
1284                         sa6_dst->sin6_family = AF_INET6;
1285                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1286                         sa6_dst->sin6_addr = *dst;
1287
1288                         in6_splitscope(dst, &kdst, &scopeid);
1289                         if (fib6_lookup_nh_basic(fibnum, &kdst, scopeid, 0, 0,
1290                             &nh6) == 0)
1291                                 ro_pmtu->ro_mtu = nh6.nh_mtu;
1292                 }
1293
1294                 mtu = ro_pmtu->ro_mtu;
1295         }
1296
1297         if (ro_pmtu->ro_rt)
1298                 mtu = ro_pmtu->ro_rt->rt_mtu;
1299
1300         return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp));
1301 }
1302
1303 /*
1304  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1305  * hostcache data for @dst.
1306  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1307  *
1308  * Returns 0 on success.
1309  */
1310 static int
1311 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1312     u_long *mtup, int *alwaysfragp)
1313 {
1314         u_long mtu = 0;
1315         int alwaysfrag = 0;
1316         int error = 0;
1317
1318         if (rt_mtu > 0) {
1319                 u_int32_t ifmtu;
1320                 struct in_conninfo inc;
1321
1322                 bzero(&inc, sizeof(inc));
1323                 inc.inc_flags |= INC_ISIPV6;
1324                 inc.inc6_faddr = *dst;
1325
1326                 ifmtu = IN6_LINKMTU(ifp);
1327                 mtu = tcp_hc_getmtu(&inc);
1328                 if (mtu)
1329                         mtu = min(mtu, rt_mtu);
1330                 else
1331                         mtu = rt_mtu;
1332                 if (mtu == 0)
1333                         mtu = ifmtu;
1334                 else if (mtu < IPV6_MMTU) {
1335                         /*
1336                          * RFC2460 section 5, last paragraph:
1337                          * if we record ICMPv6 too big message with
1338                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1339                          * or smaller, with framgent header attached.
1340                          * (fragment header is needed regardless from the
1341                          * packet size, for translators to identify packets)
1342                          */
1343                         alwaysfrag = 1;
1344                         mtu = IPV6_MMTU;
1345                 }
1346         } else if (ifp) {
1347                 mtu = IN6_LINKMTU(ifp);
1348         } else
1349                 error = EHOSTUNREACH; /* XXX */
1350
1351         *mtup = mtu;
1352         if (alwaysfragp)
1353                 *alwaysfragp = alwaysfrag;
1354         return (error);
1355 }
1356
1357 /*
1358  * IP6 socket option processing.
1359  */
1360 int
1361 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1362 {
1363         int optdatalen, uproto;
1364         void *optdata;
1365         struct inpcb *in6p = sotoinpcb(so);
1366         int error, optval;
1367         int level, op, optname;
1368         int optlen;
1369         struct thread *td;
1370 #ifdef  RSS
1371         uint32_t rss_bucket;
1372         int retval;
1373 #endif
1374
1375         level = sopt->sopt_level;
1376         op = sopt->sopt_dir;
1377         optname = sopt->sopt_name;
1378         optlen = sopt->sopt_valsize;
1379         td = sopt->sopt_td;
1380         error = 0;
1381         optval = 0;
1382         uproto = (int)so->so_proto->pr_protocol;
1383
1384         if (level != IPPROTO_IPV6) {
1385                 error = EINVAL;
1386
1387                 if (sopt->sopt_level == SOL_SOCKET &&
1388                     sopt->sopt_dir == SOPT_SET) {
1389                         switch (sopt->sopt_name) {
1390                         case SO_REUSEADDR:
1391                                 INP_WLOCK(in6p);
1392                                 if ((so->so_options & SO_REUSEADDR) != 0)
1393                                         in6p->inp_flags2 |= INP_REUSEADDR;
1394                                 else
1395                                         in6p->inp_flags2 &= ~INP_REUSEADDR;
1396                                 INP_WUNLOCK(in6p);
1397                                 error = 0;
1398                                 break;
1399                         case SO_REUSEPORT:
1400                                 INP_WLOCK(in6p);
1401                                 if ((so->so_options & SO_REUSEPORT) != 0)
1402                                         in6p->inp_flags2 |= INP_REUSEPORT;
1403                                 else
1404                                         in6p->inp_flags2 &= ~INP_REUSEPORT;
1405                                 INP_WUNLOCK(in6p);
1406                                 error = 0;
1407                                 break;
1408                         case SO_SETFIB:
1409                                 INP_WLOCK(in6p);
1410                                 in6p->inp_inc.inc_fibnum = so->so_fibnum;
1411                                 INP_WUNLOCK(in6p);
1412                                 error = 0;
1413                                 break;
1414                         default:
1415                                 break;
1416                         }
1417                 }
1418         } else {                /* level == IPPROTO_IPV6 */
1419                 switch (op) {
1420
1421                 case SOPT_SET:
1422                         switch (optname) {
1423                         case IPV6_2292PKTOPTIONS:
1424 #ifdef IPV6_PKTOPTIONS
1425                         case IPV6_PKTOPTIONS:
1426 #endif
1427                         {
1428                                 struct mbuf *m;
1429
1430                                 error = soopt_getm(sopt, &m); /* XXX */
1431                                 if (error != 0)
1432                                         break;
1433                                 error = soopt_mcopyin(sopt, m); /* XXX */
1434                                 if (error != 0)
1435                                         break;
1436                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1437                                                     m, so, sopt);
1438                                 m_freem(m); /* XXX */
1439                                 break;
1440                         }
1441
1442                         /*
1443                          * Use of some Hop-by-Hop options or some
1444                          * Destination options, might require special
1445                          * privilege.  That is, normal applications
1446                          * (without special privilege) might be forbidden
1447                          * from setting certain options in outgoing packets,
1448                          * and might never see certain options in received
1449                          * packets. [RFC 2292 Section 6]
1450                          * KAME specific note:
1451                          *  KAME prevents non-privileged users from sending or
1452                          *  receiving ANY hbh/dst options in order to avoid
1453                          *  overhead of parsing options in the kernel.
1454                          */
1455                         case IPV6_RECVHOPOPTS:
1456                         case IPV6_RECVDSTOPTS:
1457                         case IPV6_RECVRTHDRDSTOPTS:
1458                                 if (td != NULL) {
1459                                         error = priv_check(td,
1460                                             PRIV_NETINET_SETHDROPTS);
1461                                         if (error)
1462                                                 break;
1463                                 }
1464                                 /* FALLTHROUGH */
1465                         case IPV6_UNICAST_HOPS:
1466                         case IPV6_HOPLIMIT:
1467
1468                         case IPV6_RECVPKTINFO:
1469                         case IPV6_RECVHOPLIMIT:
1470                         case IPV6_RECVRTHDR:
1471                         case IPV6_RECVPATHMTU:
1472                         case IPV6_RECVTCLASS:
1473                         case IPV6_RECVFLOWID:
1474 #ifdef  RSS
1475                         case IPV6_RECVRSSBUCKETID:
1476 #endif
1477                         case IPV6_V6ONLY:
1478                         case IPV6_AUTOFLOWLABEL:
1479                         case IPV6_BINDANY:
1480                         case IPV6_BINDMULTI:
1481 #ifdef  RSS
1482                         case IPV6_RSS_LISTEN_BUCKET:
1483 #endif
1484                                 if (optname == IPV6_BINDANY && td != NULL) {
1485                                         error = priv_check(td,
1486                                             PRIV_NETINET_BINDANY);
1487                                         if (error)
1488                                                 break;
1489                                 }
1490
1491                                 if (optlen != sizeof(int)) {
1492                                         error = EINVAL;
1493                                         break;
1494                                 }
1495                                 error = sooptcopyin(sopt, &optval,
1496                                         sizeof optval, sizeof optval);
1497                                 if (error)
1498                                         break;
1499                                 switch (optname) {
1500
1501                                 case IPV6_UNICAST_HOPS:
1502                                         if (optval < -1 || optval >= 256)
1503                                                 error = EINVAL;
1504                                         else {
1505                                                 /* -1 = kernel default */
1506                                                 in6p->in6p_hops = optval;
1507                                                 if ((in6p->inp_vflag &
1508                                                      INP_IPV4) != 0)
1509                                                         in6p->inp_ip_ttl = optval;
1510                                         }
1511                                         break;
1512 #define OPTSET(bit) \
1513 do { \
1514         INP_WLOCK(in6p); \
1515         if (optval) \
1516                 in6p->inp_flags |= (bit); \
1517         else \
1518                 in6p->inp_flags &= ~(bit); \
1519         INP_WUNLOCK(in6p); \
1520 } while (/*CONSTCOND*/ 0)
1521 #define OPTSET2292(bit) \
1522 do { \
1523         INP_WLOCK(in6p); \
1524         in6p->inp_flags |= IN6P_RFC2292; \
1525         if (optval) \
1526                 in6p->inp_flags |= (bit); \
1527         else \
1528                 in6p->inp_flags &= ~(bit); \
1529         INP_WUNLOCK(in6p); \
1530 } while (/*CONSTCOND*/ 0)
1531 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1532
1533 #define OPTSET2(bit, val) do {                                          \
1534         INP_WLOCK(in6p);                                                \
1535         if (val)                                                        \
1536                 in6p->inp_flags2 |= bit;                                \
1537         else                                                            \
1538                 in6p->inp_flags2 &= ~bit;                               \
1539         INP_WUNLOCK(in6p);                                              \
1540 } while (0)
1541 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1542
1543                                 case IPV6_RECVPKTINFO:
1544                                         /* cannot mix with RFC2292 */
1545                                         if (OPTBIT(IN6P_RFC2292)) {
1546                                                 error = EINVAL;
1547                                                 break;
1548                                         }
1549                                         OPTSET(IN6P_PKTINFO);
1550                                         break;
1551
1552                                 case IPV6_HOPLIMIT:
1553                                 {
1554                                         struct ip6_pktopts **optp;
1555
1556                                         /* cannot mix with RFC2292 */
1557                                         if (OPTBIT(IN6P_RFC2292)) {
1558                                                 error = EINVAL;
1559                                                 break;
1560                                         }
1561                                         optp = &in6p->in6p_outputopts;
1562                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1563                                             (u_char *)&optval, sizeof(optval),
1564                                             optp, (td != NULL) ? td->td_ucred :
1565                                             NULL, uproto);
1566                                         break;
1567                                 }
1568
1569                                 case IPV6_RECVHOPLIMIT:
1570                                         /* cannot mix with RFC2292 */
1571                                         if (OPTBIT(IN6P_RFC2292)) {
1572                                                 error = EINVAL;
1573                                                 break;
1574                                         }
1575                                         OPTSET(IN6P_HOPLIMIT);
1576                                         break;
1577
1578                                 case IPV6_RECVHOPOPTS:
1579                                         /* cannot mix with RFC2292 */
1580                                         if (OPTBIT(IN6P_RFC2292)) {
1581                                                 error = EINVAL;
1582                                                 break;
1583                                         }
1584                                         OPTSET(IN6P_HOPOPTS);
1585                                         break;
1586
1587                                 case IPV6_RECVDSTOPTS:
1588                                         /* cannot mix with RFC2292 */
1589                                         if (OPTBIT(IN6P_RFC2292)) {
1590                                                 error = EINVAL;
1591                                                 break;
1592                                         }
1593                                         OPTSET(IN6P_DSTOPTS);
1594                                         break;
1595
1596                                 case IPV6_RECVRTHDRDSTOPTS:
1597                                         /* cannot mix with RFC2292 */
1598                                         if (OPTBIT(IN6P_RFC2292)) {
1599                                                 error = EINVAL;
1600                                                 break;
1601                                         }
1602                                         OPTSET(IN6P_RTHDRDSTOPTS);
1603                                         break;
1604
1605                                 case IPV6_RECVRTHDR:
1606                                         /* cannot mix with RFC2292 */
1607                                         if (OPTBIT(IN6P_RFC2292)) {
1608                                                 error = EINVAL;
1609                                                 break;
1610                                         }
1611                                         OPTSET(IN6P_RTHDR);
1612                                         break;
1613
1614                                 case IPV6_RECVPATHMTU:
1615                                         /*
1616                                          * We ignore this option for TCP
1617                                          * sockets.
1618                                          * (RFC3542 leaves this case
1619                                          * unspecified.)
1620                                          */
1621                                         if (uproto != IPPROTO_TCP)
1622                                                 OPTSET(IN6P_MTU);
1623                                         break;
1624
1625                                 case IPV6_RECVFLOWID:
1626                                         OPTSET2(INP_RECVFLOWID, optval);
1627                                         break;
1628
1629 #ifdef  RSS
1630                                 case IPV6_RECVRSSBUCKETID:
1631                                         OPTSET2(INP_RECVRSSBUCKETID, optval);
1632                                         break;
1633 #endif
1634
1635                                 case IPV6_V6ONLY:
1636                                         /*
1637                                          * make setsockopt(IPV6_V6ONLY)
1638                                          * available only prior to bind(2).
1639                                          * see ipng mailing list, Jun 22 2001.
1640                                          */
1641                                         if (in6p->inp_lport ||
1642                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1643                                                 error = EINVAL;
1644                                                 break;
1645                                         }
1646                                         OPTSET(IN6P_IPV6_V6ONLY);
1647                                         if (optval)
1648                                                 in6p->inp_vflag &= ~INP_IPV4;
1649                                         else
1650                                                 in6p->inp_vflag |= INP_IPV4;
1651                                         break;
1652                                 case IPV6_RECVTCLASS:
1653                                         /* cannot mix with RFC2292 XXX */
1654                                         if (OPTBIT(IN6P_RFC2292)) {
1655                                                 error = EINVAL;
1656                                                 break;
1657                                         }
1658                                         OPTSET(IN6P_TCLASS);
1659                                         break;
1660                                 case IPV6_AUTOFLOWLABEL:
1661                                         OPTSET(IN6P_AUTOFLOWLABEL);
1662                                         break;
1663
1664                                 case IPV6_BINDANY:
1665                                         OPTSET(INP_BINDANY);
1666                                         break;
1667
1668                                 case IPV6_BINDMULTI:
1669                                         OPTSET2(INP_BINDMULTI, optval);
1670                                         break;
1671 #ifdef  RSS
1672                                 case IPV6_RSS_LISTEN_BUCKET:
1673                                         if ((optval >= 0) &&
1674                                             (optval < rss_getnumbuckets())) {
1675                                                 in6p->inp_rss_listen_bucket = optval;
1676                                                 OPTSET2(INP_RSS_BUCKET_SET, 1);
1677                                         } else {
1678                                                 error = EINVAL;
1679                                         }
1680                                         break;
1681 #endif
1682                                 }
1683                                 break;
1684
1685                         case IPV6_TCLASS:
1686                         case IPV6_DONTFRAG:
1687                         case IPV6_USE_MIN_MTU:
1688                         case IPV6_PREFER_TEMPADDR:
1689                                 if (optlen != sizeof(optval)) {
1690                                         error = EINVAL;
1691                                         break;
1692                                 }
1693                                 error = sooptcopyin(sopt, &optval,
1694                                         sizeof optval, sizeof optval);
1695                                 if (error)
1696                                         break;
1697                                 {
1698                                         struct ip6_pktopts **optp;
1699                                         optp = &in6p->in6p_outputopts;
1700                                         error = ip6_pcbopt(optname,
1701                                             (u_char *)&optval, sizeof(optval),
1702                                             optp, (td != NULL) ? td->td_ucred :
1703                                             NULL, uproto);
1704                                         break;
1705                                 }
1706
1707                         case IPV6_2292PKTINFO:
1708                         case IPV6_2292HOPLIMIT:
1709                         case IPV6_2292HOPOPTS:
1710                         case IPV6_2292DSTOPTS:
1711                         case IPV6_2292RTHDR:
1712                                 /* RFC 2292 */
1713                                 if (optlen != sizeof(int)) {
1714                                         error = EINVAL;
1715                                         break;
1716                                 }
1717                                 error = sooptcopyin(sopt, &optval,
1718                                         sizeof optval, sizeof optval);
1719                                 if (error)
1720                                         break;
1721                                 switch (optname) {
1722                                 case IPV6_2292PKTINFO:
1723                                         OPTSET2292(IN6P_PKTINFO);
1724                                         break;
1725                                 case IPV6_2292HOPLIMIT:
1726                                         OPTSET2292(IN6P_HOPLIMIT);
1727                                         break;
1728                                 case IPV6_2292HOPOPTS:
1729                                         /*
1730                                          * Check super-user privilege.
1731                                          * See comments for IPV6_RECVHOPOPTS.
1732                                          */
1733                                         if (td != NULL) {
1734                                                 error = priv_check(td,
1735                                                     PRIV_NETINET_SETHDROPTS);
1736                                                 if (error)
1737                                                         return (error);
1738                                         }
1739                                         OPTSET2292(IN6P_HOPOPTS);
1740                                         break;
1741                                 case IPV6_2292DSTOPTS:
1742                                         if (td != NULL) {
1743                                                 error = priv_check(td,
1744                                                     PRIV_NETINET_SETHDROPTS);
1745                                                 if (error)
1746                                                         return (error);
1747                                         }
1748                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1749                                         break;
1750                                 case IPV6_2292RTHDR:
1751                                         OPTSET2292(IN6P_RTHDR);
1752                                         break;
1753                                 }
1754                                 break;
1755                         case IPV6_PKTINFO:
1756                         case IPV6_HOPOPTS:
1757                         case IPV6_RTHDR:
1758                         case IPV6_DSTOPTS:
1759                         case IPV6_RTHDRDSTOPTS:
1760                         case IPV6_NEXTHOP:
1761                         {
1762                                 /* new advanced API (RFC3542) */
1763                                 u_char *optbuf;
1764                                 u_char optbuf_storage[MCLBYTES];
1765                                 int optlen;
1766                                 struct ip6_pktopts **optp;
1767
1768                                 /* cannot mix with RFC2292 */
1769                                 if (OPTBIT(IN6P_RFC2292)) {
1770                                         error = EINVAL;
1771                                         break;
1772                                 }
1773
1774                                 /*
1775                                  * We only ensure valsize is not too large
1776                                  * here.  Further validation will be done
1777                                  * later.
1778                                  */
1779                                 error = sooptcopyin(sopt, optbuf_storage,
1780                                     sizeof(optbuf_storage), 0);
1781                                 if (error)
1782                                         break;
1783                                 optlen = sopt->sopt_valsize;
1784                                 optbuf = optbuf_storage;
1785                                 optp = &in6p->in6p_outputopts;
1786                                 error = ip6_pcbopt(optname, optbuf, optlen,
1787                                     optp, (td != NULL) ? td->td_ucred : NULL,
1788                                     uproto);
1789                                 break;
1790                         }
1791 #undef OPTSET
1792
1793                         case IPV6_MULTICAST_IF:
1794                         case IPV6_MULTICAST_HOPS:
1795                         case IPV6_MULTICAST_LOOP:
1796                         case IPV6_JOIN_GROUP:
1797                         case IPV6_LEAVE_GROUP:
1798                         case IPV6_MSFILTER:
1799                         case MCAST_BLOCK_SOURCE:
1800                         case MCAST_UNBLOCK_SOURCE:
1801                         case MCAST_JOIN_GROUP:
1802                         case MCAST_LEAVE_GROUP:
1803                         case MCAST_JOIN_SOURCE_GROUP:
1804                         case MCAST_LEAVE_SOURCE_GROUP:
1805                                 error = ip6_setmoptions(in6p, sopt);
1806                                 break;
1807
1808                         case IPV6_PORTRANGE:
1809                                 error = sooptcopyin(sopt, &optval,
1810                                     sizeof optval, sizeof optval);
1811                                 if (error)
1812                                         break;
1813
1814                                 INP_WLOCK(in6p);
1815                                 switch (optval) {
1816                                 case IPV6_PORTRANGE_DEFAULT:
1817                                         in6p->inp_flags &= ~(INP_LOWPORT);
1818                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1819                                         break;
1820
1821                                 case IPV6_PORTRANGE_HIGH:
1822                                         in6p->inp_flags &= ~(INP_LOWPORT);
1823                                         in6p->inp_flags |= INP_HIGHPORT;
1824                                         break;
1825
1826                                 case IPV6_PORTRANGE_LOW:
1827                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1828                                         in6p->inp_flags |= INP_LOWPORT;
1829                                         break;
1830
1831                                 default:
1832                                         error = EINVAL;
1833                                         break;
1834                                 }
1835                                 INP_WUNLOCK(in6p);
1836                                 break;
1837
1838 #ifdef IPSEC
1839                         case IPV6_IPSEC_POLICY:
1840                         {
1841                                 caddr_t req;
1842                                 struct mbuf *m;
1843
1844                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1845                                         break;
1846                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1847                                         break;
1848                                 req = mtod(m, caddr_t);
1849                                 error = ipsec_set_policy(in6p, optname, req,
1850                                     m->m_len, (sopt->sopt_td != NULL) ?
1851                                     sopt->sopt_td->td_ucred : NULL);
1852                                 m_freem(m);
1853                                 break;
1854                         }
1855 #endif /* IPSEC */
1856
1857                         default:
1858                                 error = ENOPROTOOPT;
1859                                 break;
1860                         }
1861                         break;
1862
1863                 case SOPT_GET:
1864                         switch (optname) {
1865
1866                         case IPV6_2292PKTOPTIONS:
1867 #ifdef IPV6_PKTOPTIONS
1868                         case IPV6_PKTOPTIONS:
1869 #endif
1870                                 /*
1871                                  * RFC3542 (effectively) deprecated the
1872                                  * semantics of the 2292-style pktoptions.
1873                                  * Since it was not reliable in nature (i.e.,
1874                                  * applications had to expect the lack of some
1875                                  * information after all), it would make sense
1876                                  * to simplify this part by always returning
1877                                  * empty data.
1878                                  */
1879                                 sopt->sopt_valsize = 0;
1880                                 break;
1881
1882                         case IPV6_RECVHOPOPTS:
1883                         case IPV6_RECVDSTOPTS:
1884                         case IPV6_RECVRTHDRDSTOPTS:
1885                         case IPV6_UNICAST_HOPS:
1886                         case IPV6_RECVPKTINFO:
1887                         case IPV6_RECVHOPLIMIT:
1888                         case IPV6_RECVRTHDR:
1889                         case IPV6_RECVPATHMTU:
1890
1891                         case IPV6_V6ONLY:
1892                         case IPV6_PORTRANGE:
1893                         case IPV6_RECVTCLASS:
1894                         case IPV6_AUTOFLOWLABEL:
1895                         case IPV6_BINDANY:
1896                         case IPV6_FLOWID:
1897                         case IPV6_FLOWTYPE:
1898                         case IPV6_RECVFLOWID:
1899 #ifdef  RSS
1900                         case IPV6_RSSBUCKETID:
1901                         case IPV6_RECVRSSBUCKETID:
1902 #endif
1903                         case IPV6_BINDMULTI:
1904                                 switch (optname) {
1905
1906                                 case IPV6_RECVHOPOPTS:
1907                                         optval = OPTBIT(IN6P_HOPOPTS);
1908                                         break;
1909
1910                                 case IPV6_RECVDSTOPTS:
1911                                         optval = OPTBIT(IN6P_DSTOPTS);
1912                                         break;
1913
1914                                 case IPV6_RECVRTHDRDSTOPTS:
1915                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1916                                         break;
1917
1918                                 case IPV6_UNICAST_HOPS:
1919                                         optval = in6p->in6p_hops;
1920                                         break;
1921
1922                                 case IPV6_RECVPKTINFO:
1923                                         optval = OPTBIT(IN6P_PKTINFO);
1924                                         break;
1925
1926                                 case IPV6_RECVHOPLIMIT:
1927                                         optval = OPTBIT(IN6P_HOPLIMIT);
1928                                         break;
1929
1930                                 case IPV6_RECVRTHDR:
1931                                         optval = OPTBIT(IN6P_RTHDR);
1932                                         break;
1933
1934                                 case IPV6_RECVPATHMTU:
1935                                         optval = OPTBIT(IN6P_MTU);
1936                                         break;
1937
1938                                 case IPV6_V6ONLY:
1939                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1940                                         break;
1941
1942                                 case IPV6_PORTRANGE:
1943                                     {
1944                                         int flags;
1945                                         flags = in6p->inp_flags;
1946                                         if (flags & INP_HIGHPORT)
1947                                                 optval = IPV6_PORTRANGE_HIGH;
1948                                         else if (flags & INP_LOWPORT)
1949                                                 optval = IPV6_PORTRANGE_LOW;
1950                                         else
1951                                                 optval = 0;
1952                                         break;
1953                                     }
1954                                 case IPV6_RECVTCLASS:
1955                                         optval = OPTBIT(IN6P_TCLASS);
1956                                         break;
1957
1958                                 case IPV6_AUTOFLOWLABEL:
1959                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1960                                         break;
1961
1962                                 case IPV6_BINDANY:
1963                                         optval = OPTBIT(INP_BINDANY);
1964                                         break;
1965
1966                                 case IPV6_FLOWID:
1967                                         optval = in6p->inp_flowid;
1968                                         break;
1969
1970                                 case IPV6_FLOWTYPE:
1971                                         optval = in6p->inp_flowtype;
1972                                         break;
1973
1974                                 case IPV6_RECVFLOWID:
1975                                         optval = OPTBIT2(INP_RECVFLOWID);
1976                                         break;
1977 #ifdef  RSS
1978                                 case IPV6_RSSBUCKETID:
1979                                         retval =
1980                                             rss_hash2bucket(in6p->inp_flowid,
1981                                             in6p->inp_flowtype,
1982                                             &rss_bucket);
1983                                         if (retval == 0)
1984                                                 optval = rss_bucket;
1985                                         else
1986                                                 error = EINVAL;
1987                                         break;
1988
1989                                 case IPV6_RECVRSSBUCKETID:
1990                                         optval = OPTBIT2(INP_RECVRSSBUCKETID);
1991                                         break;
1992 #endif
1993
1994                                 case IPV6_BINDMULTI:
1995                                         optval = OPTBIT2(INP_BINDMULTI);
1996                                         break;
1997
1998                                 }
1999                                 if (error)
2000                                         break;
2001                                 error = sooptcopyout(sopt, &optval,
2002                                         sizeof optval);
2003                                 break;
2004
2005                         case IPV6_PATHMTU:
2006                         {
2007                                 u_long pmtu = 0;
2008                                 struct ip6_mtuinfo mtuinfo;
2009
2010                                 if (!(so->so_state & SS_ISCONNECTED))
2011                                         return (ENOTCONN);
2012                                 /*
2013                                  * XXX: we dot not consider the case of source
2014                                  * routing, or optional information to specify
2015                                  * the outgoing interface.
2016                                  */
2017                                 error = ip6_getpmtu_ctl(so->so_fibnum,
2018                                     &in6p->in6p_faddr, &pmtu);
2019                                 if (error)
2020                                         break;
2021                                 if (pmtu > IPV6_MAXPACKET)
2022                                         pmtu = IPV6_MAXPACKET;
2023
2024                                 bzero(&mtuinfo, sizeof(mtuinfo));
2025                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2026                                 optdata = (void *)&mtuinfo;
2027                                 optdatalen = sizeof(mtuinfo);
2028                                 error = sooptcopyout(sopt, optdata,
2029                                     optdatalen);
2030                                 break;
2031                         }
2032
2033                         case IPV6_2292PKTINFO:
2034                         case IPV6_2292HOPLIMIT:
2035                         case IPV6_2292HOPOPTS:
2036                         case IPV6_2292RTHDR:
2037                         case IPV6_2292DSTOPTS:
2038                                 switch (optname) {
2039                                 case IPV6_2292PKTINFO:
2040                                         optval = OPTBIT(IN6P_PKTINFO);
2041                                         break;
2042                                 case IPV6_2292HOPLIMIT:
2043                                         optval = OPTBIT(IN6P_HOPLIMIT);
2044                                         break;
2045                                 case IPV6_2292HOPOPTS:
2046                                         optval = OPTBIT(IN6P_HOPOPTS);
2047                                         break;
2048                                 case IPV6_2292RTHDR:
2049                                         optval = OPTBIT(IN6P_RTHDR);
2050                                         break;
2051                                 case IPV6_2292DSTOPTS:
2052                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2053                                         break;
2054                                 }
2055                                 error = sooptcopyout(sopt, &optval,
2056                                     sizeof optval);
2057                                 break;
2058                         case IPV6_PKTINFO:
2059                         case IPV6_HOPOPTS:
2060                         case IPV6_RTHDR:
2061                         case IPV6_DSTOPTS:
2062                         case IPV6_RTHDRDSTOPTS:
2063                         case IPV6_NEXTHOP:
2064                         case IPV6_TCLASS:
2065                         case IPV6_DONTFRAG:
2066                         case IPV6_USE_MIN_MTU:
2067                         case IPV6_PREFER_TEMPADDR:
2068                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
2069                                     optname, sopt);
2070                                 break;
2071
2072                         case IPV6_MULTICAST_IF:
2073                         case IPV6_MULTICAST_HOPS:
2074                         case IPV6_MULTICAST_LOOP:
2075                         case IPV6_MSFILTER:
2076                                 error = ip6_getmoptions(in6p, sopt);
2077                                 break;
2078
2079 #ifdef IPSEC
2080                         case IPV6_IPSEC_POLICY:
2081                           {
2082                                 caddr_t req = NULL;
2083                                 size_t len = 0;
2084                                 struct mbuf *m = NULL;
2085                                 struct mbuf **mp = &m;
2086                                 size_t ovalsize = sopt->sopt_valsize;
2087                                 caddr_t oval = (caddr_t)sopt->sopt_val;
2088
2089                                 error = soopt_getm(sopt, &m); /* XXX */
2090                                 if (error != 0)
2091                                         break;
2092                                 error = soopt_mcopyin(sopt, m); /* XXX */
2093                                 if (error != 0)
2094                                         break;
2095                                 sopt->sopt_valsize = ovalsize;
2096                                 sopt->sopt_val = oval;
2097                                 if (m) {
2098                                         req = mtod(m, caddr_t);
2099                                         len = m->m_len;
2100                                 }
2101                                 error = ipsec_get_policy(in6p, req, len, mp);
2102                                 if (error == 0)
2103                                         error = soopt_mcopyout(sopt, m); /* XXX */
2104                                 if (error == 0 && m)
2105                                         m_freem(m);
2106                                 break;
2107                           }
2108 #endif /* IPSEC */
2109
2110                         default:
2111                                 error = ENOPROTOOPT;
2112                                 break;
2113                         }
2114                         break;
2115                 }
2116         }
2117         return (error);
2118 }
2119
2120 int
2121 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2122 {
2123         int error = 0, optval, optlen;
2124         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2125         struct inpcb *in6p = sotoinpcb(so);
2126         int level, op, optname;
2127
2128         level = sopt->sopt_level;
2129         op = sopt->sopt_dir;
2130         optname = sopt->sopt_name;
2131         optlen = sopt->sopt_valsize;
2132
2133         if (level != IPPROTO_IPV6) {
2134                 return (EINVAL);
2135         }
2136
2137         switch (optname) {
2138         case IPV6_CHECKSUM:
2139                 /*
2140                  * For ICMPv6 sockets, no modification allowed for checksum
2141                  * offset, permit "no change" values to help existing apps.
2142                  *
2143                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2144                  * for an ICMPv6 socket will fail."
2145                  * The current behavior does not meet RFC3542.
2146                  */
2147                 switch (op) {
2148                 case SOPT_SET:
2149                         if (optlen != sizeof(int)) {
2150                                 error = EINVAL;
2151                                 break;
2152                         }
2153                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2154                                             sizeof(optval));
2155                         if (error)
2156                                 break;
2157                         if ((optval % 2) != 0) {
2158                                 /* the API assumes even offset values */
2159                                 error = EINVAL;
2160                         } else if (so->so_proto->pr_protocol ==
2161                             IPPROTO_ICMPV6) {
2162                                 if (optval != icmp6off)
2163                                         error = EINVAL;
2164                         } else
2165                                 in6p->in6p_cksum = optval;
2166                         break;
2167
2168                 case SOPT_GET:
2169                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2170                                 optval = icmp6off;
2171                         else
2172                                 optval = in6p->in6p_cksum;
2173
2174                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2175                         break;
2176
2177                 default:
2178                         error = EINVAL;
2179                         break;
2180                 }
2181                 break;
2182
2183         default:
2184                 error = ENOPROTOOPT;
2185                 break;
2186         }
2187
2188         return (error);
2189 }
2190
2191 /*
2192  * Set up IP6 options in pcb for insertion in output packets or
2193  * specifying behavior of outgoing packets.
2194  */
2195 static int
2196 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2197     struct socket *so, struct sockopt *sopt)
2198 {
2199         struct ip6_pktopts *opt = *pktopt;
2200         int error = 0;
2201         struct thread *td = sopt->sopt_td;
2202
2203         /* turn off any old options. */
2204         if (opt) {
2205 #ifdef DIAGNOSTIC
2206                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2207                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2208                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2209                         printf("ip6_pcbopts: all specified options are cleared.\n");
2210 #endif
2211                 ip6_clearpktopts(opt, -1);
2212         } else
2213                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2214         *pktopt = NULL;
2215
2216         if (!m || m->m_len == 0) {
2217                 /*
2218                  * Only turning off any previous options, regardless of
2219                  * whether the opt is just created or given.
2220                  */
2221                 free(opt, M_IP6OPT);
2222                 return (0);
2223         }
2224
2225         /*  set options specified by user. */
2226         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2227             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2228                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2229                 free(opt, M_IP6OPT);
2230                 return (error);
2231         }
2232         *pktopt = opt;
2233         return (0);
2234 }
2235
2236 /*
2237  * initialize ip6_pktopts.  beware that there are non-zero default values in
2238  * the struct.
2239  */
2240 void
2241 ip6_initpktopts(struct ip6_pktopts *opt)
2242 {
2243
2244         bzero(opt, sizeof(*opt));
2245         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2246         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2247         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2248         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2249 }
2250
2251 static int
2252 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2253     struct ucred *cred, int uproto)
2254 {
2255         struct ip6_pktopts *opt;
2256
2257         if (*pktopt == NULL) {
2258                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2259                     M_WAITOK);
2260                 ip6_initpktopts(*pktopt);
2261         }
2262         opt = *pktopt;
2263
2264         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2265 }
2266
2267 static int
2268 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2269 {
2270         void *optdata = NULL;
2271         int optdatalen = 0;
2272         struct ip6_ext *ip6e;
2273         int error = 0;
2274         struct in6_pktinfo null_pktinfo;
2275         int deftclass = 0, on;
2276         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2277         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2278
2279         switch (optname) {
2280         case IPV6_PKTINFO:
2281                 optdata = (void *)&null_pktinfo;
2282                 if (pktopt && pktopt->ip6po_pktinfo) {
2283                         bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2284                             sizeof(null_pktinfo));
2285                         in6_clearscope(&null_pktinfo.ipi6_addr);
2286                 } else {
2287                         /* XXX: we don't have to do this every time... */
2288                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2289                 }
2290                 optdatalen = sizeof(struct in6_pktinfo);
2291                 break;
2292         case IPV6_TCLASS:
2293                 if (pktopt && pktopt->ip6po_tclass >= 0)
2294                         optdata = (void *)&pktopt->ip6po_tclass;
2295                 else
2296                         optdata = (void *)&deftclass;
2297                 optdatalen = sizeof(int);
2298                 break;
2299         case IPV6_HOPOPTS:
2300                 if (pktopt && pktopt->ip6po_hbh) {
2301                         optdata = (void *)pktopt->ip6po_hbh;
2302                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2303                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2304                 }
2305                 break;
2306         case IPV6_RTHDR:
2307                 if (pktopt && pktopt->ip6po_rthdr) {
2308                         optdata = (void *)pktopt->ip6po_rthdr;
2309                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2310                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2311                 }
2312                 break;
2313         case IPV6_RTHDRDSTOPTS:
2314                 if (pktopt && pktopt->ip6po_dest1) {
2315                         optdata = (void *)pktopt->ip6po_dest1;
2316                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2317                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2318                 }
2319                 break;
2320         case IPV6_DSTOPTS:
2321                 if (pktopt && pktopt->ip6po_dest2) {
2322                         optdata = (void *)pktopt->ip6po_dest2;
2323                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2324                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2325                 }
2326                 break;
2327         case IPV6_NEXTHOP:
2328                 if (pktopt && pktopt->ip6po_nexthop) {
2329                         optdata = (void *)pktopt->ip6po_nexthop;
2330                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2331                 }
2332                 break;
2333         case IPV6_USE_MIN_MTU:
2334                 if (pktopt)
2335                         optdata = (void *)&pktopt->ip6po_minmtu;
2336                 else
2337                         optdata = (void *)&defminmtu;
2338                 optdatalen = sizeof(int);
2339                 break;
2340         case IPV6_DONTFRAG:
2341                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2342                         on = 1;
2343                 else
2344                         on = 0;
2345                 optdata = (void *)&on;
2346                 optdatalen = sizeof(on);
2347                 break;
2348         case IPV6_PREFER_TEMPADDR:
2349                 if (pktopt)
2350                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2351                 else
2352                         optdata = (void *)&defpreftemp;
2353                 optdatalen = sizeof(int);
2354                 break;
2355         default:                /* should not happen */
2356 #ifdef DIAGNOSTIC
2357                 panic("ip6_getpcbopt: unexpected option\n");
2358 #endif
2359                 return (ENOPROTOOPT);
2360         }
2361
2362         error = sooptcopyout(sopt, optdata, optdatalen);
2363
2364         return (error);
2365 }
2366
2367 void
2368 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2369 {
2370         if (pktopt == NULL)
2371                 return;
2372
2373         if (optname == -1 || optname == IPV6_PKTINFO) {
2374                 if (pktopt->ip6po_pktinfo)
2375                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2376                 pktopt->ip6po_pktinfo = NULL;
2377         }
2378         if (optname == -1 || optname == IPV6_HOPLIMIT)
2379                 pktopt->ip6po_hlim = -1;
2380         if (optname == -1 || optname == IPV6_TCLASS)
2381                 pktopt->ip6po_tclass = -1;
2382         if (optname == -1 || optname == IPV6_NEXTHOP) {
2383                 if (pktopt->ip6po_nextroute.ro_rt) {
2384                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2385                         pktopt->ip6po_nextroute.ro_rt = NULL;
2386                 }
2387                 if (pktopt->ip6po_nexthop)
2388                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2389                 pktopt->ip6po_nexthop = NULL;
2390         }
2391         if (optname == -1 || optname == IPV6_HOPOPTS) {
2392                 if (pktopt->ip6po_hbh)
2393                         free(pktopt->ip6po_hbh, M_IP6OPT);
2394                 pktopt->ip6po_hbh = NULL;
2395         }
2396         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2397                 if (pktopt->ip6po_dest1)
2398                         free(pktopt->ip6po_dest1, M_IP6OPT);
2399                 pktopt->ip6po_dest1 = NULL;
2400         }
2401         if (optname == -1 || optname == IPV6_RTHDR) {
2402                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2403                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2404                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2405                 if (pktopt->ip6po_route.ro_rt) {
2406                         RTFREE(pktopt->ip6po_route.ro_rt);
2407                         pktopt->ip6po_route.ro_rt = NULL;
2408                 }
2409         }
2410         if (optname == -1 || optname == IPV6_DSTOPTS) {
2411                 if (pktopt->ip6po_dest2)
2412                         free(pktopt->ip6po_dest2, M_IP6OPT);
2413                 pktopt->ip6po_dest2 = NULL;
2414         }
2415 }
2416
2417 #define PKTOPT_EXTHDRCPY(type) \
2418 do {\
2419         if (src->type) {\
2420                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2421                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2422                 if (dst->type == NULL && canwait == M_NOWAIT)\
2423                         goto bad;\
2424                 bcopy(src->type, dst->type, hlen);\
2425         }\
2426 } while (/*CONSTCOND*/ 0)
2427
2428 static int
2429 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2430 {
2431         if (dst == NULL || src == NULL)  {
2432                 printf("ip6_clearpktopts: invalid argument\n");
2433                 return (EINVAL);
2434         }
2435
2436         dst->ip6po_hlim = src->ip6po_hlim;
2437         dst->ip6po_tclass = src->ip6po_tclass;
2438         dst->ip6po_flags = src->ip6po_flags;
2439         dst->ip6po_minmtu = src->ip6po_minmtu;
2440         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2441         if (src->ip6po_pktinfo) {
2442                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2443                     M_IP6OPT, canwait);
2444                 if (dst->ip6po_pktinfo == NULL)
2445                         goto bad;
2446                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2447         }
2448         if (src->ip6po_nexthop) {
2449                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2450                     M_IP6OPT, canwait);
2451                 if (dst->ip6po_nexthop == NULL)
2452                         goto bad;
2453                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2454                     src->ip6po_nexthop->sa_len);
2455         }
2456         PKTOPT_EXTHDRCPY(ip6po_hbh);
2457         PKTOPT_EXTHDRCPY(ip6po_dest1);
2458         PKTOPT_EXTHDRCPY(ip6po_dest2);
2459         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2460         return (0);
2461
2462   bad:
2463         ip6_clearpktopts(dst, -1);
2464         return (ENOBUFS);
2465 }
2466 #undef PKTOPT_EXTHDRCPY
2467
2468 struct ip6_pktopts *
2469 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2470 {
2471         int error;
2472         struct ip6_pktopts *dst;
2473
2474         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2475         if (dst == NULL)
2476                 return (NULL);
2477         ip6_initpktopts(dst);
2478
2479         if ((error = copypktopts(dst, src, canwait)) != 0) {
2480                 free(dst, M_IP6OPT);
2481                 return (NULL);
2482         }
2483
2484         return (dst);
2485 }
2486
2487 void
2488 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2489 {
2490         if (pktopt == NULL)
2491                 return;
2492
2493         ip6_clearpktopts(pktopt, -1);
2494
2495         free(pktopt, M_IP6OPT);
2496 }
2497
2498 /*
2499  * Set IPv6 outgoing packet options based on advanced API.
2500  */
2501 int
2502 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2503     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2504 {
2505         struct cmsghdr *cm = 0;
2506
2507         if (control == NULL || opt == NULL)
2508                 return (EINVAL);
2509
2510         ip6_initpktopts(opt);
2511         if (stickyopt) {
2512                 int error;
2513
2514                 /*
2515                  * If stickyopt is provided, make a local copy of the options
2516                  * for this particular packet, then override them by ancillary
2517                  * objects.
2518                  * XXX: copypktopts() does not copy the cached route to a next
2519                  * hop (if any).  This is not very good in terms of efficiency,
2520                  * but we can allow this since this option should be rarely
2521                  * used.
2522                  */
2523                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2524                         return (error);
2525         }
2526
2527         /*
2528          * XXX: Currently, we assume all the optional information is stored
2529          * in a single mbuf.
2530          */
2531         if (control->m_next)
2532                 return (EINVAL);
2533
2534         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2535             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2536                 int error;
2537
2538                 if (control->m_len < CMSG_LEN(0))
2539                         return (EINVAL);
2540
2541                 cm = mtod(control, struct cmsghdr *);
2542                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2543                         return (EINVAL);
2544                 if (cm->cmsg_level != IPPROTO_IPV6)
2545                         continue;
2546
2547                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2548                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2549                 if (error)
2550                         return (error);
2551         }
2552
2553         return (0);
2554 }
2555
2556 /*
2557  * Set a particular packet option, as a sticky option or an ancillary data
2558  * item.  "len" can be 0 only when it's a sticky option.
2559  * We have 4 cases of combination of "sticky" and "cmsg":
2560  * "sticky=0, cmsg=0": impossible
2561  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2562  * "sticky=1, cmsg=0": RFC3542 socket option
2563  * "sticky=1, cmsg=1": RFC2292 socket option
2564  */
2565 static int
2566 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2567     struct ucred *cred, int sticky, int cmsg, int uproto)
2568 {
2569         int minmtupolicy, preftemp;
2570         int error;
2571
2572         if (!sticky && !cmsg) {
2573 #ifdef DIAGNOSTIC
2574                 printf("ip6_setpktopt: impossible case\n");
2575 #endif
2576                 return (EINVAL);
2577         }
2578
2579         /*
2580          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2581          * not be specified in the context of RFC3542.  Conversely,
2582          * RFC3542 types should not be specified in the context of RFC2292.
2583          */
2584         if (!cmsg) {
2585                 switch (optname) {
2586                 case IPV6_2292PKTINFO:
2587                 case IPV6_2292HOPLIMIT:
2588                 case IPV6_2292NEXTHOP:
2589                 case IPV6_2292HOPOPTS:
2590                 case IPV6_2292DSTOPTS:
2591                 case IPV6_2292RTHDR:
2592                 case IPV6_2292PKTOPTIONS:
2593                         return (ENOPROTOOPT);
2594                 }
2595         }
2596         if (sticky && cmsg) {
2597                 switch (optname) {
2598                 case IPV6_PKTINFO:
2599                 case IPV6_HOPLIMIT:
2600                 case IPV6_NEXTHOP:
2601                 case IPV6_HOPOPTS:
2602                 case IPV6_DSTOPTS:
2603                 case IPV6_RTHDRDSTOPTS:
2604                 case IPV6_RTHDR:
2605                 case IPV6_USE_MIN_MTU:
2606                 case IPV6_DONTFRAG:
2607                 case IPV6_TCLASS:
2608                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2609                         return (ENOPROTOOPT);
2610                 }
2611         }
2612
2613         switch (optname) {
2614         case IPV6_2292PKTINFO:
2615         case IPV6_PKTINFO:
2616         {
2617                 struct ifnet *ifp = NULL;
2618                 struct in6_pktinfo *pktinfo;
2619
2620                 if (len != sizeof(struct in6_pktinfo))
2621                         return (EINVAL);
2622
2623                 pktinfo = (struct in6_pktinfo *)buf;
2624
2625                 /*
2626                  * An application can clear any sticky IPV6_PKTINFO option by
2627                  * doing a "regular" setsockopt with ipi6_addr being
2628                  * in6addr_any and ipi6_ifindex being zero.
2629                  * [RFC 3542, Section 6]
2630                  */
2631                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2632                     pktinfo->ipi6_ifindex == 0 &&
2633                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2634                         ip6_clearpktopts(opt, optname);
2635                         break;
2636                 }
2637
2638                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2639                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2640                         return (EINVAL);
2641                 }
2642                 if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2643                         return (EINVAL);
2644                 /* validate the interface index if specified. */
2645                 if (pktinfo->ipi6_ifindex > V_if_index)
2646                          return (ENXIO);
2647                 if (pktinfo->ipi6_ifindex) {
2648                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2649                         if (ifp == NULL)
2650                                 return (ENXIO);
2651                 }
2652                 if (ifp != NULL && (
2653                     ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED))
2654                         return (ENETDOWN);
2655
2656                 if (ifp != NULL &&
2657                     !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2658                         struct in6_ifaddr *ia;
2659
2660                         in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2661                         ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2662                         if (ia == NULL)
2663                                 return (EADDRNOTAVAIL);
2664                         ifa_free(&ia->ia_ifa);
2665                 }
2666                 /*
2667                  * We store the address anyway, and let in6_selectsrc()
2668                  * validate the specified address.  This is because ipi6_addr
2669                  * may not have enough information about its scope zone, and
2670                  * we may need additional information (such as outgoing
2671                  * interface or the scope zone of a destination address) to
2672                  * disambiguate the scope.
2673                  * XXX: the delay of the validation may confuse the
2674                  * application when it is used as a sticky option.
2675                  */
2676                 if (opt->ip6po_pktinfo == NULL) {
2677                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2678                             M_IP6OPT, M_NOWAIT);
2679                         if (opt->ip6po_pktinfo == NULL)
2680                                 return (ENOBUFS);
2681                 }
2682                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2683                 break;
2684         }
2685
2686         case IPV6_2292HOPLIMIT:
2687         case IPV6_HOPLIMIT:
2688         {
2689                 int *hlimp;
2690
2691                 /*
2692                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2693                  * to simplify the ordering among hoplimit options.
2694                  */
2695                 if (optname == IPV6_HOPLIMIT && sticky)
2696                         return (ENOPROTOOPT);
2697
2698                 if (len != sizeof(int))
2699                         return (EINVAL);
2700                 hlimp = (int *)buf;
2701                 if (*hlimp < -1 || *hlimp > 255)
2702                         return (EINVAL);
2703
2704                 opt->ip6po_hlim = *hlimp;
2705                 break;
2706         }
2707
2708         case IPV6_TCLASS:
2709         {
2710                 int tclass;
2711
2712                 if (len != sizeof(int))
2713                         return (EINVAL);
2714                 tclass = *(int *)buf;
2715                 if (tclass < -1 || tclass > 255)
2716                         return (EINVAL);
2717
2718                 opt->ip6po_tclass = tclass;
2719                 break;
2720         }
2721
2722         case IPV6_2292NEXTHOP:
2723         case IPV6_NEXTHOP:
2724                 if (cred != NULL) {
2725                         error = priv_check_cred(cred,
2726                             PRIV_NETINET_SETHDROPTS, 0);
2727                         if (error)
2728                                 return (error);
2729                 }
2730
2731                 if (len == 0) { /* just remove the option */
2732                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2733                         break;
2734                 }
2735
2736                 /* check if cmsg_len is large enough for sa_len */
2737                 if (len < sizeof(struct sockaddr) || len < *buf)
2738                         return (EINVAL);
2739
2740                 switch (((struct sockaddr *)buf)->sa_family) {
2741                 case AF_INET6:
2742                 {
2743                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2744                         int error;
2745
2746                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2747                                 return (EINVAL);
2748
2749                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2750                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2751                                 return (EINVAL);
2752                         }
2753                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2754                             != 0) {
2755                                 return (error);
2756                         }
2757                         break;
2758                 }
2759                 case AF_LINK:   /* should eventually be supported */
2760                 default:
2761                         return (EAFNOSUPPORT);
2762                 }
2763
2764                 /* turn off the previous option, then set the new option. */
2765                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2766                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2767                 if (opt->ip6po_nexthop == NULL)
2768                         return (ENOBUFS);
2769                 bcopy(buf, opt->ip6po_nexthop, *buf);
2770                 break;
2771
2772         case IPV6_2292HOPOPTS:
2773         case IPV6_HOPOPTS:
2774         {
2775                 struct ip6_hbh *hbh;
2776                 int hbhlen;
2777
2778                 /*
2779                  * XXX: We don't allow a non-privileged user to set ANY HbH
2780                  * options, since per-option restriction has too much
2781                  * overhead.
2782                  */
2783                 if (cred != NULL) {
2784                         error = priv_check_cred(cred,
2785                             PRIV_NETINET_SETHDROPTS, 0);
2786                         if (error)
2787                                 return (error);
2788                 }
2789
2790                 if (len == 0) {
2791                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2792                         break;  /* just remove the option */
2793                 }
2794
2795                 /* message length validation */
2796                 if (len < sizeof(struct ip6_hbh))
2797                         return (EINVAL);
2798                 hbh = (struct ip6_hbh *)buf;
2799                 hbhlen = (hbh->ip6h_len + 1) << 3;
2800                 if (len != hbhlen)
2801                         return (EINVAL);
2802
2803                 /* turn off the previous option, then set the new option. */
2804                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2805                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2806                 if (opt->ip6po_hbh == NULL)
2807                         return (ENOBUFS);
2808                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2809
2810                 break;
2811         }
2812
2813         case IPV6_2292DSTOPTS:
2814         case IPV6_DSTOPTS:
2815         case IPV6_RTHDRDSTOPTS:
2816         {
2817                 struct ip6_dest *dest, **newdest = NULL;
2818                 int destlen;
2819
2820                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2821                         error = priv_check_cred(cred,
2822                             PRIV_NETINET_SETHDROPTS, 0);
2823                         if (error)
2824                                 return (error);
2825                 }
2826
2827                 if (len == 0) {
2828                         ip6_clearpktopts(opt, optname);
2829                         break;  /* just remove the option */
2830                 }
2831
2832                 /* message length validation */
2833                 if (len < sizeof(struct ip6_dest))
2834                         return (EINVAL);
2835                 dest = (struct ip6_dest *)buf;
2836                 destlen = (dest->ip6d_len + 1) << 3;
2837                 if (len != destlen)
2838                         return (EINVAL);
2839
2840                 /*
2841                  * Determine the position that the destination options header
2842                  * should be inserted; before or after the routing header.
2843                  */
2844                 switch (optname) {
2845                 case IPV6_2292DSTOPTS:
2846                         /*
2847                          * The old advacned API is ambiguous on this point.
2848                          * Our approach is to determine the position based
2849                          * according to the existence of a routing header.
2850                          * Note, however, that this depends on the order of the
2851                          * extension headers in the ancillary data; the 1st
2852                          * part of the destination options header must appear
2853                          * before the routing header in the ancillary data,
2854                          * too.
2855                          * RFC3542 solved the ambiguity by introducing
2856                          * separate ancillary data or option types.
2857                          */
2858                         if (opt->ip6po_rthdr == NULL)
2859                                 newdest = &opt->ip6po_dest1;
2860                         else
2861                                 newdest = &opt->ip6po_dest2;
2862                         break;
2863                 case IPV6_RTHDRDSTOPTS:
2864                         newdest = &opt->ip6po_dest1;
2865                         break;
2866                 case IPV6_DSTOPTS:
2867                         newdest = &opt->ip6po_dest2;
2868                         break;
2869                 }
2870
2871                 /* turn off the previous option, then set the new option. */
2872                 ip6_clearpktopts(opt, optname);
2873                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2874                 if (*newdest == NULL)
2875                         return (ENOBUFS);
2876                 bcopy(dest, *newdest, destlen);
2877
2878                 break;
2879         }
2880
2881         case IPV6_2292RTHDR:
2882         case IPV6_RTHDR:
2883         {
2884                 struct ip6_rthdr *rth;
2885                 int rthlen;
2886
2887                 if (len == 0) {
2888                         ip6_clearpktopts(opt, IPV6_RTHDR);
2889                         break;  /* just remove the option */
2890                 }
2891
2892                 /* message length validation */
2893                 if (len < sizeof(struct ip6_rthdr))
2894                         return (EINVAL);
2895                 rth = (struct ip6_rthdr *)buf;
2896                 rthlen = (rth->ip6r_len + 1) << 3;
2897                 if (len != rthlen)
2898                         return (EINVAL);
2899
2900                 switch (rth->ip6r_type) {
2901                 case IPV6_RTHDR_TYPE_0:
2902                         if (rth->ip6r_len == 0) /* must contain one addr */
2903                                 return (EINVAL);
2904                         if (rth->ip6r_len % 2) /* length must be even */
2905                                 return (EINVAL);
2906                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2907                                 return (EINVAL);
2908                         break;
2909                 default:
2910                         return (EINVAL);        /* not supported */
2911                 }
2912
2913                 /* turn off the previous option */
2914                 ip6_clearpktopts(opt, IPV6_RTHDR);
2915                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2916                 if (opt->ip6po_rthdr == NULL)
2917                         return (ENOBUFS);
2918                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2919
2920                 break;
2921         }
2922
2923         case IPV6_USE_MIN_MTU:
2924                 if (len != sizeof(int))
2925                         return (EINVAL);
2926                 minmtupolicy = *(int *)buf;
2927                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2928                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2929                     minmtupolicy != IP6PO_MINMTU_ALL) {
2930                         return (EINVAL);
2931                 }
2932                 opt->ip6po_minmtu = minmtupolicy;
2933                 break;
2934
2935         case IPV6_DONTFRAG:
2936                 if (len != sizeof(int))
2937                         return (EINVAL);
2938
2939                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2940                         /*
2941                          * we ignore this option for TCP sockets.
2942                          * (RFC3542 leaves this case unspecified.)
2943                          */
2944                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2945                 } else
2946                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2947                 break;
2948
2949         case IPV6_PREFER_TEMPADDR:
2950                 if (len != sizeof(int))
2951                         return (EINVAL);
2952                 preftemp = *(int *)buf;
2953                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2954                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2955                     preftemp != IP6PO_TEMPADDR_PREFER) {
2956                         return (EINVAL);
2957                 }
2958                 opt->ip6po_prefer_tempaddr = preftemp;
2959                 break;
2960
2961         default:
2962                 return (ENOPROTOOPT);
2963         } /* end of switch */
2964
2965         return (0);
2966 }
2967
2968 /*
2969  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
2970  * packet to the input queue of a specified interface.  Note that this
2971  * calls the output routine of the loopback "driver", but with an interface
2972  * pointer that might NOT be &loif -- easier than replicating that code here.
2973  */
2974 void
2975 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
2976 {
2977         struct mbuf *copym;
2978         struct ip6_hdr *ip6;
2979
2980         copym = m_copy(m, 0, M_COPYALL);
2981         if (copym == NULL)
2982                 return;
2983
2984         /*
2985          * Make sure to deep-copy IPv6 header portion in case the data
2986          * is in an mbuf cluster, so that we can safely override the IPv6
2987          * header portion later.
2988          */
2989         if (!M_WRITABLE(copym) ||
2990             copym->m_len < sizeof(struct ip6_hdr)) {
2991                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
2992                 if (copym == NULL)
2993                         return;
2994         }
2995         ip6 = mtod(copym, struct ip6_hdr *);
2996         /*
2997          * clear embedded scope identifiers if necessary.
2998          * in6_clearscope will touch the addresses only when necessary.
2999          */
3000         in6_clearscope(&ip6->ip6_src);
3001         in6_clearscope(&ip6->ip6_dst);
3002         if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3003                 copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3004                     CSUM_PSEUDO_HDR;
3005                 copym->m_pkthdr.csum_data = 0xffff;
3006         }
3007         if_simloop(ifp, copym, AF_INET6, 0);
3008 }
3009
3010 /*
3011  * Chop IPv6 header off from the payload.
3012  */
3013 static int
3014 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3015 {
3016         struct mbuf *mh;
3017         struct ip6_hdr *ip6;
3018
3019         ip6 = mtod(m, struct ip6_hdr *);
3020         if (m->m_len > sizeof(*ip6)) {
3021                 mh = m_gethdr(M_NOWAIT, MT_DATA);
3022                 if (mh == NULL) {
3023                         m_freem(m);
3024                         return ENOBUFS;
3025                 }
3026                 m_move_pkthdr(mh, m);
3027                 M_ALIGN(mh, sizeof(*ip6));
3028                 m->m_len -= sizeof(*ip6);
3029                 m->m_data += sizeof(*ip6);
3030                 mh->m_next = m;
3031                 m = mh;
3032                 m->m_len = sizeof(*ip6);
3033                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3034         }
3035         exthdrs->ip6e_ip6 = m;
3036         return 0;
3037 }
3038
3039 /*
3040  * Compute IPv6 extension header length.
3041  */
3042 int
3043 ip6_optlen(struct inpcb *in6p)
3044 {
3045         int len;
3046
3047         if (!in6p->in6p_outputopts)
3048                 return 0;
3049
3050         len = 0;
3051 #define elen(x) \
3052     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3053
3054         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3055         if (in6p->in6p_outputopts->ip6po_rthdr)
3056                 /* dest1 is valid with rthdr only */
3057                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3058         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3059         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3060         return len;
3061 #undef elen
3062 }