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