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  * 3. 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_ratelimit.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/if_llatbl.h>
  92 #include <net/netisr.h>
  93 #include <net/route.h>
  94 #include <net/pfil.h>
  95 #include <net/rss_config.h>
  96 #include <net/vnet.h>
  97
  98 #include <netinet/in.h>
  99 #include <netinet/in_var.h>
 100 #include <netinet/ip_var.h>
 101 #include <netinet6/in6_fib.h>
 102 #include <netinet6/in6_var.h>
 103 #include <netinet/ip6.h>
 104 #include <netinet/icmp6.h>
 105 #include <netinet6/ip6_var.h>
 106 #include <netinet/in_pcb.h>
 107 #include <netinet/tcp_var.h>
 108 #include <netinet6/nd6.h>
 109 #include <netinet6/in6_rss.h>
 110
 111 #include <netipsec/ipsec_support.h>
 112 #ifdef SCTP
 113 #include <netinet/sctp.h>
 114 #include <netinet/sctp_crc32.h>
 115 #endif
 116
 117 #include <netinet6/ip6protosw.h>
 118 #include <netinet6/scope6_var.h>
 119
 120 #ifdef FLOWTABLE
 121 #include <net/flowtable.h>
 122 #endif
 123
 124 extern int in6_mcast_loop;
 125
 126 struct ip6_exthdrs {
 127         struct mbuf *ip6e_ip6;
 128         struct mbuf *ip6e_hbh;
 129         struct mbuf *ip6e_dest1;
 130         struct mbuf *ip6e_rthdr;
 131         struct mbuf *ip6e_dest2;
 132 };
 133
 134 static MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
 135
 136 static int ip6_pcbopt(int, u_char *, int, struct ip6_pktopts **,
 137                            struct ucred *, int);
 138 static int ip6_pcbopts(struct ip6_pktopts **, struct mbuf *,
 139         struct socket *, struct sockopt *);
 140 static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
 141 static int ip6_setpktopt(int, u_char *, int, struct ip6_pktopts *,
 142         struct ucred *, int, int, int);
 143
 144 static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
 145 static int ip6_insertfraghdr(struct mbuf *, struct mbuf *, int,
 146         struct ip6_frag **);
 147 static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
 148 static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
 149 static int ip6_getpmtu(struct route_in6 *, int,
 150         struct ifnet *, const struct in6_addr *, u_long *, int *, u_int,
 151         u_int);
 152 static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
 153         u_long *, int *, u_int);
 154 static int ip6_getpmtu_ctl(u_int, const struct in6_addr *, u_long *);
 155 static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
 156
 157
 158 /*
 159  * Make an extension header from option data.  hp is the source, and
 160  * mp is the destination.
 161  */
 162 #define MAKE_EXTHDR(hp, mp)                                             \
 163     do {                                                                \
 164         if (hp) {                                                       \
 165                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 166                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 167                     ((eh)->ip6e_len + 1) << 3);                         \
 168                 if (error)                                              \
 169                         goto freehdrs;                                  \
 170         }                                                               \
 171     } while (/*CONSTCOND*/ 0)
 172
 173 /*
 174  * Form a chain of extension headers.
 175  * m is the extension header mbuf
 176  * mp is the previous mbuf in the chain
 177  * p is the next header
 178  * i is the type of option.
 179  */
 180 #define MAKE_CHAIN(m, mp, p, i)\
 181     do {\
 182         if (m) {\
 183                 if (!hdrsplit) \
 184                         panic("assumption failed: hdr not split"); \
 185                 *mtod((m), u_char *) = *(p);\
 186                 *(p) = (i);\
 187                 p = mtod((m), u_char *);\
 188                 (m)->m_next = (mp)->m_next;\
 189                 (mp)->m_next = (m);\
 190                 (mp) = (m);\
 191         }\
 192     } while (/*CONSTCOND*/ 0)
 193
 194 void
 195 in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset)
 196 {
 197         u_short csum;
 198
 199         csum = in_cksum_skip(m, offset + plen, offset);
 200         if (m->m_pkthdr.csum_flags & CSUM_UDP_IPV6 && csum == 0)
 201                 csum = 0xffff;
 202         offset += m->m_pkthdr.csum_data;        /* checksum offset */
 203
 204         if (offset + sizeof(u_short) > m->m_len) {
 205                 printf("%s: delayed m_pullup, m->len: %d plen %u off %u "
 206                     "csum_flags=%b\n", __func__, m->m_len, plen, offset,
 207                     (int)m->m_pkthdr.csum_flags, CSUM_BITS);
 208                 /*
 209                  * XXX this should not happen, but if it does, the correct
 210                  * behavior may be to insert the checksum in the appropriate
 211                  * next mbuf in the chain.
 212                  */
 213                 return;
 214         }
 215         *(u_short *)(m->m_data + offset) = csum;
 216 }
 217
 218 int
 219 ip6_fragment(struct ifnet *ifp, struct mbuf *m0, int hlen, u_char nextproto,
 220     int fraglen , uint32_t id)
 221 {
 222         struct mbuf *m, **mnext, *m_frgpart;
 223         struct ip6_hdr *ip6, *mhip6;
 224         struct ip6_frag *ip6f;
 225         int off;
 226         int error;
 227         int tlen = m0->m_pkthdr.len;
 228
 229         KASSERT((fraglen % 8 == 0), ("Fragment length must be a multiple of 8"));
 230
 231         m = m0;
 232         ip6 = mtod(m, struct ip6_hdr *);
 233         mnext = &m->m_nextpkt;
 234
 235         for (off = hlen; off < tlen; off += fraglen) {
 236                 m = m_gethdr(M_NOWAIT, MT_DATA);
 237                 if (!m) {
 238                         IP6STAT_INC(ip6s_odropped);
 239                         return (ENOBUFS);
 240                 }
 241                 m->m_flags = m0->m_flags & M_COPYFLAGS;
 242                 *mnext = m;
 243                 mnext = &m->m_nextpkt;
 244                 m->m_data += max_linkhdr;
 245                 mhip6 = mtod(m, struct ip6_hdr *);
 246                 *mhip6 = *ip6;
 247                 m->m_len = sizeof(*mhip6);
 248                 error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
 249                 if (error) {
 250                         IP6STAT_INC(ip6s_odropped);
 251                         return (error);
 252                 }
 253                 ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
 254                 if (off + fraglen >= tlen)
 255                         fraglen = tlen - off;
 256                 else
 257                         ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
 258                 mhip6->ip6_plen = htons((u_short)(fraglen + hlen +
 259                     sizeof(*ip6f) - sizeof(struct ip6_hdr)));
 260                 if ((m_frgpart = m_copym(m0, off, fraglen, M_NOWAIT)) == NULL) {
 261                         IP6STAT_INC(ip6s_odropped);
 262                         return (ENOBUFS);
 263                 }
 264                 m_cat(m, m_frgpart);
 265                 m->m_pkthdr.len = fraglen + hlen + sizeof(*ip6f);
 266                 m->m_pkthdr.fibnum = m0->m_pkthdr.fibnum;
 267                 m->m_pkthdr.rcvif = NULL;
 268                 ip6f->ip6f_reserved = 0;
 269                 ip6f->ip6f_ident = id;
 270                 ip6f->ip6f_nxt = nextproto;
 271                 IP6STAT_INC(ip6s_ofragments);
 272                 in6_ifstat_inc(ifp, ifs6_out_fragcreat);
 273         }
 274
 275         return (0);
 276 }
 277
 278 /*
 279  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 280  * header (with pri, len, nxt, hlim, src, dst).
 281  * This function may modify ver and hlim only.
 282  * The mbuf chain containing the packet will be freed.
 283  * The mbuf opt, if present, will not be freed.
 284  * If route_in6 ro is present and has ro_rt initialized, route lookup would be
 285  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
 286  * then result of route lookup is stored in ro->ro_rt.
 287  *
 288  * type of "mtu": rt_mtu is u_long, ifnet.ifr_mtu is int, and
 289  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 290  * which is rt_mtu.
 291  *
 292  * ifpp - XXX: just for statistics
 293  */
 294 /*
 295  * XXX TODO: no flowid is assigned for outbound flows?
 296  */
 297 int
 298 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 299     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 300     struct ifnet **ifpp, struct inpcb *inp)
 301 {
 302         struct ip6_hdr *ip6;
 303         struct ifnet *ifp, *origifp;
 304         struct mbuf *m = m0;
 305         struct mbuf *mprev = NULL;
 306         int hlen, tlen, len;
 307         struct route_in6 ip6route;
 308         struct rtentry *rt = NULL;
 309         struct sockaddr_in6 *dst, src_sa, dst_sa;
 310         struct in6_addr odst;
 311         int error = 0;
 312         struct in6_ifaddr *ia = NULL;
 313         u_long mtu;
 314         int alwaysfrag, dontfrag;
 315         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 316         struct ip6_exthdrs exthdrs;
 317         struct in6_addr src0, dst0;
 318         u_int32_t zone;
 319         struct route_in6 *ro_pmtu = NULL;
 320         int hdrsplit = 0;
 321         int sw_csum, tso;
 322         int needfiblookup;
 323         uint32_t fibnum;
 324         struct m_tag *fwd_tag = NULL;
 325         uint32_t id;
 326
 327         if (inp != NULL) {
 328                 INP_LOCK_ASSERT(inp);
 329                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
 330                 if ((flags & IP_NODEFAULTFLOWID) == 0) {
 331                         /* unconditionally set flowid */
 332                         m->m_pkthdr.flowid = inp->inp_flowid;
 333                         M_HASHTYPE_SET(m, inp->inp_flowtype);
 334                 }
 335         }
 336
 337 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 338         /*
 339          * IPSec checking which handles several cases.
 340          * FAST IPSEC: We re-injected the packet.
 341          * XXX: need scope argument.
 342          */
 343         if (IPSEC_ENABLED(ipv6)) {
 344                 if ((error = IPSEC_OUTPUT(ipv6, m, inp)) != 0) {
 345                         if (error == EINPROGRESS)
 346                                 error = 0;
 347                         goto done;
 348                 }
 349         }
 350 #endif /* IPSEC */
 351
 352         bzero(&exthdrs, sizeof(exthdrs));
 353         if (opt) {
 354                 /* Hop-by-Hop options header */
 355                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 356                 /* Destination options header(1st part) */
 357                 if (opt->ip6po_rthdr) {
 358                         /*
 359                          * Destination options header(1st part)
 360                          * This only makes sense with a routing header.
 361                          * See Section 9.2 of RFC 3542.
 362                          * Disabling this part just for MIP6 convenience is
 363                          * a bad idea.  We need to think carefully about a
 364                          * way to make the advanced API coexist with MIP6
 365                          * options, which might automatically be inserted in
 366                          * the kernel.
 367                          */
 368                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 369                 }
 370                 /* Routing header */
 371                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 372                 /* Destination options header(2nd part) */
 373                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 374         }
 375
 376         /*
 377          * Calculate the total length of the extension header chain.
 378          * Keep the length of the unfragmentable part for fragmentation.
 379          */
 380         optlen = 0;
 381         if (exthdrs.ip6e_hbh)
 382                 optlen += exthdrs.ip6e_hbh->m_len;
 383         if (exthdrs.ip6e_dest1)
 384                 optlen += exthdrs.ip6e_dest1->m_len;
 385         if (exthdrs.ip6e_rthdr)
 386                 optlen += exthdrs.ip6e_rthdr->m_len;
 387         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 388
 389         /* NOTE: we don't add AH/ESP length here (done in ip6_ipsec_output) */
 390         if (exthdrs.ip6e_dest2)
 391                 optlen += exthdrs.ip6e_dest2->m_len;
 392
 393         /*
 394          * If there is at least one extension header,
 395          * separate IP6 header from the payload.
 396          */
 397         if (optlen && !hdrsplit) {
 398                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 399                         m = NULL;
 400                         goto freehdrs;
 401                 }
 402                 m = exthdrs.ip6e_ip6;
 403                 hdrsplit++;
 404         }
 405
 406         ip6 = mtod(m, struct ip6_hdr *);
 407
 408         /* adjust mbuf packet header length */
 409         m->m_pkthdr.len += optlen;
 410         plen = m->m_pkthdr.len - sizeof(*ip6);
 411
 412         /* If this is a jumbo payload, insert a jumbo payload option. */
 413         if (plen > IPV6_MAXPACKET) {
 414                 if (!hdrsplit) {
 415                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 416                                 m = NULL;
 417                                 goto freehdrs;
 418                         }
 419                         m = exthdrs.ip6e_ip6;
 420                         hdrsplit++;
 421                 }
 422                 /* adjust pointer */
 423                 ip6 = mtod(m, struct ip6_hdr *);
 424                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 425                         goto freehdrs;
 426                 ip6->ip6_plen = 0;
 427         } else
 428                 ip6->ip6_plen = htons(plen);
 429
 430         /*
 431          * Concatenate headers and fill in next header fields.
 432          * Here we have, on "m"
 433          *      IPv6 payload
 434          * and we insert headers accordingly.  Finally, we should be getting:
 435          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 436          *
 437          * during the header composing process, "m" points to IPv6 header.
 438          * "mprev" points to an extension header prior to esp.
 439          */
 440         u_char *nexthdrp = &ip6->ip6_nxt;
 441         mprev = m;
 442
 443         /*
 444          * we treat dest2 specially.  this makes IPsec processing
 445          * much easier.  the goal here is to make mprev point the
 446          * mbuf prior to dest2.
 447          *
 448          * result: IPv6 dest2 payload
 449          * m and mprev will point to IPv6 header.
 450          */
 451         if (exthdrs.ip6e_dest2) {
 452                 if (!hdrsplit)
 453                         panic("assumption failed: hdr not split");
 454                 exthdrs.ip6e_dest2->m_next = m->m_next;
 455                 m->m_next = exthdrs.ip6e_dest2;
 456                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 457                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 458         }
 459
 460         /*
 461          * result: IPv6 hbh dest1 rthdr dest2 payload
 462          * m will point to IPv6 header.  mprev will point to the
 463          * extension header prior to dest2 (rthdr in the above case).
 464          */
 465         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 466         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 467                    IPPROTO_DSTOPTS);
 468         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 469                    IPPROTO_ROUTING);
 470
 471         /*
 472          * If there is a routing header, discard the packet.
 473          */
 474         if (exthdrs.ip6e_rthdr) {
 475                  error = EINVAL;
 476                  goto bad;
 477         }
 478
 479         /* Source address validation */
 480         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 481             (flags & IPV6_UNSPECSRC) == 0) {
 482                 error = EOPNOTSUPP;
 483                 IP6STAT_INC(ip6s_badscope);
 484                 goto bad;
 485         }
 486         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 487                 error = EOPNOTSUPP;
 488                 IP6STAT_INC(ip6s_badscope);
 489                 goto bad;
 490         }
 491
 492         IP6STAT_INC(ip6s_localout);
 493
 494         /*
 495          * Route packet.
 496          */
 497         if (ro == NULL) {
 498                 ro = &ip6route;
 499                 bzero((caddr_t)ro, sizeof(*ro));
 500         }
 501         ro_pmtu = ro;
 502         if (opt && opt->ip6po_rthdr)
 503                 ro = &opt->ip6po_route;
 504         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 505 #ifdef FLOWTABLE
 506         if (ro->ro_rt == NULL)
 507                 (void )flowtable_lookup(AF_INET6, m, (struct route *)ro);
 508 #endif
 509         fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
 510 again:
 511         /*
 512          * if specified, try to fill in the traffic class field.
 513          * do not override if a non-zero value is already set.
 514          * we check the diffserv field and the ecn field separately.
 515          */
 516         if (opt && opt->ip6po_tclass >= 0) {
 517                 int mask = 0;
 518
 519                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 520                         mask |= 0xfc;
 521                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 522                         mask |= 0x03;
 523                 if (mask != 0)
 524                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 525         }
 526
 527         /* fill in or override the hop limit field, if necessary. */
 528         if (opt && opt->ip6po_hlim != -1)
 529                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 530         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 531                 if (im6o != NULL)
 532                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 533                 else
 534                         ip6->ip6_hlim = V_ip6_defmcasthlim;
 535         }
 536         /*
 537          * Validate route against routing table additions;
 538          * a better/more specific route might have been added.
 539          * Make sure address family is set in route.
 540          */
 541         if (inp) {
 542                 ro->ro_dst.sin6_family = AF_INET6;
 543                 RT_VALIDATE((struct route *)ro, &inp->inp_rt_cookie, fibnum);
 544         }
 545         if (ro->ro_rt && fwd_tag == NULL && (ro->ro_rt->rt_flags & RTF_UP) &&
 546             ro->ro_dst.sin6_family == AF_INET6 &&
 547             IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &ip6->ip6_dst)) {
 548                 rt = ro->ro_rt;
 549                 ifp = ro->ro_rt->rt_ifp;
 550         } else {
 551                 if (ro->ro_lle)
 552                         LLE_FREE(ro->ro_lle);   /* zeros ro_lle */
 553                 ro->ro_lle = NULL;
 554                 if (fwd_tag == NULL) {
 555                         bzero(&dst_sa, sizeof(dst_sa));
 556                         dst_sa.sin6_family = AF_INET6;
 557                         dst_sa.sin6_len = sizeof(dst_sa);
 558                         dst_sa.sin6_addr = ip6->ip6_dst;
 559                 }
 560                 error = in6_selectroute_fib(&dst_sa, opt, im6o, ro, &ifp,
 561                     &rt, fibnum);
 562                 if (error != 0) {
 563                         if (ifp != NULL)
 564                                 in6_ifstat_inc(ifp, ifs6_out_discard);
 565                         goto bad;
 566                 }
 567         }
 568         if (rt == NULL) {
 569                 /*
 570                  * If in6_selectroute() does not return a route entry,
 571                  * dst may not have been updated.
 572                  */
 573                 *dst = dst_sa;  /* XXX */
 574         }
 575
 576         /*
 577          * then rt (for unicast) and ifp must be non-NULL valid values.
 578          */
 579         if ((flags & IPV6_FORWARDING) == 0) {
 580                 /* XXX: the FORWARDING flag can be set for mrouting. */
 581                 in6_ifstat_inc(ifp, ifs6_out_request);
 582         }
 583         if (rt != NULL) {
 584                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 585                 counter_u64_add(rt->rt_pksent, 1);
 586         }
 587
 588
 589         /*
 590          * The outgoing interface must be in the zone of source and
 591          * destination addresses.
 592          */
 593         origifp = ifp;
 594
 595         src0 = ip6->ip6_src;
 596         if (in6_setscope(&src0, origifp, &zone))
 597                 goto badscope;
 598         bzero(&src_sa, sizeof(src_sa));
 599         src_sa.sin6_family = AF_INET6;
 600         src_sa.sin6_len = sizeof(src_sa);
 601         src_sa.sin6_addr = ip6->ip6_src;
 602         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 603                 goto badscope;
 604
 605         dst0 = ip6->ip6_dst;
 606         if (in6_setscope(&dst0, origifp, &zone))
 607                 goto badscope;
 608         /* re-initialize to be sure */
 609         bzero(&dst_sa, sizeof(dst_sa));
 610         dst_sa.sin6_family = AF_INET6;
 611         dst_sa.sin6_len = sizeof(dst_sa);
 612         dst_sa.sin6_addr = ip6->ip6_dst;
 613         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 614                 goto badscope;
 615         }
 616
 617         /* We should use ia_ifp to support the case of
 618          * sending packets to an address of our own.
 619          */
 620         if (ia != NULL && ia->ia_ifp)
 621                 ifp = ia->ia_ifp;
 622
 623         /* scope check is done. */
 624         goto routefound;
 625
 626   badscope:
 627         IP6STAT_INC(ip6s_badscope);
 628         in6_ifstat_inc(origifp, ifs6_out_discard);
 629         if (error == 0)
 630                 error = EHOSTUNREACH; /* XXX */
 631         goto bad;
 632
 633   routefound:
 634         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 635                 if (opt && opt->ip6po_nextroute.ro_rt) {
 636                         /*
 637                          * The nexthop is explicitly specified by the
 638                          * application.  We assume the next hop is an IPv6
 639                          * address.
 640                          */
 641                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 642                 }
 643                 else if ((rt->rt_flags & RTF_GATEWAY))
 644                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 645         }
 646
 647         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 648                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 649         } else {
 650                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 651                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 652                 /*
 653                  * Confirm that the outgoing interface supports multicast.
 654                  */
 655                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 656                         IP6STAT_INC(ip6s_noroute);
 657                         in6_ifstat_inc(ifp, ifs6_out_discard);
 658                         error = ENETUNREACH;
 659                         goto bad;
 660                 }
 661                 if ((im6o == NULL && in6_mcast_loop) ||
 662                     (im6o && im6o->im6o_multicast_loop)) {
 663                         /*
 664                          * Loop back multicast datagram if not expressly
 665                          * forbidden to do so, even if we have not joined
 666                          * the address; protocols will filter it later,
 667                          * thus deferring a hash lookup and lock acquisition
 668                          * at the expense of an m_copym().
 669                          */
 670                         ip6_mloopback(ifp, m);
 671                 } else {
 672                         /*
 673                          * If we are acting as a multicast router, perform
 674                          * multicast forwarding as if the packet had just
 675                          * arrived on the interface to which we are about
 676                          * to send.  The multicast forwarding function
 677                          * recursively calls this function, using the
 678                          * IPV6_FORWARDING flag to prevent infinite recursion.
 679                          *
 680                          * Multicasts that are looped back by ip6_mloopback(),
 681                          * above, will be forwarded by the ip6_input() routine,
 682                          * if necessary.
 683                          */
 684                         if (V_ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 685                                 /*
 686                                  * XXX: ip6_mforward expects that rcvif is NULL
 687                                  * when it is called from the originating path.
 688                                  * However, it may not always be the case.
 689                                  */
 690                                 m->m_pkthdr.rcvif = NULL;
 691                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 692                                         m_freem(m);
 693                                         goto done;
 694                                 }
 695                         }
 696                 }
 697                 /*
 698                  * Multicasts with a hoplimit of zero may be looped back,
 699                  * above, but must not be transmitted on a network.
 700                  * Also, multicasts addressed to the loopback interface
 701                  * are not sent -- the above call to ip6_mloopback() will
 702                  * loop back a copy if this host actually belongs to the
 703                  * destination group on the loopback interface.
 704                  */
 705                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 706                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 707                         m_freem(m);
 708                         goto done;
 709                 }
 710         }
 711
 712         /*
 713          * Fill the outgoing inteface to tell the upper layer
 714          * to increment per-interface statistics.
 715          */
 716         if (ifpp)
 717                 *ifpp = ifp;
 718
 719         /* Determine path MTU. */
 720         if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &ip6->ip6_dst,
 721                     &mtu, &alwaysfrag, fibnum, *nexthdrp)) != 0)
 722                 goto bad;
 723
 724         /*
 725          * The caller of this function may specify to use the minimum MTU
 726          * in some cases.
 727          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 728          * setting.  The logic is a bit complicated; by default, unicast
 729          * packets will follow path MTU while multicast packets will be sent at
 730          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 731          * including unicast ones will be sent at the minimum MTU.  Multicast
 732          * packets will always be sent at the minimum MTU unless
 733          * IP6PO_MINMTU_DISABLE is explicitly specified.
 734          * See RFC 3542 for more details.
 735          */
 736         if (mtu > IPV6_MMTU) {
 737                 if ((flags & IPV6_MINMTU))
 738                         mtu = IPV6_MMTU;
 739                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 740                         mtu = IPV6_MMTU;
 741                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 742                          (opt == NULL ||
 743                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 744                         mtu = IPV6_MMTU;
 745                 }
 746         }
 747
 748         /*
 749          * clear embedded scope identifiers if necessary.
 750          * in6_clearscope will touch the addresses only when necessary.
 751          */
 752         in6_clearscope(&ip6->ip6_src);
 753         in6_clearscope(&ip6->ip6_dst);
 754
 755         /*
 756          * If the outgoing packet contains a hop-by-hop options header,
 757          * it must be examined and processed even by the source node.
 758          * (RFC 2460, section 4.)
 759          */
 760         if (exthdrs.ip6e_hbh) {
 761                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 762                 u_int32_t dummy; /* XXX unused */
 763                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 764
 765 #ifdef DIAGNOSTIC
 766                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 767                         panic("ip6e_hbh is not contiguous");
 768 #endif
 769                 /*
 770                  *  XXX: if we have to send an ICMPv6 error to the sender,
 771                  *       we need the M_LOOP flag since icmp6_error() expects
 772                  *       the IPv6 and the hop-by-hop options header are
 773                  *       contiguous unless the flag is set.
 774                  */
 775                 m->m_flags |= M_LOOP;
 776                 m->m_pkthdr.rcvif = ifp;
 777                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 778                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 779                     &dummy, &plen) < 0) {
 780                         /* m was already freed at this point */
 781                         error = EINVAL;/* better error? */
 782                         goto done;
 783                 }
 784                 m->m_flags &= ~M_LOOP; /* XXX */
 785                 m->m_pkthdr.rcvif = NULL;
 786         }
 787
 788         /* Jump over all PFIL processing if hooks are not active. */
 789         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
 790                 goto passout;
 791
 792         odst = ip6->ip6_dst;
 793         /* Run through list of hooks for output packets. */
 794         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 795         if (error != 0 || m == NULL)
 796                 goto done;
 797         /* adjust pointer */
 798         ip6 = mtod(m, struct ip6_hdr *);
 799
 800         needfiblookup = 0;
 801         /* See if destination IP address was changed by packet filter. */
 802         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 803                 m->m_flags |= M_SKIP_FIREWALL;
 804                 /* If destination is now ourself drop to ip6_input(). */
 805                 if (in6_localip(&ip6->ip6_dst)) {
 806                         m->m_flags |= M_FASTFWD_OURS;
 807                         if (m->m_pkthdr.rcvif == NULL)
 808                                 m->m_pkthdr.rcvif = V_loif;
 809                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 810                                 m->m_pkthdr.csum_flags |=
 811                                     CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 812                                 m->m_pkthdr.csum_data = 0xffff;
 813                         }
 814 #ifdef SCTP
 815                         if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 816                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 817 #endif
 818                         error = netisr_queue(NETISR_IPV6, m);
 819                         goto done;
 820                 } else {
 821                         RO_RTFREE(ro);
 822                         needfiblookup = 1; /* Redo the routing table lookup. */
 823                         if (ro->ro_lle)
 824                                 LLE_FREE(ro->ro_lle);   /* zeros ro_lle */
 825                         ro->ro_lle = NULL;
 826                 }
 827         }
 828         /* See if fib was changed by packet filter. */
 829         if (fibnum != M_GETFIB(m)) {
 830                 m->m_flags |= M_SKIP_FIREWALL;
 831                 fibnum = M_GETFIB(m);
 832                 RO_RTFREE(ro);
 833                 needfiblookup = 1;
 834                 if (ro->ro_lle)
 835                         LLE_FREE(ro->ro_lle);   /* zeros ro_lle */
 836                 ro->ro_lle = NULL;
 837         }
 838         if (needfiblookup)
 839                 goto again;
 840
 841         /* See if local, if yes, send it to netisr. */
 842         if (m->m_flags & M_FASTFWD_OURS) {
 843                 if (m->m_pkthdr.rcvif == NULL)
 844                         m->m_pkthdr.rcvif = V_loif;
 845                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
 846                         m->m_pkthdr.csum_flags |=
 847                             CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 848                         m->m_pkthdr.csum_data = 0xffff;
 849                 }
 850 #ifdef SCTP
 851                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 852                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 853 #endif
 854                 error = netisr_queue(NETISR_IPV6, m);
 855                 goto done;
 856         }
 857         /* Or forward to some other address? */
 858         if ((m->m_flags & M_IP6_NEXTHOP) &&
 859             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 860                 dst = (struct sockaddr_in6 *)&ro->ro_dst;
 861                 bcopy((fwd_tag+1), &dst_sa, sizeof(struct sockaddr_in6));
 862                 m->m_flags |= M_SKIP_FIREWALL;
 863                 m->m_flags &= ~M_IP6_NEXTHOP;
 864                 m_tag_delete(m, fwd_tag);
 865                 goto again;
 866         }
 867
 868 passout:
 869         /*
 870          * Send the packet to the outgoing interface.
 871          * If necessary, do IPv6 fragmentation before sending.
 872          *
 873          * the logic here is rather complex:
 874          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 875          * 1-a: send as is if tlen <= path mtu
 876          * 1-b: fragment if tlen > path mtu
 877          *
 878          * 2: if user asks us not to fragment (dontfrag == 1)
 879          * 2-a: send as is if tlen <= interface mtu
 880          * 2-b: error if tlen > interface mtu
 881          *
 882          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 883          *      always fragment
 884          *
 885          * 4: if dontfrag == 1 && alwaysfrag == 1
 886          *      error, as we cannot handle this conflicting request
 887          */
 888         sw_csum = m->m_pkthdr.csum_flags;
 889         if (!hdrsplit) {
 890                 tso = ((sw_csum & ifp->if_hwassist & CSUM_TSO) != 0) ? 1 : 0;
 891                 sw_csum &= ~ifp->if_hwassist;
 892         } else
 893                 tso = 0;
 894         /*
 895          * If we added extension headers, we will not do TSO and calculate the
 896          * checksums ourselves for now.
 897          * XXX-BZ  Need a framework to know when the NIC can handle it, even
 898          * with ext. hdrs.
 899          */
 900         if (sw_csum & CSUM_DELAY_DATA_IPV6) {
 901                 sw_csum &= ~CSUM_DELAY_DATA_IPV6;
 902                 in6_delayed_cksum(m, plen, sizeof(struct ip6_hdr));
 903         }
 904 #ifdef SCTP
 905         if (sw_csum & CSUM_SCTP_IPV6) {
 906                 sw_csum &= ~CSUM_SCTP_IPV6;
 907                 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 908         }
 909 #endif
 910         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
 911         tlen = m->m_pkthdr.len;
 912
 913         if ((opt && (opt->ip6po_flags & IP6PO_DONTFRAG)) || tso)
 914                 dontfrag = 1;
 915         else
 916                 dontfrag = 0;
 917         if (dontfrag && alwaysfrag) {   /* case 4 */
 918                 /* conflicting request - can't transmit */
 919                 error = EMSGSIZE;
 920                 goto bad;
 921         }
 922         if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) {      /* case 2-b */
 923                 /*
 924                  * Even if the DONTFRAG option is specified, we cannot send the
 925                  * packet when the data length is larger than the MTU of the
 926                  * outgoing interface.
 927                  * Notify the error by sending IPV6_PATHMTU ancillary data if
 928                  * application wanted to know the MTU value. Also return an
 929                  * error code (this is not described in the API spec).
 930                  */
 931                 if (inp != NULL)
 932                         ip6_notify_pmtu(inp, &dst_sa, (u_int32_t)mtu);
 933                 error = EMSGSIZE;
 934                 goto bad;
 935         }
 936
 937         /*
 938          * transmit packet without fragmentation
 939          */
 940         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 941                 struct in6_ifaddr *ia6;
 942
 943                 ip6 = mtod(m, struct ip6_hdr *);
 944                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 945                 if (ia6) {
 946                         /* Record statistics for this interface address. */
 947                         counter_u64_add(ia6->ia_ifa.ifa_opackets, 1);
 948                         counter_u64_add(ia6->ia_ifa.ifa_obytes,
 949                             m->m_pkthdr.len);
 950                         ifa_free(&ia6->ia_ifa);
 951                 }
 952 #ifdef RATELIMIT
 953                 if (inp != NULL) {
 954                         if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
 955                                 in_pcboutput_txrtlmt(inp, ifp, m);
 956                         /* stamp send tag on mbuf */
 957                         m->m_pkthdr.snd_tag = inp->inp_snd_tag;
 958                 } else {
 959                         m->m_pkthdr.snd_tag = NULL;
 960                 }
 961 #endif
 962                 error = nd6_output_ifp(ifp, origifp, m, dst,
 963                     (struct route *)ro);
 964 #ifdef RATELIMIT
 965                 /* check for route change */
 966                 if (error == EAGAIN)
 967                         in_pcboutput_eagain(inp);
 968 #endif
 969                 goto done;
 970         }
 971
 972         /*
 973          * try to fragment the packet.  case 1-b and 3
 974          */
 975         if (mtu < IPV6_MMTU) {
 976                 /* path MTU cannot be less than IPV6_MMTU */
 977                 error = EMSGSIZE;
 978                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 979                 goto bad;
 980         } else if (ip6->ip6_plen == 0) {
 981                 /* jumbo payload cannot be fragmented */
 982                 error = EMSGSIZE;
 983                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 984                 goto bad;
 985         } else {
 986                 u_char nextproto;
 987
 988                 /*
 989                  * Too large for the destination or interface;
 990                  * fragment if possible.
 991                  * Must be able to put at least 8 bytes per fragment.
 992                  */
 993                 hlen = unfragpartlen;
 994                 if (mtu > IPV6_MAXPACKET)
 995                         mtu = IPV6_MAXPACKET;
 996
 997                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 998                 if (len < 8) {
 999                         error = EMSGSIZE;
1000                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
1001                         goto bad;
1002                 }
1003
1004                 /*
1005                  * If the interface will not calculate checksums on
1006                  * fragmented packets, then do it here.
1007                  * XXX-BZ handle the hw offloading case.  Need flags.
1008                  */
1009                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
1010                         in6_delayed_cksum(m, plen, hlen);
1011                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
1012                 }
1013 #ifdef SCTP
1014                 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
1015                         sctp_delayed_cksum(m, hlen);
1016                         m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
1017                 }
1018 #endif
1019                 /*
1020                  * Change the next header field of the last header in the
1021                  * unfragmentable part.
1022                  */
1023                 if (exthdrs.ip6e_rthdr) {
1024                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
1025                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
1026                 } else if (exthdrs.ip6e_dest1) {
1027                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
1028                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
1029                 } else if (exthdrs.ip6e_hbh) {
1030                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
1031                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
1032                 } else {
1033                         nextproto = ip6->ip6_nxt;
1034                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
1035                 }
1036
1037                 /*
1038                  * Loop through length of segment after first fragment,
1039                  * make new header and copy data of each part and link onto
1040                  * chain.
1041                  */
1042                 m0 = m;
1043                 id = htonl(ip6_randomid());
1044                 if ((error = ip6_fragment(ifp, m, hlen, nextproto, len, id)))
1045                         goto sendorfree;
1046
1047                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1048         }
1049
1050         /*
1051          * Remove leading garbages.
1052          */
1053 sendorfree:
1054         m = m0->m_nextpkt;
1055         m0->m_nextpkt = 0;
1056         m_freem(m0);
1057         for (m0 = m; m; m = m0) {
1058                 m0 = m->m_nextpkt;
1059                 m->m_nextpkt = 0;
1060                 if (error == 0) {
1061                         /* Record statistics for this interface address. */
1062                         if (ia) {
1063                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
1064                                 counter_u64_add(ia->ia_ifa.ifa_obytes,
1065                                     m->m_pkthdr.len);
1066                         }
1067 #ifdef RATELIMIT
1068                         if (inp != NULL) {
1069                                 if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
1070                                         in_pcboutput_txrtlmt(inp, ifp, m);
1071                                 /* stamp send tag on mbuf */
1072                                 m->m_pkthdr.snd_tag = inp->inp_snd_tag;
1073                         } else {
1074                                 m->m_pkthdr.snd_tag = NULL;
1075                         }
1076 #endif
1077                         error = nd6_output_ifp(ifp, origifp, m, dst,
1078                             (struct route *)ro);
1079 #ifdef RATELIMIT
1080                         /* check for route change */
1081                         if (error == EAGAIN)
1082                                 in_pcboutput_eagain(inp);
1083 #endif
1084                 } else
1085                         m_freem(m);
1086         }
1087
1088         if (error == 0)
1089                 IP6STAT_INC(ip6s_fragmented);
1090
1091 done:
1092         if (ro == &ip6route)
1093                 RO_RTFREE(ro);
1094         return (error);
1095
1096 freehdrs:
1097         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1098         m_freem(exthdrs.ip6e_dest1);
1099         m_freem(exthdrs.ip6e_rthdr);
1100         m_freem(exthdrs.ip6e_dest2);
1101         /* FALLTHROUGH */
1102 bad:
1103         if (m)
1104                 m_freem(m);
1105         goto done;
1106 }
1107
1108 static int
1109 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1110 {
1111         struct mbuf *m;
1112
1113         if (hlen > MCLBYTES)
1114                 return (ENOBUFS); /* XXX */
1115
1116         if (hlen > MLEN)
1117                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1118         else
1119                 m = m_get(M_NOWAIT, MT_DATA);
1120         if (m == NULL)
1121                 return (ENOBUFS);
1122         m->m_len = hlen;
1123         if (hdr)
1124                 bcopy(hdr, mtod(m, caddr_t), hlen);
1125
1126         *mp = m;
1127         return (0);
1128 }
1129
1130 /*
1131  * Insert jumbo payload option.
1132  */
1133 static int
1134 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1135 {
1136         struct mbuf *mopt;
1137         u_char *optbuf;
1138         u_int32_t v;
1139
1140 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1141
1142         /*
1143          * If there is no hop-by-hop options header, allocate new one.
1144          * If there is one but it doesn't have enough space to store the
1145          * jumbo payload option, allocate a cluster to store the whole options.
1146          * Otherwise, use it to store the options.
1147          */
1148         if (exthdrs->ip6e_hbh == NULL) {
1149                 mopt = m_get(M_NOWAIT, MT_DATA);
1150                 if (mopt == NULL)
1151                         return (ENOBUFS);
1152                 mopt->m_len = JUMBOOPTLEN;
1153                 optbuf = mtod(mopt, u_char *);
1154                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1155                 exthdrs->ip6e_hbh = mopt;
1156         } else {
1157                 struct ip6_hbh *hbh;
1158
1159                 mopt = exthdrs->ip6e_hbh;
1160                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1161                         /*
1162                          * XXX assumption:
1163                          * - exthdrs->ip6e_hbh is not referenced from places
1164                          *   other than exthdrs.
1165                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1166                          */
1167                         int oldoptlen = mopt->m_len;
1168                         struct mbuf *n;
1169
1170                         /*
1171                          * XXX: give up if the whole (new) hbh header does
1172                          * not fit even in an mbuf cluster.
1173                          */
1174                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1175                                 return (ENOBUFS);
1176
1177                         /*
1178                          * As a consequence, we must always prepare a cluster
1179                          * at this point.
1180                          */
1181                         n = m_getcl(M_NOWAIT, MT_DATA, 0);
1182                         if (n == NULL)
1183                                 return (ENOBUFS);
1184                         n->m_len = oldoptlen + JUMBOOPTLEN;
1185                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1186                             oldoptlen);
1187                         optbuf = mtod(n, caddr_t) + oldoptlen;
1188                         m_freem(mopt);
1189                         mopt = exthdrs->ip6e_hbh = n;
1190                 } else {
1191                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1192                         mopt->m_len += JUMBOOPTLEN;
1193                 }
1194                 optbuf[0] = IP6OPT_PADN;
1195                 optbuf[1] = 1;
1196
1197                 /*
1198                  * Adjust the header length according to the pad and
1199                  * the jumbo payload option.
1200                  */
1201                 hbh = mtod(mopt, struct ip6_hbh *);
1202                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1203         }
1204
1205         /* fill in the option. */
1206         optbuf[2] = IP6OPT_JUMBO;
1207         optbuf[3] = 4;
1208         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1209         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1210
1211         /* finally, adjust the packet header length */
1212         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1213
1214         return (0);
1215 #undef JUMBOOPTLEN
1216 }
1217
1218 /*
1219  * Insert fragment header and copy unfragmentable header portions.
1220  */
1221 static int
1222 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1223     struct ip6_frag **frghdrp)
1224 {
1225         struct mbuf *n, *mlast;
1226
1227         if (hlen > sizeof(struct ip6_hdr)) {
1228                 n = m_copym(m0, sizeof(struct ip6_hdr),
1229                     hlen - sizeof(struct ip6_hdr), M_NOWAIT);
1230                 if (n == NULL)
1231                         return (ENOBUFS);
1232                 m->m_next = n;
1233         } else
1234                 n = m;
1235
1236         /* Search for the last mbuf of unfragmentable part. */
1237         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1238                 ;
1239
1240         if (M_WRITABLE(mlast) &&
1241             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1242                 /* use the trailing space of the last mbuf for the fragment hdr */
1243                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1244                     mlast->m_len);
1245                 mlast->m_len += sizeof(struct ip6_frag);
1246                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1247         } else {
1248                 /* allocate a new mbuf for the fragment header */
1249                 struct mbuf *mfrg;
1250
1251                 mfrg = m_get(M_NOWAIT, MT_DATA);
1252                 if (mfrg == NULL)
1253                         return (ENOBUFS);
1254                 mfrg->m_len = sizeof(struct ip6_frag);
1255                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1256                 mlast->m_next = mfrg;
1257         }
1258
1259         return (0);
1260 }
1261
1262 /*
1263  * Calculates IPv6 path mtu for destination @dst.
1264  * Resulting MTU is stored in @mtup.
1265  *
1266  * Returns 0 on success.
1267  */
1268 static int
1269 ip6_getpmtu_ctl(u_int fibnum, const struct in6_addr *dst, u_long *mtup)
1270 {
1271         struct nhop6_extended nh6;
1272         struct in6_addr kdst;
1273         uint32_t scopeid;
1274         struct ifnet *ifp;
1275         u_long mtu;
1276         int error;
1277
1278         in6_splitscope(dst, &kdst, &scopeid);
1279         if (fib6_lookup_nh_ext(fibnum, &kdst, scopeid, NHR_REF, 0, &nh6) != 0)
1280                 return (EHOSTUNREACH);
1281
1282         ifp = nh6.nh_ifp;
1283         mtu = nh6.nh_mtu;
1284
1285         error = ip6_calcmtu(ifp, dst, mtu, mtup, NULL, 0);
1286         fib6_free_nh_ext(fibnum, &nh6);
1287
1288         return (error);
1289 }
1290
1291 /*
1292  * Calculates IPv6 path MTU for @dst based on transmit @ifp,
1293  * and cached data in @ro_pmtu.
1294  * MTU from (successful) route lookup is saved (along with dst)
1295  * inside @ro_pmtu to avoid subsequent route lookups after packet
1296  * filter processing.
1297  *
1298  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1299  * Returns 0 on success.
1300  */
1301 static int
1302 ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
1303     struct ifnet *ifp, const struct in6_addr *dst, u_long *mtup,
1304     int *alwaysfragp, u_int fibnum, u_int proto)
1305 {
1306         struct nhop6_basic nh6;
1307         struct in6_addr kdst;
1308         uint32_t scopeid;
1309         struct sockaddr_in6 *sa6_dst;
1310         u_long mtu;
1311
1312         mtu = 0;
1313         if (do_lookup) {
1314
1315                 /*
1316                  * Here ro_pmtu has final destination address, while
1317                  * ro might represent immediate destination.
1318                  * Use ro_pmtu destination since mtu might differ.
1319                  */
1320                 sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1321                 if (!IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))
1322                         ro_pmtu->ro_mtu = 0;
1323
1324                 if (ro_pmtu->ro_mtu == 0) {
1325                         bzero(sa6_dst, sizeof(*sa6_dst));
1326                         sa6_dst->sin6_family = AF_INET6;
1327                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1328                         sa6_dst->sin6_addr = *dst;
1329
1330                         in6_splitscope(dst, &kdst, &scopeid);
1331                         if (fib6_lookup_nh_basic(fibnum, &kdst, scopeid, 0, 0,
1332                             &nh6) == 0)
1333                                 ro_pmtu->ro_mtu = nh6.nh_mtu;
1334                 }
1335
1336                 mtu = ro_pmtu->ro_mtu;
1337         }
1338
1339         if (ro_pmtu->ro_rt)
1340                 mtu = ro_pmtu->ro_rt->rt_mtu;
1341
1342         return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp, proto));
1343 }
1344
1345 /*
1346  * Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
1347  * hostcache data for @dst.
1348  * Stores mtu and always-frag value into @mtup and @alwaysfragp.
1349  *
1350  * Returns 0 on success.
1351  */
1352 static int
1353 ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
1354     u_long *mtup, int *alwaysfragp, u_int proto)
1355 {
1356         u_long mtu = 0;
1357         int alwaysfrag = 0;
1358         int error = 0;
1359
1360         if (rt_mtu > 0) {
1361                 u_int32_t ifmtu;
1362                 struct in_conninfo inc;
1363
1364                 bzero(&inc, sizeof(inc));
1365                 inc.inc_flags |= INC_ISIPV6;
1366                 inc.inc6_faddr = *dst;
1367
1368                 ifmtu = IN6_LINKMTU(ifp);
1369
1370                 /* TCP is known to react to pmtu changes so skip hc */
1371                 if (proto != IPPROTO_TCP)
1372                         mtu = tcp_hc_getmtu(&inc);
1373
1374                 if (mtu)
1375                         mtu = min(mtu, rt_mtu);
1376                 else
1377                         mtu = rt_mtu;
1378                 if (mtu == 0)
1379                         mtu = ifmtu;
1380                 else if (mtu < IPV6_MMTU) {
1381                         /*
1382                          * RFC2460 section 5, last paragraph:
1383                          * if we record ICMPv6 too big message with
1384                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1385                          * or smaller, with framgent header attached.
1386                          * (fragment header is needed regardless from the
1387                          * packet size, for translators to identify packets)
1388                          */
1389                         alwaysfrag = 1;
1390                         mtu = IPV6_MMTU;
1391                 }
1392         } else if (ifp) {
1393                 mtu = IN6_LINKMTU(ifp);
1394         } else
1395                 error = EHOSTUNREACH; /* XXX */
1396
1397         *mtup = mtu;
1398         if (alwaysfragp)
1399                 *alwaysfragp = alwaysfrag;
1400         return (error);
1401 }
1402
1403 /*
1404  * IP6 socket option processing.
1405  */
1406 int
1407 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1408 {
1409         int optdatalen, uproto;
1410         void *optdata;
1411         struct inpcb *in6p = sotoinpcb(so);
1412         int error, optval;
1413         int level, op, optname;
1414         int optlen;
1415         struct thread *td;
1416 #ifdef  RSS
1417         uint32_t rss_bucket;
1418         int retval;
1419 #endif
1420
1421 /*
1422  * Don't use more than a quarter of mbuf clusters.  N.B.:
1423  * nmbclusters is an int, but nmbclusters * MCLBYTES may overflow
1424  * on LP64 architectures, so cast to u_long to avoid undefined
1425  * behavior.  ILP32 architectures cannot have nmbclusters
1426  * large enough to overflow for other reasons.
1427  */
1428 #define IPV6_PKTOPTIONS_MBUF_LIMIT      ((u_long)nmbclusters * MCLBYTES / 4)
1429
1430         level = sopt->sopt_level;
1431         op = sopt->sopt_dir;
1432         optname = sopt->sopt_name;
1433         optlen = sopt->sopt_valsize;
1434         td = sopt->sopt_td;
1435         error = 0;
1436         optval = 0;
1437         uproto = (int)so->so_proto->pr_protocol;
1438
1439         if (level != IPPROTO_IPV6) {
1440                 error = EINVAL;
1441
1442                 if (sopt->sopt_level == SOL_SOCKET &&
1443                     sopt->sopt_dir == SOPT_SET) {
1444                         switch (sopt->sopt_name) {
1445                         case SO_REUSEADDR:
1446                                 INP_WLOCK(in6p);
1447                                 if ((so->so_options & SO_REUSEADDR) != 0)
1448                                         in6p->inp_flags2 |= INP_REUSEADDR;
1449                                 else
1450                                         in6p->inp_flags2 &= ~INP_REUSEADDR;
1451                                 INP_WUNLOCK(in6p);
1452                                 error = 0;
1453                                 break;
1454                         case SO_REUSEPORT:
1455                                 INP_WLOCK(in6p);
1456                                 if ((so->so_options & SO_REUSEPORT) != 0)
1457                                         in6p->inp_flags2 |= INP_REUSEPORT;
1458                                 else
1459                                         in6p->inp_flags2 &= ~INP_REUSEPORT;
1460                                 INP_WUNLOCK(in6p);
1461                                 error = 0;
1462                                 break;
1463                         case SO_SETFIB:
1464                                 INP_WLOCK(in6p);
1465                                 in6p->inp_inc.inc_fibnum = so->so_fibnum;
1466                                 INP_WUNLOCK(in6p);
1467                                 error = 0;
1468                                 break;
1469                         case SO_MAX_PACING_RATE:
1470 #ifdef RATELIMIT
1471                                 INP_WLOCK(in6p);
1472                                 in6p->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1473                                 INP_WUNLOCK(in6p);
1474                                 error = 0;
1475 #else
1476                                 error = EOPNOTSUPP;
1477 #endif
1478                                 break;
1479                         default:
1480                                 break;
1481                         }
1482                 }
1483         } else {                /* level == IPPROTO_IPV6 */
1484                 switch (op) {
1485
1486                 case SOPT_SET:
1487                         switch (optname) {
1488                         case IPV6_2292PKTOPTIONS:
1489 #ifdef IPV6_PKTOPTIONS
1490                         case IPV6_PKTOPTIONS:
1491 #endif
1492                         {
1493                                 struct mbuf *m;
1494
1495                                 if (optlen > IPV6_PKTOPTIONS_MBUF_LIMIT) {
1496                                         printf("ip6_ctloutput: mbuf limit hit\n");
1497                                         error = ENOBUFS;
1498                                         break;
1499                                 }
1500
1501                                 error = soopt_getm(sopt, &m); /* XXX */
1502                                 if (error != 0)
1503                                         break;
1504                                 error = soopt_mcopyin(sopt, m); /* XXX */
1505                                 if (error != 0)
1506                                         break;
1507                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1508                                                     m, so, sopt);
1509                                 m_freem(m); /* XXX */
1510                                 break;
1511                         }
1512
1513                         /*
1514                          * Use of some Hop-by-Hop options or some
1515                          * Destination options, might require special
1516                          * privilege.  That is, normal applications
1517                          * (without special privilege) might be forbidden
1518                          * from setting certain options in outgoing packets,
1519                          * and might never see certain options in received
1520                          * packets. [RFC 2292 Section 6]
1521                          * KAME specific note:
1522                          *  KAME prevents non-privileged users from sending or
1523                          *  receiving ANY hbh/dst options in order to avoid
1524                          *  overhead of parsing options in the kernel.
1525                          */
1526                         case IPV6_RECVHOPOPTS:
1527                         case IPV6_RECVDSTOPTS:
1528                         case IPV6_RECVRTHDRDSTOPTS:
1529                                 if (td != NULL) {
1530                                         error = priv_check(td,
1531                                             PRIV_NETINET_SETHDROPTS);
1532                                         if (error)
1533                                                 break;
1534                                 }
1535                                 /* FALLTHROUGH */
1536                         case IPV6_UNICAST_HOPS:
1537                         case IPV6_HOPLIMIT:
1538
1539                         case IPV6_RECVPKTINFO:
1540                         case IPV6_RECVHOPLIMIT:
1541                         case IPV6_RECVRTHDR:
1542                         case IPV6_RECVPATHMTU:
1543                         case IPV6_RECVTCLASS:
1544                         case IPV6_RECVFLOWID:
1545 #ifdef  RSS
1546                         case IPV6_RECVRSSBUCKETID:
1547 #endif
1548                         case IPV6_V6ONLY:
1549                         case IPV6_AUTOFLOWLABEL:
1550                         case IPV6_ORIGDSTADDR:
1551                         case IPV6_BINDANY:
1552                         case IPV6_BINDMULTI:
1553 #ifdef  RSS
1554                         case IPV6_RSS_LISTEN_BUCKET:
1555 #endif
1556                                 if (optname == IPV6_BINDANY && td != NULL) {
1557                                         error = priv_check(td,
1558                                             PRIV_NETINET_BINDANY);
1559                                         if (error)
1560                                                 break;
1561                                 }
1562
1563                                 if (optlen != sizeof(int)) {
1564                                         error = EINVAL;
1565                                         break;
1566                                 }
1567                                 error = sooptcopyin(sopt, &optval,
1568                                         sizeof optval, sizeof optval);
1569                                 if (error)
1570                                         break;
1571                                 switch (optname) {
1572
1573                                 case IPV6_UNICAST_HOPS:
1574                                         if (optval < -1 || optval >= 256)
1575                                                 error = EINVAL;
1576                                         else {
1577                                                 /* -1 = kernel default */
1578                                                 in6p->in6p_hops = optval;
1579                                                 if ((in6p->inp_vflag &
1580                                                      INP_IPV4) != 0)
1581                                                         in6p->inp_ip_ttl = optval;
1582                                         }
1583                                         break;
1584 #define OPTSET(bit) \
1585 do { \
1586         INP_WLOCK(in6p); \
1587         if (optval) \
1588                 in6p->inp_flags |= (bit); \
1589         else \
1590                 in6p->inp_flags &= ~(bit); \
1591         INP_WUNLOCK(in6p); \
1592 } while (/*CONSTCOND*/ 0)
1593 #define OPTSET2292(bit) \
1594 do { \
1595         INP_WLOCK(in6p); \
1596         in6p->inp_flags |= IN6P_RFC2292; \
1597         if (optval) \
1598                 in6p->inp_flags |= (bit); \
1599         else \
1600                 in6p->inp_flags &= ~(bit); \
1601         INP_WUNLOCK(in6p); \
1602 } while (/*CONSTCOND*/ 0)
1603 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1604
1605 #define OPTSET2(bit, val) do {                                          \
1606         INP_WLOCK(in6p);                                                \
1607         if (val)                                                        \
1608                 in6p->inp_flags2 |= bit;                                \
1609         else                                                            \
1610                 in6p->inp_flags2 &= ~bit;                               \
1611         INP_WUNLOCK(in6p);                                              \
1612 } while (0)
1613 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1614
1615                                 case IPV6_RECVPKTINFO:
1616                                         /* cannot mix with RFC2292 */
1617                                         if (OPTBIT(IN6P_RFC2292)) {
1618                                                 error = EINVAL;
1619                                                 break;
1620                                         }
1621                                         OPTSET(IN6P_PKTINFO);
1622                                         break;
1623
1624                                 case IPV6_HOPLIMIT:
1625                                 {
1626                                         struct ip6_pktopts **optp;
1627
1628                                         /* cannot mix with RFC2292 */
1629                                         if (OPTBIT(IN6P_RFC2292)) {
1630                                                 error = EINVAL;
1631                                                 break;
1632                                         }
1633                                         optp = &in6p->in6p_outputopts;
1634                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1635                                             (u_char *)&optval, sizeof(optval),
1636                                             optp, (td != NULL) ? td->td_ucred :
1637                                             NULL, uproto);
1638                                         break;
1639                                 }
1640
1641                                 case IPV6_RECVHOPLIMIT:
1642                                         /* cannot mix with RFC2292 */
1643                                         if (OPTBIT(IN6P_RFC2292)) {
1644                                                 error = EINVAL;
1645                                                 break;
1646                                         }
1647                                         OPTSET(IN6P_HOPLIMIT);
1648                                         break;
1649
1650                                 case IPV6_RECVHOPOPTS:
1651                                         /* cannot mix with RFC2292 */
1652                                         if (OPTBIT(IN6P_RFC2292)) {
1653                                                 error = EINVAL;
1654                                                 break;
1655                                         }
1656                                         OPTSET(IN6P_HOPOPTS);
1657                                         break;
1658
1659                                 case IPV6_RECVDSTOPTS:
1660                                         /* cannot mix with RFC2292 */
1661                                         if (OPTBIT(IN6P_RFC2292)) {
1662                                                 error = EINVAL;
1663                                                 break;
1664                                         }
1665                                         OPTSET(IN6P_DSTOPTS);
1666                                         break;
1667
1668                                 case IPV6_RECVRTHDRDSTOPTS:
1669                                         /* cannot mix with RFC2292 */
1670                                         if (OPTBIT(IN6P_RFC2292)) {
1671                                                 error = EINVAL;
1672                                                 break;
1673                                         }
1674                                         OPTSET(IN6P_RTHDRDSTOPTS);
1675                                         break;
1676
1677                                 case IPV6_RECVRTHDR:
1678                                         /* cannot mix with RFC2292 */
1679                                         if (OPTBIT(IN6P_RFC2292)) {
1680                                                 error = EINVAL;
1681                                                 break;
1682                                         }
1683                                         OPTSET(IN6P_RTHDR);
1684                                         break;
1685
1686                                 case IPV6_RECVPATHMTU:
1687                                         /*
1688                                          * We ignore this option for TCP
1689                                          * sockets.
1690                                          * (RFC3542 leaves this case
1691                                          * unspecified.)
1692                                          */
1693                                         if (uproto != IPPROTO_TCP)
1694                                                 OPTSET(IN6P_MTU);
1695                                         break;
1696
1697                                 case IPV6_RECVFLOWID:
1698                                         OPTSET2(INP_RECVFLOWID, optval);
1699                                         break;
1700
1701 #ifdef  RSS
1702                                 case IPV6_RECVRSSBUCKETID:
1703                                         OPTSET2(INP_RECVRSSBUCKETID, optval);
1704                                         break;
1705 #endif
1706
1707                                 case IPV6_V6ONLY:
1708                                         /*
1709                                          * make setsockopt(IPV6_V6ONLY)
1710                                          * available only prior to bind(2).
1711                                          * see ipng mailing list, Jun 22 2001.
1712                                          */
1713                                         if (in6p->inp_lport ||
1714                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1715                                                 error = EINVAL;
1716                                                 break;
1717                                         }
1718                                         OPTSET(IN6P_IPV6_V6ONLY);
1719                                         if (optval)
1720                                                 in6p->inp_vflag &= ~INP_IPV4;
1721                                         else
1722                                                 in6p->inp_vflag |= INP_IPV4;
1723                                         break;
1724                                 case IPV6_RECVTCLASS:
1725                                         /* cannot mix with RFC2292 XXX */
1726                                         if (OPTBIT(IN6P_RFC2292)) {
1727                                                 error = EINVAL;
1728                                                 break;
1729                                         }
1730                                         OPTSET(IN6P_TCLASS);
1731                                         break;
1732                                 case IPV6_AUTOFLOWLABEL:
1733                                         OPTSET(IN6P_AUTOFLOWLABEL);
1734                                         break;
1735
1736                                 case IPV6_ORIGDSTADDR:
1737                                         OPTSET2(INP_ORIGDSTADDR, optval);
1738                                         break;
1739                                 case IPV6_BINDANY:
1740                                         OPTSET(INP_BINDANY);
1741                                         break;
1742
1743                                 case IPV6_BINDMULTI:
1744                                         OPTSET2(INP_BINDMULTI, optval);
1745                                         break;
1746 #ifdef  RSS
1747                                 case IPV6_RSS_LISTEN_BUCKET:
1748                                         if ((optval >= 0) &&
1749                                             (optval < rss_getnumbuckets())) {
1750                                                 in6p->inp_rss_listen_bucket = optval;
1751                                                 OPTSET2(INP_RSS_BUCKET_SET, 1);
1752                                         } else {
1753                                                 error = EINVAL;
1754                                         }
1755                                         break;
1756 #endif
1757                                 }
1758                                 break;
1759
1760                         case IPV6_TCLASS:
1761                         case IPV6_DONTFRAG:
1762                         case IPV6_USE_MIN_MTU:
1763                         case IPV6_PREFER_TEMPADDR:
1764                                 if (optlen != sizeof(optval)) {
1765                                         error = EINVAL;
1766                                         break;
1767                                 }
1768                                 error = sooptcopyin(sopt, &optval,
1769                                         sizeof optval, sizeof optval);
1770                                 if (error)
1771                                         break;
1772                                 {
1773                                         struct ip6_pktopts **optp;
1774                                         optp = &in6p->in6p_outputopts;
1775                                         error = ip6_pcbopt(optname,
1776                                             (u_char *)&optval, sizeof(optval),
1777                                             optp, (td != NULL) ? td->td_ucred :
1778                                             NULL, uproto);
1779                                         break;
1780                                 }
1781
1782                         case IPV6_2292PKTINFO:
1783                         case IPV6_2292HOPLIMIT:
1784                         case IPV6_2292HOPOPTS:
1785                         case IPV6_2292DSTOPTS:
1786                         case IPV6_2292RTHDR:
1787                                 /* RFC 2292 */
1788                                 if (optlen != sizeof(int)) {
1789                                         error = EINVAL;
1790                                         break;
1791                                 }
1792                                 error = sooptcopyin(sopt, &optval,
1793                                         sizeof optval, sizeof optval);
1794                                 if (error)
1795                                         break;
1796                                 switch (optname) {
1797                                 case IPV6_2292PKTINFO:
1798                                         OPTSET2292(IN6P_PKTINFO);
1799                                         break;
1800                                 case IPV6_2292HOPLIMIT:
1801                                         OPTSET2292(IN6P_HOPLIMIT);
1802                                         break;
1803                                 case IPV6_2292HOPOPTS:
1804                                         /*
1805                                          * Check super-user privilege.
1806                                          * See comments for IPV6_RECVHOPOPTS.
1807                                          */
1808                                         if (td != NULL) {
1809                                                 error = priv_check(td,
1810                                                     PRIV_NETINET_SETHDROPTS);
1811                                                 if (error)
1812                                                         return (error);
1813                                         }
1814                                         OPTSET2292(IN6P_HOPOPTS);
1815                                         break;
1816                                 case IPV6_2292DSTOPTS:
1817                                         if (td != NULL) {
1818                                                 error = priv_check(td,
1819                                                     PRIV_NETINET_SETHDROPTS);
1820                                                 if (error)
1821                                                         return (error);
1822                                         }
1823                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1824                                         break;
1825                                 case IPV6_2292RTHDR:
1826                                         OPTSET2292(IN6P_RTHDR);
1827                                         break;
1828                                 }
1829                                 break;
1830                         case IPV6_PKTINFO:
1831                         case IPV6_HOPOPTS:
1832                         case IPV6_RTHDR:
1833                         case IPV6_DSTOPTS:
1834                         case IPV6_RTHDRDSTOPTS:
1835                         case IPV6_NEXTHOP:
1836                         {
1837                                 /* new advanced API (RFC3542) */
1838                                 u_char *optbuf;
1839                                 u_char optbuf_storage[MCLBYTES];
1840                                 int optlen;
1841                                 struct ip6_pktopts **optp;
1842
1843                                 /* cannot mix with RFC2292 */
1844                                 if (OPTBIT(IN6P_RFC2292)) {
1845                                         error = EINVAL;
1846                                         break;
1847                                 }
1848
1849                                 /*
1850                                  * We only ensure valsize is not too large
1851                                  * here.  Further validation will be done
1852                                  * later.
1853                                  */
1854                                 error = sooptcopyin(sopt, optbuf_storage,
1855                                     sizeof(optbuf_storage), 0);
1856                                 if (error)
1857                                         break;
1858                                 optlen = sopt->sopt_valsize;
1859                                 optbuf = optbuf_storage;
1860                                 optp = &in6p->in6p_outputopts;
1861                                 error = ip6_pcbopt(optname, optbuf, optlen,
1862                                     optp, (td != NULL) ? td->td_ucred : NULL,
1863                                     uproto);
1864                                 break;
1865                         }
1866 #undef OPTSET
1867
1868                         case IPV6_MULTICAST_IF:
1869                         case IPV6_MULTICAST_HOPS:
1870                         case IPV6_MULTICAST_LOOP:
1871                         case IPV6_JOIN_GROUP:
1872                         case IPV6_LEAVE_GROUP:
1873                         case IPV6_MSFILTER:
1874                         case MCAST_BLOCK_SOURCE:
1875                         case MCAST_UNBLOCK_SOURCE:
1876                         case MCAST_JOIN_GROUP:
1877                         case MCAST_LEAVE_GROUP:
1878                         case MCAST_JOIN_SOURCE_GROUP:
1879                         case MCAST_LEAVE_SOURCE_GROUP:
1880                                 error = ip6_setmoptions(in6p, sopt);
1881                                 break;
1882
1883                         case IPV6_PORTRANGE:
1884                                 error = sooptcopyin(sopt, &optval,
1885                                     sizeof optval, sizeof optval);
1886                                 if (error)
1887                                         break;
1888
1889                                 INP_WLOCK(in6p);
1890                                 switch (optval) {
1891                                 case IPV6_PORTRANGE_DEFAULT:
1892                                         in6p->inp_flags &= ~(INP_LOWPORT);
1893                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1894                                         break;
1895
1896                                 case IPV6_PORTRANGE_HIGH:
1897                                         in6p->inp_flags &= ~(INP_LOWPORT);
1898                                         in6p->inp_flags |= INP_HIGHPORT;
1899                                         break;
1900
1901                                 case IPV6_PORTRANGE_LOW:
1902                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1903                                         in6p->inp_flags |= INP_LOWPORT;
1904                                         break;
1905
1906                                 default:
1907                                         error = EINVAL;
1908                                         break;
1909                                 }
1910                                 INP_WUNLOCK(in6p);
1911                                 break;
1912
1913 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1914                         case IPV6_IPSEC_POLICY:
1915                                 if (IPSEC_ENABLED(ipv6)) {
1916                                         error = IPSEC_PCBCTL(ipv6, in6p, sopt);
1917                                         break;
1918                                 }
1919                                 /* FALLTHROUGH */
1920 #endif /* IPSEC */
1921
1922                         default:
1923                                 error = ENOPROTOOPT;
1924                                 break;
1925                         }
1926                         break;
1927
1928                 case SOPT_GET:
1929                         switch (optname) {
1930
1931                         case IPV6_2292PKTOPTIONS:
1932 #ifdef IPV6_PKTOPTIONS
1933                         case IPV6_PKTOPTIONS:
1934 #endif
1935                                 /*
1936                                  * RFC3542 (effectively) deprecated the
1937                                  * semantics of the 2292-style pktoptions.
1938                                  * Since it was not reliable in nature (i.e.,
1939                                  * applications had to expect the lack of some
1940                                  * information after all), it would make sense
1941                                  * to simplify this part by always returning
1942                                  * empty data.
1943                                  */
1944                                 sopt->sopt_valsize = 0;
1945                                 break;
1946
1947                         case IPV6_RECVHOPOPTS:
1948                         case IPV6_RECVDSTOPTS:
1949                         case IPV6_RECVRTHDRDSTOPTS:
1950                         case IPV6_UNICAST_HOPS:
1951                         case IPV6_RECVPKTINFO:
1952                         case IPV6_RECVHOPLIMIT:
1953                         case IPV6_RECVRTHDR:
1954                         case IPV6_RECVPATHMTU:
1955
1956                         case IPV6_V6ONLY:
1957                         case IPV6_PORTRANGE:
1958                         case IPV6_RECVTCLASS:
1959                         case IPV6_AUTOFLOWLABEL:
1960                         case IPV6_BINDANY:
1961                         case IPV6_FLOWID:
1962                         case IPV6_FLOWTYPE:
1963                         case IPV6_RECVFLOWID:
1964 #ifdef  RSS
1965                         case IPV6_RSSBUCKETID:
1966                         case IPV6_RECVRSSBUCKETID:
1967 #endif
1968                         case IPV6_BINDMULTI:
1969                                 switch (optname) {
1970
1971                                 case IPV6_RECVHOPOPTS:
1972                                         optval = OPTBIT(IN6P_HOPOPTS);
1973                                         break;
1974
1975                                 case IPV6_RECVDSTOPTS:
1976                                         optval = OPTBIT(IN6P_DSTOPTS);
1977                                         break;
1978
1979                                 case IPV6_RECVRTHDRDSTOPTS:
1980                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1981                                         break;
1982
1983                                 case IPV6_UNICAST_HOPS:
1984                                         optval = in6p->in6p_hops;
1985                                         break;
1986
1987                                 case IPV6_RECVPKTINFO:
1988                                         optval = OPTBIT(IN6P_PKTINFO);
1989                                         break;
1990
1991                                 case IPV6_RECVHOPLIMIT:
1992                                         optval = OPTBIT(IN6P_HOPLIMIT);
1993                                         break;
1994
1995                                 case IPV6_RECVRTHDR:
1996                                         optval = OPTBIT(IN6P_RTHDR);
1997                                         break;
1998
1999                                 case IPV6_RECVPATHMTU:
2000                                         optval = OPTBIT(IN6P_MTU);
2001                                         break;
2002
2003                                 case IPV6_V6ONLY:
2004                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
2005                                         break;
2006
2007                                 case IPV6_PORTRANGE:
2008                                     {
2009                                         int flags;
2010                                         flags = in6p->inp_flags;
2011                                         if (flags & INP_HIGHPORT)
2012                                                 optval = IPV6_PORTRANGE_HIGH;
2013                                         else if (flags & INP_LOWPORT)
2014                                                 optval = IPV6_PORTRANGE_LOW;
2015                                         else
2016                                                 optval = 0;
2017                                         break;
2018                                     }
2019                                 case IPV6_RECVTCLASS:
2020                                         optval = OPTBIT(IN6P_TCLASS);
2021                                         break;
2022
2023                                 case IPV6_AUTOFLOWLABEL:
2024                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2025                                         break;
2026
2027                                 case IPV6_ORIGDSTADDR:
2028                                         optval = OPTBIT2(INP_ORIGDSTADDR);
2029                                         break;
2030
2031                                 case IPV6_BINDANY:
2032                                         optval = OPTBIT(INP_BINDANY);
2033                                         break;
2034
2035                                 case IPV6_FLOWID:
2036                                         optval = in6p->inp_flowid;
2037                                         break;
2038
2039                                 case IPV6_FLOWTYPE:
2040                                         optval = in6p->inp_flowtype;
2041                                         break;
2042
2043                                 case IPV6_RECVFLOWID:
2044                                         optval = OPTBIT2(INP_RECVFLOWID);
2045                                         break;
2046 #ifdef  RSS
2047                                 case IPV6_RSSBUCKETID:
2048                                         retval =
2049                                             rss_hash2bucket(in6p->inp_flowid,
2050                                             in6p->inp_flowtype,
2051                                             &rss_bucket);
2052                                         if (retval == 0)
2053                                                 optval = rss_bucket;
2054                                         else
2055                                                 error = EINVAL;
2056                                         break;
2057
2058                                 case IPV6_RECVRSSBUCKETID:
2059                                         optval = OPTBIT2(INP_RECVRSSBUCKETID);
2060                                         break;
2061 #endif
2062
2063                                 case IPV6_BINDMULTI:
2064                                         optval = OPTBIT2(INP_BINDMULTI);
2065                                         break;
2066
2067                                 }
2068                                 if (error)
2069                                         break;
2070                                 error = sooptcopyout(sopt, &optval,
2071                                         sizeof optval);
2072                                 break;
2073
2074                         case IPV6_PATHMTU:
2075                         {
2076                                 u_long pmtu = 0;
2077                                 struct ip6_mtuinfo mtuinfo;
2078
2079                                 if (!(so->so_state & SS_ISCONNECTED))
2080                                         return (ENOTCONN);
2081                                 /*
2082                                  * XXX: we dot not consider the case of source
2083                                  * routing, or optional information to specify
2084                                  * the outgoing interface.
2085                                  */
2086                                 error = ip6_getpmtu_ctl(so->so_fibnum,
2087                                     &in6p->in6p_faddr, &pmtu);
2088                                 if (error)
2089                                         break;
2090                                 if (pmtu > IPV6_MAXPACKET)
2091                                         pmtu = IPV6_MAXPACKET;
2092
2093                                 bzero(&mtuinfo, sizeof(mtuinfo));
2094                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2095                                 optdata = (void *)&mtuinfo;
2096                                 optdatalen = sizeof(mtuinfo);
2097                                 error = sooptcopyout(sopt, optdata,
2098                                     optdatalen);
2099                                 break;
2100                         }
2101
2102                         case IPV6_2292PKTINFO:
2103                         case IPV6_2292HOPLIMIT:
2104                         case IPV6_2292HOPOPTS:
2105                         case IPV6_2292RTHDR:
2106                         case IPV6_2292DSTOPTS:
2107                                 switch (optname) {
2108                                 case IPV6_2292PKTINFO:
2109                                         optval = OPTBIT(IN6P_PKTINFO);
2110                                         break;
2111                                 case IPV6_2292HOPLIMIT:
2112                                         optval = OPTBIT(IN6P_HOPLIMIT);
2113                                         break;
2114                                 case IPV6_2292HOPOPTS:
2115                                         optval = OPTBIT(IN6P_HOPOPTS);
2116                                         break;
2117                                 case IPV6_2292RTHDR:
2118                                         optval = OPTBIT(IN6P_RTHDR);
2119                                         break;
2120                                 case IPV6_2292DSTOPTS:
2121                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2122                                         break;
2123                                 }
2124                                 error = sooptcopyout(sopt, &optval,
2125                                     sizeof optval);
2126                                 break;
2127                         case IPV6_PKTINFO:
2128                         case IPV6_HOPOPTS:
2129                         case IPV6_RTHDR:
2130                         case IPV6_DSTOPTS:
2131                         case IPV6_RTHDRDSTOPTS:
2132                         case IPV6_NEXTHOP:
2133                         case IPV6_TCLASS:
2134                         case IPV6_DONTFRAG:
2135                         case IPV6_USE_MIN_MTU:
2136                         case IPV6_PREFER_TEMPADDR:
2137                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
2138                                     optname, sopt);
2139                                 break;
2140
2141                         case IPV6_MULTICAST_IF:
2142                         case IPV6_MULTICAST_HOPS:
2143                         case IPV6_MULTICAST_LOOP:
2144                         case IPV6_MSFILTER:
2145                                 error = ip6_getmoptions(in6p, sopt);
2146                                 break;
2147
2148 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2149                         case IPV6_IPSEC_POLICY:
2150                                 if (IPSEC_ENABLED(ipv6)) {
2151                                         error = IPSEC_PCBCTL(ipv6, in6p, sopt);
2152                                         break;
2153                                 }
2154                                 /* FALLTHROUGH */
2155 #endif /* IPSEC */
2156                         default:
2157                                 error = ENOPROTOOPT;
2158                                 break;
2159                         }
2160                         break;
2161                 }
2162         }
2163         return (error);
2164 }
2165
2166 int
2167 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2168 {
2169         int error = 0, optval, optlen;
2170         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2171         struct inpcb *in6p = sotoinpcb(so);
2172         int level, op, optname;
2173
2174         level = sopt->sopt_level;
2175         op = sopt->sopt_dir;
2176         optname = sopt->sopt_name;
2177         optlen = sopt->sopt_valsize;
2178
2179         if (level != IPPROTO_IPV6) {
2180                 return (EINVAL);
2181         }
2182
2183         switch (optname) {
2184         case IPV6_CHECKSUM:
2185                 /*
2186                  * For ICMPv6 sockets, no modification allowed for checksum
2187                  * offset, permit "no change" values to help existing apps.
2188                  *
2189                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2190                  * for an ICMPv6 socket will fail."
2191                  * The current behavior does not meet RFC3542.
2192                  */
2193                 switch (op) {
2194                 case SOPT_SET:
2195                         if (optlen != sizeof(int)) {
2196                                 error = EINVAL;
2197                                 break;
2198                         }
2199                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2200                                             sizeof(optval));
2201                         if (error)
2202                                 break;
2203                         if ((optval % 2) != 0) {
2204                                 /* the API assumes even offset values */
2205                                 error = EINVAL;
2206                         } else if (so->so_proto->pr_protocol ==
2207                             IPPROTO_ICMPV6) {
2208                                 if (optval != icmp6off)
2209                                         error = EINVAL;
2210                         } else
2211                                 in6p->in6p_cksum = optval;
2212                         break;
2213
2214                 case SOPT_GET:
2215                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2216                                 optval = icmp6off;
2217                         else
2218                                 optval = in6p->in6p_cksum;
2219
2220                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2221                         break;
2222
2223                 default:
2224                         error = EINVAL;
2225                         break;
2226                 }
2227                 break;
2228
2229         default:
2230                 error = ENOPROTOOPT;
2231                 break;
2232         }
2233
2234         return (error);
2235 }
2236
2237 /*
2238  * Set up IP6 options in pcb for insertion in output packets or
2239  * specifying behavior of outgoing packets.
2240  */
2241 static int
2242 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2243     struct socket *so, struct sockopt *sopt)
2244 {
2245         struct ip6_pktopts *opt = *pktopt;
2246         int error = 0;
2247         struct thread *td = sopt->sopt_td;
2248
2249         /* turn off any old options. */
2250         if (opt) {
2251 #ifdef DIAGNOSTIC
2252                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2253                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2254                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2255                         printf("ip6_pcbopts: all specified options are cleared.\n");
2256 #endif
2257                 ip6_clearpktopts(opt, -1);
2258         } else
2259                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2260         *pktopt = NULL;
2261
2262         if (!m || m->m_len == 0) {
2263                 /*
2264                  * Only turning off any previous options, regardless of
2265                  * whether the opt is just created or given.
2266                  */
2267                 free(opt, M_IP6OPT);
2268                 return (0);
2269         }
2270
2271         /*  set options specified by user. */
2272         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2273             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2274                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2275                 free(opt, M_IP6OPT);
2276                 return (error);
2277         }
2278         *pktopt = opt;
2279         return (0);
2280 }
2281
2282 /*
2283  * initialize ip6_pktopts.  beware that there are non-zero default values in
2284  * the struct.
2285  */
2286 void
2287 ip6_initpktopts(struct ip6_pktopts *opt)
2288 {
2289
2290         bzero(opt, sizeof(*opt));
2291         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2292         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2293         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2294         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2295 }
2296
2297 static int
2298 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2299     struct ucred *cred, int uproto)
2300 {
2301         struct ip6_pktopts *opt;
2302
2303         if (*pktopt == NULL) {
2304                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2305                     M_WAITOK);
2306                 ip6_initpktopts(*pktopt);
2307         }
2308         opt = *pktopt;
2309
2310         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2311 }
2312
2313 static int
2314 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2315 {
2316         void *optdata = NULL;
2317         int optdatalen = 0;
2318         struct ip6_ext *ip6e;
2319         int error = 0;
2320         struct in6_pktinfo null_pktinfo;
2321         int deftclass = 0, on;
2322         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2323         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2324
2325         switch (optname) {
2326         case IPV6_PKTINFO:
2327                 optdata = (void *)&null_pktinfo;
2328                 if (pktopt && pktopt->ip6po_pktinfo) {
2329                         bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2330                             sizeof(null_pktinfo));
2331                         in6_clearscope(&null_pktinfo.ipi6_addr);
2332                 } else {
2333                         /* XXX: we don't have to do this every time... */
2334                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2335                 }
2336                 optdatalen = sizeof(struct in6_pktinfo);
2337                 break;
2338         case IPV6_TCLASS:
2339                 if (pktopt && pktopt->ip6po_tclass >= 0)
2340                         optdata = (void *)&pktopt->ip6po_tclass;
2341                 else
2342                         optdata = (void *)&deftclass;
2343                 optdatalen = sizeof(int);
2344                 break;
2345         case IPV6_HOPOPTS:
2346                 if (pktopt && pktopt->ip6po_hbh) {
2347                         optdata = (void *)pktopt->ip6po_hbh;
2348                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2349                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2350                 }
2351                 break;
2352         case IPV6_RTHDR:
2353                 if (pktopt && pktopt->ip6po_rthdr) {
2354                         optdata = (void *)pktopt->ip6po_rthdr;
2355                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2356                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2357                 }
2358                 break;
2359         case IPV6_RTHDRDSTOPTS:
2360                 if (pktopt && pktopt->ip6po_dest1) {
2361                         optdata = (void *)pktopt->ip6po_dest1;
2362                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2363                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2364                 }
2365                 break;
2366         case IPV6_DSTOPTS:
2367                 if (pktopt && pktopt->ip6po_dest2) {
2368                         optdata = (void *)pktopt->ip6po_dest2;
2369                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2370                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2371                 }
2372                 break;
2373         case IPV6_NEXTHOP:
2374                 if (pktopt && pktopt->ip6po_nexthop) {
2375                         optdata = (void *)pktopt->ip6po_nexthop;
2376                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2377                 }
2378                 break;
2379         case IPV6_USE_MIN_MTU:
2380                 if (pktopt)
2381                         optdata = (void *)&pktopt->ip6po_minmtu;
2382                 else
2383                         optdata = (void *)&defminmtu;
2384                 optdatalen = sizeof(int);
2385                 break;
2386         case IPV6_DONTFRAG:
2387                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2388                         on = 1;
2389                 else
2390                         on = 0;
2391                 optdata = (void *)&on;
2392                 optdatalen = sizeof(on);
2393                 break;
2394         case IPV6_PREFER_TEMPADDR:
2395                 if (pktopt)
2396                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2397                 else
2398                         optdata = (void *)&defpreftemp;
2399                 optdatalen = sizeof(int);
2400                 break;
2401         default:                /* should not happen */
2402 #ifdef DIAGNOSTIC
2403                 panic("ip6_getpcbopt: unexpected option\n");
2404 #endif
2405                 return (ENOPROTOOPT);
2406         }
2407
2408         error = sooptcopyout(sopt, optdata, optdatalen);
2409
2410         return (error);
2411 }
2412
2413 void
2414 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2415 {
2416         if (pktopt == NULL)
2417                 return;
2418
2419         if (optname == -1 || optname == IPV6_PKTINFO) {
2420                 if (pktopt->ip6po_pktinfo)
2421                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2422                 pktopt->ip6po_pktinfo = NULL;
2423         }
2424         if (optname == -1 || optname == IPV6_HOPLIMIT)
2425                 pktopt->ip6po_hlim = -1;
2426         if (optname == -1 || optname == IPV6_TCLASS)
2427                 pktopt->ip6po_tclass = -1;
2428         if (optname == -1 || optname == IPV6_NEXTHOP) {
2429                 if (pktopt->ip6po_nextroute.ro_rt) {
2430                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2431                         pktopt->ip6po_nextroute.ro_rt = NULL;
2432                 }
2433                 if (pktopt->ip6po_nexthop)
2434                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2435                 pktopt->ip6po_nexthop = NULL;
2436         }
2437         if (optname == -1 || optname == IPV6_HOPOPTS) {
2438                 if (pktopt->ip6po_hbh)
2439                         free(pktopt->ip6po_hbh, M_IP6OPT);
2440                 pktopt->ip6po_hbh = NULL;
2441         }
2442         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2443                 if (pktopt->ip6po_dest1)
2444                         free(pktopt->ip6po_dest1, M_IP6OPT);
2445                 pktopt->ip6po_dest1 = NULL;
2446         }
2447         if (optname == -1 || optname == IPV6_RTHDR) {
2448                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2449                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2450                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2451                 if (pktopt->ip6po_route.ro_rt) {
2452                         RTFREE(pktopt->ip6po_route.ro_rt);
2453                         pktopt->ip6po_route.ro_rt = NULL;
2454                 }
2455         }
2456         if (optname == -1 || optname == IPV6_DSTOPTS) {
2457                 if (pktopt->ip6po_dest2)
2458                         free(pktopt->ip6po_dest2, M_IP6OPT);
2459                 pktopt->ip6po_dest2 = NULL;
2460         }
2461 }
2462
2463 #define PKTOPT_EXTHDRCPY(type) \
2464 do {\
2465         if (src->type) {\
2466                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2467                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2468                 if (dst->type == NULL)\
2469                         goto bad;\
2470                 bcopy(src->type, dst->type, hlen);\
2471         }\
2472 } while (/*CONSTCOND*/ 0)
2473
2474 static int
2475 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2476 {
2477         if (dst == NULL || src == NULL)  {
2478                 printf("ip6_clearpktopts: invalid argument\n");
2479                 return (EINVAL);
2480         }
2481
2482         dst->ip6po_hlim = src->ip6po_hlim;
2483         dst->ip6po_tclass = src->ip6po_tclass;
2484         dst->ip6po_flags = src->ip6po_flags;
2485         dst->ip6po_minmtu = src->ip6po_minmtu;
2486         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2487         if (src->ip6po_pktinfo) {
2488                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2489                     M_IP6OPT, canwait);
2490                 if (dst->ip6po_pktinfo == NULL)
2491                         goto bad;
2492                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2493         }
2494         if (src->ip6po_nexthop) {
2495                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2496                     M_IP6OPT, canwait);
2497                 if (dst->ip6po_nexthop == NULL)
2498                         goto bad;
2499                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2500                     src->ip6po_nexthop->sa_len);
2501         }
2502         PKTOPT_EXTHDRCPY(ip6po_hbh);
2503         PKTOPT_EXTHDRCPY(ip6po_dest1);
2504         PKTOPT_EXTHDRCPY(ip6po_dest2);
2505         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2506         return (0);
2507
2508   bad:
2509         ip6_clearpktopts(dst, -1);
2510         return (ENOBUFS);
2511 }
2512 #undef PKTOPT_EXTHDRCPY
2513
2514 struct ip6_pktopts *
2515 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2516 {
2517         int error;
2518         struct ip6_pktopts *dst;
2519
2520         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2521         if (dst == NULL)
2522                 return (NULL);
2523         ip6_initpktopts(dst);
2524
2525         if ((error = copypktopts(dst, src, canwait)) != 0) {
2526                 free(dst, M_IP6OPT);
2527                 return (NULL);
2528         }
2529
2530         return (dst);
2531 }
2532
2533 void
2534 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2535 {
2536         if (pktopt == NULL)
2537                 return;
2538
2539         ip6_clearpktopts(pktopt, -1);
2540
2541         free(pktopt, M_IP6OPT);
2542 }
2543
2544 /*
2545  * Set IPv6 outgoing packet options based on advanced API.
2546  */
2547 int
2548 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2549     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2550 {
2551         struct cmsghdr *cm = NULL;
2552
2553         if (control == NULL || opt == NULL)
2554                 return (EINVAL);
2555
2556         ip6_initpktopts(opt);
2557         if (stickyopt) {
2558                 int error;
2559
2560                 /*
2561                  * If stickyopt is provided, make a local copy of the options
2562                  * for this particular packet, then override them by ancillary
2563                  * objects.
2564                  * XXX: copypktopts() does not copy the cached route to a next
2565                  * hop (if any).  This is not very good in terms of efficiency,
2566                  * but we can allow this since this option should be rarely
2567                  * used.
2568                  */
2569                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2570                         return (error);
2571         }
2572
2573         /*
2574          * XXX: Currently, we assume all the optional information is stored
2575          * in a single mbuf.
2576          */
2577         if (control->m_next)
2578                 return (EINVAL);
2579
2580         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2581             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2582                 int error;
2583
2584                 if (control->m_len < CMSG_LEN(0))
2585                         return (EINVAL);
2586
2587                 cm = mtod(control, struct cmsghdr *);
2588                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2589                         return (EINVAL);
2590                 if (cm->cmsg_level != IPPROTO_IPV6)
2591                         continue;
2592
2593                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2594                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2595                 if (error)
2596                         return (error);
2597         }
2598
2599         return (0);
2600 }
2601
2602 /*
2603  * Set a particular packet option, as a sticky option or an ancillary data
2604  * item.  "len" can be 0 only when it's a sticky option.
2605  * We have 4 cases of combination of "sticky" and "cmsg":
2606  * "sticky=0, cmsg=0": impossible
2607  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2608  * "sticky=1, cmsg=0": RFC3542 socket option
2609  * "sticky=1, cmsg=1": RFC2292 socket option
2610  */
2611 static int
2612 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2613     struct ucred *cred, int sticky, int cmsg, int uproto)
2614 {
2615         int minmtupolicy, preftemp;
2616         int error;
2617
2618         if (!sticky && !cmsg) {
2619 #ifdef DIAGNOSTIC
2620                 printf("ip6_setpktopt: impossible case\n");
2621 #endif
2622                 return (EINVAL);
2623         }
2624
2625         /*
2626          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2627          * not be specified in the context of RFC3542.  Conversely,
2628          * RFC3542 types should not be specified in the context of RFC2292.
2629          */
2630         if (!cmsg) {
2631                 switch (optname) {
2632                 case IPV6_2292PKTINFO:
2633                 case IPV6_2292HOPLIMIT:
2634                 case IPV6_2292NEXTHOP:
2635                 case IPV6_2292HOPOPTS:
2636                 case IPV6_2292DSTOPTS:
2637                 case IPV6_2292RTHDR:
2638                 case IPV6_2292PKTOPTIONS:
2639                         return (ENOPROTOOPT);
2640                 }
2641         }
2642         if (sticky && cmsg) {
2643                 switch (optname) {
2644                 case IPV6_PKTINFO:
2645                 case IPV6_HOPLIMIT:
2646                 case IPV6_NEXTHOP:
2647                 case IPV6_HOPOPTS:
2648                 case IPV6_DSTOPTS:
2649                 case IPV6_RTHDRDSTOPTS:
2650                 case IPV6_RTHDR:
2651                 case IPV6_USE_MIN_MTU:
2652                 case IPV6_DONTFRAG:
2653                 case IPV6_TCLASS:
2654                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2655                         return (ENOPROTOOPT);
2656                 }
2657         }
2658
2659         switch (optname) {
2660         case IPV6_2292PKTINFO:
2661         case IPV6_PKTINFO:
2662         {
2663                 struct ifnet *ifp = NULL;
2664                 struct in6_pktinfo *pktinfo;
2665
2666                 if (len != sizeof(struct in6_pktinfo))
2667                         return (EINVAL);
2668
2669                 pktinfo = (struct in6_pktinfo *)buf;
2670
2671                 /*
2672                  * An application can clear any sticky IPV6_PKTINFO option by
2673                  * doing a "regular" setsockopt with ipi6_addr being
2674                  * in6addr_any and ipi6_ifindex being zero.
2675                  * [RFC 3542, Section 6]
2676                  */
2677                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2678                     pktinfo->ipi6_ifindex == 0 &&
2679                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2680                         ip6_clearpktopts(opt, optname);
2681                         break;
2682                 }
2683
2684                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2685                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2686                         return (EINVAL);
2687                 }
2688                 if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2689                         return (EINVAL);
2690                 /* validate the interface index if specified. */
2691                 if (pktinfo->ipi6_ifindex > V_if_index)
2692                          return (ENXIO);
2693                 if (pktinfo->ipi6_ifindex) {
2694                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2695                         if (ifp == NULL)
2696                                 return (ENXIO);
2697                 }
2698                 if (ifp != NULL && (ifp->if_afdata[AF_INET6] == NULL ||
2699                     (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0))
2700                         return (ENETDOWN);
2701
2702                 if (ifp != NULL &&
2703                     !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2704                         struct in6_ifaddr *ia;
2705
2706                         in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2707                         ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2708                         if (ia == NULL)
2709                                 return (EADDRNOTAVAIL);
2710                         ifa_free(&ia->ia_ifa);
2711                 }
2712                 /*
2713                  * We store the address anyway, and let in6_selectsrc()
2714                  * validate the specified address.  This is because ipi6_addr
2715                  * may not have enough information about its scope zone, and
2716                  * we may need additional information (such as outgoing
2717                  * interface or the scope zone of a destination address) to
2718                  * disambiguate the scope.
2719                  * XXX: the delay of the validation may confuse the
2720                  * application when it is used as a sticky option.
2721                  */
2722                 if (opt->ip6po_pktinfo == NULL) {
2723                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2724                             M_IP6OPT, M_NOWAIT);
2725                         if (opt->ip6po_pktinfo == NULL)
2726                                 return (ENOBUFS);
2727                 }
2728                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2729                 break;
2730         }
2731
2732         case IPV6_2292HOPLIMIT:
2733         case IPV6_HOPLIMIT:
2734         {
2735                 int *hlimp;
2736
2737                 /*
2738                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2739                  * to simplify the ordering among hoplimit options.
2740                  */
2741                 if (optname == IPV6_HOPLIMIT && sticky)
2742                         return (ENOPROTOOPT);
2743
2744                 if (len != sizeof(int))
2745                         return (EINVAL);
2746                 hlimp = (int *)buf;
2747                 if (*hlimp < -1 || *hlimp > 255)
2748                         return (EINVAL);
2749
2750                 opt->ip6po_hlim = *hlimp;
2751                 break;
2752         }
2753
2754         case IPV6_TCLASS:
2755         {
2756                 int tclass;
2757
2758                 if (len != sizeof(int))
2759                         return (EINVAL);
2760                 tclass = *(int *)buf;
2761                 if (tclass < -1 || tclass > 255)
2762                         return (EINVAL);
2763
2764                 opt->ip6po_tclass = tclass;
2765                 break;
2766         }
2767
2768         case IPV6_2292NEXTHOP:
2769         case IPV6_NEXTHOP:
2770                 if (cred != NULL) {
2771                         error = priv_check_cred(cred,
2772                             PRIV_NETINET_SETHDROPTS, 0);
2773                         if (error)
2774                                 return (error);
2775                 }
2776
2777                 if (len == 0) { /* just remove the option */
2778                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2779                         break;
2780                 }
2781
2782                 /* check if cmsg_len is large enough for sa_len */
2783                 if (len < sizeof(struct sockaddr) || len < *buf)
2784                         return (EINVAL);
2785
2786                 switch (((struct sockaddr *)buf)->sa_family) {
2787                 case AF_INET6:
2788                 {
2789                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2790                         int error;
2791
2792                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2793                                 return (EINVAL);
2794
2795                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2796                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2797                                 return (EINVAL);
2798                         }
2799                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2800                             != 0) {
2801                                 return (error);
2802                         }
2803                         break;
2804                 }
2805                 case AF_LINK:   /* should eventually be supported */
2806                 default:
2807                         return (EAFNOSUPPORT);
2808                 }
2809
2810                 /* turn off the previous option, then set the new option. */
2811                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2812                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2813                 if (opt->ip6po_nexthop == NULL)
2814                         return (ENOBUFS);
2815                 bcopy(buf, opt->ip6po_nexthop, *buf);
2816                 break;
2817
2818         case IPV6_2292HOPOPTS:
2819         case IPV6_HOPOPTS:
2820         {
2821                 struct ip6_hbh *hbh;
2822                 int hbhlen;
2823
2824                 /*
2825                  * XXX: We don't allow a non-privileged user to set ANY HbH
2826                  * options, since per-option restriction has too much
2827                  * overhead.
2828                  */
2829                 if (cred != NULL) {
2830                         error = priv_check_cred(cred,
2831                             PRIV_NETINET_SETHDROPTS, 0);
2832                         if (error)
2833                                 return (error);
2834                 }
2835
2836                 if (len == 0) {
2837                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2838                         break;  /* just remove the option */
2839                 }
2840
2841                 /* message length validation */
2842                 if (len < sizeof(struct ip6_hbh))
2843                         return (EINVAL);
2844                 hbh = (struct ip6_hbh *)buf;
2845                 hbhlen = (hbh->ip6h_len + 1) << 3;
2846                 if (len != hbhlen)
2847                         return (EINVAL);
2848
2849                 /* turn off the previous option, then set the new option. */
2850                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2851                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2852                 if (opt->ip6po_hbh == NULL)
2853                         return (ENOBUFS);
2854                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2855
2856                 break;
2857         }
2858
2859         case IPV6_2292DSTOPTS:
2860         case IPV6_DSTOPTS:
2861         case IPV6_RTHDRDSTOPTS:
2862         {
2863                 struct ip6_dest *dest, **newdest = NULL;
2864                 int destlen;
2865
2866                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2867                         error = priv_check_cred(cred,
2868                             PRIV_NETINET_SETHDROPTS, 0);
2869                         if (error)
2870                                 return (error);
2871                 }
2872
2873                 if (len == 0) {
2874                         ip6_clearpktopts(opt, optname);
2875                         break;  /* just remove the option */
2876                 }
2877
2878                 /* message length validation */
2879                 if (len < sizeof(struct ip6_dest))
2880                         return (EINVAL);
2881                 dest = (struct ip6_dest *)buf;
2882                 destlen = (dest->ip6d_len + 1) << 3;
2883                 if (len != destlen)
2884                         return (EINVAL);
2885
2886                 /*
2887                  * Determine the position that the destination options header
2888                  * should be inserted; before or after the routing header.
2889                  */
2890                 switch (optname) {
2891                 case IPV6_2292DSTOPTS:
2892                         /*
2893                          * The old advacned API is ambiguous on this point.
2894                          * Our approach is to determine the position based
2895                          * according to the existence of a routing header.
2896                          * Note, however, that this depends on the order of the
2897                          * extension headers in the ancillary data; the 1st
2898                          * part of the destination options header must appear
2899                          * before the routing header in the ancillary data,
2900                          * too.
2901                          * RFC3542 solved the ambiguity by introducing
2902                          * separate ancillary data or option types.
2903                          */
2904                         if (opt->ip6po_rthdr == NULL)
2905                                 newdest = &opt->ip6po_dest1;
2906                         else
2907                                 newdest = &opt->ip6po_dest2;
2908                         break;
2909                 case IPV6_RTHDRDSTOPTS:
2910                         newdest = &opt->ip6po_dest1;
2911                         break;
2912                 case IPV6_DSTOPTS:
2913                         newdest = &opt->ip6po_dest2;
2914                         break;
2915                 }
2916
2917                 /* turn off the previous option, then set the new option. */
2918                 ip6_clearpktopts(opt, optname);
2919                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2920                 if (*newdest == NULL)
2921                         return (ENOBUFS);
2922                 bcopy(dest, *newdest, destlen);
2923
2924                 break;
2925         }
2926
2927         case IPV6_2292RTHDR:
2928         case IPV6_RTHDR:
2929         {
2930                 struct ip6_rthdr *rth;
2931                 int rthlen;
2932
2933                 if (len == 0) {
2934                         ip6_clearpktopts(opt, IPV6_RTHDR);
2935                         break;  /* just remove the option */
2936                 }
2937
2938                 /* message length validation */
2939                 if (len < sizeof(struct ip6_rthdr))
2940                         return (EINVAL);
2941                 rth = (struct ip6_rthdr *)buf;
2942                 rthlen = (rth->ip6r_len + 1) << 3;
2943                 if (len != rthlen)
2944                         return (EINVAL);
2945
2946                 switch (rth->ip6r_type) {
2947                 case IPV6_RTHDR_TYPE_0:
2948                         if (rth->ip6r_len == 0) /* must contain one addr */
2949                                 return (EINVAL);
2950                         if (rth->ip6r_len % 2) /* length must be even */
2951                                 return (EINVAL);
2952                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2953                                 return (EINVAL);
2954                         break;
2955                 default:
2956                         return (EINVAL);        /* not supported */
2957                 }
2958
2959                 /* turn off the previous option */
2960                 ip6_clearpktopts(opt, IPV6_RTHDR);
2961                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2962                 if (opt->ip6po_rthdr == NULL)
2963                         return (ENOBUFS);
2964                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2965
2966                 break;
2967         }
2968
2969         case IPV6_USE_MIN_MTU:
2970                 if (len != sizeof(int))
2971                         return (EINVAL);
2972                 minmtupolicy = *(int *)buf;
2973                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2974                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2975                     minmtupolicy != IP6PO_MINMTU_ALL) {
2976                         return (EINVAL);
2977                 }
2978                 opt->ip6po_minmtu = minmtupolicy;
2979                 break;
2980
2981         case IPV6_DONTFRAG:
2982                 if (len != sizeof(int))
2983                         return (EINVAL);
2984
2985                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2986                         /*
2987                          * we ignore this option for TCP sockets.
2988                          * (RFC3542 leaves this case unspecified.)
2989                          */
2990                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2991                 } else
2992                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2993                 break;
2994
2995         case IPV6_PREFER_TEMPADDR:
2996                 if (len != sizeof(int))
2997                         return (EINVAL);
2998                 preftemp = *(int *)buf;
2999                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3000                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3001                     preftemp != IP6PO_TEMPADDR_PREFER) {
3002                         return (EINVAL);
3003                 }
3004                 opt->ip6po_prefer_tempaddr = preftemp;
3005                 break;
3006
3007         default:
3008                 return (ENOPROTOOPT);
3009         } /* end of switch */
3010
3011         return (0);
3012 }
3013
3014 /*
3015  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3016  * packet to the input queue of a specified interface.  Note that this
3017  * calls the output routine of the loopback "driver", but with an interface
3018  * pointer that might NOT be &loif -- easier than replicating that code here.
3019  */
3020 void
3021 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
3022 {
3023         struct mbuf *copym;
3024         struct ip6_hdr *ip6;
3025
3026         copym = m_copym(m, 0, M_COPYALL, M_NOWAIT);
3027         if (copym == NULL)
3028                 return;
3029
3030         /*
3031          * Make sure to deep-copy IPv6 header portion in case the data
3032          * is in an mbuf cluster, so that we can safely override the IPv6
3033          * header portion later.
3034          */
3035         if (!M_WRITABLE(copym) ||
3036             copym->m_len < sizeof(struct ip6_hdr)) {
3037                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3038                 if (copym == NULL)
3039                         return;
3040         }
3041         ip6 = mtod(copym, struct ip6_hdr *);
3042         /*
3043          * clear embedded scope identifiers if necessary.
3044          * in6_clearscope will touch the addresses only when necessary.
3045          */
3046         in6_clearscope(&ip6->ip6_src);
3047         in6_clearscope(&ip6->ip6_dst);
3048         if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3049                 copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3050                     CSUM_PSEUDO_HDR;
3051                 copym->m_pkthdr.csum_data = 0xffff;
3052         }
3053         if_simloop(ifp, copym, AF_INET6, 0);
3054 }
3055
3056 /*
3057  * Chop IPv6 header off from the payload.
3058  */
3059 static int
3060 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3061 {
3062         struct mbuf *mh;
3063         struct ip6_hdr *ip6;
3064
3065         ip6 = mtod(m, struct ip6_hdr *);
3066         if (m->m_len > sizeof(*ip6)) {
3067                 mh = m_gethdr(M_NOWAIT, MT_DATA);
3068                 if (mh == NULL) {
3069                         m_freem(m);
3070                         return ENOBUFS;
3071                 }
3072                 m_move_pkthdr(mh, m);
3073                 M_ALIGN(mh, sizeof(*ip6));
3074                 m->m_len -= sizeof(*ip6);
3075                 m->m_data += sizeof(*ip6);
3076                 mh->m_next = m;
3077                 m = mh;
3078                 m->m_len = sizeof(*ip6);
3079                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3080         }
3081         exthdrs->ip6e_ip6 = m;
3082         return 0;
3083 }
3084
3085 /*
3086  * Compute IPv6 extension header length.
3087  */
3088 int
3089 ip6_optlen(struct inpcb *in6p)
3090 {
3091         int len;
3092
3093         if (!in6p->in6p_outputopts)
3094                 return 0;
3095
3096         len = 0;
3097 #define elen(x) \
3098     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3099
3100         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3101         if (in6p->in6p_outputopts->ip6po_rthdr)
3102                 /* dest1 is valid with rthdr only */
3103                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3104         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3105         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3106         return len;
3107 #undef elen
3108 }