sys/netinet6/ip6_output.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1990, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipsec.h"
  69
  70 #include <sys/param.h>
  71 #include <sys/malloc.h>
  72 #include <sys/mbuf.h>
  73 #include <sys/proc.h>
  74 #include <sys/errno.h>
  75 #include <sys/priv.h>
  76 #include <sys/protosw.h>
  77 #include <sys/socket.h>
  78 #include <sys/socketvar.h>
  79 #include <sys/kernel.h>
  80
  81 #include <net/if.h>
  82 #include <net/netisr.h>
  83 #include <net/route.h>
  84 #include <net/pfil.h>
  85
  86 #include <netinet/in.h>
  87 #include <netinet/in_var.h>
  88 #include <netinet6/in6_var.h>
  89 #include <netinet/ip6.h>
  90 #include <netinet/icmp6.h>
  91 #include <netinet6/ip6_var.h>
  92 #include <netinet/in_pcb.h>
  93 #include <netinet/tcp_var.h>
  94 #include <netinet6/nd6.h>
  95
  96 #ifdef IPSEC
  97 #include <netipsec/ipsec.h>
  98 #include <netipsec/ipsec6.h>
  99 #include <netipsec/key.h>
 100 #include <netinet6/ip6_ipsec.h>
 101 #endif /* IPSEC */
 102
 103 #include <netinet6/ip6protosw.h>
 104 #include <netinet6/scope6_var.h>
 105
 106 static MALLOC_DEFINE(M_IP6MOPTS, "ip6_moptions", "internet multicast options");
 107
 108 struct ip6_exthdrs {
 109         struct mbuf *ip6e_ip6;
 110         struct mbuf *ip6e_hbh;
 111         struct mbuf *ip6e_dest1;
 112         struct mbuf *ip6e_rthdr;
 113         struct mbuf *ip6e_dest2;
 114 };
 115
 116 static int ip6_pcbopt __P((int, u_char *, int, struct ip6_pktopts **,
 117                            int, int));
 118 static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
 119         struct socket *, struct sockopt *));
 120 static int ip6_getpcbopt __P((struct ip6_pktopts *, int, struct sockopt *));
 121 static int ip6_setpktopt __P((int, u_char *, int, struct ip6_pktopts *, int,
 122         int, int, int));
 123
 124 static int ip6_setmoptions __P((int, struct ip6_moptions **, struct mbuf *));
 125 static int ip6_getmoptions __P((int, struct ip6_moptions *, struct mbuf **));
 126 static int ip6_copyexthdr __P((struct mbuf **, caddr_t, int));
 127 static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
 128         struct ip6_frag **));
 129 static int ip6_insert_jumboopt __P((struct ip6_exthdrs *, u_int32_t));
 130 static int ip6_splithdr __P((struct mbuf *, struct ip6_exthdrs *));
 131 static int ip6_getpmtu __P((struct route_in6 *, struct route_in6 *,
 132         struct ifnet *, struct in6_addr *, u_long *, int *));
 133 static int copypktopts __P((struct ip6_pktopts *, struct ip6_pktopts *, int));
 134
 135
 136 /*
 137  * Make an extension header from option data.  hp is the source, and
 138  * mp is the destination.
 139  */
 140 #define MAKE_EXTHDR(hp, mp)                                             \
 141     do {                                                                \
 142         if (hp) {                                                       \
 143                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 144                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 145                     ((eh)->ip6e_len + 1) << 3);                         \
 146                 if (error)                                              \
 147                         goto freehdrs;                                  \
 148         }                                                               \
 149     } while (/*CONSTCOND*/ 0)
 150
 151 /*
 152  * Form a chain of extension headers.
 153  * m is the extension header mbuf
 154  * mp is the previous mbuf in the chain
 155  * p is the next header
 156  * i is the type of option.
 157  */
 158 #define MAKE_CHAIN(m, mp, p, i)\
 159     do {\
 160         if (m) {\
 161                 if (!hdrsplit) \
 162                         panic("assumption failed: hdr not split"); \
 163                 *mtod((m), u_char *) = *(p);\
 164                 *(p) = (i);\
 165                 p = mtod((m), u_char *);\
 166                 (m)->m_next = (mp)->m_next;\
 167                 (mp)->m_next = (m);\
 168                 (mp) = (m);\
 169         }\
 170     } while (/*CONSTCOND*/ 0)
 171
 172 /*
 173  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 174  * header (with pri, len, nxt, hlim, src, dst).
 175  * This function may modify ver and hlim only.
 176  * The mbuf chain containing the packet will be freed.
 177  * The mbuf opt, if present, will not be freed.
 178  *
 179  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
 180  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 181  * which is rt_rmx.rmx_mtu.
 182  *
 183  * ifpp - XXX: just for statistics
 184  */
 185 int
 186 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 187     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 188     struct ifnet **ifpp, struct inpcb *inp)
 189 {
 190         struct ip6_hdr *ip6, *mhip6;
 191         struct ifnet *ifp, *origifp;
 192         struct mbuf *m = m0;
 193         struct mbuf *mprev = NULL;
 194         int hlen, tlen, len, off;
 195         struct route_in6 ip6route;
 196         struct rtentry *rt = NULL;
 197         struct sockaddr_in6 *dst, src_sa, dst_sa;
 198         struct in6_addr odst;
 199         int error = 0;
 200         struct in6_ifaddr *ia = NULL;
 201         u_long mtu;
 202         int alwaysfrag, dontfrag;
 203         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 204         struct ip6_exthdrs exthdrs;
 205         struct in6_addr finaldst, src0, dst0;
 206         u_int32_t zone;
 207         struct route_in6 *ro_pmtu = NULL;
 208         int hdrsplit = 0;
 209         int needipsec = 0;
 210 #ifdef IPSEC
 211         struct ipsec_output_state state;
 212         struct ip6_rthdr *rh = NULL;
 213         int needipsectun = 0;
 214         int segleft_org = 0;
 215         struct secpolicy *sp = NULL;
 216 #endif /* IPSEC */
 217
 218         ip6 = mtod(m, struct ip6_hdr *);
 219         if (ip6 == NULL) {
 220                 printf ("ip6 is NULL");
 221                 goto bad;
 222         }
 223
 224         finaldst = ip6->ip6_dst;
 225
 226         bzero(&exthdrs, sizeof(exthdrs));
 227
 228         if (opt) {
 229                 /* Hop-by-Hop options header */
 230                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 231                 /* Destination options header(1st part) */
 232                 if (opt->ip6po_rthdr) {
 233                         /*
 234                          * Destination options header(1st part)
 235                          * This only makes sense with a routing header.
 236                          * See Section 9.2 of RFC 3542.
 237                          * Disabling this part just for MIP6 convenience is
 238                          * a bad idea.  We need to think carefully about a
 239                          * way to make the advanced API coexist with MIP6
 240                          * options, which might automatically be inserted in
 241                          * the kernel.
 242                          */
 243                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 244                 }
 245                 /* Routing header */
 246                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 247                 /* Destination options header(2nd part) */
 248                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 249         }
 250
 251         /*
 252          * IPSec checking which handles several cases.
 253          * FAST IPSEC: We re-injected the packet.
 254          */
 255 #ifdef IPSEC
 256         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
 257         {
 258         case 1:                 /* Bad packet */
 259                 goto freehdrs;
 260         case -1:                /* Do IPSec */
 261                 needipsec = 1;
 262         case 0:                 /* No IPSec */
 263         default:
 264                 break;
 265         }
 266 #endif /* IPSEC */
 267
 268         /*
 269          * Calculate the total length of the extension header chain.
 270          * Keep the length of the unfragmentable part for fragmentation.
 271          */
 272         optlen = 0;
 273         if (exthdrs.ip6e_hbh)
 274                 optlen += exthdrs.ip6e_hbh->m_len;
 275         if (exthdrs.ip6e_dest1)
 276                 optlen += exthdrs.ip6e_dest1->m_len;
 277         if (exthdrs.ip6e_rthdr)
 278                 optlen += exthdrs.ip6e_rthdr->m_len;
 279         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 280
 281         /* NOTE: we don't add AH/ESP length here. do that later. */
 282         if (exthdrs.ip6e_dest2)
 283                 optlen += exthdrs.ip6e_dest2->m_len;
 284
 285         /*
 286          * If we need IPsec, or there is at least one extension header,
 287          * separate IP6 header from the payload.
 288          */
 289         if ((needipsec || optlen) && !hdrsplit) {
 290                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 291                         m = NULL;
 292                         goto freehdrs;
 293                 }
 294                 m = exthdrs.ip6e_ip6;
 295                 hdrsplit++;
 296         }
 297
 298         /* adjust pointer */
 299         ip6 = mtod(m, struct ip6_hdr *);
 300
 301         /* adjust mbuf packet header length */
 302         m->m_pkthdr.len += optlen;
 303         plen = m->m_pkthdr.len - sizeof(*ip6);
 304
 305         /* If this is a jumbo payload, insert a jumbo payload option. */
 306         if (plen > IPV6_MAXPACKET) {
 307                 if (!hdrsplit) {
 308                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 309                                 m = NULL;
 310                                 goto freehdrs;
 311                         }
 312                         m = exthdrs.ip6e_ip6;
 313                         hdrsplit++;
 314                 }
 315                 /* adjust pointer */
 316                 ip6 = mtod(m, struct ip6_hdr *);
 317                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 318                         goto freehdrs;
 319                 ip6->ip6_plen = 0;
 320         } else
 321                 ip6->ip6_plen = htons(plen);
 322
 323         /*
 324          * Concatenate headers and fill in next header fields.
 325          * Here we have, on "m"
 326          *      IPv6 payload
 327          * and we insert headers accordingly.  Finally, we should be getting:
 328          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 329          *
 330          * during the header composing process, "m" points to IPv6 header.
 331          * "mprev" points to an extension header prior to esp.
 332          */
 333         u_char *nexthdrp = &ip6->ip6_nxt;
 334         mprev = m;
 335
 336         /*
 337          * we treat dest2 specially.  this makes IPsec processing
 338          * much easier.  the goal here is to make mprev point the
 339          * mbuf prior to dest2.
 340          *
 341          * result: IPv6 dest2 payload
 342          * m and mprev will point to IPv6 header.
 343          */
 344         if (exthdrs.ip6e_dest2) {
 345                 if (!hdrsplit)
 346                         panic("assumption failed: hdr not split");
 347                 exthdrs.ip6e_dest2->m_next = m->m_next;
 348                 m->m_next = exthdrs.ip6e_dest2;
 349                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 350                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 351         }
 352
 353         /*
 354          * result: IPv6 hbh dest1 rthdr dest2 payload
 355          * m will point to IPv6 header.  mprev will point to the
 356          * extension header prior to dest2 (rthdr in the above case).
 357          */
 358         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 359         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 360                    IPPROTO_DSTOPTS);
 361         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 362                    IPPROTO_ROUTING);
 363
 364 #ifdef IPSEC
 365         if (!needipsec)
 366                 goto skip_ipsec2;
 367
 368         /*
 369          * pointers after IPsec headers are not valid any more.
 370          * other pointers need a great care too.
 371          * (IPsec routines should not mangle mbufs prior to AH/ESP)
 372          */
 373         exthdrs.ip6e_dest2 = NULL;
 374
 375         if (exthdrs.ip6e_rthdr) {
 376                 rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
 377                 segleft_org = rh->ip6r_segleft;
 378                 rh->ip6r_segleft = 0;
 379         }
 380
 381         bzero(&state, sizeof(state));
 382         state.m = m;
 383         error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
 384                                     &needipsectun);
 385         m = state.m;
 386         if (error) {
 387                 /* mbuf is already reclaimed in ipsec6_output_trans. */
 388                 m = NULL;
 389                 switch (error) {
 390                 case EHOSTUNREACH:
 391                 case ENETUNREACH:
 392                 case EMSGSIZE:
 393                 case ENOBUFS:
 394                 case ENOMEM:
 395                         break;
 396                 default:
 397                         printf("ip6_output (ipsec): error code %d\n", error);
 398                         /* FALLTHROUGH */
 399                 case ENOENT:
 400                         /* don't show these error codes to the user */
 401                         error = 0;
 402                         break;
 403                 }
 404                 goto bad;
 405         } else if (!needipsectun) {
 406                 /*
 407                  * In the FAST IPSec case we have already
 408                  * re-injected the packet and it has been freed
 409                  * by the ipsec_done() function.  So, just clean
 410                  * up after ourselves.
 411                  */
 412                 m = NULL;
 413                 goto done;
 414         }
 415         if (exthdrs.ip6e_rthdr) {
 416                 /* ah6_output doesn't modify mbuf chain */
 417                 rh->ip6r_segleft = segleft_org;
 418         }
 419 skip_ipsec2:;
 420 #endif /* IPSEC */
 421
 422         /*
 423          * If there is a routing header, replace the destination address field
 424          * with the first hop of the routing header.
 425          */
 426         if (exthdrs.ip6e_rthdr) {
 427                 struct ip6_rthdr *rh =
 428                         (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
 429                                                   struct ip6_rthdr *));
 430                 struct ip6_rthdr0 *rh0;
 431                 struct in6_addr *addr;
 432                 struct sockaddr_in6 sa;
 433
 434                 switch (rh->ip6r_type) {
 435                 case IPV6_RTHDR_TYPE_0:
 436                          rh0 = (struct ip6_rthdr0 *)rh;
 437                          addr = (struct in6_addr *)(rh0 + 1);
 438
 439                          /*
 440                           * construct a sockaddr_in6 form of
 441                           * the first hop.
 442                           *
 443                           * XXX: we may not have enough
 444                           * information about its scope zone;
 445                           * there is no standard API to pass
 446                           * the information from the
 447                           * application.
 448                           */
 449                          bzero(&sa, sizeof(sa));
 450                          sa.sin6_family = AF_INET6;
 451                          sa.sin6_len = sizeof(sa);
 452                          sa.sin6_addr = addr[0];
 453                          if ((error = sa6_embedscope(&sa,
 454                              ip6_use_defzone)) != 0) {
 455                                  goto bad;
 456                          }
 457                          ip6->ip6_dst = sa.sin6_addr;
 458                          bcopy(&addr[1], &addr[0], sizeof(struct in6_addr)
 459                              * (rh0->ip6r0_segleft - 1));
 460                          addr[rh0->ip6r0_segleft - 1] = finaldst;
 461                          /* XXX */
 462                          in6_clearscope(addr + rh0->ip6r0_segleft - 1);
 463                          break;
 464                 default:        /* is it possible? */
 465                          error = EINVAL;
 466                          goto bad;
 467                 }
 468         }
 469
 470         /* Source address validation */
 471         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 472             (flags & IPV6_UNSPECSRC) == 0) {
 473                 error = EOPNOTSUPP;
 474                 ip6stat.ip6s_badscope++;
 475                 goto bad;
 476         }
 477         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 478                 error = EOPNOTSUPP;
 479                 ip6stat.ip6s_badscope++;
 480                 goto bad;
 481         }
 482
 483         ip6stat.ip6s_localout++;
 484
 485         /*
 486          * Route packet.
 487          */
 488         if (ro == 0) {
 489                 ro = &ip6route;
 490                 bzero((caddr_t)ro, sizeof(*ro));
 491         }
 492         ro_pmtu = ro;
 493         if (opt && opt->ip6po_rthdr)
 494                 ro = &opt->ip6po_route;
 495         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 496
 497 again:
 498         /*
 499          * if specified, try to fill in the traffic class field.
 500          * do not override if a non-zero value is already set.
 501          * we check the diffserv field and the ecn field separately.
 502          */
 503         if (opt && opt->ip6po_tclass >= 0) {
 504                 int mask = 0;
 505
 506                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 507                         mask |= 0xfc;
 508                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 509                         mask |= 0x03;
 510                 if (mask != 0)
 511                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 512         }
 513
 514         /* fill in or override the hop limit field, if necessary. */
 515         if (opt && opt->ip6po_hlim != -1)
 516                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 517         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 518                 if (im6o != NULL)
 519                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 520                 else
 521                         ip6->ip6_hlim = ip6_defmcasthlim;
 522         }
 523
 524 #ifdef IPSEC
 525         /*
 526          * We may re-inject packets into the stack here.
 527          */
 528         if (needipsec && needipsectun) {
 529                 struct ipsec_output_state state;
 530
 531                 /*
 532                  * All the extension headers will become inaccessible
 533                  * (since they can be encrypted).
 534                  * Don't panic, we need no more updates to extension headers
 535                  * on inner IPv6 packet (since they are now encapsulated).
 536                  *
 537                  * IPv6 [ESP|AH] IPv6 [extension headers] payload
 538                  */
 539                 bzero(&exthdrs, sizeof(exthdrs));
 540                 exthdrs.ip6e_ip6 = m;
 541
 542                 bzero(&state, sizeof(state));
 543                 state.m = m;
 544                 state.ro = (struct route *)ro;
 545                 state.dst = (struct sockaddr *)dst;
 546
 547                 error = ipsec6_output_tunnel(&state, sp, flags);
 548
 549                 m = state.m;
 550                 ro = (struct route_in6 *)state.ro;
 551                 dst = (struct sockaddr_in6 *)state.dst;
 552                 if (error) {
 553                         /* mbuf is already reclaimed in ipsec6_output_tunnel. */
 554                         m0 = m = NULL;
 555                         m = NULL;
 556                         switch (error) {
 557                         case EHOSTUNREACH:
 558                         case ENETUNREACH:
 559                         case EMSGSIZE:
 560                         case ENOBUFS:
 561                         case ENOMEM:
 562                                 break;
 563                         default:
 564                                 printf("ip6_output (ipsec): error code %d\n", error);
 565                                 /* FALLTHROUGH */
 566                         case ENOENT:
 567                                 /* don't show these error codes to the user */
 568                                 error = 0;
 569                                 break;
 570                         }
 571                         goto bad;
 572                 } else {
 573                         /*
 574                          * In the FAST IPSec case we have already
 575                          * re-injected the packet and it has been freed
 576                          * by the ipsec_done() function.  So, just clean
 577                          * up after ourselves.
 578                          */
 579                         m = NULL;
 580                         goto done;
 581                 }
 582
 583                 exthdrs.ip6e_ip6 = m;
 584         }
 585 #endif /* IPSEC */
 586
 587         /* adjust pointer */
 588         ip6 = mtod(m, struct ip6_hdr *);
 589
 590         bzero(&dst_sa, sizeof(dst_sa));
 591         dst_sa.sin6_family = AF_INET6;
 592         dst_sa.sin6_len = sizeof(dst_sa);
 593         dst_sa.sin6_addr = ip6->ip6_dst;
 594         if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
 595             &ifp, &rt, 0)) != 0) {
 596                 switch (error) {
 597                 case EHOSTUNREACH:
 598                         ip6stat.ip6s_noroute++;
 599                         break;
 600                 case EADDRNOTAVAIL:
 601                 default:
 602                         break; /* XXX statistics? */
 603                 }
 604                 if (ifp != NULL)
 605                         in6_ifstat_inc(ifp, ifs6_out_discard);
 606                 goto bad;
 607         }
 608         if (rt == NULL) {
 609                 /*
 610                  * If in6_selectroute() does not return a route entry,
 611                  * dst may not have been updated.
 612                  */
 613                 *dst = dst_sa;  /* XXX */
 614         }
 615
 616         /*
 617          * then rt (for unicast) and ifp must be non-NULL valid values.
 618          */
 619         if ((flags & IPV6_FORWARDING) == 0) {
 620                 /* XXX: the FORWARDING flag can be set for mrouting. */
 621                 in6_ifstat_inc(ifp, ifs6_out_request);
 622         }
 623         if (rt != NULL) {
 624                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 625                 rt->rt_use++;
 626         }
 627
 628         /*
 629          * The outgoing interface must be in the zone of source and
 630          * destination addresses.  We should use ia_ifp to support the
 631          * case of sending packets to an address of our own.
 632          */
 633         if (ia != NULL && ia->ia_ifp)
 634                 origifp = ia->ia_ifp;
 635         else
 636                 origifp = ifp;
 637
 638         src0 = ip6->ip6_src;
 639         if (in6_setscope(&src0, origifp, &zone))
 640                 goto badscope;
 641         bzero(&src_sa, sizeof(src_sa));
 642         src_sa.sin6_family = AF_INET6;
 643         src_sa.sin6_len = sizeof(src_sa);
 644         src_sa.sin6_addr = ip6->ip6_src;
 645         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 646                 goto badscope;
 647
 648         dst0 = ip6->ip6_dst;
 649         if (in6_setscope(&dst0, origifp, &zone))
 650                 goto badscope;
 651         /* re-initialize to be sure */
 652         bzero(&dst_sa, sizeof(dst_sa));
 653         dst_sa.sin6_family = AF_INET6;
 654         dst_sa.sin6_len = sizeof(dst_sa);
 655         dst_sa.sin6_addr = ip6->ip6_dst;
 656         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 657                 goto badscope;
 658         }
 659
 660         /* scope check is done. */
 661         goto routefound;
 662
 663   badscope:
 664         ip6stat.ip6s_badscope++;
 665         in6_ifstat_inc(origifp, ifs6_out_discard);
 666         if (error == 0)
 667                 error = EHOSTUNREACH; /* XXX */
 668         goto bad;
 669
 670   routefound:
 671         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 672                 if (opt && opt->ip6po_nextroute.ro_rt) {
 673                         /*
 674                          * The nexthop is explicitly specified by the
 675                          * application.  We assume the next hop is an IPv6
 676                          * address.
 677                          */
 678                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 679                 }
 680                 else if ((rt->rt_flags & RTF_GATEWAY))
 681                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 682         }
 683
 684         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 685                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 686         } else {
 687                 struct  in6_multi *in6m;
 688
 689                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 690
 691                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 692
 693                 /*
 694                  * Confirm that the outgoing interface supports multicast.
 695                  */
 696                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 697                         ip6stat.ip6s_noroute++;
 698                         in6_ifstat_inc(ifp, ifs6_out_discard);
 699                         error = ENETUNREACH;
 700                         goto bad;
 701                 }
 702                 IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
 703                 if (in6m != NULL &&
 704                    (im6o == NULL || im6o->im6o_multicast_loop)) {
 705                         /*
 706                          * If we belong to the destination multicast group
 707                          * on the outgoing interface, and the caller did not
 708                          * forbid loopback, loop back a copy.
 709                          */
 710                         ip6_mloopback(ifp, m, dst);
 711                 } else {
 712                         /*
 713                          * If we are acting as a multicast router, perform
 714                          * multicast forwarding as if the packet had just
 715                          * arrived on the interface to which we are about
 716                          * to send.  The multicast forwarding function
 717                          * recursively calls this function, using the
 718                          * IPV6_FORWARDING flag to prevent infinite recursion.
 719                          *
 720                          * Multicasts that are looped back by ip6_mloopback(),
 721                          * above, will be forwarded by the ip6_input() routine,
 722                          * if necessary.
 723                          */
 724                         if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 725                                 /*
 726                                  * XXX: ip6_mforward expects that rcvif is NULL
 727                                  * when it is called from the originating path.
 728                                  * However, it is not always the case, since
 729                                  * some versions of MGETHDR() does not
 730                                  * initialize the field.
 731                                  */
 732                                 m->m_pkthdr.rcvif = NULL;
 733                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 734                                         m_freem(m);
 735                                         goto done;
 736                                 }
 737                         }
 738                 }
 739                 /*
 740                  * Multicasts with a hoplimit of zero may be looped back,
 741                  * above, but must not be transmitted on a network.
 742                  * Also, multicasts addressed to the loopback interface
 743                  * are not sent -- the above call to ip6_mloopback() will
 744                  * loop back a copy if this host actually belongs to the
 745                  * destination group on the loopback interface.
 746                  */
 747                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 748                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 749                         m_freem(m);
 750                         goto done;
 751                 }
 752         }
 753
 754         /*
 755          * Fill the outgoing inteface to tell the upper layer
 756          * to increment per-interface statistics.
 757          */
 758         if (ifpp)
 759                 *ifpp = ifp;
 760
 761         /* Determine path MTU. */
 762         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
 763             &alwaysfrag)) != 0)
 764                 goto bad;
 765
 766         /*
 767          * The caller of this function may specify to use the minimum MTU
 768          * in some cases.
 769          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 770          * setting.  The logic is a bit complicated; by default, unicast
 771          * packets will follow path MTU while multicast packets will be sent at
 772          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 773          * including unicast ones will be sent at the minimum MTU.  Multicast
 774          * packets will always be sent at the minimum MTU unless
 775          * IP6PO_MINMTU_DISABLE is explicitly specified.
 776          * See RFC 3542 for more details.
 777          */
 778         if (mtu > IPV6_MMTU) {
 779                 if ((flags & IPV6_MINMTU))
 780                         mtu = IPV6_MMTU;
 781                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 782                         mtu = IPV6_MMTU;
 783                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 784                          (opt == NULL ||
 785                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 786                         mtu = IPV6_MMTU;
 787                 }
 788         }
 789
 790         /*
 791          * clear embedded scope identifiers if necessary.
 792          * in6_clearscope will touch the addresses only when necessary.
 793          */
 794         in6_clearscope(&ip6->ip6_src);
 795         in6_clearscope(&ip6->ip6_dst);
 796
 797         /*
 798          * If the outgoing packet contains a hop-by-hop options header,
 799          * it must be examined and processed even by the source node.
 800          * (RFC 2460, section 4.)
 801          */
 802         if (exthdrs.ip6e_hbh) {
 803                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 804                 u_int32_t dummy; /* XXX unused */
 805                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 806
 807 #ifdef DIAGNOSTIC
 808                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 809                         panic("ip6e_hbh is not continuous");
 810 #endif
 811                 /*
 812                  *  XXX: if we have to send an ICMPv6 error to the sender,
 813                  *       we need the M_LOOP flag since icmp6_error() expects
 814                  *       the IPv6 and the hop-by-hop options header are
 815                  *       continuous unless the flag is set.
 816                  */
 817                 m->m_flags |= M_LOOP;
 818                 m->m_pkthdr.rcvif = ifp;
 819                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 820                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 821                     &dummy, &plen) < 0) {
 822                         /* m was already freed at this point */
 823                         error = EINVAL;/* better error? */
 824                         goto done;
 825                 }
 826                 m->m_flags &= ~M_LOOP; /* XXX */
 827                 m->m_pkthdr.rcvif = NULL;
 828         }
 829
 830         /* Jump over all PFIL processing if hooks are not active. */
 831         if (!PFIL_HOOKED(&inet6_pfil_hook))
 832                 goto passout;
 833
 834         odst = ip6->ip6_dst;
 835         /* Run through list of hooks for output packets. */
 836         error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 837         if (error != 0 || m == NULL)
 838                 goto done;
 839         ip6 = mtod(m, struct ip6_hdr *);
 840
 841         /* See if destination IP address was changed by packet filter. */
 842         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 843                 m->m_flags |= M_SKIP_FIREWALL;
 844                 /* If destination is now ourself drop to ip6_input(). */
 845                 if (in6_localaddr(&ip6->ip6_dst)) {
 846                         if (m->m_pkthdr.rcvif == NULL)
 847                                 m->m_pkthdr.rcvif = loif;
 848                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 849                                 m->m_pkthdr.csum_flags |=
 850                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 851                                 m->m_pkthdr.csum_data = 0xffff;
 852                         }
 853                         m->m_pkthdr.csum_flags |=
 854                             CSUM_IP_CHECKED | CSUM_IP_VALID;
 855                         error = netisr_queue(NETISR_IPV6, m);
 856                         goto done;
 857                 } else
 858                         goto again;     /* Redo the routing table lookup. */
 859         }
 860
 861         /* XXX: IPFIREWALL_FORWARD */
 862
 863 passout:
 864         /*
 865          * Send the packet to the outgoing interface.
 866          * If necessary, do IPv6 fragmentation before sending.
 867          *
 868          * the logic here is rather complex:
 869          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 870          * 1-a: send as is if tlen <= path mtu
 871          * 1-b: fragment if tlen > path mtu
 872          *
 873          * 2: if user asks us not to fragment (dontfrag == 1)
 874          * 2-a: send as is if tlen <= interface mtu
 875          * 2-b: error if tlen > interface mtu
 876          *
 877          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 878          *      always fragment
 879          *
 880          * 4: if dontfrag == 1 && alwaysfrag == 1
 881          *      error, as we cannot handle this conflicting request
 882          */
 883         tlen = m->m_pkthdr.len;
 884
 885         if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
 886                 dontfrag = 1;
 887         else
 888                 dontfrag = 0;
 889         if (dontfrag && alwaysfrag) {   /* case 4 */
 890                 /* conflicting request - can't transmit */
 891                 error = EMSGSIZE;
 892                 goto bad;
 893         }
 894         if (dontfrag && tlen > IN6_LINKMTU(ifp)) {      /* case 2-b */
 895                 /*
 896                  * Even if the DONTFRAG option is specified, we cannot send the
 897                  * packet when the data length is larger than the MTU of the
 898                  * outgoing interface.
 899                  * Notify the error by sending IPV6_PATHMTU ancillary data as
 900                  * well as returning an error code (the latter is not described
 901                  * in the API spec.)
 902                  */
 903                 u_int32_t mtu32;
 904                 struct ip6ctlparam ip6cp;
 905
 906                 mtu32 = (u_int32_t)mtu;
 907                 bzero(&ip6cp, sizeof(ip6cp));
 908                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
 909                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
 910                     (void *)&ip6cp);
 911
 912                 error = EMSGSIZE;
 913                 goto bad;
 914         }
 915
 916         /*
 917          * transmit packet without fragmentation
 918          */
 919         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 920                 struct in6_ifaddr *ia6;
 921
 922                 ip6 = mtod(m, struct ip6_hdr *);
 923                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 924                 if (ia6) {
 925                         /* Record statistics for this interface address. */
 926                         ia6->ia_ifa.if_opackets++;
 927                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
 928                 }
 929                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
 930                 goto done;
 931         }
 932
 933         /*
 934          * try to fragment the packet.  case 1-b and 3
 935          */
 936         if (mtu < IPV6_MMTU) {
 937                 /* path MTU cannot be less than IPV6_MMTU */
 938                 error = EMSGSIZE;
 939                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 940                 goto bad;
 941         } else if (ip6->ip6_plen == 0) {
 942                 /* jumbo payload cannot be fragmented */
 943                 error = EMSGSIZE;
 944                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 945                 goto bad;
 946         } else {
 947                 struct mbuf **mnext, *m_frgpart;
 948                 struct ip6_frag *ip6f;
 949                 u_int32_t id = htonl(ip6_randomid());
 950                 u_char nextproto;
 951
 952                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
 953
 954                 /*
 955                  * Too large for the destination or interface;
 956                  * fragment if possible.
 957                  * Must be able to put at least 8 bytes per fragment.
 958                  */
 959                 hlen = unfragpartlen;
 960                 if (mtu > IPV6_MAXPACKET)
 961                         mtu = IPV6_MAXPACKET;
 962
 963                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 964                 if (len < 8) {
 965                         error = EMSGSIZE;
 966                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
 967                         goto bad;
 968                 }
 969
 970                 /*
 971                  * Verify that we have any chance at all of being able to queue
 972                  *      the packet or packet fragments
 973                  */
 974                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
 975                     < tlen  /* - hlen */)) {
 976                         error = ENOBUFS;
 977                         ip6stat.ip6s_odropped++;
 978                         goto bad;
 979                 }
 980
 981                 mnext = &m->m_nextpkt;
 982
 983                 /*
 984                  * Change the next header field of the last header in the
 985                  * unfragmentable part.
 986                  */
 987                 if (exthdrs.ip6e_rthdr) {
 988                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
 989                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
 990                 } else if (exthdrs.ip6e_dest1) {
 991                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
 992                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
 993                 } else if (exthdrs.ip6e_hbh) {
 994                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
 995                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
 996                 } else {
 997                         nextproto = ip6->ip6_nxt;
 998                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
 999                 }
1000
1001                 /*
1002                  * Loop through length of segment after first fragment,
1003                  * make new header and copy data of each part and link onto
1004                  * chain.
1005                  */
1006                 m0 = m;
1007                 for (off = hlen; off < tlen; off += len) {
1008                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
1009                         if (!m) {
1010                                 error = ENOBUFS;
1011                                 ip6stat.ip6s_odropped++;
1012                                 goto sendorfree;
1013                         }
1014                         m->m_pkthdr.rcvif = NULL;
1015                         m->m_flags = m0->m_flags & M_COPYFLAGS;
1016                         *mnext = m;
1017                         mnext = &m->m_nextpkt;
1018                         m->m_data += max_linkhdr;
1019                         mhip6 = mtod(m, struct ip6_hdr *);
1020                         *mhip6 = *ip6;
1021                         m->m_len = sizeof(*mhip6);
1022                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1023                         if (error) {
1024                                 ip6stat.ip6s_odropped++;
1025                                 goto sendorfree;
1026                         }
1027                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1028                         if (off + len >= tlen)
1029                                 len = tlen - off;
1030                         else
1031                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1032                         mhip6->ip6_plen = htons((u_short)(len + hlen +
1033                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1034                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1035                                 error = ENOBUFS;
1036                                 ip6stat.ip6s_odropped++;
1037                                 goto sendorfree;
1038                         }
1039                         m_cat(m, m_frgpart);
1040                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1041                         m->m_pkthdr.rcvif = NULL;
1042                         ip6f->ip6f_reserved = 0;
1043                         ip6f->ip6f_ident = id;
1044                         ip6f->ip6f_nxt = nextproto;
1045                         ip6stat.ip6s_ofragments++;
1046                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1047                 }
1048
1049                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1050         }
1051
1052         /*
1053          * Remove leading garbages.
1054          */
1055 sendorfree:
1056         m = m0->m_nextpkt;
1057         m0->m_nextpkt = 0;
1058         m_freem(m0);
1059         for (m0 = m; m; m = m0) {
1060                 m0 = m->m_nextpkt;
1061                 m->m_nextpkt = 0;
1062                 if (error == 0) {
1063                         /* Record statistics for this interface address. */
1064                         if (ia) {
1065                                 ia->ia_ifa.if_opackets++;
1066                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1067                         }
1068                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1069                 } else
1070                         m_freem(m);
1071         }
1072
1073         if (error == 0)
1074                 ip6stat.ip6s_fragmented++;
1075
1076 done:
1077         if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
1078                 RTFREE(ro->ro_rt);
1079         } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
1080                 RTFREE(ro_pmtu->ro_rt);
1081         }
1082
1083         return (error);
1084
1085 freehdrs:
1086         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1087         m_freem(exthdrs.ip6e_dest1);
1088         m_freem(exthdrs.ip6e_rthdr);
1089         m_freem(exthdrs.ip6e_dest2);
1090         /* FALLTHROUGH */
1091 bad:
1092         if (m)
1093                 m_freem(m);
1094         goto done;
1095 }
1096
1097 static int
1098 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1099 {
1100         struct mbuf *m;
1101
1102         if (hlen > MCLBYTES)
1103                 return (ENOBUFS); /* XXX */
1104
1105         MGET(m, M_DONTWAIT, MT_DATA);
1106         if (!m)
1107                 return (ENOBUFS);
1108
1109         if (hlen > MLEN) {
1110                 MCLGET(m, M_DONTWAIT);
1111                 if ((m->m_flags & M_EXT) == 0) {
1112                         m_free(m);
1113                         return (ENOBUFS);
1114                 }
1115         }
1116         m->m_len = hlen;
1117         if (hdr)
1118                 bcopy(hdr, mtod(m, caddr_t), hlen);
1119
1120         *mp = m;
1121         return (0);
1122 }
1123
1124 /*
1125  * Insert jumbo payload option.
1126  */
1127 static int
1128 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1129 {
1130         struct mbuf *mopt;
1131         u_char *optbuf;
1132         u_int32_t v;
1133
1134 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1135
1136         /*
1137          * If there is no hop-by-hop options header, allocate new one.
1138          * If there is one but it doesn't have enough space to store the
1139          * jumbo payload option, allocate a cluster to store the whole options.
1140          * Otherwise, use it to store the options.
1141          */
1142         if (exthdrs->ip6e_hbh == 0) {
1143                 MGET(mopt, M_DONTWAIT, MT_DATA);
1144                 if (mopt == 0)
1145                         return (ENOBUFS);
1146                 mopt->m_len = JUMBOOPTLEN;
1147                 optbuf = mtod(mopt, u_char *);
1148                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1149                 exthdrs->ip6e_hbh = mopt;
1150         } else {
1151                 struct ip6_hbh *hbh;
1152
1153                 mopt = exthdrs->ip6e_hbh;
1154                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1155                         /*
1156                          * XXX assumption:
1157                          * - exthdrs->ip6e_hbh is not referenced from places
1158                          *   other than exthdrs.
1159                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1160                          */
1161                         int oldoptlen = mopt->m_len;
1162                         struct mbuf *n;
1163
1164                         /*
1165                          * XXX: give up if the whole (new) hbh header does
1166                          * not fit even in an mbuf cluster.
1167                          */
1168                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1169                                 return (ENOBUFS);
1170
1171                         /*
1172                          * As a consequence, we must always prepare a cluster
1173                          * at this point.
1174                          */
1175                         MGET(n, M_DONTWAIT, MT_DATA);
1176                         if (n) {
1177                                 MCLGET(n, M_DONTWAIT);
1178                                 if ((n->m_flags & M_EXT) == 0) {
1179                                         m_freem(n);
1180                                         n = NULL;
1181                                 }
1182                         }
1183                         if (!n)
1184                                 return (ENOBUFS);
1185                         n->m_len = oldoptlen + JUMBOOPTLEN;
1186                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1187                             oldoptlen);
1188                         optbuf = mtod(n, caddr_t) + oldoptlen;
1189                         m_freem(mopt);
1190                         mopt = exthdrs->ip6e_hbh = n;
1191                 } else {
1192                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1193                         mopt->m_len += JUMBOOPTLEN;
1194                 }
1195                 optbuf[0] = IP6OPT_PADN;
1196                 optbuf[1] = 1;
1197
1198                 /*
1199                  * Adjust the header length according to the pad and
1200                  * the jumbo payload option.
1201                  */
1202                 hbh = mtod(mopt, struct ip6_hbh *);
1203                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1204         }
1205
1206         /* fill in the option. */
1207         optbuf[2] = IP6OPT_JUMBO;
1208         optbuf[3] = 4;
1209         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1210         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1211
1212         /* finally, adjust the packet header length */
1213         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1214
1215         return (0);
1216 #undef JUMBOOPTLEN
1217 }
1218
1219 /*
1220  * Insert fragment header and copy unfragmentable header portions.
1221  */
1222 static int
1223 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1224     struct ip6_frag **frghdrp)
1225 {
1226         struct mbuf *n, *mlast;
1227
1228         if (hlen > sizeof(struct ip6_hdr)) {
1229                 n = m_copym(m0, sizeof(struct ip6_hdr),
1230                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
1231                 if (n == 0)
1232                         return (ENOBUFS);
1233                 m->m_next = n;
1234         } else
1235                 n = m;
1236
1237         /* Search for the last mbuf of unfragmentable part. */
1238         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1239                 ;
1240
1241         if ((mlast->m_flags & M_EXT) == 0 &&
1242             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1243                 /* use the trailing space of the last mbuf for the fragment hdr */
1244                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1245                     mlast->m_len);
1246                 mlast->m_len += sizeof(struct ip6_frag);
1247                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1248         } else {
1249                 /* allocate a new mbuf for the fragment header */
1250                 struct mbuf *mfrg;
1251
1252                 MGET(mfrg, M_DONTWAIT, MT_DATA);
1253                 if (mfrg == 0)
1254                         return (ENOBUFS);
1255                 mfrg->m_len = sizeof(struct ip6_frag);
1256                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1257                 mlast->m_next = mfrg;
1258         }
1259
1260         return (0);
1261 }
1262
1263 static int
1264 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1265     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1266     int *alwaysfragp)
1267 {
1268         u_int32_t mtu = 0;
1269         int alwaysfrag = 0;
1270         int error = 0;
1271
1272         if (ro_pmtu != ro) {
1273                 /* The first hop and the final destination may differ. */
1274                 struct sockaddr_in6 *sa6_dst =
1275                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1276                 if (ro_pmtu->ro_rt &&
1277                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1278                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1279                         RTFREE(ro_pmtu->ro_rt);
1280                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
1281                 }
1282                 if (ro_pmtu->ro_rt == NULL) {
1283                         bzero(sa6_dst, sizeof(*sa6_dst));
1284                         sa6_dst->sin6_family = AF_INET6;
1285                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1286                         sa6_dst->sin6_addr = *dst;
1287
1288                         rtalloc((struct route *)ro_pmtu);
1289                 }
1290         }
1291         if (ro_pmtu->ro_rt) {
1292                 u_int32_t ifmtu;
1293                 struct in_conninfo inc;
1294
1295                 bzero(&inc, sizeof(inc));
1296                 inc.inc_flags = 1; /* IPv6 */
1297                 inc.inc6_faddr = *dst;
1298
1299                 if (ifp == NULL)
1300                         ifp = ro_pmtu->ro_rt->rt_ifp;
1301                 ifmtu = IN6_LINKMTU(ifp);
1302                 mtu = tcp_hc_getmtu(&inc);
1303                 if (mtu)
1304                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
1305                 else
1306                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1307                 if (mtu == 0)
1308                         mtu = ifmtu;
1309                 else if (mtu < IPV6_MMTU) {
1310                         /*
1311                          * RFC2460 section 5, last paragraph:
1312                          * if we record ICMPv6 too big message with
1313                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1314                          * or smaller, with framgent header attached.
1315                          * (fragment header is needed regardless from the
1316                          * packet size, for translators to identify packets)
1317                          */
1318                         alwaysfrag = 1;
1319                         mtu = IPV6_MMTU;
1320                 } else if (mtu > ifmtu) {
1321                         /*
1322                          * The MTU on the route is larger than the MTU on
1323                          * the interface!  This shouldn't happen, unless the
1324                          * MTU of the interface has been changed after the
1325                          * interface was brought up.  Change the MTU in the
1326                          * route to match the interface MTU (as long as the
1327                          * field isn't locked).
1328                          */
1329                         mtu = ifmtu;
1330                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1331                 }
1332         } else if (ifp) {
1333                 mtu = IN6_LINKMTU(ifp);
1334         } else
1335                 error = EHOSTUNREACH; /* XXX */
1336
1337         *mtup = mtu;
1338         if (alwaysfragp)
1339                 *alwaysfragp = alwaysfrag;
1340         return (error);
1341 }
1342
1343 /*
1344  * IP6 socket option processing.
1345  */
1346 int
1347 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1348 {
1349         int privileged, optdatalen, uproto;
1350         void *optdata;
1351         struct inpcb *in6p = sotoinpcb(so);
1352         int error, optval;
1353         int level, op, optname;
1354         int optlen;
1355         struct thread *td;
1356
1357         if (sopt) {
1358                 level = sopt->sopt_level;
1359                 op = sopt->sopt_dir;
1360                 optname = sopt->sopt_name;
1361                 optlen = sopt->sopt_valsize;
1362                 td = sopt->sopt_td;
1363         } else {
1364                 panic("ip6_ctloutput: arg soopt is NULL");
1365         }
1366         error = optval = 0;
1367
1368         privileged = (td == 0 || suser(td)) ? 0 : 1;
1369         uproto = (int)so->so_proto->pr_protocol;
1370
1371         if (level == IPPROTO_IPV6) {
1372                 switch (op) {
1373
1374                 case SOPT_SET:
1375                         switch (optname) {
1376                         case IPV6_2292PKTOPTIONS:
1377 #ifdef IPV6_PKTOPTIONS
1378                         case IPV6_PKTOPTIONS:
1379 #endif
1380                         {
1381                                 struct mbuf *m;
1382
1383                                 error = soopt_getm(sopt, &m); /* XXX */
1384                                 if (error != 0)
1385                                         break;
1386                                 error = soopt_mcopyin(sopt, m); /* XXX */
1387                                 if (error != 0)
1388                                         break;
1389                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1390                                                     m, so, sopt);
1391                                 m_freem(m); /* XXX */
1392                                 break;
1393                         }
1394
1395                         /*
1396                          * Use of some Hop-by-Hop options or some
1397                          * Destination options, might require special
1398                          * privilege.  That is, normal applications
1399                          * (without special privilege) might be forbidden
1400                          * from setting certain options in outgoing packets,
1401                          * and might never see certain options in received
1402                          * packets. [RFC 2292 Section 6]
1403                          * KAME specific note:
1404                          *  KAME prevents non-privileged users from sending or
1405                          *  receiving ANY hbh/dst options in order to avoid
1406                          *  overhead of parsing options in the kernel.
1407                          */
1408                         case IPV6_RECVHOPOPTS:
1409                         case IPV6_RECVDSTOPTS:
1410                         case IPV6_RECVRTHDRDSTOPTS:
1411                                 if (!privileged) {
1412                                         error = EPERM;
1413                                         break;
1414                                 }
1415                                 /* FALLTHROUGH */
1416                         case IPV6_UNICAST_HOPS:
1417                         case IPV6_HOPLIMIT:
1418                         case IPV6_FAITH:
1419
1420                         case IPV6_RECVPKTINFO:
1421                         case IPV6_RECVHOPLIMIT:
1422                         case IPV6_RECVRTHDR:
1423                         case IPV6_RECVPATHMTU:
1424                         case IPV6_RECVTCLASS:
1425                         case IPV6_V6ONLY:
1426                         case IPV6_AUTOFLOWLABEL:
1427                                 if (optlen != sizeof(int)) {
1428                                         error = EINVAL;
1429                                         break;
1430                                 }
1431                                 error = sooptcopyin(sopt, &optval,
1432                                         sizeof optval, sizeof optval);
1433                                 if (error)
1434                                         break;
1435                                 switch (optname) {
1436
1437                                 case IPV6_UNICAST_HOPS:
1438                                         if (optval < -1 || optval >= 256)
1439                                                 error = EINVAL;
1440                                         else {
1441                                                 /* -1 = kernel default */
1442                                                 in6p->in6p_hops = optval;
1443                                                 if ((in6p->in6p_vflag &
1444                                                      INP_IPV4) != 0)
1445                                                         in6p->inp_ip_ttl = optval;
1446                                         }
1447                                         break;
1448 #define OPTSET(bit) \
1449 do { \
1450         if (optval) \
1451                 in6p->in6p_flags |= (bit); \
1452         else \
1453                 in6p->in6p_flags &= ~(bit); \
1454 } while (/*CONSTCOND*/ 0)
1455 #define OPTSET2292(bit) \
1456 do { \
1457         in6p->in6p_flags |= IN6P_RFC2292; \
1458         if (optval) \
1459                 in6p->in6p_flags |= (bit); \
1460         else \
1461                 in6p->in6p_flags &= ~(bit); \
1462 } while (/*CONSTCOND*/ 0)
1463 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
1464
1465                                 case IPV6_RECVPKTINFO:
1466                                         /* cannot mix with RFC2292 */
1467                                         if (OPTBIT(IN6P_RFC2292)) {
1468                                                 error = EINVAL;
1469                                                 break;
1470                                         }
1471                                         OPTSET(IN6P_PKTINFO);
1472                                         break;
1473
1474                                 case IPV6_HOPLIMIT:
1475                                 {
1476                                         struct ip6_pktopts **optp;
1477
1478                                         /* cannot mix with RFC2292 */
1479                                         if (OPTBIT(IN6P_RFC2292)) {
1480                                                 error = EINVAL;
1481                                                 break;
1482                                         }
1483                                         optp = &in6p->in6p_outputopts;
1484                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1485                                                            (u_char *)&optval,
1486                                                            sizeof(optval),
1487                                                            optp,
1488                                                            privileged, uproto);
1489                                         break;
1490                                 }
1491
1492                                 case IPV6_RECVHOPLIMIT:
1493                                         /* cannot mix with RFC2292 */
1494                                         if (OPTBIT(IN6P_RFC2292)) {
1495                                                 error = EINVAL;
1496                                                 break;
1497                                         }
1498                                         OPTSET(IN6P_HOPLIMIT);
1499                                         break;
1500
1501                                 case IPV6_RECVHOPOPTS:
1502                                         /* cannot mix with RFC2292 */
1503                                         if (OPTBIT(IN6P_RFC2292)) {
1504                                                 error = EINVAL;
1505                                                 break;
1506                                         }
1507                                         OPTSET(IN6P_HOPOPTS);
1508                                         break;
1509
1510                                 case IPV6_RECVDSTOPTS:
1511                                         /* cannot mix with RFC2292 */
1512                                         if (OPTBIT(IN6P_RFC2292)) {
1513                                                 error = EINVAL;
1514                                                 break;
1515                                         }
1516                                         OPTSET(IN6P_DSTOPTS);
1517                                         break;
1518
1519                                 case IPV6_RECVRTHDRDSTOPTS:
1520                                         /* cannot mix with RFC2292 */
1521                                         if (OPTBIT(IN6P_RFC2292)) {
1522                                                 error = EINVAL;
1523                                                 break;
1524                                         }
1525                                         OPTSET(IN6P_RTHDRDSTOPTS);
1526                                         break;
1527
1528                                 case IPV6_RECVRTHDR:
1529                                         /* cannot mix with RFC2292 */
1530                                         if (OPTBIT(IN6P_RFC2292)) {
1531                                                 error = EINVAL;
1532                                                 break;
1533                                         }
1534                                         OPTSET(IN6P_RTHDR);
1535                                         break;
1536
1537                                 case IPV6_FAITH:
1538                                         OPTSET(IN6P_FAITH);
1539                                         break;
1540
1541                                 case IPV6_RECVPATHMTU:
1542                                         /*
1543                                          * We ignore this option for TCP
1544                                          * sockets.
1545                                          * (RFC3542 leaves this case
1546                                          * unspecified.)
1547                                          */
1548                                         if (uproto != IPPROTO_TCP)
1549                                                 OPTSET(IN6P_MTU);
1550                                         break;
1551
1552                                 case IPV6_V6ONLY:
1553                                         /*
1554                                          * make setsockopt(IPV6_V6ONLY)
1555                                          * available only prior to bind(2).
1556                                          * see ipng mailing list, Jun 22 2001.
1557                                          */
1558                                         if (in6p->in6p_lport ||
1559                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1560                                                 error = EINVAL;
1561                                                 break;
1562                                         }
1563                                         OPTSET(IN6P_IPV6_V6ONLY);
1564                                         if (optval)
1565                                                 in6p->in6p_vflag &= ~INP_IPV4;
1566                                         else
1567                                                 in6p->in6p_vflag |= INP_IPV4;
1568                                         break;
1569                                 case IPV6_RECVTCLASS:
1570                                         /* cannot mix with RFC2292 XXX */
1571                                         if (OPTBIT(IN6P_RFC2292)) {
1572                                                 error = EINVAL;
1573                                                 break;
1574                                         }
1575                                         OPTSET(IN6P_TCLASS);
1576                                         break;
1577                                 case IPV6_AUTOFLOWLABEL:
1578                                         OPTSET(IN6P_AUTOFLOWLABEL);
1579                                         break;
1580
1581                                 }
1582                                 break;
1583
1584                         case IPV6_TCLASS:
1585                         case IPV6_DONTFRAG:
1586                         case IPV6_USE_MIN_MTU:
1587                         case IPV6_PREFER_TEMPADDR:
1588                                 if (optlen != sizeof(optval)) {
1589                                         error = EINVAL;
1590                                         break;
1591                                 }
1592                                 error = sooptcopyin(sopt, &optval,
1593                                         sizeof optval, sizeof optval);
1594                                 if (error)
1595                                         break;
1596                                 {
1597                                         struct ip6_pktopts **optp;
1598                                         optp = &in6p->in6p_outputopts;
1599                                         error = ip6_pcbopt(optname,
1600                                                            (u_char *)&optval,
1601                                                            sizeof(optval),
1602                                                            optp,
1603                                                            privileged, uproto);
1604                                         break;
1605                                 }
1606
1607                         case IPV6_2292PKTINFO:
1608                         case IPV6_2292HOPLIMIT:
1609                         case IPV6_2292HOPOPTS:
1610                         case IPV6_2292DSTOPTS:
1611                         case IPV6_2292RTHDR:
1612                                 /* RFC 2292 */
1613                                 if (optlen != sizeof(int)) {
1614                                         error = EINVAL;
1615                                         break;
1616                                 }
1617                                 error = sooptcopyin(sopt, &optval,
1618                                         sizeof optval, sizeof optval);
1619                                 if (error)
1620                                         break;
1621                                 switch (optname) {
1622                                 case IPV6_2292PKTINFO:
1623                                         OPTSET2292(IN6P_PKTINFO);
1624                                         break;
1625                                 case IPV6_2292HOPLIMIT:
1626                                         OPTSET2292(IN6P_HOPLIMIT);
1627                                         break;
1628                                 case IPV6_2292HOPOPTS:
1629                                         /*
1630                                          * Check super-user privilege.
1631                                          * See comments for IPV6_RECVHOPOPTS.
1632                                          */
1633                                         if (!privileged)
1634                                                 return (EPERM);
1635                                         OPTSET2292(IN6P_HOPOPTS);
1636                                         break;
1637                                 case IPV6_2292DSTOPTS:
1638                                         if (!privileged)
1639                                                 return (EPERM);
1640                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1641                                         break;
1642                                 case IPV6_2292RTHDR:
1643                                         OPTSET2292(IN6P_RTHDR);
1644                                         break;
1645                                 }
1646                                 break;
1647                         case IPV6_PKTINFO:
1648                         case IPV6_HOPOPTS:
1649                         case IPV6_RTHDR:
1650                         case IPV6_DSTOPTS:
1651                         case IPV6_RTHDRDSTOPTS:
1652                         case IPV6_NEXTHOP:
1653                         {
1654                                 /* new advanced API (RFC3542) */
1655                                 u_char *optbuf;
1656                                 u_char optbuf_storage[MCLBYTES];
1657                                 int optlen;
1658                                 struct ip6_pktopts **optp;
1659
1660                                 /* cannot mix with RFC2292 */
1661                                 if (OPTBIT(IN6P_RFC2292)) {
1662                                         error = EINVAL;
1663                                         break;
1664                                 }
1665
1666                                 /*
1667                                  * We only ensure valsize is not too large
1668                                  * here.  Further validation will be done
1669                                  * later.
1670                                  */
1671                                 error = sooptcopyin(sopt, optbuf_storage,
1672                                     sizeof(optbuf_storage), 0);
1673                                 if (error)
1674                                         break;
1675                                 optlen = sopt->sopt_valsize;
1676                                 optbuf = optbuf_storage;
1677                                 optp = &in6p->in6p_outputopts;
1678                                 error = ip6_pcbopt(optname,
1679                                                    optbuf, optlen,
1680                                                    optp, privileged, uproto);
1681                                 break;
1682                         }
1683 #undef OPTSET
1684
1685                         case IPV6_MULTICAST_IF:
1686                         case IPV6_MULTICAST_HOPS:
1687                         case IPV6_MULTICAST_LOOP:
1688                         case IPV6_JOIN_GROUP:
1689                         case IPV6_LEAVE_GROUP:
1690                             {
1691                                 if (sopt->sopt_valsize > MLEN) {
1692                                         error = EMSGSIZE;
1693                                         break;
1694                                 }
1695                                 /* XXX */
1696                             }
1697                             /* FALLTHROUGH */
1698                             {
1699                                 struct mbuf *m;
1700
1701                                 if (sopt->sopt_valsize > MCLBYTES) {
1702                                         error = EMSGSIZE;
1703                                         break;
1704                                 }
1705                                 /* XXX */
1706                                 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
1707                                 if (m == 0) {
1708                                         error = ENOBUFS;
1709                                         break;
1710                                 }
1711                                 if (sopt->sopt_valsize > MLEN) {
1712                                         MCLGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT);
1713                                         if ((m->m_flags & M_EXT) == 0) {
1714                                                 m_free(m);
1715                                                 error = ENOBUFS;
1716                                                 break;
1717                                         }
1718                                 }
1719                                 m->m_len = sopt->sopt_valsize;
1720                                 error = sooptcopyin(sopt, mtod(m, char *),
1721                                                     m->m_len, m->m_len);
1722                                 if (error) {
1723                                         (void)m_free(m);
1724                                         break;
1725                                 }
1726                                 error = ip6_setmoptions(sopt->sopt_name,
1727                                                         &in6p->in6p_moptions,
1728                                                         m);
1729                                 (void)m_free(m);
1730                             }
1731                                 break;
1732
1733                         case IPV6_PORTRANGE:
1734                                 error = sooptcopyin(sopt, &optval,
1735                                     sizeof optval, sizeof optval);
1736                                 if (error)
1737                                         break;
1738
1739                                 switch (optval) {
1740                                 case IPV6_PORTRANGE_DEFAULT:
1741                                         in6p->in6p_flags &= ~(IN6P_LOWPORT);
1742                                         in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1743                                         break;
1744
1745                                 case IPV6_PORTRANGE_HIGH:
1746                                         in6p->in6p_flags &= ~(IN6P_LOWPORT);
1747                                         in6p->in6p_flags |= IN6P_HIGHPORT;
1748                                         break;
1749
1750                                 case IPV6_PORTRANGE_LOW:
1751                                         in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1752                                         in6p->in6p_flags |= IN6P_LOWPORT;
1753                                         break;
1754
1755                                 default:
1756                                         error = EINVAL;
1757                                         break;
1758                                 }
1759                                 break;
1760
1761 #ifdef IPSEC
1762                         case IPV6_IPSEC_POLICY:
1763                             {
1764                                 caddr_t req = NULL;
1765                                 size_t len = 0;
1766                                 struct mbuf *m;
1767
1768                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1769                                         break;
1770                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1771                                         break;
1772                                 if (m) {
1773                                         req = mtod(m, caddr_t);
1774                                         len = m->m_len;
1775                                 }
1776                                 error = ipsec6_set_policy(in6p, optname, req,
1777                                                           len, privileged);
1778                                 m_freem(m);
1779                             }
1780                                 break;
1781 #endif /* IPSEC */
1782
1783                         default:
1784                                 error = ENOPROTOOPT;
1785                                 break;
1786                         }
1787                         break;
1788
1789                 case SOPT_GET:
1790                         switch (optname) {
1791
1792                         case IPV6_2292PKTOPTIONS:
1793 #ifdef IPV6_PKTOPTIONS
1794                         case IPV6_PKTOPTIONS:
1795 #endif
1796                                 /*
1797                                  * RFC3542 (effectively) deprecated the
1798                                  * semantics of the 2292-style pktoptions.
1799                                  * Since it was not reliable in nature (i.e.,
1800                                  * applications had to expect the lack of some
1801                                  * information after all), it would make sense
1802                                  * to simplify this part by always returning
1803                                  * empty data.
1804                                  */
1805                                 sopt->sopt_valsize = 0;
1806                                 break;
1807
1808                         case IPV6_RECVHOPOPTS:
1809                         case IPV6_RECVDSTOPTS:
1810                         case IPV6_RECVRTHDRDSTOPTS:
1811                         case IPV6_UNICAST_HOPS:
1812                         case IPV6_RECVPKTINFO:
1813                         case IPV6_RECVHOPLIMIT:
1814                         case IPV6_RECVRTHDR:
1815                         case IPV6_RECVPATHMTU:
1816
1817                         case IPV6_FAITH:
1818                         case IPV6_V6ONLY:
1819                         case IPV6_PORTRANGE:
1820                         case IPV6_RECVTCLASS:
1821                         case IPV6_AUTOFLOWLABEL:
1822                                 switch (optname) {
1823
1824                                 case IPV6_RECVHOPOPTS:
1825                                         optval = OPTBIT(IN6P_HOPOPTS);
1826                                         break;
1827
1828                                 case IPV6_RECVDSTOPTS:
1829                                         optval = OPTBIT(IN6P_DSTOPTS);
1830                                         break;
1831
1832                                 case IPV6_RECVRTHDRDSTOPTS:
1833                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1834                                         break;
1835
1836                                 case IPV6_UNICAST_HOPS:
1837                                         optval = in6p->in6p_hops;
1838                                         break;
1839
1840                                 case IPV6_RECVPKTINFO:
1841                                         optval = OPTBIT(IN6P_PKTINFO);
1842                                         break;
1843
1844                                 case IPV6_RECVHOPLIMIT:
1845                                         optval = OPTBIT(IN6P_HOPLIMIT);
1846                                         break;
1847
1848                                 case IPV6_RECVRTHDR:
1849                                         optval = OPTBIT(IN6P_RTHDR);
1850                                         break;
1851
1852                                 case IPV6_RECVPATHMTU:
1853                                         optval = OPTBIT(IN6P_MTU);
1854                                         break;
1855
1856                                 case IPV6_FAITH:
1857                                         optval = OPTBIT(IN6P_FAITH);
1858                                         break;
1859
1860                                 case IPV6_V6ONLY:
1861                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1862                                         break;
1863
1864                                 case IPV6_PORTRANGE:
1865                                     {
1866                                         int flags;
1867                                         flags = in6p->in6p_flags;
1868                                         if (flags & IN6P_HIGHPORT)
1869                                                 optval = IPV6_PORTRANGE_HIGH;
1870                                         else if (flags & IN6P_LOWPORT)
1871                                                 optval = IPV6_PORTRANGE_LOW;
1872                                         else
1873                                                 optval = 0;
1874                                         break;
1875                                     }
1876                                 case IPV6_RECVTCLASS:
1877                                         optval = OPTBIT(IN6P_TCLASS);
1878                                         break;
1879
1880                                 case IPV6_AUTOFLOWLABEL:
1881                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1882                                         break;
1883                                 }
1884                                 if (error)
1885                                         break;
1886                                 error = sooptcopyout(sopt, &optval,
1887                                         sizeof optval);
1888                                 break;
1889
1890                         case IPV6_PATHMTU:
1891                         {
1892                                 u_long pmtu = 0;
1893                                 struct ip6_mtuinfo mtuinfo;
1894                                 struct route_in6 sro;
1895
1896                                 bzero(&sro, sizeof(sro));
1897
1898                                 if (!(so->so_state & SS_ISCONNECTED))
1899                                         return (ENOTCONN);
1900                                 /*
1901                                  * XXX: we dot not consider the case of source
1902                                  * routing, or optional information to specify
1903                                  * the outgoing interface.
1904                                  */
1905                                 error = ip6_getpmtu(&sro, NULL, NULL,
1906                                     &in6p->in6p_faddr, &pmtu, NULL);
1907                                 if (sro.ro_rt)
1908                                         RTFREE(sro.ro_rt);
1909                                 if (error)
1910                                         break;
1911                                 if (pmtu > IPV6_MAXPACKET)
1912                                         pmtu = IPV6_MAXPACKET;
1913
1914                                 bzero(&mtuinfo, sizeof(mtuinfo));
1915                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1916                                 optdata = (void *)&mtuinfo;
1917                                 optdatalen = sizeof(mtuinfo);
1918                                 error = sooptcopyout(sopt, optdata,
1919                                     optdatalen);
1920                                 break;
1921                         }
1922
1923                         case IPV6_2292PKTINFO:
1924                         case IPV6_2292HOPLIMIT:
1925                         case IPV6_2292HOPOPTS:
1926                         case IPV6_2292RTHDR:
1927                         case IPV6_2292DSTOPTS:
1928                                 switch (optname) {
1929                                 case IPV6_2292PKTINFO:
1930                                         optval = OPTBIT(IN6P_PKTINFO);
1931                                         break;
1932                                 case IPV6_2292HOPLIMIT:
1933                                         optval = OPTBIT(IN6P_HOPLIMIT);
1934                                         break;
1935                                 case IPV6_2292HOPOPTS:
1936                                         optval = OPTBIT(IN6P_HOPOPTS);
1937                                         break;
1938                                 case IPV6_2292RTHDR:
1939                                         optval = OPTBIT(IN6P_RTHDR);
1940                                         break;
1941                                 case IPV6_2292DSTOPTS:
1942                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1943                                         break;
1944                                 }
1945                                 error = sooptcopyout(sopt, &optval,
1946                                     sizeof optval);
1947                                 break;
1948                         case IPV6_PKTINFO:
1949                         case IPV6_HOPOPTS:
1950                         case IPV6_RTHDR:
1951                         case IPV6_DSTOPTS:
1952                         case IPV6_RTHDRDSTOPTS:
1953                         case IPV6_NEXTHOP:
1954                         case IPV6_TCLASS:
1955                         case IPV6_DONTFRAG:
1956                         case IPV6_USE_MIN_MTU:
1957                         case IPV6_PREFER_TEMPADDR:
1958                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
1959                                     optname, sopt);
1960                                 break;
1961
1962                         case IPV6_MULTICAST_IF:
1963                         case IPV6_MULTICAST_HOPS:
1964                         case IPV6_MULTICAST_LOOP:
1965                         case IPV6_JOIN_GROUP:
1966                         case IPV6_LEAVE_GROUP:
1967                             {
1968                                 struct mbuf *m;
1969                                 error = ip6_getmoptions(sopt->sopt_name,
1970                                     in6p->in6p_moptions, &m);
1971                                 if (error == 0)
1972                                         error = sooptcopyout(sopt,
1973                                             mtod(m, char *), m->m_len);
1974                                 m_freem(m);
1975                             }
1976                                 break;
1977
1978 #ifdef IPSEC
1979                         case IPV6_IPSEC_POLICY:
1980                           {
1981                                 caddr_t req = NULL;
1982                                 size_t len = 0;
1983                                 struct mbuf *m = NULL;
1984                                 struct mbuf **mp = &m;
1985                                 size_t ovalsize = sopt->sopt_valsize;
1986                                 caddr_t oval = (caddr_t)sopt->sopt_val;
1987
1988                                 error = soopt_getm(sopt, &m); /* XXX */
1989                                 if (error != 0)
1990                                         break;
1991                                 error = soopt_mcopyin(sopt, m); /* XXX */
1992                                 if (error != 0)
1993                                         break;
1994                                 sopt->sopt_valsize = ovalsize;
1995                                 sopt->sopt_val = oval;
1996                                 if (m) {
1997                                         req = mtod(m, caddr_t);
1998                                         len = m->m_len;
1999                                 }
2000                                 error = ipsec6_get_policy(in6p, req, len, mp);
2001                                 if (error == 0)
2002                                         error = soopt_mcopyout(sopt, m); /* XXX */
2003                                 if (error == 0 && m)
2004                                         m_freem(m);
2005                                 break;
2006                           }
2007 #endif /* IPSEC */
2008
2009                         default:
2010                                 error = ENOPROTOOPT;
2011                                 break;
2012                         }
2013                         break;
2014                 }
2015         } else {                /* level != IPPROTO_IPV6 */
2016                 error = EINVAL;
2017         }
2018         return (error);
2019 }
2020
2021 int
2022 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2023 {
2024         int error = 0, optval, optlen;
2025         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2026         struct in6pcb *in6p = sotoin6pcb(so);
2027         int level, op, optname;
2028
2029         if (sopt) {
2030                 level = sopt->sopt_level;
2031                 op = sopt->sopt_dir;
2032                 optname = sopt->sopt_name;
2033                 optlen = sopt->sopt_valsize;
2034         } else
2035                 panic("ip6_raw_ctloutput: arg soopt is NULL");
2036
2037         if (level != IPPROTO_IPV6) {
2038                 return (EINVAL);
2039         }
2040
2041         switch (optname) {
2042         case IPV6_CHECKSUM:
2043                 /*
2044                  * For ICMPv6 sockets, no modification allowed for checksum
2045                  * offset, permit "no change" values to help existing apps.
2046                  *
2047                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2048                  * for an ICMPv6 socket will fail."
2049                  * The current behavior does not meet RFC3542.
2050                  */
2051                 switch (op) {
2052                 case SOPT_SET:
2053                         if (optlen != sizeof(int)) {
2054                                 error = EINVAL;
2055                                 break;
2056                         }
2057                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2058                                             sizeof(optval));
2059                         if (error)
2060                                 break;
2061                         if ((optval % 2) != 0) {
2062                                 /* the API assumes even offset values */
2063                                 error = EINVAL;
2064                         } else if (so->so_proto->pr_protocol ==
2065                             IPPROTO_ICMPV6) {
2066                                 if (optval != icmp6off)
2067                                         error = EINVAL;
2068                         } else
2069                                 in6p->in6p_cksum = optval;
2070                         break;
2071
2072                 case SOPT_GET:
2073                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2074                                 optval = icmp6off;
2075                         else
2076                                 optval = in6p->in6p_cksum;
2077
2078                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2079                         break;
2080
2081                 default:
2082                         error = EINVAL;
2083                         break;
2084                 }
2085                 break;
2086
2087         default:
2088                 error = ENOPROTOOPT;
2089                 break;
2090         }
2091
2092         return (error);
2093 }
2094
2095 /*
2096  * Set up IP6 options in pcb for insertion in output packets or
2097  * specifying behavior of outgoing packets.
2098  */
2099 static int
2100 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2101     struct socket *so, struct sockopt *sopt)
2102 {
2103         struct ip6_pktopts *opt = *pktopt;
2104         int error = 0;
2105         struct thread *td = sopt->sopt_td;
2106         int priv = 0;
2107
2108         /* turn off any old options. */
2109         if (opt) {
2110 #ifdef DIAGNOSTIC
2111                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2112                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2113                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2114                         printf("ip6_pcbopts: all specified options are cleared.\n");
2115 #endif
2116                 ip6_clearpktopts(opt, -1);
2117         } else
2118                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2119         *pktopt = NULL;
2120
2121         if (!m || m->m_len == 0) {
2122                 /*
2123                  * Only turning off any previous options, regardless of
2124                  * whether the opt is just created or given.
2125                  */
2126                 free(opt, M_IP6OPT);
2127                 return (0);
2128         }
2129
2130         /*  set options specified by user. */
2131         if (td && !suser(td))
2132                 priv = 1;
2133         if ((error = ip6_setpktopts(m, opt, NULL, priv,
2134             so->so_proto->pr_protocol)) != 0) {
2135                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2136                 free(opt, M_IP6OPT);
2137                 return (error);
2138         }
2139         *pktopt = opt;
2140         return (0);
2141 }
2142
2143 /*
2144  * initialize ip6_pktopts.  beware that there are non-zero default values in
2145  * the struct.
2146  */
2147 void
2148 ip6_initpktopts(struct ip6_pktopts *opt)
2149 {
2150
2151         bzero(opt, sizeof(*opt));
2152         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2153         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2154         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2155         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2156 }
2157
2158 static int
2159 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2160     int priv, int uproto)
2161 {
2162         struct ip6_pktopts *opt;
2163
2164         if (*pktopt == NULL) {
2165                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2166                     M_WAITOK);
2167                 ip6_initpktopts(*pktopt);
2168         }
2169         opt = *pktopt;
2170
2171         return (ip6_setpktopt(optname, buf, len, opt, priv, 1, 0, uproto));
2172 }
2173
2174 static int
2175 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2176 {
2177         void *optdata = NULL;
2178         int optdatalen = 0;
2179         struct ip6_ext *ip6e;
2180         int error = 0;
2181         struct in6_pktinfo null_pktinfo;
2182         int deftclass = 0, on;
2183         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2184         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2185
2186         switch (optname) {
2187         case IPV6_PKTINFO:
2188                 if (pktopt && pktopt->ip6po_pktinfo)
2189                         optdata = (void *)pktopt->ip6po_pktinfo;
2190                 else {
2191                         /* XXX: we don't have to do this every time... */
2192                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2193                         optdata = (void *)&null_pktinfo;
2194                 }
2195                 optdatalen = sizeof(struct in6_pktinfo);
2196                 break;
2197         case IPV6_TCLASS:
2198                 if (pktopt && pktopt->ip6po_tclass >= 0)
2199                         optdata = (void *)&pktopt->ip6po_tclass;
2200                 else
2201                         optdata = (void *)&deftclass;
2202                 optdatalen = sizeof(int);
2203                 break;
2204         case IPV6_HOPOPTS:
2205                 if (pktopt && pktopt->ip6po_hbh) {
2206                         optdata = (void *)pktopt->ip6po_hbh;
2207                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2208                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2209                 }
2210                 break;
2211         case IPV6_RTHDR:
2212                 if (pktopt && pktopt->ip6po_rthdr) {
2213                         optdata = (void *)pktopt->ip6po_rthdr;
2214                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2215                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2216                 }
2217                 break;
2218         case IPV6_RTHDRDSTOPTS:
2219                 if (pktopt && pktopt->ip6po_dest1) {
2220                         optdata = (void *)pktopt->ip6po_dest1;
2221                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2222                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2223                 }
2224                 break;
2225         case IPV6_DSTOPTS:
2226                 if (pktopt && pktopt->ip6po_dest2) {
2227                         optdata = (void *)pktopt->ip6po_dest2;
2228                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2229                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2230                 }
2231                 break;
2232         case IPV6_NEXTHOP:
2233                 if (pktopt && pktopt->ip6po_nexthop) {
2234                         optdata = (void *)pktopt->ip6po_nexthop;
2235                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2236                 }
2237                 break;
2238         case IPV6_USE_MIN_MTU:
2239                 if (pktopt)
2240                         optdata = (void *)&pktopt->ip6po_minmtu;
2241                 else
2242                         optdata = (void *)&defminmtu;
2243                 optdatalen = sizeof(int);
2244                 break;
2245         case IPV6_DONTFRAG:
2246                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2247                         on = 1;
2248                 else
2249                         on = 0;
2250                 optdata = (void *)&on;
2251                 optdatalen = sizeof(on);
2252                 break;
2253         case IPV6_PREFER_TEMPADDR:
2254                 if (pktopt)
2255                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2256                 else
2257                         optdata = (void *)&defpreftemp;
2258                 optdatalen = sizeof(int);
2259                 break;
2260         default:                /* should not happen */
2261 #ifdef DIAGNOSTIC
2262                 panic("ip6_getpcbopt: unexpected option\n");
2263 #endif
2264                 return (ENOPROTOOPT);
2265         }
2266
2267         error = sooptcopyout(sopt, optdata, optdatalen);
2268
2269         return (error);
2270 }
2271
2272 void
2273 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2274 {
2275         if (pktopt == NULL)
2276                 return;
2277
2278         if (optname == -1 || optname == IPV6_PKTINFO) {
2279                 if (pktopt->ip6po_pktinfo)
2280                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2281                 pktopt->ip6po_pktinfo = NULL;
2282         }
2283         if (optname == -1 || optname == IPV6_HOPLIMIT)
2284                 pktopt->ip6po_hlim = -1;
2285         if (optname == -1 || optname == IPV6_TCLASS)
2286                 pktopt->ip6po_tclass = -1;
2287         if (optname == -1 || optname == IPV6_NEXTHOP) {
2288                 if (pktopt->ip6po_nextroute.ro_rt) {
2289                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2290                         pktopt->ip6po_nextroute.ro_rt = NULL;
2291                 }
2292                 if (pktopt->ip6po_nexthop)
2293                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2294                 pktopt->ip6po_nexthop = NULL;
2295         }
2296         if (optname == -1 || optname == IPV6_HOPOPTS) {
2297                 if (pktopt->ip6po_hbh)
2298                         free(pktopt->ip6po_hbh, M_IP6OPT);
2299                 pktopt->ip6po_hbh = NULL;
2300         }
2301         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2302                 if (pktopt->ip6po_dest1)
2303                         free(pktopt->ip6po_dest1, M_IP6OPT);
2304                 pktopt->ip6po_dest1 = NULL;
2305         }
2306         if (optname == -1 || optname == IPV6_RTHDR) {
2307                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2308                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2309                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2310                 if (pktopt->ip6po_route.ro_rt) {
2311                         RTFREE(pktopt->ip6po_route.ro_rt);
2312                         pktopt->ip6po_route.ro_rt = NULL;
2313                 }
2314         }
2315         if (optname == -1 || optname == IPV6_DSTOPTS) {
2316                 if (pktopt->ip6po_dest2)
2317                         free(pktopt->ip6po_dest2, M_IP6OPT);
2318                 pktopt->ip6po_dest2 = NULL;
2319         }
2320 }
2321
2322 #define PKTOPT_EXTHDRCPY(type) \
2323 do {\
2324         if (src->type) {\
2325                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2326                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2327                 if (dst->type == NULL && canwait == M_NOWAIT)\
2328                         goto bad;\
2329                 bcopy(src->type, dst->type, hlen);\
2330         }\
2331 } while (/*CONSTCOND*/ 0)
2332
2333 static int
2334 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2335 {
2336         if (dst == NULL || src == NULL)  {
2337                 printf("ip6_clearpktopts: invalid argument\n");
2338                 return (EINVAL);
2339         }
2340
2341         dst->ip6po_hlim = src->ip6po_hlim;
2342         dst->ip6po_tclass = src->ip6po_tclass;
2343         dst->ip6po_flags = src->ip6po_flags;
2344         if (src->ip6po_pktinfo) {
2345                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2346                     M_IP6OPT, canwait);
2347                 if (dst->ip6po_pktinfo == NULL)
2348                         goto bad;
2349                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2350         }
2351         if (src->ip6po_nexthop) {
2352                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2353                     M_IP6OPT, canwait);
2354                 if (dst->ip6po_nexthop == NULL)
2355                         goto bad;
2356                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2357                     src->ip6po_nexthop->sa_len);
2358         }
2359         PKTOPT_EXTHDRCPY(ip6po_hbh);
2360         PKTOPT_EXTHDRCPY(ip6po_dest1);
2361         PKTOPT_EXTHDRCPY(ip6po_dest2);
2362         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2363         return (0);
2364
2365   bad:
2366         ip6_clearpktopts(dst, -1);
2367         return (ENOBUFS);
2368 }
2369 #undef PKTOPT_EXTHDRCPY
2370
2371 struct ip6_pktopts *
2372 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2373 {
2374         int error;
2375         struct ip6_pktopts *dst;
2376
2377         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2378         if (dst == NULL)
2379                 return (NULL);
2380         ip6_initpktopts(dst);
2381
2382         if ((error = copypktopts(dst, src, canwait)) != 0) {
2383                 free(dst, M_IP6OPT);
2384                 return (NULL);
2385         }
2386
2387         return (dst);
2388 }
2389
2390 void
2391 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2392 {
2393         if (pktopt == NULL)
2394                 return;
2395
2396         ip6_clearpktopts(pktopt, -1);
2397
2398         free(pktopt, M_IP6OPT);
2399 }
2400
2401 /*
2402  * Set the IP6 multicast options in response to user setsockopt().
2403  */
2404 static int
2405 ip6_setmoptions(int optname, struct ip6_moptions **im6op, struct mbuf *m)
2406 {
2407         int error = 0;
2408         u_int loop, ifindex;
2409         struct ipv6_mreq *mreq;
2410         struct ifnet *ifp;
2411         struct ip6_moptions *im6o = *im6op;
2412         struct route_in6 ro;
2413         struct in6_multi_mship *imm;
2414         struct thread *td = curthread;
2415
2416         if (im6o == NULL) {
2417                 /*
2418                  * No multicast option buffer attached to the pcb;
2419                  * allocate one and initialize to default values.
2420                  */
2421                 im6o = (struct ip6_moptions *)
2422                         malloc(sizeof(*im6o), M_IP6MOPTS, M_WAITOK);
2423
2424                 if (im6o == NULL)
2425                         return (ENOBUFS);
2426                 *im6op = im6o;
2427                 im6o->im6o_multicast_ifp = NULL;
2428                 im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2429                 im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
2430                 LIST_INIT(&im6o->im6o_memberships);
2431         }
2432
2433         switch (optname) {
2434
2435         case IPV6_MULTICAST_IF:
2436                 /*
2437                  * Select the interface for outgoing multicast packets.
2438                  */
2439                 if (m == NULL || m->m_len != sizeof(u_int)) {
2440                         error = EINVAL;
2441                         break;
2442                 }
2443                 bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
2444                 if (ifindex < 0 || if_index < ifindex) {
2445                         error = ENXIO;  /* XXX EINVAL? */
2446                         break;
2447                 }
2448                 ifp = ifnet_byindex(ifindex);
2449                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
2450                         error = EADDRNOTAVAIL;
2451                         break;
2452                 }
2453                 im6o->im6o_multicast_ifp = ifp;
2454                 break;
2455
2456         case IPV6_MULTICAST_HOPS:
2457             {
2458                 /*
2459                  * Set the IP6 hoplimit for outgoing multicast packets.
2460                  */
2461                 int optval;
2462                 if (m == NULL || m->m_len != sizeof(int)) {
2463                         error = EINVAL;
2464                         break;
2465                 }
2466                 bcopy(mtod(m, u_int *), &optval, sizeof(optval));
2467                 if (optval < -1 || optval >= 256)
2468                         error = EINVAL;
2469                 else if (optval == -1)
2470                         im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2471                 else
2472                         im6o->im6o_multicast_hlim = optval;
2473                 break;
2474             }
2475
2476         case IPV6_MULTICAST_LOOP:
2477                 /*
2478                  * Set the loopback flag for outgoing multicast packets.
2479                  * Must be zero or one.
2480                  */
2481                 if (m == NULL || m->m_len != sizeof(u_int)) {
2482                         error = EINVAL;
2483                         break;
2484                 }
2485                 bcopy(mtod(m, u_int *), &loop, sizeof(loop));
2486                 if (loop > 1) {
2487                         error = EINVAL;
2488                         break;
2489                 }
2490                 im6o->im6o_multicast_loop = loop;
2491                 break;
2492
2493         case IPV6_JOIN_GROUP:
2494                 /*
2495                  * Add a multicast group membership.
2496                  * Group must be a valid IP6 multicast address.
2497                  */
2498                 if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2499                         error = EINVAL;
2500                         break;
2501                 }
2502                 mreq = mtod(m, struct ipv6_mreq *);
2503
2504                 if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2505                         /*
2506                          * We use the unspecified address to specify to accept
2507                          * all multicast addresses. Only super user is allowed
2508                          * to do this.
2509                          */
2510                         if (suser(td)) {
2511                                 error = EACCES;
2512                                 break;
2513                         }
2514                 } else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2515                         error = EINVAL;
2516                         break;
2517                 }
2518
2519                 /*
2520                  * If no interface was explicitly specified, choose an
2521                  * appropriate one according to the given multicast address.
2522                  */
2523                 if (mreq->ipv6mr_interface == 0) {
2524                         struct sockaddr_in6 *dst;
2525
2526                         /*
2527                          * Look up the routing table for the
2528                          * address, and choose the outgoing interface.
2529                          *   XXX: is it a good approach?
2530                          */
2531                         ro.ro_rt = NULL;
2532                         dst = (struct sockaddr_in6 *)&ro.ro_dst;
2533                         bzero(dst, sizeof(*dst));
2534                         dst->sin6_family = AF_INET6;
2535                         dst->sin6_len = sizeof(*dst);
2536                         dst->sin6_addr = mreq->ipv6mr_multiaddr;
2537                         rtalloc((struct route *)&ro);
2538                         if (ro.ro_rt == NULL) {
2539                                 error = EADDRNOTAVAIL;
2540                                 break;
2541                         }
2542                         ifp = ro.ro_rt->rt_ifp;
2543                         RTFREE(ro.ro_rt);
2544                 } else {
2545                         /*
2546                          * If the interface is specified, validate it.
2547                          */
2548                         if (mreq->ipv6mr_interface < 0 ||
2549                             if_index < mreq->ipv6mr_interface) {
2550                                 error = ENXIO;  /* XXX EINVAL? */
2551                                 break;
2552                         }
2553                         ifp = ifnet_byindex(mreq->ipv6mr_interface);
2554                         if (!ifp) {
2555                                 error = ENXIO;  /* XXX EINVAL? */
2556                                 break;
2557                         }
2558                 }
2559
2560                 /*
2561                  * See if we found an interface, and confirm that it
2562                  * supports multicast
2563                  */
2564                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
2565                         error = EADDRNOTAVAIL;
2566                         break;
2567                 }
2568
2569                 if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
2570                         error = EADDRNOTAVAIL; /* XXX: should not happen */
2571                         break;
2572                 }
2573
2574                 /*
2575                  * See if the membership already exists.
2576                  */
2577                 for (imm = im6o->im6o_memberships.lh_first;
2578                      imm != NULL; imm = imm->i6mm_chain.le_next)
2579                         if (imm->i6mm_maddr->in6m_ifp == ifp &&
2580                             IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2581                                                &mreq->ipv6mr_multiaddr))
2582                                 break;
2583                 if (imm != NULL) {
2584                         error = EADDRINUSE;
2585                         break;
2586                 }
2587                 /*
2588                  * Everything looks good; add a new record to the multicast
2589                  * address list for the given interface.
2590                  */
2591                 imm = in6_joingroup(ifp, &mreq->ipv6mr_multiaddr,  &error, 0);
2592                 if (imm == NULL)
2593                         break;
2594                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
2595                 break;
2596
2597         case IPV6_LEAVE_GROUP:
2598                 /*
2599                  * Drop a multicast group membership.
2600                  * Group must be a valid IP6 multicast address.
2601                  */
2602                 if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2603                         error = EINVAL;
2604                         break;
2605                 }
2606                 mreq = mtod(m, struct ipv6_mreq *);
2607
2608                 /*
2609                  * If an interface address was specified, get a pointer
2610                  * to its ifnet structure.
2611                  */
2612                 if (mreq->ipv6mr_interface < 0 ||
2613                     if_index < mreq->ipv6mr_interface) {
2614                         error = ENXIO;  /* XXX EINVAL? */
2615                         break;
2616                 }
2617                 if (mreq->ipv6mr_interface == 0)
2618                         ifp = NULL;
2619                 else
2620                         ifp = ifnet_byindex(mreq->ipv6mr_interface);
2621
2622                 /* Fill in the scope zone ID */
2623                 if (ifp) {
2624                         if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
2625                                 /* XXX: should not happen */
2626                                 error = EADDRNOTAVAIL;
2627                                 break;
2628                         }
2629                 } else if (mreq->ipv6mr_interface != 0) {
2630                         /*
2631                          * This case happens when the (positive) index is in
2632                          * the valid range, but the corresponding interface has
2633                          * been detached dynamically (XXX).
2634                          */
2635                         error = EADDRNOTAVAIL;
2636                         break;
2637                 } else {        /* ipv6mr_interface == 0 */
2638                         struct sockaddr_in6 sa6_mc;
2639
2640                         /*
2641                          * The API spec says as follows:
2642                          *  If the interface index is specified as 0, the
2643                          *  system may choose a multicast group membership to
2644                          *  drop by matching the multicast address only.
2645                          * On the other hand, we cannot disambiguate the scope
2646                          * zone unless an interface is provided.  Thus, we
2647                          * check if there's ambiguity with the default scope
2648                          * zone as the last resort.
2649                          */
2650                         bzero(&sa6_mc, sizeof(sa6_mc));
2651                         sa6_mc.sin6_family = AF_INET6;
2652                         sa6_mc.sin6_len = sizeof(sa6_mc);
2653                         sa6_mc.sin6_addr = mreq->ipv6mr_multiaddr;
2654                         error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
2655                         if (error != 0)
2656                                 break;
2657                         mreq->ipv6mr_multiaddr = sa6_mc.sin6_addr;
2658                 }
2659
2660                 /*
2661                  * Find the membership in the membership list.
2662                  */
2663                 for (imm = im6o->im6o_memberships.lh_first;
2664                      imm != NULL; imm = imm->i6mm_chain.le_next) {
2665                         if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
2666                             IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2667                             &mreq->ipv6mr_multiaddr))
2668                                 break;
2669                 }
2670                 if (imm == NULL) {
2671                         /* Unable to resolve interface */
2672                         error = EADDRNOTAVAIL;
2673                         break;
2674                 }
2675                 /*
2676                  * Give up the multicast address record to which the
2677                  * membership points.
2678                  */
2679                 LIST_REMOVE(imm, i6mm_chain);
2680                 in6_delmulti(imm->i6mm_maddr);
2681                 free(imm, M_IP6MADDR);
2682                 break;
2683
2684         default:
2685                 error = EOPNOTSUPP;
2686                 break;
2687         }
2688
2689         /*
2690          * If all options have default values, no need to keep the mbuf.
2691          */
2692         if (im6o->im6o_multicast_ifp == NULL &&
2693             im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
2694             im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
2695             im6o->im6o_memberships.lh_first == NULL) {
2696                 free(*im6op, M_IP6MOPTS);
2697                 *im6op = NULL;
2698         }
2699
2700         return (error);
2701 }
2702
2703 /*
2704  * Return the IP6 multicast options in response to user getsockopt().
2705  */
2706 static int
2707 ip6_getmoptions(int optname, struct ip6_moptions *im6o, struct mbuf **mp)
2708 {
2709         u_int *hlim, *loop, *ifindex;
2710
2711         *mp = m_get(M_TRYWAIT, MT_HEADER);              /* XXX */
2712
2713         switch (optname) {
2714
2715         case IPV6_MULTICAST_IF:
2716                 ifindex = mtod(*mp, u_int *);
2717                 (*mp)->m_len = sizeof(u_int);
2718                 if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
2719                         *ifindex = 0;
2720                 else
2721                         *ifindex = im6o->im6o_multicast_ifp->if_index;
2722                 return (0);
2723
2724         case IPV6_MULTICAST_HOPS:
2725                 hlim = mtod(*mp, u_int *);
2726                 (*mp)->m_len = sizeof(u_int);
2727                 if (im6o == NULL)
2728                         *hlim = ip6_defmcasthlim;
2729                 else
2730                         *hlim = im6o->im6o_multicast_hlim;
2731                 return (0);
2732
2733         case IPV6_MULTICAST_LOOP:
2734                 loop = mtod(*mp, u_int *);
2735                 (*mp)->m_len = sizeof(u_int);
2736                 if (im6o == NULL)
2737                         *loop = ip6_defmcasthlim;
2738                 else
2739                         *loop = im6o->im6o_multicast_loop;
2740                 return (0);
2741
2742         default:
2743                 return (EOPNOTSUPP);
2744         }
2745 }
2746
2747 /*
2748  * Discard the IP6 multicast options.
2749  */
2750 void
2751 ip6_freemoptions(struct ip6_moptions *im6o)
2752 {
2753         struct in6_multi_mship *imm;
2754
2755         if (im6o == NULL)
2756                 return;
2757
2758         while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
2759                 LIST_REMOVE(imm, i6mm_chain);
2760                 if (imm->i6mm_maddr)
2761                         in6_delmulti(imm->i6mm_maddr);
2762                 free(imm, M_IP6MADDR);
2763         }
2764         free(im6o, M_IP6MOPTS);
2765 }
2766
2767 /*
2768  * Set IPv6 outgoing packet options based on advanced API.
2769  */
2770 int
2771 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2772     struct ip6_pktopts *stickyopt, int priv, int uproto)
2773 {
2774         struct cmsghdr *cm = 0;
2775
2776         if (control == NULL || opt == NULL)
2777                 return (EINVAL);
2778
2779         ip6_initpktopts(opt);
2780         if (stickyopt) {
2781                 int error;
2782
2783                 /*
2784                  * If stickyopt is provided, make a local copy of the options
2785                  * for this particular packet, then override them by ancillary
2786                  * objects.
2787                  * XXX: copypktopts() does not copy the cached route to a next
2788                  * hop (if any).  This is not very good in terms of efficiency,
2789                  * but we can allow this since this option should be rarely
2790                  * used.
2791                  */
2792                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2793                         return (error);
2794         }
2795
2796         /*
2797          * XXX: Currently, we assume all the optional information is stored
2798          * in a single mbuf.
2799          */
2800         if (control->m_next)
2801                 return (EINVAL);
2802
2803         for (; control->m_len; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2804             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2805                 int error;
2806
2807                 if (control->m_len < CMSG_LEN(0))
2808                         return (EINVAL);
2809
2810                 cm = mtod(control, struct cmsghdr *);
2811                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2812                         return (EINVAL);
2813                 if (cm->cmsg_level != IPPROTO_IPV6)
2814                         continue;
2815
2816                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2817                     cm->cmsg_len - CMSG_LEN(0), opt, priv, 0, 1, uproto);
2818                 if (error)
2819                         return (error);
2820         }
2821
2822         return (0);
2823 }
2824
2825 /*
2826  * Set a particular packet option, as a sticky option or an ancillary data
2827  * item.  "len" can be 0 only when it's a sticky option.
2828  * We have 4 cases of combination of "sticky" and "cmsg":
2829  * "sticky=0, cmsg=0": impossible
2830  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2831  * "sticky=1, cmsg=0": RFC3542 socket option
2832  * "sticky=1, cmsg=1": RFC2292 socket option
2833  */
2834 static int
2835 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2836     int priv, int sticky, int cmsg, int uproto)
2837 {
2838         int minmtupolicy, preftemp;
2839
2840         if (!sticky && !cmsg) {
2841 #ifdef DIAGNOSTIC
2842                 printf("ip6_setpktopt: impossible case\n");
2843 #endif
2844                 return (EINVAL);
2845         }
2846
2847         /*
2848          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2849          * not be specified in the context of RFC3542.  Conversely,
2850          * RFC3542 types should not be specified in the context of RFC2292.
2851          */
2852         if (!cmsg) {
2853                 switch (optname) {
2854                 case IPV6_2292PKTINFO:
2855                 case IPV6_2292HOPLIMIT:
2856                 case IPV6_2292NEXTHOP:
2857                 case IPV6_2292HOPOPTS:
2858                 case IPV6_2292DSTOPTS:
2859                 case IPV6_2292RTHDR:
2860                 case IPV6_2292PKTOPTIONS:
2861                         return (ENOPROTOOPT);
2862                 }
2863         }
2864         if (sticky && cmsg) {
2865                 switch (optname) {
2866                 case IPV6_PKTINFO:
2867                 case IPV6_HOPLIMIT:
2868                 case IPV6_NEXTHOP:
2869                 case IPV6_HOPOPTS:
2870                 case IPV6_DSTOPTS:
2871                 case IPV6_RTHDRDSTOPTS:
2872                 case IPV6_RTHDR:
2873                 case IPV6_USE_MIN_MTU:
2874                 case IPV6_DONTFRAG:
2875                 case IPV6_TCLASS:
2876                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2877                         return (ENOPROTOOPT);
2878                 }
2879         }
2880
2881         switch (optname) {
2882         case IPV6_2292PKTINFO:
2883         case IPV6_PKTINFO:
2884         {
2885                 struct ifnet *ifp = NULL;
2886                 struct in6_pktinfo *pktinfo;
2887
2888                 if (len != sizeof(struct in6_pktinfo))
2889                         return (EINVAL);
2890
2891                 pktinfo = (struct in6_pktinfo *)buf;
2892
2893                 /*
2894                  * An application can clear any sticky IPV6_PKTINFO option by
2895                  * doing a "regular" setsockopt with ipi6_addr being
2896                  * in6addr_any and ipi6_ifindex being zero.
2897                  * [RFC 3542, Section 6]
2898                  */
2899                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2900                     pktinfo->ipi6_ifindex == 0 &&
2901                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2902                         ip6_clearpktopts(opt, optname);
2903                         break;
2904                 }
2905
2906                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2907                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2908                         return (EINVAL);
2909                 }
2910
2911                 /* validate the interface index if specified. */
2912                 if (pktinfo->ipi6_ifindex > if_index ||
2913                     pktinfo->ipi6_ifindex < 0) {
2914                          return (ENXIO);
2915                 }
2916                 if (pktinfo->ipi6_ifindex) {
2917                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2918                         if (ifp == NULL)
2919                                 return (ENXIO);
2920                 }
2921
2922                 /*
2923                  * We store the address anyway, and let in6_selectsrc()
2924                  * validate the specified address.  This is because ipi6_addr
2925                  * may not have enough information about its scope zone, and
2926                  * we may need additional information (such as outgoing
2927                  * interface or the scope zone of a destination address) to
2928                  * disambiguate the scope.
2929                  * XXX: the delay of the validation may confuse the
2930                  * application when it is used as a sticky option.
2931                  */
2932                 if (opt->ip6po_pktinfo == NULL) {
2933                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2934                             M_IP6OPT, M_NOWAIT);
2935                         if (opt->ip6po_pktinfo == NULL)
2936                                 return (ENOBUFS);
2937                 }
2938                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2939                 break;
2940         }
2941
2942         case IPV6_2292HOPLIMIT:
2943         case IPV6_HOPLIMIT:
2944         {
2945                 int *hlimp;
2946
2947                 /*
2948                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2949                  * to simplify the ordering among hoplimit options.
2950                  */
2951                 if (optname == IPV6_HOPLIMIT && sticky)
2952                         return (ENOPROTOOPT);
2953
2954                 if (len != sizeof(int))
2955                         return (EINVAL);
2956                 hlimp = (int *)buf;
2957                 if (*hlimp < -1 || *hlimp > 255)
2958                         return (EINVAL);
2959
2960                 opt->ip6po_hlim = *hlimp;
2961                 break;
2962         }
2963
2964         case IPV6_TCLASS:
2965         {
2966                 int tclass;
2967
2968                 if (len != sizeof(int))
2969                         return (EINVAL);
2970                 tclass = *(int *)buf;
2971                 if (tclass < -1 || tclass > 255)
2972                         return (EINVAL);
2973
2974                 opt->ip6po_tclass = tclass;
2975                 break;
2976         }
2977
2978         case IPV6_2292NEXTHOP:
2979         case IPV6_NEXTHOP:
2980                 if (!priv)
2981                         return (EPERM);
2982
2983                 if (len == 0) { /* just remove the option */
2984                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2985                         break;
2986                 }
2987
2988                 /* check if cmsg_len is large enough for sa_len */
2989                 if (len < sizeof(struct sockaddr) || len < *buf)
2990                         return (EINVAL);
2991
2992                 switch (((struct sockaddr *)buf)->sa_family) {
2993                 case AF_INET6:
2994                 {
2995                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2996                         int error;
2997
2998                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
2999                                 return (EINVAL);
3000
3001                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
3002                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
3003                                 return (EINVAL);
3004                         }
3005                         if ((error = sa6_embedscope(sa6, ip6_use_defzone))
3006                             != 0) {
3007                                 return (error);
3008                         }
3009                         break;
3010                 }
3011                 case AF_LINK:   /* should eventually be supported */
3012                 default:
3013                         return (EAFNOSUPPORT);
3014                 }
3015
3016                 /* turn off the previous option, then set the new option. */
3017                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
3018                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
3019                 if (opt->ip6po_nexthop == NULL)
3020                         return (ENOBUFS);
3021                 bcopy(buf, opt->ip6po_nexthop, *buf);
3022                 break;
3023
3024         case IPV6_2292HOPOPTS:
3025         case IPV6_HOPOPTS:
3026         {
3027                 struct ip6_hbh *hbh;
3028                 int hbhlen;
3029
3030                 /*
3031                  * XXX: We don't allow a non-privileged user to set ANY HbH
3032                  * options, since per-option restriction has too much
3033                  * overhead.
3034                  */
3035                 if (!priv)
3036                         return (EPERM);
3037
3038                 if (len == 0) {
3039                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
3040                         break;  /* just remove the option */
3041                 }
3042
3043                 /* message length validation */
3044                 if (len < sizeof(struct ip6_hbh))
3045                         return (EINVAL);
3046                 hbh = (struct ip6_hbh *)buf;
3047                 hbhlen = (hbh->ip6h_len + 1) << 3;
3048                 if (len != hbhlen)
3049                         return (EINVAL);
3050
3051                 /* turn off the previous option, then set the new option. */
3052                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
3053                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
3054                 if (opt->ip6po_hbh == NULL)
3055                         return (ENOBUFS);
3056                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
3057
3058                 break;
3059         }
3060
3061         case IPV6_2292DSTOPTS:
3062         case IPV6_DSTOPTS:
3063         case IPV6_RTHDRDSTOPTS:
3064         {
3065                 struct ip6_dest *dest, **newdest = NULL;
3066                 int destlen;
3067
3068                 if (!priv)      /* XXX: see the comment for IPV6_HOPOPTS */
3069                         return (EPERM);
3070
3071                 if (len == 0) {
3072                         ip6_clearpktopts(opt, optname);
3073                         break;  /* just remove the option */
3074                 }
3075
3076                 /* message length validation */
3077                 if (len < sizeof(struct ip6_dest))
3078                         return (EINVAL);
3079                 dest = (struct ip6_dest *)buf;
3080                 destlen = (dest->ip6d_len + 1) << 3;
3081                 if (len != destlen)
3082                         return (EINVAL);
3083
3084                 /*
3085                  * Determine the position that the destination options header
3086                  * should be inserted; before or after the routing header.
3087                  */
3088                 switch (optname) {
3089                 case IPV6_2292DSTOPTS:
3090                         /*
3091                          * The old advacned API is ambiguous on this point.
3092                          * Our approach is to determine the position based
3093                          * according to the existence of a routing header.
3094                          * Note, however, that this depends on the order of the
3095                          * extension headers in the ancillary data; the 1st
3096                          * part of the destination options header must appear
3097                          * before the routing header in the ancillary data,
3098                          * too.
3099                          * RFC3542 solved the ambiguity by introducing
3100                          * separate ancillary data or option types.
3101                          */
3102                         if (opt->ip6po_rthdr == NULL)
3103                                 newdest = &opt->ip6po_dest1;
3104                         else
3105                                 newdest = &opt->ip6po_dest2;
3106                         break;
3107                 case IPV6_RTHDRDSTOPTS:
3108                         newdest = &opt->ip6po_dest1;
3109                         break;
3110                 case IPV6_DSTOPTS:
3111                         newdest = &opt->ip6po_dest2;
3112                         break;
3113                 }
3114
3115                 /* turn off the previous option, then set the new option. */
3116                 ip6_clearpktopts(opt, optname);
3117                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
3118                 if (*newdest == NULL)
3119                         return (ENOBUFS);
3120                 bcopy(dest, *newdest, destlen);
3121
3122                 break;
3123         }
3124
3125         case IPV6_2292RTHDR:
3126         case IPV6_RTHDR:
3127         {
3128                 struct ip6_rthdr *rth;
3129                 int rthlen;
3130
3131                 if (len == 0) {
3132                         ip6_clearpktopts(opt, IPV6_RTHDR);
3133                         break;  /* just remove the option */
3134                 }
3135
3136                 /* message length validation */
3137                 if (len < sizeof(struct ip6_rthdr))
3138                         return (EINVAL);
3139                 rth = (struct ip6_rthdr *)buf;
3140                 rthlen = (rth->ip6r_len + 1) << 3;
3141                 if (len != rthlen)
3142                         return (EINVAL);
3143
3144                 switch (rth->ip6r_type) {
3145                 case IPV6_RTHDR_TYPE_0:
3146                         if (rth->ip6r_len == 0) /* must contain one addr */
3147                                 return (EINVAL);
3148                         if (rth->ip6r_len % 2) /* length must be even */
3149                                 return (EINVAL);
3150                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
3151                                 return (EINVAL);
3152                         break;
3153                 default:
3154                         return (EINVAL);        /* not supported */
3155                 }
3156
3157                 /* turn off the previous option */
3158                 ip6_clearpktopts(opt, IPV6_RTHDR);
3159                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
3160                 if (opt->ip6po_rthdr == NULL)
3161                         return (ENOBUFS);
3162                 bcopy(rth, opt->ip6po_rthdr, rthlen);
3163
3164                 break;
3165         }
3166
3167         case IPV6_USE_MIN_MTU:
3168                 if (len != sizeof(int))
3169                         return (EINVAL);
3170                 minmtupolicy = *(int *)buf;
3171                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3172                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
3173                     minmtupolicy != IP6PO_MINMTU_ALL) {
3174                         return (EINVAL);
3175                 }
3176                 opt->ip6po_minmtu = minmtupolicy;
3177                 break;
3178
3179         case IPV6_DONTFRAG:
3180                 if (len != sizeof(int))
3181                         return (EINVAL);
3182
3183                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3184                         /*
3185                          * we ignore this option for TCP sockets.
3186                          * (RFC3542 leaves this case unspecified.)
3187                          */
3188                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3189                 } else
3190                         opt->ip6po_flags |= IP6PO_DONTFRAG;
3191                 break;
3192
3193         case IPV6_PREFER_TEMPADDR:
3194                 if (len != sizeof(int))
3195                         return (EINVAL);
3196                 preftemp = *(int *)buf;
3197                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3198                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3199                     preftemp != IP6PO_TEMPADDR_PREFER) {
3200                         return (EINVAL);
3201                 }
3202                 opt->ip6po_prefer_tempaddr = preftemp;
3203                 break;
3204
3205         default:
3206                 return (ENOPROTOOPT);
3207         } /* end of switch */
3208
3209         return (0);
3210 }
3211
3212 /*
3213  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3214  * packet to the input queue of a specified interface.  Note that this
3215  * calls the output routine of the loopback "driver", but with an interface
3216  * pointer that might NOT be &loif -- easier than replicating that code here.
3217  */
3218 void
3219 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
3220 {
3221         struct mbuf *copym;
3222         struct ip6_hdr *ip6;
3223
3224         copym = m_copy(m, 0, M_COPYALL);
3225         if (copym == NULL)
3226                 return;
3227
3228         /*
3229          * Make sure to deep-copy IPv6 header portion in case the data
3230          * is in an mbuf cluster, so that we can safely override the IPv6
3231          * header portion later.
3232          */
3233         if ((copym->m_flags & M_EXT) != 0 ||
3234             copym->m_len < sizeof(struct ip6_hdr)) {
3235                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3236                 if (copym == NULL)
3237                         return;
3238         }
3239
3240 #ifdef DIAGNOSTIC
3241         if (copym->m_len < sizeof(*ip6)) {
3242                 m_freem(copym);
3243                 return;
3244         }
3245 #endif
3246
3247         ip6 = mtod(copym, struct ip6_hdr *);
3248         /*
3249          * clear embedded scope identifiers if necessary.
3250          * in6_clearscope will touch the addresses only when necessary.
3251          */
3252         in6_clearscope(&ip6->ip6_src);
3253         in6_clearscope(&ip6->ip6_dst);
3254
3255         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
3256 }
3257
3258 /*
3259  * Chop IPv6 header off from the payload.
3260  */
3261 static int
3262 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3263 {
3264         struct mbuf *mh;
3265         struct ip6_hdr *ip6;
3266
3267         ip6 = mtod(m, struct ip6_hdr *);
3268         if (m->m_len > sizeof(*ip6)) {
3269                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
3270                 if (mh == 0) {
3271                         m_freem(m);
3272                         return ENOBUFS;
3273                 }
3274                 M_MOVE_PKTHDR(mh, m);
3275                 MH_ALIGN(mh, sizeof(*ip6));
3276                 m->m_len -= sizeof(*ip6);
3277                 m->m_data += sizeof(*ip6);
3278                 mh->m_next = m;
3279                 m = mh;
3280                 m->m_len = sizeof(*ip6);
3281                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3282         }
3283         exthdrs->ip6e_ip6 = m;
3284         return 0;
3285 }
3286
3287 /*
3288  * Compute IPv6 extension header length.
3289  */
3290 int
3291 ip6_optlen(struct in6pcb *in6p)
3292 {
3293         int len;
3294
3295         if (!in6p->in6p_outputopts)
3296                 return 0;
3297
3298         len = 0;
3299 #define elen(x) \
3300     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3301
3302         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3303         if (in6p->in6p_outputopts->ip6po_rthdr)
3304                 /* dest1 is valid with rthdr only */
3305                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3306         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3307         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3308         return len;
3309 #undef elen
3310 }