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_ORIGDSTADDR:
1549                         case IPV6_BINDANY:
1550                         case IPV6_BINDMULTI:
1551 #ifdef  RSS
1552                         case IPV6_RSS_LISTEN_BUCKET:
1553 #endif
1554                                 if (optname == IPV6_BINDANY && td != NULL) {
1555                                         error = priv_check(td,
1556                                             PRIV_NETINET_BINDANY);
1557                                         if (error)
1558                                                 break;
1559                                 }
1560
1561                                 if (optlen != sizeof(int)) {
1562                                         error = EINVAL;
1563                                         break;
1564                                 }
1565                                 error = sooptcopyin(sopt, &optval,
1566                                         sizeof optval, sizeof optval);
1567                                 if (error)
1568                                         break;
1569                                 switch (optname) {
1570
1571                                 case IPV6_UNICAST_HOPS:
1572                                         if (optval < -1 || optval >= 256)
1573                                                 error = EINVAL;
1574                                         else {
1575                                                 /* -1 = kernel default */
1576                                                 in6p->in6p_hops = optval;
1577                                                 if ((in6p->inp_vflag &
1578                                                      INP_IPV4) != 0)
1579                                                         in6p->inp_ip_ttl = optval;
1580                                         }
1581                                         break;
1582 #define OPTSET(bit) \
1583 do { \
1584         INP_WLOCK(in6p); \
1585         if (optval) \
1586                 in6p->inp_flags |= (bit); \
1587         else \
1588                 in6p->inp_flags &= ~(bit); \
1589         INP_WUNLOCK(in6p); \
1590 } while (/*CONSTCOND*/ 0)
1591 #define OPTSET2292(bit) \
1592 do { \
1593         INP_WLOCK(in6p); \
1594         in6p->inp_flags |= IN6P_RFC2292; \
1595         if (optval) \
1596                 in6p->inp_flags |= (bit); \
1597         else \
1598                 in6p->inp_flags &= ~(bit); \
1599         INP_WUNLOCK(in6p); \
1600 } while (/*CONSTCOND*/ 0)
1601 #define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
1602
1603 #define OPTSET2(bit, val) do {                                          \
1604         INP_WLOCK(in6p);                                                \
1605         if (val)                                                        \
1606                 in6p->inp_flags2 |= bit;                                \
1607         else                                                            \
1608                 in6p->inp_flags2 &= ~bit;                               \
1609         INP_WUNLOCK(in6p);                                              \
1610 } while (0)
1611 #define OPTBIT2(bit) (in6p->inp_flags2 & (bit) ? 1 : 0)
1612
1613                                 case IPV6_RECVPKTINFO:
1614                                         /* cannot mix with RFC2292 */
1615                                         if (OPTBIT(IN6P_RFC2292)) {
1616                                                 error = EINVAL;
1617                                                 break;
1618                                         }
1619                                         OPTSET(IN6P_PKTINFO);
1620                                         break;
1621
1622                                 case IPV6_HOPLIMIT:
1623                                 {
1624                                         struct ip6_pktopts **optp;
1625
1626                                         /* cannot mix with RFC2292 */
1627                                         if (OPTBIT(IN6P_RFC2292)) {
1628                                                 error = EINVAL;
1629                                                 break;
1630                                         }
1631                                         optp = &in6p->in6p_outputopts;
1632                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1633                                             (u_char *)&optval, sizeof(optval),
1634                                             optp, (td != NULL) ? td->td_ucred :
1635                                             NULL, uproto);
1636                                         break;
1637                                 }
1638
1639                                 case IPV6_RECVHOPLIMIT:
1640                                         /* cannot mix with RFC2292 */
1641                                         if (OPTBIT(IN6P_RFC2292)) {
1642                                                 error = EINVAL;
1643                                                 break;
1644                                         }
1645                                         OPTSET(IN6P_HOPLIMIT);
1646                                         break;
1647
1648                                 case IPV6_RECVHOPOPTS:
1649                                         /* cannot mix with RFC2292 */
1650                                         if (OPTBIT(IN6P_RFC2292)) {
1651                                                 error = EINVAL;
1652                                                 break;
1653                                         }
1654                                         OPTSET(IN6P_HOPOPTS);
1655                                         break;
1656
1657                                 case IPV6_RECVDSTOPTS:
1658                                         /* cannot mix with RFC2292 */
1659                                         if (OPTBIT(IN6P_RFC2292)) {
1660                                                 error = EINVAL;
1661                                                 break;
1662                                         }
1663                                         OPTSET(IN6P_DSTOPTS);
1664                                         break;
1665
1666                                 case IPV6_RECVRTHDRDSTOPTS:
1667                                         /* cannot mix with RFC2292 */
1668                                         if (OPTBIT(IN6P_RFC2292)) {
1669                                                 error = EINVAL;
1670                                                 break;
1671                                         }
1672                                         OPTSET(IN6P_RTHDRDSTOPTS);
1673                                         break;
1674
1675                                 case IPV6_RECVRTHDR:
1676                                         /* cannot mix with RFC2292 */
1677                                         if (OPTBIT(IN6P_RFC2292)) {
1678                                                 error = EINVAL;
1679                                                 break;
1680                                         }
1681                                         OPTSET(IN6P_RTHDR);
1682                                         break;
1683
1684                                 case IPV6_RECVPATHMTU:
1685                                         /*
1686                                          * We ignore this option for TCP
1687                                          * sockets.
1688                                          * (RFC3542 leaves this case
1689                                          * unspecified.)
1690                                          */
1691                                         if (uproto != IPPROTO_TCP)
1692                                                 OPTSET(IN6P_MTU);
1693                                         break;
1694
1695                                 case IPV6_RECVFLOWID:
1696                                         OPTSET2(INP_RECVFLOWID, optval);
1697                                         break;
1698
1699 #ifdef  RSS
1700                                 case IPV6_RECVRSSBUCKETID:
1701                                         OPTSET2(INP_RECVRSSBUCKETID, optval);
1702                                         break;
1703 #endif
1704
1705                                 case IPV6_V6ONLY:
1706                                         /*
1707                                          * make setsockopt(IPV6_V6ONLY)
1708                                          * available only prior to bind(2).
1709                                          * see ipng mailing list, Jun 22 2001.
1710                                          */
1711                                         if (in6p->inp_lport ||
1712                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1713                                                 error = EINVAL;
1714                                                 break;
1715                                         }
1716                                         OPTSET(IN6P_IPV6_V6ONLY);
1717                                         if (optval)
1718                                                 in6p->inp_vflag &= ~INP_IPV4;
1719                                         else
1720                                                 in6p->inp_vflag |= INP_IPV4;
1721                                         break;
1722                                 case IPV6_RECVTCLASS:
1723                                         /* cannot mix with RFC2292 XXX */
1724                                         if (OPTBIT(IN6P_RFC2292)) {
1725                                                 error = EINVAL;
1726                                                 break;
1727                                         }
1728                                         OPTSET(IN6P_TCLASS);
1729                                         break;
1730                                 case IPV6_AUTOFLOWLABEL:
1731                                         OPTSET(IN6P_AUTOFLOWLABEL);
1732                                         break;
1733
1734                                 case IPV6_ORIGDSTADDR:
1735                                         OPTSET2(INP_ORIGDSTADDR, optval);
1736                                         break;
1737                                 case IPV6_BINDANY:
1738                                         OPTSET(INP_BINDANY);
1739                                         break;
1740
1741                                 case IPV6_BINDMULTI:
1742                                         OPTSET2(INP_BINDMULTI, optval);
1743                                         break;
1744 #ifdef  RSS
1745                                 case IPV6_RSS_LISTEN_BUCKET:
1746                                         if ((optval >= 0) &&
1747                                             (optval < rss_getnumbuckets())) {
1748                                                 in6p->inp_rss_listen_bucket = optval;
1749                                                 OPTSET2(INP_RSS_BUCKET_SET, 1);
1750                                         } else {
1751                                                 error = EINVAL;
1752                                         }
1753                                         break;
1754 #endif
1755                                 }
1756                                 break;
1757
1758                         case IPV6_TCLASS:
1759                         case IPV6_DONTFRAG:
1760                         case IPV6_USE_MIN_MTU:
1761                         case IPV6_PREFER_TEMPADDR:
1762                                 if (optlen != sizeof(optval)) {
1763                                         error = EINVAL;
1764                                         break;
1765                                 }
1766                                 error = sooptcopyin(sopt, &optval,
1767                                         sizeof optval, sizeof optval);
1768                                 if (error)
1769                                         break;
1770                                 {
1771                                         struct ip6_pktopts **optp;
1772                                         optp = &in6p->in6p_outputopts;
1773                                         error = ip6_pcbopt(optname,
1774                                             (u_char *)&optval, sizeof(optval),
1775                                             optp, (td != NULL) ? td->td_ucred :
1776                                             NULL, uproto);
1777                                         break;
1778                                 }
1779
1780                         case IPV6_2292PKTINFO:
1781                         case IPV6_2292HOPLIMIT:
1782                         case IPV6_2292HOPOPTS:
1783                         case IPV6_2292DSTOPTS:
1784                         case IPV6_2292RTHDR:
1785                                 /* RFC 2292 */
1786                                 if (optlen != sizeof(int)) {
1787                                         error = EINVAL;
1788                                         break;
1789                                 }
1790                                 error = sooptcopyin(sopt, &optval,
1791                                         sizeof optval, sizeof optval);
1792                                 if (error)
1793                                         break;
1794                                 switch (optname) {
1795                                 case IPV6_2292PKTINFO:
1796                                         OPTSET2292(IN6P_PKTINFO);
1797                                         break;
1798                                 case IPV6_2292HOPLIMIT:
1799                                         OPTSET2292(IN6P_HOPLIMIT);
1800                                         break;
1801                                 case IPV6_2292HOPOPTS:
1802                                         /*
1803                                          * Check super-user privilege.
1804                                          * See comments for IPV6_RECVHOPOPTS.
1805                                          */
1806                                         if (td != NULL) {
1807                                                 error = priv_check(td,
1808                                                     PRIV_NETINET_SETHDROPTS);
1809                                                 if (error)
1810                                                         return (error);
1811                                         }
1812                                         OPTSET2292(IN6P_HOPOPTS);
1813                                         break;
1814                                 case IPV6_2292DSTOPTS:
1815                                         if (td != NULL) {
1816                                                 error = priv_check(td,
1817                                                     PRIV_NETINET_SETHDROPTS);
1818                                                 if (error)
1819                                                         return (error);
1820                                         }
1821                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1822                                         break;
1823                                 case IPV6_2292RTHDR:
1824                                         OPTSET2292(IN6P_RTHDR);
1825                                         break;
1826                                 }
1827                                 break;
1828                         case IPV6_PKTINFO:
1829                         case IPV6_HOPOPTS:
1830                         case IPV6_RTHDR:
1831                         case IPV6_DSTOPTS:
1832                         case IPV6_RTHDRDSTOPTS:
1833                         case IPV6_NEXTHOP:
1834                         {
1835                                 /* new advanced API (RFC3542) */
1836                                 u_char *optbuf;
1837                                 u_char optbuf_storage[MCLBYTES];
1838                                 int optlen;
1839                                 struct ip6_pktopts **optp;
1840
1841                                 /* cannot mix with RFC2292 */
1842                                 if (OPTBIT(IN6P_RFC2292)) {
1843                                         error = EINVAL;
1844                                         break;
1845                                 }
1846
1847                                 /*
1848                                  * We only ensure valsize is not too large
1849                                  * here.  Further validation will be done
1850                                  * later.
1851                                  */
1852                                 error = sooptcopyin(sopt, optbuf_storage,
1853                                     sizeof(optbuf_storage), 0);
1854                                 if (error)
1855                                         break;
1856                                 optlen = sopt->sopt_valsize;
1857                                 optbuf = optbuf_storage;
1858                                 optp = &in6p->in6p_outputopts;
1859                                 error = ip6_pcbopt(optname, optbuf, optlen,
1860                                     optp, (td != NULL) ? td->td_ucred : NULL,
1861                                     uproto);
1862                                 break;
1863                         }
1864 #undef OPTSET
1865
1866                         case IPV6_MULTICAST_IF:
1867                         case IPV6_MULTICAST_HOPS:
1868                         case IPV6_MULTICAST_LOOP:
1869                         case IPV6_JOIN_GROUP:
1870                         case IPV6_LEAVE_GROUP:
1871                         case IPV6_MSFILTER:
1872                         case MCAST_BLOCK_SOURCE:
1873                         case MCAST_UNBLOCK_SOURCE:
1874                         case MCAST_JOIN_GROUP:
1875                         case MCAST_LEAVE_GROUP:
1876                         case MCAST_JOIN_SOURCE_GROUP:
1877                         case MCAST_LEAVE_SOURCE_GROUP:
1878                                 error = ip6_setmoptions(in6p, sopt);
1879                                 break;
1880
1881                         case IPV6_PORTRANGE:
1882                                 error = sooptcopyin(sopt, &optval,
1883                                     sizeof optval, sizeof optval);
1884                                 if (error)
1885                                         break;
1886
1887                                 INP_WLOCK(in6p);
1888                                 switch (optval) {
1889                                 case IPV6_PORTRANGE_DEFAULT:
1890                                         in6p->inp_flags &= ~(INP_LOWPORT);
1891                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1892                                         break;
1893
1894                                 case IPV6_PORTRANGE_HIGH:
1895                                         in6p->inp_flags &= ~(INP_LOWPORT);
1896                                         in6p->inp_flags |= INP_HIGHPORT;
1897                                         break;
1898
1899                                 case IPV6_PORTRANGE_LOW:
1900                                         in6p->inp_flags &= ~(INP_HIGHPORT);
1901                                         in6p->inp_flags |= INP_LOWPORT;
1902                                         break;
1903
1904                                 default:
1905                                         error = EINVAL;
1906                                         break;
1907                                 }
1908                                 INP_WUNLOCK(in6p);
1909                                 break;
1910
1911 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1912                         case IPV6_IPSEC_POLICY:
1913                                 if (IPSEC_ENABLED(ipv6)) {
1914                                         error = IPSEC_PCBCTL(ipv6, in6p, sopt);
1915                                         break;
1916                                 }
1917                                 /* FALLTHROUGH */
1918 #endif /* IPSEC */
1919
1920                         default:
1921                                 error = ENOPROTOOPT;
1922                                 break;
1923                         }
1924                         break;
1925
1926                 case SOPT_GET:
1927                         switch (optname) {
1928
1929                         case IPV6_2292PKTOPTIONS:
1930 #ifdef IPV6_PKTOPTIONS
1931                         case IPV6_PKTOPTIONS:
1932 #endif
1933                                 /*
1934                                  * RFC3542 (effectively) deprecated the
1935                                  * semantics of the 2292-style pktoptions.
1936                                  * Since it was not reliable in nature (i.e.,
1937                                  * applications had to expect the lack of some
1938                                  * information after all), it would make sense
1939                                  * to simplify this part by always returning
1940                                  * empty data.
1941                                  */
1942                                 sopt->sopt_valsize = 0;
1943                                 break;
1944
1945                         case IPV6_RECVHOPOPTS:
1946                         case IPV6_RECVDSTOPTS:
1947                         case IPV6_RECVRTHDRDSTOPTS:
1948                         case IPV6_UNICAST_HOPS:
1949                         case IPV6_RECVPKTINFO:
1950                         case IPV6_RECVHOPLIMIT:
1951                         case IPV6_RECVRTHDR:
1952                         case IPV6_RECVPATHMTU:
1953
1954                         case IPV6_V6ONLY:
1955                         case IPV6_PORTRANGE:
1956                         case IPV6_RECVTCLASS:
1957                         case IPV6_AUTOFLOWLABEL:
1958                         case IPV6_BINDANY:
1959                         case IPV6_FLOWID:
1960                         case IPV6_FLOWTYPE:
1961                         case IPV6_RECVFLOWID:
1962 #ifdef  RSS
1963                         case IPV6_RSSBUCKETID:
1964                         case IPV6_RECVRSSBUCKETID:
1965 #endif
1966                         case IPV6_BINDMULTI:
1967                                 switch (optname) {
1968
1969                                 case IPV6_RECVHOPOPTS:
1970                                         optval = OPTBIT(IN6P_HOPOPTS);
1971                                         break;
1972
1973                                 case IPV6_RECVDSTOPTS:
1974                                         optval = OPTBIT(IN6P_DSTOPTS);
1975                                         break;
1976
1977                                 case IPV6_RECVRTHDRDSTOPTS:
1978                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1979                                         break;
1980
1981                                 case IPV6_UNICAST_HOPS:
1982                                         optval = in6p->in6p_hops;
1983                                         break;
1984
1985                                 case IPV6_RECVPKTINFO:
1986                                         optval = OPTBIT(IN6P_PKTINFO);
1987                                         break;
1988
1989                                 case IPV6_RECVHOPLIMIT:
1990                                         optval = OPTBIT(IN6P_HOPLIMIT);
1991                                         break;
1992
1993                                 case IPV6_RECVRTHDR:
1994                                         optval = OPTBIT(IN6P_RTHDR);
1995                                         break;
1996
1997                                 case IPV6_RECVPATHMTU:
1998                                         optval = OPTBIT(IN6P_MTU);
1999                                         break;
2000
2001                                 case IPV6_V6ONLY:
2002                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
2003                                         break;
2004
2005                                 case IPV6_PORTRANGE:
2006                                     {
2007                                         int flags;
2008                                         flags = in6p->inp_flags;
2009                                         if (flags & INP_HIGHPORT)
2010                                                 optval = IPV6_PORTRANGE_HIGH;
2011                                         else if (flags & INP_LOWPORT)
2012                                                 optval = IPV6_PORTRANGE_LOW;
2013                                         else
2014                                                 optval = 0;
2015                                         break;
2016                                     }
2017                                 case IPV6_RECVTCLASS:
2018                                         optval = OPTBIT(IN6P_TCLASS);
2019                                         break;
2020
2021                                 case IPV6_AUTOFLOWLABEL:
2022                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
2023                                         break;
2024
2025                                 case IPV6_ORIGDSTADDR:
2026                                         optval = OPTBIT2(INP_ORIGDSTADDR);
2027                                         break;
2028
2029                                 case IPV6_BINDANY:
2030                                         optval = OPTBIT(INP_BINDANY);
2031                                         break;
2032
2033                                 case IPV6_FLOWID:
2034                                         optval = in6p->inp_flowid;
2035                                         break;
2036
2037                                 case IPV6_FLOWTYPE:
2038                                         optval = in6p->inp_flowtype;
2039                                         break;
2040
2041                                 case IPV6_RECVFLOWID:
2042                                         optval = OPTBIT2(INP_RECVFLOWID);
2043                                         break;
2044 #ifdef  RSS
2045                                 case IPV6_RSSBUCKETID:
2046                                         retval =
2047                                             rss_hash2bucket(in6p->inp_flowid,
2048                                             in6p->inp_flowtype,
2049                                             &rss_bucket);
2050                                         if (retval == 0)
2051                                                 optval = rss_bucket;
2052                                         else
2053                                                 error = EINVAL;
2054                                         break;
2055
2056                                 case IPV6_RECVRSSBUCKETID:
2057                                         optval = OPTBIT2(INP_RECVRSSBUCKETID);
2058                                         break;
2059 #endif
2060
2061                                 case IPV6_BINDMULTI:
2062                                         optval = OPTBIT2(INP_BINDMULTI);
2063                                         break;
2064
2065                                 }
2066                                 if (error)
2067                                         break;
2068                                 error = sooptcopyout(sopt, &optval,
2069                                         sizeof optval);
2070                                 break;
2071
2072                         case IPV6_PATHMTU:
2073                         {
2074                                 u_long pmtu = 0;
2075                                 struct ip6_mtuinfo mtuinfo;
2076
2077                                 if (!(so->so_state & SS_ISCONNECTED))
2078                                         return (ENOTCONN);
2079                                 /*
2080                                  * XXX: we dot not consider the case of source
2081                                  * routing, or optional information to specify
2082                                  * the outgoing interface.
2083                                  */
2084                                 error = ip6_getpmtu_ctl(so->so_fibnum,
2085                                     &in6p->in6p_faddr, &pmtu);
2086                                 if (error)
2087                                         break;
2088                                 if (pmtu > IPV6_MAXPACKET)
2089                                         pmtu = IPV6_MAXPACKET;
2090
2091                                 bzero(&mtuinfo, sizeof(mtuinfo));
2092                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
2093                                 optdata = (void *)&mtuinfo;
2094                                 optdatalen = sizeof(mtuinfo);
2095                                 error = sooptcopyout(sopt, optdata,
2096                                     optdatalen);
2097                                 break;
2098                         }
2099
2100                         case IPV6_2292PKTINFO:
2101                         case IPV6_2292HOPLIMIT:
2102                         case IPV6_2292HOPOPTS:
2103                         case IPV6_2292RTHDR:
2104                         case IPV6_2292DSTOPTS:
2105                                 switch (optname) {
2106                                 case IPV6_2292PKTINFO:
2107                                         optval = OPTBIT(IN6P_PKTINFO);
2108                                         break;
2109                                 case IPV6_2292HOPLIMIT:
2110                                         optval = OPTBIT(IN6P_HOPLIMIT);
2111                                         break;
2112                                 case IPV6_2292HOPOPTS:
2113                                         optval = OPTBIT(IN6P_HOPOPTS);
2114                                         break;
2115                                 case IPV6_2292RTHDR:
2116                                         optval = OPTBIT(IN6P_RTHDR);
2117                                         break;
2118                                 case IPV6_2292DSTOPTS:
2119                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
2120                                         break;
2121                                 }
2122                                 error = sooptcopyout(sopt, &optval,
2123                                     sizeof optval);
2124                                 break;
2125                         case IPV6_PKTINFO:
2126                         case IPV6_HOPOPTS:
2127                         case IPV6_RTHDR:
2128                         case IPV6_DSTOPTS:
2129                         case IPV6_RTHDRDSTOPTS:
2130                         case IPV6_NEXTHOP:
2131                         case IPV6_TCLASS:
2132                         case IPV6_DONTFRAG:
2133                         case IPV6_USE_MIN_MTU:
2134                         case IPV6_PREFER_TEMPADDR:
2135                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
2136                                     optname, sopt);
2137                                 break;
2138
2139                         case IPV6_MULTICAST_IF:
2140                         case IPV6_MULTICAST_HOPS:
2141                         case IPV6_MULTICAST_LOOP:
2142                         case IPV6_MSFILTER:
2143                                 error = ip6_getmoptions(in6p, sopt);
2144                                 break;
2145
2146 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
2147                         case IPV6_IPSEC_POLICY:
2148                                 if (IPSEC_ENABLED(ipv6)) {
2149                                         error = IPSEC_PCBCTL(ipv6, in6p, sopt);
2150                                         break;
2151                                 }
2152                                 /* FALLTHROUGH */
2153 #endif /* IPSEC */
2154                         default:
2155                                 error = ENOPROTOOPT;
2156                                 break;
2157                         }
2158                         break;
2159                 }
2160         }
2161         return (error);
2162 }
2163
2164 int
2165 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2166 {
2167         int error = 0, optval, optlen;
2168         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2169         struct inpcb *in6p = sotoinpcb(so);
2170         int level, op, optname;
2171
2172         level = sopt->sopt_level;
2173         op = sopt->sopt_dir;
2174         optname = sopt->sopt_name;
2175         optlen = sopt->sopt_valsize;
2176
2177         if (level != IPPROTO_IPV6) {
2178                 return (EINVAL);
2179         }
2180
2181         switch (optname) {
2182         case IPV6_CHECKSUM:
2183                 /*
2184                  * For ICMPv6 sockets, no modification allowed for checksum
2185                  * offset, permit "no change" values to help existing apps.
2186                  *
2187                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2188                  * for an ICMPv6 socket will fail."
2189                  * The current behavior does not meet RFC3542.
2190                  */
2191                 switch (op) {
2192                 case SOPT_SET:
2193                         if (optlen != sizeof(int)) {
2194                                 error = EINVAL;
2195                                 break;
2196                         }
2197                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2198                                             sizeof(optval));
2199                         if (error)
2200                                 break;
2201                         if ((optval % 2) != 0) {
2202                                 /* the API assumes even offset values */
2203                                 error = EINVAL;
2204                         } else if (so->so_proto->pr_protocol ==
2205                             IPPROTO_ICMPV6) {
2206                                 if (optval != icmp6off)
2207                                         error = EINVAL;
2208                         } else
2209                                 in6p->in6p_cksum = optval;
2210                         break;
2211
2212                 case SOPT_GET:
2213                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2214                                 optval = icmp6off;
2215                         else
2216                                 optval = in6p->in6p_cksum;
2217
2218                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2219                         break;
2220
2221                 default:
2222                         error = EINVAL;
2223                         break;
2224                 }
2225                 break;
2226
2227         default:
2228                 error = ENOPROTOOPT;
2229                 break;
2230         }
2231
2232         return (error);
2233 }
2234
2235 /*
2236  * Set up IP6 options in pcb for insertion in output packets or
2237  * specifying behavior of outgoing packets.
2238  */
2239 static int
2240 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2241     struct socket *so, struct sockopt *sopt)
2242 {
2243         struct ip6_pktopts *opt = *pktopt;
2244         int error = 0;
2245         struct thread *td = sopt->sopt_td;
2246
2247         /* turn off any old options. */
2248         if (opt) {
2249 #ifdef DIAGNOSTIC
2250                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2251                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2252                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2253                         printf("ip6_pcbopts: all specified options are cleared.\n");
2254 #endif
2255                 ip6_clearpktopts(opt, -1);
2256         } else
2257                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2258         *pktopt = NULL;
2259
2260         if (!m || m->m_len == 0) {
2261                 /*
2262                  * Only turning off any previous options, regardless of
2263                  * whether the opt is just created or given.
2264                  */
2265                 free(opt, M_IP6OPT);
2266                 return (0);
2267         }
2268
2269         /*  set options specified by user. */
2270         if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
2271             td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
2272                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2273                 free(opt, M_IP6OPT);
2274                 return (error);
2275         }
2276         *pktopt = opt;
2277         return (0);
2278 }
2279
2280 /*
2281  * initialize ip6_pktopts.  beware that there are non-zero default values in
2282  * the struct.
2283  */
2284 void
2285 ip6_initpktopts(struct ip6_pktopts *opt)
2286 {
2287
2288         bzero(opt, sizeof(*opt));
2289         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2290         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2291         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2292         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2293 }
2294
2295 static int
2296 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2297     struct ucred *cred, int uproto)
2298 {
2299         struct ip6_pktopts *opt;
2300
2301         if (*pktopt == NULL) {
2302                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2303                     M_WAITOK);
2304                 ip6_initpktopts(*pktopt);
2305         }
2306         opt = *pktopt;
2307
2308         return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
2309 }
2310
2311 static int
2312 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2313 {
2314         void *optdata = NULL;
2315         int optdatalen = 0;
2316         struct ip6_ext *ip6e;
2317         int error = 0;
2318         struct in6_pktinfo null_pktinfo;
2319         int deftclass = 0, on;
2320         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2321         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2322
2323         switch (optname) {
2324         case IPV6_PKTINFO:
2325                 optdata = (void *)&null_pktinfo;
2326                 if (pktopt && pktopt->ip6po_pktinfo) {
2327                         bcopy(pktopt->ip6po_pktinfo, &null_pktinfo,
2328                             sizeof(null_pktinfo));
2329                         in6_clearscope(&null_pktinfo.ipi6_addr);
2330                 } else {
2331                         /* XXX: we don't have to do this every time... */
2332                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2333                 }
2334                 optdatalen = sizeof(struct in6_pktinfo);
2335                 break;
2336         case IPV6_TCLASS:
2337                 if (pktopt && pktopt->ip6po_tclass >= 0)
2338                         optdata = (void *)&pktopt->ip6po_tclass;
2339                 else
2340                         optdata = (void *)&deftclass;
2341                 optdatalen = sizeof(int);
2342                 break;
2343         case IPV6_HOPOPTS:
2344                 if (pktopt && pktopt->ip6po_hbh) {
2345                         optdata = (void *)pktopt->ip6po_hbh;
2346                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2347                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2348                 }
2349                 break;
2350         case IPV6_RTHDR:
2351                 if (pktopt && pktopt->ip6po_rthdr) {
2352                         optdata = (void *)pktopt->ip6po_rthdr;
2353                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2354                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2355                 }
2356                 break;
2357         case IPV6_RTHDRDSTOPTS:
2358                 if (pktopt && pktopt->ip6po_dest1) {
2359                         optdata = (void *)pktopt->ip6po_dest1;
2360                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2361                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2362                 }
2363                 break;
2364         case IPV6_DSTOPTS:
2365                 if (pktopt && pktopt->ip6po_dest2) {
2366                         optdata = (void *)pktopt->ip6po_dest2;
2367                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2368                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2369                 }
2370                 break;
2371         case IPV6_NEXTHOP:
2372                 if (pktopt && pktopt->ip6po_nexthop) {
2373                         optdata = (void *)pktopt->ip6po_nexthop;
2374                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2375                 }
2376                 break;
2377         case IPV6_USE_MIN_MTU:
2378                 if (pktopt)
2379                         optdata = (void *)&pktopt->ip6po_minmtu;
2380                 else
2381                         optdata = (void *)&defminmtu;
2382                 optdatalen = sizeof(int);
2383                 break;
2384         case IPV6_DONTFRAG:
2385                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2386                         on = 1;
2387                 else
2388                         on = 0;
2389                 optdata = (void *)&on;
2390                 optdatalen = sizeof(on);
2391                 break;
2392         case IPV6_PREFER_TEMPADDR:
2393                 if (pktopt)
2394                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2395                 else
2396                         optdata = (void *)&defpreftemp;
2397                 optdatalen = sizeof(int);
2398                 break;
2399         default:                /* should not happen */
2400 #ifdef DIAGNOSTIC
2401                 panic("ip6_getpcbopt: unexpected option\n");
2402 #endif
2403                 return (ENOPROTOOPT);
2404         }
2405
2406         error = sooptcopyout(sopt, optdata, optdatalen);
2407
2408         return (error);
2409 }
2410
2411 void
2412 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2413 {
2414         if (pktopt == NULL)
2415                 return;
2416
2417         if (optname == -1 || optname == IPV6_PKTINFO) {
2418                 if (pktopt->ip6po_pktinfo)
2419                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2420                 pktopt->ip6po_pktinfo = NULL;
2421         }
2422         if (optname == -1 || optname == IPV6_HOPLIMIT)
2423                 pktopt->ip6po_hlim = -1;
2424         if (optname == -1 || optname == IPV6_TCLASS)
2425                 pktopt->ip6po_tclass = -1;
2426         if (optname == -1 || optname == IPV6_NEXTHOP) {
2427                 if (pktopt->ip6po_nextroute.ro_rt) {
2428                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2429                         pktopt->ip6po_nextroute.ro_rt = NULL;
2430                 }
2431                 if (pktopt->ip6po_nexthop)
2432                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2433                 pktopt->ip6po_nexthop = NULL;
2434         }
2435         if (optname == -1 || optname == IPV6_HOPOPTS) {
2436                 if (pktopt->ip6po_hbh)
2437                         free(pktopt->ip6po_hbh, M_IP6OPT);
2438                 pktopt->ip6po_hbh = NULL;
2439         }
2440         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2441                 if (pktopt->ip6po_dest1)
2442                         free(pktopt->ip6po_dest1, M_IP6OPT);
2443                 pktopt->ip6po_dest1 = NULL;
2444         }
2445         if (optname == -1 || optname == IPV6_RTHDR) {
2446                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2447                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2448                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2449                 if (pktopt->ip6po_route.ro_rt) {
2450                         RTFREE(pktopt->ip6po_route.ro_rt);
2451                         pktopt->ip6po_route.ro_rt = NULL;
2452                 }
2453         }
2454         if (optname == -1 || optname == IPV6_DSTOPTS) {
2455                 if (pktopt->ip6po_dest2)
2456                         free(pktopt->ip6po_dest2, M_IP6OPT);
2457                 pktopt->ip6po_dest2 = NULL;
2458         }
2459 }
2460
2461 #define PKTOPT_EXTHDRCPY(type) \
2462 do {\
2463         if (src->type) {\
2464                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2465                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2466                 if (dst->type == NULL && canwait == M_NOWAIT)\
2467                         goto bad;\
2468                 bcopy(src->type, dst->type, hlen);\
2469         }\
2470 } while (/*CONSTCOND*/ 0)
2471
2472 static int
2473 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2474 {
2475         if (dst == NULL || src == NULL)  {
2476                 printf("ip6_clearpktopts: invalid argument\n");
2477                 return (EINVAL);
2478         }
2479
2480         dst->ip6po_hlim = src->ip6po_hlim;
2481         dst->ip6po_tclass = src->ip6po_tclass;
2482         dst->ip6po_flags = src->ip6po_flags;
2483         dst->ip6po_minmtu = src->ip6po_minmtu;
2484         dst->ip6po_prefer_tempaddr = src->ip6po_prefer_tempaddr;
2485         if (src->ip6po_pktinfo) {
2486                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2487                     M_IP6OPT, canwait);
2488                 if (dst->ip6po_pktinfo == NULL)
2489                         goto bad;
2490                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2491         }
2492         if (src->ip6po_nexthop) {
2493                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2494                     M_IP6OPT, canwait);
2495                 if (dst->ip6po_nexthop == NULL)
2496                         goto bad;
2497                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2498                     src->ip6po_nexthop->sa_len);
2499         }
2500         PKTOPT_EXTHDRCPY(ip6po_hbh);
2501         PKTOPT_EXTHDRCPY(ip6po_dest1);
2502         PKTOPT_EXTHDRCPY(ip6po_dest2);
2503         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2504         return (0);
2505
2506   bad:
2507         ip6_clearpktopts(dst, -1);
2508         return (ENOBUFS);
2509 }
2510 #undef PKTOPT_EXTHDRCPY
2511
2512 struct ip6_pktopts *
2513 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2514 {
2515         int error;
2516         struct ip6_pktopts *dst;
2517
2518         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2519         if (dst == NULL)
2520                 return (NULL);
2521         ip6_initpktopts(dst);
2522
2523         if ((error = copypktopts(dst, src, canwait)) != 0) {
2524                 free(dst, M_IP6OPT);
2525                 return (NULL);
2526         }
2527
2528         return (dst);
2529 }
2530
2531 void
2532 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2533 {
2534         if (pktopt == NULL)
2535                 return;
2536
2537         ip6_clearpktopts(pktopt, -1);
2538
2539         free(pktopt, M_IP6OPT);
2540 }
2541
2542 /*
2543  * Set IPv6 outgoing packet options based on advanced API.
2544  */
2545 int
2546 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2547     struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
2548 {
2549         struct cmsghdr *cm = NULL;
2550
2551         if (control == NULL || opt == NULL)
2552                 return (EINVAL);
2553
2554         ip6_initpktopts(opt);
2555         if (stickyopt) {
2556                 int error;
2557
2558                 /*
2559                  * If stickyopt is provided, make a local copy of the options
2560                  * for this particular packet, then override them by ancillary
2561                  * objects.
2562                  * XXX: copypktopts() does not copy the cached route to a next
2563                  * hop (if any).  This is not very good in terms of efficiency,
2564                  * but we can allow this since this option should be rarely
2565                  * used.
2566                  */
2567                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2568                         return (error);
2569         }
2570
2571         /*
2572          * XXX: Currently, we assume all the optional information is stored
2573          * in a single mbuf.
2574          */
2575         if (control->m_next)
2576                 return (EINVAL);
2577
2578         for (; control->m_len > 0; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2579             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2580                 int error;
2581
2582                 if (control->m_len < CMSG_LEN(0))
2583                         return (EINVAL);
2584
2585                 cm = mtod(control, struct cmsghdr *);
2586                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2587                         return (EINVAL);
2588                 if (cm->cmsg_level != IPPROTO_IPV6)
2589                         continue;
2590
2591                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2592                     cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
2593                 if (error)
2594                         return (error);
2595         }
2596
2597         return (0);
2598 }
2599
2600 /*
2601  * Set a particular packet option, as a sticky option or an ancillary data
2602  * item.  "len" can be 0 only when it's a sticky option.
2603  * We have 4 cases of combination of "sticky" and "cmsg":
2604  * "sticky=0, cmsg=0": impossible
2605  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2606  * "sticky=1, cmsg=0": RFC3542 socket option
2607  * "sticky=1, cmsg=1": RFC2292 socket option
2608  */
2609 static int
2610 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2611     struct ucred *cred, int sticky, int cmsg, int uproto)
2612 {
2613         int minmtupolicy, preftemp;
2614         int error;
2615
2616         if (!sticky && !cmsg) {
2617 #ifdef DIAGNOSTIC
2618                 printf("ip6_setpktopt: impossible case\n");
2619 #endif
2620                 return (EINVAL);
2621         }
2622
2623         /*
2624          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2625          * not be specified in the context of RFC3542.  Conversely,
2626          * RFC3542 types should not be specified in the context of RFC2292.
2627          */
2628         if (!cmsg) {
2629                 switch (optname) {
2630                 case IPV6_2292PKTINFO:
2631                 case IPV6_2292HOPLIMIT:
2632                 case IPV6_2292NEXTHOP:
2633                 case IPV6_2292HOPOPTS:
2634                 case IPV6_2292DSTOPTS:
2635                 case IPV6_2292RTHDR:
2636                 case IPV6_2292PKTOPTIONS:
2637                         return (ENOPROTOOPT);
2638                 }
2639         }
2640         if (sticky && cmsg) {
2641                 switch (optname) {
2642                 case IPV6_PKTINFO:
2643                 case IPV6_HOPLIMIT:
2644                 case IPV6_NEXTHOP:
2645                 case IPV6_HOPOPTS:
2646                 case IPV6_DSTOPTS:
2647                 case IPV6_RTHDRDSTOPTS:
2648                 case IPV6_RTHDR:
2649                 case IPV6_USE_MIN_MTU:
2650                 case IPV6_DONTFRAG:
2651                 case IPV6_TCLASS:
2652                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2653                         return (ENOPROTOOPT);
2654                 }
2655         }
2656
2657         switch (optname) {
2658         case IPV6_2292PKTINFO:
2659         case IPV6_PKTINFO:
2660         {
2661                 struct ifnet *ifp = NULL;
2662                 struct in6_pktinfo *pktinfo;
2663
2664                 if (len != sizeof(struct in6_pktinfo))
2665                         return (EINVAL);
2666
2667                 pktinfo = (struct in6_pktinfo *)buf;
2668
2669                 /*
2670                  * An application can clear any sticky IPV6_PKTINFO option by
2671                  * doing a "regular" setsockopt with ipi6_addr being
2672                  * in6addr_any and ipi6_ifindex being zero.
2673                  * [RFC 3542, Section 6]
2674                  */
2675                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2676                     pktinfo->ipi6_ifindex == 0 &&
2677                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2678                         ip6_clearpktopts(opt, optname);
2679                         break;
2680                 }
2681
2682                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2683                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2684                         return (EINVAL);
2685                 }
2686                 if (IN6_IS_ADDR_MULTICAST(&pktinfo->ipi6_addr))
2687                         return (EINVAL);
2688                 /* validate the interface index if specified. */
2689                 if (pktinfo->ipi6_ifindex > V_if_index)
2690                          return (ENXIO);
2691                 if (pktinfo->ipi6_ifindex) {
2692                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2693                         if (ifp == NULL)
2694                                 return (ENXIO);
2695                 }
2696                 if (ifp != NULL && (ifp->if_afdata[AF_INET6] == NULL ||
2697                     (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0))
2698                         return (ENETDOWN);
2699
2700                 if (ifp != NULL &&
2701                     !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2702                         struct in6_ifaddr *ia;
2703
2704                         in6_setscope(&pktinfo->ipi6_addr, ifp, NULL);
2705                         ia = in6ifa_ifpwithaddr(ifp, &pktinfo->ipi6_addr);
2706                         if (ia == NULL)
2707                                 return (EADDRNOTAVAIL);
2708                         ifa_free(&ia->ia_ifa);
2709                 }
2710                 /*
2711                  * We store the address anyway, and let in6_selectsrc()
2712                  * validate the specified address.  This is because ipi6_addr
2713                  * may not have enough information about its scope zone, and
2714                  * we may need additional information (such as outgoing
2715                  * interface or the scope zone of a destination address) to
2716                  * disambiguate the scope.
2717                  * XXX: the delay of the validation may confuse the
2718                  * application when it is used as a sticky option.
2719                  */
2720                 if (opt->ip6po_pktinfo == NULL) {
2721                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2722                             M_IP6OPT, M_NOWAIT);
2723                         if (opt->ip6po_pktinfo == NULL)
2724                                 return (ENOBUFS);
2725                 }
2726                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2727                 break;
2728         }
2729
2730         case IPV6_2292HOPLIMIT:
2731         case IPV6_HOPLIMIT:
2732         {
2733                 int *hlimp;
2734
2735                 /*
2736                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2737                  * to simplify the ordering among hoplimit options.
2738                  */
2739                 if (optname == IPV6_HOPLIMIT && sticky)
2740                         return (ENOPROTOOPT);
2741
2742                 if (len != sizeof(int))
2743                         return (EINVAL);
2744                 hlimp = (int *)buf;
2745                 if (*hlimp < -1 || *hlimp > 255)
2746                         return (EINVAL);
2747
2748                 opt->ip6po_hlim = *hlimp;
2749                 break;
2750         }
2751
2752         case IPV6_TCLASS:
2753         {
2754                 int tclass;
2755
2756                 if (len != sizeof(int))
2757                         return (EINVAL);
2758                 tclass = *(int *)buf;
2759                 if (tclass < -1 || tclass > 255)
2760                         return (EINVAL);
2761
2762                 opt->ip6po_tclass = tclass;
2763                 break;
2764         }
2765
2766         case IPV6_2292NEXTHOP:
2767         case IPV6_NEXTHOP:
2768                 if (cred != NULL) {
2769                         error = priv_check_cred(cred,
2770                             PRIV_NETINET_SETHDROPTS, 0);
2771                         if (error)
2772                                 return (error);
2773                 }
2774
2775                 if (len == 0) { /* just remove the option */
2776                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2777                         break;
2778                 }
2779
2780                 /* check if cmsg_len is large enough for sa_len */
2781                 if (len < sizeof(struct sockaddr) || len < *buf)
2782                         return (EINVAL);
2783
2784                 switch (((struct sockaddr *)buf)->sa_family) {
2785                 case AF_INET6:
2786                 {
2787                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2788                         int error;
2789
2790                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2791                                 return (EINVAL);
2792
2793                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
2794                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
2795                                 return (EINVAL);
2796                         }
2797                         if ((error = sa6_embedscope(sa6, V_ip6_use_defzone))
2798                             != 0) {
2799                                 return (error);
2800                         }
2801                         break;
2802                 }
2803                 case AF_LINK:   /* should eventually be supported */
2804                 default:
2805                         return (EAFNOSUPPORT);
2806                 }
2807
2808                 /* turn off the previous option, then set the new option. */
2809                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
2810                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
2811                 if (opt->ip6po_nexthop == NULL)
2812                         return (ENOBUFS);
2813                 bcopy(buf, opt->ip6po_nexthop, *buf);
2814                 break;
2815
2816         case IPV6_2292HOPOPTS:
2817         case IPV6_HOPOPTS:
2818         {
2819                 struct ip6_hbh *hbh;
2820                 int hbhlen;
2821
2822                 /*
2823                  * XXX: We don't allow a non-privileged user to set ANY HbH
2824                  * options, since per-option restriction has too much
2825                  * overhead.
2826                  */
2827                 if (cred != NULL) {
2828                         error = priv_check_cred(cred,
2829                             PRIV_NETINET_SETHDROPTS, 0);
2830                         if (error)
2831                                 return (error);
2832                 }
2833
2834                 if (len == 0) {
2835                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
2836                         break;  /* just remove the option */
2837                 }
2838
2839                 /* message length validation */
2840                 if (len < sizeof(struct ip6_hbh))
2841                         return (EINVAL);
2842                 hbh = (struct ip6_hbh *)buf;
2843                 hbhlen = (hbh->ip6h_len + 1) << 3;
2844                 if (len != hbhlen)
2845                         return (EINVAL);
2846
2847                 /* turn off the previous option, then set the new option. */
2848                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
2849                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
2850                 if (opt->ip6po_hbh == NULL)
2851                         return (ENOBUFS);
2852                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
2853
2854                 break;
2855         }
2856
2857         case IPV6_2292DSTOPTS:
2858         case IPV6_DSTOPTS:
2859         case IPV6_RTHDRDSTOPTS:
2860         {
2861                 struct ip6_dest *dest, **newdest = NULL;
2862                 int destlen;
2863
2864                 if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
2865                         error = priv_check_cred(cred,
2866                             PRIV_NETINET_SETHDROPTS, 0);
2867                         if (error)
2868                                 return (error);
2869                 }
2870
2871                 if (len == 0) {
2872                         ip6_clearpktopts(opt, optname);
2873                         break;  /* just remove the option */
2874                 }
2875
2876                 /* message length validation */
2877                 if (len < sizeof(struct ip6_dest))
2878                         return (EINVAL);
2879                 dest = (struct ip6_dest *)buf;
2880                 destlen = (dest->ip6d_len + 1) << 3;
2881                 if (len != destlen)
2882                         return (EINVAL);
2883
2884                 /*
2885                  * Determine the position that the destination options header
2886                  * should be inserted; before or after the routing header.
2887                  */
2888                 switch (optname) {
2889                 case IPV6_2292DSTOPTS:
2890                         /*
2891                          * The old advacned API is ambiguous on this point.
2892                          * Our approach is to determine the position based
2893                          * according to the existence of a routing header.
2894                          * Note, however, that this depends on the order of the
2895                          * extension headers in the ancillary data; the 1st
2896                          * part of the destination options header must appear
2897                          * before the routing header in the ancillary data,
2898                          * too.
2899                          * RFC3542 solved the ambiguity by introducing
2900                          * separate ancillary data or option types.
2901                          */
2902                         if (opt->ip6po_rthdr == NULL)
2903                                 newdest = &opt->ip6po_dest1;
2904                         else
2905                                 newdest = &opt->ip6po_dest2;
2906                         break;
2907                 case IPV6_RTHDRDSTOPTS:
2908                         newdest = &opt->ip6po_dest1;
2909                         break;
2910                 case IPV6_DSTOPTS:
2911                         newdest = &opt->ip6po_dest2;
2912                         break;
2913                 }
2914
2915                 /* turn off the previous option, then set the new option. */
2916                 ip6_clearpktopts(opt, optname);
2917                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
2918                 if (*newdest == NULL)
2919                         return (ENOBUFS);
2920                 bcopy(dest, *newdest, destlen);
2921
2922                 break;
2923         }
2924
2925         case IPV6_2292RTHDR:
2926         case IPV6_RTHDR:
2927         {
2928                 struct ip6_rthdr *rth;
2929                 int rthlen;
2930
2931                 if (len == 0) {
2932                         ip6_clearpktopts(opt, IPV6_RTHDR);
2933                         break;  /* just remove the option */
2934                 }
2935
2936                 /* message length validation */
2937                 if (len < sizeof(struct ip6_rthdr))
2938                         return (EINVAL);
2939                 rth = (struct ip6_rthdr *)buf;
2940                 rthlen = (rth->ip6r_len + 1) << 3;
2941                 if (len != rthlen)
2942                         return (EINVAL);
2943
2944                 switch (rth->ip6r_type) {
2945                 case IPV6_RTHDR_TYPE_0:
2946                         if (rth->ip6r_len == 0) /* must contain one addr */
2947                                 return (EINVAL);
2948                         if (rth->ip6r_len % 2) /* length must be even */
2949                                 return (EINVAL);
2950                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
2951                                 return (EINVAL);
2952                         break;
2953                 default:
2954                         return (EINVAL);        /* not supported */
2955                 }
2956
2957                 /* turn off the previous option */
2958                 ip6_clearpktopts(opt, IPV6_RTHDR);
2959                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
2960                 if (opt->ip6po_rthdr == NULL)
2961                         return (ENOBUFS);
2962                 bcopy(rth, opt->ip6po_rthdr, rthlen);
2963
2964                 break;
2965         }
2966
2967         case IPV6_USE_MIN_MTU:
2968                 if (len != sizeof(int))
2969                         return (EINVAL);
2970                 minmtupolicy = *(int *)buf;
2971                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
2972                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
2973                     minmtupolicy != IP6PO_MINMTU_ALL) {
2974                         return (EINVAL);
2975                 }
2976                 opt->ip6po_minmtu = minmtupolicy;
2977                 break;
2978
2979         case IPV6_DONTFRAG:
2980                 if (len != sizeof(int))
2981                         return (EINVAL);
2982
2983                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
2984                         /*
2985                          * we ignore this option for TCP sockets.
2986                          * (RFC3542 leaves this case unspecified.)
2987                          */
2988                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
2989                 } else
2990                         opt->ip6po_flags |= IP6PO_DONTFRAG;
2991                 break;
2992
2993         case IPV6_PREFER_TEMPADDR:
2994                 if (len != sizeof(int))
2995                         return (EINVAL);
2996                 preftemp = *(int *)buf;
2997                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
2998                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
2999                     preftemp != IP6PO_TEMPADDR_PREFER) {
3000                         return (EINVAL);
3001                 }
3002                 opt->ip6po_prefer_tempaddr = preftemp;
3003                 break;
3004
3005         default:
3006                 return (ENOPROTOOPT);
3007         } /* end of switch */
3008
3009         return (0);
3010 }
3011
3012 /*
3013  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3014  * packet to the input queue of a specified interface.  Note that this
3015  * calls the output routine of the loopback "driver", but with an interface
3016  * pointer that might NOT be &loif -- easier than replicating that code here.
3017  */
3018 void
3019 ip6_mloopback(struct ifnet *ifp, struct mbuf *m)
3020 {
3021         struct mbuf *copym;
3022         struct ip6_hdr *ip6;
3023
3024         copym = m_copym(m, 0, M_COPYALL, M_NOWAIT);
3025         if (copym == NULL)
3026                 return;
3027
3028         /*
3029          * Make sure to deep-copy IPv6 header portion in case the data
3030          * is in an mbuf cluster, so that we can safely override the IPv6
3031          * header portion later.
3032          */
3033         if (!M_WRITABLE(copym) ||
3034             copym->m_len < sizeof(struct ip6_hdr)) {
3035                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3036                 if (copym == NULL)
3037                         return;
3038         }
3039         ip6 = mtod(copym, struct ip6_hdr *);
3040         /*
3041          * clear embedded scope identifiers if necessary.
3042          * in6_clearscope will touch the addresses only when necessary.
3043          */
3044         in6_clearscope(&ip6->ip6_src);
3045         in6_clearscope(&ip6->ip6_dst);
3046         if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
3047                 copym->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 |
3048                     CSUM_PSEUDO_HDR;
3049                 copym->m_pkthdr.csum_data = 0xffff;
3050         }
3051         if_simloop(ifp, copym, AF_INET6, 0);
3052 }
3053
3054 /*
3055  * Chop IPv6 header off from the payload.
3056  */
3057 static int
3058 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3059 {
3060         struct mbuf *mh;
3061         struct ip6_hdr *ip6;
3062
3063         ip6 = mtod(m, struct ip6_hdr *);
3064         if (m->m_len > sizeof(*ip6)) {
3065                 mh = m_gethdr(M_NOWAIT, MT_DATA);
3066                 if (mh == NULL) {
3067                         m_freem(m);
3068                         return ENOBUFS;
3069                 }
3070                 m_move_pkthdr(mh, m);
3071                 M_ALIGN(mh, sizeof(*ip6));
3072                 m->m_len -= sizeof(*ip6);
3073                 m->m_data += sizeof(*ip6);
3074                 mh->m_next = m;
3075                 m = mh;
3076                 m->m_len = sizeof(*ip6);
3077                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3078         }
3079         exthdrs->ip6e_ip6 = m;
3080         return 0;
3081 }
3082
3083 /*
3084  * Compute IPv6 extension header length.
3085  */
3086 int
3087 ip6_optlen(struct inpcb *in6p)
3088 {
3089         int len;
3090
3091         if (!in6p->in6p_outputopts)
3092                 return 0;
3093
3094         len = 0;
3095 #define elen(x) \
3096     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3097
3098         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3099         if (in6p->in6p_outputopts->ip6po_rthdr)
3100                 /* dest1 is valid with rthdr only */
3101                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3102         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3103         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3104         return len;
3105 #undef elen
3106 }