sys/netinet6/ip6_output.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $    */
   3
   4 /*-
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*-
  34  * Copyright (c) 1982, 1986, 1988, 1990, 1993
  35  *      The Regents of the University of California.  All rights reserved.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in the
  44  *    documentation and/or other materials provided with the distribution.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  62  */
  63
  64 #include "opt_inet.h"
  65 #include "opt_inet6.h"
  66 #include "opt_ipsec.h"
  67
  68 #include <sys/param.h>
  69 #include <sys/malloc.h>
  70 #include <sys/mbuf.h>
  71 #include <sys/proc.h>
  72 #include <sys/errno.h>
  73 #include <sys/priv.h>
  74 #include <sys/protosw.h>
  75 #include <sys/socket.h>
  76 #include <sys/socketvar.h>
  77 #include <sys/kernel.h>
  78
  79 #include <net/if.h>
  80 #include <net/netisr.h>
  81 #include <net/route.h>
  82 #include <net/pfil.h>
  83
  84 #include <netinet/in.h>
  85 #include <netinet/in_var.h>
  86 #include <netinet6/in6_var.h>
  87 #include <netinet/ip6.h>
  88 #include <netinet/icmp6.h>
  89 #include <netinet6/ip6_var.h>
  90 #include <netinet/in_pcb.h>
  91 #include <netinet/tcp_var.h>
  92 #include <netinet6/nd6.h>
  93
  94 #ifdef IPSEC
  95 #include <netipsec/ipsec.h>
  96 #include <netipsec/ipsec6.h>
  97 #include <netipsec/key.h>
  98 #include <netinet6/ip6_ipsec.h>
  99 #endif /* IPSEC */
 100
 101 #include <netinet6/ip6protosw.h>
 102 #include <netinet6/scope6_var.h>
 103
 104 static MALLOC_DEFINE(M_IP6MOPTS, "ip6_moptions", "internet multicast options");
 105
 106 struct ip6_exthdrs {
 107         struct mbuf *ip6e_ip6;
 108         struct mbuf *ip6e_hbh;
 109         struct mbuf *ip6e_dest1;
 110         struct mbuf *ip6e_rthdr;
 111         struct mbuf *ip6e_dest2;
 112 };
 113
 114 static int ip6_pcbopt __P((int, u_char *, int, struct ip6_pktopts **,
 115                            int, int));
 116 static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
 117         struct socket *, struct sockopt *));
 118 static int ip6_getpcbopt __P((struct ip6_pktopts *, int, struct sockopt *));
 119 static int ip6_setpktopt __P((int, u_char *, int, struct ip6_pktopts *, int,
 120         int, int, int));
 121
 122 static int ip6_setmoptions __P((int, struct ip6_moptions **, struct mbuf *));
 123 static int ip6_getmoptions __P((int, struct ip6_moptions *, struct mbuf **));
 124 static int ip6_copyexthdr __P((struct mbuf **, caddr_t, int));
 125 static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
 126         struct ip6_frag **));
 127 static int ip6_insert_jumboopt __P((struct ip6_exthdrs *, u_int32_t));
 128 static int ip6_splithdr __P((struct mbuf *, struct ip6_exthdrs *));
 129 static int ip6_getpmtu __P((struct route_in6 *, struct route_in6 *,
 130         struct ifnet *, struct in6_addr *, u_long *, int *));
 131 static int copypktopts __P((struct ip6_pktopts *, struct ip6_pktopts *, int));
 132
 133
 134 /*
 135  * Make an extension header from option data.  hp is the source, and
 136  * mp is the destination.
 137  */
 138 #define MAKE_EXTHDR(hp, mp)                                             \
 139     do {                                                                \
 140         if (hp) {                                                       \
 141                 struct ip6_ext *eh = (struct ip6_ext *)(hp);            \
 142                 error = ip6_copyexthdr((mp), (caddr_t)(hp),             \
 143                     ((eh)->ip6e_len + 1) << 3);                         \
 144                 if (error)                                              \
 145                         goto freehdrs;                                  \
 146         }                                                               \
 147     } while (/*CONSTCOND*/ 0)
 148
 149 /*
 150  * Form a chain of extension headers.
 151  * m is the extension header mbuf
 152  * mp is the previous mbuf in the chain
 153  * p is the next header
 154  * i is the type of option.
 155  */
 156 #define MAKE_CHAIN(m, mp, p, i)\
 157     do {\
 158         if (m) {\
 159                 if (!hdrsplit) \
 160                         panic("assumption failed: hdr not split"); \
 161                 *mtod((m), u_char *) = *(p);\
 162                 *(p) = (i);\
 163                 p = mtod((m), u_char *);\
 164                 (m)->m_next = (mp)->m_next;\
 165                 (mp)->m_next = (m);\
 166                 (mp) = (m);\
 167         }\
 168     } while (/*CONSTCOND*/ 0)
 169
 170 /*
 171  * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 172  * header (with pri, len, nxt, hlim, src, dst).
 173  * This function may modify ver and hlim only.
 174  * The mbuf chain containing the packet will be freed.
 175  * The mbuf opt, if present, will not be freed.
 176  *
 177  * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
 178  * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 179  * which is rt_rmx.rmx_mtu.
 180  *
 181  * ifpp - XXX: just for statistics
 182  */
 183 int
 184 ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 185     struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
 186     struct ifnet **ifpp, struct inpcb *inp)
 187 {
 188         struct ip6_hdr *ip6, *mhip6;
 189         struct ifnet *ifp, *origifp;
 190         struct mbuf *m = m0;
 191         struct mbuf *mprev = NULL;
 192         int hlen, tlen, len, off;
 193         struct route_in6 ip6route;
 194         struct rtentry *rt = NULL;
 195         struct sockaddr_in6 *dst, src_sa, dst_sa;
 196         struct in6_addr odst;
 197         int error = 0;
 198         struct in6_ifaddr *ia = NULL;
 199         u_long mtu;
 200         int alwaysfrag, dontfrag;
 201         u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
 202         struct ip6_exthdrs exthdrs;
 203         struct in6_addr finaldst, src0, dst0;
 204         u_int32_t zone;
 205         struct route_in6 *ro_pmtu = NULL;
 206         int hdrsplit = 0;
 207         int needipsec = 0;
 208 #ifdef IPSEC
 209         struct ipsec_output_state state;
 210         struct ip6_rthdr *rh = NULL;
 211         int needipsectun = 0;
 212         int segleft_org = 0;
 213         struct secpolicy *sp = NULL;
 214 #endif /* IPSEC */
 215
 216         ip6 = mtod(m, struct ip6_hdr *);
 217         if (ip6 == NULL) {
 218                 printf ("ip6 is NULL");
 219                 goto bad;
 220         }
 221
 222         finaldst = ip6->ip6_dst;
 223
 224         bzero(&exthdrs, sizeof(exthdrs));
 225
 226         if (opt) {
 227                 /* Hop-by-Hop options header */
 228                 MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
 229                 /* Destination options header(1st part) */
 230                 if (opt->ip6po_rthdr) {
 231                         /*
 232                          * Destination options header(1st part)
 233                          * This only makes sense with a routing header.
 234                          * See Section 9.2 of RFC 3542.
 235                          * Disabling this part just for MIP6 convenience is
 236                          * a bad idea.  We need to think carefully about a
 237                          * way to make the advanced API coexist with MIP6
 238                          * options, which might automatically be inserted in
 239                          * the kernel.
 240                          */
 241                         MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
 242                 }
 243                 /* Routing header */
 244                 MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
 245                 /* Destination options header(2nd part) */
 246                 MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
 247         }
 248
 249         /*
 250          * IPSec checking which handles several cases.
 251          * FAST IPSEC: We re-injected the packet.
 252          */
 253 #ifdef IPSEC
 254         switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
 255         {
 256         case 1:                 /* Bad packet */
 257                 goto freehdrs;
 258         case -1:                /* Do IPSec */
 259                 needipsec = 1;
 260         case 0:                 /* No IPSec */
 261         default:
 262                 break;
 263         }
 264 #endif /* IPSEC */
 265
 266         /*
 267          * Calculate the total length of the extension header chain.
 268          * Keep the length of the unfragmentable part for fragmentation.
 269          */
 270         optlen = 0;
 271         if (exthdrs.ip6e_hbh)
 272                 optlen += exthdrs.ip6e_hbh->m_len;
 273         if (exthdrs.ip6e_dest1)
 274                 optlen += exthdrs.ip6e_dest1->m_len;
 275         if (exthdrs.ip6e_rthdr)
 276                 optlen += exthdrs.ip6e_rthdr->m_len;
 277         unfragpartlen = optlen + sizeof(struct ip6_hdr);
 278
 279         /* NOTE: we don't add AH/ESP length here. do that later. */
 280         if (exthdrs.ip6e_dest2)
 281                 optlen += exthdrs.ip6e_dest2->m_len;
 282
 283         /*
 284          * If we need IPsec, or there is at least one extension header,
 285          * separate IP6 header from the payload.
 286          */
 287         if ((needipsec || optlen) && !hdrsplit) {
 288                 if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 289                         m = NULL;
 290                         goto freehdrs;
 291                 }
 292                 m = exthdrs.ip6e_ip6;
 293                 hdrsplit++;
 294         }
 295
 296         /* adjust pointer */
 297         ip6 = mtod(m, struct ip6_hdr *);
 298
 299         /* adjust mbuf packet header length */
 300         m->m_pkthdr.len += optlen;
 301         plen = m->m_pkthdr.len - sizeof(*ip6);
 302
 303         /* If this is a jumbo payload, insert a jumbo payload option. */
 304         if (plen > IPV6_MAXPACKET) {
 305                 if (!hdrsplit) {
 306                         if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
 307                                 m = NULL;
 308                                 goto freehdrs;
 309                         }
 310                         m = exthdrs.ip6e_ip6;
 311                         hdrsplit++;
 312                 }
 313                 /* adjust pointer */
 314                 ip6 = mtod(m, struct ip6_hdr *);
 315                 if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
 316                         goto freehdrs;
 317                 ip6->ip6_plen = 0;
 318         } else
 319                 ip6->ip6_plen = htons(plen);
 320
 321         /*
 322          * Concatenate headers and fill in next header fields.
 323          * Here we have, on "m"
 324          *      IPv6 payload
 325          * and we insert headers accordingly.  Finally, we should be getting:
 326          *      IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
 327          *
 328          * during the header composing process, "m" points to IPv6 header.
 329          * "mprev" points to an extension header prior to esp.
 330          */
 331         u_char *nexthdrp = &ip6->ip6_nxt;
 332         mprev = m;
 333
 334         /*
 335          * we treat dest2 specially.  this makes IPsec processing
 336          * much easier.  the goal here is to make mprev point the
 337          * mbuf prior to dest2.
 338          *
 339          * result: IPv6 dest2 payload
 340          * m and mprev will point to IPv6 header.
 341          */
 342         if (exthdrs.ip6e_dest2) {
 343                 if (!hdrsplit)
 344                         panic("assumption failed: hdr not split");
 345                 exthdrs.ip6e_dest2->m_next = m->m_next;
 346                 m->m_next = exthdrs.ip6e_dest2;
 347                 *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
 348                 ip6->ip6_nxt = IPPROTO_DSTOPTS;
 349         }
 350
 351         /*
 352          * result: IPv6 hbh dest1 rthdr dest2 payload
 353          * m will point to IPv6 header.  mprev will point to the
 354          * extension header prior to dest2 (rthdr in the above case).
 355          */
 356         MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS);
 357         MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp,
 358                    IPPROTO_DSTOPTS);
 359         MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp,
 360                    IPPROTO_ROUTING);
 361
 362 #ifdef IPSEC
 363         if (!needipsec)
 364                 goto skip_ipsec2;
 365
 366         /*
 367          * pointers after IPsec headers are not valid any more.
 368          * other pointers need a great care too.
 369          * (IPsec routines should not mangle mbufs prior to AH/ESP)
 370          */
 371         exthdrs.ip6e_dest2 = NULL;
 372
 373         if (exthdrs.ip6e_rthdr) {
 374                 rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
 375                 segleft_org = rh->ip6r_segleft;
 376                 rh->ip6r_segleft = 0;
 377         }
 378
 379         bzero(&state, sizeof(state));
 380         state.m = m;
 381         error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
 382                                     &needipsectun);
 383         m = state.m;
 384         if (error) {
 385                 /* mbuf is already reclaimed in ipsec6_output_trans. */
 386                 m = NULL;
 387                 switch (error) {
 388                 case EHOSTUNREACH:
 389                 case ENETUNREACH:
 390                 case EMSGSIZE:
 391                 case ENOBUFS:
 392                 case ENOMEM:
 393                         break;
 394                 default:
 395                         printf("ip6_output (ipsec): error code %d\n", error);
 396                         /* FALLTHROUGH */
 397                 case ENOENT:
 398                         /* don't show these error codes to the user */
 399                         error = 0;
 400                         break;
 401                 }
 402                 goto bad;
 403         } else if (!needipsectun) {
 404                 /*
 405                  * In the FAST IPSec case we have already
 406                  * re-injected the packet and it has been freed
 407                  * by the ipsec_done() function.  So, just clean
 408                  * up after ourselves.
 409                  */
 410                 m = NULL;
 411                 goto done;
 412         }
 413         if (exthdrs.ip6e_rthdr) {
 414                 /* ah6_output doesn't modify mbuf chain */
 415                 rh->ip6r_segleft = segleft_org;
 416         }
 417 skip_ipsec2:;
 418 #endif /* IPSEC */
 419
 420         /*
 421          * If there is a routing header, replace the destination address field
 422          * with the first hop of the routing header.
 423          */
 424         if (exthdrs.ip6e_rthdr) {
 425                 struct ip6_rthdr *rh =
 426                         (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
 427                                                   struct ip6_rthdr *));
 428                 struct ip6_rthdr0 *rh0;
 429                 struct in6_addr *addr;
 430                 struct sockaddr_in6 sa;
 431
 432                 switch (rh->ip6r_type) {
 433                 case IPV6_RTHDR_TYPE_0:
 434                          rh0 = (struct ip6_rthdr0 *)rh;
 435                          addr = (struct in6_addr *)(rh0 + 1);
 436
 437                          /*
 438                           * construct a sockaddr_in6 form of
 439                           * the first hop.
 440                           *
 441                           * XXX: we may not have enough
 442                           * information about its scope zone;
 443                           * there is no standard API to pass
 444                           * the information from the
 445                           * application.
 446                           */
 447                          bzero(&sa, sizeof(sa));
 448                          sa.sin6_family = AF_INET6;
 449                          sa.sin6_len = sizeof(sa);
 450                          sa.sin6_addr = addr[0];
 451                          if ((error = sa6_embedscope(&sa,
 452                              ip6_use_defzone)) != 0) {
 453                                  goto bad;
 454                          }
 455                          ip6->ip6_dst = sa.sin6_addr;
 456                          bcopy(&addr[1], &addr[0], sizeof(struct in6_addr)
 457                              * (rh0->ip6r0_segleft - 1));
 458                          addr[rh0->ip6r0_segleft - 1] = finaldst;
 459                          /* XXX */
 460                          in6_clearscope(addr + rh0->ip6r0_segleft - 1);
 461                          break;
 462                 default:        /* is it possible? */
 463                          error = EINVAL;
 464                          goto bad;
 465                 }
 466         }
 467
 468         /* Source address validation */
 469         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
 470             (flags & IPV6_UNSPECSRC) == 0) {
 471                 error = EOPNOTSUPP;
 472                 ip6stat.ip6s_badscope++;
 473                 goto bad;
 474         }
 475         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
 476                 error = EOPNOTSUPP;
 477                 ip6stat.ip6s_badscope++;
 478                 goto bad;
 479         }
 480
 481         ip6stat.ip6s_localout++;
 482
 483         /*
 484          * Route packet.
 485          */
 486         if (ro == 0) {
 487                 ro = &ip6route;
 488                 bzero((caddr_t)ro, sizeof(*ro));
 489         }
 490         ro_pmtu = ro;
 491         if (opt && opt->ip6po_rthdr)
 492                 ro = &opt->ip6po_route;
 493         dst = (struct sockaddr_in6 *)&ro->ro_dst;
 494
 495 again:
 496         /*
 497          * if specified, try to fill in the traffic class field.
 498          * do not override if a non-zero value is already set.
 499          * we check the diffserv field and the ecn field separately.
 500          */
 501         if (opt && opt->ip6po_tclass >= 0) {
 502                 int mask = 0;
 503
 504                 if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
 505                         mask |= 0xfc;
 506                 if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
 507                         mask |= 0x03;
 508                 if (mask != 0)
 509                         ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 20);
 510         }
 511
 512         /* fill in or override the hop limit field, if necessary. */
 513         if (opt && opt->ip6po_hlim != -1)
 514                 ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
 515         else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 516                 if (im6o != NULL)
 517                         ip6->ip6_hlim = im6o->im6o_multicast_hlim;
 518                 else
 519                         ip6->ip6_hlim = ip6_defmcasthlim;
 520         }
 521
 522 #ifdef IPSEC
 523         /*
 524          * We may re-inject packets into the stack here.
 525          */
 526         if (needipsec && needipsectun) {
 527                 struct ipsec_output_state state;
 528
 529                 /*
 530                  * All the extension headers will become inaccessible
 531                  * (since they can be encrypted).
 532                  * Don't panic, we need no more updates to extension headers
 533                  * on inner IPv6 packet (since they are now encapsulated).
 534                  *
 535                  * IPv6 [ESP|AH] IPv6 [extension headers] payload
 536                  */
 537                 bzero(&exthdrs, sizeof(exthdrs));
 538                 exthdrs.ip6e_ip6 = m;
 539
 540                 bzero(&state, sizeof(state));
 541                 state.m = m;
 542                 state.ro = (struct route *)ro;
 543                 state.dst = (struct sockaddr *)dst;
 544
 545                 error = ipsec6_output_tunnel(&state, sp, flags);
 546
 547                 m = state.m;
 548                 ro = (struct route_in6 *)state.ro;
 549                 dst = (struct sockaddr_in6 *)state.dst;
 550                 if (error) {
 551                         /* mbuf is already reclaimed in ipsec6_output_tunnel. */
 552                         m0 = m = NULL;
 553                         m = NULL;
 554                         switch (error) {
 555                         case EHOSTUNREACH:
 556                         case ENETUNREACH:
 557                         case EMSGSIZE:
 558                         case ENOBUFS:
 559                         case ENOMEM:
 560                                 break;
 561                         default:
 562                                 printf("ip6_output (ipsec): error code %d\n", error);
 563                                 /* FALLTHROUGH */
 564                         case ENOENT:
 565                                 /* don't show these error codes to the user */
 566                                 error = 0;
 567                                 break;
 568                         }
 569                         goto bad;
 570                 } else {
 571                         /*
 572                          * In the FAST IPSec case we have already
 573                          * re-injected the packet and it has been freed
 574                          * by the ipsec_done() function.  So, just clean
 575                          * up after ourselves.
 576                          */
 577                         m = NULL;
 578                         goto done;
 579                 }
 580
 581                 exthdrs.ip6e_ip6 = m;
 582         }
 583 #endif /* IPSEC */
 584
 585         /* adjust pointer */
 586         ip6 = mtod(m, struct ip6_hdr *);
 587
 588         bzero(&dst_sa, sizeof(dst_sa));
 589         dst_sa.sin6_family = AF_INET6;
 590         dst_sa.sin6_len = sizeof(dst_sa);
 591         dst_sa.sin6_addr = ip6->ip6_dst;
 592         if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
 593             &ifp, &rt, 0)) != 0) {
 594                 switch (error) {
 595                 case EHOSTUNREACH:
 596                         ip6stat.ip6s_noroute++;
 597                         break;
 598                 case EADDRNOTAVAIL:
 599                 default:
 600                         break; /* XXX statistics? */
 601                 }
 602                 if (ifp != NULL)
 603                         in6_ifstat_inc(ifp, ifs6_out_discard);
 604                 goto bad;
 605         }
 606         if (rt == NULL) {
 607                 /*
 608                  * If in6_selectroute() does not return a route entry,
 609                  * dst may not have been updated.
 610                  */
 611                 *dst = dst_sa;  /* XXX */
 612         }
 613
 614         /*
 615          * then rt (for unicast) and ifp must be non-NULL valid values.
 616          */
 617         if ((flags & IPV6_FORWARDING) == 0) {
 618                 /* XXX: the FORWARDING flag can be set for mrouting. */
 619                 in6_ifstat_inc(ifp, ifs6_out_request);
 620         }
 621         if (rt != NULL) {
 622                 ia = (struct in6_ifaddr *)(rt->rt_ifa);
 623                 rt->rt_use++;
 624         }
 625
 626         /*
 627          * The outgoing interface must be in the zone of source and
 628          * destination addresses.  We should use ia_ifp to support the
 629          * case of sending packets to an address of our own.
 630          */
 631         if (ia != NULL && ia->ia_ifp)
 632                 origifp = ia->ia_ifp;
 633         else
 634                 origifp = ifp;
 635
 636         src0 = ip6->ip6_src;
 637         if (in6_setscope(&src0, origifp, &zone))
 638                 goto badscope;
 639         bzero(&src_sa, sizeof(src_sa));
 640         src_sa.sin6_family = AF_INET6;
 641         src_sa.sin6_len = sizeof(src_sa);
 642         src_sa.sin6_addr = ip6->ip6_src;
 643         if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
 644                 goto badscope;
 645
 646         dst0 = ip6->ip6_dst;
 647         if (in6_setscope(&dst0, origifp, &zone))
 648                 goto badscope;
 649         /* re-initialize to be sure */
 650         bzero(&dst_sa, sizeof(dst_sa));
 651         dst_sa.sin6_family = AF_INET6;
 652         dst_sa.sin6_len = sizeof(dst_sa);
 653         dst_sa.sin6_addr = ip6->ip6_dst;
 654         if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
 655                 goto badscope;
 656         }
 657
 658         /* scope check is done. */
 659         goto routefound;
 660
 661   badscope:
 662         ip6stat.ip6s_badscope++;
 663         in6_ifstat_inc(origifp, ifs6_out_discard);
 664         if (error == 0)
 665                 error = EHOSTUNREACH; /* XXX */
 666         goto bad;
 667
 668   routefound:
 669         if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 670                 if (opt && opt->ip6po_nextroute.ro_rt) {
 671                         /*
 672                          * The nexthop is explicitly specified by the
 673                          * application.  We assume the next hop is an IPv6
 674                          * address.
 675                          */
 676                         dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
 677                 }
 678                 else if ((rt->rt_flags & RTF_GATEWAY))
 679                         dst = (struct sockaddr_in6 *)rt->rt_gateway;
 680         }
 681
 682         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 683                 m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
 684         } else {
 685                 struct  in6_multi *in6m;
 686
 687                 m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST;
 688
 689                 in6_ifstat_inc(ifp, ifs6_out_mcast);
 690
 691                 /*
 692                  * Confirm that the outgoing interface supports multicast.
 693                  */
 694                 if (!(ifp->if_flags & IFF_MULTICAST)) {
 695                         ip6stat.ip6s_noroute++;
 696                         in6_ifstat_inc(ifp, ifs6_out_discard);
 697                         error = ENETUNREACH;
 698                         goto bad;
 699                 }
 700                 IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
 701                 if (in6m != NULL &&
 702                    (im6o == NULL || im6o->im6o_multicast_loop)) {
 703                         /*
 704                          * If we belong to the destination multicast group
 705                          * on the outgoing interface, and the caller did not
 706                          * forbid loopback, loop back a copy.
 707                          */
 708                         ip6_mloopback(ifp, m, dst);
 709                 } else {
 710                         /*
 711                          * If we are acting as a multicast router, perform
 712                          * multicast forwarding as if the packet had just
 713                          * arrived on the interface to which we are about
 714                          * to send.  The multicast forwarding function
 715                          * recursively calls this function, using the
 716                          * IPV6_FORWARDING flag to prevent infinite recursion.
 717                          *
 718                          * Multicasts that are looped back by ip6_mloopback(),
 719                          * above, will be forwarded by the ip6_input() routine,
 720                          * if necessary.
 721                          */
 722                         if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
 723                                 /*
 724                                  * XXX: ip6_mforward expects that rcvif is NULL
 725                                  * when it is called from the originating path.
 726                                  * However, it is not always the case, since
 727                                  * some versions of MGETHDR() does not
 728                                  * initialize the field.
 729                                  */
 730                                 m->m_pkthdr.rcvif = NULL;
 731                                 if (ip6_mforward(ip6, ifp, m) != 0) {
 732                                         m_freem(m);
 733                                         goto done;
 734                                 }
 735                         }
 736                 }
 737                 /*
 738                  * Multicasts with a hoplimit of zero may be looped back,
 739                  * above, but must not be transmitted on a network.
 740                  * Also, multicasts addressed to the loopback interface
 741                  * are not sent -- the above call to ip6_mloopback() will
 742                  * loop back a copy if this host actually belongs to the
 743                  * destination group on the loopback interface.
 744                  */
 745                 if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
 746                     IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
 747                         m_freem(m);
 748                         goto done;
 749                 }
 750         }
 751
 752         /*
 753          * Fill the outgoing inteface to tell the upper layer
 754          * to increment per-interface statistics.
 755          */
 756         if (ifpp)
 757                 *ifpp = ifp;
 758
 759         /* Determine path MTU. */
 760         if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
 761             &alwaysfrag)) != 0)
 762                 goto bad;
 763
 764         /*
 765          * The caller of this function may specify to use the minimum MTU
 766          * in some cases.
 767          * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
 768          * setting.  The logic is a bit complicated; by default, unicast
 769          * packets will follow path MTU while multicast packets will be sent at
 770          * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
 771          * including unicast ones will be sent at the minimum MTU.  Multicast
 772          * packets will always be sent at the minimum MTU unless
 773          * IP6PO_MINMTU_DISABLE is explicitly specified.
 774          * See RFC 3542 for more details.
 775          */
 776         if (mtu > IPV6_MMTU) {
 777                 if ((flags & IPV6_MINMTU))
 778                         mtu = IPV6_MMTU;
 779                 else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
 780                         mtu = IPV6_MMTU;
 781                 else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 782                          (opt == NULL ||
 783                           opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
 784                         mtu = IPV6_MMTU;
 785                 }
 786         }
 787
 788         /*
 789          * clear embedded scope identifiers if necessary.
 790          * in6_clearscope will touch the addresses only when necessary.
 791          */
 792         in6_clearscope(&ip6->ip6_src);
 793         in6_clearscope(&ip6->ip6_dst);
 794
 795         /*
 796          * If the outgoing packet contains a hop-by-hop options header,
 797          * it must be examined and processed even by the source node.
 798          * (RFC 2460, section 4.)
 799          */
 800         if (exthdrs.ip6e_hbh) {
 801                 struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
 802                 u_int32_t dummy; /* XXX unused */
 803                 u_int32_t plen = 0; /* XXX: ip6_process will check the value */
 804
 805 #ifdef DIAGNOSTIC
 806                 if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
 807                         panic("ip6e_hbh is not continuous");
 808 #endif
 809                 /*
 810                  *  XXX: if we have to send an ICMPv6 error to the sender,
 811                  *       we need the M_LOOP flag since icmp6_error() expects
 812                  *       the IPv6 and the hop-by-hop options header are
 813                  *       continuous unless the flag is set.
 814                  */
 815                 m->m_flags |= M_LOOP;
 816                 m->m_pkthdr.rcvif = ifp;
 817                 if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1),
 818                     ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh),
 819                     &dummy, &plen) < 0) {
 820                         /* m was already freed at this point */
 821                         error = EINVAL;/* better error? */
 822                         goto done;
 823                 }
 824                 m->m_flags &= ~M_LOOP; /* XXX */
 825                 m->m_pkthdr.rcvif = NULL;
 826         }
 827
 828         /* Jump over all PFIL processing if hooks are not active. */
 829         if (!PFIL_HOOKED(&inet6_pfil_hook))
 830                 goto passout;
 831
 832         odst = ip6->ip6_dst;
 833         /* Run through list of hooks for output packets. */
 834         error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
 835         if (error != 0 || m == NULL)
 836                 goto done;
 837         ip6 = mtod(m, struct ip6_hdr *);
 838
 839         /* See if destination IP address was changed by packet filter. */
 840         if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
 841                 m->m_flags |= M_SKIP_FIREWALL;
 842                 /* If destination is now ourself drop to ip6_input(). */
 843                 if (in6_localaddr(&ip6->ip6_dst)) {
 844                         if (m->m_pkthdr.rcvif == NULL)
 845                                 m->m_pkthdr.rcvif = loif;
 846                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 847                                 m->m_pkthdr.csum_flags |=
 848                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 849                                 m->m_pkthdr.csum_data = 0xffff;
 850                         }
 851                         m->m_pkthdr.csum_flags |=
 852                             CSUM_IP_CHECKED | CSUM_IP_VALID;
 853                         error = netisr_queue(NETISR_IPV6, m);
 854                         goto done;
 855                 } else
 856                         goto again;     /* Redo the routing table lookup. */
 857         }
 858
 859         /* XXX: IPFIREWALL_FORWARD */
 860
 861 passout:
 862         /*
 863          * Send the packet to the outgoing interface.
 864          * If necessary, do IPv6 fragmentation before sending.
 865          *
 866          * the logic here is rather complex:
 867          * 1: normal case (dontfrag == 0, alwaysfrag == 0)
 868          * 1-a: send as is if tlen <= path mtu
 869          * 1-b: fragment if tlen > path mtu
 870          *
 871          * 2: if user asks us not to fragment (dontfrag == 1)
 872          * 2-a: send as is if tlen <= interface mtu
 873          * 2-b: error if tlen > interface mtu
 874          *
 875          * 3: if we always need to attach fragment header (alwaysfrag == 1)
 876          *      always fragment
 877          *
 878          * 4: if dontfrag == 1 && alwaysfrag == 1
 879          *      error, as we cannot handle this conflicting request
 880          */
 881         tlen = m->m_pkthdr.len;
 882
 883         if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
 884                 dontfrag = 1;
 885         else
 886                 dontfrag = 0;
 887         if (dontfrag && alwaysfrag) {   /* case 4 */
 888                 /* conflicting request - can't transmit */
 889                 error = EMSGSIZE;
 890                 goto bad;
 891         }
 892         if (dontfrag && tlen > IN6_LINKMTU(ifp)) {      /* case 2-b */
 893                 /*
 894                  * Even if the DONTFRAG option is specified, we cannot send the
 895                  * packet when the data length is larger than the MTU of the
 896                  * outgoing interface.
 897                  * Notify the error by sending IPV6_PATHMTU ancillary data as
 898                  * well as returning an error code (the latter is not described
 899                  * in the API spec.)
 900                  */
 901                 u_int32_t mtu32;
 902                 struct ip6ctlparam ip6cp;
 903
 904                 mtu32 = (u_int32_t)mtu;
 905                 bzero(&ip6cp, sizeof(ip6cp));
 906                 ip6cp.ip6c_cmdarg = (void *)&mtu32;
 907                 pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
 908                     (void *)&ip6cp);
 909
 910                 error = EMSGSIZE;
 911                 goto bad;
 912         }
 913
 914         /*
 915          * transmit packet without fragmentation
 916          */
 917         if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* case 1-a and 2-a */
 918                 struct in6_ifaddr *ia6;
 919
 920                 ip6 = mtod(m, struct ip6_hdr *);
 921                 ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
 922                 if (ia6) {
 923                         /* Record statistics for this interface address. */
 924                         ia6->ia_ifa.if_opackets++;
 925                         ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
 926                 }
 927                 error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
 928                 goto done;
 929         }
 930
 931         /*
 932          * try to fragment the packet.  case 1-b and 3
 933          */
 934         if (mtu < IPV6_MMTU) {
 935                 /* path MTU cannot be less than IPV6_MMTU */
 936                 error = EMSGSIZE;
 937                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 938                 goto bad;
 939         } else if (ip6->ip6_plen == 0) {
 940                 /* jumbo payload cannot be fragmented */
 941                 error = EMSGSIZE;
 942                 in6_ifstat_inc(ifp, ifs6_out_fragfail);
 943                 goto bad;
 944         } else {
 945                 struct mbuf **mnext, *m_frgpart;
 946                 struct ip6_frag *ip6f;
 947                 u_int32_t id = htonl(ip6_randomid());
 948                 u_char nextproto;
 949
 950                 int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
 951
 952                 /*
 953                  * Too large for the destination or interface;
 954                  * fragment if possible.
 955                  * Must be able to put at least 8 bytes per fragment.
 956                  */
 957                 hlen = unfragpartlen;
 958                 if (mtu > IPV6_MAXPACKET)
 959                         mtu = IPV6_MAXPACKET;
 960
 961                 len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
 962                 if (len < 8) {
 963                         error = EMSGSIZE;
 964                         in6_ifstat_inc(ifp, ifs6_out_fragfail);
 965                         goto bad;
 966                 }
 967
 968                 /*
 969                  * Verify that we have any chance at all of being able to queue
 970                  *      the packet or packet fragments
 971                  */
 972                 if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
 973                     < tlen  /* - hlen */)) {
 974                         error = ENOBUFS;
 975                         ip6stat.ip6s_odropped++;
 976                         goto bad;
 977                 }
 978
 979                 mnext = &m->m_nextpkt;
 980
 981                 /*
 982                  * Change the next header field of the last header in the
 983                  * unfragmentable part.
 984                  */
 985                 if (exthdrs.ip6e_rthdr) {
 986                         nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
 987                         *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
 988                 } else if (exthdrs.ip6e_dest1) {
 989                         nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
 990                         *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
 991                 } else if (exthdrs.ip6e_hbh) {
 992                         nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
 993                         *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
 994                 } else {
 995                         nextproto = ip6->ip6_nxt;
 996                         ip6->ip6_nxt = IPPROTO_FRAGMENT;
 997                 }
 998
 999                 /*
1000                  * Loop through length of segment after first fragment,
1001                  * make new header and copy data of each part and link onto
1002                  * chain.
1003                  */
1004                 m0 = m;
1005                 for (off = hlen; off < tlen; off += len) {
1006                         MGETHDR(m, M_DONTWAIT, MT_HEADER);
1007                         if (!m) {
1008                                 error = ENOBUFS;
1009                                 ip6stat.ip6s_odropped++;
1010                                 goto sendorfree;
1011                         }
1012                         m->m_pkthdr.rcvif = NULL;
1013                         m->m_flags = m0->m_flags & M_COPYFLAGS;
1014                         *mnext = m;
1015                         mnext = &m->m_nextpkt;
1016                         m->m_data += max_linkhdr;
1017                         mhip6 = mtod(m, struct ip6_hdr *);
1018                         *mhip6 = *ip6;
1019                         m->m_len = sizeof(*mhip6);
1020                         error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
1021                         if (error) {
1022                                 ip6stat.ip6s_odropped++;
1023                                 goto sendorfree;
1024                         }
1025                         ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
1026                         if (off + len >= tlen)
1027                                 len = tlen - off;
1028                         else
1029                                 ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
1030                         mhip6->ip6_plen = htons((u_short)(len + hlen +
1031                             sizeof(*ip6f) - sizeof(struct ip6_hdr)));
1032                         if ((m_frgpart = m_copy(m0, off, len)) == 0) {
1033                                 error = ENOBUFS;
1034                                 ip6stat.ip6s_odropped++;
1035                                 goto sendorfree;
1036                         }
1037                         m_cat(m, m_frgpart);
1038                         m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
1039                         m->m_pkthdr.rcvif = NULL;
1040                         ip6f->ip6f_reserved = 0;
1041                         ip6f->ip6f_ident = id;
1042                         ip6f->ip6f_nxt = nextproto;
1043                         ip6stat.ip6s_ofragments++;
1044                         in6_ifstat_inc(ifp, ifs6_out_fragcreat);
1045                 }
1046
1047                 in6_ifstat_inc(ifp, ifs6_out_fragok);
1048         }
1049
1050         /*
1051          * Remove leading garbages.
1052          */
1053 sendorfree:
1054         m = m0->m_nextpkt;
1055         m0->m_nextpkt = 0;
1056         m_freem(m0);
1057         for (m0 = m; m; m = m0) {
1058                 m0 = m->m_nextpkt;
1059                 m->m_nextpkt = 0;
1060                 if (error == 0) {
1061                         /* Record statistics for this interface address. */
1062                         if (ia) {
1063                                 ia->ia_ifa.if_opackets++;
1064                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1065                         }
1066                         error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
1067                 } else
1068                         m_freem(m);
1069         }
1070
1071         if (error == 0)
1072                 ip6stat.ip6s_fragmented++;
1073
1074 done:
1075         if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
1076                 RTFREE(ro->ro_rt);
1077         } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
1078                 RTFREE(ro_pmtu->ro_rt);
1079         }
1080
1081         return (error);
1082
1083 freehdrs:
1084         m_freem(exthdrs.ip6e_hbh);      /* m_freem will check if mbuf is 0 */
1085         m_freem(exthdrs.ip6e_dest1);
1086         m_freem(exthdrs.ip6e_rthdr);
1087         m_freem(exthdrs.ip6e_dest2);
1088         /* FALLTHROUGH */
1089 bad:
1090         if (m)
1091                 m_freem(m);
1092         goto done;
1093 }
1094
1095 static int
1096 ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
1097 {
1098         struct mbuf *m;
1099
1100         if (hlen > MCLBYTES)
1101                 return (ENOBUFS); /* XXX */
1102
1103         MGET(m, M_DONTWAIT, MT_DATA);
1104         if (!m)
1105                 return (ENOBUFS);
1106
1107         if (hlen > MLEN) {
1108                 MCLGET(m, M_DONTWAIT);
1109                 if ((m->m_flags & M_EXT) == 0) {
1110                         m_free(m);
1111                         return (ENOBUFS);
1112                 }
1113         }
1114         m->m_len = hlen;
1115         if (hdr)
1116                 bcopy(hdr, mtod(m, caddr_t), hlen);
1117
1118         *mp = m;
1119         return (0);
1120 }
1121
1122 /*
1123  * Insert jumbo payload option.
1124  */
1125 static int
1126 ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
1127 {
1128         struct mbuf *mopt;
1129         u_char *optbuf;
1130         u_int32_t v;
1131
1132 #define JUMBOOPTLEN     8       /* length of jumbo payload option and padding */
1133
1134         /*
1135          * If there is no hop-by-hop options header, allocate new one.
1136          * If there is one but it doesn't have enough space to store the
1137          * jumbo payload option, allocate a cluster to store the whole options.
1138          * Otherwise, use it to store the options.
1139          */
1140         if (exthdrs->ip6e_hbh == 0) {
1141                 MGET(mopt, M_DONTWAIT, MT_DATA);
1142                 if (mopt == 0)
1143                         return (ENOBUFS);
1144                 mopt->m_len = JUMBOOPTLEN;
1145                 optbuf = mtod(mopt, u_char *);
1146                 optbuf[1] = 0;  /* = ((JUMBOOPTLEN) >> 3) - 1 */
1147                 exthdrs->ip6e_hbh = mopt;
1148         } else {
1149                 struct ip6_hbh *hbh;
1150
1151                 mopt = exthdrs->ip6e_hbh;
1152                 if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
1153                         /*
1154                          * XXX assumption:
1155                          * - exthdrs->ip6e_hbh is not referenced from places
1156                          *   other than exthdrs.
1157                          * - exthdrs->ip6e_hbh is not an mbuf chain.
1158                          */
1159                         int oldoptlen = mopt->m_len;
1160                         struct mbuf *n;
1161
1162                         /*
1163                          * XXX: give up if the whole (new) hbh header does
1164                          * not fit even in an mbuf cluster.
1165                          */
1166                         if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
1167                                 return (ENOBUFS);
1168
1169                         /*
1170                          * As a consequence, we must always prepare a cluster
1171                          * at this point.
1172                          */
1173                         MGET(n, M_DONTWAIT, MT_DATA);
1174                         if (n) {
1175                                 MCLGET(n, M_DONTWAIT);
1176                                 if ((n->m_flags & M_EXT) == 0) {
1177                                         m_freem(n);
1178                                         n = NULL;
1179                                 }
1180                         }
1181                         if (!n)
1182                                 return (ENOBUFS);
1183                         n->m_len = oldoptlen + JUMBOOPTLEN;
1184                         bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
1185                             oldoptlen);
1186                         optbuf = mtod(n, caddr_t) + oldoptlen;
1187                         m_freem(mopt);
1188                         mopt = exthdrs->ip6e_hbh = n;
1189                 } else {
1190                         optbuf = mtod(mopt, u_char *) + mopt->m_len;
1191                         mopt->m_len += JUMBOOPTLEN;
1192                 }
1193                 optbuf[0] = IP6OPT_PADN;
1194                 optbuf[1] = 1;
1195
1196                 /*
1197                  * Adjust the header length according to the pad and
1198                  * the jumbo payload option.
1199                  */
1200                 hbh = mtod(mopt, struct ip6_hbh *);
1201                 hbh->ip6h_len += (JUMBOOPTLEN >> 3);
1202         }
1203
1204         /* fill in the option. */
1205         optbuf[2] = IP6OPT_JUMBO;
1206         optbuf[3] = 4;
1207         v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
1208         bcopy(&v, &optbuf[4], sizeof(u_int32_t));
1209
1210         /* finally, adjust the packet header length */
1211         exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;
1212
1213         return (0);
1214 #undef JUMBOOPTLEN
1215 }
1216
1217 /*
1218  * Insert fragment header and copy unfragmentable header portions.
1219  */
1220 static int
1221 ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
1222     struct ip6_frag **frghdrp)
1223 {
1224         struct mbuf *n, *mlast;
1225
1226         if (hlen > sizeof(struct ip6_hdr)) {
1227                 n = m_copym(m0, sizeof(struct ip6_hdr),
1228                     hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
1229                 if (n == 0)
1230                         return (ENOBUFS);
1231                 m->m_next = n;
1232         } else
1233                 n = m;
1234
1235         /* Search for the last mbuf of unfragmentable part. */
1236         for (mlast = n; mlast->m_next; mlast = mlast->m_next)
1237                 ;
1238
1239         if ((mlast->m_flags & M_EXT) == 0 &&
1240             M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
1241                 /* use the trailing space of the last mbuf for the fragment hdr */
1242                 *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) +
1243                     mlast->m_len);
1244                 mlast->m_len += sizeof(struct ip6_frag);
1245                 m->m_pkthdr.len += sizeof(struct ip6_frag);
1246         } else {
1247                 /* allocate a new mbuf for the fragment header */
1248                 struct mbuf *mfrg;
1249
1250                 MGET(mfrg, M_DONTWAIT, MT_DATA);
1251                 if (mfrg == 0)
1252                         return (ENOBUFS);
1253                 mfrg->m_len = sizeof(struct ip6_frag);
1254                 *frghdrp = mtod(mfrg, struct ip6_frag *);
1255                 mlast->m_next = mfrg;
1256         }
1257
1258         return (0);
1259 }
1260
1261 static int
1262 ip6_getpmtu(struct route_in6 *ro_pmtu, struct route_in6 *ro,
1263     struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
1264     int *alwaysfragp)
1265 {
1266         u_int32_t mtu = 0;
1267         int alwaysfrag = 0;
1268         int error = 0;
1269
1270         if (ro_pmtu != ro) {
1271                 /* The first hop and the final destination may differ. */
1272                 struct sockaddr_in6 *sa6_dst =
1273                     (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
1274                 if (ro_pmtu->ro_rt &&
1275                     ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 ||
1276                      !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) {
1277                         RTFREE(ro_pmtu->ro_rt);
1278                         ro_pmtu->ro_rt = (struct rtentry *)NULL;
1279                 }
1280                 if (ro_pmtu->ro_rt == NULL) {
1281                         bzero(sa6_dst, sizeof(*sa6_dst));
1282                         sa6_dst->sin6_family = AF_INET6;
1283                         sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
1284                         sa6_dst->sin6_addr = *dst;
1285
1286                         rtalloc((struct route *)ro_pmtu);
1287                 }
1288         }
1289         if (ro_pmtu->ro_rt) {
1290                 u_int32_t ifmtu;
1291                 struct in_conninfo inc;
1292
1293                 bzero(&inc, sizeof(inc));
1294                 inc.inc_flags = 1; /* IPv6 */
1295                 inc.inc6_faddr = *dst;
1296
1297                 if (ifp == NULL)
1298                         ifp = ro_pmtu->ro_rt->rt_ifp;
1299                 ifmtu = IN6_LINKMTU(ifp);
1300                 mtu = tcp_hc_getmtu(&inc);
1301                 if (mtu)
1302                         mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
1303                 else
1304                         mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
1305                 if (mtu == 0)
1306                         mtu = ifmtu;
1307                 else if (mtu < IPV6_MMTU) {
1308                         /*
1309                          * RFC2460 section 5, last paragraph:
1310                          * if we record ICMPv6 too big message with
1311                          * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
1312                          * or smaller, with framgent header attached.
1313                          * (fragment header is needed regardless from the
1314                          * packet size, for translators to identify packets)
1315                          */
1316                         alwaysfrag = 1;
1317                         mtu = IPV6_MMTU;
1318                 } else if (mtu > ifmtu) {
1319                         /*
1320                          * The MTU on the route is larger than the MTU on
1321                          * the interface!  This shouldn't happen, unless the
1322                          * MTU of the interface has been changed after the
1323                          * interface was brought up.  Change the MTU in the
1324                          * route to match the interface MTU (as long as the
1325                          * field isn't locked).
1326                          */
1327                         mtu = ifmtu;
1328                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
1329                 }
1330         } else if (ifp) {
1331                 mtu = IN6_LINKMTU(ifp);
1332         } else
1333                 error = EHOSTUNREACH; /* XXX */
1334
1335         *mtup = mtu;
1336         if (alwaysfragp)
1337                 *alwaysfragp = alwaysfrag;
1338         return (error);
1339 }
1340
1341 /*
1342  * IP6 socket option processing.
1343  */
1344 int
1345 ip6_ctloutput(struct socket *so, struct sockopt *sopt)
1346 {
1347         int privileged, optdatalen, uproto;
1348         void *optdata;
1349         struct inpcb *in6p = sotoinpcb(so);
1350         int error, optval;
1351         int level, op, optname;
1352         int optlen;
1353         struct thread *td;
1354
1355         if (sopt) {
1356                 level = sopt->sopt_level;
1357                 op = sopt->sopt_dir;
1358                 optname = sopt->sopt_name;
1359                 optlen = sopt->sopt_valsize;
1360                 td = sopt->sopt_td;
1361         } else {
1362                 panic("ip6_ctloutput: arg soopt is NULL");
1363         }
1364         error = optval = 0;
1365
1366         privileged = (td == 0 || suser(td)) ? 0 : 1;
1367         uproto = (int)so->so_proto->pr_protocol;
1368
1369         if (level == IPPROTO_IPV6) {
1370                 switch (op) {
1371
1372                 case SOPT_SET:
1373                         switch (optname) {
1374                         case IPV6_2292PKTOPTIONS:
1375 #ifdef IPV6_PKTOPTIONS
1376                         case IPV6_PKTOPTIONS:
1377 #endif
1378                         {
1379                                 struct mbuf *m;
1380
1381                                 error = soopt_getm(sopt, &m); /* XXX */
1382                                 if (error != 0)
1383                                         break;
1384                                 error = soopt_mcopyin(sopt, m); /* XXX */
1385                                 if (error != 0)
1386                                         break;
1387                                 error = ip6_pcbopts(&in6p->in6p_outputopts,
1388                                                     m, so, sopt);
1389                                 m_freem(m); /* XXX */
1390                                 break;
1391                         }
1392
1393                         /*
1394                          * Use of some Hop-by-Hop options or some
1395                          * Destination options, might require special
1396                          * privilege.  That is, normal applications
1397                          * (without special privilege) might be forbidden
1398                          * from setting certain options in outgoing packets,
1399                          * and might never see certain options in received
1400                          * packets. [RFC 2292 Section 6]
1401                          * KAME specific note:
1402                          *  KAME prevents non-privileged users from sending or
1403                          *  receiving ANY hbh/dst options in order to avoid
1404                          *  overhead of parsing options in the kernel.
1405                          */
1406                         case IPV6_RECVHOPOPTS:
1407                         case IPV6_RECVDSTOPTS:
1408                         case IPV6_RECVRTHDRDSTOPTS:
1409                                 if (!privileged) {
1410                                         error = EPERM;
1411                                         break;
1412                                 }
1413                                 /* FALLTHROUGH */
1414                         case IPV6_UNICAST_HOPS:
1415                         case IPV6_HOPLIMIT:
1416                         case IPV6_FAITH:
1417
1418                         case IPV6_RECVPKTINFO:
1419                         case IPV6_RECVHOPLIMIT:
1420                         case IPV6_RECVRTHDR:
1421                         case IPV6_RECVPATHMTU:
1422                         case IPV6_RECVTCLASS:
1423                         case IPV6_V6ONLY:
1424                         case IPV6_AUTOFLOWLABEL:
1425                                 if (optlen != sizeof(int)) {
1426                                         error = EINVAL;
1427                                         break;
1428                                 }
1429                                 error = sooptcopyin(sopt, &optval,
1430                                         sizeof optval, sizeof optval);
1431                                 if (error)
1432                                         break;
1433                                 switch (optname) {
1434
1435                                 case IPV6_UNICAST_HOPS:
1436                                         if (optval < -1 || optval >= 256)
1437                                                 error = EINVAL;
1438                                         else {
1439                                                 /* -1 = kernel default */
1440                                                 in6p->in6p_hops = optval;
1441                                                 if ((in6p->in6p_vflag &
1442                                                      INP_IPV4) != 0)
1443                                                         in6p->inp_ip_ttl = optval;
1444                                         }
1445                                         break;
1446 #define OPTSET(bit) \
1447 do { \
1448         if (optval) \
1449                 in6p->in6p_flags |= (bit); \
1450         else \
1451                 in6p->in6p_flags &= ~(bit); \
1452 } while (/*CONSTCOND*/ 0)
1453 #define OPTSET2292(bit) \
1454 do { \
1455         in6p->in6p_flags |= IN6P_RFC2292; \
1456         if (optval) \
1457                 in6p->in6p_flags |= (bit); \
1458         else \
1459                 in6p->in6p_flags &= ~(bit); \
1460 } while (/*CONSTCOND*/ 0)
1461 #define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)
1462
1463                                 case IPV6_RECVPKTINFO:
1464                                         /* cannot mix with RFC2292 */
1465                                         if (OPTBIT(IN6P_RFC2292)) {
1466                                                 error = EINVAL;
1467                                                 break;
1468                                         }
1469                                         OPTSET(IN6P_PKTINFO);
1470                                         break;
1471
1472                                 case IPV6_HOPLIMIT:
1473                                 {
1474                                         struct ip6_pktopts **optp;
1475
1476                                         /* cannot mix with RFC2292 */
1477                                         if (OPTBIT(IN6P_RFC2292)) {
1478                                                 error = EINVAL;
1479                                                 break;
1480                                         }
1481                                         optp = &in6p->in6p_outputopts;
1482                                         error = ip6_pcbopt(IPV6_HOPLIMIT,
1483                                                            (u_char *)&optval,
1484                                                            sizeof(optval),
1485                                                            optp,
1486                                                            privileged, uproto);
1487                                         break;
1488                                 }
1489
1490                                 case IPV6_RECVHOPLIMIT:
1491                                         /* cannot mix with RFC2292 */
1492                                         if (OPTBIT(IN6P_RFC2292)) {
1493                                                 error = EINVAL;
1494                                                 break;
1495                                         }
1496                                         OPTSET(IN6P_HOPLIMIT);
1497                                         break;
1498
1499                                 case IPV6_RECVHOPOPTS:
1500                                         /* cannot mix with RFC2292 */
1501                                         if (OPTBIT(IN6P_RFC2292)) {
1502                                                 error = EINVAL;
1503                                                 break;
1504                                         }
1505                                         OPTSET(IN6P_HOPOPTS);
1506                                         break;
1507
1508                                 case IPV6_RECVDSTOPTS:
1509                                         /* cannot mix with RFC2292 */
1510                                         if (OPTBIT(IN6P_RFC2292)) {
1511                                                 error = EINVAL;
1512                                                 break;
1513                                         }
1514                                         OPTSET(IN6P_DSTOPTS);
1515                                         break;
1516
1517                                 case IPV6_RECVRTHDRDSTOPTS:
1518                                         /* cannot mix with RFC2292 */
1519                                         if (OPTBIT(IN6P_RFC2292)) {
1520                                                 error = EINVAL;
1521                                                 break;
1522                                         }
1523                                         OPTSET(IN6P_RTHDRDSTOPTS);
1524                                         break;
1525
1526                                 case IPV6_RECVRTHDR:
1527                                         /* cannot mix with RFC2292 */
1528                                         if (OPTBIT(IN6P_RFC2292)) {
1529                                                 error = EINVAL;
1530                                                 break;
1531                                         }
1532                                         OPTSET(IN6P_RTHDR);
1533                                         break;
1534
1535                                 case IPV6_FAITH:
1536                                         OPTSET(IN6P_FAITH);
1537                                         break;
1538
1539                                 case IPV6_RECVPATHMTU:
1540                                         /*
1541                                          * We ignore this option for TCP
1542                                          * sockets.
1543                                          * (RFC3542 leaves this case
1544                                          * unspecified.)
1545                                          */
1546                                         if (uproto != IPPROTO_TCP)
1547                                                 OPTSET(IN6P_MTU);
1548                                         break;
1549
1550                                 case IPV6_V6ONLY:
1551                                         /*
1552                                          * make setsockopt(IPV6_V6ONLY)
1553                                          * available only prior to bind(2).
1554                                          * see ipng mailing list, Jun 22 2001.
1555                                          */
1556                                         if (in6p->in6p_lport ||
1557                                             !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
1558                                                 error = EINVAL;
1559                                                 break;
1560                                         }
1561                                         OPTSET(IN6P_IPV6_V6ONLY);
1562                                         if (optval)
1563                                                 in6p->in6p_vflag &= ~INP_IPV4;
1564                                         else
1565                                                 in6p->in6p_vflag |= INP_IPV4;
1566                                         break;
1567                                 case IPV6_RECVTCLASS:
1568                                         /* cannot mix with RFC2292 XXX */
1569                                         if (OPTBIT(IN6P_RFC2292)) {
1570                                                 error = EINVAL;
1571                                                 break;
1572                                         }
1573                                         OPTSET(IN6P_TCLASS);
1574                                         break;
1575                                 case IPV6_AUTOFLOWLABEL:
1576                                         OPTSET(IN6P_AUTOFLOWLABEL);
1577                                         break;
1578
1579                                 }
1580                                 break;
1581
1582                         case IPV6_TCLASS:
1583                         case IPV6_DONTFRAG:
1584                         case IPV6_USE_MIN_MTU:
1585                         case IPV6_PREFER_TEMPADDR:
1586                                 if (optlen != sizeof(optval)) {
1587                                         error = EINVAL;
1588                                         break;
1589                                 }
1590                                 error = sooptcopyin(sopt, &optval,
1591                                         sizeof optval, sizeof optval);
1592                                 if (error)
1593                                         break;
1594                                 {
1595                                         struct ip6_pktopts **optp;
1596                                         optp = &in6p->in6p_outputopts;
1597                                         error = ip6_pcbopt(optname,
1598                                                            (u_char *)&optval,
1599                                                            sizeof(optval),
1600                                                            optp,
1601                                                            privileged, uproto);
1602                                         break;
1603                                 }
1604
1605                         case IPV6_2292PKTINFO:
1606                         case IPV6_2292HOPLIMIT:
1607                         case IPV6_2292HOPOPTS:
1608                         case IPV6_2292DSTOPTS:
1609                         case IPV6_2292RTHDR:
1610                                 /* RFC 2292 */
1611                                 if (optlen != sizeof(int)) {
1612                                         error = EINVAL;
1613                                         break;
1614                                 }
1615                                 error = sooptcopyin(sopt, &optval,
1616                                         sizeof optval, sizeof optval);
1617                                 if (error)
1618                                         break;
1619                                 switch (optname) {
1620                                 case IPV6_2292PKTINFO:
1621                                         OPTSET2292(IN6P_PKTINFO);
1622                                         break;
1623                                 case IPV6_2292HOPLIMIT:
1624                                         OPTSET2292(IN6P_HOPLIMIT);
1625                                         break;
1626                                 case IPV6_2292HOPOPTS:
1627                                         /*
1628                                          * Check super-user privilege.
1629                                          * See comments for IPV6_RECVHOPOPTS.
1630                                          */
1631                                         if (!privileged)
1632                                                 return (EPERM);
1633                                         OPTSET2292(IN6P_HOPOPTS);
1634                                         break;
1635                                 case IPV6_2292DSTOPTS:
1636                                         if (!privileged)
1637                                                 return (EPERM);
1638                                         OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
1639                                         break;
1640                                 case IPV6_2292RTHDR:
1641                                         OPTSET2292(IN6P_RTHDR);
1642                                         break;
1643                                 }
1644                                 break;
1645                         case IPV6_PKTINFO:
1646                         case IPV6_HOPOPTS:
1647                         case IPV6_RTHDR:
1648                         case IPV6_DSTOPTS:
1649                         case IPV6_RTHDRDSTOPTS:
1650                         case IPV6_NEXTHOP:
1651                         {
1652                                 /* new advanced API (RFC3542) */
1653                                 u_char *optbuf;
1654                                 u_char optbuf_storage[MCLBYTES];
1655                                 int optlen;
1656                                 struct ip6_pktopts **optp;
1657
1658                                 /* cannot mix with RFC2292 */
1659                                 if (OPTBIT(IN6P_RFC2292)) {
1660                                         error = EINVAL;
1661                                         break;
1662                                 }
1663
1664                                 /*
1665                                  * We only ensure valsize is not too large
1666                                  * here.  Further validation will be done
1667                                  * later.
1668                                  */
1669                                 error = sooptcopyin(sopt, optbuf_storage,
1670                                     sizeof(optbuf_storage), 0);
1671                                 if (error)
1672                                         break;
1673                                 optlen = sopt->sopt_valsize;
1674                                 optbuf = optbuf_storage;
1675                                 optp = &in6p->in6p_outputopts;
1676                                 error = ip6_pcbopt(optname,
1677                                                    optbuf, optlen,
1678                                                    optp, privileged, uproto);
1679                                 break;
1680                         }
1681 #undef OPTSET
1682
1683                         case IPV6_MULTICAST_IF:
1684                         case IPV6_MULTICAST_HOPS:
1685                         case IPV6_MULTICAST_LOOP:
1686                         case IPV6_JOIN_GROUP:
1687                         case IPV6_LEAVE_GROUP:
1688                             {
1689                                 if (sopt->sopt_valsize > MLEN) {
1690                                         error = EMSGSIZE;
1691                                         break;
1692                                 }
1693                                 /* XXX */
1694                             }
1695                             /* FALLTHROUGH */
1696                             {
1697                                 struct mbuf *m;
1698
1699                                 if (sopt->sopt_valsize > MCLBYTES) {
1700                                         error = EMSGSIZE;
1701                                         break;
1702                                 }
1703                                 /* XXX */
1704                                 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
1705                                 if (m == 0) {
1706                                         error = ENOBUFS;
1707                                         break;
1708                                 }
1709                                 if (sopt->sopt_valsize > MLEN) {
1710                                         MCLGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT);
1711                                         if ((m->m_flags & M_EXT) == 0) {
1712                                                 m_free(m);
1713                                                 error = ENOBUFS;
1714                                                 break;
1715                                         }
1716                                 }
1717                                 m->m_len = sopt->sopt_valsize;
1718                                 error = sooptcopyin(sopt, mtod(m, char *),
1719                                                     m->m_len, m->m_len);
1720                                 if (error) {
1721                                         (void)m_free(m);
1722                                         break;
1723                                 }
1724                                 error = ip6_setmoptions(sopt->sopt_name,
1725                                                         &in6p->in6p_moptions,
1726                                                         m);
1727                                 (void)m_free(m);
1728                             }
1729                                 break;
1730
1731                         case IPV6_PORTRANGE:
1732                                 error = sooptcopyin(sopt, &optval,
1733                                     sizeof optval, sizeof optval);
1734                                 if (error)
1735                                         break;
1736
1737                                 switch (optval) {
1738                                 case IPV6_PORTRANGE_DEFAULT:
1739                                         in6p->in6p_flags &= ~(IN6P_LOWPORT);
1740                                         in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1741                                         break;
1742
1743                                 case IPV6_PORTRANGE_HIGH:
1744                                         in6p->in6p_flags &= ~(IN6P_LOWPORT);
1745                                         in6p->in6p_flags |= IN6P_HIGHPORT;
1746                                         break;
1747
1748                                 case IPV6_PORTRANGE_LOW:
1749                                         in6p->in6p_flags &= ~(IN6P_HIGHPORT);
1750                                         in6p->in6p_flags |= IN6P_LOWPORT;
1751                                         break;
1752
1753                                 default:
1754                                         error = EINVAL;
1755                                         break;
1756                                 }
1757                                 break;
1758
1759 #ifdef IPSEC
1760                         case IPV6_IPSEC_POLICY:
1761                             {
1762                                 caddr_t req = NULL;
1763                                 size_t len = 0;
1764                                 struct mbuf *m;
1765
1766                                 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1767                                         break;
1768                                 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1769                                         break;
1770                                 if (m) {
1771                                         req = mtod(m, caddr_t);
1772                                         len = m->m_len;
1773                                 }
1774                                 error = ipsec6_set_policy(in6p, optname, req,
1775                                                           len, privileged);
1776                                 m_freem(m);
1777                             }
1778                                 break;
1779 #endif /* IPSEC */
1780
1781                         default:
1782                                 error = ENOPROTOOPT;
1783                                 break;
1784                         }
1785                         break;
1786
1787                 case SOPT_GET:
1788                         switch (optname) {
1789
1790                         case IPV6_2292PKTOPTIONS:
1791 #ifdef IPV6_PKTOPTIONS
1792                         case IPV6_PKTOPTIONS:
1793 #endif
1794                                 /*
1795                                  * RFC3542 (effectively) deprecated the
1796                                  * semantics of the 2292-style pktoptions.
1797                                  * Since it was not reliable in nature (i.e.,
1798                                  * applications had to expect the lack of some
1799                                  * information after all), it would make sense
1800                                  * to simplify this part by always returning
1801                                  * empty data.
1802                                  */
1803                                 sopt->sopt_valsize = 0;
1804                                 break;
1805
1806                         case IPV6_RECVHOPOPTS:
1807                         case IPV6_RECVDSTOPTS:
1808                         case IPV6_RECVRTHDRDSTOPTS:
1809                         case IPV6_UNICAST_HOPS:
1810                         case IPV6_RECVPKTINFO:
1811                         case IPV6_RECVHOPLIMIT:
1812                         case IPV6_RECVRTHDR:
1813                         case IPV6_RECVPATHMTU:
1814
1815                         case IPV6_FAITH:
1816                         case IPV6_V6ONLY:
1817                         case IPV6_PORTRANGE:
1818                         case IPV6_RECVTCLASS:
1819                         case IPV6_AUTOFLOWLABEL:
1820                                 switch (optname) {
1821
1822                                 case IPV6_RECVHOPOPTS:
1823                                         optval = OPTBIT(IN6P_HOPOPTS);
1824                                         break;
1825
1826                                 case IPV6_RECVDSTOPTS:
1827                                         optval = OPTBIT(IN6P_DSTOPTS);
1828                                         break;
1829
1830                                 case IPV6_RECVRTHDRDSTOPTS:
1831                                         optval = OPTBIT(IN6P_RTHDRDSTOPTS);
1832                                         break;
1833
1834                                 case IPV6_UNICAST_HOPS:
1835                                         optval = in6p->in6p_hops;
1836                                         break;
1837
1838                                 case IPV6_RECVPKTINFO:
1839                                         optval = OPTBIT(IN6P_PKTINFO);
1840                                         break;
1841
1842                                 case IPV6_RECVHOPLIMIT:
1843                                         optval = OPTBIT(IN6P_HOPLIMIT);
1844                                         break;
1845
1846                                 case IPV6_RECVRTHDR:
1847                                         optval = OPTBIT(IN6P_RTHDR);
1848                                         break;
1849
1850                                 case IPV6_RECVPATHMTU:
1851                                         optval = OPTBIT(IN6P_MTU);
1852                                         break;
1853
1854                                 case IPV6_FAITH:
1855                                         optval = OPTBIT(IN6P_FAITH);
1856                                         break;
1857
1858                                 case IPV6_V6ONLY:
1859                                         optval = OPTBIT(IN6P_IPV6_V6ONLY);
1860                                         break;
1861
1862                                 case IPV6_PORTRANGE:
1863                                     {
1864                                         int flags;
1865                                         flags = in6p->in6p_flags;
1866                                         if (flags & IN6P_HIGHPORT)
1867                                                 optval = IPV6_PORTRANGE_HIGH;
1868                                         else if (flags & IN6P_LOWPORT)
1869                                                 optval = IPV6_PORTRANGE_LOW;
1870                                         else
1871                                                 optval = 0;
1872                                         break;
1873                                     }
1874                                 case IPV6_RECVTCLASS:
1875                                         optval = OPTBIT(IN6P_TCLASS);
1876                                         break;
1877
1878                                 case IPV6_AUTOFLOWLABEL:
1879                                         optval = OPTBIT(IN6P_AUTOFLOWLABEL);
1880                                         break;
1881                                 }
1882                                 if (error)
1883                                         break;
1884                                 error = sooptcopyout(sopt, &optval,
1885                                         sizeof optval);
1886                                 break;
1887
1888                         case IPV6_PATHMTU:
1889                         {
1890                                 u_long pmtu = 0;
1891                                 struct ip6_mtuinfo mtuinfo;
1892                                 struct route_in6 sro;
1893
1894                                 bzero(&sro, sizeof(sro));
1895
1896                                 if (!(so->so_state & SS_ISCONNECTED))
1897                                         return (ENOTCONN);
1898                                 /*
1899                                  * XXX: we dot not consider the case of source
1900                                  * routing, or optional information to specify
1901                                  * the outgoing interface.
1902                                  */
1903                                 error = ip6_getpmtu(&sro, NULL, NULL,
1904                                     &in6p->in6p_faddr, &pmtu, NULL);
1905                                 if (sro.ro_rt)
1906                                         RTFREE(sro.ro_rt);
1907                                 if (error)
1908                                         break;
1909                                 if (pmtu > IPV6_MAXPACKET)
1910                                         pmtu = IPV6_MAXPACKET;
1911
1912                                 bzero(&mtuinfo, sizeof(mtuinfo));
1913                                 mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
1914                                 optdata = (void *)&mtuinfo;
1915                                 optdatalen = sizeof(mtuinfo);
1916                                 error = sooptcopyout(sopt, optdata,
1917                                     optdatalen);
1918                                 break;
1919                         }
1920
1921                         case IPV6_2292PKTINFO:
1922                         case IPV6_2292HOPLIMIT:
1923                         case IPV6_2292HOPOPTS:
1924                         case IPV6_2292RTHDR:
1925                         case IPV6_2292DSTOPTS:
1926                                 switch (optname) {
1927                                 case IPV6_2292PKTINFO:
1928                                         optval = OPTBIT(IN6P_PKTINFO);
1929                                         break;
1930                                 case IPV6_2292HOPLIMIT:
1931                                         optval = OPTBIT(IN6P_HOPLIMIT);
1932                                         break;
1933                                 case IPV6_2292HOPOPTS:
1934                                         optval = OPTBIT(IN6P_HOPOPTS);
1935                                         break;
1936                                 case IPV6_2292RTHDR:
1937                                         optval = OPTBIT(IN6P_RTHDR);
1938                                         break;
1939                                 case IPV6_2292DSTOPTS:
1940                                         optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
1941                                         break;
1942                                 }
1943                                 error = sooptcopyout(sopt, &optval,
1944                                     sizeof optval);
1945                                 break;
1946                         case IPV6_PKTINFO:
1947                         case IPV6_HOPOPTS:
1948                         case IPV6_RTHDR:
1949                         case IPV6_DSTOPTS:
1950                         case IPV6_RTHDRDSTOPTS:
1951                         case IPV6_NEXTHOP:
1952                         case IPV6_TCLASS:
1953                         case IPV6_DONTFRAG:
1954                         case IPV6_USE_MIN_MTU:
1955                         case IPV6_PREFER_TEMPADDR:
1956                                 error = ip6_getpcbopt(in6p->in6p_outputopts,
1957                                     optname, sopt);
1958                                 break;
1959
1960                         case IPV6_MULTICAST_IF:
1961                         case IPV6_MULTICAST_HOPS:
1962                         case IPV6_MULTICAST_LOOP:
1963                         case IPV6_JOIN_GROUP:
1964                         case IPV6_LEAVE_GROUP:
1965                             {
1966                                 struct mbuf *m;
1967                                 error = ip6_getmoptions(sopt->sopt_name,
1968                                     in6p->in6p_moptions, &m);
1969                                 if (error == 0)
1970                                         error = sooptcopyout(sopt,
1971                                             mtod(m, char *), m->m_len);
1972                                 m_freem(m);
1973                             }
1974                                 break;
1975
1976 #ifdef IPSEC
1977                         case IPV6_IPSEC_POLICY:
1978                           {
1979                                 caddr_t req = NULL;
1980                                 size_t len = 0;
1981                                 struct mbuf *m = NULL;
1982                                 struct mbuf **mp = &m;
1983                                 size_t ovalsize = sopt->sopt_valsize;
1984                                 caddr_t oval = (caddr_t)sopt->sopt_val;
1985
1986                                 error = soopt_getm(sopt, &m); /* XXX */
1987                                 if (error != 0)
1988                                         break;
1989                                 error = soopt_mcopyin(sopt, m); /* XXX */
1990                                 if (error != 0)
1991                                         break;
1992                                 sopt->sopt_valsize = ovalsize;
1993                                 sopt->sopt_val = oval;
1994                                 if (m) {
1995                                         req = mtod(m, caddr_t);
1996                                         len = m->m_len;
1997                                 }
1998                                 error = ipsec6_get_policy(in6p, req, len, mp);
1999                                 if (error == 0)
2000                                         error = soopt_mcopyout(sopt, m); /* XXX */
2001                                 if (error == 0 && m)
2002                                         m_freem(m);
2003                                 break;
2004                           }
2005 #endif /* IPSEC */
2006
2007                         default:
2008                                 error = ENOPROTOOPT;
2009                                 break;
2010                         }
2011                         break;
2012                 }
2013         } else {                /* level != IPPROTO_IPV6 */
2014                 error = EINVAL;
2015         }
2016         return (error);
2017 }
2018
2019 int
2020 ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
2021 {
2022         int error = 0, optval, optlen;
2023         const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
2024         struct in6pcb *in6p = sotoin6pcb(so);
2025         int level, op, optname;
2026
2027         if (sopt) {
2028                 level = sopt->sopt_level;
2029                 op = sopt->sopt_dir;
2030                 optname = sopt->sopt_name;
2031                 optlen = sopt->sopt_valsize;
2032         } else
2033                 panic("ip6_raw_ctloutput: arg soopt is NULL");
2034
2035         if (level != IPPROTO_IPV6) {
2036                 return (EINVAL);
2037         }
2038
2039         switch (optname) {
2040         case IPV6_CHECKSUM:
2041                 /*
2042                  * For ICMPv6 sockets, no modification allowed for checksum
2043                  * offset, permit "no change" values to help existing apps.
2044                  *
2045                  * RFC3542 says: "An attempt to set IPV6_CHECKSUM
2046                  * for an ICMPv6 socket will fail."
2047                  * The current behavior does not meet RFC3542.
2048                  */
2049                 switch (op) {
2050                 case SOPT_SET:
2051                         if (optlen != sizeof(int)) {
2052                                 error = EINVAL;
2053                                 break;
2054                         }
2055                         error = sooptcopyin(sopt, &optval, sizeof(optval),
2056                                             sizeof(optval));
2057                         if (error)
2058                                 break;
2059                         if ((optval % 2) != 0) {
2060                                 /* the API assumes even offset values */
2061                                 error = EINVAL;
2062                         } else if (so->so_proto->pr_protocol ==
2063                             IPPROTO_ICMPV6) {
2064                                 if (optval != icmp6off)
2065                                         error = EINVAL;
2066                         } else
2067                                 in6p->in6p_cksum = optval;
2068                         break;
2069
2070                 case SOPT_GET:
2071                         if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
2072                                 optval = icmp6off;
2073                         else
2074                                 optval = in6p->in6p_cksum;
2075
2076                         error = sooptcopyout(sopt, &optval, sizeof(optval));
2077                         break;
2078
2079                 default:
2080                         error = EINVAL;
2081                         break;
2082                 }
2083                 break;
2084
2085         default:
2086                 error = ENOPROTOOPT;
2087                 break;
2088         }
2089
2090         return (error);
2091 }
2092
2093 /*
2094  * Set up IP6 options in pcb for insertion in output packets or
2095  * specifying behavior of outgoing packets.
2096  */
2097 static int
2098 ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
2099     struct socket *so, struct sockopt *sopt)
2100 {
2101         struct ip6_pktopts *opt = *pktopt;
2102         int error = 0;
2103         struct thread *td = sopt->sopt_td;
2104         int priv = 0;
2105
2106         /* turn off any old options. */
2107         if (opt) {
2108 #ifdef DIAGNOSTIC
2109                 if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
2110                     opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
2111                     opt->ip6po_rhinfo.ip6po_rhi_rthdr)
2112                         printf("ip6_pcbopts: all specified options are cleared.\n");
2113 #endif
2114                 ip6_clearpktopts(opt, -1);
2115         } else
2116                 opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
2117         *pktopt = NULL;
2118
2119         if (!m || m->m_len == 0) {
2120                 /*
2121                  * Only turning off any previous options, regardless of
2122                  * whether the opt is just created or given.
2123                  */
2124                 free(opt, M_IP6OPT);
2125                 return (0);
2126         }
2127
2128         /*  set options specified by user. */
2129         if (td && !suser(td))
2130                 priv = 1;
2131         if ((error = ip6_setpktopts(m, opt, NULL, priv,
2132             so->so_proto->pr_protocol)) != 0) {
2133                 ip6_clearpktopts(opt, -1); /* XXX: discard all options */
2134                 free(opt, M_IP6OPT);
2135                 return (error);
2136         }
2137         *pktopt = opt;
2138         return (0);
2139 }
2140
2141 /*
2142  * initialize ip6_pktopts.  beware that there are non-zero default values in
2143  * the struct.
2144  */
2145 void
2146 ip6_initpktopts(struct ip6_pktopts *opt)
2147 {
2148
2149         bzero(opt, sizeof(*opt));
2150         opt->ip6po_hlim = -1;   /* -1 means default hop limit */
2151         opt->ip6po_tclass = -1; /* -1 means default traffic class */
2152         opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
2153         opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
2154 }
2155
2156 static int
2157 ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
2158     int priv, int uproto)
2159 {
2160         struct ip6_pktopts *opt;
2161
2162         if (*pktopt == NULL) {
2163                 *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
2164                     M_WAITOK);
2165                 ip6_initpktopts(*pktopt);
2166         }
2167         opt = *pktopt;
2168
2169         return (ip6_setpktopt(optname, buf, len, opt, priv, 1, 0, uproto));
2170 }
2171
2172 static int
2173 ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
2174 {
2175         void *optdata = NULL;
2176         int optdatalen = 0;
2177         struct ip6_ext *ip6e;
2178         int error = 0;
2179         struct in6_pktinfo null_pktinfo;
2180         int deftclass = 0, on;
2181         int defminmtu = IP6PO_MINMTU_MCASTONLY;
2182         int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
2183
2184         switch (optname) {
2185         case IPV6_PKTINFO:
2186                 if (pktopt && pktopt->ip6po_pktinfo)
2187                         optdata = (void *)pktopt->ip6po_pktinfo;
2188                 else {
2189                         /* XXX: we don't have to do this every time... */
2190                         bzero(&null_pktinfo, sizeof(null_pktinfo));
2191                         optdata = (void *)&null_pktinfo;
2192                 }
2193                 optdatalen = sizeof(struct in6_pktinfo);
2194                 break;
2195         case IPV6_TCLASS:
2196                 if (pktopt && pktopt->ip6po_tclass >= 0)
2197                         optdata = (void *)&pktopt->ip6po_tclass;
2198                 else
2199                         optdata = (void *)&deftclass;
2200                 optdatalen = sizeof(int);
2201                 break;
2202         case IPV6_HOPOPTS:
2203                 if (pktopt && pktopt->ip6po_hbh) {
2204                         optdata = (void *)pktopt->ip6po_hbh;
2205                         ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
2206                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2207                 }
2208                 break;
2209         case IPV6_RTHDR:
2210                 if (pktopt && pktopt->ip6po_rthdr) {
2211                         optdata = (void *)pktopt->ip6po_rthdr;
2212                         ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
2213                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2214                 }
2215                 break;
2216         case IPV6_RTHDRDSTOPTS:
2217                 if (pktopt && pktopt->ip6po_dest1) {
2218                         optdata = (void *)pktopt->ip6po_dest1;
2219                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
2220                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2221                 }
2222                 break;
2223         case IPV6_DSTOPTS:
2224                 if (pktopt && pktopt->ip6po_dest2) {
2225                         optdata = (void *)pktopt->ip6po_dest2;
2226                         ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
2227                         optdatalen = (ip6e->ip6e_len + 1) << 3;
2228                 }
2229                 break;
2230         case IPV6_NEXTHOP:
2231                 if (pktopt && pktopt->ip6po_nexthop) {
2232                         optdata = (void *)pktopt->ip6po_nexthop;
2233                         optdatalen = pktopt->ip6po_nexthop->sa_len;
2234                 }
2235                 break;
2236         case IPV6_USE_MIN_MTU:
2237                 if (pktopt)
2238                         optdata = (void *)&pktopt->ip6po_minmtu;
2239                 else
2240                         optdata = (void *)&defminmtu;
2241                 optdatalen = sizeof(int);
2242                 break;
2243         case IPV6_DONTFRAG:
2244                 if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
2245                         on = 1;
2246                 else
2247                         on = 0;
2248                 optdata = (void *)&on;
2249                 optdatalen = sizeof(on);
2250                 break;
2251         case IPV6_PREFER_TEMPADDR:
2252                 if (pktopt)
2253                         optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
2254                 else
2255                         optdata = (void *)&defpreftemp;
2256                 optdatalen = sizeof(int);
2257                 break;
2258         default:                /* should not happen */
2259 #ifdef DIAGNOSTIC
2260                 panic("ip6_getpcbopt: unexpected option\n");
2261 #endif
2262                 return (ENOPROTOOPT);
2263         }
2264
2265         error = sooptcopyout(sopt, optdata, optdatalen);
2266
2267         return (error);
2268 }
2269
2270 void
2271 ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
2272 {
2273         if (pktopt == NULL)
2274                 return;
2275
2276         if (optname == -1 || optname == IPV6_PKTINFO) {
2277                 if (pktopt->ip6po_pktinfo)
2278                         free(pktopt->ip6po_pktinfo, M_IP6OPT);
2279                 pktopt->ip6po_pktinfo = NULL;
2280         }
2281         if (optname == -1 || optname == IPV6_HOPLIMIT)
2282                 pktopt->ip6po_hlim = -1;
2283         if (optname == -1 || optname == IPV6_TCLASS)
2284                 pktopt->ip6po_tclass = -1;
2285         if (optname == -1 || optname == IPV6_NEXTHOP) {
2286                 if (pktopt->ip6po_nextroute.ro_rt) {
2287                         RTFREE(pktopt->ip6po_nextroute.ro_rt);
2288                         pktopt->ip6po_nextroute.ro_rt = NULL;
2289                 }
2290                 if (pktopt->ip6po_nexthop)
2291                         free(pktopt->ip6po_nexthop, M_IP6OPT);
2292                 pktopt->ip6po_nexthop = NULL;
2293         }
2294         if (optname == -1 || optname == IPV6_HOPOPTS) {
2295                 if (pktopt->ip6po_hbh)
2296                         free(pktopt->ip6po_hbh, M_IP6OPT);
2297                 pktopt->ip6po_hbh = NULL;
2298         }
2299         if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
2300                 if (pktopt->ip6po_dest1)
2301                         free(pktopt->ip6po_dest1, M_IP6OPT);
2302                 pktopt->ip6po_dest1 = NULL;
2303         }
2304         if (optname == -1 || optname == IPV6_RTHDR) {
2305                 if (pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
2306                         free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
2307                 pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
2308                 if (pktopt->ip6po_route.ro_rt) {
2309                         RTFREE(pktopt->ip6po_route.ro_rt);
2310                         pktopt->ip6po_route.ro_rt = NULL;
2311                 }
2312         }
2313         if (optname == -1 || optname == IPV6_DSTOPTS) {
2314                 if (pktopt->ip6po_dest2)
2315                         free(pktopt->ip6po_dest2, M_IP6OPT);
2316                 pktopt->ip6po_dest2 = NULL;
2317         }
2318 }
2319
2320 #define PKTOPT_EXTHDRCPY(type) \
2321 do {\
2322         if (src->type) {\
2323                 int hlen = (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
2324                 dst->type = malloc(hlen, M_IP6OPT, canwait);\
2325                 if (dst->type == NULL && canwait == M_NOWAIT)\
2326                         goto bad;\
2327                 bcopy(src->type, dst->type, hlen);\
2328         }\
2329 } while (/*CONSTCOND*/ 0)
2330
2331 static int
2332 copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
2333 {
2334         if (dst == NULL || src == NULL)  {
2335                 printf("ip6_clearpktopts: invalid argument\n");
2336                 return (EINVAL);
2337         }
2338
2339         dst->ip6po_hlim = src->ip6po_hlim;
2340         dst->ip6po_tclass = src->ip6po_tclass;
2341         dst->ip6po_flags = src->ip6po_flags;
2342         if (src->ip6po_pktinfo) {
2343                 dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
2344                     M_IP6OPT, canwait);
2345                 if (dst->ip6po_pktinfo == NULL)
2346                         goto bad;
2347                 *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
2348         }
2349         if (src->ip6po_nexthop) {
2350                 dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
2351                     M_IP6OPT, canwait);
2352                 if (dst->ip6po_nexthop == NULL)
2353                         goto bad;
2354                 bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
2355                     src->ip6po_nexthop->sa_len);
2356         }
2357         PKTOPT_EXTHDRCPY(ip6po_hbh);
2358         PKTOPT_EXTHDRCPY(ip6po_dest1);
2359         PKTOPT_EXTHDRCPY(ip6po_dest2);
2360         PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
2361         return (0);
2362
2363   bad:
2364         if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
2365         if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
2366         if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
2367         if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
2368         if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
2369         if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
2370         return (ENOBUFS);
2371 }
2372 #undef PKTOPT_EXTHDRCPY
2373
2374 struct ip6_pktopts *
2375 ip6_copypktopts(struct ip6_pktopts *src, int canwait)
2376 {
2377         int error;
2378         struct ip6_pktopts *dst;
2379
2380         dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
2381         if (dst == NULL)
2382                 return (NULL);
2383         ip6_initpktopts(dst);
2384
2385         if ((error = copypktopts(dst, src, canwait)) != 0) {
2386                 free(dst, M_IP6OPT);
2387                 return (NULL);
2388         }
2389
2390         return (dst);
2391 }
2392
2393 void
2394 ip6_freepcbopts(struct ip6_pktopts *pktopt)
2395 {
2396         if (pktopt == NULL)
2397                 return;
2398
2399         ip6_clearpktopts(pktopt, -1);
2400
2401         free(pktopt, M_IP6OPT);
2402 }
2403
2404 /*
2405  * Set the IP6 multicast options in response to user setsockopt().
2406  */
2407 static int
2408 ip6_setmoptions(int optname, struct ip6_moptions **im6op, struct mbuf *m)
2409 {
2410         int error = 0;
2411         u_int loop, ifindex;
2412         struct ipv6_mreq *mreq;
2413         struct ifnet *ifp;
2414         struct ip6_moptions *im6o = *im6op;
2415         struct route_in6 ro;
2416         struct in6_multi_mship *imm;
2417         struct thread *td = curthread;
2418
2419         if (im6o == NULL) {
2420                 /*
2421                  * No multicast option buffer attached to the pcb;
2422                  * allocate one and initialize to default values.
2423                  */
2424                 im6o = (struct ip6_moptions *)
2425                         malloc(sizeof(*im6o), M_IP6MOPTS, M_WAITOK);
2426
2427                 if (im6o == NULL)
2428                         return (ENOBUFS);
2429                 *im6op = im6o;
2430                 im6o->im6o_multicast_ifp = NULL;
2431                 im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2432                 im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
2433                 LIST_INIT(&im6o->im6o_memberships);
2434         }
2435
2436         switch (optname) {
2437
2438         case IPV6_MULTICAST_IF:
2439                 /*
2440                  * Select the interface for outgoing multicast packets.
2441                  */
2442                 if (m == NULL || m->m_len != sizeof(u_int)) {
2443                         error = EINVAL;
2444                         break;
2445                 }
2446                 bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
2447                 if (ifindex < 0 || if_index < ifindex) {
2448                         error = ENXIO;  /* XXX EINVAL? */
2449                         break;
2450                 }
2451                 ifp = ifnet_byindex(ifindex);
2452                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
2453                         error = EADDRNOTAVAIL;
2454                         break;
2455                 }
2456                 im6o->im6o_multicast_ifp = ifp;
2457                 break;
2458
2459         case IPV6_MULTICAST_HOPS:
2460             {
2461                 /*
2462                  * Set the IP6 hoplimit for outgoing multicast packets.
2463                  */
2464                 int optval;
2465                 if (m == NULL || m->m_len != sizeof(int)) {
2466                         error = EINVAL;
2467                         break;
2468                 }
2469                 bcopy(mtod(m, u_int *), &optval, sizeof(optval));
2470                 if (optval < -1 || optval >= 256)
2471                         error = EINVAL;
2472                 else if (optval == -1)
2473                         im6o->im6o_multicast_hlim = ip6_defmcasthlim;
2474                 else
2475                         im6o->im6o_multicast_hlim = optval;
2476                 break;
2477             }
2478
2479         case IPV6_MULTICAST_LOOP:
2480                 /*
2481                  * Set the loopback flag for outgoing multicast packets.
2482                  * Must be zero or one.
2483                  */
2484                 if (m == NULL || m->m_len != sizeof(u_int)) {
2485                         error = EINVAL;
2486                         break;
2487                 }
2488                 bcopy(mtod(m, u_int *), &loop, sizeof(loop));
2489                 if (loop > 1) {
2490                         error = EINVAL;
2491                         break;
2492                 }
2493                 im6o->im6o_multicast_loop = loop;
2494                 break;
2495
2496         case IPV6_JOIN_GROUP:
2497                 /*
2498                  * Add a multicast group membership.
2499                  * Group must be a valid IP6 multicast address.
2500                  */
2501                 if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2502                         error = EINVAL;
2503                         break;
2504                 }
2505                 mreq = mtod(m, struct ipv6_mreq *);
2506
2507                 if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
2508                         /*
2509                          * We use the unspecified address to specify to accept
2510                          * all multicast addresses. Only super user is allowed
2511                          * to do this.
2512                          */
2513                         if (suser(td)) {
2514                                 error = EACCES;
2515                                 break;
2516                         }
2517                 } else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
2518                         error = EINVAL;
2519                         break;
2520                 }
2521
2522                 /*
2523                  * If no interface was explicitly specified, choose an
2524                  * appropriate one according to the given multicast address.
2525                  */
2526                 if (mreq->ipv6mr_interface == 0) {
2527                         struct sockaddr_in6 *dst;
2528
2529                         /*
2530                          * Look up the routing table for the
2531                          * address, and choose the outgoing interface.
2532                          *   XXX: is it a good approach?
2533                          */
2534                         ro.ro_rt = NULL;
2535                         dst = (struct sockaddr_in6 *)&ro.ro_dst;
2536                         bzero(dst, sizeof(*dst));
2537                         dst->sin6_family = AF_INET6;
2538                         dst->sin6_len = sizeof(*dst);
2539                         dst->sin6_addr = mreq->ipv6mr_multiaddr;
2540                         rtalloc((struct route *)&ro);
2541                         if (ro.ro_rt == NULL) {
2542                                 error = EADDRNOTAVAIL;
2543                                 break;
2544                         }
2545                         ifp = ro.ro_rt->rt_ifp;
2546                         RTFREE(ro.ro_rt);
2547                 } else {
2548                         /*
2549                          * If the interface is specified, validate it.
2550                          */
2551                         if (mreq->ipv6mr_interface < 0 ||
2552                             if_index < mreq->ipv6mr_interface) {
2553                                 error = ENXIO;  /* XXX EINVAL? */
2554                                 break;
2555                         }
2556                         ifp = ifnet_byindex(mreq->ipv6mr_interface);
2557                         if (!ifp) {
2558                                 error = ENXIO;  /* XXX EINVAL? */
2559                                 break;
2560                         }
2561                 }
2562
2563                 /*
2564                  * See if we found an interface, and confirm that it
2565                  * supports multicast
2566                  */
2567                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
2568                         error = EADDRNOTAVAIL;
2569                         break;
2570                 }
2571
2572                 if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
2573                         error = EADDRNOTAVAIL; /* XXX: should not happen */
2574                         break;
2575                 }
2576
2577                 /*
2578                  * See if the membership already exists.
2579                  */
2580                 for (imm = im6o->im6o_memberships.lh_first;
2581                      imm != NULL; imm = imm->i6mm_chain.le_next)
2582                         if (imm->i6mm_maddr->in6m_ifp == ifp &&
2583                             IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2584                                                &mreq->ipv6mr_multiaddr))
2585                                 break;
2586                 if (imm != NULL) {
2587                         error = EADDRINUSE;
2588                         break;
2589                 }
2590                 /*
2591                  * Everything looks good; add a new record to the multicast
2592                  * address list for the given interface.
2593                  */
2594                 imm = in6_joingroup(ifp, &mreq->ipv6mr_multiaddr,  &error, 0);
2595                 if (imm == NULL)
2596                         break;
2597                 LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
2598                 break;
2599
2600         case IPV6_LEAVE_GROUP:
2601                 /*
2602                  * Drop a multicast group membership.
2603                  * Group must be a valid IP6 multicast address.
2604                  */
2605                 if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
2606                         error = EINVAL;
2607                         break;
2608                 }
2609                 mreq = mtod(m, struct ipv6_mreq *);
2610
2611                 /*
2612                  * If an interface address was specified, get a pointer
2613                  * to its ifnet structure.
2614                  */
2615                 if (mreq->ipv6mr_interface < 0 ||
2616                     if_index < mreq->ipv6mr_interface) {
2617                         error = ENXIO;  /* XXX EINVAL? */
2618                         break;
2619                 }
2620                 if (mreq->ipv6mr_interface == 0)
2621                         ifp = NULL;
2622                 else
2623                         ifp = ifnet_byindex(mreq->ipv6mr_interface);
2624
2625                 /* Fill in the scope zone ID */
2626                 if (ifp) {
2627                         if (in6_setscope(&mreq->ipv6mr_multiaddr, ifp, NULL)) {
2628                                 /* XXX: should not happen */
2629                                 error = EADDRNOTAVAIL;
2630                                 break;
2631                         }
2632                 } else if (mreq->ipv6mr_interface != 0) {
2633                         /*
2634                          * This case happens when the (positive) index is in
2635                          * the valid range, but the corresponding interface has
2636                          * been detached dynamically (XXX).
2637                          */
2638                         error = EADDRNOTAVAIL;
2639                         break;
2640                 } else {        /* ipv6mr_interface == 0 */
2641                         struct sockaddr_in6 sa6_mc;
2642
2643                         /*
2644                          * The API spec says as follows:
2645                          *  If the interface index is specified as 0, the
2646                          *  system may choose a multicast group membership to
2647                          *  drop by matching the multicast address only.
2648                          * On the other hand, we cannot disambiguate the scope
2649                          * zone unless an interface is provided.  Thus, we
2650                          * check if there's ambiguity with the default scope
2651                          * zone as the last resort.
2652                          */
2653                         bzero(&sa6_mc, sizeof(sa6_mc));
2654                         sa6_mc.sin6_family = AF_INET6;
2655                         sa6_mc.sin6_len = sizeof(sa6_mc);
2656                         sa6_mc.sin6_addr = mreq->ipv6mr_multiaddr;
2657                         error = sa6_embedscope(&sa6_mc, ip6_use_defzone);
2658                         if (error != 0)
2659                                 break;
2660                         mreq->ipv6mr_multiaddr = sa6_mc.sin6_addr;
2661                 }
2662
2663                 /*
2664                  * Find the membership in the membership list.
2665                  */
2666                 for (imm = im6o->im6o_memberships.lh_first;
2667                      imm != NULL; imm = imm->i6mm_chain.le_next) {
2668                         if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) &&
2669                             IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
2670                             &mreq->ipv6mr_multiaddr))
2671                                 break;
2672                 }
2673                 if (imm == NULL) {
2674                         /* Unable to resolve interface */
2675                         error = EADDRNOTAVAIL;
2676                         break;
2677                 }
2678                 /*
2679                  * Give up the multicast address record to which the
2680                  * membership points.
2681                  */
2682                 LIST_REMOVE(imm, i6mm_chain);
2683                 in6_delmulti(imm->i6mm_maddr);
2684                 free(imm, M_IP6MADDR);
2685                 break;
2686
2687         default:
2688                 error = EOPNOTSUPP;
2689                 break;
2690         }
2691
2692         /*
2693          * If all options have default values, no need to keep the mbuf.
2694          */
2695         if (im6o->im6o_multicast_ifp == NULL &&
2696             im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
2697             im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
2698             im6o->im6o_memberships.lh_first == NULL) {
2699                 free(*im6op, M_IP6MOPTS);
2700                 *im6op = NULL;
2701         }
2702
2703         return (error);
2704 }
2705
2706 /*
2707  * Return the IP6 multicast options in response to user getsockopt().
2708  */
2709 static int
2710 ip6_getmoptions(int optname, struct ip6_moptions *im6o, struct mbuf **mp)
2711 {
2712         u_int *hlim, *loop, *ifindex;
2713
2714         *mp = m_get(M_TRYWAIT, MT_HEADER);              /* XXX */
2715
2716         switch (optname) {
2717
2718         case IPV6_MULTICAST_IF:
2719                 ifindex = mtod(*mp, u_int *);
2720                 (*mp)->m_len = sizeof(u_int);
2721                 if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
2722                         *ifindex = 0;
2723                 else
2724                         *ifindex = im6o->im6o_multicast_ifp->if_index;
2725                 return (0);
2726
2727         case IPV6_MULTICAST_HOPS:
2728                 hlim = mtod(*mp, u_int *);
2729                 (*mp)->m_len = sizeof(u_int);
2730                 if (im6o == NULL)
2731                         *hlim = ip6_defmcasthlim;
2732                 else
2733                         *hlim = im6o->im6o_multicast_hlim;
2734                 return (0);
2735
2736         case IPV6_MULTICAST_LOOP:
2737                 loop = mtod(*mp, u_int *);
2738                 (*mp)->m_len = sizeof(u_int);
2739                 if (im6o == NULL)
2740                         *loop = ip6_defmcasthlim;
2741                 else
2742                         *loop = im6o->im6o_multicast_loop;
2743                 return (0);
2744
2745         default:
2746                 return (EOPNOTSUPP);
2747         }
2748 }
2749
2750 /*
2751  * Discard the IP6 multicast options.
2752  */
2753 void
2754 ip6_freemoptions(struct ip6_moptions *im6o)
2755 {
2756         struct in6_multi_mship *imm;
2757
2758         if (im6o == NULL)
2759                 return;
2760
2761         while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
2762                 LIST_REMOVE(imm, i6mm_chain);
2763                 if (imm->i6mm_maddr)
2764                         in6_delmulti(imm->i6mm_maddr);
2765                 free(imm, M_IP6MADDR);
2766         }
2767         free(im6o, M_IP6MOPTS);
2768 }
2769
2770 /*
2771  * Set IPv6 outgoing packet options based on advanced API.
2772  */
2773 int
2774 ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
2775     struct ip6_pktopts *stickyopt, int priv, int uproto)
2776 {
2777         struct cmsghdr *cm = 0;
2778
2779         if (control == NULL || opt == NULL)
2780                 return (EINVAL);
2781
2782         ip6_initpktopts(opt);
2783         if (stickyopt) {
2784                 int error;
2785
2786                 /*
2787                  * If stickyopt is provided, make a local copy of the options
2788                  * for this particular packet, then override them by ancillary
2789                  * objects.
2790                  * XXX: copypktopts() does not copy the cached route to a next
2791                  * hop (if any).  This is not very good in terms of efficiency,
2792                  * but we can allow this since this option should be rarely
2793                  * used.
2794                  */
2795                 if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
2796                         return (error);
2797         }
2798
2799         /*
2800          * XXX: Currently, we assume all the optional information is stored
2801          * in a single mbuf.
2802          */
2803         if (control->m_next)
2804                 return (EINVAL);
2805
2806         for (; control->m_len; control->m_data += CMSG_ALIGN(cm->cmsg_len),
2807             control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
2808                 int error;
2809
2810                 if (control->m_len < CMSG_LEN(0))
2811                         return (EINVAL);
2812
2813                 cm = mtod(control, struct cmsghdr *);
2814                 if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
2815                         return (EINVAL);
2816                 if (cm->cmsg_level != IPPROTO_IPV6)
2817                         continue;
2818
2819                 error = ip6_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
2820                     cm->cmsg_len - CMSG_LEN(0), opt, priv, 0, 1, uproto);
2821                 if (error)
2822                         return (error);
2823         }
2824
2825         return (0);
2826 }
2827
2828 /*
2829  * Set a particular packet option, as a sticky option or an ancillary data
2830  * item.  "len" can be 0 only when it's a sticky option.
2831  * We have 4 cases of combination of "sticky" and "cmsg":
2832  * "sticky=0, cmsg=0": impossible
2833  * "sticky=0, cmsg=1": RFC2292 or RFC3542 ancillary data
2834  * "sticky=1, cmsg=0": RFC3542 socket option
2835  * "sticky=1, cmsg=1": RFC2292 socket option
2836  */
2837 static int
2838 ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
2839     int priv, int sticky, int cmsg, int uproto)
2840 {
2841         int minmtupolicy, preftemp;
2842
2843         if (!sticky && !cmsg) {
2844 #ifdef DIAGNOSTIC
2845                 printf("ip6_setpktopt: impossible case\n");
2846 #endif
2847                 return (EINVAL);
2848         }
2849
2850         /*
2851          * IPV6_2292xxx is for backward compatibility to RFC2292, and should
2852          * not be specified in the context of RFC3542.  Conversely,
2853          * RFC3542 types should not be specified in the context of RFC2292.
2854          */
2855         if (!cmsg) {
2856                 switch (optname) {
2857                 case IPV6_2292PKTINFO:
2858                 case IPV6_2292HOPLIMIT:
2859                 case IPV6_2292NEXTHOP:
2860                 case IPV6_2292HOPOPTS:
2861                 case IPV6_2292DSTOPTS:
2862                 case IPV6_2292RTHDR:
2863                 case IPV6_2292PKTOPTIONS:
2864                         return (ENOPROTOOPT);
2865                 }
2866         }
2867         if (sticky && cmsg) {
2868                 switch (optname) {
2869                 case IPV6_PKTINFO:
2870                 case IPV6_HOPLIMIT:
2871                 case IPV6_NEXTHOP:
2872                 case IPV6_HOPOPTS:
2873                 case IPV6_DSTOPTS:
2874                 case IPV6_RTHDRDSTOPTS:
2875                 case IPV6_RTHDR:
2876                 case IPV6_USE_MIN_MTU:
2877                 case IPV6_DONTFRAG:
2878                 case IPV6_TCLASS:
2879                 case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
2880                         return (ENOPROTOOPT);
2881                 }
2882         }
2883
2884         switch (optname) {
2885         case IPV6_2292PKTINFO:
2886         case IPV6_PKTINFO:
2887         {
2888                 struct ifnet *ifp = NULL;
2889                 struct in6_pktinfo *pktinfo;
2890
2891                 if (len != sizeof(struct in6_pktinfo))
2892                         return (EINVAL);
2893
2894                 pktinfo = (struct in6_pktinfo *)buf;
2895
2896                 /*
2897                  * An application can clear any sticky IPV6_PKTINFO option by
2898                  * doing a "regular" setsockopt with ipi6_addr being
2899                  * in6addr_any and ipi6_ifindex being zero.
2900                  * [RFC 3542, Section 6]
2901                  */
2902                 if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
2903                     pktinfo->ipi6_ifindex == 0 &&
2904                     IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2905                         ip6_clearpktopts(opt, optname);
2906                         break;
2907                 }
2908
2909                 if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
2910                     sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
2911                         return (EINVAL);
2912                 }
2913
2914                 /* validate the interface index if specified. */
2915                 if (pktinfo->ipi6_ifindex > if_index ||
2916                     pktinfo->ipi6_ifindex < 0) {
2917                          return (ENXIO);
2918                 }
2919                 if (pktinfo->ipi6_ifindex) {
2920                         ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
2921                         if (ifp == NULL)
2922                                 return (ENXIO);
2923                 }
2924
2925                 /*
2926                  * We store the address anyway, and let in6_selectsrc()
2927                  * validate the specified address.  This is because ipi6_addr
2928                  * may not have enough information about its scope zone, and
2929                  * we may need additional information (such as outgoing
2930                  * interface or the scope zone of a destination address) to
2931                  * disambiguate the scope.
2932                  * XXX: the delay of the validation may confuse the
2933                  * application when it is used as a sticky option.
2934                  */
2935                 if (opt->ip6po_pktinfo == NULL) {
2936                         opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
2937                             M_IP6OPT, M_NOWAIT);
2938                         if (opt->ip6po_pktinfo == NULL)
2939                                 return (ENOBUFS);
2940                 }
2941                 bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
2942                 break;
2943         }
2944
2945         case IPV6_2292HOPLIMIT:
2946         case IPV6_HOPLIMIT:
2947         {
2948                 int *hlimp;
2949
2950                 /*
2951                  * RFC 3542 deprecated the usage of sticky IPV6_HOPLIMIT
2952                  * to simplify the ordering among hoplimit options.
2953                  */
2954                 if (optname == IPV6_HOPLIMIT && sticky)
2955                         return (ENOPROTOOPT);
2956
2957                 if (len != sizeof(int))
2958                         return (EINVAL);
2959                 hlimp = (int *)buf;
2960                 if (*hlimp < -1 || *hlimp > 255)
2961                         return (EINVAL);
2962
2963                 opt->ip6po_hlim = *hlimp;
2964                 break;
2965         }
2966
2967         case IPV6_TCLASS:
2968         {
2969                 int tclass;
2970
2971                 if (len != sizeof(int))
2972                         return (EINVAL);
2973                 tclass = *(int *)buf;
2974                 if (tclass < -1 || tclass > 255)
2975                         return (EINVAL);
2976
2977                 opt->ip6po_tclass = tclass;
2978                 break;
2979         }
2980
2981         case IPV6_2292NEXTHOP:
2982         case IPV6_NEXTHOP:
2983                 if (!priv)
2984                         return (EPERM);
2985
2986                 if (len == 0) { /* just remove the option */
2987                         ip6_clearpktopts(opt, IPV6_NEXTHOP);
2988                         break;
2989                 }
2990
2991                 /* check if cmsg_len is large enough for sa_len */
2992                 if (len < sizeof(struct sockaddr) || len < *buf)
2993                         return (EINVAL);
2994
2995                 switch (((struct sockaddr *)buf)->sa_family) {
2996                 case AF_INET6:
2997                 {
2998                         struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
2999                         int error;
3000
3001                         if (sa6->sin6_len != sizeof(struct sockaddr_in6))
3002                                 return (EINVAL);
3003
3004                         if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
3005                             IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
3006                                 return (EINVAL);
3007                         }
3008                         if ((error = sa6_embedscope(sa6, ip6_use_defzone))
3009                             != 0) {
3010                                 return (error);
3011                         }
3012                         break;
3013                 }
3014                 case AF_LINK:   /* should eventually be supported */
3015                 default:
3016                         return (EAFNOSUPPORT);
3017                 }
3018
3019                 /* turn off the previous option, then set the new option. */
3020                 ip6_clearpktopts(opt, IPV6_NEXTHOP);
3021                 opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
3022                 if (opt->ip6po_nexthop == NULL)
3023                         return (ENOBUFS);
3024                 bcopy(buf, opt->ip6po_nexthop, *buf);
3025                 break;
3026
3027         case IPV6_2292HOPOPTS:
3028         case IPV6_HOPOPTS:
3029         {
3030                 struct ip6_hbh *hbh;
3031                 int hbhlen;
3032
3033                 /*
3034                  * XXX: We don't allow a non-privileged user to set ANY HbH
3035                  * options, since per-option restriction has too much
3036                  * overhead.
3037                  */
3038                 if (!priv)
3039                         return (EPERM);
3040
3041                 if (len == 0) {
3042                         ip6_clearpktopts(opt, IPV6_HOPOPTS);
3043                         break;  /* just remove the option */
3044                 }
3045
3046                 /* message length validation */
3047                 if (len < sizeof(struct ip6_hbh))
3048                         return (EINVAL);
3049                 hbh = (struct ip6_hbh *)buf;
3050                 hbhlen = (hbh->ip6h_len + 1) << 3;
3051                 if (len != hbhlen)
3052                         return (EINVAL);
3053
3054                 /* turn off the previous option, then set the new option. */
3055                 ip6_clearpktopts(opt, IPV6_HOPOPTS);
3056                 opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
3057                 if (opt->ip6po_hbh == NULL)
3058                         return (ENOBUFS);
3059                 bcopy(hbh, opt->ip6po_hbh, hbhlen);
3060
3061                 break;
3062         }
3063
3064         case IPV6_2292DSTOPTS:
3065         case IPV6_DSTOPTS:
3066         case IPV6_RTHDRDSTOPTS:
3067         {
3068                 struct ip6_dest *dest, **newdest = NULL;
3069                 int destlen;
3070
3071                 if (!priv)      /* XXX: see the comment for IPV6_HOPOPTS */
3072                         return (EPERM);
3073
3074                 if (len == 0) {
3075                         ip6_clearpktopts(opt, optname);
3076                         break;  /* just remove the option */
3077                 }
3078
3079                 /* message length validation */
3080                 if (len < sizeof(struct ip6_dest))
3081                         return (EINVAL);
3082                 dest = (struct ip6_dest *)buf;
3083                 destlen = (dest->ip6d_len + 1) << 3;
3084                 if (len != destlen)
3085                         return (EINVAL);
3086
3087                 /*
3088                  * Determine the position that the destination options header
3089                  * should be inserted; before or after the routing header.
3090                  */
3091                 switch (optname) {
3092                 case IPV6_2292DSTOPTS:
3093                         /*
3094                          * The old advacned API is ambiguous on this point.
3095                          * Our approach is to determine the position based
3096                          * according to the existence of a routing header.
3097                          * Note, however, that this depends on the order of the
3098                          * extension headers in the ancillary data; the 1st
3099                          * part of the destination options header must appear
3100                          * before the routing header in the ancillary data,
3101                          * too.
3102                          * RFC3542 solved the ambiguity by introducing
3103                          * separate ancillary data or option types.
3104                          */
3105                         if (opt->ip6po_rthdr == NULL)
3106                                 newdest = &opt->ip6po_dest1;
3107                         else
3108                                 newdest = &opt->ip6po_dest2;
3109                         break;
3110                 case IPV6_RTHDRDSTOPTS:
3111                         newdest = &opt->ip6po_dest1;
3112                         break;
3113                 case IPV6_DSTOPTS:
3114                         newdest = &opt->ip6po_dest2;
3115                         break;
3116                 }
3117
3118                 /* turn off the previous option, then set the new option. */
3119                 ip6_clearpktopts(opt, optname);
3120                 *newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
3121                 if (*newdest == NULL)
3122                         return (ENOBUFS);
3123                 bcopy(dest, *newdest, destlen);
3124
3125                 break;
3126         }
3127
3128         case IPV6_2292RTHDR:
3129         case IPV6_RTHDR:
3130         {
3131                 struct ip6_rthdr *rth;
3132                 int rthlen;
3133
3134                 if (len == 0) {
3135                         ip6_clearpktopts(opt, IPV6_RTHDR);
3136                         break;  /* just remove the option */
3137                 }
3138
3139                 /* message length validation */
3140                 if (len < sizeof(struct ip6_rthdr))
3141                         return (EINVAL);
3142                 rth = (struct ip6_rthdr *)buf;
3143                 rthlen = (rth->ip6r_len + 1) << 3;
3144                 if (len != rthlen)
3145                         return (EINVAL);
3146
3147                 switch (rth->ip6r_type) {
3148                 case IPV6_RTHDR_TYPE_0:
3149                         if (rth->ip6r_len == 0) /* must contain one addr */
3150                                 return (EINVAL);
3151                         if (rth->ip6r_len % 2) /* length must be even */
3152                                 return (EINVAL);
3153                         if (rth->ip6r_len / 2 != rth->ip6r_segleft)
3154                                 return (EINVAL);
3155                         break;
3156                 default:
3157                         return (EINVAL);        /* not supported */
3158                 }
3159
3160                 /* turn off the previous option */
3161                 ip6_clearpktopts(opt, IPV6_RTHDR);
3162                 opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
3163                 if (opt->ip6po_rthdr == NULL)
3164                         return (ENOBUFS);
3165                 bcopy(rth, opt->ip6po_rthdr, rthlen);
3166
3167                 break;
3168         }
3169
3170         case IPV6_USE_MIN_MTU:
3171                 if (len != sizeof(int))
3172                         return (EINVAL);
3173                 minmtupolicy = *(int *)buf;
3174                 if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
3175                     minmtupolicy != IP6PO_MINMTU_DISABLE &&
3176                     minmtupolicy != IP6PO_MINMTU_ALL) {
3177                         return (EINVAL);
3178                 }
3179                 opt->ip6po_minmtu = minmtupolicy;
3180                 break;
3181
3182         case IPV6_DONTFRAG:
3183                 if (len != sizeof(int))
3184                         return (EINVAL);
3185
3186                 if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
3187                         /*
3188                          * we ignore this option for TCP sockets.
3189                          * (RFC3542 leaves this case unspecified.)
3190                          */
3191                         opt->ip6po_flags &= ~IP6PO_DONTFRAG;
3192                 } else
3193                         opt->ip6po_flags |= IP6PO_DONTFRAG;
3194                 break;
3195
3196         case IPV6_PREFER_TEMPADDR:
3197                 if (len != sizeof(int))
3198                         return (EINVAL);
3199                 preftemp = *(int *)buf;
3200                 if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
3201                     preftemp != IP6PO_TEMPADDR_NOTPREFER &&
3202                     preftemp != IP6PO_TEMPADDR_PREFER) {
3203                         return (EINVAL);
3204                 }
3205                 opt->ip6po_prefer_tempaddr = preftemp;
3206                 break;
3207
3208         default:
3209                 return (ENOPROTOOPT);
3210         } /* end of switch */
3211
3212         return (0);
3213 }
3214
3215 /*
3216  * Routine called from ip6_output() to loop back a copy of an IP6 multicast
3217  * packet to the input queue of a specified interface.  Note that this
3218  * calls the output routine of the loopback "driver", but with an interface
3219  * pointer that might NOT be &loif -- easier than replicating that code here.
3220  */
3221 void
3222 ip6_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in6 *dst)
3223 {
3224         struct mbuf *copym;
3225         struct ip6_hdr *ip6;
3226
3227         copym = m_copy(m, 0, M_COPYALL);
3228         if (copym == NULL)
3229                 return;
3230
3231         /*
3232          * Make sure to deep-copy IPv6 header portion in case the data
3233          * is in an mbuf cluster, so that we can safely override the IPv6
3234          * header portion later.
3235          */
3236         if ((copym->m_flags & M_EXT) != 0 ||
3237             copym->m_len < sizeof(struct ip6_hdr)) {
3238                 copym = m_pullup(copym, sizeof(struct ip6_hdr));
3239                 if (copym == NULL)
3240                         return;
3241         }
3242
3243 #ifdef DIAGNOSTIC
3244         if (copym->m_len < sizeof(*ip6)) {
3245                 m_freem(copym);
3246                 return;
3247         }
3248 #endif
3249
3250         ip6 = mtod(copym, struct ip6_hdr *);
3251         /*
3252          * clear embedded scope identifiers if necessary.
3253          * in6_clearscope will touch the addresses only when necessary.
3254          */
3255         in6_clearscope(&ip6->ip6_src);
3256         in6_clearscope(&ip6->ip6_dst);
3257
3258         (void)if_simloop(ifp, copym, dst->sin6_family, 0);
3259 }
3260
3261 /*
3262  * Chop IPv6 header off from the payload.
3263  */
3264 static int
3265 ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
3266 {
3267         struct mbuf *mh;
3268         struct ip6_hdr *ip6;
3269
3270         ip6 = mtod(m, struct ip6_hdr *);
3271         if (m->m_len > sizeof(*ip6)) {
3272                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
3273                 if (mh == 0) {
3274                         m_freem(m);
3275                         return ENOBUFS;
3276                 }
3277                 M_MOVE_PKTHDR(mh, m);
3278                 MH_ALIGN(mh, sizeof(*ip6));
3279                 m->m_len -= sizeof(*ip6);
3280                 m->m_data += sizeof(*ip6);
3281                 mh->m_next = m;
3282                 m = mh;
3283                 m->m_len = sizeof(*ip6);
3284                 bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
3285         }
3286         exthdrs->ip6e_ip6 = m;
3287         return 0;
3288 }
3289
3290 /*
3291  * Compute IPv6 extension header length.
3292  */
3293 int
3294 ip6_optlen(struct in6pcb *in6p)
3295 {
3296         int len;
3297
3298         if (!in6p->in6p_outputopts)
3299                 return 0;
3300
3301         len = 0;
3302 #define elen(x) \
3303     (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)
3304
3305         len += elen(in6p->in6p_outputopts->ip6po_hbh);
3306         if (in6p->in6p_outputopts->ip6po_rthdr)
3307                 /* dest1 is valid with rthdr only */
3308                 len += elen(in6p->in6p_outputopts->ip6po_dest1);
3309         len += elen(in6p->in6p_outputopts->ip6po_rthdr);
3310         len += elen(in6p->in6p_outputopts->ip6po_dest2);
3311         return len;
3312 #undef elen
3313 }